Stem cells: are they the answer to the puzzling etiology of endometriosis?

Endometriosis is a chronic benign disease characterized by the presence of abnormally located tissue resembling the endometrium with glands and stroma. This disease has a high degree of morbidity due to chronic pelvic pain and infertility. The disease is likely to be polygenic and multifactorial, but the exact pathogenic mechanisms are still not entirely clear. Recently, adult stem cells have been identified in several tissues, including the endometrium. These cells are probably involved in the regenerative ability of the endometrial cycle, and also in the pathogenesis of proliferative gynaecological diseases, such as endometriosis. The identification of stem cells in animal and human tissues is very complex and the putative stem cells are supposed to be found through several assays such as clonogenicity, label-retaining cells, "side-population" cells, undifferentiation markers, and cellular differentiation. Bone marrow-derived stem cells transplanted into humans and animals have also been identified in eutopic endometrium and endometriotic implants. This review evaluates the available evidence regarding stem/progenitor cells in the human endometrium and explores the possible involvement of these cells in the etiology of endometriosis.

The effect of buserelin acetate on the uterus of adult rats: morphological aspects

PURPOSE OF INVESTIGATION

To evaluate the effect of buserelin acetate on the morphology of the endometrium of adult, non-castrated, female Wistar rats.

METHODS

Female Wistar rats at estrus or diestrus (assessed by vaginal cytology) received daily subcutaneous injections of 20 mg buserelin acetate for four, eight or 12 days. Rats were sacrificed 24 hours or five days following final dosage. A control group received diluent for 12 days.

RESULTS

Progressive tissue hypotrophy occurred during treatment and was followed by estrogenic hyperactivity five days after the end of treatment. Vaginal cytology and endometrial histology revealed intense, vacuolized lining and glandular epithelia, brush borders and endometrial stroma densely infiltrated with eosinophils.

CONCLUSIONS

Buserelin acetate appears to cause a progressive blockade of gonadotrophin secretion when administered to female rats for four, eight or 12 days, and an important rebound effect, with accentuated estrogen release already apparent in the first estrous cycle following treatment.

Effects of simultaneous treatment with estrogen and testosterone on the uterus of female adult rats

BACKGROUND

Testosterone (T) associated with estrogen (E) has been used in hormonal replacement therapy in postmenopause women and the effects of this hormonal association on the uterus are not known.

OBJECTIVE

To study the effect of long-term simultaneous exposure to testosterone and estrogen on the uterus of non-castrated adult female rats.

METHODS

Groups of ten adult noncastrated female Wistar rats were treated with non-esterified testosterone and beta estradiol (subcutaneous implants with 50 mg of each hormone) or with testosterone cipionate and estradiol valerate (weekly intramuscularly or by subcutaneous injection of respectively, 2.85 mg/kg and 0.166 mg/kg). Control groups received no treatment (10 rats) or injections of diluents (6 rats). All animals were killed six months after hormonal exposure.

RESULTS

All rats treated with T+E developed hyperplasia and hyperkeratosis of the vaginal and cervical epithelium and focal metaplasia with keratinization of the endocervical and endometrial epithelium. Ascending pelvic inflammatory disease with pyometra and tuboovarian abscesses were frequent (25% mortality until the end of the experiment).

CONCLUSIONS

Testosterone associated with estrogen induced metaplasia of the genital epithelium but did not induce neoplastic lesions. The metaplasic lesions reduced the mucosal defense mechanisms enhancing ascending genital inflammatory disease. Although metaplasia of the cervical and endometrial epithelium has been observed after estrogen exposure in rats, testosterone does not appear to inhibit these estrogen effects.

Morphological changes induced by testosterone in the mammary glands of female Wistar rats

Increased levels of androgens in postmenopausal women are considered to be a risk factor for breast cancer. Testosterone, alone or in combination with estrogen, induces epithelial dysplasia and mammary tumors in Noble rats. Since this model of hormone-induced neoplasia has not been reported in other rat strains, we studied the effect of testosterone on the mammary gland morphology of female Wistar rats. Sixty adult, non-castrated, female Wistar rats were implanted in the dorsum midline with a silicone tube containing 50 mg testosterone (testosterone propionate in 30 animals and non-esterified testosterone in the remaining 30 animals) and 20 additional animals were implanted with empty tubes and used as control. Five animals per group were killed 30, 60, 90, 120, 150, and 180 days after implantation, and the mammary glands were dissected, fixed and embedded in paraffin. Histological sections were then stained with hematoxylin and eosin and picrosyrius red for collagen visualization. Morphological and morphometric analysis demonstrated ductal proliferation and acinotubular differentiation with secretory activity in all treated animals, peaking at 90 days of androgen exposure. After 90 days the proliferation of acinar epithelial cells was evident, but there was a progressive reduction of secretory differentiation and an increase in intralobular collagen fibers. There was no morphological evidence of dysplastic changes or other pre-neoplastic lesions. Testosterone treatment applied to adult, non-castrated female Wistar rats induced a mammary gland hyperplasia resembling the lactating differentiation, with progressive reduction in secretory differentiation.

