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Biomedical subjects

G Lange

Publications and source records attributed to G Lange.

At least 109 records · Page 6Linked to original sources
PubMed1984

IgG rheumatoid factors and cryoglobulins in mice bearing the mutant gene lpr (lymphoproliferation).

The autosomal recessive mutant gene, lpr (lymphoproliferation), produces a massive proliferation of T cells in autoimmune MRL mice. Since the MRL strain bearing the lpr mutation is the only strain that spontaneously develops high titers of rheumatoid factors (RF), we have investigated whether non-autoimmune mice (C57BL/6, C3H/HeJ and AKR) bearing the lpr gene could produce RF. Serum levels of RF activity were assessed by a new radioimmunoassay, in which serum samples pretreated with acetate buffer were incubated with 125I-mouse IgG and precipitated with 7% polyethylene glycol. The majority of serum from 4- to 6-month-old non-autoimmune strains of mice bearing the lpr gene exhibited significant RF activity, as did MRL-lpr/lpr mice. Sucrose density-gradient analysis has revealed that all the IgG RF activity was present in a form of immune complexes, sedimenting in the intermediate position (7-19S) and fully dissociable into 7S IgG under an acid condition. This indicates that the production of IgG RF does not require a particular background genome of the MRL strain. In addition, mice bearing the lpr mutation developed extremely large amounts of cryoglobulins, which paralleled the production of RF. Analysis of components of their cryoglobulins revealed a marked enrichment of IgG3 subclass as compared to other IgG subclasses and IgM. These results suggest that IgG3-containing immune complexes represent the major source of cryoglobulins occurring in mice bearing the lpr gene.

Animals↗
PubMed1984

[The Rostock artificial heart--current status and perspectives].

The authors report on their experiences gained by animal experiments (calf) and their attempts (human corpses) concerning adaptation of the apparatus to the human thorax. At the present time they do not see a chance for its routine clinical use. The main reason why is the impossibility to install the extrathoracic driving system into the thoracic cage and last not least the wear of the material used for the heart chambers.

Animals↗
PubMed1984

[Transseptal surgery of the sellar region from the neurosurgical viewpoint].

The indication for the transsphenoidal procedure in tumors of the sellar region is being presented. The authors prefer the transseptal - transsphenoidal approach after cut in the orifice of the nasal cavity. ENT-surgeon and neurosurgeon perform the operation together. Advantages and disadvantages as well as the necessity of the transfrontal operation on the one hand and the transnasal approach on the other hand are discussed. There were no severe complications in the cases jointly operated on and thus confirmed the results established by other authors.

Humans↗
PubMed1983

Quantitative determination of monosubstituted guanidines: a comparative study of different procedures.

Analysis of N2-acyl arginine derivatives as well as of arginine analogs lacking in alpha-amino function by Weber's modification of the Sakaguchi procedure yielded colored complexes with absorbance values approximately twice that obtained with an equivalent concentration of unmodified arginine. The limitations concerning the applicability of the various modifications of the Sakaguchi procedure as well as of the fluorimetric assay to the quantitative estimation of a variety of monosubstituted guanidines and proteins are discussed.

Arginine↗
PubMed1983

Hormonal profile and glucose tolerance in late pregnancy and postpartum.

Oral glucose tolerance, plasma insulin and basal levels of glucagon, hGH, hPRL, hPL, TSH, T4, T3, thyroxine-binding globulin (TBG), cortisol, corticosteroid-binding globulin (CBG) and estriol were measured in 23 normal pregnant women in late gestation (31 +/- 0.4 weeks of pregnancy). Twelve of these subjects could be re-examined 14 +/- 2 weeks postpartum. Blood glucose was lower basal and after glucose load (100 g) in the pregnant group. Fasting plasma insulin and glucose-induced insulin release were higher in pregnancy. The insulinogenic index and the beta cell response were significantly greater antepartum, while peripheral insulin activity was unchanged. The insulin:glucagon ratio as well as TSH and hGH showed no significant differences between ante- and postpartum values. However, T4, T3, TBG, cortisol, CBG, estriol, hPRL and hPL were significantly higher during gestation than after delivery. T4:TBG and T3:TBG ratios were much lower antepartum, while the cortisol:CBG ratio was comparable ante- and postpartum. To our knowledge this is the first report in which such an extensive hormonal and metabolic analysis was performed in the same women ante- and postpartum. It could be shown that glucose tolerance is not worsened during pregnancy in healthy subjects. The higher gestational insulin values are discussed with respect to the various significant hormonal changes.

