Effects of oxytocin in postmenopausal rats

Recent studies have revealed that the administration of oxytocin has beneficial effects on the regulation of body weight, food intake, and metabolic functions, especially in obese individuals. Obesity is common in women after the menopause and drives many components of metabolic syndrome. Weight gain in menopausal women has been frequently reported. Although obesity and associated metabolic disorders are frequently observed in peri- and postmenopausal women, there are few medical interventions for these conditions. In this study, we evaluated the effects of chronic oxytocin administration on appetite, body weight, and fat mass in peri- and postmenopausal female rats. Sixteen naturally premenopausal or menopausal rats were intraperitoneally injected with oxytocin (1,000 μg/day) for 12 days. The daily changes in their body weight and food intake were measured at the same time as the oxytocin and vehicle injections. Intraperitoneally administering oxytocin for 12 days significantly reduced food intake, body weight, and visceral adipocyte size. In addition, oxytocin administration caused reductions in serum triglyceride and low-density lipoprotein-cholesterol levels, while it did not disturb hepatic or renal functions or locomotor activity. This is the first study to show the effects of oxytocin on the metabolic and feeding functions of peri- and postmenopausal female rats. Oxytocin might be a useful treatment for metabolic disorders caused by the menopause or aging

コロナ禍における医学教育への取り組み

The COVID-19 pandemic has profoundly changed medical student clinical practice and limited hospital clinical practice. In order to make student training more meaningful, we have introduced medical education using a laparoscopic simulator. We conducted a student questionnaire on the usefulness of this training and evaluated the degree of understanding. For students who were able to practice at the hospital, they practiced using a laparoscopic simulator（Lap Mentor™）. A questionnaire survey was conducted on the presence or absence of interest in surgery. Student understanding of laparoscopic surgery improved 100％. 91％ understood the surgical procedure, 91％ improved technique and 97％ understood pelvic anatomy. In the training at Lap Mentor™, medical students were able to experience surgery while viewing images of the inside of the pelvis, which served as a means to increase their interest in surgery and obstetrics and gynecology

Androgen’s effects in female

The metabolic effects of androgens and their underlying mechanisms in females have been revealed by recent studies. An excess of androgens can have adverse effects on feeding behavior and metabolic functions and induce metabolic disorders / diseases, such as obesity, insulin resistance, and diabetes, in women and experimental animals of reproductive age. Interestingly, these effects of androgens are not observed in ovariectomized animals, indicating that their effects might be dependent on the estrogen milieu. Central and peripheral mechanisms, such as alterations in the activity of hypothalamic factors, reductions in energy expenditure, skeletal muscle insulin resistance, and β-cell dysfunction, might be related to these androgens’ effects

Activin A promotes endometriotic lesions

PURPOSE : This study aimed to investigate the effect of intraperitoneal administration of activin on the occurrence of endometriosis using a mouse model of endometriosis. METHODS : A mouse model of endometriosis was prepared by intraperitoneally administering endometrial tissue and blood collected from donor mice to C57BL/6J 7-8- week-old recipient mice. A total of 400 μg of activin A was intraperitoneally administered to model mice in the activin group for 5 days. Intraperitoneal endometriotic lesions were confirmed macroscopically and IL-6 and TNF-α levels in washed ascites were measured by ELISA. RESULTS : Endometriotic lesions were observed in all mice. In the activin group, the maximum diameter of endometriotic lesions was significantly larger than that in control group (4.7±1.3 vs 2.9±0.9 mm, p<0.01). The total area of the lesion was also significantly higher in the activin group than in the control group (21.1±9.9 vs 8.8±5.4 mm2, p<0.01). Furthermore, IL-6 and TNF-α levels in ascites were significantly higher in the activin group than in the control group (IL-6 : 85.8±15.3 vs 75.1±19.3 pg/ml, p<0.05 ; TNF-α : 629.8±15.4 vs 605.9±11.4 pg/ml, p<0.05). CONCLUSION : Activin promotes occurrence of endometriosis. Inflammatory cytokines are also elevated by activin administration,suggesting that they may contribute to progression of endometriosi

LPS proliferate the endometriosis

Purpose : The aims of this study were to clarify the effects of lipopolysaccharide (LPS) on the early development of endometriosis and on the production of cytokines and chemokines in the murine peritoneal cavity. Methods : Endometriotic lesions were induced in C57BL/6J adult female mice by intraperitoneal injection of endometrial fragments plus blood or endometrial fragments plus blood with LPS. On day 7, endometriotic lesions were assessed by gross and microscopic evaluations. Time-dependent changes in the secretion of TNF-α, IL-6, and CXCL2/MIP-2 in peritoneal lavage fluid after the intraperitoneal injection of LPS (50 µg/body) were measured by their respective enzyme-linked immunosorbent assays. Results : The areas of endometriotic lesions in the LPS group (10.8±8.6 mm2) were significantly larger than those in the control group (3.1±3.7 mm2). The levels of TNF-α and IL-6 peaked within 2 hours and the level of MIP-2 reached a maximum on day 1 after the injection of LPS. Conclusions : LPS promotes development of the early stages of murine endometriotic lesions

