Formulation Controls the Potential Neuromuscular Toxicity of Polyethylene Photoproducts in Developing Zebrafish

Sunlight transforms plastic into water-soluble products, the potential toxicity of which remains unresolved, particularly for vertebrate animals. We evaluated acute toxicity and gene expression in developing zebrafish larvae after 5 days of exposure to photoproduced (P) and dark (D) leachates from additive-free polyethylene (PE) film and consumer-grade, additive-containing, conventional, and recycled PE bags. Using a "worst-case" scenario, with plastic concentrations exceeding those found in natural waters, we observed no acute toxicity. However, at the molecular level, RNA sequencing revealed differences in the number of differentially expressed genes (DEGs) for each leachate treatment: thousands of genes (5442 P, 577 D) for the additive-free film, tens of genes for the additive-containing conventional bag (14 P, 7 D), and none for the additive-containing recycled bag. Gene ontology enrichment analyses suggested that the additive-free PE leachates disrupted neuromuscular processes via biophysical signaling; this was most pronounced for the photoproduced leachates. We suggest that the fewer DEGs elicited by the leachates from conventional PE bags (and none from recycled bags) could be due to differences in photoproduced leachate composition caused by titanium dioxide-catalyzed reactions not present in the additive-free PE. This work demonstrates that the potential toxicity of plastic photoproducts can be product formulation-specific.

Sex differences in under and over nutrition among school-going Black teenagers in South Africa: an uneven nutrition trajectory

OBJECTIVES

To investigate the nutritional status of Black South African teenagers by sex and compare it with nutritional profiles of teenagers from other countries.

METHODS

The first South African Youth Risk Behaviour Survey (2002) was adapted to include anthropometric data and this paper reports on the prevalence of under and over nutrition among 5322 Black teenagers, aged 13.0-17.9 years, grades 8-11. Prevalence of over nutrition in this study was compared with other countries using a World Bank country economic classification.

RESULTS

Significant sex differences were observed for under and over nutrition. Boys (18.4%) had a higher prevalence of underweight than girls (2.6%) (P < 0.005), who were more at risk of overweight than boys (20.9%vs. 4.2%) (P < 0.005). Boys (21.9%) were more stunted than girls (9.4%) (P < 0.05), but stunted girls were at greater risk of overweight than boys across all levels of stunting. The prevalence of overweight among boys (4.2%) was lower than in other countries while for girls (20.9%) was similar to several upper middle and high income countries.

CONCLUSION

Gender sensitive strategies are required to address both under and over nutrition among South African teenagers to reduce stunting and future chronic disease epidemics in adulthood. This paper suggests that Black South African teenagers are experiencing an uneven nutritional transition across sex, from under nutrition to over nutrition.

Investigating the mental abilities of rural Zulu primary school children in South Africa

INTRODUCTION

Maximising the full potential of health and educational interventions in South African schools requires assessment of the current level of mental abilities of the school children as measured by cognitive and scholastic tests and the identification of any barriers to improved performance.

OBJECTIVES

This study reports on the application and interpretation of a selected battery of mental ability tests among Zulu school children and the methodological and analytical issues that need to be addressed.

DESIGN

The test scores of 806 primary school children from a rural community are presented, based on four tests: Raven's Coloured Progressive Matrices (CPM), an Auditory Verbal Learning Test (AVLT), the Symbol Digit Modalities Test (SDMT) and Young's Group Mathematics Test (GMT).

RESULTS

Significant gender differences were found in the test scores, and the mean scores of Zulu children in this study were lower than those reported in other studies. The results of this selected test battery provide data for the further development of appropriate test instruments for South African conditions.

CONCLUSION

These results can contribute towards the development of a test battery for South African children that can be used to assess and improve their school performance.

Implications of the prevalence of stunting, overweight and obesity amongst South African primary school children: a possible nutritional transition?

OBJECTIVE

To investigate the relationship between stunting and levels of overweight/obesity among South African school children, using two definitions of overweight and obesity, based on the WHO and International Obesity Task Force (IOTF) criteria.

