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Biomedical subjects

M Vergara

Publications and source records attributed to M Vergara.

At least 19 recordsLinked to original sources
PubMed2006

Landfill leachate treatment using a rotating biological contactor and an upward-flow anaerobic sludge bed reactor.

This paper describes the feasibility of an aerobic system (rotating biological contactor, RBC) and a biological anaerobic system (upward-flow anaerobic sludge bed reactor) at small scale for the treatment of a landfill leachate. In the first phase of the aerobic system study, a cyclic-batch RBC system was used to select perforated acetate discs among three different acetate disc configurations. These discs were chosen on the basis of high COD removal (65%) and biological stability. In the second phase, the RBC system (using four stages) was operated continuously at different hydraulic retention times (HRT), at different rotational speeds, and with varying organic concentrations of the influent leachate (2500-9000mgL(-1)). Forty percent of the total surface area of each perforated disc was submerged in the leachate. A COD removal of about 52% was obtained at an HRT of 24h and a rotational speed of 6rpm. For the anaerobic system, the reactor was evaluated with a volumetric organic load of 3273g-COD m(-3) day(-1) at an HRT of 54, 44, 39, 24 and 17h. At these conditions, the system reached COD removal efficiencies of 62%, 61%, 59%, 44% and 24%, respectively.

Anaerobiosis↗
PubMed2005

Meta-analysis: role of Helicobacter pylori eradication in the prevention of peptic ulcer in NSAID users.

AIM: To evaluate whether eradication of Helicobacter pylori prevents peptic ulcer in non-steroidal anti-inflammatory drug users by means of a meta-analysis. MATERIAL AND METHODS: A systematic search was performed in MEDLINE, EMBASE, the Cochrane Controlled Trials Register and the AGA congress. Randomized trials comparing H. pylori eradication vs. non-eradication or eradication vs. a proton pump inhibitor in patients receiving a non-steroidal anti-inflammatory drug were selected. RESULTS: Five studies and 939 patients were included in the analysis; 34 of 459 (7.4%) patients developed a peptic ulcer in the eradicated group vs. 64 of 480 (13.3%) in the control group. The odds ratio was 0.43 (95% confidence interval: 0.20-0.93). Sub-analyses showed a significant reduction of risk for non-steroidal anti-inflammatory drug-naive (odds ratio = 0.26; 95% confidence interval: 0.14-0.49) but not for previously treated patients (odds ratio = 0.95, 95% confidence interval: 0.53-1.72). Two studies with a total of 385 patients compared eradication vs. a proton pump inhibitor; five of 196 (2.6%) developed a peptic ulcer in the eradicated group vs. zero of 189 (0%) in the proton pump inhibitor group (odds ratio = 7.43; 95% confidence interval: 1.27-43.6). CONCLUSION: Helicobacter pylori eradication reduces the incidence of peptic ulcer in the overall population receiving non-steroidal anti-inflammatory drugs. It appears to be especially effective when performed in non-steroidal anti-inflammatory drug-naïve patients. Nonetheless, eradication seems less effective than treatment with a maintenance proton pump inhibitor for preventing non-steroidal anti-inflammatory drug-associated ulcers.

Amoxicillin↗
PubMed2005

[Cecal cytomegalovirus infection following appendicectomy in a patient with ulcerative colitis].

We report a patient who, 3 months after being diagnosed with ulcerative colitis, was admitted to hospital because of malaise and right lower abdominal pain. An open appendectomy was performed. Histological study showed ulcerative colitis affecting the appendix. After surgery, the patient presented a refractory outbreak of ulcerative colitis requiring treatment with steroids and cyclosporin A. Despite this treatment, the patient continued to pass abundant fresh blood associated with severe anemia. Colonoscopy showed only granular and congestive cecal mucosa. Biopsies showed intracytoplasmic inclusion bodies with immunohistochemical stains positive for cytomegalovirus (CMV) infection. Rectorrhagia and anemia quickly disappeared after beginning treatment with ganciclovir. Appendicular ulcerative colitis is not uncommonly associated with distal colitis. In addition, diffuse CMV infection complicating ulcerative colitis treatment is not unusual. By contrast, isolated, segmentary infection by CMV in the proximal colon is extremely rare. Until now, only three patients with localized CMV infection have been described, and all three cases occurred in the context of ileoanal anastomosis.

Adult↗
PubMed2004

[Sedation in digestive endoscopy. Results of a hospital survey in Catalonia (Spain)].

