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1.
Cancer Immunol Immunother ; 65(5): 563-73, 2016 May.
Artículo en Inglés | MEDLINE | ID: mdl-26980480

RESUMEN

In the dose-escalation phase of a Phase I clinical trial in which six subjects each were vaccinated with PepCan at the 50, 100, 250, and 500 µg per peptide dose, the 50 µg dose showed the best histological regression rate. Ten additional subjects were vaccinated at this dose in the final dose phase. As with the dose-escalation phase, no dose-limiting toxicities were observed. Overall, the histological regression rates were 50% at the 50 µg dose (7 of 14) and 100 µg dose (3 of 6), and 45 % overall (14 of 31). Of subjects in whom HPV type 16 (HPV 16) was detected at entry, it became undetectable in three subjects after vaccination, and the viral loads significantly decreased in nine subjects in whom HPV 16 infection was detected at entry and exit (p = 0.008). Immune profiling revealed increased T-helper type 1 cells after vaccinations (p = 0.02 and 0.0004 after 2 and 4 vaccinations, respectively). T-helper type 2 cells initially increased after two vaccinations (p = 0.01), but decreased below the baseline level after four vaccinations although not significantly. Pre-vaccination regulatory T cell levels were significantly lower in histological responders compared to non-responders (p = 0.03). Feasibility of testing plasma for multiplex cytokine/chemokine analysis and of performing proteomic analysis of PBMCs was examined for potentially identifying biomarkers in the future. While these analyses are feasible to perform, attention needs to be given to how soon the blood samples would be processed after phlebotomy. As sufficient safety of PepCan has been demonstrated, enrollment for the Phase II clinical trial has been opened.


Asunto(s)
Papillomavirus Humano 16/inmunología , Infecciones por Papillomavirus/inmunología , Neoplasias del Cuello Uterino/inmunología , Carga Viral/inmunología , Adulto , Cromatografía Liquida , Citocinas/sangre , Citocinas/inmunología , Relación Dosis-Respuesta a Droga , Femenino , Interacciones Huésped-Patógeno/efectos de los fármacos , Interacciones Huésped-Patógeno/inmunología , Papillomavirus Humano 16/efectos de los fármacos , Papillomavirus Humano 16/fisiología , Humanos , Leucocitos Mononucleares/efectos de los fármacos , Leucocitos Mononucleares/inmunología , Leucocitos Mononucleares/metabolismo , Persona de Mediana Edad , Infecciones por Papillomavirus/tratamiento farmacológico , Infecciones por Papillomavirus/virología , Proteoma/inmunología , Proteoma/metabolismo , Proteómica/métodos , Linfocitos T Reguladores/efectos de los fármacos , Linfocitos T Reguladores/inmunología , Espectrometría de Masas en Tándem , Neoplasias del Cuello Uterino/tratamiento farmacológico , Neoplasias del Cuello Uterino/virología , Vacunación/métodos , Vacunas de Subunidad/inmunología , Vacunas de Subunidad/uso terapéutico , Carga Viral/efectos de los fármacos , Adulto Joven
2.
Oncoimmunology ; 4(10): e1031439, 2015 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-26451301

RESUMEN

PURPOSE: Non-surgical treatments for cervical intraepithelial neoplasia 2/3 (CIN2/3) are needed as surgical treatments have been shown to double preterm delivery rate. The goal of this study was to demonstrate safety of a human papillomavirus (HPV) therapeutic vaccine called PepCan, which consists of four current good-manufacturing production-grade peptides covering the HPV type 16 E6 protein and Candida skin test reagent as a novel adjuvant. PATIENTS AND METHODS: The study was a single-arm, single-institution, dose-escalation phase I clinical trial, and the patients (n = 24) were women with biopsy-proven CIN2/3. Four injections were administered intradermally every 3 weeks in limbs. Loop electrical excision procedure (LEEP) was performed 12 weeks after the last injection for treatment and histological analysis. Six subjects each were enrolled (50, 100, 250, and 500 µg per peptide). RESULTS: The most common adverse events (AEs) were injection site reactions, and none of the patients experienced dose-limiting toxicities. The best histological response was seen at the 50 µg dose level with a regression rate of 83% (n = 6), and the overall rate was 52% (n = 23). Vaccine-induced immune responses to E6 were detected in 65% of recipients (significantly in 43%). Systemic T-helper type 1 (Th1) cells were significantly increased after four vaccinations (P = 0.02). CONCLUSION: This study demonstrated that PepCan is safe. A significantly increased systemic level of Th1 cells suggests that Candida, which induces interleukin-12 (IL-12) in vitro, may have a Th1 promoting effect. A phase II clinical trial to assess the full effect of this vaccine is warranted.

