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1.
Rev Sci Instrum ; 94(7)2023 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-37498166

RESUMO

The Kamioka Gravitational wave detector (KAGRA) cryogenic gravitational-wave observatory has commenced joint observations with the worldwide gravitational wave detector network. Precise calibration of the detector response is essential for accurately estimating parameters of gravitational wave sources. A photon calibrator is a crucial calibration tool used in laser interferometer gravitational-wave observatory, Virgo, and KAGRA, and it was utilized in joint observation 3 with GEO600 in Germany in April 2020. In this paper, KAGRA implemented three key enhancements: a high-power laser, a power stabilization system, and remote beam position control. KAGRA employs a 20 W laser divided into two beams that are injected onto the mirror surface. By utilizing a high-power laser, the response of the detector at kHz frequencies can be calibrated. To independently control the power of each laser beam, an optical follower servo was installed for power stabilization. The optical path of the photon calibrator's beam positions was controlled using pico-motors, allowing for the characterization of the detector's rotation response. Additionally, a telephoto camera and quadrant photodetectors were installed to monitor beam positions, and beam position control was implemented to optimize the mirror response. In this paper, we discuss the statistical errors associated with the measurement of relative power noise. We also address systematic errors related to the power calibration model of the photon calibrator and the simulation of elastic deformation effects using finite element analysis. Ultimately, we have successfully reduced the total systematic error from the photon calibrator to 2.0%.

2.
AJNR Am J Neuroradiol ; 40(4): 601-608, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30923084

RESUMO

BACKGROUND AND PURPOSE: The effects of multiple head impacts, even without detectable primary injury, on subsequent behavioral impairment and structural abnormality is yet well explored. Our aim was to uncover the dynamic changes and long-term effects of single and repetitive head injury without focal contusion on tissue microstructure and macrostructure. MATERIALS AND METHODS: We introduced a repetitive closed-head injury rodent model (n = 70) without parenchymal lesions. We performed a longitudinal MR imaging study during a 50-day study period (T2-weighted imaging, susceptibility-weighted imaging, and diffusion tensor imaging) as well as sequential behavioral assessment. Immunohistochemical staining for astrogliosis was examined in a subgroup of animals. Paired and independent t tests were used to evaluate the outcome change after injury and the cumulative effects of impact load, respectively. RESULTS: There was no gross morphologic evidence for head injury such as skull fracture, contusion, or hemorrhage on micro-CT and MR imaging. A significant decrease of white matter fractional anisotropy from day 21 on and an increase of gray matter fractional anisotropy from day 35 on were observed. Smaller mean cortical volume in the double-injury group was shown at day 50 compared with sham and single injury (P < .05). Behavioral deficits (P < .05) in neurologic outcome, balance, and locomotor activity were also aggravated after double injury. Histologic analysis showed astrogliosis 24 hours after injury, which persisted throughout the study period. CONCLUSIONS: There are measurable and dynamic changes in microstructure, cortical volume, behavior, and histopathology after both single and double injury, with more severe effects seen after double injury. This work bridges cross-sectional evidence from human subject and pathologic studies using animal models with a multi-time point, longitudinal research paradigm.


Assuntos
Concussão Encefálica/complicações , Concussão Encefálica/patologia , Transtornos Neurológicos da Marcha/etiologia , Transtornos de Sensação/etiologia , Animais , Estudos Transversais , Imagem de Tensor de Difusão/métodos , Modelos Animais de Doenças , Substância Cinzenta/patologia , Traumatismos Cranianos Fechados/complicações , Traumatismos Cranianos Fechados/patologia , Estudos Longitudinais , Masculino , Ratos , Ratos Sprague-Dawley , Substância Branca/patologia
3.
Obes Sci Pract ; 4(3): 268-275, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29951217

RESUMO

OBJECTIVE: This study was conducted to determine the role of obesity and race in intracerebral haemorrhage (ICH) outcomes. METHODS: The Get with the guideline-Stroke database was queried for all admitted patients with spontaneous ICH. Secondary causes of ICH were excluded. Body mass index (BMI) was classified using the Center for Disease Control guidelines. Race was classified as White or non-White. Demographics, clinical, imaging data were retrieved. Outcome measures were hematoma expansion at 24 h and discharge disposition. RESULTS: A total of 428 patients were included in our analysis. Female gender, past history of congestive heart failure, diabetes mellitus, HbA1c, blood pressure, ICH volume, ICH location, intraventricular haemorrhage and hospital length of stay deferred across BMI categories. On multivariate analysis, along with obese categories, age, ICH location and ICH volume were independent predictors of poor outcomes (hematoma expansion and poor discharge disposition). After adjusting for these variables, obesity remained a predictor of poor disposition outcome compared with normal and overweight subjects; Normal vs. Obese OR 0.26 CI 0.115-0.593 p = 0.0014; Obese vs. Overweight OR 3.79 CI 1.68-8.52 p = 0.0013. Nonetheless, obesity did not influence hematoma expansion. Overall, BMI-race classification did not influence outcomes. However, among non-Whites, the obese category had higher odds of a poor disposition outcome than normal (OR 6.84 CI 2.12-22.22 p = 0.0013) or overweight (OR 8.45 CI 2.6-27.49 p = 0.0004) categories. CONCLUSION: An obesity paradox in ICH was not observed in our cohort. In the non-White population, patients with obesity were likely to be associated with poor disposition outcome. Similar findings were not observed in White population.

