Search PubMed⌕ Search

Biomedical subjects

C E Martin

Publications and source records attributed to C E Martin.

At least 91 records · Page 5Linked to original sources
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↗
PubMed1976

Selective operative treatment for tetraology of Fallot: rationale and results.

Eighty-one patients with tetralogy of Fallot malformations evaluated between July 1, 1971 and November, 1975 are presented. Fifty-one patients underwent primary intracardiac repair; three died. Twenty-seven patients were corrected after a previous palliative shunt; there was one death. Three additional patients have been palliated and are awaiting repair. While the overall mortality in these patients was less than 5%, the infants undergoing total correction before the age of two years appeared to be at greater risk (25%). There were no deaths in the group of patients undergoing palliative procedures. Based on these data it appears that a safely performed palliative shunt in the symptomatic small infant is a reasonable first step, particularly if the outflow tract of the right ventricle is diffusely hypoplastic.

Adolescent↗
PubMed1976

Femoropopliteal bypass for salvage and claudication: a comparison of long-term results.

Seventy-seven femoropopliteal grafts placed for salvage were compared to 51 grafts placed for claudication. Patient profiles of age, preexisting cardiovascular disease, and risk factors were notably similar. Previous vascular procedures were twice as common in the salvage group. The accumulated graft patency in the salvage group of 77% at one month and 58% at two years is compared to 90% and 80% during the same risk intervals in the claudication group. The salvage group sustained 34 complications (44%) and nine deaths (12%), compared to one death (2%) and seven complications (14%) in the claudication group. One half of all grafts placed in diabetic males failed. Nearly half of all early failures were thought to be due to errors of patient selection. Though new technics are making more extremities potentially salvageable, this study suggests that improved patient selection will be necessary to lower high complication rates.

Amputation, Surgical↗
PubMed1976

Ostium primum atrial septal defect in the adult.

Seven adults with ostium primum atrial septal defect (ASD) are presented. All but one patient were symptomatic at the time of diagnosis with the average age being 41 years. At catheterization each had a large, low ASD, left-to-right shunt, and a cleft mitral valve leaflet with minimal regurgitation. Pulmonary hypertension occurred in one. Six patients are asymptomatic an average of 3.5 years after surgical correction. One patient died of other causes at 18 months. Rapid decompensation secondary to arrhythmias or atrioventricular block occurs much more frequently with primum than with secundum ASDs, approaching 80% by age 45. Follow-up in this series suggests that surgical correction may prevent these developments.

Adult↗
PubMed1976

Serial measurement of arterial plasma progesterone levels throughout gestation and parturition in individual rats.

Daily blood samples were taken from 6, chronically cannulated, fully conscious rats to measure plasma progesterone levels throughout gestation. Progesterone levels in individual rats fluctuated by up to 28 ng/ml per day, but tended to be consistently higher or lower than the group mean. The accuracy of predicting progesterone levels in individual rats from previous values was examined. Progesterone levels on day 7 of gestation were negatively correlated with foetal weights near term. There was little indication that high progesterone levels at any stage of gestation lead to increased foetal or placental weights. Progesterone levels on day 17 were positively correlated with the number of corpura lutea but there was little relationship between progesterone and either the number or total mass of the placentas. Serial blood samples taken from a second group of 6 rats at 2 hourly intervals showed that the time between the major fall in progesterone levels to below 12 ng/ml and the onset of parturition was relatively constant (varying by only 8 h) despite a 29 h range in the total length of gestation.

Animals↗
PubMed1976

Multiple gastrointestinal atresias, with intraluminal calcifications and cystic dilatation of bile ducts: a newly recognized entity resemblin "a string of pearls".

The siblings reported here represent a new and complex congential anomaly. A genetic basis is strongly suggested. The natural preparation of closed loop duodenal obstruction and cystic dilatation of the bile ducts is a unique finding. The hallmark of this new entity--intraluminal calcifications strung out through small and large intestine like pearls--is a striking radiographic feature and, in the proper clinical setting, pathognomonic. This entity has been uniformly lethal. Once the diagnosis is confirmed, no known therapy is useful.

Abnormalities, Multiple↗
PubMed1975

Peroneal nerve paralysis in a heifer.

Peroneal nerve paralysis in a heifer developed during an 11-day period of recumbency following dystocia. The condition did not improve during the next 42 days and the heifer was slaughtered. On the basis of microscopic findings, it was concluded that 3 to 4 months would have been required to reestablish normal limb function.

Animals↗
PubMed1975

Temperature-sensitive, osmotic-remedial mutants of Neurospora crassa: osmotic pressure induced alterations of enzyme stability.

Three temperature-sensitive, adenine-requiring mutants of Neurospora crassa were found to be osmotic-remedial when non-penetrating solutes were used to increase the osmolarity of the growth medium. The affected enzyme (adenylosuccinase) from one of the mutants (ad-4, 44206t) was found to have higher levels of activity when the organism was grown at non-permissive temperatures under osmotic-remedial conditions than when it was grown with adenine as a nutritional supplement. The enzyme synthesized at 30 degrees C in the presence of adenine exhibited increased sensitivity to inhibition by high salt concentrations and a lowered stability toward heat denaturation, indicating that the remedial effect may be the result of changes in the physical properties of the enzyme molecule. Temperature shift experiments indicate that the enzyme which is synthesized at permissive temperatures or under osmotic-remedial conditions is also stable in vivo under non-permissive conditions. This suggests that the critical period for temperature sensitivity, and conversely osmotic remediability, may be during protein synthesis or during the conformational folding of the protein.

Adenine↗
PubMed1975

Major hepatic resections in children.

Twenty-three major hepatic resections in children are presented. An unusually low number of associated injuries is noted in the trauma group. There was one operative death and complications were limited to five patients. Biliary decompression was not employed. Complications did not include respiratory, renal, or hepatic failure. Gastrointestinal bleeding was not seen. Although debridement seems adequate for subsegmental injuries, anatomic lobectomy must be considered for more severe injuries involving multiple segments of a single lobe.

Adolescent↗
PubMed1975

Management of pancreatic ascites.

Two patients with persistent pancreatic ascites are presented. Both were managed successfully by internal drainage. A trial of nonoperative treatment with nasogastric intubation and intravenous hyperalimentation is advocated for patients with pancreatic ascites. Patients who fail to improve usually have a pancreatic duct disruption and should have internal drainage operation and/or distal pancreatic resection.

Adult↗
PubMed1975

Two forms of a mitochondrial endonuclease in Neurospora crassa.

Mitochondrial nuclease activity in Neurospora crassa occurs in membrane-bound and soluble forms in approximately equal proportions. These activities apparently are due to the same enzyme, which has an approximate molecular weight of 120 000. A portion of the insoluble enzyme appears to be associated with the inner mitochondrial membrane and is resistant to solubilization by detergent treatment as well as by physical disruption methods.

Cytochrome Reductases↗
PubMed1975

Cordycepin inhibition of 3-methylcholanthrene-induced transformation in vitro.

Cordycepin (3-deoxyadenosine), an inhibitor of poly (a) synthesis, was found to inhibit the induction of the endogenous type "C" RNA virus by 5-iodo-2'-deoxyuridine in a line of Fisher rat embryo cells (H43) grown in vitro, and when continuously incorporated into the medium at those same concentrations, it was found to protect the cells from transformation by the chemical carcinogen 3-methylcholanthrene.

Cell Line↗
PubMed1974

Autonomic mechanisms in hemodynamic responses to isometric exercise.

Selective autonomic blockade with intravenous propranolol, practolol, atropine, and combined atropine-propranolol was utilized to elucidate the role of the autonomic nervous system in the hemodynamic responses in young adult male volunteers to handgrip sustained at 30% of maximal voluntary contraction for 3 min. The initial 30 s of the tachycardia response was found to be mediated by withdrawal of vagal dominance, as evidenced by blockade of this response by prior atropinization. The mid and late portion of the heart rate response curve was demonstrated to be sympathetic in origin, since it was unaffected by atropine, but was suppressed by combined atropine-propranolol blockade. Sympathetic stimulation appears to be a secondary mechanism for increasing the heart rate, however, as it becomes operative only after the first mechanism of vagal withdrawal has been utilized. This was confirmed by the finding that beta adrenergic receptor blockade alone had little effect on the heart rate response curve. The pressor response to handgrip was accompanied by increased cardiac output and no change in calculated systemic vascular resistance. After propranolol, handgrip resulted in increased peripheral resistance and an equivalent rise in arterial pressure, but no increase in cardiac output. It was concluded that the increase in resistance was the result of sympathetically induced vasoconstriction. This response was shown to be independent of peripheral beta adrenergic receptor blockade by the use of practolol, a cardio-selective beta adrenergic receptor-blocking drug which caused identical hemodynamic responses to those observed after propranolol. Left ventricular ejection time (corrected for heart rate) was prolonged by handgrip. The increased afterload imposed on the left ventricle by sustained handgrip may explain the prolongation of ejection time index. Preejection period was prolonged by SHG after propranolol and shortened after atropine. In addition to confirming the previously defined role of the parasympathetic nervous system, this study delineates the role of the sympathetic nervous system in the heart rate and pressor responses to sustained handgrip.

Adult↗