RESUMEN
Background: Neoadjuvant anti-PD-1 may improve outcomes for patients with resectable NSCLC and provides a critical window for examining pathologic features associated with response. Resections showing major pathologic response to neoadjuvant therapy, defined as ≤10% residual viable tumor (RVT), may predict improved long-term patient outcome. However, %RVT calculations were developed in the context of chemotherapy (%cRVT). An immune-related %RVT (%irRVT) has yet to be developed. Patients and methods: The first trial of neoadjuvant anti-PD-1 (nivolumab, NCT02259621) was just reported. We analyzed hematoxylin and eosin-stained slides from the post-treatment resection specimens of the 20 patients with non-small-cell lung carcinoma who underwent definitive surgery. Pretreatment tumor biopsies and preresection radiographic 'tumor' measurements were also assessed. Results: We found that the regression bed (the area of immune-mediated tumor clearance) accounts for the previously noted discrepancy between CT imaging and pathologic assessment of residual tumor. The regression bed is characterized by (i) immune activation-dense tumor infiltrating lymphocytes with macrophages and tertiary lymphoid structures; (ii) massive tumor cell death-cholesterol clefts; and (iii) tissue repair-neovascularization and proliferative fibrosis (each feature enriched in major pathologic responders versus nonresponders, P < 0.05). This distinct constellation of histologic findings was not identified in any pretreatment specimens. Histopathologic features of the regression bed were used to develop 'Immune-Related Pathologic Response Criteria' (irPRC), and these criteria were shown to be reproducible amongst pathologists. Specifically, %irRVT had improved interobserver consistency compared with %cRVT [median per-case %RVT variability 5% (0%-29%) versus 10% (0%-58%), P = 0.007] and a twofold decrease in median standard deviation across pathologists within a sample (4.6 versus 2.2, P = 0.002). Conclusions: irPRC may be used to standardize pathologic assessment of immunotherapeutic efficacy. Long-term follow-up is needed to determine irPRC reliability as a surrogate for recurrence-free and overall survival.
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Antineoplásicos Inmunológicos/uso terapéutico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Carcinoma de Pulmón de Células no Pequeñas/terapia , Neoplasias Pulmonares/terapia , Pulmón/patología , Adulto , Antineoplásicos Inmunológicos/farmacología , Protocolos de Quimioterapia Combinada Antineoplásica/farmacología , Carcinoma de Pulmón de Células no Pequeñas/inmunología , Carcinoma de Pulmón de Células no Pequeñas/patología , Estudios de Factibilidad , Humanos , Ipilimumab/farmacología , Ipilimumab/uso terapéutico , Pulmón/inmunología , Pulmón/cirugía , Neoplasias Pulmonares/inmunología , Neoplasias Pulmonares/patología , Terapia Neoadyuvante/métodos , Neoplasia Residual , Nivolumab/farmacología , Nivolumab/uso terapéutico , Neumonectomía , Pronóstico , Receptor de Muerte Celular Programada 1/antagonistas & inhibidores , Receptor de Muerte Celular Programada 1/inmunología , Reproducibilidad de los Resultados , Resultado del TratamientoRESUMEN
AIMS: To determine whether alanine aminotransferase or gamma-glutamyltransferase levels, as markers of liver health and non-alcoholic fatty liver disease, might predict cardiovascular events in people with Type 2 diabetes. METHODS: Data from the Fenofibrate Intervention and Event Lowering in Diabetes study were analysed to examine the relationship between liver enzymes and incident cardiovascular events (non-fatal myocardial infarction, stroke, coronary and other cardiovascular death, coronary or carotid revascularization) over 5 years. RESULTS: Alanine aminotransferase measure had a linear inverse relationship with the first cardiovascular event occurring in participants during the study period. After adjustment, for every 1 sd higher baseline alanine aminotransferase measure (13.2 U/l), the risk of a cardiovascular event was 7% lower (95% CI 4-13; P = 0.02). Participants with alanine aminotransferase levels below and above the reference range 8-41 U/l for women and 9-59 U/l for men, had hazard ratios for a cardiovascular event of 1.86 (95% CI 1.12-3.09) and 0.65 (95% CI 0.49-0.87), respectively (P = 0.001). No relationship was found for gamma-glutamyltransferase. CONCLUSIONS: The data may indicate that in people with Type 2 diabetes, which is associated with higher alanine aminotransferase levels because of prevalent non-alcoholic fatty liver disease, a low alanine aminotransferase level is a marker of hepatic or systemic frailty rather than health.
