Nutraceutical approaches to non-alcoholic fatty liver disease (NAFLD): A position paper from the International Lipid Expert Panel (ILEP)

Non-Alcoholic Fatty Liver Disease (NAFLD) is a common condition affecting around 10-25% of the general adult population, 15% of children, and even > 50% of individuals who have type 2 diabetes mellitus. It is a major cause of liver-related morbidity, and cardiovascular (CV) mortality is a common cause of death. In addition to being the initial step of irreversible alterations of the liver parenchyma causing cirrhosis, about 1/6 of those who develop NASH are at risk also developing CV disease (CVD). More recently the acronym MAFLD (Metabolic Associated Fatty Liver Disease) has been preferred by many European and US specialists, providing a clearer message on the metabolic etiology of the disease. The suggestions for the management of NAFLD are like those recommended by guidelines for CVD prevention. In this context, the general approach is to prescribe physical activity and dietary changes the effect weight loss. Lifestyle change in the NAFLD patient has been supplemented in some by the use of nutraceuticals, but the evidence based for these remains uncertain. The aim of this Position Paper was to summarize the clinical evidence relating to the effect of nutraceuticals on NAFLD-related parameters. Our reading of the data is that whilst many nutraceuticals have been studied in relation to NAFLD, none have sufficient evidence to recommend their routine use; robust trials are required to appropriately address efficacy and safety.

Step-by-step diagnosis and management of the nocebo/drucebo effect in statin-associated muscle symptoms patients: a position paper from the International Lipid Expert Panel (ILEP)

Statin intolerance is a clinical syndrome whereby adverse effects (AEs) associated with statin therapy [most commonly statin-associated muscle symptoms (SAMS)] result in the discontinuation of therapy and consequently increase the risk of adverse cardiovascular outcomes. However, complete statin intolerance occurs in only a small minority of treated patients (estimated prevalence of only 3-5%). Many perceived AEs are misattributed (e.g. physical musculoskeletal injury and inflammatory myopathies), and subjective symptoms occur as a result of the fact that patients expect them to do so when taking medicines (the nocebo/drucebo effect)-what might be truth even for over 50% of all patients with muscle weakness/pain. Clear guidance is necessary to enable the optimal management of plasma in real-world clinical practice in patients who experience subjective AEs. In this Position Paper of the International Lipid Expert Panel (ILEP), we present a step-by-step patient-centred approach to the identification and management of SAMS with a particular focus on strategies to prevent and manage the nocebo/drucebo effect and to improve long-term compliance with lipid-lowering therapy.

Risk Assessment and Clinical Management of Children and Adolescents with Heterozygous Familial Hypercholesterolaemia. A Position Paper of the Associations of Preventive Pediatrics of Serbia, Mighty Medic and International Lipid Expert Panel

Heterozygous familial hypercholesterolaemia (FH) is among the most common genetic metabolic lipid disorders characterised by elevated low-density lipoprotein cholesterol (LDL-C) levels from birth and a significantly higher risk of developing premature atherosclerotic cardiovascular disease. The majority of the current pediatric guidelines for clinical management of children and adolescents with FH does not consider the impact of genetic variations as well as characteristics of vascular phenotype as assessed by recently developed non-invasive imaging techniques. We propose a combined integrated approach of cardiovascular (CV) risk assessment and clinical management of children with FH incorporating current risk assessment profile (LDL-C levels, traditional CV risk factors and familial history) with genetic and non-invasive vascular phenotyping. Based on the existing data on vascular phenotype status, this panel recommends that all children with FH and cIMT ≥0.5 mm should receive lipid lowering therapy irrespective of the presence of CV risk factors, family history and/or LDL-C levels Those children with FH and cIMT ≥0.4 mm should be carefully monitored to initiate lipid lowering management in the most suitable time. Likewise, all genetically confirmed children with FH and LDL-C levels ≥4.1 mmol/L (160 mg/dL), should be treated with lifestyle changes and LLT irrespective of the cIMT, presence of additional RF or family history of CHD.

Risk Factors for Coronavirus Disease 2019 (COVID-19) Death in a Population Cohort Study from the Western Cape Province, South Africa

BACKGROUND

Risk factors for coronavirus disease 2019 (COVID-19) death in sub-Saharan Africa and the effects of human immunodeficiency virus (HIV) and tuberculosis on COVID-19 outcomes are unknown.

METHODS

We conducted a population cohort study using linked data from adults attending public-sector health facilities in the Western Cape, South Africa. We used Cox proportional hazards models, adjusted for age, sex, location, and comorbidities, to examine the associations between HIV, tuberculosis, and COVID-19 death from 1 March to 9 June 2020 among (1) public-sector "active patients" (≥1 visit in the 3 years before March 2020); (2) laboratory-diagnosed COVID-19 cases; and (3) hospitalized COVID-19 cases. We calculated the standardized mortality ratio (SMR) for COVID-19, comparing adults living with and without HIV using modeled population estimates.

RESULTS

Among 3 460 932 patients (16% living with HIV), 22 308 were diagnosed with COVID-19, of whom 625 died. COVID-19 death was associated with male sex, increasing age, diabetes, hypertension, and chronic kidney disease. HIV was associated with COVID-19 mortality (adjusted hazard ratio [aHR], 2.14; 95% confidence interval [CI], 1.70-2.70), with similar risks across strata of viral loads and immunosuppression. Current and previous diagnoses of tuberculosis were associated with COVID-19 death (aHR, 2.70 [95% CI, 1.81-4.04] and 1.51 [95% CI, 1.18-1.93], respectively). The SMR for COVID-19 death associated with HIV was 2.39 (95% CI, 1.96-2.86); population attributable fraction 8.5% (95% CI, 6.1-11.1).