3.
Clin Trials ; 12(3): 199-204, 2015 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-25576067

RESUMEN

BACKGROUND: Historically, recruitment and retention of young women in intervention-based clinical trials have been challenging. In August 2012, enrollment for a clinical trial testing of an investigational human papillomavirus therapeutic vaccine called PepCan was opened at our institution. This study was an open-label, single-arm, single-institution, dose-escalation Phase I clinical trial. Women with recent Papanicolaou smear results showing high-grade squamous intraepithelial lesions or results that could not rule out high-grade squamous intraepithelial lesion were eligible to enroll. Patients with biopsy-confirmed high-grade squamous intraepithelial lesion were also eligible. Colposcopy was performed at the screening visit, and participants became eligible for vaccination when the diagnosis of high-grade squamous intraepithelial lesion was confirmed with biopsy and other inclusion criteria were met. The aim of this study was to identify strategies and factors effective in recruitment and retention of study participants. METHODS: Potential vaccine candidates were recruited through direct advertisement as well as referrals, including referrals through the Arkansas telecolposcopy network. The network is a federally funded program, administered by physicians and advanced practice nurses. The network telemedically links rural health sites and allows physician-guided colposcopy and biopsies to be conducted by advanced practice nurses. A variety of strategies were employed to assure good retention, including face-to-face contact with the study coordinator at the time of consent and most of study visits; frequent contact using text messaging, phone calls, and e-mails; and creation of a private Facebook page to improve communication among research staff and study participants. A questionnaire, inquiring about motivation for joining the study, occupation, education, household income, number of children, and number of sexual partners, was administered at the screening visit with the intent of identifying factor(s) associated with recruitment and retention. RESULTS: A total of 37 participants were enrolled between September 2012 and March 2014. The largest proportion of participants (46%) was enrolled from the telecolposcopy network. Others were enrolled through outside institutions (43%), in-house referrals (8%), or direct advertisement (3%). Most participants were motivated to join the study to take care of their health issues. Only two participants joined the Facebook private page. Of the 24 participants who qualified for vaccination, only 1 terminated early due to an unanticipated move. CONCLUSION: The availability of a large number of potential participants from the telecolposcopy network increased recruitment to this clinical trial by 85% over other traditional means of recruitment. The telecolposcopy network is not only a means of providing a gynecological service to women who otherwise would forego care but also a novel and valuable resource in recruiting participants for a clinical trial.


Asunto(s)
Colposcopía/métodos , Vacunas contra Papillomavirus/administración & dosificación , Selección de Paciente , Lesiones Intraepiteliales Escamosas de Cuello Uterino/diagnóstico , Telemedicina/organización & administración , Adulto , Comunicación , Femenino , Humanos , Persona de Mediana Edad , Prueba de Papanicolaou , Proyectos de Investigación , Servicios de Salud Rural/organización & administración , Factores Socioeconómicos
4.
J Nutr ; 142(9): 1621-5, 2012 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-22833654

RESUMEN

This work describes a novel liquid chromatography tandem MS (LC-MS/MS) method for the determination of ratios of acylcarnitines arising from acyl-CoA substrates and products that reflect metabolic disturbances caused by marginal biotin deficiency. The urinary ratios reflecting reduced activities of biotin-dependent enzymes include the following: 1) the ratio of 3-hydroxyisovalerylcarnitine : 3-methylglutarylcarnitine (3HIAc : MGc) for methylcrotonyl-CoA carboxylase; 2) the ratio of propionylcarnitine:methylmalonylcarnitine (Pc : MMc) for propionyl-CoA carboxylase (PCC); and 3) the ratio of acetylcarnitine : malonylcarnitine (Ac : Mc) for acetyl-CoA carboxylase. To demonstrate the suitability of the LC-MS/MS method for biomonitoring, we measured the 3 ratios for 7 healthy adults at various time points (d 0, 14, and 28) during the induction of marginal biotin through the consumption of egg white. The mean change in the Pc : MMc ratio relative to d 0 was 5.3-fold by d 14 (P = 0.0049) and 8.5-fold by d 28 (P = 0.0042). The mean change in the 3HIAc : MGc ratio was 2.8-fold by d 14 (P = 0.0022) and 3.8-fold by d 28 (P = 0.0001). The mean change in the Ac : Mc ratio was 2.9-fold by d 14 (P = 0.03) and 4.7-fold by d 28 (P = 0.02). The results suggest that simultaneous assessment of ratios of multiple biotin-dependent pathways offers insight into the complex metabolic disturbances caused by marginal biotin deficiency. We hypothesize that one or a combination of the ratios might be more sensitive or robust with respect to other nutrient deficiencies or confounding metabolic processes.


