Search PubMed⌕ Search

Biomedical subjects

J Smith

Publications and source records attributed to J Smith.

At least 1,081 records · Page 60Linked to original sources
PubMed1986

Partial plasma exchange in patients with AIDS and Kaposi's sarcoma. Plasmapheresis in AIDS.

Intensive plasma exchange was performed in seven male homosexual patients with AIDS and Kaposi's sarcoma. Serial 1.2 plasma volume exchange procedures were performed three times a week for six weeks. In five of the patients, plasma replacement included gamma globulin in the form of plasma (two patients), or an IV IgG preparation (three patients). No changes in the mean number of helper-inducer or suppressor-cytotoxic cells were noted during the treatment period or the weeks following completion of the last procedure. The mean mitogenic response of the patients' lymphocytes to PHA increased by 32.4% during the course of the plasmapheresis procedures (p less than .05), but returned to baseline over the eight weeks following treatment. Mitogenic responsiveness to PWM did not significantly increase during the course of treatment. No regression of Kaposi's sarcoma lesions was found in any of the patients treated.

Acquired Immunodeficiency Syndrome↗
PubMed1986

Dynamics of early T cells: prothymocyte migration and proliferation in the adult mouse thymus.

The object of this review has been to consider precursor cell migration into the normal adult thymus, using the mouse model. We have presented a series of experiments and discussed them in the context of other relevant experiments in the literature. The conclusions, qualified in the text, can be summarized as follows: There is a continual input of precursor cells into the normal undepleted adult thymus. The daily input of precursors under normal circumstances is very low (e.g. several per day). Once a precursor enters the pool of proliferating cells inside the thymus, its proliferation is limited to only several weeks. There is no permanent endogenous stem cell. There are a number of different precursor microenvironments in the thymus with different controls, since the kinetics of early (bone marrow-derived) and late (thymus-derived) precursors is quite different. All of these points require further analysis, and we have presented a minimal model as a basis for further experiment.

Adrenalectomy↗
PubMed1986

Comparative evaluation of four systems for determining susceptibility of gram-positive organisms.

A study was undertaken to compare four commercial systems for testing the antimicrobial susceptibility patterns of gram-positive cocci. The reference method was an agar dilution method. The systems evaluated were the MS-2 system (Abbott Diagnostics Div., Mississauga, Ontario), the AutoMicrobic system (AMS) (Vitek Systems, Inc., Hazelwood, Mo.) with the gram-positive susceptibility (GPS) card, the Sceptor system (BBL Microbiology Systems, distributed by Becton Dickenson, Canada Inc., Mississauga, Ontario), and the Micro-Media system (Beckman Instruments, Inc., Anaheim, Calif.). There was a greater than 98% essential accord (EA) between all test results and the reference method results when testing 134 isolates of Staphylococcus aureus. In testing 79 isolates of coagulase-negative staphylococci the EA was greater than 97% with all systems except the MS-2. In the MS-2 system only, 30% of tests were interrupted by the instrument because of insufficient growth in the control chamber. Excluding the Sceptor system, the EA was greater than 96% on testing 70 isolates of enterococcus. In testing 15 isolates of group B Streptococcus there was 91% EA with the AMS and Sceptor systems and only 71 and 88% EA with the MS-2 and Micro-Media systems, respectively. The new AMS GPS MIC card was tested against 29 methicillin-resistant S. aureus, 10 coagulase-negative staphylococci, and 9 enterococci, and it gave more accurate results than the earlier GPS breakpoint card. The Micro-Media and MS-2 systems did not reliably detect marginally methicillin-resistant S. aureus. The MS-2 was the least expensive system to operate on a cost per test basis ($3.59 Can.), whereas the Sceptor was the most expensive system ($5.29 Can.). The AMS ws the least labor intensive (0.9 min per test), and the Sceptor system was the most time consuming (2.9 min per test).

Anti-Bacterial Agents↗
PubMed1986

Growth factors suppress and phorbol esters potentiate the action of dibutyryl adenosine 3',5'-monophosphate to stimulate aromatase activity of human adipose stromal cells.

In previous studies, we observed that the stimulatory effect of (Bu)2cAMP on aromatase activity of human adipose stromal cells was markedly attenuated when fetal calf serum was present in the culture medium. To determine whether growth factors may be the inhibitors of (Bu)2cAMP-stimulated aromatase activity in serum, the effects of growth factors and phorbol esters on aromatase activity of human adipose stromal cells in monolayer culture were investigated. Epidermal growth factor (EGF), fibroblast growth factor (FGF), and platelet-derived growth factor (PDGF) were all without effect on aromatase activity when added by themselves, but markedly inhibited aromatase activity stimulated by (Bu)2cAMP. On the other hand, nerve growth factor, multiplication-stimulating activity, relaxin, and insulin had no effect on aromatase activity, either by themselves or in the presence of (Bu)2cAMP. Thus, EGF, PDGF, and FGF can mimic the inhibitory action of fetal calf serum on (Bu)2cAMP-stimulated aromatase activity of these cells. By contrast, none of these substances was capable of mimicking the effect of serum to facilitate the stimulatory action of dexamethasone on aromatase activity of these cells. The phorbol esters phorbol-12-myristate-13-acetate, phorbol-12,13-didecanoate, and phorbol-12,13-diacetate were also capable of facilitating the action of (Bu)2cAMP to stimulate aromatase activity, but had little or no action on dexamethasone-stimulated aromatase activity or when added by themselves. It is concluded that aromatase is under multifactorial regulation in human adipose stromal cells. The activity is induced by glucocorticoids and by agents that stimulate cAMP-dependent protein kinase; the latter effect is potentiated by factors that stimulate protein kinase C, but is suppressed by growth factors such as EGF, FGF, and PDGF, whose actions are believed to be mediated by receptor-linked tyrosine kinase activity.

Adipose Tissue↗
PubMed1986

Development and steroidogenic activity of preantral follicles in the neonatal rat ovary.

The neonatal rat ovary is completely devoid of antral follicles until the twelfth day of age. During this period the ovary becomes steroidogenically active and responsive to gonadotrophins. The aim of this study was to correlate the onset of ovarian androgen and oestrogen production in vitro with the first appearance of distinct granulosa and theca cells. Although ovarian aromatase activity increased significantly on day 7 of age, ovarian oestrogen production was limited by low progesterone and testosterone production until day 12 of age. Increased aromatase activity on day 7 and androgen production on day 12 were coincident with the first appearance of granulosa and theca cells respectively. These functional and morphological changes were not associated with significant alterations in ovarian weight or concentrations of LH or FSH in serum.

Animals↗
PubMed1986

Handling hotheads.

Explore the source record for details and available documents.

Emergency Medical Services↗
PubMed1986

How to survive a hospital affiliation and/or merger.

Merger mania has taken firm hold of growth-oriented corporate America during the Reagan administration. Health care has not been exempt from this trend as the growth of proprietary chains such as AMI, HCA and Humana bear witness. As not-for-profit hospitals are forced to grapple with survival in an increasingly competitive and circumscribed business environment, they, too, will continue to pursue a course of greater affiliation. Amid this corporate reshuffling hospital materials managers need to know how they will fare in the changing marketplace.

Health Facilities↗
PubMed1986

Effect of a thromboxane synthetase inhibitor on eicosanoid synthesis and glomerular injury during acute unilateral glomerulonephritis in the rat.

Eicosanoid synthesis was studied in a model of in situ glomerulonephritis (gn) in the rat. Unilateral gn was induced by perfusion of left kidneys with 200 micrograms cationized human IgG followed by intravenous (i.v.) autologous anti-human IgG antiserum. Rats developed proteinuria in the first 24 hours and hypercellular gn with leukocyte infiltration in the left kidney. Synthesis of thromboxane B2 (TXB2), prostaglandin E2 (PGE2) and 6-ketoprostaglandin F 1 alpha(6-keto-PGF 1 alpha) was measured at 6, 12, 18 and 24 hours in isolated glomeruli by radioimmunoassay. In nephritic glomeruli there was a nine-fold rise in TXB2 at six hours (5.35 ng/mg glomerular protein) when compared to control (0.6 ng/mg). TXB2 was still elevated at 24 hours (2.7 +/- 1 ng/mg; control 0.7 +/- 0.2 ng/mg). There were no consistent changes in PGE2 or 6-keto-PGF 1 alpha. No changes were found in right kidneys of nephritic or control rats. Treatment of nephritic rats with a selective thromboxane synthetase inhibitor, dazmegrel (20 mg/kg 8 hourly intraperitoneally), suppressed glomerular TXB2 at 24 hours. TXB2 was also inhibited in right (non-nephritic) kidneys and serum. Dazmegrel did not inhibit proteinuria or glomerular hypercellularity. We conclude there is a major increase in glomerular TXB2 in this model which does not play an essential role in the development of proteinuria or cellular infiltration.

6-Ketoprostaglandin F1 alpha↗
PubMed1986

In vivo induction of Ia antigen in resident leukocytes in the normal rat renal glomerulus.

The normal rat glomerulus contains a mesangial population of mononuclear leukocytes, 35 to 70% of which express class II major histocompatibility complex antigen (equivalent to mouse Ia) Schreiner GF, Unanue ER: Lab Invest 51:515, 1984. Inducing factors for cellular expression of class II antigens in normal leukocytes are unknown. In this population, glomerular leukocyte origin and Ia expression have been studied in kidneys from bone marrow-irradiated Lewis rats transplanted into normal syngeneic recipients. Leukocytes (LC+) and Ia positive (Ia+) cells were enumerated in isolated glomeruli by immunofluorescence using monoclonal antibodies to rat common leukocyte antigen (MRC OX1) and rat Ia antigen (MRC OX3, and OX4). Irradiation to donors caused extreme depletion of glomerular LC+ cells. Twenty-four hours after renal transplantation into normal recipients the glomerular LC+ population was restored to 65% of normal, and by 3 days was complete. In contrast Ia+ cells which were also depleted by irradiation, remained low 24 hours post-transplantation and only reached normal levels after 4 days. Thus, Ia antigen expression is induced in a population of leukocytes derived from circulating mononuclear leukocytes after a residence time of 3 to 4 days in the glomerulus. While the glomerular factors responsible are unknown, these experiments provide the first evidence for in vivo basal Ia induction in a normal resident mononuclear leukocyte population.

Animals↗
PubMed1986

Scintigraphic features of primary sacral tumors.

The bone scan features of different types of sacral tumors in 16 patients were assessed. Four out of five patients with chordoma, the most common sacral tumor, demonstrated either reduced uptake or normal distribution of isotope at the site of this midline tumor. Plasmacytoma, which is not usually central, also caused reduced uptake on the bone scan. Ewing's sarcoma gave no consistent pattern. All other tumors caused increased uptake except for one unusual case of osteogenic sarcoma. Bone scintigraphy can be very useful in the assessment of sacral tumors. A midline sacral tumor that is cold on the bone scan is very likely to be a chordoma.

Adolescent↗