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1.
Am J Transplant ; 12(8): 1988-96, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22682114

RESUMO

Public reports of organ transplant program outcomes by the US Scientific Registry of Transplant Recipients have been both groundbreaking and controversial. The reports are used by regulatory agencies, private insurance providers, transplant centers and patients. Failure to adequately adjust outcomes for risk may cause programs to avoid performing transplants involving suitable but high-risk candidates and donors. At a consensus conference of stakeholders held February 13-15, 2012, the participants recommended that program-specific reports be better designed to address the needs of all users. Additional comorbidity variables should be collected, but innovation should also be protected by excluding patients who are in approved protocols from statistical models that identify underperforming centers. The potential benefits of hierarchical and mixed-effects statistical methods should be studied. Transplant centers should be provided with tools to facilitate quality assessment and performance improvement. Additional statistical methods to assess outcomes at small-volume transplant programs should be developed. More data on waiting list risk and outcomes should be provided. Monitoring and reporting of short-term living donor outcomes should be enhanced. Overall, there was broad consensus that substantial improvement in reporting outcomes of transplant programs in the United States could and should be made in a cost-effective manner.


Assuntos
Transplante de Órgãos , Garantia da Qualidade dos Cuidados de Saúde , Humanos , Doadores Vivos
4.
Am J Transplant ; 9(4): 719-26, 2009 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-19344463

RESUMO

In a retrospective, single-center cohort study, outcomes of infants and toddlers undergoing lung transplant at St. Louis Children's Hospital between 1990 and 2004 were compared to older children. Patients with cystic fibrosis (exclusively older children) and those who underwent heart-lung, liver-lung, single lung or a second transplantation were excluded from comparisons. One hundred nine lung transplants were compared. Thirty-six were in infants <1 year old, 26 in toddlers 1-3 years old and 47 in children >3 years old. Graft survival was similar for infants and toddlers (p = 0.35 and p = 0.3, respectively) compared to children over 3 years old at 1 and 3 years after transplant. Significantly more infants (p < 0.0001 and p = 0.003) and toddlers (p = 0.002 and p = 0.03) were free from acute rejection and bronchiolitis obliterans compared to older patients. While most infants and toddlers had only minimal lung function impairment, and achieved normal to mildly delayed developmental scores, somatic growth remained depressed 5 years after transplant. Lung transplantation in infants and young children carries similar survival rates to older children and adults. Further insights into the unique immunologic aspects of this group of patients may elucidate strategies to prevent acute and chronic rejection in all age groups.


Assuntos
Hospitais Pediátricos/estatística & dados numéricos , Transplante de Pulmão/estatística & dados numéricos , Adolescente , Adulto , Fatores Etários , Desenvolvimento Infantil , Pré-Escolar , Estudos de Coortes , Oxigenação por Membrana Extracorpórea/estatística & dados numéricos , Feminino , Seguimentos , Rejeição de Enxerto/epidemiologia , Rejeição de Enxerto/prevenção & controle , Sobrevivência de Enxerto , Transtornos do Crescimento/epidemiologia , Humanos , Lactente , Pneumopatias/classificação , Pneumopatias/cirurgia , Transplante de Pulmão/efeitos adversos , Transplante de Pulmão/mortalidade , Masculino , Missouri , Taxa de Sobrevida , Sobreviventes
5.
Am J Transplant ; 9(4 Pt 2): 942-58, 2009 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-19341417

RESUMO

This article highlights trends and changes in lung and heart-lung transplantation in the United States from 1998 to 2007. The most significant change over the last decade was implementation of the Lung Allocation Score (LAS) allocation system in May 2005. Subsequently, the number of active wait-listed lung candidates declined 54% from pre-LAS (2004) levels to the end of 2007; there was also a reduction in median waiting time, from 792 days in 2004 to 141 days in 2007. The number of lung transplants performed yearly increased through the decade to a peak of 1 465 in 2007; the greatest single year increase occurred in 2005. Despite candidates with increasingly higher LAS scores being transplanted in the LAS era, recipient death rates have remained relatively stable since 2003 and better than in previous years. Idiopathic pulmonary fibrosis became the most common diagnosis group to receive a lung transplant in 2007 while emphysema was the most common diagnosis in previous years. The number of retransplants and transplants in those aged > or =65 performed yearly have increased significantly since 1998, up 295% and 643%, respectively. A decreasing percentage of lung transplant recipients are children (3.5% in 2007, n = 51). With LAS refinement ongoing, monitoring of future impact is warranted.


