BST-2 expression in human hepatocytes is inducible by all three types of interferons and restricts production of hepatitis C virus

Bone marrow stromal cell antigen 2 (BST-2, also known as tetherin, CD317, or HM1.24) has recently been identified as a host restriction factor against diverse families of enveloped viruses. However, the effects of BST-2 on the life cycle of hepatitis C virus (HCV), an enveloped RNA virus, remain unclear and controversial. Here we demonstrated that human hepatocytes including Huh7.5.1 cells, primary human hepatocytes (PHHs), and HepG2 cells constitutively expressed low to moderate levels of endogenous BST-2 on the cell surface, which could be robustly up-regulated by all three types of interferons (IFNs) such as IFN-α, IFN-γ, and IFN-λ. IFN-α and IFN-γ showed a synergistic effect in induction of BST-2 expression on human hepatocytes. Over-expression of BST-2 by BST-2-expressing vector transfection or up-regulation of BST-2 by IFN stimulation markedly suppressed HCV production, whereas shRNA-mediated depletion of endogenous BST-2 significantly enhanced HCV production in infected Huh7.5.1 cells. IFN-mediated anti-HCV activity was partially but significantly diminished by shRNA-mediated knockdown of BST-2 expression, indicating that BST- 2 upregulation is directly involved in IFN-mediated inhibition of HCV production. We also found that both BST-2 and HCV core co-localized with intracellular lipid droplets (LDs), suggesting that BST-2-HCV interaction may take place around LDs as LDs constitute an important intracellular organelle for HCV assembly and replication. Taken together, our data suggest that BST-2 is a host restriction factor against HCV, and induction of BST-2 in hepatocytes could be one of the mechanisms by which current HCV standard therapy (IFN-α plus ribavirin) achieves a sustained virological response (SVR).

Artificial pneumothorax in CT-guided radioactive iodine-125 seed implantation in the treatment of mediastinal tumors

OBJECTIVE

To explore the efficacy and safety of CT-guided radioactive Iodine-125 seed implantation in treating mediastinal tumors in the thorax with artificial pneumothorax.

PATIENTS AND METHODS

Artificial pneumothorax was created using the 22 G thoracic puncture needle in 36 patients with mediastinal tumors, followed by CT-guided radioactive Iodine-125 seed implantation. An equal volume of gas was extracted after the treatment.

RESULTS

The treatment was completed in 35 patients. The tumor target volumes for the radiation treatment were not significantly different before and after the artificial pneumothorax (p = 0.265). No severe complications such as refractory pneumothorax, hemoptysis, or diffuse hemorrhage in the implantation area was observed.

CONCLUSIONS

Artificial pneumothorax can reduce the CT image interference caused by the needle tract bleeding during the radioactive Iodine-125 implantation.

Invisible bleeding from clean-shave haircuts: detection with blood specific RNA markers

BACKGROUND

'Haircut-associated bleeding' is a newly recognized entity that affects at least a quarter of African men who wear shiny clean-shave ('chiskop') haircuts.

AIM

This pilot study aimed to elucidate whether invisible haircut-associated bleeding was detectable using blood specific RNA markers (16 participants, 5 with unknown HIV status) and whether surface virus could be detected using PCR from scalp swabs (of 11 known HIV-positive participants).

METHODS

Haircuts were performed professionally and scalps examined by a dermatologist to exclude injury. Serum samples for viral loads were also collected at the same time.

RESULTS

In all, 6/16 (37%) samples tested positive (>100 relative fluorescent units) for hemoglobin beta and albumin, confirming evidence of blood; of these, only 1/11 was HIV-positive but had an undetectable serum viral load. No surface HIV was detected from any scalp samples.

CONCLUSIONS

This study confirms the entity of haircut-associated bleeding but goes further to show for the first time that invisible bleeding from clean-shave haircuts is also common. Both a high serum viral load and evidence of bleeding should ideally be present prior to surface HIV detection. Future investigations for potential HIV (and hepatitis B) transmission through clean-shave haircuts are warranted but should not delay public education for disease prevention.

