26
|
Rabe T, Kowald A, Ortmann J, Rehberger-Schneider S. Inhibition of skin 5 alpha-reductase by oral contraceptive progestins in vitro. Gynecol Endocrinol 2000; 14:223-30. [PMID: 11075290 DOI: 10.3109/09513590009167685] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Androgenic disorders of female skin such as hirsutism, acne and alopecia are etiologically caused by androgen excess. Skin 5 alpha-reductase activity is a major factor influencing the manifestation of endogenous androgen excess in women. Oral contraceptives have proven useful for the treatment of androgen disorders of the skin. The mechanisms of action by which oral contraceptives correct skin androgen levels may include inhibition of 5 alpha-reductase and androgen receptor activity. We investigated the inhibitory effect of oral contraceptive progestins and ethinyl estradiol on skin 5 alpha-reductase and their influence on androgen receptor activity and affinity, using three different in vitro assay systems. It was shown that norgestimate blocked 5 alpha-reductase activity with an IC50 value of 10 microM, followed by levonorgestrel (IC50 52 microM), dienogest (IC50 55 microM), cyproterone acetate (IC50 87 microM) and gestodene (IC50 98 microM). To determine the full androgenic potential of the progestins, androgen receptor binding affinities and activation potentials were determined. The progestins norgestimate and dienogest in particular combined 5 alpha-reductase inhibition with minimal androgenic potential. These data demonstrate that the progestins norgestimate and dienogest might help in the treatment of clinical hyperandrogeny in women.
Collapse
|
27
|
Zschocke S, Rabe T, Taylor JL, Jäger AK, van Staden J. Plant part substitution--a way to conserve endangered medicinal plants? JOURNAL OF ETHNOPHARMACOLOGY 2000; 71:281-292. [PMID: 10904175 DOI: 10.1016/s0378-8741(00)00186-0] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Population growth, urbanization and the unrestricted collection of medicinal plants from the wild is resulting in an over-exploitation of natural resources in southern Africa. Therefore, the management of traditional medicinal plant resources has become a matter of urgency. In southern Africa the most frequently used medicinal plants are slow-growing forest trees, bulbous and tuberous plants, with bark and underground parts being the parts mainly utilized. A strategy which would satisfy the requirements of sustainable harvesting, yet simultaneously provide for primary health care needs, would be the substitution of bark or underground parts with leaves of the same plant. This paper outlines the concept of plant substitution, using preliminary results of our recent investigations into four of the most important and most threatened South African medicinal plants - Eucomis autumnalis (bulb), Siphonochilus aethiopicus (rhizome), Ocotea bullata (bark), and Warburgia salutaris (bark) - as a demonstration of the kind of research necessary. Extracts of various plant parts were compared chemically using TLC-analysis, and pharmacologically in terms of antibacterial activity and cyclooxygenase-1 inhibition in vitro. The importance of the concept of plant part substitution as a strategy for the conservation of medicinal plants in southern Africa is discussed in terms of the results obtained.
Collapse
|
28
|
Garbe E, Heinemann LA, Rabe T, Winkler UH. [Non-contraceptive benefits of the pill--an often neglected fact]. ZENTRALBLATT FUR GYNAKOLOGIE 2000; 122:18-27. [PMID: 10785947] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
While rare cardiovascular risks of oral contraceptives (OCs) caused a lot of concern among OC-using women in the recent past, little attention has been paid in the public to the non-contraceptive benefits of OCs. Short, medium and long term non-contraceptive benefits have to be considered. The early Anglo-American cohort and case-control studies demonstrated a reduction of menstrual complaints, iron-deficiency anaemia, ectopic pregnancies, and a partly drastic reduction of some benign and malignant tumours such as endometrial and ovarian cancer. A risk reduction of rheumatoid arthritis is discussed controversially. The present paper gives an overview of the state of knowledge. For newer OCs with different composition, comparable studies are lacking. Therefore, a cohort study was initiated in Germany in April 1998 to investigate these associations as well for newer OCs, which is presented. The described non-contraceptive benefits should be considered in the benefit-risk assessment when prescribing OCs.
