RESUMO
The Banff Working Group on Liver Allograft Pathology reviewed and discussed literature evidence regarding antibody-mediated liver allograft rejection at the 11th (Paris, France, June 5-10, 2011), 12th (Comandatuba, Brazil, August 19-23, 2013), and 13th (Vancouver, British Columbia, Canada, October 5-10, 2015) meetings of the Banff Conference on Allograft Pathology. Discussion continued online. The primary goal was to introduce guidelines and consensus criteria for the diagnosis of liver allograft antibody-mediated rejection and provide a comprehensive update of all Banff Schema recommendations. Included are new recommendations for complement component 4d tissue staining and interpretation, staging liver allograft fibrosis, and findings related to immunosuppression minimization. In an effort to create a single reference document, previous unchanged criteria are also included.
Assuntos
Rejeição de Enxerto/etiologia , Rejeição de Enxerto/patologia , Isoanticorpos/imunologia , Transplante de Fígado/efeitos adversos , Aloenxertos , Humanos , Relatório de PesquisaRESUMO
Adenovirus (AdV) infection can occur early after transplantation, especially with potent immunosuppression for induction or acute rejection treatment. We present the largest case series of adult renal recipients from a single institution with AdV infection, and the first apparent case of transferred AdV infection from 1 deceased donor to 2 kidney recipients. Three patients received kidneys from 2 deceased donors: 2 from a 23-year-old donor, and the third from a 4-year-old donor. The recipients with the same donor both displayed early rejection. One who eventually lost his graft to AdV nephritis required treatment with plasmapheresis, intravenous immunoglobulin, rituximab, and anti-thymocyte globulin for severe antibody-mediated rejection. The second required only steroids for acute cellular rejection and has good renal function at 7 years. The third recipient was discovered to have AdV and microabscesess on renal biopsy and required nephrectomy. In the 2 cases of graft loss, we observed sudden deterioration of graft function with rising creatinine and subsequent necrosis resulting in nephrectomy within 40 days after transplantation. AdV was detected by polymerase chain reaction in urine or serum and/or renal tissue. AdV activation after potent immunosuppression can lead to systemic infection and may trigger rejection and/or early graft loss.
Assuntos
Infecções por Adenovirus Humanos/transmissão , Transplante de Rim/efeitos adversos , Doadores de Tecidos , Adulto , Pré-Escolar , Rejeição de Enxerto , Sobrevivência de Enxerto , Humanos , Masculino , Pessoa de Meia-Idade , Adulto JovemRESUMO
BACKGROUND: Mixed lymphohematopoietic chimerism can provide an effective means of inducing longterm immunological tolerance and has been documented in a monkey allograft model. A conditioning regimen including nonmyeloablative or myeloablative irradiation and splenectomy has been used to induce chimerism in a pig-to-primate transplantation model. Since the presence of anti-Gal(alpha)1-3Gal (alphaGal) natural antibodies leads to the hyperacute rejection of pig organs transplanted into primates, extracorporeal immunoaffinity adsorption (EIA) of anti-alphaGal antibodies is also included in the regimen. The effect of the tolerance induction protocol on the anti-alphaGal antibody response has been assessed. METHODS: Anti-alphaGal antibody was measured after the EIA of plasma through an alphaGal immunoaffinity column in baseline studies involving two unmodified baboons, one splenectomized baboon, and one baboon that received a challenge with porcine bone marrow (BM), and in three groups of baboons (n=2 in each group) that received different conditioning regimens for tolerance induction. Group 1 received a nonmyeloablative conditioning regimen without porcine BM