Attenuation of human lung mast cell degranulation by bronchial epithelium

BACKGROUND: Human lung mast cells (HLMC) lie in close proximity to the bronchial epithelium in asthma and adhere with high affinity to bronchial epithelial monolayers in vitro. We investigated the consequences of this adhesive interaction on HLMC activation in response to Fc epsilon RI cross-linking. METHODS: Human lung mast cells were cultured with the bronchial epithelial cell line BEAS-2B or plastic control for either 30 min or 16 h and then activated with anti-IgE. Histamine was measured by radioenzymatic assay. RESULTS: After co-culture for 30 min, IgE-dependent histamine release from HLMC was identical on both BEAS-2B and plastic. After 16 h of co-culture, there was a marked decrease in constitutive and IgE-dependent histamine release from HLMC cultured on BEAS-2B compared with those cultured on plastic or fibronectin. In contrast, the Ca(2+)/ATPase inhibitor thapsigargin produced concentration-dependent histamine release that was significantly increased on BEAS-2B compared with plastic. IgE-dependent degranulation was not significantly affected by BEAS-2B-conditioned medium. CONCLUSIONS: BEAS-2B bronchial epithelial cells attenuate IgE-dependent but not thapsigargin-induced histamine release from HLMC. The differential effect with anti-IgE compared with thapsigargin suggests that the mechanism includes interference with the proximal Fc epsilon RI signalling pathway.     

Targeted in vivo expression of IFN-gamma-inducible protein 10 induces specific antitumor activity

Although it is known that the chemoattractant effect of IFN-gamma inducible protein 10 (IP-10), a CXC chemokine (CXCL10), plays an important role in T cell-mediated antitumor immunity in vivo, whether IP-10 is involved in modulating the proliferation, survival and functional activation of tumor-specific T cells remains poorly investigated. Using an experimental mouse tumor model, we demonstrated that the in vivo growth of 4T1 tumor cells harboring IP-10 gene (4T1-IP-10) was inhibited. Mice inoculated with 4T1-IP-10 tumor cells expressing functional IP-10 survived over 90 days, whereas mice injected with control parental 4T1 cells and mice of control 4T1 cells transduced with control plasmid all succumbed to the tumor by day 38 after tumor inoculation. Mechanical analysis showed that targeted expression of IP-10 in 4T1 tumor cells markedly enhanced the infiltration of tumor-specific T cells into the 4T1-IP-10 tumor. These tumor infiltrating T lymphocytes (TILs) recruited by IP-10 were potent cytolytic killers against 4T1 tumor cells and were able to proliferate and produce high levels of IFN-gamma in response to 4T1 cells. In vivo administration of IP-10-recruited TILs induced vigorous proliferation of these TILs in situ in the 4T1-IP-10 tumor but not in the 4T1-pcDNA3 and parental 4T1 tumors. Furthermore, culture of TILs together with recombinant IP-10 significantly enhanced the proliferation and expansion of IP-10-recruited TILs in response to 4T1 tumor antigens. These results suggest that IP-10 is not only able to chemoattract tumor-specific T cells into the local tissue, but also enhance the proliferation, survival, and functional activation of these TILs, leading to the tumor regression. Thus, targeted expression of IP-10 in vivo will allow for the development of a novel approach for immunotherapy of tumor.     

Naive T-cell receptor transgenic T cells help memory B cells produce antibody

Injection of the same antigen following primary immunization induces a classic secondary response characterized by a large quantity of high-affinity antibody of an immunoglobulin G class produced more rapidly than in the initial response - the products of memory B cells are qualitatively distinct from that of the original naive B lymphocytes. Very little is known of the help provided by the CD4 T cells that stimulate memory B cells. Using antigen-specific T-cell receptor transgenic CD4 T cells (DO11.10) as a source of help, we found that naive transgenic T cells stimulated memory B cells almost as well (in terms of quantity and speed) as transgenic T cells that had been recently primed. There was a direct correlation between serum antibody levels and the number of naive transgenic T cells transferred. Using T cells from transgenic interleukin-2-deficient mice we showed that interleukin-2 was not required for a secondary response, although it was necessary for a primary response. The results suggested that the signals delivered by CD4 T cells and required by memory B cells for their activation were common to both antigen-primed and naive CD4 T cells.     

