Specific conversion of s4 U to U in Escherichia coli tRNA by iodate oxidation.

The minor nucleoside 4-thiouridine in Escherichia coli tRNA is transformed selectively to uridine by iodate oxidation at acidic pH. The four major nucleotides were found to be inert under these conditions. The iodate oxidation appears to be more specific than the previous conversion methods reported, and has the advantage that it does not affect the chargeability of most tRNA.     

Simultaneous tissue profiling of eicosanoid and endocannabinoid lipid families in a rat model of osteoarthritis

We describe a novel LC method for the simultaneous and quantitative profiling of 43 oxylipins including eicosanoids, endocannabinoids, and structurally related bioactive lipids with modified acyl groups. The LC-MS/MS method uses switching at a defined time between negative and positive electrospray ionization modes to achieve optimal detection sensitivity for all the lipids. The validated method is linear over a range of 0.01–5 nmol/g (0.1–50 nmol/g for 2-arachidonoyl glycerol) with intra- and interday precision and accuracy between 1.38 and 26.76% and 85.22 and 114.3%, respectively. The method successfully quantified bioactive lipids in different tissue types in the rat, including spinal cord, dorsal root ganglia (DRGs), knee joint, brain, and plasma. Distinct regional differences in the pattern of lipid measured between tissue types were observed using principle component analysis. The method was applied to analyze tissue samples from an established preclinical rat model of osteoarthritis (OA) pain and showed that levels of 12-hydroxyeicosatetraenoic acid were significantly increased in the OA rat knee joint compared with controls, and that 15-hydroxyeicosatetraenoic acid was significantly increased in the DRGs in the model of OA compared with controls. The developed LC-MS/MS method has the potential to provide detailed pathway profiling in tissues and biofluids where the disruption of bioactive oxylipins may be involved in disease states.     

The mushroom ribosome-inactivating protein lyophyllin exerts deleterious effects on mouse embryonic development in vitro

Earlier investigations disclose that some plant ribosome-inactivating proteins (RIPs) adversely affect mouse embryonic development. In the present study, a mushroom RIP, namely lyophyllin from Lyophyllum shimeji, was isolated, partially sequenced, and its translation inhibitory activity determined. Its teratogenicity was studied by using a technique entailing microinjection and postimplantation whole-embryo culture. It was found that embryonic abnormalities during the period of organogenesis from E8.5 to E9.5 were induced by lyophyllin at a concentration as low as 50 μg/ml, and when the lyophyllin concentration was raised, the number of abnormal embryos increased, the final somite number decreased, and the abnormalities increased in severity. The affected embryonic structures included the cranial neural tube, forelimb buds, branchial arches, and body axis, while optic and otic placodes were more resistant. Lyophyllin at a concentration higher than 500 μg/ml also induced forebrain blisters within the cranial mesenchyme. When the abnormal embryos were examined histologically, an increase of cell death was found to be associated with abnormal structures, indicating that cell death may be one of the underlying causes of teratogenicity of the mushroom RIP. This constitutes the first report on the teratogenicity of a mushroom RIP.     

Technologies for integrating biological data

The process of building a new database relevant to some field of study in biomedicine involves transforming, integrating and cleansing multiple data sources, as well as adding new material and annotations. This paper reviews some of the requirements of a general solution to this data integration problem. Several representative technologies and approaches to data integration in biomedicine are surveyed. Then some interesting features that separate the more general data integration technologies from the more specialised ones are highlighted.     

A differential medium for the identification of races 1 and 4 of Fusarium oxysporum f.sp. cubense

Three distinctive colony types were produced when Fusarium oxysporum f.sp. cubense (Foc ) races 1 and 4 were cultured on a defined basal medium containing an appropriate carbon source and bromothymol blue as a pH indicator. These distinctive cultural characteristics have been used as a specific and reliable method for the differentiation of races 1 and 4 of Foc from other species of Fusarium.     

Detection by high pressure infrared spectrometry of hydrogen-bonding between water and triacetyl glycerol

The barotropic behavior of neat and aqueous 1,2,3-triacetyl glycerol was investigated by FT-IR spectroscopy over the pressure range 0.001 to 35 kbar. The infrared spectrum in the presence of water shows bands characteristic of hydrogen bonded carbonyl groups. An increase in hydrostatic pressure leads to a strengthening of the intermolecular hydrogen bond between water and the lipid ester C = O groups. The pressure-induced formation of ice VI at 9 kbar does not affect this hydrogen bond, however, the formation, at 20 kbar, of ice VII in which the water/water hydrogen bonds are stronger than the lipid C = O/water hydrogen bonds, frees the lipid carbonyl groups from the hydrogen-bonding to water.     

