Research progress on the regulation of mammalian energy metabolism by the circadian clock system and gut microbiota / 生理学报

The mammalian internal circadian clock system has been evolved to adapt to the diurnal changes in the internal and external environment of the organism to regulate diverse physiological functions, such as the sleep-wake cycle and feeding rhythm, thereby coordinating the rhythmic changes of energy demand and nutrition supply in each diurnal cycle. The circadian clock regulates glucose metabolism, lipid metabolism, and hormones secretion in diverse tissues and organs, including the liver, skeletal muscle, pancreas, heart, and vessels. As a special "organ" of the host, the gut microbiota, together with the intestinal microenvironment (tissues, cells, and metabolites) in a co-evolutionary process, constitutes a micro-ecosystem and plays an important role in the process of nutrient digestion and absorption in the intestine of the host. In recent years, accumulating evidence indicates that the compositions, quantities, colonization, and functional activities of the gut microbiota exhibit significant circadian variations, which are closely related to the changes of various physiological functions under the regulation of host circadian clock system. In addition, several studies have shown that the gut microbiota can produce many important metabolites such as the short-chain fatty acids through the degradation of indigestive dietary fibers. A portion of gut microbiota-derived metabolites can regulate the circadian clock system and metabolism of the host. This article mainly discusses the interaction between the host circadian clock system and the gut microbiota, and highlights its influence on energy metabolism of the host, providing a novel clues and thought for the prevention and treatment of metabolic diseases.

Influence of 1, 2-dichloroethane on open field behavior and levels of neurotransmitters in brain of mice / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To explore the effects of 1,2-dichloroethane (1,2-DCE) on the behavior and the brain neurotransmitter levels in mice.</p><p><b>METHODS</b>Thirty mice were randomly divided into four groups, which were control group and groups of low, middle and high exposure (225, 450 and 900 mg/m3) to 1,2-DCE for 10 days (3.5 h a day) by inhalation. After the last exposure, the open field test was performed immediately. After exposure all mice were killed and the brain tissues were taken up rapidly. The levels of aspartate (Asp), glutamate (Glu) and gamma-aminobutyric acid (GABA) in the brain were detected by high performance liquid chromatography (HPLC).</p><p><b>RESULTS</b>Levels of Asp and Glu in all exposure groups increased with doses. As compared to the control group, levels of Glu in all exposure groups increased significantly (P < 0.05). Levels of GABA in the low exposure group were significantly lower than those in control group, but those in the high exposure group were significantly higher than those in control group. The results of the open field test showed that effect of low exposure to 1,2-DCE on the behavior was stimulant, but the high exposure to 1,2-DCE inhibited behavior of exploration, excitement and sport.</p><p><b>CONCLUSIONS</b>Subacute exposure to 1,2-DCE could result in the change of amino acid neurotransmitter content and ratio in the brain, thereby change the behavior of mice appeared, which might be the mechanism of neurotoxicity caused by 1,2-DCE in part.</p>

Dynamic analysis of Ca2+ level during bovine oocytes maturation and early embryonic development

Mammalian oocyte maturation and early embryo development processes are Ca(2+)-dependent. In this study, we used confocal microscopy to investigate the distribution pattern of Ca2+ and its dynamic changes in the processes of bovine oocytes maturation, in vitro fertilization (IVF), parthenogenetic activation (PA) and somatic cell nuclear transfer (SCNT) embryo development. During the germinal vesicle (GV) and GV breakdown stage, Ca2+ was distributed in the cortical ooplasm and throughout the oocytes from the MI to MII stage. In IVF embryos, Ca2+ was distributed in the cortical ooplasm before the formation of the pronucleus. In 4-8 cell embryos and morulas, Ca2+ was present throughout the blastomere. In PA embryos, Ca2+ was distributed throughout the blastomere at 48 h, similar to in the 4-cell and 8-cell phase and the morula. At 6 h after activation, there was almost no distribution of Ca2+ in the SCNT embryos. However, Ca2+ was distributed in the donor nucleus at 10 h and it was distributed throughout the blastomere in the 2-8 cell embryos. In this study, Ca2+ showed significant fluctuations with regularity of IVF and SCNT groups, but PA did not. Systematic investigation of the Ca2+ location and distribution changes during oocyte maturation and early embryo development processes should facilitate a better understanding of the mechanisms involved in oocyte maturation, reconstructed embryo activation and development, ultimately improving the reconstructed embryo development rate.

