A miRNA signature for defining aggressive phenotype and prognosis in gliomas

Gliomas represent a disparate group of tumours for which there are to date no cure. Thus, there is a recognized need for new diagnostic and therapeutic approaches based on increased understanding of their molecular nature. We performed the comparison of the microRNA （miRNA） profile of 8 WHO grade II gliomas and 24 higher grade tumours （2 WHO grade III and 22 glioblastomas） by using the Affymetrix GeneChip miRNA Array v. 1.0. A relative quantification method （RT-qPCR） with standard curve was used to confirm the 22 miRNA signature resulted by array analysis. The prognostic performances of the confirmed miRNAs were estimated on the Tumor Cancer Genome Atlas （TCGA） datasets. We identified 22 miRNAs distinguishing grade II gliomas from higher grade tumours. RT-qPCR confirmed the differential expression in the two patients＇groups for 13 out of the 22 miRNAs. The analysis of the Glioblastoma Multiforme （GBM） and Lower Grade Glioma （LGG） datasets from TCGA demonstrated the association with prognosis for 6 of those miRNAs. Moreover, in the GBM dataset miR-21 and miR-210 were predictors of worse prognosis in both univariable and multivariable Cox regression analyses （ HR 1.19, P = O. 04, and HR 1.18, P = 0. 029 respectively）. Our results support a direct contribution of miRNAs to glioma cancerogenesis and suggest that miR-21 and miR-210 may play a role in the aggressive clinical behaviour of glioblastomas.     

Identification of Candida species in the clinical laboratory: a review of conventional,commercial, and molecular techniques

In healthy individuals, Candida species are considered commensal yeasts of the oral cavity. However, these microorganisms can also act as opportunist pathogens, particularly the so‐called non‐albicans Candida species that are increasingly recognized as important agents of human infection. Several surveys have documented increased rates of C. glabrata, C. tropicalis, C. guilliermondii, C. dubliniensis, C. parapsilosis, and C. krusei in local and systemic fungal infections. Some of these species are resistant to antifungal agents. Consequently, rapid and correct identification of species can play an important role in the management of candidiasis. Conventional methods for identification of Candida species are based on morphological and physiological attributes. However, accurate identification of all isolates from clinical samples is often complex and time‐consuming. Hence, several manual and automated rapid commercial systems for identifying these organisms have been developed, some of which may have significant sensitivity issues. To overcome these limitations, newer molecular typing techniques have been developed that allow accurate and rapid identification of Candida species. This study reviewed the current state of identification methods for yeasts, particularly Candida species.     

Metabolic basis of ethanol-induced hepatic and pancreatic injury in hepatic alcohol dehydrogenase deficient deer mice.

Alcoholic liver disease (ALD) and alcoholic pancreatitis (AP) are major diseases causing high mortality and morbidity among chronic alcohol abusers. Neutral lipid accumulation (steatosis) is an early stage of ALD or AP and progresses to inflammation and other advanced stages of diseases in a subset of chronic alcohol abusers. However, the mechanisms of alcoholic steatosis leading to ALD and AP are not well understood. Chronic alcohol abuse impairs hepatic alcohol dehydrogenase (ADH, a major enzyme involved in ethanol oxidative metabolism) and facilitates nonoxidative metabolism of ethanol to fatty acid ethyl esters (FAEEs, nonoxidative metabolites of ethanol). These esters are implicated in the pathogenesis of various alcoholic diseases and shown to cause hepatocellular and pancreatitis-like injury. Ethanol exposure is known to increase synthesis of FAEEs by several-fold in the livers and pancreata of rats pretreated with hepatic ADH inhibitor. Therefore, studies were undertaken to evaluate hepatocellular and pancreatic injury in hepatic ADH-deficient (ADH(-)) deer mice versus ADH-normal (ADH(+)) deer mice fed ethanol (4% wt/vol) via Lieber-DeCarli liquid diet for 60 days. A significant mortality was found in ethanol-fed ADH(-) deer mice (11 out of 18) versus ADH(+) deer mice (1 out of 16); most of the deaths occurred during the first 2 weeks of ethanol exposure. The surviving animals, sacrificed at the end of 60th day, showed distinct changes in hepatic and pancreatic histology and several-fold increases in nonoxidative metabolism of ethanol in ethanol-fed ADH(-) versus ADH(+) deer mice. Extensive vacuolization with displacement or absence of nucleus in some hepatocytes, and significant increase in hepatic neutral lipids were found in ethanol-fed ADH(-) versus ADH(+) deer mice. Ultrastructural changes showed perinuclear space, edema, presence of apoptotic bodies and disintegration, and/or dilatation of endoplasmic reticulum (ER) in the pancreata of ethanol-fed ADH(-) deer mice. FAEE levels were significantly higher in ADH(-) versus ADH(+) deer mice, approximately four-fold increases in the livers and seven-fold increases in the pancreata. Ethyl esters of oleic, linoleic, and arachidonic acids were the major FAEEs detected in ethanol-fed groups. The role of FAEEs in pancreatic lysosomal fragility is reflected by higher activity of cathepsin B (five-fold) in ethanol-fed ADH(-) versus ADH(+) deer mice. Although the present studies clearly indicate a metabolic basis of ethanol-induced hepatic and pancreatic injury, detailed dose- and time-dependent toxicity studies in this ADH(-) deer mouse model could reveal further a better understanding of mechanism(s) of ethanol-induced hepatic and pancreatic injuries.     

