Biomedical subjects
B Evans
Publications and source records attributed to B Evans.
Reaction of magnesium porphyrinates in polymers containing imidazole.
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Diabetes and associated variables in the South Australian Aboriginal.
Diabetes of a predominant maturity-onset type has been identified as being up to ten times more prevalent in South Australian Aborigines than in Caucasians. On the evidence provided, nutritional status and obesity are thought to be dominant in the aetiology of the hyperglycaemia, although relative hyperinsulinaemia in full blood Aborigines suggests a significant racial genetic effect. It is suggested on these and other grounds that the diabetic genotype may represent a factor of previous survival advantage to the Aboriginal, now rendered deleterious by urbanization. The degree of hyperglycaemia, and its association with hyperlipidaemia, obesity, retinal arteriovenous changes and abnormal electrocardiographic findings, accentuates the significance of the diabetes, and underlines the serious need for ongoing nutritional education in these communities.
Fate of rubella genome ribonucleic acid after immune and nonimmune virolysis in the presence of ribonuclease.
To determine whether rubella virion ribonucleic acid (RNA) becomes accessible to nuclease attack after immune lysis of the viral envelope, virions containing radioactively labeled RNA were examined in three ways with the following results. (i) Incubation of purified virus with heat-inactivated rubella convalescent human serum and guinea pig complement resulted in an increase in acid-soluble RNA. Antibody was required; the reaction was temperature dependent and was blocked by ethylenediaminetetraacetic acid. When exogenous nuclease was added prior to lysis, radioactivity in virions was reduced to 15% of that in unlysed control pellets (ii) Sucrose gradient sedimentation profiles of RNA released from lysed and unlysed virions under controlled conditions showed that the nuclease content of serum-virus mixtures was sufficient to eliminate all RNA of genome size, although degradation was not complete. (iii) Virions were also lysed by unheated human immune sera in the absence of guinea pig complement and by some, but not all, unheated antibody-negative sera.
Man was for woman made and woman made for man.
An acute bed shortage for geriatric patients two years ago resulted in a change of admitting procedure. As a result we ran a mixed sex ward as a rehabilitation unit. The nursing staff felt the atmosphere, rate of recovery and personal relationships improved from male/female company.
Testing for nitrate reduction by bacteria: the use of Cleve's acid (8-aminonaphthalene-2-sulphonic acid) to determine nitrite formation.
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Comparison of the effects of intracranial injections of 6-OHDA and guanethidine on consummatory behavior and monoamine depletion.
6-Hydroxydopamine (6-OHDA) has been used extensively to study the effects of catecholamine depletion on feeding and drinking behavior. The results from these experiments are variable and do not clarify the involvement of catecholamines in these behaviors. Guanethidine, which has been used in studies of the peripheral autonomic nervous system, provides an alternative method of catecholamine depletion. In the experiments reviewed here the effects of injections of 6-OHDA and guanethidine into the rat brain on consummatory behavior and temperature regulation have been compared and related to changes in monoamine levels as shown by fluorescence histochemistry. Injections of 6-OHDA into anterior hypothalamic areas have lethal effects on food deprived animals. This effect may be explained in terms of loss of ability to regulate temperature. Animals whose catecholamines were depleted by guanethidine injections into anterior lateral hypothalamus showed a consistent reduction in food and water intake and an elevation of body temperature. Reconciliation of these findings appears difficult. However, a comparative study of the intracranial diffusion patterns of guanethidine and 6-OHDA has revealed marked differences in the extent of diffusion as seen with the fluorescence histochemical method when injected acutely or chronically into the lateral hypothalamus, the substantia nigra or the amygdala of the rat brain. Cannulation damage extended up to 1 mm in diameter. Generalized damage was far greater for 6-OHDA (2 mm) than for guanethidine (0.3 mm). At the doses used guanethidine, but not 6-OHDA caused specific damage to catecholamine-containing neurons up to a distance of at least 3 mm from the cannula tip. Guanethidine was less selective for dopaminergic compared to noradrenergic neurons. These differences between the effects of the two drugs are explained in terms of their unique pharmacological properties and their estimated decay in CNS tissue. An attempt has been made to account for the differences in behavioral data and in particular the variability of the 6-OHDA data in terms of the differences in the type of damage produced by the two drugs and the extent of their diffusion. It is also argued that the different patterns of damage would not easily be distinguished by biochemical analysis, and further, that changes in injection volume and concentration may lead to different damage patterns.
Proceedings: Treatment of chronic proctitis with disodium cromoglycate.
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An experimental evaluation of tokens as conditioned reinforcers in retarded children.
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Long-lasting supersensitivity of the rat vas deferens to norepinephrine after chronic guanethidine administration.
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Hydratase activity of a hydrolase. Adenosine deaminase.
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Double-stranded replication form of poliovirus RNA: phenotype of heterozygous molecules.
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Long-lasting damage to the internal male genital organs and their adrenergic innervation in rats following chronic treatment with the antihypertensive drug guanethidine.
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Congenital dyserythropoietic anaemia with erythroblastic multinuclearity.
A case of congenital dyserythropoietic anaemia with erythroblastic multinuclearity in a 36-year-old woman is described and the literature reviewed. The syndrome is characterized by a protracted clinical course, a relatively mild anaemia, a low reticulocyte count, slight hyperbilirubinaemia, splenomegaly, pronounced erythroid hyperplasia with reversal of the myeloid erythroid ratio, and in particular by the presence of multinucleated erythroblasts in the marrow. The picture of ineffective erythropoiesis is confirmed by erythrokinetic studies. The present case is the forty-first to be described in the literature and is the third from Britain. Thirty-one of these have occurred in seven families but a family history has been lacking in the remaining ten. The onset of anaemia occurred in childhood in 21 of the 41 cases.
Deoxyribonucleic acid polymerase(s) of Rous sarcoma virus: effects of virion-associated endonuclease on the enzymatic product.
Purified preparations of Rous sarcoma virus (RSV) contain ribonuclease which is either a constituent of the virion surface or an adsorbed contaminant. Treatment of the virus with nonionic detergent to activate ribonucleic acid (RNA)-dependent deoxyribonucleic acid (DNA) polymerase renders the viral genome susceptible to hydrolysis by the external ribonuclease. The extent of this susceptibility can be substantially reduced by the use of limited amounts of detergent. At a concentration of detergent which provides a maximum initial rate of DNA synthesis, the degradation of endogenous viral RNA results in a reduced yield of high molecular weight DNA: RNA hybrid from the polymerase reaction. Attempts to detect virion-associated deoxyribonuclease, by using a variety of double helical DNA species as substrates, have been unsuccessful, but small amounts of nuclease activity directed against single-stranded DNA may be present in purified virus.
A new method of destroying adrenergic nerves in adult animals using guanethidine.
1. The structure of sympathetic neurones in the rat has been examined with histological, fluorescence histochemical and electron microscopical methods after chronic treatment for 6 weeks with guanethidine (25 or 30 mg/kg/day i.p.).2. Less than 2% of the nerve cell bodies in the superior cervical ganglion remained at this time and in these cells the mitochondria were badly damaged. Few fluorescent adrenergic nerve fibres were found outside the central nervous system. This situation persisted even 4 months (the longest period studied) after cessation of treatment.3. This procedure is proposed as a new method of producing sympathectomy. It has the advantage of being applicable to adult animals in a variety of experimental and pathological situations. It is uniquely advantageous for denervation of the male reproductive tract.
Multiple sclerosis and melancholia.
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[A potential transition state analog for adenosine deaminase].
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