Observations from a hospital bed

No Abstract

The application of single-strand conformation polymorphism (SSCP) technique for the analysis of molecular heterogeneity of grapevine virus A

The results of the analysis of grapevine virus A (GVA) isolates by single-strand conformation polymorphism (SSCP) confirm that this technique is very helpful in rapid and relatively low cost preliminary analysis of molecular heterogeneity of viruses. The results clearly show that the reliability of SSCP analysis of GVA depends on oligonucleotide primers for successful RT-PCR amplification of the highest possible number of molecular variants of the virus. Among 7 pairs of GVA-specific primers designed in different laboratories only two, those from Canada (117038 and C7273) and Switzerland (MP and CPdt), allowed positive RT-PCR amplification of all our isolates of the virus mechanically transmitted from various grapevines to Nicotiana benthamiana. With SSCP analysis of 238 bp DNA fragments complementary to part of ORF5 of GVA, produced by RT-PCR using the first pair of primers, we were able to detect 1-35 nt differences between GVA isolates. The DNA fragments, about 986 bp, complementary to part of ORF3 and ORF4, ORF5 and 3'UTR of GVA, produced by RT-PCR using the second pair of primers, were useful for SSCP analysis only after their digestion with the restriction enzyme DdeI. The results strongly suggest that SSCP analysis of 238 nt fragment of ORF5 of GVA along with DdeI/SSCP analysis of about 986 nt 3'terminal fragment of the virus allow rapid and reliable determination of the number of dominant nt sequence variants of GVA present in a single N. benthamiana or grapevine plant.

Single-strand conformation polymorphism (SSCP), cloning and sequencing reveals two major groups of divergent molecular variants of grapevine leafroll-associated virus 3 (GLRaV-3)

The SSCP and RE/SSCP analysis of ORF5, ORF6 and ORF7 of 25 local and overseas isolates of GLRaV-3 showed only two kinds of distinct SSCP profiles for each of these genomic regions. It suggested low molecular variability of the virus. Fragments of the 5’UTR + ORF1a, 3’ terminal part of ORF1a, ORF4, ORF5, ORF6 and ORF7 of three isolates, representing distinct SSCP profiles, were cloned and sequenced. Results revealed that although the 3’terminal half of the genome (ORF4-7) and the sequence located in the 3’ terminal part of ORF1a were relatively similar among isolates (91.3-96.2 % nt identity), their 5’terminal parts (88 nt of 5’UTR and adjacent first 329 nt of ORF1a) were clearly divergent (81.6-81.8 % nt identity). Analysis of this divergent part of GLRaV-3 for an additional 11 isolates showed that they cluster in two distinct molecular groups, sharing 94.7-99.7 % and 80.8-85.1 % nt identity within and between groups respectively. The correlation between the molecular groups and SSCP profiles of the 209 nt fragment of ORF5 of GLRaV-3 strongly suggests that SSCP analysis of this easily RT-PCR amplified region can be used for rapid identification of divergent molecular variants of the virus in field-collected grapevine samples.

East salt sparingly - sprinkle, don\u27t shake!

The salt-blood pressure hypothesis states that an excessive salt intake leads to an increase in blood pressure in genetically susceptible persons and, if high intake is maintained long term, ultimately leads to sustained hypertension. It is estimated that about 3.3 million South Africans (12.6% and 16.3% of adult men and women, respectively) are hypertensive. However, not all subjects within a particular population respond equally to exposure to high-salt diets. Methods to identify those who are \u27salt sensitive\u27 remain in the research domain; therefore a population approach to the restriction of dietary salt intake is warranted. The message to \u27eat salt sparingly\u27 will not interfere with the current nutritional and legal requirements regarding iodation of table salt. A salt intake as low as 5 g per day would provide an adequate amount of iodine, provided the salt is sufficiently iodated. Dietary factors other than sodium which have been shown to influence blood pressure include potassium, magnesium, calcium and alcohol. The \u27Dietary Approaches to Stop Hypertension\u27 (DASH) randomised controlled trial found that subjects fed a diet rich in fruit and vegetables for 8 weeks significantly reduced both systolic and diastolic blood pressure, compared with subjects on a typical American control diet. A \u27combination\u27 diet, rich in fruit, vegetables and low-fat dairy products, and with a reduced saturated and total fat intake, resulted in an even greater reduction in blood pressure. Translated into a practical diet, this information suggests a daily diet that includes large amounts of fruit and vegetables, a moderate intake of low-fat dairy products, lean meat and chicken, and a prudent alcohol intake. Salt should be used sparingly, if at all, at the table and in the preparation of meals, and the intake of processed foods high in salt should be limited. This would result in a reduction in intake from an average of around 9 g salt to about 6 g salt per day, which is the current USA recommendation. These blood pressure-related recommendations incorporate many of the various foodbased dietary guidelines, emphasising that the recommendations are congruent and mutually substantiative

Iodine status of pregnant women and children age 6 to 12 years feeding from the same food basket in Mopani district, Limpopo province, South Africa

