Modulation of integrin expression in endometrial stromal cells in vitro.

Integrins, a class of cell adhesion molecules found on virtually all cells, display dynamic temporal and spatial patterns of expression in the endometrium during the menstrual cycle and in early pregnancy. To study integrin regulation, we measured the expression of eight different integrin subunits on cultured human endometrial stromal cells obtained from proliferative phase endometrium, using immunofluorescence and flow cytometry. Treatment with estrogen and progesterone induced hormonal changes of decidualization but did not alter the expression of any of the integrins. It is presently unknown whether steroid hormones other than estrogen or progesterone affect integrin expression. In contrast, treatment with several growth factors and cytokines resulted in specific alterations of integrin levels. Epidermal growth factor, transforming growth factor-alpha, and transforming growth factor-beta 1 induced expression of the alpha 1 beta 1 collagen/laminin receptor. There also was a trend towards decreased expression of the alpha 6 subunit in response to interleukin-1 alpha, interleukin-1 beta, and tumor necrosis factor-alpha. The expression of alpha 1 beta 1 was accompanied by increased adhesion to collagen but there was no change in the binding to fibronectin and vitronectin. Our findings suggest that some aspects of decidualization may be regulated by steroid hormones, whereas others, such as integrin expression, are regulated by cytokines or growth factors, possibly of trophoblast origin. Integrins are likely to play a role in the interaction between trophoblast and endometrium.

Unipolar electrosurgery in operative laparoscopy. Capacitance as a potential source of injury.

OBJECTIVE: To determine whether capacitive "stray" currents that can be generated during unipolar laparoscopic electrosurgery are likely to cause unintentional organ injury. STUDY DESIGN: In a controlled laboratory setting, the passage of capacitive current across the insulated portion of unipolar, 5-mm laparoscopic instruments was assessed for its ability to cause damage to biologic tissues. RESULTS: Modulated (coagulating) current output at power settings as low as 20-25 W led to apparent passage of current across the insulated portion of some laparoscopic instruments with thin insulation. This was accompanied by thermal damage to biologic tissues and instrument insulation. CONCLUSION: Our findings can explain unintentional injury during unipolar electrosurgery. The risk of such injury can be reduced by surgeon awareness, low generator output power and use of instruments with ample insulation. Thin insulation is more likely to be encountered with disposable than with multiuse instruments.

Pelvic granulomata mimicking endometriosis following the administration of oil-based contrast media for hysterosalpingography.

BACKGROUND: Hysterosalpingography is used commonly in the evaluation of infertility and in the diagnosis of anomalies of the uterus and fallopian tubes. There is continued debate over the safety and diagnostic or therapeutic efficacy of water-soluble versus oil-based contrast media. CASE: A 29-year-old woman with secondary infertility underwent hysterosalpingography with both water-soluble and oil-based contrast. The fallopian tubes appeared normal. Six months later, a plain abdominal radiograph obtained at the occasion of a minor motor vehicle accident revealed evidence of retained loculated pelvic contrast material. Subsequent laparoscopy identified adhesions and cul-de-sac implants strongly suspicious for endometriosis. Biopsy and pathologic study documented lipogranuloma. CONCLUSION: Oil-based contrast media instilled into the pelvis at hysterosalpingography can persist for prolonged periods and create granulomatous lesions mimicking endometriosis. In view of the controversy whether oil-based contrast materials are superior to water-soluble media, the routine use of oil-based contrast media should be considered carefully.

Laparoscopic capacitance: a mystery measured. Experiments in pigs with confirmation in the engineering laboratory.

OBJECTIVES: Our purpose was to determine whether capacitive currents induced in operative laparoscopes during endoscopic electrosurgery can cause unintentional injury and to measure these currents in the laboratory. STUDY DESIGN: In five anesthetized live pigs we tested whether capacitive currents generated in operative laparoscopes by unipolar instruments cause serosal injury. These currents were then measured in the clinical engineering laboratory. RESULTS: In the setting examined by us serosal injury by capacitive currents occurred only with high generator output power. In the laboratory the maximum power of these capacitive currents measured 2.5 W. CONCLUSIONS: Capacitive coupling between unipolar instruments and 10 mm operating laparoscopes requires relatively high generator output to cause serosal injury. Lower generator output settings may cause injury with electrosurgical generators capable of higher voltages than the units used in this study (Valleylab SSE2L and Force 2).

