Acetic acid- and phenyl-p-benzoquinone-induced overt pain-like behavior depends on spinal activation of MAP kinases, PI3K and microglia in mice

The acetic acid and phenyl-p-benzoquinone are easy and fast screening models to access the activity of novel candidates as analgesic drugs and their mechanisms. These models induce a characteristic and quantifiable overt pain-like behavior described as writhing response or abdominal contortions. The knowledge of the mechanisms involved in the chosen model is a crucial step forward demonstrating the mechanisms that the candidate drug would inhibit because the mechanisms triggered in that model will be addressed. Herein, it was investigated the role of spinal mitogen-activated protein (MAP) kinases ERK (extracellular signal-regulated kinase), JNK (Jun N-terminal Kinase) and p38, PI3K (phosphatidylinositol 3-kinase) and microglia in the writhing response induced by acetic acid and phenyl-p-benzoquinone, and flinch induced by formalin in mice. Acetic acid and phenyl-p-benzoquinone induced significant writhing response over 20 min. The nociceptive response in these models were significantly and in a dose-dependent manner reduced by intrathecal pre-treatment with ERK (PD98059), JNK (SB600125), p38 (SB202190) or PI3K (wortmannin) inhibitors. Furthermore, the co-treatment with MAP kinase and PI3K inhibitors, at doses that were ineffective as single treatment, significantly inhibited acetic acid- and phenyl-p-benzoquinone-induced nociception. The treatment with microglia inhibitors minocycline and fluorocitrate also diminished the nociceptive response. Similar results were obtained in the formalin test. Concluding. MAP kinases and PI3K are important spinal signaling kinases in acetic acid and phenyl-p-benzoquinone models of overt pain-like behavior and there is also activation of spinal microglia indicating that it is also important to determine whether drugs tested in these models also modulate such spinal mechanisms. (C) 2012 Elsevier Inc. All rights reserved.

Lack of beta(2)-AR improves exercise capacity and skeletal muscle oxidative phenotype in mice

beta(2)-adrenergic receptor (beta(2)-AR) agonists have been used as ergogenics by athletes involved in training for strength and power in order to increase the muscle mass. Even though anabolic effects of beta(2)-AR activation are highly recognized, less is known about the impact of beta(2)-AR in endurance capacity. We presently used mice lacking beta(2)-AR [beta(2)-knockout (beta(2) KO)] to investigate the role of beta(2)-AR on exercise capacity and skeletal muscle metabolism and phenotype. beta(2) KO mice and their wild-type controls (WT) were studied. Exercise tolerance, skeletal muscle fiber typing, capillary-to-fiber ratio, citrate synthase activity and glycogen content were evaluated. When compared with WT, beta 2KO mice displayed increased exercise capacity (61%) associated with higher percentage of oxidative fibers (21% and 129% of increase in soleus and plantaris muscles, respectively) and capillarity (31% and 20% of increase in soleus and plantaris muscles, respectively). In addition, beta 2KO mice presented increased skeletal muscle citrate synthase activity (10%) and succinate dehydrogenase staining. Likewise, glycogen content (53%) and periodic acid-Schiff staining (glycogen staining) were also increased in beta 2KO skeletal muscle. Altogether, these data provide evidence that disruption of beta(2)AR improves oxidative metabolism in skeletal muscle of beta 2KO mice and this is associated with increased exercise capacity.

Pentraxin 3 accelerates lung injury in high tidal volume ventilation in mice

Mechanical ventilation is the major cause of iatrogenic lung damage in intensive care units. Although inflammation is known to be involved in ventilator-induced lung injury (VILI), several aspects of this process are still unknown. Pentraxin 3 (PTX3) is an acute phase protein with important regulatory functions in inflammation which has been found elevated in patients with acute respiratory distress syndrome. This study aimed at investigating the direct effect of PTX3 production in the pathogenesis of VILI. Genetically modified mice deficient and that over express murine Ptx3 gene were subjected to high tidal volume ventilation (V-T = 45 mL/kg, PEEPzero). Morphological changes and time required for 50% increase in respiratory system elastance were evaluated. Gene expression profile in the lungs was also investigated in earlier times in Ptx3-overexpressing mice. Ptx3 knockout and wild-type mice developed same lung injury degree in similar times (156 +/- 42 min and 148 +/- 41 min, respectively: p = 0.8173). However, Ptx3 overexpression led to a faster development of VILI in Ptx3-overexpressing mice (77 +/- 29 min vs 118 +/- 41 min, p = 0.0225) which also displayed a faster kinetics of Il1b expression and elevated Ptx3, Cxcl1 and Ccl2 transcripts levels in comparison with wild-type mice assessed by quantitative real-time polymerase chain reaction. Ptx3 deficiency did not impacted the time for VILI induced by high tidal volume ventilation but Ptx3-overexpression increased inflammatory response and reflected in a faster VILI development. (C) 2012 Elsevier Ltd. All rights reserved.

Anti-inflammatory Effects of Aerobic Exercise in Mice Exposed to Air Pollution

VIEIRA, R. D. P., A. C. TOLEDO, L. B. SILVA, F. M. ALMEIDA, N. R. DAMACENO-RODRIGUES, E. G. CALDINI, A. B. G. SANTOS, D. H. RIVERO, D. C. HIZUME, F. D. T. Q. S. LOPES, C. R. OLIVO, H. C. CASTRO-FARIA-NETO, M. A. MARTINS, P. H. N. SALDIVA, and M. DOLHNIKOFF. Anti-inflammatory Effects of Aerobic Exercise in Mice Exposed to Air Pollution. Med. Sci. Sports Exerc., Vol. 44, No. 7, pp. 1227-1234, 2012. Purpose: Exposure to diesel exhaust particles (DEP) results in lung inflammation. Regular aerobic exercise improves the inflammatory status in different pulmonary diseases. However, the effects of long-term aerobic exercise on the pulmonary response to DEP have not been investigated. The present study evaluated the effect of aerobic conditioning on the pulmonary inflammatory and oxidative responses of mice exposed to DEP. Methods: BALB/c mice were subjected to aerobic exercise five times per week for 5 wk, concomitantly with exposure to DEP (3 mg.mL (1); 10 mu L per mouse). The levels of exhaled nitric oxide, reactive oxygen species, cellularity, interleukin 6 (IL-6), and tumor necrosis factor alpha (TNF-alpha) were analyzed in bronchoalveolar lavage fluid, and the density of neutrophils and the volume proportion of collagen fibers were measured in the lung parenchyma. The cellular density of leukocytes expressing IL-1 beta, keratinocyte chemoattractant (KC), and TNF-alpha in lung parenchyma was evaluated with immunohistochemistry. The levels of IL-1 beta, KC, and TNF-alpha were also evaluated in the serum. Results: Aerobic exercise inhibited the DEP-induced increase in the levels of reactive oxygen species (P < 0.05); exhaled nitric oxide (P < 0.01); total (P < 0.01) and differential cells (P < 0.01); IL-6 and TNF-alpha levels in bronchoalveolar lavage fluid (P < 0.05); the level of neutrophils (P < 0.001); collagen density in the lung parenchyma (P < 0.05); the levels of IL-6, KC, and TNF-alpha in plasma (P < 0.05); and the expression of IL-1 beta, KC, and TNF-alpha by leukocytes in the lung parenchyma (P < 0.01). Conclusions: We conclude that long-term aerobic exercise presents protective effects in a mouse model of DEP-induced lung inflammation. Our results indicate a need for human studies that evaluate the pulmonary responses to aerobic exercise chronically performed in polluted areas.

Voriconazole, Combined with Amphotericin B, in the Treatment for Pulmonary Cryptococcosis Caused by C. neoformans (Serotype A) in Mice with Severe Combined Immunodeficiency (SCID)

