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OBJECTIVE: Abnormal joint instability contributes to cartilage damage and osteophyte formation. We investigated whether controlling joint instability inhibited chronic synovial membrane inflammation and delayed osteophyte formation and examined the role of transforming growth factor-beta (TGF-ß) signaling in the associated mechanism. DESIGN: Rats (n = 94) underwent anterior cruciate ligament (ACL) transection. Anterior tibial instability was either controlled (CAM group) or allowed to continue (SHAM group). At 2, 4, and 8 weeks after surgery, radiologic, histopathologic, immunohistochemical, immunofluorescent, and enzyme-linked immunosorbent assay examinations were performed to evaluate osteophyte formation and TGF-ß signaling. RESULTS: Joint instability increased cartilage degeneration score and osteophyte formation, and cell hyperplasia and proliferation and synovial thickening were observed in the synovial membrane. Major findings were increased TGF-ß expression and Smad2/3 following TGF-ß phosphorylation in synovial membarene, articular cartilage, and the posterior tibial growth plate (TGF-ß expression using ELISA: 4 weeks; P = 0.009, 95% CI [260.1-1340.0]) (p-Smad2/3 expression density: 4 weeks; P = 0.024, 95% CI [1.67-18.27], 8 weeks; P = 0.034, 95% CI [1.25-25.34]). However, bone morphogenetic protein (BMP)-2 and Smad1/5/8 levels were not difference between the SHAM model and the CAM model. CONCLUSIONS: This study showed that the difference between anterior tibial instability caused a change in the expression level of TGF in the posterior tibia and synovial membrane, and the reaction might be consequently involved in osteophyte formation.
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Lesões do Ligamento Cruzado Anterior/cirurgia , Instabilidade Articular/cirurgia , Articulação do Joelho/cirurgia , Osteófito/diagnóstico por imagem , Osteófito/patologia , Fator de Crescimento Transformador beta/metabolismo , Animais , Lesões do Ligamento Cruzado Anterior/diagnóstico por imagem , Lesões do Ligamento Cruzado Anterior/patologia , Proteína Morfogenética Óssea 2/metabolismo , Cartilagem Articular/metabolismo , Cartilagem Articular/patologia , Proliferação de Células , Lâmina de Crescimento/metabolismo , Inflamação/patologia , Instabilidade Articular/diagnóstico por imagem , Instabilidade Articular/patologia , Articulação do Joelho/diagnóstico por imagem , Modelos Animais , Fosforilação , Distribuição Aleatória , Ratos Wistar , Proteína Smad2/metabolismo , Proteína Smad3/metabolismo , Técnicas de Sutura , Membrana Sinovial/metabolismo , Membrana Sinovial/patologiaRESUMO
Chronic active Epstein-Barr virus infection (CAEBV) is characterized by chronic infectious mononucleosis-like symptoms. We report a very rare case with autoimmune hepatitis (AIH) complicated by CAEBV. A 50-year-old woman with systemic lupus erythematosus (SLE) complicated by AIH began to suffer from acute respiratory failure and her clinical symptoms improved rapidly in response to steroid treatment. However, during the gradual tapering of the steroid dose, a steady increase of the serum hepatobiliary enzyme levels subsequently was observed and the patient began to have continuous fever. Moreover, upper gastrointestinal endoscopy revealed multiple intractable gastric ulcers. When EBER-ISH was performed on liver biopsy and gastric mucosal biopsy specimens, EBER-positive lymphocytes were observed. When peripheral blood was examined, 2.1 × 10(6) copies/µg of EBV-DNA were observed in the CD4-positive T cells, confirming the diagnosis of CAEBV. A cooling therapy was started by steroid and cyclosporine. Thereafter, despite the start of CHOP therapy, she developed a malignant lymphoma (PTCL-NOS) and died of hepatic failure. When treatment-resistant AIH patients are encountered, not only AIH exacerbation but also CAEBV should be considered in the differential diagnosis.