Blood Glucose↗
PubMed1982

Antigenicity of elastin: characterization of major antigenic determinants on purified insoluble elastin.

This investigation reports a systematic comparison of antibody responses to well-defined fragments of mature, insoluble elastin in order to identify antigenic regions of the molecule. Antiserum to insoluble elastin was used to screen by radioimmunoassay the serologic activity of elastin peptides purified from a thermolysin digestion of insoluble elastin. Fractions with positive antigenicity were characterized by amino acid analysis and protein sequence analysis. Our results indicate that antigenic determinants on elastin can be classified functionally into two categories: major determinants related to the cross-linking domain which show cross-reactivity between species and limited, species-specific determinants in non-cross-linked regions of the molecule.

Animals↗
PubMed1982

[Experiences with the Rostock artificial heart].

A totally artificial heart--the Rostock totally artificial heart (Rostock TAH) was implanted in calves. We can give the following deductions after 27 examinations: -- The Rostock TAH was tested successfully in endurance test about 7 months; it show no sign of wear. -- The surgical technique of the implantation was standardised and a successful experimentation is possible. -- The longest survival time was 15 days. The hemodynamic early results were very good in 3 other animals. -- Modifications of the Rostock TAH were taken up relating to the dimensions of the artificial ventriculi and by mounting a screw cap for avoiding an air embolism. -- Adaption tests in the corpse show that the present form of the artificial heart is not ideal for a possible application in man. -- The problem is still existing in developing a suitable drive system locates intrathoracically. The present drive and control system on a pneumatic base is qualified only for the animal experiment but not for a possible application in man.

Anesthesia, General↗
PubMed1981

Study organization, recall organization, and free recall in reflective and impulsive children.

Relationship between measures of children's study organization, recall organization and free-recall proficiency were investigated. First- and fourth-graders (total N = 94 boys and girls) having reflective and impulsive conceptual tempos performed a sorting-recall task. Although older and reflective children showed high levels of recall and clustering in recall, age and conceptual tempo differences were reduced substantially when recall and clustering means were adjusted for variation in the deliberateness and ease with which Ss derived sorting organizations for to-be-recalled stimuli at study. The results were discussed in reference to study-deficiency and retrieval-deficiency hypotheses of age differences and individual differences in children's post-sort recall performance.

Child↗
PubMed1981

Elastin synthesis by ligamentum nuchae fibroblasts: effects of culture conditions and extracellular matrix on elastin production.

Fetal bovine ligamentum nuchae fibroblasts maintained in culture synthesized soluble elastin but were unable to form the insoluble elastic fiber. Secreted elastin precursors accumulated in culture medium and were measured using a radioimmunoassay for elastin. When elastin production was examined in ligament tissue from fetal calves of various gestational ages, cells from tissue taken during the last trimester of development produced significantly more elastin than did cells from younger fetal tissue, with maximal elastin synthesis occurring shortly before birth. Soluble elastin was detected in ligament cells plated at low density until proliferation began to be density inhibited and the cells became quiescent. Also, soluble elastin production per cell declined with increasing population doubling or with age in culture. Cells grown in the presence of 5% fetal calf serum produced approximately four times as much soluble elastin as cells grown in serum-free medium. The addition of dexamethasone (0.1 microM) and bleomycin (1 microgram/ml) increased soluble elastin production by cultured cells 180% and 50%, respectively, whereas theophylline (5 micrograms/ml) depressed production 50% and antagonized stimulation by dexamethasone. Ascorbate (50 micrograms/ml), soybean trypsin inhibitor (1 mg/ml), insulin (100 microunits/ml), and aminoacetonitrile (50 micrograms/ml) had no effect, but cycloheximide at 10(-4) M completely inhibited soluble elastin production. In contrast to cells in culture, ligament tissue minces (ligament cells surrounded by in vivo extracellular matrix) efficiently incorporated soluble elastin precursors into insoluble, cross-linked elastin. In addition, soluble elastin production per cell (per microgram of DNA) was higher in tissue minces than elastin production by cells maintained on plastic. These results suggest a role for extracellular matrix in formation of the elastic fiber and in stabilizing elastin phenotypic expression by ligament fibroblasts. Fibroblasts from the bovine ligamentum nuchae present an excellent model for in vitro studies of elastin biosynthesis.

