Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 52
Filtrar
1.
Phys Chem Chem Phys ; 23(13): 7837-7840, 2021 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-33200758

RESUMO

The effect of spatial dimensionality D on the near-threshold binding of small clusters of identical particles is shown. Estimates of the threshold coupling constants for 2 and N bosons are given for D equal to 1 to 5 and the relation to conditions for the Efimov effect is discussed. Variational trial functions for 4 identical spin-½ fermions in D = 2 are given.

2.
Gesundheitswesen ; 77(2): e15-9, 2015 Feb.
Artigo em Alemão | MEDLINE | ID: mdl-25714193

RESUMO

AIM OF THE STUDY: How can 2 pseudonymised data sets be linked? Using the example of data from the Berlin Myocardial Infarction Registry and from a German sickness fund (AOK Nordost) we will demonstrate how record linkage can be achieved without personal identifiers. METHODS: In different steps the method of deterministic record linkage with indirect identifiers: age, sex, hospital admission date and time, will be explained. RESULTS: We were able to show that 80.6% of the expected maximum number of patients were matched with our approach. As a result we had no duplicate matches in the linkage process, where one AOK patient was linked to 2 or more BMIR patients or vice versa. The matching variables produced enough uniqueness to be used as indirect patient identifiers. CONCLUSION: Deterministic record linkage with the following indirect indicators: age, sex, hospital admission date and time was possible in our study of patients with myocardial infarction in a circumscribed geographical region, which limited the number of cases and avoided mismatches.


Assuntos
Anonimização de Dados , Sistemas de Informação Hospitalar/estatística & dados numéricos , Registro Médico Coordenado/métodos , Infarto do Miocárdio/epidemiologia , Programas Nacionais de Saúde/estatística & dados numéricos , Sistema de Registros/estatística & dados numéricos , Adulto , Confiabilidade dos Dados , Feminino , Alemanha/epidemiologia , Hospitalização/estatística & dados numéricos , Humanos , Armazenamento e Recuperação da Informação/métodos , Armazenamento e Recuperação da Informação/estatística & dados numéricos , Masculino , Uso Significativo/estatística & dados numéricos , Pessoa de Meia-Idade , Infarto do Miocárdio/diagnóstico , Infarto do Miocárdio/terapia
3.
J Chem Phys ; 138(10): 104705, 2013 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-23514511

RESUMO

Diffraction and one-phonon inelastic scattering of a thermal energy helium atomic beam are evaluated in the situation that the target monolayer lattice is so dilated that the atomic beam penetrates to the interlayer region between the monolayer and the substrate. The scattering is simulated by propagating a wavepacket and including the effect of a feedback of the inelastic wave onto the diffracted wave, which represents a coherent re-absorption of the created phonons. Parameters are chosen to be representative of an observed p(1 × 1) commensurate monolayer solid of H2/NaCl(001) and a conjectured p(1 × 1) commensurate monolayer solid of H2/KCl(001). For the latter, there are cases where part of the incident beam is trapped in the interlayer region for times exceeding 50 ps, depending on the spacing between the monolayer and the substrate and on the angle of incidence. The feedback effect is large for cases of strong transient trapping.

4.
J Phys Chem A ; 115(25): 6882-7, 2011 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-21469671

RESUMO

It is shown that a commensurate square monolayer solid of Kr/NaCl(001) can be stabilized with a model incorporating a rather large energy corrugation amplitude. Then a square bilayer is formed under a compression and preempts the formation of an incommensurate triangular monolayer lattice. The lattice dynamics of the commensurate monolayer may be complex, because the modeling admits the possibility that it has a (2 × 2) unit cell with four Kr atoms.