Endometriosis: the host response.

There is abundant evidence of altered immune function in endometriosis. The task that remains is to attempt a synthesis from the accumulated data, to try to make some sense of the observed phenomena and to fit them into a conceptual framework; this might permit the formulation and testing of hypotheses. Evidently, eutopic endometrium does not engender an immune response in normal subjects, otherwise the endometrium would be subject to autoimmune destruction. It has also been established that the overwhelming majority of women regurgitate menstrual debris into the peritoneal cavity. Why does this lead to endometriosis in some, but not in others? There are several possible explanations. The uterus might act as a privileged site, i.e. be exempt from immune effector mechanisms. This would certainly be conducive to the reproductive goal, the survival of the fetal allograft. Endometrium would then not enjoy the immunologic tolerance of most other tissues, and upon leaving the uterus and entering an immunocompetent environment would be subject to immune attack. In normal subjects, this could consist of elimination of menstrual debris without further sequelae. An altered response, characterized by the production of antibody that could mask receptors for cytotoxic or phagocytic effector cells, would permit persistence of ectopic endometrium. The alternative to this hypothesis is that the uterus is not a privileged site, and that the organism is normally tolerant to endometrial antigens. Menstrual debris would be eliminated intraperitoneally without loss of tolerance due to the presence of homeostatic mechanisms including suppressor T cells and suppressive cytokines. In endometriosis, this tolerance breaks down, as is the case in several autoimmune disorders, causing a chronic inflammatory response with the release of toxic factors and, eventually, peritoneal scarring. Finally, the role of cell adhesion molecules, including the integrins, is only just being explored. The behaviour of these molecules in ectopic endometrium differs from that in eutopic endometrium, and it remains to be seen whether regurgitated endometrial debris from normal subjects is different from that of endometriosis sufferers. It seems that this will be an area of intense investigation in the immediate future.

hCG, progesterone, alpha-fetoprotein, and estradiol in the identification of ectopic pregnancy.

OBJECTIVE: To enhance the laboratory diagnosis of ectopic pregnancy by determining levels of hCG, progesterone, estradiol (E2), and alpha-fetoprotein (AFP). METHODS: Serum samples and medical records were retrospectively analyzed from 100 gynecologic patients for whom quantitative hCG determination had been ordered. Clinical data and levels of hCG, progesterone, E2, and AFP were examined by univariate and multivariate logistic analyses. RESULTS: Progesterone, hCG, and E2 were highest in viable pregnancies, whereas AFP tended to be higher in ectopic pregnancies. A single progesterone value could differentiate between ectopic and viable pregnancy in more than 80% of patients. The combination of all four biochemical markers predicted ectopic pregnancy with 98.5% specificity and 94.5% accuracy. Clinical diagnosis was less than 75% accurate. CONCLUSION: A combination of biochemical markers including hCG, progesterone, E2, and AFP can be superior to a single progesterone level or clinical evaluation in the diagnosis of ectopic pregnancy.

Genetic relationships among Mycobacterium leprae, Mycobacterium tuberculosis, and candidate leprosy vaccine strains determined by DNA hybridization: identification of an M. leprae-specific repetitive sequence.

Comparative DNA hybridization studies of genomic DNA indicated that, while different isolates of armadillo-derived Mycobacterium leprae have a high degree of homology, binding of M. leprae genomic DNA to DNA of other species of mycobacteria or to corynebacteria was low, establishing that M. leprae is only remotely genetically related to any of the species examined. Several candidate leprosy vaccine mycobacterial strains were similarly found to have little genetic similarity to M. leprae. In contrast, the DNAs of the slow-growing mycobacteria M. tuberculosis, M. africanum, M. bovis, and M. microti were found to be very closely related. In the course of these studies, an M. leprae-specific repetitive sequence, greater than 15-fold per genome equivalent, was identified that might be useful for diagnostic and epidemiological studies.

Genes for immunodominant protein antigens are highly homologous in Mycobacterium tuberculosis, Mycobacterium africanum, and the vaccine strain Mycobacterium bovis BCG.

