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1.
Artigo em Inglês | MEDLINE | ID: mdl-34500309

RESUMO

Lipid bioactivity is a result of direct action and the action of lipid mediators including oxylipins, endocannabinoids, bile acids and steroids. Understanding the factors contributing to biological variation in lipid mediators may inform future approaches to understand and treat complex metabolic diseases. This research aims to determine the contribution of genetic and environmental influences on lipid mediators involved in the regulation of inflammation and energy metabolism. This study recruited 138 monozygotic (MZ) and dizygotic (DZ) twins aged 18-65 years and measured serum oxylipins, endocannabinoids, bile acids and steroids using liquid chromatography mass-spectrometry (LC-MS). In this classic twin design, the similarities and differences between MZ and DZ twins are modelled to estimate the contribution of genetic and environmental influences to variation in lipid mediators. Heritable lipid mediators included the 12-lipoxygenase products 12-hydroxyeicosatetraenoic acid [0.70 (95% CI: 0.12,0.82)], 12-hydroxyeicosatetraenoic acid [0.73 (95% CI: 0.30,0.83)] and 14­hydroxy-docosahexaenoic acid [0.51 (95% CI: 0.07,0.71)], along with the endocannabinoid docosahexaenoy-lethanolamide [0.52 (95% CI: 0.15,0.72)]. For others such as 13-hydroxyoctadecatrienoic acid and lithocholic acid the contribution of environment to variation was stronger. With increased understanding of lipid mediator functions in health, it is important to understand the factors contributing to their variance. This study provides a comprehensive analysis of lipid mediators and extends pre-existing knowledge of the genetic and environmental influences on the human lipidome.


Assuntos
Ácidos e Sais Biliares/sangue , Endocanabinoides/sangue , Ácidos Graxos Ômega-3/sangue , Metabolismo dos Lipídeos/genética , Oxilipinas/sangue , Esteroides/sangue , Ácido 12-Hidroxi-5,8,10,14-Eicosatetraenoico/sangue , Ácido 12-Hidroxi-5,8,10,14-Eicosatetraenoico/genética , Adolescente , Adulto , Idoso , Ácidos e Sais Biliares/genética , Desidroepiandrosterona/sangue , Desidroepiandrosterona/genética , Ácidos Docosa-Hexaenoicos/sangue , Ácidos Docosa-Hexaenoicos/genética , Ácido Eicosapentaenoico/análogos & derivados , Ácido Eicosapentaenoico/sangue , Ácido Eicosapentaenoico/genética , Endocanabinoides/genética , Ácidos Graxos Ômega-3/genética , Feminino , Interação Gene-Ambiente , Humanos , Masculino , Pessoa de Meia-Idade , Gêmeos Dizigóticos/genética , Gêmeos Monozigóticos/genética , Adulto Jovem
3.
Mol Pharmacol ; 82(6): 1194-204, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22973060

RESUMO

Iron is a biologically essential metal, but excess iron can cause damage to the cardiovascular and nervous systems. We examined the effects of extracellular Fe²âº on permeation and gating of Ca(V)3.1 channels stably transfected in HEK293 cells, by using whole-cell recording. Precautions were taken to maintain iron in the Fe²âº state (e.g., use of extracellular ascorbate). With the use of instantaneous I-V currents (measured after strong depolarization) to isolate the effects on permeation, extracellular Fe²âº rapidly blocked currents with 2 mM extracellular Ca²âº in a voltage-dependent manner, as described by a Woodhull model with K(D) = 2.5 mM at 0 mV and apparent electrical distance δ = 0.17. Extracellular Fe²âº also shifted activation to more-depolarized voltages (by ∼10 mV with 1.8 mM extracellular Fe²âº) somewhat more strongly than did extracellular Ca²âº or Mg²âº, which is consistent with a Gouy-Chapman-Stern model with surface charge density σ = 1 e(-)/98 Ų and K(Fe) = 4.5 M⁻¹ for extracellular Fe²âº. In the absence of extracellular Ca²âº (and with extracellular Na⁺ replaced by TEA), Fe²âº carried detectable, whole-cell, inward currents at millimolar concentrations (73 ± 7 pA at -60 mV with 10 mM extracellular Fe²âº). With a two-site/three-barrier Eyring model for permeation of Ca(V)3.1 channels, we estimated a transport rate for Fe²âº of ∼20 ions/s for each open channel at -60 mV and pH 7.2, with 1 µM extracellular Fe²âº (with 2 mM extracellular Ca²âº). Because Ca(V)3.1 channels exhibit a significant "window current" at that voltage (open probability, ∼1%), Ca(V)3.1 channels represent a likely pathway for Fe²âº entry into cells with clinically relevant concentrations of extracellular Fe²âº.


