MicroRNA expression pattern in different stages of nonalcoholic fatty liver disease

BACKGROUND/AIMS

To explore the unique microRNA expression pattern of nonalcoholic fatty liver disease in a rat model, and search for targets of certain dysregulated microRNAs.

METHODS

Microarray and stem-loop RT-PCR were utilized to detect dysregulated microRNAs in a rat model. Significance Analysis of Microarray, Prediction Analysis of Microarray and clustering analysis were implemented to calculate significantly aberrantly expressed microRNAs. TargetScan, miRanda and PicTar were jointly used to predict targets of microRNAs.

RESULTS

Confirmed by Significance Analysis of Microarray and predicted by Prediction Analysis of Microarray, portfolios of 27 and 21 microRNAs were selected as an accurate molecular signature in distinguishing steatosis and steatohepatitis from normal rat liver. Besides, a panel of microRNA-target pairs that may be involved in lipid and glucose metabolism and inflammation process was delineated.

CONCLUSION

This is by far the first report on the dysregulated microRNAs expression pattern in nonalcoholic fatty liver disease. The successful differentiation of steatosis and steatohepatitis from normal liver hints to the potential of using lists of dysregulated microRNAs for diagnosis, though many problems need to be solved. Besides, these data will guide further studies of the contribution of microRNAs to the pathogenesis of nonalcoholic fatty liver disease while disease-specific microRNAs might become potential targets for therapeutic intervention.

MicroRNA expression pattern in different stages of nonalcoholic fatty liver disease

BACKGROUND/AIMS

To explore the unique microRNA expression pattern of nonalcoholic fatty liver disease in a rat model, and search for targets of certain dysregulated microRNAs.

METHODS

Microarray and stem-loop RT-PCR were utilized to detect dysregulated microRNAs in a rat model. Significance Analysis of Microarray, Prediction Analysis of Microarray and clustering analysis were implemented to calculate significantly aberrantly expressed microRNAs. TargetScan, miRanda and PicTar were jointly used to predict targets of microRNAs.

RESULTS

Confirmed by Significance Analysis of Microarray and predicted by Prediction Analysis of Microarray, portfolios of 27 and 21 microRNAs were selected as an accurate molecular signature in distinguishing steatosis and steatohepatitis from normal rat liver. Besides, a panel of microRNA-target pairs that may be involved in lipid and glucose metabolism and inflammation process was delineated.

CONCLUSION

This is by far the first report on the dysregulated microRNAs expression pattern in nonalcoholic fatty liver disease. The successful differentiation of steatosis and steatohepatitis from normal liver hints to the potential of using lists of dysregulated microRNAs for diagnosis, though many problems need to be solved. Besides, these data will guide further studies of the contribution of microRNAs to the pathogenesis of nonalcoholic fatty liver disease while disease-specific microRNAs might become potential targets for therapeutic intervention.

Rap1b is critical for glycoprotein VI-mediated but not ADP receptor-mediated alpha2beta1 activation

BACKGROUND

The platelet alpha2beta1 integrin functions as both an adhesion and signaling receptor upon exposure to collagen. Recent studies have indicated that alpha2beta1 function can be activated via inside-out signaling, similar to the prototypical platelet integrin alphaIIbbeta3. However, signaling molecules that regulate alpha2beta1 activation in platelets are not well defined. A strong candidate molecule is the small GTPase Rap1b, the dominant platelet isoform of Rap1, which regulates alphaIIbbeta3 activation.

OBJECTIVES

We hypothesized that Rap1b positively regulates alpha2beta1 during agonist-induced platelet activation.

METHODS

To test whether Rap1b activates alpha2beta1 downstream of glycoprotein (GP)VI or other platelet receptors, we stimulated platelets purified from Rap1b-/- or wild-type mice with diverse agonists and measured alpha2beta1 activation using fluorescein isothiocyanate-labeled monomeric collagen. We also examined the role of Rap1b in outside-in signaling pathways by analyzing adhesion and spreading of Rap1b-/- or wild-type platelets on monomeric, immobilized collagen. Finally, we monitored the activation status of related Rap GTPases to detect changes in signaling pathways potentially associated with Rap1b-mediated events.

