Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 60
Filter
1.
S Afr Med J ; 114(3): e1016, 2024 Mar 18.
Article in English | MEDLINE | ID: mdl-38525564
2.
S Afr Med J ; 113(7): 6-7, 2023 06 21.
Article in English | MEDLINE | ID: mdl-37882038
5.
S Afr Med J ; 108(11b): 973-1000, 2018 10 26.
Article in English | MEDLINE | ID: mdl-30421699

ABSTRACT

South Africa (SA) is home to a heterogeneous population with a wide range of cardiovascular risk factors. Cholesterol reduction in combination with aggressive management of modifiable risk factors, including nutrition, physical activity, blood pressure and smoking, can help to reduce and prevent morbidity and mortality in individuals who are at increased risk of cardiovascular events. This updated consensus guide to management of dyslipidaemia in SA is based on the updated European Society of Cardiology and European Atherosclerosis Society dyslipidaemia guidelines published in 2016. For individuals who are not considered to be at high or very high cardiovascular risk, the decision whether to treat and which interventional strategy to use is based on a cardiovascular risk score calculated using total cholesterol, high-density lipoprotein cholesterol (HDL-C), gender, age and smoking status. The cardiovascular risk score refers to the 10-year risk of any cardiovascular event and includes 4 categories of risk (low, moderate, high and very high). People with established cardiovascular disease, diabetes mellitus, chronic kidney disease and genetic or severe dyslipidaemias are considered to already be at high or very high risk and do not require risk scoring. Therapeutic lifestyle change is the mainstay of management for all patients. The need for and intensity of drug therapy is determined according to baseline low-density lipoprotein (LDL-C) levels and the target LDL-C concentration appropriate to the individual. LDL-C treatment targets are based on pre-treatment risk and are as follows: <3 mmol/L in low- and moderate risk cases; <2.5 mmol/L and a reduction of at least 50% if the baseline concentration is 2.5 - 5.2 mmol/L in high-risk cases; and <1.8 mmol/L and a reduction of at least 50% if the baseline concentration is 1.8 - 3.5 mmol/L in very high-risk cases. A statin is usually recommended first-line; the specific agent is based on the required degree of cholesterol reduction, comorbidities and co-prescribed medication. Special attention should be paid to children with a family history of genetic or severe dyslipidaemia, who should be screened for dyslipidaemia from 8 years of age. In SA, HIV infection is not considered to be a significant cardiovascular risk factor and treatment recommendations for HIV-positive individuals are the same as for the general population, with careful choice of pharmacotherapy to avoid potential adverse drug-drug interactions. The benefit of statins in individuals older than 70 years is uncertain and clinical judgement should be used to guide treatment decisions and to avoid side-effects and overmedication in this group.


Subject(s)
Cardiovascular Diseases , Dyslipidemias , Hydroxymethylglutaryl-CoA Reductase Inhibitors , Mass Screening/methods , Patient Care Management , Risk Reduction Behavior , Cardiovascular Diseases/epidemiology , Cardiovascular Diseases/prevention & control , Cardiovascular Diseases/psychology , Cholesterol, HDL/blood , Cholesterol, LDL/blood , Consensus , Dyslipidemias/blood , Dyslipidemias/epidemiology , Dyslipidemias/therapy , Humans , Hydroxymethylglutaryl-CoA Reductase Inhibitors/administration & dosage , Hydroxymethylglutaryl-CoA Reductase Inhibitors/adverse effects , Patient Care Management/methods , Patient Care Management/standards , Risk Assessment/methods , Risk Factors , South Africa
6.
Cephalalgia ; 37(8): 737-755, 2017 Jul.
Article in English | MEDLINE | ID: mdl-27226003

ABSTRACT

Background Familial hemiplegic migraine (FHM) is a rare monogenic migraine subtype characterised by attacks associated with transient motor weakness. Clinical information is mainly based on reports of small families with only short follow-up. Here, we document a prospective 15-year follow-up of an extended family with FHM type 2. Patients and methods After diagnosing FHM in a patient with severe attacks associated with coma and fever, we identified eight more family members with FHM and one with possible FHM. All family members were prospectively followed for 15 years. In total 13 clinically affected and 21 clinically non-affected family members were genetically tested and repeatedly investigated. Results A novel p.Arg348Pro ATP1A2 mutation was found in 14 family members: 12 with clinical FHM, one with psychomotor retardation and possible FHM, and one without FHM features. In 9/12 (75%) family members with genetically confirmed FHM, attacks were severe, long-lasting, and often associated with impaired consciousness and fever. Such attacks were frequently misdiagnosed and treated as viral meningitis or stroke. Epilepsy was reported in three family members with FHM and in the one with psychomotor retardation and possible FHM. Ataxia was not observed. Conclusion FHM should be considered in patients with recurrent coma and fever.


