Differential expression of placental villous angiopoietin-1 and -2 during early, mid and late baboon pregnancy.

Although vascular endothelial growth factor (VEGF), angiopoietin-1 (Ang-1) and Ang-2 have important roles in angiogenesis, very little is known about the regulation of these factors in the villous placenta during human pregnancy. In the present study, to investigate whether placental expression of Ang-1, Ang-2 and VEGF was altered in a cell-specific manner with advancing baboon gestation, the mRNA levels of these growth factors were determined by RT-PCR in cells isolated by Percoll gradient centrifugation from and protein localization assessed by immunocytochemistry in the villous placenta at early (day 60), mid (day 100) and late (day 170, term is 184 days) baboon gestation. Mean (+/-SE) Ang-1 mRNA levels, relative to 18S rRNA, in villous syncytiotrophoblast (3.92+/-0.68) and cytotrophoblast (1.31+/-0.31) cell fractions were highest on day 60 of gestation, then decreased by approximately 2.5-fold (P<0.05) to 1.39+/-0.29 and 0.49+/-0.07, respectively, on day 170. Moreover, Ang-1 mRNA levels in the villous stromal cells and Ang-2 mRNA levels in all placental villous cell fractions were similar on days 60, 100, and 170 of gestation. In contrast to Ang-1 and Ang-2, placental villous cytotrophoblast VEGF mRNA levels were increased 2.94-fold (P<0.05) between mid (0.67+/-0.15) and late (1.97+/-0.49) gestation. A corresponding decrease in Ang-1, absence of change in Ang-2, and increase in VEGF protein immunocytochemical expression were exhibited in placental trophoblast with advancing baboon pregnancy. Ang-1/Ang-2 and the angiopoietin Tie-2 receptor were expressed in vascular endothelial cells of the villous placenta, indicating that these blood vessel cells are a major site of ligand-receptor interaction for angiogenesis during primate pregnancy. We conclude that there is a cell-specific differential change in placental villous trophoblast expression of VEGF, Ang-1, and Ang-2 which we propose is important in regulating angiogenesis in the villous placenta during primate pregnancy.

HIV-associated myocarditis. Pathology and immunopathology.

Autopsy studies of AIDS (acquired immune deficiency syndrome) patients showed a high incidence of myocarditis. To attain a better understanding of the pathogenesis, the pathology and immunopathology of nine endomyocardial biopsies with active myocarditis from 18 human immunodeficiency virus (HIV)-positive patients were systematically characterized. These were compared with 17 biopsies with active myocarditis from patients without AIDS risk factors. In both groups, the myocarditis consisted of either multifocal or interstitial infiltrates of small lymphocytes and isolated myocyte necrosis. The lymphocytes consisted of T cells (CD2+, CD3+) and cells not identified by the usual markers. B cells, monocytes, CD4+ cells, and natural killer (NK) cells were only rarely observed. All of the HIV-positive patients but only 7 of 17 non-HIV patients had CD8+ lymphocytes in the infiltrates (P less than 0.01). The arteriolar endothelium demonstrated induced class I (HLA-A, B, C) and II (HLA-DR) antigens in both groups. In situ hybridization for HIV-1 failed to identify the virus in the specimens. The immunopathology is consistent with a cell-mediated injury to the myocytes in HIV-positive patients and is similar to a subgroup of myocarditis in the non-HIV group.

Cytomegalovirus but not human T lymphotropic virus type III/lymphadenopathy associated virus detected by in situ hybridisation in retinal lesions in patients with the acquired immune deficiency syndrome.

Paraffin sections of retinal tissue from five patients who died from the acquired immune deficiency syndrome (AIDS) and retinopathy were examined by in situ hybridisation experiments with deoxyribonucleic acid (DNA) labelled with sulphur-35 of lentivirus, human T lymphotropic virus type III/lymphadenopathy associated virus (HTLV-III/LAV), and cytomegalovirus. HTLV-III/LAV ribonucleic acid (RNA) was not detected in any of the tissue sections. Cytomegalovirus RNA was identified, however, in three of the five patients. Retinopathy induced by cytomegalovirus may thus be one of the many syndromes potentiated by the immunosuppression caused by HTLV-III/LAV.