Exacerbation of influenzavirus pneumonia by intranasal administration of surfactant in a mouse model

Although surfactant-secreting type II alveolar cells have been shown to be damaged during influenzavirus pneumonia, little is known about the effects of surfactant replacement therapy. We have developed a mouse influenza model, in which viral infection can be localized to the upper respiratory tract or to both the upper and lower respiratory tract depending on the volume (rather than infectious dose) of intranasal inocula of influenzavirus. In this model, only mice infected with a large inocula die with massive infection in the lung. Using this model, we unexpectedly found that intranasal administration of surfactant dramatically exacerbated influenzavirus infection causing fatal disease even in mice inoculated with a small inocula. This exacerbation resulted from enhancement of intrabronchial and intraalveolar spread of virus, as confirmed by immunohistochemical detection of viral antigen in lungs. Assuming this experimental model in mice recapitulates naturally occurring disease in humans, extreme caution is warranted in surfactant-replacement treatment of influenzavirus pneumonia in humans.

Trichromatic Concept at SPring-8 RIKEN Beamline I

SPring-8 RIKEN beamline I has been designed and developed for structural biology research by the Institute of Physical and Chemical Research (RIKEN). The beamline consists of two experimental stations for protein crystallography and small-angle X-ray scattering. Both types of experiments can be carried out simultaneously, with dichromatic synchrotron radiation emitted from two coaxial undulators with vertical polarization. The branched beams are generated by a transparent diamond crystal. With synchrotron radiation, the multiple-wavelength anomalous-dispersion (MAD) method, which gives phases from a single anomalous scatterer, has been developed. Anomalous scattering contributes a small proportion of the diffraction intensity so that the accuracy of intensity data is important. The protein crystallography branch of RIKEN beamline I has been designed based on a 'trichromatic concept' to optimize MAD data collection. This concept requires the quasi-simultaneous collection, by use of a 'trichromator', of three intensity data sets at three different wavelengths from a single protein crystal without changing any settings. The main feature of the concept is the minimization of systematic errors in the measurement of anomalous diffraction for the MAD method. Initial commissioning of the beamline has provided three different monochromated undulator beams, which were successfully observed on the phosphor screen located at the near end of the trichromator.

Neutrophil emigration in the lungs

Neutrophil emigration into the lung occurs in response to inflammatory mediators in the interstitium and the airspace. Emigration through the pulmonary microvasculature occurs through two pathways, one that requires CD11/CD18 and ICAM-1 and one that does not: Which pathway is utilized is determined by the stimulus. The ability of a stimulus to upregulate ICAM-1 by inducing the production of pro-inflammatory cytokines including TNF-alpha appears to determine the selection of the CD11/CD18, ICAM-1, ICAM-1-dependent pathway Recently, a third pathway has been identified that requires CD11/CD18 but not ICAM-1. The ligand for this pathway, as well as the ligands for CD11/CD18, ICAM-1-independent adhesion have not been identified. During recurrent pneumonia, the adhesion molecules required for emigration are different than those utilize during acute inflammation in previously normal lung tissue. For example, studies investigating the role of CD11/CD18 in recurrent pneumonia induced by P. aeruginosa, a stimulus which elicits CD11/CD18-dependent emigration initially, showed that when the organisms are instilled at the same site 7 days after the initial instillation, most emigration occurs through CD11/CD18-independent mechanisms. These studies suggest that when an acute stimulus is placed at a site of resolving inflammation, new pathways of adhesion are recruited. Whether these molecules are the same ones mediating acute CD11/CD18-independent adhesion remains to be determined. In summary, neutrophil emigration in the lung can occur through several adhesion pathways, which pathway is utilized can change during the inflammatory process, and cytokines participate in the selection of the pathway.

Regional comparison of prolactin gene expression in the human decidualized endometrium in early and term pregnancy

Prolactin (PRL) is known to be expressed in the decidualized human endometrium and secreted into amniotic fluid. Although the site of synthesis of endometrial PRL is known to be the decidual cells, the difference in PRL gene expression within each area of decidua, i.e. decidua basalis, decidua parietalis and decidua capsularis, during pregnancy is not clear. We have applied an in situ hybridization histochemistry technique using a radiolabeled RNA probe to compare the difference in expression of PRL gene within each area of the decidualized endometrium. Specific hybridization signals were distributed over the decidual cells in early and term pregnancy. More intense hybridization signals were always detected in the tissues of early pregnancy than in those of term pregnancy. In the decidua capsularis of early pregnancy, labeled cells were concentrated close to the amniotic cavity, whereas cells were concentrated close to the maternal surface of the fetal membrane in term pregnancy. In the decidua parietalis, almost all decidual cells were labeled, but no specific labeling was seen in the endometrial glands or capillary endothelium in both groups. In the decidua basalis, most decidual cells showed hybridization signals whereas no hybridization signal was seen over the trophoblast cells. These results show that there are regional and periodic differences in PRL gene expression in the decidual cells during pregnancy.

