Early steroids after pediatric liver transplantation protect against T-cell-mediated rejection: Results from the ChilSFree study

Steroid-free immunosuppression protocols gained popularity in pediatric liver transplantation (pLT) after the introduction of IL-2-receptor blockade for induction therapy. We analyzed the clinical and immunologic outcome data of the multicenter prospective observational ChilSFree study to compare the impact of steroid-free versus steroid-containing immunosuppressive therapy following pLT in a real-life scenario. Two hundred forty-six children [55.3% male, age at pLT median: 2.4 (range: 0.2-17.9) y] transplanted for biliary atresia (43%), metabolic liver disease (9%), acute liver failure (4%), hepatoblastoma (9%), and other chronic end-stage liver diseases (39%) underwent immune monitoring and clinical data documentation over the first year after pLT. Patient and graft survival at 1 year was 98.0% and 92.7%, respectively. Primary immunosuppression was basiliximab induction followed by tacrolimus (Tac) monotherapy (55%), Tac plus steroid tapering over 3 months (29%), or cyclosporine and steroid tapering (7%). One center used intraoperative steroids instead of basiliximab followed by Tac plus mycophenolate mofetil (7% of patients). N = 124 biopsy-proven T-cell-mediated rejections were documented in n = 82 (33.3%) patients. T-cell-mediated rejection occurred early (median: 41 d, range: 3-366 d) after pLT. Patients initially treated with Tac plus steroids experienced significantly fewer episodes of rejection than patients treated with Tac alone (chi-square p <0.01). The use of steroids was associated with earlier downregulation of proinflammatory cytokines interferon (IFN)-γ, Interleukin (IL)-6, CX motif chemokin ligand (CXCL)8, IL-7, and IL-12p70. Both primary immunosuppression with Tac plus steroids and living donor liver transplantation were independent predictors of rejection-free survival 1 year after pLT on logistic regression analysis. Adjunctive steroid therapy after pLT leads to earlier suppression of the post-pLT proinflammatory response and significantly reduced rejection rates during the first year after pLT (15.9%). Fifty-one percent of patients initially treated without steroids remain steroid-free over the first 12 months without rejection.

Effect of seeding technique and scaffold material on bone formation in tissue-engineered constructs

The aim of the present study was to test the hypothesis that both scaffold material and the type of cell culturing contribute to the results of in vivo osteogenesis in tissue-engineered constructs in an interactive manner. CaCO3 scaffolds and mineralized collagen scaffolds were seeded with human trabecular bone cells at a density of 5 x 10(6) cells/cm(3) and were left to attach under standard conditions for 24 h. Subsequently, they were submitted to static and dynamic culturing for 14 days (groups III and IV, respectively). Dynamic culturing was carried out in a continuous flow perfusion bioreactor. Empty scaffolds and scaffolds that were seeded with cells and kept under standard conditions for 24 h served as controls (groups I and II, respectively). Five scaffolds of each biomaterial and from each group were implanted into the gluteal muscles of rnu rats for 6 weeks. Osteogenesis was assessed quantitatively by histomorphometry and expression of osteocalcin (OC) and vascular endothelial growth factor (VEGF) was determined by immunohistochemistry. CaCO3 scaffolds exhibited 15.8% (SD 3.1) of newly formed bone after static culture and 22.4% (SD 8.2) after dynamic culture. Empty control scaffolds did not show bone formation, and scaffolds after 24 h of standard conditions produced 8.2% of newly formed bone (SD 4.0). Differences between the controls and the scaffolds cultured for 14 days were significant, but there was no significant difference between static and dynamic culturing. Mineralized collagen scaffolds did not show bone formation in any group. There was a significant difference in the expression of OC within the scaffolds submitted to static versus dynamic culturing in the CaCO3 scaffolds. VEGF expression did not show significant differences between static and dynamic culturing in the two biomaterials tested. It is concluded that within the limitations of the study the type of biomaterial had the dominant effect on in vivo bone formation in small tissue-engineered scaffolds. The culture period additionally affected the amount of bone formed, whereas the type of culturing may have had a positive effect on the expression of osteogenic markers but not on the quantity of bone formation.

Bone formation in trabecular bone cell seeded scaffolds used for reconstruction of the rat mandible

This study tested whether different in vitro cultivation techniques for tissue-engineered scaffolds seeded with human trabecular bone cells affect in vivo bone formation when implanted into critical-size defects in rat mandibles. Human trabecular cells were isolated and seeded into three types of scaffolds (porous CaCO(3), mineralized collagen, porous tricalcium phosphate). Four in vitro groups were produced: empty control scaffolds incubated with cell culture medium for 24 h; scaffolds seeded with trabecular bone cells, cultivated under static conditions for 24 h; scaffolds seeded with trabecular bone cells, cultivated for 14 days under static conditions; scaffolds seeded with trabecular bone cells, cultivated for 14 days in a continuous flow perfusion bioreactor. The scaffolds were implanted press fit into non-healing defects, 5 mm diameter, in rat mandibles. After 6 weeks the presence of human cells was assessed; none were detected. Histomorphometric evaluation showed that neither seeding human trabecular bone cells nor the culturing technique increased the amount of early bone formation compared with the level provided by osteoconductive bone ingrowth from the defect edges. It is concluded that human bone marrow stroma cells in tissue-engineered scaffolds and associated in vitro technology are difficult to test in the mandible in animal models.

