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Biomedical subjects

M Korhonen

Publications and source records attributed to M Korhonen.

53 records · Page 3Linked to original sources
PubMed1984

GnRH agonist-induced inhibitory and stimulatory effects during ovarian follicular maturation.

The in vivo regulation of ovarian gonadotropin and prolactin receptors and adenylate cyclase activity by FSH, and the potent GnRH agonist [D-Ala6]des-Gly10-GnRH N-ethylamide (GnRHa), was studied in immature hypophysectomized diethylstilbestrol-implanted rats. During FSH treatment over a 48 h period, FSH receptors increased 2-fold with the maximum response during the first 12 h, whereas LH and prolactin receptors increased by 10-fold and 6-fold with the maximum response from 12 to 48 h. Administration of GnRHa at any time during the 48 h period of FSH treatment inhibited the subsequent development of gonadotropin and PRL receptors. In contrast, administration of a single dose of 10 micrograms GnRHa after 48 h of FSH treatment stimulated follicular luteinization and caused increases in basal adenylate cyclase activity, ovarian weight and PRL receptor content, and concomitant decreases in gonadotropin receptors and adenylate cyclase responses. In the immature follicles of animals not primed with FSH, GnRHa caused progressive inhibition of FSH-sensitive adenylate cyclase activity, with a decrease in FSH receptors, but increased both basal and GMP-P(NH)P-stimulated adenylate cyclase activities. These results demonstrate that GnRHa causes marked inhibition of gonadotropin receptor expression in the basal and FSH-stimulated ovary. This decrease in gonadotropin receptors is an important component of the mechanism by which GnRH agonists inhibit ovarian gonadotropin-sensitive adenylate cyclase activity. In addition, these peptides exert stimulatory effects upon ovarian weight and basal adenylate cyclase activity, and cause an increase in PRL receptors and luteinization of mature ovarian follicles.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenylyl Cyclases↗
PubMed1984

Adenocarcinoma metastatic to the uterine cervix.

In this study 208 patients with adenocarcinoma of the uterine cervix were examined for the occurrence of tumors metastatic to this location. A total of 45 secondary tumors were found, 31 with a primary endometrial tumor, 6 with an ovarian serous or mucinous adenocarcinoma, 2 tubal tumors, 5 colonic adenocarcinomas, and 1 primary mammary tumor. Clinical and morphological aspects were studied, indicating the need for consideration of metastatic tumors as explanation for suspected neoplastic cervical lesions.

Adenocarcinoma↗
PubMed1983

Inhibitory actions of a gonadotropin-releasing hormone agonist on ovarian follicle-stimulating hormone receptors and adenylate cyclase in vivo.

The regulation of ovarian gonadotropin-sensitive adenylate cyclase and FSH receptors was studied in hypophysectomized diethylstilbestrol-primed rats treated with FSH and/or the potent GnRH agonist [D-Ala6]des-Gly10-GnRH N-ethylamide (GnRHa). The animals were treated with 7.5 micrograms ovine FSH twice daily for 2 days, either alone or with 10 micrograms GnRHa. FSH-stimulated adenylate cyclase activity was augmented by 2.5- to 3.5-fold in the presence of 5'-guanyl-imidodiphosphate. Adenylate cyclase responses to FSH were almost completely abolished by GnRHa treatment in ovarian homogenates from control animals and rats treated with FSH. This inhibition was receptor specific, since GnRHa did not block adenylate cyclase stimulation by prostaglandin E2 or isoproterenol. No inhibition of 5'-guanyl-imidodiphosphate- or sodium fluoride-stimulated adenylate cyclase activity was noted after any hormone treatment. When GnRHa treatment was initiated at 12, 24, or 36 h during the 2-day period of FSH treatment, inhibition of both FSH- and LH-stimulated adenylate cyclase was observed in ovaries collected at 48 h. Whereas FSH treatment increased the ovarian FSH receptor concentration by more than 100%, concomitant treatment with GnRHa prevented this increase and reduced FSH receptors to 60% of the control level. Treatment with GnRHa alone caused a 65% decrease in FSH receptor levels below the untreated control values. Histological analysis of hormone-treated ovaries indicated that FSH stimulated follicle growth and antrum formation, but caused little luteinization. GnRHa did not completely prevent the effects of FSH on follicle growth, but did induce degeneration and premature cleavage of ova. GnRHa alone suppressed the diethylstilbestrol-stimulated mitotic activity, slightly increased degenerative changes in granulosa cells, and caused oocyte cleavage and premature antrum formation. These findings demonstrate that GnRHa inhibits FSH-dependent adenylate cyclase by a mechanism involving the loss of binding sites for FSH. It is also evident that only short term exposure to GnRHa is necessary for expression of the inhibitory action of the peptide upon FSH- and LH-stimulated adenylate cyclase.

Adenylyl Cyclases↗
PubMed1981

Reduction of venous sequelae of i.v. diazepam with a fat emulsion as solvent.