transplantation. Group 2 received nonmyeloablative conditioning with pig BM transplantation and pig cytokine therapy. Group 3 received myeloablative conditioning, an autologous BM transplant (with BM depleted of CD2+ or CD2+/CD20+ cells), and pig BM transplantation. RESULTS: In the baseline studies, a single EIA of anti-alphaGal antibodies in an unmodified animal initially depleted anti-alphaGal antibody, followed by a mild rebound. Nonmyeloablative conditioning (group 1) in the absence of pig cell exposure reduced the rate of anti-alphaGal antibody return. Pig BM cells markedly stimulated anti-alphaGal antibody production in an unmodified baboon (alphaGal IgM and IgG levels increased 40- and 220-fold, respectively). This response was significantly reduced (to an only 2- to 5.5-fold increase of IgM and IgG) in baboons undergoing nonmyeloablative conditioning (group 2). A myeloablative conditioning regimen (group 3) prevented the antibody response to pig BM, with the reduction in response being greater in the baboon that received autologous BM depleted of both CD2+ and CD20+ cells. No new antibody directed against pig non-aGal antigens was detected in any baboon during the 1 month follow-up period. CONCLUSIONS: (i) EIA of anti-alphaGal antibody in unmodified baboons results in a transient depletion followed by a mild rebound of antibody; (ii) exposure to pig BM cells results in a substantial increase in anti-alphaGal antibody production; (iii) a nonmyeloablative conditioning regimen reduces the rate of antibody return and (iv) markedly reduces the response to pig BM cells; (v) the anti-alphaGal response is completely suppressed by a myeloablative regimen if CD2+ and CD20+ cells are eliminated from the autologous BM inoculum. Furthermore, (vi) challenge with pig BM cells appears to stimulate only an anti-alphaGal antibody response without the development of other (non-alphaGal) anti-pig antibodies. We conclude that regimens used for T-cell tolerance induction can be beneficial in reducing the anti-alphaGal antibody response to porcine BM.
Assuntos
Transplante de Medula Óssea/imunologia , Dissacarídeos/imunologia , Tolerância Imunológica , Imunoglobulina G/sangue , Imunoglobulina M/sangue , Condicionamento Pré-Transplante , Transplante Heterólogo/imunologia , Animais , Papio , SuínosRESUMO
BACKGROUND: Natural antibodies (NAbs) against a terminal alpha1-3 galactosyl (alphaGal) epitope have been identified as the major human anti-pig NAbs. METHODS AND RESULTS: We used two synthetic alphaGal trisaccharides--type 6 (alphaGal6) and type 2(alphaGal2)--linked to an inert matrix to remove NAbs from human plasma in vitro. Flow cytometry indicated that an average of 85% of the NAb binding activity was depleted by adsorption with alphaGal6. By measuring the binding of NAbs to pig peripheral blood mononuclear cells and bone marrow cells, we demonstrated that alphaGal6 was more effective than alphaGal2 in removing NAbs, and the combination of alphaGal6 + alphaGal2 did not further increase removal of NAbs. The specificity of the removal of NAbs (IgM and IgG) reactive with the alphaGal epitope by alphaGal6 matrix was shown by enzyme-linked immunosorbent assay. In vivo studies in nonhuman primates compared plasma perfusion through a alphaGal6 immunoaffinity column with hemoperfusion through a pig liver for changes in blood pressure, hematocrit, platelets, and NAb adsorption. CONCLUSIONS: Both methods reduced the level of anti-pig IgM and IgG xenoreactive antibodies to nearly background, but column perfusion caused less hypotension and reduction in platelets than liver perfusion. Four pig kidneys transplanted into monkeys after column perfusion did not undergo hyperacute rejection, remaining functional for 2-10 days, with a mean functional period of 7 days, demonstrating that a pig kidney can support renal function in a primate.
Assuntos
Anticorpos/isolamento & purificação , Epitopos/imunologia , Plasma/imunologia , Transplante Heterólogo/imunologia , Trissacarídeos/imunologia , Animais , Anticorpos/imunologia , Cromatografia de Afinidade , Feminino , Rejeição de Enxerto/imunologia , Humanos , Imunoadsorventes , Técnicas In Vitro , Transplante de Rim/imunologia , Macaca fascicularis , Masculino , Papio , Plasma/química , Primatas , Sensibilidade e Especificidade , SuínosRESUMO
We have developed a nonmyeloablative preparative regimen that can produce mixed chimerism and renal allograft tolerance between MHC-disparate nonhuman primates. The basic regimen includes ATG, nonmyeloablative total-body irradiation (TBI, 300 rads), thymic irradiation (TI, 700 rads), and donor bone marrow infusion. Kidney allografts from MHC-mismatched donors were transplanted with various manipulations of the preparative regimen. Monkeys treated with the basic regimen alone (n = 2) rejected allografts by day 15. With the addition of cyclosporine (CsA) for one month (n = 3), one monkey developed multilineage mixed chimerism and renal allograft tolerance thereafter (> 430 days). To reduce the toxicity of the preparative regimen, TBI was fractionated to 150 rads on two successive days in subsequent studies. All monkeys receiving this modified regimen (n = 4) developed multilineage chimerism with fewer side effects and accepted renal allografts long-term with no further immunosuppression (196 days, 198 days, > 150 days, and > 40 days). In long-term survivors, donor-specific nonreactivity was confirmed by MLR and skin transplantation. Three monkeys treated with the basic regimen plus CsA but with only 150 rads of TBI (n = 1) or no TBI (n = 2) did not develop multilineage chimerism and grafts were rejected (day 40-50) soon after the CsA discontinuation. Monkeys treated with the same regimen, but without DBM (n = 2), rejected kidney allografts by day 52. Therefore, at least transient engraftment of DBM appears to be essential for induction of donor specific tolerance in this monkey model.
Assuntos
Sobrevivência de Enxerto/imunologia , Tolerância Imunológica , Transplante de Rim/imunologia , Macaca fascicularis/imunologia , Quimeras de Transplante/imunologia , Animais , Anticorpos Monoclonais/farmacologia , Soro Antilinfocitário/farmacologia , Transplante de Medula Óssea/imunologia , Complexo CD3/imunologia , Terapia de Imunossupressão/métodos , Transplante de Rim/métodos , Masculino , Irradiação Corporal TotalRESUMO
BACKGROUND: Efforts to achieve tolerance to transplanted pig organs in nonhuman primates by the induction of a state of mixed hematopoietic chimerism have been associated with disorders of coagulation and thrombosis. Activation of recipient vascular endothelium and platelets by porcine hematopoietic cells and/or activation of donor organ vascular endothelium and/or molecular differences between the species may play roles. Irradiation or drug therapy could possibly potentiate endothelial cell activation and/or injury. METHODS: We have investigated parameters of coagulation and platelet activation in nonhuman primates after (1) a regimen aimed at inducing mixed hematopoietic chimerism and tolerance (TIR that included total body irradiation, T cell depletion, and splenectomy; (2) pig bone marrow or pig peripheral blood mobilized progenitor cell transplantation (PCTx); and/or (3) pig organ transplantation (POTx). Five experimental groups were studied. Baboons were the recipient subjects in all groups except Group 1. Gp 1 Cynomolgus monkeys (n=6) underwent TIR + allotransplantation of hematopoietic cells and a kidney or heart or TIR + concordant xenotransplantation (using baboons as donors) of cells and a kidney; Gp 2 Baboons (n=4) underwent TIR with or without (+/-) autologous hematopoietic cell infusion; Gp 3 (n=12) PCTx+/-TIR; Gp 4 (n=5) POTx+/-TIR; Gp 5 (n=4) TIR + PCTx + POTx. Platelet counts, with plasma prothrombin time, partial thromboplastin time, fibrinogen levels, fibrin split products and/or D-dimer were measured. RESULTS: In the absence of a discordant (porcine) cellular or organ transplant (Groups 1 and 2), TIR resulted in transient thrombocytopenia only, in keeping with bone marrow depression from irradiation. PCTx alone (Group 3) was associated with the rapid development of a thrombotic thrombocytopenic (TTP)-like microangiopathic state, that persisted longer when PCTx was combined with TIR. POTx (+/-TIR) (Group 4) was associated with a gradual fall (over several days) in platelet counts and fibrinogen with disseminated intravascular coagulation (DIC); after graft excision, the DIC generally resolved. When TIR, PCTx and POTx were combined (Group 5), an initial TTP-like state was superseded by a consumptive picture of DIC within the first week, necessitating graft removal. CONCLUSIONS: Both PCTx and POTx lead to profound alterations in hemostasis and coagulation parameters that must be overcome if discordant xenotransplantation of hematopoietic cells and organs is to be fully successful. Disordered thromboregulation could exacerbate vascular damage and potentiate activation of coagulation pathways after exposure to xenogeneic cells or a vascularized xenograft.
