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1.
Front Hum Neurosci ; 17: 1206027, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37706171

RESUMO

Background: Prior work suggests that vibratory stimulation can reduce spasticity and hypertonia. It is unknown which of three predominant approaches (stimulation of the spastic muscle, antagonist muscle, or cutaneous regions) most reduces these symptoms. Objective: Determine which vibrotactile stimulation approach is most effective at reducing spastic hypertonia among post-stroke patients. Methods: Sham-controlled crossover study with random assignment of condition order in fourteen patients with post-stroke hand spasticity. All patients were studied in four conditions over four visits: three stimulation conditions and a sham control. The primary outcome measure was the Modified Ashworth Scale, and the secondary outcome measure was the Modified Tardieu Scale measured manually and using 3D motion capture. For each condition, measures of spastic hypertonia were taken at four time points: baseline, during stimulation, after stimulation was removed, and after a gripping exercise. Results: A clinically meaningful difference in spastic hypertonia was found during and after cutaneous stimulation of the hand. Modified Ashworth and Modified Tardieu scores were reduced by a median of 1.1 (SD = 0.84, p = 0.001) and 0.75 (SD = 0.65, p = 0.003), respectively, during cutaneous stimulation, and by 1.25 (SD = 0.94, p = 0.001) and 0.71 (SD = 0.67, p = 0.003), respectively, at 15 min after cutaneous stimulation. Symptom reductions with spastic muscle stimulation and antagonist muscle stimulation were non-zero but not significant. There was no change with sham stimulation. Conclusions: Cutaneous vibrotactile stimulation of the hand provides significant reductions in spastic hypertonia, compared to muscle stimulation. Clinical trial registration: www.ClinicalTrials.gov, identifier: NCT03814889.

2.
J Biomech ; 153: 111596, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-37126882

RESUMO

Upper limb motion can be challenging to measure and analyze during work or daily life tasks. Further, humeral angle calculation method substantially influences angle outcomes. Therefore, the purpose of this study was to assess the repeatability of scapular and humeral kinematics and compare thoracohumeral angle calculation during a work-related and functional task (WRAFT) protocol. Thirty healthy young adults completed the WRAFT protocol (Comb Hair, Wash Axilla, Tie Apron, Overhead Reach, Side Reach, Forward Transfer, Floor Lift, and Overhead Lift) on two separate occasions. Peak humeral angles and select scapular angles were extracted for each task. Intra-class correlation coefficients (ICCs), standard error of measurement, and minimal detectable change (MDC) were examined. Humeral angles were compared using the XZY and ZXY rotation sequences and "true" axial rotation for incidence of gimbal lock and amplitude coherence. Results showed that for scapular kinematics, elevation-based WRAFTs produced overall better ICC scores (0.23-0.90) compared to those tasks primarily driven by lateral humeral motion (0.02-0.84). MDCs ranged from 7°-78°, suggesting some tasks demonstrated good repeatability (Comb Hair, Overhead Reach, Floor Lift), while others had very high variability (Side Reach, Tie Apron). Amplitude coherence for thoracohumeral angles was best for ZXY for all tasks except the Comb Hair and Tie Apron, for which XZY is recommended. "True" axial rotation demonstrated good coherence for all but Tie Apron. The WRAFT protocol may be used for functionally relevant scapular and humeral kinematic assessment for select task and posture combinations.