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Alanina Transaminasa/sangre , Enfermedades Cardiovasculares/epidemiología , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Diabetes Mellitus Tipo 2/epidemiología , Fenofibrato/uso terapéutico , Adulto , Anciano , Biomarcadores/sangre , Enfermedades Cardiovasculares/sangre , Enfermedades Cardiovasculares/etiología , Diabetes Mellitus Tipo 2/complicaciones , Femenino , Humanos , Incidencia , Masculino , Persona de Mediana Edad , Factores de Riesgo , gamma-Glutamiltransferasa/sangreRESUMEN
A sample of lunar dust was examined for organic compounds. Carbon detected in concentrations of 157 micrograms per gram had a delta(13)C per mil (PDB) value of + 20. Treatment with hydrochloric acid yielded hydrocarbons of low molecular weight, suggesting the presence of carbides. The gas chromatogram of the acylated and esterified derivatives of the hydrolyzate was similar to that obtained for the Pueblito de Allende meteorite. There were no detectable amounts of extractable high-molecular-weight alkanes, aromatic hydrocarbons, isoprenoid hydrocarbons, normal alkanes, fatty acids, amino acids, sugars, or nucleic acid bases. Traces of porphyrins were found, perhaps arising from rocket exhaust materials.
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The FMS-like tyrosine kinase-3 (FLT3) gene is the most commonly mutated gene in acute myeloid leukemia (AML), and patients carrying internal tandem duplication (ITD) mutations have a poor prognosis. Long-term inhibition of FLT3 activity in these patients has been elusive. To provide a more complete understanding of FLT3 biology, a mass spectroscopy-based screen was performed to search for FLT3-interacting proteins. The screen identified dedicator of cytokinesis 2 (DOCK2), which is a guanine nucleotide exchange factor for Rho GTPases, and its expression is limited to hematolymphoid cells. We show that DOCK2 is expressed in leukemia cell lines and primary AML samples, and DOCK2 co-immunoprecipitates with wild-type FLT3 and FLT3/ITD. Knockdown (KD) of DOCK2 by shRNA selectively reduced cell proliferation and colony formation in leukemia cell lines with increased FLT3 activity, and greatly sensitized these cells to cytarabine treatment, alone and in combination with FLT3 tyrosine kinase inhibitors. DOCK2 KD in an FLT3/ITD-positive leukemia cell line also significantly prolonged survival in a mouse xenograft model. These findings suggest that DOCK2 is a potential therapeutic target for novel AML treatments, as this protein regulates the survival of leukemia cells with elevated FLT3 activity and sensitizes FLT3/ITD leukemic cells to conventional antileukemic agents.
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Expresión Génica , Factores de Intercambio de Guanina Nucleótido/metabolismo , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/metabolismo , Tirosina Quinasa 3 Similar a fms/genética , Tirosina Quinasa 3 Similar a fms/metabolismo , Animales , Antineoplásicos/farmacología , Células Sanguíneas/metabolismo , Línea Celular Tumoral , Proliferación Celular/genética , Supervivencia Celular/efectos de los fármacos , Supervivencia Celular/genética , Modelos Animales de Enfermedad , Activación Enzimática , Femenino , Proteínas Activadoras de GTPasa , Técnicas de Silenciamiento del Gen , Factores de Intercambio de Guanina Nucleótido/genética , Humanos , Ratones , Unión Proteica , ARN Interferente Pequeño/genética , Proteína de Unión al GTP rac1/metabolismoRESUMEN
BACKGROUND: Papillary carcinoma of the thyroid (PTC) is the most prevalent malignancy of the thyroid gland. Although the majority of lesions are sporadic tumors, an established relationship exists between familial adenomatous polyposis (FAP) and PTC. Moreover, some authors postulate the existence of familial PTC as a distinct entity. Evidence for this is limited, however, there being few well characterized descriptions of pedigrees with high prevalence of PTC. AIMS: The objective of the present study was to examine an apparent heritable predisposition to PTC occurring in two Tasmanian families in which PTC occurs commonly. METHODS: Pedigree charts were constructed for both families and the medical records of the members reviewed. RESULTS: In Pedigree I, 7 of 25 members had PTC (6 of these had coexisting multinodular goiter (MNG), and 11 others had MNG. In Pedigree II, identical male twins and their daughters had PTC. CONCLUSIONS: In both families there is evidence of autosomal dominant inheritance of PTC. The association of PTC with MNG suggests a possible role for MNG in tumor pathogenesis in hereditary PTC. The majority of the patients were diagnosed with PTC before commencement of prospective screening, indicating clinically relevant disease in the families described.
