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Biomedical subjects

S S Morris

Publications and source records attributed to S S Morris.

At least 37 records · Page 2Linked to original sources
PubMed1997

Breast feeding, pacifier use and infant development at 12 months of age: a birth cohort study in Brazil.

Many studies suggest that breast feeding confers developmental and intellectual advantages on children. In a recent study, however, no association was found between breast feeding and intelligence in adult life after adjustment for other variables, and the use of pacifier in infancy was the most important predictor of intelligence. We analysed the associations between breast-feeding duration, pacifier use and suspected developmental delay at 12 months of age in a birth cohort in Pelotas, southern Brazil. All 5304 hospital births occurring during 1993 were studied and a sample was followed up at 1, 3, 6 and 12 months of age. Breast-feeding practices and use of pacifiers were assessed at each visit, as well as suspected developmental delay, measured by the Denver II test. The prevalence of developmental delay was analysed, through logistic regression, according to breast-feeding status and pacifier use, accounting for the possible confounding effect of other variables. The prevalence of suspected developmental delay at 12 months was 34.1%, being slightly higher among children who used pacifiers at 6 months than among non-users (35.3% and 28.7% respectively). There was a marked negative association between breast-feeding duration and developmental delay, with children breast fed for 9 months or more presenting significantly less suspected developmental delay (25.5%) than those breast fed for less than 1 month (42.4%). The effects of multiple variables were tested, and only high parity, smoking during pregnancy, birthweight, gestational age, pacifier use and breast-feeding duration remained significantly associated with suspected developmental delay. The effect of pacifier use, however, disappeared after adjusting for breast-feeding duration, suggesting that breast feeding, and not pacifiers, affects child development.

Age Factors↗
PubMed1997

Postnatal growth patterns of full-term low birth weight infants in Northeast Brazil are related to socioeconomic status.

Low birth weight has many adverse consequences, some of which might be ameliorated if there is good postnatal compensatory, or catch-up, growth. We monitored growth, morbidity and feeding patterns in a cohort of 133 full-term, low birth weight infants from poor families in Pernambuco, Brazil, and investigated the relative contributions of a number of socioeconomic, maternal and infant variables to postnatal growth. Growth was measured at 4, 8, 17, 26 and 52 wk of age. Differential growth patterns were most marked during the first 8 wk of life, and the gains in z-score during this interval were strongly associated with attained z-scores at 12 months (r = 0.62 for weight and 0.64 for length). In a multivariate model, socioeconomic variables explained 21.4% of the variation in maximum gain in weight-for-age z-score achieved during the 12-month period, maternal weight explained a further 4.4%, infant birth length 4.7% and neonatal illness 5.4%. For maximum gain in length-for-age z-score, socioeconomic variables accounted for 24.4% of the variance, maternal height 4.9%, maternal smoking 3.3% and neonatal illness 3.1%. We surmise that the early differential growth patterns are set in utero and are indirectly affected prenatally by socioeconomic status.

Anthropometry↗
PubMed1997

Prevention of diarrhoea in young children in developing countries.

An updated review of nonvaccine interventions for the prevention of childhood diarrhoea in developing countries is presented. The importance of various key preventive strategies (breast-feeding, water supply and sanitation improvements) is confirmed and certain aspects of others (promotion of personal and domestic hygiene, weaning education/food hygiene) are refined. Evidence is also presented to suggest that, subject to cost-effectiveness examination, two other strategies-vitamin A supplementation and the prevention of low birth weight-should be promoted to the first category of interventions, as classified by Feachem, i.e. those which are considered to have high effectiveness and strong feasibility.

Child↗
PubMed1996

Is prevalence of diarrhea a better predictor of subsequent mortality and weight gain than diarrhea incidence?

