Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 18 de 18
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Travel Med Infect Dis ; 60: 102729, 2024 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-38821331

RESUMO

BACKGROUND: Implementing technological solutions to screen for and detect early the most prevalent communicable diseases on cruise ships is contingent on, among others, willingness of passengers to accept use of such solutions. METHOD: We surveyed passenger preferences to record their willingness to accept technological solutions for screening and early detection of communicable diseases on cruise ships. Self-reported sociodemographic characteristics, use of technology and acceptance of solutions were recorded anonymously in paper format. Multiple logistic regression analyses investigated the association of demographic and other characteristics with willingness and barriers/concerns of passengers to endorse proposed solutions. RESULTS: Of a total of 1344 passengers on two successive cruises on board CELESTYAL OLYMPIA, 336 (1 every 4) participated in the survey. The vast majority of passengers (92.3 %, n = 310) agreed with at least one solution. Passengers showed lower levels of acceptance for more personalized solutions, such as use of wearable devices (45.5 %) and monitoring with cameras (64.0 %), whereas they were more receptive to less personally invasive solutions, such as integration of cabins with air purifiers (89.6 %) and air quality sensors (80.4 %). Age, self-employment status, educational level, and fear of contacting a communicable disease were significantly correlated with passengers' willingness to adopt proposed solutions. CONCLUSIONS: To successfully integrate screening and early detection technological solutions in cruise ships, it is imperative that targeted awareness and education interventions are implemented on passengers to strengthen understanding and acceptance of such solutions and assuage concerns around monitoring and handling of personal health data.

2.
Cancers (Basel) ; 16(3)2024 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-38339373

RESUMO

The present study focuses on the development of a methodology for evaluating the safety of MNH systems, through the numerical prediction of the induced temperature rise in superficial skin layers due to eddy currents heating under an alternating magnetic field (AMF). The methodology is supported and validated through experimental measurements of the AMF's distribution, as well as temperature data from the torsos of six patients who participated in a clinical trial study. The simulations involved a computational model of the actual coil, a computational model of the cooling system used for the cooling of the patients during treatment, and a detailed human anatomical model from the Virtual Population family. The numerical predictions exhibit strong agreement with the experimental measurements, and the deviations are below the estimated combined uncertainties, confirming the accuracy of computational modeling. This study highlights the crucial role of simulations for translational medicine and paves the way for personalized treatment planning.

3.
Cancers (Basel) ; 14(22)2022 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-36428577

RESUMO

(1) Background: Lung cancer causes a substantial epidemiological burden in Greece. Yet, no formal national lung cancer screening program has been introduced to date. This study modeled the impact on lung cancer life years (LCLY) of a hypothetical scenario of comprehensive screening for lung cancer with low-dose computed tomography (LDCT) of the high-risk population in Greece, as defined by the US Preventive Services Taskforce, would be screened and linked to care (SLTC) for lung cancer versus the current scenario of background (opportunistic) screening only; (2) Methods: A stochastic model was built to monitor a hypothetical cohort of 100,000 high-risk men and women as they transitioned between health states (without cancer, with cancer, alive, dead) over 5 years. Transition probabilities were based on clinical expert opinion. Cancer cases, cancer-related deaths, and LCLYs lost were modeled in current and hypothetical scenarios. The difference in outcomes between the two scenarios was calculated. 150 iterations of simulation scenarios were conducted for 100,000 persons; (3) Results: Increasing SLTC to a hypothetical 100% of eligible high-risk people in Greece leads to a statistically significant reduction in deaths and in total years lost due to lung cancer, when compared with the current SLTC paradigm. Over 5 years, the model predicted a difference of 339 deaths and 944 lost years between the hypothetical and current scenario. More specifically, the hypothetical scenario led to fewer deaths (−24.56%, p < 0.001) and fewer life years lost (−31.01%, p < 0.001). It also led to a shift to lower-stage cancers at the time of diagnosis; (4) Conclusions: Our study suggests that applying a 100% screening strategy amongst high-risk adults aged 50−80, would result in additional averted deaths and LCLYs gained over 5 years in Greece.

