Biomedical subjects

R Pilka

Publications and source records attributed to R Pilka.

At least 19 recordsLinked to original sources

PubMed2006

Endometrial expression of the estrogen-sensitive genes MMP-26 and TIMP-4 is altered by a substitution protocol without down-regulation in IVF patients.

BACKGROUND: The aim of this study was to analyse the effects of an estradiol (E(2))-progesterone substitution protocol on the endometrial expression of estrogen-sensitive genes during the peri-implantation period. METHODS: Peripheral blood and endometrial biopsies were obtained from 13 infertile women both in a natural cycle (NC), on days 5 and 7 after ovulation (NC5, NC7), and in an artificial (substituted) cycle (AC), on days 5 and 7 of progesterone addition (AC5, AC7). Estrogen receptor-alpha (ERalpha) and progesterone receptor (PR) were assayed by immunohistochemistry. Matrix metalloproteinase-26 (MMP-26) mRNA and tissue inhibitor of metalloproteinase-4 (TIMP-4) mRNA were semiquantitatively assessed in tissue sections using in situ hybridization (ISH) and quantified in tissue extracts using real-time PCR. RESULTS: Levels of both E(2) and progesterone were higher in the peripheral blood in AC than in NC. Also on day AC5, expressions of ERalpha, PR and MMP-26 mRNA (focally) were increased in the epithelium and TIMP-4 mRNA in the stroma. Expression levels of these genes dropped significantly between AC5 and AC7, but not between NC5 and NC7. Abnormally high levels in AC5 samples suggest overstimulation with E(2), and the rapid decrease between AC5 and AC7 suggests overstimulation with progesterone. CONCLUSIONS: In ACs, increased levels of E(2) in the blood exaggerate the endometrial expression of estrogen-sensitive genes, whereas higher levels of progesterone in the blood in the secretory phase exaggerate the drop in expression of these genes. Dramatic variations in the gene expression may not be optimal for the implantation process.

Adult↗

PubMed2006

Endometrial TIMP-4 mRNA is expressed in the stroma, while TIMP-4 protein accumulates in the epithelium and is released to the uterine fluid.

We have previously reported that endometrial mRNA expression of both tissue inhibitors of metalloproteinase-4 (TIMP-4) and matrix metalloproteinase-26 (MMP-26) peaks in the early secretory phase, which implies a role in implantation. The objective of this study was to compare the distribution of TIMP-4 and MMP-26 in endometrial tissue and uterine fluid over the menstrual cycle. Endometrial tissue was analysed with in situ hybridization and immunohistochemistry to localize mRNA and protein for TIMP-4 and MMP-26 in the same set of samples. TIMP-4 mRNA was quantified in separated stromal and epithelial cells using real-time PCR. Uterine fluid was analysed with western blotting. TIMP-4 mRNA was exclusively localized to the stroma, whereas MMP-26 mRNA was expressed by epithelial cells. TIMP-4 protein was only occasionally found in the stroma but was consistently present in granules of the apical part of luminal and glandular epithelial cells. TIMP-4, but not MMP-26, was demonstrated in uterine fluid. Thus, TIMP-4 is produced in the stroma only, secreted by stromal cells, taken up by epithelial cells, accumulated in apical granules and finally secreted to the uterine fluid. Maximal expression of MMP-26, and its strongest inhibitor TIMP-4, in the early and mid-secretory phase suggests a role during implantation. MMP-26 is stored in epithelial cells in its active form, is not released spontaneously and is controlled by TIMP-4 in both stroma and uterine fluid.

Adult↗

PubMed2006

[Sentinel lymph node detection using 99mTc-nanocolloid in endometrial cancer].

