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Biomedical subjects

R Molina

Publications and source records attributed to R Molina.

At least 145 records · Page 8Linked to original sources
PubMed1991

Effects of tyramine on the human uterine artery in vitro.

1. We have studied the effects of tyramine on the human uterine artery (HUA) in order to assess its site of action. 2. Tyramine (5 x 10(-5) to 10(-3) M) contracts the isolated human uterine artery. Tachyphylaxis appeared when concentration-response curves were repeated and the contraction was diminished by prazosin (10(-8), 10(-7) and 10(-6) M). The maximal contraction induced by tyramine (10(-3) M) was 25% of the maximal response to noradrenaline (10(-5) M). 3. After 2 hr of tyramine perfusion a decrease of the contractile response to KCl, 30 and 60 mM (15.0 and 12.9%) and noradrenaline 10(-6) M (83.2%) is shown. 4. However, when tyramine was previously added for 3 min to the bath, the response to KCl increased while the response to noradrenaline was lower. 5. A possible postsynaptic antagonistic effect for tyramine in the HUA is suggested in addition to its usual presynaptic effect.

Animals↗
PubMed1991

Role of tumor necrosis factor in macrophage leishmanicidal activity in vitro and resistance to cutaneous leishmaniasis in vivo.

Recombinant human tumor necrosis factor (TNF) and purified murine TNF were both able to activate macrophages to destroy intracellular Leishmania major in vitro. In addition, parasitizing macrophages with L. major markedly increased the ability of the cells to produce TNF. Finally, when mice were vaccinated with an avirulent form of L. major, the animals produced large amounts of TNF but no gamma interferon in response to infection with virulent L. major. Treating these mice with a neutralizing anti-TNF antibody led to partial but not complete inhibition of the resistant state, which suggests that factors other than TNF and gamma interferon contribute to resistance to L. major.

Animals↗
PubMed1991

Tumor markers in chronic renal failure and hemodialysis patients.

Serum levels and the incidence of elevated levels of several tumor markers were measured in 30 patients with chronic renal failure (CRF) of different degrees, as well as in 36 hemodialyzed (HD) patients without clinical evidence of neoplasia. The tumor markers evaluated were carcinoembryonic antigen (CEA), CA 125, CA 15.3, CA 19.9, CA 50, alpha-fetoprotein, neuron-specific enolase (NSE), squamous cell carcinoma antigen (SCC), prostatic acid phosphatase and prostatic-specific antigen. Serum levels of CEA were above the cutoff limit in 33% of patients with CRF and 47% of HD patients, CA 50 was higher than normal values in 37 and 44% of patients, respectively. SCC was elevated in 43 and 72% of patients, respectively. Serum levels of CA 125 were elevated in 18% of patients with CRF and NSE in 36% of HD patients. In CRF several tumor markers (CEA, SCC, CA 50 and NSE) show a high false positive rate and may be unreliable for monitoring malignancies in uremic patients, while the other markers evaluated appear to maintain their specificity in this situation.

Adult↗
PubMed1991

Serum phosphohexose isomerase activities in patients with colorectal cancer.

Pretreatment levels of phosphohexose isomerase (PHI) were above the cutoff limit of 107 IU/l in 41% of patients with benign intestinal diseases and in 46% of patients with colorectal cancer. Sensitivity of PHI was related to the presence of distant metastasis and the location of the primary tumor. Patients with rectal tumors presented a lower sensitivity than patients with colonic tumors. Pretreatment levels of PHI had prognostic value and patients with elevated levels of this enzyme showed a shorter disease-free interval in comparison with those patients with normal PHI activities. However, the prognostic significance of PHI was not independent of Dukes' classification. The present study indicates that PHI is not useful in the follow-up of patients with colorectal cancer after curative surgery because of its low sensitivity in the diagnosis of recurrences (47%) and its low specificity in patients without evidence of disease (76%).

Biomarkers, Tumor↗
PubMed1991

[Human immunodeficiency virus infection in hemophiliacs: prevalence and current clinical situation].

The prevalence of HIV-antibody was studied in a cohort of 156 haemophiliacs controlled since before 1986. Ninety four patients (60%) were HIV-seropositive, and all of them had been previously treated with non-heated factor concentrates. Seroprevalence was 50% by 1983. Evidence for previous negative results was only available in 19 seropositive patients and all of them seroconverted before 1985. For the 148 patients exposed to non-heat treated factor concentrates, severe haemophiliacs and those with factor consumption greater than 100 x 10(3) had the maximal rate of seropositivity (81% and 75% respectively, p less than 0.005). Fifteen patients developed AIDS (10% of the HIV-positive), 12 of which have died. HIV infection has a high prevalence and it has become the most important cause of death in our haemophiliacs.

