Posterior deep white matter in patients with PKU and a serum phenylalanine level of more than 8.5 mg/dL showed high signal intensity in white matter on T2-weighted and FLAIR MR images and revealed decreased ADC. We suggest that to avoid brain-restricted diffusion due to hyperphenylalanemia, patients with PKU should maintain serum phenylalanine levels of less than 8.5 mg/dL (514.2 micromol/L).

TRC8 (translocation in renal cancer from chromosome 8) isan intrinsic protein of the endoplasmic reticulum that contains a sterol-sensing domain and a RING finger motif encoding an E3 ubiquitin ligase. Here we show that TRC8 overexpression hinders sterol regulatory element-binding protein-2 (SREBP-2) processing, thereby reducing SREBP-2 target gene expression, TRC8 depletion has the opposite effect. Mutation analyses of TRC8 reveal that the ubiquitin ligase activity is dispensable for these effects. Activating transcription factor 6 (ATF6) is also processed in the Golgi by the same two proteases as those for SREBP, but ATF6 processing is not affected by TRC8. TRC8 is capable of binding both SREBP-2 and SREBP cleavage-activated protein (SCAP), thereby forming a TRC8⅐SREBP-2⅐SCAP complex. This complex formation hampers the interaction between SCAP and Sec24, one of the COPII proteins that are involved in SREBP-2 transport to the Golgi, thereby reducing SREBP-2 cleavage. TRC8 conjugated by ubiquitin is unstable, whereas the mutant TRC8, lacking the E3 ubiquitin ligase activity and only slightly modified by ubiquitin, is quite stable. TRC8 becomes stable when cells are cultured with a proteasome inhibitor or under a lipoprotein-depleted condition. Lipoprotein depletion impairs ubiquitination of TRC8. Taken together, TRC8 is a novel sterol-sensing endoplasmic reticulum membrane protein that hinders SREBP-2 processing through interaction with SREBP-2 and SCAP, regulating its own turnover rate by means of its E3 ubiquitin ligase activity.The sterol regulatory element-binding protein (SREBP) 2 family members SREBP-1 and SREBP-2 are localized on the ER as membrane proteins after being synthesized, and thereafter are processed to liberate the N-terminal halves that function as transcription factors in the nucleus. The proteolytic processing of SREBPs is highly controlled by the interaction between two ER membrane proteins, SCAP and the insulin-inducing gene (INSIG). Once the ER membrane cholesterol content increases, SCAP binds cholesterol, thereby leading to a conformational change in the membrane domain, the so-called sterol-sensing domain (SSD). This domain resembles sequences in certain other proteins that are postulated to interact with sterols: 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase, the Niemann-Pick C1 protein, and Patched (1). Subsequently, the conformational change promotes the binding of SCAP to the resident ER protein INSIG. In contrast, when the ER membrane cholesterol content decreases, the SREBP⅐SACP complex binds to COPII proteins, which cluster the complex into transport vesicles that move to the Golgi where SREBPs are processed sequentially by two proteases, designated site-1 protease (S1P) and site-2 protease (S2P). These cleavage steps release the mature forms of SREBPs that enter the nucleus and activate genes related to cholesterol and fatty acid metabolism (2).Because SREBP-1 primarily regulates the transcription of genes related to fatty acid metabolism and SREBP-2 preferentially ...

FDG PET studies performed 2 hours after intravenous injection were useful for clear visualization of liver tumors, especially metastatic liver tumors.

An efficient combination of imaging methods may be helpful for achieve the correct diagnosis.

A rare case of tentorial schwannoma in a 29-year-old male is described. The schwannoma was located within the leaves of the tentorium. MRI showed a wedge-shaped enhancing tumour. Exact nerve of origin of the tumour could not be identified. We speculate that the tumour arose from the tentorial branch of the trigeminal nerve. The literature concerning intracranial schwannoma unrelated to a major cranial nerve is reviewed.