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Biomedical subjects

R Weintraub

Publications and source records attributed to R Weintraub.

At least 19 recordsLinked to original sources

Primary coronary angioplasty for acute myocardial infarction (the Primary Angioplasty Registry).

During a 14-month period, 6 experienced centers prospectively enrolled 271 patients into a registry in which percutaneous transluminal coronary angioplasty was the primary treatment for acute myocardial infarction. Patients age > 18 years who presented with ST-segment elevation on the 12-lead electrocardiogram were enrolled if symptom duration was < 12 hours and there was no proclivity for bleeding. An independent core angiographic laboratory processed the angiographic data. Of 271 patients giving informed consent, 245 (90%) were deemed anatomically suitable and underwent angioplasty therapy. Upon leaving the catheterization laboratory 98% of patients had achieved reperfusion; 92% had a residual visual stenosis < or = 50%. Emergency bypass surgery was required in 14 patients (5%) for either failed angioplasty (n = 3) or presumed life-threatening anatomy (n = 11). The in-hospital mortality rate was 4%, whereas the reinfarction rate was 3% and the stroke rate was 1%, with 1 intracranial hemorrhage and 2 embolic events. Bleeding requiring > or = 2 units of blood occurred in 46 patients (18%); 14 of these transfusions were related to coronary artery bypass surgery. Primary angioplasty is associated with a high reperfusion rate, low in-hospital mortality and few recurrent myocardial ischemic events. These results point to the need for a large-scale trial comparing angioplasty with thrombolytic therapy in the setting of acute myocardial infarction.

Aged↗

Evaluation of ventricular septal defect by transesophageal echocardiography: intraoperative assessment.

The miniaturization of transesophageal echocardiography (TEE) probes, together with the development of the capability for biplane imaging from the esophagus, have increased the use of TEE in pediatric cardiology. The aim of this study was to evaluate the TEE findings in patients with ventricular septal defect (VSD) before and after closure primarily by means of pediatric biplane probes. This study group included 69 patients who underwent VSD closure as an isolated repair or as a part of a definitive repair of a more complicated lesion. Ages ranged from 6 days to 15.6 years (median 1 year, 4 months), with operative weights ranging from 2.9 kg to 68 kg (median 10 kg). Preoperative and follow-up transthoracic echocardiograms (TTE) were also performed. Intraoperative TEE was performed without complication in all 69 patients. Preoperative results: (1) anatomic findings: Two muscular VSDs were detected by matrix TEE but could not be observed by TTE. A patient with preoperative TTE diagnosis of an ostium primum ASD was found to have atrioventricular (AV) canal by TEE. In three of six AV canal type VSDs, both TTE and TEE demonstrated left ventricular-right atrial shunting (2) aortic regurgitation associated with VSD: Aortic regurgitation as a result of right coronary cusp prolapse was detected in one of five supracristal VSDs in which the biplane or matrix TEE was used.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

Effects of adjacent surfaces of different shapes on regurgitant jet sizes: an in vitro study using color Doppler imaging and laser-illuminated dye visualization.

OBJECTIVES: The present study was designed to estimate the influence of different-shaped adjacent surfaces on regurgitant jets as assessed by color Doppler imaging and laser-illuminated dye optical visualization. BACKGROUND: Because color Doppler techniques provide real-time two-dimensional imaging of flow, the evaluation of valvular regurgitation by analysis of variance-encoded regurgitant jets by this method has been widely used in clinical studies. However, recent studies have demonstrated that color Doppler jet sizes are affected not only by several hemodynamic factors and instrument settings but also by the interaction between jets and adjacent wall surfaces. In clinical conditions, jets may interact with adjacent walls of variable shapes that might have different effects on the jet size. METHODS: An in vitro model was constructed consisting of a rigid, optically clear receiving chamber that had no outlet resistance and had a pulsatile pump ejecting through 1.5, 2.3 and 3.1 mm2 inflow orifices into the chamber. The surfaces were flat or smoothly and equally curved, convex and concave aluminum positioned at 0, 2 and 4 mm from and to the side of the inflow orifices. The pump was run with stroke volumes from 0.5 to 3.0 ml and with a pulse frequency of 70 beats/min. The echocardiographic and laser beams were aimed at the inflow orifice imaging jets perpendicular to the surfaces (vertical view) through the central plane of the jet flows. Maximal jet areas were measured by both color Doppler techniques and laser-illuminated dye visualization. RESULTS: Color Doppler study showed fair correlation between the jet areas and the stroke volumes (r = 0.83 to 0.99), but the jet sizes under different surface conditions were variable. All the surface jet areas at a jet-surface distance of 0 and 2 mm were smaller than free jet areas at the same stroke volume for both flat and convex surfaces (p < 0.001). Flow constraint by the concave surface resulted in the smallest jet areas (p < 0.001). The color Doppler jet areas on the curved surfaces were significantly smaller than the laser-illuminated dye visualization jet areas (p < 0.01 to 0.0001). However, at intermediate jet-surface distances (4 mm and sometimes 2 mm with higher velocity flows), jet interaction with the flat and especially with the convex surface resulted in larger jets. This effect was most pronounced on dye fluorescence studies because flow around these jets consisted mainly of low velocity vortical events with only partial surface adherence and these low velocity swirling flows were not well imaged by color Doppler technique. CONCLUSIONS: Our study suggests that the different-shaped adjacent surfaces with different degrees of flow alterations resulted in variable decreases in jet size and that color Doppler imaging could not encode and image the angled and low velocity swirling events well when jets flowed along the curved surfaces. These effects need to be taken into account when interpreting color Doppler images.