5.
J Chem Phys ; 134(19): 194308, 2011 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-21599060

RESUMO

The one-phonon inelastic low energy helium atom scattering theory is adapted to cases where the target monolayer is a p(1 × 1) commensurate square lattice. Experimental data for para-H(2)/NaCl(001) are re-analyzed and the relative intensities of energy loss peaks in the range 6 to 9 meV are determined. The case of the H(2)/NaCl(001) monolayer for 26 meV scattering energy is computationally challenging and difficult because it has a much more corrugated surface than those in the previous applications for triangular lattices. This requires a large number of coupled channels for convergence in the wave-packet-scattering calculation and a long series of Fourier amplitudes to represent the helium-target potential energy surface. A modified series is constructed in which a truncated Fourier expansion of the potential is constrained to give the exact value of the potential at some key points and which mimics the potential with fewer Fourier amplitudes. The shear horizontal phonon mode is again accessed by the helium scattering for small misalignment of the scattering plane relative to symmetry axes of the monolayer. For 1° misalignment, the calculated intensity of the longitudinal acoustic phonon mode frequently is higher than that of the shear horizontal phonon mode in contrast to what was found at scattering energies near 10 meV for triangular lattices of Ar, Kr, and Xe on Pt(111).

6.
Clin Res Cardiol ; 109(1): 1-12, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31410547

RESUMO

Indications for TF-TAVI (transfemoral transcatheter aortic valve implantation) are rapidly changing according to increasing evidence from randomized controlled trials. Present trials document the non-inferiority or even superiority of TF-TAVI in intermediate-risk patients (STS-Score 4-8%) as well as in low-risk patients (STS-Score < 4%). However, risk scores exhibit limitations and, as a single criterion, are unable to establish an appropriate indication of TF-TAVI vs transapical TAVI vs SAVR (surgical aortic valve replacement). The ESC (European Society of Cardiology)/EACTS (European Association for Cardio-Thoracic Surgery) guidelines 2017 and the German DGK (Deutsche Gesellschaft für Kardiologie)/DGTHG (Deutsche Gesellschaft für Thorax-, Herz- und Gefäßchirurgie) commentary 2018 offer a framework for the selection of the best therapeutic method, but the individual decision is left to the discretion of the heart teams. An interdisciplinary TAVI consensus group of interventional cardiologists of the ALKK (Arbeitsgemeinschaft Leitende Kardiologische Krankenhausärzte e.V.) and cardiac surgeons has developed a detailed consensus on the indications for TF-TAVI to provide an up-to-date, evidence-based, comprehensive decision matrix for daily practice. The matrix of indication criteria includes age, risk scores, contraindications against SAVR (e.g., porcelain aorta), cardiovascular criteria pro TAVI, additional criteria pro TAVI (e.g., frailty, comorbidities, organ dysfunction), contraindications against TAVI (e.g., endocarditis) and cardiovascular criteria pro SAVR (e.g., bicuspid valve anatomy). This interdisciplinary consensus may provide orientation to heart teams for individual TAVI-indication decisions. Future adaptations according to evolving medical evidence are to be expected. Interdisciplinary consensus on indications for transfemoral transcatheter aortic valve implantation (TF-TAVI).


Assuntos
Estenose da Valva Aórtica/cirurgia , Substituição da Valva Aórtica Transcateter/métodos , Consenso , Artéria Femoral , Humanos , Seleção de Pacientes , Ensaios Clínicos Controlados Aleatórios como Assunto
7.
Science ; 224(4648): 506-8, 1984 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-6324345

RESUMO

In cats, infection with T-lymphotropic retroviruses can cause T-cell proliferation and leukemia or T-cell depletion and immunosuppression. In humans, some highly T4 tropic retroviruses called HTLV-I can cause T-cell proliferation and leukemia. The subgroup HTLV-II also induces T-cell proliferation in vitro, but its role in disease is unclear. Viruses of a third subgroup of human T-lymphotropic retroviruses, collectively designated HTLV-III, have been isolated from cultured cells of 48 patients with acquired immunodeficiency syndrome (AIDS). The biological properties of HTLV-III and immunological analyses of its proteins show that this virus is a member of the HTLV family, and that it is more closely related to HTLV-II than to HTLV-I. Serum samples from 88 percent of patients with AIDS and from 79 percent of homosexual men with signs and symptoms that frequently precede AIDS, but from less than 1 percent of heterosexual subjects, have antibodies reactive against antigens of HTLV-III. The major immune reactivity appears to be directed against p41, the presumed envelope antigen of the virus.


