Biomedical subjects

E F Bernstein

Publications and source records attributed to E F Bernstein.

At least 73 records · Page 4Linked to original sources

PubMed1991

Noninvasive evaluation of vertebrobasilar insufficiency.

The diagnosis of vertebrobasilar insufficiency (VBI) is a clinical challenge because its manifestations are subjective and difficult to quantify. We evaluate 61 patients with the clinical diagnosis of VBI and 30 control patients with other medical problems. We used duplex scanning to study the extracranial carotid, vertebral, and subclavian arteries, and a 2-MHz transcranial Doppler (TCD) to examine the intracranial vertebral and basilar arteries. Extracranial lesions were more common in VBI patients than among controls, including stenosis of the subclavian artery with and without subclavian-vertebral steal and stenosis of the vertebral artery. Intracranial abnormalities identified in the vertebrobasilar circulation included stenosis and occlusion of the intracranial vertebral artery and basilar artery steal. Overall, significant lesions were detected in 32.8% of VBI patients and 3.0% of controls (P less than 0.05). Systolic artery velocity (cm/sec) in the extracranial vertebral artery was higher in controls (65.9 +/- 23.3) than in VBI patients who had no evidence of vertebrobasilar steal (43.0 +/- 17.4, P less than 0.05). Patients with a steal mechanism had an intracranial vertebral artery systolic velocity of 90.0 +/- 38.9, compared with 53.0 +/- 15.0 in controls (2P less than 0.050). Intracranial vertebral artery systolic velocity was higher among VBI patients with significant carotid artery disease (greater than 50%, 76.7 +/- 28.8) than in those with less severe disease (less than 50%, 47.3 +/- 13.8, P less than 0.05). Evaluation and quantitation of the vertebrobasilar circulation using both intra- and extracranial noninvasive studies may afford further insight as to the pathophysiology of vertebrobasilar insufficiency and provide a readily available, direct, and simple method of initial and serial assessment of VBI patients.

Arterial Occlusive Diseases↗

PubMed1991

Transcutaneous determination of tissue dihematoporphyrin ether content. A device to optimize photodynamic therapy.

Photodynamic therapy involves the use of light of appropriate wavelength to excite a photosensitizer resulting in tissue destruction. The photosensitizer dihematoporphyrin ether is selectively retained in tumors allowing for tumor destruction while sparing normal structures. Accessibility of skin tumors makes them well suited for photodynamic therapy. Tissue and tumor dihematoporphyrin ether content is estimated based on the amount of dihematoporphyrin ether administered. In our study, skin dihematoporphyrin ether content was measured in guinea pigs transcutaneously by a hand-held fluorometer and compared with dihematoporphyrin ether determinations done on skin biopsy specimens. Fluorometry was performed on guinea pigs receiving 0, 2.5, 5, 10, and 25 mg/kg of dihematoporphyrin ether. Transcutaneous measurements of skin fluorescence increased with increasing dihematoporphyrin ether dose and correlated well with skin dihematoporphyrin ether content as determined by extracting dihematoporphyrin ether from skin samples. Transcutaneous fluorescent measurements of guinea pigs given 0 and 2.5, 2.5 and 5, 5 and 10, and 10 and 25 mg/kg of dihematoporphyrin ether differed in a statistically significant manner. Transcutaneous fluorometric determination of dihematoporphyrin ether content and extraction of dihematoporphyrin ether from skin samples were able to reflect differences in dihematoporphyrin ether dosing and presumably skin dihematoporphyrin ether content. However, transcutaneous fluorometry provides an instantaneous estimate of tissue dihematoporphyrin ether without the need for a tissue sample. This may provide a clinical tool to predict more accurately the optimal light dose necessary to maximize photodynamic therapy.

Animals↗

PubMed1991

In vitro photodynamic treatment of normal and human papilloma virus-transfected keratinocytes with photofrin II and red light.

Photodynamic therapy involves the use of light of appropriate wavelength to excite a photosensitizer to result in tissue destruction. The photosensitizer dihematoporphyrin ether and red light were used to treat normal and human papilloma virus type 18-transfected keratinocytes in vitro. Although both cell lines were sensitive to treatment, normal keratinocytes retained more dihematoporphyrin ether and were more sensitive to photodynamic therapy than were transfected cells. In vitro data fail to show the selective retention of dihematoporphyrin ether reported elsewhere in the literature in papillomas and tumors. We did not find selective uptake or retention of dihematoporphyrin ether by human papilloma virus-transfected cells, despite previously published in vivo data to the contrary. Dihematoporphyrin ether retention and thus selective photosensitivity of papillomas in vivo is not caused by individual cellular differences in the processing of dihematoporphyrin ether. In addition, because in vitro results may not parallel in vivo results, both in vivo and in vitro models must be investigated in the study of phototherapeutic agents.