A number of different outcome measures have been proposed for use in prospective studies of morbidity associated with childhood diarrhea. These include the number of episodes experienced by each child over a defined period (a measure of incidence) and the number of days of diarrhea divided by the total number of days of observation for each child (a measure denoted "longitudinal prevalence"). The authors examined data from Ghana to determine which of these measures is more strongly associated with weight gain over a 4-month period and subsequent mortality. Both diarrhea incidence and longitudinal prevalence were associated with weight gain in children aged 6-23 months, but a statistically stronger association was observed with longitudinal prevalence (likelihood ratio statistic 28.95 on 1 degree of freedom against 19.70 for incidence). Neither measure was associated with weight gain in younger or older children. Longitudinal prevalence, but not incidence, was strongly associated with subsequent mortality (p = 0.002 for longitudinal prevalence; p = 0.557 for incidence). Although many epidemiologic studies of diarrhea focus on incidence, these data suggest that longitudinal prevalence is more strongly predictive of long-term health outcome. The authors conclude that longitudinal prevalence merits greater attention as a measure of outcome in diarrhea studies.

Child, Preschool↗
PubMed1996

Low birth weight and morbidity from diarrhea and respiratory infection in northeast Brazil.

OBJECTIVE: To compare morbidity and mortality rates of low birth weight (LBW) and appropriate birth weight infants born at term, focusing on diarrheal and respiratory infections. STUDY DESIGN: A cohort of 133 LBW infants (1500 to 2499 gm) and 260 appropriate birth weight infants (3000 to 3499 gm), individually matched by sex and season of birth, were followed for the first 6 months of life. None had congenital anomalies and all were from poor families living in the interior of Pernambuco, northeast Brazil. Data on infant deaths, hospitalizations, and morbidity were collected prospectively through daily home visits (except Sundays) from birth through week 8, then twice weekly for weeks 9 to 26. The effects of birth weight were assessed with a variety of multivariable techniques, controlling for confounders. RESULTS: Of the LBW infants, 56% were wasted (thin), 23% were stunted, and 17% were both wasted and stunted. The LBW infants (median 2380 gm) experienced a sevenfold higher mortality rate and fourfold higher rate of hospitalization than appropriate birth weight infants. Almost all deaths and hospitalizations were in the postneonatal period. The LBW infants also experienced 33% more days with diarrhea and 32% more days with vomiting (p = 0.003 in each case). The prevalences of cough and fever were not significantly different. CONCLUSIONS: Infant deaths, hospitalizations, and diarrheal morbidity are increased in term LBW infants who have only a modest weight deficit.

Brazil↗
PubMed1996

Effect of vitamin A supplementation on the growth of young children in northern Ghana.

The effect of prophylactic vitamin A supplementation on child growth was studies in two randomized, placebo-controlled trials carried out in adjacent areas of northern Ghana between 1989 and 1991. In the Health Study, the midupper arm circumference (MUAC) and weight of the approximately 1500 children (aged 6-59 mo) in the trial were measured every 4 wk for up to 52 wk. In addition, MUAC, weight, and height were measured at each of the four potential vitamin A or placebo dosing times, which were at 4-mo intervals. In the Survival Study, MUAC and weight were measured at 4-mo intervals at each of seven dosing rounds in the approximately 15 000 children currently in the trial. Overall, there were > 90 000 observations of weight and MUAC in > 25 000 children, and 3347 observations of length/height in 1546 children. Within each study, the mean monthly weight, MUAC, and gains in length/height in each treatment group were compared by using multilevel modeling. There were no significant differences in either MUAC or gains in length/height. The only significant difference in weight gain was in the Survival Study: children in the vitamin A-supplemented group who were > or = 36 mo of age had a mean weight gain that was 3 g lower per month (95% CI: 0.4, 5.0, P = 0.02) than that in the placebo group; a difference that was unlikely to be functionally important in this age group. Vitamin A supplementation did not lead to any increased growth in this population of young children, in whom supplementation reduced mortality and severe morbidity substantially.

Anthropometry↗
PubMed1996

Abdominal circumference contributes to absence of wasting in Brazilian children.

A number of population groups in Latin America show high prevalences of stunting (low height-for-age) despite very low rates of wasting (weight-for-height deficits). One possible explanation for this phenomenon is an increase in abdominal circumference, which would affect children's weights but not their heights. This study was designed to describe the abdominal circumferences of a group of poor children from Northeast Brazil, and to relate these to their weight-for-weight z-score. Children (n = 252) participating in a government growth monitoring program were studied. The prevalence of stunting (below -2 SD) was 26.2%, but only 1.2% were wasted. Abdominal circumferences increased with age up to 36 mo, followed by a slight decline after 48 mo. Abdominal circumference was the anthropometric measurement most closely associated with weight-for-height, with a coefficient of determination of 41%. Even after adjusting for arm circumference, abdominal circumference continued to explain 16% of the variation in weight-for-height. Despite slight differences in measurement techniques, the study children had consistently larger abdominal girths than a sample of North American children. These findings must be verified by replication but highlight a possible contribution of abdominal circumference in the determination of levels of wasting.

