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Biomedical subjects

A Tenenbaum

Publications and source records attributed to A Tenenbaum.

At least 55 records · Page 3Linked to original sources
PubMed1998

Comparison of coronary calcium in stable angina pectoris and in first acute myocardial infarction utilizing double helical computerized tomography.

Although coronary calcium is invariably associated with atherosclerosis, its role in the pathogenesis of acute and chronic coronary syndromes remains unclear. Utilizing double helical computerized tomography we evaluated the coronary calcium patterns in 149 patients: 47 with chronic stable angina (SAP) compared with 102 patients surviving a first acute myocardial infarction (AMI). Prevalence of coronary calcium was 81% among the AMI patients and 100% in the stable angina patients. The 547 calcific lesions identified in the AMI patients and the 1,242 lesions in the stable angina patients were categorized into 3 groups according to their extent: mild, intermediate, and extensive. The age-adjusted percentages of the highest level of calcification among AMI versus stable angina patients were: mild 18% vs 3%, intermediate 49% vs 18%, and extensive lesions 33% vs 79%, respectively (p < 0.01). In the AMI group, 73 culprit arteries were identified: 16 (22%) had no calcium detected, whereas 30 (41%) had mild lesions, 20 (27%) had intermediate forms, and only 7 (10%) had extensive lesions. The age-adjusted mean of the natural logarithm transformation of total calcium scores +1 was significantly lower in patients with AMI than in those with SAP (4.1 [95% confidence interval 3.7 to 4.4) vs 5.3 [95% confidence interval 4.8 to 5.8]). Thus, double helical computerized tomography demonstrates that extensive calcium characterizes the coronary arteries of patients with chronic stable angina, whereas a first AMI most often occurs in mildly calcified or noncalcified culprit arteries.

Aged↗
PubMed1998

Clinical characteristics of ruptured chordae tendineae in hospitalized patients: primary tear versus infective endocarditis.

BACKGROUND: Several etiologies have been associated with the rupture of chordae tendineae. The leading causes are infective endocarditis, primary rupture, and the association with various connective tissue disorders. HYPOTHESIS: In order to define the attributes of these patients, a retrospective study was conducted that investigated the medical files of hospitalized patients in the Sheba Medical Center, Tel-Hashomer, Israel. METHODS: Twenty patients (17 men, 3 women) with ruptured chordae were detected. Primary rupture of the chordae tendineae had been diagnosed in 11 patients, while infectious endocarditis was the cause for the tear of the chordae tendineae in 9 patients. The patients who had primary rupture of the chordae were older than the patients with endocarditis (67.4 +/- 11.3 vs. 57 +/- 9.3 years, respectively, p < 0.05). RESULTS: The posterior mitral valve cusp was more commonly involved (15 patients). Six of the patients with posterior mitral valve cusp involvement manifested atrial fibrillation. Mitral valve prolapse (MVP) was detected among seven patients, six of whom belonged to the group with infective endocarditis. CONCLUSION: Primary tear and infective endocarditis are leading etiologies of ruptured chordae tendineae in hospitalized patients. Particularly among the patients with infective endocarditis, concomitant MVP was frequently detected. It is the authors' opinion that this coexistence implies that MVP may predispose to the rupture of chordae tendineae.

Aged↗
PubMed1998

Role of arachidonic acid metabolites in the action of a beta adrenergic agonist on human monocyte phagocytosis.

The mechanisms by which beta adrenergic stimulation regulates phagocytosis of Candida albicans by human peripheral monocytes (HPM) are characterized. Isoproterenol (ISO) inhibits phagocytosis in a concentration-dependent manner. This effect was blunted by propranolol, inhibitors of phospholipase A2 (PLA2), cyclooxygenase and verapamil, pointing to a participation of arachidonic acid (AA) metabolites and calcium in the phenomenon. Prostaglandin E2 (PGE2) and dibutyryl cyclic AMP (db-cAMP) also exerted the same inhibitory effect on phagocytosis. ISO interacts with beta adrenergic receptors of HPM increasing PGE2 and cAMP. We conclude that the mechanisms by which beta adrenergic stimulation regulates phagocytosis of Candida albicans by HPM appear to be secondary to beta adrenoceptor-mediated hydrolysis of AA accompanied by an increase in PGE2 generation and cAMP production. Both PGE2 and cAMP could act as mediators of the inhibitory action of beta agonists on the HPM-phagocytosis process.

