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1.
Vaccine ; 37(37): 5513-5514, 2019 09 03.
Artículo en Inglés | MEDLINE | ID: mdl-30545714

RESUMEN

Human papillomavirus (HPV) vaccines are currently utilised globally in national immunisation programmes. In July 2017, a national HPV vaccine programme for men who have sex with men (MSM) was initiated across Scotland with vaccine being offered in the sexual health clinic setting. During the first year of this targeted vaccination programme, there were 5905 individuals who received at least one dose of HPV vaccine, representing 63.7% of eligible MSM attendees in this period. Vaccine uptake was relatively stable across all age groups (range 49.8-55.5%). The vaccination programme appears to have dovetailed well with pre-existing sexual health services and appears to be popular with MSM attending the service. The MSM HPV vaccine programme is a robust adjunct to the national girls programme but gender-neutral immunisation will reduce stigma and inequality in HPV-driven disease.


Asunto(s)
Homosexualidad Masculina , Infecciones por Papillomavirus/prevención & control , Vacunas contra Papillomavirus/administración & dosificación , Vacunas contra Papillomavirus/inmunología , Adolescente , Adulto , Humanos , Programas de Inmunización , Masculino , Persona de Mediana Edad , Vigilancia en Salud Pública , Escocia/epidemiología , Conducta Sexual , Vacunación , Adulto Joven
2.
Sci Rep ; 7(1): 11705, 2017 09 15.
Artículo en Inglés | MEDLINE | ID: mdl-28916828

RESUMEN

The African grass Andropogon gayanus Kunth. is invading Australian savannas, altering their ecological and biogeochemical function. To assess impacts on nitrogen (N) cycling, we quantified litter decomposition and N dynamics of grass litter in native grass and A. gayanus invaded savanna using destructive in situ grass litter harvests and litterbag incubations (soil surface and aerial position). Only 30% of the A. gayanus in situ litter decomposed, compared to 61% of the native grass litter, due to the former being largely comprised of highly resistant A. gayanus stem. In contrast to the stem, A. gayanus leaf decomposition was approximately 3- and 2-times higher than the dominant native grass, Alloteropsis semilata at the surface and aerial position, respectively. Lower initial lignin concentrations, and higher consumption by termites, accounted for the greater surface decomposition rate of A. gayanus. N flux estimates suggest the N release of A. gayanus litter is insufficient to compensate for increased N uptake and N loss via fire in invaded plots. Annually burnt invaded savanna may lose up to 8.2% of the upper soil N pool over a decade. Without additional inputs via biological N fixation, A. gayanus invasion is likely to diminish the N capital of Australia's frequently burnt savannas.


Asunto(s)
Andropogon/metabolismo , Especies Introducidas , Nitrógeno/metabolismo , Poaceae/metabolismo , Animales , Australia , Ecosistema , Incendios , Pradera , Isópteros , Hojas de la Planta/metabolismo
3.
J Strength Cond Res ; 26(4): 1015-26, 2012 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-22446671

RESUMEN

The purpose of this study was to determine the reliability of eccentric (ECC) and concentric (CON) kinematic and kinetic variables thought to be critical to jump performance during bilateral vertical countermovement jump (VCMJ) and horizontal countermovement jump (HCMJ) across children of different maturity status. Forty-two athletic male and female participants between 9 and 16 years of age were divided into 3 maturity groups according to peak height velocity (PHV) offset (Post-PHV, At-PHV, and Pre-PHV) and percent of predicted adult stature. All the participants performed 3 VCMJ and HCMJ trials and the kinematics, and kinetics of these jumps were measured via a force plate over 3 testing sessions. In both jumps, vertical CON mean and peak power and jump height or distance were the most reliable measures across all groups (change in the mean [CM] = -5.4 to 6.2%; coefficient of variation [CV] = 2.1-9.4%; Intraclass correlation coefficient [ICC] = 0.82-0.98), whereas vertical ECC mean power was the only ECC variable with acceptable reliability for both jumps (CM = -0.7 to 10.1%; CV = 5.2-15.6%; ICC = 0.74-0.97). A less mature state was "likely" to "very likely" to reduce the reliability of the HCMJ ECC kinetics and kinematics. These findings suggested that movement variability is associated with the ECC phase of CMJs, especially in Pre-PHV during the HCMJ. Vertical CON mean and peak power and ECC mean power were deemed reliable and appropriate to be used in children as indicators of jump and stretch-shortening cycle performance.