Activin, inhibin and the human breast

Activins and inhibins are growth factors involved in cell differentiation and proliferation. Human breast tissues such as normal mammary tissue, fibroadenoma, and breast cancer express inhibin and activin mRNA and proteins. Activin A and its binding protein, follistatin, are also present in human milk during the first week of lactation. Using immunohistochemistry, we have observed that the inhibin/activin alpha, betaA, and betaB subunits are present in normal breast tissue regardless of menstrual cycle phase or menopause, as well as in fibrocystic disease, and breast tumors. The mRNAs encoding all three activin/inhibin subunits are expressed in breast carcinoma, fibroadenoma, and normal mammary tissue. The betaA subunit gene expression is higher in either local or metastatic breast carcinoma than in normal tissue. In addition, dimeric activin A is detectable in homogenates of breast cancer tissue at concentrations twice as high as in non-neoplastic adjoining tissue. Recent evidence suggests that some of the activin A produced by breast carcinoma is released into systemic circulation. In women with breast cancer, serum activin A levels are often elevated, and a significant decrease is observed in the first and second days following tumor excision. The role of activin and inhibin as endocrine and/or paracrine factors in the breast is still uncertain. Activin has complex effects on cell growth during branching morphogenesis, but it is generally considered as an inhibitor of cell proliferation as in vitro studies have shown that activin A treatment of breast cancer cells arrests cell growth. Inhibin is generally considered as a tumor suppressor, but its possible role in the breast is less understood.

Quinacrine female nonsurgical sterilization (QS): endometrial assessment by vaginal ultrasonography in 128 women

OBJECTIVE

Investigate effectiveness, safety and endometrial pattern after QS.

METHOD

This study began in March 1999 and ended March 18, 2003; 128 women received transcervical insertions of quinacrine. Follow-up visits with ultrasound were scheduled at 1, 3, 6, 12-month intervals.

RESULTS

Two pregnancies occurred, one at 25 months, the other at 37. Adverse events (AE) were: yellow vaginal discharge, headache, mild abdominal pain, vaginal pruritus, nausea and transient decrease in endometrial thickness. One patient had allergic reaction. A third insertion was done in case of vaginal bleeding (16.4%). One year after QS 10% still had amenorrhea, which may be the result of the fact that 73% of our patients had received DMPH. Once inside the uterus, the dissolved quinacrine could be seen within seconds, via ultrasound as a "Lake of Quinacrine" which stays for up to two hours. Frequently, a transverse vaginal ultrasonographic view of the uterine cavity showed plug-like echogenic points at the cornua.

CONCLUSION

Quinacrine sterilization is safe and effective. The echogenic points need to be more thoroughly studied in order to affirm whether ultrasonography may identify the blockage of the tubes. Since early pregnancy is due to imperfect tubal closure, the use of ultrasound may prevent failure. However, pregnancy due to later recanalization cannot be avoided.

Risk factors for breast cancer among pre- or post-menopausal women in Belo Horizonte, Brazil

BACKGROUND

Much controversy has been generated about pre- and post-menopausal breast cancer patients and investigators have sought to identify whether risk factors differ between these two groups. In Brazil, breast cancer is an important cause of death among women and there are few analytical studies concerning pre- or post-menopausal comparisons.

METHODS

A case-control study was carried out at the Federal University Hospital, Belo Horizonte, Brazil, to determine if selected socio-economic and reproductive risk factors for breast cancer differed between pre-menopausal and post-menopausal women. Cases were 300 women with breast carcinoma and controls were 600 women with other benign diseases matched for age and date of diagnosis, admitted to the same hospital during the same period (1978-1987). Univariate and multivariate conditional logistic regression analyses were performed.

RESULTS

Multivariate analysis showed no differences in breast cancer risk in pre- and post-menopausal women (risk factors were similar in direction and magnitude). Occupation, irregular menstrual cycles, parity, history of breast cancer in at least one first-degree female relative, and oral contraceptive use had similar associations in both groups.

CONCLUSIONS

The present study indicates that breast cancer diagnosed before and after menopause has a similar risk profile.

Diagnostic accuracy of sonohysterography, transvaginal sonography, and hysterosalpingography in patients with uterine cavity diseases

OBJECTIVE

To evaluate the diagnostic accuracy of sonohysterography (SHG) in uterine cavity diseases in infertile patients, comparing its results with those of hysterosalpingography (HSG) and transvaginal sonography (TVS). Hysteroscopy was the gold standard.