4.
Aging Clin Exp Res ; 34(10): 2473-2481, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35819748

RESUMO

BACKGROUND: Screening and linkage to care (SLTC) for osteoporosis is suboptimal in several settings. In Greece, it is estimated that only up to 8.6% of postmenopausal women are SLTC for osteoporosis, despite having suffered a previous fracture. AIMS: This study aims to estimate the impact of comprehensive screening on future fracture burden amongst post-menopausal women aged 50-74, with one prior osteoporotic fracture, in Greece. METHODS: We developed a cohort stochastic model, based on published epidemiological and clinical data, to assess impact of screening on future fracture burden in two scenarios: a current, assuming an 8.6% background SLTC, and a completely hypothetical, assuming 100% SLTC. RESULTS: Amongst a cohort of 50,000 post-menopausal women aged 50-74, with one prior osteoporotic fracture, applying the hypothetical versus the current scenario would result in a reduction in deaths (-0.6%) and fractures (-4.3%) over 10 years. The hypothetical scenario leads to greater reductions in costs associated with vertebral (-8.1%) and hip (-5.5%) fractures, followed by other non-vertebral (-3.0%) and forearm (-2.5%) fractures. In the hypothetical scenario, treatment initiations and total screenings increased almost tenfold versus the current scenario, at an estimated direct incremental cost of 27.83€ per woman per year in the cohort. DISCUSSION: Our study adds to the existing evidence on the impact of screening to prevent fractures amongst post-menopausal women. Despite being based on a stochastic model, our study confirms findings most recently published in the literature. CONCLUSIONS: Our study models the positive public health impact of increasing SLTC levels amongst post-menopausal women with a prior osteoporotic fracture.


Assuntos
Osteoporose Pós-Menopausa , Osteoporose , Fraturas por Osteoporose , Feminino , Humanos , Fraturas por Osteoporose/diagnóstico , Fraturas por Osteoporose/epidemiologia , Osteoporose Pós-Menopausa/complicações , Osteoporose Pós-Menopausa/diagnóstico , Osteoporose Pós-Menopausa/epidemiologia , Pós-Menopausa , Grécia/epidemiologia , Osteoporose/complicações , Osteoporose/diagnóstico , Osteoporose/epidemiologia
5.
Mult Scler ; 28(5): 718-729, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-34410179

RESUMO

BACKGROUND: Cortical demyelination and meningeal inflammation have been detected neuropathologically in multiple sclerosis (MS) and recently in myelin oligodendrocyte glycoprotein antibody disease (MOGAD). OBJECTIVES: To assess in vivo cortical and leptomeningeal involvement in MOGAD. METHODS: We prospectively evaluated 11 MOGAD and 12 relapsing-remitting MS (RRMS) patients combining three-dimensional fluid-attenuated inversion recovery (3D-FLAIR) and 3D-T1-weighted (3D-T1w) sequences at 3-Tesla magnetic resonance imaging (MRI). Leptomeningeal contrast enhancement (LMCE) was assessed on 3D-FLAIR post-gadolinium (3D-FLAIRGd). Cerebral cortical lesions (CCLs) were classified as either intracortical-subpial (IC-SP) or leukocortical (LC). RESULTS: CCLs were present in 8/11 MOGAD and 12/12 RRMS patients, with the number of CCLs being significantly lower in MOGAD (median (interquartile range (IQR)) 3 (0.5-4) vs 12 (4.75-19), p = 0.0032). In MOGAD, IC-SP lesions were slightly more prevalent than LC lesions (2 (0-2.5) vs 1 (0-2), p = 0.6579); whereas in RRMS, IC-SP lesions were less prevalent than LC lesions (3.5 (2.75-5.5) vs 9 (2-12.75), p = 0.27). LMCE was observed in 3/11 MOGAD and 1/12 RRMS patients; MOGAD with LMCE showed an increased median number of CCLs compared with MOGAD without LMCE (8 (4-9) vs 2.5 (0.75-3.25), p = 0.34). No correlation was observed between MOGAD MRI findings and (a) MOGAD duration, (b) serum MOG-immunoglobulin G1 titers, and (c) oligoclonal band presence. CONCLUSION: We described cortical lesion topography and detected for the first time LMCE using 3D-FLAIRGd sequences in MOGAD patients.