Innovative estimation of survival using log-normal survival modelling on ACCENT database

Background:

The ACCENT database, with individual patient data for 20 898 patients from 18 colon cancer clinical trials, was used to support Food and Drug Administration (FDA) approval of 3-year disease-free survival as a surrogate for 5-year overall survival. We hypothesised substantive differences in survival estimation with log-normal modelling rather than standard Kaplan–Meier or Cox approaches.

Methods:

Time to relapse, disease-free survival, and overall survival were estimated using Kaplan–Meier, Cox, and log-normal approaches for male subjects aged 60–65 years, with stage III colon cancer, treated with 5-fluorouracil-based chemotherapy regimens (with 5FU), or with surgery alone (without 5FU).

Results:

Absolute differences between Cox and log-normal estimates with (without) 5FU varied by end point. The log-normal model had 5.8 (6.3)% higher estimated 3-year time to relapse than the Cox model; 4.8 (5.1)% higher 3-year disease-free survival; and 3.2 (2.2)% higher 5-year overall survival. Model checking indicated greater data support for the log-normal than the Cox model, with Cox and Kaplan–Meier estimates being more similar. All three model types indicate consistent evidence of treatment benefit on both 3-year disease-free survival and 5-year overall survival; patients allocated to 5FU had 5.0–6.7% higher 3-year disease-free survival and 5.3–6.8% higher 5-year overall survival.

Conclusion:

Substantive absolute differences between estimates of 3-year disease-free survival and 5-year overall survival with log-normal and Cox models were large enough to be clinically relevant, and warrant further consideration.

Pharmacokinetics of verapamil in diabetic rats induced by combination of high-fat diet and streptozotocin injection

The aim of this study was to investigate effects of type 2 diabetes on the pharmacokinetics of verapamil after intravenous administration. Diabetes mellitus (DM) rats were induced by combination of high-fat diet (HFD) and streptozotocin. Plasma concentrations of verapamil in DM rats, rats fed with HFD, and control (CON) rats were measured after intravenous administration of 1 mg/kg verapamil and corresponding pharmacokinetic parameters were estimated. Area under the plasma concentration in DM rats was significantly smaller than that in CON rats. In vitro microsomal study showed that intrinsic clearance of verapamil in DM rats was significantly higher than those in CON rats. Compared to CON rats, higher intrinsic clearance was also observed in HFD rats. Western blot results demonstrated higher levels of CYP3A2 in DM and HFD rats, which was in line to activity of CYP3A. All the results gave a conclusion that diabetes may enhance metabolism of verapamil in rat, and the enhancement may partly result from induction of CYP3A.

Abstract P2-06-11: Ramifications of HER2/ER/PR Guidelines from ASCO/CAP for Translational Cancer Research Using a Cohort from a Tertiary Care Centre in Ontario

Background: A transdisciplinary team from basic science, pathology, clinical and biostatistics was assembled to establish a framework with which to take novel laboratory biomarkers and targets to clinical validation. Human epidermal growth factor receptor (HER2), estrogen (ER) and progesterone (PR) receptor are of important prognostic and predictive value and drivers of systemic therapy for breast cancer (BC). As a first step, the current ASCO/CAP guidelines were used to re-assign centrally reviewed tumour specimens and compare to the clinically assigned scores for ER/PR and HER2.

Methods: With REB approval, a cohort of 62 cases of non-metastatic invasive BC with banked tumour specimens was assembled between 2005 and 2007. Clinico-pathological information for each case was retrospectively obtained from the medical file and entered into an anonymized database. Full section slides were originally stained by routine immunohistochemistry (IHC). Categorical clinical scores for ER/PR (negative-neg/weak/positive-pos) were compared to the continuous scores assigned in a blinded fashion using ASCO/CAP criteria (% pos/H-score). Categorical clinical scores obtained with duplicate IHC antibody staining of full sections for HER2 (neg/equivocal-eq/pos) were compared to those obtained from IHC assessments of triplicate 6mm cores in a tissue microarray (TMA) that were assigned to be neg/eq/pos using ASCO/CAP criteria. A senior breast pathologist adjudicated discordant specimens. Exact Fisher tests were used to compare the two sets of categorical assessments.

