Relief of the pain of neuromas-in-continuity and scarred median and ulnar nerves in the distal forearm and wrist by neurolysis, wrapping in vascularized forearm fascial flaps and adjunctive procedures

This prospective study reports treatment by neurolysis then wrapping the nerves in vascularized forearm fascia and, when necessary, adjunctive procedures of twelve median and two ulnar nerves in continuity in the distal forearm with neurogenic pain. Preoperatively, all 14 patients had severe pain in at least one of the five modalities of pain analysed. There was complete resolution of all modalities of pain in eight of 14 patients following neurolysis and fascial nerve wrap surgery and two more patients had only mild pain in one or two modalities. After the addition of wrist pinning or arthrodesis alone or in conjunction with selective division of flexor tendons in four patients, there was complete resolution of all modalities of pain in nine of 14 patients. A further three patients had mild pain in three or less modalities and only one patient continued to have severe pain in one modality.

Effects of oral administration of antioxidant taurine on haematological parameters in Wistar rats

The present study evaluates the effects of oral administration of taurine on haematological parameters in normal wistar rats. Tissue oxidative stress is implicated in pathogenesis of various clinical disorders and antioxidant taurine is emerging as prophylactic and therapeutic agent. However, studies on effects of taurine on normal physiology are not reported in literature. Normal saline (Group I) or 5% taurine in normal saline was administered in dose of 50 mg (Group II), 250 mg (Group III) or 500 mg kg(-1) of b.wt. (Group IV) through intragastric intubation for 60 days. The blood cell counts, haemoglobin content, packed cell volume, blood indices, bleeding time and clotting time were estimated using routine laboratory haematological techniques. Neutrophil's phagocytic activity was determined by nitroblue tetrazolium reduction test; serum lysozyme activity was estimated colorimetrically by the degree to lyse bacterial cell suspension and serum taurine levels were estimated by HPLC fluorimetric technique. Platelet count showed a decrease in Group III and IV when compared with Group I and II (p<0.001). Mean corpuscular haemoglobin of Group III and IV are significantly lowered when compared to Group I (p<0.001). A statistically significant decrease was observed in the mean corpuscular haemoglobin concentration between Group 1 and Group IV (p<0.001). The neutrophil percentage of Group II, Group III and Group IV showed a significant increase over Group I (p<0.001). The percentage of lymphocytes showed a significant decrease in Group II, III and Group IV when compared to Group I (p<0.001). Neutrophil's phagocytic activity is significantly lowered in Group III and IV when compared to Group I (p<0.001). The serum lysozyme activity of Group III and IV showed a significant increase over Group I (at p<0.001). From the present study it may be concluded that long term oral administration of taurine affects normal haematological functions.

Cannabinoid receptor CB1-immunoreactive nerve fibres in painful and non-painful human tooth pulp

The cannabinoid receptor CB1 is involved in modulation of neuronal hypersensitivity and pain. The aim of this study was to evaluate CB1 receptor levels for the first time in dental pain. A total of 19 patients due for molar extraction were divided into two groups, those with existing dental pain (n=9), and those with no history of pain (n=10). Immunohistochemistry and computer image analysis was used to evaluate CB1-positive nerve fibres in tooth pulp, with neurofilament-immunostaining as a structural nerve marker. CB1-immunoreactive nerve fibres were scattered throughout the tooth pulp and often seen in nerve bundles, but the fibres did not penetrate the subodontoblastic layer. There was no statistically significant change in the CB1 nerve fibre percentage area in the painful group compared to the non-painful group (p=0.146); the neurofilament fibres were significantly reduced in the painful group compared to the controls (p=0.028), but there was no difference in the ratio of CB1 to neurofilaments between the two groups. Thus, CB1 expression is maintained by nerve fibres in painful human dental pulp, and peripherally-restricted CB1 agonists currently in development may advance the treatment of dental pain.

Insulinotropic effect of aqueous extract of Brassica nigra improves glucose homeostasis in streptozotocin induced diabetic rats

Aqueous extract of BRASSICA NIGRA (AEBN) has been shown to have good antidiabetic effect along with significant decrease (p<0.01) of abnormal serum lipid levels in our previous study. To understand the mechanism of action, effect of oral administration of AEBN for two months on glycolytic and gluconeogenic enzymes was studied in liver and kidney tissues of rats with streptozotocin (STZ) induced diabetes mellitus. The activities of gluconeogenic enzymes were higher and of glycolytic enzymes were decreased in both the liver and kidney tissues during diabetes. However, in diabetic rats treated with AEBN for two months, decrease of serum glucose, increase of serum insulin and release of insulin from pancreas (shown in vitro from isolated pancreas) along with the restoration of key regulatory enzyme activities of carbohydrate metabolism and glycogen content were observed. The therapeutic role of AEBN in STZ induced diabetes as exemplified in this study can be attributed to the release of insulin from pancreas and change of glucose metabolizing enzyme activities to normal levels, thus stabilizing glucose homeostasis in the liver and kidney. The LD50 was found to be more than 15 times the effective dose (ED) implying higher margin of safety for AEBN. These biochemical effects indicate that AEBN could be a possible new therapeutic agent for the treatment of diabetes.

Increased capsaicin receptor TRPV1-expressing sensory fibres in irritable bowel syndrome and their correlation with abdominal pain

OBJECTIVE

The capsaicin receptor TRPV1 (transient receptor potential vanilloid type-1) may play an important role in visceral pain and hypersensitivity states. In irritable bowel syndrome (IBS), abdominal pain is a common and distressing symptom where the pathophysiology is still not clearly defined. TRPV1-immunoreactive nerve fibres were investigated in colonic biopsies from patients with IBS, and this was related to abdominal pain.

METHODS

Rectosigmoid biopsies were collected from 23 IBS patients fulfilling Rome II criteria, and from 22 controls. Abdominal pain scores were recorded using a validated questionnaire. TRPV1-, substance P- and neuronal marker protein gene product (PGP) 9.5-expressing nerve fibres, mast cells (c-kit) and lymphocytes (CD3 and CD4) were quantified, following immunohistochemistry with specific antibodies. The biopsy findings were related to the abdominal pain scores.

RESULTS

A significant 3.5-fold increase in median numbers of TRPV1-immunoreactive fibres was found in biopsies from IBS patients compared with controls (p<0.0001). Substance P-immunoreactive fibres (p = 0.01), total nerve fibres (PGP9.5) (p = 0.002), mast cells (c-kit) (p = 0.02) and lymphocytes (CD3) (p = 0.03) were also significantly increased in the IBS group. In multivariate regression analysis, only TRPV1-immuno-reactive fibres (p = 0.005) and mast cells (p = 0.008) were significantly related to the abdominal pain score.

CONCLUSIONS

Increased TRPV1 nerve fibres are observed in IBS, together with a low-grade inflammatory response. The increased TRPV1 nerve fibres may contribute to visceral hypersensitivity and pain in IBS, and provide a novel therapeutic target.

TRPA1 receptor localisation in the human peripheral nervous system and functional studies in cultured human and rat sensory neurons

TRPA1 is a receptor expressed by sensory neurons, that is activated by low temperature (<17 degrees C) and plant derivatives such as cinnamaldehyde and isoeugenol, to elicit sensations including pain. Using immunohistochemistry, we have, for the first time, localised TRPA1 in human DRG neurons, spinal cord motoneurones and nerve roots, peripheral nerves, intestinal myenteric plexus neurones, and skin basal keratinocytes. TRPA1 co-localised with a subset of hDRG neurons positive for TRPV1, the heat and capsaicin receptor. The number of small/medium TRPA1 positive neurons (< or =50 microm) was increased after hDRG avulsion injury [percentage of cells, median (range): controls 16.5 (7-23); injured 46 (34-55); P<0.005], but the number of large TRPA1 neurons was unchanged [control 19.5 (13-31); injured 21 (11-35)]. Similar TRPA1 changes were observed in cultured hDRG neurons, after exposure to a combination of key neurotrophic factors NGF, GDNF and NT-3 (NTFs) in vitro. We used calcium imaging to examine responses of HEK cells transfected with hTRPA1 cDNA, and of human and rat DRG neurons cultured with or without added NTFs, to cinnamaldehyde (CA) and isoeugenol (IE). Exposure to NTFs in vitro sensitized cultured human sensory neuronal responses to CA; repeated CA exposure produced desensitisation. In rDRG neurons, low (225 microM) CA preincubation enhanced capsaicin responses, while high (450 microM and 2mM) CA caused inhibition which was partially reversed in the presence of 8 bromo cAMP, indicating receptor dephosphorylation. While TRPA1 localisation is more widespread than TRPV1, it represents a promising novel drug target for the treatment of chronic pain and hypersensitivity.

Normalization of substance P levels in rectal mucosa of patients with faecal incontinence treated successfully by sacral nerve stimulation

Background

Sacral nerve stimulation (SNS) may improve faecal incontinence by modulating rectal sensation. This study measured changes in the peripheral expression of various neural epitopes in response to SNS.