Cryptococcosis is a subacute or chronic systemic mycosis with a cosmopolitan nature, caused by yeast of the genus Cryptococcus neoformans. The model of systemic cryptococcosis in mice with severe combined immunodeficiency (SCID) is useful for immunological and therapeutic study of the disease in immunodeficient hosts. Amphotericin B, fluconazole and flucytosine are the drugs most commonly used to treat cryptococcosis. Voriconazole is a triazole with high bioavailability, large distribution volume, and excellent penetration of the central nervous system. The objective of this study was to evaluate treatment with amphotericin B (AMB), voriconazole (VRC), and AMB, used in combination with VRC, of experimental pulmonary cryptococcosis in a murine model (SCID). The animals were inoculated intravenously (iv) with a solution containing 3.0 x 10(5) viable cells of C. neoformans ATCC 90112, (serotype A). Treatments were performed with amphotericin B (1.5 mg/kg/day), voriconazole (40.0 mg/kg/day) and AMB (1.5 mg/kg/day) combined with VRC (40.0 mg/kg/day); began 1 day after the initial infection; were daily; and lasted 15 days. Evaluations were performed using analysis of the survival curve and isolation of yeast in the lung tissue. There was a significant increase in survival in groups treated with AMB combined with VRC, compared with the untreated group and groups receiving other treatments (P < 0.05). In the group treated only with VRC and AMB combined with VRC, there was a significant reduction (P < 0.05) in the isolation of C. neoformans in lung tissue. Amphotericin B combined with voriconazole may be an effective alternative to increasing survival and may reduce yeast in the lung tissue of mice with pulmonary cryptococcosis and SCID.

Experimental arthritis exacerbates Aggregatibacter actinomycetemcomitans-induced periodontitis in mice

Aim This study aimed to investigate whether chronic antigen-induced arthritis (AIA) influences infection-induced periodontitis (PD) in mice and whether PD modifies the clinical course of AIA. The contribution of anti-TNF-a therapy was also evaluated. Materials and methods The PD was induced in C57BL/6 mice by oral infection with Aggregatibacter actinomycetemcomitans. AIA was induced after infection. Anti-TNF-a and chlorhexidine therapies were used to investigate the role of TNF-a and oral infection on PD and AIA interaction. Maxillae, knee joints, lymph nodes and serum samples were used for histomorphometric, immunoenzymatic and/or real time-PCR analyses. Results Antigen-induced arthritis exacerbated alveolar bone loss triggered by PD infection. In contrast, PD did not influence AIA in the evaluated time-points. PD exacerbation was associated with enhanced production of IFN-? in maxillae and expression of the Th1 transcription factor tBET in submandibular lymph nodes. Increased serum levels of IL-6 and C-reactive protein were also detected. Anti-TNF-a and antiseptic therapies prevented the development and exacerbation of infectious-PD. Anti-TNF-a therapy also resulted in reduced expression of IFN-?, TNF-a and IL-17 in maxillae. Conclusions Altogether, the current results indicate that the exacerbation of infection-induced PD by arthritis is associated with an alteration in lymphocyte polarization pattern and increased systemic immunoreactivity. This process was ameliorated by anti-TNF-a and antiseptic therapies.

Endothelin-1 induces neutrophil recruitment in adaptive inflammation via TNF alpha and CXCL1/CXCR2 in mice

Endothelin mediates neutrophil recruitment during innate inflammation. Herein we address whether endothelin-1 (ET-1) is involved in neutrophil recruitment in adaptive inflammation in mice, and its mechanisms. Pharmacological treatments were used to determine the role of endothelin in neutrophil recruitment to the peritoneal cavity of mice challenged with antigen (ovalbumin) or ET-1. Levels of ET-1, tumour necrosis factor a (TNF alpha), and CXC chemokine ligand 1 (CXCL1) were determined by enzyme-linked immunosorbent assay. Neutrophil migration and flow cytometry analyses were performed 4 h after the intraperitoneal stimulus. ET-1 induced dose-dependent neutrophil recruitment to the peritoneal cavity. Treatment with the non-selective ETA/ETB receptor antagonist bosentan, and selective ETA or ETB receptor antagonists BQ-123 or BQ-788, respectively, inhibited ET-1- and ovalbumin-induced neutrophil migration to the peritoneal cavity. In agreement with the above, the antigen challenge significantly increased levels of ET-1 in peritoneal exudates. The ET-1- and ovalbumin-induced neutrophil recruitment were reduced in TNFR1 deficient mice, and by treatments targeting CXCL1 or CXC chemokine receptor 2 (CXCR2); further, treatment with bosentan, BQ-123, or BQ-788 inhibited ET-1- and antigen-induced production of TNFa and CXCL1. Furthermore, ET-1 and ovalbumin challenge induced an increase in the number of cells expressing the Gr1(+) markers in the granulocyte gate, CD11c+ markers in the monocyte gate, and CD4(+) and CD45(+) (B220) markers in the lymphocyte gate in an ETA-and ETB-dependent manner, as determined by flow cytometry analysis, suggesting that ET-1 might be involved in the recruitment of neutrophils and other cells in adaptive inflammation. Therefore, the present study demonstrates that ET-1 is an important mediator for neutrophil recruitment in adaptive inflammation via TNF alpha and CXCL1/CXCR2-dependent mechanism.

