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1.
Phys Rev Lett ; 128(8): 083901, 2022 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-35275645

RESUMO

Time delayed dynamical systems have proven to be a fertile framework for the study of physical phenomena. In natural sciences, their uses have been limited to the study of dissipative dynamics. In this Letter, we demonstrate the existence of nonlinear reversible conservative time delayed systems. We consider the example of a dispersive microcavity containing a Kerr medium coupled to a distant external mirror. At low energies and in the long delay limit, a multiscale analysis shows the equivalence with the nonlinear Schrödinger equation. We unveil some of the symmetries and conserved quantities, as well as bright temporal solitons. While elastic collisions occur for shallow wave packets, we observe the lack of integrability at higher energies. We recover the Lugiato-Lefever equation in the weakly dissipative regime.

2.
Opt Lett ; 46(5): 1109-1112, 2021 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-33649669

RESUMO

We analyze the effect of optical feedback on the dynamics of an external-cavity passively mode-locked surface-emitting laser operating in the regime of temporal localized structures. Depending on the ratio between the cavity round trip time and the feedback delay, we show experimentally that feedback acts as a solution selector that either reinforces or hinders the appearance of one of the multistable harmonic arrangements of pulses. Our theoretical analysis reproduces well the experiment and allows us to evidence asymmetrical resonance tongues due to the parity symmetry-breaking induced by gain depletion.

3.
Anaesthesia ; 69(9): 990-1001, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24894025

RESUMO

The i-scoop is an intubation device with a curved guiding bar with laterally located lenses at its tip, rather than a blade. Twenty-five anaesthesiologists intubated a manikin that simulated first a normal and then a difficult airway. All participants were able to intubate the difficult airway with a good view of the glottis using the i-scoop. None was able to intubate using seven other laryngoscopes (Macintosh laryngoscope, GlideScope(®) GVL and AVL, McGrath(®) (Series 5/MAC), C-MAC(®) , A.P. Advance(™) ). Intubation was successful only with the Airtraq(®) (n = 10), the Airway Scope (n = 5), the C-MAC D-Blade (n = 2), the A.P. Advance DAB (n = 1) and the GlideScope DL Trainer (n = 1) (p < 0.001, success rate of i-scoop vs all 12 laryngoscopes combined). In contrast to all other videolaryngoscopes, intubation of the normal airway with the i-scoop was achieved even faster than with the Macintosh laryngoscope (p < 0.02). The i-scoop outperformed all other laryngoscopes in both difficult and normal airways, and therefore has potential as an easier and safer alternative to present devices.


Assuntos
Manuseio das Vias Aéreas/instrumentação , Intubação Intratraqueal/instrumentação , Laringoscópios , Competência Clínica , Determinação de Ponto Final , Humanos , Intubação Intratraqueal/efeitos adversos , Laringoscópios/efeitos adversos , Laringoscopia , Manequins , Tomografia Computadorizada por Raios X
4.
Front Bioeng Biotechnol ; 12: 1363538, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38646013

RESUMO

Introduction: Recent advances have enabled organotypic culture of beating human myocardial slices that are stable for weeks. However, human myocardial samples are rare, exhibit high variability and frequently originate from diseased hearts. Thus, there is a need to adapt long-term slice culture for animal myocardium. When applied to animal cardiac slices, studies in healthy or genetically modified myocardium will be possible. We present the culture of slices from rabbit hearts, which resemble the human heart in microstructure, electrophysiology and excitation-contraction coupling. Methods: Left ventricular myocardium from New Zealand White rabbits was cut using a vibratome and cultured in biomimetic chambers for up to 7 days (d). Electro-mechanical uncoupling agents 2,3-butanedione monoxime (BDM) and cytochalasin D (CytoD) were added during initiation of culture and effects on myocyte survival were quantified. We investigated pacing rates (0.5 Hz, 1 Hz, and 2 Hz) and hormonal supplements (cortisol, T3, catecholamines) at physiological plasma concentrations. T3 was buffered using BSA. Contractile force was recorded continuously. Glucose consumption and lactate production were measured. Whole-slice Ca2+ transients and action potentials were recorded. Effects of culture on microstructure were investigated with confocal microscopy and image analysis. Results: Protocols for human myocardial culture resulted in sustained contracture and myocyte death in rabbit slices within 24 h, which could be prevented by transient application of a combination of BDM and CytoD. Cortisol stabilized contraction amplitude and kinetics in culture. T3 and catecholaminergic stimulation did not further improve stability. T3 and higher pacing rates increased metabolic rate and lactate production. T3 stabilized the response to ß-adrenergic stimulation over 7 d. Pacing rates above 1 Hz resulted in progredient decline in contraction force. Image analysis revealed no changes in volume fractions of cardiomyocytes or measures of fibrosis over 7 d. Ca2+ transient amplitudes and responsiveness to isoprenaline were comparable after 1 d and 7 d, while Ca2+ transient duration was prolonged after 7 d in culture. Conclusions: A workflow for rabbit myocardial culture has been established, preserving function for up to 7 d. This research underscores the importance of glucocorticoid signaling in maintaining tissue function and extending culture duration. Furthermore, BDM and CytoD appear to protect from tissue damage during the initiation phase of tissue culture.

