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Biomedical subjects

D Evans

Publications and source records attributed to D Evans.

At least 271 records · Page 15Linked to original sources
PubMed1988

The effect of paternal social support on maternal disruption caused by childhood asthma.

Baseline data obtained from a study of 228 low-income Black and Hispanic mothers of children with asthma were analyzed to test the hypothesis that the presence of adults in the household, and paternal involvement in asthma care would be associated with less disruption of mothers' daily activities due to the child's asthma. The data were analyzed using multiple regression techniques. We controlled for other variables that might affect the amount of disruption that mothers reported, including the child's age and severity of asthma. The mere presence of other adults in the household, including the father, was not significantly associated with disruption. The frequency of the father's involvement in the care of the child's asthma was inversely associated with disruption regardless of his presence in the household. Hispanic ethnicity and severity of the child's asthma were directly associated with disruption while the age of the child was inversely associated with disruption. We conclude that it is a specific type of assistance (sharing asthma tasks) rendered by fathers living within or outside of the household that reduces disruption reported by mothers. The study suggests that health care providers can improve education and counseling for families who have a child with asthma by emphasizing to fathers their importance in the care of asthma, and by helping them identify specific actions they can take to manage the child's disease.

Adult↗
PubMed1988

Developmental patterns of expression and coexpression of myosin heavy chains in atria and ventricles of the avian heart.

Monoclonal antibodies (mAbs), electrophoresis, immunoblotting, and immunohistochemistry were used to determine the molecular properties of cardiac myosin heavy chain (MHC) isoforms and the regions of the developing chicken heart in which they were expressed. Adult atria expressed three electrophoretically distinct MHCs that reacted specifically with mAbs F18, F59, or S58. During embryonic Days 2-4, when the atrial and ventricular chambers are forming, MHCs that reacted with mAbs F18, F59, or S58 were expressed in both the atria and ventricles. The atria continued to express MHCs that reacted with mAbs F18, F59, or S58 at all stages of development and in the adult. In the ventricles, expression of the MHCs reacting with these mAbs was found to be developmentally regulated. By embryonic Day 16, MHC(s) reacting with mAb F18 had disappeared from the developing ventricles, whereas MHCs reacting with S58 and F59 continued to be expressed throughout the ventricles. As development continued, MHC(s) reacting with S58 in the ventricle became restricted to expression in only the ventricular conducting system. MHC(s) reacting with F59 were expressed in both the ventricular myocytes and the ventricular conducting system throughout development and in the adult. Thus, in contrast to the embryonic chicken heart where at least three MHC isoforms were expressed in both the atria and ventricles, we found in the adult chicken heart that-at a minimum-three MHC isoforms were expressed in the atria, two MHC isoforms were expressed in the ventricular conducting system, and one MHC isoform in the ventricular myocardium. MHC isoform expression in the developing avian heart appears to be more complex than previously recognized.

Animals↗
PubMed1988

The Pipflex splint for treatment of mallet finger.

A new splint is described for the treatment of mallet finger deformity. The splint is in two separate parts which maintain extension of the DIP joint and flexion of the PIP joint respectively. The results of treatment in 25 patients are presented, and are superior in our hands to those resulting from other methods of splintage. The period of treatment is shorter.

Adult↗
PubMed1988

Further analysis of nitrogen fixation (nif) genes in Azotobacter chroococcum: identification and expression in Klebsiella pneumoniae of nifS, nifV, nifM, and nifB genes and localization of nifE/N-, nifU-, nifA- and fixABC-like genes.

The results presented extend previous investigations on the genetics of nitrogen fixation in Azotobacter chroococcum and indicate that nif- and fix-like DNA is located in at least five different regions of the genome. Region I contains functional copies of nifS,V and M, as well as nifH, D and K, all of which complemented mutants of Klebsiella pneumoniae. In addition, nifE- and/or nifN-like and nifU-like DNA is located in this region. The organization of the nif cluster in region I closely resembles that of K. pneumoniae. though spread over 22 kb as compared with 14 kb. Region II contains a functional nifB gene, which complemented a K. pneumoniae nifB mutant, and seems to be adjacent to ap nifA-like gene. Region III harbours nifH*, encoding a second nitrogenase Fe-protein. Region IV contains a reiteration of nifE- on and/or nifN-like sequences, and DNA homologous to Rhizobium meliloti fixABC is present in region V. The apparent complexity of nifDNA in A. chroococcum is probably related to the two systems for N2-fixation pr present in this organism.

