Objective To evaluate the effect of hypothermia on somatosensory evoked potentials (SSEPs). Methods Thirteen ASA Ⅱ or Ⅲ patients aged 23-51 yr weighing 45-82 kg scheduled for cardiac surgery were enrolled in this study. Bilateral median nerve SSEPs (N9, N13, N20) were recorded after induction.The MAP, peak latency and amplitude of N9, N13 and N20 were recorded when the target temperature (36, 35,34, 33 ℃ ) was reached during the cooling and rewarming periods. The neurological dysfunction was recorded after operation. Results The peak latency was prolonged and MAP was decreased with the decrease in the body temperature during the cooling period, the peak latency was shortened with the increase in the body temperature during the rewarming period ( P ＜ 0.05), but no significant change in the amplitudes was found ( P ＞ 0.05). The regression equation of the interaction between the peak latency and body temperature was YN9= -0.558X + 28.994(r=-0.673), YN13 =-1.121X+53.242 (r= -0.702) , YN20 = -1.458X+72.036(r= -0.702) during the cooling period (P ＜ 0.05), and YN9 = - 0.505X + 27.313 ( r = - 0.634), YN13 = - 0.905X + 46.249(r= -0.619), YN20 = - 1.142X + 61.668 (r= -0.600) during the rewarming period (P ＜0.05). No neurological dysfunction was found in all the patients. Conclusion Hypothermia can prolong the peak latency of SSEP and does not alter the SSEP amplitude.

OBJECTIVETo study the effects of transection of inferior alveolar nerve (IAN) on the healing of mandibular fracture by investigating the changes of inflammatory factors expression, including tumor necrosis factor-alpha (TNF-alpha), interleukin-1 (IL-1) and interleukin-6 (IL-6) in the denervated rabbits' bony callus.

METHODS50 Chinese rabbits were randomly divided into the experimental group and control group, the experimental group underwent mandibular fracture and transection of IAN and the control group underwent mandibular fracture only. The bony callus were collected at 1, 2, 3, 5 and 7 d after operation, respectively. The expression of TNF-alpha, IL-1 and IL-6 in callus was detected by enzyme linked immunosorbent assay (ELISA), and the mRNA of TNF-alpha was detected by reverse transcription-polymerase chain reaction(RT-PCR).

RESULTSIn the experimental group, at the 1st day after operation, the expression of TNF-alpha (75.1%), IL-1 (68.3%) and IL-6 (72.7%) was lower than that in control group (P < 0.05). At the 2nd day, the expression of IL-1 (75.5%) was still lower than that in control group, but the expression of TNF-alpha was higher than that in control group. In the next observation points, all inflammatory factors decreased, and there was no difference between experimental and control groups. In RT-PCR, the detection of TNF-alpha mRNA in the experimental group was lower than that in control group.

CONCLUSIONIn the haematoma of mandibular fracture healing, transection of IAN causes neurohumor decrease, depression and delay of inflammatory reaction. It is unfavorable to fracture healing.

Animals ; Hematoma ; Interleukin-6 ; Mandible ; Mandibular Nerve ; RNA, Messenger ; Rabbits ; Tumor Necrosis Factor-alpha