Hypoglycemic effects of steroidal sapogenins isolated from Jamaican bitter yam, Dioscorea polygonoides.

In this study, three steroidal sapogenins (Delta3 diosgenin, diosgenin, and pennogenin) and the phytosterols, stigmasterol and beta-sitosterol were isolated from Jamaican bitter yam, Dioscorea polygonoides. Their effects on fasting blood glucose and intestinal amylase and ATPases in streptozotocin-induced diabetic rats were studied. The diabetic rats (fed supplemented and unsupplemented diets) lost weight significantly compared to the normal group. There was a significant increase in the activity of alpha-amylase in the proximal region of the small intestinal mucosa of diabetic rats fed sapogenin extract or commercial diosgenin. However, this did not result in increased fasting blood glucose. Instead, supplementation of the diet with bitter yam sapogenin extract significantly decreased fasting blood glucose compared to the diabetic group. Supplementation of the diet with bitter yam sapogenin extract or commercial diosgenin significantly reduced Na+-K+-ATPase activity in all three regions compared to the diabetic control group. Commercial diosgenin supplementation resulted in a significant increase in Ca2+ ATPase activity in proximal region compared to the diabetic control and bitter yam sapogenin extract groups. The effect of bitter yam sapogenin extract or commercial diosgenin on intestinal Na+-K+-ATPase activity could account for their hypoglycemic properties. However, there was adverse effect on the body weight.     

Homocysteine and nitrite levels are modulated by MTHFR 677C>T polymorphism in obese women treated with simvastatin

Higher homocysteine (Hcy) levels are associated with cardiovascular risk. The aim of the present study was to evaluate the effect of simvastatin treatment on circulating Hcy levels in obese women without hypertension, diabetes or dyslipidaemia; and to determine whether the 677C>T polymorphism located in methylenetetrahydrofolate reductase (NAD(P)H) (MTHFR) gene modulates the effects of this treatment on Hcy and nitrite (as a biomarker of nitric oxide (NO) bioavailability). Twenty‐five obese women (body mass index ≥ 30 kg/m²) who had received 20 mg/day simvastatin for 6 weeks were enrolled in the study. Venous blood samples were collected to measure plasma biomarkers and gene polymorphisms. Simvastatin treatment significantly reduced total cholesterol, low‐density lipoprotein–cholesterol, thiobarbituric acid‐reactive substances, high‐sensitivity C‐reactive protein and Hcy, whereas nitrite levels were increased. The reduction in Hcy levels in carriers of the T allele was ?20.3% compared with –9.4% in patients with the CC genotype. Importantly, before treatment, nitrite levels were significantly higher in patients with the CC genotype compared with T allele carriers, whereas after treatment these levels were similar between groups. Our findings demonstrate that obese women without comorbidities and carrying the T variant of the 677C>T polymorphism of MTHFR exhibit benefits with simvastatin treatment, mainly in terms of increased NO levels.     

Canthaxanthin induces apoptosis in human cancer cell lines

To investigate the possibility that canthaxanthin inhibits cancer cell growth by inducing apoptosis, human WiDr colon adenocarcinoma and SK- MEL-2 melanoma cells were treated with two different doses of the carotenoid for 48 h. Canthaxanthin was incorporated and/or associated to cells. The treatment with the carotenoid caused growth inhibition in both cell types. Concomitantly, apoptosis was induced. Increasing time of exposure and carotenoid concentration, this effect was more pronounced. At 48 h, the percentages of apoptotic cells were 13 and 15, using 1 microM canthaxanthin, and 18 and 20, using 10 microM canthaxanthin in WiDr and SK-MEL-2 cells, respectively. This study represents the first demonstration that canthaxanthin is able to induce apoptosis in tumour cells.      

Hemoglobin A1c: Assessment of three POC analyzers relative to a central laboratory method

