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Biomedical subjects

F Martinez

Publications and source records attributed to F Martinez.

At least 145 records · Page 8Linked to original sources
PubMed1992

Does endoscopy improve prediction of the prognosis in upper gastrointestinal bleeding?

To evaluate the prognostic value of the endoscopic examination, we included 189 consecutive patients with upper gastrointestinal bleeding, in a prospective study. Rebleeding was more frequent in patients with endoscopic stigmata of hemorrhage. The prognostic prediction given by the physician was slightly, but not significantly, improved after the result of the endoscopy was available. However, when the clinical data were evaluated by computer, using the Bayes' theorem, the endoscopic findings provided no additional prognostic value. We conclude that the endoscopic findings have intrinsic prognostic value, but add little to clinical data obtained on admission.

Adolescent↗
PubMed1992

Anaphylactic shock by rupture of hydatid hepatic cyst. Follow-up by specific IgE serum antibodies.

Total and specific serum IgE antibodies were estimated in a 68-year-old woman with anaphylactic shock due to spontaneous rupture of hydatid cyst of the liver. After she had recovered, an abdominal ultrasonography showed a cyst, 10 x 15 cm, in the right hepatic lobe. The cyst was surgically removed. Antihydatid IgE in the acute phase and periodically after surgical intervention, determined by Phadezym RAST, Pharmacia, and Pharmacia CAP system (a new solid-phase immunoassay, fully automated, for the titration of specific IgE with greater sensitivity in the detection of low IgE antibody levels), showed decreasing antihydatid IgE antibodies on day 10 after surgical intervention and may thus serve to monitor the evolution of hydatid disease.

Acute Disease↗
PubMed1991

Cocaine immunotoxicity: abnormal cytokine production in Hispanic drug users.

Peripheral blood lymphocytes from 47 Hispanic poly-drug users with a history of cocaine abuse were analyzed for in vitro production of interleukin-1 (IL-1), interleukin-2 (IL-2), gamma-interferon (IFN) and plasma levels of soluble IL-2 receptor (SIL-2R). Cocaine use was confirmed and quantified by analysis of hair and urine samples, and subjects were grouped into 3 based on the extent of cocaine metabolites detected. No significant differences in IL-1 and IFN production were seen between the 3 groups. However, subjects with higher levels of cocaine in hair also showed higher levels of IL-2. In addition, a positive correlation was seen between cocaine concentrations and IL-2 levels. A corresponding negative correlation was seen between cocaine levels and levels of plasma SIL-2R. These findings suggest modulation of the IL-2 network by cocaine in poly-drug users.

Adolescent↗
PubMed1991

Renal vasoconstriction after low and high osmolar contrast agents in ischemic and non ischemic canine kidney.

We have assessed the effect of contrast media on renal blood flow before and after inducing renal ischemia. Diatrizoate, iopamidol and ioxaglate were injected within 15 seconds at 20 min intervals, at the dose of 1 ml/kg during a control period and 15 min after applying an aortic clamp to reduce the renal perfusion pressure to 70 mmHg. During the control period iopamidol, ioxaglate (17 +/- 13%) and diatrizoate (16 +/- 2%) induced a comparable decrease in renal blood flow (RBF). During the ischemic period the effects of diatrizoate on renal hemodynamic were dramatically enhanced. Ioxaglate andiopamidol induced a 20 +/- 12 and a 32 +/- 9% decrease in RBF at 1 minute, respectively. Iopamidol induced an increase in renal vascular resistance (RVR) from 0.8 +/- 0.08 to 1.46 +/- 0.26 mmHg min/ml (p less than 0.05). Ioxaglate induced an increase in RVR from 0.8 +/- 0.09 to 1.36 +/- 0.38 (p less than 0.05). Diatrizoate induced a 77 +/- 10% decrease in RBF and a maximum increase in RVR at 1 minute from 0.9 +/- 0.09 to 26 +/- 12 mmHg min/ml. There was still a 36 +/- 14% and a 23 +/- 13% decrease in RBF 10 and 20 min after diatrizoate administration. These changes were significantly higher than those observed with all contrast media during the control period and low osmolar contrast media during the ischemic period. We have thus shown that ischemia potentiates the renal vascular effect of contrast media.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Kidney Injury↗
PubMed1990

Hair analysis.

Explore the source record for details and available documents.

Animals↗
PubMed1990

Lipid-rich metastatic balloon-cell melanoma: diagnosis by a multimodal approach to aspiration biopsy cytology.

