Mutational analysis of the BMP-1 gene in patients with gastroschisis

BACKGROUND: Gastroschisis is a rare abdominal wall defect. Although the pathogenesis of gastroschisis is unknown, there is some evidence of the genetic etiology of gastroschisis. Recently, a functionally null deletion of the mouse bone morphogenic protein-1 (BMP-1) gene resulted in a phenotype that resembled a human neonate with gastroschisis. BMP-1 thus became the first potential candidate gene for gastroschisis. METHODS: To explore this possibility the authors collected blood samples from 11 patients who had gastroschisis. Mutational analysis of exons 2 to 15 of the human BMP-1 gene was performed using genomic polymerase chain reaction, single-strand conformation polymorphism analysis and direct sequencing methods. RESULTS: No mutation of the human BMP-1 gene was observed in any of these patients. CONCLUSION: Although heterogeneous etiologies might be proposed for gastroschisis, our results provide further evidence of a nongenetic etiology for gastroschisis. J Pediatr Surg 36:885-887.     

Identification of urinary metabolites of 2-methyl-3-(1,4,5,6-tetrahydronicotinoyl)pyrazolo[1,5-a]pyridine in rat, rabbit and dog.

The metabolism of KC-764 (2-methyl-3-(1,4,5,6-tetrahydronicotinoyl)pyrazolo[1,5-a]pyridine, CAS 94457-09-7) in rat, rabbit and dog was studied. The urine of animals dosed with 14C-KC-764 was extracted with ethyl acetate after treatment with beta-glucuronidase and arylsulfatase. The metabolites were purified by TLC and HPLC from the extract. Unchanged KC-764 and 16 metabolites were isolated and their structures were identified or proposed by NMR and MS spectrometry. The metabolism of KC-764 took place by the oxidation of the tetrahydropyridine ring, 6,7-position and 2-methyl group of the pyrazolopyridine ring, and their combinations. The oxidation of the tetrahydropyridine ring was predominant in dog, whereas the oxidation of the pyrazolopyridine ring was more important in rabbit. Rat produced the various metabolites by their combination. 6-Oxo and 6-ureido derivatives of the tetrahydropyridine ring were common major metabolites in all animal species studied.     

Effects of estrogen on female mouse thymus, with special reference to ER-mRNA and T cell subpopulations

The effect of estrogen (E), a female sex steroid, on the thymus tissues from castrated female mice treated with E was examined by molecular biologic, microscopic and flowcytometric techniques.

First, using an oligoprobe for E receptor (ER)-messenger RNA (ER-mRNA), one hybridized band was found at 6.2 kilobase (kb) in mouse thymus tissue, as was also the case in the human breast cancer MCF-7 cell line. ER-mRNA level in the E-treated animals was almost 3 times that in oil-treated controls.

Secondly, an electron microscopic observation indicated E treatment to bring about apoptosis of thymocytes (T cell) which were embraced by thymic stromal cells (possibly phagocytic in nature) and/or ballooning of the endoplasmic reticulum in the epithelial cells with abundant lipid droplets.

Thirdly, flow cytometric analysis demonstrated E to induce the change of T cell subpopulations: an increase in helper/inducer (L₃T⁺₄Lyt⁻₂) cells with decrease in the double positive (L₃T⁺₄Lyt⁺₂) cells.

It follows from the above findings that E may cause morphologic changes in the thymus closely related to T cell differentiation. In addition, these changes appear to derive mainly from E-induced tissue-specific gene expression including that of ER-mRNA.     