OBJECTIVE: The aim of this study was to evaluate the feasibility of pre-operative lymphoscintigraphy and radio-guided surgery in endometrial cancer patients after intramyometrial administration of labelled colloid. DESIGN: Prospective study. SETTING: Department of Obstetrics and Gynaecology of the Palacký University Medical School and University Hospital, Olomouc, Czech Republic. PATIENTS AND METHODS: Between April 2002 and March 2005, thirty three patients with endometrial cancer received pre-operatively 50 MBq of 99mTc-nanocolloid. The radiopharmaceutical agent was administered by a 25 Gauge needle transcervically into the myometrium. Subsequently, series of static lymphoscintigrams were made 20 to 90 min after injection. Two hours after injection the surgery started. Twenty eight patients underwent total abdominal hysterectomy, bilateral salpingo-oophorectomy and pelvic lymphadenectomy. Five patients were scheduled for laparoscopically assisted vaginal hysterectomy, bilateral salpingo-oophorectomy and pelvic lymphadenectomy. Paraaortal lymphadenectomy was performed in 11 cases. A gamma detecting probe was used to locate radioactive lymph nodes during operation. Each hot lymph node was removed separately. RESULTS: Sentinel lymph nodes (SLN) were identified in 26 (79%) of 33 patients. The mean number of sentinel nodes detected was 2.9 (range 1-10). Seventy two (15.3%) of 472 nodes obtained in total, were identified as radioactive-colloid positive. Histopathological analysis revealed five (7%) of 72 lymphonodes to be positive of metastases. Sentinel nodes in paraaortic area were identified in 11 (33%) patients. No false negative sentinel lymphonodes were observed. CONCLUSION: The preoperative lymphoscintigraphy and intraoperative gamma probe guided biopsy may be useful in identifying sentinel nodes in endometrial cancer. No false negative sentinel lymphonodes were observed if representative SLNs were diagnosed with tumor.

Adenocarcinoma↗

PubMed2006

[Molecular prognostic factors and pathogenesis of endometrial cancer].

OBJECTIVE: To evaluate the importance of molecular markers for prognosis and pathogenesis of endometrial carcinoma. DESIGN: A review article. SETTING: Department of Medical Genetics and Fetal Medicine, University Hospital, Olomouc, Department of Obstetrics and Gynecology, University Hospital, Olomouc. METHODS: This article reviews the current knowledge of the molecular changes in the development of endometrial cancer, and their possible importance for the patient's prognosis. CONCLUSION: The new molecular biomarkers are apparently going to play a significant role in the management of endometrial carcinoma treatment in the near future.

Biomarkers, Tumor↗

PubMed2006

[Preoperative assessment of myometrial invasion in endometrial cancer patients by ultrasonography and magnetic resonance imaging (MRI)].

OBJECTIVE: To compare the accuracy of transvaginal sonography and magnetic rezonance imaging (MRI) in determining the depth of myometrial invasion in proven cases of endometrial cancer. DESIGN: A prospective study. SETTING: Department of Obstetrics and Gynecology, Department of Medical Genetics and Fetal Medicine, Department of Radiology, University Hospital, Olomouc. METHODS: Fifty five patients diagnosed as having FIGO stage I endometrial carcinoma were evaluated preoperatively by transvaginal ultrasound; 44 cases of the same group were also evaluated by magnetic resonance imaging (MRI). The degree of invasion evaluated by transvaginal sonography and by MRI was compared to the pathological specimens. RESULTS: Transvaginal sonography was successful in evaluating myometrial invasion in 44 of 55 cases (accuracy 80%, sensitivity 80%, specificity 88%, positive predictive value 77%, negative predictive value 87%). Evaluation with MRI was accurate in 37 of 44 cases (accuracy 84%, sensitivity 84%, specificity 91%, positive predictive value 81%, negative predictive value 91%). CONCLUSION: Although MRI is superior to transvaginal sonography in evaluating myometrial invasion, it is expensive and time consuming, and would not be suitable as a screening test for depth of invasion. On the other hand, transvaginal sonography is relatively low-cost technique, which can be easily performed and repeated. However, it requires more operator experience than MRI in order to achieve high accuracy.

Carcinoma↗

PubMed2005

[MMP-26 mRNA and estrogen receptor alpha co-expression in normal and pathological endometrium].

OBJECTIVE: To examine the expression pattern of matrix metalloproteinase-26 (MMP-26) mRNA and estrogen receptor-alpha (ER alpha) in normal, hyperplastic, premalignant and malignant endometrial tissue. DESIGN: Experimental study. SETTING: Department of Obstetrics and Gynecology of the Palacky University Medical School and University Hospital, Olomouc, Czech Republic, Department of Obstetrics and Gynecology, University Hospital, Lund, Sweden, Atherosclerosis Research Unit, King Gustav V Research Institute, Karolinska Hospital, Stockholm, Sweden. METHODS: We studied MMP-26 mRNA and ER alpha in 36 normal, 7 hyperplastic, 6 premalignant and 19 malignant endometrial samples. Based on histological examination, all normal specimens were classified according to an ideal 28 day menstrual cycle as early, mid, and late proliferative phase, early, mid and late secretory phase and menstrual phase. Samples with hyperplasia were classified as simple or complex. Premalignant samples were represented by complex hyperplasia with atypia. Malignant samples were histologically classified as well, intermediately and poorly differentiated, respectively. Specimens were analyzed using in situ hybridization and real time PCR. ER alpha was localized by immunohistochemistry. RESULTS: Epithelial MMP-26 mRNA expression was highest in the early secretory phase and in endometrial hyperplasia. Expression levels were low in the late secretory and menstrual phase and in malignant samples decreased gradually with dedifferentiation. Expression pattern of MMP-26 mRNA in normal, hyperplastic, premalignant and malignant endometrial tissue strongly co-variated with that of ER alpha. CONCLUSION: Co-expression of MMP-26 and ER alpha in normal and pathological endometrial tissue suggests possible regulation of MMP-26 gene by estrogen.