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Infecções por Vírus Epstein-Barr/complicações , Infecções por Vírus Epstein-Barr/diagnóstico , Hepatite Autoimune/diagnóstico , Lúpus Eritematoso Sistêmico/complicações , Doença Crônica , Diagnóstico Diferencial , Progressão da Doença , Feminino , Humanos , Pessoa de Meia-IdadeRESUMO
The present study evaluated and compared the bond strength between zirconia and facing composite resin using different surface conditioning methods before and after thermocycling. Four primers, three opaque resins, and two facing composite resins were used, and 10 surface treatment procedures were conducted. The bond strength was measured before and after 4,000 cycles of thermocycling. The mean values of each group were statistically analyzed using one-way analysis of variance (ANOVA). The bond strengths of facing composite resins to zirconia after various treatments varied depending on the primers, opaque resins, body resins, and thermocycling. The application of primers and opaque resins to the zirconia surface after sandblasting is expected to yield strong bond strength of the facing composite resin (Estenia CG&B) even after thermocycling.
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Resinas Compostas , Coroas , Colagem Dentária , Corrosão Dentária/métodos , Porcelana Dentária , Ítrio , Zircônio , Resinas Compostas/química , Análise do Estresse Dentário , Temperatura Alta , Teste de Materiais , Cimentos de Resina/química , Propriedades de SuperfícieAssuntos
Epiderme/patologia , Penfigoide Bolhoso/complicações , Penfigoide Bolhoso/patologia , Psoríase/complicações , Psoríase/patologia , Idoso , ATPases Transportadoras de Cálcio , Epiderme/fisiologia , Feminino , Humanos , Mutação , Pênfigo Familiar Benigno/patologia , Regeneração , ATPases Transportadoras de Cálcio do Retículo SarcoplasmáticoRESUMO
The purpose of this study is to measure and compare the retentive force of zirconia-based all-ceramic crowns cemented on zirconia abutments using five provisional luting agents. In addition, the effect of sandblasting and thermocycling on the retentive force was evaluated. Two hundred zirconia abutments and copings were fabricated (Procera system; Nobel Biocare) and divided into five groups. Hy bond temporary cement hard (Hard), Hy bond temporary cement soft (Soft), experimental temporary cement (New), Tempbond NE (Temp) and Freegenool temporary pack (Pack) were used according to the manufacturers' instructions. Each group was divided into two groups, one with and one without sandblasting. Furthermore, thermocycling up to 2000 cycles was conducted on half of each group. After 24 h and thermocycling, the retentive force was measured using a universal testing machine. The data were subjected to analysis of variance, and comparisons of the means were performed with a Games-Howell test at a level of 95%. As a result, Hard showed the highest retentive force, sandblasting was effective for improving the durability, and no effect of sandblasting was detected in the others. New showed stability of the retentive force even after thermocycling. The retentive force of Temp and Pack decreased significantly after thermocycling even with sandblasting. The retentive forces were different from the provisional cement and sandblasting, and Temp and Pack may not be appropriate for the retention of single-tooth zirconia abutments and coping restorations.
Assuntos
Coroas , Dente Suporte , Colagem Dentária/métodos , Cimentos Dentários/química , Implantes Dentários para Um Único Dente , Retenção em Prótese Dentária , Abrasão Dental por Ar , Análise de Variância , Cimentação/métodos , Planejamento de Prótese Dentária , Restauração Dentária Temporária , Análise do Estresse Dentário , Humanos , Propriedades de Superfície , Óxido de Zinco/química , Cimento de Fosfato de Zinco/química , ZircônioRESUMO
Methods to control the dynamics of coupled oscillators have been developed owing to various medical and technological demands. In this study, we develop a method to control coupled oscillators in which the coupling function expressed in a phase model is regulated by the multilinear feedback. The present method has wide applicability because we do not need to measure an individual output from each oscillator, but only measure the sum of the outputs from all the oscillators. Moreover, it allows us to easily control the coupling function up to higher harmonics. The validity of the present method is confirmed through a simulation.