Assuntos
Transplante de Coração-Pulmão/estatística & dados numéricos , Transplante de Pulmão/estatística & dados numéricos , Listas de Espera , Adulto , Distribuição por Idade , Cateterismo Cardíaco/estatística & dados numéricos , Criança , Enfisema/epidemiologia , Enfisema/cirurgia , Transplante de Coração-Pulmão/mortalidade , Humanos , Transplante de Pulmão/mortalidade , Fibrose Pulmonar/epidemiologia , Fibrose Pulmonar/cirurgia , Sistema de Registros , Alocação de Recursos/estatística & dados numéricos , Análise de Sobrevida , Sobreviventes , Estados Unidos , United States Dept. of Health and Human Services
6.
J Cell Biol ; 107(6 Pt 1): 2243-51, 1988 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-3198685

RESUMO

To investigate the function of calmodulin (CaM) in the mitotic apparatus, the effect of microinjected CaM and chemically modified CaMs on nocodazole-induced depolymerization of spindle microtubules was examined. When metaphase PtK1 cells were microinjected with CaM or a CaM-TRITC conjugate, kinetochore microtubules (kMTs) were protected from the effect of nocodazole. The ability of microinjected CaM to subsequently protect kMTs from the depolymerizing effect of nocodazole was dose dependent, and was effective for approximately 45 min, with protection decreasing if nocodazole treatment was delayed for more than 60 min after injection of CaM. The CaM-TRITC conjugate, similar to native CaM, displayed the ability to activate bovine brain CaM-dependent adenylate cyclase in a Ca++-dependent manner and showed a Ca++-dependent mobility shift when subjected to PAGE. A heat-altered CaM-TRITC conjugate also protected kMTs from the effect of nocodazole. However, this modified CaM was not able to activate adenylate cyclase nor did it display a Ca++-dependent mobility shift when electrophoresed. In a permeabilized cell model system, both CaM analogs were observed to bind to the spindle in a Ca++-independent manner. In contrast, a performic acid-oxidized CaM did not have a protective effect on spindle structure when microinjected into metaphase cells before nocodazole treatment. The oxidized CaM did not activate adenylate cyclase and did not exhibit Ca++-dependent mobility on polyacrylamide gels. These results are interpreted as supporting the hypothesis that CaM binds to the mitotic spindle in a Ca++-independent manner and that CaM may serve in the spindle, at least in part, to stabilize kMTs.


Assuntos
Benzimidazóis/farmacologia , Calmodulina/farmacologia , Fuso Acromático/fisiologia , Animais , Cálcio/farmacologia , Calmodulina/análogos & derivados , Linhagem Celular , Microinjeções , Microscopia Eletrônica , Microtúbulos/ultraestrutura , Nocodazol , Fuso Acromático/efeitos dos fármacos , Fuso Acromático/ultraestrutura , Relação Estrutura-Atividade , Tubulina (Proteína)/metabolismo
7.
Am J Transplant ; 8(12): 2491-5, 2008 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-18976303

RESUMO

Children, especially those under 5 years of age, have the highest death rate on the transplant waiting list compared to any other age range. This article discusses the concept, supported by OPTN data, that there is an age range of small pediatric donors, which are almost exclusively transplanted into small pediatric transplant candidates. Allocation policies that allow broader sharing of small pediatric donors into small pediatric candidates are likely to decrease death rates of children on the waiting list. As well, although the number of pediatric deceased donors continues to decline, improving consent rates for eligible pediatric donors, and judicious use of pediatric donors after cardiac death, can enhance the pediatric deceased donor supply.