Adolescent↗
PubMed1991

Experimental infections of a Phlebotomus perniciosus colony using different procedures.

Flies of two colonies of Phlebotomus perniciosus established in Italy and Spain respectively, were infected with a Leishmania infantum isolate from Spain. Only P. perniciosus from Spain was completely found susceptible to the infection. Experimental infections of P. perniciosus from Spain with the same L. infantum isolate were carried out using RPMI or PBS as infective feeding mediums. The results demonstrate that using PBS it is possible to re-feed a great quantity of infected flies.

Animals↗
PubMed1991

[Doppler velocimetry of the arcuate arteries in adolescent pregnant women: predictive value in small for gestational age newborn infants].

A prospective study on 25 adolescent pregnant women was carried out. A single measurement of the systolic-diastolic ratio (S/D) was taken using continuous Doppler on arcuate arteries on both sides of the uterus. All measurements were taken after the 16th week of amenorrhea. The relationship between Doppler velocimetry and birthweight was established. Seven newborns were small for gestational age. The sensitivity of this method was 94.4% and specificity was 57.1%. Positive predictive value was 80.0% while negative predictive value was 85.0%. The importance of measuring both arcuate arteries and determining the site of placental insertion for proper interpretation of results is stressed.

Adolescent↗
PubMed1991

Cancer antigen 125 in serum and ascitic fluid of patients with liver diseases.

Serum concentrations of cancer antigen 125 (CA 125) were determined for 373 patients with various liver diseases: 57 with acute hepatitis, 57 with chronic hepatitis, 244 with liver cirrhosis (86 compensated and 158 decompensated), and 15 with primary liver cancer. The antigen was measured simultaneously in the serum and ascitic fluid of 46 of the patients with liver cirrhosis and sequentially in the serum and ascitic fluid of another 25 cirrhotics treated with paracentesis and (or) diuretics. Abnormal results for CA 125 were detected in sera from 4% of the patients with acute or chronic hepatitis, 60% of the patients with liver cirrhosis, and 67% of the patients with primary liver cancer. The main factor associated with abnormal serum concentrations of this antigen was the presence of ascites, with pathological CA 125 values in 94% of patients with ascites without jaundice (mean 566 +/- 528 arb. units/mL), compared with only 40% of patients with jaundice and without ascites (mean 40.1 +/- 28.5 arb. units/mL) (P less than 0.001). High concentrations of CA 125 were mainly associated with spontaneous bacterial peritonitis. The serum concentration of CA 125 decreased after treatment with paracentesis, but increased in patients treated with diuretics rather than paracentesis. The release of this antigen in liver cirrhosis appears to be independent of the liver disorder and, rather, results from peritoneal synthesis of this antigen.

Antigens, Tumor-Associated, Carbohydrate↗
PubMed1991

[Calcium dependence of the contractile response of the aorta in the rat, rabbit and guinea pig and in the human uterine artery].

The influence of extracellular Ca2+ on the contraction produced by noradrenaline (NA) (3 x 10(-6) M), KCl (60 mM) and BaCl2 (30 mM) on human uterine arteries (AUH) and aortic strips from rats, rabbits and guinea-pigs have been studied. The vessels were cut spirally and incubated in Krebs solution containing 2.5 mM Ca2+ (KN), 0 mM Ca2+ (K-0Ca) or 0 mM Ca2+ + 3 mM EDTA (K-EDTA). Both phases (fast and slow) of the response of aortic strips to NA and of the AUH to NA, KCl and BaCl2 were significantly smaller in solutions without Ca2+. Only in rabbit aortic strips the slow phase was significantly more reduced than the fast phase. Overall, the contractions of the rat aortic strips were most resistant to the absence of extracellular Ca2+. These results confirm the variability of the responses of blood vessels from different vascular beds and species to the removal of extracellular Ca2+.

Animals↗
PubMed1990

c-myc proto-oncogene expression in peripheral blood mononuclear cells from patients with primary Sjögren's syndrome.

We examined peripheral blood mononuclear cells (PBMC) from 16 patients with Sjögren's syndrome (SS) and 7 normal control subjects for the expression of the c-myc proto-oncogene. Patients with SS were found to have a significantly increased expression of c-myc messenger RNA compared with normal individuals. No abnormal forms of c-myc RNA were detected in the SS patients. DNA analysis did not show deletion, rearrangement, or amplification in the c-myc proto-oncogene. The methylation status of the c-myc gene in patients with SS was found to be comparable with that of the control subjects. Nuclear run-off assays showed increased transcription of the c-myc gene in some patients but normal transcription in others, suggesting that posttranscriptional mechanisms are also involved in the increased c-myc messenger RNA observed in these patients. Two patients with primary SS and B cell lymphomas were found to have normal c-myc expression in their PBMC. These results demonstrate the presence of activated PBMC in patients with primary SS and delineate some of the mechanisms that are involved at the molecular level. We speculate that increased c-myc expression may represent an early permissive event in the progression toward neoplasia in these patients.

Gene Amplification↗
PubMed1990

Pyridoxine therapy for palmar-plantar erythrodysesthesia associated with continuous 5-fluorouracil infusion.

The limiting toxicity of low dose continuous infusion 5-fluorouracil (200-300 mg/m2/day) is often palmar-plantar erythrodysesthesia (PPE). PPE developed in 16/25 patients (exact 95% confidence interval of 42%-82%) with metastatic colon cancer enrolled in a phase II trial. In this trial, 5-FU was given continuously at a dose of 200 mg/m2/day until toxicity or progressive disease forced discontinuation. The first signs of the syndrome developed at a median of 2 months following infusion initiation and, unless treatment was interrupted, became progressively worse. The incidence of moderate to severe PPE was 71% in the 14 previously untreated patients (exact 95% confidence intervals of 42-92%). Seventy-eight percent of the responders in the no prior treatment group developed PPE. The incidence of moderate to severe PPE was only 27% in the 11 previously treated patients (exact 95% confidence intervals of 6-61%). The higher incidence of PPE in the previously untreated patients probably resulted from a longer total infusion time (median = 7.3 months) than the previously treated (median = 4.5 months). The longer infusion time in turn was a result of the higher response rates (64 vs 18%) in the previously untreated versus treated groups. Five previously untreated patients who developed PPE received 50 or 150 mg of pyridoxine/day when moderate PPE changes were noted. Reversal of PPE without interruption of the 5-FU was seen in 4/5 patients. Four of these patients who received pyridoxine had responded to 5-FU treatment. No adverse affect of pyridoxine on clinical response was noted.(ABSTRACT TRUNCATED AT 250 WORDS)

Colonic Neoplasms↗
PubMed1990

Immunosuppressive properties of human follicular fluid.

Human preovulatory follicular fluids (FF) obtained in the course of stimulated cycles were analyzed for their possible immunologic functions. Different concentrations of FF (20%, 2%, 1%) inhibited the mitogenic response of normal human lymphocytes to concanavalin A (Con A). Lymphocytes were assessed for immunosuppressor activity after preincubation with FF. Lymphocyte mitogenic response to Con A was only suppressed by cells preincubated with FF at concentrations of 2% and 1% for at least 48 hours. No evidence of suppressor cell induction was seen following incubation of lymphocytes with 20% FF, nor was any significant relationship between FF immunosuppressor activity and the outcome of in vitro fertilization observed. We conclude that some factor(s) in FF may be capable of directly inhibiting lymphocyte response and inducing immunosuppressor cell activity in vitro.

Body Fluids↗
PubMed1990

Antenatal phenobarbital for the prevention of periventricular and intraventricular hemorrhage: a double-blind, randomized, placebo-controlled, multihospital trial.

To determine whether the neuroprotective properties of phenobarbital would alter the incidence and severity of intracranial hemorrhage in premature infants, we randomly assigned 110 women at less than 31 weeks of gestation to receive 10 mg/kg phenobarbital or placebo in a blinded fashion before delivery. Infants were examined postnatally with real-time ultrasonography for evidence of intracranial hemorrhage. Maternal demographics, pregnancy complications, antenatal management, and route of delivery did not differ between the phenobarbital group (n = 50) and the placebo group (n = 60). The total incidence of periventricular-intraventricular hemorrhage did not differ between the phenobarbital-treated (n = 54) and the placebo-treated (n = 67) infants. However, the frequency of grade 3 and grade 4 hemorrhages was 15% (10 infants) in the placebo group and 3.7% (2 infants) in the phenobarbital group (p less than 0.05). There were no differences in the severity of associated conditions in the babies to explain the difference in the incidence of severe hemorrhage between the study groups. We conclude that antenatal administration of phenobarbital appears to be effective in decreasing the severity of periventricular-intraventricular hemorrhage in infants delivered at less than 31 weeks of gestation.

Adult↗
PubMed1990

Inhibition of the growth of enteropathogenic bacilli by bacteriocins produced by micro-organisms from the sediment of wells.

The bacterial flora of the sediment of 20 wells of water for human consumption in the rural area of the VII Region in Chile was examined. Fourteen strains of bacteria, from different wells, produced bacteriocins which inhibited the growth of Salmonella typhi, Salm. typhimurium, Shigella sonnei and enterotoxigenic Escherichia coli. About 50% of these strains contained plasmids of different molecular weight and a large number of these codified for bacteriocins. The results suggest what is required to implement an efficient, simple and economical biological system for the purification or control of the number of enteropathogenic bacilli of well water in the rural area.

Bacteriocins↗