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Biomedical subjects

R H Gilman

Publications and source records attributed to R H Gilman.

At least 73 records · Page 4Linked to original sources

Oxfendazole treatment of sheep with naturally acquired hydatid disease.

A blinded, randomized placebo-controlled trial assessed the efficacy and safety of oxfendazole for the treatment of ovine hydatid disease. Cyst fertility and parasite viability were measured following daily, weekly, and monthly treatment schedules with 30 mg of oxfendazole per kg of body weight. The 12-week trial was conducted in 215 adult sheep in the central Peruvian Andes and was masked for both treatment group and scheduling. In this trial oxfendazole significantly reduced protoscolex viability relative to controls in all treatment groups. In the daily, weekly, and monthly groups, 100, 97, and 78% of sheep, respectively, were either cured or improved following treatment, compared to 35% cured or improved animals in the control group. However, daily dosing at 30 mg of oxfendazole per kg proved highly toxic to sheep, resulting in a 24% death rate in the daily group as compared to a 4 to 6% mortality rate in all other groups. If found safe in humans, oxfendazole may prove to be a useful and inexpensive treatment for cestode infections in humans. This study suggests that a staggered dosing regimen of oxfendazole, and possibly other benzimidazoles, may be as efficacious as daily treatment regimens for hydatidosis while decreasing both the cost and adverse effects associated with daily dosing.

Animals↗

Development of a serologic assay to detect Taenia solium taeniasis.

We developed a serologic assay to identify adult Taenia solium tapeworm carriers using excretory/secretory (TSES) antigens collected from in vitro cultured T. solium tapeworms. To identify taeniasis-specific antigens we used an immunoblot assay with serum samples from T. solium tapeworm carriers and cysticercosis patients. Antigens were identified that reacted with antibodies present in serum samples from taeniasis cases and not with those from cysticercosis patients. Using serum samples collected from persons with confirmed T. solium tapeworm infections, the test was determined to be 95% (69 of 73) sensitive. Serum samples (n = 193) from persons with other parasitic infections, including T. saginata tapeworm infections, do not contain cross-reacting antibodies to TSES, indicating that the assay is 100% specific. These data suggest that the immunoblot assay using TSES antigens can be used to identify persons with current or recent T. solium tapeworm infections and provides a new, important tool for epidemiologic purposes, including control and prevention strategies.

Adult↗

Effects of Cryptosporidium parvum infection in Peruvian children: growth faltering and subsequent catch-up growth.

The authors conducted a 2-year (1989-1991) community-based longitudinal study in a shantytown in Lima, Peru, to examine the effect of Cryptosporidium parvum infection on child growth during the year following the onset of infection. A cohort of children, aged 0-3 months at recruitment, was followed monthly for anthropometrics, weekly for stool samples, and daily for diarrheal status. Data from 185 children in the cohort permitted a comparison of growth in C. parvum-infected and noninfected children. The analyses fitted smooth, flexible curves with a linear random-effects model to estimate growth differences between C. parvum-infected and noninfected children. Children infected with C. parvum experienced growth faltering, both in weight and in height, for several months after the onset of infection, followed by a period of catch-up growth. Younger children took longer to catch up in weight than did older children. Catch-up growth, however, did not occur in children infected between ages 0 and 5 months. These children did not catch up in height, and one year after infection they exhibited an average deficit of 0.95 cm (95% confidence interval (CI) 0.38-1.53) relative to noninfected children of similar age. Stunted children who became infected also did not catch up in either weight or height, and one year after infection they exhibited a height deficit of 1.05 cm (95% CI 0.46-1.66) relative to noninfected, stunted children of similar age. These results indicate that Cryptosporidium parvum has a lasting adverse effect on linear (height) growth, especially when acquired during infancy and when children are stunted before they become infected.

Animals↗

Hyperendemic pulmonary tuberculosis in a Peruvian shantytown.

