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Biomedical subjects

E Gonzales

Publications and source records attributed to E Gonzales.

54 records · Page 3Linked to original sources

Coagulation cascade, fibrinolytic system, antithrombin III, protein C and protein S in patients maintained on continuous ambulatory peritoneal dialysis.

We studied the coagulation cascade, fibrinolytic system and naturally occurring anticoagulants in a group of 14 patients with end-stage renal disease maintained on continuous ambulatory peritoneal dialysis (CAPD). The results were compared with those obtained in a group of ten normal volunteers. Plasma procoagulant activities of factors XII, XI, IX, VIII, VII, X and II were significantly greater in the CAPD group as compared to the normal control group. Likewise plasma concentrations of total and free protein S were increased in the CAPD group. Although the mean value for plasma factor V activity in the CAPD group was higher than that found in the control group the difference did not attain statistical significance. In addition plasma fibrinogen concentration and factor VIII-related antigen level were significantly increased in CAPD patients. No significant difference was found between the CAPD patients and the control group with respect to plasma levels of protein C, antithrombin III, plasminogen or alpha 2-antiplasmin. In summary, the results demonstrate a tendency for increased levels of various coagulation factors and protein S in CAPD patients with no significant alterations in the levels of various fibrinolytic and endogenous anticoagulant agents, i.e. antithrombin III and protein C. The clinical significance and the mechanism responsible for the observed changes require further investigation.

Antithrombin III↗

Biochemical regulation of adenylate cyclase in murine melanoma clones with different metastatic properties.

The regulation of adenylate cyclase in murine melanoma tumor cell clones with different metastatic capacities has been studied in intact cells and isolated membrane preparations. Analysis of the responses of intact cells from a number of B16 melanoma clones revealed that treatment with melanocyte-stimulating hormone (MSH) or the diterpene, forskolin, produced significantly greater accumulation of intracellular cyclic adenosine 3',5' monophosphate (cAMP) in strongly metastatic clones than in weakly metastatic tumor cell clones. In contrast, in isolated membranes from the same panel of clones, the extent of activation by forskolin but not by MSH correlated with metastatic capacity. Sodium fluoride and 5'-guanyl-beta-gamma-imidodiphosphate [Gpp(NH)p] also stimulated adenylate cyclase in isolated membranes but the extent of activation did not correlate with the metastatic behavior of the donor cells. A combination of forskolin and Gpp(NH)p proved to be a sensitive prospective indicator for identifying differences in the metastatic capabilities of individual B16 melanoma clones. Adenylate cyclase in membrane preparations from strongly metastatic B16 clones displayed synergistic activation but stimulation of the enzyme from weakly metastatic clones was less than additive. To test the generality of these findings, similar investigations were performed on B16-BL6 melanoma cells, a highly invasive subline of the B16 melanoma, and the K1735, an ultraviolet-light-induced murine melanoma arising in a different mouse strain (C3H). Consistent with their high metastatic potential, clones derived from the B16-BL6 melanoma displayed elevated levels of hormonally-stimulated adenylate cyclase, thereby confirming, for this tumor system, a close association between hormonal responsiveness and metastatic capacity. In contrast, K1735 melanoma cell clones exhibited significant interclonal variation in adenylate cyclase activity and metastatic performance, but no consistent relationship between the two traits was detected. Differences in the regulation and/or the intrinsic catalytic capacity of adenylate cyclase may account, at least in part, for the variation in hormonal responsiveness observed among B16 clones with distinct metastatic properties and suggest that cAMP-dependent molecular processes may be required for the expression of B16 melanoma experimental metastatic potential.(ABSTRACT TRUNCATED AT 400 WORDS)

Adenylyl Cyclases↗

Dietary sodium deficiency potentiates the effect of prostaglandin E2 on in vitro renin release in the rat.

Using a renal cortical slice system from sodium loaded (SL) or sodium deficient (SD) rats, this study investigated whether the effect of prostaglandin E2 (PGE2) on renin release (RR) is mediated by tissue cyclic AMP content (TcAMPc) changes, and if it can be modified by dietary sodium manipulation. At 10(-5) M, PGE2 significantly stimulated RR and TcAMPc in both SL and SD groups of slices. PGE2 doses of 10(-9) M and 10(-7) M were ineffective, although RR, but not TcAMPc, was significantly greater in the SD group in response to 10(-7) M PGE2 than RR in the SL group. Addition of the phosphodiesterase inhibitor theophylline (10(-4) M) together with the same three PGE2 doses maintained the stimulatory effect of 10(-5)M PGE2 alone on RR and TcAMPc in both groups of slices, and reversed the effect of 10(-7) M PGE2 alone on RR and TcAMPc in the SD group of slices only. Added by itself, theophylline was ineffective. These data indicate that: PGE2 can stimulate RR by a direct effect on the juxtaglomerular cells; the RR responses to PGE2 and theophylline administration are enhanced in the SD state; and the possibility of cAMP mediation of the effect of PGE2 on RR is discussed.

Animals↗

Comparison of changes in tryptophan and serotonin in regions of the hamster and the rat brain over a twenty-four hour period.

Groups of male golden hamsters and Sprague-Dawley rats were sacrificed at 4-h intervals over a 24-h period. Tryptophan and serotonin (5-HT) were measured in the telencephalon and brain stem and tryptophan was measured in serum. Highly statistically significant changes in tryptophan and 5-HT content were observed over the period of the day. Generally the changes were more clearly defined and were significant to a higher statistical level in the hamster than in the rat. Statistically significant changes were also observed in serum tryptophan. In the hamster the daily changes in serum tryptophan were coincidental with similar changes in tryptophan and 5-HT in the brain stem and tryptophan in the telencephalon. On the other hand, the changes in 5-HT in the hamster telencephalon were not well correlated with changes in tryptophan and serum tryptophan.

Animals↗

Coronary Artery Risk Detection in Appalachian Communities (CARDIAC): preliminary findings.

West Virginia's mortality and morbidity from cardiovascular disease (CVD) is among the highest in the developed world. Appalachia, and West Virginia in particular, could reduce the high prevalence of premature coronary heart disease (CHD) by addressing modifiable independent risk factors such as poor nutrition, sedentary lifestyle, and tobacco use. School-based health promotion programs have been shown to be an effective means of influencing student and parental health behavior. The pilot phase of the Coronary Artery Risk Detection in Appalachian Communities (CARDIAC) project substantiated an alarmingly high incidence of CVD risk factors among 347 fifth grade children from three rural counties, and was also an effective means of identifying parents at risk of developing CHD. Utilization of the innovative Rural Health Education Partnerships (WVRHEP), coupled with a health conscious public school system, offers a unique opportunity to establish the first statewide cardiovascular disease community intervention project in the nation.

Blood Pressure Determination↗

Cytokine levels during hemodialysis.

The authors measured plasma IL-1 (interleukin-1), IL-2, IL-2 receptor (IL-2R), IL-4, IL-6, tumor necrosis factor (TNF), and granulocyte macrophage colony stimulating factor (GMCSF) in 10 stable patients during hemodialysis (HD) using new or reused polyacrylonitrile (PAN) or cuprophan (CU) dialyzers. Five HD patients with wasting syndrome, and 16 normal controls, were included. Hemodialysis patients showed a marked elevation of IL-2R. No IL-4, IL-6, or GMCSF were detected in any group. Tumor necrosis factor and IL-2 in the HD group were comparable with control values. No difference was found in the TNF levels in HD patients with and without wasting syndrome. Cytokine levels were unaffected by either new or used PAN or CU dialyzers.

Cytokines↗