MIF induces osteoclast differentiation and contributes to progression of periodontal disease in mice

Periodontal disease (PD) is a chronic inflammatory and alveolar bone destructive disease triggered by microorganisms from the oral biofilm. Oral inoculation of mice with the periodontopathogen Aggregatibacter actinomycetemcomitans (Aa) induces marked alveolar bone loss and local production of inflammatory mediators, including Macrophage Migration Inhibitory Factor (MW). The role of MW for alveolar bone resorption during PD is not known. In the present study, experimental PD was induced in BALB/c wild-type mice (WT) and MW knockout mice (MIF-/-) through oral inoculation of Aa. Despite enhanced number of bacteria, MIF-/- mice had reduced infiltration of TRAP-positive cells and reduced alveolar bone loss. This was associated with decreased neutrophil accumulation and increased levels of IL-10 in periodontal tissues. TNF-alpha production was similar in both groups. In vitro, LPS from Aa enhanced osteoclastic activity in a MIF-dependent manner. In conclusion, MIF has role in controlling bacterial growth in the context of PD but contributes more significantly to the progression of bone loss during PD by directly affecting differentiation and activity of osteoclasts. (C) 2011 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

Chronic cold stress in mice induces a regulatory phenotype in macrophages: Correlation with increased 11 beta-hydroxysteroid dehydrogenase expression

Susceptibility to infections, autoimmune disorders and tumor progression is strongly influenced by the activity of the endocrine and nervous systems in response to a stressful stimulus. When the adaptive system is switched on and off efficiently, the body is able to recover from the stress imposed. However, when the system is activated repeatedly or the activity is sustained, as during chronic or excessive stress, an allostatic load is generated, which can lead to disease over long periods of time. We investigated the effects of chronic cold stress in BALB/c mice (4 degrees C/4 h daily for 7 days) on functions of macrophages. We found that chronic cold stress induced a regulatory phenotype in macrophages, characterized by diminished phagocytic ability, decreased TNF-alpha and IL-6 and increased IL-10 production. In addition, resting macrophages from mice exposed to cold stress stimulated spleen cells to produce regulatory cytokines, and an immunosuppressive state that impaired stressed mice to control Trypanosoma cruzi proliferation. These regulatory effects correlated with an increase in macrophage expression of 11 beta-hydroxysteroid dehydrogenase, an enzyme that converts inactive glucocorticoid into its active form. As stress is a common aspect of modern life and plays a role in the etiology of many diseases, the results of this study are important for improving knowledge regarding the neuro-immune-endocrine interactions that occur during stress and to highlight the role of macrophages in the immunosuppression induced by chronic stress. (C) 2011 Elsevier Inc. All rights reserved.

Knock out of neuronal nitric oxide synthase exacerbates intestinal ischemia/reperfusion injury in mice

Recent investigation of the intestine following ischemia and reperfusion (I/R) has revealed that nitric oxide synthase (NOS) neurons are more strongly affected than other neuron types. This implies that NO originating from NOS neurons contributes to neuronal damage. However, there is also evidence of the neuroprotective effects of NO. In this study, we compared the effects of I/R on the intestines of neuronal NOS knockout (nNOS(-/-)) mice and wild-type mice. I/R caused histological damage to the mucosa and muscle and infiltration of neutrophils into the external muscle layers. Damage to the mucosa and muscle was more severe and greater infiltration by neutrophils occurred in the first 24 h in nNOS(-/-) mice. Immunohistochemistry for the contractile protein, alpha-smooth muscle actin, was used to evaluate muscle damage. Smooth muscle actin occurred in the majority of smooth muscle cells in the external musculature of normal mice but was absent from most cells and was reduced in the cytoplasm of other cells following I/R. The loss was greater in nNOS(-/-) mice. Basal contractile activity of the longitudinal muscle and contractile responses to nerve stimulation or a muscarinic agonist were reduced in regions subjected to I/R and the effects were greater in nNOS(-/-) mice. Reductions in responsiveness also occurred in regions of operated mice not subjected to I/R. This is attributed to post-operative ileus that is not significantly affected by knockout of nNOS. The results indicate that deleterious effects are greater in regions subjected to I/R in mice lacking nNOS compared with normal mice, implying that NO produced by nNOS has protective effects that outweigh any damaging effect of this free radical produced by enteric neurons.