5.
Mol Hum Reprod ; 16(9): 665-84, 2010 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-20406800

RESUMO

Mitotic centromere-associated kinesin (MCAK) is an ATP-dependent microtubule (MT) depolymerase regulated by Aurora kinase (AURK) phosphorylation and implicated in resolution of improper MT attachments in mitosis. Distribution of MCAK was studied in oocyte maturation by anti-MCAK antibody, anti-tubulin antibody, anti-AURKB antibody and anti-centromere antibody (ACA) and by the expression of MCAK-enhanced green fluorescent protein fusion protein in maturing mouse oocytes. Function was assessed by knockdown of MCAK and Mad2, by inhibiting AURK or the proteasome, by live imaging with polarization microscope and by chromosomal analysis. The results show that MCAK is transiently recruited to the nucleus and transits to spindle poles, ACA-positive domains and chiasmata at prometaphase I. At metaphase I and II, it is present at centrosomes and centromeres next to AURKB and checkpoint proteins Mad2 and BubR1. It is retained at centromeres at telophase I and also at the midbody. Knockdown of MCAK causes a delay in chromosome congression but does not prevent bipolar spindle assembly. MCAK knockdown also induces a meiosis I arrest, which is overcome by knockdown of Mad2 resulting in chiasma resolution, chromosome separation, formation of aberrant meiosis II spindles and increased hypoploidy. In conclusion, MCAK appears to possess a unique distribution and function in oocyte maturation. It is required for meiotic progression from meiosis I to meiosis II associated with silencing of the spindle assembly checkpoint. Alterations in abundance and activity of MCAK, as implicated in aged oocytes, may therefore contribute to the loss of control of cell cycle and chromosome behaviour, thus increasing risk for errors in chromosome segregation and aneuploidy.


Assuntos
Proteínas de Ciclo Celular/metabolismo , Centrômero/enzimologia , Cinesinas/metabolismo , Meiose , Mitose , Oócitos/enzimologia , Fuso Acromático/enzimologia , Animais , Aurora Quinase B , Aurora Quinases , Proteínas de Ciclo Celular/genética , Nucléolo Celular/enzimologia , Células Cultivadas , Centrômero/efeitos dos fármacos , Segregação de Cromossomos , Inibidores de Cisteína Proteinase/farmacologia , Feminino , Cinesinas/genética , Proteínas Mad2 , Camundongos , Microinjeções , Oócitos/efeitos dos fármacos , Fosforilação , Ploidias , Complexo de Endopeptidases do Proteassoma/metabolismo , Inibidores de Proteassoma , Inibidores de Proteínas Quinases/farmacologia , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Proteínas Serina-Treonina Quinases/metabolismo , Transporte Proteico , Interferência de RNA , Proteínas Recombinantes de Fusão/metabolismo , Fuso Acromático/efeitos dos fármacos , Fatores de Tempo
6.
Vet J ; 263: 105520, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32928489

