Endothelin synthesis and receptors in human endometrium throughout the normal menstrual cycle

This study was undertaken to investigate the presence of messengerRNA (mRNA) for prepro-endothelin-I (ET-1) and the known receptorsubtypes (ETA and ETB) in human endometrium at different stagesof the menstrual cycle obtained at hysterectomy. Northern blotanalysis revealed expression of ET-1 mRNA in human endometriumduring the normal menstrual cycle. The concentration of ET-1mRNA in endometrial tissue was greater during the menstrualand proliferative phases than during the ovulatory and secretoryphases. Immunoreactive ET-1 was secreted into the medium ofisolated endometrial stromal cells. Oestradiol and progesteronesignificantly attenuated ET-1 release in endometrial stromalcells cultured for 6 days. ETA and ETB mRNA were also presentin endometrial tissue of the normal cycle. The concentrationof ETA receptor mRNA was greater in the proliferative phasethan in the secretory phase, whereas expression of ETB mRNAincreased in menstrual phase. ET-1 significantly increased extracellularaccumulation of cyclic AMP (cAMP), intracellular generationof inositol phosphates and significantly enhanced DNA synthesisin cultured endometrial stromal cells from the proliferativephase. Our results showed that human endometrial cells synthesizedand released ET-1, and contained ETA and ETB receptors whichwere functionally coupled to phosphoinositide breakdown andto adenylate cyclase with the increase of cAMP by ET-1 stimulation.Our findings suggest that ET-1 may have a potential autocrineand/or paracrine function in human endometrial stromal cells.     

Hyperbaric exposure with high oxygen concentration enhances oxidative capacity of neuromuscular units

The effects of hyperbaric exposure with high oxygen concentration on spinal motoneurons and the skeletal muscle fibers that they innervate were investigated. Five-week-old male rats were exposed to a hyperbaric (1.25 atmospheric pressure) environment with a high oxygen concentration (35.0%) for 6h daily. The number, cell body size, and oxidative enzyme activity of motoneurons innervating the soleus and plantaris muscles were examined after 8 weeks of hyperbaric exposure. In addition, the fiber type distribution, cell size, and oxidative enzyme activity of the slow soleus and fast plantaris muscles were examined. The oxidative enzyme activity of alpha motoneurons innervating the soleus and plantaris muscles increased after hyperbaric exposure, irrespective of their cell body sizes. The percentage of high-oxidative fibers in the soleus and plantaris muscles increased after hyperbaric exposure. The oxidative enzyme activity of all types of fibers in the soleus and plantaris muscles increased after hyperbaric exposure. It is concluded that hyperbaric exposure with high oxygen concentration enhances the oxidative capacity of neuromuscular units.     

Retrospective study on amplification of N-myc and c-myc genes in pediatric solid tumors and its association with prognosis and tumor differentiation

DNA was extracted from formalin-fixed and paraffin-embedded tissues of 85 patients with pediatric malignant solid tumors which had been resected at surgery or obtained at autopsy during a 24-year period. The tumors examined included 25 rhabdomyosarcomas, 12 Wilms' tumors, 10 hepatoblastomas and 37 neuroblastoma group tumors. Neuroblastoma group tumors were subclassified into 25 neuroblastomas and 12 ganglioneuroblastomas among which 6 composite ganglioneuroblastomas were included. Sample blocks were selected from both tumors and normal tissues in the majority of cases. We were able to reliably detect N- and c-myc gene amplification in tumor DNA by dot blot-hybridization. The N-myc gene showed approximately from 3- to 500-fold amplification in 19 of 33 cases of stage IV neuroblastoma group tumor. All of these 33 patients had been intensively treated with chemotherapy and/or radiotherapy. The c-myc was amplified 8-fold in 1 case of rhabdomyosarcoma, but neither N-myc nor c-myc was amplified in any cases of Wilms' tumor or hepatoblastoma. We retrospectively examined the association among N-myc gene amplification, prognosis, and histologic subtype in 33 patients with stage IV neuroblastoma group tumors. The survival of the patients with N-myc gene amplification was shorter than that of the patients without amplification of N-myc (p less than 0.05). There was no significant difference in prognosis between the 2 histologic subtypes; neuroblastoma and ganglioneuroblastoma, and the cases of tumors with amplified N-myc showed shorter survivals for each subtype (p less than 0.05). In every case of neuroblastoma group tumor, the copy number of the N-myc gene was the same among primary site and multiple metastatic tumors, even when the lesions showed differences in histologic subtype like neuroblastoma and ganglioneuroblastoma.     

Attenuation of retinal photooxidative damage in thioredoxin transgenic mice

Thioredoxin (TRX) is an endogenous redox (reduction/oxidation) regulator that has cytoprotective effects against various types of oxidative stresses. Exposure to excessive levels of white light induces retinal photoreceptor damage. To test the cytoprotective effect of overexpressed TRX against retinal photooxidative damage, both TRX transgenic (trx-tg) mice and C57BL/6 (wild type) mice were exposed to intense white fluorescent light. The amounts of oxidized and tyrosine-phosphorylated proteins decreased in the neural retinas of the trx-tg mice compared to the wild type mice after light exposure. The electroretinographic amplitudes were higher and the formation of oxidized DNA was lower in trx-tg mice compared to wild type mice after light exposure. These results suggest that overexpression of TRX suppresses retinal photooxidative damage. TRX intensification may be a useful therapeutic strategy to prevent retinal photic injury.     