Assuntos
Movimento , Articulação do Ombro , Adulto Jovem , Humanos , Amplitude de Movimento Articular , Escápula , Úmero , Extremidade Superior , Fenômenos Biomecânicos , Rotação
3.
Eye (Lond) ; 37(15): 3271-3281, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36944709

RESUMO

BACKGROUND/OBJECTIVES: Ocular syphilis is a vision-threatening disease that can lead to permanent blindness if left untreated. The global re-emergence of syphilis warrants greater investigations into the visual prognosis of eyes affected by this potentially devastating disease. This systematic review investigates the impact of HIV on visual acuity (VA) outcomes in ocular syphilis. METHODS: A literature search of Medline, PubMed, Embase, Clinicaltrials.gov and Cochrane Reviews was conducted for studies published between 01 January 2011 and 19 March 2022, reporting non-aggregate initial and post-treatment VA data of eyes with ocular syphilis and corresponding HIV status in patients ≥ 18 years. RESULTS: A total of 95 studies, including 364 patients and 568 eyes, were evaluated. Among people living with HIV with a diagnosis of ocular syphilis, affected eyes were more likely to have optic nerve involvement and panuveitis. However, HIV status, CD4 cell count, and HIV viral load were not predictive of VA outcomes of treated ocular syphilis. Prognostic factors of final VA worse than 1.00 logMAR were female sex, the presence of macular edema, and VA ≥ 1.00 at presentation. The strongest predictor of a worse final VA was VA ≥ 1.00 at presentation. CONCLUSIONS: This systematic review demonstrates that HIV status, CD4 cell count, and HIV viral load are not significant factors impacting VA outcomes of eyes with ocular syphilis. While visual prognosis is generally good, poor visual outcome is most strongly predicted by poor VA at presentation. This underscores the importance of early recognition and treatment prior to permanent vision loss.

4.
JAMA Ophthalmol ; 141(3): 291-293, 2023 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-36757710

RESUMO

This case report describes a 37-year-old female individual who presented with sudden-onset blurred vision in both eyes 4 days after testing positive for COVID-19.


Assuntos
COVID-19 , Doenças Retinianas , Humanos , Doenças Retinianas/diagnóstico , Doenças Retinianas/etiologia , Angiofluoresceinografia
5.
Biochem Soc Trans ; 51(1): 57-70, 2023 02 27.
Artigo em Inglês | MEDLINE | ID: mdl-36629496

RESUMO

The discovery of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) along with its potent and selective antitumor effects initiated a decades-long search for therapeutic strategies to target the TRAIL pathway. First-generation approaches were focused on the development of TRAIL receptor agonists (TRAs), including recombinant human TRAIL (rhTRAIL) and TRAIL receptor-targeted agonistic antibodies. While such TRAIL pathway-targeted therapies showed promise in preclinical data and clinical trials have been conducted, none have advanced to FDA approval. Subsequent second-generation approaches focused on improving upon the specific limitations of first-generation approaches by ameliorating the pharmacokinetic profiles and agonistic abilities of TRAs as well as through combinatorial approaches to circumvent resistance. In this review, we summarize the successes and shortcomings of first- and second-generation TRAIL pathway-based therapies, concluding with an overview of the discovery and clinical introduction of ONC201, a compound with a unique mechanism of action that represents a new generation of TRAIL pathway-based approaches. We discuss preclinical and clinical findings in different tumor types and provide a unique perspective on translational directions of the field.


Assuntos
Apoptose , Receptores de Morte Celular , Humanos
6.
Cureus ; 15(12): e49866, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38170042

RESUMO

Anti-GQ1b antibodies are considered a hallmark of Miller-Fisher syndrome (MFS), a rare variant of Guillain-Barré syndrome (GBS). The typical clinical presentation of MFS includes ophthalmoplegia, ataxia, and areflexia. Here, we present an unusual case of a 65-year-old man with acute-onset quadriplegia and bulbar weakness resembling locked-in syndrome. Imaging studies did not show structural lesions as a cause for his clinical symptoms. Nerve conduction studies showed severe axonal sensory-motor polyneuropathy. Serum studies were all negative except for a positive anti-GQ1b antibody. He was treated with plasmapheresis as MFS, with a quick improvement in muscle strength. Our case report provided further information on the clinical variation of anti-GQ1b syndrome. Physicians should pay more attention to unusual presentations of anti-GQ1b syndrome because, when it is recognized early with prompt treatment, patients are expected to have a good recovery.