Assuntos
Transtornos da Coagulação Sanguínea/etiologia , Transplante de Células-Tronco Hematopoéticas , Transplante de Órgãos , Trombose/etiologia , Transplante Heterólogo , Animais , Transtornos da Coagulação Sanguínea/complicações , Feminino , Rejeição de Enxerto/complicações , Rejeição de Enxerto/etiologia , Humanos , Macaca fascicularis , Masculino , Transplante de Órgãos/fisiologia , Papio , Suínos , Trombose/complicações , Quimeras de Transplante , Imunologia de Transplantes/imunologia , Tolerância ao TransplanteRESUMO
BACKGROUND: Intravascular fibrin deposition and platelet sequestration occur with porcine xenograft rejection by baboons. Disseminated intravascular coagulopathy may arise either as a direct consequence of the failure to fully deplete xenoreactive natural antibodies and block complement, or because of putative cross-species molecular incompatibilities in this discordant species combination. METHODS: Three baboons were conditioned with retrovirally transduced autologous bone marrow to induce tolerance to swine antigens. Xenoreactive natural antibodies and complement were depleted by plasmapheresis and the use of Gal alpha1-3Gal column adsorptions; baboons were then splenectomized and underwent renal xenografting from inbred, miniature pigs. Soluble complement receptor type-1 with protocol immunosuppression (mycophenolate mofetil, 15-deoxyspergualin, steroids, and cyclosporine) was administered. RESULTS: A bleeding diathesis was clinically evident from days 5 to 12 after transplantation in two baboons. Low levels of circulating C3a, C3d, and iC3b were measured despite the absence of functional circulating complement components. Profound thrombocytopenia with abnormalities in keeping with disseminated intravascular coagulopathy were observed. Prolongation of prothrombin and partial thromboplastin times was accompanied by evidence for tissue factor-mediated coagulation pathways, high levels of thrombin generation (prothrombin fragment F(1+2) production and thrombin-antithrombin complex formation), fibrinogen depletion, and production of high levels of the fibrin degradation product D-dimer. Importantly, these disturbances resolved rapidly after the excision of the rejected xenografts in two surviving animals. Histopathological examination of the rejected xenografts confirmed vascular injury, fibrin deposition, platelet deposition, and localized complement activation. CONCLUSIONS: Systemic coagulation disturbances are associated with delayed xenograft rejection.
Assuntos
Coagulação Intravascular Disseminada/complicações , Transplante de Rim/imunologia , Transplante Heterólogo , Animais , Ativação do Complemento , Proteínas do Sistema Complemento/análise , Produtos de Degradação da Fibrina e do Fibrinogênio/metabolismo , Fibrinogênio/metabolismo , Fibrinólise/fisiologia , Rejeição de Enxerto/complicações , Rim/patologia , Microscopia Eletrônica , Papio , Suínos , Condicionamento Pré-TransplanteRESUMO
BACKGROUND: Mixed allogeneic hematopoietic chimerism has previously been reliably achieved and shown to induce tolerance to fully MHC-mismatched allografts in mice and monkeys. However, the establishment of hematopoietic chimerism has been difficult to achieve in the discordant pig-to-primate xenogeneic model. METHODS: To address this issue, two cynomolgus monkeys were conditioned by whole body irradiation (total dose 300 cGy) 6 and 5 days before the infusion of pig bone marrow (BM). Monkey anti-pig natural antibodies were immunoadsorbed by extracorporeal perfusion of monkey blood through a pig liver, immediately before the intravenous infusion of porcine BM (day 0). Cyclosporine was administered for 4 weeks and 15-deoxyspergualin for 2 weeks. One monkey received recombinant pig cytokines (stem cell factor and interleukin 3) for 2 weeks, whereas the other received only saline as a control. RESULTS: Both monkeys recovered from pancytopenia within 4 weeks of whole body irradiation. Anti-pig IgM and IgG antibodies were successfully depleted by the liver perfusion but returned to pretreatment levels within 12-14 days. Methylcellulose colony assays at days 180 and 300 revealed that about 2% of the myeloid progenitors in the BM of the cytokine-treated recipient were of pig origin, whereas no chimerism was detected in the BM of the untreated control monkey at similar times. The chimeric animal was less responsive by mixed lymphocyte reaction to pig-specific stimulators than the control monkey and significantly hyporesponsive when compared with a monkey that had rejected a porcine kidney transplant. CONCLUSION: To our knowledge, this is the first report of long-term survival of discordant xenogeneic BM in a primate recipient.