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Carcinoma Papilar/genética , Genes Dominantes , Neoplasias de la Tiroides/genética , Adulto , Enfermedades en Gemelos/genética , Femenino , Predisposición Genética a la Enfermedad , Humanos , Masculino , Persona de Mediana Edad , LinajeRESUMEN
BACKGROUND: Current US dietary recommendations for selenium are based on maximization of plasma glutathione peroxidase (GSHPx) activity according to data from one study of Chinese men. OBJECTIVE: The effect of various amounts of supplemental selenium on GSHPx activities in blood of New Zealand adults was investigated to calculate a selenium requirement for New Zealanders. The effect on plasma selenoprotein P and thyroid hormones was also investigated. DESIGN: Fifty-two adults with low blood selenium concentrations ingested a placebo or 10, 20, 30, or 40 microgram Se as L-selenomethionine daily for 20 wk. RESULTS: Plasma and whole-blood GSHPx activities increased in all supplemented groups but reached a plateau only in the group receiving 40 microgram Se, as determined by statistical analysis. Increases in selenoprotein P were greater than those for selenium and GSHPx at all supplement intakes. Thyroxine concentrations decreased in supplemented groups but the decrease was significantly different from that in the control group only for the 10-microgram group and for all supplemented groups combined. CONCLUSIONS: An upper estimated requirement of 90 microgram Se/d was calculated as the intake necessary for maximization of plasma GSHPx activity, as used in the derivation of the US recommended daily allowance. Our lower estimated requirement of 39 microgram Se/d was the intake necessary to reach two-thirds of maximal GSHPx activity, as was used in calculating the World Health Organization normative requirement. The lower estimate is a realistic goal for New Zealand but the upper estimate could be achieved only with regular inclusion of high-selenium foods.
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Glutatión Peroxidasa/sangre , Proteínas/metabolismo , Selenio/administración & dosificación , Selenio/sangre , Adulto , Método Doble Ciego , Femenino , Humanos , Masculino , Persona de Mediana Edad , Nueva Zelanda , Política Nutricional , Necesidades Nutricionales , Radioinmunoensayo , Selenoproteína P , Selenoproteínas , Tiroxina/sangreRESUMEN
The stereoselective accumulation of alpha-methyl-p-tyramine (AMPT) and alpha-methyl-p-octopamine (AMPO) in rat striatum and hypothalamus after acute and chronic administration of the (+)- and (-)-isomers of amphetamine (Amphet) and the acute administration of (+)- and (-)-AMPT has been investigated by chemical ionization gas chromatography mass spectrometry (c.i.g.c.m.s.). Two h after the administration of (+)- or (-)-AMPT (5 mg kg-1 i.p.), the concentrations of the isomers in striatal tissue were approximately equal; 18 h later, the concentration of the (+)-isomer was 10 times that of the (-)-isomer. The concentrations of AMPO in the striatum and hypothalamus 20 h after administration of (+)-AMPT were 68 ng g-1 and 484 ng g-1 respectively. After the administration of the (-)-isomer of AMPT, small quantities of AMPO were detected in both brain areas. Twenty h after the last of 7 daily injections of (+)-Amphet (5 mg kg-1, i.p.), the concentration of AMPO in the hypothalamus was 5.4 times the concentration at 20 h after one injection. In the striatum, the corresponding ratio for AMPO was 3.5 and for AMPT was 2.5. These data indicate that, although both isomers of AMPT formed from Amphet administered systemically, cross the blood brain barrier, the (+)-isomers AMPT and AMPO are preferentially stored in striatal and hypothalamic aminergic nerve terminals. The accumulations of AMPT and AMPO in rat striatum and hypothalamus after chronic administration of Amphet demonstrates that these metabolites persist in neuronal storage in these brain areas for days after administration. The half-lives of (+)-AMPT and (+)-AMPO in striatal neuronal storage, calculated from this data, were 1.5 days and 2.5 days, respectively. The corresponding half-life for hypothalamic (+)-AMPO was 7 days. 7. These findings suggest the involvement of accumulated AMPT and AMPO in the development of behavioural augmentation to repeated injections of Amphet (Randrup & Munkvad, 1970).
