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Biomedical subjects

C Powell

Publications and source records attributed to C Powell.

At least 91 records · Page 5Linked to original sources
PubMed1985

Plasma tryptophan, age and depression.

Plasma, obtained from 131 nondepressed, otherwise healthy subjects aged from 17 to 102 years, and 22 depressed subjects aged over 70 years, was analysed for total and free tryptophan. Variation with age was found in total tryptophan. This association has not been described hitherto. There was a significant increase in total tryptophan and a non-significant increase in free tryptophan with depression. This is in contrast to some studies in younger people showing a decline in plasma tryptophan in depressed subjects.

Adolescent↗
PubMed1985

Partial purification and characterization of somatomedin from sheep serum.

A rapid, high yield preparative technique for the isolation of sheep somatomedin is reported. Purification of biologically active somatomedin from the 60% ammonium sulfate precipitate of sheep serum was accomplished using three gentle fractionation steps. Biological activity during purification was monitored using the rat adipocyte nonsuppressible insulin-like activity (NSILA) assay. A stepwise pH elution (pH 2.85, 3.5, 4.5, and 6.0) from SP-Sephadex resulted in the elimination of more than 99% of the serum proteins and a 500-fold enhancement of biological activity. The active fraction eluted at pH 6.0 and was further fractionated on Sephadex G-50 (fine) chromatography at pH 2.85. This resulted in about a 10,000-fold enhancement of activity over serum activity. The most active fractions from Sephadex chromatography were further separated on reverse phase HPLC in 0.1% trifluoroacetic acid using a linear gradient of 24-60% acetonitrile. The biological activity of the final preparation was enhanced 61,000- to 182,000-fold over that of serum (mean, 93,000-fold) when assayed in the NSILA assay. Protein yield was estimated to be 467 micrograms/liter serum. In addition to the NSILA activity, the final preparation demonstrated dose-dependent sulfation factor activity in the embryonic chick pelvic leaflet bioassay. Sheep somatomedin was active at physiological levels in both bioassays. Analysis of the somatomedin preparation by sodium dodecyl sulfate-electrophoresis at pH 8.8 showed that it was homogeneous by this criterion. The activity eluted from Sephadex G-50 was estimated to have a molecular size of 6900. Two Coomassie blue-stained bands were present in the final sheep somatomedin preparation after polyacrylamide gel electrophoresis at pH 3.2. Our purification process is a rapid, high yield technique which yields a polypeptide fraction enriched in NSILA and somatomedin-like activity. The molecular size and biological activity in the NSILA and sulfation factor assays suggest that our sheep NSILA is analogous to somatomedins purified from other species of animals.

Animals↗
PubMed1985

Creativity and the boundaries of the self: separation and engulfment anxiety in Keats and Poe.

Creativity is considered as a vicissitude of the cohesiveness or fragmentation of the self. The emergence of a self, separate from the mothering figure, requires the mother's empathic fuelling and the child's capacity to contain his gradual disillusionment with her. The process is never fully completed, allowing a potential for anxiety over threatened disintegration, along a continuum from separation anxiety (loss of the object), in a relatively cohesive self, to engulfment anxiety (loss of the self) in the less cohesive. The creative artist is uniquely sensitive to these anxieties, through his own difficulties in separating from the infantile union with the mother, or in mourning an object that dies during his childhood. The artist draws on his unconscious experience to speak to the unconscious of the audience. For the audience, it is having one's own deepest longings and deepest anxieties spoken to and spoken for that constitutes the power of creative art.

Anxiety↗
PubMed1984

Newborn screening for sickling hemoglobinopathies. Houston, 1976 to 1980.

Fifty of 52 infants with cord blood hemoglobin electrophoresis patterns indicative of a possible sickling hemoglobinopathy (SH) were followed up prospectively. A retrospective group of 39 children whose mothers were contacted two to four years after the birth of a child with a positive newborn screening test formed a comparison group. During an average follow-up period of 30 months, children of mothers who were informed early of a positive cord blood test were hospitalized more readily for complications of an SH. During this same period, five (6%) of 88 infants with fetal and sickle hemoglobin (FS) or fetal, sickle, and C hemoglobins (FSC) in their cord blood died, all before 6 months of age. All five deaths occurred in infants whose parents were unaware of their child's disease; four of the five deaths may have been caused by sepsis. These results alone did not prove that screening significantly reduces mortality but did show that newborn screening increases parental awareness of complications and may, therefore, improve the prognosis in sickle cell disease in infancy.