Asunto(s)
Biotina/deficiencia , Carnitina/análogos & derivados , Cromatografía Liquida/métodos , Enfermedades Carenciales/orina , Espectrometría de Masas en Tándem/métodos , Acetil-CoA Carboxilasa/metabolismo , Biomarcadores/orina , Biotina/orina , Ligasas de Carbono-Carbono/metabolismo , Ligasas de Carbono-Nitrógeno/metabolismo , Carnitina/análisis , Carnitina/orina , Cromatografía Liquida/normas , Enfermedades Carenciales/diagnóstico , Glutaratos/análisis , Glutaratos/orina , Humanos , Metilmalonil-CoA Descarboxilasa/metabolismo , Reproducibilidad de los Resultados , Especificidad por Sustrato , Espectrometría de Masas en Tándem/normas
5.
J Nutr ; 142(1): 22-6, 2012 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-22157538

RESUMEN

To date, marginal, asymptomatic biotin deficiency has been successfully induced experimentally by the use of labor-intensive inpatient designs requiring rigorous dietary control. We sought to determine if marginal biotin deficiency could be induced in humans in a less expensive outpatient design incorporating a self-selected, mixed general diet. We sought to examine the efficacy of three outpatient study designs: two based on oral avidin dosing and one based on a diet high in undenatured egg white for a period of 28 d. In study design 1, participants (n = 4; 3 women) received avidin in capsules with a biotin binding capacity of 7 times the estimated dietary biotin intake of a typical self-selected diet. In study design 2, participants (n = 2; 2 women) received double the amount of avidin capsules (14 times the estimated dietary biotin intake). In study design 3, participants (n = 5; 3 women) consumed egg-white beverages containing avidin with a biotin binding capacity of 7 times the estimated dietary biotin intake. Established indices of biotin status [lymphocyte propionyl-CoA carboxylase activity; urinary excretion of 3-hydroxyisovaleric acid, 3-hydroxyisovaleryl carnitine (3HIA-carnitine), and biotin; and plasma concentration of 3HIA-carnitine] indicated that study designs 1 and 2 were not effective in inducing marginal biotin deficiency, but study design 3 was as effective as previous inpatient study designs that induced deficiency by egg-white beverage. Marginal biotin deficiency can be induced experimentally by using a cost-effective outpatient design by avidin delivery in egg-white beverages. This design should be useful to the broader nutritional research community.


Asunto(s)
Biotina/deficiencia , Análisis Costo-Beneficio , Pacientes Ambulatorios , Animales , Enfermedades Carenciales/etiología , Enfermedades Carenciales/orina , Femenino , Humanos , Masculino , Ratones
6.
Anal Bioanal Chem ; 401(9): 2805-10, 2011 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-21892638

RESUMEN

Measurement of 3-hydroxyisovaleric acid (3HIA) in human urine has been shown to be a useful indicator of biotin status for a variety of clinical situations, including pregnancy. The work described herein presents a novel UPLC-MS/MS method for accurate and precise quantitation of urinary 3HIA. This method utilizes sample preparation prior to quantitation that has been simplified compared to the previous GC-MS method. To demonstrate the suitability of the UPLC-MS/MS method for human bio-monitoring, this method was used to measure 3-HIA in 64 human urine samples from eight healthy adults in whom marginal biotin deficiency had been induced experimentally by egg white feeding. 3HIA was detected in all specimens; the mean concentration [±standard deviation (SD)] was 80.6 ± 51 µM prior to inducing biotin deficiency. Mean excretion rate for 3HIA (expressed per mol urinary creatinine) before beginning the biotin-deficient diet was 8.5 ± 3.2 mmol 3HIA per mol creatinine and the mean increased threefold with deficiency. These specimens had been previously analyzed by GC-MS; the two data sets showed strong linear relationship with a correlation coefficient of 0.97. These results provide evidence that this method is suitable for bio-monitoring of biotin status in larger populations.


Asunto(s)
Biomarcadores/orina , Biotina/orina , Deficiencia de Biotinidasa/orina , Cromatografía Liquida/métodos , Clara de Huevo/efectos adversos , Espectrometría de Masas en Tándem/métodos , Valeratos/orina , Adulto , Biotina/deficiencia , Deficiencia de Biotinidasa/inducido químicamente , Calibración , Creatinina/orina , Femenino , Humanos , Masculino , Estándares de Referencia , Reproducibilidad de los Resultados , Sensibilidad y Especificidad
7.
J Nutr ; 141(11): 1925-30, 2011 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-21918059

