[Immunosuppression by parenteral lipid emulsions in a model of defined immunostimulation]. / Inmunosupresión de las emulsiones lipídicas parenterales en un modelo de inmunoestimulación definida.

The immunosuppressive effect of intravenous fat emulsions with different n-3/n-6 fatty acid ratio was studied in the heterotopic rat heart allotransplant model. Twenty percent emulsions of safflower oil (n-3/n-6 = 1/370), fish oil (7.6/1), soybean oil (1/6.5) and a 1:1 mixture of safflower and fish oil (1/2, 1; oil control group) were continuously infused (9 g fat/Kg b.w./day; n = 10 each group) after transplantation until rejection. Graft survival time, subpopulations of infiltrating and circulating immunocompetent cells and Interleukin-6 release of circulating monocytes were analyzed. In the safflower oil, fish oil and soybean oil groups graft survival was prolonged to 13.3, 12.3 and 10.4 days vs. 6.7 days in the oil control group and 7.8 days in the saline control group (p < 0.01). In the two groups with the highest prolongation of graft survival the number of infiltrating cells was reduced by up to 50 percent and the peripheral blood monocyte interleukin-6 release by up to 45 percent. Beyond that, circulating T-cells were reduced in the fish oil group. Intravenous fat emulsions show a varying immunomodulatory effect in dependence of the n-3/n-6 fatty acid ratio. Both n-6 and n-3 fatty acids, if applied as main fatty acid source, exert immunosuppressive effects by a diminished infiltration, mobilisation and cytokine release of immunocompetent cells. Soybean oil with a more balanced n-3/n-6 fatty acid ratio than safflower is significantly less immunosuppressive than safflower oil and fat emulsions with a n-3/n-6 fatty acid ratio of 1/2 are immunologically neutral.

Abrogation by rapamycin of accelerated rejection in sensitized rats by inhibition of alloantibody responses and selective suppression of intragraft mononuclear and endothelial cell activation, cytokine production, and cell adhesion.

This study evaluated the efficacy and mode of action of rapamycin (RPM) in a model of accelerated (24-hr) rejection of LBNF1 cardiac allografts in specifically sensitized LEW rats. RPM treatment (0.25 mg/kg/day i.p.) between the day of sensitizing skin grafts (day -7) and subsequent heart (day 0) transplantation (Tx), abrogated fulminant rejection and prolonged cardiac allograft survival to 46 +/- 22 days (mean +/- SD, P < 0.0001). The delayed introduction of RPM until day -2 or day -1 was equally effective, whereas treatment initiated after cardiac Tx was ineffectual. Untreated accelerated rejection was associated with strong production of circulating IgM, whereas an IgG alloantibody response was not detected until after rejection was complete. RPM therapy (day -7 to -1) diminished this systemic IgM response and prevented the switch from IgM to IgG alloantibody production. Immunohistologic evaluation at 24 hr after cardiac Tx showed that compared with untreated hosts RPM treatment largely abolished intragraft cellularity, and was associated with decreased mononuclear and endothelial cell activation. Specifically, Ia and ICAM-1 upregulation was abolished, and no cells elaborating IL-2 or IFN-gamma were detected. In addition, RPM treatment prevented intragraft production of the proinflammatory cytokines IL-1 beta, IL-6, and IL-8. The effects of RPM therapy on recipient cellular responses were evaluated in vitro by mixed lymphocyte reaction. Surprisingly, the donor-specific proliferative response of cells from RPM-treated hosts at 1 or 7 days after Tx was markedly increased, compared with cells from rejecting, untreated controls, and bioassay of IL-2 within supernatants of MLR cultures showed comparable levels of IL-2 in both groups. The effects of RPM upon adhesion properties of lymph node lymphocytes were also tested in an in vitro binding assay. The binding of naive cells to sections of cardiac allografts collected from RPM-treated hosts at 24 hr post-Tx was decreased compared with that in untreated recipients. Interestingly, the binding of mononuclear cells to high endothelial venules of peripheral lymph nodes in RPM-treated hosts remained relatively high. Thus, treatment with RPM prevents and/or erases the sensitization, which otherwise leads to accelerated allograft rejection. Abrogation of allograft injury by RPM was associated with profound and long-lasting depression of host IgM and IgG alloantibody responses in the circulation, and selective downregulation of host cellular immunity and endothelial activation at the graft site. In contrast, antigen alloreactivity and endothelial adhesivity in peripheral lymphoid tissues were spared, indicating novel and potent selective effects of RPM therapy in allograft recipients.

CD4 mAb therapy modulates alloantibody production and intracardiac graft deposition in association with selective inhibition of Th1 lymphokines.

The accelerated (24 h) rejection of (LEWxBN)F1 cardiac allografts (Tx) in LEW rats sensitized with BN skin grafts, is abrogated with CD4 mAb (BWH-4) administration between skin (day -7) and heart (day 0) transplantation (Tx survival ca. 11 days, p < 0.0001). This study analyzed the effects of CD4-targeted therapy upon host IgG and IgM alloantibody (allo-Ab) within the serum by two-color flow cytometry, and within the Tx, by immunohistology. These data were correlated with mRNA and protein production profiles of Th1 (IL-2, IFN-gamma) vs Th2 (IL-4) specific cytokines (polymerase chain reaction and/or immunohistology). Skin grafts elicited a strong systemic IgM allo-Ab response, which peaked at the time of cardiac Tx rejection at 24 h. It was associated with extensive deposits of IgM on Tx endothelium. Treatment with BWH-4 mAb diminished circulating IgM allo-Ab levels, and only low levels of IgM could be detected at the Tx site. Conversely, the low circulating IgG allo-Ab levels during rejection at 24 h in untreated recipients were accompanied by a strong labeling for intra-Tx IgG. BWH-4 mAb therapy did not prevent totally the switch of the IgM to IgG, but the IgG allo-Ab response was earlier, less intense and more transient than in untreated recipients. Accelerated rejection triggered sequential lymphokine mRNA expression in cardiac Tx, with the peak of transcription for IL-2 (6-12 h) preceding that for IL-4 (24 h). Interestingly, although CD4 targeted therapy virtually ablated the induction of IL-2 mRNA, it preserved transcription of the IL-4 gene. BWH-4 mAb therapy decreased otherwise abundant intra-Tx IL-2 and IFN-gamma, but allowed a vigorous elaboration of IL-4, confirming the translation of mRNA to the protein in vivo. Thus, CD4 mAb-mediated abrogation of accelerated cardiac Tx injury correlates with suppression of Th1 responses (depressed IL-2 and IFN-gamma production), but sparing of the Th2 function (enhanced IL-4 elaboration). Indeed, CD4 mAb-induced allo-Ab depression and immunosuppressive effects may reflect selective targeting of proinflammatory Th1-like cells and the multifaceted effects of IL-4 produced by unopposed Th2-like cells.

Rapamycin treatment depresses intragraft expression of KC/MIP-2, granzyme B, and IFN-gamma in rat recipients of cardiac allografts.

Rapamycin (RPM) treatment prevents accelerated rejection of cardiac allografts in sensitized rats. The prominent feature of this brisk 24-h rejection, which includes a panoply of both cellular and humoral host immune responses, is a massive infiltration of rejecting grafts with neutrophils. In this study we tested the hypothesis that RPM-mediated therapeutic effects on accelerated rejection may be linked to decreased expression of protein encoded by gro/melanoma-growth stimulatory activity gene (KC) and macrophage inflammatory protein-2 (MIP-2) genes, the operational rat homologues of the human intercrine-alpha cytokines with proinflammatory IL-8-like neutrophil activation/chemotactic properties. The induction of these genes was then correlated with mRNA profiles encoding for Th1-selective IFN-gamma and CTL-specific granzyme B proteins. Northern blot analysis of RNA from cardiac allografts of sensitized untreated recipients, revealed maximal levels of KC and MIP-2 mRNA at 3 to 6 h after transplantation. In contrast, IFN-gamma mRNA, which was at most very weakly expressed at 3 h, peaked between 6 to 12 h. As with IFN-gamma, granzyme B transcripts were undetectable at 3 h, but peaked around the time of actual graft rejection at 24 h. RPM therapy abrogated accelerated rejection and prolonged cardiac allograft survival to ca. 46 days. This effect was associated with markedly reduced expression of KC and MIP-2 mRNA in the first 24 h as well as at 7 and 34 days after transplantation. Moreover, RPM completely blocked intragraft appearance of granzyme B and IFN-gamma mRNA in long term cardiac allografts. Immunohistologic analysis has revealed that accelerated rejection was associated with extensive neutrophil infiltration, which peaked at 18 to 24 h. At this time, leukocytes and endothelium were intensely stained for IL-8 and IFN-gamma antibodies. In contrast, the allografts from RPM-treated hosts showed essentially no neutrophil infiltration and minor, focal staining for IL-8 and IFN-gamma. This study demonstrates an association between the early expression of genes for proinflammatory IL-8-dependent neutrophil chemotactic activity, and later expression of genes associated with activation/effector activity of CTL and NK cells. It also documents a novel effect of RPM in vivo, which results in the suppression of intragraft IL-8-like and CTL-dependent mRNA/protein production and diminished neutrophil infiltration; these may contribute to the striking efficacy of RPM therapy in sensitized graft recipients.

Induction of nonspecific x-irradiation-resistant suppressor cell activity in vivo and prolongation of vascularized allograft survival by SK&F 105685, a novel immunomodulatory azaspirane.

SK&F 105685 is a novel azaspirane with immunosuppressive activity in animal models of autoimmune disease. This study evaluates the efficacy and mechanism of action of the compound in rat recipients of cardiac allografts. Short-term SK&F 105685 therapy (20 mg/kg/day by gavage) proved effective both in the pretreatment (days -14 to -8 or -7 to -1; allograft at day 0) and treatment (days 0 to 6) protocols, with cardiac allograft survival prolonged to 14-17 days (acute rejection = 7 days; P < 0.001). SK&F 105685 pretreatment exerted at least additive effects with subtherapeutic CsA (1.5 mg/kg/day x 7 days i.m.) given after transplantation, with 50% of allografts surviving > 50 days. SK&F 105685 therapy diminished the immunohistological features of acute rejection, with the cellular infiltrate suppressed and the induction of IL-2/transferrin receptors, and elaboration of IL-2/IFN-gamma essentially abolished, as compared with the grafts in untreated hosts. These correlated with normal frequency of CD4, CD5, CD8 phenotype subsets and B cells in recipient lymphoid organs, as shown by flow microfluorimetry. Adoptive transfer of untreated or x-irradiated (2000 rads) spleen cells from SK&F 105685-modulated hosts significantly prolonged the survival of donor-specific or third-party test cardiac allografts to 10-15 days, suggesting the presence of nonspecific x-irradiation-resistant suppressor cells in the transferred inoculum. Their activity could be enriched by Percoll density centrifugation and screened by the ability to inhibit Con A-driven proliferation of normal cells in the coculture assay. The light-density x-irradiation-resistant spleen cell fraction (1.07 g/ml) was consistently and significantly more suppressive than the heavy-density (1.09 g/ml) interface, or the corresponding unseparated cells. Thus SK&F 105685 therapy abrogates rejection response and significantly prolongs the survival of vascularized cardiac allografts in rats. This effect is associated with selective depression of host alloreactivity/immune activation at the graft site, and simultaneous induction of suppressor cells in recipient spleen, comparable to natural or nonspecific suppressor cells generated by TLI. This unique activity profile is consistent with the concept that SK&F 105685 should be considered as a critical chemical adjunct in novel therapeutic strategies representing TLI-equivalent.

[Diagnosis and therapy of metastasis-induced pathologic fractures]. / Diagnostik und Therapie metastasenbedingter pathologischer Frakturen.

Improved survival rates of cancer patients have led to an increase in the incidence of metastatic disease of the bone. Normal load and minimal trauma may result in pathological fractures. The malignant diseases most commonly diagnosed were breast cancer, bronchial carcinoma and hypernephroma. The majority of the patients treated were female. The average interval observed between diagnosis of primary malignant disease and occurrence of the pathological fracture was 2.8 years. The purpose of the surgical procedure is to achieve immediate and lasting stability and ultimately to increase and restore the quality of life. Immediate postoperative mobilization and early functional treatment are an indispensable part of the management of pathologic fractures. If possible extensive bone destructions involving the risk of fracture should be stabilized prophylactically. Specific techniques of composite osteosyntheses of fractures in metastatic disease of the bone are presented.

The transitional polyp of the colorectal mucosa.

45 cases of small polypoid lesions occurring in the colorectal mucosa free of inflammatory or neoplastic disease are presented. The lesions were removed at colonoscopy and displayed neither features of hyperplastic (metaplastic) polyps nor features of a neoplastic proliferation. Morphologically these small lesions were characterized by elongated and widened crypts, enlarged goblet cells with an increase in mucous production. Histochemically there was a reversion of the usual pattern of mucin production in the colorectal mucosa: an increase in sialomucin production and a decrease in sulfomucins. Thus these lesions demonstrate the same morphological and histochemical features as the transitional mucosa surrounding carcinoma and adenoma in the large bowel. These "transitional" polyps could represent an early step in the development of neoplastic processes in the colorectal mucosa and precede adenomas.

Morphology and histochemistry of the mucosa surrounding small oligotubular adenomas of the large bowel.

The transitional mucosa surrounding adenomas and carcinomas of the large bowel is characterized by a reversion of mucus secretion from sulphomucin to sialomucin and a hyperplasia of crypts and epithelial cells. The specificity of this phenomenon is still a controversial issue. Therefore we studied 72 oligotubular adenomas of the large bowel and the adjacent mucosa by means of histochemistry and morphometry. The peak of sialomucin production is found within the crypts immediately adjacent to the adenoma, whereas the more distant crypts secrete less. The cellular diameter and the depth of the crypts behave in a similar manner, they decrease with increasing distance from the adenoma, still being much higher than in the normal mucosa. The crypt depth correlates well to sialomucin production. The existence of the transitional mucosa around small oligotubular adenomas may indicate, that this mucosal change is not merely secondary to the presence of carcinoma but may be of importance as a precursor lesion of neoplastic changes of the colon and rectum.