Mechanism of intermittent and persistent noise exposure-induced anxiety and depression-like behavior in rats / 中国职业医学

OBJECTIVE: To investigate the effects and mechanisms of intermittent and persistent noise exposure-induced anxiety and depression-like behavior in rats. METHODS: The specific pathogen free male SD rats were randomly divided into control group, four times/day intermittent noise exposure group, two times/day intermittent noise exposure group and persistent noise exposure group, with 15 rats in each group. The rats in the control group were housed in natural environment(background noise ≤50 dB), and the rats in other three exposure groups were exposed to noise with intensity of(95±2) dB of 20 to 20 000 Hz noise for four hours per day for 14 days; rats in the four times/day intermittent noise exposure group entered a five-hour quiet period every one hours of noise exposure, four times/day; rats in the two times/day intermittent noise exposure group entered a 10-hour quiet period every two hours of noise exposure, two times/day; rats in the persistent noise exposure group entered a 20-hour quiet period every four hours of noise exposure. After exposure, anxiety like behavior was evaluated by open field test and elevated cross maze test. The depression like behavior was evaluated by sugar preference test and forced swimming test. The pathological changes of neurons in the hippocampus were observed by hematoxylin-eosin(HE) staining, and the ultrastructural changes of hippocampal tissues were observed by transmission electron microscope. Chemiluminescence and colorimetry were used to detect the levels of reactive oxygen species(ROS), malondialdehyde, glutathione(GSH) and the activity of superoxide dismutase(SOD). RESULTS: In the behavioral experiment, the percentage of exercise time in the central area decreased in the three noise exposure groups(all P<0.01). The exercise distance in the central area and sugar preference index decreased in the persistent noise exposure group(both P<0.01). The percentage of open arm exercise time and open arm exercise distance decreased in the two times/day intermittent noise exposure group and persistent noise exposure group compared with the control group(all P<0.01). The open arm distance of rats in the persistent noise exposure group were lower than those in the four times/day intermittent noise exposure group(P<0.05), while the immobility time was longer than in control group and the four times/day intermittent noise exposure group(both P<0.05). The HE staining showed that the neuronal spacing in CA1 area of the hippocampus of rats was significantly widened, and the pyramidal cells showed degeneration and necrosis in the persistent noise exposure group. There was no obvious necrosis found in the neurons of the other three groups. The ultrastructure of neurons showed that most mitochondria of cells in the hippocampus of rats in the two times/day intermittent noise exposure group were swollen. In the persistent noise exposure group, some neurons of the hippocampus of rats were necrotic, the cell membrane was discontinuous, the mitochondria were swollen, and the cristae were broken, dissolved or even disappeared. The mitochondrial structure of the hippocampus of rats in the other two groups was normal. The activity of SOD in the hippocampus of rats decreased in the four times/day intermittent noise exposure group(P<0.05), and the activity of SOD and the level of GSH in the hippocampus of rats decreased in the two times/day intermittent noise exposure group(both P<0.05), compared with the control group. The level of ROS and malondialdehyde in the hippocampus of rats in the persistent noise exposure group increased(all P<0.05), while the SOD activity and GSH level decreased(all P<0.05), compared with the other three groups. CONCLUSION: Intermittent noise exposure causes less anxiety and depression-like changes in rats than persistent noise exposure. Noise may cause anxiety and depression in rats through oxidative stress pathways.

Pharmacokinetics of SN-38 in rats and tissue distribution of 7-ethyl-10-hydroxycamptothecin in mice after intravenous injection of irinotecan hydrochloride nanoparticles / 药学学报

The paper reported an investigation of the pharmacokinetics of SN-38 (7-ethyl-10-hydroxy-camptothecin) in rats and the tissue distribution in mice after injection of irinotecan hydrochloride nanoparticles (CPT-11) via tail veins. An LC-MS/MS method was established to determine the concentrations of SN-38 in whole blood of rats and in different tissues of mice. The pharmacokinetics and tissue distribution of SN-38 were compared after the intravenous injection of CPT-11 NPs and CPT-11 solution. Compared with irinotecan solution, the elimination half-life of SN-38 was prolonged from 2.17 h to 2.67 h after the intravenous injection of CPT-11 NPs, but its AUC had little change. After the injection of CPT-11 NPs in mice, over time, the concentrations of CPT-11-metabolized SN-38 in CPT-11 NPs were significantly higher in the whole blood, colon and lungs than those in CPT-11 solution, followed by in the spleen and liver, but those in the heart and brain had no change. However, the amount of SN-38 in the kidneys was reduced with time. CPT-11 NPs could prolong SN-38's (one of its metabolites) blood circulation time in rats and significantly increased the concentration of CPT-11-metabolized SN-38 in the whole blood, colon and lungs of mice. CPT-11 NPs made SN-38 efficiently target-bind to the colon and lungs of mice.

