<Emphasis Type="Italic">Labisia pumila</Emphasis> extract down-regulates hydroxysteroid (11-beta) dehydrogenase 1 expression and corticosterone levels in ovariectomized rats

We evaluated the effects of a standardized Labisia pumila var. alata (LPva) extract on body weight change, hydroxysteroid (11-beta) dehydrogenase 1 (HSD11B1) expressions and corticosterone (CORT) level in ovariectomized (OVX) rats. The decoction of LPva has been used for generations among Malay women in Malaysia to maintain a healthy reproductive system.Thirty-six Sprague–Dawley OVX rats were treated orally with LPva extract (10, 20 or 50 mg/kg/day) or estrogen replacement (ERT) for 30 days. Sham operated rats were used as controls. Compared to untreated OVX rats, LPva-treated rats showed less weight gain and had significantly down-regulated HSD11B1 mRNA in liver tissues. HSD11B1 mRNA in adipose tissues increased by 55% (p < 0.05) in OVX rats but normalized in rats treated with LPva. Similarly, there was significant down-regulation (p < 0.05) of protein levels of HSD11B1 in both liver and adipose tissue of LPva and ERT groups, and CORT levels were significantly reduced in both groups of rats. This is the first study ever conducted to evaluate the beneficial effects of LPva in relation to weight gain caused by estrogen insufficiency. Results implied that the bioactive components in LPva extract affect not only HSD11B1 expressions in both adipose and liver tissues but also decrease circulating CORT. The extract should be explored for its potential use as a natural remedy for weight management.     

Atherosclerotic plaques in the internal carotid artery and associations with lung function assessed by different methods

Background: Previous studies on associations between reduced lung function and cardiovascular disease (CVD) have mainly been based on forced expiratory volume in 1‐s (FEV₁) and vital capacity (VC). This study examined potential associations between five different lung function variables and plaques in the internal carotid artery (ICA). Methods: Subjects (n = 450) from a previous population‐based respiratory questionnaire survey [current smokers without lower respiratory symptoms, subjects with a self‐reported diagnosis of chronic obstructive pulmonary disease (COPD) and never‐smokers without lower respiratory symptoms] were examined using spirometry, body plethysmography and measurements of diffusing capacity for CO (D_L,CO). Plaques in the ICA were assessed by ultrasonography. Results: Two hundred and twenty subjects were current smokers, 139 ex‐smokers and 89 never‐smokers. COPD was diagnosed in 130 subjects (GOLD criteria). Plaques in the ICA were present in 231 subjects (52%). General linear analysis with adjustment for established risk factors for atherosclerosis, including C‐reactive protein, showed that D_L,CO was lower [77·4% versus 83·7% of predicted normal (PN), P = 0·014] and residual volume (RV) was higher (110·3% versus 104·8% of PN, P = 0·020) in subjects with than without plaques in the ICA. This analysis did not show any statistically significant association between plaques and FEV₁ or VC. Conclusion: The occurrence of plaques in the ICA was associated with low D_L,CO and high RV, but not significantly with FEV₁ or COPD status. The results suggest that the relationships between reduced lung function, COPD and CVD are complex and not only linked to bronchial obstruction and low‐grade systemic inflammation.     

Increased expression of adenylyl cyclase 3 in pancreatic islets and central nervous system of diabetic Goto-Kakizaki rats: A possible regulatory role in glucose homeostasis

Adenylyl cyclase 3 (AC3) is expressed in pancreatic islets of the Goto-Kakizaki (GK) rat, a spontaneous animal model of type 2 diabetes (T2D), and also exerts genetic effects on the regulation of body weight in man. In addition to pancreatic islets, the central nervous system (CNS) plays an important role in the pathogenesis of T2D and obesity by regulating feeding behavior, body weight and glucose metabolism. In the present study, we have investigated AC3 expression in pancreatic islets, striatum and hypothalamus of GK rats to evaluate its role in the regulation of glucose homeostasis. GK and Wistar rats at the age of 2.5 mo were used. A group of GK rats were implanted with sustained insulin release chips for 15 d. Plasma glucose and serum insulin levels were measured. AC3 gene expression levels in pancreatic islets, striatum and hypothalamus were determined by using real-time RT-PCR. Results indicated that plasma glucose levels in Wistar rats were found to be similar to insulin-treated GK rats, and significantly lower compared with non-treated GK rats. AC3 expression levels in pancreatic islets, striatum and hypothalamus of GK rats were higher compared with Wistar rats, while the levels were intermediate in insulin-treated GK rats. The AC3 expression display patterns between pancreatic islets and striatum-hypothalamus were similar. The present study thus provides the first evidence that AC3 is overexpressed in the regions of striatum and hypothalamus of brain, and similarly in pancreatic islets of GK rats suggesting that AC3 plays a role in regulation of glucose homeostasis via CNS and insulin secretion.     

Standing radiographs underestimate joint widthComparison before and after resection of the joint in 34 total knee arthroplasties

Background?Measurement or estimation of joint width is routinely used in the preoperative evaluation of gonarthrosis. To our knowledge, the validity and reproducibility of this procedure has not been adequately studied.Patients and methods?We measured joint width in 34 knees (medial arthrosis: n?=?22, lateral arthrosis: n?=?12) on preoperative weight-bearing radiographs and on radiographs of the corresponding part of the joint after knee arthroplasty. The bone/cartilage pieces were placed in anatomical positions and loaded in a jig made of perspex. High-density film was used to obtain maximum resolution.Results?In medial and lateral arthrosis, the minimum joint widths were median 0.3 and 0.2?mm smaller on the radiographs of the specimens (p?=?0.05, 0.04). In lateral arthrosis the differences were more scattered (95% CI: lateral: 0.1 to ?1.2?mm; medial: 0 to ?0.5?mm), suggesting less precise determination.Interpretation?In medial arthrosis, the degree of underestimation is usually small and acceptable. More pronounced discrepancies could be found in lateral arthrosis, calling for the use of further diagnostic measures.     

Serum 25-hydroxyvitamin D concentration, established and emerging cardiovascular risk factors and risk of myocardial infarction before the age of 60 years

ObjectiveWe examined the relationships of serum 25-hydroxyvitamin D (25(OH)D) concentration to established and emerging cardiovascular risk factors and risk of myocardial infarction (MI) in a population-based case–control study of MI before the age of 60 years.MethodsA total of 387 survivors of a first MI and 387 sex- and age-matched controls were included. Fasting blood samples drawn three months after the MI in cases and at the same time in the matched controls were used for biochemical analyses.ResultsSerum concentrations of 25(OH)D, adjusted for seasonal variation, were lower in cases than controls (55.0 (40.0–71.0) nmol/L vs 60.5 (47.0–75.0) nmol/L; median (interquartile range); standardized odds ratio (OR) for MI with 95% confidence interval in univariable analysis: 0.80 (0.69–0.93); p = 0.003). The 25(OH)D association with MI disappeared after adjustment for established and emerging risk factors (OR: 1.01 (0.82–1.25)). Current smoking and plasma levels of proinsulin and PAI-1 activity were independently associated with 25(OH)D in controls, whereas waist circumference, plasma triglycerides, proinsulin, PAI-1 activity and cystatin C, and non-Nordic ethnicity were independently associated with 25(OH)D in patients. Serial measurements of 25(OH)D (samples drawn <4 h and 3 months after the onset of MI) in 57 patients showed no systematic differences between sampling times.ConclusionVitamin D insufficiency, which is associated with a multitude of metabolic, procoagulant and inflammatory perturbations, is not independently related to premature MI. This suggests that vitamin D insufficiency either constitutes an epiphenomenon or increases the risk of MI by promoting established risk factor mechanisms that predispose to atherothrombosis.     

Postprandial platelet activation is related to postprandial plasma insulin rather than glucose in patients with type 2 diabetes

Postprandial hyperglycemia is associated with platelet activation. We thus investigated if meal-induced platelet activation could be attenuated by meal insulin. A randomized, double-blind, cross-over study was performed to compare postprandial platelet activation after premeal injections of placebo or insulin aspart (0.1 and 0.2 units/kg) in 18 patients with type 2 diabetes mellitus (T2DM). Platelet activation was assessed by flow cytometry, without and with stimulation by the thromboxane analog U46619 or ADP. Measurements were before and after premeal blood glucose standardization (to 6-7 mmol/L by insulin infusion, if needed) and at 90 min after the meal. Premeal insulin reduced postprandial hyperglycemia by 2-3 mmol/L compared with placebo. Postmeal insulin levels were doubled with placebo and further elevated with insulin injections. The standardized meal enhanced U46619-induced platelet P-selectin expression by 23% after placebo; this response was more than doubled after premeal insulin. U46619-induced fibrinogen binding was unchanged after meal intake with placebo but was markedly enhanced (by ～50-60%) after premeal insulin. Postprandial platelet activation correlated positively to postprandial insulin levels and inversely to glucose levels. Premeal insulin infusion was also associated with platelet activation. Our results suggest that postprandial insulin rather than glucose accounts for postprandial platelet activation in T2DM patients.     

Pedagogical strategies used in clinical medical education: an observational study

Background  

Clinical teaching is a complex learning situation influenced by the learning content, the setting and the participants' actions and interactions. Few empirical studies have been conducted in order to explore how clinical supervision is carried out in authentic situations. In this study we explore how clinical teaching is carried out in a clinical environment with medical students.