The impact of climatic conditions on the dynamics of tick-borne encephalitis in Slovakia in 2012-2016.

OBJECTIVES: The main aim of our work was to analyse the development of the dynamics of tick-borne encephalitis (TBE) in connection with climatic conditions in Slovakia in 2012-2016. MATERIAL AND METHODS: We performed the analysis based on the data provided by the Epidemiological Information System and the Slovak Hydrometeorological Institute. The study group consisted of 639 patients with confirmed diagnosis. RESULTS: The highest incidence of TBE was recorded in 2016. The highest standardized incidence rate of TBE was in the districts of the Trencín, Zilina and Banská Bystrica regions. The relation of TBE to air temperature showed that most cases of TBE were recorded at an air temperature of 10-20 °C during the months of May to October in 2012-2016. The relationship between air temperature and number of days with snow cover and the number of TBE cases proved to be statistically significant (p-value < 0.001). There is a statistically significant difference in the average number of disease cases according to the air temperature category (p-value = 0.03). This disease occurs mainly in districts with an altitude of 200-400 m a. s. l. The dynamics of TBE in Slovakia is two-peaked with a decline in August. The main season of the disease lasts from May to October, peaking during the summer months of June and July. CONCLUSION: The results of the study point to a prognosis of the development of the disease in connection with air temperature. Based on the findings that in recent years we have observed a slightly increasing trend of TBE in Slovakia due to climate change, this disease is considered a persistent public health problem.

Seasonal patterns of traumatic brain injury deaths due to traffic-related incidents in the Slovak Republic.

Objective: Traumatic Brain Injuries (TBIs) are an important type of injury in terms of both morbidity and mortality. Road Traffic Incidents are one of the most frequent causes of TBI. This analysis seeks to quantify the number of such injuries occurring in the Slovak Republic, and examine patterns of TBI according to mode of transport and seasonality.Methods: Data concerning total numbers of TBIs occurring from the years 1996-2015 were obtained from the Statistical Office of the Slovak Republic. The events caused by road incidents were examined separately according the external cause stated on death certification. Events were classified into seasons according to the month of death. Summary statistics were produced concerning numbers of deaths according to sex, mode of transport and season. Analyses were performed to examine trends in TBI by season and type of road user.Results: During a period of 20 years from 1996, there were 17,047 recorded deaths involving TBI in the Slovak Republic. Of these, 5,370 were caused by road traffic incidents (RTIs). Age standardized rates tended to decrease from 8.3/100,000/year (1996) to 2.5/100,000/year (2015). Males made up approximately 79% of road traffic-caused TBIs. Summer and autumn showed significantly more events than any other season, with motorcyclists and cyclists in particular being more frequently injured at this time of year.Conclusions: The results show that Slovakia, like many countries, suffers a considerable burden of TBI and that RTIs are a major contributor to this, especially among young adults. Rates of TBI vary by season in Slovakia, and users of different modes of transport appear more or less likely to suffer such injury during different seasons. Considerable variability in rates of injury exists between road users and times of year. Improved understanding of the timing and sufferers of injuries may allow better planning of response and care services. Further research into transport modes and policies aimed at safer driving should be explored.

[Quality of nephrolithiasis surgical treatment - what is it influenced by?] / Kvalita operacnej liecby nefrolitiázy: co na nu vplýva?

