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1.
Ann Oncol ; 29(4): 973-978, 2018 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-29390048

RESUMO

Background: The combination of intermediate-dose cytarabine plus mitoxantrone (IMA) can induce high complete remission rates with acceptable toxicity in elderly patients with acute myeloid leukemia (AML). We present the final results of a randomized-controlled trial comparing IMA with the standard 7 + 3 induction regimen consisting of continuous infusion cytarabine plus daunorubicin (DA). Patients and methods: Patients with newly diagnosed AML >60 years were randomized to receive either intermediate-dose cytarabine (1000 mg/m2 twice daily on days 1, 3, 5, 7) plus mitoxantrone (10 mg/m2 days 1-3) (IMA) or standard induction therapy with cytarabine (100 mg/m2 continuously days 1-7) plus daunorubicin (45 mg/m2 days 3-5) (DA). Patients in complete remission after DA received intermediate-dose cytarabine plus amsacrine as consolidation treatment, whereas patients after IMA were consolidated with standard-dose cytarabine plus mitoxantrone. Results: Between February 2005 and October 2009, 485 patients were randomized; 241 for treatment arm DA and 244 for IMA; 76% of patients were >65 years. The complete response rate after DA was 39% [95% confidence interval (95% CI): 33-45] versus 55% (95% CI: 49-61) after IMA (odds ratio 1.89, P = 0.001). The 6-week early-death rate was 14% in both arms. Relapse-free survival curves were superimposable in the first year, but separated afterwards, resulting in 3-year relapse-free survival rates of 29% versus 14% in the DA versus IMA arms, respectively (P = 0.042). The median overall survival was 10 months in both arms (P = 0.513). Conclusion: The dose escalation of cytarabine in induction therapy lead to improved remission rates in the elderly AML patients. This did not translate into a survival advantage, most likely due to differences in consolidation treatment. Thus, effective consolidation strategies need to be further explored. In combination with an effective consolidation strategy, the use of intermediate-dose cytarabine in induction may improve curative treatment for elderly AML patients.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Citarabina/administração & dosagem , Daunorrubicina/administração & dosagem , Leucemia Mieloide Aguda/tratamento farmacológico , Mitoxantrona/administração & dosagem , Idoso , Idoso de 80 Anos ou mais , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Citarabina/efeitos adversos , Daunorrubicina/efeitos adversos , Relação Dose-Resposta a Droga , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Mitoxantrona/efeitos adversos , Indução de Remissão , Análise de Sobrevida
2.
Klin Padiatr ; 226(1): 13-8, 2014 Jan.
Artigo em Alemão | MEDLINE | ID: mdl-24435790

RESUMO

BACKGROUND: Vaccination with 2 doses of > 95% of the population is necessary to eliminate measles. In Switzerland and especially in the central part, vaccine coverage is low (2006: 65%). This led 2006-2009 to a measles epidemic with thousands of cases and high costs. One death was noted in a formerly healthy 12 year old girl. PATIENTS AND METHODS: All measles cases, either hospitalized or reported to the authority, in the canton Lucerne between 2006 and 2009 were included. Course, complications, immunization rates and costs of the hospitalized children were analyzed. RESULTS: A total of 1 041 cases of measles were recorded; 758 (73%) were children < 16 years of age. 56 (6%) of the patients were admitted to hospital; half of them were children (n=26, admission rate 3.4%). Main complications were pneumonia with oxygen requirement (n=19), bacterial infections of the base of the skull (n=2) and acute measles encephalitis (n=3). One child each developed acute appendicitis and diabetes mellitus type 1. No death was noted. Median hospitalisation costs were 18 780 CHF. The surveillance system was incomplete: Every third admitted child was not reported to the authority. CONCLUSION: Due to low vaccine coverage measles still account for epidemics with high morbidity and extensive costs. Instant reporting of all cases is crucial for disease control. Early identification of persons at risk allows timely immunization. Switzerland will remain of central importance to eliminate measles in Europe by 2015.


