ErbB receptors and PKC regulate PC12 neuronal-like differentiation and sodium current elicitation

Excitability, neurite outgrowth and their specification are very important features in the establishment of neuronal differentiation. We have studied a conditioned medium (CM) from sciatic nerve which is able to induce a neuronal-like differentiation of PC12 cells. Previously, we have demonstrated that supplementing this CM with a generic inhibitor (k252a), which mainly inhibits tropomyosin-related kinase receptors (Trk receptors) and protein kinase C (PKC), caused neurite elongation, sodium current induction and axon development. In the present work, we are showing that the enhancement of neurite length and induction of sodium currents induced by CM+k252a were prevented by ErbB receptor inhibition. Additionally, we demonstrated that specific inhibition of PKC produced a similar effect to that exerted by k252a in CM-treated cells, specifically by increasing the percentage of differentiated cells with long neurites and inducing sodium currents. Moreover, CM changed the mRNA levels for ErbB2 and ErbB3 increasing them 6- and 36-folds respectively compared to their control. The inclusion of k252a with CM changed the ErbB1, ErbB2 and ErbB3 mRNA proportions increasing those eight-, seven- and fivefolds respectively. From this point, it is clear that appropriate ErbB receptor levels and PKC inhibition are necessary to enhance the effect of the CM in inducing the neuronal-like differentiation of PC12 cells. In summary, we demonstrated the involvement of ErbB receptors in the regulation of neurite elongation and sodium current induction in PC12 cells and propose that these processes could be initiated by ErbB receptors followed by a fine regulation of PKC signaling. These findings might implicate a novel interplay between ErbB receptors and PKC in the regulation of these molecular mechanisms.

The Neuroid: A novel and simplified neuron-model

In this paper we introduce a novel computational neuron-model, the Neuroid, which is based on three basic operations that are carried out by nerve cells to process the incoming information, such as comparison, and frequency pulse modulation-demodulation. The model was implemented using LabVIEW 10.0, in order to assign to each of these operations, an execution block (Virtual Instrument). The results of its implementation showed a very similar behavior to that exhibited by real neurons. Furthermore, due to its simplicity and low computational requirements, it is expected that the Neuroid can be used to create several software models of biological neural systems, either for research or teaching purposes.

Bactridine's effects on DUM cricket neurons under voltage clamp conditions

We describe the effects of six bactridines (150 nM) on cricket dorsal unpaired median (DUM) neurons. The addition of bactridine 2 to DUM neurons induced a large current component with a reversal potential more negative than -30 mV, most evident at the end of the pulses. This current was completely suppressed when 1 μM amiloride was applied before adding the bactridines. Since the amiloride sensitive current is able to distort the aim of our study, i.e. the effect of bactridines on sodium channels, all experiments were done in the presence of 1 μM amiloride. Most bactridines induced voltage shifts of V(1/2) of the Boltzmann inactivation voltage dependency curves in the hyperpolarizing direction. Bactridines 1, 4 and 6 reduced Na current peak by 65, 80 and 24% of the control, respectively. The sodium conductance blockage by bactridines was voltage independent at potentials >20 mV. Bactridines effect on cricket DUM neurons does not correspond to neither α- nor β-toxins. Most bactridines shifted the inactivation curves in the hyperpolarizing direction without any effects on the activation m(∞)-like curves. Also bactridines differ from other NaScpTx in that they increased an amiloride-sensitive conductance in DUM neurons. Our result suggest that the α/β classification of sodium scorpion toxins is not all encompassing. The present work shows that bactridines target more than one site: insect voltage dependent Na channels and an amiloride-sensitive ionic pathway which is under study.

Quantitative assessment of the efficacy of spiral-wound membrane cleaning procedures to remove biofilms

Cleaning of high pressure RO/NF membranes is an important operational tool to control biofouling. Quantitative information on the efficacy of cleaning agents and protocols to remove biomass is scarce. Therefore, a laboratory cleaning test to assess the efficiency of cleaning procedures to remove attached biomass was developed. The major components of the test are (i) production of uniform biofilm samples, (ii) the quantification of the biomass concentrations with robust parameters and (iii) a simple test procedure with optimal exposure of the biofilm samples to the chemicals. The results showed that PVC-P is a suitable substratum for the production of uniform biofilm samples. ATP and carbohydrates (CH) as major components of the biofilm matrix for nucleotides (living bacterial cells) and extracellular polymeric substances EPS, respectively, were selected as robust biomass parameters. The removal of ATP and CH with the NaOH/Sodium Dodecyl Sulfate (SDS) mixture, selected as a standard treatment at pH 12.0, was reproducible. The resistance of the EPS matrix against chemical cleaning was demonstrated by a low CH removal (32.8 ± 6.0%) compared to the ATP removal (70.5 ± 15.1%). The inverse relationship of biomass removal with the CH to ATP ratio (μg/ng) of the biofilms demonstrated the influence of the biomass characteristics on cleaning. None of the 27 chemicals tested (analytical-grade and commercial brands) in single step or in double-step treatments were significantly more effective than NaOH/SDS. Oxidizing agents NaOCl and H(2)O(2), the latter in combination with SDS, both tested as common agents in biofilm control, showed a significantly higher efficiency (70%) to remove biofilms. In the test, simultaneously, the efficiency of agents to remove precipitated minerals such as Fe can be assessed. Validation tests with Cleaning in Place (CIP) in 8 and 2.5-inch RO membrane pilot plant experiments showed similar ranking of the cleaning efficiency of cleaning protocols as determined in the laboratory tests. Further studies with the laboratory test are required to study the effect of cleaning conditions such as duration, temperature, shear forces as well as chemical conditions (concentrations, alternative agents or mixtures and sequence of application) on the efficiency to remove attached biomass.

Preliminary results in the redox balance in healthy cats: influence of age and gender

Oxidative stress (OS) impairs organic function and is considered causally related to cellular senescence and death. This study aims to evaluate if the redox balance varies in relation to age and gender in healthy cats. To quantify the oxidative status of this species we determined the oxidative damage as serum reactive oxygen metabolites (ROM) and the total serum antioxidant capacity (SAC). In addition, we used the ratio of ROM to SAC as a measure of the oxidative balance, with higher values meaning higher oxidative stress (oxidative stress index). Our results suggest that the male population is at oxidative risk when compared with females, especially between the age of 2 and 7 years. Nutritional strategies in this population looking for additional antioxidant support would probably avoid the oxidative stress status that predisposes to chronic processes in senior male cats. Further clinical trials in this field are recommended.

Role of matrix metalloproteinases 2 and 9 in ex vivo Trypanosoma cruzi infection of human placental chorionic villi

BACKGROUND

Chagas' disease is caused by the haemophlagelated protozoan Trypanosoma cruzi (T. cruzi). During congenital transmission the parasite breaks down the placental barrier. In the present study we analyzed the participation of matrix metalloproteases (MMPs) in the extracellular matrix (ECM) remodeling during T. cruzi ex vivo infection of human placental chorionic villi explants.

METHODS

Chorionic villi from healthy woman placentas were incubated in the presence or absence of 10⁵ or 10⁶ T. cruzi trypomastigotes (Y strain) with or without the MMPs inhibitor doxycycline. Effective infection was tested measuring parasite DNA by real time PCR (qPCR). MMP-2 and MMP-9 expression were determined by western blotting and immunohistochemistry and their activities were measured by zymography. The effect of MMPs on ECM structure was analyzed histochemically.

RESULTS

T. cruzi induces the expression and activity of MMP-2 and MMP-9 in chorionic villi. Inhibition of the MMPs prevents the tissue damage induced by T. cruzi and partially decreases the ex vivo infection of the chorionic villi.