Haplotype spanning TTC12 and ANKK1, flanked by the DRD2 and NCAM1 loci, is strongly associated to nicotine dependence in two distinct American populations

Nicotine dependence (ND) is a moderately heritable trait. We ascertained a set of 1615 subjects in 632 families [319 African-American (AA) and 313 European-American (EA)] based on affected sibling pairs with cocaine or opioid dependence. Subjects were interviewed with the Semi-Structured Assessment for Drug Dependence and Alcoholism (SSADDA). Previously, we identified a modest linkage peak (LOD score =1.97) for ND in the EA part of the sample on chromosome 11q23, a region that includes the NCAM1-TTC12-ANKK1-DRD2 gene cluster. DRD2 and NCAM1 are functional candidate genes for substance dependence; the TTC12 and ANKK1 loci are not well characterized. We genotyped a set of 43 single nucleotide polymorphisms (SNPs) spanning this region, and performed family-based association and haplotype analysis. There was relatively weak evidence for association of the flanking DRD2 and NCAM1 markers to ND, but very strong evidence of association of multiple SNPs at TTC12 and ANKK1 in both populations (minimal P=0.0007 in AAs and minimal P=0.00009 in EAs), and in the pooled sample, as well as strong evidence for highly significant association of a single haplotype spanning TTC12 and ANKK1 to ND in the pooled sample (P=0.0000001). We conclude that a risk locus for ND, important both in AAs and EAs, maps to a region that spans TTC12 and ANKK1. Functional studies of these loci are warranted. These results provide additional information useful in evaluating the many earlier discrepant findings regarding association of DRD2 with substance dependence.     

Molecular epidemiology of G9 rotaviruses in Taiwan between 2000 and 2002

Since the mid-1990s, novel G9 rotaviruses have been detected in many countries, suggesting that G9 is a globally important serotype. The molecular epidemiology of G9 rotaviruses in Taiwan from 2000 to 2002 was investigated in this study. G9 rotavirus first appeared in 2000 with 4 cases and constituted 33.8% and 54.8% of the rotavirus-positive samples in 2001 and 2002, respectively. These G9 strains belonged to P[8]G9, subgroup II, and long electropherotype, except one belonged to P[4]G9, subgroup II, and short electropherotype. Nucleotide sequencing and phylogenetic analysis of 52 Taiwanese G9 rotaviruses showed that the VP7 genes shared a high degree of identity to overseas G9 rotaviruses detected after 1993 and that the VP8* portions of the VP4 genes were more closely related to those of local rotaviruses of other G types. The two P[8]G9 strains with high nucleotide identities in the VP7 and the partial VP4 genes, 01TW591 of Taiwan from 2001 and 95H115 of Japan from 1995, varied in four genes, genes 2, 3, 7, and 8, which was revealed by RNA-RNA hybridization. Representative strains for different RNA patterns were also analyzed in the partial VP2 and VP3 genes; the nucleotide identities were high between Taiwanese G9 strains and local G3 or G2 strains. These results suggested that Taiwanese G9 rotaviruses possibly had evolved through reassortment between overseas G9 strains and circulating rotaviruses of other G types.     

Ultra-thin TLDs for skin dose determination in high energy photon beams

Estimation of surface dose is very important for patients undergoing radiation therapy. In this work we investigate the dose at the surface of a water phantom and at a depth of 0.007 cm, the practical reference depth for skin as recommended by ICRP and ICRU, with ultra-thin TLDs and Monte Carlo calculations. The calculations and measurements were carried out for fields ranging from 5 x 5 cm2 to 20 x 20 cm2 for 6 MV, 10 MV and 18 MV photon beams. The variation of the surface dose with angle of incidence and field size was investigated. Also, the exit dose was computed and measured for the same fields and angles of incidence. The dose at the ICRU reference depth was computed. Good agreement (+/-5%) was achieved between measurements and calculations. The surface dose at the entrance increased with the angle of incidence and/or the field size. The exit dose decreased with the angle of incidence but it increased with field size. The dose at the surface of the patient is mostly dependent on the beam energy, modality and beam obliquity rather than the field size and field separation. By correlating TLD measurements with Monte Carlo calculations, we were able to predict the dose at the skin surface with good accuracy. Knowing the dose received at the surface of the patient can lead to prediction of skin reactions helping with the design of new treatment techniques and alternative dose fractionation schemes.     

