Biomedical subjects

T Salerno

Publications and source records attributed to T Salerno.

8 recordsLinked to original sources

PubMed1991

Not all neonatal hearts are equally protected from ischemic damage during hypothermia.

Despite hypothermia, pediatric cardiac surgeons continue to experience difficulties in providing adequate myocardial protection in newborns. This study examines the effects of deep hypothermia on neonatal heart tolerance to ischemia by measuring metabolic responses and the time to onset of ischemic contracture, or "stone heart." After control right ventricular biopsy specimens were obtained, hearts of newborn pigs (n = 36) were excised and placed in temperature-regulated baths: 37.5 degrees +/- 0.5 degrees C (n = 9), 19.0 degrees +/- 0.5 degrees C (n = 14), and 12.0 degrees +/- 0.5 degrees C (n = 13). With a compliant balloon in the left ventricle to measure pressure, time to onset of ischemic contracture (greater than 2-mm Hg rise) was recorded, and sequential biopsies were done. Data indicated hypothermia significantly (p less than 0.001) prolonged time to onset of ischemic contracture from 29.5 +/- 1.7 minutes (mean +/- standard error of the mean) at normothermia to 150.0 +/- 6.4 minutes at 19 degrees C and to 283.8 +/- 46.4 minutes at 12 degrees C. Lactate buildup at 30 minutes of ischemia was significantly reduced by 70% with hypothermia. Decline in adenosine triphosphate level was significantly reduced by 50% (19 degrees C) and 75% (12 degrees C) with hypothermia. More importantly, a subgroup of hearts in each hypothermia group (n = 5 per group) was identified by 38% to 48% lower adenosine triphosphate stores before ischemia compared with the group means.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenosine Triphosphate↗

PubMed1991

Myocardial biochemical and hemodynamic adaptations to chronic tachycardia.

The purpose was to determine the biochemical and hemodynamic adaptations of the myocardium to chronic tachycardia. Cardiac pacemakers were implanted in Yorkshire pigs and set at a rate of 180 beats/min for a period of 35-42 days. Animals were then anesthetized with pentobarbital sodium. Myocardial blood flow and hemodynamics were determined at three different heart rates (i.e., 120, 180, and 220 beats/min). Tissue samples were then taken for microsphere and biochemical analyses. Chronically paced hearts maintained better cardiac function and had consistently higher left ventricular blood flow with a higher endocardial-to-epicardial ratio. The activities of citrate synthase and 3-hydroxyacyl-CoA dehydrogenase were 23 and 45% greater in the paced hearts, respectively. The sarcoplasmic reticulum adenosinetriphosphatase activity was 55% greater in the paced hearts, whereas the myosin adenosinetriphosphatase was the same as in the control hearts. Polyacrylamide gels of the ventricular myosin isoforms showed only the V3 type to be present in both the control and paced hearts. These findings show that the heart of a large mammal adapts to chronic tachycardia (i.e., 180 beats/min) by elevating the aerobic and calcium-sequestering capacities without altering its myosin type.

3-Hydroxyacyl CoA Dehydrogenases↗

PubMed1989

Valvular surgery in the elderly.

In previous studies from this university, advanced age was identified as an independent predictor of operative mortality for valvular surgery. Therefore, between January 1982 and December 1986, early results were compared in 469 patients greater than 70 years old (Old; 74.0 +/- 3.4 years, mean +/- SD) and in 2,040 patients less than 70 years old (Young; 53.7 +/- 12.1 years). Patients underwent single- or multiple-valve repair or replacement with or without concomitant coronary artery bypass surgery. Data consisting of 31 clinical and angiographic variables were collected prospectively and were analyzed by univariate and multivariate statistics. Old patients were characterized by having more frequent left ventricular dysfunction (left ventricular ejection fraction less than 40%: Old, 33.5%; Young, 22.4%; p less than 0.001), coronary artery disease (Old, 54.5%; Young, 24.2%; p less than 0.001), and urgent surgery (Old, 15.6%; Young, 11.8%; p = 0.02). Aortic valve procedures (Old, 59.7%; Young, 40.1%; p less than 0.001) and concomitant coronary artery bypass surgery (Old, 46.4%; Young, 20.3%; p less than 0.001) were performed more commonly in the Old patient. Operative mortality occurred in 10.0% of Old patients compared with 5.6% of Young patients (p less than 0.001), and major morbidity (low-output syndrome, perioperative myocardial infarction, intra-aortic balloon pump counterpulsation, and stroke) occurred significantly more frequently (p less than 0.001) in the Old. Stepwise logistic regression identified that urgent operation (p = 0.002), mitral or double-valve surgery (p = 0.004), coronary artery disease especially when not treated by bypass surgery (p = 0.02), female gender (p = 0.02), and left ventricular dysfunction (p = 0.05) independently predicted operative death in the Old population. The significant predictors of mortality in the Young patient were urgent operation (p less than 0.001), New York Heart Association class IV (p less than 0.001), associated tricuspid valve disease (p = 0.002), decreased left ventricular function (p = 0.01), valvular re-replacement (p = 0.02), and increasing age (p = 0.03). The predicted probability of operative mortality in Old patients ranged between 0.9 +/- 0.5% and 76 +/- 16%. Elderly patients in good risk categories should be offered surgical intervention for correction of valvular lesions. Alternative therapy may be indicated in patients with multiple risk factors.

