Injury to Perineal Branch of Pudendal Nerve in Women: Outcome from Resection of the Perineal Branches

J reconstr Microsurg
DOI: 10.1055/s-0037-1599130

Background This study describes outcomes from a new surgical approach to treat "anterior" pudendal nerve symptoms in women by resecting the perineal branches of the pudendal nerve (PBPN). Methods Sixteen consecutive female patients with pain in the labia, vestibule, and perineum, who had positive diagnostic pudendal nerve blocks from 2012 through 2015, are included. The PBPN were resected and implanted into the obturator internus muscle through a paralabial incision. The mean age at surgery was 49.5 years (standard deviation [SD] = 11.6 years) and the mean body mass index was 25.7 (SD = 5.8). Out of the 16 patients, mechanisms of injury were episiotomy in 5 (31%), athletic injury in 4 (25%), vulvar vestibulectomy in 5 (31%), and falls in 2 (13%). Of these 16 patients, 4 (25%) experienced urethral symptoms. Outcome measures included Female Sexual Function Index (FSFI), Vulvar Pain Functional Questionnaire (VQ), and Numeric Pain Rating Scale (NPRS). Results Fourteen patients reported their condition pre- and postoperatively. Mean postoperative follow-up was 15 months. The overall FSFI, and arousal, lubrication, orgasm, satisfaction, and pain domains significantly improved (p < 0.05). The VQ also significantly improved (p < 0.001) in 13 (93%) of 14 patients. The NPRS score decreased on average from 8 to 3 (p < 0.0001). All four patients with urethral symptoms were relieved of these symptoms. Conclusion Resection of the PBPN with implantation of the nerve into the obturator internus muscle significantly reduced pain and improved sexual function in women who sustained injury to the PBPN.
[...]

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End-to-End versus End-to-Side Microvascular Anastomosis: A Meta-analysis of Free Flap Outcomes

J reconstr Microsurg
DOI: 10.1055/s-0037-1599099

Background Optimal outcomes in microsurgery have been attributed to a range of factors, with performing of end-to-end (ETE) versus end-to-side (ETS) influencing anastomotic complications and flap outcomes. Methods A systematic review of the literature and meta-analysis was undertaken to evaluate the relative risks of anastomotic complications with ETE versus ETS approaches, for arterial and venous anastomoses looking at risk ratios (RRs) for thrombosis and overall flap failure. Results RRs of thrombosis and flap failure in ETS versus ETE venous anastomosis groups were 1.30 (95% confidence interval [CI]: 0.53–3.21) and 1.50 (95% CI: 0.85–2.67), respectively. The RRs of thrombosis and flap failure in ETS versus ETE arterial anastomosis groups were 1.04 (95% CI: 0.32–3.35) and 1.04 (95% CI: 0.72–1.48), respectively. Conclusion Differences in rates of thrombosis and flap failure between ETE and ETS venous and arterial anastomoses are marginal and nonsignificant. As such, the type of anastomotic technique is best decided on a case-by-case basis, dependent on anatomical, surgical, and patient factors.
[...]

Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

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Surgeon-Based 3D Printing for Microvascular Bone Flaps

J reconstr Microsurg
DOI: 10.1055/s-0037-1600133

Background Three-dimensional (3D) printing has developed as a revolutionary technology with the capacity to design accurate physical models in preoperative planning. We present our experience in surgeon-based design of 3D models, using home 3D software and printing technology for use as an adjunct in vascularized bone transfer. Methods Home 3D printing techniques were used in the design and execution of vascularized bone flap transfers to the upper extremity. Open source imaging software was used to convert preoperative computed tomography scans and create 3D models. These were printed in the surgeon's office as 3D models for the planned reconstruction. Vascularized bone flaps were designed intraoperatively based on the 3D printed models. Results Three-dimensional models were created for intraoperative use in vascularized bone flaps, including (1) medial femoral trochlea (MFT) flap for scaphoid avascular necrosis and nonunion, (2) MFT flap for lunate avascular necrosis and nonunion, (3) medial femoral condyle (MFC) flap for wrist arthrodesis, and (4) free fibula osteocutaneous flap for distal radius septic nonunion. Templates based on the 3D models allowed for the precise and rapid contouring of well-vascularized bone flaps in situ, prior to ligating the donor pedicle. Conclusions Surgeon-based 3D printing is a feasible, innovative technology that allows for the precise and rapid contouring of models that can be created in various configurations for pre- and intraoperative planning. The technology is easy to use, convenient, and highly economical as compared with traditional send-out manufacturing. Surgeon-based 3D printing is a useful adjunct in vascularized bone transfer. Level of Evidence Level IV.
[...]

Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA

Article in Thieme eJournals:
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Radiocaesium contamination and dose rate estimation of terrestrial and freshwater wildlife in the exclusion zone of the Fukushima Dai-ichi Nuclear Power Plant accident

Publication date: May 2017
Source:Journal of Environmental Radioactivity, Volume 171
Author(s): Shoichi Fuma, Sadao Ihara, Hiroyuki Takahashi, Osamu Inaba, Youji Sato, Yoshihisa Kubota, Yoshito Watanabe, Isao Kawaguchi, Tatsuo Aono, Haruhi Soeda, Satoshi Yoshida
To characterise the radioactive contamination of terrestrial and freshwater wildlife caused by the Fukushima Dai-ichi Nuclear Power Plant accident, biological samples, namely, fungi, mosses, plants, amphibians, reptiles, insects, molluscs, and earthworms, were collected mainly from the forests of the exclusion zone in the Fukushima Prefecture from 2011 to 2012. Caesium-134 and ¹³⁷Cs were detected by gamma spectrometry in almost all the samples. Fungi, ferns, and mosses accumulated high amounts of radiocaesium, as they did in Chernobyl, with ¹³⁴Cs + ¹³⁷Cs activity concentrations of 10⁴–10⁶ Bq kg⁻¹ fresh mass (FM). Earthworms, amphibians, and the soft tissue of the garden snail Acusta despecta sieboldiana, also had levels as high as 10⁴–10⁵ Bq kg⁻¹ FM of ¹³⁴Cs + ¹³⁷Cs. Most of the estimated total (internal + external) dose rates to herbaceous plants, amphibians, insects, and earthworms were below the corresponding derived consideration reference levels (DCRLs) recommended by the ICRP. This suggests that, in most cases, there was little chance of deleterious effects of ionising radiation on these organisms in the exclusion zone for the first year after the accident, though the dose rates were underestimated mainly due to the lack of consideration of short-lived radionuclides.



http://ift.tt/2lJm6pb

Meeting report: Metastasis Research Society–Chinese Tumor Metastasis Society joint conference on metastasis

Abstract

During September 16th–20th 2016, metastasis experts from around the world convened for the 16th Biennial Congress of the Metastasis Research Society and 12th National Congress of the Chinese Tumor Metastasis Society in Chengdu, China to share most current data covering basic, translational, and clinical metastasis research. Presentations of the more than 40 invited speakers of the main congress and presentations from the associated Young Investigator Satellite Meeting are summarized in this report by session topic. The congress program also included three concurrent short talk sessions, an advocacy forum with Chinese and American metastatic patient advocates, a 'Meet the Professors Roundtable' session for young investigators, and a 'Meet the Editors' session with editors from Cancer Cell and Nature Cell Biology. The goal of integrating expertise and exchanging the latest findings, ideas, and practices in cancer metastasis research was achieved magnificently, thanks to the excellent contributions of many leaders in the field.

http://ift.tt/2mnEsAi

A reflection and a look forward with Dr. Sue Eccles, retired Editor-in-Chief of Clinical and Experimental Metastasis

Abstract

After a lifetime's work devoted to metastasis research, Dr. Sue Eccles recently retired. She was a founding member the Metastasis Research Society in 1984, and has served as Editor-In-Chief of Clinical and Experimental Metastasis from its inception until her retirement, an amazing 32 years of service. Dr. Kate Bakaitis recently talked with Dr. Eccles about her experiences, memories and advice for young investigators.

http://ift.tt/2mZqvFE

Cabergoline for hyperprolactinemia: getting to the heart of it

http://ift.tt/2lqzSlp

Follicle stimulating hormone, its novel association with sex hormone binding globulin in men and postmenopausal women

Abstract

Purpose

Follicle stimulating hormone plays direct roles in a variety of nongonadal tissues and sex hormone binding globulin is becoming the convergence of the crosstalk among metabolic diseases. However, no studies have explored the association between follicle stimulating hormone and sex hormone binding globulin. We aimed to study this association among men and women.

Methods

SPECT-China is a population-based study conducted since 2014. This study included 4206 men and 2842 postmenopausal women. Collected serum was assayed for gonadotropins, sex hormone binding globulin, sex hormones etc. Regression analyses were performed to assess the relationship between sex hormone binding globulin and follicle stimulating hormone and other variables including metabolic factors, thyroid function and sex hormones. Treatment with follicle stimulating hormone at different concentrations of 0, 5, 50 and 100 IU/L for 24 h was performed in HepG2 cells.

Results

In Spearman correlation, sex hormone binding globulin was significantly correlated with FSH, triglycerides, thyroxins, body mass index and blood pressure in men and postmenopausal women (all P < 0.05). In regression analyses, follicle stimulating hormone was a significant predictor of sex hormone binding globulin in men and postmenopausal women (P < 0.05), independent of above variables. Follicle stimulating hormone induced sex hormone binding globulin expression in a dose-dependent fashion in HepG2 cells.

Conclusion

Serum follicle stimulating hormone levels were positively associated with circulating sex hormone binding globulin levels in men and postmenopausal women. This association is independent of age, insulin resistance, hepatic function, lipid profile, thyroid function, adiposity, blood pressure, and endogenous sex hormones.

http://ift.tt/2mR0YPR

Biochemical assessment of disease control in acromegaly: reappraisal of the glucose suppression test in somatostatin analogue (SA) treated patients

Abstract

Background

It is recommended not to measure growth hormone during oral glucose suppression (oral glucose tolerance test) during somatostatin analog treatment in acromegaly. However, we have observed that failure to suppress growth hormone in response to oral glucose tolerance test during somatostatin analog unmasks insufficient disease control and hypothesize that somatostatin analog also induces insufficient growth hormone suppression to mixed meals.

Methods

We therefore compared serum growth hormone levels during two mixed meals in patients with controlled insulin-like growth factor-I levels after either surgery alone (n = 9) or somatostatin analog treatment (n = 9). The patients were unbiasedly matched for gender and insulin-like growth factor-I and studied twice in the following order: (1) during a 6 h growth hormone day curve including two mixed meals and (2) during a 3 h growth hormone profile including 60 min fasting followed by a 2-h oral glucose tolerance test.

Results

During the day curve growth hormone levels were elevated in the somatostatin analog group (P = 0.008) and growth hormone levels 1 h after each meal declined significantly only in the surgery group (P = 0.02). During the oral glucose tolerance test the two groups had similar growth hormone levels prior to the glucose load (P = 0.6), whereas a significant 66% suppression was observed after glucose only in the surgery group (P = 0.001).

Conclusions

(1) Patients controlled by somatostatin analog fail to suppress growth hormone in response to both mixed meals and oral glucose tolerance test (2) This phenomenon is likely to result in elevated serum growth hormone levels during everyday life in somatostatin analog-treated patients, (3) We postulate that measuring growth hormone levels during oral glucose tolerance test is useful to unmask potential somatostatin analog under-treatment in the presence of 'safe' insulin-like growth factor-I levels.

http://ift.tt/2lqgqWd

Cabergoline for hyperprolactinemia: getting to the heart of it

http://ift.tt/2lqzSlp

Follicle stimulating hormone, its novel association with sex hormone binding globulin in men and postmenopausal women

Abstract

Purpose

Follicle stimulating hormone plays direct roles in a variety of nongonadal tissues and sex hormone binding globulin is becoming the convergence of the crosstalk among metabolic diseases. However, no studies have explored the association between follicle stimulating hormone and sex hormone binding globulin. We aimed to study this association among men and women.

Methods

SPECT-China is a population-based study conducted since 2014. This study included 4206 men and 2842 postmenopausal women. Collected serum was assayed for gonadotropins, sex hormone binding globulin, sex hormones etc. Regression analyses were performed to assess the relationship between sex hormone binding globulin and follicle stimulating hormone and other variables including metabolic factors, thyroid function and sex hormones. Treatment with follicle stimulating hormone at different concentrations of 0, 5, 50 and 100 IU/L for 24 h was performed in HepG2 cells.

Results

In Spearman correlation, sex hormone binding globulin was significantly correlated with FSH, triglycerides, thyroxins, body mass index and blood pressure in men and postmenopausal women (all P < 0.05). In regression analyses, follicle stimulating hormone was a significant predictor of sex hormone binding globulin in men and postmenopausal women (P < 0.05), independent of above variables. Follicle stimulating hormone induced sex hormone binding globulin expression in a dose-dependent fashion in HepG2 cells.

Conclusion

Serum follicle stimulating hormone levels were positively associated with circulating sex hormone binding globulin levels in men and postmenopausal women. This association is independent of age, insulin resistance, hepatic function, lipid profile, thyroid function, adiposity, blood pressure, and endogenous sex hormones.

http://ift.tt/2mR0YPR

Biochemical assessment of disease control in acromegaly: reappraisal of the glucose suppression test in somatostatin analogue (SA) treated patients

Abstract

Background

It is recommended not to measure growth hormone during oral glucose suppression (oral glucose tolerance test) during somatostatin analog treatment in acromegaly. However, we have observed that failure to suppress growth hormone in response to oral glucose tolerance test during somatostatin analog unmasks insufficient disease control and hypothesize that somatostatin analog also induces insufficient growth hormone suppression to mixed meals.

Methods

We therefore compared serum growth hormone levels during two mixed meals in patients with controlled insulin-like growth factor-I levels after either surgery alone (n = 9) or somatostatin analog treatment (n = 9). The patients were unbiasedly matched for gender and insulin-like growth factor-I and studied twice in the following order: (1) during a 6 h growth hormone day curve including two mixed meals and (2) during a 3 h growth hormone profile including 60 min fasting followed by a 2-h oral glucose tolerance test.

Results

During the day curve growth hormone levels were elevated in the somatostatin analog group (P = 0.008) and growth hormone levels 1 h after each meal declined significantly only in the surgery group (P = 0.02). During the oral glucose tolerance test the two groups had similar growth hormone levels prior to the glucose load (P = 0.6), whereas a significant 66% suppression was observed after glucose only in the surgery group (P = 0.001).

Conclusions

(1) Patients controlled by somatostatin analog fail to suppress growth hormone in response to both mixed meals and oral glucose tolerance test (2) This phenomenon is likely to result in elevated serum growth hormone levels during everyday life in somatostatin analog-treated patients, (3) We postulate that measuring growth hormone levels during oral glucose tolerance test is useful to unmask potential somatostatin analog under-treatment in the presence of 'safe' insulin-like growth factor-I levels.

http://ift.tt/2lqgqWd

CO 2 laser for the treatment of diabetic foot ulcers with exposed bone. A consecutive series of type 2 diabetic patients

Abstract

Aim

The treatment of foot ulcers with exposed bone is challenging, because of the risk of infection and of difficulties in the development of granulation tissue. A CO₂ laser beam could be used to produce discontinuities in periosteum, allowing the exposure of blood containing multipotent stem cells, capable of initiating the healing process. The local application of platelet-rich plasma (PRP) has been proposed as a therapeutic tool for accelerating healing in foot ulcers, including those in patients with diabetes. Aim of the present pilot, proof-of-concept study is the assessment of the therapeutic potential of CO₂ laser treatment, either alone or combined with PRP, in the treatment of diabetic foot ulcers with exposed bone.

Methods

We performed a pilot, uncontrolled 3-month observation study on a consecutive series of 9 type two diabetic patients and foot ulcers with exposed bone. A CO₂-laser was used for producing nine discontinuities on periosteum for each cm², by directing the focused laser beam on the bone until bleeding. The procedure was repeated up to 6 times, at a distance of 1 week and ulcers assessed weekly until the end of the study (3 months). In the last 5 of the 14 patients, the treatment described above was associated with PRP.

Results

Of the nine patients treated, four healed, and one more patient developed granulation tissue covering entirely bone surface. Out of the four patients who did not heal, one underwent minor amputation. Among the five patients treated with a combination of CO₂ laser and PRP, two healed within 3 months, and two more patients developed granulation tissue covering entirely bone surface; the fifth patient did not show any improvement and underwent amputation.

Conclusions

The present pilot experience represents a novelty in this field showing a possible use of CO₂-laser in the treatment of diabetic foot ulcers.

http://ift.tt/2mQSSqa

Immunotherapy for type 1 diabetes

Abstract

Introduction

Although many approaches have been tested to overcome the insulin dependence caused by the pancreatic β-cells destruction observed in individuals affected by type 1 diabetes (T1D), medical research has largely failed to halt the onset or to reverse T1D.

Methods

In this work, the state of the art of immunotherapy will be examined, and the most important achievement in the field will be critically discussed. Particularly, we will focus on the clinical aspect, thus avoiding the tedious preclinical work done in NOD mice, which has been so poorly translated to the bedside.

Conclusions

Stem cell therapies achieved thus this far the most promising results, while immune ablation and standard immunosuppressants did not maintain the premises of preclinical results. The next step will be to generate a feasible and safe clinical approach in order to cure the thousands of patients affected by T1D.

http://ift.tt/2lqmm1f

Pharyngitis in the Wake of an Invasive Dental Procedure

Publication date: Available online 3 March 2017
Source:The Journal of Emergency Medicine
Author(s): Erica Simon, Brit Long, Craig Pedersen




http://ift.tt/2mn1HdS

The Role of Early Focused Cardiac Ultrasound in a Not-So-Typical Presentation of Takotsubo Cardiomyopathy: A Case Report

Publication date: Available online 3 March 2017
Source:The Journal of Emergency Medicine
Author(s): Jithin G. Varghese, Qurat-ul-ain Jelani, Stuart Zarich, Brooks Walsh
BackgroundFocused cardiac ultrasound (FoCUS) can be extremely helpful in identifying unexpected diagnoses that can significantly alter treatment options. The diagnosis of Takotsubo cardiomyopathy (TCM) may be difficult to identify.Case ReportWe describe a 47-year-old woman who presented to the emergency department (ED) with atypical features of TCM. Her clinical features included being a premenopausal woman with mild chest pain with a lack of identifiable emotional or physical stressors or significant electrocardiographic changes. Initial findings on FoCUS were consistent with TCM, with these findings replicated on repeat bedside echo performed in the ED by the cardiology fellow. A subsequent comprehensive echo showed marked improvement of the TCM pattern within 24 hours.Why Should an Emergency Physician Be Aware of This?TCM may present in younger women or men, without obvious preceding physical or emotional stressors and with nonspecific ECG findings. FoCUS performed in the ED may suggest a diagnosis of TCM in patients with chest pain or dyspnea of uncertain etiology. The performance of FoCUS, as highlighted by this case report, can lead to timely intervention and follow-up of a variety of cardiac conditions.



http://ift.tt/2lIblU7

Spontaneous Hemothorax, A Rare Face of Vertebral Osteochondroma

Publication date: Available online 3 March 2017
Source:The Journal of Emergency Medicine
Author(s): Sarah Sainte, Herbert Decaluwé, Peter Vanbrabant
BackgroundOsteochondroma is the most common benign tumor of the bone. It is usually asymptomatic, but complications may result from mechanical injury to adjacent anatomic structures, such as the diaphragm and lung, when located intrathoracically.Case ReportWe report the unusual occurrence of a large hemothorax and lacerated right diaphragm in a 41-year-old woman caused by vertebral osteochondroma affecting the eleventh thoracic vertebra. Thoracoscopic exploration with resection of the osteochondroma and repair of the diaphragm was performed.Why Should an Emergency Physician Be Aware of This?Spontaneous hemothorax is a potential life-threatening condition when the initial diagnosis is postponed and hemodynamic instability and hypovolemic shock occurs. Osteochondroma as a cause of spontaneous hemothorax is uncommon but may require urgent surgical intervention with video-assisted thoracoscopic surgery of thoracotomy to control the hemorrhage and prevent recurrence.



http://ift.tt/2mmYkDD

Effects of Student-Performed Point-of-Care Ultrasound on Physician Diagnosis and Management of Patients in the Emergency Department

Publication date: Available online 3 March 2017
Source:The Journal of Emergency Medicine
Author(s): Daniel S. Udrea, Andrew Sumnicht, Deanna Lo, Logan Villarreal, Stephanie Gondra, Richard Chyan, Audra Wisham, Vi Am Dinh
BackgroundDespite the increasing integration of ultrasound training into medical education, there is an inadequate body of research demonstrating the benefits and practicality of medical student–performed point-of-care ultrasound (SP-POCUS) in the clinical setting.ObjectivesThe primary purpose of this study was to evaluate the effects that SP-POCUS can have on physician diagnosis and management of patients in the emergency department, with a secondary purpose of evaluating the diagnostic accuracy of SP-POCUS.MethodsSP-POCUS examinations were performed in the emergency department by medical students who completed year one of a 4-year medical school curriculum with integrated ultrasound training. Scans were evaluated by an emergency physician who then completed a survey to record any changes in diagnosis and management.ResultsA total of 641 scans were performed on the 482 patients enrolled in this study. SP-POCUS resulted in a change in management in 17.3% of scans performed. For 12.4% of scans, SP-POCUS discovered a new diagnosis. SP-POCUS reduced time to disposition 33.5% of the time. Because of SP-POCUS, physicians avoided ordering an additional imaging study for 53.0% of the scans performed. There was 94.7% physician agreement with SP-POCUS diagnosis.ConclusionsThis study showed that SP-POCUS is feasible and may potentially have a meaningful impact on physician diagnosis and management of patients in the emergency department. In addition, the implementation of SP-POCUS could serve as an ideal method of developing ultrasound skills in medical school while positively impacting patient care.



http://ift.tt/2lI1kX9

Impact of low-level laser therapy on hyposalivation, salivary pH, and quality of life in head and neck cancer patients post-radiotherapy

Abstract

Late effects of radiotherapy for head and neck cancer treatment have been increasingly investigated due to its impact on patients' quality of life. The purpose of this study was to evaluate the effect of low-level laser therapy on hyposalivation, low salivary pH, and quality of life in head and neck cancer patients post-radiotherapy. Twenty-nine patients with radiation-induced xerostomia received laser sessions twice a week, during 3 months (24 sessions). For this, a continuous wave Indium-Gallium-Aluminium-Phosphorus diode laser device was used punctually on the major salivary glands (808 nm, 0.75 W/cm², 30 mW, illuminated area 0.04 cm², 7.5 J/cm², 10 s, 0.3 J). Six extraoral points were illuminated on each parotid gland and three on each submandibular gland, as well as two intraoral points on each sublingual gland. Stimulated and unstimulated salivary flow rate, pH (two scales with different gradations), and quality of life (University Of Washington Quality of Life Questionnaire for Patients with Head and Neck Cancer) were assessed at baseline and at the end of the treatment. There were significant increases in both mean salivary flow rates (unstimulated: p = 0.0012; stimulated: p < 0.0001), mean pH values (p = 0.0002 and p = 0.0004), and mean score from the quality of life questionnaire (p < 0.0001). Low-level laser therapy seems to be effective to mitigate salivary hypofunction and increase salivary pH of patients submitted to radiotherapy for head and neck cancer, thereby leading to an improvement in quality of life.

http://ift.tt/2m5QvBA

Response Inhibition and Internet Gaming Disorder: A Meta-analysis

Publication date: August 2017
Source:Addictive Behaviors, Volume 71
Author(s): Evangelia Argyriou, Christopher B. Davison, Tayla T.C. Lee
Previous research has demonstrated that Internet Gaming Disorder (IGD) has multiple negative effects in psychological functioning and health. This makes the identification of its underpinnings, such as response inhibition, essential for the development of relevant interventions that target these core features of the disorder resulting in more effective treatment. Several empirical studies have evaluated the relationship between response inhibition deficits and IGD using neurocognitive tasks, but provided mixed results. In this study, we conducted a meta-analysis of studies using three neurocognitive tasks, the Go/No Go, the Stroop, and the Stop-Signal tasks, to integrate existing research and estimate the magnitude of this relationship. We found a medium overall effect size (d=0.56, 95% CI [0.32, 0.80]) indicating that compared with healthy individuals, individuals with IGD are more likely to exhibit impaired response inhibition. This finding is in alignment with literature on inhibition and addictive and impulsive behaviors, as well as with neuroimaging research. Theoretical implications regarding the conceptualization of IGD as a clinical disorder, shared commonalities with externalizing psychopathology, and clinical implications for treatment are discussed.



http://ift.tt/2lHVc18

Development and validation of a model to predict blood alcohol concentrations: Updating the NHTSA equation

Publication date: August 2017
Source:Addictive Behaviors, Volume 71
Author(s): Yiqi Zhang, Changxu Wu, Jingyan Wan
ObjectsTo date, multiple models have been developed to estimate blood or breath alcohol concentration (BAC/BrAC). Several factors have been identified that affect the discrepancy between BACs/BrACs and retrospective estimation (eBAC) with existing equations. To the best of our knowledge, a model to quantify the effects of factors on the discrepancy between BAC/BrAC and eBAC is still nonexistent. The goal of this work was to develop a model to provide a more accurate retrospective estimation of breath alcohol concentration (eBAC).MethodA laboratory study with alcohol consumption and a driving task was conducted with 30 participants (17 male and 13 female) to explore the factors that may contribute to the discrepancy between BrAC and eBAC obtained with existing models. A new eBAC model was developed to improve the estimation of BrAC by modeling effects of gender, weight, and the delay of BrAC measurement on the discrepancy. The validity of the model was tested and established with the data from the experiment conducted in this study and two published research studies, and compared with existing eBAC models.ResultsResults of the model validity examination indicated that the developed model had higher R squares and lower root-mean-squared errors (RMSE) in estimating BrAC in three experiments compared with the existing eBAC models, including the NHTSA equation, the Matthew equation, the Lewis equation, the Watson equation, and the Forrest equation.ConclusionThe developed eBAC model had a better performance of BrAC estimation compared with existing eBAC models. The validation of the model with the data from three empirical studies indicated a high level of generalizability in estimating BrAC.



http://ift.tt/2m7NNf7

Label and label-free based surface-enhanced Raman scattering for pathogen bacteria detection: A review

Publication date: 15 August 2017
Source:Biosensors and Bioelectronics, Volume 94
Author(s): Yu Liu, Haibo Zhou, Ziwei Hu, Guangxia Yu, Danting Yang, Jinshun Zhao
Rapid, accurate detection of pathogen bacteria is a highly topical research area for the sake of food safety and public health. Surface-enhanced Raman scattering (SERS) is being considered as a powerful and attractive technique for pathogen bacteria detection, due to its sensitivity, high speed, comparatively low cost, multiplexing ability and portability. This contribution aims to give a comprehensive overview of SERS as a technique for rapid detection of pathogen bacteria based on label and label-free strategies. A brief tutorial on SERS is given first of all. Then we summarize the recent trends and developments of label and label-free based SERS applied to detection of pathogen bacteria, including the relatively complete interpretation of SERS spectra. In addition, multifunctional SERS platforms for pathogen bacteria in matrix are discussed as well. Furthermore, an outlook of the work done and a perspective on the future directions of SERS as a reliable tool for real-time pathogen bacteria detection are given.



http://ift.tt/2mmUR7R

A survey on IVIVC/IVIVR development in the pharmaceutical industry – Past experience and current perspectives

Publication date: 1 May 2017
Source:European Journal of Pharmaceutical Sciences, Volume 102
Author(s): M.A. Nguyen, T. Flanagan, M. Brewster, F. Kesisoglou, S. Beato, J. Biewenga, J. Crison, R. Holm, R. Li, E. Mannaert, M. McAllister, M. Mueller-Zsigmondy, U. Muenster, K. Ojala, S. Page, A. Parr, S. Rossenu, P. Timmins, A. Van Peer, A. Vermeulen, P. Langguth
The present work aimed to describe the current status of IVIVC/IVIVR development in the pharmaceutical industry, focusing on the use and perception of specific approaches as well as successful and failed case studies. Two questionnaires have been distributed to 13 EFPIA partners of the Oral Biopharmaceutics Tools Initiative and to the Pharmacokinetics Working Party of the European Medicines Agency in order to capture the perspectives and experiences of industry scientists and agency members, respectively. Responses from ten companies and three European Agencies were received between May 21st 2014 and January 19th 2016. The majority of the companies acknowledged the importance of IVIVC/IVIVR throughout the drug development stages and a well-balanced rate of return on investment. However, the IVIVC/IVIVR approach seemed to be underutilized in regulatory submissions. Four of the ten companies stated to have an internal guidance related to IVIVC/IVIVR modelling, whereas three felt that an overall strategy is not necessary. Successful models mainly served to support formulation development and to provide a better mechanistic understanding. There was not yet much experience with safe-space IVIVRs as well as the use of physiologically based modelling in the field of IVIVC. At the same time, the responses from both industry and agencies indicated that there might be a need for a regulatory framework to guide the application of these novel approaches. The relevance of IVIVC/IVIVR for oral IR drug products was recognized by most of the companies. For IR formulations, relationships other than Level A correlation were more common outcomes among the provided case studies, such as multiple Level C correlation or safe-space IVIVR, which could be successfully used for requesting regulatory flexibility. Compared to the responses from industry scientists, there was a trend towards a higher appreciation of the BCS among the regulators, but a less positive attitude towards the utility of non-compendial dissolution methods for establishing a successful IVIVC/IVIVR. The lack of appropriate in vivo data and regulatory uncertainty were considered the major difficulties in IVIVC/IVIVR development. The results of this survey provide unique insights into current IVIVC/IVIVR practices in the pharmaceutical industry. Pursuing an IVIVC/IVIVR should be generally encouraged, considering its high value from both industry and regulators' perspective.

Graphical abstract

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Neonatal Diabetes and the KATP Channel: From Mutation to Therapy

Publication date: Available online 3 March 2017
Source:Trends in Endocrinology & Metabolism
Author(s): Frances M. Ashcroft, Michael C. Puljung, Natascia Vedovato
Activating mutations in one of the two subunits of the ATP-sensitive potassium (KATP) channel cause neonatal diabetes (ND). This may be either transient or permanent and, in approximately 20% of patients, is associated with neurodevelopmental delay. In most patients, switching from insulin to oral sulfonylurea therapy improves glycemic control and ameliorates some of the neurological disabilities. Here, we review how KATP channel mutations lead to the varied clinical phenotype, how sulfonylureas exert their therapeutic effects, and why their efficacy varies with individual mutations.



http://ift.tt/2mYGgwD

Surrogate end-points for overall survival in 22 neoadjuvant trials of gastro-oesophageal cancers

Publication date: May 2017
Source:European Journal of Cancer, Volume 76
Author(s): Fausto Petrelli, Gianluca Tomasello, Sandro Barni
BackgroundThe surrogacy between disease-free survival (DFS) and overall survival (OS) has been evaluated in patients with gastric cancer who received adjuvant chemotherapy. Similar analyses in patients who have undergone neoadjuvant chemoradiotherapy (CTRT) or chemotherapy (CT) for gastro-oesophageal (GE) cancer have not yet been performed.MethodsWe evaluated the correlation between DFS and pathologic complete response (pCR) with OS in patients with GE carcinomas enrolled in randomised studies. A weighted linear regression analysis was used to evaluate surrogacy. Correlations were evaluated by squared correlation R². Surrogacy of DFS and pCR with OS was assessed through the correlation between end-points and OS (individual-level surrogacy), and between the treatment effects on the end-points (trial-level surrogacy). Correlations were weighted by the number of patients in the intent-to-treat population.ResultsTwenty-two trials were included for a total of 4749 patients that received CTRT or CT for gastric or oesophageal cancers. Treatment effect on surrogates did not correlate with treatment effect on OS (R² = 0.27, and R² = 0.17, for DFS and pCR) at the trial level. In subgroup analysis surrogacy of DFS did not vary according to histology or treatment modality but was good in gastric cancer and poor in oesophageal cancers.ConclusionsDFS and pCR did not correlate with OS, and should not be used as surrogate end-points in patients with GE cancer who have undergone neoadjuvant therapy. OS should still represent the primary end-point to compare treatments in future randomised clinical trials.



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The prognostic and potentially predictive value of the Laurén classification in oesophageal adenocarcinoma

Publication date: May 2017
Source:European Journal of Cancer, Volume 76
Author(s): Rosa T. van der Kaaij, Petur Snaebjornsson, Francine E.M. Voncken, Jolanda M. van Dieren, Edwin P.M. Jansen, Karolina Sikorska, Annemieke Cats, Johanna W. van Sandick
AimTo investigate the histological subtypes of oesophageal adenocarcinoma according to the Laurén classification (intestinal/diffuse/mixed) in relation to tumour response to neoadjuvant treatment, and in relation to patients' survival after potentially curative treatment.MethodsData were collected from all oesophageal adenocarcinoma patients who underwent potentially curative treatment in our institute between 1998 and 2014. Treatment consisted of neoadjuvant chemoradiotherapy (36–50 Gy) followed by an oesophagectomy or definitive chemoradiotherapy (50–50.4 Gy). Clinical data were collected from patient records. All endoscopic biopsies and surgical resection specimens were reassessed to determine the histological subtype (intestinal, diffuse or mixed) and the Mandard tumour regression grade (TRG). The impact of the histological subtypes on survival was determined using a Cox model.ResultsMedian follow-up was 68 months. Diffuse and mixed type cancers accounted for 25% of oesophageal adenocarcinomas. Median overall survival differed significantly between patients with intestinal (n = 121, 39 months), diffuse (n = 28, 18 months) or mixed type (n = 11, 25 months) carcinomas (log rank, p = 0.023). In multivariable analysis, the diffuse type was associated with shorter survival (diffuse versus intestinal: hazard ratios 2.06, p = 0.006). A pathologically (near) complete response (TRG 1 or 2) was seen less frequently in diffuse type than in intestinal type carcinomas (24% versus 60%; p = 0.015).ConclusionsPatients with diffuse type oesophageal adenocarcinomas had a significantly worse prognosis than those with intestinal type carcinomas. Intestinal type carcinomas showed a better response to neoadjuvant chemoradiotherapy than diffuse type carcinomas. These differences call for the exploration of differentiated approaches in the potentially curative treatment of oesophageal adenocarcinomas.



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Accelerated partial breast irradiation using intensity modulated radiotherapy versus whole breast irradiation: Health-related quality of life final analysis from the Florence phase 3 trial

Publication date: May 2017
Source:European Journal of Cancer, Volume 76
Author(s): Icro Meattini, Calogero Saieva, Guido Miccinesi, Isacco Desideri, Giulio Francolini, Vieri Scotti, Livia Marrazzo, Stefania Pallotta, Fiammetta Meacci, Cristina Muntoni, Benedetta Bendinelli, Luis Jose Sanchez, Marco Bernini, Lorenzo Orzalesi, Jacopo Nori, Simonetta Bianchi, Lorenzo Livi
BackgroundAccelerated partial breast irradiation (APBI) represents a valid option for selected early breast cancer (BC). We recently published the 5-year results of the APBI-IMRT-Florence phase 3 randomised trial (NCT02104895), showing a very low rate of disease failure, with acute and early–late toxicity in favour of APBI. We present the early and 2-year follow-up health-related quality of life (HRQoL) results.MethodsEligible patients were women aged more than 40 years with early BC suitable for breast-conserving surgery. APBI consisted of 30 Gy in five fractions delivered with IMRT technique. Standard whole breast irradiation (WBI) consisted of 50 Gy in 25 fractions plus a 10 Gy in five fractions boost on tumour bed. A total of 520 patients were enrolled in the phase 3 trial. Overall, 205 patients (105 APBI and 100 WBI) fully completed all the given questionnaires and were therefore included in the present analysis. As HRQoL assessment, patients were asked to complete the European Organisation for Research and Treatment of Cancer QLQ-C30, and the BR23 questionnaires at the beginning (T0), at the end (T1) and after 2 years from radiation (T2).FindingsNo significant difference between the two arms at QLQ-C30 and BR23 scores emerged at T0. Global health status (p = 0.0001), and most scores of the functional and symptom scales of QLQ-C30 at T1 showed significant differences in favour of the APBI arm. Concerning the BR23 functional and symptom scales, the body image perception, future perspective and breast and arm symptoms were significantly better in the APBI group. Similar significant results emerged at T2: significant differences in favour of APBI emerged for GHS (p = 0.0001), and most functional and symptom QLQ-C30 scales. According to QLQ-BR23 module, among the functional scales, the body image perception and the future perspective were significantly better in the APBI group (p = 0.0001), whereas among the symptom scales significant difference emerged by breast and arm symptoms with better outcomes in APBI arm (p < 0.01).InterpretationEarly BC treated with APBI showed an improved short-term, and 2-year follow-up HRQoL outcome as compared with WBI. Early BC treated with APBI showed an improved short-term, and 2-year follow-up HRQoL outcome as compared with WBI. APBI should be strongly considered in the treatment choice for selected low-risk patients. Mature local control results from ongoing adequately powered randomised trials are awaited.



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Glucose Concentrations Modulate Brain-Derived Neurotrophic Factor Responsiveness of Neurons in the Paraventricular Nucleus of the Hypothalamus

Abstract

The hypothalamic paraventricular nucleus (PVN) is critical for normal energy balance and has been shown to contain high levels of both BDNF and TrkB mRNA. Microinjections of BDNF into the PVN increase energy expenditure, suggesting BDNF plays an important role in energy homeostasis through direct actions in this nucleus. The current studies were undertaken to examine the postsynaptic effects of BDNF on the membrane potential of PVN neurons, and to determine if extracellular glucose concentrations modulated these effects.

We used hypothalamic PVN slices from male Sprague-Dawley rats to perform whole cell current-clamp recordings from PVN neurons. BDNF was bath applied at a concentration of 2 nM and the effects on membrane potential determined. BDNF caused depolarizations in 54% of neurons (n = 25; mean ± standard error of the mean 8.9 ± 1.2 mV), hyperpolarizations in 23% (n = 11; -6.7 ± 1.4 mV), while the remaining cells were unaffected. These effects were maintained in the presence of tetrodotoxin (N = 9; 56% depolarized, 22% hyperpolarized, 22% non-responders), or the GABA_a antagonist bicuculline (N = 12; 42% depolarized, 17% hyperpolarized, 41% non-responders), supporting the conclusion that these effects on membrane potential were postsynaptic.

Current-clamp recordings from PVN neurons next examined effects of BDNF on these neurons at varying extracellular glucose concentrations. Larger proportions of PVN neurons hyperpolarized in response to BDNF as glucose concentrations decreased (10 mM glucose 23% (n = 11) of neurons hyperpolarized whereas at 0.2 mM glucose, 71% showed hyperpolarizing effects (n = 12)).

Our findings reveal that BDNF has direct GABA_A independent effects on PVN neurons, which are modulated by local glucose concentrations. The latter observation further emphasizes the critical importance of using physiologically relevant conditions for study of central pathways involved in the regulation of energy homeostasis.

This article is protected by copyright. All rights reserved.

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6-Hydroxy-5,7-dimethoxy-flavone suppresses the neutrophil respiratory burst via selective PDE4 inhibition to ameliorate acute lung injury

Publication date: Available online 3 March 2017
Source:Free Radical Biology and Medicine
Author(s): Yung-Fong Tsai, Tzu-Chi Chu, Wen-Yi Chang, Yang-Chang Wu, Fang-Rong Chang, Shun-Chin Yang, Tung-Ying Wu, Yu-Ming Hsu, Chun-Yu Chen, Shih-Hsin Chang, Tsong-Long Hwang
Over-activated neutrophils produce enormous oxidative stress and play a key role in the development of acute and chronic inflammatory diseases. 6-Hydroxy-5,7-dimethoxy-flavone (UFM24), a flavone isolated from the Annonaceae Uvaria flexuosa, showed inhibitory effects on human neutrophil activation and salutary effects on lipopolysaccharide (LPS)-induced acute lung injury (ALI) in mice. UFM24 potently inhibited superoxide anion (O2^•−) generation, reactive oxidants, and CD11b expression, but not elastase release, in N-formyl-l-methionyl-l-leucyl-l-phenylalanine (fMLF)-activated human neutrophils. However, UFM24 failed to scavenge O2^•− and inhibit the activity of subcellular NADPH oxidase. fMLF-induced phosphorylation of protein kinase B (Akt) was inhibited by UFM24. Noticeably, UFM24 increased cyclic adenosine monophosphate (cAMP) concentration and protein kinase (PK) A activity in activated human neutrophils. PKA inhibitors significantly reversed the inhibitory effects of UFM24, suggesting that the effects of UFM24 were through cAMP/PKA-dependent inhibition of Akt activation. Additionally, activity of cAMP-related phosphodiesterase (PDE)4, but not PDE3 or PDE7, was significantly reduced by UFM24. Furthermore, UFM24 attenuated neutrophil infiltration, myeloperoxidase activity, and pulmonary edema in LPS-induced ALI in mice. In conclusion, our data demonstrated that UFM24 inhibits oxidative burst in human neutrophils through inhibition of PDE4 activity. UFM24 also exhibited significant protection against endotoxin-induced ALI in mice. UFM24 has potential as an anti-inflammatory agent for treating neutrophilic lung damage.

Graphical abstract

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Mechanisms Governing Precise Protein Biotinylation

Publication date: Available online 3 March 2017
Source:Trends in Biochemical Sciences
Author(s): Louise M. Sternicki, Kate L. Wegener, John B. Bruning, Grant W. Booker, Steven W. Polyak
Protein biotinylation is a key post-translational modification found throughout the living world. The covalent attachment of a biotin cofactor onto specific metabolic enzymes is essential for their activity. This modification is distinctive, in that it is carried out by a single enzyme: biotin protein ligase (BPL), an enzyme that is able to biotinylate multiple target substrates without aberrant-off target biotinylation. BPL achieves this target selectivity by recognizing a sequence motif in the context of a highly conserved tertiary structure. One structural class of BPLs has developed an additional 'substrate verification' mechanism to further enable appropriate protein selection. This is crucial for the precise and selective biotinylation required for efficient biotin management, especially in organisms that are auxotrophic for biotin.



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Comparative effect of ZnO NPs, ZnO bulk and ZnSO4 in the antioxidant defences of two plant species growing in two agricultural soils under greenhouse conditions

Publication date: 1 July 2017
Source:Science of The Total Environment, Volume 589
Author(s): Concepción García-Gómez, Ana Obrador, Demetrio González, Mar Babín, María Dolores Fernández
The present study has investigated the toxicity of ZnO NPs to bean (Phaseolus vulgaris) and tomato (Solanum lycopersicon) crops grown to maturity under greenhouse conditions using an acidic (soil pH5.4) and a calcareous soil (soil pH8.3). The potentially available Zn in the soils and the Zn accumulation in the leaves from NPs applied to the soil (3, 20 and 225mgZnkg⁻¹) and changes in the chlorophylls, carotenoids and oxidative stress biomarkers were measured at 15, 30, 60 and 90days and compared with those caused by bulk ZnO and ZnSO4. The available Zn in the soil and the leaf Zn content did not differ among the Zn chemical species, except in the acidic soil at the highest concentration of Zn applied as Zn ions, where the highest values of the two variables were found. The ZnO NPs showed comparable Zn toxicity or biostimulation to their bulk counterparts and Zn salts, irrespective of certain significant differences suggesting a higher activity of the Zn ion. The treatments altered the photosynthetic pigment concentration and induced oxidative stress in plants. ROS formation was observed at Zn plant concentrations ranging from 590 to 760mgkg⁻¹, but the effects on the rest of the parameters were highly dependent on the plant species, exposure time and especially soil type. In general, the effects were higher in the acidic soil than in the calcareous soil for the bean and the opposite for the tomato. The similar uptakes and toxicities of the different Zn forms suggest that the Zn ions derived from the ZnO NPs exerted a preferential toxicity in plants. However, several results obtained in soils treated with NPs at 3mgZnkg⁻¹ soil indicated that may exist other underlying mechanisms related to the intrinsic nanoparticle properties, especially at low NP concentrations.

Graphical abstract

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Study of morphology and electrical properties of indium zinc oxide-modified kenaf fiber

Publication date: June 2017
Source:Industrial Crops and Products, Volume 100
Author(s): Edynoor bin Osman, Toshihiro Moriga, Kei-ichiro Murai, Mohd Warikh bin Abd Rashid
Indium zinc oxide (IZO) was successfully deposited onto kenaf fibers (KFs) by a dip-coating method. The novel aspect of this study was the investigation of the electrical conductivity of the resulting indium zinc oxide-modified kenaf fiber (KF-IZO) by emphasizing on its morphology and the dipping rate used for dip-coating. KF was alkalized using a 5% sodium hydroxide (NaOH) solution. The dipping rate was varied from 1 to 30mm/s. KF-IZO was then annealed at a temperature of 150°C for 4h. A modified four-probe method employing a copper metal attachment plate was used to evaluate the electrical properties of KF-IZO. A dipping rate of 5mm/s, which yielded the highest electrical conductivity of 11.81S/mm, was found to be optimum. Scanning Electron Microscope/Energy Dispersive Using X-Ray (SEM-EDX) analysis of KF-IZO revealed that the IZO film was uniformly coated on the KF substrates, and no significant thermal damage was observed. KF-IZO showed the potential to be used in smart textiles, electrostatic discharge protection, and as a reinforcement in composites.