Interfacial behaviour of strontium-containing hydroxyapatite cement with cancellous and cortical bone

The bone-bonding behaviors of various biomaterials have been extensively investigated. However, the precise mechanisms of bone bonding have not yet been clarified, and the differences in interfacial behaviors of biomaterial bonding with cancellous bone and cortical bone have not yet been understood. In this study, strontium-containing hydroxyapatite (Sr-HA) cement, in which 10% calcium ions were substituted by strontium, was performed in a rabbit hip replacement model. Six months later, the morphology and chemical composition of interfaces between Sr-HA cement with cancellous bone and cortical bone were evaluated by field emission scanning electron microscopy (FESEM) and time-of-flight secondary ion mass spectrometry (ToF-SIMS). Remarkable differences between these two interfaces were suggested both in morphology and chemical compositions. An apatite layer was found between Sr-HA cement and cancellous bone with a thickness of about 70 microm. However, only a very thin interface (about 1 microm) was formed with cortical bone. As for the cancellous bone/cement interface, high ions intensity of Ca, P, Sr, Na, and O were confirmed by FESEM-EDX and ToF-SIMS. Differences in morphology and chemical component between these two interfaces provided convincing evidences for the proposed dissolution-precipitation coupling mechanism in the formation of biological apatite.     

Expression patterns of ER-alpha, PR, HER-2/neu, and EGFR in different cell origin subtypes of high grade and non-high grade ductal carcinoma in situ

We have previously reported that high grade and non-high grade ductal carcinoma in situ (DCIS) of the breast can be subdivided into 3 cell origin subtypes (luminal, basal/stem, and null), and that high grade DCIS is more frequently associated with basal/stem cell subtypes compared to non-high grade DCIS. Here we refine the relationships between these 3 subtypes and the expression patterns of estrogen receptor-alpha (ER-alpha), progesterone receptor (PR), HER-2/neu, and epidermal growth factor receptor (ERFR) in 53 cases of non-high grade and 46 cases of high nuclear grade DCIS. Using a panel of antibodies to ER-alpha, PR, HER-2/neu, and EGFR, along with cytokeratin (CK) markers (CK5/6, CK8, CK14, CK17, and CK18), we found that all 3 cell origin subtypes can express ER-alpha and PR, and their expression is higher in non-high grade DCIS than in high grade DCIS; the expression of HER-2/neu is associated with luminal subtype only in non-high grade DCIS, but can be seen in all 3 subtypes in high grade DCIS; the expression of EGFR is low and is present only in luminal cell subtypes in both high and non-high grade DCIS. Basal/ stem cell and null cell subtypes occur in younger patients in non-high grade DCIS compared to high grade DCIS. In conclusion, the expression patterns of ER-alpha, PR, HER-2/neu, and EGFR are markedly different in different cell origin subtypes of both high grade and non-high grade DCIS, suggesting that cell origin subtypes as well as nuclear grade contribute to the biological and molecular heterogeneity of DCIS.     

Optimal Transvenous Coil Position on Active-can Single-coil ICD Defibrillation Efficacy: A Simulation Study

The implantable cardioverter defibrillator with an active can and a single coil lead is effective in treating ventricular fibrillation, but the lead placement associated with the high defibrillation efficacy is still controversial and remains largely empirical. In this study, an anatomically realistic finite difference model of the thorax was developed based on MRI cross-sectional images of a human thorax to examine the effect of transvenous coil placement on defibrillation efficacy. Four electrode configurations with the coil was placed, respectively, in the right ventricular (RV) apex, in the middle of RV cavity, along the free wall in RV, or along the septal wall in RV, were simulated and their defibrillation efficacies were evaluated based on a set of metrics including voltage defibrillation threshold, current defibrillation threshold, interelectrode impedance, potential gradient distribution uniformity, current density distribution, and myocardium damage. It was found that the optimal electrode configuration is to position the coil in the middle of the RV cavity. The results were compared with the results from a simplified thoracic model. The comparison indicates that for a given electrode configuration a simplified representation of the thorax may overestimate defibrillation efficacy.     

A new system for cultivation of human keratinocytes on acellular dermal matrix substitute with the use of human fibroblast feeder layer

To improve the proliferative potential of human keratinocytes (HK) cultured on acellular dermal matrix (ADM), HK and mitomycin C-treated human fibroblasts (MMC-HF) were seeded onto ADM to form four types of composite skin: type I, HK were seeded onto the epidermal side of ADM; type II, both HK and MMC-HF were seeded onto the epidermal side; type III, MMC-HF were preseeded onto the dermal side of ADM, and then HK were seeded onto the epidermal side, and type IV, where MMC-HF were preseeded onto both sides, and then HK were seeded onto the epidermal side. Compared with type I and III, the proliferative potential of HK of type II and IV was significantly higher on day 3, 5, 7 and 9 in vitro. In type I and III, HK grew into one layer on day 7-9, while in type II and IV keratinocytes grew into a confluent monolayer by day 4-6. The adherence to ADM of HK in types II and IV was stronger than that in type I and III. The take rate of type II and IV composite skin was also significantly higher. In conclusion, when MMC-HF and HK were cocultured on the epidermal side of ADM, MMC-HF could serve as excellent feeder cells.