Assuntos
Imageamento por Ressonância Magnética , Esclerose Múltipla , Humanos , Imageamento Tridimensional , Inflamação/patologia , Imageamento por Ressonância Magnética/métodos , Meninges/diagnóstico por imagem , Meninges/patologia , Esclerose Múltipla/patologia , Glicoproteína Mielina-Oligodendrócito
6.
Vet Sci ; 10(1)2022 Dec 24.
Artigo em Inglês | MEDLINE | ID: mdl-36669010

RESUMO

Farm animals behavior research uses video cameras, mainly for visual observation and recording. The purpose of this feasibility study was to enrich the predictable methods of boar semen production capacity by correlating sperm variables with the scrotal contractions (SC) frequency and intensity. A video camera was used to record the reaction of the scrotum during ejaculation. The respective collected ejaculates were evaluated and semen parameters, such as viability, morphology, membranes functional integrity and kinematics, were determined. The camera recorded the scrotal contractions/relaxations and the video was handled by the Image Processing Toolbox of Matlab (Mathworks Inc., Natick, MA, USA). The SC intensity was verified as a percentage change in the scrotum size among the video frames of maximum contraction and relaxation. The archived data from the frames were analyzed statistically, using a linear mixed effects model that involved sperm assessed parameters. Correlations of the SC intensity with the average path velocity, VAP (R2 = 0.591, p = 0.043) and with the percentage of the cytoplasmic droplets (R2 = 0.509, p = 0.036) were noticed. Previous studies reported the positive correlation of VAP with the number of live-born piglets. In conclusion, video monitoring of the boar scrotal function during ejaculation is useful, but more research is needed to establish its appropriateness as a supplementary method for the prognosis of boar ability to produce high-quality semen.

7.
Front Pharmacol ; 12: 714841, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34630091

RESUMO

Voltage-gated Kv1.3 potassium channels are key regulators of T lymphocyte activation, proliferation and cytokine production, by providing the necessary membrane hyper-polarization for calcium influx following immune stimulation. It is noteworthy that an accumulating body of in vivo and in vitro evidence links these channels to multiple sclerosis pathophysiology. Here we studied the electrophysiological properties and the transcriptional and translational expression of T lymphocyte Kv1.3 channels in multiple sclerosis, by combining patch clamp recordings, reverse transcription polymerase chain reaction and flow cytometry on freshly isolated peripheral blood T lymphocytes from two patient cohorts with multiple sclerosis, as well as from healthy and disease controls. Our data demonstrate that T lymphocytes in MS, manifest a significant up-regulation of Kv1.3 mRNA, Kv1.3 membrane protein and Kv1.3 current density and therefore of functional membrane channel protein, compared to control groups (p < 0.001). Interestingly, patient sub-grouping shows that Kv1.3 channel density is significantly higher in secondary progressive, compared to relapsing-remitting multiple sclerosis (p < 0.001). Taking into account the tight connection between Kv1.3 channel activity and calcium-dependent processes, our data predict and could partly explain the reported alterations of T lymphocyte function in multiple sclerosis, while they highlight Kv1.3 channels as potential therapeutic targets and peripheral biomarkers for the disease.

8.
J Neurol Sci ; 410: 116673, 2020 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-31954354

RESUMO

IgG antibodies to myelin oligodendrocyte glycoprotein (MOG) detected by cell based assays (CBA) have been identified in a constantly expanding spectrum of CNS demyelinating disorders. However, a universally accepted CBA has not been adopted yet. We aimed to analyze the clinical and radiological features of patients with anti-MOG IgG1-antibodies detected with a live-cell CBA and to compare the three most popular MOG-CBAs. We screened sera from 1300 Greek patients (including 426 patients referred by our 8 clinics) suspected for anti-MOG syndrome, and 120 controls with the live-cell MOG-CBA for IgG1-antibodies. 41 patients, versus 0 controls were seropositive. Clinical, serological and radiological data were available and analyzed for the 21 seropositive patients out of the 426 patients of our clinics. Their phenotypes were: 8 optic neuritis, 3 myelitis, 3 neuromyelitis optica, 2 encephalomyelitis, 2 autoimmune encephalitis and 3 atypical MS. We then retested all sera of our 426 patients with the other two most popular MOG-CBAs for total IgG (a live-cell and a commercial fixed-cell CBAs). Seven IgG1-seropositive patients were seronegative for one or both IgG-CBAs. Yet, all 21 patients had clinical and radiological findings previously described in MOG-antibody associated demyelination disease supporting the high specificity of the IgG1-CBA. In addition, all IgG1-CBA-negative sera were also negative by the IgG-CBAs. Also, all controls were negative by all three assays, except one serum found positive by the live IgG-CBA. Overall, our findings support the wide spectrum of anti-MOG associated demyelinating disorders and the superiority of the MOG-IgG1 CBA over other MOG-CBAs.


