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Biomedical subjects

C E Martin

Publications and source records attributed to C E Martin.

At least 19 recordsLinked to original sources
PubMed1979

Correlation between pregnancy diagnosis by membrane slip and embryonic mortality.

In a study involving 7,477 pregnant cows (5,426 Holstein-Friesians and 2,051 Guernseys), each pregnancy was diagnosed by rectal palpation, using the membrane slip technique. Each cow was examined twice, first by a veterinary student, then by a clinician. Of the cows diagnosed pregnant, 7,058 (94.4%) calved. The embryonic death rate in cows examined during the first 50 days of gestation was significantly (P less than 0.001) greater than that associated with examinations after 50 days of gestation. A significant difference was found between herds in different years (P less than 0.05). There was no conclusive indication that embryonic loss at the time of or shortly after early examination was iatrogenic abortion resulting from the membrane slip technique.

Animals↗
PubMed1979

Membrane changes during growth of Tetrahymena in the presence of ethanol.

After a brief lag period for acclimation, Tetrahymena pyriformis, strain NT-1, is capable of growing in culture medium containing high levels of ethanol. When grown in a medium having 1.6% ethanol, the membrane phospholipid composition was significantly different from that of control cells. The principal changes included a reduction in hexadecenoic acids (16 : 1 and 16 : 2) from 23% to 5% and an increase in linoleic acid (18 : 2) from 14% to 25% Similar but less pronounced changes were observed in cells grown in lower ethanol concentrations. There was also a decrease in 2-aminoethylphosphonolipid in the ethanol-grown cells from 16% of the lipid phosphorus to 6% and a coincident rise in the phosphatidylethanolamine from 39% to 46%. The lipid pattern quickly reverted to normal when ethanol was removed. In order to ascertain the effects of ethanol on membrane physical properties, freeze-fracture electron microsocopy and fluorescence polarization studies were performed. Ethanol, as expected, had a clearly detectable fluidizing influence when present at 1.6%. However, changes induced in the membrane lipids by growth in the ethanol-containing medium led to a further fluidizing effect, whether they were tested in the presence or absence of ethanol. The alterations found here were qualitatively similar but quantitatively much more pronounced than those observed in mammals chronically exposed to ethanol.

Cell Membrane↗
PubMed1979

Disopyramide-induced ventricular fibrillation.

Three cases are described with documented ventricular fibrillation shortly after the patients received disopyramide in moderate dosage. Electrocardiograms showed markedly prolonged Q-T intervals in two patients and a prominent U wave with a prolonged Q-U interval in one patient, but no change in QRS width. Disopyramide-induced ventricular fibrillation appears to be similar to that caused by quinidine and is an indication to discontinue the drug.

Administration, Oral↗
PubMed1979

Control of parturition in the sow using progesterone and prostaglandin.

The effect of progesterone and prostaglandin administration on the timing of farrowing was studied in three groups of 25 sows each. Progesterone treatment (100 mg/day) on days 112, 113 and 114 of gestation (group I) significantly prolonged the gestation length to 116.4 +/- 0.4 (mean +/- s.e.) days compared to the control sows (group III; 115.5 +/- 0.2; P less than 0.05). Administration of prostaglandin (200 micrograms Cloprostanol intramuscularly) on day 115 of gestation following progesterone treatment (group II) resulted in a gestation length of 116.0 +/- 0.1 days, with the sows farrowing 25.4 +/- 1.0 h after the prostaglandin injection. 80% of the sows farrowed between 0800 and 1700 h of day 116 of gestation. Plasma progesterone levels were maintained by the exogenous progesterone during treatment. At farrowing, higher levels of progesterone were observed in groups I and II compared to controls. Prostaglandin treatment did not significantly alter withdrawal of progesterone in progesterone treated sows, suggesting that the actions of exogenous prostaglandin is primarily on the myometrium and the cervix. Hormonal treatment in late pregnancy did not have any adverse effects on piglet viability and growth rate, or subsequent reproductive performances of sows. Lactation was initiated normally, and the concentrations of lactose, protein, fat, IgG, Na+, Ca2+ and K+ in colostrum and milk were similar in all groups during the first 5 days of lactation.

Animals↗
PubMed1979

Rheumatoid pericarditis. Clinical significance and operative management.

The incidence of subclinical pericarditis associated with rheumatoid pericarditis may be as high as 50 percent, but significant impairment of cardiac performance owing to this type of pericarditis rarely occurs. In the past 7 years, we have encountered eight men with congestive heart failure owing to rheumatoid pericarditis. Cardiac catheterization and echocardiography were useful in establishing the diagnosis of pericardial constriction. Pericardiocentesis was unsuccessful in relieving symptoms in the three patients in whom the procedure was performed. Seven patients underwent pericardiectomy; six had constrictive pericarditis and one patient had an acute pericarditis with the sudden onset of cardiac tamponade. The other patient died of cardiac tamponade prior to operation. All patients improved after operation and have remained free of cardiac symptoms 3 months to 4 1/2 years later. The frequent occurrence of adhesive and obliterative pericarditis with loculated effusions suggests the need for pericardiectomy rather than pericardiocentesis in the patient with rheumatoid arthritis and symptomatic pericardial involvement. Immediate and lasting relief of this unusual nonarticular manifestation of rheumatoid arthritis can be expected after pericardiectomy.

Adult↗
PubMed1978

Use of fluorescence polarization to monitor intracellular membrane changes during temperature acclimation. Correlation with lipid compositional and ultrastructural changes.

Fluorescence polarization of 1,6-diphenylhexatriene (DPH) was used to study the effects of temperature acclimation on Tetrahymena membranes. The physical properties of membrane lipids were found to be highly dependent on cellular growth temperature. DPH polarization in lipids from three different membrane fractions correlated well with earlier freeze-fracture and electron spin resonance observations showing that membrane fluidity progressively decreases in the order microsomes greater than pellicles greater than cilia throughout a wide range of growth temperatures. Changes in membrane lipid fluidity following a shift from high to low growth temperatures proceed rapidly in the microsomes, whereas there is a pronounced lag in the changes of peripheral cell membrane lipids. These data support previous observations that adaptive changes in membrane fluidity proceed via lipid modifications in the endoplasmic reticulum, followed by dissemination of lipid components to other cell membranes. The rapid changes in polarization observed in the microsomal lipids following a temperature shift correspond closely with the time-dependent alterations in both lipid fatty acid composition and freeze-fracture patterns of membrane particle distribution, suggesting that, in the endoplasmic reticulum, lipid phase separation is the primary cause of membrane particle rearrangements.

Animals↗
PubMed1978

Rotational relaxation of 1,6-diphenylhexatriene in membrane lipids of cells acclimated to high and low growth temperatures.

Measurement of the time-resolved fluorescence depolarization of 1,6-diphenylhexatriene (DPH) in artificial bilayers of microsomal membrane lipids from Tetrahymena gives detailed information concerning the molecular motion of this probe and fluid properties of the membrane lipids which are obscured with steady-state methods. The rotational motion of DPH in these lipids from cells acclimated to 15 and 39.5 degrees C growth temperatures was anisotropic, which agrees with recent time-resolved studies of this probe in synthetic phospholipid systems. Evaluation of DPH polarization data obtained from these lipid fractions at their respective growth temperatures showed differences in physical properties which suggest that "viscosity", per se, of the microsomal lipids is not a strictly regulated as it is in prokaryotic systems. Rotational relaxation of DPH in 39.5 degrees C microsomal lipids measured at 15 degrees C is more complex than that of either lipid fraction measured at its actual growth temperature, suggesting that the probe has partitioned into two dissimilar environments within the bilayer. Similar effects are observed in the microsomes of 39.5 degrees C cells by freeze-fracture electron microscopy following rapid cooling to 15 degrees C. Under these conditions, two distinct regions are observed on the fracture faces, suggesting a correlation between lipid phase changes and alterations in membrane structure.

Acclimatization↗
PubMed1978

Progesterone and corticosteroids in the initiation of lactation in the sow.

The concentration of lactose in the mammary secretion from individual glands of two sows increased significantly (P less than 0.01) between 0 and 24 h after parturition. In six sows studied during the perinatal period there was a negative correlation (r = -0.80; P less than 0.02) at parturition between the concentration of progesterone in the blood and the concentration of lactose in the mammary secretion. Furthermore, the increase in concentration of lactose in the mammary secretion after parturition was related to the timing of the decline of plasma progesterone to low levels. The results indicate that the initiation of lactation occurs within 24 h of parturition in most sows, and the results are consistent with the hypothesis that progesterone withdrawal acts as the 'trigger'. Neither the changes in corticosteroid binding globulin nor the changes in total corticosteroids were temporally related to the initiation of lactation. However, a circadian rhythm was observed for total corticosteroids in the blood of three out of nine lactating and pregnant sows, whereas no circadian rhythm was observed in progesterone of the four pregnant sows. The results are discussed in relation to the disease complex mastitis-metritis-agalactia.

Adrenal Cortex Hormones↗
PubMed1977

Sexual daydreams and quantitative aspects of sexual activity: some relations for males across adulthood.

Sexual daydreams were measured using the Imaginal Processes Inventory, while retrospective data on number of coital partners, frequency of intercourse in early marriage, and quantity of sexual activity experienced between 20 and 40 years of age were obtained by interview. The 277 men studied ranged from 24 to 91 years. The frequency and intensity of sexual daydreams declined with increasing age, and after age 65 virtually disappeared. The occurrence of sexual daydreams varied directly with each of the three behavioral indicators of sexual vigor for all age groups through age 64. The results are seen as supportive of the "current concerns" explanation of daydreaming production.

Adult↗
PubMed1977

Candida albicans infection of sternum and costal cartilages: combined operative treatment and drug therapy and 5-fluorocytosine.

Two patients with candidal sternal osteomyelitis have been successfully treated by operative debridement and adjuvant drug therapy with 5-fluorocytosine. One patient had developed postoperative candidal wound infection after sternotomy, and the other acquired candidal sternal osteomyelitis following Candida fungemia. The diagnosis, suggested by culture, was confirmed by identification of Candida pseudohyphae in debrided tissue. Histological confirmation of candidal sternal osteomyelitis indicates the need for operative debridement and specific systemic antifungal therapy. The drug 5-fluorocytosine appears to provide effective oral therapy in this situation.

Candidiasis↗
PubMed1977

Echocardiographic diagnosis of intraventricular clot.

The literature contains many reports of the echocardiographic findings in left atrial myxoma and clot; however, descriptions of left ventricular thrombus or tumor are rare. We discuss here the echocardiographic findings in a patient with a large apical left ventricular thrombus which was confirmed both angiographically and pathologically. The importance of echocardiographically examining the area below the mitral valve near the apex of the left ventricle, where most of the thrombi are located, is stressed.

Diagnosis, Differential↗
PubMed1976

Molecular control of membrane properties during temperature acclimation. Fatty acid desaturase regulation of membrane fluidity in acclimating Tetrahymena cells.

This is a study of the molecular mechanisms employed by Tetrahymena pyriformis to change the lipid composition and thereby the fluidity of its various membranes during temperature acclimation. By quantitatively measuring the intramembrane particle aggregation using freeze-fracture electron microscopy, membrane physical properties in 39.5 degrees C grown cells shifted to 15 degrees C were found to be correlated with the degree of phospholipid fatty acid desaturation. Alteration of the phospholipid polar head group distribution from that of 39.5 degrees C-grown cells to the significantly different pattern of 15 degrees C grown cells appeared not to be of critical importance in the acclimation process. Changes in fatty acid desaturation during acclimation from high to low temperatures and vice versa were analyzed using normal cells and cells fed large amounts of polyunsaturated fatty acids. Fatty acid desaturase activity corresponded to the degree of membrane fluidity but not to the cell temperature. All evidence was compatible with the hypothesis that membrane fluidity is self-regulating, with the action of fatty acid desaturases being modulated by the physical state of their membrane environment.

Acetates↗
PubMed1976

Molecular control of membrane properties during temperature acclimation. Membrane fluidity regulation of fatty acid desaturase action?

Further studies on the molecular mechanisms of temperature acclimation have been carried out using the ciliate Tetrahymena pyriformis. The most prominent change in lipid metabolism during acclimation to high temperature--depression of fatty acid desaturase activity--could be simulated by supplementing the growth medium of isothermally-grown cells with polyunsaturated fatty acids. Such cells resisted the membrane-fluidizing effect of the incorporated exogenous acids by increased use of de novo synthesized saturated acids in their phospholipids. The data support the conclusions arising from earlier experiments with temperature-shifted cells (Martin, C.E., Hiramitsu, K., Kitajima, Y., Nozawa, Y., Skriver, L., and Thompson, G.A., Jr. (1976), Biochemistry 15), showing that, when membrane fluidity increased to a superoptimal level, the activity of membrane-associated fatty acid desaturases was decreased. Since the reaction is controlled by membrane fluidity, rather than temperature per se, we postulate that it is the general mechnaism employed by cells adjusting to any fluidity-modifying factor, such as cations, drugs, etc.

Adaptation, Physiological↗
PubMed1976

Changes in membrane lipid composition during temperature adaptation by a thermotolerant strain of Tetrahymena pyriformis.

Experiments on temperature adaptation have been conducted using a thermotolerant clone of Tetrahymena pyriformis designated as strain NT-1. The strain was able to grow well at 39.5 and 15 degrees C and could adapt quickly when transferred from one of these temperatures to the other. Cells grown at the extreme temperatures differed markedly in their membrane lipid composition, particularly in the phospholipid polar head groups and hydrocarbon chains. The levels of fatty acid unsaturation increased at the lower temperature (e.g. 15 degrees C cells contained 31% gamma-linolenic acid vs. 25% at 39.5 degrees C) as did the content of alkyl glyceryl ether derivatives. Ethanolamine phosphoglycerides decreased by more than 10 mol % of the lipid phosphorus with the drop in temperature, the decrease being offset by a concomitant rise in 2-aminoethylphosphonolipid. These temperature-induced changes were noted in certain purified membrane preparations as well as in whole cells. Experiments with [14C]palmitic acid and sodium[14C]acetate showed that fatty acids are first incorporated into phospholipids predominantly in a saturated form. The membranes served as a reservoir of fatty acid substrate for desaturase activity. Tetrahymena pyriformis, strain NT-1, was proposed as a useful model system for studying the temperature adaptation process in eukaryotic cells.

Acclimatization↗
PubMed1976

Preferential atherosclerosis at the aortic junction of the ligamentum arteriosum: clinical significance and pathological correlation.

Clinical experience with 5 patients who had complications of atherosclerosis within the aorta at the site of the obliterated ductus arteriosus suggested the occurrence of clinically significant preferential atherosclerosis at this location. To examine this hypothesis, the clinical findings in these patients (4 with saccular aneurysm and 1 with systemic emboli from an ulcerated plaque at this location) were correlated with postmortem examination of the aortic isthmus in 40 consecutive cadavers. The point of ductal closure was the area of most severe atheromatous involvement in 32 of the 40 cadavers, and 25 of the 40 specimens demonstrated ulcerated plaques at this location. Microscopical examination consistently demonstrated intimal irregularity or disruption and thinning of the aortic media in this area. These studies indicate that preferential atherosclerosis occurs at the aortic end of the obliterated ducts arteriosus and that these atherosclerotic changes can be a clinically significant development.

Adult↗