Search PubMed⌕ Search

Biomedical subjects

H Lindner

Publications and source records attributed to H Lindner.

At least 37 records · Page 2Linked to original sources
PubMed1995

[Contrast sensitivity of visually handicapped patients].

The contrast sensitivity of 41 patients with low visual acuity, as a result of age-related maculopathy, diabetic retinopathy or open-angle glaucoma, in most of them, was studied by means of the VISTECH test and the Buser LCS-test. The VISTECH test revealed reduced contrast sensitivity, especially at high frequencies. This reduction was marked in patients with diabetic retinopathy. Contrast on the color TV monitor was adjusted by the subjects. Yellow and green monitors were chosen equally often by the patients. A positive contrast (black text with light background) was preferred. The contrast required was noticeably higher than that required by subjects with normal eyes.

Adolescent↗
PubMed1994

Use of powdered cellulose for the production of pellets by extrusion/spheronization.

The use of powdered cellulose instead of microcrystalline cellulose in the extrusion/spheronization process was investigated. The aim of the study was to assess differences between two types of powdered cellulose using a 2(4-1) fractional factorial design. Water content and amount of binder were found to be most important while type of cellulose and screw speed had only negligible influence on the extrusion process and the resulting pellets. Pellets obtained with powdered celluloses showed higher porosities and faster dissolution rates compared with those made with microcrystalline cellulose. Image analysis was found to be an appropriate method for the simultaneous characterization of pellet size and shape.

Cellulose↗
PubMed1994

The power-consumption-controlled extruder: a tool for pellet production.

Based on the assumption that there is a link between power consumption of an extruder and pellet properties, a control circuit for power consumption was developed. Powder and granulation liquid are fed separately into a twin-screw extruder. The power consumption is controlled by varying the pump rate at a given powder-feed rate; consequently each level of power consumption results in a specific water content of the extrudate for a particular formulation. The shape of pellets depends almost entirely on the level of power consumption irrespective of formulation. The size of dry pellets is additionally affected by a shrinking factor which depends on the water content. The power-consumption-controlled extruder is an appropriate tool for the production of pellets. The system is able to adapt the water content for a formulation automatically.

Cellulose↗
PubMed1994

[Asthenoptic complaints in conjunction with illumination by gas discharge lamps].

Asthenopic complaints frequently occur when visual requirements are high in conjunction with illumination by gas discharge lamps. Four causes should be considered: level of the vision task, quality of light (spectral distribution, fluorescent flicker), quality of illumination, individual characteristics of the affected subject. Of 3000 patients, 58% had asthenopic complaints when exposed to gas discharge lamps. The number of females was twice that of males. The subjects affected were predominantly women, aged 20-30 years, who exhibited autonomic lability. Also, they showed reduced concentration power, diminished binocular and stereo vision, and more than normal photic driving findings in the EEG. Fluorescent flicker exerted no influence on elementary visual power, concentration power visuomotor performance, or optical reaction time. It did have an effect on dynamic visual acuity, flicker frequency, blinking rate, and the demands experienced. Fluorescent flicker should be reduced, e.g., by three-phase connection or electronic ballasts. Correcting the binocular vision and reducing the individual glare sensitivity are approaches indicated for individual therapy.

Adult↗
PubMed1993

G1- and S-phase synthesis of histone H1 subtypes from mouse NIH fibroblasts and rat C6 glioma cells.

The rates of synthesis of histone H1 subtypes in synchronized mouse NIH 3T3 fibroblasts were compared with those of rat C6 glioma cells during the G0, G1, and S phases by using a combination of HPLC techniques and conventional gel electrophoresis. In the mouse cell line, all H1 subtypes, H1a-H1e including histone H1(0), were detectable. In the rat cell line, however, no histone H1a was found. H1c and H1e from both cell lines show in the quiescent state a relatively high specific activity comparable with that of H1(0). After release from the G0/G1 block, the synthesis of H1(0) and likewise that of H1c and H1e increase for a short period. All H1 subtypes have their maximum specific activity at the same time after stimulation. The percentage of total H1 specific activity of H1a, H1b, and H1d increases, those of H1c and H1e remain relatively constant, and that of H1(0) decreases while cells cycle from the G0/G1 to the S phase. These findings support our assumption that H1 subtypes could be classified into three groups with common metabolic characteristics: one consists of H1a, H1b, and H1d; another of H1c and H1e; and a third of H1(0) histone. Moreover, the corresponding H1 subtypes from two different species seem to have similar specific activities during the G1 and S phases.

3T3 Cells↗
PubMed1993

[Treatment of recurrent neuroblastoma in childhood with whole body thermochemotherapy].

More than 30% of the children suffering from an advanced solid tumour disease or tumour recurrence cannot be cured despite intensive oncological treatment. A new possible therapy is the application of whole-body hyperthermia in childhood in combination with chemotherapy and radiation treatment. The fundamental principles and the method of the whole-body thermochemotherapy are briefly explained. The treatment of one patient with a neuroblastoma recurrence is reported as a clinical example for the effectiveness of whole-body thermochemotherapy in childhood and the course of therapy is discussed.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1992

Alteration in proportions of histone H1 variants during the differentiation of murine erythroleukaemic cells.

