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1.
J Endocrinol Invest ; 39(3): 315-22, 2016 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-26243508

RESUMEN

INTRODUCTION: The cortisol, cortisone, corticosterone, and CBG responses to exercise in the AM and PM have not been described. This study examined the response of these glucocorticoids and CBG to intense exercise in 12 endurance-trained men in plasma (Pl) and saliva (Sa). METHODS: Each subject completed treadmill exercise in the morning and evening. Paired blood and Sa samples were obtained at rest before and after exercise. RESULTS: Significant time effect existed for Pl-cortisol and Sa-cortisol from baseline in the AM and PM (p < 0.01). Pl-cortisone and CBG significantly increased in the PM (p < 0.01). Pl-corticosterone increased in the AM and PM (p < 0.01). Unlike Pl-cortisone, Sa-cortisone was significantly higher in the AM compared to the PM, increasing in the AM and PM (All p < 0.01). Strong associations were found between Pl-cortisol and Sa-cortisol (r = 0.81, p < 0.0001), Pl-cortisol and Sa-cortisone (r = 0.81, p < 0.0001). CONCLUSIONS: (1) Intense EX induces a similar increase in Pl-cortisone (~90 %) and corticosterone (~200 %) in the AM and PM, whereas exercise increases CBG in the PM, but not in the AM; (2) vigorous exercise increases Sa-cortisone; (3) Sa-cortisone and cortisol are equally strongly correlated to Pl-cortisol, suggesting a significant role for Sa-cortisone as a novel marker of free cortisol during exercise.


Asunto(s)
Biomarcadores/metabolismo , Corticosterona/metabolismo , Cortisona/metabolismo , Ejercicio Físico/fisiología , Plasma/metabolismo , Saliva/metabolismo , Adolescente , Adulto , Ritmo Circadiano , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Adulto Joven
2.
Can Respir J ; 18(6): 321-6, 2011.
Artículo en Inglés | MEDLINE | ID: mdl-22187687

RESUMEN

BACKGROUND: Currently, no reference or normative values for spirometry based on a randomly selected Canadian population exist. OBJECTIVE: The aim of the present analysis was to construct spirometric reference values for Canadian adults 20 to 90 years of age by combining data collected from healthy lifelong nonsmokers in two population-based studies. METHOD: Both studies similarly used random population sampling, conducted using validated epidemiological protocols in the Canadian Obstructive Lung Disease study, and the Lung Health Canadian Environment study. Spirometric lung function data were available from 3042 subjects in the COLD study, which was completed in 2009, and from 2571 subjects in the LHCE study completed in 1995. A total of 844 subjects 40 to 90 years of age, and 812 subjects 20 to 44 years of age, were identified as healthy, asymptomatic, lifelong nonsmokers, and provided normative reference values for spirometry. Multiple regression models were constructed separately for Caucasian men and women for the following spirometric parameters: forced expiratory volume in 1 s (FEV(1)), forced vital capacity (FVC) and FEV(1)/FVC ratio, with covariates of height, sex and age. Comparison with published regression equations showed that the best agreement was obtained from data derived from random populations. RESULTS: The best-fitting regression models for healthy, never-smoking, asymptomatic European-Canadian men and women 20 to 90 years of age were constructed. When age- and height-corrected FEV(1), FVC and FEV(1)/FVC ratio were compared with other spirometry reference studies, mean values were similar, with the closest being derived from population-based studies. CONCLUSION: These spirometry reference equations, derived from randomly selected population-based cohorts with stringently monitored lung function measurements, provide data currently lacking in Canada.


Asunto(s)
Técnicas de Apoyo para la Decisión , Volumen Espiratorio Forzado , Capacidad Vital , Población Blanca , Adulto , Anciano , Anciano de 80 o más Años , Canadá , Estudios Transversales , Femenino , Encuestas Epidemiológicas , Humanos , Masculino , Persona de Mediana Edad , Modelos Estadísticos , Valores de Referencia , Análisis de Regresión , Espirometría
3.
Int J Tuberc Lung Dis ; 12(5): 480-92, 2008 May.
Artículo en Inglés | MEDLINE | ID: mdl-18419882

