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Biomedical subjects

M Stein

Publications and source records attributed to M Stein.

At least 271 records · Page 15Linked to original sources
PubMed1991

Tumor necrosis factor induction of urokinase-type plasminogen activator in human endothelial cells.

Vascular endothelial cells undergo morphological and functional changes at sites of cell-mediated immune responses which may serve to promote the pathogenesis of inflammation. These changes, described as "endothelial cell activation" can be invoked by a variety of cytokines which include interleukin I (IL-1), tumor necrosis factor (TNF), and lipopolysaccharide (LPS). We report here on the regulation of the plasminogen activator (PA) proteolytic system by human recombinant TNF alpha in short term cultures (less than 4 passages) of human umbilical vein endothelial cells (HUVECs). TNF alpha treatment of HUVECs enhanced the production of 55 kDa urokinase (u) PA activity and uPA antigen by fourfold, in a concentration dependent manner (5-100 U/ml), following a 24 h treatment as determined by PA zymography and micro-ELISA assays, respectively. This response was specific for uPA since, no change in extracellular tissue type PA activity and tPA antigen levels were noted under analogous conditions. A similar 4-fold increase in the de novo synthesis of [35S]-methionine radiolabeled uPA was observed by immunoprecipitation following a 24 h TNF treatment. The induction of uPA by TNF was inhibited by actinomycin D and cycloheximide implying the necessity of RNA and protein synthesis, respectively. The effect of TNF could not be prevented by the addition of IL-1 neutralizing antibodies. Therefore, it is unlikely that TNF acts through the induction of IL-1 secretion. Time course studies using PA zymography indicate that within 8 h after TNF exposure, a 2-fold increase in uPA activity above untreated basal levels was observed. Upregulation of extracellular uPA production in HUVECs following TNF treatment suggests yet a new aspect of cellular and interstitial PA regulation in endothelium during inflammation and angiogenesis.

Cells, Cultured↗
PubMed1991

SLE in Zimbabwean patients: a review of clinical and serologic features and evaluation of criteria for classification.

The clinical and serologic features have been reviewed in a group of 18 black Zimbabwean patients with SLE, a rare condition in this racial group. The relative merits of the preliminary and revised criteria for the classification of the SLE have been assessed. The prevalence of individual clinical criteria was essentially similar in this group when compared to a larger North American cohort. Minor variations were attributable to racial and environmental differences. Serologic tests were identified. The revised criteria had greater sensitivity for SLE than the preliminary criteria although this was not the case if individual serologic items were omitted. Clinically, SLE is a uniform condition when our cases are compared with those in other areas. In areas where the technology does not exist to perform specific serologic testing, the preliminary criteria with their greater dependence on clinical features still have a useful role when compared to the revised criteria with their greater dependence on serologic testing.

Humans↗
PubMed1991

Total-skin electron irradiation for cutaneous T-cell lymphoma: the Northern Israel Oncology Center experience.

Total-skin electron irradiation (TSEI) is effective and frequently used in the treatment of cutaneous T-cell lymphoma. A treatment technique has been developed at our center, using the Philips SL 75/10 linear accelerator. In our method, the patient is irradiated in a recumbent position by five pairs of uncollimated electron beams at a source to skin distance of 150 cm. This method provides a practical solution to clinical requirements with respect to uniformity of electron dose and low X-ray contamination. Its implementation does not require special equipment or modification of the linear accelerator, 19 of 23 patients (83%) with mycosis fungoides, treated by this method, achieved complete regression of their cutaneous lesions.

Adult↗
PubMed1991

[The light-cured composite CuRAY-FIL. A clinical and experimental animal study].

This article presents a animal study on 36 teeth by dogs without definite race. By the histological observation we cannot assess a damage of the pulp by application of CuRAY-FIL with a basic material. The clinical and REM observations after 11 and 24 months by 76 patients pointed out: CuRAY-FIL has a good colour stability and adhesion, however the claims on a optimal filling material for the restoration in the visible area are not accomplished in all points.

Acid Etching, Dental↗
PubMed1991

Variation in cuff blood pressure in untreated urban outpatients with mild hypertension in Harare, Zimbabwe--implications for the diagnosis of hypertension.

Duplicate measurements of BP were recorded at six visits in 32 male urban factory workers found to have raised BP (systolic blood pressure (SBP) greater than or equal to 160 mmHg or diastolic blood pressure (DBP) greater than or equal to 90 mmHg) at the initial visit). A systematic decrease in both SBP and DBP occurred over the first three visits. The BP at visits 4-6 was not significantly different. Most of the decrease in BP occurred between the first and second visit (mean SBP decreased 8.5 mmHg and mean DBP decreased 11.1 mmHg). After 6 visits 66% of subjects could be classified into clear clinical groups (normotensive 53.5%, hypertensive 12.5%) but in 34% the variation in cuff BP precluded classification. In these subjects prolonged observation or home BP monitoring may be required before initiating lifelong treatment.

Adult↗
PubMed1991

Human immunodeficiency virus-related connective tissue diseases: a Zimbabwean perspective.

