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Biomedical subjects

A Bass

Publications and source records attributed to A Bass.

At least 73 records · Page 4Linked to original sources
PubMed1989

[Differences in the activity of enzymes associated with energy metabolism in the heart atria and ventricles in children].

Tissue specimens from the right atrium and ventricle of the same heart were obtained during surgery in 45 children operated on account of congenital heart disease (tetralogy of Fallot and ventricular septal defect). Significant differences were found in the enzyme activities between the atrial and ventricular musculature. The activities of enzymes associated with aerobic metabolism (citrate synthase, malate dehydrogenase, with lactate metabolism) lactate dehydrogenase (and the fatty acid oxidation) hydroxyacyl-SoA-dehydrogenase) were significantly higher in the ventricular musculature. Hexokinase, the enzyme responsible for glucose phosphorylation was on the other hand, significantly higher in the atria. From this ensues that the right ventricle can utilize and oxidize to a full extent all main nutrients (fatty acids, glucose and lactate), while the right atrium utilizes above all glucose. These atrio-ventricular differences do not depend on the type of the congenital heart disease and it may be assumed that they exist also in healthy subjects.

Adolescent↗
PubMed1989

[Carotid endarterectomy].

Carotid endarterectomy was performed 77 times in 73 symptomatic patients. In 67 of them there had been 1 or more transient ischemic attacks (TIA), in 4 transient atypical symptoms, and in 2 mild persistent neurological deficits. After operation 1 died of a stroke and 1 had a nonfatal myocardial infarction. In 3.3% of 33 low-risk patients (Sundt's classes 1 and 2) there was mild postoperative neurological deficit. The rate of neurological complications was much higher in 40 high-risk patients (classes 2 and 3), including 5 with postoperative stroke. Followup averaged 21.5 months (longest 54 months), the 5-year survival (by extrapolation from a life table analysis curve) was 87%, and there was only 1 fatal stroke. Those who recovered from operation without complications had an 86% chance of having no further neurological problems.

Carotid Arteries↗
PubMed1989

[Energy-supplying metabolism of the volume overloaded and hypoxia stressed heart in children].

This study summarizes results obtained with regard to atrial and ventricular enzymes of energy supplying metabolism in children with different types of congenital heart disease. In all groups of patients - normoxemic as well as hypoxemic - significant atrio - ventricular differences were observed: the right ventricle is amply equipped for utilization and oxidation of all major nutrients, while the right atrium utilizes glucose predominantly. Myocardial metabolism in children with congenital heart disease was significantly influenced by hypoxemia: the capacity of aerobic enzymes in cyanotic patients was significantly lower, both in atrial and ventricular tissue, whereby the atrial changes were even more striking. No marked differences were found between atrial and ventricular septal defects in normoxemic patients; the only difference was a lower capacity of fatty acid catabolism in children with atrial septal defect.

Adolescent↗
PubMed1989

Effect of hypoxaemia on enzymes supplying myocardial energy in children with congenital heart disease.

The differences in energy metabolism of the myocardium in children with congenital cardiac malformations producing hypoxaemia (arterial oxygen saturation 77 +/- 2%) or normoxaemia (arterial oxygen saturation 94 +/- 2%) were analysed by measuring the activity of the representative energy-supplying enzymes. Right atrial and ventricular tissue samples were obtained during surgical interventions. We demonstrated that myocardial metabolism was significantly influenced by hypoxaemia: the aerobic capacity of the energetic metabolism was reduced both in the atriums and ventricles. Atrial myocardium was more affected: in addition to citrate synthase, the activity of enzymes connected with lactate uptake and carbohydrate catabolism was also significantly decreased. These results demonstrate that the human heart is able to adapt to hypoxaemia by changing its energetic metabolism.

Adolescent↗
PubMed1989

The elusive isolated hypogastric artery aneurysm: novel presentations.

Isolated aneurysms of the internal iliac artery are rare. Their anatomic location makes them true pelvic aneurysms and they may grow to a large size undetected. Their late recognition may be prompted by rupture or symptoms related to compression of neurologic, gastrointestinal, genitourinary, or venous structures. We have encountered three isolated hypogastric artery aneurysms with unique presentations. In one patient with bilateral isolated hypogastric artery aneurysms, one ruptured into the bladder, and at a later time the other caused ureteral obstruction. Another patient had obturator neuropathy as a result of his aneurysm. In the patient with large bilateral aneurysms, one was detected by rectal examination, and the other was found by palpation of the abdomen. The second patient with a smaller aneurysm required examination of the pelvis by CT scanning to establish the diagnosis. Awareness of the existence of these lesions is required to identify such patients who describe symptoms uncommonly associated with abdominal aneurysms. Operative management consisted of exclusion of the aneurysm and partial or complete aneurysmorrhaphy with preservation of iliac arterial flow to maintain extremity perfusion. Recovery was complete in each instance. A review of published cases is presented.