Assuntos
Países Desenvolvidos , Epidemias/economia , Epidemias/estatística & dados numéricos , Custos de Cuidados de Saúde/estatística & dados numéricos , Sarampo/economia , Sarampo/mortalidade , Adolescente , Criança , Pré-Escolar , Estudos Transversais , Notificação de Doenças , Feminino , Hospitalização/economia , Hospitalização/estatística & dados numéricos , Hospitais Pediátricos/economia , Hospitais Pediátricos/estatística & dados numéricos , Humanos , Imunização Secundária/estatística & dados numéricos , Lactente , Masculino , Vacinação em Massa/estatística & dados numéricos , Sarampo/complicações , Sarampo/prevenção & controle , Vacina contra Sarampo/administração & dosagem , Estudos Retrospectivos , Análise de Sobrevida , Suíça , Revisão da Utilização de Recursos de Saúde/estatística & dados numéricos
3.
Br J Cancer ; 108(2): 265-70, 2013 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-23329236

RESUMO

BACKGROUND: This study was designed to compare cisplatin/docetaxel with oxaliplatin/docetaxel in patients with advanced and metastatic non-small lung cancer as a first-line treatment. METHODS: Patients were randomly assigned to receive either cisplatin 75 mg m(-2) and docetaxel 75 mg m(-2) every 3 weeks or oxaliplatin 85 mg m(-2) and docetaxel 50 mg m(-2) every 2 weeks. The primary end point was response rate, and secondary end points were toxicity, time to progression and overall survival. RESULTS: A total of 88 patients (median age: 65 (39-86) years; stage IV: 93%) were randomly assigned. Response rate (complete and partial response) was 47% (95% CI: 33-61%) in the cisplatin/docetaxel arm and 28% (95% CI: 17-43%) in the oxaliplatin/docetaxel arm (P=0.118). There was no significant difference in time to progression (6.3 vs 4.9 months, P=0.111) and median overall survival (11.6 vs 7.0 months, P=0.102) with cisplatin/docetaxel vs oxaliplatin/docetaxel, although slight trends favouring cisplatin were seen. Oxaliplatin/docetaxel was associated with significantly less (any grade) renal toxicity (56% vs 11%), any grade fatigue (81% vs 59%), complete alopecia (76% vs 27%), any grade leukopenia (84% vs 61%) and grade 3/4 leukopenia (44% vs 14%) and neutropenia (56% vs 27%). CONCLUSION: Oxaliplatin/docetaxel has activity in metastatic non-small cell lung cancer, but it seems to be inferior to cisplatin/docetaxel.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Cisplatino/administração & dosagem , Neoplasias Pulmonares/tratamento farmacológico , Compostos Organoplatínicos/administração & dosagem , Taxoides/administração & dosagem , Adulto , Idoso , Idoso de 80 Anos ou mais , Anticorpos Monoclonais Humanizados/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Bevacizumab , Carcinoma Pulmonar de Células não Pequenas/mortalidade , Cisplatino/efeitos adversos , Docetaxel , Esquema de Medicação , Feminino , Humanos , Neoplasias Pulmonares/mortalidade , Masculino , Pessoa de Meia-Idade , Compostos Organoplatínicos/efeitos adversos , Oxaliplatina , Taxoides/efeitos adversos , Resultado do Tratamento
4.
Phys Rev Lett ; 110(11): 118301, 2013 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-25166582

RESUMO

A competition of incommensurate symmetries occurs whenever a system is forced to conform to an ordering that is different from the intrinsically preferred structure of the system itself. As a model system of such a competition, we study the rivalry between the triangular ordering of hard disks and the square symmetry induced by a periodic square substrate. By using density functional theory as well as Monte Carlo computer simulations, we determine the full phase behavior for the case of one particle per minimum. We observe a rhombic preordering structure preceding the hexagonal solid as a direct consequence of the competing symmetries. Furthermore, the square-rhombic transition is reentrant with increasing substrate interaction. Our predictions can be verified in experiments of colloids in laser fields.

5.
J Chem Phys ; 138(7): 074905, 2013 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-23445033

RESUMO

We systematically investigate how the range of interaction between non-bonded monomers influences the formation of structural phases of elastic, flexible polymers. Massively parallel replica-exchange simulations of a generic, coarse-grained model, performed partly on graphics processing units and in multiple-gaussian modified ensembles, pave the way for the construction of the structural phase diagram, parametrized by interaction range and temperature. Conformational transitions between gas-like, liquid, and diverse solid (pseudo) phases are identified by microcanonical statistical inflection-point analysis. We find evidence for finite-size effects that cause the crossover of "collapse" and "freezing" transitions for very short interaction ranges.