RESUMEN

BACKGROUND: Many molecular epidemiology studies have been conducted to identify risk factors for clustering of tuberculosis (TB) cases in the population. OBJECTIVE: To estimate the impact of commonly investigated risk factors on TB clustering. METHODS: Ten electronic databases were searched up to January 2006 along with a hand search of the International Journal of Tuberculosis and Lung Disease and bibliographies of review articles. Meta-analyses of odds ratios (ORs) for various risk factors were conducted using random effect models, stratified by TB incidence. Meta-regressions were employed to account for the heterogeneity in clustering proportions and the magnitudes of risk. FINDINGS: The TB clustering proportion varied greatly (7.0-72.3%) among 36 studies in 17 countries. In multiple meta-regression analyses, high TB incidence, mean cluster size and conventional contact tracing were significantly associated with higher clustering. The pooled ORs (95%CIs) for low and high/intermediate TB incidence studies, using a cut off of 25/100000 per year, were 3.4 (2.7- 4.2) and 1.6 (1.3-2.1) for local-born status, 1.6 (1.5-1.7) and 1.7 (1.3-2.2) for pulmonary TB and 1.2 (1.1-1.3) and 1.3 (1.1-1.7) for smear-positive cases, respectively. Male sex, local birth, alcohol abuse and injection drug use were significantly higher risks in low TB incidence studies than in the high/intermediate ones. INTERPRETATION: Meta-analyses yielded significant estimates of ORs for several risk factors across both levels of TB incidence. Alcohol abuse, injection drug use and homelessness--all characteristics of marginalized populations--were found to be consistently significant in populations of low TB incidence. More research is needed to better understand TB transmission dynamics in high-burden countries.


Asunto(s)
Mycobacterium tuberculosis/genética , Tuberculosis/epidemiología , Tuberculosis/transmisión , Análisis por Conglomerados , Dermatoglifia del ADN , Salud Global , Humanos , Incidencia , Análisis de Regresión , Factores de Riesgo , Tuberculosis/microbiología
4.
J Anal Toxicol ; 25(7): 538-49, 2001 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-11599597

RESUMEN

Current technology establishes marijuana use based upon detection of the pharmacologically inactive cannabinoid metabolite (11-nor-delta9-carboxy-tetrahydrocannabinol-9-carboxylic acid, THC-COOH) in urine. No accurate prediction of time of use is possible because THC-COOH has a half-life of 6 days. To determine if a temporal relationship between marijuana use and metabolite excretion patterns could be established, eight healthy user-volunteers (18-35 years old) smoked marijuana cigarettes containing 0% (placebo), 1.77%, and 3.58% delta9-tetrahydrocannabinol (THC). Plasma and urine were collected prior to smoking, 5 min after smoking, and hourly thereafter for 8 h for measurement of cannabinoid concentrations by gas chromatography-mass spectrometry. Mathematical models proposed for determination of recent marijuana use were applied to data from this study and verified the temporal use of marijuana. One subject, who later admitted chronic marijuana use (urine baseline THCCOOH, 529.2 ng/mL; plasma, 75.5 ng/mL), excreted 8beta-dihydroxy-THC, peaking 2 h postsmoking (92.3 ng/mL). Urinary THC, the psychoactive component of marijuana, concentrations peaked 2 h after smoking and declined to assay limit of detection (LOD) (1.5 ng/mL) by 6 h. 11-Hydroxy-delta9-tetrahydrocannabinol (11-OH-THC) and THCCOOH were detectable for the entire 8-h testing period but continued to decrease. Urinary concentrations of THC greater than 1.5 ng/mL suggests marijuana use during the previous 8-h time period.


Asunto(s)
Dronabinol/análogos & derivados , Dronabinol/sangre , Dronabinol/orina , Alucinógenos/sangre , Alucinógenos/orina , Fumar Marihuana , Adolescente , Adulto , Dronabinol/farmacocinética , Femenino , Cromatografía de Gases y Espectrometría de Masas , Semivida , Alucinógenos/farmacocinética , Humanos , Masculino , Detección de Abuso de Sustancias , Factores de Tiempo
5.
J Addict Dis ; 19(3): 71-87, 2000.
Artículo en Inglés | MEDLINE | ID: mdl-11076121

RESUMEN

Stringent exclusion criteria in drug abuse research are necessary to protect against methodological confounds compromising the interpretation of findings. However, reliance on self-report screening may fail to detect important exclusion variables. We compared three levels of exclusion criteria screening in a study of neurophysiological/neurocognitive sequelae of chronic marihuana use in normals. LEVEL 1 (self-report) consisted of telephone pre-screening. LEVEL 2 (also self-report) involved in-depth personal interviews. LEVEL 3 consisted of several direct examination assessments including a medical/psychiatric examination by a board certified psychiatrist, eight weeks of twice per week urine drug screens, an EEG exam and eight hours of neuropsychological testing. Results indicated that 39.0% of subjects passing self-report screening had significant exclusion criteria findings that were only detected through LEVEL 3 direct examination procedures. Of all subjects found to have exclusion criteria after being provisionally accepted following LEVEL 1 telephone pre-screening, 55.7% were detected only through more rigorous LEVEL 3 direct examination screening methods.


