Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 32
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
J Comp Pathol ; 177: 10-17, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32505236

RESUMO

In human amyloidoses, amyloid signature proteins (ASPs), such as serum amyloid P component (SAP) and apolipoprotein E (ApoE), are deposited in tissues together with amyloid fibrils and are implicated in the pathogenesis of amyloidosis. Few reports describe ASPs in animals. In this study, we examined feline amyloidosis and performed immunohistochemical and proteomic analyses of SAP, ApoE, apolipoprotein A-I (ApoAI) and apolipoprotein A-IV (ApoAIV). Ten cases of systemic amyloidosis, three cases of amyloid-producing odontogenic tumour and three cases of islet amyloidosis were used for immunohistochemistry (IHC) and/or proteomic analyses. IHC showed that ApoE was present in amyloid deposits in all samples. ApoAI and ApoAIV differed in the degree of co-deposition with amyloid depending on the type of amyloid and the affected organ. SAP was negative in all amyloid deposits. Proteomic analysis showed that ApoE was present in all samples, but ApoAI and ApoAIV were detected only in some samples and SAP was not detected in any samples. The observation that ApoE was detected in all types of amyloid suggests the involvement of ApoE in the development of feline amyloidosis. ASPs in feline amyloidosis are significantly different from those in human amyloidosis, suggesting that the involvement of ASPs in the pathological condition differs between animal species.


Assuntos
Amiloidose/veterinária , Doenças do Gato , Amiloide/metabolismo , Amiloidose/patologia , Animais , Apolipoproteína A-I/metabolismo , Apolipoproteínas A/metabolismo , Apolipoproteínas E/metabolismo , Gatos , Imuno-Histoquímica/veterinária , Placa Amiloide/veterinária , Proteômica
2.
Genes Brain Behav ; 18(2): e12481, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-29665250

RESUMO

Individuals use coping behaviors to deal with unpleasant daily events. Such behaviors can moderate or mediate the pathway between psychosocial stress and health-related outcomes. However, few studies have examined the associations between coping behaviors and genetic variants. We conducted a genome-wide association study (GWAS) on coping behaviors in 14088 participants aged 35 to 69 years as part of the Japan Multi-Institutional Collaborative Cohort Study. Five coping behaviors (emotional expression, emotional support seeking, positive reappraisal, problem solving and disengagement) were measured and analyzed. A GWAS analysis was performed using a mixed linear model adjusted for study area, age and sex. Variants with suggestive significance in the discovery phase (N = 6403) were further examined in the replication phase (N = 7685). We then combined variant-level association evidence into gene-level evidence using a gene-based analysis. The results showed a significant genetic contribution to emotional expression and disengagement, with an estimation that the 19.5% and 6.6% variance in the liability-scale was explained by common variants. In the discovery phase, 12 variants met suggestive significance (P < 1 × 10-6 ) for association with the coping behaviors and perceived stress. However, none of these associations were confirmed in the replication stage. In gene-based analysis, FBXO45, a gene with regulatory roles in synapse maturation, was significantly associated with emotional expression after multiple corrections (P < 3.1 × 10-6 ). In conclusion, our results showed the existence of up to 20% genetic contribution to coping behaviors. Moreover, our gene-based analysis using GWAS data suggests that genetic variations in FBXO45 are associated with emotional expression.


Assuntos
Adaptação Psicológica , Emoções Manifestas , Proteínas F-Box/genética , Polimorfismo Genético , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
3.
J Natl Cancer Inst ; 64(5): 1105-12, 1980 May.
Artigo em Inglês | MEDLINE | ID: mdl-6767873

RESUMO

Effects of neonatal androgenization on 7,12-dimethylbenz[a]anthracene (DMBA)-induced mammary tumorigenesis infemale noninbred Sprague-Dawley rats are reported. Testosterone propionate (1.25 mg) was injected sc into 29 2-day-old rats. At 50 days of age, all rats were given 20 mg of DMBA through a stomach tube. In these androgenized rats, no corpora lutea were found in the ovaries and the induction of mammary carcinoma by DMBA was strongly suppressed, whereas the induction of mammary dysplasia was significantly accelerated in comparison with the neonatally intact controls. Mammary dysplasia in the androgenized group varied widely, with two kinds of macroscopically detectable tumor-forming lesions (solid and cystic) and with microscopic characteristics of acinar adenosis, fibrotic adenosis, fibrosis, intraductal papillary proliferative lesions, and epithelial cysts. The earliest lesions of mammary dysplasia observed were acinar adenosis nodules and microcysts, both of which appeared as multifocal phenomena as early as 25 days after administration of DMBA.