We have investigated the changes in the relative amounts of histone H1 zero and all five H1 variants during the differentiation in vitro of Friend erythroleukaemic cells. Three different agents were used as inducers of differentiation: dimethyl sulphoxide, hexamethylenebisacetamide and sodium butyrate. By applying a combination of reverse-phase h.p.l.c. and one-dimensional gel electrophoresis we observed that, during differentiation in vitro, (1) the relative amount of each subtype changes upon induction and that (2) dimethyl sulphoxide and hexamethylenebisacetamide produce a similar histone H1 pattern with a strong increase in histones H1 zero and H1c, a modest increase in histone H1e and a decrease in the relative amounts of histone H1a, H1b and H1d, whereas butyrate induces a different pattern, particularly with respect to both histones H1c and H1e: H1c increased slightly, and H1e strongly, during differentiation. These results are compared with changes in the histone H1 pattern during differentiation in vivo in the mouse [Lennox & Cohen (1983) J. Biol. Chem. 258, 262-268] and in the rat [Pina, Martinez & Suau (1987) Eur. J. Biochem. 164, 71-76], and similarities and deviations are discussed.

Acetamides↗
PubMed1992

Specificity of Zea mays histone deacetylase is regulated by phosphorylation.

Mono Q ion exchange high performance liquid chromatography (HPLC) reveals that the main histone deacetylase activity (HD1) of germinating Zea mays embryos consists of multiple enzyme forms. Chromatography of HD1 after treatment with alkaline phosphatase yields two distinct histone deacetylase forms (HD1-A, HD1-B). The same is true for chromatography after phosphatase treatment of a total cell extract. One of these enzyme forms (HD1-A) is subject to phosphorylation, which causes a change in the substrate specificity of the enzyme, as shown with HPLC-purified individual core histone species; the substrate specificity for H2A increases more than 2-fold after phosphorylation, whereas the specificity for H3 decreases to about 60%. The total histone deacetylase activity is quantitatively released from isolated nuclei after extraction with moderate ionic strength buffers; no significant residual enzyme activity could be detected in the nuclear matrix.

Animals↗
PubMed1992

Separation of phosphorylated histone H1 variants by high-performance capillary electrophoresis.

High-performance capillary electrophoresis (HPCE) was used to separate successfully distinct phosphorylated derivatives of individual histone H1 variants. With an untreated capillary (50 cm x 75 microns I.D.) the electrophoresis was performed in about 15 min. Inconvenient interactions of these highly basic proteins with the capillary wall were eliminated by using 0.1 M sodium phosphate buffer (pH 2.0) containing 0.03% hydroxypropylmethylcellulose. Under these experimental conditions the histone H1 variants H1b and H1c obtained from mitotic enriched NIH 3T3 fibroblasts and isolated by reversed-phase high-performance liquid chromatography were clearly separated in their non-phosphorylated and different phosphorylated forms. This result was confirmed by acid-urea gel electrophoresis, comparison with non-phosphorylated histones H1b and H1c, isolated from quiescent NIH 3T3 cells, and incubation of multi-phosphorylated histone H1b with alkaline phosphatase and subsequent acid-urea and capillary electrophoresis. The results illustrate that the application of HPCE to the analysis of histone modifications provides a new alternative to traditional gel electrophoresis.

Alkaline Phosphatase↗
PubMed1992

High-performance capillary electrophoresis of core histones and their acetylated modified derivatives.

By using high-performance capillary electrophoresis, we have successfully separated rat liver core histones into several subfractions. Inconvenient interactions of the highly basic proteins with the capillary wall were eliminated by a phosphate buffer system containing 0.03% hydroxyprophylmethylcellulose. Sample amounts of a few nanolitres were analysed within about 20 min. Multiacetylated histones H4 and H3 from induced Friend erythroleukaemic cells prepurified by h.p.l.c. were clearly separated into their non-acetylated and distinct acetylated forms. Our results illustrate that the application of capillary zone electrophoresis on its own or in combination with h.p.l.c. to the analysis of histones provides an important new alternative to traditional gel electrophoreses.

Acetylation↗
PubMed1992

Enzymes involved in the dynamic equilibrium of core histone acetylation of Physarum polycephalum.

DEAE-Sepharose chromatography of extracts from plasmodia of the myxomycete Physarum polycephalum revealed the presence of multiple histone acetyltransferases and histone deacetylases. A cytoplasmic histone acetyltransferase B, specific for histone H4, and two nuclear acetyltransferases A1 and A2 were identified; A1 acetylates all core histones with a preference for H3 and H2A, whereas A2 is specific for H3 and also slightly for H2B. Two histone deacetylases, HD1 and HD2, could be discriminated. They differ with respect to substrate specificity and pH dependence. For the first time the substrate specificity of histone deacetylases was determined using HPLC-purified individual core histone species. The order of acetylated substrate preference is H2A much greater than H3 greater than or equal to H4 greater than H2B for HD1 and H3 greater than H2A greater than H4 for HD2, respectively; HD2 is inactive with H2B as substrate. Moreover histone deacetylases are very sensitive to butyrate, since 2 mM butyrate leads to more than 50% inhibition of enzyme activity.

