Dopamine and serotonin: influences on male sexual behavior

Steroid hormones regulate sexual behavior primarily by slow, genomically mediated effects. These effects are realized, in part, by enhancing the processing of relevant sensory stimuli, altering the synthesis, release, and/or receptors for neurotransmitters in integrative areas, and increasing the responsiveness of appropriate motor outputs. Dopamine has facilitative effects on sexual motivation, copulatory proficiency, and genital reflexes. Dopamine in the nigrostriatal tract influences motor activity; in the mesolimbic tract it activates numerous motivated behaviors, including copulation; in the medial preoptic area (MPOA) it controls genital reflexes, copulatory patterns, and specifically sexual motivation. Testosterone increases nitric oxide synthase in the MPOA; nitric oxide increases basal and female-stimulated dopamine release, which in turn facilitates copulation and genital reflexes. Serotonin (5-HT) is primarily inhibitory, although stimulation of 5-HT(2C) receptors increases erections and inhibits ejaculation, whereas stimulation of 5-HT(1A) receptors has the opposite effects: facilitation of ejaculation and, in some circumstances, inhibition of erection. 5-HT is released in the anterior lateral hypothalamus at the time of ejaculation. Microinjections of selective serotonin reuptake inhibitors there delay the onset of copulation and delay ejaculation after copulation begins. One means for this inhibition is a decrease in dopamine release in the mesolimbic tract.     

Evidence of the monoclonal composition of human endometrial epithelial glands and mosaic pattern of clonal distribution in luminal epithelium

The endometrium is a highly regenerative tissue that plays a crucial role in implantation. We examined the clonal constitution of glandular cells as well as the luminal epithelium of this unique tissue. Using collagenase-based digestion techniques with microscopic manipulation, we isolated individual human endometrial glands and examined their clonality using a polymerase chain reaction-based assay for nonrandom X chromosome inactivation with an X-linked androgen receptor gene. Most of the glands analyzed were composed of monoclonal populations of epithelial cells and one of the glands exhibited a loss of heterogeneity in the androgen receptor gene. In addition, adjacent glands within a 1-mm(2) area shared clonality, suggesting that clonality of the luminal epithelium is regionally defined. The clonality of endometrium was further confirmed in a study of female mice that harbor the green fluorescent protein gene on either the maternal or paternal X chromosome. Fluorescent microscopy of uterine sections revealed that individual endometrial glands consisted completely of either fluorescent or nonfluorescent cells and that the surface epithelium exhibited a clear boundary between these cell types. These findings suggest that single or multiple stem cells with uniform clonality exist on the bottom of each endometrial gland and genetic alterations occurring in such cells may play a critical role in endometrial carcinogenesis. The possible association between area-specific X inactivation of the endometrial surface and the endometrial receptivity of embryo implantation remains to be clarified.     

VDE-initiated intein homing in Saccharomyces cerevisiae proceeds in a meiotic recombination-like manner

BACKGROUND: Inteins and group I introns found in prokaryotic and eukaryotic organisms occasionally behave as mobile genetic elements. During meiosis of the yeast Saccharomyces cerevisiae, the site-specific endonuclease encoded by VMA1 intein, VDE, triggers a single double-strand break (DSB) at an inteinless allele, leading to VMA1 intein homing. Besides the accumulating information on the in vitro activity of VDE, very little has been known about the molecular mechanism of intein homing in yeast nucleus. RESULTS: We developed an assay to detect the product of VMA1 intein homing in yeast genome. We analysed mutant phenotypes of RecA homologs, Rad51p and Dmc1p, and their interacting proteins, Rad54p and Tid1p, and found that they all play critical roles in intein inheritance. The absence of DSB end processing proteins, Sae2p and those in the Mre11-Rad50-Xrs2 complex, also causes partial reduction in homing efficiency. As with meiotic recombination, crossover events are frequently observed during intein homing. We also observed that the absence of premeiotic DNA replication caused by hydroxyurea (HU) or clb5delta clb6delta mutation reduces VDE-mediated DSBs. CONCLUSION: The repairing system working in intein homing shares molecular machinery with meiotic recombination induced by Spo11p. Moreover, like Spo11p-induced DNA cleavage, premeiotic DNA replication is a prerequisite for a VDE-induced DSB. VMA1 intein thus utilizes several host factors involved in meiotic and recombinational processes to spread its genetic information and guarantee its progeny through establishment of a parasitic relationship with the organism.     

Association of feces sign with prognosis of non-emergency adhesive small bowel obstruction

Background/Objective: The feces sign has been reported as a possible predictive factor for non-operative treatment of small bowel obstruction. However, its relationship with prognosis of non-emergency adhesive small bowel obstruction remains unclear. This study aimed to clarify the relationship between the feces sign and prognosis of non-emergency adhesive small bowel obstruction.MethodsNinety-two patients with non-emergency adhesive small bowel obstruction with the transitional zone visible on computed tomography were included. Patients were categorized into two groups: feces sign positive (n = 40) and negative (n = 52). Clinical features and prognosis were compared between the two groups. Cox proportional hazards regression models incorporating the feces sign were used to analyze odds of diet resumption and discharge.ResultsPatients with feces sign were younger (p = 0.015), had a higher body mass index (p = 0.027), and a lower white blood cell count (p = 0.019) on admission. More patients with feces sign were successfully treated with fasting and/or nasogastric tube placement (p < 0.001), and no patient with feces sign suffered from recurrent obstruction after diet resumption. Kaplan–Meier analysis showed that patients with feces sign took less time for diet resumption (p = 0.007) and discharge (p = 0.004) than those without it. Using Cox proportional hazards regression model, the feces sign was reported as an independent predictor of diet resumption (odds ratio 1.685, p = 0.018) and discharge (odds ratio 1.861, p = 0.007).ConclusionsThe feces sign is associated with improved odds for diet resumption and discharge.     

The association between renal elasticity evaluated by Real-time tissue elastography and renal fibrosis

Clinical and Experimental Nephrology - The progression of chronic kidney disease (CKD) depends on the extent of fibrosis in the kidneys; however, a renal biopsy is necessary to evaluate the...     

Safety and efficacy of Tolvaptan in real-world patients with autosomal dominant polycystic kidney disease- interim results of SLOW-PKD surveillance

Clinical and Experimental Nephrology - Tolvaptan is a vasopressin type 2 receptor antagonist and has been used to treat autosomal dominant polycystic kidney disease (ADPKD) since 2014. There has...