RESULTS

Rap1b-/- platelets displayed comparable ADP-induced or thrombin-induced alpha2beta1 activation as wild-type platelets, but reduced convulxin-dependent alpha2beta1 activation. Rap1b-/- platelets exhibited increased spreading on immobilized collagen but similar adhesion to immobilized collagen compared to wild-type platelets. Rap1b-/- platelets also showed Rap1a and Rap2 activation upon agonist stimulation, possibly revealing functional compensation among Rap family members.

CONCLUSIONS

Rap1b is required for maximal GPVI-induced but not ADP-induced activation of alpha2beta1 in murine platelets.

Molecular characterisation of outbreak-related strains of vancomycin-resistant Enterococcus faecium from an intensive care unit in Beijing, China

We investigated an outbreak of vancomycin-resistant Enterococcus faecium affecting 14 patients in a 20-bed intensive care unit (ICU) between September 2006 and August 2007 (incidence: 3.56 cases per 1000 ICU patient days). Eighteen isolates of vanA type E. faecium were analysed by pulsed field gel electrophoresis, which showed 14 types overall. Multilocus sequence typing (MLST) identified eight different sequence types (STs) (ST78, ST117, ST203, ST316, ST362, ST363, ST364 and ST365), including four new types (ST362, ST363, ST364 and ST365) and 17 strains belonged to clonal complexes CC17. Sixteen of these carried the esp gene. Eighteen Tn1546-like elements encoding vanA-type VRE were classified into three types (types I to III) and all of them contained both IS1216V and IS1542 insertions. Vancomycin resistance of 14 vanA type E. faecium isolates was transferred at a frequency of 1.3 x 10(-6) to 6.4 x 10(-5) between E. faecium strains during filter mating. Our findings indicate that conjugative dissemination of Tn1546-like elements among CC17 E. faecium occurred during the outbreak in this ICU.

Observation of two-source interference in the photoproduction reaction AuAu --> AuAurho0

In ultraperipheral relativistic heavy-ion collisions, a photon from the electromagnetic field of one nucleus can fluctuate to a quark-antiquark pair and scatter from the other nucleus, emerging as a rho{0}. The rho{0} production occurs in two well-separated (median impact parameters of 20 and 40 F for the cases considered here) nuclei, so the system forms a two-source interferometer. At low transverse momenta, the two amplitudes interfere destructively, suppressing rho{0} production. Since the rho{0} decays before the production amplitudes from the two sources can overlap, the two-pion system can only be described with an entangled nonlocal wave function, and is thus an example of the Einstein-Podolsky-Rosen paradox. We observe this suppression in 200 GeV per nucleon-pair gold-gold collisions. The interference is 87%+/-5%(stat.)+/-8%(syst.) of the expected level. This translates into a limit on decoherence due to wave function collapse or other factors of 23% at the 90% confidence level.

Force spectroscopy of hepatocytic extracellular matrix components

We present atomic force microscopy and force spectroscopy data of live hepatocytes (HEPG2/C3A liver cell line) grown in Eagle's Minimum Essential Medium, a complex solution of salts and amino acids commonly used for cell culture. Contact-mode imaging and force spectroscopy of this system allowed correlation of cell morphology and extracellular matrix (ECM) properties with substrate properties. Force spectroscopy analysis of cellular "footprints" indicated that the cells secrete large polymers (e.g., 3.5mum contour length and estimated MW 1000kDa) onto their substrate surface. Although definitive identification of the polymers has not yet been achieved, fluorescent-labeled antibody staining has specified the presence of ECM proteins such as collagen and laminin in the cellular footprints. The stretched polymers appear to be much larger than single molecules of known ECM components, such as collagen and heparan sulfate proteoglycan, thus suggesting that the cells create larger entangled, macromolecular structures from smaller components. There is strong evidence which suggests that the composition of the ECM is greatly influenced by the hydrophobicity of the substrate surface, with preferential production and/or adsorption of larger macromolecules on hydrophobic surfaces.

Stoma formation for fecal diversion: a plea for the laparoscopic approach

BACKGROUND

The aim of this study was to assess the results of laparoscopic stoma creation for fecal diversion, specifically focussing on feasibility, safety, and efficacy, as well as indications and techniques.

