ABSTRACT
AIM:To investigate the role of specific binding of precursor form of nerve growth factor(proNGF) to p75NTR(proNGF-p75NTR)in isoflurane-induced cognitive impairment in aging mice.METHODS: Aging C57BL/6J male mice were randomly divided into 3 groups:control group,isoflurane(Iso)group and p75NTR specific inhibitor 2-ami-no-3-methyl-pentanoic acid amide(LM11A-31,LM)+isoflurane(LM+Iso)group.Aging C57BL/6J mice in Iso group and LM+Iso group were exposed to isoflurane,and the mice in control group were exposed to air.The mice in LM+Iso group were treated with LM,which dissolved in normal saline water and was administered daily by oral gavage at 50 mg· kg-1· d-1for 1 month.The mice in control group and Iso group received an equivalent volume of normal saline by the same route.Arterial blood gas analysis was conducted to detect the physiological state of the mice after isoflurane exposure. Morris water maze was performed to evaluate the cognitive function.The protein levels of proNGF,p75NTR,phosphorylated p38 MAPK and cleaved caspase-3 were determined by Western blot.RESULTS: Compared with the control group, the protein expression of proNGF and p75NTR in the hippocampus of Iso group was significantly elevated(P<0.05).The phos-phorylation level of p38 MAPK was higher in Iso group than that in control group(P<0.05),which was reduced in LM +Iso group significantly(P<0.05).A significant increase in the protein level of cleaved caspase-3 was observed in Iso group as compared with control group(P<0.05), while LM11A-31 treatment reversed this elevation significantly(P<0.05).The escape latency prolonged and the number of crossing the original platform location reduced in Iso group com -pared with control group(P<0.05), which were reversed by LM11A-31 in LM+Iso group(P<0.05).CONCLU-SION:ProNGF-p75NTR probably plays an vital role in the apoptotic pathway activation and the cognitive dysfunction in ag -ing mice exposure to isoflurane,which provides a potential target for clinical intervention.
ABSTRACT
<p><b>OBJECTIVE</b>To retrospectively analyze and evaluate the results of treatment for atlantoaxial instability or dislocation employing pedicle screws of atlas and axis.</p><p><b>METHODS</b>Thirty-one patients (23 male and 8 female) with atlantoaxial instability or dislocation were stabilized using pedicle screws of atlas and axis between May 2005 to January 2008. The patients ranged in age from 17 to 67 years (mean 43.5 years). Patients consisted of chronic odontoid fracture in 17, Os odontoideum in 8, fresh odontoid fracture in 4, transverse ligament rupture in 1, rheumatoid arthritis in 1. Clinical features included neck pain in 31; restricted neck movement in 28, varying degrees of spastic quadriparesis in 19. All patients underwent posterior C(1) to C(2) pedicle screw fixation. Operative time, intraoperative blood loss, complications were recorded, neurological and radiographic studies were carried.</p><p><b>RESULTS</b>Mean follow-up time was 13 months. Operative time averaged 2.5 h. Mean intraoperative blood loss was 300 ml. A patient had postoperative wound infection and was treated conservatively with antibiotics and local wound care. A patient developed pulmonary artery embolism and got well with anticoagulation. Satisfactory stability was achieved in all cases with no vascular and C(2) neuralgia. Average JOA score in 19 cases increased at final follow-up (P < 0.01). Solid fusion was achieved in 29 cases, fusion rate was 93.6%.</p><p><b>CONCLUSIONS</b>Stabilization of atlantoaxial complex via pedicle screws of atlas and axis has advantages of intraoperative restoration, easier placement of screw, solid fixation. It is a safe and effective treatment modality for posterior C(1-2) fusion.</p>