A comprehensive functional analysis of tissue specificity of human gene expression

<p>Abstract</p> <p>Background</p> <p>In recent years, the maturation of microarray technology has allowed the genome-wide analysis of gene expression patterns to identify tissue-specific and ubiquitously expressed ('housekeeping') genes. We have performed a functional and topological analysis of housekeeping and tissue-specific networks to identify universally necessary biological processes, and those unique to or characteristic of particular tissues.</p> <p>Results</p> <p>We measured whole genome expression in 31 human tissues, identifying 2374 housekeeping genes expressed in all tissues, and genes uniquely expressed in each tissue. Comprehensive functional analysis showed that the housekeeping set is substantially larger than previously thought, and is enriched with vital processes such as oxidative phosphorylation, ubiquitin-dependent proteolysis, translation and energy metabolism. Network topology of the housekeeping network was characterized by higher connectivity and shorter paths between the proteins than the global network. Ontology enrichment scoring and network topology of tissue-specific genes were consistent with each tissue's function and expression patterns clustered together in accordance with tissue origin. Tissue-specific genes were twice as likely as housekeeping genes to be drug targets, allowing the identification of tissue 'signature networks' that will facilitate the discovery of new therapeutic targets and biomarkers of tissue-targeted diseases.</p> <p>Conclusion</p> <p>A comprehensive functional analysis of housekeeping and tissue-specific genes showed that the biological function of housekeeping and tissue-specific genes was consistent with tissue origin. Network analysis revealed that tissue-specific networks have distinct network properties related to each tissue's function. Tissue 'signature networks' promise to be a rich source of targets and biomarkers for disease treatment and diagnosis.</p

Effect of intraperitoneal docetaxel on ovarian function in mice

Taxanes are important chemotherapeutic agents used to manage breast cancer and gynaecological malignancies. However, ovarian toxicity induced by the taxane docetaxel (DOC) is of great concern. We investigated DOC-induced toxicity in the ovaries of female CD1 strain mice. The mice were divided into control (saline), DOC-5 (5 mg/kg DOC), and DOC-10 (10 mg/kg DOC) groups and administered saline or DOC on the first day of the study and two weeks later. Two weeks after the second dose, the ovaries were removed for analysis after inducing superovulation. Ovary weight, the number of secondary follicles, and the total number of follicles were reduced after DOC administration. Additionally, the expression levels of caspase-3 and the pro-apoptotic protein Bcl-2 interacting mediator of cell death (BIM) increased. Our findings suggest that high-dose DOC induces damage to growing follicles; however, it may not affect primordial follicles.Impact statement What is already known on this subject? Docetaxel (DOC) is one of the most effective chemotherapeutic agents used to manage various cancers. Some in-vitro studies have examined paclitaxel-induced ovarian toxicity; however, limited research on DOC is available. What do the results of this study add? We investigated DOC-induced ovarian toxicity in female CD1 strain mice at 5 mg/kg and 10 mg/kg. We found that DOC reduced ovary weight, the number of secondary follicles, and the total number of follicles, with the higher dose having a higher effect. What are the implications of these findings for clinical practice and/or further research? We believe that our study makes a significant contribution to the knowledge about the effect of DOC on ovarian function

The transcription factor OsNAC4 is a key positive regulator of plant hypersensitive cell death

The hypersensitive response (HR) is a common feature of plant immune responses and a type of programmed cell death. However, little is known about the induction mechanism of HR cell death. We report that overexpression of OsNAC4, which encodes a plant-specific transcription factor, leads to HR cell death accompanied by the loss of plasma membrane integrity, nuclear DNA fragmentation and typical morphological changes. In OsNAC4 knock-down lines, HR cell death is markedly decreased in response to avirulent bacterial strains. After induction by an avirulent pathogen recognition signal, OsNAC4 is translocated into the nucleus in a phosphorylation-dependent manner. A microarray analysis showed that the expression of 139 genes including OsHSP90 and IREN, encoding a Ca2+-dependent nuclease, were different between the OsNAC4 knock-down line and control line during HR cell death. During the induction of HR cell death, OsHSP90 is involved in the loss of plasma membrane integrity, whereas IREN causes nuclear DNA fragmentation. Overall, our results indicate that two important events occurring during HR cell death are regulated by independent pathways