Avoidance of stomas and delayed anastomosis for bowel necrosis: the ''clip and drop-back'' technique

Necrotizing enterocolitis (NEC) and midgut volvulus (MGV) often are associated with extensive bowel necrosis. These cases may require extensive enterectomy and the formation of high or multiple stomas, and frequently are complicated by short bowel syndrome, excessive fluid losses, fistulas, stenosis, and skin breakdown. This report describes a "clip and drop-back" technique, followed by delayed anastomosis performed 48 to 72 hours later. The technique was successful in five severely ill infants (3 NEC, 2 MGV) with extensive necrosis, bowel perforation(s), and peritonitis, who required either a high stoma near the ligament of Treitz or multiple resections and enterostomies. This method removes obvious necrotic perforated bowel, controls contamination, avoids stomas (and their inherent complications in this age group), and preserves bowel length. All five babies survived. The technique is a useful addition to the pediatric surgeon's operative armamentarium in selective cases.     

Vitamin D and calcium in the prevention of corticosteroid induced osteoporosis: a 3 year followup

OBJECTIVE: To determine the efficacy and safety of vitamin D 50,000 units/week and calcium 1,000 mg/day in the prevention of corticosteroid induced osteoporosis. METHODS: A minimized double blind, placebo controlled trial in corticosteroid treated subjects in a tertiary care university affiliated hospital. The sample was 62 subjects with polymyalgia rheumatica, temporal arteritis, asthma, vasculitis, or systemic lupus erythematosus. The primary outcome measure was the percentage change in bone mineral density (BMD) of the lumbar spine in the 2 treatment groups from baseline to 36 mo followup. RESULTS: BMD of the lumbar spine in the vitamin D and calcium treated group decreased by a mean (SD) of 2.6% (4.1%) at 12 mo, 3.7% (4.5%) at 24 mo, and 2.2% (5.8%) at 36 mo. In the placebo group there was a decrease of 4.1% (4.1%) at 12 mo, 3.8% (5.6%) at 24 mo, and 1.5% (8.8%) at 36 mo. The observed differences between groups were not statistically significant. The difference at 36 mo was-0.693% (95% CI -5.34, 3.95). CONCLUSION: Vitamin D and calcium may help prevent the early loss of bone seen in the lumbar spine as measured by densitometry of the lumbar spine. Longterm vitamin D and calcium in those undergoing extended therapy with corticosteroids does not appear to be beneficial.     

In vitro disulfide-coupled folding of guanylyl cyclase-activating peptide and its precursor protein

Guanylyl cyclase-activating peptide II (GCAP-II), an endogenous ligand of particulate guanylyl cyclase C (GC-C), is processed from the precursor protein and circulates in human blood. GCAP-II consists of 24 amino acid residues and contains two disulfide bridges. The correct disulfide paring of GCAP-II is an absolute requirement for its biological activity. This study shows that the folding of the peptide from the reduced form yields a peptide with the native disulfide paring as a minor product and with non-native ones as major products, regardless of the presence or absence of reduced and oxidized glutathione. The results suggest that GCAP-II does not possess sufficient information to permit the adoption of the native conformation and to effectively form the correct disulfide pairing and, as a result, that GCAP-II is correctly folded by assistance of a factor(s) such as an intra- or intermolecular chaperone. We studied whether a peptide in the pro-leader sequence of the precursor protein (proGCAP-II) contains sufficient information to facilitate the folding of GCAP-II. For this purpose, we prepared proGCAP-II in Escherichia coli by a recombinant technique and examined the disulfide-coupled folding of proGCAP-II from the reduced form. proGCAP-II was quantitatively recovered with the correctly folded structure from the reduced form both in the presence and in the absence of reduced and oxidized glutathione. The protein contains only disulfide linkages at the same positions as the mature form of proGCAP-II, GCAP-II, and the biologically active isomer of GCAP-II in the molecule. These results provide evidence that the propeptide of proGCAP-II is a critical factor in the formation of the correct disulfide paring in the folding of the protein.     

Reproductive and thyroid hormone levels in rats following 90-day dietary exposure to PCB 28 (2,4,4''-trichlorobiphenyl) or PCB 77 (3,3''4,4''-tetrachlorobiphenyl)

It has been reported that suramin, an anthelminthic, trypanocidal agent and an inhibitor of P2 receptors, may antagonise N-methyl-D-aspartate (NMDA) subtype of the excitatory amino acid receptors. Both NMDA receptors and P2X subclass of P2 receptors are ligand-gated Ca2+-selective channels and, since the increased influx of Ca2+ into neurons has been linked to neurotoxicity, simultaneous inhibition of P2X and NMDA receptors in vivo by suramin could represent an effective neuroprotective treatment. We have found that suramin inhibited the binding of [3H]CGP 39653 to NMDA receptor binding sites in vitro and reduced the frequency of NMDA channel openings in patch-clamp studies. Suramin (1 mM) had no effect on [3H]kainate binding in vitro. In vivo, intracerebroventricular (I.C.V.) injections of suramin (70 nmol/brain) antagonised convulsive effects of the NMDA agonist (RS)-(tetrazol-5-yl)-glycine (TZG, LY 285265). Suramin, however, did not prevent neurotoxic lesions in the hippocampus caused by I.C.V. administration of TZG. Increasing the dose of suramin resulted in death from severe respiratory depression.     

Pretreatment evaluation of chronic hepatitis C: risks, benefits, and costs

CONTEXT: Chronic hepatitis C (CHC) infection affects nearly 4 million people in the United States. Treatment with interferon alfa-2b has been limited by its cost and low likelihood of long-term response. OBJECTIVE: To examine the cost-effectiveness of alternative pretreatment management strategies for patients with CHC. DESIGN: Decision and cost-effectiveness analysis using a Markov model to examine prevalence of genotypes, viral load, and histological characteristics in relation to the sustained response rate with treatment. Data were based on a previously published decision model and a MEDLINE literature search for hepatitis C, biopsy, and liver from 1966 to 1996. PATIENTS: A hypothetical population of patients with CHC infection and elevated serum alanine aminotransferase level. INTERVENTIONS: Combinations of liver biopsy, genotyping, and quantitative viral load determination prior to a single 6-month course of interferon alfa-2b; empirical interferon treatment; and conservative management. MAIN OUTCOME MEASURES: Proportion of sustained responders, lifetime costs, life expectancy, and quality-adjusted life expectancy. RESULTS: Strategies involving hepatitis C virus (HCV) RNA testing had marginal cost-effectiveness ratios up to $4400 per discounted quality-adjusted life-year gained but would miss up to 36% of sustained responders. Empirical interferon treatment had a marginal cost-effectiveness ratio of $12400 per discounted quality-adjusted life-year gained and reached all potential sustained responders. Strategies involving liver biopsy were more expensive and would miss 6% of sustained responders and yield slightly lower life expectancies. CONCLUSIONS: Routine liver biopsy before treatment with interferon increases the cost of managing patients with CHC without improving health outcomes. Using quantitative HCV RNA testing to guide therapy misses some potential sustained responders. Empirical interferon treatment has a marginal cost-effectiveness ratio within the bounds of other commonly accepted therapies and misses none of the sustained responders.     

Superoxide dismutase restores impaired histamine-induced increases in venular macromolecular efflux during diabetes mellitus