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Anfetamina/metabolismo , Compuestos de Bencilo/metabolismo , Cuerpo Estriado/metabolismo , Hipotálamo/metabolismo , Octopamina/análogos & derivados , Tiramina/análogos & derivados , Anfetamina/farmacología , Animales , Semivida , Hidroxilación , Masculino , Ratas , Estereoisomerismo , Tiramina/metabolismo , Tiramina/farmacologíaRESUMEN
The concentration in rat striatum of the meta and para isomers of tyramine and alpha-methyltyramine, after the administration of (+)-amphetamine, alpha-methyl-p-tyrosine (AMPT) and alpha-methylphenylalanine (AMPA) has been determined using chemical ionization gas chromatography mass spectrometry (c.i.g.c.m.s.). Twenty hours after the last of 7 daily injections of (+)-amphetamine (5 mg kg-1 i.p.) the concentration of alpha-methyl-p-tyramine in striatal tissue increased twofold compared to the concentration 20 h after a single injection. In contrast the concentration of alpha-methyl-m-tyramine did not change. alpha-Methyl-m-tyramine and alpha-methyldopamine were found in the striatum at concentrations of 42 ng g-1 and 13.5 ng g-1 respectively after treatment of rats 20 h before with AMPA (100 mg kg-1 i.p.). After treatment with AMPT (100 mg kg-1, 20 h before decapitation) only the para isomer of alpha-methyltyramine could be detected (13.7 ng g-1) although the striatal concentration of alpha-methyldopamine was 274 ng g-1, a level 20 times greater than that observed after AMPA treatment. The combined administration of both AMPT and AMPA (100 mg kg-1 each, 20 h) resulted in a reduction of the striatal concentration of alpha-methyl-m-tyramine but not alpha-methyl-p-tyramine. These data suggest that alpha-methyl-m-tyramine in rat striatum is formed by the enzyme tyrosine hydroxylase on substrate AMPA, rather than by ring dehydroxylation of alpha-methyldopa and alpha-methyldopamine. Significant reductions in the striatal concentrations of m-tyramine 2 h after the administration of AMPT, suggest that tyrosine hydroxylase is involved similarly in the production of m-tyramine.
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Anfetamina/farmacología , Anfetaminas/análisis , Cuerpo Estriado/efectos de los fármacos , Metiltirosinas/farmacología , Fenilalanina/análogos & derivados , Tiramina/análisis , p-Hidroxianfetamina/análisis , Animales , Cuerpo Estriado/análisis , Masculino , Fenilalanina/farmacología , Ratas , alfa-Metiltirosina , p-Hidroxianfetamina/metabolismoRESUMEN
Recent studies have mapped two susceptibility loci which appear to account for familial multinodular goitre (MNG1) and a variant of familial papillary thyroid cancer (PTC), with associated multinodular goitre (TCO). A Tasmanian family (Tas1) has been identified with an autosomal dominant form of PTC. This study has examined the MNG1 and TCO loci to determine if they are similarly predisposing the Tas1 family to PTC. Linkage analysis using identical microsatellite markers described in the two previous studies was used to determine the significance of these loci in the Tasmanian family. The resultant LOD scores were sufficiently negative using multipoint parametric analysis to exclude these two loci from involvement in the Tasmanian family. In addition, six candidate genes, RET, TRK, MET, TSHR, APC and PTEN were also excluded as susceptibility genes in Tas1 by using microsatellites that are positioned in or in close proximity to these genes. These results suggest that there are at least three susceptibility genes that predispose families to familial PTC.
