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1.
Phys Rev Lett ; 132(15): 152503, 2024 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-38682970

RESUMO

The first complete measurement of the ß-decay strength distribution of _{17}^{45}Cl_{28} was performed at the Facility for Rare Isotope Beams (FRIB) with the FRIB Decay Station Initiator during the second FRIB experiment. The measurement involved the detection of neutrons and γ rays in two focal planes of the FRIB Decay Station Initiator in a single experiment for the first time. This enabled an analytical consistency in extracting the ß-decay strength distribution over the large range of excitation energies, including neutron unbound states. We observe a rapid increase in the ß-decay strength distribution above the neutron separation energy in _{18}^{45}Ar_{27}. This was interpreted to be caused by the transitioning of neutrons into protons excited across the Z=20 shell gap. The SDPF-MU interaction with reduced shell gap best reproduced the data. The measurement demonstrates a new approach that is sensitive to the proton shell gap in neutron rich nuclei according to SDPF-MU calculations.

2.
Phys Rev Lett ; 131(5): 052503, 2023 Aug 04.
Artigo em Inglês | MEDLINE | ID: mdl-37595241

RESUMO

Potassium-40 is a widespread, naturally occurring isotope whose radioactivity impacts subatomic rare-event searches, nuclear structure theory, and estimated geological ages. A predicted electron-capture decay directly to the ground state of argon-40 has never been observed. The KDK (potassium decay) collaboration reports strong evidence of this rare decay mode. A blinded analysis reveals a nonzero ratio of intensities of ground-state electron-captures (I_{EC^{0}}) over excited-state ones (I_{EC^{*}}) of I_{EC^{0}}/I_{EC^{*}}=0.0095±[over stat]0.0022±[over sys]0.0010 (68% C.L.), with the null hypothesis rejected at 4σ. In terms of branching ratio, this signal yields I_{EC^{0}}=0.098%±[over stat]0.023%±[over sys]0.010%, roughly half of the commonly used prediction, with consequences for various fields [27L. Hariasz et al., companion paper, Phys. Rev. C 108, 014327 (2023)PRVCAN2469-998510.1103/PhysRevC.108.014327].

3.
Phys Rev Lett ; 131(2): 022501, 2023 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-37505957

RESUMO

The ß decays from both the ground state and a long-lived isomer of ^{133}In were studied at the ISOLDE Decay Station (IDS). With a hybrid detection system sensitive to ß, γ, and neutron spectroscopy, the comparative partial half-lives (logft) have been measured for all their dominant ß-decay channels for the first time, including a low-energy Gamow-Teller transition and several first-forbidden (FF) transitions. Uniquely for such a heavy neutron-rich nucleus, their ß decays selectively populate only a few isolated neutron unbound states in ^{133}Sn. Precise energy and branching-ratio measurements of those resonances allow us to benchmark ß-decay theories at an unprecedented level in this region of the nuclear chart. The results show good agreement with the newly developed large-scale shell model (LSSM) calculations. The experimental findings establish an archetype for the ß decay of neutron-rich nuclei southeast of ^{132}Sn and will serve as a guide for future theoretical development aiming to describe accurately the key ß decays in the rapid-neutron capture (r-) process.

4.
Phys Rev Lett ; 129(17): 172701, 2022 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-36332266

RESUMO

The ß-delayed one- and two-neutron emission probabilities (P_{1n} and P_{2n}) of 20 neutron-rich nuclei with N≥82 have been measured at the RIBF facility of the RIKEN Nishina Center. P_{1n} of ^{130,131}Ag, ^{133,134}Cd, ^{135,136}In, and ^{138,139}Sn were determined for the first time, and stringent upper limits were placed on P_{2n} for nearly all cases. ß-delayed two-neutron emission (ß2n) was unambiguously identified in ^{133}Cd and ^{135,136}In, and their P_{2n} were measured. Weak ß2n was also detected from ^{137,138}Sn. Our results highlight the effect of the N=82 and Z=50 shell closures on ß-delayed neutron emission probability and provide stringent benchmarks for newly developed macroscopic-microscopic and self-consistent global models with the inclusion of a statistical treatment of neutron and γ emission. The impact of our measurements on r-process nucleosynthesis was studied in a neutron star merger scenario. Our P_{1n} and P_{2n} have a direct impact on the odd-even staggering of the final abundance, improving the agreement between calculated and observed Solar System abundances. The odd isotope fraction of Ba in r-process-enhanced (r-II) stars is also better reproduced using our new data.

