Kinetics of cell replication in the uterine cervix. VI. Loci of DNA-synthesizing cells and arrested mitoses in the basal-cell layer

The mode of proliferation in the basal-cell layer of the squamous cervical epithelium was investigated in C57B1 mice with the aid of 3H-thymidine and vincristine. Six hours after vincristine injection and two hours after thymidine injection, 33% of the basal cells were in DNA synthesis and 12% in mitosis. Of these, only 23% of the cells in DNA synthesis and 45% of those in mitosis were found as single cells. The remaining cells proliferated in clusters of two or more cells. As many as 59% of the cells in DNA synthesis and 30% of those in mitosis occurred in colonies of three or more consecutive cells, indicating that multicell clustering is a rather common pattern of basal cell proliferation. Multicell loci of DNA-synthesizing cells occurred contemporaneously with but independently of multicell loci of mitotic cells (the loci were nonconsecutive). Basal-cell replication in the squamous cervical epithelium thus appears to be an organized process of cell renewal.     

Microglandular hyperplasia of the uterine cervix. Cytologic diagnosis in cervical smears

OBJECTIVE: To identify cytomorphologic features specific to microglandular hyperplasia (MGH) in cervical cytologic smears. STUDY DESIGN: Twenty-four cervical smears from 24 patients obtained before the histologic diagnosis of MGH made on colposcopically directed biopsies during a period of two years (1995-1997) were evaluated. RESULTS: Of cases with MGH, 13/24 (54%) showed the presence of bidimensional or tridimensional cellular clusters made up of cubic or cylindrical glandular cells with vacuolated cytoplasm; cells with dense cytoplasm, basaloid in appearance, corresponding to immature squamous metaplasia; and subcylindrical reserve cells with small, round nuclei and scant cytoplasm. Clusters showed microlumina or fenestrated spaces, preserved polarity and absence of nuclear peripheral dispersion. In the control group these cellular clusters were found in 6/100 (6%). Statistical analysis (chi 2) showed a strong, highly significant association (P < 0.001) of the cytologic parameters selected and the histologic diagnosis of MGH. CONCLUSION: Until now, no specific cytologic parameters were described for MGH. This study underscored the value of cytomorphologic parameters described for typical cellular clusters showing microlumina or fenestrated spaces with shared party walls and an admixture of glandular cells, and immature squamous metaplastic and subcylindrical reserve cells in the cytologic diagnosis of MGH.     

Arabidopsis replication factor C4 is critical for DNA replication during the mitotic cell cycle

Replication factor C (RFC) is a conserved eukaryotic complex consisting of RFC1/2/3/4/5. It plays important roles in DNA replication and the cell cycle in yeast and fruit fly. However, it is not very clear how RFC subunits function in higher plants, except for the Arabidopsis (At) subunits AtRFC1 and AtRFC3. In this study, we investigated the functions of AtRFC4 and found that loss of function of AtRFC4 led to an early sporophyte lethality that initiated as early as the elongated zygote stage, all defective embryos arrested at the two‐ to four‐cell embryo proper stage, and the endosperm possessed six to eight free nuclei. Complementation of rfc4‐1/+ with AtRFC4 expression driven through the embryo‐specific DD45pro and ABI3pro or the endosperm‐specific FIS2pro could not completely restore the defective embryo or endosperm, whereas a combination of these three promoters in rfc4‐1/+ enabled the aborted ovules to develop into viable seeds. This suggests that AtRFC4 functions simultaneously in endosperm and embryo and that the proliferation of endosperm is critical for embryo maturation. Assays of DNA content in rfc4‐1/+ verified that DNA replication was disrupted in endosperm and embryo, resulting in blocked mitosis. Moreover, we observed a decreased proportion of late S‐phase and M‐phase cells in the rfc4‐1/–^{FIS2;DD45;ABI3pro::AtRFC4} seedlings, suggesting that incomplete DNA replication triggered cell cycle arrest in cells of the root apical meristem. Therefore, we conclude that AtRFC4 is a crucial gene for DNA replication.     

