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Biomedical subjects

M Santosham

Publications and source records attributed to M Santosham.

At least 91 records · Page 5Linked to original sources

Prevention of Haemophilus influenzae type b infections in high-risk infants treated with bacterial polysaccharide immune globulin.

Apache Indian infants have a high frequency of Haemophilus influenzae type b (Hib) and pneumococcal infections. Forty percent of Hib infections in these infants occur before the age of six months, when active immunization may not be protective. To evaluate the efficacy of passive immunization with a human hyperimmune globulin (bacterial polysaccharide immune globulin [BPIG]) prepared from the plasma of immunized adult donors, we randomly assigned 703 infants in a double-blind fashion to receive 0.5 ml of BPIG per kilogram of body weight (n = 353) or 0.5 ml of saline (n = 350) intramuscularly at 2, 6, and 10 months of age. Hib-antibody levels were significantly higher in BPIG recipients than in placebo recipients at 4, 6, and 10 months of age (P less than 0.001). During the first 90 days after BPIG or placebo injection, no Hib or pneumococcal infections were detected in the BPIG group, whereas seven Hib infections (six cases of bacteremia and one of meningitis) and four pneumococcal infections (bacteremia) were detected in the placebo group (P = 0.007 and 0.06, respectively). During the fourth month, one case of Hib meningitis and two cases of pneumococcal bacteremia developed in the BPIG group, whereas there were no Hib or pneumococcal infections in the placebo group. We conclude that BPIG given at four-month intervals provided significant protection against serious Hib disease for three months, and that in high-risk infants it might be used alone, perhaps at three-month intervals, or together with active immunization.

Antibodies, Bacterial↗

Glycine-based oral rehydration solution: reassessment of safety and efficacy.

We evaluated the safety and efficacy of a glycine-based orally administered rehydration solution by comparing it with a standard oral rehydration solution (ORS) without glycine in a randomized double-blind trial in United States infants (age less than 15 months) given treatment for acute gastroenteritis as inpatients or outpatients. The response to therapy (stool volume and duration of illness) was similar in the two groups, except that in four (13%) of 31 hospitalized infants receiving glycine-ORS hypernatremia developed, (one had symptoms) compared with none of 35 receiving ORS (P less than 0.04). Among the 77 outpatients there were no differences between the groups. This study demonstrates that glycine-ORS did not provide any therapeutic advantage over standard ORS, and hypernatremia developed in some patients receiving glycine-ORS. We suggest that caution be used with this type of solution until further safety studies have been done.

Anti-Bacterial Agents↗

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↗

Epidemiology of rotavirus diarrhea in a prospectively monitored American Indian population.

Rotaviral diarrhea is endemic in most areas of the world, yet community-wide epidemics have not been reported in prospectively monitored populations. This prospective study of the etiology of diarrhea included biweekly visits to the homes of 10% of the population of the White Mountain Apache Indians and began in April 1981. During a three-week period beginning 21 October, 1981, 342 new cases of diarrhea were identified on different parts of the reservation. Rotaviral antigen, detected by an enzyme-linked immunosorbent assay, was identified in 169 (73%) of the 233 stool samples that were tested. Rotavirus was not detected in any of the stool samples taken six months before or after the epidemic. During the epidemic, respiratory symptoms were present in 44 (33%) of 135 rotavirus-positive patients compared with 17 (17%) of 98 rotavirus-negative patients (P less than .05). This rapidly spreading epidemic involving all areas of the reservation, in the absence of a common source of exposure of ill persons, suggests the possibility of respiratory transmission.

Adolescent↗

Oral rehydration therapy for acute diarrhea in ambulatory children in the United States: a double-blind comparison of four different solutions.

Oral rehydration solutions containing 50 to 90 mmol/L of sodium have recently been recommended for the treatment of diarrhea in both hospitalized and ambulatory children in the United States. Few data are available, however, from ambulatory US children. Therefore, we conducted a randomized double-blind study comparing the use of four different oral rehydration solutions with differing concentrations of sodium, glucose, and base. Ambulatory children less than 2 years of age with acute diarrhea (N = 140) were randomly chosen to receive solutions containing sodium at 90 (solution A), 50 (solution B), and 30 mmol/L (solutions C and D). All oral rehydration solutions contained 20 g/L of glucose except solution D which contained 50 g/L of glucose. Solution A contained bicarbonate as its base source whereas the other three contained citrate. All but three (98%) children were treated uneventfully according to the study protocol, and there were no differences among groups in measurements of clinical outcome. It was concluded that in ambulatory US children, oral rehydration solutions containing 90, 50, or 30 mmol/L of sodium can be used safely for the treatment of mild acute diarrhea and that citrate is as efficacious as bicarbonate in the correction of acidosis.

Ambulatory Care↗

Role of soy-based, lactose-free formula during treatment of acute diarrhea.

A controlled study was conducted comparing the standard method of treating hospitalized infants with acute diarrhea (limited starvation) with the initiation of "early feeding" using a soy-based, lactose-free formula in infants of an American Indian tribe 12 months of age or younger. Forty-three patients, randomly assigned to group A, were given a soy-based, lactose-free formula four hours after hospitalization, and 44 patients, randomly assigned to group B, received standard therapy (food was withheld for the first 48 hours of hospitalization). After the first 48 hours, the same soy-based, lactose-free formula was given to the group B patients. Fluid intake and output of stool, urine, and vomitus were measured until the diarrhea resolved. Overall, group A patients showed less mean stool output (121 +/- 129 (SD) mL/kg) than group B patients (299 +/- 319 mL/kg) (P less than .001). Furthermore, the duration of illness was significantly shorter in group A patients (54 +/- 28 hours v 93 +/- 56 hours) (P less than .001). It was concluded that soy-based, lactose-free formulas can be safely used during the acute phase of diarrheal illness in infants and that their use shortens the duration of illness and decreases stool output in comparison with standard therapy.

Combined Modality Therapy↗

Outpatient use of oral rehydration solutions in Apache population: effect of instructions on preparation and contamination.

Oral Rehydration Solutions (ORS) containing 90 and 50 mmol/L sodium have recently been recommended for use in ambulatory children in the U.S. These solutions are now marketed in powder form by some commercial companies. However, few data are available in the U.S. on the accuracy with which the solutions are mixed at home or on the bacterial contamination that may occur during mixing. We evaluated the effect of various forms of instructions on the occurrence of bacterial contamination and accuracy of mixing ORS at home by mothers of patients who were dispensed the dry ingredients of an ORS containing 90 mmol/L sodium at the U.S. Public Health Service Hospital, Whiteriver, Arizona. Patients were randomized to one of the four following groups: group I (23 patients) was given written instructions for mixing the solution along with a pre-marked container; group II (22 patients) was given written instructions only; group III (22 patients) was given a premarked container only; and group IV (19 patients) was given neither. All patients were given oral instructions in the preparation of ORS and were asked to refrigerate the reconstituted ORS. We collected samples of ORS at the patient's home 1 day after the clinic visit, to measure their electrolyte content and to identify any bacterial contamination. Mean Na+ concentrations were significantly lower in the ORS prepared by mothers/guardians in groups that were not given a premarked container [82 +/- 13 (II) and 79 +/- 21 (IV) mmol/L vs. 88 +/- 13 (I) and 92 +/- 14 (III) mmol/L; p less than 0.01].(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Oral↗

Doxycycline prophylaxis of travelers' diarrhea in Honduras, an area where resistance to doxycycline is common among enterotoxigenic Escherichia coli.

Daily doxycycline (DX), known to be effective prophylaxis against travelers' diarrhea (TD) in areas of the world where enterotoxigenic Escherichia coli (ETEC) are sensitive to the drug, has not been extensively studied in geographic areas where antibiotic resistance is common. Therefore we studied 44 U.S. Peace Corps Volunteers during their first 5 weeks in Honduras, which is such an area. During the first 3 weeks, volunteers took daily either 100 mg DX or placebo (PL) in a double-blind, randomized fashion. All 22 taking PL developed TD during the first 3 weeks, compared to 7 of 22 (32%) taking DX (P less than 0.001; 68% protection). ETEC were isolated from 39% of episodes of TD. From the PL group, ETEC from 7 of 13 stool samples (54%) were resistant to DX, whereas from the DX group, ETEC from 10 of 11 stool samples were resistant (P less than 0.05). TD that developed in persons taking DX was also found to be less severe, as judged by length of illness (P less than 0.01) and frequency of stools (P less than 0.05). This study demonstrates that DX 1) significantly prevents TD even in areas where antibiotic resistance is common, although it does not prevent TD caused by docycycline -resistant ETEC, and 2) significantly diminishes the severity of illness.

Adult↗

Enzyme immunoassays for the detection of bacterial antigens utilizing biotin-labeled antibody and peroxidase biotin--avidin complex.

This report describes the use of biotin-labeled antibodies in sensitive enzyme immunoassay systems for the measurement of bacterial antigens. Biotinylated immunoglobulins could be reproducibly formulated using N-hydroxysuccinimide biotin ester to link biotin to the immunoglobulin. Binding of the biotinylated antibody to solid-phase antigen was efficiently measured by reaction with a complex consisting of biotinylated antibody and unlabeled avidin. This immunoassay system was at least as sensitive as ones which utilized enzyme-labeled or fluorescein-labeled antibodies for the detection of antigens from Streptococcus pneumoniae and Haemophilus influenzae type b. In the case of Streptococcus pneumoniae the assay system could detect antigen in the supernatants from broth cultures containing as few as 10(3) organisms/ml. Assay systems utilizing biotinylated antibody and avidin-biotin complex can provide for sensitive, specific assays for the measurement of microbial antigens.

Animals↗

Rotavirus-associated traveler's diarrhea: neutralizing antibody in asymptomatic infections.

The sera of patients with traveler's diarrhea were assayed for rotavirus-specific immunoglobulins in enzyme-linked immunosorbent and micro-neutralization assays. The antigenically related simian rotavirus SA-11 was used in both assays. Although similar titers of rotavirus-specific binding immunoglobulin G and A were observed in the sera of both symptomatic and asymptomatic subjects, clinical illness appeared to correlate with the failure to detect increased (greater than or equal to fourfold) titers of neutralizing antibodies in the post- as compared with the pretravel sera.

Antibodies, Viral↗

Oral rehydration therapy in well-nourished ambulatory children.

Oral rehydration solutions (ORS) containing 90 mmol/liter or 50 mmol/liter of sodium have been successfully used in the treatment of hospitalized well-nourished and undernourished children; however, few data are available on the use of these ORS in well-nourished ambulatory children with minimal dehydration. We therefore compared the safety and efficacy of both ORS with standard outpatient management in a controlled, randomized study among 93 well-nourished children aged 3 months to 2 years, with minimal dehydration secondary to acute diarrhea at an outpatient clinic in Panama. Patients in all three groups were hydrated successfully. However, patients in both ORS groups gained significantly (P less than 0.05) more weight at the 2-week follow-up compared to the control group. There were no complications due to the use of either ORS. No child developed hypernatremia nor hyponatremia during therapy. These studies indicate that both ORS (containing 90 or 50 mmol/liter of sodium) are effective and safe in hydrating well-nourished ambulatory children with minimal dehydration.

Ambulatory Care↗