Occurrence, sources and effects of polycyclic aromatic hydrocarbons in the Tunis lagoon, Tunisia: an integrated approach using multi-level biological responses in Ruditapes decussatus

Abstract

Coastal lagoons are critical ecosystems presenting a strategic economic importance, but they are subjected to potential anthropogenic impact. As part of the Tunis lagoon (Tunisia) biomonitoring study, levels, composition pattern and sources of polycyclic aromatic hydrocarbons (PAHs) in surface sediments along with their bioavailability in clam Ruditapes decussatus were investigated in polluted (S2–S4) and reference (S1) sites. In order to investigate the contamination effects at different biological levels in clams, a wide set of biomarkers, including gene expression changes, enzymatic activities disruption and histopathological alterations, was analysed. Biomarkers were integrated in a biomarker index (IBR index) to allow a global assessment of the biological response. Principal component analysis (PCA) was used for chemical and biological data integration to rank the sampling sites according to their global environmental quality. Sediment PAHs levels ranged between 144.5 and 3887.0 ng g⁻¹ dw in the Tunis lagoon sites versus 92.6 ng g⁻¹ dw in the reference site. The high PAH concentrations are due to anthropogenic activities around the lagoon. PAH composition profiles and diagnostic isomer ratios analysis indicated that PAHs were of both pyrolitic and petrogenic origins. Clams sampled from S2 and S3 exhibited the highest PAH contents with 2192.6 ng g⁻¹ dw and 2371.4 ng g⁻¹ dw, respectively. Elevated levels of tissue PAHs were associated to an increase in biotransformation and antioxidant activities, and lipid peroxidation levels along with an overexpression of different genes encoding for general stress response, mitochondrial metabolism and antioxidant defence, in addition to the emergence of severe and diverse histopathological alterations in the clams' digestive glands. IBR index was suitable for sampling sites ranking (S1 = 0 < S4 = 0.4 < S3 = 1.15 < S2 = 1.27) based on the level of PAH-induced stress in clams. PCA approach produced two components (PC1, 83.8% and PC2, 12.2%) that describe 96% of the variance in the data and thus highlighted the importance of integrating contaminants in sediments, their bioaccumulation and a battery of biomarkers of different dimensions for the assessment of global health status of coastal and lagoon areas.

http://bit.ly/2CDcw1O

Evaluation of the antifungal activity of individual and combined monoterpenes against Rhizopus stolonifer and Absidia coerulea

Abstract

The development of natural plant extracts and essential oils will help to decrease the negative effects of synthetic chemicals. In the present study, the antifungal activity of individual and combined monoterpenes against Rhizopus stolonifer and Absidia coerulea was evaluated. The results from antifungal tests showed that eugenol, carvacrol, and isoeugenol, among all the tested compounds, exhibited strong antifungal activity against the two tested fungi. Furthermore, carvacrol exhibited the most toxic effects against R. stolonifer and A. coerulea, and the IC₅₀ values of carvacrol for the two fungi were 44.94 μg/ml and 50.83 μg/ml, respectively. The compounds (±)-menthol, b-citronellol, geraniol, 3,7-dimethyl-1-octanol, citral, and cuminaldehyde had only strong antifungal activity against R. stolonifer. In addition, the value of the synergistic co-efficient (SR) of a combination of isoeugenol and eugenol (1:1) showed an additive effect against R. stolonifer. The combination of isoeugenol and cuminaldehyde (1:1) showed an antagonistic effect against A. coerulea. Our results indicated that carvacrol and isoeugenol had potential antifungal effects against the two tested fungi and could be utilized in novel biological fungicide development.

http://bit.ly/2UajrXl

Interactive effect of potassium and flyash: a soil conditioner on metal accumulation, physiological and biochemical traits of mustard ( Brassica juncea L.)