Acetophenones↗
PubMed1998

Exercise-induced aortic flow parameters in early postmenopausal women and middle-aged men.

OBJECTIVE: Exercise Doppler echocardiography has been recognised as an accurate method for the assessment of left ventricular function in patients with coronary artery disease. Gender differences in aortic flow parameters during exercise have not been well established. The aims of this study were to compare basal ejection Doppler indexes in healthy early postmenopausal women with those of men, and to assess the effects of both isometric and dynamic exercises on these parameters. DESIGN: Intergroup comparison between early postmenopausal women and middle-aged men. SUBJECTS: Fifteen healthy women with a mean age of 55 (SD 5) years and 15 healthy men aged 52 (SD 4) were evaluated. SETTING: Women were recruited from a menopause clinic and men from a primary cardiovascular prevention program at a cardiac rehabilitation institute. INTERVENTIONS: Isometric exercise was performed with a 2-hand bar dynamometer, and dynamic exercise with a supine ergometer. Echo Doppler examination was performed at rest and at peak isometric and dynamic exercise with a pulsed Doppler transducer. RESULTS: Both types of exercise resulted in higher values of hemodynamic parameters in the women, with most figures reaching statistical significance. Most aortic flow parameters during rest and exercise were also significantly higher in the women. CONCLUSIONS: The unexpected higher values in hemodynamic and aortic flow parameters in early postmenopausal women as compared with middle aged men may shed light on a peculiar aspect of gender differences in cardiovascular function, perhaps specific to this age group and related to menopausal transition.

Aorta↗
PubMed1998

Developmental correlates of school-age children with a history of benign congenital hypotonia.

In order to clarify the prognosis of benign congenital hypotonia (BCH), 25 children aged 6 to 8 years who had been diagnosed with BCH as infants were examined on a variety of sensory, perceptual-motor, and behavioural measures and compared with 26 control children. There were no significant differences between the two groups on any of the medical or neurological measures of the Touwen Neurological Examination (Touwen 1979), nor were there significant overall differences on any of the sensory or behavioural measures. However, the BCH group showed inferior gross motor performance on the Bruininks-Oseretsky Test of Motor Proficiency (Bruininks 1978). They scored significantly lower on the Gross Motor Composite, and performed worse on each of the four Gross Motor Subtests, reaching significance on two: Bilateral Coordination and Strength. The follow-up of children with BCH should continue even after the apparent resolution of the hypotonia, with particular attention to the gross motor aspects of performance.

Child↗
PubMed1998

Dual-helical CT for detecting aortic atheromas as a source of stroke: comparison with transesophageal echocardiography.

PURPOSE: To investigate whether unenhanced dual-helical computed tomography (CT) is useful in the rapid, noninvasive detection of protruding aortic atheromas. MATERIALS AND METHODS: Thirty-two consecutive patients at least 50 years of age who had recent ischemic stroke, systemic emboli, or both, underwent transesophageal echocardiography (TEE) and unenhanced dual-helical CT with thin sections (section thickness, 3.2 mm; reconstruction increment, 1.5 mm). RESULTS: TEE demonstrated protruding aortic atheromas 15 patients (47%); dual-helical CT depicted protruding aortic atheromas in 13 of those 15 patients (87%). Of the 17 patients without a protruding aortic atheroma at TEE, dual-helical CT helped confirm the absence in 14 (82%). Dual-helical CT yielded a sensitivity of 87%, a specificity of 82%, and an overall accuracy of 84%. Thirty-six protruding plaques were detected with TEE, of which 34 (94%) were correctly identified with dual-helical CT. Of those 34 plaques, 27 (79%) contained variable amounts of calcium and seven (21%) showed hypoattenuation suggestive of soft plaques and thrombi. In six patients, dual-helical CT depicted a protruding aortic atheroma between the distal ascending aorta and the proximal arch; these plaques were not included in the comparative statistics and were analyzed separately. CONCLUSION: Unenhanced dual-helical CT with thin sections appears to be useful for the rapid, noninvasive detection of a protruding aortic atheroma, especially in areas not clearly visualized with TEE.

