Biomedical subjects

D S Robson

Publications and source records attributed to D S Robson.

18 recordsLinked to original sources

PubMed1991

Effect of supplementary feeding on recovery from mild to moderate wasting in preschool children.

Three-month recovery rates from moderate wasting (less than 90% weight-for-length) were compared in 6-24-mo-old children in four Guatemalan villages that had been randomly assigned to receive a moderate (Atole) or low (Fresco) energy supplement. The recovery rate (Rr) in the Atole villages was 12% higher than in the Fresco villages (P less than 0.05). This effect was above all due to the children in the Atole villages who consumed greater than or equal to 10% of the daily recommended dietary intake of energy (RDI) from the supplement (high-Atole group) and whose total energy intake (including home diet) was 10.5% of the RDI higher than a comparable high-Fresco group with low supplemental energy intake. All those in the high-Atole group whose wasting was due to malnutrition recovered. Much of this recovery (range 29-52%) was due to the increased supplementation. This proportion rose after potential confounding variables were controlled for.

Birth Weight↗

PubMed1990

Age-specific responsiveness of weight and length to nutritional supplementation.

Evaluation of the responsiveness of weight and length to supplementary feeding shows that the two periods of greatest response coincide with weaning (ages 3-6 mo) and peak incidence and duration of diarrheal disease (ages 9-12 mo). Analyses were done for seven consecutive nonoverlapping intervals comparing children randomly assigned to receive supplemental feeding from birth to age 36 mo or to serve as control subjects. Absolute responsiveness was greatest between ages 3-6 mo; supplemented infants grew 0.61 cm more and gained 162 g more than did unsupplemented infants (p less than 0.005). Relative to rates of growth, responsiveness was greatest between ages 9 and 12 mo (the period of peak diarrheal prevalence), followed by ages 3-6 mo (the period of weaning). Responsiveness to supplementation is thus directly related to age-dependent risk patterns for malnutrition. Targeting supplementation programs to coincide with periods of high nutritional risk should maximize their effectiveness in reducing malnutrition, though caution should be exercised to avoid disruption of breast-feeding.

Age Factors↗

PubMed1989

Nutritional supplementation: effects on child stunting because of diarrhea.

Research has shown that the positive effect of nutritional supplementation on child growth in malnourished populations is small relative to the large negative effect of diarrheal disease. To test the hypothesis that the effects of supplementation and diarrhea are synergistic in that supplementation modifies the negative effect of diarrhea on linear growth, length and diarrheal morbidity were compared at 36 mo of age for two cohorts of Colombian children: supplemented from birth and unsupplemented. Among unsupplemented children diarrhea was negatively associated with length. Among supplemented children diarrhea had no effect on length and differed from that of unsupplemented children. Thus, supplementation completely offset the negative effect of diarrheal disease on length. Targeting supplementation programs to the critical period of high diarrheal prevalence among infants and young children should increase the effectiveness of such programs in preventing growth retardation associated with diarrhea.

Child Nutritional Physiological Phenomena↗

PubMed1985

In vitro protective effect of bacteria-derived bovine alpha interferon I1 against selected bovine viruses.

We used bacteria-derived bovine alpha-interferon I1 (Bo IFN-alpha I1) to study its antiviral effect in a bovine turbinate cell line on bovine diarrhea virus, infectious bovine rhinotracheitis virus, parainfluenza 3 virus, and pseudorabies virus. We based our study upon replicate tests for each strain by using a block titration system with various concentrations of Bo IFN-alpha I1 against various concentrations of virus. The data were compiled in two-axis tables (replicate X concentration) and were statistically analyzed by the Spearman-Kärber method. An increase in the concentration of Bo IFN-alpha I1 enhanced its protective effect against every test virus strain. Bo IFN-alpha I1 had a marked in vitro effect on the bovine diarrhea viral strains. It demonstrated less protection against the pseudorabies and parainfluenza 3 viruses. Its effectiveness against the two infectious bovine rhinotracheitis viral strains was lesser and of a low order.

Animals↗

PubMed1976

Models allowing for age-dependent survival rates for band-return data.

Seber [1970] and Robson and Youngs [1971] developed a statistical model for a tag-recapture experiment on an exploited animal population in which banded or tagged individuals are released into a population each year, and the bands from harvested individuals are returned by hunters or fishermen in following years. Consideration of certain biological and ecologicw models for an experimental situation where data are recorded separately for birds released as adults and as young-of-the-year. In particular, the effect of different survival rates of young birds, and the effect of migration on reporting rates, are taken into account in the models presented in this study. Maximum likelihood estimators of parameters are derived under the different models, and procedures are developed to discriminate between alternative models as well as provide non-discriminant goodness-of-fit tests.

Age Factors↗

PubMed1976

Analysis of the microfilarial periodicity of Dirofilaria immitis.

Microfilarial periodicity displayed by dogs infected with Dirofilaria immitis was analyzed using the methematical model proposed by Sasa and Tanaka (S.E. Asian J. Trop. Med. and Pub. Health 4, 1974, 518-536) except that Pearson's product-moment correlation test was substituted for their Chi-square analysis to estimate goodness of fit. Samples were drawn at 3 hour intervals for periods of 24 or 48 hours in a series of 10 studies conducted on 4 dogs. No significant differences were observed in microfilarial concentration between samples of venous and cutaneous capillary blood. Significant correlation of observed microfilarial densities with the values predicted by the model were observed in 7 of the 10 studies with r2 values ranging from 78.8 to 95.3%. The periodicity index ranged from 28.33 to 53.50 in these 7 studies and thus fell in the subperiodic category. The estimated hour of peak microfilarial density was not confined to the late afternoon as generally believed; for example, values of 04:00 and 22:00 hours were observed. Thus D. immitis microfilaremia cannot accurately be characterized either as diurnal or as nocturnal. Observation of the behavior of the experimental dogs led to an hypothesis that emotional and environmental stresses placed on the host may induce transients in the microfilarial density that may overwhelm or obscure the periodicity function.

Animals↗

PubMed1975

Canine adenovirus type 2-induced immunity to two canine adenoviruses in pups with maternal antibody.

Twenty-four Beagle pups with high levels of maternal antibody to canine adenovirus type 1 (CAV-1) and canine adenovirus type 2 (CAV-2) were oronasally inoculated with CAV-2 at 4 weeks of age. The CAV-2 was isolated from pharyngeal swabs on postinoculation days 2 through 6. In spite of the infection, maternal antibody continued to decrease for 4 to 8 postinoculation weeks, and then homologous CAV-2 neutralizing antibody and, to a lesser extent, CAV-1 neutralizing antibody began to increase. When these pups were challenge inoculated with CAV-1 and CAV-2 at a time when maternal antibody to CAV-1 would normally have disappeared, they were immune. In addition, 3 pups with maternal antibody to CAV-1 and CAV-2 were intramuscularly inoculated with CAV-2 at 3 weeks of age. Virus was not isolated from these pups, and maternal antibody decreased at a normal rate. These pups were not immune to challenge inoculation with CAV-1 and CAV-2.

Adenoviridae↗

PubMed1974