Transplantation

About: Transplantation is a research topic. Over the lifetime, 276584 publications have been published within this topic receiving 7961661 citations.

Amniotic Membrane Transplantation With or Without Limbal Allografts for Corneal Surface Reconstruction in Patients With Limbal Stem Cell Deficiency

Abstract: Objective To examine whether amniotic membrane transplantation (AMT), in preparing the perilimbal stroma, enhances the success of allograft limbal transplantation (ALT). Methods Thirty-one eyes of 26 consecutive patients had cytologically proven limbal deficiency resulting from chemical burns (14 eyes); Stevens-Johnson syndrome, toxic epidermal necrolysis, or pseudopemphigoid (5 eyes); contact lens–induced keratopathy (3 eyes); aniridia (3 eyes); multiple surgical procedures (2 eyes); atopy (2 eyes); or an unknown cause (2 eyes). Based on the severity of limbal deficiency, group A (mild), comprising 10 eyes, received AMT alone; group B (moderate), comprising 7 eyes, received AMT and ALT; and group C (severe), comprising 14 eyes, received AMT, ALT, and penetrating keratoplasty. All patients except those in group A received continuous oral cyclosporine. Results Except for the 2 eyes with atopy, all amniotic membrane–covered surfaces showed rapid epithelialization (in 2 to 4 weeks) and reduced inflammation, vascularization, and scarring, and the surfaces became smooth and wettable. For the mean follow-up period of 15.4 months, 25 (83%) of 30 eyes showed visual improvement, consisting of 6 or more lines (13 eyes), 4 to 5 lines (6 eyes), or 1 to 3 lines (6 eyes). Visual improvement decreased with the severity of limbal deficiency from 8 (100%) of 8 eyes in group A to 5 (71%) of 7 eyes in group B and 11 (79%) of 14 eyes in group C. In group C, corneal graft rejection occurred in 9 (64%) of 14 eyes, and reversible early limbal allograft rejection was noted in 3 (14%) of 21 eyes of groups B and C. Conclusions For partial limbal deficiency with superficial involvement, AMT alone is sufficient and hence superior to ALT because there is no need to administer cyclosporine. For total limbal deficiency, additional ALT is needed, and AMT helps reconstruct the perilimbal stroma, with reduced inflammation and vascularization, which collectively may enhance the success of ALT.

A diffusible coupling signal from the transplanted suprachiasmatic nucleus controlling circadian locomotor rhythms

Abstract: The mammalian suprachiasmatic nuclei (SCN) transmit signals to the rest of the brain, organizing circadian rhythms throughout the body. Transplants of the SCN restore circadian activity rhythms to animals whose own SCN have been ablated. The nature of the coupling signal from the grafted SCN to the host brain is not known, although it has been presumed that functional recovery requires re-establishment of appropriate synaptic connections. We have isolated SCN tissue from hamsters within a semipermeable polymeric capsule before transplantation, thereby preventing neural outgrowth but allowing diffusion of humoral signals. Here we show that the transplanted SCN, like neural pacemakers of Drosophila and silkmoths, can sustain circadian activity rhythms by means of a diffusible signal.

Phenotypical and functional specialization of FOXP3 + regulatory T cells

Abstract: Forkhead box P3 (FOXP3)(+) regulatory T (T(Reg)) cells prevent autoimmune disease, maintain immune homeostasis and modulate immune responses during infection. To accomplish these tasks, T(Reg) cell activity is precisely controlled, and this requires T(Reg) cells to alter their migratory, functional and homeostatic properties in response to specific cues in the immune environment. We review progress in understanding the diversity of T(Reg) cells, T(Reg) cell function in different anatomical and inflammatory settings, and the influence of the immune environment on T(Reg) cell activity. We also consider how these factors affect immune-mediated disease in the contexts of infection, autoimmunity, cancer and transplantation.

A working formulation for the standardization of nomenclature and for clinical staging of chronic dysfunction in lung allografts. International Society for Heart and Lung Transplantation.

Abstract: A clinically applicable, standardized method for assessing functional results after lung transplantation is required to evaluate factors that may affect long-term outcome, to permit comparison of results from different centers, and to evaluate results of clinical trials An ad hoc working group was established under the auspices of the International Society for Heart and Lung Transplantation for the purpose of developing such a clinically applicable system Chronic allograft dysfunction is often associated with pathologic findings of obliterative bronchiolitis, the cause of which has not been defined Physiologically, such dysfunction is associated with obstructive airways disease The group concluded that the forced expiratory volume in 1 second was the most reliable and consistent indicator of graft dysfunction, excluding other identifiable causes The term bronchiolitis obliterans syndrome was adopted to describe such dysfunction, recognizing that there may or may not be pathologic evidence of bronchiolitis obliterans present Four stages of bronchiolitis obliterans syndrome were defined, each with two subcategories to indicate whether pathologic evidence of obliterative bronchiolitis had been identified This working formulation will require reappraisal in the future to reassess its practical application and to make such adjustments as may seem appropriate