7.
Cureus ; 14(2): e22590, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-35355549

RESUMO

The objective is to describe a rare case of lumbar lipomyelomeningocele presenting as progressive urinary incontinence. Lipomyelomeningocele is a type of closed spinal dysraphism typically presenting as a lipomatous mass contiguous with a neural defect above the gluteal crease. Tethered cord syndrome is defined as symptoms and signs caused by excessive spinal cord tension from an abnormally low conus medullaris, with an abnormally thick filum terminale attached to the lower sacral region. A 19-year-old male with no remarkable medical history presented with low back pain and urinary incontinence for the past one year. On physical exam patient had normal motor strength, sensory testing to all modalities was intact. The rectal tone was normal, and no saddle anesthesia was noted. MRI lumbar spine revealed lumbar lipomyelomeningocele with associated tethered cord syndrome. The patient underwent tethered cord release surgery with lipoma excision. Pathology of the soft tissue showed fibrovascular tissue and mature adipose tissue consistent with lipoma. The majority of cases of tethered cord syndrome are related to spinal dysraphism, a rare pediatric syndrome. It is potentially treatable if caught early, and MRI can help with an accurate diagnosis of the condition. Older adults are more likely to present with urological and neurological complaints. Surgical un-tethering is indicated in patients with progressive symptoms. In our case, the only presenting symptom was urinary incontinence, and the neurological exam was normal other than lower lumbar paraspinal tenderness.

9.
Med Sci Educ ; 30(1): 339-344, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-34457676

RESUMO

INTRODUCTION: Case-based learning (CBL) is a pedagogical method using clinical case studies to reinforce learning topics. A pilot elective course incorporating CBL was offered for first-year medical students. The purpose of this study is to (1) describe the logistics of implementing the course and (2) evaluate its reception among medical students on its efficacy in learning basic science class material. METHOD: An 8-week elective course was offered to medical students from 2012 to 2017. Specialists facilitated case discussions synthesizing material from didactic lectures with clinical scenarios. End-of-term surveys with multiple choice and free response questions were distributed to students and described using summary statistics. RESULTS: There were 13 cohorts of enrollees, and the average number of students enrolled per cohort was 45.6, out of an average class size of 186 (24.5%, range 36-60). One hundred ninety-eight (64.2%) students reported that the course considerably changed or greatly expanded knowledge. Three hundred two (89.1%) students felt it met a majority of or exceeded expectations. Two hundred eighty-seven (80.2%) responses indicated interest in taking the course again or recommending it to others. One hundred six responses (27.1%) indicated preference for CBL over traditional lectures, and 177 (45.3%) were interested to see CBL integrated into the curriculum. CONCLUSIONS: Overall, this CBL elective course was well-received and perceived as effective for better learning class material by students. Additionally, students were receptive to case-based learning and integrating this style of learning into a preclinical curriculum without entirely replacing didactic-based learning. These findings may encourage more medical schools to explore incorporating CBL in the curriculum.

11.
J Cell Sci ; 127(Pt 10): 2302-12, 2014 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-24610951

RESUMO

The mammalian nucleolar proteins nucleostemin and GNL3-like (GNL3L) are encoded by paralogous genes that arose from an ancestral invertebrate gene, GNL3. Invertebrate GNL3 has been implicated in ribosome biosynthesis, as has its mammalian descendent, GNL3L. The paralogous mammalian nucleostemin protein has, instead, been implicated in cell renewal. Here, we found that depletion of nucleostemin in a human breast carcinoma cell line triggers prompt and significant DNA damage in S-phase cells without perturbing the initial step of ribosomal (r)RNA synthesis and only mildly affects the total ribosome production. By contrast, GNL3L depletion markedly impairs ribosome production without inducing appreciable DNA damage. These results indicate that, during vertebrate evolution, GNL3L retained the role of the ancestral gene in ribosome biosynthesis, whereas the paralogous nucleostemin acquired a novel genome-protective function. Our results provide a coherent explanation for what had seemed to be contradictory findings about the functions of the invertebrate versus vertebrate genes and are suggestive of how the nucleolus was fine-tuned for a role in genome protection and cell-cycle control as the vertebrates evolved.