5.
J Physiol Pharmacol ; 71(6)2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33727431

RESUMO

Galectin-3 is ß-galactoside-binding lectin, used in cardiology as a biomarker of heart failure. Available research suggest galectin-3 may play a role in the development of preeclampsia. Seventy seven women were included in the study: 39 with preeclampsia and 38 with uncomplicated pregnancy. Patients underwent blood sample analysis (galectin-3, N-terminal pro-brain natriuretic peptide (NT-proBNP), soluble fms-like tyrosine kinase-1 (sFlt-1), placental growth factor (PlGF), cystatin C, creatinine) and echocardiographic examination. After delivery, placental tissue samples were obtained for immunohistochemistry evaluation. In patients with preeclampsia, serum galectin-3 levels (11.8 versus 9.5 ng/ml; p = 0.004) and galectin-3 expression in placental tissue (immunoreactive score (IRS) in extravillous trophoblasts: 9 versus 5; p = 0.002; in syncytiotrophoblasts: 6 versus 2, p < 0.001) were significantly higher than in the control group. Serum NT-proBNP and sFlt-1 levels, sFlt-1/PlGF ratio, serum creatinine and cystatin C levels were significantly higher, whereas serum PlGF levels and estimated glomerular filtration rate (eGFR) were significantly lower in preeclamptic patients than in uncomplicated pregnancy. On echocardiography, preeclamptic women had significantly greater thickness of interventricular septum (IVS) and left ventricle posterior wall (PW) and significantly worse left ventricle diastolic function (higher E/e' values). Serum galectin-3 level did not correlate with any other biochemical parameters, as well as the vast majority of echocardiographic parameters. Significant correlation between serum galectin-3 and its placental expression in syncytiotrophoblasts (STB) was revealed. Renal function parameters and NT-proBNP correlated with antiangiogenic state. This study demonstrated increased serum galectin-3 levels and placental galectin-3 production in preeclamptic patients, in comparison to women with uncomplicated pregnancy. Myocardial dysfunction and worse renal function parameters in patients with preeclampsia were not related to galectin-3. The main source of galectin-3 in maternal blood was its placental production. In the development of preeclampsia, galectin-3 may act as a compensatory mechanism to impaired placentation in early pregnancy.


Assuntos
Galectinas/sangue , Placenta/metabolismo , Pré-Eclâmpsia/sangue , Adulto , Biomarcadores/sangue , Proteínas Sanguíneas , Estudos de Casos e Controles , Feminino , Taxa de Filtração Glomerular , Humanos , Testes de Função Renal , Fator de Crescimento Placentário/sangue , Pré-Eclâmpsia/fisiopatologia , Gravidez
6.
Arch Gynecol Obstet ; 299(5): 1373-1384, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30762108

RESUMO

PURPOSE: To establish the surgical, demographic and histopathological factors associated with inaccurate sentinel lymph nodes (SLNs) identification using indocyanine green (ICG) and near-infrared (NIR) fluorescence imaging in uterine and cervical neoplasms during both open and laparoscopic surgery. METHODS: We reviewed patients with atypical endometrial hyperplasia (AEH), clinical stage I and II cervical cancer or uterine malignancies who underwent primary surgery with SLN mapping between September 2015 and January 2018. An analysis of patients' demographics, tumor factors and surgical approach was conducted. Bilateral and overall detection rates were calculated and univariate analysis was performed to estimate factors associated with failed SLN mapping. RESULTS: A total of 32 patients with uterine and cervical neoplasms were included in the study. The overall detection rate of the SLN was 84% and bilateral detection rate was 75%. There were no statistically relevant differences in overall and bilateral SLN detection rates by BMI, surgical approach or age. Regarding endometrial cancer, there were no differences in SLN detection rates when comparing tumor grade, histology nor myometrial invasion. For SLN detection failure, only the presence of metastatic lymph nodes and lack of surgical experience significantly increased the disability to detect SLNs (p = 0.03, p = 0.04, respectively). CONCLUSIONS: SLN mapping technique using NIR fluorescence imaging with ICG appears to be accurate method in most of the patients with cervical or endometrial carcinoma, regardless of demographic characteristics, tumor-related features and surgical approach. Surgeons' expertise in that field allows obtaining excellent detection rates.


