Retinol-binding protein 4 levels are elevated in polycystic ovary syndrome women with obesity and impaired glucose metabolism

OBJECTIVE: Insulin resistance and obesity are common features of the polycystic ovary syndrome (PCOS). Retinol-binding protein 4 (RBP4), a new fat-derived adipokine, has been described to be elevated in obesity and type 2 diabetes. The aim of the present study was to investigate whether serum RBP4 levels are correlated with metabolic parameters, indices of insulin resistance, and endocrine variables in German PCOS women. DESIGN: We assessed the correlation between metabolic and endocrine parameters with RBP4 levels in 200 PCOS patients and 64 healthy controls. METHODS: Serum RBP4 was measured by enzyme-linked immunosorbent assay (Immundiagnostik AG, Bensheim, Germany). In addition, anthropometric variables, clinical signs of hyperandrogenism, and body fat were evaluated, and a glucose tolerance test was performed to assess parameters of insulin resistance and glucose metabolism. RESULTS: Taking the entire PCOS cohort, RBP4 levels were positively correlated with body mass index (BMI), body fat, waist circumference, fasting glucose, and area under the curve for glucose (all P<0.05), but not with indices of insulin resistance. On the other hand, PCOS women with impaired glucose metabolism had higher RBP4 levels than PCOS women with normal glucose metabolism (median 30.6, range 23.3-73.9 versus median 26.3, range 6.4-61.4, P<0.05). Furthermore, no differences were found in RBP4 levels between lean PCOS women and BMI-matched healthy controls. CONCLUSION: In German PCOS women, serum RBP4 levels are associated with obesity and parameters of glucose metabolism but not with PCOS per se.     

Asymmetric dimethylarginine determines the improvement of endothelium-dependent vasodilation by simvastatin: Effect of combination with oral L-arginine.

OBJECTIVES: We hypothesized that the level of asymmetric dimethylarginine (ADMA), an endogenous inhibitor of endothelial nitric oxide (NO) synthase (eNOS), might determine the endothelial effects of statins. BACKGROUND: Endothelial NO synthase is up-regulated by statins. However, statins failed to improve endothelial function in some studies. Asymmetric dimethylarginine inhibits eNOS by a mechanism that is reversible by L-arginine. METHODS: Ninety-eight clinically asymptomatic elderly subjects had their plasma ADMA levels screened. Those in the highest (high ADMA, n = 15) and lowest quartiles of the ADMA distribution (low ADMA, n = 13) were eligible to receive, in a randomized order, simvastatin (40 mg/day), L-arginine (3 g/day), or a combination of both, each for 3 weeks. Endothelium-dependent vasodilation (EDD) was assessed by brachial artery ultrasound. RESULTS: Simvastatin had no effect on EDD in subjects with high ADMA (6.2 +/- 1.2% vs. 6.1 +/- 0.9%), whereas simvastatin plus L-arginine significantly improved EDD (9.8 +/- 1.5% vs. 5.3 +/- 0.8%; p < 0.01). In subjects with low ADMA, simvastatin improved endothelial function when given alone (9.5 +/- 3.2% vs. 6.1 +/- 3.8%; p < 0.001) or in combination with L-arginine (9.0 +/- 3.1% vs. 6.3 +/- 3.3%; p = 0.001). L-arginine alone improved endothelial function in both groups. Endothelium-independent vasodilation was not affected. CONCLUSIONS: Simvastatin does not enhance endothelial function in subjects with elevated ADMA, whereas it does so in patients with low ADMA. Combination of simvastatin with oral L-arginine improves endothelial function in subjects with high ADMA, but has no additional effect in subjects with low ADMA. As NO-mediated effects may play a major role in the therapeutic effects of statins, ADMA concentration is an important factor that influences the "pleiotropic" effects of simvastatin.     

Transgastric pancreatography and EUS-guided drainage of the pancreatic duct

Background/Purpose

Endoscopic transpapillary drainage of the retained pancreatic duct in symptomatic patients with chronic pancreatitis is considered an established treatment option. The aim of this study was to investigate, as an alternative, endoscopic ultrasound (EUS)-guided transgastric pancreatography and drainage of the pancreatic duct, in terms of their feasibility and outcome.

Methods

All consecutive symptomatic patients with failure of the traditional approach to catheterize and drain the pancreatic duct, over a 3-year time period, were enrolled in this prospective, observational single-center study (case series). Feasibility was characterized by success rate, outcome by complication rate (frequency of bleeding or perforation), mortality, and follow-up.

Results

Twelve patients underwent 14 interventions (sex ratio, M/F, 10?:?4; age range, 43–77 years) from November 2002 to October 2005. The main indication was retention of the pancreatic duct associated with pain, in particular: (i) papilla not reachable because of prior gastrointestinal surgery (n = 5); and (ii) not possible to introduce the catheter through the papilla in chronic pancreatitis or “pancreas divisum” (n = 7). Pancreatography was successful in all patients (normal finding with no therapeutic consequence, n = 1 [after pancreaticojejunostomy]), whereas drainage of the pancreatic duct was achieved in 9 patients (69%; attempts, n = 13). The transgastric route was used in 5 patients and the transpapillary route (rendezvous technique with endoscopic retrograde cholangiopancreatography [ERCP]) in 4. There was a complication rate of 42.9%, comprising postinterventional pain (n = 4; 28.6%); bleeding (n = 1); and perforation because of retriever problems (n = 1). The postinterventional pancreatitis rate was 0% and mortality was 0%. The follow-up investigation (range, 4 weeks ? 3 years) revealed that 4 patients (28.6%) subsequently underwent surgical intervention, because of duodenal stenosis (n = 1; 7.1%), suspicious tumor growth (n = 1; 7.1%), and insufficient drainage of the pancreatic duct (n = 2; 14.3%). In 2 subjects (14.3%), endoscopic reinterventions became necessary, which were subsequently successful. There were the following technical problems: 1) Too dense stenosis (n = 3); 2) inadequate equipment (insufficient infeed of the endoscopic tool because of its bending), in each case.

