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Biomedical subjects

R Martin

Publications and source records attributed to R Martin.

At least 703 records · Page 39Linked to original sources
PubMed1976

The interaction of the lung and chest wall in dogs.

The deformation of the lung by the chest wall was observed on radiographs of the ribs and interspaces and on morphologic preparations of samples cut from the frozen thorax. The effect of these deformities on the distribution of ventilation and regional lung volume of the underlying lung was determined using Xenon 133. We found that ribs and interspaces deform the lung surface with different radii of curvature, suggesting local differences in pleural pressure and that traction on the thoracic limb caused deformities in the underlying interspaces which were similar to those produced by 20 cm H2O mouth pressure. Xenon 133 showed that these changes in pressure had no effect on the regional volume or on ventilation distribution in the underlying lung. We conclude that changes in pleural pressure produced by localized deformities exert their effect close to the deformity and that the underlying lung responds to the average pressure exerted over a much larger area of the pleural surface.

Airway Resistance↗
PubMed1976

Massive intracerebellar hemorrhage in low-birth-weight infants.

The clinical and pathologic observations of massive intracerebellar hemorrhage (destruction of at least one-third of cerebellar tissue) are described in six low-birth-weight infants. In all infants, severe progressive apnea associated with a falling hematocrit were the prominent clinical features. Four infants were asphyxiated at birth. Some degree of cerebellar hemorrhage (macroscopic or microscopic) was observed in 21% of 157 newborn brains examined at autopsy. The cause of massive intracerebellar hemorrhage is unknown, but may result from deforming pressures on the skull secondary to perinatal trauma. A close follow-up of cerebellar function in low-birth-weight infants is important.

Birth Weight↗
PubMed1976

Effect of adrenalectomy on weight gain and body composition of yellow obese mice (Ay/a).

It has been reported that the adrenal gland is essential to the development of obesity if Ay/a Yellow obese mice (Hausberger and Hausberger 1960). Since the actual body composition data to support this report has not been published, we attempted to duplicate this observation by adrenalectomy of the Yellow mice before the onset of obesity. Two groups of Yellow mice (Ay/a) and normal mice (a/a) were either sham operated or adrenalectomized at two months of age and at four months of age. Body weight was monitored until body gain had stopped. At that time the animals were sacrified and checked for completeness of adrenal removal. Body composition of dry matter, fat, protein, and ash was determined. Adrenalectomy caused a reduction of body fat of 33% and 30% in both the a/a Control and the Ay/a Yellow mice, respectively. The adrenalectomized Yellow mice were still fatter than adrenalectomized Controls (25.3% fat vs. 10.6% fat). Yellow and control adrenalectomized mice showed similar depression in growth rate. These data suggest that while the adrenal gland is essential for complete expression of the genetic potential for fat deposition, it may not be necessary for partial expression indicating a secondary role in the development of obesity in the Ay/a Yellow mouse.

Adrenal Glands↗
PubMed1976

Nuclear origin of specific yeast mitochondrial aminoacyl-tRNA synthetases.

Hydroxylapatite chromatographies of mitochondrial and total enzymes from a rho+ yeast, or from the related rho degrees mitochondrial DNA-less mutant, show the occurrence in the mitochondrial enzyme of one Phe-, one Met-, one Leu-tRNA synthetase peak which elutes distinctly from the cytoplasmic counterpart and charges well mitochondrial tRNA, whereas the cytoplasmic enzyme does not. The measurement of the mitochondrial synthetases activities in various enzymatic extracts shows that they are not repressed in rho+ cells grown on 10% glucose and that they are concentrated in the mitochondria (Phe- and Met- tRNA synthetases) but are also present outside the mitochondria. It is concluded that yeast mitochondrial protein biosynthesis involves the nuclear coded mitochondrial specific Phe-, Met- and Leu-tRNA synthetases and that the entrance of the synthetases into the mitochondria needs no factor depending on the mitochondrial DNA.

Amino Acyl-tRNA Synthetases↗
PubMed1976

The relationship between symptoms and functional abnormalities in clinically healthy cigarette smokers.

Because a number of "early tests" may now be used to measure abnormalities of lung function in cigarette smokers with normal airflow rates, we evaluated the symptoms of cough, sputum, wheezing, and shortness of breath in 60 nonsmokers and 49 smokers to determine whether these symptoms correlated with measurements of lung function that are believed to be altered by mild obstruction. One or more symptoms were present in 5 per cent of the nonsmokers and 90 per cent of the smokers. Individual symptoms, sums of symptoms (symptoms score), and various combinations of symptoms correlated poorly or not at all to measured values for dynamic lung compliance, closing volume, closing capacity, slope of Phase III, and helium flow-volume curves. The symptoms score correlated negatively (P less than 0.05) with forced maximal expiratory flow at 50 per cent of vital capacity. Inasmuch as the serious consequences of chronic airway obstruction are related to abnormalities of lung function, it is likely the function tests will prove more useful than symptoms to reveal smokers at risk to develop chronic obstructive pulmonary disease. Symptoms cannot be used to detect smokers who are liable to have functional abnormalities suggestive of mild peripheral airway obstruction.

Adult↗
PubMed1976

Perichondritis of the ear.

A total of five ears with perichondritis secondary to burns was treated using a method of excising cartilage. This treatment resulted in the need for general anesthesia, frequent repeat debridement and frequent loss of structure of the ear with subsequent deformity. The presentation, etiology, pathology and present modes of therapy are presented. Our experience stresses the importance of early recognition and treatment and further consideration for the use of drains with continuous antibiotic and proteolytic enzyme administration.

Adult↗
PubMed1976

The characterization of intima development in left ventricular assist device (LVAD) and total artificial heart (TAH).

1. The study of PNI development provides useful information in the design and improvement of the prosthetic devices. 2. Improved gelatin aldehyde impregnation on the dacron covered diaphragm of cardiac prostheses resulted in a reduced PNI thickness and minimized interfacial degeneration of PNI. 3. The PNI on the diaphragm's surface started with a platelet rich interface and ended with a striated fibrin and platelet matrix at the blood interface. 4. The PNI in the TAH's had a higher involvement of polymorphonuclear leukocytic cells at the PNI-housing or diaphragm interface than the LVAD's. 5. The aldehyde treated pericardial surface of cardiac prostheses generated a thin PNI that was fibrin-rich, a viable cell infiltration, no interfacial degeneration, and endothelial-like cells on its surface.

Aldehydes↗