Methods

Rectal mucosal biopsies were taken from 12 patients before and after temporary SNS, and from ten responders at 90 days after permanent stimulation. Sections were immunostained for substance P, transient receptor potential vanilloid (TRPV) 1, vasoactive intestinal peptide (VIP) and calcitonin gene-related peptide (CGRP). Levels were compared with those in nine continent controls.

Results

Baseline levels of percentage area immunoreactivities of substance P (median 0·51 (95 per cent confidence interval 0·31 to 0·73) versus 0·13 (0·07 to 0·27) per cent; P &lt; 0·001) and TRPV1 (0·76 (0·41 to 1·11) versus 0·09 (0·04 to 0·14) per cent; P &lt; 0·001), but not of VIP (1·26 (0·37 to 2·15) versus 1·28 (0·39 to 2·17); P = 0·943), were significantly greater than in controls. Successful SNS resulted in a significant decrease in substance P immunostaining after temporary (0·15 (0·06 to 0·51) per cent; P = 0·051) and permanent (0·17 (0 to 0·46) per cent; P = 0·051) stimulation. Immunoreactivity of TRPV1, VIP, CGRP and neural markers showed no qualitative change.

Conclusion

Patients with faecal incontinence demonstrate normalization of raised rectal mucosal substance P levels following successful SNS.

Long-term effects of Terminalia chebula Retz. on hyperglycemia and associated hyperlipidemia, tissue glycogen content and in vitro release of insulin in streptozotocin induced diabetic rats

The aqueous extract of the fruits of Terminalia chebula Retz. has been evaluated for its antidiabetic activity in streptozotocin (STZ) induced mild diabetic rats and compared with a known drug, tolbutamide. The oral effective dose (ED) of the extract was observed to be 200 mg/kg body weight, which produced a fall of 55.6% (p<0.01) in the oral glucose tolerance test. Oral administration of ED of aqueous extract of T.chebula (AETC) daily once for two months reduced the elevated blood glucose by 43.2% (p<0.01) and significantly reduced the increase in glycosylated hemoglobin (HbA1c) (p<0.01). The same dose also showed a marked improvement in controlling the elevated blood lipids as well as decreased serum insulin levels in contrast to the untreated diabetic animals. Hepatic and skeletal muscle glycogen content decreased by 75% and 62.9% respectively in diabetic controls, these alterations were partly prevented (34.9% and 21.17%) in AETC treated group when compared to the healthy controls. The in vitro studies with pancreatic islets showed that the insulin release was nearly two times more than that in untreated diabetic animals. The treatment did not have any unfavorable effect on other blood parameters of liver and kidney function tests. LD 50 was found to be above 3 g/kg bw i.e. 15 times of ED, because there were no deaths of animals even at this dose indicating high margin of safety. These findings suggest further investigations for the possible use of the aqueous extract of fruits of T.chebula for the treatment of diabetes.

A hyperspectral fluorescence lifetime probe for skin cancer diagnosis

The autofluorescence of biological tissue can be exploited for the detection and diagnosis of disease but, to date, its complex nature and relatively weak signal levels have impeded its widespread application in biology and medicine. We present here a portable instrument designed for the in situ simultaneous measurement of autofluorescence emission spectra and temporal decay profiles, permitting the analysis of complex fluorescence signals. This hyperspectral fluorescence lifetime probe utilizes two ultrafast lasers operating at 355 and 440 nm that can excite autofluorescence from many different biomolecules present in skin tissue including keratin, collagen, nicotinamide adenine dinucleotide (phosphate), and flavins. The instrument incorporates an optical fiber probe to provide sample illumination and fluorescence collection over a millimeter-sized area. We present a description of the system, including spectral and temporal characterizations, and report the preliminary application of this instrument to a study of recently resected (<2 h) ex vivo skin lesions, illustrating its potential for skin cancer detection and diagnosis.

Multifocal multiphoton excitation and time correlated single photon counting detection for 3-D fluorescence lifetime imaging

We report a multifocal multiphoton time-correlated single photon counting (TCSPC) fluorescence lifetime imaging (FLIM) microscope system that uses a 16 channel multi-anode PMT detector. Multiphoton excitation minimizes out-of-focus photobleaching, multifocal excitation reduces non-linear in-plane photobleaching effects and TCSPC electronics provide photon-efficient detection of the fluorescence decay profile. TCSPC detection is less prone to bleaching- and movement-induced artefacts compared to wide-field time-gated or frequency-domain FLIM. This microscope is therefore capable of acquiring 3-D FLIM images at significantly increased speeds compared to single beam multiphoton microscopy and we demonstrate this with live cells expressing a GFP tagged protein. We also apply this system to time-lapse FLIM of NAD(P)H autofluorescence in single live cells and report measurements on the change in the fluorescence decay profile following the application of a known metabolic inhibitor.