Assuntos
Proteínas de Ligação ao GTP/metabolismo , Proteínas Nucleares/metabolismo , Ribossomos/metabolismo , Neoplasias da Mama/genética , Neoplasias da Mama/metabolismo , Ciclo Celular , Linhagem Celular Tumoral , Nucléolo Celular/metabolismo , Dano ao DNA , Feminino , Proteínas de Ligação ao GTP/deficiência , Proteínas de Ligação ao GTP/genética , Humanos , Proteínas Nucleares/deficiência , Proteínas Nucleares/genética , Fase S/fisiologia
12.
Mov Disord ; 29(1): 126-30, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24150997

RESUMO

OBJECTIVES: Haloperidol and pimozide are the only drugs currently approved by the U.S. Food and Drug Administration for treatment of Tourette syndrome (TS), but their potential side effects, which include tardive dyskinesia (TD), limit their use. METHODS: We performed a retrospective chart review of patients with TS treated with fluphenazine over a 26-year period. RESULTS: Among 268 patients with TS, fluphenazine was initiated at a mean age of 15.8 ± 10.7 years (range, 4.1-70.2) and titrated to an optimal dose of 3.24 ± 2.3 mg/day (range, 0.5-12.0), which was continued for an average of 2.6 ± 3.2 years (range, 0.01-16.8). Marked to moderate improvement was noted in 211 (80.5%). The most common side effects included drowsiness, fatigue, or both, observed in 70 (26.1%) patients. There were no cases of TD. CONCLUSIONS: Fluphenazine appears to be safe and effective in the treatment of TS, and there were no cases of TD in this cohort treated up to 16.8 years.


Assuntos
Antagonistas de Dopamina/uso terapêutico , Flufenazina/uso terapêutico , Síndrome de Tourette/tratamento farmacológico , Adolescente , Adulto , Idoso , Criança , Pré-Escolar , Antagonistas de Dopamina/efeitos adversos , Feminino , Flufenazina/efeitos adversos , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Resultado do Tratamento , Adulto Jovem
13.
J Biol Chem ; 287(52): 43410-6, 2012 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-23129768

RESUMO

The mixed lineage leukemia protein MLL1 contains four highly conserved plant homeodomain (PHD) fingers, which are invariably deleted in oncogenic MLL1 fusion proteins in human leukemia. Here we show that the second PHD finger (PHD2) of MLL1 is an E3 ubiquitin ligase in the presence of the E2-conjugating enzyme CDC34. This activity is conserved in the second PHD finger of MLL4, the closest homolog to MLL1 but not in MLL2 or MLL3. Mutation of PHD2 leads to MLL1 stabilization, as well as increased transactivation ability and MLL1 recruitment to the target gene loci, suggesting that PHD2 negatively regulates MLL1 activity.


Assuntos
Proteínas de Ligação a DNA/metabolismo , Proteína de Leucina Linfoide-Mieloide/metabolismo , Ativação Transcricional/fisiologia , Complexos Ubiquitina-Proteína Ligase/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Ciclossomo-Complexo Promotor de Anáfase , Proteínas de Ligação a DNA/genética , Estabilidade Enzimática/fisiologia , Células HEK293 , Histona-Lisina N-Metiltransferase , Humanos , Mutação , Proteína de Leucina Linfoide-Mieloide/genética , Proteínas de Neoplasias/genética , Proteínas de Neoplasias/metabolismo , Estrutura Terciária de Proteína , Enzimas de Conjugação de Ubiquitina , Complexos Ubiquitina-Proteína Ligase/genética , Ubiquitina-Proteína Ligases/genética
14.
Parkinsonism Relat Disord ; 18(4): 377-81, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-22236581