Progression to Adrenocortical Tumorigenesis in Mice and Humans through Insulin-Like Growth Factor 2 and beta-Catenin

Dysregulation of the WNT and insulin-like growth factor 2 (IGF2) signaling pathways has been implicated in sporadic and syndromic forms of adrenocortical carcinoma (ACC). Abnormal beta-catenin staining and CTNNB1 mutations are reported to be common in both adrenocortical adenoma and ACC, whereas elevated IGF2 expression is associated primarily with ACC. To better understand the contribution of these pathways in the tumorigenesis of ACC, we examined clinicopathological and molecular data and used mouse models. Evaluation of adrenal tumors from 118 adult patients demonstrated an increase in CTNNB1 mutations and abnormal beta-catenin accumulation in both adrenocortical adenoma and ACC. In ACC, these features were adversely associated with survival. Mice with stabilized beta-catenin exhibited a temporal progression of increased adrenocortical hyperplasia, with subsequent microscopic and macroscopic adenoma formation. Elevated Igf2 expression alone did not cause hyperplasia. With the combination of stabilized beta-catenin and elevated Igf2 expression, adrenal glands were larger, displayed earlier onset of hyperplasia, and developed more frequent macroscopic adenomas (as well as one carcinoma). Our results are consistent with a model in which dysregulation of one pathway may result in adrenal hyperplasia, but accumulation of a second or multiple alterations is necessary for tumorigenesis. (Ant J Pathol 2012, 181:1017-1033; http://dx.doi.org/10.1016/j.ajpath.2012.05.026)

A transcriptional study in mice with different ethanol-drinking profiles: Possible involvement of the GABA(B) receptor

Previous studies have suggested that gamma-aminobutyric acid-B (GABA(B)) receptor agonists effectively reduce ethanol intake. The quantification using real-time polymerase chain reaction of Gabbr1 and Gabbr2 mRNA from the prefrontal cortex, hypothalamus, hippocampus, and striatum in mice exposed to an animal model of the addiction developed in our laboratory was performed to evaluate the involvement of the GABAB receptor in ethanol consumption. We used outbred, Swiss mice exposed to a three-bottle free-choice model (water, 5% v/v ethanol, and 10% v/v ethanol) that consisted of four phases: acquisition (AC), withdrawal (W), reexposure (RE), and quinine-adulteration (AD). Based on individual ethanol intake, the mice were classified into three groups: "addicted" (A group; preference for ethanol and persistent consumption during all phases), "heavy" (H group; preference for ethanol and a reduction in ethanol intake in the AD phase compared to AC phase), and "light" (L group; preference for water during all phases). In the prefrontal cortex in the A group, we found high Gabbr1 and Gabbr2 transcription levels, with significantly higher Gabbr1 transcription levels compared with the C (ethanol-naive control mice). L, and H groups. In the hippocampus in the A group, Gabbr2 mRNA levels were significantly lower compared with the C, L, and H groups. In the striatum, we found a significant increase in Gabbr1 transcription levels compared with the C, L, and H groups. No differences in Gabbr1 or Gabbr2 transcription levels were observed in the hypothalamus among groups. In summary, Gabbr1 and Gabbr2 transcription levels were altered in cerebral areas related to drug taking only in mice behaviorally classified as "addicted" drinkers, suggesting that these genes may contribute to high and persistent ethanol consumption. (C) 2012 Elsevier Inc. All rights reserved.

Drug-targeting in combined cancer chemotherapy: tumor growth inhibition in mice by association of paclitaxel and etoposide with a cholesterol-rich nanoemulsion