Analysis of Variance↗

Influence of the Coanda effect on color Doppler jet area and color encoding. In vitro studies using color Doppler flow mapping.

We studied surface adherence and its effects on color Doppler jet areas and color encoding in an in vitro model with a noncompliant receiving chamber into which a steady flow jet was directed parallel to either a straight or a curved surface adjacent to and 4 mm away from the inflow orifice (1.50 mm2) with the control condition being a free jet matched for flow rates and driving pressures. Jets were imaged perpendicular to the plane of the surface, the plane in which most clinical images of jet-surface interactions are obtained. Ten different flow rates ranging from 0.13 to 0.30 l/min were used. Surface-adherent jet areas were smaller than control jets for every driving pressure-volume combination (paired t test, p less than 0.01). Computer analysis of color Doppler images showed more green and blue (reverse flow) pixels on the surface side of the adherent jets than the control jets (p less than 0.05), suggesting that viscous energy loss and flow deceleration and reversal play a role in the jet-surface interaction. Analysis of variance demonstrated that linear regression slopes of flow rate versus jet area for surface jets were lower (slopes, 11-21 cm2/l/min; r = 0.95-0.97) than those for the control (slope, 33 cm2/l/min; r = 0.97) (p less than 0.0001). Surface adherence (Coanda effect) influences jet size and color encoding, causing smaller color Doppler jet areas and greater variance and reverse velocity encoding.

Coronary Circulation↗

Transesophageal echocardiography in infants and children with congenital heart disease.

TEE applications for children and infants with congenital heart disease are now clinically established and TEE is being used in most major pediatric cardiovascular centers. This technology has evolved to the point that it is capable of providing diagnostic quality imaging, even for small infants. With expanding technology and increasing experience, new and more sophisticated applications will be found for pediatric TEE.

Child↗

A prospective, placebo-controlled, randomized trial of intravenous streptokinase and angioplasty versus lone angioplasty therapy of acute myocardial infarction.

BACKGROUND: The value of routine administration of intravenous thrombolytic agents during percutaneous transluminal coronary angioplasty (PTCA) therapy of acute myocardial infarction (MI) has not been determined. Therefore, we prospectively randomized 122 patients with evolving MI to PTCA therapy with or without adjunctive intravenous streptokinase therapy. METHODS AND RESULTS: Patients with ECG ST segment elevation who presented within 4 hours of symptom onset, had no contraindication to thrombolytic therapy, and were not in cardiogenic shock were enrolled. They were treated immediately with intravenous heparin (10,000 units) and oral aspirin (325 mg) and randomized to treatment with placebo or streptokinase (1.5 M units) administered intravenously over 30 minutes. Patients then were taken immediately to the catheterization laboratory, and those with suitable coronary anatomy underwent immediate PTCA. Subsequent clinical course, serial radionuclide ventriculography, and 6-month repeat angiography were analyzed. A total of 106 patients were treated with PTCA. Use of PTCA was similar for placebo (92%) and streptokinase (83%) groups. Angioplasty was successful in 95% of patients, with no difference in placebo (93%) and streptokinase (98%) groups. Serial radionuclide ventriculography demonstrated no difference in 24-hour (52 +/- 12% versus 50 +/- 12%) or 6-week (51 +/- 12% versus 51 +/- 13%) ejection fraction values for placebo and streptokinase groups, respectively. Contrast ventriculography demonstrated improvement in immediate (54 +/- 12%) versus 6-month (60 +/- 15%, p < 0.05) values for the overall group. No differences in 6-month values were present (58 +/- 15% versus 62 +/- 15%, p = NS) for placebo and streptokinase groups, respectively. Coronary angiography was performed in 75% of the 90 patients eligible for restudy. Arterial patency was 87% at 6 months, and coronary restenosis was present in 38% of patients. No differences in chronic patency or restenosis were detected for the two treatment groups. Although adjunctive intravenous streptokinase therapy did not improve outcome, it did complicate the hospital course. Hospitalization was longer (9.3 +/- 5.0 versus 7.7 +/- 4.4 days, p = 0.046) and more costly ($25,191 +/- 15,368 versus $19,643 +/- 7,250, p < 0.02). Transfusion rate was higher (39% versus 8%, p = 0.0001) and need for emergency coronary bypass surgery was greater (10.3% versus 1.6%, p = 0.03) for the streptokinase-treated patients. CONCLUSIONS: Adjunctive intravenous streptokinase therapy does not enhance early preservation of ventricular function, improve arterial patency rates, or lower restenosis rates after PTCA therapy of acute MI. Hospital course is longer, more expensive, and more complicated. For these reasons, PTCA therapy of acute MI should not be routinely performed with adjunctive intravenous streptokinase therapy.

