Overexpression of wild-type HRAS drives non-alcoholic steatohepatitis to hepatocellular carcinoma in mice.

Hepatocellular carcinoma (HCC), a prevalent solid carcinoma of significant concern, is an aggressive and often fatal disease with increasing global incidence rates and poor therapeutic outcomes. The etiology and pathological progression of non-alcoholic steatohepatitis (NASH)-related HCC is multifactorial and multistage. However, no single animal model can accurately mimic the full NASH-related HCC pathological progression, posing considerable challenges to transition and mechanistic studies. Herein, a novel conditional inducible wild-type human HRAS overexpressed mouse model (HRAS-HCC) was established, demonstrating 100% morbidity and mortality within approximately one month under normal dietary and lifestyle conditions. Advanced symptoms of HCC such as ascites, thrombus, internal hemorrhage, jaundice, and lung metastasis were successfully replicated in mice. In-depth pathological features of NASH- related HCC were demonstrated by pathological staining, biochemical analyses, and typical marker gene detections. Combined murine anti-PD-1 and sorafenib treatment effectively prolonged mouse survival, further confirming the accuracy and reliability of the model. Based on protein-protein interaction (PPI) network and RNA sequencing analyses, we speculated that overexpression of HRAS may initiate the THBS1-COL4A3 axis to induce NASH with severe fibrosis, with subsequent progression to HCC. Collectively, our study successfully duplicated natural sequential progression in a single murine model over a very short period, providing an accurate and reliable preclinical tool for therapeutic evaluations targeting the NASH to HCC continuum.

[Determination of seven monoaromatic hydrocarbon metabolites by ultra performance liquid chromatography-tandem mass spectrometry].

Monoaromatic hydrocarbons (MAHs) such as benzene, toluene, and xylene are important anthropogenic pollutants in the urban atmosphere. The detection of urinary MAH metabolites are included in human biomonitoring programs in several countries, including Canada, the United States, Italy, and Germany, because their evaluation is vital to monitor the exposure of humans to MAHs. To this end, herein, a method was developed for the determination of seven MAH metabolites through ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). An aliquot of 0.5 mL urine was fortified with an isotopic labeled internal standard solution before being hydrolyzed by 40 µL of 6 mol/L HCl solution, followed by extraction using a 96-well EVOLUTE®EXPRESS ABN solid-phase extraction plate. The samples were washed with 1.0 mL of methanol-water (10∶90, v/v) and eluted with 1.0 mL methanol. The eluate was diluted four times with water prior to use in instrumental analysis. Chromatographic separation was achieved using an ACQUITY UPLC HSS T3 column (100 mm×2.1 mm, 1.8 µm), with gradient elution using 0.1% formic acid as mobile phase A and methanol as mobile phase B. The detection of seven analytes was performed using a triple-quadrupole mass spectrometer equipped with a negative electrospray ionization source in the multiple reaction monitoring mode. The linear ranges of the seven analytes varied from 0.1-20 µg/L to 2.5-500 mg/L, with correlation coefficients greater than 0.995. The method detection limits were 1.5, 0.02, 0.1, 900, 0.6, and 4 µg/L for trans,trans-muconic acid (MU), S-phenylmercapturic acid (PMA), S-benzylmercapturic acid (BMA), hippuric acid (HA), 2-methyl hippuric acid (2MHA), and 3-methyl hippuric acid (3MHA)+4-methyl hippuric acid (4MHA), respectively. The limits of quantification were 5, 0.05, 0.4, 3000, 2, and 12 µg/L for MU, PMA, BMA, HA, 2MHA, and 3MHA+4MHA, respectively. The method was verified by spiking urine samples at three different concentration levels, with recovery rates ranging from 84% to 123%. The intra- and inter-day precisions were 1.8%-8.6% and 1.9%-21.4%, respectively. The extraction efficiencies were 68%-99%, and the matrix effects ranged from -11% to -87%. The urine samples obtained from the German external quality assessment scheme (round 65) were used to assess the accuracy of this method. Both high and low concentrations of MU, PMA, HA, and methyl hippuric acid were within the tolerance range. All analytes in the urine samples were found to be stable for up to seven days at room temperature (20 ℃, absence of light), with less than 15% change in concentration. Analytes in urine samples were found to be stable for at least 42 d at 4 ℃ and -20 ℃, or for six freeze-thaw cycles and up to 72 h in an autosampler (8 ℃). The method was applied to the analysis of 16 non-smokers' and 16 smokers' urine samples. The detection rates of MU, BMA, HA, and 2MHA were 100% in both non-smokers' and smokers' urine samples. PMA was detected in 75% non-smokers' and 100% smokers' urine samples. 3MHA+4MHA was detected in 81% non-smokers' urine and in all smokers' urine samples. Statistical differences were found for MU, PMA, 2MHA, and 3MHA+4MHA between the two groups (p<0.001). The established method has good robustness and can provide reliable results. The experiments were carried out in a high-throughput manner with large sample sizes, owing to the small sample volume, and allowed the successful detection of the seven MAH metabolites in human urine.

