Dysregulation of renal transient receptor potential melastatin 6/7 but not paracellin-1 in aldosterone-induced hypertension and kidney damage in a model of hereditary hypomagnesemia

Rationale Hyperaldosteronism, important in hypertension, is associated with electrolyte alterations, including hypomagnesemia, through unknown mechanisms. Objective To test whether aldosterone influences renal Mg(2+) transporters, (transient receptor potential melastatin (TRPM) 6, TRPM7, paracellin-1) leading to hypomagnesemia, hypertension and target organ damage and whether in a background of magnesium deficiency, this is exaggerated. Methods and results Aldosterone effects in mice selectively bred for high-normal (MgH) or low (MgL) intracellular Mg(2+) were studied. Male MgH and MgL mice received aldosterone (350 mu g/kg per day, 3 weeks). SBP was elevated in MgL. Aldosterone increased blood pressure and albuminuria and increased urinary Mg(2+) concentration in MgH and MgL, with greater effects in MgL. Activity of renal TRPM6 and TRPM7 was lower in vehicle-treated MgL than MgH. Aldosterone increased activity of TRPM6 in MgH and inhibited activity in MgL. TRPM7 and paracellin-1 were unaffected by aldosterone. Aldosterone-induced albuminuria in MgL was associated with increased renal fibrosis, increased oxidative stress, activation of mitogen-activated protein kinases and nuclear factor-NF-kappa B and podocyte injury. Mg(2+) supplementation (0.75% Mg(2+)) in aldosterone-treated MgL normalized plasma Mg(2+), increased TRPM6 activity and ameliorated hypertension and renal injury. Hence, in a model of inherited hypomagnesemia, TRPM6 and TRPM7, but not paracellin-1, are downregulated. Aldosterone further decreased TRPM6 activity in hypomagnesemic mice, a phenomenon associated with hypertension and kidney damage. Such effects were prevented by Mg(2+) supplementation. Conclusion Amplified target organ damage in aldosterone-induced hypertension in hypomagnesemic conditions is associated with dysfunctional Mg(2+)-sensitive renal TRPM6 channels. Novel mechanisms for renal effects of aldosterone and insights into putative beneficial actions of Mg(2+), particularly in hyperaldosteronism, are identified. J Hypertens 29: 1400-1410 (C) 2011 Wolters Kluwer Health vertical bar Lippincott Williams & Wilkins.

Involvement of NO in the inhibitory effect of Calotropis procera latex protein fractions on leukocyte rolling, adhesion and infiltration in rat peritonitis model

Aim of the study: The latex of Calotropis procera has been used in the traditional medicinal system for the treatment of leprosy, ulcers, tumors, piles and diseases of liver, spleen, abdomen and toothache. it comprises of a non-dialyzable protein fraction (LP) that exhibits anti-inflammatory properties and a dialyzable fraction (DF) exhibiting pro-inflammatory properties. The present study was carried out to evaluate the effect of LP sub-fractions on neutrophil functions and nociception in rodent models and to elucidate the mediatory role of nitric oxide (NO). Material and methods: The LP was subjected to ion exchange chromatography and the effect of its three sub-fractions (LP(PI), LP(PII), and LP(PIII)) thus obtained was evaluated on leukocyte functions in the rat peritonitis model and on nociception in the mouse model. Results: LP sub-fractions exhibit distinct protein profile and produce a significant decrease in the carrageenan and DF induced neutrophil influx and exhibit anti-nociceptive property. The LP and its sub-fractions produced a marked reduction in the number of rolling and adherent leukocytes in the mesenteric microvasculature as revealed by intravital microscopy. The anti-inflammatory effect of LP(PI), the most potent anti-inflammatory fraction of LP, was accompanied by an increase in the serum levels of NO. Further, our study shows that NO is also involved in the inhibitory effect of LP(PI) on neutrophil influx. Conclusions: Our study shows that LP fraction of Calotropis procera comprises of three distinct sets of proteins exhibiting anti-inflammatory and anti-nociceptive properties of which LP(PI) was most potent in inhibiting neutrophil functions and its effects are mediated through NO production. (C) 2009 Elsevier Ireland Ltd. All rights reserved.