Metabolism and distribution of arsenic in offspring rats after exposure to arsenic via drinking water / 中国地方病学杂志

Objective To observe the metabolism and distribution of arsenic in liver and brain of offspring rata by exposure to arsenic of pregnant rats or lactation dams and weaned pups,and explore if arsenic could penetrate the placental barrier,lactation barrier and blood brain barrier. Methods The Wistar female rots were randomly divided into four groups according to body weights,12 in each group,and were fed with drinking water that contained arsenic(NaAsO_2) 0,10,50,100 mg/L beginning from the gestafional day 6 until pups 42 days old. Pups were separately sacrificed on postnatal day(PND) 0,15,28,42. Arsenic in liver and brain of offspring rots and in breast milk was examined by atomic absorption speetrophotometer with an arsenic speeiation pretreatment system. Results Concentration of iAs,MMA,DMA of brain in 50,100 mg/L groups were higher than that of 0 mg/L group[0,0,0,(7.3±6.6),0,(44.2±27.4)ng/g]on PND 0,42[iAs: (120.0±46.0),(195.5±125.3),(216.5±278.4),(176.6±151.8) ng/g; M MA: (47.2±18.1),(199.6±389.1),(47.4±55.2),(82.7±79.2) ng/g; DMA: (984.3±377.4),(2222.1±1433.2),(998.1±368.3),(1781.3±715.7)ng/g,all P < 0.05]. Concentration of DMA of brain in 50,100 mg/L groups were higher than that of 0 mg/L group[(13.9±18.1),(50.6±98.3)ng/g]on PND 15,28 [(270.3±73.1),(323.9±72.7),(758.7±245.9),(1020.6±383.6) ng/g,all P < 0.05]. Concentration of iAs,DMA of liver in 10,50,100 mg/L groups were higher than that of 0 mg/L group [(1.4±3.5),(49.7± 47.1),0,(100.4±30.2)ng/g]on PND 28,42 [iAs: (37.5±28.1),(268.8±246.4),(307.2±339.9),(15.4±9.4),(479.1±161.1),(408.4±51.9)ng/g;DMA: (594.5±148.8),(3181.9±519.0),(4834.2±2568.4),(1061.8± 85.2),(3697.1±553.7),(4120.0±732.8) ng/g,all P < 0.05]. Concentration of DMA of liver in 10,50,100 mg/L groups were higher than that of 0 mg/L group[(13.2±20.5)ng/g]on PND 15[(182.0±60,2),(637.6±90.0),(1458.7±196.3)ng/g,all P < 0.05]. Concentration of arsenicals of liver and brain showed a dose-dependent increase. The concentrations of DMA of breast milk in 50,100 mg/L groups were also higher than that of 0 mg/L group[(9.8±13.4),0 ng/g]on PND 0,15 [(182.3±85.9),(372.2±203.9),(124.2±33.1),(244.4±196.5)ng/g,all P < 0.05]. In the analysis of the change of arsenic on different postnatal day,we found the concentration of iAs,MMA,DMA,TMA in liver and brain of pups all decreased on postnatal day 15,and was lower than that on PND 0,28 and 42. Conclusions The distribution of arsenic and methyl-metabolism in liver and brain of pups is related with arsenic exposure dose. Arsenic can penetrate the placenta and blood brain barrier easily and lactation can hinder arsenic intake in some extent.

