Replication of X chromosomes in complete moles

Summary DNA replication patterns of X chromosomes in complete hydatidiform moles were studied using cultured fibroblasts from three 46,XX moles resulting from duplication of a haploid sperm, and from a 46,XY mole originating from dispermy. Control cultures included skin fibroblasts from an adult woman and a female fetus as well as PB lymphocytes from an adult woman. Cultures were treated with 5-bromodeoxyuridine for the last 2–4h of the S phase, and the chromosome slides prepared were stained by the Hoechst 33258-Giemsa procedure. Each of the three XX moles studied revealed one early-replicating and one late-replicating X chromosomes, while the XY mole revealed one early-replicating X chromosome. DNA replication patterns of molar X chromosomes were similar to those of adult and fetal fibroblasts, but different from those in adult lymphocytes. These findings indicate that DNA replication kinetics of molar fibroblasts are tissue-specific rather than origin- or developmental-stage specific.     

Chemotactic macrophage subpopulations defined by macrophage chemotactic factors from delayed hypersensitivity reaction sites

The chemotactic specificity of ia-positive and -negative macrophages was studied by using three macrophage chemotactic factors (MCF), -a, -b, and -c, isolated from delayed hypersensitivity reaction (DHR) skin sites in guinea pigs. Listeria-elicited macrophages migrated toward MCF-a, -b, and -c. The chemotactic responses suggested responsive subpopulations to MCF. The electronic programmable individual cell sorter (EPICS) was used to separate macrophages with anti-la monoclonal antibodies. Ia-positive subpopulations responded to MCF-c, although they did not migrate toward MCF-a and -b. In contrast, Ia-negative subpopulations migrated toward MCF-a and -b, but not toward MCF-c. Furthermore, MCF-c attracted Ia-positive macrophages, whereas MCF-a and -b were Ia-negative in vitro; MCF did not induce Ia-negative macrophages to express surface Ia-antigens in vitro. MCF-c was able to produce massive Ia-positive macrophage accumulations when injected i.p., whereas MCF-a accumulated Ia-negative macrophages. The data suggest that MCF-a and -b, which mediate initial macrophage reactions, attract Ia-negative macrophages, and that MCF-c, which mediates predominant macrophage reactions, attract Ia-positive macrophages in the DHR.     

Hydrogen evolution by co-immobilized Chlorella vulgaris and Clostridium butyricum cells

Whole cells of Chlorella vulgaris and Clostridium butyricum were co-immobilized in 2% agar gel. NADP was suitable as an electron carrier. The rate of hydrogen evolution increased with increasing NADP concentration. The optimum conditions for hydrogen evolution were pH 7.0 and 37°C. The immobilized C. vulgaris-NADP-immobilized Cl. butyricum system continuously evolved hydrogen at a rate of 0.29–1.34 μmol/h per mg Chl for 6 days. On the other hand, the system without NADP evolved only a trace amount of hydrogen.     

Area and the rapid radiation of Hawaiian Bidens (Asteraceae)

Aim To estimate the rate of adaptive radiation of endemic Hawaiian Bidens and to compare their diversification rates with those of other plants in Hawaii and elsewhere with rapid rates of radiation. Location Hawaii. Methods Fifty‐nine samples representing all 19 Hawaiian species, six Hawaiian subspecies, two Hawaiian hybrids and an additional two Central American and two African Bidens species had their DNA extracted, amplified by polymerase chain reaction and sequenced for four chloroplast and two nuclear loci, resulting in a total of approximately 5400 base pairs per individual. Internal transcribed spacer sequences for additional outgroup taxa, including 13 non‐Hawaiian Bidens, were obtained from GenBank. Phylogenetic relationships were assessed by maximum likelihood and Bayesian inference. The age of the most recent common ancestor and diversification rates of Hawaiian Bidens were estimated using the methods of previously published studies to allow for direct comparison with other studies. Calculations were made on a per‐unit‐area basis. Results We estimate the age of the Hawaiian clade to be 1.3–3.1 million years old, with an estimated diversification rate of 0.3–2.3 species/million years and 4.8 × 10^?5 to 1.3 × 10^?4 species Myr^?1 km^?2. Bidens species are found in Europe, Africa, Asia and North and South America, but the Hawaiian species have greater diversity of growth form, floral morphology, dispersal mode and habitat type than observed in the rest of the genus world‐wide. Despite this diversity, we found little genetic differentiation among the Hawaiian species. This is similar to the results from other molecular studies on Hawaiian plant taxa, including others with great morphological variability (e.g. silverswords, lobeliads and mints). Main conclusions On a per‐unit‐area basis, Hawaiian Bidens have among the highest rates of speciation for plant radiations documented to date. The rapid diversification within such a small area was probably facilitated by the habitat diversity of the Hawaiian Islands and the adaptive loss of dispersal potential. Our findings point to the need to consider the spatial context of diversification – specifically, the relative scale of habitable area, environmental heterogeneity and dispersal ability – to understand the rate and extent of adaptive radiation.     

Salt tolerance and glycerol accumulation of a respiration-deficient mutant isolated from the petite-negative, salt-tolerant yeast Zygosaccharomyces rouxii

A respiration-deficient (RD) mutant was isolated from the petite-negative, salt-tolerant yeast Zygosaccharomyces rouxii. One strain among sixteen glycerol-non-utilizing mutants exhibited vigorous liberation of CO2 but no uptake of O2. Furthermore, this strain lacked cytochrome aa3 and had a reduced level of cytochrome b. The few mitochondria found in cells of this strain contained few or no cristae. Salt tolerance and intracellular accumulation of glycerol by the RD strain were almost equal to that of the wild-type strain in media containing NaCl up to 2.5 M. In media with more than 3 M NaCl, the growth of the RD mutant was retarded and the intracellular accumulation of glycerol was depressed in spite of ample production.     

Glycoconjugate with terminal galactose. A selective property of macrophages in developing rat lung

Pulmonary macrophages in pre- and postnatal rats were examined histochemically with a battery of peroxidase labeled lectins. Among them, Griffonia simplicifolia agglutinin I-B4 (GSA I-B4) which binds specifically to terminal alpha-galactose showed selective affinity in lung for the monocyte-macrophage line. These cells were demonstrable with GSA I-B4 from the 14th day of gestation through the adult. Extension to the ultrastructural level showed strong selective binding of this lectin to the surface of the plasmalemma and inner face of membranes limiting phagosomes in macrophages. At day 14 of gestation, monocyte-like cells positive with GSA I-B4 were scattered in various organs including lung. The lectin reactive cells in lung increased in number and size with development, infiltrating the interstitium through day 20 of gestation and then also entering the alveolar space. These findings suggest that GSA I-B4 recognizes a surface glycoconjugate characteristic of the pulmonary monocyte-macrophage line. Such selective lectin affinity offers a marker for detecting the pulmonary macrophages and examining their kinetics by light and electron microscopy.     

Inhibition of Auxin-Stimulated Elongation of Cells in Rice Lamina Joints by a Feruloylated Arabinoxylan Trisaccharide

A feruloylated arabinoxylan trisaccharide inhibited IAA-stimulatedelongation of cells in rice lamina joints. The de-esterifiedcompound, an arabinoxylan trisaccharide, did not inhibit suchelongation. This is the first report that feruloylated arabinoxylanfragments are involved in the regulation of plant growth. (Received September 18, 1991; Accepted January 13, 1992)     

Effects of intervals between jumps or bouts on osteogenic response to loading.

Prolonged loading repetitions can diminish the mechanosensitivity of bones, and increased intervals between loading might restore sensitivity. This study was designed to investigate the effects of intervals between loadings or bouts on osteogenic response. Forty female Fisher 344 rats aged 5 wk were divided into a control group and three exercise groups: 20 jumps in a single bout with a 3-s (S3) or 30-s (S30) jump interval, or 20 jumps in 2 bouts (10 x 2) separated by a 6-h interval with a 3-s jump interval (D3). After 8 wk of training, the bone masses per body weight of the femur and tibia were significantly greater in the three exercise groups than in the control group, and these values were also greater in S30 than in S3, although they were at the same level in D3 and S3. These data suggest that a longer interval (30 s) between individual loading had more effective anabolic effects on bone than a shorter interval (3 s).     

Atrial natriuretic peptide correlates with pulmonary arterial pressure and cardiac output

Correlations between plasma atrial natriuretic polypeptide (ANP) levels and hemodynamic parameters were studied in the central circulation of 12 patients with angina pectoris. The average plasma ANP level determined in the aorta was found to be 619 +/- 140 pg/ml. The plasma ANP levels showed a significant positive correlation with mean pulmonary arterial (PA) pressure, right ventricular pressure, and with cardiac index. In contrast, there was no significant correlation between plasma ANP levels and other hemodynamic variables including atrial pressure. These results suggest that hemodynamics other than the atrial pressure may have some role in modulating ANP secretion in certain pathological states.