Animals↗
PubMed1981

Human antibodies against antigens of the sparrow, blackbird, weaver finch, canary, budgerigar, pigeon and hen using the indirect immunofluorescent technique.

Detection of antibodies against various birds, particularly against exotic birds, can be facilitated using the sensitive immunofluorescent technique on avian fixed-intestine cryostat sections. Different fluorescent patterns corresponding to different human anti-avian antibodies have been observed. Sixty of 100 human sera containing antibodies against one avian species, predominantly pigeon, reacted also with all other avian species intestines; the remaining forty were more specific and reacted with a few species only. Cross reactions with antigens in song bird intestines indicated the presence of a broad spectrum of antibodies in patients with bird fancier's lung.

Animals↗
PubMed1981

[The indications for middle ear instillation of gentamicin in Menière's disease (author's transl)].

Menière's disease treated by use of Gentamicin sulphate instillation into the middle ear is reported. This drug is injected via a small plastic tube which is inserted into the middle ear. 4 mgm (0.1 ml) of Gentamicine sulphate are instilled every 5 hours until the labyrinth begins to show a reaction. After this treatment 95 per cent of patients no longer suffer from vertigo and tinnitus and the pressure feeling are favourably influenced. The hearing mainly remains unchanged, but sometimes may even improve.

Ear, Middle↗
PubMed1981

[Angiographic demonstration of anastomoses in the hilus of the liver (author's transl)].

141 angiographic examinations of the upper abdomen were made of a randomized group of patients to check the arterial supply of the liver, thus giving the opportunity to test anastomoses in the hilus of the liver and to find out their frequency. These vascular connections are of importance for surgical treatment as well as for angiotherapeutic procedures such as chemotherapy infusion or embolization of the hepatic artery.

Angiography↗
PubMed1980

Maturation of hypothalamic-pituitary-thyroid response in the rat to acute cold.

Groups of rats 3, 4, 5, 7, and 10 wk of age were tested for their ability to respond to acute cold (4 degrees C for 30 min). Thyroid reactions were estimated from intrathyroidal colloid droplet (CD) counts, serum thyrotropin (TSH) and thyroxine (T4) levels. Normally CD counts increased to a maximum in the 5-wk-old rats were lower in the 7-wk-old, and still lower in the 10-wk-old animals. The significant finding was that exposure to cold caused a decrease in CD counts in 3-, 4-, 5-wk-old rats but an increase in mature animals. This CD decrease was apparent within 10 min in the 4- and 5-wk-old rats, Injections of TSH and thyrotropin-releasing hormone (TRH) raised CD counts in all age groups but had little effect on response to cold. TSH serum levels were higher in the 5-wk-old than in the 3- and 4-wk-old animals; cold caused a greater TSH reduction in the 5-wk-old rats than in younger groups. Serum T4 levels were approximately the same in 3-, 4-, and 5-wk-old rats; when they were exposed to cold, the level rose despite the fact that CD counts dropped. These data indicate that in rats hypothalamic-pituitary-thyroid reactions to acute cold attain the adult pattern between 5 and 7 wk after birth.

Adaptation, Physiological↗
PubMed1980

Measurement by radioimmunoassay of soluble elastins from different animal species.

By radioimmunologic techniques, it has been possible to detect two serologically distinct elastin antibody fractions in antiserum prepared against bovine ligamentum nuchae elastin; a species specific fraction which bound only bovine elastin, and a population of antibodies with affinity for elastin from porcine aorta, bovine ligamentum nuchae and aorta, rabbit and hamster lung, and human aorta. Bovine specific antibodies were detected when bovine alpha-elastin was used as specific ligand whereas interspecies reactivity was detected when radiolabeled nonbovine solubilized elastins were used in the assay. Two distinct antibody populations were confirmed using immunoabsorption techniques. Thus, the elastin radioimmunoassay can be modified to detect bovine or other elastins depending upon the choice of radiolabeled antigen. The assay permits determination and quantification of elastin synthesis and degradation in a wide range of species without having to raise specific antibodies to each.

Amino Acids↗