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1.
J Neurointerv Surg ; 2024 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-38569885

RESUMO

BACKGROUND: Spinal epidural arteriovenous fistulas (SEDAVFs) are rarely diagnosed vascular malformations that can cause spinal cord compression and congestive myelopathy. METHODS: This is a single-center, retrospective case series of patients with SEDAVFs who underwent observation or treatment at UCLA medical center between 1993 and 2023. RESULTS: Between 1993 and 2023 a total of 26 patients at UCLA were found to have a SEDAVF. The median age at treatment was 59 years (range 4 months to 91 years). Compared with sacral, lumbar, and thoracic SEDAVFs, patients with cervical SEDAVF were younger (41 years vs 63 years, P=0.016) and more likely to be female (66.7% vs 14.3%, P=0.006). Possible triggers for development of SEDAVFs may be prior spinal surgery or trauma (n=4), turning the neck (n=1), lifting a heavy box (n=1), a prolonged period of bending over (n=1), and neurofibromatosis type 1 (n=1). Of the 22 patients treated endovascularly, 18 (82%) were angiographically cured on the first attempt without complications. One patient underwent surgical treatment alone and had a failed surgery on the first attempt, and developed a surgical site infection after the second successful attempt at treatment. Of the 16 patients with adequate clinical follow-up, 11 (69%) demonstrated early improved clinical outcome (eg, improved strength on examination, absent bruit). CONCLUSIONS: SEDAVFs are a rarely diagnosed disease that can be treated effectively and safely with endovascular embolization in most cases. Patients with sacral, lumbar, and thoracic SEDAVFs were older and more often male compared to patients with cervical SEDAVFs.

2.
Radiol Clin North Am ; 61(3): 435-443, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36931760

RESUMO

The cerebral collateral circulation is an increasingly important consideration in the management of acute ischemic stroke and is a key determinant of outcomes. Growing evidence has demonstrated that better collaterals can predict the rate of infarct progression, degree of recanalization, the likelihood of hemorrhagic transformation and various therapeutic opportunities. Collaterals can also identify those unlikely to respond to reperfusion therapies, helping to optimize resources. More randomized trials are needed to evaluate the risks and benefits of endovascular reperfusion with consideration of collateral status. This reviews our current understanding of the pathophysiologic mechanisms, effect on outcomes and strategies for improvement of the collateral system.


Assuntos
Isquemia Encefálica , AVC Isquêmico , Acidente Vascular Cerebral , Humanos , Acidente Vascular Cerebral/diagnóstico por imagem , Acidente Vascular Cerebral/terapia , AVC Isquêmico/diagnóstico por imagem , AVC Isquêmico/terapia , Isquemia Encefálica/complicações , Isquemia Encefálica/diagnóstico por imagem , Isquemia Encefálica/terapia , Circulação Colateral/fisiologia
3.
Neurohospitalist ; 13(1): 40-45, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36531842

RESUMO

Background: Intravenous tissue plasminogen activator (IV-tPA) remains part of the guidelines for acute ischemic stroke treatment, yet internal carotid artery occlusions (ICAO) are known to be poorly responsive to IV-tPA. It is unknown whether bridging thrombolysis (BT) is beneficial in such cases. Purpose: We sought to evaluate whether the use of IV-tPA improved overall clinical outcomes in patients undergoing endovascular thrombectomy (EVT) for ICA occlusions. Methods: Data from 1367 consecutive stroke cases treated with EVT from 2012-2019 were prospectively collected from a single center. Univariate and multivariate logistic regression were used to assess the relationship between IV-tPA administration and clinical outcome. Results: 153 patients were found to have carotid terminus and tandem ICAO who received EVT and presented within 4.5h of last seen well. 50% (n = 82) received IV tPA. There were no differences between the groups with respect to age, NIHSS, time to EVT and ASPECTS score. 53% had tandem ICA-MCA occlusions. Rate of recanalization (≥ TICI 2B) and sICH did not significantly differ between the two groups. Regression analysis demonstrated no effect of IV-tPA on modified Rankin Score (mRS) at 90 days and overall mortality. Factors significantly associated with reduced mortality included lower age, lower NIHSS, and better rate of recanalization. Conclusions: There was no significant difference in clinical outcomes in those receiving BT vs. direct EVT for ICAO. For centers with optimal door-to-puncture times, bypassing IV-tPA may expedite recanalization times and potentially yield more favorable outcomes. Patients with higher NIHSS and tandem lesions may have better outcomes with BT.

4.
Annu Int Conf IEEE Eng Med Biol Soc ; 2021: 3787-3790, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34892060

RESUMO

In brain function measurement by fNIRS, reducing the effect of the hemodynamic change on the signal is important. In this study, a depth-selective filter, which is one of the reduction methods, was applied to the brain function measurement and its reduction effect was verified. A Stroop GO/NO-GO task, which is expected to produce a response in the frontal region was used. The experiments showed the effectiveness of reducing the hemodynamic changes with the depth-selective filter. It can be used as a preprocessing tool for estimating the activated region.


Assuntos
Fenômenos Fisiológicos do Sistema Nervoso , Espectroscopia de Luz Próxima ao Infravermelho , Lobo Frontal , Hemodinâmica
7.
Physiol Rep ; 8(2): e14360, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31994353

RESUMO

Most of the filtered glucose is reabsorbed in the early proximal tubule by the sodium-glucose cotransporter SGLT2. The glycosuric effect of the SGLT2 inhibitor ipragliflozin is linked to a diuretic and natriuretic effect that activates compensatory increases in fluid and food intake to stabilize body fluid volume (BFV). However, the compensatory mechanisms that are activated on the level of renal tubules remain unclear. Type 2 diabetic Goto-Kakizaki (GK) rats were treated with vehicle or 0.01% (in diet) ipragliflozin with free access to fluid and food. After 8 weeks, GK rats were placed in metabolic cages for 24-hr. Ipragliflozin decreased body weight, serum glucose and systolic blood pressure, and increased fluid and food intake, urinary glucose and Na+ excretion, urine volume, and renal osmolar clearance, as well as urine vasopressin and solute-free water reabsorption (TcH2O). BFV, measured by bioimpedance spectroscopy, and fluid balance were similar among the two groups. Urine vasopressin in ipragliflozin-treated rats was negatively and positively associated with fluid balance and TcH2O, respectively. Ipragliflozin increased the renal membrane protein expression of SGLT2, aquaporin (AQP) 2 phosphorylated at Ser269 and vasopressin V2 receptor. The expression of SGLT1, GLUT2, AQP1, and AQP2 was similar between the groups. In conclusion, the SGLT2 inhibitor ipragliflozin induced a sustained glucosuria, diuresis, and natriuresis, with compensatory increases in fluid intake and vasopressin-induced TcH2O in proportion to the reduced fluid balance to maintain BFV. These results indicate that the osmotic diuresis induced by SGLT2 inhibition stimulates compensatory fluid intake and renal water reabsorption to maintain BFV.


Assuntos
Líquidos Corporais/metabolismo , Diurese/fisiologia , Osmose/fisiologia , Reabsorção Renal/fisiologia , Inibidores do Transportador 2 de Sódio-Glicose/farmacologia , Vasopressinas/urina , Água/metabolismo , Animais , Compartimentos de Líquidos Corporais/efeitos dos fármacos , Compartimentos de Líquidos Corporais/metabolismo , Líquidos Corporais/efeitos dos fármacos , Diurese/efeitos dos fármacos , Diuréticos Osmóticos/farmacologia , Glucosídeos/farmacologia , Osmose/efeitos dos fármacos , Ratos , Reabsorção Renal/efeitos dos fármacos , Tiofenos/farmacologia
8.
Annu Int Conf IEEE Eng Med Biol Soc ; 2019: 486-489, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31945943

RESUMO

In brain function measurement by near-infrared spectroscopy, reduction of signal fluctuation caused by the superficial blood flow is necessary. We proposed an equilateral-triangle-type sensor arrangement for cancelling superficial blood flow using short-distance detectors placed at the center of the triangle. We applied the independent components analysis (ICA) for this equilateral triangle configuration to improve the correction effect. We measured the change in blood volume caused by the motion artifacts according to the posture change and analyzed the correction effect of the ICA. It is shown that the ICA is more effective than simple subtraction and has small dependence on the measurement conditions and is applicable to this equilateral triangle configuration.