Burning mouth syndrome as a trigeminal small fibre neuropathy: Increased heat and capsaicin receptor TRPV1 in nerve fibres correlates with pain score

Burning mouth syndrome (BMS) is often an idiopathic chronic and intractable pain condition, affecting 1.5-5.5% of middle-aged and elderly women. We have studied the heat and capsaicin receptor TRPV1, and its regulator nerve growth factor (NGF), in BMS. Patients with BMS (n=10) and controls (n=10) were assessed for baseline and post-topical capsaicin pain scores, and their tongue biopsies immunostained for TRPV1, NGF, and structural nerve markers neurofilament and peripherin. Nerve fibres penetrating the epithelium were less abundant in BMS (p<0.0001), indicating a small fibre neuropathy. TRPV1-positive fibres were overall significantly increased in BMS (p=0.0011), as were NGF fibres (p<0.0001) and basal epithelial cell NGF staining (p<0.0147). There was a significant correlation between the baseline pain score and TRPV1 (p=0.0143) and NGF fibres (p=0.0252). A significant correlation was observed between baseline and post-capsaicin pain (p=0.0006). Selective TRPV1 and NGF blockers may provide a new therapy for BMS.

Motor recovery and the breathing arm after brachial plexus surgical repairs, including re-implantation of avulsed spinal roots into the spinal cord

Forty-four patients with severe traction brachial plexus avulsion injuries were studied following surgical repairs. In eight patients, re-implanting avulsed spinal roots directly to the spinal cord was performed with other repairs and motor recovery in the proximal limb was similar to that achieved by conventional nerve grafts and transfers when assessed using the MRC clinical grades, Narakas scores, EMG and Transcranial Magnetic Stimulation (TMS). Thirty-four of the 37 patients had co-contractions of agonist and antagonist muscle groups. Spontaneous contractions of limb muscles in synchrony with respiration, the "breathing arm", were noted in 26 of 37 patients: in three patients, the source of the breathing arm was from spinal cord re-connection, providing evidence of regeneration from the CNS to the periphery. Our study shows that re-connection of avulsed spinal roots can produce good motor recovery and provides a clinical model for developing new treatments which may enhance nerve regeneration.

Relocation of painful end neuromas and scarred nerves from the zone II territory of the hand

This paper reports the results of treatment by proximal relocation of 46 painful end-neuromas or scarred nerves in 33 patients from the pre-defined Zone II of the hand. The relocated nerves included four palmar cutaneous branches of the median nerve, 17 dorsal branches of the ulnar nerves and 25 digital nerves. If no pain at the original site and no pain or only mild pain at the relocation site are considered an adequate treatment of these difficult problems, these relocation procedures achieve complete control of spontaneous baseline pain, complete control of spontaneous spikes of pain, 93% control of direct pressure pain, complete control of movement pain (excluding the extremes of movement of the wrist into extension, supination and, less frequently, pronation) and 96% control of hypersensitivity of the overlying skin.

Peripheral and central mechanisms of visceral sensitization in man

Visceral hypersensitivity (perception of gastrointestinal sensory events at a lower-than-normal threshold) is considered to be an important pathophysiological mechanism in the development of functional gastrointestinal disorders (FGIDs), such as irritable bowel syndrome, non-cardiac chest pain and functional dyspepsia. These disorders are associated with significant health care and socioeconomic costs due to factors such as repeated visits to consultants, hospitalizations and work absenteeism. Despite the presence of extensive evidence linking visceral hypersensitivity and FGIDs, the mechanism(s) underlying visceral hypersensitivity has not been fully elucidated. Suggested hypotheses include sensitization of afferent neurones, both at the level of the enteric and the (afferent) autonomic nervous system (peripheral sensitization), sensitization of spinal cord dorsal horn neurones (central sensitization) and psychosocial factors/psychiatric comorbidity influencing the processing of afferent signals at the level of the brain. Importantly, these hypotheses may be complementary rather than mutually exclusive. However, the degree to which each of these mechanisms contributes to the overall perception of visceral pain, and therefore the generation of symptoms, still remains unclear. This article discusses the mechanisms that may underlie visceral hypersensitivity, with reference to FGIDs. Understanding these mechanisms is essential in order to improve the diagnosis and treatment of patients with these disorders.