RESUMEN

Experimentally increasing metabolic flux in a pathway in which an essential step is catalyzed by a vitamin-dependent enzyme (a challenge test) has been used in assessing functional vitamin status and elucidating common and alternate metabolic pathways. Conversion of 3-methylcrotonyl CoA to 3-methylglutaconyl CoA in the leucine catabolic pathway is catalyzed by the biotin-dependent enzyme methylcrotonyl-CoA carboxylase (MCC). Marginal biotin deficiency reduces MCC activity and increases urinary excretion of 3-hydroxyisovaleric acid (3HIA) and 3-hydroxyisovaleryl carnitine (3HIA-carnitine) measured in 24-h urine collections. We assessed urinary excretion of 3HIA and 3HIA-carnitine in response to a leucine challenge in humans made progressively biotin deficient by egg white consumption. In 2 cohorts of healthy adults (Study 1: n = 5; Study 2: n = 7) rendered biotin deficient over 28 d, urinary excretion of 3HIA and 3HIA-carnitine in response to a leucine challenge was quantitated weekly for 3 or 4 wk, respectively. In both studies, mean urinary excretion of both 3HIA and 3HIA-carnitine increased >2-fold by d 14 (P < 0.002 for both indicators for both studies). Diagnostically, both indicators were highly sensitive, but diagnostic sensitivities were not superior to those of 24-h excretion of 3HIA and 3HIA-carnitine. These studies provide evidence that urinary excretions of 3HIA and 3HIA-carnitine in response to an oral leucine challenge are early and sensitive indicators of marginal biotin deficiency in humans. The variability of the proportion of leucine catabolites excreted as 3HIA suggests substantial population heterogeneity in the metabolic capacity of the 3HIA-carnitine detoxification pathway.


Asunto(s)
Biotina/deficiencia , Carnitina/análogos & derivados , Leucina/administración & dosificación , Valeratos/orina , Adulto , Carnitina/orina , Estudios de Cohortes , Femenino , Humanos , Masculino
8.
J Nutr ; 141(3): 353-8, 2011 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-21248194

RESUMEN

Mounting evidence indicates that marginal biotin deficiency is not rare, contrary to previous assumptions. Accordingly, robust indicators of biotin status would be useful. In a study of 10 healthy adults, we recently provided evidence that abnormally increased plasma concentration of 3-hydroxyisovaleryl carnitine (3HIA-carnitine) is a sensitive indicator of marginal biotin deficiency. We sought to determine whether urinary excretion of 3HIA-carnitine (expressed as the ratio to urinary creatinine) significantly increases in marginal biotin deficiency. Marginal, asymptomatic biotin deficiency was induced experimentally in the same 10 healthy adults (8 women) by feeding undenatured egg white with meals for 28 d. Biotin status was repleted by a mixed general diet plus biotin supplementation. Urinary excretion of 3HIA-carnitine was determined by liquid chromatography-tandem MS on d 0, 14, and 28 (depletion) and on d 35 and 50 (repletion). Mean urinary 3HIA-carnitine concentration increased with depletion (P < 0.0001; d 0 vs. 28) and decreased with repletion (P = 0.0002; d 28 vs. 50). Urinary 3HIA-carnitine excretion was greater than the upper limit of normal in 9 of 10 participants by d 14 and decreased to within normal limits by d 50 in all participants. This study provides evidence that urinary excretion of 3HIA-carnitine is an early and sensitive indicator of marginal biotin deficiency. The ease of collection of untimed urine samples and application of a new analytical method with simplified sample preparation suggest that urinary 3HIA-carnitine is likely to be a useful indicator for large population studies.


Asunto(s)
Biotina/deficiencia , Carnitina/análogos & derivados , Estado Nutricional , Deficiencia de Vitamina B/diagnóstico , Deficiencia de Vitamina B/orina , Adulto , Biomarcadores/sangre , Biomarcadores/orina , Biotina/uso terapéutico , Carnitina/orina , Clara de Huevo , Femenino , Humanos , Linfocitos/enzimología , Masculino , Metilmalonil-CoA Descarboxilasa/sangre , Valores de Referencia , Factores de Tiempo , Deficiencia de Vitamina B/sangre , Deficiencia de Vitamina B/tratamiento farmacológico
9.
Anal Chem ; 82(22): 9543-8, 2010 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-21028833

RESUMEN

Abnormally increased urinary excretion of 3-hydroxyisovaleryl carnitine (3HIA-carnitine) results from impairment in leucine catabolism caused by reduced activity of the biotin-dependent enzyme 3-methylcrotonyl-CoA carboxylase. Accordingly, urinary 3HIA-carnitine might reflect biotin status. Here, we describe an LC-MS/MS method for accurately quantitating the urinary concentration of 3HIA-carnitine at concentrations that are typical for excretion rates that are normal or only modestly increased. This method allows for high sample throughput and does not require solid-phase extraction. We used this method to provide evidence validating urinary 3HIA-carnitine as a biomarker of biotin deficiency in humans. Four healthy adult subjects were successfully made marginally biotin deficient by feeding a 30% egg white diet for 28 days. From study day 0 to 28, the mean urinary excretion of 3HIA-carnitine increased 3.5-fold (p = 0.026). These preliminary results indicate that urinary excretion of 3HIA-carnitine increases with marginal biotin deficiency. If these results are confirmed in studies involving larger numbers of subjects, urinary excretion of 3HIA-carnitine may potentially be a clinically useful indicator of biotin status.


