Differential regulation of FGF-2 in neurons and reactive astrocytes of axotomized rat hypoglossal nucleus. A possible therapeutic target for neuroprotection in peripheral nerve pathology

Despite the favorable treatment of cranial nerve neuropathology in adulthood, some cases are resistant to therapy leading to permanent functional impairments In many cases, suitable treatment is problematic as the therapeutic target remains unknown Basic fibroblast growth factor (bFGF, FGF 2) is involved in neuronal maintenance and wound repair following nervous system lesions It is one of few neurotrophic molecules acting in autocrine, paracrine and intracrine fashions depending upon specific circumstances Peripheral cranial somatic motor neurons, i e hypoglossal (XII) neurons, may offer a unique opportunity to study cellular FGF 2 mechanisms as the molecule is present in the cytoplasm of neurons and in the nuclei of astrocytes of the central nervous system FGF-2 may trigger differential actions during development, maintenance and lesion of XII neurons because axotomy of those cells leads to cell death during neonatal ages, but not in adult life Moreover, the modulatory effects of astroglial FGF 2 and the Ca+2 binding protein S100 beta have been postulated in paracrine mechanisms after neuronal lesions In our study, adult Wistar rats received a unilateral crush or transection (with amputation of stumps) of XII nerve, and were sacrificed after 72 h or 11 days Brains were processed for immunohistochemical localization of neurofilaments (NF), with or without counterstaining for Nissl substance, ghat fibrillary acidic protein (GFAP, as a marker of astrocytes), S100 beta and FGF-2 The number of Nissl positive neurons of axotomized XII nucleus did not differ from controls The NF immunoreactivity increased in the perikarya and decreased in the neuropil of axotomized XII neurons 11 days after nerve crush or transection An astrocytic reaction was seen in the ipsilateral XII nucleus of the crushed or transected animals 72 h and 11 days after the surgery The nerve lesions did not change the number of FGF-2 neurons in the ipsilateral XII nucleus, however, the nerve transection increased the number of FGF-2 ghat profiles by 72 h and 11 days Microdensitometric image analysis revealed a short lasting decrease in the intensity of FGF 2 immunoreactivity in axotomized XII neurons by 72 h after nerve crush or transection and also an elevation of FGF-2 in the ipsilateral of ghat nuclei by 72h and 11 days after the two lesions S100 beta decreased in astrocytes of 11-day transected XII nucleus The two-color immunoperoxidase for the simultaneous detection of the GFAP/FGF-2 indicated FGF-2 upregulation in the nuclei of reactive astrocytes of the lesioned XII nucleus Astroglial FGF-2 may exert paracrine trophic actions in mature axotomized XII neurons and might represent a therapeutic target for neuroprotection in peripheral nerve pathology (C) 2009 Elsevier GmbH All rights reserved

Role of spinal microglia in myositis-induced central sensitisation: An immunohistochemical and behavioural study in rats

There is increasing evidence that spinal glial cells play an important role in chronic pain states. However, so far no data on the role of microglia in muscle pain are available. The aim of the present study was to investigate the involvement of spinal microglial cells in chronic muscle pain. In a rat model of chronic muscle inflammation (injection of complete Freunds adjuvant into the gastrocnemius-soleus muscle) alterations of microglia were visualized with quantitative OX-42 immunohistochemistry in the dorsal horn of the segments L4 and L5 12 days after induction of inflammation. In behavioural experiments the influence of chronic intrathecally applied minocycline - a specific microglia inhibitor - or an antibody against tumour necrosis factor-alpha (TNF-alpha: a cytokine released from microglia) on pain-related behaviour was investigated after 1, 3, 6, and 12 days. The immunhistochemical data show that in the deep laminae of the spinal dorsal horn microglial cells reacted with morphological changes to the muscle inflammation. Following inflammation, the mean boundary length surrounding the OX-42 immunostained area was significantly shorter. This indicates that microglial cells were activated by the myositis and withdrew their processes. Chronic intrathecal administration of minocycline or anti TNF-alpha with an osmotic mini-pump largely normalised the inflammation-induced changes in spontaneous exploratory behaviour and attenuated the hypersensitivity to mechanical stimulation. Both the immunohistochemical and behavioural data show that spinal microglial cells are involved in nociceptive processes in the cause of a chronic muscle inflammation. (C) 2008 European Federation of International Association for the Study of Pain Chapters. Published by Elsevier Ltd. All rights reserved.

