Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 11 de 11
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Front Genet ; 15: 1322414, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38343697

RESUMO

Allogeneic transplantation is a multi-step process involving many clinicians and laboratory personnel working together to achieve a common goal-to maximize the recipients' chance of survival and to improve their quality of life. One of the key elements of the process is to ensure high quality, accuracy, and reliability of histocompatibility testing. This manuscript presents: the development and organizational principles of the national system of supervision and control of histocompatibility laboratories in Poland, problems faced by these laboratories, availabe proficiency testing schemes, as well as suggestions and prospects for the future raised by members of the Polish histocompatibility community.

2.
J Funct Biomater ; 14(7)2023 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-37504866

RESUMO

Recently, tissue engineering, including 3D bioprinting of the pancreas, has acquired clinical significance and has become an outstanding potential method of customized treatment for type 1 diabetes mellitus. The study aimed to evaluate the function of 3D-bioprinted pancreatic petals with pancreatic islets in the murine model. A total of 60 NOD-SCID (Nonobese diabetic/severe combined immunodeficiency) mice were used in the study and divided into three groups: control group; IsletTx (porcine islets transplanted under the renal capsule); and 3D bioprint (3D-bioprinted pancreatic petals with islets transplanted under the skin, on dorsal muscles). Glucose, C-peptide concentrations, and histological analyses were performed. In the obtained results, significantly lower mean fasting glucose levels (mg/dL) were observed both in a 3D-bioprint group and in a group with islets transplanted under the renal capsule when compared with untreated animals. Differences were observed in all control points: 7th, 14th, and 28th days post-transplantation (129, 119, 118 vs. 140, 139, 140; p < 0.001). Glucose levels were lower on the 14th and 28th days in a group with bioprinted petals compared to the group with islets transplanted under the renal capsule. Immunohistochemical staining indicated the presence of secreted insulin-living pancreatic islets and neovascularization within 3D-bioprinted pancreatic petals after transplantation. In conclusion, bioprinted bionic petals significantly lowered plasma glucose concentration in studied model species.

3.
Cell Tissue Bank ; 23(4): 833-844, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-35267119

RESUMO

Ionizing radiation sterilization of non-defatted bone grafts has been found to deteriorate their quality and biocompatibility due to induction of lipid peroxidation products toxic for osteoblast-like cells. Therefore, the purpose of our study was to evaluate the effect of two types of ionizing radiation-gamma rays (G) or accelerated electron beam (EB) applied with two doses at different temperature conditions on hydrocarbons production, resulting from decomposition of palmitic and oleic acids-most abundant fatty acids in medullary lipids. Bone marrow samples isolated from femoral shafts of 6 male donors (aged 46-67 years) were irradiated with G or EB with doses of 25 or 35 kGy at different temperature conditions (ambient or deep freezing temperature). Fresh-frozen, non-irradiated samples served as control. Marrow lipids were extracted with n-hexane (Soxhlet's method), hydrocarbons fraction isolated on Florisil column chromatography, separated by gas chromatography and detected by mass spectrometry. Irradiation of bone marrow with sterilization doses of ionizing radiation (G and EB) was found to induce lipid radiolysis as measured by resulting hydrocarbons production. The effect was dose-dependent, whereas no marked influence of radiation type was observed. In contrast, irradiation temperature had a profound effect on lipids decomposition which was partially prevented while irradiation was performed in deep frozen state. Defatting of bone grafts prior to ionizing radiation sterilization seems essential for their biocompatibility, whereas irradiation in a deep-frozen state might compromise the effectiveness of sterilization and needs further studies.


Assuntos
Elétrons , Esterilização , Masculino , Humanos , Raios gama , Temperatura , Esterilização/métodos , Hidrocarbonetos , Lipídeos
4.
Biomedicines ; 9(12)2021 Nov 29.
Artigo em Inglês | MEDLINE | ID: mdl-34944607