Novel Biomarkers for Non-functioning Invasive Pituitary Adenomas were Identified by Using Analysis of microRNAs Expression Profile

The microRNAs (miRNAs) are involved in multiple pathological processes among various types of tumors. However, the functions of miRNAs in benign brain tumors are largely unexplored. In order to explore the pathogenesis of the invasiveness in non-functional pituitary adenoma (NFPA), the miRNAs expression profile was analyzed between invasive and non-invasive non-functional pituitary adenoma by miRNAs microarray. Six most significant differentially expressed miRNAs were identified including four upregulated miRNAs hsa-miR-181b-5p, hsa-miR-181d, hsa-miR-191-3p, and hsa-miR-598 and two downregulated miRNAs hsa-miR-3676-5p and hsa-miR-383. The functions and corresponding signaling pathways of differentially expressed miRNAs were investigated by bioinformatics techniques, including Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis. The result of GO analysis indicates regulation of voltage-gated potassium channel activity, positive regulation of sodium ion transport, positive regulation of GTPase activity, negative regulation of Notch signaling pathway, etc. KEGG pathway reveals a series of biological processes, including prolactin signaling pathway, endocrine and other factor-regulated calcium reabsorption, fatty acid metabolism, neuroactive ligand-receptor interaction, etc. The miRNAs hsa-miR-181a-5p was verified by quantitative real-time PCR, and the expression level was in accordance with the microarray result. Our result can provide the evidence on featured miRNAs which play a prominent role in pituitary adenoma as effective biomarkers and therapeutic targets in the future.     

Role of ICAM-1 in chronic hepatic allograft rejection in the rat

The pathogenesis of hepatic allograft rejection remains unclear. We aimed to clarify the early role of intercellular adhesion molecule-1 (ICAM-1)-mediated cell recruitment in chronic hepatic rejection. Liver transplantation was performed from Lewis to Lewis rats (isograft controls) and from Lewis to Brown Norway rats (allograft rejection group). The allografted rats were treated with either ICAM-1 antisense oligonucleotides (10 mg. kg(-1). day(-1) x 6 days ip) or a control preparation (either ICAM-1 missense oligonucleotide or normal saline). Hepatic leukocyte recruitment in vivo was studied on day 6 by using intravital microscopy. Liver histology, biochemistry, and survival rates were also examined. Leukocyte adhesion in terminal hepatic venules was significantly increased in the rejection group compared with isograft controls. Antisense ICAM-1 in the allografted group effectively reduced leukocyte adhesion. Histology and liver chemistry were less deranged in the antisense-treated groups compared with control-treated allografted rats. In the allograft groups, survival was significantly prolonged in the antisense-treated rats (42.3 +/- 1.2 days) compared with the controls (25.2 +/- 2.7 days). These results showed that early leukocyte recruitment in the hepatic microvasculature of rejecting allografts is ICAM-1 dependent and suggest that impacting on early cell recruitment can significantly ameliorate chronic rejection.     

Age-dependent core temperature responses of conscious rabbits to acute hypoxemia.

Experiments were carried out on chronically instrumented newborn and older rabbits to characterize their core temperature (T(c)) responses to acute hypoxemia and to differentiate "forced" vs. "regulated" thermoregulatory responses. Three age ranges of kits were studied: 4-6, 9-11, and 28-30 days of age. During an experiment, T(c), selected ambient temperature (T(a)), and oxygen consumption were measured from kits studied in a thermocline during a control period of normoxemia, an experimental period of normoxemia or hypoxemia (fraction of inspired oxygen 0.10), and a recovery period of normoxemia. We reasoned that no change or a decrease in T(a) while T(c) decreased during hypoxemia would indicate a regulated thermoregulatory response, whereas an increase in T(a) while T(c) decreased during hypoxemia would indicate a forced thermoregulatory response. T(c) decreased during acute hypoxemia in the older kits but not in the 4- to 6-day-old kits; the decrease in T(c) was accentuated on postnatal days 28-30 compared with postnatal days 9-11. T(a) decreased or stayed the same during exposure to acute hypoxemia. Our data provide evidence that postnatal maturation influences the T(c) response of rabbits to acute hypoxemia and that the decrease in T(c) during hypoxemia in the older kits results from a regulated thermoregulatory response.     

Regulatory BC1 RNA and the fragile X mental retardation protein: convergent functionality in brain

Background

BC RNAs and the fragile X mental retardation protein (FMRP) are translational repressors that have been implicated in the control of local protein synthesis at the synapse. Work with BC1 and Fmr1 animal models has revealed that phenotypical consequences resulting from the absence of either BC1 RNA or FMRP are remarkably similar. To establish functional interactions between BC1 RNA and FMRP is important for our understanding of how local protein synthesis regulates neuronal excitability.

Methodology/Principal Findings

We generated BC1−/− Fmr1−/− double knockout (dKO) mice. We examined such animals, lacking both BC1 RNA and FMRP, in comparison with single knockout (sKO) animals lacking either one repressor. Analysis of neural phenotypical output revealed that at least three attributes of brain functionality are subject to control by both BC1 RNA and FMRP: neuronal network excitability, epileptogenesis, and place learning. The severity of CA3 pyramidal cell hyperexcitability was significantly higher in BC1−/− Fmr1−/− dKO preparations than in the respective sKO preparations, as was seizure susceptibility of BC1−/− Fmr1−/− dKO animals in response to auditory stimulation. In place learning, BC1−/− Fmr1−/− dKO animals were severely impaired, in contrast to BC1−/− or Fmr1−/− sKO animals which exhibited only mild deficits.

Conclusions/Significance

Our data indicate that BC1 RNA and FMRP operate in sequential-independent fashion. They suggest that the molecular interplay between two translational repressors directly impacts brain functionality.