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2.
Int J STD AIDS ; : 956462416628782, 2016 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-26787639

RESUMEN

The second British Association for Sexual Health and HIV Oxford Diagnostics Course of 2015 focussed on recent challenges and emerging concepts within diagnostics and service design. In response to increasing sexually transmitted infection rates and subsequent demand on UK sexual health services, multiple approaches to improving patient flow and reducing waiting times were presented. The value of novel remote sexually transmitted infection testing was explored, with a description of the patient journey, emerging demographics and rates of testing uptake for the UK's leading National Health Service provider. A cost-benefit evaluation was made for the use of nucleic acid amplification tests versus traditional microscopy and culture for detecting Trichomonas vaginalis, with practical consideration of application to higher risk groups. Two speakers stressed the importance of vigilance against growing antimicrobial resistance. The significance of testing for genotypic markers for antimicrobial resistance, and the emergence of point-of-care tests for resistance were also presented. The meeting closed with a first-hand account of tendering, and practical advice on rebuilding professional relationships and services after a competitive process.

3.
Int J STD AIDS ; 25(5): 360-2, 2014 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-24047881

RESUMEN

Effective asymptomatic screening for sexually transmitted infections is an important public health service because a significant proportion of sexually transmitted infections do not present with symptoms. In 2009, the National Audit Group of the British Association of Sexual Health and HIV (BASHH) audited the management of asymptomatic patients and recommended increased documentation about oral and anal sex, regional strategies for nucleic acid amplification test (NAAT) use for gonorrhoea, improved screening for hepatitis B in men who have sex with men and an increase in screening for HIV. The 2012 audit used web-based forms to collect submissions from 180 consultant-led centres (65% response rate) that included episodes of care from 6669 asymptomatic patients. An improvement was demonstrated for all the areas measured during the 2009 audit. A doubling of gonorrhoea testing using NAATs was seen and yet 10% of asymptomatic patients continued to have microscopy despite these tests not being recommended by BASHH guidelines. This audit recommends universal adoption of gonorrhoea NAATs across the United Kingdom.


Asunto(s)
Tamizaje Masivo/métodos , Auditoría Médica , Anamnesis , Técnicas de Amplificación de Ácido Nucleico/métodos , Enfermedades de Transmisión Sexual/diagnóstico , Infecciones por Chlamydia/diagnóstico , Chlamydia trachomatis , Femenino , Gonorrea/diagnóstico , Infecciones por VIH/diagnóstico , Investigación sobre Servicios de Salud , Humanos , Masculino , Neisseria gonorrhoeae , Salud Reproductiva , Reino Unido
4.
Sex Transm Infect ; 86(7): 540-4, 2010 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-20656723

RESUMEN

BACKGROUND: Increasing access to sexual health services is a key objective for the Department of Health in England and Wales. In 2006 it published 10 high-impact changes (HICs) designed to enhance 48 h access to genitourinary medicine services. However, there is limited evidence on the effectiveness of the proposed interventions. OBJECTIVE: To evaluate the implementation of five HICs in three sexual health clinics over 4 years. These HICs included a text message results service, nurse-delivered asymptomatic service, clinic refurbishment, a centralised booking service and an electronic appointment system. METHODS: The effect of HICs was evaluated by measuring clinical activity, number of sexual health screens performed, and patients seen within 48 h. These data were obtained from the clinic database, mandatory reports and Health Protection Agency waiting time surveys, respectively. RESULTS: The median number of new patients seen per month increased from 3635 to 4263 following the implementation of the five HICs. The follow-up/new patient ratio fell from 0.67 to 0.21 during the study. The biggest fall corresponded to a rise in patients receiving results by text message, from 0% to 40%. Only the centralised booking service was associated with a significant increase in the number of new patients seen. DISCUSSION: Providing results by text message was associated with a reduced number of follow-up patients, while implementation of a centralised booking service coincided with a significant increase in patient access. Further research is required to evaluate the relative importance of the other HICs.


Asunto(s)
Atención Ambulatoria/organización & administración , Accesibilidad a los Servicios de Salud/organización & administración , Enfermedades de Transmisión Sexual/terapia , Atención Ambulatoria/estadística & datos numéricos , Citas y Horarios , Accesibilidad a los Servicios de Salud/estadística & datos numéricos , Humanos , Londres , Atención de Enfermería/organización & administración , Atención de Enfermería/estadística & datos numéricos , Evaluación de Programas y Proyectos de Salud
5.
Int J STD AIDS ; 20(3): 196-9, 2009 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-19255270

RESUMEN

Rising heterosexual syphilis in south London in 2002 prompted Local Enhanced Syphilis Surveillance (LESS) in five of the 10 genitourinary medicine clinics. LESS reported a fall in heterosexual infectious syphilis in 2004 that was corroborated by the National Enhanced Syphilis Surveillance (NESS). However, mandatory clinic Korner Codes 60 (KC60) coding did not support the reported fall; therefore database discrepancies were evaluated. Three databases (KC60, NESS and LESS) were compared in 2004 at selected clinics using clinical notes as the reference. Six clinics participated in NESS. Four clinics participated in both LESS and NESS and three of these clinics were visited. Only 48% (79 of 163) of KC60 infectious syphilis cases were heterosexual, 36% (58 of 163) were men who have sex with men and the rest were incorrectly coded. The NESS and LESS databases captured 80% and 68% of the confirmed heterosexual syphilis cases, respectively. Despite the inaccuracy in mandatory KC60 returns, this surveillance system captured additional heterosexual syphilis cases.


Asunto(s)
Notificación de Enfermedades/estadística & datos numéricos , Brotes de Enfermedades/estadística & datos numéricos , Vigilancia de la Población/métodos , Sífilis/epidemiología , Instituciones de Atención Ambulatoria , Femenino , Humanos , Londres/epidemiología , Masculino
6.
Br J Pharmacol ; 154(6): 1318-26, 2008 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-18500358

RESUMEN

BACKGROUND AND PURPOSE: Endothelial cell activation plays a critical role in regulating leukocyte recruitment during inflammation and infection. Ethanol (EtOH) reduces host defence systems, including cell adhesion. However, well-known side effects of EtOH limit its clinical use as an anti-inflammatory drug. Instead, ethyl pyruvate (EtP) may represent a better alternative. Here, we compared effects of EtP and EtOH on neutrophil recruitment and activation of human umbilical vein endothelial cells (HUVECs). EXPERIMENTAL APPROACH: Adhesion of neutrophils to HUVEC monolayers, surface expression of intercellular cell adhesion molecule, E-selectin, vascular cell adhesion molecule, release of interleukin (IL)-8 and granulocyte colony-stimulating factor (G-CSF) from HUVECs were assessed as well as translocation of interleukin-1 receptor-associated kinase (IRAK-1), the nuclear factor-kappa B (NF-kappaB) subunits p50, p65 and IkappaB-alpha. NF-kappaB activation was analysed with a luciferase reporter plasmid. Cells were stimulated with IL-1beta, lipopolysaccharide (LPS) or tumour necrosis factor-alpha. KEY RESULTS: EtP was several-fold more potent than EtOH in reducing adhesion of neutrophils to activated HUVECs, generation of IL-8 or G-CSF and surface expression of the adhesion molecules. This last reaction was decreased by EtP even when added after cytokines or LPS. Translocation of IRAK-1, IkappaBalpha and the NF-kappaB p65 subunit to the HUVEC nucleus was inhibited by EtP for all stimuli, whereas the diminished p50 translocation was stimulus specific. When p65 was constitutively expressed in Cos7 cells, stimulation of an NF-kappaB-dependent reporter gene was not affected by EtP, suggesting that EtP acted upstream of gene activation. CONCLUSIONS AND IMPLICATIONS: EtP impedes adhesive, secretory and signalling events typical of the early inflammatory response in endothelial cells, suggesting EtP as a possible treatment for acute inflammatory conditions.