Anemia, Sickle Cell↗
PubMed1983

Post-catheterisation urethral strictures. A clinical and experimental study.

Seventeen patients who developed urethral strictures following catheterisation have been studied; 14 of these (82%) were catheterised for standard monitoring purposes during and after major heart surgery, which was a coronary artery bypass graft (CABPG) in 12 cases. The possible aetiological mechanisms for the development of this complication are discussed. Animal experiments were designed and carried out to compare the effects of different catheter materials on the urethral mucosa. Silicone catheters provoked the least inflammation and rubber the most. A further experiment determined the flow rates through catheters of different sizes. From our results, we suggest that the careful insertion of a small silicone catheter, distally fixed, is least likely to induce stricture formation.

Adolescent↗
PubMed1983

Influence of personal and academic experiences on formation of attitudes toward mentally retarded adults.

Attitudes toward mentally retarded adults of 135 students majoring in special education, education, and social work were studied. Educational and personal experiences having to do with mentally retarded adults were compared. Correlations were low to moderate for the personal and academic experiences of the three groups as well as with their attitudes toward mentally retarded adults. Differences in attitude could not be explained by statistically controlling any variables.

Adult↗
PubMed1983

An evaluation of giving the Jamaican government school meal to a class of children.

We evaluated the effects of giving the standard Jamaican government school meal to a class of school children. Unlike many other school-feeding studies, this project was carefully controlled and carried out with undernourished children who had low levels of school attendance and achievement. In spite of this, no improvement was found in the children's nutritional status as reflected by weight for age. However, small benefits were found in attendance and school achievement. These findings remained when sex, age, improvements over the previous term, and the effects of 'benevolent attention' were taken into account.

Adolescent↗
PubMed1982

An objective comparison of transurethral resection and bladder neck incision in the treatment of prostatic hypertrophy.

Transurethral resection has become the operation of choice in almost all cases of benign prostatic enlargement. However, when the gland does not exceed 30 gm. bladder neck incision is easier to perform, results in a lower morbidity, and is less likely to be followed by incontinence and retrograde ejaculation. We studied 2 groups of men with proved obstruction. Complete urodynamic investigation was done on 51 patients before and on 44 patients after the operation. We compared our subjective and objective findings in the 2 groups. The conclusion suggest that bladder neck incision is as effective as transurethral resection in relieving the obstruction of prostatic enlargement in the presence of a small gland.

Humans↗
PubMed1982

Longitudinal study of growth and development of young Jamaican children recovering from severe protein-energy malnutrition.

The developmental level and nutritional status of a group of 17 children aged between six and 24 months who were admitted to hospital with severe protein-energy malnutrition were studied from admission to hospital until 36 months after returning home. They were compared with a group of 14 adequately nourished children of similar age who had been admitted to hospital for other reasons. Initially the malnourished group were markedly behind the controls in developmental level, and they failed to reduce their deficit in hospital. Over the following 36 months they showed a gradual improvement relative to the controls in developmental level, height and head circumference, but were still significantly behind at the end of the study. In contrast, they caught up in weight for height by one month after returning home. When length of stay in hospital, age at admission, birthweight, mother's IQ and home background measures were taken into account, the direction of the differences between the two groups and significance levels were unchanged.

Body Height↗
PubMed1981

Construction of a potential bivalent vaccine strain: introduction of Shigella sonnei form I antigen genes into the galE Salmonella typhi Ty21a typhoid vaccine strain.

Shigella sonnei, an intestinal pathogen, produces a characteristic form I cell surface antigen now known to be plasmid encoded. We considered that the GalE Salmonella typhi Ty21a oral vaccine strain, highly effective against typhoid, might be modified so as to be protective also against shigellosis due to S. sonnei. The plasmid responsible for form I antigen synthesis was therefore conjugally transferred to the galE S. typhi strain. Serological studies revealed that the derivative strain produces the form I antigen in addition to the normal S. typhi somatic antigens. Testing in mice demonstrated that the derivative form I galE S. typhi strain is protective against both S. sonnei and S. typhi challenges. These data suggest that the galE S. Ty21a oral vaccine strain, which presumably stimulates the local immune system in the intestine, may also serve as a useful carrier for other antigenic determinants to protect against different intestinal infections.

Animals↗