ATP-activated nonselective cation current in NG108-15 cells

ATP (1 mM) induced a biphasic increase in intracellular Ca2+ concentration ([Ca2+]i), i.e., an initial transient increase decayed to a level of sustained increase, in NG108-15 cells. The transient increase was inhibited by a phospholipase C inhibitor, 1-[6[[17beta-3-methoxyestra-1,3,5(10)-trien-17-yl]amino]hexyl]-1H- pyrrole-2,5-dione (U73122), whereas the sustained increase was abolished by removal of external Ca2+. We examined the mechanism of the ATP-elicited sustained [Ca2+]i increase using the fura-2 fluorescent method and the whole-cell patch clamp technique. ATP (1 mM) induced a membrane current with the reversal potential of 12.5 +/- 0.8 mV (n = 10) in Tyrode external solution. The EC50 of ATP was approximately 0.75 mM. The permeability ratio of various cations carrying this current was Na+ (defined as 1) > Li+ (0.92 +/- 0.01; n = 5) > K+ (0.89 +/- 0.03; n = 6) > Rb+ (0.55 +/- 0.02; n = 6) > Cs+ (0.51 +/- 0.01; n = 5) > Ca2+ (0.22 +/- 0.03; n = 3) > N-methyl-D-glucamine (0.13 +/- 0.01; n = 5), suggesting that ATP activated a nonselective cation current. The ATP-induced current was larger at lower concentrations of external Mg2+. ATP analogues that induced the current were 2-methylthio-ATP (2MeSATP), benzoylbenzoic-ATP, adenosine 5'-thiotriphosphate (ATPgammaS), and adenosine 5'-O-(2-thiodiphosphate), but not adenosine, ADP, alpha,beta-methylene-ATP (AMPCPP), beta,gamma-methylene-ATP (AMPPCP), or UTP. Concomitant with the current data, 2MeSATP and ATPgammaS, but not AMPCPP or AMPPCP, increased the sustained [Ca2+]i increase. We conclude that ATP activates a class of Ca2+-permeable nonselective cation channels via the P2z receptor in NG108-15 cells.

Role of the intercellular adhesion molecule-1(ICAM-1) in endotoxin-induced pneumonia evaluated using ICAM-1 antisense oligonucleotides, anti-ICAM-1 monoclonal antibodies, and ICAM-1 mutant mice

This study examined the effectiveness of antisense oligonucleotides targeted to intercellular adhesion molecule-1 (ICAM-1) to inhibit endotoxin-induced upregulation of ICAM-1 and neutrophil emigration and compared the apparent role of ICAM-1 when examined using antisense oligonucleotides, anti-ICAM-1 antibodies, and ICAM-1 mutant mice. Antisense oligonucleotides inhibited upregulation of ICAM-1 mRNA at 4 and 24 h after instillation of endotoxin in a dose-dependent manner. Neutrophil emigration into the alveolar spaces at 24 h was inhibited by 59%, similar to inhibition using the anti-ICAM-1 antibodies 3E2 (58%) and YN1/1 (75%). No inhibition was observed in the ICAM-1 mutant compared to wild-type mice. These data show that antisense oligonucleotides targeted to ICAM-1 inhibit the endotoxin-induced upregulation of ICAM-1 in the lung and are as effective as anti-ICAM-1 antibodies in preventing neutrophil emigration. The incomplete inhibition by either antisense oligonucleotides or antibodies suggests that alternative adhesion pathways that do not require ICAM-1 are important in neutrophil emigration in the lungs. The disparity in the role of ICAM-1 when evaluated using antisense or antibodies compared to mutant mice suggests that either these inhibitors are exerting additional effects on endothelial cells other than blockade of ICAM-1 or mutant mice have upregulated the ICAM-1-independent pathways to compensate for the long-term loss of ICAM-1.