Assuntos
Canais de Cálcio Tipo T/metabolismo , Cálcio/metabolismo , Compostos Ferrosos/metabolismo , Compostos Ferrosos/farmacologia , Transferrina/metabolismo , Bário/metabolismo , Linhagem Celular , Células HEK293 , Humanos , Ativação do Canal Iônico/efeitos dos fármacos , Magnésio/metabolismo , Potenciais da Membrana/efeitos dos fármacos , Técnicas de Patch-Clamp/métodos
4.
J Infect ; 65(3): 197-213, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22634599

RESUMO

OBJECTIVES: The Typhoid and Paratyphoid Reference Group (TPRG) was convened by the Health Protection Agency (HPA) and the Chartered Institute of Environmental Health (CIEH) to revise guidelines for public health management of enteric fever. This paper presents the new guidelines for England and their rationale. METHODS: Methods include literature reviews including grey literature such as audit data and case studies; analysis of enhanced surveillance data from England, Wales and Northern Ireland; review of clearance and screening schedules in use in other non-endemic areas; and expert consensus. RESULTS: The evidence and principles underpinning the new guidance are summarised. Significant changes from previous guidance include: • Algorithms to guide risk assessment and management, based on risk group and travel history; • Outline of investigation of non-travel cases; • Simplified microbiological clearance schedules for cases and contacts; • Targeted co-traveller screening and a "warn and inform" approach for contacts; • Management of convalescent and chronic carriers. CONCLUSIONS: The guidelines were launched in February 2012. Feedback has been positive: the guidelines are reported to be clear, systematic, practical and risk-based. An evaluation of the guidelines is outlined and will add to the evidence base. There is potential for simplification and consistency between international guidelines.


Assuntos
Febre Paratifoide , Saúde Pública , Febre Tifoide , Humanos , Doenças Endêmicas , Inglaterra , Febre Paratifoide/prevenção & controle , Saúde Pública/métodos , Saúde Pública/normas , Fatores de Risco , Viagem , Febre Tifoide/prevenção & controle
5.
J Gen Physiol ; 132(2): 223-38, 2008 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-18663131

RESUMO

We examined the concentration dependence of currents through Ca(V)3.1 T-type calcium channels, varying Ca(2+) and Ba(2+) over a wide concentration range (100 nM to 110 mM) while recording whole-cell currents over a wide voltage range from channels stably expressed in HEK 293 cells. To isolate effects on permeation, instantaneous current-voltage relationships (IIV) were obtained following strong, brief depolarizations to activate channels with minimal inactivation. Reversal potentials were described by P(Ca)/P(Na) = 87 and P(Ca)/P(Ba) = 2, based on Goldman-Hodgkin-Katz theory. However, analysis of chord conductances found that apparent K(d) values were similar for Ca(2+) and Ba(2+), both for block of currents carried by Na(+) (3 muM for Ca(2+) vs. 4 muM for Ba(2+), at -30 mV; weaker at more positive or negative voltages) and for permeation (3.3 mM for Ca(2+) vs. 2.5 mM for Ba(2+); nearly voltage independent). Block by 3-10 muM Ca(2+) was time dependent, described by bimolecular kinetics with binding at approximately 3 x 10(8) M(-1)s(-1) and voltage-dependent exit. Ca(2+)(o), Ba(2+)(o), and Mg(2+)(o) also affected channel gating, primarily by shifting channel activation, consistent with screening a surface charge of 1 e(-) per 98 A(2) from Gouy-Chapman theory. Additionally, inward currents inactivated approximately 35% faster in Ba(2+)(o) (vs. Ca(2+)(o) or Na(+)(o)). The accelerated inactivation in Ba(2+)(o) correlated with the transition from Na(+) to Ba(2+) permeation, suggesting that Ba(2+)(o) speeds inactivation by occupying the pore. We conclude that the selectivity of the "surface charge" among divalent cations differs between calcium channel families, implying that the surface charge is channel specific. Voltage strongly affects the concentration dependence of block, but not of permeation, for Ca(2+) or Ba(2+).