Assuntos
Síndrome da Imunodeficiência Adquirida/imunologia , Anticorpos Antivirais/análise , Deltaretrovirus/imunologia , Síndrome da Imunodeficiência Adquirida/microbiologia , Adulto , Antígenos Virais/imunologia , Pré-Escolar , Ensaio de Imunoadsorção Enzimática , Feminino , Homossexualidade , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Sarcoma de Kaposi/imunologia , Transtornos Relacionados ao Uso de Substâncias , Linfócitos T/microbiologia , Proteínas do Envelope Viral/imunologia
8.
J Phys Condens Matter ; 21(26): 264009, 2009 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-21828457

RESUMO

The ordering in a higher-order-commensurate monolayer solid of Pt(111)- (3 × 3)-4  N(2), which has coexisting physisorbed and weakly chemisorbed N(2) species, is analyzed with model calculations. Density functional theory calculations are also used to evaluate properties of chemisorbed N(2) in a (2 × 2) unit cell on Pt(111). The relation of these results to the orientational ordering of N(2) on other metal surfaces is discussed.

9.
J Phys Condens Matter ; 28(3): 035002, 2016 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-26704933

RESUMO

The physisorption of N2 molecules has long been a model system of molecular adsorption. We present a low-energy electron diffraction (LEED) study of the adsorption structures and thermodynamics of monolayer N2 on Pb(1 1 1). The results indicate that the monolayer structure has a triangular incommensurate center-of-mass lattice, and that the N2-substrate interaction is weaker than that observed on other metal surfaces. The N2 monolayer undergoes a phase transition between an orientationally ordered phase (low-temperature) and an orientationally disordered phase at a temperature of 20 K. Potential energy and quasiharmonic calculations indicate that the weak N2-Pb(1 1 1) interaction is the main contributing factor for the difference in orientational order of incommensurate N2 monolayers on Pb(1 1 1) and other similar metal surfaces.

10.
Dtsch Med Wochenschr ; 141(S 01): S48-S56, 2016 Oct.
Artigo em Alemão | MEDLINE | ID: mdl-27760450

RESUMO

The 2015 European Guidelines on Diagnosis and Treatment of Pulmonary Hypertension are also valid for Germany. While the guidelines contain detailed recommendations regarding pulmonary arterial hypertension (PAH), they contain only a relatively short paragraph on other, much more common forms of PH such as PH due to left heart disease. Despite the lack of data, targeted PAH treatments are increasingly being used for PH associated with left heart disease. This development is of concern because of limited ressources and the need to base treatments on scientific evidence. On the other hand, PH is a frequent problem that is highly relevant for morbidity and mortality in patients with left heart disease, representing an unmet need of targeted PH therapies. It that sense, the practical implementation of the European Guidelines in Germany requires the consideration of several specific issues and already existing novel data. This requires a detailed commentary to the guidelines, and in some aspects an update already appears necessary. In June 2016, a Consensus Conference organized by the PH working groups of the German Society of Cardiology (DGK), the German Society of Respiratory Medicine (DGP) and the German Society of Pediatric Cardiology (DGPK) was held in Cologne, Germany. This conference aimed to solve practical and controversial issues surrounding the implementation of the European Guidelines in Germany. To this end, several working groups were initiated, one of which was specifically dedicated to PH associated with left heart disease. This article summarizes the results and recommendations of this working group.


Assuntos
Cardiologia/normas , Hipertensão Pulmonar/terapia , Guias de Prática Clínica como Assunto , Pneumologia/normas , Disfunção Ventricular Direita/terapia , Medicina Baseada em Evidências , Alemanha , Humanos , Hipertensão Pulmonar/complicações , Hipertensão Pulmonar/diagnóstico , Resultado do Tratamento , Disfunção Ventricular Direita/diagnóstico , Disfunção Ventricular Direita/etiologia
11.
Circulation ; 101(20): 2388-92, 2000 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-10821815