DESIGN

Cross-sectional descriptive analysis of the nutritional status of primary school children, using primary data from a rural community-based study undertaken in 1995 and secondary data from the South African National Primary Schools (SANPS) survey conducted in 1994. Stunting was measured according to the WHO definition of -2 Z scores height-for-age. Two sets of criteria were used to measure overweight and obesity-the WHO/NCHS standard based on the 85th and 95th centiles and the IOTF criteria.

SETTING

The primary data source was from a rural KwaZulu-Natal community based survey. The secondary data source SANPS consisted of data at National and Provincial level; for this study only data from the province of KwaZulu-Natal was considered.

SUBJECTS

Primary school children aged between 8 and 11 y of age; 802 from the primary data source and 24 391 from the secondary source.

RESULTS

Moderate stunting ranged from 2.9 to 40.2%, and mild stunting ranged from 31.4 to 75%. The prevalence of overweight ranged from 0.4 to 13.3% (WHO criteria) and from 0.4 to 11.9% using the IOTF criteria; while obesity ranged from 0.1 to 3.7% (WHO) and from 0.1 to 1.5% (IOTF criteria). The prevalence of overweight and obesity was observed to be higher using the WHO definition than that of IOTF (0.05<P<0.10). However, good kappa coefficient (kappa) levels of agreement were observed between the WHO and IOTF definitions of overweight and obesity (kappa>0.55, in all cases). The levels of agreement in all cases were less for obesity than overweight (both ranged from 0.55 to 1.0). Females were observed to have higher kappa levels than their male counterparts; they also had higher prevalence levels of overweight and obesity across age and geographical group. Uniformly high levels of both mild and moderate stunting were observed both nationally and provincially. However, no excess relative risk of being overweight if stunted was observed in this study (P>0.05).

CONCLUSIONS

Caution must be applied when using either definition for obesity. However, very high levels of agreement occur for overweight. There is no obvious relationship between overweight and stunting in this study, but high levels of mild stunting were observed. Regular clinical and epidemiological monitoring of nutritional status needs to be undertaken in South Africa to examine possible future trends of overweight/obesity and their relationship with stunting, and for comparisons with global trends.

Epidemiology of helminth infections: implications for parasite control programmes, a South African perspective

OBJECTIVES

To determine the epidemiology of helminthic infections and the efficacy of parasite treatment among rural South African primary school children in the province of KwaZulu-Natal. To assess the South African government's parasite control policy.

METHODS

The study recruited 268 school children, aged 8 to 10, and randomly allocated them into treatment and placebo groups (treatment consisted of a single dose of albendazole (400 mg) and praziquantel (40 mg/kg)). Anthropometric measurements and the prevalence and intensity of helminth infections were taken at baseline (prior to treatment) and 16 weeks post treatment. Two weeks after treatment prevalence and intensity were again measured for an approximate 50% sub-sample of the children to investigate efficacy of treatment. An analysis of the South African government's policies concerning parasite control is assessed in the light of these epidemiological findings.

RESULTS

Low levels of both stunting and wasting were observed throughout the study (approximately 10% and 1%, respectively), but did not vary significantly across either treatment group or time period (P >0.50). At baseline the observed prevalences for the three main helminths found in this study among the treated children were Ascaris lumbricoides 29.5%, Trichuris trichiura 51.9% and Schistosoma haematobium 22.3%. These prevalences declined significantly to 4.7% (P <0.0005), 38.0% (P < 0.03), and 3.3% (P < 0.0002), respectively, 16 weeks post treatment. The majority of infections observed at baseline were of light intensity, namely A. lumbricoides (50%), T. trichiura (80%) and S. haematobium (100%), and following treatment these levels were reduced significantly (P <0.0001, P< 0.05 and P < 0.005, respectively). The levels of both prevalence and intensity in the untreated group remained constant. The cure rates over the first two weeks of the study were found to be 94.4% for A. lumbricoides, 40% for T. trichiura and 72.2% for S. haematobium.

