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1.
J Appl Microbiol ; 127(6): 1759-1767, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31463998

RESUMO

AIMS: The purpose of this study was to investigate the bacterial community of wild Cordyceps cicadae and explore its effect on the production of N6-(2-hydroxyethyl)-adenosine (HEA) and three nucleosides in C. cicadae. METHODS AND RESULTS: Illumina high-throughput sequencing technology was used to analyse the bacterial community in wild C. cicadae. After C. cicadae was isolated and bacteria were isolated from wild C. cicadae, we identified four bacterial strains that independently altered HEA and nucleoside production in a coculture with C. cicadae and four bacteria separately. After cocultivation, the HEA yield from C. cicadae increased markedly. The bacteria in wild C. cicadae did not produce HEA, and the levels of three nucleosides decreased significantly. Both 16S rRNA and community analyses showed close evolutionary relationships and high abundance ratios for the four selected bacterial strains. CONCLUSIONS: Some bacteria exist in wild C. cicadae and have a high abundance ratio. Moreover, the isolated bacteria inhibited the growth of C. cicadae and prevented the production of HEA in axenic cultures. SIGNIFICANCE AND IMPACT OF THE STUDY: We discuss the bacterial community in wild C. cicadae and provide a new way to increase HEA production in C. cicadae by coculture with bacterial strains isolated from wild C. cicadae.


Assuntos
Adenosina/análogos & derivados , Bactérias/isolamento & purificação , Cordyceps/metabolismo , Microbiota , Nucleosídeos/metabolismo , Adenosina/metabolismo , Animais , Bactérias/classificação , Bactérias/genética , Técnicas de Cocultura , RNA Ribossômico 16S/genética
2.
J Biol Regul Homeost Agents ; 31(1): 141-146, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28337883

RESUMO

This study was designed to evaluate the curative effect of conversion from mycophenolate mofetil (MMF) to enteric-coated mycophenolate sodium tablets (EC-MPS) and its safety. One hundred and twenty renal transplant recipients who developed MMF-associated chronic diarrhea were selected as research subjects and treated with EC-MPS. The patients were followed up for 12 months to compare the improvement of gastrointestinal symptoms and the indexes such as carbon dioxide combining power (CO2CP), serum sodium, serum potassium, serum creatinine (Scr) and 24-h urine protein before and after conversion treatment. One hundred and ten of the 120 patients tolerated the conversion treatment and the dose increment of EC-MPS at week 28. After initiating the conversion treatment, the improvement rate of diarrhea within 2 weeks was 95% (114/120). Indexes, such as CO2CP, serum sodium, serum potassium, after conversion treatment were higher than those before treatment (P less than 0.05). No acute rejection reactions were observed in the 12-month follow-up. Indexes of Scr and 24-h urine protein had significant improvement after conversion treatment compared to before conversion treatment (P less than 0.05). Compared to before treatment, the average values of indexes in gastrointestinal symptom rating scale in the 12th month remained stable, except for the increase of dose. For renal transplant recipients who received suboptimal EC-MPS treatment due to gastrointestinal symptoms, conversion from MMF to EC-MPS can significantly lower gastrointestinal symptom load, improve quality of life, relieve electrolyte disturbance and improve the injured functions of transplanted kidney, without increasing the risks of acute rejection reactions.


Assuntos
Diarreia/prevenção & controle , Substituição de Medicamentos , Imunossupressores/efeitos adversos , Transplante de Rim , Ácido Micofenólico/efeitos adversos , Ácido Micofenólico/uso terapêutico , Insuficiência Renal Crônica/sangue , Adulto , Idoso , Doença Crônica , Creatinina/sangue , Diarreia/sangue , Diarreia/induzido quimicamente , Feminino , Rejeição de Enxerto/prevenção & controle , Humanos , Imunossupressores/administração & dosagem , Rim/imunologia , Rim/metabolismo , Rim/patologia , Rim/cirurgia , Masculino , Pessoa de Meia-Idade , Ácido Micofenólico/administração & dosagem , Potássio/sangue , Estudos Prospectivos , Proteinúria/sangue , Insuficiência Renal Crônica/imunologia , Insuficiência Renal Crônica/patologia , Insuficiência Renal Crônica/cirurgia , Sódio/sangue , Comprimidos com Revestimento Entérico
3.
J Biol Regul Homeost Agents ; 30(1): 155-9, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27049086