Asunto(s)
Abuso de Marihuana/epidemiología , Autoevaluación (Psicología) , Detección de Abuso de Sustancias , Adolescente , Adulto , Encéfalo/fisiología , Análisis Costo-Beneficio , Electroencefalografía , Potenciales Evocados/fisiología , Femenino , Humanos , Masculino , Abuso de Marihuana/diagnóstico , Abuso de Marihuana/economía
6.
Eur Radiol ; 10(1): 89-91, 2000.
Artículo en Inglés | MEDLINE | ID: mdl-10663721

RESUMEN

The radiological features of seven cases of pelvic digit discovered incidentally on plain radiographs are described and differentiation from other causes of new bone formation is discussed. Its recognition as a benign anomaly is important to avoid unnecessary investigation or intervention. An embryological theory of development of pelvic digit is proposed.


Asunto(s)
Huesos/anomalías , Huesos/diagnóstico por imagen , Adulto , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Pelvis , Radiografía
7.
Pediatr Radiol ; 30(12): 861-5, 2000 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-11149096

RESUMEN

Myelinoclastic diffuse sclerosis (MDS, Schilder's disease) is a rare CNS demyelinating disorder affecting mainly children and usually presenting as an intracranial mass lesion. We report the first case of recurrent intracranial MDS where the third episode of demyelination involved the cervical spinal cord. This may represent a subset of the disease, which should be considered as Schilder's variant (childhood form) of multiple sclerosis.


Asunto(s)
Esclerosis Cerebral Difusa de Schilder/diagnóstico , Niño , Esclerosis Cerebral Difusa de Schilder/clasificación , Humanos , Imagen por Resonancia Magnética , Masculino , Esclerosis Múltiple/diagnóstico , Recurrencia , Tomografía Computarizada por Rayos X
8.
Oncogene ; 18(15): 2489-98, 1999 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-10229200

RESUMEN

dMax, a naturally occurring splice variant of the Myc binding protein Max, lacks the DNA binding basic region and helix 1 of the Helix-Loop-Helix domain; dMax interacts with c-Myc in vitro and in vivo, and inhibits E-box Myc site driven transcription in transient transfection assays. Here we have investigated the expression, function and interactions of dMax. RT/PCR analyses detected dmax mRNA in multiple tissues of the developing, newborn and adult mouse. Functionally, dMax reduced the ability of c-Myc to cooperate with the progression factor A-Myb to promote S phase entry of quiescent smooth muscle cells. In contrast, dMax failed to ablate inhibition of initiator element (Inr)-mediated transcription by c-Myc in Jurkat T cells. In in vitro protein:protein association assays, dMax interacted with c-Myc, N-Myc, L-Myc, Mad1, Mxi1, Mad3 and Mad4, but not with itself or wild-type Max. These interactions required an intact leucine zipper. Inhibition of E-box-mediated transactivation by induction of dMax overexpression resulted in apoptosis of WEHI 231 B cells. Thus, dMax is a widely expressed, naturally occurring protein, with the capacity to bind most members of the Myc/Max superfamily; dMax has little effect on Inr-mediated repression by c-Myc, but can significantly decrease E-box-mediated events promoting proliferation and cell survival.


Asunto(s)
Proteínas de Unión al ADN/genética , Proteínas de Unión al ADN/metabolismo , Genes myc , Empalme de Proteína , Secuencias Reguladoras de Ácidos Nucleicos , Factores de Transcripción , Animales , Apoptosis , Linfocitos B/patología , Factores de Transcripción Básicos con Cremalleras de Leucinas y Motivos Hélice-Asa-Hélice , Factores de Transcripción con Cremalleras de Leucina de Carácter Básico , División Celular/genética , Regulación del Desarrollo de la Expresión Génica , Secuencias Hélice-Asa-Hélice , Ratones , Músculo Liso Vascular/metabolismo , Transcripción Genética
9.
Am J Pathol ; 151(4): 891-6, 1997 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-9327720