Assuntos
9,10-Dimetil-1,2-benzantraceno/toxicidade , Benzo(a)Antracenos/toxicidade , Modelos Animais de Doenças , Neoplasias Mamárias Experimentais/induzido quimicamente , Lesões Pré-Cancerosas/induzido quimicamente , Testosterona/farmacologia , 9,10-Dimetil-1,2-benzantraceno/administração & dosagem , Glândulas Suprarrenais/efeitos dos fármacos , Animais , Animais Recém-Nascidos , Peso Corporal/efeitos dos fármacos , Feminino , Intubação , Neoplasias Mamárias Experimentais/patologia , Tamanho do Órgão/efeitos dos fármacos , Ovário/efeitos dos fármacos , Hipófise/efeitos dos fármacos , Lesões Pré-Cancerosas/patologia , Ratos , Fatores de Tempo
4.
J Natl Cancer Inst ; 74(6): 1275-81, 1985 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-2987594

RESUMO

Comprehensive studies of carcinogenesis in newborn or preweanling SD rats were conducted under various dose schedules of cycasin (CAS: 14901-08-7) administration. When cycasin was given sc to newborn rats at day 0, tumors were detected in more than 80% of rats of both sexes; kidney tumors were by far the most common. The incidences of tumors declined in the older groups, namely, over 60% in both sexes in the 7-day group, 55% in males and 8.3% in females in 14-day rats, and 0% in 21-day groups. By multiple administration, tumor incidences elevated considerably. Administration ip of cycasin also gave rise to tumor induction in newborn rats. A total of 435 kidney tumors found in the experiments were studied pathologically. Most of them were classified as mesenchymal tumor; some of them metastasized. A few other tumors were found in the liver and colon.


Assuntos
Compostos Azo , Cicasina , Neoplasias Experimentais/induzido quimicamente , Adenocarcinoma/induzido quimicamente , Adenocarcinoma/patologia , Animais , Animais Recém-Nascidos , Animais Lactentes , Carcinoma Hepatocelular/induzido quimicamente , Carcinoma Hepatocelular/patologia , Neoplasias do Colo/induzido quimicamente , Neoplasias do Colo/patologia , Feminino , Neoplasias Renais/induzido quimicamente , Neoplasias Renais/patologia , Neoplasias Hepáticas/induzido quimicamente , Neoplasias Hepáticas/patologia , Masculino , Mesenquimoma/induzido quimicamente , Mesenquimoma/patologia , Neoplasias Experimentais/patologia , Ratos , Ratos Endogâmicos
5.
Diabetol Int ; 7(3): 252-258, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30603271

RESUMO

BACKGROUND: The utility of casual serum triglyceride (TG) as a predictor of type 2 diabetes mellitus (DM) is unclear, especially during the most productive years. METHODS: Participants were 3271 workers (913 men and 2358 women, age 20-57) without DM at baseline. They underwent consecutive annual medical check-ups for 8 years. The association between newly diagnosed DM and casual serum TG level was determined by classifying the participants into 4 groups according to casual serum TG level at baseline: below 50 mg/dL (group A), 50-100 mg/dL (group B), 100-150 mg/dL (group C), and ≥150 mg/dL (group D). The effects of casual serum TG level in combination with sex, obesity, or serum glucose level on newly diagnosed DM were also evaluated. RESULTS: A total of 222 newly diagnosed type 2 DM cases with a mean age of 50 years old were observed during the follow-up period, i.e., 10/406 in group A, 66/1534 in group B, 58/712 in group C, and 88/619 in group D. Compared with group A, the odds ratio (ORs) for newly diagnosed DM (after adjusting for DM-associated factors) was found to increase with casual serum TG level: 1.38 (group B), 1.79 (group C), and 2.36 (group D). Moreover, the OR for newly diagnosed DM was higher in participants with high casual serum TG levels who were also male (OR 2.46), obese (OR 4.18), or had a high serum glucose level (OR 6.96) than in the reference group. CONCLUSIONS: Serum TG level ≥150 mg/dL when fasting or nonfasting is a significant predictor of type 2 diabetes in middle-aged Japanese workers.

