Sodium binding in Halobacterium halobium measured by the nuclear magnetic resonance technique

Relaxation time measurements T₁ and T₂ of sodium in Halobacterium halobium pellets were carried out at two frequencies. From those measurements, combined with intensity measurements of the sodium in the system, estimation of the properties of the sodium ions in the system was carried out. It is suggested that three types of sodium ions are present in the bacterial pellet. (A) The extracellular sodium with properties of free solution and (B) sodium which is in the pericellular volume between the cell wall and the cell membrane. There is an exchange between type A and type B sodium. The type B sodium has (e²qQ)/h = 3.7 · 10⁷ rad/s, τ_cB = 5.2 · 10⁻⁶ s and τ_B = 1 · 10⁻³ s. The sodium of type C is bound inside the cell and undetected. It's concentration inside the cell is assumed to be 1.9 M.     

Systematic growth studies,cocultivation, and cell hybridization studies of Werner syndrome cultured skin fibroblasts

Summary The growth of 20 independently derived skin fibroblastlike (FL) cell strains from three individuals with Werner syndrome (adult progeria) was compared with the growth of ten FL cell strains from normal individuals. Population growth rates and total replicative life spans of Werner syndrome strains averaged 55% and 27%, respectively, of the growth rates and life spans of non-Werner strains. In the first few passages, four Werner syndrome strains demonstrated population growth rates in the low normal range, but the longest-lived Werner syndrome strain had only 75% of the total replicative potential of the shortest-lived normal strain. Exponential growth rates, cloning efficiencies, and saturation densities of Werner strains were also reduced, whereas cell attachment was normal. Viable cells (identified by dye exclusion) were maintained in post-replicative Werner syndrome and control cultures for periods of at least 10 months; there was no evidence of accelerated post-replicative senescence or cell death of Werner syndrome FL cells. Cocultivation of Werner syndrome and normal strains did not influence population growth rates of either strain. Two proliferating hybrid clones were obtained from fusions of normal and Werner syndrome FL cell strains and these hybrids displayed the reduced growth potential typical of Werner syndrome FL cells. These studies confirm that low growth rate and sharply reduced replicative life span are characteristic of cultured skin FL cells from patients with Werner syndrome, and they suggest that these characteristics are not affected by complementation with non-Werner FL cells.     

Myxococcus xanthus synthesizes a stabilized messenger RNA during fruiting body formation

Initial characterization of the unstable 5S-to-16S RNA fraction from developingMyxococcus xanthus cells reveals that it is rapidly labeled with radioactive RNA precursor and is associated with polyribosomes and released by puromycin from polyribosomes. The total unstable RNA fraction from 10-min pulse-labeled developing cells has a half-life of 13 min, compared with a 4-min half-life for unstable RNA (presumptive mRNA) from vegetative cells pulse-labeled for 2 min. We conclude that this developmental 5S-to-16S RNA contains messenger RNA and that this mRNA is stabilized compared with that in vegetative cells.     

Regional immunotherapy has a detrimental effect on the response to combined irradiation and chemotherapy in locally advanced non-small cell bronchogenic carcinoma

Summary Twenty-one patients with stage III M₀ non-oat cell bronchogenic carcinoma confined to the thorax were randomized to receive either intrapleural BCG (10⁷ cfu, Tice strain) or intrapleural saline 3 weeks prior to beginning combined irradiation and chemotherapy. Radiation to the primary tumor and regional nodes was given at a dose of 3,000 rad in ten sessions and was followed in 7–14 days by CAMP chemotherapy (cyclophosphamide, adriamycin, methotrexate, and procarbazine) for a planned duration of 6 months. Isoniazid, 300 mg/day, was given to all patients for 3 months starting 1 week after intrapleural therapy. There were no significant differences in pretreatment prognostic factors or in response to radiation therapy. The patients receiving intrapleural BCG in addition to radiation and chemotherapy had a median survival of 18 weeks, significantly shorter than that for the patients receiving intrapleural saline (54 weeks, P=0.017).Presented in part at the 16th Annual Meeting of the American Society of Clinical Oncology, San Diego, California, May 27, 1980     

Human ribosomal RNA gene spacer sequences are found interspersed elsewhere in the genome

A cloned EcoRI fragment containing human 18 S rRNA gene sequences was used to screen a gene library to obtain a set of 8 overlapping cloned DNA segments extending into the non-transcribed spacer region of the human ribosomal RNA gene cluster. 19.4 kb of the approx. 43-kb rDNA repeat was obtained in cloned form and mapped with restriction endonucleases. None of the clones obtained extended into 28 S rRNA sequences. A 7-kb region of non-transcribed spacer DNA shared in common between five independent clones was subjected to comparative restriction digests. It was estimated that sequences among the five different spacer isolated varied by not more than 1.0%, if all the observed differences are assumed due to point mutation. HaeII-restriction fragments from within this same 7-kb region contain sequences carried not only within the tandem repeats of the gene cluster but interspersed elsewhere in the genome. Some of these sequences correspond to the Alu family of highly repeated interspersed sequences.     