Abstract

At present plants continuously bare to various environmental stresses due to the rapid climate change that adversely affects the growth and nutrient status of the soil and plant. Application of flyash (FA) in combination with potassium (K) fertilizer amendment improves soil physico-chemical characteristics, growth and yield of plants. Mustard grown in combination with FA (0, 20, 40 or 60 t ha⁻¹) and K (0, 30 or 60 kg ha⁻¹) treated soil was used to evaluate the effect on heavy metals (Cd, Cr and Pb) concentration and antioxidant system. The experiment was conducted in a net house of the Department of Botany, Aligarh Muslim University, Aligarh. Sampling was done at 70 DAS. The results showed that concentration of metals was found maximum in roots than the leaf and seeds. FA₆₀ accompanied by K₃₀ and K₆₀ cause oxidative stress through lipid peroxidation and showed reduced levels of photosynthesis and enzymatic activity. Proline and ascorbate content increases with increasing flyash doses to combat stress. However, flyash at the rate of 40 t ha⁻¹ together with K₆₀ followed by K₃₀ significantly boosted crop growth by enhancing antioxidant activity which plays a critical role in ameliorating the oxidative stress.

Graphical abstract

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http://bit.ly/2DtkpZ9

A simple code for efficient indicative number recording with e-logbook

Although e-logbook was a welcome addition to surgical training many years ago its interface and functionality has not changed for many years. Multiple edits may be required if, for example, procedures have been miscoded or wrongly imported from the ISCP logbook. Accurate coding of operations on the e-logbook is important to correctly demonstrate meeting the required indicative numbers. A workout for facilitating the process of multiple procedures editing or adding complications is suggested. It is hoped that sharing this simple to apply computer code will help trainees to more efficiently utilise the e-logbook recording system to ensure accurate reflection of indicative procedural numbers.

http://bit.ly/2U6rAw2

Predictive value of FHIT, p27, and pERK1/ERK2 in salivary gland carcinomas: a retrospective study

Abstract

Objectives

The aim of this study was to investigate the predictive value of the biomarkers FHIT, p27, and pERK1/ERK2 in salivary gland carcinomas.

Material and methods

Immunohistochemical staining of FHIT, p27, and pERK1/ERK2 of 265 patients with salivary gland carcinomas was conducted, and associations with clinico-histopathological data, overall survival, and disease-specific survival were examined.

Results

Expression of FHIT (quick score 98.7 vs. 206.4) and p27 (QS 187.3 vs. 244.8) was significantly lower in carcinomas compared to non-tumor control tissue. Loss of FHIT frequently occurred in ACC (55.2%), SDC (68.2%), and SCC (100%). In the totality of tumors, loss of FHIT expression was found in 46.7% (106/227) and was significantly associated with advanced T stage and UICC stage, high-grade histology, loss of p27, PI3K, and survivin. FHIT positivity went along with significantly better overall and disease-specific survival. Negativity of p27 occurred in 28.7% (70/244) of tumors, particularly in SDC (54.4%) and SCC (50%). In the totality of tumors, p27 was associated with advanced patient age, high-grade histology, PI3K, survivin as well as better overall and disease-specific survival (p < 0.05). Positive pERK1/ERK2 expression correlated with positive survivin expression but did not affect overall survival in the totality of tumors. In mucoepidermoid carcinomas, pERK1/ERK2 expression was associated with low-grade malignancy, positive nuclear survivin, and better disease-specific survival.

Conclusions

Loss of FHIT and p27 characterizes aggressive tumor growth and unfavorable prognosis in salivary gland cancer.

Clinical relevance

The results may help to stratify patient-specific therapies according to individual tumor characteristics.

http://bit.ly/2FZLXr5

Fludroxycortide cream as an alternative therapy for actinic cheilitis

Abstract

Objectives

The objective of the study is to assess, by clinical follow-up, the efficacy of the dermatological cream Fludroxycortide 0.125 mg/g (Drenison®) in the treatment of actinic cheilitis (AC).

Material and methods

Twenty-three patients diagnosed with AC participated in the study. Fifteen were submitted to corticotherapy with Fludroxycortide, applied three times a day for up to 6 weeks, associated with lip sunscreen (LS) before sun exposure. In the control group of eight patients, only the use of LS was established. At each weekly return, a photographic record was made of the lesion. After treatment, images were evaluated and scores were assigned to verify clinical evolution. Also, patients treated with Fludroxycortide responded to a questionnaire, to assess drug tolerability and treatment satisfaction.

Results

In the group treated with Fludroxycortide (n = 15), five patients showed total improvement, seven presented partial improvement, and three showed no clinical change. Concerning the patients treated with LS (n = 8), one presented total remission of the clinical lesion characteristics, four exhibited partial improvement, and three exhibited no clinical lip alteration. No case presented symptom worsening. Of the 15 patients undergoing corticotherapy, 12 were satisfied and reported that the product was not irritating and contributed to lesion improvement.