Differential regulation of TRP channels in a rat model of neuropathic pain

Neuropathic pain is a chronic disease resulting from dysfunction of the nervous system often due to peripheral nerve injury. Hypersensitivity to sensory Stimuli (mechanical, thermal or chemical) is a common source of pain in patients and ion channels involved in detecting these Stimuli are possible candidates for inducing and/or maintaining the pain. Transient receptor potential (TRP) channels expressed on nociceptors respond to different sensory stimuli and a few of them have been studied previously in the models of neuropathic pain. Using real-time PCR for quantification of all known TRP channels we identified several TRP channels, which have not been associated with nociception OF neuropathic pain before, to be expressed in the DRG and to be differentially regulated after spared nerve injury (SNI). Of all TRP channel members, TRPML3 showed the most dramatic change in animals exhibiting neuropathic pain behaviour compared to control animals. fit situ hybridisation showed a widespread increase of expression ill neurons of small, medium and large cell sizes, indicating expression ill multiple subtypes. Co-localisation of TRPML3 with CGRP, NF200 and IB4 staining confirmed a broad Subtype distribution. Expression studies during development showed that TRPML3 is all embryonic channel that is induced upon nerve injury in three different nerve injury models investigated. Thus. the current results link for the first time a re-expression of TRPML3 with the development of neuropathic pain conditions. In addition, decreased mRNA levels after SNI were seen for TRPM6, TRPM8, TRPV1, TRPA1, TRPC3, TRPC4 and TRPC5. (C) 2009 International Association for the Study of Pain. Published by Elsevier B.V. All rights reserved.

Chelatable zinc modulates excitability and seizure duration in the amygdala rapid kindling model

Zinc is present in high concentration in many structures of the limbic circuitry, however the role of zinc as a neuromodulator in such synapses is stilt uncertain. In this work, we verified the effects of zinc chelation in an animal model of epileptogenesis induced by amygdala rapid kindling. The basolateral. amygdala was electrically stimulated ten times per day for 2 days. A single stimulus was applied on the third day. Stimulated animals received injections of PBS or the zinc chelator diethildythiocarbamate acid (DEDTC) before each stimulus series. Animals were monitored with video-EEG and were perfused 3 h after the last stimulus for subsequent neo-Timm and Ftuoro-Jade B analysis. Zinc chelation decreased the duration of both behavioral seizures and electrical after-discharges, and also decreased the EEG spikes frequency, without changing the progression of behavioral seizure severity. These results indicate that the zinc ion may have a facilitatory role during kindling progression. (c) 2008 Elsevier B.V. All rights reserved.

A general hazard model for lifetime data in the presence of cure rate

Historically, the cure rate model has been used for modeling time-to-event data within which a significant proportion of patients are assumed to be cured of illnesses, including breast cancer, non-Hodgkin lymphoma, leukemia, prostate cancer, melanoma, and head and neck cancer. Perhaps the most popular type of cure rate model is the mixture model introduced by Berkson and Gage [1]. In this model, it is assumed that a certain proportion of the patients are cured, in the sense that they do not present the event of interest during a long period of time and can found to be immune to the cause of failure under study. In this paper, we propose a general hazard model which accommodates comprehensive families of cure rate models as particular cases, including the model proposed by Berkson and Gage. The maximum-likelihood-estimation procedure is discussed. A simulation study analyzes the coverage probabilities of the asymptotic confidence intervals for the parameters. A real data set on children exposed to HIV by vertical transmission illustrates the methodology.