RESUMO

There is limited information regarding the value of constitutive components of the ACTH stimulation test (ACTHST) and low-dose dexamethasone suppression test (LDDST) including serum baseline cortisol (BC), difference between post-ACTH stimulation cortisol (PC) and BC (ΔACTHC), cortisol concentration 4h after dexamethasone administration (4HC), difference between 4HC and BC (Δ4C), and the difference between cortisol concentration 8h after dexamethasone administration and 4HC (Δ8C). Therefore, the objective of this study was to determine if these components can predict hyperadrenocorticism, pituitary-dependent hyperadrenocorticism (PDH), or functional adrenocortical tumor (FAT) in dogs. Cortisol concentrations were normalized, as fold change (FC), to the PC reference interval upper limit. A total of 1267 dogs were included, with hyperadrenocorticism diagnosed in 537 (PDH, n=356; FAT, n=28; undetermined, n=153) and excluded in 730. The area under the receiver operating curves for BC, ΔACTHC, 4HC, Δ4C, and Δ8C to predict hyperadrenocorticism were 0.76 (95% confidence interval (CI), 0.73-0.79), 0.91 (95% CI, 0.89-0.93), 0.83 (95% CI, 0.80-0.87), 0.55 (95% CI, 0.50-0.60), and 0.67 (95% CI, 0.62-0.72), respectively. A diagnostic limit of ≥0.78 FC for ΔACTHC had excellent sensitivity (1.00; 95% CI, 0.74-1.00), but poor specificity (0.67; 95% CI, 0.64-0.71), to predict FAT in dogs with a positive ACTHST. A diagnostic limit of ≥-0.26 FC for Δ4C had excellent sensitivity (1.00; 95% CI, 0.79-1.00), but poor specificity (0.21; 95% CI, 0.18-0.26), to predict FAT in dogs with a positive LDDST. In hyperadrenocorticoid dogs that have positive ACTHST or LDDST results, ΔACTHC or Δ4C, respectively, could be used to exclude FAT.


Assuntos
Glândulas Suprarrenais/fisiopatologia , Hiperfunção Adrenocortical/veterinária , Doenças do Cão/diagnóstico , Neoplasias do Córtex Suprarrenal/diagnóstico , Neoplasias do Córtex Suprarrenal/fisiopatologia , Neoplasias do Córtex Suprarrenal/veterinária , Hiperfunção Adrenocortical/diagnóstico , Hormônio Adrenocorticotrópico/administração & dosagem , Animais , Área Sob a Curva , Dexametasona/administração & dosagem , Doenças do Cão/fisiopatologia , Cães , Feminino , Hidrocortisona/sangue , Masculino , Hipófise/fisiopatologia , Curva ROC , Estudos Retrospectivos , Sensibilidade e Especificidade
7.
Eur J Med Res ; 14(7): 277-83, 2009 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-19661009

RESUMO

OBJECTIVE: To investigate if early treatment of primary HIV-1 infection (PHI) reduces viral set point and/or increases CD4 lymphocytes. METHODS: Analysis of two prospective multi-centre PHI cohorts. HIV-1 RNA and CD4 lymphocytes in patients with transient treatment were compared to those in untreated patients. Time to CD4 lymphocyte decrease below 350/ microl after treatment stop or seroconversion was calculated using Kaplan-Meier and Cox-PH-regression analyses. RESULTS: 156 cases of PHI were included, of which 100 had received transient HAART (median treatment time 9.5 months) and 56 remained untreated. Median viral load (563000 cop/ml vs 240000 cop/ml; p<0.001) and median CD4 lymphocyte (449/ microl vs. 613/ microl; p<0.01) differed significantly between treated and untreated patients. Median viral load was 38056 copies/ml in treated patients (12 months after treatment stop) and 52880 copies/ml in untreated patients (12 months after seroconversion; ns). Median CD4 lymphocyte change was +60/ microl vs. -86/ microl (p = 0.01). Median time until CD4 lymphocytes decreased to <350/ microl (including all patients with CD4 lymphocytes <500/ microl during seroconversion) was 20.7 months in treated patients after treatment stop and 8.3 months in untreated patents after seroconversion (p<0.01). Cox-PH analyses adjusting for baseline VL, CD4 lymphocytes, stage of early infection and symptoms confirmed these differences. CONCLUSIONS: Treatment during PHI did not lower viral set point. However, patients treated during seroconversion had an increase in CD4 lymphocytes, whereas untreated patients experienced a decrease in CD4 lymphocytes. Time until reaching CD4 lymphocytes <350/ microl was significantly shorter in untreated than in treated patients including patients with CD4 lymphocytes <500/ microl during seroconversion.