Assuntos
Transplante de Medula Óssea/fisiologia , Substâncias de Crescimento/uso terapêutico , Transplante Heterólogo/fisiologia , Animais , Anticorpos/análise , Transplante de Medula Óssea/imunologia , Quimera/fisiologia , Teste de Cultura Mista de Linfócitos , Macaca fascicularis , Masculino , Especificidade da Espécie , Suínos , Porco Miniatura , Fatores de Tempo , Transplante Heterólogo/imunologiaRESUMO
BACKGROUND: Xenotransplantation would provide a solution to the current shortage of organs for transplantation. Our group has been successful in inducing tolerance in mice and monkey models of allogeneic transplantation. The present study attempts to extend the same tolerance-inducing regimen to a pig-to-baboon organ transplantation model. METHODS: Nine baboons underwent a conditioning regimen (consisting of nonmyeloablative or myeloablative whole body and thymic irradiation, splenectomy, antithymocyte globulin, pharmacologic immunosuppression and porcine bone marrow transplantation [BMTx]), which has previously been demonstrated to induce donor-specific allograft tolerance in monkeys. In addition, immunoadsorption of anti-alphaGal antibody (Ab) was performed. Four of the nine baboons received pig kidney transplants (KTx), and one also underwent repeat transplantation with an SLA-matched kidney. Two received heterotopic pig heart transplants (HTx). Three baboons underwent conditioning without organ transplantation for long-term studies of natural Ab kinetics. RESULTS: In the three baboons that received the conditioning regimen without an organ transplant, immunoadsorption reduced Ab by approximately 90%, but recovery of Ab to pretreatment level or higher occurred within 7 days. In contrast, the level of Ab remained low after organ transplant. No Ab to pig antigens other than alphaGal was detected in any baboon before or after BMTx, KTx, or HTx. No graft succumbed to hyperacute rejection. KTx function began to deteriorate within 3-6 days, with oliguria and hematuria progressing to anuria, and the kidneys were excised after 3, 6, 9, 11, and 14 days, respectively. One HTx ceased functioning at 8 days; the second baboon died with a contracting HTx at 15 days. Features of coagulopathy and thrombocytopenia developed in all six transplanted baboons (high D-dimer, prolonged prothrombin time and partial thromboplastin time, and falling fibrinogen) resulting in serious bleeding complications in two baboons, one of which died on day 9. Donor organs showed progressive acute humoral rejection with deposits of IgM, IgG, and complement; a focal mononuclear cellular infiltrate was also observed. The ureter was the earliest structure of the KTx affected by rejection, with progression to necrosis. CONCLUSIONS: This conditioning regimen prevented hyperacute rejection but was ineffective in preventing the return of Ab, which was associated with the development of acute humoral rejection with features of coagulopathy. No baboon developed anti-pig Ab other than alphaGal Ab. Further modifications of the protocol directed toward suppression of production of Ab are required to successfully induce tolerance to pig organs in baboons.