CONCLUSION

MMPs are partially responsible for the ECM changes observed in human chorionic villi during T. cruzi infection and participate in tissue invasion. On the other hand, MMPs may be part of a local placental antiparasitic mechanism.

BOTULISMO TIPO C EM UM REBANHO DE NOVILHAS LEITEIRAS NO NOROESTE DA ESPANHA

Intoxicações por toxina botulínica dos tipos B e C tem sido relatadas em bovinos como consequência do consumo de alimento contaminado com carcaças putrefatas de animais ou cama de frango, mas silagem de pasto embalada em fardos com cobertura plástica, também pode ser fonte de intoxicações botulínicas. No presente trabalho, realizado em um rebanho de novilhas leiteiras no Noroeste da Espanha, a assistência veterinária foi procurada devido a que 21 novilhas apresentavam decúbito com suas cabeças flexionadas lateralmente, letárgicas, relutantes a movimentar-se e com os membros contraídos. Em poucos animais foi possível observar salivação excessiva e dificuldade para retrair a língua. No exame físico não se encontrou motivo para o decúbito e as novilhas foram tratadas para aliviar os sinais clínicos. Uma semana depois do surto, 8 novilhas morreram e 5 novilhas foram eutanasiadas por motivos éticos, tendo sobrevivido apenas 8 novilhas. As novilhas estavam alimentadas com ração misturada a vontade constituída por silagem fresca, feno e ração comercial. Foi verificado que a cobertura plástica da silagem estava danificada aos lados, estragada e com mofo. Em análise posterior foi encontrada toxina tipo C de Clostridium botulinum a partir de amostras de silagem mofada. Os resultados junto com a história clínica e os sinais clínicos levaram ao diagnóstico de botulismo tipo C.

[Cystitis and ketamine associated bladder dysfunction]

OBJECTIVES

To analyze the prevalence of lower urinary tract symptoms (LUTS) in recreational ketamine users and evaluate its relationship with the consumption pattern.

MATERIAL AND METHODS

Evaluation of 13 ketamine users. The presence of LUTS, gross hematuria and lumbar spine pain was analyzed. The ketamine usage pattern was recorded: initiation, administration route, dose in the last month and frequency of usage.

RESULTS

Six patients (46%) reported LUTS, with daily mean micturations every 42 minutes and nighttime of 3 episodes, with dysuria (100%), urgency (100%), incontinence (20%), decreased flow (80%), hypogastric or perineal pain (80%), gross hematuria (80%) and bilateral lumbar spine pain (40%). Symptomatic patients described a mean intake of inhaled ketamine of 3g/day (SD 2), 80% with a daily frequency and the asymptomatic ones of 1.03 g/day (SD 0.92) limited to weekends. The mean consumption time to the appearance of the symptoms was 31 months (SD 16.29). Intensity of the symptoms was related with the ketamine dose and improved on increasing water intake.

CONCLUSIONS

There seems to be a relationship between the picture with the dose and frequency of consumption, there being factors that reinforce the hypothesis that this action of the drug is due to the harmful effect on the urothelium. The process to identify it on time should be known, since the only known effective measure is to stop the consumption in the initial phases.

Serum metabolite concentrations and enzyme activities in finishing bull calves fed different types of high-grain diets