Our clinical experience with patients in Zimbabwe suggests that an arthropathy may be a feature of HIV disease. This takes two forms: the first is a reactive arthropathy usually affecting the large, lower limb joints with no other clinical features of a connective tissue disease. The second form is seen in association with features of complete or incomplete Reiter's syndrome with involvement of large and small peripheral joints (having an asymmetric distribution). Although this arthropathy may been seen in association with HIV positive asymptomatic disease and often is the reason for first presentation at hospital, the majority of our patients have clinical features of persistent generalized lymphadenopathy, plus or minus features of constitutional illness (such as fever, weight loss, and diarrhea). A small percentage of our patients have arthropathy in association with secondary systemic infection. Other locomotor conditions have been observed, although their numbers are too small to determine whether or not they truly are related to HIV disease. In Zimbabwe there is no association between the development of HIV-associated arthropathy and the presence of HLA-B27.

Arthritis↗
PubMed1991

End-to-end versus end-to-side proximal anastomosis in aortobifemoral bypass surgery: does it matter?

The proximal anastomosis is still a controversial issue in vascular surgery. To compare end-to-end (EE) and end-to-side (ES) proximal anastomoses, the authors undertook a prospective study with 3 years' follow-up involving 120 patients, all of whom had aortobifemoral bypass. Fifty-one (42.5%) patients received the EE and 69 (57.5%) the ES anastomosis. The indications for surgery were abdominal aortic aneurysm (EE 51%, ES 0%; p less than 0.05), claudication (EE 33.3%, ES 53.6%; p less than 0.05) and critical ischemia (EE 15.7%, ES 46.4%; p less than 0.05). Patients in the EE group were older (mean age: EE 66.1 +/- 2.8 years, ES 60.9 +/- 1.1 years; p less than 0.05) and had more ischemic heart disease (EE 39.2%, ES 27.5%; p less than 0.05). Postoperative mean increases in transcutaneous oximetry (EE 15.5 +/- 3.9 mm Hg, ES 12.6 +/- 2.3 mm Hg) and the ankle-brachial pressure index (EE 0.34 +/- 0.05, ES 0.30 +/- 0.03) were not significantly different in the two groups. The operative death rate was higher for the EE group (EE 11.8%, ES 1.4%; p less than 0.05). Early thrombosis occurred in six patients, two in the EE group and four in the ES group. Computed tomography, done 1 year postoperatively in 95 patients, revealed two small (less than 3 cm) distal anastomotic dilatations, one in each group. At 3 years, cumulative survival and patency were similar in both groups. The authors conclude that the two anastomotic groups had very similar short- and long-term results, except for the operative death rate which was higher in the EE group.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1990

Modulation of spinach chloroplast NADP-glyceraldehyde-3-phosphate dehydrogenase by chaotropic anions.

Neutral salts enhanced the specific activity of chloroplast NADP-glyceraldehyde-3-phosphate dehydrogenase (D-glyceraldehyde-3-phosphate:NADP+ oxidoreductase (phosphorylating), EC 1.2.1.13) from spinach leaves. The ordering of the respective anions, according to the concentration for maximal stimulation, yielded the lyotropic (Hofmeister) series [SCN- (0.05 M), ClO-4 (0.08 M), Cl3CCO-2 (0.24 M), I- (0.35 M), Br- (0.6 M), Cl- (1.0 M)]; the more chaotropic the anion the less its concentration for maximal activation. Neither the NAD-linked activity of the chloroplast enzyme nor glyceraldehyde-3-phosphate dehydrogenases originating from cyanobacteria and rabbit muscle were stimulated by neutral salts. Chaotropic anions also enhanced the catalytic capacity of the chloroplast enzyme at concentrations lower than those required for the activation process. In the presence of 0.12 M NaBr the rate of catalysis was maximum whereas the highest conversion from the inactive to an active form was observed at 0.6 M NaBr. On the other hand, nonstimulatory concentrations of chaotropic anions lowered the concentration of ATP, Pi, and NADPH required for maximum stimulation of the specific activity (concerted hysteresis). On the basis that the enhancement of NADP-glyceraldehyde-3-phosphate dehydrogenase (and other chloroplast enzymes) by chaotropic anions paralleled the effect of organic solvents and reduced thioredoxin, it appeared that the modification of hydrophobic (intramolecular) interactions participates in the mechanism of light-mediated regulation.

Aldehyde Oxidoreductases↗
PubMed1990

Tumor necrosis factor mRNA localized to Paneth cells of normal murine intestinal epithelium by in situ hybridization.

Paneth cells in normal murine small intestine contain TNF mRNA that is readily detectable by in situ hybridization, unlike resident macrophages in lamina propria, which are negative. Northern blot analysis of whole tissue shows the presence of mRNA that has the same electrophoretic mobility as TNF mRNA from activated macrophages. A low level of TNF bioactivity, but no immunoreactivity, was detected in normal small intestine, and TNF production in resting Paneth cells appears to be post-transcriptionally controlled. Typical leukocyte surface membrane markers were not found on Paneth cells, but were expressed by the surrounding lamina propria macrophages. Paneth cells are thus epithelial cells with leukocyte-like secretory potential that may be important in intestinal physiology and pathology.