Assuntos
Neuromielite Óptica , Neurite Óptica , Autoanticorpos , Humanos , Imunoglobulina G , Glicoproteína Mielina-Oligodendrócito , Neuromielite Óptica/diagnóstico por imagem
9.
Case Rep Emerg Med ; 2016: 4981274, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27761272

RESUMO

Guillain-Barré syndrome (GBS) is mainly classified into acute inflammatory demyelinating polyneuropathy (AIDP) and acute motor axonal neuropathy (AMAN). Although diagnosis of GBS requires progressive weakness and universal areflexia or hyporeflexia, cases of GBS with preserved or increased deep tendon reflexes (DTRs) have been increasingly recognized. We report three cases of GBS, presenting at a single unit in six months. Our first case presented with pure sensory symptoms. The second case had nonspecific generalized weakness, while the third presented with typical ascending weakness. One of our patients had preserved DTRs, while the other two had increased DTRs. Our two cases with hyperreflexia were found to have a preceding Campylobacter jejuni infection and anti-ganglioside antibodies, and their electrophysiological studies revealed AMAN. The other case had an AIDP. Only one case was offered a diagnosis and treatment from the first emergency department (ED) visit and had a better clinical outcome. Clinical diagnosis of GBS in the ED can be challenging. Delay in diagnosis of GBS in the ED is common due to cases with intact or increased DTRs, atypical pattern of weakness, or pure sensory symptoms. Emergency physicians should be aware of GBS clinical heterogeneity, because early diagnosis and treatment improve clinical outcome.

10.
J Neurol Sci ; 343(1-2): 192-4, 2014 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-24950904

RESUMO

Glutamic acid decarboxylase (GAD) has been recently identified as a target of humoral autoimmunity in a small subgroup of patients with non-paraneoplastic limbic encephalitis (NPLE). We present a patient with NPLE and positive anti-GAD antibodies who showed significant improvement after long-term immunotherapy. A 48-year old female was admitted with a two-year history of anterograde amnesia and seizures. Brain MRI revealed bilateral lesions of medial temporal lobes. Screening for anti-neuronal antibodies showed high anti-GAD titers in both serum and cerebrospinal fluid (CSF) with strong evidence of intrathecal production. The patient received treatment with prednisolone and long-term plasma exchange. During a 12-month follow-up, she exhibited complete seizure remission and an improvement in memory and visuo-spatial skills. Anti-GAD antibodies may serve as a useful marker to identify a subset of NPLE patients that respond to immunoregulatory treatment.


Assuntos
Anticorpos/sangue , Anticorpos/líquido cefalorraquidiano , Glutamato Descarboxilase/imunologia , Imunoterapia/métodos , Encefalite Límbica/terapia , Ácido Aspártico/análogos & derivados , Ácido Aspártico/metabolismo , Colina , Transtornos Cognitivos/etiologia , Transtornos Cognitivos/terapia , Creatina , Feminino , Humanos , Encefalite Límbica/sangue , Encefalite Límbica/líquido cefalorraquidiano , Encefalite Límbica/complicações , Imageamento por Ressonância Magnética , Pessoa de Meia-Idade , Transtornos da Percepção/etiologia , Transtornos da Percepção/terapia , Troca Plasmática/métodos , Prednisolona/uso terapêutico , Percepção Visual/efeitos dos fármacos , Percepção Visual/fisiologia
11.
Case Rep Neurol Med ; 2013: 608643, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24377054

RESUMO

Introduction. Paraneoplastic limbic encephalitis (PLE) is a rare disorder that typically follows a chronic or subacute course of personality changes, memory loss, seizures, and hallucinations. Early diagnosis is difficult and characteristic symptoms can be mimicked by a variety of conditions. We present a case of PLE, initially presenting as acute herpetic encephalitis. Case Presentation. A 56-year-old male was admitted for evaluation of acute onset headache, fever, and confusion. On neurological examination he was confused with MMSE score of 15/30. CSF analysis revealed marked lymphocytic pleocytosis. A possible diagnosis of acute herpetic encephalitis was rendered and patient was treated with acyclovir. CSF PCR was negative. Cranial MRI revealed bilateral hyperintense lesions in medial temporal lobes with contrast enhancement. Despite treatment with acyclovir patient was deteriorated; thus, a paraneoplastic syndrome was suspected. Chest CT showed a right paratracheal lymph node mass, while a biopsy revealed neuroendocrine lung cancer. Auto antibodies to Hu were also detected. The patient was treated with steroids and chemotherapy. Six months later, he had complete tumour remission and marked neurological improvement. Discussion. PLE can rarely invade acutely, being indistinguishable from herpetic encephalitis. Inclusion of PLE in the differential diagnosis of acute encephalitis is of great clinical significance.

12.
Prog Biophys Mol Biol ; 113(2): 254-63, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23872299

RESUMO

Personal radio frequency electromagnetic field (RF-EMF) exposure, or exposimetry, is gaining importance in the bioelectromagnetics community but only limited data on personal exposure is available in indoor areas, namely schools, crèches, homes, and offices. Most studies are focused on adult exposure, whereas indoor microenvironments, where children are exposed, are usually not considered. A method to assess spatial and temporal indoor exposure of children and adults is proposed without involving the subjects themselves. Moreover, maximal possible daily exposure is estimated by combining instantaneous spatial and temporal exposure. In Belgium and Greece, the exposure is measured at 153 positions spread over 55 indoor microenvironments with spectral equipment. In addition, personal exposimeters (measuring EMFs of people during their daily activities) captured the temporal exposure variations during several days up to one week at 98 positions. The data were analyzed using the robust regression on order statistics (ROS) method to account for data below the detection limit. All instantaneous and maximal exposures satisfied international exposure limits and were of the same order of magnitude in Greece and Belgium. Mobile telecommunications and radio broadcasting (FM) were most present. In Belgium, digital cordless phone (DECT) exposure was present for at least 75% in the indoor microenvironments except for schools. Temporal variations of the exposure were mainly due to variations of mobile telecommunication signals. The exposure was higher during daytime than at night due to the increased voice and data traffic on the networks. Total exposure varied the most in Belgian crèches (39.3%) and Greek homes (58.2%).


Assuntos
Carga Corporal (Radioterapia) , Ecossistema , Campos Eletromagnéticos , Exposição Ambiental/estatística & dados numéricos , Habitação/estatística & dados numéricos , Doses de Radiação , Monitoramento de Radiação/estatística & dados numéricos , Adulto , Bélgica , Criança , Grécia , Humanos , Instituições Acadêmicas/estatística & dados numéricos , Análise Espaço-Temporal , Local de Trabalho/estatística & dados numéricos
13.
Bioelectromagnetics ; 34(6): 443-52, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23613336

RESUMO

The spread of radio frequency identification (RFID) devices in ubiquitous applications without their simultaneous exposure assessment could give rise to public concerns about their potential adverse health effects. Among the various RFID system categories, the ultra high frequency (UHF) RFID systems have recently started to be widely used in many applications. This study addresses a computational exposure assessment of the electromagnetic radiation generated by a realistic UHF RFID reader, quantifying the exposure levels in different exposure scenarios and subjects (two adults, four children, and two anatomical models of women 7 and 9 months pregnant). The results of the computations are presented in terms of the whole-body and peak spatial specific absorption rate (SAR) averaged over 10 g of tissue to allow comparison with the basic restrictions of the exposure guidelines. The SAR levels in the adults and children were below 0.02 and 0.8 W/kg in whole-body SAR and maximum peak SAR levels, respectively, for all tested positions of the antenna. On the contrary, exposure of pregnant women and fetuses resulted in maximum peak SAR(10 g) values close to the values suggested by the guidelines (2 W/kg) in some of the exposure scenarios with the antenna positioned in front of the abdomen and with a 100% duty cycle and 1 W radiated power.


Assuntos
Campos Eletromagnéticos/efeitos adversos , Feto/efeitos da radiação , Gravidez/efeitos da radiação , Dispositivo de Identificação por Radiofrequência , Adulto , Criança , Pré-Escolar , Simulação por Computador , Radiação Eletromagnética , Feminino , Humanos , Modelos Anatômicos , Imagens de Fantasmas
14.
Health Phys ; 104(3): 293-301, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23361425

