Domain-based assays of individual antibody concentrations in an oligoclonal combination targeting a single protein

Quantitation of individual monoclonal antibodies (mAbs) within a combined antibody drug product is required for preclinical and clinical drug development, including pharmacokinetic (PK), toxicology, stability, and biochemical characterization studies of such drugs. We have developed an antitoxin, XOMA 3AB, consisting of three recombinant mAbs that potently neutralize the known subtypes of type A botulinum neurotoxin (BoNT/A). The three mAbs bind nonoverlapping BoNT/A epitopes with high affinity. XOMA 3AB is being developed as a treatment for botulism resulting from BoNT/A. To develop antibody-specific assays, we cloned, expressed, and purified BoNT/A domains from Escherichia coli. Each mAb bound only to its specific domain with affinity comparable to the binding to holotoxin. mAb-specific domains were used to develop an enzyme-linked immunosorbent assay (ELISA) for characterization of the integrity and binding activity of the three mAbs in the drug product. An electrochemiluminescence bridging assay that is robust to interference from components in serum was also developed, and we demonstrate that it can be used for PK assays. This type of antigen engineering to generate mAb-specific domains is a general method allowing quantitation and characterization of individual mAbs in a mAb cocktail that binds the same protein and is superior to anti-idiotype approaches.

Preclinical pharmacology of TP1, a novel potent triple reuptake inhibitor with antidepressant properties

Triple reuptake inhibitors (TRIs) that block the dopamine transporter (DAT), norepinephrine transporter (NET), and serotonin transporter (SERT) are being developed as a new class of antidepressant that may have better efficacy and fewer side effects compared with traditional antidepressants. The purpose of this study was to characterize a new chemical entity, 4-[2-(dimethylamino)-1-(1-hydroxycyclohexyl)ethyl] phenyl 4-methoxybenzoate hydrochloride (TP1). TP1 was designed as a prodrug of desvenlafaxine. Competitive radioligand binding assays were performed using cells expressing the human dopamine (DA) transporter (hDAT), the human serotonin (5-HT) transporter (hSERT), and the human norepinephrine (NE) transporter (hNET) with K(i) values for TP1 of 190 nM, 2076 nM, and 1023 nM, respectively. Uptake assays were performed with IC(50) values for TP1 of 712 nM, 521 nM, and 628 nM, respectively. TP1 (0.06 mmol/kg, orally) rapidly penetrated rat brain and hypothalamus, translated into desvenlafaxine within 1 h, and demonstrated higher bioavailability and better pharmacokinetic properties than desvenlafaxine succinate (DVS). TP1 (0.06 mmol/kg, orally) significantly increased extracellular levels of DA, NE, and 5-HT compared with baseline in the rat hypothalamus by microdialysis assay. In dose-response assays, oral administration of TP1 reduced the time of immobility in a dose-dependent manner during tail suspension test and forced swimming test (FST). This antidepressant-like effect manifests in the absence of significant increases in motor activity even at doses of up to 32 mg/kg. The ability of TP1 to inhibit the reuptake of three biogenic amines closely linked to the etiology of depression may result in a therapeutic profile different from antidepressants that inhibit the reuptake of serotonin and/or NE.

Resistin-like molecule-β is a human airway remodelling mediator

Though implicated in vascular remodelling, a role for the resistin-like molecule (RELM)-β in human airway remodelling remains unexplored. We hypothesised that RELM-β expression is increased in the airways of asthmatics and regulates airways epithelial cell function. Expression of RELM-β in the bronchial mucosa and its concentrations in bronchoalveolar lavage (BAL) fluid from asthmatics and controls were measured by immunohistochemistry and ELISA, respectively. Proliferation assays, Western blotting, ELISA and real-time PCR were employed to detect effects of RELM-β on airways epithelial cells. RELM-β expression was increased in the bronchial mucosa and BAL fluid of asthmatics compared with controls. In the asthmatics, the numbers of mucosal RELM-β+ cells correlated inversely with forced expiratory volume in 1 s (r=-0.531, p=0.016), while the numbers of epithelial RELM-β+ cells correlated positively with those of mucin (MUC)5AC+ cells. In vitro, interleukin-13 enhanced RELM-β expression by primary human airways epithelial cells, while RELM-β itself acted on these cells to induce proliferation, expression of MUC5AC, extracellular signal-regulated kinase (ERK)/mitogen-activated protein kinase (MAPK)-phosphatidylinositol 3-kinase (PI3K)/Akt phosphorylation and elevated expression of transforming growth factor-β2, epidermal growth factor and vascular endothelial growth factor. RELM-β has the potential to contribute to airway remodelling in diseases such as asthma by acting on epithelial cells to increase proliferation, mucin and growth factor production, at least partly via ERK/MAPK-PI3K/Akt signalling pathways.

Pituicytoma: case report and literature review

Pituicytoma is a rare primary tumour of the neurohypophysis or infundibulum, which masquerades as a pituitary adenoma. We present a pituicytoma case in a 45-year-old female presenting as a focal lesion of the neurohypophysis. This case report reviews the clinical, neuroimaging and histopathological features of this rare tumour in order to understand it better.

