Spatial distribution of transparent exopolymer particles in the Bransfield Strait, Antarctica

Transparent exopolymer particles (TEP) are recognized to playan important role in the flux of exported carbon to the deepocean. However, there is little information on how TEP standingstocks are affected by different hydrographic conditions andother relevant ecological factors in situ. This lack of knowledgeis particularly serious for the Southern Ocean. During Australsummer 1999, the Strait of Bransfield presented high mesoscalevariability. Two fronts were present, the Bransfield hydrographicfront and a slope front along the South Shetland Islands andseveral mesoscale anticyclonic eddies and/or frontal meanders.The spatial distributions of biological properties were largelyaffected by this complex hydrography. Chlorophyll a (Chl a)(0.05–4.81 µg L^–1), TEP (from undetectableto 346 µg GXeq L^–1) and heterotrophic bacteria (HB)(1.7–9.4 x 10⁵ cells mL^–1) were positively correlateddespite the wide hydrographic heterogeneity of the BransfieldStrait. Higher abundances of autotrophic biomass, and correspondlyhigher TEP and heterotrophic bacteria (HB), were found in themore stratified waters. TEP spatial distribution was mostlyrelated to the abundance of autotrophic biomass although localhigh TEP concentrations were not matched by similarly high valuesof Chl a in some areas where diatoms were relatively abundant.     

Hybrid origin of Japanese mice "Mus musculus molossinus": evidence from restriction analysis of mitochondrial DNA

The Japanese mouse, Mus musculus molossinus, has long been considered an independent subspecies of the house mouse. A survey of restriction- site haplotypes of mitochondrial DNA (mtDNA) showed that Japanese mice have two main maternal lineages. The most common haplotype is closely related to the mtDNA of the European subspecies M. m. musculus. The other common haplotype and two minor ones are closely related to each other and to the mtDNA of an Asiatic subspecies, M. m. castaneus. Two other rare variants are probably the result of recent contamination by European M. m. domesticus. The musculus type of mtDNA is found in the southern two-thirds of Japan, whereas the common castaneus type is found in the northern third and the minor variants are found sporadically throughout Japan. The castaneus mtDNA lineage had a few minor variants, whereas the musculus lineage was completely monomorphic. By contrast, the native population of M. m. castaneus and the Chinese and Korean musculus populations were highly polymorphic. These results suggest that M. m. molossinus is a hybrid between ancestral colonies, possibly very small, of M. m. musculus and M. m. castaneus, rather than an independent subspecies.      

Interferon effects on microfilament organization cellular fibronectin distribution, and cell motility in human fibroblasts

We have shown previously (Pfeffer et al., 1979, Exp. Cell Res. 121:111-120) that treatment of human fibroblasts, planted at a density of 2x10(3) cells/cm(2), with purified human fibroblasts interferon (640 U/ml) for 3 d at 37 degrees C decreases the overall rate of cell proliferation to 35-40 percent of the control value. In the present experiments we have characterized the phenotype of interferon-inhibited fibroblasts. The mean volume of trypsinized, interferon-treated cells was increased 31 percent abover that of control cells. The interferon-treated population was much more heterogeneous than the control population with respect to volume, and there was a considerable overlap in the volume distributions of the two populations. The cell surface area was, on the average, increased 65 percent after interferon treatment. More than 80 percent of the treated cells had enlarged nuclei, many of which were lobed, and the fraction of binucleated cells was increased fivefold. After interferon treatment, over 40 percent of the cells showed large actin-containing fibers in the form of multiple parallel arrays. Fewer than 5 percent of the control cells contained such large actin fibers. The number of actin fibers of all sizes was tripled in the treated fibroblasts on a per cell basis and, calculated per unit surface area of the cells, the number was increased 82 percent. In contrast, 10-nm filaments and microtubules did not appear to be increased in number per unit surface area of the cells. The increases per cell in the abundance of these structures were directly related to increased cell size. After interferon treatment, fibronection was distributed in arrays of long filaments covering most portions of the cell surface. Interferon treatment markedly decreased the rate of cell locomotion as well as membrane ruffling and saltatory movements of intracellular granules.     

The CD11a partner in Sus scrofa lymphocyte function-associated antigen-1 (LFA-1): mRNA cloning, structure analysis and comparison with mammalian homologues

Background  

Lymphocyte function-associated antigen-1 (LFA-1, CD11a/CD18, alphaLbeta2), the most abundant and widely expressed beta2-integrin, is required for many cellular adhesive interactions during the immune response. Many studies have shown that LFA-1 is centrally involved in the pathogenesis of several diseases caused by Repeats-in-toxin (RTX) -producing bacteria.     

The Effect of Transdermal Delivery of Fentanyl on Activity in Growing Pigs

Recently, decreased activity levels have been observed in pigs treated postoperatively with transdermal delivery of fentanyl (TD-fentanyl) after isoflurane anaesthesia. Whether the change in behaviour is related to opioid-induced sedation or to insufficient pain relief remains to be investigated. This study was therefore undertaken to evaluate the effect of TD-fentanyl 50 μg h^-1 on the activity level with and without isoflurane anaesthesia. Eight pigs (25.4 ± 5.2 kg) were submitted to a cross-over study and given two treatments; 1) fentanyl patch applied after 30 minutes of anaesthesia (treatment A/F) and 2) fentanyl patch without anaesthesia (treatment F). The pigs' behaviour was observed from a video recording instantaneously every 10 minutes for 24 h before treatments and up to 72 h after the patch attachment. Venous blood samples were taken 1, 6, 12, 24, 48 and 72 h after the patch application. The behaviour recordings showed that TD-fentanyl did not produce sedation in any pig. No differences were found between the two treatments in activity level, weight gain or serum fentanyl concentration. This concentration measured after 24 h was 0.27 ± 0.11 ng ml^-1 and 0.47 ± 0.40 ng ml^-1 in the A/F and F group, respectively.     

Phase II protocol for the evaluation of new treatments in patients with advanced gastric carcinoma: results of ECOG 5282

The study was a Phase II randomized study to evaluate the efficacy of new agents for the treatment of advanced gastric carcinoma. Patients were randomized to receive single agent chemotherapy with mitoxantrone, etoposide, aclacinomycin-A or spirogermanium. The patients were stratified by prior use of chemotherapy, prior doxorubicin use and ECOG performance status. Patients with a history of cardiac disease or prior doxorubicin exceeding a dose of 400 mg/m² were restrictively randomized to sopirogermanium or etoposide only. One hundred and fourteen patients were registered for the study. Among 98 evaluable patients there were only two partial responses (both in the etoposide arm), and one complete response in the mitoxantrone arm. The median survival on the study was 3.3 months. One hundred and six patients were analyzable for toxicity. There were four treatment-related deaths and four life-threatening toxicities. Because of low response rates and relatively high toxicities the studied compounds were not deemed worth further investigation for advanced gastric cancer.     

Host habitat assessment by a parasitoid using fungal volatiles

Background

The genus Mantella, endemic poison frogs of Madagascar with 16 described species, are known in the field of international pet trade and entered under the CITES control for the last four years. The phylogeny and phylogeography of this genus have been recently subject of study for conservation purposes. Here we report on the studies of the phylogeography of the Mantella cowani group using a fragment of 453 bp of the mitochondrial cytochrome b gene from 195 individuals from 21 localities. This group is represented by five forms: M. cowani, a critically endangered species, a vulnerable species, M. haraldmeieri, and the non-threatened M. baroni, M. aff. baroni, and M. nigricans.

Results

The Bayesian phylogenetic and haplotype network analyses revealed the presence of three separated haplotype clades: (1) M. baroni, M. aff. baroni, M. nigricans, and putative hybrids of M. cowani and M. baroni, (2) M. cowani and putative hybrids of M. cowani and M. baroni, and (3) M. haraldmeieri. The putative hybrids were collected from sites where M. cowani and M. baroni live in sympatry.

Conclusion

These results suggest (a) a probable hybridization between M. cowani and M. baroni, (b) a lack of genetic differentiation between M. baroni/M. aff. baroni and M. nigricans, (c) evidence of recent gene-flow between the northern (M. nigricans), eastern (M. baroni), and south-eastern (M. aff. baroni) forms of distinct coloration, and (d) the existence of at least three units for conservation in the Mantella cowani group.