RESUMO

BACKGROUND: For Parkinson's disease (PD) patients, adherence to a regular PD medication schedule is important in achieving optimal symptom control. There are few published studies quantifying PD medication administrations in hospitalized PD patients. METHODS: Hospitalization records for 100 veterans with idiopathic PD and admitted to our center were reviewed to determine the on time rate and contraindicated medication doses. A barcode based computerized medication administration system within the electronic medical record provided information of the exact time the medication was given to a patient. RESULTS: Eighty-nine idiopathic PD patients met study inclusion criteria. Among them, 87 were on levodopa monotherapy or in combination with other PD medications. Two patients were on dopamine agonists only. A total of 3873 doses of PD medications were prescribed during hospitalization. Among 675 incorrect medication administrations, 322 doses were omitted, 300 doses late by ≥ 30 min, and 53 doses given early by ≥ 30 min. Contraindicated medications were prescribed for 19 patients. The correct administration percentage was lower during the first 2 days post-admission compared to subsequent days (mean 74.6% vs. 82.8%) and higher for patients who had neurological consultations (mean 85.5% vs. 76.5%). Correct administration rates were better for patient-based medication schedules (85.6%) than with hospital-based schedules (77.5%), but did not achieve statistical significance. CONCLUSION: Adherence to regular PD medication dosing schedules during hospitalization is problematic, but improves with specialist consultation. Staff involved in the admission process for PD patients should work to safeguard against disruption of the prescribed home dosing schedule.


Assuntos
Antiparasitários/uso terapêutico , Hospitalização , Levodopa/uso terapêutico , Doença de Parkinson/tratamento farmacológico , Admissão do Paciente , Idoso , Idoso de 80 Anos ou mais , Feminino , Hospitais de Veteranos , Humanos , Masculino , Sistemas Computadorizados de Registros Médicos , Adesão à Medicação , Erros de Medicação , Pessoa de Meia-Idade , Assistência Farmacêutica/estatística & dados numéricos , Estudos Retrospectivos , Estatísticas não Paramétricas , Veteranos
15.
Qual Manag Health Care ; 20(1): 37-48, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21192206

RESUMO

PURPOSE: To test the effect of an Appreciative Inquiry (AI) quality improvement strategy on clinical quality management and practice development outcomes. Appreciative inquiry enables the discovery of shared motivations, envisioning a transformed future, and learning around the implementation of a change process. METHODS: Thirty diverse primary care practices were randomly assigned to receive an AI-based intervention focused on a practice-chosen topic and on improving preventive service delivery (PSD) rates. Medical-record review assessed change in PSD rates. Ethnographic field notes and observational checklist analysis used editing and immersion/crystallization methods to identify factors affecting intervention implementation and practice development outcomes. RESULTS: The PSD rates did not change. Field note analysis suggested that the intervention elicited core motivations, facilitated development of a shared vision, defined change objectives, and fostered respectful interactions. Practices most likely to implement the intervention or develop new practice capacities exhibited 1 or more of the following: support from key leader(s), a sense of urgency for change, a mission focused on serving patients, health care system and practice flexibility, and a history of constructive practice change. CONCLUSIONS: An AI approach and enabling practice conditions can lead to intervention implementation and practice development by connecting individual and practice strengths and motivations to the change objective.


