1/8. Reverse transcriptase and protease sequence evolution in two hiv-1-infected couples.We analyzed the reverse transcriptase (RT) and protease sequences of hiv-1 isolates obtained over 7 years from two couples with known transmission histories. Phylogenetic trees constructed from the sequence data reflected the known transmission histories, despite the fact that the drug resistance mutations were most consistent with the drug treatment histories. However, the RT sequences from one couple diverged by 2.9% even before therapy was begun, and three (0.9%) of 339 unrelated individuals had viruses that shared a common ancestor with sequences from the recipient member of the couple but not with sequences from the transmitter. The divergence between the first two isolates from this couple is consistent with a pretransmission interval during which the transmitter developed a heterogeneous virus population. The closeness between the three controls and the recipient's first RT sequence may indicate slower evolution on the branches of the control sequences. Although the RT and protease genes contain phylogenetic information, they are suboptimal for reconstructing transmission history because the genetic distance between RT and protease isolates from unrelated individuals may occasionally approximate the distance between RT and protease isolates from related individuals.- - - - - - - - - - ranking = 1keywords = tree (Clic here for more details about this article) |
2/8. Adenovirus ascending cholangiohepatitis.Three children, two with liver transplants and one with acquired human immunodeficiency virus (HIV) infection, presented with hepatitis accompanied by elevated gamma glutamyl transpeptidase. Biopsies revealed cholangiohepatitis caused by adenovirus infection. There was a progressive loss of interlobular bile ducts in two of the patients. In one patient, infection of the biliary tree was marked by a necrotizing cholangitis, with adenoviral inclusions noted in the biliary epithelium. In each patient, there was evidence of adenovirus gastrointestinal infection. This is the first report of adenoviral infection of the biliary tree in humans. It is hypothesized that adenovirus cholangiohepatitis occurs as a result of ascending infection from the gastrointestinal tract to the biliary tree.- - - - - - - - - - ranking = 3keywords = tree (Clic here for more details about this article) |
3/8. Cosmopolitan HTLV-Ia subtype among Spanish native patients.HTLV-I isolates exhibit peculiar geographic distributions, but are believed not to be associated with different pathogenic outcomes of these retroviral infections. We have analyzed two HTLV-I-infected Spanish native patients: one patient with a T-cell lymphoma had not travelled to HTLV endemic areas, and the other patient had a paraparesis and had travelled to many HTLV endemic areas such as south america, and Central and south africa. LTR proviral sequences of these isolates were amplified and sequenced to generate phylogenetic trees with different reported HTLV-I strains in order to subtype them. Spanish isolates clustered into the cosmopolitan HTLV-Ia subtype. It is important to know which HTLV-I subtypes are circulating in spain. It is possible that a subtype other than the cosmopolitan one is present in spain, especially African subtypes due to the proximity of this continent and the rise of immigration from Central and South African countries.- - - - - - - - - - ranking = 1keywords = tree (Clic here for more details about this article) |
4/8. Molecular investigation of two possible cases of accidental hiv-1 transmission in south africa.hiv-1 sequences from two possible transmission cases in south africa were examined for evidence of genetic linkage. hiv-1-seropositive blood samples were obtained from a donor and recipient within 8 months following a blood transfusion and from a healthcare worker and her patient within 10 months following a needle-stick injury. A 700-bp region in env and 550-bp region in gag were analyzed. All sequences were phylogenetically associated with hiv-1 subtype C, the predominant hiv-1 subtype in south africa. The nucleotide sequences from the blood transfusion case grouped together significantly with a bootstrap value of 100%. These samples were 98% and 100% identical in the predicted amino acid sequences of env and gag, respectively. In contrast, sequences from the needle-stick case showed only 67% and 80% amino acid identity in env and gag, respectively, and were separated on a phylogenetic tree. Molecular analysis suggested that HIV transmission occurred in the blood transfusion case but not in the case of the needle-stick injury. These data emphasize the need for molecular investigation of epidemiologically linked cases of HIV transmission.- - - - - - - - - - ranking = 1keywords = tree (Clic here for more details about this article) |