Aorta↗
PubMed1998

Disrupted mobile aortic plaques are a major risk factor for systemic embolism in the elderly.

Protruding aortic plaques--especially those with mobile properties--on transesophageal echocardiography (TEE) are a potential source of stroke and systemic embolism in the elderly. Whether the various morphologies of atheromas with mobile components represent potential differences in the risk for embolic events has not been thoroughly elucidated. The goal of the present study was to determine the association between embolic events and the various types of mobile lesions in the thoracic aorta. Our population consisted of 569 consecutive patients (age 18-83 years) referred for TEE over 27 months; 108 (19%) of them were referred to evaluate recent embolism (cerebral in 97 and peripheral or both in 11; group I) and the remaining 461 were admitted for reasons unrelated to embolism (group II). In group I, 35 patients (32%) exhibited protruding plaques; those were fixed in 10 (9%) and with a mobile component in 25 (23%). In group II, plaques were found in only 13 patients (3%); fixed in 9 (2%) and mobile in 4 (1 %). Twenty-four patients with mobile lesions in group I were > 50 years old, and 21 of them (88%) were > 60 years old. While the presence of fixed plaques was associated with a moderate increase in the risk for systemic embolism (adjusted odds ratio 4.1; 95% confidence interval 1.3-56.4), mobile lesions were linked to a striking augmentation of this risk (odds ratio 30.1; 95% confidence interval 7.8-132.6). The majority of mobile lesions (76%) in group I represented disrupted atheromas with characteristic ulcerations or echolucency within the plaque suggestive of intraatheroma hemorrhage, whereas these TEE features were not observed in 89% of the mobile lesions in group II (p = 0.0003). We conclude that among the various types of mobile aortic lesions, the disrupted protruding plaques are a major risk factor for stroke and embolic events in the elderly.

Adolescent↗
PubMed1998

L-Arginine: rediscovery in progress.

Since the recognition that L-arginine (LA) is the natural metabolic donor of nitric oxide, this amino acid has reached the medical spotlight. LA exerts favorable effects in the prevention and treatment of endothelial damage and the restoration of endothelial function in patients with cardiovascular risk factors (hypercholesterolemia, smoking, hypertension, diabetes and advanced age) or with several chronic cardiovascular disorders (coronary, peripheral and cerebral vascular disease, and mild-to-moderate heart failure). LA administration is likely to represent a potentially novel therapeutic strategy during angioplasty, coronary bypass grafting and cardiac transplantation. More conclusive research findings for the rediscovered role of this well-known substance merit close attention.

Animals↗
PubMed1998

Is early intervention effective in preventing ADHD?

The purpose of this study was to examine whether early intervention by non-pharmacologic means (occupational therapy and speech therapy) can decrease the incidence of ADHD in a group of preschool children at high risk for developing this syndrome. Fifty-one children who suffered at the age of 2-4.5 years from inattention, speech delay and/or motor delay with or without hyperactivity were reexamined at the age of 8-10 years (average 8.9 +/- 1.0 years) by a developmental pediatrician and a developmental psychologist, using the following tests and questionnaires: WISC-R IQ test, Touwen and Prechtl neurological examination for soft neurological signs and the DSM-III-R questionnaire for parents and teachers for the assessment of inattention and hyperactivity. A detailed medical questionnaire was also completed. Of 51 children, 20 (39%) had ADHD. Of these 20 children, 8 had a history of ADHD in other siblings. We found that in children with a family history of this syndrome early intervention reduced the incidence of ADHD at school age although the small numbers limit conclusions and need further replication.

Analysis of Variance↗
PubMed1997

Comparison of left ventricular function using isometric exercise Doppler echocardiography in competitive runners and weightlifters versus sedentary individuals.