Assuntos
Espectroscopia de Luz Próxima ao Infravermelho , Algoritmos , Artefatos , Encéfalo , Hemodinâmica
9.
Annu Int Conf IEEE Eng Med Biol Soc ; 2018: 3302-3305, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30441095

RESUMO

To estimate brain activity, it is important to improve the accuracy of brain function measurements by using near-infrared spectroscopy. The detection of signals is vital for correcting any disturbances or changes in the skin blood volume. We developed a cancellation method for brain probes placed on the scalp in the configuration of an equilateral triangle. In this configuration, 12 types of target signals were detected between the vertices, and 6 types of correction signals were detected between the vertices and the center of the triangle. We measured the changes in the blood volume resulting from the specific postural changes of the subject and applied the correction method using three calculation methods. The measured results showed that the correction signals were effective in reducing the disturbances. The correction was based on the cross-correlation coefficient and the amplitude ratio of signals.


Assuntos
Encéfalo , Espectroscopia de Luz Próxima ao Infravermelho , Volume Sanguíneo , Mapeamento Encefálico , Couro Cabeludo
10.
Am J Physiol Renal Physiol ; 315(3): F653-F664, 2018 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-29790389

RESUMO

The chronic intrinsic diuretic and natriuretic tone of sodium-glucose cotransporter 2 (SGLT2) inhibitors is incompletely understood because their effect on body fluid volume (BFV) has not been fully evaluated and because they often increase food and fluid intake at the same time. Here we first compared the effect of the SGLT2 inhibitor ipragliflozin (Ipra, 0.01% in diet for 8 wk) and vehicle (Veh) in Spontaneously Diabetic Torii rat, a nonobese type 2 diabetic model, and nondiabetic Sprague-Dawley rats. In nondiabetic rats, Ipra increased urinary excretion of Na+ (UNaV) and fluid (UV) associated with increased food and fluid intake. Diabetes increased these four parameters, but Ipra had no further effect, probably because of its antihyperglycemic effect, such that glucosuria and, as a consequence, food and fluid intake were unchanged. Fluid balance and BFV, determined by bioimpedance spectroscopy, were similar among the four groups. To study the impact of food and fluid intake, nondiabetic rats were treated for 7 days with Veh, Ipra, or Ipra+pair feeding+pair drinking (Pair-Ipra). Pair-Ipra maintained a small increase in UV and UNaV versus Veh despite similar food and fluid intake. Pair-Ipra induced a negative fluid balance and decreased BFV, whereas Ipra or Veh had no significant effect compared with basal values. In conclusion, SGLT2 inhibition induces a sustained diuretic and natriuretic tone. Homeostatic mechanisms are activated to stabilize BFV, including compensatory increases in fluid and food intake.


Assuntos
Composição Corporal/efeitos dos fármacos , Diabetes Mellitus Tipo 2/tratamento farmacológico , Diurese/efeitos dos fármacos , Glucosídeos/toxicidade , Natriurese/efeitos dos fármacos , Inibidores do Transportador 2 de Sódio-Glicose/toxicidade , Transportador 2 de Glucose-Sódio/metabolismo , Sódio/urina , Tiofenos/toxicidade , Animais , Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/fisiopatologia , Diabetes Mellitus Tipo 2/urina , Modelos Animais de Doenças , Ingestão de Líquidos , Ingestão de Alimentos , Canais Epiteliais de Sódio/metabolismo , Masculino , Ratos Sprague-Dawley , Transportador 1 de Glucose-Sódio/metabolismo , Trocador 3 de Sódio-Hidrogênio/metabolismo , Fatores de Tempo , Equilíbrio Hidroeletrolítico/efeitos dos fármacos
12.
J Neurointerv Surg ; 9(7): 664-668, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27334979

