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1.
Int J Obes (Lond) ; 40(8): 1301-9, 2016 08.
Artículo en Inglés | MEDLINE | ID: mdl-27076275

RESUMEN

BACKGROUND: Genetic variants that predispose individuals to obesity may have differing influences during childhood versus adulthood, and additive effects of such variants are likely to occur. Our ongoing studies to identify genetic determinants of obesity in American Indians have identified 67 single-nucleotide polymorphisms (SNPs) that reproducibly associate with maximum lifetime non-diabetic body mass index (BMI). This study aimed to identify when, during the lifetime, these variants have their greatest impact on BMI increase. SUBJECTS/METHODS: A total of 5906 Native Americans of predominantly Pima Indian heritage with repeated measures of BMI between the ages of 5 and 45 years were included in this study. The association between each SNP with the rates of BMI increase during childhood (5-19 years) and adulthood (20-45 years) were assessed separately. The significant SNPs were used to calculate a cumulative allelic risk score (ARS) for childhood and adulthood, respectively, to assess the additive effect of these variants within each period of life. RESULTS: The majority of these SNPs (36 of 67) were associated with rate of BMI increase during childhood (P-value range: 0.00004-0.05), whereas only nine SNPs were associated with rate of BMI change during adulthood (P-value range: 0.002-0.02). These 36 SNPs associated with childhood BMI gain likely had a cumulative effect as a higher childhood-ARS associated with rate of BMI change (ß=0.032 kg m(-2) per year per risk allele, 95% confidence interval: 0.027-0.036, P<0.0001), such that at age 19 years, individuals with the highest number of risk alleles had a BMI of 10.2 kg m(-2) greater than subjects with the lowest number of risk alleles. CONCLUSIONS: Overall, our data indicates that genetic polymorphisms associated with lifetime BMI may influence the rate of BMI increase during different periods in the life course. The majority of these polymorphisms have a larger impact on BMI during childhood, providing further evidence that prevention of obesity will need to begin early in life.


Asunto(s)
Índice de Masa Corporal , Variación Genética , Indígenas Norteamericanos/genética , Obesidad/genética , Adolescente , Adulto , Alelos , Arizona/epidemiología , Composición Corporal/genética , Niño , Preescolar , Femenino , Predisposición Genética a la Enfermedad/epidemiología , Genotipo , Conocimientos, Actitudes y Práctica en Salud , Humanos , Estudios Longitudinales , Masculino , Persona de Mediana Edad , Obesidad/epidemiología , Obesidad/prevención & control , Polimorfismo de Nucleótido Simple , Adulto Joven
2.
Int J Obes (Lond) ; 38(8): 1068-74, 2014 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-24276017

RESUMEN

BACKGROUND: In rodents, hypothalamic brain-derived neurotrophic factor (BDNF) expression appears to be regulated by melanocortin-4 receptor (MC4R) activity. The impact of MC4R genetic variation on circulating BDNF in humans is unknown. OBJECTIVE: The objective of this study is to compare BDNF concentrations of subjects with loss-of-function (LOF) and gain-of-function (GOF) MC4R variants with those of controls with common sequence MC4R. METHODS: Circulating BDNF was measured in two cohorts with known MC4R sequence: 148 subjects of Pima Indian heritage ((mean±s.d.): age, 15.7±6.5 years; body mass index z-scores (BMI-Z), 1.63±1.03) and 69 subjects of Hispanic heritage (10.8±3.6 years; BMI-Z, 1.57±1.07). MC4R variants were characterized in vitro by cell surface expression, receptor binding and cyclic AMP response after agonist administration. BDNF single-nucleotide polymorphisms (SNPs) rs12291186, rs6265 and rs7124442 were also genotyped. RESULTS: In the Pima cohort, no significant differences in serum BDNF was observed for 43 LOF subjects versus 65 LOF-matched controls (age, sex and BMI matched; P=0.29) or 20 GOF subjects versus 20 GOF-matched controls (P=0.40). Serum BDNF was significantly associated with genotype for BDNF rs12291186 (P=0.006) and rs6265 (P=0.009), but not rs7124442 (P=0.99); BDNF SNPs did not interact with MC4R status to predict serum BDNF. In the Hispanic cohort, plasma BDNF was not significantly different among 21 LOF subjects, 20 GOF subjects and 28 controls (P=0.79); plasma BDNF was not predicted by BDNF genotype or BDNF-x-MC4R genotype interaction. CONCLUSIONS: Circulating BDNF concentrations were not significantly associated with MC4R functional status, suggesting that peripheral BDNF does not directly reflect hypothalamic BDNF secretion and/or that MC4R signaling is not a significant regulator of the bulk of BDNF expression in humans.