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Carcinoma Papilar/genética , Neoplasias de la Tiroides/genética , Femenino , Ligamiento Genético , Predisposición Genética a la Enfermedad , Humanos , Masculino , Repeticiones de Microsatélite , Linaje , TasmaniaRESUMEN
The components of the mucus skin secretions from eight species of trunkfish found in the coastal waters of Australia were analyzed by combined chemical ionization-gas chromatography mass spectrometry. The species investigated were Anoplacapros lenticularis, Aracana aurita, Aracana ornata, Lactoria fornasini, Ostracion cubicus, Rhinesomas reipublicae, Strophiurichthys inermis and Strophiurichthys robustus. The beta-substituted choline chloride esters (mainly acetoxy, but with some species having butyryloxy, valeryloxy and one species with caproyloxy) of palmitic acid were the predominant components in almost all cases. High concentrations of monounsaturated palmitic acid were present in S. inermis and S. robustus. Trace quantities of C14, C17 and C18 choline chloride esters were also detected as were compounds where the choline moiety was modified by addition of one extra carbon.
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Peces/metabolismo , Toxinas Marinas/análisis , Moco/metabolismo , Piel/metabolismo , Animales , Colina/análisis , Cromatografía en Capa Delgada , Cromatografía de Gases y Espectrometría de Masas , Toxinas Marinas/toxicidadRESUMEN
Direct measurement by gas chromatography methane chemical ionization mass spectrometry of alpha-methyldopamine and alpha-methylnorepinephrine in rat striatum has shown the failure of these compounds to be accumulated in vivo after chronic administration of d-amphetamine despite the accumulation of alpha-methyltyramine, an immediate in vitro precursor. Further, both alpha-methyldopamine and alpha-methyltyramine accumulate in rat striatum after administration of alpha-methyltyrosine. These data suggest that, after administration of alpha-methyltyrosine, alpha-methyldopamine is formed via decarboxylation of alpha-methyldopa and not from hydroxylation of alpha-methyltyramine. Finally, our results indicate that alpha-methyldopamine does not play a role in the development of tolerance to d-amphetamine.
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Cuerpo Estriado/metabolismo , Desoxiepinefrina/análogos & derivados , Dextroanfetamina/metabolismo , Dopamina/análogos & derivados , Animales , Cromatografía de Gases , Descarboxilación , Desoxiepinefrina/biosíntesis , Masculino , Metildopa/metabolismo , Metiltirosinas/metabolismo , Nordefrin/metabolismo , Ratas , Factores de Tiempo , alfa-Metiltirosina , p-Hidroxianfetamina/metabolismoRESUMEN
The effect of the invertebrate octopamine agonists chlordimeform and clonidine on the concentration and turnover of p-octopamine and m- and p-tyramine was determined in rat hypothalamus and striatum. Clonidine (0.25 mg/Kg, s.c.) did not alter the concentration of p-octopamine in the hypothalamus or p-tyramine in the striatum. Administration of chlordimeform (50 mg/Kg, i.p.) resulted in an increase in p- and m-tyramine concentrations in the striatum but not that of p-octopamine in the hypothalamus. This increase in the tyramine isomers is consistent with the ability of chlordimeform and its metabolite, demethylchlordimeform, to inhibit monoamine oxidase (MAO). The concurrent administration of chlordimeform (50 mg/Kg, i.p.) and pargyline (75 mg/Kg, i.p.) produced a significant decrease in the accumulation of octopamine in the hypothalamus but not in the striatum. In contrast, the concurrent administration of clonidine (0.25 mg/Kg, s.c.) and pargyline (75 mg/Kg, i.p.) caused a significant decrease in the accumulation of octopamine in the striatum but not hypothalamus. These results show that the turnover of octopamine in the hypothalamus and striatum is decreased by chlordimeform and clonidine, respectively. Further, clonidine is known to modulate the turnover of amines in mammalian noradrenergic nerve terminals by an action at presynaptic adrenergic receptors. These data suggest that two mechanisms, one involving presynaptic adrenergic receptors in the striatum, and the other involving as yet unidentified receptors in the hypothalamus, modulate the turnover of octopamine in the mammalian brain.
