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1.
Ir Med J ; 113(2): 20, 2020 02 13.
Artigo em Inglês | MEDLINE | ID: mdl-32401083

RESUMO

Aims This study aimed to analyse trends in mental health presentations to the Emergency Department (ED), which anecdotally had increased over the past decade. Methods The ED's electronic 'Symphony' system was used to identify the annual number of presentations categorised as having a mental health complaint from 2006-2017. A detailed analysis was performed on presentations over a one-year period. Results The number of presentations increased from 69 in 2006 to a peak of 432 in 2016 (526% increase). The overall admission rate was 33.3%(n=99), while 52.5%(n=156) of presentations occurred outside of standard working hours. Similar increases were documented by other ED's worldwide, and the WHO estimate that neuropsychiatric disorders will become one of the top five causes of morbidity, mortality and disability among children by 2020. Conclusion With the number of mental health presentations dramatically increasing, carefully designed and integrated strategies are required to pro-actively tackle this growing epidemic.


Assuntos
Plantão Médico/estatística & dados numéricos , Serviço Hospitalar de Emergência/estatística & dados numéricos , Transtornos do Neurodesenvolvimento/epidemiologia , Neuropsiquiatria/estatística & dados numéricos , Medicina de Emergência Pediátrica/estatística & dados numéricos , Adolescente , Criança , Estudos de Coortes , Feminino , Humanos , Irlanda/epidemiologia , Masculino , Morbidade , Transtornos do Neurodesenvolvimento/mortalidade , Prevalência , Fatores de Tempo , Adulto Jovem
2.
Ir Med J ; 107(2): 53-5, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24654488

RESUMO

AN is a serious mental illness best treated in the community. Those with critically low weight require hospitalisation. There is little published research on AN in Ireland. The aim of this audit was to evaluate the Irish experience. The mean age on admission was 13.5 yrs which is 6 mo earlier than 2002 figures. Boys represented 6/20 (30%) of admissions. On admission girls were more underweight than boys (0.4th centile V 9th centile for BMI). This was despite girls presenting to hospital sooner than boys post onset of symptoms. Aside from low weight, over-exercising and food restricting were the most common presenting features. Inpatient weight restoration is successful with a mean weekly weight gain of 930g which is within the recommended range of 500-1000g/wk. Mean hospital stay was 38 days.


Assuntos
Anorexia Nervosa/epidemiologia , Hospitais Pediátricos/estatística & dados numéricos , Pacientes Internados/estatística & dados numéricos , Adolescente , Peso Corporal , Feminino , Seguimentos , Humanos , Irlanda/epidemiologia , Tempo de Internação/tendências , Masculino , Prognóstico , Estudos Retrospectivos
3.
J Clin Ultrasound ; 39(3): 122-7, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21387325

RESUMO

OBJECTIVES: To determine the best predictors of the presence of retained products of conception (RPOC) on grayscale and color Doppler transvaginal sonographic examination. METHODS: This was a retrospective study of 91 consecutive patients who underwent transvaginal sonography (TVS) with color Doppler to evaluate for the presence of RPOC. The images of TVS studies were reviewed by two radiologists in consensus blinded to the final outcome. Data on a number of variables including endometrial measurable mass and focal increased color vascularity were collected as predictors of RPOC. The patients' ages ranged from 17 to 48 years (mean, 31.8 ± 6.8) and gestational age from 5 to 24 weeks (mean, 9.2 ± 3.8). Thirty-six were confirmed as RPOC by dilatation and curettage (D&C) and pathology. Fifty-five were considered negative, 9 based on D&C results and 46 on clinical grounds. RESULTS: Sensitivity, specificity, negative- and positive-predictive and accuracy values were 81% (CI: 68%-94%), 71% (CI: 59%-83%), 85% (CI: 74%-95%), 64% (CI: 50%-78%), and 75% (CI: 66%-84%) to detect RPOC when a mass was present. The corresponding numbers for the presence of focal color vascularity were 94% (CI: 87%-100%) (p = 0.07), 67% (CI: 55%-80%) (p > 0.05), 95% (CI: 88%-100%) (p = 0.1), 65% (CI: 52%-78%) (p > 0.05), and 78% (CI: 70%-87%) (p > 0.05). Of the patients with confirmed RPOC on pathology, five had focal increased vascularity and no massand none had a mass without focal increased vascularity. CONCLUSION: An area of focal increased vascularity with or without a mass is the best predictor of the presence of RPOC.


