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1.
Eur Radiol ; 24(3): 703-8, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24101237

RESUMO

OBJECTIVE: For hip complaints in the paediatric population, it is common practice to acquire both anteroposterior (AP) and frog-leg lateral (FL) radiographs. This combination of views provides a high diagnostic yield, but also doubles radiation exposure. We investigated the diagnostic accuracy of obtaining a solitary FL view as compared to a combination of the AP and FL view. METHODS: Hip radiographs of 524 children (aged 2-15 years) referred for acute hip pain were retrospectively assessed by two independent radiologists. Cases of trauma, neuromuscular disorders or a history of known hip disease were excluded. Radiologists were blinded to the AP radiograph while assessing the solitary FL radiograph. We used Cohen's kappa test to calculate agreement between the assessment of both views and the solitary FL view. RESULTS: Agreement between the assessment of the solitary FL view and the combination of the AP and FL view was very high with a kappa value of 0.989. CONCLUSION: The diagnostic accuracy of the FL radiograph in cases of hip complaints in children is as high as the current standard employing both AP and FL views. Therefore a solitary FL radiograph appears sufficient. This practice would substantially reduce radiation exposure. KEY POINTS: • Radiation exposure in children should be kept to a minimum. • In paediatric hip radiography a solitary frog-leg lateral view suffices. • This reduces radiation exposure and costs of imaging.


Assuntos
Artralgia/diagnóstico por imagem , Artrografia/métodos , Articulação do Quadril/diagnóstico por imagem , Perna (Membro)/diagnóstico por imagem , Doença de Legg-Calve-Perthes/diagnóstico por imagem , Adolescente , Artrografia/estatística & dados numéricos , Criança , Pré-Escolar , Epífises/diagnóstico por imagem , Feminino , Fêmur/diagnóstico por imagem , Humanos , Masculino , Variações Dependentes do Observador , Posicionamento do Paciente/métodos , Doses de Radiação , Estudos Retrospectivos
2.
Nutr Metab Cardiovasc Dis ; 23(5): 466-72, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-22366195

RESUMO

BACKGROUND AND AIMS: Ectopic artery calcification has been documented in women with postmenopausal osteoporosis, in whom an imbalance in the number of circulating osteoprogenitor cells (OPCs) has been identified. Circulating OPCs form calcified nodules in vitro; however, it remains unknown whether an association exists between the number of circulating OPCs and aortic calcifications. We investigated the relationship between OPCs and aortic calcifications in women with postmenopausal osteoporosis. METHODS AND RESULTS: The number of circulating OPCs was quantified by FACS analysis in 50 osteoporotic postmenopausal women. OPCs were defined as CD15-/alkaline-phosphatase(AP)+ cells coexpressing or not CD34. Participants underwent measurement of markers of bone metabolism, bone mineral density and abdominal aortic calcium (AAC) by 64-slice computed tomography. Patients with AAC were older, had lower 25(OH)vitamin D levels and higher circulating CD15-/AP+/CD34- cells than those without AAC. Significant correlates of AAC included age (rho = 0.38 p = 0.006), calcium (rho = 0.35 p = 0.01), 25(OH)vitamin D (rho = -0.31, p = 0.03) and the number of CD15-/AP+/CD34- cells (rho = 0.55 p < 0.001). In regression analyses, the log-transformed number of CD15-/AP+/CD34- cells was associated with the presence (OR = 6.45, 95% CI 1.03-40.1, p = 0.04) and severity (ß = 0.43, p < 0.001) of AAC, independent of age, 25(OH)vitamin D, calcium and other potential confounders. Patients with low 25(OH)vitamin D and high CD15-/AP+/CD34- cells had higher median AAC than other patients (1927/µL, 862-2714/µL vs 147/µL, 0-1665/µL, p = 0.003). CONCLUSION: In women with postmenopausal osteoporosis, the number of circulating CD15-/AP+/CD34- cells is significantly associated with increased aortic calcifications, that appear to be correlated also with reduced 25(OH)vitamin D levels.


