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Biomedical subjects

R Levy

Publications and source records attributed to R Levy.

At least 451 records · Page 25Linked to original sources
PubMed1991

Cytokeratin polypeptide expression in a cloacogenic carcinoma and in the normal anal canal epithelium.

The aim of the present study was to explore the origin of cloacogenic carcinoma in the anal canal by immunohistochemical methods. We compared cytokeratin polypeptide expression of a cloacogenic carcinoma to normal and epithelia, to anal squamous cell carcinoma and to basal and squamous cell carcinoma of the skin, using a battery of monoclonal anti-cytokeratin, polypeptide-specific antibodies. Our results indicate that cloacogenic carcinoma expresses cytokeratin polypeptides similar to those of the basal layer of anal squamous epithelium, of the anal transitional zone epithelium and of a layer of basal cells in the anal glands. Thus we concluded that each of the above cell types may be the cell of origin of cloacogenic carcinoma.

Anal Canal↗
PubMed1991

Complexity of expression of intermediate filament proteins, including glial filament protein, in endometrial and ovarian adenocarcinomas.

The expression patterns of intermediate filament proteins of primary and metastatic endometrial (n = 18) and ovarian (n = 24) adenocarcinomas were analyzed by immunocytochemistry using a panel of specific antibodies and by gel electrophoresis of cytoskeletal preparations, followed by immunoblotting. All cells of all endometrial adenocarcinomas studied contained the "simple epithelial"-type cytokeratins (CKs) 8, 18, and (mostly) 19, with variable numbers of cells also positive for CK 7 and vimentin. In addition, most of these tumors contained individual cells or groups of cells that were positive for the stratification-related CKs 4, 5, 6, 13, 14, and 17. The latter CKs were often associated with squamous cell foci, but were also found in some single (nonsquamous) tumor cells, indicative of early stages of squamous cell differentiation. Ovarian carcinomas of various histologic types and grades contained predominantly CKs 7, 8, 18, and 19. Serous, endometrioid, and anaplastic tumors, but not mucinous and clear cell tumors, also contained minor amounts of stratification-related CKs in variable combinations, mostly including CK 4. In all tumor types except mucinous tumors, vimentin was consistently detected in variable proportions of tumor cells which, however, were rather low in anaplastic carcinomas. Surprisingly, glial filament protein was detected in a minor proportion (< or = 20%) of tumor cells in seven of 14 serous and endometrioid ovarian carcinomas and in three of 18 endometrial carcinomas. These different intermediate filament expression patterns of müllerian duct-type carcinomas, only partly related to the morphologic appearance of the specific type of tumor, might reflect the multipotentiality of differentiation of müllerian duct-derived epithelia. Cytoskeletal features of potential diagnostic value, especially in metastatic carcinomas, are discussed.

Adenocarcinoma↗
PubMed1991

Intracranial pressure waves and intracranial hypertension in rats with ischemic fulminant hepatic failure.

Brain edema and intracranial hypertension are a major cause of death in fulminant hepatic failure. We have shown that brain water measured in rats after hepatic devascularization (portacaval anastomosis followed in 24 to 48 hr by ligation of the hepatic artery) increases with the progression of encephalopathy. In this study, we examined whether intracranial hypertension develops in this model of fulminant hepatic failure. Using a fiberoptic pressure transducer, intracranial pressure rose from 3.3 +/- 1.1 mm Hg to 23.7 +/- 2.7 mm Hg (mean +/- S.E.M.) by the time the corneal reflex was lost; intracranial pressure was unchanged in control rats. Immediately after ligation of the hepatic artery, intracranial pressure was normal and remained stable until the last hours of the experiment, when it progressively rose, suggesting a loss of intracranial compliance. In addition, sudden and short episodes of marked increases in intracranial pressure (greater than 50 mm Hg) not related to seizure activity markedly decreased cerebral perfusion pressure. Internal carotid artery blood flow, an indirect measure of cerebral perfusion, decreased 29% +/- 12% by the end of the experiment. The time elapsed from ligation of the hepatic artery until loss of the corneal reflex (range 340 to 940 min) was related to the change in cerebral perfusion pressure, suggesting that an increase in systemic arterial pressure at the time of the initial rise in intracranial pressure may result in an increased length of survival. In this animal model, widely used to study the pathogenesis of hepatic encephalopathy, intracranial hypertension invariably appears in the terminal phase of the course. The development of intracranial pressure waves may be an indication that brain herniation is imminent.

Animals↗
PubMed1991

Interleukin-2 therapy for refractory and relapsing lymphomas.

Recombinant interleukin-2 (rIL-2) has been reported to be active in metastatic renal cell carcinoma and malignant melanoma. The purpose of this trial was to determine the efficacy and toxicity of rIL-2 administered in continuous infusion in patients with Hodgkin's disease (HD) and non-Hodgkin lymphoma (NHL). 21 patients with HD (4 patients), diffuse large-cell NHL (7) or low-grade NHL (10) in failure or relapse after multiple-conventional treatments were included in this trial. rIL-2 therapy consisted of an induction period of two cycles separated by 3 weeks of rest, and, in the absence of progressive disease or undue toxicity, a maintenance period of 4 monthly cycles. Each induction cycle comprised the continuous infusion of rIL-2: 18 x 10(6) IU/m2 per day on days 1-5 and days 12-16. Each maintenance cycle comprised the continuous infusion of rIL-2: 18 x 10(6) IU/m2 per day on days 1-5. Among the 21 treated patients, 5 (all of those with low-grade NHL) responded to the induction phase (1 complete response, 4 partial responses) and 2 patients had a mixed response. Conversely, no response was observed in patients with HD or large-cell NHL. The median duration of response was 4 months. rIL-2 administered as a continuous infusion was well tolerated and most patients received the full dosage, and management did not require intensive care. During the induction period, 2 patients experienced grade III cardiovascular or renal toxicity. During the maintenance period, rIL-2 had to be interrupted in 1 patient because of a myocardial infarction. This trial confirms the inefficacy of rIL-2 for the treatment of large-cell NHL and HD. Conversely, in low-grade NHL, rIL-2 activity needs to be explored by further studies. rIL-2 may have a place in the early phase of the disease, when the immune system is not compromised, as an adjuvant treatment in residual disease in order to improve the duration of response.

Adult↗
PubMed1991

[Spinal anesthesia with bupivacaine without glucose in the elderly: effect of concentration and volume on the hemodynamic profile].

This study aimed to compare the haemodynamic effects of two different glucose-free bupivacaine solutions is thirty patients aged more than 70 years (mean age 82 years) undergoing hip surgery under spinal anaesthesia. They were randomly assigned to two groups, group A to receive 2.5 ml of a 0.5% bupivacaine solution, and group B 10 ml of a 0.125% solution in normal saline. All the patients were therefore given the same dose of bupivacaine, 12.5 mg. Lorazepam (1 mg orally) was administered to all for premedication two hours beforehand. Those patients taking antihypertensive agents were given their last dose on the eve of surgery. Lactated Ringer's solution (500 ml) was infused to all before the spinal puncture. Systolic (Pasys), mean and diastolic arterial pressures, and heart rate, were recorded every minute before volume loading, and for 30 minutes after the start of the spinal anaesthesia. Ephedrine (3 mg every two minutes if required) was given whenever Pasys decreased by more than 30% of the pre-induction value. The upper level of sensory blockade was assessed by the pin-prick test, and the quality of motor blockade with the Bromage scale. The cephalad spread of the solutions was similar, as well as the haemodynamic profile in each group. The total dose of ephedrine required in each group was not significantly different. It may therefore be concluded that, in the elderly, the upper level of, and the haemodynamic changes due to, spinal anaesthesia do not depend on the concentration or the volume of glucose-free bupivacaine solution.

Age Factors↗
PubMed1991

Carcinoma of the lip: observations on its frequency in females.

Seventy-three patients with lip carcinoma were treated from 1970 to 1988 in the Otolaryngology Department of the Beilinson Medical Center. The most common histological type was squamous cell carcinoma which occurred in 68 patients; four tumours were basal cell carcinoma and one acinic cell carcinoma. Carcinoma of the lip is more frequent in males. Nevertheless, the frequency of carcinoma in females in our series was substantially higher than the average reported in the literature. Forty-nine patients were treated surgically and 24 patients were treated by irradiation. Analysis of the results among those treated by surgery and those treated by irradiation shows a difference in tumour local control which was statistically significant (p = 0.025). Surgical treatment is recommended because of the advantage of tumour margin assessment, avoidance of radiotherapy complications and rapid rehabilitation. Two rare cases of carcinoma of the lip in young patients (age under 20 years) are presented.

Adolescent↗
PubMed1991

Factors affecting survival in Alzheimer's disease.

Factors affecting survival of 178 patients diagnosed using NINCDS/ADRDA criteria for Alzheimer's disease were studied. All patients were drawn from the Camberwell Health Authority Area and so were a representative sample of subjects from a clinical old age psychiatry service. The mortality rate of the sample was 3.5 times that expected after adjustment for age. Younger subjects had a higher standardized mortality ratio than older subjects. The cumulative three-year mortality of the sample was 47%. Factors shown to be associated with a reduced survival included: increasing age, longer duration of illness, male sex, presence of physical illness, poor cognitive function, observed depression and absence of misidentification syndromes. Apraxia was a stronger predictor of early death than aphasia or dysmnesia.

Aged↗
PubMed1991

Multivariate clinical models and quantitative dipyridamole-thallium imaging to predict cardiac morbidity and death after vascular reconstruction.

Patients with peripheral vascular disease have a high prevalence of coronary artery disease and are at increased risk for cardiac morbidity and death after vascular reconstruction. The present study was undertaken to assess the value of 18 clinical parameters, of 7 clinical scoring systems, and of quantitative dipyridamole-thallium imaging for predicting the occurrence of postoperative myocardial infarction or cardiac death. Vascular surgery was performed in 125 patients. Thirteen postoperative cardiac events occurred, including 10 cardiac deaths and 3 nonfatal infarctions. Clinical parameters were not useful in predicting postoperative outcome. All 63 patients with normal scan results or fixed perfusion defects underwent surgery uneventfully, whereas 21% (13/62) of patients with reversible defects had a postoperative cardiac complication. By use of quantitative scintigraphic indexes we found that patients with reversible defects could be stratified into intermediate and high-risk subgroups with postoperative event rates of 5% (2/47) and 85% (11/13), respectively, despite intensive postoperative monitoring and antianginal medication. Thus in patients unable to complete a standard exercise stress test, postoperative outcome cannot be predicted clinically, whereas dipyridamole-thallium imaging successfully identified all patients who had a postoperative cardiac event. By use of quantification we found that patients with reversible defects can be stratified into an intermediate risk subgroup that can undergo surgery with minimal complication rate and a high-risk subgroup that requires coronary angiography.

Canada↗
PubMed1991

Neurological signs in Alzheimer's disease.

Neurological signs were assessed in 178 patients satisfying NINCDS/ADRDA criteria for Alzheimer's disease. A snout reflex was present in 41%, extrapyramidal signs in 12%, drug-induced extrapyramidal signs in 3%, myoclonus in 5%, and a history of epileptic fits in 3%. A grasp reflex, extrapyramidal signs and symptoms were associated with severe cognitive impairment. On CT scanning, extrapyramidal signs were associated with increased 3rd ventricular size and basal ganglia calcification, a grasp reflex with frontal lobe atrophy and a history of epilepsy with left temporal lobe atrophy. Lateral ventricular size was greater in patients developing a grasp reflex during a 12 month follow-up. Extrapyramidal signs and primitive reflexes were associated with a higher mortality.

Aged↗
PubMed1991

Effects of tetrahydroaminoacridine on liver function in patients with Alzheimer's disease.

Detailed liver function test analysis is reported for 30 patients with Alzheimer's disease who were treated with tetrahydroaminoacridine. Results show that a benign elevation of aspartate transaminase occurs in up to 50% cases, that the reaction can be a symptomatic one and that clinical hepatitis can occasionally result. Liver function test changes appear dose-dependent and normalize within 2-4 weeks of stopping the drug or of reducing the dose. Women appear more likely to develop hepatotoxicity than men. Rechallenge with THA in patients previously showing abnormalities in liver function shows that some patients are able to tolerate the drug a second time.

Aged↗
PubMed1991

Percutaneous drainage and serial magnetic resonance imaging in the diagnosis of symptomatic posttraumatic syringomyelia: case report and review of the literature.

A patient with high cervical tetraplegia with new-onset headaches and posttraumatic syringomyelia is presented. Percutaneous drainage of the syrinx resulted in a resolution of the headaches and collapse of the syrinx on follow-up magnetic resonance imaging (MRI). The return of the symptoms correlated with the re-expansion of the syrinx on MRI. The patient underwent syringopleural shunting with persistent resolution of the symptoms and collapse of the syrinx on MRI. The value of percutaneous drainage and serial MRI to determine the clinical significance of posttraumatic syringomyelia is discussed.

Adult↗
PubMed1991

Progression of cognitive impairment in Alzheimer's disease.

Change in cognitive function was assessed over 12 months in 110 patients over the age of 65 satisfying National Institute of Neurological and Communicative Disorders and Stroke and the Alzheimer's Disease and Related Disorders Association (NINCDS/ADRDA) criteria for "probable" Alzheimer's Disease. A highly significant deterioration in cognitive function was observed. Decline in cognitive scores was relatively normally distributed. Patients who died during the follow-up had more apraxia at entry to the study than survivors. A greater rate of decline was seen in patients whose parents suffered from dementia (but not in those where a sibling or other relative was affected), in subjects who had moderate dementia, and those who had been ill for less than 24 months. Age, age of onset, and the presence or absence of aphasia or apraxia had no influence on rate of progression. A cluster analysis revealed three patterns of decline.

Age Factors↗
PubMed1991

Clinical trials in Alzheimer's disease. A report from the Medical Research Council Alzheimer's Disease Clinical Trials Committee.

Recent advances in Alzheimer's disease imply a need for adequate clinical trials of new treatments which require careful design. The disorder is progressive and shows clinical heterogeneity. While large-scale trials of elderly subjects are appropriate in relation to assessment of drugs or other treatments designed to prevent progression of the disorder, the outcome measurements in such biological treatment trials require careful planning. Studies of individual patients are relevant for answering certain specific questions. Relatively short cross-over trial designs may be appropriate to some pharmacological studies. The choice of neuropsychological instruments for measuring change is critically important, particularly in excluding test/retest artefact and in avoiding floor and ceiling effects. Test scales designed for assessment of specific neuropsychological deficits, or forming part of standard IQ assessments are unlikely to prove robust. Tests can be selected and developed for individual patients, but generalisation of the results of such experiments to the disease as a whole is not inevitable. There is a need to develop psychological instruments for measuring change that are robust and relevant to the clinical problem of progressive dementia.

Aged↗
PubMed1991

A device to aid in the application of stereotactic headframes: technical note.

It is sometimes difficult to apply the headframes of stereotactic systems in awake patients who are lethargic or demented or in patients who are very sensitive to the discomfort of local anesthetic injection. A device for external stabilization of the stereotactic system during its application to the head is described. This device, a modification of the Somi brace, is easy to apply, allows for adjustment of the base ring in all planes and provides sufficient stability even in obtunded or uncooperative patients. This device simplifies and makes more precise the application of the stereotactic headframe and may be of considerable utility in stereotactic surgery.

Equipment Design↗