4.
Opt Express ; 22 Suppl 7: A1853-61, 2014 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-25607499

RESUMO

We demonstrated photoelectrochemical cells (PECs) with dodecagon faceted AlGaN/n-GaN heterostructure electrode for H(2) generation, where the AlGaN/n-GaN heterostructure has a linear gradient Al composition (LGAC). The separation efficiency of the photo-generated electron-hole pairs in the electrode performs a key function in the H(2) generation efficiency of PEC cells. The linear gradient Al composition, AlGaN, could create more internal field and light absorption because of the linear graded band gap. Therefore, the zero-bias photocurrent density of PEC cells with dodecagon facet LGAC AlGaN/n-GaN heterostructure electrode is around 5.9 times larger than that of dodecagon faceted n-GaN electrode.

5.
J Nanosci Nanotechnol ; 11(12): 10485-8, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22408931

RESUMO

The gap state density of nano-crystalline silicon active layers on a flexible substrate was redistributed with mechanical bending. The weak or broken bonds may contribute to the redistribution of trap states. During mechanical strain, the deep states redistributed in a Gaussian distribution, and are dissimilar to ordinary acceptor-like deep states, which manifest with exponential distributions. We conclude that the gap state density with TCAD modeling under mechanical strain is the fundamental reliability issue for the development of flexible electronics.

6.
Reprod Biomed Online ; 16(6): 772-7, 2008 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18549685

RESUMO

Previous studies have shown that ovarian stimulation with clomiphene citrate (CC), human menopausal gonadotrophin (HMG), and multiple-dose gonadotrophin-releasing hormone (GnRH) antagonist is associated with a high rate of premature LH surge. This study assessed whether administration of the GnRH antagonist cetrorelix at an incremental dose or at a high dose (0.5mg) from the start could prevent premature LH surge. Couples with male factor or unexplained infertility who were going to undergo intrauterine insemination were randomized into two stimulation protocols. All women were stimulated with CC and HMG. In protocol A, cetrorelix was given at 0.25 mg per day when the leading follicles reached 14 mm, and increased to 0.5 mg when the leading follicles were 16 mm. With protocol B, cetrorelix was given at 0.5 mg per day when the leading follicles reached 14 mm. The primary outcome measure was the incidence of premature LH surge. Premature LH surge occurred in 21.6% of patients undergoing protocol A, and in 18.9% of patients undergoing protocol B. Cetrorelix at incremental dose or at 0.5 mg per day does not prevent premature LH surges associated with the CC/HMG/multiple-dose cetrorelix stimulation protocol.


Assuntos
Hormônio Liberador de Gonadotropina/análogos & derivados , Hormônio Liberador de Gonadotropina/antagonistas & inibidores , Hormônio Luteinizante/sangue , Indução da Ovulação/métodos , Adulto , Clomifeno/administração & dosagem , Feminino , Hormônio Liberador de Gonadotropina/administração & dosagem , Humanos , Masculino , Menotropinas/administração & dosagem
7.
QJM ; 101(1): 13-22, 2008 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-18203722

RESUMO

BACKGROUND: Primary aldosteronism (PA) is a common curable disease of secondary hypertension. Most such patients have either idiopathic bilateral adrenal hyperplasia (BAH) or unilateral aldosterone-producing adenoma (APA). Bilateral APAs are reportedly extremely rare. AIM: To compare the distinctive characteristics, clinical course, and outcomes of bilateral APA vs. BAH. DESIGN: Retrospective record review. METHODS: From July 1994 to Jan 2007, 190 patients diagnosed with PA underwent surgical intervention at our hospital. Bilateral APA was diagnosed in 7/164 patients with histologically-proven APA. Twenty-one patients diagnosed as BAH, and 21 randomly selected of unilateral APA patients, matched by age and sex served as controls. RESULTS: Patients with bilateral APA had similar blood pressure, arterial blood gas analysis, spot urinary potassium to creatinine ratio and clinical symptoms to those with BAH, but lower serum potassium levels (p = 0.027), lower plasma renin activity (p = 0.037), and higher plasma aldosterone concentrations (p = 0.029). Aldosterone-renin ratio (ARR) after administration of 50 mg captopril was higher in bilateral APA than in BAH patients (p = 0.023), but not different between unilateral APA and BAH (p = 0.218). A cut-off of ARR >100 ng/dl per ng/ml/h and plasma aldosterone >20 ng/dl after captopril significantly differentiated bilateral APA from BAH. Bilateral subtotal adrenalectomy normalized blood pressure and biochemistry in all patients with bilateral APA. DISCUSSION: Bilateral APA, presenting simultaneously or sequentially, may not be a rare disease, accounting for 4.3% of APA in this sample. The clinical presentations of bilateral functional adenoma are not different from BAH, but patients with low serum potassium and ARR >100 after captopril should be carefully evaluated for bilateral adenoma.


