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Biomedical subjects

D H Carr

Publications and source records attributed to D H Carr.

At least 73 records · Page 4Linked to original sources
PubMed1978

Vagally induced gastric antral contractions and gastric emptying of a liquid test meal.

The emptying of a liquid test meal from the stomach was studied during, and in the absence of, electrical stimulation of cut ends of a thoracic branch of the vagus in anaesthetized cats. The test meal (154 mmol.1-1 NaCl and 30 mg.1-1 phenol red) was measured by collecting effluent from a duodenal fistula over a 30 min period. The stomach emptied about 60% of the meal under control conditions compared with over 90% during efferent stimulation of the vagus. The increased volumes emptied during efferent stimulation were not accounted for by secretion of gastric acid. Coincident with the vagally evoked antral contractions there was a gush of liquid from the duodenal cannula. Afferent vagal stimulation resulted in an initial marked delay of emptying followed by an acceleration so that the volume emptied after 30 min was similar to that in control experiments. Antral contractions, evoked by efferent vagal stimulation, accelerated the emptying of a liquid test meal from the stomach.

Animals↗
PubMed1978

Q-banding of chromosomes in human spontaneous abortions.

Chromosome studies of 242 spontaneous abortions were carried out by Q-banding technique. The abortuses were selected for study because they were phenotypically abnormal, had not progressed beyond 12 weeks development or were from women with repeated abortions. Chromosome anomalies were found in 126 (52%) of the abortuses. Of these, 71 (56%) were trisomies. Trisomies were found for all the autosomes except Nos. 1, 3, 5, 11, 17 and 18. Triploidy was the second commonest anomaly in this series, making up 26 (21%) of the total anomalies. About 70% of these had an XXY sex chromosome complement. Only 16 (13%) of the abortuses had X monosomy, a lower frequency than would be expected in an unselected study. Tetraploidy was found in 8 abortuses and the 5 remaining specimens had various anomalies. These included 3 translocations, a trisomy 21,X monosomy and a ring chromosome 13. Except for the greater frequency of XXY than XXX sex chromosomes in the triploids, there was no evidence of a distortion of the sex ratio, either among the trisomic or among the chromosomally normal abortuses.

Abortion, Spontaneous↗
PubMed1977

An experimental study of trophoblast growth in the lung.

Trophoblast can be grown from blastocysts or ectoplacental cones of the mouse in a variety of extrauterine sites. An attempt was made to grow trophoblast in the lung under various conditions. In 94 mice, blastocysts, or cones, were introduced into the lung through the vascular system. Trophoblast growth never occurred. However, when blastocysts, or cones, were introduced directly into the lung, trophoblast grew in 30-50% of mice, depending on technique. Failure to grow from the intravascular position does not appear to be due to liberation of common products of ischemia because blastocysts produced normal trophoblast in the liver when implanted via the portal system, even in the presence of extensive necrosis. The inhibiting factor, which is apparently produced in the lung, is being investigated.

Animals↗
PubMed1976

Four familial translocations ascertained through spontaneous abortions.

In a study of 514 spontaneous abortions, 194 were found to have a chromosome anomaly. Of these, 4 (2.1%) were unbalanced translocations. Three of the translocations were Robertsonian (13q14q) and one was reciprocal. Each translocation was ascertained independently and each was associated with a balanced rearrangement in a carrier parent.

Abortion, Spontaneous↗
PubMed1975

Recent advances in the cytogenetic study of human spontaneous abortions.

A cytogenetic study of 27 spontaneous abortions was carried out using the Q-banding technic. The specimens were selected for study in order to increase the likelihood of finding a chromosome anomaly. Sixteen of 27 specimens (59%) showed a chromosome abnormality. Trisomy was found in 9 of the specimens, and the chromosomes involved were Nos. 2, 8, 14, 16, and 22. There were 5 triploids and 2 tetraploids. Using marker chromosomes, it was found that the extra haploid set was paternally derived in two of the triploids which were favorable for study. The Q-banding technic provides accurate identification of the extra chromosomes in trisomy. When favorable markers are present in the parents, the source of the extra haploid set can be identified in triploid abortuses.

Abortion, Spontaneous↗