Review: Bowel transit studies in children: evidence base,role and practicalities

Constipation is common in children and adults with varied worldwide prevalence. The majority of children have functional constipation as defined by Rome clinical criteria and respond favourably to standard medical therapy; up to one-third can develop difficult-to-treat constipation requiring investigation and specialist treatment. Colon function tests aim to assess the neuromuscular integrity, the movement of faeces across the colon and evaluate/predict response to the therapy. The ‘ideal’ test should be practical, non-invasive, widely available and cost-effective. None of the available diagnostic tools is designed to provide a comprehensive assessment of colon function and clinicians often have to combine more than one test to answer different questions. In this review, we aim to assess the strengths and limitations of the commonly available diagnostic investigations (radiopaque marker studies, scintigraphy, wireless motility capsule and colonic manometry) used to assess colon transit in children and to provide guidance on the most appropriate test for particular clinical settings.     

Sleep Deprivation: Effects on Weight Loss and Weight Loss Maintenance

This narrative review presents the findings from intervention studies on the effects of sleep deprivation on eating habits, metabolic rate, and the hormones regulating metabolism, and discusses their relevance to weight loss efforts. Disturbed sleeping patterns lead to increased energy intake, partly from excessive snacking, mainly on foods high in fat and carbohydrates. The studies focused mainly on the effects of sleep duration, but also of sleep quality, on dietary intake during weight loss trials, and on weight loss maintenance. It is important to explore sleep routines that could enhance the efforts of obese and overweight people to lose weight, maintain their weight loss, and improve their overall health.     

The role of capsule endoscopy in the detection of small bowel disease

Videocapsule endoscopy (VCE) can identify lesions in the small bowel which would otherwise be hard to detect. We have selected 53 patients with digestive symptoms in which upper and lower endoscopy had provided no findings. Patients were classified into three groups, based on their main indication for VCE exploration: group one--obscure gastrointestinal bleeding (OGIB); group two--unspecific abdominal symptoms; group 3--monitoring of a prior known pathology. We found that VCE has high predictive values, sensibility and specificity in the diagnosis of OGIB. VCE was also useful in the detection and extent evaluation of lesions in Crohn's and celiac disease. VCE is also able to detect tumors of the small bowel with sufficient accuracy, and can be used to monitor patients with hereditary pre-malignant diseases such as FAP. There were few light adverse effects and no major complications. We conclude that VCE is a safe and effective procedure for the detection of small bowel lesions.     

Comparative Study on Nutrition and Lifestyle of Information Technology Workers from Romania before and during COVID-19 Pandemic

The study aimed to evaluate lifestyle factors among Information Technology (IT) workers from Romania before and during the pandemic. We used an online applied questionnaire, filled in by 1638 respondents, that assessed nutrition status-Body Mass Index (BMI), weight and diet change, physical activity, alcohol consumption, number of hours working in front of the computer, stress, and sleep. Multivariate logistic regression was used to establish the lifestyle factors that lead to weight gain. Although the level of physical activity (PA) was low before the pandemic, the results of our study showed a further decrease in physical activity. In total, 61.1% of men and 71.1% of women performed PA for less than 30 min per day. Weight gain was reported in 50.5% of men and 45.3% of women (mean weight gain was 5.11 ± 3.52 kg) as a result of increased screen time (with a mean of 3.52 ± 4.29 for females and 3.05 ± 2.09 for males, p > 0.05 h per day) and the reported changes in diet. Despite the popularity of home-cooked foods, the intake of vegetables and fruit remained low. The quality of sleep was poor for 55.7% of the respondents. Public health and corporation policies are required to encourage a healthy lifestyle and avoid chronic diseases.     

Risk factors for surgical complications after central pancreatectomy

Background/Aims: Central pancreatectomy is a pancreas- sparing alternative to standard pancreatic resections in selected cases. Although associated with high morbidity, the risk factors for surgical complications of this procedure are not yet defined. Methodology: The clinicopathological and perioperative data of 24 patients who underwent central pancreatectomies (2002-2010) were correlated with surgical complications. Results: The overall morbidity rate was 54% (pancreatic fistula, 40%). In a univariate analysis, age over 40 years, body mass index ≥30kg/m2, smoking and American Society of Anesthesiologists III scores were significantly correlated with increased morbidity. In a multivariate analysis, a significant correlation with the development of complications was found for body mass index ≥30kg/m2 and age over 40 years. Conclusions: Certain patient-related factors (older age, obesity and smoking) appear to have a negative impact on early postoperative outcome after central pancreatectomy. For patients with these factors, an alternative distal pancreatectomy should be considered. Central pancreatectomy should be tailored not only to the pathology but also to the patient profile.     

Magnetoencephalographic evidence of the interhemispheric asymmetry in echoic memory lifetime and its dependence on handedness and gender

The echoic memory trace (EMT) refers to neuronal activity associated with the short-term retention of stimulus-related information, especially within the primary and association auditory cortex. Using magnetoencephalography it is possible to determine quantitatively the lifetime of the EMT. Previous studies assumed that each new stimulus drives the EMT to its full strength, which then passively decays. In this study we show the limitations of this assumption using trains of auditory stimuli designed specifically for computing the EMT lifetime and its contextual sensitivity. We estimated a time-dependent EMT using a data-driven approach, which allows contributions from a relatively wide area around the auditory cortex in our quantitative measures. We identified: (1) internally generated cortical activations during the silent period between stimuli well separated in time from each other, which had influence on the morphology of the neuromagnetic response to the next external stimulus; and (2) EMTs with different lifetimes that modulate the amplitude of the evoked responses at different latencies, suggesting the existence of multiple neural delay lines. Long EMT lifetimes were observed on the descending part of the M100 complex, which showed handedness and gender-dependent interhemispheric asymmetry. Specifically, all subjects showed longer EMT lifetimes on the left hemisphere, except left-handed males. Distributed source analysis of the data for one left- and one right-handed male subject identified a secondary generator in the right-handed subject, which was located posterior to the early primary generator and dominated the auditory response at late latencies, where EMT lifetime asymmetry was high. The identified multiple neural delay lines and their laterality may provide a link between macroneuronal activity and left hemisphere specialization for processing linguistic material.     