5/8. Epidemiological and molecular evidence of two events of father-to-child HIV type 1 horizontal transmission.hiv-1 infection in children less than 15 years of age is mainly due to mother-to-child transmission. The aim of this work was to investigate molecular evidence to prove father-to-be horizontal transmission in two possible events of transmission. In the first event a boy was identified as HIV infected at 2-3 years of age. At the same time infection was confirmed in the father, while mother and siblings were negative. In the second event a girl was negative for HIV at age 1 and identified as hiv-1 infected at age 6. The father's HIV infection was diagnosed in the same period while the mother was repeatedly negative. No evidence of sexual assault or transfusion was recorded in any case. Peripheral blood mononuclear cells were obtained from both fathers and children. After PCR amplification, the C2V3 region of the envelope gene and the region coding for amino acid 132 of p24 up to amino acid 40 of p7 of the gag gene were sequenced. Genetic distance measurements and phylogenetic tree analysis showed that in both cases the father's and child's viral sequences were closely related. They were distinct when compared to argentina sequences including sequences from the same geographic region. Epidemiological and molecular data strongly suggest that horizontal transmission had occurred, probably related to the close father-to-child contact.- - - - - - - - - - ranking = 1keywords = tree (Clic here for more details about this article) |
6/8. Molecular investigation of human immunodeficiency virus type 2 subtype a cases in South korea.We investigated the molecular characteristics of human immunodeficiency virus type 2 (hiv-2) subtype A isolates to clarify the transmission mode of hiv-2 within korea. These findings indicated that the viruses from the six patients infected within korea formed a distinct subcluster in the phylogenetic tree and might have been transmitted from one source.- - - - - - - - - - ranking = 1keywords = tree (Clic here for more details about this article) |
7/8. Baboon-to-human liver transplantation.Our ability to control both the cellular and humoral components of xenograft rejection in laboratory experiments, together with an organ shortage that has placed limits on clinical transplantation services, prompted us to undertake a liver transplantation from a baboon to a 35-year-old man with B virus-associated chronic active hepatitis and human immunodeficiency virus infection. Liver replacement was performed according to conventional surgical techniques. immunosuppression was with the FK 506-prednisone-prostaglandin regimen used routinely for hepatic allotransplantation, to which a daily non-myelotoxic dose of cyclophosphamide was added. During 70 days of survival, there was little evidence of hepatic rejection by biochemical monitoring or histopathological examination. Products of hepatic synthesis, including clotting factors, became those of the baboon liver with no obvious adverse effects. Death followed a cerebral and subarachnoid haemorrhage that was caused by an angioinvasive aspergillus infection. However, the underlying cause of death was widespread biliary sludge that formed in the biliary tree despite a seemingly satisfactory choledochojejunostomy. During life and in necropsy samples, there was evidence of the chimerism that we believe is integral to the acceptance of both xenografts and allografts. Our experience has shown the feasibility of controlling the rejection of the baboon liver xenograft in a human recipient. The biliary stasis that was the beginning of lethal infectious complications may be correctable by modifications of surgical technique. In further trials, the error of over-immunosuppression should be avoidable.- - - - - - - - - - ranking = 1keywords = tree (Clic here for more details about this article) |
8/8. platelet-derived growth factor expression in primary pulmonary hypertension: comparison of HIV seropositive and HIV seronegative patients.Primary pulmonary hypertension (PPH) is characterized by intimal fibrosis and cell proliferation (including fibroblasts, smooth muscle and endothelial cells) in the distal pulmonary arterial tree. Considerable interest has been generated by recent reports of PPH in human immunodeficiency virus (HIV)-1-infected individuals. Although the lack of evidence for a pulmonary artery infection has suggested that in such cases HIV may act through mediator release rather than by direct endothelial infection, the mechanisms underlying HIV-associated PPH remain poorly defined. platelet-derived growth factor (PDGF) has the ability to induce smooth muscle cell and fibroblast proliferation and migration. Given these considerations, we have attempted to document a possible role for PDGF in PPH occurring in HIV seropositive and seronegative patients. Using semiquantitative polymerase chain reaction (PCR), PDGF A-chain messenger ribonucleic acid (mRNA) expression was analysed in surgical lung biopsies from 13 HIV seronegative patients and one HIV seropositive patient, all displaying severe PPH. In parallel, lung samples from two patients with hiv-1-associated PPH were studied by immunohistochemistry and in situ hybridization. Results were compared to those obtained in three hiv-1-infected individuals with no pulmonary complication (as demonstrated by clinical, radiological, bacteriological, and necropsy findings) and five control lung biopsies. As compared to controls, PDGF A-chain mRNA expression is elevated in lung biopsies from patients displaying PPH (p=0.029). In hiv-1-associated PPH, interstitial perivascular cells expressing PDGF A-chain mRNA and protein could be detected by in situ hybridization and immunohistochemistry, respectively. platelet-derived growth factor expression is elevated in lung biopsies of patients displaying primary pulmonary hypertension. Growth factors such as platelet-derived growth factor may play a part in the initiation and/or progression of primary pulmonary hypertension.- - - - - - - - - - ranking = 1keywords = tree (Clic here for more details about this article) |