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Amidinas/farmacología , Clorfenamidina/farmacología , Clonidina/farmacología , Cuerpo Estriado/metabolismo , Hipotálamo/metabolismo , Octopamina/metabolismo , Animales , Cuerpo Estriado/efectos de los fármacos , Hipotálamo/efectos de los fármacos , Masculino , Inhibidores de la Monoaminooxidasa/farmacología , Norepinefrina/metabolismo , Pargilina/farmacología , Ratas , Ratas Endogámicas , Tiramina/metabolismoRESUMEN
The concentration in brain of both octopamine (OCT) and tyramine (TYR) was significantly increased in rats 8 weeks after portal-systemic bypass. This suggests that the increase in OCT is secondary to increased decarboxylation of tyrosine to TYR. However, the role these neuroamines, particularly OCT, play in the development of hepatic encephalopathy remains controversial.
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2-Hidroxifenetilamina/metabolismo , Encéfalo/metabolismo , Octopamina/análogos & derivados , Fenetilaminas/metabolismo , Sistema Porta/cirugía , Vena Porta/cirugía , Tiramina/metabolismo , 2-Hidroxifenetilamina/análogos & derivados , Animales , Peso Corporal , Deuterio , Cromatografía de Gases y Espectrometría de Masas/métodos , Hígado/anatomía & histología , Masculino , Tamaño de los Órganos , Ratas , Ratas EndogámicasRESUMEN
OBJECTIVE: To outline the difficulties and suggest potential solutions in anthropometric assessment of adolescents during humanitarian emergencies. DESIGN: Literature review. SETTING: Multiple settings in which the nutritional status of adolescents has been assessed using anthropometric measurements. SUBJECTS: Adolescents in multiple populations. INTERVENTIONS: None. RESULTS: The use of anthropometry may be more difficult in adolescents than in other age groups because anthropometric indices in normally nourished adolescents change with age and sexual development. Moreover, survey and reference populations may differ in the age at which certain pubertal landmarks are attained, requiring adjustment for differences between survey and reference populations. Adolescent populations may also differ by ethnicity in various body proportions that affect anthropometric indices. Adjustment may be required when the body proportions of adolescents in the reference population differ from those in the population assessed. CONCLUSIONS: Although no definitive recommendation can be made regarding which anthropometric indices are the most appropriate for adolescents, some revisions may improve current practices. Weight-for-height could be used for prepubertal adolescents and body mass index could be used for postpubertal adolescents. Because cut-off points are age-specific, age should be collected as accurately as possible for all adolescents measured during screening or survey activities. The WHO-recommended reference population of US adolescents is inappropriate in most populations of adolescents. Adolescents should never undergo nutritional assessment in isolation; other population subgroups should be included, and other health, nutrition and food data should be collected at the same time. SPONSORSHIP: The United Nations Administrative Committee on Coordination/Sub-Committee on Nutrition.
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Antropometría , Trastornos Nutricionales/diagnóstico , Estado Nutricional , Adolescente , Adulto , Factores de Edad , Estatura , Peso Corporal , Urgencias Médicas , Etnicidad , Femenino , Humanos , Masculino , Evaluación Nutricional , Trastornos Nutricionales/clasificación , Estándares de Referencia , Maduración Sexual , Organización Mundial de la SaludRESUMEN
A technique using gas chromatography-mass spectrometry and deuterated internal standards is described for the quantitation in brain tissue of four constituents of the intoxicating beverage kava. Dihydrokawain, kawain, desmethoxyyangonin, and yangonin were administered ip to mice at a dosage of 100 mg/kg. At specific time intervals (5, 15, 30, and 45 min), the mice were sacrificed and the brain concentrations of these four compounds determined. After 5 min, dihydrokawain and kawain attained maximum concentrations of 64.7 +/- 13.1 and 29.3 +/- 0.8 ng/mg wet brain tissue, respectively, and were rapidly eliminated. In contrast, desmethoxyyangonin and yangonin had poorly defined maxima corresponding to concentrations of 10.4 +/- 1.5 and 1.2 +/- 0.3 ng/mg wet brain tissue, respectively, and these compounds were more slowly eliminated from brain tissue. When crude kava resin was administered ip at a dosage of 120 mg/kg, the concentration in brain of kawain and yangonin markedly increased (2 and 20 times, respectively) relative to the values measured from their individual injection. In contrast, dihydrokawain and desmethoxyyangonin, after the administration of crude resin, remained at the percentage incorporation into brain tissue established for their individual ip injection.
