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Role of cholesterol in human immunodeficiency virus type 1 envelope protein-mediated fusion with host cells.

In this study we examined the effects of target membrane cholesterol depletion and cytoskeletal changes on human immunodeficiency virus type 1 (HIV-1) Env-mediated membrane fusion by dye redistribution assays. We found that treatment of peripheral blood lymphocytes (PBL) with methyl-beta-cyclodextrin (MbetaCD) or cytochalasin reduced their susceptibility to membrane fusion with cells expressing HIV-1 Env that utilize CXCR4 or CCR5. However, treatment of human osteosarcoma (HOS) cells expressing high levels of CD4 and coreceptors with these agents did not affect their susceptibility to HIV-1 Env-mediated membrane fusion. Removal of cholesterol inhibited stromal cell-derived factor-1alpha- and macrophage inflammatory protein 1beta-induced chemotaxis of both PBL and HOS cells expressing CD4 and coreceptors. The fusion activity as well as the chemotactic activity of PBL was recovered by adding back cholesterol to these cells. Confocal laser scanning microscopy analysis indicated that treatment of lymphocytes with MbetaCD reduced the colocalization of CD4 or of CXCR4 with actin presumably in microvilli. These findings indicate that, although cholesterol is not required for HIV-1 Env-mediated membrane fusion per se, its depletion from cells with relatively low coreceptor densities reduces the capacity of HIV-1 Env to engage coreceptor clusters required to trigger fusion. Furthermore, our results suggest that coreceptor clustering may occur in microvilli that are supported by actin polymerization.

CD4-Positive T-Lymphocytes↗

Reduced infarct volume and differential effects on glial cell activation after hyperbaric oxygen treatment in rat permanent focal cerebral ischaemia.

Permanent middle cerebral artery occlusion (MCAO) causes neurodegeneration and a robust activation of glial cells primarily in sensorimotor brain regions of rats. It has been shown that hyperbaric oxygen (HBO) increases oxygen supply to ischaemic areas and reduces neuronal cell loss. The effects of HBO treatment on microgliosis and astrogliosis in permanent cerebral ischaemia have not been addressed so far, but might be critical for neurodegeneration and neuroprotection, respectively. Therefore, we used spontaneously hypertensive rats with permanent MCAO to investigate the time window to start HBO and to compare the effects of different HBO treatment frequencies on infarct volume and on differences with regard to microgliosis and astrogliosis. Seven days after MCAO the infarct volume was calculated from Nissl-stained brain sections by image analysis. HBO significantly decreased the infarct volume when used as early as 15, 90 or 180 min post-MCAO by 24%, 16% and 13%, respectively, in the single-treatment group. Repetitive HBO treatment (first HBO session 90 min after MCAO) was not effective. Microglial cells and astrocytes were detected by cytochemical fluorescent labelling and confocal laser scanning microscopy. In the single-treatment group we observed significantly higher astrocyte immunoreactivity but decreased microglial density in the peri-infarct region. These effects of HBO treatment on glial cells were not present in rats where HBO did not reduce the infarct volume (360 min after MCAO). Our data indicate that HBO-induced suppression of microgliosis and aggravated response of astrocytes might contribute to the reported beneficial effects of early HBO treatment in cerebral ischaemia.

Animals↗

P-glycoprotein expression in the Golgi apparatus of multidrug-resistant cells.

The surface and intracellular expression of mdrI-P-glycoprotein in parental drug-sensitive human breast cancer cells (MCF-7) and their multidrug-resistant (MDR) variants has been studied by using the monoclonal antibodies (MAbs) MM4.17 and MRK-16, which recognize 2 different epitopes of the drug efflux pump molecule. Fluorescence microscopic observations showed that P-glycoprotein, in addition to being located at the cell surface, can also be found in the Golgi apparatus of resistant cells. To confirm this finding, Golgi apparatus and P-glycoprotein were double-labelled with wheat-germ agglutinin (WGA) and MAb MM4.17. Laser scanning confocal microscopy indicated that, in MDR cells, Adriamycin mainly accumulated cytoplasmically in a perinuclear region. This accumulation proved to be modulated by pre-treatment with verapamil or ATP depletion. Moreover, the vital staining of Adriamycin-treated MDR cells, performed with the fluorescent lipid N-[7-(4-nitrobenzo-2-oxa-1,3-diazole)]- 6-aminocaproyl sphingosine (C6-NBD-ceramide), revealed that the anthracyclinic antibiotic was located in the Golgi apparatus. All these results indicate that the drug transporter is located in the Golgi apparatus, in which Adriamycin molecules also accumulate.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

Contraction of collagen lattices by cells from Dupuytren's nodules.

