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1.
Environ Geochem Health ; 41(3): 1321-1338, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30446862

RESUMO

The Pacific oyster (Crassostrea gigas) is one of the world's most widespread bivalves and a suitable species for biomonitoring metals in coastal environments. In the present research, wild individuals were collected from an Argentinian estuary and the coastal beaches nearby. The concentrations of eight metals (Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn) were quantified in the soft tissues of the Pacific oyster. Among the metals, Cu, Fe and Zn reached the highest concentrations in the soft tissues over the rest of the elements. The results showed the highest values to be estuary related, with the beach site achieving the lowest values. These results possibly lie on the impact of human activities surrounding the estuary, as well as streams and rivers that outflow within it. Higher Cu and Zn levels, both port related, were mainly found toward the outer estuary. On the other hand, high levels of Cr, Fe and Mn were found toward the inner zone of the estuary, an area with sewage sludge from the cities located on the margins of the BBE. Regarding the potential risk to public health, Cu and Zn levels found in C. gigas were above national and international safety guidelines in 100% and 11% of the samples, respectively.


Assuntos
Crassostrea/química , Metais Pesados/análise , Poluentes Químicos da Água/análise , Animais , Monitoramento Ambiental/métodos , Estuários , Contaminação de Alimentos/análise , Rios , Frutos do Mar/análise
2.
Phys Rev Lett ; 121(6): 060503, 2018 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-30141644

RESUMO

The concept of parity describes the inversion symmetry of a system and is of fundamental relevance in the standard model, quantum information processing, and field theory. In quantum electrodynamics, parity is conserved and large field gradients are required to engineer the parity of the light-matter interaction operator. In this work, we engineer a potassiumlike artificial atom represented by a specifically designed superconducting flux qubit. We control the wave function parity of the artificial atom with an effective orbital momentum provided by a resonator. By irradiating the artificial atom with spatially shaped microwave fields, we select the interaction parity in situ. In this way, we observe dipole and quadrupole selection rules for single state transitions and induce transparency via longitudinal coupling. Our work advances the design of tunable artificial multilevel atoms to a new level, which is particularly promising with respect to quantum chemistry simulations with near-term superconducting circuits.

3.
Foodborne Pathog Dis ; 15(2): 94-100, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-29215297

RESUMO

Cow raw milk cheese is widely eaten in Brazil. These products may be contaminated with pathogenic bacteria. In this work, we investigated the presence of Escherichia coli in raw milk cheese from different States in Brazil. From 147 "Minas" cheese samples, 28 cheeses were positive for E. coli. Among 39 E. coli isolates of the cheeses, one was positive for eae and negative for bpfA and efa1/lifA using PCR, and so was classified as atypical Enteropathogenic E. coli (aEPEC). Two other isolates were positive for extraintestinal pathogenic E. coli (ExPEC) genes. The aEPEC isolate belongs to serogroup O127 and was classified in A phylogenetic group, and ExPEC isolates were found in O73:H12 (EC-2 strain) and O64474:H8 (EC-9 strain) serotype. This ExPEC belongs to A and C phylogenetic group, respectively. Most of E. coli strains belonged to Clermont phylogenetic groups A (28.2%), C, and E (23.1%). Six strains (15.4%) of E. coli were positive for group B1 and two (5.1%) for B2. E. coli isolates presented an aggregative (46.0%) and diffuse (12.6%) adherence pattern to HeLa cells, and the other isolates did not show adhesion (41.4%). Four E. coli isolates (10.3%) were shown to produce moderate biofilm. The antimicrobial resistance rate was tetracycline (25.6%), followed by ampicillin (17.9%), cefoxitin (7.7%), nalidixic acid (5.1%), and amoxicillin-clavulanic acid (2.6%). One strain was resistant to three antimicrobials (tetracycline, ampicillin, and nalidixic acid). The presence of these microorganisms, the O127 strain, and a new serogroup in Brazil is a potential risk for public health.


Assuntos
Queijo/microbiologia , Farmacorresistência Bacteriana Múltipla/genética , Escherichia coli Enteropatogênica/genética , Leite/microbiologia , Combinação Amoxicilina e Clavulanato de Potássio/farmacologia , Ampicilina/farmacologia , Animais , Antibacterianos/farmacologia , Aderência Bacteriana , Brasil , Cefoxitina/farmacologia , DNA Bacteriano/genética , DNA Bacteriano/isolamento & purificação , Escherichia coli Enteropatogênica/efeitos dos fármacos , Escherichia coli Enteropatogênica/isolamento & purificação , Contaminação de Alimentos , Microbiologia de Alimentos , Células HeLa , Humanos , Testes de Sensibilidade Microbiana , Ácido Nalidíxico/farmacologia , Pasteurização , Filogenia , Sorogrupo , Sorotipagem , Tetraciclina/farmacologia
4.
Phys Rev Lett ; 118(10): 103602, 2017 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-28339239

RESUMO

In experiments with superconducting quantum circuits, characterizing the photon statistics of propagating microwave fields is a fundamental task. We quantify the n^{2}+n photon number variance of thermal microwave photons emitted from a blackbody radiator for mean photon numbers, 0.05≲n≲1.5. We probe the fields using either correlation measurements or a transmon qubit coupled to a microwave resonator. Our experiments provide a precise quantitative characterization of weak microwave states and information on the noise emitted by a Josephson parametric amplifier.

