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R Pimentel

Publications and source records attributed to R Pimentel.

16 recordsLinked to original sources
PubMed2004

Waterborne outbreak among Spanish tourists in a holiday resort in the Dominican Republic, August 2002.

On 3 September 2002, the Spanish national centre of epidemiology (Centro Nacional de Epidemiologia--CNE) was alerted to a high number of gastroenteritis cases in Spanish tourists who had travelled to a hotel in Punta Cana on different days during august 2002. Entamoeba hystolitica cysts have been visualised by microscopy in the stools of several patients that sought medical attention in the Dominican Republic. The CNE informed the health authorities in the Dominican Republic and conducted in conjunction an epidemiological investigation. A descriptive study of the 76 initial cases estimated a mean illness duration of 5.1+2.9 days and a exposure period of 3.6+2.2 days. Following a retrospective cohort study, the attack rate was found to be 32.4%. Consequently, 216 (95% CI=114.75-317.25) spanish tourists had probably developed the illness. Stool samples were collected in Spain from untreated patients who still felt unwell. None of the samples were positive for E.hystolitica. On 10 September, a hygiene inspection was undertaken at the hotel. Samples of the ice and meals served at the buffet that day, yielded coliform bacteria. Consumption of water from the resort water system was the only risk factor associated with the symptoms (RR= 3.55; 95% CI =1.13-10.99). To avoid similar outbreaks occurring again at the hotel, it is essential to regularly monitor the water quality and to improve food handling hygiene standards. Basic food hygiene training for food handlers should be mandatory. An international guideline for the management foodborne and waterborne outbreaks among tourists in holiday resorts should be drawn up, involving all competent authorities of both destination and tourist origin countries.

Adult↗
PubMed1999

Endoscopic ultrasound cannot determine suitability for esophagectomy after aggressive chemoradiotherapy for esophageal cancer.

OBJECTIVE: Endoscopic ultrasound (EUS) provides important information in the initial staging of patients with esophageal cancer. With recent modifications in chemoradiotherapy protocols, a significant number of patients have no residual tumor at esophagectomy. The high surgical morbidity and mortality might be avoided if complete response to chemoradiotherapy could be predicted. Previously published clinical trials, with relatively small patient numbers, have suggested that EUS may accurately stage esophageal cancer after chemoradiotherapy. The aim of this study was to verify the accuracy of EUS in staging esophageal cancer after effective chemoradiotherapy. METHODS: EUS staging was performed before and after concurrent cisplatin, 5-fluorouracil, and hyperfractionated radiotherapy in 59 patients with newly diagnosed esophageal cancer. All patients underwent subsequent esophagectomy and pathological staging. The accuracy of preoperative, postchemoradiotherapy EUS was evaluated in a retrospective fashion by comparison to pathological staging. RESULTS: After chemoradiotherapy, 18 patients (31%) had no residual disease at pathological staging (T0N0). However, EUS correctly predicted complete response to chemoradiotherapy (T0N0) in only three patients (17%). The accuracy of postchemoradiotherapy EUS for pathological T stage was only 37%, and its sensitivity for N1 disease was only 38%. EUS was unable to distinguish postradiation fibrosis and inflammation from residual tumor. CONCLUSION: When aggressive preoperative chemoradiotherapy is provided to patients with esophageal cancer, the predictive value of postchemoradiotherapy EUS is inadequate for use in clinical decision making.

Adenocarcinoma↗
PubMed1997

Characterization of transgenic tilapia lines with different ectopic expression of tilapia growth hormone.

The transfer of growth hormone (GH) genes has opened new possibilities for the manipulation of growth in economically important fish species. However, the ectopic GH levels to optimize growth acceleration in fish, and specially in tilapia, are not known and must be determined experimentally. The tilapia GH (tiGH) cDNA was used to construct chimeric genes expressing different levels of tiGH in vitro and in vivo. These constructs were used to generate four lines of transgenic tilapia by microinjection into one-cell embryos. Different patterns and levels of ectopic expression of tiGH and IGF were detected in organs of transgenic tilapia by RNA or protein analysis. The two lines with lower ectopic tiGH mRNA levels were the only ones showing growth acceleration, suggesting that the expression of ectopic tiGH promoted growth only at low expression levels. The effect of higher ectopic tiGH levels resembled the physiologic situation of low condition factor and permitted us to postulate a model for growth acceleration in transgenic tilapia expressing ectopic tiGH.

Animals↗
PubMed1996

Growth enhancement in transgenic tilapia by ectopic expression of tilapia growth hormone.

The generation of transgenic fish with the transfer of growth hormone (GH) genes has opened new possibilities for the manipulation of growth in economically important fish species. The tilapia growth hormone (tiGH) cDNA was linked to the human cytomegalovirus (CMV) enhancer-promoter and used to generate transgenic tilapia by microinjection into one-cell embryos. Five transgenic tilapia were obtained from 40 injected embryos. A transgenic animal containing one copy of the transgene per cell was selected to establish a transgenic line. The transgene was stably transmitted to F1 and F2 generations in a Mendelian fashion. Ectopic, low-level expression of tiGH was detected in gonad and muscle cells of F1 transgenic tilapia by immunohystochemical analysis of tissue sections. Nine-month-old transgenic F1 progeny were 82% larger than nontransgenic fish at p = .001. These results showed that low-level ectopic expression of tiGH resulted in a growth acceleration in transgenic tilapia. Tilapia GH gene transfer is an alternative for growth acceleration in tilapia.

Animals↗
PubMed1994

Acute lindane intoxication: a study on lindane tissue concentration and oxidative stress-related parameters in liver and erythrocytes.

Treatment of rats with daily doses of 20 mg of lindane/kg for 3 consecutive days led to the accumulation of the insecticide in several tissues, including erythrocytes and liver. Lindane did not alter the hematocrit and hemoglobin concentration but reduced methemoglobin levels by 17%. Red blood cells from controls and lindane-treated rats, exposed to t-butyl hydroperoxide, exhibited comparable rates of oxygen uptake and visible chemiluminescence, whereas the induction period that precedes oxygen uptake was significantly enhanced in the latter group. Lindane treatment did not modify the activity of erythrocyte glutathione peroxidase, glucose-6-phosphate dehydrogenase, catalase, and methemoglobin reductase, being the total content of glutathione and superoxide dismutase activity significantly increased. The liver from lindane-treated rats showed an enhanced microsomal pro-oxidant activity, evidenced by higher cytochrome P450 content and NADPH-cytochrome c reductase and NADPH oxidase activities. The higher enzyme activities led to an increased superoxide anion generation (adrenochrome formation) and lipid peroxidation (measured either by the production of thiobarbituric acid reactants and spontaneous visible chemiluminescence). Concomitantly, liver glutathione content and the activity of glutathione peroxidase-glutathione reductase couple were augmented by lindane treatment, without any change in superoxide dismutase activity, together with a reduction in that of catalase. Results suggest that lindane does not alter the prooxidant/antioxidant status of the erythrocyte in conditions of a significant cellular accumulation of the insecticide, which might exert direct action on enzymatic systems leading to enhanced superoxide dismutase activity and glutathione content.(ABSTRACT TRUNCATED AT 250 WORDS)

Adipose Tissue↗
PubMed1993

Turnover of hepatic glutathione after acute lindane intoxication.

The administration of lindane (60 mg/kg) to fed rats diminished the content of hepatic glutathione (GSH) 4 h after treatment, which was recovered at 24 h. At these experimental times, the activities of glutathione peroxidase, glutathione reductase, glutathione-S-transferases and gamma-glutamyltransferase in the liver of lindane-treated rats and control animals were comparable. Liver GSH turnover, measured after a pulse of [35S]cysteine, was enhanced by 69% (P < 0.05) in lindane-treated rats 24 h after intoxication compared to controls, with a 63% (P < 0.05) increase in the estimated rate of GSH synthesis. It is concluded that lindane enhances GSH synthesis in rat liver 24 h after treatment as a consequence of the decrement in its content observed at early times of intoxication (4 h), thus allowing the recovery of the normal level of hepatic GSH.

Animals↗
PubMed1992

Shining light on ADA.

Explore the source record for details and available documents.

Persons with Disabilities↗
PubMed1992

Wuchereria bancrofti microfilarial density of autochthonous cases and natural Culex infectivity rates in northeast Brazil.

Autochthonous Wuchereria bancrofti microfilaraemic cases from three neighbouring cities of Northeast Brazil (Recife, Jaboatao and Olinda) were selected from thick smear or filtration positive individuals and classified by their microfilarial (mf) densities through polycarbonate membrane blood filtration. Individuals were subdivided into two groups: autochthonous cases without any previous specific drug administrations (group A) and those with one or more previous DEC treatments (group B). In Recife, unlike Jaboatao and Olinda (P less than 0.05), the majority of autochthonous cases were over 20 years old and no microfilaraemics were found under the age of 10. The majority of cases in Recife had lower levels of mf density (66.6%), while in Jaboatao and Olinda higher mf carriers (65.6%) prevailed when group A (n = 141) individuals were rearranged in mf density above and below 500 mf ml-1 (P less than 0.01). All subjects in group B (n = 110) had less than 501 mf ml-1 and the great majority less than 100 mf ml-1, but a significant difference (P less than 0.05) between Recife and the two other cities was observed. Captured mosquitoes in Recife, Jaboatao and Olinda totalled 7856, 8010 and 8003 respectively. The infectivity rate found in Recife (0.61%) was significantly lower than in Jaboatao (1.21%) and Olinda (1.31%) (P less than 0.001). The authors discuss the possible influences of previous disease control programmes (medicated salt and individual treatments) applied only to the city of Recife in relation to the outcome of this investigation.

Animals↗
PubMed1991

Effects of hyperthyroidism on rat liver glutathione metabolism: related enzymes' activities, efflux, and turnover.

The effect of hyperthyroidism on liver glutathione (GSH) metabolism was studied in fed rats after the administration of 0.1 mg T3/kg body wt, for 1-3 consecutive days. T3-calorigenesis resulted in elevated rates of O2 consumption by the liver, together with higher lipid peroxidative processes and GSH depletion, compared to the euthyroid state. The study of the enzymes related to GSH metabolism revealed no significant changes in the activity of glutathione peroxidase and glutathione reductase, with decreases (27-41%) in the activity of glutathione-S-transferases and marked elevation (133%) in that of gamma-glutamyl transferase, 3 days after T3 treatment. At this experimental time, the activity of the NADPH generating enzyme glucose-6-phosphate dehydrogenase was enhanced by 84% in the liver of T3-treated rats, compared to that in the controls. In these conditions, the canalicular efflux of GSH was not altered by T3, whereas net and fractional rates of sinusoidal GSH efflux were enhanced by 86% and 288%, respectively. The latter effect of hyperthyroidism was found in parallel with an enhancement in sinusoidal lactate dehydrogenase and protein release, suggesting that loss of GSH might be related to a permeabilization of the hepatocyte plasma membrane. Liver GSH turnover assessed after a pulse of [35S]cysteine resulted in a 209% increase in the fractional turnover rate in hyperthyroid rats over controls, under steady state conditions for both hepatic GSH pools, leading to a 62% enhancement in the respective turnover flux. Data suggest that the elevation in the sinusoidal GSH efflux from the liver and in the hepatic capacity to degrade the tripeptide are major mechanisms leading to GSH depletion in the liver of T3-treated rats. As the increased GSH use is not balanced by the elevation in GSH synthesis, a lower steady state level of GSH is attained in the liver.

Animals↗
PubMed1991

Effect of phenobarbital and 3-methylcholanthrene on the early oxidative stress component induced by lindane in rat liver.

1. Lindane administered to untreated rats or rats pretreated with phenobarbital (PB) or 3-methylcholanthrene (MC) increased liver lipid peroxidation, of the same magnitude in all groups. 2. PB pretreatment produced a 50% increase in lipid peroxidation (TBAR) by liver homogenates and microsomes, an effect accompanied by increases in cytochrome P-450, NADPH-cytochrome P-450 reductase, NADPH oxidase and microsomal superoxide anion production, MC pretreatment resulted in increases in liver cytochrome P-450 and NADPH oxidase only. 3. Pretreatment of rats with PB, but not MC or lindane, gave increases in glutathione peroxidase and reductase. 4. Pretreatment with PB, but not MC, increased liver GSH. Lindane decreased liver GSH to the same extent as PB plus lindane. 5. Biliary GSH, GSSG and bile flow were decreased by lindane to similar extents in all groups. 6. Lindane induced periportal necrosis with haemorrhagic foci in all groups. 7. Data presented indicate that the early lipid peroxidative response of liver to lindane was unchanged by PB- or MC-stimulated hepatic microsomal enzyme induction.

Animals↗
PubMed1990

Failure of hepatitis B immunization in liver transplant recipients: results of a prospective trial.

Twenty patients with advanced liver disease, in need of transplantation, were given three injections of 20 micrograms and three injections of 40 micrograms hepatitis B vaccine to see if an antibody response could be obtained. Only 20% of patients developed measurable anti-HBs. One who failed to develop anti-HBs developed chronic hepatitis B after exposure to her infected sexual partner. Type of liver disease in the native liver, age, sex, sexual preference, timing of immunization (before or after transplantation), and dosage of hepatitis B vaccine did not seem to explain the lack of immunologic response to hepatitis B vaccine. It is presumed that immunosuppression, both from the underlying disease and from immunosuppressive medications, best explains our findings. Liver transplantation patients infrequently benefit from hepatitis B vaccine. It is possible that other vaccines given to prevent viral and bacterial illness may also fail to elicit immunologic response in such patients.

Adult↗
PubMed1989

Transient maternal hypotension following epidural anesthesia.

Transient maternal hypotension following regional anesthesia can lead to significantly lower umbilical cord pH values. Although this acidosis has not been found to be clinically significant, acidosis may increase the placental transfer of local anesthetic agents as a result of "ion trapping." The purpose of this study was to examine the pharmacologic and clinical consequences of transient maternal hypotension following epidural anesthesia with 0.5% bupivacaine before cesarean section. Patients were divided into two groups based on the development of maternal hypotension, defined as a systolic blood pressure less than 100 torr or a decrease of 30% or more from the preanesthetic level. Thirteen patients (33%) developed hypotension that was corrected within 2.1 +/- 1.8 min. The pH of umbilical cord venous and arterial blood and the concentration of bupivacaine were significantly lower (P less than 0.05) in neonates of mothers in the hypotensive group than in neonates of mothers that did not develop hypotension. The results show, however, that transient maternal hypotension following epidural anesthesia does not lead to a greater placental transfer of bupivacaine due to "ion trapping" even though neonatal cord blood pH decreases.

Adult↗
PubMed1987

Effects of maternal glucose infusion on fetal acid-base status in human pregnancy.

The maternal and fetal metabolic effects of three commonly used intravenous fluids administered before regional anesthesia were studied in 32 gravid women undergoing elective cesarean section at term. Patients were randomized into one of three groups to receive 1 L of either 5% dextrose (50 gm of glucose) or Ringer's lactate or isotonic saline solution before epidural anesthesia. Acute glucose infusion resulted in maternal hyperglycemia, hyperinsulinemia, and an increase in the blood lactate level. Cord blood glucose, insulin, and lactate levels were also increased in this group. The key finding of this study was the significant lowering of pH in the umbilical cord vein (7.31 +/- 0.04) and artery (7.21 +/- 0.06) in the glucose-infused group when compared with the non-glucose infusion groups (p less than 0.05). Confounding perinatal factors such as maternal position, maternal hypotension, and prolonged time of surgery did not influence the fetal acid-base status. Thus acute maternal glucose infusion in normal patients can cause fetal hyperglycemia, metabolic acidosis, and neonatal hypoglycemia. These findings may be of particular clinical importance when fetal distress or fetal hypoxemia is due to other perinatal events. Under these circumstances, acute maternal glucose infusion may further contribute to fetal metabolic acidosis.

Acid-Base Equilibrium↗
PubMedDate not supplied

[Intestinal protozoan parasitism in children from the bay of Cádiz].

The prevalence of intestinal parasitosis from protozoa in a pediatric population group attending different education centres in the Bay of Cádiz is investigated by means of directly examining the feces using microscopic techniques. The percentage of children affected by parasites is 6.3%, there being no differences with regard to sex or social level. Giardia lamblia is the most frequently found protozoa (2.7%). The level of infection from Cryptosporidium sp. (2.3%) is significant. The symptomatology of those affected was nonspecific and not intense, and therefore did not lead to any suspicion of pathology.

Child↗