Abdomen↗
PubMed1996

Particulate air pollution and respiratory disease in Anchorage, Alaska.

This paper examines the associations between average daily particulate matter less than 10 microns in diameter (PM10) and temperature with daily outpatient visits for respiratory disease including asthma, bronchitis, and upper respiratory illness in Anchorage, Alaska, where there are few industrial sources of air pollution. In Anchorage, PM10 is composed primarily of earth crustal material and volcanic ash. Carbon monoxide is measured only during the winter months. The number of outpatients visits for respiratory diagnoses during the period 1 May 1992 to 1 March 1994 were derived from medical insurance claims for state and municipal employees and their dependents covered by Aetna insurance. The data were filtered to reduce seasonal trends and serial autocorrelation and adjusted for day of the week. The results show that an increase of 10 micrograms/m3 in PM10 resulted in a 3-6% increase in visits for asthma and a 1-3% increase in visits for upper respiratory diseases. Winter CO concentrations were significantly associated with bronchitis and upper respiratory illness, but not with asthma. Winter CO was highly correlated with automobile exhaust emissions. These findings are consistent with the results of previous studies of particulate pollution in other urban areas and provide evidence that the coarse fraction of PM10 may affect the health of working people.

Air Pollutants↗
PubMed1996

[Nutritional status of pre-school children of the semi-arid region of Bahia (Brazil): II--Vitamin A deficiency].

A survey of 754 preschool children was undertaken in the urban areas of seven small towns of the semi-arid region of Bahia, Northeastern Brazil, to determine the prevalence of vitamin A deficiency, as well as its association with variables such as a age, family income, mother's schooling and dietary adequacy in vitamin A. Protein energy malnutrition and anemia were also studied and are reported separately. The clinical ophthalmological examination did not reveal any signs or symptoms of xerophthalmia amongst these children. In 563 children serum retinol was determined and the average value found was 20.3 micrograms/dl (SD = 10.8 micrograms/dl); the prevalence of deficient serum retinol (below 10.0 micrograms/dl) was of 15.3%. In all 7 localities studied, the prevalence of deficient retinol levels was above 5.0%, the criterion recommended by WHO for considering it a Public Health Problem. The distribution of serum retinol was similar between the sexes, but there was an age trend: the prevalence of deficient and low levels decreased with age. There was no association between deficient serum retinol and family income per capita or mother's education. Results from the 24 h food consumption survey revealed that only 8% of children had an adequate intake of vitamin A through the diet; 66% received less than 1/2 and 35% less than 1/4 of the recommended daily intake of vitamin A. Vitamin A deficiency should be considered a Public Health Problem in the region due to the high prevalence of deficient levels of serum retinol as well as the large dietary inadequacy.

Age Factors↗
PubMed1995

Vitamin A supplementation and childhood malaria in northern Ghana.

Two companion, randomized, placebo-controlled trials of prophylactic vitamin A supplementation provided the opportunity to assess the impact of supplementation on malaria parasitemia, morbidity, and mortality in young children in northern Ghana. In the mortality study, 21,906 children were visited every 4 mo over 2 y, and in the morbidity study 1455 children were visited weekly for 1 y. There was no difference between children supplemented with vitamin A and those given placebo in malaria mortality rates (rate ratio = 1.03; 95% CI 0.74, 1.43) or fever incidence based on reported symptoms. Malaria parasitemia rates, parasite densities in children with a positive blood smear, and rates of probable malaria illness also did not differ between treatment groups. There was no correlation between serum retinol at the beginning of the trial and subsequent malaria parasitemia in children who received placebo (r = 0.01). It is concluded that vitamin A supplementation had no impact on malaria in this population.