CONCLUSION

The benefits of targeted, school-based treatment in reducing the prevalence and intensity of infection supports the South African government's focus of using school-based interventions as part of an integrated parasite control programme. These strategies and programmes are consistent with recommendations of the World Health Organization (WHO) and The United Nations Children's Fund (UNICEF).

A randomized controlled trial of the effect of antihelminthic treatment and micronutrient fortification on health status and school performance of rural primary school children

Single interventions for helminthic infections and micronutrient deficiencies are effective, but it is not clear whether combined interventions will provide equal, additive or synergistic effects to improve children's health. The study objective was to determine the impact of single and combined interventions on nutritional status and scholastic and cognitive performance of school children. A double-blind, randomized, placebo-controlled trial in 11 rural South African primary school randomly allocated 579 children aged between 8 and 10 years into six study groups, half of whom received antihelminthic treatment at baseline. The de-wormed and non-de-wormed arms were further divided into three groups and given biscuits, either unfortified or fortified with vitamin A and iron or with vitamin A only, given daily for 16 weeks. The outcome measures were anthropometric, micronutrient and parasite status, and scholastic and cognitive test scores. There was a significant treatment effect of vitamin A on serum retinol (p < 0.01), and the suggestion of an additive effect between vitamin A fortification and de-worming. Fortified biscuits improved micronutrient status in rural primary school children; vitamin A with de-worming had a greater impact on micronutrient status than vitamin A fortification alone and antihelminthic treatment significantly reduced the overall prevalence of parasite infection. The burden of micronutrient deficiency (anaemia, iron and vitamin A) and stunting in this study population was low and, coupled with the restricted duration of the intervention (16 weeks), might have limited the impact of the interventions.

Active management of the third stage at caesarean section: a randomised controlled trial of misoprostol versus syntocinon

The objective of this trial was to investigate whether 500 microg oral misoprostol given immediately after delivery of the neonate at Caesarean section is as effective as a bolus intravenous injection of 10 iu Syntocinon in stimulating uterine contractions and thereby reducing blood loss. Forty women undergoing elective or emergency Caesarean section were included in a placebo-controlled randomised trial. Group 1 received oral misoprostol and a placebo intravenous bolus and Group 2 received intravenous Syntocinon and oral placebo tablets. The main outcome measures were estimated blood loss at Caesarean section, drop in serum haemoglobin, and the need for additional uterotonic agents. We found that there was no significant difference (p = 0.75) in estimated blood loss between the two groups. No differences were observed in the decrease in haemoglobin, requirement for additional oxytocics, the need for blood transfusion or the degree of shivering in each group (p > 0.05 in each case). We concluded that oral misoprostol could be used as an alternative oxytocic agent for the third stage at Caesarean section. However, there is an obvious need for a larger randomised controlled trial to be undertaken. Previous published studies have concentrated on vaginal births and further studies should be extended to Caesarean deliveries.

A randomized study comparing rectally administered misoprostol versus Syntometrine combined with an oxytocin infusion for the cessation of primary post partum hemorrhage

BACKGROUND

Post partum hemorrhage is a major cause of maternal death, particularly in developing countries, and most cases are due to an atonic uterus. Hemorrhage can occur despite active management of the third stage of labor. Presently, misoprostol (Cytotec, Searle Pharmaceuticals) is the only thermostable uterotonic agent potentially available which would be economically beneficial for developing countries where refrigeration of drugs poses a problem. The objective of the study was to compare intra-muscular Syntometrine (Sandoz Pharmaceuticals) (ampoule=5 iu oxytocin and 500 mcg ergometrine maleate) plus Syntocinon (Sandoz Pharmceuticals) (10 iu oxytocin diluted in 500 ml normal saline) intravenous infusion versus 800 mcg misoprostol per rectum for treatment of primary post partum hemorrhage in a developing country.

METHODS

Randomized single blinded two-center study, set in both a township and teaching hospital in South Africa. Sixty-four women with primary post partum hemorrhage due to an atonic uterus were recruited. The primary outcome measure was whether the hemorrhage ceased within 20 minutes of administering the first line treatment, once hemorrhage was clinically recognized.