INTRODUCTION: The need for sedation is increasing in digestive endoscopy units (DEU). There are no data on the use of sedation in DEU in Catalonia (Spain). OBJECTIVE: To evaluate the use of sedation in DEU in Catalonia. MATERIAL AND METHOD: A questionnaire on the practice of sedation was designed and sent to the heads of medical and nursing staff of the DEU of 63 public and private hospitals in Catalonia. Two mailings were sent with an interval of three months between each. The questionnaire included 62 items on the characteristics of the hospital and the DEU, number of explorations, frequency of sedation use, drugs employed, participation of an anesthesiologist, use of monitoring, and complications. RESULTS: Forty-four DEU (70%) corresponding to 31 public hospitals and 13 private hospitals completed the questionnaire. Evaluation of sedation patterns was based on 105,904 explorations performed in the various DEU (56,453 gastroscopies, 47,278 colonoscopies and 2,173 endoscopic retrograde cholangiopancreatographies (ERCP) in 2001. Sedation, sedation-analgesia or anesthesia was used in 17% of gastroscopies, 61% of colonoscopies and 100% of ERCP. Sedation was administered by an anesthesiologist in 7% of gastroscopies, 25% of colonoscopies and 38% of ERCP. Anesthesiologist administration was more frequent in private than in public centers (gastroscopies: 25% vs. 2%; colonoscopies: 57% vs. 9%, p < 0.001). No deaths associated with the use of sedation were reported. Eighty-nine percent of the DEU complied with standard recommendations for the practice of sedation. CONCLUSIONS: In Catalonia, the use of sedation is highly variable, depending on the endoscopic procedure and the DEU. Use of sedation in infrequent in gastroscopy, fairly widespread in colonoscopy and routine in ERCP. Anesthesiologist administration is significantly more frequent in private hospitals. Most DEU follow standard sedation practices.

Anesthesia↗
PubMed2004

Cholinergic facilitation of erection and ejaculation in spinal cord-transected rats.

Penile reflexes (PRs) were monitored in chronic spinal cord-transected rats by identifying them visually, and at the same time they were recorded as the electromyographic activity of bulbospongiosus muscles. Intraperitoneal injection of the agonist muscarine (10 microg) produced a facilitation of PRs. A decrease in the latency, an increase in the number of clusters and often an increase in the duration of cups were found after muscarine. In addition, 66% (six out of nine) of the animals ejaculated after muscarine. These results suggest that cholinergic receptor stimulation may be involved in erectile and ejaculatory mechanisms mediated by the spinal cord.

Animals↗
PubMed2003

Meta-analysis: comparative efficacy of different proton-pump inhibitors in triple therapy for Helicobacter pylori eradication.

BACKGROUND: It is not known whether certain proton-pump inhibitors are more efficacious than others when used in triple therapy for Helicobacter pylori eradication. AIM: To compare the efficacy of different proton-pump inhibitors in triple therapy by performing a meta-analysis. METHODS: A MEDLINE search was performed. Abstracts of the European Helicobacter pylori Study Group and the American Gastroenterological Association congresses from 1996 to 2002 were also examined. Randomized studies with at least two branches of triple therapy that differed only in terms of type of proton-pump inhibitor were included in a meta-analysis using Review Manager 4.1. RESULTS: Fourteen studies were included. Intention-to-treat cure rates were similar for omeprazole and lansoprazole: 74.7% vs. 76%, odds ratio (OR) 0.91 [95% confidence interval (CI) 0.69-1.21] in a total of 1085 patients; for omeprazole and rabeprazole: 77.9% vs. 81.2%, OR 0.81 (95% CI 0.58-1.15) in a total of 825 patients; for omeprazole and esomeprazole: 87.7% vs. 89%, OR 0.89 (95% CI 0.58-1.35) in 833 patients; and for lansoprazole and rabeprazole: 81% vs. 85.7%, OR 0.77 (95% CI 0.48-1.22) in 550 patients. CONCLUSION: The efficacy of various proton-pump inhibitors seems to be similar when used for H. pylori eradication in standard triple therapy.

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMed2003

A 3D biomechanical model of the hand for power grip.

A three-dimensional scalable biomechanical model of the four fingers of the hand to evaluate power grip is proposed. The model has been validated by means of reproducing an experiment in which the subjects exerted the maximal voluntary grasping force over cylinders of different diameters. The model is used to simulate the cylinder grip for two hand sizes and for five different handle diameters. The reduction of the muscle forces using different handle diameters has been studied. The model can be applied to the design and evaluation of handles for power grip and to the study of power grasp for normal and abnormal hands.

Computer Simulation↗
PubMed2002

Single vs. double dose of a proton pump inhibitor in triple therapy for Helicobacter pylori eradication: a meta-analysis.

