MRI of magnetically labeled mesenchymal stem cells in hepatic failure model

AIM:To track intravascularly transplanted mesenchymal stem cells (MSCs) labeled with superparamagnetic iron oxide (SPIO) by using magnetic resonance imaging (MRI) in an experimental rabbit model of hepatic failure.METHODS:Human MSCs labeled with FDA-approved SPIO particles (Feridex) were transplanted via the mes-enteric vein into rabbits (n=16) with carbon tetrachloride-induced hepatic failure.Magnetic resonance (MR) examinations were performed with a 3.0 T clinical scanner immediately before and 2 h and 1,...     

Haemophilus influenzae type b carriage and novel bacterial population structure among children in urban Kathmandu, Nepal

Haemophilus influenzae type b (Hib) is a major cause of invasive bacterial infection in children that can be prevented by a vaccine, but there is still uncertainty about its relative importance in Asia. This study investigated the age-specific prevalence of Hib carriage and its molecular epidemiology in carriage and disease in Nepal. Oropharyngeal swabs were collected from children in Kathmandu, Nepal, from 3 different settings: a hospital outpatient department (OPD), schools, and children's homes. Hib was isolated using Hib antiserum agar plates, and serotyping was performed with latex agglutination. Hib isolates from children with invasive disease were obtained during active microbiological surveillance at Patan Hospital, Kathmandu, Nepal. Genotyping of disease and carriage isolates was undertaken using multilocus sequence typing (MLST). Swabs were taken from 2,195 children, including 1,311 children at an OPD, 647 children attending schools, and 237 children in homes. Overall, Hib was identified in 5.0% (110/2,195; 95% confidence interval [95% CI], 3.9% to 6.4%). MLST was performed on 108 Hib isolates from children carrying Hib isolates and 15 isolates from children with invasive disease. Thirty-one sequence types (STs) were identified, and 20 of these were novel STs. The most common ST isolates were sequence type 6 (ST6) and the novel ST722. There was marked heterogeneity among the STs from children with disease and children carrying Hib. STs identified from invasive infections were those commonly identified in carriage. This study provides evidence of Hib carriage among children in urban Nepal with genetically diverse strains prior to introduction of universal vaccination. The Hib carriage rate in Nepal was similar to the rates observed in other populations with documented high disease rates prior to vaccination, supporting implementation of Hib vaccine in Nepal in 2009.     

Parkin mediates beclin-dependent autophagic clearance of defective mitochondria and ubiquitinated Abeta in AD models

Intraneuronal amyloid-β (Aβ) may contribute to extracellular plaque deposition, the characteristic pathology of Alzheimer's disease (AD). The E3-ubiquitin ligase parkin ubiquitinates intracellular proteins and induces mitophagy. We previously demonstrated that parkin reduces Aβ levels in lentiviral models of intracellular Aβ. Here we used a triple transgenic AD (3xTg-AD) mouse, which over-expresses APP(Swe), Tau(P301L) and harbor the PS1(M146V) knock-in mutation and found that lentiviral parkin ubiquitinated intracellular Aβ in vivo, stimulated beclin-dependent molecular cascade of autophagy and facilitated clearance of vesicles containing debris and defective mitochondria. Parkin expression decreased intracellular Aβ levels and extracellular plaque deposition. Parkin expression also attenuated caspase activity, prevented mitochondrial dysfunction and oxidative stress and restored neurotransmitter synthesis. Restoration of glutamate synthesis, which was independent of glial-neuronal recycling, depended on mitochondrial activity and led to an increase in γ-amino butyric acid levels. These data indicate that parkin may be used as an alternative strategy to reduce Aβ levels and enhance autophagic clearance of Aβ-induced defects in AD. Parkin-mediated clearance of ubiquitinated Aβ may act in parallel with autophagy to clear molecular debris and defective mitochondria and restore neurotransmitter balance.     

PI3K independent activation of mTORC1 as a target in lapatinib-resistant ERBB2+ breast cancer cells

Therapies targeting the ERBB2 receptor, including the kinase inhibitor lapatinib (Tykerb, GlaxoSmithKline), have improved clinical outcome for women with ERBB2-amplified breast cancer. However, acquired resistance to lapatinib remains a significant clinical problem, and the mechanisms governing resistance remain poorly understood. We sought to define molecular alterations that confer an acquired lapatinib resistance phenotype in ER?/ERBB2+ human breast cancer cells. ERBB2-amplified SKBR3 breast cancer cells were rendered resistant to lapatinib via culture in increasing concentrations of the drug, and molecular changes associated with a resistant phenotype were interrogated using a collaborative enzyme-enhanced immunoassay platform and immunoblotting techniques for detection of phosphorylated signaling cascade proteins. Interestingly, despite apparent inactivation of the PI3K/AKT signaling pathway, resistant cells exhibited constitutive activation of mammalian target of rapamycin complex 1 (mTORC1) and were highly sensitive to mTOR inhibition with rapamycin and the dual PI3K/mTOR inhibitor NVP-BEZ235. These data demonstrate a role for downstream activation of mTORC1 in the absence of molecular alterations leading to PI3K/AKT hyperactivation as a potential mechanism of lapatinib resistance in this model of ERBB2+ breast cancer and support the rationale of combination or sequential therapy using ERBB2 and mTOR-targeting molecules to prevent or target resistance to lapatinib. Moreover, our data suggest that assessment of mTOR substrate phosphorylation (i.e., S6) may serve as a more robust biomarker to predict sensitivity to mTOR inhibitors in the context of lapatinib resistance than PI3K mutations, loss of PTEN and p-AKT levels.     