Assuntos
Estenose da Valva Aórtica/fisiopatologia , Valva Aórtica/patologia , Calcinose/fisiopatologia , Osteoblastos/metabolismo , Osteoporose Pós-Menopausa/fisiopatologia , Células-Tronco/metabolismo , Idoso , Fosfatase Alcalina/sangue , Antígenos CD34/sangue , Aorta Abdominal/metabolismo , Aorta Abdominal/fisiopatologia , Valva Aórtica/fisiopatologia , Estenose da Valva Aórtica/complicações , Biomarcadores/sangue , Densidade Óssea/efeitos dos fármacos , Osso e Ossos/citologia , Osso e Ossos/metabolismo , Calcinose/complicações , Cálcio/sangue , Estudos Transversais , Feminino , Fucosiltransferases/sangue , Humanos , Antígenos CD15/sangue , Pessoa de Meia-Idade , Osteoporose Pós-Menopausa/complicações , Pós-Menopausa , Análise de Regressão , Células-Tronco/citologia , Vitamina D/sangue , Deficiência de Vitamina D/complicações , Deficiência de Vitamina D/fisiopatologia
3.
Front Physiol ; 14: 1164943, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37228822

RESUMO

Introduction: Recent research highlights the need for a correct instrument for monitoring the individual health status, especially in the elderly. Different definitions of biological aging have been proposed, with a consistent positive association of physical activity and physical fitness with decelerated aging trajectories. The six-minute walking test is considered the current gold standard for estimating the individual fitness status in the elderly. Methods: In this study, we investigated the possibility of overcoming the main limitations of assessing fitness status based on a single measure. As a result, we developed a novel measure of fitness status based on multiple fitness tests. In 176 Sardinian individuals aged 51-80 years we collected the results of eight fitness tests to measure participants' functional mobility, gait, aerobic condition, endurance, upper and lower limb strength, and static and dynamic balance. In addition, the participants' state of health was estimated through validated risk scores for cardiovascular diseases, diabetes, mortality, and a comorbidity index. Results: Six measures contributing to fitness age were extracted, with TUG showing the largest contribution (beta = 2.23 SDs), followed by handgrip strength (beta = -1.98 SDs) and 6MWT distance (beta = -1.11 SDs). Based on fitness age estimates, we developed a biological aging measure using an elastic net model regression as a linear combination of the results of the fitness tests described above. Our newly developed biomarker was significantly associated with risk scores for cardiovascular events (ACC-AHA: r = 0.61; p = 0.0006; MESA: r = 0.21; p = 0.002) and mortality (Levine mortality score: r = 0.90; p = 0.0002) and outperformed the previous definition of fitness status based on the six-minute walking test in predicting an individual health status. Discussion: Our results indicate that a composite measure of biological age based on multiple fitness tests may be helpful for screening and monitoring strategies in clinical practice. However, additional studies are needed to test standardisation and to calibrate and validate the present results.

4.
Eur Rev Med Pharmacol Sci ; 26(11): 4069-4073, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35731077

RESUMO

OBJECTIVE: Osteomyelitis is a relatively understudied disease with no standardized and evidence-based approach to treatment. We aimed to evaluate a cohort of patients with osteomyelitis, comparing the outcomes between intravenous (IV) and oral treatment. PATIENTS AND METHODS: We performed an observational retrospective study on osteomyelitis cases in adult patients seen for care between 2017 and 2019. We collected information on patient characteristics, microbiological etiology, infection treatment, and outcome. In addition, we divided osteomyelitis cases by antibiotic regimens [oral (OTG) vs. intravenous±oral (ITG)] and therapy durations to evaluate outcomes differences. RESULTS: A total of 235 episodes of osteomyelitis were evaluated, with a higher prevalence in male gender. Staphylococci, especially S. aureus, were the most common strains. Out of the 235 evaluated episodes, we selected 142 cases. Of these, 75 were treated with OTG and 67 with ITG. Gram-positive bacteria were the most frequent aetiological agents, with 81 isolates (61.8%). Full recovery was observed in 79 (55.6%) cases; of these, 36 (53.7%) were in the ITG and 43 (57.3%) in the OTG (p = 0.666). At the logistic regression, a polymicrobial infection [OR 4.16 (95%CI 1.28-13.4), p = 0.017] and a less than six weeks treatment duration [OR 4.24 (95%CI 1.38-5.43) p = 0.004] were significantly associated with a higher risk of treatment failure. CONCLUSIONS: Our study suggests that oral treatment efficacy is comparable to ITG therapy for osteomyelitis, confirming the most recent evidence suggesting that oral therapy is non-inferior to intravenous therapy to treat osteomyelitis.