BACKGROUND: Triple therapies combining a double dose of proton pump inhibitor plus two antibiotics are the standard treatment for Helicobacter pylori infection. Some reports suggest that the use of half the dose of proton pump inhibitor is equally effective. AIM: To compare the efficacy of a single vs. double dose of proton pump inhibitor in triple therapy. METHODS: We conducted a MEDLINE search. The search strategy included the words (pylori) AND (triple, PPI, proton pump, omeprazole, rabeprazole, pantoprazole, lansoprazole, clarithromycin, amoxicillin, amoxycillin or metronidazole). Abstracts of the articles obtained and papers presented at the European Helicobacter pylori Study Group and American Gastroenterological Association congresses from 1996 to 2001 were examined. Inclusion criteria were: (i) randomized studies with at least two branches of triple therapy including a proton pump inhibitor and two standard antibiotics; (ii) branches could differ only in terms of proton pump inhibitor dosage. A meta-analysis was conducted using conventional shareware (Review Manager 4.1). RESULTS: Thirteen studies met the inclusion criteria with a total of 2391 patients. Cure rates with double doses of proton pump inhibitor were higher in both the intention-to-treat analysis (83.9% vs. 77.7%; Peto odds ratio, 1.51; 95% confidence interval, 1.23-1.85; P < 0.01) and per protocol analysis (89% vs. 81%; Peto odds ratio, 1.96; 95% confidence interval, 1.55-2.47; P < 0.01). CONCLUSION: Triple therapies containing a single dose of proton pump inhibitor are less effective than those containing a standard double dose of proton pump inhibitor.

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMed2002

Assessing the quality of life of household members of patients with inflammatory bowel disease: development and validation of a specific questionnaire.

OBJECTIVE: Household members of patients with inflammatory bowel disease (IBD) are impacted in their daily lives by close interaction with chronic illness. However, the effect of IBD on the quality of life of household members has not been evaluated because appropriate instruments to measure it are lacking. The aim of this study was to develop and validate a specific instrument to measure the quality of life of household members of patients with IBD. METHODS: Household members were interviewed to generate an initial pool of items. A group of investigators excluded redundant and incomprehensible items, and the resulting preliminary questionnaire was completed by 81 subjects. Further item reduction was performed using the psychometric method. The psychometric properties of the final questionnaire were determined in a group of 106 subjects. RESULTS: Of the initial 67 items, 19 were excluded by investigators. The remaining 48 items were answered by 81 household members, and 32 items were excluded by factor analysis. Two others were excluded because of poor comprehension. The definitive questionnaire consisted of 14 items. CONCLUSIONS: We have developed and validated a questionnaire to measure the quality of life of household members of IBD patients. It will greatly enhance the possibilities of quantifying the effects of IBD on home life and should become a useful tool in health care planning.

Adult↗
PubMed2000

System to measure the use of the backrest in sitting-posture office tasks.

This paper presents an inexpensive and simple system to measure the way of use of the backrest. The system can be also used in field studies. It is based on a set of electrodes which, attached to the subject's back and the backrest, allows the contact area to be measured. A laboratory test was performed to validate the system. In the test the spontaneous use of the backrest in standard office chairs and tasks was studied. Four different types of backrest use have been detected, and it has been shown that they determine the lumbar curvature and pelvic inclination angles, as well as postural mobility. The comfort levels observed in the four types of backrest use were also different. Consequently, the system can be used as an indicator of back posture and comfort.

Electrodes↗
PubMed2000

[Patient assessment of the long-term benefits of surgery in inflammatory bowel disease].

UNLABELLED: The objective of surgical treatment in ulcerative colitis (UC) and Crohn's disease (CD) differs. Surgery in UC is more aggressive and potentially curative whereas in CD it is more conservative and palliative. OBJECTIVE: To assess the opinion of patients with inflammatory bowel disease who underwent surgery in the distant past about the results and timing of surgery. MATERIAL AND METHODS: A total of 50 surgical patients (36 with CD and 14 with UC) who had undergone an intestinal surgical procedure at least one year before. The clinical characteristics of patients and details of surgery procedures were recorded. Also, a personal interview was conducted. Patients were asked about their current clinical status, surgical consequences and their opinion about the appropriate timing of surgery. RESULTS: Surgery for UC was total proctocolectomy in 85% of patients and it was on an emergency basis in 43% of them. Surgery for UC was partial intestinal or colonic resection, and it was on an emergency basis in 22% of them. Postsurgical complications were more common in UC than CD patients (50% versus 20%; p < 0.05). In CD surgery, recurrence of disease occurred in 78% of patients within a 2.6 years interval. Among UC and CD patients, 71% and 50%, respectively, reported that their presurgical expectatives had been fulfilled (p = 0.17). CONCLUSIONS: Surgery for UC is associated with an appreciable rate of complications; however, most patients had their expectatives fulfilled with surgery as long-term symptoms were controlled. As for CD, the patient's satisfaction degree was lower than or UC.

