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Biomedical subjects

N Gootman

Publications and source records attributed to N Gootman.

At least 37 records · Page 2Linked to original sources

Comparative effects of bicarbonate and dichloroacetate in newborn swine with hypoxic lactic acidosis.

UNLABELLED: Sodium bicarbonate (BC) and dichloroacetate (DCA) were studied in 7- to 14-day-old (n = 25) anesthetized swine with hypoxic acidosis. BC (base deficit X kg X 0.3, n = 10), DCA (300 mg/kg, n = 7) or saline (n = 8) was infused for 1 h. Blood lactic acid, dP/dtmax, heart rate and cardiac output increased and base excess and total arterial and carotid resistances (R) decreased with acidosis; aortic pressure, renal and mesenteric R did not change. BC induced higher pH, base excess and lactic acid. Heart rate in all and dP/dtmax with BC and DCA were restored; renal and mesenteric R and aortic pressure decreased in all. Cardiovascular responses to DCA and BC did not differ except for renal R. CONCLUSION: BC is a more effective alkalizer than DCA, which induced a greater renal vasodilation; both restored contractility.

Acidosis, Lactic↗

Unusual observations on hypermagnesemic levels and cardiorespiratory effects in neonatal swine.

Mg is being used as a therapeutic agent in different clinical conditions, i.e. preeclampsia or eclampsia, and as a tocolytic agent to prevent premature delivery. For these reasons we decided to systematically investigate the cardiovascular and respiratory effects of excess Mg in 25 piglets less than 1 day to 3 months of age, lightly anesthetized with Saffan, tracheotomized, paralyzed with C-10 and artificially ventilated on 100% O2. A 1.0 M infusion of MgCl2 was given for 15-60 min, and arterial plasma samples were drawn before and at the end of the infusion for the determination of plasma Mg and Ca levels. Phrenic nerve activity was recorded monophasically simultaneously with arterial blood pressure, electrocardiogram, end-tidal CO2 and intratracheal pressure on a dynograph and on analog tape. In a subset of experiments (n = 6), spontaneous ventilation was monitored in piglets of different ages to determine the Mg concentration at which spontaneous ventilation ceased. Blood gases were measured at 45-min intervals, as well as both immediately before and after the MgCl2 infusion, and pCO2 and pH were maintained within normal limits. As a consequence of the high plasma concentration of Mg, mean arterial pressure and heart rate declined, and the inspiratory duration significantly decreased. Our results indicate that young piglets can survive high levels of plasma Mg (greater than 14 mM).

Animals↗

Bilateral origin of the left anterior descending coronary artery in a young man.

Abnormalities of coronary artery origin from the aorta have been implicated in sudden death in sports among young athletes. We describe an 18-year-old patient who presented with nonspecific chest pain, developed ventricular couplets during recovery from a stress test, and whose coronary angiograms revealed bilateral left anterior descending coronary arteries, an abnormality that has not been previously reported.

Adolescent↗

Young long distance runners. Physiological and psychological characteristics.

This study presents the physiological and psychological characteristics and the running histories of 16 subjects who began long distance running at age 4-12 years. Running duration was 3-15 years (mean 8.4 +/- 3.6 yrs). Seven children completed 41 marathons, seven 30-mile races, and eight 60-mile races. The other nine competed at shorter distances. All trained at 30-105 miles/week. Two stress fractures, one back sprain and one knee injury occurred. Athletes who reported injuries from recollection may have underreported some injuries. At age 15.4 +/- 4.2 years bone age was 15.3 +/- 2.6 years and height was at 51 +/- 26.0 percentile. Athletes had larger left ventricular diastolic diameter, higher max O2 uptake, and delayed onset of anaerobic metabolism compared to controls. Psychological profile: IQ = 121 +/- 11, scholastic grade point average (GPA) (n = 13) was less than or equal to 3.0 in four, 3.6-3.9 in four, and 4.0 in five. Cattell 16 personality factor (PF): Seven scored above the 85th percentile on boldness, warmth, conformity, sensitivity, dominance, and high drive with tension. Eight scored above the 93rd percentile for self discipline and emotional stability. Human Figure Drawing showed a distorted body image in seven. Two developed anorexia nervosa, and another girl committed suicide. Thus, high physical fitness and no growth retardation were observed. These runners, however, shared distinct positive and negative personality characteristics. The relatively high incidence of severe psychological disorders possibly suggests a need for psychological screening for young children entering a strenuous training program and for close monitoring for development of psychological problems during the program.

Adolescent↗

Chest pain, dyspnea on exertion, and exercise induced asthma in children and adolescents.

UNLABELLED: The contribution of maximal exercise tests to the evaluation of 180 patients with chest pain associated with exercise (n = 147) or dyspnea on exertion (DOE, n = 33) was examined. The ages ranged from 5 to 22 (mean 13.2) years, and 68 patients were females. All patients had a normal cardiovascular examination, electrocardiogram, chest x-ray, and 2D-echocardiogram. Maximal exercise tests were performed on a treadmill or bicycle ergometer, and flow volume loops were performed before and after exercise (n = 65). Exercise tests did not reveal any cardiovascular abnormalities, but 14 patients with chest pain (9.5%) and seven patients with DOE (21.2%) developed exercise-induced asthma. Postexercise decrease in peak expiratory flow rate was 26.2 +/- 3.7 percent in patients with chest pain and 39.4 +/- 8.9 percent in those with DOE. Only five patients had a personal history and four others had a family history of asthma. Seven patients had a personal or family history of allergies. IMPLICATIONS: exercise-induced asthma should be considered in pediatric patients with symptoms of chest pain or dyspnea on exertion; when exercise tests are performed, flow volume loops should be included before and after exercise; maximal exercise tests are unlikely to unmask any cardiovascular abnormalities in such patients.

Adolescent↗

Age-related responses to stimulation of cardiopulmonary receptors in swine.

Cardiovascular responses to stimulation of cardiopulmonary receptors were evaluated in standard breed developing swine (1-2 days, 1-2 wk, and 2 mo of age) and sexually mature miniswine anesthetized with 0.25-0.50% halothane in O2. Cryptenamine, a mixture of veratrum viride alkaloids (VVA), was administered as right atrial or left ventricular bolus injections in doses of 5-20 micrograms/kg. In developing swine, mean aortic pressure (AoP) decreased after 10-20 micrograms/kg VVA in 1- to 2-wk olds and after 5-20 micrograms/kg VVA in 2-mo olds. Bradycardia was always elicited. Renal (Ren) and femoral (Fem) vasodilation occurred in the 1- to 2-wk-old and 2-mo-old groups after 5-20 micrograms/kg VVA. Mesenteric (Mes) vasodilation was elicited with 10-20 micrograms/kg VVA in the 1- to 2-wk-old group and with 5-20 micrograms/kg VVA in 2-mo olds. In the 1- to 2-day-old group, VVA did not significantly alter Ren, Fem, and Mes vascular resistance. In mature miniswine, 20 micrograms/kg VVA elicited decreases in AoP and heart rate that were similar in magnitude to responses obtained with only 5 micrograms/kg VVA in dogs. Cardiovascular responses to VVA were abolished after bilateral vagotomy but were not altered after denervation of the carotid sinuses. The results indicate postnatal maturation of the Bezold-Jarisch reflex in swine.

Aging↗

Age-dependent cardiovascular effects of verapamil in newborn swine.

Since there are limited studies concerning the hemodynamic effects of verapamil in pediatric patients, cardiovascular effects of clinical doses (100 or 300 micrograms/kg) of verapamil, given as a 2-min intravenous infusion, were examined in sodium pentobarbital anesthetized swine, aged 1 day (n = 15) and 2 wk (n = 18). Aortic and left ventricular pressures, index of left ventricular contractility, heart rate, and phasic superior mesenteric, renal, and femoral arterial flows were recorded; mean aortic pressure and vascular resistances were calculated. Maximum changes in cardiovascular function (mean % delta +/- SEM) occurred at the end of the infusion. Mean aortic pressure and index of left ventricular contractility decreased in all animals; responses were larger in magnitude with the higher dose. By 30 min after infusion of 300 micrograms/kg verapamil had ended, mean aortic pressure in both 1 day and 2 wk olds and index of left ventricular contractility and femoral flow in 1 day olds were still decreased. During infusion of verapamil, heart rate decreased (-11.6 +/- 2.9) to the high dose in 1 day olds but increased (+6.4 +/- 2.7) to 100 and 300 micrograms/kg verapamil in 2 wk olds. After infusion of 300 micrograms/kg verapamil ended, heart rate decreased and reached the nadir (-10.0 +/- 2.9) by 10 min in 2 wk olds. Decreases in renal resistance (-7.6 +/- 1.7) were not dose dependent while superior mesenteric resistance decreased (-12.9 +/- 2.7) only to low dose verapamil in 2 wk olds. In 1 day olds decreases in renal and superior mesenteric resistance were not sustained throughout the infusion.(ABSTRACT TRUNCATED AT 250 WORDS)

Aging↗

Brainstem cells of origin of the cervical vagus and cardiopulmonary nerves in the neonatal pig (Sus scrofa).

