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1.
Sci Rep ; 13(1): 2204, 2023 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-36750627

RESUMO

This paper is a contribution to the development of microwave plasma-based technology aimed at efficient hydrogen (H2) production from a so-called synthetic biogas, considered a mixture of methane (CH4) and carbon dioxide (CO2), which can contain up to 70% CH4. In this work, we tested the performance of a waveguide-supplied metal cylinder-based microwave plasma source (MPS) operating at 915 MHz at atmospheric pressure as a tool for the efficient production of H2 in the steam reforming of the synthetic biogas. The test showed that the steam reforming of the synthetic biogas could be carried out under a wide range of working parameters without soot formation and extinction of the microwave discharge. We found that there is a minimal H2Osteam consumption rate for a given CH4 input volume content, which ensures stable operation of the MPS (no soot). The experiments did not show that increasing the amount of H2Osteam rate above the minimal value for a given CH4 input volume content results in an increase in the H2 production rate, energy yield, CH4 conversion degree, and H2 output concentration. To describe the MPS performance, which also takes into account a factor of the utilization of the CH4 feedstock, we introduced a new parameter, called an energy-CH4 feedstock consumption yield. The best results in terms of the H2 production rate, the energy yield, and the CH4 conversion degree were 239 g[H2]/h 36.8 g[H2]/kWh, and 74.3%, respectively. This shows that the application of the steam reforming, instead of the dry reforming, resulted in a 1.5-fold increase of the H2 production rate and the corresponding energy yield.

2.
Lipids Health Dis ; 22(1): 2, 2023 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-36624488

RESUMO

BACKGROUND: The development of coronary artery disease (CAD) is related to the impaired quantity and composition of inflammatory proteins found in plasma and tissue, such as interleukin 6 (IL-6), adipokines, and resistin. Therefore, the level of plasma resistin in patients with advanced CAD could be indicative of the condition of epicardial adipose tissue and thus have an impact on the frequency and severity of postoperative complications in the form of paroxysmal atrial fibrillation. METHODS: The study included 108 patients who qualified for elective coronary artery bypass grafting (CABG) surgery from 2017 to 2020 and were categorized into two groups. The first group consisted of patients who developed atrial fibrillation in the postoperative period - the AF group, and the second group included patients who did not have arrhythmia - the non-AF group. The analysis incorporates the history, course of treatment, anthropometric characteristics of the test subjects, biochemical laboratory tests, and echocardiography. Perivascular adipose tissue (PVAT) sections were surgically harvested from the area of the left coronary trunk. RESULTS: The resistin levels in the PVAT were significantly higher in the AF group than in the non-AF group (P = 0.000015). Similarly, plasma resistin levels increased significantly in the AF group compared to the non-AF group (P = 0.044). The values of other analyzed variables were not significantly different (analysis performed using the Mann-Whitney U test). Spearman's rank-order correlation technique found a correlation between resistin in PVAT and plasma (r = 0.5933; P < 0.0001) in the whole study group, as well as in the AF group (r = 0.4782; P = 0.021) and the non-AF group (r = 0.4938; P < 0.0001). A correlation arose between the level of resistin in PVAT and the level of hsCRP (r = 0.3463; P = 0.005) in the whole study group and the non-AF group (r = 0.4448; P = 0.0011); however, no such correlation appeared in the AF group (r = 0.3076; P = 0.306). CONCLUSIONS: Elevated levels of plasma resistin, which reflect PVAT resistin levels in patients qualified for myocardial revascularisation, may be associated with postoperative atrial fibrillation complications.


Assuntos
Fibrilação Atrial , Doença da Artéria Coronariana , Humanos , Tecido Adiposo/metabolismo , Fibrilação Atrial/diagnóstico , Fibrilação Atrial/etiologia , Biomarcadores , Ponte de Artéria Coronária , Doença da Artéria Coronariana/complicações , Período Pós-Operatório , Resistina
3.
Physiol Res ; 70(4): 543-550, 2021 08 31.
Artigo em Inglês | MEDLINE | ID: mdl-34062078