The goal of this study was to determine the role of oxygen radicals in impaired histamine-induced increases in venular macromolecular efflux from the hamster cheek pouch. We used intravital fluorescent microscopy and fluorescein isothiocyanate dextran (FITC-dextran; MW = 70K) to examine macromolecular extravasation from post-capillary venules in nondiabetic and diabetic (2-4 weeks after injection of streptozotocin) hamsters in response to histamine. Increases in extravasation of macromolecules were quantitated by counting venular leaky sites and by calculating clearance (ml/s x 10(-6)) of FITC-dextran-70K. In nondiabetic hamsters, superfusion with histamine (1.0 and 5.0 microM) increased venular leaky sites from 0 +/- 0 to 17 +/- 6 and 35 +/- 6 per 0.11 cm2, respectively. In addition, clearance of FITC-dextran-70K increased during superfusion with histamine. In contrast, superfusion with histamine did not increase the formation of venular leaky sites (0 +/- 0) or clearance of FITC-dextran-70K in diabetic hamsters. Next, we examined whether alterations in histamine-induced increases in macromolecular efflux in diabetic hamsters may be related to the production of oxygen radicals. We examined whether exogenous application of superoxide dismutase (150 U/ml) could restore impaired histamine-induced increases in macromolecular extravasation in diabetic hamsters. Application of superoxide dismutase did not alter histamine-induced increases in venular leaky sites or clearance of FITC-dextran-70K in nondiabetic hamsters. However, application of superoxide dismutase restored histamine-induced increases in leaky site formation and clearance of FITC-dextran-70K in diabetic hamsters towards that observed in nondiabetic hamsters. These findings suggest that oxygen radical formation appears to contribute to impaired macromolecular efflux in response to histamine during short-term diabetes mellitus.     

Strain difference in the induction of T-cell activation-associated, interferon gamma-dependent hepatic injury in mice

A single intravenous injection of concanavalin A (Con A) induces T-cell activation-associated inflammatory injury selectively in the liver. This study investigated the strain difference in the development of Con A-induced hepatic injury. Normal C57BL/6 and BALB/c spleen cells produced comparable levels of T-cell-derived lymphokines (interferon gamma [IFN-gamma], tumor necrosis factor alpha [TNF-alpha], and interleukin-2 [IL-2]) following in vitro stimulation with Con A. A single intravenous injection of Con A to C57BL/6 mice induced the plasma levels of TNF-alpha and IL-2 comparable with or slightly higher than those observed in BALB/c mice, whereas the same treatment resulted in an apparently lower level of IFN-gamma production in C57BL/6 mice. RNA from livers of Con A-treated C57BL/6 mice exhibited lower levels of IFN-gamma mRNA than RNA of BALB/c livers. Unexpectedly, a dramatic difference in the severity of hepatic injury was observed between C57BL/6 and BALB/c. Namely, the peak alanine transaminase (ALT) level was more than 15,000 U/L and inducible as early as 8 hours after injection of 0.2 mg Con A per mouse in the C57BL/6 strain, whereas the peak was approximately 3,000 U/L and induced as late as 24 hours after Con A injection in the BALB/c strain. The increase in plasma ALT levels was limited to less than 10% by injection of anti-IFN-gamma monoclonal antibody (mAb) in both strains. The C57BL/6 strain inducing lower levels of IFN-gamma exhibited higher IFN-gamma responsiveness as exemplified by the intrahepatic expression of an IFN-gamma-inducible gene, an inducible type of nitric oxide (NO) synthase (iNOS). These results indicate that, while IFN-gamma produced in vivo by activated T cells induces hepatic injury, there exists a striking strain difference in the induction of IFN-gamma-dependent hepatic injury.     

The effect of photomirex on the in vitro perfused ovary of the rat

We describe the cloning of p63, a gene at chromosome 3q27-29 that bears strong homology to the tumor suppressor p53 and to the related gene, p73. p63 was detected in a variety of human and mouse tissues, including proliferating basal cells of epithelial layers in the epidermis, cervix, urothelium, and prostate. Unlike p53, the p63 gene encodes multiple isotypes with remarkably divergent abilities to transactivate p53 reporter genes and induce apoptosis. Importantly, the predominant p63 isotypes in many epithelial tissues lack an acidic N terminus corresponding to the transactivation domain of p53. We demonstrate that these truncated p63 variants can act as dominant-negative agents toward transactivation by p53 and p63, and we suggest the possibility of physiological interactions among members of the p53 family.