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Biomedical subjects

D Weiss

Publications and source records attributed to D Weiss.

At least 37 records · Page 2Linked to original sources
PubMed1988

R wave amplitude changes during stress testing in ischemic patients with normal epicardial coronary arteries.

R wave amplitude changes during stress testing were validated in 12 ischemic patients with normal coronary angiograms. The data were compared with findings obtained from 10 patients with clinical and angiographic evidence of coronary arterial disease and 10 normal controls. An abnormal R wave amplitude response occurred in 83.3% of the group with normal coronary angiography, in 80% of the group of patients with clinical and angiographic evidence of coronary arterial disease, and in only 10% of the control group. The similarity of R wave amplitude changes in the first two group suggests that these changes are related to ischemia. If so, then R wave amplitude response to exercise could be of value in the electrocardiographic diagnosis of ischemia in patients with angiographically normal coronary arteries.

Adult↗
PubMed1987

A single bone marrow-derived stromal cell type supports the in vitro growth of early lymphoid and myeloid cells.

A clonal cell line (ALC) derived from murine bone marrow stroma is capable of supporting the continuous, in vitro growth of early lymphoid and myeloid cell populations. The growth-promoting effects of ALC are in part mediated through M-CSF and a pre-B cell growth factor, both of which accumulate in ALC-culture supernatant. To analyze the lymphoid growth factor produced by ALC cells, we derived a pre-B cell indicator line that is dependent on ALC-growth-conditioned medium. Using a combination of biological and biochemical analyses, we have established that the pre-B cell growth factor produced by ALC cells is distinct from IL-1, IL-2, IL-3, and IL-4 (BSF-1), suggesting that the early stages of B-cell development are regulated by a unique stroma-derived growth factor.

Animals↗
PubMed1987

The current evaluation of nonpalpable breast lesions.

To understand the suspected low yield of malignant neoplasms from biopsies guided by needle localization, we reviewed 122 biopsies performed from January 1985 to November 1986 at University Hospital and Arkansas Baptist Medical Center, Little Rock. The positive biopsy rates were 3.5% and 10.6%, respectively. After review of these cases, the following guidelines for biopsy were developed: (1) Do not perform a biopsy on a low-density mass less than 1 cm in diameter. (2) Do not perform a biopsy for asymmetric density or questionable mass. (3) Do not perform a biopsy for secondary signs of malignancy such as skin thickening or asymmetric vasculature. (4) Biopsy is indicated for clustered calcifications, a dominant mass greater than 1 cm in diameter, stellate lesions, or interval change from a previous mammogram. These changes resulted in a positive biopsy rate of 15% for the period from November 1986 through April 1987.

Biopsy, Needle↗
PubMed1987

Torsade de pointes complicating atrioventricular block: report of two cases.

One patient with complete atrioventricular heart block and another with high-degree atrioventricular block, complicated by "torsade de pointes" are presented. Both patients were symptomatic. One had a syncopal episode and the other presented with signs and symptoms of congestive heart failure. The electrocardiographic phenomena of torsade de pointes was repeatedly recorded. No other known predisposing factors for torsade de pointes were identified. The use of right ventricular endocardial pacing suppressed the paroxysms in both patients.

Aged↗
PubMed1987

The value of electrocardiography in patients with right ventricular endocardial pacemakers in the diagnosis of left ventricular hypertrophy: a correlative study of pace electrocardiography and left ventricular mass derived from M-mode echocardiography.

This study evaluated 51 patients with permanent apical right ventricular endocardial pacemakers. The assessment of the diagnostic value of pace electrocardiograms for the determination of left ventricular hypertrophy revealed specificity of 94% and sensitivity of 66%, applying a new parameter: RL1 + SV3 greater than or equal to 30 mm. The application of this criterion in the interpretation of pace electrocardiograms correlated well with values for the left ventricular mass derived from M-mode echocardiograms (r = 0.644, P less than 0.0001).

Aged↗
PubMed1987

Transient complete atrioventricular dissociation and asystole following junctional premature beats in a patient with acute myocardial infarction.

A 58-year-old patient is presented with recurrent episodes of complete atrioventricular dissociation and asystole which followed junctional premature beats during the acute phase of myocardial infarction. This uncommon electrocardiographic phenomenon occurred when junctional premature beats interfered with the conduction in a previously compromised atrioventricular node, leading to the above-mentioned electrocardiographic phenomenon.

