clag9 Is Not Essential for PfEMP1 Surface Expression in Non-Cytoadherent Plasmodium falciparum Parasites with a Chromosome 9 Deletion

BACKGROUND: The expression of the clonally variant virulence factor PfEMP1 mediates the sequestration of Plasmodium falciparum infected erythrocytes in the host vasculature and contributes to chronic infection. Non-cytoadherent parasites with a chromosome 9 deletion lack clag9, a gene linked to cytoadhesion in previous studies. Here we present new clag9 data that challenge this view and show that surface the non-cytoadherence phenotype is linked to the expression of a non-functional PfEMP1. METHODOLOGY/PRINCIPAL FINDINGS: Loss of adhesion in P. falciparum D10, a parasite line with a large chromosome 9 deletion, was investigated. Surface iodination analysis of non-cytoadherent D10 parasites and COS-7 surface expression of the CD36-binding PfEMP1 CIDR1α domain were performed and showed that these parasites express an unusual trypsin-resistant, non-functional PfEMP1 at the erythrocyte surface. However, the CIDR1α domain of this var gene expressed in COS-7 cells showed strong binding to CD36. Atomic Force Microscopy showed a slightly modified D10 knob morphology compared to adherent parasites. Trafficking of PfEMP1 and KAHRP remained functional in D10. We link the non-cytoadherence phenotype to a chromosome 9 breakage and healing event resulting in the loss of 25 subtelomeric genes including clag9. In contrast to previous studies, knockout of the clag9 gene from 3D7 did not interfere with parasite adhesion to CD36. CONCLUSIONS/SIGNIFICANCE: Our data show the surface expression of non-functional PfEMP1 in D10 strongly indicating that genes other than clag9 deleted from chromosome 9 are involved in this virulence process possibly via post-translational modifications

Perfil dietético, estado nutricional e prevalência de obesidade centralizada em praticantes de futebol recreativo Perfil dietético, estado nutricional y prevalencia de obesidad centralizada en practicantes de fútbol recreativo Dietetic profile, nutritional status and prevalence of central obesity in recreative soccer practitioners

O objetivo do estudo foi avaliar o perfil dietético, estado nutricional e a prevalência de obesidade centralizada (OC) em praticantes de futebol recreativo. MÉTODOS: Amostra: 40 indivíduos (38,6 &plusmn; 7,4 anos) do gênero masculino. Para a avaliação do consumo habitual (CH), foi utilizado um questionário quantitativo de freqüência alimentar. O estado nutricional foi avaliado por meio do índice de massa corporal (IMC). A OC foi definida como circunferência abdominal (CIRCAB) superior a 102cm. RESULTADOS: Predomínio de indivíduos da classe social "B" (80,0%), brancos (67,5%), casados (62,5%) e funcionários públicos (52,5%). As médias mostraram: massa corporal de 77,2 &plusmn; 11,8kg, estatura de 1,71 &plusmn; 0,1m, IMC de 26,4 &plusmn; 3,1kg/m², CIRCAB de 92,3 &plusmn; 8,8cm, CH de 2.623,2 &plusmn; 438,5kcal. As proporções de nutrientes foram de 48,2 &plusmn; 5,7% de carboidratos, 17,6 &plusmn; 2,4% de proteínas, 34,9 &plusmn; 4,2% de lipídeos totais, 568,2 &plusmn; 112,7mg de colesterol e 20,2 &plusmn; 6,1g de fibras dietéticas. No estado nutricional, 35,0% são eutróficos, 52,5% apresentam sobrepeso e 12,5% são obesos. Em relação ao padrão de obesidade, 12,5% apresentam gordura centralizada. Entre as correlações observou-se forte associação entre CIRCAB x IMC (r = 0,91) e CIRCAB x massa corporal (r = 0,88). CONCLUSÃO: Os futebolistas devem ser orientados sobre a importância da adequação nutricional para melhora da qualidade da vida e do desempenho esportivo, fato relacionado com as proporções de nutrientes encontrados, que evidenciaram reduzida ingestão de carboidratos e alta ingestão de proteínas e colesterol dietético. O estado nutricional mostrou valores prevalentes de sobrepeso e obesidade. A OC mostrou-se evidente, fato preocupante devido à associação desse padrão de obesidade com várias doenças crônicas não-transmissíveis.<br>El objetivo de este estudio ha sido el de evaluar el perfil dietético, estado nutricional y la prevalencia de la obesidad centralizada (OC) en practicantes de fútbol recreativo. MÉTODOS: Muestra: 40 individuos (38,6 &plusmn; 7,4 años) del género masculino. Para la evaluación del consumo habitual (CH), fue utilizado un cuestionario cuantitativo de la frecuencia alimentar. El estado nutricional fue evaluado mediante el Índice de Masa Corporal (IMC). La OC fue definida como la circunferencia abdominal (CIRCAB) superior a 102cm. RESULTADOS: Predominio de individuos de clase social "B" (80,0%), blancos (67,5%), casados (62,5%) y funcionarios públicos (52,5%). Las medias mostraron: masa corporal de 77,2 &plusmn; 11,8kg, estatura 1,71 &plusmn; 0,1m, IMC 26,4 &plusmn; 3,1kg/m², CIRCAB 92,3 &plusmn; 8,8cm, CH 2623,2 &plusmn; 438,5kcal y las proporciones de nutrientes fue 48,2 &plusmn; 5,7% carbohidratos, 17,6 &plusmn; 2,4% proteínas, 34,9 &plusmn; 4,2% lípidos totales, 568,2 &plusmn; 112,7mg colesterol y 20,2 &plusmn; 6,1g fibras dietéticas. En el estado nutricional, 35,0% son eutróficos, 52,5% presentan sobrepeso y 12,5% son obesos. En relación al padrón de obesidad, 12,5% presentan grasa centralizada. Entre las correlaciones se observó una fuerte asociación entre CIRCAB X IMC (r = 0,91) y CIRCAB X masa corporal (r = 0,88). CONCLUSIÓN: Los futbolistas deben ser orientados sobre la importancia de la adecuación nutricional para mejorar la calidad de vida y el desempeño deportivo, hecho éste relacionado con las proporciones de nutrientes encontrados que evidenciaron reducida ingestión de carbohidratos y alta ingestión de proteínas y colesterol dietético. El estado nutricional mostró valores de prevalencia de sobrepeso y obesidad. La OC se mostró evidente, hecho bastante preocupante debido a la asociación de este padrón de obesidad con varias enfermedades crónicas no transmisibles.<br>The aim of the study was to evaluate the diet profile, nutritional status and centralized obesity (CO) prevalence in recreative soccer practitioners. METHODS: Sample: 40 male individuals (38.6 &plusmn; 7.4 years). To evaluate the habitual consumption (HC) it was used a quantitative of meal frequency. The nutritional status was evaluated by the Body Mass Index (BMI). The CO was defined as waist circumference (WCIRC) above 102 cm. RESULTS: There was a predominance of "B" social class individuals (80.0%), white ones (67.5%), married (62.5%) and public workers (52.5%). The average showed: body mass of 77.2 &plusmn; 11.8 kg, as high as 1.71 &plusmn; 0.1 m, BMI 26.4 &plusmn; 3.1 kg/m² and WCIRC 92.3 &plusmn; 8.8 cm, HC 2623.2 &plusmn; 438.5 kcal and the nutrients proportions was 48.2 &plusmn; 5.7% carbohydrates, 17.6 &plusmn; 2.4% proteins, 34.9 &plusmn; 4.2% total fat, 568.2 &plusmn; 112.7 mg cholesterol and 20.2 &plusmn; 6.1 g diet fibers. In relation to nutritional status, 35.0% are eutrophic, 52.5% present overweight and 12.5% present obesity. In relation to the obesity pattern, 12.5% present centralized fat. Among the correlations it was observed a strong association between WCIRC x IMC (r = 0.91) and WCIRC x body mass (r = 0,88). CONCLUSION: The soccer practitioners must be orientated over the nutritional adequation importance to life quality and sports practice, fact that is related to nutrients proportions that showed carbohydrates uptake reduction and high cholesterol and proteins uptake. The nutritional status showed values prevalence of overweight and obesity. The OC showed evident, that is dangerous because of the association of this obesity pattern with various chronic diseases that aren't transmissible