OBJECTIVESTo investigate the expression of macrophage migration inhibitory factor (MIF) mRNA in Schwann cells after peripheral nerve injury and roles of Schwann cells and MIF in macrophages activation and nerve regeneration.

METHODSFifty SD rats were divided into 10 groups. One group served as normal control. The rest were anesthetized with 3% sodium pentobarbital (30 - 60 mg/kg, i.p) and sciatic nerves were transected distal to the obturator tendon respectively 1 h, 12 h, 1 d, 3 d, 7 d, 10 d, 14 d, 17 d and 21 d before being killed. Sciatic nerves were resected and connective tissues excised. Schwann cells were obtained by digesting the nerve tissues with trypsin and collagenase. RNA was isolated and reverse-transcription-polymerase chain reaction (RT-PCR) was carried out. cDNA was analyzed by automatic system and the parameters were assessed to define the status of MIF mRNA expression in different groups.

RESULTSThe level of MIF mRNA started to increase 12 h after the nerve transection. The level remained high from day 7 up to 10 after the injury. During the period from days 10 to 21, MIF mRNA decreased slowly to the pre-transection level.

CONCLUSIONAfter peripheral nerve injury, Schwann cells can secrete MIF which may play a pivotal role as an immunomodulatory cytokine in macrophage activation and inflammatory reaction.

Animals ; Female ; Macrophage Migration-Inhibitory Factors ; genetics ; Male ; Peripheral Nerve Injuries ; RNA, Messenger ; analysis ; Rats ; Rats, Sprague-Dawley ; Reverse Transcriptase Polymerase Chain Reaction ; Schwann Cells ; metabolism

Objective : To investigate the efficacy of standardized allergen subcutaneous immunotherapy (SCIT) in children with asthma sensitized to single dust mite allergens versus multiple allergens and to assess the safety of SCIT. Methods : 62 children with confirmed allergic asthma who received standardized allergen SCIT were retro⁃ spectively analyzed and divided into the monosensitized group (dust mite results≥ + + + ) and the polysensitized group (dust mite results ≥ + + + combined with other positive allergens) according to the results of skin pricktest , we observed the changes of pulmonary function , medication score and visual analog scale (VAS) scores , children asthma control test (C - ACT) scores , asthma control questionnaire (ACQ) scores before and after treatment in both groupsand compared the efficacy of the two groups. The incidence of local and systemic adverse effects was recorded during treatment in all children to assess the safety of SCIT. Results : Standardized allergen SCIT treatmentimproved lung function parameters , medication scores and VAS scores , C ⁃ACT scores , ACQ scores in both the monosensitized and polysensitized groups , with statistically significant differences before and after treatment (P < 0. 05) . In comparison between the two groups , lung function parameters [forced expiratory flow at 50% vital capacity(FEF50% ) , maximum midexpiratory flow(MMEF)] , medication scores , C ⁃ACT scores and ACQ scores improved significantly in the monosensitized group compared with the polysensitized group after treatment ( P <0. 001) . 62 patients received a total of 2 606 injections during the treatment of SCIT , 6 children had a total of 10 local adverse reactions and 3 children had 3 mild to moderate systemic adverse reactions , with an incidence of 0. 38% for local adverse reactions and 0. 12% for systemic adverse reactions. Conclusion The children with asthma in both the monosensitized group and polysensitized group achieved significant and safe clinical outcomes under standardized allergen SCIT. The children in the monosensitized group had more obvious clinical effects than the polysensitized group under standardized allergen SCIT.