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1.
Prog Brain Res ; 228: 221-39, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27590971

RESUMO

Brain-computer interfaces (BCIs) are often based on the control of sensorimotor processes, yet sensorimotor processes are impaired in patients suffering from amyotrophic lateral sclerosis (ALS). We devised a new paradigm that targets higher-level cognitive processes to transmit information from the user to the BCI. We instructed five ALS patients and twelve healthy subjects to either activate self-referential memories or to focus on a process without mnemonic content while recording a high-density electroencephalogram (EEG). Both tasks are designed to modulate activity in the default mode network (DMN) without involving sensorimotor pathways. We find that the two tasks can be distinguished after only one experimental session from the average of the combined bandpower modulations in the theta- (4-7Hz) and alpha-range (8-13Hz), with an average accuracy of 62.5% and 60.8% for healthy subjects and ALS patients, respectively. The spatial weights of the decoding algorithm show a preference for the parietal area, consistent with modulation of neural activity in primary nodes of the DMN.


Assuntos
Esclerose Lateral Amiotrófica/reabilitação , Interfaces Cérebro-Computador , Cognição/fisiologia , Neurorretroalimentação/métodos , Lobo Parietal/fisiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Algoritmos , Ritmo alfa/fisiologia , Mapeamento Encefálico , Eletroencefalografia , Eletromiografia , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Neurorretroalimentação/instrumentação , Análise de Componente Principal , Ritmo Teta/fisiologia , Interface Usuário-Computador , Adulto Jovem
2.
Heart Asia ; 6(1): 109-15, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-27326182

RESUMO

BACKGROUND: Aortic pulse wave velocity (APWV), a marker of arterial stiffness, was found to be a good predictor for the presence of incipient vascular disease and cardiovascular events in observational studies. APWV measured by echo Doppler is a simple and readily available method comparable with other costlier and complex modalities of APWV measurement like MRI, Complior method or applanation tonometry. AIMS AND OBJECTIVES: No previous studies have demonstrated a relationship between APWV findings and the complexity of coronary artery disease (CAD). Our aim was to examine the relationship between APWV findings and the severity of SYNTAX scores (SX scores). METHODS: 500 patients who had undergone APWV measurements and elective coronary angiography from September 2012 to June 2013 were taken. Pulsed Doppler ultrasound (6.6 MHZ) probe with ECG synchronisation was used to calculate APWV. SYNTAX scoring was performed by observers who were blinded to APWV values. RESULTS: A significant, nearly linear correlation between APWV and advancing CAD (p<0.0001) was observed. Patients with dual-vessel and triple-vessel disease had significantly higher APWV than patients without CAD. It was also found that mean APWV values were significantly more in patients with high or intermediate SX scores than in patients with low SX scores. The Fischer's linear discriminant analysis showed a cut-off value of APWV for predicting the possibility of having CAD to be >11.5 m/s. CONCLUSIONS: APWV has predictive value for the SX score. A positive relation exists between aortic stiffening and coronary atherosclerosis and APWV measured by 2D Doppler is a good predictor of advancing CAD.

3.
J Nanosci Nanotechnol ; 9(9): 5461-6, 2009 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-19928244

RESUMO

Formation of nanocrystalline TiN at low temperatures was demonstrated by combining Pulsed Laser Deposition (PLD) and ion implantation techniques. The Ti films of nominal thickness approximatly 250 nm were deposited at a substrate temperature of 200 degrees C by ablating a high pure titanium target in UHV conditions using a nanosecond pulsed Nd:YAG laser operating at 1064 nm. These films were implanted with 100 keV N+ ions with fluence ranging from 1.0 x 10(16) ions/cm2 to 1.0 x 10(17) ions/cm2 The structural, compositional and morphological evolutions were tracked using Transmission Electron Microscopy (TEM), Secondary Ion Mass Spectrometry (SIMS) and Atomic Force Microscopy (AFM), respectively. TEM analysis revealed that the as-deposited titanium film is an fcc phase. With increasing ion fluence, its structure becomes amorphous phase before precipitation of nanocrystalline fcc TIN phase. Compositional depth profiles obtained from SIMS have shown the extent of nitrogen concentration gradient in the implantation zone. Both as-deposited and ion implanted films showed much higher hardness as compared to the bulk titanium. AFM studies revealed a gradual increase in surface roughness leading to surface patterning with increase in ion fluence.