CONCLUSIONS

While our findings may overestimate HIV- and tuberculosis-associated COVID-19 mortality risks due to residual confounding, both living with HIV and having current tuberculosis were independently associated with increased COVID-19 mortality. The associations between age, sex, and other comorbidities and COVID-19 mortality were similar to those in other settings.

Chronic and moderate consumption of reduced-alcohol wine confers cardiac benefits in a rat model of pulmonary arterial hypertension

OBJECTIVES

In pulmonary arterial hypertension (PAH), right ventricular (RV) dysfunction develops via mechanisms involving oxidative stress. Moderate and chronic red wine (RW) consumption reduces oxidative stress and confers cardioprotection but its effect on PAH is unknown. We evaluated whether moderate and chronic consumption of reduced-alcohol RW (RARW) confers cardioprotection in a monocrotaline (MCT)-induced PAH rat model.

RESULTS

Rats were randomly grouped: control; MCT; RARW; MCT + RARW. Wine was diluted to mimic moderate intake for humans, and consumed from 7 days before, until 28 days after MCT-injection. Echocardiography measured pulmonary artery acceleration time (PAAT) and RV thickness. Conjugated dienes (CD), and thiobarbituric acid reactive substances (TBARS) concentrations were assessed. MCT induced RV thickness and decreased PAAT compared to controls [1.22 ± 0.09 mm vs 0.46 ± 0.02 mm and 14 ± 1 vs 23 ± 2 m/s, respectively (p < 0.001)]. Chronic RARW consumption limited MCT-induced RV hypertrophy and increased PAAT. CD and TBARS increased in MCT-treated animals compared to controls (672 ± 43 nmol/L vs 453 ± 35 nmol/L; p < 0.01 and 13 ± 2 µmol/L vs 4 ± 0.3 µmol/L; p < 0.01). RARW reduced MCT-induced CD (472 ± 27 nmol/L vs 672 ± 43 nmol/L; p < 0.01).

CONCLUSION

Chronic and moderate intake of RARW ameliorates MCT-induced PAH in rats, which may be partly attributable to reduction of lipid peroxidation.

Reducing the Clinical and Public Health Burden of Familial Hypercholesterolemia: A Global Call to Action

Importance

Familial hypercholesterolemia (FH) is an underdiagnosed and undertreated genetic disorder that leads to premature morbidity and mortality due to atherosclerotic cardiovascular disease. Familial hypercholesterolemia affects 1 in 200 to 250 people around the world of every race and ethnicity. The lack of general awareness of FH among the public and medical community has resulted in only 10% of the FH population being diagnosed and adequately treated. The World Health Organization recognized FH as a public health priority in 1998 during a consultation meeting in Geneva, Switzerland. The World Health Organization report highlighted 11 recommendations to address FH worldwide, from diagnosis and treatment to family screening and education. Research since the 1998 report has increased understanding and awareness of FH, particularly in specialty areas, such as cardiology and lipidology. However, in the past 20 years, there has been little progress in implementing the 11 recommendations to prevent premature atherosclerotic cardiovascular disease in an entire generation of families with FH.

Observations

In 2018, the Familial Hypercholesterolemia Foundation and the World Heart Federation convened the international FH community to update the 11 recommendations. Two meetings were held: one at the 2018 FH Foundation Global Summit and the other during the 2018 World Congress of Cardiology and Cardiovascular Health. Each meeting served as a platform for the FH community to examine the original recommendations, assess the gaps, and provide commentary on the revised recommendations. The Global Call to Action on Familial Hypercholesterolemia thus represents individuals with FH, advocacy leaders, scientific experts, policy makers, and the original authors of the 1998 World Health Organization report. Attendees from 40 countries brought perspectives on FH from low-, middle-, and high-income regions. Tables listing country-specific government support for FH care, existing country-specific and international FH scientific statements and guidelines, country-specific and international FH registries, and known FH advocacy organizations around the world were created.

Conclusions and Relevance

By adopting the 9 updated public policy recommendations created for this document, covering awareness; advocacy; screening, testing, and diagnosis; treatment; family-based care; registries; research; and cost and value, individual countries have the opportunity to prevent atherosclerotic heart disease in their citizens carrying a gene associated with FH and, likely, all those with severe hypercholesterolemia as well.

Analysis of the regenerative capacity of human serum exosomes after a simple multistep separation from lipoproteins

Due to the abundance of lipoproteins in blood, it is challenging to characterize the biological functions and components of blood-derived extracellular vesicles. The aim of this study was to develop a multiple-step purification protocol to separate serum exosomes from serum proteins and lipoproteins and assess their regenerative potential. Exosomes were isolated by concentrating them in human serum using ultracentrifugation (UC), followed sequentially by density gradient (DG) UC and size exclusion chromatography (SEC). Purity and characterization were assessed by western blots, Lipoprint®, enzyme-linked immunosorbent assay, electron microscopy, mass spectrometry, and nanoparticle tracking analysis. Functionality was assessed by cell proliferation analysis and with an in vivo subcutaneous angiogenesis model. SEC alone isolated nano-sized vesicles possessing vesicle markers TSG101 and CD9, but there was a substantial presence of apolipoprotein B, predominantly derived from very-low- and intermediate-density lipoprotein particles. This was reduced to an undetectable level using the combined UC DG SEC approach. Mass spectrometry identified 224 proteins in UC DG SEC isolates relative to the 135 from SEC, with considerable increases in exosome-related proteins and reductions in lipoproteins. A consistent but limited increase in human dermal fibroblast proliferation and evidence of neovascularization enhancement were observed after exposure to UC DG SEC exosomes. An UC DG SEC purification protocol considerably improved the removal of lipoproteins during isolation of serum exosomes. The purified exosomes stimulated cell proliferation and potentially increased an in vivo angiogenic response. This multistep purification allows for more accurate identification of serum exosome functional activity and composition.

Considerations for the design of nutrition-sensitive production programmes in rural South Africa

Background

Very little has been researched about the efficacy, effectiveness, feasibility, sustainability and impact of food-based approaches on the diets and nutritional status of populations at risk of hunger and food insecurity. This study contributes knowledge about the impact of food-based approaches on the diets of populations at risk of hunger and food insecurity in four of the poorest rural communities in South Africa. The study investigated the consumption and production patterns of rural households (278 in summer and 280 in winter) in four sites in the poorest municipalities in South Africa.

Methods

A multistage stratified random sampling technique was applied to identify the communities and sample households for the quantitative survey and qualitative assessments. Qualitative and quantitative data were collected between 2013 and 2015 through focus group discussions (FGDs), key informant interviews and the two-round panel survey to cover both the summer and winter seasons at each site.

Results

Home gardening led to a significant positive increase in the consumption of white roots and tubers, dark green leafy vegetables, orange-coloured fruit and other fruit in the 24 h prior to the survey. Participation in a community garden led to significant increases in the consumption of dark green leafy vegetables and other vegetables. School gardening did not demonstrate any statistical relationships with the consumption of foods from the crop-related food groups. Crop production improved dietary diversity. Selling produce and irrigation showed a stronger improvement in dietary diversity. Seasonality affected the availability of fresh fruit and vegetables for home consumption in winter.

Conclusions

Producing beyond that solely for home consumption has greater benefits for dietary diversity and a consumption-smoothing effect during the post-harvest period. Politicians and the scientific community should recognise the role that household and small-scale crop production plays in supporting household consumption and the provision of essential micronutrients despite constraints and disincentives. Production and education programmes should focus on strengthening existing good consumption patterns and promoting the consumption of foods that can improve dietary diversity.

Modern prevalence of dysbetalipoproteinemia (Fredrickson-Levy-Lees type III hyperlipoproteinemia)

INTRODUCTION

Dysbetalipoproteinaemia (HLP3) is a disorder characterized by excess cholesterol-enriched, triglyceride-rich lipoprotein remnants in genetically predisposed individuals that powerfully promote premature cardiovascular disease if untreated. The current prevalence of HLP3 is largely unknown.

MATERIAL AND METHODS

We performed cross-sectional analysis of 128,485 U.S. adults from the Very Large Database of Lipids (VLDbL), using four algorithms to diagnose HLP3 employing three Vertical Auto Profile ultracentrifugation (UC) criteria and a previously described apolipoprotein B (apoB) method. We evaluated 4,926 participants from the 2011-2014 National Health and Nutrition Examination Survey (NHANES) with the apoB method. We examined demographic and lipid characteristics stratified by presence of HLP3 and evaluated lipid characteristics in those with HLP3 phenotype discordance and concordance as determined by apoB and originally defined UC criteria 1.

RESULTS

In U.S. adults in VLDbL and NHANES, a 1.7-2.0% prevalence is observed for HLP3 with the novel apoB method as compared to 0.2-0.8% prevalence in VLDbL via UC criteria 1-3. Participants who were both apoB and UC criteria HLP3 positive had higher remnant particles as well as more elevated triglyceride/apoB and total cholesterol/apoB ratios (all p < 0.001) than those who were apoB method positive and UC criteria 1 negative.

CONCLUSIONS

HLP3 may be more prevalent than historically and clinically appreciated. The apoB method increases HLP3 identification via inclusion of milder phenotypes. Further work should evaluate the clinical implications of HLP3 diagnosis at various lipid algorithm cut-points to evaluate the ideal standard in the modern era.

Cardiology-cardiothoracic subspeciality training in South Africa: a position paper of the South Africa Heart Association

Over the past decades, South Africa has undergone rapid demographic changes, which have led to marked increases in specific cardiac disease categories, such as rheumatic heart disease (now predominantly presenting in young adults with advanced and symptomatic disease) and coronary artery disease (with rapidly increasing prevalence in middle age). The lack of screening facilities, delayed diagnosis and inadequate care at primary, secondary and tertiary levels have led to a large burden of patients with heart failure. This leads to suffering of the patients and substantial costs to society and the healthcare system.

In this position paper, the South African Heart Association (SA Heart) National Council members have summarised the current state of cardiology, cardiothoracic surgery and paediatric cardiology reigning in South Africa. Our report demonstrates that there has been minimal change in the number of successfully qualified specialists over the last decade and, therefore, a de facto decline per capita. We summarise the major gaps in training and possible interventions to transform the healthcare system, dealing with the colliding epidemic of communicable disease and the rapidly expanding epidemic of non-communicable disease, including cardiac disease.