RESUMEN

Recently we have demonstrated that inhibition of the nuclear factor (NF)-kappa B/Rel family of transcription factors induces apoptosis of B cells. Interestingly, mice lacking the relA gene encoding the p65 subunit of NF-kappa B exhibit embryonic lethality at days 15 to 16 of gestation, accompanied by massive destruction of liver via apoptosis. To determine whether p65 protein plays a direct role in hepatocyte survival, we employed a nontransformed murine hepatocyte (NMH) cell line, which maintains to a high degree the differentiated hepatocyte phenotype. Exponentially growing NMH cells were found to possess a constitutive level of functional classical (p50/p65) NF-kappa B as assayed by electrophoretic mobility shift analysis, antibody supershift, and transient transfection assays. Treatment of NMH cells with the proteasome inhibitor lactacystin, which prevents degradation of the NF-kappa B inhibitor proteins I kappa B, induced apoptosis. Direct inhibition of the endogenous NF-kappa B activity by microinjection of NMH cells with purified specific inhibitor I kappa B-alpha-glutathione-S-transferase fusion protein or an antibody against p65 protein induced apoptosis. These findings suggest that expression of NF-kappa B/Rel activity in murine hepatocytes acts directly to promote survival of these cells and suggest that apoptosis observed in hepatocytes of mice lacking relA is a direct effect of p65 deficiency.


Asunto(s)
Apoptosis , Proteínas de Unión al Calcio , Hígado/fisiología , FN-kappa B/antagonistas & inhibidores , Proteínas Proto-Oncogénicas/farmacología , Factores de Transcripción , Acetilcisteína/análogos & derivados , Acetilcisteína/farmacología , Animales , Apoptosis/fisiología , Línea Celular , Inhibidores de Cisteína Proteinasa/farmacología , Sondas de ADN/química , Glutatión Transferasa/genética , Glutatión Transferasa/farmacología , Hígado/citología , Hígado/efectos de los fármacos , Glicoproteínas de Membrana/fisiología , Ratones , Microinyecciones , Proteínas del Tejido Nervioso/fisiología , Proteínas Proto-Oncogénicas/genética , Proteínas Recombinantes de Fusión/genética , Proteínas Recombinantes de Fusión/farmacología , Sinaptotagmina I , Sinaptotagminas , Factor de Transcripción ReIB
10.
Cell Growth Differ ; 8(10): 1049-59, 1997 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-9342183

RESUMEN

Treatment of hepatocytes with transforming growth factor beta1 (TGF-beta1) induces growth arrest, which is followed by extensive cell death by apoptosis. Previously, we found that TGF-beta1 down-modulates nuclear factor (NF)-kappaB/Rel activity in murine B cell lymphomas, inducing apoptosis. Furthermore, p65 (RelA)-deficient mice died during gestation due to apoptosis of liver cells. Here we have explored the effects of TGF-beta1 on hepatocytes, using two untransformed murine hepatocyte cell lines, AML-12 and NMH, which constitutively express classical NF-kappaB. TGF-beta1 treatment caused increased NF-kappaB binding that was followed by a dramatic decrease in NF-kappaB levels that preceded apoptosis. Ectopic c-Rel expression ablated apoptosis induced by TGF-beta1. The down-regulation in NF-kappaB activity correlated with elevated IkappaB-alpha expression due to hypophosphorylation and increased IkappaB-alpha protein stability. Thus, NF-kappaB factor expression acts directly to promote liver cell survival. Furthermore, these findings characterize a novel signaling pathway for TGF-beta1 in epithelial cells involving down-regulation of NF-kappaB/Rel factors activity through posttranslational modification of IkappaB-alpha protein.


Asunto(s)
Apoptosis , Hígado/metabolismo , FN-kappa B/metabolismo , Proteínas Proto-Oncogénicas/metabolismo , Factor de Crecimiento Transformador beta/antagonistas & inhibidores , Animales , Apoptosis/genética , Línea Celular , Proteínas de Unión al ADN/metabolismo , Regulación hacia Abajo , Immunoblotting , Hígado/efectos de los fármacos , Ratones , Fosforilación , Proteínas Proto-Oncogénicas/genética , Proteínas Proto-Oncogénicas c-rel , Transducción de Señal , Estaurosporina/farmacología , Factores de Tiempo , Factor de Transcripción ReIB , Factores de Transcripción/metabolismo , Transfección , Factor de Crecimiento Transformador beta/farmacología
12.
Mol Cell Biol ; 16(9): 5015-25, 1996 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-8756660