Role of CD 11/CD 18 in neutrophil emigration during acute and recurrent Pseudomonas aeruginosa-induced pneumonia in rabbits

This study examined CD11/CD18-mediated adhesion in neutrophil emigration during acute and recurrent Pseudomonas aeruginosa-induced pneumonia. Neutrophil emigration during acute pneumonia was studied in anti-CD18 antibody or murine-IgG-pretreated rabbits 4 hours after intrabronchial instillation of P. aeruginosa. To examine emigration in recurrent pneumonias, rabbits given P. aeruginosa on day 0 received anti-CD18 antibody or IgG on day 7. A second instillate was placed either at the initial site or in a separate lobe, and emigration into alveolar spaces was quantitated morphometrically after 4 hours. The results show that CD11/CD18 was required for neutrophil emigration in acute pneumonias and in recurrent pneumonias that occurred at a site distant from the initial infection. However, when the recurrent pneumonia occurred in the previously inflamed site, CD11/CD18 was not required. When the same number of organisms were instilled on days 0 and 7, emigration was reduced to 15 to 20 percent of the number that migrated initially and only CD18-independent adhesion pathways were used. Increasing the concentration of organisms threefold increased emigration through both CD18-dependent and CD18-independent pathways. These data indicate that P. aeruginosa induces CD11/CD18-dependent emigration during acute pneumonia and recurrent pneumonia at previously uninflamed sites. However, adhesion pathways are altered in regions of chronic inflammation, and a greater proportion of neutrophil emigration occurs through CD11/CD18-independent pathways.

Crystal structure of H2-proteinase from the venom of Trimeresurus flavoviridis

The crystal structure of the zinc-protease, H2-proteinase, isolated from the venom of Trimeresurus flavoviridis has been determined. The crystallographic R factor is 0.176 for 10,635 reflections with Fobs > 2sigma(Fobs) in the 8.0 to 2.2 Angstrom resolution range. The enzyme has two domains with a cleft in which a catalytic zinc atom is located. The N-terminal domain is composed of four helices around a central five-stranded beta-sheet. The irregularly folded C-terminal domain contains one helix and two disulfide bridges. These two domains are linked by a disulfide bridge. In the zinc environment, the catalytic zinc atom forms a distorted tetrahedral coordination with three histidines and one catalytic water molecule, and the methionine-containing turn is structurally conserved. These are distinctive features of the metzincins, one of the zinc metalloprotease superfamilies. The entire structure shows good agreement with that of two Crotalus snake venom proteases, adamalysin II and atrolysin C. The H2-proteinase, however, contains no structural calcium ions, and differences of disulfide configurations and the coordination of the catalytic water molecule exist as compared with the other two proteases.

Localization of prolactin and its receptor messenger RNA in the human decidua

Prolactin (PRL) is known as an anterior pituitary hormone. On the other hand, PRL is also produced in the human decidualized endometrium. The physiological role and site of action of endometrial PRL have not yet been clarified. This study was designed to investigate the localization of PRL receptor (PRL-R) gene-expressing cells in the human decidualized endometrium using in situ hybridization histochemistry. Sense and antisense 35S-labeled RNA probes for human PRL-R mRNA were hybridized with cryostat sections of human decidua, which were obtained from patients undergoing therapeutic abortion at 8-10 weeks of gestation. Hybridization signals for PRL-R mRNA were seen over the decidual cells. No labeled cells were seen in the chorion, amnion, or trophoblast. Comparing the localization of PRL-R gene-expressing cells to that of PRL gene-expressing cells using adjacent sections, their distributions were quite similar. These results indicate that not only PRL but also PRL-R transcripts are located in the decidual cells.

Expression of prolactin gene in human decidua during pregnancy studied by in situ hybridization histochemistry

The prolactin (PRL) gene is known to be expressed not only in the anterior pituitary but also in the decidualized human endometrium. This study was designed to detect the site of synthesis of PRL during pregnancy by in situ hybridization histochemistry. Decidual and trophoblast tissues from early pregnancy were obtained from patients undergoing therapeutic abortion at 8-10 weeks of gestation. Term placentae were obtained from patients with uncomplicated deliveries at 38-40 weeks. Sections of these tissues were hybridized with 35S-labeled RNA probe complementary to human PRL mRNA. Specific hybridization signals were distributed over the decidual cells in early and term pregnancy. In the decidua capsularis of early pregnancy, labeled cells were concentrated close to the amniotic cavity, although decidual cells were distributed evenly. In the decidua parietalis, almost all decidual cells were labeled, but no specific labeling was seen in the endometrial glands or capillary endothelium. In the decidua basalis, greater signals were always detected over the decidual cells in early pregnancy than in term pregnancy, when sections, which were hybridized with the same probe and exposed simultaneously, were compared. No specific hybridization was detected in the trophoblast cells. These results not only confirm that PRL is specifically synthesized in the decidual cells but also indicate that there are regional and periodical differences in PRL gene expression in the decidual cells during pregnancy.