RESUMO

This is the first measurement campaign that takes place in Greece in order to assess the exposure levels in different microenvironments (offices, bedrooms, living rooms, schools). Due to the exponential growth in the use of wireless network devices, the aim of this work was to perform indoor measurements with the use of personal dosimeters. The measurement period was 3 d in each of the 40 different locations that were selected, both in the urban and suburban area of Thessaloniki, the second largest city of Greece. The measurements took place from 23 July 2010 to 19 January 2012. After processing the obtained data with the robust regression on order statistics (ROS) method, various statistical exposure quantities were calculated. Compared to similar measurement campaigns across Europe, a larger proportion of measurement data above the detection limit for specific frequency bands (at most 56% for the DCS Rx frequency band) was found. Furthermore, mean exposure levels in the mobile downlink frequency bands were higher than those in other studies (GSM Rx: 0.259 V m, DCS Rx: 0.131 V m, UMTS Rx: 0.12 V m), yet many times below the ICNIRP guidelines. On the other hand, maximum exposures were found to be of the same magnitude (GSM Rx: 0.38 V m, DCS Rx: 0.3 V m, UMTS Rx: 0.28 V m). These measurement results indicate that signals from mobile base stations are dominant in workplaces and schools, whereas wireless phones and computer networks play the leading role in home environments. While the former reach their maximum values during daytime, the latter have an observable increase in the evening after work hours.


Assuntos
Meio Ambiente , Exposição Ambiental/análise , Monitoramento de Radiação , Ondas de Rádio , Cidades/estatística & dados numéricos , Grécia , Limite de Detecção , Fatores de Tempo
15.
Neurobiol Dis ; 37(2): 339-48, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19850126

RESUMO

In Alzheimer's disease (AD), potassium channel abnormalities have been reported in both neural and peripheral tissues. Herein, using whole-cell patch-clamp, we demonstrate an aberrant glutamate-dependent modulation of K(V)1.3 channels in T lymphocytes of AD patients. Although intrinsic K(V)1.3 properties in patients were similar to healthy individuals, glutamate (1-1000 microM) failed to yield the hyperpolarizing shift normally observed in K(V)1.3 steady-state inactivation (-4.4+/-2.7 mV in AD vs. -14.3+/-2.5 mV in controls, 10 microM glutamate), resulting in a 4-fold increase of resting channel activity. Specific agonist and antagonist data indicate that this abnormality is due to dysfunction of cognate group II mGluRs. Given that glutamate is present in plasma and that both mGluRs and K(V)1.3 channels regulate T-lymphocyte responsiveness, our finding may account for the presence of immune-associated alterations in AD. Furthermore, if this aberration reflects a corresponding one in neural tissue, it could provide a potential target in AD pathogenesis.


Assuntos
Doença de Alzheimer/metabolismo , Ácido Glutâmico/metabolismo , Canal de Potássio Kv1.3/metabolismo , Receptores de Glutamato Metabotrópico/metabolismo , Linfócitos T/metabolismo , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer/imunologia , Doença de Alzheimer/fisiopatologia , Infarto Encefálico/imunologia , Infarto Encefálico/metabolismo , Infarto Encefálico/fisiopatologia , Membrana Celular/efeitos dos fármacos , Membrana Celular/metabolismo , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Agonistas de Aminoácidos Excitatórios/farmacologia , Antagonistas de Aminoácidos Excitatórios/farmacologia , Feminino , Ácido Glutâmico/farmacologia , Humanos , Ativação do Canal Iônico/efeitos dos fármacos , Ativação do Canal Iônico/fisiologia , Canal de Potássio Kv1.3/efeitos dos fármacos , Ativação Linfocitária/efeitos dos fármacos , Ativação Linfocitária/fisiologia , Masculino , Potenciais da Membrana/efeitos dos fármacos , Potenciais da Membrana/fisiologia , Mitógenos/farmacologia , Neuroimunomodulação/fisiologia , Técnicas de Patch-Clamp , Fito-Hemaglutininas/farmacologia , Receptores de Glutamato Metabotrópico/agonistas , Linfócitos T/efeitos dos fármacos , Linfócitos T/imunologia
16.
Clin Neurol Neurosurg ; 110(6): 619-21, 2008 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18433986

RESUMO

Opsoclonus-myoclonus-ataxia syndrome (OMS) is a rare neurological disorder of probably autoimmune origin. Most cases are associated with a remote neoplasm or a viral infection; however in some instances no underlying aetiology can be demonstrated. We report the presence of anti-glutamic acid decarboxylase antibodies (anti-GAD Abs) in the serum and CSF of a patient with idiopathic OMS. Treatment with intravenous immunoglobulin led to a remarkable clinical improvement with parallel reduction of anti-GAD titers. Anti-GAD Abs have been associated with several neurological syndromes. They could also be responsible for the clinical triad of OMS, by impairing GABAergic transmission in specific brainstem and cerebellar circuits. We propose that testing for anti-GAD Abs should be performed in OMS, especially when no other aetiological association can be demonstrated.


