Soil erosion control, plant diversity, and arthropod communities under heterogeneous cover crops in an olive orchard

Abstract

A 3-year experiment compared in an olive orchard the effect of different cover crops' composition on runoff, water erosion, diversity of annual plants, and arthropod communities which could provide an alternative to conventional management based on tillage (CT). The cover crops evaluated were a seeded homogeneous grass (GC), a seeded mix of ten different species (MC_seeded), and a non-seeded cover by vegetation naturally present at the farm after 20 years of mowing (MC_natural). The results suggest that heterogeneous cover crops can provide a viable alternative to homogeneous ones in olives, providing similar benefits in reducing runoff and soil losses compared to management based on bare soil. The reduction in soil loss was particularly large: 46.7 in CT to 6.5 and 7.9 t ha⁻¹ year⁻¹ in GC and MC_seeded, respectively. The heterogeneous cover crops resulted in greater diversity of plant species and a modification of the arthropod communities with an increased number of predators for pests. The reduction of the cost of implanting heterogeneous cover crops, improvement of the seeding techniques, and selection of species included in the mixes require additional research to promote the use of this practice which can deliver enhanced environmental benefits.

http://ift.tt/2jKDkFc

Long-term follow-up and role of FDG PET in advanced pancreatic neuroendocrine patients treated with 177 Lu-D OTATATE

Abstract

Purpose

Lu-DOTATATE (Lu-PRRT) is a valid therapeutic option in differentiated pancreatic neuroendocrine tumors (P-NETs). FDG PET seems to be an important prognostic factor in P-NETs. We evaluated the efficacy of Lu-PRRT and the role of FDG PET in 60 patients with advanced P-NETs.

Methods

From March 2008 to June 2011, 60 consecutive patients with P-NETs were enrolled in the study. Follow-up lasted until March 2016. Eligible patients were treated with two different total cumulative activities (18.5 or 27.8 GBq in 5 cycles every 6–8 weeks), according to kidney and bone marrow parameters.

Results

Twenty-eight patients received a mean full activity (FA) of 25.9 GBq and 32 a mean reduced activity (RA) of 18.5 GBq. The disease control rate (DCR), defined as the sum of CR+PR+SD was 85.7 % in the FA group and 78.1 % in the RA group. Median progression-free survival (mPFS) was 53.4 months in the FA group and 21.7 months in the RA group (P = 0.353). Median overall survival (mOS) was not reached (nr) in FA patients and was 63.8 months in the RA group (P = 0.007). Fifty-five patients underwent an FDG PET scan before Lu-PRRT, 32 (58 %) showing an increased FDG uptake in tumor sites. mPFS was 21.1 months in FDG PET-positive patients and 68.7 months in the FDG PET-negative group (P < 0.0002), regardless of the total activity administered.

Conclusion

Both FA and RA are active in patients undergoing Lu-PRRT. However, an FA of 27.8 GBq of Lu-PRRT prolongs PFS and OS compared to an RA of 18.5 GBq. Our results indicate that FDG PET is an independent prognostic factor in this patient setting.

http://ift.tt/2kLLmeG

Erratum to: The need of standardization and of large clinical studies in an emerging indication of [18 F]FDG PET: the autoimmune encephalitis

http://ift.tt/2kKwRLW

Asymmetric relapse of an HIV-associated Kaposi sarcoma

http://ift.tt/2kM4qcq

Positron emission tomography in amyotrophic lateral sclerosis: Towards targeting of molecular pathological hallmarks

Abstract

During the past decades, extensive efforts have been made to expand the knowledge of amyotrophic lateral sclerosis (ALS). However, clinical translation of this research, in terms of earlier diagnosis and improved therapy, remains challenging. Since more than 30% of motor neurons are lost when symptoms become clinically apparent, techniques allowing non-invasive, in vivo detection of motor neuron degeneration are needed in the early, pre-symptomatic disease stage. Furthermore, it has become apparent that non-motor signs play an important role in the disease and there is an overlap with cognitive disorders, such as frontotemporal dementia (FTD). Radionuclide imaging, such as positron emission tomography (PET) and single-photon emission computed tomography (SPECT), form an attractive approach to quantitatively monitor the ongoing neurodegenerative processes. Although [¹⁸F]-FDG has been recently proposed as a potential biomarker for ALS, active targeting of the underlying pathologic molecular processes is likely to unravel further valuable disease information and may help to decipher the pathogenesis of ALS. In this review, we provide an overview of radiotracers that have already been applied in ALS and discuss possible novel targets for in vivo imaging of various pathogenic processes underlying ALS onset and progression.

http://ift.tt/2kKt0yy

Radiosynoviorthesis in hemophilic arthropathy: pathologic blood pool imaging on pre-therapeutic bone scintigraphy is not a predictor of treatment success

Abstract

Purpose

Increased articular ^99mTc MDP uptake on blood pool imaging (BPI) of patients with rheumatologic conditions is indicative of active inflammatory changes, and has been suggested as a strong predictor of response to radiosynoviorthesis (RSO). In this study, we aimed to assess the value of pretreatment BPI positivity (i.e. scintigraphic-apparent hyperemia) for successful RSO in hemophilic arthropathy.

