23 research outputs found
Phylogenomics of Unusual Histone H2A Variants in Bdelloid Rotifers
Rotifers of Class Bdelloidea are remarkable in having evolved for millions of years, apparently without males and meiosis. In addition, they are unusually resistant to desiccation and ionizing radiation and are able to repair hundreds of radiation-induced DNA double-strand breaks per genome with little effect on viability or reproduction. Because specific histone H2A variants are involved in DSB repair and certain meiotic processes in other eukaryotes, we investigated the histone H2A genes and proteins of two bdelloid species. Genomic libraries were built and probed to identify histone H2A genes in Adineta vaga and Philodina roseola, species representing two different bdelloid families. The expressed H2A proteins were visualized on SDS-PAGE gels and identified by tandem mass spectrometry. We find that neither the core histone H2A, present in nearly all other eukaryotes, nor the H2AX variant, a ubiquitous component of the eukaryotic DSB repair machinery, are present in bdelloid rotifers. Instead, they are replaced by unusual histone H2A variants of higher mass. In contrast, a species of rotifer belonging to the facultatively sexual, desiccation- and radiation-intolerant sister class of bdelloid rotifers, the monogononts, contains a canonical core histone H2A and appears to lack the bdelloid H2A variant genes. Applying phylogenetic tools, we demonstrate that the bdelloid-specific H2A variants arose as distinct lineages from canonical H2A separate from those leading to the H2AX and H2AZ variants. The replacement of core H2A and H2AX in bdelloid rotifers by previously uncharacterized H2A variants with extended carboxy-terminal tails is further evidence for evolutionary diversity within this class of histone H2A genes and may represent adaptation to unusual features specific to bdelloid rotifers
Specific T-cell response to a Pneumocystis carinii surface glycoprotein (gp120) after immunization and natural infection
Single and combined humoral and cell-mediated immunotherapy of Pneumocystis carinii pneumonia in immunodeficient scid mice
Mathematical Modeling of Browning Induction Period in Drying Onion as Influenced by Temperature, Equilibrium Relative Humidity, and Inhibitor
Discovery of the First Selective Inhibitor of Excitatory Amino Acid Transporter Subtype 1
Identificação de agentes infecciosos pulmonares em autĂłpsias de pacientes com a sĂndrome da imunodeficiĂȘncia adquirida Identification of infectious agents in the lungs in autopsies of patients with acquired immunodeficiency syndrome
As afecçÔes pulmonares sĂŁo freqĂŒentes em indivĂduos infectados pelo vĂrus da imunodeficiĂȘncia humana. Neste trabalho, procurou-se identificar atravĂ©s de histoquĂmica e imunohistoquĂmica, agentes infecciosos nos pulmĂ”es de indivĂduos portadores da sĂndrome da imunodeficiĂȘncia adquirida (SIDA), autopsiados entre março de 1990 e julho de 2000 na FMTM. Fragmentos de pulmĂŁo de 40 indivĂduos com SIDA autopsiados foram analisados histologicamente. Foram identificados agentes infecciosos em 34 (85%) casos dos 40 analisados, sendo que bactĂ©rias foram encontradas em 22 (55%) casos. Entre os agentes fĂșngicos o Pneumocystis carinii foi encontrado em oito (19,1%) casos; Cryptococcus sp em quatro (9,5%), Histoplasma sp em dois (4,8%) e Candida sp em um (2,4%) caso. Detectou-se tambĂ©m associação entre Pneumocystis carinii, Citomegalovirus e Cryptococcus sp; CMV e Toxoplasma gondii. Em cinco casos, Candida sp, CMV e Pneumocystis carinii estiveram associados a bactĂ©rias. Entre as infecçÔes nĂŁo bacterianas, os fungos foram os agentes infecciosos mais isolados dos pulmĂ”es em autĂłpsias de indivĂduos com SIDA, sendo o Pneumocystis carinii o mais freqĂŒente.<br>Lung diseases are frequently observed in individuals infected with HIV. The aim of this study was to identify infectious agents in the lungs in the autopsied individuals with AIDS performed between march 1990 and july 2000 at the school of medicine (Uberaba- Brazil), using histochemical and immunohistochemical techniques. Analysis was made on lungs obtained from 40 individuals with AIDS. Infectious agents were observed in 34 (85%) cases of the 40 analyzed. Regarding fungis, Pneumocystis carinii was found in 8 (19.1%)cases; Cryptococcus sp in 4 (9.5%)cases, Histoplasma sp in 2 (4.8%)cases and Candida sp in 1 (2.4%)case. Association of Pneumocystis carinii, Citomegalovirus and Cryptococcus sp, was observed in one case, and in another, the association of CMV, and Toxoplasma gondii. There were 5 cases with Candida sp, CMV and Pneumocystis carinii associated with bacteria. In conclusion, this study shows that following bacterial agents fungi were the second most common infectious agents in post mortem examination of the lungs from patients with AIDS, being Pneumocystis carinii the most prevalent