Mitigation of delayed-type hypersensitivity reactions by a CD44 variant isoform v3-specific antibody: blockade of leukocyte egress.

In allergic alterations of human skin the majority of infiltrated leukocytes express CD44v3, but no other CD44 variant isoform. Vessel endothelium, too, is brightly stained with a CD44v3-specific antibody. Being concerned about therapeutic intervention, it became of importance to define whether expression of CD44v3 on the endothelial cells or on the leukocytes or on both is of functional importance. As expression of CD44v3 in the mouse on activated endothelium and on subpopulations of activated CD4+ cells, B cells and monocytes was similar to the expression in the human, we answered the question in a mouse delayed-type hypersensitivity model. The effect of anti-CD44v3 was compared with the effect of anti-CD44s and anti-CD44v10, both known to suppress delayed-type hypersensitivity reactions. Anti-CD44v3 mitigated the delayed-type hypersensitivity reaction in dinitrofluorobenzene sensitized and challenged mice comparable with anti-CD44s and anti-CD44v10. The seemingly similar effects of CD44 isoform-specific antibodies, however, resulted from a distinct modulation of response. Anti-CD44s mainly suppressed T cell activation and interleukin-2 as well as interferon-gamma expression. Anti-CD44v10 inhibited the activation of monocytes in the draining lymph nodes and in the infiltrate, which led to a strong reduction in the proinflammatory cytokines tumor necrosis factor-alpha and interleukin-12 and in edema formation. Anti-CD44v3 had only a weak effect on cytokine expression by isolated subpopulations of leukocytes, but suppressed cytokine production by helper T cells when cocultured with antigen-presenting cells, i.e., blocked an interaction between antigen-presenting cells and helper T cells. The dominating effect of anti-CD44v3, however, relied on a blockade of leukocyte extravasation. As leukocytes transferred into dinitrofluorobenzene sensitized, anti-CD44v3-treated and lethally irradiated mice did not infiltrate the sensitized skin, anti-CD44v3 most likely prevented leukocyte extravasation by blocking CD44v3 on endothelial cells.     

Transient CD44 variant isoform expression and reduction in CD4(+)/CD25(+) regulatory T cells in C3H/HeJ mice with alopecia areata

Alopecia areata, an autoimmune disease affecting anagen stage hair follicles, can be induced by grafting spontaneous alopecia areata affected skin to normal-haired C3H/HeJ mice. As the onset of alopecia areata can be significantly retarded by anti-CD44 variant isoform 10 treatment, it was interesting to explore the underlying disease mechanism. Two weeks after transplanting alopecia areata affected skin, expression of CD44 variant isoforms 3, 6, 7, and 10 was strikingly upregulated as compared with sham-grafted mice. By 6 wk after grafting, CD44 variant isoform levels had returned to normal, whereas in draining lymph nodes, CD44 variant isoform expression was slightly decreased. Leukocytes in the skin of mice with chronic alopecia areata expressed a hematopoietic isoform of CD44 and CD44 variant isoform 6 at an elevated level, but CD44 variant isoform 3 expression was reduced. Cytokine expression in leukocytes of chronic alopecia areata affected skin was higher than in normal-haired controls. Cytokine expression also increased postsurgery in sham and alopecia areata grafted mice, but remained elevated only in mice receiving alopecia areata affected skin. Finally, from the skin of mice with chronic alopecia areata and of mice transplanted with alopecia areata affected skin, an increased number of CD4(+) and CD8(+) cells, but a strongly decreased number of CD4(+)/CD25(+) regulatory T cells was recovered. Thus, expression of CD44 variant isoforms is important for the migration of leukocytes during the initial period of alopecia areata. CD44, however, is apparently not involved in the maintenance of the disease state, which is characterized by high cytokine expression levels, an increased number of CD4(+) and CD8+ cells, but a low level of CD4(+)/CD25(+) suppressor cells.     

