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Biomedical subjects

A Ruiz

Publications and source records attributed to A Ruiz.

At least 235 records · Page 13Linked to original sources
PubMed1993

Endocrine and morphological features of cystic ovarian condition in antiprogesterone RU486-treated rats.

Four-day cyclic Wistar rats (200 g body wt) were injected (sc) with the antiprogestagen RU486 (4 mg RU486/0.2 ml oil) on estrus, metestrus, diestrus and proestrus. Groups of rats (12-15) were decapitated on days 1 (day of expected ovulation), 5, 9, 13, 17 and 21 after the 4 days of RU486 treatment. Oil-injected rats decapitated on proestrus (day 0) and estrus (day 1) served as controls. In both controls and RU486-treated rats, the following parameters were noted: ovulation, vaginal smears and luteinizing hormone (LH), follicle-stimulating hormone (FSH), prolactin, testosterone and estradiol-17 beta serum concentrations. Also, pituitary, adrenal, uterus and ovary weight were recorded. RU486 induced ovulation blockade, persistent vaginal cornification, uterine ballooning and increased serum levels of LH, FSH, prolactin, testosterone and estradiol. Furthermore, the LH/FSH and testosterone/estradiol ratios in serum increased. Pituitary and ovary weights also increased. The enlarged ovaries showed follicular cysts undergoing atresia and/or different degrees of luteinization of granulosa cells resembling, in some cases, genuine corpus luteum containing the ovocyte. The small follicles showed extensive atresia and stimulated thecal cells. These effects are reversible and remain in a stationary state for about 9-13 days after RU486 treatment. While the endocrinological alterations found in rats treated with RU486 are similar to those exhibited in polycystic ovarian disease, the morphological alterations found in the ovaries seem to be more closely related to the multicystic ovarian condition.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

Direct RT-PCR amplification of mRNA supported on membranes.

We describe a simple and efficient technique that facilitates the amplification of specific mRNA for cloning and sequencing purposes. An mRNA bound to a small piece of membrane filter is used as a template to synthesize complementary DNA. The product of this reaction is then transferred to a new tube and amplified using a standard PCR protocol. By simple enzymatic treatment, this RNA membrane can be reused as many times as needed with no problems of low yield, mispriming or background. Multiple advantages and different applications can be gained with this procedure. We have been using this technique to characterize a 4.5-kb mRNA from human retinal pigment epithelial cells following identification by Northern blot. According to the size of the PCR amplification products, this mRNA band contains portions of the coding sequence for the Na+K(+)-ATPase beta 1 subunit.

Base Sequence↗
PubMed1993

Evaluation of penicillin acylase production by two strains of Bacillus megaterium.

Penicillin acylase is a key enzyme for the production of semisynthetic beta-lactam antibiotics. The intracellular enzyme from Escherichia coli has been thoroughly studied and characterized. The extracellular enzyme from Bacillus megaterium, despite its potential advantages, has received less attention in the recent scientific literature. A comparative study is presented for the production of penicillin acylase with two strains of Bacillus megaterium in batch fermentation in previously optimized complex and defined media. The enzyme produced by the selected strain has been recovered, partially purified and its kinetic behaviour determined.

Bacillus megaterium↗
PubMed1993

[Detection of Pneumocystis carinii in clinical samples by the polymerase chain reaction. Comparison with the methenamine silver technique].

BACKGROUND: A comparison of polymerase chain reaction (PCR) with methenamine silver stain was performed on clinical specimens for diagnosis of Pneumocystis carinii pneumonia in immunosuppressed patients. METHODS: 25 clinical samples (10 induced sputa, 12 transthoracic needle aspirations and 2 bronchoalveolar lavages) from 17 patients with AIDS and respiratory symptoms were studied. We performed DNA amplification by using 2 primers that amplify the mitochondrial large rDNA sequence of P. carinii. RESULTS: The sensitivity and specificity of the PCR technique were 92.8% and 100% respectively, with a positive predictive value of 100% and negative predictive value of 92.3%. The sensitivity of the silver stain were 65%, specificity 100%, positive predictive value 100% and negative predictive value 63%. CONCLUSION: The PCR technique is more sensitive than the methenamine silver stain for detecting Pneumocystis carinii in respiratory specimens from patients with pneumonia. Consequently it could be a very good alternative to classical methods in diagnosis of P. carinii infections.

AIDS-Related Opportunistic Infections↗
PubMed1993

[Evidence of a major gene in cleft lip/palate susceptibility by means of segregational analysis in the Chilean population].

The most generally accepted model for cleft lip/palate not associated to specific syndromes has been the one that postulates multifactorial inheritance with a threshold. Recent studies using complex analytical techniques have suggested the existence of a major gene with decreased penetrance in its etiology. Some authors have postulated that only a fraction of all cases of non-syndromic CL (P) would be explained by a single major gene. Other cases may be due to different genes, to environmental agents or to the interaction between them. The present study tests the monogenic inheritance model for CL (P) using segregation analysis in a sample of 211 extended pedigrees collected through CL (P) affected probands. The hypotheses of an autosomic recessive gene was analyzed in 151 sibships (size 2 or more) using "Apert's" method, "maximum likelihood method", "singles method" and "sib's, method" (single incomplete ascertainment). Results obtained do not support the hypotheses of autosomal recessive inheritance. Instead, the hypothesis of an autosomal dominant mode of inheritance with low penetrance is not rejected when analyzing the proportion of normal and affected progeny in certain types of matings in a subsample of 30 extended pedigrees with two or more affected individuals.

Chile↗
PubMed1993

[Epidemiologic and clinical characteristics and clinical course of the HIV positive patient infected by heterosexual transmission].

We reviewed the features of patients with human immunodeficiency virus (HIV) infection, whose only way of acquisition was heterosexual contacts, analyzing differences with others risk groups. Epidemiological features (age, gender, family situation, socioeconomic status and sexual behavior), clinical manifestations immunological status, and evolution of 40 patients with HIV infection through heterosexual contact are studied, and compared with others risk groups. All were attended in our center from 1985 to October 1991; 15 were in stage IV. Along the study period, the proportion of heterosexual patients has steadily increased to represent 40% on total number of acquired immunodeficiency syndrome (AIDS) cases diagnosed in 1991. This study allow to establish two groups of patients depending on the gender. All men had had occasional sexual contacts with prostitutes, most had no stable partner, they mainly were between their fourth and sixth decade of life, and they were stable partners of seropositive patients or prostitutes, they had an averaged age significantly lower than men, and they were diagnosed in earlier stages. Two groups with different features can be established among the patients infected through heterosexual contacts. Men are adults, and acquired HIV infection through contacts with prostitute; they are diagnosed in late phases of the disease. On the contrary, women are younger, with no homogeneous patterns of behavior and they are diagnosed in earlier stages. Complications throughout the evaluation were similar in the heterosexual and in the other groups.

Adult↗
PubMed1993

[Differentiated thyroid carcinoma in childhood: multicenter review of the club of pediatric oncology].

The club of paediatric oncology of the Sociedad Española de Cirugía Pediátria conducted a retrospective and multicentric study on differentiated thyroid carcinoma in children. Seventeen cases from four hospitals were reviewed. Initial surgery in all cases consisted of partial or total thyroidectomy, associated in 76% of cases by cervical node removal. In 6 patients (35%) tumoral mass relapsed and 13 cases (76%) hypothyroidism was observed as a post-surgical sequela (in one patient, furthermore dysphonia and hypoparathyroidism persisted). Total survival rate in the series is 100%; one patient is currently diagnosed of node relapsed and remaining patients are disease-free. A diagnostic protocol based on echography, gammagraphy and biopsy is proposed. Oncology surgery i.e. tumoral and healthy tissue resection with node removal in one operation is recommended. With this approach, although we tend to place the patient in hypothyroidism and therefore susceptible to substitutive therapy, the multiple relapses observed in the review would be avoided. Prolonged follow-up guarantees early diagnosis of possible tumoral recurrence.

Adolescent↗
PubMed1992

Morphological changes in long bone development in fetal akinesia deformation sequence: an experimental study in curarized rat fetuses.

In order to investigate the transverse growth of the long bones during intrauterine development in the fetal akinesia deformation sequence (FADS), we studied curarized rat fetuses. Curarization was performed by daily subcutaneous administration of D-Tubocurarine from day 17 of gestation until term. Experimental fetuses were compared with a sham-operated control group. The total area and perimeter, the absolute and relative amount of periosteum and bone trabeculae, the major and minor axes, and the elongation factor were measured from histological cross-sections of the femoral metaphysis and diaphysis using an IBAS 1 image analysis system. Curarized rat fetuses showed growth retardation, a short umbilical cord, and multiple articular contractures, a phenotype consistent with FADS. Alterations in femoral shape and transverse growth that affected the diaphysis were noted in these fetuses. These included a decrease of total cross-section area and reduction of the absolute and relative amounts of bone trabeculae with marked thinning of the periosteum. Femoral cross-sections was rounder than controls. These results evidenced an impairment of the membraneous (periosteal) ossification of long bones produced by immobilization and/or decrease of muscular strength, and support our previous clinical findings of bone hypoplasia and osteopenia in FADS.

Animals↗
PubMed1992

Long bone development in extrinsic fetal akinesia: an experimental study in rat fetuses subjected to oligohydramnios.