Abstract. Between the ages of 23 and 35 weeks, various serum metabolites and enzymes were monitored in three 10-animal groups of double-muscled Belgian Blue bull calves maintained in a feedlot in Galicia (NW Spain) on high-grain finishing diets that mainly differed in whether the grain used was predominantly maize (group M), predominantly barley (group B), or a mixture of maize and barley in approximately equal proportions (group MB). The parameters determined were glucose, non-esterified fatty acids (NEFA), total serum protein concentration (TSP), albumin, serum urea nitrogen (SUN), creatinine, aspartate aminotransferase (AST), and gamma-glutamyltransferase (GGT). Throughout the study period, all these parameters remained within the physiological ranges for beef under intensive conditions, and no animal ever showed clinical symptoms of ruminal alterations; indicating that none of these highgrain diets were detrimental to animal health. Although average serum NEFA, creatinine, albumin, AST and GGT levels all differed among groups, only AST can be considered as possible age-independent marker of grain-type-related metabolic alterations, since the other parameters all showed significant time × group interaction. In terms of this parameter, animals fed a MB diet behaved similarly to those fed a B diet. The absence of between-group differences in blood glucose level may reflect a genetic characteristic of this double-muscled breed. Our results, in conjunction with the best productive results obtained in animals fed de B-diet, aim us to suggest that the risk of an acidogenic diet would depend strongly on the nutritional management (in terms of crude protein (CP) and quality of straw in the ration) and not only the type of grain.

Restricted wheel access following a light cycle inversion slows re-entrainment without internal desynchrony as measured in Per2Luc mice

Circadian rhythms are physiological and behavioral oscillations that have period lengths of approximately 24 h. In mammals, circadian rhythms are driven by a master pacemaker in the hypothalamic suprachiasmatic nucleus (SCN). These rhythms can be entrained to light:dark cycles through photic and non-photic cues. Current research suggests that the SCN re-entrains rapidly to new light:dark (LD) cycles with the first photic cues, whereas peripheral tissues re-entrain more slowly, leading to a transient state of internal disorder while the organism adjusts to the new timing of photic input. To assess internal temporal order during the readjustment we used dim light to slow the rate of re-entrainment following a 12-h inversion of the LD cycle. We also used a wheel-restriction paradigm, which can block behavioral evidence of re-entrainment. Per2(Luc) mice were entrained to a 12:12 dim LD cycle with wheel access ad libitum. Following a 12-h shift in the LD cycle, some animals were subjected to wheel restriction; wheels were locked during the new dark period and available during the new light period. Other mice had wheels available ad lib throughout the experiment. Behavioral actograms of general locomotor activity as measured with motion sensors indicated that mice with ad lib access to wheels were able to re-entrain at a rate significantly faster than mice with restricted wheel access. Up to 2 weeks following the LD inversion many wheel-restricted animals were still active predominantly in the new light period. Phase of the PER2::LUC bioluminescence rhythms in SCN and four peripheral tissues (lung, esophagus, thymus, and spleen), measured ex vivo on days 2, 9, and 16 following the inversion, indicated that within each condition the SCN and peripheral tissues shifted at the same rate, whereas the rate of re-entrainment for the tissues differed between conditions. Ex vivo data showed that the PER2::LUC peaks in SCN and peripheral tissues were closely linked to time of activity onset in both groups. Thus, this wheel restriction protocol is capable of reducing and in some cases apparently hindering photic re-entrainment of the circadian system, verifying this protocol as a mechanism for study of photic/non-photic entrainment interactions. Our results suggest that LD inversion under dim light and a wheel-restriction protocol does not induce internal desynchrony, indicating that slowing the rate of shift by limiting both entrainment inputs may induce less "jet lag".

Adherence and satisfaction survey in outpatients on treatment with antipsychotics

Introduction

One of the problems of many studies and clinical trials is that don’t reflect the patient's opinion about the medication that they receive and their satisfaction.

Objetive and aims

The aim of this study was to assess the degree of outpatients satisfaction with antipsychotic treatment in four outpatients clinics in Mallorca. The adherence rates was estimated from information provided by the patients and their psychiatrists.

Methods

A cross.-sectional and descriptive study was conducted during one month, from May to June 2010, by administering several questionnaires to outpatients with psychotic disorders. It was designed a case report data which recorded the following variables: age, gender, diagnosis (schizophreniform, schizophrenia, schizoaffective disorder, delusional, psychotic disorder not otherwise specified), time since diagnosis, substance use, number of antipsychotic drugs, type of antipsychotic (oral and / or im), number of doses per day and number of tablets, via of administration (buttocks or deltoid). The psychometric instruments used were: the Morisky-Green test, Haynes-Sacket test, the MSQ (Medication Satisfaction Questionnaire) and CGI (Clinical Global Impression).