Fine needle aspirates from one of multiple liver nodules revealed a large number of discohesive malignant cells with abundant vacuolated cytoplasm. The patient had had left eye enucleation the year before, for a melanoma with focal areas of clear cell change. Pap stained preparations from the liver FNA displayed well the nuclear features of balloon cell melanoma, including anisonucleosis, prominent nucleoli and intranuclear inclusions. Diff-Quik stain demonstrated best the cytoplasmic features such as distinct cell margins and finely dispersed and sharply delineated clear vacuoles. No pigmentation was noted but melanoma was suspected after the history prompted comparison with the enucleated specimen resected a year previously. A multimodal battery of ancillary methods including electron microscopy (EM) and immunocytochemistry (ICC) allowed the confirmation of balloon-cell melanoma, a rare variant not previously described in the eye. By EM, abundant lipids were identified along with melanin-containing structures resembling melanosomes. S-100 positivity along with negativity for epithelial, lymphohistiocyte and germ cell markers was compatible with melanoma. These findings are consistent with the view that cytologic detection of poorly cohesive, hypervacuolated cells does not exclude the possibility of melanoma. This rare example of a lipid-containing melanoma stresses the value of obtaining good clinical history, comparing FNAs to any pre-existing material and utilizing a multimodal approach to cytologic diagnosis in select cases.

Aged↗
PubMed1990

Beta-adrenoceptor blockade potentiates exercise-induced release of atrial natriuretic peptide.

The effect of a non selective and a cardio-selective beta-blocker on basal and exercise-stimulated plasma atrial natriuretic peptide concentrations in healthy volunteers has been studied. Nine healthy volunteers received single oral doses of 5 mg tertatolol, 100 mg atenolol or placebo, at one week intervals, in a double blind cross over trial. At rest plasma atrial natriuretic peptide, aldosterone, antidiuretic hormone and cyclic GMP concentrations and plasma renin activity were not modified by the treatments. During exercise plasma atrial natriuretic peptide concentrations were significantly increased by each treatment, the increment being significantly greater on beta-blockers than on placebo. The rise in atrial natriuretic peptide was 72% after placebo (from 24 to 42 pg/ml), 184% after atenolol (from 30 to 86 pg/ml), and 183% after tertatolol (from 34 to 95 pg/ml), respectively. Thus, the study has shown that in healthy subjects the plasma natriuretic peptide concentration is increased by exercise and that the increase is considerably and equally potentiated by selective and non selective beta-adrenoceptor blockade. The effect may be mainly due to a reduction in ventricular contractility with an increase in atrial pressure. The beta-blockers did not influence the resting plasma atrial natriuretic peptide levels, which suggests that in healthy subjects basal atrial natriuretic peptide secretion is not controlled via beta-receptors.

Adrenergic beta-Antagonists↗
PubMed1990

Atrial natriuretic factor in patients with acromegaly.

In acromegaly the plasma volume is chronically elevated and it returns to normal when the disease is successfully treated. To define the role of ANF in such a chronic disorder of extracellular fluid volume homeostasis the plasma level was assayed in 37 acromegalic patients with active or inactive (successfully treated) disease. Five patients were studied before and after therapy. The effects of acute change in sodium-fluid status on plasma ANF levels was examined in 7 active and 4 inactive acromegalic patients and in 7 healthy subjects. As compared to 14 patients with inactive acromegaly, 23 patients with active acromegaly had an expanded plasma volume (n = 12; 50.1 vs 37.6 ml.kg-1 BW) and an increased blood concentration of growth hormone (n = 23; 22.5 vs 2.1 ng.ml-1). Plasma ANF concentrations in active and inactive acromegalic patients (33.2 and 26.6 pg.ml-1, respectively) did not differ significantly from one another or from the level in the controls (26.9 pg.ml-1). In those patients there was no correlation between plasma volume and ANF level. Infusion of 21 isotonic saline in 2 h led to a similar, significant increase in ANF levels in active (from 26.2 to 72.4 pg.ml-1) and in inactive acromegalic patients (from 33.6 to 96.7 pg.ml-1) as well as in healthy subjects (from 21 to 70.6 pg.ml-1). Successful treatment reduced the plasma volume (from 49.2 to 35.8 ml.kg-1 BW) and growth hormone level (from 10.1 to 2.6 pg.ml-1), while the ANF level remained unchanged (from 33.8 to 35.5 pg.ml-1).(ABSTRACT TRUNCATED AT 250 WORDS)

Acromegaly↗
PubMed1990

Effects of cocaine and morphine on IgG production by human peripheral blood lymphocytes in vitro.

