PAM-2 decreases neuropathic pain in mice and modulates chemokine/cytokine production in human microglial cells

Background: People worldwide suffer from neuropathic pain, and indicated medications are often either not effective or induce tolerance and abuse. Therefore, there is an urgent need to identify additional therapeutic options to treat this form of pain. Nicotinic acetylcholine receptors (nAChRs), particularly a7-nAChRs, have been implicated in pain signaling. Therefore, this study was designed to investigate the extent to which the selective positive allosteric modulator (PAM) of a7 AChRs, PAM-2, modulates neuropathic pain. The working hypothesis, that PAM-2 inhibits inflammatory signaling and neuropathic pain, was tested using animal and cellular models.Methods: The anti-neuropathic pain activity of PAM-2 was assessed in two independent murine models of neuropathic pain. Briefly, neuropathic pain was induced in adult, male CD-1 mice (n=10/condition) via i.p. administration of either streptozotocin (STZ) or oxaliplatin (OXA). After 14 days, when neuropathic pain was present, mice were administrated with PAM-2 (1.0 or 3.0 mg/kg, p.o.) or vehicle. The pain threshold was subsequently determined by the cold plate test before and 15, 30, 45, and 60 min after treatment. In addition, C20 human microglial cells were exposed to interleukin (IL)-1B (20 ng/ml) or vehicle alone, and in combination with nicotine (3 uM), PAM-2 (1-100 uM), or nicotine + PAM-2 for 24 h. After 24 h, cytokine/chemokine levels in the culture media were measured by ELISA.Results: A single dose of PAM-2 (3.0 mg/kg) decreased both STZ- and OXA-induced neuropathic pain in mice. Repeated treatment with an inactive dose (1.0 mg/kg) of PAM-2 showed anti-pain activity in OXA-treated mice after 14, but not 7, days of treatment. Additionally, methyllycaconitine blocked the anti-pain effects elicited by PAM-2, supporting the view that a7 AChRs are instrumental in the anti-pain actions of PAM-2. Cellular experiments revealed that nicotine minimally inhibited IL-1B-induced IL-6 and interferon-gamma-induced chemotactic protein 10 expression in C20 human microglial cells, and that this inhibition was potentiated by PAM-2 (100 uM). However, we cannot rule out the possibility that PAM- 2 was cytotoxic in this cell culture model.Conclusions: These findings indicate that a7 AChRs are involved in neuropathic pain signaling and that a7-PAMs may potentially be used therapeutically. The extent to which these protective effects involve reduced neuroinflammation remains to be determined

EFECTO DEL VOLTAJE SOBRE LA FORMACIÓN DE NANOESTRUCTURAS DE TiO2 VÍA ANODIZADO ELECTROQUÍMICO

En este trabajo se fabricaron arreglos de nanotubos de TiO2 por el método de anodizado electroquímico usando tanto para el ánodo como para el cátodo láminas de Ti y diferentes voltajes deanodización. Para la preparación de las muestras se usó una mezcla de agua y solución de etilenglicol a temperatura ambiente cambiando el tiempo de síntesis durante la reacción. Se realizaron procesos de recocido a todas las muestras en el rango entre 273 y 723 K, sin observarse cambios en las propiedades morfológicas del material. A partir de medidas de difracción de rayos X fueron identificadas las fases rutilo y anatasa en todas las muestras; cuando la temperatura de recocido superó los 723 K, se observó un cambio estructural de la fase anatasa a rutilo. A partir de medidas de SEM se observó que el tamaño del diámetro interno de los nanotubos varió entre 37 nm y 41 nm cuando el voltaje de anodización fue alternante y constante, respectivamente. Se observó que un tamaño de ~6 um de longitud y 29,56 nm de espesor de la barrera del tubo están influenciados por el voltaje de anodización constante de 80 V; sin embargo nanotubos con forma de guadua se evidenciaron cuando se aplicó un voltaje alternantede 80 V y 20 V durante 1 minuto y 5 minutos respectivamente. Sepresenta una correlación entre los parámetros de síntesis y laspropiedades morfológicas.In this work TiO2 nanotubes arrays were obtained by electrochemical anodization method using Ti foil, both anode and cathode, and under different anodization voltages. A mix of water and ethylene glycol as electrolyte was used at environment temperature for several times of reaction. Annealing process to TiO_2 samples were realized at temperature between 273 and 723 K without changes on morphological properties. Rutile and anatase phases were identified by X-ray diffraction measurements in all samples and a change of anatase to rutile phase was observed at biggest annealing temperature (T=723 k). From SEM measurements the inner diameter size for nanotubes were obtained, varying between 37 nm and 41 nm when anodizing voltage was alternant and constant, respectively. Nanotubes with ~6 um of length and 29.56 nm thickness of barrier layer were obtained as influence of the anodizition voltage of 80 V fixed; however nanotubes with bamboo form were observed at alternant voltage of 80 and 20 V during 1 minute and 5 minutes, respectively. A correlation between deposition parameters and morphological properties is presented

