[Association between obesity and age at spermarche among Chinese Han boys aged 11-18 years].

OBJECTIVE: To analyze the association between obesity and age at spermarche among Chinese Han boys aged 11-18 years . METHODS: The height, weight and status of the spermarche of Chinese Han boys aged 11-18 years were selected from the data of 2010 National Physical Fitness and Health Surveillance.The body mass index (BMI), prevalence of spermarche in each age group and ages at spermarche by BMI groups were calculated. Chi square test was used to analyze the differences of prevalences of spermarche among the boys with different BMIs across ages. U-test was used to compare the differences of age at spermarche between the boys who were obese and not. RESULTS: In the boys aged 12 and 17 years in urban areas and boys aged 13 years in rural areas, the differences of prevalences of spermarche among the normal weight, overweight and obesity groups were significant (P<0.05). The age at spermarche in the obesity group (13.90 years) was 0.1 years earlier than that in the non-obesity group (14.00 years) (P<0.05). CONCLUSION: Obesity may make the age at spermarche ahead of time.

The protective effect of vitamin E against oxidative damage caused by formaldehyde in the testes of adult rats.

AIM: To investigate the effect of formaldehyde (FA) on testes and the protective effect of vitamin E (VE) against oxidative damage by FA in the testes of adult rats. METHODS: Thirty rats were randomly divided into three groups: (1) control; (2) FA treatment group (FAt); and (3) FAt + VE group. FAt and FAt + VE groups were exposed to FA by inhalation at a concentration of 10 mg/m(3) for 2 weeks. In addition, FAt + VE group were orally administered VE during the 2-week FA treatment. After the treatment, the histopathological and biochemical changes in testes, as well as the quantity and quality of sperm, were observed. RESULTS: The testicular weight, the quantity and quality of sperm, the activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and glutathione (GSH) were significantly decreased whereas the level of malondialdehyde (MDA) was significantly increased in testes of rats in FAt group compared with those in the control group. VE treatment restored these parameters in FAt + VE group. In addition, microscopy with hematoxylin-eosin (HE) staining showed that seminiferous tubules atrophied, seminiferous epithelial cells disintegrated and shed in rats in FAt group and VE treatment significantly improved the testicular structure in FAt + VE group. CONCLUSION: FA destroys the testicular structure and function in adult rats by inducing oxidative stress, and this damage could be partially reversed by VE.

[Effects of programmed cell death on human dental follicle cells and changes of programmed cell death under different hydrostatic pressures].

OBJECTIVE: Tooth eruption requires the presence of the dental follicle (DF) around the unerupted tooth. This study is to investigate programmed cell death on human dental follicle cells and changes of programmed cell death under different hydrostatic pressures: 0, 50 and 100 kPa. METHODS: Human dental follicles from third mandibular molars were surgically removed from adolescents who need for orthodontics treatment after informed content, then trypsinized and cultured. Human dental follicle cells were divided into three groups according to different hydrostatic pressures: 0, 50 and 100 kPa and their programmed cell death were labeled by using TdT-medi-ated-dUTP nick and labeling (TUNEL). RESULTS: Dental follicle cells cultured were elongate shape and exhibited fibroblastic characteristics. Compared with 0 kPa, programmed cell death cells on human dental follicle cells were increased 0.23% and 31.65% under 50 kPa and 100 kPa hydrostatic pressures respectively. 100 kPa group increased significantly (P < 0.01). CONCLUSION: It suggested that programmed cell death occured in human dental follicle cells cultured in vitro and was influenced by different hydrostatic pressures. Hydrostatic pressure may improve tooth erup-tion through dental follicle.

Induction of liver cytochrome P450 1A2 expression by flutamide in rats.