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BACKGROUND: The clinical implications of evaluating C-terminal atrial natriuretic peptide (ANP) concentration in cats are still controversial. HYPOTHESIS: The objective of this study was to investigate the relationship between plasma C-terminal ANP concentration and left atrial pressure (LAP) in healthy cats with volume overload (study 1), and to compare plasma C-terminal ANP in normal cats and cats with cardiomyopathy (study 2). ANIMALS: Five healthy adult cats were used in study 1, and clinically healthy cats (n=8) and cats with cardiomyopathy (n=14) were used in study 2. METHODS: In study 1, cats were anesthetized and given acetated Ringer's solution (100 mL/kg/h for 60 minute) via the cephalic vein. Hemodynamic measurements and blood samples, collected from the jugular vein, were performed at 10-min intervals. In study 2, blood samples from normal cats and cats with cardiomyopathy were collected from the cephalic vein. The plasma C-terminal ANP concentration was determined by radioimmunoassay for human alpha-ANP. RESULTS: In study 1, volume overload significantly increased the C-terminal ANP concentration and LAP from baseline. The C-terminal ANP concentration was strongly correlated with the mean LAP. In study 2, age, E wave velocity, and the ratios of the left atrium to aorta were significantly higher in the cats with cardiomyopathy compared with the normal cats. The C-terminal ANP concentration was significantly higher in the cats with cardiomyopathy compared with the normal cats. CONCLUSIONS AND CLINICAL IMPORTANCE: Our results suggest that the measurement of plasma C-terminal ANP in cats may provide additional information for the diagnosis of heart disease.
Assuntos
Fator Natriurético Atrial/sangue , Doenças do Gato/sangue , Cardiopatias/veterinária , Animais , Estudos de Casos e Controles , Doenças do Gato/fisiopatologia , Gatos , Feminino , Cardiopatias/sangue , Cardiopatias/fisiopatologia , Hemodinâmica , MasculinoRESUMO
BACKGROUND: In this study we present our new surgical procedure, laparoendoscopic single-site surgery plus 1 for donor nephrectomy (LESS+1-DN), which shortens warm ischemic time (WIT) and improves surgical outcomes. METHODS: From January 2013 to February 2017, 15 patients who underwent LESS-DN and 41 patients who underwent LESS+1-DN at our institution were evaluated retrospectively. Patients were divided into 3 groups: group A, 15 cases of LESS-DN; group B, the first 15 patients who underwent LESS+1-DN; and group C, 26 patients who underwent subsequent LESS+1-DN. To reduce WIT, we clearly defined the roles of the surgeon and first assistant in the 26 subsequent LESS+1-DN cases. The surgeon dissected the renal pedicle and harvested the kidney graft using a recovery bag and the first assistant held the recovery bag. RESULTS: The mean operative time in group C (213.7 minutes) was significantly shorter than that in groups A (253.3 minutes) and B (253.8 minutes). The WIT in group C (195.2 seconds) was significantly shorter than that in groups A (389.8 seconds) and B (313.2 seconds). Open conversion was required in 1 case in group A. None of the donors required conversion to open surgery and no perioperative complications occurred in groups B and C. Linear regression analysis of the LESS+1-DN operative times and consecutive case numbers demonstrated a shallow learning curve (R2 = 0.392, P < .05). CONCLUSION: Our new procedure that divides the roles of the operator and the first assistant contributed significantly to a shortening of WIT. Dividing roles can facilitate a safer laparoscopic donor nephrectomy.
