| 1. |
- Baliakas, Panagiotis, et al.
(författare)
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Clinical effect of stereotyped B-cell receptor immunoglobulins in chronic lymphocytic leukaemia: a retrospective multicentre study
- 2014
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Ingår i: The Lancet Haematology. - 2352-3026. ; 1:2, s. 74-84
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Tidskriftsartikel (refereegranskat)abstract
- Background About 30% of cases of chronic lymphocytic leukaemia (CLL) carry quasi-identical B-cell receptor immunoglobulins and can be assigned to distinct stereotyped subsets. Although preliminary evidence suggests that B-cell receptor immunoglobulin stereotypy is relevant from a clinical viewpoint, this aspect has never been explored in a systematic manner or in a cohort of adequate size that would enable clinical conclusions to be drawn. Methods For this retrospective, multicentre study, we analysed 8593 patients with CLL for whom immunogenetic data were available. These patients were followed up in 15 academic institutions throughout Europe (in Czech Republic, Denmark, France, Greece, Italy, Netherlands, Sweden, and the UK) and the USA, and data were collected between June 1, 2012, and June 7, 2013. We retrospectively assessed the clinical implications of CLL B-cell receptor immunoglobulin stereotypy, with a particular focus on 14 major stereotyped subsets comprising cases expressing unmutated (U-CLL) or mutated (M-CLL) immunoglobulin heavy chain variable genes. The primary outcome of our analysis was time to first treatment, defined as the time between diagnosis and date of first treatment. Findings 2878 patients were assigned to a stereotyped subset, of which 1122 patients belonged to one of 14 major subsets. Stereotyped subsets showed significant differences in terms of age, sex, disease burden at diagnosis, CD38 expression, and cytogenetic aberrations of prognostic significance. Patients within a specific subset generally followed the same clinical course, whereas patients in different stereotyped subsets-despite having the same immunoglobulin heavy variable gene and displaying similar immunoglobulin mutational status-showed substantially different times to first treatment. By integrating B-cell receptor immunoglobulin stereotypy (for subsets 1, 2, and 4) into the well established Dohner cytogenetic prognostic model, we showed these, which collectively account for around 7% of all cases of CLL and represent both U-CLL and M-CLL, constituted separate clinical entities, ranging from very indolent (subset 4) to aggressive disease (subsets 1 and 2). Interpretation The molecular classification of chronic lymphocytic leukaemia based on B-cell receptor immunoglobulin stereotypy improves the Dohner hierarchical model and refines prognostication beyond immunoglobulin mutational status, with potential implications for clinical decision making, especially within prospective clinical trials.
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| 2. |
- Barbu, Andreea, et al.
(författare)
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Blood flow in endogenous and transplanted pancreatic islets in anesthetized rats : Effects of lactate and pyruvate
- 2012
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Ingår i: Pancreas. - 0885-3177 .- 1536-4828. ; 41:8, s. 1263-1271
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: The objective of this study was to evaluate the effects of exogenously administered lactate and pyruvate on blood perfusion in endogenous and transplanted islets. METHODS: Anesthetized Wistar-Furth rats were given lactate or pyruvate intravenously, and regional blood perfusion was studied 3 or 30 minutes later with a microsphere technique. Separate rats received a 30-minute infusion of pyruvate or lactate into the portal vein before blood flow measurements. We also administered these substances to islet-implanted rats 4 weeks after transplantation and measured graft blood flow with laser Doppler flowmetry. The expression of monocarboxylate transporter 1 and lactate dehydrogenase A was analyzed. RESULTS: The expression of monocarboxylate transporter 1 and lactate dehydrogenase A was markedly up-regulated in transplanted as compared with endogenous islets. Administration of pyruvate, but not lactate, increased mesenteric blood flow after 3 minutes. Pyruvate decreased mesenteric blood flow after 30 minutes, whereas lactate decreased only islet blood flow. These responses were absent in transplanted animals. A continuous intraportal infusion of lactate or pyruvate increased selectively islet blood flow but did not affect blood perfusion of transplanted islets. CONCLUSIONS: Lactate and pyruvate affect islet blood flow through effects mediated by interactions between the liver and the nervous system. Such a response can help adjust the release of islet hormones during excess substrate concentrations.
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| 3. |
- Dedic, Dina, et al.
(författare)
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Analysis of lignin and extractives in the oak wood of the 17th century warship Vasa
- 2014
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Ingår i: Holzforschung. - : Walter de Gruyter GmbH. - 0018-3830 .- 1437-434X. ; 68:4, s. 419-425
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Tidskriftsartikel (refereegranskat)abstract
- The wood in the 17th century Swedish warship Vasa is weak. A depolymerization of the wood's cellulose has been linked to the weakening, but the chemical mechanisms are yet unclear. The objective of this study was to analyze the lignin and tannin moieties of the wood to clarify whether the depolymerization of cellulose via ongoing oxidative mechanisms is indeed the main reason for weakening the wood in the Vasa. Lignin was analyzed by solid-state nuclear magnetic resonance [cross-polarization/magic-angle spinning (CP/MAS) C-13 NMR] and by means of wet chemical degradation (thioacidolysis) followed by gas chromatography-mass spectrometry (GC-MS) of the products. No differences could be observed between the Vasa samples and the reference samples that could have been ascribed to extensive lignin degradation. Wood extracts (tannins) were analyzed by matrix- assisted laser desorption ionization (MALDI) combined with time-of-flight (TOF) MS and C-13 NMR spectroscopy. The wood of the Vasa contained no discernible amounts of tannins, whereas still-waterlogged Vasa wood contained ellagic acid and traces of castalagin/vescalagin and grandinin. The results indicate that the condition of lignin in the Vasa wood is similar to fresh oak and that potentially harmful tannins are not present in high amounts. Thus, oxidative degradation mechanisms are not supported as a primary route to cellulose depolymerization.
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| 4. |
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| 5. |
- Dedic, Dina, et al.
(författare)
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Chemical analysis of wood extractives and lignin in the oak wood of the 380 year old Swedish warship Vasa
- 2011
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Konferensbidrag (refereegranskat)abstract
- In order to map the source of oxalic acid in the interior wood of the Vasa ship, an analysis of wood extractives (tannins) was conducted. Samples used for analysis were PEG-impregnated dry Vasa wood, waterlogged Vasa wood and a reference material (fresh oak). The wood material was ground and extracted with an acetone/water-mixture. In the reference sample, several types of tannins were found such as the isomers castalagin/vescalagin and grandinin and their dimmers roburin A/D and roburin B/C respectively. The results have been confirmed by NMR spectroscopy and MALDI-TOF. The interior of the waterlogged Vasa wood contained small amounts of monomers, whereas the dry, PEG treated Vasa revealed no discernible amounts of hydrolysable tannins or other easily soluble compounds. Furthermore, an analysis of lignin was made by means of chemical degradation (thioacidolysis). A decrease in the amount of β-O-4 bonds in the lignin structure would imply a formation of easily oxidized free phenolics. The products were analyzed by GC-MS, which revealed no dramatic differences between the Vasa samples and the reference. The results were confirmed by CP/MAS NMR by analyzing the differences in the aromatic region (150∼160 ppm) as well as the carbonyl region (190∼200 ppm).
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| 6. |
- Fred, Rikard G., et al.
(författare)
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The human insulin mRNA is partly translated via a cap- and eIF4A-independent mechanism
- 2011
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Ingår i: Biochemical and Biophysical Research Communications - BBRC. - : Elsevier BV. - 0006-291X .- 1090-2104. ; 412:4, s. 693-698
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to investigate whether cap-independent insulin mRNA translation occurs in human pancreatic islets at basal conditions, during stimulation at a high glucose concentration and at conditions of nitrosative stress. We also aimed at correlating cap-independent insulin mRNA translation with binding of the IRES trans-acting factor polypyrimidine tract binding protein (FTB) to the 5'-UTR of insulin mRNA. For this purpose, human islets were incubated for 2 h in the presence of low (1.67 mM) or high glucose (16.7 mM). Nitrosative stress was induced by addition of 1 mM DETA/NO and cap-dependent mRNA translation was inhibited with hippuristanol. Insulin biosynthesis rates were determined by radioactive labeling and immunoprecipitation. PTB affinity to insulin mRNA 5'-UTR was assessed by a magnetic micro bead pull-down procedure. We observed that in the presence of 1.67 mM glucose, approximately 70% of the insulin mRNA translation was inhibited by hippuristanol. Corresponding value from islets incubated at 16.7 mM glucose was 93%. DETA/NO treatment significantly decreased the translation of insulin by 85% in high glucose incubated islets, and by 50% at a low glucose concentration. The lowered insulin biosynthesis rates of DETA/NO-exposed islets were further suppressed by hippuristanol with 55% at 16.7 mM glucose but not at 1.67 mM glucose. Thus, hippuristanol-induced inhibition of insulin biosynthesis was less pronounced in DETA/NO-treated islets as compared to control islets. We observed also that PTB bound specifically to the insulin mRNA 5'-UTR in vitro, and that this binding corresponded well with rates of cap-independent insulin biosynthesis at the different conditions. In conclusion, our studies show that insulin biosynthesis is mainly cap-dependent at a high glucose concentration, but that the cap-independent biosynthesis of insulin can constitute as much as 40-100% of all insulin biosynthesis during conditions of nitrosative stress. These data suggest that the pancreatic beta-cell is able to uphold basal insulin synthesis at conditions of starvation and stress via a cap- and eIF4A-independent mechanism, possibly mediated by the binding of FIB to the 5'-UTR of the human insulin mRNA.
