Recognizing genes differentially regulated in vitro by the multiple endocrine neoplasia type 1 (MEN1) gene, using RNA interference and oligonucleotide microarrays

BACKGROUND: Data on downstream effects of MEN1 gene inactivation is scarce. In an effort to identify genes regulated by MEN1, we designed a silencing experiment in a human endocrine pancreatic tumor cell line (BON1). METHODS: By using RNA interference, MEN1 mRNA expression was knocked-down by >85%. Gene expression was assessed by oligonucleotide microarrays and compared to expression in nonsilenced controls. We also investigated if genes were differentially expressed in 6 malignant endocrine pancreatic tumors (EPTs) with homozygous MEN1 inactivation compared to 2 without MEN1 gene alterations. RESULTS: Using a cut-off of > or =2 times, 66 genes were found to be upregulated, and 22 were downregulated in the MEN1-silenced clones. We corroborated the microarray findings by performing quantitative-PCR on the RNA from the silencing experiments for 7 of the 88 differentially regulated genes. Genes involved in endocrine cell fate determination, as well as genes known to be involved in NFkappaB, Notch, and Wnt signaling pathways, were among genes verified as differentially regulated in vitro. CONCLUSIONS: The demonstration of pathways affected by silencing of MEN1 in vitro provides novel insight into neoplastic processes of potential importance in vivo, which warrants further study.     

A founder mutation in BBS2 is responsible for Bardet‐Biedl syndrome in the Hutterite population: utility of SNP arrays in genetically heterogeneous disorders

Innes AM, Boycott KM, Puffenberger EG, Redl D, MacDonald IM, Chudley AE, Beaulieu C, Perrier R, Gillan T, Wade A, Parboosingh JS. A founder mutation in BBS2 is responsible for Bardet‐Biedl syndrome in the Hutterite population: utility of SNP arrays in genetically heterogeneous disorders. Bardet‐Biedl syndrome (BBS) is a multisystem genetically heterogeneous disorder, the clinical features of which are largely the consequence of ciliary dysfunction. BBS is typically inherited in an autosomal recessive fashion, and mutations in at least 14 genes have been identified. Here, we report the identification of a founder mutation in the BBS2 gene as the cause for the increased incidence of this developmental disorder in the Hutterite population. To ascertain the Hutterite BBS locus, we performed a genome‐wide single nucleotide polymorphism (SNP) analysis on a single patient and his three unaffected siblings from a Hutterite family. The analysis identified two large SNP blocks that were homozygous in the patient but not in his unaffected siblings, one of these regions contained the BBS2 gene. Sequence analysis and subsequent RNA studies identified and confirmed a novel splice site mutation, c.472‐2A>G, in BBS2. This mutation was also found in homozygous form in three subsequently studied Hutterite BBS patients from two different leuts, confirming that this is a founder mutation in the Hutterite population. Further studies are required to determine the frequency of this mutation and its role, if any, in the expression of other ciliopathies in this population.     

What is the mechanism of flow‐mediated arterial dilatation

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Plasma chromogranin A in patients with multiple endocrine neoplasia type 1.

Plasma chromogranin A (CgA) has been claimed to be a sensitive marker for neuroendocrine tumors, but its role in the early diagnosis of multiple endocrine neoplasia type 1 (MEN 1) pancreatic endocrine tumors has not been evaluated. We measured CgA in 36 patients with MEN 1, of whom 9 lacked pancreatic involvement, 20 had biochemical evidence of pancreatic endocrine tumors, and 7 displayed radiologically detectable pancreatic tumors. CgA was also analyzed in 25 patients with sporadic pancreatic endocrine tumors, 39 subjects with inflammatory bowel disease, 7 patients harboring nonendocrine pancreatic disease, and 19 healthy controls. Four of 9 of the MEN 1 patients without pancreatic involvement had elevated CgA. Furthermore, 60% with biochemically unequivocal tumors and all with a radiologically visible tumor showed elevations. All 25 patients with sporadic pancreatic endocrine tumor had increased CgA, as had 28% of patients with inflammatory bowel disease and 57% with nonendocrine pancreatic disease. Mean day to day CgA variation was 29% (range, 0-113%) in the neuroendocrine tumor patients and 21.0% (range, 0.0-47%, within reference range) among healthy controls. In summary, nonendocrine diseases may cause elevation of CgA, and its spontaneous variation can be considerable. Plasma chromogranin A is the most sensitive of the basal markers for neuroendocrine tumors, but cannot replace other established measures when screening for early pancreatic involvement in MEN 1.     