Assuntos
Infecções Bacterianas , Osteomielite , Administração Oral , Adulto , Antibacterianos , Infecções Bacterianas/tratamento farmacológico , Humanos , Masculino , Osteomielite/tratamento farmacológico , Osteomielite/microbiologia , Estudos Retrospectivos , Staphylococcus aureus
5.
Clin Neurophysiol ; 130(9): 1511-1519, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31295720

RESUMO

OBJECTIVE: To provide normative data for the Vestibulo-Masseteric Reflex (VMR) and Acoustic-Masseteric Reflex (AMR) in healthy subjects, stratified for age and gender. METHODS: A total of 82 healthy subjects (M:F 43:39, mean age 39.3 ±â€¯18.4 years, range 13-79 years) underwent recording of click-evoked VMR and AMR (0.1 ms duration, 5 Hz frequency) from active masseter muscles. Masseter responses to uni- and bilateral stimulation were recorded in a zygomatic and a mandibular configuration, according to the position of the reference electrode. Stimulation intensity curves were recorded for each reflex in ten subjects (mean age 20.7 ±â€¯8.1 years). Gender effect was investigated in 62 subjects and age effect was analyzed in six 10-subject groups aged from <25 to >65 years. Onset and peak latencies, interpeak intervals, raw and corrected amplitudes, latency and amplitude asymmetries were analyzed. RESULTS: VMR had a higher elicitation rate than AMR. For both reflexes, rates of elicitation, and corrected amplitudes were higher in the zygomatic configuration, and bilateral stimulation elicited larger responses. Best acoustic ranges of elicitation were 98-113 dB for AMR and 128-138 dB for VMR. Reflex latencies were shorter in females than males. Frequency and amplitude of VMR and AMR decreased substantially over 55 year olds. CONCLUSIONS: VMR and AMR can be easily performed in any clinical neurophysiology laboratory. SIGNIFICANCE: These reflexes can find application in the investigation of brainstem function in central neurological disorders.


Assuntos
Fatores Etários , Músculo Masseter/fisiologia , Reflexo Acústico/fisiologia , Fatores Sexuais , Potenciais Evocados Miogênicos Vestibulares/fisiologia , Adolescente , Adulto , Idoso , Tronco Encefálico/fisiologia , Eletrodos Implantados , Eletromiografia/métodos , Feminino , Humanos , Masculino , Mandíbula , Pessoa de Meia-Idade , Adulto Jovem , Zigoma
6.
J Cyst Fibros ; 15(6): 816-824, 2016 11.
Artigo em Inglês | MEDLINE | ID: mdl-27049043

RESUMO

BACKGROUND: Sinonasal pathology in adults with Cystic Fibrosis (CF) is common but the extent of CT-abnormalities and symptoms of sinonasal disease in children with CF and the age of onset are less frequently studied. METHODS: In this observational, cross-sectional study 58 children with CF from two CF centres were included. All subjects completed a questionnaire regarding sinonasal symptoms, underwent a CT scan of the paranasal sinuses, and in each subject a culture of the upper airways was performed. Subjects were divided in 6 age cohorts (0-2, 3-5, 6-8, 9-11, 12-14 and 15-17years) and were divided into severe and mild CF based on their CFTR mutation. Opacification of the sinonasal system of the subjects was compared with opacification on MRI-scans of an age-matched control group without CF. RESULTS: Most frequently reported symptoms were nasal obstruction and posterior/anterior nasal discharge. Opacification was abundant in every age cohort of the study group and was significantly more compared to the control group. In patients with severe CF the opacification was higher than subjects with mild CF. Upper airway cultures showed predominantly Staphylococcus aureus, Haemophilus influenzae and Pseudomonas aeruginosa. CONCLUSION: CT-abnormalities indicating sinonasal disease and symptoms are present from shortly after birth which may argue for a thorough examination of the upper airways in children with CF.


Assuntos
Fibrose Cística , Haemophilus influenzae/isolamento & purificação , Obstrução Nasal , Seios Paranasais , Pseudomonas aeruginosa/isolamento & purificação , Sinusite , Staphylococcus aureus/isolamento & purificação , Tomografia Computadorizada por Raios X/métodos , Adolescente , Idade de Início , Criança , Pré-Escolar , Estudos Transversais , Fibrose Cística/diagnóstico , Fibrose Cística/epidemiologia , Fibrose Cística/genética , Fibrose Cística/fisiopatologia , Regulador de Condutância Transmembrana em Fibrose Cística/genética , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Mutação , Obstrução Nasal/diagnóstico , Obstrução Nasal/etiologia , Países Baixos/epidemiologia , Seios Paranasais/diagnóstico por imagem , Seios Paranasais/microbiologia , Sinusite/complicações , Sinusite/diagnóstico , Sinusite/microbiologia , Sinusite/fisiopatologia , Estatística como Assunto , Avaliação de Sintomas/métodos
7.
J Immunol Methods ; 256(1-2): 141-52, 2001 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-11516761

RESUMO

Intracellular expression of human myxovirus protein A (MxA) is exclusively induced by type I IFNs (IFNalpha,beta,omega) or by some viruses and it is strongly increased under IFN treatment. We set up an internally controlled quantitative-competitive polymerase chain reaction (qc-PCR) that quantifies MxA mRNA expressed in human peripheral blood mononuclear cells (PBMC). Our qc-PCR is accurate because the mean ratio of copy number estimated by qc-PCR to that quantified spectrophotometrically is 1.08+/-0.03, moreover it is repeatable with high sensitivity (1 fg MxA/pg GAPDH). MxA mRNA was tested in 47 Relapsing-Remitting Multiple Sclerosis (RR-MS) untreated patients and in 48 patients treated with one of the 3 IFNbeta licensed for MS (24 with Rebif, 14 with Avonex and 10 with Betaferon). All the 48 treated patients were negative to IFNbeta neutralising antibodies (NABs) as tested in our laboratory using a cytopathic assay (CPE). MxA mRNA levels were detectable in all untreated patients (mean 24+/-18 fg MxA/pg GAPDH) and significantly higher levels were found in all the treated patients 12 h after IFNbeta administration (mean 499+/-325 fg MxA/pg GAPDH); furthermore, the three types of IFNbeta showed comparable bioavailability. Our data indicate that the bioavailability of the three available types of IFNbeta can be evaluated by MxA qc-PCR.


Assuntos
Proteínas de Ligação ao GTP , Interferon beta/farmacologia , Esclerose Múltipla/tratamento farmacológico , Reação em Cadeia da Polimerase/métodos , Proteínas/genética , Humanos , Leucócitos Mononucleares/imunologia , Esclerose Múltipla/imunologia , Proteínas de Resistência a Myxovirus , Biossíntese de Proteínas , RNA Mensageiro/biossíntese , Reprodutibilidade dos Testes , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Sensibilidade e Especificidade
8.
Neuroscience ; 74(1): 155-9, 1996 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-8843084

RESUMO

The effects of chronic alcohol consumption on memory performance and hippocampal acetylcholine release in vivo were investigated in rats. Rats were allowed to drink 25% (v/v) ethanol solution as the only source of fluid for nine consecutive months, whereas control rats received only tap water. Memory performance was tested by the acquisition of shuttle box active and passive avoidance. Chronic ethanol-consuming rats were not impaired in the acquisition of the active avoidance response task, whereas in the passive avoidance task, latency scores of treated rats were significantly lower than in controls. The basal release of acetylcholine in freely moving rats, assessed by the microdialysis technique, was significantly decreased in ethanol-treated rats. Impairment in memory performance, as assessed in the passive avoidance task, was significantly correlated with hippocampal acetylcholine release in vivo.


Assuntos
Acetilcolina/metabolismo , Etanol/farmacologia , Hipocampo/efeitos dos fármacos , Memória/efeitos dos fármacos , Animais , Masculino , Ratos , Ratos Sprague-Dawley , Fatores de Tempo
9.
Br J Pharmacol ; 104(3): 573-4, 1991 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-1797320

RESUMO

The neurotoxin MPP+ potently inhibited the striatal binding of [3H]-tyramine, a putative marker for the vesicular transporter of dopamine, and provoked a massive in vivo release of striatal dopamine. Tetrabenazine, an established ligand for the vesicular catecholamine carrier, potently inhibited [3H]-tyramine binding, tyramine-provoked striatal efflux of dopamine and the fast component of MPP(+)-induced dopamine release. It is concluded that MPP+ in the striatum, besides interacting with additional intracellular targets, avidly binds at a vesicular site functionally involved with the outward transport of dopamine.


Assuntos
Corpo Estriado/metabolismo , Dopamina/metabolismo , Glicoproteínas de Membrana , Proteínas de Membrana Transportadoras , Proteínas do Tecido Nervoso , Compostos de Piridínio/farmacologia , Tiramina/farmacologia , Animais , Proteínas de Transporte/metabolismo , Corpo Estriado/efeitos dos fármacos , Diálise , Proteínas da Membrana Plasmática de Transporte de Dopamina , Técnicas In Vitro , Masculino , Ratos , Ratos Endogâmicos , Tetrabenazina/farmacologia , Tiramina/metabolismo
10.
Neuroreport ; 7(4): 869-72, 1996 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-8724663

RESUMO

The effect of tetanic intracortical microstimulation (ICMS) of superficial layers of the motor cortex on unit discharges responding to stimulation of the peripheral receptive fields was examined in the motor cortex (area 4y). Single or multiple unit discharges were isolated from 15 recording sites near the stimulating electrodes. Following tetanic ICMS, the response to the same peripheral stimulation showed a long lasting increase at six recording sites, a long lasting decrease at two sites and transient increase or decrease at four sites. In the rest of the sites, tetanic ICMS had no effect. The results demonstrate the existence of use-dependent modification of information processing in the motor cortex and support the hypothesis that the motor cortex participates in learning motor skills.


Assuntos
Córtex Motor/citologia , Neurônios/fisiologia , Animais , Gatos , Estimulação Elétrica , Feminino , Masculino , Tetania , Fatores de Tempo
11.
Neuroreport ; 12(11): 2353-8, 2001 Aug 08.
Artigo em Inglês | MEDLINE | ID: mdl-11496109

RESUMO

Synaptic plasticity was studied in the lateral vestibular nuclei (LVN) of the guinea pig in vivo. High frequency stimulation (HFS) of increasing or decreasing frequencies was applied to the ipsilateral vestibular nerve. Vestibular field potentials (VFPs) and extracellular single unit activity evoked in the LVN by electrical stimulation of the ipsilateral vestibular nerve, were analyzed before and after the application of different protocols of HFS. Results show that the monosynaptic component of the VFPs undergo long-term potentiation (LTP) with stimulation of 100 Hz applied for 20 s lower frequencies, applied for shorter periods, induce only a transient post-tetanic potentiation. This potentiation, although long lasting, is not permanent since it is susceptible of a reversal or cancellation by opposite patterns of HFS that determine a depression or depotentiation of the previously acquired potentiation. The results demonstrate that the plasticity phenomena that take place at the level of the LVN neurons are not steady but undergo continuous adjustment of their sign and gain depending on the variable flow of vestibular information that reach the nuclei from the labyrinthine receptors.


Assuntos
Potenciação de Longa Duração/fisiologia , Inibição Neural/fisiologia , Núcleo Vestibular Lateral/fisiologia , Animais , Estimulação Elétrica , Potenciais Evocados Auditivos/fisiologia , Feminino , Cobaias , Masculino , Plasticidade Neuronal/fisiologia , Nervo Vestibulococlear/fisiologia
12.
Neuroreport ; 5(17): 2372-6, 1994 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-7881061

RESUMO

Synaptic plasticity in the motor cortex of anesthetized cats was examined using intracellular recording and labeling techniques. Intracortical microstimulation (ICMS) was delivered in the superficial layers and recordings were made from cells in layer V. When the neuron responded to ICMS with an excitatory postsynaptic potential (EPSP), tetanic ICMS (100-200 Hz, 10-20 s) was delivered to the same site. Five of 19 cells which were examined and labeled with biocytin showed long-term potentiation (LTP) of the EPSP, and 12 cells showed post-tetanic potentiation (PTP) following the tetanic stimulation. All the examined cells were pyramidal neurons. These results demonstrate that plasticity exists within the intracortical connection of the motor cortex that may be involved in motor learning.


Assuntos
Potenciação de Longa Duração , Córtex Motor/fisiologia , Animais , Gatos , Estimulação Elétrica , Feminino , Masculino , Córtex Motor/citologia , Neurônios/fisiologia , Tempo de Reação
13.
Neuroreport ; 7(14): 2303-7, 1996 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-8951843

RESUMO

Long-term potentiation (LTP) was studied in the lateral vestibular nucleus (LVN-Deiters' nucleus) in guinea-pigs in vivo. Field potentials and extracellular single unit discharges were recorded in the LVN following electrical stimulation of the ipsilateral VIIIth nerve. High-frequency stimulation (HFS) of the VIIIth nerve fibres produced LTP of the monosynaptic component of the vestibular field potential. The LTP of the field potentials was paralleled by an increase of the evoked spike activity. Intranuclear administration of the NMDA antagonist MK-801 prevented LTP of the monosynaptic component of the vestibular field potentials and significantly suppressed the spontaneous firing of lateral vestibular neurones in a dose-dependent fashion. These results demonstrate that synapses between primary afferent fibres and second order LVN neurones undergo long lasting changes following HFS of the ipsilateral vestibular nerve.


Assuntos
Cobaias/fisiologia , Potenciação de Longa Duração , Núcleo Vestibular Lateral/fisiologia , Animais , Maleato de Dizocilpina/farmacologia , Estimulação Elétrica , Antagonistas de Aminoácidos Excitatórios/farmacologia , Feminino , Potenciação de Longa Duração/efeitos dos fármacos , Masculino , Núcleo Vestibular Lateral/efeitos dos fármacos , Nervo Vestibulococlear/fisiologia
14.
Brain Res ; 762(1-2): 269-74, 1997 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-9262189

RESUMO

We assessed whether consumption of a diet lacking in tryptophan (TRP) resulted in alteration in learning and memory performance and hippocampal 5-HT release in rats. Two hours after the acute administration of TRP-free (T) and balanced (B) diet rats were trained in a one-trial passive avoidance task. The two groups of rats showed no significant difference in retention latencies. Two other groups of rats, fed with the above diets during the acquisition of a radial-arm maze task, showed no difference in baseline performance. The acute ingestion of the T diet produced a significant and long lasting decrease of hippocampal and cortical 5-HT release in rats when compared to the B diet, while the 12th day of the T diet, 5-HT was not detectable in the dialysate. These data indicate that the diminished brain release of 5-HT induced by a T diet is not sufficient to impair cognitive processes.


Assuntos
Aprendizagem da Esquiva/efeitos dos fármacos , Serotonina/metabolismo , Comportamento Espacial/efeitos dos fármacos , Triptofano/farmacologia , Animais , Córtex Cerebral/química , Córtex Cerebral/metabolismo , Dieta , Hipocampo/química , Hipocampo/metabolismo , Masculino , Aprendizagem em Labirinto/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley
15.
Eur J Pharmacol ; 307(2): R1-2, 1996 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-8832228

RESUMO

In this study we examined whether the food-reinforced alternation performance was associated with increased acetylcholine output in the dorsal hippocampus. Rats were trained to acquire the task using a T-maze. The control group consisted of rats introduced into the T-maze to run only on the day of dialysis. Acetylcholine release increased significantly in control rats only in the first 10 min after they were put into the T-maze. In trained rats acetylcholine output increased in the waiting cage as well as during trials in the T-maze. The increase in acetylcholine output in rats that had learned the task was significantly greater than in control rats.


Assuntos
Acetilcolina/metabolismo , Hipocampo/metabolismo , Aprendizagem em Labirinto/fisiologia , Memória/fisiologia , Acetilcolina/análise , Animais , Cromatografia Líquida de Alta Pressão , Hipocampo/química , Masculino , Microdiálise , Ratos , Ratos Sprague-Dawley , Reforço Psicológico
16.
Neurosci Lett ; 117(1-2): 129-33, 1990 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-1981252

RESUMO

The concentrations of dopamine (DA) and of the excitatory amino acids (EAAs) glutamate (Glu) and aspartate (Asp) were measured in dialysates from the striatum of awake rats in order to study the link between the release of DA and of EAAs induced by the infusion of 1-methyl-4-phenylpyridinium ion (MPP+). DA and EAAs were detected simultaneously by HPLC-EC. The infusion of MPP+ at the concentration of 1 mM elevated DA levels in the perfusates, but did not affect EAA release. However, MPP+ at 10 mM maximally stimulated Glu and Asp release to 230- and 68-fold of baseline, respectively. In this condition, pretreatment with the N-methyl-D-aspartate (NMDA) receptor antagonist MK-801 (5 mg/kg, i.p.) prevented the MPP(+)-induced EAA release. In contrast, MK-801 had no effect on DA release induced either by 1 or 10 mM MPP+. These results suggest that MPP(+)-induced DA and EAA release are independently regulated processes. In addition, the finding that MK-801 inhibits MPP(+)-induced EAA release suggests that EAAs may act on NMDA receptors to stimulate their own release through a positive-feedback mechanism.


Assuntos
1-Metil-4-fenilpiridínio/farmacologia , Ácido Aspártico/metabolismo , Corpo Estriado/fisiologia , Maleato de Dizocilpina/farmacologia , Glutamatos/metabolismo , Animais , Corpo Estriado/efeitos dos fármacos , Dopamina/metabolismo , Ácido Glutâmico , Cinética , Masculino , Ratos , Ratos Endogâmicos
17.
Brain Res Bull ; 28(2): 239-44, 1992 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-1596744

RESUMO

The experiments were designed to show whether visual inputs and somatosensory signals travelling along the common radial nerves converge onto the same hypoglossal neurons. The hypoglossal neurons (HN) type I (45.77%) and II (33.89%) responded to both visual and somatosensory stimuli. The HN type III (15.26%) responded only to the retinae and type IV (5.08%) only to the forelimb nerves stimulation. In the convergent neurons, types I and II, the influence of the somatosensory stimulation on the hypoglossal visual response was also analyzed. The conditioning stimulation of the radial nerve significantly increased (31%) the hypoglossal response to the less effective retina and significantly reduced (17%) the response to the more effective retina. The recordings of the electromyographic activity of the genioglossus (GM) and the superior longitudinal muscle (SLM), showed that the somatosensory afferents synergize the excitatory effect of the visual messages on the extrinsic tongue muscles (GM) and antagonize the inhibitory effect that visual messages induce on the intrinsic tongue muscles (SLM). The results suggest that visual messages induce tongue reflex responses functionally directed not only to prepare the oral cavity better for food reception, as previously demonstrated, but also to modulate the postural tone of the tongue together with somatosensory signals.


Assuntos
Membro Anterior/inervação , Nervo Hipoglosso/fisiologia , Neurônios Motores/fisiologia , Nervo Radial/fisiologia , Retina/fisiologia , Língua/inervação , Visão Ocular/fisiologia , Animais , Estimulação Elétrica , Lateralidade Funcional , Neurônios/fisiologia , Coelhos
18.
Brain Res Bull ; 33(1): 7-16, 1994.
Artigo em Inglês | MEDLINE | ID: mdl-8275326

RESUMO

The rabbit hypoglossal neurons, localized in the mediocaudal part of the XIIth nucleus, receive visual and vestibular inputs able to induce reflex responses functionally driven both to prepare the oral cavity for food reception and to ensure a correct postural arrangement of the tongue. The aim of the present research was to show a possible convergence of visual input on the hypoglossal neurons modulated by the vestibular system and, thus, demonstrate that visual input plays a part in the control of the tongue posture. It was found that 78% of tested neurons responded to both photic stimulation of the retinae, performed by a conventional strobe unit, and electrical stimulation of the labyrinth, with different patterns of response. Moreover, visual input significantly modified both the hypoglossal neuron response and the electromyographic genioglossal response to caloric stimulation of the labyrinth. Because a significant visual influence on the hypoglossal nucleus response and the genioglossal muscle response to labyrinthine stimulation was observed, it can be concluded that vision does integrate the spatial information of the labyrinth to modulate the postural tone of the tongue muscles.