To explore the safety testing evaluation index of breast-feeding by hepatitis B-positive mothers / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>To explore the safety testing evaluation index of breast-feeding by hepatitis B-positive mothers.</p><p><b>METHODS</b>HBV DNA from serum and breast milk of 252 hepatitis B-positive mothers were detected with the real-time quantitative PCR.</p><p><b>RESULTS</b>The total positive rate of HBV DNA in serum had no difference with that in breast milk in hepatitis B-positive mothers (P > 0.05). The positive rate of HBV DNA in serum and breast milk of positive HBeAg were significantly higher than that of hepatitis B-positive mothers with negative HBeAg (P < 0.01).</p><p><b>CONCLUSION</b>To detecte HBeAg and HBV DNA in serum and breast milk have important significance for guiding of breast feeding of hepatitis B-positive mothers.</p>

The modification of apoptosis correlated gene, protein and protein activity in rat hippocampus induced by benzoa pyrene sub-chronic exposure / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To observe the effects of subchronic exposure to benzo[a]pyrene (B[a]P) on the mRNA and protein expression levels of apoptosis-related genes (bax, bcl-2, caspase-3, caspase-6, and caspase-9) and the activities of Caspase-3, Caspase-6, and Caspase-9 in the hippocampal neurons of rats and to investigate the neurotoxic mechanism by which B[a]P induces the apoptosis of neurons.</p><p><b>METHODS</b>Fifty-two healthy SD rat were randomly divided into five groups according to preliminary neurobehavioral test results: blank control group, solvent control group, and 1.0, 2.5, and 6.25 mg/kg B[a]P exposure groups; the rats in exposure groups were intraperitoneally injected with B[a]P every other day for 90 days. The Morris water maze was used to test the learning and memory ability of rats; flow cytometry was used to measure the apoptosis ratio of hippocampal neurons; real-time quantitative PCR and Western blot were used to measure the mRNA and protein expression levels of apoptosis-related genes; spectrophotometry was used to measure the activities of their en-coded proteins.</p><p><b>RESULTS</b>Compared with the blank control group, solvent control group, and 1.0 mg/kg B[a]P exposure group, the 2.5 and 6.25 mg/kg B[a]P exposure groups hada significantly longer mean escape latency period (P < 0.05) and a significantly increased number of times of platform crossing (P < 0.05), and the 6.25 mg/kg B[a]P exposure group had significantly lower length and percentage of time spent in the platform quadrant (P < 0.05). The early apoptosis ratio rose as the dose of B[a]P increased (P trend < 0.05); the early apoptosis ratios of 1.0, 2.5, and 6.25 mg/kg B[a]P exposure groups were significantly higher than those of blank control group and solvent control group (P < 0.05). Compared with the blank control group, solvent control group, and 1.0 and 2.5 mg/kg B[a]P exposure groups, the 6.25 mg/kg B[a]P exposure group had significantly increased Bax expression (P < 0.05) and significantly decreased Bcl-2 expression and Bcl-2/Bax ratio (P < 0.05). The 2.5 and 6.25 mg/kg B[a]P exposure groups had significantly higher expression levels of Caspase-3 and Caspase-6 than the blank control group, solvent control group, and 1.0 mg/kg B[a]P exposure group (P < 0.05). The activities of Caspase-3, Caspase-6, and Caspase-9 were significantly higher in the 2.5 and 6.25 mg/kg B[a]P exposure groups than in the blank control group and solvent control group (P < 0.05). There was a positive correlation between the activities of Caspase-3, Caspase-6, and Caspase-9 and early apoptosis ratio of hippocampal neurons in rats (r = 0.793, P = 0.019; r = 0.886, P = 0.006; r = 0.773, P = 0.025). There were no significant differences in the mRNA expression of Bax, Bcl-2, Caspase-3, Caspase-6, and Caspase-9 among these groups (P > 0.05).</p><p><b>CONCLUSION</b>Subchronic exposure to B[a]P can induce apoptosis of hippocampal neurons; its mechanism may be related to the fact that B[a]P can induce upregulated expression of Bax, inhibit expression of Bcl-2, lead to decrease in Bcl-2/Bax ratio, induce upregulated expression of Caspase-3 and Caspase-6, and cause increase in the activities of Caspase-3, Caspase-6, and Caspase-9.</p>