Assuntos
Aborto Incompleto/diagnóstico por imagem , Ultrassonografia Doppler em Cores , Aborto Incompleto/patologia , Adolescente , Adulto , Dilatação e Curetagem , Endométrio/diagnóstico por imagem , Endométrio/patologia , Feminino , Humanos , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Gravidez , Estudos Retrospectivos , Sensibilidade e Especificidade , Adulto Jovem
4.
Science ; 223(4634): 400-3, 1984 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-6362007

RESUMO

Normal red cells deform markedly as they pass through the spleen and the peripheral capillaries. In these studies, the effects of Plasmodium falciparum infection and maturation on the deformability of parasitized red cells exposed to fluid shear stress in vitro were examined by means of a rheoscope. Red cells containing the early (ring) erythrocytic stage of the parasite have impaired deformability at physiologic shear stresses, and recover their normal shape more slowly. Red cells containing more mature parasites (trophozoites or schizonts) exhibit no deformation under the same conditions. These results provide a mechanism to explain the ability of the spleen to remove parasitized red cells from the circulation of both immune and nonimmune hosts.


Assuntos
Eritrócitos/parasitologia , Malária/sangue , Plasmodium falciparum/fisiologia , Animais , Viscosidade Sanguínea , Elasticidade , Membrana Eritrocítica/fisiologia , Eritrócitos/fisiologia , Humanos , Malária/parasitologia , Malária/fisiopatologia , Reologia , Baço/fisiopatologia , Propriedades de Superfície
5.
J Comp Neurol ; 427(1): 139-49, 2000 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-11042596

RESUMO

Manipulation of cortical serotonin (5-HT) levels in perinatal rodents produces significant alterations in the development of the layer IV cortical representation of the mystacial vibrissae. Monoamine oxidase A (MAO(A)) knockout mice have highly elevated cortical 5-HT and completely lack barrels in somatosensory cortex (S-I). The present study was undertaken to determine whether the effects on thalamocortical development seen in MAO(A) knockout mice can be replicated in perinatal rats treated with an MAO(A) inhibitor and, second, to determine whether these effects persist with continued treatment or after discontinuation of the drug. Littermates were injected with either clorgyline (5 mg/kg) or sterile saline five times daily. Clorgyline administration from birth to postnatal day (P) 6, 8, or 10 produced increases of 1,589.4 +/- 53.3%, 1660.2 +/- 43.1% and 1,700.5 +/- 84.5 %, respectively, in cortical 5-HT as compared with controls. Serotonin immunocytochemistry, 1,1;-dioctadecyl-3,3,3", 3;-tetramethylindocarbocyanine perchlorate (DiI) labeling of thalamocortical afferents and Nissl and cytochrome oxidase staining of layer IV cellular aggregates demonstrated that clorgyline treatment from P0 to P6 produced a complete absence of any segmentation of vibrissae-related patches in S-I. However, continued treatment until P8 or P10 did not prevent the appearance of these patches. Animals treated with clorgyline from birth to P6 and killed on P8 or P10 had increases of 546.8 +/- 33.2% and 268.8 +/- 6.3% in cortical 5-HT and they had qualitatively normal vibrissae-related patterns in S-I. These results indicate that clorgyline treatment produces a transient disruption of vibrissae-related patterns, despite the continued presence of elevated cortical 5-HT.