Crystallization and preliminary X-ray study of H2-proteinase from the venom of Trimeresurus flavoviridis

H2-proteinase, a non-hemorrhagic metalloproteinase from the venom of Trimeresurus flavoviridis, has been crystallized by vapor diffusion from solutions containing ammonium sulfate. The crystals belong to the tetragonal space group, P41212 or P43212, with unit cell dimensions of a = b = 77.8 A and c = 82.3 A. The asymmetric unit contains one protein molecule. Diffraction data for a native crystal were collected up to 2.0 A resolution.

[Expression of prolactin gene in human decidua]

This study was designed to detect the localization of prolactin gene expressing cells in the human utero-placental unit during pregnancy.

METHODS

Human endometrium was obtained at hysterectomy from normally cycling women who underwent surgery for myoma uteri. Decidual and trophoblast tissues from early pregnancy were obtained by curettage from patients undergoing therapeutic abortion at 8-10 weeks of gestation. Term placenta was obtained from patients with uncomplicated deliveries at 38-40 weeks. Total RNAs of these tissues were extracted to perform Northern blot hybridization (NBH) with the radiolabelled human pituitary prolactin cDNA probe. Frozen sections of these tissues were cut and processed for in situ hybridization (ISH) with the radiolabelled RNA probe complementary for human prolactin mRNA.

RESULTS

1. By NBH, approximately a 1.3 kilobase (kb) size band was detected in the total RNA obtained from late secretory endometrium (day 26), decidua of early pregnancy and placenta of term pregnancy, and the decidua had the most significant signal. No hybridization signal was detected in the chorionic villi in early pregnancy. 2. By ISH, a significant hybridization signal was detected in the cytoplasm of the decidual cells in early and term pregnancy. No hybridization signal was detected in the endometrial grandsand trophoblast cells.

CONCLUSION

These results indicate that prolactin is synthesized in the decidual cells in the human uterus during pregnancy.

Effects of various forms of progestin on the endometrium of the estrogen-primed, ovariectomized rat

Progestin supplementation has been advocated in estrogen treatment for postmenopausal women to avoid proliferation of the endometrium. In this study we investigated the morphologic and biochemical effects of progestins on the endometrium of estrogen primed, ovariectomized rats. As the progestin derivatives, Allylestenol (AE), Norethisterone (NE), Danazol (DZ), Dydrogesterone (DG), Medroxyprogesterone acetate (MPA) and Cyproterone acetate (CPA), and as a anti-estrogen compound, Tamoxifen (TMX), were applied. To evaluate the effects of these different compounds on the endometrium, histologic studies and measurement of estrogen receptor concentrations were performed. When 19-nortestosterone groups, AE, DZ and NE, were orally administered to the conjugated equine estrogen (CE) treated, ovariectomized rats, the histologic pattern of the endometrium revealed rather a marked inhibition of hyperplasia induced by CE than a progestational response. Two of 3 of 17 alpha-hydroxyprogesterone groups, DG and MPA, provided slightly endometrial protection against the hyperplastic response, but another one, CPA, did not have any inhibitory effect on the estrogenic stimulation of the endometrium. TMX was not capable of suppressing the endometrial hyperplasia caused by CE administration. The average plasma concentrations of estradiol (E2) were 82.0 +/- 27.0 pg/ml (Mean +/- SD) after CE administration and there were no significant differences among these groups. Estrogen receptor concentrations of endometrium of progestins or antiestrogen added groups were not changed, when compared with the CE alone group. There was also no relationship between the estrogen receptor concentrations and the histologic findings in the endometrium. This discrepancy may be chiefly due to the low dose of the progestins as compared with the CE dose.(ABSTRACT TRUNCATED AT 250 WORDS)

[Urethral condyloma acuminatum with severe dysplasia in a male patient detected human papillomavirus type 11: a case report]

We report a case of urethral condyloma acuminatum with severe dysplasia detected human papillomavirus (HPV) type 11. A 47-year-old male patient visited St. Luke's International Hospital complaining of tumor at the urethral meatus. One small papillary lesion was found and excised. Histopathological examination revealed condyloma acuminatum with severe dysplasia. Immunohistochemical detection for HPV antigen in the specimen of condyloma acuminatum was positive and that of severe dysplasia was negative. In an electron microscopical study, viral particles were demonstrated only in the specimen of condyloma acuminatum. Detection of HPV DNA was performed using in situ hybridization (ISH) and southern blot hybridization (SBH). HPV type 11 was found in both lesions. In conclusion, although previous studies have shown that HPV type 16/18 was especially correlated with genital severe dysplasia and carcinoma, the process of malignant transformation was suggested in the association with HPV type 11.

