Development, standardization and refinement of procedures for evaluating effects of endocrine active compounds on development and sexual differentiation of Xenopus laevis

Xenopus laevis has been introduced as a model to study effects of endocrine-active compounds (EAC) on development and sexual differentiation. However, variable and inconsistent data have raised questions about the reliability of the test methods applied. The current study was conducted in two laboratories to develop, refine, and standardize procedures and protocols. Larvae were exposed in flow-through systems to 17β-estradiol (E2), at concentrations from 0.2 to 6.0 μg E2 L−1 in Experiment 1A, and 0.015 to 2.0 μg E2 L−1 in Experiment 1B. In both studies survival (92%, 99%) and percentage of animals that completed metamorphosis (97%, 99%) indicated reproducible biological performance. Furthermore, minor variations in husbandry led to significant differences in snout-to-vent length, weight, and gonad size. In Experiment 1A, almost complete feminization occurred in all E2 treatment groups whereas a concentration response was observed in Experiment 1B resulting in an EC50 of 0.12 μg E2 L−1. The final verified protocol is suitable for determining effects of EAC on development and sexual differentiation in X. laevis

Micronutrient fortification of food and its impact on woman and child health: A systematic review

Background: Vitamins and minerals are essential for growth and metabolism. The World Health Organization estimates that more than 2 billion people are deficient in key vitamins and minerals. Groups most vulnerable to these micronutrient deficiencies are pregnant and lactating women and young children, given their increased demands. Food fortification is one of the strategies that has been used safely and effectively to prevent vitamin and mineral deficiencies.Methods: A comprehensive search was done to identify all available evidence for the impact of fortification interventions. Studies were included if food was fortified with a single, dual or multiple micronutrients and impact of fortification was analyzed on the health outcomes and relevant biochemical indicators of women and children. We performed a meta-analysis of outcomes using Review Manager Software version 5.1.Results: Our systematic review identified 201 studies that we reviewed for outcomes of relevance. Fortification for children showed significant impacts on increasing serum micronutrient concentrations. Hematologic markers also improved, including hemoglobin concentrations, which showed a significant rise when food was fortified with vitamin A, iron and multiple micronutrients. Fortification with zinc had no significant adverse impact on hemoglobin levels. Multiple micronutrient fortification showed non-significant impacts on height for age, weight for age and weight for height Z-scores, although they showed positive trends. The results for fortification in women showed that calcium and vitamin D fortification had significant impacts in the post-menopausal age group. Iron fortification led to a significant increase in serum ferritin and hemoglobin levels in women of reproductive age and pregnant women. Folate fortification significantly reduced the incidence of congenital abnormalities like neural tube defects without increasing the incidence of twinning. The number of studies pooled for zinc and multiple micronutrients for women were few, though the evidence suggested benefit. There was a dearth of evidence for the impact of fortification strategies on morbidity and mortality outcomes in women and children.Conclusion: Fortification is potentially an effective strategy but evidence from the developing world is scarce. Programs need to assess the direct impact of fortification on morbidity and mortality

Opname van tevredenheid van B.Cur. - finalejaarstudente aan die Randse Afrikaanse Universiteit

