The blocking activity of birch pollen-specific immunotherapy-induced IgG4 is not qualitatively superior to that of other IgG subclasses

Allergen-specific IgG antibodies induced by specific immunotherapy (SIT) interfere with the allergen-IgE interaction, and act as blocking antibodies in vitro. It has been hypothesised that IgG4, as opposed to other IgG subclasses, is particularly important in this function, which may play a role for the clinical efficacy of SIT. In this study, fractionated serum samples from 14 SIT-treated birch pollen allergic individuals enabled determination of the inhibitory capacity of IgG4 alone versus non-IgG4 IgG. Allergen-binding activities of IgG and the IgG-mediated inhibition of allergen binding to autologous IgE were detected using 125I-labelled rBet v 1.2801, a recombinant variant of the major allergen of Betula verrucosa pollen. Results show that IgG4-depletion resulted in equivalent reductions in binding and blocking activities. In contrast, a significant but less than two-fold higher relative blocking activity was found in the purified IgG4 fraction. There was no significant difference in the binding avidities (1/K(d)) measured in the two IgG fractions. Thus, it appears that SIT-induced specific IgG4 contributes to the IgG blocking of allergen binding to IgE in a simple quantitative manner and not by a particular intrinsic blocking activity.     

Adaptation of the gait initiation process for stepping on to a new level using a single step

During the gait initiation in level walking, the anticipatory postural adjustments (APA) which precede heel off consist of a forward fall of the whole body and their duration depends on the intended gait velocity related to the step length. The present study examines the adaptation of the gait initiation process for stepping on to a new level. Five subjects performed a single step at natural speed in five experimental conditions. The first condition (C1) was a level walking task whereas the other (stair) conditions required stepping on to a new level (from 8 to 32 cm). The horizontal step length was the same under all conditions. Results showed that the center of mass (CM) forward velocity at the end of the APA, and also until foot contact of the leading limb, decreased from C1 to the stair conditions whereas the peak of forward velocity was similar under all conditions. Moreover, the CM forward displacement up to foot contact was smaller in the stair conditions than in C1. These results suggest the use of a sequential mode of control for the organization of the CM forward dynamics during the stair conditions. This adaptation of the gait initiation process for stepping up is examined mainly from the result that the majority of body lift, which occurred only from the beginning of the double-stance phase, involved a larger CM forward translation than in level walking. As the horizontal step length was the same in all conditions, it can be suggested that the CNS had to reduce the CM forward displacement up to foot contact in the stair conditions, in order to take into account the subsequent greater forward translation.     

Lysine-fixable dye tracing of exocytosis shows F-actin coating is a step that follows granule fusion in pancreatic acinar cells

Exocytosis, the fusion of a vesicle with the plasma membrane, involves a complex cascade of cellular events. We set out to develop a method to identify changes in the distribution of proteins associated with exocytotic events in secretory epithelial cells. Our model system, the mouse pancreatic acinar cell, contains many hundreds of secretory vesicles (zymogen granules). Cell stimulation with low, physiological concentrations of agonist leads to the exocytosis of only a few granules. Once the preparation is fixed it is impossible with light microscopy to determine which of the granules have fused. In our method we use a derivative of a fluorescent dye, lysine-fixable Texas Red dextran dye, where the dye has been conjugated to dextran containing lysine residues. This dye enters the zymogen granule on the opening of the fusion pore at the time of exocytosis. This dye can then be fixed with paraformaldehyde and the preparation used for conventional immunocytochemistry methods. In demonstrating the utility of the method we carried out experiments where we fixed the cells and counterstained F-actin with phalloidin. The results show that F-actin coating is associated specifically with dye-filled granules and therefore is a step that follows exocytosis.     

Isolation and characterization of a mutant Chinese hamster ovary cell line that is resistant to Chlamydia trachomatis infection at a novel step in the attachment process

Host factors involved in Chlamydia trachomatis pathogenesis were investigated by random chemical mutagenesis of Chinese hamster ovary (CHO-K1) cells followed by selection for clones resistant to chlamydial infection. A clonal mutant cell line, D4.1-3, refractory to infection by the C. trachomatis L2 serovar was isolated. The D4.1-3 cell line appears to be lacking in a previously undescribed temperature-dependent and heparin-resistant binding step that occurs subsequent to engagement of cell surface heparan sulfate by L2 elementary bodies. This novel binding step differentiates the lymphogranuloma venereum (LGV) serovar from other serovars and may contribute the different pathologies associated with LGV and non-LGV strains.     