Asunto(s)
Células Endoteliales/patología , Inflamación/fisiopatología , FN-kappa B/fisiología , Piruvatos/farmacología , Transducción de Señal/fisiología , Animales , Biomarcadores , Células COS , Adhesión Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Células Cultivadas , Chlorocebus aethiops , Citocinas/metabolismo , Selectina E/biosíntesis , Factor Estimulante de Colonias de Granulocitos/metabolismo , Humanos , Quinasas Asociadas a Receptores de Interleucina-1/metabolismo , Interleucina-1beta/farmacología , Lipopolisacáridos/farmacología , Neutrófilos/efectos de los fármacos , Neutrófilos/patología , Plásmidos/genética , Transducción de Señal/efectos de los fármacos , Transfección , Factor de Necrosis Tumoral alfa/farmacología
8.
Sex Transm Infect ; 82(1): 49-51, 2006 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-16461603

RESUMEN

OBJECTIVE: To assess the effectiveness of a text message result service within an inner London sexual health clinic. METHOD: Demographic data, diagnoses, and time to diagnosis and treatment were collected over a 6 month period for patients receiving text messages and a matched standard recall group. Data on messages sent, staff time, and cost in relation to result provision were collected. RESULTS: Over a 6 month period 952 text messages were sent. In the final month of analysis, 33.9% of all clinic results were provided by text, resulting in a saving of 46 hours of staff time per month. 49 messages requested that the patient return for treatment, 28 of these patients had untreated genital Chlamydia trachomatis (CT) infection. The mean number of days (SD) to diagnosis was significantly shorter in the text message group (TG) v the standard recall group (SG) (7.9 (3.6) v 11.2 (4.7), p <0.001). The median time to treatment was 8.5 days (range 4-27 days) for the TG group v 15.0 (range 7-35) for SG, p = 0.005. CONCLUSION: Patients with genital CT infection are diagnosed and receive treatment sooner since the introduction of a text message result service. The introduction of this service has resulted in a significant saving in staff time.


Asunto(s)
Teléfono Celular , Infecciones por Chlamydia/diagnóstico , Comunicación , Adulto , Infecciones por Chlamydia/terapia , Chlamydia trachomatis , Femenino , Humanos , Masculino , Factores de Tiempo
9.
Int J STD AIDS ; 16(12): 799-801, 2005 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-16336761

RESUMEN

Our objective was to estimate Chlamydia trachomatis (CT) genital infection point prevalence in young male inmates using a non-invasive sampling technique. All new inmates were invited into the study that consisted of a questionnaire and the provision of a urine sample for analysis. The questionnaire asked about personal characteristics, sexual history and symptoms. CT was diagnosed using nucleic acid amplification tests. In all, 13% of new inmates were found to have CT infection. One-fifth of these CT-positive individuals had symptoms of urethral infection. CT prevalence among young male inmates is comparable with results obtained from young women in UK screening programmes. Numerous factors support the integration of CT screening in prisons into the national chlamydia screening programme.


Asunto(s)
Infecciones por Chlamydia/epidemiología , Chlamydia trachomatis , Adolescente , Infecciones por Chlamydia/prevención & control , Humanos , Masculino , Tamizaje Masivo , Prevalencia , Prisiones , Encuestas y Cuestionarios , Reino Unido/epidemiología
10.
Scand J Immunol ; 60(6): 566-73, 2004 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-15584967

RESUMEN

The nuclear protein high-mobility group box chromosomal protein 1 (HMGB1) was recently described to act as a pro-inflammatory cytokine and as a late mediator of severe sepsis and septic shock. The protein is released from monocytes in response to endotoxin and activates monocytes and endothelial cells through nuclear factor kappa B. We have previously demonstrated that the B-box of HMGB1 mediates a pro-inflammatory effect on endothelial cells including the upregulation of cell-adhesion molecules and release of interleukin (IL)-8 and granulocyte colony-stimulating factor. Here, we report that HMGB1 is released from human umbilical vein endothelial cells (HUVEC) in response to lipopolysaccharide (LPS) and tumour necrosis factor (TNF)-alpha. A nuclear relocation of HMGB1 to the cytoplasm was seen at 4 h. Subsequently, high amounts of HMGB1 could be seen in the supernatants from stimulated cells after 16 h. It was also observed that the pro-inflammatory activity of HMGB1 is sensitive to dexamethasone. Interestingly, the HMGB1-induced TNF-alpha release from monocytes could be inhibited by either the A-box of the protein or the p38 inhibitor CNI-1493, but neither had any inhibitory effects on the HMGB1-dependent upregulation of cell-adhesion molecules on HUVEC. Altogether, these results suggest that HUVEC may be an important source of HMGB1 secretion in response to systemic infection and that endothelial cells and monocytes may use different signalling pathways.


Asunto(s)
Células Endoteliales/metabolismo , Proteína HMGB1/metabolismo , Neutrófilos/efectos de los fármacos , Venas Umbilicales/metabolismo , Adhesión Celular/efectos de los fármacos , Dexametasona/farmacología , Células Endoteliales/efectos de los fármacos , Células Endoteliales/inmunología , Glucocorticoides/farmacología , Humanos , Hidrazonas/farmacología , Inmunosupresores/farmacología , Lipopolisacáridos/inmunología , Monocitos/efectos de los fármacos , Transporte de Proteínas , Factor de Necrosis Tumoral alfa/inmunología , Venas Umbilicales/inmunología
12.
J Intern Med ; 254(4): 375-85, 2003 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-12974876

RESUMEN

OBJECTIVES: Severe sepsis and septic shock is a consequence of a generalized inflammatory systemic response because of an invasive infection that may result in acute organ dysfunction. Mortality is high despite access to modern intensive care units. The nuclear DNA binding protein high mobility group 1 (HMGB1) protein has recently been suggested to act as a late mediator of septic shock via its function as a macrophage-derived pro-inflammatory cytokine (J Exp Med 2000; 192: 565, Science1999; 285: 248). We investigated the pro-inflammatory activities of the A-box and the B-box of HMGB1 on human umbilical venular endothelial cells (HUVEC). DESIGN: The HUVEC obtained from healthy donors were used for experiments. Recombinant human full-length HMGB1, A-box and B-box were cloned by polymerase chain reaction (PCR) amplification from a human brain quick-clone cDNA. The activation of HUVEC was studied regarding (i) upregulation of adhesion molecules, (ii) the release of cytokines and chemokines, (iii) the adhesion of neutrophils to HUVEC, (iv) the activation of signalling transduction pathways and (v) the involvement of the receptor for advanced glycation end-products (RAGE). RESULTS: The full-length protein and the B-box of HMGB1 dose-dependently activate HUVEC to upregulate adhesion molecules such as ICAM-1, VCAM-1 and E-selectin and to release IL-8 and G-CSF. The activation of HUVEC could be inhibited to 50% by antibodies directed towards the RAGE. HMGB1-mediated HUVEC stimulation resulted in phosphorylation of the ELK-1 signal transduction protein and a nuclear translocation of p65 plus c-Rel, suggesting that HMGB1 signalling is regulated in endothelial cells through NF-kappaB. CONCLUSIONS: The HMGB1 acts as a potent pro-inflammatory cytokine on HUVEC and the activity is mainly mediated through the B-box of the protein. HMGB1 may be a key factor mediating part of the pro-inflammatory response occurring in septic shock and severe inflammation.


Asunto(s)
Endotelio Vascular/efectos de los fármacos , Proteína HMGB1/farmacología , Proteínas Recombinantes/farmacología , Western Blotting/métodos , Moléculas de Adhesión Celular/análisis , Células Cultivadas , Citocinas/biosíntesis , Selectina E/genética , Humanos , Inflamación/fisiopatología , Molécula 1 de Adhesión Intercelular/análisis , FN-kappa B/genética , Neutrófilos/fisiología , Reacción en Cadena de la Polimerasa/métodos , Sepsis/fisiopatología , Transducción de Señal/fisiología , Translocación Genética/genética , Molécula 1 de Adhesión Celular Vascular/análisis
13.
J AOAC Int ; 84(3): 770-6, 2001.
Artículo en Inglés | MEDLINE | ID: mdl-11417641