Assuntos
Polímeros/química , Modelos Moleculares , Conformação Molecular , Temperatura
6.
Br J Cancer ; 100(2): 291-7, 2009 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-19127261

RESUMO

Brain metastases represent an important cause of morbidity in patients with lung cancer and are associated with a mean survival of less than 6 months. Thus, new regimens improving the outcome of these patients are urgently needed. On the basis of promising data raised in a phase I/II trial, we initiated an open, randomised, prospective, multicentric phase III trial, comparing whole brain radiation therapy (WBRT; 20 x 2 Gy) alone with WBRT+topotecan (RCT; 0.4 mg m(-2) day(-1) x 20). A total of 320 patients with CNS-metastases due to SCLC or NSCLC were projected. The primary end point was overall survival, whereas second end points were local response and progression-free survival. However, until the cutoff date of study completion (i.e., a study duration of 34 months), only a total of 96 (RCT:47, WBRT:49) patients had been recruited, and so an analysis was performed at that time point. Although the numbers of grade 3/4 non-haematological toxicities (besides alopecia 115 (RCT/WBRT: 55 out of 60) were evenly distributed, the 25 haematological events occurred mainly in the combined treatment arm (24 out of 1). Local response, evaluated 2 weeks after treatment, was assessable in 44 (RCT/WBRT: 23 out of 21) patients, showing CR in eight (3 out of 5), PR in 17 (11 out of 6), SD in 14 (8 out of 6) and PD in five (1 out of 4) patients (all differences n.s.). Neither OAS (RCT/WBRT: median (days)): 87 out of 95, range 3-752/4-433; HR 1.32; 95% CI (0.83; 2.10)) nor PFS (median (days)): 71 out of 66, range, 3-399/4-228; HR 1.28, 95% CI (0.73; 2.43) differed significantly. On the basis of these results and the slow recruitment, a continuation of the study did not seem reasonable. The available data show no significant advantage for concurrent radiochemotherapy for patients with lung cancer; however, the recruited number of patients is too low to exhibit a small advantage of combined treatment.


Assuntos
Antineoplásicos/uso terapêutico , Neoplasias Encefálicas/terapia , Carcinoma Pulmonar de Células não Pequenas/terapia , Irradiação Craniana , Neoplasias Pulmonares/terapia , Carcinoma de Pequenas Células do Pulmão/terapia , Topotecan/uso terapêutico , Adulto , Idoso , Neoplasias Encefálicas/tratamento farmacológico , Neoplasias Encefálicas/radioterapia , Neoplasias Encefálicas/secundário , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/radioterapia , Carcinoma Pulmonar de Células não Pequenas/secundário , Terapia Combinada , Feminino , Humanos , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/patologia , Neoplasias Pulmonares/radioterapia , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Prognóstico , Estudos Prospectivos , Qualidade de Vida , Carcinoma de Pequenas Células do Pulmão/tratamento farmacológico , Carcinoma de Pequenas Células do Pulmão/radioterapia , Carcinoma de Pequenas Células do Pulmão/secundário , Taxa de Sobrevida , Resultado do Tratamento
7.
Eur Phys J E Soft Matter ; 30(1): 7-18, 2009 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-19777280

RESUMO

In this work we investigate the structural properties of native states of a simple model for short flexible homopolymers, where the steric influence of monomeric side chains is effectively introduced by a thickness constraint. This geometric constraint is implemented through the concept of the global radius of curvature and affects the conformational topology of ground-state structures. A systematic analysis allows for a thickness-dependent classification of the dominant ground-state topologies. It turns out that helical structures, strands, rings, and coils are natural, intrinsic geometries of such tubelike objects.


Assuntos
Maleabilidade , Polímeros/química , Adsorção , Algoritmos , Simulação por Computador , Modelos Químicos , Propriedades de Superfície
8.
Clin Nephrol ; 67(1): 5-11, 2007 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-17269593