Adenoid basal lesions of the uterine cervix: evolving terminology and clinicopathological concepts

The epithelial proliferations that are designated adenoid basal carcinoma (ABC) in the current classification from the World Health Organization represent <1% of all cervical malignancies. These lesions may be associated, and occasionally show morphologic transitions with, conventional cervical malignancies. The determination of the precise frequency with which these so-called ABCs show this association is hampered by the inherent selection bias in the reported cases. However, this frequency appears to be substantial (>15%). The biologic course of ABCs that are associated with separate malignancies is largely dependent on the clinicopathologic parameters of the associated malignancies. Morphologically pure lesions, in contrast, have largely been associated with favorable patient outcomes, as none of the 66 reported patients have experienced tumor recurrence, metastases or tumor-associated death, irrespective of the modality of treatment. Although the finding of genome integrated high-risk human papillomavirus (HPV) types and p53 alterations in adenoid basal lesions (ABL) argue in support of their neoplastic nature, we identified no lines evidence that suggest an inherent malignancy for morphologically pure lesions. The finding of morphologic transitions between ABLs and conventional malignancies and shared HPV types in these areas, suggest that ABLs have some malignant potential. However, the precise magnitude of this potential is not readily quantifiable and should not dictate the management of morphologically pure lesions that are entirely evaluable. ABLs continue to occupy a unique position in human oncology in which the term carcinoma (without an in-situ suffix) is applied to a tumor that has not been shown to recur, metastasize or cause death. We concur with a previous proposal that the term ABC should be discarded and replaced with Adenoid Basal Epithelioma (ABE). In our opinion, there is insufficient evidence at present time to expose patients with morphologically pure lesions to the ominous implications – social, psychological, medical, financial – of a "carcinoma" diagnosis. Morphologically impure lesions should not be designated ABC or ABE. Furthermore, given the uncertainties regarding the frequency with which ABE are associated with separate malignancies, we suggest that the ABE designation only be applied when the tumor in question is entirely evaluable e.g in a hysterectomy specimen or in an excisional biopsy with negative margins. Otherwise, the generic designation Adenoid Basal Tumor is preferable. This approach strikes an appropriate balance between the need to prevent over-treatment of pure lesions on one hand, and the need to ensure that the lesions are indeed pure on the other.     

Enhanced expression of Mcm proteins in cancer cells derived from uterine cervix.

Minichromosome maintenance proteins (Mcm) 2-7 play essential roles in eukaryotic DNA replication. Several reports have indicated the usefulness of Mcm proteins as markers of cancer cells in histopathological diagnosis. However, their mode of expression and pathophysiological significance in cancer cells remain to be clarified. We compared the level of expression of Mcm proteins among human HeLa uterine cervical carcinoma cells, SV40-transformed human fibroblast GM00637 cells and normal human fibroblast WI-38 cells. All the proteins examined were detected in HeLa and GM cells at 6-10 times the level found in WI-38 cells on average. This increase was observed both in total cellular proteins and in the chromatin-bound fraction. Consistently, Mcm2 mRNA was enriched in HeLa cells to approximately four times the level in WI-38 cells, and the synthesis of Mcm4, 6 and 7 proteins was accelerated in HeLa cells. Immunohistochemical studies of surgical materials from human uterine cervix showed that Mcm3 and 4 are ubiquitously expressed in cancer cells. Further, the positive rate and level of Mcm3 and 4 expression appeared to be higher in cancer cells than in normal proliferating cells of the uterine cervix and dysplastic cells, suggesting that they can be useful markers to distinguish these cells.     

Disruption of DNA replication in non-irradiated cells in basal cell nevus syndrome and the effect of ionizing radiation

Analysis of DNA fiber autoradiograms from basal cell nevus syndrome (BCNS) skin fibroblasts has revealed for the first time a new defect in DNA replication earlier unknown in other chromosomal instability syndromes, that involves a significantly decreased rate of DNA-chain growth in unirradiated cells. Here we present evidence that the defect may be due to a marked reduction in number of simultaneously operating groups of replicons compared to that in normal cells, the rate of fork movement and the fusion of neighbouring units in the group remaining unchanged. Radioresistant DNA synthesis was observed in the BCNS cells. The exposure of cells derived from normal donor to gamma-rays at a dose of 5 Gy reduces the number of simultaneously operating groups of replicons to the level occurring in unirradiated BCNS cells, the rate of folk movement being unchanged in both cell types. However, the incidence of fusion between neighbouring units within the group is lower in the cells exposed to gamma-rays, due perhaps to a radiation-induced lesion in the group. Thus, ionizing radiation reduces the rate of DNA synthesis to the same level, however from different initial levels. Our data suggest that the phenomenon of radioresistant DNA synthesis may be explained by the presence of the initial defect in DNA replication in BCNS or any other chromosomal instability disorders.     