Azotobacter↗
PubMed1988

Symptomatology in men who were molested as children: a comparison study.

Forty male and 40 female crisis center clients, evenly divided in terms of molestation history, were examined for possible long-term sequelae of sexual abuse. Although molestation during childhood was associated with previous suicide attempts and with elevated symptomatology on the Trauma Symptom Checklist, no differences between males and females were found on these variables.

Adjustment Disorders↗
PubMed1987

The deprofessionalization of medicine. Causes, effects, and responses.

In this article, we examine the components of medical professionalism; identify the roots of the loss of professional autonomy by physicians in the United States--a process that, in effect, is leading to the deprofessionalization of American medicine; discuss why such deprofessionalization is undesirable for the society; and explore three health care delivery systems and their effects on deprofessionalization. We suggest that a system based on organizations set up and directed by physicians will be the system that best preserves medical professionalism and serves the public interest.

Foundations↗
PubMed1987

Low-birth-weight infants in the Cape Peninsula. A follow-up study at the age of 3 years.

A sample of coloured children from the Cape Town City Council area who had been of low birth weight, although a weight appropriate for gestational age, was examined at the age of approximately 3 years. The children were compared with a control group of similar social background who had been of normal birth weight. Growth parameters were compared with the National Center for Health Statistics centiles. The low-birth-weight infants had compensated well. Although they were lighter, shorter in stature and had lower intelligence quotient scores than their normal-birth-weight contemporaries, when corrected for prematurity the growth parameters and IQ did not differ significantly from those of the controls. Six per cent of the preterm infants had major and 15% minor handicaps. Infants with very low birth weights (less than 1500 g) had no more handicaps than those with low birth weights. Iron deficiency was detected in 18% of the children overall but all those who were anaemic were from the low-birth-weight groups. Between 1 and 3 years of age the low-birth-weight infants had more illnesses but no more hospital admissions than the controls.

Child Development↗
PubMed1987

Botulinum toxin A blocks glutamate exocytosis from guinea-pig cerebral cortical synaptosomes.

The exocytotic release of L-glutamate from guinea-pig cerebral cortical synaptosomes can be extensively inhibited by preincubation with botulinum neurotoxin type A at 37 degrees C for 1-2 h. The toxin has no effect on synaptosomal respiratory control, respiratory capacity, ATP synthesis, plasma-membrane 86Rb+ permeability or plasma-membrane potential, does not inhibit the entry of 45Ca2+ into the synaptosome upon depolarization and does not alter the ability of intrasynaptosomal mitochondria to sequester Ca2+. The blockade of Ca2+-dependent glutamate release may be totally reversed by the Ca2+/2 H+-exchange ionophore ionomycin, but not by increasing extracellular Ca2+ concentration. It is suggested (a) that exocytosis is triggered by the penetration of Ca2+ into an intracellular hydrophobic milieu; (b) that this stage is blocked by the toxin and (c) that ionomycin is able to bypass this block and deliver Ca2+ to the exocytotic apparatus.

Animals↗
PubMed1987

Seizure activity and cortical spreading depression monitored by an extrinsic potential-sensitive molecular probe.