RESUMEN

Treatment of WEHI 231 immature B-lymphoma cells with an antibody against their surface immunoglobulin (anti-Ig) induces apoptosis and has been studied extensively as a model of B-cell tolerance. Anti-Ig treatment of exponentially growing WEHI 231 cells results in an early transient increase in c-myc expression that is followed by a decline to below basal levels; this decrease in c-myc expression immediately precedes the induction of cell death. Here we have modulated NF-kappaB/Rel factor activity, which regulates the rate of c-myc gene transcription, to determine whether the increase or decrease in c-Myc-levels mediates apoptosis in WEHI 231 cells. Addition of the serine/threonine protease inhibitor N-tosyl-L-phenylalanine chloromethyl ketone (TPCK), which blocks the normally rapid turnover of the specific inhibitor of NF-kappaB/Rel IkappaBalpha in these cells, caused a drop in Rel-related factor binding. TPCK treatment resulted in decreased c-myc expression, preventing the usual increase seen following anti-Ig treatment. Whereas inhibition of the induction of c-myc expression mediated by anti-Ig failed to block apoptosis, reduction of c-myc expression in exponentially growing WEHI 231 cells induced apoptosis even in the absence of anti-Ig treatment. In WEHI 231 clones ectopically expressing c-Myc, apoptosis induced by treatment with TPCK or anti-Ig was significantly diminished and cells continued to proliferate. Furthermore, apoptosis of WEHI 231 cells ensued following enhanced expression of Mad1, which has been found to reduce functional c-Myc levels. These results indicate that the decline in c-myc expression resulting from the drop in NF-kappaB/Rel binding leads to activation of apoptosis of WEHI 231 B cells.


Asunto(s)
Apoptosis/genética , Linfocitos B/metabolismo , Proteínas Portadoras , Regulación Neoplásica de la Expresión Génica , Proteínas de Neoplasias/biosíntesis , Proteínas Proto-Oncogénicas c-myc/biosíntesis , Proteínas Represoras , Animales , Apoptosis/efectos de los fármacos , Linfocitos B/efectos de los fármacos , Proteínas de Ciclo Celular , Citomegalovirus/genética , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Humanos , Linfoma de Células B/patología , Ratones , FN-kappa B/metabolismo , Proteínas de Neoplasias/genética , Proteínas Nucleares/genética , Fosfoproteínas/genética , Unión Proteica/efectos de los fármacos , Proteínas Proto-Oncogénicas/metabolismo , Proteínas Proto-Oncogénicas c-myc/genética , Proteínas Proto-Oncogénicas c-rel , Proteínas Recombinantes de Fusión/metabolismo , Clorometilcetona de Tosilfenilalanila/farmacología , Factores de Transcripción/metabolismo , Células Tumorales Cultivadas/efectos de los fármacos
13.
EMBO J ; 15(17): 4682-90, 1996 Sep 02.
Artículo en Inglés | MEDLINE | ID: mdl-8887559

RESUMEN

Apoptosis of the WEHI 231 immature B cell lymphoma line following membrane interaction with an antibody against the surface IgM chains (anti-IgM) is preceded by dramatic changes in Nuclear Factor-kappaB (NF-kappaB)/ Rel binding activities. An early transient increase in NF-kappaB/Rel binding is followed by a significant decrease in intensity below basal levels. Here we have explored the role of these changes in Rel-related factors in B cell apoptosis. Treatment of WEH1 231 cells with N-tosyl-L-phenylalanine chloromethyl ketone (TPCK), a protease inhibitor which prevents degradation of the inhibitor of NF-kappaB (IkappaB)-alpha, or with low doses of pyrrolidinedithiocarbamate (PDTC) selectively inhibited NF-kappaB/Rel factor binding and induced apoptosis. Bcl-XL expression protected WEHI 231 cells from apoptosis induced by these agents. Microinjection of WEHI 231 cells with either IkappaB-alpha-GST protein or a c-Rel affinity-purified antibody induced apoptosis. Ectopic c-Rel expression ablated apoptosis induced by TPCK or anti-IgM. Treatment of BALENLM 17 and A20 B lymphoma cells or normal murine splenic B lymphocytes with either TPCK or PDTC also resulted in apoptosis. These findings indicate that the drop in NF-kappaB/Rel binding following anti-IgM treatment activates apoptosis of WEHI 231 cells; furthermore, they implicate the NF-kappaB/Rel family in control of apoptosis of normal and transformed B cells.