4.
Indian J Pathol Microbiol ; 51(3): 379-81, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18723963

RESUMO

To evaluate the diagnostic efficacy of various screening tests in detecting asymptomatic bacteriuria among pregnant women. Clean catch midstream urine specimens were collected from 630 consecutive pregnant women and processed. Forty-four (7.4%) of the urine samples were culture positive, with Escherichia coli as the predominant organism isolated (57.4%). The results of the four screening tests, viz., Gram's staining of uncentrifuged urine, pus cell count, nitrite test and leukocyte esterase (LE) test, were compared against urine culture. Gram's stain of the uncentrifuged urine was found to be the single most useful test with a sensitivity and negative predictive value (NPV) of 85.1% and 98.8%, respectively. Pus cell count was the least sensitive. Neither the nitrite test nor the LE test alone was sensitive enough with 74.4% and 61.7%, respectively. However, when either or both tests positive were considered, it increased the sensitivity and NPV comparable with Gram's staining results, with 82.9% and 98.8%, respectively. With the potential to be used as an office diagnostic procedure, the combined nitrite and LE dipstick test may provide an acceptable alternative.


Assuntos
Bactérias/isolamento & purificação , Bacteriúria/diagnóstico , Programas de Rastreamento/métodos , Complicações Infecciosas na Gravidez , Feminino , Humanos , Valor Preditivo dos Testes , Gravidez , Gestantes , Sensibilidade e Especificidade
5.
BJOG ; 111(6): 619-22, 2004 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-15198792

RESUMO

Overall, about one-third of women operated upon because of suspected ovarian cancer turn out to have benign disease. This proportion will be even higher when the tumours are small. A more accurate method of determining which are malignant would reduce the number of unnecessary referrals to the cancer centre and increase the scope for conservative management. This pilot study of ultrasound and intravenous microbubble contrast in 20 women with small ovarian tumours enabled the identification of all four malignant lesions with good inter-observer agreement. These preliminary findings suggest that intravenous contrast improves the ultrasound identification of small ovarian malignancies and may provide an accurate way of selecting women who require to be referred urgently for surgery under the auspices of a gynaecological oncologist. The remainder might be considered for laparoscopic surgery or even for observation in some cases.


Assuntos
Neoplasias Ovarianas/diagnóstico por imagem , Adulto , Idoso , Feminino , Humanos , Pessoa de Meia-Idade , Neoplasias Ovarianas/irrigação sanguínea , Fatores de Risco , Sensibilidade e Especificidade , Ultrassonografia Doppler/métodos
6.
Rofo ; 172(10): 824-9, 2000 Oct.
Artigo em Alemão | MEDLINE | ID: mdl-11111294

RESUMO

PURPOSE: To investigate if the duration of Doppler enhancement of the ultrasound contrast agent Levovist can be prolonged by continuous infusion compared to bolus injections in patients. METHODS: 12 patients with suspected renal artery stenosis were included. Each patient received 1 or 2 bolus injections of 4 g each and a "fast" infusion of 3 ml/min (average dose: 7 g) of Levovist. In 8 patients an additional "slow" infusion of 1 ml/min (average dose 4.2 g) was given. The duration of "strong" Doppler signal enhancement and the visualization of vessels were compared. RESULTS: The duration of strong enhancement was substantially prolonged by the slow infusion (bolus 6:21 min, fast infusion: 8:57 min, slow infusion: 15:12 min, p < 0.001). The dose effectiveness (duration of strong enhancement per 1 g Levovist) was markedly improved from 0:57 min (bolus) to 3:36 min (slow infusion). Visualisation of the renal arteries was more complete with the slow infusion. CONCLUSION: Levovist infusions at 1 ml/min are superior to bolus injections in the assessment of renal arteries. They prolong the enhancement, make more efficient use of a given dose of contrast material and thus allow additional clinically relevant information to be obtained at reduced cost.


Assuntos
Meios de Contraste/administração & dosagem , Polissacarídeos/administração & dosagem , Obstrução da Artéria Renal/diagnóstico por imagem , Adulto , Idoso , Feminino , Humanos , Infusões Intravenosas , Injeções Intravenosas , Masculino , Pessoa de Meia-Idade , Ultrassonografia Doppler em Cores
7.
Rofo ; 172(1): 61-7, 2000 Jan.
Artigo em Alemão | MEDLINE | ID: mdl-10719465

RESUMO

PURPOSE: The purpose of this study was systematically to investigate stimulated acoustic emission (SAE) with the microbubble contrast agent Levovist (Schering AG, Berlin) in vivo with regards to reproducibility, distribution in various organs over time, dependence on technical factors, and influence on the delineation of focal liver lesions. PATIENTS AND METHODS: 2 intravenous injections of 1 g of Levovist were given to 2 dogs and 1-6 injections of 2.5 g Levovist to 5 healthy volunteers and 37 patients. The liver, spleen, large abdominal vessels, and kidney were intermittently scanned for up to 30 min. Studies were evaluated for the presence of SAE signals by 2 observers. In 20 patients with focal liver lesions (15 with metastases, 4 haemangiomata, 1 hepatocellular carcinoma, and 1 cyst) the influence on lesion visualization was also assessed. RESULTS: SAE effects, lasting up to 30 minutes, were seen in all subjects in the liver and spleen. Vascular and renal SAE signals were noted shortly after injection, lasting up to 6 minutes. SAE was absent or markedly reduced in focal liver lesions, which were seen as colour voids. This increased the conspicuity of focal lesions, and in 5 patients additional metastases were detected that could not be delineated on B-mode alone. CONCLUSION: A liver- and spleen-specific late phase of Levovist can be consistently demonstrated using SAE and the effect increases the conspicuity of focal liver lesions.


Assuntos
Meios de Contraste , Neoplasias Hepáticas/diagnóstico por imagem , Fígado/diagnóstico por imagem , Polissacarídeos , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Carcinoma Hepatocelular/diagnóstico por imagem , Cães , Relação Dose-Resposta a Droga , Feminino , Hiperplasia Nodular Focal do Fígado/diagnóstico por imagem , Hemangioma/diagnóstico por imagem , Humanos , Neoplasias Hepáticas/secundário , Masculino , Pessoa de Meia-Idade , Valores de Referência , Ultrassonografia Doppler em Cores
9.
Lancet ; 353(9164): 1579-83, 1999 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-10334257

RESUMO

BACKGROUND: Hepatic cirrhosis is accompanied by several haemodynamic changes including arterialisation of the liver, intrahepatic shunts, pulmonary arteriovenous shunts, and a hyperdynamic circulatory state. We postulated that the hepatic first pass of a bolus of an ultrasound contrast agent injected into a peripheral vein is accelerated in patients with cirrhosis. We investigated this first pass in patients with diffuse liver disease and in normal controls to assess whether it provides useful differential diagnostic information. METHODS: We enrolled 15 patients with biopsy-proven cirrhosis, 12 patients with biopsy-proven non-cirrhotic diffuse liver disease, and 11 normal controls. We carried out continuous spectral doppler ultrasonography of a hepatic vein from 20 s before to 3 min after a peripheral intravenous bolus injection of 2.5 g Levovist. The intensity of the doppler signal was measured and used to plot time-intensity curves. FINDINGS: Patients with cirrhosis showed a much earlier onset of enhancement (arrival time; mean 18.3 s) and peak enhancement (mean 55.5 s) than controls (49.8 s and 97.5 s) or patients with non-cirrhotic diffuse liver disease (35.8 s and 79.7 s). All patients with cirrhosis had an arrival time of the bolus of less than 24 s, whereas the arrival time was 24 s or more in 22 of the 23 other participants. Peak enhancement was higher in patients with cirrhosis (mean 48.7 units) than in the other two groups (12.5 and 12.3 units, respectively). We found highly significant differences between the patients with cirrhosis and each of the other two groups for all variables (p<0.005), whereas we found no significant differences between non-cirrhotic patients and controls. INTERPRETATION: Our preliminary study suggests that analysis of liver transit time of a bolus of ultrasound contrast agent provides useful information about haemodynamic changes in patients with cirrhosis. Measurement of the arrival time of the bolus allows discrimination of patients with cirrhosis from controls and from patients with non-cirrhotic diffuse liver disease, and has potential as a non-invasive test for cirrhosis.


Assuntos
Meios de Contraste/farmacocinética , Técnicas de Diagnóstico do Sistema Digestório , Cirrose Hepática/diagnóstico por imagem , Cirrose Hepática/diagnóstico , Polissacarídeos , Adulto , Idoso , Diagnóstico Diferencial , Feminino , Hepatite C Crônica/diagnóstico , Hepatite C Crônica/diagnóstico por imagem , Humanos , Injeções Intravenosas , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Polissacarídeos/farmacocinética , Fatores de Tempo , Ultrassonografia
10.
Radiology ; 210(2): 409-16, 1999 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-10207423

RESUMO

PURPOSE: To see whether stimulated acoustic emission (SAE) in the liver parenchyma in the late phase of enhancement with SH U 508A increases the conspicuity of occult metastases at ultrasonography (US). MATERIALS AND METHODS: Eighteen patients with known hypo- or hypervascular hepatic metastases underwent US after SH U 508A administration, after a delay of at least 5 minutes, to ensure decay of blood pool enhancement. In 16 patients with visible metastases, conspicuity was compared on registered SAE and gray-scale scans by two blinded readers and by using computerized analysis of relative gray-scale and color Doppler conspicuity scores inside and outside the lesion. In nine patients, areas suspected of being involved but without definite gray-scale masses were imaged in the same way. Paired sections were analyzed by two blinded readers looking for parenchymal color defects without corresponding gray-scale masses; nine control images from three healthy volunteers were also included. RESULTS: Intense, transient parenchymal SAE was seen in all subjects. All metastases appeared as areas of reduced or absent signal. The conspicuity score was 80% for SAE versus 9% for gray-scale US (P < .001, Wilcoxon signed rank test). SAE-specific defects were seen in all patients but in none of the volunteers. Metastases seen on SAE but undetectable on gray-scale images were proved in three patients. CONCLUSION: SAE with SH U 508A improves the conspicuity of metastases. SAE-specific defects may reveal isoechoic or subtle metastases.


Assuntos
Meios de Contraste , Neoplasias Hepáticas/diagnóstico por imagem , Neoplasias Hepáticas/secundário , Polissacarídeos , Biópsia , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Fígado/diagnóstico por imagem , Fígado/patologia , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Fatores de Tempo , Ultrassonografia
11.
Ultrasound Med Biol ; 25(9): 1341-52, 1999 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-10626621

RESUMO

Quantitative studies were performed to investigate liver- specific uptake of the microbubble Levovist, using stimulated acoustic emission (SAE), which can detect microbubbles even when stationary or slow-moving. These comprised studies of biodistribution comparing the liver and kidney in five normal volunteers, reproducibility in 34 patients, comparison between cirrhotics and controls (n = 9 each) and maximal depth of effect at different frequencies (180 measurements in 31 patients). Stimulated acoustic emission lasted beyond 30 min, with strongly liver-specific properties in each volunteer and was highly reproducible. No difference in the amount of SAE in the superficial liver was seen between cirrhotic and normal livers, but attenuation was higher in cirrhotics. This demonstrates a frequency-dependent effect on liver SAE penetration. We conclude that the liver uptake of Levovist lasts over 30 min, is reproducible, occurs even where diffuse liver disease is present and can be used to assess tissue attenuation in a novel fashion.