AIM: To investigate the modulation of liver cytochrome P450 1A2 (CYP1A2) expression by giving flutamide to adult rats. METHODS: Rats were given 50, 100, and 200 mg/kg po of flutamide for 2 weeks. Liver CYP1A2 mRNA was measured using reverse transcription-polymerase chain reaction. CYP1A2 protein was detected using immunoblotting. CYP1A2 activity was assayed using high performance liquid chromatography, with caffeine as the CYP1A2 substrate. RESULTS: CYP1A2 mRNA levels after flutamide treatment at 100 mg/kg and 200 mg/kg were, respectively, 1.86 and 3.11-fold higher than those of the control. Correspondingly, CYP1A2 protein increased 1.78 and 2.89-fold and CYP1A2 activity increased approximately 1.65 and 2.83-fold, respectively, relative to controls. Flutamide treatment at 50 mg/kg had no significant effect on CYP1A2 mRNA, protein, or enzyme activity. CONCLUSION: Giving rats flutamide induced liver CYP1A2 expression in a dose-dependent manner.

[Clinical research on unilateral extraction for moderate crowding].

OBJECTIVE: To clinically investigate the results of unilateral extraction in the treatment of special moderate crowding cases. METHODS: 22 patients with harmonic profile and moderate crowding were selected and treated by unilateral extraction with Edgewise technique. The patients crowding was 6 - 9 mm and focused on one side of the arch. 22 patients with moderate crowding were treated by bilateral extraction as control. RESULTS: 22 patients have been treated successfully within 18 months. Crowding was completely resolved. Midline coincidence was basically maintained.Good intercuspation was achieved. There is no significant difference in dental arch symmetry between unilateral extraction and bilateral extraction (P > 0.05). CONCLUSION: Unilateral extraction can be successful in the treatment of special moderate crowding cases.

Effects of huperzine A on liver cytochrome P-450 in rats.

AIM: To predict possible drug interaction and assure safety medication of huperzine A (HupA). METHODS: The effects of HupA on activities and expressions of cytochrome P-450 (CYP) were examined. Liver microsomes and total mRNA were prepared from rats treated orally with 0, 0.1 (pharmacological dose), 1, or 2 mg/kg huperzine A for 2 weeks. Phenobarbital, 3-methylcholanthrene (3-MC), ethanol, and dexamethasone were used as positive controls. Total CYP protein was assayed by carbon monoxide difference spectrum. Activity of isoenzyme was detected with specific probe. Expression of CYP protein and mRNA was analyzed with Western blot and RT-PCR. RESULTS: No changes of isoenzyme expression and catalytic activities were found in rats treated with 0.1 mg/kg huperzine A. Huperzine A 1, 2 mg/kg parallelly increased CYP1A2 activity, protein and mRNA, although they were minor when contrasted with 3-MC. Huperzine A 1, 2 mg/kg got no effects on CYP2C11, CYP2B1/2, 2E1 and 3A. CONCLUSION: Activity and expression of liver CYP isoenzymes were not affected in rats treated with pharmacological dose of HupA, but HupA at toxicological dose may elicit a slight inductive response of CYP1A2. The CYP1A2 induction produced by HupA is related to transcription enhancement.

Acute effects of huperzine A and tacrine on rat liver.

AIM: To observe the acute effects of huperzine A and tacrine on rat liver. METHODS: Changes of liver coefficient, serum biochemistry, and histopathology were detected after single dose. In vitro cytotoxicity was assessed by determining extracellular and intracellular amount of lactate dehydrogenase in cultured hepatocytes. RESULTS: Both huperzine A and tacrine raised liver coefficient and increased serum aspartate aminotransferase and alanine aminotransferase. Tacrine induced liver histopathologic changes. The acute effects of huperzine A on liver could be redressed by atropine, while effects of tacrine on liver could not. Concentration-dependent in vitro cytotoxicity occurred with tacrine, but not with huperzine A. CONCLUSION: The acute effects of huperzine A on rat liver are not related to hepatotoxicity. The acute effects of tacrine on rat liver are related to hepatotoxicity.

Cytotoxicity of flutamide and 2-hydroxyflutamide and their effects on CYP1A2 mRNA in primary rat hepatocytes.