Conclusions

Conventional treatment with LS was effective in the remission of some AC lesions, but treatment responses were improved when associated with Fludroxycortide, especially in the more severe cases.

Clinical relevance

As it is a non-invasive therapy leading, in most cases, to adequate clinical results, safety, and tolerability, Fludroxycortide can be considered an effective alternative treatment for AC.

http://bit.ly/2FLmphI

Scanning electron microscopy analysis of aligner fitting on anchorage attachments

Abstract

Purpose

The aims of the study were (1) to evaluate the fitting of three different aligners (Invisalign [Align Technology, Santa Clara, CA, USA], CA Clear Aligner [Scheu-Dental, Iserlohn, Germany] and F22 [Sweden&Martina, Due Carrare, Italy]) on anchorage attachments using scanning electron microscopy (SEM), and (2) to analyze the influence of 2 different types of resin used to build attachments on aligner fitting.

Methods

Using STL files of a patient, six resin casts were obtained and rectangular attachments were bonded on them. Conventional bulk-fill resin was used to build upper attachments while a flowable resin was used to build the lower ones. Passive aligners were adapted on each cast and then sectioned buccolingually. Microphotographs of the obtained sections were performed using a SEM and then micrometric measurements of aligner fitting on anchorage attachments were recorded.

Results

Analyzing the overall fitting of upper arch aligners, Invisalign provided a significantly better fitting with respect to F22 (P = 0.009); differences were not significant when comparing Invisalign with CA Clear Aligner, and CA Clear Aligner with F22. Analyzing the overall fitting of lower arch aligners, F22 provided a significantly better fitting with respect to CA Clear Aligner (P = 0.008) and Invisalign (P = 0.011). The analysis showed a significantly better fitting on upper attachments, built using conventional bulk-fill resin (P = 0.034).

Conclusions

Invisalign, CA Clear Aligner and F22 have comparable performance in terms of fitting on anchorage attachments. Conventional bulk-fill resin provides the best fitting on anchorage attachments.

http://bit.ly/2UdLC82

Following in the footsteps of Hippocrates—interrelation between the incidence of odontogenic abscess and meteorological parameters

Abstract

Objectives

Although many physicians in daily practice assume a connection between odontogenic infections and meteorological parameters, this has not yet been scientifically proven. Therefore, the aim of the present study was to evaluate the incidence of odontogenic abscess (OA) in relation to outdoor temperature and atmospheric pressure.

Patients and methods

An analysis of patients with an odontogenic abscess who presented at the emergency department within a period of 24 months was performed. Only patients who had not received surgical or antibiotic treatment prior to presentation and who lived in Berlin/Brandenburg were included. The OA incidence was correlated with the mean/maximum outdoor temperature and atmospheric pressure starting from 14 days before presentation. The statistical analysis was carried out using Poisson regression models with OA incidence as dependent and meteorological parameters as independent variables.

Results

A total of 535 patients (mean age 39.4 years; range 1 to 95 years) with 538 cases were included. Of these, 227 were hospitalized. The most frequent diagnosis was a canine fossa abscess. A significant association between mean (p = 0.0153) and maximum temperature (p = 0.008) on the day of the presentation and abscess incidence was observed. Furthermore, a significant correlation between OA incidence and maximum temperature 2 days before presentation was found (p = 0.034). The deviation of the mean temperature on the day of the presentation from the monthly mean temperature had a significant influence (p = 0.021) on the incidence of OA. In contrast to temperature, atmospheric pressure had no significant influence on the incidence of OA.

Conclusion

This study supports a relationship between the incidence of odontogenic abscess and outdoor temperature, but not atmospheric pressure. A significantly higher frequency of patients with an OA presented at our emergency department on days with (comparably) low and high outdoor temperatures. Furthermore, a significant correlation between incidence and maximum temperature 2 days before presentation was found.

