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Biomedical subjects

M Gutierrez

Publications and source records attributed to M Gutierrez.

At least 91 records · Page 5Linked to original sources
PubMed1991

Effects of steroidal and non-steroidal antiandrogens on the left atrium of the rat in vitro.

1. The effect of steroidal-cyproterone acetate (CPA, 10(-7)-10(-5) M), clormadinone acetate (CMA, 10(-7)-10(-5) M), medroxyprogesterone acetate (MPA, 10(-7)-10(-5) M) and spironolactone (SPI, 10(-7)10(-5)M) and non-steroidal-flutamide (F, 10(-7)-6 x 10(-5) M) and cimetidine (C, 10(-7)-10(-4)M) antiandrogens on contractile force of electrically stimulated left atria of the rat have been assayed. 2. CPA, CMA, MPA and F inhibit, in a dose-dependent way, the contractile force of left atria. SPI enhanced (P less than 0.01 at 10(-6) M), and cimetidine did not modify the contractile force. 3. F, but not CPA, CMA, MPA or SPI, inhibit the contractile force induced by CaCl2 (0.9-7.2 mM) on electrically stimulated left atria. 4. The inhibitory effect of CPA (10(-7)-10(-5) M) was significantly increased by atropine (10(-6) M) and diltiazen (10(-5) M), and significantly reduced by yohimbine (10(-7) M) and in reserpinized (2.5 mg/kg, 48 and 24 hr before experiments) rats. 5. Our results suggest that the negative inotropism of steroidal antiandrogens could be related to inhibition of noradrenaline release, presumably through an alpha 2 adrenergic effect. The negative inotropism produced by F is related to inhibition of calcium dependent process on left atria contraction.

Androgen Antagonists↗
PubMed1991

Measles-associated diarrhea in hospitalized children in Lima, Peru: pathogenic agents and impact on growth.

Because the causes of measles-associated diarrhea are not well known, 0- to 5-year-old children presenting to the hospital with measles-associated diarrhea (cases, n = 77) or acute diarrhea only (controls, n = 77) were compared. Growth and diarrheal morbidity were evaluated for 1 month after acute illness. Campylobacter jejuni was more frequently isolated from cases (31%) than controls (16%; P = .03). Rotavirus was absent in all cases versus 28% of controls (P less than .001). Incidence density for new episodes of diarrhea was significantly greater in cases (6.5 vs. 4.1; odds ratio, 1.6; confidence intervals, 1.09-2.34; P = .01), as was duration of episodes (3 vs. 2 days, P = .02). Both groups showed similar positive cumulative percentage weight gains throughout follow-up. These data support the theory of measles as a risk factor for developing diarrhea. The bacteriologic and virologic findings may reflect the immunologic response of the host to measles infection.

Acute Disease↗
PubMed1991

Localized epidermal necrolysis (erythema multiforme-like reaction) following intravenous injection of vinblastine.

We report a case of localized epidermal necrolysis that developed 24 hours after an intravenous injection of vinblastine. Clinically, the lesions consisted of erythematous macules, vesicles, and bullae with a linear arrangement over the injected vein. Histologically, the lesions showed features closely resembling erythema multiforme (epidermal necrolysis). We discuss the pathogenesis of this curious cutaneous drug reaction and review the literature concerning local cutaneous complications associated with intravenously administered chemotherapeutic agents.

Erythema Multiforme↗
PubMed1990

Effects of androgenizing dairy heifers with ear implants containing testosterone and estrogen on detection of estrus.

Lactating dairy cows in four lots were observed for sexual behavior for 6 mo. One freemartin heifer in each lot was implanted with testosterone propionate and estradiol benzoate to aid in detection of estrus. Blood samples were obtained from androgenized heifers every other week for determination of serum testosterone. The addition of an androgenized heifer to each lot increased the number of mounts and attempts to mount cows, both overall and within observation periods. Thus, the likelihood of detecting a cow in estrus was increased with the addition of the androgenized heifers. Greatest benefit was seen when one or two cows were simultaneously in estrus in each lot. Observational data and serum progesterone concentration of mounted cows indicated that androgenized heifers were selectively mounting open cows displaying estrus, whereas the remaining nonandrogenized cows were less selective with their mounting activity. Serum testosterone increased after heifers were implanted, but testosterone was not related to the proportion of sexual activity. Duration of sexual activity by the implanted heifers was approximately 90 d.

Animals↗
PubMed1989

A multicentre study to introduce naltrexone for opiate dependence in Spain.

A multicentre prospective study was performed in eight centres in Spain in order to assess the usefulness of naltrexone in the treatment of opiate dependents and abusers (113 dependents and 37 abusers) non-selected in terms of social class or professional skill. The fundamental criterion for evaluation of clinical outcome was the retention rate. At 6 months this parameter was 40%, i.e. higher than any previously reported for non-selected patients. The adverse effects were mild and did not lead to therapeutic failures. Non-pharmacological factors may have contributed to the good clinical results obtained.