Estimates of the incidence of pulmonary tuberculosis in developing countries are based on case reporting from local health laboratories or the annual risk of tuberculin skin test conversion. Because these methods are problematic, the authors used a multiple case ascertainment method to estimate the incidence of pulmonary tuberculosis from 1989 to 1993 in a Peruvian shantytown of 34,000 inhabitants. Two methods, face-to-face interview of all local inhabitants and examination of local laboratory smear records, were used for case gathering. The number of missed cases was estimated by capture-recapture analysis. Survey cases with positive smears were matched to age- and sex-matched controls and interviewed about socioeconomic conditions. The average annual incidence per 100,000 population was 364 (95% confidence interval 293-528) by capture-recapture methods. For the city encompassing the shantytown, the Peruvian Ministry of Heath reported an average annual incidence of 134 cases per 100,000 population. The authors conclude that, in Peru, alarming clusters of pulmonary tuberculosis are masked by government reports that pool zones of disparate incidence. Existing estimators of pulmonary tuberculosis incidence based on tuberculin conversion rates may be invalid in such areas. Within these hyperendemic areas, persons suitable for intensive prophylaxis efforts cannot be reliably identified by housing and socioeconomic risk factors.

Adult↗

Cyclospora cayetanensis.

Cyclospora cayetanensis is a coccidian pathogen in humans. Cyclosporiasis is characterized by mild to severe nausea, anorexia, abdominal cramping, and watery diarrhea. Cyclospora has now been described from patients with protracted diarrheal illness in North, Central and South America, the Caribbean, Africa, Bangladesh, south-east Asia, Australia, England, and eastern Europe, and is characterized by marked seasonality. Routes of transmission are still unknown, although the fecal-oral route, either directly or via water, is probably the major one. A recent outbreak in the USA suggested transmission of Cyclospora by ingestion of contaminated berries. Cyclospora oocysts can be detected by phase contrast microscopy, modified acid-fast staining, autofluorescence, and amplification by the polymerase chain reaction. Oocysts are not sporulated when excreted in the feces, and sporulated oocysts are needed for infection. Each sporulated oocyst contains two sporocysts and each sporocyst contains two sporozoites. Humans seem to be the only host for this parasite. Histopathological examination of jejunal biopsies from infected individuals showed mild to moderate acute inflammation of the lamina propria and surface epithelial disarray. Parasitophorous vacuoles containing sexual and asexual forms of Cycl. cayetanensis were located in the cytoplasm of epithelial cells. Cyclospora infections can be treated successfully with trimethoprim-sulfamethoxazole.

AIDS-Related Opportunistic Infections↗

Intestinal parasites of the grey fox (Pseudalopex culpaeus) in the central Peruvian Andes.

The intestines of 20 grey Peruvian foxes (Pseudalopex culpaeus) were examined for the presence of Echinococcus granulosus and other intestinal parasites. Echinococcus granulosus was not found in foxes but Taenia hydatigena and T. multiceps were found in 7 and 4 animals respectively. The grey fox may not be a suitable definitive host for E. granulosus. However, it may act as a sylvatic reservoir of T. hydatigena and T. multiceps in the central Peruvian Andes.

Animals↗

Diarrhea and Clostridium difficile infection in Latin American patients with AIDS. Working Group on AIDS in Peru.

Diarrhea and wasting are among the most debilitating and deadly manifestations of AIDS, yet only limited information is available regarding the etiology, clinical consequences, and immunologic effects of infection with diarrheal agents. Peruvian AIDS patients presenting with and without diarrhea were followed prospectively to examine the relations among diarrheal pathogens, clinical presentations, CD4 lymphocyte count, weight loss, and survival. Patients with chronic diarrhea had lower CD4 lymphocyte counts (P = .001) and lost more weight (P < .001). Weight loss and a decreased CD4 lymphocyte count were associated with increased mortality (P = .011 and P = .003, respectively). Mean CD4 lymphocyte count varied significantly by diarrheal agent. Clostridium difficile was the most prevalent pathogen and was associated with significantly increased mortality before and after adjustment for coinfection, length of follow-up, CD4 lymphocyte count, and weight loss (P = .006). C. difficile may be a more important and more prevalent etiologic agent in AIDS than previously recognized and may represent a preventable cause of death in patients with immunosuppression.