Results: Mean age was 43.5 years, (range 29-49). The majority of the cohort (59.7%) had N0 disease and received adjuvant chemotherapy (74.2%); 72.6% of the cohort was alive at the time of this analysis. Score means and ranges of ER/PR are displayed below. Two of 16 clinically ER neg cases (12.5%) were rescored as pos and 0/43 clinically ER pos cases were rescored as neg, P<0.0001. Two of 13 clinically PR neg cases (15.4%) were rescored as pos and 4/46 clinically PR pos cases (8.7%) were rescored as neg, (P<0.0001). HER2 status was reassessed for 51 cases, 41 of which (80%) had concordant scores (P<0.0001). Thirty-nine (76%) cases were classified as HER2 neg on TMA, 7 of which (18%) were eq on routine IHC and neg by fluorescence in situ hybridization. In routine IHC, 15.7% of tumours were eq. Four TMA cases were eq (7.8%%); with routine IHC, one of these was neg, one eq, and two were pos. Eight patients were HER2 pos in both assessments.

ER/PR scores

Conclusions: Systemic therapy recommendations could be impacted in a small but substantive number of cases by the methodology used for biomarker assessment and scoring, particularly near threshold values. This study illustrates that the scoring criteria used may be an important contributor to variability in correlative biomarker studies. Consideration should be given to routine systematic reassessment with continuous scoring for biomarker data proposed for use in correlative science studies.

Conditional regulation of cyclooxygenase-2 in tracheobronchial epithelial cells modulates pulmonary immunity

Cyclooxygenase-2 (COX-2) gene expression in the lung is induced in pathological conditions such as asthma and pneumonia; however, the exact impact of COX-2 gene expression in the airway in regulating inflammatory and immunological response in the lung is not understood. To define a physiological role of inducible COX-2 in airway epithelial cells, we developed a novel line of transgenic mice, referred to as CycloOxygenase-2 TransActivated (COTA) mice, that overexpress a COX-2 transgene in the distribution of the CC-10 promoter in response to doxycycline. In response to doxycycline treatment, COX-2 expression was increased in airway epithelium of COTA mice and whole lung tissue contained a three- to sevenfold increase in prostaglandin E(2) (PGE(2)), prostaglandin D(2) (PGD(2)) thromboxane B(2) (TXB(2)) and 6-Keto prostaglandin F(2alpha) (PGF(2alpha)) compared to wild-type and untreated COTA mice. Interestingly, primary mouse tracheal epithelial cells from COTA mice produced only PGE(2) by doxycycline-induced COX-2 activation, providing an indication of cellular specificity in terms of mediator production. In the ovalbumin model, in which doxycycline was given at the sensitization stage, there was an increase in interleukin (IL)-4 level in lung tissue from COTA mice compared to untreated COTA and wild-type mice. In addition, COTA mice that were treated with doxycycline had impaired clearance of Pseudomonas aeruginosa pneumonia compared to wild-type mice. COX-2 gene expression in airway epithelial cells has an important role in determining immunological response to infectious and allergic agents.

High prevalence of human polyomavirus JC VP1 gene sequences in pediatric malignancies