Asunto(s)
Factor Neurotrófico Derivado del Encéfalo/metabolismo , Hispánicos o Latinos , Hipotálamo/metabolismo , Indígenas Norteamericanos , Obesidad/metabolismo , Polimorfismo de Nucleótido Simple , Receptor de Melanocortina Tipo 4/metabolismo , Adolescente , Adulto , Arizona , Factor Neurotrófico Derivado del Encéfalo/sangre , Factor Neurotrófico Derivado del Encéfalo/genética , Niño , Preescolar , Estudios de Cohortes , Femenino , Predisposición Genética a la Enfermedad , Genotipo , Hispánicos o Latinos/genética , Hispánicos o Latinos/estadística & datos numéricos , Humanos , Indígenas Norteamericanos/genética , Indígenas Norteamericanos/estadística & datos numéricos , Estudios Longitudinales , Masculino , Mutación , Obesidad/etnología , Obesidad/genética , Regiones Promotoras Genéticas , Receptor de Melanocortina Tipo 4/sangre , Receptor de Melanocortina Tipo 4/genética
3.
Diabetologia ; 56(9): 1971-9, 2013 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-23756832

RESUMEN

AIMS/HYPOTHESIS: MicroRNAs (miRNAs) are short endogenous RNAs that regulate multiple biological processes including adipogenesis and fat metabolism. We sought to identify miRNAs that correlate with BMI and to elucidate their upstream regulation and downstream targets. METHODS: Microarray-based expression profiling of 233 miRNAs was performed on subcutaneous abdominal adipose tissue biopsies from 29 non-diabetic Pima Indian participants. Correlation of the expression levels of eight miRNAs with BMI was assessed by quantitative reverse transcription (QRT) PCR in adipose samples from 80 non-diabetic Pima Indians with a BMI of 21.6-54.0 kg/m(2). The upstream regulation of one of these miRNAs, miR-221, was tested by treating cultured human pre-adipocytes with leptin, TNF-α and insulin. Predicted targets of miR-221 were validated using QRT-PCR, immunoblots and luciferase assays. The downstream effects of miR-221 overexpression were assayed by proteomic analysis. RESULTS: Expression levels of miR-221 were positively correlated with BMI (particularly in women) and fasting insulin concentrations, while the levels of miR-193a-3p and miR-193b-5p were negatively correlated with BMI; other miRNAs did not show significant associations in the 80 samples. miR-221 was downregulated by leptin and TNF-α treatment in cultured human pre-adipocytes. Conversely, miR-221 overexpression upregulated several proteins involved in fat metabolism, mimicking peroxisome proliferator-activated receptor (PPAR) activation. Furthermore, miR-221 directly downregulated the adiponectin receptor 1 (ADIPOR1) and the transcription factor v-ets erythroblastosis virus E26 oncogene homolog 1 (ETS1). Adiponectin signalling is known to promote insulin sensitivity, and ETS1 is crucial for angiogenesis. CONCLUSIONS/INTERPRETATION: Our data suggest that miR-221 may contribute to the development of the insulin resistance that typically accompanies obesity, by affecting PPAR signalling pathways and by directly downregulating ADIPOR1 and ETS1.


Asunto(s)
Tejido Adiposo/metabolismo , Leptina/genética , MicroARNs/genética , Obesidad/genética , Factor de Necrosis Tumoral alfa/genética , Western Blotting , Índice de Masa Corporal , Células Cultivadas , Humanos , Leptina/metabolismo , Metabolismo de los Lípidos/genética , Metabolismo de los Lípidos/fisiología , MicroARNs/metabolismo , Obesidad/metabolismo , Análisis de Secuencia por Matrices de Oligonucleótidos , Proteómica , Factor de Necrosis Tumoral alfa/metabolismo
4.
Nat Genet ; 26(2): 163-75, 2000 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-11017071

RESUMEN

Type 2 or non-insulin-dependent diabetes mellitus (NIDDM) is the most common form of diabetes worldwide, affecting approximately 4% of the world's adult population. It is multifactorial in origin with both genetic and environmental factors contributing to its development. A genome-wide screen for type 2 diabetes genes carried out in Mexican Americans localized a susceptibility gene, designated NIDDM1, to chromosome 2. Here we describe the positional cloning of a gene located in the NIDDM1 region that shows association with type 2 diabetes in Mexican Americans and a Northern European population from the Botnia region of Finland. This putative diabetes-susceptibility gene encodes a ubiquitously expressed member of the calpain-like cysteine protease family, calpain-10 (CAPN10). This finding suggests a novel pathway that may contribute to the development of type 2 diabetes.