[Hodgkin's disease associated with Behçet's disease]

This paper reports a rare case of Hodgkin's disease with Sjögren syndrome in the course of Behçet's disease. A 43-year-old man developed arthralgia of bilateral knees, ankles, elbows and wrists in May, 1988. He had hazy vision and was diagnosed as having iridocyclitis and chorioretinitis in February, 1989. Gingival ulcer, penile ulcer, erythema nodosum on the right lower leg and superficial thrombophlebitis on the bilateral arms appeared in June, 1989. Therefore, he was diagnosed as Behçet's disease. He responded well to prednisolone. In November, 1989, he developed fever with positive CRP and elevated alkaline phosphatase. Multiple mass lesions in the liver and spleen with retrocrural lymphadenopathy were noticed on the abdominal CT and echogram. A cervical lymph node biopsy revealed Hodgkin's disease of the mixed cellularity type. At the same time, the patient had dry eyes and a dry mouth. Salivary gland biopsy revealed chronic sialoadenitis with lymphocytic infiltration compatible with Sjögren syndrome. The patient responded well to ABVD regimen. He is still free of disease as of May, 1991.

Possible roles of arachidonic acid and its metabolites in induction of tissue plasminogen activator (t-PA) production in human fibroblast, IMR-90 cells by proteose peptone

Proteose peptone (p.peptone) had an ability to induce tissue plasminogen activator (t-PA) production by human embryonic lung fibroblast, IMR-90 cells. We previously demonstrated that the induction was closely related to the activation of phospholipase A2 in the cells stimulated by p.peptone. In this report, we describe the involvement of arachidonate metabolism in the induction. The induction was inhibited in a dose-dependent manner by 5,8,11,14-eicosatetraenoic acid (ETYA), an inhibitor of both cycloxygenase and lypoxygenase, and also by nordihydroguaiaretic acid (NDGA), which in low concentrations selectively inhibits lipoxygenase. However, indomethacin, a specific inhibitor of cycloxygenase, had no effect on the induction. 5-hydroxyeicosatetraenoic acid (5-HETE), which is an arachidonate metabolite derived from lipoxygenase pathway, had an inductive effect, but prostaglandin E1 (PGE1), which is a metabolite from cycloxygenase pathway, had no effect on t-PA production by the cells. These results suggest that arachidonate metabolism is involved in the induction of t-PA production in IMR-90 cells by p.peptone, and that arachidonate metabolite(s) from lipoxygenase pathway is responsible for the induction.

Participation of phospholipase A2 in induction of tissue plasminogen activator (t-PA) production by human fibroblast, IMR-90 cells, stimulated by proteose peptone

Proteose peptone (p.peptone) had an ability to induce tissue plasminogen activator(t-PA) production by human embryonic lung fibroblast, IMR-90 cells. The induction was dependent on extracellular Ca2+ concentration. The stimulation of p.peptone caused uptake of 45Ca2+ by the cells. The presences of both p.peptone and Ca2+ in medium were necessary for the continuous induction of t-PA production. Hydrocortisone and dexamethasone inhibited t-PA production induced by p.peptone. In addition, the inhibitors of phospholipase A2, quinacrine and 4-bromophenacylbromide, respectively inhibited t-PA production as well as glucocorticoids. Conversely, melittin, an activator of phospholipase A2, induced t-PA production in a dose-dependent manner. Exogenous phospholipase A2 strongly induced t-PA production and also arachidonic acid moderately did in a dose-dependent manner. P.peptone stimulated the release of radioactive arachidonic acid from 3H-arachidonic acid-labeled IMR-90 cells under the presence of Ca2+. These results suggest that the induction of t-PA production by p.peptone is closely related to the activity of phospholipase A2, that is, the release of arachidonic acid from phospholipids in cell membrane.

[Contractile responsiveness of the isolated guinea pig oviduct to autacoids at different phases of the sexual cycle or under ovarian steroid treatment]

Contraction of the longitudinal smooth muscle of the isolated guinea pig oviduct in response to autacoids was examined at different phases of the sex cycle or during ovarian steroid treatments. Isolated strips from isthmic smooth muscle of the female guinea pig (body weight; 300-900 g) oviduct were mounted in an organ bath and their isotonic responses were measured in the longitudinal direction. Histamine (greater than or equal to 3 X 10(-8) M) produced a concentration-dependent contraction of the oviductal smooth muscle, which was unaffected by the sex cycle. Noradrenaline and adrenaline (greater than or equal to 10(-8) M) produced a contraction mediated by alpha-adrenoceptors and a relaxation mediated by beta-adrenoceptor. During proestrus and metestrus (high estrogen), the contractile response was reduced but relaxation was increased, compared with those observed during diestrus. Prostaglandin E2 and F2 alpha (greater than or equal to 10(-10)M and greater than or equal to 10(-9)M, respectively) produced a concentration-dependent contraction and their maximum responses were about 50% of that induced by histamine (10(-4)M). These contractile responses were unaffected by the sex cycle. On the other hand, acetylcholine did not modify the smooth muscle tone of the isolated guinea pig oviduct in the concentration range from 10(-7)M to 3 X 10(-4)M. The contractile response of the oviductal smooth muscle to adrenaline after bilateral ovariectomy was inhibited by estrogen treatment, while relaxation was inhibited by progesterone treatment.

[Continuous subcutaneous infusion of GnRH agonist: effective dosage in the treatment of endometriosis and its influence on the ovarian response to human menopausal gonadotropin]

This study was designed to compare the clinical and hormonal efficacy of the treatment for endometriosis using continuous infusion of three different doses of GnRH agonist (A). In addition, we examined the ovarian responsiveness to human menopausal gonadotropin (hMG) administration during GnRH-A treatment. Thirteen endometriosis patients were divided into 3 groups and given different doses. GnRH-A (Buserelin) was infused continuously through the subcutaneous route at rates of 200 micrograms (Group I; n = 5), 100 micrograms (Group II, n = 4) and 10 micrograms (Group III; n = 4) per day for 24 weeks. After the start of treatment, serum estradiol (E2) was suppressed to the menopausal range within 2 weeks and thereafter maintained this range until 24 weeks in each group. The LH and FSH response to a GnRH Challenge test was completely abolished within 2 weeks in 3 groups. Although serum FSH decreased to below the pretreatment value within a week, the FSH level was significantly lower in groups I and II than in group III until 8 weeks. No difference in the LH level during the treatment was seen among the 3 groups. After completion of the 24 weeks' treatment, FSH increased rapidly, and ovulation returned within 4 to 6 weeks in each group. Pregnancy was achieved in two patients in group I, one patient in group II and one patient in group III during cycles 2 and 5. Serum E2 increased to 200-300 pg/ml in 3 out of 7 patients treated with hMG during GnRH-A infusion, whereas no increase in E2 was seen in the remaining 4 patients.(ABSTRACT TRUNCATED AT 250 WORDS)

[Successful treatment of endometriosis in women with continuous subcutaneous infusion of gonadotropin-releasing hormone agonist (GnRH-A)]

The clinical and hormonal effectiveness of continuous infusion of GnRH-agonist (A) for the treatment of endometriosis was investigated. Five women with endometriosis (stage II-IV) were treated with continuous subcutaneous infusion of 200 micrograms of GnRH-A (Buserelin) per day for 24 weeks. Serum LH and FSH levels increased initially and then FSH levels declined markedly below pretreatment values within a week, followed by a gradual decrease to the normal range of LH levels within 4 weeks. Serum estradiol decreased below early follicular phase levels within 1 to 3 weeks and thereafter continued to decrease to near castrate levels. The LH and FSH responses to 100 micrograms GnRH challenge test were almost completely abolished within 2 weeks. The pulsatile secretion of LH and FSH were also abolished, when assessed at 16 weeks. The tendency toward the slight but significant elevation in FSH levels without an increase in estradiol was noted from about 12 weeks. No vaginal bleeding or spotting was observed in four of the five patients during the course of the treatment. After completion of the 24 weeks of treatment, FSH increased rapidly to the early follicular phase range, and ovulation returned within 4 weeks. Two of the five patients became pregnant during cycles 2 and 5. From these results, we conclude that continuous sc infusion of GnRH-A is highly effective for complete suppression of the pituitary-ovarian function in patients with endometriosis. Further, this treatment appears to be safe and acceptable, because of its rapid reversibility and its lack of side effects.