Arrhythmias, Cardiac↗
PubMed1987

Atrioventricular block complicating dissecting aneurysm of the aorta.

A 67-year-old patient who presented with acute dissecting aneurysm of the aorta was complicated by progressive transient atrioventricular heart block. Post-mortem examination findings confirmed the diagnosis of dissection of the ascending aorta and revealed an interatrial haemorrhage in the area of the septal atrioventricular junction.

Aged↗
PubMed1987

Pacemaker Twiddler's syndrome.

The pacemaker Twiddler's syndrome was recognized in a patient who presented with dizziness due to failure of his recently implanted endomyocardial permanent pacemaker system. Electrocardiographic, X-ray and intraoperative findings are presented.

Aged↗
PubMed1986

Ciprofloxacin: a comparative evaluation of its bactericidal activity in human serum against four enterobacterial species.

Serum bactericidal titres following a 200 mg i.v. dose of ciprofloxacin were measured in healthy volunteers and compared with those achieved with standard doses of ceftazidime, piperacillin and gentamicin, given alone or in combination. Five strains of each of four enterobacterial species were included in the study. Bactericidal titres 1 h after infusion of ciprofloxacin exceeded 1:16 for Escherichia coli, Klebsiella pneumoniae, Proteus vulgaris and Enterobacter cloacae. While ceftazidime produced higher peak bactericidal titres against the Enterobacteriaceae, piperacillin was less effective than ciprofloxacin against three of the four enterobacterial species tested. Among the combinations, only piperacillin/gentamicin showed synergistic activity against some strains. Studies of bacterial killing kinetics again confirmed the high bactericidal activity of ciprofloxacin for the Enterobacteriaceae. The combination of ciprofloxacin with gentamicin resulted in more rapid killing of some strains of Klebsiella pneumoniae and Proteus vulgaris.

Adult↗
PubMed1985

Neoplastic pathology of oncogenic osteomalacia/rickets.

Reported are two cases of oncogenic osteomalacia, each caused by a small mesenchymal tumor, with detailed assessment of the tumors by light microscopy, electron microscopy, and immunohistochemistry. One tumor was a primitive mesenchymal tumor with prominent giant cell and vascular components, and the second resembled the giant cell variant of soft parts chondroma. Osteoclast-like, multinucleated giant cells and vascularity were prominent features in both tumors. Although the literature documents a histologically heterogeneous group of tumors as causing this syndrome, most have multinucleated giant cells and/or extensive vascularity. The high incidence of these two histologic features in this group of tumors suggests that either or both may be related to the pathogenesis and/or metabolic consequences of oncogenic osteomalacia/rickets.

Adult↗
PubMed1985

Oncogenic osteomalacia: strange tumours in strange places.

Two patients presented with hypophosphataemic osteomalacia and were subsequently found to have small tumours unusual histopathology and location causing the osteomalacia. Each tumour was found after an intensive search for occult masses. Studies of vitamin D metabolism and renal tubular function before and after surgery yielded further insight into the pathophysiology of oncogenic osteomalacia. These cases demonstrate that microscopic quantities of tumour are capable of causing the syndrome and further illustrate the high index of suspicion often necessary to locate causative tumours in patients with hypophosphataemic osteomalacia.

Adult↗
PubMed1985

[Computer management of the data of automated perimetry using Octopus 2000 R].

Current perimetry involves automated, static and punctual procedures, which permit the examiner to obtain a numerical value of the sensibility concerning the points tested. Besides its precision and its reliability, perimetry can be used in data processing management due to the characteristic of easy duplication of the examinations. We use a micro-computer which is seperate from the Octopus 2000 R (Apple IIc) and the disc (OmnisII) to process the files. The study is composed of the following areas: the storage and the data processing of patient files, the transformation of numerical data a graphics display, the study of the percentage of loss of surface according to the decibel of sensibility. The data processing of files improves storage according to the criteria defined by the examiner and helps avoid inconvienent research. The graphic transformation of numerical data into isopteres of chosen sensibility improves the definition of the zones of intermediate sensibility. The calculations of the percentage of loss of surface according to the decibel of sensibility allows the appreciation of the size of defects based on depth and quantification. It is also easy to make the comparison between the two fields.

Aphakia, Postcataract↗