Adult↗

PubMed2005

[Histological grade in management of carcinoma of endometrium].

OBJECTIVE: To correlate histological differentiation of endometrial cancer assessed from material obtained at diagnostic operation (hysteroscopy and targeted biopsy or curettage) and definitive radical surgical treatment. DESIGN: A prospective multicentric study. SETTING: Department of Obstetrics and Gynaecology, Institute of Pathology, Palacký University Medical School and University Hospital, Olomouc. MATERIAL AND METHODS: 237 patients with endometrial adenocarcinoma diagnosed between 1997-2001 were enrolled into this study. Histopathologic differentiation of tumoral tissue obtained at diagnostic and definitive radical operation were compared. RESULTS: Discrepancies in histopathologic differentiation of tumoral tissue obtained at diagnostic and definitive operation were found to be present in 42.2% of grade 1 (G1), 34.8% of grade 2 (G2), and 25.6% of grade 3 (G3) samples. When divided into subgroups, we observed discrepancies in 37.1% of G1, 31.5% of G2, and 26.7% of G3 tumors diagnosed at hysteroscopy and targeted biopsy. In patients with D&C the discrepancies were present in 53.1% of G1, 41.4% of G2, and 23.1% of G3 tumors. CONCLUSIONS: Low correlation between histopathologic differentiation of tumoral tissue obtained at diagnostic and definitive surgery supports the necessity of surgical staging in all patients with endometrial cancer. Primary radiotherapy should be reserved only for patients, in which the surgery is contraindicated.

Adenocarcinoma↗

PubMed2004

Endometrial TIMP-4 mRNA is high at midcycle and in hyperplasia, but down-regulated in malignant tumours. Coordinated expression with MMP-26.

We have previously reported that endometrial expression of matrix metalloproteinase (MMP)-26 mRNA comes to a maximum in the early secretory phase. Since tissue inhibitor of metalloproteinase (TIMP)-4 is a potent inhibitor of MMP-26, the objective of this study was to identify the pattern of TIMP-4 mRNA expression in the normal endometrial cycle. We also evaluated hyperplastic, pre-malignant (atypical hyperplasia) and malignant endometrial tissue. Endometrial TIMP-4 mRNA was localized in tissue sections using in situ hybridization, and quantified in tissue extracts using real-time PCR. Estrogen receptor alpha (ERalpha) was assayed in the same set of samples using immunohistochemistry. In situ hybridization demonstrated TIMP-4 mRNA in the stroma of both normal and pathological tissues. TIMP-4 mRNA increased in the proliferative phase to a maximum in the early secretory phase, and then decreased in the late part of the cycle. Expression was comparable in normal and hyperplastic (including atypical) endometrial samples, whereas lower levels were detected in malignant tumours. Since this general pattern of expression suggests estrogen dependence, we evaluated ERalpha in our samples. Tissue sections from the normal proliferative phase, hyperplasia and pre-malignant atypical hyperplasia tissue stained strongly for ERalpha, whereas weak staining was seen in the secretory phase and in malignant tumours. Thus, low level of ERalpha was accompanied by down-regulated TIMP-4 mRNA, supporting the hypothesis that ERalpha contributes to regulation of the TIMP-4 gene. In addition, we identified a putative estrogen response element (ERE) in the promoter region of the TIMP-4 gene at position -930 to -916. Similarities in the cyclic patterns of TIMP-4 mRNA and MMP-26 mRNA, together with the fact that TIMP-4 is a potent inhibitor of MMP-26, suggest a functional relationship, and furthermore a role in human implantation.