CvhSlicer: an interactive cross-sectional anatomy navigation system based on high-resolution Chinese visible human data

We introduce the design and implementation of an interactive system for the navigation of cross-sectional anatomy based on Chinese Visible Human (CVH) data, named CvhSlicer. This system is featured in real-time computation and rendering of high-resolution anatomical images on standard personal computers (PCs) equipped with commodity Graphics Processing Units (GPUs). In order to load the whole-body dataset into the memory of a common PC, several processing steps are first applied to compress the huge CVH data. Thereafter, an adaptive CPU-GPU balancing scheme is performed to dynamically distribute rendering tasks among CPU and GPU based on parameters of computing resources. Experimental results demonstrate that our system can achieve real-time performance and has great potential to be used in anatomy education.

Outcomes comparison of 5 coated cardiopulmonary bypass circuits versus an uncoated control group of patients undergoing cardiac surgery

Attenuated inflammatory response and decreased platelet activation have been claimed repeatedly when biocompatible circuits are used for cardiopulmonary bypass. We evaluated five Health Canada approved biocompatible circuit coatings (BCC) against an un-coated control group to determine their effectiveness in improving post-operative outcomes.

Patients were assigned to the Control group or one of the 5 coated circuit groups: 40 Control; 33 Trillium; 32 Phisio; 34 Bioline; 33 X; and 11 GBS. Measured outcomes included: ventilator time; ICU time; post-operative chest tube drainage and transfusion volume; high sensitivity C-reactive protein (hsCRP); tau protein; and pre- and 72-hour post-operative anti-saccadic eye movement test comparisons.

Results: 183 patients were enlisted into the study. One arm of the study (GBS) was abandoned after 11 patients on account of inconsistent pressure excursions within the oxygenator and the excessive consumption of platelets necessitating transfusion. Patients in the X-coated group had significantly longer ventilator and intensive care unit (ICU) time compared to the three remaining coated circuit study groups. Though not significant, patients in the X group also demonstrated the highest post-operative chest tube losses, the most platelet transfusions, the highest tau protein levels and the lowest post-operative anti-saccadic eye movement test (ASEMT) results compared to the three remaining coated groups. The patients in the Trillium, Bioline and Phisio groups showed an improvement in ventilator and ICU time relative to the Control group. The diabetic patients in the Trillium, Bioline and Phisio groups showed an improvement in bleeding relative to the diabetic patients in the Control group.

Conclusion: We compared all 5 coated circuits approved for clinical use in Canada against an uncoated control circuit. Three of the 5 coated circuits (Trillium, Phisio and Bioline BCC) were found to improve ventilator and ICU time compared to Control. Further studies are indicated to validate these results and their impact upon approval criteria, purchasing choices and safe clinical practice, especially as applied to higher risk diabetic patients.

Early production of thymic stromal lymphopoietin precedes infiltration of dendritic cells expressing its receptor in allergen-induced late phase cutaneous responses in atopic subjects

BACKGROUND

Thymic stromal lymphopoietin (TSLP) is an interleukin (IL)-7-like cytokine that triggers dendritic cell-mediated T helper (Th)2 inflammatory responses through a receptor consisting of a heterodimer of the IL-7 receptor alpha (IL-7Ralpha) chain and the TSLP receptor (TSLPR), which resembles the cytokine receptor common gamma chain. Dendritic cells activated by TSLP prime development of CD4(+) T cells into Th2 cells contributing to the pathogenesis of allergic inflammation. We hypothesized that allergen exposure induces expression of TSLP and results in recruitment of TSLPR bearing cells in the cutaneous allergen-induced late-phase reaction (LPR) in atopic subjects.

METHODS

Skin biopsies were obtained from atopic subjects (n = 9) at various times after cutaneous allergen challenge. In situ hybridization and immunohistochemistry were used to determine TSLP mRNA expression and to measure infiltration of TSLPR(+) DC in skin LPR. RT-PCR and flow cytometry were employed to analyse TSLPR expression on isolated blood DC.

RESULTS

Allergen-induced skin TSLP expression occurred as early as 1 h after allergen challenge, whereas TSLPR(+) and CD11c(+) cells infiltrated relatively late (24-48 h). The majority of TSLPR(+) cells were DC co-expressing blood DC antigen-1 (BDCA-1) or BDCA-2. Freshly isolated blood DC expressed both TSLPR and IL-7Ralpha chains. Maturation and stimulation with TSLP or polyriboinosinic-polyribocytidylic acid in vitro upregulated the expression of both TSLPR and IL-7Ralpha chains in DC but not in chemoattractant receptor-homologous molecule expressed on Th2 cells(+) CD4(+) T cells.

CONCLUSION

The data suggest that TSLP plays a role in augmenting, through DC recruitment and activation, the development of Th2-type T cells in allergic inflammation.

Validation of the simplified Chinese version of EORTC QLQ-C30 from the measurements of five types of inpatients with cancer

BACKGROUND

European Organization for Research and Treatment quality of life (QOL) questionnaire (QLQ-C30) has been used frequently and many language versions have been developed, including the simplified Chinese version. It is important to study psychometric properties of the simplified Chinese version from the clinical standpoint.

PATIENTS AND METHODS

The simplified Chinese version of the QLQ-C30 was used in a longitudinal study of 600 patients with five types of cancer: lung, breast, head and neck, colorectal, and stomach. The psychometric properties of the scale were evaluated by indicators of validity and reliability coefficients such as Cronbach's alpha and Pearson's correlation coefficient r, standardized response mean (SRM), correlational analysis, t-tests, and structural equation models.

RESULTS

Correlation and structural equation model analyses confirmed good construct validity with root mean square error of approximation 0.054, standardized root mean square residual 0.037, non-normed fit index 0.972, and comparative fit index 0.980. The alpha coefficients for all domains are >0.7 except for cognitive functioning (0.49). The test-retest reliability coefficients for most domains are >0.80 except for appetite loss (0.77) and diarrhea (0.75). The QOL score changes after treatments were of statistical significance with higher or moderate SRM in most domains.

CONCLUSION

The simplified Chinese version of QLQ-C30 has good validity, reliability, and responsiveness and can be used to measure QOL for Chinese cancer patients.

DOT in rural China: experience from a case study in Shandong Province, China

SETTING

Four counties at varying levels of economic development in Shandong Province were sampled. All offered tuberculosis (TB) directly observed treatment (DOT) treatment at the County TB Dispensary (CTBD).

OBJECTIVE

To empirically document how DOT and home visits were implemented in rural China and to shed light on whether DOT is one of the key elements through which China achieves its high cure rates for TB.

DESIGN

A total of 404 rural smear-positive TB patients registered in the CTBDs were interviewed face-to-face with structured questionnaires. Village doctors and key informants from the CTBDs were also interviewed.

RESULTS

The majority of TB patients in rural areas do not receive DOT from village doctors and rarely get support, such as visits as required, from the CTBDs or township health providers in Shandong, China.

CONCLUSION

The lack of DOT in Shandong does not have a negative effect on TB treatment outcomes. Given that the DOTS strategy is still the core measure of TB control in China, implementation of other programme elements apart from DOT is necessary to ensure a successful TB treatment programme.

45 EFFECT OF TRICHOSTATIN A TREATMENT ON THE TERM DEVELOPMENT OF SOMATIC CELL NUCLEAR TRANSFER RABBIT EMBRYOS

The efficiency of somatic cell nuclear transfer (SCNT) is low in the rabbit. So far, there have been few live births reported and most clones died within the first 3 weeks after birth. It has been shown that treatment with trichostatin A (TSA), a histone deacetylase inhibitor, improved cloning efficiency in cattle (Enright et al. 2003 Biol. Reprod. 69, 896–901) and mice (Kishigami et al. 2006 Biochem. Biophys. Res. Commun. 340, 183–189; Rybouchkin et al. 2006 Biol. Reprod. 74, 1083–1089). Although a recent report indicated that TSA treatment could increase the cell number of rabbit SCNT blastocysts (Xu et al. 2007 Reprod. Fertil. Dev. 19, 165), term development of TSA-treated cloned embryos in this species has not been reported. In this study we investigated the effect of TSA treatment on the term development of somatic cell nuclear transfer (SCNT) rabbit embryos. The oocytes and cumulus cells were collected from superovulated Hycole hybrid rabbits. After staining with Hoechst 33342 and locating following 1–2 s of UV illumination, the nuclei of oocytes were removed by micromanipulation, A cumulus cell was then inserted into the perivitelline space and fused with the cytoplast with three 20 μs 3.2 kV cm–1 DC pulses. Fused embryos were activated using the same electrical parameters 1 h later, treated with 2 mm 6-dimethylaminopurine and 5 μg mL–1 cycloheximide for 1 h, and then subsequently cultured in Earles Balanced Salt Solution (EBSS) with or without 5 nm TSA for 10 h. The embryos were then cultured in EBSS either overnight (before ET) or for 4.5 days. Embryos were transferred at the 2- to 4-cell stages to the recipients 22 h after collection of the oocytes from the donors. Caesarean sections were performed on Day 30 post-ET. In vitro developmental data (Table 1) showed no differences in the cleavage, blastocyst rates, and blastocyst cell numbers between the TSA-treated or untreated cloned embryos. After ET in the TSA group, one pregnant female delivered 7 live and 3 stillborn pups, but all of the live pups died within 1 h to 19 days later. In the untreated group, one pregnant female gave birth to 2 live and 1 stillborn pup. One pup died within 1 h after birth; the other survived (2.5 months old when this abstract was submitted). In conclusion, the results indicate that TSA treatment has a limited effect on in vitro development of SCNT embryos, and both TSA-treated and untreated SCNT clones can develop to term in rabbit. The effects of TSA treatment on the health of clones need further investigation. Table 1. In vitro and in vivo development of SCNT rabbit embryos with or without TSA treatment This study was supported by Wellcome Trust (Grant No. 070246), EU FP6 (MEXT-CT-2003-509582, MRTN-CT-2006-035468), and Chinese-Hungarian Bilateral projects (TET CHN-28/04, CHN-41/05).