The aim of this study was to see if nodular cells in Dupuytren's disease differed from dermal cells in their contractile capacity and motility. Ten surgical specimens from patients with Dupuytren's disease and contracture of the finger of more than 45 degrees were harvested and the nodular cells were explanted and cultured. Dermal fibroblasts from the forearm were used as control cells. Both types of cell had the same growth pattern. The morphology on confocal laser scanning microscopy was also similar in both types of cell. Dermal control cells caused significantly more contraction of collagen lattices compared with fibroblasts from nodules of Dupuytren's contracture. The F-actin content was equal in both groups. Platelet derived growth factor, PDGF-BB (but not PDGF-AA), increased the chemotactic activity of both cell types, but there were no differences between them. The results indicate that at a late state of the disease cells from Dupuytren's nodules lose their contractile capacity and regain a phenotype resembling that of dermal fibroblasts.

Animals↗

Subcellular distribution of cytokeratin and vimentin in malignant rhabdoid tumor: three-dimensional imaging with confocal laser scanning microscopy and double immunofluorescence.

Malignant rhabdoid tumor (MRT) is a highly aggressive neoplasm that mostly occurs in childhood, characterized histologically by rhabdoid cells as shown by eosinophilic intracytoplasmic inclusions. Although it is known that rhabdoid cells co-express cytokeratin (CK) and vimentin, the distribution patterns of these two kinds of intermediate filaments and structural relationship between them are still not known. We investigated the subcellular distribution of CKs 8 and 18 and vimentin in MRT cell lines (Tm87-16, STM91-01, TTC549, and TC289) using confocal laser scanning microscopy and double immunofluorescence, in addition to ultrastructural examination. Vimentin was diffusely expressed in the cytoplasm of MRT cells, focally forming a filamentous network. In contrast, CKs 8 and 18 were partially expressed in the cytoplasm of MRT cells, forming globules or a few vague agglomerates. Three-dimensional images in TC289 cells revealed distinct distribution patterns of cytokeratin and vimentin, showing agglomerates of cytokeratins within the vimentin filament network. We conclude that these globules and agglomerates of CKs 8 and 18 correspond with the characteristic ultrastructural finding, showing cytoplasmic bundles of intermediate filaments concentrated in whorled arrays.

Female↗

Complexation of ytterbium to human transferrin and its uptake by K562 cells.

There is an increasing interest in the use of lanthanides in medicine. However, the mechanism of their accumulation in cells is not well understood. Lanthanide cations are similar to ferric ions with regard to transferrin binding, suggesting transferrin-receptor mediated transport is possible; however, this has not yet been confirmed. In order to clarify this mechanism, we investigated the binding of Yb3+ to apotransferrin by UV-Vis spectroscopy and stopped-flow spectrophotometry, and found that Yb3+ binds to apotransferrin at the specific iron sites in the presence of bicarbonate. The apparent binding constants of these sites showed that the affinity of Yb3+ is lower than that of Fe3+and binding of Yb3+ in the N-lobe is kinetically favored while the C-lobe is thermodynamically favored. The first Yb3+ bound to the C-lobe quantitatively with a Yb/apotransferrin molar ratio of < 1, whereas the binding to the other site is weaker and approaches completeness by a higher molar ratio only. As demonstrated by 1H NMR spectra, Yb3+ binding disturbed the conformation of apotransferrin in a manner similar to Fe3+. Flow cytometric studies on the uptake of fluorescein isothiocyanate labeled Yb3+-bound transferrin species by K562 cells showed that they bind to the cell receptors. Laser scanning confocal microscopic studies with fluorescein isothiocyanate labeled Yb3+-bound transferrin and propidium iodide labeled DNA and RNA in cells indicated that the Yb3+ entered the cells. The Yb3+-transferrin complex inhibited the uptake of the fluorescein labeled ferric-saturated transferrin (Fe2-transferrin) complex into K562 cells. The results demonstrate that the complex of Yb3+-transferrin complex was recognized by the transferrin receptor and that the transferrin-receptor-mediated mechanism is a possible pathway for Yb3+ accumulation in cells.