BackgroundGlycosylated hemoglobin evaluation is very important for assessing the control of diabetes. Since the use of point-of-care (POC) devices for monitoring HbA1c is increasing, it is important to determine how these devices compare in relation to instrumentation used in the central laboratory (CL).MethodsEighty-eight randomly selected samples previously analyzed using the Bio-Rad Variant? II Hemoglobin Testing System were run on three POC Analyzers (Siemens DCA Vantage? Analyzer, Axis-Shield Afinion? AS100 Analyzer, and Bio-Rad In2it? Analyzer).ResultsAll POC instruments showed good correlation to the CL method (R² > 0.95 for all methods). HbA1c levels obtained using Variant II (mean = 7.9; 95% CI = 7.5–8.3%) and In2it (mean = 7.9; 95% C.I. = 7.5–8.2%) instruments were found to have no statistical mean difference (p = 0.21), while the values obtained using DCA Vantage (mean = 7.2% C.I. = 6.9–7.5%) and Afinion (mean = 7.3% C.I. = 7.0–7.6%) instruments were different (p < 0.001) from those of the CL method. The Afinion and DCA Vantage instruments increasingly underestimated the HbA1c compared to the CL as the HbA1c values increased. These differences were even more striking when the estimated average glucose is calculated.ConclusionsDespite significant variation of results among the POC instruments evaluated relative to the CL method and pending resolution of HbA1c standardization issues, we conclude that all of the POC instruments can be used for HbA1c determination if clinicians are given instrument specific reference ranges.     

Normal and stenotic renal arteries: experimental balloon-expandable intraluminal stenting

Elastic recoil of the vessel wall is a common cause of failure of percutaneous transluminal angioplasty in renal arteries. To oppose such recoil, balloon-expandable metal stents were implanted in artificially stenotic renal arteries in pigs and normal renal arteries in dogs and pigs. The stents were then examined angiographically and histologically at regular intervals. All stents were completely covered with endothelialized neointima in 3 weeks. There was no difference in intimal thickness between the stenotic and nonstenotic renal arteries. A large stent diameter and a large open or nonmetal surface may cause less intimal hyperplasia, but nonturbulent, fast arterial flow is probably the most important factor in ensuring long-term patency of the vessel.     

Are Incoming Pediatric Interns Ready to Obtain the Essential Components of an Informed Consent for Lumbar Puncture?

ObjectiveIn 2013, the Association of American Medical Colleges created the “Core Entrustable Professional Activities (EPAs) for Entering Residency” to more clearly define the set of activities that entering residents should be able to perform on day 1 of residency without direct supervision. EPA #11 is obtaining informed consent for tests and/or procedures. This EPA acknowledges that an entrustable learner should be able to document a complete consent among other components. The aim of this study is to explore whether incoming pediatric interns demonstrated the behaviors of an “entrustable learner” in the domain of documenting informed consent for a common pediatric procedure.MethodsAll incoming interns in our program (2007–2017) completed a 6-station Objective Structured Clinical Examination during residency orientation. One of the scenarios involves obtaining parental consent for a lumbar puncture (LP). The researchers determined and agreed what components would be important for a complete and accurately documented consent. A retrospective review of the resident's written informed consents occurred looking for accuracy of documented components.ResultsOf the 258 consents reviewed, 8 were complete and accurate. Incoming interns appear to be skilled when completing the basics of the informed consent form such as documenting names, obtaining signatures, and correctly identifying the procedure. However, detailing all the risks of the LP were areas for which they did not demonstrate proficiency.ConclusionsDocumenting informed consent is not adequately demonstrated by our learners prior to the beginning of internship. We would recommend specific training before entrusting pediatric interns to obtain LP consent independently.     

Pharmacokinetics of biliary excretion of N-nitrosodimethylamine in rats fed diets containing levels of protein

Albino Wistar rats (Rattus norvegius) fed semi-purified diets containing 3.5%, 8%, 27%, and 64% casein, respectively, as the protein source, were poisoned with an intraperitoneal dose of 20mg N-nitrosodimethylamine (NDMA)/kg, following cannulation of the bile duct, in vitro, under urethane anaesthesia. Bile exudates was collected at designated time intervals and analysed for unchanged NDMA using thin layer chromatography and gas liquid chromatography methods. Rats on 64% high protein diet (HPD) were the highest excretors of NDMA, followed by rats on the 3.5% kwashiorkorigenic diet (KWD), 8% low protein diet (LPD) and 27% normal protein diet (NDP) as the least excretors, in that order. The corresponding values for culmulative excretions of NDMA were 4.38%, 2.74%, 2.96% and 4.11%, and for elimination rate contents they were 54.05Kh⁻¹, 23.01Kh⁻¹, 23.76Kh⁻¹ and 48.88Kh⁻¹, while the respective elimination half-life values were 0.013h, 0.031h, 0.029h and 0.014h. The toxicological and pharmacological implication of the pharmacokinetic findings are discussed.