Objective To investigate the correlation between blood pressure variability and variabilities of some feature variables extracted from photoplethysmography (PPG) signal.Methods Continuous blood pressure (BP) and PPG signal were collected simultaneously from 19 healthy subjects under rest and after exercise.Eight feature variables were extracted from the PPG signal.The relationship between the beat-to-beat variability of BP and feature variables extracted from PPG were quantified by calculating Person's correlation coefficient.Results The variability of the amplitude of PPG was highly correlated with systolic BP variability both under rest (0.75) and after exercise (0.76).Meanwhile,the correlations between systolic BP variability and the variability of the time from the trough to the dicrotic north were 0.74(under rest) and 0.78(after exercise).Conclusion The amplitude variability of PPG is highly correlated with systolic BP variability and can be potentially used for monitoring BP variability.

[ ABSTRACT] Rebound depolarization is a special phenomenon of the neurons which generates action potential fol-lowed by a hyperpolarization stimulation.It can be recorded in many kinds of neurons and is the intrinsic membrane charac-teristic of them.Rebound depolarization plays an important role in regulating the firing pattern, rhythmic activity and sy-naptic plasticity of neurons.This review focuses on the basic characteristics, the function and mechanism of the rebound depolarization in physiological and pathological conditions, which provides reference for the clinical treatment of rebound depolarization-related diseases.

Objective To observe the efficacy and safety of radiofrequency thermocoagulation of lumbar sympathetic ganglia combined with pregabalin in the treatment of complex regional pain syndrome(CRPS).Methods 26 patients with lower limb CRPS were selected and treated by the radiofrequency thermocoagulation of lumbar sympathetic ganglia combined with oral pregabalin capsule.The visual analogue scale (VAS)and the quality of sleep(QS)were adopted to evaluate the pain change before treatment and on 1,7,14,28,56 d after treatment.The temperature change of lower limb skin and the occurrence situation of adverse reactions were recorded.Results Compared with before treatment,the scores of VAS and QS at different time points after treatment were decreased significantly (P <0.05),the skin temperature of affected lower limb after treatment was increased significantly (P <0.05).The total effective rates on 28,56 d after treatment were 88.46% and 96.15% respectively.The adverse reactions were mainly dizziness and somnolence.No severe complications such as vascular,neural and intra-abdominal organs injury were found in the treatment process.Conclusion The radiofrequency thermocoagulation of lumbar sympathetic ganglia combined with pregabalin in the treatment of CRPS can rapidly alleviate pain,improve the patients′quality of sleep and living.

OBJECTIVETo investigate the effect of minocycline on hyperpolarization-activated current (Ih) in the substantia gelatinosa (SG) neurons in rat spinal dorsal horn.

METHODSIn vitro spinal cord transverse slices were prepared from 3-5-week-old male Sprague-Dawley rats. Using whole-cell patch clamp technique, Ih currents were recorded before and after bath application of minocycline (1-300 µmol/L) to the SG neurons.

RESULTSIh currents were observed in nearly 50% of the recorded neurons, and were blocked by Ih blocker CsCl and ZD7288. Minocycline rapidly and reversibly reduced the amplitude of Ih and decreased the current density in a concentration-dependent manner with an IC50 of 34 µmol/L.

CONCLUSIONMinocycline suppresses the excitability of SG neurons through inhibiting the amplitude and current density of Ih and thereby contributes to pain modulation.

Animals ; Male ; Minocycline ; pharmacology ; Neurons ; drug effects ; Patch-Clamp Techniques ; Rats ; Rats, Sprague-Dawley ; Substantia Gelatinosa ; cytology

OBJECTIVETo evaluate trends of overweight and obesity prevalence between 1996 and 2007 in Yi farmers and Yi migrants.

METHODSAn Yi migrant study was conducted in Liangshan Yi Autonomous Prefecture, Sichuan Province, China from 1996 to 2007. Data were collected with identical methods, including standardized questionnaire and body measurements.

RESULTSAge- and sex-specific body mass index (BMI) significantly increased from 20.02 in 1996 to 22.36 in 2007, among Yi farmers, which was significantly different from those among Yi migrants (23.67 in 2007 and 20.90 in 1996) (P<0.05). Prevalence of obesity rose from 1.21 % in 1996 to 4.55 % in 2007 (OR=1.15, P<0.001) in Yi migrants, while that in Yi farmers from none in 1996 to 0.12 % in 2007 (P>0.05). Prevalence of overweight rose significantly to 26.24 % in 2007 from 17.24 % in 1996 (OR=1.06, P<0.001) in Yi migrants, while that in Yi farmers from 1.29 % in 1996 to 4.45 % in 2007 (OR=1.14, P>0.001). Yi migrants appeared to have a 5.52-fold higher risk on developing overweight and obesity than Yi farmers have.

CONCLUSIONThe Yi migrants had a steeper increase of overweight with year and consequently caused more obesity. Change in lifestyle may contribute most likely to higher prevalence of overweight and obesity in Yi migrants.

Adult ; Agriculture ; statistics & numerical data ; trends ; Body Mass Index ; China ; epidemiology ; Female ; Humans ; Male ; Middle Aged ; Obesity ; epidemiology ; Overweight ; epidemiology ; Prevalence ; Rural Population ; statistics & numerical data ; Transients and Migrants ; statistics & numerical data ; Urban Population ; statistics & numerical data ; Young Adult

The thalamocortical (TC) circuit is closely associated with pain processing. The hyperpolarization-activated cyclic nucleotide-gated (HCN) 2 channel is predominantly expressed in the ventral posterolateral thalamus (VPL) that has been shown to mediate neuropathic pain. However, the role of VPL HCN2 in modulating TC circuit activity is largely unknown. Here, by using optogenetics, neuronal tracing, electrophysiological recordings, and virus knockdown strategies, we showed that the activation of VPL TC neurons potentiates excitatory synaptic transmission to the hindlimb region of the primary somatosensory cortex (S1HL) as well as mechanical hypersensitivity following spared nerve injury (SNI)-induced neuropathic pain in mice. Either pharmacological blockade or virus knockdown of HCN2 (shRNA-Hcn2) in the VPL was sufficient to alleviate SNI-induced hyperalgesia. Moreover, shRNA-Hcn2 decreased the excitability of TC neurons and synaptic transmission of the VPL-S1HL circuit. Together, our studies provide a novel mechanism by which HCN2 enhances the excitability of the TC circuit to facilitate neuropathic pain.
Animals ; Mice ; Hyperpolarization-Activated Cyclic Nucleotide-Gated Channels/genetics* ; Neuralgia ; RNA, Small Interfering ; Thalamus/metabolism* ; Up-Regulation