Die doel van die studie was om die B.Cur.-vierdejaarstudente aan die Randse Afrikaanse Universiteit (RAU), van die jaar 2001, se tevredenheid ten opsigte van hulle B.Cur.-program te bepaal. Om die doelstelling te bereik, was die volgende doelwitte relevant, naamlik: 'n Beskrywing van die vlakke van tevredenheid van die B.Cur.-vierdejaarstudente aan die RAU. 'n Beskrywing van die verhouding tussen tevredenheid van die studente en hoe belangrik hulle sekere aspekte in die struktuur, prosesse en uitkomste van die universiteitsomgewing beskou. Die navorsingstudie was binne die konteks van die RAU uitgevoer. Die B.Cur.-kurrikulum is in 1998 gewysig. Dit is 'n graadkursus wat vier jaar duur, en tot registrasie as verpleegkundige (algemene, psigiatriese en gemeenskapsverpleegkunde) en vroedvrou lei. Die vierdejaarstudente van 2001 was die eerste groep wat die hersiene kurrikulum voltooi het. Dit was dus om hierdie rede sinvol om die studente-tevredenheid te evalueer. Ten einde die doelstelling te bereik is 'n kwantitatiewe opname-ontwerp gebruik. Die totale populasie (N=18) van die B.Cur.-vierdejaargroep is gebruik. 'n Bestaande instrument wat deur die RAU se Sentrum vir Hoëronderwysstudies, in die jaar 2000 ontwikkel is, is gebruik. Die meetinstrument was in die vorm van 'n Likertskaal wat op 'n numeriese waarde van 1 tot 7 gemeet het. Twee aspekte is aangeraak: die studente se metings van hulle vlakke van tevredenheid met elke item en hulle evaluering van die belangrikheid van elke item vir studente. Die navorser het die vraelys persoonlik aan elke student uitgedeel. Al 18 vraelyste wat uitgedeel was, is terugontvang. 'n Statistiese konsultant was behulpsaam met die beskrywende statistiek (frekwensies, persentasies, korrelasies, gemiddeldes en standaardafwykings) wat gebruik is om die data te ontleed en te beskryf. Die bevindings van die navorsing dui op 'n hoë vlak van tevredenheid van die studente. The purpose of this study was to determine the satisfaction of the B Cur fourth-year students (2001) at the Rand Afrikaans University (RAU), in terms of their B Cur programme. The following objectives were important for achieving this goal: A description of the levels of satisfaction of the B Cur fourth year students at the RAU. A description of the relationships between the satisfaction of the students and their rated importance of aspects like structure, process and outcomes of the university environment. This research study was carried out within the context of the RAU. The B Cur curriculum was modified in 1998. This is a four year degree course which leads to registration as a nurse (general, psychiatric and community) and midwife. The fourth-year students of 2001 were the first group to complete their studies with the revised curriculum. Thus it was important to evaluate student satisfaction. In order to achieve the purpose of the study, a quantitative survey design was used. The total population (N = 18) of the B Cur fourth-year group participated in the survey. An existing instrument (developed by the RAU's Centre for Higher Education Studies in 2000) was used to gather data. This measuring instrument comprises a Likert scale which measures numerical values from 1 to 7. Two important aspects were addressed: the students' ratings of their levels of satisfaction with each item and the evaluation of the importance of each item to students. The researcher personally handed the questionnaires to each student. All 18 questionnaires handed out, were returned to the researcher. With the help of a statistics consultant, descriptive statistics (frequency, percentages, correlations, standard deviation and mean) were used to analyse and describe the data. The findings of the research indicate a high level of students' satisfaction with their studies. Key words: Student / consumer satisfaction, Quality assurance, University education, Education programmes, Studente- / verbruikerstevredenheid, Kwaliteitversekering, Universiteitsopleiding, Opvoedkundige programme (Health SA Gesondheid: 2003 8(2): 48-62

