Transplantation of embryonic small hepatocytes induces regeneration of injured liver in adult rat

Small hepatocytes as hepatic stem cells or progenitors may be transplanted to treat several end-stage liver diseases. To identify the characteristics of epithelial cells enriched from fetal liver, we used immunocytochemistry and electron micrography. All cells in the colonies were immunocytochemically positive for alpha fetoprotein and cytokeratins (CK) 7, CK8, and CK18, which are markers of hepatic progenitor. Under transmission electron microscopy, we observed the cultured cells to show naive characteristics of stem cells and to be significantly distinct from mature hepatocytes. To identity whether these small hepatocytes were able to proliferate and differentiate into mature hepatocytes, we cultured them in vitro, and, through the portal vein, and transplanted elements whose membrane were stained with red fluorescence using PKH26 linker dye, into the livers of CCl(4)-treated rats that had been subjected to two-thirds partial hepatectomy. Significant liver regeneration was observed 30 days later in rats that did or did not receive the cells. The livers of hepatocytes recipients showed sharper edges and smoother surfaces than the control group. Diffused cells labeled with red fluorescence were observed in the portal area, with branch-like red fluorescence in regions near portal areas of some lobules, suggesting that these elements were involved in the repair of liver lobules and differentiation into mature hepatocytes. Our results revealed that small hepatocytes not only have characteristics of hepatic stem cells, but also may be a source of cellular transplantation to treat liver diseases.

Chronic lumbar paraspinal compartment syndrome: a case report and review of the literature

A 25-year-old male weightlifter felt increasing intractable low back pain during training but denied any acute injury. The physical examination, blood parameters, radiographs and MRI were unremarkable. He had been treated non-operatively by various means, with only temporary relief. The pressures in the lumbar paraspinal compartment were abnormally high and he was treated by surgical decompression. This gave rapid relief, he returned to training, and one year later the pain had not recurred.

Effects of Various Fluoride Solutions on Enamel Erosion in vitro

The objective of this in vitro study was to investigate the effect of different fluoride solutions on enamel erosion. Human enamel specimens were pretreated with 1 of 10 different fluoride solutions (n = 20): TiF₄, NaF, AmF, ZnF₂, or SnF₂, each at native pH (pH range: 1.2–7.8) or buffered pH (pH = 4). The control group samples received no fluoride pretreatment. All samples were then eroded by citric acid (pH 2.6) for 6 × 1 min daily over 5 days. Between the erosive cycles, the samples were stored in artificial saliva. Erosion effects were investigated by surface profilometry (n = 10), scanning electron microscopy (n = 4), and energy-dispersive X-ray spectroscopy (n = 6) after fluoride pretreatment and after erosion. To test the effects of pH only, additional experiments were carried out with fluoride-free solutions at similar pH to that of fluoride solutions. In general, AmF solution was more effective in protecting enamel erosion compared to all other fluoride agents. However, the application of native TiF₄, native and buffered SnF₂, and native and buffered AmF solutions also resulted in significantly less enamel loss compared to the control group. A Ti-rich coating was formed after application of native TiF₄, but partially dissolved due to erosive attack. Samples pretreated with SnF₂ showed a significant increase in surface tin content. Surface fluoride concentration was significantly increased by native TiF₄, native and buffered AmF, buffered ZnF₂, and buffered NaF application. Under the current experimental setting, the fluoride agents at lower pH had better protective potential. Highly concentrated TiF₄, AmF, and SnF₂ solution was effective in inhibiting erosion of enamel.

Radiation-Induced S-Nitrosylation of ER-α Predisposes MCF-7 Breast Cancer Cells to Aggressive Invasion and Migration

The objective of this study is to decipher the potentials of breast cancer cells that survive radiation exposure at clinical doses to acquire invasive and metastatic determinants. In this study we exposed estrogen receptor positive (MCF-7) and negative (MDAMB-231) breast cancer cells to clinical doses of low LET radiation including doses used as single fraction (2Gy), cumulative dose (10Gy) and scattered dose (10cGy). The cells were exposed to 137Cs source at a dose rate of 1.27 Gy/min. The mock irradiated cells were used as controls. The mRNA transcript level, protein expression and protein-protein interaction were analyzed by QPCR/RT-PCR, immunoblotting, immunoprecipitation and mammalian two-hybrid system, respectively. Intracellular nitric oxide (NO) levels were determined by immunofluorescence and electron spin resonance spectroscopy (ESR) using DAF-FM and Fe-MGD as NO traps, respectively. NO-dependent ER-α s-nitrosylation was determined through immunoprecipitating s-nitrosylated proteins from the cell lysates with an s-nitrosylated-cysteine IgG antibody followed by ER-α western blot analysis. Transactivation of ER-α was measured by EMSA and luciferase reporter assay. Cell invasion and migration were examined by co-culture system using thin inserts.Radiation induces eNOS expression and activation through the phosphorylation of eNOS at Ser1177 site resulting in increased bioavailability of NO in a dose- and time-dependent manner. The three-fold bioavailability of NO s-nitrosylates ER-α leading to a two-fold binding of ER-α to ERE. Paradoxically, this binding did not translate into the transcriptional activation of ER-α dependent gene regulation. Altered structure due to s-nitrosylation of ER-α contributes to enhanced cell invasion and cell migration. In consistent with these results, there was an associated 2.3-fold increase in the expression of MMP-2 and MMP-9 and corresponding TIMP-1 decreased expression leading to a 3.5-fold increase in MMP activity. Radiation, while controlling tumor growth, could simultaneously play a significant role in breast cancer relapse and metastasis through the activation of eNOS and the generation of NO. The bioavailability of NO s-nitrosylates ER-α leading to re-defining the genomic functions of ER-α and thereby impart metastatic transformation potentials to ER-α positive breast cancer cells.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 6162.