DESIGN

Descriptive, prospective study.

SETTING

A tertiary university referral center.

PATIENT(S)

Sixty-five infertile women 19 to 43 years of age.

INTERVENTION(S)

Patients underwent SHG, conventional TVS, HSG, and hysteroscopy.

MAIN OUTCOME MEASURE(S)

The results of each examination were compared with those obtained by the gold standard. The following diagnoses were considered separately: polypoid lesions, uterine malformations, intrauterine adhesions, and endometrial hyperplasia (EH). Sensitivity, specificity, positive and negative predictive values (PPV and NPV, respectively), and 95% confidence intervals were calculated.

RESULT(S)

Sonohysterography had the same diagnostic accuracy as the gold standard for polypoid lesions and EH, with no equivocal diagnosis. Hysterosalpingography showed a sensitivity of 50% and a PPV of 28.6% for polypoid lesions and a sensitivity of 0% for EH. Transvaginal sonography had both sensitivity and PPV of 75% for polypoid lesions and EH. For uterine malformations, SHG had a sensitivity of 77.8%, whereas TVS and HSG both had a sensitivity of 44.4%. Sonohysterography and HSG had a sensitivity of 75% in the detection of intrauterine adhesions and respective PPVs of 42.9% and 50%. Transvaginal sonography showed sensitivity and PPV of 0% for this diagnosis.

CONCLUSION(S)

Sonohysterography was in general the most accurate test. Its diagnostic accuracy was markedly superior for polypoid lesions and EH, with total agreement with the gold standard. In diagnosis of intrauterine adhesions, SHG had limited accuracy, similar to that obtained by HSG, with a high false-positive diagnosis rate.

Hysterosalpingo contrast sonography (HyCoSy) with SH U 454 (Echovist) for the assessment of tubal patency

A total of 88 Fallopian tubes from 44 patients was examined with hysterosalpingo contrast sonography (HyCoSy), hysterosalpingogram (HSG), and laparoscopic chromopertubation (LC) in order to assess their relative accuracy for measuring tubal patency. HyCoSy was done by transvaginal ultrasound and the contrast was SH U 454 (Echovist). The flow of multiple fractions of the contrast medium through each Fallopian tube was observed in real time in appropriate imaging planes by means of a transvaginal probe. Compared with laparoscopic results, we found a sensitivity of 85.2%, a specificity of 85.2%, a positive predictive value (PPV) of 71.9%, a negative predictive value (NPV) of 92.9% and concordance (HyCoSy/LC) of 85.2%, while the corresponding values for HSG were sensitivity = 85.2%, specificity = 83.6%, PPV = 69.7%, NPV = 92.7% and concordance (HSG/LC) of 84.1%. Compared with HSG results, HyCoSy obtained a co-positivity of 66.7%, a co-negativity of 81.8% and a concordance of 76.1%. In conclusion, HyCoSy with SH U 454 proved to be a reliable and safe modality for evaluating tubal patency; it is suitable as an outpatient diagnostic procedure to be used before more invasive procedures.

A case-control study of risk factors for breast cancer in Brazil, 1978-1987

BACKGROUND

There are still controversies regarding the role of many risk factors assessed for breast cancer worldwide. In Brazil, it represents a major cause of death among women but yet few analytical studies have been published to date.

METHODS

The association of selected factors with breast cancer was assessed in a case-control study of 300 women, aged 25-75 years, treated at the Federal University Hospital, Belo Horizonte, Brazil, from 1978 to 1987. In all, 300 cases with diagnosed breast carcinoma were compared with 600 controls matched on age and date of diagnosis. Socio-economic, demographic and reproductive factors were analysed.

RESULTS

Multiple logistic regression analysis showed the following factors to be independently associated with increased risk of breast cancer: a) monthly family income (odds ratio [OR] = 1.69, 95% confidence interval [CI]: 1.18-2.42); b) being a housewife (OR = 2.86, 95% CI: 1.83-4.47; c) parity of less than six deliveries and nulliparous women (OR = 5.06, 95% CI: 3.01-8.52 and OR = 2.42, CI: 1.64-3.59, respectively); d) history of breast cancer among first degree female relatives (OR = 9.35, 95% CI: 3.22-27.14); and e) oral contraceptive use (OR = 1.81, 95% CI: 1.15-2.85). Irregular menstrual cycle (OR = 0.44, 95% CI: 0.25-0.75) was associated with breast cancer as a protective effect.

CONCLUSIONS

The study has confirmed most risk/protective factors previously demonstrated elsewhere in the world and provides clear documentation of breast cancer epidemiology in Brazil.