6.
J Nutr Health Aging ; 19(7): 719-28, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26193854

RESUMO

BACKGROUND/OBJECTIVES: Serum polyunsaturated fatty acid (PUFA) composition reflects dietary intake and is related to risks for cardiovascular diseases. We hypothesized that serum n-3 PUFA composition, especially including long-chain n-3 PUFA such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), is associated with inflammatory status, which is related to increased risk for cardiovascular diseases. SUBJECTS/METHODS: We investigated the relationship between serum PUFA composition and high-sensitivity C-reactive protein (hs-CRP) levels in a cross-sectional study among 1,102 healthy men and women aged 40-74 years who reside in Kobe City. Multiple linear regression models that predict hs-CRP level were prepared to confirm the contribution of serum total n-3 PUFA, long-chain n-3 PUFA, EPA and DHA compositions after adjusting for other PUFAs and atherosclerotic risk factors. RESULTS: The serum n-3 PUFA, particularly long-chain n-3 PUFA, compositions were inversely associated with the hs-CRP levels. The standardized regression coefficient was -0.089 (p < 0.01) for total n-3 PUFA, -0.091 (p < 0.01) for long-chain n-3 PUFA, -0.071 (p = 0.03) for EPA, and -0.068 (p = 0.04) for DHA. The n-6 PUFA compositions were also inversely associated with the hs-CRP levels (-0.169 [p < 0.01] for total n-6 PUFA and -0.159 [p < 0.01] for linoleic acid). CONCLUSIONS: The serum n-3 PUFA compositions were inversely related with the hs-CRP levels, similar associations were also observed in n-6 PUFA compositions. Our results suggest that dietary PUFA intake was inversely associated with attenuated inflammation in healthy Japanese population.


Assuntos
Povo Asiático , Proteína C-Reativa/análise , Ácidos Graxos Ômega-3/sangue , Ácidos Graxos Ômega-6/sangue , Saúde , Adulto , Idoso , Doenças Cardiovasculares/sangue , Cidades , Estudos Transversais , Dieta , Ácidos Docosa-Hexaenoicos/sangue , Ácido Eicosapentaenoico/sangue , Ácidos Graxos Ômega-3/química , Feminino , Inquéritos Epidemiológicos , Humanos , Inflamação/sangue , Japão , Masculino , Pessoa de Meia-Idade , Fatores de Risco
7.
Int J Oncol ; 15(6): 1081-9, 1999 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-10568812

RESUMO

Changes in cell membrane carbohydrate antigens play an important role in metastatic potential associated with carcinogenesis and in prognostic factors. We investigated immunohistochemically the expression of CD15 and sialyl CD15 (sCD15) in lung cancer tissue by using Leu-M1 antibody and MXKM-93 antibody, respectively, and then assessed the relationship between their expression and the patient outcome. Lung cancer tissue expression of CD15 was significantly higher in adenocarcinoma (55.9%) and squamous cell carcinoma (44.7%) than in small cell carcinoma (10%) (p=0.01, p=0.006). Expression of sCD15 was significantly higher in adenocarcinoma (52.9%) than in squamous cell carcinoma (10.5%) or small cell carcinoma (10%) (p<0. 0001, p=0.016). No association was found between CD15 expression and clinical stage, but sCD15 expression increased with clinical stage (stage I+II vs. III+IV: 16.7% vs. 39.6%; p=0.049). Expression of CD15 (1.5%) was significantly lower than expression of sCD15 (12.3%) in normal surrounding tissue. Examination of associations with outcome in NSCLC revealed that expression of sCD15 in resected cases, and expression of CD15 in non-resected cases were significantly correlated with shortening of median survival time (p<0.05). When associations with prognostic factors were assessed by univariate analysis, expression of sCD15 was found to be correlated with distant metastasis, and expression of CD15 with decrease in performance status (PS). In the multivariate analysis by the Cox proportional hazard model, sCD15 and CD15 negativity contributed to longer survival time after PS and clinical stage. The results of a combination assay of CD15 and sCD15 showed that expression of both carbohydrate antigens significantly shortened survival time in both the resected and non-resected group (log-rank test, p<0.05). This combination assay also appeared to be extremely useful in predicting the outcome in all clinical stages of NSCLC.


Assuntos
Antígenos Glicosídicos Associados a Tumores/biossíntese , Carcinoma Pulmonar de Células não Pequenas/metabolismo , Antígenos CD15/biossíntese , Neoplasias Pulmonares/metabolismo , Adenocarcinoma/metabolismo , Adenocarcinoma/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Antígenos Glicosídicos Associados a Tumores/análise , Carcinoma Pulmonar de Células não Pequenas/patologia , Carcinoma de Células Pequenas/metabolismo , Carcinoma de Células Pequenas/patologia , Carcinoma de Células Escamosas/metabolismo , Carcinoma de Células Escamosas/patologia , Progressão da Doença , Feminino , Humanos , Imuno-Histoquímica , Antígenos CD15/análise , Neoplasias Pulmonares/patologia , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Oligossacarídeos/sangue , Prognóstico , Coelhos , Fatores de Risco , Antígeno Sialil Lewis X , Análise de Sobrevida
8.
Oncol Rep ; 7(2): 305-10, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-10671676