Modelo experimental de Chagas en conejos

La enfermedad de Chagas es una antropozoonosis que afecta aproximadamente a 12 millones de personas en América Latina. El objetivo de este trabajo es establecer un modelo experimental de Chagas en conejos.Facultad de Ciencias Veterinaria

Escherichia coli Enteropatógena en Crías de Primate Aotus (Aotidae) con Diarrea en Cautiverio

Diarrhea is the most common sign of gastrointestinal disease in young primates kept in captivity. The study aimed to isolate and identify bacterial species present in young Aotus with diarrhoea. The animals were reared in captivity for experimental purposes. Faecal samples were collected using rectal swabs from 78 monkeys of 1 to 7 months old of A. nancymae (n=65) and A. vociferans (n=13) with diarrhoea, and 29 apparently healthy monkeys of 1 month old of A. nancymae (n=21) and A. vociferans (n=8) in the period 2002 to 2005. In the healthy group was most commonly identified E. coli, followed by Proteus vulgaris, P. mirabilis and Citrobacter freundii. A similar result was obtained in the group with diarrhea, plus Klebsiella oxytoca and Enterobacter aerogenes. Serotypes of enteropathogenic E. coli (EPEC) identified in the group with diarrhea were seven: O158, O142, O86, O125, O126, O55, and O111. The results showed that young alpacas with diarrhea have bacteria corresponding to the normal intestinal flora, and the primary isolated bacterium was E. coli.La diarrea es el signo más frecuente de enfermedad gastrointestinal en crías de primates mantenidas en cautiverio. El estudio tuvo como objetivo aislar e identificar especies bacterianas presentes en crías de Aotus con diarrea que son criadas en cautiverio con fines experimentales. Se tomaron muestras de heces mediante hisopado rectal a 78 ejemplares de 1 a 7 meses de edad de A. nancymae (n=65) y A. vociferans (n=13) con diarrea y a 29 ejemplares de 1 mes de edad, aparentemente sanos de A. nancymae (n=21) y A. vociferans (n=8), durante el periodo de 2002 a 2005. En el grupo control se identificó principalmente E. coli, además de Proteus vulgaris, P. mirabilis y Citrobacter freundii. Resultado similar fue registrado en el grupo con diarrea, además de Klebsiella oxitoca y Enterobacter aerogenes. Los serotipos de E. coli enteropatógena (EPEC) identificados en el grupo con diarrea fueron siete: O158, O142, O86, O125, O126, O55 y O111. Los resultados indican que las crías con diarrea tienen bacterias que corresponden a la flora intestinal normal, siendo E. coli la de mayor frecuencia

Integrating the STOP-BANG Score and Clinical Data to Predict Cardiovascular Events After Infarction A Machine Learning Study