RESUMO

BACKGROUND: The optimal management strategy for unruptured cerebral arteriovenous malformations (AVMs) is controversial since the ARUBA trial (A Randomized trial of Unruptured Brain AVMs). An accurate understanding of the morbidity associated with AVM hemorrhages may help clinicians to formulate the best treatment strategy for unruptured AVMs. OBJECTIVE: To determine the morbidity associated with initial cerebral AVM rupture in patients presenting to tertiary medical centers. METHODS: Retrospective chart reviews from three tertiary academic medical centers were performed for the period between 2008 and 2014. All patients admitted with intracranial hemorrhage due to untreated AVMs were included in this study. Patient-specific variables, including demographics, imaging characteristics, neurologic examination results, and clinical outcome, were analyzed and recorded. RESULTS: 101 Patients met the inclusion criteria. Admission National Institutes of Health Stroke Scale (NIHSS) scores were 0, 1-9, and ≥10 in 26%, 29%, and 45% of patients, respectively. Hematoma locations were subarachnoid, intraventricular, intraparenchymal, and combined in 5%, 11%, 32%, and 52% of patients, respectively. Deep venous drainage was present in 43% of AVMs; AVM-associated aneurysms were present in 44% of patients. Emergent hematoma evacuations were performed in 37% of patients and 8% of patients died while in hospital. At discharge, of those who survived, NIHSS scores of ≥1 and ≥10 were found in 69% and 23%, respectively. At the 90-day follow-up, 34% had a modified Rankin Scale (mRS) score >2. Patients with admission NIHSS score ≥10 had significantly higher rates of midline shift, surgical hematoma evacuation, and follow-up mRS ≥3 (p<0.05). CONCLUSIONS: The morbidity associated with cerebral AVM rupture appeared to be higher in our study than previously reported. Morbidity from AVM rupture should be considered as an important factor, together with variables such as risk of AVM rupture and procedural risk, in determining the optimal treatment strategy for unruptured cerebral AVMs.


Assuntos
Fístula Arteriovenosa/diagnóstico , Fístula Arteriovenosa/epidemiologia , Malformações Arteriovenosas Intracranianas/diagnóstico , Malformações Arteriovenosas Intracranianas/epidemiologia , Hemorragias Intracranianas/diagnóstico , Hemorragias Intracranianas/epidemiologia , Adulto , Idoso , Fístula Arteriovenosa/terapia , Feminino , Seguimentos , Humanos , Malformações Arteriovenosas Intracranianas/terapia , Hemorragias Intracranianas/terapia , Masculino , Pessoa de Meia-Idade , Morbidade , Exame Neurológico , Ensaios Clínicos Controlados Aleatórios como Assunto/métodos , Estudos Retrospectivos
13.
Brain Dev ; 38(1): 163-6, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26403311

RESUMO

Here, we report a 5-year-old girl with Guillain-Barré syndrome who presented with a chief complaint of pain in the extremities, which was followed by neck stiffness. Bladder dysfunction was found, which required catheterization. Magnetic resonance imaging revealed marked enhancement of the nerve roots in the cauda equina on T1-weighted imaging after gadolinium injection, and nerve conduction studies led to a diagnosis of Guillain-Barré syndrome. Her symptoms improved after intravenous immunoglobulin therapy, but her neck stiffness remained 16 days after admission. Four weeks after admission, she could walk without support. As patients with signs of meningeal irritation may be diagnosed with other diseases, such as meningitis, it is important to recognize atypical cases of pediatric Guillain-Barré syndrome to achieve early diagnosis and treatment.


