Structure and function of intercellular junctions in human cervical and vaginal mucosal epithelia

The mucosal epithelium is a major portal for microbial invasion. Mucosal barrier integrity is maintained by the physical interactions of intercellular junctional molecules on opposing epithelial cells. The epithelial mucosa in the female reproductive tract provides the first line of defense against sexually transmitted pathogenic bacteria and viruses, but little is known concerning the structure and molecular composition of epithelial junctions at this site. In the present study, the distribution of tight, adherens, and desmosomal junctions were imaged in the human endocervix (columnar epithelium) and ectocervix (stratified squamous epithelium) by electron microscopy, and permeability was assessed by tracking the penetration of fluorescent immunoglobulin G (IgG). To further define the molecular structure of the intercellular junctions, select junctional molecules were localized in the endocervical, ectocervical, and vaginal epithelium by fluorescent immunohistology. The columnar epithelial cells of the endocervix were joined by tight junctions that excluded apically applied fluorescent IgG. In contrast, the most apical layers of the ectocervical stratified squamous epithelium did not contain classical cell-cell adhesions and were permeable to IgG. The suprabasal and basal epithelial layers in ectocervical and vaginal tissue contained the most robust adhesions; molecules characteristic of exclusionary junctions were detected three to four cellular layers below the luminal surface and extended to the basement membrane. These data indicate that the uppermost epithelial layers of the ectocervix and vagina constitute a unique microenvironment; their lack of tight junctions and permeability to large-molecular-weight immunological mediators suggest that this region is an important battlefront in host defense against microbial pathogens.     

Altered response of cervical and vaginal epithelia to oestradiol benzoate in ewes after prolonged exposure to oestrogenic pasture.

Ovariectomized ewes, 10 clover disease infertility and 10 controls, were injected daily for 3 days with 25 micrograms oestradiol benzoate. At the end of this period, the Spinnbarkeit of cervical mucus and the keratinization of the vaginal epithelium were less in the infertile ewes. It is suggested that the infertility in clover-affected ewes is due to an inability of target organs to give a continued response to the 'priming' action of oestrogen.     

Models of oral and vaginal candidiasis based on in vitro reconstituted human epithelia

This protocol describes the setup, maintenance and characteristics of models of epithelial Candida infections based on well-established three-dimensional organotypic tissues of human oral and vaginal mucosa. Infection experiments are highly reproducible and can be used for the direct analysis of pathogen-epithelial cell interactions. This allows detailed investigations of Candida albicans wild type or mutant strain interaction with epithelial tissue or the evaluation of the host immune response using histological, biochemical and molecular methods. As such, the models can be utilized as a tool to investigate cellular interactions or protein and gene expression that are not complicated by non-epithelial factors. To study the impact of innate immunity or the antifungal activity of natural and non-natural compounds, the mucosal infection models can be supplemented with immune cells, antimicrobial agents or probiotic bacteria. The model requires at least 3 days to be established and can be maintained thereafter for 2-4 days.     

Use of a vaginal mucus impedance meter to detect estrus in the cow

Two experiments were conducted to investigate the efficacy of a vaginal mucus impedance meter for the detection of estrus in the dairy cow. In Experiment 1 the positioning of the probe within the vaginal tract was examined in dairy cows (n=6) by measuring mucus impedance at 5-cm intervals during probe withdrawal and comparing these fixed distance measurements with the depth within the vaginal tract at which the lowest impedance measurement was recorded. Measurements at 15 and 20 cm from the vulva were significantly lower than at other fixed depths, but did not show a reduction during estrus. The lowest recording upon withdrawal of the probe, which usually occurred between 15 and 20 cm from the vulva, was significantly lower than at any fixed depth recordings and was reduced proportionate during estrus to 0.14 of its non-estrus value. In Experiment 2 the accuracy of the probe to confirm estrus in cows exhibiting possible estrus signs was examined. Dairy cows (n=191) were inseminated either on the basis of herdsman observation of behavior alone (Treatment A) or on the basis of herdsman observation with cows exhibiting signs of estrous behaviour, but not standing to be mounted, being tested for vaginal mucus impedance (Treatment B). There were no significant treatment differences in the estrus detection rate, conception rate or other reproductive performance parameters. However, in 12% of cows in Treatment B, measurement of vaginal mucus impedance detected an extra estrous event, giving a theoretical increase in the estrus detection rate from 0.67 to 0.74 detected/predicted estrous events. It was concluded that when using a vaginal probe the lowest value in the vaginal tract should be sought, but that using the probe as an adjunct to herdsman's observation would not greatly increase estrus detection rate.     

