Rapid spectrophotometric method for determining ornithine decarboxylase using 2,4-dinitrofluorobenzene

A sensitive spectrophotometric micromethod was developed for estimation of ornithine decarboxylase (ODC) activity in animal tissues. Distinct increase in the enzymatic activity was found in regenerating and malignant liver tissues as well as in hepatomas G-27 and G-46 as compared with the corresponding tissues of control animals. The linear relationship between the optic density and content of dinitrophenyl putrescine was maintained over the range of 0 to 150 nmol per a sample. The ODC pH optimum was observed within the zone pH 6.4-6.8; it did not depend on the nature of the buffer, used for tissue homogenization. The recovery of putrescine added into the sample was equal to 102.97 +/- 2.22%. The method had an error less than 3%, its sensitivity was 0.1 nmol/sample and the reproducibility was about 100%.     

Immediate and long term effects of instrumental dilation of the sphincter of Oddi

Large dilators passed through the sphincter of Oddi do not prevent retained or recurrent common bile duct stones. Large dilators are more likely to cause postoperative pancreatitis than are small ones. Pancreatitis resulting from maximal dilation is more likely to be severe, and the patients are more likely to die from it.     

Induction of autoantibody responses to GM-CSF by hyperimmunization with an Id-GM-CSF fusion protein

Fusion proteins consisting of an Ig containing xenogenic constant regions and granulocyte-macrophage colony stimulating factor (Id-GM-CSF) are potent immunogens capable of inducing anti-idiotypic Abs after two immunizations, without the usual need for adjuvants or carrier proteins. In this study, we investigated the effects of hyperimmunization with Id-GM-CSF and found that it induces anti-GM-CSF Abs that could bind to GM-CSF and neutralize its bioactivity in vitro. However, no detrimental effects of the anti-GM-CSF activity were apparent on the general health of the animals or on their base line white blood cell counts. Mice with the anti-GM-CSF activity reconstituted their peripheral white blood cells with identical kinetics as control mice after high dose cyclophosphamide treatment, sublethal irradiation, or lethal irradiation followed by syngeneic bone marrow transplantation. Primary and secondary Ab responses to a variety of protein Ags, including an unrelated Ig Id, were not affected. However, the anti-Id response induced by an unrelated GM-CSF fusion protein that is dependent upon the GM-CSF bioactivity was impaired. To avoid any potential problems associated with inducing anti-GM-CSF Abs, we show that priming with the Id-GM-CSF protein and boosting with the Id protein alone were sufficient to induce comparable anti-Id titers without inducing anti-GM-CSF Abs. We conclude that although hyperimmunization of mice with the GM-CSF fusion protein induced neutralizing anti-GM-CSF Abs, this was of little consequence to the animals. Nevertheless, we have devised a strategy to overcome this potential limitation on the use of GM-CSF fusion proteins for immunization.     

Effects of transportation time,distance, stocking density,temperature and lairage time on incidences of pale soft exudative (PSE) and the physico-chemical characteristics of pork

The study determined the effects of transportation time, distance, stocking density, temperature and lairage time on incidences of PSE and pork quality. Frequencies of PSE cases in stocking density categories within transport duration classes were determined. General linear models, regression and the principal component (PC) analysis were used to analyse the data. Highest incidences of PSE were recorded in autumn season while lowest incidences were recorded in the spring season. Transportation time and stocking density significantly affected pH_u and ultimately PSE incidences although there were no interactive effects. Highest risks of PSE occurrence were observed with more space allowance. The highest incidences of PSE were observed for animals that had travelled for two hours while the PSE cases were lower in animals that travelled for longer times. Distance travelled and transportation time had significant effects (P < 0.05) on thawing loss (TL) % of pork. No relationships were reported between the other pre-slaughter variables and pork quality attributes. With the exception of transportation time and distance travelled which had a positive relationship with TL%, variation in other pre-slaughter variables did not affect meat quality variables. The risks of PSE occurrence were dependent on stocking density and transportation time.     

The risk of persistent paresthesia is not increased with repeated axillary block

We have identified the human papillomavirus (HPV) DNA replication initiation protein E1 as a tight-binding substrate of cyclin E/cyclin-dependent kinase (Cdk) complexes by using expression cloning. E1, a DNA helicase, collaborates with the HPV E2 protein in ori-dependent replication. E1 formed complexes with cyclin E in insect and mammalian cells, independent of Cdks and E2. Additional cyclins, including A-, B-, and F-type (but not D-type), interacted with the E1/E2 complex, and A- and E-type cyclin kinases were capable of phosphorylating E1 and E2 in vitro. Association with cyclins and efficient phosphorylation of E1 required the presence of a cyclin interaction motif (the RXL motif). E1 lacking the RXL motif displayed defects in E2-dependent HPV ori replication in vivo. Consistent with a role for Cdk-mediated phosphorylation in E1 function, an E1 protein lacking all four candidate Cdk phosphorylation sites still associated with E2 and cyclin E but was impaired in HPV replication in vitro and in vivo. Our data reveal a link between cyclin/Cdk function and activation of HPV DNA replication through targeting of Cdk complexes to the E1 replication-initiation protein and suggest a functional role for E1 phosphorylation by Cdks. The use of cyclin-binding RXL motifs is now emerging as a major mechanism by which cyclins are targeted to key substrates.     

Primary electron donors for Azotobacter chroococcum nitrogenase

Augmentation mammaplasty by the transaxillary approach seems to be a safe and anatomically sound procedure which produces consistent results with a low complication rate. Our experiences with this procedure and our modifications in the technique are described. Two instruments which were designed to facilitate the procedure are reported. An anatomical justification for the transaxillary method is made.     

Usefulness and limitations of thyrotropin measurements as a first-line test for follow-up of Graves'' patients

Although the good appearance and biocompatibility of dental porcelains, failures are still of considerable concern because of the limited properties to all ceramic system. Physical properties that might be considered ideal include high strength, resistance to abrasion, and resistance to the hostile oral environment. Porcelain has been considered by many of its physical characteristic are similar to those of enamel. In 1983 a new modality of treatment, the etched porcelain restoration was introduced by Simonsen and Calamia. Numerous investigations have shown the strength of the etched porcelain bonded to composite resin and also the clinical success of this porcelain to be used as laminated veneers and etched inlays and onlays.     

Estramustine and estrone analogs rapidly and reversibly inhibit deoxyribonucleic acid synthesis and alter morphology in cultured human glioblastoma cells

Estramustine is an estradiol-based agent that has been shown to accumulate in human glioma cells, resulting in a concentration-dependent alteration in cell size and shape within minutes and an inhibition of proliferation over 3 to 6 days. We evaluated human glioblastoma cultures with [3H]thymidine incorporation assays to determine estramustine's early effects on deoxyribonucleic acid synthesis in these tumors. Because estramustine shares a common structural motif with other antimicrotubule drugs, we synthesized four A-ring conjugates of estrone that contained a carbamate moiety but lacked nitrogen mustard. These analogs were examined by [3H]thymidine incorporation and compared with vinblastine. Greater than 70% inhibition of [3H]thymidine incorporation occurred within 1 hour of treatment with estramustine at 10(-5) mol/L, which increased to 80% inhibition at 4 hours. Ethyl carbamate JE208 was nearly as effective as estramustine in inhibiting deoxyribonucleic acid synthesis, and both were more effective than vinblastine. The inhibitory effects of estramustine and estrone analogs were reversible; vinblastine was not reversible. Although estramustine and JE208 induced similar antiproliferative and morphological changes in glioblastoma cells that persisted for at least 4 days, there was a modest recovery of morphology and thymidine incorporation with JE208 after prolonged treatment. The common findings with estramustine and JE208 suggest that these agents may have a similar mechanism of action and form the basis for the investigation of new agents that may rapidly and reversibly inhibit glioblastoma.