METHODS

Within a 10-year-period, all patients requiring laparoscopic stoma creation were evaluated prospectively. Patients' profiles and indications, procedures and results of operation, conversion, morbidity, mortality and short-term complications (stoma-related, laparoscopy-associated) were analyzed.

RESULTS

A total of 80 patients (39 males, 41 females) with a mean age of 55.5 years (range, 17-91) underwent laparoscopic stoma creation. Most common indications were unresectable advanced colorectal cancer (n=20), pelvic malignant cancer (e. g. ovarian, cervix and prostate cancer, n=16), and perianal Crohn's disease with complex fistulas (n=16). Only in one female patient with pelvic malignant disease was the procedure converted to laparotomy due to obesity (conversion rate, 1.3%). 79 patients underwent laparoscopic stoma creation (completion rate, 98.7%) including loop ileostomy (n=30), loop sigmoid colostomy (n=40) and end sigmoid colostomy (n=9). Postoperative complications were documented in 9 patients (overall morbidity rate, 11.4%), including 4 minor complications treated conservatively (2 cases of prolonged atonia and 1 case each of pneumonia and urinary tract infection) and 5 major complications requiring reoperation (reoperation rate, 6.3%): one parastomal abscess (drainage), one stoma retraction following rod dislocation (laparoscopic stoma recreation), small bowel obstruction in two patients (small bowel resection), one port-site hernia (fascial closure), and hemorrhage (managed by re-laparoscopy). Mean operation time was 74 min (range, 30-245 min). Mean blood loss volume was 80 ml (range, 30-400 ml). Patients were discharged from hospital after a mean of 10.3 days (range, 3-47). Within a 1-year follow-up, no further stoma complications were documented.

CONCLUSIONS

The advantages of laparoscopic stoma creation are low morbidity and reoperation rates, and no procedure-related mortality; our results suggest that laparoscopic stoma creation for fecal diversion is safe, feasible and effective. Therefore, at our institution, laparoscopic stoma creation is the method of choice for fecal diversion.

Cholinesterase inhibition and acetylcholine accumulation following intracerebral administration of paraoxon in rats

We evaluated the inhibition of striatal cholinesterase activity following intracerebral administration of paraoxon assaying activity either in tissue homogenates ex vivo or by substrate hydrolysis in situ. Artificial cerebrospinal fluid (aCSF) or paraoxon in aCSF was infused unilaterally (0.5 microl/min for 2 h) and ipsilateral and contralateral striata were harvested for ChE assay ex vivo. High paraoxon concentrations were needed to inhibit ipsilateral striatal cholinesterase activity (no inhibition at <0.1 mM; 27% at 0.1 mM; 79% at 1 mM paraoxon). With 3 mM paraoxon infusion, substantial ChE inhibition was also noted in contralateral striatum. ChE histochemistry generally confirmed these concentration- and side-dependent effects. Microdialysates collected for up to 4 h after paraoxon infusion inhibited ChE activity when added to striatal homogenate, suggesting prolonged efflux of paraoxon. Since paraoxon efflux could complicate acetylcholine analysis, we evaluated the effects of paraoxon (0, 0.03, 0.1, 1, 10 or 100 microM, 1.5 microl/min for 45 min) administered by reverse dialysis through a microdialysis probe. ChE activity was then monitored in situ by perfusing the colorimetric substrate acetylthiocholine through the same probe and measuring product (thiocholine) in dialysates. Concentration-dependent inhibition was noted but reached a plateau of about 70% at 1 microM and higher concentrations. Striatal acetylcholine was below the detection limit at all times with 0.1 microM paraoxon but was transiently elevated (0.5-1.5 h) with 10 microM paraoxon. In vivo paraoxon (0.4 mg/kg, sc) in adult rats elicited about 90% striatal ChE inhibition measured ex vivo, but only about 10% inhibition measured in situ. Histochemical analyses revealed intense AChE and glial fibrillary acidic protein staining near the cannula track, suggesting proliferation of inflammatory cells/glia. The findings suggest that ex vivo and in situ cholinesterase assays can provide very different views into enzyme-inhibitor interactions. Furthermore, the proliferation/migration of cells containing high amounts of cholinesterase just adjacent to a dialysis probe could affect the recovery and thus detection of extracellular acetylcholine in microdialysis studies.