RESULTS

There was a 28.1% difference between the misoprostol arm and the Syntometrine and Syntocinon arm (p=0.01). This result had a greater than 80% power. Misoprostol performed better.

CONCLUSION

800 mcg misoprostol per rectum is effective at treating primary post partum hemorrhage.

The effect of antenatal vitamin A and beta-carotene supplementation on gut integrity of infants of HIV-infected South African women

BACKGROUND

Vitamin A is important for protection against diarrhea, and supplements may benefit gut function of infants of HIV-infected mothers.

METHODS

We studied 238 infants of HIV-infected South African women participating in a randomized, double-blind, placebo-controlled trial of vitamin A during pregnancy (1.5 mg retinyl palmitate and 30 mg beta-carotene daily) plus 60 mg retinyl palmitate at delivery. The placebo group received identical placebo capsules at the same times. When infants were 1, 6, and 14 weeks of age, lactulose/mannitol dual sugar intestinal permeability tests were performed.

RESULTS

Maternal vitamin A supplementation did not significantly affect infant gut permeability in the group as a whole at any time. By multiple regression analysis, HIV infection of the infant by 14 weeks was significantly associated with increased gut permeability at both 6 and 14 weeks. After controlling for birth weight, gestational age, current weight, feeding mode and recent morbidity, there was a trend toward an interaction between vitamin A supplementation and HIV infection (P = 0.086) at 14 weeks. Vitamin A made no difference to gut permeability of uninfected infants (lactulose/mannitol ratio for vitamin A group: 0.11, 95% confidence interval [CI] 0.08, 0.15, n = 73 and for placebo group: 0.09, 95% CI 0.06, 0.12, n = 76), but largely prevented the increase in the ratio of HIV-infected infants (vitamin A group: 0.17, 95% CI 0.13, 0.23, n = 23; placebo group: 0.50, 95% CI 0.37, 0.68, n = 20). The effects on the lactulose/mannitol ratio were related to changes in lactulose, not mannitol, excretion. Vitamin A supplementation was associated with significantly lower lactulose excretion at 1 and 14 weeks, suggesting the major effect of vitamin A was on maintaining the integrity of gut tight junctions.

CONCLUSIONS

Vitamin A supplementation of HIV-infected pregnant women may prevent the deterioration in gut integrity in the subgroup of their infants who themselves become infected. Improving vitamin A status of HIV-infected infants may decrease their gastrointestinal morbidity.

A health and nutritional profile of rural school children in KwaZulu-Natal, South Africa

A community-based cross-sectional study was undertaken to measure anthropometric indices, micronutrient status and prevalence of parasite infections in 579 rural South African primary school children. Eleven schools were selected randomly from a Magisterial District in southern KwaZulu-Natal (KZN). In each school, all pupils aged between 8 and 10 years were selected. The following outcome measures were obtained: anthropometric--height for age, weight for age and body mass index; micronutrient status--anaemia, serum ferritin and vitamin A; and prevalence of parasite infections--Ascaris lumbricoides, Trichuris trichiura and Schistosoma haematobium. The observed prevalences were: stunting 7.3%, underweight for age 0.7%, and obesity 3.1%; anaemia 16.5% (Hb < 12 g/dl), vitamin A deficiency 34.7% (serum retinol < 20 micrograms/dl) and 28.1% with reduced serum ferritin (< 12 ng/ml); Trichuris trichiura 53.9%, Ascaris lumbricoides 27.3% and Schistosoma haematobium 24.5%. We conclude that micronutrient deficiency, parasitic infestations and stunting remain significant problems among school-aged children in South Africa. Micronutrient supplementation and de-worming provide opportunities for school-based health promotion and primary health care interventions, and might produce significant health and educational benefits.