AIDS-Related Opportunistic Infections↗

Detection of Cyclospora cayetanensis in wastewater.

Cyclospora cayetanensis causes diarrheal disease worldwide without a confirmed mode of transmission. Wastewater was examined for the presence of this organism. Oocysts were detected microscopically, and their identity was confirmed by molecular techniques. These findings verify that current techniques can isolate Cyclospora oocysts and suggest that fecally contaminated water may act as a vehicle of transmission.

Animals↗

Elevated concentrations of eotaxin and interleukin-5 in human neurocysticercosis.

Symptomatic neurocysticercosis, a major cause of epilepsy worldwide, results from inflammation around Taenia solium larvae, but the mechanisms are unknown. Eotaxin, not previously reported in cases of human infection, and interleukin-5 (IL-5) but not IL-8 concentrations were elevated in patient serum, and IL-5 levels were also elevated in cerebrospinal fluid (CSF). Eosinophil-selective mediators may be involved in the pathogenesis of cysticercosis. IL-6 concentrations were also elevated in patient CSF, possibly indicative of an acute-phase response.

Adult↗

Rapid, low-technology MIC determination with clinical Mycobacterium tuberculosis isolates by using the microplate Alamar Blue assay.

A colorimetric, microplate-based Alamar Blue assay (MABA) method was used to determine the MICs of isoniazid (INH), rifampin, streptomycin (SM), and ethambutol (EMB) for 34 Peruvian Mycobacterium tuberculosis isolates (including both pansensitive and multidrug-resistant strains) and the H37Rv strain by using bacterial suspensions prepared directly from solid media. Results for all isolates were available within 8 days. Discordant results were observed on initial tests for 3 of 16 INH-susceptible isolates, 5 of 31 EMB-susceptible isolates, and 2 of 4 SM-resistant isolates (by the BACTEC 460 system). The overall agreements between the MICs obtained by MABA and the results obtained with the BACTEC 460 system were 87.9% for initial results and 93.6% after retesting 12 of 17 samples with discrepant results. Interpretation of MABA endpoints improved with technical experience. The MABA is a simple, rapid, low-cost, appropriate technology which does not require expensive instrumentation and which makes use of a nontoxic, temperature-stable reagent.

Antibiotics, Antitubercular↗

Antimicrobial susceptibility of Helicobacter pylori determined by the E test using tetrazolium egg yolk agar.

Metronidazole and tetracycline E tests were compared to an agar dilution method for the antimicrobial susceptibility testing of Helicobacter pylori. Sixteen strains were tested by using tetrazolium egg yolk (TEY) agar. The characteristic E test inhibition ellipse was clearer on TEY agar than on standard blood agar and gave results comparable to those of the agar dilution test. The use of TEY medium is preferable to that of blood agar medium in E test MIC determinations for H. pylori.

Agar↗

Reference values for pulse oximetry at high altitude.

OBJECTIVE: To determine reference values for oxygen saturation (Sao2) in healthy children younger than 5 years living at high altitude. DESIGN: One hundred and sixty eight children were examined for Sao2 at 4018 m during well child visits. Physiological state was also noted during the examination. RESULTS: The mean Sao2 was 87.3% (95% confidence intervals (CI) 86.7%, 87.9%) with a median value of 87.7%. A significant difference was observed in Sao2 between children younger than 1 year compared with older children, although the difference was no longer demonstrable when sleeping children were excluded. CONCLUSIONS: This study has provided a reference range of Sao2 values for healthy children under 5 years old so that pulse oximetry may be used as an adjunct in diagnosing acute respiratory infections. Younger children were also shown to have a lower mean Sao2 than older children living at high altitude, which suggests physiological adaptation to high altitude over time. In addition, sleep had a lowering effect on Sao2, although the clinical importance of this remains undetermined.

Aging↗

Adverse effects of high-dose vitamin A supplements in children hospitalized with pneumonia.

OBJECTIVE: To test the hypothesis that high-dose vitamin A supplements will enhance recovery of children hospitalized for the treatment of community-acquired pneumonia. DESIGN: We conducted a randomized, double-blind, placebo-controlled clinical trial of high-dose vitamin A supplements among children 3 months to 10 years of age (N = 95) admitted to hospital with community-acquired pneumonia in Lima, Peru. Children </=1 year of age received 100 000 IU of water-miscible vitamin A on admission to the hospital and an additional 50 000 IU the next day. Children >1 year of age received 200 000 IU on admission and 100 000 IU the next day. RESULTS: Children receiving vitamin A (n = 48) had lower blood oxygen saturation (the mean difference on day 3 in hospital was 1.1%), higher prevalence rates of retractions (37% in the vitamin A group vs 15% in the placebo group on day 3), auscultatory evidence of consolidation (28% in the vitamin A group vs 17% in the placebo group on day 3), and were more likely to require supplemental oxygen (21% in the vitamin A group vs 8% in the placebo group on day 3) than children in the placebo group (n = 47). Adjustment for baseline severity of disease and nutritional status did not alter the association of vitamin A with increased clinical severity, although the difference in blood oxygen saturation was no longer statistically significant. No differences were seen in duration of hospitalization or in chest x-ray changes 14 days after admission. No deaths occurred, and toxicity of vitamin A was not seen. CONCLUSIONS: This study indicates that high-dose vitamin A supplements cause modest adverse effects in children recovering from pneumonia and should not be used therapeutically in such patients unless there is clinical evidence of vitamin A deficiency or concurrent measles infection.

Analysis of Variance↗

Group B streptococcal colonization in a developing country: its association with sexually transmitted disease and socioeconomic factors.

Group B Streptococcus (GBS) is an important infectious organism in pregnant women and their neonates. Although excellent data are available from the developing world, little epidemiologic information is available from Latin America. To evaluate the prevalence of GBS colonization in a developing country, a prospective study was performed in Lima, Peru. We found a relatively low prevalence of GBS colonization of 6.0% in parturient women and 10.6% in nonpregnant women. No association of GBS colonization was made with previously identified risk factors such as age, parity, or birth control practices. We did find a positive association between GBS colonization and chlamydial carriage (P < 0.05). We also report an even distribution of GBS serotypes: Ia/c = 35%, IIc = 18%, III = 29%, and V = 18%. Our study provides evidence for a low prevalence of GBS maternal carriage in this urban Latin American population.

Adolescent↗

Time-response curve of oxfendazole in the treatment of swine cysticercosis.

Human Taenia solium cysticercosis is a major cause of epilepsy in developing countries, and porcine infection causes widespread economic losses because of infested pork. Recently, the use of oxfendazole (OFZ) for porcine cysticercosis provided, for the first time, an effective, single-dose treatment. We performed a controlled study to determine the time required between treatment with a single dose of OFZ and the death of cysticerci to define its applicability as preslaughter treatment or as a field control measure. Twenty naturally infected pigs were included in this study. Sixteen received a single dose (30 mg/kg) of OFZ, and were killed in groups of four at one, two, four, and 12 weeks after treatment. Four untreated controls were killed at week 12. No adverse reactions to OFZ were noted. A clear decrease in viability and number of cysts was evident after the first week after therapy, but even at week 4 some viable cysticerci were found in all samples. Twelve weeks after treatment, all meat appeared clear and only minuscule scars remained, except in one animal that had viable brain cysts. This study confirms the efficacy of a single dose of 30 mg/kg of OFZ for porcine cysticercosis but demonstrates that preslaughter treatment of pigs with OFZ will not be useful in controlling cysticercosis. The inclusion of porcine treatment with OFZ in mass cysticercosis control programs is, however, highly promising because it is a simple, effective, inexpensive, and potentially sustainable method for decreasing the porcine reservoir of cysticercosis in disease-endemic countries.

Animals↗