Using surface fluorescence and reflectance measurements from the exposed cerebral cortex, several potential-sensitive molecular probes, primarily oxonol V, have been evaluated as indicators of electrical activity changes developing during seizure activity in the mongolian gerbil. Intraventricular injection of bicuculline, picrotoxin, or KCl produced characteristic cyclic molecular probe fluorescence intensity decreases that could be abolished by the uncoupler CCCP or the mitochondrial electron transport inhibitor rotenone. Smaller fluorophore signals were observed when KCl was applied topically to the exposed cortex. In some cases, as the animals were recovering from anoxia induced by nitrogen inhalation, oscillations similar to those due to spreading depression were observed in both the oxonol V and pyridine nucleotide signals. In all experiments, the molecular probe signals closely followed those of the intrinsic pyridine nucleotides. The drug-induced oxonol V signal alterations have been provisionally interpreted as due at least in part to the reduction of the mitochondrial membrane potential that accompanies a state 4 to state 3 transition. Measurements at the oxonol V fluorescence excitation wavelength indicated that only small changes in the reflectance signal occurred during seizure activity suggesting minimal blood volume change contributions to the extrinsic probe signal.

Animals↗
PubMed1987

The interaction of potential-sensitive molecular probes with dimyristoylphosphatidylcholine vesicles investigated by 31P-NMR and electron microscopy.

The effect of a number of commonly employed potential-sensitive molecular probes on the 31P-NMR properties of dimyristoylphosphatidylcholine vesicles at two field strengths has been investigated in order to obtain information on the location and effect of these probes on the membrane bilayer. In comparison to the control dye-free vesicle spectrum, the probes diS-C3-(5) and diS-C4-(5), when added to a vesicle suspension, cause a substantial broadening of the 31P resonance with no detectable chemical shift within an uncertainty of +/- 0.05 ppm at 24 MHz. The spin-lattice and spin-spin relaxation times are also reduced when the cyanines are present by well over 20% relative to those of the control vesicle preparation. The addition of anionic probes, including several oxonol derivatives and merocyanine 540, causes no chemical shift, line broadening, or changes in the relaxation times. Possible explanations for the failure of the anionic probes to alter the vesicle 31P-NMR properties include charge repulsion between these dyes and the phosphate group that prevents the probes from penetrating the bilayer to a depth sufficient to alter the local motion of the phosphate moiety. The 31P resonance broadening and reduction in the relaxation times caused by the two cyanines is at least in part due to an increase in vesicle size as judged by electron microscopy measurements, although an inhibition of the local phosphate motion as well cannot be completely eliminated. The cyanine-mediated increase in vesicle size appears to be due to an irreversible vesicle-fusion process possibly initiated by the screening of surface charge by these probes. The implications of these observations in relation to functional energy-transducing preparations is discussed.

Benzothiazoles↗
PubMed1987

Antianaphylactic benzophenones and related compounds.

The synthesis and biological properties of 85 benzophenones and related compounds are described. The majority of the compounds inhibit the release of leukotrienes (LT) C4 and D4 in vitro from sensitized guinea pig chopped lung. In addition, some of the compounds inhibited the release of LTs from passively sensitized human chopped lung and protected guinea pigs from the effects of anaphylaxis in a modified Herxheimer test.

Anaphylaxis↗
PubMed1987

Health care ethics: a pattern for learning.

The British Medical Association (BMA) has called upon the General Medical Council (GMC) to instruct all medical schools to provide identifiable and substantial courses on medical ethics in their undergraduate curricula. The author reviews a postgraduate scheme of study in the ethics of health-care and suggests that it could provide some useful guidelines for teaching the subject at the undergraduate level.

Curriculum↗
PubMed1987

Haemoglobinopathy screening in a 'low-risk' area of the United Kingdom: South Glamorgan, Wales.

Figures collected over 2 1/2 years of screening of women attending the antenatal clinics of South Glamorgan, Wales, showed that the percentage of women identified as a risk for haemoglobinopathy trait (7.4%) was almost twice that estimated from the 1981 Census data (4.1%) and that the incidence of a thalassaemia trait in these women (0.38% beta; 0.68% alpha) was similar to that of an area of supposedly greater risk in London (0.46% beta; 0.42% alpha). Figures from one laboratory showed that without a scrutiny of all antenatal clinic blood counts for thalassaemic indices some thalassaemia traits will be missed. The apparent incidence of the HbS trait was 0.13%, and reasons for this being an underestimate are given.

Female↗