A New Species of Poorly Known Mayfly Genus Paegniodes Eaton (Ephemeroptera: Heptageniidae) from Vietnam

A heptageniid mayfly species Paegniodes dao sp. nov. (Ephemeroptera: Heptageniidae) is described from Vietnam. The larva is distinguished by round anterolateral margins of pronotum, triangular‐shaped labrum, rudimentary lamella and well developed fibrillae of gills 1, and light brown body that lacks distinct markings. Diagnosis, line drawings, material, and habitat data are provided.     

Stages of B-lymphocyte differentiation in acute lymphoblastic leukemia

Blasts phenotype was determined in 61 children with the acute lymphoblastic leukemia. Non-T-cell acute lymphoblastic leukemia was diagnosed in 51 children. Stages of blasts differentiation were determined with the aid of monoclonal antibodies set using alkaline phosphatase-anti-alkaline phosphatase technique. Blasts in 50 patients belonged to B subpopulation confirmed by the presence of panB CD19 and CD22 antigens. Common antigen was seen in 76.5% of the examined patients with non-T-cell acute lymphoblastic leukemia. Cases of non-T-cell acute lymphoblastic leukemia were divided into 8 subgroups depending on the antigens of B-cells differentiation. An identification of pre-B subgroups of the acute lymphoblastic leukemia indicates heterogenicity of the acute lymphoblastic leukemias in childhood and enables their classification into groups corresponding to the early stages of lymphoblasts maturation.     

Effects of wearing two different types of clothing on body temperatures during and after exercise

The experiment was conducted to investigate the human thermoregulatory responses during rest, exercise and recovery atT _a 20°C and 60% R.H. under the conditions of wearing two different types of clothing. Six healthy men wore two types of clothing: one covering the whole body area except the head (Type A, weight 1656 g), and the other covering only the trunk, upper arms and thighs (Type B, weight 996 g). The level of rectal temperature was kept significantly higher in Type B than in Type A during rest and recovery. The increased and decreased rates of rectal temperature during exercise and recovery were significantly greater in Type A than in Type B, respectively. These findings are discussed from the viewpoint of the differences of skin temperatures of the extremities between Type A and Type B.     

MHC class II sequences of an HLA-DR2 narcoleptic

Narcolepsy has a 98% association with the DR2-Dw2/DQw1 haplotype. To establish if a disease-specific allele is present in narcolepsy, a cDNA library was made from a B-cell line from a DR2,4/DQw1,3 narcoleptic. Clones encoding the two expressed DR2 chains, along with DQw1 and chains, were isolated and completely sequenced. The coding regions of these four genes were similar to published nucleotide and protein sequences from corresponding healthy controls, with some minor exceptions. The 3 untranslated region of one of the DR2 genes in the narcoleptic was extended by 42 bp. Complete sequences were not available for DQw1.2 or from healthy individuals, but first domain nucleotide sequences showed only a single nonproductive difference in DQ. Partial protein sequences of both DQ and from published data were identical. Although the effects of minor differences cannot be ruled out completely, it is concluded that there are probably no narcolepsy-specific DR or DQ / sequences, and that the alleles found in narcolepsy are representative of those found in the healthy population.     

Morphological differentiation of immobilizedClaviceps paspali mycelium during semi-continuous cultivation

Summary The morphological development ofClaviceps paspali immobilized in Ca-alginate gel was examined. During consecutive reincubations, the immobilized mycelia differentiated into swollen, arthrosporoid-like cells, which never appeared during fermentation of free mycelium. Such differentiation could be connected with the improved, prologed vitality and metabolic activity of the immobilized cells.     

Strain-dependent expression of VH gene families

The tremendous diversity of the antibody specificity repertoire stems from the ability of each developing B cell to select one out of many possible variable, diversity, and joining gene segments by specific rearrangement of the DNA. The mechanism by which V region gene segments is selected is not known. Moreover, evidence for both random and nonrandom expression of VH genes in mature B cells has been presented previously. In this report, the technique of in situ hybridization is used to accurately measure at the single cell level VH gene family expression in LPS-induced cells from several strains. In this way, at least one-third of the B cells are stimulated and a large sampling of activated splenocytes from each strain analyzed. The use of in situ hybridization eliminates any potential biases resulting from transformation protocols. In addition, because all populations of cells are analyzed by both in situ hybridization and immunocytochemical staining with anti-IgM, the proportion of cells detected by in situ hybridization could be compared with the proportion of B cells, blasts, and plasma cells in the population. It was concluded from these comparisons that the cells being detected by in situ hybridization under the conditions described are plasmablasts and plasma cells. Therefore, an accurate measure of the functional and expressed VH gene repertoire could be made. The results clearly demonstrate strain-dependent variation in VH gene family expression, particularly VH 7183 and VH J558 with up to three-fold differences observed. Thus, either there is considerable strain variation in the number of functional VH gene family segments or the expression of VH genes is not entirely random.     

Coexistence of Tetranychus urticae (Acarina: Tetranychidae) with different capacities for diapause: comparative life-history traits

Summary Individuals of the two-spotted spider mite, Tetranychus urticae Koch (Acarina: Tetranychidae), with and without a capacity for diapause, coexist in central Japan. Diapause appears to be adaptive because females in diapause suffered less mortality than non-diapausing individuals when frozen at –24°C for more than 4 h. However non-diapausing females showed good survival up to 4 h of freezing. Active non-diapausing mites survived on rose leaves in Kyoto (35°N) throughout the winters of 1988–1989 and 1989–1990. Cultures of mites with low (LD) and high (HD) diapause capacities at 18°C and 9L-15D photoperiod were successfully selected from the rose population and from a population on chrysanthemum in Nara (34.4°N). Their life-history traits at 15, 20, 25 and 30°C were characterized. HD and LD mites from both populations were of similar ages at first reproduction at 15–30° C. However, at temperatures 20° C, HD individuals produced more eggs than LD individuals, resulting in higher fecundity and intrinsic rate of natural increase. These traits allow HD individuals, which stop breeding between October and April, to increase faster in summer than LD individuals. This provides a mechanism, together with climatic fluctuations, in maintaining the coexistence of diapausing and non-diapausing T. urticae in Kyoto where winter conditions are rarely lethal to the non-diapausing individuals.