Obesidade genética não sindrômica: histórico, fisiopatologia e principais genes / Non-syndromic genetic obesity: history, pathophysiology and key genes

A obesidade é definida pelo excesso de gordura corporal acumulada no tecido adiposo quando o indivíduo atinge valores de IMC igual ou superior a 30 Kg/m2. Constitui um dos principais fatores de risco para várias doenças não transmissíveis (DNTs) como por exemplo, diabetes mellitus tipo 2 (DM2), doenças cardiovasculares, hipertensão arterial, acidente vascular cerebral e até mesmo o câncer. Embora a obesidade esteja diretamente relacionada com o consumo calórico excessivo em relação ao gasto energético diário, sua etiologia pode estar associada aos baixos níveis de atividade física, às alterações neuroendócrinas e aos fatores genéticos. Considerando o componente genético, esta pode ser classificada como sindrômicas e estar associada às alterações cromossômicas estruturais ou numéricas, ou como não sindrômica, quando relacionada, principalmente, com os polimorfismos de nucleotídeos simples (SNPs) em alelos que atuam como herança monogênica, ou ainda com a interação vários genes (poligênica multifatorial). Apesar de existirem muitas etiologias diferentes, normalmente a obesidade é tratada a partir da mesma abordagem, desconsiderando a fisiologia que a desencadeou. Dessa forma, o objetivo do presente trabalho foi abordar a obesidade genética não sindrômica por meio a) da descrição breve de perspectiva histórica sobre seu entendimento; b) da exposição dos principais mecanismos moleculares envolvidos com o controle de peso; c) da compilação dos principais genes e SNPs relacionados; d) da definição dos principais genes; e e) da abordagem das principais perspectivas de intervenção.

Obesity is defined as excess body fat accumulated in the adipose tissue when the individual reaches BMI values equal to or greater than 30 kg/m2. It is one of the main risk factors for several non-communicable diseases (NCDs), such as Type 2 Diabetes mellitus (T2D), cardiovascular diseases, high blood pressure, stroke and even cancer. Although obesity is directly related to excessive calorie intake in relation to daily energy expenditure, its etiology may be associated with low levels of physical activity, neuroendocrine changes, and genetic factors. Considering the genetic component, it can be classified as syndromic and be associated with chromosomal or numerical changes, or as non-syndromic and being related mainly to single nucleotide polymorphisms (SNPs) in alleles that act as monogenic inheritance, or with an interaction of several genes (multifactorial polygenic). Although there are many different etiologies, obesity is usually treated using the same approach, disregarding the physiology that triggered it. Thus, the aim of this study was to address non-syndromic genetic obesity through a) a brief description of a historical perspective on its understanding; b) the exposure of the main molecular mechanisms involved in weight control, c) the compilation of the key genes and related SNPs, d) the definition of the key genes and e) the approach of the main intervention representations.

Genetic parameters for weight, morphometry and oviposition of Africanized honeybee queens using simulated data / [Parâmetros genéticos para peso, morfometria e oviposição de abelhas rainhas africanizadas sob simulação]

This study aimed to estimate genetic parameters for simulated data of body weight (BW), abdominal width (AW), abdominal length (AL), and oviposition. Simulation was performed based on real data collected at apiaries in the region of Campo das Vertentes, Minas Gerais, Brazil. Genetic evaluations were performed using single- and two-trait models and (co)variance components were estimated by the restricted maximum likelihood method. The heritability for BW, AW, AL and oviposition were 0.54, 0.47, 0.31 and 0.66, respectively. Positive genetic correlations of high magnitude were obtained between BW and AW (0.80), BW and oviposition (0.69), AW and oviposition (0.82), and AL and oviposition (0.96). The genetic correlations between BW and AL (0.11) and between AW and AL (0.26) were considered moderate and low. In contrast, the phenotypic correlations were positive and high between BW and AW (0.97), BW and AL (0.96), and AW and AL (0.98). Phenotypic correlations of low magnitude and close to zero were obtained for oviposition with AL (0.02), AW (-0.02), and BW (-0.03). New studies involving these characteristics should be conducted on populations with biological data in order to evaluate the impact of selection on traits of economic interest.(AU)

Objetivou-se estimar parâmetros genéticos para dados simulados de peso corporal (PC), largura abdominal (LA), comprimento abdominal (CA) e oviposição (OV). A simulação foi conduzida com base em dados reais, coletados em apiários da região do Campo das Vertentes, Minas Gerais. As estimativas das análises genéticas foram realizadas por modelos uni e bicaracterísticos, sendo os componentes de (co) variância estimados pelo método da máxima verossimilhança restrita. As herdabilidades para PC, LA, CA e OV foram de 0,54, 0,47, 0,31 e 0,66 respectivamente. As correlações genéticas foram positivas e de alta magnitude para PC e LA (0,80), PC e OV (0,69), LA e OV (0,82) e CA e OV (0,96). Para PC e CA (0,11) e LA e CA (0,26), as correlações genéticas foram moderadas e de baixa magnitude. As correlações fenotípicas foram positivas e de alta magnitude para PC e LA (0,97), PC e CA (0,96) e LA e CA (0,98). Para OV e CA (0,02), OV e LA (-0,02) e OV e PC (-0,03), foram encontradas correlações fenotípicas de magnitude baixa e próximas de zero. Novos estudos devem ser realizados em populações com dados biológicos, a fim de se observar o impacto da seleção em características de interesse econômico.(AU)

Metabolic phenotypes of obese, overweight, and normal weight individuals and risk of chronic kidney disease: a systematic review and meta-analysis

ABSTRACT Objective Chronic kidney disease (CKD) risk is inconsistent in the normal-weight, overweight, and obese individuals due to the heterogeneity of metabolic status. This meta-analysis aimed to examine the combined effects of body mass index (BMI) and metabolic status on CKD risk. Materials and methods The MEDLINE, EMBASE, and Web of Knowledge databases were systematically searched up to March 2019 to identify all eligible studies investigating the CKD risk (defined as GFR < 60 mL/min per 1.73 m2 and/or microalbuminuria or proteinuria) associated with the body size phenotypes which are known as metabolically unhealthy normal-weight (MUNW), metabolically healthy overweight (MHOW), metabolically unhealthy overweight, metabolically healthy obese (MHO) and metabolically unhealthy obese (MUHO). The classification of subjects in included studies as metabolically unhealthy was based on the presence of three components of metabolic syndrome. BMI categorization was based on the criteria of included studies. The risk estimates and 95% confidence intervals (CIs) were extracted and pooled using random effects analysis. Results A total of 9 prospective cohort studies with 128773 participants and 4797 incident cases were included in the meta-analysis. Compared with healthy normal-weight individuals as reference, MUNW and MHO subjects showed an increased risk for CKD events with a pooled RR of 1.58 (95% CI = 1.28-1.96) in MUNW and 1.55 (95% CI = 1.34-1.79) in MHO persons. Also, MHOW was at increased risk for CKD (RR = 1.34, 95% CI = 1.20-1.51). MUHO individuals were at the highest risk for the development of CKD (RR = 2.13, 95% CI = 1.66-2.72). Conclusions Individuals with metabolic abnormality, although at normal-weight, have an increased risk for CKD. Healthy overweight and obese individuals had higher risk; refuting the notion that metabolically healthy overweight and obese phenotypes are benign conditions.

Interactive effects of genotype x environment on the live weight of GIFT Nile tilapias

ABSTRACT In this paper, the existence of a genotype x environment interaction for the average daily weight in GIFT Nile tilapia (Oreochromis niloticus) in different regions in the state of Paraná (Brazil) was analyzed. The heritability results were high in the uni-characteristic analysis: 0.71, 0.72 and 0.67 for the cities of Palotina (PL), Floriano (FL) and Diamond North (DN), respectively. Genetic correlations estimated in bivariate analyzes were weak with values between 0.12 for PL-FL, 0.06 for PL and 0.23 for DN-FL-DN. The Spearman correlation values were low, which indicated a change in ranking in the selection of animals in different environments in the study. There was heterogeneity in the phenotypic variance among the three regions and heterogeneity in the residual variance between PL and DN. The direct genetic gain was greater for the region with a DN value gain of 198.24 g/generation, followed by FL (98.73 g/generation) and finally PL (98.73 g/generation). The indirect genetic gains were lower than 0.37 and greater than 0.02 g/generation. The evidence of the genotype x environment interaction was verified, which indicated the phenotypic heterogeneity of the variances among the three regions, weak genetic correlation and modified rankings in the different environments.

Avaliação da progênie de ovelhas Merino Australiano cruzadas com carneiro Dorper ou Southdown / Evaluation of the progeny of Australian Merino ewes crossed with Dorper or Southdown ram

O presente estudo objetivou avaliar o efeito do genótipo do carneiro (Dorper ou Southdown), do sexo e do tipo de parto sobre características de crescimento de 268 cordeiros filhos de ovelhas Merino Australiano. Até o desmame, todos os animais permaneceram sobre pastagem de trevo-vermelho (Trifolium pratense ), chicória (Cychorium intibus ), trevo-branco (Trifolium repens ), festuca (Festuca arundinacea ) e azevém (Lolium multiflorum ), com carga animal de 10 ovelhas com seus cordeiros/ha. A partir do desmame (29,95±4,94kg de peso vivo e 109,45±7,41 dias de idade), os cordeiros permaneceram sobre a mesma pastagem utilizada durante a lactação, sendo terminados posteriormente sobre um cultivo de soja (Glycine max) , com carga animal de 30 cordeiros/ha. Não foi verificado efeito do genótipo do carneiro (P>0,05) sobre nenhuma das variáveis analisadas. Por outro lado, do nascimento ao desmame e do desmame até o embarque dos cordeiros para abate, os machos (criptorquidas) apresentaram ganhos de peso diário superiores (241 e 212g/dia; 121 e 94g/dia, para machos e fêmeas, respectivamente; P≤0,001), o que proporcionou um peso vivo ao embarque 14,9% superior em relação às fêmeas (40,89 e 35,59kg, para machos e fêmeas, respectivamente; P≤0,001). Os cordeiros de parto simples apresentaram maiores (P≤0,001) pesos vivos e medidas corporais ao nascimento, bem como maior velocidade de crescimento até o desmame (239 e 214g/dia, parto simples e duplo, respectivamente; P≤0,001). Porém, após o desmame, os cordeiros de parto duplo apresentaram maior ganho de peso (98 e 117g/dia) (P≤0,05) e uma superioridade (P≤0,001) em quilogramas de cordeiros desmamados (26,80 e 49,61kg) ou embarcados (33,91 e 64,69kg) por ovelha parida. Independentemente do sexo e do tipo de parto, todos os cordeiros superaram as exigências de peso e condição corporal mínima requerida para comercialização de cordeiros pesados no Uruguai, na metade do tempo que em média ocorre com os genótipos tradicionais.

This study aimed to evaluate the effect of ram genotype (Dorper or Southdown), sex and birth type on the growth characteristics of 268 lambs from Australian Merino ewes. Until weaning all animals were kept on red clover pasture (Trifolium pretense), chicory (Cychorium intibus), white clover (Trifolium repens), fescue (Festuca arundinacea) and ryegrass (Lolium multiflorum), with a stocking rate of 10 sheep and their lambs/ha. From weaning (29.95±4.94kg of body weight and 109.45±7.41 day-old), the lambs remained on the same pasture which was used during lactation, being subsequently finished on a soybean culture (Glycine max), with a stocking rate of 30 lambs/ha. No effect of ram genotype (P>0.05) was verified on any of the variables. On the other hand, the males (criptorquidas) presented superior weight gain from birth to weaning and from weaning until shipment of lambs for slaughter, (241 and 212g/day; 121 and 94g/day, for males and females, respectively; P≤0.001), which provided a body weight at shipment 14.9% higher than the female (40.89 and 35.59kg, for males and females, respectively; P≤0.001). Lambs originated from simple delivery presented higher (P≤0.001) body weight and body measures at birth, and a higher growth rate until weaning (239 and 214g/day, simple and double delivery, respectively; P≤0.001). Therefore, after weaning, the lambs originated from double delivery presented higher weight gain (98 and 117g/day) (P≤0.05) and were superior (P≤0.001) in kilograms of weaned lambs (26.80 and 49.61kg) or shipped (33.91 and 64.69kg) per parity ewes. Regardless of the sex and birth type, all lambs overcame the weight and body conditions required for commercialization of heavy lambs in Uruguai in half the average time of traditional genotypes.

Reverse Cardiac Remodeling: A Marker of Better Prognosis in Heart Failure / Reversão da Remodelação Cardíaca: um Marcador de Melhor Prognóstico na Insuficiência Cardíaca

In heart failure syndrome, myocardial dysfunction causes an increase in neurohormonal activity, which is an adaptive and compensatory mechanism in response to the reduction in cardiac output. Neurohormonal activity is initially stimulated in an attempt to maintain compensation; however, when it remains increased, it contributes to the intensification of clinical manifestations and myocardial damage. Cardiac remodeling comprises changes in ventricular volume as well as the thickness and shape of the myocardial wall. With optimized treatment, such remodeling can be reversed, causing gradual improvement in cardiac function and consequently improved prognosis.

Na síndrome da insuficiência cardíaca, a disfunção do miocárdio gera um aumento da atividade neuro-hormonal, que é um mecanismo adaptativo e compensatório em resposta à redução do débito cardíaco. A atividade neuro-hormonal é estimulada inicialmente na tentativa de manter o paciente compensado, mas quando permanece aumentada, contribui para a intensificação das manifestações clínicas e do dano miocárdico. A remodelação cardíaca consiste nas alterações no volume do ventrículo bem como na espessura e forma da parede do miocárdio. Com o tratamento otimizado, pode ocorrer a reversão da remodelação, com melhora gradual da função cardíaca e consequente melhora do prognóstico.

Características de desempenho e de carcaça em diferentes genótipos de codornas de corte / Performance and carcass traits of different meat type genotypes

Objetivou-se com este trabalho comparar e correlacionar as características de desempenho e de carcaça em codornas de corte do nascimento aos 35 dias de idade. Foram utilizadas 1176 codornas de um dia, machos e fêmeas, de sete genótipos de codornas de corte (EV1, EV2, UFV1, UFV2, UFV3, LF1 e LF2), distribuídas em delineamento inteiramente ao acaso, com ensaio fatorial 7x2 (genótipo x sexo), em sete repetições com 12 codornas por unidade experimental. As codornas foram pesadas individualmente do nascimento aos 35 dias de idade, em intervalos semanais. Aos 35 dias de idade, dois machos e duas fêmeas de cada genótipo e repetição foram amostrados e abatidos para avaliação do peso de carcaça e dos cortes nobres. As análises estatísticas foram conduzidas utilizando-se o procedimento GLM e CORR com a opção MANOVA do SAS para avaliar as diferenças entre os genótipos e a correlação entre as variáveis. Não houve interação (P≥0,05) entre genótipo e sexo para as características de desempenho (peso e ganho de peso nas diferentes idades). Entretanto, houve efeito significativo da interação genótipo x sexo (P<0,05) para as características de pesos de carcaça, peito e coxa+sobrecoxa. Em geral, as codornas dos grupos genéticos UFV1, UFV2 e UFV3 foram as mais pesadas dos sete aos 35 dias de idade e apresentaram maiores rendimentos de carcaça. Como observado pelas correlações fenotípicas, a tendência é que codornas que apresentam maior peso corporal e ganho de peso irão apresentar maior peso de carcaça e dos seus principais cortes.(AU)

This study was carried out to compare and relate the performance and carcass traits of different quail genotypes from hatch to 35 days of age. A total of 1176 one-day-old quails of both sexes were allotted in a completely randomized experimental design, in a 7x2 factorial scheme (genotypes x sexes), in seven replicates with 12 quails per experimental unit. Quails of each genotype were weighed weekly from hatch to 35 days of age. At 35 days of age two males and two females of each genotype and replicate were sampled and slaughtered to evaluate carcass weight and main cut yield. Statistical analyses were performed by GLM and CORR procedure from the Statistical Analysis System (SAS, 2000, version 9.0), with the MANOVA option of the SAS device to assess the differences between the genotypes and the correlation between variables. There was no interaction (P≥0.05) between genotype and sex with the performance characteristics of weight and weight gain. However, there was a significant effect of genotype x sex (P<0.05) for the characteristics carcass,breast, thigh and drumstick weights. In general, quails of genetic groups UFV1, UFV2 and UFV3 were heavier from 7 to 35 days of age. We observed that for the correlation the tendency is that quail that showed higher body weight and weight gain will have greater housing and main cuts weight.(AU)

