The neurobiology of chronic pain states

Plasticity enables alterations in transmission in nociceptive systems. It is this plasticity in the nervous system that can alter the linear relation between noxious stimuli and the perception of pain and is important in the switch from acute to chronic pain. In this way, a number of CNS mechanisms can alter neuronal activity, leading to abnormal ongoing and stimulus-evoked pains due to peripheral and central changes. Peripheral nerves can become sensitized, spinal cord neurons can be rendered hyperexcitable and ascending projections to higher centres can further trigger changes in descending controls from the midbrain and brainstem. Together, these changes, all of which appear to involve reversible physiological and pharmacological plasticity, can alter the relationship between an applied stimulus and the perceived response and so lead to persistent pain states.     

中药穴位敷贴联合中药汤剂治疗糖尿病周围神经病变临床观察

目的探究糖尿病周围神经病变患者开展中药穴位敷贴联合中药汤剂治疗的效果。方法研究时限为2017年8月—2018年11月,研究对象为此期间收治的糖尿病周围神经病变患者42例,将其随机分为常规组(21例)、中药组(21例),分别开展常规治疗、中药穴位敷贴+中药汤剂治疗,比较治疗结果。结果2组患者治疗前中医证候积分、TCSS(多伦多临床评分)相近(P>0.05),治疗后中药组患者以上评分均较常规组具鲜明优势(P<0.05);常规组患者不良反应发生率为14.3%,与中药组0.0%相比,未见鲜明差异(P>0.05)。结论予糖尿病周围神经病变患者开展中药穴位敷贴联合中药汤剂治疗,效果安全有效。     

Inherited focal, episodic neuropathies

Hereditary neuropathy with liability to pressure palsies (HNPP; also called tomaculous neuropathy) is an autosomal-dominant disorder that produces a painless episodic, recurrent, focal demyelinating neuropathy. HNPP generally develops during adolescence, and may cause attacks of numbness, muscular weakness, and atrophy. Peroneal palsies, carpal tunnel syndrome, and other entrapment neuropathies may be frequent manifestations of HNPP. Motor and sensory nerve conduction velocities may be reduced in clinically affected patients, as well as in asymptomatic gene carriers. The histopathological changes observed in peripheral nerves of HNPP patients include segmental demyelination and tomaculous or “sausage-like” formations. Mild overlap of clinical features with Charcot-Marie-Tooth (CMT) disease type 1 (CMT1) may lead patients with HNPP to be misdiagnosed as having CMT1. HNPP and CMT1 are both demyelinating neuropathies, however, their clinical, pathological, and electrophysiological features are quite distinct. HNPP is most frequently associated with a 1.4-Mb pair deletion on chromosome 17p12. A duplication of the identical region leads to CMT1A. Both HNPP and CMT1A result from a dosage effect of the PMP22 gene, which is contained within the deleted/duplicated region. This is reflected in reduced mRNA and protein levels in sural nerve biopsy samples from HNPP patients. Treatment for HNPP consists of preventative and symptom-easing measures. Hereditary neuralgic amyotrophy (HNA; also called familial brachial plexus neuropathy) is an autosomal-dominant disorder causing episodes of paralysis and muscle weakness initiated by severe pain. Individuals with HNA may suffer repeated episodes of intense pain, paralysis, and sensory disturbances in an affected limb. The onset of HNA is at birth or later in childhood with prognosis for recovery usually favorable; however, persons with HNA may have permanent residual neurological dysfunction following attack(s). Episodes are often triggered by infections, immunizations, the puerperium, and stress. Electrophysiological studies show normal or mildly prolonged motor nerve conduction velocities distal to the affected brachial plexus. Pathological studies have found axonal degeneration in nerves examined distal to the plexus abnormality. In some HNA pedigrees there are characteristic facial features, including hypotelorism. The prognosis for recovery of normal function of affected limbs in HNA is good, although recurrent episodes may cause residual deficits. HNA is genetically linked to chromosome 17q25, where mutations in the septin-9 (SEPT9) gene have been found.     

MBP对PBMC产生IFN-γ和NO的影响

目的探讨T细胞非特异性活化在CNS脱髓鞘性疾病中的作用。方法分离实验性自身免疫性脑脊髓炎(EAE)易感性BALB/c小鼠外周血单个核细胞(PBMC),采用体外细胞培养方法在体外与碱性髓鞘蛋白(MBP)共培养,测定培养上清液中IFN-γ、NO水平。结果经MBP刺激的PBMC产生IFN-γ[(43.83±6.06)pg/mL]和NO[(180.76±20.75)μmol/L]明显增加,与对照组产生的IFN-γ[(28.52±2.18)pg/mL]和NO[(95.61±13.09)μmol/L]相比差异有统计学意义(P<0.01)。结论在CNS脱髓鞘性疾病发病过程中,活化的T细胞、单核细胞等分泌致炎细胞因子和其他有害物质增多。     

The difference in blood pressure between upper arm and finger during physical exercise

Summary. A new apparatus which measures the blood pressure in the finger continuously and yet not invasively was tested for its usefulness during exercise. It was compared with upper arm measurements in 23 volunteers during prolonged bicycle ergometry. Simultaneously, a pulse plethysmogram was recorded from another finger of the same arm, whereas in six additional volunteers Doppler measurements were carried out on the radial artery. The results show that finger systolic pressure ceased to rise at about 40% of maximal exercise; the difference with the continuously rising systolic pressure in the upper arm becoming significant at 140 W. At the same time the amplitude of the finger plethysmogram became significantly higher than its initial value, indicating distinct cutaneous vasodilation, whereas the volunteers also became hot and started to perspire. However, the radial artery ‘flow’, deduced from the Doppler measurements, did not change significantly during exercise. It increased sharply and markedly in the cooling down period. Simultaneously with this increase in flow, HR and both systolic blood pressures fell drastically whereas the plethysmography amplitude remained about stable at its raised level. The results fit in with the idea that a compromise is achieved between the need for muscle activity and the need for temperature regulation. It is concluded that the Finapres functions well during exercise, but that the systolic pressure in the finger is not representative for its more central counterpart during cutaneous vasodilation. It is argued that opening up of AVAs may contribute to this pressure effect.     

Cutaneous nerves in patients with diabetic neuropathy--an electron microscopic study

Since the role of cutaneous nerves in the pathogenesis of cutaneous diseases associated with diabetes mellitus is not well defined, cutaneous nerves in ten patients with severe diabetic neuropathy were electron microscopically investigated as a preliminary study. The specimens were taken from normal-appearing skin of their lower extremities. Cutaneous nerves were seen as axon-Schwann cell complexes in which variously degenerated axons and Schwann cells coexisted with normal ones. The degenerative changes were not, however, specific for diabetes mellitus.