Conclusions

Transgastric pancreatography and EUS-guided drainage of the pancreatic duct are reasonable and feasible alternative options for diagnostic and therapeutic management for selected indications (chronic pancreatitis; anomaly of the congenital pancreatic or postoperative gastrointestinal anatomy), with an acceptable periinterventional risk, which broaden the therapeutic spectrum and may avoid surgery but need further evaluation and follow-up investigation.

     

5-HTT binding in recovered depressed patients and healthy volunteers: a positron emission tomography study with [11C]DASB

OBJECTIVE: The serotonin transporter (5-HTT) is a key target for selective serotonin reuptake inhibitors and may be involved in the pathophysiology of major depression. It is now possible to image 5-HTT directly in the human brain, but results from studies of acutely depressed patients have been inconsistent. The purpose of this study was to determine whether abnormalities in 5-HTT might be present in recovered depressed patients. METHOD: The authors measured the binding potential of 5-HTT using [11C]DASB in conjunction with positron emission tomography (PET) in 24 medication-free, recovered depressed male patients and 20 healthy male comparison subjects. The regional estimates of binding potential were obtained using a metabolite-corrected plasma input function method followed by Logan analysis, with the cerebellum as a reference region. RESULTS: The authors found no significant difference in the binding potential of [11C]DASB between the recovered depressed patients and healthy comparison subjects in any of the brain regions (amygdala, anterior cingulate cortex, caudate nucleus, frontal cortex, hippocampus, insula, thalamus, and dorsal raphe) studied. CONCLUSIONS: Men who recover from depression have normal availability of 5-HTT in brain regions thought to be involved in the pathophysiology of depression. The findings therefore do not support the proposal that recurrent depression is associated with long-standing deficits in 5-HTT.     

Contrast-dose relation in first-pass myocardial MR perfusion imaging

PURPOSE: To determine the regime of linear contrast enhancement in human first-pass perfusion cardiovascular magnetic resonance (CMR) imaging to improve accuracy in myocardial perfusion quantification. MATERIALS AND METHODS: A total of 10 healthy subjects were studied on a clinical 1.5T MR scanner. Seven doses of Gd-DTPA ranging from 0.00125 to 0.1 mmol/kg of body weight (b.w.) were administered as equal volumes by rapid bolus injection (6 mL/second). Resting periods of 15 minutes were introduced after delivery of Gd doses >0.01 mmol/kg b.w. For each subject, two series of rest perfusion scans were performed using two different multislice saturation-recovery perfusion sequences. Maximum contrast enhancement and maximum upslope were obtained in the blood pool of the left ventricular (LV) cavity and in the myocardium. The range of linear contrast-dose relation was determined by linear regression analysis. RESULTS: MR signal intensity increased linearly for contrast agent concentrations up to 0.01 mmol/kg b.w. in the LV blood pool and up to 0.05 mmol/kg b.w. in the myocardium. For Gd concentrations exceeding these thresholds the signal intensity response was not linear with respect to the contrast agent dose. CONCLUSION: Quantitative evaluation of cardiac MR perfusion data needs to account for signal saturation in both the LV blood pool and the myocardium.     

Economic image compression of output documentation of the most frequent examinations in nuclear medicine

RATIONALE AND OBJECTIVES: In recent years, picture archiving and communication systems and electronic transfer of radiologic images using the digital imaging and communications in medicine file standard has become more widely employed in diagnostic radiology. It seems to be likely that nuclear medicine will be integrated within such systems. On the other hand, many departments possess older nuclear medicine equipment without digital output facilities. There is an increasing tendency to display and archive evaluated images ("save-screens," printouts) on nondedicated, inexpensive systems using file formats capable of data compression. This was the reason for examining the value of the JPEG format in this pilot study. MATERIALS AND METHODS: Fifty scanned planar bitmap images of the most frequent scintigraphic examinations (thyroid, bone, myocardium, lungs, and kidneys) were compared with JPEG format at different data compressions by two blinded observers. The visualization of details (eg, pathologic findings) is described for all these images as the visual appearance of the images and the storage capacity required. RESULTS: Relevant loss of clinical information did not occur up to compression factors of 0.75. A major decrease of subjective image quality was seen at compression factors >0.90. Compared with bitmap files, the use of these factors reduced the storage capacity required by 98% at a (JPEG-related) compression factor of 0.50, and 99% at a compression factor of 0.90. Compared with the GIF format, a reduction by 4.0-5.7 could be achieved. CONCLUSIONS: Use of the JPEG format can therefore be recommended to save costs of image transfer or archiving of standard planar scans for nuclear medical evaluation.