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1.
Food Res Int ; 122: 361-370, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31229089

RESUMO

Demands for plant-based food and beverage products have escalated in recent years. However, many commercial coffee creamers are still being made using dairy derivatives such as sodium caseinate. Therefore, there is a need to investigate the replacement of dairy based proteins with plant-based alternatives. This study was carried out to systematically investigate the properties of model O/W emulsions stabilized by either sodium caseinate (0.25 to 1.5%) or soy lecithin (0.5 to 1.5%). The model emulsions were made of 10% medium chain triglyceride (MCT) oil-in-water emulsions at pH 7. All model O/W emulsions exhibited whitish appearances similar to that of commercial creamers and were effective at lightening black coffee, except those containing the lowest emulsifier concentrations i.e., 0.25% caseinate or 0.5% lecithin. The lightness of the model emulsions depended on the type and level of emulsifier used, with soy lecithin-stabilized emulsions having similar lightening power compare to that stabilized by sodium caseinate. No feathering or free oil were observed in the whitened coffees at the highest emulsifier level used. Mixtures of caseinate and lecithin emulsifiers were also used and model O/W emulsions with similar physical properties to that stabilized by sodium caseinate alone were produced. The mixed emulsifier-stabilized model emulsions had similar lightness when added to coffee than those stabilized by the individual emulsifiers, suggesting similar stabilization mechanisms using these emulsifiers alone or in combination.


Assuntos
Caseínas/química , Emulsificantes/química , Emulsões/química , Lecitinas/química , Café , Emulsificantes/análise , Manipulação de Alimentos , Modelos Químicos , Tamanho da Partícula
2.
Int J Legal Med ; 133(5): 1477-1483, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30879133

RESUMO

Different sampling techniques can impact on post mortem tryptase levels. A previous study demonstrated significantly lower femoral post mortem total tryptase levels in samples collected via transcutaneous aspiration compared with directly sampling during internal examination. However, an outlier with high tryptase level was noted in one transcutaneous aspiration sample. This 6-month prospective study compared total post mortem tryptase levels between 21 paired aspirated venous and arterial femoral blood samples, and 19 paired aspirated and cutdown femoral venous blood samples in non-anaphylactic deaths only. No statistical differences were demonstrated between the different sampling methods. However, four outlier cases with higher tryptase levels in aspirated arterial and femoral cutdown samples compared with aspirated venous femoral samples were noted. The reasons for the outliers may be due to the bloods collected from these two methods being contaminated by central arterial and venous blood with high tryptase levels respectively. None of the aspirated venous femoral post mortem tryptase levels were above recognized post mortem tryptase cutoff to diagnose anaphylaxis. This study recommends aspirating blood samples from a clamped femoral/external iliac vein for post mortem tryptase analysis should be defined as the gold standard. Further study using the recommended sampling method on post mortem tryptase levels in non-anaphylactic and anaphylactic cases is warranted.


Assuntos
Autopsia/métodos , Coleta de Amostras Sanguíneas/métodos , Triptases/sangue , Adulto , Idoso , Idoso de 80 Anos ou mais , Constrição , Feminino , Artéria Femoral , Veia Femoral , Patologia Legal/métodos , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Adulto Jovem
3.
4.
Forensic Sci Int ; 284: 5-8, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29331682

RESUMO

Serum mast cell tryptase is used to support the diagnosis of anaphylaxis. The recommended clinical cut-off for total tryptase (<11.4µg/L) appears unsuitable in the post mortem setting due to largely unknown processes which result in significantly elevated levels in these samples. Consequently there is no widely accepted tryptase cut-off level for diagnosing an anaphylactic death. This 5-year retrospective study compared total tryptase levels in post mortem femoral blood in anaphylactic deaths and control. Univariate and multivariate analysis was used to assess the relative contribution of other factors (age, gender, post mortem interval, and presence of resuscitation) on post mortem tryptase levels. Nine anaphylactic deaths and 45 controls were identified. Receiver-operating characteristic (ROC) curve analysis identified an optimal cut-off of 53.8µg/L, with sensitivity of 89%, and specificity of 93%, for total post mortem tryptase in femoral blood to diagnosis anaphylaxis. No other factors showed any statistical significant contribution to post mortem tryptase elevation. Femoral total post mortem tryptase level of 53.8µg/L and above is a useful ancillary test in diagnosing an anaphylactic death.


Assuntos
Anafilaxia/diagnóstico , Triptases/sangue , Adolescente , Adulto , Idoso , Estudos de Casos e Controles , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Mudanças Depois da Morte , Estudos Retrospectivos , Sensibilidade e Especificidade , Adulto Jovem
5.
Forensic Sci Int ; 284: 46-52, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29331840

RESUMO

BACKGROUND: The study of post mortem vitreous magnesium (Mg) is less common than sodium (Na), chloride (Cl) and potassium (K) in the forensic literature. There is no accepted normal range for post mortem vitreous Mg and the relationship between post mortem vitreous Mg levels and post mortem interval (PMI), other electrolyte levels, disease conditions, age and sex have not been fully established. AIM: To investigate the relationship of post mortem vitreous Mg with age, sex, PMI, vitreous electrolyte levels and diabetic status. METHODS: A retrospective study of 20 consecutive cases of diabetics and 20 non-diabetic adult deaths was performed. Spearman correlation and the permutation test were used to explore the relationship between post mortem vitreous Mg and continuous and categorical variables respectively. RESULTS: The mean post mortem vitreous Mg was 1.03mmol/L (95%CI: 0.98-1.08mmol/L). The absolute Spearman correlation coefficients (rho) between post mortem vitreous Mg with PMI, age, and other vitreous electrolytes (Na, Cl, and K) ranged between 0.04-0.21 (p>0.19). Post mortem vitreous Mg was statistically higher in diabetics (mean difference: 0.08mmol/L; area-under-the-curve=0.65 on receiver-operator-characteristic curve). No statistical difference was demonstrated between sexes (p=0.92). CONCLUSIONS: In our adult population, post mortem vitreous Mg did not correlate with age, PMI, other vitreous electrolytes (sodium, chloride and potassium) or sex. It was higher in diabetics, however had limited utility as a surrogate marker. Overall, post mortem Mg is steady in the early post mortem period with a mean of 1.03mmol/L.


Assuntos
Magnésio/metabolismo , Mudanças Depois da Morte , Corpo Vítreo/metabolismo , Adulto , Idoso , Estudos de Casos e Controles , Cloretos/metabolismo , Diabetes Mellitus/metabolismo , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Potássio/metabolismo , Estudos Retrospectivos , Sódio/metabolismo , Adulto Jovem
6.
Int J Legal Med ; 132(3): 741-745, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29159510

RESUMO

BACKGROUND: The measurement of mast cell tryptase is commonly used to support the diagnosis of anaphylaxis. In the post-mortem setting, the literature recommends sampling from peripheral blood sources (femoral blood) but does not specify the exact sampling technique. Sampling techniques vary between pathologists, and it is unclear whether different sampling techniques have any impact on post-mortem tryptase levels. AIM: The aim of this study is to compare the difference in femoral total post-mortem tryptase levels between two sampling techniques. METHODS: A 6-month retrospective study comparing femoral total post-mortem tryptase levels between (1) aspirating femoral vessels with a needle and syringe prior to evisceration and (2) femoral vein cut down during evisceration. RESULTS: Twenty cases were identified, with three cases excluded from analysis. There was a statistically significant difference (paired t test, p < 0.05) between mean post-mortem tryptase by aspiration (10.87 ug/L) and by cut down (14.15 ug/L). The mean difference between the two methods was 3.28 ug/L (median, 1.4 ug/L; min, - 6.1 ug/L; max, 16.5 ug/L; 95% CI, 0.001-6.564 ug/L). CONCLUSIONS: Femoral total post-mortem tryptase is significantly different, albeit by a small amount, between the two sampling methods. The clinical significance of this finding and what factors may contribute to it are unclear. When requesting post-mortem tryptase, the pathologist should consider documenting the exact blood collection site and method used for collection. In addition, blood samples acquired by different techniques should not be mixed together and should be analyzed separately if possible.


Assuntos
Manejo de Espécimes/métodos , Triptases/sangue , Adolescente , Adulto , Idoso , Anafilaxia/diagnóstico , Feminino , Artéria Femoral , Veia Femoral , Patologia Legal/métodos , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Adulto Jovem
7.
Forensic Sci Int ; 266: 338-342, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27371799

RESUMO

BACKGROUND: Previous studies in salt water drowning deaths (SWD) demonstrated an observable elevation of post mortem vitreous sodium and chloride (PMVSC) levels. It remains unclear what the underlying mechanism responsible for this change is: whether this is due to rapid electrolyte changes from salt water inhalation/ingestion during drowning or from electrolyte diffusion and/or osmosis across the outer coats of the eyeballs during immersion. A recent animal study using sacrificed bovine eyeballs immersed in salt water demonstrated no significant elevations in PMVSC when immersed for less than one hour. Assuming similar physical properties between human and bovine, we extrapolate that an elevation in PMVSC in SWD with immersion times of less than one hour (SWD-1) would not be from immersion, but from drowning. AIM: Investigate whether there is an elevation in PMVSC in SWD-1. METHODS: Retrospective study comparing PMVSC in SWD-1 with controls from 2012 to 2015 inclusive. RESULTS: PMVSC in SWD-1 was significantly elevated compared with controls. A PMVSC of 259mmol/L has a sensitivity, specificity and likelihood ratio of 0.9, 0.9 and 7.6, respectively. CONCLUSION: The elevation in PMVSC in SWD-1 is due to drowning. A PMVSC of 259mmol/L and above is a reliable ancillary test in diagnosing drowning in bodies immersed in salt water for less than one hour.


Assuntos
Cloretos/análise , Afogamento/diagnóstico , Ciências Forenses/métodos , Sódio/análise , Corpo Vítreo/química , Autopsia , Humanos , Estudos Retrospectivos , Fatores de Tempo
8.
Clin Radiol ; 71(6): 523-31, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-26997429

RESUMO

AIM: To assess trends in medical imaging requests before and after the 4-hour rule commenced and to assess the imaging time component of emergency department (ED) length of stay (LOS). MATERIALS AND METHODS: Retrospective analysis of ED patients and imaging requests 1 year prior to and 3 years after implementation of the 4-hour rule (April to December for 2011-2014) was performed at a single adult tertiary referral Level 1 trauma hospital with Level 6 ED. Logistic regression was used to evaluate trends in the number of ED patient presentations, patient triage categories, and imaging requests for these patients. The imaging component of the total ED LOS was compared for patients who met the 4-hour target and patients who did not. RESULTS: Compared to 2011 (before the 4-hour rule), ED presentations increased 4.74% in 2012, 12.7% in 2013, 21.28% in 2014 (p<0.01). Total imaging requests increased 23.05% in 2012, 48.04% in 2013, 60.77% in 2014 (p<0.01). For patients breaching the 4-hour rule, the mean time before radiology request was 2.4-2.8 hours; mean time from imaging request to completion was 1.2-1.3 hours; mean time from imaging completion to discharge from ED was the longest component of ED LOS (4.9-5.9 hours). CONCLUSIONS: There has been a significant increase in imaging requests, with a trend towards more CT and less radiography requests. Imaging requests for patients who breached the 4-hour target were made on average 2.4-2.8 hours after triage and average time after imaging in itself, exceeded 4 hours. Imaging is not likely a causative factor for patients breaching the 4-hour target.


Assuntos
Diagnóstico por Imagem/estatística & dados numéricos , Serviço Hospitalar de Emergência/estatística & dados numéricos , Tempo de Internação/estatística & dados numéricos , Guias de Prática Clínica como Assunto , Radiologia/normas , Encaminhamento e Consulta/estatística & dados numéricos , Austrália/epidemiologia , Diagnóstico por Imagem/normas , Serviço Hospitalar de Emergência/normas , Fidelidade a Diretrizes/estatística & dados numéricos , Radiologia/estatística & dados numéricos , Revisão da Utilização de Recursos de Saúde , Listas de Espera
9.
Clin Oncol (R Coll Radiol) ; 27(12): 700-7, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26382849

RESUMO

AIMS: Modern chemoradiotherapy used for the treatment of anal cancer has significant acute toxicity. Intensity-modulated radiotherapy (IMRT) may reduce these side-effects. We report our experience implementing IMRT with simultaneous boost at the Sydney Cancer Centre and Royal North Shore Hospital. MATERIALS AND METHODS: We retrospectively collected acute toxicity data on all consecutive patients treated definitively with IMRT between January 2008 and December 2011. Patients received concurrent 5-fluorouracil and mitomycin-C. The radiotherapy dose varied by stage in accordance with the Radiation Therapy Oncology Group (RTOG) 0529 protocol. The first 30 plans were evaluated for adherence to RTOG 0529 dose specifications. Locoregional control and survival outcomes were analysed in July 2014. RESULTS: We included 42 patients (stage I 12%; II 41%; III 45%) with a median follow-up time of 43 months. At 3 years the locoregional control was 94% (95% confidence interval: 78-99), overall survival was 92% (95% confidence interval: 78-97), disease-free survival was 89% (95% confidence interval: 73-96), metastasis-free survival was 89% (95% confidence interval: 73-96) and colostomy-free survival was 89% (95% confidence interval: 72-96). There was no acute grade 4 toxicity. Acute grade 3 toxicity rates were: dermatological (33%), gastrointestinal (14%) and haematological (19%). Twenty-six per cent of patients were hospitalised for treatment-related toxicity. Only 12% required a treatment break greater than 3 days. All patients achieved RTOG 0529 planning target volume dose specifications. Most critical organ dose constraints were either met or met with minor deviation. The exception was 76% major deviation in small bowel constraints. Despite this no increase in gastrointestinal toxicity was observed. CONCLUSIONS: IMRT with simultaneous integrated boost is safe and well tolerated in an unselected population. Most dose specifications are achievable. Excellent locoregional control and survival outcomes are achievable outside of a clinical trial setting.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias do Ânus/terapia , Carcinoma de Células Escamosas/terapia , Quimiorradioterapia/métodos , Implementação de Plano de Saúde , Radioterapia de Intensidade Modulada/métodos , Adulto , Idoso , Neoplasias do Ânus/patologia , Austrália , Carcinoma de Células Escamosas/patologia , Cisplatino/administração & dosagem , Feminino , Fluoruracila/administração & dosagem , Humanos , Masculino , Pessoa de Meia-Idade , Mitomicina/administração & dosagem , Estadiamento de Neoplasias , Prognóstico , Planejamento da Radioterapia Assistida por Computador/métodos , Estudos Retrospectivos , Taxa de Sobrevida
11.
AJNR Am J Neuroradiol ; 35(7): 1425-32, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24676008

RESUMO

BACKGROUND AND PURPOSE: Although most infants with brachial plexus palsy recover function spontaneously, approximately 10-30% benefit from surgical treatment. Pre-operative screening for nerve root avulsions is helpful in planning reconstruction. Our aim was to compare the diagnostic value of CT myelography, MR myelography, and both against a surgical criterion standard for detection of complete nerve root avulsions in birth brachial plexus palsy. MATERIALS AND METHODS: Nineteen patients who underwent a preoperative CT and/or MR myelography and subsequent brachial plexus exploration were included. Imaging studies were analyzed for the presence of abnormalities potentially predictive of nerve root avulsion. Findings of nerve root avulsion on surgical exploration were used as the criterion standard to assess the predictive value of imaging findings. RESULTS: Ninety-five root levels were examined. When the presence of any pseudomeningocele was used as a predictor, the sensitivity was 0.73 for CT and 0.68 for MR imaging and the specificity was 0.96 for CT and 0.97 for MR imaging. When presence of pseudomeningocele with absent rootlets was used as the predictor, the sensitivity was 0.68 for CT and 0.68 for MR imaging and the specificity was 0.96 for CT and 0.97 for MR imaging. The use of both CT and MR imaging did not increase diagnostic accuracy. Rootlet findings in the absence of pseudomeningocele were not helpful in predicting complete nerve root avulsion. CONCLUSIONS: Findings of CT and MR myelography were highly correlated. Given the advantages of MR myelography, it is now the single technique for preoperative evaluation of nerve root avulsion at our institution.


Assuntos
Neuropatias do Plexo Braquial/diagnóstico , Plexo Braquial/diagnóstico por imagem , Plexo Braquial/patologia , Imageamento por Ressonância Magnética/métodos , Radiculopatia/diagnóstico , Tomografia Computadorizada por Raios X/métodos , Neuropatias do Plexo Braquial/etiologia , Feminino , Humanos , Recém-Nascido , Doenças do Recém-Nascido/diagnóstico , Doenças do Recém-Nascido/etiologia , Masculino , Mielografia/métodos , Radiculopatia/complicações , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
12.
Hong Kong Med J ; 16(6): 484-6, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21135427

RESUMO

Proptosis is commonly encountered in clinical practice. We report on a patient with acute proptosis, eyelid swelling, and chemosis, which was initially treated as cellulitis. After radiological and pathological assessments, a diagnosis of large B-cell lymphoma was made. The patient died within 2 months of presentation. Not all patients with proptosis have cellulitis. Proptosis, especially unilateral proptosis, should always lead to a radiological scan in case of malignancy.


Assuntos
Linfoma Difuso de Grandes Células B/diagnóstico , Celulite Orbitária/diagnóstico , Idoso , Humanos , Linfoma Difuso de Grandes Células B/patologia , Masculino , Celulite Orbitária/patologia
13.
Eye (Lond) ; 24(11): 1675-80, 2010 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-20689570

RESUMO

PURPOSE: To analyse the long-term visual acuity (VA) and intraocular pressure (IOP) outcomes in phacomorphic glaucoma. PATIENTS AND METHODS: A retrospective analysis of 100 consecutive, acute phacomorphic glaucoma cases from January 2000 to April 2009 was conducted at The Caritas Medical Centre in Hong Kong. All cases underwent cataract extraction after IOP control with medication and/or laser. RESULTS: During a 3.1±2.6-year follow-up, the mean visual improvement was 1.1±0.9 LogMAR units with improvements in 81.7% of cases. A shorter duration from symptoms to cataract extraction resulted in greater visual improvement (r(2)=0.1, P=0.001). In all, 80.5% of the cases had IOP≤21 mm Hg without any glaucoma treatment; 19.5% required 1.6±0.7 glaucoma eye drops; and 3.7% required additional laser iridotomy or trabeculectomy for IOP control at 1.8±2.3 years. The vertical cup-disc ratio (VCDR) of the index eye was 0.6±0.3. Gonioscopy revealed an averaged Shaffer grading of 3.0±1.0 and 99±90 degrees of peripheral anterior synechiae (PAS). The Humphrey automated perimetry mean deviation was 5.2±2.7 and the pattern standard deviation was -15.9±10. CONCLUSION: Over 80% of phacomorphic patients had long-term visual improvements and normalization of IOP after cataract extraction. A shorter attack seemed to offer better VA. Post-operatively, most have open angles with some degree of PAS formation, and glaucomatous optic neuropathy is evident from enlarged VCDRs and visual field defects. At least 2 years of follow-up is useful to detect a 20% glaucoma progression possibly requiring additional glaucoma treatments.


Assuntos
Extração de Catarata , Glaucoma de Ângulo Aberto/fisiopatologia , Pressão Intraocular/fisiologia , Acuidade Visual/fisiologia , Doença Aguda , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Seguimentos , Glaucoma de Ângulo Aberto/terapia , Hong Kong , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Tonometria Ocular , Campos Visuais/fisiologia
14.
J Med Imaging Radiat Oncol ; 53(2): 234-9, 2009 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-19527373

RESUMO

Malignant myoepithelioma of the breast (MMB) is a rare and often aggressive disease with poor prognosis. Little is known regarding its optimal treatment and progression. We describe the clinical history of a woman following excision of a benign adenomyoepithelioma which recurred years later as a radioresistant malignant myoepithelioma with high levels of ataxia telangiectasia mutated protein and mutant p53 (Cys135Phe). MMB requires close follow-up and aggressive treatment. If adjuvant radiotherapy is adopted to improve local control, minimal postoperative delay and higher doses than for standard post-mastectomy radiation are recommended.


Assuntos
Neoplasias da Mama/metabolismo , Neoplasias da Mama/radioterapia , Proteínas de Ciclo Celular/análise , Proteínas de Ligação a DNA/análise , Mioepitelioma/radioterapia , Proteínas Serina-Treonina Quinases/análise , Proteínas Supressoras de Tumor/análise , Proteínas Mutadas de Ataxia Telangiectasia , Feminino , Humanos , Pessoa de Meia-Idade , Falha de Tratamento
15.
Crit Rev Oncol Hematol ; 67(2): 113-23, 2008 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-18308583

RESUMO

Technical advancements in radiation therapy (RT) have facilitated the safe delivery of conformal, dose-escalated radiation to a wide spectrum of hepatocellular carcinoma (HCC) patients. A variety of doses and RT fractionation schemes have been used, and RT has been used in combination with transarterial chemoembolization (TACE). Compared to untreated historical controls or those treated with TACE alone, outcomes following RT alone or TACE and RT are better. Despite advances in RT delivery, liver toxicity following RT remains a dose-limiting factor, and investigations to better understand the pathophysiology of RT-induced liver toxicity are warranted. For most tumors, RT can provide sustained local control. However, HCC tends to recur within the liver away from the irradiated volume, providing rationale for combining RT with systemic or regional therapies. There is a particular interest in combining RT with anti-VEGF-targeted agents for their independent activity in HCC as well as their radiation sensitization properties. Randomized trials of RT are warranted.


Assuntos
Carcinoma Hepatocelular/radioterapia , Neoplasias Hepáticas/radioterapia , Radioterapia Conformacional/métodos , Quimioembolização Terapêutica , Radioterapia com Íons Pesados , Humanos , Fígado/efeitos da radiação , Terapia com Prótons , Radiocirurgia
16.
Br J Plast Surg ; 56(1): 59-62, 2003 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-12706157

RESUMO

We present the case of a patient with arterial thrombosis of a free TRAM flap 11 days after surgery. Initial salvage involved thrombectomy through an arteriotomy using a Fogarty catheter. Subsequent return to the operating theatre was necessary because of further vascular compromise. Thrombectomy was combined with flap thrombolysis and anticoagulation, and the flap remained viable at 6 months. Although rates of successful salvage vary, the literature indicates that flaps are rarely saved if signs of compromise present later than 2 days postoperatively. This case demonstrates that aggressive salvage may be successful even in cases of 'late' vascular compromise.


Assuntos
Neoplasias da Mama/cirurgia , Carcinoma Ductal de Mama/cirurgia , Complicações Pós-Operatórias/terapia , Terapia de Salvação/métodos , Retalhos Cirúrgicos , Trombose/terapia , Adulto , Cateterismo , Feminino , Humanos , Mastectomia Radical Modificada/métodos , Microcirurgia/métodos
17.
Eur J Immunol ; 31(12): 3557-66, 2001 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11745375

RESUMO

Detection of the functional CD8(+) CTL response usually requires in vitro restimulation. The differences between the CD8(+) CTL repertoire in freshly isolated precursor cells and CD8(+) CTL after short-term in vitro expansion have been generally assumed to be minimal, but have never been defined experimentally. Using staining with P18-I10/H-2D(d) tetramers and monoclonal antibodies (mAb) against Vbeta, we show the surprising result that there was significant skewing of the CD8(+) CTL repertoire after just 7 days of stimulation. In contrast, we found that overnight incubation of precursor cells with peptide allows the functional assessment of CD8(+) CTL (which cannot be detected ex vivo from freshly isolated cells) without changing the absolute number of antigen-specific CTL as measured by tetramer staining or the repertoire of TCR analyzed with mAb. This study affords a better understanding of the differences between the ex vivo and in vitro stimulated CTL repertoire, and provides an approach to reveal a more faithful representation of the functional in vivo CTL response without skewing of the repertoire of T cells detected.


Assuntos
Células-Tronco Hematopoéticas/imunologia , Ativação Linfocitária , Linfócitos T Citotóxicos/imunologia , Animais , Feminino , Proteína gp160 do Envelope de HIV/imunologia , HIV-1/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Receptores de Antígenos de Linfócitos T alfa-beta/análise
18.
Eur J Immunol ; 31(10): 2951-9, 2001 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11592071

RESUMO

The ability of CD8+ cytotoxic T lymphocytes (CTL) to clear viral infections may be limited when high avidity CTL encounter supra-optimal antigen density on antigen-presenting cells (APC) and undergo antigen-dependent apoptosis of CTL (ADAC). Previously, we have shown ADAC in CD8+ populations to be Fas independent, TNF-alpha receptor 2 (TNFR2) mediated, caspase dependent, and accompanied by a decrease in Bcl-2. We now employ flow cytometry to follow ADAC within individual CD8+ cells to demonstrate that the intense TCR signal induced in high avidity CTL by supra-optimal antigen density results 8 - 16 h later in a caspase-independent TNFR2 down-modulation that is directly related to the stimulating APC antigen density and concludes in a rapid onset of apoptosis by 18 - 24 h. Individual CTL undergoing apoptosis exhibit a dramatic and concurrent: (1) positive staining with Annexin V and propidium iodide; (2) transformation to a smaller cell size characteristic of apoptosis; and (3) a nearly complete loss of Bcl-2, c-IAP1, and TRAF2. We conclude that the antigen-dependent apoptosis of CD8+ CTL occurs when a tandem TCR/TNFR2 signal initiates an abrupt and concordant onset of multiple apoptotic events.


Assuntos
Antígenos/imunologia , Apoptose , Linfócitos T CD8-Positivos/fisiologia , Animais , Anexina A5/análise , Antígenos CD/fisiologia , Inibidores de Caspase , Caspases/fisiologia , Regulação para Baixo , Camundongos , Camundongos Endogâmicos BALB C , Proteínas/análise , Proteínas Proto-Oncogênicas c-bcl-2/análise , Receptores de Antígenos de Linfócitos T/fisiologia , Receptores do Fator de Necrose Tumoral/fisiologia , Receptores Tipo II do Fator de Necrose Tumoral , Fator 2 Associado a Receptor de TNF , Fator de Necrose Tumoral alfa/fisiologia
19.
J Endovasc Ther ; 8(1): 62-6, 2001 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11220471

RESUMO

PURPOSE: To report a case of bilateral simultaneous percutaneous transluminal angioplasty and stenting of the intracranial vertebral arteries prior to staged bilateral carotid endarterectomy. CASE REPORT: A 68-year-old man presented with a 3-month history of recurrent, intermittent left-sided weakness and diplopia. Imaging defined bilateral 80% to 99% internal carotid artery stenoses and >90% stenoses of both distal vertebral arteries at the level of the foramen magnum. Bilateral intracranial vertebral artery stenting was performed, followed by staged carotid endarterectomies. No complications occurred, and the patient recovered uneventfully from all 3 procedures. He remains symptom- and event-free 20 months later. CONCLUSIONS: Our initial success in this case indicates a role for percutaneous transluminal angioplasty and stenting as an alternative to open surgery for intracranial vertebral artery stenosis.


Assuntos
Angioplastia Coronária com Balão , Arteriopatias Oclusivas/terapia , Artérias Carótidas/cirurgia , Endarterectomia , Cuidados Pré-Operatórios , Stents , Artéria Vertebral , Idoso , Arteriopatias Oclusivas/diagnóstico por imagem , Angiografia Cerebral , Humanos , Masculino
20.
J Immunol ; 166(3): 1690-7, 2001 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-11160212

RESUMO

Previously, we observed that high-avidity CTL are much more effective in vivo than low-avidity CTL in elimination of infected cells, but the mechanisms behind their superior activity remained unclear. In this study, we identify two complementary mechanisms: 1) high-avidity CTL lyse infected cells earlier in the course of a viral infection by recognizing lower Ag densities than those distinguished by low-avidity CTL and 2) they initiate lysis of target cells more rapidly at any given Ag density. Alternative mechanisms were excluded, including: 1) the possibility that low-avidity CTL might control virus given more time (virus levels remained as high at 6 days following transfer as at 3 days) and 2) that differences in efficacy might be correlated with homing ability. Furthermore, adoptive transfer of high- and low-avidity CTL into SCID mice demonstrated that transfer of a 10-fold greater amount of low-avidity CTL could only partially compensate for their decreased ability to eliminate infected cells. Thus, we conclude that high-avidity CTL exploit two complementary mechanisms that combine to prevent the spread of virus within the animal: earlier recognition of infected cells when little viral protein has been made and more rapid lysis of infected cells.


Assuntos
Testes Imunológicos de Citotoxicidade , Citotoxicidade Imunológica , Subpopulações de Linfócitos T/imunologia , Subpopulações de Linfócitos T/virologia , Linfócitos T Citotóxicos/imunologia , Linfócitos T Citotóxicos/virologia , Transferência Adotiva , Animais , Apresentação de Antígeno , Linhagem Celular , Movimento Celular/imunologia , Células Clonais , Testes Imunológicos de Citotoxicidade/métodos , Feminino , Antígenos HIV/genética , Antígenos HIV/imunologia , Antígenos HIV/metabolismo , Proteína gp160 do Envelope de HIV/genética , Proteína gp160 do Envelope de HIV/imunologia , Proteína gp160 do Envelope de HIV/metabolismo , Cinética , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos DBA , Camundongos SCID , Doenças Ovarianas/imunologia , Doenças Ovarianas/virologia , Fragmentos de Peptídeos/genética , Fragmentos de Peptídeos/imunologia , Fragmentos de Peptídeos/metabolismo , Subpopulações de Linfócitos T/metabolismo , Subpopulações de Linfócitos T/transplante , Linfócitos T Citotóxicos/metabolismo , Linfócitos T Citotóxicos/transplante , Células Tumorais Cultivadas , Vacínia/imunologia , Vacínia/virologia , Vaccinia virus/genética , Vaccinia virus/imunologia , Carga Viral
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