The oncogenic potential of human polyomavirus JC (JCV), a ubiquitous virus that establishes infection during early childhood in approximately 70% of the human population, is unclear. As a neurotropic virus, JCV has been implicated in pediatric central nervous system tumors and has been suggested to be a pathogenic agent in pediatric acute lymphoblastic leukemia. Recent studies have demonstrated JCV gene sequences in pediatric medulloblastomas and among patients with colorectal cancer. JCV early protein T-antigen (TAg) can form complexes with cellular regulatory proteins and thus may play a role in tumorigenesis. Since JCV is detected in B-lymphocytes, a retrospective analysis of pediatric B-cell and non-B-cell malignancies as well as other HIV-associated pediatric malignancies was conducted for the presence of JCV gene sequences. DNA was extracted from 49 pediatric malignancies, including Hodgkin disease, non-Hodgkin lymphoma, large cell lymphoma and sarcoma. Polymerase chain reaction (PCR) was conducted using JCV specific nested primer sets for the transcriptional control region (TCR), TAg, and viral capsid protein 1 (VP1) genes. Southern blot analysis and DNA sequencing were used to confirm specificity of the amplicons. A 215-bp region of the JCV VP1 gene was amplified from 26 (53%) pediatric tumor tissues. The JCV TCR and two JCV gene regions were amplified from a leiomyosarcoma specimen from an HIV-infected patient. The leiomyosarcoma specimen from the cecum harbored the archetype strain of JCV. Including the leiomyosarcoma specimen, three of five specimens sequenced were typed as JCV genotype 2. The failure to amplify JCV TCR, and TAg gene sequences in the presence of JCV VP1 gene sequence is surprising. Even though JCV TAg gene, which is similar to the SV40 TAg gene, is oncogenic in animal models, the presence of JCV gene sequences in pediatric malignancies does not prove causality. In light of the available data on the presence of JCV in normal and cancerous colon epithelial tissue and our data on amplification of JCV from the cecum of an HIV-infected pediatric patient, further studies are warranted on the role of colon epithelium in the pathogenesis of JCV infection.

Epigenetics, disease, and therapeutic interventions

Heritable changes in gene expression that do not involve coding sequence modifications are referred to as "epigenetic". Epigenetic mechanisms principally include DNA methylation and a variety of histone modifications, of which the best characterized is acetylation. DNA hypermethylation and histone hypoacetylation are hallmarks of gene silencing, while DNA hypomethylation and acetylated histones promote active transcription. Aberrant DNA methylation and histone acetylation have been linked to a number of age related disorders including cancer, autoimmune disorders and others. Since epigenetic alterations are reversible, modifying epigenetic marks contributing to disease development may provide an approach to designing new therapies. Herein we review the role of epigenetic changes in disease development, and recent advances in the therapeutic modification of epigenetic marks.

Experimental infections of pigs and mice with selected genotypes of Ascaris

Extending a previous investigation of the genotypic variability within Ascaris from humans and pigs, experimental infections of mice and pigs with selected genotypes of Ascaris were performed in the present study to explore possible host affiliation. Initial findings indicate that there is a significant difference in the ability of Ascaris eggs of genotype G1 (derived from human) and G3 (derived from pig) to infect and establish as larvae in mice and as adults in pigs, supporting the difference in the frequencies of the genotypes reported previously in natural Ascaris populations in pigs and humans in areas in China endemic for ascariasis.

Prediction of elastic properties of carbon nanotube reinforced composites

In this paper, the macroscopic elastic properties of carbon nanotube reinforced composites are evaluated through analysing the elastic deformation of a representative volume element (RVE) under various loading conditions. This RVE contains three components, i.e. a carbon nanotube, a transition layer between the nanotube and polymer matrix and an outer polymer matrix body. First, based on the force field theory of molecular mechanics and computational structural mechanics, an equivalent beam model is constructed to model the carbon nanotube effectively. The explicit relationships between the material properties of the equivalent beam element and the force constants have been set-up. Second, to describe the interaction between the nanotube and the outer polymer matrix at the level of atoms, the molecular mechanics and molecular dynamics computations have been performed to obtain the thickness and material properties of the transition layer. Moreover, an efficient three-dimensional eight-noded brick finite element is employed to model the transition layer and the outer polymer matrix. The macroscopic behaviours of the RVE can then be evaluated through the traditional finite element method. In the numerical simulations, the influences of various important factors, such as the stiffness of transition layer and geometry of RVE, on the final macroscopic material properties of composites have been investigated in detail.