Venous sequelae were studied in 93 female patients undergoing minor gynaecological procedures. They were premedicated with diazepam i. v. dissolved in a fat emulsion (Diazemuls) injected to a superficial vein of the right hand. The patients observed the site of injection for 14 days and recorded their findings. Twenty-eight per cent reported mild tenderness and 7.5% mild or moderate swelling of short duration. Signs of thrombophlebitis were found in 2.2%. Thrombophlebitis after injection can be prevented effectively and safely using fat emulsion as a solvent for diazepam.

Adolescent↗
PubMed1979

Distinction between endocervical and endometrial adenocarcinoma with immunoperoxidase staining of carcinoembryonic antigen in routine histological tissue specimens.

The differential diagnosis of endocervical and endometrial adenocarcinomas can be improved by the demonstration of carcinoembryonic antigen (CEA) in tissue by means of immunoperoxidase staining. Tissue from 131 (80%) of 163 patients with endocervical adenocarcinoma but only 11 (8%) of 137 patients with endometrial adenocarcinoma was CEA-positive. The commonest exceptions were endocervical mesonephroid adenocarcinomas (which were CEA-negative) and endometrial adenosquamous carcinomas (which were CEA-positive). After exclusion of these on simple morphological criteria, 86 of 107 endocervical adenocarcinomas (80%) were CEA-positive, and all 122 endometrial adenocarcinomas were CEA-negative. The remarkable difference in the expression of CEA between endocervical and endometrial adenocarcinomas suggests a novel application of immunohistochemistry in routine clinical practice.

Adenocarcinoma↗
PubMed1979

Prevention of diazepam-induced thrombophlebitis with cremophor as a solvent.

In 104 patients undergoing anaesthesia of short duration, two different solvents, propylene glycol and cremophor, were compared in a double-blind trial. Diazepam 10 mg in a coded solution was injected into a superficial vein of the hand using a small-gauge needle. The vein was examined after 14 days. The frequency of thrombophlebitis with propylene glycol was 62.2% and with cremophor 3.4% (P less than 0.001). The frequency of pain on injection was also in favour of the new solvent (P less than 0.001). The possibility of anaphylactic reactions accredited to cremophor, however, restricts the use of the new injection.

Adolescent↗
PubMed1978

Investigation of gynecological cancer with nuclear magnetic relaxation methods.

Nuclear magnetic relaxation times T1 and T2 of cell water protons in benign and malignant uterine cervical tissue (37 samples taken from 22 patients) were measured using a resonance frequency of 19.8 MHz. The means of relaxation times recorded for malignant tissue were (mean +/- S.E.) T1 = 0.89 +/- 0.05 s, T2 = 0.072 +/- 0.009 s, and obtained from corresponding benign tissues (mean +/- S.E.) T1 = 0.72 +/- 0.01 s T2 = 0.056 +/- 0.003 s. The differences are statistically significant (T1:p less than 0.001, and T2:p less than 0.05). The effect of dysplasia and inflammatory changes in mucosa to the relaxation times were examined and the probable sources of error in the present method are discussed.

Carcinoma↗
PubMed1975

Relationship between endometrial Arias-Stella phenomenon and concentrations of urinary chorionic gonadotropin and serum human placental lactogen.

Serum placental lactogen (HPL) and urinary chorionic gonadotrophin (HCG) were measured in 14 patients with the endometrial Arias-Stella phenomenon and in 35 comparable patients without this reaction in order to explore a possible causative relationship between the hormonal levels and the endometrial changes. The concentrations of HPL and HCG were similar in both groups of patients, indicating a lack of correlation between the levels of these two hormones and endometrial changes.

Chorionic Gonadotropin↗
PubMedDate not supplied

Concentrations of polychlorinated dibenzo-p-dioxins and furans in fish downstream from a Ky-5 manufacturing.

Concentrations of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) were studied in seven fish species, burbot (Lota lota), pike (Esox lucius), perch (Perca fluviatilis), pikeperch (Stizopedion lucioperca), bream (Abramis brama), salmon (Salmo salar) and Baltic herring (Clupea harengus membras) in River Kymijoki and its estuary polluted by Ky-5 manufacturing. The fish were caught at 14 localities along the river and its estuary. The selected species represent different trophic levels and/or inhabit different environments. The concentrations of PCDD/Fs were low, in most samples below 1 pg g(-1) ITEQ (NATO/CCMS 1988) fresh weight (fw) in muscle, except salmon and Baltic herring. These two species graze at the open sea and consequently accumulate contaminants at a large area in the Baltic Sea. The lipid content in salmon and Baltic herring was an order of magnitude higher than in other species. PCDD/Fs in fish muscle showed only slightly elevated levels in the Kymijoki area and its estuary as compared to the levels in the same species in Finnish freshwaters and sea areas. The concentration of the main impurities of the fungicide Ky-5 was higher in the Kymijoki River downstream the Ky-5 manufacturing place compared to the up-stream locations. The PCDD/F concentrations in fish liver and spawn were 10-100 times higher than the concentration in muscle, because of the much higher lipid concentrations of these organes. Consequently, the tolerable daily intake values could be as much as 100 times smaller (M. Korhonen, M. Verta, T. Vartiainen, Organohalog. Comp. 32 (1997) 305-310; P. Mikkelson, J. Paasivirta, H. Kiviranta, Organohalog. Comp. 39 (1998) 59-62).

Animals↗