Assuntos
Bário/farmacologia , Canais de Cálcio Tipo T/metabolismo , Cálcio/farmacologia , Ativação do Canal Iônico/efeitos dos fármacos , Magnésio/farmacologia , Sódio/farmacologia , Bário/metabolismo , Cálcio/metabolismo , Linhagem Celular , Relação Dose-Resposta a Droga , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/metabolismo , Humanos , Magnésio/metabolismo , Potenciais da Membrana/fisiologia , Permeabilidade , Sódio/metabolismo
6.
J Gen Physiol ; 132(2): 239-50, 2008 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-18663132

RESUMO

Ni(2+) inhibits current through calcium channels, in part by blocking the pore, but Ni(2+) may also allosterically affect channel activity via sites outside the permeation pathway. As a test for pore blockade, we examined whether the effect of Ni(2+) on Ca(V)3.1 is affected by permeant ions. We find two components to block by Ni(2+), a rapid block with little voltage dependence, and a slow block most visible as accelerated tail currents. Rapid block is weaker for outward vs. inward currents (apparent K(d) = 3 vs. 1 mM Ni(2+), with 2 mM Ca(2+) or Ba(2+)) and is reduced at high permeant ion concentration (110 vs. 2 mM Ca(2+) or Ba(2+)). Slow block depends both on the concentration and on the identity of the permeant ion (Ca(2+) vs. Ba(2+) vs. Na(+)). Slow block is 2-3x faster in Ba(2+) than in Ca(2+) (2 or 110 mM), and is approximately 10x faster with 2 vs. 110 mM Ca(2+) or Ba(2+). Slow block is orders of magnitude slower than the diffusion limit, except in the nominal absence of divalent cations ( approximately 3 muM Ca(2+)). We conclude that both fast and slow block of Ca(V)3.1 by Ni(2+) are most consistent with occlusion of the pore. The exit rate of Ni(2+) for slow block is reduced at high Ni(2+) concentrations, suggesting that the site responsible for fast block can "lock in" slow block by Ni(2+), at a site located deeper within the pore. In contrast to the complex pore block observed for Ca(V)3.1, inhibition of Ca(V)3.2 by Ni(2+) was essentially independent of voltage, and was similar in 2 mM Ca(2+) vs. Ba(2+), consistent with inhibition by a different mechanism, at a site outside the pore.


Assuntos
Bloqueadores dos Canais de Cálcio/farmacologia , Canais de Cálcio Tipo T/metabolismo , Níquel/farmacologia , Bário/farmacologia , Cálcio/farmacologia , Linhagem Celular , Relação Dose-Resposta a Droga , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/metabolismo , Humanos , Ativação do Canal Iônico , Potenciais da Membrana/efeitos dos fármacos
7.
Pediatrics ; 121(6): e1715-22, 2008 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18519475

RESUMO

OBJECTIVE: The aim of this study was to investigate the effect of catch-up growth occurring at different stages of childhood on glucose levels and beta-cell function at 7 years of age. METHODS: Oral glucose tolerance tests were performed on 152 7-year-old children. Anthropometric data were available from birth to 7 years of age. Children were split into catch-up, catch-down, and normal-growth groups on the basis of growth rates between birth and 1 year, birth and 5 years, and birth and 7 years. Fasting and 30- and 120-minute blood samples collected during the oral glucose tolerance tests were assayed for glucose, insulin, proinsulin, and des-31,32-proinsulin levels, and area-under-the-curve values were calculated. RESULTS: Children with catch-up growth between birth and 5 years or birth and 7 years had greater area-under-the-curve insulin levels than the children with catch-down growth. Children with catch-up growth only between birth and 7 years exhibited higher proinsulin levels and a greater insulin secretory response to glucose than those who experienced catch-up growth between both birth and 1 year and birth and 7 years of age. Low birth weight children with no catch-up growth between birth and 7 years had the highest glucose and lowest insulinogenic index levels, whereas children with high birth weight and catch-up growth had the highest insulin levels. CONCLUSIONS: Extremes of birth weight in conjunction with extremes of postnatal growth are all detrimental to childhood metabolism. The negative metabolic effects of catch-up growth between birth and 7 years may be attenuated if catch-up growth also occurs between birth and 1 year of age.


Assuntos
Desenvolvimento Infantil/fisiologia , Crescimento/fisiologia , Células Secretoras de Insulina/fisiologia , Criança , Pré-Escolar , Feminino , Teste de Tolerância a Glucose , Humanos , Lactente , Recém-Nascido , Masculino
9.
Injury ; 38(11): 1305-7, 2007 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-17640642

RESUMO

There is no published work addressing the safety of driving with a below knee cast. We assessed the effect of below knee casts on driving ability and therefore safety. The study gives doctors the evidence base on which to appropriately advise patients regarding driving safety in below knee plaster casts. With the help of the regional Police Force Training and Recruitment Centre, two subjects were assessed in a variety of below knee casts in both manual and automatic vehicles. One of the subjects was a highly trained police driver the other one of the medical authors. All assessments were carried out by a trained police advanced driver. With the exception of a left sided below knee cast in a automatic transmission vehicle all types of below knee casts were deemed a significant impairment and therefore unsafe to drive in. The DVLA has no guidelines regarding driving with a plaster cast. The decision of whether or not a patient can drive safely can now be taken out of the hands of the medical practitioner.