Assuntos
Síndrome de Guillain-Barré/diagnóstico , Síndrome de Guillain-Barré/patologia , Meninges/patologia , Medula Espinal/patologia , Pré-Escolar , Diagnóstico Diferencial , Diagnóstico Precoce , Feminino , Síndrome de Guillain-Barré/fisiopatologia , Síndrome de Guillain-Barré/terapia , Humanos , Imunoglobulinas Intravenosas/uso terapêutico , Fatores Imunológicos/uso terapêutico , Imageamento por Ressonância Magnética
14.
Alzheimer Dis Assoc Disord ; 29(4): 312-6, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25350550

RESUMO

Dementia is an important risk factor for delirium, but the optimal strategy for incorporating cognitive impairment into delirium risk assessment at the time of hospital admission is unknown. We compared 2 informant-based screening tools for dementia and mild cognitive impairment [AD8 and D=(MC)] to the Mini Mental State Examination (MMSE) and Mini-cog in predicting hospital-acquired delirium. This prospective cohort study at an academic medical center consisted of 162 medical inpatients over age 50 years without delirium upon admission. Each participant was evaluated using the MMSE, Mini-cog, AD8, and D=(MC) upon admission and was assessed daily for delirium. An MMSE≤24 carried a 5.5 [95% confidence intervals (CI), 2.7-11.1] relative risk for delirium, whereas cognitive impairment detected by the Mini-cog, D=(MC), or AD8 carried a 2-fold risk. Adding the D=(MC) to the MMSE increased the sensitivity for predicting delirium from 52% (range, 32% to 73%) for the MMSE alone to 65% (range, 46% to 85%) if either test was positive. If both were positive, specificity was maximized at 97% (range, 94% to 100%), but sensitivity was 17% (range, 2% to 33%). The MMSE and Mini-cog identify a large proportion of patients at risk for hospital-acquired delirium, but the combination of performance-based and an informant-based screens may maximize specificity and sensitivity.


Assuntos
Cuidadores/psicologia , Delírio/diagnóstico , Delírio/psicologia , Demência/diagnóstico , Demência/psicologia , Hospitalização/tendências , Idoso , Idoso de 80 Anos ou mais , Estudos de Coortes , Feminino , Seguimentos , Humanos , Masculino , Programas de Rastreamento/métodos , Pessoa de Meia-Idade , Testes Neuropsicológicos , Valor Preditivo dos Testes , Estudos Prospectivos
15.
J Hosp Med ; 8(9): 493-9, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23922253

RESUMO

BACKGROUND: Risk factors for delirium are well-described, yet there is no widely used tool to predict the development of delirium upon admission in hospitalized medical patients. OBJECTIVE: To develop and validate a tool to predict the likelihood of developing delirium during hospitalization. DESIGN: Prospective cohort study with derivation (May 2010-November 2010) and validation (October 2011-March 2012) cohorts. SETTING: Two academic medical centers and 1 Veterans Affairs medical center. PATIENTS: Consecutive medical inpatients (209 in the derivation and 165 in the validation cohort) over age 50 years without delirium at the time of admission. MEASUREMENTS: Delirium assessed daily for up to 6 days using the Confusion Assessment Method. RESULTS: The AWOL prediction rule was derived by assigning 1 point to each of 4 items assessed upon enrollment that were independently associated with the development of delirium (Age ≥ 80 years, failure to spell "World" backward, disOrientation to place, and higher nurse-rated iLlness severity). Higher scores were associated with higher rates of delirium in the derivation and validation cohorts (P for trend < 0.001 and 0.025, respectively). Rates of delirium according to score in the combined population were: 0(1/50, 2%), 1(5/141, 4%), 2(15/107, 14%), 3(10/50, 20%), and 4(7/11, 64%) (P for trend < 0.001). Area under the receiver operating characteristic curve for the derivation and validation cohorts was 0.81 (0.73-0.90) and 0.69 (0.54-0.83) respectively. CONCLUSIONS: The AWOL prediction rule characterizes medical patients' risk for delirium at the time of hospital admission and could be used for clinical stratification and in trials of delirium prevention.


Assuntos
Delírio/diagnóstico , Delírio/psicologia , Escalas de Graduação Psiquiátrica/normas , Idoso , Idoso de 80 Anos ou mais , Estudos de Coortes , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Estudos Prospectivos , Fatores de Risco
16.
Yakugaku Zasshi ; 130(9): 1197-205, 2010 Sep.
Artigo em Japonês | MEDLINE | ID: mdl-20823677

RESUMO

Recently, certification systems for Board-Certified Psychiatric Pharmacy Specialists (BCPPS) and Board-Certified Pharmacists in Psychiatric Pharmacy (BCPPP) were established by the Japanese Society of Hospital Pharmacists (JSHP) in 2008, to meet the increasing needs for specialists in psychiatric pharmacy. However, there was no report on the background and opinion of pharmacists who have intention to take the BCPPS or BCPPP and/or seminar programs for BCPPS or BCPPP. The Chiba Society of Hospital Pharmacists has started to provide a seminar program certified by the JSHP to study psychiatry for pharmacists and also investigated the participants' background, demand for the program, and issues in taking the BCPPS or BCPPP using questionnaires. We found that many participants wanted lectures to obtain information on issues they face in routine work as well as for certification testing. For many participants, satisfying the requirements for applying for the BCPPS or BCPPP was one of the most important issues in receiving the qualifications. We found that over 40% of participants working at community pharmacies intended to take the BCPPS or BCPPP, although working experience at a community pharmacy does not entitle them to apply for the BCPPS or BCPPP. The intention of community pharmacists indicates that discussion of the requirements for BCPPS or BCPPP certification systems is necessary to improve psychiatric community care. We will plan a practical seminar program with feedback from this investigation.


Assuntos
Certificação , Educação Continuada em Farmácia/métodos , Farmacêuticos/normas , Psiquiatria/educação , Sociedades Farmacêuticas , Conselhos de Especialidade Profissional , Inquéritos e Questionários , Currículo , Humanos , Japão
17.
J Pharm Pharm Sci ; 13(2): 254-62, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20816010

RESUMO

PURPOSE: The purpose of our study was to optimize lipid-lowering therapy in patients undergoing coronary revascularization and to determine whether the percentage change in low-density lipoprotein-cholesterol (LDL-C) level in the 3 months after coronary revascularization could be used as a predictor of the time to recurrence of coronary artery disease (CAD). METHODS: Biochemical values of patients undergoing lipid-lowering therapy after receiving coronary revascularization at the Nippon Medical School Chiba Hokusoh Hospital, Japan, were retrospectively investigated. Recurrence of a cardiovascular event (CVE) was defined by death, myocardial infarction, or angina caused by coronary revascularization more than 3 months after the first event. RESULTS: Of 171 patients under secondary preventive care who had at least one recurrence of a CVE, 75 showed evidence of objective stenotic lesions on coronary angiography. Among these 75 patients, exclusion of those in whom coronary revascularization had not been performed at disease onset, balloon dilatation had been used, serum lipid levels had not been measured, or coronary revascularization had been applied to restenosis left 44 patients suitable for inclusion in the study group. Although the mean value of high density lipoprotein-cholesterol did not change in the 3 months after coronary revascularization, that of (LDL-C) significantly decreased. A significant positive correlation was identified between % decrease in LDL-C and number of days to CVE recurrence. The average LDL-C value (102.8+/-21.7 mg/dL) in the group of patients with no recurrence within 5 years was significantly lower than that (135.3+/-46.1 mg/dL) in the recurrence group (P = 0.0088). The % of patients achieving the LDL-C target level (non-recurrence group vs. recurrence group: 50.0% vs. 16.7%; P = 0.032) and the % decrease in LDL-C (31.0%+/-12.6% vs. 9.6+/-21.0%, P = 0.0012) were significantly greater in the non-recurrence group than in the recurrence group. CONCLUSIONS: From our present study, a decrease in LDL-C 3 months after revascularization surgery reduces the rate of CVE relapse. The % LDL-C decrease could serve as a useful predictor of CVE recurrence, in addition to LDL-C values and achievement of the LDL-C target level.