Determination and evaluation of arsenic speciation and glutathione level in lever and blood of mice subchronically exposed to inorganic arsenic / 中国地方病学杂志

Objective To explore the distribution of arsenic speciafion and to estimate the effect of arsenic on glutathione(GSH)levels in the blood and liver of mice exposed to different concentrations of inorganic AsⅢ through drinking water.Methods Mice drank water containing arsenite at concentrations of iAsⅢ of 0(contr01),25,50,100 ms/L for 6 weeks.Blood and liver were sampled to asses$the levels of inorganic arsenic(iAs),monomethylarsenic acid(MMA),dimethylarsenic acid(DMA)by the method of hydride generation trapping and ultra-hypothermia coupled with atomic absorption spectrometry,and the level of GSH by the method of 5,5'-Dithio-bis (2-Nitrobenzoic acid).Results Leveh of iAs.MMA and DMA in blood and in liver increased along with the increase of iAs concentrations in drinking water.Primary methylated index(PMI)and secondary methylation index (SMI)of liver and blood were significantly higher in exposed groups than those in control group(P＜0.05).SMI of liver in 50 mg/L exposed group[(50.45±2.94)%]was significantly higher than those in 25 mg/L and 100 mg/Lgroups[(41.68±7.09)%and(41.19±8.87)%,respectively],the difference being statistically significant(P＜0.05).The ratio of iAs.MMA and DMA in blood and liver in exposed group were 2:3:5 and 4:3:3,the percentage of level of organic arsenic(MMA+DMA)were 80%and 60%.GSH in blood and liver in exposed group decreased along with iAs concentrations in drinking water and had significant differences compared with those in control group (P＜0.05).However,levels of GSH in liver and blood did not differ significantly between exposed groups and control group(P＞0.05).Conclusions Membolism of iAs in liver is maximized when the iAs concentrations in drinking water increases to a certain level.However,the percentage of arsenic speciation in blood is different from that in liver,suggesting that other organs and tissues may be capable of methylation of inorganic arsenic.The level of GSH in liver and blood in mice is a good mark tO reflect the toxicity of arsenic.

Effect of glutathione and sodium selenite on the metabolism of arsenic in mice exposed to arsenic through drinking water / 中华预防医学杂志

<p><b>OBJECTIVE</b>To explore the effect of glutathione (GSH) and sodium selenite on the metabolism of arsenic in the liver, kidney and blood of mice exposed to iAsIII through drinking water.</p><p><b>METHODS</b>The mice were randomly divided into control, arsenic, GSH and sodium selenite group, respectively. And each group had eight mice and the mice were exposed to 50 mg/L arsenite by drinking water for 4 weeks. Mice were intraperitoneally injected with GSH (600 mg/kg) and sodium selenite (1 mg/kg) for seven days from the beginning of the fourth week. At the end of the fourth week, liver, kidney and blood were sampled to assess the concentrations of inorganic arsenic (iAs), monomethylarsenic acid (MMA), dimethylarsenic acid (DMA) by hydride generation trapping by ultra-hypothermia coupled with atomic absorption spectrometry.</p><p><b>RESULTS</b>The liver DMA (233.76 +/- 60.63 ng/g) concentration in GSH group was significantly higher than the arsenic group (218.36 +/- 42.71 ng/g). The concentration of DMA (88.52 +/- 30.86 ng/g) and total arsenic (TAs) (162.32 +/- 49.45 ng/g) in blood of GSH group was significantly higher than those [(45.32 +/- 12.19 ng/g), (108.51 +/- 18.00 ng/g), respectively] of arsenic groups(q values were 3.06, 6.40, 10.72 respectively, P < 0.05). The primary methylated index (PMI) (0.65 +/- 0.050) and secondary methylated index (SMI) (0.55 +/- 0.050) in liver sample of GSH group were significantly higher than those (0.58 +/- 0.056, 0.44 +/- 0. 093) in arsenic group. In blood samples, the PMI (0.85 +/- 0.066) in GSH group was significantly higher than that (0.54 +/- 0.113) in arsenic group (q values were 3.75, 5.26, 4.21 respectively, P < 0.05). However, no significant difference was identified between sodium selenite and arsenic groups in liver, kidney or blood samples. And no significant difference was detected in kidney samples among all arsenic exposing groups.</p><p><b>CONCLUSION</b>Exogenous GSH could promote the methylated metabolism of iAsIII, but sodium selenite showed no significant effects.</p>

Treatment of meniscal injuries of knee joints by arthroscopy / 中国基层医药

Objective To assess the effectiveness of treatment of meniscal injuries of knee joints by arthroscopy.Methods 33 patients 35 joints were followed up and the parts,types and treatment under arthroscopy were analysed.Results 33 patients were followed up from six months to six years,the mean preoperative Lysholm score was 60.5 points,and the mean postoperative one was 86.7 points.Conclusion The advantage of treating meniscal injuries by arthroscopy was the result of correct examination and little wound of arthroscopy operation,and arthroscopic repair or partial menisectomy could effectively restore the function of the injured knee.