RESUMO

BACKGROUND: The development of nephrotic syndrome (NS) after allogeneic hematopoietic stem cell transplantation (HS-CT) is a rare complication with few long-term outcome data. PATIENTS: Clinical course and long-term outcome of three adult patients and one child with NS after HSCT (total number of transplants n = 533) are presented. RESULTS: The median age at onset of NS was 35 years (range 15 - 56), occurring at a median of 17 months (range 11 - 21) after HSCT. Discontinuation of cyclosporine A (CSA) prior to onset of NS was a consistent feature and occurred a median of 6 months (range 2 - 10 months) prior to the development of NS. The histopathological lesion was membranous nephropathy (n = 3) and membranoproliferative glomerulonephritis Type 1 (n = 1). History of acute or concomitant clinically apparent chronic graft versus host disease (GVHD) was present in all cases except the pediatric patient who had abundant DR-activated cytotoxic T cells without evidence of viral reactivation. Long-term immunosuppression for 11 - 36 months with steroids (n = 1), combined steroids and CSA (n = 2) or CSA alone in steroid-refractory NS (n = 1) resulted in sustained remission of the NS in all patients (12 months - 8 years off immunosuppression). CONCLUSION: NS after HSCT seems to be etiologically related to subclinical or overt chronic GVHD, which flares up after discontinuation of CSA. However, resumption of immunosuppression can reverse NS as well as GVHD and induce favorable sustained long-term remission.


Assuntos
Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Síndrome Nefrótica/etiologia , Adolescente , Adulto , Feminino , Doença Enxerto-Hospedeiro/etiologia , Humanos , Imunossupressores/efeitos adversos , Imunossupressores/uso terapêutico , Masculino , Pessoa de Meia-Idade , Síndrome Nefrótica/patologia , Prognóstico , Transplante Homólogo/efeitos adversos
9.
Phys Rev E Stat Nonlin Soft Matter Phys ; 76(4 Pt 2): 045701, 2007 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-17995052

RESUMO

We present a Monte Carlo algorithm that facilitates efficient parallel tempering simulations of the density of states g(E) . We show that the algorithm eliminates the supercritical slowing down in the case of the Q=20 and Q=256 Potts models in two dimensions, typical examples for systems with extreme first-order phase transitions. As recently predicted, and shown here, the microcanonical heat capacity along the calorimetric curve has negative values for finite systems.

10.
Phys Rev E Stat Nonlin Soft Matter Phys ; 75(5 Pt 1): 051803, 2007 May.
Artigo em Inglês | MEDLINE | ID: mdl-17677089

RESUMO

We simulate three-dimensional flexible off-lattice ring polymers of length L up to L=4000 for various values of the global radius of curvature Rgrc=0.25 , 0.48, and 1.0 and Rgrc=2.0 . We utilize two different ensembles: one with a delta -function constraint on the radius, and the other with a theta -function. For both cases the global radius of curvature provides a valid regularization of polymers with thickness D=2Rgrc . The Flory-type critical exponent nu SAW of self-avoiding rings at D=2 is found to be nu SAW=0.5869(5) from the radii of gyration chain length scaling, while other D values produce consistent results. For our current implementation, the numerical effort of chain thickness calculations is bounded by a number O(LlnL) per single update. We also study low-temperature configurations of spatially dense Lennard-Jones homopolymers on a ring and identify some conformational building blocks.

11.
J Med Genet ; 42(10): e63, 2005 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-16199545

RESUMO

BACKGROUND: Autosomal recessive polycystic kidney disease (ARPKD) is caused by mutations in the PKHD1 (polycystic kidney and hepatic disease 1) gene on chromosome 6p12, a large gene spanning 470 kb of genomic DNA. So far, only micromutations in the 66 exons encoding the longest open reading frame (ORF) have been described, and account for about 80% of mutations. OBJECTIVE: To test the hypothesis that gross genomic rearrangements and mutations in alternatively spliced exons contribute to a subset of the remaining disease alleles. METHODS: Using DHPLC for alternatively spliced exons and quantitative real time polymerase chain reaction to detect genomic imbalances, 58 ARPKD patients were screened, of whom 55 were known to harbour one PKHD1 point mutation in the longest ORF. RESULTS: Three different heterozygous PKHD1 deletions and several single nucleotide changes in alternatively spliced exons were identified. The detected partial gene deletions are most likely pathogenic, while a potential biological function of the alterations identified in alternatively spliced exons must await the definition of transcripts containing alternative exons and their predicted reading frames. CONCLUSIONS: Gross PKHD1 deletions account for a detectable proportion of ARPKD cases. Screening for major genomic PKHD1 rearrangements will further improve mutation analysis in ARPKD.


