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Cell seeding of three-dimensional polymer scaffolds is the first step of the cultivation of engineered tissues in bioreactors. Seeding requirements of large scaffolds to make implants for potential clinical use include: (a) high yield, to maximize the utilization of donor cells, (b) high kinetic rate, to minimize the time in suspension for anchorage-dependent and shear-sensitive cells, and (c) high and spatially uniform distribution of attached cells, for rapid and uniform tissue regeneration. Highly porous, fibrous polyglycolic acid scaffolds, 5-10 mm in diameter and 2-5 mm thick, were seeded with bovine articular chondrocytes in well-mixed spinner flasks. Essentially, all cells attached throughout the scaffold volume within 1 day. Mixing promoted the formation of 20-32-micron diameter cell aggregates that enhanced the kinetics of cell attachment without compromising the uniformity of cell distribution. The kinetics and possible mechanisms of cell seeding were related to the formation of cell aggregates by a simple mathematical model that can be used to optimize seeding conditions for cartilage tissue engineering.  相似文献   

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In haemophilic arthropathy there is a progressive limitation of the range of motion (ROM) which may lead to disabilities in the activities of daily living (ADL). In the literature the pathology of haemophilic arthropathy is described extensively, but only one paper describing functional limitations caused by limited range of motion (LOM) in haemophilia was found. The aim of the pilot study was to estimate on theoretical grounds, how many patients with haemophilia might suffer from functional disabilities. MATERIAL: ROM of elbows, knees and ankles of 155 Haemophilia A and B patients. METHODS: Flexion and extension were measured with an ordinary goniometer. The ROM of joints of patients with haemophilia was compared with normal values. RESULTS: 39 of 155 patients had a normal ROM in both elbows; 22 in one elbow; 34 patients had disabilities in ADL with both arms; 14 with one arm; 18 were able to compensate; 89 had no problems; 79 of 155 patients had a near normal ROM of both knees; 38 patients could not ride an ordinary bicycle. CONCLUSION: Only limited data are available concerning the normal ROM needed for individual ADL. Until additional data are available, it is not possible to predict which patients will be disabled in their activities of daily living and individual counselling should be done during the yearly outpatient comprehensive care clinics. Conservative and surgical measures should be taken to ensure elbow flexion of at least 120 degrees and knee flexion of 100 degrees for Western societies. In Asian countries patients with haemophilia need maximum knee flexion and ankle dorsi flexion.  相似文献   

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This consensus statement reflects the current status of temporomandibular joint surgery in the international community of oral and maxillofacial surgeons in the early 1990s. It is not the end, and it is not the beginning; it is a step forward in the treatment of patients with temporomandibular disorders. It is hoped that this statement will encourage member organizations, and individual members to pursue the issues raised by the proposed criteria. Also there should be continuing debate on the findings presented and on future developments, as well as efforts to teach others the skills the specialty has acquired.  相似文献   

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BACKGROUND: Allogeneic stem cell transplantation is being increasingly used to treat young patients with poor-prognosis low-grade lymphoproliferative disorders. We report our single-center experience. PATIENTS AND METHODS: Six adults (four with advanced chronic lymphocytic leukemia, one follicular center cell lymphoma and one mantle cell lymphoma) underwent allogeneic stem cell transplantation (SCT). Five received bone marrow while one received peripheral blood stem cells. Donors were HLA-identical siblings in five cases and an HLA-haploidentical sibling in one. The conditioning regimen included in five cases cyclophosphamide, TB1 and high-dose chlorambucil, without the latter in the patient with follicular lymphoma. RESULTS: Five patients successfully engrafted, while the patient who received the haploidentical marrow suffered primary graft failure. There were two cases of grade 2 acute GVHD and one limited chronic GVHD. Four patients are alive in complete remission (CR) with a follow-up of 17+ to 118+ months. Additionally, there is no evidence of residual disease by immunologic and molecular techniques in three cases, while one patient has residual disease assessed by molecular methods. CONCLUSIONS: These results suggest that allogeneic SCT can achieve prolonged remissions in advanced chronic lymphoproliferative disorders.  相似文献   