Effects of sodium arsenite on catalase in human keratinocytes / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To evaluate the effects of sodium arsenite on the activity, the mRNA and the protein expression of CAT in human keratinocyte cell line (HaCaT).</p><p><b>METHODS</b>The activity of catalase (CAT) was detected by ultraviolet direct velocity assay. RT-PCR was used to detect the mRNA expression of CAT and Western blotting was conducted to detect the protein expression of CAT.</p><p><b>RESULTS</b>If the cells were treated with higher than 5.0 micromol/L sodium arsenite, the activity, mRNA and protein expression of CAT were decreased significantly and in a dosage dependent fashion (P < 0.05).</p><p><b>CONCLUSION</b>CAT is inhibited by sodium arsenite in the transcription, translation and activity levels.</p>

Effects of fluoride on proliferation and differentiation of rat osteoblasts in vitro and the antagonistic action of vitamin C / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To study the effects of fluoride on the proliferation and differentiation of osteoblasts in sucking rats and the antagonism of vitamin Cin vitro.</p><p><b>METHODS</b>The enzyme digesting method was used to isolate the rat osteoblasts; the proliferative response was determined by the percents of reduced alamarBlue; the activity of alkaline phosphatase (ALP) was measured by ELISA method.</p><p><b>RESULTS</b>The proliferation of sucking rat osteoblasts was increased at 0.10 - 1.00 mmol/L of NaF, whereas inhibited at >or= 2.00 mmol/L. ALP activity was increased at 0.01 - 0.05 mmol/L of NaF, and decreased at >or= 0.10 mmol/L. The inhibition on proliferation and differentiation at 2 mmol/L NaF was antagonized by vitamin C.</p><p><b>CONCLUSION</b>Fluoride had a two-phase effect on osteoblasts, vitamin C could antagonize the inhibitory effect of higher concentration of fluoride on proliferation and differentiation of osteoblasts.</p>

Clinical evaluation of risk factors for coronary heart disease / 中华预防医学杂志

<p><b>OBJECTIVE</b>To explore the relationship between risk factors for coronary heart disease (CHD) and coronary artery lesions.</p><p><b>METHOD</b>Potential risk factors were studied in 341 patients underwent coronary angiography.</p><p><b>RESULTS</b>(1) Coronary angiography showed coronary artery lesions in 214 patients (lesion group), and no lesion in 127 patients (non-lesion group). There was significant difference in age, past history of diabetes, family history of CHD, smoking history, high-density lipoprotein cholesterol (HDL-C), lower-density lipoprotein cholesterol (LDL-C), ratio of total cholesterol to HDL-C (TC/HDL-C), lipoprotein(a) [Lp(a)], fibrinogen (Fbg) and high-sensitivity C-reactive protein (hs-CRP) between two groups (P < 0.05). (2) There was significant correlation between severity of coronary artery lesions and hs-CRP, Lp(a), TC/HDL-C, Fbg, hyperlipidemia, TC, LDL-C and TG (with coefficients of correlation of 0.338, 0.250, 0.241, 0.207, 0.167, 0.147, 0.140 and 0.139; respectively, P < 0.05). (3) Analysis of receiver operating characteristics (ROC) curve for patients with coronary angiography and risk factors for CHD showed that the areas under ROC curve were 0.810, 0.669, 0.626, 0.625, 0.619 and 0.618 for hs-CRP, TC/HDL-C, Lp(a), Fbg, LDL-C and past history of hyperlipidemia, respectively.</p><p><b>CONCLUSIONS</b>Past history of hyperlipidemia was a predictor for occurrence of CHD. Ratio of TC/HDL-C and blood level of Lp(a) could be used as predictors in screening for high blood lipid, which were much stronger than others. It is suggested that hs-CRP had an excellent predictive value in current coronary inflammatory lesions.</p>