The transverse growth of long bones during intrauterine development was studied in rat fetuses subjected to experimental oligohydramnios in order to determine whether the skeletal changes, if any, in extrinsic fetal akinesia were similar to those observed in curarized rat fetuses with the fetal akinesia deformation sequence. Oligohydramnios was induced by daily extraction of amniotic fluid from day 17 of gestation until term. Experimental fetuses were compared with a sham-operated control group. The total area and perimeter, the absolute and relative amount of periosteum and bone trabeculae, the major and minor axes, and the elongation factor were measured in histological cross sections of the femoral metaphysis and diaphysis with an IBAS 1 image analysis system. Rat fetuses in the experimental group showed multiple articular contractures, redundant skin, and lung hypoplasia, a phenotype consistent with the oligohydramnios sequence. No alterations in femoral shape and transverse growth of the metaphysis and diaphysis were noted in these fetuses. These results suggest that the main mechanical factor related to fetal bone modeling is muscular strength, while motion would be mainly involved in fetal joint development.

Animals↗
PubMed1992

Phase I study of mitonafide in solid tumors.

Mitonafide was the first synthetized compound of a new series of 3-nitronaphthalimides with intercalative properties. A phase I study with a conventional escalation scheme was developed. The schedule of drug administration was a daily x 5 days by short (1 h) intravenous (i.v.) infusion, every 21 days. Thirty evaluable patients were treated at doses from 15.4 mg/m2/d x 5 days to 138.6 mg/m2/d x 5 days. The study was interrupted due to appearance of central nervous system toxicity in 5 patients treated at doses above 118 mg/m2 x 5 days. This toxicity consisted firstly of loss of memory in all patients. It was irreversible and progressed in 3 patients to disorientation and confusion, leading to dementia in one of them. This was considered to be dose-limiting toxicity, and since it appeared to be related to the administration schedule, no further studies with short i.v. infusions of mitonafide are recommended. A phase I study utilizing a more desirable administration schedule over longer periods of time is ongoing in other centers.

Adult↗
PubMed1992

The evolutionary history of Drosophila buzzatii. XXV. Random mating in nature.

Using allozymes as the genetic probe, data are presented which show that wild Drosophila buzzatii females and males engaged in copulation mate at random. Hence, putative inbreeding due to local mating of genetically related flies emerging from the patchy distributed substrates, was not detected. We conclude that individuals raised from a niche disperse and mate at random with other members of the population, so only one round of drift due to the colonization of suitable and ephemeral breeding sites is taking place.

Alleles↗
PubMed1992

Aromatase activity and estradiol in human breast cancer: its relationship to estradiol and epidermal growth factor receptors and to tumor-node-metastasis staging.

PURPOSE: The present report attempts to clarify whether there is a relationship between aromatase activity (ARAC) and estradiol (E2), hormonal receptors, E2 receptor (ER), and epidermal growth factor receptor (EGFR), as well as with tumor stage and histopathology in human breast cancers. MATERIALS AND METHODS: We studied 225 breast carcinomas, 67 of which were premenopausal and 158 postmenopausal. In each sample, ARAC, EGFR, ER, and E2 were quantified. ARAC was quantified by Thompson and Siiterii's method, EGFR was quantified with a two-point assay method using radioactive iodine (125I)-EGF as ligand, and ER was measured by the Scatchard method using 3H-E2. E2 was quantified by radioimmunoassay in the diethylether tumor extract. RESULTS: ARAC was found in 64% of the cancers studied. There is a strong direct association between ARAC and tumor size in postmenopausal patients (P = .001). In the postmenopausal group, the proportion of ARAC-positive (ARAC+) tumors is significantly higher among ER-positive (ER+) than ER-negative (ER-) ones (P less than .001). ER+ tumors also have significantly higher levels of E2 than do ER- ones (P less than .0001); similarly, ARAC+ tumors have significantly higher levels of E2 than do ARAC- ones (P less than .0001). There is a significant multiple linear correlation between the log of the levels of ARAC, ER, and EGFR and the log of tumor E2 (P less than .0001). The correlation coefficients obtained show that ARAC and ER have a positive effect on tumor E2. CONCLUSION: The results obtained suggest the importance of tumor ARAC in the tumoral levels of E2 and reinforce the possible biologic significance of tumor ARAC, especially in postmenopausal breast carcinoma patients.

Adult↗
PubMed1992

[Clinical aspects of depression in general medicine patients].

The prevalence and clinical characteristics of depression were studied in 110 randomly chosen patients attending a general medicine outpatient facility. Two psychiatrists evaluated depression according to DSM-III-R criteria and measured the intensity of depression using the Hamilton scale. 25 cases were diagnosed as Mood disorders and 8 as Adaptative disorders. Depression was minor in all cases. Anxiety and somatic complaints were the main symptoms. The influence of the classification system used, demographic and seasonal factors are discussed.

Adult↗
PubMed1992

[Cervical cystic hygroma].

Hygroma being a rare overgrowth the AA. of the paper consider interesting the report of a case sitting in the neck, diagnosed and treated at Arnau de Vilanova Hospital. Memento concerning this entity.

Child↗