Antiviral Agents↗

PubMed1991

Real-time color duplex scanning after sclerotherapy of the greater saphenous vein.

A color real-time duplex scanner was used to scan the greater saphenous vein in 89 limbs of 55 patients to study the efficacy of prior greater saphenous vein sclerotherapy. The greater saphenous vein was insonated from the saphenofemoral junction to the knee to evaluate both reflux to a standardized 30 mm Hg Valsalva maneuver and evidence of greater saphenous vein obliteration by sclerotherapy. These data were correlated with the number of sclerosing injections used (mean, 1.8; range, 1 to 6), time from the last injection (mean, 27.5 mo.; range, 3 to 55 mo), and concentration of injectant used (0.5% to 3% sodium tetradecyl sulfate). Fifty-one of 89 injected limbs (57%) demonstrated reflux through the saphenofemoral junction, and reflux down the more distal greater saphenous vein was found in 67 of 89 injected limbs (75%). Greater saphenous vein obliteration was noted in only 18 of 89 injected limbs (20%); two were totally obliterated, and 16 were partially obliterated. The greater saphenous vein was obliterated in 6% below a refluxing saphenofemoral junction and in 40% below a nonrefluxing junction. A greater saphenous vein obliteration rate of 9% was found with a refluxing greater saphenous vein, and 50% in a nonrefluxing greater saphenous vein. Femoral vein reflux was identified in 11 of the 110 limbs (10%) and in every case was associated with both saphenofemoral junction and greater saphenous vein reflux. We noted a trend toward more successful results with more concentrated injectate (3% sodium tetradecyl sulfate). Fifty percent of patients reported improvement in symptoms.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1990

Utility of computed tomography for surveillance of small abdominal aortic aneurysms. Preliminary report.

To assess the ability of computed tomography to predict the potential for expansion of small abdominal aortic aneurysms, we analyzed the computed tomographic scans of 30 patients who had two or more abdominal computed tomographic scans at least 6 months apart between 1979 and 1989. Clinical variables and 10 defined objective characteristics of computed tomography were evaluated. Twenty-five men and five women with abdominal aortic aneurysms ranging from 30 to 64 mm (mean, 45 mm) were followed up with serial computed tomographic scans for a mean (+/- SE) of 26 +/- 3 months. In 19 patients, enlargement of aneurysm diameter of 3 mm or more on serial computed tomographic scans was noted, whereas in 11, there was little or no expansion. Of the clinical variables studied, only serum cholesterol correlated with an increased risk of expansion. Thrombus area, measured by computed tomography, was 7.3 +/- 0.9 cm2 in enlarging aneurysms vs 4.3 +/- 0.9 cm2 in stable aneurysms. Based on these preliminary data, we conclude that computed tomography may provide valuable information about the likelihood of future expansion of small abdominal aortic aneurysms.

Adult↗

PubMed1990

The natural history of amaurosis fugax with minor degrees of internal carotid artery stenosis.

The natural history of amaurosis fugax with hemodynamically insignificant degrees of internal carotid artery stenosis is uncertain. Seventy-three patients over age 40 who presented with amaurosis fugax without obvious cause and had ipsilateral stenoses of 50% or less with carotid duplex scanning were followed for a mean period of 35.5 months (range 3-110) without surgical intervention. At the initial vascular laboratory duplex evaluation, 35 patients had normal arteries (47.9%), 29 had minor (0-19%) stenoses of the ipsilateral internal carotid arteries (39.7%), and 11 had 20-50% stenosis (15.1%). Four patients with 0-19% stenosis and one patient with 20-50% stenosis experienced a subsequent stroke or permanent ipsilateral blindness. When analyzed by life-table format, stroke, blindness, and early death were more frequent in patients with minor degrees of stenosis than in those with normal arteries. Investigations in all patients with amaurosis fugax should be aimed at identifying whether the symptoms are explained by arteriosclerotic, systemic, collagen, cardiac, hematologic, or ophthalmologic disease. When no other etiology is found, and localized carotid bifurcation atherosclerosis of even modest degrees is identified, an atheroembolic etiology should be considered.

Aged↗

PubMed1990

Role of transcranial Doppler in carotid surgery.

Transcranial Doppler is a method for visualizing the intracranial circulation that has applications to the preoperative investigation of cerebrovascular disease. Estimations of the adequacy of collateral circulation around the circle of Willis may be made. In addition, the method may be used for intraoperative monitoring during carotid, cardiac, or neurosurgical procedures.

Arterial Occlusive Diseases↗

PubMed1990

Does carotid restenosis predict an increased risk of late symptoms, stroke, or death?

The identification of carotid restenosis as an unexpected late complication of carotid endarterectomy has prompted concerns regarding its importance as a source of new cerebral symptoms, stroke, and death. To investigate these concerns, we analyzed a consecutive series of 507 patients undergoing 566 carotid endarterectomies, each documented as technically satisfactory. Post-operative duplex Doppler examination data at 3 days, 1, 3, 6, 12 months, and annually thereafter in 484 arteries (85.5%) permitted classification of these arteries according to the most severe degree of postoperative stenosis: normal (n = 306); 1% to 19% (n = 89); 20% to 50% (n = 40); more than 50% (n = 49, including 8 occluded). The incidence of more than 50% restenosis was 14.5% in female and 7.7% in male patients (p = 0.003). Life table analyses to 10 years revealed a significantly greater life expectancy among those with restenosis (p = 0.05). Stroke was also less likely in patients with restenosis, although this difference did not reach statistical significance. When survival and stroke were both endpoints, the likelihood of patients with more than 50% restenosis remaining alive and stroke free was also greater than the less than 20% stenotic group (p = 0.03). Thus patients with carotid restenosis were less likely than patients with normal postoperative scans to have late symptoms, stroke, or early death.

Carotid Artery Diseases↗

PubMed1990

Comparison of transcranial and cervical continuous-wave Doppler in the evaluation of intracranial collateral circulation.

Adequate intracranial collateral circulation reduces risk of stroke in carotid artery surgery. To evaluate their relative accuracies in assessing intracranial collateral blood flow, we prospectively compared transcranial Doppler and continuous-wave Doppler of the cervical carotid arteries combined with compression of the common carotid artery in 28 consecutive patients before carotid endarterectomy. Ten healthy volunteers served as controls. Three patients (11%) were excluded from compression of arteries because of diffuse disease in the common carotid artery. A total of 199 compressions were performed without complications. Lack of a suitable transtemporal window precluded the performance of transcranial Doppler in three patients (12%). The anterior communicating artery was identified in all the normal volunteers and 80% of patients by both methods. The posterior communicating artery was identified by both methods in 16 of 20 attempts in controls. Continuous-wave Doppler identified the posterior communicating artery in 30 of 50 attempts in patients; transcranial Doppler identified the posterior communicating artery in 20 of 44 attempts in patients (p greater than 0.5). Detection of intracranial collaterals correlated with intraoperative carotid artery back pressure measurements in 23 of 25 patients (92%). We conclude that continuous-wave Doppler of the extracranial arteries combined with common carotid artery compression is a safe and easy way to detect intracranial collaterals, with an accuracy equivalent to transcranial Doppler.

Adult↗

PubMed1990

Response of black and white guinea pig skin to photodynamic treatment using 514-nm light and dihematoporphyrin ether.

Differences in skin pigmentation may significantly affect light penetration during photodynamic therapy. This study evaluated the effect of skin pigmentation on dermatotoxic reaction to photodynamic therapy utilizing the photosensitizer dihematoporphyrin ether. Black and white guinea pigs were given 10 mg/kg of dihematoporphyrin ether, depilated, and treated 48 hours after injection with 30 mW/cm2 of 514-nm light. Eschar formation was observed on white skin at an average light dose of 26 J/cm2, whereas black skin showed similar changes at 58 J/cm2. Microscopically, superficial necrosis corresponded to the gross changes noted. Our results agree with data describing the difficulty of treating pigmented lesions such as malignant melanoma with photodynamic therapy. This further suggests that higher light doses may be required to treat superficial lesions and produce skin photosensitivity in dark-skinned individuals.

Animals↗

PubMed1990

Propagation of deep venous thrombosis identified by duplex ultrasonography.

To investigate the efficacy of anticoagulation in preventing continuing thrombosis, we prospectively evaluated 24 patients with acute deep venous thrombosis using duplex ultrasonography. All patients were hospitalized with conclusive ultrasonic evidence of deep venous thrombosis identified in one of four levels: I, calf only; II, calf-popliteal; III, calf-popliteal-femoral; or IV, calf-popliteal-femoral-iliac. Duplex scans were obtained on admission and on three subsequent occasions during therapy. Progression of thrombosis was defined as advancement of thrombus to the more proximal venous level. Demographic data, symptoms, risk factors for deep venous thrombosis, physical findings, anticoagulation regimens, and hematologic variables were ascertained. Adequacy of anticoagulation was defined as elevation of baseline activated partial thromboplastin time by 150%. Nine patients (38%) had progression of thrombosis, and 15 (62%) had stable or improving duplex scans. Progression occurred as follows: I----II (2), I----III (2), II----III (1), and III----IV (4). Of the demographic and clinical variables examined, only smoking correlated with progression of thrombus (p = 0.04). Average heparin dose in the stable group was 1214 +/- 294 units/hr and 1122 +/- 248 units/hr in the group that progressed (p = 0.8): activated partial thromboplastin time was 45.6 +/- 7 seconds in the stable group and 49.8 +/- 9 seconds in the progression group (p = 0.7). Nine patients in the stable group had consistently adequate anticoagulation, whereas six did not; six in the progression group were consistently anticoagulated, and three were not. Two patients (one with stable thrombus and one with progressive thrombus) suffered nonfatal pulmonary emboli. Clot progression as determined by duplex scanning did not predict acute complications of deep venous thrombosis.

Adult↗

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 CHAT classification of stroke.

Current terminology for clinical episodes relating to stroke is inconsistent and unclear, does not permit inclusion of data regarding the location and magnitude of extracranial and intracerebral arterial disease, does not coincide with existing classifications in Europe, and characterizes a hemispheric entity only, as opposed to a global description including prior symptoms in both hemispheres. A new classification system (CHAT) has been designed to deal with these problems, including the current clinical presentation, historical clinical episodes, the site and pathologic type of arterial disease, and information regarding abnormalities of the brain. Using this system, a retrospective review of 480 consecutive carotid endarterectomies is presented, demonstrating the advantages of the CHAT classification. Data include a significant difference in the probability of survival after carotid endarterectomy for asymptomatic stenosis in patients with prior symptoms on the opposite side, as well as a significant difference in the probability of stroke-free survival between patients with amaurosis fugax and those with prior carotid cortical symptoms (TIAs) as the presenting clinical condition. The CHAT classification is suggested as a significant advance in the reporting of all surgical cerebrovascular disease experience, and has particular implications for the current randomized trials between medical and surgical therapy for carotid artery disease.

Actuarial Analysis↗

PubMed1988

Hydroxyl radical production by stimulated neutrophils reappraised.

Release of active oxygen species during the human neutrophil respiratory burst is thought to be mandatory for effective defense against bacterial infections and may play an important role in damage to host tissues. Part of the critical bacterial and host tissue damage has been attributed to hydroxyl radicals produced from superoxide and hydrogen peroxide. Because of the short life time of the very reactive hydroxyl radical, direct study of hydroxyl radical production is not possible; therefore, indirect detection methods such as electron spin resonance (ESR) coupled with appropriate spin-trapping agents such as 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) have been used. Superoxide production during the oxidative burst has been unambiguously demonstrated. Recent reports claim that hydroxyl radicals are not made during neutrophil stimulation and offer as an explanation the presence of granular components that interfere with hydroxyl radical production. When using the spin-trap agent DMPO, absence of the relatively long-lived adducts DMPO-OH and DMPO-CH3 has been assumed to be prima facie evidence for lack of hydroxyl radical participation. We show that high superoxide flux produced during stimulation of human neutrophils rapidly destroys both DMPO-OH and DMPO-CH3. In accord with previous implications, our results provide an alternative explanation for the absence of .OH adduct in spin-trapping studies and corroborate results obtained using other methods that implicate hydroxyl radical production during neutrophil stimulation.

Cyclic N-Oxides↗

PubMed1988

Successful treatment of atypical sprue in an infant with cyclosporine.

Cyclosporine was used to treat a child with severe, atypical sprue that was unresponsive to diet, parenteral nutrition, and corticosteroids. Therapy with cyclosporine resulted in a prompt clinical, functional, and histologic recovery. Remission was maintained for 1 yr until the drug was discontinued, when there was a histologic relapse that responded to reinstituting drug therapy. Cyclosporine may provide effective therapy for patients with similar disease.

Celiac Disease↗

PubMed1988

Transcranial Doppler in the management of extracranial cerebrovascular disease: implications in diagnosis and monitoring.

Transcranial Doppler (TCD) insonation permits quantitative noninvasive evaluation of intracerebral arterial velocity. With the use of a 2 MHz Doppler through a transtemporal approach, middle cerebral artery blood velocity (MCA-V, centimeters per second) and major collaterals were measured in 96 patients, including 15 normal control subjects, 66 patients with extracranial cerebrovascular disease (ECCVD), and 15 patients with other medical problems without ECCVD. MCA-V was higher in control subjects (62.7 +/- 15.1) than in patients with ECCVD (45.0 +/- 16.3, p less than 0.05). There was a significant inverse correlation between MCA-V and the degree of internal carotid artery stenosis present by duplex examination. Twenty-three patients monitored during carotid endarterectomy had a mean MCA-V under anesthesia of 37.0 +/- 16.9, which decreased to 22.4 +/- 14.8 during cross-clamping (p less than 0.01). MCA-V during cross-clamping correlated directly with stump pressure (R = 0.87) and was higher when major collaterals were identified before operation by TCD than when none were seen (31.7 +/- 9.5 vs. 8.8 +/- 8.5, p less than 0.01). Shunt function was verified in all 11 patients shunted. Electroencephalographic changes occurred in four patients with an MCA-V of 14.7 +/- 8.5 compared with an average of 24.1 +/- 15.5 for patients with normal electroencephalograms. MCA-V increased from 46.6 +/- 21.2 before operation to 61.0 +/- 22.4 after carotid endarterectomy (p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1988

Suggested standards for reports dealing with cerebrovascular disease. Subcommittee on Reporting Standards for Cerebrovascular Disease, Ad Hoc Committee on Reporting Standards, Society for Vascular Surgery/North American Chapter, International Society for Cardiovascular Surgery.

The evaluation of clinical reports on vascular disease is often made difficult by variations in descriptive terms, clinical classification, and outcome criteria. In 1983 the Joint Council of the Society for Vascular Surgery and the North American Chapter of the International Society for Cardiovascular Surgery created the Ad Hoc Committee on Reporting Standards to address these problems and recommend solutions. Some general problems were addressed in the initial report dealing with lower extremity ischemia. This article concerns clinical standards for reports dealing with cerebrovascular disease, suggests a scheme for clinical classification, and recommends standardized reporting practices for grading risk factors, angiographic and other diagnostic findings, and the results and complications of therapeutic intervention.

Cerebrovascular Disorders↗

PubMed1988

The improving long-term outlook for patients over 70 years of age with abdominal aortic aneurysms.

During the past decade, selective criteria for elective surgery for abdominal aortic aneurysms have been refined based on natural history and aneurysm expansion information. Using these criteria, contemporary preoperative preparation and newer intraoperative technical adjuncts, 123 consecutive patients underwent elective resection with 1 death (mortality rate: 0.8%). These include all patients operated on with both elective and urgent aneurysms at this institution since 1978, with the exception of those with frank rupture. Most importantly, however, the 5-year life-table survival of all of these patients (average age: 71.3 years, range 46-96 yr) was 72%, including both hospital and late mortality rates. More than half of the patients were over 70 years old (78 cases), with no hospital deaths and a 5-year life-table survival probability of 67%. For those under 70 years of age at the time of operation, the 5-year life-table probability of survival was 79%. We believe that these accomplishments were a direct result of an aggressive policy of screening for and selectively treating coronary disease and carotid stenosis preoperatively and the utilization of such intraoperative adjuncts as routine Swan-Ganz monitoring, autologous blood transfusion, the cell saver, and the frequent use of the tube grafting (50%). Thus, with proper selection, the outlook for the patient over 70 years old with an elective abdominal aortic aneurysm resection now approaches that of the normal population (67% vs. 69%).

Age Factors↗