Relationship between milk constituents from milk testing and health, feeding, and metabolic data of dairy cows.

A new evaluation scheme to assess the nutritional status of dairy cows on the basis of milk constituents was derived from 7.37 million German records of milk testing. The aim of this work was to validate this new scheme. Two data sets with fertility and health information (data set A) and with measured energy and nutrient intake and metabolic characteristics (data set B) were analyzed. Data set A included 32 commercial dairy farms in northeast Germany, with 72,982 records of 43,863 German Holstein cows; data set B included 12 German experimental farms, with 49,275 records of 1,650 German Holstein, Simmental, and Brown Swiss cows. Milk traits were linked to health disorders and metabolic and feeding characteristics. Frequently used limits of milk constituents were compared with ranges of the new "Dummerstorf feeding evaluation." To distinguish an optimal from a deficient energy supply, a milk protein content ≥3.20% (previously used) and a milk fat:protein ratio (FPR) ≤1.4 (new scheme) were chosen and compared with feed energy intake in relation to demand. Energy status was more often correctly assigned by FPR than by milk protein content (80.7 and 68.7%, respectively). Over all data, the new optimum range of milk urea between 150 and 250 mg/L was better suited to dietary crude protein intake in relation to demand than the previously used range of 150 to 300 mg/L (42.4 and 38.0%, respectively). Ketosis or blood values associated with ketosis such as ß-hydroxybutyrate >1.2 mmol/L or nonesterified fatty acids >1,000 µmol/L, as well as strong mobilization of body weight ≥1.5 kg/d, loss of back fat thickness ≥10 mm, and loss of body condition score ≥1 unit in first 60 days in milk were compared with different milk trait thresholds. For the updated scheme FPR >1.4 was used in combination with either milk protein content below the individual statistical lower limit of milk protein content, or milk fat content greater than the individual statistical upper limit of milk fat content; FPR >1.5 was taken as a frequently used threshold. For these ketosis indicators, the new scheme had higher sensitivities. Energy oversupply or the risk of overconditioning could not be identified by milk constituents alone. Urinary acid-base content was not related to milk content. Similarly, milk testing data did not allow a clear distinction to be made between the diagnoses of acidosis and, for example, ketosis. Essential requirements for good herd management are the continuous observation of milk testing data in combination with other established instruments of feeding and animal monitoring.

Associations between Streptococcus uberis strains from the animal environment and clinical bovine mastitis cases.

Bovine clinical mastitis quarter foremilk samples were collected from 15 German dairy farms for the isolation of Streptococcus uberis strains. Samples were also collected from the 8 spots where Streptococcus uberis was most expected in the dairy environment to investigate the transmission behavior of Streptococcus uberis within the farm. The selected environmental spots for sampling were the inner surface of the milking liner, drinking troughs (on pasture and in the barn), exit area of milking parlor, bedding material from the lying area in the barn, passageway to pasture, lying area of soil or vegetation on pasture, and the barn area in front of the milking parlor. We performed pulsed-field gel electrophoresis on 237 Streptococcus uberis isolates to identify environmental strains that matched those from mastitis milk. The same strains were detected on the passageway to the pasture, milking parlor waiting area, in one of the liners, and a drinking trough. Streptococcus uberis strains showed high variability within farms and because identical strains (in mastitis milk and environment) were found in different environmental localizations, its transmission appears to be farm specific. Thus, to establish a farm-specific mastitis control strategy, the main environmental sources of Streptococcus uberis must be analyzed for matching strains. A molecular method such as pulsed-field gel electrophoresis is an important tool that can be used to obtain the necessary information.

Pneumocystis species in Brown Leghorn laying hens--a hint for an extra-mammalian reservoir.

The fungus Pneumocystis spp. causes Pneumocystis pneumonia in immunocompromised mammals including humans, whereas healthy individuals are often colonized and can transmit it to others. There is little evidence that Pneumocystis spp. is also present outside mammalian species. We describe the first detection of Pneumocystis DNA from the lungs and air sacs of laying hens from deep litter and floor husbandry systems. The DNA from chickens' lungs and air sacs was amplified with a Pneumocystis-specific mtLSU rRNA gene nested PCR and sequenced. Pneumocystis DNA was detected in 20 of 111 (18.0%) hens. The DNA sequences showed specific differences to all known Pneumocystis mtLSU sequences. In induced sputum samples of 2 of 7 farm workers at this poultry farm, human Pneumocystis jirovecii strains without these mutations were detected; therefore, a transmission between chickens and farm workers appears implausible.