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Transplante de Rim/métodos , Nefrectomia/métodos , Coleta de Tecidos e Órgãos/métodos , Isquemia Quente/métodos , Adulto , Idoso , Conversão para Cirurgia Aberta/estatística & dados numéricos , Feminino , Humanos , Laparoscopia/métodos , Curva de Aprendizado , Tempo de Internação , Doadores Vivos , Masculino , Pessoa de Meia-Idade , Duração da Cirurgia , Estudos RetrospectivosRESUMO
The density oscillator is a simple system that exhibits self-sustained oscillation. It alternately exhibits up and down flow through a pipe which connects two containers filled with fluids of different densities. However, the mechanism of the flow reversal has not yet been fully understood. From the detailed measurements, we have found that flow reversal begins with an intrusion of fluid, which is followed by rapid growth. This process is definitely sensitive to the viscosities of the fluids, and as a consequence, the critical heights leading to flow reversal are clearly viscosity dependent. These experimental results are explained by a simple model, derived by considering forces acting on a unit volume element located at the tip of the intrusion. Using this model, we can successfully explain the mechanism of flow reversal, which is the most essential process in a density oscillator.
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Deep brain stimulation (DBS) of the thalamus (Vo/Vim) has become popular as a means of controlling involuntary movements, including post-stroke movement disorders. We have also found that post-stroke movement disorders and motor weakness can sometimes be controlled by motor cortex stimulation (MCS). In some forms of movement disorders, motor dysfunction becomes evident only when patients intend to move their body. We have developed an on-demand type stimulation system which triggers stimulation by detecting intrinsic signals of intention to move. Such a system represents feed-forward control (FFC) of involuntary movements. We report here our experience of DBS and MCS for controlling post-stroke movement disorders, and discuss the value of FFC. Excellent control of post-stroke movement disorders was achieved by conventional DBS and/or MCS in 20 of 28 patients with hemichoreoathetosis, hemiballism tremor, and motor weakness. FFC was tested in 6 patients who demonstrated excellent control of post-stroke postural tremor or motor weakness by conventional DBS or MCS. The on-demand stimulation provided satisfactory FFC in 4 of 4 patients with postural tremor and 2 of 2 patients with motor weakness, when the activity of muscles involved in posturing or intention to move was fed into the system. These findings justify further clinical studies on DBS and MCS in patients with post-stroke movement disorders. The on-demand type stimulation system may also be useful for overcoming various post-stroke movement disorders.
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Estimulação Encefálica Profunda , Transtornos dos Movimentos/etiologia , Transtornos dos Movimentos/cirurgia , Acidente Vascular Cerebral/fisiopatologia , Lateralidade Funcional , Humanos , Córtex Motor , Tálamo , Resultado do Tratamento , Tremor/etiologia , Tremor/cirurgiaRESUMO
When microelectrode recording of single cell activity is employed for targeting the subthalamic nucleus (STN), multiple sampling of single cells is needed to determine whether the electrode has passed through the ventral boundaries of the STN. In contrast, stepwise recording of multiple cell activities by a semimicroelectrode reveals robust changes in such activities at the dorsal and ventral boundaries. We attempted to quantify changes in multiple cell activities by computing multiple-cell spike density (MSD). We analyzed MSD in 60 sides of 30 patients with Parkinson's disease. Neural noise level was defined as the lowest cut-off level at which neural noise is separated from larger amplitude spikes. MSD was analyzed at cut-off levels ranging from 1.2 to 2.0-fold the neural noise level in the white matter in each trajectory. Both the dorsal and ventral boundaries were clearly identified by an increase and a decrease (p < 0.0001) in MSD, respectively, in all the 60 sides. The cut-off level of 1.2-fold showed the clearest change in MSD between the STN and the pars reticulata of substantia nigra. MSD analysis by semimicroelectrode recording represents the most practical means of identifying the boundaries of STN.