RESUMO

Type 1 diabetes (T1D) is characterized by the destruction of over 90% of the ß-cells. C-peptide is a parameter for evaluating T1D. Streptozotocin (STZ) is a standard method of inducing diabetes in animals. Eight protocols describe the administration of STZ in mice; C-peptide levels are not taken into account. The aim of the study is to determine whether the STZ protocol for the induction of beta-cell mass destruction allows for the development of a stable in vivo mouse model for research into new transplant procedures in the treatment of type 1 diabetes. Materials and methods: Forty BALB/c mice were used. The animals were divided into nine groups according to the STZ dose and a control group. The STZ doses were between 140 and 400 mg/kg of body weight. C-peptide was taken before and 2, 7, 9, 12, 14, and 21 days after STZ. Immunohistochemistry was performed. The area of the islet and insulin-/glucagon-expressing tissues was calculated. Results: Mice who received 140, 160, 2 × 100, 200, and 250 mg of STZ did not show changes in mean fasting C-peptide in comparison to the control group and to day 0. All animals with doses of 300 and 400 mg of STZ died during the experiment. The area of the islets did not show any differences between the control and STZ-treated mice in groups below 300 mg. The reduction of insulin-positive areas in STZ mice did not exceed 50%. Conclusions: Streptozotocin is not an appropriate method of inducing a diabetes model for further research on transplantation treatments of type 1 diabetes, having caused the destruction of more than 90% of the ß-cell mass in BALB/c mice.

5.
Cell Tissue Bank ; 15(3): 413-28, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24197906

RESUMO

Ionizing radiation has been found to induce stable defects in the crystalline lattice of bone mineral hydroxyapatite, defined as CO(2) (-) radical ions possessing spins. The purpose of our study was to evaluate CO(2) (-) radical ions induced in non-defatted or defatted human compact bone by gamma radiation (G) and accelerated electron beam (EB), applied with two doses at different temperatures. Moreover, the potential effect of free radical ion formation on mechanical parameters of compact bone, tested under compression in the previous studies, was evaluated. Bone rings from femoral shafts of six male donors (age 51 ± 3 years) were collected and assigned to sixteen experimental groups according to different processing methods (non-defatted or defatted), G and EB irradiation dose (25 or 35 kGy), and irradiation temperature [ambient temperature (AT) or dry ice (DI)]. Untreated group served as control. Following grinding under LN2 and lyophilization, CO(2) (-) radical ions in bone powder were measured by electron paramagnetic resonance spectrometry. We have found that irradiation of bone with G and EB induces formation of enormous amounts of CO(2) (-) radical ions, absent from native tissue. Free radical ion formation was dose-dependent when irradiation was performed at AT, and significantly lower in EB as compared to G-irradiated groups. In contrast, no marked effect of dose was observed when deep-frozen (DI) bone samples were irradiated with G or EB, and free radical ion numbers seemed to be slightly higher in EB-irradiated groups. Irradiation at AT induced much higher quantities of CO(2) (-) radical ions then on DI. That effect was more pronounced in G-irradiated bone specimens, probably due to longer exposure time. Similarly, bone defatting protective effect on free radical ion formation was found only in groups irradiated for several hours with gamma radiation at ambient temperature. Ambient irradiation temperature together with exposure time seem to be key parameters promoting CO(2) (-) radical ion formation in bone mineral and may mask the opposite effect of defatting and the possible effect of irradiation type. Significant weak negative correlations between CO(2) (-) radical ion number and some mechanical properties of compact bone rings (Young's modulus and ultimate stress) were found.


Assuntos
Elétrons , Fêmur/efeitos da radiação , Raios gama , Fenômenos Biomecânicos/fisiologia , Densidade Óssea/efeitos da radiação , Espectroscopia de Ressonância de Spin Eletrônica/métodos , Fêmur/metabolismo , Humanos , Masculino , Pessoa de Meia-Idade , Esterilização/métodos , Temperatura
6.
Cell Tissue Bank ; 14(1): 141-5, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22318653

RESUMO

Personnel directly involved in the donation, procurement, testing, processing, preservation, storage and distribution of human tissues and cells should be appropriately qualified and provided with timely and relevant training according to EU directives. In the time of new tissue and cells regulations implementation such a training system existed in Poland only at a local level. The first training programme outlines for various groups of health professionals engaged in tissue banking practice was created in co-operation with the Institute for LifeLong Learning at University of Barcelona in 2006. This initial training courses were financially supported by EU Transition Facility Programme 2004. Then, starting from 2006, based on previous experience, system of advanced training courses was created. This training programme was financially supported by the National Programme for the Development of Transplantation Medicine 2006-2009-POLGRAFT financed by Polish Ministry of Health. During 2006 and 2007 first set of tissue banking initial training courses were provided according to TF 2004 project. Over 200 pathologists, forensic medicine specialists and other medical doctors responsible for donor screening and classification, medical directors of tissue establishments, technical staff; tissue graft users: orthopaedic surgeons, neurosurgeons, cardiosurgeons and ophthalmologists were trained. Between 2006 and 2009 there were organized 8 advanced tissue banking training courses according to POLGRAFT programme. There were organized both theoretical and practical courses on various aspects of tissue for over 350 persons. We present our experience in organisation of international and national tissue banking training courses.


Assuntos
Educação , Bancos de Tecidos , Humanos , Médicos , Polônia
7.
Cell Tissue Bank ; 13(3): 375-86, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22585354

RESUMO

Accelerated electron beam (EB) irradiation has been a sufficient method used for sterilisation of human tissue grafts for many years in a number of tissue banks. Accelerated EB, in contrast to more often used gamma photons, is a form of ionizing radiation that is characterized by lower penetration, however it is more effective in producing ionisation and to reach the same level of sterility, the exposition time of irradiated product is shorter. There are several factors, including dose and temperature of irradiation, processing conditions, as well as source of irradiation that may influence mechanical properties of a bone graft. The purpose of this study was to evaluate the effect e-beam irradiation with doses of 25 or 35 kGy, performed on dry ice or at ambient temperature, on mechanical properties of non-defatted or defatted compact bone grafts. Left and right femurs from six male cadaveric donors, aged from 46 to 54 years, were transversely cut into slices of 10 mm height, parallel to the longitudinal axis of the bone. Compact bone rings were assigned to the eight experimental groups according to the different processing method (defatted or non-defatted), as well as e-beam irradiation dose (25 or 35 kGy) and temperature conditions of irradiation (ambient temperature or dry ice). Axial compression testing was performed with a material testing machine. Results obtained for elastic and plastic regions of stress-strain curves examined by univariate analysis are described. Based on multivariate analysis, including all groups, it was found that temperature of e-beam irradiation and defatting had no consistent significant effect on evaluated mechanical parameters of compact bone rings. In contrast, irradiation with both doses significantly decreased the ultimate strain and its derivative toughness, while not affecting the ultimate stress (bone strength). As no deterioration of mechanical properties was observed in the elastic region, the reduction of the energy absorption capacity of irradiated bone rings apparently resulted from changes generated by irradiation within the plastic strain region.


Assuntos
Transplante Ósseo , Osso e Ossos/efeitos da radiação , Elétrons , Radiação Ionizante , Esterilização/métodos , Fenômenos Biomecânicos , Cadáver , Humanos , Masculino , Pessoa de Meia-Idade , Aceleradores de Partículas , Estresse Mecânico
8.
Cell Tissue Bank ; 13(3): 363-74, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22538985

RESUMO

The secondary sterilisation by irradiation reduces the risk of infectious disease transmission with tissue allografts. Achieving sterility of bone tissue grafts compromises its biomechanical properties. There are several factors, including dose and temperature of irradiation, as well as processing conditions, that may influence mechanical properties of a bone graft. The purpose of this study was to evaluate the effect of gamma irradiation with doses of 25 or 35 kGy, performed on dry ice or at ambient temperature, on mechanical properties of non-defatted or defatted compact bone grafts. Left and right femurs from six male cadaveric donors aged from 46 to 54 years, were transversely cut into slices of 10 mm height, parallel to the longitudinal axis of the bone. Compact bone rings were assigned to the eight experimental groups according to the different processing method (defatted or non-defatted), as well as gamma irradiation dose (25 or 35 kGy) and temperature conditions of irradiation (ambient temperature or dry ice). Axial compression testing was performed with a material testing machine. Results obtained for elastic and plastic regions of stress-strain curves examined by univariate analysis are described. Based on multivariate analysis it was found that defatting of bone rings had no significant effect on any mechanical parameter studied, whereas irradiation with both doses decreased significantly the ultimate strain and its derivative toughness. The elastic limit and resilience were significantly increased by irradiation with the dose 25 kGy, but not 35 kGy, when the time of irradiation was longer. Additionally, irradiation at ambient temperature decreased maximum load, elastic limit, resilience, and ultimate stress. As strain in the elastic region was not affected, decreased elastic limit resulted in lower resilience. The opposite phenomenon was observed in the plastic region, where in spite of the lower ultimate stress, the toughness was increased due to the increase in the ultimate strain. The results of our study suggest that there may be an association between mechanical properties of bone tissue grafts and the damage process of collagen structure during gamma irradiation. This collagen damage in cortical bone allografts containing water does not depends on the temperature of irradiation or defatting during processing if dose of gamma irradiation does not exceed 35 kGy.


Assuntos
Transplante Ósseo , Osso e Ossos/efeitos da radiação , Raios gama , Esterilização/métodos , Fenômenos Biomecânicos , Cadáver , Humanos , Masculino , Pessoa de Meia-Idade , Estresse Mecânico
9.
Cell Tissue Bank ; 11(2): 173-81, 2010 May.
Artigo em Inglês | MEDLINE | ID: mdl-20390363

RESUMO

The idea of transplantation seems to be commonly identified by lay and professional people only with transplantation of vascularized organs like kidney or heart. The question arises whether there is any awareness of tissue transplantation among the public. A survey was therefore undertaken to assess awareness of and approaches to tissue donation and transplantation among selected social groups. A questionnaire on donation and transplantation issues was administered to respondents from the following groups: secondary school students, non-medical university students, medical university students, physicians. On the whole, 441 non-randomly sampled respondents were surveyed. The awareness of tissue transplantation is narrower than the awareness of organ transplantation. The support for tissue transplantation is weaker than for organ transplantation. This study shows that there is an acute need for education in the legal aspects of transplantation and that ways of motivating healthcare professionals to promote transplantation should be developed.


Assuntos
Conhecimentos, Atitudes e Prática em Saúde , Transplante de Tecidos , Obtenção de Tecidos e Órgãos , Atitude do Pessoal de Saúde , Coleta de Dados , Humanos , Médicos , Polônia , Inquéritos e Questionários
10.
Biomed Pharmacother ; 60(4): 152-5, 2006 May.
Artigo em Inglês | MEDLINE | ID: mdl-16632298

RESUMO

Systemic sclerosis (SSc) is an autoimmune disease characterized by fibrosis of the skin and internal organs. It has been demonstrated that serum prolactin levels are increased in patients with various connective tissue diseases. The aim of this study was to investigate the possible source of excessive prolactin synthesis in SSc and its effects on immune cells. The study group consisted of 52 patients with diffuse SSc (44 women and eight men) and 52 age and sex matched healthy controls. The methods used were: ELISA and indirect immunofluorescence. Our results show significantly elevated level of prolactin in male and female patients with SSc and increased prolactin production by SSc lymphocytes as compared to healthy donors X lymphocytes (25.4+/-11.0 vs. 13.4+/-5.0 absorbance units). Patients X and healthy controls X lymphocytes, showed equal presence of prolactin receptors. Soluble interleukin 2 receptor (CD25) concentration, was significantly higher in supernatants of prolactin stimulated lymphocytes, as compared to non-stimulated lymphocytes. We conclude that lymphocytes might contribute to elevated prolactin levels in patients with SSc and that these cells themselves may be sensitive to prolactin stimulation. Therefore, a pharmacologic attempt to lower prolactin levels in patients with SSc could proof beneficial.


Assuntos
Linfócitos/metabolismo , Prolactina/biossíntese , Escleroderma Sistêmico/metabolismo , Adulto , Feminino , Humanos , Hiperprolactinemia/diagnóstico , Hiperprolactinemia/metabolismo , Masculino , Pessoa de Meia-Idade
11.
Cell Tissue Bank ; 6(3): 201-19, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-16151960

RESUMO

The Central Tissue Bank in Warsaw was established in 1963 and since then ionising radiation has been routinely applied to sterilise tissue grafts. Connective tissue grafts such as bone, cartilage, tendons, sclera, pericardium, skin, acellular dermis and amnion irradiated with a dose of 35 kGy in a (60)Co source and/or with an electron beam 10 MeV accelerator are prepared in our Tissue Bank and two other multi-tissue banks operating in Poland. Over 250,000 radiation-sterilised tissue grafts have been prepared and used in hospitals throughout Poland and no infectious disease transmission or other adverse post-transplantation reactions have been reported up to today. It should be kept in mind however, that high doses of ionising radiation can evoke numerous chemical and physical changes that may affect the biological quality of tissue allografts. Therefore, interdisciplinary research has been undertaken at the Central Tissue Bank in Warsaw to establish the origin and stability of free radicals and other paramagnetic entities induced by irradiation in bone. The effects of various preservation procedures (e.g. lyophilisation, deep-freezing) and irradiation conditions (doses, temperature of irradiation) on the osteoinductive potential and mechanical properties of bone and on the degradation of collagen, a major constituent of all connective tissue grafts, have been also studied. The results of these studies indicate that radiation-induced changes can be diminished by modification of tissue preservation methods and that, to some extent, it is possible to reduce undesired radiation-induced damage to the tissue grafts.


Assuntos
Radiação/classificação , Segurança/normas , Esterilização/métodos , Bancos de Tecidos , Colágeno/metabolismo , Humanos , Preservação de Tecido/métodos , Transplante Homólogo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...