Lipid nanoemulsions (LDE) may be used as carriers of paclitaxel (PTX) and etoposide (ETP) to decrease toxicity and increase the therapeutic action of those drugs. The current study investigates the combined chemotherapy with PTX and ETP associated with LDE. Four groups of 10-20 B16F10 melanoma-bearing mice were treated with LDE-PTX and LDE-ETP in combination (LDE-PTX + ETP), commercial PTX and ETP in combination (PTX + ETP), single LDE-PTX, and single LDE-ETP. PTX and ETX doses were 9 mu mol/kg administered in three intraperitoneal injections on three alternate days. In two control groups mice were treated with saline solution or LDE alone. Tumor growth, metastasis presence, cell-cycle distribution, blood cell counts and histological data were analyzed. Toxicity of all treatments was evaluated in mice without tumors. Tumor growth inhibition was similarly strong in all treatment groups. However, there was a greater reduction in the number of animals bearing metastases in the LDE-PTX + ETP group (30 %) in comparison to the PTX + ETP group (82 %, p < 0.05). Reduction of cellular density, blood vessels and increase of collagen fibers in tumor tissues were observed in the LDE-PTX + ETP group but not in the PTX + ETP group, and in both groups reduced melanoma-related anemia and thrombocytosis were observed. Flow cytometric analysis suggested that LDE-PTX + ETP exhibited greater selectivity to neoplastic cells than PTX-ETP, showing arrest (65 %) in the G(2)/M phase of the cell cycle (p < 0.001). Toxicity manifested by weight loss and myelosuppression was markedly milder in the LDE-PTX + ETP than in the PTX + ETP group. LDE-PTX + ETP combined drug-targeting therapy showed markedly superior anti-cancer properties and reduced toxicity compared to PTX + ETP.

Oral immunization with attenuated Salmonella vaccine expressing Escherichia coli O157:H7 intimin gamma triggers both systemic and mucosal humoral immunity in mice

Human infections with EHEC such as O157:H7 have been a great concern for worldwide food-industry surveillance. This pathogen is commonly associated with bloody diarrhea that can evolve to the life-threatening hemolytic uremic syndrome. Animals are the natural reservoir where this pathogen remains asymptomatically, in steps of ingestion and colonization of the bowel. The bacterium is shed in the feces, contaminating the surroundings, including water and food that are directed for human consumption. A major player in this colonization process is intimin, an outer membrane adhesion molecule encoded by the E. coli attachment and effacement (eae) gene that has been shown to be essential for intimate bacterial attachment to eukaryotic host cells. In an attempt to reduce the colonization of animal reservoirs with EHEC O157:H7, we designed a vaccine model to induce an immune response against intimin gamma. The model is based on its recombinant expression in attenuated Salmonella, used as a suitable vaccine vector because of its recognized ability to deliver recombinant antigens and to elicit all forms of immunity: mucosal, systemic, and humoral responses. To test this model, mice were orally immunized with a S. enterica serovar Typhimurium strain carrying the pYA3137eaeA vector, and challenged with E. coli O157:H7. Here we show that immunization induced the production of high levels of specific IgG and IgA antibodies and promoted reduction in the fecal shedding of EHEC after challenge. The live recombinant vaccine reported herein may contribute to the efforts of reducing animal intestinal mucosa colonization.

Phoneutria nigriventer spider toxin Tx2-6 causes priapism and death: A histopathological investigation in mice

Phoneutria nigriventer spider bite causes priapism, an effect attributed to the peptide toxins Tx2-5 and Tx2-6 and involving nitric oxide. Tx2-6 (MW = 5287) is known to delay the inactivation of Sodium channels in the same fashion as many other venom toxins. In the present study we evaluated the i.p. dose that induces priapism and the other symptoms in mice. Animals killed by the toxin or crude venom (0.85 mg/kg) were autopsied and a pathological study of brain, lung, kidney, liver and heart was undertaken using standard techniques. The same protocol was employed with animals injected with crude venom. Results showed that priapism is the first sign of intoxication, followed by piloerection, abundant salivation and tremors. An i.p. injection of about 0.3 mu g/kg induced only priapism with minimal side-effects. The most remarkable histological finding was a general vascular congestion in all organs studied. Penis showed no necrosis or damage. Lungs showed vascular congestion and alveolar hemorrhage. Heart showed also sub-endothelial hemorrhage. Brain showed only a mild edema and vascular congestion. Results obtained with crude venom closely resemble those of purified toxin. We conclude that Tx2-6 have profound effects on the vascular bed especially in lungs and heart, which may be the cause of death. Interestingly brain tissue was less affected and the observed edema may be attributed to respiratory impairment. To the best of our knowledge this is the first histopathological investigation on this toxin and venom suggesting a possible cause of death. (C) 2012 Elsevier Ltd. All rights reserved.