The patterns of cell death and of macrophages in the developing forebrain of the tree shrew Tupaia belangeri

The patterns of cell death and of macrophages were investigated in the forebrain and eyes of the tree shrew Tupaia belangeri during five phases of optic cup formation. Seventeen embryos were studied. Three- dimensional reconstructions were made from one embryo of each phase. In phase 1 (V-shaped optic evagination) a midline band of cell death passes through the closing anterior neuroporus. From phases 2 (optic vesicle) to 5 (far-advanced invagination) the midline band of cell death extends in the dorsal wall of the forebrain to its rostral pole and, further, into its ventral wall. At the approximate future position of the optic chiasm this ventral pycnotic area, predicted but so far unidentified by others, is connected to a previously described second band of cell death passing through the optic anlagen. Recently, evidence has been presented that chicken embryos develop holoprosencephaly and cyclopia when ventral forebrain structures are lost secondary to experimentally induced apoptosis. Our findings in Tupaia suggest that, in cases of spontaneous malformations of this kind, such an atypical pycnotic area in the ventral telencephalon might result from the defective regulation of cell death processes during optic cup formation. In the forebrain and eyes of Tupaia, the occurrence of bands of cell death precedes the appearance of the earliest intraepithelial macrophages. From phase 3 (onset of invagination) onwards almost all of them are concentrated along the band of cell death.     

Berufsbedingte Hauterkrankungen—Paradigma der Sekundärprävention

The dermatologist's procedure was introduced in 1972 by employers' liability insurance funds in the industrial, agricultural and public sectors of Germany's statutory occupational accident insurance as a "procedure for early detection of occupational skin diseases". So far, it is still the most relevant tool for secondary prevention in occupational dermatology in Germany. According to the intention of this procedure, insured persons with a skin disease in which an occupational aetiology is suspected must be offered preventive measures and, if necessary, given appropriate treatment to avoid their losing their jobs. On the initiative of the Central Federation of Industrial Professional Associations (HVBG), a study group was set up in 1999 from among its membership in cooperation with the Working Committee of Occupational and Environmental Dermatology (ABD) and the Professional Organisation of German Dermatologists (BVDD) to improve on the efficiency of the "classic" dermatologist's procedure. The proposed "optimised" dermatologist's procedure is based on the assumption that early detection followed by competent and intensified skin protection and skin care will be successful in retarding or stopping the progression of occupational dermatoses, while later treatment is likely to be less effective. In October 2002, a pilot study started in Northwest Germany to establish by scientific evaluation whether the implementation of secondary protective measures is definitively better when the provisional "optimised" dermatologist's procedure is followed. The study results should allow detailed suggestions for an improved dermatologist's procedure before it is introduced nationwide.     

The orthopan tomoscintigram — a new application of emission computed tomography for facial bone scanning

The exact regional correlation of findings of facial bone scans, planar or SPECT, to dental orthopan X-ray films (OPT) is difficult because of the very different projection techniques. To improve correlative imaging in this regard a projection algorithm was developed that uses SPECT data of the skull for reconstructing an orthopan tomoscintigraphic projection. Fourteen conventional SPECT slices of the upper and lower jaws were obtained during bone scanning. All mandibular slices were superimposed resulting in a horseshoe shaped structure, which was marked by an ROI which was divided into segments. All 14 SPECT slices were then masked by this segmental ROI, thereby marking the teeth-carrying bone in all slices. The information from this horseshoe like ROI is then transformed into lines. Line by line arrangement results in an orthopan projection, the orthopan tomoscintigram. This new display allows 1:1 true scale superimposition with the X-ray OPT and markedly facilitates correlative imaging.     

Pressure/flow relations in the interlamellar space of fish gills: theory and application in the rainbow trout

The nature of the water flow in the interlamellar spaces of fish gills is investigated using the basic fluid mechanical equations. The results show that the gill behaves like a low-pass filter, dampening the amplitude of the velocity oscillation when the frequency of the driving pressure differential exceeds some characteristic value and shifting the phase angle between the pressure and velocity pulses from 0 towards -pi/2. The cut-off frequency is determined by the parameter v/r2, where r is the half-width of the interlamellar space and v the kinematic viscosity. Using known gill dimensions the analysis shows that dampening of the velocity amplitude is not likely to occur at driving pressure frequencies below 100 Hz. Fourier analysis of the pressure differential recorded between buccal and opercular chambers of rainbow trout reveals that there is very little contribution from frequencies above 10 Hz, suggesting that interlamellar water flow is pulsatile and that the possibility for backflow exists.     