Asunto(s)
Apoptosis , Linfocitos B/patología , FN-kappa B/antagonistas & inhibidores , Proteínas Proto-Oncogénicas c-bcl-2 , Factores de Transcripción , Animales , Inmunoglobulina M/efectos de los fármacos , Linfoma de Células B/patología , Ratones , Microinyecciones , FN-kappa B/metabolismo , Unión Proteica , Proteínas Proto-Oncogénicas/antagonistas & inhibidores , Proteínas Proto-Oncogénicas/metabolismo , Bazo/patología , Clorometilcetona de Tosilfenilalanila/farmacología , Factor de Transcripción ReIB , Células Tumorales Cultivadas , Proteína bcl-X
14.
J Anal Toxicol ; 19(5): 292-8, 1995 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-7500615

RESUMEN

Glucuronide conjugates of cannabinoids were previously identified in humans. For gas chromatographic-mass spectrometric (GC-MS) analysis of the unconjugated compounds in human urine, it is necessary to cleave the glucuronide moiety. Base hydrolysis and two forms of enzymatic hydrolysis were compared in this study to examine any quantitative differences between the hydrolysis methods. Human volunteers (n = 8) each smoked one marijuana cigarette containing 3.58% delta 9-tetrahydrocannabinol (THC) and submitted urine samples prior to smoking, 5 min after smoking, and hourly for 8 h thereafter. Urine (1 mL) was buffered to the optimum pH for each form of enzyme tested. beta-Glucuronidase from Escherichia coli (bacteria) or Helix pomatia (mollusk) was added to the specimens, followed by overnight incubation at 37 degrees C. Following hydrolysis, the samples were extracted using hexane-ethyl acetate (7:1) and derivatized with N,O-bis(trimethylsilyl)-trifluoroacetamide plus 1% trimethylchlorosilane, which converted the cannabinoids to their trimethylsilyl derivatives. GC-MS analysis revealed striking differences between the hydrolysis methods. Concentrations of unconjugated THC and 11-hydroxy-THC (11-OH-THC) using E. coli were significantly increased over all other methods tested (p < .05). These results demonstrate the species-dependent nature of glucuronidase activity in hydrolyzing THC and 11-OH-THC glucuronides and the ineffectiveness of base hydrolysis on these hydroxylated compounds. The need for further study to find the optimum conditions necessary for the complete hydrolysis of cannabinoid conjugates is suggested.


Asunto(s)
Dronabinol/orina , Dronabinol/análisis , Dronabinol/metabolismo , Femenino , Cromatografía de Gases y Espectrometría de Masas , Glucuronidasa , Humanos , Hidrólisis , Masculino
15.
Cell Growth Differ ; 6(4): 417-27, 1995 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-7794809

RESUMEN

Liver regeneration after two-thirds partial hepatectomy (PH) is a process in which quiescent, fully differentiated hepatocytes rapidly reenter the cell cycle and eventually divide until the original liver mass is restored. Although the exact nature of the growth-initiating signals is unknown, enhanced expression of growth-related genes has been detected during the first hour after operation. This suggests that activation of transcriptional and posttranscriptional regulatory factors is likely to be a very early event in liver regeneration. Here we report the rapid, transient induction of DNA binding by nuclear factor (NF)-kappa B (p50/p65 heterodimer) and p50 homodimers within 30 min after PH. We also detected binding of post-hepatectomy factor. NF-kappa B binding peaks at 1 h after PH before declining and is not induced by sham operation. Liver cell separation studies indicated that the binding activation occurs in hepatocytes, a conclusion further supported by cell culture studies using the hepatocyte cell line AML-12. Furthermore, studies with the liver epithelial cell line LE-6 indicated that these DNA-binding activities are mitogen inducible. One-third hepatectomy, a procedure which primes hepatocytes to respond to growth factors, also induced NF-kappa B binding. We also found that tumor necrosis factor alpha, which may be involved in the control of liver regeneration, rapidly induced NF-kappa B DNA-binding activities in intact animals, similar to those induced by PH. These results suggest that NF-kappa B binding may play a role in making hepatocytes competent to proliferate.