RESUMEN

The statistical distribution known as the compound gamma function was studied for suitability in describing the distribution of sample test results associated with testing lots of shelled corn for fumonisin. Thirty-two 1.1 kg test samples were taken from each of 16 contaminated lots of shelled corn. An observed distribution consisted of 32 sample fumonisin test results for each lot. The mean fumonisin concentration, c, and the variance, s2, among the 32 sample fumonisin test results along with the parameters for the compound gamma function were determined for each of the 16 observed distributions. The 16 observed distributions of sample fumonisin test results were compared with the compound gamma function using the Power Divergence test. The null hypothesis that the observed distribution could have resulted from sampling a family of compound gamma distributions was not rejected at the 5% significance level for 15 of the 16 lots studied. Parameters of the compound gamma distribution were calculated from the 32-fumonisin sample test results using the method of moments. Using regression analysis, equations were developed that related the parameters of the compound gamma distribution to fumonisin concentration and the variance associated with a fumonisin test procedure. An operating characteristic curve was developed for a fumonisin sampling plan to demonstrate the use of the compound gamma function.


Asunto(s)
Ácidos Carboxílicos/análisis , Contaminación de Alimentos , Fumonisinas , Micotoxinas/análisis , Zea mays/química , Cromatografía Liquida , Contaminación de Alimentos/estadística & datos numéricos , Análisis de Regresión , Estadística como Asunto
14.
J Biol Chem ; 276(35): 33061-5, 2001 Aug 31.
Artículo en Inglés | MEDLINE | ID: mdl-11418619

RESUMEN

The cDNA of a novel human glutathione transferase (GST) of the Alpha class was cloned, and the corresponding protein, denoted GST A3-3, was heterologously expressed and characterized. GST A3-3 was found to efficiently catalyze obligatory double-bond isomerizations of Delta(5)-androstene-3,17-dione and Delta(5)-pregnene-3,20-dione, precursors to testosterone and progesterone, respectively, in steroid hormone biosynthesis. The catalytic efficiency (k(cat)/K(m)) with Delta(5)-androstene-3,17-dione was determined as 5 x 10(6) m(-1) s(-1), which is considerably higher than with any other GST substrate tested. The rate of acceleration afforded by GST A3-3 is 6 x 10(8) based on the ratio between k(cat) and the rate constant for the nonenzymatic isomerization of Delta(5)-androstene-3,17-dione. Besides being high in absolute numbers, the k(cat)/K(m) value of GST A3-3 exceeds by a factor of approximately 230 that of 3beta-hydroxysteroid dehydrogenase/isomerase, the enzyme generally considered to catalyze the Delta(5)-Delta(4) double-bond isomerization. Furthermore, GSTA3-specific polymerase chain reaction analysis of cDNA libraries from various tissues showed a message only in those characterized by active steroid hormone biosynthesis, indicating a selective expression of GST A3-3 in these tissues. Based on this finding and the high activity with steroid substrates, we propose that GST A3-3 has evolved to catalyze isomerization reactions that contribute to the biosynthesis of steroid hormones.


Asunto(s)
Glutatión Transferasa/química , Glutatión Transferasa/metabolismo , Isoenzimas/química , Isoenzimas/metabolismo , Esteroides/biosíntesis , Secuencia de Aminoácidos , Clonación Molecular , Escherichia coli , Biblioteca de Genes , Glutatión Transferasa/genética , Hormonas/biosíntesis , Humanos , Isoenzimas/genética , Cinética , Datos de Secuencia Molecular , Proteínas Recombinantes/metabolismo , Alineación de Secuencia , Homología de Secuencia de Aminoácido , Esteroide Isomerasas/metabolismo , Especificidad por Sustrato
15.
J AOAC Int ; 83(5): 1270-8, 2000.
Artículo en Inglés | MEDLINE | ID: mdl-11048872

RESUMEN

The suitability of several theoretical distributions to predict the observed distribution of aflatoxin test results in shelled corn was investigated. Fifteen positively skewed theoretical distributions were each fitted to 18 empirical distributions of aflatoxin test results for shelled corn. The compound gamma distribution was selected to model aflatoxin test results for shelled corn. The method of moments technique was chosen to estimate the parameters of the compound gamma distribution. Mathematical expressions were developed to calculate the parameters of the compound gamma distribution for any lot aflatoxin concentration and test procedure. Observed acceptance probabilities were compared to operating characteristic curves predicted from the compound gamma distribution, and all 18 observed acceptance probabilities were found to lie within a 95% confidence band. The parameters of compound gamma were used to calculate the fraction of aflatoxin-contaminated kernels in contaminated lots. At 20 ppb, it was estimated that about 6 in 10,000 kernels are contaminated.


Asunto(s)
Aflatoxinas/análisis , Zea mays/química , Algoritmos , Interpretación Estadística de Datos , Modelos Teóricos , Proyectos de Investigación , Medición de Riesgo , Muestreo
16.
J AOAC Int ; 83(5): 1279-84, 2000.
Artículo en Inglés | MEDLINE | ID: mdl-11048873

RESUMEN

The effects of changes in sample size and/or sample acceptance level on the performance of aflatoxin sampling plans for shelled corn were investigated. Six sampling plans were evaluated for a range of sample sizes and sample acceptance levels. For a given sample size, decreasing the sample acceptance level decreases the percentage of lots accepted while increasing the percentage of lots rejected at all aflatoxin concentrations, and decreases the average aflatoxin concentration in lots accepted and lots rejected. For a given sample size where the sample acceptance level decreases relative to a fixed regulatory guideline, the number of false positives increases and the number of false negatives decreases. For a given sample size where the sample acceptance level increases relative to a fixed regulatory guideline, the number of false positives decreases and the number of false negatives increases. For a given sample acceptance level, increasing the sample size increases the percentage of lots accepted at concentrations below the regulatory guideline while increasing the percentage of lots rejected at concentrations above the regulatory guideline, and decreases the average aflatoxin concentration in the lots accepted while increasing the average aflatoxin concentration in the rejected lots. For a given sample acceptance level that equals the regulatory guideline, increasing the sample size decreases misclassification of lots, both false positives and false negatives.


Asunto(s)
Aflatoxinas/análisis , Zea mays/química , Algoritmos , Interpretación Estadística de Datos , Modelos Teóricos , Proyectos de Investigación , Medición de Riesgo , Tamaño de la Muestra , Muestreo
17.
J AOAC Int ; 83(5): 1264-9, 2000.
Artículo en Inglés | MEDLINE | ID: mdl-11048871

RESUMEN

The variability associated with testing lots of shelled corn for aflatoxin was investigated. Eighteen lots of shelled corn were tested for aflatoxin contamination. The total variance associated with testing shelled corn was estimated and partitioned into sampling, sample preparation, and analytical variances. All variances increased as aflatoxin concentration increased. With the use of regression analysis, mathematical expressions were developed to model the relationship between aflatoxin concentration and the total, sampling, sample preparation, and analytical variances. The expressions for these relationships were used to estimate the variance for any sample size, subsample size, and number of analyses for a specific aflatoxin concentration. Test results on a lot with 20 parts per billion aflatoxin using a 1.13 kg sample, a Romer mill, 50 g subsamples, and liquid chromatographic analysis showed that the total, sampling, sample preparation, and analytical variances were 274.9 (CV = 82.9%), 214.0 (CV = 73.1 %), 56.3 (CV = 37.5%), and 4.6 (CV = 10.7%), respectively. The percentage of the total variance for sampling, sample preparation, and analytical was 77.8, 20.5, and 1.7, respectively.


Asunto(s)
Aflatoxinas/análisis , Zea mays/química , Algoritmos , Recolección de Datos , Proyectos de Investigación , Muestreo
18.
J AOAC Int ; 83(5): 1285-92, 2000.
Artículo en Inglés | MEDLINE | ID: mdl-11048874

RESUMEN

The variability associated with testing wheat for deoxynivalenol (DON) was measured using a 0.454 kg sample, Romer mill, 25 g comminuted subsample, and the Romer Fluoroquant analytical method. The total variability was partitioned into sampling, sample preparation, and analytical variability components. Each variance component was a function of the DON concentration and equations were developed to predict each variance component using regression techniques. The effect of sample size, subsample size, and number of aliquots on reducing the variability of the DON test procedure was also determined. For the test procedure, the coefficient of variation (CV) associated with testing wheat at 5 ppm was 13.4%. The CVs associated with sampling, sample preparation, and analysis were 6.3, 10.0, and 6.3%, respectively. For the sample variation, a 0.454 kg sample was used; for the sample preparation variation, a Romer mill and a 25 g subsample were used; for the analytical variation, the Romer Fluoroquant method was used. The CVs associated with testing wheat are relatively small compared to the CV associated with testing other commodities for other mycotoxins, such as aflatoxin in peanuts. Even when the small sample size of 0.454 kg was used, the sampling variation was not the largest source of error as found in other mycotoxin test procedures.


Asunto(s)
Tricotecenos/análisis , Triticum/química , Algoritmos , Interpretación Estadística de Datos , Proyectos de Investigación , Muestreo
19.
Biochem Biophys Res Commun ; 274(1): 32-6, 2000 Jul 21.
Artículo en Inglés | MEDLINE | ID: mdl-10903891

RESUMEN

Human glutathione transferase M2-2 prevents the formation of neurotoxic aminochrome and dopachrome by catalyzing the conjugation of dopamine and dopa o-quinone with glutathione. NMR analysis of dopamine and dopa o-quinone-glutathione conjugates revealed that the addition of glutathione was at C-5 to form 5-S-glutathionyl-dopamine and 5-S-glutathionyl-dopa, respectively. Both conjugates were found to be resistant to oxidation by biological oxidizing agents such as O(2), H(2)O(2), and O(*-)(2), and the glutathione transferase-catalyzed reaction can therefore serve a neuroprotective antioxidant function.


Asunto(s)
Benzoquinonas/metabolismo , Dihidroxifenilalanina/análogos & derivados , Dopamina/metabolismo , Glutatión Transferasa/metabolismo , Indolquinonas , Benzoquinonas/química , Cisteinildopa/análogos & derivados , Cisteinildopa/metabolismo , Dihidroxifenilalanina/química , Dihidroxifenilalanina/metabolismo , Dopamina/química , Glutatión/metabolismo , Glutatión Transferasa/química , Humanos , Indoles/metabolismo , Isoenzimas , Espectroscopía de Resonancia Magnética , Modelos Químicos , Oxidación-Reducción , Unión Proteica , Quinonas/metabolismo , Factores de Tiempo
20.
Mol Pharmacol ; 57(3): 619-24, 2000 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-10692504

RESUMEN

gamma-L-Glutamyl-S-(benzyl)-L-cysteinyl-R-(-)-phenylglycine (TER 117) has previously been developed for selective inhibition of human glutathione S-transferase P1-1 (GST P1-1) based on the postulated contribution of this isoenzyme to the development of drug resistance in cancer cells. In the present investigation, the inhibitory effect of TER 117 on the human glyoxalase system was studied. Although designed as an inhibitor specific for GST P1-1, TER 117 also competitively inhibits glyoxalase I (K(I) = 0.56 microM). In contrast, no inhibition of glyoxalase II was detected. Reduced glyoxalase activity is expected to raise intracellular levels of toxic 2-oxoaldehydes otherwise eliminated by glyoxalase I. The resulting toxicity would accompany the potentiation of cytostatic drugs, caused by inhibition of the detoxication effected by GST P1-1. TER 117 was designed for efficient inhibition of the most abundant form GST P1-1/Ile105. Therefore, the inhibitory effect of TER 117 on a second allelic variant GST P1-1/Val105 was also studied. TER 117 was shown to competitively inhibit both GST P1-1 variants. The apparent K(I) values at glutathione concentrations relevant to the intracellular milieu were in the micromolar range for both enzyme forms. Extrapolation to free enzyme produced K(I) values of approximately 0.1 microM for both isoenzymes, reflecting the high affinity of GST P1-1 for the inhibitor. Thus, the allelic variation in position 105 of GST P1-1 does not affect the inhibitory potency of TER 117. The inhibitory effects of TER 117 on GST P1-1 and glyoxalase I activities may act in synergy in the cell and improve the effectiveness of chemotherapy.


Asunto(s)
Inhibidores Enzimáticos/farmacología , Glutatión Transferasa/antagonistas & inhibidores , Isoenzimas/antagonistas & inhibidores , Lactoilglutatión Liasa/antagonistas & inhibidores , Oligopéptidos/farmacología , Resistencia a Antineoplásicos , Gutatión-S-Transferasa pi , Humanos , Oligopéptidos/química , Células Tumorales Cultivadas/efectos de los fármacos
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