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Biomedical subjects

H L Dupont

Publications and source records attributed to H L Dupont.

At least 37 records · Page 2Linked to original sources
PubMed1986

Emporiatric enteritis: lessons learned from U.S. students in Mexico.

In the studies reported, evidence has been presented that U.S. students traveling to Mexico represent a model for the study of travelers' diarrhea. The incidence of illness acquisition approximates that published in other studies of travelers. Natural immunity was shown to develop as students remained in Mexico presumably through repeated exposure to prevalent agents, particularly ETEC. ETEC, shigella strains and no detectable agent represented the largest groups when etiologic assessment was made. Food probably served as the important source of diarrhea particularly that due to ETEC and shigella strains. The level of bacteria isolated from food suggested that organism replication occurred due to improper temperature storage rather than to heavy initial contamination. The location of food consumption was related to degree of risk: self preparation was the safest, eating in Mexican homes the least safe and consumption of food in public restaurants was intermediate in risk. Water probably played a role in the transmission of viral infection. The risk of water contamination appeared to be highest during the rainy seasons. Finally, the antimicrobial agents TMP/SMX and TMP alone were shown to effectively prevent and treat this form of travelers' diarrhea.

Diarrhea↗
PubMed1983

Antimicrobial therapy of travellers' diarrhoea.

Two trials were carried out to evaluate antimicrobial agents in the therapy of travellers' diarrhoea. In the first, 72 students were given 500 mg bicozamycin (BI), a poorly absorbable drug, q.i.d. for three days and 68 were given a placebo. In the second, 37 students were given trimethoprim/sulphamethoxazole (160 mg TMP-SMX 800 mg), 38 TMP (200 mg), and in 35 a placebo was given b.i.d. for five days. Diarrhoea lasted on average 28 hours in those receiving BI compared to 64 hours in the placebo group (p = 0.00009). Significant shortening of diarrhoea after taking BI was seen for all subjects with illness, as well as those with ETEC diarrhoea, shigellosis and for those with unknown causes of illness. A significant clinical response was also noted in all categories of diarrhoea for both TMP-SMX and TMP when compared to placebo group.

Anti-Infective Agents↗
PubMed1977

Diarrhea of travelers to Mexico. Relative susceptibility of United States and Latin American students attending a Mexican University.

A clinic was established at Universidad de las Americas, Cholula, Puebla, Mexico for the study of acute diarrhea rates in newly-arrived students and full-time students. Diarrhea occurred in 22 of 55 newlly-arrived U.S. summer students (40%), compared to 28 of 142 U.S. full-time students (20%), 4 of 29 Venezuelan summer and full-time students (14%) and 7 of 66 Mexican full-time students (11%) (the differences were significant, p less than 0.005). Recurrent episodes of diarrhea during the month of study occurred in 15% of U.S. summer students, 4% of U.S. full-time students, and were non-existent in students from Latin America. As well as the 61 students with diarrhea enrolled in the incidence study, all students who developed diarrhea at the univeristy were encouraged to visit the clinic. This gave a total population of 130 cases of diarrhea. The illness that developed in students form the U.S. varied widely, but it typically consisted of seven to 13 unformed stools during the first 48 hours of illness, with illness persiting three to five days. Illness tended to be more severe in the U.S. students. Fifty per cent of the U.S. students with diarrhea had "severe" illness (greater than or equal to 10 unformed stools in first 48 hours) compared to 23% of the Latin Americans. This study indicates that the agents responsible for diarrhea in Latin America are widespread and that resistance to infection develops after prolonged or repeated exposure.

Diarrhea↗
PubMed1976

Antimicrobial susceptibilities of shigellae isolated in Houston, Texas, in 1974.

One hundred seventy-three strains of shigellae (113 Shigella sonnei, 56 S. flexneri, and four others) isolated in Houston during 1974 were tested for susceptibility to commonly used and newer antimicrobial agents. Forty-five percent of S. sonnei strains were susceptible to ampicillin, whereas 93% of S. flexneri strains were susceptible to that agent. S. sonnei and S. flexneri strains were equally susceptible to tetracycline (35 and 33%, respectively). All 173 strains were uniformly susceptible to quinoline drugs (cinoxacin, oxolinic acid, and nalidixic acid) and to trimethoprim-sulfamethoxazole. This study supports recent suggestions that the initial therapy of bacillary dysentery no longer should be ampicillin or tetracycline. It remains for field testing to determine whether quinoline agents or trimethoprim-sulfamethoxazole will be the treatment of choice.

Anti-Bacterial Agents↗
PubMed1976

Sequential changes in the concentration of specific serum proteins during typhoid fever infection in man.

An automated immunoprecipitin system has been utilized to quantitate the concentration of 10 specific proteins in the plasma of man. Values obtained by this technique are in agreement with the published concentrations for these specific plasma proteins. This technique was utilized to determine the sequential change s in 10 individual plasma proteins of volunteers exposed to Salmonella typhi. In those volunteers who developed typical typhoid fever, plasma concentrations of the acute phase proteins, alpha1-acid glycoprotein, alpha1-antitrypsin, and haptoglobin, as well as C3 complement were significantly increased with the onset of febrile illness. In contrast, the concentration of plasma albumin and tranferrin were depressed while plasma IgM became elevated during early convalescence from this infection. No significant changes were observed in the plasma concentrations of alpha2-macroglobulin, IgG, or IgA. In the exposed volunteers who did not become ill, the only significant change was a brief depression of alpha1-antitrypsin. During typhoid fever the patterns of change for individual plasma acute-phase globulins were different from those reported for patients with hepatitis, myocaridal infarction, or surgery.

Adult↗
PubMed1975

Detection of a leukocytic endogenous mediator-like mediator of serum amino acid and zinc depression during various infectious illnesses.

Serum samples from patients with many different kinds of infection were shown to contain a substance characteristic of leukocytic endogenous mediator. Generalized bacterial infections produced more leukocytic endogenous mediator than did localized ones; viral infections produced very little. In typhoid fever, mediator concentrations increased before the onset of illness.

Abscess↗
PubMed1971

Studies of immunity in typhoid fever. Protection induced by killed oral antigens or by primary infection.

Adult male volunteers were orally vaccinated with two "killed" antityphoid preparations. The recommended doses of both vaccines resulted in serum antibody development in only a few of the subjects. When the dose of the monovalent preparation (Taboral) was doubled, serological responses occurred more frequently, with a rise in O agglutinins in nearly one-fifth of the subjects, in H agglutinins in approximately one-fourth, and in Vi antibodies in nearly half.When vaccinated volunteers were fed virulent typhoid organisms, disease occurred less frequently among those men vaccinated with Taboral at twice the recommended dose (38%) than among those not vaccinated (54%). This preparation did not confer protection at the recommended dose.Volunteers who had previously recovered from an induced typhoid infection received a further challenge with virulent organisms. These persons developed typhoid fever less frequently (23%) than individuals without prior typhoid exposure (30%).

Administration, Oral↗
PubMedDate not supplied

Severe weight loss: the predominant clinical presentation of tuberculosis in patients with HIV infection in India.

BACKGROUND: Tuberculosis is endemic in India and its prevalence is reported to be increasing in patients with human immuno-deficiency virus (HIV) infection. Several factors, including the level of immune deficiency, influence the clinical presentation of HIV-associated tuberculosis. METHODS: Between April 1994 and April 1996, 1820 patients with confirmed HIV infection were studied for their clinical, radiological and laboratory parameters. Severe weight loss was observed as a frequent presenting complaint. Hence, a case-control analysis was performed using severe weight loss as the presenting criterion among HIV-seropositive patients. RESULTS: Of the 1820 patients with HIV infection, 410 (23%) presented with severe weight loss of > 10% of body weight within the preceding month. Of these 410 patients, 176 (43%) had tuberculosis, 94 (23%) had chronic diarrhoea, and 89 (22%) had recurrent fever. Among 176 patients with tuberculosis, the following types of HIV-associated tuberculosis were seen: 115/176 (66%) had pulmonary, 49/176 (28%) had extrapulmonary tuberculosis; of these 49 cases with extrapulmonary tuberculosis 33 (18%) had disseminated tuberculosis, and 12/176 (7%) had both pulmonary and extrapulmonary involvement. In the group as a whole, 45/176 (25%) cases had disseminated tuberculosis. Clinical features of HIV-associated tuberculosis in decreasing order of frequency were chronic fever, chronic cough, lymphadenopathy and hepatosplenomegaly. The Mantoux skin test was significantly anergic among patients with extrapulmonary and disseminated tuberculosis (p = 0.001). CONCLUSIONS: There was a significant correlation between severe weight loss and tuberculosis (RR 17.5), chronic diarrhoea (RR 12.8) and recurrent fever (RR 4.5). The diagnostic value of the Mantoux skin test among HIV-associated tuberculosis is reduced, more so among those with extrapulmonary and disseminated forms.

AIDS-Related Opportunistic Infections↗