Asunto(s)
Calpaína/genética , Cromosomas Humanos Par 2 , Diabetes Mellitus Tipo 2/genética , Predisposición Genética a la Enfermedad , Variación Genética , Polimorfismo Genético , Adulto , Secuencia de Aminoácidos , Calpaína/química , Mapeo Cromosómico , Diabetes Mellitus Tipo 2/enzimología , Diabetes Mellitus Tipo 2/epidemiología , Finlandia , Frecuencia de los Genes , Marcadores Genéticos , Genoma Humano , Haplotipos , Humanos , Americanos Mexicanos/genética , Datos de Secuencia Molecular , Medición de Riesgo , Estados Unidos , Población Blanca/genética
5.
Diabetologia ; 54(7): 1684-92, 2011 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-21484216

RESUMEN

AIMS/HYPOTHESIS: We sought to identify the physiological implications of genetic variation at the HLA-DRB1 region in full-heritage Pima Indians in Arizona. METHODS: Single-nucleotide polymorphisms from the HLA region on chromosome 6p were tested for association with skeletal muscle mRNA expression of HLA-DRB1 and HLA-DRA, and with type 2 diabetes mellitus and prediabetic traits. RESULTS: The A allele at rs9268852, which tags HLA-DRB1 02(1602), was associated both with higher HLA-DRB1 mRNA expression (n = 133, p = 4.27 × 10(-14)) and decreased risk of type 2 diabetes (n = 3,265, OR 0.723, p = 0.002). Among persons with normal glucose tolerance (n = 266) this allele was associated with a higher mean acute insulin response during an intravenous glucose tolerance test (p = 0.005), higher mean 30 min insulin concentration during an oral glucose tolerance test (p = 0.017) and higher body fat percentage (p = 0.010). The polymorphism was not associated with HLA-DRA mRNA expression or insulin sensitivity. CONCLUSIONS/INTERPRETATION: HLA-DRB1*02 is protective for type 2 diabetes, probably by enhancing self tolerance, thereby protecting against the autoimmune-mediated reduction of insulin secretion.


Asunto(s)
Diabetes Mellitus Tipo 2/genética , Antígenos HLA-DR/genética , Insulina/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , Femenino , Predisposición Genética a la Enfermedad , Antígenos HLA-DR/metabolismo , Cadenas alfa de HLA-DR , Cadenas HLA-DRB1 , Humanos , Secreción de Insulina , Masculino , Músculo Esquelético/metabolismo , Polimorfismo de Nucleótido Simple/genética
6.
Diabetologia ; 53(7): 1349-53, 2010 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-20390405

RESUMEN

AIMS/HYPOTHESIS: A prior genome-wide association study in Pima Indians identified a variant within the ACAD10 gene that is associated with early-onset type 2 diabetes. Acylcoenzyme A dehydrogenase 10 (ACAD10) catalyses mitochondrial fatty acid beta-oxidation, which plays a pivotal role in developing insulin resistance and type 2 diabetes. Therefore, ACAD10 was analysed as a positional and biological candidate for type 2 diabetes. METHODS: Twenty-three SNPs were genotyped in 1,500 Pima Indians to determine the linkage disequilibrium pattern across ACAD10. Association with type 2 diabetes was determined by genotyping four tag single nucleotide polymorphisms (SNPs) in a population-based sample of 3,501 full-heritage Pima Indians; two associated SNPs were further genotyped in a second population-based sample of 3,723 American Indians. Associations with quantitative traits were assessed in 415 non-diabetic full heritage Pima individuals who had been metabolically phenotyped. RESULTS: SNPs rs601663 and rs659964 were associated with type 2 diabetes in the full-heritage Pima Indian sample (p=0.04 and 0.0006, respectively), and rs659964 was further associated with type 2 diabetes in the second American Indian sample (p=0.04). Combination of these two samples provided the strongest evidence for association (p=0.009 and 0.00007, for rs601663 and rs659964, respectively). Quantitative trait analyses identified nominal associations with both lower lipid oxidation rate and larger subcutaneous abdominal adipocyte size, which is consistent with the known physiology of ACAD10, and also identified associations with increased insulin resistance. CONCLUSIONS/INTERPRETATION: We propose that ACAD10 variation may increase type 2 diabetes susceptibility by impairing insulin sensitivity via abnormal lipid oxidation.


Asunto(s)
Acil-CoA Deshidrogenasa/genética , Diabetes Mellitus Tipo 2/genética , Indígenas Norteamericanos/genética , Resistencia a la Insulina/genética , Metabolismo de los Lípidos/genética , Adolescente , Adulto , Femenino , Predisposición Genética a la Enfermedad/genética , Genotipo , Humanos , Desequilibrio de Ligamiento/genética , Masculino , Persona de Mediana Edad , Oxidación-Reducción , Fenotipo , Polimorfismo de Nucleótido Simple/genética , Adulto Joven
7.
Int J Obes (Lond) ; 34(10): 1526-30, 2010 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-20029378