Diethylstilbestrol-induced cervical and vaginal adenosis using the neonatal mouse model

The relevance of diethylstilbestrol (DES) administration to neonatal mice as a model for human pathology attributed to the use of DES in high-risk pregnancies has been investigated, particularly with respect to cervical and vaginal changes in female offspring. Neonatal DES treatment of mice results in tonic pituitary gonadotropin release and continuous estrogen secretion by the ovary. Studies were designed to determine the effect of this altered ovarian endocrine activity on cervical and vaginal histopathology. Ovariectomy of DES-treated mice, with or without estradiol replacement, did not eliminate the lesions, nor did estrogen and progesterone administered in a regimen intended to mimic estrous cycle changes. Induction of the constant estrus state by neonatal estradiol benzoate or testosterone propionate administration or by exposure to constant light did not produce the type of vaginal or cervical changes seen in DES mice. Thus, altered ovarian function is apparently not required for the vaginal and cervical changes appearing in later life. A role for endogenous (or exogenous) ovarian hormones in the developmental progression toward normality is suggested.     

Histomorphology of cervical and uterine epithelia of crab-eating macaque, Macaca fasciularis.

Cytological characteristics and pattern of distribution of different cell types in the epithelia of cervix and uterus of crab-eating macaque (Macaca fascicularis) in follicular and luteal phases of the menstrual cyclic and amenorrhea were studied. The cervix uteri and uterus exhibit remarkable structural differenes in the ciliated, secretory, and ciliated-secretory cells. Since the number of ciliated-sexretory cells in the uterus is higher than in the cervix. It is believed that they form an additional source for the secretion of uterine fluid during the menstrual cylce. Both ciliated and secretory cells undergo degeneration; extensive cytoplasmic vacuolation associated with pycnosis and disorganization of the nuclei encountered.     

The fine structure of exfoliated cervical and vaginal cells.

In order to understand the means by which cellular aggregates were maintained in gynecologic samples, the fine structure of samples derived from a number of women of various ages was examined with special attention paid to the intercellular junctions. Most cells in the samples were squamous cells containing numerous intercellular fibrils and glycogen granules. Parabasal or intermediate cells were also seen as well as occasional endocervical cells. All of these cell types were often found as parts of aggregates and, while other cell junctions were present, desmosomes were the most prominent. It was concluded that desmosomes were probably responsible for maintaining the aggregated state of many of the cells found in gynecologic samples.     

Involvement of Fas in regression of vaginal epithelia after ovariectomy and during an estrous cycle.

Fas, also called APO-1, belongs to the tumor necrosis factor/nerve growth factor receptor family and transmits an apoptotic signal within the cell by binding to the Fas ligand. Fas has been implicated in the activation-induced suicide of T cells and cytotoxic T cell activity in the immune system. Non-immune cells such as those in liver, lung and ovary also express Fas, but its role in these cells remains unclear. Ovariectomy has been used to study homeostasis of female reproductive organs, which is regulated by sex hormones. Here we analyzed Fas function in the ovariectomy-induced regression of mouse vaginal epithelial cells. Fas expression was detected in vagina and was elevated after ovariectomy. Fas-deficient lpr and lpr(cg) mice did not exhibit ovariectomy-induced regression of vaginal epithelia, whereas uterine regression induced by ovariectomy was not affected in these mice. The vaginas of lpr and lpr(cg) mice were in a persistent estrous stage with cornification of vaginal epithelia, as judged from the cell types in the vaginal fluid. Thus, Fas appears to be involved directly in the regression of vaginal epithelia induced by ovariectomy and during the estrous cycle, suggesting that the physiological role of this receptor extends beyond that exerted on immune cells. This is the first evidence of a role for Fas inducing physiological apoptosis in non-immune cells.     