The distribution of the cells of origin of the cervical vagus and cardiopulmonary nerves has been studied in neonatal piglets (Sus scrofa) ranging in age from 1 to 60 days. Cardiopulmonary nerves were identified physiologically and anatomically prior to injection of horseradish peroxidase (HRP) into the nerves. Following injection of HRP into the cervical vagus nerve retrogradely labeled neurons were present in the dorsal motor nucleus of the vagus nerve (DMV), the nucleus of the solitary tract, the nucleus ambiguus (NA), ventrolateral to the NA and in an intermediate zone between the DMV and the NA. Two unique clusters of neurons were also retrogradely labeled after injections into the vagus nerve. One group was located lateral to the most caudal levels of the DMV and extended as far caudally as the C1 spinal segment. The second distinctive group was located ventrolateral to the nucleus ambiguus in a cell column identified as the ventrolateral nucleus ambiguus (VLNA). After injections of HRP into cardiopulmonary nerves, the majority of neurons were found in the VLNA and the distinct clusters of neurons in this cell column were particularly heavily labeled. Small numbers of cells were labeled in the DMV and NA and none were labeled in the solitary nucleus after cardiopulmonary nerve injections. There were no apparent age-related differences in the degree or distribution of retrograde labeling. The distribution of neurons in the medulla oblongata projecting into cardiopulmonary nerves in the piglet is similar to that described in other species, i.e., the nucleus ambiguus, particularly its ventrolateral cell column, is the primary site of cardiomotor neurons. In addition, in the piglet there is a morphologically distinct cluster of cells related to the heart, and possibly the lungs, which does not appear to be present in other species.

Animals↗

Altered exercise performance and abnormal sympathetic responses to exercise in patients with anorexia nervosa.

We evaluated the cardiovascular and sympathetic responses to exercise in patients with anorexia nervosa to determine whether their bradycardia results from a high level of physical fitness. Twenty adolescent patients with anorexia nervosa underwent maximal exercise tests, and the results were compared with those in 15 age-matched adolescent girls. In the patients with anorexia, maximal values were heart rate 174 +/- 2.8 bpm, systolic blood pressure 127 +/- 3.4 mm Hg, oxygen consumption 31 +/- 1.1 ml/kg/min, and plasma norepinephrine concentration 1581 +/- 238 pg/ml (n = 16). In the controls, corresponding values were significantly higher (P less than 0.025): heart rate 193 +/- 2.1 bpm, systolic blood pressure 163 +/- 4.4 mm Hg, oxygen consumption 39.3 +/- 1.6 ml/kg/min, and plasma norepinephrine 2695 +/- 413 (n = 10). Anaerobic threshold occurred at the same percent of maximal work in patients and controls. Results of exercise ECGs in all controls were normal, but five patients with anorexia nervosa developed significant ST segment depression. Thus, in patients with anorexia nervosa there is abnormal working capacity and cardiovascular responses to exercise and abnormal sympathetic responses to the stimulus of exercise, and a myocardial abnormality manifested as ST segment depression during exercise in some.

Adolescent↗

Cardiovascular responses to arterial and venous hemorrhage in neonatal swine.

The cardiovascular effects of graded arterial or venous hemorrhage were evaluated in developing swine (less than or equal to 1 day, 2-5 days, 1 wk, and 2 wk of age) anesthetized with halothane in 50% N2O-50% O2. Serial 5-ml/kg aliquots of arterial or venous blood were removed at 3- to 4-min intervals to a cumulative total of 20 ml/kg. Tachycardia occurred in most animals. Decreases in aortic pressure to arterial, but not to venous, hemorrhage were age dependent. Renal, femoral, and carotid arterial flows decreased with hemorrhage in all animals; the decreases in blood flow did not differ among the three circulations and were not age dependent. Increases in femoral resistance were obtained to both arterial and venous hemorrhage only in the 2-wk-old group. As the degree of hemorrhage was increased, aortic pressure, regional blood flow, and femoral resistance (2 wk olds) responses were larger in magnitude. Aortic pressure in piglets 1-5 days of age could not be restored to within 20% of the prehemorrhage level at a smaller bleeding volume with arterial than with venous hemorrhage. Pressor responses to norepinephrine (0.5 micrograms/kg) and to bilateral common carotid occlusion were still present after 20-ml/kg hemorrhage. These responses indicate the presence of a progressive maturation-related compensation to the stress of arterial but not venous hemorrhage.

Animals↗

Cardiac effects of esophageal stimulation: possible relationship between gastroesophageal reflux (GER) and sudden infant death syndrome (SIDS).