Assuntos
Autoanticorpos/análise , Doenças Autoimunes/complicações , Doenças Autoimunes/imunologia , Marcha Atáxica/etiologia , Marcha Atáxica/imunologia , Glutamato Descarboxilase/imunologia , Mioclonia/etiologia , Mioclonia/imunologia , Transtornos da Motilidade Ocular/etiologia , Transtornos da Motilidade Ocular/imunologia , Adulto , Anti-Inflamatórios/uso terapêutico , Anticonvulsivantes/uso terapêutico , Autoanticorpos/sangue , Autoanticorpos/líquido cefalorraquidiano , Feminino , Marcha Atáxica/tratamento farmacológico , Humanos , Metilprednisolona/uso terapêutico , Mioclonia/tratamento farmacológico , Transtornos da Motilidade Ocular/tratamento farmacológico , Radioimunoensaio , Síndrome , Ácido Valproico/uso terapêutico
17.
Ann Neurol ; 58(6): 946-9, 2005 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-16240362

RESUMO

Metabotropic glutamate receptors alter the vulnerability of neurons to excitotoxic damage and are reported to display abnormal expression in the central nervous system of ALS patients. Using reverse transcriptase polymerase chain reaction, we investigated the mRNA expression of specific metabotropic glutamate receptor subtypes in T lymphocytes of 20 patients with sporadic ALS, compared with healthy age-matched control subjects and patients with other neurological disorders. The levels of metabotropic glutamate receptor 2 mRNA were markedly reduced, whereas the expression of other subtypes (1b, 3, 8) was similar to control levels. Our findings may provide a reliable peripheral marker of the glutamatergic dysfunction that characterizes ALS.


Assuntos
Esclerose Lateral Amiotrófica/genética , Esclerose Lateral Amiotrófica/fisiopatologia , Marcadores Genéticos , Receptores de Glutamato Metabotrópico/genética , Linfócitos T/fisiologia , Adulto , Idoso , Feminino , Expressão Gênica , Humanos , Masculino , Pessoa de Meia-Idade , RNA Mensageiro/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa
18.
Mol Pharmacol ; 67(3): 856-67, 2005 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-15718225

RESUMO

Glutamate is present in the plasma under tightly regulated concentrations. However, under conditions of immune deficiency, such as AIDS and malignancy, its plasma levels are highly elevated. In vitro, glutamate interacts with T lymphocytes, affecting mitogen-induced calcium responses, whereas at high doses, it impairs T lymphocyte proliferation, a process strongly dependent on the activity of voltage-gated potassium channels. In this study, we demonstrate novel dose-related effects of the endogenous ligand glutamate and its metabotropic and non-N-methyl-D-aspartic acid receptor agonists on the electrophysiological properties of native Kv1.3 channels of human T lymphocytes. Glutamate, at concentrations within normal plasma levels, positively modulates Kv1.3 channel gating, causing currents to activate faster and at significantly more hyperpolarized potentials, hence rendering the T lymphocyte readily responsive to immune stimuli. This effect is maximal at 1 microM Glu and is fully mimicked by a 100 microM concentration of the metabotropic receptor agonist trans-(1S,3R)-1-aminocyclopentane-1,3-dicarboxylic acid. Most importantly, Glu, at concentrations > or =100 microM, which in vitro produce suppression of mitogen-induced proliferation, significantly decreases whole-cell potassium currents by increasing current and steady-state inactivation. This effect saturates at 1000 microM and seems to result from the subsequent activation of low-affinity metabotropic Glu receptors, as suggested by specific agonist data. Therefore, the antiproliferative effects of high glutamate may, at least in part, result from its inhibitory effect on the potassium current, suggesting an in vivo immunosuppressive role of elevated plasma glutamate.


Assuntos
Ácido Glutâmico/farmacologia , Canais de Potássio de Abertura Dependente da Tensão da Membrana/fisiologia , Linfócitos T/fisiologia , Células Cultivadas , Humanos , Canal de Potássio Kv1.3 , Potenciais da Membrana/efeitos dos fármacos , Técnicas de Patch-Clamp , Canais de Potássio de Abertura Dependente da Tensão da Membrana/efeitos dos fármacos , Linfócitos T/efeitos dos fármacos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...