Three-week combination chemotherapy with S-1 and cisplatin as first-line treatment in patients with advanced gastric cancer: a retrospective study with 159 patients

Background

Doses and schedules of the combination of S-1 and cisplatin for the treatment of advanced gastric cancer (AGC) have not been standardized. We therefore evaluated the efficacy and feasibility of a 3-week schedule of S-1 and cisplatin in patients with AGC, as well as assessing factors prognostic of patient outcomes.

Methods

A total of 159 patients with AGC were treated with S-1 (40?mg/m² bid on days?1–14) and cisplatin (60?mg/m² IV on day?1) between January 2004 and December 2008.

Results

Median follow-up duration was 20.0?months (range, 11.4–48.5?months), during which time 129 patients (81.1%) died. Patients received a median 6 cycles of chemotherapy (range, 1–19 cycles). Among the 59 patients with measurable disease, 1 achieved a complete response (1.7%) and 24 (40.7%) had partial responses, giving an overall response rate of 42.4% (95% CI, 23.0–61.8%). The median progression-free survival (PFS) was 5.8?months (95% CI, 4.8–6.9?months), and the median overall survival (OS) was 11.3?months (95% CI, 9.6–13.0?months). Multivariate analysis showed that initial metastasis, bone metastasis, and liver metastasis were independent prognostic factors for reduced PFS, whereas poor performance status, initial metastasis, and bone metastasis were prognostic for reduced OS. Application of a previous prognostic model showed that observed PFS and OS survival curves for patients in various risk groups differed significantly (P?Conclusions A 3-week regimen of S-1 plus cisplatin was active and well tolerated as first-line treatment in patients with AGC. Disease status and bone metastasis were the most important prognostic factors.     

α1-3/4 fucosylation at Asn 241 of β-haptoglobin is a novel marker for colon cancer: a combinatorial approach for development of glycan biomarkers

Aberrant glycosylation has been observed in many types of cancer, but the mechanism of glycosylation change is still poorly understood. To elucidate relationships between glycosylation and colon cancer progression, we analyzed glycosylation status of β-haptoglobin (β-Hp) obtained from 46 cancer patients, 14 inflammatory bowel disease patients and 38 normal subjects. Aleuria aurantia lectin reactivity with cancer β-Hp was much higher than in the other two study groups. These results were confirmed by lectin blotting and microarray assay using other lectins directed to fucosyl residues. Levels of such glycans were correlated with stage of colon cancer progression. Reactivity with fucosylated glycans was eliminated by treatment with α1-3/4 fucosidase but not α1-6 fucosidase, indicating that enhanced lectin reactivity with the fucose moiety of colon cancer β-Hp is due to Fucα1-3/4GlcNAc. Moreover, site-specific glycan occupancy was determined by sequential LC/MS analysis. Mass spectrometric analysis showed that fucosylation of β-Hp was higher in colon cancer patients than in other subjects. In particular, fucosylation at Asn 241 of β-Hp in sera of colon cancer patients was clearly higher than in the other groups, and the ratio of fucosylated glycopeptides containing Asn 241 decreased greatly after treatment with α1-3/4 fucosidase. In conclusion, the level of α1-3/4 fucosyl epitope at Asn 241 of β-Hp is potentially useful as a novel marker for colon cancer.     

Tandem high-dose chemotherapy and autologous stem cell transplantation for anaplastic ependymoma in children younger than 3 years of age

The present study evaluates the feasibility and effectiveness of tandem high-dose chemotherapy and autologous stem cell transplantation (HDCT/autoSCT) in very young children with anaplastic ependymoma. We aimed both to improve survival and to avoid unacceptable late adverse effects of radiation therapy (RT) by avoiding or deferring RT until 3 years of age. Five consecutive patients younger than 3 years of age with anaplastic ependymoma were enrolled from April 2006 to November 2008. Tandem HDCT/autoSCT was given following six cycles of induction chemotherapy. RT was either not given or deferred until 3 years of age if the patient was in complete response after tandem HDCT/autoSCT. Median age at diagnosis was 16 (range 12–28) months. Four patients had significant residual tumor (>1.5 cm²) after initial surgery, and three had leptomeningeal seeding. Toxicities during induction chemotherapy and tandem HDCT/autoSCT were manageable. No tumor progressed during induction chemotherapy and tandem HDCT/autoSCT, and RT was thus avoided or deferred until 3 years of age in all patients. All patients are alive at median follow-up of 45 (range 31–62) months from diagnosis, although tumor progressed in one patient. No significant endocrine dysfunction occurred except for hypothyroidism in one patient. Cognitive function was also acceptable in all patients but one who had significant neurologic injury during surgery. Our results indicate that treatment with tandem HDCT/autoSCT is feasible in very young children with anaplastic ependymoma and may improve the survival of patients with acceptable long-term toxicity.