Assuntos
Adenoma/metabolismo , Neoplasias do Córtex Suprarrenal/metabolismo , Glândulas Suprarrenais/patologia , Aldosterona/biossíntese , Adenoma/diagnóstico por imagem , Adenoma/patologia , Neoplasias do Córtex Suprarrenal/diagnóstico por imagem , Neoplasias do Córtex Suprarrenal/patologia , Glândulas Suprarrenais/metabolismo , Adulto , Idoso , Estudos de Casos e Controles , Feminino , Humanos , Hiperaldosteronismo/metabolismo , Hiperaldosteronismo/patologia , Hiperplasia/metabolismo , Hiperplasia/patologia , Masculino , Pessoa de Meia-Idade , Radiografia , Estudos Retrospectivos
8.
Clin Nephrol ; 58(5): 363-9, 2002 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-12425487

RESUMO

BACKGROUND: The diagnosis of iron deficiency using the current commonly used tests is usually difficult in hemodialysis patients. Soluble transferrin receptor (sTfR) has caught the attention of physicians recently as regards its use as a parameter for the evaluation of iron status. This study was conducted in order to evaluate the correlation of serum soluble transferrin receptor (sTfR) concentration with hematological parameters and iron profiles, in the role of identifying iron deficiency among dialysis patients. METHODS: Seventy-three patients having received chronic hemodialysis and stable maintenance recombinant human erythropoietin (rHuEPO) therapy were included. Iron, total iron-binding capacity, ferritin and sTfR were measured in the first week. Following this, these patients began to receive intravenous iron dextran (2 mg/kg/week) for 4 weeks. The hematocrit (Hct), hemoglobin (Hb) levels and reticulocyte counts were evaluated weekly. At the beginning of fifth week, the sTfR level was measured again. Patients were classified as belonging to one of the following groups: serum ferritin < 100 microg/L - absolute iron-deficient group; initial ferritin level > or = 100 microg/L with an increase in hemoglobin of greater than 1 g/dL at the end of the study occult iron deficiency group; others - non iron-deficient group. RESULTS: Seventy-one patients completed the study. The concentration of sTfR was positively correlated with Hct, Hb and reticulocyte index at the beginning (r = 0.236, p = 0.047; r = 0.257, p = 0.04; r = 0.401, p < 0.01, respectively) and at the end of the study (r = 0.384, p < 0.01; r = 0.338, p < 0.01; r = 0.427, p < 0.001, respectively). After 4 weeks of iron and rHuEPO therapy, the sTfR concentration increased, rather than declined, from 21.85 +/- 8.06 nM to 23.76 +/- 7.42 nM (p = 0.04) and the change was positively correlated with the changes in Hct, Hb and reticulocyte index. The administered rHuEPO doses did not differbetween the iron deficiency group (absolute deficiency, n = 3; occult deficiency, n = 10) and non-iron deficiency group (n = 58). The sTfR levels failed to identify the occult iron deficiency group because there was no difference between occult iron-deficient and non-iron-deficient patients (24.73 +/- 9.09 nM versus 21.60 +/- 7.89 nM, p = 0.34). Instead, transferrin saturation (TS) could be a differential marker between the 2 groups (19.0 +/- 10.9% versus 30.1 +/- 12.7%, p = 0.012). CONCLUSION: The serum sTfR concentration is indeed an appropriate marker for erythropoiesis. The erythropoitic effect of administered rHuEPO could mask the effect of iron status on the sTfR concentration. This might make the sTfR concentration no longer an appropriate index to identify the presence of occult iron deficiency. Thus, TS and ferritin currently remain better methods for the evaluation of iron status in rHuEPO-treated chronic hemodialysis patients.


Assuntos
Anemia Ferropriva/sangue , Anemia Ferropriva/terapia , Eritropoese/fisiologia , Eritropoetina/uso terapêutico , Falência Renal Crônica/sangue , Falência Renal Crônica/terapia , Receptores da Transferrina/sangue , Diálise Renal , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Anemia Ferropriva/fisiopatologia , Feminino , Humanos , Falência Renal Crônica/fisiopatologia , Masculino , Pessoa de Meia-Idade , Proteínas Recombinantes , Reprodutibilidade dos Testes , Fatores de Tempo , Transferrina/análise
9.
J Formos Med Assoc ; 100(9): 598-603, 2001 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11695274

RESUMO

BACKGROUND AND PURPOSE: Adrenal venous sampling is the most reliable test to distinguish aldosterone-producing adenoma (APA) from idiopathic hyperaldosteronism (IHA). The diagnostic accuracy can be improved by administration of adrenocorticotropin to minimize pulsatile secretion of aldosterone. Metoclopramide (MCP), a dopamine antagonist, can increase aldosterone secretion promptly without affecting cortisol secretion. This study investigated the diagnostic accuracy of adrenal venous sampling after MCP injection for the preoperative diagnosis and localization of APA. METHODS: Prospective diagnosis and adrenalectomy was based on adrenal venous sampling in 23 patients with a diagnosis of primary aldosteronism. Plasma aldosterone concentrations from adrenal veins and the inferior vena cava were measured before and 30 minutes after intravenous administration of 10 mg MCP. The ratio of bilateral adrenal venous aldosterone concentrations after MCP was used for diagnosis as follows: a ratio greater than 5 indicated APA, less than 3 indicated IHA, and 3-5 indicated an intermediate diagnosis. RESULTS: Catheterization of the right adrenal vein was unsuccessful in three patients. Twelve of 13 patients with an aldosterone ratio greater than 5 after MCP underwent unilateral adrenalectomy, and APA was confirmed in 11 of these patients. One patient with an intermediate diagnosis also had surgically confirmed APA. Six patients had a ratio less than 3. Before MCP administration, 10 of 13 patients with APA had a ratio greater than 5, and three patients had a ratio between 3 and 5; one patient with IHA had a ratio greater than 5. MCP improved the diagnosis of APA to an accuracy of 92% (12/13). Correct diagnosis of APA based on computerized tomography (CT) was 85% (11/13). There was discordance between the findings of adrenal venous sampling and CT in four of 20 patients. CONCLUSIONS: Administration of MCP to stimulate aldosterone secretion during adrenal venous sampling can improve the accuracy of differential diagnosis between APA and IHA.


Assuntos
Adenoma/diagnóstico , Neoplasias das Glândulas Suprarrenais/diagnóstico , Glândulas Suprarrenais/irrigação sanguínea , Aldosterona/metabolismo , Hiperaldosteronismo/diagnóstico , Metoclopramida , Hormônio Adrenocorticotrópico/farmacologia , Adulto , Idoso , Aldosterona/sangue , Diagnóstico Diferencial , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
10.
J Immunol ; 167(8): 4566-73, 2001 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-11591785

RESUMO

It has long been recognized that some viral infections result in generalized immune suppression. In acute infections, this period of suppressed immunity is relatively short. However, chronic infections associated with a prolonged period of immune suppression present far greater risks. Here, we examined the role of CD8 T cell responses following viral infection in immunity to systemic histoplasmosis. Although wild-type mice with systemic histoplasmosis were able to control the infection, those simultaneously infected with lymphocytic choriomeningitis virus clone 13 showed reduced immunity with greater fungal burden and high mortality. The immune suppression was associated with loss of CD4 T cells and B cells, generalized splenic atrophy, and inability to mount a granulomatous response. Removing the anti-viral CD8 T cells in the coinfected mice enabled them to reduce the fungal burden and survive the infection. Their lymphoid organs were replenished with CD4 T and B cells. In contrast to wild-type mice, perforin-deficient mice infected with lymphocytic choriomeningitis virus clone 13 and Histoplasma showed an absence of immunopathology, but the animals still died. These results show that CD8 T cells can suppress immunity through different mechanisms; although immunopathology is perforin-dependent, lethality is perforin-independent.


Assuntos
Infecções por Arenaviridae/imunologia , Linfócitos T CD8-Positivos/imunologia , Histoplasmose/imunologia , Vírus da Coriomeningite Linfocítica/imunologia , Animais , Infecções por Arenaviridae/complicações , Doença Crônica , Suscetibilidade a Doenças , Histoplasmose/complicações , Tolerância Imunológica , Depleção Linfocítica , Tecido Linfoide/imunologia , Glicoproteínas de Membrana/deficiência , Glicoproteínas de Membrana/imunologia , Camundongos , Perforina , Proteínas Citotóxicas Formadoras de Poros , Baço/patologia
11.
Nucl Med Biol ; 28(7): 835-44, 2001 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11578906

