The degenerative fate of germ cells not conforming to stage in the pubertal golden hamster testis

In the golden hamster ( Mesocricetus auratus ), pubertal establishment of spermatogenesis includes a defined period (d 26–30 of life) during which elongation of spermatids is selectively arrested. The resulting appearance of germ cell associations not conforming to stage and the phenomenon of desynchronisation-related germ cell degeneration are analysed both quantitatively and qualitatively by means of light and 'retrospective' electron microscopy. From d 26 onwards, the portion of tubules containing non-stage conforming germ cell associations gradually increases up to 37.5% of sectioned tubules on d 32. Concomitantly, the degree of desynchronisation rises to a maturational gap between spermatids and associated younger germ cells of 7 stages of the seminiferous epithelium cycle, i.e. of fully half a cycle. Beyond d 32, the frequency of desynchronised tubule segments decreases again. Some of the arrested round spermatids and, eventually, all belatedly elongating spermatids degenerate and are lost from the epithelium. Thus a regular maturation of advanced spermatids does not succeed under non-stage conforming conditions. Possibly it is not the desynchronisation between the associated germ cell generations and the spermatids by itself that impedes normal further development of the latter cells. Instead this may be due to the maturational delay of the stage-aberrant cells by several stages compared to the seminiferous epithelium as a whole and, especially, in relation to the stage-conditioned functional state of the neighbouring Sertoli cells.     

Slug is overexpressed in gastric carcinomas and may act synergistically with SIP1 and Snail in the down-regulation of E-cadherin

Epithelial-mesenchymal transition (EMT) involving down-regulation of E-cadherin is known to play an important role in tumour progression. The aim of our study was to investigate the mRNA expression of two EMT regulators-Slug and E12/E47-in primary human gastric carcinomas and to compare this with the expression of E-cadherin and other EMT regulators (Snail, Twist, and SIP1). We studied a series of 59 gastric carcinomas by real-time quantitative RT-PCR in formalin-fixed and paraffin-embedded tissues. Thirty-four cases (58%) showed Slug up-regulation in the tumour; reduced or negative expression of E-cadherin was present in 24 of these (71%, p<0.0001). Twenty-one cases (36%) showed E12/E47 up-regulation that was not significantly associated with E-cadherin down-regulation (p=0.5734). Slug up-regulation accompanied by E-cadherin down-regulation correlated with the presence of distant metastases (p=0.0029) and with advanced pTNM stages (p=0.0424). A statistically significant association was found between Slug up-regulation and the expression of SIP1 in intestinal (p=0.0014) and Snail in diffuse (p=0.0067) carcinomas. We present the first study integrating the analysis of several EMT regulators in primary gastric carcinomas and conclude that Slug up-regulation is associated with E-cadherin down-regulation in diffuse and intestinal-type gastric carcinoma, and that this effect could be complemented by the presence of other EMT regulators.     

Response to a telemedicine inquiry from the Florida House of Representatives and text of model act to regulate the practice of telemedicine.

This past summer, the Federation of State Medical Boards (FSMB) drafted model legislation on the practice of medicine across state lines and sent it to each state medical board for consideration. The Florida House of Representatives Committee on Business and Professional Regulation posed a series of questions about telemedicine covering issues of licensure, malpractice, insurance reimbursement, technology, physician interest and acceptance, quality of care, and cost benefit. The author's responses having been modified for this article, are presented, as is the model legislation. Appendix I is the Executive Summary of the FSMB. Appendix II is the model legislation.     

Protein 4.1 family and ion channel proteins interact to regulate the process of heart failure in rats

Heart failure (HF) is a major cause of death in cardiovascular diseases worldwide, and its molecular mechanisms and effective prevention strategies remain to be further studied. The myocardial cytoskeleton plays a pivotal role in many heart diseases. However, little is known about the function of the membrane cytoskeleton 4.1 protein family and related regulatory mechanisms in the pathogenesis of HF. In this study, we detected the localization and expression of the protein 4.1 family and ion channel proteins in a rat HF model induced by doxorubicin (DOX), and studied the interactions between them. Our results showed that compared with the control group, the HF group displayed an increased expression level of protein 4.1R and decreased levels of protein 4.1 G and 4.1 N. The Nav1.5 protein levels were significantly increased, while the SERCA2a and Cav1.2 protein levels were significantly decreased in the HF group. Furthermore, there is co-localization and interaction between protein 4.1R and Nav1.5, protein 4.1 G and SERCA2a, protein 4.1 N and Cav1.2, respectively. Taken together, the results indicated that the protein 4.1 family might be involved in the occurrence and development of HF through its interaction with ion channel proteins, suggesting that 4.1 proteins may serve as a novel therapeutic target for HF.     

CNTN-1 promotes docetaxel resistance and epithelial-to-mesenchymal transition via the PI3K/Akt signaling pathway in prostate cancer

IntroductionTherapy options for prostate cancer (PCa) typically are centered on docetaxel-based chemotherapy but are limited by the effects of multi-drug resistance. Recent advances have illustrated a role of contactin-1 (CNTN-1) in tumor chemoresistance, while the function and mechanism of CNTN-1 in the resistance of docetaxel in prostate cancer have not yet been elucidated.Material and methodsDocetaxel (Dox)-resistant PCa cell lines of PC3 (PC3-DR) and DU145 (DU145-DR) were established, and short hairpin RNA (shRNA) constructs targeting CNTN-1 were generated to analyze the effect of knockdown of CNTN-1 on PCa progression. Cell Counting Kit-8 (CCK-8), flow cytometry, wound-healing, transwell and western blotting analysis were used to analyze cell proliferation, apoptosis, migration, invasion and related protein expression levels, respectively.ResultsKnockdown of CNTN-1 in PC3-DR and DU145-DR cells attenuated cell proliferation, migration, invasion, EMT phenotype, and drug resistance, and increased cell apoptosis further reduced the tumorigenic phenotype. Knockdown of CNTN-1 resulted in an anti-tumor effect in the xenograft tumor model, and decreased activity of the phosphoinositide 3-kinase (PI3K)/Akt signaling pathway both in vitro and in vivo.ConclusionsThe results of the present study suggest that downregulation of CNTN-1 may be an important mechanism to reverse chemoresistance in Dox-resistant PCa progression, thus shedding light on the development of novel anti-tumor therapeutics for the treatment of PCa.     

The CLN3/SWI6/CLN2 pathway and SNF1 act sequentially to regulate meiotic initiation in Saccharomyces cerevisiae

BACKGROUND: IME1, which is required for the initiation of meiosis, is regulated by Cln3:Cdc28 kinase, which activates the G1-to-S transition, and Snf1 kinase, which mediates glucose repression. Here we examine the pathway by which Cln3:Cdc28p represses IME1 and the relationship between Cln3:Cdc28p and Snf1p in this regulation. RESULTS: When wild-type yeast cease growth, they express IME1 to moderate levels, intermediate between the low levels expressed during growth and the high levels expressed during sporulation. Moderate IME1 expression occurred in cln3Delta, cln1Delta cln2Delta, cdc28-4 and swi6Delta mutants, even during growth. These mutants also induced IME1 expression more rapidly than the wild-type. CLN3 required SWI6 and CLN2 to repress IME1 and IME2, but CLN1 was much less active than CLN2 in this repression. The phenotype of the cln3Delta snf1Delta double mutant indicated that Cln3:Cdc28p regulates IME1 independently of SNF1. CONCLUSION: Entry into meiosis involves two independent but sequential controls, which regulate IME1 via a three position switch: (i) during growth IME1 is repressed by the CLN3/SWI6/CLN2 pathway, (ii) once growth ceases, this repression is released and IME1 is expressed at moderate levels, and (iii) subsequently, nutritional conditions that activate Snf1p allow high IME1 expression.     

Personality disorder traits during adolescence and relationships with family members during the transition to adulthood

Data from the Children in the Community Transitions Study, a prospective longitudinal investigation, were used to examine the association between adolescent personality disorder (PD) traits and conflict with family members during the transition to adulthood. PD traits at mean age 16 years were associated with elevated contact and conflict with family members between ages 17 and 27 years after Axis I disorders were controlled. There was a significant association between frequent contact and elevated conflict with family members. Both declined gradually during the transition to adulthood. Reduced family contact was associated with reduced family conflict, particularly among individuals who had numerous PD traits during adolescence. Among individuals who had a high level of family conflict during adolescence, reduced family contact between ages 17 and 22 years was associated with a subsequent reduction in conflict with family members between ages 22 and 27 years.     

Children's appraisal and coping with pain: relation to maternal ratings of worry and restriction in family activities

OBJECTIVE: To examine the relation of children's pain severity, perceived pain threat, and passive coping to maternal worry and family activities. METHODS: We assessed pain severity, perceived threat (conceptualized as beliefs about pain seriousness and coping ability), and coping strategies in 130 patients with chronic abdominal pain. Mothers rated the impact of the child's health on maternal worry and family activities. RESULTS: Controlling for pain severity, higher pain threat was associated with maternal reports of greater worry and limitations in family activities due to the child's health. Children's use of passive-coping strategies was not related to maternal worry or family activity limitations. CONCLUSIONS: Health care providers should assess patients' pain beliefs, correct misperceptions about pain seriousness, and help increase patients' perceived efficacy in coping with pain.     

The role of retinoblastoma protein family in the control of germ cell proliferation,differentiation and survival

Retinoblastoma family proteins pRb, p107 and p130 are differentially expressed in the rat testis. They function in specific cell types during testicular development and spermatogenesis, participating in the control of proliferation, differentiation, and survival. Their expression levels and phosphorylation status are modulated during germ cell cycle progression and apoptosis. Hyperphosphorylated states and elevated levels of p107 are correlated with cell cycle progression, whereas hypophosphorylated states and reduced levels are associated with suppression of proliferation and apoptosis in germ cells and Leydig cells. These proteins may also serve as markers of cell cycle status of germ cells during spermatogenesis.     

Two relatively distinct patterns of ameloblastoma: an anti-apoptotic proliferating site in the outer layer (periphery) and a pro-apoptotic differentiating site in the inner layer (centre)

AIMS: This study was performed to determine the apoptotic behaviour of ameloblastomas by analysing the role of bcl-2 family proteins in ameloblastomas and the location of terminally apoptotic cells in the ameloblastoma epithelial tissues. METHODS AND RESULTS: For immunohistochemistry, tissue sections of 32 patients were treated with an antigen-retrieval METHOD: Primary antibodies against the apoptosis-related proteins, bcl-2, bcl-X, bax, and bak were applied. Besides immunohistochemistry, Western blotting and TUNEL were also performed. Most of the outer layer cells were predominantly stained by the bcl-2 antibody, while most of the inner layer cells were stained by antibodies against the apoptosis-modulating proteins, bax and bak. Among the bcl-2 family, bcl-2 was the most ubiquitously expressed protein in ameloblastomas, while bcl-X was expressed in the greatest concentrations. The major bcl-X protein was bcl-XL. Some of the inner layer cells entered the terminal apoptotic stage, which were revealed by TUNEL. The acanthomatous areas over-expressed the apoptosis-modulating proteins, especially bak. CONCLUSIONS: Ameloblastoma has much more apoptosis-inhibiting protein than the apoptosis-modulating protein. Ameloblastoma has two relatively distinct patterns, an anti-apoptotic proliferating site in the outer layer (periphery) and a pro-apoptotic differentiating site in the inner layer (centre). The acanthomatous area, which was stained strongly by bak antibody and contained numerous terminally apoptotic cells, was considered as the differentiated area.     

A nucleostemin family GTPase, NS3, acts in serotonergic neurons to regulate insulin signaling and control body size

Growth and body size are regulated by the CNS, integrating the genetic developmental program with assessments of an animal's current energy state and environmental conditions. CNS decisions are transmitted to all cells of the animal by insulin/insulin-like signals. The molecular biology of the CNS growth control system has remained, for the most part, elusive. Here we identify NS3, a Drosophila nucleostemin family GTPase, as a powerful regulator of body size. ns3 mutants reach <60% of normal size and have fewer and smaller cells, but exhibit normal body proportions. NS3 does not act cell-autonomously, but instead acts at a distance to control growth. Rescue experiments were performed by expressing wild-type ns3 in many different cells of ns3 mutants. Restoring NS3 to only 106 serotonergic neurons rescued global growth defects. These neurons are closely apposed with those of insulin-producing neurons, suggesting possible communication between the two neuronal systems. In the brains of ns3 mutants, excess serotonin and insulin accumulate, while peripheral insulin pathway activation is low. Peripheral insulin pathway activation rescues the growth defects of ns3 mutants. The findings suggest that NS3 acts in serotonergic neurons to regulate insulin signaling and thus exert global growth control.