RESUMO

BACKGROUND: The continuous infusion of prostacyclin has been shown to improve exercise capacity and survival in patients with primary pulmonary hypertension (PPH). Inhalation of iloprost, a stable analog of prostacyclin, might be an alternative therapy for PPH, selectively acting on the pulmonary vascular bed through ventilation-matched alveolar deposition of the drug. We investigated the short-term effects of iloprost inhalation on exercise capacity and gas exchange in patients with PPH. METHODS AND RESULTS: In 11 patients with PPH, we performed 2 consecutive cardiopulmonary exercise tests before and after the inhalation of 17 microgram of iloprost. Patients had marked pulmonary hypertension (mean pulmonary artery pressure 65 mm Hg), and inhalation resulted in a decrease in pulmonary vascular resistance (1509 versus 1175 dyne. s(-1). cm(-5), P<0.05). Arterial blood gases remained unchanged (PaO(2) 69.3 versus 66.8 mm Hg; PaCO(2) 29.6 versus 28.8 mm Hg). Iloprost significantly (P<0.05) improved exercise duration (379 versus 438 seconds), peak oxygen uptake (12.8 versus 14.2 mL. kg(-1). min(-1)), VE-versus-V CO(2) slope (58 versus 51.4). CONCLUSIONS: The present data show that iloprost inhalation exerts pulmonary vasodilatation and improves symptoms and exercise capacity in patients with PPH. The data also suggest that iloprost inhalation is a suitable treatment for PPH. Whether these effects are maintained during long-term treatment and are paralleled by improvement in prognosis remains to be determined.


Assuntos
Hipertensão Pulmonar/tratamento farmacológico , Hipertensão Pulmonar/fisiopatologia , Iloprosta/administração & dosagem , Resistência Física/efeitos dos fármacos , Respiração/efeitos dos fármacos , Vasodilatadores/administração & dosagem , Administração por Inalação , Adulto , Teste de Esforço , Coração/fisiopatologia , Hemodinâmica/efeitos dos fármacos , Humanos , Iloprosta/uso terapêutico , Pulmão/fisiopatologia , Pessoa de Meia-Idade , Vasodilatadores/uso terapêutico
12.
Endocrinology ; 111(3): 737-42, 1982 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-7049672

RESUMO

Insulin stimulates the production of superoxide and hydrogen peroxide in various tissues. Hydrogen peroxide has been proposed to be an intracellular second messenger for insulin and a moderator of cellular proliferation and differentiation. We previously found that cell proliferation is increased in small intestinal mucosa of streptozotocin-diabetic rats. The current study was undertaken to determine if superoxide dismutase (SOD), the enzyme that converts superoxide to hydrogen peroxide, is altered in the mucosa of the alimentary tract and renal cortex of the diabetic rat, and if so, whether SOD responds to insulin treatment. Total SOD and cyanide-insensitive [manganese-containing SOD (Mn SOD)] SOD were measured by the nitroblue tetrazolium inhibition assay. We studied ad libitum fed animals, where diabetics are hyperphagic and pair-fed animals, where hyperphagia is not present. Since cyclic nucleotides appear to control cell proliferation in some tissues, we also measured cAMP and cGMP in mucosa of the small intestine. In ad libitum fed animals, total SOD was depressed in the mucosa of duodenum, jejunum, and ileum, but not in the cecum or colon of the streptozotocin-diabetic rats. The level of Mn-SOD was not affected by diabetes or insulin treatment, but the cyanide-sensitive [copper- and zinc containing SOD (Cu-Zn SOD] SOD was depressed in the small intestine and colon of diabetic rats. Insulin treatment restored total and Cu-Zn SOD activity in the small intestine to normal and increased Cu-Zn SOD activity in the colon to normal. Pair-fed animals showed the same changes in the SOD activity of jejunal mucosa that were found in ad libitum fed animals. In renal cortex, diabetes did not alter total SOD, but increased Mn SOD and decreased Cu-Zn SOD. Both responses were reversed by insulin treatment. Cyclic nucleotide concentrations were not affected by diabetes. We conclude that SOD enzymes re altered in diabetes, at least in proliferating tissues. Responses are tissue specific. The mucosa of the small intestine and colon show decreased Cu-Zn SOD, the SOD of the cecum is unaffected, and the kidney shows increased Mn SOD and decreased Cu-Zn SOD. The SOD responses of diabetics are reversed by insulin treatment.


