Next-generation small RNA sequencing for microRNAs profiling in the honey bee Apis mellifera

MicroRNAs (miRNAs) are key regulators in various physiological and pathological processes via post-transcriptional regulation of gene expression. The honey bee (Apis mellifera) is a key model for highly social species, and its complex social behaviour can be interpreted theoretically as changes in gene regulation, in which miRNAs are thought to be involved. We used the SOLiD sequencing system to identify the repertoire of miRNAs in the honey bee by sequencing a mixed small RNA library from different developmental stages. We obtained a total of 36,796,459 raw sequences; of which 5,491,100 short sequences were fragments of mRNA and other noncoding RNAs (ncRNA), and 1,759,346 reads mapped to the known miRNAs. We predicted 267 novel honey bee miRNAs representing 380,182 short reads, including eight miRNAs of other insects in 14,107,583 genome-mapped sequences. We verified 50 of them using stem-loop reverse-transcription PCR (RT-PCR), in which 35 yielded PCR products. Cross-species analyses showed 81 novel miRNAs with homologues in other insects, suggesting that they were authentic miRNAs and have similar functions. The results of this study provide a basis for studies of the miRNA-modulating networks in development and some intriguing phenomena such as caste differentiation in A. mellifera.

Internal dynamics of actin structures involved in the cell motility and adhesion: Modeling of the podosomes at the molecular level

Podosomes are involved in the spreading and motility of various cells to a solid substrate. These dynamical structures, which have been proven to consist of a dense actin core surrounded by an actin cloud, nucleate when the cell comes in the vicinity of a substrate. During the cell spreading or motion, the podosomes exhibit collective dynamical behaviors, forming clusters and rings. We design a simple model aiming at the description of internal molecular turnover in a single podosome: actin filaments form a brush which grows from the cellular membrane whereas their size is regulated by the action of a severing agent, the gelsolin. In this framework, the characteristic sizes of the core and of the cloud, as well as the associated characteristic times are expressed in terms of basic ingredients. Moreover, the collocation of the actin and gelsolin in the podosome is understood as a natural result of the internal dynamics.

Cell apoptosis and Fas gene expression in liver and renal tissues after ischemia-reperfusion injury in liver transplantation

Ischemia-reperfusion (I/R) injury is an important factor in a nonfunctioning liver graft and acute renal failure. Apoptosis is a cell death mechanism in early stages of I/R injury. In the present study, orthotopic liver transplantation (oLT) using a modified double-cuff method was performed in Wistar rats, with sham-operated rats serving as the control group. Rats in the treatment and control groups were sacrificed at 1, 3, 6, 12, and 24 hours after oLT to obtain liver and kidney tissues. Fas protein expression in apoptotic cells at various times was detected at immunohistochemical staining and flow cytometry, and Fas gene expression was detected using the reverse transcriptase polymerase chain reaction. Apoptosis began in liver and renal cells at 1 hour after oLT, peaking at 12 hours. The reverse transcriptase polymerase chain reaction demonstrated Fas gene expression in liver and renal tissues at 1 hour post-oLT, peaking at 12 hours. Changes in the treatment group were significantly greater than in the control group (P < .05). We conclude that renal cells, like liver cells, undergo apoptosis due to I/R injury after oLT.

Midrapidity antiproton-to-proton ratio in pp collisons at sqrt[s]=0.9 and 7 TeV measured by the ALICE experiment

The ratio of the yields of antiprotons to protons in pp collisions has been measured by the ALICE experiment at sqrt[s]=0.9 and 7 TeV during the initial running periods of the Large Hadron Collider. The measurement covers the transverse momentum interval 0.45<p_{t}<1.05  GeV/c and rapidity |y|<0.5. The ratio is measured to be R_{|y|<0.5}=0.957±0.006(stat)±0.014(syst) at 0.9 TeV and R_{|y|<0.5}=0.991±0.005(stat)±0.014(syst) at 7 TeV and it is independent of both rapidity and transverse momentum. The results are consistent with the conventional model of baryon-number transport and set stringent limits on any additional contributions to baryon-number transfer over very large rapidity intervals in pp collisions.