RESUMO

UNLABELLED: In this study, the effectiveness of a 188Re labeled sulfur colloid with two particle size ranges was used to evaluate the effectiveness of this agent on melanoma tumors in mice in terms of animal lifespan. METHODS: Two separate group of animals were used for investigating biodistribution and survival time. A total of 188 B16F10-melanoma-bearing BDF(1) mice were injected intraperitoneally with 3.7 MBq (0.1mCi)/2mL of radiolabeled sulfur colloid ten days after intraperitoneal inoculation of 5x10(5) B16F10 melanoma cells/2ml. For group 1, 30 mice were sacrificed at 1, 4, 24, 48 and 72 hours for biodistribution studies. In group 2, 158 mice were divided into 9 groups (n=16 approximately 18/groups)each receiving respectively tumor alone, tumor with normal saline, cold colloid or hot colloid with 16, 23, 31, 46, 62, or 124 MBq activity. Each of these colloid groups was further divided into two groups, one receiving smaller particle sizes (<3 microm:80.4 +/-7.2%, colloid 1) and the other receiving larger particle sizes (<3 microm:12.3+/-1.0%, colloid 2). The animals were checked daily until death and their survival recorded. RESULTS: Colloid 2 showed higher accumulation in almost all tissues, the highest accumulation organ was tumor ( approximately 40%), then spleen ( approximately 20%), stomach ( approximately 15%), diaphragm ( approximately 3%), and liver ( approximately 2%). There was a significant increase in survival time with increasing amount of the larger-particle-size colloid. Administered levels of 16-31 MBq/mouse were most efficacious and with higher amounts the survival times decreased significantly below that of the controls. There was a significant difference in the dose-response curves for the two preparations. Protection factors (1/Relative-risk) of nearly 5 were achieved using the larger colloid size, and nearly 30 using the smaller colloid size. An amount of 16-31 MBq of the colloid 2 was the optimal activity in these studies. On the one hand, the survival data agreed well with the biodistribution data, where higher accumulation was found in tumor with colloid 2. CONCLUSION: Rhenium-188 offers on-site availability, medium half-life, higher beta-particle energy of 2.12 MeV for therapy and emission of 155keV gamma photon suitable for imaging. The present study demonstrated that 188Re-sulfur colloid is an effective agent in controlling tumor cells in the abdominal cavity in animals.


Assuntos
Melanoma Experimental/radioterapia , Compostos Radiofarmacêuticos/uso terapêutico , Enxofre/uso terapêutico , Animais , Estabilidade de Medicamentos , Melanoma Experimental/metabolismo , Camundongos , Camundongos Endogâmicos , Tamanho da Partícula , Compostos Radiofarmacêuticos/química , Compostos Radiofarmacêuticos/farmacocinética , Enxofre/química , Enxofre/farmacocinética , Análise de Sobrevida , Distribuição Tecidual
12.
Neurotoxicology ; 22(4): 423-7, 2001 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-11577800

RESUMO

Organophosphate poisonings are not uncommon, and are the leading cause of death in suicide patients in Taiwan. Acute cholinergic crisis caused by the inhibition of synaptic acetylcholinesterase is the major manifestation of organophosphate poisoning and may cause death within minutes. Delayed neurotoxicities include intermediate syndrome and delayed polyneuropathy have also been described. However, these symptoms may not characterize the complete picture of organophosphate poisoning. Among the 633 patients ever admitted to our hospital with organophosphate poisoning, three patients were found exhibiting impermanent neuromuscular dysfunction, including blepharoclonus, oculogyric crisis, intermittent dystonia, rigidity, and tremor, with two of them developing mask face, dyskinesia and akathisia later, following acute cholinergic crisis. The symptoms appeared within 4 days with the duration ranging from 25 days to 2 months. Other causes of the extrapyramidal syndrome noted on these patients have been excluded, and we consider the extrapyramidal syndrome a possible neurotoxic manifestation of organophosphate poisoning, which is transient, needs no treatment, and may be missed because of the critical condition, in a minority of patients. The mechanism remains to be identified, but may be related to the impediment of the function of acetylcholinesterase to modify nigrostriatal dopaminergic system, which is independent of hydrolyzing acetylcholine. More detailed observation for organophosphate poisoned patients and more studies for the biological functions of acetylcholinesterase including the influence on the nigrostriatal dopaminergic system are needed.


Assuntos
Doenças dos Gânglios da Base/induzido quimicamente , Inibidores da Colinesterase/efeitos adversos , Inseticidas/efeitos adversos , Compostos Organofosforados , Acetilcolinesterase , Adulto , Idoso , Doenças dos Gânglios da Base/tratamento farmacológico , Feminino , Humanos , Masculino , Antagonistas Muscarínicos/uso terapêutico , Síndrome
13.
Clin Nephrol ; 56(3): 236-40, 2001 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11597039

RESUMO

Forty-nine patients who had received radiocephalic hemodialysis fistula construction were evaluated with duplex Doppler ultrasonography to characterize the Doppler indices of the feed radial arteries just proximal to the site of anastomosis. Forty-four patients had fistulas with good function, and 5 patients had fistulas with inadequate blood flow or thrombosis within 4 weeks after the operation. A preliminary study showed extensive variability in peak systolic velocity and end-diastolic velocity in the feed arteries. The resistive index dropped significantly 1 week after the operation and remained relatively constant over the following 5 weeks. In the success group, the mean resistive index measured 1 week after operation was 0.40+/-0.06. It was higher than that of the failure group (mean resistive index: 0.52+/-0.06). Among patients with well-functioning fistulas, diabetic patients had higher resistive indices than did non-diabetic patients (0.44+/-0.04 vs. 0.37+/-0.06). Our results suggest that a higher resistive index of the feed artery is closely related to early autogenous primary hemodialysis fistula failure.


Assuntos
Derivação Arteriovenosa Cirúrgica , Artéria Radial/cirurgia , Diálise Renal , Resistência Vascular , Adulto , Idoso , Idoso de 80 Anos ou mais , Braço/irrigação sanguínea , Derivação Arteriovenosa Cirúrgica/efeitos adversos , Velocidade do Fluxo Sanguíneo , Cateteres de Demora , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Artéria Radial/fisiopatologia , Fatores de Risco , Trombose/etiologia , Ultrassonografia Doppler Dupla , Veias/cirurgia
14.
Kidney Int ; 60(3): 872-81, 2001 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11532082

RESUMO

BACKGROUND: It has been proposed that proliferation of human peritoneal mesothelial cells (HPMCs) accompanied by collagen synthesis may contribute to the development of peritoneal fibrosis (PF) in patients of long-term continuous ambulatory peritoneal dialysis (CAPD). However, the precise molecular mechanism regulating HPMC proliferation has never been reported. Dipyridamole has been reported to have potential as an antiproliferative and antifibrotic agent. We investigated the mechanism and effect of dipyridamole in regulation of HPMC proliferation. METHODS: HPMCs were cultured from human omentum by an enzyme digestion METHOD: Cell proliferation was measured by the methyltetrazolium assay and intracellular cAMP was measured using an enzyme immunoassay kit. Cell-cycle distribution of HPMC was analyzed by flow cytometry. Extracellular signal-regulated protein kinase (p44/p42 ERK) activity and expressions of cell-cycle proteins (cyclin D(1), CDK4, pRB and p27(Kip1)) were determined by Western blotting. RESULTS: The addition of DP suppressed PDGF-stimulated HPMC proliferation by cell-cycle arrest at the G1 phase. The antimitogenic effect of dipyridamole was mediated through the cAMP pathway. PDGF (25 ng/mL) increased the ERK1/2 activity of HPMC within 15 minutes, which maximized at 30 minutes, and the pretreatment with dipyridamole (17 microg/mL) substantially reduced the ERK response to PDGF by approximately 78.5%. PDGF induced elevated protein levels of cyclin D(1), but the CDK4 protein level did not change. Dipyridamole and DBcAMP had no effect on the levels of cyclin D(1) and CDK4 in PDGF-stimulated HPMC. PDGF decreased p27(Kip1) and induced pRB phosphorylation of HPMC. In contrast, dipyridamole prevented PDGF-induced p27(Kip1) degradation and attenuated PDGF-stimulated pRB phosphorylation. CONCLUSION: Dipyridamole appears to inhibit PDGF-stimulated HPMC proliferation through attenuated ERK activity, preservation of p27(Kip1), and decreased pRB phosphorylation. Thus, dipyridamole may have therapeutic efficacy to prevent or alleviate PF.


Assuntos
Proteínas de Ciclo Celular/metabolismo , Dipiridamol/farmacologia , Inibidores Enzimáticos/farmacologia , Peritônio/efeitos dos fármacos , Fator de Crescimento Derivado de Plaquetas/antagonistas & inibidores , Proteínas Supressoras de Tumor , Bucladesina/farmacologia , Divisão Celular/efeitos dos fármacos , AMP Cíclico/metabolismo , Inibidor de Quinase Dependente de Ciclina p27 , Ciclinas/metabolismo , Ativação Enzimática , Células Epiteliais/efeitos dos fármacos , Fase G1 , Humanos , Proteínas Quinases Ativadas por Mitógeno/antagonistas & inibidores , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Peritônio/citologia , Peritônio/metabolismo
15.
Kidney Int ; 60(4): 1249-57, 2001 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11576339

RESUMO

BACKGROUND: Peritoneal matrix accumulation is characteristic of peritoneal fibrosis (PF). Continuous ambulatory peritoneal dialysis (CAPD) patients who had persistent transforming growth factor-beta (TGF-beta) in their drained effluent had an increased risk of PF. We previously reported that TGF-beta stimulates the expression of types I and III collagen mRNA in cultured human peritoneal mesangial cells (HPMCs), which may predispose them to develop PF. Pharmacological interventions to attenuate TGF-beta-stimulated matrix accumulation in HPMC may have therapeutic potential for the treatment of PF. The SMAD family and the extracellular signal-regulated protein kinase (ERK1/2, p44/p42) pathways have been shown to participate in TGF-beta signaling. Our current study identified these signal pathways in HPMCs and investigated the molecular mechanisms involved in the inhibitory effects of dipyridamole on TGF-beta-induced collagen gene expression in HPMCs. METHODS: HPMCs were cultured from human omentum by an enzyme digestion METHOD: Expression of collagen alpha1(I) mRNA was determined by Northern blotting. The SMAD proteins and the ERK1/2 activity were determined by Western blotting. RESULTS: TGF-beta-stimulated collagen alpha1(I) mRNA expression of HPMC was inhibited by dipyridamole in a dose-dependent manner. Smad2 and ERK1/2 were activated in response to TGF-beta; however, TGF-beta had little effect on the protein expression of Smad4. The addition of PD98059, which blocked activation of ERK1/2, suppressed TGF-beta-induced collagen alpha1(I) mRNA expression in a dose-dependent manner. At a concentration that inhibited collagen gene expression (17 microg/mL), dipyridamole suppressed ERK1/2 activation by TGF-beta. In contrast, the same concentration of dipyridamole had no effect on TGF-beta-induced activation of Smad2. CONCLUSION: Dipyridamole inhibits TGF-beta-induced collagen gene expression in HPMC through modulation of the ERK pathway. Our study of dipyridamole may provide therapeutic basis for clinical applications in the prevention of PF.


