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H Baatz

Publications and source records attributed to H Baatz.

At least 37 records · Page 2Linked to original sources
PubMed1996

[Apparent wall shear rate and leukocyte-endothelium interaction in iris blood vessels in endotoxin-induced uveitis].

UNLABELLED: Inflammatory stimuli induce the expression of adhesion molecules on leukocytes and endothelial cells. The adhesive forces between leukocytes and the vascular endothelium are antagonized by the shear stress of the flowing blood. The aim of this study was to examine how differences in the apparent wall shear rate measured in iris venules with varying caliber affect leukocyte-endothelium interaction. METHODS: The microvasculature of the iris in Lewis rats (n = 6) was examined using intravital fluorescence microscopy [2]. Blood flow was visualized with FITC-HES and leukocytes were stained with rhodamine 6G. Venules (n = 110) ranging in diameter from 20-60 microns were analysed with regard to the following parameters: Flux of leukocytes, velocity of leukocytes in the center stream, number of rolling and adherent leukocytes. The apparent wall shear rate was calculated from the center stream velocity and the vessel diameter. Animals were examined 4 h after administration of endotoxin from S. typhimurium (500 mg/kg body wt i.p.), when leukocyte-endothelium interaction is strongly enhanced. RESULTS: The flux of leukocytes, the absolute number of rolling leukocytes and the velocity of leukocytes in the center stream was higher in larger than in smaller venules. The apparent wall shear rate decreased with increasing vessel diameter. Calculated values were 806 +/- 59 s-1 for vessels 20-30 microns in diameter and 483 +/- 34 s-1 for vessels of 50-60 microns (mean +/- SEM). The number of adherent leukocytes per mm2 endothelial surface and the rolling fraction did not show significant differences between vessels with varying caliber. CONCLUSION: Although the shear rate declined with increasing vessel diameter, we could not observe an increase in rolling and adherent leukocytes. The effects of vessel diameter on leukocyte adhesion to the vascular endothelium in postcapillary iris venules are minimal.

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PubMed1995

In vivo study of leukocyte-endothelium interaction in endotoxin-induced uveitis.

PURPOSE: To analyze leukocyte-endothelium interaction in iris venules of living rats and to quantify changes of leukocyte dynamics in endotoxin-induced uveitis (EIU). METHODS: Lewis rats received an intraperitoneal injection of 100 micrograms of lipopolysaccharide (LPS; Salmonella typhimurium). Using intravital fluorescence microscopy, the iris vessels were examined, 2, 4, 6, 10, 14, 24, and 72 hours after LPS injection. A setup for intravital fluorescence microscopy of iris venules in the rat is described. Images are recorded with a video camera and stored on S-VHS videotape for off-line analysis. For contrast enhancement, erythrocytes and plasma were stained with fluorescein isothiocyanate (FITC) and FITC-hydroxyethylstarch, respectively. Rhodamine 6G was used for intravital staining of leukocytes. Resolution and magnification (x850) of the system facilitates observation of individual cells in the bloodstream in real time. Leukocytes were either flowing in the center stream, rolling along the endothelium, or firmly adherent. Image analysis provided data on microvascular leukocyte flux and leukocyte velocity. RESULTS: The percentage of leukocytes rolling on postcapillary venular endothelium increased significantly (P < 0.05) 4 hours after endotoxin administration, as did the number of firmly adherent cells. Leukocyte-endothelium interaction reached its maximum 6 to 10 hours before an increase of inflammatory cells in the aqueous humor. The response to endotoxin was reversible, subsiding to near-normal values after 72 hours. CONCLUSIONS: Intravital fluorescence microscopy provides data on microvascular parameters, including the number of rolling and sticking leukocytes on vascular endothelium. Inflammation of the anterior uvea was characterized with regard to leukocyte recruitment from blood to the vessel wall.

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PubMedDate not supplied

Thalidomide inhibits leukocyte-endothelium interaction in endotoxin-induced uveitis.