Novel APOB missense variants, A224T and V925L, in a black South African woman with marked hypocholesterolemia

BACKGROUND

One genetic cause of markedly low plasma concentrations of apolipoprotein (apo) B and low density lipoprotein (LDL)-cholesterol is familial hypobetalipoproteinemia.

OBJECTIVE

We aimed to determine the molecular basis for the marked hypocholesterolemia consistent with heterozygous familial hypobetalipoproteinemia in a black female subject of Xhosa lineage.

METHODS

Coding regions of APOB, MTTP, PCSK9,ANGPTL3, SAR1B and APOC3 were sequenced, and APOE was genotyped. COS-7 cells were transfected with plasmids containing apoB variants. Western blotting was used to detect cellular and secreted apoB, and co-immunoprecipitation performed to assess binding with the microsomal triglyceride transfer protein (MTP).

RESULTS

Sequence analysis of the APOB gene revealed her to be heterozygous for two novel variants, c.751G>A (A224T) and c.2854G>C (V925L). She was also homozygous for the APOEε2 allele, and did not carry a PCSK9 loss-of-function mutation. Although Ala(224) is within the postulated MTP binding region in apoB, it is not conserved among mammalian species. Subsequent genotyping showed that Ala224Thr is found in a southern African population (n=654) with an allele frequency of 1.15% and is not associated with plasma lipid levels. Val(925), like Ala(224), is within the N-terminal 1000 amino acids required for lipoprotein assembly, but was not found in the population screen. However, in vitro studies showed that apoB V925L did not affect apoB48 production or secretion nor have a deleterious effect on MTP interaction with apoB.

CONCLUSION

Taken together, this suggests that the hypocholesterolemia in our case may be a result of being homozygous for APOEε2 with a low baseline cholesterol.

Views of medical students: what, when and how do they want statistics taught?

BACKGROUND

A key skill for a practising clinician is being able to do research, understand the statistical analyses and interpret results in the medical literature. Basic statistics has become essential within medical education, but when, what and in which format is uncertain.

METHODS

To inform curriculum design/development we undertook a quantitative survey of fifth year medical students and followed them up with a series of focus groups to obtain their opinions as to what statistics teaching they want, when and how.

RESULTS

A total of 145 students undertook the survey and five focus groups were held with between 3 and 9 participants each. Previous statistical training varied and students recognised their knowledge was inadequate and keen to see additional training implemented. Students were aware of the importance of statistics to their future careers, but apprehensive about learning. Face-to-face teaching supported by online resources was popular. Focus groups indicated the need for statistical training early in their degree and highlighted their lack of confidence and inconsistencies in support.

CONCLUSION

The study found that the students see the importance of statistics training in the medical curriculum but that timing and mode of delivery are key. The findings have informed the design of a new course to be implemented in the third undergraduate year. Teaching will be based around published studies aiming to equip students with the basics required with additional resources available through a virtual learning environment.

Dysbetalipoproteinemia: an extreme disorder of remnant metabolism

PURPOSE OF REVIEW

Lipoprotein metabolism and the role of apolipoprotein E in the pathogenesis of dysbetalipoproteinemia.

RECENT FINDINGS

Remnant lipoproteins, modulated by lifestyle and genetic factors, are atherogenic. Dysbetalipoproteinemia could be viewed as a monogenic disorder of remnant metabolism.

SUMMARY

Elevated plasma triglyceride and cholesterol concentrations (mixed hyperlipidemias) are commonly encountered and dysbetaliproteinemia should be considered in this setting. Dysbetalipoproteinemia (remnant clearance disease, Fredrickson type III hyperlipidemia) is an uncommon dyslipoproteinemia related to mutations in apolipoprotein E that disrupt the clearance of remnants of triglyceride-rich lipoproteins; it may be overlooked because xanthomata of the skin and/or tendons occur in a minority of patients. The diagnosis ideally requires the demonstration of remnant lipoprotein accumulation and a genetic cause. Genotyping for apolipoprotein E2 may not prove the diagnosis as it may be associated with low plasma lipid values. The recent association of remnant lipoproteins with atherosclerosis along with many factors that modulate remnant lipoprotein metabolism underscores the importance of recognising dysbetalipoproteinemia as an extreme state of remnant lipoprotein accumulation. Although there may be some differences between remnants in the general population and dysbetalipoproteinemia, it is clear that remnants promote atherosclerosis. Current treatment strategies are adequate but new strategies could also be of benefit in dysbetalipoproteinemia.

Cardiovascular risk factors in patients with Addison's disease: a comparative study of South African and Swedish patients

BACKGROUND

Patients with Addison's disease (AD) in Scandinavia have an increased risk for premature death due to cardiovascular disease (CVD). Serum lipids are important risk factors for CVD and vascular mortality. Replacement doses of hydrocortisone have historically been higher in Sweden than South Africa. The primary aim was to study the lipid profiles in a large group of patients with AD with the hypothesis that the lipid profile in patients in Sweden would be worse than in South Africa.

METHODS

In a cross-sectional study, 110 patients with AD (55 from South Africa, 55 from Sweden) matched for age, gender, ethnicity and BMI were studied. Anthropometric measures, blood pressure, lipids, highly sensitive C-reactive protein (hs-CRP) and adiponectin were studied.

