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Biomedical subjects

R H Martin

Publications and source records attributed to R H Martin.

At least 127 records · Page 7Linked to original sources
PubMed1983

Segregation of chromosomes into the spermatozoa of a man heterozygous for a 14;21 Robertsonian translocation.

Twenty-four spermatozoa from a man heterozygous for a Robertsonian translocation (45,XY,-14,-21,+t(14q;21q) were studied cytogenetically in order to determine the meiotic segregation of the translocation. When compared to the expected 1:1 ratio we observed a greater number of chromosomally normal sperm than sperm with the balanced translocation. Three sperm carried the translocation in an unbalanced form.

Chromosomes, Human, 13-15↗
PubMed1983

The chromosome constitution of 1000 human spermatozoa.

Chromosomal analysis of 1000 spermatozoa from 33 normal men was performed using in vitro fertilization of zona-free golden hamster eggs. The frequency of abnormal sperm complements was 8.5%: 5.2% were aneuploid and 3.3% had a structural chromosome abnormality. The frequencies of hyperhaploid (2.4%) and hypohaploid (2.7%) sperm complements were not significantly different and all chromosome groups were represented among the aneuploid complements. The majority (22/33) of structurally abnormal complements had a chromosome break. The percentages of X and Y-bearing sperm were 53.9% and 46.1%, which is significantly different from the expected one to one ratio.

Adult↗
PubMed1983

Chromosome segregation into the spermatozoa of two men heterozygous for different reciprocal translocations.

Sperm chromosomes from two human males, each heterozygous for a different reciprocal translocation, were examined. Chromosomally normal sperm were found in equal numbers to those carrying the translocation in the balanced form, in both males. Alternate segregation was more common than adjacent segregation in both translocations. Male W. G. had a greater proportion of sperm containing chromosome abnormalities unrelated to the translocation than did J.S., the second made studied. J.S. however, had a greater frequency of chromosomally unbalanced sperm. The great majority of unbalanced sperm in both males was due to adjacent I segregation.

Adult↗
PubMed1983

A dominantly inherited cytogenetic anomaly: a possible cell division mutant.

Short-term lymphocyte cultures from three unrelated patients showed an increased frequency of mitoses with separated centromeres and splayed chromatids in the presence of colcemid. We refer to this phenomenon as premature centromere division (PCD). In two of the three patients the frequency of PCD in lymphocytes decreased when colcemid was omitted prior to harvest but was still higher than controls, whereas in the third patient, the frequency appeared unchanged. Cultured fibroblasts from the latter patient exhibited increased tetraploidy and multinucleated cells. Transmission of the trait in the three families was compatible with autosomal dominant inheritance. Time lapse cinemicrographic studies on fibroblasts from one patient demonstrate a shortened metaphase time, suggesting that the separation of chromatids observed in this patient may indeed be premature. The nature of the mutation(s) and phenotype correlation if any is unknown.

Abortion, Spontaneous↗
PubMed1983

Clinical improvement after ventricular aneurysm repair: prediction by angiographic and hemodynamic variables.

Surgical repair of a left ventricular aneurysm is associated with significant perioperative mortality and substantial mortality in the first 2 years after operation. In a retrospective review of 42 patients undergoing repair of an anteroapical aneurysm, two cardiac catheterization variables were identified that predicted a good surgical outcome, defined as perioperative survival and improved functional status. Specifically, patients with an ejection fraction of the contractile section (nonaneurysmal) of the left ventricle of 35% or greater and a left ventricular end-diastolic pressure of 25 mm Hg or less had a low perioperative mortality rate (6.5%), experienced no late mortality and had sustained clinical improvement of at least one New York Heart Association functional class (93.5%). In contrast, patients with a contractile section ejection fraction of less than 35% or a left ventricular end-diastolic pressure greater than 25 mm Hg had a higher perioperative mortality rate (27.3%), experienced a substantial late mortality rate (27.3%) or had no significant functional class improvement (9%); only 36.4% had sustained clinical improvement. This study suggests that the postoperative results of left ventricular aneurysm repair are dependent on the hemodynamic status of the nonresected left ventricle.

Adult↗
PubMed1983

The place of PRL in human lactation.

Plasma PRL levels were measured during an episode of breast feeding in fourteen women on the eighth and 42nd post-partum days. The results show that as lactation continues so the importance of absolute values of PRL diminishes, but the capability to secrete PRL in response to the suckling stimulus is maintained.

Breast Feeding↗
PubMed1983

Cytogenetic analysis of Q-banded pronuclear chromosomes in fertilized Syrian hamster eggs.

The frequency and type of chromosome abnormalities were analyzed in 917 female pronuclei in Syrian hamster eggs fertilized by human sperm. Analysis at this stage allows detection of errors which have occurred during meiosis I and II. The chromosomes were Q-banded to identify individual chromosomes and detect subtle alterations. Thirty-three (3.6%) of the hamster egg complements were abnormal: 19 (2.1%) were hypohaploid, seven (0.76%) were hyperhaploid, two (0.2%) had double aneuploidy, and five (0.5%) had a structural chromosome abnormality. Since there were significantly more hypohaploid than hyperhaploid complements, a conservative estimate of aneuploidy can be derived by doubling the frequency of hyperhaploid complements. Thus a minimal estimate of aneuploidy (single, 1.5%, and double, 0.2%) is 1.7% and a minimal estimate of the total frequency of abnormalities is 2.2%. All chromosome groups were represented among the aneuploid complements suggesting that all chromosomes are susceptible to non-disjunction.

Animals↗
PubMed1983

A detailed method for obtaining preparations of human sperm chromosomes.

A detailed technique is described for obtaining preparations of the chromosome complements of human sperm by fertilization of hamster eggs and analysis of the male pronucleus. Some of the more difficult aspects and important steps are emphasized. Technical data from 17 consecutive experiments are presented to provide an estimate of the number of karyotypes which can be obtained in an experiment.

Animals↗
PubMed1983

Sperm chromosome analysis of a man heterozygous for a pericentric inversion of chromosome 3.

Using a procedure in which human sperm were allowed to fertilize zona-free golden hamster (Mesocricetus auratus) eggs in vitro, the sperm chromosomes of a man heterozygous for inv(3) (p11q11) were analyzed. When the chromosomes were Q-banded, the inverted chromosome had the bright centromeric band on the short arm rather than on the long arm, as was seen in the normal No. 3. One hundred and eleven sperm chromosome spreads were examined, of which 64 contained the normal chromosome and 47 the inverted one. This was not significantly different from the expected 1:1 ratio. No sperm containing a chromosome imbalance caused by a crossover within the inversion were seen. Ten (8.1%) of the sperm contained chromosome abnormalities unrelated to the inversion. The ratio of X- to Y-bearing sperm was 55:45.

Animals↗
PubMed1983

Primary cardiac amyloidosis: an angiocardiographic clue to early diagnosis.

Restrictive cardiomyopathy produced by primary cardiac amyloidosis may have a clinical syndrome identical to noncalcific constrictive pericarditis. We report two patients with amyloidosis and restrictive physiology who had enlarged papillary muscles shown on left ventricular angiocardiogram. Rapid volume expansion with normal saline failed to produce ventricular filling pressure equilibration as in occult constrictive pericarditis. The absence of diastolic pressure equilibration and enlarged papillary muscles may permit early diagnosis of cardiac amyloidosis.

Amyloidosis↗
PubMed1983

Metoclopramide challenge: a measure of human lactotroph activity.

Prolactin response to an intravenous injection of 5 mg of metoclopramide was monitored in 1) normal subjects during the follicular and luteal phases of the menstrual cycle; 2) subjects with known prolactinomas, two of whom were breast-feeding; 3) subjects with suspected prolactinomas; 4) normal lactating women; and 5) normal postmenopausal women. The magnitude of prolactin released was greater in the luteal than in the follicular phase controls (P less than .001), the estrogen status being important, as further seen in the postmenopausal group. Comparison of responses in the prolactinoma and control groups is a useful diagnostic tool when assessing the possibility of a prolactinoma. Comparison of physiologically hyperprolactinemic subjects (lactating women) with pathological ones (prolactinomas) suggests that the main mode of metoclopramide's prolactin-releasing action is mediated via dopamine antagonism, though a small direct action on the lactotroph is possible.

Adult↗
PubMed1983

Congestive heart failure.

Congestive heart failure in adults should be conceptualized and dealt with as a clinical syndrome. It is neither a diagnosis nor a disease as such. Patients with heart failure present with clusters of symptoms that define sets of systemic congestion, pulmonary congestion, and inadequate cardiac output. Some have potentially correctable anatomic or metabolic defects, others have myocardial failure, and some have both as underlying causes of the syndrome. A careful analysis of the symptom clusters may provide important clues to the underlying etiologic diagnosis, which should be established before initiating therapy for heart failure.

Adult↗
PubMed1982

The role of antenatal oestrogen in post-partum human lactogenesis: evidence from oestrogen-deficient pregnancies.

Five women with severe ante-partum oestrogen deficiency (in four due to placental steroid sulphatase deficiency and in one due to an unknown cause) had low concentrations of PRL in peripheral plasma at delivery and in the puerperium. These women were unable to establish lactogenesis as assessed from plasma alpha-lactalbumin concentrations on day 4 post-partum. It is concluded that ante-partum oestrogen is required both to ensure adequate PRL secretion and to permit lactogenesis in breast tissue in response to PRL. A review of patients' records in another nine cases of placental steroid sulphatase deficiency indicates that failure to establish breast feeding is a common feature.

Estradiol↗
PubMed1982

Reliability and accuracy of the zona-free hamster ova assay in the assessment of male fertility.

The efficacy of the zona-free hamster ova assay in assessing male fertility was studied in 22 men of proven fertility, 16 of unproven fertility, and 31 who were members of infertile couples. The mean hamster ova penetration rates were significantly higher in males of proven fertility (34%) and unproven fertility (30%) than in infertile males (11%). Sperm from 21 of 22 men of proven fertility penetrated greater than 15% of ova; one man had a zero penetration rate. Sperm from 8 of 16 men of unproven fertility and 24 of 31 men of infertile couples penetrated less than 15% of ova. There was no correlation between penetration rates and any of the traditional measures of semen analysis. Two assays were performed on every male and six assays were performed on six males. There was good interassay reliability in all 69 males (r = 0.86) and in the six males with six tests (r = 0.97). The mean interassay variation was 8.6%.

Adult↗