[Determination of phenoxyacetic herbicides, metabolites of organophosphorus and pyrethroid pesticides in human urine using solid phase extraction coupled with ultra-performance liquid chromatography-tandem mass spectrometry].

Pesticides are widely used in most agricultural areas to protect food crops but adversely affect ecosystems and human beings. Pesticides have attracted great public concern due to their toxic properties and ubiquitous occurrence in the environment. China is one of the largest users and producers of pesticides globally. However, limited data are available on pesticide exposure in humans, which warrants a method for quantification of pesticides in human samples. In the present study, we validated and developed a comprehensive and sensitive method for the quantification of two phenoxyacetic herbicides, two metabolites of organophosphorus pesticides and four metabolites of pyrethroid pesticides in human urine using 96-well plate solid phase extraction (SPE) coupled with ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). For this purpose, a systematic optimization of the chromatographic separation conditions and MS/MS parameters was conducted. Six solvents were optimized for the extraction and clean-up of human urine samples. The targeted compounds in the human urine samples were well separated within 16 min in one analytical run. A 1 mL aliquot of human urine sample was mixed with 0.5 mL sodium acetate buffer (0.2 mol/L) and hydrolyzed by ß-glucuronidase enzyme at 37 ℃ overnight. The eight targeted analytes were extracted and cleaned using an Oasis HLB 96-well solid phase plate and eluted with methanol. The separation of the eight target analytes was performed on a UPLC Acquity BEH C18 column (150 mm×2.1 mm, 1.7 µm) with gradient elution using 0.1% (v/v) acetic acid in acetonitrile and 0.1% (v/v) acetic acid in water. The analytes were identified using the multiple reaction monitoring (MRM) mode under negative electrospray ionization (ESI-) and quantified by isotope-labelled analogs. Para-nitrophenol (PNP), 3,5,6-tricholor-2-pyridinol (TCPY) and cis-dichlorovinyl-dimethylcyclopropane carboxylic acid (cis-DCCA) exhibited good linearities ranging from 0.2 to 100 µg/L, and 3-phenoxy benzoic acid (3-PBA), 4-fluoro-3-phenoxy benzoic acid (4F-3PBA), 2,4-dicholorphenoxyacetic acid (2,4-D), trans-dichlorovinyl-dimethylcyclopropane carboxylic acid (trans-DCCA) and 2,4,5-tricholorphenoxyacetic acid (2,4,5-T) showed linearity ranging from 0.1 to 100 µg/L with correlation coefficients all above 0.9993. Method detection limits (MDLs) and method quantification limits (MQLs) of targeted compounds were in the range of 0.02 to 0.07 µg/L and 0.08 to 0.2 µg/L, respectively. The spiked recoveries of target compounds at three levels of 0.5, 5 and 40 µg/L were 91.1% to 110.5%. The inter- and intra-day precisions of targeted analytes were 2.9% to 7.8% and 6.2% to 10%, respectively. This method was applied to the analysis of 214 human urine samples across China. The results showed that all the targeted analytes, except 2,4,5-T, were detected in human urine. The detection rates of TCPY, PNP, 3-PBA, 4F-3PBA, trans-DCCA, cis-DCCA, and 2,4-D were 98.1%, 99.1%, 94.4%, 2.80%, 99.1%, 63.1% and 94.4%, respectively. The median concentration of targeted analytes in a decreasing order were: 2.0 µg/L (TCPY), 1.8 µg/L (PNP), 0.99 µg/L (trans-DCCA), 0.81 µg/L (3-PBA), 0.44 µg/L (cis-DCCA), 0.35 µg/L (2,4-D) and below MDLs (4F-3PBA ). For the first time, we developed a method to extract and purify specific biomarkers of pesticides from human samples based on offline 96-well SPE. This method has the advantages of simple operation, high sensitivity, and high accuracy. Moreover, up to 96 human urine samples were analyzed in one batch. It is suitable for the determination of eight specific pesticides and their metabolites in large sample sizes.

