Animals ; Humans ; Pain ; physiopathology ; Pruritus ; physiopathology

Face ; physiopathology ; Humans ; Mouth ; physiopathology ; Pain ; Pain Threshold ; Somatoform Disorders

Humans ; Infant, Newborn ; Pain ; diagnosis ; physiopathology ; Pain Management ; Pain Measurement

Diabetic peripheral neuropathy (DPN), one of the most common chronic complications of diabetes, is characterized by allodynia, hyperalgesia and spontaneous pain. Chinese epidemiological studies have shown that at least 25% diabetic patients suffered from painful DPN, which compromises patients' daily functioning and becomes a major health care problem. Although the pathogenesis of painful DPN is not fully understood and current treatment options are very limited, research in the field has advanced our understanding on the mechanism of painful DPN in the past Decade of Pain Research and Control. This review will mainly focus on evaluation of current diabetic animal models, possible molecular pathways and available therapies, with an emphasis on roles of purinergic receptor and its signaling transduction pathways. Common therapies address one or two DPN symptoms, while others offer wider symptom control, presumably by targeting pathophysiological mechanisms of DPN. Purinergic receptor signaling transduction pathways might become potential targets for treatment for painful DPN.
Animals ; Diabetes Mellitus ; physiopathology ; Diabetic Neuropathies ; physiopathology ; Humans ; Hyperalgesia ; physiopathology ; Pain ; physiopathology ; Receptors, Purinergic P2X ; physiology

BACKGROUNDEndometriosis is a controversial and enigmatic disease. Deep infiltrating endometriosis (DIE) is responsible for painful symptoms and is the least understood type of endometriosis. Little work has been devoted to define the location of DIE lesions and its relationships with pain. The aim of the study was to investigate the relationship between the anatomical distribution of DIE lesions and pain symptoms.

METHODSClinical data from 354 patients between May 2003 and December 2007 with laparoscopically diagnosed endometriosis were collected including 177 DIE patients and 177 non-DIE patients. The pain symptoms, including dysmenorrhea (DM), chronic pelvic pain (CPP, defined as intermittent or permanent pelvic pain, not related to the menstruation and longer than 6 months), deep dyspareunia (pelvic pain at intercourse) and dyschezia (pelvic pain with defecation), were recorded for every patient before operation. Endometriotic lesions were recorded by their anatomical distributions, the depth of infiltration and lesion colors. And the relationship between the anatomical distribution of DIE lesions and pain symptoms was analyzed. Pearson's chi-square test or Fisher's exact test, one-way analysis of variance (ANOVA) and linear regression and binary Logistic regression were used for statistical analysis.

RESULTSThe duration ((13.79 ± 3.94) years) of pain suffering in DIE patients was much longer than that of non-DIE patients (P < 0.01). In DIE patients, 60.7% of the uterosacral ligament (USL) nodules were bilateral (P < 0.01); 44.6% of the cul-de-sacs were completely blocked. Rectum invasion was observed in 19.9% of DIE patients (P = 0.03); pelvic adhesion was also more common. Up to 98.41% of the deep infiltrative lesions were located in the posterior pelvic compartment. DIE lesions were also found in bladder (1.58%), USL (67.08%), cul-de-sac (12.02%), recto-vaginal septum (12.66%), rectum and rectosigmoid junction (2.85%) and ureter (3.80%). The odds ratio of USL-DIE for CPP, deep dyspareunia, dyschezia were 2.52, 1.29 and 2.24 respectively. And the depth of infiltration correlated with the severity of dysmenorrhea.

CONCLUSIONSDIE lesions were associated with severe pain symptoms. The main distribution of DIE lesions was in the posterior pelvic compartment, and was more widespread and severe in DIE patients. Moreover, resection of these DIE lesions are very important to treat the pain symptoms.

