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Biomedical subjects

R H Gilman

Publications and source records attributed to R H Gilman.

At least 145 records · Page 8Linked to original sources
PubMed1991

Detection of Giardia lamblia antigen in children living in a Peruvian periurban shantytown (Pueblo Joven).

Stool microscopy and an enzyme-linked immunosorbent assay (ELISA) for Giardia lamblia antigen detection were compared for detecting G. lamblia in 30 Peruvian infants. Of 1,131 fecal specimens, G. lamblia was detected by ELISA alone in 44, by microscopy alone in 17, and by both methods in 91. In another group of 17 children negative for G. lamblia by stool microscopy, 6 had G. lamblia detected by ELISA or duodenal aspiration: 2 only by ELISA, 1 only by duodenal aspirate examination, and 3 by both examinations. The ELISA is useful for the detection of G. lamblia in fecal specimens but compared to stool microscopy does not significantly increase the detection of cases.

Animals↗
PubMed1991

Helicobacter pylori and progressive gastric pathology that predisposes to gastric cancer.

Evidence is presented suggesting that infection by Helicobacter pylori triggers and continuously contributes to the pathophysiology of progressive gastric changes that can ultimately lead to gastric cancer. In Peru, especially in population groups of low socioeconomic status, infection by H. pylori begins earlier in life and is more prevalent and persistent than in developed countries. The infection produces a destructive lesion of the mucinous surface epithelium which probably enables other aggressive luminal factors to cause further mucosal damage. As a consequence, active chronic gastritis appears. The gastritis is of the superficial type at the beginning but may progressively change to atrophic. Chronic atrophic gastritis is found more frequently and at a younger age in dyspeptic patients with low socioeconomic status--that is, in patients having higher prevalence of persistent infection by H. pylori since earlier in life. When chronic atrophic gastritis becomes severe and extensive, hypochlorhydria ensues. Hypochlorhydria favors the appearance of bacterial overgrowth, nitrites, and N-nitroso compounds in the gastric lumen. N-nitroso compounds, because of their mutagenic-carcinogenic properties, probably induce gastric premalignant lesions like intestinal metaplasia and dysplasia of the gastric mucosa. Oral bismuth therapy apparently reverses H. pylori-associated gastric dysplasia. It is proposed that future programs designed for the control of gastric cancer would be incomplete if they do not include further evaluation of the many effects of infection by H. pylori on the gastric mucosa and of cost-effective methods to eradicate the infection.

Age Factors↗
PubMed1990

Fecal contamination of shanty town toddlers in households with non-corralled poultry, Lima, Peru.

We used direct observer techniques to measure the frequency with which toddler-aged children were contaminated by poultry feces in homes in a peri-urban shanty town in Lima, Peru. The mean number of fowl was 5.4 (SD 3.1), with 10.0 (SD 10.7) poultry defecations per 12 hours. Toddlers' hand contact with poultry feces occurred a mean of 2.9 (SD 3.0) times/12 hours. A mean of 3.9 (SD 4.6) feces-to-mouth episodes per household/12 hours occurred both by direct hand-to-mouth contamination and indirectly by handling soiled objects which were then placed in the mouth. There was a strong correlation between feces-to-hand contamination and feces-to-mouth contamination (r = 0.94). There was also an association between feces-to-mouth contamination and the number of stools deposited in the house (r = 0.66). For each additional chicken stool deposited during the day, there was an average increase of 0.27 in feces-to-mouth episodes. We collected feces from 68 infected chickens and found viable Campylobacter jejuni for up to 48 hours after deposition. Yet, a survey of 108 families demonstrated that free-roaming poultry were often not thought of as a health risk for children. An intervention program to reduce oral-fecal contamination should emphasize that all poultry be corralled and not allowed access into the house.

Animals↗
PubMed1990

Prevalence and comparison of serologic assays, necropsy, and tongue examination for the diagnosis of porcine cysticercosis in Peru.

