Enhanced specific antibody productivity of calcium alginate-entrapped hybridoma is cell line-specific

In order to determine whether the enhanced specific antibody productivity ( q MAb ) of calcium alginate-entrapped hybridoma is cell line-specific, calcium alginate-entrapped hybridomas (4A2 and DB9G8) were cultivated under the condition where we had previously observed significantly enhanced q MAb of calcium alginate-entrapped S3H5/γ2bA2 hybridoma. Unlike S3H5/γ2bA2 hybridoma, neither 4A2 nor DB9G8 hybridomas showed persistently enhanced q MAb when they were entrapped in calcium alginate beads. The enhanced q MAb of entrapped 4A2 and DB9G8 hybridomas, which was 2–3 times higher than the q MAb of free-suspended cells in a control experiment, was observed only during the early stage of the culture. During the early stage of the culture, the viable cell concentration decreased probably due to cell damage during the entrapment process. As cell growth resumed, the q MAb decreased to the similar level of q MAb of free-suspended cells within 5–7 days. Thus, we conclude that the enhanced q MAb of calcium alginate-entrapped hybridomas is cell line-specific.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/42615/1/10616_2004_Article_BF00761774.pd

Quality Characteristics and Composition of the Muscle from Entire and Castrate Elk in Korea

The objective of the research was to determine the chemical composition as well as the physicochemical properties of the longissimus muscle from Korean entire and castrate elk. Twelve elk stags were raised and fed on concentrate with ad libitum hay. All animals were equally divided into castrated and non-castrated (entire) males, and slaughtered at 5 year of age. It was found that entire elk, in comparison with castrate elk, had higher content of moisture and lower content of fat (p<0.05). Compared with entire males, the castrates had lower pH and shear force values (p<0.05). However, castrates had higher L*, a*, and b* values compared with entires (p<0.05). An analysis of the fatty acid profile revealed that the muscles of entire and castrate elk had the most abundant concentrations of the following fatty acids: palmitic acid (C16:0) of the saturated fatty acid, and oleic acid (C18:1n-9) of the unsaturated fatty acid. The entire elk contains higher proportions of linoleic acid (C18:3n6), eicosenoic acid (C20:1n9), and arachidonic acid (C20:4n6) (p<0.05). Cholesterol content in elk was not affected by castration. The predominant free amino acid was glutamic acid related to umami taste. It is apparent that the castrate animals carried higher content of histidine, isoleucine, and leucine than those of the entire group (p<0.05). In this study, it was concluded that venison quality of elk is affected by castration and these results can provide fundamental information for venison production

Blocking of the IL-33/ST2 Signaling Axis by a Single-Chain Antibody Variable Fragment (scFv) Specific to IL-33 with a Defined Epitope

Interleukin 33 (IL-33) is an IL-1 family cytokine that plays a central role in immune system by regulating and initiating inflammatory responses. The binding of IL-33 to the suppressor of tumorigenicity 2 (ST2) receptor induces mitogen-activated protein kinases (MAPK) and nuclear factor &kappa;B (NF-&kappa;B) pathways, thereby leading to inflammatory cytokines production in type 2 helper T cells and type 2 innate lymphoid cells. To develop an antibody specific to IL-33 with a defined epitope, we characterized a single-chain antibody variable fragments (scFvs) clone specific to IL-33, C2_2E12, which was selected from a human synthetic library of scFvs using phage display. Affinity (Kd) of C2_2E12 was determined to be 38 nM using enzyme-linked immunosorbent assay. C2_2E12 did not show cross-reactivity toward other interleukin cytokines, including closely related IL-1 family cytokines and unrelated proteins. Mutational scanning analysis revealed that the epitope of IL-33 consisted of residues 149&ndash;158 with key residues being L150 and K151 of IL-33. Structural modeling suggested that L150 and K151 residues are important for the interaction of IL-33 with C2_2E12, implicating that C2_2E12 could block the binding of ST2 to IL-33. Pull-down and in-cell assays supported that C2_2E12 can inhibit the IL-33/ST2 signaling axis. These results suggest that the scFv clone characterized here can function as a neutralizing antibody

A mechanistic study on the destabilization of whole inactivated influenza virus vaccine in gastric environment.

Oral immunization using whole inactivated influenza virus vaccine promises an efficient vaccination strategy. While oral vaccination was hampered by harsh gastric environment, a systematic understanding about vaccine destabilization mechanisms was not performed. Here, we investigated the separate and combined effects of temperature, retention time, pH, and osmotic stress on the stability of influenza vaccine by monitoring the time-dependent morphological change using stopped-flow light scattering. When exposed to osmotic stress, clustering of vaccine particles was enhanced in an acidic medium (pH 2.0) at ≥25°C. Fluorescence spectroscopic studies showed that hyper-osmotic stress at pH 2.0 and 37°C caused a considerable increase in conformational change of antigenic proteins compared to that in acidic iso-osmotic medium. A structural integrity of membrane was destroyed upon exposure to hyper-osmotic stress, leading to irreversible morphological change, as observed by undulation in stopped-flow light scattering intensity and transmission electron microscopy. Consistent with these analyses, hemagglutination activity decreased more significantly with an increasing magnitude of hyper-osmotic stress than in the presence of the hypo- and iso-osmotic stresses. This study shows that the magnitude and direction of the osmotic gradient has a substantial impact on the stability of orally administrated influenza vaccine

Correction to: Are there differences among operators in false-negative rates of endosonography with needle aspiration for mediastinal nodal staging of non-small cell lung cancer?

Following publication of the origina

Are there differences among operators in false-negative rates of endosonography with needle aspiration for mediastinal nodal staging of non-small cell lung cancer?

Abstract Background Endosonography with needle aspiration (EBUS/EUS-NA) is recommended as the first choice for mediastinal nodal assessment in non-small cell lung cancer (NSCLC). It is important to maintain adequate negative predictive value of the procedure to avoid unnecessary additional surgical staging, but there are few studies on the influence of operator-related factors including competency on false negative results. This study aims to compare the false negative rate of individual operators and whether it changes according to accumulation of experience. Methods This is a retrospective study of NSCLC patients who were N0/N1 by EBUS/EUS-NA and confirmed by pathologic staging upon mediastinal lymph node dissection (n = 705). Patients were divided into a false negative group (finally confirmed as pN2/N3) and a true negative group (pN0/N1). False negative rates of six operators and whether these changed according to accumulated experience were analyzed. Results There were 111 (15.7%) false negative cases. False negative rates among six operators ranged from 8.3 to 21.4%; however, there were no statistical differences before and after adjustment for patient characteristics and procedure-related factors (P = 0.346 and P = 0.494, respectively). In addition, false negative rates did not change as each operator accumulated experience (P for trend = 0.632). Conclusions Our data suggest that there would be no difference in false negative rates regardless of which operator performs the procedure assuming that the operators have completed a certain period of observation and have performed procedures under the guidance of an expert