Placental lactogens induce serotonin biosynthesis in a subset of mouse beta cells during pregnancy

AIMS/HYPOTHESIS: Upregulation of the functional beta cell mass is required to match the physiological demands of mother and fetus during pregnancy. This increase is dependent on placental lactogens (PLs) and prolactin receptors, but the mechanisms underlying these events are only partially understood. We studied the mRNA expression profile of mouse islets during pregnancy to gain a better insight into these changes. METHODS: RNA expression was measured ex vivo via microarrays and quantitative RT-PCR. In vivo observations were extended by in vitro models in which ovine PL was added to cultured mouse islets and MIN6 cells. RESULTS: mRNA encoding both isoforms of the rate-limiting enzyme of serotonin biosynthesis, tryptophan hydroxylase (TPH), i.e. Tph1 and Tph2, were strongly induced (fold change 25- to 200-fold) during pregnancy. This induction was mimicked by exposing islets or MIN6 cells to ovine PLs for 24 h and was dependent on janus kinase 2 and signal transducer and activator of transcription 5. Parallel to Tph1 mRNA and protein induction, islet serotonin content increased to a peak level that was 200-fold higher than basal. Interestingly, only a subpopulation of the beta cells was serotonin-positive in vitro and in vivo. The stored serotonin pool in pregnant islets and PL-treated MIN6 cells was rapidly released (turnover once every 2 h). CONCLUSIONS/INTERPRETATION: A very strong lactogen-dependent upregulation of serotonin biosynthesis occurs in a subpopulation of mouse islet beta cells during pregnancy. Since the newly formed serotonin is rapidly released, this lactogen-induced beta cell function may serve local or endocrine tasks, the nature of which remains to be identified

Effects of Acute Tryptophan Depletion on Brain Serotonin Function and Concentrations of Dopamine and Norepinephrine in C57BL/6J and BALB/cJ Mice

Acute tryptophan depletion (ATD) is a method of lowering brain serotonin (5-HT). Administration of large neutral amino acids (LNAA) limits the transport of endogenous tryptophan (TRP) across the blood brain barrier by competition with other LNAAs and subsequently decreases serotonergic neurotransmission. A recent discussion on the specificity and efficacy of the ATD paradigm for inhibition of central nervous 5-HT has arisen. Moreover, side effects such as vomiting and nausea after intake of amino acids (AA) still limit its use. ATD Moja-De is a revised mixture of AAs which is less nauseating than conventional protocols. It has been used in preliminary clinical studies but its effects on central 5-HT mechanisms and other neurotransmitter systems have not been validated in an animal model. We tested ATD Moja-De (TRP−) in two strains of mice: C57BL/6J, and BALB/cJ, which are reported to have impaired 5-HT synthesis and a more anxious phenotype relative to other strains of mice. ATD Moja-De lowered brain TRP, significantly decreased 5-HT synthesis as indexed by 5-HTP levels after decarboxlyase inhibition, and lowered 5-HT and 5-HIAA in both strains of mice, however more so in C57BL/6J than in BALB/cJ. Dopamine and its metabolites as well as norepinephrine were not affected. A balanced (TRP+) control mixture did not raise 5-HT or 5-HIAA. The present findings suggest that ATD Moja-De effectively and specifically suppresses central serotonergic function. These results also demonstrate a strain- specific effect of ATD Moja-De on anxiety-like behavior