Methods

Thirty-four male patients with painful hemophilic arthropathy underwent RSO after failure of conservative treatment. Treated joints comprised the knee in eight, elbow in five, and ankle in 21 patients. Pretreatment triple-phase bone scintigraphy showed hyperemic joints (pathologic BPI) in 17 patients, whereas 17 patients had no increased tracer uptake on BPI. Response to RSO was evaluated 6 months post-treatment by measuring changes in intensity of arthralgia according to the visual analog scale (VAS), bleeding frequency, and range of motion. The association between hyperemia (pathologic BPI) and treatment outcome was examined using nonparametric tests for independent samples.

Results

Clinically evident pain relief occurred in 26 patients (76.5 %), and the mean VAS decreased from 7.7 ± 1.1 to 4.6 ± 2.7 (p < 0.001). Joint bleeding frequency (hemarthrosis) decreased from 4.5 ± 0.6 to 2.1 ± 0.4 during the first 6 months after RSO (p < 0.001). For both parameters (pain relief and bleeding frequency), patients experienced a similar benefit from RSO regardless of pretreatment BPI: arthralgia (p = 0.312) and frequency of hemarthrosis (p = 0.396). No significant improvement was observed for range of motion, but it was significantly more restricted in hyperemic joints both before (p = 0.036) and after treatment (p = 0.022).

Conclusions

Hemophilic arthropathy can be effectively treated with RSO regardless of pre-therapeutic BPI. Patients in whom articular hyperemia is not detectable by scintigraphy may have similar (outstanding) outcomes, and thus should not be excluded from treatment.

http://ift.tt/2kLYbW8

The need of standardization and of large clinical studies in an emerging indication of [ 18 F]FDG PET: the autoimmune encephalitis

http://ift.tt/2kKBgyF

A systematic review of lessons learned from PET molecular imaging research in atypical parkinsonism (Niccolini and Politis, 2016)

http://ift.tt/2kLTAU3

**-Postprandial pancreatic [ 11 C]methionine uptake after pancreaticoduodenectomy mirrors basal beta cell function and insulin release

Abstract

Purpose

[S-methyl-¹¹C]-L-methionine ([¹¹C]MET) uptake in the pancreas might be a central indicator of beta cell function. Since gastric emptying was recently shown to influence glycemic control in subjects after pancreaticoduodenectomy (PD, the surgical treatment of neoplasms of the pancreas head), we looked for imaginable relationships between gastric emptying, pre- and postprandial insulin concentrations, and [¹¹C]MET uptake.

Methods

Nineteen tumor-free survivors after PD (age mean ± SD: 61 ± 8.7 yrs.; 10 male, 9 female) and 10 healthy controls (age: 27 ± 8.7 yrs.; 7 male, 3 female) were given a mixed test meal. One gram of paracetamol was ingested with the meal to evaluate the speed of gastric emptying. Insulin, glucose, and paracetamol plasma concentrations were measured before and over 180 minutes after ingestion. Beta cell function was calculated from fasting glucose and insulin plasma concentrations. Simultaneously, 800 MBq of [¹¹C]MET were administered and the activity (maximum tissue standardized uptake values [SUVmax]) over the pancreas was measured at 15, 30, and 60 minutes after injection. Total integrated SUVmax (area under the curve [AUC]) and incremental SUVmax were calculated.

Results

The uptake of [¹¹C]MET in the pancreas was significantly higher (p < 0.0001) in controls compared to the PD group. Gastric emptying was significantly slower in controls compared to pancreatectomy subjects (p < 0.0001). Paracetamol AUC₃₀ correlated with the SUVmax increment between 15 and 30 minutes (R² = 0.27, p = 0.0263), suggesting a relationship between gastric emptying and the uptake of [¹¹C]MET. Total integrated SUVmax correlated with insulin AUC₆₀ (R² = 0.66,p < 0.0001) in patients after PD. Multivariate regression analysis revealed insulin AUC₆₀ and beta cell function, calculated from the fasting insulin to glucose ratio, as independent predictors of ¹¹C-methionine uptake, i.e. total integrated SUVmax, in patients after PD (R² = 0.78, p < 0.0001).

Conclusion

Postprandial [¹¹C]MET uptake may represent basal and postprandial beta cell function. The findings suggest a possible usefulness of this imaging procedure for further studying beta cell function.

http://ift.tt/2kKG2wf

A systematic review of lessons learned from PET molecular imaging research in atypical parkinsonism

http://ift.tt/2kM4mJI

Erratum to: Role of PET/CT in malignant pediatric lymphoma

http://ift.tt/2kKDC0e

William C. Klingesmith III: The Mathematics and Biology of the Biodistribution of Radiopharmaceuticals: A Clinical Perspective

http://ift.tt/2kLQdN0

Computed-tomography-guided anatomic standardization for quantitative assessment of dopamine transporter SPECT

Abstract

Purpose

For the quantitative assessment of dopamine transporter (DAT) using [¹²³I]FP-CIT single-photon emission computed tomography (SPECT) (DaTscan), anatomic standardization is preferable for achieving objective and user-independent quantification of striatal binding using a volume-of-interest (VOI) template. However, low accumulation of DAT in Parkinson's disease (PD) would lead to a deformation error when using a DaTscan-specific template without any structural information. To avoid this deformation error, we applied computed tomography (CT) data obtained using SPECT/CT equipment to anatomic standardization.

Methods

We retrospectively analyzed DaTscan images of 130 patients with parkinsonian syndromes (PS), including 80 PD and 50 non-PD patients. First we segmented gray matter from CT images using statistical parametric mapping 12 (SPM12). These gray-matter images were then anatomically standardized using the diffeomorphic anatomical registration using exponentiated Lie algebra (DARTEL) algorithm. Next, DaTscan images were warped with the same parameters used in the CT anatomic standardization. The target striatal VOIs for decreased DAT in PD were generated from the SPM12 group comparison of 20 DaTscan images from each group. We applied these VOIs to DaTscan images of the remaining patients in both groups and calculated the specific binding ratios (SBRs) using nonspecific counts in a reference area. In terms of the differential diagnosis of PD and non-PD groups using SBR, we compared the present method with two other methods, DaTQUANT and DaTView, which have already been released as software programs for the quantitative assessment of DaTscan images.

Results

The SPM12 group comparison showed a significant DAT decrease in PD patients in the bilateral whole striatum. Of the three methods assessed, the present CT-guided method showed the greatest power for discriminating PD and non-PD groups, as it completely separated the two groups.

Conclusion

CT-guided anatomic standardization using the DARTEL algorithm is promising for the quantitative assessment of DaTscan images.

http://ift.tt/2kKAEcc

“la synoviorthèse” can more than synovitis!

http://ift.tt/2kM4clW

FDG-PET imaging to detect and characterize infectious disorders; an unavoidable path for the foreseeable future

http://ift.tt/2kKAgKK

Intraindividual tumor heterogeneity in NET – Further insight by C-X-C motif chemokine receptor 4-directed imaging

http://ift.tt/2kM0rwx

Lymphoma: current status of clinical and preclinical imaging with radiolabeled antibodies

Abstract

Lymphoma is a complex disease that arises from cells of the immune system with an intricate pathology. While lymphoma may be classified as Hodgkin or non-Hodgkin, each type of tumor is genetically and phenotypically different and highly invasive tissue biopsies are the only method to investigate these differences. Noninvasive imaging strategies, such as immunoPET, can provide a vital insight into disease staging, monitoring treatment response in patients, and dose planning in radioimmunotherapy. ImmunoPET imaging with radiolabeled antibody-based tracers may also assist physicians in optimizing treatment strategies and enhancing patient stratification. Currently, there are two common biomarkers for molecular imaging of lymphoma, CD20 and CD30, both of which have been considered for investigation in preclinical imaging studies. In this review, we examine the current status of both preclinical and clinical imaging of lymphoma using radiolabeled antibodies. Additionally, we briefly investigate the role of radiolabeled antibodies in lymphoma therapy. As radiolabeled antibodies play critical roles in both imaging and therapy of lymphoma, the development of novel antibodies and the discovery of new biomarkers may greatly affect lymphoma imaging and therapy in the future.

http://ift.tt/2kKvUmP

Intra-lesional spatial correlation of static and dynamic FET-PET parameters with MRI-based cerebral blood volume in patients with untreated glioma

Abstract

Purpose

¹⁸F-fluorethyltyrosine-(FET)-PET and MRI-based relative cerebral blood volume (rCBV) have both been used to characterize gliomas. Recently, inter-individual correlations between peak static FET-uptake and rCBV have been reported. Herein, we assess the local intra-lesional relation between FET-PET parameters and rCBV.

Methods

Thirty untreated glioma patients (27 high-grade) underwent simultaneous PET/MRI on a 3 T hybrid scanner obtaining structural and dynamic susceptibility contrast sequences. Static FET-uptake and dynamic FET-slope were correlated with rCBV within tumour hotspots across patients and intra-lesionally using a mixed-effects model to account for inter-individual variation. Furthermore, maximal congruency of tumour volumes defined by FET-uptake and rCBV was determined.

Results

While the inter-individual relationship between peak static FET-uptake and rCBV could be confirmed, our intra-lesional, voxel-wise analysis revealed significant positive correlations (median r = 0.374, p < 0.0001). Similarly, significant inter- and intra-individual correlations were observed between FET-slope and rCBV. However, rCBV explained only 12% of the static and 5% of the dynamic FET-PET variance and maximal overlap of respective tumour volumes was 37% on average.

Conclusions

Our results show that the relation between peak values of MR-based rCBV and static FET-uptake can also be observed intra-individually on a voxel basis and also applies to a dynamic FET parameter, possibly determining hotspots of higher biological malignancy. However, just a small part of the FET-PET signal variance is explained by rCBV and tumour volumes determined by the two modalities showed only moderate overlap. These findings indicate that FET-PET and MR-based rCBV provide both congruent and complimentary information on glioma biology.

http://ift.tt/2kM4rNL

Influence of blood-brain barrier permeability on O-(2- 18 F-fluoroethyl)-L-tyrosine uptake in rat gliomas

Abstract

Purpose

O-(2-¹⁸F-fluoroethyl)-L-tyrosine (¹⁸F-FET) is an established tracer for the diagnosis of brain tumors with PET. This study investigates the influence of blood-brain barrier (BBB) permeability on ¹⁸F-FET uptake in two rat glioma models and one human xenograft model.

Methods

F98 glioma, 9L gliosarcoma or human U87 glioblastoma cells were implanted into the striatum of 56 Fischer or RNU rats. Thereafter, animals were divided into a control group and a group receiving injections of the glucocorticoid dexamethasone (Dex). After 12-13 days of tumor growth animals received injection of Evans blue dye (EBD) to visualize BBB disturbance and underwent ¹⁸F-FET PET followed by autoradiography. Time activity curves, standardized uptake values (SUV) and Tumor-to-brain ratios (TBR) of ¹⁸F-FET uptake [18-61 min post injection (p.i.)] were evaluated using a volume-of-Interest (VOI) analysis. BBB disturbance was quantitatively evaluated by EBD fluorescence. The membrane gaps of blood vessel endothelial tight junctions were measured using electron microscopy to visualize ultrastructural BBB alterations in one untreated and one Dex treated F98 glioma. Data were analyzed by two-way ANOVAs.

Results

In Dex treated animals EBD extravasation was significantly reduced in 9L (P < 0.001) and U87 (P = 0.008) models and showed a trend in F98 models (P = 0.053). In contrast, no significant differences of ¹⁸F-FET uptake were observed between Dex treated animals and control group except a decrease of the TBR in the 9L tumor model in PET (P < 0.01). Ultrastructural evaluation of tumor blood vessel endothelia revealed significant reduction of the cleft diameter between endothelial cells after Dex treatment in F98 model (P = 0.010).

Conclusion

Despite a considerable reduction of BBB permeability in rat gliomas after Dex treatment, no relevant changes of ¹⁸F-FET uptake were noted in this experimental study. Thus, ¹⁸F-FET uptake in gliomas appears to be widely independent of the permeability of the BBB.

http://ift.tt/2kKABNy

The prognostic and predictive value of sstr 2 -immunohistochemistry and sstr 2 -targeted imaging in neuroendocrine tumors

Abstract

Purpose

Our aim was to assess the prognostic and predictive value of somatostatin receptor 2 (sstr₂) in neuroendocrine tumors (NETs).

Methods

We established a tissue microarray and imaging database from NET patients that received sstr₂-targeted radiopeptide therapy with yttrium-90-DOTATOC, lutetium-177-DOTATOC or alternative treatment. We used univariate and multivariate analyses to identify prognostic and predictive markers for overall survival, including sstr₂-imaging and sstr₂-immunohistochemistry.

Results

We included a total of 279 patients. In these patients, sstr₂-immunohistochemistry was an independent prognostic marker for overall survival (HR: 0.82, 95 % CI: 0.67 – 0.99, n = 279, p = 0.037). In DOTATOC patients, sstr₂-expression on immunohistochemistry correlated with tumor uptake on sstr₂-imaging (n = 170, p < 0.001); however, sstr₂-imaging showed a higher prognostic accuracy (positive predictive value: +27 %, 95 % CI: 3 – 56 %, p = 0.025). Sstr₂-expression did not predict a benefit of DOTATOC over alternative treatment (p = 0.93).

Conclusions

Our results suggest sstr₂ as an independent prognostic marker in NETs. Sstr₂-immunohistochemistry correlates with sstr₂-imaging; however, sstr₂-imaging is more accurate for determining the individual prognosis.

http://ift.tt/2kLYeRS