Absolute dose calculations for Monte Carlo simulations of radiotherapy beams

Monte Carlo (MC) simulations have traditionally been used for single field relative comparisons with experimental data or commercial treatment planning systems (TPS). However, clinical treatment plans commonly involve more than one field. Since the contribution of each field must be accurately quantified, multiple field MC simulations are only possible by employing absolute dosimetry. Therefore, we have developed a rigorous calibration method that allows the incorporation of monitor units (MU) in MC simulations. This absolute dosimetry formalism can be easily implemented by any BEAMnrc/DOSXYZnrc user, and applies to any configuration of open and blocked fields, including intensity-modulated radiation therapy (IMRT) plans. Our approach involves the relationship between the dose scored in the monitor ionization chamber of a radiotherapy linear accelerator (linac), the number of initial particles incident on the target, and the field size. We found that for a 10 x 10 cm2 field of a 6 MV photon beam, 1 MU corresponds, in our model, to 8.129 x 10(13) +/- 1.0% electrons incident on the target and a total dose of 20.87 cGy +/- 1.0% in the monitor chambers of the virtual linac. We present an extensive experimental verification of our MC results for open and intensity-modulated fields, including a dynamic 7-field IMRT plan simulated on the CT data sets of a cylindrical phantom and of a Rando anthropomorphic phantom, which were validated by measurements using ionization chambers and thermoluminescent dosimeters (TLD). Our simulation results are in excellent agreement with experiment, with percentage differences of less than 2%, in general, demonstrating the accuracy of our Monte Carlo absolute dose calculations.     

The polyomavirus BK large T-antigen-derived peptide elicits an HLA-DR promiscuous and polyfunctional CD4+ T-cell response

BK virus (BKV) nephropathy and hemorrhagic cystitis are increasingly recognized causes of disease in renal and hematopoietic stem cell transplant recipients, respectively. Functional characterization of the immune response to BKV is important for clinical diagnosis, prognosis, and vaccine design. A peptide mix (PepMix) and overlapping (OPP) or random (RPP) peptide pools derived from BKV large T antigen (LTA) were used to restimulate 14-day-expanded peripheral blood mononuclear cells (PBMC) from 27 healthy control subjects in gamma interferon (IFN-γ)-specific enzyme-linked immunospot (ELISPOT) assays. A T-cell response to LTA PepMix was detected in 15/27 subjects. A response was frequently observed with peptides derived from the helicase domain (9/15 subjects), while the DNA binding and host range domains were immunologically inert (0/15 subjects). For all nine subjects who responded to LTA peptide pools, the immune response could be explained largely by a 15-mer peptide designated P313. P313-specific CD4(+) T-cell clones demonstrated (i) stringent LTA peptide specificity; (ii) promiscuous recognition in the context of HLA-DR alleles; (iii) cross recognition of homologous peptides from the polyomavirus simian virus 40 (SV40); (iv) an effector memory phenotype, CD107a expression, and intracellular production of IFN-γ and tumor necrosis factor alpha (TNF-α); (v) cytotoxic activity in a chromium release assay; and (vi) the ability to directly present cognate antigen to autologous T cells. In conclusion, T-cell-mediated immunity to BKV in healthy subjects is associated with a polyfunctional population of CD4(+) T cells with dual T-helper and T-cytotoxic properties. HLA class II promiscuity in antigen presentation makes the targeted LTA peptide sequence a suitable candidate for inclusion in immunotherapy protocols.     

A technique for generating phase-space-based Monte Carlo beamlets in radiotherapy applications

As radiotherapy treatment planning moves toward Monte Carlo (MC) based dose calculation methods, the MC beamlet is becoming an increasingly common optimization entity. At present, methods used to produce MC beamlets have utilized a particle source model (PSM) approach. In this work we outline the implementation of a phase-space-based approach to MC beamlet generation that is expected to provide greater accuracy in beamlet dose distributions. In this approach a standard BEAMnrc phase space is sorted and divided into beamlets with particles labeled using the inheritable particle history variable. This is achieved with the use of an efficient sorting algorithm, capable of sorting a phase space of any size into the required number of beamlets in only two passes. Sorting a phase space of five million particles can be achieved in less than 8 s on a single-core 2.2 GHz CPU. The beamlets can then be transported separately into a patient CT dataset, producing separate dose distributions (doselets). Methods for doselet normalization and conversion of dose to absolute units of Gy for use in intensity modulated radiation therapy (IMRT) plan optimization are also described.     

Repair of the femoral nerve by two motor branches of the obturator nerve: A case report

Complete femoral nerve palsies are uncommon but devastating injuries when they are caused by large nerve defects. Direct repair is usually not possible and nerve grafting renders uncertain outcomes. Recent studies proposed different peripheral nerve transfers as treatment strategies for large femoral nerve defects. We report a clinical application of a nerve transfer to reinnervate the quadriceps muscle with two motor branches of the obturator nerve in a 48 years-old man that was diagnosed with a femoral nerve palsy after resection of a retroperitoneal schwannoma. The branches supplying the gracilis and adductor longus muscles were transferred to the motor branch of the femoral nerve to the quadriceps muscle at 6 months postinjury. At 34 months of follow-up, knee extension was quoted M4. The presented nerve transfer may be feasible, technically simple, and renders good functional outcomes.