Hypocretin/orexin modulates body weight and the metabolism of glucose and insulin

The hypocretin/orexin (Hcrt/orexin) unit affects the functions of the nervous, cardiovascular, gastrointestinal, and reproductive systems. Hcrt/orexin ligands and receptors have been localized to different parts of the central and peripheral nervous systems, cerebrospinal fluid and blood, exocrine (pancreas, salivary, lacrimal) as well as endocrine (pancreatic islets, pituitary, adrenal) glands. Several factors including stress, glucagon‐like peptide‐1 agonists, glutamate, nicotine, glucose, and hypoglycaemia stimulate the expression of Hcrt/orexin system, but it is inhibited by ageing, bone morphogenetic protein, hypoxia/hypercapnia, melanocortin receptor accessory protein 2, and glucagon. Literature reports show that Hcrt/orexin can significantly increase insulin secretion from normal and diabetic rat pancreata. Hcrt/orexin decreases blood glucose concentration and reduces insulin resistance partly via increased tissue expression of glucose transporter type 4. It reduces obesity by increasing browning of fat cells and energy expenditure. Taken together, Hcrt/orexin modulates obesity and the metabolism of glucose and insulin. The Hcrt/orexin system may thus be a target in the development of new therapies for the treatment of diabetes mellitus.     

Elastic modulus and flexural strength comparisons of high-impact and traditional denture base acrylic resins

Background

Fractures of acrylic resin dentures are a common occurrence in clinical dentistry. The denture may be fractured accidentally when dropped or while in service in the mouth due to flexural fatigue.

Objectives

The aim of this study was to compare the elastic modulus and the flexural strength between two heat-cured acrylic resins used in denture bases: a high-impact resin (Lucitone 199) and a traditional resin (Rodex).

Materials and methods

Rectangular strips of Lucitone 199 and Rodex (10 samples each) were fabricated and stored in artificial saliva at 37 °C for 2 weeks. The specimens were subjected to a three-point flexural test. The data were statistically analysed with Student’s t-test (p ⩽ .05).

Results

The high-impact acrylic resin had a lower elastic modulus (p = .000) and higher flexural strength (p = .001) compared to the traditional acrylic resin.

Conclusion

Within the limitations of this study, it can be concluded that the high-impact acrylic resin is a suitable denture base material for patients with clinical fracture of the acrylic denture.     

Predictive value and reference ranges of anogenital distance for determining fetal gender in the first trimester: A retrospective cohort study

Objectives:To assess the usefulness of sonographically measured anogenital distance (AGD) in predicting fetal gender in Saudi fetuses during the first trimester and to provide normal reference centiles for AGD.Methods:A retrospective cohort study was conducted at King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia between November 2020 and May 2021. The ultrasound scans of 313 singleton pregnancies between 11–13 plus 6 gestational weeks and their gender-at-birth were collected. Anogenital distance was measured from the inferior base of the genital tubercle to the rump. Binominal logistic regression and receiver operating characteristic curves (ROC) evaluated the predictive performance of AGD for determining fetal gender.Results:There was a significant difference of approximately 15% in mean AGD between female (5.92 mm [95% CI= 6.70, 6.14]) and male (6.80 mm [95% CI= 6.61,7.00]) fetuses (p<0.001). Anogenital distance significantly correlated with gestational age (r=0.573, p<0.001) and crown-rump length (r=0.562, p<0.001). The logistic regression determined AGD as a significant predictor of fetal gender (p<0.001). However, ROC analysis showed that overall accuracies were low at 68% (p=0.001) for 11 weeks, 70% (p<0.001) for 12 weeks, and 64% (p=0.017), and for 13 weeks. The average AGD of our Saudi cohort was longer than what the literature reported from other populations.Conclusion:The first-trimester ultrasound evaluation of AGD was feasible and reliable. It showed a difference between the genders but did not yield high predictive accuracy. Future research should consider racial factors when evaluating AGD.     

Thoracoscopic division of vascular rings in infants and children

Objective

Traditionally vascular rings in infants and children are treated through an open thoracotomy. Recently, thoracoscopic surgery has been used for these complex procedures. This study reports our early experience with thoracoscopic division of vascular rings and evaluates the efficacy and safety of this approach.

Material and Methods

Patients who underwent thoracoscopic division of vascular rings at King Khalid University Hospital, Riyadh, Saudi Arabia, from December 2004 to January 2006 are included. Their data were carefully analyzed looking at demographics, clinical presentation, diagnostic modality, type of the anomaly, operative details, complications, and outcome.

Results

A total of 9 patients underwent thoracoscopic division of vascular rings. Age at surgery ranged between 2 and 108 months (mean, 24 months). Weight varied between 5.3 and 32 kg (mean, 10.3 kg). All patients were symptomatic. Computed tomographic scan was diagnostic and accurately defined the type of anomaly in all the patients. Four patients had a right aortic arch with an aberrant left subclavian artery and left ductus/ligamentum arteriosum, 2 had double aortic arches, and 3 had a right aberrant subclavian artery. One patient developed right-sided pneumothorax on the contralateral site, and another one developed apnea 12 hours after surgery, requiring mechanical ventilation. There was no mortality. Operative time ranged between 50 and 145 minutes, the mean being 107 minutes. The average hospital stay was 4 days. Five patients had their preoperative symptoms completely resolved, and the rest are showing steady improvement. The average follow-up period is 6 months.

Conclusion

Our early experience indicates that thoracoscopic division of vascular rings is safe and effective. Because it takes away the need for thoracotomy, it is likely that it can result in less postoperative pain and rapid convalescence. It also prevents the ill effects of thoracotomy and gives good cosmetic results.     

Epidemiology of 11 respiratory RNA viruses in a cohort of hospitalized children in Riyadh,Saudi Arabia

Respiratory tract infections are a principal cause of illness and mortality in children worldwide and mostly caused by viruses. In this study, the epidemiology of 11 respiratory RNA viruses was investigated in a cohort of hospitalized children at a tertiary referral center in Riyadh from February 2008 to March 2009 using conventional and real‐time monoplex RT‐PCR assays. Among 174 nasopharyngeal aspirates, respiratory syncytial virus (RSV) was detected in 39 samples (22.41%), influenza A virus in 34 (19.54%), metapneumovirus (MPV) in 19 (10.92%), coronaviruses in 14 (8.05%), and parainfluenza viruses (PIVs) in 11 (6.32%). RSV, PIVs and coronaviruses were most prevalent in infants less than 6 months old, whereas MPV and influenza A virus were more prominent in children aged 7–24 and 25–60 months, respectively. The majority of the viruses were identified during winter with two peaks observed in March 2008 and January 2009. The presented data warrants further investigation to understand the epidemiology of respiratory viruses in Saudi Arabia on spatial and temporal basis. J. Med. Virol. 88:1086–1091, 2016 . © 2015 Wiley Periodicals, Inc.

     

Experimentally designed chromatographic method for the simultaneous analysis of dimenhydrinate,cinnarizine and their toxic impurities

Recently, experimental design has beaten the traditional optimization approach (one variable at a time) by providing better quality for chromatographic separation using minimal effort and resources. Benzophenone (BZP) and [1-(diphenylmethyl)piperazine] (DPP) were reported to be the most toxic impurities for dimenhydrinate (DMH) and cinnarizine (CIN), respectively. Additionally, there is no reported HPLC method for the simultaneous determination of DMH, CIN and their toxic impurities. A custom experimental design was adopted to estimate the optimum conditions that achieved the most acceptable resolution with adequate peak symmetry within the shortest run time. Desirability function was used to define the optimum chromatographic conditions and the optimum separation was achieved using XBridge® HPLC RP-C18 (4.6 × 250 mm, 5 μm), acetonitrile: 0.1% sodium lauryl sulphate (SLS) in water (90 : 10, v/v) as a mobile phase at flow rate 2 mL min⁻¹ and UV detection at 215 nm. Method validation was carried out according to ICH guidelines and linearity was achieved in the ranges of 2–25, 1–25, 1–12.5, and 1–12.5 μg mL⁻¹ for DMH, CIN, BZP and DPP, respectively. By application of the proposed method to the market dosage form, no interference from excipients was observed. Moreover, the greenness of the method was evaluated using the National Environmental Method Index (NEMI), Analytical Eco-Scale and Green Analytical Procedure Index (GAPI) metrics and the results revealed the green environmental impact of the developed method.

Experimentally designed HPLC method for simultaneous analysis of dimenhydrinate, cinnarizine and their toxic impurities.     

Immune checkpoint inhibitor-induced colitis:A comprehensive review

Immune checkpoint inhibitors(ICIs) are monoclonal antibodies that target downregulators of the anti-cancer immune response: Cytotoxic T-lymphocyte antigen-4, programmed cell death protein-1, and its ligand programmed death-ligand 1.ICIs have revolutionized the treatment of a variety of malignancies. However,many immune-related adverse events have also been described which mainly occurs as the immune system becomes less suppressed, affecting various organs including the gastrointestinal tract and causing diarrhea and colitis. The incidence of immune-mediated colitis(IMC) ranges from 1%-25% depending on the type of ICI and if used in combination. Endoscopically and histologically there is a significant overlap between IMC and inflammatory bowel disease,however more neutrophilic inflammation without chronic inflammation is usually present in IMC. Corticosteroids are recommended for grade 2 or more severe colitis while holding the immunotherapy. About one third to two thirds of patients are steroid refractory and benefit from infliximab. Recently vedolizumab has been found to be efficacious in steroid and infliximab refractory cases. While in grade 4 colitis, the immunotherapy is permanently discontinued, the decision is controversial in grade 3 colitis.