Screening of DNA copy-number aberrations in gastric cancer cell lines by array-based comparative genomic hybridization

We performed genome-wide screening for deoxyribonucleic acid copy-number aberrations in 31 gastric cancer (GC) cell lines by using custom-made comparative genomic hybridization (CGH)-array. Copy-number gains were frequently detected at 1q, 3q, 5p, 7p, 7q, 8q, 11q, 17q, 20p, 20q, Xp and Xq, and losses at 3p, 4p, 4q, 8p, 9p, 18p and 18q. With respect to histological subtypes, copy-number gains at 1p, 16p, 20p, 20q and 22q, and losses at 8p, 10p, 10q and 18q were significantly frequent in cell lines derived from tumors of the well-differentiated type, whereas copy-number gains at 1q, 7p, 7q, Xp and Xq were frequent in the undifferentiated type. Homozygous deletions were seen at five loci, whereas high-level amplifications were detected in 15 of the 31 GC cell lines; these had occurred at 24 loci, including the segment containing CDK6 (7q21.2). Amplification of that gene had never been reported in GC before. Immunohistochemical studies showed increased levels of CDK6 protein in 54 of the 292 primary GC samples we examined (18.5%). Cytoplasmic localization of CDK6, as well as CDK6 over-expression, was more frequent in well-differentiated GC than in undifferentiated tumors. Nuclear expression of CDK6 was more frequent in early stage GC than in advanced tumors, suggesting that nuclear localization of CDK6 is likely to be a prognostic factor for GC. Taken together, our data indicate that CDK6 might be involved in the pathogenesis of GC and, more generally, that CGH-arrays have a powerful potential for identifying novel cancer-related genetic changes in a variety of tumors.     

Characterization of human cytochrome P450 enzymes involved in the in vitro metabolism of perospirone

In vitro studies were carried out to identify the major contribution of CYP2C8, CYP2D6 and CYP3A4 to the metabolism of perospirone (cis-N-[4-[4-(1,2-benzisothiazol-3-yl)-1-piperazinyl]butyl]cyclohexane-1,2-dicarboximide monohydrochloride dehydrate), a novel antipsychotic agent, using human liver microsomes and expressed P450 isoforms. Quinidine (a specific inhibitor of CYP2D6) did not markedly affect the metabolism of perospirone, whereas quercetin (an inhibitor of CYP2C8) and ketoconazole (an inhibitor of CYP3A4) caused a decrease in the metabolism with human liver microsomes in a concentration dependent fashion. With 10 microM quercetin, the metabolism of perospirone was inhibited by 60.0% and with 1 microM ketoconazole almost complete inhibition was apparent. Anti-CYP2C8 and anti-CYP2D6 antisera did not exert marked effects, whereas anti-CYP3A4 antiserum caused almost complete inhibition. With expressed P450s, K(m) and V(max) values were 1.09 microM and 1.93 pmol/min/pmol P450 for CYP2C8, 1.38 microM and 5.73 pmol/min/pmol P450 for CYP2D6, and 0.245 microM and 61.3 pmol/min/pmol P450 for CYP3A4, respectively. These results indicated that the metabolism of perospirone in human liver was mainly catalysed by CYP3A4, and to a lesser extent CYP2C8 and CYP2D6 were responsible because kinetic data (K(m) and V(max)) of CYP2C8 and CYP2D6 suggested catalytic potential.     

Perforation of the colon in neonates

Purpose

Gastrointestinal perforation is a catastrophic condition in neonates, especially in premature neonates. Although perforation is commonly observed in the small intestine during the neonatal period, perforation of the colon is a rare condition. This study analyzed the clinical findings and results of perforation of the colon in neonates.

Methods

Between 1989 and 2004, 8 neonates were treated for spontaneous perforation of the colon at our institute. These patients were retrospectively reviewed.

Results

Gestational ages ranged from 36 to 41 weeks. Seven patients weighed above 2500 g, whereas one patient weighed 1800 g at birth. Perforations developed within 7 days after birth in 6 patients and before birth in two. Associated bowel diseases included rectosigmoid type of Hirschsprung's disease in two patients, immature ganglia in one, imperforate anus in one, colonic atresia in one, and necrotizing enterocolitis in one. An obvious cause was not identified in the remaining two. Six patients without definite anatomic obstructions, such as imperforate anus or colonic atresia, required evaluations for suspected Hirschsprung's disease. All 8 patients underwent colostomy and recovered from peritonitis. Seven survived, but one died of sudden infant death syndrome.

Conclusions

In this study, perforation of the colon during the neonatal period mostly occurred in term or near-term neonates and carried a good prognosis. During management, it was important to identify Hirschsprung's and its allied disorders as a cause of perforation.