Coronary balloon angioplasty: a technique that is here to stay

In this article, developments in the technique of percutaneous transluminal coronary angioplasty (PTCA) since its introduction in 1977 as well as current trends and likely future directions of the technique are outlined. Over the last 6 or 7 years, there has been a dramatic widening of the applications PTCA to include patients with complex anatomic lesions and adverse clinical features. Despite the large percentage of such difficult cases currently presenting for PTCA, an initial success rate in excess of 90% is achieved. Increased operator experience and continuing refinements in angioplasty technology are important factors in this continuing success of PTCA. Early restenosis remains the major drawback of the technique; this complication is usually treated by repeat PTCA. Available information indicates that the long-term outcome of patients after successful PTCA is excellent, with a low incidence of late restenosis and progression of disease. The relative efficacy of PTCA and coronary bypass surgery in patients with multivessel disease is, at present, uncertain.     

The DEK oncoprotein is a Su(var) that is essential to heterochromatin integrity

Heterochromatin integrity is crucial for genome stability and regulation of gene expression, but the factors involved in mammalian heterochromatin biology are only incompletely understood. Here we identify the oncoprotein DEK, an abundant nuclear protein with a previously enigmatic in vivo function, as a Suppressor of Variegation [Su(var)] that is crucial to global heterochromatin integrity. We show that DEK interacts directly with Heterochromatin Protein 1 α (HP1α) and markedly enhances its binding to trimethylated H3K9 (H3K9me3), which is key for maintaining heterochromatic regions. Loss of Dek in Drosophila leads to a Su(var) phenotype and global reduction in heterochromatin. Thus, these findings show that DEK is a key factor in maintaining the balance between heterochromatin and euchromatin in vivo.     

Complex glandular pattern is an aggressive morphology that predicts poor prognosis of pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive malignant neoplasm with various morphologies. Recognition of histological patterns that can predict prognosis is important in pathological examination. Recently, the complex glandular pattern was defined as a morphology associating the poor prognosis in lung adenocarcinoma. We investigated the significance of the complex glandular pattern in PDAC by performing a retrospective analysis. Among 240 consecutive cases of conventional PDACs, 21 cases in which complex glandular pattern constituted >50 % of the total tumor volume (CG-PDACs) were identified. The prevalence of CG-PDAC was 8.8 % among all preoperative therapy-naïve and surgically resected conventional PDACs. Compared to the control PDACs (n = 95), the CG-PDACs were characterized by significantly higher prevalence of small- to medium-sized artery invasion (71.4 % vs. 14.7 %, p < 0.0001), intratumoral necrosis (59.1 % vs. 16.8 %, p < 0.0001), tumor budding (mean: 15.5 vs. 12.5 per 0.785 mm², p = 0.04), significantly higher Ki67 proliferative index (mean: 75.0 % vs. 54.7 %, p < 0.0001), and the HNF1α−/KRT81+ (quasi-mesenchymal) immunophenotype (42.9 % vs. 19.0 %, p = 0.004). In Kaplan-Meier analyses, the CG-PDAC patients achieved significantly worse disease-free survival (DFS) and overall survival (OS) compared to the control PDAC patients; the respective median DFS and OS were 6.3 and 17.7 months for CG-PDACs, and 22.6 and 52.8 months for control PDACs. A multivariate Cox regression analysis showed that predominance of complex glandular pattern was an independent prognostic factor (hazard ratio: 2.95; 95 % confidence interval: 1.46–5.98; p = 0.003). Our results provide new insights into the complex glandular pattern in conventional PDACs as a novel and potentially useful prognostic factor.     

B-cell epitope spreading is a critical step for the switch from C-protein-induced myocarditis to dilated cardiomyopathy

Repeated inflammation in the heart is one of the initiation factors of dilated cardiomyopathy (DCM). In a previous study, we established a new animal model for DCM by immunization of rats with recombinant cardiac C-protein fragment 2 (CC2). The present study examined factors involved in the development of DCM. Analysis using overlapping peptides revealed that the major carditogenic epitope resides only in the residue 615-647 [CC2 peptide 12 (CC2P12)]. However, immunization with CC2P12 induced moderate inflammation without subsequent DCM. CDR3 spectratyping analysis of the T-cell repertoire demonstrated that Vbeta4-positive T cells were preferentially expanded in both CC2- and CC2P12-immunized rats. Although there was no significant difference in the T-cell characteristics, examinations of the B-cell epitope revealed that marked epitope spreading occurred in CC2-immunized but not CC2P12-immunized rats from 4 weeks after immunization. Consistent with this finding, immunization with CC2P12 and simultaneous transfer of anti-peptide antisera induced significantly more severe inflammation and fibrosis than CC2P12 immunization alone. However, the transfer of the antisera without CC2P12 immunization did not induce any pathology. These findings suggest that T-cell activation and B-cell epitope spreading in the CC2 molecule is a key step for the switch from myocarditis to the development of DCM.     