Effects of four agents that modify microtubules and microfilaments (vinblastine,colchicine, lidocaine,and cytochalasin B) on macrophage-mediated cytotoxicity to tumor cells

Summary The effects of vinblastine, colchicine, lidocaine, and cytochalasin B on tumor cell killing by BCG-activated macrophages were examined. These four drugs were selected for their action on membrane-associated cytoskeletal components, microtubules, and microfilaments. Colchicine and vinblastine, which block microtubular synthesis, inhibit macrophage-mediated tumor-cell cytotoxicity at a concentration of 10^–6 M. Cytochalasin B, which disrupts microfilaments, enhances tumor cell lysis and stasis due to activated macrophages at a concentration of 10^–7 M. Lidocaine, which may induce the disappearance of both microtubules and microfilaments, has the same inhibiting effect as vinblastine at a concentration of 5×10^–7 M. Whereas vinblastine and lidocaine seem to act on the macrophage itself, cytochalasin B exerts its effect predominantly on the tumor cell. These results suggest that microtubules and microfilaments play a role in the destruction of tumor cells by activated macrophages.     

The identification and partial characterization of a plasmid containing the gene for the membrane-associated hydrogenase from E. coli

Escherichia coli DNA was digested with restriction endonuclease PstI and ligated into the PstI site of plasmid pBR322. Recombinant plasmids that were constructed in this manner were used to transform E. coli H61, a mutant with a decreased level of hydrogenase activity. Complementation of this hydrogenase mutation identified a bacterial clone carrying the gene for the membrane-associated E. coli hydrogenase in plasmid pBL101. In E. coli minicells, the pBL101 DNA directed the synthesis of a protein of a size corresponding to that of the precursor of the E. coli membrane-associated hydrogenase, which appears to contain an uncleaved leader peptide. A restriction map of the cloned DNA was determined for 14 endonucleases.     

Diet of the golden eagle Aquila chrysaetos during the breeding season in Sweden

During a five-year period, 1975–1979, a total of 2881 prey individuals of 65 prey species were collected at 162 golden eagle nests from northern Sweden and from the island of Gotland. In northern Sweden birds are taken in higher numbers than mammals but calculated as weight the two categories are of equal importance, The main prey during the breeding season are capercaillie, black grouse, willow grouse, ptarmigan, mountain hare and reindeer fawns which together form 91% of the total food biomass. The capercaillie and the black grouse are taken more in the southern part of the coniferous region than in the northern. In contrast, in northern areas, reindeer fawns are more preyed upon than in the South, Ptarmigan and willow grouse are the most commonly captured prey species in mountain areas. The total number of reindeer fawns taken (dead and/or alive) by the Swedish golden eagle population during one summer is estimated at 600 individuals. On Gotland the golden eagles take mammals more often than in its northern distribution area. Rabbit and hedgehog arc the most important species.     

Size, maturation and the social control of sex reversal in the coral reef fish Anthais squamipinnis

A major hypothesis to explain the causal initiation of protogynous sex reversal is that females change sex upon reaching a critical size. A study of the coral reef fish Anthias squamipinnis shows that the size hypothesis does not hold. Females from two neighbouring, but spatially discrete and probably genetically homogeneous populations on Aldabra Island changed sex at distinctly different sizes. Previous laboratory and field studies in which sex reversal has followed the removal of a male from social groups have been uncontrolled and thus permit the interpretation that sex reversal is caused by non-specific social disruption or by causes other than male removal. In this study, a male was removed from each of eleven single-male and five multi-male social groups in the laboratory ( N = 8 male removals) and in the field ( N = 19 male removals). In each group, the result was that one female changed sex. Laboratory controls made it unlikely that sex reversal was induced by non-specific disruption and field observations showed that sex reversals resulted from male removals and were not coincidental, ongoing events. Previous statements that sex change is controlled by the presence or absence of a male, by inhibition of a female's tendency to change sex, or by aggression or dominance are shown, by an analysis of the complexity of issues, to be premature. Gonadal histology on 130 specimens confirmed that this species is a monandric, protogynous hermaphrodite and provided details of gonadal transformation.