Asunto(s)
ADN/metabolismo , Regeneración Hepática , Hígado/metabolismo , FN-kappa B/metabolismo , Animales , Células Cultivadas , Ratas , Ratas Sprague-Dawley , Activación Transcripcional
16.
J Anat ; 185 ( Pt 3): 553-63, 1994 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-7649791

RESUMEN

The tylotrich-touch dome complexes of the rat were studied in detail at thoracic level, with two objectives: to follow the pattern of innervation of the individual complexes from birth to maturity and to determine the extent of overlap of the segmental nerves supplying them. Techniques included light and electron microscopy and histological observations following section of intercostal nerves. The touch domes were nearly always supplied from a single stem axon; as expected, their terminals increased in number in association with the differentiation of target Merkel cells from the epidermis. In general, they were supplied from the nearest segmental nerves. The tylotrich follicles were each supplied by several stem fibres. The number of palisade terminals applied to the epithelial root sheaths reached a maximum during the 2nd and 3rd postnatal weeks and declined during the following 2 wk. This overshoot can be regarded as another example of hyperinnervation found in the juvenile peripheral nervous system. During the period of decline, the stem fibres extended their territory, resulting in considerable overlap of the territories of the segmental nerves. By the beginning of the 8th week, overlap was relatively scanty, with an irregular distribution.


Asunto(s)
Mecanorreceptores/crecimiento & desarrollo , Piel/inervación , Animales , Mecanorreceptores/citología , Mecanorreceptores/ultraestructura , Microscopía Electrónica , Ratas , Piel/citología , Piel/crecimiento & desarrollo , Piel/ultraestructura
17.
Hepatology ; 18(6): 1422-31, 1993 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-8244268

RESUMEN

Transforming growth factor-alpha and hepatocyte growth factor are important stimulators of hepatocyte proliferation. In this series of experiments we sought to measure the expression of transforming growth factor-alpha mRNA by hepatocytes in response to toxic liver injury produced by carbon tetrachloride or galactosamine and to perform a more detailed analysis of transforming growth factor-alpha expression after partial hepatectomy. We also explored the interactions of transforming growth factor-alpha and hepatocyte growth factor in their effects on hepatocytes in vitro and tested the ability of these factors to stimulate endogenous transforming growth factor-alpha production by hepatocytes. In previous work we have used oligonucleotide probes to measure transforming growth factor-alpha mRNA expression after partial hepatectomy. In this study we used a rat transforming growth factor-alpha cDNA probe and found that the level of liver transforming growth factor-alpha mRNA increases 4 hr after partial hepatectomy, shows peak expression at 18 hr and returns to the normal level by 36 to 48 hr. Measurement of the corresponding peptide in the liver by means of radioimmunoassay shows that the level of transforming growth factor-alpha rises by 12 hr, peaks at 24 hr and remains significantly increased at 48 hr compared with the levels in sham-operated rats. Carbon tetrachloride and galactosamine are known to produce different patterns of acute liver injury, with maximal hepatocyte DNA synthesis at 48 hr and 5 days, respectively. After carbon tetrachloride administration the profiles of the transforming growth factor-alpha and hepatocyte growth factor mRNA expression are similar, each showing two peaks: the first at 12 hr and the second at 48 hr. In contrast, after galactosamine-induced liver injury the expression patterns of transforming growth factor-alpha and hepatocyte growth factor mRNAs differ: hepatocyte growth factor shows a major peak at 24 hr, with a smaller increase at 5 days, whereas transforming growth factor-alpha begins to increase after 2 days, with a single peak occurring at 5 days. In primary hepatocyte cultures, transforming growth factor-alpha and hepatocyte growth factor appear to have complementary effects. The maximal hepatocyte nuclear labeling index induced by hepatocyte growth factor was 42%; the addition of transforming growth factor-alpha increased this to 74%. Exogenous transforming growth factor-alpha, but not hepatocyte growth factor, stimulates the production of the transforming growth factor-alpha peptide by hepatocytes.(ABSTRACT TRUNCATED AT 400 WORDS)


Asunto(s)
Hepatectomía , Factor de Crecimiento de Hepatocito/farmacología , Regeneración Hepática , Hígado/efectos de los fármacos , Factor de Crecimiento Transformador alfa/metabolismo , Animales , Tetracloruro de Carbono/toxicidad , Células Cultivadas , Interacciones Farmacológicas , Receptores ErbB/metabolismo , Galactosamina/toxicidad , Hepatectomía/métodos , Factor de Crecimiento de Hepatocito/genética , Hígado/metabolismo , Hígado/patología , Masculino , ARN Mensajero/metabolismo , Ratas , Ratas Endogámicas , Factor de Crecimiento Transformador alfa/genética , Factor de Crecimiento Transformador alfa/farmacología
18.
Respir Med ; 87(6): 433-8, 1993 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-8105519