5.
Mol Biol Rep ; 44(6): 455-461, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28993955

RESUMO

Gastrointestinal tract conditions are frequently associated with low bone mineral density and increased risk of fractures due to osteoporosis, the latter concerning particularly inflammatory bowel disease (IBD) patients. One of the candidate genes involved in osteoporosis is the transforming growth factor beta-1 (TGFB1) whose polymorphisms may be responsible for the development of this disease. The aim of this study was to analyse the frequency of TGFB1 polymorphic variants and determine the association between the c.29T>C TGFB1 polymorphism, and bone mineral density and fractures in IBD patients. The study subjects included 198 IBD patients [100 suffering from Crohn's disease (CD) and 98 from ulcerative colitis (UC)] and 41 healthy volunteers as a control group. Densitometric bone measurements were obtained using dual energy X-ray absorptiometry. The TGFB1 genotyping was conducted using restriction fragments length polymorphism. We conducted an analysis of genotype distribution's concordance with Hardy-Weinberg equilibrium. We found statistically significant differences in lumbar spine (L2-L4) and femoral neck BMD and T-scores between CD, UC and control subgroups. The distribution of TGFB1 polymorphic variants among CD and UC patients was concordant with Hardy-Weinberg equilibrium. There were no statistically significant differences in densitometric parameters (lumbar spine and femoral neck BMD, T-score, and Z-score) between carriers of different TGFB1 polymorphisms among IBD (CD and UC) patients nor among controls. We have found no statistically significant differences in the prevalence of low-energy fractures between groups of different TGFB1 polymorphic variant carriers. The allele dose effect, recessive effect and dominant effect analysis did not show an association between low-energy fractures and the TGFB1 polymorphisms among CD and UC patients. We have not observed an association between the c.29T>C TGFB1 polymorphic variant and the bone mineral density within the cancellous and cortical bones (L2-L4 and femoral neck, respectively), or the occurrence of fractures among the IBD patients and their family members.


Assuntos
Doenças Inflamatórias Intestinais/genética , Fator de Crescimento Transformador beta1/genética , Adulto , Alelos , Densidade Óssea/genética , Colite Ulcerativa/genética , Doença de Crohn/genética , Estudos Transversais , Feminino , Fraturas Ósseas/genética , Predisposição Genética para Doença , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Osteoporose/genética , Osteoporose/metabolismo , Polimorfismo de Nucleotídeo Único , Fatores de Risco , Fator de Crescimento Transformador beta1/metabolismo
6.
Phys Rev Lett ; 117(2): 020502, 2016 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-27447495

RESUMO

Displacement of propagating quantum states of light is a fundamental operation for quantum communication. It enables fundamental studies on macroscopic quantum coherence and plays an important role in quantum teleportation protocols with continuous variables. In our experiments, we have successfully implemented this operation for propagating squeezed microwave states. We demonstrate that, even for strong displacement amplitudes, there is no degradation of the squeezing level in the reconstructed quantum states. Furthermore, we confirm that path entanglement generated by using displaced squeezed states remains constant over a wide range of the displacement power.

7.
ESMO Open ; 9(7): 103632, 2024 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-38970840

RESUMO

BACKGROUND: Data regarding the clinical outcome of patients with immune checkpoint inhibitor (ICI)-induced colitis are scant. We aimed to describe the 12-month clinical outcome of patients with ICI-induced colitis. MATERIALS AND METHODS: This was a retrospective, European, multicentre study. Endoscopy/histology-proven ICI-induced colitis patients were enrolled. The 12-month clinical remission rate, defined as a Common Terminology Criteria for Adverse Events diarrhoea grade of 0-1, and the correlates of 12-month remission were assessed. RESULTS: Ninety-six patients [male:female ratio 1.5:1; median age 65 years, interquartile range (IQR) 55.5-71.5 years] were included. Lung cancer (41, 42.7%) and melanoma (30, 31.2%) were the most common cancers. ICI-related gastrointestinal symptoms occurred at a median time of 4 months (IQR 2-7 months). An inflammatory bowel disease (IBD)-like pattern was present in 74 patients (77.1%) [35 (47.3%) ulcerative colitis (UC)-like, 11 (14.9%) Crohn's disease (CD)-like, 28 (37.8%) IBD-like unclassified], while microscopic colitis was present in 19 patients (19.8%). As a first line, systemic steroids were the most prescribed drugs (65, 67.7%). The 12-month clinical remission rate was 47.7 per 100 person-years [95% confidence interval (CI) 33.5-67.8). ICI was discontinued due to colitis in 66 patients (79.5%). A CD-like pattern was associated with remission failure (hazard ratio 3.84, 95% CI 1.16-12.69). Having histopathological signs of microscopic colitis (P = 0.049) and microscopic versus UC-/CD-like colitis (P = 0.014) were associated with a better outcome. Discontinuing the ICI was not related to the 12-month remission (P = 0.483). Four patients (3.1%) died from ICI-induced colitis. CONCLUSIONS: Patients with IBD-like colitis may need an early and more aggressive treatment. Future studies should focus on how to improve long-term clinical outcomes.

8.
Phys Rev Lett ; 109(25): 250502, 2012 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-23368439

RESUMO

Path entanglement constitutes an essential resource in quantum information and communication protocols. Here, we demonstrate frequency-degenerate entanglement between continuous-variable quantum microwaves propagating along two spatially separated paths. We combine a squeezed and a vacuum state using a microwave beam splitter. Via correlation measurements, we detect and quantify the path entanglement contained in the beam splitter output state. Our experiments open the avenue to quantum teleportation, quantum communication, or quantum radar with continuous variables at microwave frequencies.

9.
Int J Radiat Biol ; 97(sup1): S6-S9, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-32909884

RESUMO

Radiation Biodosimetry is a continually developing clinical diagnostic field, which focuses on biological markers that proportionally change in relationship to the amount of ionizing radiation absorbed. Examples of host marker response include changes in white cell count, specific proteins in circulation, RNAs in white blood cells, or chromosome fidelity in affected lymphocytes. Measurements of radiation biomarkers correlate with the approximate radiation dose absorbed and indirectly provide an assessment of the likelihood of developing acute radiation syndrome. The aim of this review is to summarize four biodosimetry programs that are in advanced development, later pipeline stages with funding from the Biomedical Advanced Research and Development Authority (BARDA), an agency under the Assistant Secretary for Preparedness and Response (ASPR) in the U.S. Department of Health and Human Services (HHS). With BARDA financial support, biodosimetry diagnostic assays in development will inform patient management, improve health and psychosocial outcomes, and save lives after a nuclear disaster. These tests include an SRI International developed rapid on-site screening test requiring only a finger stick of blood to triage those who have received little or no radiation from those who have received clinically significant levels of radiation and need further immediate patient management. In addition, multiple laboratory-based, high-throughput quantitative tests, currently under development by MRIGlobal, DxTerity, and ASELL, will more accurately define dose levels and possibly predict cellular and organ-damage and other longer-term effects of radiation. In the future, when clinical and analytical validation of these assays is complete, the data is reviewed by the FDA, and agency use status is obtained, rapid triage and laboratory-based biodosimetry test results will enable emergency medical teams to do the most good for the largest number of people after a nuclear blast.


Assuntos
Síndrome Aguda da Radiação , Liberação Nociva de Radioativos , Humanos , Saúde Pública , Radiometria/métodos , Triagem/métodos
10.
J Cell Biol ; 138(6): 1181-92, 1997 Sep 22.
Artigo em Inglês | MEDLINE | ID: mdl-9298975

RESUMO

Heterogeneous nuclear ribonucleoprotein (hnRNP) A1 is an abundant nuclear protein that plays an important role in pre-mRNA processing and mRNA export from the nucleus. A1 shuttles rapidly between the nucleus and the cytoplasm, and a 38-amino acid domain, M9, serves as the bidirectional transport signal of A1. Recently, a 90-kD protein, transportin, was identified as the mediator of A1 nuclear import. In this study, we show that transportin mediates the nuclear import of additional hnRNP proteins, including hnRNP F. We have also isolated and sequenced a novel transportin homolog, transportin2, which may differ from transportin1 in its substrate specificity. Immunostaining shows that transportin1 is localized both in the cytoplasm and the nucleoplasm, and nuclear rim staining is also observed. The nuclear localization of A1 is dependent on ongoing RNA polymerase II transcription. Interestingly, a pyruvate kinase-M9 fusion, which normally localizes in the nucleus, also accumulates in the cytoplasm when RNA polymerase II is inhibited. Thus, M9 itself is a specific sensor for transcription-dependent nuclear transport. Transportin1-A1 complexes can be isolated from the cytoplasm and the nucleoplasm, but transportin1 is not detectable in hnRNP complexes. RanGTP causes dissociation of A1-transportin1 complexes in vitro. Thus, it is likely that after nuclear import, A1 dissociates from transportin1 by RanGTP and becomes incorporated into hnRNP complexes, where A1 functions in pre-mRNA processing.


Assuntos
Núcleo Celular/enzimologia , Ribonucleoproteínas Nucleares Heterogêneas Grupo A-B , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Receptores Citoplasmáticos e Nucleares/genética , Receptores Citoplasmáticos e Nucleares/metabolismo , Ribonucleoproteínas/metabolismo , Animais , Anticorpos Monoclonais , Especificidade de Anticorpos , Transporte Biológico/fisiologia , Núcleo Celular/química , Citoplasma/química , Citoplasma/metabolismo , Proteínas de Ligação ao GTP/metabolismo , Proteínas de Ligação ao GTP/farmacologia , Células HeLa , Ribonucleoproteína Nuclear Heterogênea A1 , Ribonucleoproteínas Nucleares Heterogêneas Grupo F-H , Ribonucleoproteínas Nucleares Heterogêneas , Humanos , Carioferinas , Camundongos , Camundongos Endogâmicos BALB C , Dados de Sequência Molecular , Proteínas Nucleares/análise , Proteínas Nucleares/química , Proteínas Nucleares/imunologia , Proteínas Nucleares/farmacologia , Piruvato Quinase/metabolismo , Precursores de RNA/metabolismo , Receptores Citoplasmáticos e Nucleares/química , Receptores Citoplasmáticos e Nucleares/imunologia , Homologia de Sequência de Aminoácidos , Especificidade por Substrato , Transcrição Gênica/fisiologia , beta Carioferinas , Proteína ran de Ligação ao GTP
11.
Science ; 233(4763): 569-71, 1986 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-3523758

RESUMO

In Trypanosomatidae the messenger RNA's (mRNA's) that code for the variant surface glycoproteins (VSG's), tubulins, calmodulin, and at least a subset of other proteins contain a common 35-nucleotide leader sequence at their 5' ends. Hybrid-arrested in vitro translation has been used to show that all mRNA's in both African and South American trypanosomes contain this 35-nucleotide sequence. Oligonucleotides complementary to this sequence blocked translation of all trypanosome mRNA's in a rabbit reticulocyte lysate system, but did not inhibit translation of mRNA's from other organisms lacking this sequence. An oligonucleotide complementary to the VSG mRNA downstream from the spliced leader sequence arrested only VSG synthesis. Thus, the 35-nucleotide leader sequence is a general feature of all trypanosome mRNA's. The high specificity of oligonucleotides complementary to the spliced leader for their target sequence suggests that analogues permeable to the cell membrane may be useful in the treatment of trypanosomal infections.


Assuntos
Sinais Direcionadores de Proteínas/genética , RNA Mensageiro/genética , Trypanosoma/genética , Sequência de Bases , Biossíntese de Proteínas , Trypanosoma brucei brucei/genética , Trypanosoma cruzi/genética
12.
Cardiovasc Res ; 73(1): 111-9, 2007 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-17129578

RESUMO

OBJECTIVE: Members of the classical transient receptor potential protein (TRPC) family are considered as key components of phospholipase C (PLC)-dependent Ca2+ signaling. Previous results obtained in the HEK 293 expression system suggested a physical and functional coupling of TRPC3 to the cardiac-type Na+/Ca2+ exchanger, NCX1 (sodium calcium exchanger 1). This study was designed to test for expression of TRPC3 (transient receptor potential channel 3) and for the existence of a native TRPC3/NCX1 signaling complex in rat cardiac myocytes. METHODS: Protein expression and cellular distribution were determined by Western blot and immunocytochemistry. Protein-protein interactions were investigated by reciprocal co-immunoprecipitation and glutathione S-transferase (GST)-pulldown experiments. Recruitment of protein complexes into the plasma membrane was assayed by surface biotinylation. The functional role of TRPC3 was investigated by fluorimetric recording of angiotensin II-induced calcium signals employing a dominant negative knockdown strategy. RESULTS: TRPC3 immunoreactivity was observed in surface plasma membrane regions and in an intracellular membrane system. Co-immunolabeling of TRPC3 and NCX1 indicated significant co-localization of the two proteins. Both co-immunoprecipitation and GST-pulldown experiments demonstrated association of TRPC3 with NCX1. PLC stimulation was found to trigger NCX-mediated Ca2+ entry, which was dependent on TRPC3-mediated Na+ loading of myocytes. This NCX-mediated Ca2+ signaling was significantly suppressed by expression of a dominant negative fragment of TRPC3. PLC stimulation was associated with increased membrane presentation of both TRPC3 and NCX1. CONCLUSION: These results suggest a PLC-dependent recruitment of a TRPC3-NCX1 complex into the plasma membrane as a pivotal mechanism for the control of cardiac Ca2+ homeostasis.


Assuntos
Cálcio/metabolismo , Miócitos Cardíacos/metabolismo , Transdução de Sinais/fisiologia , Trocador de Sódio e Cálcio/metabolismo , Canais de Cátion TRPC/metabolismo , Fosfolipases Tipo C/metabolismo , Animais , Linhagem Celular , Membrana Celular/metabolismo , Células Cultivadas , Homeostase , Humanos , Imuno-Histoquímica/métodos , Imunoprecipitação/métodos , Microscopia Confocal , Miócitos Cardíacos/química , Ratos , Ratos Sprague-Dawley , Canais de Cátion TRPC/análise , Canais de Cátion TRPC/genética , Transfecção
13.
Sci Rep ; 8(1): 6416, 2018 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-29686396

RESUMO

Two-mode squeezing is a fascinating example of quantum entanglement manifested in cross-correlations of non-commuting observables between two subsystems. At the same time, these subsystems themselves may contain no quantum signatures in their self-correlations. These properties make two-mode squeezed (TMS) states an ideal resource for applications in quantum communication. Here, we generate propagating microwave TMS states by a beam splitter distributing single mode squeezing emitted from distinct Josephson parametric amplifiers along two output paths. We experimentally study the fundamental dephasing process of quantum cross-correlations in continuous-variable propagating TMS microwave states and accurately describe it with a theory model. In this way, we gain the insight into finite-time entanglement limits and predict high fidelities for benchmark quantum communication protocols such as remote state preparation and quantum teleportation.

14.
Handb Exp Pharmacol ; (179): 77-92, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17217051

RESUMO

TRPC3 represents one of the first identified mammalian relatives of the Drosophila trp gene product. Despite intensive biochemical and biophysical characterization as well as numerous attempts to uncover its physiological role in native cell systems, this channel protein still represents one of the most enigmatic members of the transient receptor potential (TRP) superfamily. TRPC3 is significantly expressed in brain and heart and likely to play a role in both non-excitable as well as excitable cells, being potentially involved in a wide spectrum of Ca2+ signalling mechanisms. Its ability to associate with a variety of partner proteins apparently enables TRPC3 to form different cation channels in native cells. TRPC3 cation channels display unique gating and regulatory properties that allow for recognition and integration of multiple input stimuli including lipid mediators and cellular Ca2+ gradients as well as redox signals. The physiological/pathophysiological functions of this highly versatile cation channel protein are as yet barely delineated. Here we summarize current knowledge on properties and possible signalling functions of TRPC3 and discuss the potential biological relevance of this signalling molecule.


Assuntos
Transdução de Sinais/genética , Transdução de Sinais/fisiologia , Canais de Cátion TRPC/genética , Canais de Cátion TRPC/fisiologia , Animais , Expressão Gênica/fisiologia , Humanos , Ativação do Canal Iônico/genética , Ativação do Canal Iônico/fisiologia , Fosforilação , Frações Subcelulares/fisiologia
15.
J Physiol Pharmacol ; 68(5): 757-764, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-29375051

RESUMO

Finding genetic predictors of osteoporosis and fractures in patients with inflammatory bowel disease (IBD) may provide incentives for non-pharmacological actions and so improve the long-term prognosis of the patients. We analysed the incidence of BMP2 570A>T polymorphic variants and their association with bone mineral density (BMD) and the incidence of fractures in patients with IBD. The study comprised 198 IBD patients (100 with Crohn's disease (CD), and 98 with ulcerative colitis, (UC)) and 41 healthy controls. Bone densitometric analysis was carried out using the DXA method. The 570A>T polymorphisms in the BMP2 gene were genotyped using RFLP. We found significant differences in the BMD and T-scores of the lumbar spine (L2-L4) and femoral neck between the three groups. In controls and CD patients, the highest L2-L4 BMD was found in carriers of the AA variant of the BMP2 gene, while among UC patients it was the case of TT carriers. In both femoral neck and lumbar spine among UC patients, the highest BMD was observed in carriers of the TT variant of the BMP2 gene. Among patients with CD and in the control group, the highest L2-L4 BMD was found in carriers of the AA variant, whereas in UC patients, it was the case of TT homozygotes. Within the femoral neck, there were no significant differences in BMD for the carriers of individual variants of BMP2 gene polymorphism. We conclude that the 570A>T polymorphism of the BMP2 gene, no statistically significant relationship was observed between the polymorphic variant and bone mineral density or the incidence of fractures in IBD patients.


Assuntos
Densidade Óssea/genética , Proteína Morfogenética Óssea 2/genética , Doenças Inflamatórias Intestinais/genética , Polimorfismo Genético/genética , Adulto , Estudos Transversais , Feminino , Variação Genética/genética , Humanos , Doenças Inflamatórias Intestinais/diagnóstico , Masculino , Pessoa de Meia-Idade , Adulto Jovem
16.
J Clin Oncol ; 7(4): 515-26, 1989 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-2647915

RESUMO

Autologous bone marrow transplantation (AuBMT) is in clinical trial for patients with metastatic solid tumors, particularly breast cancer. This review deals with the potential of this approach. AuBMT is curative for the leukemias and lymphomas. Curative cancer chemotherapy has, almost without exception, required combinations of agents wherein dose was well maintained. However, curative chemotherapy strategies for the hematologic neoplasms have not proven successful for the common solid tumors. An important exception is that standard adjuvant chemotherapy can "cure" some micrometastatic tumors. Preclinical studies indicate the effectiveness of alkylating agents in terms of maintained dose effect through multiple logs of tumor cell kill; difficulty in developing drug resistance; general lack of cross resistance; and synergy for alkylating agents used in combination. There is an increasingly effective experimental basis for the construct of intensification regimens employing combinations of alkylating agents. Differing nonmyelosuppressive toxicity for alkylating agents provides a basis for maintaining dose when employed in combination in the autologous marrow situation. The aforementioned studies and cytokinetic analyses of combined intensive alkylating agent therapy for breast cancer support the potential of this approach. Clinical trials indicate a high response rate in refractory breast cancer. Trials involving induction chemotherapy followed by combined alkylating agent intensification have produced substantial complete remission rates. The duration of response has, in most studies, been short. This approach is associated with major toxicity, including mortality, and is expensive. Experimental and preliminary clinical evidence as marshalled in this review indicate that this is a promising area for therapeutic research.


Assuntos
Transplante de Medula Óssea , Neoplasias da Mama/cirurgia , Antineoplásicos/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias da Mama/tratamento farmacológico , Feminino , Humanos , Metástase Neoplásica , Indução de Remissão
17.
Thyroid ; 15(10): 1169-75, 2005 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-16279851

RESUMO

Thyroid ultrasound is used in the routine clinical assessment and the follow-up of thyroid disorders. The follow- up of patients with thyroid nodules is mostly based on thyroid nodule volume determinations performed by different observers. However, for the judgment of treatment effects there is uncertainty about the interobserver variation of thyroid nodule volume measurements by ultrasound because there are no prospective blinded studies available comparing the interobserver variation in thyroid nodule volume measurement. The aim of our study was therefore to determine the variation of thyroid nodule volume determinations for different observers. We conducted a prospective blinded trial. Our study population consisted of 42 probands (8 men, 34 women) with an uniform distribution of thyroid nodule sizes (25 uninodular and 17 multinodular thyroid glands). We compared the results of 3 ultrasonographers with certified experience in thyroid ultrasound. The interobserver variation for the determination of thyroid nodule volume (n = 38) was 48.96% for the ellipsoid method and 48.64% for the planimetric method. The interobserver variation for determining thyroid volume (n = 40) was 23.69% for the ellipsoid method and 17.82% for the planimetric method. A regression analysis revealed that the probability for the identification of the same nodule in nodular thyroids by all sonographers is 90%, if the nodule is at least 15mm in greatest diameter. Future investigations should not describe changes in nodule volume less than 50% as therapy effects because only volume changes of at least 49% or more can be interpreted as nodule shrinkage or growth. Reporting of nodule volume modification 50% or more and lack of information for ultrasound procedures introduce a bias in studies evaluating the effects of nodule treatments. The clinical interpretation of a shrinking/growing thyroid nodule based on volume determinations by ultrasound is not well established because it is difficult to reproduce a two-dimensional image plane for follow-up studies.


Assuntos
Nódulo da Glândula Tireoide/diagnóstico por imagem , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Variações Dependentes do Observador , Estudos Prospectivos , Nódulo da Glândula Tireoide/epidemiologia , Nódulo da Glândula Tireoide/patologia , Ultrassonografia/métodos
18.
Leukemia ; 11(1): 73-85, 1997 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-9001421

