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.     

Assessment of cutaneous sensory and autonomic axon reflexes in rheumatoid arthritis.

OBJECTIVE--To assess sensory function in skin overlying the joints of patients with rheumatoid arthritis, in relation to the pain and tenderness which commonly arises in structures not directly involved in the inflammatory process. METHODS--An intradermal injection of capsaicin 0.05 microgram in 10 microliters was made over the wrists and forearms of 40 patients with rheumatoid arthritis and 46 control subjects. Axon reflex vasodilatation was measured using laser Doppler flowmetry. Cholinergic sympathetic function was assessed by measuring axon reflex sweating induced by a single intradermal injection of nicotine 0.5 microgram in 0.1 ml. RESULTS--Capsaicin induced axon reflex vasodilation over the wrists was found to decrease with age in normal subjects (r = -0.62, p < 0.001). In patients with rheumatoid arthritis, capsaicin induced axon reflex vasodilatation was significantly greater over the wrists, but not the forearms, when compared with age matched normal controls (p < 0.01). A minimal correlation between axon reflex vasodilatation and visual analogue pain score was apparent in the rheumatoid group (r = -0.37, p < 0.05). Nicotine induced sweating responses were similar in the rheumatoid and normal groups, and both showed a linear age related decline. CONCLUSIONS--The results show a selective increase of capsaicin induced vasodilatation in skin overlying joints in patients with rheumatoid arthritis. This suggests that the activity of a sub-population of periarticular small sensory fibres is altered, which may explain, at least in part, some of the clinical findings in this disorder.     

Neonatal pain management.

Neonatal pain management is a challenge for the clinician. Research is just beginning to uncover the neonates' capability of expression of pain, explore pharmacologic management strategies, and identify the spectrum of intrusions that may precipitate pain or distress in the critically ill neonate. This article reviews the neonatal biologic, behavioral, and physiologic responses to pain and describes recommendations for clinical management and decision-making.     

Competitive dissociation of encephalitogenic complexes between antigen presenting cells and myelin basic protein

Splenic T cells from myelin basic protein (MBP)-immunised Lewis rats were activated to transfer experimental autoimmune encephalomyelitis (EAE) by co-culture with MBP-pulsed lymphoid dendritic cells (DC). MBP-pulsed DC could be kept for at least 24 h at 37 degrees C in antigen-free medium without affecting their ability subsequently to activate encephalitogenic T cells. However, MBP-pulsed DC were rendered much less stimulatory after a 6 h, but not 2 h, secondary incubation with ovalbumin. Thus, although encephalitogenic complexes between MBP and DC appear very stable in the absence of competing antigens, in their presence, antigen exchange can take place over a period of a few hours; this has positive implications for therapy of EAE by antigen competition.     

TRANSCONJUNCTIVAL OOZING AFTER GLAUCOMA SURGERY

Aim: To study the prevalence of filtration-bleb transconjunctival oozing in the first postoperative year after various glaucoma procedures. Methods: Cross-sectional, single-point examination of all filtration blebs in eyes which had glaucoma surgery in the last year. Eyes were examined 3-12 months after surgery and were grouped into non-penetrating (NPGS) and penetrating (PGS)     

用丝裂霉素C行青光眼加强手术：滤过泡无血管化及经结膜渗漏和滤过泡裂孔的发生

目的：前瞻性研究青光眼术中应用丝裂霉素C（MMC）对于结膜滤过泡高危因素如无血管化、经结膜的渗漏（TCO）和滤过泡裂孔的影响。方法：一位观察者对进行了青光眼手术联合MMC的125例连续患者的125只眼进行为期2年的前瞻性研究，这些患者最初都成功地建立了滤过通道。巩膜瓣切开前将MMC置于该区，多数患者MMC0．2g／L持续2min。青光眼手术包括小梁切除术、深巩膜切除术和联合手术。将干燥的荧光素试纸置于滤过泡的无血管区，以观察房水外流[点渗漏（PL）或未流出（TCO）]。     

Evaluation of xanthotoxol for central nervous system activity.

Xanthotoxol (XT), 8-hydroxypsoralen, exhibited dose-graded sedative activity in dogs, cats, rats, mice and hamsters. At doses of 5-20 mg/kg intraperitoneally (i.p.) in cats and 3-100 mg/kg orally (p.o.) in dogs, XT blocked predatory mouse/rat killing behavior. In mice, XT (10-300 mg/kg i.p.) exhibited a dose-dependent reduction in locomotor activity but was less potent in this regard than reference diazepam (10-100 mg/kg i.p.). XT in mice (0.1-10.0 mg/kg i.p.) and in hamsters (0.1-10.0 mg/kg p.o.) antagonized amphetamine-induced hypermobility but was less potent than diazepam. XT elevated the electrical threshold in foot-shock-induced fighting behavior in rats. XT (0.1-30.0 mg/kg p.o.) potentiated pentobarbital-induced narcosis in hamsters at otherwise subeffective doses of pentobarbital. Conditioned avoidance responses in rats were not significantly altered with 1-3 mg/kg i.p. and 30-100 mg/kg p.o. doses of XT but 300 mg/kg p.o. blocked both conditioned and unconditioned response. Doses of 100-1000 mg/kg i.p. of XT in mice were used to study 48-h acute toxicity of XT and its LD50 was estimated to be 468 mg/kg. Doses of 10, 40 and 80 mg/kg p.o. were used to study the chronic toxicity of XT in rats for 6 months and no side effects or abnormalities in reproductive activity or endocrine integrity were noted. The F1 generation of rats from 6-month XT-treated parents were free of teratogenic effects.