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Biomedical subjects

A Murphy

Publications and source records attributed to A Murphy.

At least 109 records · Page 6Linked to original sources
PubMed1993

Neurofilament expression in human T lymphocytes.

The expression of intermediate filaments in normal cells is mainly determined by their embryonal developmental origin. Flow cytometry using monoclonal antibody RT97 demonstrated that neurofilament was detectable in the human HuT 78 T-cell line and on resting T lymphocytes. Expression was greatly increased on lymphocytes activated for 3 days with phorbol ester. Western blotting confirmed the presence of the 200,000 MW form of neurofilament in T lymphocytes. Stimulation of peripheral blood T cells with phorbol myristate acetate (PMA) or with anti-CD3 monoclonal antibodies resulted in a marked increase in detection of phosphorylated neurofilament on Western blotting. Stimulation of HuT 78 cells with anti-LFA-1 resulted in redistribution of neurofilament from a perinuclear spheroid core into dendritic processes. These data indicate that T cells activated through the T-cell receptor associated complex express an intermediate filament usually associated with neurally derived cells. The finding that neurofilament expression and organization are regulated by T-cell surface molecules suggests a role for this intermediate filament in T-cell function.

Blotting, Western↗
PubMed1990

Leukocyte function-associated antigen 1 (LFA-1) is a signaling molecule for cytoskeletal changes in a human T cell line.

The HuT 78/2 clone is a human T cell clone which has an activated phenotype. When this line was stimulated with immobilized antibody to LFA-1, the majority of cells developed dendritic processes. These processes were demonstrated to contain cytoskeletal elements including microtubules and intermediate filaments. Phorbol myristate acetate synergized with and prolonged this effect. Thus, the LFA-1 molecule may function as a signaling molecule for cytoskeletal reorganization in a human T cell clone.

Antibodies, Monoclonal↗
PubMed1990

Antinuclear antibodies in sera of patients with recurrent pregnancy wastage.

Four groups of women were studied to determine whether low-level antinuclear antibody titers are associated with a higher risk for pregnancy loss. Group A consisted of 30 patients with a history of unexplained fetal losses. Group B consisted of 30 women with "explained" fetal losses (e.g., uterine septum or luteal phase defect). Ages and number of losses were comparable between the women in groups A and B. Group C consisted of 61 healthy pregnant women. Group D involved 61 healthy nonpregnant women of reproductive age. In groups A and B, 40% and 53.3% of the respective patients had antinuclear antibody titers greater than or equal to 1:40. In groups C and D the frequencies of positive antinuclear antibody titers were 8.2% and 5.6%, respectively. This study demonstrates a high prevalence of low-titer antinuclear antibody-positive serum in patients with explained and unexplained pregnancy losses.

Abortion, Habitual↗
PubMed1990

Spectrophotometric quantitation of anchorage-dependent cell numbers using the bicinchoninic acid protein assay reagent.

A rapid and convenient method is described for the determination of the actual and relative number of adherent cells in tissue culture. The cell lines human melanoma C32, ATCC CRL 1585, mouse melanoma B16-F10, and pig epithelial LLC-PK1, suspended in Dulbecco's minimum essential medium containing no serum, were allowed to adhere to fibronectin adsorbed to wells of a 96-well microtiter plate. Nonadherent cells were removed by aspiration, wells were washed, and adherent cells were solubilized with 200 microliters of the bicinchoninic acid (4,4'-dicarboxy-2,2'-biquinoline) protein assay reagent. Plates were heated to 60 degrees C for 30 min and absorbances read at 562 nm using a microtiter plate reader. A linear correlation was observed between the number of adherent cells in the range 2-8 X 10(5)/ml cells added and the protein content of the adherent cells as measured by the BCA protein reagent. The assay procedure gave absorbance values in the range of 0.100 to 1.30 making the method highly sensitive and reproducible. Blank wells containing only coupled protein and no cells gave little or no absorbance. Cell adhesion was fibronectin specific since little or no cell attachment was observed when microtiter plates were coupled with bovine serum albumin. Similar results were obtained with other cell types such as platelets. These results indicate that measurement of total cellular protein using the BCA protein reagent can be a rapid and sensitive assay for the detection and quantitation of adherent cells.