Asunto(s)
Biotina/metabolismo , Carnitina/análogos & derivados , Cromatografía Liquida/métodos , Espectrometría de Masas en Tándem/métodos , Urinálisis/métodos , Adulto , Biomarcadores/orina , Biotina/deficiencia , Carnitina/orina , Femenino , Humanos , Masculino , Reproducibilidad de los Resultados , Factores de Tiempo
10.
Am J Clin Nutr ; 92(6): 1399-405, 2010 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-20943794

RESUMEN

BACKGROUND: Blood-based indicators of biotin status in humans were shown to be useful tools in several clinical situations, including pregnancy. We previously validated the activity of the biotin-dependent enzyme propionyl-coenzyme A carboxylase (PCC) in lymphocytes as a sensitive and specific blood-based indicator of marginal degrees of biotin deficiency. However, the measurement of PCC activity in population studies presents substantial analytic challenges. 3-Hydroxyisovaleryl carnitine (3HIA-carnitine) increases in response to the decreased activity of the biotin-dependent enzyme methylcrotonyl-coenzyme A carboxylase and might reflect biotin status. OBJECTIVE: We sought to determine whether the plasma concentration of 3HIA-carnitine increases significantly in marginal biotin deficiency. DESIGN: We experimentally induced marginal, asymptomatic biotin deficiency in 10 healthy adults (8 women) by having the subjects consume undenatured egg white for 28 d; biotin status was then repleted. Plasma concentrations of 3HIA-carnitine were measured on days 0, 14, 28, 35, and 50 by liquid chromatography-mass spectroscopy. RESULTS: The mean plasma 3HIA-carnitine concentration increased with depletion (P < 0.0001) and decreased with repletion (P < 0.0001). Plasma 3HIA-carnitine concentrations were greater than the upper limit of normal concentrations in 7 of 10 subjects by day 14 and in 9 of 10 subjects by day 28 and decreased to within normal limits in 9 of 10 subjects by day 50. CONCLUSIONS: These studies provide evidence that 3HIA-carnitine is an early and sensitive indicator of marginal biotin deficiency. The ease of sample collection, small sample volume requirement, and stability of 3HIA-carnitine during storage suggest that plasma 3HIA-carnitine concentration is likely to be a useful indicator of marginal biotin deficiency for larger population studies.


Asunto(s)
Biotina/deficiencia , Carnitina/sangre , Adulto , Anciano , Biomarcadores/sangre , Biotina/sangre , Ligasas de Carbono-Carbono/metabolismo , Carnitina/análogos & derivados , Enfermedades Carenciales/diagnóstico , Clara de Huevo , Femenino , Humanos , Masculino , Persona de Mediana Edad
11.
Anal Chem ; 82(10): 4140-4, 2010 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-20397702

RESUMEN

An increased plasma concentration of 3-hydroxyisovaleryl carnitine (3HIA-carnitine) results from impairment in the leucine catabolic pathway at the conversion of 3-methylcrotonyl-CoA to 3-methylglutaconyl-CoA. The impairment is caused by reduced activity of the biotin-dependent enzyme 3-methylcrotonyl-CoA carboxylase. Here, we describe an LC-MS/MS method for the quantitation of 3HIA-carnitine in plasma and present preliminary evidence validating plasma 3HIA-carnitine as a novel biomarker of biotin deficiency in humans. Three healthy adult subjects were successfully made marginally biotin deficient by feeding of a 30% egg-white diet for 28 days. For each subject, the plasma 3HIA-carnitine increased approximately 3-fold from Study Day 0 to Study Day 28 (p = 0.027). These results indicate that plasma 3HIA-carnitine concentration increases with biotin deficiency. If these results are confirmed in larger studies, plasma 3HIA-carnitine is likely to be an important indicator of biotin status in a variety of clinical circumstances because quantitation of 3HIA-carnitine by this method has several technical advantages over existing validated indicators of biotin status in humans.