Collapse
|
29
|
Heinemann LA, Garbe E, Winkler UH, Rabe T. [German Cohort Study of Women's Health--benefits of oral contraceptives. Study protocol]. ZENTRALBLATT FUR GYNAKOLOGIE 2000; 122:112-5. [PMID: 10721193] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/15/2023]
Abstract
This publication is about the study protocol of the German Cohort Study on Women's Health. The main objective is to investigate medical benefits of a long-term oral contraceptive use. The design is an analytical cohort study based on inquiries. Additional cases will be recruited to analyse rare events in separate case-control studies. Voluntary participants who signed to participate in a long-term study are included. An annual drop-out rate of 15% is expected. Study variables encompass personal characteristics, lifetime history of diseases, but also disturbances of the state of health, and quality of life. It is anticipated to achieve 400,000 women-years of observation by 2001 (historic and concurrent follow-up). The study started April 1, 1998 and the current financial phase finishes December 31, 2001. 6000 participants were recruited until December 1998 equivalent to about 190,000 observation-years. Until the end of 1999, an additional 70,000 women-years should be included. There have been many suggestions from participants' to include additional issues of women's health into the study.
Collapse
|
30
|
Rabe T, Bohlmann MK, Rehberger-Schneider S, Prifti S. Induction of estrogen receptor-alpha and -beta activities by synthetic progestins. Gynecol Endocrinol 2000; 14:118-26. [PMID: 10836199 DOI: 10.3109/09513590009167670] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The cellular action of steroid hormones is mediated by specific receptors. Recently, two different estrogen receptors (ER), alpha and beta, have been cloned with a specific tissue distribution. Active estrogen as well as active progestin are compounds of oral hormonal contraceptives and hormone replacement therapy. To examine the regulation of ER-alpha and -beta activities after treatment with synthetic progestins and synthetic and natural estrogens, COS 7 cells were transfected with the vector expressing ER-alpha and -beta in combination with a luciferase reporter vector. ER-alpha activity was upregulated in the presence of synthetic progestins in a dose-dependent manner. Norethisterone, norethynodrel and desogestrel proved to be the most potent stimulatory agents of ER-alpha expression. On the other hand, not all progestins exhibited a stimulatory action on ER-beta activity. Only norgestrel, levonorgestrel, norethynodrel and norethisterone induced ER-beta-activating functions in a dose-dependent manner. Luciferase activity due to estrogen stimulation served as a positive control. Our results indicate that progestins have different effects on the activities of ER-alpha and -beta.
Collapse
|
31
|
Vladescu E, Munteanu I, Mueck A, Salbach B, von Holst T, Rabe T. Carbohydrate metabolism in postmenopausal patients treated with transdermal estradiol and norethisterone acetate. Int J Gynaecol Obstet 2000. [DOI: 10.1016/s0020-7292(00)84638-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
|
32
|
Eberhardt I, Rosenberg K, v. Hagens C, Rabe T, Strowitzki T. R-056. Re-insemination of oocytes after fertilization failure during IVF treatment leads to pregnancies. Hum Reprod 1999. [DOI: 10.1093/humrep/14.suppl_3.304] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
|
33
|
Rosenberg K, Mall P, Rehberger S, Rabe T. O-164. Synthetic oestrogens activate intracellular signalling molecules (ERK and JNK) related to growth-factor signalling in human breast-cancer cells. Hum Reprod 1999. [DOI: 10.1093/humrep/14.suppl_3.91] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
|
34
|
Vladescu E, Rabe T, Munteanu I, Meinhardt H, Strowitzki T. R-111. Measurement of intravaginal cervical mucus resistance for evaluation of follicular development and ovulation in women. Hum Reprod 1999. [DOI: 10.1093/humrep/14.suppl_3.328-a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|
35
|
Grunwald K, Feldmann K, Melsheimer P, Rabe T, Neulen J, Runnebaum B. Aneuploidy in human granulosa lutein cells obtained from gonadotrophin-stimulated follicles and its relation to intrafollicular hormone concentrations. Hum Reprod 1998; 13:2679-87. [PMID: 9804213 DOI: 10.1093/humrep/13.10.2679] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Proliferation of granulosa cells is inversely related to differentiation and hormone production. The purpose of this study was to evaluate the intrafollicular and serum steroid concentrations and to compare these results to granulosa cell proliferation as measured by DNA flow cytometry. Human granulosa lutein cells in follicular fluid of in-vitro fertilization (IVF) patients were investigated with regard to ploidy, percentage of S-phase cells and proliferation index (PI: percentage of cells in the S- and G2/M-phase). The study was originally designed to indicate an additional marker for the outcome of IVF treatment by DNA flow cytometric measurements of granulosa lutein cells. Follicular fluids of 160 follicles (45 patients) were evaluated; 45.6% (n = 73) of the follicles showed aneuploid granulosa lutein cells and 5.6% (n = 9) of the follicles contained multiploid granulosa cells, defined as at least two aneuploid populations of cells with different DNA indices. A total of 48.8% (n = 78) of the follicles had only diploid cells. Thus >50 % of the investigated follicles showed aneuploidy. In all, 73% (33 of 45) of patients had at least one follicle containing aneuploid granulosa lutein cells. The PI of the aneuploid cell populations significantly exceeded that of the diploid cell populations (median: aneuploid: 15.5; diploid: 7.4; P < 0.0001). The intrafollicular concentrations of testosterone, progesterone and dehydroepiandrosterone sulphate (DHEA-S) were significantly lower in follicles with aneuploid granulosa cell populations. Luteinizing hormone concentration was significantly higher in follicles with aneuploid granulosa cells. Intrafollicular concentrations of oestradiol, follicle stimulating hormone and the serum concentrations of all steroid hormones did not show any significant correlation to ploidy. Although aneuploidy has been reported for oocytes (in approximately 17% of the oocytes), no study, to our knowledge, has observed such a high incidence of aneuploidy in granulosa lutein cells after gonadotrophin stimulation. Except for aneuploidy found in tissues with some characteristics of neoplastic growth (colon adenoma, borderline tumours, endometriosis with atypic cells, etc.), it is unique for non-malignant human cells. The correlation with intrafollicular steroid concentrations points to a possible pathophysiological or physiological relevance of these findings. However, it was impossible to correlate the outcome of IVF with DNA flow cytometry results.
Collapse
|
36
|
Jambou R, Tombo ML, Raharimalala L, Rakotonjanabelo A, Rabe T, Laventure S, Boisier P. [Malaria in Antananarivo: evaluation of a post-epidemic situation]. SANTE (MONTROUGE, FRANCE) 1998; 8:257-64. [PMID: 9794035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
Antananarivo has a population of close to one million inhabitants and is located in the highlands of Madagascar. The capital was, until some years ago, thought to be a malaria transmission-free zone. However, between 1985 and 1990, several malaria cases occurred in the suburbs of Antananarivo, along the Ikopa river (the Betsimitatatra Plain), suggesting that local transmission was occurring. Numerous malaria cases have since been reported by health workers each year, but there is insufficient epidemiological information about the cause and origin of the transmission, because cases are rarely confirmed by parasitological examination. The National Malaria Control Management in Madagascar has, after four years of intensive DDT spraying campaigns in the highlands, stopped this specific method of control. Epidemiological follow-up studies will be carried out to evaluate the effects on malaria transmission of this cessation of control measures. The transmission of malaria in Antananarivo was studied from 1995 to 1996. Patients from nine health centers in various suburbs of Antananarivo were included in the study, with the presence of fever used as the sole inclusion criterion. Children randomly selected from schools in the same area were included in a second study group. A blood sample was obtained from each participant to determine the parasite index and the prevalence of antibodies against P. falciparum. The splenic index was also determined. A second assessment was performed for the school children six months later, using the same markers of malaria infection. Nine hundred and thirty two patients from the health center group were referred for participation in the study. This represented 10% of all patients and 74% of the patients with fever. The school group included 1,545 children. The splenic index was similarly low (0.5%) in the health center and school groups, as was the overall parasite index (2.6% for the health center group and 0.8% in the school group). The prevalence of antibodies against P. falciparum was also low, but with a seasonal variation: 2.5% in June 1995 and 11.6% in January 1996. Almost all the cases confirmed by parasitological examination were due to the patient having stayed in an area with hyperendemic malaria or having been in contact with an individual who had been to an area with a high level of transmission. Our findings confirm that Antananarivo is now in a post-epidemic situation. Malaria cases are mostly associated with a history of travel in areas with high levels of malaria transmission, particularly the coastal regions of Madagascar. Nevertheless, a low level of transmission may persist and lead to further outbreaks of malaria in the future, due to the presence in the area of Anopheles arabiensis.
