Spontaneous pneumomediastinum treatment.

The authors report 5 cases that presented to the emergency department of the Athens Naval and Veterans Hospital (Athens, Greece) with spontaneous pneumomediastinum. The clinical picture was not diagnostic in most of the cases, with symptoms of acute retrosternal pain and severe dyspnea in just one case. Diagnostic work disclosed the presence of mediastinal air, and after the exclusion of other diagnoses, spontaneous pneumomediastinum was treated conservatively in all cases. In this case series the authors discuss the main aspects of treatment of these patients, the value of antibiotics during the recovery period and the air distribution in the thoracic tissues.

Involvement of the plasminogen activation system in cow endometritis.

The objectives of this study were to investigate the: (a) presence and activity of components of the "plasminogen activators/plasmin" system in dairy cows with or without endometritis; (b) variations in enzyme activity according to the degree of endometritis; and (c) associations between these enzymes and changes in endometrial histology after intrauterine antibiotic treatment. Endometrial biopsies were collected from anestrus (no palpable ovarian structures and milk progesterone <1 ng/ml) Holstein cows, 30-40 days postpartum. On the basis of a vaginoscopic examination, rectal palpation of the cervix and uterus, and endometrial histology, there were 92 cows with endometritis and 20 cows without endometritis. After biopsy collection, each cow was given an intrauterine infusion of 1.5x10(6) IU of procaine penicillin G. In cows with endometritis, genital tract examinations and biopsies were repeated 2 weeks later. Both plasminogen activators (PAs), tissue type (t-PA) and urokinase (u-PA), were immunologically identified in all uterine biopsies. Plasminogen activator activity (PAA) increased, whereas plasminogen activator inhibition (PAI) and plasmin inhibition (PI) decreased in proportion to the degree of inflammation. Two weeks after intrauterine treatment, PAA had decreased significantly in all cows that had reduced severity of endometrial inflammation and had increased significantly in all cows with increased severity of inflammation. The change in the degree of inflammation depended upon plasminogen activator activity; cows with higher PAA were more likely to improve. In conclusion, there was evidence for a role of the plasminogen activation proteolytic system in bovine endometritis.

Paracrine regulation of ovarian cancer by endothelin.

Previous studies have demonstrated that endothelin (ET) isoforms (ET-1, ET-2 and ET-3) can act in an autocrine manner in ovarian cancer while in breast cancer their role has been proposed to be that of a paracrine mitogen. To explore the possibility that endothelin isoforms might function not only as autocrine regulators but also as paracrine mitogens in ovarian cancers, we investigated their effects on the growth of ovarian fibroblasts derived from ovarian carcinomas, the interaction between ovarian carcinoma and fibroblast cells and the location of the isoform expression in primary ovarian tumours. ET-1, ET-2 and ET-3 stimulated the growth of three ovarian fibroblast cell lines at concentrations ranging from 10(-12) M to 10(-7) M. Inhibition of 125I-ET binding by the ETA receptor antagonist BQ123 and the ETB receptor antagonist BQ788 suggested the presence of both types of ET receptors in fibroblast cells. In the absence of ET-1, neither BQ 123 nor BQ 788 inhibited growth. However, both antagonists inhibited ET-1 stimulated growth suggesting the involvement of both receptor types in ET-1 growth regulation. In contrast to carcinoma cells which secrete measurable levels of ET-1, fibroblast cell lines did not secrete detectable protein. Co-culture experiments (using porous membrane insert wells) of fibroblasts with carcinoma cells demonstrated that growth of both populations of cells was increased compared with either grown in isolation. In this system, growth of the fibroblast cell line was partially inhibited by both BQ123 and BQ788, whilst growth of the PE014 carcinoma cell line was inhibited by only BQ123. RT-PCR measurements detected the presence of the ETA receptor subtype in 10/10 primary ovarian cancers but the presence of ETB receptor in only 6/10 cancers. Using specific antibodies, ET-1 was found in 11/15, ET-2 in 5 of 7 and ET-3 in 5/7 primary ovarian cancers predominantly in the epithelial cells but with some stromal expression. These data indicate that the ET isoforms may stimulate growth of the fibroblast population within an ovarian cancer in addition to stimulating the epithelial cells and since the ETs are expressed in the majority of ovarian cancers, this paracrine effect may contribute to the overall growth of the tumour.

Endothelin expression and responsiveness in human ovarian carcinoma cell lines.

To elucidate the potential role of endothelins (ETs) as growth regulators in ovarian carcinoma cells in culture, expression of endothelins and their receptors were measured in two ovarian cancer cell lines (PEO4 and PEO14), together with the effect of the exogenous addition of endothelins on the growth of these cell lines in vitro. RT-PCR analysis of mRNA prepared from PEO4 and PEO14 indicated the presence of ET-1 and ET-3 mRNA. Immunoreactive ET-1-like peptide was found in media from cultures of both PEO4 (1.7 +/- 0.4 fmol/10(6) cells/72 h) and PEO14 (20.2 +/- 6.8 fmol/10(6) cells/72 h) cell lines. Radioligand binding studies using 125I-ET-1 and membrane fractions were consistent with PEO4 cells having two receptor sites of either high affinity (Kd = 0.065 nM, Bmax = 0.047 pmol/mg protein) or lower affinity sites (Kd = 0.49 nM, Bmax = 0.23 pmol/mg protein). Studies using membrane fractions of PEO14 cells indicated that this cell line has only a single lower affinity binding site (Kd = 0.56 nM, Bmax = 0.31 pmol/mg protein). However, RT-PCR analysis indicated the presence of mRNA from both ETA and ETB receptors in PEO4 and PEO14 cell lines. Exogenous addition of ETs to PEO4 and PEO14 cells at concentrations of 10(-10)-10(-7)M resulted in specific dose-dependent increases in cell number for ET-1 (with maximum effects at 10(-10) and 10(-9)M for PEO4 and PEO14, respectively) and ET-2 (maximum effects at 10(-8) and 10(-9)M for PEO4 and PEO14, respectively) but not for ET-3. Experiments on the growth of PEO14 cells using BQ123 (ETA-R) antagonist and "antisense" oligonucleotide against the ETA-R, in the absence of exogenous ETs, suggested that immunoreactive ET-1-like material secreted by PEO14 cells can affect their growth in an autocrine manner. These results would be consistent with ET-1 acting as a possible autocrine growth regulator in human ovarian carcinoma cells.