RESULTS

All patients were Caucasian and the majority were women N = 36 (65.5%). Mean (standard deviation; SD) ages of the Swedish and South African patients were 52.9 (13.0) and 52.6 (14.4) years and BMI 25.3 (3.2) and 25.8 (4.1) kg/m2, respectively. The mean total daily hydrocortisone dose was greater in the Swedish patients than the South African patients, [33.0 (8.1) versus 24.3 (8.0) mg; p<0.0001]. South African patients had higher median (interquartilerange; IQR) triglycerides (TG) [1.59 (1.1-2.46) versus 0.96 (0.74-1.6) mmol/l; p<0.001], total cholesterol (TC) [6.02(1.50) versus 5.13 (0.87) mmol/l; p<0.001], LDL-C [4.43 (1.44) versus 2.75 (0.80) mmol/l; p<0.001] and median hs-CRP [2.15 (0.93-5.45) versus 0.99 (0.57-2.10) mg/L; p<0.003] and lower HDL-C [0.80 (0.40) versus 1.86 (0.46) mmol/l; p<0.001] than the Swedish patients. Approximately 20% of the patients in both cohorts had hypertension and diabetes mellitus.

CONCLUSIONS

South African patients with AD have worse lipid profiles and higher hs-CRP compared to their matched Swedish patients, despite lower doses of hydrocortisone. It is uncertain at this time whether these are due to genetic or environmental factors.

Chronic melatonin consumption prevents obesity-related metabolic abnormalities and protects the heart against myocardial ischemia and reperfusion injury in a prediabetic model of diet-induced obesity

Obesity, a major risk factor for ischemic heart disease, is associated with increased oxidative stress and reduced antioxidant status. Melatonin, a potent free radical scavenger and antioxidant, has powerful cardioprotective effects in lean animals but its efficacy in obesity is unknown. We investigated the effects of chronic melatonin administration on the development of the metabolic syndrome as well as ischemia-reperfusion injury in a rat model of diet-induced obesity (DIO). Male Wistar rats received a control diet, a control diet with melatonin, a high-calorie diet, or a high-calorie diet with melatonin (DM). Melatonin (4 mg/kg/day) was administered in the drinking water. After 16 wk, biometric and blood metabolic parameters were measured. Hearts were perfused ex vivo for the evaluation of myocardial function, infarct size (IFS) and biochemical changes [activation of PKB/Akt, ERK, p38 MAPK, AMPK, and glucose transporter (GLUT)-4 expression). The high-calorie diet caused increases in body weight (BW), visceral adiposity, serum insulin and triglycerides (TRIG), with no change in glucose levels. Melatonin treatment reduced the BW gain, visceral adiposity, blood TRIG, serum insulin, homeostatic model assessment index and thiobarbituric acid reactive substances in the DIO group. Melatonin reduced IFS in DIO and control groups and increased percentage recovery of functional performance of DIO hearts. During reperfusion, hearts from melatonin-treated rats had increased activation of PKB/Akt, ERK42/44 and reduced p38 MAPK activation. Chronic melatonin treatment prevented the metabolic abnormalities induced by DIO and protected the heart against ischemia-reperfusion injury. These beneficial effects were associated with activation of the reperfusion injury salvage kinases pathway.

Community genetics. Its definition 2010

This paper presents a definition of the medical field of community genetics. It starts with a brief historical overview, defines the requirements for an adequate definition, presents the definition, and discusses the constituent parts of the definition.

An assessment of preliminary food-based dietary guidelines for infants 6–12 months of age in the Little Karoo area of the Western Cape Province of South Africa

Objective

This study aimed to assess mother's/caregiver's understanding, practical application and cultural acceptability of a preliminary set of South African food-based dietary guidelines (FBDGs) for children aged 6–12 months living in the Little Karoo area of the Western Cape Province.

Design

An observational, descriptive and cross-sectional study design was followed. Focus group interviews, recorded on videotape, were analysed for qualitative data. Quantitative questionnaires measured knowledge and comprehension of guidelines, perceived constraints to compliance with and importance of guidelines as well as socio demographic data prior to the focus group interviews.

Setting

Afrikaans-, English- and Xhosa-speaking communities of the Little Karoo area of the Western Cape Province of South Africa, including the urban areas of Oudtshoorn, Bongulethu, Bridgton, Toekomsrus and the adjacent rural areas of Dysselsdorp, Calitzdorp, Uniondale, Ladismith and Zoar.

Subjects

Sixty-four mothers or caregivers to infants 6–12 months of age were included in the sample.

Results

Information obtained through the questionnaires supported what was said during discussions. Although perceived as important by the majority of respondents, some of the guidelines were not well understood without prior explanation. Such guidelines were those pertaining to meal frequency and cup feeding, while application of the guideline to prolonged breast-feeding seemed the most problematic.

Conclusions

The FBDGs for this age group will have to be supported by extensive and appropriate educational material to be effective when introduced to the public. The fact that the applicability of the guideline to prolonged breast-feeding seemed to be the most problematic is a cause for concern.

Non-DNA binding, dominant-negative, human PPARgamma mutations cause lipodystrophic insulin resistance

PPARgamma is essential for adipogenesis and metabolic homeostasis. We describe mutations in the DNA and ligand binding domains of human PPARgamma in lipodystrophic, severe insulin resistance. These receptor mutants lack DNA binding and transcriptional activity but can translocate to the nucleus, interact with PPARgamma coactivators and inhibit coexpressed wild-type receptor. Expression of PPARgamma target genes is markedly attenuated in mutation-containing versus receptor haploinsufficent primary cells, indicating that such dominant-negative inhibition operates in vivo. Our observations suggest that these mutants restrict wild-type PPARgamma action via a non-DNA binding, transcriptional interference mechanism, which may involve sequestration of functionally limiting coactivators.