Incremental analysis of diagnostic peritoneal lavage fluid in adult abdominal trauma

It is uncertain how much diagnostic peritoneal lavage (DPL) fluid must be recovered from abdominal trauma patients to avoid falsely low red blood cell (RBC) counts. A study was carried out to investigate this controversy. A convenience sample of adult abdominal trauma patients in a Level 1 university trauma center who were undergoing DPL with 1 L crystalloid was enrolled. Subjects with grossly positive or colorless effluent were excluded. A blinded prospective experimental design was used. Differences were evaluated among RBC counts collected at 200, 400, 600, and 800 mL of returned fluid using repeated-measures analysis of variance. In 11 patients, mean RBC counts collected at 200 and 400 mL were 24,600 (95% confidence interval [CI], 20,700 to 29,100) and 39,700 (95% CI, 33,200 to 47,100) cells/microL. These were substantially lower than the final mean count of 95,800 (95% CI, 80,000 to 115,800), measured at 800 mL (F = 23.7, P < .0001). Mean counts at 600 mL were less than those obtained at 800 mL but were not statistically different (P = .08). Two of the 11 subjects would have been misclassified (as not requiring surgery) had "early" sampling been used. In abdominal trauma patients, the RBC count of DPL fluid regularly increases as more fluid is recovered. It is important to collect >600 mL of effluent to avoid misleading, low RBC counts and misclassification of patients.

Dietary management of acute diarrhoea in children: effect of fermented and amylase-digested weaning foods on intestinal permeability

BACKGROUND

There is a strong relationship between diarrhoea, malnutrition, and intestinal integrity. To investigate the effect of different dietary-treatment on intestinal permeability during acute diarrhoea, 87 Tanzanian children aged 6-25 months were recruited to this study when admitted to hospital.

METHODS

Children with acute diarrhoea were rehydrated and then randomly assigned to one of three dietary treatment groups: a conventional low-energy density porridge, a high-energy density amylase digested porridge (AMD), or a high-energy density amylase digested and then fermented porridge (FAD). Lactulose/mannitol permeability tests were performed on admission, at 3 days, and at follow-up 2 and 4 weeks after discharge. The lactulose/mannitol (L/M) ratios were compared between dietary treatment groups and to a group of age-matched, healthy control subjects.

RESULTS

Children with diarrhoea had higher L/M ratios (geometric mean 0.85, 95% CI 0.68-1.05) compared with control subjects (0.14, 0.12-0.17) on admission. There was a significant difference in the change in L/M ratio between admission and 3 days between dietary treatment groups in favour of the FAD group (p < 0.05).

CONCLUSIONS

Dietary treatment and intestinal damage at admission explain 13.5% of the variation in L/M ratio, but when age at admission and age at weaning are included as covariants, 21.9% is explained. FAD porridge seems to be more effective in the treatment of intestinal permeability than AMD or conventional porridge. Urinary lactose concentrations in spot urine samples taken prior to the permeability test were also measured. There was a significant correlation with the L/M ratio (correlation coefficient = 0.62, p < 0.001).

Improved energy intakes using amylase-digested weaning foods in Tanzanian children with acute diarrhea

Amylase from germinating cereal grains enables the preparation of porridge with a higher energy density than conventional weaning foods. This food can be combined with fermentation, which inhibits pathogen growth. These food technologies are inexpensive, can be implemented at the household level, and are therefore particularly appropriate for use in developing countries. In a controlled clinical trial, 75 children aged 6-25 months admitted to hospital with acute diarrhea were rehydrated and then randomly allocated to three corn porridge dietary groups: conventional, amylase-digested (AMD), and fermented and amylase-digested (FAD). The study diets were given ad libitum five times daily, and all intakes except breast milk were weighed. Mean daily energy intakes over 4 days in the conventional AMD, and FAD groups, respectively, were 32.4 (95% CI 28.7-36.6), 46.0 (CI 39.6-53.4), and 37.3 (CI 31.8-43.9) kcal/kg/day. The energy intake in the AMD group was 42% higher than the conventional group (p = 0.003). There were no significant differences between the groups for duration of diarrhea, frequency of stooling, or vomiting. Starch digestion using amylase from germination is an effective way of improving energy intake in children with acute diarrhea.

