PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Tissue Transplantation”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources
PubMedDate not supplied

[Phenotypic differences between CD34 positive cells in various transplantation tissues].

Transplantations to restore the hematopoietic system were originally performed with cells from the bone marrow (BM) (20) which was considered the only cell source comprising repopulating progenitor cells. The discovery that chemotherapy induced the mobilization of CD34+ cells into the peripheral blood (PB) (14) gave rise to the successful autologous transplantation of PBSC (1, 13). Also cord blood (CB) was found to contain considerable numbers of "stem cells", and to date at least 42 allogeneic transplantations have been performed with this cell source (22, J. Wagner, personal communication). Further investigations led to the successful autologous transplantation of positively selected CD34+ cells from BM and PB (18), and the latest results indicate that it is promising to transplant purified CD34+ cells obtained from cytokine-stimulated donors (4, 10, 15-16). Despite such achievements it remains unclear how many "stem cells" are required per kg of the recipient and how they are phenotypically characterized. In this communication we give examples of typical differences observed by flow cytometry and clonogenic assay between the CD34+ cells contained in the different cell sources. They may explain why it is not sufficient only to analyze the CD34+ cell populations which may represent progenitors of different lineages as well as of various states of differentiation. CB CD34+ cells are early myeloid progenitor cells with the highest incidence of CFU-mix among the three cell sources. They have a high proliferative potential in vitro. They hardly coexpress B cell antigens and they are partially negative for CD38.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed2006

[Different types of tissue transplantation in repairing tissue defects and function reconstruction].

OBJECTIVE: To explore the clinical effect of different types of free tissue transplantation on repairing tissue defects and reconstructing functions. METHODS: From November 2001 to September 2004, 14 types of free tissue transplantation and 78 free tissue flaps were applied to repairing tissue defects and reconstructing functions in extremities and maxillofacial region in 69 cases. Of the 69 cases, there were 53 males and 16 females (their ages ranged from 18 to 56, 31 on average). Five cases were repaired because of skin defects in foot, 22 cases were repaired because of skin defects in leg, 36 cases were repaired as the result of skin defects in hand or forearm and finger reconstruction, 3 cases were restored by virtue of ulna or radius defects, and 3 cases were repaired in maxillofacial region. There were 55 cases of open wound, in which 16 cases were infectious wound, 6 cases were osteomyelitis or pyogenic arthritis. There were 14 cases of non-infectious wound. The area of these tissue flaps ranged from 2.0 cm x 1.5 cm to 43.0 cm x 12.0 cm. The length of bone transplantation ranged from 10 cm to 15 cm. RESULTS: Arterial crisis occurred in 2 cases, venous crisis occurred in 2 cases. Seventy-six flaps survived completely and 2 flaps survived partially which were later healed. Fifty-two cases were healed at stage I, 13 cases were healed at stage I (healing time ranged from 20 to 30 days), purulent infection occurred to 4 cases(healing time ranged from 3 to 11 months). Bone healing time ranged from 6 to 8 weeks in finger reconstruction. Bone healing time ranged from 4 to 6 months in fibula transplantation. The function reconstruction and appearance were satisfying. The functions of all regions, where free tissues were supplied, were not disturbed. CONCLUSION: Tissue transplantation and composite tissue transplantation are effective in repairing tissue defects and reconstructing functions.

Adolescent↗
PubMed1998

The histo-blood group ABO system and tissue transplantation.

In general, one might expect that ABO incompatibility of donor and recipient would be important to some degree if viability of the transplanted allograft is important for graft incorporation and function. This is true for some recipients of organs. However, ABO incompatibility appears to play a minor role, if any, in the clinical success of viable cornea and viable skin allografts. Even though A and B antigens may be present on the transplanted tissue, other factors that can contribute include the strength of the immune response, the avidity of the antibody, and the dose of the antigen presented, which may vary from donor to donor. Although A and B antigens are present on endothelium, the use of ABO-incompatible heart valves is successful, as they carry out their mechanical function by using the strength of the connective tissue rather than the viability of the donor endothelium. The presence, immunogenicity, and significance of A and B antigens in human vessel transplants have not been well studied. With the more commonly transplanted tissue, such as bone and tendon, posttransplant success does not depend on cellular viability or ABO compatibility.

ABO Blood-Group System↗
PubMed2006

Hyperbaric oxygen and lymphoid system function: a review supporting possible intervention in tissue transplantation.