Crotalphine induces potent antinociception in neuropathic pain by acting at peripheral opioid receptors

Neuropathic pain is an important clinical problem and it is usually resistant to the current therapy. We have recently characterized a novel analgesic peptide, crotalphine, from the venom of the South American rattlesnake Crotalus durissus terrificus. In the present work, the antinociceptive effect of crotalphine was evaluated in an experimental model of neuropathic pain induced in rats by chronic constriction, of sciatic nerve. The effect of the peptide was compared to that induced by the crude venom, which confirmed that crotalphine is responsible for the antinociceptive effect of the crotalid venom on neuropathic pain. For characterization of neuropathic pain, the presence of hyperalgesia, allodynia and spontaneous pain was assessed at different times after nerve constriction. These phenomena were detected 24 h after surgery and persisted at least for 14 days. The pharmacological treatments were performed on day 14 after surgery. Crotalphine (0.2-5 mu g/kg) and the crude venom (400-1600 mu g/kg) administered p.o. inhibited hyperalgesia, allodynia and spontaneous pain induced by nerve constriction. The antinociceptive effect of the peptide and crude venom was long lasting, since it was detected up to 3 days after treatment. Intraplantar injection of naloxone (1 mu g/paw) blocked the antinociceptive effect, indicating the involvement of opioid receptors in this phenomenon. Gabapentin (200 mg/kg, p.o.), and morphine (5 mg/kg, s.c.), used as positive controls, blocked hyperalgesia and partially inhibited allodynia induced by nerve constriction. These data indicate that crotalphine induces a potent and long lasting opioid antinociceptive effect in neuropathic pain that surpasses that observed with standard analgesic drugs. (C) 2008 Elsevier B.V. All rights reserved.

TRPV1 receptors are involved in protein nitration and Muller cell reaction in the acutely axotomized rat retina

We report here the protein expression of TRPV1 receptor in axotomized rat retinas and its possible participation in mechanisms involved in retinal ganglion cell (RGC) death. Adult rats were subjected to unilateral, intraorbital axotomy of the optic nerve, and the retinal tissue was removed for further processing. TRPV1 total protein expression decreased progressively after optic nerve transection, reaching 66.2% of control values 21 days after axotomy. The number of cells labeled for TRPV1 in the remnant GCL decreased after 21 days post-lesion (to 63%). Fluoro-jade B staining demonstrated that the activation of TRPV1 in acutely-lesioned eyes elicited more intense neuronal degeneration in the GCL and in the inner nuclear layer than in sham-operated retinas. A single intraocular injection of capsazepine (100 mu M), a TRPV1 antagonist, 5 days after optic nerve lesion, decreased the number of GFAP-expressing Muller cells (72.5% of control values) and also decreased protein nitration in the retinal vitreal margin (75.7% of control values), but did not affect lipid peroxidation. Furthermore, retinal explants were treated with capsaicin (100 mu M), and remarkable protein nitration was then present, which was reduced by blockers of the constitutive and inducible nitric oxide synthases (7-NI and aminoguanidine, respectively). TRPV1 activation also increased GFAP expression, which was reverted by both TRPV1 antagonism with capsazepine and by 7-NI and aminoguanidine. Given that Muller cells do not express TRPV1, we suppose that the increased GFAP expression in these cells might be elicited by TRPV1 activation and by its indirect effect upon nitric oxide overproduction and peroxynitrite formation. We incubated Fluorogold pre-labeled retinal explants in the presence of capsazepine (1 mu M) during 48 h. The numbers of surviving RGCs stained with fluorogold and the numbers of apoptotic cells in the GCL detected with TUNEL were similar in lesioned and control retinas. We conclude that TRPV1 receptor expression decreased after optic nerve injury due to death of TRPV1-containing cells. Furthermore, these data indicate that TRPV1 might be involved in intrinsic protein nitration and Muller cell reaction observed after optic nerve injury. (C) 2010 Elsevier Ltd. All rights reserved.

Effects of hyperbaric oxygen therapy on facial nerve regeneration

Conclusion. Hyperbaric oxygen treatment (HBOT) promoted an increase of the mean axonal diameter in the group evaluated 2 weeks after lesion induction, which suggests a more advanced regeneration process. However, the number of myelin nerve fibers of the facial nerve of the rabbits was similar when compared to the control and treatment groups, in both evaluation periods. Objective. To evaluate the effect of HBOT on the histological pattern of the facial nerve in rabbits exposed to a nerve crush injury. Materials and methods. Twenty rabbits were exposed to facial nerve crush injury. Ten rabbits received HBOT, 10 rabbits comprised the control group. The rabbits were sacrificed 2 and 4 weeks after the trauma. Qualitative morphological analysis, measurement of the external axonal diameters and myelin fiber count were carried out in an area of 185 000 mu m(2). Results. There was an increase in the area of the axons and thicker myelin in the 2 weeks treatment group in comparison with the control group. The mean diameter of the axons was of 2.34 mu m in the control group and of 2.81 mu m in the HBOT group, with statistically significant differences. The 2 week control group had a mean number of myelin fibers of 186 +/- 5.2664, and the HBOT group had a mean number of 2026.3 +/- 302; this was not statistically significant. The 4 week control group presented a mean of 2495.1 +/- 479 fibers and the HBOT group presented a mean of 2359.9 +/- 473; this was not statistically significant.

Ablation of primary afferent neurons by neonatal capsaicin treatment reduces the susceptibility of the portal hypertensive gastric mucosa to ethanol-induced injury in cirrhotic rats

Primary sensory afferent neurons modulate the hyperdynamic circulation in Cirrhotic rats with portal hypertension.The stomach of cirrhotic rats is prone to damage induced by ethanol, a phenomenon associated with reduced gastric hyperemic response to acid-back diffusion. The aim of this study was to examine the impact of ablation of capsaicin-sensitive neurons and the tachykinin NK(1) receptor antagonist A5330 on the susceptibility of the portal hypertensive gastric mucosa, to ethanol-induced injury and its effects on gastric cyclooxygenase (COX) and nitric oxide synthase (NOS) mRNA expression. Capsaicin was administered to neonatal, male, Wistar rats and the animals were allowed to grow. Cirrhosis was then induced by bile duct ligation in adult rats while controls had sham operation. Ethanol-induced gastric damage was assessed using ex vivo gastric chamber experiments. Gastric blood flow was measured as well as COX/NOS mRNA expression. Topical application of ethanol produced significant gastric damage in cirrhotic rats compared to controls, which was reversed in capsaicin- and A5330-treated animals. Mean arterial and portal pressure was normalized in capsaicin-treated cirrhotic rats. Capsaicin and A5330 administration restored gastric blood flow responses to topical application of ethanol followed by acid in cirrhotic rats. Differential COX and NOS mRNA expression was noted in bile duct ligated rats relative to controls. Capsaicin treatment significantly modified gastric eNOS/iNOS/COX-2 mRNA expression in cirrhotic rats. Capsaicin-sensitive neurons modulate the susceptibility of the portal hypertensive gastric mucosa to injury induced by ethanol via tachykinin NK(1) receptors and signalling of prostaglandin and NO production/release. (c) 2008 Elsevier B.V. All rights reserved.

