Viral disruption of olfactory progenitors is exacerbated in allergic mice

Upper airway viral infection in patients with airway allergy often exacerbates olfactory dysfunction, but the mechanism for this exacerbation remains unclear. Here, we examined the effects of respiratory syncytial virus (RSV) infection, in the presence or absence of airway allergy, on olfactory receptor neurons (ORNs) and their progenitors in mice. Immunohistological analyses revealed that cockroach allergen (CRA)-induced airway allergy alone did not affect the number of OMP(+) mature ORNs and SOX2(+) ORN progenitors. Intranasal RSV line 19 infection in allergy-free mice resulted in a transient decrease in SOX2(+) ORN progenitors without affecting OMP(+) ORNs. In contrast, the RSV-induced decrease in SOX2(+) ORN progenitors was exacerbated and prolonged in allergic mice, which resulted in eventual loss of OMP(+) ORNs. In the allergic mice, reduction of RSV in the olfactory epithelium was delayed as compared with allergy-free mice. These results suggest that ORN progenitors were impaired by RSV infection and that airway allergy exacerbated damage to ORN progenitors by reducing viral clearance.

Upregulation of non-β cell-derived vascular endothelial growth factor A increases small clusters of insulin-producing cells in the pancreas

Pancreatic β cell-derived vascular endothelial growth factor A (VEGF-A) contributes to normal β cell function. We therefore hypothesized that non-β cell-derived VEGF-A may affect its properties in adult mice.We generated transgenic mice expressing human VEGF-A (hVEGF-A) in a visceral smooth muscle cell (SMC)-dominant manner under the control of the transgelin (Tagln/SM22α) promoter via a tamoxifen-induced Cre/loxP recombination system (SM-CreER(T2)/hVEGF mice).SM-CreER(T2)/hVEGF mice received tamoxifen orally followed by microscopic examination of their pancreas 4 weeks after the hVEGF-A induction. The number of clusters of insulin-producing cells (IPCs) in islets, pancreatic ducts, and individual IPCs were counted.The number of small IPC clusters (100-215 μm(2)) in the pancreas increased significantly in SM-CreER(T2)/hVEGF mice compared with SM-CreER(T2)(Ki) mice (473 out of 1 992 counts vs. 199 out of 976 counts, p<0.05), although total IPC area and the number of pancreatic duct IPCs, in proportion to exocrine area, were similar between the 2 groups. Although most small IPC clusters observed in SM-CreER(T2)/hVEGF mice were not accompanied by α and/or δ cells, some were attached to a single or a few α cells. An STZ-induced diabetic state in SM-CreER(T2)/hVEGF mice was slightly ameliorated, with only one point of significance 12 weeks after STZ administration, compared with SM-CreER(T2)(Ki) mice.Upregulation of non-β cell-derived VEGF-A may alter the composition of pancreatic IPCs by increasing the number of small IPC clusters. These findings provide new information on the role of non-β cell-derived VEGF-A to IPC regeneration and insulin production.

An analysis of the best method for evaluating anteversion of the acetabular component after total hip replacement on plain radiographs

Several radiological methods of measuring anteversion of the acetabular component after total hip replacement (THR) have been described. These studies used different definitions and reference planes to compare methods, allowing for misinterpretation of the results. We compared the reliability and accuracy of five current methods using plain radiographs (those of Lewinnek, Widmer, Liaw, Pradhan, and Woo and Morrey) with CT measurements, using the same definition and reference plane. We retrospectively studied the plain radiographs and CT scans in 84 hips of 84 patients who underwent primary THR. Intra- and inter-observer reliability were high for the measurement of inclination and anteversion with all methods on plain radiographs and CT scans. The measurements of inclination on plain radiographs were similar to the measurements using CT (p = 0.043). The mean difference between CT measurements was 0.6° (-5.9° to 6.8°).

Measurements using Widmer’s method were the most similar to those using CT (p = 0.088), with a mean difference between CT measurements of -0.9° (-10.4° to 9.1°), whereas the other four methods differed significantly from those using CT (p < 0.001).

This study has shown that Widmer’s method is the best for evaluating the anteversion of the acetabular component on plain radiographs.

Cite this article: Bone Joint J 2014; 96-B:597–603.

The pharmacokinetics and safety profiles of belimumab after single subcutaneous and intravenous doses in healthy Japanese volunteers

WHAT IS KNOWN AND OBJECTIVES

Belimumab is a recombinant human monoclonal antibody that binds and antagonizes the biological activity of soluble B-lymphocyte stimulator (BLyS) protein. BLyS appears to play a role in the pathogenesis of systemic lupus erythematosus, and the biological profile of belimumab suggests that it may have a therapeutic benefit in the treatment for the disease. In this healthy Japanese subjects study, we investigated the pharmacokinetics and safety of a single subcutaneous and intravenous injection of belimumab administered as a 200 mg/mL liquid formulation.

METHODS

This was an open-label, randomized, parallel-group, single-dose study in healthy Japanese subjects. Each subject received a single intravenous infusion or a subcutaneous injection of 200 mg belimumab. The pharmacokinetic parameters and safety parameters including local tolerance (injection site), biomarkers, immunogenicity and adverse events were evaluated up to 70 days post-dosing.

RESULTS

After a single intravenous or a subcutaneous administration of 200 mg belimumab, all 16 subjects completed the study. There were no serious adverse events or adverse events related to injection site reactions. All seven adverse events were considered mild or moderate in intensity and deemed unrelated to belimumab except for cellulitis following intravenous administration. The bioavailability of the single subcutaneous dose of 200 mg belimumab in the subjects was estimated to be 77·5%. Time to the maximum serum concentration after subcutaneous injection was 6·5 days (median). The geometric mean terminal half-life was comparable between the two administration routes (17·7 days intravenous and 15·9 days subcutaneous). Serum immunoglobulin G level decreased slightly after each treatment. No subjects were found to produce antibelimumab antibodies.

WHAT IS NEW AND CONCLUSIONS

A favourable absolute bioavailability in healthy Japanese subjects was seen following a subcutaneous injection of 200 mg belimumab. Considering the intersubject variability, exposures were consistent with those previously observed in healthy non-Japanese subjects. Safety and biomarker data were also consistent with previous non-Japanese clinical studies.