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1.
JACS Au ; 3(2): 526-535, 2023 Feb 27.
Article in English | MEDLINE | ID: mdl-36873699

ABSTRACT

The Angstrom-scale space between graphene and its substrate provides an attractive playground for scientific exploration and can lead to breakthrough applications. Here, we report the energetics and kinetics of hydrogen electrosorption on a graphene-covered Pt(111) electrode using electrochemical experiments, in situ spectroscopy, and density functional theory calculations. The graphene overlayer influences the hydrogen adsorption on Pt(111) by shielding the ions from the interface and weakening the Pt-H bond energy. Analysis of the proton permeation resistance with controlled graphene defect density proves that the domain boundary defects and point defects are the pathways for proton permeation in the graphene layer, in agreement with density functional theory (DFT) calculations of the lowest energy proton permeation pathways. Although graphene blocks the interaction of anions with the Pt(111) surfaces, anions do adsorb near the defects: the rate constant for hydrogen permeation is sensitively dependent on anion identity and concentration.

2.
Nutr Metab Cardiovasc Dis ; 29(10): 1003-1008, 2019 10.
Article in English | MEDLINE | ID: mdl-31400826

ABSTRACT

For almost a century, the scientific community is aware of the J-shaped curve between alcohol consumption and all-cause mortality. Moderate drinkers seem to live longer than both abstainers and heavy drinkers. These epidemiological observations regarding moderate alcohol consumption and beneficial health effects have been incessantly scrutinised for confounding and bias. This viewpoint discusses previous and recent criticisms regarding the J-shaped curve between alcohol consumption and total mortality risk. The controversies regarding the J-shaped curve between alcohol consumption and mortality are ongoing, as well as the debate among scientists in this area of research, resulting in conflicting messages in media and in different alcohol guidelines. Although it appears quite difficult to come up with a position statement only based on the currently available scientific data, it is imperative to fairly inform the public, without creating confusion and, worst case, disbelief in science.


Subject(s)
Alcohol Drinking/epidemiology , Evidence-Based Medicine , Alcohol Drinking/adverse effects , Alcohol Drinking/mortality , Cause of Death , Confounding Factors, Epidemiologic , Humans , Protective Factors , Risk Assessment , Risk Factors , Selection Bias
3.
Article in English | MEDLINE | ID: mdl-26245599

ABSTRACT

BACKGROUND: Osteoarthritis (OA) is a chronic condition. Nonsteroidal anti-inflammatory drugs recommended for treatment have serious adverse effects. A compelling body of anecdotal evidence alerted the authors to the therapeutic potential of dietary supplementation with Multiforce® (MF) Alkaline Powder for relief of OA symptoms. AIM: The aim of the study was to test the hypothesis that dietary supplementation with MF relieves clinical signs and symptoms of OA of the hands. SETTING: The study was done at the MEDSAC hospital in Somerset West, Western Cape, South Africa. METHODS: The research was conducted in two stages. An open interventional study (n = 40) confirmed the notion that MF 7.5 g twice daily is likely to be an effective alternative or adjunct for relief of symptoms of OA of the hands. The main study was conducted with 100 eligible, consenting volunteers (aged 47-89 years) according to a randomised, placebo-controlled, crossover design. Study duration was 56 days, 28 days per regimen; crossover to alternate regimens took place on day 28. RESULTS: Compared to placebo, MF intake over 28 days was associated with significant reductions ( p < 0.005) in pain, tenderness and stiffness of interphalangeal and metacarpophalangeal joints of the hand. Confirmation of systemic alkalinisation by MF, which is rich in organic anions in the form of citrate salts, was reflected by a significant and sustained increase in urine pH. CONCLUSION: A dietary supplement, Multiforce® Alkaline Powder, containing citrate salts which are converted into bicarbonate in vivo, was efficacious and safe as sole therapeutic intervention, significantly attenuating OA-associated signs and symptoms of the hands.


Subject(s)
Adjuvants, Pharmaceutic/therapeutic use , Antacids/therapeutic use , Cross-Over Studies , Dietary Supplements , Osteoarthritis/drug therapy , Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , South Africa
4.
Crit Rev Clin Lab Sci ; 52(3): 120-37, 2015.
Article in English | MEDLINE | ID: mdl-25597499

ABSTRACT

Genomic medicine is based on the knowledge that virtually every medical condition, disease susceptibility or response to treatment is caused, regulated or influenced by genes. Genetic testing may therefore add value across the disease spectrum, ranging from single-gene disorders with a Mendelian inheritance pattern to complex multi-factorial diseases. The critical factors for genomic risk prediction are to determine: (1) where the genomic footprint of a particular susceptibility or dysfunction resides within this continuum, and (2) to what extent the genetic determinants are modified by environmental exposures. Regarding the small subset of highly penetrant monogenic disorders, a positive family history and early disease onset are mostly sufficient to determine the appropriateness of genetic testing in the index case and to inform pre-symptomatic diagnosis in at-risk family members. In more prevalent polygenic non-communicable diseases (NCDs), the use of appropriate eligibility criteria is required to ensure a balance between benefit and risk. An additional screening step may therefore be necessary to identify individuals most likely to benefit from genetic testing. This need provided the stimulus for the development of a pathology-supported genetic testing (PSGT) service as a new model for the translational implementation of genomic medicine in clinical practice. PSGT is linked to the establishment of a research database proven to be an invaluable resource for the validation of novel and previously described gene-disease associations replicated in the South African population for a broad range of NCDs associated with increased cardio-metabolic risk. The clinical importance of inquiry concerning family history in determining eligibility for personalized genotyping was supported beyond its current limited role in diagnosing or screening for monogenic subtypes of NCDs. With the recent introduction of advanced microarray-based breast cancer subtyping, genetic testing has extended beyond the genome of the host to also include tumor gene expression profiling for chemotherapy selection. The decreasing cost of next generation sequencing over recent years, together with improvement of both laboratory and computational protocols, enables the mapping of rare genetic disorders and discovery of shared genetic risk factors as novel therapeutic targets across diagnostic boundaries. This article reviews the challenges, successes, increasing inter-disciplinary integration and evolving strategies for extending PSGT towards exome and whole genome sequencing (WGS) within a dynamic framework. Specific points of overlap are highlighted between the application of PSGT and exome or WGS, as the next logical step in genetically uncharacterized patients for whom a particular disease pattern and/or therapeutic failure are not adequately accounted for during the PSGT pre-screen. Discrepancies between different next generation sequencing platforms and low concordance among variant-calling pipelines caution against offering exome or WGS as a stand-alone diagnostic approach. The public reference human genome sequence (hg19) contains minor alleles at more than 1 million loci and variant calling using an advanced major allele reference genome sequence is crucial to ensure data integrity. Understanding that genomic risk prediction is not deterministic but rather probabilistic provides the opportunity for disease prevention and targeted treatment in a way that is unique to each individual patient.


Subject(s)
Evidence-Based Medicine , Genetic Predisposition to Disease , Genomics/methods , Precision Medicine/methods , Databases, Genetic , Family Health , Genetic Testing , Humans , Precision Medicine/ethics
5.
Per Med ; 10(5): 497-507, 2013 Jul.
Article in English | MEDLINE | ID: mdl-29758833

ABSTRACT

Several chronic, noncommunicable diseases share common genetic risk factors. These include cardiovascular disease and several neurological and psychiatric disorders, as well as some forms of cancer. Clinical compartmentalization and the challenges of translational research have delayed the implementation of personalized medicine. To overcome these limitations, a pathology-supported genetic testing service has been established to enable the incorporation of genomics into a universally accepted body of knowledge. An online questionnaire is used to obtain information on personal and family medical conditions, medication use/side effects, lifestyle factors and pathology test results relevant to the genetic analysis performed. Validation studies from multidisciplinary sources and the expanding Gknowmix™ database are applied to determine whether the clinical characteristics of the patient match the test results. With this approach, a set of common functional polymorphisms at critical control points within key biological pathways can be studied to determine current or future clinical relevance across diagnostic boundaries.

6.
Ann N Y Acad Sci ; 957: 329-32, 2002 May.
Article in English | MEDLINE | ID: mdl-12074991

ABSTRACT

We compared the in vivo effect of red vs. white wine consumption on platelet aggregation, responsiveness and membrane viscosity, plasma total antioxidant status, thromboxane B(2) levels, and fibrinolysis. Diet and red wine had a synergistic effect in decreasing platelet aggregation. Red wine did not have a significantly more favorable effect on the fibrinolytic factors than white wine. The reduction in platelet membrane viscosity after red wine, which could contribute to the protective antithrombotic role of red wine, needs further explanation.


Subject(s)
Alcohol Drinking , Blood Platelets/drug effects , Blood Platelets/physiology , Fibrinolytic Agents/pharmacology , Hemostasis/drug effects , Wine , Adult , Antioxidants/analysis , Cell Membrane/drug effects , Cell Membrane/physiology , Female , Fibrinogen/analysis , Fibrinolysis/drug effects , Humans , Male , Middle Aged , Platelet Aggregation/drug effects , Viscosity/drug effects
7.
Ann N Y Acad Sci ; 957: 337-40, 2002 May.
Article in English | MEDLINE | ID: mdl-12074993

ABSTRACT

We investigated the in vivo effects of regular consumption of red and white wine on the serum lipid profile, plasma plasminogen activator-1, homocysteine levels, and total antioxidant status. This study confirmed that moderate consumption of wine, red more than white, exerts cardioprotective effects through beneficial changes in lipid profiles and plasma total antioxidant status.


Subject(s)
Antioxidants/analysis , Cardiotonic Agents/pharmacology , Homocysteine/blood , Lipids/blood , Plasminogen Activator Inhibitor 1/blood , Wine , Adult , Female , Humans , Male , Middle Aged
8.
Redox Rep ; 7(5): 315-6, 2002.
Article in English | MEDLINE | ID: mdl-12688518

ABSTRACT

A review of the literature on the 'antioxidant' action of white wines on the cardiovascular system is given. The conclusion is that ingestion only of white wines very low, or lacking, in polyphenolics leads to a reduction in the antioxidant action of blood serum, and to an increase in the low density lipoprotein to high density lipoprotein ratio.


Subject(s)
Antioxidants/pharmacology , Wine , Antioxidants/metabolism , Cardiovascular System/drug effects , Female , Humans , Lipoproteins, LDL/metabolism , Male , Phenols/pharmacology
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