Acantholytic cells exfoliated from pemphigus vulgaris of the uterine cervix. A case report

BACKGROUND: Pemphigus vulgaris of the uterine cervix is rare and almost always associated with cutaneous or mucosal lesions elsewhere on the body. Without a history of pemphigus, acantholytic cells in cervical smears may be misdiagnosed as malignant ones. CASE: A 52-year-old female presented with a vaginal discharge, and a routine cervical smear was collected for cytology. The smear displayed atypical cells lying singly and in loose clusters, having vesicular nuclei, a thin nuclear membrane, prominent nucleoli and well-defined cytoplasmic margins. These were labeled atypical glandular cells of undetermined significance, and colposcopic examination and biopsy were advised. On colposcopy vesicular lesions and erosions were noticed on the cervix. The biopsy revealed typical intact as well as denuded suprabasal bullae of pemphigus vulgaris. On reevaluation of the cytologic smear, the cytomorphologic features correlated well with the acantholytic cells of pemphigus. Thorough reexamination of the patient revealed 2 tiny vesicles on the oral mucosa that, on biopsy, confirmed the diagnosis of pemphigus vulgaris. CONCLUSION: Cytopathologists should be aware of the typical cytomorphologic features of pemphigus vulgaris and, in an appropriate clinical setting, should be able to diagnose or at least suspect this entity in even rare sites like the cervix. A false positive diagnosis of malignancy can be avoided if the cytologic findings are judiciously correlated with the history and with clinical and colposcopic examinations.     

The influence of steroid hormones on the uterine cervix during pregnancy

This paper reviews the evidence concerning the actions of steroid hormones on the connective tissues of the pelvis. Most available data concern the effects of steroids on the cervix. The time course of cervical softening in rats, sheep and humans suggests the possibility that the changes in connective tissue biochemistry that underlie the physiological phenomenon of cervical softening are under hormonal control. Both oestrogens and progestogens have been implicated in the control of cervical softening. However, recent experiments using inhibitors of 3 beta-hydroxysteroid dehydrogenase suggest that cervical softening can be produced in both sheep and humans by progesterone withdrawal in the absence of high circulating concentrations of oestradiol-17 beta.     

Pseudotumoral tuberculosis of the uterine cervix. Cytologic presentation

The cytologic presentation of a case of pseudotumoral tuberculosis of the uterine cervix is described. The presence in cervicovaginal smears of epithelioid cells arranged in clusters mixed with Langhans' giant cells was highly suggestive of tuberculosis. This diagnosis was confirmed by the detection of acid-fast bacilli in histologic preparations and cultures from biopsy specimens.     

Identification of cultured cell employing specific substance--with special references of "reserve cells" in uterine cervix

Identification of endocervical "reserve cell", which have been regarded as the origin of squamous cell carcinoma of the uterine cervix, was attempted employing immunohistochemically specific substances. The antigenicity of keratin, squamous cell carcinoma antigen(SCC), epithelial membrane antigen(EMA), tissue polypeptide antigen(TPA), vimentin, secretory component(SC) and placental alkaline phosphatase(PLAP) was investigated in histological preparations as well as cultured cells obtained from primary culture of endocervical tissue. The immunohistochemical findings in histological preparations revealed the following: a strongly positive reaction with TPA, a slightly positive reaction with EMA, a very slightly positive with SCC and PLAP, and a negative reaction with keratin, vimentin and SC. Cultured cells were divided into 4 groups according to their morphological characteristics; among these, small rounded or polygonal cells with a centric single nucleus showed similar immunocytochemical reactions to those of "reserve cells" in histological preparations, indicating that "reserve cell" can be growing in culture. The results obtained suggest that immunohistocytochemical specific substances may be useful to identify cultured cells.