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Biomedical subjects

R H Gilman

Publications and source records attributed to R H Gilman.

At least 109 records · Page 6Linked to original sources
PubMed1996

Metronidazole and clarithromycin resistance in Helicobacter pylori determined by measuring MICs of antimicrobial agents in color indicator egg yolk agar in a miniwell format. The Gastrointestinal Physiology Working Group of Universidad Peruana Cayetano Heredia and the Johns Hopkins University.

Resistance of Helicobacter pylori to metronidazole often causes failure of commonly used combination drug treatment regimens. We determined the MICs of metronidazole and clarithromycin against 18 H. pylori strains from Peru using tetrazolium egg yolk (TEY) agar. The MIC results obtained by agar dilution with petri dishes were compared with the results found through a miniwell format. The results of the two protocols for measuring drug susceptibility differed by no more than 1 dilution in all cases. On TEY agar, bright-red H. pylori colonies were easy to identify against a yellow background. Sixty-one percent (11 of 18) of the strains were resistant to metronidazole (MIC, > or = 4 micrograms/ml) and 50% (9 of 18) were resistant to clarithromycin (MIC, > or = 0.125 micrograms/ml), whereas none (0 of 5) of the strains tested were resistant to tetracycline (MIC, > or = 1 micrograms/ml). Thus, the prevalence of metronidazole and clarithromycin resistance in Peru is higher than that in developed regions of the world. The miniwell plate with TEY agar allows easy H. pylori colony identification, requires about one-third less of the costly medium necessary for petri dish assaying, conserves space, and yields MICs equivalent to those with agar dilution in petri dishes.

Agar↗
PubMed1996

Effective, single-dose treatment or porcine cysticercosis with oxfendazole.

The pig is a vital link in the transmission cycle of Taenia solium, the cestode responsible for human-porcine cysticercosis. Infected pigs also represent an important source of economic loss to farmers in developing countries. Past efforts to find an adequate therapeutic regimen to treat this parasite disease in swine have failed because of low efficacy, high cost, side effects, or the need for multiple doses. In this randomized, no treatment-controlled study, the efficacy and safety of oxfendazole and praziquantel for the treatment of porcine cysticercosis were evaluated in 16 naturally infected pigs. Four groups of four pigs were treated with oxfendazole, praziquantel, oxfendazole plus praziquantel, or untreated. The pigs were humanely killed 12 weeks post-treatment, the number of cyst was counted, and parasite viability was assessed by cyst evagination. No detectable side effects were seen in any of the pigs. Praziquantel treatment alone appeared to reduce the number of cysts, but did not decrease the viability of the remaining parasites. Treatment with oxfendazole alone or oxfendazole plus praziquantel killed all of the parasites, and left only microcalcifications in the meat. Oxfendazole provides, for the first time, a practical, effective, inexpensive, and single-dose therapy for porcine cysticercosis.

Animals↗
PubMed1995

Community infection ratio as an indicator for tuberculosis control.

The epidemiology of tuberculosis remains poorly understood. We investigated the relative importance of within-household and community transmission of infection among children aged 6 months to 14 years living in a Peruvian shanty-town. The prevalence of Mycobacterium tuberculosis exposure among 175 contact children (sharing a household with a person who had confirmed pulmonary tuberculosis) and 382 control children (living in nearby households free of active tuberculosis) was defined as the proportion of children with a positive purified protein derivative (PPD) skin-test. 97 (55%) contact children and 129 (34%) controls were PPD positive. Living in a contact household (odds ratio 1.74, 95% CI 1.11-2.73) and age (1.11, 1.06-1.18) were significant risk factors for PPD positivity. We calculated the community infection ratio (CIR) as the odds ratio of PPD-positive controls to PPD-positive contacts: CIR = [formula: see text] A low CIR therefore suggests mainly household spread of infection, whereas a high value suggests frequent transmission outside the household. The adjusted odds ratio (for age, sex, within-household correlation, and household size) was 0.40 (95% CI 0.26-0.64), compared with values of 0.18-0.37 in studies elsewhere. Currently recommended tuberculosis control strategies are suitable for areas with low CIRs. Different strategies may be needed for areas, such as that we studied, with high values.

Adolescent↗
PubMed1995

The role of pulse oximetry. Its use as an indicator of severe respiratory disease in Peruvian children living at sea level. Respiratory Group in Peru.