Urinary Creatinine Concentrations and Its Explanatory Variables in General Chinese Population: Implications for Creatinine Limits and Creatinine Adjustment.

Objective: The study aimed to analyze the applicability of the World Health Organization's exclusionary guidelines for Urinary creatinine (Ucr) in the general Chinese population, and to identify Ucr related factors. Methods: We conduct a cross-sectional study using baseline data from 21,167 participants in the China National Human Biomonitoring Program. Mixed linear models and restricted cubic splines (RCS) were used to analyze the associations between explanatory variables and Ucr concentration. Results: The geometric mean and median concentrations of Ucr in the general Chinese population were 0.90 g/L and 1.01 g/L, respectively. And 9.36% samples were outside 0.3-3.0 g/L, including 7.83% below the lower limit and 1.53% above the upper limit. Middle age, male, obesity, smoking, higher frequency of red meat consumption and chronic kidney disease were associated significantly with higher concentrations of Ucr. Results of the RCS showed Ucr was positively and linearly associated with body mass index, inversely and linearly associated with systolic blood pressure, diastolic blood pressure, triglycerides level, and glomerular filtration rate, and were non-linearly associated with triiodothyronine. Conclusion: The age- and gender-specific cut-off values of Ucr that determine the validity of urine samples in the general Chinese population were recommended. To avoid introducing bias into epidemiologic associations, the potential predictors of Ucr observed in the current study should be considered when using Ucr to adjust for variations in urine dilution.

Effectiveness of methylprednisolone therapy in patients with a high-risk common type of COVID-19 pneumonia: a retrospective cohort study.

The optimal timing of glucocorticoid treatment for coronavirus disease 2019 (COVID-19) pneumonia is uncertain. We evaluated the clinical outcomes of methylprednisolone therapy (MPT) for patients with a high-risk common type (HRCT) COVID-19 pneumonia. We conducted a multicenter retrospective cohort study in Northeast China. A comparison was performed between the standard treatment (SDT) group and the SDT + MPT group to determine the efficacy of methylprednisolone in treating HRCT COVID-19 pneumonia. We collected the medical records of 403 patients with HRCT COVID-19 pneumonia (127 in the SDT + MPT group and 276 in the SDT group). None of the patients had received mechanical ventilation or died. Furthermore, there were no side effects associated with MPT. Patients in the SDT + MPT group treated with methylprednisolone received an intravenous injection for a median interval of five days (interquartile range of 3 to 7 days). The trends in lymphocyte count, C-reactive protein, interleukin 6, lactic acid dehydrogenase, respiratory rate, SpO2, PaO2, D-dimer and body temperature were similar between the SDT + MPT and SDT groups. The results for the SDT + MPT group seemed to improve faster than those for the SDT group; however, the results were not statistically significant. Clinical outcomes revealed that the average hospitalized days and the rate of progression to severe type COVID-19 pneumonia in both the SDT + MPT group and the SDT group were 14.56 ± 0.57 days versus 16.55 ± 0.3 days (p = 0.0009) and 21.26% (27/127) versus 32.4% (89/276) (p = 0.0247), respectively. The 16-day nucleic acid negative rate was higher in the SDT + MPT group than in the SDT group, 81.73% (104/127) versus 65.27% (180/276) (p = 0.0006). MPT effectively prevents patients with HRCT COVID-19 pneumonia from progressing to the severe stage.

Fatigue prevalence in men treated for prostate cancer: A systematic review and meta-analysis.

BACKGROUND: The side effects of prostate cancer (PCa) treatment are very prominent, with cancer-related fatigue (CRF) being the most common. Fatigue is a distressing symptom that interferes with daily functioning and seriously affects patient quality of life during, and for many years after, treatment. However, compared with other types of cancer, such as breast cancer, little is known about the prevalence of PCa-related fatigue. AIM: To determine the prevalence of CRF in patients with PCa. METHODS: A systematic search of EMBASE, PubMed, Web of Science, Cochrane Library, Chinese National Knowledge Infrastructure, WANFANG DATA, Technology Journal Database and the Chinese Biological Medical Database was conducted up to July 28, 2020. Included studies measured the incidence of PCa-related fatigue and differentiated fatigue outcomes (incidence) between treatment modalities and fatigue assessment times. In our meta-analysis, both fixed and random-effects models were used to estimate the pooled prevalence of PCa-related fatigue. Subgroup analyses were performed using treatment modalities and fatigue assessment times. Publication and sensitivity bias analyses were performed to test the robustness of the associations. RESULTS: Fourteen studies, involving 4736 patients, were eligible for the review. The pooled CRF prevalence was 40% in a total sample of 4736 PCa patients [95% confidence interval (CI): 29-52; P < 0.01; I 2 = 98%]. The results of the subgroup analyses showed the prevalence of CRF after androgen deprivation therapy treatment, radical prostatectomy and radiotherapy to be 42% (95%CI: 20-67, P < 0.01, I 2 = 91%), 21% (95%CI: 16-26, P = 0.87, I 2 = 0%) and 40% (95%CI: 22-58, P < 0.01, I 2 = 90%), respectively. The prevalence of acute and persistent fatigue was 44% (95%CI: 25-64; P < 0.01; I 2 = 93%) and 29% (95%CI: 25-32; P = 0.30; I 2 = 17%), respectively. CONCLUSION: Our meta-analysis showed that fatigue is a common symptom in men with PCa, especially those using hormone therapy.