Swine cysticercosis, a severe zoonotic disease which is part of the Taenia solium life cycle, causes major economic losses in pig husbandry. Throughout South America, farmers diagnose cysticercosis by examining the tongues of their pigs for cysticercus nodules. Farmers do not bring pigs believed to be infected to the slaughterhouse for fear of confiscation. Therefore, reliable statistics on porcine cysticercosis can only be acquired at the household level. We examined the utility of the tongue test as a diagnostic tool for porcine cysticercosis. The results of the tongue test was compared with 2 serologic methods for the detection of cysticercosis, the enzyme-linked immunosorbent assay (ELISA) and the enzyme-linked immunoelectrotransfer blot assay (EITB), and with necropsy results. We examined 11 animals from an endemic area (Huancayo) and 42 animals from an area free of cysticercosis (Lima). The tongue test has a sensitivity of 70% and a specificity of 100%, the EITB a sensitivity and specificity of 100%, and the ELISA a sensitivity of 79% and a specificity of 75%. Thus, the tongue examination, being a test essentially without cost and having fair sensitivity and high specificity, can be useful in epidemiological surveys. Prevalence for porcine cysticercosis in Huancayo is 23.4% by tongue examination, 31.2% by necropsy, 37.7% by ELISA, and 51.9% by EITB.

Animals↗
PubMed1990

Case-control study of Cryptosporidium parvum infection in Peruvian children hospitalized for diarrhea: possible association with malnutrition and nosocomial infection.

A retrospective, hospital-based case-control study was used to investigate whether there were any clinical characteristics that could distinguish Cryptosporidium parvum-infected children with diarrhea from other non-C. parvum-infected children with diarrhea. Ten percent (24 of 248) of children admitted to a rehydration ward at Cayetano Heredia University Hospital, Lima, Peru, were infected with C. parvum. The 24 patients infected with C. parvum (cases) were matched to an equal number of noninfected patients (controls). C. parvum-infected patients were more likely to be malnourished than were children without this infection (P less than 0.05). Also nosocomial infection caused by C. parvum occurred in three severely malnourished patients, two of whom died. No other clinical or laboratory characteristics were found that would distinguish children with diarrhea caused by C. parvum from other children with diarrhea. In children hospitalized for diarrhea C. parvum infection occurs most frequently in malnourished children.

Case-Control Studies↗
PubMed1989

General considerations in the management of typhoid fever and dysentery.

Typhoid fever is diagnosed on the basis of isolation of Salmonella typhi from blood, bone marrow, or bile. S. typhi found in stool or urine may reflect chronic asymptomatic carriage. Although antimicrobial therapy may not eliminate carriage, it is effective for the treatment of clinically evident acute disease. Among the drugs currently available, chloramphenicol is the most widely used. Chloramphenicol is effective and inexpensive, but it is associated with a 3% rate of chronic carriage, a high relapse rate, and, in rare cases, aplastic anemia. For these reasons, and because of the emergence of chloramphenicol-resistant strains of S. typhi, alternative drugs need to be considered. Dysentery is characterized by the passage of unformed stools that commonly contain blood and mucus and in which large numbers of leukocytes can be detected on microscopic examination. Invasion of the intestinal epithelium is the distinguishing characteristic, and Shigella sp are the most frequent cause. Although oral rehydration is useful in dehydrated patients, dehydration is not a common problem in acute dysentery, and antimicrobial treatment is indicated for this disease. An antimicrobial agent should be selected on the basis of knowledge of the susceptibility patterns of locally isolated Shigella strains.

Anti-Infective Agents↗
PubMed1989

Hunger pain: a poor indicator of peptic ulcer in a developing country.