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| 7. |
- Gao, Xiang, et al.
(författare)
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Effects of Mn-DPDP and manganese chloride on hemodynamics and glucose tolerance in anesthetized rats
- 2014
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Ingår i: Acta Radiologica. - : SAGE Publications. - 0284-1851 .- 1600-0455. ; 55:3, s. 328-334
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Tidskriftsartikel (refereegranskat)abstract
- Background Previous studies have demonstrated that magnetic resonance imaging may be a method of choice to visualize transplanted pancreatic islets. However, contrast agents may interfere with microcirculation and affect graft function. Purpose To evaluate the effects manganese-containing contrast media on regional blood flow and glucose tolerance. Material and Methods Anesthetized rats were injected intravenously with MnCl2 (10 mu M/kg body weight) or Mn-DPDP (Teslascan; 5 mu M/kg body weight). Blood flow measurements were made with a microsphere technique 10min later. In separate animals vascular arteriolar reactivity in isolated, perfused islets was examined. Furthermore, an intraperitoneal glucose tolerance test was performed in separate rats. Results Glucose tolerance was unaffected by both agents. No changes in regional blood flow were seen after administration of Mn-DPDP, except for an increase in arterial liver blood flow. MnCl2 increased all blood flow values except that of the kidney. MnCl2, but not Mn-DPDP, caused a vasoconstriction in isolated rat islet arterioles but only at very high doses. Conclusion Mn-DPDP administration does not affect glucose tolerance or regional blood flow, besides an increase in arterial hepatic blood flow, and may therefore be suitable for visualization of islets.
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| 8. |
- Gao, Xiang, et al.
(författare)
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Short-term glucosamine infusion increases islet blood flow in anesthetized rats
- 2013
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Ingår i: ISLETS. - : Informa UK Limited. - 1938-2014 .- 1938-2022. ; 5:5, s. 201-206
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Tidskriftsartikel (refereegranskat)abstract
- Impaired glucose tolerance and type 2 diabetes in rodents are associated with increased islet blood flow. If this is important for modulation of the endocrine function is at present unknown. We evaluated if glucosamine infusion, which induces peripheral insulin resistance and glucose intolerance, could be used to acutely increase islet blood flow. We infused anaesthetized Sprague-Dawley rats for 2 h with glucosamine (6 mg/kg body weight), in some cases followed by glucose administration. The former induced a 2-fold increase in serum insulin concentrations while plasma glucose remained unchanged. In vitro an augmented insulin response to hyperglycemia and decreased insulin content in batch type islet incubations with glucosamine for 24 h were seen. After 2 h glucosamine exposure in vitro, insulin release was decreased. In vivo glucosamine infusion increased islet blood flow, without affecting other regional blood flow values. Glucose increased islet blood flow to the same extent in control and glucosamine-infused rats. When exposed to 10 mmol/L glucosamine arterioles of isolated perfused islets showed a 10% dilation of their vascular smooth muscle. Thus, application of this model leads to acute hyperinsulinemia in vivo but a decreased insulin release in vitro, which suggests that effects not located to beta cells are responsible for the effects seen in vivo. An increased islet blood flow in previously healthy animals was also seen after glucose administration, which can be used to further dissect the importance of blood flow changes in islet function.
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| 9. |
- Lai, Enyin, et al.