RESUMO

This study aimed to investigate the effects of Wuzhi capsule on blood concentration of tacrolimus after renal transplantation. Sixty patients after allogenic renal transplantation were enrolled in this study and randomly divided into an experimental group and a control group. One oral Wuzhi capsule was taken in the morning and evening for patients in the experimental group, while none was given to the control group, maintaining the trough blood concentration of tacrolimus in the normal range. After 3 weeks, the changes of tacrolimus dosage and hepatorenal function in the two groups were compared. Comparisons of drug dosage and blood concentration C0 value of tacrolimus before initiating the experiment showed that there was no statistically ignificant difference (P>0.05) between the two groups. The differences of blood concentration of tacrolimus and hepatorenal function for patients in both two groups after 3 weeks’ treatment also showed no statistical significance (P>0.05), whereas a statistically significant decrease was demonstrated in the tacrolimus dosage of the Wuzhi capsule group compared with that of the control group (P=0.0083). After renal transplantation, Wuzhi capsules were added so as to enable tacrolimus to reach a suitable blood concentration, which can prevent the occurrence of renal transplantation rejection, thus alleviating the economic burden of patients and producing larger social benefits.


Assuntos
Medicamentos de Ervas Chinesas/uso terapêutico , Transplante de Rim , Tacrolimo/sangue , Adulto , Relação Dose-Resposta a Droga , Medicamentos de Ervas Chinesas/farmacologia , Feminino , Humanos , Rim/efeitos dos fármacos , Rim/fisiopatologia , Fígado/efeitos dos fármacos , Fígado/fisiopatologia , Masculino , Pessoa de Meia-Idade , Tacrolimo/efeitos adversos , Adulto Jovem
4.
Genet Mol Res ; 15(3)2016 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-27706725

RESUMO

We investigated the effect of pregnane X receptor (PXR) polymorphisms on tacrolimus (FK506) blood trough concentrations and the associated adverse reactions in kidney transplantation recipients (KTRs). Polymerase chain reaction (PCR)-restriction fragment length polymorphism was used to detect the genotypes of single nucleotide polymorphism loci in 336 KTRs. The PXR six-base deletion mutation was classified using specific allele PCR, and the FK506 blood trough concentration in the KTRs was measured by chemiluminescent microparticle immunoassay. There were significant differences in adverse reactions resulting from FK506 in age, weight, body mass index (BMI) and treatment course (P < 0.05). Logistical regression revealed that the FK506 treatment course and BMI were risk factors for hyperlipidemia, and the risk of hyperlipidemia increased 27.534 times when the BMI was less than 18.5. Moreover, age was also a risk factor leading to hyperglycemia. FK506 blood trough concentration and C0/D value had an impact on adverse reactions induced by hyperglycemia. The KTRs' PXR rs3842689, rs6785049, and rs1523127 mutation frequencies were 26.07, 11.79, and 16.07%, respectively. There was no statistically significant difference in the mutation frequency of each locus between the control group and the adverse reaction groups. Therefore, rs3842689, 7635G>A (rs6785049), and 24381C>A (rs1523127) PXR polymorphisms have no obvious impact on FK506; furthermore, the PXR rs3842689 wild-type homozygous WW genotype is a risk factor of FK506 and results in gastrointestinal reactions.