Identification of proSAAS homologs in lower vertebrates: conservation of hydrophobic helices and convertase-inhibiting sequences

The prohormone convertases (PCs) 1/3 and 2 accomplish the major proteolytic cleavage events in neuroendocrine tissues; each of these convertases has a small associated binding protein that inhibits convertase action in the secretory pathway. The proSAAS protein binds to PC1/3, whereas the 7B2 protein binds to PC2. However, both convertase-binding proteins are more widely expressed than their cognate enzymes, suggesting that they may perform other functions as well. All known mammalian proSAASs are over 85% conserved; thus, identifying functionally important segments has been impossible. Here, we report the first identification of nonmammalian proSAAS molecules, from Xenopus and zebrafish (Danio rerio). Although these two proteins show an overall amino acid sequence identity of only 29 and 30% with mouse proSAAS, two 14-16 residue hydrophobic segments (predicted to form alpha-helices) and two, nine through 11 residue sequences containing basic convertase cleavage sites are highly conserved; therefore, these sequences may be of functional importance. Confidence that these nonmammalian molecules represent authentic proSAAS is supported by the finding that both inhibit mouse PC1/3 with nanomolar inhibition constants; human furin was not inhibited. In vitro, the two proteins were cleaved by PC2 and furin to three or more peptide products. Both zebrafish and Xenopus proSAAS exhibited neural and endocrine distributions, as assessed by in situ and PCR experiments, respectively. In summary, the identification of proSAAS molecules in lower vertebrates provides clues as to functional regions within this widely expressed neuroendocrine protein.

Effects of tracheal tube orientation on the success of intubation through an intubating laryngeal mask airway: study in Mallampati class 3 or 4 patients

BACKGROUND

We evaluated the effects of conventional tracheal tube orientation on success of intubation through an intubating laryngeal mask airway (ILMA) in Mallampati class 3 or 4 patients.

METHODS

Two hundred adults, ASA I-II, Mallampati class 3 or 4, undergoing elective surgery under general anaesthesia were enrolled. All the patients were randomly allocated to either normal or reverse group based on the orientation of the tracheal tube as it was initially inserted into the ILMA. Tracheal intubation was considered successful, if proper tracheal positioning was attained within three insertion attempts. chi(2) analysis was used to compare categorical variables.

RESULTS

Tracheal intubation through the ILMA was successful in 183 of 200 patients (91.5%): 157 (78.5%) on the first attempt. Seventeen (8.5%) were intubated using direct laryngoscopy. The first-attempt success rate was higher in the reverse than in the normal group (85.0% vs 72.0%, P=0.025), although the overall success rate was similar between the reverse and the normal groups (93.0% vs 90.0%). The incidence of sore throat was comparable in the normal group and the reverse group (22.0% vs 12.0%, NS).

CONCLUSIONS

Overall, tracheal intubation was successful in 91.5% of patients through an ILMA with a conventional tracheal tube in Mallampati class 3 or 4 patients. The first-attempt success rate was higher in the reverse group compared with the normal group, but the overall success rate was similar between the reverse and the normal groups.

Indications of conical emission of charged hadrons at the BNL relativistic heavy ion collider

Three-particle azimuthal correlation measurements with a high transverse momentum trigger particle are reported for pp, d+Au, and Au+Au collisions at sqrt[s_{NN}]=200 GeV by the STAR experiment. Dijet structures are observed in pp, d+Au and peripheral Au+Au collisions. An additional structure is observed in central Au+Au data, signaling conical emission of correlated charged hadrons. The conical emission angle is found to be theta=1.37+/-0.02(stat)-0.07+0.06(syst), independent of p_{ perpendicular}.

The Effects of Open Lung Ventilation on Respiratory Mechanics and Haemodynamics in Atelectatic Infants after Cardiopulmonary Bypass

Acute lung injury (ALI) frequently occurs in infants after cardiopulmonary bypass (CPB) surgery and it sometimes develops into acute respiratory distress syndrome in critically ill infants, which can be life threatening. This study investigated the effects of open lung ventilation on the haemodynamics and respiratory mechanics of 64 infants (34 males; 30 females) with a mean ± SD age of 8.3 ± 0.3 months who developed ALI following CPB surgery. Open lung ventilation significantly improved the respiratory mechanics and oxygenation parameters of the infants, including the partial pressure of oxygen in arterial blood (PaO2), the ratio of PaO2/FiO2 (fraction of inspired oxygen), peak inspiratory pressure, static compliance and airway resistance. It is concluded that open lung ventilation can greatly improve oxygenation and respiratory mechanics in infants with ALI following CPB surgery.