Assuntos
Deleção de Genes , Rim Policístico Autossômico Recessivo/genética , Receptores de Superfície Celular/genética , Sequência de Bases , Cromossomos Humanos Par 6 , Análise Mutacional de DNA , Éxons , Heterozigoto , Humanos , Dados de Sequência Molecular , Mutação , Fases de Leitura Aberta , Mutação Puntual , RNA Mensageiro/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa
12.
Phys Rev E Stat Nonlin Soft Matter Phys ; 74(3 Pt 2): 036702, 2006 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-17025781

RESUMO

We present a Monte Carlo algorithm, which samples free energies of complex systems. Less probable configurations are populated with the help of a multitude of additional Gaussian weights and parallel tempering is used for efficient Monte Carlo moves within phase space. The algorithm is easily parallelized and can be applied to a wide class of problems. We discuss algorithmic performance for the case of low-temperature phase separation in two-dimensional and three-dimensional Ising models, where we determine the magnetic interface tension. Multiple Gaussian modified ensemble simulations, unlike multicanonical ensemble simulations do not require a priori knowledge of the free energy and are of similar efficiency as multicanonical ensemble and Wang-Landau simulations.

13.
J Mol Med (Berl) ; 78(4): 212-6, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-10933583

RESUMO

alpha1-Antitrypsin (AAT) deficiency is a common inherited cause of emphysema and cirrhotic liver disease. Current laboratory diagnosis of Pi (proteinase inhibitor) status by protein analysis depends on the availability of blood samples and has a limited accuracy. Single-strand conformational polymorphism (SSCP) analysis and direct DNA sequencing can be performed from blood cells or from tissue samples, but it is a time-consuming procedure not suitable for screening purposes. We used a Light-Cycler assisted PCR approach to identify the PiZ mutation and to determine hetero- and homozygous carrier status from whole blood and from paraffin-embedded archival tissue specimens. The results were compared to those obtained by standard PCR amplification followed by SSCP and direct DNA sequencing. Light-Cycler assisted PCR identified heterozygous PiZ mutations in 16 samples, a homozygous PiZ status in three cases, and wild-type PiM in five control samples. In all cases the results were confirmed by SSCP and direct DNA sequencing. Light-Cycler assisted PCR has a high detection rate for the PiZ mutation. It can be performed from blood or from fixed archival tissues, requires only small amounts of DNA, and allows a rapid diagnosis on a high output level.


Assuntos
Reação em Cadeia da Polimerase/métodos , Deficiência de alfa 1-Antitripsina/genética , alfa 1-Antitripsina/genética , DNA/análise , Primers do DNA/química , Genótipo , Humanos , Fígado/patologia , Fenótipo , Polimorfismo Conformacional de Fita Simples , Análise de Sequência de DNA
14.
J Bone Miner Res ; 14(9): 1536-42, 1999 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-10469281

RESUMO

Dent's disease is an X-linked renal tubular disorder characterized by low-molecular-weight proteinuria, hypercalciuria, nephrocalcinosis, nephrolithiasis, and renal failure. Patients with Dent's disease may also suffer from rickets and other features of the renal Fanconi Syndrome. Patients may have mutations in the X-linked renal chloride channel gene, CLCN5, which encodes a 746-amino-acid protein with 12-13 transmembrane domains. We have investigated the 11 coding exons of CLCN5 for mutations in eight unrelated patients with Dent's disease. Leukocyte DNA was used for the polymerase chain reaction amplification of CLCN5 and the products analyzed for single-stranded conformational polymorphisms (SSCPs). Abnormal SSCPs were sequenced and revealed eight mutations. These consisted of three nonsense mutations (Arg34Stop, Arg648Stop, Arg704Stop), four deletions involving codons 40, 86, 157, and 241, and one acceptor splice consensus sequence mutation tgcag --> tgaag. The mutations were confirmed either by restriction endonuclease or sequence-specific oligonucleotide hybridization analysis. In addition, an analysis of 110 alleles from 74 unrelated normal individuals demonstrated that the DNA sequence changes were not common polymorphisms. All of the mutations predict truncated chloride channels that are likely to result in a functional loss. Thus, our findings expand the spectrum of CLCN5 mutations associated with Dent's disease and the results will help to elucidate further the functional domains of this novel chloride channel.


