Two novel circo-like viruses detected in human feces: complete genome sequencing and electron microscopy analysis.

The application of viral metagenomic techniques and a series of PCRs in a human fecal sample enabled the detection of two novel circular unisense DNA viral genomes with 92% nucleotide similarity. The viruses were tentatively named circo-like virus-Brazil (CLV-BR) strains hs1 and hs2 and have genome lengths of 2526 and 2533 nucleotides, respectively. Four major open reading frames (ORFs) were identified in each of the genomes, and differences between the two genomes were primarily observed in ORF 2. Only ORF 3 showed significant amino acid similarities to a putative rolling circle replication initiator protein (Rep), although with low identity (36%). Our phylogenetic analysis, based on the Rep protein, demonstrated that the CLV-BRs do not cluster with members of the Circoviridae, Nanoviridae or Geminiviridae families and are more closely related to circo-like genomes previously identified in reclaimed water and feces of a wild rodent and of a bat. The CLV-BRs are members of a putative new family of circular Rep-encoding ssDNA viruses. Electron microscopy revealed icosahedral (~23 nm) structures, likely reflecting the novel viruses, and rod-shaped viral particles (~65-460 × 21 × 10 nm in length, diameter, and axial canal, respectively). Circo-like viruses have been detected in stool samples from humans and other mammals (bats, rodents, chimpanzees and bovines), cerebrospinal fluid and sera from humans, as well as samples from many other sources, e.g., insects, meat and the environment. Further studies are needed to classify all novel circular DNA viruses and elucidate their hosts, pathogenicity and evolutionary history.

α-Tocopherol administration blocks adaptive changes in cell NADH/NAD+ redox state and mitochondrial function leading to inhibition of gastric mucosa cell proliferation in rats.

In experimentally induced chronic gastritis, a compensatory mucosal cell proliferation occurs with enhanced glucose oxidative metabolism linked to lipoperoxidative events. Therefore, this study was aimed at assessing the participation of cell NAD/NADH redox state and mitochondrial functions during gastric mucosa proliferation and the effects of in vivo α-tocopherol (vitamin E) administration. Glucose oxidation and oxygen consumption were tested in gastric mucosa samples obtained from rats with gastritis and from those also treated with α-tocopherol. Gastric mucosal mitochondria were isolated and structural and functional parameters were determined. Succinate oxidation, ADP phosphorylation, mitochondrial enzyme activities, and membrane lipid composition were measured. In addition, parameters indicative of cellular NAD/NADH redox state, proliferation, apoptosis, and nitric oxide (NO) metabolism were also determined. After ethanol withdrawal, the damaged gastric mucosa increased glucose and oxygen consumption, events associated with a more reduced cytoplasmic NAD/NADH ratio. Enhanced mitochondrial oxidative phosphorylation and increased mitochondrial enzyme activities occurred early, accompanied by recovery of lost mitochondrial protein and lipid composition in the gastric mucosa, events associated with increased NO production. When mitochondrial function and structural events were normalized, apoptosis was initiated as assessed by the mitochondrial Bax/Bcl2 ratio. Treatment with α-tocopherol inhibited cell proliferation and blocked enhanced glucose utilization, mitochondrial substrate oxidation, and changes in redox state, delaying the onset of these adaptive metabolic changes, whereas it inhibited cell proliferation. In conclusion, α-tocopherol could abolish damage-induced "stress" signaling by desynchronizing mitochondrial adaptive responses, including mitochondria biogenesis, and consequently NAD/NADH redox, which seems to regulate gastric mucosal cell proliferation.

EFEITOS DO PRÉ-CONDICIONAMENTO HEPÁTICO EM RATOS CIRRÓTICOS, SUBMETIDOS À ISQUEMIA E REPERFUSÃO HEPÁTICA RESULTADOS PRELIMINARES

We studied the influence of ischemic preconditioning in rat liver cirrhosis.The cirrhosis were induced in wistar rat with occlusion of biliary duct before 30 days operation and divided into group A, ischemic preconditioning and ischemic/reperfusion, and group B, only ischemic/reperfusion. In group A the preconditioning consisted of 5 min ischemic and 10 min reperfusion. The ischemic/reperfusion consisted of 20 min ischemic and 120 min reperfusion for both groups. The level of respiratory control reason (RCR) in the liver tissue 120 min after reperfusion was not difference significantly in the groups. Therefore it suggests that the preconditioning cam be viability and another object of studies must be rated in future this work.

Baseando-se nos efeitos estimuladores do metabolismo energético pelo pré-condicionamento isquêmico (PCI) no tecido hepático, estudou-se dois grupos de ratos cirróticos submetidos a isquemia de 20 min e reperfusão de 120 min, após o PCI ou não respectivamente, determinando assim o valor do seu uso no prolongamento da manobra de Pringle e na regeneração hepática na hepatectomia.

Efeitos do pré-condicionamento hepático em ratos cirróticos, submetidos à isquemia e reperfusão hepática resultados preliminares

We studied the influence of ischemic preconditioning in rat liver cirrhosis.The cirrhosis were induced in wistar rat with occlusion of biliary duct before 30 days operation and divided into group A, ischemic preconditioning and ischemic/reperfusion, and group B, only ischemic/reperfusion. In group A the preconditioning consisted of 5 min ischemic and 10 min reperfusion. The ischemic/reperfusion consisted of 20 min ischemic and 120 min reperfusion for both groups. The level of respiratory control reason (RCR) in the liver tissue 120 min after reperfusion was not difference significantly in the groups. Therefore it suggests that the preconditioning cam be viability and another object of studies must be rated in future this work.

Baseando-se nos efeitos estimuladores do metabolismo energético pelo pré-condicionamento isquêmico (PCI) no tecido hepático, estudou-se dois grupos de ratos cirróticos submetidos a isquemia de 20 min e reperfusão de 120 min, após o PCI ou não respectivamente, determinando assim o valor do seu uso no prolongamento da manobra de Pringle e na regeneração hepática na hepatectomia.