To investigate the effects of thalidomide on leukocyte-endothelium interaction in iris vessels of rats with an endotoxin-induced uveitis (EIU), intravital fluorescence microscopy was used to quantify leukocyte adhesion to the vascular endothelium of iris venules in Lewis rats at 2, 4, 8 and 24 h after induction of EIU. Animals (n = 84) received a single intraperitoneal dose of either thalidomide (80 mg/kg body weight) or prednisolone (10 mg/kg body weight). Both drugs significantly reduced firm adhesion of leukocytes at 4, 8 and 24 h. Thalidomide caused earlier suppression of leukocyte rolling than prednisolone (4 vs. 8 h). TNF-alpha plasma levels peaked at 2 h and were not significantly reduced in any group compared with controls. Cell count and protein concentration in aqueous humor were significantly reduced by prednisolone and thalidomide at 24 h (p < 0.05). Thalidomide exerts its anti-inflammatory effects by an inhibition of leukocyte-endothelium interaction. Compared with prednisolone, thalidomide shows earlier inhibition of leukocyte rolling, indicating modulation of adhesion molecule expression and/or function.

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PubMedDate not supplied

Effects of a new immunotherapeutic agent (CG5601) on endotoxin-induced uveitis.

CG5601 is a novel immunomodulatory substance showing anti-inflammatory properties comparable to thalidomide. To investigate the anti-inflammatory effects of CG5601 in endotoxin-induced uveitis (EIU) and to evaluate its influence on leukocyte-endothelium interaction, the anterior chamber inflammatory reaction was assessed and intravital fluorescence microscopy was carried out at 2, 4, 8 and 24 h. Lewis rats received an intraperitoneal injection of CG5601 (200 mg/kg b.w.) at the time of lipopolysaccharide injection. At 8 and 24 h, CG5601 inhibited the cell migration and protein concentration in the aqueous humor compared to untreated EIU (p < 0.0001). There was no significant difference between nontreated animals and vehicle controls. The treatment of CG5601 reduced the number of rolling leukocytes. At early time points (2 and 4 h), inhibition of rolling leukocyte flux was significant (p < 0.005). The rise of serum TNF-alpha levels in EIU at 2 h was reduced. CG5601 exerts potent anti-inflammatory effects in EIU.

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PubMedDate not supplied

Kinetics of white blood cell staining by intravascular administration of rhodamine 6G.

Rhodamine 6G is a vital dye accumulating in the mitochondria of cells. It is used in intravital fluorescence microscopy for contrast enhancement of white blood cells (WBC), enabling visualization of WBC in the microvasculature even at high center flow velocity. The aim of this study was to examine the kinetics of WBC staining after intravascular administration of rhodamine 6G in Lewis rats, Syrian golden hamsters and BALB/c mice. For this purpose, WBC were isolated from whole blood and the percentage of cells stained positively as well as their fluorescence intensity were measured by flow cytometry 5, 15, 30 and 60 min after dye administration. Injection of 0.06-0.2 mg/kg body weight of rhodamine 6G resulted in staining practically all granulocytes and monocytes over the entire observation period of 60 min. Fluorescence intensity of WBC was adequate to be detected in an experimental setup for intravital fluorescence microscopy in the hamster dorsal skinfold chamber. The degree of WBC staining was different in the species studied, yielding a higher percentage of stained lymphocytes in rats than in mice and hamsters. Staining of lymphocytes declined within 60 min after rhodamine application, the loss of fluorescent label being most pronounced in hamster cells. After 15-30 min, relative fluorescence intensity of stained lymphocytes had decreased considerably, indicating the need for reinjection of the dye or limiting microscopic analysis to approximately 15 min after rhodamine 6G administration. While the intravascular injection of rhodamine 6G results in adequate staining of granulocytes and monocytes, only a fraction of lymphoid cells are stained.

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PubMedDate not supplied

Band keratopathy: a modified treatment.

PURPOSE: The surgical treatment of band keratopathy usually consists of abrasion of the corneal epithelium followed by removal of the subepithelial calcium deposits by means of an ethylenediamine-tetraacetic acid (EDTA) solution. In order to reduce the discomfort and pain that occur after corneal abrasion, the authors developed a modified technique that avoids the abrasion of the epithelium. METHODS: In three patients (four eyes) with long-standing band keratopathy, the epithelium was detached with a 19% ethanol solution and placed gently toward the limbus, a method also used in laser-assisted subepithelial keratectomy (LASEK). After clearing the anterior stroma with EDTA solution, the epithelial flap is unrolled and a bandage contact lens applied. RESULTS: Postoperative pain was greatly reduced and after removal of the contact lens no pain was reported. CONCLUSIONS: This modified epithelium-sparing treatment of band keratopathy shows good results while reducing postoperative pain.

Calcinosis↗