Imbalanced secondary mucosal antioxidant response in inflammatory bowel disease

Intestinal mucosal damage in the inflammatory bowel diseases (IBD) Crohn's disease (CD) and ulcerative colitis (UC) involves reactive oxygen metabolites (ROMs). ROMs are neutralized by endogenous antioxidant enzymes in a carefully balanced two-step pathway. Superoxide dismutases (SODs) convert superoxide anion to hydrogen peroxide (H(2)O(2)), which is subsequently neutralized to water by catalase (CAT) or glutathione peroxidase (GPO). Remarkably changed expression levels of the three isoforms of SOD in paired non-inflamed and inflamed mucosae from CD and UC patients have been previously reported in comparison to normal control mucosa. Most notable was the strong up-regulation of Mn-SOD in inflamed epithelium. It was hypothesized that in order to provide optimal protection against ROM-mediated damage, these changes should be coordinately counterbalanced by an increased H(2)O(2)-neutralizing capacity. Therefore, the same tissue samples were used to assess the levels, activities, and/or localization of the most prominent mucosal H(2)O(2)-related antioxidants CAT, GPO, glutathione (GSH), myeloperoxidase (MPO), and metallothionein (MT). Quantitative measurements showed that in both CD and UC patients, intestinal inflammation was associated with increased activities of CAT, GPO, and MPO, whereas the mucosal GSH content was unaffected and the concentration of MT was decreased. Despite this overall increase in mucosal H(2)O(2)-metabolizing enzyme capacity, immunohistochemical analysis revealed a differentially disturbed antioxidant balance in IBD epithelium and lamina propria. In the lamina propria, the risk of direct H(2)O(2)-mediated damage seemed to be restrained by the increasing numbers of CAT- and MPO-positive monocytes/macrophages and neutrophils that infiltrated the inflamed areas. On the other hand, MPO overexpression might increase the lamina propria levels of hypochlorous acid, a stable ROM with multiple pro-inflammatory effects. In the epithelium, the number of cells that expressed CAT remained unchanged during inflammation and GPO was found in only a very low and constant number of epithelial cells. In addition, the inflamed epithelium displayed decreased expression of the hydroxyl radical (OH(*)) scavenger MT. In view of the high epithelial SOD levels in inflamed IBD epithelium, it is speculated that the efficient removal of excess H(2)O(2) is hampered in these cells, thereby increasing not only the risk of detrimental effects of H(2)O(2) directly, but also those of its extremely reactive derivatives such as OH(*). Taken together, the results suggest an imbalanced and inefficient endogenous antioxidant response in the intestinal mucosa of IBD patients, which may contribute to both the pathogenesis and the perpetuation of the inflammatory processes.     

Imagery of a moving object: The role of occipital cortex and human MT/V5+

Visual imagery – similar to visual perception – activates feature-specific and category-specific visual areas. This is frequently observed in experiments where the instruction is to imagine stimuli that have been shown immediately before the imagery task. Hence, feature-specific activation could be related to the short-term memory retrieval of previously presented sensory information.Here, we investigated mental imagery of stimuli that subjects had not seen before, eliminating the effects of short-term memory. We recorded brain activation using fMRI while subjects performed a behaviourally controlled guided imagery task in predefined retinotopic coordinates to optimize sensitivity in early visual areas.Whole brain analyses revealed activation in a parieto-frontal network and lateral–occipital cortex. Region of interest (ROI) based analyses showed activation in left hMT/V5+. Granger causality mapping taking left hMT/V5+ as source revealed an imagery-specific directed influence from the left inferior parietal lobule (IPL). Interestingly, we observed a negative BOLD response in V1–3 during imagery, modulated by the retinotopic location of the imagined motion trace.Our results indicate that rule-based motion imagery can activate higher-order visual areas involved in motion perception, with a role for top-down directed influences originating in IPL. Lower-order visual areas (V1, V2 and V3) were down-regulated during this type of imagery, possibly reflecting inhibition to avoid visual input from interfering with the imagery construction. This suggests that the activation in early visual areas observed in previous studies might be related to short- or long-term memory retrieval of specific sensory experiences.     

Phase I immunotherapeutic trial with long peptides spanning the E6 and E7 sequences of high-risk human papillomavirus 16 in end-stage cervical cancer patients shows low toxicity and robust immunogenicity.

PURPOSE: To determine the toxicity, safety, and immunogenicity of a human papillomavirus 16 (HPV16) E6 and E7 long peptide vaccine administered to end-stage cervical cancer patients. EXPERIMENTAL DESIGN: Three groups of end-stage cervical cancer patients (in total n = 35) were s.c. vaccinated with HPV16 E6 combined with or separated from HPV16 E7 overlapping long peptides in Montanide ISA-51 adjuvant, four times at 3-week intervals. Group 1 received 300 microg/peptide at a single site and group 2 received 100 microg/peptide of the E6 peptides in one limb and 300 microg/peptide of the E7 peptides in a second limb. Group 3 received separate injections of E6 and E7 peptides, each at a dose of 50 microg/peptide. The primary end point was to determine safety and toxicity of the HPV16 long peptides vaccine. In addition, the vaccine-induced T-cell response was assessed by IFN gamma enzyme-linked immunospot. RESULTS: No toxicity beyond grade 2 was observed during and after four vaccinations. In a few patients, transient flu-like symptoms were observed. Enzyme-linked immunospot analysis of the vaccine-induced immune response revealed that coinjection of the E6 and E7 peptides resulted in a strong and broad T-cell response dominated by immunity against E6. Injection of the E6 and E7 peptides at two different sites increased the E7 response but did not affect the magnitude of the E6-induced immune response. CONCLUSIONS: The HPV16 E6 and E7 long peptide-based vaccine is well tolerated and capable of inducing a broad IFN gamma-associated T-cell response even in end-stage cervical cancer patients.     

Computer-assisted hand-held dynamometer: low-cost instrument for muscle function assessment in rehabilitation medicine

In rehabilitation medicine, muscle function is assessed during the physical examination of the patient. Although a simple hand-held instrument improves the assessment of static strength, it is rarely used in clinical practice, where dynamic measurements are preferred. A computer-assisted hand-held dynamometer (CAHNDY) has been developed that enables the clinician to measure dynamic muscle function in a standardised manner, using simple (i.e. portable and low-cost) apparatus. The CAHNDY comprises a force transducer and a movement transducer interfaced to a personal computer. In the study dynamic measurement protocols are used, based on a biomechanical analysis of daily activities. In this way, iso-functional profiles can be established, describing the kinematics of muscle function in its functional context. Using the iso-functional profiles as a basis for standardisation, the double feedback algorithm of the CAHNDY assists the tester in meeting this standard, during maximal muscle function testing. In a multi-centre trial, the CAHNDY is evaluated by physical therapists for knee extensor and flexor function. The CAHNDY enables iso-functional dynamic muscle function testing, although application is limited by the maximal strength of the tester. It is concluded that the CAHNDY is suitable for use in rehabilitation medicine.     

Structure-activity relations of water-in-oil vaccine formulations and induced antigen-specific antibody responses

Water-in-oil (W/O) emulsions are known as most effective adjuvants to generate high and durable antibody responses to vaccine antigens following a single immunization. However, their structural requirements remain poorly understood. Here we addressed the significance of certain pharmaceutical characteristics including water/oil ratios--ranging from 60/40 to 30/70 (w/w(%))--droplet size and type of oil, i.e. non-metabolizable (mineral oil) versus metabolizable (Miglyol 840). Stability of emulsions was accomplished by the use of a polymeric emulsifier. Distinct W/O emulsions were formulated with inactivated (i) infectious bronchitis virus (iIBV) and Newcastle disease virus (iNDV), and evaluated in immunized chickens for magnitude and duration of in vivo antiviral antibody formation and local reactions. A high mineral oil content proved most effective for antibody response formation. In general, a larger droplet size evoked higher antibody responses for both oil types. Inoculum residues proved lower using biodegradable Miglyol, when compared to mineral oil, for all emulsion variants. Especially water-to-oil ratio and droplet size may provide useful parameters for improving (antiviral) antibody production by W/O emulsions.