Assuntos
Mortalidade da Criança , Transplante de Órgãos , Transplante/mortalidade , Listas de Espera , Adolescente , Criança , Pré-Escolar , Humanos , Lactente , Recém-Nascido , Doadores de Tecidos , Obtenção de Tecidos e Órgãos , Estados Unidos/epidemiologia
8.
Eur J Cell Biol ; 47(1): 88-93, 1988 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-3068060

RESUMO

To investigate the association of calmodulin (CaM) with microtubules (MTs) in the mitotic apparatus (MA), the distributions of both CaM and tubulin were examined in mitotic PtK1 cells in which MT subclasses had been selectively removed or altered by treatment with cold or with the MT inhibitor, nocodazole. A fluorescent CaM conjugate with tetramethylrhodamine isothiocyanate (CaM-TRITC) was microinjected into living cells, and the CaM distribution in the living cell was compared to the distribution of MTs indicated by tubulin immunofluorescence. In cells which had been treated for 2 h at 0 to 4 degrees C or with a low (0.03 micrograms/ml) dose of nocodazole, the only MTs remaining appeared to be kinetochore MTs (kMTs). The distribution of microinjected CaM-TRITC in these cells was indistinguishable from that found in untreated cells and appeared to be colocalized with the kMTs. In cells which were treated with a high (3.0 micrograms/ml) dose of nocodazole, only short MTs remained. When CaM-TRITC was injected into these cells, it formed a somewhat punctate distribution near the chromosomes and, after tubulin immunofluorescence processing, colocalized with what appeared to be remnants of kMTs. We believe that these observations support the hypothesis that CaM exists in the MA in a structural association with kMTs.


Assuntos
Benzimidazóis/farmacologia , Calmodulina/metabolismo , Temperatura Baixa , Microtúbulos/metabolismo , Animais , Calmodulina/farmacologia , Linhagem Celular , Relação Dose-Resposta a Droga , Imunofluorescência , Microscopia Eletrônica , Microtúbulos/efeitos dos fármacos , Microtúbulos/ultraestrutura , Nocodazol , Fuso Acromático/efeitos dos fármacos , Fuso Acromático/metabolismo , Fuso Acromático/ultraestrutura
9.
J Immunol Methods ; 136(1): 31-6, 1991 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-1995710

RESUMO

In general, antigen affinity columns made with commercially prepared activated affinity supports bind antibody specific for the coupled antigen. Nonetheless, in some cases affinity purification may yield antibodies to molecules other than the molecule of interest. In this report, we demonstrate such an occurrence: an antibody which adsorbs to an Affi-Prep 10 affinity matrix was found in the serum of sheep immunized against calmodulin. The contaminating antibody bound to cell nuclei and condensed chromosomes; the composition of the Affi-Prep 10 matrix suggests that the antibody may cross-react to the sugar-phosphate backbone of DNA. We were able to remove the contaminating antibody from the anti-calmodulin by passing the affinity-purified mixture over an antigen-free Affi-Prep 10 column.


Assuntos
Anticorpos/isolamento & purificação , Calmodulina/imunologia , Animais , Anticorpos/imunologia , Cromatografia de Afinidade , Reações Cruzadas , Ratos , Ovinos
10.
J Thorac Cardiovasc Surg ; 118(5): 796-804, 1999 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-10534684

