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ABSTRACTConsidering how Hamburg-Wilhelmsburg has been stigmatized for decades, and recently targeted for redevelopment, you would hardly guess from the outside that the neighborhood is beloved by racialized long-time residents, and considered to be a warm, welcoming Heimat: a space of belonging, where you do not have to justify your presence. This identification is tied to the neighborhood’s racialization; the qualities that have been labeled as problems to be transformed through social mix make it a space of relative safety and security, in a context in which many residents experience attempted exclusions from German identity. Based on interviews with racialized long-time residents, contextualized within racialization in Germany, the racialized displaceability embedded in social mix policy, the contested meaning of Heimat, and the experiences of Wilhelmsburg residents with migrantization, I argue that this emphatic claim is a strength that is threatened by the current process of social mix gentrification.

In this study we have examined the use of low-dose γ-irradiation for the reduction of islet immunogenicity in the strong allogeneic combination of WAG rat islets transplanted into diabetic AUG recipients. First, we determined that γ-irradiation reduced immunogenicity in vitro by use of a modified MLR with WAG islets as stimulators and AUG splenocytes as responders. We then determined the maximum dose of γ-irradiation that could be used (250 rads) before islet function was affected. As 250 rads islet pretreatment alone was ineffective in prolonging allograft survival, we combined the pretreatment with a short course (days 0, 1, 2; 30 mg/kg) of cyclosporine. We found that CsA was only effective in significantly prolonging allograft survival when given subcutaneously in olive oil. The CsA treatment alone gave a significantly prolonged survival time for the islet allografts (median, 37 days vs. 6 days for controls), but when combined with the 250 rads islet pretreatment a synergistic effect was seen with 100 becoming long-term survivors (>100 days). The longterm surviving AUG rats from both the CsA alone group and the CsA plus 250 rads pretreated islets group were challenged with WAG dendritic cells (DC). The islets from the 250 rads pretreated group were subsequently rejected (day 6) while the CsA alone group were not affected. The role of low dose γ-irradiation when combined with CsA treatment of islet graft recipients in inducing specific unresponsiveness will be discussed.

Although preliminary studies have shown that the severely combined immunodeficient (SCID)-hu mouse can reject allo tissue, they have also highlighted the current limitations of the SCID-hu model. These limitations are the need for unambiguous identification of human cells in the SCID mouse and the variability of the reconstitution efficiency. The purpose of this study was to follow the kinetics of SCID-hu reconstitution, comparing human splenocytes (SC) with peripheral blood leucocytes (PBL) to ascertain whether the presence of post-thymic progenitor cells in SC improved the efficiency of reconstitution. SCID mice were injected intraperitoneally with 5 × 107 PBL from five normal volunteers, and with 5 × 107 SC from 5 organ donor spleens. Two animals per donor were culled on weeks 2, 4, 8, and 16, and the frequency and level of SCID-hu reconstitution assessed by flow cytometric analysis of peritoneal cells and splenic leucocytes. Total serum immunoglobulin levels were measured fortnightly to follow the kinetics of B lymphocyte reconstitution. A marked degree of variability was seen in the frequency and extent of reconstitution, regardless of the source of lymphocytes. However, in comparison with PBL, human SC, predominantly T cells, were able to persist and increase in number, migrating from the peritoneal cavity to secondary lymphoid tissue. We conclude that human SC provide a better source of human lymphoid cells for SCID reconstitution than PBL.

The use of a bovine serum albumin BSA density gradient for isolation of rat pancreatic Islets of Langerhans after collagenase digestion has been compared with the standard Ficoll separation technique. The criteria studied were islet yield insulin extraction of the islet interfaces and pellet, purity of preparation amylase content of the islet preparation, insulin release characteristics, and the result of isologous transplantation in diabetic rats. The islet interface of the BSA gradient contained 62.2 of the total insulin, whereas the corresponding interface of the Ficoll gradient contained only 36.6 P<0.001. The amylase content of the Ficollseparated islet preparation was 6133 UL, as opposed to 1230 UL with BSA P<0.001. BSAisolated islets gave similar insulin release characteristics to nondensitygradientisolated islets, whereas Ficollseparated islets showed suboptimal insulin release. Singledonorsinglerecipient transplantation was successfully performed with BSAisolated islets whereas multiple donors were required with Ficollseparated islets. Thus significantly improved results were found with the bovine serum albumin density gradient separation in all criteria and consequently the use of this gradient represents an advance in islet isolation techniques.

Recounts how the author tries to cope with the death of a friend during a skiing expedition to the Alps. Preparations for the trip; Camp-out on the mountain after being trapped by a blizzard; Injuries sustained during the trip; Emotional aspects of coping with a friend's loss. INSET: When a friend dies, by Jeannie Kim..