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1.
Ann Acad Med Singap ; 34(10): 639-41, 2005 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-16382251

RESUMO

INTRODUCTION: Dural sinus thrombosis following minor head injury is rare. We report such a case in a child after mild head injury. CLINICAL PICTURE: A 4-year-old child presented with giddiness and vomiting after a fall. Clinical examination was unremarkable. Magnetic resonance venogram revealed thrombosis of the right sigmoid and transverse sinuses. TREATMENT: The patient was managed conservatively. OUTCOME: Repeat scans 10 weeks after injury showed recanalisation of the thrombosis. CONCLUSION: Dural sinus thrombosis should be excluded in children presenting with persistent giddiness and vomiting after minor head injury.


Assuntos
Traumatismos Craniocerebrais/complicações , Trombose dos Seios Intracranianos/etiologia , Pré-Escolar , Traumatismos Craniocerebrais/diagnóstico por imagem , Diagnóstico Diferencial , Feminino , Seguimentos , Humanos , Flebografia , Trombose dos Seios Intracranianos/diagnóstico por imagem , Tomografia Computadorizada por Raios X , Índices de Gravidade do Trauma
2.
Forensic Sci Int ; 49(1): 43-56, 1991.
Artigo em Inglês | MEDLINE | ID: mdl-1851715

RESUMO

Results obtained from three commercial immunoassay kits, Abuscreen, TDx, and EMIT, commonly used for the initial test of urine cannabinoids (and metabolites) were correlated with the 11-nor-delta 9-tetrahydrocannabinol-9-carboxylic acid (9-THC-COOH) concentration as determined by GC/MS. Correlation coefficients obtained based on 26 (out of 1359 total sample population) highly relevant samples, are 0.601 and 0.438 for Abuscreen and TDx. Correlation coefficients obtained from a parallel study on a different set of 47 (out of 5070 total sample population) highly relevant specimens are 0.658 and 0.575 for Abuscreen and Emit. The immunoassay concentration levels, that correspond to the commonly used 15 ng/ml GC/MS cutoff value for 9-THC-COOH, as calculated from the regression equations are 82 ng/ml and 75 ng/ml for TDx and EMIT and 120 ng/ml and 72 ng/ml for Abuscreen manufactured at two different time periods. The difference of these calculated corresponding concentrations provides quantitative evidence of the reagent specificity differences.


Assuntos
Canabinoides/urina , Dronabinol/análogos & derivados , Dronabinol/urina , Imunoensaio de Fluorescência por Polarização , Cromatografia Gasosa-Espectrometria de Massas , Humanos , Técnicas Imunoenzimáticas , Valor Preditivo dos Testes , Radioimunoensaio , Reprodutibilidade dos Testes
3.
J Forensic Sci ; 36(5): 1331-41, 1991 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-1955829

RESUMO

A rapid and effective solid-phase extraction procedure using Bond Elute Certify bonded silica sorbent cartridges was adopted to extract amphetamine, methamphetamine, and 3,4-methylenedioxymethamphetamine (MDMA or Ecstasy) from urine samples. The extract was derivatized with trichloroacetic anhydride prior to gas chromatography/mass spectrometry (GC/MS) analysis with selected ion monitoring of the following ions: 190, 91, 188; 204, 91, 202; 162, 135, 202; 194, 123; and 211, 209 for the derivatized amphetamine, methamphetamine, MDMA, d5-amphetamine, and d9-methamphetamine, respectively. The first of the ions listed for each compound was used for quantitation. The compound d5-amphetamine was used as the internal standard for amphetamine, and d9-methamphetamine was used for methamphetamine and MDMA. Results showed a higher than 65% recovery and a reproducibility with less than a 5% coefficient of variation. When a sample size of 2 mL was used, the lowest detectable concentration was about 50 ng/mL, and a near-perfect fit can be obtained (within the 250 to 4000-ng/mL concentration range studied) using a second-order polynomial model.


Assuntos
3,4-Metilenodioxianfetamina/urina , Anfetamina/urina , Metanfetamina/urina , Calibragem , Cromatografia Gasosa-Espectrometria de Massas , Humanos , Valor Preditivo dos Testes , Reprodutibilidade dos Testes
4.
Ann Acad Med Singap ; 33(1): 63-7, 2004 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-15008565

RESUMO

INTRODUCTION: In line with other established protocols, our unit has instituted a standardised protocol for the management of moderate and severe traumatic brain injury since 1996 in our neurointensive care unit. MATERIALS AND METHODS: We reviewed the outcomes, at 6 months' post-injury, in an elderly group aged > or = 64 years (73.86 +/- 8.0 years) and compared them to a younger group aged 20 to 40 years (29.2 +/- 5.7 years) in a cohort of 324 patients. Outcome was dichotomised as favourable (mild and moderate disability but independent; Glasgow Outcome Score [GOS] 4 and 5), unfavourable (severe disability and persistent vegetative state; GOS 2 and 3) and death (GOS 1). RESULTS: In the elderly group, the mortality (55.4%) was slightly more than double that of the younger group (20.9%); 21.5% had an unfavourable outcome (14.2% in the younger group) and only 23% had a favourable outcome (compared to 64.9% in the younger group). The final outcomes were significantly worse in all levels in the elderly group. This was in spite of data showing that the mechanism of injury was of a higher impact in the younger group, with a higher incidence of polytrauma and cervical spine injury. On admission, the mean Glasgow Coma Score (GCS) was 8.3 +/- 3.91 for the elderly group and 8.59 +/- 4.05 for the younger group (P = 0.763). Computed tomography scan showed that the elderly had a higher incidence of mass lesions (extradural haematoma and subdural haematoma) and traumatic subarachnoid haemorrhage. A subgroup (29.2%) of elderly patients had no surgical intervention based on poor clinical/neurological status, premorbid functional status and pre-existing medical conditions, with their family's consent. The GCS of < or = 8, on admission, was significant (P <0.001) in predicting mortality in the elderly. In the elderly group, the female gender had a higher mortality rate (70.4%) than the males (44.7%) (P = 0.19). CONCLUSION: Age must be considered an independent factor in outcome prediction in the elderly with moderate and severe traumatic brain injury. A more conservative approach in the management of an elderly patient with severe head injury may be reasonable given its dismal outcomes after careful dialogue with the relatives.


Assuntos
Lesões Encefálicas/terapia , Adulto , Toxina da Cólera , Feminino , Escala de Coma de Glasgow , Escala de Resultado de Glasgow , Hematoma Epidural Craniano/terapia , Hematoma Subdural/terapia , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Singapura , Resultado do Tratamento
5.
Singapore Med J ; 51(6): e98-102, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-20658100

RESUMO

Bilateral vestibular schwannomas are the diagnostic features of neurofibromatosis type 2 (NF-2), and are the most common findings associated with the disorder. We report a three-year-old boy who presented with left facial nerve palsy and weight loss with bilateral large cerebellopontine (CP) angle masses that extended into the internal auditory canal on magnetic resonance imaging. The patient also had synchronous tumours in the lateral ventricle and intradural extramedullary spinal canal. The above findings were misinterpreted as NF-2 with bilateral vestibular schwannomas, ventricular meningioma and spinal schwannomas/meningiomas. However, histological examination of the spinal masses revealed a primitive neuroectodermal tumour. Although bilateral CP angle masses are characteristic of NF-2, the possibility of diffuse craniospinal malignancy should be considered in a very young child who presents with weight loss and extensive tumours.


Assuntos
Tumores Neuroectodérmicos Primitivos/diagnóstico , Neurofibromatose 2/diagnóstico , Pré-Escolar , Diagnóstico Diferencial , Paralisia Facial/patologia , Evolução Fatal , Humanos , Imageamento por Ressonância Magnética/métodos , Masculino , Metástase Neoplásica , Tumores Neuroectodérmicos Primitivos/patologia , Redução de Peso
7.
J Biomed Mater Res A ; 85(3): 605-10, 2008 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-17806119

RESUMO

Robust attachment of active proteins to synthetic surfaces underpins the development of biosensors and protein arrays. This paper presents the results of experiments in which energetic ions, extracted from an inductively coupled nitrogen plasma, are used to modify the surface of ultrahigh molecular weight polyethylene (UHMWPE). The ability of the surface to bind active horseradish peroxidase (HRP) is significantly enhanced by the plasma treatment. The amide signal in infrared spectroscopy indicates an increased quantity of surface-attached protein on the modified surface. The activity of the bound HRP remains high compared with that of protein attached to the untreated surface, after repeated washing in buffer solution. Although Tween 20 was an effective blocking agent for the unmodified polyethylene surface, binding of HRP to the modified surface is not inhibited by its presence. We propose that the treatment produces new binding sites on the surface and that the function of the HRP is retained because the treated surface is substantially more hydrophilic.


