Biomedical subjects
Publications and source records attributed to M Dehesa.
The susceptibilities to three antimicrobials of 195 Helicobacter pylori strains isolated from Mexican patients is reported; 80% of the strains were resistant to metronidazole, 24% were resistant to clarithromycin, and 18% presented a transient resistance to amoxicillin. Resistance to two or more antimicrobials increased significantly from 1995 to 1997.
Studies examining associations between Helicobacter pylori virulence markers and disease have concentrated on adults in developed countries. This study assessed adults and children in Mexico. Ninety patients were recruited, 56 adults (37 with active peptic ulceration and 19 with no ulcers) and 34 children (all with recurrent abdominal pain and no ulcers). H. pylori was cultured from gastric biopsy specimens, and vacA alleles and cagA were typed by use of polymerase chain reaction from multiple colony sweeps. Multiple vacA types were common in single-biopsy isolates and were more frequent in adults with ulcers (95%) than in adults without ulcers (37%; P<.001) or in children (52%; P<.01). vacA s1b and cagA+ strains were more frequent in adults than in children. vacA s1 and cagA+ strains had similar frequencies in adults with and without ulcers. In conclusion, infection with multiple H. pylori strains, defined by different vacA genotypes, is common in Mexico. Such mixed infection is associated with ulcer disease. Strain populations infecting Mexican adults and children differ.
Evidence indicates that a link between peptic ulcer disease (PUD) and selected psychosomatic factors may exist. A series of 70 consecutive male and female adult patients were categorized by peptic symptoms and divided into four groups: a) controls; b) gastric ulcer (GU); c) duodenal ulcer (DU); and d) chronic non-ulcer dyspepsia (CNUD). All patients were interviewed and asked to answer a questionnaire that included demographics, medical history and the incidence of negative life events. A decreased level of activity was a predominant finding in GU, DU and CNUD patients. Family history of PUD may be correlated with CNUD. Of interest was the finding that DU and CNUD patients presented a higher incidence of negative life events when compared to the other study groups. Negative life events that produce considerable stress may predispose to peptic symptoms in certain patients.
Although some authors believe that Helicobacter pylori is the etiologic agent in chronic nonspecific gastritis, it has also been suggested that the bacterium colonizes inflamed mucosa as a secondary event. This study documents the prevalence of H. pylori in 28 patients with pernicious anemia and compares the findings with those of a group of 28 age-, race-, and sex-matched asymptomatic control subjects. All subjects underwent endoscopy with biopsy of the gastric antrum and corpus. A sample of serum was obtained before endoscopy for determination of antibodies (immunoglobulin A and immunoglobulin G) to H. pylori. The prevalence of H. pylori (by biopsy) in patients with pernicious anemia was significantly less than that in controls (11% vs. 71%, P less than 0.0001). All patients with pernicious anemia had abnormalities of corpus histology (inflammation and/or atrophy). In addition, 50% of patients with pernicious anemia had a lymphocytic infiltration of the antrum. All controls with H. pylori had gastritis, 50% having active chronic gastritis. Atrophic changes of the corpus were more commonly found in patients with pernicious anemia (75% vs. 7%, P less than 0.0001). Serology and biopsy results correlated poorly in the patients with pernicious anemia: all 5 patients with positive serology results had negative biopsy results, whereas all 3 patients with positive cultures on biopsy had negative serological studies. In conclusion, patients with pernicious anemia are protected from infection with H. pylori, and H. pylori does not passively colonize mucosa inflamed by an unrelated process.
In this study, we estimated the prevalence of Helicobacter pylori infection and histologic gastritis in 58 asymptomatic Hispanic adult volunteers (mean age, 41 years; 59% male) by endoscopic biopsy of the upper gastrointestinal tract. Forty-six subjects (79%) were found to harbor H. pylori in gastric biopsies, and all had histologic gastritis. Four other subjects were found to have gastritis in the absence of H. pylori. Similar prevalences of H. pylori and gastritis were noted in all age groups and also in American-born and immigrant Hispanics. Biopsy data and serologic studies of H. pylori antibodies correlated well. We conclude that H. pylori infection is an almost universal finding in the gastric mucosa of asymptomatic adult Hispanics, regardless of age. The clinical significance of these findings is unknown, but we speculate that H. pylori and its associated gastritis could have a role in the high incidence of gastric carcinoma in Hispanic populations.
A randomized, double-blind comparison of lactose enemas plus placebo tablets vs. starch enemas plus neomycin tablets was performed on 18 patients with acute portal systemic encephalopathy. Ten patients received starch enemas (10%; 1000 ml t.i.d.) plus neomycin tablets and 8 patients received lactose enemas (20%; 1000 ml t.i.d.) plus placebo tablets. A significant mental state improvement was demonstrated in the group of patients treated with starch enemas-neomycin tablets (p less than 0.05) and in the group of patients treated with lactose enemas-placebo tablets (p less than 0.025). Both treatments significantly improved the frequency of asterixis, ammonia blood levels, and electroencephalograms. In addition, patients treated with lactose enemas showed significant improvement in number-connection test times (p less than 0.02), and their stools showed a more acid pH (p less than 0.05). No side effects were evident with either treatment. Lactose enemas are a safe and effective treatment for acute portal systemic encephalopathy.