Child↗
PubMed1995

Vitamin A supplementation, morbidity, and serum acute-phase proteins in young Ghanaian children.

The association of vitamin A supplementation with concentrations of positive acute-phase proteins in the serum was investigated in the Child Health Study of the Ghana Vitamin A Supplementation Trials, a randomized, controlled trial of the effect of vitamin A on morbidity in children aged < 5 y. Mean serum concentrations of alpha 1-acid glycoprotein, serum amyloid A, and C-reactive protein did not differ overall between the vitamin A-supplemented and placebo-treated groups. Treatment groups were then subdivided according to what symptoms children had experienced in the week before blood sampling. Acute-phase-protein responses to fever and cough were not affected by vitamin A supplementation. There was a tendency for vitamin A-supplemented children, but not placebo children, to have elevated acute-phase proteins in association with reported vomiting or severe diarrhea. The failure of unsupplemented children to mount an acute-phase response may have contributed to their increased morbidity from gastrointestinal symptoms.

Acute-Phase Proteins↗
PubMed1995

[Nutritional and feeding status of preschool children in the semi-arid region of Bahia (Brazil): I. Anthropometric assessment].

A survey of 754 preschool children was undertaken in the urban areas of seven small towns of the semi-arid region of Bahia, Northeast Brazil. The study set out to determine the prevalence of weight and height deficits, as well as to correlate them with variables such as age, family income, mother's schooling and food consumption. A prevalence of 22.9% of Height for Age (HA) below -2.0 SD was found (stunting) and prevalence of 19.1% and 3.6% were determined, respectively for Weight for Age (WA) and Weight for Height (WH) below -2.0 SD (wasting). Regarding food consumption, only 6.8% of the children received a diet with an adequate energy supply for their age group in the previous day. There was a close association between inadequate HA and WA and family income per capita (p = 0.001 and p = 0.000, respectively). Children from families with income < 1/4 of the minimum wage per capita had twice the chance of being malnourished as compared with those from the > or = 1/2 minimum wage per capita stratum. The children included in this study showed prevalences of inadequate WH and WA significantly higher than those found in a national survey conducted in the same period (p = 0.047 and p = 0.000 respectively). This fact is surprising since in the last decade important reductions in child malnutrition and mortality were reported in the country as a whole; this may indicate that children from this region probably were not benefitted in the same way as the rest of the Brazilian child population.

Age Factors↗
PubMed1995

Child morbidity and mortality following vitamin A supplementation in Ghana: time since dosing, number of doses, and time of year.

OBJECTIVES: The impact of large-dose vitamin A supplementation given at intervals of 4 months on child mortality and morbidity was examined according to the time interval since dosing, number of doses received previously, and time of year. METHODS: Two double-blind, randomized, placebo-controlled trials of large doses of vitamin A administered at intervals of 4 months were conducted in adjacent populations in northern Ghana. RESULTS: While vitamin A supplementation significantly reduced the overall incidence of severe illnesses (especially diarrhea with dehydration), clinic attendances, hospital admissions, and mortality, there was no evidence that the impact of each dose of vitamin A was related to the number of doses the child had received previously. There was no evidence that the effectiveness of the supplement waned over the 3 to 5 months between doses. The impact on mortality did not differ significantly by the month in which the supplement had been given. CONCLUSIONS: In the study population, there was no evidence that an interval between doses of less than 4 months would have had a greater impact on severe morbidity or mortality, and the effectiveness of supplementation did not vary by time of year.

Child↗
PubMed1994

Diarrhoea--defining the episode.

BACKGROUND: There is still no consensus on the appropriate definition of an 'episode' of diarrhoea, even though it has been shown that the choice of definition has a major impact on reported incidence rates. Previous work has focused on the observed distribution of illness episodes in time but has not attempted to determine whether the patterns observed depart from those expected by chance. METHODS: A simple theoretical model of the distribution of illness episodes is developed, based on the concept of a 'trigger event'. The model incorporates elements relating to the duration of symptoms, inter-individual variation in incidence rates and seasonality. Appropriate parameters for the model are derived from two empirical datasets. RESULTS: It is shown that short intervals between one aetiologically distinct period of diarrhoea and the next will frequently occur by chance, especially in circumstances where high incidence rates and within-child clustering of illness prevail. The duration of symptoms will have no effect on the length of intervals between periods of illness, and seasonality is unlikely to have a major impact. Over 10% of all non-initial trigger events might be expected to occur during the course of a pre-existing period of diarrhoea, and would not therefore be identified in a study based on reported symptoms. CONCLUSIONS: The findings of previous studies, suggesting that 2 or 3 days without symptoms will generally mark a new episode of diarrhoea, are endorsed. Modelling the expected distribution of illness in time may help to highlight structural or analytical problems with empirical datasets.

