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Biomedical subjects

L Weiss

Publications and source records attributed to L Weiss.

738 records · Page 41Linked to original sources
PubMedDate not supplied

Low blood selenium levels in patients with cystic fibrosis compared to controls and healthy adults.

Frank clinical selenium deficiency has been described in cystic fibrosis (CF), and a relative deficiency has been proposed as contributing to the pathogenesis of the disease. Because of these possibilities, we investigated the relationship between overall nutritional status in CF with measures of selenium nutriture. Fifteen stable outpatients with CF (group I) were compared to 13 age-matched controls (group II) and 27 healthy adults (group III). Whole blood, plasma, and red blood cell selenium levels were reduced by 31%, 29%, and 33%, respectively, in CF patients vs controls (all p less than 0.001). In addition, both groups I and II showed significantly lower blood selenium levels than healthy adults (p less than 0.005). Nutritional assessment revealed CF patients to be undernourished, with significant decreases in serum albumin (p less than 0.025), weight-for-height deficit (p less than 0.01), and weight-for-age (p less than 0.025) vs controls. However, only the triceps skinfold (TSF) measurement correlated significantly with selenium status (r = 0.56: p less than 0.05 for whole blood selenium vs TSF). We conclude, based on the magnitude of decrement in blood selenium, that it is unlikely that selenium plays a significant primary pathogenic role in cystic fibrosis. However, these patients are at high risk for developing clinical selenium deficiencies. The measurement of blood selenium levels using appropriate age-matched normal standards should be mandatory in all CF patients with malnutrition, or in those requiring parenteral nutritional support.

Adolescent↗
PubMedDate not supplied

Reduced cardiac selenium content in the acquired immunodeficiency syndrome.

Selenium deficiency has been implicated in the pathogenesis of a dilated congestive cardiomyopathy in areas of China (Keshan disease) and in several patients on long-term total parenteral nutrition. Recently a clinically and pathologically similar cardiomyopathy has been described in AIDS. Since blood selenium levels are low in AIDS, we assayed cardiac selenium status by a spectrofluorometric method in eight AIDS patients at autopsy compared to nine age-matched, non-AIDS autopsy controls with histologically normal hearts. We found (mean +/- SD) a cardiac selenium level of 0.327 +/- 0.082 microgram/g dry weight in AIDS vs 0.534 +/- 0.184 microgram/g dry weight in controls (p less than 0.01; Student's t test). There were no significant differences between the groups for heart weight, serum CPK, or other laboratory parameters. No specific chest x-ray or electrocardiographic abnormalities were present. Histologically, all AIDS hearts were abnormal; mostly with mild degrees of muscle hypertrophy or fibrosis. Foci of myocytolysis and myocyte necrosis and fibrous replacement of myocytes and monocytic infiltration were present in two AIDS cases. We conclude that heart tissue in AIDS demonstrates a significant selenium deficit. These data provide a potential link between selenium deficiency and cardiomyopathy in AIDS.

Acquired Immunodeficiency Syndrome↗
PubMedDate not supplied

Successful treatment of diabetes in NOD mice with advanced disease by islet isografts following immunoregulation with Linomide (quinoline-3-carboxamide).

We have recently documented that oral Linomide (quinoline-3-carboxamide) prevents autoimmune insulitis, islet destruction, and diabetes in NOD mice treated at an early stage (5 wk of age) of the disease. In this report, we show that treatment of female NOD mice with advanced disease (age 23-24 wk) by syngeneic islet transplantation and oral Linomide administration results in prevention of graft insulitis and diabetes in the Linomide group up to 40 wk (diabetes at 40 wk: isograft recipients with Linomide n = 0 of 6; isograft recipients alone n = 5 of 6; p < 0.0001). The extent of protection from glucose intolerance by the combination of transplantation with Linomide was superior to that of Linomide alone [blood glucose (mean +/- SD) 60 min post-i.p. injection of 1 g/kg body weight glucose: Linomide plus isograft 6.7 +/- 1 mmol/L; Linomide alone 18.7 +/- 6.3 mmol/L; p < 0.0001]. Thus, Linomide should be considered a potential immunoregulatory modality in patients undergoing pancreatic islet or whole organ transplantation.

Adjuvants, Immunologic↗
PubMedDate not supplied

Care provided by VA mobile clinic staff during Northridge earthquake relief.

