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Biomedical subjects

L Hesse

Publications and source records attributed to L Hesse.

71 records · Page 4Linked to original sources
PubMed1994

[Computer-assisted, improved evaluation of Comberg images with three-dimensional graphic reconstruction].

BACKGROUND: Small metallic foreign bodies may easily be identified by conventional x-ray. The Comberg shell is a useful tool to discriminate between extra-respectively intraocular localization of the foreign body. However, poor results are common when evaluating the x-ray films. METHODS: We have improved evaluation of the radiographs by means of a program for a personal computer, regarding the following aspects: To avoid errors of measurement the relevant points of the radiograms are read by a digitizer-tableau. The different projection failure of the lateral respectively posteroanterior x-ray is calculated separately. For the calculation of the modell the true axial length of the eye is considered. CONCLUSION: A three dimensional image from varying points of view gives an instructive impression of the foreign body and its relation to structures of the eye. Handling of the presented computer program is easy. It standardizes analysis of the Comberg radiograms.

Computer Graphics↗
PubMed1994

[Systematic search of the posterior vitreous cortex during vitrectomy. Technique, complications and results].

We present the results of a prospective study trying to answer the question: when a clinical or echographic premacular vitreous detachment occurs, is it still possible to find a preretinal membrane at the surface of retina? We looked for such a membrane in 50 consecutive vitrectomies for various indications. We found and removed such a membrane in 42 cases but were unable to obtain histological examinations. Our conclusions are: most of the time, the diagnosis of total vitreous detachment is very difficult and the finding of a premacular membrane during vitrectomy is a frequent event.

Adolescent↗
PubMed1993

Improved method for autoradiographic localization of beta-adrenoceptors using photoaffinity labelling.

Contact autoradiography of tissue sections, using emulsion coated coverslips or X-ray films, is widely used to provide information about the regional distribution of receptors. This easy to perform, standard technique has the disadvantage of an image spread due to the gap between the radioactive source and the film. The present study describes a new technique which combines photoaffinity labeling of beta-adrenoceptors with "dipping" autoradiography and a modified trichrome stain. Incubation of 16 microns cryosections of rat lung tissue with the iodinated, photoaffinity labeling, non-selective, beta-adrenergic agonist [125I]-cyanopindololazide II ([125I]-CYPA II) (100 pmol/l) in the absence or presence of 1 mumol (+/-)-propranolol revealed strong, specific beta-adrenoceptor binding to alveolar parenchyma and bronchial epithelium of large and small bronchioles, lesser binding to smooth muscle bundles of large airways and only sparse binding to the smooth muscle of small bronchioles or peripheral branches of pulmonary artery. With standard autoradiographic techniques, a similar distribution of the label was obtained, although resolution and sensitivity were inferior. Staining of tissue sections through the photoemulsion by means of a modified Mallory's trichrome dye facilitated the discrimination between alveolar and bronchial epithelium, muscular and collagenous tissues. In conclusion, the photoaffinity labeling of beta-adrenoceptors with [125I]-CYPA II allows the use of "dipping" autoradiography. This technique, in combination with trichrome staining through the photoemulsion, results in an improved autoradiographic image together with a better association of the label with distinct histological structures and the higher sensitivity of the method.

Affinity Labels↗
PubMed1993

Simulation of the growth pattern of the central retinal artery using a fractal modeling technique.

Assisted by computer, we simulated the typical growth pattern of the central retinal artery by a fractal modeling technique. When processing was started with two fertile sides, an iterative processing function generated a ramiform fractal. The branching angle was chosen at random within a certain range. In addition, a feedback restriction forbade any intersection of branches. We demonstrated that the curved shape of the temporal vessels is caused by simultaneous growth of the vessels and the retina. When processing was begun with only one fertile side, the typical vascular pattern of a retinal coloboma was designed.

Computer Simulation↗
PubMed1992

[PC software for evaluating the Farnsworth-Munsell 100-Hue test].

This computer program is designed for faster elaboration of the Farnsworth-Munsell 100-Hue test. It is thus made user friendly, in that faultless input of data can be achieved, even by an untrained person. Evaluation is facilitated by the opportunity of representing two results at the same time. Examples of typical colour vision deficiencies are stored in a file and can then also be called up. Storing the results in a special data file helps to avoid the time consuming printing process. However, a hardcopy is supported by storing the last grafic in a standard PostScript-file, thus giving easy access to any printer. This program is applicable for IBM- or compatible PCs. Extensive use is possible by means of a software interface with the wide spread database-system DBASE.