RESUMEN

OBJECTIVE: This study identified the journals with the highest yield of clinical obesity research articles and surveyed the scatter of such studies across journals. The study exemplifies an approach to establish a journal collection that is likely to contain most new knowledge about a field. DESIGN AND METHODS: All original studies that were cited in 40 systematic reviews about obesity topics ('included studies') were compiled and journal titles in which they were published were extracted. The journals were ranked by the number of included studies. The highest-yielding journals for clinical obesity and the scatter across journal titles were determined. A subset of these journals was created in MEDLINE (PubMed) to test search recall and precision for high-quality studies of obesity treatment (that is, articles that pass predetermined methodology criteria, including random allocation of participants to comparison groups, assessment of clinical outcomes, and at least 80% follow-up). RESULTS: Articles in 252 journals were cited in the systematic reviews. The three highest-yielding journals specialized in obesity, but they published only 19.2% of the research, leaving 80.8% scattered across 249 non-obesity journals. The MEDLINE journal subset comprised 241 journals (11 journals were not indexed in MEDLINE) and included 82% of the clinical obesity research articles retrieved by a search for high-quality treatment studies ('recall' of 82%). Of the articles retrieved, 11% were about clinical obesity care ('precision' of 11%), compared with precision of 6% for obesity treatment studies in the full MEDLINE database. CONCLUSION: Obesity journals captured only a small proportion of the literature on clinical obesity care. Those wishing to keep up in this field will need to develop more inclusive strategies than reading these specialty journals. A journal subset based on these findings may be useful when searching large electronic databases to increase search precision.


Asunto(s)
Bibliometría , Medicina Basada en la Evidencia/estadística & datos numéricos , Obesidad , Publicaciones Periódicas como Asunto/estadística & datos numéricos , Difusión de Innovaciones , Humanos , Investigación/estadística & datos numéricos
8.
Transplant Proc ; 50(5): 1444-1450, 2018 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-29880368

RESUMEN

BACKGROUND: Patients after liver transplantation (LT) with hepatitis C virus (HCV) infection often suffer from renal or hepatic impairment. Treating patients after LT with direct-acting antivirals (DAA) might result in decreasing renal function due to interaction of DAA and immunosuppressive therapy. In this single-center study we analyzed clinical parameters of 18 HCV-infected patients treated with DAA therapy after LT. METHODS: The primary end points were change of renal function (glomerular filtration rate) and sustained virologic response 12 weeks after therapy (SVR12). For secondary end points, we investigated the influence of DAA therapy on transaminases, bilirubin, international normalized ratio, noninvasive fibrosis measurement, and Model for End-Stage Liver Disease (MELD) score. RESULTS: Five out of 18 patients treated with DAA suffered from renal impairment stage 2, and 7 patients of renal impairment stage 3. Renal function at SVR12 was not influenced by preexisting renal impairment (P > .5), type of immunosuppressant (P > .5), or type of DAA regimen (P > .5). All patients reached SVR12. The levels of transaminases and bilirubin declined rapidly, as expected. Ten out of 18 patients already suffered from cirrhosis or liver fibrosis >F3 according to noninvasive measurement before initiation of treatment. Single-point acoustic radiation force impulse imaging improved in 9 patients (P = .012). In 7 patients, MELD score improved owing to the decrease of bilirubin levels. In 6 patients it worsened. CONCLUSIONS: DAA therapy in LT patients was effective and safe in this single-center real-life cohort. Renal function was not influenced by the administered drug combinations, even in patients with preexisting renal impairment.


Asunto(s)
Antivirales/uso terapéutico , Hepatitis C Crónica/tratamiento farmacológico , Riñón/efectos de los fármacos , Trasplante de Hígado/métodos , Adulto , Anciano , Estudios de Cohortes , Femenino , Hepacivirus , Hepatitis C Crónica/complicaciones , Humanos , Masculino , Persona de Mediana Edad , Respuesta Virológica Sostenida , Resultado del Tratamiento
9.
J Clin Invest ; 97(9): 2051-6, 1996 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-8621794

RESUMEN

Interleukin 1 and nitric oxide (NO) from infiltrating macrophages and activated mesangial cells may act in concert to sustain and promote glomerular damage. To evaluate if such synergy occurs, we evaluated the effect if IL-1 beta and NO on the formation of prostaglandin (PG)E2 and cyclooxygenase (COX) expression. The NO donors, sodium nitroprusside and S-nitroso-N-acetylpenicillamine, alone did not increase basal PGE2 formation. However, these compounds amplified IL-1 beta-induced PGE2 production. Similarly, sodium nitroprusside and S-nitroso-N-acetylpenicillamine by themselves did not induce mRNA and protein for COX-2, the inducible isoform of COX; however, they both potentiated IL-1 beta-induced mRNA and protein expression of COX-2. The stimulatory effect of NO is likely to be mediated by cGMP since (a) an inhibitor of the soluble guanylate cyclase, methylene blue, reversed the stimulatory effect of NO donors on COX-2 mRNA expression; (b) the membrane-permeable cGMP analogue, 8-Br-cGMP, mimicked the stimulatory effect of NO donors on COX-2-mRNA expression; and (c) atrial natriuretic peptide, which increases cellular cGMP by activating the membrane-bound guanylate cyclase, also amplified IL-1 beta-induced COX-2 mRNA expression. These data indicate a novel interaction between NO and COX pathways.