Animals↗
PubMed1990

Hierarchical pattern of mucosal candida infections in HIV-seropositive women.

PURPOSE: Candida is the most common cause of opportunistic mucosal infections in human immunodeficiency virus (HIV)-positive women. We had observed an apparent correlation between the severity of immunodeficiency and the site of mucosal candida infection. The current study was designed to determine whether significant correlations existed between the sites of mucosal candida infection and the degree of immunodeficiency, as determined by subsets of lymphocyte populations. PATIENTS AND METHODS: The subjects in this study are 66 HIV-seropositive women evaluated by members of the Brown University Acquired Immunodeficiency Syndrome (AIDS) Program during the 3-year period, September 1, 1986, through August 30, 1989. All patients had thorough clinical evaluations and relevant laboratory studies at defined intervals. All patients with CD4 lymphocyte counts below 0.2 X 10(9)/L received zidovudine therapy as soon as it became available. After July 1988, all patients with CD4 counts below 0.2 X 10(9)/L received prophylaxis against Pneumocystis carinii pneumonia. All patients were counseled about HIV infection, its modes of transmission, and the early symptoms of opportunistic infections. RESULTS: The longitudinal data demonstrated that candida often infected vaginal mucosa when there was no significant reduction in CD4 lymphocyte counts. Candida infection of the oropharyngeal mucosa was associated with highly significant reductions in CD4 lymphocyte counts. Esophageal candidiasis occurred only with advanced immunodeficiency associated with CD4 counts below 0.1 X 10(9)/L. CONCLUSIONS: Candida mucosal infections occur in a hierarchical pattern in women with HIV infection. Determination of the basis for the differences in susceptibility to candida of the vaginal, oropharyngeal, and esophageal mucosal surfaces will require further studies.

Adolescent↗
PubMed1990

Followup observations of operated male-to-female transsexuals.

We performed an in-depth interview to ascertain the psychosocial and functional status in 10 of 22 male-to-female transsexuals who underwent vaginoplasty from May 1985 to December 1988. Followup from 5 to 48 months was available for 14 patients. Our patients comprised a well educated, mostly employed, law abiding group with a low incidence of drug use. Most patients were able to develop strong support systems and showed a marked decrease in suicidal tendencies postoperatively. Functionally, the majority of the patients were able to lubricate the neovagina and have painless intercourse with a potential for orgasm. The cosmetic result was judged to be good, with no patient reporting being discovered of having had a prior operation by the sexual partner. We experienced a 21% rate of vaginal stenosis with 40% of these patients fully functional after a corrective operation.

Adaptation, Psychological↗
PubMed1990

Ethnic differences in cyclic AMP accumulation: effect on alpha 2, beta 2, and prostanoid receptor responses.

Platelet alpha 2- and lymphocyte beta 2-adrenergic receptor density and responsiveness and platelet responses to prostaglandin E2 (PGE2) were measured in black subjects and white subjects. Mean (+/- SEM) alpha-receptor density was greater in white subjects (248 +/- 29 versus 392 +/- 31 fmol/mg protein; p less than 0.005), whereas beta-receptor densities were similar (black subjects, 19.2 +/- 2.2 fmol/mg protein; white subjects, 15.2 +/- 1.4 fmol/mg protein). Basal platelet cyclic AMP levels (black subjects, 7.8 +/- 1.1 pmol/mg protein; white subjects, 14.5 +/- 2.4 pmol/mg protein; p less than 0.05) and PGE2-induced increases in platelet cyclic AMP levels were higher in white subjects (black subjects, 47.1 +/- 3.3 pmol/mg protein; white subjects, 65.5 +/- 3.4 pmol/mg protein; p less than 0.001). Basal lymphocyte cyclic AMP levels (black subjects, 1.2 +/- 0.3 pmol/10(6) cells; white subjects, 2.8 +/- 0.6 pmol/10(6) cells; p less than 0.05) and mean isoproterenol-induced cyclic AMP increases were also higher in white subjects (black subjects, 6.2 +/- 0.6 pmol/10(6) cells; white subjects, 8.5 +/- 0.8 pmol/10(6) cells; p less than 0.05). Responses to isoproterenol as fold stimulation of basal were not significantly higher in black subjects (8.51 +/- 0.97 versus 6.16 +/- 0.86 fold-stimulation of basal). Platelet responses to PGE2 as fold stimulation of basal (black subjects, 7.9% +/- 0.7%; white subjects, 8% +/- 1.3%) and alpha 2-receptor-mediated inhibition of PGE2 responses by UK-14304 (black subjects, 38.2% +/- 1.7%; white subjects, 40.6% +/- 2.3%) were also similar in the two groups.

Adult↗
PubMed1990

The association between HLA and rheumatoid arthritis in Zimbabwean blacks.

HLA-A, B, C, DR and DQ typing was done on 26 black Zimbabweans with rheumatoid arthritis and the respective antigen frequencies were compared with those in a group of 119 normal individuals from the same ethnic background. Only the DR4 antigen was significantly increased in frequency in the patients, confirming the association with this disease seen in other Black African populations.

Arthritis, Rheumatoid↗