Assuntos
Diabetes Mellitus Experimental/enzimologia , Intestinos/enzimologia , Superóxido Dismutase/metabolismo , Animais , Glicemia/análise , Cobre/metabolismo , Diabetes Mellitus Experimental/tratamento farmacológico , Alimentos , Insulina/uso terapêutico , Masculino , Manganês/metabolismo , Ratos , Ratos Endogâmicos , Zinco/metabolismo
13.
Arch Neurol ; 58(2): 265-9, 2001 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11176965

RESUMO

BACKGROUND: The dysarthria of progressive supranuclear palsy consists of prominent hypokinetic and spastic components with less prominent ataxic components. OBJECTIVE: To correlate the types of dysarthria with neuropathological changes in patients with progressive supranuclear palsy. DESIGN AND METHODS: In 14 patients with progressive supranuclear palsy, we correlated the perceptual speech findings with the neuropathological findings. A dysarthria assessment was performed a mean +/- SD of 31 +/- 15 months (range, 10-53 months) before death. The deviant speech dimensions were rated on a scale of 0 (normal) to 3 (severe). The neuropathological examination consisted of semiquantitative analysis of neuronal loss and gliosis by investigators (A.A.F.S., and L.A.B.) blinded to the clinical findings. Correlation and linear regression analysis were used to correlate the severity of the hypokinetic, spastic, and ataxic components with the degree of neuronal loss and gliosis in predetermined anatomical sites. RESULTS: All patients had hypokinetic and spastic dysarthria, and 9 also had ataxic components. The severity of the hypokinetic components was significantly correlated with the degree of neuronal loss and gliosis in the substantia nigra pars compacta (r = 0.61, P =.02) and pars reticulata (r = 0.64, P =.01) but not in the subthalamic nucleus (r = 0.51, P =.07) or the striatum or globus pallidus (/r/<0.34, P>.20). The severity of the spastic and ataxic components was not significantly correlated with the neuropathological changes in the frontal cortex (r = 0.20, P =.50) and cerebellum (/r/<0.28, P>.33), respectively. CONCLUSION: The hypokinetic dysarthria of progressive supranuclear palsy may result from degenerative changes in the substantia nigra pars compacta and pars reticulata and not from changes in the striatum or globus pallidus.


Assuntos
Corpo Estriado/patologia , Disartria/diagnóstico , Substância Negra/patologia , Núcleo Subtalâmico/patologia , Paralisia Supranuclear Progressiva/patologia , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Modelos Lineares , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos
14.
Hum Pathol ; 32(10): 1102-8, 2001 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11679945

RESUMO

Composite extrarenal rhabdoid tumors (CERTs) represent a diverse group of neoplasms with rhabdoid shape in combination with one of several distinctive tumor types. Like the classic renal and extrarenal malignant rhabdoid tumor (MRT), as well as the atypical teratoid/rhabdoid tumor (AT/RT) of the central nervous system, CERTs typically show aggressive clinical behavior. Deletions and mutations of the INII gene on 22q11.2 have been identified in most classic MRTs and AT/RTs; however, it is not known whether the rhabdoid components in CERTs have similar genetic abnormalities. Using fluorescence in situ hybridization (FISH) on archival, paraffin-embedded tissue with a commercially available probe in close proximity to the INII locus (bcr), as well as other chromosome 22 probes, we studied 4 cases of MRT, 13 of AT/RT, and 16 of CERT (3 melanoma, 4 meningioma, 7 carcinoma, 1 rhabdomyosarcoma, and 1 neuroblastoma). Deletion of the 22q11.2 locus was demonstrated in 10 (77%) of 13 AT/RTs and 3 (75%) of 4 MRT, including 1 congenital MRT. Of the 16 CERTs, only 2 (a rhabdoid meningioma and a carcinoma with rhabdoid features; 13%) harbored a deletion at this locus. This difference was statistically significant (P <.001). We conclude that deletion of 22q11.2, typical of most classic MRTs and AT/RTs, is infrequently seen in CERTs. This suggests that the rhabdoid component of CERTs does not evolve by way of the genetic alteration characteristic of MRTs or AT/RTs, but represents instead a distinct phenotype shared by a number of tumors as they undergo anaplastic progression.