It is unclear whether cardiovascular responses to heavy isometric exercise are changed by intensive training. We evaluated the effects of this type of exercise on left ventricular (LV) function in athletes engaged in static and dynamic sport, compared with sedentary persons, and looked for peculiarities in static athletes' responses that might reflect adaptive mechanisms to their specific activity. The study population comprised 45 men (age 24 +/- 5 years): 29 dynamic and 16 static athletes (runners and weightlifters, respectively). The control group consisted of 20 age and gender-matched healthy sedentary persons. All performed 50% of maximal voluntary contraction on a whole-body isometric exercise device for 2 minutes. Echocardiographic calculations were determined at rest and exercise. Upon exercise, stroke volume, cardiac output, end-diastolic volume, and ejection fraction increased significantly in athletes, while end-systolic volume and systemic vascular resistance decreased. In sedentary persons, stroke volume and resistance remained unchanged, cardiac output and LV volumes increased, and ejection fraction decreased from 67 +/- 5% to 60 +/- 5% (p <0.01 compared with rest; p <0.0001 compared with athletes). Whereas peak flow velocity decreased from 103 +/- 10 to 81 +/- 6 cm/s in sedentary persons, it increased from 112 +/- 9 to 126 +/- 8 cm/s in the static group and from 120 +/-3 to 126 +/- 9 cm/s in the dynamic athletes (p <0.0001 compared with the sedentary group). Mean acceleration decreased in the sedentary group, remained unchanged among the dynamic athletes, and increased among the static athletes. We conclude that cardiovascular responses to heavy isometric exercise are modified by intensive training. Athletes, taken as a group, react differently and adapt better than sedentary individuals. Moreover, among them, those involved in static sport show an improved cardiovascular adaptation to this type of exercise.

Adult↗
PubMed1997

Effect of peritoneal fluid from patients with mild and severe endometriosis on endometrial stromal cell proliferation.

The aim of this study was to evaluate and compare the mitogenic effect of peritoneal fluid (PF) from women with mild and severe endometriosis on the endometrial stromal cell proliferation. Increasing concentrations of PF from women with and without mild or severe endometriosis were added to primary endometrial stromal cell cultures and 3H-thymidine incorporation was used to assess DNA synthesis in these cultures. PF from women with mild endometriosis induced a statistically significant dose-dependent increase in stromal cell thymidine uptake ranged from 5.8 to 14.5 fold, whereas PF from women with severe endometriosis produced an average 51% inhibition of stromal cell proliferation of compared with cells exposed to non-endometriosis PF or exposed to nutrient medium supplemented with 2.5% calf serum alone. PF samples from patients with stage I endometriosis induced a statistically dose-dependent increase in stromal cell proliferation, whereas PF from patients with stage IV endometriosis caused a significant inhibition.

Ascitic Fluid↗
PubMed1997

Coronary calcium measurements by double helical computed tomography. Using the average instead of peak density algorithm improves reproducibility.

RATIONALE AND OBJECTIVES: Coronary calcium (CC) measured by fast computed tomography (CT) was proposed recently as a noninvasive method of monitoring the coronary atherosclerotic process. Assessment of the reproducibility of CC measurements (mainly interstudy variability) is essential for consistent interpretation of serial studies. METHODS: The authors scanned 74 patients (50 men and 24 women) twice on the same day to determine the interstudy variability of a new scoring algorithm, using the average instead of conventional peak CT density values. RESULTS: Nineteen patients had no calcium on either scan. In the remaining 55 patients, interstudy variability was decreased by 31% using the average algorithm (32%-23%; P < 0.001). CONCLUSIONS: Using the average instead of conventional peak density score provides better reproducible measurements of calcium by double helical CT.

Adult↗
PubMed1997

Coronary artery calcification in women with syndrome X: usefulness of double-helical CT for detection.

