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Biomedical subjects

F M Gonzalez

Publications and source records attributed to F M Gonzalez.

At least 19 recordsLinked to original sources
PubMed1995

Natural killer cell activity in patients with pernicious anemia.

Patients with pernicious anemia have an estimated risk of gastric adenocarcinoma that ranges from three- to fivefold greater than that of the general population. It has been reported that NK cells may be involved in immunosurveillance against tumor spread. The natural killer cell activity of peripheral blood mononuclear cells was analyzed in 22 patients with pernicious anemia and in 19 healthy controls. Levels of natural killer cell activity against K-562 target cells were similar in control subjects and patients, regardless of gastrin levels and time elapsed since diagnosis. According to quantitative flow cytometry analysis, similar percentages of phenotypically defined NK cells (CD16+) were found in peripheral blood mononuclear cells from patients and healthy controls. Our results show that in pernicious anemia patients, the percentage of NK cells present in peripheral blood mononuclear cells and their lytic activity are normal.

Aged↗
PubMed1994

Hypercoagulable states as an evolving risk for spontaneous venous and arterial thrombosis.

This study of 49 patients with spontaneous venous and arterial thrombosis identified 27 with hypercoagulable states: 13 had only venous thrombosis (VT), six had episodes of VT followed by arterial thrombosis (AT) and eight had AT only. All 27 patients were less than 42 years of age; 22 had specific natural anticoagulant or fibrinolytic deficiencies: antithrombin III (nine patients), protein C (eight patients), protein S (three patients), heparin cofactor II (two patients), tissue plasminogen activator release (one patient) and mixed antithrombin III and protein S (one patient). The remaining five patients had recurrent thrombotic events associated with resistance to heparin anticoagulation, but no established laboratory diagnosis. Clotting complications included recurrent VT, pulmonary embolism, multiple failed arterial procedures and lower extremity amputation. The remaining 22 patients (mean age of 53 years, range of 46 to 63 years), 12 with VT and ten with AT, did not have laboratory evidence of hypercoagulability and none had recurrent vascular occlusions. All these patients were successfully treated by conventional therapy without any additional thrombotic events during the follow-up period. Young adults with spontaneous thrombotic events should be screened for possible hypercoagulable states. Additionally, these young patients need further evaluation and treatment of cardiovascular risk factors. Those with premature atherosclerosis have an especially poor prognosis despite surgical intervention and anticoagulant therapy.

Adult↗
PubMed1993

Renal failure and hyperkalemia associated with ketorolac tromethamine.

Three patients who were treated with ketorolac tromethamine (Toradol), an injectable nonsteroidal anti-inflammatory drug for pain management, developed acute renal failure or hyperkalemia or both. These complications were reversible in two cases after discontinuing the drug. Clinical conditions preexisted in each patient that rendered them susceptible to the renal complications of nonsteroidal anti-inflammatory use. It is well known that caution should be observed while using nonsteroidal anti-inflammatory drugs in patients whose renal function may be preserved through prostaglandin-mediated vasodilatory effects. The same cautions apply to ketorolac. Since its major marketed use is as an analgesic and its potent effect on prostaglandin synthesis may not be well recognized, those cautions must be emphasized.

Acute Kidney Injury↗
PubMed1991

Sequential measurement of beta 2-microglobulin levels, p24 antigen levels, and antibody titers following transplantation of a human immunodeficiency virus-infected kidney allograft.

A renal allograft recipient developed symptoms suggestive of AIDS. Serological studies revealed that the donor was positive for human immunodeficiency virus (HIV). Retrospective testing of stored sequential serum samples showed that the recipient was negative for HIV pretransplant; anti-p24 and anti-p41 antibodies appeared 10 and 49 days posttransplant, respectively. The recipient's serum beta 2-microglobulin levels were elevated 14 days posttransplant, with normal renal function, 35 days before the detection of anti-p24 antibody. p24 Antigen was detected for the first time 21 days posttransplant. In addition to p24 antigen, elevated serum beta 2-microglobulins may be a useful marker for HIV infection prior to seroconversion.

Adult↗
PubMed1990

Assessment of intravenous fenoldopam mesylate in the management of severe systemic hypertension.