Assuntos
Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/genética , Transplante de Rim/efeitos adversos , Receptores de Esteroides/genética , Tacrolimo/sangue , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Índice de Massa Corporal , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/sangue , Genótipo , Humanos , Imunossupressores/sangue , Masculino , Pessoa de Meia-Idade , Polimorfismo de Nucleotídeo Único , Receptor de Pregnano X , Fatores de Risco , Deleção de Sequência , Tacrolimo/uso terapêutico
5.
Genet Mol Res ; 14(3): 11119-25, 2015 Sep 22.
Artigo em Inglês | MEDLINE | ID: mdl-26400342

RESUMO

We conducted this case-control study to assess the role of the VEGF -2578C/A, +1612G/A, +936C/T and -634G/C gene polymorphisms in the development of renal cell carcinoma (RCC). A hospital-based case-control study was conducted in a 360 consecutive primary RCC patients and 360 age and gender-matched controls during January 2010 and January 2014. The polymerase chain reaction-restriction fragment length polymorphism was used for VEGF -2578C/A, +1612G/A, +936C/T and -634G/C genotyping. Multivariate conditional logistic regression analyses showed that subjects carrying the AA and the CA+AA genotypes of VEGF -2578C/A had significant association with increased risk of RCC compared to those having the CC genotype, and the ORs (95%CI) were 1.77 (1.10-2.85) and 1.37 (1.01-1.86), respectively. Using the conditional logistic regression model, CA+AA genotype of VEGF -2578C/A had a significantly increased risk of RCC in ever cigarette smokers, and individuals with hypertension, and the ORs (95%CI) were 1.93 (1.08-3.45) and 2.57 (1.06-6.57), respectively. In conclusion, our results showed that AA genotype of VEGF -2578C/A genetic variants is associated with increased risk of RCC.


Assuntos
Carcinoma de Células Renais/genética , Neoplasias Renais/genética , Fator A de Crescimento do Endotélio Vascular/genética , Adulto , Estudos de Casos e Controles , Feminino , Frequência do Gene , Estudos de Associação Genética , Predisposição Genética para Doença , Humanos , Masculino , Pessoa de Meia-Idade , Polimorfismo de Nucleotídeo Único , Risco
6.
Eur Rev Med Pharmacol Sci ; 19(2): 284-8, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25683943

RESUMO

OBJECTIVE: CD4+CD25+ regulatory T cells (Tregs) plays a key role in maintaining immune tolerance. IgAN has a close relationship with the immune response. However the significance of CD4+CD25+ T cells to improve renal function of IgAN patients is not clear. The purpose of this study is to evaluate renal function of experimental IgAN rats treated by CD4+CD25+ Tregs cells. MATERIALS AND METHODS: CD4+CD25+ Tregs were separated from the blood of SD rats by immunomagnetic beads, and amplified in vitro. The amplified in vitro and cultured 2*106 CD4+CD25+ Tregs were infused intravenously into IgAN rat model, 3 times every other day. The serum creatinine, urea nitrogen, urinary protein and red blood cells were detected in the fourth and eighth week. The glomerular damage was evaluated by pathological analysis. RESULTS: Tregs cells can be amplified largely in vitro. After CD4+CD25+ T cells were infused into IgAN rat model, urine protein and red blood cells were improved. The glomerular injury can be improved by pathological analysis. CONCLUSIONS: CD4+CD25+ regulatory T cells can significantly improve the symptoms of immunoglobulin A nephropathy (IgAN) rat model, and have clinical application prospect.


Assuntos
Glomerulonefrite por IGA/imunologia , Rim/imunologia , Linfócitos T Reguladores/imunologia , Animais , Glomerulonefrite por IGA/sangue , Glomerulonefrite por IGA/urina , Humanos , Masculino , Ratos , Ratos Sprague-Dawley
7.
J Chromatogr A ; 922(1-2): 283-92, 2001 Jul 13.
Artigo em Inglês | MEDLINE | ID: mdl-11486874

RESUMO

In this report, the moving chemical reaction boundary (MCRB) was formed with the weak acid of acetic acid (HAc) and the strong alkali of NaOH, coupled with the excess of background electrolyte KCl. The experiments were compared with the predictions by the moving chemical reaction boundary equation (MCRBE). It is very interesting that (1) the experimental results are in good agreement with the predictions with the original MCRBE if the MCRB is an anodic moving boundary, (2) however, the experiments are extremely far away from the predictions with the original MCRBE if a cathodic moving boundary. Hence, the original MCRBE must be corrected under the later situation of cathodic moving MCRB. The corrected MCRBE was well quantitatively proved to be valid for the cathodic moving MNRB formed with the same electrolytes of HAc, NaOH and KCl.


