The Aminoacyl-tRNA Synthetase and tRNA Expression Levels Are Deregulated in Cancer and Correlate Independently with Patient Survival

Aminoacyl-tRNA synthetases (ARSs) are essential enzymes that load amino acids to their cognate tRNA molecules. The expression of certain ARSs and tRNAs has been shown to be deregulated in cancer, presumably to accommodate elevated protein synthesis requirements. In this work, the expression of cytoplasmic ARSs and tRNAs in ten TCGA cancers has been systematically examined. ARSs were found to be mostly upregulated in tumours and their upregulation often correlated with worse patient survival. tRNAs were found to be either upregulated or downregulated in tumours and their expression sometimes correlated to worse survival outcomes. However, although the expression of most ARSs and tRNAs was deregulated in tumours when compared to healthy adjacent tissues, only in a few cases, and independently, did it correlate to patient survival. These data point to the general uncoupling of concomitant ARS and tRNA expression deregulation and patient survival, highlighting the different ARS and tRNA requirements in cancers.     

Life history, aspects of reproductive biology and production of Corophium orientale (Crustacea: Amphipoda) in Monolimni lagoon (Evros Delta, North Aegean Sea)

Monthly samples of Corophium orientale were collected during February 1998–February 1999 in both parts of Monolimni lagoon (0.3 < Sal. < 6 psu, 2 < Temp. < 28.5 °C). Corophium orientaleshowed a semiannual life cycle. In the southern part, breeding occurred from early spring to mid autumn having three peaks, in early spring, early summer and early autumn, and three cohorts were produced, a spring cohort, a summer cohort and an overwintering one. In the shallower innermost northern part of Monolimni lagoon, breeding peaked in mid-spring and, also, in early autumn, and two discrete cohorts, a spring and an overwintering one, were produced. A lack of large individuals, attributed to a temporary size – selective predation by migrating shorebirds, was observed during summer. That lack possibly contributed to the hiatus in reproduction. Photoperiod seemed to be a more important cue than temperature in the initiation of the reproductive cycle, while extremely low salinities (<1 psu) did not deter breeding. Females attained maturity at a smaller size in late spring and, especially, in summer than in early spring at lower temperatures. Brood size was a function of females body size. Females, matured during summer at high temperatures, showed the lowest brood size, body length ratio. Mean brood size was small (12–13 early embryos) and embryo loss during development high (54%), possibly due to a negative effect of low salinities. A 1:1 sex ratio existed in the small body length classes, but females preponderated in the large ones. The spring cohort in the southern part, which developed at moderate temperatures, showed the highest growth rate (40 m day^–1). Secondary production of C. orientalecalculated by Hyness method gave a mean annual density of 4562.5 and 9327.6 ind. m^–2, a mean annual crop (B) of 1.03 and 2.67 g DW m^–2, an annual production (P) of 6.91 and 22.54 g DW m^–2 and a P/B ratio of 6.7 and 8.4 in the northern and southern part of the lagoon, respectively.     

Matrix proteoglycans are markedly affected in advanced laryngeal squamous cell carcinoma

Proteoglycans (PGs) are implicated in the growth and progression of malignant tumors. In this study, we examined the concentration and localization of PGs in advanced (stage IV) laryngeal squamous cell carcinoma (LSCC) and compared with human normal larynx (HNL). LSCC and HNL sections were examined immunohistochemically with a panel of antibodies, and tissues extracts were analyzed by biochemical methods including immunoblotting and high performance liquid chromatography (HPLC). The results demonstrated significant destruction of cartilage in LSCC, which was followed by marked decrease of aggrecan and link protein. In contrast to the loss of aggrecan in LSCC, accumulation of versican and decorin was observed in the tumor-associated stroma. Biochemical analyses indicated that aggrecan, versican, decorin and biglycan comprise the vast majority of total PGs in both healthy and cancerous tissue. In LSCC the absolute amounts of KS/CS/DS-containing PGs were dramatically decreased about 18-fold in comparison to HNL. This decrease is due to the loss of aggrecan. Disaccharide analysis of CS/DSPGs from LSCC showed a significant reduction of 6-sulfated Delta-disaccharides (Deltadi-6S) with a parallel increase of 4-sulfated Delta-disaccharides (Deltadi-4S) as compared to HNL. The obtained data clearly demonstrate that tumor progression is closely related to specific alteration of matrix PGs in LSCC. The altered composition of PGs in cartilage, as well as in tumor-associated stroma, is crucial for the biological behaviour of cancer cells in the diseased tissue.     

Primary effusion lymphoma. A case report

BACKGROUND: Primary effusion lymphoma (PEL) is a rare type of lymphoma that presents as an effusion, seldom with evidence of a solid neoplasm elsewhere; thus, cytology is the basic diagnostic method. It usually occurs in HIV-positive males with a history of Kaposi's sarcoma (KS), and DNA sequences of human herpesvirus 8 (HHV-8) are detected by molecular analysis. The distinct morphologic, immunophenotypic, molecular and clinical characteristics render this neoplasm a new pathologic entity. CASE: A 57-year-old, HIV-positive man presented to the hospital with ascites and absence of neoplasm on radiologic investigation. Cytologic evaluation of the ascitic fluid revealed the presence of highly atypical, pleomorphic lymphoid cells. Immunocytochemistry of the lymphoma cells was positive for CD45 (leukocyte common antigen), CD30 and epithelial membrane antigen antigens and negative for panB, panT and cytokeratin antigens. DNA sequences of HHV-8 were identified by polymerase chain reaction (PCR), and DNA ploidy analysis showed aneuploidy. The patient died 5 months after the diagnosis. CONCLUSION: Conventional and ThinPrep (Cytyc Corp., Boxborough, Massachusetts, U.S.A.) cytology, in combination with immunocytochemistry and PCR for HHV-8 DNA sequences, can lead to an accurate diagnosis of PEL. DNA ploidy analysis confirms the aggressive nature of this neoplasm.     

Pregnancy associated plasma protein-A as a prognostic biomarker of all-cause mortality and cardiovascular events in patients presenting with chest pain: a systematic review

Aim: Novel biomarkers have been proposed for identification of patients at greater risk of future adverse events among those presenting with chest pain. In this review, we aim to elucidate the ability of pregnancy associated plasma protein-A (PAPP-A) to predict mortality and other cardiovascular events in this patient population.

Methods: A literature search of the electronic databases Medline, Scopus, Cochrane Library and ClinicalTrials.gov was performed in order to identify studies investigating the utility of PAPP-A to predict mortality and adverse cardiovascular events in patients with chest pain.

Results: Eight studies met our inclusion criteria. Five of these studies pertained to patients with confirmed ischemic chest pain, while the rest included patients presenting with chest pain possibly due to acute coronary syndrome, irrespectively of the underlying cause. Although the results for long-term events were inconclusive in both groups of patients, higher PAPP-A concentrations were found to be a significant predictor of short-term adverse events in patients with confirmed ischemic chest pain.

Conclusions: PAPP-A appears to be a potentially useful biomarker for short-term risk stratification of patients presenting with chest pain of ischemic origin. However, there is an eminent need for more standardized clinical studies investigating the prognostic value of this biomarker.     

Rapid stimulation of glucose transport by mitochondrial uncoupling depends in part on cytosolic Ca2+ and cPKC

2,4-Dinitrophenol (DNP) uncouples the mitochondrial oxidativechain from ATP production, preventing oxidative metabolism. Theconsequent increase in energy demand is, however, contested by cellsincreasing glucose uptake to produce ATP via glycolysis. In L6 skeletalmuscle cells, DNP rapidly doubles glucose transport, reminiscent of theeffect of insulin. However, glucose transport stimulation by DNP doesnot require insulin receptor substrate-1 phosphorylation and iswortmannin insensitive. We report here that, unlike insulin, DNP doesnot activate phosphatidylinositol 3-kinase, protein kinaseB/Akt, or p70 S6 kinase. However, chelation of intra- andextracellular Ca²⁺ with1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraaceticacid-AM in conjunction with EGTA inhibited DNP-stimulated glucoseuptake by 78.9 ± 3.5%. BecauseCa²⁺-sensitive, conventionalprotein kinase C (cPKC) can activate glucose transport in L6 musclecells, we examined whether cPKC may be translocated andactivated in response to DNP in L6 myotubes. Acute DNP treatment led totranslocation of cPKCs to plasma membrane. cPKC immunoprecipitated fromplasma membranes exhibited a twofold increase in kinase activity inresponse to DNP. Overnight treatment with 4-phorbol 12-myristate13-acetate downregulated cPKC isoforms , , and  and partiallyinhibited (45.0 ± 3.6%) DNP- but not insulin-stimulatedglucose uptake. Consistent with this, the PKC inhibitorbisindolylmaleimide I blocked PKC enzyme activity at theplasma membrane (100%) and inhibited DNP-stimulated2-[³H]deoxyglucoseuptake (61.2 ± 2.4%) with no effect on the stimulation of glucose transport by insulin. Finally, the selective PKC- inhibitorLY-379196 partially inhibited DNP effects on glucose uptake (66.7 ± 1.6%). The results suggest interfering with mitochondrial ATPproduction acts on a signal transduction pathway independent from thatof insulin and partly mediated byCa²⁺ and cPKCs, of which PKC-likely plays a significant role.

     

Atomic‐Layer‐Deposited Aluminum and Zirconium Oxides for Surface Passivation of TiO2 in High‐Efficiency Organic Photovoltaics

The reduction in electronic recombination losses by the passivation of surfaces is a key factor enabling high‐efficiency solar cells. Here a strategy to passivate surface trap states of TiO₂ films used as cathode interlayers in organic photovoltaics (OPVs) through applying alumina (Al₂O₃) or zirconia (ZrO₂) insulating nanolayers by thermal atomic layer deposition (ALD) is investigated. The results suggest that the surface traps in TiO₂ are oxygen vacancies, which cause undesirable recombination and high electron extraction barrier, reducing the open‐circuit voltage and the short‐circuit current of the complete OPV device. It is found that the ALD metal oxides enable excellent passivation of the TiO₂ surface followed by a downward shift of the conduction band minimum. OPV devices based on different photoactive layers and using the passivated TiO₂ electron extraction layers exhibit a significant enhancement of more than 30% in their power conversion efficiencies compared to their reference devices without the insulating metal oxide nanolayers. This is a result of significant suppression of charge recombination and enhanced electron extraction rates at the TiO₂/ALD metal oxide/organic interface.     

Design and validation of a high-throughput assay to detect codon 146 polymorphisms in the caprine prion protein gene

In sheep, scrapie susceptibility is so strongly associated with single nucleotide polymorphisms (SNPs) in the gene encoding the prion protein (PrP) that this linkage constitutes the basis for selective breeding strategies directed toward controlling the disease. For goats, in contrast, the association between scrapie susceptibility/resistance and variations in the PrP gene is far weaker, with only a few identified SNPs showing an influence on scrapie susceptibility. A recent survey of PrP genotypes in Cypriot goats, however, revealed the existence of a robust association between polymorphisms at codon 146 of the caprine PrP gene and resistance/susceptibility to natural scrapie. Here we describe here a high-throughput assay, based on homogeneous MassExtend technology coupled with mass spectrometry, for genotyping codon 146 of the caprine PrP gene. Our results demonstrate that this assay exhibits high accuracy, reproducibility, and repeatability, thereby making it suitable for large-scale SNP genotyping, as required for scrapie surveillance programs.     

Comparative analysis of four <Emphasis Type="Italic">β</Emphasis>-galactosidases from <Emphasis Type="Italic">Bifidobacterium bifidum</Emphasis> NCIMB41171: purification and biochemical characterisation

Four different β-galactosidases (previously named BbgI, BbgII, BbgIII and BbgIV) from Bifidobacterium bifidum NCIMB41171 were overexpressed in Escherichia coli, purified to homogeneity and their biochemical properties and substrate preferences comparatively analysed. BbgI was forming a hexameric protein complex of 875 kDa, whereas BbgII, BbgIII and BbgIV were dimers with native molecular masses of 178, 351 and 248 kDa, respectively. BbgII was the only enzyme that preferred acidic conditions for optimal activity (pH 5.4–5.8), whereas the other three exhibited optima in more neutral pH ranges (pH 6.4–6.8). Na⁺ and/or K⁺ ions were prerequisite for BbgI and BbgIV activity in Bis–Tris-buffered solutions, whereas Mg⁺⁺ was strongly activating them in phosphate-buffered solutions. BbgII and BbgIII were slightly influenced from the presence or absence of cations, with Mg⁺⁺, Mn⁺⁺ and Ca⁺⁺ ions exerting the most positive effect. Determination of the specificity constants (k _cat/K _m) clearly indicated that BbgI (6.11 × 10⁴ s⁻¹ M⁻¹), BbgIII (2.36 × 10⁴ s⁻¹ M⁻¹) and especially BbgIV (4.01 × 10⁵ s⁻¹ M⁻¹) are highly specialised in the hydrolysis of lactose, whereas BbgII is more specific for β-d-(1→6) galactobiose (5.59 × 10⁴ s⁻¹ M⁻¹) than lactose (1.48 × 10³ s⁻¹ M⁻¹). Activity measurements towards other substrates (e.g. β-d-(1→6) galactobiose, β-d-(1→4) galactobiose, β-d-(1→4) galactosyllactose, N-acetyllactosamine, etc.) indicated that the β-galactosidases were complementary to each other by hydrolysing different substrates and thus contributing in a different way to the bacterial physiology.     

Parathyroid hormone-related protein is reduced in severe chronic heart failure

In the cardiovascular system, parathyroid hormone-related peptide (PTHrP) is expressed in various cells such as cardiac vascular smooth muscle cells, coronary endothelial cells and cardiomyocytes and acts as an autocrine/paracrine substance. We compared PTHrP levels in 35 consecutive patients with severe CHF (33 male, mean age 66.2 +/- 8.9 years) with 26 normal controls (24 male, mean age 63.1 +/- 8.6 years). PTHrP levels were reduced in severe CHF patients (11.10 +/- 1.37 fmol/ml) compared with the controls (20.62 +/- 3.30 fmol/ml, p = 0.005). PTHrP values decreased as a function of New York Heart Association classification. These results suggest that PTHrP levels decrease in proportion to the severity of heart failure and could potentially be used to monitor progression of disease non-invasively.