A method for the determination of caffeine in urea was developed based on bubble-in-drop single drop microextraction (BID-SDME) followed by gas chromatography/mass spectrometry (GC-MS).Under the optimum conditions including chloroform as extraction solvent, an exposure volume of 1 μL, a bubble volume of 1.6 μL, stirring for 5 min at 300 r/min, 15% (m/V) NaCl, and a distance of 1 cm between bubble and stirring bar, the detection limit of this method was as low as 0.003 mg/L and the linear range was from 0.005 mg/L to 10 mg/L with correlation coefficient of 0.982.The recoveries of caffeine were from 89.2% to 107.5% at different spiked levels in human urine and the relative standard deviation (RSD, n=6) was less than 8%.

BACKGROUND: Having breakfast everyday is a behavior promoting health recommended WHO, while it is easy to be ignored.OBJECTIVE: To investigate the breakfast habits of pupils in Beijing and Shanghai so as to provide a scientific basis for further studying the problems in having breakfast among the pupils, drafting and developing "nutritious breakfast program for students".DESIGN: Stratified and cluster sampling and investigation study were used based on the pupils.SETTING: Institute of health for child of two universities.SUBJECTS: A total of 8688 six to eleven years old Beijing and Shanghai pupils were involved from March 2002 to June 2002. Among them 4692 pupils came from Beijing. There were 4637 valid questionnaires, 2386 of which were from male pupils and 2251 from female pupiIs. Among the total subjects, there were 4300 Shanghai pupils, and 4051 questionnaires were valid, of which 2031 were from the male pupils and 2020 from female students.METHODS: A self-administered questionnaire survey was conducted. The content of the questionnaire included the general conditions of the family, dietary preferences, food for breakfast, consumption of the milk food and so on.RESULTS: The results showed that about 25.8% boys and 21.6% girls in Beijing did not eat breakfast regularly; similarly, the percentage was about 11.4% for boys and 13.3% for girls in Shanghai. The reasons for not having breakfast included the following: They had no appetite, or had no enough time for it, or the parents were too busy to prepare in the mornings. For those of them who eat breakfasts, the nutrients of their breakfast usually were not adequate. 55% of the students had their breakfast prepared by their mothers. As for the eating sites, students mainly ate at home; the next was having it on the way to school or eating at the roadside luncheonettes. The cost of breakfast was 2 - 3 yuan. The breakfast behaviors of the pupils were closely related with the behaviors of their mothers( r = 0. 4333, P < 0.01 ).CONCLUSION: It is suggested that quality of breakfast of the pupils need to be improved. The behaviors of the parents influence their children in breakfast habits.

In this article, the authors expounded the necessary and problems of animal experiment post-ap-proval monitoring ( PAM) , which included who should do PAM, how to do PAM, and what the PAM can do. The authors also exposed the following suggestion: formulating the detailed rules, regulations and SOP, strengthening the training of PAM team member and animal experiment personnel, and monitoring the whole process of animal protocol review using the software.

Transglutaminase (TG) is a kind of calcium-dependent enzymes. The TGase family found in rodents and human contains 9 types, including TG1-7, blood coagulation factor XIIIa and erythrocyte membrane protein 4.2, with the former 8 types possessing catalytic activity. TG catalyzes various conversion reactions of glutamine, including transamination, deamination and esterification, and participates in post-transcriptional modification of proteins such as cross-linking peptides glutamine residue and lysyl-residue, stabilizing protein structure and catalyzing formation of protein aggregates. TGase has been found to contribute to a variety of important physiological and pathological processes and play a role in the pathogenesis of multiple diseases. Notably, neurodegenerative diseases such as Huntington's disease, spinocerebellar ataxia, Alzheimer's disease and Parkinson's disease, have a close connection with TGase's role in the human body.
Animals ; Brain ; enzymology ; Humans ; Neurodegenerative Diseases ; enzymology ; genetics ; Transglutaminases ; genetics ; metabolism

Non-coding expansion spinocerebellar ataxias (SCAs) are a group of autosomal dominant neurodegenerative diseases characterized by "CTA/CTG", "ATTCT", "TGGAA" expansion in non-coding region of the causative gene. Until now, 5 subtypes including SCA8, SCA10, SCA12, SCA31 and SCA36 have been mapped. Recently, the causative mutation for SCA36, namely intronic hexanucleotide GGCCTG expansion in NOP56 gene, has been identified in Japanese and Spanish pedigrees in succession. Compared with other subtypes of SCAs, there are certain distinctive characteristics for SCA36. The clinical and genetic features of SCA36 are reviewed in this paper.
Base Sequence ; Biomedical Research ; methods ; trends ; Chromosome Mapping ; Chromosomes, Human, Pair 20 ; genetics ; DNA Repeat Expansion ; genetics ; Genetic Predisposition to Disease ; genetics ; Humans ; Nuclear Proteins ; genetics ; Oligonucleotides ; genetics ; Spinocerebellar Ataxias ; genetics ; pathology

Objective To summarize and analyze the prenatal ultrasonic manifestations of 17q12 microdeletion syndrome ,so as to provide help for prenatal diagnosis . Methods It carried out a retrospective analysis of 21 cases of 17q12 microdeletion syndrome prenatally confirmed by chromosomal microarray analysis(CMA) in the third affiliated hospital of Zhengzhou University from 2015 .01 to 2018 .05 . Prenatal ultrasound findings were collected . A close follow-up was given for the cases . Results Of the 21 fetus ,20 cases were presented with bilateral hyperechogenic kidneys ,and 1 case showed duodenal obstruction . There were 4 cases accompanied with polyhydramnios ,8 cases with mild polyhydramnio ,and 9 cases with normal amniotic fluid index . Parents of 6 fetus underwent chromosomal examination ,of which 2 cases were inherited from the mother and 4 cases had new chromosomal mutations;Seven cases had a family history of diabetes and 3 cases had a family history of kidney disease;Twelve cases performed induced labor ,2 cases lost follow-up and 1 case was unborn . Six cases were born ,of the 6 cases ,1 case associated with mild dysmorphic facial features , and 1 case associated with bilateral renal cysts . Conclusions 17q12 microdeletion syndrome has specific prenatal ultrasound characteristics ,while echogenic kidneys are of great value in the diagnosis of 17q12 microdeletion syndrome prenatally .

OBJECTIVETo determine the frequency of spinocerebellar ataxia type 31 (SCA31) related mutations among patients from mainland China.

METHODSFor a cohort of molecularly unassigned patients comprised of 295 SCA patients (including 98 probands from families featuring autosomal dominant SCA and 197 sporadic cases) and 81 patients with hereditary spastic paraplegia (HSP) (including 23 probands from families with autosomal dominant HSP and 58 sporadic cases),TGGAA pentanucleotide expansion insertional mutation of the BEAN/TK2 gene was detected using repeat-primed PCR followed by capillary gel electrophoresis.

RESULTSNo TGGAA pentanucleotide insertion expansion in BEAN/TK2 gene was identified in the above cohort.

CONCLUSIONSCA31 is an extremely rare subtype of SCA and should not be included in routine genetic screening in mainland China.

Objective: To evaluate the effect of water-soluble components of atmospheric fine particulate matter PM2.5 on proliferation, migration, tyrosinase activity and melanin content of a human melanocyte line PIG1. Methods: PM2.5 was collected during haze weather in heating seasons, and processed into suspensions. PIG1 melanocytes were cultured and divided into 5 experimental groups and 1 control group. PIG1 melanocytes in the 5 experimental groups were treated with 10, 20, 50, 100 and 200 mg/L PM2.5 suspensions respectively for 48 hours, while cells in the control group were not treated with PM2.5 suspensions. In cell migration assay, there was only 1 experimental group treated with 10 mg/L PM2.5 suspensions. After treatment, methyl thiazol tetrazolium (MTT) assay, micropore filtration assay, DOPA oxidase assay and NaOH lysis method were performed to determine the cell proliferation rate, migration rate, tyrosinase activity and melanin content respectively. Statistical analysis was carried out by using t test for comparison of means of two samples, one-way analysis of variance for means of multiple samples, Student-Newman-Keuls (SNK) -q test for multiple comparisons, and linear correlation analysis for analysis of correlations. Results: Compared with the control group ([100 ± 1.41]%) , the proliferation rate of PIG1 cells significantly decreased in the 20-, 50-, 100- and 200-mg/L PM2.5 groups ([93.41 ± 2.13]%, [88.31 ± 1.3557]%, [79.75 ± 1.89]%, [69.83 ± 2.50]% respectively, all P < 0.05) . Linear correlation analysis showed that the proliferation rate and tyrosinase activity of PIG1 cells decreased with the increase in PM2.5 concentrations (r = -0.98, -0.93, respectively, both P < 0.01) . After the treatment with 10 mg/L PM2.5, the migration rate of PIG1 cells significantly decreased (66.23% ± 1.11%) compared with the control group ([76.86 ± 1.81]%, t = 7.55, P < 0.01) . With the increase in PM2.5 concentrations (50-200 mg/L) , the melanin content of PIG1 cells gradually decreased (r = -0.97, P < 0.01) . Conclusion Atmospheric fine particulate matter PM2.5 can affect the normal functions of melanocytes by inhibiting their proliferation and migration, and reducing their tyrosinase activity and melanin content.

Background Gastric carcinogenesis is a multifactorial and complex process, in which long non-coding RNAs (lncRNAs) play important roles as oncogenes or antioncogenes. Research has found that the expression of lncRNA LINC02859 is down-regulated in gastric cancer tissues and correlated with the degree of tumor differentiation and TNM stage, and also plays an important role in the development of malignant transformation of cells induced by environmental carcinogen N-methyl-N'-nitro-N-nitrosoguanidine (MNNG), but its mechanism of action is still unclear. Objective To explore the role and potential regulatory mechanism of gastric cancer-associated lncRNA LINC02859 in MNNG-induced malignant transformation of human normal gastric mucosal cells (GES-1). Methods A total of 110 gastric cancer patients from a high incidence area of gastric cancer in Gansu Province were selected, and their cancer tissues and normal gastric mucosa tissues adjacent to the cancer were collected to detect the expression level of LINC02859 by real-time quantitative PCR (RT-qPCR). High-throughput sequencing and bioinformatics analysis of the tissues were used to identify the potential signaling pathways regulated by the genes co-expressed with LINC02859. GES-1 cells at 70%-80% cell fusion with low cell passage number and normal morphology were incubated with 0, 0.25 and 0.5 μmol·L⁻¹ MNNG solution for 48 h and the LINC02859 expression level was detected. Cell proliferation activity was detected by Cell Counting Kit-8 (CCK-8), clone formation was detected by plate clone formation assay, and cell migration ability was detected by scratch assay to evaluate the effects of MNNG on cell morphology and function. The expression levels of key proteins of Wnt signaling pathway were detected by RT-qPCR and Western blotting. Results The RT-qPCR results showed that LINC02859 was lowly expressed in the gastric cancer tissues compared with the paracancerous tissues, and the difference was statistically significant (P < 0.05). The pathway enrichment analysis showed that LINC02859 potentially regulated the Wnt pathway. The in vitro malignant transformation assay suggested that after the MNNG exposure, the malignant cells of passage 5 (MC-5) had altered morphology, increased number of colony formation, and higher proliferation and migration ability than the control cells; compared with the normal GES-1 cells, LINC02859 gene expression levels were reduced in the 0.25 μmol·L⁻¹ and the 0.5 μmol·L⁻¹ MNNG-exposed GES-1 cells; the expression levels of key proteins of the Wnt pathway, transcription factor 7 (TCF7), Axis inhibitor (Axin1), phosphorylation of glycogen synthase kinase-3 beta (p-GSK-3β), casein kinase 1 (CK1), and β-catenin, were elevated in the cells after 0.5 μmol·L⁻¹ MNNG exposure (P < 0.05); whereas, overexpression of LINC02859 suppressed the activating effect of MNNG on the Wnt pathway. Conclusion LINC02859 is lowly expressed in the cancer tissues of gastric cancer patients. MNNG exposure induces morphological and functional changes in GES-1 cells, down-regulated expression of LINC02859, and activation of the Wnt signaling pathway; overexpression of LINC02859 inhibits the activation of the Wnt signaling pathway in the gastric carcinogenesis induced by MNNG exposure.

Humans ; Severe Acute Respiratory Syndrome ; diagnosis ; therapy