Assuntos
Condução de Veículo/normas , Moldes Cirúrgicos , Perna (Membro) , Segurança , Condução de Veículo/legislação & jurisprudência , Humanos
10.
J Gen Physiol ; 124(6): 631-40, 2004 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-15572343

RESUMO

Classical electrophysiology and contemporary crystallography suggest that the activation gate of voltage-dependent channels is on the intracellular side, but a more extracellular "pore gate" has also been proposed. We have used the voltage dependence of block by extracellular Y(3+) as a tool to locate the activation gate of the alpha1G (Ca(V)3.1) T-type calcium channel. Y(3+) block exhibited no clear voltage dependence from -40 to +40 mV (50% block at 25 nM), but block was relieved rapidly by stronger depolarization. Reblock of the open channel, reflected in accelerated tail currents, was fast and concentration dependent. Closed channels were also blocked by Y(3+) at a concentration-dependent rate, only eightfold slower than open-channel block. When extracellular Ca(2+) was replaced with Ba(2+), the rate of open block by Y(3+) was unaffected, but closed block was threefold faster than in Ca(2+), suggesting the slower closed-block rate reflects ion-ion interactions in the pore rather than an extracellularly located gate. Since an extracellular blocker can rapidly enter the closed pore, the primary activation gate must be on the intracellular side of the selectivity filter.


Assuntos
Canais de Cálcio Tipo T/metabolismo , Cálcio/metabolismo , Permeabilidade da Membrana Celular/fisiologia , Ativação do Canal Iônico/fisiologia , Potenciais da Membrana/fisiologia , Ítrio/farmacologia , Animais , Canais de Cálcio Tipo T/efeitos dos fármacos , Linhagem Celular , Permeabilidade da Membrana Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Humanos , Líquido Intracelular/metabolismo , Ativação do Canal Iônico/efeitos dos fármacos , Rim , Potenciais da Membrana/efeitos dos fármacos , Ratos
11.
Brain ; 127(Pt 8): 1723-30, 2004 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-15201191

RESUMO

To investigate the aetiology of chronic idiopathic axonal polyneuropathy (CIAP), 50 consecutive patients were compared with 50 control subjects from the same region. There were 22 patients with painful neuropathy and 28 without pain, 26 with sensory neuropathy and 24 with sensory and motor neuropathy. The typical picture was a gradually progressive sensory or sensory and motor neuropathy. It caused mild or sometimes moderate disability, and reduced the quality of life. There was no evidence that alcohol, venous insufficiency, arterial disease or antibodies to peripheral nerve antigens played a significant part. There was a possible history of peripheral neuropathy in the first or second-degree relatives of six patients and no controls (P = 0.01), and claw toes were present in 12 patients and four controls (P = 0.03). Thirty-two per cent of the patients and 14% of the controls had impaired glucose tolerance or fasting hyperglycaemia but, after adjusting for age and sex, the difference was not significant (P = 0.45), even in the painful neuropathy subgroup. The mean (SD) fasting insulin concentrations were significantly (P = 0.01) higher in the patients [75.9 (44.4) mmol/l] than the controls [47.3 (37.9) mmol/l], and the mean was higher still in the painful neuropathy subgroup [92.2 (37.1) mmol/l] (P < 0.0001). However, insulin resistance as assessed using the homeostasis model assessment formula was not significantly greater in the patients, even in those with pain, than the controls. After adjustment for body mass index as well as age and sex, there was no significant difference in the serum cholesterol concentrations, but there were significantly higher triglyceride concentrations in the patients [mean 1.90 (1.41) mmol/l] than the controls [mean 1.25 (0.79] mmol/l) (P = 0.02). In the patients with painful peripheral neuropathy, the mean triglyceride concentration was 2.37 (1.72), which was even more significantly greater compared with the controls (P = 0.003). In conclusion, CIAP is a heterogeneous condition. A logistic regression analysis identified environmental toxin exposure and hypertriglyceridaemia, but not glucose intolerance or alcohol overuse as significant risk factors that deserve further investigation as possible causes of CIAP.


