[Effect of mild and strong manual acupuncture stimulation of "Huantiao" (GB 30) on mechanical pain thresholds and extracellular signal-regulated kinase protein expression in spinal dorsal horns in rats with neuropathic mirror-image pain].

OBJECTIVE: To observe the effect of different intensities of manual acupuncture (MA) stimulation on mechanical pain thresholds (PTs) and the expression of phosphorylated extracellular signal-regulated kinases (p-ERK) in lumbar spinal dorsal horn regions in rats with neuropathic mirror-image pain, so as to explore its mechanisms underlying analgesia. METHODS: Forty male SD rats were equally and randomly divided into control, spinal nerve ligation (SNL) model, mild MA-stimulation, and strong MA-stimulation groups. Neuropathological pain model was established by ligature of the spinal nerve (L 5). Three days after the SNL, bilateral "Huantiao" (GB 30) were stimulated by rotating the thin (0.22 mm x 13 mm) or thick (0.3 mm x 13 mm) filiform needles at a frequencies of 60 times/min or 180 times/min and at an angle of 180 degrees or 360 degrees for 2 min for rats in the mild and strong MA-stimulation groups, respectively, followed by remaining the needle in place for 30 min. The mechanical PTs were measured before and after SNL. The expression of p-ERK protein in bilateral dorsal horn regions of the lumbar spinal cord (L4- L 6) was detected by Western blot. RESULTS: In comparison with the control group, the mechanical PTs were significantly decreased beginning from the 3rd day on after SNL on the affected side and from the 7th day on after SNL on the healthy hindpaw (P < 0.05), simultaneously, p-ERK protein expression levels of dorsal horn regions on both sides of the spinal cord were considerably up-regulated on the 12th day (P < 0.05). Compared with the model group, the PTs of the affected hindpaw and the healthy hindpaw were significantly increased on the 7th and 12th day in the strong MA-stimulation group (P < 0.05, P < 0.01), whereas pERK expression levels in the bilateral spinal dorsal horn regions were obviously down-regulated in the strong MA-stimulation group (P < 0.05). No significant differences were found between the model and mild MA-stimulation groups in the PTs of bilateral hindpaws and p-ERK expression levels of the bilateral spinal dorsal horn regions (P > 0.05) except the PTs of the healthy hindpaw on 7th day (P < 0.05). CONCLUSION: Strong MA-stimulation can alleviate neuropathic mirror-image pain in SNL rats, which is closely related to its effect in down-regulating the expression of p-ERK in the bilateral spinal dorsal horn regions.

[Immediate analgesic effect of electroacupuncture and its regulation mechanism via spinal p-ERK1/2].

OBJECTIVE: To observe influence of electroacupuncture (EA) on phosphorylation of extracellular signal-regulated kinases 1/2 (ERK1/2) in spinal cord dorsal horn (SCDH) in rats with acute inflammatory pain induced by complete Freund's adjuvant (CFA), further elucidate the immediate analgesic mechanism of EA via cellular signal transduction. METHODS: Fifty-three healthy male SD rats were divided into two batches. The inflammatory pain models of the first batch of 23 rats were established by using CFA. The changes of the paw withdrawal thresholds (PWTs) of rats were observed and positive cells of p-ERK1/2 in affected SCDH were detected by using immunohistochemistry method. The second batch of 30 rats were randomly divided into a blank control group (N group), CFA group and EA group, 10 rats in each group. The rats of CFA group and EA group were induced inflammatory pain by using CFA, and the EA group was treated with EA at 5.5 h after the model establishment. The changes of PWTs and the positive cells of p-ERK1/2 in SCDH were observed. RESULTS: The PWTs of the first batch of rats obviously decreased at 5 h, 3 d, 7 d and 14 d after CFA administration (all P< 0.01). However, the p-ERK1/2 positive cells in affected SCDH only increased at 5 h after CFA-injection and returned to normality at 3 d after the model establishment. In the second batch, compared with that of N group at the same time point, PWTs of rats in both CFA and EA group obviously decreased after the model establishment (both P<0.01). PWTs of rats in EA group which accepted EA treatment once were longer than those before EA treatment and corresponding PWTs in CFA group at the same time point (both P<0.01). Moreover, the numbers of p-ERK1/2 positive cells of affected SCDH increased significantly in CFA group at 6 h after the model establishment (P<0.01), however, which were decreased significantly in EA group (P<0.01). CONCLUSION: Inhibiting ERK1/2 activation of SCDH may be one of the pivotal mechanism of cellular signal transduction of the immediate analgesic effect educed by EA.

The spine in ß-thalassemia syndromes.

STUDY DESIGN: Literature review. OBJECTIVE: To present a comprehensive overview of spinal involvement in patients with ß-thalassemia, aiming to orient the spinal surgeon to these potentially disabling complications. SUMMARY OF BACKGROUND DATA: ß-thalassemia, an inherited disorder of hemoglobin synthesis, is the most common monogenetic disease worldwide. Patients with thalassemia major (TM) suffer a severe anemia that requires regular blood transfusions for survival and iron chelation therapy to control transfusional iron overload. Thalassemia intermedia is a phenotype of thalassemia with a milder course and anemia, wherein most patients remain transfusion independent. Spinal involvement related to disease course and treatment is common in patients with thalassemia syndromes, yet it has not been constructively reviewed in the literature. METHODS: Potentially relevant studies were identified from an electronic search of MEDLINE (1966 to the second week of May 2010). RESULTS: In patients with TM, genetic and acquired risk factors lead to osteoporosis, pathologic fractures of the spine, and back pain. Osteoporosis in TM patients is progressive; thus, early diagnosis and treatment are recommended. Bisphosphonates are relatively safe and effective in this patient population. Characteristic intervertebral disc degeneration is also seen in patients with TM who have evidence of severe iron overload or those who receive the subcutaneous iron chelator deferoxamine. Spinal asymmetry and overt scoliosis are common in patients with TM. The prognosis seems favorable, with many patients showing spontaneous resolution without the need for intervention. In patients with thalassemia intermedia, ineffective erythropoiesis drives extramedullary hematopoietic tissue formation, which is mostly evident on magnetic resonance imaging. Paraspinal involvement is of greatest concern because of the associated spinal cord compression. Several treatment options have been described, including transfusion therapy, laminectomy, radiotherapy, and the use of fetal hemoglobin-inducing agents that decrease the hematopoietic drive. CONCLUSION: Current knowledge supports that spinal involvement in patients with ß-thalassemia is common and diverse yet still requires further prospective evaluation.