Electromagnetic navigation during flexible bronchoscopy

BACKGROUND: Flexible bronchoscopy is routinely utilized in the diagnosis and treatment of various lung diseases. Nondiagnostic bronchoscopy leads to more invasive interventions, such as transthoracic needle aspiration, mediastinoscopy or even thoracotomy. Electromagnetic navigation is a novel technology that facilitates approaching peripheral lung lesions, which are difficult to sample by conventional means. The navigation system involves creating an electromagnetic field around the chest and localizing an endoscopic tool using a microsensor overlaid upon previously acquired CT images. OBJECTIVES: To determine the practicality, accuracy and safety of real-time electromagnetic navigation, coupled with previously acquired 3D CT images, in locating artificially created peripheral lung lesions in a swine model. METHODS: Peripheral lung lesions were created in four swine models by insertion of a metal tube (1 x 10 mm) via a transthoracic approach. An electromagnetic field was created by placing the animal on an electromagnetic location board. A position sensor incorporated into the distal tip of a dedicated tool was used to navigate to the various target lesions. Information gathered in real time during bronchoscopy was presented on a monitor simultaneously by displaying previously acquired CT images. Upon reaching the target lesion, biopsies were performed and the functionality and safety of the superDimension/Bronchus System was observed and documented. RESULTS: The registration accuracy expressed by the fiducial target registration error, expressing both the registration quality and the stability of fiducial (registration) points, was 4.5 mm on average. No adverse effects, such as pneumothorax or internal bleeding, were encountered in any of the animals in this study. CONCLUSIONS: Real-time electromagnetic positioning technology coupled with previously acquired CT images is an accurate technology added to standard bronchoscopy to assist in reaching peripheral lung lesions and performing biopsies.     

The diagnostic value of the fibrinogen/fibrin fragment E antigen assay in clinically suspected deep vein thrombosis

We have evaluated the fibrinogen/fibrin fragment E antigen assay as a diagnostic test in patients with clinically suspected venous thrombosis by comparing the results of this assay with venography in 272 patients. The result of the fragment E antigen assay was elevated in 79 of 80 patients with positive venograms for recent venous thrombosis (sensitivity 99%) and within the normal range in 161 of 192 patients with normal venograms (specificity 84%). The fragment E assay was also evaluated in 130 medical and surgical controls without evidence of venous thrombosis by leg scanning and the test was found to be relatively nonspecific. However, in the patient group under study, a correct clinical diagnosis of no thrombosis, based on a normal fragment E result, was made in 161 of 162 cases (negative predictive value of 99%). Therefore, a normal test result effectively excludes a diagnosis of venous thrombosis in clinically symptomatic patients. The assay, as currently performed, is technically demanding and takes 24 hr to complete. Therefore, it will have to be simplified before it can be applied to clinical practice.     

Comparative toxicity of physiological and biochemical parameters in Euglena gracilis to short-term exposure to potassium sorbate

Ecotoxicology - Potassium sorbate is the potassium salt of sorbic acid, is a widespread and efficient antioxidant that has multiple functions in plants, traditionally associated with the reactions...     

The stress protein BiP is overexpressed and is a major B and T cell target in rheumatoid arthritis

OBJECTIVE: The ubiquitously expressed intracellular protein formerly designated p68 has been identified as autoantigen at both the antibody and the T cell level in rheumatoid arthritis (RA). METHODS: We used 2 independent approaches, Edman degradation and matrix-assisted laser desorption ionization-time-of-flight mass spectrometry, to characterize p68, and we compared its features with those of the endoplasmic reticulum stress protein BiP. RESULTS: In synovial sections from RA patients, BiP was highly overexpressed as compared with control sections. Under in vitro stress conditions, BiP was found to translocate to the nucleus and the cell surface. BiP-specific autoantibodies were present in 63% of 400 RA patients, in 7% of 200 patients with other rheumatic diseases, and in none of the healthy subjects. Thus, BiP-specific autoantibodies represent a new diagnostic marker in RA. Furthermore, we found that BiP-specific T cell reactivity was altered in RA. In healthy individuals and patients with other rheumatic diseases, BiP-reactive T cells were undetectable. In RA, overt T cell reactivity to BiP was observed or could be induced by specifically blocking antigen presentation to potentially regulatory T cells. CONCLUSION: Since overexpression of BiP has been shown to decrease the sensitivity of cells to killing by cytotoxic T cells, BiP overexpression and BiP-specific autoimmunity may be involved in the pathogenesis of RA.     

Galactorrhea during antipsychotic treatment: results from AMSP,a drug surveillance program,between 1993 and 2015

European Archives of Psychiatry and Clinical Neuroscience - Galactorrhea is a well-known adverse drug reaction (ADR) of numerous antipsychotic drugs (APD) and is often distressing for those...