Assuntos
Polineuropatias/etiologia , Idoso , Antropometria , Ácido Ascórbico/sangue , Autoanticorpos/sangue , Estudos de Casos e Controles , Avaliação da Deficiência , Feminino , Intolerância à Glucose/complicações , Substâncias Perigosas/toxicidade , Humanos , Hipertrigliceridemia/complicações , Resistência à Insulina , Masculino , Pessoa de Meia-Idade , Dor/etiologia , Polineuropatias/genética , Polineuropatias/fisiopatologia , Qualidade de Vida , Fatores de Risco , Vitamina E/sangue
12.
J Neuroimmunol ; 149(1-2): 160-6, 2004 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-15020076

RESUMO

Recent reports have contained conflicting results on the relationship between antecedent Haemophilus influenzae infection and Guillain-Barré syndrome (GBS). To investigate the prevalence of H. influenzae infection in GBS patients in a British population, we carried out a retrospective study with 62 consecutive GBS patients and 63 normal controls of similar age and sex. Whole bacteria of both encapsulated and nonencapsulated strains of H. influenzae were employed as antigens in an enzyme-linked immunosorbent assay (ELISA) for anti-H. influenzae IgG, IgM and IgA antibodies. Elevated antibodies of two or three classes were found in one GBS patient and none in the normal controls. Six GBS patients had IgG antibodies against nonencapsulated H. influenzae compared with only one in the normal control group (p=0.06). Western blot for IgG antibody showed that all the sera with IgG antibodies recognized the lipopolysaccharide (LPS) of both strains of H. influenzae. Antiganglioside GM1 antibody was not associated with anti-H. influenzae antibody in our study. Absorption with encapsulated or nonencapsulated H. influenzae, Campylobacter jejuni and Escherichia coli before testing on Western blot showed that only nonencapsulated H. influenzae absorbed the anti-LPS antibodies. In conclusion, there is a possible but rare association of GBS with nonencapsulated H. influenzae in the UK.


Assuntos
Síndrome de Guillain-Barré/microbiologia , Infecções por Haemophilus/complicações , Haemophilus influenzae/patogenicidade , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Anticorpos Antibacterianos/sangue , Western Blotting/métodos , Criança , Pré-Escolar , Ensaio de Imunoadsorção Enzimática/métodos , Feminino , Gangliosidose GM1/imunologia , Síndrome de Guillain-Barré/imunologia , Infecções por Haemophilus/imunologia , Haemophilus influenzae/isolamento & purificação , Humanos , Imunoglobulinas/sangue , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos
13.
J Neurol Neurosurg Psychiatry ; 74(11): 1555-61, 2003 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-14617715

RESUMO

OBJECTIVE: Multifocal motor neuropathy with persistent conduction blocks is classically described as a chronic neuropathy with progressive onset, and acute forms have not previously been characterised. We report four cases of severe motor impairment with acute and generalised onset and with persistent motor conduction blocks. PATIENTS AND RESULTS: An acute tetraparesis with diffuse areflexia but little or no sensory disturbance was the clinical picture. Serial electrophysiological tests showed persistent multifocal motor conduction blocks with absent F waves in most tested motor nerves. No or minor abnormalities of the sensory nerve action potentials were observed. Cerebrospinal fluid contained normal or mildly increased protein levels (<1 g/l) without cells. Campylobacter jejuni serology was negative in three patients and consistent with past infection in one patient. Anti-ganglioside antibodies were positive in three patients. A five day course of intravenous immunoglobulins produced nearly complete symptom resolution in three patients and was ineffective in one patient. CONCLUSION: Because of the persistence of multifocal motor conduction blocks for several weeks or months as the isolated electrophysiological feature, these cases could not be consistent with Guillain-Barré syndrome or chronic inflammatory demyelinating polyneuropathy. They suggest an original variant of multifocal motor neuropathy with an acute and generalised initial presentation and persistent motor conduction blocks affecting all four limbs.


Assuntos
Doença dos Neurônios Motores/fisiopatologia , Condução Nervosa , Paresia/etiologia , Doença Aguda , Adulto , Feminino , Humanos , Imunoglobulinas Intravenosas/uso terapêutico , Masculino , Doença dos Neurônios Motores/complicações , Doença dos Neurônios Motores/tratamento farmacológico
14.
Neurology ; 61(9): 1282-4, 2003 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-14610140

RESUMO

The authors recruited 19 nonambulant patients with Guillain-Barré syndrome into a pilot, double-blind, randomized, placebo-controlled safety trial of interferon beta 1a (IFN[beta]-1a) (Rebif). Participants received IFN[beta]-1a or placebo subcutaneously three times weekly, 22 microg for the first week and then 44 microg for up to 24 weeks, in addition to IV immunoglobulin (IVIg). IFN[beta] did not have any unexpected interaction with IVIg and there was no significant difference in rate of improvement.