Twenty-six artificially ventilated newborn pigs were subjected to simulated gastroesophageal reflux; saline (10 cc) of varying pH was flushed through the esophagus from below. At a given pH threshold, reflex bradycardia, which could be blocked by atropine, was elicited. Transecting of the superior laryngeal nerves, the recurrent laryngeal nerves, and the pharyngeal plexus nerves did not block the reflex bradycardia. However, bypassing the regions superior to the esophagus with a shunt prevented the bradycardia. These results indicate that bradycardia caused by gastroesophageal reflux is independent of changes in ventilation and may be an important cause of sudden infant death.

Animals↗

Maturation-related differences in regional circulatory effects of dopamine infusion in swine.

The cardiovascular effects of dopamine (DPA) infusions were evaluated in developing swine, less than or equal to 1 day, 2 weeks, and 2 months of age, anesthetized with halothane in 50% N2O and O2. DPA was given by intravenous infusion in randomized doses of 2, 5, 10 and 20 micrograms/kg/min for 10 min. Depressor responses and bradycardia were observed during 2 micrograms/kg/min in 2-week-olds and during 2, 5 and 10 micrograms/kg/min in 2-month-olds. During infusion of 20 micrograms/kg/min, DPA pressor responses were observed in animals less than or equal to 2 weeks of age; in addition, tachycardia occurred in 1-day-old swine. Renal resistance decreased during infusion of 2 micrograms/kg/min in all swine. It increased during 10 and 20 micrograms/kg/min in the 1-day and 2-week groups, but not in the 2-month group. Mesenteric resistance decreased during infusion of 2, 5 and 10 micrograms/kg/min in less than or equal to 2-week-olds and at all doses in 2-month-olds. Following combined alpha- and beta-adrenergic receptor blockade, infusion of 20 micrograms/kg/min DPA inhibited renal vasoconstriction in most animals and elicited mesenteric vasodilation in all. The results indicate that dopaminergic responses undergo a postnatal maturation which has a different time course for different regional circulations.

Aging↗

Maturation of central autonomic control of the circulation.

Postnatal maturation of central neural regulation of cardiovascular function is being examined in developing swine. Three major types of investigations have been undertaken: 1) alterations of inputs from visceral and somatic afferents, e.g., baroreceptor manipulation, stimulation of sciatic nerves; 2) stimulation of central vasoactive sites; 3) subjecting the animals to the stresses of hemorrhage, hypoxia, or hypercapnia. Our findings indicate that cardiovascular reflexes mature at different postnatal ages. For example, the J-receptor reflex had almost the adult pattern of response at birth, whereas the Bezold-Jarisch reflex had a markedly delayed postnatal maturation. Recordings of spontaneous discharge in a major efferent sympathetic supply, i.e., the greater splanchnic nerve, have indicated that neural innervation to the adrenal medulla and splanchnic vasculature is present at birth in piglets.

Animals↗

Pulmonary sequestration causing congestive heart failure in infancy: a report of two cases and review of the literature.

Congestive heart failure as a presenting symptom in infants with pulmonary sequestration is rare, and the cases of only 3 such patients have been reported. The clinical features, hemodynamics, and management of two additional patients are described. Both were seen in severe congestive heart failure in the absence of any associated cardiac anomalies. The physical findings, plain roentgenograms, electrocardiograms, and echocardiograms may provide some diagnostic clues, but cardiac catheterization is the essential diagnostic investigation. In 1 patient, pneumonectomy was performed because of extensive changes throughout the affected lung. In the other, ligation of the anomalous systemic artery to the sequestered lobe was the only surgical procedure. Both patients are doing well 15 months and 18 months after operation. Success with the latter surgical approach has not been reported previously.

Bronchopulmonary Sequestration↗

Age-related effects of single injections of dopamine on cardiovascular function in developing swine.

The cardiovascular effects of single intravenous injections of dopamine (DPA; 2, 5, 10 and 25 micrograms/kg) were evaluated in swine, less than or equal to 1 day to 2 months of age, anesthetized with halothane in 50% N2O-O2. Mean aortic pressure increased following all doses of DPA in swine less than or equal to 1 month of age. Renal vasoconstriction was obtained with 5-25 micrograms/kg in the younger animals and with 25 micrograms/kg in the oldest. After 2 micrograms/kg, renal vasodilation occurred in 2-month-old swine. Femoral and carotid vasoconstriction was elicited in day-old swine after 5-25 micrograms/kg DPA, but carotid vasodilation occurred in the oldest swine. Responses to 25 micrograms/kg DPA after combined alpha and beta adrenergic receptor blockade were generally vasodilator. Thus, dopaminergic receptors were unmasked and a postnatal maturation of these receptors was revealed.

Aging↗