Animals↗
PubMed1990

Effect of low-dose oral contraceptive on gonadotropins, androgens, and sex hormone binding globulin in nonhirsute women.

The effectiveness of a low-dose oral contraceptive (OC) in suppressing plasma levels of gonadotropins, ovarian, and adrenal androgens and stimulating sex hormone-binding globulin (SHBG) was evaluated prospectively in nonhirsute women. Thirty-three women ingested 35 micrograms of ethinyl estradiol and 1 mg of norethindrone beginning within day 1 to 5 of the menstrual cycle. Baseline levels of luteinizing hormone, follicle-stimulating hormone, total testosterone (T), androstenedione (A), dehydroepiandrosterone sulfate (DHEAS), and SHBG were obtained before ingestion of the OC and repeated after 3, 6 and, 9 months of OC use on day 1 to 5 of the OC "cycle". A significant suppression of gonadotropin levels is seen in nonhirsute women. Sex hormone binding globulin is consistently stimulated by the low-dose OC. A significant suppression of T and DHEAS is observed. No change was seen in levels of A. The demonstrated effects become evident at 3 months and are maintained at 6 and 9 months.

Adolescent↗
PubMed1989

The interaction of thrombospondin with platelet glycoprotein GPIIb-IIIa.

The interaction of human platelet thrombospondin (TSP) with human platelet glycoproteins GPIIb-IIIa was studied using a solid-phase binding assay. Polystyrene test tubes were coated with TSP, and 125I-labeled GPIIb-IIIa was added, allowed to bind, and the bound radioactivity was measured. After 90 min, the binding became time independent, and in most experiments, more than 10% of the exogenously added radioactivity was bound to the tube. Analysis of the bound radioactivity by polyacrylamide gel electrophoresis and autoradiography indicated that it was from labeled GPIIb-IIIa. Several lines of evidence indicate that the binding of GPIIb-IIIa to TSP was specific. (a) TSP immobilized on plastic or Sepharose bound 3-10-fold more GPIIb-IIIa than immobilized bovine serum albumin. (b) Addition of unlabeled excess GPIIb-IIIa reversed the binding of 125I-labeled GPIIb-IIIa to immobilized TSP. (c) Addition of EDTA inhibited the binding of GPIIb-IIIa to TSP by more than 90%, whereas addition of 1 mM CaCl2 and 1 mM MgCl2 potentiated the binding by more than 100%. (d) Monoclonal antibodies against TSP and GPIIb-IIIa inhibited the binding by 30-70% as compared with control and polyclonal anti-fibrinogen anti-serum. (e) A plot of GPIIb-IIIa bound versus GPIIb-IIIa added was best described as a rectangular hyperbola by regression analysis with half-saturation at 60 ng/ml GPIIb-IIIa. Similar results were obtained when labeled TSP was added to tubes coated with GPIIb-IIIa. These results show that TSP and GPIIb-IIIa can specifically interact in vitro and suggest that GPIIb-IIIa may function as a platelet TSP receptor during platelet aggregation.

Calcium↗
PubMed1989

The GPIIB-IIIa-like complex may function as a human melanoma cell adhesion receptor for thrombospondin.

The purpose of this study was to determine whether a heterodimeric complex immunologically related to the fibrinogen receptor could function as a thrombospondin (TSP) receptor in TSP-mediated cell-substratum adhesion of human melanoma cells. We found that polyclonal antibodies to the platelet GPIIb-IIIa complex, GPIIIa, and the human vitronectin receptor inhibited TSP-mediated cell adhesion by 63-68%. Immunoprecipitation of detergent extracts of 125I-surface-labeled melanoma cells using either anti-human platelet GPIIb-IIIa or anti-human vitronectin receptor antibody revealed the presence of a single heterodimeric complex, suggesting that both antisera recognize the same integrin receptor, GPIIb-IIIa-like antigen. Adhesion of cells to TSP is likely mediated through a region of the TSP molecule containing the arginine-glycine-aspartic (RGD) peptide sequence, since cell attachment to TSP was inhibited 50-66% in the presence of peptides containing RGD. These results strongly suggest that a GPIIb-IIIa-like/vitronectin receptor can serve as a cell binding site for TSP in mediating cell-substratum adhesion.

Antibodies, Monoclonal↗
PubMed1989

Mammographic localization and biopsy: the experience of a gynecologic oncology group.

From 1976 through 1986, two hundred eighty or 9% of all breast biopsies performed by a private gynecologic oncology group were for mammographically suspicious but occult breast lesions. Sixteen percent were found to be malignant. There has been improvement in mammographic techniques, and localization procedures have evolved to the current use of hooked-wire needles, which allow for the excision of smaller amounts of tissue and use of outpatient surgery facilities. Recently, the cancers encountered have been more often carcinoma in situ rather than invasive lesions. With the current increase in mammographic screening, there needs to be a continuing evolution in diagnostic modalities.

Adult↗
PubMed1989

Postoperative recuperation: relation to the extent of endoscopic surgery.

Ninety patients undergoing a total of 92 endoscopic procedures were assessed regarding their subjective recovery times, their delays in returning to their places of employment, the duration of analgesic use, and their inhospital stays. A significant association (P less than 0.05) between recuperation parameters and the extent of the intra-abdominal surgery at laparoscopy was observed. A weak association also was noted between the number of incisions performed, the duration of surgery, and postoperative recuperation. Nonetheless, even the most radical endoscopic procedures required considerably less recuperation time when compared with laparotomies. With the out-of-work period reduced 5- to 6-fold, obese individuals appeared to tolerate these procedures as well as their thin counterparts.

Abdomen↗
PubMed1989

Defective suppression in the autologous mixed lymphocyte reaction in patients with Crohn's disease.

T helper and suppressor cell control of autologous immunoglobulin production was measured in 14 patients with Crohn's disease (CD) using autologous B cells or monocytes to stimulate regulatory T-cell activity. A pronounced defect in suppressor cell function was observed in the patient group but not in matched controls irrespective of whether B cells or monocytes were used as the stimulus. This defect was observed for IgG, A and M. This defect was seen both in patients with active disease and with inactive CD suggesting the possibility that a primary regulatory defect might exist in this disease. The patient group displayed normal helper cell function.

Adolescent↗
PubMed1989

The infant whiplash-shake injury syndrome: a clinical and pathological study.

The cases of 13 infants (median age, 3 months) who sustained nonaccidental trauma were reviewed. All presented with profound neurological impairment, seizures, retinal hemorrhages, and intracranial subarachnoid and/or subdural hemorrhages. Of 8 infants who died, autopsy was performed on 6. No patient had a skull fracture, and only one had an extracalvarial contusion. Five of the 6 patients on whom autopsy was performed had injuries at the cervicomedullary junction consisting of sub- or epidural hematomas of the cervical spinal cord with proximal spinal cord contusions. The authors conclude that direct cranial trauma is not an essential element of the injury mechanism in young patients who sustain severe whiplash-shake injuries. In addition to the classic injuries reported to occur with the shaken-baby syndrome, hemorrhages and contusions of the high cervical spinal cord may contribute to morbidity and mortality.

Brain Injuries↗
PubMed1988

Renal artery stenosis: the use of duplex ultrasound as a screening technique.

Over an 18-month period, 44 patients with hypertension were referred for evaluation of the renal arteries by duplex Doppler ultrasound. Those patients referred were pre-selected in that they were either young, or suffering from accelerated hypertension. Eleven patients (12 arteries) were considered to have characteristics suggesting renal artery stenosis. Of the 11 patients, nine have submitted themselves for further evaluation by angiography and radionuclide renography. These further investigations have identified seven true positive and three false positive results. Criteria for duplex diagnosis of renal artery stenosis are presented and a possible role for duplex Doppler ultrasound as a screening tool for renal vascular hypertension is discussed.

Adolescent↗