Objectives: The aim of the study was to assess the iodine status of pregnant women and children age 6 to 12 years feeding from the same food basket in Mopani District. Design: A cross-sectional study was conducted. Setting: The setting was primary health care clinics and households from five municipalities of Mopani District in Limpopo province. Subjects: A total of 565 conveniently selected pregnant women and 116 children aged 6 to 12 years were recruited, of which 116 were mother–child pairs. Methods: The demographic information, iodine nutrition knowledge and salt consumption patterns were obtained using a validated questionnaire. Spot urine, household drinking water and salt samples were collected and analysed for iodine using standard procedures. A professional nurse, using filter paper to determine thyroid stimulating hormone (TSH) levels, collected spot finger-stick blood samples from pregnant women. Results: The findings showed that only 52.5% of household salt had an iodine concentration level of more than and equal to 15 ppm. The median iodine concentration of household drinking water was 46.2 μg/l (interquartile range [IQR] 10.8–73.4 μg/l). The TSH levels of the majority of pregnant women were normal and the maternal overall median urinary iodine concentration (UIC) was 164 μg/l (IQR 92–291 μg/l), indicating maternal iodine sufficiency. However, median UIC in the first and third trimesters was below 150 μg/l, indicating iodine insufficiency. The UIC level of children in the study was 386 μg/l (IQR 200–525 μg/l), signifying iodine excess. Conclusion: Iodine status of pregnant women in this study was sufficient, with UIC for children excessively high, more than two times higher than the iodine status of pregnant women. The reasons for the excessive UIC in school-age children need to be elucidated

Knowledge of iodine nutrition in the South African adult population

OBJECTIVES: To determine the level of knowledge regarding iodine nutrition and its relationship with socio-economic status in the South African population. DESIGN: A cross-sectional population survey collecting questionnaire information on knowledge of iodine nutrition and sociodemographic variables in a multistage, stratified, cluster study sample, representative of the adult South African population. SETTING: Home visits and personal interviews in the language of the respondent. SUBJECTS: Data were collected from one adult in each of the selected 2164 households, and the participation rate was 98%. RESULTS: Only 15.4% of respondents correctly identified iodised salt as the primary dietary source of iodine, 16.2% knew the thyroid gland needs iodine for its functioning, and a mere 3.9% considered brain damage, and 0.8% considered cretinism, as the most important health consequence of iodine deficiency. Compared with respondents from high socio-economic households, respondents from low socio-economic households were considerably less informed about aspects of iodine nutrition covered in this study. CONCLUSIONS: The knowledge level of iodine nutrition is low among South Africans, particularly among the low socio-economic groups. These data suggest that the international emphasis on brain damage resulting from iodine deficiency has not been conveyed successfully to the consumer level in this country

Health promotion: From malaria control to elimination

Here we reflect on the achievement of some of the diverse activities that have brought malaria under control, highlight key challenges and propose specific health promotion interventions required to move South Africa’s malaria programme from control to elimination

Grapevine leafroll-associated virus 3.

Grapevine leafroll disease (GLD) is one of the most important grapevine viral diseases affecting grapevines worldwide. The impact on vine health, crop yield, and quality is difficult to assess due to a high number of variables, but significant economic losses are consistently reported over the lifespan of a vineyard if intervention strategies are not implemented. Several viruses from the family Closteroviridae are associated with GLD. However, Grapevine leafroll-associated virus 3 (GLRaV-3), the type species for the genus Ampelovirus, is regarded as the most important causative agent. Here we provide a general overview on various aspects of GLRaV-3, with an emphasis on the latest advances in the characterization of the genome. The full genome of several isolates have recently been sequenced and annotated, revealing the existence of several genetic variants. The classification of these variants, based on their genome sequence, will be discussed and a guideline is presented to facilitate future comparative studies. The characterization of sgRNAs produced during the infection cycle of GLRaV-3 has given some insight into the replication strategy and the putative functionality of the ORFs. The latest nucleotide sequence based molecular diagnostic techniques were shown to be more sensitive than conventional serological assays and although ELISA is not as sensitive it remains valuable for high-throughput screening and complementary to molecular diagnostics. The application of next-generation sequencing is proving to be a valuable tool to study the complexity of viral infection as well as plant pathogen interaction. Next-generation sequencing data can provide information regarding disease complexes, variants of viral species, and abundance of particular viruses. This information can be used to develop more accurate diagnostic assays. Reliable virus screening in support of robust grapevine certification programs remains the cornerstone of GLD management

Endemic goitre in a rural community of KwaZulu-Natal

CITATION: Benade, J. G. et al. 1997. Endemic goitre in a rural community of KwaZulu-Natal. South African Medical Journal, 87:310-313.The original publication is available at http://www.samj.org.zaObjective. To quantify the prevalence of goitre and iodine deficiency. Setting. Ndunakazi, a rural community of approximately 8 000 people in KwaZulu-Natal. Design. A cross-sectional community-based survey and a school-based survey. Participants. The 127 mothers and 114 children aged 6 -11 years, selected during the cross-sectional survey, and 304 children aged 6 -14 years, from the school-based survey. Methods. Urinary iodine levels and thyroid size were determined and categorised according to guidelines proposed jointly by the WHO, UNICEF and the ICCIDD. Z-score anthropometric indicators were calculated, and mid-year exam marks of goitrous and non-goitrous pupils for Zulu and mathematics were compared. Results. In school-aged children, both surveys demonstrated a goitre prevalence in the 20 - 29.9% range and a median urinary iodine level in the 2 - 4.9 ug/dl range, indicating iodine deficiency of moderate severity. Goitrous subjects scored consistently worse in their Zulu exam papers than those without goitre. Stunting was not more prevalent than in the rest of KwaZulu-Natal. Iodised salt was not available in any of the three community shops. Conclusion. This level of iodine deficiency in children can adversely affect their neuropsycho-intellectual development. Factors contributing to deficient iodine intake in Ndunakazi are present in many rural areas, and South Africa cannot afford to be overly confident about the apparent absence of iodine deficiency as a public health problem.Publisher’s versio