Asunto(s)
Dinoprostona/biosíntesis , Mesangio Glomerular/metabolismo , Interleucina-1/farmacología , Isoenzimas/biosíntesis , Óxido Nítrico/farmacología , Prostaglandina-Endoperóxido Sintasas/biosíntesis , Animales , Células Cultivadas , Ciclooxigenasa 2 , Sinergismo Farmacológico , Regulación Enzimológica de la Expresión Génica/efectos de los fármacos , Humanos , Masculino , Proteínas de la Membrana , Ratas , Ratas Sprague-Dawley , Transducción de Señal/efectos de los fármacos
10.
J Clin Invest ; 95(3): 1281-7, 1995 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-7883976

RESUMEN

The intestinal fatty acid binding protein locus (FABP2) was investigated as a possible genetic factor in determining insulin action in the Pima Indian population. A polymorphism at codon 54 of FABP2 was identified that results in an alanine-encoding allele (frequency 0.71) and a threonine-encoding allele (frequency 0.29). Pimas who were homozygous or heterozygous for the threonine-encoding allele were found to have a higher mean fasting plasma insulin concentration, a lower mean insulin-stimulated glucose uptake rate, a higher mean insulin response to oral glucose and a mixed meal, and a higher mean fat oxidation rate compared with Pimas who were homozygous for the alanine-encoding allele. Since the FABP2 threonine-encoding allele was found to be associated with insulin resistance and increased fat oxidation in vivo, we further analyzed the FABP2 gene products for potential functional differences. Titration microcalorimetry studies with purified recombinant protein showed that the threonine-containing protein had a twofold greater affinity for long-chain fatty acids than the alanine-containing protein. We conclude that the threonine-containing protein may increase absorption and/or processing of dietary fatty acids by the intestine and thereby increase fat oxidation, which has been shown to reduce insulin action.


Asunto(s)
Proteínas Portadoras/genética , Ácidos Grasos/metabolismo , Indígenas Norteamericanos/genética , Resistencia a la Insulina/genética , Proteínas de Neoplasias , Mutación Puntual , Proteínas Supresoras de Tumor , Adulto , Alanina/genética , Alelos , Arizona , Secuencia de Bases , Calorimetría , Cromosomas Humanos Par 4/genética , Diabetes Mellitus Tipo 2/etiología , Proteína de Unión a los Ácidos Grasos 7 , Proteínas de Unión a Ácidos Grasos , Femenino , Frecuencia de los Genes , Glucosa/metabolismo , Técnica de Clampeo de la Glucosa , Humanos , Masculino , Modelos Moleculares , Datos de Secuencia Molecular , Oxidación-Reducción , Reacción en Cadena de la Polimerasa , Estudios Prospectivos , Factores de Riesgo , Treonina/genética
11.
J Clin Invest ; 106(7): R69-73, 2000 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-11018080

RESUMEN

Previous linkage studies in Mexican-Americans localized a major susceptibility locus for type 2 diabetes, NIDDM1, to chromosome 2q. This evidence for linkage to type 2 diabetes was recently found to be associated with a common G-->A polymorphism (UCSNP-43) within the CAPN10 gene. The at-risk genotype was homozygous for the UCSNP-43 G allele. In the present study among Pima Indians, the UCSNP-43 G/G genotype was not associated with an increased prevalence of type 2 diabetes. However, Pima Indians with normal glucose tolerance, who have a G/G genotype at UCSNP-43, were found to have decreased rates of postabsorptive and insulin-stimulated glucose turnover that appear to result from decreased rates of glucose oxidation. In addition, G/G homozygotes were found to have reduced CAPN10 mRNA expression in their skeletal muscle. A decreased rate of insulin-mediated glucose turnover, or insulin resistance, is one mechanism by which the polymorphism in CAPN10 may increase susceptibility to type 2 diabetes mellitus in older persons.


Asunto(s)
Calpaína/genética , Diabetes Mellitus Tipo 2/genética , Indígenas Norteamericanos , Resistencia a la Insulina/genética , Polimorfismo Genético , Adolescente , Adulto , Factores de Edad , Arizona , Biopsia , Glucemia/metabolismo , Niño , Femenino , Genotipo , Prueba de Tolerancia a la Glucosa , Humanos , Masculino , Persona de Mediana Edad , Proteínas Musculares/biosíntesis , Músculos/enzimología , ARN Mensajero/análisis , Factores Sexuales
12.
J Clin Invest ; 101(8): 1757-64, 1998 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-9541507

RESUMEN

Type 2 diabetes mellitus is a common chronic disease that is thought to have a substantial genetic basis. Identification of the genes responsible has been hampered by the complex nature of the syndrome. Abnormalities in insulin secretion and insulin action predict the development of type 2 diabetes and are, themselves, highly heritable traits. Since fewer genes may contribute to these precursors of type 2 diabetes than to the overall syndrome, such genes may be easier to identify. We, therefore, undertook an autosomal genomic scan to identify loci linked to prediabetic traits in Pima Indians, a population with a high prevalence of type 2 diabetes. 363 nondiabetic Pima Indians were genotyped at 516 polymorphic microsatellite markers on all 22 autosomes. Linkage analyses were performed using three methods (single-marker, nonparametric multipoint [MAPMAKER/SIBS], and variance components multipoint). These analyses provided evidence for linkage at several chromosomal regions, including 3q21-24 linked to fasting plasma insulin concentration and in vivo insulin action, 4p15-q12 linked to fasting plasma insulin concentration, 9q21 linked to 2-h insulin concentration during oral glucose tolerance testing, and 22q12-13 linked to fasting plasma glucose concentration. These results suggest loci that may harbor genes contributing to type 2 diabetes in Pima Indians. None of the linkages exceeded a LOD score of 3.6 (a 5% probability of occurring in a genome-wide scan). These findings must, therefore, be considered tentative until extended in this population or replicated in others.


Asunto(s)
Diabetes Mellitus Tipo 2/genética , Ligamiento Genético , Indígenas Norteamericanos/genética , Estado Prediabético/genética , Adulto , Cromosomas Humanos Par 22/genética , Cromosomas Humanos Par 3/genética , Cromosomas Humanos Par 4/genética , Cromosomas Humanos Par 9/genética , Diabetes Mellitus Tipo 2/sangre , Femenino , Genotipo , Humanos , Insulina/sangre , Escala de Lod , Masculino , Repeticiones de Microsatélite , Polimorfismo Genético , Estado Prediabético/sangre
13.
Diabetes ; 50(4): 901-4, 2001 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-11289060

RESUMEN

Brain dopaminergic pathways play a major role in the control of movement. Absence of the murine dopamine D2 receptor gene (drd2) produces bradykinesia and hypothermia. A Ser311Cys mutation of the human DRD2 produces a marked functional impairment of the receptor and is associated with higher BMI in some populations. We hypothesized that the Ser311Cys mutation of DRD2 may inhibit energy expenditure. Here we report that total energy expenditure (doubly labeled water) measured in 89 nondiabetic Pima Indians was 244 kcal/ day lower in homozygotes for the Cys311-encoding allele when compared with those heterozygous and homozygous for the Ser311-encoding allele (P = 0.056). The 24-h resting energy expenditure (respiratory chamber) measured in 320 nondiabetic Pimas was also 87 kcal/day lower in homozygotes for the Cys311-encoding allele when compared with those heterozygous and homozygous for the Ser311-encoding allele (P = 0.026). These findings are the first evidence that a genetic mutation is associated with reduced energy expenditure in humans. Because the impact of this mutation on human obesity is small, we suggest that either the energy deficit induced is not large enough to significantly influence body weight in this population and/or that the Cys311-encoding allele is also associated with reduced energy intake.


Asunto(s)
Metabolismo Energético/genética , Mutación/genética , Mutación/fisiología , Receptores de Dopamina D2/genética , Adulto , Alelos , Secuencia de Aminoácidos/genética , Femenino , Heterocigoto , Homocigoto , Humanos , Indígenas Norteamericanos/genética , Masculino , Valores de Referencia
14.
Diabetes Care ; 23(3): 302-4, 2000 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-10868855

RESUMEN

OBJECTIVE: Maturity-onset diabetes of the young (MODY) is a genetically heterogeneous subtype of type 2 diabetes characterized by an early age at onset and autosomal dominant inheritance. MODY can result from heterozygous mutations in at least five genes. The purpose of this study was to determine whether alterations in known MODY genes and two MODY candidate genes contribute to the development of early-onset type 2 diabetes in Pima Indians. RESEARCH DESIGN AND METHODS: The coding regions of the known MODY genes hepatocyte nuclear factor (HNF)-1alpha, HNF-4alpha, HNF-1beta, and insulin promoter factor 1 and the coding regions of two MODY candidate genes, HNF-3beta and the dimerization cofactor of HNF-1, were sequenced in genomic DNA from Pima Indians. The primary "affected" study population consisted of 46 Pima Indians whose age at onset of type 2 diabetes was < or =20 years. DNA sequence variants identified in the affected group were then analyzed in a group of 80 "unaffected" Pima Indians who were at least 40 years old and had normal glucose tolerance. RESULTS: A total of 11 polymorphisms were detected in these genes. However, none of the polymorphisms differed in frequency among Pima Indians with an early age at onset of diabetes compared with older Pima Indians with normal glucose tolerance. CONCLUSIONS: Mutations in these known MODY or MODY candidate genes are not a common cause of early-onset diabetes in Pima Indians.


Asunto(s)
Proteínas de Unión al ADN/genética , Diabetes Mellitus Tipo 2/genética , Etnicidad/genética , Proteínas de Homeodominio , Indígenas Norteamericanos/genética , Proteínas Nucleares/genética , Fosfoproteínas/genética , Polimorfismo Genético , Transactivadores/genética , Factores de Transcripción/genética , Adolescente , Adulto , Edad de Inicio , Arizona , Factores de Transcripción Básicos con Cremalleras de Leucinas y Motivos Hélice-Asa-Hélice , Codón , Dimerización , Exones , Factor Nuclear 1 del Hepatocito , Factor Nuclear 1-alfa del Hepatocito , Factor Nuclear 1-beta del Hepatocito , Factor Nuclear 3-beta del Hepatocito , Factor Nuclear 4 del Hepatocito , Humanos , Mutación , Factores de Transcripción/química
15.
J Clin Endocrinol Metab ; 83(8): 2993-6, 1998 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-9709981

RESUMEN

Electrophoretic variants of the vitamin D-binding protein (DBP) have been associated with type 2 diabetes as well as with metabolic characteristics that predispose to type 2 diabetes in several populations. The Gc gene that encodes DBP maps to chromosome 4q12, a region that has recently been found to be potentially linked to plasma glucose and insulin concentrations in Pima Indians. Therefore, the gene that encodes DBP was analyzed as a candidate gene for our linkage findings in the Pima Indians. Sequence analysis of the coding exons identified two previously described missense polymorphisms at codons 416 and 420, which are the genetic basis for the three common electrophoretic variants of DBP (Gc1f, Gc1s, and Gc2). These variants in DBP were associated with differences in oral glucose tolerance in nondiabetic Pima Indians.


Asunto(s)
Variación Genética , Prueba de Tolerancia a la Glucosa , Indígenas Norteamericanos/genética , Estado Prediabético/genética , Proteína de Unión a Vitamina D/genética , Adulto , Alelos , Glucemia/metabolismo , Cromosomas Humanos Par 4 , Diabetes Mellitus Tipo 2/genética , Femenino , Frecuencia de los Genes , Humanos , Insulina/sangre , Masculino , Polimorfismo Genético
16.
Brain Res ; 588(2): 255-60, 1992 Aug 21.
Artículo en Inglés | MEDLINE | ID: mdl-1382810

RESUMEN

Male ICR mice were fed powdered laboratory chow containing phenobarbital for 7 days to induce tolerance. Mice were sacrificed and brains assayed for changes in GABA-mediated chloride flux into brain membrane vesicles (microsacs). Concentration-dependent stimulation of chloride flux by GABA alone was not affected by the development of tolerance to phenobarbital. Phenobarbital potentiation of GABA-mediated chloride flux was significantly attenuated in the membranes prepared from phenobarbital-tolerant mice compared with those from pair-fed control mice. Similarly, stimulation of GABA-mediated flux by the benzodiazepine, flunitrazepam was also depressed in membranes from tolerant mice. However, the ability of ethanol and the benzodiazepine inverse agonist FG-7142 to modulate GABA-gated chloride flux was not affected by the development of phenobarbital tolerance. No significant changes in saturation [3H]diazepam binding parameters were observed. These findings suggest that there is a degree of cross-tolerance between phenobarbital and benzodiazepine agonist at the level of the GABA-operated chloride channel. Furthermore, although some reports have demonstrated behavioral cross-tolerance between ethanol and barbiturates, the present data suggest different mechanisms of tolerance development for these intoxicants at the level of the GABAA receptor chloride channel complex.


Asunto(s)
Barbitúricos/farmacología , Cloruros/metabolismo , Canales Iónicos/efectos de los fármacos , Ácido gamma-Aminobutírico/fisiología , Animales , Ansiolíticos/farmacología , Encéfalo/efectos de los fármacos , Encéfalo/metabolismo , Diazepam/metabolismo , Etanol/farmacología , Masculino , Membranas/efectos de los fármacos , Membranas/metabolismo , Ratones , Ratones Endogámicos ICR , Fenobarbital/farmacología
17.
Life Sci ; 51(12): 931-43, 1992.
Artículo en Inglés | MEDLINE | ID: mdl-1381457

RESUMEN

Withdrawal seizure prone (WSP) and withdrawal seizure resistant (WSR) mice were treated with 5 mg/kg lorazepam for 7 days via implanted osmotic mini pumps. Following chronic drug treatment, brains were assayed for GABA-mediated chloride flux (GABA-Cl-). Under control (drug naive) conditions, brain membranes prepared from WSP and WSR lines did not differ in flunitrazepam or ethanol stimulation of GABA-mediated 36Cl- uptake, but the WSP lines were more sensitive to inhibition of 36Cl- flux by the inverse agonist, FG-7142. Membranes from lorazepam tolerant WSP and WSR mice were resistant to flunitrazepam- and ethanol-stimulation of GABA-Cl-. Withdrawal from chronic treatment, by an acute injection with the benzodiazepine antagonist RO15-1788, returned flunitrazepam stimulation of GABA-Cl- to near control levels in WSR membranes but not in WSP membranes and restored ethanol modulation of the channel to control levels in both lines. Inhibition of chloride flux by the benzodiazepine partial inverse agonist, FG-7142 was greater in membranes from WSP mice compared with WSR mice. Tolerance to lorazepam increased sensitivity of the WSR membranes to FG-7142 without altering the response in the WSP line. Again, withdrawal restored the Cl- flux response to FG-7142 back to near control levels. Lorazepam tolerance lowered [3H]-flunitrazepam binding affinity slightly only in the WSR strain with no change in binding number. Withdrawal from chronic lorazepam treatment produced no significant change in binding affinity or number. The initial genotypic differences in benzodiazepine inverse agonist sensitivity, may be related to the selection for withdrawal seizure severity. Chronic administration of lorazepam reduces the coupling between the benzodiazepine agonist site and the chloride channel and concomitantly increases coupling between the channel and the inverse agonist site, while withdrawal resets the receptor coupling back to control response levels. However, for the WSP line, this drug environment dependent shift in channel coupling bias appears to be deficient compared with the WSR line.


Asunto(s)
Encéfalo/efectos de los fármacos , Etanol/efectos adversos , Lorazepam/farmacología , Proteínas de la Membrana/metabolismo , Receptores de GABA-A/metabolismo , Convulsiones/metabolismo , Síndrome de Abstinencia a Sustancias/metabolismo , Animales , Benzodiazepinas/farmacología , Encéfalo/metabolismo , Canales de Cloruro , Cloruros , Tolerancia a Medicamentos , Etanol/administración & dosificación , Bombas de Infusión Implantables , Canales Iónicos , Masculino , Ratones , Ratones Mutantes , Convulsiones/inducido químicamente
18.
Lipids ; 31 Suppl: S267-70, 1996 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-8729131

RESUMEN

We studied the role of lipids in the pathogenesis of noninsulin-dependent diabetes mellitus (NIDDM) in Pima Indians. High plasma levels of nonesterified fatty acid (NEFA) predicted development of NIDDM, but this effect cannot entirely be explained by the glucose-fatty acid cycle. Dyslipidemia, although often associated with diabetes, did not seem to predict NIDDM and might rather be associated with, or the consequence of insulin resistance. In some individuals, a single amino acid substitution in the intestinal fatty acid binding protein could result in increased rates of intestinal absorption of dietary NEFA and thereby contribute to increased lipid-oxidation rates and insulin resistance.


Asunto(s)
Diabetes Mellitus Tipo 2/fisiopatología , Indígenas Norteamericanos , Lípidos/fisiología , Proteínas de Neoplasias , Proteínas Supresoras de Tumor , Arizona , Proteínas Portadoras/análisis , Diabetes Mellitus Tipo 2/diagnóstico , Proteína de Unión a los Ácidos Grasos 7 , Proteínas de Unión a Ácidos Grasos , Ácidos Grasos/análisis , Ácidos Grasos no Esterificados/metabolismo , Femenino , Humanos , Resistencia a la Insulina , Mucosa Intestinal/metabolismo , Estudios Longitudinales , Masculino , Proteína P2 de Mielina/análisis , Polimorfismo Genético , Valor Predictivo de las Pruebas , Factores de Riesgo
19.
J N Y State Nurses Assoc ; 28(3): 4-7, 1997 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-9369654

RESUMEN

Twenty-two registered nurses employed in four long-term care facilities generated data for a study about nursing diagnoses in long-term care (N = 360). Generic outcome objectives were developed as an integral part of the project. The research team also specified exceptions to the outcomes: instances where meeting outcome objectives might not be possible. The outcome objectives and exceptions for the sample's 20 most frequently occurring nursing diagnoses are presented as working statements. The authors expect that these outcome objectives and exceptions will be revised by nurses who use them in practice, basic and continuing education, and research.


Asunto(s)
Atención de Enfermería/normas , Diagnóstico de Enfermería , Evaluación de Procesos y Resultados en Atención de Salud , Instituciones de Cuidados Especializados de Enfermería , Humanos , Personal de Enfermería en Hospital
20.
J N Y State Nurses Assoc ; 21(3): 19-23, 1990 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-2120399

RESUMEN

This exploratory project in developing outcome criteria for long term care was conducted with the view that the individual professional nursing practitioner has a unique, valuable contribution to make to the overall nursing quality assurance effort. Twenty-seven nurses volunteered to design and conduct individual systematic nursing diagnosis/intervention/outcome measurement projects. They were employees of five long term care facilities in New York state. Their contribution to this project was an embodiment of their professional judgement and practice with 107 selected clients under their care. They were prepared for participation through instruction repeated in all five facilities. The North American Nursing Diagnosis Association's Taxonomy of Nursing Diagnoses was used in the instruction, by the practitioners in their practice and data collection, and in the data analysis. Data analysis also included use of Campbell's nursing intervention category scheme. This work demonstrated that professional nurses are able to specify appropriate outcome criteria and to measure these outcomes of their planned nursing interventions. Eighty-seven percent of the expected outcomes were achieved as anticipated or in the anticipated direction. Results provided many leads for future study of nursing diagnosis/intervention/outcome measurement among residents of long term care institutions.


Asunto(s)
Cuidados a Largo Plazo/normas , Atención de Enfermería/normas , Evaluación de Procesos y Resultados en Atención de Salud , Humanos , New York , Diagnóstico de Enfermería
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