Asunto(s)
Rendimiento Atlético , Movimiento , Adolescente , Fenómenos Biomecánicos , Niño , Femenino , Humanos , Pierna/fisiología , Masculino , Fuerza Muscular , Reproducibilidad de los Resultados
4.
Mol Pharmacol ; 80(4): 573-84, 2011 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-21709136

RESUMEN

Voltage-gated sodium channels are important in initiating and propagating nerve impulses in various tissues, including cardiac muscle, skeletal muscle, the brain, and the peripheral nerves. Hyperexcitability of these channels leads to such disorders as cardiac arrhythmias (Na(v)1.5), myotonias (Na(v)1.4), epilepsies (Na(v)1.2), and pain (Na(v)1.7). Thus, there is strong motivation to identify isoform-specific blockers and the molecular determinants underlying their selectivity among these channels. µ-Conotoxin KIIIA blocks rNa(v)1.2 (IC(50), 5 nM), rNa(v)1.4 (37 nM), and hNa(v)1.7 (97 nM), expressed in mammalian cells, with high affinity and a maximal block at saturating concentrations of 90 to 95%. Mutations of charged residues on both the toxin and channel modulate the maximal block and/or affinity of KIIIA. Two toxin substitutions, K7A and R10A, modulate the maximal block (52-70%). KIIIA-H12A and R14A were the only derivatives tested that altered Na(v) isoform specificity. KIIIA-R14A showed the highest affinity for Na(v)1.7, a channel involved in pain signaling. Wild-type KIIIA has a 2-fold higher affinity for Na(v)1.4 than for Na(v)1.7, which can be attributed to a missing outer vestibule charge in domain III of Na(v)1.7. Reciprocal mutations Na(v)1.4 D1241I and Na(v)1.7 I1410D remove the affinity differences between these two channels for wild-type KIIIA without affecting their affinities for KIIIA-R14A. KIIIA is the first µ-conotoxin to show enhanced activity as pH is lowered, apparently resulting from titration of the free N terminus. Removal of this free amino group reduced the pH sensitivity by 10-fold. Recognition of these molecular determinants of KIIIA block may facilitate further development of subtype-specific, sodium channel blockers to treat hyperexcitability disorders.


Asunto(s)
Conotoxinas/genética , Conotoxinas/metabolismo , Neuronas/metabolismo , Bloqueadores de los Canales de Sodio/metabolismo , Canales de Sodio/metabolismo , Secuencia de Aminoácidos , Conotoxinas/química , Relación Dosis-Respuesta a Droga , Células HEK293 , Humanos , Datos de Secuencia Molecular , Unión Proteica/fisiología , Estructura Secundaria de Proteína , Bloqueadores de los Canales de Sodio/química
5.
Mol Pharmacol ; 80(2): 219-27, 2011 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-21521769

RESUMEN

Mutant cycle analysis has been used in previous studies to constrain possible docking orientations for various toxins. As an independent test of the bound orientation of µ-conotoxin PIIIA, a selectively targeted sodium channel pore blocker, we determined the contributions to binding voltage dependence of specific residues on the surface of the toxin. A change in the "apparent valence" (zδ) of the block, which is associated with a change of a specific toxin charge, reflects a change in the charge movement within the transmembrane electric field as the toxin binds. Toxin derivatives with charge-conserving mutations (R12K, R14K, and K17R) showed zδ values similar to those of wild type (0.61 ± 0.01, mean ± S.E.M.). Charge-changing mutations produced a range of responses. Neutralizing substitutions for Arg14 and Lys17 showed the largest reductions in zδ values, to 0.18 ± 0.06 and 0.20 ± 0.06, respectively, whereas unit charge-changing substitutions for Arg12, Ser13, and Arg20 gave intermediate values (0.24 ± 0.07, 0.33 ± 0.04, and 0.32 ± 0.05), which suggests that each of these residues contributes to the dependence of binding on the transmembrane voltage. Two mutations, R2A and G6K, yielded no significant change in zδ. These observations suggest that the toxin binds with Arg2 and Gly6 facing the extracellular solution, and Arg14 and Lys17 positioned most deeply in the pore. In this study, we used molecular dynamics to simulate toxin docking and performed Poisson-Boltzmann calculations to estimate the changes in local electrostatic potential when individual charges were substituted on the toxin's surface. Consideration of two limiting possibilities suggests that most of the charge movement associated with toxin binding reflects sodium redistribution within the narrow part of the pore.


Asunto(s)
Conotoxinas/química , Conotoxinas/metabolismo , Activación del Canal Iónico/fisiología , Bloqueadores de los Canales de Sodio/metabolismo , Canales de Sodio/metabolismo , Secuencia de Aminoácidos , Animales , Sitios de Unión/fisiología , Simulación de Dinámica Molecular , Datos de Secuencia Molecular , Técnicas de Placa-Clamp , Unión Proteica/fisiología , Ratas , Sarcolema/química , Sarcolema/metabolismo , Bloqueadores de los Canales de Sodio/química , Canales de Sodio/química
6.
J Strength Cond Res ; 24(8): 2056-64, 2010 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-20613648

