Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 96
Filtrar
2.
Endoscopy ; 41(11): 959-64, 2009 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-19802775

RESUMEN

BACKGROUND AND STUDY AIMS: Localized-type bile duct carcinoma (LBDC) is often accompanied by extensive intraepithelial tumor spread (ITS) of 2 cm or more, which makes radical resection more difficult. This retrospective case review compares the diagnostic accuracy of endoscopic retrograde cholangiography (ERC) and peroral cholangioscopy (POCS) to detect ITS beyond the visible LBDC. PATIENTS AND METHODS: Forty-four consecutive patients with LBDC diagnosed between April 2004 and October 2008 who underwent radical resection with histopathological analysis were included in this study. Extensive ITS was found histopathologically in one-third of the cases (32 %). The outcome parameters were the presence or absence of extensive ITS and the extent of extensive ITS proximal and distal to the main tumor. RESULTS: In six cases it was not possible to pass the cholangioscope through the tumor sites. ERC correctly identified the presence of extensive ITS in 11/14 cases and did not yield any false-positive results. The three cases in which ERC was negative were all correctly identified by POCS plus biopsy since the cholangioscope could be passed in all three cases. The extent of extensive ITS was correctly diagnosed by ERC alone, ERC with POCS, and ERC with POCS plus mapping biopsy in 22 %, 77 %, and 100 % of cases, respectively. CONCLUSIONS: The presence of extensive ITS was correctly detected in 80 % of cases by ERC alone. POCS with mapping biopsy provided perfect diagnostic accuracy not only of the presence or absence but also of the extent of extensive ITS. However, POCS has the limitation that the cholangioscope cannot be passed through the tumor sites in approximately 15 % of cases.


Asunto(s)
Neoplasias de los Conductos Biliares/patología , Carcinoma in Situ/patología , Colangiografía , Endoscopía del Sistema Digestivo , Anciano , Anciano de 80 o más Años , Neoplasias de los Conductos Biliares/diagnóstico por imagen , Carcinoma in Situ/diagnóstico por imagen , Femenino , Humanos , Masculino , Persona de Mediana Edad , Invasividad Neoplásica , Estudios Retrospectivos
3.
Kidney Int ; 71(8): 738-43, 2007 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-17264878

RESUMEN

Skeletal resistance to parathyroid hormone (PTH) is well known to the phenomenon in chronic renal failure patient, but the detailed mechanism has not been elucidated. In the process of analyzing an animal model of renal failure with low bone turnover, we demonstrated decreased expression of PTH receptor (PTHR) accompanying renal dysfunction in this model. In the present study, we focused on the accumulation of uremic toxins (UTx) in blood, and examined whether indoxyl sulfate (IS), a UTx, is associated with PTH resistance. We established primary osteoblast cultures from mouse calvariae and cultured the cells in the presence of IS. The intracellular cyclic adenosine 3',5' monophosphate (cAMP) production, PTHR expression, and free radical production in the primary osteoblast culture were studied. We found that the addition of IS suppressed PTH-stimulated intracellular cAMP production and decreased PTHR expression in this culture system. Free radical production in osteoblasts increased depending on the concentration of IS added. Furthermore, expression of organic anion transporter-3 (OAT-3) that is known to mediate cellular uptake of IS was identified in the primary osteoblast culture. These results suggest that IS taken up by osteoblasts via OAT-3 present in these cells augments oxidative stress to impair osteoblast function and downregulate PTHR expression. These finding strongly suggest that IS accumulated in blood due to renal dysfunction is at least one of the factors that induce skeletal resistance to PTH.


Asunto(s)
Huesos/fisiología , Indicán/fisiología , Osteoblastos/fisiología , Hormona Paratiroidea/fisiología , Animales , Supervivencia Celular , Células Cultivadas , Femenino , Expresión Génica , Indicán/metabolismo , Ratones , Transportadores de Anión Orgánico/metabolismo , Osteoblastos/metabolismo , Estrés Oxidativo/fisiología , Embarazo
4.
Kidney Int Suppl ; (102): S34-6, 2006 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-16810309