Reabilitação da deglutição em pacientes traqueostomizados disfágicos sob ventilação mecânica em unidades de terapia intensiva: um estudo de factibilidade / Swallowing rehabilitation of dysphagic tracheostomized patients under mechanical ventilation in intensive care units: a feasibility study

Objetivo: Avaliar a factibilidade da implantação precoce de um programa de reabilitação da deglutição em pacientes traqueostomizados com disfagia e sob ventilação mecânica. Métodos: Estudo prospectivo realizado em unidades de terapia intensiva de um hospital universitário. Incluímos pacientes hemodinamicamente estáveis e submetidos à ventilação mecânica por pelo menos 48 horas e há no mínimo 48 horas com traqueostomia e nível adequado de consciência. Os critérios de exclusão foram cirurgia prévia na cavidade oral, faringe, laringe e/ou esôfago, presença de doenças degenerativas ou história pregressa de disfagia orofaríngea. Todos os pacientes foram submetidos a um programa de reabilitação da deglutição. Antes e após o tratamento de reabilitação da deglutição, foram determinados um escore estrutural orofaríngeo, um escore funcional de deglutição, e um escore otorrinolaringológico estrutural e funcional. Resultados: Foram incluídos 14 pacientes. A duração média do programa de reabilitação foi de 12,4 ± 9,4 dias, com média de 5,0 ± 5,2 dias sob ventilação mecânica. Onze pacientes puderam receber alimentação por via oral enquanto ainda permaneciam na unidade de terapia intensiva após 4 (2 - 13) dias de tratamento. Todos os escores apresentaram melhora significante após o tratamento. Conclusão: Neste pequeno grupo de pacientes, a implantação de um programa precoce de reabilitação da deglutição foi factível, mesmo em pacientes sob ventilação mecânica. .

Objective: The aim of the present study was to assess the feasibility of the early implementation of a swallowing rehabilitation program in tracheostomized patients under mechanical ventilation with dysphagia. Methods: This prospective study was conducted in the intensive care units of a university hospital. We included hemodynamically stable patients under mechanical ventilation for at least 48 hours following 48 hours of tracheostomy and with an appropriate level of consciousness. The exclusion criteria were previous surgery in the oral cavity, pharynx, larynx and/or esophagus, the presence of degenerative diseases or a past history of oropharyngeal dysphagia. All patients were submitted to a swallowing rehabilitation program. An oropharyngeal structural score, a swallowing functional score and an otorhinolaryngological structural and functional score were determined before and after swallowing therapy. Results: We included 14 patients. The mean duration of the rehabilitation program was 12.4 ± 9.4 days, with 5.0 ± 5.2 days under mechanical ventilation. Eleven patients could receive oral feeding while still in the intensive care unit after 4 (2 - 13) days of therapy. All scores significantly improved after therapy. Conclusion: In this small group of patients, we demonstrated that the early implementation of a swallowing rehabilitation program is feasible even in patients under mechanical ventilation. .

Insulin-like growth factor 1 gene (CA)n repeats and a variable number of tandem repeats of the insulin gene in Brazilian children born small for gestational age

OBJECTIVE: To investigate the influence of (CA)n repeats in the insulin-like growth factor 1 gene and a variable number of tandem repeats of the insulin gene on birth size in children who are small or adequate-sized for gestational age and to correlate these polymorphisms with serum insulin-like growth factor 1 levels and insulin sensitivity in children who are small for gestational age, with and without catch-up growth. PATIENTS AND METHODS: We evaluated 439 infants: 297 that were adequate-sized for gestational age and 142 that were small for gestational age (66 with and 76 without catch-up). The number of (CA)n repeat in the insulin-like growth factor 1 gene and a variable number of tandem repeats in the insulin gene were analyzed using GENESCAN software and polymerase chain reaction followed by enzymatic digestion, respectively. Clinical and laboratory data were obtained from all patients. RESULTS: The height, body mass index, paternal height, target height and insulin-like growth factor 1 serum levels were higher in children who were small for gestational age with catch-up. There was no difference in the allelic and genotypic distributions of both polymorphisms between the adequate-sized and small infants or among small infants with and without catch-up. Similarly, the polymorphisms were not associated with clinical or laboratory variables. CONCLUSION: Polymorphisms of the (CA)n repeats of the insulin-like growth factor 1 gene and a variable number of tandem repeats of the insulin gene, separately or in combination, did not influence pre- or postnatal growth, insulin-like growth factor 1 serum levels or insulin resistance. .

Physical characteristics at different ages / Características físicas en diferentes edades

The purpose of this study was to study, observe, and clarify the dynamics of physical growth, as well as changes of some morphometrical and physiological variables of Kosovo population. 17,894 males from Kosovo between 6 and 51 years of age and older, were measured: body height, body weight, BMI, systolic pressure, diastolic pressure, heart rate, and VO max were recorded. The measurement data were processed through these descriptive statistical parameters: Mean, Standard-Deviation and the Coefficient of Variation, SD shows the similar dispersion of results between one age and another. CV signifies the reliability of the measurements that were carried out. The curve of body height for individuals between 6 and 17 years of age shows increases, for individuals between 18 and 40 years of age shows stable values, while for indiividuals above 40 years of age indicate a decrease.Body height difference between adults shows that adultsbetween 18 and 30 years old have the higher body height values, compared with the other two groups of tested adults. Body weight for individualsbetween 6 and 50 years old shows consistent increase of value. In individuals above 51 years of age, body weight decreases rapidly. According to BMIvalues individuals between 6 and 13 years of age were underweight. Those between 14 and 35 years of age, as well as those above 51 years of age showed normal weight. On the other hand, those between 36 and 50 years of age were slightly overweight. Systolic and diastolic blood pressure values were higher as age increased, however were not above normal values. The best results of HR and VO2max were reported in adults between 19 and 27 years of age.

El objetivo de este trabajo fue estudiar, observar, y para aclarar la dinámica de crecimiento físico, así como los cambios de algunas variables morfométricas y fisiológicas de la población de Kosovo. En 17.894 hombres en Kosovo, de entre 6 y 51 años, se tomaron las siguientes medidas: Altura y peso corporal, IMC, presiones sistólica y diastólica, frecuencia cardíaca, VO2 máx. Los datos fueron procesados a través de los siguientes parámetros estadísticos descriptivos: media, desviación estándar y coeficiente de variación. La DS muestra la dispersión de los resultados de acuerdo a la edad. CV determina la fiabilidad de las mediciones que se hicieron. La curva de la altura del cuerpo entre 6-17 años de edad aumentó entre los 18 y 40 años de edad, mientras que para individuos de más de 40 años la curva disminuye. La altura corporal mostró que los adultos entre 18-30 años son más altos, en comparación con otros dos grupos. El peso corporal aumenta desde los 6 a los 50 años edad, mientras que después de los 51 años se produce rápidamente su disminución. De acuerdo a los valores de IMC, los individuos entre 6-13 años de edad presentaban bajo peso. Los individuos entre 14-35 años y superiores a 51 años presentaban un peso normal. Los individuos entre 36-50 años, presentaron un ligero sobrepeso. Aumentaron las presiones sistólica y diastólica de acuerdo a la edad, pero no por encima del valor normal. Los mejores resultados de la frecuencia cardiaca y VO2máx se alcanzaron en los adultos entre 19 y 27 años.

Comparison of Phenotypic and Genetic Performance of Local Silkworm Groups and Two Commercial Lines

Five Iranian native silkworm groups: Baghdad, Khorasan Orange, Guilan Orange, Khorasan Pink, Khorasan Lemon, and 107 and 110 commercial lines (12 families from each breed) were randomly selected and reared during 2003-2005 (five generations in spring and autumn). In each family, 30 male and 30 female cocoons were individually recorded for weight, shell weight and shell ratio. From among the native groups, the highest average in all three traits belonged to Baghdad and Khorasan Pink, and the lowest to Khorasan Orange and Khorasan Lemon. From among the commercial lines, the highest average in all three traits belonged to 107. In comparing heritabihty for cocoon weight in native groups, the highest heritabihty belonged to Guilan Orange (0.5147) and Khorasan Orange (0.5036) and the lowest heritabihty belonged to Khorasan Pink (0.0967). In the two other traits, the highest heritabihty belonged to Khorasan Orange and Baghdad and the lowest to Khorasan Pink. In the commercial lines, linellO had higher heritabihty than linel07 for cocoon weight and cocoon shell weight. In all the groups, genetic correlations between cocoon weight and cocoon shell weight were high, expect for the Baghdad group. There was médium or low genetic correlation among cocoon weight, cocoon shell weight and cocoon shell ratio.

Sistema leptina-melanocortinas en la regulación de la ingesta y el peso corporal / Leptin-melanocortin system, body weight regulation and obesity

Obesity is a multifactorial disease that is rarely associated to single gene defects. However, due to their direct cause-effect relationships, those genetic defects that cause some forms of monogenic obesity are relevant in the study of mechanisms that contribute to increased energy intake and body fat accumulation. Most of the genes that have been shown to cause monogenic obesity are related to the leptin-melanocortin system. The functionality of this system has been elucidated through natural mutations (Agouti, ob and db) in mice and knock-out models. Mutations related to human monogenic obesity have been described in leptin, leptin receptor, proopiomelanocortin, prohormone convertase 1 or melanocortin receptor 4 genes. Therapy with human recombinant leptin in patients with genetic deficiency of the hormone is an effective medical treatment of obesity, although only applicable to very few families. The use of leptin-melanocortin agonists, drugs to avoid leptin resistance or combinations of treatments with leptin and other satiating peptides are currently being investigated for multifacotiral human obesity (Rev Méd Chile 2009; 137:1225-34).

Influência da interação genótipo x ambiente sobre o peso à desmama em bovinos da raça Nelore / Influence of genotype x environment interaction on weaning weight in Nellore cattle

Avaliaram-se os efeitos da interação genótipo x ambiente sobre a característica peso à desmama em bovinos da raça Nelore. Foram analisados 45.697 registros de peso à desmama ajustados para 205 dias, originários de três fazendas. Estas foram organizadas em duplas e analisadas por meio de análises de características únicas, considerando cada dupla como um só rebanho. Em seguida, as mesmas duplas foram submetidas a análises de características múltiplas, em que o peso à desmama de cada fazenda foi considerado como característica distinta dentro de sua respectiva dupla. Os componentes de variância foram estimados por máxima verossimilhança restrita, utilizando-se o programa MTDFREML. Os coeficientes de correlação genética encontrados variaram de 0,79 a 1,00. Foram também estimadas as diferenças esperadas de progênies (DEPs), utilizando-se o mesmo programa computacional. Posteriormente, os touros foram ordenados conforme os valores de suas respectivas DEPs, selecionando-se os 30 por cento mais bem classificados. Com base nas DEPs, estimou-se a correlação momento-produto de Pearson para os animais selecionados em dois diferentes ambientes, de modo a verificar as diferenças de ordenação. As correlações de Pearson estenderam-se de 0,96 a 0,99, sugerindo pequeno ou nenhum efeito da interação genótipo x ambiente nos rebanhos incluídos neste estudo.

The effects of genotype x environment interaction on weaning weight in Nellore cattle were evaluated. A total of 45,697 records of weaning weight adjusted for 205 days obtained from three farms were analyzed. The farms were organized in pairs and analyzed by single-trait analysis, as if they were only one herd. Afterwards, the pairs were submitted to multiple-trait analyses, once the same trait was considered as a distinct trait in each farm. The variance components were estimated by Restricted Maximum Likelihood, using the program MTDFREML. The genetic correlation coefficients varied from 0.79 to 1.00. The Expected Progeny Differences (EPD) were estimated using de same computational program. Later, the sires were organized in accordance with their EPD, selecting the 30 percent best classified sires. Pearson's correlations were estimated among the EPD of animals selected in two different environments, in order to verify changes in their classification. The Pearson's correlations extended from 0.96 to 0.99, suggesting small or inexistent effect of genotype x environment interaction in the herds included in this study.

Perfil antropométrico de jugadores profesionales de voleibol sudamericano / Anthropometric profile of professional volleyball sudamerican players

El voleibol es beneficiado por la aplicación de la antropometría, tanto por la evaluación de la composición corporal, que predice los rendimientos fisiológico y deportivo y define comportamientos mecánicos, para determinar la posición más eficiente dentro del campo de juego, de acuerdo a las características antropométricas. Se evaluaron las selecciones nacionales adultas de Colombia, Paraguay, Uruguay, Venezuela y la Selección Juvenil de Chile, utilizando el método de fraccionamiento corporal y el Somatotipo de Heath-Carter. El equipo Vicecampeón Sudamericano, Venezuela, fue el que tenía mayores porcentajes de masa muscular y bajos porcentajes de masa adiposa. El somatotipo de los equipos presentaba una mesomorfismo aumentado, seguido de un alto ectomorfismo, obteniendo la clasificación de individuos ecto-mesomórficos. La utilización de los datos obtenidos contribuirá a formar un modelo de jugador con una morfología estructuralmente ideal, capaz de afrontar competencias de alto nivel competitivo. La información obtenida ayuda a orientar el trabajo deportivo de manera certera y eficiente para la detección de talentos o entrenamiento de futuros voleibolistas profesionales.

The application of anthropometry provides many benefits to the sport of volleyball, such as in the evaluation of body composition, predicting physiological and sporting performance and defining mechanical behavior, from which the most efficient position in the court may be determined in terms of anthropometric characteristics. The national teams from Columbia, Paraguay, Uruguay and Venezuela were evaluated along with the Chilean youth team, using the method of body division and the Heath-Carter Somato type. The South American runners-up, Venezuela, possess greater percentages of muscle mass and low percentages for adipose tissue mass. The somatotype of the teams presents an increased mesomorphy, followed by high ectomorphy, thus classifying the individuals as ecto-mesomorphs. The use of the data acquired allows the formation of a model of the morpho-structurally ideal player for high level competition. The information obtained guides physical preparation in an accurate and efficient way, leading to the detection of new talent or helping train future professional volleyball players.

Genetic variants influencing effectiveness of weight loss strategies: [review] / Variantes genéticos influenciando a efetividade das estratégias de perda de peso: [revisão]

Body weight excess has an increasingly high prevalence in the world. Obesity is a complex disease of multifactorial origin with a polygenic condition affected by environmental factors. Weight loss is a primary strategy to treat obesity and its morbidities. Weight changes through life depend on the interaction of environmental, behavioral and genetic factors. Interindividual variation of weight loss in response to different types of interventions (behavioral, caloric restriction, exercise, drug or surgery) has been observed. In this article, currently available data on the role of candidate gene polymorphisms in weight loss are reviewed. Even though control of weight loss by genotype was described in twin and family studies, it is premature to recommend use of genotyping in the design of therapeutic diets or drug treatment. Future studies will have to be large in order to assess the effects of multiple polymorphisms, and will have to control factors other than diet.

A prevalência do excesso de peso cresce no mundo todo. De origem multifatorial, a obesidade é uma doença complexa, com condição poligênica afetada por fatores ambientais. A perda de peso é a estratégia primária utilizada para prevenir e tratar a obesidade bem como suas comorbidades. Mudanças de peso durante a vida dependem da interação entre fatores ambientais, comportamentais e genéticos. Observa-se grande variação da perda de peso entre indivíduos em resposta a diferentes modelos de intervenções (comportamentais, restrições da ingesta cálorica, exercícios físicos, drogas antiobesidade ou cirurgias). Este artigo é uma revisão atual da literatura disponível, que busca abordar o papel dos polimorfismos dos genes candidatos à obesidade e sua influência na perda de peso. Apesar da interação do genótipo na perda de peso corporal, descrita nos estudos de gêmeos e familiares, é prematuro recomendar o uso da genotipagem para estratégias de perda de peso. É necessário ampliar as pesquisas sobre os efeitos sinérgicos dos polimorfismos genéticos com coorte maior e associá-los não somente à restrição alimentar mas também às outras intervenções que auxiliam na perda de peso.

The polymorphisms of bovine cocaine- and amphetamine-regulated transcripts and their associations with cattle (Bos taurus) growth traits.

We investigated the polymorphisms of bovine cocaine- and amphetamine-regulated transcripts (CART ). The coding and regulating regions of CART were screened in 7 cattle breeds by the single-stranded conformation polymorphism (SSCP) technique. The four loci (C1,C2, C3 and C4) studied were all polymorphic. Polymerase chain reaction (PCR) products representing different SSCP variants were sequenced and a total of 9 single-nucleotide polymorphisms (SNPs) were found. The associations between polymorphic loci and the growth traits of Nanyang cattle were analysed. The results indicated that genotype A1A1 of the C1 locus was associated with a higher body weight (P less than 0.05) than heterozygous A1B1. Genotype A2A2 of the C2 locus was associated with lower body weight and average daily weight gain (P < or = 0.001) than heterozygous A2B2. C3 and C4 loci had no significant effect on Nanyang cattle growth traits (P > 0.05).

Interação genótipo x ambiente e estimativas de parâmetros genéticos dos pesos aos 205 e 365 dias de idade de bovinos Nelore / Genotype by environment interaction and genetic parameter estimates for 205 and 365 body weight of Nelore cattle

Dados de pesos aos 205 (P205) e 365 (P365) dias de idade, de 46.408 animais Nelore, nascidos entre 1976 e 2000, provenientes de 530 rebanhos dos diversos estados brasileiros, foram utilizados para avaliar as interações genótipo x ambiente (IGA) e estimar herdabilidades direta e materna dos pesos pelo método da máxima verossimilhança restrita. O modelo estatístico utilizado incluiu efeitos fixos de grupo contemporâneo, idade da vaca ao parto (covariável) e efeitos aleatórios genéticos aditivo direto e materno. As correlações genéticas, estimadas para as características P205 e P365, cada uma considerada como característica distinta em cada uma das regiões Sul (S), Sudeste (SE), Centro-Oeste (CO), Norte (N) e Nordeste (NE), foram, respectivamente, 0,86 e 0,84, 0,64 e 0,35, 0,75 e 0,42, 0,79 e 0,86, 0,92 e 0,81, 0,95 e 0,83, 0,83 e 1,00, 0,88 e 0,81, 0,33 e 0,85, 0,63 e 0,99 para S e SE, S e CO, S e N, S e NE, SE e CO, SE e N, SE e NE, CO e N, CO e NE e N e NE. As baixas correlações genéticas indicaram que há efeito da interação genótipo x ambiente nas combinações que envolvem as regiões S/CO, S/N, S/NE, CO/NE e N/NE para P205 dias de idade e S/CO e S/N para P365 dias de idade, havendo, portanto, necessidade de avaliação genética regional quando se consideram regiões bastante distintas.

Body weight records at 205 (205BW) and 365 (365BW) days of age of 46,408 Nelore animals, born from 1976 to 2000 period in 530 Nelore herds of several states of Brazil, were used to evaluate genotype by environment interactions and to estimate genetic and maternal heritability by restricted maximum likelihood methodology. The statistical model included the fixed effects of contemporary group and age of cow (covariate), and the random direct and maternal additive genetic effects. The genetic correlation for 205BW and 365BW, each one considered as different traits in each of the South (S), Southeast (SE), Central west (CO), North (N) and Northeast (NE) regions were 0.86 and 0.84, 0.64 and 0.35, 0.75 and 0.42, 0.79 and 0.86, 0.92 and 0.81, 0.95 and 0.83, 0.83 and 1.00, 0.88 and 0.81, 0.33 and 0.85, 0.63 and 0.99 for S/SE, S/CO, S/N, S/NE, SE/CO, SE/N, SE/NE, CO/N, CO/NE and N/NE, respectively. There is a significant genotype by environment interaction for 205BW in the combination involving the S/CO, S/N, S/NE, CO/NE, and N/NE regions. There are significant genotype by environment interaction effects in the combination involving the S/CO and S/N regions for 365BW. Based on genetic x environment interaction results, regional genetic evaluation is recommend for the very distinct regions.

Tabagismo e variação ponderal: a fisiopatologia e genética podem explicar esta associação?: [revisão] / Smoking and changes in body weight: can physiopathology and genetics explain this association?: [review]

O tabagismo é a principal causa de morte prevenível na maioria dos países, inclusive no Brasil. Parar de fumar é uma estratégia importante para reduzir a morbidade e mortalidade associada às doenças tabaco-relacionadas. Sabe-se da relação inversa entre uso de nicotina e peso corporal, onde o índice de massa corporal tende a ser menor em fumantes quando comparados aos não fumantes. Além disso, abstinência tabágica resulta em aumento de peso, sendo que ex-fumantes geralmente aumentam de 5 a 6 kg, mas cerca de 10 por cento adquirem mais de 10 kg. O tratamento farmacológico para a cessação do tabagismo pode atenuar este ganho de peso. O aumento de peso na cessação do tabagismo como contributório à epidemia de obesidade é pouco estudado. Nos EUA, calcula-se que a fração do problema atribuível à cessação do tabagismo seja de 6 por cento para homens e 3,2 por cento para mulheres. Os mecanismos não são claros, mas há evidências mostrando que a dopamina e serotonina diminuem a ingestão alimentar. A administração de nicotina por qualquer via eleva agudamente os níveis destes neurotransmissores no cérebro, causando menor necessidade de ingestão energética e diminuindo o apetite. Além disso, a nicotina tem efeito direto no metabolismo do tecido adiposo, influenciando a taxa de ganho ponderal após a cessação do tabagismo. A leptina, grelina e neuropeptídio Y são peptídeos que podem contribuir para esta relação inversa entre nicotina e índice de massa corporal, em um papel ainda não determinado como conseqüente ou causador das variações ponderais.

Tobacco use is the leading preventable cause of death in most countries, including Brazil. Smoking cessation is an important strategy for reducing the morbidity and mortality associated with tobacco-related diseases. An inverse relationship between nicotine use and body weight has been reported, in which body weight tends to be lower among smokers than among nonsmokers. Smoking abstinence results in an increase in body weight for both males and females. On average, sustained quitters gain from 5 to 6 kg, although approximately 10 percent gain more than 10 kg. Pharmacological treatment for smoking cessation attenuates weight gain. The importance of smoking cessation as a contributing cause of the current obesity epidemic has been little studied. In the USA, the rate of obesity attributable to smoking cessation has been estimated at approximately 6.0 and 3.2 percent for males and females, respectively. Although the mechanisms are unclear, there is evidence that dopamine and serotonin are appetite suppressants. The administration of nicotine, regardless of the delivery system, acutely raises the levels of these neurotransmitters in the brain, reducing the need for energy intake and consequently suppressing appetite. In addition, nicotine has a direct effect on adipose tissue metabolism, influencing the rate of weight gain following smoking cessation. Leptin, ghrelin and neuropeptide Y are substances that might constitute factors involved in the inverse relationship between nicotine and body mass index, although their roles as determinants or consequences of this relationship have yet to be determined.

Parâmetros genéticos entre características de leite, de peso e a idade ao primeiro parto em gado mestiço leiteiro (Bos taurus x Bos indicus) / Genetic parameters between milk traits, weight traits and age at first calving in crossbreed dairy cattle (Bos taurus x Bos indicus)

Foram estimadas as correlações genéticas entre características de produção de leite (produção de leite, gordura, proteína e duração da lactação em até 305 dias, na primeira lactação), características de peso (taxa de crescimento de novilhas entre 12-24 meses e peso médio de vacas) e idade ao primeiro parto, em uma população de fêmeas Mestiço Leiteiro Brasileiro (MLB), por meio de metodologia REML, sob modelo animal. As estimativas de herdabilidade das características estudadas na ordem acima foram, respectivamente, 0,28± 0,08, 0,30±0,11, 0,28±0,09, 0,19±0,07, 0,18±0,06, 0,42±0,10 e 0,48±0,12. As correlações genéticas entre peso médio da vaca e a produção de leite, gordura e proteína foram, respectivamente, -0,22±0,22, -0,49±0,31 e -0,22±0,23 e da taxa de crescimento das novilhas com a produção de leite, gordura e proteína foram respectivamente, -0,59±0,35, -0,73±0,44 e -0,62±0,37. As correlações genéticas entre produção de leite, peso médio das vacas e taxa de crescimento das novilhas com idade ao primeiro parto foram respectivamente, 0,05±0,18, -0,05±0,18 e 0,02±0,20. A alta correlação genética (0,93±0,02) entre produção de leite e duração da lactação indicou que não se deve remover a variação na duração da lactação na seleção de gado leiteiro tropical

Genetic correlations between milk production (milk, fat, protein yield lactation length in 305-d lactation), live weight (average cow live weight, growth rate between 12-24 mo) and age at first calving traits were estimated in a population of Mestiço Leiteiro Brasileiro (MLB) females using REML methodology and animal model. The estimates of heritability were respectively, 0.28± 0.08, 0.30±0.11, 0.28±0.09, 0.19±0.07, 0.18±0.06, 0.42±0.10 and 0.48±0.12 for those traits. Genetic correlations between milk, fat and protein yield with cow average weight were, respectively, -0.22±0.22, -0.49±0.31, -0.22±0.23, and between milk, fat and protein yield with heifer live weight gain, -0.59±0.35, -0.73±0.44, -0.62±0.37 as well. Genetic correlations between milk yield, cow average weight and heifer live weight gain with age at first calving were, respectively, 0.05±0.18, -0.05±0.18, 0.02±0.20. The high genetic correlation between milk production and lactation length (0.93±0.02) indicated that variation of the lactation length should not be removed when selecting tropical dairy cattle

Genetic parameters for growth traits of a Brazilian Bos taurus x Bos indicus beef composite

The genetic analysis of composite data is very complicated, mainly because it is necessary to adjust data to the effects of heterosis and breed complementarity, and because there is usually considerable confounding of these data with several other effects, such as contemporary group effects, breed composition of the animal and maternal breed composition, among others. Data on birth weight (n = 151,083), weaning weight adjusted to 205 days (n = 137,257), yearling weight adjusted to 390 days (n = 61,410), weight gain from weaning to yearling (n = 56,653), and scrotum circumference (n = 23,323) and muscle score (n = 54,770), both adjusted to 390 days, from Bos taurus x Bos indicus composite beef calves born from 1994 to 2003 were analyzed to estimate (co)variance components and genetic parameters of growth traits. The animals belonged to the Montana Tropical® program. Estimation was made by three models that approach adjustment to heterozygosis in order to suggest the best model. The RM model included contemporary groups, class of age of dam, outcrossing percentages for direct and maternal effects, and direct and maternal additive genetic breed effects as covariates; the R model was the same as RM, but without additive maternal breed effects, and H was the same as RM, but not considering any additive breed effect. Both R2 values and consistency of genetic parameters indicate that the more complex model (RM), which considers maternal and individual additive genetic breed effect, produces the best estimates when compared to other models. The R model seems to overestimate (co)variance components. The magnitudes of direct and maternal heritability estimates, obtained in this study, would permit genetic improvement for weight and growth traits, as much by selection of direct genetic effects for weight and growth as for the improvement of maternal performance, but in different lineages. Therefore, the correlations between these effects were unfavorable.