Integrated Metabolomic and Transcriptomic Analysis of Modified Nucleosides for Biomarker Discovery in Clear Cell Renal Cell Carcinoma.

Clear cell renal cell carcinoma (ccRCC) accounts for ~75% of kidney cancers. The biallelic inactivation of the von Hippel-Lindau tumor suppressor gene (VHL) is the truncal driver mutation of most cases of ccRCC. Cancer cells are metabolically reprogrammed and excrete modified nucleosides in larger amounts due to their increased RNA turnover. Modified nucleosides occur in RNAs and cannot be recycled by salvage pathways. Their potential as biomarkers has been demonstrated for breast or pancreatic cancer. To assess their suitability as biomarkers in ccRCC, we used an established murine ccRCC model, harboring Vhl, Trp53 and Rb1 (VPR) knockouts. Cell culture media of this ccRCC model and primary murine proximal tubular epithelial cells (PECs) were investigated by HPLC coupled to triple-quadrupole mass spectrometry using multiple-reaction monitoring. VPR cell lines were significantly distinguishable from PEC cell lines and excreted higher amounts of modified nucleosides such as pseudouridine, 5-methylcytidine or 2'-O-methylcytidine. The method's reliability was confirmed in serum-starved VPR cells. RNA-sequencing revealed the upregulation of specific enzymes responsible for the formation of those modified nucleosides in the ccRCC model. These enzymes included Nsun2, Nsun5, Pus1, Pus7, Naf1 and Fbl. In this study, we identified potential biomarkers for ccRCC for validation in clinical trials.

The use of recombinant activated factor VII in neurosurgery.

BACKGROUND: Bleeding complications in neurosurgery often take alarming proportions without major hemodynamic effect or impairment of coagulation physiology because severe neurologic deficits are to be expected. Any measures used to stabilize or normalize coagulation are therefore of great interest. Administration of packed red cells, fresh frozen plasma, and platelet concentrates is associated with volume loading, which is suspected to multiply the secondary brain damage, for example, by the development of an edema. In this respect, the administration of rFVIIa may develop into a new option associated with low-volume administration. CASE DESCRIPTIONS: We report on 5 neurosurgical patients to whom rFVIIa was given at doses of 51 to 202 microg/kg of body weight for the treatment of severe intraoperative bleeding (n = 3) or as prophylaxis of bleeding (n = 2). The operation was completed successfully in all patients after administration of rFVIIa, with stabilization of the coagulation status. CONCLUSION: Therefore, reported cases constitute an approach in treatment and prophylaxis of bleeding complications in neurosurgery. There are reports of thromboembolic events in use of rFVIIa, particularly in unlabeled use. But according to our findings and current literature, there is no evidence of higher risk of thromboembolic adverse events in treatment with rFVIIa. However, the number of patients presented does not allow any final assessment to be made as to whether the properties of rFVIIa are of particular benefit for neurosurgical patients. Further studies with appropriate study design are required to verify effects observed in this investigation.

The use of waterjet dissection in endoscopic neurosurgery. Technical note.

Waterjet dissection enables vessel preservation and a reduction in intraoperative blood loss. Because even minimal bleeding should be avoided during neuroendoscopy, the waterjet device may be a particularly valuable tool in such procedures. The authors used this instrument in experimental endoscopic procedures in 20 cadaveric porcine brains and clinically in four patients with obstructive hydrocephalus. A precise and accurate septostomy was achieved in all of the pig brains. In two patients the hydrocephalus was due to intraventricular hemorrhage, in one a posterior fossa tumor, and in one a cystic craniopharyngioma. In all patients the surgical view was kept clear with waterjet irrigation and suction. Using a pressure setting of 10 bars, the waterjet device successfully perforated the cyst wall of the craniopharyngioma in one patient and the floor of the third ventricle in three patients. The use of the waterjet device in selected endoscopic procedures appears safe, and may help reduce intraoperative bleeding. However, further studies are needed to confirm the utility of the waterjet tool in endoscopy.

High-resolution peptide mapping of cerebrospinal fluid: a novel concept for diagnosis and research in central nervous system diseases.

Peptides, such as many hormones, cytokines and growth factors play a central role in biological processes. Furthermore, as degradation products and processed forms of larger proteins they are part of the protein turnover. Thus, they can reflect disease-related changes in an organism's homeostasis in several ways. Since two-dimensional gel electrophoresis is restricted to analysis and display of proteins with relative molecular masses above 5000, we developed Differential Peptide Display (DPD), a new technology for analysis and visualization of peptides. Here we describe its application to cerebrospinal fluid of three subjects without a disease of the central nervous system (CNS) undergoing routine myelography and of two patients suffering from a primary CNS lymphoma. Peptides with a relative molecular mass below 20000 were extracted and analysed by a combination of chromatography and mass spectrometry. The peptide pattern of a sample was depicted as a multi-dimensional peptide mass fingerprint with each peptide's position being characterized by its molecular mass and chromatographic behaviour. Such a fingerprint of a CNS sample consists of more than 6000 different signals. Data analysis of peptide patterns from patients with CNS lymphoma compared to controls revealed obvious differences regarding the peptide content of the samples. By analysing peptides within a mass range of 750-20000, DPD extends 2D gel electrophoresis, thus offering the chance to investigate CNS diseases on the level of peptides. This represents a new approach for diagnosis and possible therapy.

Fracture of the occipital condyle caused by minor trauma in child.

We report a case of fractured occipital condyle caused by minor trauma accompanied by light pain on palpation at the lateral cervical trigonum. A 15-year-old boy complained of nuchal pain, particularly pain on palpation at the left lateral cervical trigonum in the absence of neurologic deficits after head deceleration trauma. Computed tomography demonstrated a unilateral nonluxated fracture of the occipital condyle. Owing to consequent immobilization by means of cervical orthosis, pain disappeared after the first 48 hours. Follow-up examination 4 weeks later showed no neurologic deficits. The boy had no severe impairment of movements at the cervical spine.