Regulation of pancreatic islet gene expression in mouse islets by pregnancy

Pancreatic β cells adapt to pregnancy-induced insulin resistance by unclear mechanisms. This study sought to identify genes involved in β cell adaptation during pregnancy. To examine changes in global RNA expression during pregnancy, murine islets were isolated at a time point of increased β cell proliferation (E13.5), and RNA levels were determined by two different assays (global gene expression array and G-protein-coupled receptor (GPCR) array). Follow-up studies confirmed the findings for select genes. Differential expression of 110 genes was identified and follow-up studies confirmed the changes in select genes at both the RNA and protein level. Surfactant protein D (SP-D) mRNA and protein levels exhibited large increases, which were confirmed in murine islets. Cytokine-induced expression of SP-D in islets was also demonstrated, suggesting a possible role as an anti-inflammatory molecule. Complementing these studies, an expression array was performed to define pregnancy-induced changes in expression of GPCRs that are known to impact islet cell function and proliferation. This assay, the results of which were confirmed using real-time reverse transcription-PCR assays, demonstrated that free fatty acid receptor 2 and cholecystokinin receptor A mRNA levels were increased at E13.5. This study has identified multiple novel targets that may be important for the adaptation of islets to pregnancy.

Assessing sources of inconsistencies in genotypes and their effects on genome-wide association studies with HapMap samples

The discordance in results of independent genome-wide association studies (GWAS) indicates the potential for Type I and Type II errors. We assessed the repeatibility of current Affymetrix technologies that support GWAS. Reasonable reproducibility was observed for both raw intensity and the genotypes/copy number variants. We also assessed consistencies between different SNP arrays and between genotype calling algorithms. We observed that the inconsistency in genotypes was generally small at the specimen level. To further examine whether the differences from genotyping and genotype calling are possible sources of variation in GWAS results, an association analysis was applied to compare the associated SNPs. We observed that the inconsistency in genotypes not only propagated to the association analysis, but was amplified in the associated SNPs. Our studies show that inconsistencies between SNP arrays and between genotype calling algorithms are potential sources for the lack of reproducibility in GWAS results.

Callosal lesion predicts future attacks after clinically isolated syndrome

BACKGROUND

Current MRI criteria can help predict a second attack after a clinically isolated syndrome (CIS). Given the known association between corpus callosum lesions (CC) and multiple sclerosis (MS), such lesions on MRI could provide additional predictive information. This study assessed whether the presence of CC lesion on MRI could, next to the modified Barkhof criteria, further enhance prediction of conversion from CIS to MS.

METHODS

Follow-up study of 158 patients with CIS who underwent MRI after CIS was performed. MRI were scored for the Barkhof criteria and CC lesion. Patients were classified as having MS according to Poser criteria. Cox regression models were used for the time to conversion from CIS to MS.

RESULTS

The Barkhof criteria and CC lesion were strongly associated with conversion to MS with hazard ratios (HR), respectively, of 2.6 (95% confidence interval [CI] 1.5-4.3) and 2.7 (95% CI 1.6-4.5). The HRs of CC lesion adjusted for the Barkhof criteria and the Barkhof criteria adjusted for CC lesion were similar (HRs 1.8, not significant). The combined prediction of the Barkhof criteria and CC lesion was 3.3 (95% CI 1.9-5.7). Patients not fulfilling the Barkhof criteria had a fourfold increased risk of MS (HR 3.8, 95% CI 1.5-9.3) when they had a lesion in the CC.

CONCLUSIONS

Corpus callosum (CC) lesion and the Barkhof criteria both predicted conversion to multiple sclerosis (MS). When both variables were combined, the association was stronger. The assessment of CC lesion may be a useful additional tool for predicting conversion to MS in patients with clinically isolated syndrome.

Visfatin genotype may modify the insulin resistance and lipid profile in type 2 diabetes patients

AIM

We investigated the role of the -4689G/T promoter variant of the visfatin gene on serum visfatin concentration and biochemical markers in T2DM patient.

