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1.
Acta Anatomica Sinica ; (6): 423-430, 2019.
Artigo em Chinês | WPRIM (Pacífico Ocidental) | ID: wpr-844629

RESUMO

Objective: To investigate the role of anterior part of commissural subnucleus of nucleus tractus solitarius (acNTS) injury in insulin-resistant hyperglycemia during chronic restraint stress (CRS). Methods: We produced the CRS models (n = 20, a 7-day restraint followed by a 3-day free moving procedure for 40 days) in rats, and detected the parameters related to glucose metabolism. Results: The CRS induced a moderate (not higher than 11 mmol/L) and irreversible insulin-resistant hyperglycemia in about 1/3 (n = 7) of the individuals. CRS-hyperglycemic rats showed a condensed staining of acNTS neurons, and Caspase-3 immunostaining and TUNEL also showed positive, indicating apoptotic changes of acNTS neurons. After acNTS mechanical damage (n= 6), the blood glucose level rised gradually, which also led to insulin-resistant hyperglycemia. The characteristics of hyperinsulinemia, increased islet volume, and serum corticosterone levels in acNTS mice were consistent with those of CRS mice. Conclusion: The result indicates that during CRS, injury (apoptosis) of glucose-sensitive acNTS neurons causes dysregulation of blood glucose. Restraint stress model has value as a potential application in the study of stress-induced hyperglycemia.

2.
Journal of Preventive Medicine ; (12): 1086-1090, 2019.
Artigo em Chinês | WPRIM (Pacífico Ocidental) | ID: wpr-815949

RESUMO

Objective@#To evaluate the pathogenicity of Acinetobacter venetum(Av),which is expected to be used as an environmental remediation agent,using Caenorhabditis elegans(C.elegans). @*Methods@#The C.elegans were cultured on the media loaded with E.coli OP50 and Av,respectively. The pathogenicity of Av was evaluated by observing the effects of Av on the growth,movement,digestive function,lifespan and reproduction of C.elegans,compared with that of another evaluation system according to NY 1109-2017 General Biosafety Standard for Microbial Fertilizers.@*Results@#By C. elegans system,it was found that the body length,width,head thrash frequency,body bending frequency and average lifespan [(13.5±0.4)d vs.(13.7±0.4)d] of adult nematodes in the Av group were not significantly different from those in the OP50 group(all P>0.05);while the average time of defecation cycle in the Av group shortened,the total number of progenies in the Av group increased by 18.7%(all P<0.05). According to NY1109-2017 General Biosafety Standard for Microbial Fertilizers,it was found that the oral LD50 values for both male and female mice were more than 10 g/kgbw,which was practically non-toxic;the pathogenicity test of acute intraperitoneal injection showed that the animals did not have signs of poisoning,deaths or any abnormalities in gross anatomy;Av had no irritation to damaged skin and eyes of rabbits;the hemolysis test was negative;Av was sensitive to seven antibiotics and was medium to one antibiotic. @*Conclusion@#Av is not pathogenic. C. elegans can be used in early screening for the pathogenicity of environmental remediation agents.

3.
Journal of Forensic Medicine ; (6): 526-531, 2018.
Artigo em Inglês | WPRIM (Pacífico Ocidental) | ID: wpr-984968

RESUMO

OBJECTIVES@#To investigate the genetic polymorphisms of 18 autosomal short tandem repeats (STR) loci in Changsha Han population, and explore the population genetic relationships and evaluate its application value in forensic medicine.@*METHODS@#The DNA of 2 004 unrelated individuals in Changsha Han population were amplified using Goldeneye®DNA ID System BASIC, and the PCR products were analyzed by electrophoresis using 3130xl genetic analyzer. The fragment sizes of alleles were analyzed subsequently by GeneMapper® ID v3.2. The frequency data and forensic genetic parameters [observed heterozygosity (Ho), expected heterozygosity (He), power of discrimination (DP) and polymorphic information content (PIC)] of 18 STR loci were statistically analyzed. Total probability of discrimination (TDP), probability of exclusion in trio cases (PEtrio) and probability of exclusion in duo cases (PEduo) were calculated by Cervus 3.0. Hardy-Weinberg equilibrium and linkage disequilibrium of the loci were detected by Arlequin v3.5. The results were compared with the available data of other populations from different races and regions.@*RESULTS@#The power of discrimination (DP), and the polymorphic information content (PIC) of each locus of Changsha Han population ranged from 0.783 6 to 0.987 9 and 0.549 4 to 0.914 5, respectively. The TDP, cumulative probability of exclusion in trio cases (CPEtrio) and cumulative probability of exclusion in duo cases (CPEduo) were 0.999 999 999 999 999 999 999 865 2, 0.999 999 979 and 0.999 988 325, respectively. According to the Nei's DA genetic distance, the genetic distance between Changsha Han and Hunan Han populations was the smallest (0.014 1), while it was the largest (0.041 8) between Changsha Han and Xinjiang Kazakh populations.@*CONCLUSIONS@#The 18 STR loci shows abundant genetic polymorphisms in Changsha Han population. The study of genetic diversity among different populations has an important meaning for the research of their origins, migrations and their relationships.


Assuntos
Humanos , Masculino , Alelos , Povo Asiático/genética , China , DNA/análise , Frequência do Gene , Genética Populacional , Repetições de Microssatélites , Polimorfismo Genético
4.
Journal of Forensic Medicine ; (6): 396-400, 2018.
Artigo em Inglês | WPRIM (Pacífico Ocidental) | ID: wpr-984951

RESUMO

OBJECTIVES@#To observe and analyse the Amelogenin allelic loss in parent-child identification cases, and to explore the type and mechanism of Amelogenin allelic loss as well as its influence on gender identification and solutions.@*METHODS@#After the detection by SiFaSTR™ 23plex DNA identification system, samples had the characteristics of the peak area of Amelogenin X was the same as the one of adjacent heterozygote or lower than one half of adjacent homozygote in females while Amelogenin X loss was observed in males were selected. X chromosome STR (X-STR) typing and Amelogenin X sequencing were performed. The samples with Amelogenin Y loss in males were confirmed by the detection of Y chromosome STR typing and sex-determining region of Y (SRY). The type and rate of Amelogenin allelic loss were confirmed and calculated, and the mechanism and influence of this variation were also analysed.@*RESULTS@#Amelogenin X allelic loss was observed in one male sample, the mutation in primer-binding region was confirmed by sequencing. The suspected Amelogenin X allelic loss was observed in four female samples, but the mutation in primer-binding region was confirmed by sequencing in only one sample. Amelogenin Y allelic loss was observed in seven male samples, SRY positive cases was detected in five of them, and two were SRY negative. Y-STR type was detected in four cases of the five SRY positive cases, which was not detected in the two SRY negative cases. The rate of Amelogenin allelic loss was about 0.029%.@*CONCLUSIONS@#Amelogenin X allelic loss does not affect the gender identification, but Amelogenin Y allelic loss may cause wrong gender identification. Thus, Y-STR or SRY should be detected for gender confirmation. When Y-STR genotypes are not detected in a "male" whose SRY detection is also negative, then the chromosome karyotype analysis and sex differentiation related genes test should be taken to further confirm the gender.


Assuntos
Feminino , Humanos , Masculino , Amelogenina/genética , DNA/genética , Perda de Heterozigosidade/genética , Análise para Determinação do Sexo
5.
Journal of Forensic Medicine ; (6): 263-266, 2017.
Artigo em Chinês | WPRIM (Pacífico Ocidental) | ID: wpr-620663

RESUMO

Objective T o observe and analyze the confirm ed cases of paternity testing, and to explore the m utation rules of ST R loci. Methods T he m utant ST R loci w ere screened from 20723 confirm ed cases of paternity testing by G oldeneye 20A system .T he m utation rates, and the sources, fragm ent length, steps and increased or decreased repeat sequences of m utant alleles w ere counted for the analysis of the characteristics of m utation-related factors. Results A total of 548 m utations w ere found on 19 ST R loci, and 557 m utation events w ere observed. T he loci m utation rate w as 0.07‰-2.23‰. T he ratio of pater-nal to m aternal m utant events w as 3.06:1. O ne step m utation w as the m ain m utation, and the num ber of the increased repeat sequences w as alm ost the sam e as the decreased repeat sequences. T he repeat se-quences w ere m ore likely to decrease in tw o steps m utation and above. M utation m ainly occurred in the m edium allele, and the num ber of the increased repeat sequences w as alm ost the sam e as the decreased repeat sequences. In long allele m utations, the decreased repeat sequences w ere significantly m ore than the increased repeat sequences. T he num ber of the increased repeat sequences w as alm ost the sam e as the decreased repeat sequences in paternal m utation, w hile the decreased repeat sequences w ere m ore than the increased in m aternal m utation. Conclusion T here are significant differences in the m utation rate of each locus. W hen one or tw o loci do not conform to the genetic law , other detection system should be added, and PI value should be calculated com bined w ith the inform ation of the m utate ST R loci in order to further clarify the identification opinions.

6.
Journal of Forensic Medicine ; (6): 263-266, 2017.
Artigo em Chinês | WPRIM (Pacífico Ocidental) | ID: wpr-984889

RESUMO

OBJECTIVES@#To observe and analyze the confirmed cases of paternity testing, and to explore the mutation rules of STR loci.@*METHODS@#The mutant STR loci were screened from 20 723 confirmed cases of paternity testing by Goldeneye 20A system.The mutation rates, and the sources, fragment length, steps and increased or decreased repeat sequences of mutant alleles were counted for the analysis of the characteristics of mutation-related factors.@*RESULTS@#A total of 548 mutations were found on 19 STR loci, and 557 mutation events were observed. The loci mutation rate was 0.07‰-2.23‰. The ratio of paternal to maternal mutant events was 3.06:1. One step mutation was the main mutation, and the number of the increased repeat sequences was almost the same as the decreased repeat sequences. The repeat sequences were more likely to decrease in two steps mutation and above. Mutation mainly occurred in the medium allele, and the number of the increased repeat sequences was almost the same as the decreased repeat sequences. In long allele mutations, the decreased repeat sequences were significantly more than the increased repeat sequences. The number of the increased repeat sequences was almost the same as the decreased repeat sequences in paternal mutation, while the decreased repeat sequences were more than the increased in maternal mutation.@*CONCLUSIONS@#There are significant differences in the mutation rate of each locus. When one or two loci do not conform to the genetic law, other detection system should be added, and PI value should be calculated combined with the information of the mutate STR loci in order to further clarify the identification opinions.


Assuntos
Humanos , Masculino , Alelos , Análise Mutacional de DNA/métodos , Família , Loci Gênicos , Repetições de Microssatélites , Mutação , Taxa de Mutação , Paternidade
7.
Anal Chim Acta ; 910: 75-83, 2016 Mar 03.
Artigo em Inglês | MEDLINE | ID: mdl-26873471

RESUMO

Microbial cells are known to form aggregates. Such aggregates can be found in various matrices; for example, functional drinks. Capillary hydrodynamic chromatography (HDC) enables separation of particles by size using nanoliter-scale volumes of samples. Here we propose an approach based on HDC for characterisation of real samples containing aggregated and non-aggregated bacterial and fungal cells. Separation of cells and cell aggregates in HDC arises from the parabolic flow profile under laminar flow conditions. In the presented protocol, hydrodynamic separation is coupled with different on-line and off-line detectors (light absorption/scattering and microscopy). The method has successfully been applied in the monitoring of dynamic changes in the microbiome of probiotic drinks. Chromatographic profiles of yogurt and kefir samples obtained at different times during fermentation are in a good agreement with microscopic images. Moreover, thanks to the implementation of an area imaging detector, capillary HDC could be multiplexed and used to profile spatial gradients in cell suspensions, which arise in the course of sedimentation of cells and cell aggregates. This result shows compatibility of sedimentation analysis and capillary HDC. We believe that the approach may find applications in the profiling of functional foods and other matrices containing aggregated bioparticles.


Assuntos
Bebidas/análise , Cromatografia Líquida/métodos , Laticínios/análise , Bactérias/crescimento & desenvolvimento , Fermentação , Hidrodinâmica , Probióticos
8.
Chinese Journal of Trauma ; (12): 650-654, 2016.
Artigo em Chinês | WPRIM (Pacífico Ocidental) | ID: wpr-497876

RESUMO

Objective To investigate the effect of microbubble-enhanced non-focused ultrasound on posttraumatic liver hemorrhage.Methods Twenty healthy New Zealand white rabbits with posttraumatic liver hemorrhage were divided into control group,microbubble group,ultrasound with microbubble group,and heparin with ultrasound and microbubble group according to the random number table,with five rabbits per group.Thrombin time (TT),prothrombin time (PT),activated partial thromboplastin time (APTT),fibrinogen (FIB),and coagulation reaction time (R value) and mechanical strength (A value) of the thrombelastogram were detected.Pre-and post-treatment bleeding were measured to evaluate the hemostatic effect.Liver specimens were harvested to perform histopathological study with HE staining.Results TT [(25.8 ± 11.3) s] and APTF [(58.7 ± 18.7) s] in heparin with ultrasound and microbubble group showed significant prolongation compared with other three groups (P < 0.05).Control group showed higher FIB than other three groups,but the differences were insignificant (P>0.05).PT did not differ significantly among groups (P>0.05).R value [(78.3±5.1) min] and A value [(0.13 ± 0.05)mm] in heparin with ultrasound and microbubble group differed significantly from these in other three groups (P0.05 ).After treatment,bleeding area in heparin with ultrasound and microbubble group [(2.2 ±1.3)cm2] wasincreased when compared to ultrasound with microbubble group[(0.8+0.7) cm2](p< 0.05 ), butboth were lower than that in control group [( 5.7+0.6)cm2 ]and microbubble group [( 5.3 ±0.6)cm2]( P<0.05). HE staining showed significant hepatic cell edema in ultrasound with microbubble groupand heparin with ultrasound and microbubble group that compressed hepatic sinus,blood vessels in theportal area and central vein,and significant blood stasis in blood vessels.Conclusion Microbubblesenhanced non-focused ultrasound has good hemostatic effect for posttraumatic liver hemorrhage.

9.
Artigo em Chinês | WPRIM (Pacífico Ocidental) | ID: wpr-789366

RESUMO

Objective To investigate the risk factors for recurrence of cerebral infarction and to propose secondary prevention methods . Methods Data of 628 patients with cerebral infarction from Jan.2012 to Dec.2014 were collected by the community reported network into a cohort study .The prevalence of recurrence and associated risk factors of cerebral infarction were investigated . Results Recurrence rate of cerebral infarction was 9.08%.History of hypertension (OR=4.797, P=0.001), long term of tobacco use ( OR=2 .844 , P=0 .005 ) , abdominal obesity or overweight ( OR=2 .421 , P=0.041) and farming(OR=3.723, P<0.001)were the independent risk factors for recurrence of cerebral infarction. Conclusion The recurrence rate of cerebral infraction is high , which is affected by various factors.

10.
Yonsei Medical Journal ; : 321-327, 2016.
Artigo em Inglês | WPRIM (Pacífico Ocidental) | ID: wpr-147359

RESUMO

PURPOSE: Increased lipoprotein-associated phospholipase A2 (Lp-PLA2) activity and Rho kinase activity may be associated with atherosclerosis. The principal aim of this study was to examine whether darapladib (a selective Lp-PLA2 inhibitor) could reduce the elevated Lp-PLA2 and Rho kinase activity in atherosclerosis. MATERIALS AND METHODS: Studies were performed in male Sprague-Dawley rats. The atherosclerosis rats were prepared by feeding them with a high-cholesterol diet for 10 weeks. Low-dose darapladib (25 mg.kg-1.d-1) and high-dose darapladib (50 mg.kg-1.d-1) interventions were then administered over the course of 2 weeks. RESULTS: The serum levels of triglycerides, total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), high-sensitivity C-reactive protein (hs-CRP), and Lp-PLA2, significantly increased in atherosclerosis model groups, as did Rho kinase activity and cardiomyocyte apoptosis (p0.05). CONCLUSION: Darapladib, a Lp-PLA2 inhibitor, leads to cardiovascular protection that might be mediated by its inhibition of both Rho kinase and Lp-PLA2 in atherosclerosis.


Assuntos
Animais , Masculino , Ratos , 1-Alquil-2-acetilglicerofosfocolina Esterase/antagonistas & inibidores , Aterosclerose/sangue , Benzaldeídos , Proteína C-Reativa/metabolismo , Colesterol/sangue , HDL-Colesterol/sangue , LDL-Colesterol/sangue , Relação Dose-Resposta a Droga , Oximas , Inibidores de Fosfolipase A2/administração & dosagem , Ratos Sprague-Dawley , Triglicerídeos/sangue , Quinases Associadas a rho/metabolismo
11.
Analyst ; 140(5): 1495-501, 2015 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-25622965

RESUMO

Digital microfluidics (DMF) based on the electrowetting-on-dielectric phenomenon is a convenient way of handling microlitre-volume aliquots of solutions prior to analysis. Although it was shown to be compatible with on-line mass spectrometric detection, due to numerous technical obstacles, the implementation of DMF in conjunction with MS is still beyond the reach of many analytical laboratories. Here we present a facile method for coupling open DMF microchips to mass spectrometers using Venturi easy ambient sonic-spray ionization operated at atmospheric pressure. The proposed interface comprises a 3D-printed body that can easily be "clipped" at the inlet of a standard mass spectrometer. The accessory features all the necessary connections for an open-architecture DMF microchip with T-shaped electrode arrangement, thermostatting of the microchip, purification of air (to prevent accidental contamination of the microchip), a Venturi pump, and two microfluidic pumps to facilitate transfer of samples and reagents onto the microchip. The system also incorporates a touch-screen panel and remote control for user-friendly operation. It is based on the use of popular open-source electronic modules, and can readily be assembled at low expense.

12.
Sci Rep ; 5: 8135, 2015 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-25633338

RESUMO

In order to ascertain optimum conditions for biocatalytic processes carried out in vitro, we have designed a bio-opto-electronic system which ensures real-time compensation for depletion of adenosine triphosphate (ATP) in reactions involving transfer of phosphate groups. The system covers ATP concentration range of 2-48 µM. The report demonstrates feasibility of the device operation using apyrase as the ATP-depleting enzyme.


Assuntos
Trifosfato de Adenosina/metabolismo , Microtecnologia/instrumentação , Microtecnologia/métodos , Algoritmos , Apirase/metabolismo , Eletrônica/instrumentação , Óptica e Fotônica/instrumentação
13.
Chinese Pharmaceutical Journal ; (24): 323-329, 2015.
Artigo em Chinês | WPRIM (Pacífico Ocidental) | ID: wpr-859440

RESUMO

By a targeting-delivery system, drugs are delivered and concentrated in a local district such as target tissues, organs, cells or a special district of cells to avoid harm to healthy tissues. Curcumin has various pharmacological activities, but the clinical application of curcumin is severely limited by its main drawbacks including instability, low solubility and poor bioavailability. Recently curcurnin-targeting dosage forms which improved the curcumin bioavailability surged. In this article, the new targeting-delivery systems and their use in curcumin delivery mainly including liposomes, ligand-receptors, magnetic iron oxides and other systems are reviewed in design methodologies and bioactive effects. Advantages and disadvantages for the target-delivery systems are discussed.

14.
Artigo em Chinês | WPRIM (Pacífico Ocidental) | ID: wpr-789346

RESUMO

Objective To evaluate different hypertension management models in communities and their impact on incidence of cardio-cerebrovascular disease in hypertensive patients. Methods A total of 1 578 hypertension patients in several communities in Pudong New Area were recruited in the study ( August 2008 to December 2012 ) according to the inclusion criteria and randomly divided into two groups.The control group was given routine hypertension management and the study group was given detailed hypertension management, while health commissioners and community physicians were in charge of the follow-up and data collection. Results The incidence of cardio-cerebrovascular disease (1.33%) in study group (1.33%) was significantly lower than that of the control group (4.22%) ( P <0.05). Multivariate logistic regression analysis showed that age, male, course-of-disease, patients with hypertension family history, increase in SCr and LDL-C increased the risk for getting ardio-cerebrovascular disease (P <0.05).The risk of study group was 0.348 times the control group ( P <0.05). Conclusion Compared with control group, detailed hypertension management model conducted in study group has the advantages that effectively reduced the rate of cardio-cerebrovascular disease.

15.
Artigo em Chinês | WPRIM (Pacífico Ocidental) | ID: wpr-789343

RESUMO

Objective To investigate epidemic characteristics and risk factors of hypertension among residents aged above 15 years in Pudong New Area of Shanghai. Methods We selected the subjects through a multistage stratified cluster sampling procedure; all thirty towns of Pudong New Area were stratified into three levels according to their economic status and 10 657 people selected as survey subjcets from each economic level.A questionnaire survey was conducted in conjunction with measurements of body height and weight, fasting plasma glucose, 2-hour postprandial blood glucose, blood lipid and blood pressure among 10 657 inhabitants aged above 15 years.Multivariate unconditional regression model was employed to analyze the influence factors of hypertension. Results The crude prevalence rate of hypertension in the residents was 41.3%.The prevalence rates of male was high than female (P<0.001). With the increment of age, the hypertension prevalence rate of all residents were obviously elevated.The residents with lower education had a higher hypertension prevalence rate.There was no significant difference in hypertension prevalence between rural and urban.The results of logistic regresssion showed that the risk factors of hypertension were age,gender,educational level,family history of hypertension,central obesity, body mass index, C-reactive protein, 2-hour postprandial blood glucose and urinary albumin/creatinine ratio(P<0.05). Conclusion The results indicated that hypertension was highly prevalent in Pudong New Area.Body mass index ( BMI) and central obesity were related factors for hypertension which were changeable.

16.
Yonsei Medical Journal ; : 196-203, 2015.
Artigo em Inglês | WPRIM (Pacífico Ocidental) | ID: wpr-174633

RESUMO

PURPOSE: Cutaneous lymphocyte-associated antigen (CLA)-expressing CD8+T cells have been known to play an important role in the pathogenesis of atopic dermatitis (AD). However, the mechanisms underlying the loss of self-tolerance remain unclear. Regulatory T cells (Tregs) play a key role in the development of homeostasis in the immune system. We, therefore, hypothesized that a reduced ability of Tregs to inhibit autologous CD8+CLA+T cells might be underlying mechanism in AD. MATERIALS AND METHODS: CD8+CLA+T cells and Tregs were obtained from the peripheral blood of AD patients and control volunteers. The frequencies of CD8+CLA+T cells were evaluated. The proliferative responses of CD8+CLA+T cells were assessed by flow cytometry, and the levels of transforming growth factor-beta1 (TGF-beta1) and interleukin-10 (IL-10) in culture supernatants were detected by enzyme-linked immunosorbent assay. RESULTS: Our results revealed higher frequency and increased expression of perforin and granzyme-B in peripheral CD8+CLA+T cells in AD, and lower inhibitory ability of Tregs on proliferation of CD8+CLA+T cells in AD. Meanwhile, the levels of TGF-beta1 produced by Tregs were significantly lower in AD, and anti-TGF-beta1 abolished such suppression. CONCLUSION: The attenuated inhibitory ability of Tregs on hyper-activated autologous CD8+CLA+T cells, mediated by TGF-beta1, plays an important role in the pathogenesis of AD.


Assuntos
Adulto , Idoso , Feminino , Humanos , Masculino , Linfócitos T CD8-Positivos/efeitos dos fármacos , Estudos de Casos e Controles , Proliferação de Células , Separação Celular , Dermatite Atópica/imunologia , Granzimas/metabolismo , Interleucina-10/metabolismo , Contagem de Linfócitos , Perforina/metabolismo , Pele/imunologia , Linfócitos T Citotóxicos/efeitos dos fármacos , Linfócitos T Reguladores/efeitos dos fármacos , Fator de Crescimento Transformador beta1/farmacologia
17.
Chinese Journal of Biotechnology ; (12): 445-454, 2014.
Artigo em Chinês | WPRIM (Pacífico Ocidental) | ID: wpr-279505

RESUMO

In order to analyze the correlation between critical residues in the catalytic centre of BSH and the enzyme substrate specificity, seven mutants of Lactobacillus salivarius bile salt hydrolase (BSH1) were constructed by using the Escherichia coli pET-20b(+) gene expression system, rational design and site-directed mutagenesis. These BSH1 mutants exhibited different hydrolytic activities against various conjugated bile salts through substrate specificities comparison. Among the residues being tested, Cys2 and Thr264 were deduced as key sites for BSH1 to catalyze taurocholic acid and glycocholic acid, respectively. Moreover, Cys2 and Thr264 were important for keeping the catalytic activity of BSH1. The high conservative Cys2 was not the only active site, other mutant amino acid sites were possibly involved in substrate binding. These mutant residues might influence the space and shape of the substrate-binding pockets or the channel size for substrate passing through and entering active site of BSH1, thus, the hydrolytic activity of BSH1 was changed to different conjugated bile salt.


Assuntos
Amidoidrolases , Genética , Metabolismo , Ácidos e Sais Biliares , Metabolismo , Escherichia coli , Metabolismo , Expressão Gênica , Lactobacillus , Genética , Especificidade por Substrato
18.
Anal Chim Acta ; 766: 77-82, 2013 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-23427803

RESUMO

This report focuses on the heterogeneous distribution of small molecules (e.g. metabolites) within dry deposits of suspensions and solutions of inorganic and organic compounds with implications for chemical analysis of small molecules by laser desorption/ionization (LDI) mass spectrometry (MS). Taking advantage of the imaging capabilities of a modern mass spectrometer, we have investigated the occurrence of "coffee rings" in matrix-assisted laser desorption/ionization (MALDI) and surface-assisted laser desorption/ionization (SALDI) sample spots. It is seen that the "coffee-ring effect" in MALDI/SALDI samples can be both beneficial and disadvantageous. For example, formation of the coffee rings gives rise to heterogeneous distribution of analytes and matrices, thus compromising analytical performance and reproducibility of the mass spectrometric analysis. On the other hand, the coffee-ring effect can also be advantageous because it enables partial separation of analytes from some of the interfering molecules present in the sample. We report a "hidden coffee-ring effect" where under certain conditions the sample/matrix deposit appears relatively homogeneous when inspected by optical microscopy. Even in such cases, hidden coffee rings can still be found by implementing the MALDI-MS imaging technique. We have also found that to some extent, the coffee-ring effect can be suppressed during SALDI sample preparation.


Assuntos
Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Aminacrina/química , Café/química , Grafite/química , Nanopartículas Metálicas/química , Platina/química , Espectrometria de Fluorescência , Compostos de Estanho/química
19.
Anal Chem ; 84(11): 5110-6, 2012 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-22583035

RESUMO

A microscale analytical platform integrating microbial cell culture, isotopic labeling, along with visual and mass spectrometric imaging with single-cell resolution has been developed and applied in the monitoring of cellular metabolism in fungal mycelium. The method implements open chips with a two-dimensional surface pattern composed of hydrophobic and hydrophilic zones. Two hydrophilic islands are used as medium reservoirs, while the hydrophobic area constitutes the support for the growing aerial hyphae, which do not have direct contact with the medium. The first island, containing (12)C(6)-glucose medium, was initially inoculated with the mycelium (Neurospora crassa), and following the initial incubation period, the hyphae progressed toward the second medium island, containing an isotopically labeled substrate ((13)C(6)-glucose). The (13)C atoms were gradually incorporated into cellular metabolites, which was revealed by MALDI-MS. The fate of the chitin-biosynthesis precursor, uridine diphosphate N-acetylglucosamine (UDP-GlcNAc), was monitored by recording mass spectra with characteristic isotopic patterns, which indicated the presence of various (12)C/(13)C isotopologues. The method enabled mapping the (13)C-labeled UDP-GlcNAc in fungal mycelium and recording its redistribution in hyphae, directly on the chip.


Assuntos
Quitina/análise , Hifas/química , Neurospora crassa/química , Uridina Difosfato N-Acetilglicosamina/análise , Quitina/biossíntese , Meios de Cultura , Glucose/metabolismo , Interações Hidrofóbicas e Hidrofílicas , Hifas/metabolismo , Marcação por Isótopo , Dispositivos Lab-On-A-Chip , Metabolômica , Neurospora crassa/metabolismo , Análise de Célula Única , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Uridina Difosfato N-Acetilglicosamina/metabolismo
20.
Artigo em Chinês | WPRIM (Pacífico Ocidental) | ID: wpr-746552

RESUMO

OBJECTIVE@#To observe the changes of distortion product otoacoustic emissions (DPOAE) in the patients with iron deficient anaemia (IDA).@*METHOD@#Sixty cases who were taken health physical examination at ZhaBei District Central Hospital were divided into two groups, the normal group (30 cases, 60 ears) and the IDA group (30 patients, 60 ears) depend on the results of examination of hemoglobin and serum ferritin. The changes of DPOAEs at 4 kHz were observed.@*RESULT@#A statistically significant decrease of DPOAE threshold level compared with the normal controls was seen at 4 kHz in the patients with IDA.@*CONCLUSION@#The decreased threshold level of DPOAE at 4 kHz in IDA patients should relate to sensorineural hearing loss directly.


Assuntos
Adolescente , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem , Anemia Ferropriva , Sangue , Audiometria de Tons Puros , Limiar Auditivo , Estudos de Casos e Controles , Cóclea , Ferritinas , Sangue , Hemoglobinas , Emissões Otoacústicas Espontâneas
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