The effect of dietary lipid sources on layer fertility and hatchability

This study was conducted to investigate the effect of dietary fatty acids (FA) on the fertility and hatchability of laying hens at the end-of-lay period (69 - 77 weeks of age). Five isoenergetic (12.4 MJ ME/kg DM) and isonitrogenous (170 g CP/kg DM) diets were formulated using different lipid sources (30 g/kg inclusion) to manipulate the dietary FA profile. The control diet was formulated using a 50 : 50 blend of linseed and fish oil, while fish oil was used in the polyunsaturated n-3 treatment. Sunflower oil was used in the polyunsaturated n-6 treatment, while in the mono-unsaturated n-9 diet high oleic acid (HO) sunflower oil was used. Lastly, tallow was used as a lipid source in the saturated FA diet. One hundred and twenty five hens (n = 25/treatment) and 50 cockerels (n = 10/treatment) of the Hy-Line Silver-Brown genotype were randomly allocated to the five dietary treatments at 20 weeks of age. From 69 weeks of age, hens were inseminated with 0.06 mL undiluted semen from cockerels within the same dietary treatment. Between 71 and 78 weeks of age (49 days) a total of 588 eggs-per-treatment were collected, individually marked (date and hen number) and incubated in a single-stage still-air incubator. Eggs were candled on D7 and D14 to determine embryonic mortalities and a 24 h window for hatching was allowed (D21 + 24 h). Although the fish oil treatment resulted in the lowest egg weights (59.3 g) and fertility (84.6%), it recorded the highest hatchability (76%). In contrast, the sunflower oil treatment recorded the lowest hatchability (58.2%) of all treatments, despite its high egg fertility (89.6%). Results of the study suggest that the dietary fatty acid content, in particular the n-3 and n-6 levels, need critical consideration in terms of concentration and ratio in the formulation of breeder diets to limit embryonic mortalities during incubation.Keywords: Chicks, embryo, mortality, mono-, polyunsaturated fatty acid

An overview of a cohort of South African patients with mitochondrial disorders

Mitochondrial disorders are frequently encountered inherited diseases characterized by unexplained multisystem involvement with a chronic, intermittent, or progressive nature. The objective of this paper is to describe the profile of patients with mitochondrial disorders in South Africa. Patients with possible mitochondrial disorders were accessed over 10 years. Analyses for respiratory chain and pyruvate dehydrogenase complex enzymes were performed on muscle. A diagnosis of a mitochondrial disorder was accepted only if an enzyme activity was deficient. Sixtythree patients were diagnosed with a mitochondrial disorder, including 40 African, 20 Caucasian, one mixed ancestry, and two Indian patients. The most important findings were the difference between African patients and other ethnicities: respiratory chain enzyme complexes CI+III or CII+III deficiencies were found in 52.5% of African patients, being of statistical significance (p value=0.0061). They also presented predominantly with myopathy (p value= 0.0018); the male:female ratio was 1:1.2. Twenty-five (62.5%) African patients presented with varying degrees of a myopathy accompanied by a myopathic face, high palate, and scoliosis. Fourteen of these 25 also had ptosis and/or progressive external ophthalmoplegia. No patients of other ethnicities presented with this specific myopathic phenotype. Caucasian patients (16/20) presented predominantly with central nervous system involvement. Of the South African pediatric neurology patients, Africans are more likely to present with myopathy and CII+III deficiency, and Caucasian patients are more likely to present with encephalopathy or encephalomyopath

Management of Colorectal Cancer Explains Differences in 1-year Relative Survival Between France and England for Patients Diagnosed 1997–2004

BACKGROUND: Few international population-based studies have provided information on potential determinants of international disparities in cancer survival. This population-based study was undertaken to identify the principal differences in disease characteristics and management that accounted for previously observed poorer survival in English compared with French patients with colorectal cancer. METHODS: The study population comprised all cases of colorectal cancer diagnosed between 1997 and 2004 in the areas covered by three population-based cancer registries in France and one in England (N=40 613). To investigate the influence of clinical and treatment variables on survival, we applied multivariable excess hazard modelling based on generalised linear models with Poisson error. RESULTS: Poorer survival for English patients was primarily due to a larger proportion dying within the first year after diagnosis. After controlling for inter-country differences in the use of chemotherapy and surgical resection with curative intent, country of residence was no-longer associated with 1-year survival for advanced colon cancer patients (excess hazard ratio (EHR)=0.99 (0.92-1.01), P=0.095)). Longer term (2-5 years) excess hazards of death for colon and rectal cancer patients did not differ between France and England. CONCLUSION: This study suggests that difference in management close to diagnosis of colon and rectum cancer is related to differences in survival observed between France and England. All efforts (collection and standardisation of additional variables such as co-morbidity) to investigate the reasons for these disparities in management between these two countries, and more generally across Europe, should be encouraged