Assuntos
Anticorpos Heterófilos/imunologia , Transplante de Coração/imunologia , Tolerância Imunológica/fisiologia , Transplante de Rim/imunologia , Transplante Heterólogo/imunologia , Animais , Anticorpos Heterófilos/análise , Coagulação Sanguínea/fisiologia , Epitopos/imunologia , Feminino , Rejeição de Enxerto/fisiopatologia , Rim/imunologia , Rim/patologia , Masculino , Miocárdio/imunologia , Miocárdio/patologia , Papio , Suínos , Condicionamento Pré-Transplante , Transplante Homólogo , Ureter/imunologia , Ureter/patologiaRESUMO
BACKGROUND: The present study examined the potential role of gene therapy in the induction of tolerance to anti-porcine major histocompatibility complex (SLA) class II-mediated responses after porcine renal or skin xenografts. METHODS: Baboons were treated with a non-myeloablative or a myeloablative preparative regimen before bone marrow transplantation with autologous bone marrow cells retrovirally transduced to express both SLA class II DR and neomycin phosphotransferase (NeoR) genes, or the NeoR gene alone. Four months or more after bone marrow transplantation, the immunological response to a porcine kidney or skin xenograft was examined. Both the renal and skin xenografts were SLA DR-matched to the transgene, and recipients were conditioned by combinations of complement inhibitors, adsorption of natural antibodies, immunosuppressive therapy, and splenectomy. RESULTS: Although the long-term presence of the SLA transgene was detected in the peripheral blood and/or bone marrow cells of all baboons, the transcription of the transgene was transient. Autopsy tissues were available from one animal and demonstrated expression of the SLA DR transgene in lymphohematopoietic tissues. After kidney and skin transplantation, xenografts were rejected after 8-22 days. Long-term follow-up of control animals demonstrated that high levels of induced IgG antibodies to new non-alphaGal epitopes developed after organ rejection. In contrast, induced non-alphaGal IgG antibody responses were minimal in the SLA DR-transduced baboons. CONCLUSIONS: Transfer and expression of xenogeneic class II DR transgenes can be achieved in baboons. This therapy may prevent late T cell-dependent responses to porcine xenografts, which include induced non-alphaGal IgG antibody responses.
Assuntos
Células da Medula Óssea/fisiologia , Técnicas de Transferência de Genes , Antígenos de Histocompatibilidade Classe II/genética , Tolerância Imunológica/fisiologia , Suínos/imunologia , Transplante Heterólogo/imunologia , Animais , Transplante de Medula Óssea , Expressão Gênica/fisiologia , Antígenos de Histocompatibilidade Classe II/metabolismo , Transplante de Rim/imunologia , Papio/genética , Transplante de Pele/imunologia , Suínos/genéticaRESUMO
Graft-versus-host disease (GVHD) is an important complication of bone marrow transplantation after transplants between HLA-mismatched donor/recipient pairs. In mice, giving IL-2 post transplant decreases GVHD in this setting. We studied high-dose IL-2 therapy in pigs. Transplants were carried out after conditioning with fractionated total body radiation and cyclophosphamide. Fourteen pigs received a fully mismatched bone marrow transplant (six with IL-2; eight without IL-2), and six received a single haplotype class II mismatched transplant (three with IL-2; three without IL-2). GVHD was evaluated by skin histology. All fully mismatched recipients had severe GVHD (grade 2-3) and died within 13 to 51 days whether or not they received IL-2. Pigs receiving a one haplotype class II mismatched transplant without IL-2 developed severe skin GVHD lasting for 8-45 days; all died within 57 days. Similar pigs receiving IL-2 post transplant had no or only mild skin GVHD for less than 15 days; two are long-term survivors. Bone Marrow Transplantation (2000) 25, 47-52.
Assuntos
Transplante de Medula Óssea , Doença Enxerto-Hospedeiro/prevenção & controle , Interleucina-2/farmacologia , Animais , Transplante de Medula Óssea/efeitos adversos , Doença Enxerto-Hospedeiro/etiologia , Haplótipos , Teste de Histocompatibilidade , Interleucina-2/uso terapêutico , Camundongos , Suínos , Porco Miniatura , Transplante HomólogoRESUMO
BACKGROUND: The intensity of discordant xenograft cellular rejection makes it unlikely that safe doses of immunosuppressive drugs will alone be sufficient to permit long-term survival. We have therefore concentrated our efforts on establishing tolerance to xenogeneic organs through lymphohematopoietic chimerism and the elimination of preformed natural antibodies (nAbs). METHODS: Here we report the most recent series of 11 technically successful porcine to nonhuman primate transplantation procedures. In eight experimental animals induction therapy consisted of (1) 3 x 100 cGy nonlethal whole body irradiation (day -6 and day -5) to all animals, (2) horse anti-human thymocyte globulin (day -2, day -1, and day 0) to seven of the animals, (3) 700 cGy thymic irradiation (day -1) to five of the animals, and (4) pig bone marrow infused on day 0 (2-9 x 10(8)/cells/kg). On day 0, just before the renal xenograft, the recipient was splenectomized, and antipig nAbs were removed by means of perfusion of the monkey's blood through either a pig liver (n = 6) or a Gal-alpha (1,3)-Gal adsorption column (n = 5). There control animals did not receive this pretransplantation induction therapy but did undergo hemoperfusion and posttransplantation immunosuppression identical to the experimental animals. All 11 recipients were treated after transplantation with cyclosporin A and 15-deoxyspergualin. Recombinant pig-specific growth factors (interleukin-3 and stem cell factor) were given to six experimental animals from day 0 until the termination of the experiment. RESULTS: Analysis of recipients' sera by means of flow cytometry indicated the effective removal of immunoglobulin M and immunoglobulin G nAbs by either liver perfusion or column adsorption. In the eight experimental animals, nAb titers remained low until death (up to 15 days), but in the three control animals nAb titers increased substantially with time. The longest surviving recipient maintained excellent kidney function with creatinine levels at 0.8 to 1.3 mg/dl throughout its course. Death occurred at day 15 from complications caused by a urinary leak and pancytopenia. Histologic examination of the xenograft revealed only focal tubular necrosis and cytoplasmic vacuolization, with trace amounts of fibrin and C3 in peritubular capillaries. In this animal a fraction of the peripheral blood cells (3%) at day 7 were of pig origin as detected by pig-specific monoclonal antibodies. In addition, colony-forming assays performed on a bone marrow biopsy specimen taken at day 14 indicated that approximately 30% of the relatively few myeloid progenitors detected were of swine origin. CONCLUSIONS: We have demonstrated that our protocol is effective in the prevention of hyperacute rejection and in the maintenance of excellent function of the renal xenograft for up to 15 days. These results also indicate that at least short-term engraftment of the xenogeneic donor bone marrow cells is possible to achieve in this discordant large animal combination. Longer survivals will be required to assess the possible effect of this engraftment on induction of tolerance.
Assuntos
Anticorpos/isolamento & purificação , Transplante de Medula Óssea , Rejeição de Enxerto/prevenção & controle , Transplante de Rim , Imunologia de Transplantes , Transplante Heterólogo , Animais , Haplorrinos , Hemoperfusão , Imunoglobulina G/isolamento & purificação , Imunoglobulina M/isolamento & purificação , Suínos , Fatores de TempoRESUMO
Seedlings of paper birch (Betula papyrifera Marsh.), green ash (Fraxinus pennsylvanica Marsh.), and red pine (Pinus resinosa Ait.) fumigated with 0.2 ppm SO2 for 30 h at 30° C had higher leaf diffusive conductances (LDC) and absorbed more sulfur than seedlings fumigated at 12° C. Comparisons among the three species fumigated at the same temperature, however, do not support the view that a plant with higher LDC should absorb more SO2 than a plant with lower LDC. Mean relative growth rates ([Formula: see text]) of seedlings grown at 21° C after fumigation were variously affected by SO2. [Formula: see text] of green ash was not inhibited by SO2, but [Formula: see text] of roots of red pine seedlings was reduced by SO2, with greater inhibition in seedlings fumigated at 30° C. Root and shoot [Formula: see text] of paper birch seedlings were lowered by SO2, and effects of SO2 were about equal at both exposure temperatures. The data indicate that temperature can affect mechanisms of SO2 avoidance, tolerance, or both to various degrees in different species. Thus generalizations on the influence of exposure temperature on resistance of plants to SO2 may be inappropriate.
RESUMO
Leaf diffusion resistance (r 1) of the upper and lower leaf surfaces of several Populus clones was related to leaf water potential (ψ1), light intensity, vapor pressure deficit (VPD), and temperature by intrinsicallylinear, logarithmic multiple regression analyses. Regression equations accounted for up to 80% of variation in r 1 data. Light intensity and VPD varied among clones in importance in influencing r 1. Pronounced sensitivity of r 1 of certain clones to VPD was related to drought resistance in their parentage. Increasing r 1 was significantly positively correlated with ψ1, in apparent contradiction to prevailing concepts of stomatal response to water status, and this relationship was probably attributable to effects of other environmental variables on ψ1 and r 1. Leaf resistance decreased after a storm characterized by winds in excess of 160 km·h-1. Cuticular disruption and altered stomatal response may have been responsible for the storminduced r 1 decrease.
RESUMO
Stomata of paper birch (Betula papyrifera Marsh.) seedlings were more open at high humidity than at low humidity and responded rapidly to changes in vapor pressure deficit. SO2 at 0.2 or 0.8 µl l-1 caused partial stomatal closure. Seedlings fumigated with SO2 at 0.2 or 0.5 µl l-1 for 30 h or 0.2 µl l-1 for 75 h took up more SO2 at high than at low humidity. Differences in pollutant uptake could be explained by stomatal conductance with no need to invoke changes in mesophyll conductance. Betula seedlings were more sensitive to SO2 when fumigated at high humidity, as manifested in more leaf necrosis, increased leaf abscission, and greater growth inhibition compared to seedlings fumigated at low humidity. Amount of injury to leaves increased with rate of SO2 uptake, and inhibition of root growth increased with total SO2 uptake.
RESUMO
Flooding for up to 40 days induced morphological changes and reduced growth of 6-week-old Eucalyptus camaldulensis and Eucalyptus globulus seedlings. However, the specific responses to flooding varied markedly between these species and with duration of flooding. Both species produced abundant adventitious roots that originated near the tap root and original lateral roots, but only E. camaldulensis produced adventitious roots on submerged portions of the stem. Flooding induced leaf epinasty and reduced total dry weight increment of seedling of both species but growth of E. globulus was reduced more. In both species dry weight increment of shoots was reduced more than dry weight increment of roots, reflecting compensatory growth of adventitious roots. Adaptation to flooding appeared to be greater in E. camaldulensis than in E. globulus. the importance of formation of adventitious roots in flooding tolerance is emphasized.
RESUMO
Complete bacteriological examination of bile was carried out in 123 patients operated on for cholecystolithiasis. The most frequently found Gram-negative bacteria were E. coli and Klebsiella species. The Gram-positive organisms were most frequently Staphylococcus epidermidis, Str. viridans and Str. faecalis. Anaerobes were rarely found. The effectiveness of the antibiotics used was studied.
Assuntos
Bile/microbiologia , Colelitíase/microbiologia , Enterobacteriaceae/isolamento & purificação , Antibacterianos/farmacologia , Colelitíase/cirurgia , Meios de Cultura , Resistência Microbiana a Medicamentos , Enterobacteriaceae/efeitos dos fármacos , Humanos , Técnicas In Vitro , Cuidados Intraoperatórios , Staphylococcus epidermidis/efeitos dos fármacos , Staphylococcus epidermidis/isolamento & purificação , Streptococcus/efeitos dos fármacos , Streptococcus/isolamento & purificaçãoRESUMO
RESULTS: of morphological and tomographic (CT) studies of the skull that was found in the crypt of the Silesian Piasts in the St. Jadwiga church in Brzeg (Silesia, Poland) are presented and discussed here. The established date of burial of probably a 20-30 years old male was 16th-17th century. The analyzed skull showed premature obliteration of the major skull sutures. It resulted in the braincase deformation, similar to the forms found in oxycephaly and microcephaly. Tomographic analysis revealed gross pathology. Signs of increased intracranial pressure, basilar invagination and hypoplasia of the occipital bone were observed. Those results suggested the occurrence of the very rare Arnold-Chiari syndrome. Lesions found in the sella turcica indicated the development of pituitary macroadenoma, which resulted in the occurrence of discreet features of acromegaly in the facial bones. The studied skull was characterized by a significantly smaller size of the neurocranium (horizontal circumference 471 mm, cranial capacity â¼ 1080 ml) and strongly expressed brachycephaly (cranial index=86.3), while its height remained within the range for non-deformed skulls. A narrow face, high eye-sockets and prognathism were also observed. Signs of alveolar process hypertrophy with rotation and displacement of the teeth were noted. The skull showed significant morphological differences compared to both normal and other pathological skulls such as those with pituitary gigantism, scaphocephaly and microcephaly.