Color Perception Tests↗
PubMed1984

Phenol-soluble nonhistone chromatin proteins in chronic lymphocytic leukemia.

The altered gene expression seen in cancer could relate to differences in nonhistone chromatin proteins between normal and malignant tumor cells. Phenol-soluble nonhistone chromatin proteins were isolated from human normal and leukemic (chronic lymphocytic leukemia) B-cells, as well as long-term cultured human B-lymphocyte cell lines. High-resolution two-dimensional electrophoretic maps identified a group of three nuclear proteins with a molecular weight of 45,000 to 50,000 and an isoelectric range of 4.5 to 4.7, which were associated only with the human leukemic B-cells. Leukemic B-cells and cultured B-cell lines also expressed a variant form of nuclear actin and tubulin.

B-Lymphocytes↗
PubMed1982

Defective expression of DR antigens in chronic lymphocytic leukemia.

HLA-DR (or Ia-like) antigens which were detergent-solubilized from plasma membranes of leukemic cells of patients with chronic lymphocytic leukemia of the B cell variety were purified by gel filtration, followed by affinity chromatography on Con A-Sepharose. After radioiodination, the DR antigens were immunoprecipitated with specific antisera and analyzed by two-dimensional gel electrophoresis. Repeated mapping revealed several different patterns of DR antigen expression. Most patients (18 out of 42) gave map patterns resembling those obtained from normal peripheral blood B cells. Such maps revealed light (27 kDa) and heavy (33 kDa) DR chains as well as a non-dissociated 60 kDa DR complex. All components, and especially DR light chains, were polymorphic and could be resolved further into several characteristic isoelectric variants. Maps from eleven patients showed decreased levels of 33 and 60 kDa antigen components, while eleven further patients expressed only DR light chains. Two patients lacked detectable DR antigens. Sequential mapping of individual patients indicated that expression of 33 and 60 kDa DR components fluctuates over months. This temporal fluctuation was independent of other B cell markers, including a newly defined group of surface membrane proteins of 28 000 daltons. The patterns are reminiscent of the biochemical dedifferentiation characteristic of immunoglobulin biosynthesis seen in the plasma cell dyscrasias.

Epitopes↗
PubMedDate not supplied

[Retinal necrosis after blunt bulbus trauma].

BACKGROUND: Acute retinal necrosis is a rare complication of blunt eye injury. We report about a patient with this type of retinal break. PATIENT: A 20-year-old male was referred to our hospital after a blunt injury of his left eye due to a ball. Visual acuity was 1.0 and the anterior segment was completely normal. A large retinal necrosis surrounded by a Berlin edema was present in the upper temporal part of the globe. A partial retinal detachment was present. The retina reattached within two weeks without further treatment and a characteristic granular hyperpigmentation developed. The edge of the retinal break was treated by photocaogulation. CONCLUSION: The affected patient was young and had a solid vitreous, providing internal tamponade of the retina in spite of a large retinal break. In these patients, the clinical course of an acute retinal necrosis after blunt injury should be waited for. However, a retinal detachment that persists after retinal edema disappeared is caused by pathologic vitreous changes and requires surgical treatment.

Adult↗
PubMedDate not supplied

Successful treatment of acute subretinal hemorrhage in age-related macular degeneration by combined intravitreal injection of recombinant tissue plasminogen activator and gas.

Subretinal hemorrhage secondary to age-related macular degeneration (AMD) has a poor visual prognosis. Surgical drainage of the blood improves visual acuity only in selected patients. We report on two elderly patients with spontaneous subretinal hemorrhage from AMD. In one eye, recombinant tissue plasminogen activator (rTPA), combined with a long-acting gas (SF6), was injected into the vitreous cavity. The other eye was treated first by gas instillation followed 3 days later by rTPA injection. Both treatments led to nearly complete displacement of the subretinal hemorrhage from the macular region. In both eyes, an inferior exudative retinal detachment reabsorbed spontaneously within 2 weeks. Bilateral vitreous opacities after rTPA injection resolved without further treatment. Postoperative visual acuity increased to 0.3 and 0.4. The combined treatment is a valuable method for management of acute subretinal hemorrhage. Rapid displacement of this abnormality can minimize clot-induced damage of the highly sensitive macula and increase visual acuity.

Aged↗