肾移植后伴骨质疏松症患者血清骨代谢指标的变化

应用放射免疫分析法和免疫放射分析法对７例已确诊有骨质疏松症的骨移植患者进行血清骨代谢指标检测。结果表明患者成骨细胞活性指标（血清特异性骨碱怀磷酸酶、骨钙素和Ｉ型前胶原蛋白羧基末端前肽）和破骨细胞功能指标（血清Ｉ型胶原交联羧基末端肽）明显高于正常对照组，患者血清甲状旁腺素和２５羟维生素Ｄ水平正常。提示肾移植后伴骨质疏松症患者的成骨细胞活性和破骨细胞活性明显增高，但无继发性甲状旁腺功能亢进和维生素Ｄ代     

Ein unterer Grenzwert für das Alter des Universums

Summary Measurements of the radiogenic⁸⁷Sr/⁸⁷Rb ratio of the chondritic meteorite Forest City are discussed in the light of a new determination of the half-life of⁸⁷Rb. Earlier conclusions are confirmed.     

Forecasting German GDP using alternative factor models based on large datasets

This paper discusses the forecasting performance of alternative factor models based on a large panel of quarterly time series for the German economy. One model extracts factors by static principal components analysis; the second model is based on dynamic principal components obtained using frequency domain methods; the third model is based on subspace algorithms for state‐space models. Out‐of‐sample forecasts show that the forecast errors of the factor models are on average smaller than the errors of a simple autoregressive benchmark model. Among the factor models, the dynamic principal component model and the subspace factor model outperform the static factor model in most cases in terms of mean‐squared forecast error. However, the forecast performance depends crucially on the choice of appropriate information criteria for the auxiliary parameters of the models. In the case of misspecification, rankings of forecast performance can change severely. Copyright © 2007 John Wiley & Sons, Ltd.     

Subgroup-specific structural variation across 1,000 medulloblastoma genomes

Medulloblastoma, the most common malignant paediatric brain tumour, is currently treated with nonspecific cytotoxic therapies including surgery, whole-brain radiation, and aggressive chemotherapy. As medulloblastoma exhibits marked intertumoural heterogeneity, with at least four distinct molecular variants, previous attempts to identify targets for therapy have been underpowered because of small samples sizes. Here we report somatic copy number aberrations (SCNAs) in 1,087 unique medulloblastomas. SCNAs are common in medulloblastoma, and are predominantly subgroup-enriched. The most common region of focal copy number gain is a tandem duplication of SNCAIP, a gene associated with Parkinson's disease, which is exquisitely restricted to Group 4α. Recurrent translocations of PVT1, including PVT1-MYC and PVT1-NDRG1, that arise through chromothripsis are restricted to Group 3. Numerous targetable SCNAs, including recurrent events targeting TGF-β signalling in Group 3, and NF-κB signalling in Group 4, suggest future avenues for rational, targeted therapy.     

Empty MHC class I molecules come out in the cold

Major histocompatibility complex (MHC) class I molecules present antigen by transporting peptides from intracellularly degraded proteins to the cell surface for scrutiny by cytotoxic T cells. Recent work suggests that peptide binding may be required for efficient assembly and intracellular transport of MHC class I molecules, but it is not clear whether class I molecules can ever assemble in the absence of peptide. We report here that culture of the murine lymphoma mutant cell line RMA-S at reduced temperature (19-33 degrees C) promotes assembly, and results in a high level of cell surface expression of H-2/beta 2-microglobulin complexes that do not present endogenous antigens, and are labile at 37 degrees C. They can be stabilized at 37 degrees C by exposure to specific peptides known to interact with H-2Kb or Db. Our findings suggest that, in the absence of peptides, class I molecules can assemble but are unstable at body temperature. The induction of such molecules at reduced temperature opens new ways to analyse the nature of MHC class I peptide interactions at the cell surface.     

5β-Reduction of [14C]cholesterol by human feces in vitro: Nonspecific inhibition by sugars

Zusammenfassung Nachweis, dass die 5-Reduktion von [¹⁴C]Cholesterol homogenisierter Fäces durch Milch, Laktose und Galaktose gehemmt wurde, wobei die Hemmung unspezifisch war und auch mit anderen Zuckern erzielt werden konnte.     

Seven prostate cancer susceptibility loci identified by a multi-stage genome-wide association study

Prostate cancer (PrCa) is the most frequently diagnosed male cancer in developed countries. We conducted a multi-stage genome-wide association study for PrCa and previously reported the results of the first two stages, which identified 16 PrCa susceptibility loci. We report here the results of stage 3, in which we evaluated 1,536 SNPs in 4,574 individuals with prostate cancer (cases) and 4,164 controls. We followed up ten new association signals through genotyping in 51,311 samples in 30 studies from the Prostate Cancer Association Group to Investigate Cancer Associated Alterations in the Genome (PRACTICAL) consortium. In addition to replicating previously reported loci, we identified seven new prostate cancer susceptibility loci on chromosomes 2p11, 3q23, 3q26, 5p12, 6p21, 12q13 and Xq12 (P = 4.0 × 10(-8) to P = 2.7 × 10(-24)). We also identified a SNP in TERT more strongly associated with PrCa than that previously reported. More than 40 PrCa susceptibility loci, explaining ～25% of the familial risk in this disease, have now been identified.