BACKGROUND: OSA conveys worse clinical outcomes in patients with coronary artery disease. The STOP-BANG score is a simple tool that evaluates the risk of OSA and can be added to the large number of clinical variables and scores that are obtained during the management of patients with myocardial infarction (MI). Currently, machine learning (ML) is able to select and integrate numerous variables to optimize prediction tasks. RESEARCH QUESTION: Can the integration of STOP-BANG score with clinical data and scores through ML better identify patients who experienced an in-hospital cardiovascular event after acute MI? STUDY DESIGN AND METHOD: This is a prospective observational cohort study of 124 patients with acute MI of whom the STOP-BANG score classified 34 as low (27.4%), 30 as intermediate (24.2%), and 60 as high (48.4%) OSA-risk patients who were followed during hospitalization. ML implemented feature selection and integration across 47 variables (including STOP-BANG score, Killip class, GRACE score, and left ventricular ejection fraction) to identify those patients who experienced an in-hospital cardiovascular event (ie, death, ventricular arrhythmias, atrial fibrillation, recurrent angina, reinfarction, stroke, worsening heart failure, or cardiogenic shock) after definitive MI treatment. Receiver operating characteristic curves were used to compare ML performance against STOP-BANG score, Killip class, GRACE score, and left ventricular ejection fraction, independently. RESULTS: There were an increasing proportion of cardiovascular events across the low, intermediate, and high OSA risk groups (P = .005). ML selected 7 accessible variables (ie, Killip class, leukocytes, GRACE score, c reactive protein, oxygen saturation, STOP-BANG score, and N-terminal prohormone of B-type natriuretic peptide); their integration outperformed all comparators (area under the curve, 0.83 [95% CI, 0.74-0.90]; P <.01). INTERPRETATION: The integration of the STOP-BANG score into clinical evaluation (considering Killip class, GRACE score, and simple laboratory values) of subjects who were admitted for an acute MI because of ML can significantly optimize the identification of patients who will experience an in-hospital cardiovascular event

(+)-Catharanthine and (-)-18-methoxycoronaridine induce antidepressant-like activity in mice by differently recruiting serotonergic and norepinephrinergic neurotransmission

The antidepressant-like activity of (+)-catharanthine and (-)-18-methoxycoronaridine [(-)-18-MC] was studied in male and female mice using forced swim (FST) and tail suspension tests (TST). The underlying molecular mechanism was assessed by electrophysiological, radioligand, and functional experiments. The FST results showed that acute administration (40 mg/kg) of (+)-catharanthine or (-)-18-MC induces similar antidepressant-like activity in male and female mice at 1 h and 24 h, whereas the TST results showed a lower effect for (-)-18-MC at 24 h. Repeated treatment at lower dose (20 mg/kg) augmented the efficacy of both congeners. The FST results showed that (-)-18-MC reduces immobility and increases swimming times without changing climbing behavior, whereas (+)-catharanthine reduces immobility time, increases swimming times more markedly, and increases climbing behavior. To investigate the contribution of the serotonin and norepinephrine transporters in the antidepressant effects of (+)-catharanthine and (-)-18-MC, we conducted in vitro radioligand and functional studies. Results obtained demonstrated that (+)-catharanthine inhibits norepinephrine transporter with higher potency/affinity than that for (-)-18-MC, whereas both congeners inhibit serotonin transporter with similar potency/affinity. Moreover, whereas no congener activated/inhibited/potentiated the function of serotonin receptor 3A or serotonin receptor 3AB, both increased serotonin receptor 3A receptor desensitization. Depletion of serotonin decreased the antidepressant-like activity of both congeners, whereas norepinephrine depletion only decreased (+)-catharanthine’s activity. Our study shows that coronaridine congeners induce antidepressant-like activity in a dose- and time-dependent, and sex-independent, manner. The antidepressant-like property of both compounds involves serotonin transporter inhibition, without directly activating/inhibiting serotonin receptors 3, while (+)-catharanthine also mobilizes norepinephrinergic neurotransmission

Topical administration of bosentan prevents retinal neurodegeneration in experimental diabetes

Experimental evidence suggests that endothelin 1 (ET-1) is involved in the development of retinal microvascular abnormalities induced by diabetes. The effects of ET-1 are mediated by endothelin A- and B-receptors (ETA and ETB). Endothelin B-receptors activation mediates retinal neurodegeneration but there are no data regarding the effectiveness of ETB receptor blockage in arresting retinal neurodegeneration induced by diabetes. The main aim of the present study was to assess the usefulness of topical administration of bosentan (a dual endothelin receptor antagonist) in preventing retinal neurodegeneration in diabetic (db/db) mice. For this purpose, db/db mice aged 10 weeks were treated with one drop of bosentan (5 mg/mL, n = 6) or vehicle (n = 6) administered twice daily for 14 days. Six non-diabetic (db/+) mice matched by age were included as the control group. Glial activation was evaluated by immunofluorescence using specific antibodies against glial fibrillary acidic protein (GFAP). Apoptosis was assessed by TUNEL method. A pharmacokinetic study was performed in rabbits. We found that topical administration of bosentan resulted in a significant decrease of reactive gliosis and apoptosis. The results of the pharmacokinetic study suggested that bosentan reached the retina through the trans-scleral route. We conclude that topical administration of bosentan was effective in preventing neurodegeneration in the diabetic retina and, therefore, could be a good candidate to be tested in clinical trials