(författare)
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Blood lipids affect rat islet blood flow regulation through beta(3)-adrenoceptors
- 2014
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Ingår i: American Journal of Physiology. Endocrinology and Metabolism. - : American Physiological Society. - 0193-1849 .- 1522-1555. ; 307:8, s. E653-E663
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Tidskriftsartikel (refereegranskat)abstract
- Pancreatic islet blood perfusion varies according to the needs for insulin secretion. We examined the effects of blood lipids on pancreatic islet blood flow in anesthetized rats. Acute administration of Intralipid to anesthetized rats increased both triglycerides and free fatty acids, associated with a simultaneous increase in total pancreatic and islet blood flow. A preceding abdominal vagotomy markedly potentiated this and led acutely to a 10-fold increase in islet blood flow associated with a similar increase in serum insulin concentrations. The islet blood flow and serum insulin response could be largely prevented by pretreatment with propranolol and the selective beta(3)-adrenergic inhibitor SR-59230A. The nitric oxide synthase inhibitor NG-nitro-L-arginine methyl ester prevented the blood flow increase but was less effective in reducing serum insulin. Increased islet blood flow after Intralipid administration was also seen in islet and whole pancreas transplanted rats, i.e., models with different degrees of chronic islet denervation, but the effect was not as pronounced. In isolated vascularly perfused single islets Intralipid dilated islet arterioles, but this was not affected by SR-59230A. Both the sympathetic and parasympathetic nervous system are important for the coordination of islet blood flow and insulin release during hyperlipidemia, with a previously unknown role for beta(3)-adrenoceptors.
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| 10. |
- Pettersson, Ulrika, et al.
(författare)
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Two-week treatment with the β3-adrenoceptor antagonist SR59230A normalizes the increased pancreatic islet blood flow in type 2 diabetic GK rats
- 2012
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Ingår i: Diabetes, obesity and metabolism. - : Wiley. - 1462-8902 .- 1463-1326. ; 14:10, s. 960-962
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Tidskriftsartikel (refereegranskat)abstract
- The Goto-Kakizaki (GK) rat, a type 2 diabetes model, has increased pancreatic islet and white adipose tissue (WAT) blood flow, and this can be normalized by acute administration of SR59230A, a beta(3)-adrenoceptor antagonist. We now implanted osmotic pumps which allowed a constant release of saline or SR59230A (0.6 mg/kg x day) for 2 weeks. A decrease in islet blood flow was seen also after 2 weeks of continuous SR59230A treatment in the GK rat. However, no improvement in glucose tolerance was seen in the GK rats. Neither did SR59230A affect insulin secretion from isolated islets in vitro. WAT blood flow was not affected by the 2-week SR59230A treatment. Thus, the increased islet blood flow seen in the GK rat can be normalized for up to 2 weeks, which opens the possibilities for further studies on the long-term functional role on the islet blood flow increase in this type 2 diabetes model.
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| 11. |
- Rydgren, Tobias, et al.
(författare)
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Administration of IL-1 Trap prolongs survival of transplanted pancreatic islets to type 1 diabetic NOD mice
- 2013
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Ingår i: Cytokine. - : Elsevier BV. - 1043-4666 .- 1096-0023. ; 63:2, s. 123-129
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Tidskriftsartikel (refereegranskat)abstract
- We previously reported that IL-1 Trap (a hybrid molecule consisting of the extracellular domain of IL-1 receptor accessory protein and IL-1 receptor type 1 arranged inline and fused to the Fc-portion of IgG1) can protect rat pancreatic islets in vitro against noxious effects induced by IL-1 beta. In this study we tested the effect of administration of a murine IL-1 Trap on the recurrence of disease (ROD) model in non-obese diabetic (NOD) mice. Spontaneously diabetic female NOD mice received implantation of a curative number (600) of syngeneic pancreatic islets beneath their left kidney capsule from young healthy NOD mouse donors. Once a day, the mice were injected subcutaneously with IL-1 Trap (30 mg/kg bodyweight), or an equimolar dose Fc-control protein (8.4 mg/kg bodyweight) or saline. The treatments were maintained until ROD (i.e. a blood glucose value >= 11.1 mM for 2 consecutive days) or until 5 days after transplantation. 3 out of 11 mice treated with IL-1 Trap showed a significantly increased graft survival compared to all other mice, and analysis of relative cytokine mRNA levels in isolated spleen cells showed elevated IL-4 mRNA levels, but no differences in FoxP3 or iNOS staining of grafts, from mice treated with IL-1 Trap, at both endpoints, compared to both control groups. Administration of IL-1 Trap counteracts islet cell destruction in the NOD mouse model of type 1 diabetes. In part this could be due to a shift towards Th2 cytokine production seen in IL-1 Trap treated animals.