Elevated serum levels of IgG are amongst the immunological abnormalities exhibited by intravenous drug addicts. We therefore addressed the hypothesis that cocaine and morphine (the major metabolite of heroin) exert a direct effect on human B cell function in vitro. Human peripheral blood mononuclear cells from normal individuals were incubated for 7 days with the T cell-dependent B cell activator pokeweed mitogen (PWM) and serial dilutions of either cocaine or morphine. At the end of this time total IgG was measured by use of a sandwich ELISA incorporating a biotin-labelled affinity-purified anti-IgG and streptavidin peroxidase. At concentrations relevant to those found in plasma, morphine and cocaine did not affect PWM-stimulated IgG synthesis in vitro. We suggest that these drugs of abuse do not directly influence human B cells, but in vivo exert immune modulatory effects via indirect mechanisms.

Acquired Immunodeficiency Syndrome↗
PubMed1990

A comparison of the effects of chlorpromazine and more selective histamine and 5-hydroxytryptamine antagonists on human IgG synthesis in vitro.

We have shown previously that chlorpromazine, a drug associated with immunological abnormalities in vivo, significantly potentiates pokeweed mitogen (PWM)-stimulated IgG synthesis by human peripheral blood mononuclear cells (PBMC) in culture. Chlorpromazine is a pharmacological antagonist of histamine and 5-hydroxytryptamine (5-HT) and thus may exert its immune-enhancing effects by competing with these amines for their respective receptors, which are known to be present on lymphocytes. In this report we show that histamine and 5-HT are present at micromolar concentrations in PBMC cultures. To examine the role of histamine and 5-HT in chlorpromazine-induced enhancement of IgG synthesis we incubated PWM-treated cells with a range of selective histamine and 5-HT antagonists, and with the amines added to cultures either alone or in combination with chlorpromazine. The H1 antagonists mepyramine and promethazine and the H2 antagonist cimetidine had no significant effect on IgG synthesis. The combined 5-HT1/5-HT2 antagonists methysergide and methiothepin also failed to modulate synthesis. Neither histamine nor 5-HT at concentrations up to 100 microM modulated IgG synthesis, nor did they abrogate the enhancement of IgG synthesis induced by chlorpromazine. We conclude that the modulation of IgG synthesis in vitro by chlorpromazine cannot be attributed to an interaction of this drug with lymphocyte receptors for histamine and 5-HT. Other possibilities for the mechanism of action of this drug on immune function are discussed.

Cells, Cultured↗
PubMed1990

Relaxin in sera during the luteal phase of in-vitro fertilization cycles.

To identify the time when relaxin can first be detected in peripheral sera after in-vitro fertilization (IVF) and embryo transfer, blood samples were collected from 20 women up to 14 days after oocyte retrieval. Sixteen women did not become pregnant and in eight of them relaxin (but not beta-human chorionic gonadotrophin, beta-hCG) was measurable for the first time at days 6 to 12. Concentrations of other hormones measured were also different in these eight women compared with the remaining eight non-pregnant women; their serum concentrations of 17 alpha-OH progesterone, progesterone and oestradiol were higher but concentrations of luteinizing hormone and follicle-stimulating hormone were lower. Three women became pregnant; relaxin and beta-hCG were first detected on the same day (10 to 12). The remaining woman had increased beta-hCG levels but did not develop a clinical pregnancy. Measurement of serum relaxin during IVF cycles may allow assessment of corpora luteal function before its identification by levels of steroid hormones.

Chorionic Gonadotropin↗
PubMed1990

Transport of urate and p-aminohippurate in rabbit renal brush-border membranes.

The mechanisms involved in urate and p-aminohippurate (PAH) transport in the rabbit renal brush-border membrane were investigated through study of membrane vesicles. Transport of [14C]urate and [3H]PAH was measured by a rapid filtration method. As previously reported by others, no OH(-)-PAH exchanger could be demonstrated by imposing an outwardly directed OH- gradient (pHin 7.4, pHout 6). In contrast, an OH(-)-lactate exchanger (or H(+)-lactate cotransport) was demonstrated. In the presence of valinomycin and an inwardly directed K+ gradient, both [14C]urate and [3H]PAH vesicle uptake were stimulated, demonstrating a potential-driven transport of these two anions. Probenecid, PAH, or cold urate decreased potential-driven urate uptake, suggesting that this transport was facilitated by a specific transport mechanism. The potential-driven urate transport described here may play a role in the second step of urate secretion in rabbits, because rate (or PAH) is transported across the brush-border membrane from the negative interior of the cell to the more positive omen.

Aminohippuric Acids↗