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1.
Cureus ; 16(2): e54588, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38524093

RESUMO

BACKGROUND: The information on healthcare expenditure is crucial to know the impact of the pandemic on public health budgets, thereby correctly managing the ongoing crisis and preparing for subsequent waves. OBJECTIVE: To estimate the length of stay and cost incurred on COVID-19 patients who died in the ICU. METHODS: It is a record-based descriptive study conducted on 76 deceased COVID-19 patients admitted to the ICU of a dedicated COVID-19 hospital (DCH) between April and October 2020. Central Government Health Services (CGHS) package rate list, Delhi-NCR, was used as a reference for the cost of the ICU bed, ventilator, investigations, and procedures. RESULTS: The median duration of stay in the hospital was 12 days, and in the ICU, it was eight days. The median total cost of managing the patient was 91,235.6 INR; of this, the median total cost for ICU stay per patient was 6,904 INR. The major proportion of total expenses was contributed by personal protective equipment (PPE) kits, an average of 11,091.33 INR per month. The median cost of stay in the ICU, on the ventilator, in the ward, and mean cost of investigations were higher among those with associated co-morbidities. CONCLUSION: Most elderly male with co-morbidities lost their battle after ventilator support in the ICU. Patients with co-morbidities and severe disease not only have a long duration of hospitalization and poor survival rate but also fetch an economic burden close to one lakh on the institute.

4.
J Chem Phys ; 149(19): 194303, 2018 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-30466269

RESUMO

The interaction of fast protons (velocity between 1.41 and 2.4 a.u.) with naphthalene and azulene is investigated as a model of an ion-polycyclic aromatic hydrocarbon interaction system. Production of various intact and fragment ions in coincidence with electron emission, electron transfer to projectile, or both is analyzed. The two targets being isomers, the rather obvious similarity in the fundamental ion-molecule collision energetics is quantitatively verified. The fast isomerization processes of cationic azulene are observed to be influencing its further dissociation channels such as C2H2 and H eliminations. A first ever attempt is presented here wherein single plasmon excitation in conjunction with isomerization dynamics is reported. Evidence from dication evaporation energetics is used to invoke the double plasmon excitation model. A model based on the multiplasmon resonance explains the observed proton velocity dependence of double to single ionization cross sections. Moreover an attempt is made to reinforce the proposition of double plasmon excitation by explaining the observed suppression of neutral H loss from dications as opposed to monocations.

5.
Anim Genet ; 49(6): 564-570, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30311254

RESUMO

The Functional Annotation of Animal Genomes (FAANG) project aims to identify genomic regulatory elements in both sexes across multiple stages of development in domesticated animals. This study represents the first stage of the FAANG project for the horse, Equus caballus. A biobank of 80 tissue samples, two cell lines and six body fluids was created from two adult Thoroughbred mares. Ante-mortem assessments included full physical examinations, lameness, ophthalmologic and neurologic evaluations. Complete blood counts and serum biochemistries were also performed. At necropsy, in addition to tissue samples, aliquots of serum, ethylenediaminetetraacetic acid (EDTA) plasma, heparinized plasma, cerebrospinal fluid, synovial fluid, urine and microbiome samples from all regions of the gastrointestinal and urogenital tracts were collected. Epidermal keratinocytes and dermal fibroblasts were cultured from skin samples. All tissues were grossly and histologically evaluated by a board-certified veterinary pathologist. The results of the clinical and pathological evaluations identified subclinical eosinophilic and lymphocytic infiltration throughout the length of the gastrointestinal tract as well as a mild clinical lameness in both animals. Each sample was cryo-preserved in multiple ways, and nuclei were extracted from selected tissues. These samples represent the first published systemically healthy equine-specific biobank with extensive clinical phenotyping ante- and post-mortem. The tissues in the biobank are intended for community-wide use in the functional annotation of the equine genome. The use of the biobank will improve the quality of the reference annotation and allow all equine researchers to elucidate unknown genomic and epigenomic causes of disease.


Assuntos
Bancos de Espécimes Biológicos , Genômica , Cavalos/genética , Animais , Feminino , Fenótipo
6.
Anim Genet ; 49(5): 457-460, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-29999543

RESUMO

Squamous cell carcinoma (SCC) is the most common cancer affecting the equine eye, with a higher incidence documented in Haflinger horses. Recently, a missense variant in the gene damage specific DNA binding protein 2 (DDB2, p.Thr338Met) on ECA12 was identified as a risk factor for the development of limbal SCC in Haflinger horses. SCC also occurs on the nictitating membrane; therefore, investigating the role of this missense variant in nictitating membrane SCC is warranted. In this study, a common ancestor was identified among Haflinger horses affected with limbal SCC or with nictitating membrane SCC, thus supporting a recessive risk factor for the development of cancer at both ocular locations. Analysis of genotype data from Haflinger horses with and without nictitating membrane SCC revealed that the same region on ECA12 associated with limbal SCC was also associated with nictitating membrane SCC (P < 2.04 × 10-5 ). Fine mapping of this locus using 25 cases and 49 controls supported the hypothesis that DDB2:c.1013C>T, p.Thr338Met, is a risk factor for nictitating membrane SCC, as 88% of our cases were homozygous for this variant and no other polymorphism was more strongly associated (P = 4.13 × 10-14 ). These data indicate that the genetic risk is the same for the development of both limbal and nictitating membrane SCC in Haflinger horses and validates utilization of genetic testing of the DDB2 variant for both clinical management and the guidance of mating decisions.


Assuntos
Carcinoma de Células Escamosas/veterinária , Neoplasias Oculares/veterinária , Doenças dos Cavalos/genética , Animais , Carcinoma de Células Escamosas/genética , Cromossomos de Mamíferos , Proteínas de Ligação a DNA/genética , Neoplasias Oculares/genética , Cavalos , Limbo da Córnea/patologia , Proteínas Associadas aos Microtúbulos/genética , Membrana Nictitante/patologia , Polimorfismo de Nucleotídeo Único
7.
Proc Natl Acad Sci U S A ; 115(21): 5392-5396, 2018 05 22.
Artigo em Inglês | MEDLINE | ID: mdl-29735712

RESUMO

A central mystery in high-temperature superconductivity is the origin of the so-called strange metal (i.e., the anomalous conductor from which superconductivity emerges at low temperature). Measuring the dynamic charge response of the copper oxides, [Formula: see text], would directly reveal the collective properties of the strange metal, but it has never been possible to measure this quantity with millielectronvolt resolution. Here, we present a measurement of [Formula: see text] for a cuprate, optimally doped Bi2.1Sr1.9CaCu2O8+x (Tc = 91 K), using momentum-resolved inelastic electron scattering. In the medium energy range 0.1-2 eV relevant to the strange metal, the spectra are dominated by a featureless, temperature- and momentum-independent continuum persisting to the electronvolt energy scale. This continuum displays a simple power-law form, exhibiting q2 behavior at low energy and q2/ω2 behavior at high energy. Measurements of an overdoped crystal (Tc = 50 K) showed the emergence of a gap-like feature at low temperature, indicating deviation from power law form outside the strange-metal regime. Our study suggests the strange metal exhibits a new type of charge dynamics in which excitations are local to such a degree that space and time axes are decoupled.

8.
Pharmacogenomics J ; 17(3): 242-251, 2017 06.
Artigo em Inglês | MEDLINE | ID: mdl-26951882

RESUMO

CYP1A1 gene is involved in estrogen metabolism, and previously, we have reported association of variant rs2606345 with altered anti-epileptic drugs (AED) response in North Indian women with epilepsy (WWE). The present study aims to replicate the pharmacogenetic association, perform functional characterization and study its distribution within ethnically diverse Indian population. The variant was genotyped in 351 patients to assess the pharmacogenetic association and 552 healthy individuals belonging to 24 different ethnic groups to examine the distribution in Indian population. We observed significant overrepresentation of 'A' allele and 'AA' genotype in poor responders in WWE at Bonferroni-corrected significance levels. The recessive allele was found to lower the promoter activity by ~70-80% which was further substantiated by thermally less stable hairpin formed by it (ΔTm=7 °C). Among all ethnic groups, west Indo-European (IE-W-LP2) subpopulation showed highest genotypic frequency of the variant making women from this community more prone to poor AED response. Our results indicate that rs2606345 influences drug response in WWE by lowering CYP1A1 expression.


Assuntos
Anticonvulsivantes/uso terapêutico , Citocromo P-450 CYP1A1/genética , Epilepsia/tratamento farmacológico , Variantes Farmacogenômicos , Adolescente , Adulto , Anticonvulsivantes/efeitos adversos , Estudos de Casos e Controles , Citocromo P-450 CYP1A1/metabolismo , Epilepsia/enzimologia , Epilepsia/etnologia , Epilepsia/genética , Feminino , Frequência do Gene , Células HEK293 , Heterozigoto , Homozigoto , Humanos , Índia/epidemiologia , Células MCF-7 , Masculino , Farmacogenética , Testes Farmacogenômicos , Fenótipo , Regiões Promotoras Genéticas , Grupos Raciais/genética , Recidiva , Transfecção , Resultado do Tratamento , Adulto Jovem
9.
Ir J Med Sci ; 185(4): 913-919, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27585806

RESUMO

OBJECTIVE: To ascertain whether house officers (HOs) attain a more satisfactory surgical rotation experience when they perform basic surgical learning activities. We also sought to establish how many and which learning activities HOs achieve and the effect on their surgical experience. METHODOLOGY: A questionnaire listing 20 learning activities and questions regarding satisfaction with an overall experience was disseminated to HOs in the UK and Ireland who had completed ≥3 months of surgical rotations. Satisfaction with surgical experience was dichotomised in order to perform logistic regression using R Studio software v0.98. RESULTS: The survey was completed by 150 respondents, with 26 % completing at least 10 basic surgical learning activities during their surgical rotation. On multivariate analysis, the completion of these learning activities was significantly associated with a satisfactory rotation experience (p < 0.001). Furthermore, the use of a checklist of surgical activities provided to HOs was associated with a significant increase in the performance of learning activities (p = 0.003). CONCLUSION: Surgical HOs who were informed about potential basic surgical learning activities that can be performed during their rotations performed significantly more of these activities. And these activities were associated with a significantly greater satisfaction with surgical rotations. Therefore, we recommend facilitating HOs completion of these activities as this will ensure that basic surgical competencies are achieved and that HOs will be more satisfied with their surgical experience.


Assuntos
Educação de Pós-Graduação em Medicina/métodos , Cirurgia Geral/educação , Corpo Clínico Hospitalar/educação , Estudos de Casos e Controles , Lista de Checagem , Competência Clínica/normas , Cirurgia Geral/normas , Humanos , Capacitação em Serviço/métodos , Irlanda , Aprendizagem , Corpo Clínico Hospitalar/psicologia , Corpo Clínico Hospitalar/normas , Satisfação Pessoal , Inquéritos e Questionários , Reino Unido
10.
Phys Rev Lett ; 115(25): 257402, 2015 Dec 18.
Artigo em Inglês | MEDLINE | ID: mdl-26722943

RESUMO

We used low-energy, momentum-resolved inelastic electron scattering to study surface collective modes of the three-dimensional topological insulators Bi_{2}Se_{3} and Bi_{0.5}Sb_{1.5}Te_{3-x}Se_{x}. Our goal was to identify the "spin plasmon" predicted by Raghu and co-workers [Phys. Rev. Lett. 104, 116401 (2010)]. Instead, we found that the primary collective mode is a surface plasmon arising from the bulk, free carriers in these materials. This excitation dominates the spectral weight in the bosonic function of the surface χ^{"}(q,ω) at THz energy scales, and is the most likely origin of a quasiparticle dispersion kink observed in previous photoemission experiments. Our study suggests that the spin plasmon may mix with this other surface mode, calling for a more nuanced understanding of optical experiments in which the spin plasmon is reported to play a role.

11.
J Tissue Viability ; 20 Suppl 1: S1-18, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22119531

RESUMO

AIM: Negative Pressure Wound Therapy (NPWT) has become widely adopted over the last 15 years and over 1000 peer-reviewed publications are available describing its use. Despite this, there remains uncertainty regarding several aspects of usage. In order to respond to this gap a global expert panel was convened to develop evidence-based recommendations describing the use of NPWT. In this communication the results of the study of evidence in chronic wounds including pressure ulcers, diabetic foot ulcers (DFU), venous leg ulcers (VLU), and ischaemic lower limb wounds are reported. METHODS: Evidence-based recommendations were obtained by a systematic review of the literature, grading of evidence, drafting of the recommendations by a global expert panel followed by a formal consultative consensus development program in which 422 independent healthcare professionals were able to agree or disagree with the recommendations. The criteria for agreement were set at 80% agreement. Evidence and recommendations were graded according to the SIGN (Scottish Intercollegiate Guidelines Network) classification system. RESULTS: The primary treatment goal of NPWT in most chronic wounds is to achieve wound closure (either by secondary intention or preparing the wound for surgical closure). Secondary goals commonly include: to reduce wound dimensions, and to improve the quality of the wound bed. Thirteen evidence based recommendations were developed in total to address these treatment goals; 4 for pressure ulcers, 4 for DFU, 3 for ischaemic lower limb wounds and 2 for VLU. CONCLUSION: The present evidence base is strongest for the use of NPWT in non-ischaemic DFU and weakest in VLU. The development of evidence-based recommendations for NPWT with direct validation from a large group of practicing clinicians offers a broader basis for consensus than work by an expert panel alone.


Assuntos
Prática Clínica Baseada em Evidências/normas , Tratamento de Ferimentos com Pressão Negativa/normas , Úlcera Cutânea/fisiopatologia , Úlcera Cutânea/terapia , Cicatrização , Doença Crônica , Consenso , Humanos , Cooperação Internacional , Guias de Prática Clínica como Assunto
12.
J Plast Reconstr Aesthet Surg ; 64 Suppl: S1-16, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21868296

RESUMO

Negative pressure wound therapy (NPWT) is becoming a commonplace treatment in many clinical settings. New devices and dressings are being introduced. Despite widespread adoption, there remains uncertainty regarding several aspects of NPWT use. To respond to these gaps, a global expert panel was convened to develop evidence-based recommendations describing the use of NPWT. In a previous communication, we have reviewed the evidence base for the use of NPWT within trauma and reconstructive surgery. In this communication, we present results of the assessment of evidence relating to the different NPWT treatment variables: different wound fillers (principally foam and gauze); when to use a wound contact layer; different pressure settings; and the impact of NPWT on bacterial bioburden. Evidence-based recommendations were obtained by a systematic review of the literature, grading of evidence and drafting of the recommendations by a global expert panel. Evidence and recommendations were graded according to the Scottish Intercollegiate Guidelines Network (SIGN) classification system. In general, there is relatively weak evidence on which to base recommendations for any one NPWT treatment variable over another. Overall, 14 recommendations were developed: five for the choice of wound filler and wound contact layer, four for choice of pressure setting and five for use of NPWT in infected wounds. With respect to bioburden, evidence suggests that reduction of bacteria in wounds is not a major mode of action of NPWT.


Assuntos
Tratamento de Ferimentos com Pressão Negativa/métodos , Ferimentos e Lesões/terapia , Antibacterianos/administração & dosagem , Bandagens , Redução de Custos , Drenagem/instrumentação , Drenagem/métodos , Medicina Baseada em Evidências , Humanos , Isquemia/complicações , Tratamento de Ferimentos com Pressão Negativa/instrumentação , Dor/prevenção & controle , Poliuretanos , Infecções dos Tecidos Moles/microbiologia , Infecções dos Tecidos Moles/terapia , Retalhos Cirúrgicos , Infecção da Ferida Cirúrgica/microbiologia , Infecção da Ferida Cirúrgica/terapia , Cicatrização , Ferimentos e Lesões/economia
13.
Injury ; 42 Suppl 1: S1-12, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21316515

RESUMO

Negative pressure wound therapy (NPWT) has become widely adopted over the last 15 years and over 1000 peer reviewed publications are available describing its use. Despite this, there remains uncertainty regarding several aspects of usage. In order to respond to this gap a global expert panel was convened to develop evidence-based recommendations describing the use of NPWT. In this paper the results of the study of evidence in traumatic wounds (including soft tissue defects, open fractures and burns) and reconstructive procedures (including flaps and grafts) are reported. Evidence-based recommendations were obtained by a systematic review of the literature, grading of evidence, drafting of the recommendations by a global expert panel, followed by a formal consultative consensus development program in which 422 independent healthcare professionals were able to agree or disagree with the recommendations. The criteria for agreement were set at 80% approval. Evidence and recommendations were graded according to the SIGN (Scottish Intercollegiate Guidelines Network) classification system. Twelve recommendations were developed in total; 4 for soft tissue trauma and open fracture injuries, 1 for burn injuries, 3 for flaps and 4 for skin grafts. The present evidence base is strongest for the use of NPWT on skin grafts and weakest as a primary treatment for burns. In the consultative process, 11/12 of the proposed recommendations reached the 80% agreement threshold. The development of evidence-based recommendations for NPWT with direct validation from a large group of practicing clinicians offers a broader basis for consensus than work by an expert panel alone.


Assuntos
Tratamento de Ferimentos com Pressão Negativa/métodos , Procedimentos de Cirurgia Plástica , Guias de Prática Clínica como Assunto , Ferimentos e Lesões/terapia , Queimaduras/terapia , Síndromes Compartimentais/cirurgia , Consenso , Desbridamento , Medicina Baseada em Evidências , Sobrevivência de Enxerto , Humanos , Necrose , Transplante de Pele/métodos , Retalhos Cirúrgicos , Técnicas de Fechamento de Ferimentos , Cicatrização/fisiologia , Ferimentos e Lesões/patologia
15.
Eur J Vasc Endovasc Surg ; 33(1): 100-4, 2007 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-17027302

RESUMO

OBJECTIVES: Patients with aortic aneurysms have significant comorbidities which influence outcome. Our practice includes comprehensive assessment to identify comorbidities, allowing subsequent medical optimisation prior to aneurysm repair. The aim of this study was to assess this process and to identify any factors predictive of outcome. DESIGN: Prospective observational study. MATERIALS: Medical case notes of 200 patients referred with aortic pathology. METHODS: Data analysed included preoperative, perioperative and postoperative factors. Multiple logistic regression analysis was performed to identify predictors of outcome. RESULTS: Following assessment 17 patients (8.5%) were found to be unfit for intervention and 165 patients (82.5%) proceeded to aneurysm repair. In this group assessment uncovered previously undiagnosed cardiac, respiratory and renal comorbidity in 19%, 57% and 29% of patients respectively. Multiple logistic regression analysis indicated that optimisation by a renal physician reduced post-operative renal impairment (OR 0.12, 95% CI 0.03-0.45, P=0.002) while optimisation by a cardiologist reduced respiratory complications (OR 0.7, 95% CI 0.05-0.99, P=0.049). An abnormal echocardiogram was associated with pneumonia (OR 6.9, 95% CI 1.6-29, P=0.01) and death (OR 7.9, 95% CI 1.15-54, P=0.036). CONCLUSION: Pre-operative assessment identifies previously undiagnosed comorbidity in a significant proportion of patients. Subsequent medical optimisation may reduce post-operative morbidity and mortality.


Assuntos
Aneurisma Aórtico/mortalidade , Aneurisma Aórtico/cirurgia , Procedimentos Cirúrgicos Eletivos , Seleção de Pacientes , Cuidados Pré-Operatórios/normas , Procedimentos Cirúrgicos Vasculares , Idoso , Aneurisma Aórtico/epidemiologia , Aneurisma da Aorta Abdominal/mortalidade , Aneurisma da Aorta Abdominal/cirurgia , Aneurisma da Aorta Torácica/mortalidade , Aneurisma da Aorta Torácica/cirurgia , Doenças Cardiovasculares/epidemiologia , Comorbidade , Feminino , Humanos , Nefropatias/epidemiologia , Modelos Logísticos , Masculino , Razão de Chances , Valor Preditivo dos Testes , Estudos Prospectivos , Projetos de Pesquisa , Doenças Respiratórias/epidemiologia , Medição de Risco , Resultado do Tratamento
16.
Br J Surg ; 93(5): 577-81, 2006 May.
Artigo em Inglês | MEDLINE | ID: mdl-16607693

RESUMO

BACKGROUND: The aim of this prospective study was to establish the prevalence of thrombophilia and hyperhomocysteinaemia using a comprehensive screen in patients with peripheral vascular disease. METHODS: A total of 150 patients with peripheral vascular disease (with an ankle brachial pressure index of less than 0.8) underwent thrombophilia screening (protein C and protein S, antithrombin, lupus anticoagulant, activated protein C resistance and factor V Leiden and prothrombin mutations). Fasting homocysteine assays were also performed. RESULTS: A thrombophilia defect was found in 41 patients (27.3 per cent). The commonest was protein S deficiency, found in 17 patients (11.3 per cent). Others included factor V Leiden mutation, found in 10 (6.7 per cent) and protein C deficiency, found in six (4.0 per cent). Lupus anticoagulant and prothrombin mutation were both found in six (4.0 per cent). One patient had an antithrombin deficiency. Only the presence of critical ischaemia was associated with a positive thrombophilia screen on single variable analysis (P = 0.03). Hyperhomocysteinaemia was present in over a third of the study group (37.3 per cent): 45 defined as moderate and 11 as intermediate. CONCLUSION: A quarter of patients with peripheral vascular disease had evidence of thrombophilia, and a third had hyperhomocysteinaemia.


Assuntos
Hiper-Homocisteinemia/complicações , Doenças Vasculares Periféricas/complicações , Trombofilia/etiologia , Idoso , Inibidores dos Fatores de Coagulação Sanguínea/sangue , Feminino , Humanos , Hiper-Homocisteinemia/epidemiologia , Masculino , Doenças Vasculares Periféricas/sangue , Doenças Vasculares Periféricas/epidemiologia , Prevalência , Estudos Prospectivos , Trombofilia/sangue , Trombofilia/epidemiologia
17.
Eur J Vasc Endovasc Surg ; 28(2): 124-31, 2004 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-15234691

RESUMO

This paper reviews the available data on the prevalence of thrombophilia defects in patients with peripheral vascular disease (PVD) and attempts to delineate the risk of failure of vascular intervention in these patients. The prevalence of thrombophilia in stable claudicants is 25% and increases to 40% in those requiring revascularisation, compared to only 11% in the control group. The overall prevalence of thrombophilia defects in patients with premature atherosclerosis appears to be between 15 and 30%. The prevalence in the typical cohort of patients with PVD appears to be similar. All these studies have recruited patients with symptoms significant enough to warrant intervention. The overall prevalence of thrombophilia calculated from these trials, therefore, may not be truly indicative of the general vascular population who may not even present primary or secondary healthcare. The risk of thrombotic occlusion following arterial revascularisation in patients with an identified thrombophilia defect appears to be almost three times that of patients with no evidence of a thrombophilia defect. The best management of these patients has not been determined and needs to be evaluated by prospective randomized trials.


Assuntos
Doenças Vasculares Periféricas/epidemiologia , Trombofilia/epidemiologia , Adulto , Aneurisma/epidemiologia , Síndrome Antifosfolipídica/epidemiologia , Arteriopatias Oclusivas/epidemiologia , Implante de Prótese Vascular , Doenças das Artérias Carótidas/epidemiologia , Humanos , Doenças Vasculares Periféricas/cirurgia , Prevalência , Deficiência de Proteína C/epidemiologia , Protrombina/genética
19.
Blood Coagul Fibrinolysis ; 12(7): 555-61, 2001 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11685044

RESUMO

The thromboelastograph (TEG), a measure of global haemostasis, is routinely used during cardiac and hepatic surgery to optimize blood product selection and usage. It has recently been suggested that it may also be a useful tool to screen patients with hypercoagulable states. Limited published data on performance characteristics has led to speculation regarding its consistency and, therefore, validity of the results. This study was designed to assess the effect of stability of blood samples prior to testing, repeated sampling, intra- and inter-assay variability using the native, celite, tissue factor (TF) and Reopro-modified TEG. Analysis of native and celite samples after storage over 90 min showed a period of instability up to 30 min. Thereafter, all parameters between 30 and 90 min were stable [P = not significant (NS)]. When the same sample was repeatedly assayed, both native and celite TEG parameters showed a significant change towards hypercoagulability (P < 0.01), whereas the TF and Reopro-modified TEG showed no change. Intra- and inter-assay variability on samples tested after 30 min showed excellent reproducibility for all parameters (P = NS). The data suggest that the TEG is a useful tool in haemostasis but requires a formal standard operating procedure to be adopted that takes into account the initial period of sample instability.


Assuntos
Tromboelastografia/normas , Coleta de Amostras Sanguíneas , Estabilidade de Medicamentos , Hemostasia , Humanos , Controle de Qualidade , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Tromboelastografia/instrumentação
20.
Magn Reson Med ; 46(2): 365-73, 2001 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-11477641

RESUMO

Protocols for contrast-enhanced magnetic resonance angiography (CE-MRA) of the iliac arteries were optimized by computer simulations based on an impulse response function (IRF) of contrast agent (CA) concentration as a function of time obtained for 20 patients. Protocols with sequential, centric, and elliptical k-space coverage, different repetition rates (5 and 10 ms), and CA doses (0.1, 0.2, and 0.3 mmol/kg b.w.) were compared in terms of signal-to-noise ratio (SNR), distortion of vessel profiles, and sensitivity to timing errors. IRF-based simulations successfully characterized CA recirculation. Slow-rate CA infusions were found to achieve relatively high enhancement. In terms of SNR, there is no advantage in increasing the repetition rate. Distortion of vessel profiles is more likely in elliptic and centric k-space coverage. Protocols based on sequential k-space coverage and relatively long CA infusions proved to be particularly suited to large-FOV iliac examinations as they are relatively insensitive to timing errors.


Assuntos
Arteriopatias Oclusivas/diagnóstico , Meios de Contraste/administração & dosagem , Gadolínio DTPA/administração & dosagem , Artéria Ilíaca , Angiografia por Ressonância Magnética/métodos , Adulto , Idoso , Simulação por Computador , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
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