RESUMO

INTRODUCTION: Established successes with adult lung transplantation have laid the foundation for extension of this therapeutic modality to infants and children dying of end-stage pulmonary disease. The purpose of this report is to convey our experience with 19 infants undergoing lung transplantation before the age of 6 months. METHODS: Six patients with predominantly pulmonary vascular disease and 13 patients with primarily pulmonary parenchymal disease have undergone bilateral sequential lung transplantation at our institution since 1990. Mean age at transplant was 104 +/- 44 days, and mean weight was 4.9 +/- 1.6 kg. RESULTS: Although early mortality (32%, 6/19) was higher than that previously reported for older pediatric age groups, long-term survival was similar (44% at a maximum follow-up of 6 years). Although anastomotic complications and infections occurred at a rate approximating that seen in older pediatric age groups, episodes of acute rejection appear to occur with decreased frequency. Similarly, at a mean follow-up of 3 years, only 2 (15%) of 13 long-term survivors have evidence of bronchiolitis obliterans. The functional residual capacity, as measured on infant pulmonary function tests, has gradually increased as the children have grown, suggesting that lung growth is occurring. CONCLUSIONS: Bilateral lung transplantation is a viable alternative in infants dying of end-stage pulmonary disease. Efforts directed toward avoiding the complications that lead to early posttransplant mortality combined with the seemingly lower incidence of early and late rejection may provide long-term results better than those in other age groups.


Assuntos
Pneumopatias/cirurgia , Transplante de Pulmão , Análise Atuarial , Seguimentos , Rejeição de Enxerto/epidemiologia , Humanos , Terapia de Imunossupressão , Lactente , Pneumopatias/mortalidade , Transplante de Pulmão/mortalidade , Transplante de Pulmão/estatística & dados numéricos , Complicações Pós-Operatórias/epidemiologia , Pneumopatia Veno-Oclusiva/mortalidade , Pneumopatia Veno-Oclusiva/cirurgia , Fatores de Tempo
11.
J Thorac Cardiovasc Surg ; 115(2): 404-13; discussion 413-4, 1998 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-9475536

RESUMO

OBJECTIVE: This paper was undertaken to review the experience at our institution with bilateral sequential lung transplantation for cystic fibrosis. METHODS: Since 1989, 103 bilateral sequential lung transplants for cystic fibrosis have been performed (46 pediatric, 48 adult, 9 redo); the mean age was 21 +/- 10 years. Cardiopulmonary bypass was used in all but one pediatric (age <18) transplant, and in 15% of adults. RESULTS: Hospital mortality was 4.9%, with 80% of early deaths related to infection. Bronchial anastomotic complications occurred with equal frequency in the pediatric and the adult populations (7.3%). One- and 3-year actuarial survival are 84% and 61%, respectively (no significant difference between pediatric and adult age groups; average follow-up 2.1 +/- 1.6 years). Mean forced expiratory volume in 1 second increased from 25% +/- 9% before transplantation to 79% +/- 35% 1 year after transplantation. Acute rejection occurred 1.7 times per patient-year, with most episodes taking place within the first 6 months after transplantation. The need for treatment of lower respiratory tract infections occurred 1.2 times per patient in the first year after transplantation. Actuarial freedom from bronchiolitis obliterans was 63% at 2 years and 43% at 3 years. Redo transplantation was performed only in the pediatric population and was associated with an early mortality of 33%. Eight living donor transplants (four primary transplants, four redo transplants) were performed with an early survival of 87.5%. CONCLUSION: Patients with end-stage cystic fibrosis can undergo bilateral lung transplantation with morbidity and mortality comparable to that seen in pulmonary transplantation for other disease entities.


Assuntos
Fibrose Cística/cirurgia , Transplante de Pulmão , Análise Atuarial , Adolescente , Adulto , Anti-Infecciosos/uso terapêutico , Criança , Contraindicações , Fibrose Cística/mortalidade , Fibrose Cística/fisiopatologia , Feminino , Humanos , Imunossupressores/uso terapêutico , Transplante de Pulmão/métodos , Transplante de Pulmão/mortalidade , Masculino , Pessoa de Meia-Idade , Seleção de Pacientes , Testes de Função Respiratória , Análise de Sobrevida , Resultado do Tratamento
12.
Ann Thorac Surg ; 59(4): 813-20; discussion 820-1, 1995 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-7695402

RESUMO

Single or bilateral lung transplantation was performed in 20 patients with pulmonary hypertension or an inadequate pulmonary vascular bed; all but 1 had congenital heart disease. The average age was 6.3 years (range, 3 months to 23.9 years). All were in New York Heart Association class IV, and 6 were hospitalized and receiving intensive support before transplantation. Hospital survival was 70% (14/20), with three additional deaths at 7, 11, and 27 months. A prior thoracic operation contributed to three of six hospital deaths from hemorrhage. All late deaths were due directly or indirectly to obliterative bronchiolitis. At a mean follow-up of 19 months (range, 2 to 48 months), 10 of 11 survivors are in New York Heart Association class I. Survival after hospital discharge and incidence of obliterative bronchiolitis are similar in a contemporary group of 41 patients of comparable age who underwent lung transplantation for pulmonary disease (p = not significant). Single or bilateral lung transplantation is an acceptable therapy for children with pulmonary hypertension, congenital heart disease, or both. Further investigation in the areas of pretransplantation survival, operative risk factors, and long-term outcome of single-lung recipients and recipients with hemodynamically insignificant intracardiac lesions are needed to develop optimal decision-making strategies for these patients.


Assuntos
Cardiopatias Congênitas/cirurgia , Hipertensão Pulmonar/cirurgia , Transplante de Pulmão , Adolescente , Adulto , Causas de Morte , Criança , Pré-Escolar , Oxigenação por Membrana Extracorpórea/mortalidade , Feminino , Seguimentos , Mortalidade Hospitalar , Humanos , Transplante de Pulmão/métodos , Transplante de Pulmão/mortalidade , Masculino , Complicações Pós-Operatórias , Reoperação , Sobreviventes
13.
Ann Thorac Surg ; 66(1): 199-203; discussion 203-4, 1998 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-9692464

RESUMO

BACKGROUND: Early primary graft failure due to reperfusion injury may occur in up to 10% of all patients undergoing lung transplantation. Late graft failure in the form of bronchiolitis obliterans progressively increases in frequency as posttransplantation follow-up increases. In both situations, the degree of pulmonary dysfunction may worsen and result in the death of the recipient. The only treatment in many instances is retransplantation. The results in adults are reasonably well established. METHODS: We reviewed our experience in children. Of the 136 transplant procedures performed to date in children, 14 have been retransplantations. Six patients required retransplantation for early primary graft failure and 8 underwent retransplantation for bronchiolitis obliterans. RESULTS: There were three early and three late deaths. The actuarial survival at 2 years is 58%. The retransplant procedures were more complex than the primary transplant operations as evidenced by the longer time on cardiopulmonary bypass (199 +/- 71 versus 150 +/- 41 minutes; p < 0.01) and the greater volume of blood transfused (1,303 +/- 936 versus 570 +/- 300 mL; p < 0.01). Two of the long-term survivors who received transplants for bronchiolitis obliterans have subsequently had development of this same condition and 1 died secondary to this. In four instances living related donors were used for the retransplant procedure. The most striking difference in these procedures compared with those transplantations performed with cadaveric donors was the shorter donor lung ischemic times (99.5 and 123.3 minutes for the two lungs for living related donors and 251 and 293 minutes for the first and second lung for the cadaveric donors; p < 0.01). CONCLUSIONS: We believe that lung retransplantation in children is a reasonable therapy to offer in the circumstance of severe graft dysfunction. In the older child, the option of living donor transplantation offers advantages that might offset of the overall higher risk of this procedure.


Assuntos
Transplante de Pulmão , Análise Atuarial , Adolescente , Adulto , Transfusão de Sangue , Bronquiolite Obliterante/etiologia , Bronquiolite Obliterante/fisiopatologia , Bronquiolite Obliterante/cirurgia , Cadáver , Ponte Cardiopulmonar , Causas de Morte , Criança , Pré-Escolar , Feminino , Seguimentos , Sobrevivência de Enxerto , Humanos , Lactente , Doadores Vivos , Pulmão/fisiopatologia , Transplante de Pulmão/efeitos adversos , Transplante de Pulmão/métodos , Transplante de Pulmão/fisiologia , Masculino , Reoperação , Fatores de Risco , Taxa de Sobrevida , Fatores de Tempo , Resultado do Tratamento
14.
Am J Transplant ; 6(5 Pt 2): 1132-52, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-16613592

RESUMO

This article reviews trends in pediatric solid organ transplantation over the last decade, as reflected in OPTN/SRTR data. In 2004, children younger than 18 years made up nearly 3% of the 86,378 candidates for organ transplantation and nearly 7% of the 27,031 organ transplant recipients. Children accounted for nearly 14% of the 7152 deceased organ donors. The transplant community recognizes important differences between pediatric and adult organ transplant recipients, including different etiologies of organ failure, surgical procedures that are more complex or technically challenging, effects of development on the pharmacokinetic properties of common immunosuppressants, unique immunological aspects of transplant in the developing immune system and increased susceptibility to posttransplant complications, particularly infectious diseases. For these reasons, and because of the impact of end-stage organ failure on growth and development, the transplant community has generally provided pediatric candidates with special consideration in the allocation of deceased donor organs. Outcomes following kidney, liver and heart transplantation in children often rank among the best. This article emphasizes that the prospects for solid organ transplantation in children, especially those aged 1-10 years are excellent. It also identifies themes warranting further consideration, including organ availability, adolescent survival and challenges facing pediatric transplant clinical research.


Assuntos
Transplante de Órgãos/história , Transplante de Órgãos/tendências , Adolescente , Criança , Pré-Escolar , Evolução Molecular , Rejeição de Enxerto , Sobrevivência de Enxerto , História do Século XX , História do Século XXI , Humanos , Lactente , Recém-Nascido , Transplante de Órgãos/estatística & dados numéricos , Doadores de Tecidos , Listas de Espera
15.
Am J Transplant ; 6(5 Pt 2): 1212-27, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-16613597

RESUMO

This article reviews the development of the new U.S. lung allocation system that took effect in spring 2005. In 1998, the Health Resources and Services Administration of the U.S. Department of Health and Human Services published the Organ Procurement and Transplantation Network (OPTN) Final Rule. Under the rule, which became effective in 2000, the OPTN had to demonstrate that existing allocation policies met certain conditions or change the policies to meet a range of criteria, including broader geographic sharing of organs, reducing the use of waiting time as an allocation criterion and creating equitable organ allocation systems using objective medical criteria and medical urgency to allocate donor organs for transplant. This mandate resulted in reviews of all organ allocation policies, and led to the creation of the Lung Allocation Subcommittee of the OPTN Thoracic Organ Transplantation Committee. This paper reviews the deliberations of the Subcommittee in identifying priorities for a new lung allocation system, the analyses undertaken by the OPTN and the Scientific Registry for Transplant Recipients and the evolution of a new lung allocation system that ranks candidates for lungs based on a Lung Allocation Score, incorporating waiting list and posttransplant survival probabilities.


Assuntos
Alocação de Recursos para a Atenção à Saúde/métodos , Transplante de Pulmão/métodos , Obtenção de Tecidos e Órgãos/métodos , Adolescente , Adulto , Idoso , Criança , Doação Dirigida de Tecido , Sobrevivência de Enxerto , Humanos , Pessoa de Meia-Idade , Alocação de Recursos , Estados Unidos , Listas de Espera
16.
Cell Motil Cytoskeleton ; 12(2): 113-22, 1989.
Artigo em Inglês | MEDLINE | ID: mdl-2713899

RESUMO

To investigate the association of calmodulin (CaM) with microtubules (MTs) in the mitotic apparatus (MA), the distributions of CaM and tubulin were examined in cells in which the normal spindle organization had been altered. A fluorescent CaM conjugate with tetramethylrhodamine isothiocyanate (CaM-TRITC) and a dichlorotriazinyl aminofluorescein conjugate with tubulin (tubulin-DTAF) were injected into cells that had been treated with the MT inhibitor nocodazole. With moderate nocodazole concentration (0.3 micrograms/ml, 37 degrees C, 4 h) in live cells, CaM-TRITC and tubulin-DTAF concentrated identically on or near the centrosomes and kinetochores. In serial sections of these cells, small MT segments were observed by transmission electron microscopy (TEM) in the regions where fluorescent protein had concentrated. When a higher drug concentration was used (3.0 micrograms/ml, 37 degrees C, 4 h), no regions of CaM-TRITC or tubulin-DTAF localization were observed, and no MTs were observed when serial sections were examined by TEM. However, following release from the high-concentration nocodazole block, CaM-TRITC colocalized with newly formed MTs at the kinetochores and centrosomes. Later in the recovery period, when chromosome-to-pole fibers had formed, CaM association with kinetochores diminished, ultimately attaining its normal pole-proximal association with kinetochore MTs in cells that progressed through mitosis. We interpret these observations as supporting the hypothesis that in the MA, CaM attains a physical association with kinetochore MTs and suggest that CaM-associated MTs may be inherently more stable.


Assuntos
Benzimidazóis/farmacologia , Calmodulina/metabolismo , Microtúbulos/metabolismo , Animais , Células Cultivadas , Centríolos/efeitos dos fármacos , Centríolos/metabolismo , Citoesqueleto/efeitos dos fármacos , Citoesqueleto/metabolismo , Fluoresceínas , Microscopia de Fluorescência , Microtúbulos/efeitos dos fármacos , Nocodazol , Organelas/efeitos dos fármacos , Organelas/metabolismo , Rodaminas , Fatores de Tempo , Tubulina (Proteína)
17.
Cell Motil Cytoskeleton ; 9(3): 231-42, 1988.
Artigo em Inglês | MEDLINE | ID: mdl-2896549

RESUMO

We have compared the exchange kinetics of fluorescein-labeled calmodulin and tubulin in the spindles of living mitotic cells at metaphase. Cultured mammalian cells in early stages of mitosis were microinjected with labeled calmodulin or tubulin and returned to an incubator to allow equilibration of the fluorescent protein with the endogenous protein pools. Calmodulin becomes concentrated in the mitotic spindle, and treatments with inhibitors of tubulin assembly show that this concentration is dependent on the presence of microtubules. The steady-state exchange rates of both tubulin and calmodulin were measured by an analysis of fluorescence redistribution after photobleaching (FRAP), using cells pre-equilibrated to either 26 +/- 2 degrees C or 36 +/- 2 degrees C. A pulse of laser light focused to a 5-microns diameter column was used to destroy the fluorescence at one pole of a metaphase mitotic spindle. Ratios of fluorescence intensity from the two half-spindles and from the two polar regions were calculated for each image in a post-bleach time series to determine the rates and extents of FRAP. For tubulin, we confirm earlier observations concerning the temperature dependence of the extent of FRAP, but our data do not show a significant temperature dependence for the rate of FRAP. We hypothesize that the reduced extent of tubulin FRAP at the lower temperatures is a result of microtubules that are stable to depolymerization at 26 degrees C and are thus less likely to exchange subunits. Calmodulin's FRAP, however, does not exhibit any of the temperature dependence observed with fluorescent tubulin. At 26 +/- 2 degrees C calmodulin exchanges rapidly with the relatively stable population of microtubules, suggesting that calmodulin is bound, either directly or indirectly, to microtubule walls.


Assuntos
Calmodulina/metabolismo , Metáfase , Fuso Acromático/metabolismo , Tubulina (Proteína)/metabolismo , Alcaloides/farmacologia , Animais , Benzimidazóis/farmacologia , Calmodulina/farmacologia , Calmodulina/fisiologia , Linhagem Celular , Fluoresceínas , Fluorescência , Técnicas In Vitro , Mitose , Nocodazol , Paclitaxel
18.
Am J Respir Crit Care Med ; 161(4 Pt 1): 1252-5, 2000 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-10764320

RESUMO

A major cause of morbidity and mortality following lung transplantation is posttransplant lymphoproliferative disease (PTLD). In a retrospective cohort analysis of pediatric patients, we evaluated the risk factors associated with PTLD in 128 first-time lung transplant recipients from 1990 to 1997. The greatest risk factor for PTLD was a diagnosis of cystic fibrosis (CF). Of the 16 patients in our analysis who had PTLD, 13 had a diagnosis of CF (odds ratio [OR]: 5.8; confidence interval 95% [CI]: 1.6 to 21.4). Because of the high frequency of PTLD in patients with CF (13 of 61; 23%), we performed a retrospective cohort analysis in which patients with CF and PTLD were designated as cases and patients with CF and without PTLD served as controls. In patients with CF, the only risk factor associated with PTLD was two or more episodes of acute rejection within 3 mo after transplantation (OR: 11.0; 95% CI: 2.7 to 55.7). Age, recipient Epstein-Barr virus or cytomegalovirus status, induction with antilymphocyte globulin or antithymocyte globulin (ATG), or use of ATG or OKT3 for acute rejection episodes were not risk factors for PTLD. The high frequency of PTLD in the subgroup of patients with two or more episodes of graft rejection within 2 mo after lung transplantation was unexpected, and warrants further investigation in prospective clinical studies and basic laboratories.


Assuntos
Fibrose Cística/cirurgia , Transplante de Pulmão , Transtornos Linfoproliferativos/epidemiologia , Complicações Pós-Operatórias/epidemiologia , Adolescente , Criança , Estudos de Coortes , Feminino , Rejeição de Enxerto/epidemiologia , Humanos , Terapia de Imunossupressão , Incidência , Masculino , Estudos Retrospectivos , Fatores de Risco
19.
Am J Respir Crit Care Med ; 155(3): 1027-35, 1997 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-9116982

RESUMO

Although accepted therapy in adults, lung transplantation in children is less well established. Reports from the few existing pediatric centers have involved relatively small patient number. Seventy-nine patients underwent 88 lung transplant procedures at St. Louis Children's Hospital between June 1990 and August 1995. Twenty-one transplants (24%) were done in 19 infants and children under the age of 3 yr. Twelve-, 24-, and 48-mo actuarial survival for the primary transplants was 69%, 67%, and 60%, respectively. Survival improved over the course of the program: 12-mo survival for patients transplanted during the first 18 mo was 42% compared with 78% for those transplanted after December 1991. Survival of children transplanted at younger than 3 yr of age was comparable to older children and adults. However, younger children had a lower incidence of acute rejection; none developed bronchiolitis obliterans. Both graft growth and linear growth occurred. Risk factors for early mortality included presence of aortopulmonary collateral vessels and prior thoracic surgery. Risk factors for survival duration included requiring assisted ventilation at the time of transplant, continuous supplemental oxygen requirement, and presence of aortopulmonary collateral vessels. The major late complication was bronchiolitis obliterans, which occurred in 27% of patients and played a role in 64% of late deaths. Investigation of the lower incidence of acute rejection and bronchiolitis obliterans in younger versus older children may reveal important information about the etiology of this disease. The ultimate long-term success of lung transplantation will depend on identification and treatment of the mechanisms responsible. A multicenter data registry would facilitate further clinical studies of pediatric lung transplantation.


Assuntos
Pneumopatias/cirurgia , Transplante de Pulmão/estatística & dados numéricos , Bronquiolite Obliterante/etiologia , Causas de Morte , Pré-Escolar , Hospitais Pediátricos , Humanos , Lactente , Transplante de Pulmão/mortalidade , Transtornos Linfoproliferativos/etiologia , Missouri , Complicações Pós-Operatórias , Estudos Retrospectivos , Fatores de Risco , Taxa de Sobrevida , Resultado do Tratamento
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