Biomedical subjects

J Castro

Publications and source records attributed to J Castro.

At least 91 records · Page 5Linked to original sources

PubMed1993

[Cerebral metastasis of melanoma: study of 48 patients].

BACKGROUND: Malignant melanoma is a frequent cause of cerebral metastases (CM). In the present study the characteristics of primitive melanomas of patients with CM, their forms of clinical presentation and treatment were analyzed. METHODS: A retrospective study of the patients with melanoma and CM diagnosed between 1982 and 1991 was carried out. RESULTS: Out of 786 patients with melanoma 48 were identified with CM. In 65% of the melanoma originated in cutaneous areas BANS (of bad prognosis). The median thickness of the tumor (Breslow's index) was of 3.6 mm. The median period of latency between diagnosis of the melanoma and the detection of CM was 22 months. Although recent hemorrhage of the CM was observed in the cranial computerized tomography in 20 of the 48 patients, only 7 presented clinical symptoms of ictus. In 23 patients the CM were the only evidence of metastases of the melanoma. The median survival was one month in the patients treated with only dexamethasone, 3.5 months in the chemotherapy group, 2.5 months for the group given radiotherapy and 6 months for those undergoing surgery. CONCLUSIONS: Most of the patients with cerebral metastasis had a primitive melanoma with criteria of bad prognosis. The presence of hemorrhage in computerized tomography did not always correlate with clinical symptoms of ictus. Surgical treatment must be considered in patient with sole cerebral metastasis without evidence of distant disease.

Adult↗

PubMed1993

What price mental health?

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Adolescent↗

PubMed1993

Paging Dr. Clinton.

Explore the source record for details and available documents.

Competitive Medical Plans↗

PubMed1993

Preparation of cell nuclei from fresh tissues for high-quality DNA flow cytometry.

An easy method for preparation of bare cell nuclei from fresh solid tissues for DNA flow cytometry is described. Pieces of up to 2 x 2 x 2 mm3 size from fresh tissues were fixed in formalin. After removal of formalin by washing with ethanol and rehydration with tap water, the tissue pieces were incubated with subtilisin Carlsberg (pronase, Sigma protease XXIV) and then stained directly with DAPI. Staining with ethidium bromide gave unsatisfactory results. Neither mechanical disaggregation nor centrifugation were used. The resulting cell nucleus suspensions had extremely low frequencies of debris particles and of clumped cell nuclei. A good yield, a minimized loss, and a good stainability of cell nuclei were obtained. The applicability of the method was exemplified by the analysis of biopsies from the colon-rectum in patients with ulcerative colitis and of biopsies from the bladder in patients with bladder cancer and compared to the standard method of this laboratory, which uses mechanical disaggregation, ethanol fixation, pepsin treatment, and staining with ethidium bromide. The formalin-subtilisin Carlsberg technique resulted in good agreement of ploidy measurements compared to the standard method, a higher number of evaluable histograms, an improved detectability of aneuploid cell populations, and an improved accuracy of the S- and G2-phase analysis, particularly in samples with low proliferation. The method also makes it possible to use long-term storage and to transport samples by post.

Animals↗

PubMed1993

Effects of lovastatin on hepatic fatty acid metabolism.

The in vitro and in vivo effects of lovastatin on fatty acid metabolism were studied in isolated rat hepatocytes. When added in vitro to cell incubations, lovastatin stimulated de novo fatty acid synthesis and acetyl-CoA carboxylase activity, whereas fatty acid synthase activity was unaffected. Lovastatin depressed palmitate, but not octanoate, oxidation. This may be attributed to the lovastatin-induced increase in intracellular malonyl-CoA levels, as no concomitant change of carnitine palmitoyltransferase I (CPT-I) specific activity was detected. Lovastatin had no effect on the synthesis and secretion of triacylglycerols and phospholipids in the form of very low density lipoproteins (VLDL). When rats were fed a diet supplemented with 0.1% (w/w) lovastatin for one week, both acetyl-CoA carboxylase activity and de novo fatty acid synthesis were reduced compared to pair-fed controls, whereas fatty acid synthase activity was unaffected. Palmitate oxidation was enhanced in the lovastatin-fed group. There was an increase in CPT-I activity but no change in intracellular concentration of malonyl-CoA. Lovastatin feeding had no significant effect either on the esterification of exogenous palmitic acid into both cellular and VLDL triacylglycerols and phospholipids or on hepatic lipid accumulation. The in vitro and in vivo effects of lovastatin were not significantly different between periportal and perivenous hepatocytes.(ABSTRACT TRUNCATED AT 250 WORDS)

Acetyl-CoA Carboxylase↗

PubMed1993

Sternal blood flow during mobilization of the internal thoracic arteries.