RESUMO

We conducted a randomized trial of dose-intensive weekly alternating chemotherapy (CAV/PE-W) and standard alternating chemotherapy (CAV/PE) in small cell lung cancer (SCLC) patients with good prognostic factors. A total of 76 patients with SCLC was randomized. The CAV/PE-W consisted of 4 alternating cycles of cyclophosphamide: 500 mg/m2, doxorubicin: 30 mg/m2, and vincristine: 1 mg/m2 (day 1) and cisplatin: 50 mg/m2 (day 8) and etoposide: 75 mg/m2 (days 8 and 9). The CAV/PE consisted of 2 alternating cycles of cyclophosphamide: 800 mg/m2, doxorubicin: 50 mg/m2, and vincristine: 1.4 mg/m2 (day 1), cisplatin: 100 mg/m2 (day 22) and etoposide: 100 mg/m2 (days 22, 23 and 24). Eligibility criteria were no prior therapy, no active concomitant malignancy, ECOG PS of 0 or 1, age < or =75, adequate hematologic functions and no brain metastasis. The complete response (CR) rate for CAV/PE-W (14/38, 36.8%) was significantly higher than that for CAV/PE (6/38, 15.8%, chi2; p=0. 032). However, the response rate in patients on CAV/PE-W (36/38, 94. 7%) was not significantly higher than the rate for CAV/PE (31/38, 81. 6%, chi2; p=0.076). Progression-free survival for patients on CAV/PE-W was significantly longer than that of patients on CAV/PE (41.4 weeks vs. 21.3 weeks, log-rank; p=0.0007, generalized Wilcoxon; p=0.0034) as was overall median survival (67.0 weeks vs. 51.2 weeks, log-rank; p=0.028). Actual dose-intensity of CAV/PE-W was 1.74 times that of CAV/PE. Hematological toxicities were equally frequent and G-CSF contributes to treatment efficacy by allowing administration of dose-intensive chemotherapy. The CAV/PE-W achieved a higher CR rate and longer survival, than the CAV/PE.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Carcinoma de Células Pequenas/tratamento farmacológico , Neoplasias Pulmonares/tratamento farmacológico , Adulto , Idoso , Carcinoma de Células Pequenas/patologia , Carcinoma de Células Pequenas/fisiopatologia , Cisplatino/administração & dosagem , Ciclofosfamida/administração & dosagem , Relação Dose-Resposta a Droga , Doxorrubicina/administração & dosagem , Etoposídeo/administração & dosagem , Feminino , Humanos , Neoplasias Pulmonares/patologia , Neoplasias Pulmonares/fisiopatologia , Masculino , Pessoa de Meia-Idade , Análise de Sobrevida , Vincristina/administração & dosagem
9.
J Hum Hypertens ; 28(5): 323-7, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24172293

RESUMO

Brachial-ankle pulse wave velocity (baPWV) is a non-invasive measure of arterial stiffness obtained using an automated system. Although baPWVs have been widely used as a non-invasive marker for evaluation of arterial stiffness, evidence for the prognostic value of baPWV in the general population is scarce. In this study, we assessed the association between baPWV and future cardiovascular disease (CVD) incidence in a Japanese population. From 2002 to 2009, baPWV was measured in a total of 4164 men and women without a history of CVD, and they were followed up until the end of 2009 with a median follow-up period of 6.5 years. Hazard ratios (HRs) for CVD incidence according to baPWV levels were calculated using a Cox proportional hazards model adjusted for potential confounding factors, including seated or supine blood pressure (BP). During the follow-up period, we observed 40 incident cases of CVD. In multivariable-adjusted model, baPWV as a continuous variable was not significantly associated with future CVD risk after adjustment for supine BP. However, compared with lower baPWV category (<18 m s(-1)), higher baPWV (< or = 18.0 m s(-1)) was significantly associated with an increased CVD risk (HR: 2.70, 95% confidence interval: 1.18-6.19). Higher baPWV (< or = 18.0 m s(-1)) would be an independent predictor of future CVD event in the general Japanese population.


