Acute Disease ; Adult ; Aged ; Female ; Humans ; Hydrogen Sulfide ; poisoning ; Male ; Middle Aged ; Occupational Diseases ; Young Adult

Objective To evaluate the effect of propofol on noise-induced hearing loss in guinea pigs.Methods Forty-eight healthy adult male guinea pigs,aged 3 months,weighing 400-500 g,were randomly divided into 4 groups (n =12 each) using a random number table:control grotup (C group),propofol group (P group),noise-induced hearing loss group (N group),and propofol + noise-induced hearing loss group (P + N group).A loading dose of propofol 5 mg/kg was infused intravenously over 5 min,followed by infusion at 20 mg· kg-1 · h-1 for 115 min in P and P + N groups,while the equal volume of normal saline was given in N group.N and P+ N groups were exposed to the noise of 4 kHz center frequency and 118-122 dB sound pressure level for 120 min.Distortion product otoacoustic emission (DPOAE) was measured before noise exposure (T1) and at 1 h after the end of noise exposure (T2) and the amplitudes were recorded at the frequencies of 2,4,6 and 8 kHz.After the second measurement of DPOAE,all the animals were sacrificed and organs of Corti were harvested for determination of cochlear 8-isoprostaglandin F(2alpha) (8-iso-PGF2α) content (by ELISA assay) and out hair cell (OHC) count.The rate of OHC lesions was calculated.Results The DPOAE amplitude was significantly lower at frequencies of 4,6 and 8 kHz at T2 than at T1 in N and P + N groups (P ＜ 0.05).Compared with C group,the DPOAE amplitude was significantly decreased at frequencies of 4,6 and 8 kHz at T2,while the cochlear 8-isoPGF2α content and rate of OHC lesions were increased in N and P + N groups (P ＜ 0.05).Compared with N group,the DPOAE amplitude was significantly increased at frequencies of 4,6 and 8 kHz at T2,while the cochlear 8-iso-PGF2α content and rate of OHC lesion were decreased in P + N group (P ＜ 0.05).Conclusion Propofol can reduce noise-induced hearing loss in guinea pigs possibility through decreasing oxidative stress response-induced damage to cochlear OHCs.

Objective To evaluate the effect of dexmedetomidine on noise-induced hearing loss in guinea pigs.Methods Twenty-four adult male guinea pigs,aged 3 months,weighing 400-500 g,were randomly divided into 3 groups (n =8 each) using a random number table:dexmedetomdine group (group D),noise-induced hearing loss group (group N) and dexmedetomidine + noise-induced hearing loss group (group DN).A loading dose of dexmedetomidine 5 μg/kg was infused over 5 min,followed by 135 min of infusion at a rate of 10 μg· kg-1 · h-1.The equal volume of normal saline was infused in group N.Groups N and DN were exposed to noise of 4 kHz center frequency and 118-122 dB SPL for 120 min starting from 20 min of administration.Mean arterial pressure (MAP) and cochlear blood flow (COBF) were recorded before administration and every 5 min during drug administration.The changing rate of COBF was calculated.Arterial blood samples were collected for determination of plasma concentration of noradrenaline (NE) by high performance liquid chromatography at 20 and 140 min of administration.Auditory brainstem response (ABR) threshold was recorded before administration and at 1 and 72 h and 10 days after the end of administration.Results Compared with group N,MAP was significantly decreased,the changing rate of COBF was increased at 5-10 min and 30-140 min of administration,ABR threshold was decreased at 1 and 72 h and 10 days after the end of administration,and the plasma concentration of NE was decreased at 140 min of administration in D + N group (P ＜ 0.05).Conclusion Dexmedetomidine can attenuate noise-induced hearing loss in guinea pigs possibly through inhibiting activation of sympathetic nerves and increasing COBF.

Objective To evaluate the effects of different doses of propofol or isoflurane on the cochlear blood flow (CBF) in guinea pigs.Methods Fifty-four adult male guinea pigs,aged 3 months,weighing 400-500 g,were randomly divided into 6 groups (n =9 each).In P1,P2 and P3 groups,propofol was infused for 115 min at 10,20 and 40 mg· kg-1 · h-1,respectively,after a loading dose of 5 mg/kg was injected over 5 min.In S1,S2 and S3 groups,isoflurane was inhaled for 120 min with end-tidal concentrations of 1％,2％ and 3 ％,respectively.Mean arterial pressure and CBF were recorded before administration (baseline,T1) and during the period of drug administration.Distortion product otoacoustic emission (DPOAE) was measured at T1,at the end of administration (T2) and 1 h after administration (T3).Five animals in each group were sacrificed and organs of Corti were harvested for observation of morphology of out hair cells by scanning electron microscopy.Results Propofol decreased MAP and increased CBF and DPOAE amplitude in a dose-dependent manner.Isoflurane decreased MAP and CBF in a dose-dependent manner.1％ isoflurane increased DPOAE amplitude,however,2％ and 3％ isoflurane decreased it and caused damage to out hair cells.Conclusion Propofol induces an increase in CBF in guinea pigs,while high concentration of isoflurane induces a decrease in CBF.Isoflurane inhibits CBF autoregulation,which makes CBF more sensitive to perfusion pressure,thus causing damage to hearing function.This is the reason why high concentration of isoflurane induces a decrease in CBF.

Drugs, Chinese Herbal ; therapeutic use ; Gonadal Steroid Hormones ; Humans ; Medicine, Chinese Traditional ; Phytotherapy ; Sjogren's Syndrome ; etiology ; therapy

Objective To evaluate the correlation between periodontitis and life style. Methods By using randomized cluster sampling method,2990 health check-up receivers were enrolled in this cross sectional survey from September 2007 to September 2008. The participants were requested to fill in a questionnaire to assess community periodontal index and synthesis grades. Multiple linear regression was used for data analysis. Results Gender (P = 0. 000) , age (P = 0. 000 ) , educational level ( P = 0. 001) , smoking (P = 0.011 ) and duration of teeth brush ( P = 0.026 ) were positively correlated with periodontitis. However, periodontitis showed no relationship with alcohol consumption, food intake, daily activity,frequency of teeth brush, periodontal bleeding. Conclusion Periodontitis is a condition with multiple risk factors. Improving life style may help to prevent general population from periodontitis.

Objective To evaluate the effect of isoflurane anesthesia on noise-induced hearing loss in guinea pigs.Methods Forty-eight healthy adult male guinea pigs,aged 3 months,weighing 400-500 g,were randomly divided into 4 groups (n =12 each) using a random number table:control group (C group),isoflurane group (I group),noise-induced hearing loss group (N group),and isoflurane + noise-induced hearing loss group (I + N group).Isoflurane was inhaled for 140 min at a concentration of 1％ in I and I + N groups.N and I + N groups were exposed to the noise of 4 kHz center frequency and 118-122 dB sound pressure level for 120 min starting from 20 min after administration.Mean arterial pressure (MAP) was recorded at 10,40,70,100 and 120 min of exposure to noise and cochlear blood flow (CoBF) was recorded before administration and at 10,40,70,100 and 120 min of exposure to noise.Auditory brainstem response (ABR) threshold was recorded before administration and at 1 h,72 h,and 10 days after the end of exposure to noise.Arterial blood samples were obtained and the plasma noradrenaline (NE) concentration was detected by HPLC before exposure to noise and immediately after the end of exposure to noise.Results Compared with group C,MAP and the change rate of CoBF were significantly decreased,and the plasma NE concentration was increased immediately after the end of exposure to noise in I group,and MAP was increased,the change rate of CoBF was decreased,and the plasma NE concentration immediately after the end of exposure,and ABR threshold after the end of exposure were increased in N and I + N groups.Compared with N group,MAP was significantly decreased,the change rate of CoBF was increased,the plasma NE concentration immediately after the end of exposure,and ABR threshold at 1 and 72 h after the end of exposure were increased,and no significant was found in ABR threshold at 10 days after the end of exposure in I + N group.Conclusion Isoflurane anesthesia exerts temporary but not permanent protective effects against noise-induced hearing loss in guinea pigs and partial inhibition of activation of sympathetic nerve and increased CoBF may be involved in the mechanism.

Adult ; Aged ; Copper ; Hearing Loss, Noise-Induced ; epidemiology ; Humans ; Male ; Middle Aged ; Mining ; Occupational Diseases ; epidemiology

Amniotic Fluid ; Gastrointestinal Hemorrhage ; etiology ; Humans ; Infant, Newborn ; Vitamin K Deficiency ; complications

Transforming growth factor-?_1 (TGF-?_) mRNA or protein expression in renal cortex of diabetic rats was assessed by real-time quantitative RT-PCR with SYBR Green,immunohistochemistry or Western blot.After melatonin treatment,the expressions of TGF-?_1 mRNA and protein were decreased,suggesting that beneficial effect of melatonin may result from its antioxidative property and inhibiting TGF-?_1 expressions.