Assuntos
Linfonodos/patologia , Biópsia de Linfonodo Sentinela/métodos , Linfonodo Sentinela/cirurgia , Neoplasias do Colo do Útero/diagnóstico , Neoplasias Uterinas/diagnóstico , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Verde de Indocianina , Pessoa de Meia-Idade , Estudos Retrospectivos , Neoplasias do Colo do Útero/patologia , Neoplasias Uterinas/patologia
7.
Phys Rev Lett ; 119(5): 052503, 2017 Aug 04.
Artigo em Inglês | MEDLINE | ID: mdl-28949741

RESUMO

We report the results of a ß-decay study of fission products ^{86}Br, ^{89}Kr, ^{89}Rb, ^{90gs}Rb, ^{90m}Rb, ^{90}Kr, ^{92}Rb, ^{139}Xe, and ^{142}Cs performed with the Modular Total Absorption Spectrometer (MTAS) and on-line mass-separated ion beams. These radioactivities were assessed by the Nuclear Energy Agency as having high priority for decay heat analysis during a nuclear fuel cycle. We observe a substantial increase in ß feeding to high excited states in all daughter isotopes in comparison to earlier data. This increases the average γ-ray energy emitted by the decay of fission fragments during the first 10 000 s after fission of ^{235}U and ^{239}Pu by approximately 2% and 1%, respectively, improving agreement between results of calculations and direct observations. New MTAS results reduce the reference reactor ν[over ¯]_{e} flux used to analyze reactor ν[over ¯]_{e} interaction with detector matter. The reduction determined by the ab initio method for the four nuclear fuel components, ^{235}U, ^{238}U, ^{239}Pu, and ^{241}Pu, amounts to 0.976, 0.986, 0.983, and 0.984, respectively.

8.
Support Care Cancer ; 25(8): 2399-2403, 2017 08.
Artigo em Inglês | MEDLINE | ID: mdl-28258502

RESUMO

PURPOSE: Early recognition of neoplastic pericarditis (npe) is crucial for the planning of subsequent therapy. The aim of the present study was to construct the scoring system assessing the probability of npe, in the patients requiring pericardial fluid (pf) drainage due to large pericardial effusion. METHODS: One hundred forty-six patients, 74 males and 72 females, entered the study. Npe based on positive pf cytology and/or pericardial biopsy specimen was recognised in 66 patients, non-npe in 80. Original scoring system was constructed based on parameters with the highest diagnostic value: mediastinal lymphadenopathy on chest CT scan, increased concentration of tumour markers (cytokeratin 19 fragments-Cyfra 21-1 and carcinoembryonic antigen-CEA) in pf, bloody character of pf, signs of imminent cardiac tamponade on echocardiography and tachycardia exceeding 90 beats/min on ECG. Each parameter was scored with positive or negative points depending on the positive and negative predictive values (PPV, NPV). RESULTS: The area under curve (AUC) for the scoring system was 0.926 (95%CI 0.852-0.963) and it was higher than AUC for Cyfra 21-1 0.789 (95%CI 0.684-0.893) or CEA 0.758 (95%CI 0.652-0.864). The score optimally discriminating between npe and non-npe was 0 points (sensitivity 0.84, specificity 0.91, PPV 0.9, NPV 0.85). CONCLUSION: Despite chest CT and tumour marker evaluation in pericardial fluid were good discriminators between npe and non-npe, the applied scoring system further improved the predicting of neoplastic disease in the studied population.