Subject(s)
Migraine with Aura/genetics , Sodium-Potassium-Exchanging ATPase/genetics , Coma/genetics , Female , Fever/genetics , Follow-Up Studies , Humans , Male , Migraine with Aura/complications , Mutation , Pedigree , Prospective Studies
7.
Horm Metab Res ; 48(12): 814-821, 2016 Dec.
Article in English | MEDLINE | ID: mdl-27813051

ABSTRACT

Salivary cortisol has been used to monitor hydrocortisone replacement in patients with Addison's disease (AD). Since salivary cortisol is metabolised to salivary cortisone, it may be an adjunctive analyte to assess adequacy of hydrocortisone replacement in patients with AD. We aimed to characterise the exposure of salivary cortisol and cortisone in patients and healthy controls. We measured salivary cortisol and cortisone by liquid chromatography-tandem mass spectrometry and constructed a day curve (08:00 until 24:00 h) with 16 time points in 25 AD patients taking their usual hydrocortisone dose and in 26 healthy controls. The median (interquartile range) area under the curve (AUC) for cortisol was not different for patients, compared with controls [55.63 (32.91-151.07) nmol*min*l-1 vs. 37.49 (27.41-52.00) nmol*min*l-1; p=0.098, respectively], whereas the peak cortisol Cmax was higher in patients [32.61 (5.75-146.19) nmol/l vs. 8.96 (6.96-12.23) nmol/l; p=0.013], compared with controls. The AUC for cortisone [23.65 (6.10-54.76) nmol*min*l-1 vs. 227.73 (200.10-280.52) nmol*min*l-1; p≤ 0.001, respectively], and peak cortisone Cmax was lower in patients than in controls [11.11 (2.91-35.85) nmol/l vs. 33.12 (25.97-39.95) nmol/l; p=0.002]. The AUC for salivary cortisol and salivary cortisone were not correlated with any measures of hydrocortisone dose. The time-course and AUC of salivary cortisol were similar between Addison's patients and healthy controls. Patients had substantially lower salivary cortisone AUC, compared to healthy controls. Salivary cortisol AUC and pharmacokinetics were not related to hydrocortisone dose and thus are not likely useful markers for the adequacy of hydrocortisone replacement.


Subject(s)
Addison Disease/drug therapy , Cortisone/metabolism , Hormone Replacement Therapy , Hydrocortisone/metabolism , Hydrocortisone/therapeutic use , Saliva/metabolism , Adult , Biomarkers/metabolism , Case-Control Studies , Cortisone/pharmacokinetics , Female , Humans , Male , Middle Aged , Time Factors , Young Adult
8.
Atherosclerosis ; 240(2): 408-14, 2015 Jun.
Article in English | MEDLINE | ID: mdl-25897792

ABSTRACT

OBJECTIVE: Lomitapide (a microsomal triglyceride transfer protein inhibitor) is an adjunctive treatment for homozygous familial hypercholesterolaemia (HoFH), a rare genetic condition characterised by elevated low-density lipoprotein-cholesterol (LDL-C), and premature, severe, accelerated atherosclerosis. Standard of care for HoFH includes lipid-lowering drugs and lipoprotein apheresis. We conducted a post-hoc analysis using data from a Phase 3 study to assess whether concomitant apheresis affected the lipid-lowering efficacy of lomitapide. METHODS: Existing lipid-lowering therapy, including apheresis, was to remain stable from Week -6 to Week 26. Lomitapide dose was escalated on the basis of individual safety/tolerability from 5 mg to 60 mg a day (maximum). The primary endpoint was mean percent change in LDL-C from baseline to Week 26 (efficacy phase), after which patients remained on lomitapide through Week 78 for safety assessment and further evaluation of efficacy. During this latter period, apheresis could be adjusted. We analysed the impact of apheresis on LDL-C reductions in patients receiving lomitapide. RESULTS: Of the 29 patients that entered the efficacy phase, 18 (62%) were receiving apheresis at baseline. Twenty-three patients (13 receiving apheresis) completed the Week 26 evaluation. Of the six patients who discontinued in the first 26 weeks, five were receiving apheresis. There were no significant differences in percent change from baseline of LDL-C at Week 26 in patients treated (-48%) and not treated (-55%) with apheresis (p = 0.545). Changes in Lp(a) levels were modest and not different between groups (p = 0.436). CONCLUSION: The LDL-C lowering efficacy of lomitapide is unaffected by lipoprotein apheresis.