Delayed xenon post-conditioning mitigates spinal cord ischemia/reperfusion injury in rabbits by regulating microglial activation and inflammatory factors.

The neuroprotective effect against spinal cord ischemia/reperfusion injury in rats exerted by delayed xenon post-conditioning is stronger than that produced by immediate xenon post-conditioning. However, the mechanisms underlying this process remain unclear. Activated microglia are the main inflammatory cell type in the nervous system. The release of pro-inflammatory factors following microglial activation can lead to spinal cord damage, and inhibition of microglial activation can relieve spinal cord ischemia/reperfusion injury. To investigate how xenon regulates microglial activation and the release of inflammatory factors, a rabbit model of spinal cord ischemia/reperfusion injury was induced by balloon occlusion of the infrarenal aorta. After establishment of the model, two interventions were given: (1) immediate xenon post-conditioning-after reperfusion, inhalation of 50% xenon for 1 hour, 50% N2/50%O2 for 2 hours; (2) delayed xenon post-conditioning-after reperfusion, inhalation of 50% N2/50%O2 for 2 hours, 50% xenon for 1 hour. At 4, 8, 24, 48 and 72 hours after reperfusion, hindlimb locomotor function was scored using the Jacobs locomotor scale. At 72 hours after reperfusion, interleukin 6 and interleukin 10 levels in the spinal cord of each group were measured using western blot assays. Iba1 levels were determined using immunohistochemistry and a western blot assay. The number of normal neurons at the injury site was quantified using hematoxylin-eosin staining. At 72 hours after reperfusion, delayed xenon post-conditioning remarkably enhanced hindlimb motor function, increased the number of normal neurons at the injury site, decreased Iba1 levels, and inhibited interleukin-6 and interleukin-10 levels in the spinal cord. Immediate xenon post-conditioning did not noticeably affect the above-mentioned indexes. These findings indicate that delayed xenon post-conditioning after spinal cord injury improves the recovery of neurological function by reducing microglial activation and the release of interleukin-6 and interleukin-10.

A case report of spontaneous staphylococcal meningitis in a cynomolgus monkey.

This report describes a suppurative meningitis in a young cynomolgus. The animal had neutrophil aggregation in the subarachnoid space and hemorrhage in bilateral adrenal glands. Staphylococcus was identified by FISH in brain. To our knowledge, this is the first case of staphylococcal meningitis with Waterhouse-Friderichsen syndrome in a cynomolgus monkey.

Anti-proliferation of triple-negative breast cancer cells with physagulide P: ROS/JNK signaling pathway induces apoptosis and autophagic cell death.

Physagulide P (PP), a new natural compound, was isolated from Physalis angulate L. in our laboratory. In this study, we demonstrated that PP potently suppressed cell proliferation by inducing G2/M phase arrest in MDA-MB-231 and MDA-MB-468 cells. Moreover, PP provoked apoptosis by decreasing the mitochondrial membrane potential and elevating the Bax/Bcl-2 protein expression ratio. The caspase inhibitor Z-VAD-FMK partly restore cell viability, suggesting that apoptosis plays as an important role in the anti-proliferative effect of PP. PP-treated cells also underwent autophagy, as evidenced by the formation of autophagosomes and the accumulation of LC3BII. Furthermore, the knockdown of LC3B reduced PP-induced cytotoxicity, indicating that autophagy played an anticancer effect. PP also induced the generation of reactive oxygen species (ROS) and resulted in c-Jun N-terminal kinases (JNK) activation. Accordingly, JNK siRNA significantly attenuated PP-triggered apoptosis and autophagy, and ROS scavengers almost completely reverse this apoptosis and autophagy. The ROS scavenger also blocked PP-induced G2/M phase arrest and the phosphorylation of JNK. Our results revealed that PP induced G2/M phase arrest, apoptosis and autophagy via the ROS/JNK signaling pathway in MDA-MB-231 and MDA-MB-468 cells. Therefore, PP is a promising candidate for the development of antitumor drugs for the treatment of triple-negative breast cancer.

Protosappanin a inhibits osteoclastogenesis via reducing oxidative stress in RAW264.7 cells.

Protosappanin A (PrA), obtained from the traditional Chinese herbal medicine, Caesalpinia sappan L. (Lignum Sappan), possesses a lot of pharmaceutical activities. Typically, it is a potent antioxidant. This study makes an effort to test its protective effects against osteoporosis by partially reducing oxidative stress in RAW264.7 cells and a mouse ovariectomized (OVX) osteoporosis model. The influence that PrA affected on osteoclastic proliferation and differentiation under oxidative status was investigated. Our results revealed that PrA significantly inhibited the proliferation of RAW264.7 cells in oxidative stress conditions. Moreover, it suppressed some osteoclastic markers by TRAP staining, bone section assay and quantitative real-time PCR. PrA decreased reactive oxygen species (ROS) generation in RAW264.7 cells. In vivo, our results demonstrated that PrA supplementation improved some serum oxidative markers, including malondialdehyde (MDA) and reduced glutathione (GSH), and inhibited some osteoclastic markers, such as CTX-1 and TRAP. Importantly, it ameliorated the micro-architecture of trabecular bones by micro-CT assay. In summary, these findings showed that protection by PrA against osteoporosis is associated with a reduction in oxidative stress, suggesting that PrA may be useful in bone resorption related diseases, especially osteoporosis.

Effect of an Experimental Direct Pulp-capping Material on the Properties and Osteogenic Differentiation of Human Dental Pulp Stem Cells.

Effective pulp-capping materials must have antibacterial properties and induce dentin bridge formation; however, many current materials do not satisfy clinical requirements. Accordingly, the effects of an experiment pulp-capping material (Exp) composed of an antibacterial resin monomer (MAE-DB) and Portland cement (PC) on the viability, adhesion, migration, and differentiation of human dental pulp stem cells (hDPSCs) were examined. Based on a Cell Counting Kit-8 assay, hDPSCs exposed to Exp extracts showed limited viability at 24 and 48 h, but displayed comparable viability to the control at 72 h. hDPSC treatment with Exp extracts enhanced cellular adhesion and migration according to in vitro scratch wound healing and Transwell migration assays. Exp significantly upregulated the expression of osteogenesis-related genes. The hDPSCs cultured with Exp exhibited higher ALP activity and calcium deposition in vitro compared with the control group. The novel material showed comparable cytocompatibility to control cells and promoted the adhesion, migration, and osteogenic differentiation of hDPSCs, indicating excellent biocompatibility. This new direct pulp-capping material containing MAE-DB and PC shows promise as a potential alternative to conventional materials for direct pulp capping.

Combining GRP78 suppression and MK2206-induced Akt inhibition decreases doxorubicin-induced P-glycoprotein expression and mitigates chemoresistance in human osteosarcoma.

P-glycoprotein (P-gp) overexpression is associated with poor prognosis and drug-resistance in osteosarcoma (OS), but the underlying mechanisms remain incompletely understood. Here, we examined the regulation of P-gp, GRP78, and phospho-Akt in doxorubicin (DOX)-treated OS cells. DOX induced P-gp expression, which was associated with increased GRP78 levels and Akt activation in vitro and in vivo. Functional analysis showed that Akt induces P-gp and GRP78 expression, which contributes to the DOX-induced Akt activation. Examination of the relationship between Akt and GRP78 demonstrated that GRP78 suppression attenuates the Akt activity in OS parental sensitive and resistant cells, indicating that GRP78 is required for full Akt activity. Inhibition of Akt activity using MK2206 decreased GRP78 expression in OS cells, which enhanced the inhibitory effect of MK2206 on P-gp expression. GRP78 knockdown combined with MK2206 suppressed the development of DOX resistance in OS cells and inhibited the in vivo tumor growth in the presence of DOX. These results support the development of novel therapeutic strategies that target GRP78 and Akt to sensitize OS cells for chemotherapy.

Serine-threonine protein kinase activation may be an effective target for reducing neuronal apoptosis after spinal cord injury.

The signaling mechanisms underlying ischemia-induced nerve cell apoptosis are poorly understood. We investigated the effects of apoptosis-related signal transduction pathways following ischemic spinal cord injury, including extracellular signal-regulated kinase (ERK), serine-threonine protein kinase (Akt) and c-Jun N-terminal kinase (JNK) signaling pathways. We established a rat model of acute spinal cord injury by inserting a catheter balloon in the left subclavian artery for 25 minutes. Rat models exhibited notable hindlimb dysfunction. Apoptotic cells were abundant in the anterior horn and central canal of the spinal cord. The number of apoptotic neurons was highest 48 hours post injury. The expression of phosphorylated Akt (p-Akt) and phosphorylated ERK (p-ERK) increased immediately after reperfusion, peaked at 4 hours (p-Akt) or 2 hours (p-ERK), decreased at 12 hours, and then increased at 24 hours. Phosphorylated JNK expression reduced after reperfusion, increased at 12 hours to near normal levels, and then showed a downward trend at 24 hours. Pearson linear correlation analysis also demonstrated that the number of apoptotic cells negatively correlated with p-Akt expression. These findings suggest that activation of Akt may be a key contributing factor in the delay of neuronal apoptosis after spinal cord ischemia, particularly at the stage of reperfusion, and thus may be a target for neuronal protection and reduction of neuronal apoptosis after spinal cord injury.

[Molida therapy in the out-patient department for patients with III B prostatitis].

OBJECTIVE: To study the therapeutic effect of Molida therapy in the out-patient department for patients with III B prostatitis. METHODS: One hundred and thirty-six patients with II B prostatis accompanied with psychological disorder of different degrees were divided into two groups: Group A (68 cases), treated with routine drug and Molida therapy, and Group B (68 cases), treated with routine drug only. The therapeutic effects of the two groups were analyzed. RESULTS: After an 8-week treatment, the scores of self-feeling symptoms of SCL-90, SAS and SDS in Group A were 70.5 +/- 22.3, 18.7 +/- 8.5 and 21.4 +/- 9.0, respectively, significantly lower than those in Group B (P < 0.05) and the rates of efficacy and obvious efficacy in alleviating prostatodynia in Group A were 100% and 72.1%, respectively, both higher than in Group B (P < 0.05). CONCLUSION: Molida therapy in the out-patient department is useful in improving the psychological disorder and enhancing the therapeutic effect for patients with III B prostatitis.

[Determination of vitamins D2, vitamin D3 in cosmetics by high performance liquid chromatography].

OBJECTIVE: A high performance liquid chromatography method was used to detect vitamins D2 and vitamin D3, which is useful to know the use of vitamins D2 and vitamin D3 in cosmetics, prohibit the influx of cosmetics containing vitamins D2 and vitamin D3 to cosmetic market, safeguard the health of consumers. METHODS: A high performance liquid chromatography method was established for determination of vitamins D2 and vitamin D3 in cosmetics. The separation condition was optimized by trying different type of columns and mobile phases. RESULTS: The experiment goes on a Alltima C18 column (250 mm x 4.6 mm I. D., 5 microm)using methanol-acetonitrile (90: 10) as mobile phase at a flow rate of 1.0 ml/min, with the column temperature 25 degrees C and detection wave 265nm. The liner range is from 0.5 mg/L to 100 mg/L with good relationship. The detection limit of vitamin D2 is 0. 12 mg/L, the precision is less than 3.8% and recovery varies from 94.2% to 101.4%, while the detection limit of vitamin D3 is 0.06 mg/L, the precision is less than 3.5% and recovery varies from 91.6% to 97.2%. CONCLUSION: The method is simple, precise and accurate, which is suitable for the determination of vitamins D2 and vitamin D3 in cosmetics.

[Determination of antidangdruff agent salicylic acid, zinc pyrithione, octopirox, climbazole and ketoconazole in shampoo by high performance liquid chromatography].

A high performance liquid chromatography method was established for determination of antidangdruff agent salicylic acid,zinc pyrithione, octopirox, climbazole and ketoconazole in shampoo on a C18 column using acetonitrile-metholaqueous solution (10 mmol/L KH2 PO4 and 5 mmol/L EDTANa2, pH is adjusted to 4.0 with H3 PO4) (50:10:40) as mobile phase at a flow rate of 1.0 ml/min, with the column temperature 25 degrees C and detection wave 230nm. The precision was less than 3.8% and recovery varied from 92.7% to 104.9%. The experimental results showed that the method was simple, precise and accurate.