Assessment of the quality of interaction in distance learning programmes utilising the Internet (WebCT) or interactive television (ITV)

INTRODUCTION

This study focuses on the quality of interaction in interactive TV (ITV), WebCT bulletin boards (BBs) and chat rooms (CRs) and addresses the question of how effectively new collaborative electronic technologies have been married with new pedagogical ideas to create effective learning for distance education students.

METHODS

Fifteen (out of 68) BB, 14 (out of 32) CR and 13 (out of 25) ITV conversations were randomly selected for coding using a modified exchange structure analysis. The roles that students and lecturers took in the conversations were determined from this.

RESULTS

The percentage of turns made by lecturers as opposed to students was 51% in CRs, 14% in BBs and 68% in ITV. The percentage of turns spent on actual coursework was 73% in CRs, 89% in BBs and 82% in ITV. Comparisons between tutors' and students' roles within as well as between ITV, BBs and CRs were all statistically significant with P < 0.05. In CRs the main roles of both students and lecturers were those of elaborators, inquirers and explainers. In BBs the main roles of students and lecturers were those of explainers and evaluators. In ITV sessions students' main roles were those of elaborators and explainers, whereas lecturers' main roles were those of lecturers, elaborators, inquirers and evaluators.

CONCLUSION

In terms of creating a constructivist and active learning community that can operate within a distance learning paradigm, WebCT appears superior to ITV.

A new mutation, R563Q, of the beta subunit of the epithelial sodium channel associated with low-renin, low-aldosterone hypertension

OBJECTIVE

To determine the relationship between R563Q, a mutation of the renal epithelial sodium channel, and hypertension.

METHODS

Hypertensive patients with low renin and aldosterone, hypokalemia or resistant hypertension were selected for DNA analysis. Genomic DNA encoding the C-terminal domain of the epithelial sodium channel beta subunit from hypertensives and controls was amplified by polymerase chain reaction and screened for the R563Q mutation by digestion with Sfc1 restriction enzyme, or sequenced.

RESULTS

A previously undescribed mutation, R563Q, of the beta epithelial sodium channel was found in 10 of 139 black hypertensives, but was not present in any of 103 black normotensives, a significant (P = 0.0058) difference in frequency. The frequency of the mutation in the subgroup of black low-renin, low-aldosterone hypertensives (four of 14) was significantly (P = 0.0001) greater than in normotensives, and was also greater (P = 0.041) than in normal-high renin hypertensives, suggesting that R563Q is an activating mutation of the epithelial sodium channel. R563Q was also found in seven out of 250 mixed ancestry hypertensives, and was significantly (P = 0.017) associated with low-renin, low-aldosterone hypertension in this population group. The mutation was found in one of 100 mixed ancestry normotensives but not in any of 136 white hypertensives. Of the 18 R563Q patients, 11 had severe hypertension, leading to renal failure in two cases, while only two had hypokalaemia.

CONCLUSIONS

R563Q, a new variant of the beta epithelial sodium channel, is associated with low-renin, low-aldosterone hypertension, in South African black and mixed-ancestry patients. Only a minority of individuals with the R563Q allelle fully express the Liddle's syndrome phenotype.

Novel evidence of a role for chromosome 1 pericentric heterochromatin in the pathogenesis of B-cell lymphoma and multiple myeloma

1q rearrangement is a remarkably frequent secondary chromosomal change in both non-Hodgkin's lymphoma (NHL) and multiple myeloma (MM), where it is associated with tumor progression. To gain insight into 1q rearrangement-associated disease mechanisms, we used fluorescence in situ hybridization (FISH) to search for recurring 1q breaks in 35 lymphoma samples (31 NHL patients and 4 lymphoma-derived cell lines) as well as 22 MM patients with cytogenetically determined 1q abnormalities. Strikingly, dual-color FISH analysis with chromosome 1 centromere and 1q12-specific probes identified constitutive heterochromatin band 1q12 as the single most frequent breakpoint site in both NHL and MM (39% and 89% of 1q breaks, respectively). These rearrangements consistently generated aberrant heterochromatin/euchromatin junctions and gain of 1q12 material. A further 30% of NHL 1q breaks specifically involved two other novel, closely spaced sites (clusters I and II) within a 2.5 Mb region of proximal 1q21 (D1S3620 to D1S3623). A possible association between these sites and NHL subtype was evident; the cluster I rearrangement was frequent in follicular and diffuse large cell lymphoma, whereas the cluster II rearrangement was more frequently observed in diffuse small-cell lymphoma (2/2 marginal zone lymphomas, 1/2 atypical chronic lymphocytic leukemias, and 1 lymphoplasmacytic lymphoma in this series). Candidate oncogenes bordering this interval (BCL9 and AF1Q) were not rearranged in any patient except one (AF1Q). This study provides the first evidence of involvement of 1q12 constitutive heterochromatin in the pathogenesis of NHL and MM and indicates proximal 1q21 to be of specific pathological significance in NHL.

Seroresponses to virus-like particles of human papillomavirus types 16, 18, 31, 33, and 45 in San people of Southern Africa

Virus-like particles (VLPs) of the high-risk human papillomavirus (HPV) types 16, 18, 31, 33, and 45 were used as antigen in enzyme-linked immunosorbent assay (ELISA) to determine the prevalence of serum IgG in a group of San people originally from Namibia, now residing in South Africa. The San children had low seroprevalence to all VLP types, but 26/115 (22.6%) of the children were seropositive to at least 1 VLP type. Among the adults, seroprevalence was significantly higher. The seroprevalence of antibodies in 101 San women to VLP-16 was 16.8%, VLP-18 18.8%, VLP-31 12.9%, VLP-33 17.8%, and VLP-45 22.8%. Five of the 11 men were seropositive: 2 for VLP-31, 1 for VLP-18, 1 for VLP-33, and 1 for VLP-45. Seroreactivity appeared to be type specific, except possibly to VLP-18 and -45. Of the adults, 50.5% were seropositive to at least 1 VLP type and 24.8% were seropositive to >1 VLP type. From this study, it is concluded that the San people are exposed to HPV-16, -18, -31, -33, and -45, with antibodies to VLP-45 being the most prevalent.

Evidence for incomplete replication of a penguin poxvirus in cells of mammalian origin

The recent discovery of a novel poxvirus [penguin-pox virus (PPV)] from Jackass penguins offers the potential of a unique candidate vaccine vector for use in mammals. Infectivity studies were therefore undertaken using a number of mammalian cell lines and chick embryo fibroblasts (CEF). It was shown that the simian CV-1 cell line was able to support replication of the PPV DNA, but no infectious progeny virus could be recovered from the infected cells. Electron microscopy was used to establish the extent of virus morphogenesis in CV-1 cells as compared to that in both chorio-allantoic membranes (CAMs) of hens' eggs and CEF cells. It appears that CV-1 cells are able to support partial maturation of PPV, but that morphogenesis does not proceed to the stage of mature infectious particles. Vaccinia virus promoters were successful in achieving transient gene expression in PPV-infected cells.

A novel Glu421Lys substitution in the lipoprotein lipase gene in pregnancy-induced hypertriglyceridemic pancreatitis

Severe hypertriglyceridemia is an uncommon pathological finding in pregnant women if there is no prior history of hyperlipidemia. A partial reduction in lipoprotein lipase (LPL) activity due to a mutation in the LPL gene, is often an associating factor. Here we report a novel LPL gene mutation (Glu421Lys), in a previously healthy primigravid woman who died from hypertriglyceridemia-induced pancreatitis during the last trimester of pregnancy. The patient was heterozygous for this mutation which a charge inversion in the C-terminal domain of LPL resulting in a moderate reduction in catalytic activity, both in vivo and in vitro. These data support the role of partial LPL deficiency in the pathogenesis of severe gestational hypertriglyceridemia.

Age distribution of antibodies to human papillomavirus in children, women with cervical intraepithelial neoplasia and blood donors from South Africa

Sera from 95 women with cervical intraepithelial neoplasia (CIN), 95 age-matched female blood donors, and 155 children aged between 1 and 12 years were tested by enzyme-linked immunosorbent assay (ELISA) for levels of serum IgG to three human papillomavirus (HPV) peptides (HPV-16 E2 [E2-16], HPV-18 E2 (E2-18], HPV-16 L1 [L1-16]), as well as HPV-16 virus-like particles (VLP-16) and bovine papillomavirus type 1 virus-like particles (BPV-VLP). In the adult group antibodies to E2-16 and VLP-16 were significantly associated with CIN when compared to the blood donor controls (P = .039 and P = .002, respectively). In women with CIN there was an increase in seropositivity to E2-16 and a decrease in seropositivity to VLP-16 with age. Antibodies to HPV-16 E2 could therefore be an important marker of CIN in women over 40 years of age, whereas antibodies to VLP-16 could be a marker for CIN in younger women. There was no correlation with CIN and antibodies to E2-18, L1-16, and BPV-VLP. In the children's sera antibodies were detected to E2-16 (44.5%), E2-18 (18.7%), L1-16 (20%), VLP-16 (4.5%), and BPV-VLP (5.1%). Between the ages of 3 and 12 years the prevalence of antibodies to E2-16 decreased with age. The presence of antibodies to HPV-16 in young children indicated infection with either HPV-16 or a related virus. HPV DNA isolation from children could help resolve this question.

Iron Deficiency Developing in Patients with Homozygous Hypercholesterolaemia on Long-term Plasmapheresis is Significantly Contributed to by Extracorporeal Haemolysis

Patients with homozygous hypeicholesterolaemia are notoriously refractory to pharmacologic intervention, leaving regular long-term plasmapheresis as one of the most effective forms of therapy. In this situation we noted the universal development of anaemia; accordingly, its pathogenesis was investigated in a stable cohort of patients over a two year period. Radionuclide studies were carried out in 8 of the 9 available individuals: of these 3 who were not on treatment and 3 out of 5 on the apheresis programme had mean red cell lifespan below the lower level of our normal range. The creation of an arterio-venous fistula and subsequent performance of plasma exchange procedures every two weeks was followed by a falling haemoglobin concentration and the appearance of hypochromasia and microcytosis. The latter was the result of substantial loss of iron through venesection, in the discard plasma and by a transient peak of the iron in the urine: the last two compartments were studied using inductively coupled plasma atomic emission spectrometry (ICP-AES). Such depletion could not be compensated for by a dietary intake of iron that barely met the recommended daily allowance whereas the anaemia reversed readily on oral supplementation. This is the first report of extracorporeal haemolysis in this clinical setting and recognition of its pathophysiology directly influences management. Thus, oral iron supplementation should prevent anaemia and its symptoms whilst also circumventing the paradoxical hyperviscosity that might otherwise occur from iron deficiency.