Subject(s)
Anticholesteremic Agents/administration & dosage , Benzimidazoles/administration & dosage , Blood Component Removal/methods , Cholesterol, LDL/blood , Homozygote , Hyperlipoproteinemia Type II/therapy , Adult , Anticholesteremic Agents/adverse effects , Benzimidazoles/adverse effects , Biomarkers/blood , Blood Component Removal/adverse effects , Combined Modality Therapy , Female , Genetic Predisposition to Disease , Humans , Hyperlipoproteinemia Type II/blood , Hyperlipoproteinemia Type II/diagnosis , Hyperlipoproteinemia Type II/genetics , Lipoprotein(a)/blood , Male , Phenotype , Time Factors , Treatment Outcome , Young Adult
9.
Horm Metab Res ; 46(10): 691-6, 2014 Sep.
Article in English | MEDLINE | ID: mdl-24799025

ABSTRACT

Hypogonadism may complicate Addison's disease (primary hypoadrenalism), but prevalence and metabolic sequelae of hypogonadism in Addison's disease are poorly described. We recruited patients from the South African Addison's disease national registry who received stable replacement doses of hydrocortisone and had no acute illness. Male biochemical testosterone deficiency was defined as an early morning basal testosterone<9.9 nmol/l and premature ovarian failure (POF) when menopause occurred before 40 years of age. Cardiometabolic risk variables were measured in males only. Male hypogonadism prevalence was 33% (14/42), and 10 patients had newly diagnosed hypogonadism. Two untreated patients had elevated FSH or LH (>10 or 12 IU/l). Testosterone deficiency did not correlate with age, disease duration or hydrocortisone dose. Untreated male hypogonadal subjects had a higher (mean ± standard deviation) BMI compared to eugonadal subjects 29.2 ± 4.9 kg/m(2) vs. 24.7 ± 3.4 kg/m(2) (p=0.01) and a higher median (interquartile range) high-sensitive-CRP 6.4 (2.5-14.0) mg/l vs. 1.45 (0.6-2.8) mg/l (p=0.002). There were no differences between the 2 groups in lipids, lipoproteins and fasting glucose. The median (interquartile range) DHEAS was lower in the hypogonadal 0.31 (0.27-0.37) µmol/l, compared with the eugonadal group 0.75 (0.50-1.51) µmol/l (p=0.005). POF was documented in 11% of female patients. Male testosterone deficiency was highly prevalent in this cohort and was primarily due to secondary hypogonadism. Only BMI and hs-CRP were increased in untreated male hypogonadal subjects. Male and female hypogonadism appears to be a common complication of Addison's disease and may contribute to its morbidity.


Subject(s)
Addison Disease/complications , Hypogonadism/epidemiology , Hypogonadism/etiology , Addison Disease/blood , Adult , Aged , C-Reactive Protein/metabolism , Cohort Studies , Female , Follicle Stimulating Hormone/blood , Humans , Hypogonadism/blood , Luteinizing Hormone/blood , Male , Middle Aged , South Africa/epidemiology , Testosterone/blood
10.
Clin Exp Rheumatol ; 32(3): 308-14, 2014.
Article in English | MEDLINE | ID: mdl-24708914

ABSTRACT

OBJECTIVES: Health care and vocational professionals regularly encounter patients with rheumatic diseases who are embittered after a disability pension examination. People who are embittered typically feel victimised, experience resentment and injustice, resist help, and have difficulty coping. Our objective was to examine the occurrence of embitterment in patients with rheumatic diseases after a disability pension examination and the association of embitterment with its possible determinants helplessness and illness invalidation at work. METHODS: The Illness Cognition Questionnaire (ICQ), Illness Invalidation Inventory (3*I), and Bern Embitterment Inventory were completed by patients who had 9 to 12 weeks earlier received the result of a disability pension examination. Diagnoses were fibromyalgia (n=103), rheumatoid arthritis (n=46), osteoarthritis (n=158), another rheumatic disease (n=62), and more than one rheumatic disease (n=187). Scores were compared to scores of reference groups. Hierarchical regression analyses were conducted. RESULTS: Eighteen to 27 percent of patients had high levels of embitterment with no differences between diagnostic groups (p=0.71). Helplessness (p<0.001), the two invalidation dimensions discounting and lack of understanding (p<0.001), and the combination of helplessness with these invalidation dimensions (p<0.01), were predictive of more embitterment. CONCLUSIONS: Our results suggest that, after a disability pension examination, embitterment is present in about one out of five patients with a rheumatic disease. This is problematic insofar as embitterment limits well-being, functioning, and the potential to reintegrate to work. To the extent that helplessness and invalidation at work are causal determinants of embitterment, interventions targeting these aspects may be key to reduce embitterment.


Subject(s)
Hostility , Insurance, Disability , Musculoskeletal Diseases/psychology , Rheumatic Diseases/psychology , Workers' Compensation , Adult , Female , Helplessness, Learned , Humans , Male , Middle Aged , Musculoskeletal Diseases/economics , Pensions , Rheumatic Diseases/economics , Social Support , Surveys and Questionnaires
11.
Crit Rev Clin Lab Sci ; 51(1): 46-62, 2014 Feb.
Article in English | MEDLINE | ID: mdl-24405372

ABSTRACT

Atherosclerosis is strongly associated with dyslipoproteinaemia, and especially with increasing concentrations of low-density lipoprotein and decreasing concentrations of high-density lipoproteins. Its association with increasing concentrations of plasma triglyceride is less clear but, within the mixed hyperlipidaemias, dysbetalipoproteinaemia (Fredrickson type III hyperlipidaemia) has been identified as a very atherogenic entity associated with both premature ischaemic heart disease and peripheral arterial disease. Dysbetalipoproteinaemia is characterized by the accumulation of remnants of chylomicrons and of very low-density lipoproteins. The onset occurs after childhood and usually requires an additional metabolic stressor. In women, onset is typically delayed until menopause. Clinical manifestations may vary from no physical signs to severe cutaneous and tendinous xanthomata, atherosclerosis of coronary and peripheral arteries, and pancreatitis when severe hypertriglyceridaemia is present. Rarely, mutations in apolipoprotein E are associated with lipoprotein glomerulopathy, a condition characterized by progressive proteinuria and renal failure with varying degrees of plasma remnant accumulation. Interestingly, predisposing genetic causes paradoxically result in lower than average cholesterol concentration for most affected persons, but severe dyslipidaemia develops in a minority of patients. The disorder stems from dysfunctional apolipoprotein E in which mutations result in impaired binding to low-density lipoprotein (LDL) receptors and/or heparin sulphate proteoglycans. Apolipoprotein E deficiency may cause a similar phenotype. Making a diagnosis of dysbetalipoproteinaemia aids in assessing cardiovascular risk correctly and allows for genetic counseling. However, the diagnostic work-up may present some challenges. Diagnosis of dysbetalipoproteinaemia should be considered in mixed hyperlipidaemias for which the apolipoprotein B concentration is relatively low in relation to the total cholesterol concentration or when there is significant disparity between the calculated LDL and directly measured LDL cholesterol concentrations. Genetic tests are informative in predicting the risk of developing the disease phenotype and are diagnostic only in the context of hyperlipidaemia. Specialised lipoprotein studies in reference laboratory centres can also assist in diagnosis. Fibrates and statins, or even combination treatment, may be required to control the dyslipidaemia.


Subject(s)
Apolipoproteins E/genetics , Hyperlipoproteinemia Type III , Humans , Mutation
12.
Eur J Endocrinol ; 168(3): 403-12, 2013 Mar.
Article in English | MEDLINE | ID: mdl-23239757

ABSTRACT

BACKGROUND: Uncertainty exists whether glucocorticoid receptor (GCR) polymorphisms play a role in steroid-related side effects in Addison's disease (AD) patients on hydrocortisone. The polymorphisms Bcll and N363S appear to increase sensitivity to cortisol, while the ER22/23EK polymorphism has been associated with resistance to cortisol. METHOD: One hundred and forty seven AD patients, and gender, and ethnicity-matched controls were recruited in South Africa. Three polymorphisms in the GCR were studied, using PCR followed by restriction fragment length analysis. Associations with BMI, lipids, glucose and inflammatory markers were investigated. RESULTS: In both patients and controls, the Bcll polymorphism occurred more frequently in whites than in other ethnic groups studied but was not associated with any of the metabolic parameters tested. The ER22/23EK polymorphism was associated with an increased BMI in both patients (29.4 vs 24.7  kg/m²) and control subjects (26.3 vs 24.2  kg/m²). The ER22/23EK polymorphism was also associated with lower LDL cholesterol in control subjects (3.46 vs 3.93  mmol/l) and in patients (3.52 vs 4.10  mmol/l). N363S was associated with increased BMI in controls 29.9  kg/m² vs wild type 24.8  kg/m². Median hydrocortisone doses were greater in patients heterozygous for either ER22/23EK 30.0  mg or N363S 25.0  mg polymorphisms than in wild type patients 20.0  mg (both comparisons). CONCLUSION: Alterations in lipids, BMI and hydrocortisone dose were associated with two polymorphisms. Further larger studies are warranted to corroborate these findings.


Subject(s)
Addison Disease/genetics , Addison Disease/physiopathology , Drug Resistance , Hyperlipidemias/etiology , Overweight/complications , Polymorphism, Genetic , Receptors, Glucocorticoid/genetics , Addison Disease/complications , Addison Disease/drug therapy , Adult , Body Mass Index , Cohort Studies , Dose-Response Relationship, Drug , Female , Genetic Association Studies , Glucocorticoids/administration & dosage , Glucocorticoids/adverse effects , Glucocorticoids/therapeutic use , Hormone Replacement Therapy/adverse effects , Humans , Hydrocortisone/administration & dosage , Hydrocortisone/adverse effects , Hydrocortisone/therapeutic use , Hyperlipidemias/epidemiology , Male , Middle Aged , Receptors, Glucocorticoid/metabolism , Risk Factors , South Africa/epidemiology
13.
Cardiovasc J Afr ; 22(5): 234-40, 2011.
Article in English | MEDLINE | ID: mdl-21922121

ABSTRACT

AIM: The aim of the CEntralised Pan-South African survey on tHE Under-treatment of hypercholeSterolaemia (CEPHEUS SA) was to evaluate the current use and efficacy of lipidlowering drugs (LLDs), and to identify possible patient and physician characteristics associated with failure, if any, to achieve low-density lipoprotein cholesterol (LDL-C) targets. METHODS: The survey was conducted in 69 study centres in South Africa and recruited consecutive consenting patients who had been prescribed LLDs for at least three months. One visit was scheduled for data collection, including fasting plasma lipid and glucose levels. Physicians and patients completed questionnaires regarding their knowledge, awareness and perceptions of hypercholesterolaemia and the treatment thereof. RESULTS: Of the 3 001 patients recruited, 2 996 were included in the final analyses. The mean age was 59.4 years, and 47.5% were female. Only 60.5 and 52.3% of patients on LLDs for at least three months achieved the LDL-C target recommended by the NCEP ATP III/2004 updated NCEP ATP III and the Fourth JETF/South African guidelines, respectively. Being male, older than 40 years, falling into the lower-risk categories, compliance with the medication regimen, and patient knowledge that the LDL-C goal had been reached, were associated with the highest probability of attaining LDL-C goals. CONCLUSION: The results of this survey highlight the sub-optimal lipid control achieved in many South African patients taking lipid-lowering therapy.


Subject(s)
Anticholesteremic Agents/therapeutic use , Health Knowledge, Attitudes, Practice , Hypercholesterolemia/drug therapy , Practice Patterns, Physicians' , Aged , Attitude of Health Personnel , Awareness , Biomarkers/blood , Cholesterol, LDL/blood , Drug Utilization , Female , Guideline Adherence , Health Care Surveys , Humans , Hypercholesterolemia/blood , Hypercholesterolemia/epidemiology , Logistic Models , Male , Medication Adherence , Middle Aged , Odds Ratio , Patient Education as Topic , Perception , Practice Guidelines as Topic , Practice Patterns, Physicians'/statistics & numerical data , South Africa/epidemiology , Surveys and Questionnaires , Time Factors , Treatment Outcome
14.
Environ Microbiol ; 13(11): 3047-58, 2011 Nov.
Article in English | MEDLINE | ID: mdl-21933319

ABSTRACT

Recent studies have suggested that bacterial volatiles play an important role in bacterial-plant interactions. However, few reports of bacterial species that produce plant growth modulating volatiles have been published, raising the question whether this is just an anecdotal phenomenon. To address this question, we performed a large screen of strains originating from the soil for volatile-mediated effects on Arabidopsis thaliana. All of the 42 strains tested showed significant volatile-mediated plant growth modulation, with effects ranging from plant death to a sixfold increase in plant biomass. The effects of bacterial volatiles were highly dependent on the cultivation medium and the inoculum quantity. GC-MS analysis of the tested strains revealed over 130 bacterial volatile compounds. Indole, 1-hexanol and pentadecane were selected for further studies because they appeared to promote plant growth. None of these compounds triggered a typical defence response, using production of ethylene and of reactive oxygen species (ROS) as read-outs. However, when plants were challenged with the flg-22 epitope of bacterial flagellin, a prototypical elicitor of defence responses, additional exposure to the volatiles reduced the flg-22-induced production of ethylene and ROS in a dose-dependent manner, suggesting that bacterial volatiles may act as effectors to inhibit the plant's defence response.


Subject(s)
Arabidopsis/microbiology , Bacteria/chemistry , Rhizosphere , Soil Microbiology , Volatile Organic Compounds/pharmacology , Alkanes/chemistry , Arabidopsis/drug effects , Arabidopsis/growth & development , Culture Media , Ethylenes/metabolism , Gas Chromatography-Mass Spectrometry , Hexanols/chemistry , Indoles/chemistry , Plant Growth Regulators/pharmacology , Reactive Oxygen Species/metabolism
15.
Int J Obes (Lond) ; 35(4): 605-17, 2011 Apr.
Article in English | MEDLINE | ID: mdl-20733586

ABSTRACT

OBJECTIVE: The gene TSPAN8 was recently identified in a genome-wide association study as the most likely causal gene in a locus that was correlated with the risk of type 2 diabetes (T2D) in northern European individuals. To assess whether Tspan8 is the actual T2D-causal gene in this locus, we ablated its expression in mice and determined the consequences of this ablation on a multitude of metabolic traits. RESULTS: We found that genetic ablation of Tspan8 in mice results in a reduction (-15.6%) in the body weight of males fed a normal chow diet and that this deficiency results in a resistance to body weight gain (-13.7%) upon feeding a high fat and high carbohydrate diet. The differences in body weight could only be detected in male mice and were the consequence of both a decrease in fat deposition, and a decrease in lean body mass (16.9 and 11%, respectively). In spite of the significant body weight difference, no changes in fasting insulin and glucose levels could be detected in Tspan8 knockout mice, nor could we identify changes in the clearance of glucose or sensitivity to insulin in oral glucose tolerance test and intraperitoneal insulin sensitivity test studies, respectively. In addition, male Tspan8 knockout mice showed significantly lower bone mineral density and phosphorus levels (6.2 and 16.6%, respectively). Expression of Tspan8 in mouse was highest in digestive tissues, but virtually absent from the pancreas. In contrast, expression of human TSPAN8 was substantial in digestive tissues, as well as pancreatic cells. CONCLUSIONS: Our results argue for a role for Tspan8 in body-weight regulation in males, but do not show differences in T2D-associated traits that were anticipated from previous human genome-wide association studies. Differences in Tspan8 expression levels in mouse and human tissues suggest that Tspan8 could fulfill different or additional physiological functions in these organisms.


Subject(s)
Diabetes Mellitus, Type 2/metabolism , Insulin Resistance/physiology , Membrane Glycoproteins/deficiency , Obesity/metabolism , Animals , Antigens, Neoplasm/genetics , Body Weight/physiology , Diabetes Mellitus, Type 2/genetics , Female , Genome-Wide Association Study , Insulin Resistance/genetics , Male , Membrane Glycoproteins/genetics , Mice , Mice, Inbred C57BL , Mice, Knockout , Obesity/genetics , Sex Factors , Tetraspanins
16.
ACS Nano ; 3(9): 2841-53, 2009 Sep 22.
Article in English | MEDLINE | ID: mdl-19658423

ABSTRACT

Cobalt core/platinum shell nanoparticles were prepared by the electroless deposition (ED) of Pt on carbon-supported cobalt catalyst (Co/C) and verified by HRTEM images. For a 2.0 wt % Co/C core, the ED technique permitted the Pt loading to be adjusted to obtain a series of bimetallic compositions with varying numbers of monolayers (ML). The tendency for corrosion of Co and the electrochemical (i.e., oxygen reduction reaction (ORR)) activity of the structures were measured. The results from temperature-programmed reduction (TPR) analysis suggest that a single Pt ML coverage is formed at a Pt weight loading between 0.5 and 0.7% on the 2.0% Co/C. HRTEM analysis indicates that the continuity of the Pt shell on the Co core depends on the precursor Co particle size, where "large" Co particles (>10 nm) favor noncontinuous, three-dimensional Pt structures and "small" Co particles (<6 nm) favor layer-by-layer growth. For these larger core-shell particles, Co was observed to quickly corrode in 0.3 M H(2)SO(4). Surface area specific ORR activity, measured by chemisorption techniques, revealed that the Pt-Co/C catalysts performed better than a commercial Pt/C catalyst; however, on a Pt mass basis, only the lower Pt:Co atomic ratio Pt-Co/C catalysts outperformed the Pt/C catalyst.

17.
J Hosp Infect ; 71(2): 123-31, 2009 Feb.
Article in English | MEDLINE | ID: mdl-19108932

ABSTRACT

It is not clear whether improvement in environmental decontamination is more efficiently achieved through changes in cleaning products, cleaning procedures, or performance of cleaning personnel. To assess the impact of cleaning performance on environmental contamination with vancomycin-resistant enterococci (VRE), we conducted a sequential trial in which a multifaceted environmental cleaning improvement intervention was introduced in a medical intensive care unit and respiratory step-down unit. The intervention included educational lectures for housekeepers and an observational programme of their activities without changes in cleaning products or written procedures. Following these interventions, the proportion of environmental sites cleaned improved from 49% to 85% (P<0.001); contamination of environmental sites declined from 21% to 8% (P<0.0001) before cleaning and from 13% to 8% (P<0.0001) after cleaning. The improved cleaning and contamination rates persisted in a washout period. In a multivariate model, cleaning thoroughness strongly influenced the degree of environmental contamination, with a 6% decline in VRE prevalence with every 10% increase in percentage of sites cleaned. These findings suggest that surface contamination with VRE is due to a failure to clean rather than to a faulty cleaning procedure or product.


Subject(s)
Decontamination/methods , Equipment Contamination/prevention & control , Fomites/microbiology , Housekeeping, Hospital/methods , Infection Control/methods , Vancomycin Resistance , Decontamination/standards , Disinfectants , Enterococcus/drug effects , Enterococcus/isolation & purification , Housekeeping, Hospital/standards , Humans , Intensive Care Units
18.
S Afr Med J ; 98(2): 105-8, 2008 Feb.
Article in English | MEDLINE | ID: mdl-18350203

ABSTRACT

Lipoprotein lipase deficiency causes severe hypertriglyceridaemia due to chylomicronaemia, and leads to recurrent and potentially life-threatening pancreatitis. This disorder can only be managed by dietary fat restriction as drugs are ineffective. We review the experience with familial chylomicronaemia in patients who attended the lipid clinics at Groote Schuur Hospital and Red Cross Children's War Memorial Hospital in Cape Town. Criteria for inclusion were an initial plasma triglyceride concentration of >15 mmol/l and a typical type I Fredrickson hyperlipidaemia pattern on plasma lipoprotein electrophoresis. A total of 29 patients were seen over 25 years. The mean age of presentation was 10 years, but ranged from 0 to 43 years. The modes of presentation differed: pancreatitis (N=16), eruptive xanthomata (N=2), coincidental detection of hypertriglyceridaemia (N=2), screening relatives (N=7), and after death from pancreatitis (N=1). Plasma triglycerides responded rapidly and dramatically to dietary fat restriction, and some patients sustained good control of the hyperlipidaemia. The onset of pancreatitis was earlier in patients of Indian ancestry, suggesting a genotype/phenotype interaction within this disorder. Genetic work-up indicated founder effects in the Afrikaner and Indian patients. Lipaemic plasma should be taken seriously at all ages, and necessitates work-up at specialised clinics where the diagnosis of chylomicronaemia or type I hyperlipidaemia facilitates appropriate dietary management that can prevent pancreatitis.


Subject(s)
Hyperlipoproteinemia Type I/complications , Hyperlipoproteinemia Type I/epidemiology , Hypertriglyceridemia/epidemiology , Hypertriglyceridemia/etiology , Adolescent , Adult , Child , Child, Preschool , Diet, Fat-Restricted , Female , Founder Effect , Humans , Hypertriglyceridemia/therapy , Incidental Findings , Infant , Infant, Newborn , Male , Mass Screening , Mutation , Pancreatitis/epidemiology , Pancreatitis/etiology , Racial Groups , South Africa/epidemiology , Xanthomatosis/epidemiology , Xanthomatosis/etiology
19.
Appl Environ Microbiol ; 74(5): 1376-84, 2008 Mar.
Article in English | MEDLINE | ID: mdl-18192425

ABSTRACT

The actinobacterium Kineococcus radiotolerans is highly resistant to ionizing radiation, desiccation, and oxidative stress, though the underlying biochemical mechanisms are unknown. The purpose of this study was to explore a possible linkage between the uptake of transition metals and extreme resistance to ionizing radiation and oxidative stress. The effects of six different divalent cationic metals on growth were examined in the absence of ionizing radiation. None of the metals tested were stimulatory, though cobalt was inhibitory to growth. In contrast, copper supplementation dramatically increased colony formation during chronic irradiation. K. radiotolerans exhibited specific uptake and intracellular accumulation of copper, compared to only a weak response to both iron and manganese supplementation. Copper accumulation sensitized cells to hydrogen peroxide. Acute-irradiation-induced DNA damage levels were similar in the copper-loaded culture and the age-synchronized no-copper control culture, though low-molecular-weight DNA was more persistent during postirradiation recovery in the Cu-loaded culture. Still, the estimated times for genome restoration differed by only 2 h between treatments. While we cannot discount the possibility that copper fulfills an unexpectedly important biochemical role in a low-radioactivity environment, K. radiotolerans has a high capacity for intracellular copper sequestration and presumably efficiently coordinated oxidative stress defenses and detoxification systems, which confers cross-protection from the damaging effects of ionizing radiation.


Subject(s)
Actinomycetales/growth & development , Actinomycetales/metabolism , Actinomycetales/radiation effects , Copper/pharmacokinetics , DNA Repair/radiation effects , Gamma Rays , Actinomycetales/ultrastructure , Electrophoresis, Gel, Pulsed-Field , Mass Spectrometry , Microscopy, Electron , Oxidative Stress/radiation effects
20.
SAMJ, S. Afr. med. j ; 98(2): 105-108, 2008.
Article in English | AIM (Africa) | ID: biblio-1271394

ABSTRACT

Lipoprotein lipase deficiency causes severe hypertriglyceridaemia due to chylomicronaemia and leads to recurrent and potentially life-threatening pancreatitis. This disorder can only be managed by dietary fat restriction as drugs are ineffective.We review the experience with familial chylomicronaemia in patients who attended the lipid clinics at Groote Schuur Hospital and the Red Cross Children's War Memorial Hospital in Cape Town. The criteria for inclusion were an initial plasma triglyceride concentration of 15 mmol/L and a typical type I Fredrickson hyperlipidaemia pattern on plasma lipoprotein electrophoresis. A total of 29 patients were seen over 25 years. The mean age of presentation was 10 years; but ranged from from 0 to 43 years. The modes of presentation differed: pancreatitis (n=16); eruptive xanthomata (n=2); coincidental detection of hypertriglyceridaemia (n=2); screening relatives (n=7) and after death from pancreatitis (n=1). Plasma triglycerides responded rapidly and dramatically to dietary fat restriction and some patients sustained good control of the hyperlipidaemia.. The onset of pancreatitis was earlier in patients of Indian ancestry suggesting a genotype/phenotype interaction within this disorder. Genetic work-up indicated founder effects in the Afrikaner and Indian patients. Lipaemic plasma should be taken seriously at all ages and necessitates work-up at specialised clinics where the diagnosis of chylomicronaemia or type I hyperlipidaemia facilitates appropriate dietary management that can prevent pancreatitis


Subject(s)
Chylomicrons , Hyperlipoproteinemia Type IV/adverse effects , Lipoprotein Lipase
SELECTION OF CITATIONS
SEARCH DETAIL
...