Assuntos
Enzimas Imobilizadas/química , Peroxidase do Rábano Silvestre/química , Polietileno/química , Sítios de Ligação , Biotecnologia/métodos , Ligação Proteica , Propriedades de Superfície
8.
Langmuir ; 23(5): 2741-6, 2007 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-17243737

RESUMO

Surface attachment of the enzyme horseradish peroxidase (HRP) was studied on untreated and ion beam implanted polystyrene (PS) films. The PS films of 100 nm thickness on a silicon wafer were treated using the plasma immersion ion implantation (PIII) technique, with argon ions of energy 20 keV and fluences of up to 2 x 10(16) ions/cm2. Differential transmittance Fourier transform infrared (FTIR) spectra confirmed the presence of proteins on the PS surfaces by detection of the amide A, I, and II protein vibrations. Spectroscopic ellipsometry over the UV-vis spectral region provided the optical constants and thickness of the protein layer, while tapping mode atomic force microscopy (AFM) was used to image the protein distribution on the surface. The combination of AFM, ellipsometry, and FTIR analysis showed that, on the untreated PS surface, HRP formed islands 8 nm in height and 30 nm in lateral size, covering approximately 27% of the PS surface. After PIII modification of the PS surface, the protein covered 100% of the surface area.


Assuntos
Microscopia de Força Atômica/métodos , Poliestirenos/química , Proteínas/química , Materiais Biocompatíveis , Físico-Química/métodos , Peroxidase do Rábano Silvestre/química , Íons , Modelos Estatísticos , Ligação Proteica , Espectroscopia de Infravermelho com Transformada de Fourier/métodos , Propriedades de Superfície , Fatores de Tempo
9.
Clin Chem ; 37(9): 1595-601, 1991 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-1893596

RESUMO

Enzymatic digestion with beta-glucuronidase (EC 3.2.1.31) was used to release intact oxazepam from urine samples containing the d5-analog internal standard. The resulting specimens were extracted with Du Pont PREP Type W cartridge (processed by a PREP Automated Sample Processor), Bond Elut Certify, and J.T. Baker "spe" columns for comparison of the columns' extraction recovery and overall effectiveness. Methyl iodide/tetrahexylammonium hydrogen sulfate and N,O-bis(trimethylsilyl)trifluoroacetamide/trimethylchlorosilane (10 g/L) were used for the methylation and trimethylsilylation studies. We used a Hewlett-Packard HP 5790 mass-selective detector equipped with a 13-m J & W DB-5 column (5% phenyl polysiloxane phase) for gas chromatography/mass spectroscopy (GC/MS) analysis and the Thru-Put Target software package for data processing. After several exploratory experiments, we adopted the Du Pont PREP system methylation procedure because of its effective recovery, the superior stability of the derivatization product, the possibility of incorporating a clean-up step, and the potential for high throughput. The extraction recovery from a set of control samples was 87%. Coefficients of variation obtained for six replicates of GC/MS analysis and for the overall procedure were 1% and 3%, respectively. Excellent linearity was established in the 50-8000 micrograms/L concentration range studied. With the use of 3-mL samples, a 20-microL final reconstitution volume, oxazepam at 50 micrograms/L was easily detected under the adopted operation conditions.


Assuntos
Glucuronidase/metabolismo , Oxazepam/urina , Benzodiazepinas/metabolismo , Biotransformação , Cromatografia Gasosa-Espectrometria de Massas , Humanos , Metilação , Oxazepam/farmacocinética , Reprodutibilidade dos Testes , Silanos/química
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