Human colostrum and milk collected at different times during the first six months of lactation from 301 subjects were tested for the levels of SIgA, IgM, IgG, C3, C4, lactoferrin and lysozyme by the technique of radial immunodiffusion. These kinds of immunoglobulins in colostrum and milk were detected, however the SIgA was highest among immunoglobulins in colostrum, which acounted for 89.8%.The average level of SigA on the first day of postpartum was 3152.5 mg/dl and exceeded those in the serum by 13-fold. It was suggested that breast-feeding may be crucial for the newborns before their mucosal immune system has been established. The average levels of C3 and C4 on the first day of postpartum were 99.7mg/dl and 65.9mg/dl respectively, reaching the normal serum level. Lactoferrin was as high as 1228.7mg/dl in the colostrum of the first day of lactation. The concentration of lysozyme was 944.2ug/ml on the first day of postpartum, which was about 429 times higher than that of cow milk. Using Holder pasteurization (62.5℃, 30 minutes), the SIgA and lysozyme activity of the milk could be reduced by 29.7% and 8.3% respectively, but a lot of anti-infective factors still remained in milk. So pasteurization may be useful for the sterilization of stored human milk.

Objective To investigate the effects of propofol injected into rostral ventromedial medulla (RVM) on nociceptive responses and examine whether GABA_A resceptor is involved in the mechanism. Methods Sixty-four pathogen free SD rats of both sexes aged 2-3 months weighing 250-300 g were randomly divided into 4 groups ( n = 16 each): group I control (group C) ; group Ⅱ propofol (group P) ; group Ⅲ bicuculline (group B) and group Ⅳ B + P (group BP) . The animals were anesthetized with intraperitoneal 1% pentobarbital 50 mg/kg. Their heads were fixed with stereotactic apparatus. An tracar was inserted into RVM for microinjection of propofol and/or bicuculline. The noxious responses were evaluated by hot plate test (response latency was measured) and formalin test (intraplantar injection of 2.0% formalin 100 μl) . Pain was scored (0 = no pain, 3 = severe pain) . Results Both hot plate test and formalin test showed that hyperalgesia was induced by microinjection of propofol into RVM. In hot plate test hyperalgesia induced by injection of propofol (4μg/0.4μl) into RVM was antagonized at 20 min after microinjection of bicuculline (10 ng/0.4μl) into RVM. In formalin test pain scores were significantly lower at 1, 5,10,20,30,40,50 and 60 min after intraplantar formalin injection in group BP than in group P.Conclusion GABA_A receptor in RVM partially mediates propofol-induced hyperalgesia.

Aim To observe the effects of propofol at spinal level on nociceptive response in rats and the possible role of GABA_A receptor.Methods In the praxiology test,Sprague-Dawley(SD) female rats were randomized into groups.Bicuculline and propofol were microinjected into intrathecally(ith).The noxious response was evaluated with hot plate and formalin test.In immunohistochemistry test,Fos-like immunoreactivity(FLI) neurons expressed in spinal dorsal horn(DH) induced by formalin intraplantar injection(sc) of one hindpaw were used as a neuroactive marker to observe the effects of propofol on the noxious transmission in DH.Results In hot-plate test,significant analgesia produced by propofol(10 g?L~(-1)) was antagonized about 81%,55%,81% and 97% at 10,20,30 and 40 min by ith bicuculline(0.01 g?L~(-1),P