A new mutation destroying disulphide bridging in the C-terminal domain of lipoprotein lipase

Lipoprotein lipase (LPL) is one of two intravascular lipases involved in the lipolysis of the triglyceride core of circulating lipoproteins. The occurrence of patients with genetic deficiencies has provided insight into the structure and function relationships of this lipase. It is now known that LPL manifests a two domain structure with the N-terminal domain of greater structural and functional significance as it contains the active site and interfacial binding motifs. We report on a Cys418Tyr substitution in the C-terminal domain which disrupts the only disulphide bridge in the region and is associated with catalytic deficiency in post-heparin plasma. This result was unexpected as previous in vitro assessment of the functional significance of disulphide bridging had shown that while the 3, N-terminal disulphides were critical for enzyme function, loss of the only C-terminal disulphide minimally affected catalytic activity. We generated the Cys418Tyr mutant by site-directed mutagenesis and show that it manifests 48% of normal activity in vitro, while the companion variants, Cys438Ser and Cys418Ser-Cys438Ser, are less affected with activities at 76% and 78% of normal.

Influence of specific mutations at the LDL-receptor gene locus on the response to simvastatin therapy in Afrikaner patients with heterozygous familial hypercholesterolaemia

Simvastatin, an inhibitor of HMG CoA reductase, lowers the plasma total cholesterol and LDL-cholesterol concentration in familial hypercholesterolemic patients. The efficacy of the drug shows considerable inter-individual variation, however. In this study we have assessed the influence of certain LDL-receptor gene mutations on this variation. A group of 20 male and female heterozygotic familial hypercholesterolemic patients, all Afrikaners and each bearing one of two different LDL receptor gene mutations, FH Afrikaner-1 (FH1) and FH Afrikaner-2 (FH2), was treated with simvastatin (40 mg once daily) for 18 months. The average reduction in total plasma cholesterol was 35.3% in the case of the FH2 men but only 23.2% in that of the FH1 men (P = 0.005); the reduction in LDL cholesterol concentrations was also greater in the FH2 group (39% as opposed to 27.1%, P = 0.02). The better response of the FH2 group was also evident when men and women were considered together. Female FH1 patients responded better to simvastatin treatment, however, than did males with the same gene defect. Mutations at the LDL-receptor locus may thus play a significant role in the variable efficacy of the drug. The particular mutations in the males of this group may have contributed up to 35% of the variance in total cholesterol response and 29% of the variance in LDL-cholesterol response to simvastatin treatment.

Failure of magnesium supplementation to influence marathon running performance or recovery in magnesium-replete subjects

This study examined the effect of magnesium supplementation on muscle magnesium content, on running performance during a 42-km marathon footrace, and on muscle damage and the rate of recovery of muscle function following the race. Twenty athletes were divided equally into two matched groups and were studied for 4 weeks before and 6 weeks after a marathon in a double-blind trial; the experimental group received magnesium supplement (365 mg per day) and the control group, placebo. Magnesium supplementation did not increase either muscle or serum magnesium concentrations and had no measurable effect on 42-km marathon running performance. Extra magnesium ingestion also had no influence on the extent of muscle damage or the rate of recovery of muscle function. The latter was significantly reduced immediately after the marathon but returned to normal within 1 week. Thus, magnesium supplementation in magnesium-replete subjects did not enhance performance or increase resistance to muscle damage during the race, or the rate of recovery of muscle function following the race.

Immunological relevance of malonic dialdehyde. I. Preparation of Schiff's bases from lysozyme or polylysine reacted with malonic dialdehyde

Malonic dialdehyde (MDA) is produced in all mammalian tissues either as an end product of lipid peroxidation or as a by-product of arachidonic acid metabolism. It may either be quickly oxidized to carbon dioxide or combine covalently with primary amino groups of proteins, phospholipids or nucleic acids. In the latter case, fluorescent Schiff's bases with 1-amino-3-iminopropene (AIP) bridges are produced. MDA metabolism is now fairly well elucidated, while that of MDA-cross-linked biological molecules remains unknown. Aiming at investigating the fate of such cross-linked molecules in mammalian organisms, and their biological relevance, we tried in the present study to prepare reproducibly Schiff's bases from chicken egg white lysozyme reacted with MDA. The resulting mixture of different Schiff's bases (ML) was fractionated into single oligomeric fractions by gel-filtration chromatography. ML and the single oligomeric fractions obtained from this mixture were controlled by fluorescence measurements for their content of AIP bridges, and by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate (SDS-PAGE) for their content of different oligomers. ML contained monomers, dimers, trimers and other oligomers, as shown by SDS-PAGE. The corresponding single oligomeric fractions were satisfactorily separated by gel-filtration chromatography (purity better than 94%, as determined by SDS-PAGE). Schiff's bases from poly-L-lysine reacted with MDA (MP) were also prepared. Their fluorescence emission spectrum was similar to that of ML and to that of the single oligomeric fractions obtained from ML.