OBJECTIVE: To compare the efficacy and tolerability of a triple vs dual pantoprazole based therapy to eradicate Helicobacter pylori (H. pylori) in mexican patients with florid duodenal ulcer. BACKGROUND: The treatment of peptic ulcer disease was revolutionized by the fact that H. pylori generally induces chronic gastritis and peptic ulcer disease and that the cure of the infection prevents ulcer relapses. MATERIAL AND METHODS: 74 H. pylori positive patients with florid duodenal ulcer were randomized to receive either pantoprazole 40 mg bid in combination with clarithromycin 500 mg tid and amoxicillin 1 g bid (triple regimen PAC) or pantoprazole in combination with clarithromycin and placebo (dual regimen PC) during 14 days. To ensure complete ulcer healing all patients received an additional 2 weeks treatment with pantoprazole 40 mg od. 14C Urea Breath test (UBT) was the main criteria used to determine eradication rate with < 150 disintegrations per minute (DPM) to consider a patient eradicated. In all patients culture, antibiotic susceptibility (E-test) and histology were performed. RESULTS: In the per protocol analysis (n = 66) the eradication rate was: PAC 93.5% vs PC 54.3% (p < 0.001). 76% of H. pylori strains were resistant to metronidazole. Tolerance and compliance were excellent in both groups. CONCLUSIONS: Triple therapy (PAC) was shown to be superior to dual therapy (PC) for H. pylori eradication in mexican patients with florid duodenal ulcer.
There are several diagnostic methods for Helicobacter pylori infection, some of them need an endoscopic procedure and biopsy to be performed (invasive) like the rapid urease test, culture and histology. Recently non invasive, specific, sensible, easy to perform and patient's well accepted methods had been developed known as breath test, based on the hydrolysis of labelled urea by Helicobacter pylori urease enzyme, to release ammonia and bicarbonate. Labelled CO2 reaches the bloodstream and the lungs, from where can be collected into the breath for quantification. Labelled urea has to options: 13C stable, non-radioactive and 14C unstable, radioactive. Breath test with 13C is based on the atomic mass difference between 12C and 13C and it is necessary a mass spectrometer and 40 minutes to perform it. Breath test with 14C has 1 uCi (one micro-curie) of radioactivity (1/300 of total radiation received in one year from the environment); the test takes 10 minutes and the samples are read in a beta counter. Both non-invasive tests had demonstrated sensitivity and specificity comparable to established "gold standards" for Helicobacter pylori infection diagnosis.
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We informed four cases of primary sclerosing cholangitis associated with chronic ulcerative colitis, diagnosed in the Gastroenterology Department, Hospital de Especialidades del CM Siglo XXI Mexico City, during 1987 to 1988. The mean age was 30.2 years and the evolution of colitis was 6.6 years. Two patients were females and two males, all presented active colitis and three presented hepatic symptoms. The laboratory abnormalities were hypertransaminasemia, increased alkaline phosphatase and hyperbilirubinemia. In three patients endoscopic retrograde cholangiopancreatography was done, in all cases diagnosis was established by histology. The frequency of primary sclerosing cholangitis associated with chronic ulcerative colitis was 13.3%.
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The determination of serum and urinary amylase are methods used in the diagnosis of acute pancreatitis, however there are many abdominal problems that can cause hyperamylasemia, in the absence of pancreatic disease, for this reason in 1969 Levitt and col. signaled the possible advantages of amylase/creatinine clearence ratio, in the clinical diagnosis of acute pancreatitis. This test was used in cases with acute pancreatitis, as in other diseases, in correlation with levels in normal subjects, with the objective of evaluating its clinica utility, in relation to the formentioned paragraph. Results concluded that the amylase/creatinine ratio is not of greater diagnostic utility than the determination of urinary amylase, in acute pancreatitis.
The authors employed this new technique of thin needle percutaneous cholangiography in 220 patients with the following results: 99.3% (146/147) success with previous biliary tract dilatation and 79.4% (53/73) success in patients with normal caliber bile ducts. The overall result of 92.7% (204/228) emphasizes that radiological opacification is the best way to study the icteric patient. Only 1.8% of patients with serious complications is less than in other instrumentation methods. By not requiring specialized equipment and being accessible in the majority of hospitals, study cost is reduced. In conclusion, this new technique of percutaneous cholangiography is preferable for accessibility, efficacy, cost and risk in the study of the icteric patient.