The relatedness of immunodominant protein antigens in Mycobacterium tuberculosis, M. africanum, and M. bovis BCG was investigated by comparing the genes that encode major protein antigens in M. tuberculosis with their counterparts in the other two mycobacteria. Genes encoding homologs of M. tuberculosis major protein antigens were isolated from M. africanum and M. bovis BCG by constructing lambda gt11 recombinant DNA expression libraries and screening them with murine monoclonal antibodies and DNA probes. The antibodies were directed against four major protein antigens of M. tuberculosis with molecular masses of 71, 65, 19, and 14 kilodaltons. The isolated M. africanum and M. bovis BCG DNA clones were mapped with restriction endonucleases, and the maps of the mycobacterial genes were confirmed by Southern analysis of mycobacterial genomic DNA. The restriction maps of DNA containing the four genes in M. tuberculosis, M. africanum, and M. bovis BCG are identical, indicating that the immunodominant proteins that they encode are highly homologous in the three mycobacteria. Thus, the immunity against tuberculosis engendered by M. bovis BCG vaccination could be provided, at least in part, by the immune response to these homologous antigens.

Dissection of Mycobacterium tuberculosis antigens using recombinant DNA.

A recombinant DNA strategy has been used systematically to survey the Mycobacterium tuberculosis genome for sequences that encode specific antigens detected by monoclonal antibodies. M. tuberculosis genomic DNA fragments with randomly generated endpoints were used to construct a large lambda gt11 recombinant DNA expression library. Sufficient numbers of recombinants were produced to contain inserts whose endpoints occur at nearly every base pair in the pathogen genome. Protein antigens specified by linear segments of pathogen DNA and produced by the recombinant phage of Escherichia coli were screened with monoclonal antibody probes. This approach was coupled with an improved detection method for gene isolation using antibodies to clonally isolate DNA sequences that specify polypeptide components of M. tuberculosis. The methodology described here, which is applicable to other pathogens, offers possibilities for the development of more sensitive and specific immunodiagnostic and seroepidemiological tests for tuberculosis and, ultimately, for the development of more effective vaccines.

Macrophage activation in murine African trypanosomiasis.

African trypanosomiasis is accompanied by a profound general immunosuppression in which both suppressive T cells and macrophages (M phi) have been implicated. The present studies define changes in the M phi surface, endocytic and secretory properties, during the infection of mice by Trypanosoma brucei. Peritoneal M phi obtained after the control of the first wave of parasitemia displayed characteristics similar to those activated by intracellular pathogens, such as Mycobacterium bovis bacillus Calmette-Guérin, e.g., the enhanced expression of Ia antigen, decreased M phi-specific antigens, receptors mediating the pinocytosis of mannose-terminal glycoproteins, and an increased ability to secrete plasminogen activator, superoxide anion, and H2O2. Some markers of macrophage activation persisted during the subpatent period before the recurrence of parasitemia, whereas others reverted to normal. Mature T cell function appears not to be essential for M phi activation by T. brucei since the infection of athymic nude mice also induced Ia antigens and plasminogen activator. These studies show that M phi activated by different pathways express common features which may contribute to immune dysfunction observed in trypanosomiasis, as well as in other infections.

Macrophages as primary target cells and mediators of immune dysfunction in African trypanosomiasis.

African trypanosomiasis is accompanied by profound general immunosuppression. The experiments described here were designed to characterize the contribution of macrophages to the immune pathology of this disease. We used peptone-stimulated, uninfected mice and injected them intraperitoneally with lethally irradiated and 35S-labeled Trypanosoma brucei and parasite-specific antisera. Peritoneal macrophages were thus induced to take up in vivo a defined number of trypanosomes. After the phagocytosis of parasites, macrophages were transferred into uninfected syngeneic mice, where they mimicked some of the important immunological changes normally associated with active trypanosome infection: (i) splenic background plaque-forming cells increased nonspecifically and (ii) the specific immune response to sheep erythrocytes was either enhanced or suppressed, depending on the timing of the antigen challenge: priming simultaneously with the transfer of trypanosome-containing macrophages enhanced immune responsiveness; in contrast, if parasite-containing macrophages were transferred and recipient mice were primed 4 days later, the immune response was suppressed. A contribution of suppressor T cells was ruled out by the treatment of peritoneal exudate cells with anti-Thy 1.2 and complement before transfer into recipient mice. The results indicate that macrophages are key cells in the mediation of parasite-induced immune dysfunction.