Collapse
|
37
|
Przylipiak A, Hafner J, Przylipiak J, Runnebaum B, Rabe T, Köhn FM. Influence of leukotrienes on in vitro growth of human mammary carcinoma cell line MCF-7. Eur J Obstet Gynecol Reprod Biol 1998; 77:61-5. [PMID: 9550202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
OBJECTIVES The aim of this work was to study the action of leukotrienes on the growth of human mammary cancer cells MCF-7. STUDY DESIGN The growth of the cells was measured by incorporation of 3H-thymidine. The action of leukotriene (LT)B4, LTD4, LTC4, LTE4 or arachidonate (AA) was tested in human mammary cancer cells MCF-7 in vitro. RESULTS LTB4 or LTD4 but not LTC4 or LTE4 reduced significant incorporation of 3H-thymidine in MCF-7 cells up to 52% or 56% respectively, when administered in concentrations 0.1-1000 pM. Agents in concentrations of 0.01 pM or 10000 pM did not effect 3H-thymidine incorporation. We have shown, that MCF-7 cells synthesise LTB4 when treated with calcium ionophor A23187 (10 microM). Leukotriene-antagonist LY171883 (10 microM) lifts inhibitory effects of LTB4 or LTD4. Arachidonic acid (10 microM) inhibits 3H-thymidine incorporation up to 72%. 5-lipoxygenase inhibitor MK-886 (100 nM) lifts the inhibitory effect of arachidonate. CONCLUSIONS LTB4 or LTD4 inhibits MCF-7 breast cancer cell growth. LT-receptors mediate the growth-inhibitory effect of LTB4 or LTD4.
Collapse
|
38
|
Przylipiak A, Hafner J, Przylipiak J, Runnebaum B, Rabe T, Köhn FM. Influence of leukotrienes on in vitro growth of human mammary carcinoma cell line MCF-7. Eur J Obstet Gynecol Reprod Biol 1998. [DOI: 10.1016/s0301-2115(97)00217-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
|
39
|
Sillem M, Rabe T, Runnebaum B. Effect of central and ovarian endocrine disturbances on the female genital tract--clinical signs and symptoms. VERHANDLUNGEN DER DEUTSCHEN GESELLSCHAFT FUR PATHOLOGIE 1998; 81:191-6. [PMID: 9474869] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Disorders of the female genital tract caused by endocrine disturbances commonly lead to two presenting complaints: dysfunctional uterine bleeding and infertility. In oestrogen deficiency, sequelae of vaginal atrophy may also be present. The common pathogenic "turntable" of these clinical signs is an impaired ovarian function, for which primary (i.e. intraovarian) and secondary (i.e. resulting from dysfunctions of other endocrine systems) causes are known. Primary ovarian failure can be the result of gonadal dysgenesis or premature menopause. Secondary ovarian dysfunction may be caused by hypothalamic-pituitary dysregulation, hyperprolactinaemia, thyroid disorders, and hyperandrogenaemia, which often also has an intraovarian component. For clinical considerations, several severities of ovarian dysfunction can be distinguished, ranging from corpus luteum insufficiency which is only relevant for the selection of infertility treatment to the complete absence of ovarian steroidogenesis leading to severe long term sequelae of the skeletal, cardiovascular and probably central nervous systems. Diagnosis and differential diagnosis are made by clinical examination, vaginal ultrasound, hormone assays, curettage and laparoscopy. Rarely, additional techniques like magnetic resonance imaging of the pituitary or the adrenals, or sequential catheterization of the inferior vena cava are needed.
Collapse
|
40
|
Rabe T, Vladescu E, Runnebaum B. Die Zukunft der oralen hormonalen Kontrazeption. GYNAKOLOGE 1998. [DOI: 10.1007/s001290050286] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
|
41
|
Rabe T, Mueck AO, Deuringer FU, Vladescú E, Runnebaum B. Spacing-out of progestin--efficacy, tolerability and compliance of two regimens for hormonal replacement in the late postmenopause. Gynecol Endocrinol 1997; 11:383-92. [PMID: 9476087 DOI: 10.3109/09513599709152565] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Estrogen replacement therapy with sequential progestin at greater than monthly intervals has been frequently used in practice to reduce progestational side-effects and bleeding episodes, but clinical trials are still lacking. Two new regimens were tested. The main objective was to evaluate efficacy, predominantly in urogenital complaints, tolerability, and patient acceptance. Transdermal estradiol (0.05 mg/day) and norethisterone acetate orally (2.5 mg/day) were administered for 12 days every 2 or 3 months (group A, n = 83, group B, n = 89) to patients whose menopause had begun at least 4 years earlier. Study duration was three long cycles in each group within 7-10 months. Efficacy was good [group A/B = 94/92%], as was systemic tolerability [95/97%]; major skin reactions occurred in 7 and 4%, respectively. Patients' acceptance for continuation of spaced-out treatment was 88 and 87%, respectively. Progestin-associated withdrawal bleedings occurred in 66 (61%) of patients; mean duration 4.3 +/- 1.9/4.8 +/- 1.6 days, with no significant changes during therapy; intensity decreased during therapy. Breakthrough bleeding which required sonographic or histological work-up occurred in 8 and 13%, respectively. Despite the low dosage, transdermal estradiol proved to be efficacious in urogenital complaints. The high acceptance and the reduction of the overall progestin dose to avoid side-effects are of particular prognostic importance with regard to the prevention of cardiovascular diseases. Transdermal estradiol combined with 2- or 3-monthly progestin may be a valid regimen in the late post-menopause, but further studies using spacing-out regimens are urgently needed.
Collapse
|
42
|
Rabe T, Leppien G, Fossman WG, Hessing C, Vladescú E, Runnebaum B. A study of the influence of a gestodene-containing triphasic oral contraceptive on endometrial morphology. EUR J CONTRACEP REPR 1997; 2:193-201. [PMID: 9678092 DOI: 10.3109/13625189709167476] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
The objective of the study was to investigate histological changes in the endometrium in 20 volunteers treated with a low-dose, gestodene-containing triphasic oral contraceptive. Endometrial biopsy specimens were taken before, during a 6-month period of oral contraceptive use and in a post-treatment period. These specimens were evaluated using light microscopy, scanning and transmission electron microscopy. In addition, ultrasound examinations of the uterus, endometrial thickness and ovaries were performed. The low-dose, gestodene-containing triphasic oral contraceptive had no adverse effects on the endometrium (e.g. no proliferation, no polyps, no inflammatory processes), was well tolerated and showed a low side-effect profile. The inhibition of endometrial transformation was demonstrated both by endometrial morphology as well as by endometrial thickness, as measured by transvaginal ultrasound examination.
Collapse
|
43
|
Grunwald K, Feldmann K, Melsheimer P, Rabe T, Neulen J, Runnebaum B. O-172. Aneuploidy in human granulosa-lutein cells from gonadotrophin-stimulated follicles and their relationship to intrafollicular hormone concentrations. Hum Reprod 1997. [DOI: 10.1093/humrep/12.suppl_2.84] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
|
44
|
Rabe T, Przylipiak A, Kiesel L, Przylipiak J, Runnebaum B. Inhibitory effect of leukotrienes on luteinizing hormone release. Gynecol Endocrinol 1997; 11:149-53. [PMID: 9209894 DOI: 10.3109/09513599709152528] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
The aim of this work was to study the effect of high concentrations of leukotrienes on luteinizing hormone (LH) secretion in rat anterior pituitary cells. We also investigated the effect of leukotrienes in parallel with gonadotropin-releasing hormone (GnRH) action. Experiments were on cells gained from trypsinized pituitaries of female rats. Tests were performed by superfusion of the cells attached to cytodex-1 carrier beads. The LH content in samples of perfusate was estimated by radioimmunoassay. This work reports 48% inhibition of basic LH release by action of leukotriene C4 in superfused cells when applied continuously at a concentration of 100 nmol/l. Moreover, we have shown that leukotrienes suppressed GnRH-induced LH secretion in rat pituitary cells when applied in parallel to GnRH (1 nmol/l) as a 4-min pulse at a concentration of 0.1 nmol/l. GnRH-induced LH release was reduced to 66% of its value by leukotriene (LT) B4 (0.1 nmol/l) action; also to 54% by LTC4, 66% by LTD4 and 74% by LTE4 action. In contrast, arachidonic acid (50 pmol/l) and its other 5-lipoxygenase metabolites: 5-hydroperoxyeicosatetraenoic acid (5-HPETE) (50 pmol/l), or 5-hydroxyeicosatetraenoic acid (5-HETE) (50 pmol/l), had no inhibitory effect on GnRH-induced LH release. Arachidonic acid and 5-HETE potentiated GnRH-induced LH release up to 249% and 429%, respectively, when applied in parallel with GnRH (1 nmol/l) as a 4-min pulse at a concentration of 10 pmol/l. In our earlier work we have shown that several leukotrienes are potent stimulants of LH release. The present report documents the finding that the 5-lipoxygenase pathway is also involved in the inhibitory regulation of hormone release in anterior pituitary cells.
Collapse
|
45
|
Feldmann K, Rehberger S, Grunwald K, Rabe T, Fersis N, Runnebaum B. O-212. Inhibition of 5α-reductase activity in human skin by synthetic steroid hormones. Hum Reprod 1997. [DOI: 10.1093/humrep/12.suppl_2.105-a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
|
46
|
Sillem M, Prifti S, Schmidt M, Rabe T, Runnebaum B. Endometrial integrin expression is independent of estrogen or progestin treatment in vitro. Fertil Steril 1997; 67:877-82. [PMID: 9130893 DOI: 10.1016/s0015-0282(97)81400-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
OBJECTIVE To examine the regulation of endometrial integrin expression by estrogens and progestins in vitro. DESIGN Immunocytochemical study. SETTING Academic research unit. PATIENT(S) Twenty-five regularly cycling women without endometrial pathology, of whom seven had endometriosis. INTERVENTION(S) Endometrial cells obtained by aspiration curettage were treated with diethylstilbestrol, promegestone, and antiprogestin. Immunocytochemistry was performed with antibodies directed against integrins alpha 1 beta 1, alpha 2 beta 1, alpha 4 beta 1, alpha 5 beta 1, alpha v beta 3, and beta 3 integrin subunit. MAIN OUTCOME MEASURE(S) Semiquantitative staining score. RESULT(S) Endometrial cells express several integrins in vitro in a consistent and cell specific pattern. Neither differences between treated and untreated cells nor an effect of treatment duration or dosage were observed. Cells from patients with and without endometriosis showed similar patterns. CONCLUSION(S) The cellular distribution of integrin expression was similar to that described in vivo. In contrast, a steroid regulated expression could not be detected in vitro. Rather, a derepression by a factor not included in our model could be responsible for the cyclic appearance of some integrins. In endometriosis, no fundamental difference of integrin expression was detected.
Collapse
|
47
|
Rabe T, Nitsche DC, Runnebaum B. The effects of monophasic and triphasic oral contraceptives on ovarian function and endometrial thickness. EUR J CONTRACEP REPR 1997; 2:39-51. [PMID: 9678108 DOI: 10.1080/13625189709049933] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
OBJECTIVE To analyze and compare the effects of seven low-dose oral contraceptives (OCs) on ovarian function and endometrial thickness. METHODS Cross-sectional study of users of one of five monophasic OCs, one of two triphasic OCs and a control group of non-users. Ovarian function, endometrial thickness and serum hormone levels were monitored during days 10-12 and 16-18 of the cycle. RESULTS Serum estradiol was suppressed in OC users to a greater degree during days 16-18 than during days 10-12, whereas serum progesterone during 16-18 was in the anovulatory range with each preparation. Ovarian activity as measured by follicular size was lowest with desogestrel-containing OCs, whereas greater activity was seen with triphasic levonorgestrel/ethinylestradiol and triphasic norgestimate/ethinylestradiol. Endometrial thickness in OC users was significantly smaller than in controls. CONCLUSIONS All preparations demonstrated profound suppression of ovarian activity and effectively prevented ovulation. Ovarian suppression with desogestrel/ethinylestradiol 150/20 did not differ from that of other OCs despite its lower ethinylestradiol content. The use of both triphasic OCs, having a relatively low progestogenic activity, was associated with a higher ovarian activity than that of the monophasic OCs.
Collapse
|
48
|
Rabe T, van Staden J. Antibacterial activity of South African plants used for medicinal purposes. JOURNAL OF ETHNOPHARMACOLOGY 1997; 56:81-87. [PMID: 9147258 DOI: 10.1016/s0378-8741(96)01515-2] [Citation(s) in RCA: 178] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Crude extracts from 21 South African medicinal plants, traditionally used for ailments of an infectious or septic nature, were screened for in vitro antibacterial activity using the agar diffusion and dilution methods. Almost all the activity exhibited was against Gram-positive bacteria, with 12 of the 21 plant species tested showing some activity against Bacillus subtilis. Only the Warburgia salutaris methanol extract inhibited the growth of Escherichia coli. None of the extracts had any activity against Klebsiella pneumoniae. The highest activity was found in the methanol extracts from Bidens pilosa, Psidium guajava, Artemisia afra and Warburgia salutaris. The majority of the antibacterial activity was present in the methanolic, rather than the aqueous extracts.
Collapse
|
49
|
Melsheimer P, Grunwald K, Feldmann K, Rabe T, Runnebaum B, Rummel HH. Aneuploidy of human granulosa cells in follicular fluids from in vitro fertilization patients. ANALYTICAL AND QUANTITATIVE CYTOLOGY AND HISTOLOGY 1997; 19:75-79. [PMID: 9051189] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
OBJECTIVES To study the proliferative behavior of granulosa cells found in follicular fluids from patients after hormone stimulation in the framework of in vitro fertilization (IVF) with gonadotropins. STUDY DESIGN The deoxyribonucleic acid ploidy and the proliferation indices of granulosa cells in fresh and unfixed follicles (n = 119) from gonadotropin-stimulated patients (n = 32) were analyzed by flow cytometry. RESULTS Aneuploid cells were found in a large number of follicles (65/119) as well as patients (25/32). A small number of follicles (8/119) and patients (7/32) contained multiploid cells. There was no correlation between proliferation indices and ploidy. Granulosa cells were the predominant cells in follicular fluids. No malignant cells were found in any case. CONCLUSION This is the first report concerning the high incidence rate of aneuploidy in ovarian granulosa cells in IVF patients. The clinical relevance of the phenomenon is not clear. There should be further study to determine whether there is any link to a previously discussed possible relation between gonadotropin stimulation in women attempting to become pregnant and the occurrence of ovarian cancer or granulosa cell tumors. Of further interest might be a possible relation between ploidy and proliferation indices of stimulated granulosa cells as well as side effects of gonadotropin therapy and biologic parameters, like maturity, fertilizability of oocytes and rates of pregnancy.
Collapse
|
50
|
Rabe T, Przylipiak A, Müller H, Przylipiak J, Runnebaum B. Action of vasopressin in superfused human granulosa cells in vitro. Gynecol Endocrinol 1996; 10:371-4. [PMID: 9032562 DOI: 10.3109/09513599609023599] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Arginine-vasopressin as well as luteinizing hormone (LH)/follicle-stimulating hormone (FSH) stimulate progesterone release in superfused human granulosa cells. Extracellular administration of inositol triphosphate (10(-6) mol/l) or calcium ions (10(-4) mol/l) mimics the action of both arginine-vasopressin and LH/FSH and evokes progesterone secretion in superfused granulosa cells.
Collapse
|