Adult↗
PubMed1988

An increment in unilateral carotid blood flow produces cerebral aneurysms in rats.

To study the effect of haemodynamic stress on cerebral aneurysm development, three groups of adult Wistar rats were used: 1) One group with ligation of the right common carotid artery; 2) One with an end-to-side common carotid artery anastomosis and 3) Another group that was sham-operated. Blood flow through the left common carotid artery was measured with an electromagnetic flow transducer (0.85 mm in diameter) in anesthetized animals. Before the experimental intervention, the mean carotid blood flow was 2.8 +/- 0.14 ml/min. Following carotid ligation the blood flow in the patent carotid artery increased 25 +/- 5% after 7 +/- 0.3 days and 37 +/- 18% after 149 +/- 23 days; whereas following carotid anastomosis, carotid blood flow increased 102 +/- 16% after 9.6 +/- 2 days and 103 +/- 35% after 169 +/- 15 days. The sham operation did not significantly affect carotid blood flow. Control values for mean arterial pressure (102 +/- 3 mmHg) and blood gases (PaO2 = 106 +/- 3.4 mmHg, PaCO2 = 38 +/- 1.2 mmHg and pH = 7.32 +/- 0.02) were similar in the three groups of rats and did not change significantly over time after the experimental procedure. Necropsy was carried out 149 +/- 15 days after the experimental intervention. No cerebral aneurysms were found in the rats with carotid ligation or which had been sham-operated, however, three of the eight rats (p less than 0.05) with carotid anastomosis presented single aneurysms in the anterior cerebral-anterior communicating arterial complex.(ABSTRACT TRUNCATED AT 250 WORDS)

Anastomosis, Surgical↗
PubMed1988

A randomized trial comparing chlorambucil plus prednisone vs cyclophosphamide, melphalan, and prednisone in the treatment of chronic lymphocytic leukemia stages B and C.

Ninety-six previously untreated patients (67 males/29 females; mean age: 63 years; range: 46-84) with CLL in stage B (62 cases) or C (34 cases) were randomized to be treated with either chlorambucil (0.4 mg/kg orally days 5 and 6) plus prednisone (60 mg/m2 orally days 1 to 4) (CL + PDN) every 2 weeks or cyclophosphamide (160 mg/m2 orally days 1 to 4), melphalan (6 mg/m2 orally days 1 to 4), and prednisone (60 mg/m2 orally days 1 to 4) (CMP) every 3 weeks for 10 months. Forty-eight patients were treated with CLR + PDN, and the remaining 48 with CMP. The following types of response were considered: complete response (CR): total disappearance of symptoms and signs related to the disease. Partial response (PR): shift of the disease to a less advanced stage. Stable disease (SD) no change in the stage after treatment. Progressive disease (PD): progression of the disease to a more advanced stage. Thirty-six (75%) responses (27% CR) with CLR + PDN and 26 (54.5%, 12.5% CR) with CMP were observed (p = 0.054). Although more responses were achieved in stage B (69%, 24% CR) than in stage C (54%, 12% CR) this difference did not achieve statistical significance. Survival was statistically not different for those patients treated with LCR + PDN as compared to those receiving CMP.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1987

Alpha 2-adrenoceptor-mediated inhibition of platelet adenylate cyclase activity in heroin addicts in abstinence.

The inhibition of basal and forskolin-stimulated platelet adenylate cyclase activity by (-)adrenaline was studied in ten heroin addicts during spontaneous withdrawal. Both basal and forskolin-stimulated enzyme activities were increased during heroin withdrawal and the inhibitory effect induced by (-)adrenaline was potentiated with parallel shifts to the left of the concentration-effect curves. The number of binding sites for [3H](-)adrenaline in platelet membranes was also increased during withdrawal. Treatment with clonidine markedly attenuated the inhibitory effect induced by (-)adrenaline on platelet adenylate cyclase activity. The results indicate that the heroin withdrawal syndrome induces supersensitivity of the platelet alpha 2-adrenoceptor-adenylate cyclase system.

Adenylyl Cyclases↗
PubMed1987

Neuroepithelial cyst in the optic nerve. Case report.

A 34-year-old woman presented with progressive loss of vision in her left eye of 2 months' evolution. Computerized tomography showed a hypodense lesion in the suprasellar region. At surgery a cystic lesion was found inside the optic nerve. Histological study proved it to be a neuroepithelial cyst. The pathogenesis of a neuroepithelial cyst in such an exceptional site is discussed.

Adult↗
PubMed1986

Heroin increases the density and sensitivity of platelet alpha 2-adrenoceptors in human addicts.