The role of rewards and demands in burnout among surgical nurses

Job rewards have both, an intrinsic and an extrinsic motivational potential, and lead to employees’ development as well as help them to achieve work goals. Rewards can balance job demands and protect from burnout. Due to changes on the labour market, new studies are needed. The aim of our study was to examine the role of demands and individual rewards (and their absence) in burnout among surgical nurses. Materials and Methods: The study was conducted in 2009 and 2010 with 263 nurses who worked in surgical wards and clinics in hospitals in Southern Poland. The hypotheses were tested by the use of measures of demands and rewards (Effort-Reward Imbalance Questionnaire by Siegrist) and burnout syndrome (Maslach Burnout Inventory). A cross-sectional, correlational study design was applied. Results: Nurses experienced the largest deficiencies in salary and prestige. Exhaustion was explained by stronger demands and lack of respect (large effect). Depersonalization was explained by stronger demands, lack of respect and greater job security (medium effect). Reduced personal achievement was explained by more demands and greater job security (small effect). Conclusions: Excessive demands and lack of esteem are key reasons for burnout among surgical nurses. Job security can increase burnout when too many resources are invested and career opportunities do not appear. These results may help to improve human resource management in the healthcare sector

Resource Use in Treating Alcohol- and Drug-related Diagnoses: Does Teaching Status and Experience Matter?

OBJECTIVE: This study examined the variations in hospital resource use in the treatment of alcohol and drug diagnoses. Specifically, the study tested 2 hypotheses: 1) patients treated in teaching hospitals will have shorter lengths of stay and lower hospital charges than patients treated in nonteaching hospitals; and 2) patients treated in hospitals with more experience treating these conditions will have shorter lengths of stay and lower hospital charges. DESIGN: A retrospective cross-sectional study design used data from the 1996 Health Care Utilization Project to test the proposed hypotheses. PATIENTS/PARTICIPANTS: The population for this study consisted of patients over 18 years old with an acute alcohol- or drug-related discharge diagnostic related group code. MEASUREMENT AND MAIN RESULTS: The variables of interest were teaching hospital status, as defined by the Council of Teaching Hospitals, and hospital experience, defined as the ratio of alcohol- and drug-related diagnoses to the hospital's total admissions. Measures of hospital resource use included the patient's length of stay and total hospital charges. Patients treated at hospitals with relatively more experience in treating alcohol- and drug-related diagnoses had 10.3% ($321) lower total charges (P = .017). CONCLUSIONS: Similar to research for high-volume surgical hospitals, these findings confirm that hospitals that have greater experience with complex medical conditions such as alcohol and drug intoxication and withdrawal may be more efficient. This important finding provides a rationale for further exploration of the key factors associated with higher quality and more efficient care for complex medical conditions

Web-based Curriculum: A Practical and Effective Strategy for Teaching Women's Health

OBJECTIVE: To address the need for women's health education by designing, implementing, and evaluating a self-study, web-based women's health curriculum. DESIGN: Cohort of students enrolled in the ambulatory portion of the medicine clerkship with comparison group of students who had not yet completed this rotation. PARTICIPANTS/SETTING: Third- and fourth-year medical students on the required medicine clerkship (115 students completed the curriculum; 158 completed patient-related logs). INTERVENTION: Following an extensive needs assessment and formulation of competencies and objectives, we developed a web-based women's health curriculum completed during the ambulatory portion of the medicine clerkship. The modules were case based and included web links, references, and immediate feedback on posttesting. We discuss technical issues with implementation and maintenance. MEASUREMENTS AND MAIN RESULTS: We evaluated this curriculum using anonymous questionnaires, open-ended narrative comments, online multiple-choice tests, and personal digital assistant (PDA) logs of patient-related discussions of women's health. Students completing the curriculum valued learning women's health, preferred this self-directed learning over lecture, scored highly on knowledge tests, and were involved in more and higher-level discussions of women's health with faculty (P <.001). CONCLUSIONS: We present a model for the systematic design of a web-based women's health curriculum as part of a medicine clerkship. The web-based instruction resolved barriers associated with limited curriculum time and faculty availability, provided an accessible and standard curriculum, and met the needs of adult learners (with their motivation to learn topics they value and apply this knowledge in their daily work). We hypothesize that our web-based curriculum spurred students to later discuss these topics with faculty. Web-based learning may be particularly suited for women's health because of its multidisciplinary nature and need for vertical integration throughout medical school curricula