RESUMO

Higher serum resistin levels were reported to be associated with increased mortality risk. We aimed to assess the predictive value of resistin levels in perivascular adipose tissue (PVAT) around the left main coronary artery (LMCA) for mid-term survival of patients with advanced coronary artery disease (CAD).This was a prospective study including patients referred for elective coronary artery grafting in 2016 and 2017, performed using a standard approach. A sample of PVAT was harvested and resistin levels were measured using an enzyme-linked immunosorbent assay. Patients were followed from the day of the procedure until March 2021. In each patient, the SYNTAX score and EuroSCORE II were calculated. The study included 108 patients aged 68.1 ±7.9 years, including 83 men (76.9%). The duration of follow-up was 731 (range, 275-1020) for nonsurvivors and 1418 median (range, 1174-1559) for survivors (p <0.001). Patients who died had a higher SYNTAX score, higher EuroSCORE II, and lower resistin levels in PVAT than survivors (p <0.001, p = 0.004, and p = 0.041, respectively). A stepwise regression analysis revealed that survival was related to resistin concentrations above the median value (hazard ratio [HR], 4.67; 95% CI, 1.02-21.4; p = 0.048) and EuroSCORE II (used as continuous variable; HR, 1.55; 95% CI, 1.16-2.07; p = 0.003). The mid-term mortality in patients with advanced CAD is associated with low resistin concentrations in PVAT surrounding the LMCA.


Assuntos
Tecido Adiposo/metabolismo , Ponte de Artéria Coronária , Doença da Artéria Coronariana/cirurgia , Resistina/metabolismo , Idoso , Biomarcadores/metabolismo , Ponte de Artéria Coronária/efeitos adversos , Ponte de Artéria Coronária/mortalidade , Doença da Artéria Coronariana/diagnóstico por imagem , Doença da Artéria Coronariana/metabolismo , Doença da Artéria Coronariana/mortalidade , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Estudos Prospectivos , Medição de Risco , Fatores de Risco , Fatores de Tempo , Resultado do Tratamento
4.
BMC Microbiol ; 21(1): 32, 2021 01 22.
Artigo em Inglês | MEDLINE | ID: mdl-33482722

RESUMO

BACKGROUND: DNA binding KfrA-type proteins of broad-host-range bacterial plasmids belonging to IncP-1 and IncU incompatibility groups are characterized by globular N-terminal head domains and long alpha-helical coiled-coil tails. They have been shown to act as transcriptional auto-regulators. RESULTS: This study was focused on two members of the growing family of KfrA-type proteins encoded by the broad-host-range plasmids, R751 of IncP-1ß and RA3 of IncU groups. Comparative in vitro and in silico studies on KfrAR751 and KfrARA3 confirmed their similar biophysical properties despite low conservation of the amino acid sequences. They form a wide range of oligomeric forms in vitro and, in the presence of their cognate DNA binding sites, they polymerize into the higher order filaments visualized as "threads" by negative staining electron microscopy. The studies revealed also temperature-dependent changes in the coiled-coil segment of KfrA proteins that is involved in the stabilization of dimers required for DNA interactions. CONCLUSION: KfrAR751 and KfrARA3 are structural homologues. We postulate that KfrA type proteins have moonlighting activity. They not only act as transcriptional auto-regulators but form cytoskeletal structures, which might facilitate plasmid DNA delivery and positioning in the cells before cell division, involving thermal energy.


Assuntos
Proteínas de Bactérias/metabolismo , Proteínas do Citoesqueleto/química , Proteínas do Citoesqueleto/metabolismo , Proteínas de Ligação a DNA/metabolismo , Escherichia coli/genética , Plasmídeos/genética , Proteínas de Bactérias/química , Proteínas de Bactérias/genética , Sítios de Ligação , Simulação por Computador , Conjugação Genética , Proteínas do Citoesqueleto/genética , Proteínas de Ligação a DNA/química , Escherichia coli/química , Escherichia coli/metabolismo , Transcrição Gênica
5.
Forensic Sci Int ; 258: 41-9, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26646737

RESUMO

This paper describes the creation of the Polish Genetic Database of Victims of Totalitarianism and the first research conducted under this project. On September 28th 2012, the Pomeranian Medical University in Szczecin and the Institute of National Remembrance-Commission for Prosecution of Crimes against the Polish Nation agreed to support the creation of the Polish Genetic Database of Victims of Totalitarianism (PBGOT, www.pbgot.pl). The purpose was to employ state-of-the-art methods of forensic genetics to identify the remains of unidentified victims of Communist and Nazi totalitarian regimes. The database was designed to serve as a central repository of genetic information of the victim's DNA and that of the victim's nearest living relatives, with the goal of making a positive identification of the victim. Along the way, PGBOT encountered several challenges. First, extracting useable DNA samples from the remains of individuals who had been buried for over half a century required forensic geneticists to create special procedures and protocols. Second, obtaining genetic reference material and historical information from the victim's closest relatives was both problematic and urgent. The victim's nearest living relatives were part of a dying generation, and the opportunity to obtain the best genetic and historical information about the victims would soon die with them. For this undertaking, PGBOT assembled a team of historians, archaeologists, forensic anthropologists, and forensic geneticists from several European research institutions. The field work was divided into five broad categories: (1) exhumation of victim remains and storing their biological material for later genetic testing; (2) researching archives and historical data for a more complete profile of those killed or missing and the families that lost them; (3) locating the victim's nearest relatives to obtain genetic reference samples (swabs), (4) entering the genetic data from both victims and family members into a common database; (5) making a conclusive, final identification of the victim. PGBOT's first project was to identify victims of the Communist regime buried in hidden mass graves in the Powazki Military Cemetery in Warsaw. Throughout 2012 and 2013, PGBOT carried out archaeological exhumations in the Powazki Military Cemetery that resulted in the recovery of the skeletal remains of 194 victims in several mass graves. Of the 194 sets of remains, more than 50 victims have been successfully matched and identified through genetic evidence.


Assuntos
Impressões Digitais de DNA , Bases de Dados Genéticas , Prisioneiros , Osso e Ossos/química , Comunismo , DNA/genética , DNA/isolamento & purificação , Exumação , Testes Genéticos , História do Século XX , Humanos , Repetições de Microssatélites , Socialismo Nacional , Polônia , Reação em Cadeia da Polimerase , Dente/química
6.
Transplant Proc ; 42(5): 1614-7, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-20620485

RESUMO

BACKGROUND: We investigated the influence of catalase and aminotriasol on reactions of the smooth muscle cells induced by angiotensin II (ANG II) after ischemia-reperfusion (I/R). MATERIALS AND METHODS: Experiments were performed on perfused male Wistar rat tail arteries. Using classical pharmacometric methods we analyzed the influence of ANG II on vascular contraction, in the presence of catalase and aminotriazole, and after I/R. RESULTS: A reduction in maximal response and increased EC(5) value were observed after ischemia, while an increased maximal response and decrease EC(50) value were observed after reperfusion. Catalase decreased and aminotriasol increased maximal responses to ANG II. In the presence of catalase, reduction of the maximal response and increase in EC(50) value were observed after reperfusion. In the presence of aminotriasol, we observed increased maximal response and decreased EC(50) value after I/R. CONCLUSION: Ischemia reduced and reperfusion increased the responses of vascular smooth muscle cells to ANG II. Catalase decreased and aminotriasol increased hyperreactivity of arteries to ANG II after reperfusion. These results suggested that antioxidative system modulates reactions induced by ANG II. Reperfusion impairs the balance between antioxidants and the production of reactive oxygen species.


Assuntos
Amitrol (Herbicida)/uso terapêutico , Artérias/fisiologia , Traumatismo por Reperfusão/prevenção & controle , Angiotensina II/farmacologia , Animais , Artérias/efeitos dos fármacos , Catalase/farmacologia , Isquemia/fisiopatologia , Masculino , Ratos , Ratos Wistar , Reperfusão , Cauda/irrigação sanguínea
7.
Heart ; 96(2): 113-7, 2010 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19561363

RESUMO

AIMS: The authors investigated the additive prognostic value of the 6-minute walk test (6MWT) to Euroscore in patients with severe aortic stenosis undergoing aortic valve replacement (AVR) METHODS AND RESULTS: 208 patients with severe AS underwent the 6MWT before AVR, as part of a randomised trial (ASSERT) comparing stented and stentless aortic valves. Clinical follow-up was available for 200 patients up to 12 months. The rate of death, myocardial infarction (MI) or stroke (time to first event) was 13% (n = 14) in patients walking <300 metres compared to 4% (n = 4) in those who walked > or =300 metres (p = 0.017). When rate of death, MI or stroke by Euroscore risk was stratified by 6-minute walking distance, the 6MWT added prognostic information. In a Cox regression analysis 6MWT distance was the only variable retained as an independent predictor of the composite outcome of death, MI or stroke at 12 months (HR 0.28 95% CI 0.09 to 0.85, p = 0.025). CONCLUSIONS: The 6MWT is safe and feasible to carry out in patients with severe aortic stenosis before AVR, and provides potentially important functional and prognostic information to clinical assessment and the Euroscore risk score.


Assuntos
Estenose da Valva Aórtica/cirurgia , Teste de Esforço/métodos , Exercício Físico/fisiologia , Insuficiência Cardíaca/diagnóstico , Caminhada/fisiologia , Idoso , Valva Aórtica , Feminino , Próteses Valvulares Cardíacas , Implante de Prótese de Valva Cardíaca/instrumentação , Humanos , Estimativa de Kaplan-Meier , Masculino , Cuidados Pré-Operatórios , Prognóstico , Stents
8.
Exp Oncol ; 32(4): 228-32, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21270749

RESUMO

UNLABELLED: Some prostate cancers are clinically significant (i.e. life-threatening) but others are not. Small proportion of elderly men dies of prostate cancer while most of them harbor tumor lesions in their prostates. The aim of this paper was to present late-life form of the prostate cancer, which differs from its aggressive counterpart that affects men between 55-65 years old and younger. The differences can be found in carcinogenesis risk factors, cancer biology and finally patients' survival. The most important is that these two clinical (age-related) forms of the prostate cancer are still undistinguishable in clinico-pathology reports and patients bearing different diseases are offered the same treatment. Potential mechanisms leading to development of the late-life clinically indolent prostate cancer are discussed. It seems that the key abnormalities are proteins involved in control of regenerative potential and cell senescence. CONCLUSIONS: We postulate that late-life low-grade (clinically indolent) prostate cancer subcategory should be established. This type of «cancer¼ should rather be viewed as a senescence-related feature and probably not treated at all.


Assuntos
Senescência Celular/fisiologia , Neoplasias da Próstata/epidemiologia , Neoplasias da Próstata/patologia , Idoso , Idoso de 80 Anos ou mais , Transformação Celular Neoplásica , Humanos , Masculino , Células-Tronco Neoplásicas/patologia
9.
Transplant Proc ; 39(9): 2905-7, 2007 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-18022013

RESUMO

UNLABELLED: Neurologic complications may occur in patients undergoing haematopoietic stem cell transplantation (HSCT). The aim of the study was to evaluate the frequency and type of neurologic complications in children after HSCT. We performed a retrospective analysis of the incidence and outcome of neurologic complications among 171 consecutive children transplanted in one center. RESULTS: Among 84 autologous and 87 allogeneic (47 matched sibling donors, 31 matched unrelated donors, 8 mismatched family donors, and 1 cord blood) transplants, 7 patients (4%) developed neurologic complications, all of whom had undergone allogeneic transplantation (7/87 = 8%). These patients had relapses of acute leukemia (n = 3; acute myeloblastic in two and acute lymphoblastic in one), chronic leukemia, (n = 1), myelodysplastic syndrome (n = 2), and adrenoleudystrophy X (n = 1). Neurologic complications occurred after a median follow-up of 1 month (range, 14 days to 19 months). Of seven patients, four died. Neurologic complications were the cause in two patients. CONCLUSIONS: Among the analyzed material the risk of neurologic complications was lower than in other studies and these events were observed only in children undergoing allogeneic transplantation.


Assuntos
Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Doenças do Sistema Nervoso/epidemiologia , Adolescente , Criança , Pré-Escolar , Feminino , Humanos , Leucemia/terapia , Masculino , Síndromes Mielodisplásicas/terapia , Estudos Retrospectivos , Transplante Autólogo/efeitos adversos , Transplante Homólogo/efeitos adversos
10.
Transplant Proc ; 39(5): 1350-3, 2007 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-17580137

RESUMO

INTRODUCTION: This study sought to investigate the mechanisms of relaxation induced by the (nitric oxide (NO)-independent soluble guanylyl cyclase (sGC) stimulators 3-[5'-hydroxymethyl-2'-furyl]-1-benzylindazole (YC-1) in human mesenteric arteries relaxed and precontracted with 1 micromol/L 5-hydroxytryptamine (serotonin). MATERIAL AND METHODS: Human mesenteric arteries obtained during kidney retrieval were preserved in the same conditions as transplanted kidneys. All experiments were performed after reperfusion with Krebs buffer in 37 degrees C and 100% oxygen exposure. RESULTS: In endothelium-intact rings, YC-1 (0.001 to 30 mmol/L) caused concentration-dependent relaxation (pEC(50): 6.59 +/- 0.12), which shifted to the right in endothelium-denuded rings. The sGC inhibitor 1H- [1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ 10 mmol/L) partially attenuated the maximal responses to YC-1 (E(max) = 51.30% +/- 3.70%; n = 6) and displaced its curve to the right in intact and denuded vessels. Both, the NO synthesis inhibitor N-nitro-L-arginine methyl ester (100 mmol/L) and the NO scavenger carboxy-2-[4-carboxyphenyl]-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (100 mmol/L) significantly reduced YC-1 relaxation. The sodium pump inhibitor ouabain (1 micromol/L) produced a greater decrease in the vasodilator response of YC-1 (E(max) = 18.7% +/- 4.55%; n = 9). ODQ (10 micromol/L) plus 1 mumol/L ouabain abolished the relaxant response of YC-1 (E(max) = 9.4% +/- 2.94%, n = 9). CONCLUSIONS: This study demonstrated that sodium pump stimulation by YC-1 as an additional mechanism of sGC activation independent of cGMP relaxed human mesenteric artery, including blockade of Ca(2+) influx. Furthermore, this study suggested an ability of NO to mediate relaxation of resistance-like arteries through the activation of soluble guanylate cyclase and K(+) channels.


Assuntos
Endotélio Vascular/fisiologia , Indazóis/uso terapêutico , Transplante de Rim/fisiologia , Artéria Mesentérica Superior/fisiologia , Inibidores da Agregação Plaquetária/uso terapêutico , Pressão Sanguínea/efeitos dos fármacos , Endotélio Vascular/efeitos dos fármacos , Inibidores Enzimáticos/uso terapêutico , Humanos , Artéria Mesentérica Superior/efeitos dos fármacos , NG-Nitroarginina Metil Éster/uso terapêutico , Preservação de Órgãos , Oxidiazóis/uso terapêutico , Quinoxalinas/uso terapêutico , Estudos Retrospectivos , Vasodilatação/efeitos dos fármacos , Vasodilatação/fisiologia , Vasodilatadores/uso terapêutico
12.
Heart Surg Forum ; 7(5): E462-5; discussion E462-5, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-15799926

RESUMO

Early regional performance and hypertrophy regression after stentless aortic valve replacement are still incompletely characterized. We compared early postoperative changes of segmental thickness and function after stentless and stented aortic valve replacement as assessed by cardiac magnetic resonance (CMR). In 16 patients randomly assigned to stented (Mosaic, 8 patients) and stentless (Freestyle, 8 patients) groups, 4 parallel short-axis images at the level of the apex (slice 4), midventricle (slices 2-3), and mitral valve (slice 1) were obtained with a 1.5 T CMR scanner (Magnetom Sonata, Siemens) before and 1 month after surgery. Cine images were obtained using an echo gradient sequence. Left ventricle mass was calculated as the difference between the left ventricular end-diastolic volume at the epicardial and endocardial borders multiplied by a myocardium density factor (1.05). Each slice was divided into 8 segments (octants) from anterior (octant I-II) to septal (octant V-VIII). A total of 32 segments encompassed the entire heart. From each of these elements end diastolic thickness and systolic function (fractional thickening) were calculated. In stentless valves significant reduction of septal octant thickness on the midventricular slice was noted. There was no difference in regional systolic function-segment thickening. In stented valves no segmental thickness changes were observed. In stentless valves there was early postoperative thickness reduction of septal segments at the midventricular level. However, this finding did not coincide with changes in segmental function.


Assuntos
Próteses Valvulares Cardíacas/efeitos adversos , Hipertrofia Ventricular Esquerda/diagnóstico , Hipertrofia Ventricular Esquerda/etiologia , Disfunção Ventricular Esquerda/diagnóstico , Disfunção Ventricular Esquerda/etiologia , Idoso , Feminino , Humanos , Masculino , Stents , Resultado do Tratamento
13.
Dev Med Child Neurol ; 44(10): 666-75, 2002 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-12418791

RESUMO

This study evaluated the efficacy and safety of three doses of botulinum toxin A (BTX-A; Dysport) in 125 patients (mean age 5.2 years, SD 2; 54% male)with dynamic equinus spasticity during walking. Participants were randomized to receive Dysport (10, 20, or 30 units/kg) or placebo to the gastrocnemius muscle of both legs. Muscle length was calculated from electrogoniometric measurements and the change in the dynamic component of gastrocnemius shortening at four weeks was prospectively identified as the primary outcome measure. All treatment groups showed statistically significant decreases in dynamic component compared with placebo at 4 weeks. Mean improvement in dynamic component was most pronounced in the 20 units/kg group, being equivalent to an increase in dorsiflexion with the knee extended at 19 degrees, and was still present at 16 weeks. The safety profile of the toxin appears satisfactory.


Assuntos
Toxinas Botulínicas Tipo A/administração & dosagem , Paralisia Cerebral/tratamento farmacológico , Espasticidade Muscular/tratamento farmacológico , Toxinas Botulínicas Tipo A/efeitos adversos , Paralisia Cerebral/diagnóstico , Criança , Pré-Escolar , Relação Dose-Resposta a Droga , Método Duplo-Cego , Feminino , Humanos , Injeções Intramusculares , Masculino , Espasticidade Muscular/diagnóstico , Músculo Esquelético/efeitos dos fármacos , Exame Neurológico/efeitos dos fármacos , Resultado do Tratamento , Caminhada
14.
J Cardiovasc Surg (Torino) ; 43(3): 313-7, 2002 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-12055562

RESUMO

BACKGROUND: Stentless bioprostheses are anticipated to cause improved hemodynamics and increased longevity over stented bioprosthesis. We have compared echocardiographic analysis of stented bioprosthesis "Freestyle" with stented "Mosaic" bioprosthesis. Because of similar technology (0 pressure fixation, anticalcification) any differences may relate to stent. METHODS: Twenty-eight patients undergoing AVR were randomly assigned to receive either stented or stentless. Echocardiograms, by means of M-mode and Doppler were performed early, 3-6 months and 1 year postoperatively. RESULTS: The peak flow velocity was significantly lower in the stentless group, especially 1 week and 6 months after surgery. Mean transvalvular gradient dropped significantly in stentless group and did not change in stented group. EOA did not change significantly in either of groups. AoV velocity time integral was increasing in stentless group. LV mass had fallen significantly in both groups but degree of mass reduction was comparable. CONCLUSIONS: There are marked improvements of stentless valves hemodynamics. However it is not necessary equal to higher degree of LV mass reduction during 1 year follow-up.


Assuntos
Estenose da Valva Aórtica/cirurgia , Bioprótese , Próteses Valvulares Cardíacas , Hemodinâmica/fisiologia , Stents , Valva Aórtica , Velocidade do Fluxo Sanguíneo , Ecocardiografia , Seguimentos , Implante de Prótese de Valva Cardíaca , Humanos , Hipertrofia Ventricular Esquerda/diagnóstico por imagem , Estudos Prospectivos , Fatores de Tempo
15.
Blood ; 98(7): 2248-55, 2001 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-11568013

RESUMO

Patients with paroxysmal nocturnal hemoglobinuria (PNH) have blood cells deficient in glycosyl phosphatidylinositol (GPI)-linked proteins owing to a somatic mutation in the X-linked PIGA gene. To target Piga recombination to the erythroid/megakaryocytic lineage in mice, the Cre/loxP system was used, and Cre was expressed under the transcriptional regulatory sequences of GATA-1. Breeding of GATA1-cre (G) transgenic mice with mice carrying a floxed Piga (L) allele was associated with high embryonic lethality. However, double-transgenic (GL) mice that escaped early recombination looked healthy and were observed for 16 months. Flow cytometric analysis of peripheral blood cells showed that GL mice had up to 100% of red cells deficient in GPI-linked proteins. The loss of GPI-linked proteins on the cell surface occurred late in erythroid differentiation, causing a proportion of red cells to express low residual levels of GPI-linked proteins. Red cells with residual expression of GPI-linked proteins showed an intermediate sensitivity toward complement and thus resemble PNH type II cells in patients with PNH. Recombination of the floxed Piga allele was also detected in cultured megakaryocytes, mast cells, and eosinophils, but not in neutrophils, lymphocytes, or nonhematopoietic tissues. In summary, GATA1-Cre causes high-efficiency Piga gene inactivation in a GATA-1-specific pattern. For the first time, mice were generated that have almost 100% of red cells deficient in GPI-linked proteins. These animals will be valuable to further investigate the consequences of GPI-anchor deficiency on erythroid/megakaryocytic cells.


Assuntos
Proteínas de Ligação a DNA/farmacologia , Eritropoese/efeitos dos fármacos , Inativação Gênica/efeitos dos fármacos , Glicosilfosfatidilinositóis/deficiência , Integrases/farmacologia , Proteínas de Membrana/genética , Fatores de Transcrição/farmacologia , Proteínas Virais/farmacologia , Animais , Células da Medula Óssea/metabolismo , Linhagem da Célula , Proteínas de Ligação a DNA/fisiologia , Eosinófilos/citologia , Eosinófilos/efeitos dos fármacos , Eosinófilos/metabolismo , Eritrócitos/citologia , Eritrócitos/efeitos dos fármacos , Eritrócitos/metabolismo , Fatores de Ligação de DNA Eritroide Específicos , Fator de Transcrição GATA1 , Hemoglobinúria Paroxística/patologia , Integrases/fisiologia , Fígado/citologia , Fígado/embriologia , Fígado/metabolismo , Mastócitos/citologia , Mastócitos/efeitos dos fármacos , Mastócitos/metabolismo , Megacariócitos/citologia , Megacariócitos/efeitos dos fármacos , Megacariócitos/metabolismo , Camundongos , Camundongos Transgênicos , Recombinação Genética , Fatores de Transcrição/fisiologia , Proteínas Virais/fisiologia
17.
Plant Cell ; 13(5): 1095-107, 2001 May.
Artigo em Inglês | MEDLINE | ID: mdl-11340184

RESUMO

ATP binding cassette (ABC) transporters, which are found in all species, are known mainly for their ability to confer drug resistance. To date, most of the ABC transporters characterized in plants have been localized in the vacuolar membrane and are considered to be involved in the intracellular sequestration of cytotoxins. Working on the assumption that certain ABC transporters might be involved in defense metabolite secretion and their expression might be regulated by the concentration of these metabolites, we treated a Nicotiana plumbaginifolia cell culture with sclareolide, a close analog of sclareol, an antifungal diterpene produced at the leaf surface of Nicotiana spp; this resulted in the appearance of a 160-kD plasma membrane protein, which was partially sequenced. The corresponding cDNA (NpABC1) was cloned and shown to encode an ABC transporter. In vitro and in situ immunodetection showed NpABC1 to be localized in the plasma membrane. Under normal conditions, expression was found in the leaf epidermis. In cell culture and in leaf tissues, NpABC1 expression was strongly enhanced by sclareolide and sclareol. In parallel with NpABC1 induction, cells acquired the ability to excrete a labeled synthetic sclareolide derivative. These data suggest that NpABC1 is involved in the secretion of a secondary metabolite that plays a role in plant defense.


Assuntos
Antifúngicos/metabolismo , Membrana Celular/metabolismo , Diterpenos/metabolismo , Proteínas de Plantas/metabolismo , Sequência de Aminoácidos , Transporte Biológico Ativo , Compartimento Celular , Clonagem Molecular , Regulação da Expressão Gênica de Plantas , Dados de Sequência Molecular , Folhas de Planta/metabolismo , Proteínas de Plantas/genética , Plantas Tóxicas , Análise de Sequência de DNA , Nicotiana/genética , Nicotiana/metabolismo
18.
Anal Chem ; 72(16): 3752-6, 2000 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-10959959

RESUMO

A new electrically heated carbon paste electrode has been developed for performing adsorptive stripping measurements of trace nucleic acids. Such coupling of electrochemistry at electrically heated electrodes with adsorptive constant-current stripping chronopotentiometry offers distinct advantages for trace measurements of nucleic acids. The application of increased temperatures during the deposition step results in dramatic (4-34-fold, depending on temperature applied) enhancement of the stripping signal. Such improvement is attributed to the accumulation step at the heated electrode. Forced thermal convection near the electrode surface facilitates the use of quiescent solutions and hence of ultrasmall volumes. Using an electrode temperature of 32 degrees C and a quiescent solution during the 1-min accumulation, the response is linear over the 1-8 mg/L range tested, with a detection limit of 0.5 mg/L. Such electrode heating technology offers great promise for various applications involving thermal manipulations of nucleic acids.


Assuntos
Eletrodos , Ácidos Nucleicos/análise , Carbono , Temperatura Alta
19.
J Cardiovasc Surg (Torino) ; 41(2): 181-6, 2000 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-10901519

RESUMO

BACKGROUND: We report the mid-term results of a prospective trial of a new bioprosthetic valve. The Mosaic bioprosthesis consists of porcine aortic valve that has been cross linked ed in glutaraldehyde solution under zero-pressure fixation and treated with alpha amino oleic acid to reduce the potential for calcification. METHODS: Mosaic bioprosthetic valve replacement was performed in 67 consecutive patients between January 1995 and August 1998. There were 37 patients having aortic valve replacement (AVR) and 30 having mitral valve replacement (MVR) who entered this study. The patients age ranged 56 to 86 years (mean 74.9); 38 were female and 29 were male; 44 were in NYHA grade 3 and 21 were NYHA grade 4. All mitral valve replacements were performed with total preservation of subvalvular apparatus. Echocardiographic assessment of valve and LV function were performed on 7th day, 6 months 1,2 and 3 years. RESULTS: There was no hospital mortality. 3 year survival was 85.9+/-5.9% for AVR and 100% for MVR. Freedom from antithromboembolic related haemorrhage has been 96.7% for MVR and 91.9% for AVR. Freedom from the transient neurological event was 96.7+/-3.3% for MVR and 100% for AVR Freedom from structural valve failure, permanent thromboembolism, thrombosis or endocarditis has been 100% for both AVR and MVR. In AVR group left ventricle mass, left ventricle mass index significantly decreased, when cardiac index and effective orifice area increased significantly during study period. Transvalvular gradient did not change. In MVR group transvalvular gradient, effective orifice area and cardiac index did not change. CONCLUSIONS: The valve was user friendly. The early results are very satisfactory. Echocardiography measurements after aortic valve replacement are showing very marked late postoperative remodelling of left ventricle. After mitral valve replacement there were exceptionally low transvalvular gradients, no left ventricle outflow tract obstruction.


Assuntos
Valva Aórtica/cirurgia , Bioprótese , Implante de Prótese de Valva Cardíaca/instrumentação , Próteses Valvulares Cardíacas , Ventrículos do Coração/fisiopatologia , Valva Mitral/cirurgia , Remodelação Ventricular/fisiologia , Idoso , Idoso de 80 Anos ou mais , Ecocardiografia , Feminino , Doenças das Valvas Cardíacas/diagnóstico por imagem , Doenças das Valvas Cardíacas/fisiopatologia , Doenças das Valvas Cardíacas/cirurgia , Ventrículos do Coração/diagnóstico por imagem , Humanos , Masculino , Pessoa de Meia-Idade , Desenho de Prótese , Estudos Retrospectivos , Preservação de Tecido , Resultado do Tratamento
20.
J Cardiovasc Surg (Torino) ; 41(1): 11-6, 2000 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-10836215

RESUMO

BACKGROUND: To evaluate the homeostasis of myocardium during simultaneous continuous retrograde and antegrade cardioplegia vs retrograde continuous cardioplegia. METHODS: 40 patients who underwent elective operation of coronary arteries bypass grafting were randomly assigned to 2 groups: group one consisted of 24 patients who received retrograde continuous blood cardioplegia; group two consisted of 16 patients who received simultaneous continuous ante/retrograde cardioplegia. The following measurements were taken: acidosis, oxygen content, oxygen extraction and oxygen consumption; they were taken before and after cross-clamp releasing from coronary sinus effluent and from arterial line. Incidence of low cardiac output, ventricular fibrillation, raised cardiac enzymes and ischemic changes on ECG was noted. RESULTS: In simultaneous group such parameters as acidosis, oxygen content, oxygen extraction and myocardial oxygen consumption recovered after cross-clamping and changes of their values were respectively: 0.0005, 0.87 ml/100 ml, 0.098 and 1.4 ml/min. The same parameters didn't recovered in retrograde group and changes were respectively: 0.05 - p=0.2; 3.7 ml/100 ml - p=0.006, 0.29 p=0.006 and 7.4 ml/min - p=0.03. These changes were significant between groups. CONCLUSIONS: Metabolic viability of myocardium measured with oxygen utilisation is better preserved with simultaneous antegrade and retrograde cardioplegia.


Assuntos
Soluções Cardioplégicas/administração & dosagem , Ponte de Artéria Coronária/métodos , Hipotermia Induzida/métodos , Adulto , Metabolismo Energético/fisiologia , Feminino , Humanos , Ácido Láctico/sangue , Masculino , Pessoa de Meia-Idade , Miocárdio/metabolismo , Oxigênio/sangue , Complicações Pós-Operatórias/etiologia
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