METHODS

In a cross-sectional study we recruited 93 patients with type 2 diabetes. Laboratory and anthropometric measurements were included FBG, OGTT, HbA1C, lipid Profile, fasting serum visfatin, fasting serum insulin, weight, height, Body Mass Index (BMI) and waist hip ratio (WHR). Genotyping for visfatin gene was performed by using the PCR-RFLP method.

RESULTS

Our findings showed significant differences in levels of low density lipoprotein (LDL) cholesterol, total cholesterol, high density lipoprotein (HDL) cholesterol and fasting serum insulin among various types of visfatin genotype (TT, GG, and GT). This study showed a significant correlation between circulating levels of visfatin and weight, BMI, hs-CRP and fasting insulin in TT genotype. But regarding GG genotype only fasting insulin had a significant correlation with circulating visfatin.

CONCLUSIONS

Visfatin genotypes may account for insulin resistance and levels of lipid profile that may cause by different visfatin expression between genotypes.

Postlaparoscopic small bowel obstruction secondary to unrecognized nodular endometriosis of the terminal ileum

Small bowel involvement by endometriosis occurs in about 0.5% of patients, but nodular endometriosis involving the entire wall of the terminal ileum is extremely rare. Endometriotic nodules protruding into the intestinal lumen may lead to chronic, partial, or acute complete small bowel obstruction and associated clinical changes. If obstruction is partial, preoperative diagnosis is difficult and seldom suspected, and no reliable diagnostic tests are available. At laparoscopic surgery, performed typically for associated pelvic endometriosis, bowel lesions may easily be overlooked, especially in women with abdominal adhesions from earlier surgery. Surgical injury, tension tears, or postoperative edema may contribute in such cases to the development of acute, complete small bowel obstruction, which may be difficult to differentiate from postoperative ileus. The patient may deteriorate rapidly and develop abdominal sepsis and multiple organ failure with high risk of mortality. Because of increased production of tumor necrosis factor-alpha by autologous monocytes, endometriosis may predispose to development of severe sepsis and septic shock. (J Am Assoc Gynecol Laparosc 8(1):161-166, 2001)

Chronic DeltaFosB expression and increased AP-1 transcription factor binding are associated with the long term plasticity changes in epilepsy

NMDA receptor activation during status epilepticus (SE) has previously been shown to be required for epileptogenesis as well as the persistent upregulation of serum response factor (SRF) in the in vivo pilocarpine model of epilepsy. SRF is established as a regulator of the FosB gene which expresses FosB and DeltaFosB components of the AP-1 transcription factor complex. Therefore we investigated whether DeltaFosB expression and AP-1 DNA binding were also persistently elevated in pilocarpine-treated rats which chronically displayed spontaneous seizures. Using hippocampal nuclear extracts, DeltaFosB expression and AP-1 DNA binding were significantly elevated for up to one year in the epileptic animals. The expression of other fos and jun proteins was not persistently altered in epilepsy. Neuronal upregulation of DeltaFosB was correlated with regions of the brain that were involved in seizure generation and propagation. The increase in AP-1 DNA binding was shown to be dependent on NMDA receptor activation during SE. Hippocampal DeltaFosB immunostaining was seen predominately in the neuronal nuclei as opposed to other cell types. The data indicate that recurrent seizures which persistently occur in this model were not responsible for the increased DeltaFosB expression. Chronic DeltaFosB expression in epilepsy may be playing a role in the altered expression of other genes in this model and may be involved in some of the neuronal plasticity changes associated with epileptogenesis.

Bone morphogenetic proteins-2 and -4: negative growth regulators in adult retinal pigmented epithelium

PURPOSE

To determine the relative level and localization of bone morphogenetic protein (BMP-4 mRNA in the retina and retinal pigmented epithelium (RPE) under normal and pathologic conditions, to seek clues regarding possible functions.