Assuntos
Terapia Antirretroviral de Alta Atividade/métodos , Contagem de Linfócito CD4 , Infecções por HIV/tratamento farmacológico , HIV-1/efeitos dos fármacos , Adolescente , Adulto , Estudos de Coortes , Feminino , Infecções por HIV/imunologia , Infecções por HIV/virologia , Soropositividade para HIV/tratamento farmacológico , Soropositividade para HIV/imunologia , Soropositividade para HIV/virologia , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Estudos Multicêntricos como Assunto , Avaliação de Resultados em Cuidados de Saúde/métodos , Avaliação de Resultados em Cuidados de Saúde/estatística & dados numéricos , Modelos de Riscos Proporcionais , Fatores de Tempo , Carga Viral , Adulto Jovem
8.
Prog Biophys Mol Biol ; 130(Pt B): 302-314, 2017 11.
Artigo em Inglês | MEDLINE | ID: mdl-28709857

RESUMO

The transverse tubular system (t-system) of ventricular cardiomyocytes is essential for efficient excitation-contraction coupling. In cardiac diseases, such as heart failure, remodeling of the t-system contributes to reduced cardiac contractility. However, mechanisms of t-system remodeling are incompletely understood. Prior studies suggested an association with altered cardiac biomechanics and gene expression in disease. Since fibrosis may alter tissue biomechanics, we investigated the local microscopic association of t-system remodeling with fibrosis in a rabbit model of myocardial infarction (MI). Biopsies were taken from the MI border zone of 6 infarcted hearts and from 6 control hearts. Using confocal microscopy and automated image analysis, we quantified t-system integrity (ITT) and the local fraction of extracellular matrix (fECM). In control, fECM was 18 ± 0.3%. ITT was high and homogeneous (0.07 ± 0.006), and did not correlate with fECM (R2 = 0.05 ± 0.02). The MI border zone exhibited increased fECM within 3 mm from the infarct scar (30 ± 3.5%, p < 0.01 vs control), indicating fibrosis. Myocytes in the MI border zone exhibited significant t-system remodeling, with dilated, sheet-like components, resulting in low ITT (0.03 ± 0.008, p < 0.001 vs control). While both fECM and t-system remodeling decreased with infarct distance, ITT correlated better with decreasing fECM (R2 = 0.44) than with infarct distance (R2 = 0.24, p < 0.05). Our results show that t-system remodeling in the rabbit MI border zone resembles a phenotype previously described in human heart failure. T-system remodeling correlated with the amount of local fibrosis, which is known to stiffen cardiac tissue, but was not found in regions without fibrosis. Thus, locally altered tissue mechanics may contribute to t-system remodeling.


Assuntos
Ventrículos do Coração/patologia , Infarto do Miocárdio/patologia , Estresse Mecânico , Animais , Fenômenos Biomecânicos , Matriz Extracelular/metabolismo , Fibrose , Masculino , Miócitos Cardíacos/patologia , Coelhos
9.
Ann Biomed Eng ; 44(5): 1436-1448, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-26399990

RESUMO

Microstructural characterization of cardiac tissue and its remodeling in disease is a crucial step in many basic research projects. We present a comprehensive approach for three-dimensional characterization of cardiac tissue at the submicrometer scale. We developed a compression-free mounting method as well as labeling and imaging protocols that facilitate acquisition of three-dimensional image stacks with scanning confocal microscopy. We evaluated the approach with normal and infarcted ventricular tissue. We used the acquired image stacks for segmentation, quantitative analysis and visualization of important tissue components. In contrast to conventional mounting, compression-free mounting preserved cell shapes, capillary lumens and extracellular laminas. Furthermore, the new approach and imaging protocols resulted in high signal-to-noise ratios at depths up to 60 µm. This allowed extensive analyzes revealing major differences in volume fractions and distribution of cardiomyocytes, blood vessels, fibroblasts, myofibroblasts and extracellular space in control vs. infarct border zone. Our results show that the developed approach yields comprehensive data on microstructure of cardiac tissue and its remodeling in disease. In contrast to other approaches, it allows quantitative assessment of all major tissue components. Furthermore, we suggest that the approach will provide important data for physiological models of cardiac tissue at the submicrometer scale.


