RESUMEN
BACKGROUND: All viruses in the family Bunyaviridae possess a tripartite genome, consisting of a small, a medium, and a large RNA segment. Bunyaviruses therefore possess considerable evolutionary potential, attributable to both intramolecular changes and to genome segment reassortment. Hantaviruses (family Bunyaviridae, genus Hantavirus) are known to cause human hemorrhagic fever with renal syndrome or hantavirus pulmonary syndrome. The primary reservoir host of Sin Nombre virus is the deer mouse (Peromyscus maniculatus), which is widely distributed in North America. We investigated the prevalence of intramolecular changes and of genomic reassortment among Sin Nombre viruses detected in deer mice in three western states. METHODS: Portions of the Sin Nombre virus small (S) and medium (M) RNA segments were amplified by RT-PCR from kidney, lung, liver and spleen of seropositive peromyscine rodents, principally deer mice, collected in Colorado, New Mexico and Montana from 1995 to 2007. Both a 142 nucleotide (nt) amplicon of the M segment, encoding a portion of the G2 transmembrane glycoprotein, and a 751 nt amplicon of the S segment, encoding part of the nucleocapsid protein, were cloned and sequenced from 19 deer mice and from one brush mouse (P. boylii), S RNA but not M RNA from one deer mouse, and M RNA but not S RNA from another deer mouse. RESULTS: Two of 20 viruses were found to be reassortants. Within virus sequences from different rodents, the average rate of synonymous substitutions among all pair-wise comparisons (pis) was 0.378 in the M segment and 0.312 in the S segment sequences. The replacement substitution rate (pia) was 7.0 x 10-4 in the M segment and 17.3 x 10-4 in the S segment sequences. The low pia relative to pis suggests strong purifying selection and this was confirmed by a Fu and Li analysis. The absolute rate of molecular evolution of the M segment was 6.76 x 10-3 substitutions/site/year. The absolute age of the M segment tree was estimated to be 37 years. In the S segment the rate of molecular evolution was 1.93 x 10-3 substitutions/site/year and the absolute age of the tree was 106 years. Assuming that mice were infected with a single Sin Nombre virus genotype, phylogenetic analyses revealed that 10% (2/20) of viruses were reassortants, similar to the 14% (6/43) found in a previous report. CONCLUSION: Age estimates from both segments suggest that Sin Nombre virus has evolved within the past 37-106 years. The rates of evolutionary changes reported here suggest that Sin Nombre virus M and S segment reassortment occurs frequently in nature.
Asunto(s)
Reservorios de Enfermedades , Evolución Molecular , Síndrome Pulmonar por Hantavirus/veterinaria , ARN Viral/genética , Virus Sin Nombre/clasificación , Virus Sin Nombre/genética , Secuencia de Aminoácidos , Sustitución de Aminoácidos/genética , Estructuras Animales/virología , Animales , Secuencia de Bases , Análisis por Conglomerados , Colorado , Síndrome Pulmonar por Hantavirus/virología , Ratones , Datos de Secuencia Molecular , Montana , New Mexico , Peromyscus , Filogenia , Virus Reordenados/genética , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa/métodos , Análisis de Secuencia de ADN/métodos , Homología de Secuencia , Virus Sin Nombre/aislamiento & purificaciónRESUMEN
el raquitismo dependiente de vitamina D, tipo II (RDVD II), es una enfermedad de herencia autosómica recesiva que se caracteriza por resistencia generalizada a la 1,25- dihidroxivitamina D subíndice 3 originada en alteraciones que comprometen la función del receptor para la vitamina D (RVD). El clonaje y caracterización del cDNA del RVD ha permitido el estudio de su secuencia en pacientes con RDVD II y el hallazgo de diversas mutaciones puntuales que explican el cuadro clínico. En este estudio, hemos utilizado las técnicas de PCR y clonación, para secuenciar el RVD de dos pacientes pertenecientes a un foco descrito previamente en el departamento del Cauca (Colombia), cuyas manifestaciones clínicas y de laboratorio son compatibles con RDVD II. La secuencia del RVD de nuestros pacientes fue normal, sugiriendo una alteración a nivel postranscripcional o postraduccional relacionada con la función del receptor, en lo que podría corresponder a una nueva variante de resistencia a la vitamina D
Asunto(s)
Humanos , Hipofosfatemia Familiar , Raquitismo , Deficiencia de Vitamina D/complicaciones , Análisis de Secuencia de ARNRESUMEN
Foram avaliados 30 pacientes consecutivos com movimentos periódicos do sono, ou miclonias noturnas, diagnosticados por traçado polissonográfico de noite inteira. A média etária foi 50 anos, variando de 30 a 73. Queixa primária de insônia foi vista em 11 casos; sonolência excessiva diurna, em 16 casos; parassonias, em três casos. A média de eficiência do sono foi 83%, sendo que 90% dos pacientes tinham eficiência abaixo de 95%. Estágio 1, durava em média 8,2% do tempo total de sono; estágio 2, 59,8%; estágio 3, 12,3%; estágio 4, 7,1% mas 16 pacientes näo tinham estágio 4, e estágio REM, 16,7%. A latência do estágio Rapid Eye Movement (REM) média, a partir do estágio 2, foi 110,3 m, sendo que 43,3% dos casos tinham este índice abaixo do normal e 23,3% o tinham acima do normal. A densidade REM média foi 11,2%. O número médio de despertares prolongados foi 8,5 e de mudança de estágios foi 49,9. O índice de despertar parcial estava diretamente relacionado à latência REM ao passo que o índice de complexos K estava inversamente relacionado