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In July 1994, we performed orthotopic heart transplantation for a patient with hypertrophic myocardiopathy, who had had open heart surgery enlarging the right ventricular outlet. The patient had an excellent postoperative result. He received triple-drug immunosuppressive therapy. Large dose of methyl-prednisolone was used successfully for his acute rejection reaction. At present, the patient is living well with good cardiac, hepatic and renal function. We described donor heart harvest, myocardial protection, operative procedure, immune monitoring, anti-rejection and anti-infectious therapy. We introduced the process of protecting donor heart on the way to hospital by retrograde perfusion with medium hypothermic oxygenated-blood combined with St. Thomas cardioplegia. Besides endomyocardial biopsy, other noninvasive examinations such as noninvasive cardiac output monitoring could be helpful to monitor acute rejection reaction.  相似文献   

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We report a patient with intraperitoneal metastases following treatment for seminoma. This is an unusual site of spread and was accompanied by transformation of tumour morphology.  相似文献   

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Combined heart-kidney transplantation: report on six cases   总被引:1,自引:0,他引:1  
Nisin is a membrane active antimicrobial peptide containing unusual dehydrated amino acid residues. The secondary structure of nisin in aqueous solution, membrane mimicking solvents and at various pH values was investigated using circular dichroism. In aqueous solution nisin is largely randomly coiled. In liposomes and at pH 6 and above, however, the presence of a maximum at 195 nm and a minimum at 190 nm was notable and indicative of beta-turn formation in these environments. This change in structure was speculated to result in an increasing unavailability of the site for initial reaction of peptide and membrane at higher pH.  相似文献   

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Partial lesions of the mammalian spinal cord result in an immediate motor impairment that recovers gradually over time; however, the cellular mechanisms responsible for the transient nature of this paralysis have not been defined. A unique opportunity to identify those injury-induced cellular responses that mediate the recovery of function has arisen from the discovery of a unique mutant strain of mice in which the onset of Wallerian degeneration is dramatically delayed. In this strain of mice (designated WldS for Wallerian degeneration, slow), many of the cellular responses to spinal cord injury are also delayed. We have used this experimental animal model to evaluate possible causal relationships between these delayed cellular responses and the onset of functional recovery. For this purpose, we have compared the time course of locomotor recovery in C57BL/6 (control) mice and in WldS (mutant) mice by hemisecting the spinal cord at T8 and evaluating locomotor function at daily postoperative intervals. The time course of locomotor recovery (as determined by the Tarlov open-field walking procedure) was substantially delayed in mice carrying the WldS mutation: C57BL/6 control mice began to stand and walk within 6 days (mean Tarlov score of 4), whereas mutant mice did not exhibit comparable locomotor function until 16 days postoperatively. Interpretation and conclusion: (a) The rapid return of locomotor function in the C57BL/6 mice suggests that the recovery resulted from processes of functional plasticity rather than from regeneration or collateral sprouting of nerve fibers. (b) The marked delay in the return of locomotor function in WldS mice indicates that the processes of neuroplasticity are induced by degenerative changes in the damaged neurons. (c) These strains of mice can be effectively used in future studies to elucidate the specific biochemical and physiological alterations responsible for inducing functional plasticity and restoring locomotor function after spinal cord injury.  相似文献   

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A 20-year-old female was admitted because of high fever, hepatosplenomegaly, severe hepatic dysfunction and coagulopathy. Peripheral blood showed pancytopenia and granular lymphocytes bearing the natural killer cell phenotype (CD2+CD3-CD16+CD56+CD57-TCR alpha beta-TCR gamma delta-) constituted 97% of leucocytes. Southern blot analysis of DNA obtained from peripheral blood mononuclear cells showed germ-line configuration of TCR beta, gamma and delta chain genes. EBV-DNA was detected in a single episomal form by using EBV-terminal repeat probe. Bone marrow findings were consistent with hemophagocytic syndrome and administration of VP-16 was effective transiently. After ten months she died from massive gastrointestinal bleeding. An in situ hybridization study identified EBV-RNA (EBER-1) in atypical lymphocytes infiltrating bone marrow, spleen and lymph nodes. Sections of liver showed steatosis and infiltration of T cells (CD3+ and EBER-1-negative) in the portal areas and few atypical lymphocytes in sinusoids. The patients developed an EBV-associated clonal proliferation of natural killer (NK) cells, but the clinical features were suggestive of chronic active EBV infection or virus-associated hemophagocytic syndrome (VAHS) rather than leukemia. Bone marrow transplantation for NK cell leukemia is an issue to be discussed.  相似文献   

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