Assuntos
Síndrome de Guillain-Barré/tratamento farmacológico , Interferon beta/uso terapêutico , Proteínas Recombinantes/uso terapêutico , Citocinas/sangue , Avaliação da Deficiência , Relação Dose-Resposta a Droga , Fadiga/induzido quimicamente , Feminino , Síndrome de Guillain-Barré/imunologia , Humanos , Imunoglobulinas Intravenosas/uso terapêutico , Interferon beta-1a , Interferon beta/efeitos adversos , Linfopenia/induzido quimicamente , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Proteínas Recombinantes/efeitos adversos , Resultado do Tratamento
15.
J Clin Endocrinol Metab ; 87(9): 4252-6, 2002 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-12213880

RESUMO

The aim of this study was to determine the contribution of birth weight and gestational age to glucose tolerance in premature neonates. The study group consisted of 100 premature and/or small-for-gestational age infants. Anthropometric measurements were performed both at birth and at the time of a standardized milk feed carried out at 19.6 +/- 12.1 d (range, 1-65 d) after birth. Fasting and postprandial glucose and insulin levels were measured. Birth weight, as a proxy mirror of the intrauterine environment, was found to influence the glucose concentration following a standardized milk feed (beta = -0.46; P = 0.01 for birth weight z-score with 60-min glucose level), whereas gestational age did not. Small-for-gestational age neonates had higher 60-min insulin levels than appropriate-for-gestational age neonates (115.4 +/- 9.5 vs. 68.4 +/- 14.2; P < 0.05) despite similar glucose levels. Neonates born of mothers who were on antihypertensive treatment were smaller and had a higher insulin secretory response than neonates from normotensive mothers. Postnatal growth velocity (kilograms per day) correlated with birth weight (beta = -0.65; P < 0.0001) and insulin resistance (beta = -0.31; P = 0.0004), independently of each other. This study shows that glucose tolerance of the neonate is determined by weight attained at birth irrespective of gestational age and that maternal blood pressure may influence insulin sensitivity of the newborn. Furthermore, catch-up growth in neonates is determined by birth weight and insulin sensitivity.


Assuntos
Glicemia/metabolismo , Teste de Tolerância a Glucose , Recém-Nascido Prematuro/fisiologia , Recém-Nascido Pequeno para a Idade Gestacional/fisiologia , Insulina/sangue , Útero/fisiologia , Peso ao Nascer , Constituição Corporal , Jejum , Feminino , Glucose/metabolismo , Humanos , Recém-Nascido , Gravidez
16.
Int J Obes Relat Metab Disord ; 25(8): 1196-205, 2001 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-11477505

RESUMO

OBJECTIVE: The effects of free fatty acids (FFA), leptin, tumour necrosis factor (TNF) alpha and body fat distribution on in vivo oxidation of a glucose load were studied in two South African ethnic groups. DESIGN AND MEASUREMENTS: Anthropometric and various metabolic indices were measured at fasting and during a 7 h oral glucose tolerance test (OGTT). Body composition was measured using bioelectrical impedance analysis and subcutaneous and visceral fat mass was assessed using a five- and two-level CT-scan respectively. Glucose oxidation was evaluated by measuring the ratio of (13)CO(2) to (12)CO(2) in breath following ingestion of 1-(13)C-labelled glucose. SUBJECTS: Ten lean black women (LBW), ten obese black women (OBW), nine lean white women (LWW) and nine obese white women (OWW) were investigated after an overnight fast. RESULTS: Visceral fat levels were significantly higher (P<0.01) in obese white than black women, despite similar body mass indexes (BMIs). There were no ethnic differences in glucose oxidation however; in the lean subjects of both ethnic groups the area under the curve (AUC) was higher than in obese subjects (P<0.05 for both) and was found to correlate negatively with weight (r=-0.69, P<0.01) after correcting for age. Basal TNF alpha concentrations were similar in all groups. Percentage suppression of FFAs at 30 min of the OGTT was 24+/-12% in OWW and -38+/-23% (P<0.05) in OBW, ie the 30 min FFA level was higher than the fasting level in the latter group. AUC for FFAs during the late postprandial period (120--420 min) was significantly higher in OWW than OBW (P<0.01) and LWW (P<0.01) and correlated positively with visceral fat mass independent of age (r=0.78, P<0.05) in the OWW only. Leptin levels were higher (P<0.01) both at fasting and during the course of the OGTT in obese women from both ethnic groups compared to the lean women. CONCLUSIONS: Glucose oxidation is reduced in obese subjects of both ethnic groups; inter- and intra-ethnic differences were observed in visceral fat mass and FFA production and it is possible that such differences may play a role in the differing prevalences of obesity-related disorders that have been reported in these two populations.


Assuntos
Tecido Adiposo/anatomia & histologia , Negro ou Afro-Americano , Peso Corporal , Ácidos Graxos não Esterificados/biossíntese , Glucose/metabolismo , Obesidade/metabolismo , População Branca , Adulto , Área Sob a Curva , População Negra , Composição Corporal , Testes Respiratórios , Isótopos de Carbono , Jejum , Feminino , Teste de Tolerância a Glucose , Humanos , Leptina , África do Sul/epidemiologia , Fator de Necrose Tumoral alfa
17.
J Clin Endocrinol Metab ; 86(7): 3296-303, 2001 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-11443204

RESUMO

Abnormalities observed in intermediary metabolism may be related to the pathogenesis of obesity-related diseases such as type 2 diabetes. Glycerol and lactate production was estimated in the sc adipose tissue of two anatomical regions of 10 lean (LW), 10 obese (OW), and 10 matched diabetic (DW) black urban women. This was done with the sc microdialysis technique and combined with adipose tissue blood flow (ATBF) rates calculated from (133)Xe clearance. Biochemical measurements were made in the postabsorptive and postprandial state. Bioimpedance and computed tomography scans were used to define body composition. DW present with more visceral fat (DW, 138 +/- 5.0; OW, 66.6 +/- 5.0 cm; P < 0.01). This was associated with elevated free testosterone levels (DW, 1.21 +/- 0.1; OW, 0.75 +/- 0.1 nmol/L; P < 0.05). The fasting FFA, glycerol, and lactate levels increased across the three groups (LW < OW < DW). During the oral glucose tolerance test, glucose levels were elevated in DW, with higher insulin levels [0 h: DW, 207 +/- 8.6; OW, 100 +/- 7.2 pmol/L (P < 0.01); 1 h: DW, 410 +/- 15.2; OW, 320 +/- 10.9 pmol/L (P < 0.05)], but with a flat Cpeptide response (1 h: DW, 932 +/- 40; OW, 1764 +/- 40 pmol/L; P < 0.05). Plasma lactate levels increased significantly in LW and OW at 1 h (P < 0.001), but remained lower in LW vs. OW for all time points. ATBF was highest in LW [abdominal, 0 h: DW, 4.5 +/- 0.2; OW, 1.7 mL/100 g.min (P < 0.01); femoral, 0 h: DW, 3.4 +/- 0.2; OW, 1.8 +/- 0.3 mL/100 g.min (P < 0.01)]. ATBF did not increase in DW during the oral glucose tolerance test. Glycerol release (GR) was used to assess the lipolytic rate and was highest in LW in the abdominal area [0 h: LW, 1.7 +/- 0.2; OW, 1.1 +/- 0.2 micromol/kg.min (P < 0.05); DW, 0.78 +/- 0.05 micromol/kg.min (P < 0.05 vs. OW)]. By contrast, GR was higher in the femoral area of OW (0 h: OW, 1.6 +/- 0.2; LW, 1.15 +/- 0.1 micromol/kg.min; P < 0.05). Regional differences were observed for GR in both OW and DW (femoral > abdominal). Lactate release (LR) was low in DW [abdominal, 0 h: DW, 3.5 +/- 0.4; OW, 7.8 +/- 1.0 micromol/kg.min (P < 0.001); femoral, 0 h: DW, 3.1 +/- 0.3; OW, 9.0 +/- 0.9 micromol/kg.min (P < 0.001)]. LR was appropriately low for body fat mass in LW, with a brisk increase between 0 and 1.5 h. A negative correlation exists between GR (abdominal area) and insulin levels in the postabsorptive state (P < 0.0001). In conclusion, 1) the fasting lipolytic rate is associated with insulin levels; 2) OW and DW have more adipose tissue insulin resistance than LW; 3) OW and DW have a brisker lipolysis in the femoral area; and 4) in DW, higher visceral mass is associated with elevated free testosterone and FFA concentrations. Obesity in the black population is therefore characterized by a marked degree of adipose tissue lipolysis. This degree of resistance together with increasing body fat mass may predispose the obese women to developing type 2 diabetes. Once this disease is established, the onset of adipose tissue vascular insulin resistance will sustain ongoing insulin resistance, even in the presence of relative insulinopenia.


Assuntos
Tecido Adiposo/metabolismo , Diabetes Mellitus Tipo 2/fisiopatologia , Diabetes Mellitus/fisiopatologia , Glicerol/sangue , Ácido Láctico/sangue , Obesidade/fisiopatologia , Tecido Adiposo/irrigação sanguínea , Adulto , População Negra , Composição Corporal , Peptídeo C/sangue , Ácidos Graxos não Esterificados/sangue , Feminino , Alimentos , Teste de Tolerância a Glucose , Humanos , África do Sul , Testosterona/sangue , População Urbana
18.
J Lipid Res ; 42(5): 760-7, 2001 May.
Artigo em Inglês | MEDLINE | ID: mdl-11352983

RESUMO

There is a higher prevalence of ischemic heart disease (IHD) in South African white than black women. The objective of this study was to determine biochemical explanations for this prevalence. The study group contained 15 obese black women (OBW) and 14 obese white women (OWW), all premenopausal, who were examined after an overnight fast. Anthropometric measurements and blood concentrations of glucose, non-esterified fatty acids (NEFAs), catecholamines, plasminogen activator inhibitor-1, C-peptide, proinsulin, lipograms, cortisol, growth hormone, and post-heparin lipoprotein lipase activity were measured during an oral glucose tolerance test (OGTT). Body composition was measured using bioelectrical impedance analysis, and subcutaneous and visceral fat mass were assessed with CT-scans. Visceral fat area was higher in OWW (139.7 +/- 10.7 cm(2)) than in OBW (72.3 +/- 3.9 cm(2)) (P < 0.01), as were fasting and 3 h triglyceride concentrations (P < 0.05 for all). OWW also had higher NEFA levels than OBW at 3 and 4 h compared with OBW (P < 0.05 for both). Fasting cortisol (266 +/- 24 vs. 197 +/- 19 nmol/l; P < 0.05) was higher in OWW than in OBW. These data demonstrate that OWW have higher visceral fat mass than OBW, which may lead to a more atherogenic fasting and postprandial lipid profile. The higher cortisol levels of the OWW may promote visceral fat deposition.


Assuntos
População Negra , Índice de Massa Corporal , Metabolismo dos Lipídeos , Isquemia Miocárdica/etiologia , Obesidade/etnologia , Obesidade/metabolismo , População Branca , Adulto , Área Sob a Curva , Glicemia/metabolismo , Composição Corporal , Peptídeo C/sangue , Peptídeo C/metabolismo , Ácidos Graxos não Esterificados/metabolismo , Feminino , Teste de Tolerância a Glucose , Hormônio do Crescimento Humano/sangue , Humanos , Hidrocortisona/sangue , Insulina/sangue , Lipídeos/sangue , Pessoa de Meia-Idade , África do Sul , Tomografia Computadorizada por Raios X
19.
Nat Genet ; 28(2): 128-9, 2001 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-11381258

RESUMO

The NOTCH4 gene was recently reported to be associated with schizophrenia based on TDT analysis of 80 British trios. The strongest evidence for association derived from two microsatellites. We genotyped both loci in a large sample of unrelated Scottish schizophrenics and controls, but failed to replicate the reported association, finding instead that each putative schizophrenia-associated allele had a somewhat lower frequency in schizophrenics than in controls.


Assuntos
Proteínas Proto-Oncogênicas/genética , Receptores de Superfície Celular , Esquizofrenia/genética , Alelos , Estudos de Casos e Controles , Genética Populacional , Humanos , Repetições de Microssatélites , Receptor Notch4 , Receptores Notch , Escócia
20.
Anaesthesia ; 55(11): 1106-13, 2000 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11069339

RESUMO

A computerised database of operating theatre activity was used to estimate the costs of regional and general anaesthesia for varicose vein and inguinal hernia surgery. Data retrieved for each procedure included the anaesthetic technique and drugs used, and the duration of anaesthesia, surgery and recovery. The costs of anaesthetic drugs and disposables, salary costs of the anaesthetic personnel and maintenance costs for anaesthetic equipment were considered. Drugs and disposables accounted for approximately 25% of the total cost of an anaesthetic. Anaesthetic times were 5 min longer for regional anaesthesia, but recovery times were 10 min shorter following regional anaesthesia for varicose vein surgery. Staff costs were dependent on the length of time each staff member spent with the patient. Although the number of cases was small, provision of a field block and sedation for inguinal hernia repair was considerably cheaper than other anaesthetic techniques.


Assuntos
Anestesia por Condução/economia , Anestesia Geral/economia , Hérnia Inguinal/cirurgia , Custos Hospitalares/estatística & dados numéricos , Varizes/cirurgia , Anestesia Local/economia , Anestésicos/economia , Custos de Medicamentos , Hérnia Inguinal/economia , Humanos , Bloqueio Nervoso/economia , Admissão e Escalonamento de Pessoal/economia , Escócia , Varizes/economia
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