Acetylation↗
PubMed1992

Premenstrual symptoms: the role of irrational thinking.

104 women, between the ages of 18 and 45 years, were surveyed to investigate the relationship between premenstrual symptomatology, as measured by the Modified Menstrual Distress Questionnaire, and irrational thinking, as measured by the General Attitude and Belief Scale. The women who reported greater premenstrual symptomatology also reported significantly higher scores in the "need for comfort" irrationality subscale. This indicated that these women had particular difficulty dealing with hassles and the resulting feelings of tension and irritability in the premenstruum. It was suggested that the absence of significant effects for other rationality-irrationality subscales could be associated with testing at different times during the menstrual cycle. Irrationality, like other conditions (such as anxiety and depression) prevalent in the premenstruum, could change in intensity across phases of the menstrual cycle.

Adult↗
PubMed1992

[Morphology and therapy of tracheal cysts].

Following a short representation of etiology, morphology and classification of cysts of trachea the symptoms, diagnosis and therapy were described. 7 cases of the own patients material in 27 years are presented extensively.

Bronchogenic Cyst↗
PubMed1991

[Radiotherapy of small cell bronchial cancer].

In the combined modality treatment of the small carcinoma of the lung chemotherapy is obligatory. Radiotherapy plays a decisive role, especially in limited disease tumors. Numerous randomized studies show that the rate of locoregional recurrence is reduced, whereas the survival rate is raised by the irradiation of the thorax. Dose size, target volume, fractionation as well as adaptation to the chemotherapy regimes are still a matter for discussion. In extensive disease stage, radiotherapy generally plays a role only as a palliative treatment modality. Undoubtedly, the prophylactic cranial irradiation diminishes the frequency of brain metastases. Regarding the potential neurological late toxicity we must carefully pay attention to the dosage, the fractionation, and the indication to this treatment. Half and total body irradiation only should be considered in prospective studies.

Carcinoma, Small Cell↗
PubMed1990

[A basic psychodiagnostic program for internists].

The increasing frequency of disturbances of the health, in which psychic and/or social influential factors are significant, reflects also in the number of patients of the specialist of internal medicine who is working in the outpatient department, the hospital and in a subspeciality. This requires from the specialists of internal medicine, if he will satisfy the claims of his patients for a comprehensive diagnostics and effective therapy, from the very beginning and in all phases of the care the involvement of a basic psychodiagnostics. Hereby the problem in question is an enhanced internal establishment of the anamnesis under psychodiagnostic aspect, which serves for the clarification of psychic and/or social influences on signs and symptoms, the experience of the and the course of the disease. An orientating systematization and a way to the positive diagnostics of neuroses, psychosomatic diseases or disturbances and further functional syndromes in the field of internal medicine are presented which demand the graduated psychotherapeutic measure.

Humans↗
PubMed1990

Separation of rat tissue histone H1 subtypes by reverse-phase h.p.l.c. Identification and assignment to a standard H1 nomenclature.

H1 histones from rat liver and rat testis were separated by reverse-phase h.p.l.c. Within 40 min six subfractions (H1(0), H1b, H1a, H1d, H1e + H1c and H1c) and seven subfractions (H1(0), H1b, H1a, H1d, H1e + H1c, H1c and H1t) respectively were isolated by using a linear acetonitrile gradient. Each individual H1 subtype was identified either by comparing the H1 variants (contained in both tissues but in different quantities) or by SDS/PAGE and acetic acid/urea/PAGE. Moreover, all H1 variants were characterized by amino acid analyses. The amino acid compositions of rat histone subfractions H1(0), H1b and H1e were determined for the first time. It was possible to classify unambiguously the H1 subfractions obtained by h.p.l.c. by following the standardized H1 nomenclature for electrophoretic systems recommended by Lennox, Oshima & Cohen [(1982) J. Biol. Chem. 257, 5183-5189]. Incorrect assignments that have been made in various publications are discussed.

Acetates↗
PubMed1990

Autoantibodies against different histone H1 subtypes in systemic lupus erythematosus sera.

The H1 histones represent the most heterogenous class of histone proteins. In this study, we analyzed the specificity of human antibodies against 6 H1 subtypes. H1 histones from rat organs were separated by reverse-phase high performance liquid chromatography and used as antigens in immunoblotting experiments. Sera containing anti-histone H1 antibodies were obtained from patients with systemic lupus erythematosus. Of the 9 sera tested, 2 reacted with only 1 H1 subtype. The other sera recognized different combinations of H1 subtypes. Only 1 serum reacted with all 6 H1 subtypes. Histones H1.5 and H1.1 were the subtypes most frequently recognized by the human autoantibodies. Our data indicate that human anti-H1 antibodies represent a heterogenous population, directed mainly against epitopes localized in the variable region of the H1 molecule.

Antibody Specificity↗