Child↗
PubMed1994

Lack of association between vitamin A status and measures of conjunctival epithelial integrity in young children in northern Ghana.

OBJECTIVE: To investigate the association between vitamin A status and conjunctival epithelial function in young children in rural northern Ghana and to consider whether impaired epithelial function was associated with increased measures of systemic infection in these children. DESIGN: Children were selected from the Ghana Vitamin A Supplementation Trials' Child Health Study, a randomized, double-blind, placebo-controlled trial of the effect of vitamin A supplementation on morbidity. Treatment group and serum retinol concentrations were used as measures of vitamin A status, conjunctival impression cytology and tear IgA concentrations as measures of conjunctival epithelial integrity, and serum immunoglobulin and alpha 1-acid glycoprotein concentrations as indicators of chronic or acute systemic infection. SUBJECTS: Children 13-64 months old. INTERVENTION: 60 mg retinol as retinyl palmitate every 4 months for 1 year. RESULTS: Vitamin A status was not significantly associated with epithelial integrity nor with measures of systemic infection. Impaired conjunctival epithelial integrity was also not associated with increased systemic infection. CONCLUSIONS: There was no evidence for a major role of improved epithelial integrity and function on the biochemical indices of chronic or acute systemic infection after vitamin A supplementation. These data support the observations in the main study that vitamin A supplementation did not improve conjunctival impression cytology nor decrease the prevalence of most morbidity symptoms.

Child Nutritional Physiological Phenomena↗
PubMed1993

Influence of morbidity on serum retinol of children in a community-based study in northern Ghana.

Serum retinol concentrations decrease during illness and thus may not accurately reflect the vitamin A status of populations with a high prevalence of illness. To quantify the contribution of illness to low serum retinol in a field study of children aged 6-59 mo in northern Ghana, serum retinol values were compared with two indicators of recent illness; symptoms reported by parents and acute-phase protein concentrations in serum. Serum retinol was not associated with symptoms of illness but showed a significant negative correlation with both alpha 1-acid glycoprotein (AGP) and serum amyloid A (SAA). Elevated AGP was associated with a 24% decrease in mean serum retinol. A large proportion of asymptomatic children had elevated AGP or SAA concentrations, suggesting that subclinical infections may have had important effects on serum retinol. A significant negative correlation between malaria parasite density and serum retinol indicated that malaria may have been one of the subclinical infections responsible. Measurement of AGP may improve interpretation of serum retinol data from populations with a high prevalence of morbidity.

Child, Preschool↗
PubMed1983

Intracellular elemental content of cardiac and skeletal muscle of normal and dystrophic hamsters.

To test the hypothesis that the genetic lesion causing muscular dystrophy might be reflected in an abnormal intracellular elemental content, the elemental content of individual cardiac and skeletal muscle fibers in 50-day-old male control and cardiomyopathic BIO 53.58 hamsters was determined. The technique of electron probe x-ray microanalysis of freeze-dried tissue was employed. No electrolyte content differences were found between control and diseased animals for nuclei, myofibrillar cytoplasm, or mitochondrially-enriched cytoplasm of cardiac myocytes. Sulfur was elevated in dystrophic cardiac myocytes and was the only element significantly different in heart tissue of control and cardiomyopathic animals. Sulfur was also elevated in dystrophic soleus muscle fibers. The pattern of electrolyte content of these cells reflected a mixture of normal cells and damaged cells with altered electrolyte content. In this hamster model, alteration of electrolyte content of myocytes appears to be a result of the disease process and not an inherent characteristic of muscular dystrophy. The elevated sulfur in dystrophic hamster myocytes reflects a biochemical lesion which deserves further study.

Animals↗