Iodine deficiency alone cannot account for goitre prevalence among pregnant women in Modhupur, Bangladesh

OBJECTIVE

We wished to determine the contributing causes of goitre among pregnant women in rural Bangladesh to provide baseline data before instituting iodine supplementation.

DESIGN

All pregnant women in a subdistrict of Modhupur, Bangladesh were assessed for goitre size and were asked to give blood and urine samples for measurement of iodine status and thyroid hormones.

SETTING

Field study in 72 villages in rural Modhupur.

SUBJECTS

356 women at all stages of gestation.

RESULTS

Total goitre prevalence was 99%, and 79% of the women had goitres of grade 2 or 3. Nevertheless, urinary iodine levels indicated only moderate iodine deficiency with 23% below 0.16 mumol/l and 62% below 0.39 mumol/l. Plasma thyroid-stimulating hormone was elevated in 19% of the women. Other dietary factors which could potentially contribute to goitre--vitamin A or selenium deficiency or intake of large amounts of thiocyanate-producing goitrogens--were found not to be a problem among these women. Multiple regression analysis of the causes of goitre, including measures of iodine status and anthropometric variables, could account for only 12% of the variability in goitre grade.

CONCLUSIONS

High goitre prevalence can occur even in the absence of severe iodine deficiency. Therefore, iodine supplementation may not completely solve a community goitre problem.

A mortality study of workers manufacturing friction materials: 1941-86

The mortality of workers employed at a factory producing friction materials has been studied from 1941 to 1986, extending a previous study by seven years. Apart from two periods before 1944, when crocidolite asbestos was used on one particular contract, only chrysotile asbestos has been used. Thirteen deaths were attributed to mesothelioma and of these, 11 were of subjects who had known contact with crocidolite asbestos. Of the remaining two, in one instance the diagnosis is uncertain and in the other the occupational history of the subject is not well established. There was no excess of deaths from lung cancer or other asbestos related tumours, or from chronic respiratory disease. After 1950 hygienic control was progressively improved and from 1970 levels of asbestos in air have not exceeded 0.5-1.0 f/ml. It is concluded that with good environmental control chrysotile asbestos may be used in manufacture without causing excess mortality.

Mortality of cadmium-exposed workers. A five-year update

A cohort mortality study of cadmium-exposed workers initially followed to the end of 1979 has been updated for a further five years. The update has confirmed the findings of the original study with a significant excess risk from bronchitis related to intensity of exposure, although over the five-year period the excess mortality was no longer significant, a finding suggesting that the risk from bronchitis may now be declining in this cohort. In contrast, there is now a stronger indication of a excess risk from lung cancer related to intensity of exposure, significant for both the total and the five-year periods. There was again no increased risk from prostatic cancer, and from this and other studies it appears unlikely that cadmium, in the concentrations encountered in this and other recent studies, acts as a prostatic carcinogen. As in the initial study, there was no significant excess risk from hypertensive disease, nor any suggestion of an increased risk from cerebrovascular or renal disease.

Mortality of workers at acetylene production plants

To reduce the risk of explosion oxyacetylene cylinders are filled with a spongy mass, acetone is added to saturate the mass, and acetylene is pumped into the cylinder. The first cylinders manufactured before 1936 used a kapok filling topped off with about 16 oz of crocidolite asbestos, with a metal gauze thimble inserted to reduce risk of flash back. Cylinders must be examined annually. The use of crocidolite ceased in 1972 and other fillings have been adopted since 1970; kapok cylinders now constitute less than 5% of the total stock. To assess possible hazards, a mortality study of workers first employed between 1935 and 1975 and followed up to December 1984 was undertaken. Simulation tests showed low concentrations of asbestos in the air even in the earliest period. The population studied consisted of 370 workers at the Bilston plant in the West Midlands, 611 at the 14 other plants in England and Wales, and 120 in Scotland. No deaths occurred from mesothelial tumours but there was an excess of deaths from cancer, particularly lung cancer, cancer of the stomach, and cancer of the pancreas, the latter accounting for eight deaths. Risks appeared to be concentrated at the Bilston plant. The importance of these findings is discussed.