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1.
J Appl Microbiol ; 130(1): 278-291, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32650353

RESUMO

AIMS: Accurate identification of dermatophytes is essential for implementing appropriate antifungal treatment and epidemiological analysis. However, the limitations of conventional diagnostics are a frequently discussed topic, and new diagnostic techniques are constantly expanding. In this study, we assess the suitability of conventional diagnostic techniques in comparison to the real-time PCR assay and MALDI-TOF MS in detection and identification of dermatophytes. METHODS AND RESULTS: Strains included in this study were obtained from human and animals with symptomatic, and asymptomatic infection. A direct examination revealed that 31·7 and 60·9% of samples from symptomatic patients, and 25·7 and 60% from asymptomatic animals were positive, as shown by light and fluorescence microscopy respectively. In turn, dermatophytes were isolated from 90·2 and 71·4% of these samples. The pan-dermatophyte primers in real-time PCR assay facilitated detection in 85·3 and 82·9% of the symptomatic and asymptomatic dermatophytoses respectively. Additionally, species-specific PCR assays were positive in 70·7 and 37·1% of these samples. The MALDI-TOF MS analysis yielded positive results consistent with conventional techniques in 97·2 and 72% of symptomatic and asymptomatic infections respectively. CONCLUSIONS: Our study revealed that there is no universal diagnostic method that would be ideal in each of the cases considered. Nonetheless, conventional techniques are still the most effective and reliable tools for mycological diagnostics. SIGNIFICANCE AND IMPACT OF THE STUDY: Dermatologists and veterinarians have difficulties in making a diagnosis of dermatophytoses based only on observed symptoms of fungal infections, as they mimic symptoms of other dermatoses. In this context, a comparative analysis of the results of diagnostics performed using conventional methods and new technologies are crucial for implementing these pioneer methods into routine laboratory practice.


Assuntos
Arthrodermataceae/classificação , Arthrodermataceae/isolamento & purificação , Técnicas de Tipagem Micológica/métodos , Animais , Arthrodermataceae/química , Arthrodermataceae/genética , Dermatomicoses/microbiologia , Testes Diagnósticos de Rotina , Humanos , Reação em Cadeia da Polimerase em Tempo Real , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz
3.
Eur Rev Med Pharmacol Sci ; 23(9): 3857-3866, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-31115013

RESUMO

OBJECTIVE: Lung cancer (LC) is diagnosed mostly in advanced, non-operable stage, with poor prognosis. The analysis of microRNAs may be a useful tool for early and non-invasive detection of cancer. Dicer and Drosha are enzymes with an essential role for microRNA biogenesis. The aim of our study was to analyze the expression of miRNA-27a-3p, miRNA-31, miRNA-182, miRNA-195 with the ability to reciprocal regulation of Dicer and Drosha expression in lung cancer patients. PATIENTS AND METHODS: The relative expression of microRNAs was detected by qPCR in plasma of 160 LC patients. The U-Mann Whitney test was used to compare the relative expression between particular groups of lung cancer patients and healthy individuals. The diagnostic value of microRNAs examination was analyzed using a receiver operating curve. RESULTS: We demonstrated that the plasma levels of miRNA-27, miRNA-31 and miRNA-182 were significantly higher and miRNA-195 significantly lower in the whole group of LC patients and in patients with early stages of NSCLC, in comparison with healthy donors. ROC analysis showed that four studied microRNAs have a potential diagnostic value for early stages of NSCLC with AUC=0.95 for miRNA-27a (94% sensitivity and 81% specificity, p=0.0001), 0.71 for miRNA-31 (73% sensitivity and 61% specificity, p=0.001) 0.77 for miRNA-182 (70% sensitivity and 79% specificity, p=0.0001) and 0.82 for miRNA-195 (74% sensitivity and 80% specificity, p=0.0001). CONCLUSIONS: We have proved that the expression of miRNA-27a-3p, miRNA-31, miRNA-182, and miRNA-195 in patients with LC is different from the expression of these molecules in healthy people. The examination of these microRNAs in plasma could be used in non-invasive lung cancer diagnosis.


Assuntos
RNA Helicases DEAD-box/genética , Neoplasias Pulmonares/diagnóstico , MicroRNAs/metabolismo , Ribonuclease III/genética , Idoso , Área Sob a Curva , RNA Helicases DEAD-box/metabolismo , Detecção Precoce de Câncer , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patologia , Masculino , MicroRNAs/genética , Pessoa de Meia-Idade , Curva ROC , Ribonuclease III/metabolismo , Sensibilidade e Especificidade
4.
Clin Neuroradiol ; 29(1): 101-108, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29150710

RESUMO

BACKGROUND: In the diagnosis of brain death (BD), computed tomography angiography (CTA) results in some cases show intracranial filling, leading to diagnostic confusion. Because cerebral circulatory arrest commences at the capillary level, we hypothesized that computed tomography perfusion (CTP) would be a more sensitive approach than CTA; therefore, the aim of the study was to compare the sensitivities of CTP and CTA in the diagnosis of BD. MATERIAL AND METHODS: Whole brain CTP was performed in patients in the intensive care unit diagnosed with BD and CTA was derived from CTP datasets. Cerebral blood flow (CBF) and volume (CBV) were calculated in all brain regions. The CTP findings were interpreted as being consistent with a diagnosis of BD (positive) when CBF and CBV in all regions of interest (ROIs) were below 10 ml/100 g/min and 1.0 ml/100 g, respectively. The CTA findings were interpreted using a 4-point grading system. RESULTS: A total of 50 patients were included in the study. The CTP results revealed CBF from 0.00 to 9.98 ml/100 g/min (mean, 1.98 ± 1.68 ml/100 g/min) and CBV from 0.00 to 0.99 ml/100 g (mean, 0.14 ± 0.12 ml/100 g) and were thus interpreted as positive in all 50 patients. In contrast, the CTA results suggested 7 negative cases, providing a sensitivity of 86%. The difference between the CTP and CTA sensitivity results for the diagnosis of BD was statistically significant (p = 0.006). CONCLUSION: Whole brain CTP may potentially be a feasible and highly sensitive test for diagnosing BD: therefore, performing CTP in combination with CTA in cases when CTA results are negative for BD could increase the sensitivity of CTA.


Assuntos
Morte Encefálica/diagnóstico por imagem , Tomografia Computadorizada por Raios X , Adolescente , Adulto , Idoso , Volume Sanguíneo , Encéfalo/irrigação sanguínea , Encéfalo/diagnóstico por imagem , Angiografia Cerebral/métodos , Circulação Cerebrovascular , Angiografia por Tomografia Computadorizada , Reações Falso-Negativas , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Sensibilidade e Especificidade , Adulto Jovem
5.
Clin. transl. oncol. (Print) ; 19(12): 1447-1453, dic. 2017. tab
Artigo em Inglês | IBECS | ID: ibc-168906

RESUMO

Purpose. RT-PCR technique has showed a promising value as pre-screening method for detection of mRNA containing abnormal ALK sequences, but its sensitivity and specificity is still discussable. Previously, we determined the incidence of ALK rearrangement in CNS metastases of NSCLC using IHC and FISH methods. Materials. We evaluated ALK gene rearrangement using two-step RT-PCR method with EML4-ALK Fusion Gene Detection Kit (Entrogen, USA). The studied group included 145 patients (45 females, 100 males) with CNS metastases of NSCLC and was heterogeneous in terms of histology and smoking status. Results. 21% of CNS metastases of NSCLC (30/145) showed presence of mRNA containing abnormal ALK sequences. FISH and IHC tests confirmed the presence of ALK gene rearrangement and expression of ALK abnormal protein in seven patients with positive result of RT-PCR analysis (4.8% of all patients, 20% of RT-PCR positive patients). RT-PCR method compared to FISH analysis achieved 100% of sensitivity and only 82.7% of specificity. IHC method compared to FISH method indicated 100% of sensitivity and 97.8% of specificity. In comparison to IHC, RT-PCR showed identical sensitivity with high number of false positive results. Conclusion. Utility of RT-PCR technique in screening of ALK abnormalities and in qualification patients for molecularly targeted therapies needs further validation (AU)


No disponible


Assuntos
Humanos , Carcinoma Pulmonar de Células não Pequenas/genética , Neoplasias Pulmonares/genética , Neoplasias do Sistema Nervoso Central/genética , Neoplasias do Sistema Nervoso Central/secundário , Reação em Cadeia da Polimerase em Tempo Real/métodos , Imuno-Histoquímica/métodos , Rearranjo Gênico/genética , Linfoma Anaplásico de Células Grandes/genética
6.
Case Rep Hematol ; 2017: 3725089, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28808591

RESUMO

We present the case where immune thrombocytopenia (ITP) and essential thrombocythemia (ET) sequentially appeared in the space of twenty-one years of follow-up. Impaired platelet production is present in both diseases, but clinical presentation and treatment are different. On the basis of this case history a possible role of autoimmunity as a predisposing factor to myeloproliferation has been discussed.

7.
Clin Transl Oncol ; 19(12): 1447-1453, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28534101

RESUMO

PURPOSE: RT-PCR technique has showed a promising value as pre-screening method for detection of mRNA containing abnormal ALK sequences, but its sensitivity and specificity is still discussable. Previously, we determined the incidence of ALK rearrangement in CNS metastases of NSCLC using IHC and FISH methods. MATERIALS: We evaluated ALK gene rearrangement using two-step RT-PCR method with EML4-ALK Fusion Gene Detection Kit (Entrogen, USA). The studied group included 145 patients (45 females, 100 males) with CNS metastases of NSCLC and was heterogeneous in terms of histology and smoking status. RESULTS: 21% of CNS metastases of NSCLC (30/145) showed presence of mRNA containing abnormal ALK sequences. FISH and IHC tests confirmed the presence of ALK gene rearrangement and expression of ALK abnormal protein in seven patients with positive result of RT-PCR analysis (4.8% of all patients, 20% of RT-PCR positive patients). RT-PCR method compared to FISH analysis achieved 100% of sensitivity and only 82.7% of specificity. IHC method compared to FISH method indicated 100% of sensitivity and 97.8% of specificity. In comparison to IHC, RT-PCR showed identical sensitivity with high number of false positive results. CONCLUSION: Utility of RT-PCR technique in screening of ALK abnormalities and in qualification patients for molecularly targeted therapies needs further validation.


Assuntos
Biomarcadores Tumorais/genética , Carcinoma Pulmonar de Células não Pequenas/patologia , Neoplasias do Sistema Nervoso Central/secundário , Rearranjo Gênico , Receptores Proteína Tirosina Quinases/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , Adenocarcinoma/genética , Adenocarcinoma/patologia , Adulto , Idoso , Quinase do Linfoma Anaplásico , Carcinoma de Células Grandes/genética , Carcinoma de Células Grandes/patologia , Carcinoma Pulmonar de Células não Pequenas/genética , Carcinoma de Células Escamosas/genética , Carcinoma de Células Escamosas/patologia , Neoplasias do Sistema Nervoso Central/genética , Feminino , Seguimentos , Humanos , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patologia , Masculino , Pessoa de Meia-Idade , Prognóstico
8.
Sci Rep ; 7: 41877, 2017 02 02.
Artigo em Inglês | MEDLINE | ID: mdl-28150798

RESUMO

The Fermi level position in (Ga,Mn)N has been determined from the period-analysis of GaN-related Franz-Keldysh oscillation obtained by contactless electroreflectance in a series of carefully prepared by molecular beam epitaxy GaN/Ga1-xMnxN/GaN(template) bilayers of various Mn concentration x. It is shown that the Fermi level in (Ga,Mn)N is strongly pinned in the middle of the band gap and the thickness of the depletion layer is negligibly small. For x > 0.1% the Fermi level is located about 1.25-1.55 eV above the valence band, that is very close to, but visibly below the Mn-related Mn2+/Mn3+ impurity band. The accumulated data allows us to estimate the Mn-related band offsets at the (Ga,Mn)N/GaN interface. It is found that most of the band gap change in (Ga,Mn)N takes place in the valence band on the absolute scale and amounts to -0.028 ± 0.008 eV/% Mn. The strong Fermi level pinning in the middle of the band gap, no carrier conductivity within the Mn-related impurity band, and a good homogeneity enable a novel functionality of (Ga,Mn)N as a semi-insulating buffer layers for applications in GaN-based heterostuctures.

9.
Nanoscale ; 9(6): 2129-2137, 2017 Feb 09.
Artigo em Inglês | MEDLINE | ID: mdl-28120988

RESUMO

(Ga,Mn)As having a wurtzite crystal structure was coherently grown by molecular beam epitaxy on the {1100} side facets of wurtzite (Ga,In)As nanowires and further encapsulated by (Ga,Al)As and low temperature GaAs. For the first time, a truly long-range ferromagnetic magnetic order is observed in non-planar (Ga,Mn)As, which is attributed to a more effective hole confinement in the shell containing Mn by the proper selection/choice of both the core and outer shell materials.

10.
Nat Commun ; 7: 13232, 2016 10 26.
Artigo em Inglês | MEDLINE | ID: mdl-27782126

RESUMO

The significant inversion symmetry breaking specific to wurtzite semiconductors, and the associated spontaneous electrical polarization, lead to outstanding features such as high density of carriers at the GaN/(Al,Ga)N interface-exploited in high-power/high-frequency electronics-and piezoelectric capabilities serving for nanodrives, sensors and energy harvesting devices. Here we show that the multifunctionality of nitride semiconductors encompasses also a magnetoelectric effect allowing to control the magnetization by an electric field. We first demonstrate that doping of GaN by Mn results in a semi-insulating material apt to sustain electric fields as high as 5 MV cm-1. Having such a material we find experimentally that the inverse piezoelectric effect controls the magnitude of the single-ion magnetic anisotropy specific to Mn3+ ions in GaN. The corresponding changes in the magnetization can be quantitatively described by a theory developed here.

11.
Transplant Proc ; 48(7): 2471-2472, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27742325

RESUMO

Polish brain death (BD) criteria established in 2007 are currently under review and therefore all reports about any problems noticed during diagnostic attempts are being carefully analyzed. According to information from intensive care units, patients with poor baseline lung function often do not tolerate ventilator disconnection during the apnea test (AT) despite previous preoxygenation and catheter O2 insufflation. Abortion of AT because of decrease of saturation as measured by pulse oximetry is quite common. To solve this problem, implementation of continuous positive airway pressure (CPAP) with 100% O2 was proposed as an option for newly developed guidelines. Before implementation of CPAP for AT we verified it by means of a multicenter trial in a group of 51 patients with various lung function. In one case, in a patient with baseline PaO2 of 83 mm Hg during ventilation with 100% oxygen, we used the CPAP option for AT and successfully completed BD diagnosis. In conclusion, ventilator-delivered CPAP for AT may be a valuable alternative to the classic oxygen insufflation method for the BD diagnosis procedure in patients with severe lung injury and poor baseline oxygenation.


Assuntos
Apneia/diagnóstico , Morte Encefálica/diagnóstico , Pressão Positiva Contínua nas Vias Aéreas/métodos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
12.
Clin. transl. oncol. (Print) ; 18(10): 1039-1043, oct. 2016. tab, graf
Artigo em Inglês | IBECS | ID: ibc-155968

RESUMO

Background: The mitogen-activated protein kinases 1 and 2 (MEK1, MEK2) are fundamental partners in the RAS-RAF-MEK-ERK pathway that is involved in regulation of cell proliferation, differentiation and survival. Downregulation of the MEK cascades has been implicated in acquiring of the malignant phenotype in various cancers. Somatic mutations in MEK1 gene (substitutions K57N, Q56P, D67N) were described in < 1 % of non-small cell lung cancer (NSCLC) and they were more commonly reported in adenocarcinoma patients with current or former smoking status. Materials and methods: In the following study, we assessed the MEK1 gene mutations in 145 FFPE tissue samples from central nervous system (CNS) metastases of NSCLC using HRM-PCR and ASP-qPCR techniques. The studied group was heterogeneous in terms of histopathology and smoking status. The prevalence of the MEK1 gene mutation was correlated with the occurrence of mutations in KRAS, EGFR, DDR2, PIK3CA, NRAS, HER2, AKT1 and PTEN genes. Results: Using HRM and ASP-qPCR methods we identified one (0.7 %; 1/145) MEK1 substitution (Q56P) in CNS metastases of NSCLC. The mutation was identified in a single, 50-year-old, current smoking men with adenocarcinoma (1.25 %; 1/80 of all adenocarcinomas). Conclusions: According to the current knowledge, the incidence of MEK1 gene mutation in CNS metastatic lesion of NSCLC is the first such report worldwide. The analysis of gene profile in cancer patients may extend the scope of molecularly targeted therapies used both in patients with primary and metastatic tumors of NSCLC (AU)


No disponible


Assuntos
Humanos , Carcinoma Pulmonar de Células não Pequenas/patologia , Neoplasias Pulmonares/patologia , Neoplasias do Sistema Nervoso Central/patologia , Metástase Neoplásica/patologia , Proteína Quinase 1 Ativada por Mitógeno/análise
13.
Transplant Proc ; 48(1): 282-4, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26915886

RESUMO

A suspicion of brain death (BD) is the 1st step in the process of BD certification. Owing to its utmost importance, the process must yield an unequivocal answer so that the committee for the determination of BD has no doubts. We present a case of a patient with suspected BD, with a diagnosis of no intracranial flow in 4-vessel digital-subtraction angiography, who developed some reflexes just before clinical examination for BD assessment. The source of clinical findings was determined to be an extracranial blood supply, which enabled the preservation of trace lower brain stem functioning.


Assuntos
Morte Encefálica/diagnóstico , Infarto Encefálico/fisiopatologia , Circulação Cerebrovascular , Idoso , Angiografia Digital/métodos , Encéfalo/irrigação sanguínea , Morte Encefálica/fisiopatologia , Infarto Encefálico/complicações , Tronco Encefálico/fisiopatologia , Angiografia Cerebral/métodos , Humanos , Masculino , Preservação Biológica , Respiração
14.
Clin Transl Oncol ; 18(10): 1039-43, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26860843

RESUMO

BACKGROUND: The mitogen-activated protein kinases 1 and 2 (MEK1, MEK2) are fundamental partners in the RAS-RAF-MEK-ERK pathway that is involved in regulation of cell proliferation, differentiation and survival. Downregulation of the MEK cascades has been implicated in acquiring of the malignant phenotype in various cancers. Somatic mutations in MEK1 gene (substitutions K57N, Q56P, D67N) were described in <1 % of non-small cell lung cancer (NSCLC) and they were more commonly reported in adenocarcinoma patients with current or former smoking status. MATERIALS AND METHODS: In the following study, we assessed the MEK1 gene mutations in 145 FFPE tissue samples from central nervous system (CNS) metastases of NSCLC using HRM-PCR and ASP-qPCR techniques. The studied group was heterogeneous in terms of histopathology and smoking status. The prevalence of the MEK1 gene mutation was correlated with the occurrence of mutations in KRAS, EGFR, DDR2, PIK3CA, NRAS, HER2, AKT1 and PTEN genes. RESULTS: Using HRM and ASP-qPCR methods we identified one (0.7 %; 1/145) MEK1 substitution (Q56P) in CNS metastases of NSCLC. The mutation was identified in a single, 50-year-old, current smoking men with adenocarcinoma (1.25 %; 1/80 of all adenocarcinomas). CONCLUSIONS: According to the current knowledge, the incidence of MEK1 gene mutation in CNS metastatic lesion of NSCLC is the first such report worldwide. The analysis of gene profile in cancer patients may extend the scope of molecularly targeted therapies used both in patients with primary and metastatic tumors of NSCLC.


Assuntos
Biomarcadores Tumorais/genética , Carcinoma Pulmonar de Células não Pequenas/genética , Neoplasias do Sistema Nervoso Central/genética , Análise Mutacional de DNA/métodos , Neoplasias Pulmonares/genética , MAP Quinase Quinase 1/genética , Mutação/genética , Adenocarcinoma/genética , Adenocarcinoma/patologia , Carcinoma de Células Grandes/genética , Carcinoma de Células Grandes/patologia , Carcinoma Pulmonar de Células não Pequenas/patologia , Carcinoma de Células Escamosas/genética , Carcinoma de Células Escamosas/patologia , Neoplasias do Sistema Nervoso Central/secundário , Detecção Precoce de Câncer/métodos , Feminino , Seguimentos , Humanos , Neoplasias Pulmonares/patologia , Metástase Linfática , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Prognóstico , Reação em Cadeia da Polimerase em Tempo Real
15.
Health Educ Res ; 30(5): 773-85, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26338985

RESUMO

African Americans have an increased risk of cardiovascular disease partly due to low fruit and vegetable consumption. This article reports the results of an intervention to provide nutrition education and access to fruits and vegetables through community gardens to change dietary behaviors among African Americans in rural Missouri. Cross-sectional surveys evaluated the intervention effect on blood pressure, body mass index (BMI), and perceived fruit and vegetable consumption in this quasi-experimental study with a comparison group. Hypertension (OR = 0.52, 95% CI: 0.38-0.71) and BMI (OR = 0.73, 95% CI: 0.52-1.02) were lower in the intervention county at mid-intervention. Participation in nutrition education (OR = 2.67, 95% CI: 1.63-4.40) and access to fruits and vegetables from a community garden (OR = 1.95, 95% CI: 1.20-3.15) were independently associated with perceived fruit and vegetable consumption. The strongest effect on perceived fruit and vegetable consumption occurred with high participation in nutrition education and access to community gardens (OR = 2.18, 95% CI: 1.24-3.81). Those with access but without education had a reduced likelihood of consuming recommended servings of fruits and vegetables (OR = 0.57, 95% CI: 0.34-0.95). Education plus access interventions may be best at increasing consumption of fruits and vegetables in a rural African American population.


Assuntos
Negro ou Afro-Americano , Doenças Cardiovasculares/prevenção & controle , Dieta/estatística & dados numéricos , Frutas , Educação em Saúde/métodos , Verduras , Adulto , Doenças Cardiovasculares/epidemiologia , Estudos Transversais , Demografia , Feminino , Humanos , Masculino , Missouri/epidemiologia , População Rural
16.
J Phys Condens Matter ; 25(37): 376001, 2013 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-23962975

RESUMO

With the aim of studying the interface magnetism, the onset of ferromagnetism and the onset of the transition to the superconducting state a series of [La0.7Sr0.3MnO3(n u.c.)/YBa2Cu3O7(2 u.c.)]20 (LSMO/YBCO) superlattices with nominally varying layer thickness of the LSMO from one to four unit cells (u.c.) was prepared and characterized by x-ray diffraction, electronic transport, magnetization and ferromagnetic resonance measurements. Spontaneous magnetization was observed for a superlattice with four u.c. LSMO layer thickness in a multilayer structure. Superlattices with 3 u.c. of LSMO and lower layer thicknesses did not show a signature of ferromagnetism. The onset of superconductivity was observed for superlattices with one and two LSMO layer u.c. thickness.


Assuntos
Compostos de Bário/química , Cobre/química , Condutividade Elétrica , Lantânio/química , Magnetismo , Imãs , Compostos de Manganês/química , Estrôncio/química , Ítrio/química , Espectroscopia de Ressonância de Spin Eletrônica , Teste de Materiais , Difração de Raios X
17.
Neuroradiology ; 55(9): 1061-9, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23728070

RESUMO

INTRODUCTION: Stasis filling, defined as delayed, weak, and persistent opacification of proximal segments of the cerebral arteries, is frequently found in brain dead patients. This phenomenon causes a major problem in the development of reliable computed tomographic angiography (CTA) protocol in the diagnosis of brain death (BD). The aim of our study was to characterize stasis filling in the diagnosis of BD. To achieve this, we performed a dynamic evaluation of contrast enhancement of the cerebral and extracranial arteries in patients with BD and controls. METHODS: Study population included 30 BD patients, who showed stasis filling in computed tomographic perfusion (CTP) series. Thirty patients, after clipping of an intracranial aneurysm, constituted the control group. The study protocol consisted of CTA, CTP, and angiography. Time-density curves (TDCs) of cerebral and extracranial arteries were generated using 40-s series of CTP. RESULTS: Cerebral TDCs in BD patients represented flat curves in contrast to TDCs in controls, which formed steep and narrow Gaussian curves. We found longer time to peak enhancement in BD patients than in controls (32 vs. 21 s; p < 0.0001). In BD patients, peak enhancement in the cerebral arteries occurred with a median delay of 14.5 s to peak in extracranial arteries, while no delay was noted in controls (p < 0.0001). Cerebral arteries in BD patients showed lower peak enhancement than controls (34.5 vs. 81.5 HU; p < 0.0001). In all BD patients, CTP revealed zero values of cerebral blood flow and volume. Angiography showed stasis filling in 14 (46.7 %) and non-filling in 16 (53.3 %) cases. CONCLUSION: A confrontation of stasis filling with CTP results showed that stasis filling is not consistent with preserved cerebral perfusion, thus does not preclude diagnosis of BD.


Assuntos
Morte Encefálica , Angiografia Cerebral/métodos , Artérias Cerebrais/diagnóstico por imagem , Transtornos Cerebrovasculares/complicações , Transtornos Cerebrovasculares/diagnóstico por imagem , Tomografia Computadorizada por Raios X/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Adulto Jovem
18.
Transplant Proc ; 42(10): 3941-6, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21168593

RESUMO

INTRODUCTION: According to Polish brain death (BD) criteria, instrumental confirmatory tests should be used in certain clinical situations, particularly any case for which clinical examinations seem inadequate. Electrophysiological tests are often unavailable. Therefore, cerebral perfusion testing is the method of choice with four-vessel digital subtraction angiography (DSA), the gold standard. Unfortunately, DSA is an expensive and invasive examination that requires an experienced neuroradiologist and the availability of an angiography suite. Recently, multirow computed tomographic devices became available, even in smaller hospitals in Poland. Despite this fact, computed tomographic angiography (CTA) and computed tomographic perfusion (CTP) are not accepted in BD diagnosis protocols in Poland because of limited experience and a lack of widely accepted criteria. In this situation, we started a multicenter trial to determine the accuracy of CTA and CTP to confirm BD. METHODS: We examined 24 patients who fulfilled standard clinical BD criteria. We recognized the absence of brain perfusion in CTA examination following the criteria proposed by the French Society of Neuroradiology, namely, the absence of opacification of M4 middle cerebral artery segments (M4-MCA) and of deep cerebral veins. RESULTS: In all of our patients, CTA showed absence of opacification of M4 segments and of deep cerebral veins. In addition, three patients had CTA showing weak opacification of A2 segments of the anterior cerebral artery (A2-ACA) and M2 or M3-MCA. Opacification of the basilar artery or of the posterior cerebral arteries was not noted in any case. In all patients, CTP revealed zero values of regional cerebral blood volume and regional cerebral blood flow. Conventional angiography confirmed cerebral circulatory arrest in all 24 cases. CONCLUSION: CTA and CTP seem to be promising radiological examinations for the diagnosis of BD. They may be noninvasive alternatives to conventional cerebral angiography, and to the other instrumental confirmatory tests, that are unavailable or inadequate.


Assuntos
Angiografia , Morte Encefálica/diagnóstico , Tomografia Computadorizada por Raios X , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Polônia , Fluxo Sanguíneo Regional
19.
Phys Rev Lett ; 105(21): 217601, 2010 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-21231354

RESUMO

We use SrTiO3/Si as a model system to elucidate the effect of the interface on ferroelectric behavior in epitaxial oxide films on silicon. Using both first-principles computations and synchrotron x-ray diffraction measurements, we show that structurally imposed boundary conditions at the interface stabilize a fixed (pinned) polarization in the film but inhibit ferroelectric switching. We demonstrate that the interface chemistry responsible for these phenomena is general to epitaxial silicon-oxide interfaces, impacting on the design of silicon-based functional oxide devices.

20.
Phys Rev Lett ; 101(13): 135502, 2008 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-18851460

RESUMO

The control on the distribution of magnetic ions into a semiconducting host is crucial for the functionality of magnetically doped semiconductors. Through a structural analysis at the nanoscale, we give experimental evidence that the aggregation of Fe ions in (Ga,Fe)N and consequently the magnetic response of the material are affected by the growth rate and doping with shallow impurities.

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