[Diagnostics and exclusion of hereditary angioedema : a standarized approach for the practice]. / Diagnostik und Ausschluss des hereditären Angioödems : Ein standardisierter Ansatz für die Praxis.

The differentiation between mast cell mediator-mediated and bradykinin-mediated forms of angioedema can be difficult. Bradykinin-mediated hereditary angioedema is a rare autosomal dominant hereditary disease which is characterized by recurrent edema attacks of varying magnitude. The edema occurs in the skin and mucous membranes and can be temporarily disfiguring, very painful and life-threatening by attacks in the laryngeal region. Because of the multitude of differential diagnoses, a final diagnosis is only achieved after an average duration of more than 10 years. The anamnestic and laboratory diagnostic algorithm presented here is designed to assist a simpler differentiation of the various forms of angioedema and to reach the correct diagnosis more quickly.

Recurrent mastitis-persistent or new infections?

Recurrent clinical mastitis contributes to around half of all infections having an economic impact in the dairy industry. It leads to milk yield reduction, increased risk of mortality, and culling, and may be caused by new infections or a persistent infection after previous treatment. Disease management is dependent on the infecting species, necessitating accurate identification of the pathogen in the range of persistent and reinfection cases among recurrent infections using culture and molecular biological analysis. Milk samples from diagnosed clinical mastitis cases were collected from three Northern German dairy farms between 2011 and 2015. Totally, 2043 diagnosed mastitis cases were examined at quarter level (1598 (78.2 %) first and 445 (21.8 %) recurrent mastitis cases in lactation). Among the recurrent cases, 145 (32.6 %) cases were confirmed to harbor the same pathogenic species as previous infections. RAPD PCR confirmed the same species strain in 49 (11 %) of the recurrent infections. The contribution of new infections as compared to persistent infections in cases of clinical mastitis is clear from the data. Future studies in recurrent clinical mastitis control should be focused on influencing factors to prevent new infections in addition to therapeutic intervention and bacteriological cure.

Indication of intracellular magnesium deficiency in lactating dairy cows revealed by magnesium loading and renal fractional excretion.

Nine non-pregnant, lactating dairy cows were used to study plasma and urinary magnesium concentrations ([Mg]pl; [Mg]u), and the urinary fractional excretion of magnesium (FE(Mg)) before, during and after an 120 min intravenous magnesium (Mg) administration (2.5 mg/kg body weight). Animals received a total mixed ration, and Mg content of the diet was within recommended range. Basal mean [Mg]pl, [Mg]u and FE(Mg) were 0.89 +/- 0.09 mm, 5.92 +/- 2.99 mm and 8.3 +/- 9.7% respectively. For all parameters, a substantial inter-individual variation was observed. Three cows showed suboptimal [Mg]pl and/or [Mg]u as well as low FE(Mg) values of approximately 2% indicating an insufficient Mg supply to these animals (depressed feed intake, reduced absorption of Mg). The applied Mg challenge induced no significant change of mean [Mg]pl in the cows because part of the excess Mg was excreted in the urine. But in five out of nine cows, a decrease of the FE(Mg), during and after an intravenous Mg load was observed showing that part of the infused Mg is used to replenish intracellular Mg pools. Thus, the existence of an intracellular Mg deficiency in these cows was unmasked by performing the Mg loading test only. Because a reduced free intracellular [Mg] impairs cell and tissue functions, the results highlight the importance of an accurate definition of the intracellular Mg status. The Mg loading test is a suitable procedure, however, for practical purposes less expensive and time consuming methods must be developed.

Adverse events among people on delamanid for rifampicin-resistant tuberculosis in a high HIV prevalence setting.

SETTING: Patients with rifampicin-resistant tuberculosis (RR-TB) in the township of Khayelitsha, South Africa, were offered delamanid (DLM) within a decentralised RR-TB treatment programme.OBJECTIVE: To describe adverse events (AEs) among HIV-positive and negative people receiving DLM for RR-TB in a programmatic setting.DESIGN: Patients were followed up monthly for blood, electrocardiography and clinical monitoring and AEs were assessed for severity grade, seriousness and relationship to DLM.RESULTS: Fifty-eight patients (55% male; median age 35 years, interquartile range [IQR] 28-42) started DLM; 46 (79%) were HIV-positive, median CD4 count 173 cells/mm³ (IQR 70-294). Fifty (86%) patients experienced ≥1 new or worsening AE after starting DLM, most commonly vomiting, QTcB >450 ms and/or myalgia. Serious and/or severe AEs were experienced by 22 (38%) patients; three HIV-positive patients died (not related to DLM). HIV status was not significantly associated with number (P = 0.089) or severity/seriousness (P = 0.11) of AEs during exposure to DLM. Two (3%) patients had DLM withdrawn due to AEs.CONCLUSION: AEs during RR-TB treatment, both before and during DLM exposure, were common, with relatively few serious/severe AEs considered related to DLM and no significant association with HIV status. Clinical and electrocardiography monitoring should be prioritised in the first two months after starting DLM.

'I didn't know so many people cared about me': support for patients who interrupt drug-resistant TB treatment.

SETTING: Early interventions for patients who interrupt their treatment for drug-resistant tuberculosis (DR-TB) are rarely reported and assessed. A novel, patient-centred intervention for patients at risk of loss to follow-up (LTFU) from DR-TB treatment was implemented in Khayelitsha, South Africa, in September 2013. OBJECTIVE: To explore the experiences and perceptions of patients, key support persons, health care workers (HCWs) and programme managers of a patient-centred model. DESIGN: This was a qualitative study consisting of 18 in-depth interviews with patients, key support persons, HCWs, key informants and one focus group discussion with HCWs, between July and September 2017. Data were coded and thematically analysed. RESULTS: The model was well perceived and viewed positively by patients, care providers and programme managers. 'Normalisation' and tolerance of occasional treatment interruptions, tracing, tailored management plans and peer support were perceived to be beneficial for retaining patients in care. Although the model was resource-demanding, health workers were convinced that it 'needs to be sustained,' and proposed solutions for its standardisation. CONCLUSION: An intervention based on early tracing of patients who interrupt treatment, peer-delivered counselling and individualised management plans by a multidisciplinary team was considered a beneficial and acceptable model to support patients at risk of LTFU from DR-TB treatment.

Indices of heart rate variability as potential early markers of metabolic stress and compromised regulatory capacity in dried-off high-yielding dairy cows.

High performing dairy cows experience distinct metabolic stress during periods of negative energy balance. Subclinical disorders of the cow's energy metabolism facilitate failure of adaptational responses resulting in health problems and reduced performance. The autonomic nervous system (ANS) with its sympathetic and parasympathetic branches plays a predominant role in adaption to inadequate energy and/or fuel availability and mediation of the stress response. Therefore, we hypothesize that indices of heart rate variability (HRV) that reflect ANS activity and sympatho-vagal balance could be early markers of metabolic stress, and possibly useful to predict cows with compromised regulatory capacity. In this study we analysed the autonomic regulation and stress level of 10 pregnant dried-off German Holstein cows before, during and after a 10-h fasting period by using a wide range of HRV parameters. In addition heat production (HP), energy balance, feed intake, rumen fermentative activity, physical activity, non-esterified fatty acids, ß-hydroxybutyric acid, cortisol and total ghrelin plasma concentrations, and body temperature (BT) were measured. In all cows fasting induced immediate regulatory adjustments including increased lipolysis (84%) and total ghrelin levels (179%), reduction of HP (-16%), standing time (-38%) and heart rate (-15%). However, by analysing frequency domain parameters of HRV (high-frequency (HF) and low-frequency (LF) components, ratio LF/HF) cows could be retrospectively assigned to groups reacting to food removal with increased or decreased activity of the parasympathetic branch of the ANS. Regression analysis reveals that under control conditions (feeding ad libitum) group differences were best predicted by the nonlinear domain HRV component Maxline (L MAX, R 2=0.76, threshold; TS=258). Compared with cows having L MAX values above TS (>L MAX: 348±17), those with L MAX values below TS (L MAX cows (18.5±0.4 and 47.3 kg/day). From the present study, it seems conceivable that L MAX can be used as a predictive marker to discover alterations in central autonomic regulation that might precede metabolic disturbances.

Missed opportunities for earlier diagnosis of rifampicin-resistant tuberculosis despite access to Xpert® MTB/RIF.

OBJECTIVE: To assess the proportion of rifampicin-resistant tuberculosis (RR-TB) patients with potential earlier RR-TB diagnoses in Khayelitsha, South Africa. DESIGN: We conducted a retrospective analysis among RR-TB patients diagnosed from 2012 to 2014. Patients were considered to have missed opportunities for earlier diagnosis if 1) they were incorrectly screened according to the Western Cape diagnostic algorithm; 2) the first specimen was not tested using Xpert® MTB/RIF; 3) no specimen was ever tested; or 4) the initial Xpert test showed a negative result, but no subsequent specimen was sent for follow-up testing in human immunodeficiency virus-positive patients. RESULTS: Among 543 patients, 386 (71%) were diagnosed with Xpert and 112 (21%) had had at least one presentation at a health care facility within the 6 months before the presentation at which RR-TB was diagnosed. Overall, 95/543 (18%) patients were screened incorrectly at some point: 48 at diagnostic presentation only, 38 at previous presentation only, and 9 at both previous and diagnostic presentations. CONCLUSIONS: These data show that a significant proportion of RR-TB patients might have been diagnosed earlier, and suggest that case detection could be improved if diagnostic algorithms were followed more closely. Further training and monitoring is required to ensure the greatest benefit from universal Xpert implementation.

Subcellular RNA compartmentalization.

The phenomenon of mRNA sorting to defined subcellular domains is observed in diverse organisms such as yeast and man. It is now becoming increasingly clear that specific transport of mRNAs to extrasomal locations in nerve cells of the central and peripheral nervous system may play an important role in nerve cell development and synaptic plasticity. Although the majority of mRNAs that are expressed in a given neuron are confined to the cell somata, some transcript species are specifically delivered to dendrites and/or, albeit less frequently, to the axonal domain. The physiological role and the molecular mechanisms of mRNA compartmentalization is now being investigated extensively. Even though most of the fundamental aspects await to be fully characterized, a few interesting data are emerging. In particular, there are a number of different subcellular distribution patterns of different RNA species in a given neuronal cell type and RNA compartmentalization may differ depending on the electrical activity of nerve cells. Furthermore, RNA transport is different in neurons of different developmental stages. Considerable evidence is now accumulating that mRNA sorting, at least to dendrites and the initial axonal segment, enables local synthesis of key proteins that are detrimental for synaptic function, nerve cell development and the establishment and maintenance of nerve cell polarity. The molecular determinants specifying mRNA compartmentalization to defined microdomains of nerve cells are just beginning to be unravelled. Targeting appears to be determined by sequence elements residing in the mRNA molecule to which proteins bind in a manner to direct these transcripts along cytoskeletal components to their site of function where they may be anchored to await transcriptional activation upon demand.

[Neck dissection for stage N0 oral cavity carcinoma]. / Evidement cervical dans les carcinomes de la cavité orale classes N0.

OBJECTIVES: The management of N0 neck remains controversial. The purpose of this study was to evaluate the efficacy of selective neck dissection (SND) in managing N0 neck of oral cavity carcinomas. MATERIAL AND METHODS: A retrospective chart review of 77 previously untreated patients with squamous cell carcinomas of the oral cavity with N0 neck from 1988 to 2001 was performed. Cervical treatments were "wait and see" policy in 7 cases, neck dissection in 56 cases, radiotherapy alone in 14 cases. 77 neck dissections were performed in which 62 were selective and 15 were radical modified. RESULTS: On pathologic examination, the average number of lymph nodes was 10.7 per neck. Occult disease (cN0pN+) was detected in 32.5%, and occult extracapsular spread (cN0pN+R+) was detected in 7.8%. The median follow-up was 43 months. The overall neck recurrence rate in patients with controlled primary disease was 2.4%. Recurrent disease developed in 2.9% of the cNOpN0 neck. Regional control rate of the dissected neck was 94%. No cervical recurrence occurred in 11 patients treated with SND alone. There was no survival or recurrence rate difference in T1T2pN0 patients with or without post-operative radiotherapy. Post-operative radiotherapy could be avoided in 27% of the dissected neck. One, 3 and 5 years overall survival rate were 89.3%, 77.7% and 63.2%. CONCLUSIONS: SND is an effective procedure for staging and treating the clinically negative neck of oral cavity cancer.

Surgical implantation and functional assessment of an invasive telemetric system to measure autonomic responses in domestic pigs.

The first aim of this study was to establish a surgical procedure to implant a new telemetric device for the continuous recording of electrocardiogram (ECG) and blood pressure (BP) in freely moving pigs. A second aim was the functional assessment of cardiovascular parameters, including heart rate variability (HRV) and blood pressure variability (BPV), so that these data could be used as the basis for the objective evaluation of autonomic activity and balance in different behavioural contexts. Eleven domestic pigs (German Landrace) underwent surgery for the placement of a telemetric device. At day 15 after surgery, 512 consecutive inter-beat intervals and pressure waves were analysed using different detection methods (automatic and manually corrected) while the animals were resting or feeding, respectively. HRV and BPV were calculated. Incomplete datasets were found in four pigs due to missing ECG or BP signals. Technical and surgical issues concerning catheterisation and detachment of the negative ECG lead were continuously improved. In the remaining pigs, excellent signal quality (manually corrected data of 1%) was obtained during resting and acceptable signal quality (<10%) was obtained during feeding. Automatic triggering was sufficiently reliable to eliminate errors in BP recordings during active behaviour, but this was not the case for ECG recordings. Sympathetic arousal with accompanying vagal withdrawal during feeding was documented. The established surgical implantation and functional assessment of the telemetric system with the reliable registration of cardiovascular parameters in freely moving pigs could serve as a basis for future studies of autonomic regulation in context of stress and animal welfare.

The experience of bedaquiline implementation at a decentralised clinic in South Africa.

Multidrug-resistant tuberculosis (MDR-TB) is a serious public health problem, but the new drugs bedaquiline (BDQ) and delamanid offer hope to improve outcomes and minimise toxicity. In Khayelitsha, South Africa, patients are routinely started on BDQ in the out-patient setting. This report from the field describes BDQ use in the out-patient setting at the Nolungile Clinic. The clinic staff overall report a positive experience using the drug. Challenges have been based largely on the logistics of drug supply and delivery. BDQ can be started successfully in the out-patient setting, and can be a positive experience for both patients and providers. La tuberculose multirésistante (TB-MDR) est un problème de santé publique grave, mais les nouveaux médicaments que sont la bédaquiline (BDQ) et le délamanide apportent un espoir d'améliorer les résultats tout en réduisant la toxicité. A Khayelitsha, Afrique du Sud, les patients démarrent leur traitement par BDQ en consultation externe en routine. Ce rapport du terrain décrit l'utilisation de la BDQ à la consultation externe du dispensaire Nolungile. Dans l'ensemble, le personnel du centre de santé exprime une expérience positive du médicament. Les défis ont surtout été liés à la logistique de l'approvisionnement et de la distribution du médicament. La BDQ peut être mise en route avec succès dans le cadre d'une consultation externe et peut constituer une expérience positive pour les patients et les prestataires de soins. La tuberculosis multirresistente (TB-MDR) representa un grave problema de salud pública, pero la utilización de nuevos medicamentos como la bedaquilina (BDQ) y el delamanid ofrece perspectivas de mejores desenlaces terapéuticos y disminución de la toxicidad asociada. En Khayelitsha, Suráfrica, se inicia de manera sistemática el tratamiento ambulatorio con BDQ. En el presente informe del terreno, se describe la utilización de BDQ en tratamiento antituberculoso ambulatorio en el centro de atención Nolungile. En general, los miembros del personal del centro refirieron una experiencia positiva con la administración del medicamento. Las dificultades surgieron en gran parte con respecto a aspectos logísticos del suministro y la administración del medicamento. Es posible iniciar un tratamiento eficaz con BDQ en condiciones ambulatorias, y represente una experiencia positiva para los pacientes y los profesionales de salud.

[Vestibular neurotomy versus chemical labyrinthectomy for disabling Menière disease]. / Neurotomie vestibulaire vs. labyrinthectomie chimique dans la maladie de Menière invalidante.

OBJECTIVE: To evaluate the efficiency on the vertigos and the impact on the audition of the vestibular neurotomy (VN) and the chemical labyrinthectomy (CL) in patients with severe Menière's disease, in order to determine the precise place for each technique in treatment algorithm. METHOD: Retrospective study of 71 VN (performed between 1986 and 2003) and 35 CL (performed between 1997 and 2003). These two treatments both aim at obtaining a vestibular deafferentation in order to free definitely the patient of vertigo manifestations. Vestibular results have been assessed by caloric tests performed before and 6 months after treatment. Subjective success was evaluated by searching for recurrent attacks of vertigo and by the AAO-HNS (American Academy of Otolaryngology-Head and Neck Society) scale of subjective evaluation of vertigos (follow-up of 6.4 years after VN and 2.4 years after CL). Pure tone audiometry before treatment and then 6 months later was performed. Complications of two types of treatment were recorded and evaluated. RESULTS: In 90% of the cases after VN and 86% of the cases after CL, caloric tests indicated a strong vestibular hyporeflexy (hypovalence > 90%). Attacks of vertigo reoccurred in 5.6% of the cases when the hyporeflexy was strong and 85.7% of the cases when it was weak. The quality of the vestibular results on vertigo depends on the degree of hypovalence after treatment. An improvement of the AAO-HNS scale have been obtained in 93% of the cases in the NV group and in 81% of the cases in the LC group. Attacks of vertigo were recurrent in 7% of the patients operated on by VN and 11.4% of the patients treated by CL. Mean pure tone auditory thresholds changed from 50.24 dB HL to 55.64 dB HL (p=0.003) in the VN group and from 69.11 dB HL to 74.51 dB HL (p=0.41) in the CL group. Comparison of the variations of the mean pure tone auditory thresholds before treatment and 6 months after the end of the treatment doesn't show any significant difference between the 2 groups (p > 0.05). Impairment of the audition superior to 20 dB HL was observed in 8.5% of the patients of each group. The auditive results are similar in the 2 groups. CONCLUSION: These two methods of treatment can not be strictly compared due to several bias in this study. Indeed more patients were treated by VN with a longer follow-up and only the patients with a class C or D audition according to the criteria of the AAO-HNS could be treated by CL. The VN provides a better control of the vertigos than the CL which is an efficient method of treatment in invalidating Meniere's disease. In all the cases, the quality of the results on vertigos depends on the degree of hypovalence after treatment. The auditive results are similar. Since the results of the two treatments are similar, the simplicity of CL encourages us to broaden the indications and to modify the place of the VN in the therapeutic algorithm of Menière's disease.

Patient support interventions to improve adherence to drug-resistant tuberculosis treatment: A counselling toolkit.

In response to the growing burden of drug-resistant tuberculosis (DR-TB) in South Africa (SA), Médecins Sans Frontières (MSF), with local government health departments, piloted a decentralised model of DR-TB care in Khayelitsha, Western Cape Province, in 2007. The model takes a patient-centred approach to DR-TB treatment that is integrated into existing TB and HIV primary care programmes. One essential component of the model is individual and family counselling to support adherence to and completion of treatment. The structured and standardised adherence support sessions have been compiled into a DR-TB counselling toolkit. This is a comprehensive guide that focuses on DR-TB treatment literacy, adherence strategies to encourage retention in care, and provision of support throughout the patient's long treatment journey. Along with other strategies to promote completion of treatment, implementation of a strong patient support component of DR-TB treatment is considered essential to reduce rates of loss from treatment among DR-TB patients. We describe our experience from the implementation of this counselling model in a high DR-TB burden setting in Khayelitsha, Cape Town, SA.

Messenger RNA on the move: implications for cell polarity.

RNA sorting is an evolutionarily conserved mechanism for establishing asymmetries within a given cell concerning the macromolecular equipment of defined domains. mRNAs as well as non-coding transcripts are delivered to specific subcellular compartments in diverse organisms including developmental systems of Drosophila, Xenopus, ascidiens, zebrafish and echinoderms and in differentiated cells from yeast to mammals. The composition of the RNA localization machinery is complex. Both sequence- or structural motifs within RNA molecules to be transported (cis-acting elements) and various proteins (trans-acting factors) contribute to the localization procedure. Most often these macromolecular ribonucleoprotein complexes exhibit a granular appearance, and granule localization depends on intact microfilaments or microtubules. When delivered to their ultimate destinations mRNAs are anchored to await translational activation at the appropriate timepoint. Beyond doubt, RNA localization plays a pivotal role in embryonic development, where mRNA mislocations cause severe body pattern defects. In terminally differentiated vertebrate cells RNA transport and local on-site translation presumably have an impact on various cellular functions such as cell motility, myelinization of nerve cell axons and nerve cell communications in the central and peripheral nervous system.

Sequence analysis of the promoter region of the rat vasopressin gene.

The vasopressin gene is highly transcribed in magnocellular neurons of the supraoptic (SON) and paraventricular nucleus (PVN) in the rat hypothalamus. In order to identify cis-acting elements involved in the expression of the vasopressin gene, approximately 1 kb upstream of the transcription start site has been sequenced. Several putative regulatory elements have been detected, including a glucocorticoid response element (CRE), a cAMP response element (CRE), and four AP2 binding sites. In gel shift assays performed with a labelled DNA fragment corresponding to nucleotide residues -214 to -36 and nuclear proteins extracted from SON-derived tissue enriched in magnocellular neurons, three specific protein-DNA complexes have been detected. Complex formation is effectively competed by addition of an excess of unlabelled fragment.

Expression of the vasopressin and oxytocin genes in rats occurs in mutually exclusive sets of hypothalamic neurons.

The genes for the hypothalamic hormones vasopressin and oxytocin are located in close proximity to each other within the rat genome. They are separated by only approx. 11 kbp of DNA sequence and oriented in such a way that their transcription occurs on opposite DNA strands. Although the two genes are structurally very similar including common potential regulatory elements in their putative promotor regions, they are expressed in discrete populations of magnocellular neurons of the hypothalamus. In rats placed under osmotic stress, the vasopressin gene is upregulated; concomitantly transcription of the oxytocin gene is also stimulated. To address the question of whether this coordinated rise in oxytocin-encoding mRNA is the result of switching on oxytocin gene transcription in vasopressinergic neurons, in situ hybridization with double labelled cRNA probes was carried out. Biotinylated and [alpha-35S]CTP labelled antisense cRNA probes specific for either vasopressin or oxytocin mRNA were constructed and hybridized to hypothalamic sections from salt-loaded rats. The results demonstrate that upregulation of oxytocin gene transcription is restricted solely to oxytocinergic cells; no oxytocin gene transcripts can be detected in vasopressinergic neurons.

Effect of hypoosmolality on the abundance, poly(A) tail length and axonal targeting of arginine vasopressin and oxytocin mRNAs in rat hypothalamic magnocellular neurons.

Arginine vasopressin (AVP) and oxytocin (OT) mRNAs are targeted to the axonal compartment of rat hypothalamic magnocellular neurons. Salt-loading results in a considerable rise in hypothalamic and axonal AVP mRNA but only a moderate increase for axonal OT mRNA. Here we report that hypoosmolality gives rise to a rapid decrease of axonal AVP encoding transcripts to undetectable levels after 2 weeks. The levels of OT mRNA in the axonal compartment did not change significantly. In the hypothalamus the mRNA for AVP also decreased. The size of the poly(A) tract of AVP encoding transcripts appeared to be strictly correlated with plasma osmolality. In contrast, the amount and size of OT encoding mRNAs were only moderately or not influenced by hypoosmolar stimuli.