Asunto(s)
Biomarcadores/sangre , Biotina/química , Carnitina/análogos & derivados , Cromatografía Liquida/métodos , Espectrometría de Masas/métodos , Complejo Vitamínico B/sangre , Adulto , Análisis Químico de la Sangre , Carnitina/sangre , Carnitina/química , Humanos
12.
Am J Clin Nutr ; 88(5): 1291-6, 2008 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-18996865

RESUMEN

BACKGROUND: Biotin is likely transported into cerebral spinal fluid (CSF) via one or more specific transporters. Concentrations of biotin in CSF measured by using modern analytic techniques that are specific for biotin and biotin metabolites have not previously been reported. OBJECTIVES: We aimed to accurately measure the concentration of biotin and major biotin metabolites, biotin sulfoxide (BSO) and bisnorbiotin (BNB), in the CSF of children. DESIGN: Concentrations of biotin were determined initially as total avidin-binding substances (TABS) in CSF obtained by lumbar puncture from 55 children. Biotin, BSO, and BNB were quantitated by HPLC and an avidin-binding assay in CSF samples from a subset of 11 children. RESULTS: Concentrations of TABS in CSF averaged 1.6 nmol/L with substantial variability (SD = 1.3 nmol/L). CSF concentrations of biotin and biotin analogs varied widely, but substantial amounts of BSO were detected in every sample. Biotin accounted for 42 +/- 16%, BSO for 41 +/- 12%, and BNB for 8 +/- 14% of the total. It was surprising that the molar sum of biotin, BSO, and BNB on average was >200-fold the TABS concentrations from the same CSF sample. Using several analytic approaches, we found no masking of detection, nor did we find degradation of biotin or BSO. Gel electrophoresis and streptavidin Western blot detected several biotinylated proteins in CSF. CONCLUSIONS: Biotin appears to be bound to protein covalently, reversibly, or both, and this binding likely accounts for the increase in detectable biotin after HPLC. Protein-bound biotin may play an important role in biotin nutriture of the brain.


Asunto(s)
Avidina/metabolismo , Biotina/análisis , Biotina/líquido cefalorraquídeo , Líquido Cefalorraquídeo/química , Adolescente , Unión Competitiva , Biotina/análogos & derivados , Biotina/metabolismo , Niño , Preescolar , Cromatografía Líquida de Alta Presión/métodos , Femenino , Humanos , Lactante , Masculino
13.
Am J Clin Nutr ; 84(2): 384-8, 2006 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-16895887

RESUMEN

BACKGROUND: Marginal biotin deficiency may be a human teratogen. A biotin status indicator that is not dependent on renal function may be useful in studies of biotin status during pregnancy. A previous study of experimental biotin deficiency suggested that propionyl-coenzyme A carboxylase (PCC) activity in peripheral blood lymphocytes (PBLs) is a sensitive indicator of biotin status. OBJECTIVE: We examined the utility of measuring PCC activity and the activation of PCC by biotin in detecting marginal biotin deficiency. DESIGN: Marginal biotin deficiency was induced in 7 adults (3 women) by egg-white feeding for 28 d. Blood and urine were obtained on days 0, 14, and 28 (depletion phase) and 44 and 65 (repletion phase). PBLs were incubated with (activated) or without (control) biotin before PCC assay. The activation coefficient of PCC is the ratio of PCC activity in activated PBLs to that in control PBLs. The significance of differences for all measurements was tested by repeated-measures analysis of variance with Fisher's post hoc test and Bonferroni correction. RESULTS: Changes in the urinary excretion of biotin and of 3-hydroxyisovaleric acid confirmed that marginal biotin deficiency was successfully induced. By day 14, PCC activity had decreased (P < 0.0001) to below the lower limit of normal in all subjects. By day 28, the activation coefficient of PCC had increased significantly (P = 0.003) and was above the upper limit of normal in 6 of 7 subjects. CONCLUSION: PCC activity is the most sensitive indicator of biotin status tested to date. In future pregnancy studies, the use of lymphocyte PCC activity data should prove valuable in the assessment of biotin status.


Asunto(s)
Biotina/deficiencia , Linfocitos/enzimología , Metilmalonil-CoA Descarboxilasa/metabolismo , Evaluación Nutricional , Estado Nutricional , Adulto , Análisis de Varianza , Biomarcadores/sangre , Biotina/sangre , Biotina/orina , Estudios Cruzados , Enfermedades Carenciales/sangre , Enfermedades Carenciales/diagnóstico , Enfermedades Carenciales/orina , Femenino , Humanos , Masculino , Metilmalonil-CoA Descarboxilasa/sangre , Sensibilidad y Especificidad , Valeratos/orina
14.
J Nutr ; 135(5): 973-7, 2005 May.
Artículo en Inglés | MEDLINE | ID: mdl-15867267

RESUMEN

Marginal maternal biotin deficiency reduces hepatic activity of biotin-dependent carboxylases and causes high rates of fetal birth defects in mice. We tested the hypothesis that the decreased carboxylase activity observed in deficient dams and their offspring is mediated by decreased abundance of biotinylated carboxylases, decreased expression of their mRNAs, or both. During gestation, CD-1 mice were fed a diet that induced biotin deficiency or a biotin-sufficient diet. On gestational d 17, gravid uteri were removed, and each live fetus was examined grossly for defects. The expected high incidence of cleft palate (83%) in offspring was observed. In maternal and fetal liver, acetyl-CoA carboxylase, pyruvate carboxylase, propionyl-CoA carboxylase, and beta-methylcrotonyl-CoA carboxylase abundances were determined by Western blotting; the content of mRNAs for most of these enzymes and holocarboxylase synthetase was determined by real-time RT-PCR. Biotin deficiency significantly reduced the abundance of the carboxylases in maternal and fetal liver; neither the content of mRNAs for the carboxylases nor holocarboxylase synthetase changed. This study provides evidence that the decrease in carboxylase activities is attributable to a decrease in the abundance of biotinylated carboxylases; further, this effect is more severe in fetuses than dams.