Abdomen↗
PubMed1989

Intraoperative transcranial Doppler: limitations of the method.

To test the hypothesis that the transcranial Doppler is a useful technique for intraoperative neuromonitoring, we prospectively used it to study 83 patients undergoing carotid end-arterectomy. A 2 MHz pulsed-wave, range-gated transcranial Doppler was positioned at the transtemporal window after induction of general anesthesia. Mean middle cerebral artery velocity, intraarterial blood pressure, end-tidal PCO2, heart rate, and a spectral array of electroencephalographic activity were recorded continuously throughout the operation. Internal carotid artery back pressure was measured routinely. On completion of the endarterectomy, duplex ultrasound examinations and arteriograms were uniformly obtained to assess technical adequacy. Forty-nine of the 83 patients (60%) had complete preoperative and intraoperative transcranial Doppler examinations. Eleven (13%) had incomplete assessments because of small or absent transtemporal windows. Twenty-three (27%) had unsuccessful monitoring because of technical difficulties, primarily because of inability to maintain probe position--with loss of mean middle cerebral artery velocity recording. In the patients with complete studies, transcranial Doppler failed to provide information that altered surgical therapy. All monitoring modalities were normal in the one patient (1.2%) who sustained an operative stroke. We conclude that at this time, transcranial Doppler has not been useful to routinely monitor the intraoperative events during carotid endarterectomy.

Aged↗
PubMed1989

The effect of chronic hypoxia on the developing cardiopulmonary system.

The effect of chronic hypoxia (barochamber, 8 h per day, 5 days a week, stepwise up to 7000 m) on some cardiac functional and metabolic parameters was compared in rats acclimatized either from the 4th day or the 12th week of postnatal life. Pulmonary hypertension and right ventricular enlargement were found in both age group. Whereas in young hypoxic animals the weight of the right ventricle increased linearly with the right ventricular pressure, in adult high altitude exposed rats this relation could not be proved. High altitude induced significant increase of concentration of collagenous proteins: in adult animals increased collagen III only, in young also collagen I. The changes of the energy metabolism were similar in both age groups: activity of enzymes of the lactate metabolism and glucose phosphorylation increased; on the other hand, catabolism of fatty acids decreased. Chronic hypoxemia significantly influenced also the myocardial metabolism in children with congenital heart disease; the aerobic capacity was decreased both in the atrial and ventricular tissue; atrial changes were even more pronounced. The type of changes was, however, different from the rat heart.

Acclimatization↗
PubMed1989

Intermittent high altitude--induced changes in energy metabolism in the rat myocardium and their reversibility.

Selected enzyme activities of energy metabolism were studied in the myocardium of laboratory rats exposed to intermittent altitude hypoxia (IAH, 4-8 h daily, 5 days a week, in a hypobaric chamber, stepwise up to 7,000 m). No significant differences were found between the right and the left ventricle in the control animals. Glucose-utilizing capacity (HK) and capacity for the synthesis and degradation of lactate (LDH) increased significantly in both ventricles during acclimatization. The other enzyme activities associated with anaerobic glycolysis (TPDH, GPDH) and those linked up in aerobic metabolism (MDH, CS) did not change significantly. On the other hand, the ability to break down fatty acids (HOADH) decreased significantly. All the above changes in the enzyme profile were found after only 24 4-h exposures, in both the hypertrophic right ventricle and the unenlarged left ventricle. When the length of daily exposure was raised from 4 to 8 h, the above changes were not intensified and 45 days after the last exposure to IAH, none of the given activity values differed from those estimated in the corresponding control animals.

3-Hydroxyacyl CoA Dehydrogenases↗
PubMed1987

Jejunogastric intussusception. A new diagnostic test.

Jejunogastric intussusception is a rare complication of gastrojejunal reconstruction of unknown cause. There are two types of jejunogastric intussusception: the acute type, presenting as a surgical emergency, and the chronic intermittent type, which is difficult to diagnose and is usually of mild symptomatology but which may progress to the acute type with the incarceration of the intussusceptum. With two case reports and a literature review, an endoscopic diagnostic maneuver is proposed, hinting at disordered motility with reversed peristalsis as a possible causative factor. Corrective surgical treatment to prevent recurrence and incarceration in chronic cases is advocated. Treatment should include dismantling of the efferent loop, which is the most frequent intussusceptum.

