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Biomedical subjects

I Heller

Publications and source records attributed to I Heller.

At least 19 recordsLinked to original sources
PubMed1999

CaDet, a computer-based clinical decision support system for early cancer detection.

Cancer risk evaluation and early detection are subject to serious limitations mainly related to human factors and to characteristics of the data involved. To help overcome these problems, a computer-based system was designed to provide the physician with a clearer clinical picture and aid in directing patients to appropriate measures. Clinical and epidemiological data related to early cancer detection and to cancer risk factors was collected from the literature and incorporated in a database, together with heuristic rules for evaluating this data. Individual data obtained from patients through a questionnaire are input into CaDet, a computerized clinical decision support system. A report summarizing patient data and cancer hypotheses, with a scoring system that reflects degrees of alarm, is generated. The CaDet system, as well as some preliminary results of the clinical experience accumulated in its use, are described. These preliminary results suggest that the approach may be useful in improving cancer risk assessment and screening in primary care setups.

Adult↗
PubMed1997

Impact of early exercise radionuclide cineangiography on long-term prognosis after CABG.

BACKGROUND: The immediate benefits of coronary artery bypass grafting might be only transient. This prospective study examined the capability of exercise radionuclide cineangiography done shortly after coronary artery bypass grafting to predict outcome and long-term prognosis. METHODS: Results of exercise radionuclide cineangiography at 5.5 +/- 0.7 months (range, 4 to 8 months) postoperatively were correlated with mortality, major surgical and nonsurgical cardiac events, and cardiac event-free survival in 100 consecutive patients who underwent coronary artery bypass grafting. Stepwise logistic regression analysis was used to evaluate the incremental value of radionuclide cineangiography beyond the commonly used variables. RESULTS: Left ventricular ejection fraction at rest was normal (> or = 0.45) in 72 patients and increased on exercise in 58. The exercise radionuclide variables that correlated with future cardiac events were change and fractional change in heart rate, ST segment changes, anginal pain and congestive heart symptoms during exercise, rest ejection fraction, and change and fractional changes in ejection fraction. Predictors of event-free survival were exercise heart rate, rest ejection fraction, and change and fractional change in ejection fraction during exercise. Logistic regression analysis revealed that change in ejection fraction was an independent predictor of cardiac death and surgical interventions, whereas resting ejection fraction was a predictor of nonsurgical cardiac events. CONCLUSIONS: Postoperative exercise radionuclide cineangiography carried out soon after coronary artery bypass grafting had definite independent prognostic value and should be performed routinely to help decide treatment protocol.

Adult↗
PubMed1995

Bayesian classification of vasculitis: a simulation study.

New classification criteria for vasculitic disorders have recently been proposed by the American College of Rheumatology. These classification criteria have limitations inherent to the method employed in their development. We propose a different approach to the quantitative analysis of the manifestations of vasculitis, which may improve the precision of classification criteria in this domain. Bayesian classifiers were developed for six vasculitides using literature-derived quantitative descriptions of these syndromes. These clinical data were also used in computer programs designed to generate simulations of vasculitis and control cases. The performance of Bayesian classifiers of vasculitis was then compared to that of the American College of Rheumatology criteria, using series of computer-simulated vasculitis cases. Bayesian classifiers identified simulated vasculitis cases with greater accuracy than those of the corresponding American College of Rheumatology 1990 vasculitis criteria in all six diseases studied. As predicted by theoretical considerations, Bayesian classifiers have the potential to identify vasculitis cases more accurately than the proposed American College of Rheumatology 1990 criteria.

Adolescent↗
PubMed1991

Bibliometric study of cardiology in Israel in 1978, 1983 and 1988.

This work presents the results of the first bibliometric study of scientific papers in the field of cardiology in Israel. Using a computer-aided search (Medline), papers published in three selected years (1978, 1983 and 1988) were compared with respect to quantity, type and topic of publication and impact factor. An activity index was designed to measure the relative academic effort devoted to the field of cardiology in Israel. A survey of several cardiological publications worldwide was also carried out. The impact factor and the activity index of Israeli publications markedly increased from 1978 to 1983 but decreased between 1983 and 1988. The ratio of Israeli to world cardiological publications increased from 1978 to 1983, but remained unchanged between 1983 and 1988.

Bibliometrics↗
PubMed1988

Patients with prolonged bleeding time of undefined etiology, and their response to desmopressin.

Between 1981 and 1986, we evaluated 59 patients who presented with isolated prolongation of bleeding time with normal platelet counts, platelet aggregation and coagulation parameters (including von Willebrand's factor), and without evidence of liver or kidney disease, or exposure to anti-platelet agents. These patients, termed as vascular fragility syndrome (VFS), were analyzed to further characterize their bleeding patterns. The pattern of bleeding manifestations was similar to that of patients with platelet dysfunction, such as mucocutaneous bleeding or excessive post-operative bleeding. In 16 patients, desmopressin (1-desamino-8-d-arginine vasopressin, DDAVP) was infused to control active bleeding or as a part of pre-surgical evaluation. Bleeding time improved (pre-DDAVP bleeding time 15.3 +/- 3.4 min, mean +/- S.D.; post-DDAVP bleeding time 10.7 +/- 3.9 min; p less than 0.01) within 30 minutes following the DDAVP infusion with either satisfactory arrest of acute bleeding or good control of subsequent hemostasis with surgery. Side effects with DDAVP were transient and minor, i.e. facial flushing, or conjunctival erythema. These findings indicate that VFS with isolated prolongation of bleeding time is a frequently encountered bleeding disorder and that DDAVP is effective in achieving hemostasis for the management of acute bleeding and may be useful prior to surgical procedures.

Bleeding Time↗
PubMed1987

Segmental air plethysmography in the diagnosis of deep vein thrombosis.

The diagnostic accuracy of segmental air plethysmography using a pulse volume recorder in the detection of deep vein thrombosis (DVT) was assessed. Measurements in 25 limbs with phlebographic proof of DVT and 25 limbs with normal phlebographic examination results were used to develop criteria. With these criteria, a prospective analysis of 50 limbs of patients suspected of having DVT was done. High sensitivity and specificity rates were found for proximal DVT. An accurate plethysmographic diagnosis could not be obtained for nonocclusive DVT or thrombosis confined to calf veins. The accuracy of the segmental air technique was comparable with that of other plethysmographic techniques.

Air↗
PubMed1986

Detection of a tyrosine kinase in human sera and blood cells by pp60src antiserum.

Using sera of Rous sarcoma virus-tumor bearing rabbits (TBR-sera) as a tool to detect pp60src kinase in immunoprecipitates, we report here that about 10% of our TBR-sera revealed tyrosine kinase activity in human serum, plasma and in soluble extracts of human blood cells. The activity found in serum represents 5-12% of the total kinase activity in blood. Most of the enzyme activity was detected in lymphocytes and polymorphonuclear cells rather than in platelets and erythrocytes. We also demonstrate that the tyrosine kinase in serum is inhibited by quercetin, a potent inhibitor of the viral pp60src protein kinase.

Blood Cells↗
PubMed1985

Significant metabolic acidosis induced by acetazolamide. Not a rare complication.

Blood gas and serum electrolyte levels were measured in 27 elderly patients (mean age +/- SD, 63.3 +/- 13.5 years) who were receiving acetazolamide (250 to 1,000 mg/day) for glaucoma. Eleven glaucomatous patients (mean age, 69.1 +/- 7.4 years) who were not receiving acetazolamide served as a control group. In the acetazolamide-treated group, four patients (14.8%) had mild acidosis (7.29 greater than pH less than or equal to 7.31), ten (37%) had moderate acidosis (7.20 greater than pH less than or equal to 7.29), and one patient (3.7%) had severe acidosis (pH, 7.15). None of the patients in the control group had acidosis. It is concluded that moderate metabolic acidosis of potential clinical significance is common among glaucomatous elderly patients who receive acetazolamide. The exact clinical significance of our observations is yet to be determined.

Acetazolamide↗
PubMed1985

High-output cardiac failure as a presenting symptom of plasma cell leukemia.

A patient presented with high-output cardiac failure and was found to have plasma-cell leukemia. No cause for the cardiac failure was found, and there was no response to treatment with diuretics and thiamine. Chemotherapy for the leukemia resulted in resolution of the cardiac failure, suggesting that the latter was caused by the leukemia--a hitherto unreported association.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1978

Assay and properties of IgA protease of Streptococcus sanguis.

An assay procedure for streptococcal IgA protease is described which uses isotopically labelled human serum IgA as substrate. Enzyme activity was monitored by the radioactive counts in the Fab alpha product, which was separated from other components in the digestion mixture by electrophoresis. Cleavage of IgA was linear with respect to time using catalytic amounts of the enzyme. Km was calculated to be 5.5 X 10(-6)M, pH optimum 6.0-7.0 at 37 degrees C, and the enzyme was fully inactivated at low concentrations of the metal chelator ethylenediaminetetraacetic acid.

Edetic Acid↗
PubMed1978

Inclusion body myositis: a distinct variety of idiopathic inflammatory myopathy.

We report six cases of inclusion body myositis (IBM), a distinct but infrequently recognized inflammatory disease of skeletal muscle. Clinically, IBM differs from dermatomyositis and polymyositis. It lacks features of collagen-vascular disease, has a relatively benign and protracted course, frequently involves distal muscles, is found mainly in males, and does not improve with corticosteroid treatment. Electronmicroscopic demonstration of abnormal filaments in muscle cells is necessary for definite diagnosis, but IBM may be suspected by the finding on cryostat sections of numerous hematoxylinophilic granules in "lined" vacuoles in muscle cells. These correspond to whorls of cytomembranes. Although in dermatomyositis the capillary network is partly destroyed, in IBM it is usually augmented. A viral etiology of IBM has been suggested but remains unproven.

Adolescent↗
PubMed1975

Direct evidence for the specific fixation of Cl. botulinum A neurotoxin to brain matter.

Rat brain homogenate and synaptosomes from rat brain bind botulinum toxin. The binding is accompanied by partial inactivation. The binding decreases with increasing ionic strength. A considerable fixation of tetanus toxin can still be demonstrated under conditions which prevent the fixation of botulinum toxin. 2. Only the grey substance, not the white substance from bovine brain is able to bind the toxin. 3. Upon pretreatment with neuraminidase, synaptosomes lose nearly all of their binding capacity. However, neither gangliosides nor ganglioside-cerebroside mixtures nor brain extracts could replace the synaptosomes. Thus botulinum A toxin closely resembles tetanus toxin in its ability to react with (a) neuraminidase-sensitive site(s) of the grey matter of the CNS. It differs from tetanus toxin by its stronger sensitivity against ionic forces and by its failure to react with certain gangliosides.

Animals↗