RESUMEN

Rubber-based resistance (RBR) bands and standard link steel (SLS) chains are 2 forms of variable resistance used throughout the strength and conditioning and rehabilitation communities. The purpose of this study was to quantify the tension of RBR bands and the mass of SLS chains as a function of displacement (increasing in 10-cm increments). Five sets of RBR bands (14-, 22-, 30-, 48-, and 67-mm widths) and 5 sets of SLS chains (6-, 8-, 10-, 13-, 16-mm diameters) were measured using a load cell and a force plate. The RBR bands exhibited curvilinear tension-deformation relationships and were best represented (R >or= 0.99) by second-order polynomial functions, whereas the SLS chains exhibited linear mass-displacement relationships and were best represented (R = 1) by first-order polynomial functions. There were no significant differences (p > 0.05) in force outputs between the load cell and the force plate testing, although the strain gauge is a relatively cheap and viable method of quantifying the variable resistance of chains and bands. The strength and conditioning practitioner when purchasing bands needs to be aware of resting length differences (3.5-5.2%), which resulted in mean tension imbalances of 8-19% in the same color band. This study provides the strength and conditioning coach and clinician with a methodology to quantify variable resistance, which may be useful in the prescription of specific loading intensities.


Asunto(s)
Entrenamiento de Fuerza/instrumentación , Elasticidad , Goma , Estrés Mecánico , Resistencia a la Tracción , Soporte de Peso
7.
Diabetes Obes Metab ; 6(6): 432-41, 2004 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-15479219

RESUMEN

AIM: Excess levels of free radicals such as nitric oxide (NO) and superoxide anion (O(2)(-)) are associated with the pathogenesis of endothelial cell dysfunction in diabetes mellitus. This study was designed to investigate the underlying causes of oxidative stress in coronary microvascular endothelial cells (CMECs) exposed to hyperglycaemia. METHODS: CMECs were cultured under normal (5.5 mmol/l) or high glucose (22 mmol/l) concentrations for 7 days. The activity and expression (protein level) of endothelial NO synthase (eNOS), inducible NOS (iNOS), NAD(p)H oxidase and antioxidant enzymes, namely, superoxide dismutase (SOD), catalase and glutathione peroxidase (GPx) were investigated by specific activity assays and Western analyses, respectively, while the effects of hyperglycaemia on nitrite and O(2)(-) generation were investigated by Griess reaction and cytochrome C reduction assay, respectively. RESULTS: Hyperglycaemia did not alter eNOS or iNOS protein expressions and overall nitrite generation, an index of NO production. However, it significantly reduced the levels of intracellular antioxidant glutathione by 50% (p < 0.05) and increased the protein expressions and activities of p22-phox, a membrane-bound component of pro-oxidant NAD(p)H oxidase and antioxidant enzymes (p < 0.05). Free radical scavengers, namely, Tiron and mercaptopropionylglycine (MPG) (0.1-1 micromol/l) reduced hyperglycaemia-induced antioxidant enzyme activity and increased glutathione and nitrite generation to the levels observed in CMEC cultured in normoglycaemic medium (p < 0.01). The differences in enzyme activity and expressions were independent of the increased osmolarity generated by high glucose levels as investigated by using equimolar concentrations of mannitol in parallel experiments. CONCLUSIONS: These results suggest that hyperglycaemia-induced oxidative stress may arise in CMEC as a result of enhanced pro-oxidant enzyme activity and diminished generation of antioxidant glutathione. By increasing the antioxidant enzyme capacity, CMEC may protect themselves against free radical-induced cell damage in diabetic conditions.


Asunto(s)
Antioxidantes/metabolismo , Vasos Coronarios/enzimología , Endotelio Vascular/enzimología , Glucosa/farmacología , Especies Reactivas de Oxígeno/metabolismo , Animales , Western Blotting , Supervivencia Celular/efectos de los fármacos , Células Cultivadas , Vasos Coronarios/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Células Endoteliales/efectos de los fármacos , Células Endoteliales/enzimología , Endotelio Vascular/efectos de los fármacos , Activación Enzimática/efectos de los fármacos , Glutatión/metabolismo , Proteínas de Transporte de Membrana/metabolismo , NADPH Deshidrogenasa/metabolismo , NADPH Oxidasas , Óxido Nítrico Sintasa/metabolismo , Óxido Nítrico Sintasa de Tipo II , Nitritos/metabolismo , Estrés Oxidativo/fisiología , Fosfoproteínas/metabolismo , Ratas , Ratas Wistar
8.
Diabetes Obes Metab ; 6(6): 442-51, 2004 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-15479220

RESUMEN

OBJECTIVE: Vitamins C and E have protective features in many disease states associated with enhanced oxidative stress. The aim of this study was to investigate whether vitamin(s) C and/or E modulate hyperglycaemia-induced oxidative stress by regulating enzymatic activities of prooxidant, i.e. NAD(P)H oxidase and/or antioxidant enzymes, namely endothelial nitric oxide synthase (eNOS), superoxide dismutase, catalase and glutathione peroxidase, using coronary microvascular endothelial cells (CMEC). METHODS: CMEC were cultured under normal (5.5 mM) or high glucose (22 mM) concentrations for 7 days. The enzyme activities were determined by specific assays. The levels of O(2) (-) and nitrite were measured by cytochrome c reduction and Griess assays respectively. RESULTS: Hyperglycaemia did not alter eNOS activity or overall nitrite generation, an index of NO production. However, it increased NAD(P)H oxidase and antioxidant enzyme activities (p < 0.05). Specific inhibitors of NAD(P)H oxidase, i.e. phenylarsine oxide (0.1-3 microm) and 4-(2-aminoethyl)benzenesulfonyl fluoride (5-100 microm) and vitamins C and E (0.1-1 microm) significantly reduced prooxidant and antioxidant enzyme activities in CMEC exposed to hyperglycaemia (p < 0.01). The differences in enzyme activities were independent of increases in osmolarity generated by high glucose levels as investigated by using equimolar concentrations of mannitol in parallel experiments. CONCLUSIONS: Vitamins C and E may protect CMEC against hyperglycaemia-induced oxidative stress by concomitantly regulating prooxidant and antioxidant enzyme activities.