RESUMEN

OBJECTIVE: To determine the increase in FEV1 associated with increasing doses of inhaled terbutaline and salbutamol, the reproducibility of the increase in FEV1, and the reproducibility of the associated optimal bronchodilator dose, in patients with chronic airflow limitation (CAL). DESIGN: Double-blind, randomized, controlled trial examining spirometric response to cumulative doses of bronchodilators. PATIENTS AND SETTING: Patients with clinical diagnosis of CAL, FEV1 below 70% predicted, and FEV1 to FVC ratio less than 0.7 after administration of bronchodilator recruited from secondary care respirology practices. MEASURES OF OUTCOME: The estimates of maximum and optimal bronchodilation, as well as the associated drug dosages, were established in each patient on three occasions (twice on terbutaline and once on salbutamol). The 'optimal' drug dose was defined as the lowest dose associated with an FEV1 not exceeded by 50 ml on any other dose. MAIN RESULTS: Thirty-five patients completed the trial. FEV1 improved from 0.93 to a maximum of 1.191 with terbutaline (average of the two administrations) and from 0.951 to 1.141 with inhaled salbutamol (difference in increase in FEV1 between terbutaline and salbutamol P = 0.006). In less than 50% of cases administration of more than four puffs of bronchodilator resulted in FEV1 increase by more than 50 ml. The average dose of salbutamol and terbutaline associated with optimal bronchodilation were 430 micrograms and 1160 micrograms respectively. Patients varied widely in the optimal dose. Estimates of optimal dose were not reproducible (intraclass correlation coefficient < 0.5). CONCLUSION: Substantial incremental increase in FEV1 in response to increasing doses of beta-agonists beyond those commonly used in clinical practice is restricted to a minority of patients. Lack of reproducibility limits the clinical usefulness of establishing the optimal dose of beta-agonist for a given patient.


Asunto(s)
Agonistas Adrenérgicos beta/administración & dosificación , Enfermedades Pulmonares Obstructivas/tratamiento farmacológico , Administración por Inhalación , Anciano , Anciano de 80 o más Años , Albuterol/administración & dosificación , Método Doble Ciego , Esquema de Medicación , Femenino , Volumen Espiratorio Forzado/efectos de los fármacos , Humanos , Masculino , Persona de Mediana Edad , Ventilación Pulmonar/efectos de los fármacos , Reproducibilidad de los Resultados , Terbutalina/administración & dosificación
19.
J Pediatr ; 121(6): 951-5, 1992 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-1447665

RESUMEN

The effects of sepsis on carbohydrate metabolism were studied in preterm newborn infants (weight > 1.2 kg, appropriate for gestational age) without maternal endocrine problems who were being examined for infection. Plasma glucose, lactate, and insulin concentrations were measured at initial evaluation and then every 8 hours for a total of 48 hours. Blood, urine, and spinal fluid were obtained for culture and counterimmunoelectrophoresis. Dextrose was administered to each patient to maintain glucose levels in the normal range. Dextrose infusion rates were calculated in milligrams per kilogram per minute. Of the 29 infants, 6 had sepsis (positive culture and counterimmunoelectrophoresis results). Infants with sepsis had significant elevations of plasma lactate concentration (p < 0.003) but normal pH. The dextrose infusion rate was also significantly elevated in the infected infants (p < 0.01). No hypoglycemia or hyperglycemia was observed in either group. No significant difference in plasma insulin concentration was observed. We conclude that significant elevations in plasma lactate concentrations and dextrose infusion rate may be early clinical markers of neonatal sepsis in the first 48 hours of life.


Asunto(s)
Acidosis Láctica/sangre , Infecciones Bacterianas/sangre , Glucosa/administración & dosificación , Enfermedades del Prematuro/sangre , Acidosis Láctica/diagnóstico , Acidosis Láctica/epidemiología , Acidosis Láctica/terapia , Análisis de Varianza , Infecciones Bacterianas/diagnóstico , Infecciones Bacterianas/epidemiología , Infecciones Bacterianas/terapia , Biomarcadores/sangre , Glucemia/análisis , Humanos , Recién Nacido , Recien Nacido Prematuro , Enfermedades del Prematuro/diagnóstico , Enfermedades del Prematuro/epidemiología , Enfermedades del Prematuro/terapia , Insulina/sangre , Lactatos/sangre , Ácido Láctico , Factores de Tiempo
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