Assuntos
Colágeno/genética , Dipiridamol/farmacologia , Expressão Gênica/efeitos dos fármacos , Cavidade Peritoneal/fisiologia , Fator de Crescimento Transformador beta/farmacologia , Células Cultivadas , Colágeno Tipo I/genética , Colágeno Tipo III/genética , Proteínas de Ligação a DNA/metabolismo , Proteínas de Ligação a DNA/fisiologia , Ativação Enzimática/efeitos dos fármacos , Células Epiteliais/fisiologia , Humanos , Proteínas Quinases Ativadas por Mitógeno/antagonistas & inibidores , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Cavidade Peritoneal/citologia , RNA Mensageiro/metabolismo , Proteína Smad2 , Proteína Smad4 , Transativadores/metabolismo , Transativadores/fisiologia
16.
Clin Infect Dis ; 33(8): 1336-40, 2001 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-11565073

RESUMO

We sought to understand the persistence and relevance of the long-lived immune response to early secretory antigenic target (ESAT-6) of Mycobacterium tuberculosis in humans. ESAT-6 is recognized by memory cells involved in protection of animals against tuberculosis (TB). Recent reports also showed that ESAT-6 response can be recovered in patients with TB and in those soon after anti-TB therapy. We chose 18 individuals who had recovered from pulmonary TB (some in remission for >5 years), and 14 bacille Calmette-Guérin-vaccinated healthy individuals for this study. The results showed that peripheral blood mononuclear cells of 10 (55.6%) of 18 patients with TB remission responded to ESAT-6 with stimulation indices >3.0, whereas none of the healthy controls responded. Functional analysis showed that 13 (72.2%) of 18 patients with TB remission produced significant amounts of IFN-gamma in response to ESAT-6, whereas only 1 (7.1%) of the 14 healthy control subjects did so. It appears that responses to ESAT-6 can persist in individuals who had recovered from pulmonary TB.


Assuntos
Antígenos de Bactérias/imunologia , Mycobacterium tuberculosis/imunologia , Tuberculose Pulmonar/imunologia , Adulto , Idoso , Vacina BCG/imunologia , Proteínas de Bactérias , Feminino , Humanos , Interferon gama/biossíntese , Leucócitos Mononucleares/imunologia , Ativação Linfocitária , Masculino , Pessoa de Meia-Idade , Fatores de Tempo
17.
Nucl Med Biol ; 28(6): 727-32, 2001 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-11518655

RESUMO

Rhenium-188 microsphere is a relatively new radiation synovectomy agent developed for the treatment of rheumatoid arthritis. It has been shown that the levels of unwanted extra-articular radiation are negligible with this agent. A histologic study was conducted to assess the effect of radiation synovectomy on synovium and articular cartilage after intra-articular injection of various doses of Re-188 microspheres into the knee joints of rabbits. Intra-articular injection of Re-188 microspheres into rabbit knee joints resulted in mild reactive inflammation and thrombotic occlusion of vessels which subsided rapidly. Sclerosis of subsynovium could be seen 12 weeks after injection. No evidence of damage to articular cartilage was noted. There was no significant difference in the articular pattern after injection of 0.3 or 0.6 mCi Re-188 microspheres. This study suggests that a treatment dose of Re-188 microspheres causes transient inflammation of synovium without any detectable damage to the articular cartilage of knee joint.


Assuntos
Artrite Reumatoide/radioterapia , Cartilagem Articular/efeitos da radiação , Radioisótopos/farmacologia , Rênio/farmacologia , Líquido Sinovial/efeitos da radiação , Animais , Antirreumáticos/farmacologia , Antirreumáticos/uso terapêutico , Cartilagem Articular/efeitos dos fármacos , Cartilagem Articular/patologia , Articulação do Joelho/efeitos da radiação , Masculino , Microesferas , Coelhos , Radioisótopos/uso terapêutico , Rênio/uso terapêutico
18.
Kidney Int ; 59(6): 2316-24, 2001 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-11380836