Asunto(s)
Biotina/deficiencia , Ligasas de Carbono-Nitrógeno/genética , Desarrollo Fetal , Regulación del Desarrollo de la Expresión Génica , Efectos Tardíos de la Exposición Prenatal , Animales , Secuencia de Bases , Cartilla de ADN , Femenino , Regulación Enzimológica de la Expresión Génica , Edad Gestacional , Ratones , Embarazo , ARN Mensajero/genética , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa
15.
J Nutr ; 135(1): 42-7, 2005 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-15623830

RESUMEN

In evaluating potential indicators of biotin status, we quantitated the expression of biotin-related genes in leukocytes from human blood of normal subjects before and after inducing marginal biotin deficiency. Biotin deficiency was induced experimentally by feeding an egg-white diet for 28 d. Gene expression was quantitated for the following biotin-related proteins: methylcrotonyl-CoA carboxylase chains A (MCCA) and B (MCCB); propionyl-CoA carboxylase chains A (PCCA) and B (PCCB); pyruvate carboxylase (PC); acetyl-CoA carboxylase isoforms A (ACCA) and B (ACCB); holocarboxylase synthetase (HCS); biotinidase; and 2 potential biotin transporters: sodium-dependent multivitamin transporter (SMVT) and solute carrier family 19 member 3 (SLC19A3). For 7 subjects who successfully completed the study, the abundance of the specific mRNAs was determined by quantitative real-time RT-PCR at d 0 and 28. At d 28, SLC19A3 expression had decreased to 33% of d 0 (P < 0.02 by two-tailed, paired t test). Expression of MCCA, PCCA, PC, ACCA, ACCB, HCS, biotinidase, and SMVT decreased to approximately 80% of d 0 (P < 0.05). Expression of the MCCB and PCCB chains that do not carry the biotin-binding motif did not change significantly; we speculate that expression of the biotin-binding chains of biotin-dependent carboxylases is more responsive to biotin status changes. These data provide evidence that expression of SLC19A3 is a relatively sensitive indicator of marginal biotin deficiency.


Asunto(s)
Biotina/deficiencia , Regulación Enzimológica de la Expresión Génica/fisiología , Leucocitos/fisiología , Proteínas de Transporte de Membrana/genética , Adulto , Secuencia de Bases , Cartilla de ADN , Femenino , Regulación Enzimológica de la Expresión Génica/efectos de los fármacos , Humanos , Leucocitos/efectos de los fármacos , Masculino , Proteínas de Transporte de Membrana/sangre , Reacción en Cadena de la Polimerasa
16.
Am J Clin Nutr ; 80(4): 932-5, 2004 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-15447901

RESUMEN

BACKGROUND: Smoking accelerates the degradation of many nutrients, including lipids, antioxidants, and certain B vitamins. Accelerated biotin catabolism is of concern in women because marginal biotin deficiency is teratogenic in mammals. OBJECTIVE: The objective was to assess the effect of smoking on the biotin status of women. DESIGN: A preliminary study of 7 women and 3 men examined the urinary concentrations of biotin and its metabolites biotin sulfoxide and bisnorbiotin in smokers. The interpretation of the results of this study was limited by the lack of a contemporaneous control group; consequently, we conducted a cohort-controlled study. Smoking women (n = 8) and nonsmoking control subjects (n = 15) provided 24-h urine samples; excretion rates of biotin, the biotin metabolites, and 3-hydroxyisovaleric acid were determined. Increased urinary excretion of 3-hydroxyisovaleric acid, which reflects a reduced activity of the biotin-dependent enzyme 3-methylcrotonyl-Co A carboxylase, is a sensitive indicator of biotin depletion at the tissue level. RESULTS: Compared with control subjects from previous studies, the smoking women in the preliminary study excreted significantly less urinary biotin (P = 0.02). Moreover, the ratio of urinary biotin sulfoxide to biotin increased (P = 0.04) in these women. In the cohort-controlled study, the urinary excretion of biotin decreased by 30% (P = 0.04), and the ratios of urinary bisnorbiotin and biotin sulfoxide to biotin increased significantly, which indicated accelerated catabolism in smokers. Moreover, the urinary excretion of 3-hydroxyisovaleric acid was greater in the smokers than in the control subjects (P = 0.04), which indicated biotin depletion in the smokers at the tissue level. CONCLUSION: These data provide evidence of accelerated biotin metabolism in smoking women, which results in marginal biotin deficiency.