Assuntos
Doenças Cardiovasculares/prevenção & controle , LDL-Colesterol/efeitos dos fármacos , Doença da Artéria Coronariana/terapia , Inibidores de Hidroximetilglutaril-CoA Redutases/uso terapêutico , Idoso , Doenças Cardiovasculares/etiologia , LDL-Colesterol/sangue , Angiografia Coronária , Doença da Artéria Coronariana/fisiopatologia , Estenose Coronária/fisiopatologia , Estenose Coronária/terapia , Estudos Transversais , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Fatores de Risco , Prevenção Secundária , Fatores de Tempo
18.
Genetics ; 183(2): 517-27, 2009 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-19620394

RESUMO

Rheb, a Ras-like small GTPase conserved from human to yeast, controls Tor kinase and plays a central role in the regulation of cell growth depending on extracellular conditions. Rhb1 (a fission yeast homolog of Rheb) regulates amino acid uptake as well as response to nitrogen starvation. In this study, we generated two mutants, rhb1-DA4 and rhb1-DA8, and characterized them genetically. The V17A mutation within the G1 box defined for the Ras-like GTPases was responsible for rhb1-DA4 and Q52R I76F within the switch II domain for rhb1-DA8. In fission yeast, two events--the induction of the meiosis-initiating gene mei2+ and cell division without cell growth--are a typical response to nitrogen starvation. Under nitrogen-rich conditions, Rheb stimulates Tor kinase, which, in turn, suppresses the response to nitrogen starvation. While amino acid uptake was prevented by both rhb1-DA4 and rhb1-DA8 in a dominant fashion, the response to nitrogen starvation was prevented only by rhb1-DA4. rhb1-DA8 thereby allowed genetic dissection of the Rheb-dependent signaling cascade. We postulate that the signaling cascade may branch below Rhb1 or Tor2 and regulate the amino acid uptake and response to nitrogen starvation independently.


Assuntos
Proteínas Monoméricas de Ligação ao GTP/genética , Mutação , Nitrogênio/metabolismo , Schizosaccharomyces/genética , Sequência de Aminoácidos , Western Blotting , Divisão Celular/efeitos dos fármacos , Genes Dominantes , Dados de Sequência Molecular , Nitrogênio/farmacologia , Fosfatidilinositol 3-Quinases/genética , Fosfatidilinositol 3-Quinases/metabolismo , Schizosaccharomyces/citologia , Schizosaccharomyces/metabolismo , Proteínas de Schizosaccharomyces pombe/genética , Proteínas de Schizosaccharomyces pombe/metabolismo , Homologia de Sequência de Aminoácidos , Transdução de Sinais/genética , Supressão Genética
20.
Mol Med Rep ; 1(2): 203-9, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-21479398

RESUMO

The rapid outbreak of the highly pathogenic H5N1 avian influenza virus and its transmission to humans have induced world-wide fears of a new influenza pandemic. The most effective method for the reduction of the impact of such a pandemic would be prophylaxis with a safe and effective vaccine, as well as anti-viral materials. In this study, we generated the specific antibodies 'immunoglobulin yolk (IgY)' from ostrich eggs immunized with a full-length glycosylated recombinant H5 protein of the strain H5N1/Vietnam/1203/2004. Using this simple method, abundant specific antibody (about 200 g) against H5 was successfully produced by one female ostrich in a year. The IgY from the immunized ostrich eggs had strong reactivity to the H5N1 virus as well as to H5 proteins. Furthermore, the antibodies strongly inhibited cytopathic effects in MDCK cells and prevented the death of an embryonated chick after a viral inoculation, indicating strong neutralization activity against H5N1 infections. These findings suggest that the neutralization antibody produced by the H5-immunized ostrich is suitable for industrial purposes, such as the development of antibody-binding filters, which can be applied to a mask or to air-conditioners to prevent the influenza pandemic through antigen-antibody reactions. Of note, the mortality rate of chicks inoculated with the H5N1 virus was dramatically decreased with antibody injection. This indicates that ostrich IgY is a potentially effective therapeutic modality for H5N1 infection.

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