Clinical relevance

The treatment of odontogenic infections has become a significant economic burden to public health care facilities. The results of this study may help to adapt the numbers of doctors/dentists on duty in relation to different weather conditions. In any case, it is an impetus to think outside the box.

http://bit.ly/2DwwFIv

Scanning electron microscopy analysis of aligner fitting on anchorage attachments

Abstract

Purpose

The aims of the study were (1) to evaluate the fitting of three different aligners (Invisalign [Align Technology, Santa Clara, CA, USA], CA Clear Aligner [Scheu-Dental, Iserlohn, Germany] and F22 [Sweden&Martina, Due Carrare, Italy]) on anchorage attachments using scanning electron microscopy (SEM), and (2) to analyze the influence of 2 different types of resin used to build attachments on aligner fitting.

Methods

Using STL files of a patient, six resin casts were obtained and rectangular attachments were bonded on them. Conventional bulk-fill resin was used to build upper attachments while a flowable resin was used to build the lower ones. Passive aligners were adapted on each cast and then sectioned buccolingually. Microphotographs of the obtained sections were performed using a SEM and then micrometric measurements of aligner fitting on anchorage attachments were recorded.

Results

Analyzing the overall fitting of upper arch aligners, Invisalign provided a significantly better fitting with respect to F22 (P = 0.009); differences were not significant when comparing Invisalign with CA Clear Aligner, and CA Clear Aligner with F22. Analyzing the overall fitting of lower arch aligners, F22 provided a significantly better fitting with respect to CA Clear Aligner (P = 0.008) and Invisalign (P = 0.011). The analysis showed a significantly better fitting on upper attachments, built using conventional bulk-fill resin (P = 0.034).

Conclusions

Invisalign, CA Clear Aligner and F22 have comparable performance in terms of fitting on anchorage attachments. Conventional bulk-fill resin provides the best fitting on anchorage attachments.

http://bit.ly/2UdLC82

Phthalate exposure and cumulative risk in a Chinese newborn population

Abstract

Phthalates have been attracted as a considerable attention in toxicological research as well as public health context due to their ubiquitous occurrence and potential adverse health effects. Newborns are susceptible to the environmental risk factors; however, data are still limited on newborn phthalate exposure and risk assessment worldwide, especially in China. This study was nested in a cross-sectional retrospective study of 1359 pregnant women recruited in Xiamen Maternity and Child Care Hospital, China, during June to July 2012. All urine samples from newborn were collected using disposal diapers during the first two postnatal days, and seven phthalate metabolites were measured by LC-ESI-MS/MS. Phthalate exposure and accumulation risk were evaluated based on the measured newborn urinary internal doses. The detection rate (96.5%) and the median concentration (17.5 ng/mL) of mono-n-butyl phthalate (MBP) were the highest, while monobenzyl phthalate (MBzP) concentration was the lowest with a detection rate (1.50%). By estimating the daily intakes of the parent phthalates, their EDI were 0.04, 0.10, 0.32, 0.00, and 0.12 μg/kg-bw/day for dimethyl phthalate (DMP), diethyl phthalate (DEP), di-n-butyl phthalates (DBP), benzyl butyl phthalate (BBzP), and di-(2-ethylhexyl) phthalate (DEHP), respectively. The newborns were commonly exposed to phthalates but no one exceeds the regulated tolerable daily intake (TDI) values in this large newborn population.

http://bit.ly/2sGcJNf

Topical Retinoids in Acne Vulgaris: A Systematic Review

Abstract

Background

Topical retinoids are a first-line treatment for acne vulgaris.

Objective

This systematic review aims to evaluate the efficacy, safety, and tolerability of topical retinoids approved in the United States for the treatment of acne vulgaris.

Methods

A PubMed and Embase search was conducted using the search terms 'adapalene,' 'tretinoin,' 'tazarotene,' and 'acne vulgaris.' Selection of articles fit the following inclusion criteria: clinical trials evaluating both efficacy and safety/tolerability of topical retinoids approved in the United States for the treatment of acne vulgaris and published between January 1, 2008 and September 1, 2018. Exclusion criteria included clinical trials involving 20 subjects or fewer, subjects under 12 years of age, and topical retinoid combination therapies with moisturizers or aloe vera. Of 424 search results found, a total of 54 clinical trials were chosen based on selection criteria.

Results

Topical retinoids are superior to vehicle in improving Investigator Global Assessment and Investigator's Static Global Assessment (24.1–28.8% and 13.3–17.3%, respectively; p < 0.001). A topical retinoid combined with benzoyl peroxide led to IGA improvement compared with vehicle (26.1–34.9% vs 7–11.8%; p < 0.001) at Week 12. Topical retinoid plus an oral antibiotic was superior to vehicle in reducing lesion counts (64–78.9% vs 41–56.8%, p < 0.001). There was no significant difference in efficacy between tretinoin and tazarotene. Tretinoin 0.05% resulted in 62% of patients experiencing AEs compared with adapalene 0.1% (19%) and adapalene 0.3% (40%). More patients receiving adapalene were tolerant of the AEs compared with tazarotene (55.4% vs 24.4%; p < 0.0012).

Conclusions

Topical retinoids are safe and efficacious for the treatment of acne vulgaris. They should be used in combination with benzoyl peroxide to optimize results in patients. The differences in efficacy of topical retinoids appears minor; therefore, the type of topical retinoid is not as important as choosing a particular strength of topical retinoid and combining it with an antimicrobial agent. Adapalene has a superior tolerability profile amongst topical retinoids.

http://bit.ly/2AZ4DUa

Alterations in the intestinal microbiota of patients with severe and active Graves’ orbitopathy: a cross-sectional study

Abstract

Background

The intestinal microbiota was linked to autoimmune diseases. Graves' orbitopathy (GO) is an autoimmune disease that is usually associated with Graves' disease. However, information on the microbiome of GO patients is yet lacking.

Objectives

To investigate whether GO patients differ from healthy controls in the fecal microbiota.

Design

A cross-sectional study.

Setting

33 patients with severe and active GO and 32 healthy controls of Han nationality were enrolled between March 2017 and March 2018.

Methods

The Gut microbial communities of the fecal samples of GO patients and healthy controls were analyzed and compared by 16S rRNA gene sequencing.

Results

Community diversity (Simpson and Shannon) was significantly reduced in fecal samples from patients with GO as compared to controls (p < 0.05). The similarity observed while assessing the community diversity (PCoA) proposed that the microbiota of patients with GO differ significantly from those of controls (p < 0.05). At the phyla levels, the proportion of Bacteroidetes increased significantly in patients with GO (p < 0.05), while at the genus and species levels, significant differences were observed in the bacterial profiles between the two groups (p < 0.05).

Limitations

Single-centered study design and limited fecal samples.

Conclusions

The present study indicated distinctive features of the gut microbiota in GO patients. The study provided evidence for further exploration in the field of intestinal microbiota with respect to the diagnosis and treatment of GO patients by modifying the microbiota profile.

http://bit.ly/2R8IacL

A comparative study on the photo-catalytic degradation of Cytarabine anticancer drug under Fe 3+/ H 2 O 2 , Fe 3+/ S 2 O 8 2− , and [Fe(C 2 O 4 ) 3 ] 3− /H 2 O 2 processes. Kinetics, identification, and in silico toxicity assessment of generated transformation products

Abstract

Cytarabine (CY) is an anticancer drug which has been identified in wastewater influents, effluents, and surface waters. In the present study, the degradation of CY under simulated solar light (SSL), by photo-Fenton (Fe³⁺/H₂O₂/SSL) and photo-Fenton-like processes (Fe³⁺/S₂O₈²⁻/SSL and [Fe(C₂O₄)₃]³⁻/H₂O₂/SSL), was investigated. The major parameters affecting the applied treatments (e.g., concentration of CY, Fe³⁺, H₂O₂, and S₂O₈²⁻) were optimized and CY's complete removal was achieved within 45 min for all techniques used. Mineralization studies indicated that [Fe(C₂O₄)₃]³⁻/H₂O₂/SSL treatment was the most efficient procedure since faster kinetics are achieved and higher mineralization percentage is reached compared to the other techniques used. Furthermore, 12 transformation products (TPs) were identified during the applied processes, by high resolution mass spectrometry, four of which were identified for the first time, indicating that CY molecule undergoes hydroxylation and subsequent oxidation, during the applied processes. Moreover, predictions of acute and chronic ecotoxicity of CY and its TPs on fish, daphnia, and green algae were conducted, using in silico quantitative structure activity relationship (QSAR) calculations. According to these predictions, the TPs generated during the studied treatments may pose a threat to aquatic environment. Finally, the efficiency of CY degradation by photo-Fenton and photo-Fenton-like treatment in real wastewater was evaluated, under the optimized conditions, which resulted in lower degradation rate constants compared to ultrapure water.

http://bit.ly/2FUpmMf

Therapeutic effects of the selective farnesoid X receptor agonist obeticholic acid in a monocrotaline-induced pulmonary hypertension rat model

Abstract

Background

Activation of the farnesoid X receptor (FXR), a member of the nuclear receptor steroid superfamily, leads to anti-inflammatory and anti-fibrotic effects in several tissues, including the lung. We have recently demonstrated a protective effect of the farnesoid X receptor (FXR) agonist obeticholic acid (OCA) in rat models of monocrotaline (MCT)-induced pulmonary arterial hypertension (PAH) and bleomycin-induced pulmonary fibrosis. The aim of the present study was to investigate whether the positive effects of OCA treatment could be exerted also in established MCT-induced PAH, i.e., starting treatment 2 weeks after MCT administration.

Methods

Rats with MCT-induced PAH were treated, 2 weeks after MCT administration, with OCA or tadalafil for two additional weeks. Pulmonary functional tests were performed at week 2 (before treatment) and four (end of treatment). At the same time points, lung morphological features and expression profile of genes related to smooth muscle relaxation/contraction and tissue remodeling were also assessed.

Results

2 weeks after MCT-induced injury, the treadmill resistance (a functional parameter related to pulmonary hypertension) was significantly decreased. At the same time point, we observed right ventricular hypertrophy and vascular remodeling, with upregulation of genes related to inflammation. At week 4, we observed a further worsening of the functional and morphological parameters, accompanied by dysregulation of inflammatory and extracellular matrix markers mRNA expression. Administration of OCA (3 or 10 mg/kg/day), starting 2 weeks after MCT-induced injury, significantly improved pulmonary function, effectively normalizing the exercise capacity. OCA also reverted most of the lung alterations, with a significant reduction of lung vascular wall thickness, right ventricular hypertrophy, and restoration of the local balance between relaxant and contractile pathways. Markers of remodeling pathways were also normalized by OCA treatment. Notably, results with OCA treatment were similar, or even superior, to those obtained with tadalafil, a recently approved treatment for pulmonary hypertension.

Conclusions

The results of this study demonstrate a significant therapeutic effect of OCA in established MCT-induced PAH, improving exercise capacity associated with reduction of right ventricular hypertrophy and lung vascular remodeling. Thus, OCA dosing in a therapeutic protocol restores the balance between relaxant and contractile pathways in the lung, promoting cardiopulmonary protective actions in MCT-induced PAH.

http://bit.ly/2sFf7np

From sensory circumventricular organs to cerebral cortex: neural pathways controlling thirst and hunger

Abstract

Much progress has been made during the past thirty years elucidating neural and endocrine pathways by which bodily needs for water and energy are brought to conscious awareness through the generation of thirst and hunger. One way that circulating hormones influence thirst and hunger is by acting on neurons within sensory circumventricular organs (CVOs). This is possible because the subfornical organ and organum vasculosum of the lamina terminalis (OVLT), the sensory CVOs in the forebrain, and the area postrema in the hindbrain, lack a normal blood‐brain barrier so that neurons within them are exposed to blood‐borne agents. The neural signals generated by hormonal action in these sensory CVOs are relayed to several sites in the cerebral cortex to stimulate or inhibit thirst or hunger. The subfornical organ and OVLT respond to circulating angiotensin II, relaxin and hypertonicity to drive thirst‐related neural pathways; whereas circulating amylin, leptin and possibly GLP‐1, act at the area postrema to influence neural pathways inhibiting food intake.

As a result of investigations using functional brain imaging techniques, the insula and anterior cingulate cortex, as well as several other cortical sites, have been implicated in the conscious perception of thirst and hunger in humans. Viral tracing techniques show that the anterior cingulate cortex and insula receive neural inputs from thirst related neurons in the subfornical organ and OVLT, hunger‐related neurons in the area postrema have polysynaptic efferent connections to these cortical regions. For thirst, the median preoptic nucleus initially, and thereafter the thalamic paraventricular nucleus and lateral hypothalamus have been identified as likely sites of synaptic links in pathways from subfornical organ and OVLT to the cortex. The challenge remains to identify the links in the neural pathways that relay signals originating in sensory CVOs to cortical sites subserving either thirst or hunger.

This article is protected by copyright. All rights reserved.

http://bit.ly/2WcVYqj

A fiber coherence index for quality control of B-table orientation in diffusion MRI scans

Publication date: Available online 22 January 2019

Source: Magnetic Resonance Imaging

Author(s): Kurt G. Schilling, Fang-Cheng Yeh, Vishwesh Nath, Colin Hansen, Owen Williams, Susan Resnick, Adam W. Anderson, Bennett A. Landman

Abstract

Purpose

The diffusion MRI "b-vector" table describing the diffusion sensitization direction can be flipped and permuted in dimension due to different orientation conventions used in scanners and incorrect or improperly utilized file formats. This can lead to incorrect fiber orientation estimates and subsequent tractography failure. Here, we present an automated quality control procedure to detect when the b-table is flipped and/or permuted incorrectly.

Methods

We define a "fiber coherence index" to describe how well fibers are connected to each other, and use it to automatically detect the correct configuration of b-vectors. We examined the performance on 3981 research subject scans (Baltimore Longitudinal Study of Aging), 1065 normal subject scans of high image quality (Human Connectome Project), and 202 patient scans (Vanderbilt University Medical Center), as well as 9 in-vivo and 9 ex-vivo animal data.

Results

The coherence index resulted in a 99.9% (3979/3981) and 100% (1065/1065) success rate in normal subject scans, 98% (198/202) in patient scans, and 100% (18/18) in both in-vivo and ex-vivo animal data in detecting the correct gradient table in datasets without severe image artifacts. The four failing cases (4/202) in patient scans, and two failures in healthy subject scans (2/3981), all showed prominent motion or signal dropout artifacts.

Conclusions

The fiber coherence measure can be used as an automatic quality assurance check in any diffusion analysis pipeline. Additionally, the success of this fiber coherence measure suggests potential broader applications, including evaluating data quality, or even providing diagnostic value as a biomarker of white matter integrity.

http://bit.ly/2Duzry8

Development of a Novel Approach to Studying Corneodesmosomes and Stratum Corneum Adhesion: Extending Knowledge on the Pathophysiology of Sensitive Skin

Background/Aims: Aberrant skin barrier and intercorneocyte adhesion are potential contributors to the pathomechanism of sensitive skin (SS). Here we aimed to develop a novel and easy-to-apply method to analyze corneodesmosomes and to interrogate potential differences between corneocytes of subjects with SS and non-SS (NSS). Methods: Corneocytes of the volar forearm and upper outer quadrant of the left buttock of SS (n = 10) and NSS (n = 8) subjects were extracted as a function of depth using adhesive tape and stained with anti-desmoglein 1 (DSG1) antibody. The total area of corneocytes and the number and average size of cells per tape was estimated using image processing. Results: The total area of extracted corneocytes and the quantity of DSG1 decreased with depth. The level of decrease, total area of corneocytes, and average area of individual cells differed between anatomical locations. In SS, a larger total area of extracted corneocytes and a larger average cell size per tape was found at all inspected depths. Conclusion: The developed novel and easy-to-apply approach allows investigation of corneodesmosome components. We confirm a role of altered corneocytes in the pathomechanism of SS. The disclosed protocol can further be optimized in studies of skin conditions with strongly affected corneodesmosomes.
Skin Pharmacol Physiol 2019;32:81–93

http://bit.ly/2HnW4YO

Abnormal fronto-striatal intrinsic connectivity reflects executive dysfunction in alcohol use disorders

Publication date: Available online 23 January 2019

Source: Cortex

Author(s): Caterina Galandra, Gianpaolo Basso, Marina Manera, Chiara Crespi, Ines Giorgi, Giovanni Vittadini, Paolo Poggi, Nicola Canessa

Abstract

The neural bases of cognitive impairment(s) in alcohol use disorders (AUDs) have been explained either with the specific involvement of frontal regions mostly affected by alcohol neurotoxic effects, or with a global brain damage underlying different neuro-cognitive alterations. Novel insights into this issue might come from the analysis of resting-state brain activity, representing a baseline level of intrinsic connectivity within and between the networks underlying cognitive performance.

We thus addressed the neural bases of cognitive impairment(s) in 22 AUD patients, compared with 18 healthy controls, by coupling resting-state fMRI with an in-depth neuropsychological assessment of the main cognitive domains. We assessed a relationship between AUD patients' cognitive impairment and two complementary facets of intrinsic brain functioning, i.e. intensity of activation and functional network connectivity, related to the strength of connectivity within and between resting-state networks, respectively.

Alcoholic patients' decreased cognitive performance involved specifically an executive domain associated with attentional and working-memory tasks. This impairment reflected an abnormal relationship, in patients vs. controls, between cognitive performance and the intensity of intrinsic activity in the dorsolateral prefrontal and striatal nodes of the executive control network. Functional connectivity between the same structures was positively correlated with executive performance in the whole sample, but significantly reduced in patients.

The present data suggest that AUD patients' executive impairment reflects dysfunctional connectivity between the cortical and subcortical nodes of the networks underlying cognitive control on goal-directed behavior. This evidence provides a baseline for future studies addressing the abnormal neural architecture underlying cognitive impairment in AUDs and the outcome of rehabilitative treatment.

http://bit.ly/2U9HjKM

“Looks familiar, but I do not know who she is”: The role of the anterior right temporal lobe in famous face recognition

Publication date: Available online 23 January 2019

Source: Cortex

Author(s): Valentina Borghesani, Jared Narvid, Giovanni Battistella, Wendy Shwe, Christa Watson, Richard J. Binney, Virginia Sturm, Zachary Miller, Maria Luisa Mandelli, Bruce Miller, Maria Luisa Gorno-Tempini

Abstract

Processing a famous face involves a cascade of steps including detecting the presence of a face, recognizing it as familiar, accessing semantic/biographical information about the person, and finally, if required, production of the proper name. Decades of neuropsychological and neuroimaging studies have identified a network of occipital and temporal brain regions ostensibly comprising the 'core' system for face processing. Recent research has also begun to elucidate upon an 'extended' network, including anterior temporal and frontal cortex. However, there is disagreement about which brain areas are involved in each step, as many aspects of face processing occur automatically in healthy individuals and rarely dissociate in patients. Moreover, some common phenomena are not easily induced in an experimental setting, such as having a sense of familiarity without being able to recall who the person is. Patients with the semantic variant of Primary Progressive Aphasia (svPPA) often recognize a famous face as familiar, even when they cannot specifically recall the proper name or biographical details. In this study, we analyzed data from a large sample of 105 patients with neurodegenerative disorders, including 43 svPPA, to identify the neuroanatomical substrate of three different steps of famous face processing. Using voxel-based morphometry, we correlated whole-brain grey matter volumes with scores on three experimental tasks that targeted familiarity judgment, semantic/biographical information retrieval, and naming. Performance in naming and semantic association significantly correlate with grey matter volume in the left anterior temporal lobe, whereas familiarity judgment with integrity of the right anterior middle temporal gyrus. These findings shed light on the neuroanatomical substrates of key components of overt face processing, addressing issues of functional lateralization, and deepening our understanding of neural substrates of semantic knowledge.

http://bit.ly/2DtEONL

The role of the hippocampus in weighting expectations during inference under uncertainty

Publication date: Available online 23 January 2019

Source: Cortex

Author(s): Francesco Rigoli, Jochen Michely, Karl J. Friston, Raymond J. Dolan

Abstract

Making inference under uncertainty requires an optimal weighting of prior expectations and observations. How this weighting is realized in the brain remains elusive. To investigate this, we recorded functional neuroimaging data while participants estimated a number based on noisy observations. Crucially, the prior expectation about the variability of observations (an expected variability) was manipulated. Consistent with normative models, when novel observations were characterized by higher expected or observed variability, participants' estimates relied more on expectations than novel observations and were characterized by higher stochasticity. Activity in hippocampus increased when novel evidence was characterized by higher expected or observed variability. Response in superior parietal cortex reflected a precision-weighted prediction error signal (i.e., the distance between observations and expectations) that was modulated by hippocampal activity. Our findings implicate the hippocampus during inference under uncertainty, suggesting a role in weighting prior representations over observations and in modulating responsivity of superior parietal cortex to prediction error.

http://bit.ly/2Uf4Km5