Age Factors↗

PubMed1988

Effects of different thyroid treatments on the biochemical characteristics of rabbit myocardium.

It is well established that extreme dysthyroidism drastically alters the biochemical character of cardiac muscle. The purpose of this study was to determine if minor thyroid treatments would result in significant changes in the character of three major biochemical systems of muscle: metabolic; calcium regulating; and contractile systems. Different groups of New Zealand white rabbits had continuous time release propylthiouracil (PTU) pellets (500, 300, 200 and 100 mg) or triiodothyronine (T3) pellets (15 and 25 mg) subcutaneously implanted for 21 days. The ventricular myosin phenotypes shifted from 92% V3 myosin in the control rabbit hearts to 55% V3 and 10% V3 in the 15 mg and 25 mg T3 groups, respectively. PTU treatment resulted in a complete shift to the V3 myosin isoform. The sarcoplasmic reticulum Ca2+-ATPase activity increased with T3 and decreased with PTU treatments, except in the 500 mg PTU group. Ca2+-ATPase activity in the groups either side of the euthyroid group (100 mg PTU and 15 mg T3) did not change significantly. The glycolytic or aerobic potentials of the myocardium did not change with any of these minor thyroid treatments. It was concluded that the metabolic, enzymes, sarcoplasmic reticulum Ca2+-ATPase and myosin isozymes have different sensitivities to thyroid treatment and that minor thyroid treatments do result in significant changes in the biochemical character of the myocardium. These findings indicate that subclinical deviations in euthyroid status may affect myocardial biochemical character.

Animals↗

PubMed1978

Management of extremity with combined neurovascular and musculoskeletal trauma.

Twenty-five civilians with combined neurovascular and musculo-skeletal trauma to 27 extremities were studied retrospectively. The mechanism of injury was crushing in 16, avulstion in six, and penetrating in three. Autogenous saphenous vein was used to restore arterial circulation in the majority. Nine patients had concurrent repair of venous injuries. Fractures were immobilized by a variety of techniques, the Hoffman external skeletal fixation being preferred. Immediate fasciotomy was performed in five patients and delayed fasciotomy in four. All patients had soft-tissue debridement and initial wound closure with split-skin grafts as biologic dressings. Three immediate amputations were the result of irreversible neurovascular and soft-tissue trauma. Sepsis played a role in three late amputations; delayed primary treatment,, irreversible neurologic injuries and extensive soft-tissue damage contributed. A carefully individualized multidisciplinary approach resulted in salvage of 20 of 27 severely injured extremities.

Adolescent↗

PubMed1978

In vitro translation of the Two RNAs of Nodamura virus, a novel mammalian virus with a divided genome.

Nodamura virus is a small ribovirus containing two RNA molecules. Both RNAs were found to be active messengers for protein synthesis in cell-free extracts prepared from wheat embryo or HeLa cells. RNA 2 directed synthesis of a 43,000-dalton product, p43, whose tryptic fingerprint was similar to that of the major viral coat protein, vp40 (molecular weight, 40,000). Though p43 appears to be a precursor of vp40, processing did not occur in the cell-free extracts. RNA 1 directed synthesis of a 105,000-dalton protein, p105. Its tryptic fingerprint revealed no evidence of coat protein sequences. Hence, the two RNAs represent genes with few, if any, redundant coding sequences.

Amino Acids↗

PubMed1971

An infected toe.

Explore the source record for details and available documents.

Attitude of Health Personnel↗

PubMedDate not supplied

Compensatory adaptation of the heart to chronic rate overload: increase in calcium transport ATPase activity of myocardial sarcoplasmic reticulum.

This study was undertaken to test the hypothesis that a compensatory response of the heart to a chronic and continuous, metabolic and heart rate overload was an increase in the calcium sequestering activity of the myocardial sarcoplasmic reticulum. Calcium sequestering activity was estimated by determination of the calcium-dependent ATPase (Ca2+-ATPase) activity of isolated microsomes. Chronic rate overload was modelled by comparing: dysthyroid and control rats; control swine and swine with implanted cardiac pacemakers set at 180 beats/min; and different species of mammals with widely different heart rates. The myocardial sarcoplasmic reticulum Ca2+-ATPase pump activity was significantly increased by 39% for hyperthyroid rats compared to control rats and by 87% for control rats compared to thyroidectomized rats; by 63% for paced swine compared to control swine; and by 43% for rats compared to guinea pigs, by 140% for guinea pigs compared to dogs and by 120% for dogs compared to cows. These data indicate that calcium sequestering activity of myocardial sarcoplasmic reticulum increases in equivalent proportion to the chronotropic demand and that heart rate is a hemodynamic correlate of the sarcoplasmic reticulum Ca2+-ATPase activity.

Adaptation, Physiological↗