Adult ; Constipation ; physiopathology ; Dysmenorrhea ; physiopathology ; Endometriosis ; pathology ; physiopathology ; Female ; Humans ; Pelvic Pain ; physiopathology ; Prospective Studies

One hundred infants were divided into the following 3 gestational age (GA) groups: (I) premature infants (n = 30) with the gestational age between 29 and 32 weeks; (II) premature infants (n = 30) with the gestational age between 33 and 36 weeks; (III) full-term infants (n = 40). The recorded responses of all infants to pain included the behavioral responses to painful stimuli (cry, facial activity and limbs movement) and the variety of heart rate. The results indicated that the infants of 3 groups had different degree response to various painful stimuli. Pain expression in full term infants was more significant than premature infants to same stimuli. 33-weeks GA infants were differential from 29-weeks GA infants. Full term infants showed more vertical mouth stretch and more taut tongue and more hand to mouth than premature infants, but more horizontal mouth stretch in premature infants.
Gestational Age ; Infant, Newborn/*physiology ; Pain/*physiopathology ; Pain Measurement/*methods

Acupuncture ; Acupuncture Points ; Animals ; Brain ; physiopathology ; Electroacupuncture ; Humans ; Magnetic Resonance Imaging ; Pain ; physiopathology ; Pain Management

The aim of the present study was to examine whether the thalamic nucleus submedius (Sm) was involved in the modulation of persistent nociception. Using an automated movement detection system to measure nociceptive behavior (agitation) induced by subcutaneous injection of formalin into the hind paw pad, the effects of electrical stimulation or electrolytic lesion of the Sm on the agitation response were examined in conscious rats. Unilateral stimulation (100 μA, 5 min) of the Sm ipsilateral or contralateral to the formalin-injected paw produced a significant inhibition of agitation response in the second phase, while stimulation of thalamic structures more than 0.5 mm away from the Sm had no effect on agitation response. Bilaterally electrolytic lesion of the Sm did not significantly influence the number of agitation events induced by formalin injection in the first phase or the second phase. These results suggest that the Sm is not only involved in the modulation of phase nociception, as reported previously, but also of persistent nociception. The present study provides novel evidence for the participation of the Sm in descending modulation of pain.
Animals ; Electric Stimulation ; Formaldehyde ; Nociception ; Pain ; physiopathology ; Pain Measurement ; Rats ; Thalamic Nuclei ; physiopathology

According to the comparison between Ashi points and trigger points, a modern medical explanation that trigger points could be considered as a special Ashi points was put forward, and a further investigation on the enlightenment of theory and practice of trigger points to the pathological specificity, positioning and the intervention methods of trigger points was as follows: Ashi points could be central trigger points, whose pathology is degeneration and contracture of sarcomere; it is not always in the area of pain, while the signs of pain may be helpful for its stereotaxic positioning; the intervention methods of Ashi and trigger points can be learned from each other. This is a new angle of view on Ashi points, which has contributed to the exploration and improvement of its theory and practice.
Acupuncture Points ; Acupuncture Therapy ; Humans ; Pain ; physiopathology ; Pain Management ; Trigger Points ; physiopathology

Peripheral nerve injury frequently leads to neuropathic pain like hyperalgesia, spontaneous pain, mechanical allodynia, thermal allodynia. It is uncertain where the neuropathic pain originates and how it is transmitted to the central nervous system. This study was performed in order to determine which peripheral component may lead to the symptoms of neuropathic pain. Under halothane anesthesia, male Sprague-Dawley rats were subjected to neuropathic surgery by tightly ligating and cutting the tibial and sural nerves and leaving the common peroneal nerve intact. Behavioral tests for mechanical allodynia, thermal allodynia, and spontaneous pain were performed for 2 weeks postoperatively. Subsequently, second operation was performed as follows: in experiment 1, the neuroma was removed; in experiment 2, the dorsal roots of the L4-L6 spinal segments were cut; in experiment 3, the dorsal roots of the L2-L6 spinal segments were cut. Behavioral tests were performed for 4 weeks after the second operation. Following the removal of the neuroma, neuropathic pain remained in experiment 1. After the cutting of the L4-L6 or L2-L6 dorsal roots, neuropathic pain was reduced in experiments 2 and 3. The most remarkable relief was seen after the cutting of the L2-L6 dorsal roots in experiment 3. According to the fact that the sciatic nerve is composed of the L4-L6 spinal nerves and the femoral nerve is composed of the L2-L4 spinal nerves, neuropathic pain is transmitted to the central nervous system via not only the injured nerves but also adjacent intact nerves. These results also suggest that the dorsal root ganglion is very important in the development of neuropathic pain syndrome.
Animal ; Ganglia, Spinal/physiopathology ; Male ; Nervous System Diseases/physiopathology* ; Nervous System Diseases/complications ; Pain/physiopathology* ; Pain/etiology ; Rats ; Rats, Sprague-Dawley ; Spinal Nerve Roots/physiopathology ; Spinal Nerves/physiopathology