Previous studies have demonstrated that female reproductive hormones influence chlamydial infection both in vivo and in vitro. Due to the reduced availability of human genital tissues for research purposes, an alternative hormone-responsive model system was sought to study chlamydial pathogenesis. Mature female swine eliminated from breeding programs were selected as the animals of choice because of the similarity of a sexually transmitted disease syndrome and sequelae in swine to a disease syndrome and sequelae found in humans, because of the near identity of a natural infectious chlamydial isolate from swine to Chlamydia trachomatis serovar D from humans, and because a pig's epithelial cell physiology and the mean length of its estrous cycle are similar to those in humans. Epithelial cells from the cervix, uterus, and horns of the uterus were isolated, cultivated in vitro in Dulbecco's minimum essential medium-Hanks' F-12 (DMEM-F-12) medium with and without exogenous hormone supplementation, and analyzed for Chlamydia suis S-45 infectivity. The distribution of chlamydial inclusions in swine epithelial cells was uneven and was influenced by the genital tract site and hormone status. This study confirmed that, like primary human endometrial epithelial cells, estrogen-dominant swine epithelial cells are more susceptible to chlamydial infection than are progesterone-dominant cells. Further, the more differentiated luminal epithelial cells were more susceptible to infection than were glandular epithelial cells. Interestingly, chlamydial growth in mature luminal epithelia was morphologically more active than in glandular epithelia, where persistent chlamydial forms predominated. Attempts to reprogram epithelial cell physiology and thereby susceptibility to chlamydial infection by reversestage, exogenous hormonal supplementation were unsuccessful. Freshly isolated primary pig epithelial cells frozen at ؊80°C in DMEM-F-12 medium with 10% dimethyl sulfoxide for several weeks can, after thawing, reform characteristic polarized monolayers in 3 to 5 days. Thus, primary swine genital epithelia cultured ex vivo appear to be an excellent cell model for dissecting the hormonal modulation of several aspects of chlamydial pathogenesis and infection.

In vitro studies of obligate intracellular chlamydia biology and pathogenesis are highly dependent on the use of experimental models and growth conditions that mimic the mucosal architecture and environment these pathogens encounter during natural infections. In this study, the growth of Chlamydia trachomatis genital serovar E was monitored in mouse fibroblast McCoy cells and compared to more relevant host human epithelial endometrium-derived HEC-1B and cervix-derived HeLa cells, seeded and polarized on collagencoated microcarrier beads, using a three-dimensional culture system. Microscopy analysis of these cell lines prior to infection revealed morphological differences reminiscent of their in vivo architecture. Upon infection, early chlamydial inclusion distribution was uniform in McCoy cells but patchy in both epithelial cell lines. Although no difference in chlamydial attachment to or entry into the two genital epithelial cell lines was noted, active bacterial genome replication and transcription, as well as initial transformation of elementary bodies to reticulate bodies, were detected earlier in HEC-1B than in HeLa cells, suggesting a faster growth, which led to higher progeny counts and titers in HEC-1B cells upon completion of the developmental cycle. Chlamydial development in the less relevant McCoy cells was very similar to that in HeLa cells, although higher progeny counts were obtained. In conclusion, this three-dimensional bead culture system represents an improved model for harvesting large quantities of infectious chlamydia progeny from their more natural polarized epithelial host cells.Chlamydia trachomatis serovars D to K are oculogenital pathogens and the leading cause of bacterial sexually transmitted diseases (41). It is estimated there are 3 to 4 million cases of chlamydial sexually transmitted diseases annually in the United States and some 90 million cases per year worldwide (7). Since the majority of infected individuals are essentially asymptomatic and do not seek medical attention, ascending migration can occur and lead to serious complications, such as prostatitis and epididymitis in men and pelvic inflammatory disease, salpingitis, ectopic pregnancy, and infertility in women (12,14).Chlamydiae are obligate intracellular bacteria and, as such, must be internalized into superficial epithelial cells of the genital mucosa in order to initiate the infectious process. Infection begins with attachment of the infectious elementary bodies (EB) form to the apical surface of columnar epithelial cells, followed by entry via various endocytic mechanisms. The EBcontaining endosomes exit the endocytic pathway to avoid fusion with lysosomes and travel on microtubules to the nuclear hof, where they undergo homotypic fusion with one another, and then the EBs transform into metabolically active reticulate bodies (RB). Since RB divide by binary fission and the number of progeny increases, the expanding endocytic vesicle is termed an inclusion. Eventually, RB mature back into infectious EB, and this devel...