Binding, Competitive↗

Membrane topography of HLA I, HLA II, and ICAM-1 is affected by IFN-gamma in lipid rafts of uveal melanomas.

The lateral distribution and colocalization of HLA I, HLA-DR, and ICAM-1 proteins was studied for the first time in the plasma membrane of two human uveal melanoma cell lines, OCM-1 and OCM-3. Our fluorescence resonance energy transfer and confocal laser scanning microscopic experiments revealed that these molecules are mostly confined to the same membrane regions, where they form similar protein patterns (homo- and hetero-associates) to those found previously on other cell types of lymphoid as well as colorectal carcinoma origin. Confocal microscopic colocalization experiments with GM(1) gangliosides and the GPI-anchored CD59 molecules showed enrichment of HLA I, HLA-DR, and ICAM-1 molecules in specific membrane domains (lipid rafts) excluding the transferrin receptor. IFN-gamma remarkably increased the expression levels of these molecules and rearranged their association patterns, which can affect the adoptive immune response of effector cells.

Flow Cytometry↗

In vitro and in vivo targeting properties of iodine-123- or iodine-131-labeled monoclonal antibody 14C5 in a non-small cell lung cancer and colon carcinoma model.

PURPOSE: The monoclonal antibody (mAb) 14C5 is a murine IgG1 directed against a yet undefined molecule involved in cell substrate adhesion found on the surface of malignant breast cancer tissue. mAb 14C5 is able to inhibit cell substrate adhesion and invasion of breast cancer cells in vitro. In normal tissues as well as in the stroma surrounding in situ carcinomas of the breast, no expression of the antigen 14C5 occurs. The aim of this study was to investigate the in vitro and in vivo targeting properties of 123I- and 131I-labeled mAb 14C5 as a novel agent for radioimmunodetection and radioimmunotherapy. EXPERIMENTAL DESIGN: Internalization of mAb 14C5 was investigated with 125I-labeled mAb 14C5 and by confocal laser scanning microscopy. Biodistribution studies of 131I-labeled mAb 14C5 and planar gamma imaging were done in nude mice bearing an A549 (non-small cell lung carcinoma) or a LoVo (colon carcinoma) tumor. RESULTS: Internalization studies with both A549 and LoVo cells showed that 125I-labeled mAb 14C5 is slowly internalized with approximately 30% of the initially bound mAb 14C5 internalized after 2 hours at 37 degrees C. Internalization of mAb 14C5 could be visualized with confocal laser scanning microscopy. In vivo, radioisotope uptake peaked at 24 hours for both tumor models (n = 5) with no significant difference in percentage of injected dose/g tissue (A549 10.4 +/- 0.8 and LoVo 9.3 +/- 0.8). Via planar gamma camera imaging, A549 lung tumors as well as LoVo colon tumors could be clearly visualized. CONCLUSIONS: The in vitro and in vivo targeting properties of 123I- and 131I-labeled mAb 14C5 are promising and could provide a new antibody-based agent for radioimmunodetection and radioimmunotherapy of patients bearing antigen 14C5-expressing tumors.

Animals↗

Fluorescent in-situ hybridization to detect cellular RNA by flow cytometry and confocal microscopy.

A fluorescent in-situ hybridization procedure was developed which is suitable for detection of specific cellular RNA in cells fixed in suspension. The procedure was originally developed for analysis of single-cell suspensions by flow cytometry. The resulting fluorescent cells proved to have their 3-D morphology perfectly preserved. The spatial distribution of specific ribosomal RNA and messenger RNA could then be analysed by confocal microscopy of individual cells. In the hybridization procedure, biotinylated single-stranded RNA probes were used that were produced by transcription from cloned DNA fragments. Detection of poly-(A)+ RNA was performed with a poly-biotin-d(U)-tailed oligo-d(T) probe. Bound probe was detected using streptavidin-fluorescein isothiocyanate. For flow cytometry, nuclear DNA was counterstained with di-amidine-2-phenyl indol. Multi-parameter flow cytometry was used to quantify the fluorescence intensity, i.e. the hybridization signal, of thousands of cells. Confocal scanning microscopy on individual cells revealed the intracellular distribution of the target RNA. The distribution of ribosomal RNA and poly-(A)+ RNA mRNA in mouse bone marrow and the human leukaemia cell line HL60 cells was investigated. Ribosomal RNA was confined to the cytoplasm of the cells, although in many cells the nucleoli could also be distinguished. Poly-(A)+ RNA in HL60 cells was found both in the cytoplasm and nucleus. A granular cytoplasmic distribution was seen in part of these cells.

Animals↗

Imaging of L-type Ca2+ channels in olfactory bulb neurones using fluorescent dihydropyridine and a styryl dye.

We have imaged the fluorescence of dihydropyridine-Bodipy (fDHP) in cultured olfactory bulb neurones in order to investigate the subcellular distribution of L-type calcium channels in these neurones. The neurones were stained with both fDHP and the voltage-sensitive styryl dye RH414. The fluorescence emission maxima of these dyes were in the green and red ranges of the spectrum, respectively, and were recorded by the 2 photomultiplier channels of a laser scanning microscope. The fDHP images were ratioed with the RH414 images taken simultaneously. The resulting ratio images revealed the spatial distribution of the surface density of L-type calcium channels. This density was highest on somata, in particular at the base of dendrites, and decreased with the distance from this maximum. Two classes of dendritic L-type channel distributions were observed: one with a homogeneously low density and another one with a characteristic gradient of the L-type channel density along proximal dendrites. This subcellular localization of L-type calcium channels is discussed in the light of specific functional roles.

Animals↗

Fas ligand-independent, FADD-mediated activation of the Fas death pathway by anticancer drugs.

Trimerization of the Fas receptor (CD95, APO-1), a membrane bound protein, triggers cell death by apoptosis. The main death pathway activated by Fas receptor involves the adaptor protein FADD (for Fas-associated death domain) that connects Fas receptor to the caspase cascade. Anticancer drugs have been shown to enhance both Fas receptor and Fas ligand expression on tumor cells. The contribution of Fas ligand-Fas receptor interactions to the cytotoxic activity of these drugs remains controversial. Here, we show that neither the antagonistic anti-Fas antibody ZB4 nor the Fas-IgG molecule inhibit drug-induced apoptosis in three different cell lines. The expression of Fas ligand on the plasma membrane, which is identified in untreated U937 human leukemic cells but remains undetectable in untreated HT29 and HCT116 human colon cancer cell lines, is not modified by exposure to various cytotoxic agents. These drugs induce the clustering of Fas receptor, as observed by confocal laser scanning microscopy, and its interaction with FADD, as demonstrated by co-immunoprecipitation. Overexpression of FADD by stable transfection sensitizes tumor cells to drug-induced cell death and cytotoxicity, whereas down-regulation of FADD by transient transfection of an antisense construct decreases tumor cell sensitivity to drug-induced apoptosis. These results were confirmed by transient transfection of constructs encoding either a FADD dominant negative mutant or MC159 or E8 viral proteins that inhibit the FADD/caspase-8 pathway. These results suggest that drug-induced cell death involves the Fas/FADD pathway in a Fas ligand-independent fashion.

Antigens, Surface↗

X chromosome territories in human female lymphocytes.

We developed an improved bromodeoxyuridine (BrdU)-DNA assay procedure for flow cytometric analysis. Which makes possible cytochemical investigation against cells after BrdU-DNA assay, such as immunochemical staining or in situ hybridization. Using this method, we performed fluorescence in situ hybridization (FISH) technique using DNA probes that recognize whole X chromosome of human lymphocytes in peripheral blood (resting cells) and cultured cells stimulated by phytohemagglutinin (PHA) (proliferative cells). Cultured cells were fractionated precisely into each stage of cell cycle by cell sorter after flow cytometric analysis. Following FISH procedure, the cells were examined for the volumes of two X chromosome territories in the nuclei using the optical section images on a confocal laser scanning microscope (CLSM). And we analyzed the variation in the volume ratio (R) of two X chromosome territories at different stages in cell cycle. Our data indicated that there were no significant difference between the volume of two X chromosome territories in female human lymphocytes at resting (G0) stage. Furthermore, they also showed no significant alternation throughout the cell cycle. These results may challenge the traditional concepts for inactivated chromosome in two points. First, the inactivated X chromosome is more decondensed throughout the cell cycle than previously thought. Second, although the inactivated X chromosome appears more decondensed during its self replication it dose not bring a great change in the volume of its territory.

Cells, Cultured↗

Differential mechanisms targeting type 1 plasminogen activator inhibitor and vitronectin into the storage granules of a human megakaryocytic cell line.

Type 1 plasminogen activator inhibitor (PAI-1) and its cofactor vitronectin (Vn) are stored within the alpha-granules of platelets. The two possible sources for their biosynthetic origin are endogenous synthesis in megakaryocytes or endocytosis from plasma. Using ultrastructural and confocal laser scanning microscopic (CLSM) image analysis, we observed that treatment of Dami cells, a human megakaryocytic cell line, with phorbol myristate acetate (PMA) induces the accumulation of PAI-1 and Vn in intracellular storage vacuoles that contain other alpha-granule proteins such as von Willebrand factor. To examine evidence for biosynthesis of PAI-1 and Vn by Dami cells, we immunoprecipitated PAI-1 and Vn from the conditioned media of cells biosynthetically radiolabeled with 35S-methionine in the presence or absence of PMA. In contrast to Hep G2 cells, which synthesize both PAI-1 and Vn, only 35S-PAI-1 was recovered from PMA-treated Dami cells. Reverse transcription-PCR analysis of RNA extracted from resting and PMA-treated Dami cells confirmed that PAI-1 mRNA expression was detectable at low levels in resting cells and induced by PMA treatment. In contrast, Vn mRNA was not detected. We examined binding and internalization (endocytosis) of PAI-1 and Vn by Dami cells using biotinylated analogs (b-PAI-1 and b-Vn). Flow cytometry analysis indicated that the binding of b-Vn to Dami cells was dose-dependent, saturable, and specific for multimeric forms of Vn. Cells were incubated at 4 degrees C or 37 degrees C and endocytosis of b-Vn was shown by probing electrophoretically fractionated cell lysates with 125I-labeled streptavidin. Only cells incubated at 37 degrees C internalized b-Vn. CLSM image analysis confirmed that the b-Vn was internalized and that it colocalized with PAI-1 in storage granules. The binding of b-Vn to cells was inhibited by the presence of PAI-1, and there was no evidence of specific b-PAI-1 binding or uptake to resting or PMA-treated cells. These data suggest that accumulation of PAI-1 in Dami cell storage granules is due to endogenous synthesis and that the accumulation of Vn is due to endocytosis of serum-derived Vn.

Base Sequence↗

Beta protein precursor expression in human platelets and a megakaryocyte cell line. Possible implications for the origin of cerebral amyloidosis in Alzheimer's disease.

BACKGROUND: The origin of the amyloid beta protein (A beta) that is the main constituent of amyloid fibrils occurring in the senile plaques and cerebrovasculature of individuals afflicted with Alzheimer's Disease, Down's Syndrome, Hereditary Cerebral Hemorrhage with Amyloidosis--Dutch Type, and Sporadic Cerebral Amyloid Angiopathy, is central to the pathogenesis of these disorders. Evidence exists to support a neuronal and/or a vascular origin. We have reported that platelets may serve as one possible source of the A beta sequence via an intact, membrane-associated Beta Protein Precursor (beta PP) which is encoded by a platelet transcript (BBRC 173:1292-1298, 1990). EXPERIMENTAL DESIGN: Immunoaffinity chromatography and western blotting of extracted cellular proteins, polymerase chain reaction amplification of beta PP mRNA, fluorescence activated flow cytometric analysis, and confocal scanning laser microscopy have been employed to characterize the presence and distribution of thrombocytic beta PP. RESULTS: Immunoblot analysis with antibodies specific for the carboxyl-terminal end of beta PP indicates that platelets and the Dami megakaryocyte cell line express membrane-associated species of intact beta PP ranging in molecular weight from 110 to 140 kilodaltons (kd), as well as carboxyl-terminal reactive forms ranging from 16 to 22 kd. Thrombin stimulation of platelets induces the release of five soluble beta PP species, which possess apparent isofocusing points in the range of 4.1-5.5. By contrast, extracts of peripheral blood mononuclear cells enriched by ficoll centrifugation, endothelial cells and a B cell line were not immunoreactive by western blot, even though beta PP transcripts could be amplified by polymerase chain reaction. The distribution of platelet beta PP was localized by flow cytometric analysis and scanning laser microscopy, using fluorescein-labeled antibodies. Study of the subcellular distribution of platelet beta PP indicates that these translation products are accumulated in discrete foci throughout the thrombocyte, possibly corresponding to secretory granules. CONCLUSIONS: The size of the carboxyl-terminal forms of beta PP indicate that the A beta sequence is present as a membrane associated constituent in unstimulated platelets, and may represent alternative pathways of beta PP processing. Cleavage or other abnormal processing of platelet-associated beta PP in Alzheimer's disease provides one mechanism whereby cerebral amyloid might derive from the circulation.

Alzheimer Disease↗

Neospora caninum NcSRS2 is a transmembrane protein that contains a glycosylphosphatidylinositol anchor in insect cells.

We investigated the terminal location of NcSRS2, a surface antigen of Neospora caninum that has potential use for diagnosis, and demonstrated its importance as a vaccine component against neosporosis, in an insect-baculovirus expression system. To examine the role of the hydrophobic C-terminal tail in NcSRS2, four types of recombinant baculoviruses were constructed. Immunoblotting and N-terminal amino acid analysis revealed cleavage of a 6 kDa of the N-terminal signal peptide in the mature NcSRS2 protein. The recombinant NcSRS2 (rNcSRS2) lacking 25, and 62 amino acids from the termination codon were detected in supernatants from recombinant virus-infected cells, but not in recombinants with truncated 147 amino acids from the termination codon, and intact NcSRS2 gene (401 amino acids). By flow cytometric and confocal laser scanning microscopic analyses, the truncation of the hydrophobic C-terminal tail in NcSRS2 was shown to result in the reduction of protein expression on the cell surface relative to intact rNcSRS2. Except for the recombinant lacking the 147 C-terminal residues, three other rNcSRS2 were detected in the supernatants after treatment with phosphatidylinositol-specific phospholipase C. Our results demonstrate that the N. caninum NcSRS2 is a transmembrane protein that contains a glycosylphosphatidylinositol-anchor molecule in insect cells, and that the hydrophobic C-terminal domain is an essential component for GPI-membrane attachment. We have likewise shown the usefulness of the insect-recombinant baculovirus system in the expression of rNcSRS2.

Animals↗

[Diagnostic and biostimulating lasers].

In this brief report authors present data regarding the application of diagnostic and biostimulating laser instruments in medicine. For diagnostic purposes there are several types of laser instruments and procedures available: Laser Microscopic Masonic Analyzer (LAMMA), Flow cytometry. Doppler effects of laser rays (Laser Doppler velocytometry, Laser Doppler spermokhinezymetry, Laser Doppler spectrometry), Laser fluorescent microscopy, Laser nephelometry, Transilumination by lasers (diaphanography), Laser spectroscopy, Laser holography, Laser rethinoscopy, Microirradiation by lasers. Literary data concerning favorable effects of low power laser radiation on series of diseases covering different medical specialties are cited, pointing to possibility of significant enrichment of already available arsenal of physical methods, thera-pies and rehabilitation procedures. Mechanisms of biostimulation of human tissues and organs under low power laser radiation are also presented. All these stimulatory and regulatory mechanisms of the cell metabolism are involved in the wound epitelization, reduction of edema and inflammation and reestablishement of arterial, venous and lymph microcirculation and consequently inducing better tissue nutrition. The use of laser spectroscopy for quantitative analysis of cations from a single drop of dried blood on a piece of filter paper was not realized, although individual analyses of frozen skin biopsies for calcium, arsenic and gold were accomplished. In Europe, this technique has also found its application in forensic medicine. Furthermore, laser-based methods have been used to study air pollution with carcinogens in occupational exposures and also for the detection of narcotic drugs. Laser cytofluorometry utilizes the argon laser for scanning of single stained cells and has achieved utilization in mass examination programs for Pap-smear determinations. The same technique is used in cell sorting system that is now important in monoclonal antibody determination in hybridoma technology. Other possible diagnostic applications include laser particle size measurement techniques, and laser nephelometry for determination of immunoglobulins classes and autoantibodies such as rheumatoid factors. Laser Doppler velocimetry is used to measure blood flow by means of a simple probe that rests on the lip. Biostumulating laser instruments The world famous Hungarian scientist Mester Endre, from Budapest, is one of the pioneers with the greatest experimental and clinical experience in the use of biostimulating effects of lasers. His former student, O. Ribari first used biostimulating effects of He-Na laser (390 mJ power) for the epitelization of perforated tympanic membrane and treatment of postoperative fistulas of the neck and of the mastoid. Generally speaking, biostimulating effect of low level laser treatment (LLLT) is in its anti-inflammatory, analgesic and anti-edematous effect on tissues. There is absolute increase in microcirculation, higher rates of ATP, RNA and DNA synthesis, and thus better tissue oxygenation and nutrition. There is also increase in the absorption of interstitial fluid, better tissue regeneration and stimulation of the analgesic effect. The past three decades of laser medicine and surgery have shown great progress and promise for the future.

Humans↗

Increased expression of DC-SIGN+IL-12+IL-18+ and CD83+IL-12-IL-18- dendritic cell populations in the colonic mucosa of patients with Crohn's disease.

Dentritic cells (DC) as antigen-presenting cells are most likely responsible for regulation of abnormal T cell activation in Crohn's disease (CD), a chronic inflammatory bowel disease. We have analyzed the expression of activation and maturation markers on DC in the colon mucosa from patients with CD compared with normal colon, using immunohistochemical techniques. We found two distinct populations of DC present in CD patients: a DC-specific ICAM-3 grabbing non-integrin (DC-SIGN)(+) population that was present scattered throughout the mucosa, and a CD83(+) population that was present in aggregated lymphoid nodules and as single cells in the lamina propria. In normal colon the number of DC-SIGN(+) DC was lower and CD83(+) DC were detected only in very few solitary lymphoid nodules. Co-expression of activation markers and cytokine synthesis was analyzed with three-color confocal laser scanning microscopy analysis. CD80 expression was enhanced on the majority of DC-SIGN(+) DC in CD patients, whereas only a proportion of the CD83(+) DC co-expressed CD80 in CD as well as in normal tissue. Surprisingly, IL-12 and IL-18 were only detected in DC-SIGN(+) DC and not in CD83(+) DC. A similar pattern of cytokine production was observed in normal colon albeit to a much lesser extent. The characteristics of these in-situ-differentiated DC markedly differ from the in-vitro-generated DC that simultaneously express DC-SIGN, CD83 and cytokines.

Adult↗

The characteristics of tolerogenic plasmacytoid dendritic cells stimulated with interleukin-3.

This study focused on whether bone marrow would differentiate tolerogenic dendritic cells (DCs) by comparing interleukin-3 (IL-3) DCs (induced by IL-3+IL-4) with GM-CSF DCs (induced by GM-CSF+IL-4, generating myeloid DCs). Mouse bone marrow progenitors were induced in vitro to differentiate into DCs by exposure to IL-3. The morphology and yields of IL-3 DCs and GM-CSF DCs were compared by scanning electron microscopy and laser scanning confocal microscopy. Immunohistochemistry and flow cytometer (FCM) were used to identify immune phenotypes. The results showed that IL-3 DCs and GM-CSF DCs both expressed the specific marker DEC-205 with about 80% and 70% purity, respectively. IL-3 DCs had similar morphology as plasma cells, but a different immune phenotype, namely, CD80(-), CD86(-), CD14(-), and MHC class II(+). IL-3 DCs remained in the costimulatory molecule-deficient state when TNF-alpha was supplemented into the culture. We therefore propose that IL-3 induces a high purity and yield of DCs from bone marrow. Since IL-3 DCs possess a tolerogenic phenotype (MHC class II(+), B7(-)), they may induce alloantigen-specific hyporesponsiveness in vitro.

Animals↗