Assuntos
Animais Recém-Nascidos/crescimento & desenvolvimento , Padronização Corporal/efeitos dos fármacos , Clorgilina/farmacologia , Ratos Sprague-Dawley/crescimento & desenvolvimento , Serotonina/metabolismo , Córtex Somatossensorial/crescimento & desenvolvimento , Vibrissas/crescimento & desenvolvimento , Fatores Etários , Animais , Animais Recém-Nascidos/anatomia & histologia , Animais Recém-Nascidos/metabolismo , Padronização Corporal/fisiologia , Esquema de Medicação , Feminino , Masculino , Mecanorreceptores/citologia , Mecanorreceptores/efeitos dos fármacos , Mecanorreceptores/crescimento & desenvolvimento , Mecanorreceptores/metabolismo , Vias Neurais/citologia , Vias Neurais/efeitos dos fármacos , Vias Neurais/crescimento & desenvolvimento , Vias Neurais/metabolismo , Plasticidade Neuronal/efeitos dos fármacos , Plasticidade Neuronal/fisiologia , Neurônios/citologia , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Ratos , Ratos Sprague-Dawley/anatomia & histologia , Ratos Sprague-Dawley/metabolismo , Córtex Somatossensorial/citologia , Córtex Somatossensorial/efeitos dos fármacos , Córtex Somatossensorial/metabolismo , Tálamo/citologia , Tálamo/efeitos dos fármacos , Tálamo/crescimento & desenvolvimento , Tálamo/metabolismo , Vibrissas/citologia , Vibrissas/efeitos dos fármacos , Vibrissas/inervação
6.
Artigo em Inglês | MEDLINE | ID: mdl-1992102

RESUMO

In a prospective, noncomparative study, seven patients with mild Pneumocystis carinii pneumonia, characterized by room air arterial PO2 greater than 60 mm Hg at the time of presentation, were treated with dapsone alone at a dose of 200 mg daily. Two of the seven patients required mechanical ventilation for respiratory failure on day 5 of dapsone therapy; both died. Four patients experienced major side effects during dapsone therapy. None of the seven patients successfully completed a full course of therapy with dapsone. We conclude that high-dose, single-agent dapsone is not suitable for further study as therapy for Pneumocystis carinii pneumonia.


Assuntos
Dapsona/uso terapêutico , Pneumonia por Pneumocystis/tratamento farmacológico , Síndrome da Imunodeficiência Adquirida/complicações , Adulto , Dapsona/administração & dosagem , Dapsona/efeitos adversos , Humanos , Masculino , Pneumonia por Pneumocystis/complicações , Estudos Prospectivos , Distribuição Aleatória
7.
Invest Ophthalmol Vis Sci ; 27(2): 222-5, 1986 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-3943945

RESUMO

The flash visually evoked cortical potential (VECP) was recorded in 18 human albinos. In some individuals P2 (latency 100-120 msec) formed the major component while in others P1 (latency 60-80 msec) was the largest component and dominated the response. The relative amplitude of P1 compared to P2 was calculated, and the results compared to the levels of monocular Snellen Visual Acuity measured. A relationship was found such that the greater the amplitude of P1 compared to P2, the lower the level of acuity. (Group 1: rs = -0.509, P less than 0.05. Group 2: rs = -0.536, P less than 0.05).


Assuntos
Albinismo/fisiopatologia , Potenciais Evocados Visuais , Acuidade Visual , Adolescente , Adulto , Albinismo/diagnóstico , Criança , Pré-Escolar , Humanos , Estimulação Luminosa , Retina/fisiopatologia
8.
Invest Ophthalmol Vis Sci ; 30(12): 2521-7, 1989 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-2592164

RESUMO

Presaccadic spike potentials were recorded from electrodes placed at the inner canthus and below the eye in ten normal subjects. The responses to twenty abducting and twenty adducting saccades were back-averaged from the beginning of the eye movement, and separate waveforms were obtained for saccades of 20 degrees, 10 degrees, 7.5 degrees, 5.0 degrees, and 2.5 degrees. The spike onset and peak latencies relative to the beginning of the eye movement and the onset-peak amplitudes were measured. Throughout the range of saccade sizes, the onset and peak occurred earlier with adduction than with abduction, but there was no consistent change in the latency values with saccade size. The amplitude, however, showed an increase with saccade size up to movements of 10 degrees, although statistical analysis showed that these amplitude changes were not consistently significant. Comparison of the 20 degrees saccades to the 10 degrees saccades and the 10 degrees saccades to the 7.5 degrees saccades revealed no statistically significant differences in amplitudes. The difference between the 7.5 degrees and the 5 degrees saccades, however, was statistically significant (P less than 0.05) but only at the inner electrode with abduction; comparison of the 5 degrees and 2.5 degrees results showed a significant difference (P less than 0.01) at the inner electrode with both abduction and adduction. Comparison of the 7.5 degrees and the 2.5 degrees showed a significant difference (P less than 0.01) at both electrode sites with abduction and adduction. These findings are discussed with respect to the previously suggested origin of the spike potential and the choice of the recording electrode site.


Assuntos
Movimentos Oculares/fisiologia , Movimentos Sacádicos/fisiologia , Potenciais de Ação , Adulto , Interpretação Estatística de Dados , Eletrodos , Humanos
9.
Invest Ophthalmol Vis Sci ; 29(7): 1165-7, 1988 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-3417405

RESUMO

Flash visually evoked cortical potentials have been recorded in three groups of age- and sex-matched subjects; one comprised of subjects with dissociated vertical deviation, one comprised of subjects with oculocutaneous albinism and one group of controls. The latency of the major positive (P2) component did not show statistically significant contralateral lateralization on monocular stimulation in either the dissociated vertical deviation group or the control group. Contralateral lateralization was found in the albino group at a statistically significant level (P less than 0.01). It is concluded that subjects with dissociated vertical deviation do not possess the typical albino optic pathway misrouting that has been reported.


Assuntos
Albinismo/fisiopatologia , Esotropia/fisiopatologia , Exotropia/fisiopatologia , Estrabismo/fisiopatologia , Vias Visuais/fisiopatologia , Adolescente , Córtex Cerebral/fisiopatologia , Criança , Potenciais Evocados Visuais , Humanos , Estimulação Luminosa , Tempo de Reação , Valores de Referência
10.
Invest Ophthalmol Vis Sci ; 25(12): 1448-50, 1984 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-6511228

RESUMO

Investigations were undertaken to determine which particular components of the flash visual-evoked cortical potential (VECP) lateralize on monocular stimulation in human albinos. Our results demonstrate that only the major positive component shows clear lateralization. Statistical analysis revealed that the latency lateralization was significant (P less than 0.001) while the amplitude lateralization was not.


Assuntos
Albinismo/fisiopatologia , Córtex Cerebral/fisiopatologia , Potenciais Evocados Visuais , Adolescente , Adulto , Criança , Pré-Escolar , Humanos , Estimulação Luminosa
11.
Behav Neurosci ; 108(2): 418-23, 1994 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-8037885

RESUMO

Previous results show that endogenous opioid systems mediate affective responses in neonatal rats. Opioids modulate isolation-induced ultrasonic vocalizations and analgesia. This study further examines the behavioral effects of kappa-receptor-system stimulation on 10-day-old rats. With the agonist U50,488, response to isolation in terms of vocalizations, activity levels, and pain sensitivity was tested. In contrast to morphine's effects (primarily a mu-agonist), the kappa-agonist U50,488 produced increased vocalizing and hyperactivity, although both opioid agonists caused analgesia. Isolation adds to the U50,488-mediated increase in the latency for paw withdrawal from heat. This study suggests that the kappa system provokes calling and activity as opposed to the quieting effects of mu-agonists found in previous studies. These differential effects may be due in part to the interaction of the opioid and dopamine systems.


Assuntos
Analgésicos/farmacologia , Comportamento Animal/efeitos dos fármacos , Encéfalo/efeitos dos fármacos , Naltrexona/farmacologia , Pirrolidinas/farmacologia , Receptores Opioides kappa/efeitos dos fármacos , (trans)-Isômero de 3,4-dicloro-N-metil-N-(2-(1-pirrolidinil)-ciclo-hexil)-benzenoacetamida , Animais , Animais Recém-Nascidos , Nível de Alerta/efeitos dos fármacos , Regulação da Temperatura Corporal/efeitos dos fármacos , Relação Dose-Resposta a Droga , Feminino , Masculino , Atividade Motora/efeitos dos fármacos , Limiar da Dor/efeitos dos fármacos , Gravidez , Ratos , Ratos Sprague-Dawley , Isolamento Social , Vocalização Animal/efeitos dos fármacos
12.
Behav Neurosci ; 106(2): 374-9, 1992 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-1590955

RESUMO

The effects of cocaine administration on isolation-induced vocalizations and activity levels in 10-day-old rat pups were examined. Day 10 pups given cocaine (1.25, 2.5, 5, 10, & 20 mg/kg ip) vocalized significantly less than their caffeine- (10 mg/kg) and saline-administered siblings during a 5-min isolation period. Cocaine- and caffeine-administered pups also demonstrated a significant increase in overall activity compared with controls. In addition, intraperitoneal administration of the dopamine antagonist haloperidol (0.5 & 1.0 mg/kg) before 1.25 and 2.5 mg/kg cocaine produced a significant elevation in vocalizations compared with saline pretreatment, which indicates a blocking of cocaine's effect on calling behavior. These results suggest that the endogenous dopamine system involved with reinforcement and reward may quell the stress of isolation in the infant rat.


Assuntos
Nível de Alerta/efeitos dos fármacos , Cocaína/farmacologia , Meio Social , Isolamento Social , Vocalização Animal/efeitos dos fármacos , Animais , Animais Recém-Nascidos , Encéfalo/efeitos dos fármacos , Relação Dose-Resposta a Droga , Feminino , Ratos , Ratos Endogâmicos , Receptores Dopaminérgicos/efeitos dos fármacos
13.
Brain Res ; 710(1-2): 11-20, 1996 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-8963648

RESUMO

We have previously demonstrated alterations in serotonin metabolism within descending pathways following infusion of brain-derived neurotrophic factor (BDNF) into the midbrain, near the periaqueductal gray and dorsal and median raphe nuclei. The aim of the present study was to extend these studies to include a comprehensive regional examination of monoamine (serotonin, dopamine and norepinephrine) and metabolite levels in discrete areas of the intact, adult rat forebrain following direct intraparenchymal midbrain BDNF infusion. We have compared neurochemical changes following midbrain infusion of BDNF to those obtained following intracerebroventricular (i.c.v.) infusion. Significant increases in levels of 5-HIAA and/or the 5-HIAA/5-HT ratio were found in all areas examined including the hippocampus, cortex, striatum, n. accumbens, substantia nigra and hypothalamus following both midbrain and i.c.v. infusion. Changes in dopaminergic activity were also observed, but displayed more regional specificity, i.e. changes were found primarily within the striatum and cortex. The two infusion sites produced similar patterns of neurochemical effects although the magnitude of the changes did vary in some areas. These results suggest that BDNF increased synthesis and/or turnover of serotonin, and to a lesser extent dopamine, in the mature rat forebrain. Furthermore, these data point to possible functional roles for BDNF in neuropsychiatric and neurodegenerative conditions which involve a dysregulation of these monoamine systems.


Assuntos
Monoaminas Biogênicas/metabolismo , Fator Neurotrófico Derivado do Encéfalo/farmacologia , Encéfalo/metabolismo , Animais , Peso Corporal/efeitos dos fármacos , Dopamina/fisiologia , Feminino , Injeções , Injeções Intraventriculares , Masculino , Fatores de Crescimento Neural/farmacologia , Norepinefrina/fisiologia , Ratos , Ratos Sprague-Dawley , Serotonina/fisiologia
14.
Brain Res ; 709(2): 275-84, 1996 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-8833764

RESUMO

Rat models of Parkinson's disease typically employ a rapid nigral injection of 6-hydroxydopamine (6-OHDA) to produce a near-complete loss of nigrostriatal dopamine neurons, and thus, model end stage disease. The present report describes the use of a continuous, low dose infusion of 6-OHDA into the striatum which produces a terminal axotomy of nigrostriatal dopamine neurons and protracted behavioral response. A solution of 6-OHDA in 0.4% ascorbate, delivered at 37 degrees C from osmotic minipumps, was stable for 8 days as determined by its retained toxicity to a dopaminergic neuroblastoma cell line. The continuous infusion of 0.2 mu g 6-OHDA per h did not affect the striatal uptake of [3H]%GABA, [3H]choline, or [3H]glutamate but reduced [3H]dopamine uptake by 55% within 1.5 days after the start of the infusion. The striatal infusion of 6-OHDA produced a dose-dependent reduction of striatal dopamine and DOPAC levels but did not alter HVA, 5-HT, or 5-HIAA. An increase in amphetamine-induced ipsiversive rotations occurred within 1.5 days after the acute striatal injection of 20 mu g or 30 mu g of 6-OHDA but required 4 days to develop with the continuous 6-OHDA infusion. The topography of the lesion mapped by [3H]mazindol binding showed that, beginning by 1.5 days, a diffuse depletion of terminals encompassed much of the striatum in the 30 mu g acute injection group, whereas in the continuously infused rats, the lesion was apparent only by 4 days and was restricted to a smaller and more completely lesioned area. Unlike acutely lesioned animals, continuously infused rats revealed no obvious loss of dopamine neurons in the pars compacta by 5 weeks after 6-OHDA. The continuous striatal infusion of 6-OHDA can produce a topographically limited terminal axotomy of dopamine neurons and a protracted behavioral impairment.


Assuntos
Axônios/efeitos dos fármacos , Comportamento Animal/efeitos dos fármacos , Corpo Estriado/fisiologia , Oxidopamina/administração & dosagem , Animais , Autorradiografia , Ligação Competitiva , Monoaminas Biogênicas/metabolismo , Linhagem Celular/efeitos dos fármacos , Colina/metabolismo , Corpo Estriado/metabolismo , Denervação , Ácido Glutâmico/metabolismo , Imuno-Histoquímica , Masculino , Mazindol/metabolismo , Oxidopamina/farmacologia , Ratos , Ratos Sprague-Dawley , Comportamento Estereotipado/fisiologia , Tirosina 3-Mono-Oxigenase/metabolismo , Ácido gama-Aminobutírico/metabolismo
15.
Brain Res Dev Brain Res ; 129(1): 95-106, 2001 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-11454416

RESUMO

Elevating cortical serotonin (5-HT) in rats from postnatal day (P-) 0 to P-6 by administering the monoamine oxidase (MAO(A)) inhibitor, clorgyline, produces a dose-dependent spectrum of effects on rat somatosensory organization, ranging from enlarged with indistinct septa to a complete lack of vibrissae-related patterns. However, if clorgyline treatment is stopped on P-6, a qualitatively and quantitatively normal vibrissae-related pattern of thalamocortical afferents appears in somatosensory cortex (S-I) on P-10. We employed high performance liquid chromatography (HPLC), infraorbital nerve (ION) transection, N-methyl-D-aspartate (NMDA) receptor blockade, 1,1'-dioctadecyl-3,3,3"3'-tetramethylindocarbocyanine perchlorate (DiI) labeling of thalamic afferents, and CO histochemistry to determine whether peripheral nerve input and/or cortical NMDA receptor activity were required for the recovery of vibrissae-related patterns in clorgyline-treated animals. Clorgyline administration from P-0 to P-6 produced a 1589.4+/-53.3% increase in cortical 5-HT over control animals on P-6 and a 268.8+/-6.3% elevation over controls at P-10. Postnatal day 6 pups had significantly altered vibrissae-related patterns in S-I following 6 days of clorgyline treatment but by P-10, the characteristic vibrissae-related patterns were restored. Neither transection of the ION nor application of the NMDA antagonist, DL-2-amino-5-phosphonovaleric acid (APV), to the cortices of P-6 pups that were treated with clorgyline from birth had any significant effect on the recovery of the vibrissae-related patterns by P-10. These results indicate that neither peripheral nerve input nor cortical NMDA receptor activity are necessary for the restoration of cortical vibrissae-related patterns in rats that have sustained transient elevations of 5-HT.


Assuntos
Nervo Maxilar/citologia , Nervo Maxilar/fisiologia , Receptores de N-Metil-D-Aspartato/metabolismo , Córtex Somatossensorial/citologia , Córtex Somatossensorial/crescimento & desenvolvimento , 2-Amino-5-fosfonovalerato/farmacologia , Animais , Animais Recém-Nascidos , Autorradiografia , Tronco Encefálico/citologia , Tronco Encefálico/efeitos dos fármacos , Tronco Encefálico/crescimento & desenvolvimento , Carbocianinas , Cromatografia Líquida de Alta Pressão , Clorgilina/farmacologia , Denervação , Maleato de Dizocilpina/farmacologia , Antagonistas de Aminoácidos Excitatórios/farmacologia , Feminino , Corantes Fluorescentes , Radioisótopos do Iodo , Masculino , Inibidores da Monoaminoxidase/farmacologia , Neurônios Aferentes/fisiologia , Ratos , Ratos Sprague-Dawley , Receptores de N-Metil-D-Aspartato/antagonistas & inibidores , Serotonina/metabolismo , Córtex Somatossensorial/efeitos dos fármacos , Tálamo/citologia , Tálamo/efeitos dos fármacos , Tálamo/crescimento & desenvolvimento , Vibrissas/inervação
16.
Brain Res Dev Brain Res ; 120(1): 91-3, 2000 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-10727735

RESUMO

Recent studies have suggested that 5-HT may modulate thalamocortical development in somatosensory cortex (S-I) of rats and mice, and that the 5-HT(1B) receptor may play a critical role in this process. Analysis of CO-stained sections through lamina IV of S-I in perinatal and adult 5-HT(1B) knockout mice revealed a normal vibrissae-related pattern, indicating that activation of the 5-HT(1B) receptor is not necessary for the normal development of the vibrissae representation in S-I.


Assuntos
Receptores de Serotonina/genética , Córtex Somatossensorial/química , Córtex Somatossensorial/crescimento & desenvolvimento , Vibrissas/inervação , Animais , Química Encefálica/genética , Complexo IV da Cadeia de Transporte de Elétrons/análise , Regulação da Expressão Gênica no Desenvolvimento , Camundongos , Camundongos Knockout , Camundongos Transgênicos , Receptor 5-HT1B de Serotonina , Córtex Somatossensorial/enzimologia
17.
ISA Trans ; 25(4): 1-5, 1986.
Artigo em Inglês | MEDLINE | ID: mdl-3793426

RESUMO

Adequate erythrocyte deformability is crucial to microvascular function. In sickle cell anemia, a significant fraction of the circulating red cells lose deformability and assume highly abnormal shapes when exposed to low plasma oxygen tension (PO2). The loss of deformability is believed to induce blockage of flow in capillaries with consequent painful crisis or organ infarcts. The deformability of sickle erythrocytes at graded levels of PO2 were investigated in the rheoscope, a viscometric device consisting of transparent counter-rotating cone and plate. Quantitative indices of deformability obtained from still photographs and videotape recordings of cells subjected to shear flow were: fraction of all suspended cells capable of deformation, steady-state elongation, and time course of transient shape recovery following abrupt flow cessation. Suspensions of unfractionated cells were first equilibrated against gas mixtures (O2, N2, CO2) with PO2 = 160, 40 or 20 mm Hg at room temperature and then sheared under the same atmosphere. Results obtained with blood samples from ten pediatric patients being treated at St. Louis Children's Hospital show strong donor-to-donor variations and significant impairment of deformability in the unsickled members of the cell populations relative to normal controls.


Assuntos
Anemia Falciforme/sangue , Deformação Eritrocítica , Anemia Falciforme/diagnóstico , Animais , Eritrócitos/citologia , Humanos , Oxigênio , Pressão Parcial , Fotografação , Ovinos
18.
Phys Med Biol ; 57(12): 3727-39, 2012 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-22617805

RESUMO

Kilovoltage cone-beam CT (kV CBCT) can be acquired during the delivery of volumetric modulated arc therapy (VMAT), in order to obtain an image of the patient during treatment. However, the quality of such CBCTs is degraded by megavoltage (MV) scatter from the treatment beam onto the imaging panel. The objective of this paper is to introduce a novel MV scatter correction method for simultaneous CBCT during VMAT, and to investigate its effectiveness when compared to other techniques. The correction requires the acquisition of a separate set of images taken during VMAT delivery, while the kV beam is off. These images--which contain only the MV scatter contribution on the imaging panel--are then used to correct the corresponding kV/MV projections. To test this method, CBCTs were taken of an image quality phantom during VMAT delivery and measurements of contrast to noise ratio were made. Additionally, the correction was applied to the datasets of three VMAT prostate patients, who also received simultaneous CBCTs. The clinical image quality was assessed using a validated scoring system, comparing standard CBCTs to the uncorrected simultaneous CBCTs and a variety of correction methods. Results show that the correction is able to recover some of the low and high-contrast signal to noise ratio lost due to MV scatter. From the patient study, the corrected CBCT scored significantly higher than the uncorrected images in terms of the ability to identify the boundary between the prostate and surrounding soft tissue. In summary, a simple MV scatter correction method has been developed and, using both phantom and patient data, is shown to improve the image quality of simultaneous CBCTs taken during VMAT delivery.


Assuntos
Tomografia Computadorizada de Feixe Cônico/métodos , Processamento de Imagem Assistida por Computador/métodos , Radioterapia Assistida por Computador/métodos , Espalhamento de Radiação , Humanos , Masculino , Imagens de Fantasmas , Neoplasias da Próstata/diagnóstico por imagem , Neoplasias da Próstata/radioterapia
19.
Phys Med Biol ; 56(13): 4119-33, 2011 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-21693790

RESUMO

The delivery of volumetric modulated arc therapy (VMAT) requires the simultaneous movement of the linear accelerator gantry, multi-leaf collimators and jaws while the dose rate is varied. In this study, a VMAT delivery emulator was developed to accurately predict the characteristics of a given treatment plan, incorporating realistic parameters for gantry inertia and the variation in leaf speed with respect to gravity. The emulator was used to assess the impact of dynamic machine parameters on the delivery efficiency, using a set of prostate and head and neck VMAT plans. Initially, assuming a VMAT system with fixed dose rate bins, the allowable leaf and jaw speeds were increased and a significant improvement in treatment time and average dose rate was observed. The software was then adapted to simulate a VMAT system with continuously varying dose rate, and the increase in delivery efficiency was quantified, along with the impact of an increased leaf and jaw speed. Finally, a set of optimal dynamic machine parameters was derived assuming an idealized scenario in which the treatment is delivered in a single arc at constant maximum gantry speed.


Assuntos
Radioterapia Assistida por Computador/métodos , Humanos , Dosagem Radioterapêutica
20.
Phys Med Biol ; 55(14): N395-404, 2010 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-20601771

RESUMO

Volumetric modulated arc therapy (VMAT) is a rotational delivery technique which offers the potential of improved dose distributions and shorter treatment times when compared to fixed-beam intensity-modulated radiation therapy (IMRT). This note describes the use of an existing treatment planning system (Philips Pinnacle(3) v.8.0), supplemented by in-house software, to produce a single-arc VMAT prostate plan. While a number of planning systems for the Elekta VMAT platform are commercially available, the use of an in-house solution has allowed more detailed investigations of VMAT planning, as well as greater control over the optimization process. The solution presented here begins with a static step-and-shoot IMRT approach to provide initial segment shapes, which are then modified and sequenced into 60 equally spaced control points in a 360 degrees arc. Dose-volume histogram comparisons demonstrate that this VMAT planning method offers multiple dose level target coverage comparable to that from a standard IMRT approach. The VMAT plans also show superior sparing of critical structures such as the rectum and bladder. Delivery times are reduced with the VMAT method, and the results of dosimetric verification, resilience and repeatability tests indicate that the solution is robust.


Assuntos
Neoplasias da Próstata/radioterapia , Planejamento da Radioterapia Assistida por Computador/métodos , Radioterapia/métodos , Humanos , Masculino , Próstata/efeitos da radiação , Radioterapia/instrumentação , Dosagem Radioterapêutica , Planejamento da Radioterapia Assistida por Computador/instrumentação , Radioterapia de Intensidade Modulada/métodos , Reto/efeitos da radiação , Reprodutibilidade dos Testes , Software , Fatores de Tempo , Bexiga Urinária/efeitos da radiação
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