RESUMO

Raised intracellular cyclic AMP (cAMP) has been demonstrated to exert an antiproliferative effect in myeloid cells. How the antiproliferative activity of cAMP is exerted in p210 BCR-ABL transformed myeloid cells was the subject of this investigation. It was hypothesized that cyclin dependent kinase 4, cdk4, might be a critical target enzyme to affect the related events of c-myc transcription and progression through G1 phase of the cell cycle within cells transformed by p210 BCR-ABL, and further, that cdk4 might be downregulated by cAMP to inhibit proliferation. In order to investigate the regulatory role of cdk4, synchronized cells were studied. In p210 BCR-ABL transformed cells transiting early G1 phase, treatment with a cAMP analogue led to inhibition of cyclin D1 synthesis, and marked reduction of cdk4 kinase activity. Within cells in which cdk4 was inhibited by cAMP, there was augmented interaction of E2F1 with the retinoblastoma protein, pRb in a nuclear matrix-associated cell fraction. As a result of E2F1 sequestration, raised intracellular cAMP was found to inhibit c-myc transcription in p210 BCR-ABL transformed myeloid cells synchronously transiting the early G1 phase of the cell cycle. A target of this transcriptional suppression exerted by cAMP was the E2F site of the c-myc P2 promoter. On the other hand, cyclin D1 content was not reduced by cAMP in these cells when it was applied at a later cell cycle stage at the interface between G1 and S. Corresponding to lack of cyclin D1 inhibition in these later G1-to-S phase cells, cdk4 activity was only modestly suppressed, and c-myc mRNA expression was also inhibited to a lesser degree. These studies show that Rb interaction with E2F1 is regulated by cdk4 and cyclin D1 within p210 BCR-ABL transformed leukemia cells in early G1 phase of the cell cycle. In this context, both cyclin D1 and cdk4 are subject to the level of intracellular cAMP. This interaction between Rb and E2F1, which is subject to the level of cAMP, is critical to transcriptional control of c-myc. Further, pRb regulation of E2F activity affects cellular potential for G1-S phase transition in p210 BCR-ABL transformed myeloid cells, in part, via its effect on c-myc transcription.


Assuntos
AMP Cíclico/fisiologia , Quinases Ciclina-Dependentes/metabolismo , Ciclinas/metabolismo , Fase G1/fisiologia , Proteínas Oncogênicas/metabolismo , Proteínas Proto-Oncogênicas c-myc/metabolismo , Proteínas Proto-Oncogênicas , RNA Mensageiro/metabolismo , Animais , Linhagem Celular Transformada , AMP Cíclico/análogos & derivados , AMP Cíclico/metabolismo , AMP Cíclico/farmacologia , Ciclina D1 , Quinase 4 Dependente de Ciclina , Proteínas de Fusão bcr-abl , Fase G1/efeitos dos fármacos , Luciferases/metabolismo , Camundongos , Fosforilação , Proteínas Proto-Oncogênicas c-myc/genética , Fase S/efeitos dos fármacos , Fase S/fisiologia , Ativação Transcricional
19.
Exp Hematol ; 24(10): 1215-24, 1996 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-8765497

RESUMO

In addition to possessing multilineage differentiation and self-renewal capabilities, pluripotent hematopoietic stem cells are believed to be mitotically quiescent and metabolically inactive. Fractions of human bone marrow (BM) CD34+ cells can be further enriched for primitive hematopoietic progenitor cells (HPC) by using a number of cell-surface markers. All of these fractions, however, contain cells that are still heterogeneous as far as their metabolic and mitotic activities are concerned. We therefore used Hoechst 33342 (Hst) to identify quiescent cells and Rhodamine 123 (Rh123) to identify metabolically inactive cells. CD34+HstdimRh123dim (CD34+d/d) and CD34+HstbrightRh123bright (CD34+b/b) cells were isolated by flow cytometry to examine the hematopoietic functions of mitotically and metabolically homogeneous progenitors. Cell-cycle status, progenitor cell content, maintenance of in vitro hematopoiesis, and long-term hematopoietic culture-initiating cell (LTHC-IC) content of CD34+d/d and CD34+b/b cells were compared with CD34+HLA-DR- cells, a well-defined phenotype of primitive HPC. Whereas 99.2 +/- 0.5% of freshly isolated CD34+d/d cells were in G0/G1 phase of the cell cycle, only 74.4 +/- 11.5% of CD34+b/b and 75.6 +/- 1.1% of CD34+HLA-DR- cells were in G0/G1. The number of multipotential progenitors (colony-forming units-granulocyte/erythroid/ macrophage/megakaryocyte [CFU-GEMM]) detected in CD34+d/d cells was twice that observed in CD34+HLA-DR- cells and eight times that in CD34+b/b cells. In stromal cell-free long-term cultures maintained for 10 weeks, production of assayable progenitors in cultures initiated with CD34+d/d cells exceeded that detected in CD34+HLA-DR- cultures by more than three-fold. Only in CD34+d/d cultures were high proliferative potential colony-forming cell (HPP-CFC)-derived colonies detected over a period of 6 weeks. Limiting dilution analysis revealed that the frequency of LTHC-IC was highest among CD34+d/d cells (7.2 +/- 3.3%), followed by a frequency of 4.5 +/- 4.8% for CD34+HLA-DR- cells and 2.2 +/- 3.5% for CD34+b/b cells. The primitive nature of HPC identified by CD34, Hst, and Rh123 was confirmed by the ability of as few as 200 murine marrow cells isolated by this technique to radioprotect and fully reconstitute lethally irradiated recipients. These results indicate that Hst and Rh123 staining can be used in combination with CD34 immunofluorescence to isolate a quiescent subpopulation of human primitive hematopoietic progenitor cells. Cells isolated by this technique appear to have functional properties associated with stem cells, suggesting that they may be ideal candidates for studies requiring primitive HPC, such as ex vivo expansion and somatic gene therapy.