Assuntos
Cromossomos Humanos Par 22 , Dosagem de Genes , Neoplasias/genética , Tumor Rabdoide/genética , Teratoma/genética , Adolescente , Adulto , Idoso , Biomarcadores Tumorais/análise , Pré-Escolar , Mapeamento Cromossômico , Células Clonais , Feminino , Deleção de Genes , Humanos , Imuno-Histoquímica , Hibridização in Situ Fluorescente , Lactente , Recém-Nascido , Masculino , Pessoa de Meia-Idade , Proteínas de Neoplasias/análise , Neoplasias/química , Neoplasias/patologia , Neoplasias/cirurgia , Fenótipo , Tumor Rabdoide/química , Tumor Rabdoide/patologia , Tumor Rabdoide/cirurgia , Teratoma/química , Teratoma/patologia , Teratoma/cirurgia
15.
Hum Pathol ; 32(2): 156-62, 2001 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11230702

RESUMO

It has been postulated that infants with medulloblastomas/central primitive neuroectodermal tumors (MB/PNET) may fare worse than older patients because some of them harbor unrecognized atypical teratoid/rhabdoid tumors (AT/RT), rare intracranial neoplasms that are typically unresponsive to therapy and rapidly fatal. Although small primitive cells are common to both entities, chromosome 22q11.2 deletions are common only in AT/RTs. Using fluorescence in situ hybridization (FISH) on archival, paraffin-embedded biopsy tissue with commercially available probes to 22q11.2, the region associated with RTs, we studied 8 cases of AT/RT, 12 cases of MB/PNET, and 4 cases of primitive central nervous system (CNS) neoplasms, which were difficult to classify. 22q Deletions were identified in 6 of 8 (75%) conventional AT/RTs and 0 of 12 (0%) children with classic MB/PNET. Of the 4 originally "difficult to classify" cases, 3 had deletions of 22q. In light of the FISH results, review of the morphology and immunophenotype resulted in 3 tumors being reclassified as AT/RTs and 1 as a large cell MB. These 4 cases highlight the potential diagnostic use of FISH for selected cases of primitive CNS malignancies in children and substantiate the notion that misdiagnosed AT/RTs may, in part account for the worse prognosis associated with "MB/PNET" in children younger than 2 years of age.


Assuntos
Neoplasias do Sistema Nervoso Central/diagnóstico , Cromossomos Humanos Par 22 , Hibridização in Situ Fluorescente/métodos , Meduloblastoma/diagnóstico , Tumores Neuroectodérmicos Primitivos/diagnóstico , Tumor Rabdoide/diagnóstico , Teratoma/diagnóstico , Adolescente , Neoplasias do Sistema Nervoso Central/química , Neoplasias do Sistema Nervoso Central/genética , Criança , Pré-Escolar , Diagnóstico Diferencial , Feminino , Humanos , Lactente , Masculino , Meduloblastoma/química , Meduloblastoma/genética , Tumores Neuroectodérmicos Primitivos/química , Tumores Neuroectodérmicos Primitivos/genética , Prognóstico , Tumor Rabdoide/química , Tumor Rabdoide/genética , Teratoma/química , Teratoma/genética
16.
Chest ; 117(4): 968-75, 2000 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-10767226

RESUMO

STUDY OBJECTIVES: Diffusion impairment and reduced performance in cardiopulmonary exercise testing (CPX) have been found in patients after heart transplantation. The pathogenesis of these abnormalities is unclear. In particular, the contribution of pulmonary interstitial changes has not yet been verified. DESIGN: We analyzed pulmonary function tests, high-resolution CT (HRCT), echocardiography, left heart catheterization, and CPX in transplanted patients. PATIENTS: Forty long-term survivors were studied at a median of 47 months (range, 12 to 89 months) after heart transplantation. RESULTS: Diffusion was impaired in 40% (transfer factor for carbon monoxide) or 82.5% (carbon monoxide transfer coefficient) of the patients. Diffusion impairment was caused by a decreased diffusing capacity of the alveolar capillary membrane in 89% and/or by a decreased blood volume of the alveolar capillaries in 46% of cases. In five patients (12.5%), CT revealed interstitial lung changes. These patients did not have different values of diffusion capacity. Maximal oxygen uptake and ventilatory efficiency during exercise (minute ventilation/carbon dioxide output slope) were impaired in 92% and 46% of the cases, respectively. CONCLUSIONS: Our data show that the diffusion abnormalities are caused by an impaired diffusion status of the alveolar capillary membrane. Interstitial changes detectable in HRCT were found not to be involved in this process. The reduced performance in CPX in our long-term survivors is caused by pulmonary perfusion abnormalities and low tidal volume, which is due to the deconditioning of respiratory muscle, rather than by interstitial changes or diffusion abnormalities.


Assuntos
Tolerância ao Exercício/fisiologia , Transplante de Coração/efeitos adversos , Pneumopatias/fisiopatologia , Capacidade de Difusão Pulmonar/fisiologia , Adulto , Cateterismo Cardíaco , Ecocardiografia , Teste de Esforço , Feminino , Ventrículos do Coração/diagnóstico por imagem , Ventrículos do Coração/fisiopatologia , Humanos , Pneumopatias/diagnóstico por imagem , Pneumopatias/etiologia , Masculino , Pessoa de Meia-Idade , Contração Miocárdica , Prognóstico , Estudos Retrospectivos , Volume Sistólico , Tomografia Computadorizada por Raios X
17.
J Heart Lung Transplant ; 18(12): 1243-5, 1999 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-10612386

RESUMO

This is a case report about a 56-year-old female patient with primary pulmonary hypertension who underwent single, right lung transplantation. Five years postoperatively she developed signs of right heart failure. History and physical examination suggested pulmonary artery stenosis. Diagnosis was confirmed by pulmonary angiography. Percutaneous placement of a balloon expandable stent normalized pulmonary artery pressure.


Assuntos
Hipertensão Pulmonar/cirurgia , Transplante de Pulmão , Artéria Pulmonar/patologia , Pressão Sanguínea , Constrição Patológica , Feminino , Humanos , Pessoa de Meia-Idade , Complicações Pós-Operatórias , Artéria Pulmonar/fisiopatologia , Stents , Fatores de Tempo
18.
J Clin Pathol ; 57(11): 1172-8, 2004 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-15509679

RESUMO

BACKGROUND: Cytogenetic studies of malignant peripheral nerve sheath tumours (MPNSTs) and malignant triton tumours (MTTs) are rare. AIMS: To undertake cytogenetic analysis of these tumours. METHODS: Conventional cytogenetic analysis of 21 MPNSTs and MTTs from 17 patients (nine with peripheral neurofibromatosis (NF1)) was carried out using standard culture and harvesting procedures. For a more precise identification of composite structural rearrangements and marker chromosomes, spectral karyotypic analysis (SKY) was applied to a subset of cases. In addition, EGFR gene copy number was assessed by fluorescence in situ hybridisation (FISH) analysis in a subset of cases. RESULTS: Cytogenetic analysis revealed predominantly complex karyotypes. SKY analysis was useful in further defining many structural anomalies. Structural aberrations most frequently involved chromosomal bands or regions 1p31-36, 4q28-35, 7p22, 11q22-23, 19q13, 20q13, and 22q11-13. Overall, loss of chromosomal material was much more common than gain. Loss of chromosomes or chromosomal regions 1p36 (48%), 3p21-pter (52%), 9p23-pter (57%), 10 (48%), 11q23-qter (48%), 16/16q24 (62%), 17(43%), and 22/22q (48%), and gains of 7/7q (29%) and 8/8q (29%) were most prominent. These gains and losses were distributed equally between MPNST and MTT, demonstrating that these entities are similar with respect to recurrent genomic imbalances. Similarly, none of the recurrent chromosomal breakpoints or imbalances was restricted to either NF1 associated or sporadic MPNSTs. FISH analysis was negative for amplification. CONCLUSIONS: These cytogenetic and molecular cytogenetic findings expand the knowledge of chromosomal alterations in MPNST and MTT, and point to possible recurring regions of interest.