Assuntos
Meios de Contraste , Cirrose Hepática/diagnóstico por imagem , Fígado/diagnóstico por imagem , Polissacarídeos , Adulto , Idoso , Feminino , Humanos , Rim/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Baço/diagnóstico por imagem , Ultrassonografia
12.
Radiology ; 209(3): 862-6, 1998 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-9844688

RESUMO

Spectral Doppler intensitometry to study transit of a bolus of an ultrasonographic (US) contrast agent in the hepatic veins was performed in seven patients suspected of having liver metastases and seven control subjects. All control subjects had a late response (rise time, > 25 seconds; time to peak intensity, > 45 seconds), whereas six of seven patients had an early response (rise time, < 25 seconds; time to peak intensity, < 45 seconds) (P < .01).


Assuntos
Meios de Contraste/farmacocinética , Neoplasias Hepáticas/diagnóstico por imagem , Neoplasias Hepáticas/secundário , Fígado/irrigação sanguínea , Flebografia , Polissacarídeos/farmacocinética , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Viabilidade , Feminino , Humanos , Circulação Hepática , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Ultrassonografia
16.
Indian J Psychiatry ; 37(1): 26-30, 1995 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21743711

RESUMO

Data on the nature and extent of major eating disorders, anorexia nervosa and bulimia is lacking in non-white, native populations of the developing world, leaving a gap in understanding the determinants of these disorders. In a study on 210 medical students examined by a two-stage survey method, 31 subjects were found to have distress relating to their eating habits and body size not amounting to criterion-based diagnosis of eating disorders. The characteristics of this eating distress syndrome are described in relation to the major eating disorders.

17.
Indian J Psychiatry ; 37(3): 139-42, 1995 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-21743735

RESUMO

This case report on the use of Maintenance Electroconvulsive Therapy (ECT-M) presents certain observations and raises some issues in the use of the method. The report offers wider indication for ECT-M, including schizophrenia and bipolar disorders and younger patients. It raises the issues that die duration of use of ECT-M can be short rather than indefinite and that in the post ECT-M period, drug maintenance using the same drugs which were ineffective pre-ECT-M can be used effectively. The report presents those observations for further systematic study. The cost benefit advantage of the method and its relevance to the need for more frequent use in developing countries is illustrated.

18.
Int J Dermatol ; 33(12): 851-5, 1994 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-7883408

RESUMO

BACKGROUND: Delusional parasitosis has been described as a rare syndrome, often involving elderly women who respond poorly to treatment except to pimozide. METHOD: Nineteen cases of delusional parasitosis given antipsychotic treatment other than pimozide were followed up and the responses assessed in a structured manner. RESULTS: The frequency of the syndrome was higher than generally reported and the patients were younger and had been ill for a shorter period. There was good response to antipsychotic treatments using trifluoperazine, haloperidol, chlorpromazine, and electroconvulsive therapy, and 11 cases showed complete remission, five of them maintaining the recovery for more than 3 years. CONCLUSIONS: Delusional parasitosis is not as rare as described: it does not need to be chronic, and can involve young patients. Antipsychotic treatments other than pimozide are equally effective in delusional parasitosis especially if the patients are young and seen early in the illness. The frequency and nature of the disorder observed could probably be due to regional cultural factors.


Assuntos
Antipsicóticos/uso terapêutico , Delusões/diagnóstico , Delusões/tratamento farmacológico , Dermatopatias Parasitárias/psicologia , Adulto , Eletroconvulsoterapia , Feminino , Humanos , Índia , Masculino , Pessoa de Meia-Idade , Pimozida/uso terapêutico , Resultado do Tratamento
19.
Indian J Psychiatry ; 35(3): 189, 1993 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-21743640
20.
Indian J Psychiatry ; 35(4): 218-20, 1993 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21743650

RESUMO

Predominant or specific involvement of the eyes, ears, nostrils, mouth, anus and urethra (the body orifices) has not previously been reported in the literature on delusional parasitosis. Their involvement in the cases reported here is discussed in the context of the Hindu religio-cultural belief system which attaches special significance to these organs in the personal quest for physical, mental and spiritual purity. The involvement of the ears, in particular, appears to be influenced by native healing methods.

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