Effects of cannabidiol on amphetamine-induced oxidative stress generation in an animal model of mania

Cannabidiol (CBD), a Cannabis sativa constituent, may present a pharmacological profile similar to mood stabilizing drugs, in addition to anti-oxidative and neuroprotective properties. The present study aims to directly investigate the effects of CBD in an animal model of mania induced by D-amphetamine (D-AMPH). In the first model (reversal treatment), rats received saline or D-AMPH (2 mg/kg) once daily intraperitoneal (i.p.) for 14 days, and from the 8th to the 14th day, they were treated with saline or CBD (15, 30 or 60 mg/kg) i.p. twice a day. In the second model (prevention treatment), rats were pretreated with saline or CBD (15, 30, or 60 mg/kg) regime i.p. twice a day, and from the 8th to the 14th day, they also received saline or D-AMPH i.p. once daily. In the hippocampus CBD (15 mg/kg) reversed the D-AMPH-induced damage and increased (30 mg/kg) brain-derived neurotrophic factor (BDNF) expression. In the second experiment, CBD (30 or 60 mg/kg) prevented the D-AMPH-induced formation of carbonyl group in the prefrontal cortex. In the hippocampus and striatum the D-AMPH-induced damage was prevented by CBD (15, 30 or 60 mg/kg). At both treatments CBD did not present any effect against D-AMPH-induced hyperactivity. In conclusion, we could not observe effects on locomotion, but CBD protect against D-AMPH-induced oxidative protein damage and increased BDNF levels in the reversal model and these effects vary depending on the brain regions evaluated and doses of CBD administered.

Effects of beta-carboline harmine on behavioral and physiological parameters observed in the chronic mild stress model: Further evidence of antidepressant properties

The chronic mild stress (CMS) model has been used as an animal model of depression which induces anhedonic behavior in rodents. The present study was aimed to evaluate the behavioral and physiological effects of administration of P-carboline harmine in rats exposed to CMS Procedure. To this aim, after 40 days of exposure to CMS procedure, rats were treated with harmine (15 mg/kg/day) for 7 days. In this study, sweet food consumption, adrenal gland weight, adrenocorticotrophin hormone (ACTH) levels, and hippocampal brain-derived-neurotrophic factor (BDNF) protein levels were assessed. Our findings demonstrated that chronic stressful situations induced anhedonia, hypertrophy of adrenal gland weight, increase ACTH circulating levels in rats and increase BDNF protein levels. Interestingly, treatment with harmine reversed anhedonia, the increase of adrenal gland weight, normalized ACTH circulating levels and BDNF protein levels. Finally, these findings further support the hypothesis that harmine could be a new pharmacological tool for the treatment of depression. (C) 2009 Elsevier Inc. All rights reserved.

The melatonin action on stromal stem cells within pericryptal area in colon cancer model under constant light

Constant light (LL) is associated with high incidence of colon cancer. MLT supplementation was related to the significant control of preneoplastic patterns. We sought to analyze preneoplastic patterns in colon tissue from animals exposed to LL environment (14 days; 300 lx), MLT-supplementation (10 mg/kg/day) and DMH-treatment (1,2 dimethylhydrazine; 125 mg/kg). Rodents were sacrificed and MLT serum levels were measured by radioimmunoassay. Our results indicated that LL induced ACF development (p < 0.001) with a great potential to increase the number of CD133(+) and CD68(+) cells (p < 0.05 and p < 0.001). LL also increased the proliferative process (PCNA-Li; p < 0.001) as well as decreased caspase-3 protein (p < 0.001), related to higher COX-2 protein expression (p < 0.001) within pericryptal colonic stroma (PCCS). However, MLT-supplementation controlled the development of dysplastic ACF (p < 0.001) diminishing preneoplastic patterns into PCCS as CD133 and CD68 (p < 0.05 and p < 0.001). These events were relative to decreased PCNA-Li index and higher expression of caspase-3 protein. Thus, MLT showed a great potential to control the preneoplastic patterns induced by LL. (C) 2011 Elsevier Inc. All rights reserved.