Assuntos
Canais de Cloreto/genética , Síndrome de Fanconi/genética , Mutação , Sequência de Aminoácidos , Canais de Cloreto/química , Feminino , Humanos , Masculino , Dados de Sequência Molecular , Linhagem , Reação em Cadeia da Polimerase , Polimorfismo Conformacional de Fita Simples , Estrutura Secundária de Proteína
15.
FEBS Lett ; 467(2-3): 299-304, 2000 Feb 11.
Artigo em Inglês | MEDLINE | ID: mdl-10675558

RESUMO

Endothelial cells play an important regulatory role in inflammatory responses by upregulating various proinflammatory gene products including cytokines and adhesion molecules. A highly potent mediator of this process is tumor necrosis factor-alpha (TNF). In the present study, the suppression subtractive hybridization (SSH) method was employed to identify rarely transcribed TNF-inducible genes in human umbilical arterial endothelial cells. Following mRNA isolation of non-stimulated and TNF-stimulated cells, cDNAs of both populations were prepared and subtracted by suppression PCR. Sequencing of the enriched cDNAs identified 12 genes differentially expressed including vascular cell adhesion molecule-1, monocyte chemoattractant protein-1, interleukin-8 and IkappaBalpha, an inhibitor of the transcription factor nuclear factor-kappaB. Interestingly, also syntenin, a PDZ motif-containing protein which binds to the cytoplasmic domain of syndecans, was identified by SSH. Time course studies using RT-PCR analysis confirmed that all genes were differentially expressed and rapidly induced by TNF. Our data reveal that SSH is a powerful technique of high sensitivity for the detection of differential gene expression in primary arterial endothelial cells.


Assuntos
Proteínas de Transporte/genética , DNA Complementar/metabolismo , Endotélio Vascular/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular , Proteínas de Membrana , Hibridização de Ácido Nucleico/métodos , Fator de Necrose Tumoral alfa/farmacologia , Separação Celular , Endotélio Vascular/citologia , Endotélio Vascular/efeitos dos fármacos , Humanos , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , Sinteninas , Artérias Umbilicais
16.
Eur J Pharmacol ; 309(2): 209-13, 1996 Aug 08.
Artigo em Inglês | MEDLINE | ID: mdl-8874141

RESUMO

The present study investigated the metabolism of glyceryl trinitrate by washed human platelets as compared to that by rat vascular smooth muscle cells. Possible changes in metabolism after induction of nitrate tolerance were also studied in both systems. Incubation of the cells with glyceryl trinitrate (0.1 mM) resulted in a time-dependent release of nitrite (NO2-) amounting to 6.30 +/- 0.63 nmol mg protein-1 h-1 in vascular smooth muscle cells and 0.61 +/- 0.08 nmol mg protein-1 h-1 for platelets, respectively. The nitric oxide (NO) scavenger, oxyhemoglobin (10 microM), significantly reduced NO2- generation in both cell types studied. Nitrate tolerance was induced by incubation of the cells with glyceryl trinitrate (2 mM) for 2 h. In tolerant vascular smooth muscle cells as well as in tolerant platelets, NO2- release was significantly reduced. The inhibitory capacity of glyceryl trinitrate on ADP (6 microM)-induced platelet aggregation and on intracellular Ca2+ signals was significantly reduced in tolerant platelets. The data show a direct metabolism of glyceryl trinitrate by human blood platelets which is subject to a type of tolerance development similar to that in vascular smooth muscle cells.


Assuntos
Plaquetas/metabolismo , Músculo Liso Vascular/efeitos dos fármacos , Nitroglicerina/farmacocinética , Animais , Biotransformação , Humanos , Músculo Liso Vascular/citologia , Músculo Liso Vascular/metabolismo , Nitritos/metabolismo , Nitroglicerina/farmacologia , Inibidores da Agregação Plaquetária/farmacologia , Ratos , Ratos Endogâmicos WKY
17.
Med Clin North Am ; 85(6): 1413-25, 2001 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11680110

RESUMO

Based on the recognition of the main pathophysiologic features of pneumonia and currently available data on prognosis and clinical severity assessment, key points for a definition of severe pneumonia are as follows: 1. Independent predictors of pneumonia severity are factors reflecting acute respiratory failure and severe sepsis or septic shock. 2. In view of the dependence of the development of acute respiratory failure on pulmonary comorbidities, radiographic extension may prove to be an additional independent predictor of severe respiratory compromise. 3. Vital sign abnormalities other than acute respiratory failure and severe hypotension may be independent predictors of severity, particularly in patients presenting in early and asymptomatic stages of severe sepsis. 4. Several pathogens have been shown to have adverse prognostic potential. Because the cause is unknown at the initial evaluation, however, pathogens cannot form part of the criteria for the initial severity assessment. 5. Because pneumonia is a dynamic process, any assessment of severity takes place at an arbitrary point of disease evolution. It would be desirable to define a set of parameters reflecting initial severity as well as a state of increased risk for early deterioration toward severe pneumonia. 6. Severity stratification within the population of patients with severe pneumonia may open the prospect of identifying patients who may have the greatest benefit from intensive care.