RESUMEN

Abnormal bone turnover and mineral metabolism is observed in patients on dialysis. Secondary hyperparathyroidism (SHP) develops in response to mineral metabolism changes accompanying renal failure. As a factor of disease progression, the phenomenon of skeletal resistance to parathyroid hormone (PTH) is observed. With recent advances in the treatment of SHP, over-secretion of PTH can now be controlled. However, blood PTH levels 2 to 3 times higher than normal are considered necessary to maintain normal bone turnover in patients with renal failure. Various causes of skeletal resistance to PTH have been reported, including decrease in PTH receptor in osteoblasts, accumulation of 7-84 PTH fragment, and accumulation of osteoprotegerin. This skeletal resistance to PTH is not only a high-turnover bone accompanying SHP, but may also play a crucial role in the onset of low-turnover bone disease. We have produced a rat model of renal failure with normal level of PTH secretion and analyzed the bone of this model. Our results confirmed that bone turnover is lowered accompanying renal function impairment. We also found that this lowered bone turnover is improved by intermittent administration of PTH. In addition, PTH receptor gene expression is also decreased in low-turnover bone, as is observed in high-turnover bone disease. These findings confirm the presence of skeletal resistance to PTH in low-turnover bone accompanying renal failure. Control of calcium, phosphorus, and PTH levels with the target to maintain normal bone turnover is important in maintaining the quality of life of patients on dialysis.


Asunto(s)
Hormona Paratiroidea/sangre , Uremia/sangre , Animales , Resorción Ósea/sangre , Resorción Ósea/patología , Modelos Animales de Enfermedad , Humanos , Hiperparatiroidismo Secundario/sangre , Hiperparatiroidismo Secundario/etiología , Hiperparatiroidismo Secundario/patología , Osteoblastos/metabolismo , Osteoblastos/patología , Ratas , Insuficiencia Renal/sangre , Insuficiencia Renal/complicaciones , Uremia/complicaciones , Uremia/patología
7.
Bone Marrow Transplant ; 34(3): 267-9, 2004 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-15170164

RESUMEN

A 37-year-old Japanese man with systemic hemochromatosis due to multiple transfusions was referred to us for the treatment of severe aplastic anemia (SAA), from which he had been suffering for 24 years. The patient had diabetes arising from the hemochromatosis, chronic anal fissures, and a kidney abscess due to neutropenia. He was treated with a nonmyeloablative preconditioning regimen followed by non-T-cell-depleted (non-TCD) allogeneic peripheral blood stem cell transplantation (PBSCT) from his human leukocyte antigen (HLA)-haploidentical 2-loci-mismatched sibling. Prompt engraftment of granulocytes and platelets was observed, and graft-versus-host disease was easy to control. Noninherited maternal antigens in the donor were confirmed prior to PBSCT, and they were also detected in small quantities in the recipient. This report describes the first successful nonmyeloablative hematopoietic stem cell transplant in a heavily transfused SAA patient from an HLA-haploidentical 2-loci-mismatched sibling donor. The result suggests that a long-term fetomaternal microchimerism-positive sibling can be a second-line donor if an alternative HLA-identical donor is not available.


Asunto(s)
Anemia Aplásica/terapia , Depleción Linfocítica , Trasplante de Células Madre , Linfocitos T/inmunología , Adulto , Anemia Aplásica/complicaciones , Anemia Aplásica/inmunología , Transfusión Sanguínea , Haploidia , Prueba de Histocompatibilidad , Humanos , Masculino , Hermanos , Trasplante Homólogo/inmunología , Resultado del Tratamiento
8.
J Hum Hypertens ; 18(7): 475-85, 2004 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-14749712

RESUMEN

In order to establish the methodology of a population strategy for improving cardiovascular risk factors, we have planned the High-risk and Population Strategy for Occupational Health Promotion Study (HIPOP-OHP study). This study is a nonrandomized control trial in approximately 6500 participants in six intervention and six control companies. Our population strategy is based on three factors, nutrition, physical activity, and smoking. For each factor, a researcher's working team was organized and has been supporting the intervention. A standardized method to obtain comparable data has also been established. In the baseline survey, urinary sodium excretion in male subjects was higher, and urinary potassium excretion was lower in both genders in the intervention group compared to the control group. The prevalence of hypertension for both genders was also higher in the intervention group. Male subjects in the intervention group had higher serum total cholesterol than controls, while high-density lipoprotein cholesterol was lower in both genders in the intervention group compared to the control group. These differences were reflected by our finding that the predicted relative risk of coronary heart disease for male subjects was significantly higher in the intervention group (relative risk, RR: 1.17; 95% confidence interval, 95% CI.: 1.09, 1.25) and significantly lower in the control group (RR: 0.93; 95% CI.: 0.89, 0.98) compared to a model Japanese population. Similar results were observed in the female subjects. Taken together, these findings indicate that it is possible to compare trends of predicted relative risk for coronary heart disease between two groups.


Asunto(s)
Enfermedades Cardiovasculares/etiología , Promoción de la Salud , Salud Laboral , Adulto , Consumo de Bebidas Alcohólicas , Colesterol/sangre , HDL-Colesterol/sangre , Intervalos de Confianza , Ejercicio Físico , Femenino , Promoción de la Salud/métodos , Humanos , Hipertensión/epidemiología , Japón , Masculino , Persona de Mediana Edad , Fenómenos Fisiológicos de la Nutrición , Educación del Paciente como Asunto , Potasio/orina , Prevalencia , Riesgo , Caracteres Sexuales , Fumar , Sodio/orina
9.
J Endocrinol ; 171(2): 249-57, 2001 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-11691644

RESUMEN

In patients with humoral hypercalcemia of malignancy (HHM), serum levels of 1,25-dihydroxyvitamin D (1,25(OH)(2)D) are generally low, although the pathophysiology of the impaired vitamin D metabolism is not fully understood. In the present study, we have investigated vitamin D metabolism in our newly developed rat model of HHM in which a human infantile fibrosarcoma producing parathyroid hormone-related protein (PTHrP), named OMC-1, was inoculated s.c. into athymic nude rats. In OMC-1-bearing rats, the serum concentration of 1,25(OH)(2)D was markedly reduced when the animals exhibited severe hypercalcemia (Ca > or =15 mg/dl), while it was rather elevated in those with mild hypercalcemia. To further examine whether serum Ca levels affect 1,25(OH)(2)D concentration, we administered bisphosphonate YM529 to OMC-1-bearing rats when they exhibited severe hypercalcemia. The restoration of the serum Ca level by administration of YM529 was accompanied by a marked increase in the 1,25(OH)(2)D level, suggesting that the serum Ca level itself plays an important role in the regulation of the 1,25(OH)(2)D level in these rats. On the other hand, when the OMC-1-bearing rats were treated with a neutralizing antibody against PTHrP, serum 1,25(OH)(2)D levels remained low despite the reduction in serum Ca levels. Expression of 25-hydroxyvitamin D-1 alpha-hydroxylase (1 alpha-hydroxylase) in kidney was decreased in OMC-1-bearing rats with severe hypercalcemia, and markedly enhanced after treatment with bisphosphonate. This enhancement in 1 alpha-hydroxylase expression was not observed after treatment with the antibody against PTHrP. These results suggest that PTHrP was responsible for the enhanced expression of 1 alpha-hydroxylase in YM529-treated rats, and that hypercalcemia played a role in reducing the serum 1,25(OH)(2)D level in OMC-1-bearing rats by suppressing the PTHrP-induced expression of the 1 alpha-hydroxylase gene.


Asunto(s)
25-Hidroxivitamina D3 1-alfa-Hidroxilasa/metabolismo , Calcitriol/sangre , Calcio/sangre , Fibrosarcoma/complicaciones , Hipercalcemia/etiología , Proteínas/metabolismo , 24,25-Dihidroxivitamina D 3/sangre , 25-Hidroxivitamina D3 1-alfa-Hidroxilasa/genética , Animales , Anticuerpos Monoclonales/farmacología , Northern Blotting/métodos , Peso Corporal , Calcifediol/sangre , Bloqueadores de los Canales de Calcio/farmacología , Difosfonatos/farmacología , Fibrosarcoma/metabolismo , Expresión Génica , Humanos , Hipercalcemia/metabolismo , Imidazoles/farmacología , Riñón/enzimología , Masculino , Modelos Animales , Trasplante de Neoplasias , Proteína Relacionada con la Hormona Paratiroidea , Proteínas/inmunología , Ratas , Ratas Desnudas , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa
10.
Environ Health Perspect ; 109(8): 795-9, 2001 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-11564614

RESUMEN

We investigated the function of Clara cells in vivo during exposure to inhaled crystalline silica by examining pulmonary matrix metalloproteinase (MMP)-2 and MMP-9 mRNA levels in mice. The Clara cells of male FVB/n mice (8-12 weeks old) were ablated by intraperitoneal administration of naphthalene (300 mg/kg) in a corn oil vehicle. The mice were then exposed to crystalline silica (Min-U-Sil-5 silica, 97.1 +/- 9.5 mg/m(2), 6 hr/day, 5 days/week) for up to 2 weeks. Transcriptional levels of mRNA extracted from the lungs were assessed by reverse transcription-polymerase chain reaction. Gene expression of both MMP-2 and MMP-9 was significantly more marked in the Clara cell-ablated group than in the group with Clara cells, indicating that Clara cells inhibit MMP expression. Our findings suggest that Clara cells inhibit pulmonary inflammation induced by crystalline silica via MMPs in vivo.


Asunto(s)
Bronquios/ultraestructura , Células Epiteliales/enzimología , Metaloproteinasa 2 de la Matriz/genética , Metaloproteinasa 9 de la Matriz/genética , Fibrosis Pulmonar/inducido químicamente , Fibrosis Pulmonar/enzimología , Dióxido de Silicio/toxicidad , Animales , Bronquios/enzimología , Cristalización , Modelos Animales de Enfermedad , Células Epiteliales/efectos de los fármacos , Fibrosis , Expresión Génica , Inmunohistoquímica , Inflamación/enzimología , Inflamación/patología , Exposición por Inhalación , Pulmón/enzimología , Pulmón/patología , Masculino , Metaloproteinasa 2 de la Matriz/metabolismo , Metaloproteinasa 9 de la Matriz/metabolismo , Ratones , Ratones Endogámicos AKR , Naftalenos/toxicidad , Fibrosis Pulmonar/patología , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa
11.
Histopathology ; 39(2): 163-71, 2001 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-11493333

RESUMEN

AIMS: Pyothorax-associated lymphoma (PAL) develops in the pleural cavity of patients with a long history of pyothorax. Epstein-Barr virus (EBV) is also involved in PAL, similar to lymphomas in immunodeficient patients. Here we examined T-lymphocyte subsets as well as c-myc and REL gene amplification in PAL tissues. METHODS AND RESULTS: We determined the number and distribution of CD4+ and CD8+ T-lymphocytes, to evaluate T-cells in the host immune reaction in seven cases of PAL. As controls, we also studied 10 cases of extranodal diffuse large B-cell lymphoma (DLBL) and 10 cases of nodal DLBL. Chromosomal imbalances in PAL were determined by using comparative genomic hybridization (CGH) analysis. The mean numbers of CD4+ and CD8+ and their ratio were significantly lower in PAL than in nodal DLBL. CGH analysis of PAL showed amplification of the 8q24 chromosomal region. In addition, c-myc amplification was found in four cases of PAL by Southern blot analysis. CONCLUSIONS: Our results suggest that the development of PAL may involve a local immunosuppressive environment and that amplification of c-myc might promote tumour progression, as has been described in the development of Burkitt's lymphoma.


Asunto(s)
Empiema Pleural/complicaciones , Genes myc/genética , Terapia de Inmunosupresión , Linfoma/patología , Anciano , Southern Blotting , Relación CD4-CD8 , Linfocitos T CD4-Positivos/citología , Linfocitos T CD8-positivos/citología , Aberraciones Cromosómicas/genética , ADN/genética , Infecciones por Virus de Epstein-Barr/patología , Infecciones por Virus de Epstein-Barr/virología , Femenino , Amplificación de Genes , Herpesvirus Humano 4/genética , Humanos , Inmunofenotipificación , Hibridación in Situ , Recuento de Linfocitos , Linfoma/etiología , Linfoma/genética , Masculino , Persona de Mediana Edad , Estadificación de Neoplasias , Hibridación de Ácido Nucleico
12.
J Bone Miner Metab ; 19(4): 207-12, 2001.
Artículo en Inglés | MEDLINE | ID: mdl-11448012

RESUMEN

Parathyroid hormone (PTH) increases serum calcium (Ca) by enhancing bone resorption and renal Ca reabsorption. However, detailed mechanisms of enhanced bone resorption by PTH remain to be elucidated. Although PTH has been shown to increase the expression level of osteoblastic matrix metalloproteinase (MMP)-13 in vitro, only limited results are available regarding the in vivo regulation of MMP expression. In the present study, we have examined expression levels of MMPs in PTH-infused rats. Infusion of 1.5 or 2.0 nmol/kg/day rat PTH(1-34) for 3 days resulted in a dose-dependent increase in serum Ca. PTH infusion also decreased serum phosphate levels and increased urinary excretion of Ca and phosphate. Infusion of PTH for 7 days resulted in less severe hypercalcemia and hypophosphatemia. Urinary Ca and phosphate excretion in rats infused for 7 days was less than that in rats infused for 3 days. Northern blot analysis showed that PTH infusion increased the expression level of MMP-13 in calvaria, although it did not affect MMP-2 expression. Furthermore, the time-course and severity of hypercalcemia and hypercalciuria correlated with the expression level of MMP-13. In situ hybridization also showed that PTH infusion increased the expression level of MMP-13 in femora. These results indicate that PTH enhances MMP-13 expression in vivo and suggest that PTH stimulates bone resorption at least partly by enhancing MMP-13 expression.


Asunto(s)
Colagenasas/genética , Colagenasas/metabolismo , Hormona Paratiroidea/farmacología , Animales , Secuencia de Bases , Resorción Ósea/inducido químicamente , Resorción Ósea/enzimología , Resorción Ósea/genética , Huesos/efectos de los fármacos , Huesos/enzimología , Calcio/sangre , Calcio/orina , ADN Complementario/genética , Expresión Génica/efectos de los fármacos , Hibridación in Situ , Masculino , Metaloproteinasa 13 de la Matriz , Metaloproteinasa 2 de la Matriz/genética , Metaloproteinasa 2 de la Matriz/metabolismo , Hormona Paratiroidea/administración & dosificación , Fosfatos/sangre , Fosfatos/orina , ARN Mensajero/genética , ARN Mensajero/metabolismo , Ratas , Ratas Wistar
13.
Inhal Toxicol ; 13(7): 589-601, 2001 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-11452356

RESUMEN

To investigate whether the results of intratracheal instillation studies on mineral fibers reflect the findings obtained by long-term inhalation data on mineral fibers, we have examined gene expression of cytokines and pathological features in lungs induced by intratracheal instillation and inhalation of mineral fibers. Male Wistar rats were given a single intratracheal instillation of 2 mg alumina silicate refractory fiber (RF1) or potassium octatitanate whisker (PT1), and were sacrificed 4 wk after the fiber instillation. Long-term inhalation studies were also performed. In these, animals were exposed to fiber aerosol of RF1 or PT1 for 5 days/wk for 1 yr, and sacrificed after 1 yr of inhalation. Expression of tumor necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6), and transforming growth factor-beta1 (TGF-beta1) from lungs was observed by reverse-transcription polymerase chain reaction (RT-PCR). The expression of TNF-alpha, IL-6, and TGF-beta1 mRNA in PT1-exposed lung was significantly higher than for those exposed to RF1 in both intratracheal instillation and inhalation studies. Pathological findings revealed that mild pulmonary fibrosis was seen in the lungs after intratracheal instillation and inhalation of PT1 but not RF1. Similarities were observed not only in gene expression of cytokines but in pathological features between both studies. These data suggested that the results of intratracheal instillation reflect the findings obtained from long-term inhalation data.


Asunto(s)
Citocinas/genética , Pulmón/metabolismo , Fibras Minerales/toxicidad , Fibrosis Pulmonar/metabolismo , ARN Mensajero/metabolismo , Silicatos de Aluminio/toxicidad , Animales , Citocinas/biosíntesis , Cartilla de ADN/química , Expresión Génica , Interleucina-6/biosíntesis , Interleucina-6/genética , Intubación Intratraqueal , Pulmón/efectos de los fármacos , Pulmón/patología , Masculino , Fibrosis Pulmonar/inducido químicamente , Ratas , Ratas Wistar , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Titanio/toxicidad , Factor de Crecimiento Transformador beta/biosíntesis , Factor de Crecimiento Transformador beta/genética , Factor de Crecimiento Transformador beta1 , Factor de Necrosis Tumoral alfa/biosíntesis , Factor de Necrosis Tumoral alfa/genética
14.
Neuroreport ; 12(6): 1123-6, 2001 May 08.
Artículo en Inglés | MEDLINE | ID: mdl-11338177

RESUMEN

We investigated the effect of fluoxetine, a selective serotonin reuptake inhibitor (SSRI), on L-DOPA-derived extracellular dopamine (DA) levels in the striatum of rats with nigrostriatal dopaminergic denervation using in vivo microdialysis. Treatment with fluoxetine (10 mg/kg, i.p.) induced a 41% reduction in the cumulative amount of extracellular DA during 300 min following L-DOPA administration (50 mg/kg, i.p.; p < 0.01). This effect was antagonized by pretreatment with WAY-100635, a potent 5-HT1A antagonist, indicating that this effect of fluoxetine is due to its indirect 5-HT1A agonistic property. These results suggest that SSRIs may impair motor functions in patients with Parkinson's disease by reducing efflux of exogenous L-DOPA-derived DA.


Asunto(s)
Cuerpo Estriado/metabolismo , Dihidroxifenilalanina/análogos & derivados , Dopaminérgicos/uso terapéutico , Dopamina/metabolismo , Fluoxetina/administración & dosificación , Levodopa/antagonistas & inhibidores , Inhibidores Selectivos de la Recaptación de Serotonina/administración & dosificación , Adrenérgicos/toxicidad , Animales , Cuerpo Estriado/efectos de los fármacos , Dihidroxifenilalanina/toxicidad , Espacio Extracelular/metabolismo , Levodopa/uso terapéutico , Masculino , Enfermedad de Parkinson/tratamiento farmacológico , Enfermedad de Parkinson/metabolismo , Ratas , Ratas Wistar
15.
Ind Health ; 39(2): 114-8, 2001 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-11341540

RESUMEN

Biopersistence of man-made fibers by animal inhalation experiments was mainly reviewed. This report showed that the biopersistence and maximum tolerated dose are significantly important factors for hazard assessment for man-made fibers as well as fiber size (diameter/length), chemical compositions and surface properties.


Asunto(s)
Pulmón/metabolismo , Fibras Minerales/toxicidad , Administración por Inhalación , Animales , Citocinas/metabolismo , Pulmón/patología , Tamaño de la Partícula , Ratas , Ratas Wistar , Medición de Riesgo
16.
Ind Health ; 39(2): 175-82, 2001 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-11341548

RESUMEN

We studied the short-term effect of silicon carbide whisker (SiCW) in vivo by instillation and inhalation to the rat lung. SiCW was instilled low dose (2 mg/0.5 ml saline) or high dose (10 mg/ 0.5 ml) intratracheally into the lungs of 25 rats. SiCW was also inhaled to another 25 rats at the average concentration of 10.4 mg/m3 for 1 month. In instillation study, the lung had focal alveolitis with the destruction of alveolar wall especially at 3 days after the instillation, and the lesion remained as an aggregated foci of SiCW at 6 months. The 'inflammation-score' of the instilled group by point counting method of the specimen correspondingly decreased gradually. In inhalation group, a minimum inflammatory change was observed. Collagen deposition in the aggregated foci of SiCW with accumulated alveolar macrophages and neutrophils was not progressive during the observed period. These findings suggest that SiCW may cause a minor effect to the rat lung in 6 months after exposure.


Asunto(s)
Compuestos Inorgánicos de Carbono/toxicidad , Enfermedades Pulmonares/patología , Compuestos de Silicona/toxicidad , Administración por Inhalación , Análisis de Varianza , Animales , Compuestos Inorgánicos de Carbono/administración & dosificación , Inflamación , Inyecciones , Enfermedades Pulmonares/etiología , Masculino , Fibras Minerales/toxicidad , Ratas , Ratas Wistar , Compuestos de Silicona/administración & dosificación
17.
J Neurochem ; 76(5): 1346-53, 2001 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-11238719

RESUMEN

In order to determine whether L-DOPA-derived extracellular dopamine (DA) in the striatum with dopaminergic denervation is affected by activation of serotonin autoreceptors (5-HT(1A) and 5-HT(1B) receptors), we applied in vivo brain microdialysis technique to 6-hydroxydopamine-lesioned rats and examined the effects of the selective 5-HT(1A) receptor agonist 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT) and the selective 5-HT(1B) receptor agonist CGS-12066 A on L-DOPA-derived extracellular DA levels. Single L-DOPA injection (50 mg/kg i.p.) caused a rapid increase and a following decrease of extracellular DA, with a peak value at 100 min after L-DOPA injection. Pretreatment with both 0.3 mg/kg and 1 mg/kg 8-OH-DPAT (i.p.) significantly attenuated an increase in L-DOPA-derived extracellular DA and the times of peak DA levels were prolonged to 150 min and 225 min after L-DOPA injection, respectively. These 8-OH-DPAT-induced changes in L-DOPA-derived extracellular DA were antagonized by further pretreatment with WAY-100635, a selective 5-HT(1A) antagonist. In contrast, intrastriatal perfusion with the 5-HT(1B) agonist CGS-12066 A (10 nM and 100 nM) did not induce any changes in L-DOPA-derived extracellular DA. Thus, stimulation of 5-HT(1A) but not 5-HT(1B) receptors attenuated an increase in extracellular DA derived from exogenous L-DOPA. These results support the hypothesis that serotonergic neurons are primarily responsible for the storage and release of DA derived from exogenous L-DOPA in the absence of dopaminergic neurons.


Asunto(s)
Cuerpo Estriado/fisiología , Dopamina/metabolismo , Levodopa/farmacología , Receptores de Serotonina/fisiología , Agonistas de Receptores de Serotonina/farmacología , Sustancia Negra/fisiología , Animales , Cuerpo Estriado/efectos de los fármacos , Desnervación , Espacio Extracelular/efectos de los fármacos , Espacio Extracelular/fisiología , Cinética , Masculino , Microdiálisis , Piperazinas/farmacología , Piridinas/farmacología , Ratas , Ratas Wistar , Receptor de Serotonina 5-HT1B , Receptores de Serotonina/efectos de los fármacos , Receptores de Serotonina 5-HT1
18.
J Bone Miner Res ; 16(2): 221-30, 2001 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-11204422

RESUMEN

The removal of unmineralized matrix from the bone surface is essential for the initiation of osteoclastic bone resorption because osteoclasts cannot attach to the unmineralized osteoid. Matrix metalloproteinases (MMPs) are known to digest bone matrix. We recently reported that among the MMPs expressed in mouse osteoblastic cells, MMP-13 (collagenase-3) was the one most predominantly up-regulated by bone resorbing factors including 1alpha,25-dihydroxyvitamin D3 [1alpha,25(OH)2D3]. In this study, we examined the mechanism of regulation of MMP-13 expression by 1alpha,25(OH)2D3 in mouse osteoblastic MC3T3-E1 cells. 1Alpha,25(OH)2D3 increased steady-state messenger RNA (mRNA) and protein levels of MMP-13. De novo protein synthesis was essential for the induction because cycloheximide (CHX) decreased the effect of 1alpha,25(OH)2D3 on the MMP-13 mRNA level. 1Alpha,25(OH)2D3 did not alter the decay of MMP-13 mRNA in transcriptionally arrested MC3T3-E1 cells; however, it increased the MMP-13 heterogeneous nuclear RNA (hnRNA) level and MMP-13 transcriptional rate. The binding activity of nuclear extracts to the AP-1 binding site, but not to the Cbfa1 binding site, in the MMP-13 promoter region was up-regulated by 1alpha,25(OH)2D3, suggesting the mediation of AP-1 in this transcriptional induction. To determine the contribution of MMPs to bone resorption by 1alpha,25(OH)2D3, the inhibitory effect of BB94, an MMP inhibitor, on resorbed pit formation by mouse crude osteoclastic cells was examined on either an uncoated or collagen-coated dentine slice. BB94 did not prevent resorbed pit formation on uncoated dentine whereas it did on collagen-coated dentine. We therefore propose that the transcriptional induction of MMP-13 in osteoblastic cells may contribute to the degradation of unmineralized matrix on the bone surface as an early step of bone resorption by 1alpha,25(OH)2D3.


Asunto(s)
Calcitriol/farmacología , Colagenasas/genética , Regulación de la Expresión Génica/efectos de los fármacos , Proteínas de Neoplasias , Transcripción Genética/efectos de los fármacos , Células 3T3 , Animales , Secuencia de Bases , Resorción Ósea , Núcleo Celular/metabolismo , Colagenasas/metabolismo , Subunidad alfa 1 del Factor de Unión al Sitio Principal , Cartilla de ADN , Metaloproteinasa 13 de la Matriz , Ratones , Regiones Promotoras Genéticas , ARN Mensajero/genética , Factor de Transcripción AP-1/metabolismo , Factores de Transcripción/metabolismo
19.
J Cell Physiol ; 185(2): 207-14, 2000 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-11025442

RESUMEN

In addition to their stimulating function on osteoclastic bone resorption, bone resorptive factors may regulate proteinases and related factors in osteoblastic cells to degrade bone matrix proteins. This study investigated the regulation of matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) by bone resorptive factors in the cultures of mouse osteoblastic MC3T3-E1 cells, mouse primary osteoblastic (POB) cells, and neonatal mouse calvariae. Expression of either MMP-2, -3, -9, -11, -13, and -14 or TIMP-1, -2, and -3 was detected in MC3T3-E1 cells and POB cells. When the bone resorptive factors parathyroid hormone, 1,25-dihydroxyvitamin D(3), prostaglandin E(2), interleukin-1beta (IL-1beta), and tumor necrosis factor-alpha (TNF-alpha) were added to the cell cultures, MMP-13 mRNA levels were found predominantly to increase by all resorptive factors in the three cultures. mRNA levels of either MMP-3 and -9 or TIMP-1 and -3 were found to increase mainly by the cytokines IL-1beta and TNF-alpha. BB94, a nonselective MMP inhibitor, neutralized the (45)Ca release stimulated by these resorptive factors to an extent similar to that of calcitonin, strongly suggesting that bone resorptive factors function at least partly through MMP formation. We propose that MMP-13 mRNA expression in osteoblastic cells may play an important role in stimulating matrix degradation by both systemic and local resorptive factors, whereas either MMP-3 and -9 or TIMP-1 and -3 might modulate matrix degradation by local cytokines only.


Asunto(s)
Citocinas/fisiología , Metaloproteinasas de la Matriz/metabolismo , Osteoblastos/fisiología , Fenilalanina/análogos & derivados , Inhibidores Tisulares de Metaloproteinasas/metabolismo , Animales , Animales Recién Nacidos/metabolismo , Resorción Ósea/fisiopatología , Proteínas Portadoras/farmacología , Línea Celular , Gelatinasas/metabolismo , Hormonas/farmacología , Inhibidores de la Metaloproteinasa de la Matriz , Glicoproteínas de Membrana/farmacología , Ratones , Ratones Endogámicos , Osteoblastos/metabolismo , Fenilalanina/farmacología , Ligando RANK , Receptor Activador del Factor Nuclear kappa-B , Cráneo/efectos de los fármacos , Cráneo/metabolismo , Tiofenos/farmacología
20.
Sangyo Eiseigaku Zasshi ; 42(1): 1-5, 2000 Jan.
Artículo en Japonés | MEDLINE | ID: mdl-10707378

RESUMEN

We installed an effective, practical and low-cost smoking corner in an office to protect against passive smoking. The smoking corner was separated from the non-smoking area with transparent, nonflammable screens. Four exhaust fans were installed in the smoking corner so that there was no leakage of environmental tobacco smoke. The required exhaust air rate in the smoking corner was pre-calculated from the volume of the smoking corner and the rate of consumption of cigarettes. The suspended airborne particle concentration definitely decreased in the non-smoking area after installation of the smoking corner. The result of a questionnaire survey also revealed the improvement in the air quality in this office.


Asunto(s)
Ambiente Controlado , Salud Laboral , Contaminación por Humo de Tabaco/prevención & control , Lugar de Trabajo , Contaminantes Ocupacionales del Aire/análisis , Femenino , Humanos , Masculino , Tamaño de la Partícula , Fumar/efectos adversos , Encuestas y Cuestionarios
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA