Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 11 de 11
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Georgian Med News ; (140): 39-43, 2006 Nov.
Artigo em Russo | MEDLINE | ID: mdl-17179586

RESUMO

Physiological intracranial calcification occurs in about 0,3-1,5% of cases. It is asymptomatic and is detected incidentally by neuroimaging. Pathological basal ganglia calcification is due to various causes, such as: metabolic disorders, infectious and genetic diseases and other. Hypoparathyroidism and pseudohypoparathyroidism are the most common causes of pathological basal ganglia calcification. Besides tetany and seizures this condition is presented by parkinsonism and dementia. Such parkinsonism doesn't respond to drugs containing levodopha. Infections (toxoplasmosis, rubella, cytomegalovirus, cysticercosis, AIDS) give multiple and asymmetric intracranial calcification. Inherited and neurodegenerative diseases cause symmetrical, bilateral basal ganglia calcification which is not related to metabolic disorders (blood calcium level and other), those are: Cockayne syndrome, tuberous sclerosis, Fahr's syndrome, Down syndrome and other. We observed some cases of basal ganglia calcification and studied clinical manifestations and treatment tolerance of this pathological condition. Since adequate treatment of hypoparathyroidism may lead to marked clinical improvement, serum concentration of calcium, phosphorus, and parathyreoid hormone is suggested to be determined in all individuals with calcification of the basal ganglia to rule out hypoparathyroidism. Basal ganglia calcification in young patient with acute hepatitis may be result of Wilson disease.


Assuntos
Doenças dos Gânglios da Base/diagnóstico por imagem , Gânglios da Base/diagnóstico por imagem , Calcinose/diagnóstico por imagem , Tomografia Computadorizada por Raios X/métodos , Adolescente , Adulto , Idoso , Diagnóstico Diferencial , Feminino , Humanos , Masculino , Índice de Gravidade de Doença
2.
J Neurophysiol ; 91(5): 2090-100, 2004 May.
Artigo em Inglês | MEDLINE | ID: mdl-15069099

RESUMO

Vestibulospinal reflexes play an important role for body stabilization during locomotion and for postural control. For an appropriate distribution of vestibular signals to spinal motoneurons, the orientation of the body relative to the head needs to be taken into account. For different trunk positions, identical vestibular stimuli must activate different sets of muscles to ensure body stabilization. Because the cerebellar vermis and the underlying fastigial nucleus (FN) might be involved in this task, vestibular neurons in the rostral FN of alert rhesus monkeys were recorded during sinusoidal vestibular stimulation (0.1-1.0 Hz) in the roll and pitch planes at different trunk-re-head positions (center and +/-45 degrees ). From the sensitivity and phase values measured in these planes, the response properties in the intermediate planes and the stimulus orientation eliciting the optimal response [response vector orientation (RVO)] were calculated. In most neurons, the RVOs rotated systematically with respect to the head, when trunk-re-head position was altered, so that they tended to maintain their orientation with respect to the trunk. Sensitivity and phase at the RVO were not affected. This pattern was the same for neurons in the right and left FN and independent of stimulus frequency. The average sensitivity of this partially compensatory RVO shift in response to trunk-re-head displacements, evaluated by linear regression analyses, was 0.59 degrees / degrees (n = 73 neurons). These data show that FN neurons may encode vestibular information in a coordinate system that is closer to a trunk-centered than to a head-centered reference frame. They indicate an important role of this nucleus in motor programs related to posture and gait control.


Assuntos
Núcleos Cerebelares/citologia , Núcleos Cerebelares/fisiologia , Neurônios/fisiologia , Postura/fisiologia , Tórax/fisiologia , Vestíbulo do Labirinto/fisiologia , Animais , Estimulação Elétrica , Eletrodos Implantados , Lateralidade Funcional/fisiologia , Movimentos da Cabeça/fisiologia , Macaca mulatta , Pescoço/fisiologia , Orientação/fisiologia , Estimulação Física , Rotação
3.
Ann N Y Acad Sci ; 1004: 241-51, 2003 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-14662463

RESUMO

The rostral fastigial nucleus contains vestibular neurons, which presumably are involved in spinal mechanisms (neck, gait, posture) and which are not modulated with individual eye movements. Single-unit recordings in the alert behaving monkey during natural stimulus conditions reveal that virtually all neurons demonstrate integration of several sensory inputs. This applies not only for canal-canal and canal-otolith interaction, but also for otolith-otolith interaction. There is also some evidence that most neurons receive not only an utriculus but also a sacculus input. Furthermore, most neurons also respond to large-field optokinetic stimulation, reflecting visual-vestibular interaction. Neurons are also affected by the head on trunk position, which would allow these neurons to operate in a body-centered rather than a head-centered reference frame. These complex, multisensory features could permit fastigial nucleus neurons to rather specifically affect spinal motor functions.


Assuntos
Núcleos Cerebelares/fisiologia , Neurônios Motores/fisiologia , Núcleos Vestibulares/fisiologia , Animais , Movimentos da Cabeça/fisiologia , Macaca , Membrana dos Otólitos/fisiologia , Postura/fisiologia , Reflexo Vestíbulo-Ocular/fisiologia , Rotação , Canais Semicirculares/fisiologia
4.
Exp Brain Res ; 136(2): 169-78, 2001 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-11206279

RESUMO

To determine the contribution of the otoliths as well as the horizontal and vertical semicircular canals to the response of "vestibular only" neurons in the rostral fastigial nucleus of the alert monkey, we applied natural sinusoidal vestibular stimuli (0.6 Hz; +/-15 deg) around different axes. During the experiment the monkey sat erect in a primate chair with the head immobile. Semicircular canal responses were investigated during tilted yaw stimulation around an earth vertical axis. The tilt angle was varied by 30 deg and included the optimal plane for horizontal canal stimulation (15 deg nose down from the stereotactic plane). The otoliths and mainly the vertical canals made contributions during stimulation around an earth-fixed horizontal axis (vertical stimulation). Head orientation was also slowly altered (2-3 deg/s) over a range of 180 deg under both stimulus conditions (tilted yaw and vertical stimulation). Neuronal data for each paradigm were fitted by a least squares best-sine function. Computation of the hypothetical contributions made by all three pairs of semicircular canals and the otoliths to these responses showed that 74% of the 46 neurons investigated received an otolith input; in most instances it was combined with a canal input. Neurons most often received input from the horizontal and vertical canals as well as the otoliths. Only a minority of neurons received a purely otolith (13%), vertical canal (13%), or horizontal canal (4%) input. Conventional criteria (head position-related activity, spatiotemporal convergence, STC) failed to detect an otolith contribution in several such instances. Thus, canal-otolith convergence is the general rule at this central stage of vestibular information processing in the fastigial nucleus. The large variety of response types allows these neurons to participate in multiple tasks of vestibulospinal movement control.


Assuntos
Núcleos Cerebelares/fisiologia , Membrana dos Otólitos/fisiologia , Canais Semicirculares/fisiologia , Animais , Nível de Alerta/fisiologia , Movimentos Oculares/fisiologia , Movimentos da Cabeça/fisiologia , Macaca mulatta/fisiologia , Neurônios/fisiologia , Estimulação Física/métodos , Desempenho Psicomotor/fisiologia , Rotação
5.
J Neurophysiol ; 82(1): 34-41, 1999 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-10400932

RESUMO

Neurons in the rostral part of the fastigial nucleus (FN) respond to vestibular stimulation but are not related to eye movements. To understand the precise role of these vestibular-only neurons in the central processing of vestibular signals, unit activity in the FN of alert monkeys (Macaca mulatta) was recorded. To induce vestibular stimulation, the monkey was rotated sinusoidally around an earth-fixed horizontal axis at stimulus frequencies between 0.06 (+/-15 degrees) and 1.4 Hz (+/-7.5 degrees). During stimulation head orientation was changed continuously, allowing for roll, pitch, and intermediate planes of orientation. At a frequency of 0.6 Hz, 59% of the neurons had an optimal response orientation (ORO) and a null response (i.e., no modulation) 90 degrees apart. The phase of neuronal response was constant except for a steep shift of 180 degrees around the null response. This group I response is compatible with a semicircular canal input, canal convergence, or a single otolith input. Several other features indicated more complex responses, including spatiotemporal convergence (STC). 1) For 35% of the responses at 0.6 Hz, phase changes were gradual with different orientations. Fifteen percent of these had a null response (group II), and 20% showed only a minimal response but no null response (group III). The remaining responses (6%), classified as group IV, were characterized by a constant sensitivity at different orientations in most instances. 2) For the vast majority of neurons, the stimulus frequency determined the response group, i.e., an individual neuron could show a group I response at one frequency and a group II (III or IV) response at another frequency. 3) ORO changed with frequency by >45 degrees for 44% of the neurons. 4) Although phase changes at different frequencies were close to head velocity (+/-45 degrees ) or head position (+/-45 degrees ) for most neurons, they exceeded 90 degrees for 29% of the neurons between 0.1 and 1.0 Hz. In most cases, this was a phase advance. The change in sensitivity with change in frequency showed a similar pattern for all neurons; the average sensitivity increased from 1.24 imp. s-1. deg-1 at 0.1 Hz to 2.97 imp. s-1. deg-1 at 1.0 Hz. These data demonstrate that only an analysis based on measurements at different frequencies and orientations reveals a number of complex features. They moreover suggest that for the vast majority of neurons several sources of canal and otolith information interact at this central stage of vestibular information processing.


Assuntos
Núcleos Cerebelares/fisiologia , Neurônios/fisiologia , Orientação/fisiologia , Vestíbulo do Labirinto/fisiologia , Estimulação Acústica , Animais , Estimulação Elétrica , Movimentos Oculares , Macaca mulatta , Postura , Sensibilidade e Especificidade
6.
Ann N Y Acad Sci ; 871: 81-93, 1999 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-10372064

RESUMO

To investigate the otolith contribution to the responses of "vestibular only" neurons in the rostral fastigial nucleus (FN), single-unit activity was recorded in the alert monkey with the head fixed during static and dynamic stimulation (+/- 15 deg, 0.06-1.4 Hz) around an earth-fixed horizontal axis. Head orientation could be altered allowing for roll, pitch, and intermediate planes of orientation. For the vast majority of neurons a response vector orientation (RVO) with an optimal response and a null-response at a head orientation 90 deg apart could be determined. Presumably more than 30% of the vestibular only neurons had an otolith input, as indicated by responses to static tilt, head-position-related activity, large phase changes (> 100 deg) of neuronal activity between 0.06 and 1.4 Hz, changes of the RVO at different frequencies and complex responses (spatio-temporal convergence). Thus, neurons in FN reflecting an otolith or a combined canal-otolith input are much more common than up to now thought. Vestibular-only neurons are most likely involved in vestibulospinal mechanisms. Their precise functional role has yet to be determined.


Assuntos
Núcleos Cerebelares/fisiologia , Membrana dos Otólitos/fisiologia , Animais , Núcleos Cerebelares/citologia , Estimulação Elétrica , Eletrofisiologia , Macaca mulatta , Neurônios/fisiologia , Orientação/fisiologia , Vestíbulo do Labirinto/citologia , Vestíbulo do Labirinto/fisiologia
7.
J Neurophysiol ; 77(3): 1432-46, 1997 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-9084609

RESUMO

The fastigial nucleus (FN) receives vestibular information predominantly from Purkinje cells of the vermis. FN in the monkey can be divided in a rostral part, related to spinal mechanisms, and a caudal part with oculomotor functions. To understand the role of FN during movements in space, single-unit activity in alert monkeys was recorded during passive three-dimensional head movements from rostral FN. Seated monkeys were rotated sinusoidally around a horizontal earth-fixed axis (vertical stimulation) at different orientations 15 degrees apart (including roll, pitch, vertical canal plane and intermediate planes). In addition, sinusoidal rotations around an earth-vertical axis (yaw stimulus) included different roll and pitch positions (+/-10 degrees, +/-20 degrees). The latter positions were also used for static stimulation. One hundred fifty-eight neurons in two monkeys were modulated during the sinusoidal vertical search stimulation. The vast majority showed a uniform response pattern: a maximum at a specific head orientation (response vector orientation) and a null response 90 degrees apart. Detailed analysis was obtained from 111 neurons. On the basis of their phase relation during dynamic stimulation and their response to static tilt, these neurons were classified as vertical semicircular canal related (n = 79, 71.2%) or otolith related (n = 25; 22.5%). Only seven neurons did not follow the usual response pattern and were classified as complex neurons. For the vertical canal-related neurons (n = 79) all eight major response vector orientations (ipsilateral or contralateral anterior canal, posterior canal, roll, and nose-down and nose-up pitch) were found in Fn on one side. Neurons with ipsilateral orientations were more numerous and on average more sensitive than those with contralateral orientations. Twenty-eight percent of the vertical canal-related neurons also responded to horizontal canal stimulation. None of the vertical canal-related neurons responded to static tilt. Otolith-related neurons (n = 25) had a phase relation close to head position and were considerably less numerous than canal-related neurons. Except for pitch, all other response vector orientations were found. Seventy percent of these neurons responding during dynamic stimulation also responded during static tilt. The sensitivity during dynamic stimulation was always higher than during static stimulation. Sixty-one percent of the otolith-related neurons responded also to horizontal canal stimulation. These results show that in FN, robust vestibular signals are abundant. Canal-related responses are much more common than otolith-related responses. Although for many canal neurons the responses can be related to single canal planes, convergence between vertical canals but also with horizontal canals is common.


Assuntos
Movimentos da Cabeça/fisiologia , Núcleos Vestibulares/fisiologia , Animais , Movimentos Oculares/fisiologia , Macaca mulatta , Neurônios/fisiologia , Orientação/fisiologia , Membrana dos Otólitos/inervação , Membrana dos Otólitos/fisiologia , Estimulação Física , Rotação , Canais Semicirculares/inervação , Canais Semicirculares/fisiologia , Núcleos Vestibulares/anatomia & histologia , Núcleos Vestibulares/citologia
9.
Eur J Gynaecol Oncol ; 17(4): 292-5, 1996.
Artigo em Inglês | MEDLINE | ID: mdl-8856309

RESUMO

Endometrial carcinoma incidence in Georgia from 1965 to 1992 was 5.3 women per 100,000 and in the structure of gynecological malignant tumors this pathology occupied third place (19.1%). Morbidity incidence varied from 2 to 8 depending on ethnic regions overall a 2.5 times rise in morbidity was observed. Within the period of 1968-1994 1731 patients with uterine carcinoma were subjected to surgical intervention (stage I-81.2%; stage II-9.4%; stage III-9.0%; stage IV-0.3%). Surgical intervention is the optimal method to determine the stage of the disease and planning of adjuvant treatment. Metastases in regional lymph nodes were found in 13.0% (T1-7.7%; T2-20.07%; T3-35.3%). Adenocarcinoma was histologically confirmed in 97.4% (G1-21.3%; G2-57.8%; G3-18.8%). Management of the disease was predominantly started with surgical intervention. In pathogenetic version I (71.4%) total extirpation of the uterine was carried out, while in cases of the pathogenetic version II (28.6%) patients were subjected to the modified extended extirpation. Postoperative management was prescribed based on the peculiarities of the organism and tumor. Highly sensitive classification of endometrial carcinoma of stage I (including 5 subgroups) as well as a synoptic table of optimal management were worked out. As a result, 5 year survival increased by 15%, and 29% of the women operated were spared from additional treatment. On the whole, five-year-survival was observed in 71.0% of women (stage I-77.7%; Early Form-95.5%; stage II-51.5%; stage III-34.2%).


Assuntos
Neoplasias do Endométrio/epidemiologia , Neoplasias do Endométrio/patologia , Neoplasias do Endométrio/terapia , Feminino , República da Geórgia/epidemiologia , Humanos , Incidência , Metástase Neoplásica , Estadiamento de Neoplasias , Análise de Sobrevida
10.
Gematol Transfuziol ; 35(1): 25-7, 1990 Jan.
Artigo em Russo | MEDLINE | ID: mdl-2328900

RESUMO

Cytogenetic and mitotic disorders were studied in 151 patients with acute non-lymphoblastic leukemia. A significant rise in the incidence of clonal disorders with predominant affection of chromosomes 5 and 7, and an increase in the percentage of cases with the presence of pathologic mitoses in hemopoietic cells have been recorded in patients who, due to their occupation, have been exposed to potentially mutagenic chemical substances.


Assuntos
Poluentes Ocupacionais do Ar/efeitos adversos , Indústria Química , Aberrações Cromossômicas/genética , Cromossomos Humanos Par 5/efeitos dos fármacos , Cromossomos Humanos Par 7/efeitos dos fármacos , Leucemia Mieloide Aguda/genética , Mitose/efeitos dos fármacos , Doenças Profissionais/genética , Humanos , Leucemia Mieloide Aguda/induzido quimicamente , Doenças Profissionais/induzido quimicamente , U.R.S.S.
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...