INTRODUCTION: From 25 January 1994 to 02 February 1994, staff aboard four Veterans Affairs Mobile Clinics treated Northridge earthquake victims. This study examined the types of conditions treated by Clinic staff during the disaster. METHODS: A descriptive case series using 1,123 ambulatory encounter forms was undertaken. Case-mix was assessed by classifying diagnoses into 120 possible diagnostic clusters. RESULTS: Forty-five percent of patients were infants or children and 60% were female. The primary diagnoses were characterized by acute conditions: 1) upper respiratory infection (34.6%); 2) stress reactions (11.9%); 3) otitis media (10.1%); and injuries (8%). Two-thirds of the infants and children either had an upper respiratory infection (46.4%) or otitis media (20.1%). Increasing age indicated an increased likelihood of stress and anxiety reactions. CONCLUSIONS: The results provide additional information for agencies involved in planning for and responding to disasters. Based on the types of conditions diagnosed at the VA mobile clinics (i.e., a high prevalence of acute conditions, including stress and anxiety reactions, and the large numbers of children), staff trained in primary care, mental health, and pediatrics should be considered for relief missions that begin several days after an event resulting in a disaster.

Adolescent↗
PubMedDate not supplied

New approaches for the prevention of rejection and graft-vs.-host disease in clinical bone marrow transplantation.

The two major barriers to successful allogeneic bone marrow transplantation (BMT) in animals and man are graft-vs.-host disease (GVHD) and the risk of graft rejection. GVHD is the result of alloreactivity of mature donor T-lymphocytes present in the graft-vs.-host tissues and can be completely prevented by pregraft depletion of T-lymphocytes. Graft rejection results from residual host immunocompetent lymphocytes that survive heavy chemoradiotherapy prior to allogeneic BMT. Host resistance to allograft cannot be eradicated even by conventional conditioning with high-dose cyclophosphamide (120 mg/kg) and lethal whole body irradiation (1,200 rad). In the present report we have utilized two new techniques to overcome GVHD and graft rejection following allogeneic BMT. GVHD can be prevented by a new monoclonal rat antihuman lymphocyte antibody, CAMPATH-1, which binds human complement, enabling donor serum to serve as the source of complement. Prevention of rejection of T-lymphocyte-depleted marrow allografts can be achieved by the application of total lymphoid irradiation (TLI) in addition to conventional chemoradiotherapy, prior to allogeneic BMT. TLI causes potent immunosuppression with minimal side effects. A combination of TLI for overcoming host resistance to allograft, and CAMPATH-1 for overcoming GVHD, leads to a relatively smooth posttransplant outcome with no evidence of GVHD and with no need for posttransplant immunosuppression.

Antilymphocyte Serum↗
PubMedDate not supplied

Metatarsus primus elevatus and the etiology of hallux rigidus.

One hundred twenty radiographs of the foot were evaluated for hallux abductus angle, lateral talometatarsal angle, and metatarsus primus elevatus position. Mean elevatus position of the first metatarsal above the second metatarsal was approximately 7.0 mm. First ray elevation was a consistent finding in all data groups studied, including controls. The presence of hallux abducto valgus or hallux rigidus did not affect the degree of first ray elevation present. The majority of radiographs studied lacked evidence of joint disease. Therefore, the common practice of evaluating radiographic elevatus as a surgical criteria to predict the possible development of hallux rigidus should be strongly discouraged.

Hallux↗
PubMedDate not supplied

Cell adhesion molecules: a critical examination of their role in metastasis.

It is proposed that the arrest of circulating cancer cells in the microvasculature is mediated by mechanical interlocking of the cancer cell and vessel surfaces, as distinct from the formation of adhesive bonds utilizing cell adhesion molecules. It is also proposed that the major role of cell adhesion molecules in metastasis occurs after cancer cell arrest, when linkage to the extracellular matrix, initially the subendothelium, and consequent signal transduction results in cancer cell proliferation which is the ultimate determinant of metastasis.

Animals↗
PubMedDate not supplied

Cardiovascular studies of phenylpropanolamine.

Phenylpropanolamine is found in a number of over-the-counter preparations commonly used for appetite control or as a cold remedy. Even though widely used, some questions still exist as to its effect on the cardiovascular system of man. Both anesthetized and unanesthetized adult beagle dogs were used in this study. In the unanesthetized conditioned dog, blood pressure and heart rate were measured using an inflatable tail cuff. In the first group, consisting of 12 dogs, phenylpropanolamine was given (0.0, 3.1, 6.25 and 12.5 mg/kg) via a stomach tube and the animals were followed for 300 minutes. Each dose of phenylpropanolamine was given to 4 groups made up of 3 dogs each. It produced dose-dependent increases in blood pressure and decreases of heart rate. Maximum changes were noted at 30 to 60 minutes, lasting for 3 to 5 hours. A second group of 9 unanesthetized dogs was given repeated oral doses of phenylpropanolamine (3 groups of 3 animals each). Doses of 3 mg/kg and 6 mg/kg, given orally, produced approximately the same increase in blood pressure and decrease of heart rate as previously observed. At 6 hours, these same doses of phenylpropanolamine produced little or no change in either parameter. At 24 hours after the first dose, however, the dogs responded in much the same manner as with the first administration of phenylpropanolamine. Control dogs given water did not exhibit any degree of tachyphylaxis. Dogs anesthetized with Na pentobarbital were given oral and intravenous doses of phenylpropanolamine (0.0-25 mg/kg). The overall response was like that observed in the unanesthetized preparation with the important exception that low doses (0.1-3 mg/kg) produced significant increases in both heart rate and blood pressure, while higher doses (6-25 mg/kg) resulted in a lesser overall effect. Six anesthetized animals were used to study the effects of phenylpropanolamine and norepinephrine on the cardiovascular function. Both the increase in blood pressure and left ventricular force of contraction, produced by the first dose of phenylpropanolamine, were markedly reduced or absent with the second administration of the drug. In addition, the classic blood pressure response to norepinephrine was likewise increased by prior administration of phenylpropanolamine.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
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Waldenström's macroglobulinemia with prominent splenomegaly and multiple immune disorders.

We report an uncommon case of Waldenström's macroglobulinemia with prominent splenomegaly associated with acquired C1 inhibitor deficiency, lupus anticoagulant and red blood cell autosensitization. Each of these immune abnormalities has been occasionally reported separately in patients with diverse B-cell lymphoid malignancies, but never before have they appeared simultaneously in the same patient. In this case, the pathogeny of the C1 inhibitor deficiency is questionable and may possibly be directly related to the IgM monoclonal gammapathy through protein-protein interactions, as occurs for lupus anticoagulant.

Autoimmune Diseases↗
PubMedDate not supplied

Effects of mechanical trauma and free-radical exposure on the membrane-integrity of Ehrlich ascites tumor cells.

During hematogenous metastasis, the majority of cancer cells entering the microcirculation are rapidly killed as a consequence of loss of membrane integrity. This is partially due to mechanical trauma associated with intramicrovascular cancer cell deformation, and possibly to the action of free radicals released by endothelial and other cells. In an in vitro analysis of these two modalities, we have studied the effects of mechanical (filtration) trauma and exposure to hydrogen peroxide on the surface membrane integrity of Ehrlich ascites tumor cells. It was shown that final concentrations of H2O2 down to 0.001%, and filtration through 10 microns Nuclepore each produced significant loss in surface membrane integrity. An additive effect was demonstrated between exposure to 0.001% H2O2 and filtration, but the additive effect was not detectable at 0.01%. Overall, the results indicate the feasibility of trauma due to mechanical deformation and exposure to free radicals, contributing to the inefficiency of the metastatic process.

Animals↗
PubMedDate not supplied

Vascular cross-sectional area in rat mammary tumours; influence of noradrenaline.

A double fluorescent staining technique for visualisation of blood vessels was applied to rat mammary tumours. Rats were exposed to noradrenaline or saline and the stained vascular area was recorded. In tumours exposed to noradrenaline, vascular staining was different from that in those exposed to saline, reflecting the possible closure of part of the vasculature in response to the drug.

Animals↗
PubMedDate not supplied

Effects of oophorectomy on interstitial fluid pressure, blood flow and vascularity in a rat mammary tumour.

Interstitial fluid pressure (IFP), tumour size, blood flow and vascularity were measured in dimethyl-benz-alpha-anthracene-induced rat mammary tumours after oophorectomy. IFP was measured in the tumours by the wick-in-needle technique, blood flow by the labelled microsphere technique and vascularity by fluorescence vascular staining. Tumour volume was determined by measuring two diameters. Oophorectomy resulted in a decrease in tumour volume preceded by a decrease in IFP, while no significant change was observed in total tumour blood flow. The vascular cross-sectional area seemed to decrease. Cell proliferation may be of importance for the high interstitial fluid pressure in this hormone dependent tumour. A reduced metabolic requirement in the regressing tissue, down-regulating the vascular capacity, may camouflage the influence of the reduced tissue pressure on blood perfusion.

9,10-Dimethyl-1,2-benzanthracene↗