A laser Doppler tissue perfusion monitor was used to measure sternal blood flow before, during, and after mobilization of the internal thoracic arteries in 24 patients undergoing coronary artery bypass grafting. To minimize chest wall injury, a narrow pedicle was mobilized. Bilateral flow data were available from 15 of the 24 patients. Analysis of these 39 studies showed no significant reduction of sternal blood flow as a consequence of mobilization of the internal thoracic arteries except in 2 patients who were both diabetic and obese.

Aged↗

PubMed1993

Ultra-short topical treatment of pityriasis versicolor with 2.5% bifonazole cream.

The therapeutic efficacy of a preparation containing 2.5% bifonazole was investigated by comparing three different treatment modalities--A, B, and C. Group A used bifonazole only on Days 1, 2 and 3, and the Group C on Days 1, 3 and 5. Of the patients in Group A 56% had a negative mycological examination at the end of the study. The results obtained in Groups B and C were not significantly different: 92% of the patients had a negative mycological examination at the end of the study. Electron microscope (EM) studies showed morphological alterations such as loss of cytoplasmic organization with shrinkage and folding of the cell membranes after 1 week of treatment only in Groups B and C. We conclude that 2.5% bifonazole is a highly effective treatment for Pityrosporum ovale infection when applied using a 3-day schedule.

Administration, Topical↗

PubMed1993

Exploring the feasibility of assessing perceived parental rearing styles in Spanish children with the EMBU.

Most of the available data on the dimensional structure underlying the EMBU--an originally Swedish measure designed to assess one's recollections concerning one's parents' rearing behaviour--has been obtained with adults or adolescents. In the present study, using exploratory factor analysis, an attempt was made to determine the EMBU factorial structure in a Spanish sample of children aged 7-12 years (N = 205). Four factors explaining only 24% and 25% of the total variance in the ratings of the fathers and those of the mothers, respectively, and being invariant across parental sex, were interpreted: Emotional Warmth, Rejection, Control Attempts, and Favouring Subject. Results with respect to the internal consistency reliability of the corresponding scales were satisfactory, as were homogeneity figures pertaining to each set of theoretically-related items. Higher-order analyses of the first-order dimensions (mothers and fathers jointly) revealed three factors explaining 85% of the total variance. Control Attempts, Care (Rejection vs. Emotional Warmth), and Favouring Subject. The factorially-derived (first-order) scales were uncorrelated with sex of the recipient. All scales (except Rejection) correlated sizeably, negatively, with age (medium effect size) pointing, as outlined, to the need to take into account the relevant normative, design and research implications in further investigation. Some similarities and differences with findings yielded previously with adults and adolescents are briefly pinpointed.

Attitude↗

PubMed1993

[Comparative study of famotidine vs ranitidine in critically ill patients in mechanical ventilation].

Stress ulcers are frequent in critically ill patients. Gastric mucosa protection with antacids, H2 blockers or sucralphate decrease the incidence of stress ulcers and upper gastrointestinal bleeding but may have adverse effects. The present study compares the efficacy of continuous infusions of famotidine on gastric pH control and bleeding prevention in critically ill patients receiving mechanical ventilation. Fifty six patients (aged 55 +/- 22 years, 26 male) were randomly assigned to receive famotidine 40 mg/day (n = 27) or ranitidine 150 mg/day (n = 29) during 5 days. Gastric pH was measured every 6 hours and when it was below 5, aluminum hydroxide (30 ml every 2 hours) was administered to obtain values over 5. Patients receiving famotidine had higher mean gastric pH (6.3 +/- 0.2 and 93% of measurements over 5 vs 5.8 +/- 0.6 and 83% of measurements over 5 (p < 0.05), and required lower amounts of aluminum hydroxide (1.880 vs 2.770 ml). No patient had evidence of gastrointestinal bleeding and one had a mild psychomotor agitation. No other adverse reactions were observed. It is concluded that famotidine was more effective than ranitidine on gastric pH control in mechanically ventilated critically ill patients.

Acute Disease↗

PubMed1992

Somatostatin in the management of gastrointestinal fistulas. A multicenter trial.

To evaluate the effectiveness of treatment with total parenteral nutrition (TPN) alone (group A) or combined with continuous intravenous infusion of somatostatin (group B) in postoperative gastrointestinal fistulas, a multicenter, controlled and prospective randomized trial was designed. We present the results obtained after the evaluation of 40 cases (group A, n = 20; group B, n = 20). No significant differences among these treatment schedules were observed in the percentage of closure of fistulas (group A, 81.25%; group B, 85%), but patients treated with total parenteral nutrition plus somatostatin had the fistulas close within a significantly shorter period of time. Moreover, this treatment was associated with a significantly lower morbidity. These preliminary results indicate that somatostatin is a useful therapeutic complement in the conservative treatment of patients with gastrointestinal fistulas.

Adult↗

PubMed1992

A comparative analysis of the neuroendocrine mechanisms regulating ovulation, affected by a unilateral implant of atropine in the preoptic-anterior hypothalamic area, in intact and hemiovariectomized adult rats.

The effects were analysed of a unilateral implant of atropine on ovulation in intact and hemiovariectomized adult rats, together with the response of the atropine-implanted rats to hormone replacement. An outer cannula directed to the left or right preoptic (POA)-anterior-hypothalamic area (AHA) was implanted into cyclic adult rats. A group of animals in oestrus was hemiovariectomized and some were also implanted with a cannula. After two consecutive 4-day cycles, the hemiovariectomized animals were implanted with atropine (23 +/- 4 micrograms) or cholesterol (25 +/- 2 micrograms) on the day of oestrus. Atropine implanted into the left side of the POA-AHA blocked ovulation and compensatory ovarian hypertrophy, whilst implants in the right side had no effects. Administration of gonadotrophin-releasing hormone (GnRH; 3.7 micrograms/kg) at 13.00 h on the expected day of pro-oestrus induced ovulation in six out of seven treated animals. Of 19 rats with an implant of atropine in the left side of the POA-AHA, one ovulated after treatment with pregnant mare serum gonadotrophin (PMSG) on oestrus, or oestradiol benzoate or human chorionic gonadotrophin (hCG) on day 2 of dioestrus. The effects on ovulation of a unilateral implant of atropine into the POA-AHA of cyclic adult rats and the responses of such rats to GnRH, PMSG, hCG and oestradiol benzoate replacement were also studied. Ovulation was induced in rats with a unilateral implant of atropine and which had been treated with GnRH or hCG at 13.00 h on the expected day of pro-oestrus after the implant.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1992

Effects of three-month doses of ivermectin on adult Onchocerca volvulus.

Onchocerca volvulus worms in nodules from Guatemalan patients treated with four, eight, or 11 single doses of ivermectin (150 micrograms/kg of body weight) that were given once every three months were examined by routine histologic techniques and compared with worms in control nodules from untreated persons living in the same location over the same time periods. All treated nodules were removed four months after the last dose of ivermectin, i.e., 13, 25, or 34 months after the start of the trial. At the 25th and 34th months, i.e., after the eighth or eleventh doses of ivermectin, there were excess mortalities in female worms of 25.5% and 32.6%, respectively, over and above the levels in controls. Furthermore, the proportions of live females still producing scanty embryos up to the gastrula stage were only 7.7% and 18.2%, and no females were producing microfilariae. Ivermectin given at 3-month intervals also reduced significantly the mean numbers of live male worms in nodules, as well as the proportions of inseminated females. This regimen was effective in preventing embryogenesis to the microfilarial stage while, at the same time, it caused a slow but steady attrition of the adult worms.

Adolescent↗

PubMed1992

Ivermectin: reduction in prevalence and infection intensity of Onchocerca volvulus following biannual treatments in five Guatemalan communities.

Residents of five hyperendemic communities located in the central focus of onchocerciasis in Guatemala were treated with ivermectin (Mectizan) or placebo every six months for 30 months. The effects of treatment on prevalence and the intensity of skin infection (microfilarial skin density [MFD]) were evaluated. Significant and persistent reductions in both of these indices were achieved by coverage of 80.7% of the eligible populations. The highest proportionate reductions in both indicators of infection occurred after the first treatment, followed by more gradual decreases through the fourth treatment. In one community in which the mean coverage was 92.7%, prevalence decreased from 74.0% at pretreatment to 34.9% after four treatments, while the MFD decreased from 7.8 to 2.0; reductions of 52.8% and 74.3% from pretreatment values, respectively. In every ivermectin-treated community except one, in which drug acceptance was low, the mean community MFD values were reduced to the level associated with low infectiousness for the vector, Simulium ochraceum. Moreover, the category of MFD associated with high vector infectiousness was reduced at least ten-fold over the pretreatment level. One community had low participation during the first two treatments (32.8% and 22.7% of those eligible). This increased to 55.2% at the third treatment because of implementation of an educational program describing both the disease and the beneficial effects of ivermectin and because skin biopsies and nodulectomies were not performed. Secondary reaction rates for all communities were 29.5%, 9.9%, 10.3%, 8.2%, and 7.1% for the first through fifth treatments, respectively. Pruritus was the most common (34.0%) secondary reaction, followed by facial edema (31.8%). All reactions were classified as mild to moderate. Recommendations for mass distribution of ivermectin in Guatemala are given.

Adolescent↗

PubMed1992

The effects of repetitive community-wide ivermectin treatment on transmission of Onchocerca volvulus in Guatemala.

The effects of biannual ivermectin treatment at the community level on transmission of Onchocerca volvulus during the dry season were measured over a 30-month period in Guatemala. In the Los Tarrales Transmission Zone, an area encompassing three villages, significant changes occurred in both the prevalence and quantity of infection in the Simulium ochraceum vector population. These included a 76% reduction in females with infective stage larvae (L3S) and an 80% reduction in number of L3S per 1,000 parous flies. Significant reductions in both the mean infective biting density (IBD) and mean transmission potential (TP) also occurred. In Santa Emilia, the prevalence of infection with L3S in S. ochraceum was significantly reduced by 77% from the baseline value. The number of O. volvulus L3S per 1,000 parous flies was also reduced by 92%. Changes in both the IBD and TP were substantial but not significant due to the high degree of variance in the occurrence of O. volvulus L3S in the vector population. This was due, in part, to the movement of infected migrant workers into the finca (coffee farm). In Los Andes, four recurrent treatments successfully blocked transmission of infective stage larvae. Prevalence (flies with all stages of developing larvae) in the vector population was reduced by 89% over the two-year period; yearly reductions in both the IBD and TP were also highly significant, ultimately ending in zero values. This finding is particularly striking since prior to treatment, Los Andes exhibited the highest IBD of the three study locations and the second highest TP.

Animals↗

PubMed1991

Condition: critical.

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Cost Control↗

PubMed1991

Okadaic acid stimulates carnitine palmitoyltransferase I activity and palmitate oxidation in isolated rat hepatocytes.

Okadaic acid parallely increased carnitine [corrected] palmitoyltransferase I activity and the rate of palmitate oxidation in isolated rat hepatocytes. Nevertheless, okadaic acid had no significant effect on the rate of octanoate oxidation. Maximal effects of okadaic acid were similar and non-additive to those of dibutyryl-cAMP, forskolin and glucagon. Results indicate that carnitine palmitoyltransferase I activity may be controlled by a mechanism of phosphorylation/dephosphorylation.

Animals↗

PubMed1991

Properties of the mitochondrial membrane and carnitine palmitoyltransferase in the periportal and the perivenous zone of the liver. Effects of chronic ethanol feeding.

Rats were fed for 35 days a high-fat diet containing either 36% of total calories as ethanol (ethanol group) or an isocaloric amount of carbohydrate (control group). Then, mitochondria were isolated from the periportal and the perivenous zone of the liver in order to study the acinar heterogeneity of the effects of prolonged ethanol administration upon the properties of carnitine palmitoyltransferase I (CPT-I) and its membrane environment. Chronic ethanol ingestion selectively decreased CPT-I activity in periportal hepatocytes but equally increased enzyme sensitivity to malonyl-CoA and enzyme energy of activation in the two zones of the liver. In control animals, mitochondrial membrane showed higher fluidity and lower degree of saturation of phospholipid fatty acyl moieties in periportal than in perivenous hepatocytes. Prolonged ethanol feeding (i) decreased mitochondrial membrane fluidity; (ii) increased the proportion of palmitic acid and decreased that of arachidonic acid in mitochondrial phosphatidylcholine and phosphatidylethanolamine, whereas it drastically reduced the content of linoleic acid and concomitantly increased that of saturated and monoenoic fatty acids in cardiolipin; (iii) suppressed the disordering effects of the addition of ethanol to mitochondrial suspensions. All these ethanol-induced alterations of membrane fluidity and fatty acyl composition were not significantly different between periportal and perivenous mitochondria. In conclusion, chronic ethanol feeding changes the activity of CPT-I in a zone-selective manner but modifies both the regulatory properties of the enzyme and the properties of its lipid environment in a non-zone-selective manner. Hence factors in addition to the properties of the mitochondrial membrane seem to be involved in the ethanol-induced alterations of the CPT-I enzyme.

Administration, Oral↗

PubMed1991

Treatment with anabolic steroids increases the activity of the mitochondrial outer carnitine palmitoyltransferase in rat liver and fast-twitch muscle.

Treatment of male rats with the anabolic steroids fluoxymesterone or methylandrostanolone increased the activity of the outer carnitine palmitoyltransferase in liver and fast-twitch muscle mitochondria. This effect was not potentiated by physical exercise and was not observed in heart and slow-twitch muscle mitochondria. Anabolic steroids did not affect the sensitivity of the liver enzyme to inhibition by malonyl-CoA. The data presented herein suggest that androgens may have an important physiological role in the regulation of fatty acid oxidation in liver and fast-twitch muscle mitochondria. In addition, our results are at odds with the notion that (most of) the metabolic effects of anabolic steroids on muscle are only evident when physical training is parallely performed.

Anabolic Agents↗