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Effects and mechanism of diclofenac degradation in aqueous solution by US/Zn0

Publication date: July 2017
Source:Ultrasonics Sonochemistry, Volume 37
Author(s): Ting Huang, Guangming Zhang, Shan Chong, Yucan Liu, Nan Zhang, Shunyan Fang, Jia Zhu
A system of ultrasound radiation coupled with Zn⁰ was applied to degrade diclofenac. The effects of initial pH, dosage of Zn⁰ and ultrasound density were investigated. To further explore the mechanism of the microcosmic reaction, the fresh and used Zn⁰ powders were characterized by SEM, XRD and XPS. Radical scavengers were used to determine the oxidation performance of strong oxidizing free radicals on diclofenac, including hydroxyl radicals and superoxide radicals. The results showed that the optimum removal of diclofenac reached to over 85% at pH of 2.0 in 15min, with Zn⁰ dosage of 0.1g/L and ultrasound density of 0.6W/cm³. TOC removal of 72.6% in 15min and dechlorination efficiency of diclofenac reached 70% in 30min. Characterization results showed that a ZnO membrane was generated on the surface of Zn particles after use. According to the mass spectrometry results, several possible pathways of diclofenac degradation were proposed, and most diclofenac was turned into micro-molecules or CO2 finally. The synergistic effect of US/Zn⁰ in the reactions led to a proposed degradation mechanism in which zinc could directly attack the target contaminant diclofenac because of its good reducibility with the auxiliary functions of ultrasonic irradiation, mechanical shearing and free radical oxidation.



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Exploiting kinetics to unravel the role of a ZnO diluent in the production of CO via oxidizing Zn particles with CO2

Publication date: 29 June 2017
Source:Chemical Engineering Science, Volume 165
Author(s): David Weibel, Zoran R. Jovanovic, Aldo Steinfeld
Direct oxidation of pure Zn particles with CO2 is inhibited by an impervious ZnO scale. The presence of a ZnO diluent surface provides a site for an additional heterogeneous reaction of sublimated Zn that allows for a fast and high conversion of Zn. This is relevant to the efficient production of CO by the oxidation of Zn particles produced by the solar thermal dissociation of ZnO that are generally contaminated by the recombined ZnO. The overall reaction mechanism thus involves the sublimation of Zn(g) from the Zn surface, its transport to the ZnO diluent surface, and its subsequent heterogeneous reaction with CO2 on this surface. To elucidate the most relevant of those elementary steps different kinetic models were tested against a broad set of isothermal thermogravimetric data acquired at different temperatures, CO2-concentrations, and initial ZnO contents. The overall rate was found to be controlled by the transport of Zn(g) to the ZnO diluent surface and the reaction of the chemisorbed CO2 either with Zn(g) or with Zn incorporated from gas phase into the ZnO lattice surface sites. Increasing the initial content of ZnO diluent increases the effectiveness of the heterogeneous reaction at the ZnO diluent surface which facilitates the sublimation of Zn and appears to render the ZnO product scale surrounding unreacted Zn more permeable.

Graphical abstract

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Deactivation in the posterior mid-cingulate cortex reflects perceptual transitions during binocular rivalry: Evidence from simultaneous EEG-fMRI

Publication date: 15 May 2017
Source:NeuroImage, Volume 152
Author(s): Abhrajeet V. Roy, Keith W. Jamison, Sheng He, Stephen A. Engel, Bin He
Binocular rivalry is a phenomenon in which perception spontaneously shifts between two different images that are dichoptically presented to the viewer. By elucidating the cortical networks responsible for these stochastic fluctuations in perception, we can potentially learn much about the neural correlates of visual awareness. We obtained concurrent EEG-fMRI data for a group of 20 healthy human subjects during the continuous presentation of dichoptic visual stimuli. The two eyes' images were tagged with different temporal frequencies so that eye specific steady-state visual evoked potential (SSVEP) signals could be extracted from the EEG data for direct comparison with changes in fMRI BOLD activity associated with binocular rivalry. We additionally included a smooth replay condition that emulated the perceptual transitions experienced during binocular rivalry as a control stimulus. We evaluated a novel SSVEP-informed fMRI analysis in this study in order to delineate the temporal dynamics of rivalry-related BOLD activity from both an electrophysiological and behavioral perspective. In this manner, we assessed BOLD activity during rivalry that was directly correlated with peaks and crosses of the two rivaling, frequency-tagged SSVEP signals, for comparison with BOLD activity associated with subject reported perceptual transitions. Our findings point to a critical role of a right lateralized fronto-parietal network in the processing of bistable stimuli, given that BOLD activity in the right superior/inferior parietal lobules was significantly elevated throughout binocular rivalry and in particular during perceptual transitions, compared with the replay condition. Based on the SSVEP-informed analysis, rivalry was further associated with significantly enhanced BOLD suppression in the posterior mid-cingulate cortex during perceptual transitions, compared with SSVEP crosses. Overall, this work points to a careful interplay between early visual areas, the right posterior parietal cortex and the mid-cingulate cortex in mediating the spontaneous perceptual changes associated with binocular rivalry and has significant implications for future multimodal imaging studies of perception and awareness.



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Characterization of neural entrainment to speech with and without slow spectral energy fluctuations in laminar recordings in monkey A1

Publication date: 15 April 2017
Source:NeuroImage, Volume 150
Author(s): Benedikt Zoefel, Jordi Costa-Faidella, Peter Lakatos, Charles E. Schroeder, Rufin VanRullen
Neural entrainment, the alignment between neural oscillations and rhythmic stimulation, is omnipresent in current theories of speech processing – nevertheless, the underlying neural mechanisms are still largely unknown. Here, we hypothesized that laminar recordings in non-human primates provide us with important insight into these mechanisms, in particular with respect to processing in cortical layers. We presented one monkey with human everyday speech sounds and recorded neural (as current-source density, CSD) oscillations in primary auditory cortex (A1). We observed that the high-excitability phase of neural oscillations was only aligned with those spectral components of speech the recording site was tuned to; the opposite, low-excitability phase was aligned with other spectral components. As low- and high-frequency components in speech alternate, this finding might reflect a particularly efficient way of stimulus processing that includes the preparation of the relevant neuronal populations to the upcoming input. Moreover, presenting speech/noise sounds without systematic fluctuations in amplitude and spectral content and their time-reversed versions, we found significant entrainment in all conditions and cortical layers. When compared with everyday speech, the entrainment in the speech/noise conditions was characterized by a change in the phase relation between neural signal and stimulus and the low-frequency neural phase was dominantly coupled to activity in a lower gamma-band. These results show that neural entrainment in response to speech without slow fluctuations in spectral energy includes a process with specific characteristics that is presumably preserved across species.



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