Crystal structure of rel-(3aR,6aS)-6-methyl-3,6a-diphenyl-3a,4,6,6atetrahydro- isoxazolo[5,4-c]isoxazole, C17H16N2O2

C17H16N2O2, orthorhombic, Pca21 (no. 29), a = 5.6406(8) Å, b = 30.292(4) Å, c = 16.925(3) Å, V = 2891.9 Å3, Z = 8, Rgt(F) = 0.084, wRref(F2) = 0.236, T = 293 K.

Crystal structure of rel-(3aR,4S,6aS)-4-chloromethyl-6-methyl-3,6adiphenyl- 3a,4,6,6a-tetrahydro-isoxazolo[5,4-c]isoxazole, C18H17ClN2O2

C18H17ClN2O2, monoclinic, P121/c1 (no. 14), a = 12.2900(9) Å, b = 13.325(1) Å, c = 10.482(1) Å, β = 102.69(1)°, V = 1674.7 Å3, Z = 4, Rgt(F) = 0.053, wRref(F2) = 0.162, T = 293 K.

Crystal structure of (2RS)-2-bromomethyl-4,4-dimethyl-3,4-dihydro- 2H-pyrrole 1-oxide hemi(hydrobromide), C7H12BrNO · ½HBr

C7H12.50Br1.50NO, monoclinic, C12/c1 (no. 15), a = 22.249(2) Å, b = 8.571(1) Å, c = 11.083(1) Å, β = 117.037(8)°, V = 1882.5 Å3, Z = 8, Rgt(F) = 0.043, wRref(F2) = 0.116, T = 293 K.

Crystal structure of rel-(2R,3S)-2-bromomethyl-3-phenyl-3,4-dihydro- 2H-pyrrole 1-oxide, C11H12BrNO

C11H12BrNO, orthorhombic, Pccn (no. 56), a = 13.1274(7) Å, b = 23.309(1) Å, c = 6.995(1) Å, V = 2140.4 Å3, Z = 8, Rgt(F) = 0.065, wRref(F2) = 0.207, T = 293 K.

Crystal structure of dimethyl (2S,3R,3aS,4S,5R,6R)-6-iodomethyl-4,5- isopropylidenedioxy-hexahydropyrrolo[1,2-b]pyrazole-2,3-dicarboxylate, C14H21IN2O6

C14H21IN2O6, orthorhombic, P212121 (no. 19), a = 9.748(1) Å, b = 11.701(2) Å, c = 15.552(2) Å, V = 1773.9 Å3, Z = 4, Rgt(F) = 0.050, wRref(F2) = 0.120, T = 293 K.

Crystal structure of rel-(2R,3aS)-2-bromomethyl-3,3a,4,5,6,7-hexahydro- 2H-indole 1-oxide, C9H14BrNO

C9H14BrNO, monoclinic, C1c1 (no. 9), a = 6.079(1) Å, b = 19.095(4) Å, c = 8.169(1) Å, β = 95.23(1)°, V = 944.2 Å3, Z = 4, Rgt(F) = 0.047, wRref(F2) = 0.120, T = 293 K.

Crystal structure of (3S,4S)-4,5-O-cyclohexylidene-4,5-dihydroxy-3- methylamino-pentanoic acid hydrochloride, (C12H22NO4)Cl

C12H22ClNO4, monoclinic, P1211 (no. 4), a = 6.2327(3) Å, b = 7.9360(3) Å, c = 14.1536(5) Å, β = 99.709(4)°, V = 690.1 Å3, Z = 2, Rgt(F) = 0.042, wRref(F2) = 0.115, T = 293 K.

Different mRNA expression profile during tumor progression in a well-differentiated liposarcoma--A microdissection approach

Like malignant fibrous histiocytoma (MFH), dedifferentiated liposarcoma represents a distinct subtype of liposarcoma and is characterized by an abrupt transition from well-differentiated liposarcoma (WDL) to highgrade dedifferentiated liposarcoma (DDL) . In addition, specific cytogenetic aberrations support the close biological relationship between WDL and DDL. Recent observations indicated the significance of cell cycle aberrations in tumor progression from the low-malignant, well differentiated to its dedifferentiated form, the prognosis of which is poor. Thus, alterations of mdm2 and p53 genes belong to the most frequently reported alterations in these two subtypes of liposarcoma. In previous investigations, we reported that loss of heterozygosity at the Rb gene locus, telomerase activity, hTERT, and c-Myc expression were associated with tumor progression in liposarcomas. In this study, we report on a case of a WD/DDL, in which both tumor components were separated using laser microdissection (P.A.L.M.) for the investigation of hTERT mRNA expression on a LightCycler. Macroscopically selected and histologically proven cryosections of low malignant and highly malignant tumor areas were cytogenetically investigated to confirm the diagnosis and to find additional chromosomal alterations with tumor progression.