RESUMO

BACKGROUND: Peritoneal fibrosis (PF) is one of the most serious complications after long-term continuous ambulatory peritoneal dialysis (CAPD). Proliferation of human peritoneal mesothelial cells (HPMC) and matrix over-production are regarded as the main processes predisposing to PF. Dipyridamole (DP) has been reported to have potential as an antiproliferative and antifibrotic agent. We thus investigated the effect of DP in inhibiting proliferation and collagen synthesis of HPMC. A rat model of peritonitis-induced PF was also established to demonstrate the in vivo preventive effect of DP. METHODS: HPMC was cultured from human omentum by an enzyme digestion METHOD: Cell proliferation was measured by the methyltetrazolium assay. Intracellular cAMP was measured using an enzyme immunoassay (EIA) kit. Total collagen synthesis was measured by (3)H-proline incorporation assay. Expression of collagen alpha1 (I) and collagen alpha 1 (III) mRNAs was determined by Northern blotting. The rat model of peritonitis-induced PF was developed by adding dextran microbeads (Cytodex, 8 mg/1 mL volume) to a standardized suspension (3 x 10(9)) of Staphylococcus aureus. DP was administrated via intravenous infusion (4 mg in 1 h) daily for seven days. Macroscopic grading of intraperitoneal adhesions and histological analyses of peritoneal thickness and collagen expression were performed. RESULTS: Addition of DP to HPMC cultures suppressed serum-stimulated cell proliferation and collagen synthesis. The antimitogenic and antifibrotic effects of DP appear to be predominantly mediated through the cAMP pathway, as DP increased intracellular cAMP in a dose-dependent manner. The macroscopic grade of intraperitoneal adhesion and peritoneal thickness were both significantly increased in animals treated with Cytodex plus S. aureus; on the other hand, DP attenuated these fibrotic changes with statistical significance (P < 0.01). Analysis of gene expression of collagen alpha 1 (I) and alpha1 (III) in the peritoneal tissue of experimental animals yielded similar results. CONCLUSIONS: This study suggests that dipyridamole may have therapeutic potential in treating peritoneal fibrosis.


Assuntos
Dipiridamol/farmacologia , Peritônio/efeitos dos fármacos , Peritônio/patologia , Inibidores de Fosfodiesterase/farmacologia , Animais , Adesão Celular/efeitos dos fármacos , Divisão Celular/efeitos dos fármacos , Células Cultivadas , Colágeno/genética , AMP Cíclico/metabolismo , Modelos Animais de Doenças , Epitélio , Fibrose , Expressão Gênica/fisiologia , Humanos , Técnicas In Vitro , Masculino , Omento/citologia , Diálise Peritoneal Ambulatorial Contínua , Peritonite/tratamento farmacológico , Peritonite/metabolismo , RNA Mensageiro/análise , Ratos , Ratos Wistar
19.
J Reprod Med ; 46(3): 249-52, 2001 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-11304867

RESUMO

BACKGROUND: Microsurgical epididymal sperm aspiration (MESA) and percutaneous epididymal sperm aspiration (PESA) are two methods of obtaining spermatozoa from patients with irreparable obstructive azoospermia. Intentionally using frozen-thawed spermatozoa obtained from MESA had been reported to be successful. With minimal invasiveness, intentionally cryopreserved PESA specimens and intracytoplasmic sperm injection (ICSI) were carried out in two cases. CASES: Two cases of irreparable obstructive azoospermia received PESA, and the spermatozoa were cryopreserved intentionally. Successful ICSI was performed later, utilizing frozen-thawed spermatozoa. CONCLUSION: PESA and ICSI are promising methods for these patients. The major advantages are minimal invasiveness and flexibility for further treatment.


Assuntos
Criopreservação , Injeções de Esperma Intracitoplásmicas/métodos , Espermatozoides , Adulto , Feminino , Humanos , Inalação , Masculino , Microcirurgia , Oligospermia/etiologia , Indução da Ovulação/métodos , Contagem de Espermatozoides , Motilidade dos Espermatozoides , Espermatozoides/fisiologia
20.
Zhonghua Yi Xue Za Zhi (Taipei) ; 64(1): 59-63, 2001 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-11310373

RESUMO

Ticlopidine is a commonly prescribed drug in cerebrovascular or cardiovascular diseases. Since the first introduction in 1970's, ticlopidine was shown to be a relatively safe drug. The adverse effects of ticlopidine were mainly bone marrow toxicity and elevation of liver function tests. Ticlopidine-induced hepatitis is rare and only 33 cases were reported in previous English literature. The 33 cases were mostly categorized in cholestatic liver injury; only 2 cases were hepatocellular. In Taiwan, a case of ticlopidine-induced cholestatic hepatitis was ever reported. Herein, we present another rare case of ticlopidine-induced hepatitis in Taiwan with the nature of hepatocellular injury.


Assuntos
Doença Hepática Induzida por Substâncias e Drogas/etiologia , Inibidores da Agregação Plaquetária/efeitos adversos , Ticlopidina/efeitos adversos , Idoso , Alanina Transaminase/sangue , Fosfatase Alcalina/sangue , Humanos , Masculino
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