Isabella Baumgartner

Treatment of non-healing skin ulcers with autologous activated mononuclear cells

The aim of this study was to investigate whether cultured autologous mononuclear cells (MNC) effectively initiate, accelerate and improve granulation and epithelialisation of skin ulcers. Thirty-three patients with chronic arterial occlusive disease (CAOD; n = 21) or venous post-thrombotic syndrome (PTS; n = 12) were treated with autologous MNC and compared with a control group of 30 patients who received tissue culture medium alone. Previous treatments had been unsuccessful for a mean of 9.23 (3-19) months. MNC were harvested from the peripheral blood of each patient by standard techniques, cultured for three days and applied to the ulcer twice a week. After 4.6 +/- 1.9 weeks, 29/33 ulcers were closed in the MNC group. Patients in the control group took 8.1 +/- 1.2 weeks for 17/30 ulcers. Thus ulcer healing was significantly speedier with MNC seeding; 48% of all ulcers were closed after 30 days of MNC treatment and 92% after 60 days. Patients with PTS responded significantly faster than patients with CAOD. In 90% of patients with painful ulcers MNC treatment resulted in pain relief, whereas in the control group only 50% of patients became pain-free.

Rapid Communication The Mydriatic Effect of Tropicamide and its Diagnostic Use in Alzheimer's Disease

The mydriatic effect of topically administered tropicamide was investigated as a possible diagnostic indicator for Alzheimers disease. Although an initial series seemed to show a correlation between hypersensitivity to tropicamide and intellectual impairment, subsequent testing showed a greater inter- and intra-individual variation than that between the normal group and the group of patients with intellectual impairment. This procedure seems, therefore, to lack sufficient specificity to be useful for such a diagnostic purpose.

Blepharitis — a diagnostic and therapeutic challenge

Over the last few years the number of patients with chronic bilateral blepharitis has increased dramatically. From January 1985 until the end of 1989, a total of 407 patients with this diagnosis underwent ophthalmological and dermatological investigations at our out-patient clinic. Keratoconjunctivitis sicca (KCS) in conjunction with blepharitis occurred in 14.5% of the patient population who also suffered from acne rosacea. A comparison of the spectrum of microorganisms that have previously been isolated from affected sites with data obtained in the present study revealed that the range of microorganisms associated with this chronic localized inflammation has apparently shifted in recent years. The prevalence of Staphylococcus aureus, which was considerable in the pre-antibiotic era, has markedly decreased, although a distinct entity of staphylococcal blepharitis seems to remain, either alone or in combination with seborrheic blepharitis (62.8% of our patients). The clinical picture, microbiological findings and therapy for this condition are presented.

Photoablation by UV and visible laser radiation of native and doped biological tissue

Photoablation studies of biological material (human cornea) with UV and visible laser light show that effective, apparently non-conventional thermal photoablation can be achieved by introducing energy absorbing dopants in the tissue. Previously unknown high ablation rates of 80 Gmm/pulse have been observed. The results allow one to clearly postulate different ablation mechanisms for increasing laser fluence. The results are compared with the photoablation rates observed with 193 nm UV laser light on undoped human cornea. Explosive desorption has been found the dominant process involved.

Expression of the VEP13 Antigen (CD16) on Native Human Alveolar Macrophages and Cultured Blood Monocytes

Human alveolar macrophages (AM phi) from thirteen patients, who were suffering from various lung diseases were harvested by bronchoalveolar lavage. Peripheral blood monocytes from eight healthy donors were isolated by Ficoll-Hypaque gradient centrifugation and adherence to plastic surface. To detect the VEP13 antigen (CD16) on these cells, a rosette assay employing ox erythrocytes coated by the CrCl3 method with purified VEP13 monoclonal antibody (Eo-VEP13) was used. A mean of 31.3% of freshly isolated AM phi and 3.9% of blood monocytes formed Eo-VEP13 rosettes. Monocytes cultured for 3 or 6 days in the presence of a supernatant from mouse L929 cells, which had been shown previously to improve long-term viability of human monocytes in culture, showed 12.5% and 25.3% Eo-VEP13 rosettes, respectively. No significant increase in VEP13 antigen expression was noted by culturing monocytes without L929 cell supernatant. The factor in L929 supernatant that induces VEP13 antigen expression has not been identified. Tunicamycin at 10 micrograms/ml inhibited significantly VEP13 antigen expression on monocytes. In contrast, IgG rosette formation was not reduced by tunicamycin. Our data show that subpopulations of native human AM phi and peripheral blood monocytes cultured in presence of a supernatant of L929 fibroblasts containing mainly murine CSF may express the CD16 antigen, which is normally found on large granular lymphocytes (LGL). Suppression by tunicamycin indicates that Fc receptor glycosylation takes place during a later differentiation step of mononuclear phagocytes.

HLA typing from human donor eyes

A method for HLA-ABC and HLA-DR typing of human donor eyes using pigmented retinal epithelial and uveal cells cultured in the presence of human recombinant γ-interferon is described.

Corneal Lathing Using the Excimer Laser and a Computer-controlled Positioning System

PURPOSE To present the excimer laser corneal shaping system (ELCS-S), an add-on device to the Keratom, a commercially available 193-nm excimer laser built by Schwind. METHODS The system is designed for the preparation of donor corneas under sterile conditions using the ultraviolet laser to offer greatest possible flexibility. Lenticules for planolamellar grafting and refractive epikeratoplasty, as well as donor buttons for penetrating keratoplasty can be computer-designed by the surgeon or technician and lathed with the system. RESULTS Using the excimer laser corneal shaping system (ELCS-S) on human donor corneas, the central surface of the epikeratoplasty lenticule exhibited only narrow, flat concentric notches corresponding to the single lathing steps. Transmission electron microscopy revealed a damage zone of less than 0.3 microm in close approximation to the treated surface. The final thickness revealed a difference of less than +/-53 microm from the intended, initially programmed value. Ultrastructural studies showed the perpendicular stromal surface of the penetrating keratoplasty buttons to be smooth with minimal protrusion of Descemets membrane. Endothelial injury was observed in a zone averaging between 40 and 100 microm adjacent to the cutting edge only. CONCLUSION The excimer laser corneal shaping system (ELCS-S) allows a computer-controlled, surgeon-designed, sterile preparation of lamellar and penetrating corneal grafts with the use of the excimer laser. This could offer significant advantages in comparison to presently available systems for lamellar dissection and trephination.

Expression of MHC Class II Antigens on Rat Bone Marrow Cells and Macrophages, and Their Modulation during Culture with Murine GM-CSF or M-CSF

Flow cytometric analysis employing MRC OX 6 and MRC OX17 monoclonal antibodies recognizing determinants on RT1.B or RT1.D molecules, equivalent to murine I-A and I-E, respectively, was used to detect rat MHC class II antigen (Ag) expression. Approximately 5% of freshly isolated rat bone marrow cells (BMC) expressed RT1.B and over 30% displayed RT1.D molecules. The RT1.D+ cells were W3/13+, OX 7+, OX 19- and OX 22-. After one week culture of BMC with murine recombinant granulocyte/macrophage colony-stimulating factor (GM-CSF), regardless of concentrations, 90 to 95% of the cells were scored as bone marrow-derived macrophages (BMDM phi), and over 30% expressed both RT1.B and RT1.D Ag. GM-CSF increases the percentage of BMDM phi bearing MHC class II Ag in a concentration-dependent manner. This effect seems to be specific because antibodies to interferon-gamma, tumor necrosis factor-alpha or interleukin-4 did not reduce the number of cells expressing RT1.B and RT1.D Ag. Furthermore, GM-CSF was able to trigger expression of class II molecules on rat peritoneal macrophages (M phi) and BMDM phi resulted from cultures of BMC with mouse M phi-CSF (M-CSF), and the RT1.B and RT1.D inducing effect of GM-CSF was opposed by M-CSF, and by anti-GM-CSF antibodies. The induction of MHC class II Ag synthesis by GM-CSF on rat BMDM phi was confirmed at the mRNA level by Northern blot analysis employing cDNA probes encoding the RT1.B alpha.

Die Herstellung von hochpräzisen Transplantaten für die lamellierende Keratoplastik und von Epikeratophakie-Lentikeln mit Hilfe des Excimer-Lasers bei 193 nm und eines computergesteuerten Positioniersystems

ZusammenfassungEs wird ein neues System vorgestellt, welches es ermöglicht, mittels Laserablation aus Spenderhornhäuten Lentikeln für die aphake und myope Epikeratophakie sowie für die lamellierende Keratoplastik herzustellen. Unter Verwendung eines computergesteuerten Positioniersystems wird die Spenderhornhaut in einem fokussierten Excimer-Laserstrahl (ArF, 193 nm) bewegt. Der hier verwendete Photoablationsprozeß ermöglicht eine effektive Abtragung mit Schädigungszonen kleiner 0,3 um im Gewebe, das die Abtragezone umgibt.Die Computersoftware ermöglicht eine benutzerfreundliche Auswahl verschiedenster Parameter, so wie den Durchmesser der optischen Zone, die Form der Randzone, die Brechkraft, die zentrale und minimale Dicke sowie die Umrißform des Transplantates.Es werden Daten über die Stabilität der Hornhautdicke während des Bearbeitungsprozesses sowie eine Methode zur Kontrolle der Qualität und Reproduzierbarkeit des Ablationsprozesses unter Verwendung von PMMA-Scheiben präsentiert. Histologische und elektronenmikroskopische Ergebnisse von Lentikeln, die mit dem „Excimer-Laser-Corneal Shaping System“ hergestellt wurden, werden gezeigt.SummaryA new system is presented for variable laser-ablation of donor corneas into lenticules used for aphakic and myopic epikeratophakia, as well as for lamellar keratoplasty. With the help of a computer-controlled positioning system using high-precision micropositioning elements the donor cornea is moved in a holding device in front of a focused excimer laser beam (ArF, λ = 193 nm). This photo-ablation lathing process is known to cause a damage zone of less than 0.3 urn which assures an optimal viability of the stromal cells in close approximation to the treated surface.The computer software allows the fast and convenient selection of a variety of parameters, such as the diameter of the optical zone, the shape of the wing zone, the refractive power, the central and the minimal thickness, and the overall contour of the lenticule. The selection of parameters for lamellar transplantation encompasses not only the thickness of the graft but also the overall configuration using a scanning device for selection of the shape and size.Laboratory data on the stability of the corneal thickness during the lasing process, as well as a method for quality control and reproducibility of the ablation using PMMA discs are presented. Furthermore, histological and electron microscopical results of lenticules prepared from human donor corneas with this “Excimer-Laser Corneal Shaping System” are shown.

Mechanisms of Laser Ablation of Biological Tissue

The application of laser ablation for tissue removal - mostly in the UV-regime - has recently stimulated considerable experimental efforts among research groups. Beyond this, clinical applications of laser ablation have already been reported. An understanding of the desorption and ablation mechanisms and potential side effects of the radiation is, however, still in at the infant stage, but indispensable for a useful and responsible application.