Hepatocellular Hyperplasia, Plasmacytoma Formation, and Extramedullary Hematopoiesis in Interleukin (IL)-6/Soluble IL-6 Receptor Double-Transgenic Mice

Cytokines interact not only with membrane anchored receptors, but also with specific soluble receptors which circulate in the bloodstream. In general, soluble cytokine receptors such as soluble tumor necrosis factor receptor, soluble interleukin 1 receptor, and soluble interleukin 4 receptor compete with their membrane-bound counterparts for the ligands and therefore act as antagonists. In contrast, soluble receptors for cytokines of the interleukin-6 (IL-6) family complex with their ligands act agonistically. Interestingly, the complex of IL-6 and the soluble interleukin 6 receptor (sIL-6R) activates target cells that do not express the membrane-bound IL-6R and therefore cannot respond to IL-6. To identify cellular responses that are due to IL-6/sIL-6R but not to IL-6 alone, IL-6/sIL-6R double-transgenic mice were generated and compared with IL-6 single-transgenic mice. IL-6/sIL-6R transgenic mice develop a severe phenotype showing 1) marked hepatocellular hyperplasia frequently surrounded by peliosis and necrosis, 2) significant acceleration and aggravation of plasmacytoma formation, and 3) excessive activation of extramedullary hematopoiesis in spleen and liver followed by a subsequent increase of all cellular components in the peripheral blood. These in vivo data suggest that the sIL-6R recruits primarily unresponsive cell populations such as hematopoietic progenitor cells and hepatocytes to IL-6-induced proliferation, but also enhances the known mitogenic effect of IL-6 on plasma cells and thereby contributes to plasmacytoma formation.     

Combining EL4-B5-based B-cell stimulation and phage display technology for the successful isolation of human anti-Scl-70 autoantibody fragments

Scl-70 is the major antigen recognised by autoantibodies in the sera of patients with systemic sclerosis (SSc). The autoantibodies that specifically react with Scl-70 are highly characteristic of the disease and represent valuable markers for the diagnosis of SSc. We describe a novel strategy for cloning autoantibody fragments starting with a small blood sample from an SSc patient. B cells isolated from the collected peripheral blood mononuclear cells (PBMCs) were cultured in vitro using the EL4-B5 system. Anti-Scl-70 IgG-producing cells were pooled for RNA preparation followed by the generation of phagemid libraries of approximately 10(7) independent single-chain Fvs (scFvs). The screening of these libraries by phage display allowed us to isolate four anti-Scl-70 scFvs following three rounds of biopanning. About 10 times more starting blood material was needed to generate scFv libraries of similar size from PBMCs of an SSc patient and only two anti-Scl-70 scFvs were isolated after three rounds of phage selection. Together, this work shows that functional autoantibody fragments can be advantageously cloned after in vitro expansion of B cells. The isolated anti-Scl-70 autoantibody fragments represent useful tools for calibrating SSc diagnostic assays.     

Deciphering the molecular effects of non-ablative Er:YAG laser treatment in an in vitro model of the non-keratinized mucous membrane

Lasers in Medical Science -     

IL-10 inhibits inducible expression pattern of beta-defensin-2 in human peripheral blood cells]

OBJECTIVE: To investigate the effect of IL-10 on the inducibility of human beta-defensin 2 (hBD-2) in human peripheral blood cells. METHODS: Peripheral blood samples were collected from 22 healthy individuals and co-cultured with 0 ng/ml lipopolysaccharide (LPS), 100 ng/ml LPS, 10 ng/ml IL-10, or 100 ng/ml LPS plus 10 ng/ml IL-10 at 37 degree for 6 h. Total RNA was extracted from peripheral blood cells and the mRNA level of hBD-2 was detected by relative quantitative real-time PCR.. RESULT: No detectable level of hBD-2 mRNA was found in normal peripheral blood cells with stimulation of 0 ng/ml LPS or 10 ng/ml IL-10. The mRNA level of hBD-2 was increased to 166.9 +/- 35.14 after 100 ng/ml LPS challenge, while the mRNA level of hBD-2 was decreased to 30.40 +/- 9.18 after the co-stimulation of 100 ng/ml LPS plus 10 ng/ml IL-10; which was significantly lower than that with LPS alone (P<0.05). CONCLUSION: The expression of hBD-2 gene can be induced by LPS.IL-10 inhibits the inducible expression of hBD-2.