Effects of running exercise during recovery from hindlimb unloading on soleus muscle fibers and their spinal motoneurons in rats

The effects of hindlimb unloading and recovery with or without running exercise on morphological and metabolic properties of soleus muscle fibers and their spinal motoneurons in rats were investigated. Ten-week-old rats were hindlimb suspended for 2 weeks and thereafter were rehabilitated with or without voluntary running exercise for 2 weeks. A decreased percentage of type I fibers and atrophy of all types of fibers were observed after hindlimb unloading. In addition, decreased oxidative enzyme activity of all types of fibers was observed after hindlimb unloading. In contrast, an improvement in the decreased percentage of type I fibers, decreased fiber cross-sectional area, and decreased fiber oxidative enzyme activity was observed after recovery with running exercise, but not without running exercise. There were no changes in the number, cell body size, or oxidative enzyme activity of motoneurons innervating the soleus muscle after hindlimb unloading or recovery with or without running exercise. These results indicate that running exercise is beneficial for the recovery of the decreased percentage of type I fibers and the atrophy and decreased oxidative enzyme activity of all types of fibers in the soleus muscle induced by hindlimb unloading and that there are no changes in morphological or metabolic properties of spinal motoneurons innervating the soleus muscle following decreased or increased neuromuscular activity.     

Elevated expression of E-cadherin and α-, β-, and γ-catenins in metastatic lesions compared with primary epithelial ovarian carcinomas

E-cadherin and catenins play key roles in cell adhesion and motility. Little is known about the changes in expression of these molecules in the progression of ovarian carcinomas. In the present study, the immunohistochemical expression of E-cadherin and α-, β-, and γ-catenins was examined in 77 cases of ovarian carcinoma. In addition, the expression of these molecules was evaluated in 26 matched pairs of primary and metastatic lesions of advanced ovarian carcinomas. Of the 77 primary lesions, positive staining for E-cadherin and α-, β-, and γ-catenin was observed in 75 (97%), 63 (82%), 71 (92%) and 57 (74%) cases, respectively. Positivity for E-cadherin and α-, β-, and γ-catenin was significantly decreased in stage III and IV tumors compared with stage I and II tumors, suggesting that expression of the cadherin-catenin complex is reduced with the advancing stages of a tumor. Interestingly, expression of E-cadherin and α-, β-, and γ-catenin in the lesions of peritoneal dissemination was significantly increased compared with the primary lesions. These findings suggest that expression of the cadherin-catenin complex changes markedly and that reexpression may occur during the peritoneal dissemination of ovarian carcinoma cells.     

Expression of BRCA1 protein in benign, borderline, and malignant epithelial ovarian neoplasms and its relationship to methylation and allelic loss of the BRCA1 gene

BRCA1 is a putative tumour suppressor gene responsible for a hereditary ovarian cancer syndrome. To clarify the possible involvement of BRCA1 in the development of sporadic ovarian neoplasms, this study analysed the immunohistochemical expression of BRCA1 protein in normal ovarian surface epithelium and 119 epithelial ovarian tumours (19 benign, 24 borderline, and 76 malignant tumours). Loss of heterozygosity (LOH) of BRCA1 was examined using three microsatellite markers to analyse the relationship between BRCA1 expression and alterations of the BRCA1 gene. Methylation of the BRCA1 promoter was also analysed by methylation-specific PCR. In ovarian carcinomas showing heterogeneous expression of BRCA1 protein in the same tumour, LOH and methylation status were analysed using microdissection techniques. Finally, the relationship of BRCA1 expression or its genetic alteration to clinicopathological parameters and patient survival was analysed. Ovarian surface epithelial cells expressed BRCA1 protein. Decreased expression of BRCA1 was found in 16% of benign tumours, 38% of borderline tumours, and 72% of carcinomas. LOH of BRCA1 was demonstrated in no benign tumours, 15% of borderline tumours, and 66% of carcinomas. Methylation of BRCA1 was not detected in benign or borderline tumours, but was present in 31% of carcinomas. Reduced expression of BRCA1 correlated with the presence of gene methylation. The frequency of BRCA1 methylation and LOH was higher in serous carcinomas than in other types. In one of the three serous carcinomas that showed heterogeneous expression of BRCA1, BRCA1-positive borderline-like tumour cells were LOH-positive and methylation-negative, whereas adjacent BRCA1-negative carcinoma cells were LOH-positive and methylation-positive. The prognosis of carcinoma patients did not correlate with BRCA1 expression or genetic status. These findings suggest that reduced expression of BRCA1 protein along with genetic and epigenetic changes of the BRCA1 gene play an important role in the development of sporadic ovarian carcinomas, particularly those of serous histology.     

Expression of CD56 antigen on acute nonlymphocytic leukemia]

CD56 antigen (detected by NKH-1) is distributed on NK cells, monocytes, and ectodermal neural cells. In this study, the blasts of 29.2% of 27 patients with acute nonlymphocytic leukemia (ANLL) expressed CD56 antigen, but not CD16, CD2, or CD3 antigen. Leukemic cells isolated from 3 patients with CD56-positive ANLL did not have NK activity. There were no significant differences between CD56-positive and CD56-negative ANLL in CD13-positive cases, CD33-positive cases, and HLA-DR-positive cases. These results suggest that CD56-positive ANLL could be so-called mixed-lineage leukemia (lymphoid-associated antigen in ANLL).