Assuntos
Nervo Hipoglosso/fisiologia , Neurônios Motores/fisiologia , Língua/inervação , Vestíbulo do Labirinto/fisiologia , Animais , Orelha Interna/fisiologia , Estimulação Elétrica , Eletromiografia , Potenciais Evocados/fisiologia , Temperatura Alta , Nervo Hipoglosso/citologia , Músculos/inervação , Músculos/fisiologia , Vias Neurais/citologia , Vias Neurais/fisiologia , Estimulação Luminosa , Coelhos , Retina/fisiologia , Vias Visuais/citologia , Vias Visuais/fisiologia
19.
Brain Res Bull ; 20(1): 83-8, 1988 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-3342343

RESUMO

Evoked potentials and responses of single hypoglossal neurons were recorded in response to electrical stimulation of the labyrinth. In addition, the spontaneous electrical activity of hypoglossal neurons was significantly modified in response to ipsi- and contralateral static tilt of the whole animal and thermic stimulation of the labyrinth. The experiment showed that the labyrinth modulates the electrical activity of hypoglossal neurons with phasic inputs in response to ampullar stimulation and with tonic inputs in response to macular stimulation. The vestibular phasic influence of hypoglossal neurons represents the most adequate functional pattern to obtain a quick, short lasting response of the tongue muscles instantly modifiable with every abrupt head displacement. On the contrary, the vestibular tonic influence of hypoglossal neurons represents the most adequate functional pattern to obtain not only adjustment but also maintenance of the muscular lingual response to static displacement of the head.


Assuntos
Vias Auditivas/fisiologia , Orelha Interna/fisiologia , Nervo Hipoglosso/fisiologia , Animais , Tronco Encefálico/fisiologia , Estimulação Elétrica , Potenciais Evocados , Temperatura Alta , Neurônios/fisiologia , Coelhos
20.
Brain Res Bull ; 55(2): 269-75, 2001 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-11470326

RESUMO

The effects of lead exposure at low concentrations were evaluated by studying the post-rotatory nystagmus (PRN) in two groups of rats exposed for 3 months to 50 parts per million (ppm) of sodium acetate and 50 ppm of lead acetate, respectively, in the drinking water. Only animals treated with lead acetate showed changes of the PRN parameters which were significantly related to the concentration of lead in the blood and in brain structures. The patterns of PRN responses were characterized and classified into four types: progressively inhibitory (40%), prematurely inhibitory (25%), late inhibitory (25%), and excitatory-inhibitory (10%). No alterations of the PRN parameters were observed in the animals treated with sodium acetate. The results show that exposure to lead, even at low concentrations, impairs both sensory and motor functions. The findings also point out that the vestibular system and brain stem structures which generate and control the PRN represent targets of the action of this heavy metal. Finally, the results indicate that the evaluation of the vestibulo-ocular-reflex can provide a test suited for the screening of the neurotoxic effects of lead even in the absence of clinical signs typical of lead intoxication.


Assuntos
Intoxicação do Sistema Nervoso por Chumbo/fisiopatologia , Chumbo/toxicidade , Neurotoxinas/toxicidade , Nistagmo Fisiológico/efeitos dos fármacos , Reflexo Vestíbulo-Ocular/efeitos dos fármacos , Núcleos Vestibulares/efeitos dos fármacos , Animais , Relação Dose-Resposta a Droga , Exposição Ambiental/efeitos adversos , Feminino , Intoxicação do Sistema Nervoso por Chumbo/patologia , Masculino , Nistagmo Fisiológico/fisiologia , Ratos , Ratos Long-Evans , Reflexo Vestíbulo-Ocular/fisiologia , Núcleos Vestibulares/patologia , Núcleos Vestibulares/fisiopatologia , Poluentes Químicos da Água/toxicidade
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