OBJECTIVE: To evaluate pulse oximetry as a technique for diagnosing pneumonic and nonpneumonic acute lower respiratory tract infection (ALRI) in Peruvian children. DESIGN: Children with acute respiratory infection were diagnosed with hypoxemia by pulse oximetry, with ALRI by the World Health Organization (WHO) algorithm and clinical examination, and with pneumonia by radiographic examination. Diagnoses were compared using kappa analysis. SETTING: Pediatric emergency department. PATIENTS: Peruvian pediatric patients with acute respiratory infection (n = 269) and well children (n = 162). MAIN OUTCOME MEASURES: Hypoxemia (arterial oxygen saturation < 96.6% of the mean arterial oxygen saturation of well children -2 SD). RESULTS: Children with pneumonic and nonpneumonic ALRI (59%, 160/269) had a mean (+/- SD) arterial oxygen saturation significantly lower than well children (93.8% +/- 3.5% vs 98.7% +/- 1.51%; P < .01). Pulse oximetry detected 88% and the WHO algorithm 90% of cases of pneumonic ALRI. The WHO algorithm and pulse oximetry detected 72% of radiologic pneumonia. Pulse oximetry misclassified notably fewer well children than did the WHO algorithm (4% vs 35%). Pulse oximetry and the WHO algorithm together (SATWHO) detected 99% and 87% of pneumonic ALRI and radiologic pneumonias, respectively, and both methods detected 94% of all cases of pneumonic and nonpneumonic ALRI diagnosed clinically. CONCLUSIONS: Pulse oximetry and the WHO algorithm are practical, helpful, and appropriate for use in developing countries to identify children with pneumonic and non-pneumonic ALRI who require treatment. The SATWHO is highly sensitive for detecting children with ALRI.

Acute Disease↗
PubMed1995

Factors associated with Taenia solium cysticercosis: analysis of nine hundred forty-six Peruvian neurologic patients. Cysticercosis Working Group in Peru (CWG).

In most developing countries, 10% of acute neurologic cases are patients with neurocysticercosis (NCC). Determining specific factors associated with contracting NCC will facilitate its diagnosis and prevention. We examined multiple socioeconomic, demographic, environmental, medical, and behavioral characteristics of 946 Peruvian neurologic patients for a correlation with NCC, which was diagnosed by the highly specific and sensitive electroimmunotransfer blot (EITB) or immunoblot assay. Eighteen percent (172 of 932) of serum samples and 28% (101 of 362) of cerebrospinal fluid samples were EITB-positive. The proportion of EITB-positive persons was similar for all socioeconomic levels. Significant factors associated with NCC were: 1) being born outside Lima, 2) having raised pigs, 3) more than 20 years of age, 4) a history of seizures, and 5) a history of taeniasis. Of these factors, raising pigs is the only one that is amenable to intervention, via improvements in animal husbandry.

Adolescent↗
PubMed1995

Short report: a placebo-controlled study of Lactobacillus GG colonization in one-to-three-year-old Peruvian children.

A pilot, placebo-controlled study conducted in Peruvian toddlers in a periurban shanty-town community demonstrates that 1) a simple fluorescent antibody test performed on bacteria from colonies grown on solid culture media can be used as a presumptive screening tool for Lactobacillus GG, 2) Lactobacillus GG powder sprinkled on flavored gelatin as a nutritional supplement is well-accepted by infants and mothers in this population, and 3) daily doses of Lactobacillus GG result in efficient colonization of the gastrointestinal tract of Peruvian infants. This study demonstrates that Lactobacillus GG should be evaluated as an adjunct for diarrhea control programs at the community level as well as in hospital-based settings.

Animals↗
PubMed1995

Treatment of porcine cysticercosis with albendazole.

In a randomized, controlled study, the efficacy and safety of two different schemes of albendazole therapy for treatment of porcine cysticercosis were tested. Seventeen naturally infected pigs were divided into three groups and treated per os with albendazole (50 mg/kg single dose), albendazole (30 mg/kg every day for three days), or given no treatment, respectively. Serologic responses were monitored with the enzyme-linked electroimmunotransfer blot assay. Pigs were humanely killed 12 weeks after treatment, necropsied, and the number of parasites was recorded. Scolex evagination was used to assess viability of the cysts. Both albendazole-treated groups had significant side effects (anorexia, lethargy). Only a single viable cyst was recovered from the brain of one animal after therapy in the multiple-dose group, and the single-dose therapy left 11% of the cysts viable. In contrast, more than 90% of muscle cysts were found to be viable in the untreated group. Although albendazole therapy for three days was found to be highly effective, side effects and the need for multiple doses would still prevent its widespread use.

Albendazole↗
PubMed1995

[Helicobacter pylori and gastric cancer].

A review is done on the evidence in favor of a link between Helicobacter pylori infection and gastric cancer of the intestinal type. In countries at high risk of gastric cancer, like Perú, Hp infection begins early in life and is highly frequent and persistent. When Hp colonizes the gastric mucosa, it causes active chronic gastritis. Initially, the gastritis is of the superficial type. With time, and probably as a result of the concurrent action of nutritional, epidemiologic and immunologic modulating factors, chronic superficial gastritis may give rise to a progressive gastric pathology that leads to gastric premalignant lesions (chronic atrophic gastritis, intestinal metaplasia and dysplasia of the gastric mucosa) and increases the predisposition to gastric cancer. The principal modulating factors are described. The epidemiology of gastric premalignant lesions in Perú is also described. Finally, a discussion is done on the effect that eradication of Hp infection might have on the prevalence of gastric cancer.

Adolescent↗
PubMed1994

Discrepancies between cerebral computed tomography and western blot in the diagnosis of neurocysticercosis. The Cysticercosis Working Group in Peru (Clinical Studies Coordination Board).

Serum samples from sequential patients who underwent cerebral computed axial tomography (CT) scan in a Peruvian radiologic clinic were tested by the highly sensitive and specific enzyme-linked immunoelectrotransfer blot (EITB) test to detect antibodies to Taenia solium. The results of the EITB test were compared with those obtained by CT scan for the diagnosis of neurocysticercosis. Of the 383 patients sampled, 32 (8%) were seropositive. The results of CT and EITB were frequently discrepant. When compared with the EITB assay, the CT scan was 44% sensitive and 95% specific. The sensitivity of CT increased to 63% if less specific images (single calcifications, granulomas, or hydrocephalus) were included. The CT scan for diagnosis of cysticercosis can best be used in conjunction with a reliable serologic test such as the EITB.

Adolescent↗
PubMed1994

Distribution of hydatidosis and cysticercosis in different Peruvian populations as demonstrated by an enzyme-linked immunoelectrotransfer blot (EITB) assay. The Cysticercosis Working Group in Peru (CWG).

A serosurvey for human hydatidosis and cysticercosis was performed in different regions of Peru. Those regions included a known endemic area for cystic hydatid disease, a cooperative in the central Peruvian Andes near the city of Tarma, Department of Junin; three areas endemic for cysticercosis in the Departments of Ancash, Cuzco, and San Martin, where the status of hydatid disease is not well defined; and an urban shantytown near Lima, where neither zoonosis is known to be present. A seroprevalence for hydatidosis 1.9% (6 of 309) was found with both the enzyme-linked immunoelectrotransfer blot (EITB) and double diffusion assays in the area endemic for hydatidosis. Seroprevalence in the other zones tested was zero using only the EITB assay. Cysticercosis seroprevalence was high in pig-raising zones but low in the high-altitude, sheep-raising areas and in the seaport of Callao. No cross-reactions between Echinococcus granulosus and cysticercosis were noted in any of the regions studied. Hydatid infection remains a major health problem in the central Peruvian Andes where sheep raising is widely practiced; however, in those regions where mainly swine are raised, human hydatid infection is not a problem.

Abattoirs↗
PubMed1994

The epidemiology of Helicobacter pylori in Peruvian children between 6 and 30 months of age.

OBJECTIVES: Cross-sectional studies of children in developing countries show a high prevalence of Helicobacter pylori infection at 6 months of age, but a decrease in the prevalence of infection between 1 and 5 yr of age. The decrease suggests a loss or clearance of infection, an uncommon finding in adults. Our objective in this study was to determine the longitudinal persistence of H. pylori infection in young children. METHODS: We tested an initial cohort of 105 6-month-old infants at 6-month intervals with the 13C-urea breath test; 56 subjects were successfully studied for 2 yr or until 30 months of age. RESULTS: Overall prevalence decreased from 71.4% to 47.9% when children were between 6 and 18 months of age, and we found a significant gender difference (males 63.6-55.0%, females 80.0-38.7%, p = 0.03). Of the 56 subjects, six had negative breath tests at all 6-month intervals, 10 were consistently positive, and 36 subjects had one or more negative tests after a positive test. The overall probability of acquiring H. pylori in a given 6-month period ranged between 0.28 and 0.38; the probability of clearing the infection was between 0.22 and 0.45. During the first 18 months after birth, male infants were more likely to acquire H. pylori and less likely to clear the infection than female infants. CONCLUSION: We conclude that H. pylori colonization in infants may be a reversible process.

Breath Tests↗
PubMed1994

A new coccidian parasite (Apicomplexa: Eimeriidae) from humans.

A new coccidian parasite has been found in stool specimens of humans with and without diarrhea. The oocyst of this parasite measures 8.6 microns in diameter (7.7-9.9 microns), with ovoid sporocysts 4.0 x 6.3 (3.3-4.4 x 5.5-7.1) microns. Each oocyst has 2 sporocysts and each sporocyst contains 2 sporozoites. Based on these characteristics and the structures observed by electron microscopy, this parasite has been classified in the genus Cyclospora. We propose the name Cyclospora cayetanensis n. sp. for this new human parasite.

Animals↗