Asunto(s)
Biotina/análogos & derivados , Biotina/deficiencia , Biotina/metabolismo , Fumar/efectos adversos , Adulto , Avidina/metabolismo , Biomarcadores/sangre , Biomarcadores/orina , Biotina/orina , Ligasas de Carbono-Carbono/metabolismo , Estudios de Casos y Controles , Cromatografía Líquida de Alta Presión , Estudios de Cohortes , Creatinina/orina , Femenino , Humanos , Masculino , Persona de Mediana Edad , Factores Sexuales , Valeratos/orina
17.
Blood ; 101(7): 2542-6, 2003 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-12468437

RESUMEN

The incidence of mold infections in patients with hematologic malignancies continues to increase despite the widespread use of air filtration systems, suggesting the presence of other hospital sources for these molds. Water sources are known to harbor pathogenic molds. We examined samples from water, water surfaces, air, and other environment sources from a bone marrow transplantation unit with optimal air precautions. Molds (Aspergillus species, others) were recovered in 70% of 398 water samples, in 22% of 1311 swabs from plumbing structures and environmental surfaces, and in 83% of 274 indoor air samples. Microscopic examination of the water plumbing lines revealed hyphal forms compatible with molds. Four findings suggest that indoor airborne molds were aerosolized from the water: (1) higher mean airborne concentrations of molds in bathrooms (16.1 colony-forming units [CFU]/m(3)) than in patient rooms (7 CFU/m(3)) and hallways (8.6 CFU/m(3); P =.00005); (2) a strong type and rank correlation between molds isolated from hospital water and those recovered from indoor hospital; (3) lack of seasonal correlation between the airborne mold concentration in outdoor and indoor air; and (4) molecular relatedness between a clinical strain and a water-related strain (previously reported). Hospital water distribution systems may serve as a potential indoor reservoir of Aspergillus and other molds leading to aerosolization of fungal spores and potential exposure for patients.


Asunto(s)
Hongos/aislamiento & purificación , Neoplasias Hematológicas/complicaciones , Hospitales/normas , Micosis/transmisión , Microbiología del Agua , Microbiología del Aire , Aspergillus/aislamiento & purificación , Aspergillus/patogenicidad , Trasplante de Médula Ósea/efectos adversos , Cloro/análisis , Hongos/patogenicidad , Humanos , Huésped Inmunocomprometido , Micosis/etiología , Infecciones Oportunistas/transmisión , Abastecimiento de Agua/normas
18.
Clin Infect Dis ; 35(8): E86-8, 2002 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-12355397

RESUMEN

We previously have demonstrated that the hospital water-distribution system could be a reservoir for airborne molds that leads to secondary aerosolization of these molds in patient shower facilities. In this report, we show that cleaning the floors of patient shower facilities in a bone marrow transplantation unit reduced the mean air concentrations of molds, including Aspergillus species (from 12 cfu/m3 to 4 cfu/m3; P=.0047).


Asunto(s)
Aspergilosis/prevención & control , Aspergillus , Infecciones Oportunistas/prevención & control , Saneamiento , Aspergilosis/microbiología , Desinfección , Humanos , Infecciones Oportunistas/microbiología , Microbiología del Agua , Abastecimiento de Agua
19.
Clin Infect Dis ; 34(6): 780-9, 2002 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-11850861

RESUMEN

Nosocomial aspergillosis, a life-threatening infection in immunocompromised patients, is thought to be caused primarily by Aspergillus organisms in the air. A 3-year prospective study of the air, environmental surfaces, and water distribution system of a hospital in which there were known cases of aspergillosis was conducted to determine other possible sources of infection. Aspergillus species were found in the hospital water system. Significantly higher concentrations of airborne aspergillus propagules were found in bathrooms, where water use was highest (2.95 colony-forming units [cfu]/m(3)) than in patient rooms (0.78 cfu/m(3); P=.05) and in hallways (0.61 cfu/m(3); P=.03). A correlation was found between the rank orders of Aspergillus species recovered from hospital water and air. Water from tanks yielded higher counts of colony-forming units than did municipal water. An isolate of Aspergillus fumigatus recovered from a patient with aspergillosis was genotypically identical to an isolate recovered from the shower wall in the patient's room. In addition to the air, hospital water systems may be a source of nosocomial aspergillosis.


Asunto(s)
Aspergillus/aislamiento & purificación , Microbiología del Agua , Contaminación del Agua , Contaminación del Aire , Aspergilosis/epidemiología , Aspergilosis/microbiología , Infección Hospitalaria/epidemiología , Hospitales , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos
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