Sympathetic nerve activity is decreased during device-guided slow breathing

It is known that slow breathing (<10 breaths min(-1)) reduces blood pressure ( BP), but the mechanisms involved in this phenomenon are not completely clear. The aim of this study was to evaluate the acute responses of the muscle sympathetic nerve activity, BP and heart rate (HR), using device-guided slow breathing ( breathe with interactive music (BIM)) or calm music. In all, 27 treated mild hypertensives were enrolled. Muscle sympathetic nerve activity, BP and HR were measured for 5min before the use of the device (n=14) or while subjects listened to calm music (n=13), it was measured again for 15 min while in use and finally, 5min after the interventions. BIM device reduced respiratory rate from 16 +/- 3 beats per minute (b.p.m) to 5.5 +/- 1.8 b.p.m (P<0.05), calm music did not affect this variable. Both interventions reduced systolic (-6 and -4mmHg for both) and diastolic BPs (-4mmHg and -3mmHg, respectively) and did not affect the HR (-1 and -2 b.p.m respectively). Only the BIM device reduced the sympathetic nerve activity of the sample (-8bursts min(-1)). In conclusion, both device-guided slow breathing and listening to calm music have decreased BP but only the device-guided slow breathing was able to reduce the peripheral sympathetic nerve activity. Hypertension Research ( 2010) 33, 708-712; doi: 10.1038/hr.2010.74; published online 3 June 2010

Intratemporal facial nerve ultrastructure in patients with idiopathic facial paralysis. Viral infection evidence study

The etiology of idiopathic peripheral facial palsy (IPFP) is still uncertain; however, some authors suggest the possibility of a viral infection. Aim: to analyze the ultrastructure of the facial nerve seeking viral evidences that might provide etiological data. Material and Methods: We studied 20 patients with peripheral facial palsy (PFP), with moderate to severe FP, of both genders, between 18-60 years of age, from the Clinic of Facial Nerve Disorders. The patients were broken down into two groups - Study: eleven patients with IPFP and Control: nine patients with trauma or tumor-related PFP. The fragments were obtained from the facial nerve sheath or from fragments of its stumps - which would be discarded or sent to pathology exam during the facial nerve repair surgery. The removed tissue was fixed in 2% glutaraldehyde, and studied under Electronic Transmission Microscopy. Results: In the study group we observed an intense repair cellular activity by increased collagen fibers, fibroblasts containing developed organelles, free of viral particles. In the control group this repair activity was not evident, but no viral particles were observed. Conclusion: There were no viral particles, and there were evidences of intense activity of repair or viral infection.

N-acetylcysteine protects against renal injury following bilateral ureteral obstruction

Background. Obstructive nephropathy decreases renal blood flow (RBF) and glomerular filtration rate (GFR), causing tubular abnormalities, such as urinary concentrating defect, as well as increasing oxidative stress. This study aimed to evaluate the effects of N-acetylcysteine (NAC) on renal function, as well as on the protein expression of aquaporin 2 (AQP2) and endothelial nitric oxide synthase (eNOS), after the relief of bilateral ureteral obstruction (BUO). Methods. Adult male Wistar rats were divided into four groups: sham (sham operated); sham operated + 440 mg/kg body weight (BW) of NAC daily in drinking water, started 2 days before and maintained until 48 h after the surgery; BUO (24-h BUO only); BUO + NAC-pre (24-h BUO plus 440 mg/kg BW of NAC daily in drinking water started 2 days before BUO); and BUO + NAC-post (24-h BUO plus 440 mg/kg BW of NAC daily in drinking water started on the day of BUO relief). Experiments were conducted 48 h after BUO relief. Results. Serum levels of thiobarbituric reactive substances, which are markers of lipid peroxidation, were significantly lower in NAC-treated rats than in the BUO group rats. The administration of NAC provided significant protection against post-BUO GFR drops and reductions in RBF. Renal cortices and BUO rats presented decreased eNOS protein expression of eNOS in the renal cortex of BUO group rats, whereas it was partially recovered in BUO + NAC-pre group rats. Urine osmolality was significantly lower in BUO rats than in sham group rats or NAC-treated rats, the last also presenting less interstitial fibrosis. Post-BUO downregulation of AQP2 protein expression was averted in the BUO + NAC-pre group rats. Conclusions. This study demonstrates that NAC administration ameliorates the renal function impairment observed 48 h after the relief of 24-h BUO. Oxidative stress is important for the suppression of GFR, RBF, tissue AQP2 and eNOS in the polyuric phase after the release of BUO.

Characteristics of Acute Kidney Injury in Patients Infected with the 2009 Influenza A (H1N1) Virus

Background and objectives: There have been few studies investigating acute kidney injury (AKI) in patients infected with the 2009 pandemic influenza A (H1N1) virus. Therefore, the objective of this study was to identify the factors associated with AKI in H1N1-infected patients. Design, setting, participants, & measurements: This was a study of 47 consecutive critically ill adult patients with reverse transcriptase-PCR-confirmed H1N1 infection in Brazil. Outcome measures were AKI (as defined by the Risk, Injury, Failure, Loss, and End-stage renal failure [RIFLE] criteria) and in-hospital death. Results: AKI was identified in 25 (53%) of the 47 H1N1-infected patients. AKI was associated with vasopressor use, mechanical ventilation, high Acute Physiology and Chronic Health Evaluation II (APACHE II) scores, and severe acidosis as well as with higher levels of C-reactive protein and lactic dehydrogenase upon intensive care unit (ICU) admission. A nephrology consultation was requested for 16 patients (64%), and 8 (50%) required dialysis. At ICU admission, 7 (15%) of the 25 AKI patients had not yet progressed to AKI. However, by 72 hours after ICU admission, no difference in RIFLE score was found between AKI survivors and nonsurvivors. Of the 47 patients, 9 (19%) died, all with AKI. Mortality was associated with mechanical ventilation, vasopressor use, dialysis, high APACHE II score, high bilirubin levels, and a low RIFLE score at ICU admission. Conclusions: Among critically ill H1N1-infected patients, the incidence of AKI is high. In such patients, AKI is mainly attributable to shock. Clin J Am Soc Nephrol 5: 1916-1921, 2010. doi: 10.2215/CJN.00840110

Tibouchina pulchra (Cham.) Cogn., a native Atlantic Forest species, as a bio-indicator of ozone: Visible injury

Tibouchina pulchra saplings were exposed to carbon filtered air (CF), ambient non-filtered air (NF) and ambient non-filtered air + 40 ppb ozone (NF + O-3) 8 h per day during two months. The AOT40 values at the end of the experiment were 48, 910 and 12,895 ppb h(-1), respectively, for the three treatments. After 25 days of exposure (AOT40=3871 ppb h(-1)), interveinal red stippling appeared in plants in the NF + O-3 chamber. In the NF chamber, symptoms were observed only after 60 days of exposure (AOT40 = 910 ppb h(-1)). After 60 days, injured leaves per plant corresponded to 19% in NF + O-3 and 1% in the NF treatment; and the average leaf area injured was 7% within the NF + O-3 and 0.2% within the NF treatment. The extent of leaf area injured (leaf injury index) was mostly explained by the accumulated exposure of ozone (r(2) = 0.89; p < 0.05). (C) 2007 Elsevier Ltd. All rights reserved.

East-West cranial differentiation in pre-Columbian populations from Central and North America

In a recent study we found that crania from South Amerindian populations on each side of the Andes differ significantly in terms of craniofacial shape. Western populations formed one morphological group, distributed continuously over 14,000 km from the Fuegian archipelago (southern Chile) to the Zulia region (northwestern Venezuela). Easterners formed another group, distributed from the Atlantic Coast up to the eastern foothills of the Andes. This differentiation is further supported by several genetic studies, and indirectly by ecological and archaeological studies. Some authors suggest that this dual biological pattern is consistent with differential rates of gene flow and genetic drift operating on both sides of the Cordillera due to historical reasons. Here we show that such East-West patterning is also observable in North America. We suggest that the ""ecological zones model"" proposed by Dixon, explaining the spread of the early Americans along a Pacific dispersal corridor, combined with the evolution of different population dynamics in both regions, is the most parsimonious mechanism to explain the observed patterns of within- and between-group craniofacial variability. (c) 2007 Elsevier Ltd. All rights reserved.

Comparative Cranial Osteology of Fossorial Lizards From the Tribe Gymnophthalmini (Squamata, Gymnophthalmidae)

Squamates (lizards, snakes and amphisbaenians) are represented by a large number of species distributed among a wide variety of habitats. Changes in body plan related to a fossorial habit are a frequent trend within the group and many morphological adaptations to this particular lifestyle evolved convergently in nonrelated species, reflecting adaptations to a similar habitat. The fossorial lifestyle requires an optimal morphological organization for an effective use of the available resources. Skeleton arrangement in fossorial squamates reflects adaptations to the burrowing activity, and different degrees of fossoriality can be inferred through an analysis of skull morphology. Here, we provide a detailed description of the skull morphology of three fossorial gymnophthalmid species: Calyptommatus nicterus, Scriptosaura catimbau, and Nothobachia ablephara. J. Morphol. 271: 1352-1365, 2010. (C) 2010 Wiley-Liss, Inc.

Structural changes in the epithelium of the small intestine and immune cell infiltration of enteric ganglia following acute mucosal damage and local inflammation

An acute enteritis is commonly followed by intestinal neuromuscular dysfunction, including prolonged hyperexcitability of enteric neurons. Such motility disorders are associated with maintained increases in immune cells adjacent to enteric ganglia and in the mucosa. However, whether the commonly used animal model, trinitrobenzene sulphonate (TNBS)-induced enteritis, causes histological and immune cell changes similar to human enteric neuropathies is not clear. We have made a detailed study of the mucosal damage and repair and immune cell invasion following intralumenal administration of TNBS. Intestines from untreated, sham-operated and TNBS-treated animals were examined at 3 h to 56 days. At 3 h, the mucosal surface was completely ablated, by 6 h an epithelial covering was substantially restored and by 1 day there was full re-epithelialisation. The lumenal epithelium developed from a squamous cell covering to a fully differentiated columnar epithelium with mature villi at about 7 days. Prominent phagocytic activity of enterocytes occurred at 1-7 days. A surge of eosinophils and T lymphocytes associated with the enteric nerve ganglia occurred at 3 h to 3 days. However, elevated immune cell numbers occurred in the lamina propria of the mucosa until 56 days, when eosinophils were still three times normal. We conclude that the disruption of the mucosal surface that causes TNBS-induced ileitis is brief, a little more than 6 h, and causes a transient immune cell surge adjacent to enteric ganglia. This is much briefer than the enteric neuropathy that ensues. Ongoing mucosal inflammatory reaction may contribute to the persistence of enteric neuropathy.

A light and scanning electron microscopy study of bone healing following inferior alveolar nerve lateralization: An experimental study in rabbits

Purpose: The purpose of this study was to evaluate the bone healing kinetics around commercially pure titanium implants following inferior alveolar nerve (IAN) lateralization in a rabbit model. Materials and Methods: Inferior alveolar nerve lateralization was performed in 16 adult female rabbits (Oryctolagus cuniculus). During the nerve lateralization procedure, 1 implant was placed through the mandibular canal, and the IAN was replaced in direct contact with the implant. During the 8-week healing period, various bone labels were administered for fluorescent microscopy analysis. The animals were euthanized by anesthesia overdose, and the mandibular blocks were exposed by sharp dissection. Nondecalcified samples were prepared for optical light and scanning electron microscopy (SEM) evaluation. Results: SEM evaluation showed bone modeling/remodeling between the IAN and implant surface. Fluorochrome area fraction labeling at different times during the healing period showed that bone apposition mainly occurred during the first 2 weeks after implantation. Conclusions: The results obtained showed that bone healing/deposition occurred between the alveolar nerves in contact with a commercially pure titanium implant. No interaction between the nerve and the implant was detected after the 8-week healing period. Appositional bone healing occurred around the nerve bundle structure, restoring the mandibular canal integrity and morphology.