Locomotion of monocytes on endothelium is a critical step during extravasation

Monocytes, like all leukocytes, undergo a series of sequential steps during extravasation from blood into tissues: tethering, rolling, adhesion and diapedesis. We have discovered an essential step, which we call locomotion, in which the monocyte moves from a site of firm adhesion to the nearest junction to begin diapedesis. Blocking CD11a-CD18 and CD11b-CD18 on human monocytes or adhesion molecules ICAM-1 and ICAM-2 on endothelial cells prevented the monocytes from reaching junctions. The blocked monocytes spun in circles as if they were unable to direct their movement despite being able to adhere and polarize normally. This step fills a gap in the paradigm of extravasation as a multistep process.     

Robotic assistance that encourages the generation of stepping rather than fully assisting movements is best for learning to step in spinally contused rats

Robotic devices have been developed to assist body weight-supported treadmill training (BWSTT) in individuals with spinal cord injuries (SCIs) and stroke. Recent findings have raised questions about the effectiveness of robotic training that fully assisted (FA) stepping movements. The purpose of this study was to examine whether assist-as-needed robotic (AAN) training was better than FA movements in rats with incomplete SCI. Electromyography (EMG) electrodes were implanted in the tibialis anterior and medial gastrocnemius hindlimb muscles of 14 adult rats. Afterward, the rats received a severe midthoracic spinal cord contusion and began daily weight-supported treadmill training 1 wk later using a rodent robotic system. During training, assistive forces were applied to the ankle when it strayed from a desired stepping trajectory. The amount of force was proportional to the magnitude of the movement error, and this was multiplied by either a high or low scale factor to implement the FA (n = 7) or AAN algorithms (n = 7), respectively. Thus FA training drove the ankle along the desired trajectory, whereas greater variety in ankle movements occurred during AAN training. After 4 wk of training, locomotor recovery was greater in the AAN group, as demonstrated by the ability to generate steps without assistance, more normal-like kinematic characteristics, and greater EMG activity. The findings suggested that flexible robotic assistance facilitated learning to step after a SCI. These findings support the rationale for the use of AAN robotic training algorithms in human robotic-assisted BWSTT.     

Innate refractoriness of the Lewis rat to toxoplasmosis is a dominant trait that is intrinsic to bone marrow-derived cells

Toxoplasmosis is a ubiquitous parasitic infection causing a wide spectrum of diseases. It is usually asymptomatic but can lead to severe ocular and neurological disorders. Among the small-animal models available to study factors that determine susceptibility to toxoplasmosis, the rat appears to be rather similar to humans, particularly in terms of resistance to acute infection. Here, we demonstrate that the Lewis (LEW) rat strain displays an unexpected refractoriness to Toxoplasma infection. Complete resistance was assessed by both negative anti-Toxoplasma serology and lack of detection of the parasite during the course of infection. In this model, sex, age, major histocompatibility complex, and inoculum size had no effect on resistance. Interestingly, progeny from F(1) hybrid crosses between Fischer (F344) or Brown Norway susceptible rats and LEW resistant rats were also fully resistant, showing a dominant effect of the gene or set of genes. Furthermore, resistance of the LEW rat was shown to be dependent on hematopoietic cells and partially abrogated by neutralization of endogenous gamma interferon. To our knowledge, this is the first observation of a rodent strain that is refractory to Toxoplasma infection. This model is therefore an attractive and powerful tool to dissect host genetic factors involved in susceptibility to toxoplasmosis.     

Socio-economic factors that predict psychiatric admissions at a local level

BACKGROUND: The aim of the study was to confirm the predictive relationship between socio-economic factors and psychiatric admissions at a fine grain geographical level. The strength of association was compared with those of other studies that have looked at separate diagnostic groups. METHOD: Psychiatric admissions were from electoral wards of the County of South Glamorgan, which encompasses the capital city of Wales, Cardiff. Standardized psychiatric admission ratios (SAR) for different diagnostic groups were calculated for a 5-year period. The ecological association with deprivation indices and with single variables at the level of electoral ward was examined. Of a total of 15266 psychiatric admissions, 11296 were analysed. RESULTS: Psychiatric morbidity, reflected in SAR was inversely related to socio-economic deprivation for both sexes. This applied to all diagnostic groups except organic disorders. The relationship was most marked for schizophrenia, delusional disorders and substance abuse, closely followed by personality disorders, and less for affective and neurotic disorders. Little difference existed between three composite indices of deprivation (Carstairs, Jarman, Townsend), but the marginally best predictor was that designed by Jarman. However, low rates of car ownership and high unemployment were as good at predicting SAR as any of the compound indices. CONCLUSION: Socio-economic factors account for almost 50 % of the variance in psychiatric admission rates between electoral wards. The degree of association between psychiatric morbidity and deprivation varies between diagnostic groups, arguing against a common factor linking deprivation and psychiatric admissions generally. Frequently updated unemployment figures provide nearly as useful and more immediate information than 10-yearly Census data used to calculate the deprivation indices. These figures may be used for needs assessment and targeting resources at a local level.     

Estimating and validating disability-adjusted life years at the global level: a methodological framework for cancer

ABSTRACT: BACKGROUND: Disability-adjusted life years (DALYs) link data on disease occurrence to health outcomes, and they are a useful aid in establishing country-specific agendas regarding cancer control. The variables required to compute DALYs are however multiple and not readily available in many countries. We propose a methodology that derives global DALYs and validate variables and DALYs based on data from various cancer registries. METHODS: We estimated DALYs for four countries (Norway, Bulgaria, India and Uganda) within each category of the human development index (HDI). The following sources (indicators) were used: Globocan2008 (incidence and mortality), various cancer registries (proportion cured, proportion treated and duration of disease), treatment guidelines (duration of treatment), specific burden of disease studies (sequelae and disability weights), alongside expert opinion. We obtained country-specific population estimates and identified resource levels using the HDI, DALYs are computed as the sum of years of life lost and years lived with disabilities. RESULTS: Using mortality:incidence ratios to estimate country-specific survival, and by applying the human development index we derived country-specific estimates of the proportion cured and the proportion treated. The fit between the estimates and observed data from the cancer registries was relatively good. The final DALY estimates were similar to those computed using observed values in Norway, and in WHOs earlier global burden of disease study. Marked cross-country differences in the patterns of DALYs by cancer sites were observed. In Norway and Bulgaria, breast, colorectal, prostate and lung cancer were the main contributors to DALYs, representing 54 % and 45 %, respectively, of the totals. These cancers contributed only 27 % and 18 %, respectively, of total DALYs in India and Uganda. CONCLUSIONS: Our approach resulted in a series of variables that can be used to estimate country-specific DALYs, enabling global estimates of DALYs and international comparisons that support priorities in cancer control.     

Osteointegration of titanium implant is sensitive to specific nanostructure morphology

An important aspect of orthopedic implant integration is the enhancement of functional activity of osteoblasts at the tissue-implant interface without any fibrous tissue intervention. Nanostructured implant surfaces are known to enhance osteoblast activity. Previously, we have reported a simple hydrothermal method for the fabrication of non-periodic nanostructures (nanoscaffold, nanoleaves and nanoneedles) on titanium implants showing good biocompatibility and a distinct osteoblast response in vitro in terms of osteoblast adhesion to the surface. In the present work, these nanostructures have been evaluated for their detailed in vitro cellular response as well as in vivo osteointegration. Our studies showed that a specific surface nanomorphology, viz. nanoleaves, which is a network of vertically aligned, non-periodic, leaf-like structures with thickness in the nanoscale, provided a distinct increase in osteoblast cell proliferation, alkaline phosphatase (ALP) activity and collagen synthesis compared to several other types of nanomorphology, such as nanotubes, nanoscaffold and nanoneedles (rods). Gene expression analysis of ALP, osteocalcin, collagen, decorin and Runx2 showed ~20- to 40-fold up-regulation on the leaf-like topography. Cytoskeletal arrangement studies on this substrate again revealed a unique response with favorable intracellular protein expressions of vinculin, FAK and src. In vivo osteointegration study over 12 weeks on rat model (Sprague-Dawley) showed early-stage bone formation (60% bone contact by week 2 and ~85% by week 8, p<0.01) in the leaf-like nanopattern, without any inflammatory cytokine production.     

Evidence to suggest that the human fetal spleen is not a hematopoietic organ

The human fetal spleen commonly is regarded as an organ of hematopoiesis. Because of the authors' interest in myelofibrosis with myeloid metaplasia (MMM) and because the myeloid metaplasia commonly is regarded as a reactivation of embryonic sites of blood formation, spleens from 48 fetuses and stillborn infants were studied, in an attempt to evaluate splenic hematopoiesis (myelopoiesis). The authors employed immunohistologic and cytochemical technics to identify granulocytic, erythroid, and megakaryocytic cells, in contrast to previous studies that have relied solely on conventional morphology. The authors found surprisingly little evidence of hematopoiesis. Virtually no hematopoietic cells of the dividing cell pool were identified, in spite of the fact that the technic used is capable of detecting such immature forms. The results suggests that the spleen is not a significant organ of hematopoiesis in the human fetus but that immature hematopoietic cells found there merely reflect trapping of circulating precursors in the fetal blood. These findings have significant implications for the pathophysiology of MMM.