Assuntos
Infecções Comunitárias Adquiridas/classificação , Infecções Comunitárias Adquiridas/diagnóstico , Pneumonia/classificação , Pneumonia/diagnóstico , Índice de Gravidade de Doença , Fatores Etários , Infecções Comunitárias Adquiridas/complicações , Infecções Comunitárias Adquiridas/microbiologia , Infecções Comunitárias Adquiridas/fisiopatologia , Comorbidade , Predisposição Genética para Doença , Humanos , Pneumonia/complicações , Pneumonia/microbiologia , Pneumonia/fisiopatologia , Valor Preditivo dos Testes , Prognóstico , Reprodutibilidade dos Testes , Insuficiência Respiratória/microbiologia , Medição de Risco , Fatores de Risco , Sepse/microbiologia , Choque Séptico/microbiologia
18.
Clin Nephrol ; 56(6): S9-12, 2001 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11770813

RESUMO

Urinary tract anomalies (UTA) including polycystic kidney disease nowadays can be detected antenatally by ultrasound. The concomitant presence of oligohydramnios has been regarded as a severe risk factor for renal dysfunction and pulmonary hypoplasia, although clinical data after birth are scarce. We report the postnatal course and long-term follow-up of 10 infants with oligohydramnios due to congenital UTA from two pediatric nephrology centers. The underlying final diagnoses were autosomal-recessive polycystic kidney disease (ARPKD, n = 2), familial tubular dysgenesis (n = 2) and bilateral renal hypoplasia (n = 6) including 3 children with posterior urethral valves. Two children died in the neonatal period while 8 children are currently alive at a median age of 2.5 (range 1.1-10) years. In the postnatal period, respiratory failure necessitating mechanical ventilation occurred in 7 infants (including the 2 non-survivors). All surviving children had chronic renal failure, which could be managed conservatively in 6 children (median GFR 45 (range 15-53) ml/min/1.73 m2) while 2 reached end-stage renal disease; one undergoing preemptive kidney transplantation and one peritoneal dialysis. Seven of 8 children reached normal developmental milestones. In conclusion, the presence of antenatal oligohydramnios in infants with UTA does not always carry a poor prognosis. The high incidence of perinatal complications, the complexity of underlying causes and the prevalence of postnatal chronic renal dysfunction calls for a multidisciplinary approach in the management of these children.


Assuntos
Doenças Fetais/diagnóstico por imagem , Oligo-Hidrâmnio/diagnóstico por imagem , Doenças Renais Policísticas/diagnóstico por imagem , Complicações na Gravidez , Ultrassonografia Pré-Natal , Sistema Urinário/anormalidades , Feminino , Idade Gestacional , Humanos , Recém-Nascido , Masculino , Oligo-Hidrâmnio/etiologia , Doenças Renais Policísticas/complicações , Gravidez , Prognóstico , Síndrome do Desconforto Respiratório do Recém-Nascido/etiologia , Síndrome do Desconforto Respiratório do Recém-Nascido/terapia , Estudos Retrospectivos , Sistema Urinário/diagnóstico por imagem , Ventiladores Mecânicos
19.
Artigo em Inglês | MEDLINE | ID: mdl-24483453

RESUMO

Using microscopic dynamical density functional theory, we calculate the dynamical formation of polycrystals by following the crystal growth around multiple crystalline seeds imposed to an undercooled fluid. Depending on the undercooling and the size ratio as well as the relative crystal orientation of two neighboring seeds, three possibilities of the final state emerge, namely no crystallization at all, formation of a monocrystal, or two crystallites separated by a curved grain boundary. Our results, which are obtained for two-dimensional hard disk systems using a fundamental-measure density functional, shed new light on the particle-resolved structure and growth of polycrystalline material in general.

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