Assuntos
Ventrículos do Coração , Imageamento Tridimensional , Miocárdio , Remodelação Ventricular , Animais , Vasos Coronários/metabolismo , Vasos Coronários/patologia , Vasos Coronários/fisiopatologia , Ventrículos do Coração/metabolismo , Ventrículos do Coração/patologia , Ventrículos do Coração/fisiopatologia , Microscopia Confocal , Miocárdio/metabolismo , Miocárdio/patologia , Miócitos Cardíacos/metabolismo , Miócitos Cardíacos/patologia , Miofibroblastos/metabolismo , Miofibroblastos/patologia , Coelhos
10.
Aktuelle Urol ; 36(5): 417-22, 2005 Sep.
Artigo em Alemão | MEDLINE | ID: mdl-16163604

RESUMO

PURPOSE: Several occupational carcinogens are metabolized by polymorphic enzymes. The distribution of the polymorphic enzymes N-acetyltransferase 2 (NAT2; substrates: aromatic amines), glutathione S-transferase M1 (GSTM1; substrates: e. g., reactive metabolites of polycyclic aromatic hydrocarbons), and glutathione S-transferase T1 (GSTT1; substrates: small molecules with 1 - 2 carbon atoms) were investigated. MATERIAL AND METHODS: At the urological department in Lutherstadt Wittenberg, 136 patients with a histologically proven transitional cell cancer of the urinary bladder were investigated for all occupations performed for more than 6 months. Several occupational and non-occupational risk factors were asked. The genotypes of NAT2, GSTM1, and GSTT1 were determined from leucocyte DNA by PCR. RESULTS: Compared to the general population in Middle Europe, the percentage of GSTT1 negative persons (22.1 %) was ordinary; the percentage of slow acetylators (59.6 %) was in the upper normal range, while the percentage of GSTM1 negative persons (58.8 %) was elevated in the entire group. Shifts in the distribution of the genotypes were observed in subgroups who had been exposed to asbestos (6/6 GSTM1 negative, 5/6 slow acetylators), rubber manufacturing (8/10 GSTM1 negative), and chlorinated solvents (9/15 GSTM1 negative). CONCLUSIONS: The overrepresentation of GSTM1 negative bladder cancer patients also in this industrialized area and more pronounced in several occupationally exposed subgroups points to an impact of the GSTM1 negative genotype in bladder carcinogenesis.


Assuntos
Carcinoma de Células de Transição/epidemiologia , Exposição Ocupacional/efeitos adversos , Neoplasias da Bexiga Urinária/epidemiologia , Acetiltransferases/genética , Adulto , Amianto/efeitos adversos , Carcinoma de Células de Transição/induzido quimicamente , Carcinoma de Células de Transição/enzimologia , Carcinoma de Células de Transição/genética , Genótipo , Alemanha/epidemiologia , Glutationa Transferase/genética , Humanos , Ocupações , Reação em Cadeia da Polimerase , Polimorfismo Genético , Fatores de Risco , Borracha/efeitos adversos , Solventes/efeitos adversos , Fatores de Tempo , Neoplasias da Bexiga Urinária/induzido quimicamente , Neoplasias da Bexiga Urinária/enzimologia , Neoplasias da Bexiga Urinária/genética
11.
Br J Pharmacol ; 172(22): 5403-13, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26375408

RESUMO

BACKGROUND AND PURPOSE: ß2/3-subunit-selective modulation of GABAA receptors by valerenic acid (VA) is determined by the presence of transmembrane residue ß2/3N265. Currently, it is not known whether ß2/3N265 is part of VA's binding pocket or is involved in the transduction pathway of VA's action. The aim of this study was to clarify the localization of VA's binding pocket on GABAA receptors. EXPERIMENTAL APPROACH: Docking and a structure-based three-dimensional pharmacophore were employed to identify candidate amino acid residues that are likely to interact with VA. Selected amino acid residues were mutated, and VA-induced modulation of the resulting GABAA receptors expressed in Xenopus oocytes was analysed. KEY RESULTS: A binding pocket for VA at the ß(+) /α(-) interface encompassing amino acid ß3N265 was predicted. Mutational analysis of suggested amino acid residues revealed a complete loss of VA's activity on ß3M286W channels as well as significantly decreased efficacy and potency of VA on ß3N265S and ß3F289S receptors. In addition, reduced efficacy of VA-induced IGABA enhancement was also observed for α1M235W, ß3R269A and ß3M286A constructs. CONCLUSIONS AND IMPLICATIONS: Our data suggest that amino acid residues ß3N265, ß3F289, ß3M286, ß3R269 in the ß3 subunit, at or near the etomidate/propofol binding site(s), form part of a VA binding pocket. The identification of the binding pocket for VA is essential for elucidating its pharmacological effects and might also help to develop new selective GABAA receptor ligands.


Assuntos
Indenos/farmacologia , Receptores de GABA-A/metabolismo , Sesquiterpenos/farmacologia , Animais , Sítios de Ligação , Feminino , Simulação de Acoplamento Molecular , Mutagênese Sítio-Dirigida , Oócitos/metabolismo , Receptores de GABA-A/genética , Xenopus laevis
12.
Spine (Phila Pa 1976) ; 21(13): 1527-9, 1996 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-8817779

RESUMO

STUDY DESIGN: This case-control study was undertaken to determine if relatives of patients who had been admitted for surgery for degenerative disc disease-related problems were at increased risk for lower back pain or sciatica. OBJECTIVES: To determine if familial factors play a role in placing a person at risk for development of degenerative disc disease of the lumbar spine. SUMMARY OF BACKGROUND DATA: It is known that smoking and various occupational factors can place a person at risk for degenerative disc disease problems. It is not known if a familial predisposition may also exist. METHODS: The family members and relatives of 65 patients who had undergone surgery for lumbar degenerative disc disease were interviewed with a standardized questionnaire and compared with a control group of 67 patients who had been admitted to hospital for non-spine-related orthopedic procedures. The same interview and standardized questionnaire was used for both groups by a single observer. RESULTS: In the study group of 65 patients who had undergone surgery for degenerative disc disease, 44.6% were noted to have a positive family history, whereas 25.4% of the patients in the control group had a positive family history. Eighteen and one-half percent of relatives in the study group had a history of having spinal surgery, compared with only 4.5% of the control group. CONCLUSIONS: The results indicate that a familial predisposition to degenerative disc disease can exist along with other risk factors.


Assuntos
Deslocamento do Disco Intervertebral/genética , Disco Intervertebral/patologia , Adulto , Estudos de Casos e Controles , Saúde da Família , Feminino , Humanos , Incidência , Disco Intervertebral/cirurgia , Deslocamento do Disco Intervertebral/diagnóstico , Deslocamento do Disco Intervertebral/epidemiologia , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade
13.
Acta Cytol ; 29(5): 775-80, 1985.
Artigo em Inglês | MEDLINE | ID: mdl-3901642

RESUMO

Distinguishing chronic lymphocytic leukemia (CLL) or well-differentiated lymphocytic lymphoma (WDLL) from a benign chronic inflammatory process involving the serous cavities is often a difficult task for the cytopathologist faced with a lymphocyte-rich effusion fluid. Spriggs and Boddington decribed characteristic heavy chromatin clumping (cellules grumelées) of the lymphocytic nuclei in effusions as diagnostic of chronic lymphocytic leukemia. A study of 23 cases of lymphocyte-rich pleural effusions in our laboratory showed that, while this cytomorphologic feature is a function of cytopreparatory technique and fixation, it was observed only in cases of CLL or WDLL and not in benign inflammatory processes.


Assuntos
Leucemia Linfoide/diagnóstico , Linfoma/diagnóstico , Derrame Pleural/patologia , Diferenciação Celular , Núcleo Celular/ultraestrutura , Diagnóstico Diferencial , Técnicas Histológicas , Humanos , Leucemia Linfoide/patologia , Linfócitos/patologia , Linfocitose/diagnóstico , Linfocitose/patologia , Linfoma/patologia
14.
Mitochondrion ; 11(5): 783-96, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-20817047

RESUMO

Mammalian oocytes are long-lived cells in the human body. They initiate meiosis already in the embryonic ovary, arrest meiotically for long periods in dictyate stage, and resume meiosis only after extensive growth and a surge of luteinizing hormone which mediates signaling events that overcome meiotic arrest. Few mitochondria are initially present in the primordial germ cells while there are mitogenesis and structural and functional differentiation and stage-specific formation of functionally diverse domains of mitochondria during oogenesis. Mitochondria are most prominent cell organelles in oocytes and their activities appear essential for normal spindle formation and chromosome segregation, and they are one of the most important maternal contributions to early embryogenesis. Dysfunctional mitochondria are discussed as major factor in predisposition to chromosomal nondisjunction during first and second meiotic division and mitotic errors in embryos, and in reduced quality and developmental potential of aged oocytes and embryos. Several lines of evidence suggest that damage by oxidative stress/reactive oxygen species in dependence of age, altered antioxidative defence and/or altered environment and bi-directional signaling between oocyte and the somatic cells in the follicle contribute to reduced quality of oocytes and blocked or aberrant development of embryos after fertilization. The review provides an overview of mitogenesis during oogenesis and some recent data on oxidative defence systems in mammalian oocytes, and on age-related changes as well as novel approaches to study redox regulation in mitochondria and ooplasm. The latter may provide new insights into age-, environment- and cryopreservation-induced stress and mitochondrial dysfunction in oocytes and embryos.


Assuntos
Mitocôndrias/fisiologia , Oócitos/fisiologia , Envelhecimento , Animais , Técnicas Biossensoriais/métodos , Citoplasma/metabolismo , DNA Mitocondrial/genética , DNA Mitocondrial/metabolismo , Humanos , Mitocôndrias/metabolismo , Oócitos/metabolismo , Forma das Organelas , Oxirredução , Espécies Reativas de Oxigênio/metabolismo
15.
Br J Pharmacol ; 164(2b): 607-16, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21542828

RESUMO

BACKGROUND AND PURPOSE: We investigated the influence of metoprolol on gap junction proteins connexin43 (Cx43) and connexin40 (Cx40) in atrial tissue from patients with/without atrial fibrillation (AF). EXPERIMENTAL APPROACH: Left atrial tissue samples from 160 patients with AF or sinus rhythm (SR) with or without metoprolol (mean daily dose: 65.2 ± 9.1 mg·day⁻¹) were analysed for Cx43 and Cx40 by Western blot and immunohistology. Transverse and longitudinal conduction velocities were determined by 64 multi-electrode mapping. KEY RESULTS: Both Cx43 and Cx40 expression were significantly increased in patients with AF versus SR. Cx43-expression in AF was significantly higher in patients receiving metoprolol, while Cx40 expression was unaffected by metoprolol treatment. In AF, the ratio of lateral/polar expression of Cx43 and Cx40 was enhanced due to increased expression at the sides of the cells (lateral) and a loss at the cell poles. This AF-induced increase in lateral/polar expression of Cx43, but not of Cx40, was significantly antagonized by metoprolol treatment. Functionally, in AF patients, transverse conduction velocity in atrial samples was significantly enhanced and this change was also significantly antagonized by metoprolol. CONCLUSIONS AND IMPLICATIONS: AF induced enhanced lateral expression of Cx43 and Cx40 together with enhanced transverse conduction velocity in left atrial tissue. Alterations in localization of Cx43 and conduction changes were both antagonized by metoprolol, showing that pharmacological modulation of gap junction remodelling seems, in principle, possible. This finding may open new approaches to the development of anti-arrythmic drugs.


Assuntos
Fibrilação Atrial/tratamento farmacológico , Fibrilação Atrial/patologia , Junções Comunicantes/efeitos dos fármacos , Junções Comunicantes/patologia , Metoprolol/farmacologia , Antagonistas de Receptores Adrenérgicos beta 1/farmacologia , Fibrilação Atrial/genética , Fibrilação Atrial/metabolismo , Doença Crônica , Conexina 43/antagonistas & inibidores , Conexina 43/genética , Conexina 43/metabolismo , Conexinas/antagonistas & inibidores , Conexinas/genética , Conexinas/metabolismo , Feminino , Junções Comunicantes/genética , Junções Comunicantes/metabolismo , Átrios do Coração/efeitos dos fármacos , Átrios do Coração/metabolismo , Átrios do Coração/patologia , Humanos , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Proteína alfa-5 de Junções Comunicantes
16.
Arch Pharm (Weinheim) ; 328(2): 131-5, 1995 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-7726738

RESUMO

Fifteen fluorescent oligoamines with one or two fluorescent groups and two or three basic N-functions were prepared and tested for antiplatelet activity (Born-test). Five compounds involving three different fluorophores, i.e. 2-fluorenyl, 1-pyrenyl, and 9-phenanthryl, show an IC50 of 7-11 mumol/L. They are suitable to serve as probes in the field of oligoamine-biopolymere interactions.


Assuntos
Aminas/síntese química , Corantes Fluorescentes/síntese química , Inibidores da Agregação Plaquetária/síntese química , Aminas/farmacologia , Corantes Fluorescentes/farmacologia , Humanos , Técnicas In Vitro , Inibidores da Agregação Plaquetária/farmacologia
17.
Arch Pharm (Weinheim) ; 327(6): 399-404, 1994 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-8048847

RESUMO

Seventeen N,N'-benzene-1,3-dimethane and nine N,N',N''-benzene-1,3,5-trimethane derivatives with fluorescent properties have been synthesized. Three of them show antiplatelet activities (inducer collagen, IC50 Born-test) in concentrations < 10 mumol/L. They are suitable for interaction studies with biological macromolecules and synthetical and biological membranes. Structure activity relationships demonstrate that heteropolycyclic fluorophores i.e. quinoline, dibenzofurane, or carbazole are favorable substituents for this purpose.


Assuntos
Anticoagulantes/síntese química , Metilaminas/síntese química , Inibidores da Agregação Plaquetária/síntese química , Animais , Anticoagulantes/farmacologia , Metilaminas/farmacologia , Inibidores da Agregação Plaquetária/farmacologia , Ratos , Relação Estrutura-Atividade
18.
Arch Pharm (Weinheim) ; 325(4): 235-9, 1992 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-1530456

RESUMO

Eleven dimethanamines and one disydnonimine with fluorescent properties have been synthesized. All of them show antiplatelet activities (IC50, Born-test) in concentrations between 14-75 mumol/L. Five of them inhibited fibrin formation induced by thromboplastin by more than 75% in a 200 mu molar concentration. Both effect do not run parallel. The most space consuming fluorophores show the smallest inhibition of the platelet aggregation. Best results were obtained with an azulene, acenaphthene or naphthalene moiety between the two basic nitrogen functions.


Assuntos
Anticoagulantes/síntese química , Inibidores da Agregação Plaquetária/síntese química , Poliaminas/síntese química , Anticoagulantes/farmacologia , Fluorescência , Humanos , Técnicas In Vitro , Inibidores da Agregação Plaquetária/farmacologia , Poliaminas/farmacologia
19.
Z Orthop Ihre Grenzgeb ; 135(3): 258-60, 1997.
Artigo em Alemão | MEDLINE | ID: mdl-9334082

RESUMO

Bone changes of the upper extremity are rare manifestations of the M. Paget disease. Most frequently the disease affects the lower extremities, the pelvis followed by the calvarium and others. The rare asymptomatic, monostotic manifestation of Paget's disease of the left proximal ulnae of a 59 year old woman and the way of diagnosis is described. Symptomatic skeletal lesions are detected by radiological examination, bone scintigraphy reveals asymptomatic lesions. Laboratory tests (Alkaline serum phosphatase, Hydroxyproline in urine) monitor the activity of the disease.


Assuntos
Osteíte Deformante/diagnóstico , Ulna , Fosfatase Alcalina/sangue , Diagnóstico por Imagem , Feminino , Humanos , Hidroxiprolina/urina , Pessoa de Meia-Idade , Osteíte Deformante/patologia , Ulna/patologia
20.
Padiatr Grenzgeb ; 29(5): 405-14, 1990.
Artigo em Alemão | MEDLINE | ID: mdl-2122390

RESUMO

1. During the first six months after the admission to day-care acute infections of children are very frequent. This gives rise to the question for the justification of the indication of antibacterial chemotherapy during this period. 2. During the mentioned period all acute illnesses and the corresponding therapies of total 361 children in Berlin, the capital of the GDR, Leipzig and Schwedt are analysed. 3. The local differences of the appearance of the antibacterial chemotherapy are not caused by the type and frequency of the diagnosis, but reflect the inadequate consideration for the therapy recommendations given by the Society of Pädiatrics. 4. The correlations between antibacterial chemotherapy and the appearance of acute respiration illnesses (ARI) suggest the influence of the bacteria on the origin of these illnesses of day-cared children.


Assuntos
Antibacterianos/uso terapêutico , Creches , Controle de Infecções , Doença Aguda , Pré-Escolar , Infecção Hospitalar/prevenção & controle , Alemanha , Humanos , Lactente , Infecções/transmissão , Estudos Prospectivos
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