To evaluate the acute BP response to iv fenoldopam mesylate (FNP), 14 patients with severe hypertension (diastolic BP 120 to 170 mm Hg) were studied in an open-label trial. Initial infusion rate of FNP was 0.1 microgram/kg.min. Titration to diastolic BP goal (95 to 110 mm Hg) was followed by a constant infusion phase (greater than or equal to 6 h), a detitration phase (2 h), and a postinfusion phase. FNP reduced BP by 27/29 mm Hg (p less than .001) with no significant effect on heart rate. Maintenance of the BP effect was noted through the 6 h of constant rate infusion. Mild, transient vasodilating-associated adverse effects were noted with FNP. We conclude that FNP is an effective, well-tolerated iv antihypertensive agent for acute BP reduction in a severely hypertensive population.

2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-ben↗
PubMed1990

Muscarinic control of gallbladder dynamics. A study using 99Tcm-HIDA and cholinergic agonists and antagonists.

We studied 12 normal subjects who underwent four 99Tcm-HIDA examinations. Imaging was performed with 111 MBq at 1 image/min for 60 min, and was registered on a computer on a 64 x 64 word matrix. Normalized and background corrected time-activity curves on the gallbladder were obtained from which total and cumulative 10 min interval emptying was calculated. During the first examination (control), 10 min after the beginning of acquisition, 1 ml saline solution was injected subcutaneously. The second examination was performed injecting 5 mg bethanechol subcutaneously instead of saline solution. During the third and fourth examinations 10 mg pirenzepine and 0.15 mg/10 kg atropine were injected i.v. respectively, 5 min before bethanechol injection. Wilcoxon's test was used to compare the first and second studies and the latter with the third and fourth studies. The median value of gallbladder emptying at 60 min was 2% with saline solution injection and 27.5% with bethanechol. This difference was significant from minute 30 onwards. Atropine administration inhibited gallbladder emptying completely in all cases, with significant differences (P less than 0.01) in relation to bethanechol values following the first 30 min of the examination. Gallbladder emptying was observed in the study with pirenzepine, but was significantly inferior to the bethanechol values after the first 30 min.

Adult↗
PubMed1990

Intravenous fenoldopam versus sodium nitroprusside in patients with severe hypertension.

In an open-label study, we compared the efficacy and safety of intravenous infusion of fenoldopam mesylate with that of sodium nitroprusside in patients with severe hypertension or in hypertensive crisis. Both antihypertensive medications were infused at a maximal dose increment of 0.2 microgram/kg/min (fenoldopam) and 1 microgram/kg/min (nitroprusside), with a maximal infusion rate of 1.5 micrograms/kg/min fenoldopam mesylate or 8 micrograms/kg/min sodium nitroprusside. Once the desired reduction in diastolic blood pressure was achieved (less than 110 mm Hg if initial diastolic blood pressure was 120-149 mm Hg, or by at least 40 mm Hg if initial diastolic blood pressure was 150-190 mm Hg), the maximal infusion rate used was maintained for at least 1 hour, and then, the infusion was slowed gradually over 2 hours. After the infusion treatment, patients remained in the hospital for 2 days of follow-up. Both antihypertensive agents successfully controlled the blood pressure in all the patients by the end of the maintenance periods. Between the baseline and the end of the maintenance period, analysis of variance showed that the changes in the variables induced by fenoldopam mesylate did not differ significantly from those induced by sodium nitroprusside. The incidence of side effects listed were similar in both groups of patients. The detection of toxic levels of thiocyanate in two patients treated with nitroprusside, however, shows that fenoldopam might be preferable for the control of a hypertensive crisis or severe hypertension in patients with decreased renal function.

2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-ben↗
PubMed1989

99Tcm-MAG3 for quantitation of differential renal function.

We studied two different methods for the evaluation of differential renal function in a group of 100 patients with various kidney disorders whose effective renal plasma flow (ERPF) had been calculated previously by single 125I-orthoiodohippurate (OIH) injection and multiple blood sampling. Patients were divided into three groups according to their ERPF:ERPF is greater than or equal to 250 ml min-1; ERPF less than or equal to 100 ml min-1; and ERPF greater than 100 ml min-1 and less than 250 ml min-1. The two methods used to assess differential renal function were: first, relative 99Tcm-dimercaptosuccinic acid (DMSA) uptake calculated by normalized background and attenuation corrected cumulative counts in each kidney 24 h p.i.; and second, relative 99Tcm-mercaptoacetyl-triglycine (MAG3) uptake within 1 and 2 min p.i. calculated by normalized background and attenuation corrected counts on each renal area. The results obtained with each method correlated strongly with high significance (p less than 0.0001). In the right kidney, mean values obtained with 99Tcm-MAG3 tend to be higher than mean values obtained with 99Tcm-DMSA.