Neuronal maturation in an experimental model of brain tissue heterotopia in the lung

Neural maturation involves diverse interaction and signaling mechanisms that are essential to the development of the nervous system. However, little is known about the development of neurons in heterotopic brain tissue in the lung, a rare abnormality observed in malformed babies and fetuses. The aim of this study was to identify the neurons and to investigate their maturation in experimental brain tissue heterotopia during fetal and neonatal periods. The fetuses from 24 pregnant female Swiss mice were used to induce brain tissue heterotopia on the 15th gestational day. Briefly, the brain of one fetus of each dam was extracted, disaggregated, and injected into the right hemithorax of siblings. Six of these fetuses with pulmonary brain tissue implantation were collected on the 18th gestational day (group E18), and six others were collected on the 8th postnatal day (group P8). The brain of each fetus from dams not submitted to any experimental procedure was collected on the 18th gestational day (group CE18) and on the 8th postnatal day (group CP8) to serve as a control for neuronal quantitation and maturation. Immunohistochemical staining of NeuN was used to assess neuron quantity and maturation. The NeuN labeling index was greater in the postnatal period than in the fetal period for the experimental and control groups (138 > E18 and CP8 > CE18), although there were fewer neurons in experimental than in control groups (P8 < CP8 and El 8 < CE1 8) (P < 0.005). These results indicate that fetal neuroblasts/neurons not only survive a dramatic event such as mechanical disaggregation, in the same way as it happens in human cases, but also they retain their development in heterotopia, irrespective of local tissue influences.

beta 1 Integrin and VEGF expression in an experimental model of brain tissue heterotopia in the lung

Integrins and vascular endothelial growth factor (VEGF) are crucially involved in interaction, proliferation, migration, and survival of the cells. However, there is no report in the literature about beta 1 integrin and VEGF expression in heterotopic brain tissue. The aim of this study was to assess beta 1 integrin and VEGF expression in experimental brain tissue heterotopia in the lung during both fetal and neonatal periods. Twenty-four pregnant female Swiss mice were used to induce brain tissue heterotopia on the 15th gestational day. Briefly, the brain of one fetus of each dam was extracted, disaggregated, and injected into the right hemithorax of siblings. Six of these fetuses with pulmonary brain tissue implantation were collected on the 18th gestational day (group E18) and six other on the eighth postnatal day (group P8). Immunohistochemistry of the fetal trunks showed implantation of glial fibrillary acidic protein- and neuronal nuclei-positive heterotopic brain tissue, which were also positive for beta 1 integrin and VEGF in both groups E18 and P8. These results indicate that brain tissue heterotopia during fetal and postnatal period is able to complete integration with the lung tissue as well as to induce vascular proliferation which are the necessary steps for a successful implantation.

An Experimental Model of Meningoencephalomyelitis by Rocio Flavivirus in Balb/C Mice: Inflammatory Response, Cytokine Production, and Histopathology

Rocio virus (ROCV) is a flavivirus, probably transmitted by Culex mosquitoes and maintained in nature as a zoonosis of wild birds. Rocio virus caused a human epidemic of severe encephalitis that lasted from 1973 to 1980 in the Ribeira valley, in the southeastern coast of Brazil. After this outbreak, serologic evidence of ROCV circulation has been reported and public health authorities are concerned about a return of ROCV outbreaks in Brazil. We show here a study on the pathogenesis and the physiopathology of ROCV disease in the central nervous system of a Balb/C young adult mice experimental model. The animals were intraperitoneally infected by ROCV and followed from 0 to 9 days after infection, when all of them died. Nervous tissue samples were collected from infected animals for immunohistochemistry and molecular biology analysis. We observed the virus in the central nervous system, the inflammatory changes induced by Th1 and Th2 cytokines, and the final irreversible damage of nervous tissues by neuronal degeneration and apoptosis. These findings can help to better understand the pathogenesis and physiopathology of the human meningoencephalomyelitis by ROCV and other flaviviruses.