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| 12. |
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| 13. |
- Sandberg, Monica, et al.
(författare)
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Effects of cyclooxygenase inhibition on insulin release and pancreatic islet blood flow in rats
- 2014
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Ingår i: Upsala Journal of Medical Sciences. - : Uppsala Medical Society. - 0300-9734 .- 2000-1967. ; 119:4, s. 316-323
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Tidskriftsartikel (refereegranskat)abstract
- Objectives. To examine the effects of inhibition of cyclooxygenase (COX) on islet hormone secretion in vitro and on pancreatic islet blood flow in vivo. Methods. Insulin release was measured in a static incubation system of islets isolated from Wistar-F rats after inhibition of COX-1 and COX-2 with SC 560 (COX-1), FR 122047 (COX-1), rofecoxib (COX-2), or indomethacin (both COX-1 and COX-2). In other rats organ blood flow values were measured with a microsphere technique during both normo- and hyperglycemia after administration of these enzyme inhibitors. Results. Serum insulin values were lower after pretreatment with a COX-1 inhibitor or a non-selective COX inhibitor in both control and glucose-injected rats in vivo, whereas COX-2 inhibition had no such effects. However, inhibition of COX had only minor effects on insulin release in vitro. Inhibition of COX affected neither total pancreatic nor islet blood flow in normoglycemic rats. Hyperglycemia caused an increase in both these flow values and in the duodenum. The increase in total pancreatic and duodenal blood flow was prevented by inhibition of COX-2 or non-selective COX inhibition. However, no effects on islet blood flow were seen after COX inhibition. Conclusion. Inhibition of COX affects insulin release and blood glucose concentrations in vivo. However, COX inhibition has only minor effects on pancreatic islet blood flow, but prevents the glucose-induced increase in total pancreatic blood flow.
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| 14. |
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| 15. |
- Sandberg, Monica, et al.
(författare)
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The alpha(2)-Adrenoceptor Antagonist Yohimbine Normalizes Increased Islet Blood Flow in GK Rats : A Model of Type 2 Diabetes
- 2013
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Ingår i: Hormone and Metabolic Research. - : Georg Thieme Verlag KG. - 0018-5043 .- 1439-4286. ; 45:3, s. 252-254
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Tidskriftsartikel (refereegranskat)abstract
- Overexpression of alpha(2A)-adrenoceptors contributes to type 2 diabetes in GK rats. We aimed to investigate if alpha(2)-adrenoceptor inhibition affected islet blood flow in these rats. Anesthetized GK and Wistar-F rats were given the alpha(2)-adrenoceptor inhibitor yohimbine (2.5 mg/kg BW) intravenously. The GK rats had higher blood glucose and serum insulin concentrations than WF rats. Yohimbine affected neither of these values in WF rats, but decreased blood glucose and increased serum insulin concentrations in GK rats. Total pancreatic and islet blood flows, measured with microspheres, were increased in GK when compared to WF rats. Yohimbine affected none of the blood flow values in WF rats, whereas islet blood flow in GK rats was reduced to values similar to those seen in WF rats. Overexpression of alpha(2)-adrenoceptors may contribute to the increased islet blood flow seen in GK rats, and may be eligible for pharmacologic intervention.
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| 16. |
- Sjögren, Peter, et al.
(författare)
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SEMI-SUBMERSIBLE GRAVITY BASED HYBRID STRUCTURE – AN ALTERNATIVE TO JACKET AND TOPSIDE PLATFORMS
- 2014
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Ingår i: Proceedings of the International Conference on Offshore Mechanics and Arctic Engineering - OMAE, vol. 8B, 2014. - 9780791845516
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Konferensbidrag (refereegranskat)abstract
- The aim of this research is to present the result from a case study comparing a semi-submersible gravity based hybrid structure and a jacket topside structure for two offshore wind farm converter station projects. The cases are analyzed from a transportation and installation perspective. Converter stations enable the conversion from alternating to direct current, more efficiently bringing generated wind energy to shore. Out of the project process phases e.g. planning, engineering, fabrication, transport, installation and commissioning; transportation and installation are two of the most demanding during offshore platform projects. The weight and size of an offshore platform require specialized equipment, vessels and marine contractors’ expertise to be transported and installed. The risks associated with transportation and installation (T&I) operations are related to health, safety and environment, and T&I operations are also sensitive to any disturbance e.g. accidents and delays. Many interdependencies between disciplines in the project execution process may result in consequential and immediate impact, should an activity not follow the plan and thus the risk of cost overruns increases. In an attempt to circumvent risks related to heavy lifts offshore and consequently mitigate the corresponding risks, a new platform concept has been developed a Norwegian EPC –company and a Swiss converter station manufacturer, a semi-submersible gravity based hybrid, SSGBH. The subjects presented in this paper include the general principles of the SSGBH concept and in what way risk associated with T&I operations are reduced. This paper present the platform concepts, data gathered from interviews, archival data and direct observations. Their pros and cons are presented in an objective way, while concluding that platform concepts of this kind are and should be highly customized, as should the concept selection.
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| 17. |
- Spégel, Peter, et al.
(författare)
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Glucose-dependent insulinotropic polypeptide lowers branched chain amino acids in hyperglycemic rats
- 2014
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Ingår i: Regulatory Peptides. - : Elsevier BV. - 0167-0115 .- 1873-1686. ; 189, s. 11-16
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Tidskriftsartikel (refereegranskat)abstract
- Hypersecretion of the incretin hormone glucose-dependent insulinotropic polypeptide (GIP) has been associated with obesity and glucose intolerance. This condition has been suggested to be linked to GIP resistance. Besides its insulinotropic effect, GIP also directly affects glucose uptake and lipid metabolism. This notwithstanding, effects of GIP on other circulating metabolites than glucose have not been thoroughly investigated. Here, we examined effects of infusion of various concentrations of GIP in normo- and hyperglycemic rats on serum metabolite profiles. We found that, despite a decrease in serum glucose levels (-26%, p < 0.01), the serum metabolite profile was largely unaffected by GIP infusion in normoglycemic rats. Interestingly, levels of branched chain amino acids and the ketone body beta-hydroxybutyrate were decreased by 21% (p < 0.05) and 27% (p < 0.001), respectively, in hyperglycemic rats infused with 60 ng/ml GIP. Hence, our data suggest that GIP provokes a decrease in BCAA levels and ketone body production. Increased concentrations of these metabolites have been associated with obesity and T2D.
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| 18. |
- Svensson, Johanna, et al.
(författare)
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High Vascular Density and Oxygenation of Pancreatic Islets Transplanted in Clusters Into Striated Muscle
- 2011
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Ingår i: Cell Transplantation. - 0963-6897 .- 1555-3892. ; 20:5, s. 783-788
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Tidskriftsartikel (refereegranskat)abstract
- Pancreatic islet transplantation is presently almost exclusively performed using the intraportal route for transplantation into the liver. However, islets at this site are poorly revascularized and, when also considering the poor long-term results of clinical islet transplantation, there has in recent years emerged an increased interest to evaluate alternative sites for islet transplantation. Striated muscle is easily accessible and has for decades been used for autotransplantation of parathyroid glands. Moreover, it is almost the only tissue in the adult where physiological angiogenesis occurs. The present study tested the hypothesis that striated muscle would provide good conditions for revascularization and oxygenation of transplanted islets. Because we previously have observed similar revascularization of islets implanted to the renal subcapsular site and intraportally into the liver, islets grafted to the kidney were for simplicity besides native islets used for comparison. Islets grafted into muscle were found to have three times more blood vessels than corresponding islets at the renal subcapsular site at 2 month follow-up, but still less vascular numbers than native islets. The oxygen tension in 2-month-old intramuscular islet grafts was sixfold higher than in corresponding renal subcapsular grafts, and 70% of that in native islets. However, the oxygenation of surrounding muscle was only 50% of that in renal cortex, and connective tissue constituted a larger proportion of the intramuscular than the renal subcapsular grafts, suggesting exaggerated early islet cell death at the former site. We conclude that the intramuscular site provides excellent conditions for vascular engraftment, but that interventions to improve early islet survival likely are needed before clinical application. Such could include bioengineered matrices that not only spatially disperse the islet, but also could provide local supply of oxygen carriers, growth and survival factors, strategies that are much more easily applied at the intramuscular than the intrahepatic site.
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