Assuntos
Células da Medula Óssea , Transplante de Células-Tronco Hematopoéticas , Células-Tronco Hematopoéticas/citologia , Adulto , Animais , Antígenos CD/análise , Antígenos CD34/análise , Benzimidazóis , Ciclo Celular , Diferenciação Celular , Separação Celular/métodos , Quimera , Técnicas de Cultura/métodos , Citometria de Fluxo/métodos , Corantes Fluorescentes , Hemoglobinas , Humanos , Cinética , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos , Rodamina 123 , Rodaminas , Fatores de Tempo
20.
N Z Vet J ; 63(3): 153-7, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25371291

RESUMO

AIM: To assess the effect of analgesia at disbudding on weight gain and milk intake of dairy calves. METHODS: Four disbudding protocols were used on 3- to 6-week-old Friesian-Jersey calves. Farm staff disbudded 101 calves without sedation or local analgesia, of which 51 received 20 mg meloxicam S/C. Veterinary staff disbudded 101 calves with sedation and local analgesia, of which 51 also received 20 mg meloxicam S/C. Calves were weighed before disbudding, 15 and 30 days later, and individual milk consumption was recorded for 11 days. Daily weight gain and milk consumption were analysed using mixed models and ANOVA. RESULTS: From disbudding (Day 0) to Day 15 farmer-disbudded calves receiving meloxicam grew faster (0.65 kg/day) than calves without meloxicam (0.55 kg/day; p=0.011), but an interaction between operator and meloxicam treatment (p=0.056) meant that meloxicam treatment did not increase growth rates in veterinary-disbudded calves (0.63 vs. 0.64 kg/day; p=0.872). From Days 16-30 there was no significant effect of meloxicam on growth rate, but veterinarian-disbudded calves grew faster (0.76 kg/day) than farmer-disbudded calves (0.66 kg/day; p=0.034). Overall, for the first 30 days after disbudding, if meloxicam was not used', veterinarian-disbudded calves grew faster than farmer-disbudded calves (p=0.002). However if meloxicam was used at disbudding there was no difference in growth rate between veterinarian- and farmer-disbudded calves (p=0.878). Mean cumulative milk consumption for the 11 days after disbudding was greater for calves disbudded by veterinary staff than by farm staff (p<0.001), but there was no effect of meloxicam treatment (p=0.618) and no interaction with operator (p=0.86) on cumulative milk consumption. CONCLUSIONS: Three to 6-week-old dairy calves disbudded by farm staff with no analgesia grew significantly slower over the next 15 days than farmer-disbudded calves given meloxicam, and slower over the next 30 days than veterinarian-disbudded calves given xylazine and lignocaine. However addition of meloxicam to the latter protocol had no effect on growth rate. Milk intake was significantly higher for 11 days for veterinarian- compared with farmer-disbudded calves. CLINICAL RELEVANCE: This study adds to the evidence that analgesia during disbudding is beneficial for calf productivity as well as calf welfare.


Assuntos
Analgesia/veterinária , Bovinos , Ingestão de Alimentos/efeitos dos fármacos , Cornos/cirurgia , Aumento de Peso/efeitos dos fármacos , Anestésicos Locais/administração & dosagem , Anestésicos Locais/farmacologia , Criação de Animais Domésticos/métodos , Animais , Anti-Inflamatórios não Esteroides/administração & dosagem , Anti-Inflamatórios não Esteroides/farmacologia , Hipnóticos e Sedativos/administração & dosagem , Hipnóticos e Sedativos/farmacologia , Lidocaína/administração & dosagem , Lidocaína/farmacologia , Meloxicam , Dor/prevenção & controle , Dor/veterinária , Tiazinas/administração & dosagem , Tiazinas/farmacologia , Tiazóis/administração & dosagem , Tiazóis/farmacologia , Xilazina/administração & dosagem , Xilazina/farmacologia
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