AIM: To compare the cytotoxicity of flutamide and its active metabolite 2-hydroxyflutamide and their effects on cytochrome P-450 1A2 mRNA in primary rat hepatocytes. METHODS: After the isolation of hepatocytes a nd t he primary incubation for 4 h, flutamide and 2-hydroxyflutamide were added respectively to the medium at the concentration of 10, 20, and 50 mg/L and incubated for 8 h. Cytotoxicity of hepatocytes was assessed by Trypan blue exclusion, lactate dehydrogenase (LDH) leakage, percentage of alanine aminotransferase (ALT) or aspartate aminotransferase (AST) release, and reduced glutathione (GSH). The effect of flutamide and 2-flutamide on the CYP1A2 mRNA level was further analyzed by Northern blot. RESULTS: After incubation for 8 h, cell viability was observed by Trypan blue exclusion. The increase of ALT and AST activity and the decrease of glutathione content were also noted at 10, 20, and 50 mg/L of flutamide and 50 mg/L of 2-hydroxyflutamide as compared with normal rat hepatocytes. Induction of CYP1A 2 mRNA were 2-, 5-, and 7.5-fold at 10, 20, and 50 mg/L of flutamide and 3.5-fold at 50 mg/L of 2-hydroxyflutamide. CONCLUSION: Cytotoxicity of flutamide and its effect on CYP1A2 mRNA were stronger than those of its active metabolite 2-hydroxyflutamide in primary rat hepatocytes.

Influence of piperacillin on pharmacokinetics of etimicin in healthy volunteers.

AIM: To investigate the influence of piperacillin on the pharmacokinetics of etimicin. METHODS: Ten healthy male volunteers subjects were administered randomly with 200 mg of etimicin alone or in combination with 2000 mg of piperacillin. After two weeks washout period, the subjects were crossed over to the second regimen. Blood and urinary samples were collected at specified time intervals. Etimicin concentration was analyzed using micro-bioassay method with Bacillus pumillus as the tested strain. Pharmacokinetic para-meters were determined from serum concentration-time data with the 3p87-software package. RESULTS: Maximum serum concentrations of etimicin alone was (21 +/- 5) mg/L compared with (19 +/- 4) mg/L for the combination. The elimination half-lives were (1.9 +/- 0.4) h and (1.9 +/- 0.2) h for etimicin alone and in combination, respectively. The area under the concentration-time curve of etimicin alone was (38 +/- 7) mg . h . L-1 as opposed to (41 +/- 8) mg . h . L-1 in combination. Twelve hours after administration, urinary recovery rates of etimicin were (56 +/- 8) % and (56 +/- 6) % for etimicin alone and with piperacillin, respectively. CONCLUSION: The results indicated that the pharmacokinetics of etimicin was not affected by concurrent administration of piperacillin in healthy male volunteers. No modification in dosing regimen is necessary when two drugs were co-administered.

[Sex-difference on flutamide metabolism in rat liver microsomal cytochrome P450 1A2].

AIM: To assess the sex-difference on flutamide metabolism in rat liver microsomes useing rat cytochrome P450, 1A2, inhibitory monoclonal antibody. METHODS: Liver microsomes were prepared from male or female rats. Protein concentration and total cytochrome P450 content were determined. Incubation mixture included liver microsomes (1.0 nmol.L-1), reduced form of nicotinamide adenine dinucleotide phosphate (NADPH, 0.1 nmol.L-1), CYP1A2 (1:400) and flutamide (2 mg.L-1). The incubation time was 30 min. The concentration of flutamide and its major metabolite 2-hydroxyflutamide were analyzed by reverse high-performance liquid chromatography. The mobile phase was a mixture of methanol-acetonitrile-water-diethylether (40:20:35:1) with methyltestosterone as internal standard. The detection wavelength was 234 nm. The reaction mixture was extracted with acetic ether 4 mL. Sex-difference on flutamide metabolism was expressed as the difference between the concentration ratio of 2-hydroxyflutamide to flutamide in male and female rat liver microsomes. RESULTS: The recoveries of flutamide and 2-hydroxyflutamide for the proposed method were more than 75%. The formation of 2-hydroxyflutamide from flutamide was inhibited by CYP1A2 antibodies (1:400) in male and female rat liver microsome for 30 min of incubation time, but the inhibition of flutamide metabolism in female rat was stronger than that in male. The concentration ratios of 2-hydroxyflutamide to flutamide were (1.5 +/- 0.6) and (0.9 +/- 0.4) in male and female rat liver microsomes, respectively (P < 0.01). CONCLUSION: The results indicate that the activity of male rat CYP1A2 is higher than that of the female rat. There is difference in sex-related rate of flutamide metabolism in rat liver microsomes.