High level of divergence of male-reproductive-tract proteins, between Drosophila melanogaster and its sibling species, D. simulans

We compared male-reproductive-tract polypeptides of Drosophila melanogaster and D. simulans by using two-dimensional gel electrophoresis. Approximately 64% of male-reproductive-tract polypeptides were identical between two randomly chosen isofemale lines from these two species, compared with 83% identity for third-instar imaginal wing-disc polypeptides. Qualitatively similar differences were found between reproductive tracts and imaginal discs when D. sechellia was compared with D. melanogaster and with D. simulans. When genic polymorphism was taken into account, approximately 10% of male- reproductive-tract polypeptides were apparently fixed for different alleles between D. melanogaster and D. simulans; this proportion is the same as that found for soluble enzymes by one-dimensional gel electrophoresis. Strikingly, approximately 20% of male-reproductive- tract polypeptides of either D. melanogaster or D. simulans had no detectable homologue in the other species. We propose that proteins of the Drosophila male reproductive tract may have diverged more extensively between species than have other types of proteins and that much of this divergence may involve large changes in levels of polypeptide expression.      

Pre-induction priming of the uterine cervix with oral prostaglandin E2 and a placebo

A double blind study was undertaken to determine the effectiveness or oral prostaglandin E2 as a means of improving the pelvic score prior to induction of labour. 48 patients who were greater than 37 were gestation and who had Bishop scores of less than 6 entered the study. Ten tablets were given on an hourly regime. Of 25 patients in the prostaglandin group, 17 were considered successes (68.0%), whereas of 23 patients who received a placebo, 9 were successes (39.1%). No adverse effects were recorded. Prostaglandin E2 is therefore considered a safe and effective method for priming the unfavourable cervix prior to induction of labour.     

Monoclonal antibodies to rabbit liver cytochrome P-448

Cytochrome P-448 (mol wt 55,000 Daltons) from rabbit liver was purified to a specific content of 16.6 nmol/mg. Mice were immunised with this preparation, their spleens removed and dissociated lymphocytes hybridised with myeloma cells. Four monoclonal antibodies against cytochrome P-448 were raised and partially characterised. All four antibodies interacted with cytochrome P-448 in intact microsomal fractions and selectively immunoadsorbed cytochrome P-448 from solubilised microsomal preparations. One of the antibodies inhibited benzo[a] pyrene hydroxylase activity in a reconstituted system, one had no effect on activity and two increased activity. The possible applications of such antibodies are discussed.     

Growth of <Emphasis Type="Italic">Helicobacter pylori</Emphasis> in a long spiral form does not alter expression of immunodominant proteins

Background  

We have previously reported that altered culture conditions (a broth media with shaking) could induce a strain of Helicobacter pylori to assume a long spiral morphology resembling that described for Helicobacter heilmannii. The present study was initiated to determine if other strains of H. pylori could be induced to assume that morphology and if doing so would alter the expression of immunodominant proteins.     

Production of Fab fragments of monoclonal antibodies using polyelectrolyte complexes

A new method for the production of monovalent Fab fragments of antibodies has been developed. Traditionally Fab fragments are produced by proteolytic digestion of antibodies in solution followed by isolation of Fab fragments. In the case of monoclonal antibodies against inactivated subunits of glyceraldehyde-3-phosphate dehydrogenase, digestion with papain resulted in significant damage of the binding sites of the Fab fragments. Antigen was covalently attached to the polycation, poly(N-ethyl-4-vinylpyridinium bromide). Proteolysis of monoclonal antibodies in the presence of the antigen-polycation conjugate followed by (i) precipitation induced by addition of polyanion, poly(methacrylic) acid, and pH shift from 7.3 to 6.5 and (ii) elution at pH 3.0 resulted in 90% immunologically competent Fab fragments. Moreover, the papain concentration required for proteolysis was 10 times less in the case of antibodies bound to the antigen-polycation conjugate than that of free antibodies in solution. The digestion of antibodies bound to the antigen-polyelectrolyte complex was less damaging, suggesting that binding to the antigen-polycation conjugate not only protected binding sites of monoclonal antibodies from proteolytic damage but also facilitated the proteolysis probably by exposing antibody molecules in a way convenient for proteolytic attack by papain.     

Ionizing radiation alters Fas antigen ligand at the cell surface and on exfoliated plasma membrane-derived vesicles: implications for apoptosis and intercellular signaling

Resident proteins that reside on the plasma membrane are continually exfoliated from the cell surface. Exfoliation is a selective, energy-dependent process that mediates intercellular communication. Ionizing radiation modulates the expression of many plasma membrane-bound growth regulators, including the "death" ligand, TNFSF6 (formerly known as FasL, CD95L). Here we report that ionizing radiation induces dose-dependent up-regulation of TNFSF6 on plasma membranes purified from SW620 cells, a TNFSF6-expressing colon cancer cell line. Serum-free medium conditioned by exposed and control cells was collected and exfoliated vesicles were obtained by ultracentrifugation. Western blot analysis of vesicles from unexposed cells and from cells treated with 10 Gy showed increased amounts of TNFSF6 compared to that on vesicles from unexposed cells. Cells treated with 4 Gy released vesicles having a low level of TNFSF6 on their surface relative to that on vesicles exfoliated from unexposed cells. When assayed for bioactivity, vesicles from unexposed cells induced the greatest level of apoptosis in TNFRSF6 (formerly known as FAS) receptor-bearing Jurkat cells (cell surviving fraction of 43.7 +/- 6.1; P < 0.05), followed by vesicles collected from cells treated with 4 Gy (79.6 +/- 2.6%; P < 0.05). Despite having a high level of TNFSF6 by Western analysis, vesicles collected from cells exposed to 10 Gy display minimal biological activity (77.9 +/- 3.2%; P < 0.05), suggesting that modification of the vesicle-associated ligand has occurred. Our results indicate that ionizing radiation increases the level of TNFSF6 exfoliated on extracellular vesicles. The data may provide a mechanism for abscopal and bystander effects after irradiation.     

Similar hypotensive responses to resistance exercise with and without blood flow restriction

Low intensity resistance exercise (RE) with blood flow restriction (BFR) has gained attention in the literature due to the beneficial effects on functional and morphological variables, similar to those observed during traditional RE without BFR, while the effects of BFR on post-exercise hypotension remain unclear. The aim of the present study was to compare the blood pressure (BP) response of trained normotensive individuals to RE with and without BFR. In this cross-over randomized trial, eight male subjects (23.8 ± 4 years, 74 ± 3 kg, 174 ± 4 cm) completed two exercise protocols: traditional RE (3 x 10 repetitions at 70% one-repetition maximum [1-RM]) and low intensity RE (3 x 15 repetitions at 20% 1-RM) with BFR. Blood pressure measurements were performed after 15 min of seated rest (0), immediately after and 10 min, 20 min, 30 min, 40 min, 50 min and 60 min after the experimental sessions. Similar hypotensive effects for systolic BP (SBP) were observed for both protocols (P < 0.05) after exercise, with no differences between groups (P > 0.05) and no statistically significant difference for diastolic BP (P > 0.05). These results suggest that in normotensive trained individuals, both traditional RE and RE with BFR induce hypotension for SBP, which is important to prevent cardiovascular disturbances.     

Adelphocorisella Miyamoto and Yasunaga newly recorded from Australia, with the description of a new species (Heteroptera: Miridae: Mirinae)

Adelphocorisella australis sp. n. is described from north Queensland. This, the first representative of the genus known from Australia, is compared with the two previously described species, both from Japan.