Results

The sample was of 92 patients with a mean age of 42.1 years (SD 12.2): 57.6% male and the most frequent diagnosis was schizophrenia in 65.2%. The duration of treatment from diagnosis was more than 5 years in 66.3%.

Conclusions

The patients on maintenance monotherapy with RLAI showed better adherence rates and more insight, evaluated by their psychiatrits.

78% of patients receiving antipsychotic medication injections were satisfied with the treatment.

Patients with RLAI administrating in deltoid were satisfied in 65.7%.

The N-methyl-D-aspartate-evoked cytoplasmic calcium increase in adult rat dorsal root ganglion neuronal somata was potentiated by substance P pretreatment in a protein kinase C-dependent manner

The involvement of substance P (SP) in neuronal sensitization through the activation of the neurokinin-1-receptor (NK1r) in postsynaptic dorsal horn neurons has been well established. In contrast, the role of SP and NK1r in primary sensory dorsal root ganglion (DRG) neurons, in particular in the soma, is not well understood. In this study, we evaluated whether SP modulated the NMDA-evoked transient increase in cytoplasmic Ca2+ ([Ca2+]cyt) in the soma of dissociated adult DRG neurons. Cultures were treated with nerve growth factor (NGF), prostaglandin E2 (PGE2) or both NGF+PGE2. Treatment with NGF+PGE2 increased the percentage of N-methyl-D-aspartate (NMDA) responsive neurons. There was no correlation between the percentage of NMDA responsive neurons and the level of expression of the NR1 and NR2B subunits of the NMDA receptor or of the NK1r. Pretreatment with SP did not alter the percentage of NMDA responsive neurons; while it potentiated the NMDA-evoked [Ca2+]cyt transient by increasing its magnitude and by prolonging the period during which small- and some medium-sized neurons remained NMDA responsive. The SP-mediated potentiation was blocked by the SP-antagonist ([D-Pro4, D-Trp7,9]-SP (4-11)) and by the protein kinase C (PKC) blocker bisindolylmaleimide I (BIM); and correlated with the phosphorylation of PKCε. The Nk1r agonist [Sar9, Met(O2)11]-SP (SarMet-SP) also potentiated the NMDA-evoked [Ca2+]cyt transient. Exposure to SP or SarMet-SP produced a rapid increase in the labeling of phosphorylated-PKCε. In none of the conditions we detected phosphorylation of the NR2B subunit at Ser-1303. Phosphorylation of the NR2B subunit at Tyr1472 was enhanced to a similar extent in cells exposed to NMDA, SP or NMDA+SP, and that enhancement was blocked by BIM. Our findings suggest that NGF and PGE2 may contribute to the injury-evoked sensitization of DRG neurons in part by enhancing their NMDA-evoked [Ca2+]cyt transient in all sized DRG neurons; and that SP may further contribute to the DRG sensitization by enhancing and prolonging the NMDA-evoked increase in [Ca2+]cyt in small- and medium-sized DRG neurons.

Effects of d-amphetamine on short- and long-term memory in spontaneously hypertensive, Wistar-Kyoto and Sprague-Dawley rats

Diverse studies indicate that the attention deficit hyperactivity disorder (ADHD) is associated with alterations in encoding processes, including working or short-term memory. Some ADHD dysfunctional domains are reflected in the spontaneously hypertensive rat (SHR). Here SHR-saline group showed significantly poor STM and LTM relative to SD and WKY saline rats. SD and WKY rats treated with d-amphetamine displayed better STM and LTM, compared to SD-vehicle, WKY-vehicle or SHR-d-amphetamine groups.