The Eyes Absent phosphatase-transactivator proteins promote proliferation, transformation, migration, and invasion of tumor cells

The Eyes Absent (EYA) proteins combine transactivation, tyrosine phosphatase, and threonine phosphatase activities in their function as part of a conserved regulatory cascade involved in embryonic organ development. EYA tyrosine phosphatase activity contributes to fly eye development, and vertebrate EYA is involved in promoting DNA damage repair subsequent to genotoxic stress. EYAs are known to be expressed at elevated levels in ovarian and breast cancers. Here, we show that the tyrosine phosphatase activity of the EYAs promotes tumor cell migration, invasion, and transformation. These cellular effects are accompanied by alterations of the actin cytoskeleton and increased levels of active Rac and Cdc42. The invasiveness conferred by EYA is reflected in vivo by inhibition of metastasis seen when EYA3 expression is silenced in the invasive breast cancer cell line MDA-MB-231. Together, our data directly associate the tyrosine phosphatase activity of the EYAs with the oncogenesis-associated cellular properties of motility and invasiveness.

Better induction and differentiation strategy for rat pancreatic stem cells: transplant in liver niche

Current in vitro induction protocols cannot generate mature islet cells from stem cells. Transplantation into the liver niche may greatly contribute to the maturity of pancreatic stem cells (PSCs) due to its similarity to the pancreas. To determine the effect of the liver niche on the differentiation of PSCs, we used neonatal Wistar rat pancreata for cultivation of PSCs, which were transplanted into diabetic Wistar rats via the portal vein or beneath the renal capsule. After transplantation, we measured random blood glucose, weight, and serum insulin and performed an intraperitoneal glucose tolerance test. Specimens were examined by immunofluorescence. As a result, highly proliferating harvested cells showed the characteristics of stem cells. The PSCs could be induced to form large islet-like structures (150-200 mum diameter) in the liver, which resulted in better therapeutic efficacy. In contrast, there were smaller islet-like structures (about 50 mum diameter) when PSCs were transplanted beneath the renal capsule. These findings demonstrated that the liver niche benefits the in vivo differentiation of PSCs into endocrine and exocrine cells that may contribute to the generation of insulin producing cells.

Insight into the dicrotic notch in photoplethysmographic pulses from the finger tip of young adults

This study aims to investigate arterial stiffness in selected young adults by non-invasively determining the characteristics of the photoplethysmographic dicrotic notch. A total of 15 volunteers participated in this study, divided into four groups by age and gender. Contour analysis was applied to analyse the photoplethysmographic dicrotic notch, including time-related and height-related parameters. The height of reflected wave, mirrored by the notch relative amplitude (NRA), was found to be significantly larger in the older group compared to the younger group (p = 0.016). The timing of the reflected wave, measured by three parameters, i.e. notch index (NI), notch latency (NL) and peak-to-notch latency (PTNL), significantly increased in the female group compared to the male group (all p < 0.02). The results confirm that arterial stiffness occurs in young adults, and demonstrate that a difference of arterial stiffness exists between young male and female. This study indicates that examining the characteristic notch of the PPG pulse could help in identifying differences of vascular activities.

Reoperation of biliary tract by laparoscopy

BACKGROUND

Patients with previous operation of biliary tract were considered in the past as a contraindication to perform reoperation by laparoscopy. As experience with laparoscopic techniques and instrumentation has expanded, laparoscopic reoperation of biliary tract has become an accepted procedure in the management of cholelithiasis. Here we introduce our interesting experience with regard to reoperation of biliary tract by laparoscopy.

METHODS

Laparoscopic operation of biliary tract was performed on 3,674 consecutive patients from April 1992 to June 2005. Among these patients, 26 had a previous open operation of biliary tract whose clinical data were analyzed retrospectively : seven cases had complicated intrahepatic bile duct stones (restricted at hepatic duct of the first and the 2nd order); Diameter of common bile duct in patients with common duct stones was above 1.2 cm and the numbers of stones from each patient was more than 3 and the biggest stone exceeded 1 cm. All 26 patients were preoperatively excluded to present stenosis of bile duct and malignant tumor by both radiological examination and detection of serological tumor markers.

RESULTS

The mean operative time was 125 min (75-190 min). Reoperations of biliary tract by laparoscopy were successfully accomplished in 25 patients. One patient was converted to open operation whose common duct stones were taken out by right angle forceps through a short incision. None of the patients developed any severe complication and all of them recovered and were discharged. Three cases with retained calculus were successfully cured by taking them out through the sinus tract of T tube.

CONCLUSIONS

Laparoscopic procedure is minimally invasive, is safe and feasible for reoperation of the biliary tract. And it is a first choice method for cases to whom endoscopic sphincterotomy is contraindicated.

Aspirin induces apoptosis in mesenchymal stem cells requiring Wnt/beta-catenin pathway

BACKGROUND AND OBJECTIVES

Mesenchymal stem cells (MSC) are multipotent progenitor cells that are have found use in regenerative medicine. We have previously observed that aspirin, a widely used anti-inflammatory drug, inhibits MSC proliferation. Here we have aimed to elucidate whether aspirin induces MSC apoptosis and whether this is modulated through the Wnt/beta-catenin pathway.

MATERIALS AND METHODS

Apoptosis of MSCs was assessed using Hoechst 33342 dye and an Annexin V-FITC/PI Apoptosis Kit. Expression of protein and protein phosphorylation were investigated using Western blot analysis. Caspase-3 activity was detected by applying a caspase-3/CPP32 Colorimetric Assay Kit.

RESULTS

In these MSCs, aspirin induced morphological changes characteristic of apoptosis, cytochrome c release from mitochondria, and caspase-3 activation. Stimulating the Wnt/beta-catenin pathway by both Wnt 3a and GSK-3beta inhibitors (LiCl and SB 216763), blocked aspirin-induced apoptosis and protected mitochondrial function, as demonstrated by decreased cytochrome c release and caspase-3 activity. Aspirin initially caused a time-dependent decrease in COX-2 expression but subsequently, and unexpectedly, elevated the latter. Stimulation of COX-2 expression by aspirin was further enhanced following stimulation of the Wnt/beta-catenin pathway. Application of the COX-2 inhibitor NS-398 suppressed elevated COX-2 expression and promoted aspirin-induced apoptosis.

CONCLUSION

These results demonstrate that the Wnt/beta-catenin pathway is a key modulator of aspirin-induced apoptosis in MSCs by regulation of mitochrondrial/caspase-3 function. More importantly, our findings suggest that aspirin may influence MSC survival under certain conditions; therefore, it should be used with caution when considering regenerative MSC transplantation in patients with concomitant chronic inflammatory diseases such as arthritis.

A comparison of regional and general anaesthesia for total replacement of the hip or knee: a meta-analysis

We performed a meta-analysis to evaluate the relative efficacy of regional and general anaesthesia in patients undergoing total hip or knee replacement. A comprehensive search for relevant studies was performed in PubMed (1966 to April 2008), EMBASE (1969 to April 2008) and the Cochrane Library. Only randomised studies comparing regional and general anaesthesia for total hip or knee replacement were included. We identified 21 independent, randomised clinical trials. A random-effects model was used to calculate all effect sizes. Pooled results from these trials showed that regional anaesthesia reduces the operating time (odds ratio (OR) -0.19; 95% confidence interval (CI) -0.33 to -0.05), the need for transfusion (OR 0.45; 95% CI 0.22 to 0.94) and the incidence of thromboembolic disease (deep-vein thrombosis OR 0.45, 95% CI 0.24 to 0.84; pulmonary embolism OR 0.46, 95% CI 0.29 to 0.80). Regional anaesthesia therefore seems to improve the outcome of patients undergoing total hip or knee replacement.

Filamin A is essential for active cell stiffening but not passive stiffening under external force

The material properties of a cell determine how mechanical forces are transmitted through and sensed by that cell. Some types of cells stiffen passively under large external forces, but they can also alter their own stiffness in response to the local mechanical environment or biochemical cues. Here we show that the actin-binding protein filamin A is essential for the active stiffening of cells plated on collagen-coated substrates. This appears to be due to a diminished capability to build up large internal contractile stresses in the absence of filamin A. To show this, we compare the material properties and contractility of two human melanoma cell lines that differ in filamin A expression. The filamin A-deficient M2 cells are softer than the filamin A-replete A7 cells, and exert much smaller contractile stresses on the substratum, even though the M2 cells have similar levels of phosphorylated myosin II light chain and only somewhat diminished adhesion strength. In contrast to A7 cells, the stiffness and contractility of M2 cells are insensitive to either myosin-inhibiting drugs or the stiffness of the substratum. Surprisingly, however, filamin A is not required for passive stiffening under large external forces.

Imaging considerations for in vivo 13C metabolic mapping using hyperpolarized 13C-pyruvate

One of the challenges of optimizing signal-to-noise ratio (SNR) and image quality in (13)C metabolic imaging using hyperpolarized (13)C-pyruvate is associated with the different MR signal time-courses for pyruvate and its metabolic products, lactate and alanine. The impact of the acquisition time window, variation of flip angles, and order of phase encoding on SNR and image quality were evaluated in mathematical simulations and rat experiments, based on multishot fast chemical shift imaging (CSI) and three-dimensional echo-planar spectroscopic imaging (3DEPSI) sequences. The image timing was set to coincide with the peak production of lactate. The strategy of combining variable flip angles and centric phase encoding (cPE) improved image quality while retaining good SNR. In addition, two aspects of EPSI sampling strategies were explored: waveform design (flyback vs. symmetric EPSI) and spectral bandwidth (BW = 500 Hz vs. 267 Hz). Both symmetric EPSI and reduced BW trended toward increased SNR. The imaging strategies reported here can serve as guidance to other multishot spectroscopic imaging protocols for (13)C metabolic imaging applications.

Phase I study of pemetrexed (P) and pegylated liposomal doxorubicin (PLD) in patients with refractory breast, ovarian, primary peritoneal, or fallopian tube cancer

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Background: P and PLD are clinically active as single agents and synergistic in preclinical models. This phase I, open-label trial determined the maximum tolerated dose (MTD) and safety profile of P followed by PLD in patients (pts) with breast or gynecologic cancers. Methods: Using standard phase I (3+3 dose escalation) study design, cohorts of 3–9 pts received escalating doses of P followed by PLD in 28-day cycles: P 400–500 mg/m2 on Days 1 and 15 and PLD 30–45 mg/m2 on Day 1. All pts received folic acid (350–1000 μg daily) and vitamin B12 (1000 μg) until 21 days after last dose of P. Pts continued until dose-limiting toxicity (DLT) or disease progression (PD) occurred. Results: From 11/05 to 1/08, 29 pts were registered/treated. Median age: 60.6 years (range, 47.5–80.1); ECOG performance status 0/1: 28%/72%; primary disease sites: ovarian (55%), breast (35%), peritoneal (10%); prior therapies: chemotherapy (100%), surgery (72%), hormones/biologics (35%), radiation (21%). Dosing results are shown below. At dose level (L) 2 and L3, 1 pt/cohort had DLTs; L5 was added and 3/3 pts had DLTs; 4 more pts were treated at L4 (1 pt replaced). Most frequent drug-related Grade 3–4 hematologic toxicities: neutropenia (86%), leukopenia (59%), thrombocytopenia (48%), anemia (41%). Most frequent drug-related Grade 3–4 nonhematologic toxicities: hand-foot syndrome (14%), hypokalaemia (10%). Major reasons for discontinuation: PD (48%), toxicity (28%), pt request (14%). Overall best responses (n=24): 5 pts (21%) had partial response (PR), 14 pts (58%) had stable disease (SD), 2 pts (8%) had PD, 3 pts (13%) were not evaluable. All 5 PR and 8 SD pts were ovarian; 5 SD and both PD pts were breast. Conclusions: P followed by PLD was reasonably tolerated in this heavily-pretreated population. The MTD was P 500 mg/m2 and PLD 40 mg/m2. These dose levels may be carried forward to phase II studies in more specific patient populations.

[Table: see text]

[Table: see text]

Preliminary results of a randomized phase II study of paclitaxel and bevacizumab ± gemcitabine as first-line treatment for metastatic breast cancer

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Background: The addition of bevacizumab (B) to paclitaxel (P) results in a significant improvement in PFS in pts with metastatic breast cancer (MBC) (Miller K, et al. New Engl J Med 2007). A randomized Phase II trial examining the efficacy and safety of adding gemcitabine (G) to the PB doublet has completed enrollment. Reported here are preliminary efficacy and safety results. Methods: This is a US, multicenter, randomized, superiority trial. Eligible pts have locally advanced or metastatic breast cancer, ECOG PS 0 or 1, and no prior cytotoxic therapy for metastatic disease. Prior adjuvant or neoadjuvant treatment with a taxane or endocrine therapy is allowed. Pts are randomized to receive P 90 mg/m2 on Days 1, 8, and 15, followed by B 10 mg/kg on Days 1 and 15 of a 28-day cycle, or the same regimen plus G 1,500 mg/m2 on Days 1 and 15. Primary endpoint is response rate according to RECIST criteria. Results: Between May 2006 and February 2008, 189 women were randomized to treatment. The table below summarizes currently available results. Grades 1–2 alopecia occurred in 28% of pts in the PB arm and in 38% of pts in the PB+G arm. One pt (2%) in the PB arm experienced a Grade 3 nosebleed. Grades 3 and 4 thrombotic events occurred respectively in 0% and 2% of pts in the PB arm, and in 3% and 2% of pts in the PB+G arm. Four pts (7%) in the PB arm and 3 pts (5%) in the PB+G arm discontinued due to treatment-related AEs. Three on-study deaths have occurred, none deemed related to study treatment. Conclusions: Study follow-up is ongoing. Full results will be available at the time of the meeting. Therapy with PB ± G is feasible and does not appear to be associated with significant bleeding or thrombotic events. As expected, the addition of G to the PB doublet appears to increase the incidence of neutropenia in pts with MBC.

[Table: see text]

[Table: see text]