Identification of the primate papovavirus HD as the stump-tailed macaque virus.

The recently isolated primate papovavirus HD is shown to be indistinguishable from the stump-tailed macaque virus by immunofluorescent reactivity, by restriction endonuclease analysis, and by nucleic acid hybridization assay.     

Studies on transducing phage M-1 for Rhizobium japonicum D211

Phage M-1 produced clear plaques with a halo in the lawn of Rhizobium japonicum D211. A one step growth curve of phage M-1 showed a latent period of 3 h, burst size of 55 and rise period of 2 h. The inactivation of phage M-1 was found to be dependent upon the concentraion of d-glucosomanine. The neutralization kinetics of phage M-1 by antiphage serum gave a K value (velocity constant) of 83.1 min^–1. Transduction of str and kan was studied in the presence of antiphage serum and d-glucosamine. Cotransduction of different antibiotic resistance markers suggested that the system can be further explored for high resolution mapping in R. japonicum.Abbreviations YM yeast mannitol medium - PFU plaque forming unit - moi multiplicity of infection - EOP efficiency of plating     

Complex mitochondrial DNA in Drosophila.

The larval mtDNA isolated from D. virilis, D. simulans and D. melanogaster exists in complex molecular forms in addition to the simple monomeric circular form. The frequency of circular dimers and oligomers is highly elevated in apparently normal larval tissues. These complex forms of mtDNA are separable on agarose gels. Hind III restriction endonuclease and electron microscopic analyses used in the present study have revealed that circular dimers are simply the circular concatemers of two monomeric circles which are arranged in a head-to-tail structure with no detectable heterologous regions such as insertions or deletions. The electrophoretic patterns of Hind III digested mtDNAs of D. simulans and D. melanogaster (sibling species) are identical and distinguishable from that of distantly related species, D. virilis.     

Genetic variants of cytoplasmic malate dehydrogenase (MDH:EC:1.1.1.37) in populations in England and the Indian subcontinent

Summary A new variant malate dehydrogenase is described, designated S-MDH^Ind to indicate its discovery in the Indian subcontinent pending full comparison with all other variants. It occurred during a survey of the incidence of variant S-MDH phenotypes in 4149 subjects in north-east England and 1494 subjects from several populations in the Indian region. The variants previously thought to be restricted to the New Guinea region and to African populations occurred in three English subjects in northeast England. The incidence of variant S-MDH phenotypes in other populations is summarised.     

Day-care surgery in British Columbia: a 7-year experience (1968-74).

Twenty-eight patients with symptomatic Paget''s disease of bone were treated with synthetic salmon calcitonin for periods of 9 to 42 months (average, 23 months). Serum alkaline phosphatase concentration and urinary hydroxyproline excretion, which had been elevated before treatment, were decreased by calcitonin treatment in all patients, and some decrease was sustained in 23 in association with variable decreases in pain, heat and stiffness of major joints. Improvement was sustained further in approximately half of these patients; the other half had partial return of symptoms. Calcium absorption was increased in 9 of 10 patients studied; the increase did not correlate with plasma concentrations of parathyroid hormone. The mean endogenous fecal calcium excretion was decreased significantly but there was no significant change in mean urinary calcium excretion. Mean accretion rate of calcium to bone, studied in 10 patients, was decreased by 35% after 6 months of treatment and by a further 23% 1 year later. There was no consistent effect of calcitonin treatment on bone mineral mass. No serious adverse effects of treatment such as allergic reactions were observed. Calcitonin appears to be effective initially in most patients with Paget''s disease of bone, but with long-term treatment resistance may be acquired.     

Physicochemical characterization of mitochondrial DNA from soybean

Mitochondrial DNA (mtDNA) of soybean (Glycine max L.) was isolated and its buoyant density was contrasted with that of nuclear (nDNA) and chloroplast (ctDNA) DNA. Each of the three DNAs banded at a single, characteristic buoyant density when centrifuged to equilibrium in a CsCl gradient. Buoyant densities were 1.694 g/cm³ for nDNA and 1.706 g/cm³ for mtDNA. These values correspond to G-C contents of 34.7 and 46.9%, respectively. Covalently closed, circular mtDNA molecules were isolated from soybean hypocotyls by ethidium bromide-cesium chloride density gradient centrifugation. Considerable variation in mtDNA circle size was observed by electron microscopy. There were seven apparent size classes with mean lengths of 5.9 μm (class 1), 10 μm (class 2), 12.9 μm (class 3), 16.6 μm (class 4), 20.4 μm (class 5), 24.5 μm (class 6), and 29.9 μm (class 7). In addition, minicircles were observed in all preparations. Partially denatured, circular mtDNA molecules with at least one representative from six of the seven observed size classes were mapped. In class 4, there appear to be at least three distinct denaturation patterns, indicating heterogeneity within this class. It is proposed that the mitochondrial genome of soybean is distributed among the different size circular molecules, several copies of the genome are contained within these classes and that the majority of the various size molecules may be a result of recombination events between circular molecules.     

THE EFFECTS OF RED BLOOD CELL EXTRACTS ON THE PROLIFERATION OF ERYTHROCYTE PRECURSOR CELLS, IN VIVO

Saline incubation extracts of mature erythrocytes were assayed in vivo by a variety of techniques in order to study their ability to modify the proliferation of maturing erythroid cells. Using comparable extracts from granulocytes and lymphocytes, the specificity of the effect of the red cell extract for erythroid cells was confirmed by measurement of autoradiographic labelling indices, radio-iron incorporation and spleen colony growth. The erythroid cells were found to be very sensitive to the effects of the extract, as little as 10 μg per mouse producing a maximum effect on iron incorporation. It was found that the extract does not block erythroid cell proliferation completely but simply lengthens the cell cycle, mainly by increasing the G₁ phase of the cycle. There was no effect on the committed erythroid precursor cells. The in vivo activity, specificity and non-toxicity to the cells, together with the cells' sensitivity to red cell extract suggest, therefore, that this inhibitor may play a physiological role in the control of red cell production.     

Biological control ofMythimna separata [Lep.: noctuidae] in New Zealand and its bearing on biological control strategy

A survey of parasites ofAgrotis spp. was carried out in Pakistan to find promising species for trial against noctuids especiallyAgrotis spp. andMythimna separata (Walker) in New Zealand. The parasites recorded wereApanteles ruficrus Haliday,Macrocentrus collaris Spinola,Periscepsia carbonaria Panzer,Turanogonia smirnovi,Rohdain,Ctenichneumon panzeri Wesmael andAnthrax sp. All exceptAnthrax sp. were supplied to New Zealand whereA. ruficrus andM. collaris were released in large numbers.A. ruficrus became established and is giving excellent control ofM. separata resulting in enormous economic gains. Recently it has also been recovered fromAgrotis spp. This example of biological control is significant in thatM. separata has been controlled by a parasite that was previously known from it in New Zealand. The specific status of the “A. ruficrus” already present in New Zealand requires investigation.