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Bebidas/análisis , Encéfalo/metabolismo , Extractos Vegetales/análisis , Animales , Cromatografía de Gases y Espectrometría de Masas , Kava , Masculino , Ratones , Ratones Endogámicos BALB C , Plantas Medicinales , Resinas de Plantas/análisisRESUMEN
The New Zealand environment is low in selenium and iodine, and is therefore ideally suited for the study of these anionic trace elements. The aim of this study was to determine urinary excretion of selenium and iodine during pregnancy and postpartum as part of an investigation of the influence of pregnancy and lactation on selenium metabolism in women of low selenium status. In a double-blind placebo-controlled study, 35 women in the earliest stages of pregnancy and 17 non-pregnant women were recruited in Dunedin, New Zealand. Eighteen pregnant women received 50 microg selenium as L-selenomethionine, while the others received a placebo daily during pregnancy and 12 months postpartum. The non-pregnant women received the supplement, serving as a positive control. Blood samples and twenty-four hour urine samples were collected monthly during pregnancy and at 3, 6, and 12 months postpartum for analysis of selenium and iodine. Selenium content in plasma and urinary excretion of selenium fell during pregnancy; however, total excretion of selenium was greater during pregnancy than postpartum. Urinary iodine excretion was much lower than reported previously in New Zealand. Due to large intra- and inter-subject variability, no trends in iodide excretion were observed. Factors which influence urinary excretion of selenium include dietary intake, but more closely, plasma concentrations of selenium (which is probably related to total selenium pool), creatinine excretion and therefore lean body mass, and glomerular filtration rate. The exact mechanism and sequence of events remains unclear and future studies incorporating new speciation techniques are necessary.
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Yodo/orina , Lactancia/orina , Embarazo/orina , Selenio/orina , Creatina/metabolismo , Creatina/orina , Femenino , Humanos , Yodo/metabolismo , Riñón/metabolismo , Tasa de Depuración Metabólica/fisiología , Valores de Referencia , Selenio/sangre , Selenio/farmacocinética , Oligoelementos/metabolismo , Oligoelementos/orinaRESUMEN
The combination of large doses of sodium bicarbonate and the potent narcotic, etorphine, has reportedly been given to racehorses in attempts to improve their performance and also to "mask" the presence of etorphine in urine samples. The increased urinary output and pH associated with sodium bicarbonate (approximately 500 g) administration may reduce the urinary concentration of etorphine, making it more difficult to detect. Our experiment was designed to examine the effects of this combination. Six Thoroughbred horses were used in a latin-square design with three horse pairs and three treatments consisting of the following: etorphine (20 micrograms), etorphine (20 micrograms) plus sodium bicarbonate (1.0 g/kg), and etorphine (20 micrograms) plus sodium chloride (0.7 g/kg). Sodium chloride was used to distinguish between the urinary alkalinizing effects of sodium bicarbonate and the diuretic effects associated with the large electrolyte load. Venous blood and urine samples were collected prior to and for 24 h post-treatment. Sodium bicarbonate produced a significant metabolic alkalosis and an increase in urine pH. Both sodium bicarbonate and sodium chloride produced a profound diuresis. After sodium bicarbonate and sodium chloride treatments, the urinary concentration of etorphine, measured by radioimmunoassay (RIA), was reduced and in some cases could not be detected. Extraction of the urine samples, prior to RIA analysis, increased the sensitivity of the assay and in most cases gave a positive result. We conclude that the coadministration of etorphine and sodium bicarbonate or sodium chloride can make the detection of etorphine more difficult because of the dilutional effects associated with the administration of a large electrolyte load.