Assuntos
Atenção Primária à Saúde/organização & administração , Prevenção Primária/organização & administração , Melhoria de Qualidade/organização & administração , Adulto , Fatores Etários , Feminino , Humanos , Liderança , Masculino , Pessoa de Meia-Idade , Motivação , Grupos Raciais , Fatores Sexuais
16.
Parkinsonism Relat Disord ; 15(10): 758-61, 2009 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19505838

RESUMO

Motor overflow is an unintentional muscle contraction which accompanies, but is anatomically distinct from the primary dystonic movement. This phenomenological nosology has not been systematically studied in focal hand dystonia (FHD). We conducted a prospective, case-control study to characterize motor overflow and mirror dystonia in patients with FHD. We compared the performance of 30 patients with FHD and 40 healthy controls on a variety of motor tasks, such as writing, drawing a spiral, straight line and a sine wave, repetitive wrist flexion-extension, finger tapping, hand grasping, hand pronation-supination, and a finger-to-nose task with each hand. The assessments were videotaped, the edited video segments were randomized, and an independent investigator who was "blind" to the subject's diagnosis rated the ipsilateral and contralateral overflow and mirror dystonia twice, 6 months apart. Using the mean of the two ratings, ipsilateral overflow was identified in 8.5 +/- 2.1 (28%) patients and in 1.5 +/- 0.7 (4%) controls (p < 0.001), contralateral overflow in 2.5 +/- 0.7 (8%) patients and in 1.5 +/- 0.7 (4%) of controls (p = 0.138), and mirror movement in 20.0 +/- 0.0 (67%) of patients and in 15.5 +/- 4.9 (39%) of controls (p = 0.001). There was a statistically significant correlation of dystonia and overflow score (Pearson's r 0.713, p < 0.001). The relatively high frequency of ipsilateral overflow and mirror dystonia in patients with FHD has both pathophysiological and therapeutic implications. In this study, the severity of dystonia was significantly correlated with motor overflow in multiple tasks.


Assuntos
Distúrbios Distônicos/fisiopatologia , Mãos/fisiopatologia , Movimento/fisiologia , Contração Muscular/fisiologia , Adulto , Idoso , Estudos de Casos e Controles , Eletromiografia/métodos , Feminino , Lateralidade Funcional/fisiologia , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Estudos Prospectivos , Reprodutibilidade dos Testes
17.
Mov Disord ; 23(16): 2307-11, 2008 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-18972544

RESUMO

The applause sign has been previously reported to be indicative of neurodegenerative disorders, such as progressive supranuclear palsy (PSP). In order to determine the sensitivity, specificity, and positive predictive value, we tested it in patients with PSP, Parkinson's disease (PD), multiple system atrophy (MSA), corticobasal degeneration (CBD), and Huntington's disease (HD). Subjects were asked to clap three times after demonstration by the examiner. The performance was scored as follows: 3 = claps only three times; 2 = claps four times; 1 = claps 5 to 10 times; 0 = claps >10 times. The clap test was videotaped and rated. Patients with CBD, MSA, and PSP showed significant differences in clap scores compared with normal controls. The test differentiated patients with CBD from those with PD (P < 0.005) and HD (P < 0.005), but failed to discriminate patients with PSP from other parkinsonian groups. The specificity of the applause sign is 100% in distinguishing parkinsonian patients from normal subjects with the highest sensitivity in CBD patients. We concluded that the applause sign is highly specific for parkinsonian disorders but it is not a specific sign for PSP; it appears to be most sensitive for CBD.


Assuntos
Comportamento Compulsivo/etiologia , Doença de Huntington/complicações , Transtornos Parkinsonianos/complicações , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Entrevista Psiquiátrica Padronizada , Pessoa de Meia-Idade , Exame Neurológico , Valor Preditivo dos Testes , Sensibilidade e Especificidade , Índice de Gravidade de Doença , Estatística como Assunto
18.
J Neurol Sci ; 251(1-2): 73-6, 2006 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-17097111