Assuntos
Aberrações Cromossômicas , Neoplasias de Bainha Neural/genética , Adolescente , Adulto , Idoso , Transformação Celular Neoplásica/genética , Deleção Cromossômica , Feminino , Amplificação de Genes/genética , Humanos , Hibridização in Situ Fluorescente/métodos , Cariotipagem/métodos , Masculino , Pessoa de Meia-Idade , Neurofibromatose 1/genética , Rabdomiossarcoma/genética , Translocação Genética/genética
19.
Metabolism ; 32(7 Suppl 1): 156-61, 1983 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-6865766

RESUMO

Cryopreservation of BB rat embryos would ensure perpetuation, at greatly reduced cost, of this model of nonobese, insulin-dependent, juvenile-onset diabetes in man. Immature prediabetic female BB rats were ovulated hormonally. The embryos were removed at the 8- to 16 cell and blastocyst stages and cryopreserved, and after thawing were assayed for viability in vitro or transplanted into pseudopregnant foster mothers of a nondiabetic strain. The highest rate of viability in vitro (100%) and development into normal fetuses (31%) was obtained with blastocysts transplanted into day-4 foster mothers. The results indicate the feasibility of low-temperature banking of this clinically important strain of rats.


Assuntos
Embrião de Mamíferos , Congelamento , Gravidez em Diabéticas , Preservação Biológica/métodos , Animais , Diabetes Mellitus Experimental , Diabetes Mellitus Tipo 1 , Transferência Embrionária , Feminino , Indução da Ovulação , Gravidez , Ratos , Ratos Endogâmicos
20.
Brain Res ; 806(2): 141-51, 1998 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-9739127

RESUMO

We have developed a model of autonomic nervous system aging using the mouse superior cervical sympathetic ganglion (SCG) which is characterized by the reproducible development of distinctive, markedly-enlarged neuritic swellings (vacuolar neuritic dystrophy, VND). These structures contained an admixture of lucent vacuoles and subcellular organelles, and involved both presynaptic and postsynaptic ganglionic elements. Quantitation of the frequency of VND was accomplished at the light microscopic level and validated by ultrastructural examination. VND lesions were 30-100-fold more frequent in the aged mouse paravertebral SCG than in the prevertebral celiac/superior mesenteric (C/SMG) sympathetic ganglia. Although VND was identified in all ages of mice examined, the number of lesions increased significantly with age. The frequency of VND was a function of the strain of mouse examined with a 40-fold difference in VND frequency between C57BL6 mice, the least involved strain, and the DBA/2J strain, which was most affected and began to develop significant numbers of lesions at an early age. As in our human studies of aging in the sympathetic nervous system, there was a prominent gender effect with males developing twofold greater numbers of VND lesions than females. Mice maintained on a significant calorie restricted diet for 30 months developed 70% fewer lesions than ad libitum-fed, age and sex matched controls. The aging mouse SCG, therefore, represents a robust animal model with reproducible, quantifiable and unambiguous neuropathology. Insights into pathogenetic mechanisms gained in the subsequent analysis of this relatively simple peripheral sympathetic nervous system model may contribute to the understanding of some of the most complex and significant problems involving higher brain function.


Assuntos
Envelhecimento/fisiologia , Pescoço/inervação , Neuritos/patologia , Distrofias Neuroaxonais/patologia , Gânglio Cervical Superior/patologia , Vacúolos/patologia , Animais , Ingestão de Energia , Feminino , Masculino , Camundongos , Camundongos Endogâmicos , Caracteres Sexuais , Especificidade da Espécie , Gânglio Cervical Superior/ultraestrutura
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA