Functional gene silencing mediated by chitosan/siRNA nanocomplexes

Chitosan/siRNA nanoparticles to knock down FHL2 gene expression were reported in this work. The physicochemical properties such as particle size, surface charge, morphology and complex stability of chitosan nanoparticle-incorporated siRNA were evaluated. Nanoparticles which were formulated with chitosan/siRNA exhibited irregular, lamellar and dendritic structures with a hydrodynamic radius size of about 148 nm and net positive charges with zeta-potential value of 58.5 mV. The knockdown effect of the chitosan/siRNA nanoparticles on gene expression in FHL2 over-expressed human colorectal cancer Lovo cells was investigated. The result showed that FHL2 siRNA formulated within chitosan nanoparticles could knock down about 69.6% FHL2 gene expression, which is very similar to the 68.8% reduced gene expression when siRNA was transfected with liposome Lipofectamine. Western analysis further showed significant FHL-2 protein expression reduced by the chitosan/siRNA nanoparticles. The results also showed that blocking FHL2 expression by siRNA could also inhibit the growth and proliferation of human colorectal cancer Lovo cells. The current results demonstrated that chitosan-based siRNA nanoparticles were a very efficient delivery system for siRNA in vivo as previously reported.

Mechanical Properties of Nanomaterials Examined with a NI-AFM

The mechanical properties and strain rate sensitivity of nanocrystalline nickel was studied as a function of grain size at different temperatures in tensile tests and with a nanoindenter in order to examine the different deformation mechanisms of nanocrystalline materials. The effect of lateral boundaries and hydrogen on the nucleation of dislocations was studied in detail. For the first time it was possible to observe the reduction of the dislocation nucleation stress on a nanoscale. In addition the experiments yielded, depending on temperature and strain rate, the strain rate sensitivity, the activation volume and the creep exponents as a function of stress and grain size. From the creep experiments the transition between grain boundary sliding and dislocation climb as a function of temperature was obtained. The strain rate jump tests gave extremely small activation volumes, nearly a factor of 100 smaller than in conventional nickel as a function of grain size. To help in understanding this behaviour the strain rate sensitivity of single grains was tested with a nanoindenter. The results clearly showed that the primary interaction of dislocations with grain boundaries is the reason for the observed strong rate effects and small activation volumes.

Genomic full length sequence of HLA-Cw*030301, identified by cloning and sequencing

Genomic full length sequence of human leukocyte antigen (HLA)-Cw*030301 that differs from Cw*030401 by two-nucleotide exchange at nt 473 (G>A) in exon 2 and nt 3033 (G>C) in 3'UTR, was identified by cloning and sequencing from a male Chinese donor.

Surface Conditioning Influences Zirconia Ceramic Bonding

Air-abrasion seems to be mandatory for durable resin bonding to zirconia ceramic. Air-abrasion might compromise the ceramic strength by creating surface defects. Therefore, omitting air-abrasion or using reduced air-pressure seems desirable. We tested the null hypotheses that omitting air-abrasion or using reduced air-pressure does not affect zirconia ceramic bonding independent of using primers. Three mechanical surface conditions (polished, air-abraded at 0.05 or at 0.25 MPa) and 4 priming conditions were tested. After different surface conditioning, zirconia ceramic specimens were bonded, and tensile bond strengths were evaluated after water storage for 3 days or for 150 days with additional 37,500 thermal cyclings for artificial aging. Omitting air-abrasion resulted in debonding during artificial aging independent of using primers. The combination of air-abrasion and priming improved long-term resin bonding to zirconia ceramic significantly. With low-pressure air-abrasion, surface roughness was reduced without affecting long-term bond strength, provided that adequate adhesive primers were applied.

Rebound bursts in GABAergic neurons of the thalamic reticular nucleus in postnatal mice

Whole cell patch-clamp recordings from GABAergic cells of thalamic reticular nucleus (RTN) in thalamocortical slices made from postnatal day 6 (P6) to 10 (P10) were used to investigate the pattern of rebound bursts (RBs) triggered by an injection of hyperpolarizing current into RTN cells. The number of RBs in the RTN and the overlying Na(+)/K(+) spikes changed in an age-dependent manner. The generation of RBs depended largely on the amplitude of the after-hyperpolarizations (AHPs). RB patterns in response to hyperpolarizing current injection into relay cells were markedly different from RB patterns in RTN cells with an after-depolarization. GABA(A) receptor antagonist bicuculline methiodide (BMI) changed burst firing patterns, increasing the duration of RB and decreasing the amplitude of AHP in RTN cells. Furthermore, local puffs of NMDA in the presence of BMI induced RBs. K(+) channel blocker 4-aminopyridine partially mimicked the effect of BMI on AHPs. The shapes of RBs were altered by a selective CaMKII inhibitor KN-62, but not by an inactive analog KN-04.

Mesothelin as a marker of response in malignant pleural mesothelioma

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Background: Malignant pleural mesothelioma (MPM) is a rare malignancy related to asbestos exposure. Radiological assessment of disease status and treatment response using RECIST criteria is often difficult, therefore blood markers of disease burden may be useful adjunctively. Soluble mesothelin related peptide (sMRP) can distinguish between MPM and benign pleural disease. We performed an exploratory analysis to determine whether sMRP correlates with MPM disease course. Methods: From December 2006 to August 2008 blood samples were collected from MPM patients during clinic visits. Plasma sMRP levels were measured using the MESOMARK assay (Fujirebio diagnostics). Changes in sMRP levels were compared with corresponding radiological tests, scored as progression, stable or disease shrinkage. Results: From 41 patients, 165 samples were collected (median 4/patient; range 2–10). At study entry 34/37 (92%) patients with measurable disease had elevated sMRP (>9ng/ml, range 14–60). In 22 patients receiving chemotherapy or biologic therapy, relative (Fisher's exact test, p=3.2x10–6) and absolute (p=2.6x10–5) changes in sMRP correlated with radiological assessment (Table). All 4 post-surgery surveillance patients, with no evidence of recurrence, had normal sMRP levels (1.8–4.9). Of 8 patients who underwent surgical resection, 7 had elevated pre-operative sMRP that fell to normal post-operatively (Wilcoxon rank (WR) p=0.02). Absolute sMRP rose in all patients with radiological progression (systemic therapy, n=9, WR p=0.004; supportive care, n=10, WR p=0.02). Conclusions: sMRP levels not only correlate with surgical debulking but we report, for the first time, that they also correlate with treatment response and radiological progression in MPM patients undergoing systemic therapy or supportive care. sMRP may be a clinically useful biomarker in MPM clinical trials and in patient management. These findings should be validated prospectively.

[Table: see text]

[Table: see text]

Pegfilgrastim in pediatric sarcoma patients undergoing dose-intensive chemotherapy: Phase II study results

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Background: Children with cancer undergoing dose-intensive chemotherapy often require G-CSF support. Patients (pts) < 2 yrs have the highest risk of prolonged neutropenia due to imprecise dosing and immature drug clearance. Once-per-cycle pegfilgrastim may be beneficial due to neutrophil-mediated clearance that allows adequate serum levels throughout the neutropenic period. Young pts, who receive relatively more myeloablative chemotherapy, should have the highest pegfilgrastim exposure. Methods: Pts ≤21 yrs (age groups 0–5, 6–11, and ≥12 yrs) with sarcoma and scheduled to receive VAdriaC (cycles 1 & 3) and IE (cycles 2 & 4) were randomized 6:1 to receive pegfilgrastim 100 μg/kg or filgrastim (5 μg/kg/d until ANC ≥ 10×109/L) 24 hrs after chemotherapy administration. Post-nadir ANC recovery, incidence of ANC recovery by day 21 of cycles 1 & 3, pharmacokinetics (PK), and safety by age group were evaluated. Results: 43 pts (63% male) received pegfilgrastim (n=37) or filgrastim (n=6). Maximum pegfilgrastim concentration was achieved ∼24-hrs postdose and sustained until ANC nadir. Pegfilgrastim levels fell rapidly as ANC recovered. One child did not achieve ANC recovery by day 21 in cycle 1: an 8-mo-old 7.9-kg boy with non-metastatic undifferentiated sarcoma had 24 days of severe neutropenia in cycle 1. The youngest age group (including this child) had longer duration of severe neutropenia and, consequently, higher pegfilgrastim exposure ( Table ). Treatment-related adverse events were generally mild to moderate (pegfilgrastim 22%, filgrastim 33%); the only treatment-related event reported by >1 pt was bone pain (pegfilgrastim=11%, filgrastim=17%). Conclusions: ANC, PK, and safety profiles in pediatric patients were comparable with those in adults and support pegfilgrastim dosing across pediatric age groups. Consistent with neutrophil-mediated clearance, adequate exposure to pegfilgrastim was maintained in the youngest pts who received the most myelosuppressive chemotherapy.

[Table: see text]

[Table: see text]

MR imaging findings of the uveal schwannoma

BACKGROUND AND PURPOSE

Uveal schwannoma is a rare benign neoplastic proliferation of pure Schwann cells. The purpose of this study was to describe MR imaging features of uveal schwannoma.

MATERIALS AND METHODS

MR images in 6 female patients with uveal schwannoma confirmed by pathologic examination were retrospectively reviewed. MR imaging was performed in all 6 patients, with postcontrast T1-weighted imaging (T1WI) completed in all 6 patients and dynamic contrast-enhanced MR imaging, in 5. MR imaging findings of the tumor were evaluated with emphasis on the location, size, shape, margin, signal intensity, and pattern of enhancement.

RESULTS

The lesions appeared as solitary well-defined ovoid masses in the ciliochoroidal region in 5 patients and in the choroid in 1. With respect to the vitreous body, uveal schwannoma was hyperintense on T1WI spin-echo (SE) images in all 6 patients. The tumors were hypointense to the vitreous body on fast SE (FSE) T2-weighted images (T2WI) in 4 patients and isointense in 1. However, with respect to the brain, uveal schwannoma demonstrated isointensity on T1WI SE images in all 6 patients, isointensity on FSE T2WI images in 5 patients, and hyperintensity on T2WI SE images in 1. On postcontrast T1WI images, 3 patients showed markedly heterogeneous enhancement, and 3 showed markedly homogeneous enhancement.

CONCLUSIONS

Uveal schwannoma should be included in the differential diagnosis when an oval isointense mass relative to brain is seen in the ciliochoroidal region.

A pig-human comparative RH map comprising 20 genes on pig chromosome 13q41 that harbours the ETEC F4ac receptor locus

The enterotoxigenic Escherichia coli (ETEC) F4ac is a major cause of diarrhoea in newborn and young pigs. The locus for the intestinal ETEC F4ac receptor (F4acR) has been mapped to pig chromosome (SSC) 13q41 with known homology to human chromosome (HSA) 3q21 and q29. However, the causative gene and mutation(s) remain unknown. The aim of this study was to characterize gene-derived markers on SSC13q41 for fine mapping of the F4acR locus, and construct a high-resolution pig-human comparative map to select positional candidate genes for F4acR. Pig-specific sequence-tagged site markers were developed for 20 genes that are located in a 6.8-Mb region on HSA3q21 and q29, and a total of 34 single-nucleotide polymorphisms (SNPs) were identified in 14 of 20 markers developed. Eighteen markers were mapped to SSC13q41, while the other two markers (PLXNA1 and KLF15) were assigned to SSC13q32 and SSC7q13, respectively, by radiation hybrid mapping. This result showed that there was a small conserved segment on SSC7 corresponding to HSA3q21. A framework map comprising 18 markers on SSC13q41 was established, refining the synteny breakpoint on SSC13q41 to a region of 12.3 centiRay. The comparative radiation hybrid (RH) map revealed three interesting candidate genes for F4acR from the human genome, viz. MUC4, MUC13 and MUC20. Linkage analysis with six marker polymorphisms revealed that MUC4 had the most significant linkage with the F4acR locus.

High-level secretory production of recombinant human platelet-derived growth factor--BB by Saccharomyces cerevisiae under the non-selective conditions

Recombinant human platelet-derived growth factor-BB (rhPDGF-BB) was produced by Saccharomyces cerevisiae. A two-stage cultivation strategy with mixture of glucose and galactose was developed to enhance rhPDGF-BB production, with its concentration being 32 mg/l fermentation broth under optimal conditions: corn steep powder as nitrogen source, 2 g/1 of glucose concentration at the beginning of induction phase, a pH of 5.0 and 6.5 for cell growth and rhPDGF-BB accumulation. The purification process consisted of yeast supernatant ultrafiltration followed by ion exchange chromatography and molecular sieve, and the recovery of rhPDGF-BB was estimated to be 20.28%. Biological activity of the purified rhPDGF-BB was 3.05 ng/ml.

Quantitative trait loci for porcine white blood cells and platelet-related traits in a White Duroc x Erhualian F resource population

White blood cell count and platelets are implicated as risk factors for common complex diseases. Genetic factors substantially affect these traits in humans and mice. However, little is known about the genetic architecture of these traits in pigs. To identify quantitative trait loci (QTL) for leucocyte- and platelet-related traits in pigs, the total leucocyte number and differential leucocyte counts including the fraction of basophils, eosinophils, lymphocytes, monocytes, neutrophils, and a series of platelet parameters including platelet count, mean platelet volume, platelet distribution width and plateletcrit were measured in 1033 F(2) animals on 240 days from a White Duroc x Erhualian intercross resource population. A total of 183 informative microsatellites distributed across 19 pig chromosomes (SSC) were genotyped across the entire resource population. Thirty-three QTL were identified for the examined traits, including eight genome-wide significant QTL for white blood cells and differential leucocyte counts on SSC2, 7, 8, 12 and 15 and six significant QTL for platelet-related traits on SSC2, 8, 13 and X. Erhualian or White Duroc alleles were not systematically associated with increased phenotypic values. These results not only confirmed many QTL identified previously in the mouse and swine, but also revealed a number of novel QTL for the traits recorded. Moreover, it is the first time that QTL for platelet-related traits in pigs have been reported.

Variation in content of monomeric phenolics during the processing of grape seed and skin flours

Phenolic compounds were extracted from grape seed and skin flours. Three major monomeric phenolics, gallic acid, (+)-catechin and (−)-epicatechin, were identified and quantified by high performance liquid chromatography. To evaluate the feasibility of using both flours for the development of phenolic-rich functional foods, the variation in content of these monomeric phenolics were determined after baking, illumination and microwave radiation processes. The results showed that baking both flours at 110°C had no significant influence on the contents of the three monomeric phenolics. However, after baking at 145°C, the contents of gallic acid exhibited an increasing trend, while the contents of (+)-catechin and (−)-epicatechin gradually declined. During the illumination process, the contents of gallic acid and (+)-catechin in both flours increased, while (−)-epicatechin decreased after 10 days. Microwave processing baked flours for 1 min had no significant effect on the contents of these three monomeric phenolics. After processing for 3 and 5 min, the gallic acid contents significantly increased, but the other two decreased. These results indicated that producing foods containing grape seed or skin flours should avoid being baked at higher temperatures for long periods, and the microwave radiation process should be performed as quickly as possible, so that the phenolic ingredients in these foods are better retained.

The involvement of GABA-C receptors in paired-pulse depression of inhibitory postsynaptic currents in rat hippocampal CA1 pyramidal neurons

In rat hippocampal CA1 pyramidal neurons, gamma-aminobutyric acid (GABA) A receptor-mediated inhibitory postsynaptic currents (IPSCs) undergo a paired-pulse depression (PPD) by the second of two pulses, with inter-pulse intervals of 100-2000 ms, applied to the stratum radiatum. While GABA-C receptors are described in the CA1 area, their functional significance is unknown. In this study, the involvement of GABA-C receptors in PPD was examined using an in vitro hippocampal slice preparation. IPSCs evoked by stimulations in stratum radiatum were recorded with patch pipettes from CA1 pyramidal cells. PPD, when induced in the above fashion, was blocked by the GABA-C receptor antagonist (1,2,5,6-Tetrahydropyridin-4-yl) methylphosphinic acid (TPMPA, 10 muM, applied in the superfusing medium). GABA-A and GABA-B receptor-mediated IPSCs, as well as the baclofen-induced suppression of the GABA-A receptor mediated IPSC, were not antagonized by TPMPA (10-20 muM). These results indicate that PPD of the IPSC is mediated by the activation of GABA-C receptors.

An Improved Prognostic Parameter for Non-Hodgkin's Lymphoma Based on the Combination of Three Serum Tumor Markers

We aimed to evaluate the prognostic value of the combination of three serum tumor markers (LDH, β2-M and CA 125) in patients with non-Hodgkin's lymphoma (NHL). Clinical and pathological variables including the levels of these markers were measured in 415 NHL patients. Statistical analysis showed that increased levels of all three markers were associated with stage, B symptoms, effusions, bone marrow involvement, and International Prognostic Index (IPI) in NHL patients (p<0.05). Overall survival and event-free survival rates were associated not only with LDH but also with β2-M and CA125 (p<0.001). Response to treatment and overall survival rates were different in three groups with elevated LDH; in particular, the combination of three or two elevated markers seemed to identify a group of patients at higher risk of treatment failure and/or relapse than the group with a high LDH level only. Furthermore, multiple Cox regression analysis showed that IPI score complemented by the additional serum markers β2-M and CA125 was a better prognosticator of overall and event-free survival than LDH alone. This result suggests that if the combination of three elevated serum tumor markers is included as a parameter in the IPI instead of LDH alone, the prognostic value of IPI can be improved.