Resistance of Copenhagen rats to chemical induction of glutathione S- transferase 7-7-positive liver foci

Copenhagen (Cop) rats are completely resistant to the chemical induction of mammary adenocarcinomas, but their susceptibility to hepatocarcinogenesis is virtually unknown. Rat liver is a well- characterized and easily manipulated tissue in which to study carcinogenesis. Therefore, if Cop rats are resistant to hepatocarcinogenesis, studies into resistance mechanisms may be feasible. Male Cop and F344 rats, 7-8 weeks old, were initiated using either N-nitrosodiethylamine (DEN) (200 mg/kg, i.p.) or a two-thirds partial hepatectomy (PH) followed by N-methyl-N-nitrosourea (MNU) (60 mg/kg, i.p.). The rats were then promoted using a modified resistant hepatocyte (RH) protocol (a combination of four doses of 2- acetylaminofluorene (2-AAF) and a single dose of CCl4 that provides a selective mitotic stimulus for initiated cells). Six weeks after initiation the rats were killed and liver sections were stained for glutathione S-transferase 7-7 (GST 7-7), a marker for putative preneoplastic hepatocytes. Cop rats were found to be highly resistant, having a approximately 9- and approximately 27-fold smaller percentage of liver area occupied by GST 7-7-positive foci than susceptible F344 rats following initiation by DEN and MNU respectively. Furthermore, gross liver nodules did not form in any of the Cop rats, whereas all F344 rat livers contained nodules. Hepatic necrosis caused by DEN during initiation, and CCl4 during promotion is necessary to stimulate compensatory hepatocyte division. We demonstrated that these agents do indeed increase serum transaminase levels and produce histologic evidence of necrosis in Cop rats. In order for liver foci to grow rapidly in the RH protocol, the surrounding normal hepatocytes must be mito-inhibited by 2-AAF. We found that the degree of mito-inhibition of normal hepatocytes by 2-AAF is the same in Cop and F344 rats. These results show that the Cop rat is highly resistant to the chemical induction of putative preneoplastic liver foci and nodules.      

Desmoplastic fibroma of the proximal ulna

A young man presented with desmoplastic fibroma in the proximal ulna. This rare tumour was treated by curettage and bone grafting.     

Neuronal nitric oxide synthase and N-methyl-D-aspartate neurons in experimental carbon monoxide poisoning

We measured changes in nitric oxide (NO) concentration in the cerebral cortex during experimental carbon monoxide (CO) poisoning and assessed the role for N-methyl-d-aspartate receptors (NMDARs), a glutamate receptor subtype, with progression of CO-mediated oxidative stress. Using microelectrodes, NO concentration was found to nearly double to 280 nM due to CO exposure, and elevations in cerebral blood flow, monitored as laser Doppler flow (LDF), were found to loosely correlate with NO concentration. Neuronal nitric oxide synthase (nNOS) activity was the cause of the NO elevation based on the effects of specific NOS inhibitors and observations in nNOS knockout mice. Activation of nNOS was inhibited by the NMDARs inhibitor, MK 801, and by the calcium channel blocker, nimodipine, thus demonstrating a link to excitatory amino acids. Cortical cyclic GMP concentration was increased due to CO poisoning and shown to be related to NO, versus CO, mediated guanylate cyclase activation. Elevations of NO were inhibited when rats were infused with superoxide dismutase and in rats depleted of platelets or neutrophils. When injected with MK 801 or 7-nitroindazole, a selective nNOS inhibitor, rats did not exhibit CO-mediated nitrotyrosine formation, myeloperoxidase (MPO) elevation (indicative of neutrophil sequestration), or impaired learning. Similarly, whereas CO-poisoned wild-type mice exhibited elevations in nitrotyrosine and myeloperoxidase, these changes did not occur in nNOS knockout mice. We conclude that CO exposure initiates perivascular processes including oxidative stress that triggers activation of NMDA neuronal nNOS, and these events are necessary for the progression of CO-mediated neuropathology.     

Pineal germinoma: MR imaging

Magnetic resonance (MR) imaging characteristics of pineal germinomas are described in seven patients imaged with MR and computed tomography (CT). In patients with symptoms of an enlarging process in the quadrigeminal plate cistern, MR imaging was as sensitive as CT scanning in detecting the mass. MR imaging did not detect a normal-sized, calcified neoplastic gland. Germinoma, germinoma with embryonal cell carcinoma elements, and pineoblastoma demonstrated different MR signal characteristics. Although direct coronal and sagittal MR images were useful in defining the relationship of the tumor to the posterior third ventricle, Sylvian aqueduct, and vein of Galen, the ease, rapidity, and sensitivity of CT scanning suggest that CT should remain the modality of choice for initial evaluation and screening of the pineal region, especially in the younger pediatric population, in whom detection of calcification may provide the only clue of an abnormality.