Endoscopy of the esophagus, stomach, and duodenum and stool examinations for ova and parasites were performed in 63 adult Peruvian patients with "hunger pain" (HP) and other dyspeptic symptoms. No lesion capable of provoking HP was found at endoscopy in 50 (78%) of the 63 patients. Only 7 (12%) of the patients had evidence of active or healed peptic ulcers. Another 6 patients (10%) had either gastric erosions or duodenitis. One (2%) of the patients was infected with hookworm, a parasite that produces epigastric pain mimicking HP. The 12% rate of peptic ulcer in Peruvian patients with HP contrasts strongly with accumulated experience in most developed countries, whose rates of peptic ulcer associated with HP range from 60 to 75%. As the frequency of peptic ulcer is so variable in patients with HP, we suggest that the simple term "hunger pain" be used instead of "peptic ulcer pain" or "ulcer dyspepsia" to refer to the complaint of such patients.

Abdominal Pain↗
PubMed1988

Rapid reinfection by Giardia lamblia after treatment in a hyperendemic Third World community.

In a peri-urban shanty town in Lima, Peru, that was hyperendemic for Giardia lamblia, 44 children aged between 0.9 months and 10 years were effectively treated for Giardia lamblia with tinidazole. Stools were examined weekly in the 6 months after treatment to determine the rate of reinfection, and after reinfection stools continued to be examined. 98% of the children became reinfected with Giardia lamblia within 6 months, and after reinfection stool excretion of the parasite lasted a mean (SD) of 3.2 (3.3) months. The children's mean stool pH and their mean stool fat index was unaffected by Giardia lamblia reinfection. Treatment of all symptomless Giardia lamblia infections in a developing country hyperendemic for the disease is of questionable value because of rapid reinfection.

Animals↗
PubMed1988

Decreased gastric acid secretion and bacterial colonization of the stomach in severely malnourished Bangladeshi children.

To assess the effect of malnutrition on gastric acidity and gastric bacterial colonization, we studied 35 severely malnourished Bangladeshi children before (0 wk) and after (3 wk) they received nutritional rehabilitation for 3 wk. These results were compared with those obtained from a similarly examined group of 20 better-nourished Bangladeshi children. Gastric acid output, both basal and after betazole stimulation, was significantly lower in the malnourished group at 0 wk compared with the better-nourished children (p less than 0.01): basal 0.22 vs. 0.52 mEq HCl/h and stimulated 0.90 vs. 2.5 mEq HCl/h. Both the concentration of acid and the rate at which gastric juice was secreted were decreased in the malnourished group but serum gastrin levels were not significantly different. After 3 wk, the malnourished children had improved from 61% (+/- 9.0%; SD) to 81% (+/- 8.1%) of expected weight-for-height and were not significantly different than the better-nourished group (86% +/- 11%). Nevertheless, gastric acid concentration remained depressed in the 3-wk group, although the rate of gastric juice secretion equaled levels observed in the better-nourished group. None of the better-nourished children had detectable gram-negative bacterial colonization of their gastric juice. In contrast, 26 of 32 (81%) malnourished children at 0 wk were colonized--even after betazole stimulation, 11 of 33 (33%) gastric juice samples yielded viable organisms--suggesting that the decrease in gastric acid output greatly reduced the gastric acid barrier. Interestingly, only 9 of 20 (45%) better-nourished children had gastric juice with basal pH values below 4.0, suggesting that the gastric acid barrier may be an intermittent defense factor in Bangladeshi children.

Age Factors↗
PubMed1988

Seroepidemiology of Cryptosporidium infection in two Latin American populations.

An enzyme-linked immunosorbent assay was used to examine randomly selected sera from 389 children and adults in Lima, Peru, and 84 children in Maracaibo and Caracas, Venezuela, for IgM or IgG antibody to Cryptosporidium. In Peru and Venezuela, 19.8% and 15.5% of the study populations, respectively, were positive for both specific IgG and IgM antibodies, a result consistent with active or recent infection and representing a larger percentage than normally reported from stool examinations of individuals seeking medical attention. Sixty-four percent of subjects from each country had detectable levels of specific IgG, indicating infection sometime in life. Detection of specific IgG increased in the two- to three-year-old age-group, a result suggesting that this is a common age for infection. Persistence of IgG and, less often, IgM antibody response over 12 mo occurred in some subjects, although the significance of this finding is uncertain. Our findings suggest that Cryptosporidium infections are endemic in the communities surveyed and that most residents have been infected.

Adolescent↗
PubMed1987

Comparative susceptibilities of Campylobacter pylori to norfloxacin and other agents.

Twenty-one strains of Campylobacter pylori (Campylobacter pyloridis) were tested for susceptibility to norfloxacin and other agents by the serial agar dilution method. Ampicillin (MIC for 90% of isolates [MIC90], 0.016 micrograms/ml) and famotidine (MIC90, greater than 1,024 micrograms/ml) were, respectively, the most and the least active of the agents tested. Norfloxacin (MIC90, 1 microgram/ml) and imipenem (MIC90, 0.125 micrograms/ml) were substantially active against this organism.

Anti-Bacterial Agents↗
PubMed1986

Age-related rate of seropositivity of antibody to Giardia lamblia in four diverse populations.

We used a solid-phase enzyme immunoassay to determine the age-specific rates of acquisition of antibody to Giardia lamblia in populations living in an inner city area of Baltimore, Md., on an Apache Indian reservation in Arizona, in a rural area of Panama, and in an urban area of Peru (Lima). Antibody to G. lamblia was found in a portion of the adults living in all of the study areas. Similar prevalence rates and quantitative levels of antibody were found in the adults living in Arizona (44%), Panama (48%), and Peru (46%). However, a significantly lower (P less than 0.05) percentage of the adults living in Baltimore (18%) displayed serological evidence of infection. Different patterns of age-associated acquisition of antibody were noted in the study populations. In the United States, children living in Baltimore had low levels of seropositivity throughout childhood, whereas children living on the Arizona Indian reservation showed a progressive acquisition of antibody early in childhood, with adult levels achieved by 8 years of age. In Latin America, children living in Panama attained adult levels of seropositivity between 9 and 20 years of age, whereas children in Peru displayed adult levels of seropositivity in the first 6 months of life. Our findings documented the widespread occurrence of G. lamblia infections in diverse populations. Children living in different areas and under different environmental conditions displayed widely differing rates of acquisition of antibody to G. lamblia, possibly resulting from different levels of sanitation, water contamination, and person-to-person contact. Our studies indicate that quantitative solid-phase immunoassays can be used to study the epidemiology of parasitic infections such as those caused by G. lamblia.

Adolescent↗
PubMed1985

Epidemiology and serology of Giardia lamblia in a developing country: Bangladesh.

The age-specific prevalence of Giardia lamblia was determined in two Bangladeshi villages and malnourished children in hospital in Dhaka City. Age-specific acquisition rates, the duration of infection and age-specific sero-positivity to (immunofluorescent assay) G. lamblia trophozoites were determined. Infection was acquired early (less than one year) and in 16% of infected children persisted for longer than three months. Prevalence was higher in 5 to 10-year-old village children (21%) and one to five-year-old malnourished children (51%). Over 40% of the children much less than 7 years acquired G. lamblia within 18 months; acquisition rates did not change with age. Positive antibody titres were acquired between six months and one year and the prevalence of sero-positivity remained high in all age groups No association was found between positive antibody titres and positive stool examinations. In developing countries serum antibodies are useful epidemiologically, but are not diagnostic in the individual patient.

Adolescent↗
PubMed1985

The treatment of Fasciolopsis buski infection in children: a comparison of thiabendazole, mebendazole, levamisole, pyrantel pamoate, hexylresorcinol and tetrachloroethylene.

Four relatively new broad spectrum anthelmintics (thiabendazole, mebendazole, levamisole and pyrantel pamoate) were compared with two older anthelmintics, (tetrachloroethylene and hexylresorcinol) to treat heavy Fasciolopis buski infections in 17 children aged 4-13 years in hospital. Tetrachloroethylene was the most effective drug in these 17 children and another 49. Large numbers of worms were expelled and faecal egg counts were markedly reduced (99%). The mean number of worms per child was 122 with a range of 7 to 818. All the other anthelmintics tested were ineffective; no worms or only a few were expelled after treatment. However, the oral administration of tetrachloroethylene and hexylresorcinol were associated with severe anaphylactic reactions which were prevented by prior treatment with antihistamines.

Adolescent↗
PubMed1985

Prevalence of serum and milk antibodies to Giardia lamblia in different populations of lactating women.

We used an enzyme-linked immunosorbent assay system to compare prevalence and levels of systemic and local antibody to Giardia lamblia in different populations. Serial blood and milk samples were collected simultaneously from lactating women in Texas and Mexico. IgG antibody to G. lamblia was present in 118 (77%) of 153 sera from 27 Mexican mothers but in only 51 (24%) of 214 sera obtained from 28 Texan mothers (P less than .001). Sera positive for IgG antibody to G. lamblia revealed antibody levels that were significantly higher in Mexico than in Texas (0.325 +/- 0.076 vs. 0.219 +/- 0.079 optical density units). Secretory IgA antibody to G. lamblia was found in 121 (79%) of 153 milk samples in the Mexican population, but in only 33 (15%) of 214 samples in the Texan population (P less than .001). The levels of secretory antibody to G. lamblia also were higher in the Mexican population. The study documents a widely different antibody response to G. lamblia in individuals living in different areas. As antibodies to G. lamblia can be acquired by infants transplacentally or through breast-feeding, this difference might be important in the relative protection against giardial infection.

Adolescent↗
PubMed1985

Boiling of drinking-water: can a fuel-scarce community afford it?

In the prevention of diarrhoea, health professionals often advocate boiling as a method of choice to provide safe household drinking-water to villagers in the less developed countries. We have examined the financial feasibility of this recommendation in a village study in Bangladesh. Family income was categorized and the pattern of household fuel consumption was determined. Families in the lowest income quartile would have to spend approximately 22% of their yearly income on fuel, and those in the highest income bracket approximately 10%. Boiling of drinking-water would result in an 11% increase in the household budget (as a percentage of income) for a typical family in the lowest income quartile, compared with a 3% increase for a family in the highest income quartile. We conclude that recommendations concerning boiling of drinking-water in developing countries should not be made until their economic feasibility has been demonstrated.

Bangladesh↗
PubMed1984

Renal histopathology in the hemolytic-uremic syndrome following shigellosis.

The hemolytic-uremic syndrome (HUS) following dysentery caused by S. dysenteriae Type 1, characterized by microangiopathic hemolytic anemia and acute renal insufficiency, is clinically similar but not identical to the idiopathic HUS. We studied renal necropsy specimens of nine children who died of HUS following shigellosis by light and immunofluorescent microscopy and compared them to 12 controls: six cases with severe shigellosis without HUS, and six with pneumonia or sepsis. Eight of nine HUS cases showed cortical necrosis, extensive glomerular thrombosis or arterial thrombosis. Cases without HUS showed only scattered glomerular fibrin thrombin and widening of the mesangium. Among seven HUS cases studied by immunofluorescent microscopy, three demonstrated deposition of glomerular IgM and complement (C3) and one of the three had IgG and IgA as well; four cases had neither immunoglobulin or complement deposits. Among nine controls, two demonstrated IgM and three IgG, but none had C3. Both HUS and non-HUS cases had fibrin deposition. In the three HUS cases studied by electron microscopy intracapillary material (fibrin and platelets) was seen in all three, and sparse electron-dense deposits in mesangial matrix in one. The data indicate that the renal histopathology in the HUS following shigellosis consistently presents as a severe thrombotic microangiopathy, but lacks the characteristic endothelial and mesangial lesions of idiopathic HUS. The infrequent demonstration of glomerular immunoglobulin deposition fails to support an immunoglobulin-mediated pathogenesis.

Anemia, Hemolytic↗