Assuntos
Estimulação Encefálica Profunda , Doença de Parkinson/cirurgia , Núcleo Subtalâmico/anatomia & histologia , Mapeamento Encefálico , Humanos , Neurônios/fisiologia , Doença de Parkinson/patologia , Núcleo Subtalâmico/fisiopatologiaRESUMO
INTRODUCTION: The term "camptocormia" describes a forward-flexed posture. It is a condition characterized by severe frontal flexion of the trunk. Recently, camptocormia has been regarded as a form of abdominal segmental dystonia. Deep brain stimulation (DBS) is a promising therapeutic approach to various types of movement disorders. The authors report the neurological effects of DBS to the bilateral globus pallidum (GPi) in three cases of disabling camptocormia. METHODS: Of the 36 patients with dystonia, three had symptoms similar to that of camptocormia, and all of these patients underwent GPi-DBS. The site of DBS electrode placement was verified by magnetic resonance imaging (MRI). The Burke Fahn and Marsden dystonia rating scale (BFMDRS) was employed to evaluate the severity of dystonic symptoms preoperatively and postoperatively. RESULTS: Significant functional improvement following GPi-DBS was noted in the majority of dystonia cases. At a follow-up observation after more than six months, the overall improvement rate was 71.2 +/- 27.0%, in all dystonia cases who underwent the GPi-DBS. In contrast, the improvement rate of the three camptocormia cases was 92.2 +/- 5.3%. It was confirmed that the improvement rate for camptocormia was much higher than for other types of dystonia. CONCLUSION: According to our experience, a patient with a forward-bent dystonic posture indicative of camptocormia is a good candidate for GPi-DBS. The findings of this study add further support to GPi-DBS as an effective treatment for dystonia, and provide the information on predictors of a good outcome.
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Estimulação Encefálica Profunda , Globo Pálido/cirurgia , Transtornos dos Movimentos/cirurgia , Humanos , Masculino , Pessoa de Meia-Idade , Postura , Estudos RetrospectivosRESUMO
We have used a rat glutathione S-transferase P (GST-P) complementary DNA as a probe to screen a human placenta complementary DNA library constructed in the lambda gt11 vector. One of the positive clones contained the complete coding region (630 base pair) and the entire 3'-noncoding region (78 base pair) of the putative human glutathione S-transferase pi (GST-pi) subunit mRNA. From the nucleotide sequence we deduced the complete amino acid sequence of the GST-pi subunit. It contained 209 amino acids with the relative molecular mass of Mr 23,224. Comparison of the amino acid sequences between GST-pi and GST-P subunits suggests that they are the corresponding enzymes in these species. GST-pi and GST-P both consist of 209 amino acids and differ in only 30 amino acids (85.6% homology). The difference in amino acid composition can explain the large difference in isoelectric point between GST-pi subunit (pI 5.5) and GST-P subunit (pI 6.9). The expression of GST-pi mRNA in some normal and cancerous tissues, including some hepatoma cell lines, hepatoma, and colon carcinoma specimens was determined using complementary DNA as a probe. The results indicate that the mode of the expression of GST-pi in humans is different from that of GST-P in rats.
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Glutationa Transferase/genética , RNA Mensageiro/análise , Animais , Sequência de Bases , DNA/análise , Feminino , Glutationa Transferase/análise , Humanos , Fígado/enzimologia , Masculino , Camundongos , Dados de Sequência Molecular , Neoplasias/enzimologia , Placenta/enzimologia , Fatores SexuaisRESUMO
We conducted a comparative case-control analysis of stomach cancer and atrophic gastritis involving 427 cases with stomach cancer, 1414 cases with atrophic gastritis, and 3014 control subjects based on a questionnaire survey conducted for the subjects who received gastroscopic examination at Aichi Cancer Center Hospital from April 1985 to March 1989. The risk of atrophic gastritis in both males and females was not associated with any environmental factors. The risk of stomach cancer compared with the control subjects was positively associated with an intake of salted fish guts or cod roe [relative risk (RR) = 1.52, 95% confidence interval (CI) = 1.08-2.15] and smoking (RR for 20 or more cigarettes per day = 2.84; 95% CI = 1.79-4.51) and inversely associated with Western-style breakfast (RR = 0.68; 95% CI = 0.48-0.96) in males. Additionally, the risk of stomach cancer was inversely associated with a daily intake of raw vegetables (RR = 0.56; 95% CI = 0.34-0.94) in males when compared with the patients with atrophic gastritis as controls. Several environmental factors, such as intake of green-yellow vegetables, fruit, and meat, and a family history of stomach cancer, were only associated with intestinal types of cancer in females, whereas a clear difference between diffuse and intestinal types was not observed in males. The results of the present study suggest that risk factors for stomach cancer may be different from those for premalignant lesions.