Low LET Radiation-Induced Abscopal Effect and Tumor Recurrence: Nuclear Factor Kappa B (NF-κB) and Tumor Necrosis Factor alpha (TNF-α) Mediated Positive Feedback Mechanism

The overall objective is to determine whether the surviving cancer cell after radiotherapy can initiate bystander response that result in clonal selection and tumor recurrence at the treatment site. We have two kinds of cell lines: human breast adenocarcinoma cells (MCF-7) and human aortic endothelism cells. First, in the MCF-7 cells we examined whether a bystander effect is initiated by TNF-a through activation of NF-kB which in-turn is triggered by therapeutic doses of radiation exposure, and also whether TNF-a and NF-kB can induce one another through positive feed back mechanisms and maintain a “memory” of the initial irradiation insult for an extended period. Second, between the MCF-7 and HAEC, we demonstrated whether radiation can induce the VEGF secreted by MCF-7, and concordant expression of the VEGFR in the bystander HAEC. MCF-7 cells were exposed to 137Cs γ ray to a total dose of 2 Gy at a dose rate of 1.06 Gy/min. Both NF-κB DNA-binding activity and the transcriptional activation measured by mobility shift assay and luciferase reporter assay, respectively showed radiation could induce nuclear translocation and transactivate κB-dependent gene expression. The activation was found to be bi-phasic, reached its maximum at 15 min (4.7-folds), decreased to basal level at 16 h, and reached a second phase maximum at 24 h (2.6-folds). Similarly, the levels of TNF-α determined by bioactivity assay revealed a 40% increase in soluble TNF-α in the culture supernatant upon 2 Gy exposure. Incubation of MCF-7 cells with either NF-κB inhibitor isohelenin or TNF-α neutralizing antibody blocked the presence of soluble TNF-α in the culture supernatant and second phase NF-κB activation, respectively. These results clearly indicated the occurrence of positive feed-back cycle between NF-κB and TNF-α through autocrine mechanism. In order to determine the occurrence of a similar mechanism in the non-irradiated bystander MCF-7 cells, supernatant from cells exposed to 2 Gy was added into the non-irradiated cells, and the NF-κB activity of non-irradiated MCF-7 cells increased by 7.2-folds. Next, to examine whether TNF-α is the paracrine signaling mediator in this bystander effect, un-irradiated MCF-7 cells, transiently transfected with NF-κB-luciferase reporter construct, was incubated with the conditioned medium from 2 Gy exposed cells in the presence or absence of TNF-α antibody. The luciferase activity showed a 60% increase in the un-irradiated MCF-7 cells when incubated with medium from irradiated cells in the absence of TNF-α antibody. Molecular analysis of specific angiogensis markers using hAngio-1 probe as a positive control was performed using ribonuclease protection assay. Of the angiogenic RNA molecules identified, the MCF-7 cells expressed VEGF and FGF-2, and the westernblot also showed the VEGF ligand and FGF-2 secreted by MCF-7 incresed by 3.4-folds and 2.6-folds separately after 2Gy exposure. We also co-cultured the irradiated MCF-7 cells with the non-irradiated HAEC, and found VEGFR2 and FGFR1 had corcondant expression increse in HAEC. This mechanism may be responsible for the stimulation of proliferative response, tumor-cell re-growth and subsequent tumor relapse at the treatment site.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 2149.

Chronic lumbar paraspinal compartment syndrome: a case report and review of the literature

A 25-year-old male weightlifter felt increasing intractable low back pain during training but denied any acute injury. The physical examination, blood parameters, radiographs and MRI were unremarkable. He had been treated non-operatively by various means, with only temporary relief. The pressures in the lumbar paraspinal compartment were abnormally high and he was treated by surgical decompression. This gave rapid relief, he returned to training, and one year later the pain had not recurred.

A novel mutation of the <i>GLI2</i> gene associated with body weight in bovine (<i>Bos taurus</i>) (Brief Report)

Abstract. During pituitary gland development, the actions of transcription factors control the development of the hormone-producing cell types. Defects in transcription factor genes, including PIT1/POU1F1, PROP1, GLI2, HESX1, LHX3, and LHX4, are associated with combined pituitary hormone deficiency (CPHD) (SAVAGE et al. 2007). Removal of the mouse GLI2 gene by targeted disruption leads to an embryonic lethal phenotype with defects in early brain and spinal cord development, which include absence of the floor plate (MATISE et al. 1998). At present, no polymorphisms of GLI2 gene have been reported in bovine. In the present paper, partial 5’ flanking region, coding region and partially introns of GLI2 were screened to detect the SNPs in Chinese cattle breeds.

Cross-geographic region differences in quality of life in women with and without vertebral fracture

SUMMARY

Not much is known about cross-geographic region differences in quality of life (QoL) in women with and without prevalent vertebral fractures (VFX). QoL differed between continents, countries, and ethnicities. The observed differences in QoL mostly appeared larger than the difference in QoL between women with or without mild to moderate VFX.

INTRODUCTION

Quality of life (QoL) is an increasingly important outcome measure in randomized controlled trials and cost-utility studies. However, not much is known about cross-geographic region differences in QoL. The objective of this study was to describe the cross-geographic region differences in QoL in women with and without mild to moderate prevalent vertebral fractures (VFX).

METHODS

The study was performed using baseline data of the bazedoxifene study. The study was carried out in 25 countries in six continents (n = 7117). QoL was assessed using the index and Visual Analogue Scale (VAS) scores of the EQ-5D, Qualeffo-41, and Women's Health Questionnaire (WHQ). VFX were assessed using semi-quantitative and quantitative morphometric methods.

RESULTS

In general, all four instruments followed more or less the same pattern. In most analyses, the reported QoL was lowest in Asia and Europe and highest in North America and Oceania. To examine the influence of ethnicity, North and South America were stratified on race. In both continents, a lower QoL was observed in Hispanic people.

CONCLUSIONS

QoL differed between continents, countries, and ethnicities. The observed differences in QoL appeared larger between most continents and countries than the difference in QoL between women with or without mild to moderate VFX.

Nanoscratch resistance of human tooth enamel treated by Nd: YAG laser irradiation

The purpose of this study was to investigate the friction behaviour of human tooth enamel irradiated by Nd:YAG laser. Forty specimens were randomly divided into four groups, and received the Nd:YAG laser irradiation with different energy densities (without irradiation; 20, 40, and 80 J/cm2). Subsequently, nano-scratch tests were conducted on the treated enamel surfaces, with progressive loads from 0.1 to 80 mN. The morphologies of the treated enamel surfaces and the scratch scars were observed via a field emission scanning electron microscope and an AMBIOS XP-2 stylus profilometer. The results indicated that the Nd:YAG laser promoted slight morphological alterations under a lower energy density (20 J/cm2), but different morphologies occurred under a higher energy density (40 and 80 J/cm2). The irradiated enamel surfaces had inferior nano-scratch resistance, and the nano-scratch resistance decreased as the energy density increased. Nd:YAG laser irradiation decreased the nano-scratch resistance of the enamel. The main damage mechanisms of the irradiated enamel under nano-scratch consisted of brittle delaminations and formation of cracks.

Molecular characterization of a distinct begomovirus infecting Allamanda cathartica in Guangdong, China

Virus isolate G10 was obtained from diseased allamanda plants showing leaf curl symptoms in Guangdong, China. The full-length nucleotide sequence of a DNA-A-like molecule of G10 was cloned and sequenced; it comprises 2755 nucleotides and has a typical begomovirus genome organization with six conserved open reading frames. When compared with the DNA-A sequences of other begomoviruses, the complete nucleotide sequence of DNA-A of G10 had the highest sequence identity (81.2%) to tomato leaf curl Guangdong virus (ToLCGuV) isolate G2. This is less than the 89% identity in the complete genome that has been defined as the threshold value for demarcation of species in the genus Begomovirus. The molecular data show that isolate G10 from allamanda in Guangdong, China is a distinct Begomovirus species, for which the name Allamanda leaf curl virus (AlLCV) is proposed.

Rapid, accurate determination of multidrug resistance in M. tuberculosis isolates and sputum using a biochip system

OBJECTIVE

To develop and evaluate a rapid biochip system for the determination of multidrug-resistant tuberculosis (MDR-TB) in Mycobacterium tuberculosis isolates and clinical sputum samples.

DESIGN

We developed a total solution-based system, including a biochip kit, apparatus for sample preparation, hybridisation, washing and data acquisition, and dedicated software for automated diagnosis. The biochip simultaneously identifies M. tuberculosis and detects the most commonly found mutations in the rpoB, katG and inhA genes. The system was assessed with 330 mycobacterial isolates and 129 sputum samples for rifampicin (RMP), and with 205 isolates and 105 sputum samples for isoniazid (INH), and then compared to DNA sequencing and conventional drug susceptibility testing (DST).

RESULTS

The entire biochip assay took 6 h. The concordance rate between the biochip assay and the DNA sequencing results was 100%. Compared to conventional DST, the concordance rates were 91.8% for isolates and 94.6% for sputum samples for RMP resistance, and 70.2% for isolates and 78.1% for sputum samples for INH resistance.

CONCLUSION

The biochip system provides a simple, rapid, reliable and accurate clinical assay for the parallel detection of M. tuberculosis and prevalent MDR-TB in a 6 h procedure, using either culture isolates or sputum samples for diagnosis.