METHODS

Clones isolated from an RPE cDNA library were sequenced and used as probes for northern blot analysis. Expression in the retina and RPE was investigated in mouse models using reverse transcription-polymerase chain reaction (RT-PCR) and in situ hybridization. The effect of recombinant proteins on RPE proliferation was investigated by thymidine incorporation.

RESULTS

Bovine clones with high homology to BMP-2 and BMP4 were isolated from a subtracted RPE cDNA library. Northern blot analysis using the clones as probes demonstrated abundant and differential expression in adult bovine RPE, but with RT-PCR and in situ hybridization, expression was also demonstrated in mouse retinal neurons. In mice with oxygen-induced ischemic retinopathy there was a striking decrease in BMP-4 mRNA in the retina within 6 hours of the onset of hypoxia that was maintained for at least 5 days. In mice with inherited photoreceptor degeneration, there was a dramatic decrease in BMP4 mRNA in retina and RPE during and after the degeneration. mRNA for the type II BMP receptor was observed in freshly isolated and cultured RPE cells, isolated retina, and freshly isolated bovine aortic endothelial cells. Thymidine incorporation in early-passage RPE cells showed a 14-fold stimulation above control with 5% serum that was decreased to 322%, 393%, and 313% in the presence of BMP-2 (10 ng/ml), BMP4 (10 ng/ml), and transforming growth factor (TGF)-,1 (2 ng/ml), respectively.

CONCLUSIONS

BMP-2 and BMP-4 may serve as negative growth regulators in the retina and RPE that are downregulated by injury, to allow tissue repair. Modulation of expression of the BMPs may provide a means to control the exaggerated wound repair that occurs in proliferative retinopathies.

Persistent increased DNA-binding and expression of serum response factor occur with epilepsy-associated long-term plasticity changes

We have previously shown that NMDA receptor activation during status epilepticus (SE) is required to produce epilepsy in in vitro and in vivo models. As in human symptomatic epilepsy, the epilepsy in these models is permanent, suggesting that the pathological activation of NMDA receptors causes permanent plasticity changes in the brain. Ca(2+) influx through NMDA receptors is known to transiently activate a key transcription factor, serum response factor (SRF). Thus, we investigated whether this factor, in terms of its expression and ability to bind to the consensus serum response element, was altered long term in the pilocarpine model of epilepsy. In hippocampal nuclear extracts, SRF binding to DNA was significantly increased over saline-injected control rats at 24 hr and at 8 weeks after the onset of SE. This increase was shown to be the result of significantly elevated levels of SRF. DNA binding was also persistently increased in the cortical, but not in the cerebellar, extracts. Hippocampal expression of SRF was localized to neurons using immunohistochemistry. NMDA receptor activation during SE was required for these changes to take place, and the spontaneous seizures seen in epileptic rats did not appear to be responsible for the increase in SRF. The results demonstrate that SRF is persistently elevated after SE in the pilocarpine model of epilepsy and support the theory that long-term gene changes in this model occur and are associated with the long-lasting plasticity changes that are initiated during epileptogenesis.

Video-assisted transportal pericardial window

Pericardial interventions for the diagnosis and treatment of pericardial disease has been evolving since the 17th century. The controversy over opened or closed procedures, the optimal guidance modality, and techniques for the creation of pericardial windows continues to be debated. This report describes two patients who received the endoscopic approach to creating a pericardial window.

Anomalous origin of the left main coronary artery from the right coronary artery ostium-interarterial subtype: angiographic definition and surgical treatment

Coronary artery anomalies occur infrequently compared to atherosclerotic disease; however, when they do occur, they can pose difficulty with coronary visualization and identification. Ectopic origin of the left mainstem coronary artery from the right sinus of Valsalva coursing between the great vessels is the rarest subtype of these anomalies, can be potentially serious, and presents unique problems for surgical treatment.