Assuntos
Antígeno Carcinoembrionário/metabolismo , Tamponamento Cardíaco/terapia , Derrame Pericárdico/complicações , Pericardite/diagnóstico , Tomografia Computadorizada por Raios X/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores Tumorais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Derrame Pericárdico/patologia , Pericardite/etiologia , Estudos Retrospectivos , Adulto Jovem
9.
Phys Rev Lett ; 117(9): 092501, 2016 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-27610847

RESUMO

We report total absorption spectroscopy measurements of ^{92}Rb, ^{96gs}Y, and ^{142}Cs ß decays, which are the most important contributors to the high energy ν[over ¯]_{e} spectral shape in nuclear reactors. These three ß decays contribute 43% of the ν[over ¯]_{e} flux near 5.5 MeV emitted by nuclear reactors. This ν[over ¯]_{e} energy is particularly interesting due to spectral features recently observed in several experiments including the Daya Bay, Double Chooz, and RENO Collaborations. Measurements were conducted at Oak Ridge National Laboratory by means of proton-induced fission of ^{238}U with on-line mass separation of fission fragments and the Modular Total Absorption Spectrometer. We observe a ß-decay pattern that is similar to recent measurements of ^{92}Rb, with a ground-state to ground-state ß feeding of 91(3)%. We verify the ^{96gs}Y ground-state to ground-state ß feeding of 95.5(20)%. Our measurements substantially modify the ß-decay feedings of ^{142}Cs, reducing the ß feeding to ^{142}Ba states below 2 MeV by 32% when compared with the latest evaluations. Our results increase the discrepancy between the observed and the expected reactor ν[over ¯]_{e} flux between 5 and 7 MeV, the maximum excess increases from ∼10% to ∼12%.

10.
Phys Rev Lett ; 117(9): 092502, 2016 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-27610848

RESUMO

The ß-delayed neutron emission of ^{83,84}Ga isotopes was studied using the neutron time-of-flight technique. The measured neutron energy spectra showed emission from states at excitation energies high above the neutron separation energy and previously not observed in the ß decay of midmass nuclei. The large decay strength deduced from the observed intense neutron emission is a signature of Gamow-Teller transformation. This observation was interpreted as evidence for allowed ß decay to ^{78}Ni core-excited states in ^{83,84}Ge favored by shell effects. We developed shell model calculations in the proton fpg_{9/2} and neutron extended fpg_{9/2}+d_{5/2} valence space using realistic interactions that were used to understand measured ß-decay lifetimes. We conclude that enhanced, concentrated ß-decay strength for neutron-unbound states may be common for very neutron-rich nuclei. This leads to intense ß-delayed high-energy neutron and strong multineutron emission probabilities that in turn affect astrophysical nucleosynthesis models.

11.
Int J Biol Markers ; 20(1): 43-9, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-15832772

RESUMO

A positive cytology result in pericardial fluid is the gold standard for recognition of malignant pericardial effusion. Unfortunately, in 30-50% of patients with malignant pericardial effusion cytological examination of the pericardial fluid is negative. Tumor marker assessment in pericardial fluid may help to recognize malignant pericardial effusion. The aim of our study was to estimate the value of CYFRA 21-1 and CEA measurement in pericardial fluid for the recognition of malignant pericardial effusion. To our knowledge this is the first study on CYFRA 21-1 assessment in pericardial effusion. The examined group consisted of 50 patients with malignant pericardial effusion and 34 patients with non-malignant pericardial effusion. Median CEA concentrations in malignant pericardial effusion and non-malignant pericardial effusion were 80 ng/mL (0-317) and 0.5 ng/mL (0-18.4), respectively (p<0.001). Median CYFRA 21-1 concentrations in malignant pericardial effusion and non-malignant pericardial effusion were 260 ng/mL (5.3-10080) and 22.4 ng/mL (1.87-317.6), respectively (p<0.001). The optimal cutoff value for CYFRA 21-1 in pericardial effusion was 100 ng/mL. CYFRA 21-1 >100 ng/mL or CEA >5 ng/mL were found in 14/15 patients with malignant pericardial effusion and negative pericardial fluid cytology. We therefore strongly recommend the use of CYFRA 21-1 and/or CEA in addition to pericardial fluid cytology for the recognition of malignant pericardial effusion.


