Association between low MCV in early pregnancy and perinatal mental health in the Japan Environment and Children's Study and the possible effect of iron deficiency.

BACKGROUND: Postpartum anemia and iron deficiency are associated with postpartum depression. This study investigated the association between a low mean corpuscular volume (MCV) without anemia (which implies early-stage iron deficiency) in early pregnancy and perinatal mental health outcomes. METHODS: The fixed data from the Japan Environment and Children's Study (JECS), a Japanese nationwide birth cohort, were used. Perinatal mental health was assessed using the Kessler 6-item psychological distress scale (K6) in mid-pregnancy and the Edinburgh Postnatal Depression Scale (EPDS) at 1- and 6-months postpartum. RESULTS: Among the 3635 women with MCVs <85 fL in early pregnancy, the proportions of women with K6 scores ≥13 in mid-pregnancy and EPDS scores ≥9 at 1- and 6-months postpartum were 2.7 %, 12.8 %, and 9.9 %, respectively, compared with the 33,242 women with MCVs ≥85 fL at 1.9 %, 11.9 %, and 9.0 %, respectively. Multivariate logistic regression models showed that an MCV <85 in early pregnancy was associated with a K6 score ≥ 13 in mid-pregnancy and an EPDS score ≥ 9 at 1- and 6-months postpartum (adjusted odds ratio (95 % confidence interval): 1.48 (1.16-1.87), 1.14 (1.01-1.28), and 1.09 (0.95-1.24), respectively). LIMITATIONS: Low MCV values do not necessarily represent iron deficiency. Ferritin, currently the best indicator of iron deficiency, was not measured in the JECS. CONCLUSIONS: This study results suggest that a low MCV without anemia in early pregnancy is associated with a slightly increased risk of perinatal mental health deterioration.

Investigation of clinical utility of contrast-enhanced MRI in the diagnosis of ectopic pregnancy.

AIM: To investigate whether contrast-enhanced (CE)-magnetic resonance imaging (MRI) improves identification of implantation site of ectopic pregnancy. MATERIALS AND METHODS: This retrospective study enrolled 63 patients in whom implantation sites had been confirmed at histopathology. Two expert radiologists for gynaecological imaging and two inexpert radiologists independently reviewed non-CE MRI and a combination of non-CE and CE-MRI (non-CE+CE-MRI), then determined implantation site with a confidence level. The following MRI features were also evaluated: extrauterine gestational sac (GS)-like structure (shape, signal intensities at T1-weighted imaging [WI], T2WI, and diffusion-weighted imaging [DWI], presence of the three rings appearance, and distinct low intensity areas at T2WI, presence of tree or dot-like components, degree of contrast enhancement), fallopian tube (dilatation, dilatation with haematoma, degree of contrast enhancement, enhanced components within the tube), and ascites. These findings were compared for non-CE and non-CE+CE-MRI data, and for expert and inexpert groups. RESULTS: The expert group identified implantation sites correctly in 58/63 (92%) cases for non-CE and non-CE+CE-MRI. In the inexpert group, the correct identification was improved from 54/63 (86%) using non-CE MRI to 58/63 (92%) using non-CE+CE-MRI, but was not significant (p=0.29). In comparison between non-CE and non-CE+CE-MRI, dilation of the fallopian tubes was observed more frequently (p=0.004) and the confidence level was elevated significantly in the non-CE+CE-MRI (p<0.0001) in the inexpert group. Intergroup comparison revealed that confidence level was significantly higher in the expert group than in the inexpert group using non-CE MRI (p<0.0001), although the difference was not significant at non-CE+CE MRI (p=0.49). CONCLUSION: CE-MRI did not significantly improve correct identification of ectopic pregnancy implantation sites, although the addition of contrast enhancement did enable inexpert radiologists to diagnose confidently.

Frequency and risk factors of thoracic metastases and optimisation of the use of cross-sectional chest imaging in follow-up patients with cervical cancer.

AIM: To optimise cross-sectional chest imaging usage by identifying frequency and risk factors associated with thoracic metastases in cervical cancer patients after initial definitive treatment. MATERIALS AND METHODS: This study, conducted during 2004-2015, examined 361 consecutive patients with histopathologically proven cervical carcinoma with at least 1 year of follow-up. Electronic medical records and all available imaging modes were used to record and assess patient and tumour characteristics and timing of thoracic metastases. Associations with these characteristics and thoracic metastases were assessed using univariate and multivariable Cox proportional hazards modelling. RESULTS: Of the 361 patients, 31 developed thoracic metastases. Multivariate regression results showed that adeno/adenosquamous carcinomas (hazard ratio [HR], 2.46; 95% confidence interval [CI], 1.06 to 5.72), other histology (HR, 5.61; 95% CI, 1.81 to 17.42), high International Federation of Gynaecology and Obstetrics (FIGO) stage (HR, 2.84; 95% CI, 1.09 to 7.37), and presence of initial intra-abdominal lymph node metastases (HR, 2.46; 95% CI, 1.02 to 5.90) were associated significantly and independently with thoracic metastases. The second analysis among the subgroup of surgical treatment identified intermediate-high risk classification of recurrence (HR, 5.12; 95% CI, 1.14 to 22.94), high FIGO stage (HR, 2.73; 95% CI, 1.05 to 7.13), and other histology (HR, 11.51; 95% CI, 3.66 to 36.19) as independent predictors of thoracic metastases. Two of the 361 and 2/313 patients with thoracic metastases who did not correspond to the conditions above were in the respective evaluation groups. CONCLUSION: Assessment of negative prognostic factors for thoracic metastases might contribute to reduced need for chest cross-sectional chest computed tomography examinations.

Determinant factors of postoperative recurrence of endometriosis: difference between endometrioma and pain.

OBJECTIVE: Although the postoperative use of hormonal treatment for endometriosis is recommended in the European Society of Human Reproduction and Embryology guidelines to prevent the recurrence of endometriosis-associated dysmenorrhoea, hormonal treatment may not be necessary for all patients who undergo surgical treatment for endometriosis. The aim of this study was to clarify the determinant factors that predict the recurrence of endometriosis after surgery in order to develop personalized hormonal treatment recommendations. Factors associated with the recurrence of endometrioma and pain were investigated independently to identify the likelihood of recurrence in each individual patient. STUDY DESIGN: Between 2008 and 2013, 352 patients underwent surgery and were diagnosed with endometriosis based on pathological findings at the study hospital. Among these patients, 191 experienced a recurrence of endometrioma in the absence of pre- or postoperative hormonal treatment. Various clinical factors such as pre-operative pain, intra-operative findings and postoperative improvement of pain were compared between patients who experienced recurrence after surgery and those who did not. RESULTS: The cumulative 5-year recurrence rate of endometrioma was 28.7% among the 191 patients who did not undergo pre- or postoperative hormonal treatment. Significant differences were detected in maximum tumour diameter, revised American Society for Reproductive Medicine score (r-ASRM score), operative time and operative blood loss between patients in the recurrent endometrioma group and the non-recurrent endometrioma group; only the r-ASRM score was significantly correlated with recurrence of endometrioma in the multivariate analysis. The cumulative 5-year rate of persistent/recurrent pain was 33.4%. There were significant differences in the postoperative improvement of pain between the persistent/recurrent pain group and the non-recurrent pain group according to the univariate and multivariate analyses. CONCLUSION: This study suggests that the risk factors for recurrence of endometrioma differ from the risk factors for recurrence of pain. The use of postoperative hormonal treatment should be considered based on the dominant risk factors and needs of each patient.

IFN-γ from lymphocytes induces PD-L1 expression and promotes progression of ovarian cancer.

BACKGROUND: PD-L1 (programmed cell death 1 ligand 1) on tumour cells suppresses host immunity through binding to its receptor PD-1 on lymphocytes, and promotes peritoneal dissemination in mouse models of ovarian cancer. However, how PD-L1 expression is regulated in ovarian cancer microenvironment remains unclear. METHODS: The number of CD8-positive lymphocytes and PD-L1 expression in tumour cells was assessed in ovarian cancer clinical samples. PD-L1 expression and tumour progression in mouse models under conditions of altering IFN-γ signals was assessed. RESULTS: The number of CD8-positive cells in cancer stroma was very high in peritoneally disseminated tumours, and was strongly correlated to PD-L1 expression on the tumour cells (P<0.001). In mouse models, depleting IFNGR1 (interferon-γ receptor 1) resulted in lower level of PD-L1 expression in tumour cells, increased the number of tumour-infiltrating CD8-positive lymphocytes, inhibition of peritoneal disseminated tumour growth and longer survival (P=0.02). The injection of IFN-γ into subcutaneous tumours induced PD-L1 expression and promoted tumour growth, and PD-L1 depletion completely abrogated tumour growth caused by IFN-γ injection (P=0.01). CONCLUSIONS: Interferon-γ secreted by CD8-positive lymphocytes upregulates PD-L1 on ovarian cancer cells and promotes tumour growth. The lymphocyte infiltration and the IFN-γ status may be the key to effective anti-PD-1 or anti-PD-L1 therapy in ovarian cancer.

Characteristics of fine vascular network pattern associated with recurrence of polypoidal choroidal vasculopathy.

OBJECTIVE: To characterize an irregular capillary-like structure in the vascular network of eyes with polypoidal choroidal vasculopathy (PCV), and to determine whether its presence after photodynamic therapy (PDT) can be used to predict the clinical course of PCV. METHODS: We reviewed the clinical records of 29 eyes of 29 patients with PCV, who underwent PDT and confocal retinal angiographic examinations every 3 months. The images obtained before the PDT were compared with those after the PDT. The correlations between angiography findings and recurrences were evaluated. RESULTS: An area of fine, densely packed capillary-like vessels, named the fine vascular network, was identified within the polypoidal vascular network in 25 of 29 cases at the initial examination. The fine vascular network regressed in 23 cases (92%) after the first PDT. Thereafter, the fine vascular network remained or enlarged in 19 eyes, and 17 (84.5%) of these eyes had a recurrence of the polypoidal lesions or had exudative changes. In contrast, recurrences were found in only 2 of 10 (20%) eyes, whose fine network had regressed without a subsequent enlargement (P<0.001 compared with the former group). CONCLUSIONS: A fine irregular vascular network is present in the majority of eyes with PCV before PDT. Its presence or expansion after PDT was significantly associated with a recurrence of PCV. Thus, we recommend that this network be monitored after treatment to determine whether a polypoidal vascular network will recur.

Assessment of hepatocellular carcinoma by contrast-enhanced ultrasound with perfluorobutane microbubbles: comparison with dynamic CT.

OBJECTIVE: The aim of this study was to evaluate tumour vascularity and Kupffer cell imaging in hepatocellular carcinoma (HCC) using contrast-enhanced ultrasonography (CEUS) with Sonazoid (perfluorobutane) and to compare performance with dynamic CT. METHODS: We studied 118 nodules in 88 patients with HCC. HCC was diagnosed as a hyperenhancement lesion in the arterial phase with washout in the portal phase on dynamic CT or by percutaneous biopsy. We observed tumour vascularity at the early vascular phase (10-30 s after contrast injection) and Kupffer imaging at the post-vascular phase (after 10 min). RESULTS: Detection of vascularity at the early vascular phase was 88% in nodules that were found to be hypervascular on dynamic CT and 28% in hypo-/isovascular nodules; the detection of local recurrence nodules was 92%. The detection of vascularity was significantly lower in nodules >9 cm deep than in those ≤9 cm deep, but was not affected by tumour size. The detection of tumours at the post-vascular phase on CEUS was 83% in nodules with low density in the portal phase on dynamic CT and 82% in nodules with isodensity. The rate did not depend on the severity of underlying liver disease; rates decreased in nodules deeper than 9 cm, those smaller than 2 cm in diameter and in iso-enhancing nodules at the early vascular phase of CEUS. CONCLUSION: CEUS with Sonazoid is a useful tool for assessing the vascularity of HCC and is equal to that of dynamic CT; however, the detectability of HCC vascularity is affected by location.

Identification of an ovarian clear cell carcinoma gene signature that reflects inherent disease biology and the carcinogenic processes.

Ovarian clear cell carcinoma (OCCC) shows unique clinical features including an association with endometriosis and poor prognosis. We previously reported that the contents of endometriotic cysts, especially high concentrations of free iron, are a possible cause of OCCC carcinogenesis through iron-induced persistent oxidative stress. In this study, we conducted gene expression microarray analysis using 38 ovarian cancer cell lines and identified genes commonly expressed in both OCCC cell lines and clinical samples, which comprise an OCCC gene signature. The OCCC signature reproducibly predicts OCCC specimens in other microarray data sets, suggesting that this gene profile reflects the inherent biological characteristics of OCCC. The OCCC signature contains known markers of OCCC, such as hepatocyte nuclear factor-1beta (HNF-1beta) and versican (VCAN), and other genes that reflect oxidative stress. Expression of OCCC signature genes was induced by treatment of immortalized ovarian surface epithelial cells with the contents of endometriotic cysts, indicating that the OCCC signature is largely dependent on the tumor microenvironment. Induction of OCCC signature genes is at least in part epigenetically regulated, as we found hypomethylation of HNF-1beta and VCAN in OCCC cell lines. This genome-wide study indicates that the tumor microenvironment induces specific gene expression profiles that contribute to the development of distinct cancer subtypes.

Identifying pathogenic genetic background of simplex or multiplex retinitis pigmentosa patients: a large scale mutation screening study.

BACKGROUND AND PURPOSE: More than half of the retinitis pigmentosa (RP) cases are genetically simplex or multiplex. To date, 37 causative genes of RP have been identified; however, the elucidation of gene defects in simplex or multiplex RP patients/families remains problematic. The aim of our study was to identify the genetic causes of RP in patients with unknown or non-Mendelian inheritance. METHODS AND RESULTS: Since 2003, 52 simplex RP patients, 151 patients from 141 multiplex RP families, and six sporadic patients with retinal degeneration were studied. A total of 108 exons of 30 RP-causing genes that harboured the reported mutations were screened by an efficient denaturing high performance liquid chromatography (dHPLC) based assay. Aberrant fragments were subsequently analysed by automatic sequencing. Twenty-six mutations, including two frameshift mutations, one single amino acid deletion, and 23 missense mutations, were identified in 28 probands (14.07%). Eighteen mutations have not been reported to date. Three pairs of combined mutations in different genes were identified in two sporadic cases and one multiplex family, indicating the possibility of novel digenic patterns. Of the 23 missense mutations, 21 were predicted as deleterious mutations by computational methods using PolyPhen, SIFT, PANTHER, and PMut programs. CONCLUSION: We elucidated the mutation spectrum in Japanese RP patients and demonstrated the validity of the mutation detection system using dHPLC sequencing for genetic diagnosis in RP patients independent of familial incidence, which may provide a model strategy for identifying genetic causes in other diseases linked to a wide range of genes.

Increased cyclooxygenase-2 expression is correlated with suppressed antitumor immunity in cervical adenocarcinomas.

Cyclooxygenase-2 (COX-2) inhibition suppressed the growth of various tumors. The augmentation of antitumor immunity by increasing cytotoxic lymphocytes may be an important mechanism for COX-2 inhibition. Among cervical cancers, adenocarcinomas present more aggressive behavior and overexpressed COX-2. The expression of COX-2 and the CD8+ lymphocyte infiltrations were evaluated in this study by immunohistochemistry. We studied COX-2 expression and CD8+ lymphocyte infiltration in 55 women with cervical adenocarcinomas. COX-2 expression and tumor stromal CD8+ lymphocytes were evaluated by semiquantified methods. Tumor intraepithelial lymphocytes were counted under microscopic field of x200. Correlations between these data and other clinicopathologic features were investigated. Thirty-seven out of 55 (67.3%) cervical adenocarcinomas significantly expressed COX-2. Patients who died within 5 years showed higher percentage of COX-2 expression than survivors (100% vs 58.1%, P < 0.05). Victims also showed lesser intraepithelial CD8+ lymphocyte counts than survived patients (3.4 vs 26.4, P < 0.05). COX-2 expression and tumor intraepithelial lymphocyte count were reversely correlated with each other (correlation index: -0.38, P < 0.01). Up-regulated COX-2 expression and lesser tumor intraepithelial CD8+ lymphocyte count are poor prognostic indicators for cervical adenocarcinoma patients. COX-2 may play an important role in the suppression of host antitumor immunity in cervical adenocarcinomas.

C-erbB-2 or mutant Ha-ras induced malignant transformation of immortalized human ovarian surface epithelial cells in vitro.

Ovarian cancer is believed to develop from the ovarian surface epithelium through the accumulation of aberrations of oncogenes and/or tumor suppressor genes. However, it is unclear how the gene abnormalities are involved in ovarian carcinogenesis. To elucidate the process, we transfected genes reported to show their abnormalities in human ovarian cancers into human ovarian surface epithelial cells. Immortalization of the cells was achieved by the transfection of SV40 large T antigen (LT) and human telomerase reverse transcriptase (hTERT); however, the resultant cells showed no tumorigenesis. Additional transfection of either c-erbB-2 or mutant Ha-ras into the immortalized cells showed the anchorage-independent growth and tumorigenesis in mice with the incidence of 50% and 40%, respectively. Histologically, all the tumours were undifferentiated. In association with the tumorigenesis, the cells expressing c-erbB-2 or mutant Ha-ras demonstrated increased vascular endothelial growth factor secretion under hypoxia and enhanced resistance to apoptosis compared with the immortalized cells. Collectively, the introduction of either c-erbB-2 or mutant Ha-ras in the cells, which were efficiently immortalized by the transfection of LT and hTERT, showed tumorigenicity, suggesting that c-erbB-2 or mutant Ha-ras genes might be involved in ovarian carcinogenesis.

Krukenberg tumor from an occult appendiceal adenocarcinoid: a case report and review of the literature.

Appendiceal neoplasms with ovarian metastasis are rare. A 35-year-old woman with a left ovarian tumor underwent left salpingo-oophorectomy, partial resection of the right ovary, and a total hysterectomy. Pathological diagnosis of both ovaries was typical, Krukenberg tumor with signet-ring cells, and the second laparotomy revealed an occult appendiceal tumor to be the primary lesion. The appendix showed no evidence of malignant change of the mucosa, but the tumor cells were observed infiltrating from the basiglandular region into the underlying stroma, associated with mucocele. Although, argentaffin and argyrophil staining were negative, a few tumor cells showed immunohistochemical positivity for Chromogranin A. Accordingly, the tumor was diagnosed as adenocarcinoid rather than adenocarcinoma of the appendix. A review of the literature showed less than 40 cases of metastatic ovarian tumor from appendiceal primary, one-third of which were occult and could be detected at the second laparotomy. Cisplatin-based chemotherapy may have partial effect in the treatment of patient with adenocarcinoid tumor.

Clinical value of positron emission tomography with FDG for recurrent ovarian cancer.

OBJECTIVE: Recurrence is often a major problem for patients who have undergone surgery for ovarian cancer. This prospective study was undertaken to evaluate the clinical contribution of positron emission tomography (PET) using (18)F-fluorodeoxyglucose (FDG) for recurrent ovarian cancer. SUBJECTS AND METHODS: Twenty-four women who had undergone surgery or chemoradiotherapy for histopathologically proven ovarian cancer were enrolled in this study. Ovarian cancer was thought to have recurred in 12 of these women because of evidence on conventional imaging modalities or tumor marker measurements (group A). Clinical findings for the remaining 12 women showed them to be disease-free (group B). PET findings for the women were compared with the final diagnoses obtained by histopathology or by clinical follow-up. The clinical contribution of PET was assessed by evaluating whether PET yielded information complementing the findings of conventional modalities and by examining its impact on treatment. RESULTS: PET gave valuable information for seven of 12 patients in group A in addition to the information obtained from findings on conventional imaging, and treatment was affected in five patients. On the other hand, in group B, additional information was obtained in only three of 12 patients, and treatment of only one patient was affected. Overall sensitivity, specificity, and accuracy of conventional imaging modalities were 72.7%, 75.0%, and 73.3%, respectively, and these rates improved to 92.3%, 100.0%, and 94.4%, respectively, by considering both conventional imaging modalities and PET findings. CONCLUSION: Our preliminary data suggest that whole-body PET with FDG can be a complementary modality for following up patients who have had ovarian cancer, especially patients believed to be at risk for recurrence.

Combination effect of adenovirus-mediated pro-apoptotic bax gene transfer with cisplatin or paclitaxel treatment in ovarian cancer cell lines.

To develop a novel therapeutic strategy for ovarian cancer, we constructed a recombinant adenovirus which highly expresses pro-apoptotic Bax protein and examined its therapeutic effect on a series of ovarian cancer cell lines: A2780, A2780/cDDP, OVCAR-3 and SK-OV-3. A recombinant adenovirus carrying the Bax-alpha gene (AxCALNKYbax) induced high expression of the Bax-alpha protein in all the cell lines. The cytotoxic effect of Bax was observed in three ovarian cancer cell lines: the per cent reduction in the number of cells was 40.0% for cisplatin-sensitive A2780, 50.0% for cisplatin-resistant A2780/cDDP, and 64.8% for marginally cisplatin-resistant OVCAR-3. In contrast, it was only 12.3% for cisplatin-resistant SK-OV-3. Cisplatin-resistant A2780/cDDP had a p53 mutation and exhibited attenuated Bax induction after cisplatin treatment, which may explain why supplementation of Bax was effective in this chemoresistant ovarian cancer. Combination with cisplatin or paclitaxel enhanced the cytotoxic effect of Bax induction in all but one cell line including cisplatin-resistant A2780/cDDP. It appears that adenovirus-mediated Bax induction, with or without combination with conventional chemotherapy, useful strategy for the treatment of ovarian cancer.

Human ovarian surface epithelial (OSE) cells express LH/hCG receptors, and hCG inhibits apoptosis of OSE cells via up-regulation of insulin-like growth factor-1.

Gonadotropins including luteinizing hormone (LH) or human chorionic gonadotropin (hCG) have been implicated as playing an important role in the development of epithelial ovarian carcinomas, most of which are believed to originate from the ovarian surface epithelium (OSE). To address this issue, we examined the expression of LH/hCG receptors and the influence of hCG on cell proliferation and on the apoptosis of cultured human OSE cells. RT-PCR and binding assay revealed that OSE cells express the LH/hCG receptor mRNA and have specific binding activity for hCG. Treatment with hCG stimulated the proliferation of OSE cells in a dose-dependent manner. In addition, hCG treatment inhibited the apoptosis of OSE cells induced by serum deprivation. Among the apoptosis-related genes, hCG treatment did not change the mRNA levels of bcl-2, bax and IGF-1 receptor but significantly increased that of IGF-1. Treatment with IGF-1 alone also suppressed the apoptosis of OSE cells, and treatment by hCG along with neutralization antibody against IGF-1 receptor reversed the anti-apoptotic effect of hCG. Accordingly, LH/hCG signaling followed by up-regulation of IGF-1 is involved in the inhibition of apoptosis of OSE cells, the possible histogenetic origin of epithelial ovarian carcinomas.

Long-term outcome after radiation therapy for subfoveal choroidal neovascularization associated with age-related macular degeneration.

PURPOSE: The purpose of this study was to investigate the long-term effect of low-dose radiation therapy on subfoveal choroidal neovascularization associated with age-related macular degeneration. METHODS: The clinical course and visual outcome were compared retrospectively among two treated groups and a control group; 15 patients (15 eyes) received 10 Gy, another 15 patients (15 eyes) received 20 Gy. The control group consisted of 15 patients (15 eyes) without treatment. All patients were followed up for at least 18 months, and most were followed up for 3 years. The macula was irradiated with either 10 Gy in 5 fractions or with 20 Gy in 10 fractions after computed tomography (CT) simulation enabled real-time treatment planning from multiple CT slices. RESULTS: During the 3 years of follow-up, the lesions became better in 5 eyes, unchanged in 1, and worse in 9 with 10 Gy radiation; better in 7 eyes, unchanged in 1, and worse in 7 eyes with 20 Gy; and better in 1 eye and worse in 14 with no treatment. The difference between the groups treated with radiation and the control was statistically significant (P <.05). Visual acuity was also significantly better in the group receiving 20 Gy than in the control group up to 2 years after radiation (P <.01). CONCLUSION: Radiation may extend the period of good visual function substantially by reducing subfoveal choroidal neovascularization activity.

Prostaglandin E (EP) receptor subtypes and sleep: promotion by EP4 and inhibition by EP1/EP2.

Prostaglandin (PG) E2 reportedly augmented wakefulness when continuously infused into the third ventricle of the rat brain, whereas it promoted sleep when continuously infused into the subarachnoid space of the ventral surface zone of the rostral basal forebrain, which was designated previously as a PGD2-sensitive sleep-promoting zone (PGD2-SZ). In the present study, we investigated the effects of PGE (EP)-receptor agonists on sleep-wakefulness activities by infusing agonists into the third ventricle or into the subarachnoid space of the PGD2-SZ. Our results indicated that the waking effect is mediated by EP1 and EP2 receptors situating around the third ventricle, whereas the sleep-promoting effect is brought about mainly through activation of EP4 receptors located at or near the subarachnoid space of the PGD2-SZ.

Administration of 17beta-estradiol attenuates retinal ischemia-reperfusion injury in rats.

PURPOSE: Accumulating evidence has suggested that 17beta-estradiol exerts protective effects against ischemic damage in various organs. In addition, leukocytes that accumulate in postischemic tissues are thought to play a central role in ischemia-reperfusion injury. This study was designed to evaluate quantitatively the inhibitory effects of 17beta-estradiol on leukocyte accumulation during ischemia-reperfusion injury and on subsequent retinal damage after transient retinal ischemia. METHODS: Transient (60 minutes) retinal ischemia was induced in male rats by temporary ligation of the optic nerve. Thirty minutes before induction of ischemia, 17beta-estradiol (0.1 mg/kg) was administered intraperitoneally. At 6, 12, 24, and 48 hours after reperfusion, leukocyte accumulation in the retina was evaluated in vivo by means of acridine orange digital fluorography. Histologic and electroretinographic (ERG) studies were carried out to evaluate retinal damage. RESULTS: Treatment with 17beta-estradiol significantly inhibited postischemic leukocyte accumulation; the maximum number of accumulating leukocytes was reduced by 35.7% at 24 hours after reperfusion (P = 0.01). Histologic examination showed that administration of 17beta-estradiol significantly reduced retinal damage, which was most obvious in the inner retina, 168 hours after reperfusion (P = 0.0001). ERG studies at 12 and 168 hours after reperfusion showed that recovery of the b-wave amplitude was significantly improved with treatment of 17beta-estradiol (P = 0.023). CONCLUSIONS: The present study demonstrated the inhibitory effects of 17beta-estradiol on leukocyte accumulation and subsequent tissue injury during retinal ischemia-reperfusion injury.

Nitric oxide as a second messenger in phagocytosis by cultured retinal pigment epithelial cells.

PURPOSE: To investigate a possible role of the nitric oxide (NO)-cGMP signal transduction system in phagocytosis of rod outer segments (ROS) by cultured retinal pigment epithelial (RPE) cells. METHODS: Primary cultures of RPE cells from 10-day-old Brown Norway rats were used to study the phagocytosis of ROS by these cells. Phagocytosis of ROS was evaluated with or without an inhibitor of nitric oxide synthase (NOS), N(G)-nitro-L-arginine (L-NNA), and the reverse effects of L-NNA by L-arginine and 8-bromo-cGMP on phagocytosis were also studied. NO-associated cGMP production by RPE cells was monitored during phagocytosis using L-NNA. NOS activity was assayed in RPE cells and ROS to locate the source of NO. RESULTS: Phagocytosis of ROS was inhibited by L-NNA but not by D-NNA. L-NNA inhibited the ingestion in a dose-dependent manner, but not the binding of ROS. The inhibition was reversed by L-arginine and also by an NO donor, SIN-1. RPE cells challenged with ROS showed increased cGMP activity, which was significantly reduced by L-NNA and again restored by an overdose of L-arginine. NOS activity was found in RPE cells but not in ROS. CONCLUSIONS: Our data show that cGMP plays a role in the ingestion phase of ROS phagocytosis by RPE cells via a cGMP second-messenger system.