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Biomedical subjects

R H Martin

Publications and source records attributed to R H Martin.

At least 163 records · Page 9Linked to original sources
PubMed1977

Normative standards of plasma cholesterol and triglyceride concentrations in Canadians of working age.

Fasting plasma cholesterol and triglyceride concentrations were determined for 6407 working Canadian adults aged 20 to 69 years in Toronto and Hamilton. Means, medians and 5th and 95th percentiles were ascertained from the data for men, women taking oral contraceptives or estrogen preparations, and women not taking such medication. Mean plasma cholesterol values (mg/dL) ranged in men from 168.3 at ages 20 to 24 years to 211.5 at ages 45 to 49 years, and in women using hormone preparations from 180.3 at ages 20 to 24 years to 224.2 at ages 50 to 54 years; corresponding values in women not using these preparations were 164.9 and 220.6. Plasma triglyceride means (mg/dL) ranged in men from 108.7 at ages 20 to 24 years to 166.7 at ages 40 to 44 years, in women using hormone preparations from 115.4 at ages 20 to 24 years to 145.3 at ages 45 to 59 years, and in women not using these preparations from 77.5 at ages 20 to 24 years to 112.4 at ages 50 to 54 years.

Adult↗
PubMed1977

True and false aneurysms of the left ventricle following myocardial infarction.

Anterolateral myocardial infarction resulted in the formation of both true and false aneurysms in a 75 year old man in whom severe congestive heart failure subsequently developed as the false aneurysm became progressively larger. Left ventriculography detected and quantified both aneurysms, and demonstrated reasonable function of the remaining volume-overloaded left ventricle. Resection of both aneurysms was accomplished with marked relief of symptoms. The literature on false aneurysm is reviewed, and the dilemma posed by the need to recognize false aneurysms before they become symptomatic or rupture is discussed.

Aged↗
PubMed1977

Limited clinical diagnostic specificity of technetium-99m stannous pyrophosphate myocardial imaging in acute myocardial infarction.

To test the sensitivity and specificity of technetium-99m stannous pyrophosphate myocardial imaging in the diagnosis of acute myocardial infarction, myocardial scintigrams were performed in 115 patients. Positive scintigrams were found in all 48 patients with acute myocardial infarction; uptake was localized in 29 patients with transmural infarction and diffuse in 2 patients with transmural infarction and in the remaining 17 patients with subendocardial myocardial infarction. Positive scintigrams were also found in 31 of 67 patients without clinical evidence of acute myocardial infarction. Diffusely positive scintigrams were found in 3 of 3 patients with unstable angina pectoris, 7 of 30 patients with stable angina pectoris, 4 of 13 patients who had undergone aortocoronary bypass surgery, 4 of 4 patients with congestive cardiomyopathy and 1 patient studied 1 day after direct current cardioversion. Localized uptake of 99mTc-pyrophosphate was found in 9 of 10 patients with left ventricular aneurysm and in 3 of 13 patients after aortocoronary bypass surgery. All four patients with atypical chest pain and two patients with pericarditis had normal scintigrams. Our data confirm the previously reported sensitivity of 99mTc-pyrophosphate imaging in detection of acute myocardial infarction but indicate that positive scintigrams are not specific for this entity.

Adult↗
PubMed1976

Uremic autonomic neuropathy: evaluation of ephedrine sulphate therapy for hemodialysis-induced hypotension.

The hemodynamic response to ephedrine sulphate were studied in a patient on maintenance hemodialysis therapy with chronic renal failure due to renal amyloidosis. The evaluation (including cardiac catheterization studies) and estimation of responses to Valsalva maneuvers before and after ephedrine administration documented the diagnosis of autonomic insufficiency. Oral ephedrine failed to influence the episodes of severe dialysis-induced hypotension. Also the patient did not benefit from the infusion of Aramine. These studies suggest that catecholamine stores of adrenergic nerves may be depleted in uremic patients with clinical signs of autonomic neuropathy.

Blood Pressure↗
PubMed1976

Nondisjunction in aging female mice.

Oocytes from CBA mice varying in age from 2 to 11 months were cultured to the metaphase II stage of meiosis and the chromosomes analyzed. The oocytes from three maternal age groups were compared with respect to the mean number of oocytes obtained per mouse, the frequency of maturation to metaphase II, and the frequency of numerical chromosomes abnormalities. Both the mean number of oocytes obtained per mouse and the frequency of maturation decreased markedly with maternal age. The frequency of chromosome abnormalities in the oocytes increased with maternal age from the young to the middle-aged mice but dropped off in the oldest maternal age group. No hyperploid (n + 1) oocytes were observed in the young or old group of mice, but 5.2% hyperploidy occurred in the middle-aged group. It is suggested that the lack of hyperploid oocytes in the old CBA females might be due to a threshold effect in which oocytes that are damaged by the number of univalents present at metaphase I become atretic and do not progress to metaphase II. The frequency of diploid (2n) oocytes was 1.7% and was not maternal-age dependent.

Aging↗
PubMed1976

Technetium 99m stannous pyrophosphate myocardial imaging in patients with and without left ventricular aneurysm.

To further explore the usefulness of technetium 99m pyrophosphate (99mTc-PYP) myocardial imaging and test its validity in the diagnosis of acute myocardial infarction, 99mTc-PYP myocardial scintigrams were performed in 50 patients. Out of 28 patients with acute myocardial infarction, myocardial scintigrams demonstrated localized activity in the 15 patients with transmural, and diffuse activity in the 13 patients with subendocardial myocardial infarction. Twenty-two patients with significant coronary artery disease documented by coronary angiography but without acute myocardial infarction were also studied. Nine of ten patients with clinical evidence of left ventricular aneurysm from previous myocardial infarction and definite left ventricular dyskinesis had positive scintigrams with activity localized to the site of the wall motion abnormality. Two of five patients without definite aneurysm but with left ventricular akinesis also had localized uptake in the involved area of the left ventricle. Seven patients with normal left ventricular wall motion had negative scintigrams. These findings suggest caution in interpreting positive 99mTc-PYP scintigrams as being indicative of acute myocardial infarction when evidence of a left ventricular aneurysm is also present.

Acute Disease↗
PubMed1976

Neonatal jaundice--a comparison between intravenous oxytocin and oral prostaglandin E2.

The total serum bilirubin levels at two and occasionally five days after birth were studied in 162 infants whose mothers received either intravenous oxytocin or oral Prostaglandin te2 during labour, and the results were compared with those obtained in forty-two control patients. Following labour of spontaneous onset, whether the mother received intravenous oxytocin or oral Prostaglandin E2, neonatal total serum bilirubin levels were not different from those in controls. After induction by amniotomy and an active agent, higher mean total serum bilirubin levels were found in infants whose mothers received intravenous oxytocin than in those given oral prostaglandin E2; a significant rise in the total serum bilirubin level appeared to occur when mothers received a total of more than 12,000 milliunits of oxytocin or more than 4,000 milliunits per kg birthweight of the infant.

Female↗
PubMed1975

Left ventricular aneurysm. Preoperative hemodynamics, chamber volume, and results of aneurysmectomy.

Angiocardiographic characteristics of the residual contracting left ventricle (LV) have been examined in 16 patients with anterolateral ventricular aneurysms (VA). In each patient a contractile section (CS) of the LV was clearly demarcated from the remaining aneurysmal section (AS). Using a double hemispheroid model, volumes of CS and AS were separately estimated by a modified area-length method. The volume of CS plus AS agreed closely with the volume of total LV estimated by the conventional area-length method. End-diastolic volume (EDV) of total LV ranged from 79 to 312ml/72. Aneurysmal section volume ranged from 8 to 264 ml/m2. End-diastolic volume of the contractile section ranged from 52 to 159 ml/m2 (mean, 100+/-8 (se); normal, 78+/-6). Contractile section ejection fraction (EF) showed a wide range, from 15% to 79% (mean 40%+/-17% SD). Nine patients underwent resection of VA. Three of six operated patients with CS EF less than 44% died; no survivor in this group has improved by more than one functional class (New York Heart Association classification). Three operated patients had CS EF greater than 45%; all survived and are improved, two having moved from class IV to class I. These data suggest that the EF of the contracting residual LV may be an important predictor of the outcome of resection of VA.

Cardiac Output↗
PubMed1975

Vascular diseases in employed males: a perspective on preventive and remedial programs in industry.

Simple morbidity and mortality surveillance procedures have been applied at a large steel mill for several years. Analyses arising from these data are presented demonstrating, as a case in point, that vascular diseases are among the leading causes of absenteeism and are the leading cause of death among male employees. Furthermore, the strong association of hypertension with vascular mortality is clearly displayed. Finally, attempts to initiate treatment for hypertensive employees through referral to their family physicians met with rather disappointing success as only 22 of 200 referrals resulted in patient-physician interactions. Several suggestions and conclusions can be drawn from this work. First, simple surveillance procedures can be easily implemented in occupational settings and meaningful results derived. Industrial sites offer unique opportunities for epidemiologic studies. Second, vascular diseases have a devastating effect on working age males and it would appear that hypertension, as a controllable "risk factor", is a logical target for intervention programs. Third, while our information is rather limited, it would seem that traditional referrals of patients "at risk" to their family physicians is not an effective way to arrange for their treatment. For much the same reasons that industrial sites may be useful in epidemiologic studies, they may also provide a base for intervention programs for certain disease conditions. Before such programs are undertaken, however, research into their feasibility and effectiveness is required and we are hopeful that our own studies, now underway, will provide some insight in this area.

Absenteeism↗