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Gastrite Atrófica/etiologia , Neoplasias Gástricas/etiologia , Adulto , Idoso , Estudos de Casos e Controles , Dieta , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Fatores de Risco , Fatores SexuaisRESUMO
Brain slices maintained in vitro have been extensively used for studying neuronal synchronization. However, the validity of this approach may be questioned since pharmacological procedures are usually required to elicit spontaneous events similar to the EEG activity recorded in vivo. Here, we report that when superfused with control medium, rat brain slices comprising the entorhinal and perirhinal cortices along with a portion of the basolateral/lateral nuclei of the amygdala can synchronously generate periodic oscillatory activity at 5-11 Hz every 5-30 s. The periodic events: (i) correspond intracellularly to synaptic depolarizations in regularly firing neurons analyzed in the three areas; (ii) have no fixed site of onset; (iii) spread with time lags of 8-20 ms; and (iv) continue to occur asynchronously after their surgical isolation. NMDA receptor antagonism reduced the duration of the oscillatory events, while glutamatergic non-NMDA receptor antagonism abolished them. Activation of mu-opioid receptors, a procedure that hyperpolarizes interneurons thus decreasing GABA release, reversibly decreased the rate of occurrence of periodic oscillatory activity (POA). However, periodic events continued to occur during application of GABA(A) or GABA(B) receptor antagonists as well as in the presence of the cholinergic agent carbachol. We also found that POA was abolished by baclofen and irreversibly reduced by the gap junction decoupler carbenoxolone. These findings demonstrate that parahippocampal networks in a brain slice preparation can generate periodic, synchronous activity under quasi-physiological conditions. These network oscillations (i) reflect the activation of ionotropic glutamatergic and GABAergic receptors, (ii) are contributed by gap-junction interactions, and (iii) are controlled by GABA(B) receptors that are presumably located presynaptically.
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Potenciais de Ação/fisiologia , Relógios Biológicos/fisiologia , Vias Neurais/fisiologia , Neurônios/fisiologia , Técnicas de Cultura de Órgãos/métodos , Giro Para-Hipocampal/fisiologia , Potenciais de Ação/efeitos dos fármacos , Tonsila do Cerebelo/efeitos dos fármacos , Tonsila do Cerebelo/fisiologia , Animais , Relógios Biológicos/efeitos dos fármacos , Agonistas Colinérgicos/farmacologia , Meios de Cultura/farmacologia , Córtex Entorrinal/efeitos dos fármacos , Córtex Entorrinal/fisiologia , Antagonistas de Aminoácidos Excitatórios/farmacologia , Antagonistas GABAérgicos/farmacologia , Junções Comunicantes/efeitos dos fármacos , Junções Comunicantes/metabolismo , Ácido Glutâmico/metabolismo , Masculino , Inibição Neural/efeitos dos fármacos , Inibição Neural/fisiologia , Vias Neurais/efeitos dos fármacos , Neurônios/efeitos dos fármacos , Giro Para-Hipocampal/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley , Tempo de Reação/efeitos dos fármacos , Tempo de Reação/fisiologia , Receptores de GABA/efeitos dos fármacos , Receptores de GABA/metabolismo , Receptores de N-Metil-D-Aspartato/antagonistas & inibidores , Receptores de N-Metil-D-Aspartato/efeitos dos fármacos , Receptores Opioides mu/agonistas , Receptores Opioides mu/metabolismo , Transmissão Sináptica/efeitos dos fármacos , Transmissão Sináptica/fisiologia , Ácido gama-Aminobutírico/metabolismoRESUMO
OBJECTIVE: To investigate the fluctuation in serum levels of anti-cyclic citrullinated peptide antibody (anti-CCP) retrospectively in patients with rheumatoid arthritis (RA). METHODS: Serum levels of anti-CCP were measured retrospectively in 131 patients with RA and 90 patients with non-RA rheumatic diseases using a commercially available kit. All sera were collected from patients during the 22-year period, 1982-2004. To analyze the fluctuation in anti-CCP levels, 17 RA patients were selected on the basis of showing a significantly higher anti-CCP level in a serum sample taken at the first visit (> 80 U/ml), and availability of preserved serum samples that had been taken from each patient at 10 time points. RESULTS: The test gave a sensitivity of 88% (115/131) and a specificity of 81% (73/90). The longitudinal study of 17 RA patients showed that anti-CCP levels were elevated at the first visit in 12 (71%) patients and then decreased gradually, whereas those in the other five (29%) patients fluctuated substantially. In both cases, anti-CCP levels tended to fluctuate in parallel with the erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) level, reflecting the spontaneous aggravation of arthritis and the efficacy of anti-rheumatic drugs. The courses of three representative RA patients are illustrated in detail along with their therapeutic regimens, and these further confirm the correlation of anti-CCP levels with laboratory parameters (ESR and CRP) as well as the activity of arthritis. CONCLUSION: Measurement of serum anti-CCP levels was found to be useful for not only the diagnosis but also the management of RA.
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Anticorpos Antinucleares/sangue , Artrite Reumatoide/sangue , Peptídeos Cíclicos/imunologia , Biomarcadores , Feminino , Humanos , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Kit de Reagentes para Diagnóstico , Estudos Retrospectivos , Sensibilidade e EspecificidadeRESUMO
BACKGROUND AND PURPOSE: We used a rat model of thromboembolic stroke to evaluate whether hypertension increases the incidence of hemorrhage after fibrinolysis with tissue plasminogen activator (tPA). METHODS: In this model, a microclot suspension was injected into the middle cerebral artery territory to induce focal ischemia. Reperfusion was induced in spontaneously hypertensive rats (SHR) by administering tPA (10 mg/kg) intravenously at 2 hours or 6 hours after the onset of thromboembolic focal ischemia. In untreated control rats, saline was administered at 2 hours after ischemia. RESULTS: Hemorrhagic transformation was observed only in rats that received tPA at 6 hours (6 of 8 rats [75%]). Reduction of mean arterial blood pressure from 122+/-3 to 99+/-2 mm Hg with hydralazine, given to SHR for 1 week before ischemia, significantly decreased the incidence of hemorrhage in 2 of 11 rats (18%). tPA reduced infarct volumes, but cotreatment with hydralazine did not result in further protection. CONCLUSIONS: This study demonstrates that in this rat thromboembolic model of stroke, tPA-induced hemorrhage is dependent on blood pressure and that pharmacological reduction of hypertension during fibrinolysis can reduce the risk of hemorrhagic transformation.
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Hemorragia Cerebral/etiologia , Hipertensão/complicações , Trombose Intracraniana/complicações , Acidente Vascular Cerebral/complicações , Terapia Trombolítica , Animais , Velocidade do Fluxo Sanguíneo/efeitos dos fármacos , Gasometria , Pressão Sanguínea/efeitos dos fármacos , Encéfalo/irrigação sanguínea , Encéfalo/patologia , Hemorragia Cerebral/patologia , Hemorragia Cerebral/prevenção & controle , Circulação Cerebrovascular/efeitos dos fármacos , Modelos Animais de Doenças , Esquema de Medicação , Hidralazina/administração & dosagem , Hipertensão/tratamento farmacológico , Incidência , Infarto da Artéria Cerebral Média/complicações , Infarto da Artéria Cerebral Média/patologia , Trombose Intracraniana/tratamento farmacológico , Fluxometria por Laser-Doppler , Masculino , Ratos , Ratos Endogâmicos SHR , Acidente Vascular Cerebral/tratamento farmacológico , Acidente Vascular Cerebral/patologia , Terapia Trombolítica/efeitos adversos , Ativador de Plasminogênio Tecidual/efeitos adversos , Ativador de Plasminogênio Tecidual/uso terapêuticoRESUMO
Tissue type plasminogen activator (tPA) can be effective therapy for embolic stroke by restoring cerebral perfusion. However, a recent experimental study showed that tPA increased infarct size in a mouse model of transient focal ischemia, suggesting a possible adverse effect of tPA on ischemic tissue per se. In this report, the effects of tPA in two rat models of cerebral ischemia were compared. In experiment 1, rats were subjected to focal ischemia via injection of autologous clots into the middle cerebral artery territory. Two hours after clot injection, rats were treated with 10 mg/kg tPA or normal saline. Perfusion-sensitive computed tomography scanning showed that tPA restored cerebral perfusion in this thromboembolic model. Treatment with tPA significantly reduced ischemic lesion volumes measured at 24 hours by >60%. In experiment 2, three groups of rats were subjected to focal ischemia via a mechanical approach in which a silicon-coated filament was used intraluminally to occlude the origin of the middle cerebral artery. In two groups, the filament was withdrawn after 2 hours to allow for reperfusion, and then rats were randomly treated with 10 mg/kg tPA or normal saline. In the third group, rats were not treated and the filament was not withdrawn so that permanent focal ischemia was present. In this experiment, tPA did not significantly alter lesion volumes after 2 hours of transient focal ischemia. In contrast, permanent ischemia significantly increased lesion volumes by 55% compared with transient ischemia. These results indicate that in these rat models of focal cerebral ischemia, tPA did not have detectable negative effects. Other potentially negative effects of tPA may be dependent on choice of animal species and model systems.
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Ataque Isquêmico Transitório/tratamento farmacológico , Ativador de Plasminogênio Tecidual/toxicidade , Ativador de Plasminogênio Tecidual/uso terapêutico , Animais , Lesões das Artérias Carótidas , Artéria Carótida Externa , Modelos Animais de Doenças , Fibrinolíticos/uso terapêutico , Fibrinolíticos/toxicidade , Embolia Intracraniana , Masculino , Camundongos , Artéria Cerebral Média , Ratos , Ratos Sprague-DawleyRESUMO
A neurofibromatosis type-1 (NF1)-related locus on human chromosome 21 has been characterized. A detailed genomic mapping performed by yeast artificial chromosome (YAC) dot-hybridization revealed that the NF1-related locus is close to the sequence-tagged site (STS), D21S329 (G52E12), which is located on the proximal region of 21q11.2. Sequence analysis showed that this locus seemed to be conserved to the NF1 gene only in several partial regions. Two exon-like segments corresponding to exons 8 and 9 of NF1 were found, in addition to two previously found fragments corresponding to exons 7 and 11. Other exon-like segments were not found in the region so far sequenced. Comparing these homologous segments with the NF1 cDNA, a 2-bp deletion appeared in exon 8 of the locus, resulting in the existence of stop codons in all reading frames. In addition, there were no amplified fragments derived from the related locus by reverse transcription-PCR. Thus, our results suggest that the NF1-related locus on chromosome 21 is a nonprocessed pseudogene.
Assuntos
Cromossomos Humanos Par 21 , Genes da Neurofibromatose 1 , Pseudogenes , Animais , Sequência de Bases , Mapeamento Cromossômico , Cricetinae , Humanos , Células Híbridas , Dados de Sequência Molecular , RNA Mensageiro/metabolismo , Células Tumorais CultivadasRESUMO
We have developed an exon-trapping system with a newly constructed trapping vector containing multiple cloning sites (designated pEXT2). The system revealed high sensitivity for trapping a control exon from several hundred kbp of DNA. We have applied the system to the cosmid clones located on human chromosome 21p11-q21, and identified two fragments highly homologous to neurofibromatosis 1 (NF1) gene and a clearly transcribed fragment hybridized with approximately 1.6 kb RNA from human brain and human glioblastoma A172 cell.