Assuntos
Ácidos/química , Álcalis/química , Eletrólitos/química , Cloreto de Potássio/química
8.
J Chromatogr A ; 932(1-2): 13-20, 2001 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-11695858

RESUMO

A new sample introduction method of capillary electrophoresis, in which field-amplified sample injection was combined with a pre-concentration of non-uniform field electrophoresis, is presented in this paper. With an additional pre-concentration voltage applied to sample solution, a non-uniform electric field was generated, with which analytical cations or anions were pre-concentrated around an electrode adjacent to the injection end of capillary. After the pre-concentration, analytical ions were injected into the capillary and stacked at the boundary between sample and buffer solution inside capillary by field-amplified injection technique. In contrast to the conventional field-amplified injection, larger concentration factor and higher analytical sensitivity were obtained with the improved pre-concentration method. Its concentration factor was about 10 approximately 15 fold as that of field-amplified sample injection.


Assuntos
Eletroforese Capilar/métodos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
9.
J Chromatogr A ; 907(1-2): 347-52, 2001 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-11217043

RESUMO

In this report, the moving chemical reaction boundary (MCRB) was formed by the weak reaction electrolytes of NH3.H2O and CH3COOH under the existence of background electrolyte KCl in large concentrations, the experiments were compared with the predictions by the moving chemical reaction boundary equation (MCRBE) for weak reactive electrolytes. It was found that the experimental results are far from the predictions with the MCRBE. So the MCRBEs must be corrected under the given experimental conditions. The corrected MCRBEs are given for the MCRB formed with weak reactive electrolytes coupled with KCl at high concentrations.


Assuntos
Eletrólitos/química , Cloreto de Potássio/química
10.
Sci Total Environ ; 90: 31-9, 1990 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-2305244

RESUMO

Lead levels were determined in 856 blood samples obtained from Beijing citizens who were either factory workers or clerks with no known occupational exposure to heavy metals including lead. Additional analyses were conducted on 74 samples from factory workers in the small city of Jinxi, China. The geometric mean blood lead level (Pb-B) among the general Beijing population 99.2 and 76.1 micrograms 1-1 for non-drinking and non-smoking men and women, respectively, with a statistically significant difference between the two sexes. The effect of drinking was not detectable, whereas that of smoking was suggested, but not conclusive. The Pb-B levels among Jinxi workers did not differ from the levels among Beijing citizens. The Pb-B for inhabitants of Beijing was similar to the levels of inhabitants of a medium-sized city, Hefei, and lower than the values for residents of two heavily industrialized large cities, Shanghai and Shenyang. The values for Chinese citizens appear to be higher than those for Japanese and Korean farmers, but the possibility of urban-rural differences remains to be examined.


Assuntos
Chumbo/sangue , Adolescente , Adulto , Fatores Etários , Consumo de Bebidas Alcoólicas , China , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fatores Sexuais , Fumar/efeitos adversos , Saúde da População Urbana
11.
Biomed Environ Sci ; 2(1): 72-7, 1989 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-2556157

RESUMO

Trinitrotoluene (TNT) increased the formation of adrenochrome from adrenaline and the formation of formaldehyde from methanol in rat liver mitochondria and microsomes in vitro as well as in monkey liver mitochondria and microsomes in vivo. The effects were more prominent at higher TNT concentrations. These findings indicate that TNT enhances the production of superoxide radicals (O2) and hydrogen peroxide (H2O2). The production of O2 was more prominent in systems containing added TNT than in those containing added benzyl viologen. H2O2 production by mitochondria was more pronounced in the liver than in other organs, but its production by microsomes was more pronounced in the brain than in other organs. The results suggest that TNT undergoes cycling reduction which produces oxidative stress.


Assuntos
Peróxido de Hidrogênio/metabolismo , Fígado/efeitos dos fármacos , Superóxidos/metabolismo , Trinitrotolueno/farmacologia , Animais , Encéfalo/metabolismo , Técnicas In Vitro , Rim/metabolismo , Fígado/metabolismo , Macaca mulatta , Masculino , Microssomos/metabolismo , Mitocôndrias/metabolismo , Ratos , Ratos Endogâmicos , Testículo/metabolismo
12.
Am J Physiol ; 268(4 Pt 1): L558-64, 1995 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-7733298

RESUMO

Intracellular free Ca2+ ([Ca2+]i) plays a vital role both in maintaining normal cellular function and in cell killing. Few studies have been published regarding its role in ozone (O3)-induced health effects. This study investigated the effect and mechanism of O3 exposure on [Ca2+]i in human tracheal epithelial (HTE) cells. HTE cells grown on Costar Transwell inserts with a liquid-gas interface were exposed to 0, 0.05, 0.1, 0.2 and 0.4 ppm O3 at 37 degrees C for 1 h. After exposure, [Ca2+]i was measured using the fluorescent dye Fluo 3. O3 at 0.4 ppm produced a significant increase in [Ca2+]i, and the increases in [Ca2+]i were blocked by verapamil and 8-(diethylamino)-octyl-3,4,5,-trimethoxybenzoate (TMB-8). These results suggest that the O3-induced [Ca2+]i elevation may involve both Ca2+ release from internal stores and Ca2+ influx across the plasma membrane. Furthermore, both buffer and cell lysate of HTE cells exposed to 0.4 ppm O3 caused a rapid increase in [Ca2+]i of THP-1 human phagocytic monocytes, but the buffer and lysate from air exposed cells did not. These results suggest that O3 exposure causes HTE cells to release a diffusible mediator from the empty Ca(2+)-storing organelle and may be responsible for the sustained and persistent [Ca2+]i elevation in HTE cells exposed to 0.4 ppm O3.


Assuntos
Cálcio/metabolismo , Mediadores da Inflamação/metabolismo , Ozônio/farmacologia , Traqueia/efeitos dos fármacos , Traqueia/metabolismo , Bloqueadores dos Canais de Cálcio/farmacologia , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Células Epiteliais , Epitélio/efeitos dos fármacos , Epitélio/metabolismo , Ácido Gálico/análogos & derivados , Ácido Gálico/farmacologia , Humanos , Membranas Intracelulares/metabolismo , Monócitos/metabolismo , Concentração Osmolar , Fagócitos/metabolismo , Traqueia/citologia , Verapamil/farmacologia
13.
Toxicol Appl Pharmacol ; 121(1): 138-43, 1993 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-8393219

RESUMO

In vivo exposure to sulfuric acid aerosols produces profound effects on pulmonary macrophage (PM phi) phagocytic function and cytokine release and perturbs intracellular pH (pHi) homeostasis. Because pHi influences a multitude of cellular processes, we sought to investigate the mechanism by which acid aerosol exposure affects its regulation. Guinea pigs underwent a single or 5 repeated 3-hr exposures to sulfuric acid aerosol (969 and 974 micrograms/m3 for single and repeated exposures, respectively). PM phi harvested immediately after exposure were incubated in HCO3-free media and their pHi recovery from an intracellular acid load was examined. The overall pHi recovery was depressed after single and multiple exposures to sulfuric acid aerosol. delta pHi (the difference between initial pHi and the one measured at 150 sec) decreased by 15.6 and 23.3% (p < 0.05) for single and repeated exposures, respectively. Initial dpHi/dt (maximum pHi recovery rate) after cytoplasmic acidification diminished by 20.3 and 32.2%, which were not statistically significant (p = 0.08 for repeated exposure). To determine whether the activity of the H(+)-ATPase pump the Na(+)-H+ exchanger was specifically altered by the acid exposures, PM phi were first incubated in Na+ and HCO3-free media with NBD-Cl (7-chloro-4-nitrobenz-2-oxa-1,3-diazol, blocking H(+)-ATPase and leaving only the Na(+)-H+ exchanger in effect) and then challenged with 30 mM NaCl. The pHi recovery of PM phi after Na challenge was significantly reduced in acid aerosol exposed guinea pigs (p < 0.05) compared to controls (for delta pHi, 18.2% lower in single exposure and 22.7% in multiple exposure groups; for initial dpHi/dt, 26.9% lower in single exposure and 22.4% in multiple exposure groups). In contrast, the H(+)-ATPase pump was inconsistently affected as indicated by delta pHi and initial dpHi/dt measured in the presence of MIA (amiloride-5-N-methylisobutyl, inhibiting the Na(+)-H+ exchanger and leaving only the H(+)-ATPase pump in effect). These results suggest that in vivo exposure to sulfuric acid aerosols induces alterations in pHi regulation in guinea pig PM phi attributable to changes in Na(+)-H+ exchanger activity.


Assuntos
Líquido da Lavagem Broncoalveolar/citologia , Proteínas de Transporte/metabolismo , Macrófagos Alveolares/efeitos dos fármacos , ATPases Translocadoras de Prótons/metabolismo , Ácidos Sulfúricos/toxicidade , Administração por Inalação , Aerossóis , Animais , Sobrevivência Celular/efeitos dos fármacos , Cobaias , Concentração de Íons de Hidrogênio , Macrófagos Alveolares/metabolismo , Masculino , Trocadores de Sódio-Hidrogênio , Ácidos Sulfúricos/administração & dosagem
14.
Toxicol Appl Pharmacol ; 113(1): 109-17, 1992 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-1553743

RESUMO

Acidic sulfate is the most toxicologically important sulfur oxide which exists in the ambient air. To determine if particle size influences toxic effects of sulfuric acid, we investigated the effects of sulfuric acid aerosols of two different sizes on biochemical and cellular parameters of bronchoalveolar lavage fluid from exposed guinea pigs. Guinea pigs were exposed to fine (mass median diameter, 0.3 micron), and ultrafine (mass median diameter, 0.04 micron) sulfuric acid aerosols at 300 micrograms/m3 for 3 hr/day. The animals were euthanized immediately and 24 hr after 1 and 4 days of exposure and lungs were lavaged. Elevated beta-glucuronidase, lactate dehydrogenase activities, and total protein concentration as well as decreased cell viability were observed in the lavage after a single exposure to sulfuric acid aerosols of both sizes. These alterations were small, though statistically significant, and transient. No alteration in these parameters was observed after 4 days of exposure to acid aerosols. In contrast, sulfuric acid-induced alterations in alveolar macrophage function were more pronounced and longer lasting. Immediately after a single exposure to fine acid, there was a 2.7-fold increase in the spontaneous tumor necrosis factor (TNF) release over that in the control group while endotoxin-stimulated TNF release was increased by 2.2-fold. In addition, acid aerosols of both sizes increased the TNF release from macrophages after 4 days of exposure, although there was no clear temporal pattern of induction or recovery. Furthermore, immediately after 4 days of exposure to either fine or ultrafine acid, the amount of H2O2 that could be induced from baseline production by alveolar macrophages was 2.2-fold higher than that of the controls. The phagocytic function of macrophages was also altered by exposure to sulfuric acid aerosols. Twenty-four hours after single or multiple exposure, fine acid enhanced (as high as 78% above control) the in vitro phagocytic activity of alveolar macrophages while ultrafine acid depressed the phagocytic capacity (as much as 50% below that in the control). In addition to these biochemical parameters and cellular functions, we also measured the intracellular pH (pHi) of macrophages harvested after exposures to these acid aerosols using a pH-sensitive fluorescent dye. The resting pHi was depressed after a single exposure to both acid aerosols. The depression in pHi persisted 24 hr after ultrafine acid exposure.(ABSTRACT TRUNCATED AT 400 WORDS)


Assuntos
Líquido da Lavagem Broncoalveolar/química , Macrófagos Alveolares/efeitos dos fármacos , Ácidos Sulfúricos/toxicidade , Aerossóis , Animais , Cobaias , Peróxido de Hidrogênio/isolamento & purificação , Concentração de Íons de Hidrogênio , Macrófagos Alveolares/metabolismo , Masculino , Tamanho da Partícula , Fagocitose/efeitos dos fármacos , Ácidos Sulfúricos/administração & dosagem , Fator de Necrose Tumoral alfa/isolamento & purificação
15.
Fundam Appl Toxicol ; 20(2): 170-6, 1993 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-8449388

RESUMO

While ambient acid aerosols are considered a potential respiratory health hazard, the mechanism by which they induce responses in the lungs is not known. Attempts to ascertain these mechanisms using inhalation exposures are complicated by a number of technical difficulties, chief among which are neutralization of inhaled acids by endogenous ammonia and variations in deposition with inhaled particle size. To control for these variables, a novel in vitro exposure system allowing experimental evaluation of factors which influence biologic responses to acid sulfate particles was developed. The system consists of two subunits, a generation/delivery component and a cell exposure component. Sulfuric acid aerosols are generated by nebulizing dilute acid solutions. Particles larger than a specified size of interest (based upon the specific exposure conditions desired) are removed, and particles at the desired size and mass concentration are uniformly delivered onto a target cell monolayer. The system is capable of delivering acid particles larger than 0.7 micron (mass median diameter), yet at constant particle mass concentrations. This paper describes the design of the exposure system and its performance characteristics and presents initial results of some biological responses obtained using it. In conjunction with inhalation studies, this exposure system may provide additional insights into mechanisms by which acid aerosols adversely affect the respiratory tract and into the physical characteristics of acid particles which modulate toxicity.


Assuntos
Pulmão/efeitos dos fármacos , Ácidos Sulfúricos/toxicidade , Aerossóis , Permeabilidade da Membrana Celular/fisiologia , Células Cultivadas , Meios de Cultura , Células Epiteliais , Fibronectinas , Humanos , Líquido Intracelular/metabolismo , Pulmão/citologia , Concentração Osmolar , Tamanho da Partícula , Ácidos Sulfúricos/administração & dosagem , Traqueia/citologia , Traqueia/efeitos dos fármacos
16.
Am Ind Hyg Assoc J ; 53(4): 221-7, 1992 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-1529913

RESUMO

A transportable Fourier transform infrared (FTIR) spectrometer has been tested for analysis of methanol vapor in alveolar and ambient air. The instrument has been found to be accurate and precise for both uses. The regions used for methanol and CO2 quantification are in the vicinity of 950-1100 cm-1 and 2000-2100 cm-1, respectively. The results of a standard addition experiment show a correlation coefficient of 0.97-0.99 for methanol in alveolar or ambient air at the 30-200 ppm concentration level. For CO2 analysis in 23 alveolar air samples at the 6.1-7.6% concentration level, the mean difference in results between a nondispersive infrared (NDIR) spectrometer and the FTIR was -0.092% with a standard deviation of 0.273% (p greater than 0.1). Methanol concentrations in alveolar air paralleled simultaneous measurements of methanol concentration in blood. Overall, these preliminary results suggest that FTIR spectroscopy is a practical and efficient approach for simultaneous biological and area monitoring of human exposure to organic solvents.


Assuntos
Poluentes Atmosféricos/análise , Testes Respiratórios , Metanol/análise , Espectrofotometria Infravermelho/instrumentação , Dióxido de Carbono/análise , Exposição Ambiental , Análise de Fourier , Humanos , Metanol/sangue , Alvéolos Pulmonares , Respiração , Espectrofotometria Infravermelho/métodos
17.
Se Pu ; 19(2): 176-8, 2001 Mar.
Artigo em Zh | MEDLINE | ID: mdl-12541669

RESUMO

A sampling preconcentration method combining electrostacking with isotachophoresis is presented in this paper. The optimum conditions for electrostacking and isotachophoresis were investigated. With the preconcentration conditions of 70 s electrostacking and 40 s isotachophoresis, two medicines, propranolol and metoprolol, with similar structures were separated by capillary zone electrophoresis. The working voltage for all the steps was 15 kV. Being adjusted to pH 4.0, 30 mmol/L NaAc-HAc, 30 mmol/L beta-alanine-HAc and 1.5 mmol/L NaAc-HAc were employed as the background, viz. leading, terminating and sample buffer solutions respectively. In comparing with the conventional electro-migration injection, the enhancement factors in peak height of the present method were about 250 and 160 for propranolol and metoprolol respectively. Total analysis time was similar to that of the conventional one.


Assuntos
Eletroforese Capilar/métodos , Metoprolol/isolamento & purificação , Propranolol/isolamento & purificação , Eletrólitos , Eletroforese/métodos , Manejo de Espécimes/métodos
18.
Talanta ; 55(2): 271-9, 2001 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-18968370

RESUMO

An electrokinetic flow analysis system (EKFA) using an electroosmotic pump (Peo) and a bi-directional electrostacking (BDES) unit is introduced in this paper. Large flow range, moderate carrier pressure, low performance voltage and stable flow rate, especially in mulmin(-1) level, are the main specialties of the Peo. Diethanolamine, 0.5 mM, is selected as its carrier to improve the pump efficiency and stability further. Moreover, BDES, a feasibility investigation for the simultaneous separation and pre-concentration of cations and anions, and graphite furnace atomic absorption spectrometry (GFAAS) determination are presented. The calibration series for both of Cr(VI) and Pb(II) are from 0.2 to 40 mugl(-1) with 10 mul pipette volume and GFAAS determination directly. The detection limit of Cr(VI) and Pb(II) with 10 min BDES is 10 and 13 ngl(-1)(3sigma of blank, n=11), respectively. The recovery of Cr(VI) and Pb(II) is (103-105)+/-1% and (95.9-96.9)+/-1.0% with three independent determinations, respectively. The investigated method is also suitable for the simultaneous separation and pre-concentration of trace cations and anions in low conductivity sample solutions with different detection instruments.

19.
Int Arch Occup Environ Health ; 64(7): 533-9, 1993.
Artigo em Inglês | MEDLINE | ID: mdl-8482596

RESUMO

The correlation between exposure to three xylene isomers and resulting urinary excretion of corresponding methylhippuric acid (MHA) isomers was studied among 175 Chinese workers of both sexes who had been predominantly exposed to xylenes (exposure to xylenes accounting for 70% or more of the total exposure on a ppm basis). Nonexposed controls (281 men and women) were also studied to define the background level of MHAs in urine. The solvent exposure of xylene-exposed workers during their workshift was monitored by diffusive sampling of breathing zone air, and MHAs in shift-end urine were determined by high-performance liquid chromatography. Regression analysis showed that the concentration of each MHA isomer correlated significantly with the time-weighted average intensity of exposure to the corresponding xylene isomer, and therefore the correlation between the sum of three xylene isomers in air and that of three MHA isomers in urine was also significant; the slope of the regression line was essentially the same among the three isomers. The calculated regression line suggested that the urinary MHA level after hypothetical exposure to xylenes at 100 ppm will be somewhat less than the proposed biological exposure index and biological tolerance value. Two social habits of smoking and drinking in combination suppressed the conversion of xylenes to MHAs in male workers.


Assuntos
Hipuratos/urina , Exposição Ocupacional/efeitos adversos , Tolueno/efeitos adversos , Xilenos/efeitos adversos , Adulto , Feminino , Humanos , Masculino , Análise de Regressão
20.
Int Arch Occup Environ Health ; 64(2): 113-7, 1992.
Artigo em Inglês | MEDLINE | ID: mdl-1399020

RESUMO

Possible color vision loss was examined with Lanthony's new color test and Ishihara's color vision test in 261 solvent workers and 120 controls (48 men and 72 women). The solvent workers were exposed to either predominantly toluene [46 ppm as geometric mean (GM); 63 men and 111 women], tetrachloroethylene alone (13 ppm; 30 men and 34 women), or a mixture (14 men and 9 women) of tetrachloroethylene (12 ppm) and trichloroethylene (7 ppm). The only instances of color vision loss that were detected in either the exposed workers or the controls were six cases of red-green loss (all in men). These six cases of red-green loss showed an unbiased distribution between the exposed workers and the nonexposed controls.


Assuntos
Indústria Química , Defeitos da Visão Cromática/etiologia , Solventes/efeitos adversos , Tetracloroetileno/efeitos adversos , Tolueno/efeitos adversos , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Exposição Ocupacional/análise , Exposição Ocupacional/normas , Solventes/análise , Tetracloroetileno/análise , Tolueno/análise
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