This review addresses the many ways that hyperbaric oxygen (HBO2) has been found to mitigate immune reactions, many of which are involved in rejection of allograft transplants, and thus offers a rationale for its possible use as an adjunct to help preserve and protect transplanted tissues. Rejection may involve both immunological reactions of the lymphoid system, or lymphoid-independent damage from trauma or other factors, including reperfusion injury. Lymphoid-induced damage involves cellular elements such as CD4 and macrophage cell types, as well as both proinflammatory and inhibitory cytokines. Cytokines such as TNFs and interleukins activate T-cells and macrophages, resulting in endothelial damage and its consequences. The immunosuppressive effects of HBO2 include suppression of autoimmune symptoms, decreased production of IL-1 and CD4 cells, and increased percentage and absolute number of CD8 cells. HBO2 normalizes cell-bound immunity and decreases the serum concentration of immune complexes. Studies have shown MHC class I expression to be altered when cultures were exposed to HBO2, so as to become undetectable by monoclonal antibodies or cytotoxic T lymphocytes. HBO2 has been used in support of replanted rabbit ear grafts, spinal cord tissue transplants, dislocated young permanent teeth in children, replanting of fingers, free fibula reconstruction of segmental mandibular resections, autogenous free bone grafts, transplantations of the cornea, and liver transplants. In addition to its specific effects on the immune system, HBO2 improves tissue oxygenation, reduces free radical damage during reperfusion, maintains marginally ischemic tissue, and accelerates wound healing. These properties make HBO2 a promising intervention to be tested in transplantation recipients.

Animals↗
PubMed1999

Effect of subcutaneous pancreatic tissue transplants on streptozotocin-induced diabetes in rats. I. Morphological studies on normal, diabetic and transplanted pancreatic tissues.

The present study examines the morphological changes occurring in subcutaneous pancreatic tissue grafts (SPTG) and its effect on the host pancreatic islet cells in streptozotocin (STZ)-induced diabetic rats using morphological techniques. SPTG survived after 15 weeks of transplantation. Its acinar cells degenerated but the ducts and endocrine cells survived. The surviving and newly formed pancreatic tubules and endocrine cells filled the spaces left by degenerated acinar cells. Compartmentalization of the surviving parenchymatic tissues was observed, with the pancreatic tubules lying in the periphery of the graft and the endocrine tissue in the inner portion of the graft. Lymphocytes invaded the inner portion of the graft, conglomerating around endocrine cells. It was interesting, however, that, lymphocytes where not observed in the periphery of the grafts where most of the surviving pancreatic tubules lie. In addition to this, necrotic tissues were observed in the inner part of the graft. Fifteen weeks after transplantation into the subcutaneous region, insulin, glucagon, somatostatin and pancreatic polypeptide-immunoreactive cells were observed in many parts of the graft. In the peripheral parts of the grafts, large numbers of pancreatic tubules differentiated into endocrine cells. In conclusion, the ductal and endocrine cells of pancreatic tissue fragments survived in the subcutaneous region of rat with normal pattern of distribution.

Animals↗
PubMedDate not supplied

Neurotransmitter receptors in fetal tissue transplants: expression and functional significance.

Numerous studies have examined receptor expression in neural transplants and their possible role in transplant-induced functional recovery from lesion-induced deficits. Herein we attempt to summarize the results of these studies, especially those from studies involving striatal transplants. Autoradiographic studies indicate that dopamine D1 and D2, muscarinic, cholinergic, 5-HT2, opiate mu, beta adrenergic and cholecystokinin (CCK) receptors are present in striatal transplants. Many of these receptors are present regardless of the transplant location and surrounding environment. This suggests that the expression of these receptors is determined by intrinsic properties of transplanted tissue, and is independent of transplant location and environment. Some transplant receptors, such as dopamine D1 and D2 and muscarinic receptors in striatal transplants, or 5-HT2 receptors in cortical transplants, display a patchy distribution which is dissimilar to that in the corresponding adult host tissue. This manuscript discusses this "abnormal" receptor distribution and possible explanations. Electrophysiological studies have indicated that some of the transplant receptors respond to physiological and pharmacological stimulation, suggesting that they are functional. However, the association of receptor expression with behavioral recovery is uncertain. The expression of neurotransmitter receptors in neural transplants may not be essential for the functional recovery associated with trophic mechanisms. However, neurotransmitter receptors may play an important role when functional recovery requires neuroanatomical integration between the host brain and the transplanted tissue.

Animals↗
PubMed1986

Irradiation of free vascularized tissue transplants in rats.

The aim of this experimental investigation was to show whether immediate irradiation of a free flap or an island flap is dangerous or not. The free epigastric flap of the rat was used as a model for this investigation. The patency of the epigastric vessels of the rat was not influenced by the irradiation and the histological findings showed no early reaction to the irradiation of the vessels of the transplanted tissue. The vessels of this experiment indicate that a free tissue transplantation is possible even if a combined radio-surgical treatment is planned.

Animals↗
PubMed1991

The cutting edge: neurotransmitters and brain tissue transplant.

Neural tissue transplant represents one of the most exciting and controversial areas of current basic neuroscience research. It offers enormous therapeutic promise for patients with degenerative and traumatic neurologic disorders. This article reviews the functions of several common neurotransmitters and examines the clinical applications of tissue transplant into the human nervous system.

Animals↗
PubMed1992

Autoradiographic determination of glucose content and estimation of the lumped constant in intracerebral neuronal tissue transplants.

The quasi-steady-state distribution volume of brain glucose was measured using 3-O-[14C]methylglucose quantitative autoradiography in a group of rats (n = 5) which 12-15 weeks previously had undergone unilateral ibotenic acid-induced lesion of the nucleus basalis magnocellularis, followed by implantation into ipsilateral neocortex of primordial basal forebrain cell suspensions. The effects of the lesion and the presence of transplanted tissue in neocortex were visualized by acetylcholinesterase histochemistry. The 3-O-[14C]methylglucose tracer was distributed homogeneously throughout the host brain areas analysed, with no side-to-side differences, despite a marked unilateral depletion of acetylcholinesterase activity ipsilateral to the lesion site. Whilst the transplants were indistinguishable from the homogeneity of surrounding host frontal cortex, there was a 70% increase in the apparent distribution volume of methylglucose localized around the ibotenate injection site and associated needle tract. Brain glucose content is an important experimental variable affecting the lumped constant of the 2-deoxyglucose technique. There was no evidence of any significant difference in the lumped constant between transplant and host tissue which might compromise the validity of the 2-deoxyglucose technique when used together with intracerebral implantation of fetal neuronal cell suspensions.

3-O-Methylglucose↗
PubMed2005

Decreasing latitude and increasing regulation in transplantable tissue programs.

ADVANCED TECHNOLOGY and improved surgical techniques have led to new therapeutic uses for allografts. DISEASE TRANSMISSION via allograft tissue transplants has prompted federal intervention in the tissue banking industry and resulted in federal regulations. NEW STANDARDS from the Joint Commission on Accreditation of Healthcare Organizations became effective July 1, 2005, and apply to all hospitals that store or implant allograft tissues. These standards include mandatory policies on all aspects of hospital transplantation programs, including tissue ordering, receipt, storage, issuance, and record keeping.

Federal Government↗
PubMed2000

Tissue-binding properties of a synthetic peptide DNA vector targeted to cell membrane integrins: a possible universal nonviral vector for organ and tissue transplantation.

BACKGROUND: Gene delivery through a nonviral, receptor-mediated system widely expressed in transplanted tissue would have important advantages in transplantation, where gene delivery is performed ex vivo. Integrins are widely expressed cell surface receptors and can be targeted for gene delivery. METHODS: A synthetic 31 amino acid DNA vector (polylysine-molossin) comprising a 15-amino acid moiety for targeting cellular integrins (derived from the snake venom, molossin) and a 16-amino acid polylysine moiety for DNA-binding, has been evaluated. The 31-amino acid vector, as well as its separate 15-amino acid integrin-binding and (lys)16 components, were individually synthesized, and a monoclonal antibody was raised to the molossin peptide for these studies. Binding to cell lines and tissue sections and capacity for gene delivery were examined. RESULTS: Flow cytometric studies with the ECV304 cell line demonstrated that the binding of polylysine-molossin and polylysine-molossin/DNA complexes involved both electrostatic and integrin-mediated interactions with the cells, with the electrostatic binding being sufficient for maximal binding. However, binding to cellular integrins was essential for successful gene transfer. Binding studies on frozen tissue sections of the rat and pig demonstrated that the molossin peptide bound to many cell types of interest in transplantation, but not to all. Among the negative tissues were vascular endothelium and pancreatic islets. Small species differences in tissue binding were noted between the rat and pig. CONCLUSIONS: This study defines the cooperative nature of the binding of this vector system to target cells and establishes the cell types most likely to be effectively targeted for DNA transfer.

Antineoplastic Agents↗
PubMed1999

Risk of prion disease transmission from ocular donor tissue transplantation.

PURPOSE: Recent new reports of possible iatrogenic transmission of Creutzfeldt-Jakob disease (CJD) in Europe have prompted renewed scrutiny of current Eye Bank Association of America criteria for evaluation of potential corneal donors in this country. A prior study evaluated the risk of CJD occurring in U.S. corneal donors by using data to 1994. This report updates these data, analyses the risk by using data to 1997, and predicts potential risk into the next decade. METHODS: EBAA data inclusive through 1997 were reviewed and correlated with incidence figures for CJD in the United States as provided by the Communicable Disease Center in Atlanta. RESULTS: The annual incidence of CJD has remained stable at 1 case per million population. Thus approximately 270 new cases of CJD would be expected to occur each year in the United States. From this, the calculated risk of a prion-infected corneal donor appearing in the donor pool is 0.045 cases per year. If the data are corrected for age (90% of CJD patients are older than 60 years) and for possible infected but asymptomatic CJD patients (prevalence, 70 cases per million), at worst, 2.12 cases per year would appear for potential corneal donation (0.005% of all donors). Whereas donors completely without any neurologic symptoms cannot be screened by using any currently available laboratory method, those with a characteristic quadrate clinical prodrome including cognitive changes, speech abnormalities, cerebellar findings, and myoclonus could all be potentially excluded by using tightened medical record and historical screening criteria. Although no cases of bovine spongiform encephalopathy (mad-cow disease) or new variant CJD have been reported in the United States, if such should occur, only 4.2 cases of CJD would be expected in potential donors each year (0.009% of all donors). Tightening of exclusionary queries would significantly reduce the risk of even this number of patients appearing for corneal donation. CONCLUSIONS: Historical queries of potential corneal donors should be tightened to assure exclusion of donors with early neurologic alterations. Any patient undergoing autopsy for evaluation of possible central nervous system (CNS) disease should be absolutely excluded. With this approach, the risk of inclusion of CJD-infected transplant tissues derived from ocular sources is very small, and all previously reported cases would have been prospectively excluded from surgical use. Clearly, the benefits of corneal transplantation in the overall population continue significantly to outweigh the risks of transmission of prion disease.

Animals↗
PubMed2002

National MOTTEP: educating to prevent the need for transplantation. Minority Organ Tissue Transplant Education Program.

The purpose of this study was to determine whether participation in culturally appropriate, community-developed, health education programs addressing organ/tissue donation and preventing the need for transplantation, is an effective strategy for contributing to sustained behavior change among members of minority population groups. Within 15 target cities, 800 (40%) minority participants consented to a 2-3 month telephone follow-up survey. The 5-item questionnaire using items extracted from the pre- and post-survey instrument, addressed: 1) knowledge and beliefs; 2) willingness to sign donor cards and have family discussions; and 3) prevention/health behaviors. The preliminary findings based on telephone interviews with 253 participants indicate the following: [table: see text] The conclusions indicate that the community-based, culturally appropriate health education strategies used contributed to and sustained behavior changes.

Attitude to Health↗
PubMed1993

[Malignant tumor developing in transplanted tissue in the oral cavity (case report)].

Primary and metastatic malignant tumors appears frequently in the head and neck region. The occurrence of malignancies in tissues--transplanted to this area--are extraordinary rare. Authors report about a case, where the tumor developed in a cylindroid jump flap, used to the closure of the cleft palate. They discuss theoretical aspects, as well as the course of the disease.

Adult↗
PubMed1986

A comparative study of transplant sites for endocrine tissue transplantation in the pig.

Thyroid and thymus tissue autografts were used to examine the suitability of different transplant sites in the pig for endocrine tissue transplantation. The omental pouch, gall bladder fossa and renal subcapsular space showed optimal implantation, preservation and vascularisation of graft tissue. Marked dissemination of graft tissue was observed at intramuscular sites and graft viability at subcutaneous sites in the ear was poor. The omental pouch represents a potentially suitable site for pancreatic islet tissue transplantation studies in the pig.

Animals↗