Assuntos
Índice Tornozelo-Braço , Povo Asiático/estatística & dados numéricos , Velocidade do Fluxo Sanguíneo/fisiologia , Hipertensão/etnologia , Hipertensão/fisiopatologia , Fluxo Pulsátil/fisiologia , Adulto , Idoso , Fatores de Confusão Epidemiológicos , Feminino , Seguimentos , Humanos , Incidência , Japão/epidemiologia , Masculino , Pessoa de Meia-Idade , Prognóstico , Fatores de Risco , Acidente Vascular Cerebral/etnologia , Acidente Vascular Cerebral/fisiopatologia , Rigidez Vascular/fisiologia
10.
Eur J Clin Nutr ; 66(3): 329-35, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21897424

RESUMO

BACKGROUND/OBJECTIVES: Numerous studies reported beneficial effects of marine n-3 fatty acids (n-3 FAs) on cardiovascular disease (CVD) and its risk factors. However, the association of marine n-3 FAs with plasma fibrinogen, a risk factor for CVD, remains uncertain. SUBJECTS/METHODS: In a population-based, cross-sectional study of 795 men aged 40-49 without CVD (262 whites in Allegheny County, Pennsylvania, USA, 302 Japanese in Kusatsu, Japan and 229 Japanese Americans in Honolulu, Hawaii, USA), we examined the association of marine n-3 FAs with plasma fibrinogen. Serum FAs were measured by capillary gas-liquid chromatography. Marine n-3 FAs were defined as the sum of docosahexaenoic, eicosapentaenoic and docosapentaenoic acids. Plasma fibrinogen was measured by an automated clot-rate assay. Multiple linear regression analyses were performed to assess the association. RESULTS: White, Japanese and Japanese-American men had mean marine n-3 FAs levels of 3.47%, 8.78% and 4.46%, respectively. Japanese men had a significant inverse association of marine n-3 FAs with fibrinogen (standardized regression coefficient of -0.11, P=0.049), after adjusting for age, body-mass index and current smoking. The significant inverse association remained after further adjusting for diabetes, C-reactive protein, triglycerides and other variables. White or Japanese-American men did not show a significant association. CONCLUSIONS: We observed the significant inverse association of marine n-3 FAs with fibrinogen in Japanese, but not in whites or Japanese Americans. The observation suggests that marine n-3 FAs at very high levels, as seen in the Japanese, may decrease plasma fibrinogen levels.


Assuntos
Povo Asiático , Doenças Cardiovasculares/prevenção & controle , Dieta , Ácidos Graxos Ômega-3/farmacologia , Fibrinogênio/metabolismo , Óleos de Peixe/farmacologia , População Branca , Adulto , Doenças Cardiovasculares/sangue , Estudos Transversais , Gorduras na Dieta/farmacologia , Havaí , Humanos , Japão , Modelos Lineares , Masculino , Pessoa de Meia-Idade , Pennsylvania , Fatores de Risco
12.
Diabetologia ; 51(4): 575-82, 2008 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-18197396

RESUMO

AIMS/HYPOTHESIS: High fasting blood glucose is one of the well-known risk factors for CHD. However, in certain settings, patients cannot always be expected to fast. For example, community screenings for cardiovascular disease (CVD) risk factors in Japan are performed under non-fasting conditions to achieve high participation rates. Thus, we examined a representative cohort of the Japanese population (n=9,444, follow-up period 17.3 years) to clarify whether high casual blood glucose (CBG) can predict CVD mortality. METHODS: We defined CBG groups as follows: high CBG >or= 11.1 mmol/l or participants with a history of diabetes mellitus; borderline high, 7.77 or= 7.77 mmol/l, regardless of time since last meal. Multivariate-adjusted HRs (95% CI) of CHD mortality in high and borderline high CBG groups were 2.62 (1.46-4.67) and 2.43 (1.29-4.58), respectively. Similar results were observed for both CVD and all-cause mortality. Even within the normal blood glucose range, each 1 mmol/l increase in CBG was associated with a statistically significant increase in the HR for CVD mortality (1.12, 95% CI 1.02-1.22). Population-attributable fractions of the combined groups of high and borderline high CBG for CHD, CVD and all-cause mortality were 12.0, 4.9 and 3.5%, respectively. CONCLUSIONS/INTERPRETATION: Increases in CBG, even within the normal range, predict CVD mortality.


Assuntos
Doenças Cardiovasculares/epidemiologia , Doença das Coronárias/epidemiologia , Hiperglicemia/epidemiologia , Adulto , Idoso , Consumo de Bebidas Alcoólicas/epidemiologia , Glicemia/metabolismo , Doenças Cardiovasculares/mortalidade , Causas de Morte , Colesterol/sangue , Estudos de Coortes , Doença das Coronárias/mortalidade , Cardiopatias/epidemiologia , Cardiopatias/mortalidade , Humanos , Hipertensão/epidemiologia , Japão/epidemiologia , Pessoa de Meia-Idade , Modelos de Riscos Proporcionais , Fumar/epidemiologia
13.
Analyst ; 131(12): 1292-8, 2006 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-17124536

RESUMO

Carbon nanotubes (CNTs) are promising materials for use in amperometric biosensors. The defect sites at their ends, and on their sidewalls, are considered to be edge plane-like defects and show high electrocatalytic activity toward several biological molecules. However, electrocatalytic activity toward H(2)O(2) has not been compared among bamboo-structured CNTs (BCNTs), which have many defect sites; hollow-structured CNTs (HCNTs), which have few defect sites; edge plane pyrolytic graphite (EPG); and traditional glassy carbon (GC). The advantages of using CNTs in electrodes for biosensors are still equivocal. To confirm the utility of CNTs, we analyzed the electrochemical performance of these four carbon electrodes. The slope of the calibration curve for H(2)O(2) at potentials of both +0.6 V and -0.1 V obtained with a BCNT paste electrode (BCNTPE) was more than 10 times greater than the slopes obtained with an HCNT paste electrode and a GC electrode, reflecting the BCNT's larger number of defect sites. Although the slope with the EPG electrode (EPGE) was about 40 times greater than that with BCNTPE at +0.6 V, the slopes with these two carbon electrodes were nearly equivalent at -0.1 V. EPGE demonstrated excessive electrochemical activity, detecting currents on the basis of consumption of oxygen and oxidation of ascorbic acid, even at -0.1 V. In contrast, BCNTPE could dominantly detect a cathodic current for H(2)O(2) at -0.1 V, even when interfering molecules were added. BCNTPE possesses appropriate electrochemical activity and is an effective electrode materials for developing interference-free oxidase-based biosensors operated by the application of an appropriate potential.


Assuntos
Técnicas Biossensoriais , Glucose/análise , Animais , Eletroquímica , Eletrodos , Glucose Oxidase , Grafite , Humanos , Peróxido de Hidrogênio , Nanotubos de Carbono , Oxirredução , Termogravimetria
14.
Planta ; 165(1): 30-6, 1985 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24240954

RESUMO

Perception of polarized light inducing phytochrome-mediated polarotropism in protonemata of the fern Adiantum capillus-veneris L. was analyzed using brief microbeam irradiation with polarized red (R) or far-red light (FR). The polarotropic response inducible by irradiation of the subapical 10-30-µm part with polarized R vibrating parallel to the cell axis was nullified by subsequently giving R at the apical 0-2.5-µm region. This inhibitory effect of R showed an action dichroism, that is, polarized R vibrating normal to the cell axis was effective but the parallel-vibrating R was not. On the other hand, FR irradiation of the extreme tip after irradiation of the whole cell with depolarized R effectively induced a tropic response. This FR effect also showed action dichroism, with parallel-vibrating polarized FR being more effective than FR vibrating normal to the cell axis. When the apical-dome region and the adjacent subapical 10-20-µm region were sequentially irradiated with polarized R vibrating obliquely in different directions, polarotropism took place depending on the vibrating direction of the light given to the apical-dome region. Obliquely vibrating polarized FR given to the apical dome after irradiation of the whole cell with depolarized R also induced polarotropism. Thus, the difference in amount (or percent) of the far-redabsorbing form of phytochrome (Pfr) between the extreme tip and the subapical region appears to be crucial in regulating the direction of apical growth; the difference in Pfr level between the two sides of the protonemal apex may occur mainly at the apical dome. Furthermore, the transition moments of the red-absorbing form of phytochrome (Pr) and Pfr seem to be aligned parallel and normal, respectively, to the cell surface at the periphery of the apical hemisphere.

15.
Planta ; 165(1): 43-50, 1985 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24240956

RESUMO

An action spectrum for the low-fluencerate response of chloroplast movement in protonemata of the fern Adiantum capillus-veneris L. was determined using polarized light vibrating perpendicularly to the protonema axis. The spectrum had several peaks in the blue region around 450 nm and one in the red region at 680 nm, the blue peaks being higher than the red one. The red-light action was suppressed by nonpolarized far-red light given simultaneously or alternately, whereas the bluelight action was not. Chloroplast movement was also induced by a local irradiation with a narrow beam of monochromatic light. A beam of blue light at low energy fluence rates (7.3·10(-3)-1.0 W m(-2)) caused movement of the chloroplasts to the beam area (positive response), while one at high fluence rates (10 W m(-2) and higher) caused movement to outside of the beam area (negative response). A red beam caused a positive response at fluence rates up to 100 W m(-2), but a negative response at very high fluence rates (230 and 470 W m(-2)). When a far-red beam was combined with total background irradiation with red light at fluence rates causing a low-fluence-rate response in whole cells, chloroplasts moved out of the beam area. When blue light was used as background irradiation, however, a narrow far-red beam had no effect on chloroplast distribution. These results indicate that the light-oriented movement of Adiantum chloroplasts is caused by red and blue light, mediated by phytochrome and another, unidentified photoreceptor(s), respectively. This movement depends on a local gradient of the far-red-absorbing form of phytochrome or of a photoexcited blue-light photoreceptor, and it includes positive and negative responses for both red and blue light.

16.
J Cell Sci ; 114(Pt 2): 269-79, 2001 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-11148129

RESUMO

Light induced chloroplast movement has been studied as a model system for photoreception and actin microfilament (MF)-based intracellular motilities in plants. Chloroplast photo-accumulation and -avoidance movement is mediated by phytochrome as well as blue light (BL) receptor in the moss Physcomitrella patens. Here we report the discovery of an involvement of a microtubule (MT)-based system in addition to an MF-based system in photorelocation of chloroplasts in this moss. In the dark, MTs provided tracks for rapid movement of chloroplasts in a longitudinal direction and MFs contributed the tracks for slow movement in any direction. We found that phytochrome responses utilized only the MT-based system, while BL responses had an alternative way of moving, either along MTs or MFs. MT-based systems were mediated by both photoreceptors, but chloroplasts showed movements with different velocity and pattern between them. No apparent difference in the behavior of chloroplast movement between the accumulation and avoidance movement was detected in phytochrome responses or BL responses, except for the direction of the movement. The results presented here demonstrate that chloroplasts use both MTs and MFs for motility and that phytochrome and a BL receptor control directional photo-movement of chloroplasts through the differential regulation of these motile systems.


Assuntos
Actinas/fisiologia , Bryopsida/fisiologia , Cloroplastos/fisiologia , Microtúbulos/fisiologia , Fitocromo/fisiologia , Actinas/efeitos dos fármacos , Actinas/ultraestrutura , Bryopsida/efeitos da radiação , Bryopsida/ultraestrutura , Cloroplastos/efeitos da radiação , Cloroplastos/ultraestrutura , Citocalasina B/farmacologia , Escuridão , Luz , Iluminação , Microscopia de Fluorescência , Microtúbulos/efeitos dos fármacos , Microtúbulos/ultraestrutura , Movimento , Fototropismo , Fitocromo/efeitos da radiação
17.
Plant Physiol ; 127(2): 497-504, 2001 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11598224

RESUMO

In the fern Adiantum capillus-veneris, chloroplast movement is induced by mechanical stimulation as well as by light stimulation. Directional movement of both types depends on an actin-based motile system. To investigate the physiological relationship between mechanical and light signaling in the regulation of chloroplast movement, we examined the mechano-response of chloroplasts whose motility had been already restricted after photo-relocation. Chloroplast mechano-avoidance movement was induced under all of the photo-relocation conditions tested, indicating that mechano-specific signals generated by mechanical stimulation dominate over the light signals and reactivate the motility of chloroplasts. When the effects of external Ca(2+) on the induction of mechano- and light responses were examined, strikingly different requirements of external Ca(2+) were found for each. In medium without Ca(2+), the mechano-response was suppressed but no effects were observed on photo-response. Mechano-relocation movement of chloroplasts was inhibited by 100 microM lanthanum (La(3+)), a plasma membrane calcium channel blocker, and by 10 microM gadolinium (Gd(3+)), a stretch-activated channel blocker. However, the same concentrations of these drugs did not affect the photo-relocation movement at all. These results suggest that the influx of external Ca(2+) is crucial for the early signaling step of chloroplast mechano-relocation but not for that of photo-relocation. This is the first report showing the separation of signaling pathways in mechano- and photo-relocation of chloroplasts.


Assuntos
Actinas/metabolismo , Cálcio/farmacologia , Cloroplastos/fisiologia , Pteridaceae/citologia , Fenômenos Biomecânicos , Cálcio/metabolismo , Bloqueadores dos Canais de Cálcio/farmacologia , Cloroplastos/efeitos dos fármacos , Cloroplastos/efeitos da radiação , Citoesqueleto/efeitos dos fármacos , Citoesqueleto/fisiologia , Citoesqueleto/efeitos da radiação , Gadolínio/farmacologia , Lantânio/farmacologia , Luz , Modelos Biológicos , Movimento/efeitos dos fármacos , Movimento/efeitos da radiação , Miosinas/metabolismo , Estimulação Física , Pteridaceae/efeitos dos fármacos , Pteridaceae/metabolismo , Pteridaceae/efeitos da radiação , Transdução de Sinais
18.
Planta ; 210(6): 932-7, 2000 May.
Artigo em Inglês | MEDLINE | ID: mdl-10872225

RESUMO

The light-induced intracellular relocation of chloroplasts was examined in red-light-grown protonemal cells of the moss Physcomitrella patens. When irradiated with polarized red or blue light, chloroplast distribution in the cell depended upon the direction of the electrical vector (E-vector) in both light qualities. When the E-vector was parallel to the cross-wall (i.e. perpendicular to the protonemal axis), chloroplasts accumulated along the cross-wall; however, no accumulation along the cross-wall was observed when the E-vector was perpendicular to it (i.e. parallel to the protonemal axis). When a part of the cell was irradiated with a microbeam of red or blue light, chloroplasts accumulated at or avoided the illumination point depending on the fluence rate used. Red light of 0.1-18 W m-2 and blue light of 0.01-85.5 W m-2 induced an accumulation response (low-fluence-rate response; LFR), while an avoidance response (high-fluence-rate response; HFR) was induced by red light of 60 W m-2 or higher and by blue light of 285 W m-2. The red-light-induced LFR and HFR were nullified by a simultaneous background irradiation of far-red light, whereas the blue-light-induced LFR and HFR were not affected at all by this treatment. These results show, for the first time, that dichroic phytochrome, as well as the dichroic blue-light receptor, is involved in the chloroplast relocation movement in these bryophyte cells. Further, the phytochrome-mediated responses but not the blue-light responses were revealed to be lost when red-light-grown cells were cultured under white light for 2 d.


Assuntos
Bryopsida/fisiologia , Cloroplastos/fisiologia , Luz , Complexo de Proteínas do Centro de Reação Fotossintética/metabolismo , Fitocromo/metabolismo , Bryopsida/metabolismo , Bryopsida/efeitos da radiação , Bryopsida/ultraestrutura , Células Cultivadas
19.
Jikken Dobutsu ; 29(1): 39-43, 1980 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-7398801

RESUMO

Osteogenesis in the penial bone was observed in male rat: immature stromal cells of mesenchymal origin appeared in the penis on the 21st day of fetal age and developed to form mature bony structure with the bonemarrow on or before day 7 after birth; the bone was 1.41 +/- 0.12 mm in length. Neonatal castration caused maldevelopment of the penial bone, while prepuberal treatment with testosterone propionate stimulated the bony growth in castrated immature rat. These results suggest that the stromal cells in penile part of newborn male rats have already been destinated to develop into os penis by fetal exposure to androgen and they do not require androgens for further differentiation but for the bony growth after birth.


Assuntos
Animais Recém-Nascidos/crescimento & desenvolvimento , Desenvolvimento Ósseo/efeitos dos fármacos , Pênis/efeitos dos fármacos , Ratos/crescimento & desenvolvimento , Maturidade Sexual , Testosterona/farmacologia , Animais , Osso e Ossos/diagnóstico por imagem , Castração/veterinária , Masculino , Pênis/diagnóstico por imagem , Pênis/crescimento & desenvolvimento , Radiografia
20.
Plant Physiol ; 121(1): 37-44, 1999 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-10482658

RESUMO

Cell response to mechanical stimulation was investigated at a subcellular level in protonemal cells of the fern Adiantum capillus-veneris L. by pressing a small part of the cell with a microcapillary. In cells receiving local stimulation, the chloroplasts moved away from the site of stimulation, whereas the nuclei failed to show such avoidance movement. Mechanical stimulation for a period as short as 0.3 min was enough to induce the avoidance response to a maximal level. The avoidance movement of chloroplasts started within 30 min and the plateau level of avoidance was attained around 2 h after stimulation. By tracing the movement of chloroplasts during the response, it was shown that the mobility of chloroplasts near the stimulation site increased transiently within 1 h after the stimulation. After 2 to 3 h, it slowed down to the control level without stimulation. The avoidance response was inhibited by 0.1 mM cytochalasin B and 25 mM 2, 3-butanedione monoxime but not by 3.3 microM amiprophosmethyl or 5 mM colchicine. These findings indicate that the protonemal cells were very sensitive to mechanical stimulation and that chloroplasts moved away from the mechanically stimulated site through the actomyosin motile system.


Assuntos
Cloroplastos/fisiologia , Movimento , Células Vegetais , Actomiosina/metabolismo , Núcleo Celular/fisiologia , Cloroplastos/efeitos dos fármacos , Colchicina/farmacologia , Citocalasina B/farmacologia , Citoesqueleto/efeitos dos fármacos , Citoesqueleto/fisiologia , Diacetil/análogos & derivados , Diacetil/farmacologia , Modelos Biológicos , Movimento/efeitos dos fármacos , Nitrobenzenos , Compostos Organotiofosforados/farmacologia , Estimulação Física , Plantas/efeitos dos fármacos , Plantas/metabolismo , Fatores de Tempo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA