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Biomedical subjects

A Johnson

Publications and source records attributed to A Johnson.

At least 649 records · Page 36Linked to original sources
PubMed1976

Congenital hypertrophic pyloric stenosis in Nigeria.

Thirty one infants with congenital hypertrophic pyloric stenosis seen over a five year period (1970-1974) at the University College Hospital Ibadan are reported. Most of the patients presented late. There is a much higher male predominance but a lower prevalence among Nigerian first born infants when compared with Caucasian infants. It is suggested that the condition though uncommon is not rare in African infants, and that environmental rather than genetic or racial factors may be responsible for the apparent lower prevalence.

Female↗
PubMed1976

Folate supplements during pregnancy.

In a controlled, prospective trial, the effects of giving ferrous sulphate 50 mg daily to 76 pregnant women was compared with giving ferrous sulphate 50 mg daily plus folic acid 0.5 mg daily to 82 women in 12 general practices in South-east England.No differences in obstetric complications were found between the two groups, although the evidence of some of the listed complications may be too rare for detection in a sample of patients of this size.

Anemia↗
PubMed1976

Five-year study of emergency aeromedical evacuation in the United States.

During the time period, 1 July 1969-30 June 1974, a total of 7056 patients were moved on the C-9A Nightingale on an "urgent" or "priority" basis. In support of the request for urgent airlift, an average of 21 C-9A aircraft were launched monthly. The domestic aeromedical evacuation missions were highly flexible and productive, yet inexpensive when compared with other means of moving patients. A means for determining precedence for the pickup and movement of patients is essential for an aeromedical evacuation system. When the patient is properly evaluated and the urgency for flight movement determined, unnecessary, costly, hazardous, or special flights are avoided. More than 50% of the "urgent" patients airlifted during this 5-year span originated in the central part of the United States. The Northeast and Far West were each responsible for less than 10% of the patients requiring urgent evacuation over the same period. More than 50% of the urgent patients moved were in the categories of newborn complications, burns, and neurological problems. During this period, no patient was moved on an urgent basis for a psychiatric problem--aeromedical evacuation simply becomes a very effective tool in ensuring complete health care for seriously ill patients.

Aerospace Medicine↗
PubMed1975

Micropuncture and microanalytic studies of the effect of vasectomy on the rat testis and epididymis.

Micropuncture techniques adapted for in vivo use in the male reproductive tract were used to study the effect of vasectomy on the concentration and morphology of spermatozoa in the seminiferous tubules and ductus epididymidis of the rat. Regardless of surgical technique, 85% of all rats which had previously under vasectomy developed a speratic granuloma at the proximal end of the ligated vas deferens. Vasectomy did not affect the weights of the ipsilateral (vasectomized) testes. Vasectomy without granuloma formation resulted in an elevation in the weight of the ipsilateral epididymis and an increase in the concentration of spermatozoa in the ipsilateral cauda. Vasectomy complicated by granuloma formation caused a significant increase in the ratio of the spermatocrit in the seminiferous tubule to that in the caput. In the vasectomized rat without granuloma, significantly more abnormal spermatozoa were in the caput than in the cauda; in the normal rat, the concentrations of abnormal spermatozoa in the two regions were not significantly different. Vasectomies with and without granuloma formation are distinct phenomena and should be investigated separately.

Animals↗
PubMed1975

Effect of oral contraceptives and pyridoxine on the metabolism of vitamin B6 and on plasma tryptophan and alpha-amino nitrogen.

The effect of supplementary pyridoxine on the metabolism of vitamin B6 as well as plasma tryptophan and alpha-amino nitrogen was determined in women using oral contraceptive agents. Ten women who were taking oral contraceptive agents and 11 who had never taken them served as subjects. Blood from the various biochemical measurements was drawn from fasting subjects before and after they had received an oral dose of 50 mg of pyridoxine-HCl daily fo 2 days. The use of oral contraceptive agents had no effect on the levels of blood vitamin B6, plasma pyridoxal phosphate, and plasma tryptophan. The activity of erythrocyte glutamic oxaloacetic transaminase was higher (P less than 0.05) in the oral contraceptive agent users than in the nonusers but the stimulation in vitro by pyridoxal phosphate was similar for the two groups. Plasma alpha-amino nitrogen was slightly lower in the oral contraceptive agent users than in the nonusers, but the difference was not statistically significant. The rise in blood vitamin B6 in response to pyridoxine was similar in the two groups, but the rise in plasma pyridoxal phosphate tended to be lower in the oral contraceptive agent treated subjects. Following pyridoxine supplementation, the basal activity of erythrocyte glutamic oxalocetic transaminase increased (P less than 0.01) in both groups of subjects and the stimulation in vitro by pyridoxal phosphate decreased correspondingly. Plasma tryptophan and alpha-amino nitrogen were unaffected by the supplementary pyridoxine.

Adult↗
PubMed1975

The antiglobulin microcytotoxicity assay in HL-A genotyped families.

HL-A genotyping was accomplished in 30 families (8 black, 21 white, and 1 American Indian) based on serological results obtained by our ususal lymphocytotoxicity assays. Each family was further tested by an antiglobulin microcytotoxicity method. Segregation patterns obtained by the latter method, compared with those of the former, showed few discrepancies. HL-A-identical siblings were serologically similar by the antiglobulin assay with frequency of discordant reactions at the same level as that of our regular two-stage lymphocytotoxicity assay. The antiglobulin method was shown to be highly reproducible with 1.3% discordance between duplicate tests. Many sera employed in routine cytotoxicity testing gave positive reactions with all family members in the antiglobulin assay (39% all positive by antiglobulin versus 16% by the regular cytotoxicity test), so that this method has limited usefulness for routine HL-A typing. The antiglobulin assay may have particular value, however, for identifying HL-A haplotypes in families, especially non-Caucasian, which give infrequent positive reactions in the usual lymphocytotoxicity assays.

Antibodies, Anti-Idiotypic↗
PubMed1975

Micropuncture and microanalytic studies of the rat testis and epididymis.

Micropuncture techniques developed for the study of renal physiology have been adapted for investigation of the male reproductive tract. Ultramicro specimens were obtained in vivo from the tubules of the rat testis and epididymis. These samples were analyzed for sperm morphology and concentration. The new methods developed to conduct these studies are discussed in detail. The mean in vivo spermatocrits were 0.411 plus and minus 0.029, 0.355 plus and minus 0.019, and 0;731 plus and minus 0.028 in the seminiferous tubule, caput epididymidis, and caudal spermatocrit was significantly higher than the spermatocrit in the caput or seminiferous tubule. The percentages of abnormal spermatozoa in the caput and cauda were 5.5% plus and minus .7% and 4.3% plus and minus .6%, respectively.

Animals↗