INTRODUCTION: Identifying factors effecting the quality of nephrolithiasis surgical treatment could improve medical care for patients suffering from kidney stone disease. The objective of the article is to identify factors influencing reintervention rate after surgical treatment of kidney stone disease either by percutaneous nephrolitholapaxy or flexible ureterorenoscopy. METHOD: A retrospective study was conducted on 149 patients who underwent a surgery for a kidney stone disease at the Urological department of F.D. Roosevelt hospital Banská Bystrica from January 2015 till June 2015. The cohort included 60 women at average age of 57 (range 28-91) and 89 men at average age of 58 (range 30-92). Patients were treated by percutaneous litholapaxy (67 cases) and flexible ureterorenoscopy (82 cases, including 72 using dusting technique). Factors with potential influence on probability of repeated intervention during following 12 months have been studied and statistically analyzed. For the statistical analysis we used the generalized linear regression framework (GLM Generalized Linear Model) with the stepwise forward modeling approach. RESULTS: Using the significance level of 5% the statistically significant factors affecting the probability of the re-intervention for ipsilateral kidney stone disease are the stone size (p-value 0.0035) and the postoperative stone free status (p-value 0.0418). Other studied factors as demographical data (age, gender), surgical method (percutaneous nephrolitolapaxy or flexible ureterorenoscopy), stone count, postoperative draining system (nefrostomy or JJ stent) did not have any statistically significant impact. CONCLUSION: Patients could benefit from early diagnosis which could lead to earlier identification of smaller stones. Perfect operative technique with intraoperative achievement of stone free status is important to lower the need of repeated intervention.Key words: kidney stone disease - reintervention residual fragments.

Feature clustering of intracranial pressure time series for alarm function estimation in traumatic brain injury.

OBJECTIVE: The conventional application of intracranial pressure (ICP) monitoring of traumatic brain injury (TBI) patients consists merely in the acquisition of ICP values in discrete time and their comparison to the established ICP threshold. An exceeding of this threshold triggers a special emergency treatment protocol. This paper addresses the possibility of making use of the rich information latent in the ICP records of known vital and fatal outcomes gathered during real clinical practice of treating TBI patients. Our assumption was that the proposed algorithmic procedure derived from this information could, in addition to ICP monitoring itself, provide a complementary added value. This might help clinicians to make better decisions during a patient's treatment. APPROACH: We concentrated on studying specific clustering schemes for subsequences of ICP time series. The clusterization problem was formulated for feature vectors which are introduced to represent ICP time subsequences. The ICP transformation to a feature space uses global and local definitions of time subsequences. For clusterization itself, we adopted hierarchical Gaussian mixture models (hGMMs). By using posterior probabilities of the clusters, we introduced three novel alarm functions. We explored two alternative methods of searching for optimum alarm function thresholds (ROC analysis and a novel efficiency measure). MAIN RESULTS: We performed extensive cross-validation experiments on a clinical retrospective data set. The results of the optimization over several hGMMs, various feature space dimensionality and all the types of the novel alarm functions show the potential of the novel alarm functions for supplementing conventional ICP monitoring. SIGNIFICANCE: In conclusion, the paper provides a prospective extended ICP monitoring technique for real TBI patients, based on the proposed methodology of ICP subsequence clustering and thresholding of the optimum novel alarm function.

Runx1 promotes proliferation and neuronal differentiation in adult mouse neurosphere cultures.

Traumatic brain injury alters the signaling environment of the adult neurogenic niche and may activate unique proliferative cell populations that contribute to the post-injury neurogenic response. Runx1 is not normally expressed by adult neural stem or progenitor cells (NSPCs) but is induced in a subpopulation of putative NSPCs after brain injury in adult mice. In order to investigate the role of Runx1 in NSPCs, we established neurosphere cultures of adult mouse subventricular zone NSPCs. We show that Runx1 is basally expressed in neurosphere culture. Removal of the mitogen bFGF or addition of 1% FBS decreased Runx1 expression. Inhibition of endogenous Runx1 activity with either Ro5-3335 or shRNA-mediated Runx1 knockdown inhibited NSPC proliferation without affecting differentiation. Lentiviral mediated over-expression of Runx1 in neurospheres caused a significant change in cell morphology without reducing proliferation. Runx1-overexpressing neurospheres changed from floating spheres to adherent colonies or individual unipolar or bipolar cells. Flow cytometry analysis indicated that Runx1 over-expression produced a significant increase in expression of the neuronal marker TuJ1 and a minor increase in the astrocytic marker S100ß. Thus, Runx1 expression drove adult NSPC differentiation, predominantly toward a neuronal lineage. These data suggest that Runx1 could be manipulated after injury to promote neuronal differentiation to facilitate repair of the CNS.

The impact of body mass index on severity, patterns and outcomes after traumatic brain injuries caused by low level falls.

PURPOSE: Low level falls are a common cause of traumatic brain injuries (TBI) and are associated with significant mortality and disability. The aim of this study was to analyse whether BMI, height and weight of patients were related to severity, patterns and outcomes of TBI caused by low level falls. METHODS: Data on patients with TBI where cause of injury was a low level fall (fall < 3 m) with known body mass index (BMI) (N = 683) were analysed. Patients were categorized into underweight, normal, pre-obese and obese based on BMI and demographic characteristics, injury severity, patterns and outcomes were compared. In addition, physiological status, comorbidities and length of hospitalization were analysed in a subset of patients where this information was available. RESULTS: The median BMI was 25.6. About 1/10 of patients were obese. The mean age and proportion of male sex of patients was increasing with increasing BMI. The patients in all BMI groups were of similar injury severity and neurological status. There was also no difference in mortality and functional outcome based on patient's BMI. Obese and pre-obese patients required longer stay at ICU and in hospital. CONCLUSION: We found no associations between BMI and severity or outcome of TBI caused by low level falls. More detailed data and further studies are needed to fully elucidate these complex relationships.

Timing and duration of intracranial hypertension versus outcomes after severe traumatic brain injury.

BACKGROUND: The goal of this paper was to investigate the association between patterns of intracranial hypertension (IH) and outcomes, to describe the treatment of patients with different patterns of IH, and to examine whether IH is an independent predictor of mortality and unfavourable outcome, respectively. METHODS: A retrospective analysis of data collected prospectively in 9 central European centers is presented. 204 patients with severe TBI who had intracranial pressure (ICP) monitoring were coded as having either early (within first 2 days), late (after first 2 days), or no IH. IH was defined as >60 min of ICP >20 mmHg/day. The total number of hours/day of IH was recorded. Treatment was followed closely for the first 10 days using the therapy intensity level (TIL) score. Associations between types of IH and demographic factors, trauma severity, or treatment factors as well as outcomes were analysed. RESULTS: Patients in the early IH group were the most severely injured. They had the highest TIL levels, had the highest mortality (48%) and the highest rate of unfavourable outcome (65%) followed by the late IH group (20% and 57%) and the no IH group (23% and 36%). Duration of IH correlated significantly with hospital mortality. IH was an independent predictor of mortality and unfavourable outcome after adjusting for age, Glasgow Coma Scale score, and Abbreviated Injury Score "head". CONCLUSION: Intracranial hypertension with early onset is independently associated with significantly worse outcome in patients with severe TBI. The total duration of IH shows a significant correlation to mortality.

Glasgow Coma Scale score at intensive care unit discharge predicts the 1-year outcome of patients with severe traumatic brain injury.

OBJECTIVE: To analyse the association between the Glasgow Coma Scale (GCS) score at intensive care unit (ICU) discharge and the 1-year outcome of patients with severe traumatic brain injury (TBI). DESIGN: Retrospective analysis of prospectively collected observational data. PATIENTS: Between 01/2001 and 12/2005, 13 European centres enrolled 1,172 patients with severe TBI. Data on accident, treatment and outcomes were collected. According to the GCS score at ICU discharge, survivors were classified into four groups: GCS scores 3-6, 7-9, 10-12 and 13-15. Using the Glasgow Outcome Scale (GOS), 1-year outcomes were classified as "favourable" (scores 5, 4) or "unfavourable" (scores <4). Factors that may have contributed to outcomes were compared between groups and for favourable versus unfavourable outcomes within each group. MAIN RESULTS: Of the 538 patients analysed, 308 (57 %) had GCS scores 13-15, 101 (19 %) had scores 10-12, 46 (9 %) had scores 7-9 and 83 (15 %) had scores 3-6 at ICU discharge. Factors significantly associated with these GCS scores included age, severity of trauma, neurological status (GCS, pupils) at admission and patency of the basal cisterns on the first computed tomography (CT) scan. Favourable outcome was achieved in 74 % of all patients; the rates were significantly different between GCS groups (93, 83, 37 and 10 %, respectively). Within each of the GCS groups, significant differences regarding age and trauma severity were found between patients with favourable versus unfavourable outcomes; neurological status at admission and CT findings were not relevant. CONCLUSION: The GCS score at ICU discharge is a good predictor of 1-year outcome. Patients with a GCS score <10 at ICU discharge have a poor chance of favourable outcome.

Maternal absence of the parathyroid hormone 2 receptor affects postnatal pup development.

During the lactation period, mothers have a variety of adaptive changes in brain physiology and behaviour that allow them to properly raise their pups. The exact circuitries and mechanisms responsible for these changes are not fully understood. Recent evidence suggests that the neuropeptide tuberoinfundibular peptide of 39 residues (TIP39) and its receptor, the parathyroid hormone 2 receptor (PTH2-R), contribute to these mechanisms. To further investigate this idea, we evaluated the growth rate of pups from dams with a genetically inactivated PTH2-R (PTH2-R-KO), as well as maternal behavioural and neuroendocrine parameters. We observed that PTH2-R-KO-reared pups had a slowed growth rate. This was associated with a reduced volume of milk yielded by PTH2-R-KO dams after 30-min suckling compared to wild-type (WT) dams when pups were returned after 5 h of separation. Our data suggest a reduced sensitivity of PTH2-R-KO dams to pup stimulation. We also observed a significant reduction in suckling-induced c-Fos expression in the paraventricular hypothalamic nucleus and signs of lower prolactin levels in the PTH2-R-KO dams. Our data suggest that the reduced growth rate of PTH2-R-KO-reared pups was likely the result of alterations in the milk-production pathway rather than modifications in behaviour. Although PTH2-R-KO dams showed increased anxiety in the elevated zero-maze test, no differences from WT dams in maternal behaviour were observed. Taken together, our findings suggest the involvement of the TIP39/PTH2-R system in the pathways involved in the successful development of the pups.

TIP39 modulates effects of novelty-induced arousal on memory.

Tuberoinfundibular peptide of 39 residues (TIP39) is a neuropeptide localized to neural circuits subserving emotional processing. Recent work showed that mice with null mutation for the gene coding TIP39 (TIP39-KO mice) display increased susceptibility to environmental provocation. Based on this stressor-dependent phenotype, the neuroanatomical distribution of TIP39, and knowledge that novelty-induced arousal modulates memory functions via noradrenergic activation, we hypothesized that exposure to a novel environment differently affects memory performance of mice with or without TIP39 signaling, potentially by differences in sensitivity of the noradrenergic system. We tested TIP39-KO mice and mice with null mutation of its receptor, the parathyroid hormone 2 receptor (PTH2-R), in tasks of short-term declarative and social memory (object recognition and social recognition tests, respectively), and of working memory (Y-maze test) under conditions of novelty-induced arousal or acclimation to the test conditions. Mice lacking TIP39 signaling showed memory impairment selectively under conditions of novelty-induced arousal. Acute administration of a PTH2-R antagonist in wild-type mice had a similar effect. The restoration of memory functions in TIP39-KO mice after injection of a ß-adrenoreceptor-blocker, propranolol, suggested involvement of the noradrenergic system. Collectively, these results suggest that the TIP39/PTH2-R system modulates the effects of novelty exposure on memory performance, potentially by acting on noradrenergic signaling.

One-year outcome and course of recovery after severe traumatic brain injury.

GOAL: To describe the outcome of patients with severe traumatic brain injury (TBI) 3, 6 and 12 months after trauma. METHODS: Between January 2001 and December 2005, 13 European centres enrolled 1,172 patients with severe TBI defined as Glasgow Coma Scale (GCS) score < 9. Demographic data, trauma severity, results of computed tomography (CT) scans, data on status, treatment and outcome were recorded. The five-level Glasgow Outcome Scale (GOS) score was used to classify patients as having a "favourable" (GOS scores 5 and 4) or an "unfavourable outcome" (GOS scores 3, 2 and 1). RESULTS AND CONCLUSIONS: Of the 1,172 patients, 37% died in the intensive care unit (ICU) and 8.5% died after ICU discharge. At 12 months after trauma, almost half of the outcomes (46.6%) were classified as "favourable" (33% "good recovery", 13.6% "moderate disability") and 7.9% were classified as "unfavourable" (6.1% "severe disability", 1.8% "vegetative status"). As in previous studies, long-term outcomes were influenced by age, severity of trauma, first GCS score, pupillary status and CT findings (e.g. subdural haematoma and closed basal cistern on the first CT scan). Patients with "good recovery" had a high likelihood to remain in that category (91%). Patients with "moderate disability" had a 50% chance to improve to "good recovery". Patients with "severe disability" had a 40% chance to improve and had a 4% chance of death. Patients with "vegetative status" were more likely to die (42%) than to improve (31%). Changes were more likely to occur during the first than during the second half-year after trauma.

Socioeconomic predictors of smoking behaviour among school-aged children, in the Slovakia.

OBJECTIVE: The aim of this study was to describe the relationship between smoking habits and socioeconomic determinants among adolescents. BACKGROUND: Tobacco use among young people is a formidable social health concern. The aim of this paper is to describe the situation in selected localities surveyed, and to elucidate the relations among experiments with tobacco in adolescent youth and behaviour of parents, friends and teachers and media influence. Thd objectives of this study are to describe patterns of self-reported smoking and to describe the association of trying smoking with other variables, such as social, or socio-demographics among a sample of young students. METHODS: Global Youth Tobacco Survey to track tobacco use among youth across countries using a common methodology and core questionnaire. In Slovakia, GYTS was carried out at the turn of 2002 to 2003. A total of 4.594 students participated in the study. RESULTS: The results indicate that the majority of the students (74.3%) have tried smoking where both parents are smokers. We found that gender, parents', friends' and teachers' smoking had a significant influence on whether the children ever tried smoking. A parent who smokes was found as a strong significant predictor for trying smoking in the group of students [OR = 1.6 (1.39-1.92)]. CONCLUSION: Predictors of smoking behaviour include parents', teachers' and friends' smoking. Public health interventions aim at conducting effective health promotion programs tailored to specific population groups and known predictors should be central to the design of such endeavours (Tab. 5, Ref. 18).

Evaluation of traumatic brain injury guidelines using AGREE instrument.

BACKGROUND: This study aims to assess the quality of four selected traumatic brain injuries management guidelines used mainly in the US and in Europe. METHODS: The instrument Appraisal of Guidelines Research & Evaluation was selected to provide a framework for guidelines appraisal. Four guidelines addressing a specific topic related to the treatment of traumatic brain injury were selected for evaluation: three developed in the United States of America and one from the United Kingdom. A trauma surgeon, one anaesthesiologist, one emergency physician and a public health specialist evaluated the guidelines. RESULTS: In the overall assessment of all guidelines, the United Kingdom guidelines attracted the best score, achieving the highest score of all four guidelines in five of six domains. The scientific quality of collected evidence was excellent and well documented in all four guidelines. Overall, the domains of Stakeholder involvement and Applicability were the lowest scoring for all the guidelines. CONCLUSION: A Broad spectrum of stakeholders should be represented in the brain trauma management guidelines development. The potential organizational and financial barriers for the application of guidelines need to be considered during their development. The paper provides suggestions for those who develop new guidelines for the management of patients with head injuries (Tab. 8, Ref. 29). Full Text (Free, PDF) www.bmj.sk.

New techniques for assessment of occupational respiratory diseases.

Recently, as several studies have demonstrated, these non-invasive techniques, such as induced sputum (IS) or analysis of the exhaled air; exhaled nitric oxide (eNO) or exhaled breath condensate (EBC) provide fairly reliable results that correlate with those of "gold standard" methods (bronchoscopy, bronchoalveolar lavage) which are more invasive and uncomfortable for patients. Although novel approaches have attracted the attention of scientists, they have not been examined in relation to occupational settings and professional diseases. The IS is a useful biological medium for the diagnosis of occupational asthma and for the assessment of exposures to harmful dust at workplaces. The eNO analysis can serve as an easy and comfortable diagnostic tool for the professional asthma after exposure to various allergens. The examination of EBC biomarkers evaluates local doses of hard metals in the lung, as well as detection of oxidative stress markers (malondialdehyde, H2O2). Due to the need to standardize the procedures for EBC collection, further studies on EBC validation and the subsequent application in the clinical and epidemiological fields are required. The techniques listed in this article may serve as optimal tools for diagnosis of occupational respiratory diseases and for screening/monitoring programs following inhalation exposures in future (ref 64).

Stakeholder approach in strengthening the patients' rights in the Slovak Republic.

OBJECTIVES: The described project aimed to promote patients' rights in the Slovak Republic that are stipulated by law but in practice not observed fully. BACKGROUND: The project was based on a bi-lateral agreement between The Netherlands and the Slovak Republic in the framework of European Union pre-accession program and implemented in the period from January 2002 to June 2003. METHODS: Successful Dutch models of patients' rights promotion were used. They were applied under Slovak conditions and focused on the areas in the greatest need of attention, such as information campaigning and public awareness of patients' rights issues. The initiation of a cooperation of various stakeholders active in healthcare and national patients' right forums was among the most positive aspects of the project. RESULTS: The information campaign was constructed in order to educate citizens about their entitlements and rights within healthcare. Healthcare professionals were trained on respecting the rights of their clients. Pilots were started in several hospitals and in Healthy City projects, and patients' rights modules were made available at educational centers and various private and health organizations. Some of the cooperating healthcare professionals expressed their fear that the public might misuse the gained advocacy skills. This idea has originated from the current situation in Slovak healthcare, where inadequate financing, education, and management is a barrier in the physician's ability to serve the patient's best interest. CONCLUSIONS: The implemented project started wide public discussion on patients' rights and stimulated a cooperation of a large number of stakeholders in the promotion of patients' rights (Tab. 2, Ref. 13). Full Text (Free, PDF) www.bmj.sk.

Functional expression of Candida antarctica lipase B in the Escherichia coli cytoplasm--a screening system for a frequently used biocatalyst.

In this paper, we report for the first time the functional expression of lipase B from the yeast Candida antarctica (CalB) in the Escherichia coli cytoplasm. The enzyme possessing three disulfide bonds was functionally expressed in the strain Origami B. Expression under the control of a lac promoter yielded 2 U mg(-1), whereas expression of a thioredoxin-CalB fusion protein yielded 17 U mg(-1). The native enzyme was most efficiently expressed under control of the cspA promoter (11 U mg(-1)). Coexpression of different chaperones led to a strong increase in active protein formation (up to 61 U mg(-1)). A codon-optimized synthetic variant of calb did not show significant effects on functional protein yield. Functional CalB expression was not only achieved in shake flasks but also in microtiter plate scale. Therefore, this CalB expression system is suitable for high-throughput applications, including the screening of large gene libraries as those derived from directed evolution experiments.

Long-term effects of ciliary neurotrophic factor on the survival of vasopressin magnocellular neurones in the rat supraoptic nucleus in vitro.

The use of hypothalamic organotypic cultures for the long-term study of mechanisms in magnocellular neurones (MCNs) of the hypothalamic-neurohypophysial system has been limited by the relatively poor maintenance of the vasopressin MCNs in vitro. Recent studies have shown that addition of ciliary neurotrophic factor (CNTF) to the media significantly reduced the apoptosis of both oxytocin and vasopressin MCNs. Here, we studied various temporal factors in the CNTF treatment that can influence the efficacy of MCN survival. Immunohistochemistry was used to identify and count surviving vasopressin and oxytocin MCNs in the supraoptic nucleus (SON) in hypothalamic slices cultured in the presence of CNTF (10 ng/ml media) for various time intervals, and in situ hybridization for vasopressin mRNA was used to evaluate the vasopressin mRNA gene expression in the SON under the same conditions. The presence of CNTF in the medium for 10 days produced a maximal increase in the survival of vasopressin MCNs (by 11-fold) and in the survival of oxytocin-MCNs (by approximately four-fold) over controls. These effects persisted for an additional 7-10 days even in the absence of CNTF. The ability of CNTF to increase survival of the MCNs or increase vasopressin mRNA levels in the SON required that the CNTF be present during the initial 7-10 days of culture. CNTF failed to rescue vasopressin or oxytocin MCNs when added to the media only for the last 7 days of a total of 14 days in vitro. Similar results were observed when SON vasopressin mRNA levels were measured. These results indicate that the presence of CNTF is required at the outset to rescue the vasopressin and oxytocin MCN from axotomy induced apoptosis, and that, after 10 days in CNTF, the MCNs no longer require the CNTF for survival.

Effect of novel stressors on tyrosine hydroxylase gene expression in the adrenal medulla of repeatedly immobilized rats.

The activity of the sympathetic-adrenomedullary system in rats submitted to novel stressors after prior repeated or chronic stress exposure is poorly understood. The purpose of the present work was to investigate changes in adrenomedullary (AM) tyrosine hydroxylase (TH) gene expression after a single or long-term repeated exposure of rats to immobilization stress (IMMO; 42 times), as well as in repeatedly immobilized rats (41 times) exposed once to various novel heterotypic stressors. Cold exposure for 5 h, administration of insulin (INS, 51U), or 2-deoxyglucose (2DG, 500 mg/kg) were used as novel stressors. A single exposure to cold, INS, or 2DG produced transient increases in TH mRNA levels in AM. Animals exposed to repeated homotypic IMMO stress showed permanently increased TH mRNA levels, TH activity, and protein levels; however, an exposure of such animals to heterotypic novel stressors did not induce any further changes. Thus the observed differences in TH mRNA levels in the AM of control rats and long-term repeatedly IMMO rats suggest that an adaptation to this stressor is displayed by a permanently increased TH gene expression, TH activity, and protein level. The exposure of repeatedly IMMO rats to a single episode of novel stressor does not induce exaggerated responses in TH gene expression, as some other stressors do. The mechanism of this finding could involve a central regulation and/or adrenomedullary signaling pathway(s), leading to additional modifications or accumulation of transcription factors. The precise mechanism(s) of this phenomenon remains to be elucidated.

The magnocellular neuronal phenotype: cell-specific gene expression in the hypothalamo-neurohypophysial system.

The magnocellular oxytocin (OT) and vasopressin (VP) neurons of the hypothalamo-neurohypophysial system are exceptional cell biological models to study mechanisms of cell-specific gene expression and neurosecretion of neuropeptides in the central nervous system. Single cell differential gene expression experiments have further defined these phenotypes by identifying novel and distinct regulatory molecules in these neurons. Transgenic mouse studies have led to the intergenic region (IGR) hypothesis, which states that the DNA sequences between the OT- and VP-genes contain critical enhancer sites for their cell-specific expression. The recent cloning and sequencing of the human IGR, and its comparison with the mouse IGR sequence has identified conserved sequences as putative, cell-specific enhancer sites which are now being evaluated by biolistic transfections of organotypic hypothalamic cultures. With these data, it is possible to target the gene expression of specific molecules to magnocellular neurons both in vivo and in vitro, in order to perturb and/or visualize neurosecretory and other processes.

Stress increases gene expression of phenylethanolamine N-methyltransferase in spleen of rats via pituitary-adrenocortical mechanism.

Gene expression of phenylethanolamine N-methyltransferase (PNMT), the enzyme catalyzing conversion of norepinephrine to epinephrine, has been detected in rat spleen using the reverse transcription polymerase chain reaction. PNMT identity was subsequently verified by Southern blots. Localization of the spleen cells responsible for the PNMT gene expression was investigated by the in situ hybridization and PNMT mRNA was found to be present in the white pulp. The hypothesis that stress may produce an increase in PNMT gene expression in rat spleen was tested and a robust rise in the relative abundance of PNMT mRNA levels was observed after a single or repeated immobilization (about 80%). Adrenalectomy or hypophysectomy completely prevented the immobilization-induced increase in spleen PNMT mRNA levels, suggesting that stress-induced PNMT gene expression in the spleen is regulated predominantly via pituitary-adrenocortical axis. In control animals, however, spleen PNMT was not significantly affected by the ectomies and therefore basal PNMT gene expression might be regulated by different mechanism(s).Thus, PNMT gene expression in the rat spleen is exaggerated by stress stimuli, suggesting its role in physiological regulations.