Asunto(s)
Antioxidantes/farmacología , Ácido Ascórbico/farmacología , Endotelio Vascular/efectos de los fármacos , Estrés Oxidativo/efectos de los fármacos , Vitamina E/farmacología , Animales , Supervivencia Celular/efectos de los fármacos , Supervivencia Celular/fisiología , Células Cultivadas , Vasos Coronarios/efectos de los fármacos , Vasos Coronarios/fisiopatología , Relación Dosis-Respuesta a Droga , Células Endoteliales/efectos de los fármacos , Células Endoteliales/enzimología , Células Endoteliales/fisiología , Endotelio Vascular/enzimología , Endotelio Vascular/fisiopatología , Inhibidores Enzimáticos/farmacología , Glucosa/farmacología , NADH NADPH Oxidorreductasas/antagonistas & inhibidores , NADH NADPH Oxidorreductasas/metabolismo , NADPH Oxidasas , Óxido Nítrico Sintasa/metabolismo , Nitritos/metabolismo , Oxidantes/metabolismo , Ratas , Ratas Wistar , Especies Reactivas de Oxígeno/metabolismo
9.
Ann N Y Acad Sci ; 1019: 392-5, 2004 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-15247052

RESUMEN

Glutathione and glutathione peroxidase activity are important components in the complex body defense against oxidative damage. In this study, we have measured malondialdehyde (MDA) as a marker of oxidative stress, the antioxidant glutathione (GSH), and activity of the antioxidant enzyme (GSHPx), in a cohort of free-living elderly subjects from the Belfast Elderly Longitudinal Free-living Aging STudy (BELFAST), hypothesizing that free-living Senieur-approximated nonagenarians might demonstrate enhanced antioxidant defense mechanisms. The main finding in the BELFAST octo/nonagenarians was that plasma antioxidant glutathione increased in nonagenarian compared with septo/octogenarian subjects (P =.015), whereas conversely antioxidant glutathione peroxidase activity fell in the nonagenarian group (P <.0001). In the same subject group, malondialdehyde, a measure of lipid peroxidation, showed no change across the age groups (P =.73). These results might overall represent a situation in which elderly survivors in the BELFAST study have evolved a sort of free radical/antioxidant equilibrium as a mechanism of successful aging.


Asunto(s)
Envejecimiento , Malondialdehído/metabolismo , Anciano , Anciano de 80 o más Años , Antioxidantes/metabolismo , Antioxidantes/farmacología , Estudios de Cohortes , Femenino , Radicales Libres , Glutatión/metabolismo , Glutatión Peroxidasa/metabolismo , Humanos , Peroxidación de Lípido , Masculino , Irlanda del Norte
10.
Diabetologia ; 46(1): 106-14, 2003 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-12637989

RESUMEN

AIMS/HYPOTHESIS: Abnormalities of glucose and fatty acid metabolism in diabetes are believed to contribute to the development of oxidative stress and the long term vascular complications of the disease; therefore the interactions of glucose and long chain fatty acids on free radical damage and endogenous antioxidant defences were investigated in vascular smooth muscle cells. METHODS: Porcine vascular smooth muscle cells were cultured in 5 mmol/l or 25 mmol/l glucose for 10 days. Fatty acids, stearic acid (18:0), oleic acid (18:1), linoleic acid (18:2) and alpha-linolenic acid (18:3) were added with defatted bovine serum albumin as a carrier for the final three days. RESULTS: Glucose (25 mmol/l) alone caused oxidative stress in the cells as evidenced by free radical-mediated damage to DNA, lipids, and proteins. The addition of fatty acids (0.2 mmol/l) altered the profile of free radical damage; the response was J-shaped with respect to the degree of unsaturation of each acid, and oleic acid was associated with least damage. At a lower concentration alpha-linolenic acid (0.01 mmol/l) was markedly different in that, when added to 25 mmol/l glucose it resulted in a decrease in free radical damage to DNA, lipids and proteins. This was accompanied by a marked increase in antioxidant and glutathione concentrations as well as by increased gene expression is of gamma-glutamylcysteine synthetase, the rate-limiting enzyme in glutathione synthesis. CONCLUSIONS/INTERPRETATION: The results clearly show that glucose and fatty acids interact in the production of oxidative stress in vascular smooth muscle cells.