Pharmacokinetic interaction of pioglitazone hydrochloride and atorvastatin calcium in Beagle dogs / 药学学报

The object of this study is to investigate the pharmacokinetic interaction of pioglitazone hydrochloride and atorvastatin calcium in healthy adult Beagle dogs following single and multiple oral dose administration. A randomized, cross-over study was conducted with nine healthy adult Beagle dogs assigned to three groups. Each group was arranged to take atorvastatin calcium (A), pioglitazone hydrochloride (B), atorvastatin calcium and pioglitazone hydrochloride (C) orally in the first period, to take B, C, A in the second period, and to take C, A, B in the third period for 6 days respectively. The blood samples were collected at the first and the sixth day after the administration, plasma drug concentrations were determined by LC-MS/MS, a one-week wash-out period was needed between each period. The pharmacokinetic parameters of drug combination group and the drug alone group were calculated by statistical moment method, calculation of C(max) and AUC(0-t) was done by using 90% confidence interval method of the bioequivalence and bioavailability degree module DAS 3.2.1 software statistics. Compared with the separate administration, the main pharmacokinetic parameters (C(max) and AUC(0-t)) of joint use of pioglitazone hydrochloride and atorvastatin calcium within 90% confidence intervals for bioequivalence statistics were unqualified, the mean t(max) with standard deviation used paired Wilcoxon test resulted P > 0.05. There was no significant difference within t1/2, CL(int), MRT, V/F. Pioglitazone hydrochloride and atorvastatin calcium had pharmacokinetic interaction in healthy adult Beagle dogs.

Pharmacokinetics and tissue distribution of irinotecan hydrochloride nanoparticles / 药学学报

To investigate the pharmacokinetics of irinotecan hydrochloride (CPT-11) in rats and the tissue distribution of CPT-11 in mice after injection of irinotecan hydrochloride nanoparticles (CPT-11 NPs) via tail veins, separately, a LC-MS/MS method was established to determine the concentration of CPT-11 in whole blood of rats and in different tissues of mice. The pharmacokinetics and tissue distribution of CPT-11 were compared after the intravenous injection of CPT-11 NPs and CPT-11 solution. Compared with CPT-11 solution, the elimination half-life of CPT-11 was prolonged from 2.28 h to 3.95 h after the intravenous injection of CPT-11 NPs, and its AUC was 1.47 times than that of CPT-11 solution. After the injection of CPT-11 NPs in mice, the concentrations of CPT-11 loaded in CPT-11 NPs were significantly higher in the whole blood, colon and lungs than those in CPT-11 solution, but lower in the spleen, liver, kidney and heart, but the least in brain. CPT-11 NPs could improve CPT-11 's AUC, and help CPT-11 to reach long circulation activity.

The more efficacious acupoints of Zusanli and Sanyinjiao than that of non-acupoints on bone mass in osteopenic ovariectomized rats / 中国结合医学杂志

<p><b>OBJECTIVE</b>To clarify whether the acupoints of Zusanli (ST36) and Sanyinjiao (SP6) have specific actions other than non-acupoints to bone.</p><p><b>METHODS</b>Forty Sprague-Dawley female rats were divided into five groups: Sham operated (sham) group; Ovariectomized (OVX, model) group; non-acupuncture group; OVX, needling on Zusanli and Sanyinjiao (Acp-A) group; OVX, needling on the reverse sides of Zusanli and Sanyinjiao (Acp-B) group; OVX, periostineal stimulation on the same height as points of Zusanli and Sanyinjiao (Acp-C) group. The experiment was continued for 23 weeks and then all animals were sacrificed.</p><p><b>RESULTS</b>OVX had a significantly higher body weight and lower bone mineral density (BMD) on the lumbar vertebrae, total femora and tibiae than sham rats, however, Acp-A showed a higher BMD compared with the other OVX groups. On the other hand, bone weights, bone strength and bone morphometry such as trabecular volume, trabecular separation, labeled width and bone formation rate also showed the same improvements in Acp-A as compared to the other OVX rats.</p><p><b>CONCLUSION</b>The stimulation on Zusanli and Sanyinjiao specifically prevented the development of osteopenic rats compared with non-acupoints.</p>

Study of Bilingual Teaching for Medical Microbiology / 微生物学通报

Bilingual teaching is adapted to the development of higher education in china.Based on actual fact of college,teaching mode,evaluation and effect of bilingual teaching on medical microbiology were studied,which started with necessity of bilingual teaching to use original edition teaching material in English. The result would provide some gist to choice the suitable pattern of bilingual teaching for other subject of our college.