Adult↗
PubMed1988

Selective dopamine-1 agonist therapy in severe hypertension: effects of intravenous fenoldopam.

To determine the effects of dopamine-1 agonist therapy in severe hypertension, blood pressure, heart rate, catecholamines and left ventricular function were studied in 18 patients (10 with renal disease) with diastolic blood pressure greater than 120 mm Hg (range 124 to 160) after intravenous fenoldopam therapy. Constant infusions of fenoldopam were titrated upward every 10 to 20 min from an initial dose of 0.1 microgram/kg per min to a maximal dose of 0.9 microgram/kg per min. The therapeutic goal of a supine diastolic blood pressure of less than 110 mm Hg was achieved in every patient within 1 h at an average dose of 0.34 +/- 0.22 microgram/kg per min. Blood pressure decreased from 214/134 +/- 33/10 mm Hg at baseline to 170/96 +/- 29/7 mm Hg (p less than 0.0001) at 3 h, whereas heart rate increased from 77 +/- 23 to 88 +/- 21 beats/min (p less than 0.01). Plasma norepinephrine increased during the fenoldopam infusion; epinephrine and dopamine levels did not change. Two indexes of left ventricular function (end-systolic dimension and isovolumic relaxation time) improved during the fenoldopam infusion, but mitral flow velocities during ventricular filling were unchanged. Side effects of intravenous fenoldopam were mild, transient and associated with the marked vasodilatory properties of the drug. Thus, fenoldopam is safe and effective as a parenteral monotherapy in patients with severe essential and renovascular hypertension. Preliminary data suggest that blood pressure reduction with selective dopamine-1 agonist therapy is accompanied by improved left ventricular function.

Adult↗
PubMed1985

The cardiovascular and metabolic effects of mixtures of acetate and succinate: a potential improvement in dialysate solutions.

Various mixtures of acetate (AC) and succinate (SUCC) were studied for their metabolic and cardiovascular (CV) effects in 10 dogs. The CV effects seen with all mixtures were similar to those reported for SUCC alone with the only changes being increased cardiac output and decreased total peripheral resistance. The 50:50 per cent AC/SUCC offered the advantage of a rapid but less marked and more sustained HCO3 production. The pH changes in all mixtures followed HCO3 values. Since the addition of SUCC seems to reduce the untoward CV changes seen with AC alone, the ratio of AC/SUCC should be based on metabolic considerations. The present data suggest that a 50:50 per cent AC/SUCC mixture is optimal for metabolic and CV effects.

Acetates↗
PubMed1982

Comparison of effects of cyanide and acetylcholine on renal hemodynamics and sodium excretion.

The present study compared the effects of acetylcholine to cyanide under the same experimental conditions of renal clearance in anesthetized dogs. Since cyanide is one of the few drugs for which the mechanism of action is known (cytotoxic hypoxia), some insight may be gained into the renal effects of acetylcholine since both produce direct natriuresis and diuresis. Infusion of 0.2 microgram/kg/min of acetylcholine and 12.0 microgram/kg/min of sodium cyanide into the left renal artery resulted in similar effects, i.e., increased fractional excretion of sodium, potassium, calcium, and magnesium. These effects were immediate and ipsilateral. Both agents increased the renal plasma flow to the same extent. In addition, regression plots of the relation between changes in sodium excretion and changes in renal plasma flow were similar for both agents. The pattern of similar renal functional changes suggested that acetylcholine is not a mere renal vasodilator but that its action is also medicated through alterations on direct transport of ions.

Acetylcholine↗
PubMed1981

Congenital short urethra.

A surgical technique is described for the short urethra. The malformation is also described and differentiated from penile curvature of cutaneous origin. The urethroplasty involves division of the short urethra and the design of an island flap using penile skin formed into a tube over a sound. The reconstructed segment is placed between two divided segments of the original short urethra and restores its natural length. Complications and results are discussed. We have also encountered cases characterised by a slight curvature of the penis that was corrected after dissecting out the urethra over the full length of the penis. We call this "penile curvature due to anomalous disposition of the urethra", (Diaz Gomez, 1979) and it is remedied by moving the freed urethra 2-3 mm lower with the aid of sutures anchored to Buck's fascia.

Humans↗