Asunto(s)
Antioxidantes/metabolismo , Ácidos Grasos/farmacología , Radicales Libres/metabolismo , Glucosa/farmacología , Músculo Liso Vascular/metabolismo , Miocitos del Músculo Liso/metabolismo , Animales , Catalasa/genética , Catalasa/metabolismo , Células Cultivadas , Fragmentación del ADN/efectos de los fármacos , Ácidos Grasos/metabolismo , Expresión Génica/efectos de los fármacos , Glutamato-Cisteína Ligasa/genética , Glutamato-Cisteína Ligasa/metabolismo , Glutatión/metabolismo , Glutatión Peroxidasa/metabolismo , Glutatión Reductasa/metabolismo , Malondialdehído/metabolismo , Músculo Liso Vascular/efectos de los fármacos , Músculo Liso Vascular/patología , Miocitos del Músculo Liso/efectos de los fármacos , Miocitos del Músculo Liso/patología , Oxidación-Reducción/efectos de los fármacos , Proteínas/metabolismo , Superóxido Dismutasa/metabolismo , Porcinos
11.
Free Radic Biol Med ; 31(10): 1149-55, 2001 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-11705692

RESUMEN

Hyperglycemia-induced oxidative stress may play a key role in the pathogenesis of diabetic vascular disease. The purpose of this study was to determine the effects of glucose on levels of glutathione (a major intracellular antioxidant), the expression of gamma-glutamylcysteine synthetase (the rate-limiting enzyme in glutathione de novo synthesis), and DNA damage in human vascular smooth muscle cells in vitro. High glucose conditions and buthionine sulphoximine, an inhibitor of gamma-glutamylcysteine synthetase, reduced intracellular glutathione levels in vascular smooth muscle cells. This reduction was accompanied by a decrease in the mRNA expression of both subunits of gamma-glutamylcysteine synthetase as well as an increase in DNA damage. In high glucose conditions, incubation of the vascular smooth muscle cells with alpha-lipoic acid and L-cystine restored glutathione levels. We suggest that the decrease in GSH levels seen in high glucose conditions is mediated by the availability of cysteine (rate-limiting substrate in de novo glutathione synthesis) and the gene expression of the gamma-glutamylcysteine synthetase enzyme. Glutathione depletion is associated with an increase in DNA damage, which can be reduced when glutathione levels are restored.


Asunto(s)
Daño del ADN/efectos de los fármacos , Glucosa/farmacología , Glutamato-Cisteína Ligasa/metabolismo , Glutatión/metabolismo , Músculo Liso Vascular/metabolismo , Aorta/citología , Butionina Sulfoximina/farmacología , Células Cultivadas , Cisteína/farmacología , Glutamato-Cisteína Ligasa/genética , Humanos , Músculo Liso Vascular/citología , Músculo Liso Vascular/efectos de los fármacos , ARN Mensajero/efectos de los fármacos , ARN Mensajero/metabolismo , Ácido Tióctico/farmacología
12.
Mech Ageing Dev ; 122(13): 1367-72, 2001 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-11470126

RESUMEN

The ApoE gene has three alleles coding for the proteins apoE2, apoE3 and apoE4. E4 has been reported to be associated with hypercholesteraemia, ischaemic heart disease, age-related cognitive decline and Alzheimer's disease. Conversely, the E2 allele has been associated with longevity in French centenarians and their siblings. In this study, we have assessed any shift in the ApoE genotypes in nonagenarian subjects from Belfast where there is a high intrinsic incidence of cardiovascular disease. ApoE phenotypes were determined by electrofocusing and immunoblotting in 114 Senieur-approximated subjects >90 years old and compared with 2071 subjects, 30--65 years of age, recruited from the same geographical area by the MONItoring of CArdiovascular trends study group in Belfast (MONICA). The E4 allele was reduced in the nonagenarian group (X(2)=11.1; P=0.0006), the E3 unchanged and E2 frequency was increased (X(2)=4.0; P=0.047). These results suggest that longevity is negatively associated with the E4 allele and may be associated with carriage of E2.


Asunto(s)
Alelos , Apolipoproteínas E/genética , Adulto , Anciano , Anciano de 80 o más Años , Envejecimiento , Apolipoproteína E2 , Apolipoproteína E4 , Humanos , Estudios Longitudinales , Persona de Mediana Edad
13.
Atherosclerosis ; 157(2): 451-6, 2001 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-11472746

RESUMEN

Epidemiological evidence has revealed that an elevated plasma homocysteine level (hyperhomocysteinemia) confers an increased risk of cardiovascular disease and neural tube defects. Hyperhomocysteinemia is caused by both nutritional (e.g. folate, vitamins B(6) and B(12)) and genetic factors, including functional polymorphisms of key enzymes involved in homocysteine metabolism. One such enzyme, methionine synthase reductase (MTRR), maintains adequate levels of methylcob(III)alamin, the activated cofactor for methionine synthase, which catalyzes the remethylation of homocysteine to methionine. A common MTRR polymorphism, i.e. a 66 A-->G substitution specifying an isoleucine to methionine substitution (I22M), was recently identified. To assess the influence of this polymorphism on total plasma homocysteine (tHcy), we undertook a genotype/phenotype analysis in a study population of 601 Northern-Irish men, aged 30--49, for which biochemical and genetic data relevant to folate/homocysteine metabolism had already been acquired. The 66AA genotype has a frequency of 29% in this population. We established that there was a significant influence of MTRR genotype on tHcy ranking (P=0.004) and that the 66AA genotype contributes to a moderate increase in tHcy levels across the distribution [OR 1.59 (95% CI: 1.10--2.25) for the 66AA genotype to be in the upper half of the tHcy distribution, P=0.03]. The homocysteine-elevating effect of the 66AA genotype is independent of serum folate, vitamin B(12) and vitamin B(6) levels. Based on published estimates of the enhanced cardiovascular disease risk conferred by defined increments of plasma tHcy, we estimate that 66AA homozygotes have, on average, an approximately 4% increase in cardiovascular disease risk compared to 66GG homozygotes. This study provides the first evidence that the MTRR A66G polymorphism significantly influences the circulating tHcy concentration.


Asunto(s)
Ferredoxina-NADP Reductasa/genética , Predisposición Genética a la Enfermedad , Homocisteína/sangre , Hiperhomocisteinemia/genética , Polimorfismo Genético/fisiología , Adulto , Frecuencia de los Genes , Genotipo , Humanos , Masculino , Persona de Mediana Edad , Concentración Osmolar
14.
Eur J Clin Invest ; 30(12): 1076-82, 2000 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-11122322

RESUMEN

BACKGROUND: Findings relating an association between an insertion/deletion polymorphism of the angiotensin converting enzyme (ACE) gene and myocardial infarction (MI) have been mixed. While other loci, such as the angiotensin II type-I receptor (AT1R), may modulate risk, few studies have adequately documented the risk in women. We aimed to study whether the findings in respect of ACE and AT1R in UK men were borne out in women. METHODS: Cases of MI (305 women, 391 men) in Belfast and Glasgow have been compared to controls (291 women, 356 men). These new samples augment the original men (200 cases, 181 controls) included from Belfast in the ECTIM study. RESULTS: Among men, the odds ratio for MI for ACE (DD vs. ID + II) was 1.03 (0.79, 1.34) and among women, 0.69 (0.47, 1.01). This heterogeneity between the risks in men and women was significant in Glasgow (P = 0.02). Among men and women the odds ratio for MI for AT1R (CC vs. AC + AA) was 1.02 (0.71, 1.47). There was a small gradient in risk, such that the odds ratio for DD genotype was 0.86 (0.63, 1.17) among subjects homozygous for the common AT1R allele (AA): 0.94 (0.67, 1.30) among heterozygotes and 1.21 (0.53, 2.77) among CC subjects; but this interaction was not statistically significant. CONCLUSIONS: Some of the contradictory findings concerning the ACE polymorphism and the risk of MI may be due to heterogeneity in the risk between men and women. The AT1R1196 polymorphism is not an independent risk factor for MI in either sex.


Asunto(s)
Infarto del Miocardio/genética , Peptidil-Dipeptidasa A/genética , Polimorfismo Genético , Receptores de Angiotensina/genética , Adulto , Anciano , Estudios de Casos y Controles , Femenino , Predisposición Genética a la Enfermedad , Genotipo , Humanos , Masculino , Persona de Mediana Edad , Oportunidad Relativa , Receptor de Angiotensina Tipo 1 , Receptor de Angiotensina Tipo 2 , Factores de Riesgo , Factores Sexuales
15.
Atherosclerosis ; 153(1): 119-28, 2000 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-11058706

RESUMEN

To assess whether there is a differential hypocholesterolemic response to weight loss for subjects carrying polymorphisms of the apolipoprotein B and other genes. A before and after comparison of lipid parameters following a calorie controlled diet for an intervention period of 12 weeks. A lipid clinic based in a large teaching hospital. The difference in slope coefficients relating the percentage change in lipid parameters to the change in body weight (adjusted for age, gender and initial body mass index (BMI)), for genotype subgroups defined by polymorphisms of the 5'VNTR apoB gene, two mutations of the LPL gene and ApoE. One hundred and forty six subjects completed the intervention diet. While, on average, the intervention was successful (mean weight loss 3.9%), there was no statistically significant difference in the slope coefficients relating lipid change to weight loss for most of the genotypes tested. The slope difference for long versus short 5'VNTR alleles of the apoB gene was 0.445 (-1.307, 2.198) for apolipoprotein B and -0. 104 (-1.486, 1.278) for total cholesterol. However, subjects carrying at least one varepsilon4 allele were significantly hypo-responsive to weight loss, difference in slope coefficients -1.087 (-2.09, -0.084) and -1.320 (-2.589, 0.051) for total cholesterol and apoB, respectively. Although, this study is one of the largest of its kind, it has not replicated the findings of other smaller studies. These findings do not provide support for the use of genotype-targeted dietary advice in routine practice.


Asunto(s)
Apolipoproteínas B/genética , Apolipoproteínas E/genética , Colesterol/sangre , Lipoproteína Lipasa/genética , Polimorfismo Genético/fisiología , Pérdida de Peso/fisiología , Adulto , Dieta Reductora , Femenino , Genotipo , Humanos , Lípidos/sangre , Masculino , Persona de Mediana Edad
16.
Heart ; 84(5): 548-52, 2000 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-11040019

RESUMEN

BACKGROUND AND OBJECTIVE: Studies in animal models and humans implicate cell adhesion molecules in atherogenesis but their role in mediating the risk of myocardial infarction is unclear. The ECTIM (étude cas-temoin de l'infarctus myocarde) extension study was established to determine whether a previously implicated polymorphism of the P-selectin gene was associated with myocardial infarction risk in men and women in Belfast and Glasgow. PATIENTS AND STUDY SETTING: 696 cases with a recent myocardial infarction and 561 age matched controls (both male and female) were recruited into a case-control study in MONICA project areas of Belfast and Glasgow. METHODS: Demographic and lifestyle information was collected by interview administered questionnaire, and each subject was examined and provided a blood sample for DNA extraction. The polymerase chain reaction (PCR) was used to amplify regions encompassing the P-selectin Thr-->Pro (A/C) polymorphism at position 715. Genotype odds ratios for myocardial infarction were estimated by logistic regression adjusted for population, age, and sex. RESULTS: There was no significant association between conventional risk factors (such as hypercholesterolaemia, increased body mass index, or raised blood pressure) and either the rare or the common Pro(715) allele of the P-selectin gene in controls. Overall, comparing Pro(715)/Pro(715) and Pro(715)/Thr(715) with Thr(715)/Thr(715), with adjustment for centre, age, and sex, the odds ratio was 0.78 (95% confidence interval 0.60 to 1.00) (p = 0.054), indicating a "protective" effect of the less common Pro(715) allele. There was no significant heterogeneity in odds ratios between men and women either in this sample or when combined with the original ECTIM subjects. CONCLUSIONS: In a large population based study in two regions of the UK, we have been able to corroborate the earlier ECTIM findings of a lower frequency of the Thr/Pro(715) polymorphism in subjects with myocardial infarction. An apparently "protective effect" of similar magnitude also seems to apply to women.


Asunto(s)
Infarto del Miocardio/genética , Selectina-P/genética , Polimorfismo Genético , Estudios de Casos y Controles , Femenino , Genotipo , Humanos , Masculino , Persona de Mediana Edad , Factores de Riesgo
18.
J Hum Hypertens ; 14(8): 511-8, 2000 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-10962519

RESUMEN

AIMS: To assess the association of hypertensive status and antihypertensive drug treatment with lipid and haemostatic levels in middle-aged men. METHODS AND RESULTS: Hypertensive status, antihypertensive drug treatment, total and high-density lipoprotein (HDL) cholesterol, triglyceride, apoproteins A-I and B, lipoparticles LpA-I, LpE:B and Lp(a), fibrinogen, plasminogen activator inhibitor-1 (PAI-1) activity and factor VII were assessed in a sample of men 50-59 years living in France (n = 7050) and Northern Ireland (n = 2374). After adjustment for age, body mass index, smoking status, educational level, country, alcohol drinking and hypolipidaemic drug treatment, untreated hypertensive subjects had higher levels of total cholesterol, triglyceride, apoproteins A-I and B and PAI-I activity than normotensive subjects. On univariate analysis, diuretics decreased total and HDL-cholesterol and apoproteins A-I and B; those differences remained after multivariate adjustment. Treatment with beta-blockers decreased total and HDL-cholesterol, apoprotein A-I and LpA-I, and this effect remained after multivariate adjustment. Calcium channel blockers decreased total cholesterol and apoproteins A-I and B; those differences remained significant after multivariate adjustment. ACE inhibitors decreased total cholesterol, triglycerides, apoprotein B and LpE:B; and this effect remained after multivariate adjustment. Analysis of the subjects on monotherapy showed beta-blockers to decrease total cholesterol and HDL parameters and angiotensin-converting enzyme (ACE) inhibitors to decrease low-density lipoprotein (LDL)-related parameters, while no effect was found for the other antihypertensive drugs. CONCLUSIONS: Hypertensive status is associated with an unfavourable lipid and haemostatic profile in middle-aged men. Antihypertensive treatment with beta-blockers decreases HDL parameters, whereas treatment with ACE inhibitors appears to decrease total cholesterol and LDL-related parameters.


Asunto(s)
Antihipertensivos/uso terapéutico , Hemostasis , Hipertensión/sangre , Hipertensión/tratamiento farmacológico , Lípidos/sangre , Inhibidores de la Enzima Convertidora de Angiotensina/uso terapéutico , Bloqueadores de los Canales de Calcio/uso terapéutico , Colesterol/sangre , HDL-Colesterol/sangre , Diuréticos/uso terapéutico , Humanos , Lipoproteínas LDL/sangre , Masculino , Persona de Mediana Edad
19.
Br J Surg ; 87(6): 734-41, 2000 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-10848850

RESUMEN

BACKGROUND: Complex limb trauma often involves combined arterial and venous injury, and the resultant ischaemia-reperfusion injury (IRI) causes both local and remote organ injury. This study assessed the influence of the timing of restoration of venous drainage on IRI. METHODS: Male New Zealand white rabbits (n = 36) were randomized into six groups: sham operation (group 1) and unilateral hind limb arterial and venous occlusion for 1 h followed by no reflow for 2 h (group 2), arterial and venous reflow for 2 h (group 3), arterial reflow alone for 2 h (group 4), arterial reflow alone for 1 h followed by arterial and venous (delayed) reflow for a further 1 h (group 5), and pretreatment with an enteral combination antioxidant before occlusion of both artery and vein and delayed venous reflow (group 6). Plasma hydroperoxide (HPO) and glutathione peroxidase concentration, hind limb skeletal muscle and lung tissue wet : dry weight ratios and myeloperoxidase (MPO) concentration were measured. RESULTS: The plasma HPO level in the femoral vein effluent was significantly greater after delayed venous reflow (mean(s.e.m.) 2. 02(0.54) micromol/l) than in control animals (0.98(0.10) micromol/l) (P < 0.05). There was also a significantly greater tissue wet : dry weight ratio after delayed venous reflow than in controls, in skeletal muscle (mean(s.e.m.) 6.89(0.14) versus 5.34(0.54); P < 0. 05) and lung (9.20(1.14) versus 7.23(0.38); P < 0.05) tissue. Lung tissue MPO activity was significantly greater after delayed venous reflow compared with controls (3.20(0.28) versus 1.86(0.14) units/g; P < 0.005), and also in comparison to simultaneous arterial and venous reflow (2.40(0.24) units/g; P < 0.05). In the antioxidant pretreatment group there was no significant increase in plasma HPO concentration, tissue MPO level or tissue wet : dry weight ratio compared with the control group. CONCLUSION: In combined major arterial and venous injury of the limb, delayed restoration of venous drainage leads to significantly greater local skeletal muscle injury and remote neutrophil-mediated lung injury. These results support the clinical rationale for early restoration not only of arterial inflow but also venous drainage by means of intraluminal shunts.


Asunto(s)
Extremidades/irrigación sanguínea , Daño por Reperfusión/etiología , Animales , Constricción , Extremidades/lesiones , Extremidades/cirugía , Arteria Femoral/fisiología , Vena Femoral/fisiología , Glutatión Peroxidasa/sangre , Peróxido de Hidrógeno/sangre , Recuento de Leucocitos , Masculino , Neutrófilos , Peroxidasa/metabolismo , Conejos , Factores de Tiempo
20.
J Paediatr Child Health ; 36(3): 221-5, 2000 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-10849220

RESUMEN

OBJECTIVE: To perform a multicentre follow-up study to determine if previously identified markers of serious illness in early infancy were robust and statistically reliable. METHODS: Infants aged 1 week to 26 weeks presenting to the Emergency Departments of the Royal Children's Hospital and two Melbourne metropolitan hospitals were seen over a 12-month period. Eleven clinical markers as well as their temperature were documented by nursing staff and resident medical officers. Serious illness was defined if infants had a positive body fluid bacterial culture, a positive chest X-ray or if significant treatment was required in hospital. The predictive values, sensitivity and specificity for the individual and the best combination of clinical markers were determined. RESULTS: Assessments (3806) were performed with 312 infants being assessed as seriously ill (8.2%). The combination of either drowsiness on history or examination, pallor on history or examination, breathing difficulty (chest wall recession), temperature above 38 degrees C and a lump being present, identified 82.5% of all babies deemed subsequently to be seriously ill. The positive predictive value of an infant who was febrile, drowsy and pale on examination was 70.7% (previous study 74%). CONCLUSIONS: This study confirmed the high individual predictive value of arousal variables, pallor, and chest wall recession, especially when associated with fever, reaffirming their utility in the recognition of serious illness in infants under 6 months of age.


Asunto(s)
Biomarcadores/análisis , Enfermedades del Recién Nacido/diagnóstico , Anomalías Congénitas/diagnóstico , Anomalías Congénitas/terapia , Enfermedad Crítica , Enfermedades del Sistema Digestivo/diagnóstico , Enfermedades del Sistema Digestivo/terapia , Femenino , Estudios de Seguimiento , Humanos , Lactante , Recién Nacido , Enfermedades del Recién Nacido/terapia , Infecciones/diagnóstico , Infecciones/terapia , Masculino , Valor Predictivo de las Pruebas , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Índice de Severidad de la Enfermedad , Virosis/diagnóstico , Virosis/terapia
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