RESUMO

Adult-onset focal dystonia in the upper limbs is well characterized whereas such dystonia has been rarely reported in the lower limbs, especially in proximal parts. When such focal dystonia occurs in an athlete it is often wrongly attributed to an orthopedic disorder. We present five cases, three female and two male with mean age of 44.6+/-10.43 years, mean age at onset of 37.4+/-10.33 years, and mean duration of symptoms for 7.2+/-4.44 years, who initially noted dystonia of one leg during long-distance running. The clinical features of dystonia in these long-distance runners overlap with those of more recognizable forms of focal dystonia including relief with sensory or motor "tricks". They also share features with paroxysmal dyskinesia and carbamazepine markedly ameliorated the symptoms at least in one patient. One patient benefited from an oral anticholinergic, one from levodopa, and another two patients benefited from repeat botulinum toxin injections. Our patients differed from the typical childhood-onset leg dystonia, such as the DYT1 dystonia, in that there was no family history of dystonia and the leg dystonia remained focal without spreading to other body parts. Two of our patients had prior injury to the affected leg within 1 year prior to the onset of the dystonia, raising the possibility of peripherally-induced dystonia. We draw attention to this rare, disabling, adult-onset focal dystonia involving proximal lower limbs. When recognized early, it may be treated effectively with either anticholinergic drugs, anticonvulsants, levodopa, or botulinum toxin injections.


Assuntos
Distúrbios Distônicos/fisiopatologia , Corrida/fisiologia , Adulto , Antidiscinéticos/uso terapêutico , Anticonvulsivantes/uso terapêutico , Toxinas Botulínicas/uso terapêutico , Carbamazepina/uso terapêutico , Discinesias/tratamento farmacológico , Discinesias/etiologia , Distúrbios Distônicos/tratamento farmacológico , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
19.
Brain Res ; 1001(1-2): 108-17, 2004 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-14972659

RESUMO

Iron homeostasis in the mammalian brain is an important and poorly understood subject. Transferrin-bound iron enters the endothelial cells of the blood-brain barrier from the systemic circulation, and iron subsequently dissociates from transferrin to enter brain parenchyma by an unknown mechanism. In recent years, several iron transporters, including the iron importer DMT1 (Ireg1, MTP, DCT1) and the iron exporter ferroportin (SLC11A3, Ireg, MTP1) have been cloned and characterized. To better understand brain iron homeostasis, we have characterized the distribution of ferroportin, the presumed intestinal iron exporter, and have evaluated its potential role in regulation of iron homeostasis in the central nervous system. We discovered using in situ hybridization and immunohistochemistry that ferroportin is expressed in the endothelial cells of the blood-brain barrier, in neurons, oligodendrocytes, astrocytes, and the choroid plexus and ependymal cells. In addition, we discovered using techniques of immunoelectron microscopy and biochemical purification of synaptic vesicles that ferroportin is associated with synaptic vesicles. In the blood-brain barrier, it is likely that ferroportin serves as a molecular transporter of iron on the abluminal membrane of polarized endothelial cells. The role of ferroportin in synaptic vesicles is unknown, but its presence at that site may prove to be of great importance in neuronal iron toxicity. The widespread representation of ferroportin at sites such as the blood-brain barrier and synaptic vesicles raises the possibility that trafficking of elemental iron may be instrumental in the distribution of iron in the central nervous system.


Assuntos
Barreira Hematoencefálica/metabolismo , Proteínas de Transporte de Cátions/metabolismo , Expressão Gênica , Vesículas Sinápticas/metabolismo , Animais , Barreira Hematoencefálica/citologia , Western Blotting , Encéfalo/citologia , Encéfalo/metabolismo , Proteínas de Transporte de Cátions/genética , Proteínas de Transporte de Cátions/imunologia , Células Endoteliais/metabolismo , Proteína Glial Fibrilar Ácida/metabolismo , Imuno-Histoquímica/métodos , Hibridização In Situ/métodos , Ferro/metabolismo , Proteína 2 Reguladora do Ferro/genética , Camundongos , Camundongos Knockout , Microscopia Imunoeletrônica/métodos , Peptídeos/imunologia , Peptídeos/metabolismo , Vesículas Sinápticas/ultraestrutura , Sinaptossomos/metabolismo , Fatores de Tempo
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