The density of platelet alpha 2-adrenoceptors, quantified by means of the binding of [3H]clonidine, and the aggregation response induced by adrenaline, was investigated in ten heroin addicts. The number of binding sites for [3H]clonidine was significantly increased during heroin abuse. Concomitantly, there was a potentiation of the adrenaline-induced platelet aggregation, which suggested that continuous heroin use (opiate dependence) is associated with supersensitive platelet alpha 2-adrenoceptors in human addicts. Spontaneous heroin withdrawal further increased in the same addicts the density of platelet alpha 2-adrenoceptors. These results suggest that platelet alpha 2-adrenoceptors may be used as a model to study receptor mechanisms of opiate dependence and withdrawal in humans.

Adult↗
PubMed1986

Annuloaortic ectasia and adult polycystic kidney. A frequent association.

The association of annuloaortic ectasia and polycystic kidney in 18 consecutive patients who had intravenous pyelograms was 22 percent (4/18). Due to this high association rate, some type of work-up to study the kidney anatomy should be performed in every case of annuloaortic ectasia. For the same reasons, patients with adult polycystic kidney should have a careful cardiovascular evaluation.

Aorta, Thoracic↗
PubMed1985

Platelet alpha 2-adrenoceptors in heroin addicts during withdrawal and after treatment with clonidine.

The density of platelet alpha 2-adrenoceptors, quantitated by means of the binding of [3H]clonidine and [3H]yohimbine, and the aggregation response induced by adrenaline were investigated in thirty-two heroin addicts during spontaneous withdrawal. The number of binding sites for [3H]clonidine, but not for [3H]yohimbine, was significantly increased during withdrawal and the increase followed a time course related to the severity of the abstinence syndrome. There was a positive and significant correlation between the severity of withdrawal and the density of platelet alpha 2-adrenoceptors. Concomitantly, the adrenaline-induced platelet aggregation was potentiated. Treatment with clonidine led to significant decreases in receptor densities as well as in functional responses. These results suggest that only alpha 2-adrenoceptors in the agonist state (i.e. number of binding sites for [3H]clonidine) are modulated during the development of the heroin withdrawal syndrome.

Adult↗
PubMed1985

Infantile calcified cerebral aneurysm.

A case of a calcified aneurysm of the posterior cerebral artery is reported. Frequency, aetiology, pathology, diagnosis and treatment of these aneurysms are discussed.

Calcinosis↗
PubMed1983

Cardiac rehabilitation after acute myocardial infarction. 9-year controlled follow-up study.

Since the effect of cardiac rehabilitation (CR) on morbidity and mortality due to myocardial infarction on a long-term basis appears controversial, a controlled follow-up survey was conducted from 1973 to 1981 in 193 patients suffering a first acute myocardial infarction (AMI). The admission criteria included absence of contraindications to CR during the acute phase of AMI. Patients were divided into two matched groups: 93 patients followed a CR program, exercising 30 min three times a week (means 42; range 6-108 months) and the remaining 100 patients served as controls. Age, sex, location and extension of the myocardial damage, frequency of coronary risk factors and complications during the acute phase were comparable. At 9 years, there were 24 cardiac deaths (15 AMI, 7 sudden deaths and 2 heart failures) among the controls and 13 deaths in the CR group (7 AMI, 4 sudden deaths, 2 heart failures), mortality rates being 5.2 and 2.9% per year (p less than 0.1 greater than 0.05; NS), respectively. There were 23 recurrent AMI in the control versus 16 in the CR patients, the corresponding rates being 4.9 and 3.6% per year, respectively (NS). Nor were any differences observed in the incidence of myocardial ischemia, severe arrhythmias or cerebrovascular strokes between both groups, but the appearance of angina was significantly lower in the CR group compared with the controls (5.1 and 10.2% per year, respectively, p less than 0.005). It is concluded that CR on a long-term basis seems to improve the mortality rate of AMI and to reduce the frequency of anginal pain.

Adult↗
PubMed1977

Purification and properties of the NAD(P)H:nitrate reductase of the yeast Rhodotorula glutinis.

The assimilatory nitrate reductase from the yeast Rhodotorula glutinus has been purified 740-fold, its different catalytic activities have been characterized and some inhibitors studied. The purified enzyme (150 units per mg protein) contains a cytochrome of the b-557 type. An S20,w of 7.9 S was found by the use of sucrose density gradient centrifugation, and a Stokes radius of 7.05 nm was determined by gel filtration. From these values, a molecular weight of 230 000 was estimated for the native enzyme. The purified preparation consisted of two electrophoretically distinguishable proteins, both of which exhibited nitrate reductase activity. The species with the higher electrophoretic mobility which represented the great majority of the total nitrate reductase gave a positive stain for heme and was shown to be composed of subunits with a molecular weight of about 118 000. Thus the molecule contains two subunits of the same size.

Azides↗