Adolescent↗

Immunohistochemistry and electron microscopy in Langerhans cell histiocytosis confined to the skin.

Four cases of benign Langerhans cell histiocytosis limited to the skin were studied. In all three self-healing cases (cases 2, 3, and 4) many dense bodies, myelin bodies, and worm bodies were found. In one chronic case (case 1) none of these was identified. In all four cases, in addition to CD1, HLA-DR, and S-100 stains, interferon-gamma and S-100 beta-subunit were positive in the dermal tumor cells. Both interferon-gamma and S-100 beta-subunits were negative in the normal epidermal Langerhans cells. A comprehensive literature review yielded 87 cases of skin-limited Langerhans cell histiocytosis. These cases could be subgrouped into three categories: (1) those that resolved spontaneously, (2) those that responded to therapy and had no recurrence, and (3) those with persistent or recurrent lesions, not responding to therapy but still limited to the skin.

Aged↗

Focal dermal hypoplasia with an initial inflammatory phase.

We report a case of focal dermal hypoplasia with an initial inflammatory phase. Although our patient had dark red macules and papules and red linear atrophic lesions at birth, her lesions were somewhat faded at 3 months of age and had become yellowish before 5 months of age. Histologic examination of lesions at 3 months of age showed marked edema in the papillary dermis, mononuclear cell infiltration, a prominent fibroblastic population, and a large cluster of dermal lipocytes, suggesting an association between the inflammation and the development of dermal adipose tissue.

Dermatitis↗

High aluminium content of infant milk formulas.

The aluminium content of several commercially available infant milk formulas was measured by electrothermal atomic absorption spectrometry. Results were compared with those for fresh breast milk, cow's milk, and local tap water. Differences in aluminium concentration of greater than 150-fold were found, with the lowest concentrations in breast milk.

Aluminum↗

In vivo coronary angioscopy.

The feasibility of in vivo coronary angioscopy was tested utilizing a 1.8 mm angioscope in vessels where blood had been replaced by optically clear liquids, including a new perfluorocarbon emulsion. After trials in postmortem canine and human coronary arteries, in vivo intraluminal visualization was accomplished in the dog with a catheterization technique and in patients during open heart surgery. The results demonstrate the feasibility and potential clinical usefulness of direct visualization of intravascular anatomy and disease, analogous to endoscopy of other organ systems.

Animals↗

Ultrasonic visualization of the posterior thoracic aorta in long axis: diagnosis of a saccular mycotic aneurysm.

A saccular aneurysm arising from the descending thoracic aorta was identified ultrasonically in a 60-year-old man with a subsequent pathologic diagnosis of a Listeria monocytogenes mycotic aneurysm. A cross-sectional scanning technique, which permitted visualization of the descending thoracic aorta in long axis, demonstrated a 3 X 5 cm relatively echo-free mass between the heart and the aorta. A communication between the mass and the aorta established the diagnosis of an aneurysm.

Aneurysm, Infected↗

Viral infections.

In summary, viral infections of the skin that occur at adolescence include those typical of childhood and those associated with sexual maturity. Herpes simplex Type II, molluscum contagiosum, and venereal warts, diseases that have shown a marked increase, are in the latter group. Certain diseases, such as rubella, herpes simplex, varicella, and condylomata acuminata, which may lead to laryngeal papillomas, are particularly important because of their effects on the newborn infant. The epidemiological pattern of viral infections changes, and new viruses gain prominence while others fade in importance as causes of disease. Because of this, we can expect new viral entities and changes in earlier ones.

Adolescent↗

Mechanical circulatory support in postoperative cardiogenic shock.

A 38-year-old white woman had cardiogenic shock after elective mitral valve replacement and was unresponsive to pressor drugs and intra-aortic balloon counterpulsation. A left ventricular assist device (left ventricle to ascending aorta) was implanted 16 hours after the initial operation and provided circulatory support for 8 days. Improvement in the patient's own cardiac performance was documented, and there were no complications attributable to the assist device. However, intercurrent medical problems resulted in clinical deterioration on the fifth day after operation, and the patient died 8 days after operation. The findings in this patient suggest a potential role for this left ventricular assist device in future cases of acute, intractable, but potentially reversible myocardial failure.

Acute Kidney Injury↗