The periodicity of the η Carinae events

Extensive spectral observations of η Carinae over the last cycle, and particularly around the 2003.5 low-excitation event, have been obtained. The variability of both narrow and broad lines, when combined with data taken from two earlier cycles, reveal a common and well-defined period. We have combined the cycle lengths derived from the many lines in the optical spectrum with those from broad-band X-rays, optical and near-infrared observations, and obtained a period length of Ppres = 2022.7 ± 1.3 d. Spectroscopic data collected during the last 60 yr yield an average period of Pavg = 2020 ± 4 d, consistent with the present-day period. The period cannot have changed by more than ΔP/P = 0.0007 since 1948. This confirms the previous claims of a true, stable periodicity, and gives strong support to the binary scenario. We have used the disappearance of the narrow component of He I 6678 to define the epoch of the Cycle 11 minimum, T0 = JD 245 2819.8. The next event is predicted to occur on 2009 January 11 (±2 d). The dates for the start of the minimum in other spectral features and broad-bands are very close to this date, and have well-determined time-delays from the He I epoch.Facultad de Ciencias Astronómicas y Geofísica

The periodicity of the η Carinae events

Extensive spectral observations of η Carinae over the last cycle, and particularly around the 2003.5 low-excitation event, have been obtained. The variability of both narrow and broad lines, when combined with data taken from two earlier cycles, reveal a common and well-defined period. We have combined the cycle lengths derived from the many lines in the optical spectrum with those from broad-band X-rays, optical and near-infrared observations, and obtained a period length of Ppres = 2022.7 ± 1.3 d. Spectroscopic data collected during the last 60 yr yield an average period of Pavg = 2020 ± 4 d, consistent with the present-day period. The period cannot have changed by more than ΔP/P = 0.0007 since 1948. This confirms the previous claims of a true, stable periodicity, and gives strong support to the binary scenario. We have used the disappearance of the narrow component of He I 6678 to define the epoch of the Cycle 11 minimum, T0 = JD 245 2819.8. The next event is predicted to occur on 2009 January 11 (±2 d). The dates for the start of the minimum in other spectral features and broad-bands are very close to this date, and have well-determined time-delays from the He I epoch.Facultad de Ciencias Astronómicas y Geofísica

DR6 as a Diagnostic and Predictive Biomarker in Adult Sarcoma

The Death Receptor 6 (DR6) protein is elevated in the serum of ovarian cancer patients. We tested DR6 serum protein levels as a diagnostic/predictive biomarker in several epithelial tumors and sarcomas.DR6 gene expression profiles were screened in publically available arrays of solid tumors. A quantitative immunofluorescent western blot analysis was developed to test the serum of healthy controls and patients with sarcoma, uterine carcinosarcoma, bladder, liver, and pancreatic carcinomas. Change in DR6 serum levels was used to assay the ability of DR6 to predict the response to therapy of sarcoma patients.DR6 mRNA is highly expressed in all tumor types assayed. Western blot analysis of serum DR6 protein demonstrated high reproducibility (r = 0.97). Compared to healthy donor controls, DR6 serum levels were not elevated in patients with uterine carcinosarcoma, bladder, liver, or pancreatic cancers. Serum DR6 protein levels from adult sarcoma patients were significantly elevated (p<0.001). This was most evident for patients with synovial sarcoma. Change in serum DR6 levels during therapy correlated with clinical benefit from therapy (sensitivity 75%, and positive predictive value 87%).DR6 may be a clinically useful diagnostic and predictive serum biomarker for some adult sarcoma subtypes.Diagnosis of sarcoma can be difficult and can lead to improper management of these cancers. DR6 serum protein may be a tool to aid in the diagnosis of some sarcomatous tumors to improve treatment planning. For patients with advanced disease, rising DR6 levels predict non-response to therapy and may expedite therapeutic decision making and reduce reliance on radiologic imaging