A Geant4 simulation code for simulating optical photons in SPECT scintillation detectors

Geant4 is an object oriented toolkit created for the simulation of High-Energy Physics detectors. Geant4 allows an accurate modeling of radiation sources and detector devices, with easy configuration and friendly interface and at the same time with great accuracy in the simulation of physical processes. While most Monte Carlo codes do not allow the simulation of the transport and boundary characteristics for optical photons transport generated by scintillating crystal, Geant4 allows the simulation of the optical photons. In this paper we present an application of the Geant4 program for simulating optical photons in SPECT cameras. We aim to study the light transport within scintillators, photomultiplier tubes and coupling devices. To this end, we simulated a detector based on a scintillator, coupled to a photomultiplier tube through a glass window. We compared simulated results with experimental data and theoretical models, in order to verify the good matching with our simulations. We simulated a pencil beam of 140 keV photons impinging the crystal at different locations. For each condition, we calculated the value of the Pulse Height Centroid and the spread of the charge distribution, as read out by the anode array of the photomultiplier. Finally, the spatial and the energy resolutions of the camera have been estimated by simulated data. In all cases, we found that simulations agree very well with experimental data

Bone turnover markers in sheep and goat: a review of the scientific literature

Bone turnover markers (BTMs) are product of bone cell activity and are generally divided in bone formation and bone resorption markers. The purpose of this review was to structure the available information on the use of BTMs in studies on small ruminants, especially for monitoring their variations related to diet, exercise, gestation and metabolic lactation state, circadian and seasonal variations, and also during skeletal growth. Pre-clinical and translational studies using BTMs with sheep and goats as animal models in orthopaedic research studies to help in the evaluation of the fracture healing process and osteoporosis research are also described in this review. The available information from the reviewed studies was systematically organized in order to highlight the most promising BTMs in small ruminant research, as well as provide a wide view of the use of sheep and goat as animal models in orthopaedic research, type of markers and commercial assay kits with cross-reactivity in sheep and goat, method of sample and storage of serum and urine for bone turnover markers determination and the usefulness and limitations of bone turnover markers in the different studies, therefore an effective tool for researchers that seek answers to different questions while using BTMs in small ruminants.José Arthur de A. Camassa acknowledges to the Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq), Brazil, for his PhD scholarship 202248/2015-1.info:eu-repo/semantics/publishedVersio

Sexual Dysfunction after Elective Endovascular or Hand-Assisted Laparoscopic Abdominal Aneurysm Repair

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HPLC analysis of HbA1c in dried blood spot samples (DBS): a reliable future for diabetes monitoring

To simplify collection and transport of blood for HbA1c measuring, we have studied the use of a special paper that absorbs a defined volume of capillary blood and quickly dries it (dried blood-spot, DBS). The DBS can be sent to a central laboratory using regular postal service and without temperature control. This system differs greatly from other proposed DBS methods for HbA1c because it overcomes the haemoglobin alterations during the drying and storing processes, that otherwise make this analysis unreliable. We have developed a special treatment of the paper before collection that stabilises the HbA1c molecule excellently in dried blood samples, allowing accurate HPLC analysis even two weeks after collection. This method has been applied in a "blind" study in which HbA1c values determined in 97 DBS coming from an hospital diabetes care centre were compared with those obtained from parallel venous blood samples

Effect of ranitidine on the absorption of aspirin

Six healthy male volunteers received 1 week's pretreatment with ranitidine, 150 mg twice daily, and placebo in a double-blind cross-over trial. On the 8th day, each volunteer received 1 g of aspirin in order to study the pharmacokinetics of this nonsteroidal anti-inflammatory drug. The results of this study suggest that ranitidine does not induce clinically significant alterations to the kinetics of a single dose of aspirin in healthy males

Do clinicopathological features of the cancer patient relate with nipple areolar complex necrosis in nipple-sparing mastectomy?

BACKGROUND: The selections of nipple-sparing mastectomy (NSM) are principally depending on oncologic indication and oncologic safety. The main complication of NSM is nipple areolar complex (NAC) necrosis, and it is usually related to surgical technique. However, the patients' clinicopathological factors should be also considered. METHOD: We retrospectively reviewed 934 consecutive NSM patients during 2002-2007 at the European Institute of Oncology, Milan, Italy. We identified a group of patient who had NAC excision because of NAC necrosis and compared this group with those who had successful NAC conservation. We analyzed the association between the risk of NAC necrosis and the clinicopathological features of the patients. RESULTS: Among 934 NSM, 772 were invasive cancers and 162 were in situ cancers. Of the 934, 40 NAC (4.2%) were removed during the postoperative period because of necrosis. When we considered age, BMI, menopausal status, smoking status, tumor size, axillary lymph node status, in situ or invasive cancer histology, presence of extensive situ component, grading, estrogen receptor, progesterone receptor, HER2/neu overexpression, Ki-67 proliferative index, and peritumoral vascular invasion, no association was observed between patients' clinicopathological features and NAC necrosis incidence. CONCLUSIONS: In our study, clinicopathological features have no significant impact on necrosis complication in therapeutic NSMs. Positive retroareolar margin is the risk of necrosis. Further studies are required to avoid bias due to the different cancer treatments such as different reconstruction techniques and intraoperative radiation protocols. The correlation between breast morphology and NAC necrosis should also be investigated in the future

Verification of a Blood-Based Targeted Proteomics Signature for Malignant Pleural Mesothelioma

BACKGROUND We have verified a mass spectrometry (MS)-based targeted proteomics signature for the detection of malignant pleural mesothelioma (MPM) from the blood. METHODS A seven-peptide biomarker MPM signature by targeted proteomics in serum was identified in a previous independent study. Here, we have verified the predictive accuracy of a reduced version of that signature, now composed of six-peptide biomarkers. We have applied liquid chromatography-selected reaction monitoring (LC-SRM), also known as multiple-reaction monitoring (MRM), for the investigation of 402 serum samples from 213 patients with MPM and 189 cancer-free asbestos-exposed donors from the United States, Australia, and Europe. RESULTS Each of the biomarkers composing the signature was independently informative, with no apparent functional or physical relation to each other. The multiplexing possibility offered by MS proteomics allowed their integration into a single signature with a higher discriminating capacity than that of the single biomarkers alone. The strategy allowed in this way to increase their potential utility for clinical decisions. The signature discriminated patients with MPM and asbestos-exposed donors with AUC of 0.738. For early-stage MPM, AUC was 0.765. This signature was also prognostic, and Kaplan-Meier analysis showed a significant difference between high- and low-risk groups with an HR of 1.659 (95% CI, 1.075-2.562; P = 0.021). CONCLUSIONS Targeted proteomics allowed the development of a multianalyte signature with diagnostic and prognostic potential for MPM from the blood. IMPACT The proteomic signature represents an additional diagnostic approach for informing clinical decisions for patients at risk for MPM