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Biomedical subjects

P Serrano

Publications and source records attributed to P Serrano.

At least 73 records · Page 4Linked to original sources
PubMed1997

Influence of type of dietary fat (olive and sunflower oil) upon gastric acid secretion and release of gastrin, somatostatin, and peptide YY in man.

The effects of adaptation to two diets differing in the type of dietary fat on the gastric acid secretory response to food and on the circulating levels of gastrin, somatostatin and peptide YY (PYY) were examined in humans. The study involved 18 cholecystectomized subjects previously submitted to a 30-day adaptation period to diets containing olive (group O) or sunflower oil (group S) as the fat source. During the experiments, physiological stimulation was achieved by ingestion of 200 ml of oleic acid- (group O) or linoleic acid-enriched (group S) liquid mixed meals. These resulted in an immediate rise in gastric pH. In group S, the return to the premeal value was completed within 60 min, and a further decline to values significantly lower than the basal ones was observed at the end of the study period. In contrast, ingestion of the meal containing olive oil attenuated and prolonged the pH decrease after the meal, this being associated with the suppression of postprandial gastrin response. Food ingestion induced no significant changes in plasma somatostatin concentration in either group, and no significant differences were revealed between them during the basal or postprandial situations. Plasma PYY levels were consistently higher in group O throughout the entire study period, although significance was reached only at resting. In conclusion, our results show that a 30-day adaptation period to diets containing olive oil as the main source of dietary fat results, compared with those containing sunflower oil, in an attenuated gastric secretory function in response to a liquid meal in humans. The effects of olive oil were associated with a suppression of serum gastrin and higher levels of PYY.

Adult↗
PubMed1997

Evidence of aspirin use in both upper and lower gastrointestinal perforation.

BACKGROUND & AIMS: Current studies lack appropriate data on aspirin and other risk factors for gastrointestinal perforation. The aim of this study was to obtain the best estimate on aspirin and nonaspirin nonsteroidal anti-inflammatory drug (NSAID) use in these patients. METHODS: In 76 consecutive patients with gastrointestinal perforation and 152 matched controls, a detailed clinical history supplemented with an objective test of current aspirin use (platelet cyclooxygenase activity) was obtained. RESULTS: Of the 76 cases, 78.9% were upper and 21% lower gastrointestinal perforations. Evidence of NSAID use was found in 71% of cases (70% upper, 75% lower) vs. 26.9% of controls (odds ratio, 6.64; 95% confidence interval, 3.6-12.2; P < 0.0001). The objective test showed 12.7% more aspirin users than clinical history alone. NSAID use was aspirin (alone or combined) in 66.6% of cases, and 59.25% was nonprescription. Other independent risk factors were smoking, alcohol, and a history of arthritis or peptic ulcer but not a positive Helicobacter pylori serology. Age, but not NSAID use, affected perforation-associated mortality. CONCLUSIONS: NSAID use is strongly associated with an increased risk of both upper and lower gastrointestinal perforation. The high prevalence of aspirin (over-the-counter) use suggests that future introduction of new NSAIDs may not have a major impact on decreasing gastrointestinal complications if other measures are not taken. Concomitant NSAID use, smoking, and alcohol use is a pervasive association.

Aged↗
PubMed1996

Comparison of outdoor and classroom ozone exposures for school children in Mexico City.

To evaluate methods of reducing exposure of school children in southwest Mexico City to ambient ozone, outdoor ozone levels were compared to indoor levels under three distinct classroom conditions: windows/doors open, air cleaner off; windows/doors closed, air cleaner off; windows/doors closed, air cleaner on. Repeated two-minute average measurements of ozone were made within five minutes of each other inside and outside of six different school classrooms while children were in the room. Outdoor ozone two-minute average levels varied between 64 and 361 ppb; mean outdoor levels were above 160 ppb for each of the three conditions. Adjusting for outdoor relative humidity, for a mean outdoor ozone concentration of 170 ppb, the mean predicted indoor ozone concentrations were 125.3 (+/- 5.7) ppb with windows/doors open; 35.4 (+/- 4.6) ppb with windows/doors closed, air cleaner on. The mean predicted ratios of indoor to outdoor ozone concentrations were 0.71 (+/- 0.03) with windows/doors open; 0.18 (+/- 0.02) ppb with windows/doors closed, air cleaner off; and 0.15 (+/- 0.02) ppb with windows/doors closed, air cleaner on. As outdoor ozone concentrations increased, indoor ozone concentrations increased more rapidly with windows and doors open than with windows and doors closed. Ozone exposure in Mexican schools may be significantly reduced, and can usually be kept below the World Health Organization (WHO) guideline of 80 ppb, by closing windows and doors even when ambient ozone levels reach 300 ppb or more.