Analysis of the Nicotiana tabacum Stigma/Style Transcriptome Reveals Gene Expression Differences between Wet and Dry Stigma Species

The success of plant reproduction depends on pollen-pistil interactions occurring at the stigma/style. These interactions vary depending on the stigma type: wet or dry. Tobacco (Nicotiana tabacum) represents a model of wet stigma, and its stigmas/styles express genes to accomplish the appropriate functions. For a large-scale study of gene expression during tobacco pistil development and preparation for pollination, we generated 11,216 high-quality expressed sequence tags (ESTs) from stigmas/styles and created the TOBEST database. These ESTs were assembled in 6,177 clusters, from which 52.1% are pistil transcripts/genes of unknown function. The 21 clusters with the highest number of ESTs (putative higher expression levels) correspond to genes associated with defense mechanisms or pollen-pistil interactions. The database analysis unraveled tobacco sequences homologous to the Arabidopsis (Arabidopsis thaliana) genes involved in specifying pistil identity or determining normal pistil morphology and function. Additionally, 782 independent clusters were examined by macroarray, revealing 46 stigma/style preferentially expressed genes. Real-time reverse transcription-polymerase chain reaction experiments validated the pistil-preferential expression for nine out of 10 genes tested. A search for these 46 genes in the Arabidopsis pistil data sets demonstrated that only 11 sequences, with putative equivalent molecular functions, are expressed in this dry stigma species. The reverse search for the Arabidopsis pistil genes in the TOBEST exposed a partial overlap between these dry and wet stigma transcriptomes. The TOBEST represents the most extensive survey of gene expression in the stigmas/styles of wet stigma plants, and our results indicate that wet and dry stigmas/styles express common as well as distinct genes in preparation for the pollination process.

Temperature safety profile of laparoscopic devices: Harmonic ACE (ACE), Ligasure V (LV), and plasma trisector (PT)

Background Reports of iatrogenic thermal injuries during laparoscopic surgery using new generation vessel-sealing devices, as well as anecdotal reports of hand burn injuries during hand-assisted surgeries, have evoked questions about the temperature safety profile and the cooling properties of these instruments. Methods This study involved video recording of temperatures generated by different instruments (Harmonic ACE [ACE], Ligasure V [LV], and plasma trisector [PT]) applied according the manufacturers` pre-set settings (ACE setting 3; LV 3 bars, and the PT TR2 50W). The video camera used was the infrared Flex Cam Pro directed to three different types of swine tissue: (1) peritoneum (P), (2) mesenteric vessels (MV), and (3) liver (L). Activation and cooling temperature and time were measured for each instrument. Results The ACE device produced the highest temperatures (195.9 degrees +/- 14.5 degrees C) when applied against the peritoneum, and they were significantly higher than the other instruments (LV = 96.4 degrees +/- 4.1 degrees C, and PT = 87 degrees +/- 2.2 degrees C). The LV and PT consistently yielded temperatures that were < 100 degrees C independent of type of tissue or ""on""/ ""off"" mode. Conversely, the ACE reached temperatures higher than 200 degrees C, with a surprising surge after the instrument was deactivated. Moreover, temperatures were lower when the ACE was applied against thicker tissue (liver). The LV and PT cooling times were virtually equivalent, but the ACE required almost twice as long to cool. Conclusions The ACE increased the peak temperature after deactivation when applied against thick tissue (liver), and the other instruments inconsistently increased peak temperatures after they were turned off, requiring few seconds to cool down. Moreover, the ACE generated very high temperatures (234.5 degrees C) that could harm adjacent tissue or the surgeon`s hand on contact immediately after deactivation. With judicious use, burn injury from these instruments can be prevented during laparoscopic procedures. Because of the high temperatures generated by the ACE device, particular care should be taken when it is used during laparoscopy.