Total cavopulmonary anastomosis using atrial septal flap: technique and early results

Introduction The Fontan procedure has undergone many modifications to avoid atrial arrhythmias and thrombus formation. We used patient’s interatrial septum as a flap to direct the inferior venacaval blood to the superior venacava. Methods Seventeen patients, aged 1 to 17 years, underwent modified total cavopulmonary anastomosis. Interatrial septum was used to create the inner half of the atrial tunnel, outer half being formed by right atrial free wall. Post-operatively, all patients underwent echocardiography. Seven patients underwent 24 hour ambulatory Holter monitoring and 6 patients underwent cardiac catheterization and cineangiography. Results There was one early death due to low cardiac output. One patient had transient supraventricular arrhythmia. Two patients had singnificant pleural effusion. Holter Monitoring reveled sinus rhythm in all 7 patients studied. Follow up ranged from 18 to 60 months and patients were evaluated as they came for follow up. Long term follow up is currently being compiled. There was one late death from a non-cardiac cause. The remaining patients were in New York Heart Association (NYHA) Class I or II. All patients were in sinus rhythm. Echocardiography and cineangiography revealed absence of obstruction or leak. Conclusions Total cavopulmonary anastomosis using autogenous atrial septum is a useful modification for classical cavopulmonary anastomosis and provides good early results.     

Results of the influenza virus surveillance in wild birds in Western part of Mongolia

ObjectiveTo present results of virological study of wild birds inhabiting Western Mongolia.MethodsOver a period of 2003–2008, we isolated 13 influenza A viruses: H1N1, H3N6, H13N8 and H4N6 subtypes. We did not isolate any H5N1 subtype, that still cause epizooty in wild birds and poultry.ResultsWe revealed taxonomic and ecological heterogeneity of the birds involved in maintenance of circulation of influenza viruses in the given territory. Influenza viruses were isolated from birds of 6 orders; among them there are species preferring water and semi-aquatic biotopes, one species preferring dry plain region, and also one species which can inhabit both dry and water biotopes.ConclusionsRepresentatives of all main orders of Western Mongolia avifauna are involved in support of influenza A virus circulation, highly pathogenic H5N1 influenza viruses were registered in Mongolia thus it's necessary to continue permanent influenza virus surveillance in wild birds' populations.     

Pattern and antibiogram of urinary tract infection at the University of Port Harcourt Teaching Hospital

ObjectiveTo explore the prevalence, pathogenicity, and antibiotic susceptibility patterns of urinary tract infections at the University of Port Harcourt Teaching Hospital.MethodsSamples from 400 patients with a presumptive diagnosis of urinary tract infection including 250 non pregnant females and 150 males were used for this study. They were distributed into two groups: children aged 2 to 17 (Group A) and adults aged 18 to 75 (Group B). The standard wire loop and agar diffusion technique were employed for culture and susceptibility testing, respectively. Data obtained were analysed using SPSS, version 14.Results30.0% of Group A and 41.0% of Group B had significant bacteriuria with 66.7% and 79.3% as females, respectively. The commonest isolates cultured were Escherichia coli (32.8%), Staphylococcus aureus (17.2%), and Klebsiella spp. (16.4%). About 76.6% of isolates were sensitive to the fluorinated quinolones, 31.2% to the aminoglycosides, and 22.7% to the urinary antiseptic, nitrofurantoin. The isolates were non-sensitive to tetracycline (93.8%), cotrimoxazole (92.2%), and nalidixic acid (86.7%). Most isolates showed non-uniform sensitivity patterns to the cephaloporins (cefuroxime and ceftazidime). Pseudomonas spp. isolates were generally resistant to the fluorinated quinolones.ConclusionThough the fluorinated quinolones are still largely effective for empirical therapy in urinary tract infections, the importance of prior sensitivity testing in checking the emergence of bacterial antibiotic resistance can not be overemphasized.     

Cancer incidence in a rural population of South Africa, 1998–2002

Cancer incidence rates and patterns are reported for a rural population, living in the Eastern Cape Province of South Africa for the period 1998–2002. The population‐based cancer registry has operated for 20 years, using both active and passive methods for case finding, through collaborations with 19 health facilities: 11 district hospitals, 7 referral hospitals and 1 regional laboratory. The age standardized incidence rates for all cancers were 73.1 per 100,000 in males and 64.1 per 100,000 in females. The leading top 5 cancers for males were oesophagus (32.7 per 100,000), lung (5.8 per 100,000), prostate (4.4 per 100,000), liver (4.4 per 100,000) and larynx (2.5 per 100,000) whereas for females they were cervix (21.7 per 100,000), oesophagus (20.2 per 100,000), breast (7.5 per 100,000), ovary (0.9 per 100,000) and liver (0.9 per 100,000). The incidence of Kaposi sarcoma was low, and higher for males (1.6 per 100,000) than females (0.3 per 100,000). Lung cancer in both males and females was relatively low compared to the high incidence of oesophagus cancer.