Adult↗
PubMed2000

Technique to measure lumbar curvature in the ergonomic evaluation of chairs: description and validation.

OBJECTIVE: To describe and validate a system to record the lumbar curvature, specially designed for the ergonomic evaluation of chairs. DESIGN: The technique consists of a flexible goniometer and requires a model of lumbar flexion (relationship between length and angle). BACKGROUND: Most of the techniques do not allow using the backrest of the chair or do not record continuously. METHODS: Precision, repeatability and reproducibility of the measurements have been analysed, as well as the lumbar flexion model. RESULTS: A suitable lumbar model of flexion and the repeatability and reproducibility errors obtained are presented. CONCLUSIONS: The linear model is a good one to represent the flexion of the lumbar spine. The measurements are reproducible and the errors are similar or lower than with conventional inclinometers. Relevance The device may help to investigate the relationship between lumbar pain and curvature, and to evaluate the lumbar curvature in sedentary work.

Analysis of Variance↗
PubMed2000

Impact of lactation upon fertility in the New World primate capuchin monkey (Cebus apella).

In the present paper, we have studied the impact of lactation upon fertility in the capuchin monkey, Cebus apella, under laboratory conditions. Nursing females (ten females, 12 postpartum periods) presented lactational amenorrhea (first menses at 159.2 +/- 9.0 vs 42.6 +/- 5.8 days postpartum in five non-nursing females, seven postpartum periods). Plasma estradiol and progesterone concentrations during lactational amenorrhea were lower than those during the follicular phase of the menstrual cycle. Prolactin was higher than in non-nursing females at 31-60 days postpartum. Interbirth interval, studied in three non-nursing (four intervals) and six nursing females (eight intervals) lasted for 349.5 +/- 11.8 and 613.4 +/- 30.8 days, respectively. In non-nursing females, early recovery of the menstrual cycle was followed by a residual infertility (mating but no pregnancy) lasting 152.8 +/- 7.9 days. In nursing females, recovery of the menstrual cycle was followed by an extended residual infertility of 301.5 +/- 22.7 days. Thus, in the capuchin monkey, nursing prolongs the interbirth interval by inducing lactational amenorrhea and extending the residual infertility period.

Amenorrhea↗
PubMed2000

Helicobacter pylori eradication prevents recurrence from peptic ulcer haemorrhage.

BACKGROUND: Successful eradication of Helicobacter pylori infection clearly modifies the natural history of peptic ulcer disease and prevents further recurrences of duodenal and gastric ulcers. However, there are few prospective studies about actual rates of rebleeding after H. pylori eradication, a highly relevant aspect of management as re-infection, relapse of ulcer disease for other reasons (i.e. anti-inflammatory agents) or idiopathic ulcers unrelated to H. pylori may develop and cause further bleeding episodes. OBJECTIVE: To determine the incidence of bleeding episodes after eradication of H. pylori infection in patients who had bled from an H. pylori-positive peptic ulcer. PARTICIPANTS AND INTERVENTIONS: H. pylori-positive patients who bled from a gastric or duodenal ulcer were treated with appropriate triple and/or quadruple therapy. H. pylori eradication was confirmed by urea breath test 4 weeks after treatment. Patients received no further treatment but were followed clinically and additional urea breath tests were performed every 6 months. Endoscopy with antral and corpus biopsies and urea breath test were repeated as soon as patients manifested any dyspeptic symptoms that might signal recurrence. RESULTS: A total of 103 patients with bleeding duodenal ulcer were included in the study; H. pylori was successfully eradicated in 93 of these patients, who were followed for a median interval of 27 months. The yearly re-infection rate was calculated to be 0.6%. There were no instances of rebleeding in any patients during the follow-up period. CONCLUSIONS: Even after prolonged follow-up, successful H. pylori eradication prevents rebleeding.

Adult↗
PubMed2000

Effects of subinhibitory concentrations of ciprofloxacin on enterotoxigenic Escherichia coli virulence factors.

Eight enterotoxigenic Escherichia coli were studied with the aim of investigating the effect of subinhibitory concentrations of ciprofloxacin on their adherence properties and on the expression of thermolabile enterotoxin. Our data showed that the hydrophobicity on the bacterial cell surface, the hemagglutination properties, and thermolabile enterotoxin production were considerably reduced after treatment with subinhibitory concentrations of ciprofloxacin, suggesting that ciprofloxacin may be capable of decreasing adhesiveness and expression of the thermolabile toxin of enterotoxigenic Escherichia coli. In conclusion, our study supports the concept that subinhibitory concentrations of ciprofloxacin interfere with the process of host-parasite interactions such as adherence and toxin production.

Animals↗