Significance of extensive hyperkeratosis on cervical/vaginal smears

OBJECTIVE: To assess the significance of reporting hyperkeratosis on cervical/vaginal (CV) smears. STUDY DESIGN: Cases diagnosed with extensive hyperkeratosis (E-HK) and without prior or concurrent history of neoplasia, squamous intraepithelial lesion or atypical squamous cells of undetermined significance (ASCUS) were retrieved from our files for the period January 1994-August 2001. E-HK is defined in our practice as patches of anucleated squames with irregular, angulated edges present in at least 5 low-power (10 x eyepiece and 10 x objective) fields on a conventional CV smear. On liquid-based preparations, we use 3 low-power fields. Only cases with a follow-up CV smear and/or cervical biopsy (CB) were selected. RESULTS: Among 328 cases of E-HK, 138 patients met the study selection criteria. Eighty-one cases had negative CV smears and/or CB, 17 (12.3%) patients had persistent E-HK, and a subsequent diagnosis of ASCUS or higher was made in 40 patients (28.9%). Among the 40 cases with subsequent abnormalities, 13 (9.4%) were diagnosed with ASCUS, 24 (17.4%) with HPV or dysplasia, and 3 (2.1%) with malignancy. CONCLUSION: While isolated, anucleate squames may have no clinical importance in patient management, E-HK can be a significant marker of underlying neoplastic disease. This should be kept in mind as one decides how to report CV cytology based on 2001 Bethesda System recommendations.     

Studies of cell lipids from the human vaginal and cervical epithelium during the menstrual cycle

The cholesterol fractions of lipids from vaginal washings of 18 women in the estrogenic phase (4 pools, 10 mg each), 16 in the progesteronic phase (4 pools, 10 mg each), and 20 exhibiting atrophy (3 pools, 10 mg each, separated by column chromatography, assayed by colorimetry, were .711 plus or minus .022, 1.227 plus or minus .023, and 1.245 plus or minus .026 mg/10 mg of total lipids, respectively. Cholesterol ester fractions (not identified by thin layer chromatography), similarly assayed, were .327 plus or minus .007, .281 plus or minus .007, and .282 plus or minus .004 mg/10 mg lipids, respectively. Phospholipid fractions, determined by assaying an inorganic phosphorous compound formed from the organic phosphorous, were .494 plus or minus .160, 1.294 plus or minus .596, and 3.204 plus or minus .035 mg/10 mg lipids, respectively. Triglyceride fractions, determined by assaying glycerol yielded by saponification, were 6.222 plus or minus .019, and 4.818 plus or minus .029, and 2.893 plus or minus .010 mg/10 mg lipids, respectively. Unidentified fractions were 2.246, 2.380, and 2.376 mg/10 mg total lipids. The increased amount of choleterol ester and decreased amount of cholesterol in the estrogenic phase is analogois to increased esterification of free cholesterol in keratinization of squamous cells. The phospholipid content, greatest in cells, in atrophy, and least in cells in the estrogenic phase, varies analogously to the decrease of mitochondria of basal squamoius epithelial cells as they move to higher strata. Fat is deposited during differentiation of the vaginal epitheliuml thus triglycerida content increases.     

Mucopolysaccharides Isolated from Human and Cow Colostrums

Mucopolysaccharides were isolated from both human and cow colostrums. Each of the fractionated mucopolysaccharides was considered to be homogeneous from behaviors in chromatography, electrophoresis and sedimentation pattern. The fractions isolated from human colostrum were found to contain 51.0~78.3% carbohydrates consisting of d-galactose, 2-amino-2-deoxy-d-glucose, N-acetylneuraminic acid, l-fucose and d-glucose, and 31.6~11.0% peptides consisting of 16 kinds of amino acids. The sedimentation constants, s_{20, w}, of these fractions were in the range of 0.75 to 1.73 S. The fraction isolated from cow colostrum was found to contain 19.3% carbohydrates consisting of d-galactose, 2-amino-2-deoxy-d-glucose and N-acetylneuraminic acid, and 65.2% peptides or proteins consisting of 18 kinds of amino acids. The sedimentation constant, s_{20, w}, of the fraction was 3.68 S.