Aged↗
PubMed1987

Percutaneous transluminal angioplasty of the distal abdominal aorta and its bifurcation.

Percutaneous transluminal angioplasty (PTA) of stenotic lesions in the distal abdominal aorta and its bifurcation was performed in 14 patients, 6 of whom were women. The stenotic segment in the aorta or aortic bifurcation was usually the only significant lesion. The double-balloon technique was used in 12 patients via bilateral femoral artery catheterizations. In 2 other patients with aortic lesions, a single large balloon sufficed. Good results were achieved in all but 1 patient, with minor complications occurring in 3 instances. The follow-up period varied from 6 months to 5 years. We believe that PTA is the procedure of choice in treating localized lesions of the distal abdominal aorta and its bifurcation, especially when distal vessels are relatively uninvolved.

Adult↗
PubMed1987

Percutaneous transluminal recanalization of common iliac artery occlusions.

Percutaneous transluminal recanalization of occluded iliac arteries was attempted in 25 patients (26 limbs). In 22, successful recanalization was achieved, although 4 patients required additional surgical thrombectomy. The remaining 4 patients had surgical bypass procedures. The early and late results of percutaneous recanalization are presented as well as the technique used. We conclude that percutaneous recanalization of iliac occlusion is an effective procedure in the majority of cases. The option of surgical treatment remains viable when the percutaneous approach is unsuccessful.

Adult↗
PubMed1987

Simplified assessment of arterial graft patency using indium-labelled-platelet scintigraphy.

Arterial grafts were studied with indium-III-labelled platelets in 13 patients (18 graft limbs) in the early post-implication period. Platelet thrombogenic activity was graded into four grades by visual inspection of the images, and scintigraphic criteria of impending graft occlusion were defined. Dacron and polytetrafluoroethylene grafts had similar high thrombogenic activity in comparison with autologous veins. Nine graft studies showed patterns of radioactivity concentration that suggested threatening thrombosis and eight of these eventually occluded. In nine other studies absent to moderate radiolabelled platelet activity was observed and none occluded within a mean follow-up period of 24 months. Prediction of graft occlusion of scintigraphic evaluation using the present simple non-invasive technique is valuable since corrective measures may be instituted earlier and with greater success in the post-operative follow-up period.

Aged↗
PubMed1987

Clinical presentation of suspected carotid artery disease. Screening of candidates for arteriography with the assistance of the vascular laboratory.

The evaluation of suspected carotid artery disease was reviewed in a consecutive series of 292 patients referred by attending physicians in a university hospital. Twenty-three percent of the patients presented with classical transient ischemic attacks, and all those suitable for eventual surgery were recommended for arteriography. In 75% of the patients the presenting symptoms were nonlateralizing or equivocal. In this group the results of noninvasive vascular tests were decisive as to the recommendation for arteriography, which was positive in 79% of those performed. Among 100 surveyed patients who did not undergo arteriography, cerebrovascular accidents occurred in 3 patients: carotid disease was detected in 2 of them, in whom arteriography had been postponed for clinical reasons, while in the third a subsequent arteriography demonstrated no carotid lesion. Expert clinical assessment assisted by vascular studies prevented unnecessary arteriography in 62% and detected carotid pathology with atypical presentation in 13% of the patients.

Adolescent↗
PubMed1987

Renovascular hypertension in spontaneous hypertensive rats: an experimental model of renal artery stenosis superimposed on essential hypertension.

Renovascular hypertension superimposed on essential hypertension, a condition encountered in the elderly, was studied. An experimental animal model consisting of a two-kidney one-clip Goldblatt preparation in the spontaneous hypertensive (SHR) rat, that would simulate this condition, was designed. A 0.25 mm silver clip was placed on the left renal artery of SHR male rats. The same procedure performed on WKY rats served as control. All experiments were performed on low, normal, and rich sodium diet. Systolic blood pressure (BP) was measured by tail-cuff method. Plasma renin concentration (PRC) was determined before and after clipping of the renal artery. Results were as follows: Mean systolic BP increased significantly in clipped rats fed with normal and rich sodium diets. SHR showed an increase from 144 +/- 3 (mean + s.e.m.) to 168 +/- 3 mmHg, and WKY rats showed an increase from 120 +/- 2 to 139 +/- 5 mmHg. There was a two- to threefold rise in PRC. A low-salt diet given prior to clipping prevented the appearance of renovascular hypertension despite a significant rise in PRC. We concluded that renal artery narrowing plays a significant role in the rise of BP in the basically essential type of hypertension.

Animals↗