Adult↗

PubMed2004

Differential localization and expression of urokinase plasminogen activator (uPA), its receptor (uPAR), and its inhibitor (PAI-1) mRNA and protein in endometrial tissue during the menstrual cycle.

Normal endometrium is a highly dynamic tissue, which responds to ovarian steroids with cyclic proliferation, differentiation (secretion), and degradation (menstruation). The urokinase plasminogen activator (uPA)-dependent proteolytic cascade as well as ligand activation of the uPA receptor (uPAR) is critically involved in physiological as well as pathophysiological aspects of tissue expansion and remodelling. Cyclic variation and distribution of uPA, uPAR and plasminogen activator inhibitor 1 (PAI-1) mRNA were examined by in situ hybridization, real-time PCR and northern blot in normal endometrium. Their corresponding proteins were localized with immunohistochemistry. uPA mRNA is exclusively expressed by stromal cells, whereas uPA protein is present in both epithelial and stromal cells. Immunostaining for uPA protein is reduced or undetectable at midcycle, thus coinciding with peak concentration of uPA in the uterine fluid. uPAR mRNA is expressed by epithelial cells in the proliferative phase and by stromal cells in the secretory phase. However, epithelial cells stain for uPAR protein throughout the cycle, suggesting that uPAR may detach from stromal cells and then bind to epithelial cells in the secretory phase. PAI-1 mRNA is located in vessel walls. The late secretory phase has greatly increased expression of all three mRNA and their proteins, mainly in pre-decidual cells in the superficial stroma. Discordant localization of the mRNA and proteins suggest that uPA is produced by stromal cells, released and bound to epithelial cells in both the proliferative and secretory phases, whereas uPAR is released from the stroma and bound to epithelial cells in the secretory phase. Also, the present data together with earlier reports suggest that uPA is released from the epithelial cells to the uterine fluid.

Endometrium↗

PubMed2004

Matrix metalloproteinase-26 (matrilysin-2) expression is high in endometrial hyperplasia and decreases with loss of histological differentiation in endometrial cancer.

OBJECTIVE: Matrix metalloproteinases (MMPs) are key players in the degradation of extracellular matrix and basement membranes, and are thus important in tumor invasion. Recently, MMP-26 (endometase), a novel matrilysin-type member of the MMP family, was cloned from an endometrial tumor. This study examines the expression of MMP-26 mRNA in hyperplastic, premalignant and malignant endometrial samples, and compares with normal endometrial tissue. METHODS: Endometrial carcinoma samples (19) were histologically classified as well, intermediately and poorly differentiated. Samples with hyperplasia (n = 15) were classified as simple, complex, or complex with atypia. Normal endometrial specimens (n = 39) were classified according to an ideal 28-day menstrual cycle and subsequently grouped in the early, middle, and late parts of the cycle. All samples were analyzed using in situ hybridization and real time PCR. The probes used for in situ hybridization and real time PCR recognized non-overlapping sequences. MMP-26 protein was localized by immunohistochemistry. RESULTS: MMP-26 mRNA was exclusively localized in the epithelial component of normal, hyperplastic, premalignant, as well as malignant samples. It was not found in the stroma of any tissue category. Quantifications with real time PCR as well as semi-quantifications of the in situ hybridization signal revealed maximal levels in normal tissue at midcycle and in endometrial hyperplasia both with and without atypia. The amount of MMP-26 mRNA decreased progressively with loss of histological differentiation in malignant samples. Immunostaining localized MMP-26 in epithelial glandular and luminal cells, in vessel walls, and in tumor cells. Since the pattern of MMP-26 expression mimicked that of ER-alpha, we searched the MMP-26 promoter region for a potential estrogen response element (ERE). A sequence at position -130 to -116 had high homology to the consensus sequence of an ERE. Based on these observations, we suggest that ER-alpha is involved in regulation of the MMP-26 gene. CONCLUSIONS: MMP-26 mRNA is selectively localized in the epithelial compartment of normal, hyperplastic, and malignant endometrial tissue. Expression is high in normal and hyperplastic endometria, but is downregulated in the late part of the cycle and in malignant tumors. The expression pattern of MMP-26 mRNA mimics that of ER-alpha, and the promoter region of the MMP-26 gene has a potential ERE.

Adult↗

PubMed2004

[Preoperative detection of lymph nodes by means of computer tomography in patients with endometrial carcinoma].

OBJECTIVE: To determine the value of computed tomography (CT) in predicting preoperatively nodal disease in patients with endometrial cancer. DESIGN: A prospective multicentric study. SETTING: Department of Obstetrics and Gynecology of the Palacky University Medical School and University Hospital, Olomouc, Obstetrical and Gynecological Departments of collaborating hospital, Czech Republic. METHODS: A total of 164 women with endometrial carcinoma that was diagnosed between 1998 and 2002 were recruited for this study. Final pathological findings were compared with those of the preoperative CT scans to assess nodal disease. RESULTS: Among 164 women who had preoperative scans and lymph node samplings, sensitivity, specificity, positive and negative predicting values of CT scans at predicting lymph node metastasis was 30, 95.5, 30 and 95.5% respectively. CONCLUSION: Routine preoperative CT scanning is a poor predictor of nodal disease in patients with endometrial cancer. Its preoperative routine use should be discouraged.

Adult↗

PubMed2004

[Novel matrix metalloproteinases in cycling endometrium].

OBJECTIVE: To examine the expression pattern of some novel matrix metalloproteinases (MMPs) in cycling endometrium. DESIGN: Experimental study. SETTING: Department of Obstetrics and Gynecology of the Palacky University Medical School and University Hospital, Olomouc, Czech Republic, Department of Obstetrics and Gynecology, University Hospital, Lund, Sweden. METHODS: We studied MMP-12, -16, -17, -19 and -26 mRNA in 39 normal endometrial samples obtained across the menstrual cycle. Based on histological examination, all specimens were classified according to an ideal 28 day menstrual cycle as early (n=8), mid (n=6) and late (n=7) proliferative phase, early (n=4), mid (n=4) and late (n=8) secretory phase and menstrual (n=3) phase. Cycle variation was examined in frozen samples using in situ hybridization. RESULTS: Three distinct pattern of MMP mRNA expression were detected in cycling endometrium. MMP-12 was expressed predominantly in perimenstrual period, MMP-16, -17 and 19 were expressed throughout the cycle and MMP-26 was found to be maximal in periovulatory period. CONCLUSION: Different endometrial expression patterns of novel MMPs during menstrual cycle may indicate their specific roles for menstruation, endometrial growth and remodelling and implantation.

Adult↗

PubMed2004

[MMP-26 expression in endometrial explants treated with estradiol and progesterone].

OBJECTIVE: To examine possible estrogen dependent endometrial expression of MMP-26 in vitro. DESIGN: Experimental study. SETTING: Department of Obstetrics and Gynecology of the Palacky University Medical School and University Hospital, Olomouc, Czech Republic, Department of Obstetrics and Gynecology, University Hospital, Lund, Sweden. METHODS: We studied MMP-26 mRNA in 14 normal endometrial samples obtained from the proliferative phase of the menstrual cycle. Samples were cultured for five days either with estradiol alone or in combination with progesterone. Samples cultured with ethanol represented control groups. MMP-26 mRNA expression was examined in frozen samples using in situ hybridization. Immunohistochemistry was used to study the presence of estrogen and progesterone receptors in endometrial explants. RESULTS: MMP-26 mRNA expression was highest in fresh (non cultured) samples. Signal intensity decreased during the first two days of culture and was negligable in the following days. Nuclear intensity for estrogen and progesterone receptor was high after five days of culture. CONCLUSION: We did not find MMP-26 mRNA in vitro expression to be directly estrogen dependent.

Adult↗

PubMed2004

[Endometrial expression profiles of mRNA for selected matrix metalloproteinases and tissue inhibitor of metalloproteinases-1].

OBJECTIVE: To examine the endometrial expression pattern of messenger RNA (mRNA) for selected matrix metalloproteinases (MMP) and tissue inhibitor of metalloproteinases-1 (TIMP-1). DESIGN: Experimental study. SETTING: Department of Obstetrics and gynecology of the Palacky University Medical School and University Hospital, Olomouc, Czech Republic, Department of Obsterics and Gynecology, University Hospital, Luna, Sweden. METHODS: We studied MMP-1, -3, -7, -10, -11, -12, -13, -14, -16, -26 and TIMP-1 mRNA in 39 normal endometrial samples obtained across the menstrual cycle. Based on histological examination, all specimens were classified according to an ideal 28 day menstrual cycle as early (n=8), mid (n=6) and late (n=7) proliferative phase, early (n=4), mid (n=4) and late (n=8) secretory phase and menstrual (n=3) phase. mRNA extracted from frozen tissue samples was quantitated using real time PCR. RESULTS: Four distinct patterns of MMP mRNA expression were detected in cycling endometrium. MMP-1, -3, -10, and -12 were expressed predominantly in perimenstrual period, MMP-7 and -11 had highest levels in proliferative phase, MMP-13, -14 and -16 were expressed throughout the cycle and MMP-26 was found to be maximal in periovulatory period. Levels of TIMP-1 mRNA remained unchanged during the cycle. CONCLUSION: The specific endometrial expression profiles of MMPs during menstrual cycle point to their specific biologic roles during the cycle. MMP-26 exhibits a unique expression pattern.

Adult↗

PubMed2004

[Sacrospinous fixation of the prolapsed vagina after the Miyazaki hysterectomy procedure].

OBJECTIVE: Implementation of a new surgical method for treatment of vaginal prolapse after hysterectomy. DESIGN: The description of a new surgical method. The results in the first 16 patients. SETTING: Department of Obstetric and Gynecology, Medical Faculty of the Palacký University and University Hospital, Olomouc. METHODS: The description of a new surgical method, pointing out the advantages and possibilities of the use in clinical practice. Presentation of the results in the group of 16 patients treated. CONCLUSIONS: Sacrospinous fixation of vaginal prolapse after hysterectomy sec. Miyazaki is a modification of sacrospinous fixation sec. Amreich-Richter. Contrary to the classical procedure this new method has several advantages. It makes easier the exact placement of the stitches to the sacrospinous ligament which decreases the danger of bleeding often substantially complicating the classical procedure. The procedure requires a special instrument, namely the so called Miyazaki hook. The results in the first 16 patients operated on by this method are presented.

Female↗

PubMed2003

Epithelial expression of matrix metalloproteinase-26 is elevated at mid-cycle in the human endometrium.

The human endometrium is a dynamic tissue, which undergoes extensive tissue remodelling during the menstrual cycle. Due to their involvement in such processes, several well-characterized matrix metalloproteinases (MMP) have previously been studied in the endometrium. MMP-26 is a newly described matrilysin. We studied MMP-26 mRNA in 39 normal endometrial samples obtained across the menstrual cycle. Tissue distribution and cycle variation was examined using in-situ hybridization, Northern blot analyis and real time PCR. The probes for Northern blot analysis and real time PCR recognized non-overlapping sequences. MMP-26 was localized exclusively in epithelial cells of both glands and the luminal surface. Expression increased during the proliferative phase to a maximum at mid-cycle, then decreased to non-detectable levels in the late secretory and menstrual phases. Expression of MMP-26 mRNA in endometrial tissue explants in vitro required stimulation with both estradiol and progesterone. The tissue content of c-jun mRNA was assayed, since c-jun, as part of the enhancer complex AP-1, may be involved in regulation of MMP-26 gene transcription. The pattern of c-jun expression over the menstrual cycle was similar to that of MMP-26. Epithelial expression in the peri- and post-ovulatory stages of the menstrual cycle suggests the involvement of MMP-26 in reproductive processes.

Actins↗

PubMed2003

[Matrix metalloproteinases and menstruation].

During every menstrual cycle the extracellular matrix in the uterus undergoes dramatic changes associated with release and shedding of the endometrium. Classical investigations made in monkeys assumed that menstruation is caused by vasoconstriction, hypoxia and subsequent necrosis. More recent work indicates the importance of the system of the system of matrix metalloproteinases (MMP) for the extracellular architecture of the endometrium. The submitted paper presents a review of crucial characteristics of the MMP system and its importance for cyclic transformation of the endometrium during the menstrual cycle. From the review it is apparent that impairment of the MMP equilibrium and its tissue inhibitors are an essential prerequisite of tissue degradation and menstruation. MMP activation is regulated by hypoxia, a drop progesterone and paracrine factors released by epithelial, stromal and migratory cells.

Endometrium↗

PubMed2003

[Oocyte donation: ethical and practical questions].

AIM OF THE STUDY: This review will summarize the current view on ethical and practical aspects involved in ovum donation. STUDY DESIGN: Literature review. INSTITUTION: Center of Reproductive Medicine, Zlín; Department of Gynecology and Obstetrics, Palacký University, Olomouc. CONCLUSION: Today there are three possible ways of recruiting ovum donors: 1) volunteer ovum donors, 2) related donors (searched by couples in need), 3) in vitro fertilization patients (egg-sharing).

Female↗