Assuntos
Antígenos de Neoplasias/análise , Líquidos Corporais/química , Antígeno Carcinoembrionário/análise , Neoplasias Cardíacas/complicações , Neoplasias Cardíacas/diagnóstico , Pericardite/complicações , Pericardite/diagnóstico , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores Tumorais/análise , Feminino , Neoplasias Cardíacas/metabolismo , Neoplasias Cardíacas/patologia , Humanos , Queratina-19 , Queratinas , Masculino , Pessoa de Meia-Idade , Pericardite/metabolismo , Pericardite/patologia , Pericárdio/química , Curva ROC
12.
Int J Biol Markers ; 20(1): 43-49, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-28207101

RESUMO

A positive cytology result in pericardial fluid is the gold standard for recognition of malignant pericardial effusion. Unfortunately, in 30-50% of patients with malignant pericardial effusion cytological examination of the pericardial fluid is negative. Tumor marker assessment in pericardial fluid may help to recognize malignant pericardial effusion. The aim of our study was to estimate the value of CYFRA 21-1 and CEA measurement in pericardial fluid for the recognition of malignant pericardial effusion. To our knowledge this is the first study on CYFRA 21-1 assessment in pericardial effusion. The examined group consisted of 50 patients with malignant pericardial effusion and 34 patients with non-malignant pericardial effusion. Median CEA concentrations in malignant pericardial effusion and non-malignant pericardial effusion were 80 ng/mL (0-317) and 0.5 ng/mL (0-18.4), respectively (p<0.001). Median CYFRA 21-1 concentrations in malignant pericardial effusion and non-malignant pericardial effusion were 260 ng/mL (5.3-10080) and 22.4 ng/mL (1.87-317.6), respectively (p<0.001). The optimal cutoff value for CYFRA 21-1 in pericardial effusion was 100 ng/mL. CYFRA 21-1 >100 ng/mL or CEA >5 ng/mL were found in 14/15 patients with malignant pericardial effusion and negative pericardial fluid cytology. We therefore strongly recommend the use of CYFRA 21-1 and/or CEA in addition to pericardial fluid cytology for the recognition of malignant pericardial effusion. (Int J Biol Markers 2005; 20: 43-49).

13.
Eur Respir J ; 22(4): 649-53, 2003 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-14582919

RESUMO

Plasma brain natriuretic peptide (BNP), released from myocytes of ventricles upon stretch, has been reported to differentiate pulmonary from cardiac dyspnoea. Limited data have shown elevated plasma BNP levels in acute pulmonary embolism (APE), frequently accompanied by dyspnoea and right ventricular (RV) dysfunction. The aim of this study was to assess plasma N-terminal proBNP (NT-proBNP) in APE, and to establish whether it reflects the severity of RV overload and if it can be used to predict adverse clinical outcome. On admission, NT-proBNP and echocardiography for RV overload were performed in 79 APE patients (29 males), aged 63 +/- 16 yrs. Plasma NT-proBNP was elevated in 66 patients (83.5%) and was higher in patients with (median 4,650 pg x mL(-1) (range 61-60,958)) than without RV strain (363 pg x mL(-1) (16-16,329)). RV-to-left ventricular ratio and inferior vena cava dimension correlated with NT-proBNP. All 15 in-hospital deaths and 24 serious adverse events occurred in the group with elevated NT-proBNP, while all 13 (16.5%) patients with normal values had an uncomplicated clinical course. Plasma NT-proBNP predicted in-hospital mortality. Plasma N-terminal pro-brain natriuretic peptide is elevated in the majority of cases of pulmonary embolism resulting in right ventricular overload. Plasma levels reflect the degree of right ventricular overload and may help to predict short-term outcome. Acute pulmonary embolism should be considered in the differential diagnosis of patients with dyspnoea and abnormal levels of brain natriuretic peptide.


Assuntos
Proteínas do Tecido Nervoso/sangue , Fragmentos de Peptídeos/sangue , Embolia Pulmonar/sangue , Embolia Pulmonar/complicações , Disfunção Ventricular Direita/sangue , Disfunção Ventricular Direita/etiologia , Doença Aguda , Adulto , Idoso , Idoso de 80 Anos ou mais , Ecocardiografia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Peptídeo Natriurético Encefálico , Valor Preditivo dos Testes , Prognóstico , Embolia Pulmonar/diagnóstico , Índice de Gravidade de Doença , Disfunção Ventricular Direita/diagnóstico por imagem
14.
Br J Anaesth ; 90(1): 84-6, 2003 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-12488384

RESUMO

BACKGROUND: The aim of this paper is to compare the propofol concentration in blood and cerebrospinal fluid (CSF) in patients scheduled for different neurosurgical procedures and anaesthetized using propofol as part of a total intravenous anaesthesia technique. METHODS: Thirty-nine patients (ASA I-III) scheduled for elective intracranial procedures, were studied. Propofol was infused initially at 12 mg kg(-1) h(-1) and then reduced in steps to 9 and 6 mg kg(-1) h(-1). During anaesthesia, bolus doses of fentanyl and cis-atracurium were administered as necessary. After tracheal intubation the lungs were ventilated to achieve normocapnia with an oxygen-air mixture (FI(O(2))=0.33). Arterial blood and CSF samples for propofol examination were obtained simultaneously directly after intracranial drainage insertion and measured using high-performance liquid chromatography. The patients were divided into two groups depending on the type of neurosurgery. The Aneurysm group consisted of 13 patients who were surgically treated for ruptured intracranial aneurysm. The Tumour group was composed of 26 patients who were undergoing elective posterior fossa extra-axial tumour removal. RESULTS: Blood propofol concentrations in both groups did not differ significantly (P>0.05). The propofol concentration in CSF was 86.62 (SD 37.99) ng ml(-1) in the Aneurysm group and 50.81 (26.10) ng ml(-1) in the Tumour group (P<0.005). CONCLUSIONS: Intracranial pathology may influence CSF propofol concentration. However, the observed discrepancies may also result from quantitative differences in CSF composition and from restricted diffusion of the drug in the CSF.


Assuntos
Anestesia Intravenosa/métodos , Anestésicos Intravenosos/análise , Neoplasias Infratentoriais/sangue , Neoplasias Infratentoriais/líquido cefalorraquidiano , Aneurisma Intracraniano/sangue , Aneurisma Intracraniano/líquido cefalorraquidiano , Propofol/análise , Adulto , Idoso , Anestésicos Intravenosos/sangue , Anestésicos Intravenosos/líquido cefalorraquidiano , Humanos , Neoplasias Infratentoriais/cirurgia , Aneurisma Intracraniano/cirurgia , Pessoa de Meia-Idade , Propofol/sangue , Propofol/líquido cefalorraquidiano
15.
Med Sci Monit ; 7(6): 1334-8, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11687753

RESUMO

BACKGROUND: Understanding propofol distribution in blood is important for optimizing drug usage during TIVA. We studied changes in the propofol concentration in plasma and formed blood elements separated from blood samples taken before and after transfusion of blood cells to patients during TIVA with propofol. MATERIAL AND METHODS: Twelve patients were studied (ASA I-II). Propofol TIVA was performed at infusion rates of 12-9-6 mg x kg(-1) x h(-1). Fentanyl and pancuronium bromide were administered in fractional doses. After tracheal intubation the lungs were ventilated to normocapnia with oxygen-air mixture (FiO2=0.33). Blood samples for propofol analysis were taken 5 min before and 30 min after blood cell transfusion. At that point the propofol infusion rate was 6 mg x kg(-1) x h(-1). Propofol concentrations were measured by means of HPLC. RESULTS: Blood cell transfusion leads to a change in the propofol level in plasma and formed blood elements. The transfusion process lowers the ratio of the plasma propofol concentration to the propofol concentration in formed blood elements. CONCLUSIONS: Formed blood elements show a greater ability to bind propofol after transfusion of 5-15 day erythrocytes.


Assuntos
Anestésicos Intravenosos/sangue , Transfusão de Componentes Sanguíneos , Propofol/sangue , Adulto , Cromatografia Líquida de Alta Pressão , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
16.
Biomed Chromatogr ; 15(6): 408-12, 2001 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11559926

RESUMO

In order to describe the changes of propofol concentration in whole blood and in its components during the blood storage we examined venous blood samples collected from patients anaesthetized either with or without propofol. Blood samples from patients anaesthetized without propofol were spike with propofol 45 min before analysis. Propofol concentration was examined in whole blood, plasma, rinsed formed elements and rinsed and lysed formed blood elements by means of HPLC after 1, 4, 7, 13, 21, 25 and 28 days of storage. There was significant decrease in plasma concentration of propofol during the first few days of sample storage followed by its increase during subsequent days. The opposite phenomenon was observed for formed blood elements. The findings support the hypothesis that propofol distribution between blood components changes in time.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Propofol/sangue , Manejo de Espécimes , Anestésicos Intravenosos/sangue , Humanos
17.
Anesthesiology ; 93(4): 992-7, 2000 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11020752

RESUMO

BACKGROUND: The metabolism of propofol is very rapid, and its transformation takes place mainly in the liver. There are reports indicating extrahepatic metabolism of the drug, and the alimentary canal, kidneys, and lungs are mentioned as the most probable places where the process occurs. The aim of this study was to determine whether the human lungs really take part in the process of propofol biotransformation. METHODS: Blood samples were taken from 55 patients of American Society of Anesthesiologists grade 1-3 scheduled for elective intracranial procedures (n = 47) or for pulmonectomy (n = 8). All patients were premedicated with diazepam (10 mg) administered orally 2 h before anesthesia. Propofol total intravenous anesthesia was performed at the following infusion rates: 12 mg. kg-1. h-1, 9 mg. kg-1. h-1, and 6 mg. kg-1. h-1. Fentanyl and pancuronium bromide were also administered intermittently. After tracheal intubation, the lungs were ventilated to normocapnia with an oxygen-air mixture (fraction of inspired oxygen = 0.33). Blood samples for propofol and 2,6-diisopropyl-1, 4-quinol analysis were taken simultaneously from the right atrium and the radial artery, or the pulmonary artery and the radial artery. The concentration of both substances were measured with high-performance liquid chromatography and gas chromatography-mass spectroscopy. RESULTS: The concentration of propofol in the central venous system (right atrium or pulmonary artery) is greater than in the radial artery, whereas the opposite is observed for propofol's metabolite, 2,6-diisopropyl-1,4-quinol. Higher propofol concentrations are found in blood taken from the pulmonary artery than in the blood collected from the radial artery. CONCLUSIONS: Human lungs take part in the elimination of propofol by transforming the drug into 2,6-diisopropyl-1,4-quinol.


Assuntos
Anestésicos Intravenosos/farmacocinética , Pulmão/metabolismo , Propofol/farmacocinética , Anestésicos Intravenosos/sangue , Biotransformação , Cromatografia Líquida de Alta Pressão , Feminino , Cromatografia Gasosa-Espectrometria de Massas , Átrios do Coração , Humanos , Hidroquinonas/sangue , Pulmão/cirurgia , Masculino , Pessoa de Meia-Idade , Propofol/sangue , Artéria Radial
20.
Biomed Chromatogr ; 14(4): 249-55, 2000 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-10861736

RESUMO

Due to unsatisfactory equipment efficiency and the time consuming manual procedures of sample preparation, drug analyses in physiological fluids and tissues frequently have to be carried out a few days after the sample collection. This is especially the case with investigations which require the examination of materials for which a large number of samples is necessary. The paper deals with the influence of storing blood samples on the level of propofol in blood and plasma. Propofol (2,6-diisopropylphenol, Diprivan) is a very popular intravenous agent used both for the induction and the maintenance of anaesthesia in human and veterinary patients as well as in laboratory animals. The results obtained show that, due to distinct losses of propofol in samples during their storage, the comparison of data estimated for subsequent days after sampling can lead to misleading or even wrong conclusions. The speed of drug diminution depends both on the type of blood and the anticoagulant used. The established interdependencies between the change in the level of propofol in blood and plasma samples and their storage time show that analogous investigations of other pharmaceutical agents are necessary.


Assuntos
Anestésicos Intravenosos/sangue , Propofol/sangue , Anticoagulantes/sangue , Calibragem , Humanos , Indicadores e Reagentes , Soluções , Manejo de Espécimes , Fatores de Tempo
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