Heme oxygenase-1 prevents superoxide anion-associated endothelial cell sloughing in diabetic rats

Heme oxygenase-1 (HO-1) represents a key defense mechanism against oxidative injury. Hyperglycemia has been linked to increased oxidative stress, leading to endothelial dysfunction, delayed cell replication, and enhanced apoptosis. The effect of streptozotocin (STZ)-induced diabetes on HO activity, HO-1 promoter activity, superoxide anion (O*-2, and the number of circulating endothelial cells was measured. The expression of HO-1/HO-2 protein was unchanged, but HO activity was decreased in aortas of diabetic rats compared with control (p < 0.05). High glucose decreased HO-1 promoter activity (p < 0.05). Hyperglycemia increased O*-2 and this increase was augmented with HO-1 inhibition and diminished with HO-1 upregulation (p < 0.05). Circulating endothelial cells were significantly higher in diabetic rats and were decreased or increased with administration of the HO-1 inducer (CoPP) or inhibitor (SnMP), respectively (p<0.05). In conclusion, HO-1 upregulation in diabetic rats brings about an increase in serum bilirubin, a reduction in O*-2 production, and a decrease in endothelial cell sloughing.     

Genetic analyses of several Drosophila ananassae-complex species show a low-frequency major gene for parthenogenesis that maps to chromosome 2

Parthenogenetic strains of several species have been found in the genus Drosophila. The mode of diploidization in the eggs of females has been found to be post-meiotic nuclear fusion. The genetic basis for this parthenogenesis is not understood but is believed to be under the control of a complex polygenic system. We found parthenogenetic females in an isofemale strain (LAE345) of D. pallidosa-like collected in 1981 at Lae, Papua New Guinea, and established a parthenogenetically reproducing strain. Parthenogenetic strains of D. ananassae and D. pallidosa collected at Taputimu, American Samoa had also been established by Futch (1972). D. ananassae, D. pallidosa and D. pallidosa-like are very closely related species belonging to the ananassae complex of the ananassae species subgroup of the melanogaster species group. Using these three species, we found that more than 80% of females from parthenogenetic strains produced progeny parthenogenetically and that inter-specific hybrid females also produced impaternate progeny. In the present report, we demonstrate that the mode of parthenogenesis of D. ananassae appears to be the post-meiotic nuclear doubling of a single meiotic product, and that a major gene responsible for the parthenogenesis maps to the left arm of the second chromosome of D. ananassae. We also suggest that the genetic basis for parthenogenesis capacity may be identical among the three closely related species. We discuss the function of the gene required for parthenogenesis and its significance for the evolutionary process.     

DNA replicatiion and cell-cycle progresssion of cultured mouse FM3A cells after treatment with 8-methoxypsoralen plus near-UV radiation

To investigate the response of cells to one type of DNA damage — namely DNA crosslinks — cell-cycle progression and macromolecular synthesis were studied with cultured mouse FM3A cells. Treatment of the cells with low doses of 8-methoxypsoralen (8-MOP) plus near-UV radiation (0.1 μg/ml plus 5 kJ/m² or 1.0 μg/ml plus 1–2.5 kJ/m²)_halted the progression of cells through the cell cycle temporarily for the first several hours. Then the cells resumed progression through the cell cycle, and most of the cells reached, and were finally arrested at, the G2 phase of the cycle. There was a rapid decrease of incorporation of [³H]thymidine into cellular DNA immediately after the treatment. Then, after 8 h of incubation, the incorporation of [³H]thymidine recovered to some extent depending on the dose of 8-MOP plus near-UV radiation. Thus the decrease and recovery of the incorporation of [³]Hthymidine were correlated with the halt and resumption in the cell-cycle process.Synthesis of RNA and protein was measured by determination of the amounts in the cells or by the incorporation of radioactive precursors after treatment. RNA and protein synthesis were stimulated by low doses of 8-MOP plus near-UV radiation, but inhibited severely by high doses.     

Remarkable ophidiid larva (Neobythitinae) from New Guinean waters

A new type of ophidiid larva referred to the Neobythitinae is described on the basis of one specimen (22.5 mm in standard length: SL) found in the “Dana” flatfish larval collection from New Guinean waters. It is characterized by a very high body (ca. 48% SL), with a single elongate first dorsal-fin ray and protruding abdominal cavity with a long fleshy appendage at its posteroventral end. Generic and specific affinities of the larva are discussed. It is supposed that the larva belongs to one of the Pycnocraspedum species, probably to P. squamipinne.     

Transition in the Character of Immunological Memory in Mice after Immunization

The immunological memory in antibody response of mice to bovine serum albumin (BSA) was investigated at the level of antibody-producing cells or their precursor B cells and thymus-dependent helper T cells. Spleen cells obtained from mice previously primed with alum-precipitated BSA at various times were transferred to irradiated syngeneic mice. Spleen cells from mice immunized 8 days or 64 days before presented a high degree of adoptive secondary response, whereas the adoptive response of cells from mice immunized 2 days previously was found to be inferior even to that of unprimed spleen cells. Primed spleen cells treated with anti-mouse thymocyte rabbit serum plus complement were supplemented with normal thymus cells and the restoration of the responsiveness was examined. It was suggested that the memory was carried mainly by T cells in the earlier phases of the immunological memory (2 days or 8 days after the primary immunization). On the other hand, the immunological memory in the B-cell population was shown to grow gradually toward the later phase (later than 40 days).     

Genetic analysis of female mating recognition between Drosophila ananassae and Drosophila pallidosa: application of interspecific mosaic genome lines

Drosophila ananassae and Drosophila pallidosa are closely related species that can produce viable and fertile hybrids of both sexes, although strong sexual isolation exists between the two species. Females are thought to discriminate conspecific from heterospecific males based on their courtship songs. The genetic basis of female discrimination behavior was analyzed using isogenic females from interspecific mosaic genome lines that carry homozygous recombinant chromosomes. Multiple regression analysis indicated a highly significant effect of the left arm of chromosome 2 (2L) on the willingness of females to mate with D. ananassae males. Not only 2L but also the left arm of chromosome X (XL) and the right arm of chromosome 3 (3R) had significant effects on the females' willingness to mate with D. pallidosa males. All regions with strong effects on mate choice have chromosome arrangements characterized by species-specific inversions. Heterospecific combinations of 2L and 3R have previously been suggested to cause postzygotic reproductive isolation. Thus, genes involved in premating as well as postmating isolation are located in or near chromosomal inversions. This conclusion is consistent with the recently proposed hypothesis that "speciation genes" accumulate at a higher rate in non-recombining genome regions when species divergence occurs in the presence of gene flow.     

Microscopic visualization of virus removal by dedicated filters used in biopharmaceutical processing: Impact of membrane structure and localization of captured virus particles

Virus filtration with nanometer size exclusion membranes (“nanofiltration”) is effective for removing infectious agents from biopharmaceuticals. While the virus removal capability of virus removal filters is typically evaluated based on calculation of logarithmic reduction value (LRV) of virus infectivity, knowledge of the exact mechanism(s) of virus retention remains limited. Here, human parvovirus B19 (B19V), a small virus (18–26 nm), was spiked into therapeutic plasma protein solutions and filtered through Planova™ 15N and 20N filters in scaled-down manufacturing processes. Observation of the gross structure of the Planova hollow fiber membranes by transmission electron microscopy (TEM) revealed Planova filter microporous membranes to have a rough inner, a dense middle and a rough outer layer. Of these three layers, the dense middle layer was clearly identified as the most functionally critical for effective capture of B19V. Planova filtration of protein solution containing B19V resulted in a distribution peak in the dense middle layer with an LRV >4, demonstrating effectiveness of the filtration step. This is the first report to simultaneously analyze the gross structure of a virus removal filter and visualize virus entrapment during a filtration process conducted under actual manufacturing conditions. The methodologies developed in this study demonstrate that the virus removal capability of the filtration process can be linked to the gross physical filter structure, contributing to better understanding of virus trapping mechanisms and helping the development of more reliable and robust virus filtration processes in the manufacture of biologicals.