Air Pollution↗
PubMed1995

Acute effects of ozone on the pulmonary function of exercising schoolchildren from Mexico City.

The acute effects of ozone (O3) on the change in lung function before and after exercise was assessed in 22 boys and 18 girls from 7 1/2 to 11 yr of age tested up to eight times over a 1 1/2-yr period outdoors (under a tarpaulin) at a school in Mexico City. Ozone and particulates were monitored at an adjacent government station, in the school yard, and under the tarp. Subjects were selected to oversample children with chronic respiratory symptoms, although children with active asthma under regular medication or FEV1 < 80% predicted were excluded. Of the participants, 21 had chronic cough, chronic phlegm, or ever wheeze with colds or apart from colds. Children performed two cycles of treadmill exercise (15 min) and rest (15 min) for a total of 1 h of intermittent exercise. Most subjects attained the target minute ventilation of 35 L/min/m2. Subjects exercised alternately during low ozone hours (8:00-10:00 A.M.) and during peak O3 hours (12:00-2:00 P.M.), to assure a range of exposures. On 85% of exercise days, the maximum daily 1-h average for ambient O3 exceeded the Mexican guideline of 110 parts per billion (ppb). O3 exposure during the hour of exercise was divided into quintiles, and the response was adjusted for repeated measures, subject having a cold, and prior outdoor exercise. Ambient O3 in the fifth quintile (mean = 229 ppb) was associated with a percentage change in FVC (-1.43% +/- 0.70), FEV1 (-2.85% +/- 0.79), FEF25-75% (-6.32 +/- 1.87) and FEV1 (-1.41% +/- 0.46).(ABSTRACT TRUNCATED AT 250 WORDS)

Air Pollutants↗
PubMed1994

Usefulness of thyrotropin-releasing hormone test, SMS 201-995, and bromocriptine in the diagnosis and treatment of gonadotropin-secreting pituitary adenomas.

Five patients with gonadotropin-secreting pituitary adenomas were studied. The utility of gonadotropin response to TRH stimulation in the diagnosis and follow-up of these tumors was evaluated, as well as the effects of somatostatin analogue SMS 201-995 and bromocriptine on gonadotropin release. Three patients had FSH and LH secreting adenomas while the other two tumors secreted FSH and alpha-subunit. Transsphenoidal resection of the pituitary adenomas were performed in all patients. Following preoperative TRH administration (400 micrograms i.v.), marked increases were observed in FSH levels in two cases, in LH levels in three and in alpha-subunit in one. The FSH and LH responses to t.his stimulus persisted in the same patients after surgery. Following acute bromocriptine administration (5 mg orally), FSH was reduced in all cases by 19% to 46%, LH in three cases by 50-67% and alpha-subunit in one by 33%. In patient no. 5, with persistent high FSH levels in the immediate postoperative period, long-term bromocriptine treatment was administered (15 mg/d orally), resulting in normalization of FSH levels 6 months later, although the size of the tumor was not reduced. After acute SMS 201-995 administration (100 micrograms sc) FSH decreased in two cases by 38% and 76%, LH in three by 30-56% and alpha-subunit in one by 20%. We conclude that gonadotropin response to TRH stimulation is useful in the diagnosis and follow-up of patients with gonadotroph adenoma. Bromocriptine and SMS 201-995 may be effective as coadjuvant treatment following surgery and radiotherapy in these patients, although long-term studies will be necessary to confirm these proposals.

Adenoma↗
PubMed1994

AMPA elicits long-lasting, partly hypothermia-sensitive calcium responses in acutely dissociated or cultured embryonic brainstem cells.

This study aimed at testing if, and under which conditions, long-lasting cytosolic calcium responses can be induced in dissociated embryonic brain cells exposed to alpha-amino-hydroxy-5-methyl-4-isoxazole-propionic acid (AMPA) receptor agonists. Rat brainstem cells (gestation days 13-14; mean crown-rump lengths 8-11 mm) were mechanically dissociated and loaded with the fluorescent calcium marker Fluo-3 after in vitro delays ranging from 20 min to 6 days. The cells were exposed to various concentrations of AMPA, domoic acid or kainic acid. The evoked fluorescence changes, indicating variations of cytosolic calcium, were recorded and analysed either with a video-microscope or a laser cytometer. Even at the earliest stages, non-desensitizing (or partly desensitizing) calcium responses to AMPA were found. In addition, sequential exposure to AMPA followed either by domoic acid, or by AMPA in the presence of aniracetam, revealed the existence of cells bearing predominantly desensitizing receptors. The non-desensitizing as well as desensitizing response components were blocked by 6,7-dinitroquinoxaline-2,3-dione (DNQX). When the experiments were conducted at 24 degrees C, the cytosolic calcium levels generally returned close to pre-stimulus baseline levels after washout. In contrast, when the working temperature was slightly raised (to 27 degrees C), complex secondary calcium rises were observed not only during prolonged stimulation, but also after short agonist application. The calcium modulation might be correlated with some form of cellular "learning" in the embryonic brain. Under particular conditions, where the regulation processes are either switched off by cell programmes or simply overloaded, the cascade of events comprising secondary calcium rises may lead to cell death.

Animals↗
PubMed1994

Moncrief's technique for peritoneal catheter placement: experience of a CAPD unit.

A decrease in the peritonitis rate and the incidence of catheter exit-site/tunnel (E/T) infection are the most important factors affecting the permanent peritoneal catheter in continuous ambulatory peritoneal dialysis (CAPD) patients. Moncrief et al. have introduced a novel methodology (two phases) for peritoneal catheter placement (7.8). The most relevant characteristic is that the external portion remains buried on the subcutaneous tissue (sterile environment) during the healing process. After four to six weeks, the catheter is brought out through a small incision (0.5 cm) distal 2 cm from the subcutaneous cuff, and peritoneal dialysis may be initiated. The data available, presented by Moncrief et al., show a lower incidence of peritonitis rate and E/T infection with this implantation technique, when compared with a classic technique. The aim of this study is to learn if the placement of a peritoneal catheter with Moncrief's methodology decreases the incidence of complications related to peritoneal catheters. We treated 29 patients (group C) with the conventional procedure and 25 patients (group M) with the Moncrief technique. Follow-up was similar for both groups (C = 12.2 +/- 7.9 months vs M = 11.1 +/- 6.1 months, NS). The time buried was 3.23 +/- 0.9 weeks (2-5). Eleven patients completed four weeks with the catheter buried subcutaneously (group M-4). The incidence of E/T infection was similar for groups C and M, and lower in group M-4 (p < 0.05). The number of catheters free of infection was less in group C (31%) than in group M (46%) and M-4 (67%) (p < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1993

Hepatitis C antibody after kidney transplantation: clinical significance.

The prevalence of antibodies to hepatitis C virus (HCV) was investigated in 231 renal transplantation recipients, by a first- and second-generation EIA assay and a second-generation immunoblot assay (4-RIBA). Before transplantation, prevalence of anti-HCV was 22.6% and was related to the time on dialysis (p < 0.01), transfusions (p < 0.01) and previous history of chronic liver disease (p < 0.01. Following transplantation, 32 patients (13.9%) were anti-HCV positive by the first-generation enzyme immunoassay (EIA) and it increased to 57 patients (24.7%) when anti-HCV was measured by the second-generation EIA. The 4-RIBA assay confirmed the positivity in 46 patients (80.7%), 11 patients (19.3%) were indeterminate. Seroconversion after grafting was observed in 7 negative patients, and another 7 patients became negative after the procedure. The presence of anti-HCV antibody after transplantation was determined by the patient status on dialysis, 80% of them being positive before surgery. Twenty-one 4-RIBA-positive transplantation patients (45.7%) had persistently or intermittently abnormalities on liver function tests, suggesting chronic liver disease. A liver biopsy performed on 10 of these patients showed; chronic active hepatitis in 6, chronic persistent hepatitis in 2, and chronic lobular hepatitis in the other 2 patients. Another 23 4-RIBA-positive transplantation patients had normal alanine aminotransferase levels despite long follow-up (66.2 +/- 32.2 months). The prevalence of anti-HCV antibody can be underestimated if the antibody is measured by first-generation EIA alone. About 50% of patients with anti-HCV had chronic liver disease, and the histological findings suggested a possible evolution to cirrhosis.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Gastric carcinoma: study of the most eminent prognostic factors.

In order to analyse some prognostic factors in relation to gastric cancer, 218 patients were included in a prospective protocol at 'Hospital General de Elche' (Spain) with a follow-up of 100%. Survival curves were calculated using Kaplan-Meier analysis and compared using the log-rank test. The number of patients who underwent resection was 122 (63.5%). In 70 cases (36.5%) the resection was not possible. The postoperative mortality was 4.9%. In the survival of patients with gastric cancer we find the following prognostic factors are significant: age, tumour site, macroscopic type, depth of gastric wall affection, presence of lymph nodes, staging, resectability and surgical intention (curative vs palliative).

Adult↗