PURPOSE: To determine the usefulness of double-helical computed tomography (CT) for detection of diseased coronary arteries in women with anginal pain, positive exercise stress test results, and angiographically normal coronary arteries (syndrome X). MATERIALS AND METHODS: Double-helical CT of the coronary arteries was performed in 81 consecutive women who were referred for coronary angiography for evaluation of chest pain. Patients were classified into three groups according to stress test and angiographic results: normal (normal exercise test results and angiographically normal coronary arteries), syndrome X (abnormal exercise test results and angiographically normal coronary arteries), and coronary artery disease (at least one diseased vessel seen at angiography). RESULTS: The prevalence of coronary calcification in the syndrome X group was 63% (10 of 16 patients) compared with 96% (45 of 47 patients) in the coronary artery disease group (P = .002) and 22% (four of 18 patients) in the normal group (P = .02). The lowest total coronary calcification score and logarithmic transformed data were found in the normal group (2.9 +/- 0.7), statistically significantly higher values were found in the syndrome X group (4.3 +/- 1.5), and the highest values were found in the coronary artery disease group (5.1 +/- 2.0; for trend, P = .03). CONCLUSION: Double-helical CT may be useful in detection of atherosclerosis in women with syndrome X who demonstrate normal coronary arteries at angiography.

Calcinosis↗
PubMed1996

Murine peritoneal macrophages in syngeneic and allogeneic pregnancies.

We have previously observed that some functional characteristics of peritoneal macrophages (MOp) are altered during syngeneic murine pregnancy. To determine if these alterations are related to the immunological stimulation that the embryo produces on the mother, we evaluated MOp activity in allogeneic pregnancy. We also compared expression of the la antigen, ability to phagocyte and reduce nitro blue tetrazolium (NBT) and to produce interleukin-1 (IL-1) in allogeneic and syngeneic pregnancies. We observed that at Day 7 of pregnancy the increment in MOpIa(+) percentages was more evident in allogeneic (P < 0.05) than syngeneic pregnancies, and that these values remained high during the second week of gestation. We also observed a significant decrease in the macrophages that reduced NAT during the first week both in allogeneic and syngeneic pregnancies. Yet, in the former, the percentages of MOpNBT(+) were still low in the last week of pregnancy (P < 0.05). No differences were found in IL-1 production or in estradiol and progesterone levels between the 2 types of pregnancies. Thus, it is possible to postulate that during the first week of pregnancy the strong antigenic challenge that the embryo represents may activate MOp and that this activation could be augmented when major antigenic differences between mother and embryo are present.

Journal Article↗
PubMed1996

Shortened Doppler-derived mitral A wave deceleration time: an important predictor of elevated left ventricular filling pressure.

OBJECTIVES: The aim of this study was to investigate whether a new variable of mitral inflow, A wave deceleration time, identifies patients with elevated left ventricular filling pressures. BACKGROUND: In patients with an elevated left ventricular end-diastolic pressure, the increase in left ventricular pressure after atrial contraction rapidly exceeds left atrial pressure, resulting in abrupt cessation of the A wave. Therefore, we postulated that a shortening of A wave deceleration time might be a marker for elevated end-diastolic pressure. METHODS: Adequate pulsed Doppler mitral inflow velocities could be recorded in 40 of 44 consecutive patients undergoing cardiac catheterization with capillary wedge pressure in 20 patients, and within 1 h after left ventricular end-diastolic pressure recording in 20. Fifteen healthy volunteers were also studied. RESULTS: Left ventricular end-diastolic pressure was 8 to 35 mm Hg, and mean pulmonary wedge pressure was 6 to 37 mm Hg. Close correlations were found between A wave deceleration time and mean pulmonary wedge pressure (r = -0.87) and left ventricular end-diastolic pressure (r = -0.74). There were modest correlations between both pressures and peak E/A, E wave deceleration time and A wave duration, respectively; r = 0.59, -0.30 and -0.58 for capillary wedge and r = 0.25, -0.38 and -0.49 for end-diastolic pressures. A wave deceleration time </= 60 ms predicted left ventricular end-diastolic and mean pulmonary wedge pressures > 18 mm Hg, respectively, with a sensitivity of 67% and 89% and specificity of 100% for both. CONCLUSIONS: A shortened Doppler mitral inflow A wave deceleration time is a useful index of elevated left ventricular filling pressure.

Adolescent↗