Multiparametric-MRI as a comprehensive study in evaluation,characterization & local staging of urinary bladder carcinomas

Objectives

To evaluate role of multiparametric-MRI as comprehensive technique for determining local staging of UB cancer and predicting histological grading of lymphadenopathy.

Fear, ambivalence, and liminality: key concepts in refusal to donate an organ after brain death

ABSTRACT: The refusal to donate an organ is a phenomenon in need of exploration and explanation. This article refers to the major fear of becoming an organ donor in relation to a global culture perspective and to the Halacha (Jewish law). A theoretical critique about the ambivalence demonstrated by health care providers and families will discuss these concepts in relation to brain death, from the stages of hospitalization, through the period prior to the assertion of brain death, ending with brain death, and its perspective as a liminal situation.Finally, we conclude that nursing practices during the care of the "brain dead" patient, and toward the patient's family, should convey an unequivocal message. That is, brain death describes irreversible cessation of all brain function, and therefore, the patient becomes a dead body and can be treated as a potential organ donor.     

Components of the phosphatidylserine endoplasmic reticulum to plasma membrane transport mechanism as targets for KRAS inhibition in pancreatic cancer

KRAS is mutated in 90% of human pancreatic ductal adenocarcinomas (PDACs). To function, KRAS must localize to the plasma membrane (PM) via a C-terminal membrane anchor that specifically engages phosphatidylserine (PtdSer). This anchor-binding specificity renders KRAS–PM localization and signaling capacity critically dependent on PM PtdSer content. We now show that the PtdSer lipid transport proteins, ORP5 and ORP8, which are essential for maintaining PM PtdSer levels and hence KRAS PM localization, are required for KRAS oncogenesis. Knockdown of either protein, separately or simultaneously, abrogated growth of KRAS-mutant but not KRAS–wild-type pancreatic cancer cell xenografts. ORP5 or ORP8 knockout also abrogated tumor growth in an immune-competent orthotopic pancreatic cancer mouse model. Analysis of human datasets revealed that all components of this PtdSer transport mechanism, including the PM-localized EFR3A-PI4KIIIα complex that generates phosphatidylinositol-4-phosphate (PI4P), and endoplasmic reticulum (ER)–localized SAC1 phosphatase that hydrolyzes counter transported PI4P, are significantly up-regulated in pancreatic tumors compared to normal tissue. Taken together, these results support targeting PI4KIIIα in KRAS-mutant cancers to deplete the PM-to-ER PI4P gradient, reducing PM PtdSer content. We therefore repurposed the US Food and Drug Administration–approved hepatitis C antiviral agent, simeprevir, as a PI4KIIIα inhibitor In a PDAC setting. Simeprevir potently mislocalized KRAS from the PM, reduced the clonogenic potential of pancreatic cancer cell lines in vitro, and abrogated the growth of KRAS-dependent tumors in vivo with enhanced efficacy when combined with MAPK and PI3K inhibitors. We conclude that the cellular ER-to-PM PtdSer transport mechanism is essential for KRAS PM localization and oncogenesis and is accessible to therapeutic intervention.

RAS proteins are small GTPases that switch between active GTP-bound and inactive GDP-bound states, regulating cell proliferation, differentiation, and apoptosis. RAS is regulated by guanine nucleotide exchange factors that promote GDP–GTP exchange, thereby activating RAS, and GTPase-activating proteins (GAPs), which stimulate intrinsic RAS GTPase activity to return it to its inactive state. Approximately 20% of human cancers express oncogenic RAS with mutations at residues 12, 13, or 61 (1), which prevent RASGAPs from stimulating GTP hydrolysis, rendering RAS constitutively active. The RAS isoforms, HRAS, NRAS, KRAS4A, and KRAS4B (hereafter referred to as KRAS), have near-identical G-domains, which are implicated in guanine nucleotide binding and effector interaction. However, they have different C termini and membrane anchors, which contribute to their differential signaling outputs (2). KRAS is the most-frequently mutated isoform in cancer and hence represents the major clinical concern, especially in pancreatic, colon, and non–small cell lung cancers (NSCLCs) in which mutant KRAS is expressed in ∼90%, ∼50%, and ∼25% of cases, respectively (3).RAS proteins must localize to the plasma membrane (PM) and organize into nanoclusters for biological activity (4–8), whereby RAS.GTP recruits its effectors to PM nanoclusters, leading to downstream pathway activation. KRAS interacts with the PM via its C-terminal membrane anchor that comprises a farnesyl-cysteine-methyl-ester and a polybasic domain (PBD) of six contiguous lysines (9–11). Together, the KRAS PBD sequence and prenyl group define a combinatorial code for lipid binding, resulting in a membrane anchor that specifically interacts with asymmetric species of phosphatidylserine (PtdSer) that contain one saturated and one desaturated acyl chain (8, 12–14). Since PtdSer binding specificity is hardwired into its anchor structure, KRAS–PM interactions are PtdSer dependent. KRAS that partitions into the cytosol following endocytosis is captured by PDEδ, which, upon interacting with ARL2, is released to the recycling endosome (RE) for forward transport back to the PM (15). Capture of KRAS by the RE is again PtdSer dependent; therefore, abrogating PtdSer delivery to the PM will reduce PM and RE PtdSer content, abrogating both KRAS PM binding and KRAS recycling back to the PM. In sum, KRAS–PM localization, nanoclustering, and signaling capacity are all exquisitely dependent on PM PtdSer levels.Previous attempts at preventing KRAS–PM localization to inhibit its function include the development of farnesyltransferase inhibitors (FTIs), which inhibit the first posttranslational processing step that generates the KRAS membrane anchor. FTIs were clinically unsuccessful since KRAS can alternatively be geranylgeranylated by geranylgeranyl transferase1 when cells are treated with FTIs, allowing for continued PM localization (2, 16, 17). We recently leveraged the dependence of KRAS on PM PtdSer to inhibit KRAS signaling by targeting the cellular machinery that actively maintains PM PtdSer levels (18). Genetic knockdown (KD) of ORP5 or ORP8, two lipid transporters that function at endoplasmic reticulum (ER)–PM membrane contact sites to transport PtdSer to the PM (Fig. 1), mislocalized KRAS from the PM and reduced nanoclustering of any remaining KRAS. Consequently, ORP5/8 KD decreased proliferation and anchorage-independent growth of multiple KRAS-dependent pancreatic cancer cell lines. In this study, we examine the effects of ORP5/8 genetic KD and knockout (KO) on tumor growth in vivo and provide compelling evidence that these proteins are essential for tumor maintenance in KRAS-dependent pancreatic cancer. ORP5/8 function by exchanging phosphoinositide-4-phosphate (PI4P) synthesized on the PM by PI4KIIIα for PtdSer synthesized in the ER (19, 20). We demonstrate both in vitro and in vivo that PI4KIIIα inhibitors can potently inhibit oncogenic KRAS function. One such inhibitor is simeprevir, a US Food and Drug Administration (FDA)–approved antiviral agent used for the treatment of hepatitis C, that may have potential for repurposing as a therapeutic for mutant KRAS-driven cancers.Open in a separate windowFig. 1.ORP5 and ORP8 transport PtdSer to the PM. ORP5 and ORP8 exchange ER PtdSer with PM PI4P. This is driven by a PI4P concentration gradient whereby PM PI4P levels are kept high by PI4KIIIα and low at the ER by SAC1P, which hydrolyzes PI4P. ORP, oxysterol-binding protein-related protein; PI4KIIIα, class III PI4 kinase alpha; and SAC1P, SAC1-like phosphatidylinositide phosphatase.     

Preinvasive and invasive cervical cancer: an ex vivo proton magic angle spinning magnetic resonance spectroscopy study

The aim of this study was to obtain (1)H MR spectra using magic angle spinning (MAS) techniques from punch biopsies (<20 mg) of preinvasive and invasive cervical disease and to correlate the spectral profiles with sample classification on the basis of histopathology. Tissue samples were obtained at colposcopic examination, during local treatment of cervical intraepithelial neoplasia (CIN) or at hysterectomy. (1)H MAS MRS was performed at 25 degrees C while spinning the sample at 4.5 kHz. After measurement, the tissue was immersed in formalin and the pathology determined. Histological examination after (1)H MAS MRS defined 27 samples with squamous cell carcinoma (SCC), 12 with CIN and 39 with only normal tissue. The standardized integrals of the lipid, choline and creatine regions of the spectra were significantly higher in SCC than in normal or CIN tissue. There was no obvious difference in the standardized integral of the region 4.15-3.5 ppm. The acyl fatty acid side-chain length was longer or less unsaturated in SCC than in normal tissue. Normal tissue from patients with SCC showed significantly higher triglycerides than normal tissue from patients with benign uterine disease but significantly lower triglycerides than SCC tissue. (1)H MAS MRS of the uterine cervix ex vivo may be used to differentiate non-invasive from invasive cervical lesions, increase interpretation of in vivo MRS and provide insights into tumor biology.     

Detection of human bocavirus in hospitalised children

Aim:   The objectives of this study are to assess the frequency of human bocavirus (HBoV) infection in hospitalised children and to study the clinical symptoms associated with the detection of HBoV.
Methods:   Two groups of hospitalised children were included in this study: group 1 consisted of 1946 children hospitalised from 1st September 2004 to 30th May 2005, and group 2 consisted of 448 children hospitalised from 1st November 2003 to 30th March 2004. The respiratory specimens were tested by polymerase chain reaction.
Results:   In the first group, HBoV was detected by polymerise chain reaction in 11/828 (1.3%) of nasal specimens that tested negative for other respiratory viruses. One child tested positive for HBoV in both a nasal aspirate and stool sample. In the second group, nasal specimens were tested for all respiratory viruses, including HBoV. The presence of HBoV infection was detected in seven children (1.6%). Detection of a mixed viral population was observed in four of these children. The main symptoms in children infected with HBoV were rhinitis (50%), cough (45%), dyspnoea (28%), wheezing (28%), fever (23%) and diarrhoea (22%). The final clinical diagnoses were bronchiolitis (seven children), rhinopharyngitis (five children), the exacerbation of asthma (two children) and pneumonia (one child). Moreover, four children have associated gastroenteritis.
Conclusion:   These results contribute to the interest in the HBoV detection in children. HBoV detection in hospitalised children with or without any other respiratory virus detection was essentially associated with lower respiratory tract infection and in a lower score with upper respiratory tract infection and gastroenteritis.     

Fine mapping of a region on chromosome 8p gives evidence for a QTL contributing to individual differences in an anxiety-related personality trait: TPQ harm avoidance.

The chromosome 8p region is of interest in human behavioral genetics since it harbors a susceptibility region not only for schizophrenia but also for anxiety-related personality traits such as harm avoidance and neuroticism. Towards verifying our preliminary linkage finding of a QTL for TPQ harm avoidance at chromosome 8p, we have now genotyped altogether 24 micro-satellite markers in 377 families. Using three methods (maximum likelihood binomial or MLB, MERLIN, and an associated one parameter model), we observed significant results (P values from 0.002 to 0.0004) for linkage to harm avoidance in this region. A peak multipoint LOD score of 2.76 (P value 0.0002) was obtained with the MLB method. The region-wide empirical P value was 0.002 [0.001-0.0046]. Although, the peak position varied somewhat according to the method (D8S1048 for MLB, D8S1463 for the two other methods), for three methods D8S1810 ( approximately 60 cM) is within 1-2 cM of the peak for harm avoidance. This marker is of particular interest since it is proximate (<0.5 cM) of the core haplotype that in several recent studies show significant association with schizophrenia near neuroregulin 1. Although association studies with microsatellite markers need to be interpreted cautiously, using the Haplotype Trend Regression test one marker, D8S499 ( approximately 60 cM), showed an empirical P value of 2 x 10(-5) for allele 3, which confers a decreased harm avoidance score. Altogether, the current linkage and association results suggest the possibility that the same locus near the neuroregulin 1 gene on chromosome 8p confers risk for both an anxiety-related personality trait as well as schizophrenia. We hypothesize that this common genetic factor may contribute to emotional liability during early development, which constitutes a predisposing factor for major psychosis.