A proteomic study of peripheral blood mononuclear cells in systemic lupus erythematosus

Our objective was to analyze the changes in the protein expression profiles of peripheral blood mononuclear cells (PBMCs) in patients with systemic lupus erythematosus (SLE). Peripheral blood was obtained from patients with SLE and healthy controls. 2-D gel electrophoresis was performed, and gels were silver-stained. Differentially expressed protein spots were detected, some of which were identified by MALDI-TOF spectrometry. Match rates of 71% +/- 4% and 72% +/- 4% were gotten for control and patient gels, respectively. 791 +/- 17 spots were detected for control gels and 781 +/- 17 for patient gels. Eleven protein spots were up-regulated, and 9 protein spots were down-regulated in patients with SLE. Five differentially expressed proteins were identified as immunoglobulin J chain, apolipoprotein A-IV precursor, calprotectin L1H and zinc finger protein subfamily 1A (all up-regulated) and glutathione S-transferase (down-regulated), some of which had previously been shown to play a potential role in the pathogenesis of SLE. We conclude there are significant changes in the 2-D maps of PBMCs in patients with SLE and applying this proteomic approach may be a useful way to gain novel insights into SLE.

Automatic working area classification in peripheral blood smears without cell central zone extraction

In this paper we study automatic classification of working areas in peripheral blood smears using image analysis and recognition methods. Such automatic classification can provide objective and reproducible quality control for the evaluation of smears and smear maker devices. However, research in this filed has drawn little attention. Existing methods either can not differentiate correctly different cell distributions or rely on the extraction of the central pallor zones in cells for counting, which are not always observable. In contrast, we do not rely on the pallor zone extraction thus on more general basis. We introduce two generic parameters to measure the goodness of working areas, one for the degree of overlap, and the other for the spatial occupancy. We also propose a cascading classification network for the classification of different areas. The effectiveness of our method has been tested on over 150 labeled images acquired from three malaria-infected Giemsa-stained blood smears using an oil immersion 100 x objective.

Assessing the spatial extent of breast tumor intrinsic optical contrast using ultrasound and diffuse optical spectroscopic imaging

Abstract #806

Background: Near infrared (NIR) light is sensitive to several important tissue components and has been used to detect, characterize, and monitor breast tumor functions. However, little is known about the relationship between anatomic and functional contrast derived from intrinsic optical signals. Diffuse Optical Spectroscopic Imaging (DOSI) is a non-invasive, bedside functional imaging technique that quantifies the concentrations and molecular states of tissue hemoglobin, water, and lipids. Pilot studies have shown that DOSI may be a useful tool for breast lesion detection/characterization and therapeutic monitoring.&#x2028; Materials and Methods: DOSI data were compared with theoretical computer simulations to estimate the nature and extent of optical contrast with respect to standard ultrasound imaging. DOSI reflectance measurements were obtained from 10 breast tumor patients, with both malignant (N=5) and benign (N=5) lesions. Patient average ages: 35+/-7.8 years vs. 44.3+/-14.7 years, lesion depth 10.9+/-5.5 mm vs. 15.8+/-5.3 mm, and maximum size 13.0+/-6.0 mm vs. 14.8+/-4.9 mm for benign and malignant, respectively. Two trial tumor models were simulated to model actual tumor optical properties (hemoglobin): (a) a discrete target constrained to ultrasound dimensions, and (b) a distributed target that spatially extended beyond ultrasound dimensions.&#x2028; Results: High optical contrast (i.e., the ratio target to background) was observed for both benign (1.53+/-0.17) and malignant (2.06+/-0.4) lesions, even for this younger population. While the discrete target model could not match experiment and simulation, a distributed model provided excellent agreement. The spatial extent of optical properties in breast tumor was significantly greater than anatomical dimensions reported by ultrasound imaging. The extent of the distribution was greater in the malignant lesions than in the benign ones. Further simulations also suggested that invasive breast tumors in this population with anatomical size 10 mm may still be detectable at depth 30 mm using DOSI in reflectance.&#x2028; Discussion: The spatial extension of tumor optical contrast complicates co-registration of optical functional images with anatomic images. The true optical contrast is significantly higher in breast cancer tumors, likely 4-5x than the hemoglobin levels in normal tissues. Breast tumor optical contrast is more realistically modeled as a spatially distributed target, which facilities a fast 3D imaging scheme in reflectance geometry. Results from these topographic reconstructions will be discussed.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 806.

First measurement of the neutron beta asymmetry with ultracold neutrons

We report the first measurement of an angular correlation parameter in neutron beta decay using polarized ultracold neutrons (UCN). We utilize UCN with energies below about 200 neV, which we guide and store for approximately 30 s in a Cu decay volume. The interaction of the neutron magnetic dipole moment with a static 7 T field external to the decay volume provides a 420 neV potential energy barrier to the spin state parallel to the field, polarizing the UCN before they pass through an adiabatic fast passage spin flipper and enter a decay volume, situated within a 1 T field in a 2x2pi solenoidal spectrometer. We determine a value for the beta-asymmetry parameter A_{0}=-0.1138+/-0.0046+/-0.0021.

High-pressure needle interface for thermoplastic microfluidics

A robust and low dead volume world-to-chip interface for thermoplastic microfluidics has been developed. The high pressure fluidic port employs a stainless steel needle inserted into a mating hole aligned to an embedded microchannel, with an interference fit used to increase pressure resistance. Alternately, a self-tapping threaded needle screwed into a mating hole is also demonstrated. In both cases, the flat bottom needle ports seat directly against the microchannel substrate, ensuring low interfacial dead volumes. Low dispersion is observed for dye bands passing the interfaces. The needle ports offer sufficient pull-out forces for applications such as liquid chromatography that require high internal fluid pressures, with the epoxy-free interfaces compatible with internal microchannel pressures above 40 MPa.

Unilateral lesion of the nigrostriatal pathway induces an increase of neuronal firing of the midbrain raphe nuclei 5-HT neurons and a decrease of their response to 5-HT(1A) receptor stimulation in the rat

Several studies have shown that the 5-hydroxytryptamine (serotonin, 5-HT) system is severely affected after degeneration of nigrostriatal dopaminergic neurons. In the present study, we examined the changes in the firing rate and firing pattern of the dorsal and median raphe nuclei (DRN and MRN) 5-HT neurons, and the effect of the selective 5-HT(1A) receptor agonist (R)-(+)-8-hydroxy-2-(dipropylamino)tetralin hydrobromide (8-OH-DPAT) and antagonist (N-(2-(4-(2-methoxyphenyl)-1-piperazinyl)ethyl)-N-2-pyridylcyclohexane carboxamide maleate salt (WAY-100635) on the neuronal firing in rats with 6-hydroxydopamine (6-OHDA) lesions of the substantia nigra pars compacta by using extracellular recording. The unilateral lesion of the nigrostriatal pathway significantly increased the mean firing rate of DRN and MRN 5-HT neurons compared with normal rats, and the firing pattern of these neurons also changed significantly towards a more bursty one. The lower dose of 8-OH-DPAT, 4 microg/kg (cumulative doses, i.v.), completely inhibited the firing activity of all DRN and MRN 5-HT neurons examined in normal and sham rats. In contrast to normal and sham rats, only the higher doses of 8-OH-DPAT, 128 and 64 microg/kg, completely inhibited the firing rate of DRN and MRN 5-HT neurons in 6-OHDA-lesioned rats, respectively. Furthermore, the local application of 8-OH-DPAT, 1.5 microg, in the DRN completely inhibited the firing rate of 5-HT neurons in normal and sham rats, while having no effect on firing rate in the lesioned rats. Altogether, these results indicate that lesion of the nigrostriatal pathway leads to hyperactivity of DRN and MRN 5-HT neurons, suggesting the implication of the DRN and MRN in the pathophysiology of Parkinson's disease, and the decreased response of these 5-HT neurons to 5-HT(1A) receptor stimulation, reflecting 5-HT(1A) receptor dysfunction in 6-OHDA-lesioned rats.