No abstract

No abstract

⎯This paper considers the chemical composition and classification of ground water at seven flowing wells and four springs using materials from the 2014 hydrogeochemical sampling and from continuous observations conducted by the Kamchatka Branch of the Geophysical Survey of the Russian Academy of Sciences (KB GS RAS) in 1989-1999. We estimated the saturation of ground water discharges at individual vents with alumosilicate, carbonate, and sulfate secondary minerals, following the behavior of saturation over time. We have found that the ground water undergoes an increase in the saturation with secondary minerals during large earthquakes that produced shaking of intensity I = 5-6 on the MSK-64 scale. Such changes in the saturation of ground water with secondary minerals are less pronounced during the precursory periods before earthquake occurrence. We discuss desirable future developments of the observational system at wells and springs in order to look for new types of hydrogeochemical precursors to earthquakes.

No abstract

The abundance of various chemical elements (including trace, rare-earth, and radioactive) in the carbon dioxide mineral waters of the Choigan complex has been investigated. Three groups of waters are recognized according to the geochemical conditions and chemical composition: groundwaters of regional-jointing zone with oxidizing conditions; CO 2 -enriched groundwaters of regional-jointing zone with oxidizing conditions; and groundwaters of fault zones with reducing conditions. It is shown that water-rock interaction intensified by high temperature and carbon dioxide action is the main process determining the chemical composition of groundwaters.

The Choygan area of southern Siberia, Russia hosts a variety of CO 2-rich thermal mineral and other waters emerging from springs at temperatures between 7 • C and 39 • C. Chemical analyses of the spring waters (n = 33) were carried out to characterise the waters and determine their origin. A continuum of compositions was observed between relatively lower temperature (7 • C) HCO 3-Ca-Na dominated waters with relatively low amount of total dissolved solids (TDS) and high Eh, and higher temperature (39 • C) HCO 3-Na-Ca dominated waters with higher TDS and lower Eh-this reflects largely conservative mixing of these components between near surface low temperature, oxidising groundwaters and higher temperature, more reducing thermal waters derived from a deeper geothermal reservoir. Stable isotopic data are consistent with all the water ultimately being derived from meteoric water that has undergone varying degrees of isotopic fractionation following evaporation. The inferred δ 18 O and δ 2 H isotopic composition of the unfractionationed meteoric waters is lighter than that expected that of mean annual local precipitation, which together with a strong negative correlation between δ 18 O and the elevation of the sampled discharging springs, suggests recharge at higher elevations (1600 m to 3000 m; average 2600 m). Reservoir temperature, calculated using geothermometers and an analysis of saturation indices of plausible reservoir minerals, ranged from 70 • C to 100 • C at an inferred depth of 2 to 3 km. Not all chemical components were found to follow conservative mixing behaviour. In particular, (i) the CO 2 contents of the waters were highly variable, suggesting either varying degrees of degassing and/or near discharge admixture with air, and (ii) SO 4 concentrations in the lower temperature thermal CO 2-rich waters were highly variable, suggesting a role of near surface oxidation processes, for example of pyrite, in modifying the concentration of redox sensitive components. Limited δ 13 C data are consistent with the CO 2 predominately being derived from dissolution of metamorphic/igneous carbonate minerals in the reservoir. Based on geological conditions, isotope and chemical data, a conceptual circulation model of the Choygan hydrothermal system is proposed.