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Biomedical subjects

M Becker

Publications and source records attributed to M Becker.

At least 397 records · Page 22Linked to original sources
PubMed1978

Rheumatoid arthritis and its variants: analysis of scintiphotographic, radiographic, and clinical examinations.

99mTc pyrophosphate radionuclide scans of the axial and appendicular skeletons in 23 patients with rheumatoid arthritis and 15 patients with systemic arthritic conditions were compared to clinical and radiographic examinations. The nuclear scan was the most sensitive indicator of active disease and correlated extremely well with the other methods. A pattern of abnormal radionuclide activity in rheumatoid arthritis consisting of a symmetric peripheral joint process can be distinguished from that of the rheumatoid variants which tend to have more central skeletal involvement and asymmetric peripheral articular involvement. The nuclear scan is less specific than the radiograph in its ability to distinguish among the clinical entities. However, documentation of scintigraphic activity often antedated radiographic or clinical abnormalities.

Adult↗
PubMed1978

[Technique of the introduction of duodenal sounds in children (author's transl)].

Duodenal Sounds, provided they are sufficiently rigid, can be introduced actively with simultaneous x-ray control. Good sedation promotes rapid passage; further important aids are: appropriate positioning of the patient, instillation of air, and palpation. In recent years, intravenous administration of diazepam and metoclopramid has proved successful as premedication. The described procedure reduces the strain on the children and the amount of time required by the medical staff.

Child↗
PubMed1978

[Secondary structure of condensed DNA. wide-angle, small-angle x-ray scattering and circular dichroism].

Ethanol precipitated DNA shows a CD spectrum of the +psi-type which is similar to that of DNA in the A-form. DNA condensed with cetyl-trimethylammonium-bromide shows, depending on the condensation velocity, a CD spectrum of the -psi-type, or a CD spectrum only slightly modified from that of DNA in solution. The first spectrum is similar to that of DNA in the C-form, and the second one, to that of DNA in the B-form. Using large-angle X-ray scattering of the three DNA condensates and comparing them with the scattering curves calculated from the atom coordinates for the A-, B-, and C-form of DNA it is shown that the secondary structure of the DNA belongs in all three cases to the B-family. It follows from this result that the secondary structure of DNA alone does not determine the type of CD spectrum. The CD spectrum of condensed DNA is essentially determined by the supramolecular structures of the partially crystalline DNA condensates. These supramolecular structures can be demonstrated by the small-angle X-ray diagrams. The condensation of DNA by ethanol and cetyl-trimethylammonium-bromide proceeds in the form of a partial crystallization of the DNA.

Animals↗
PubMed1977

Selective vitamin B12 malabsorption (Imerslund-Gräsbeck syndrome). Studies on gastroenterological and nephrological problems.

In a girl 10 years of age with selective vitamin B12 malabsorption associated with proteinuria and residual symptoms of funicular myelosis an extensive study of the intestinal and nephrologic functions was done. Repeated Schilling tests pointed to a malabsorption pattern of vitamin B12. Gastric acid and intrinsic factor secretion as well as gastric morphology were normal. There were no antibodies against intrinsic factor and parietal cells in serum. Ileal mucosa showed on light- and electron-microscopy no pathologic changes. Pancreatic exocrine function as well as pH and calcium concentrations in the lumen of the gut were within the normal range. A general malabsorption syndrome could be excluded. A high selective glomerular proteinuria was found through different methods. Inulin clearance was slightly reduced, PAH clearance, however, markedly so. There was no further evidence for renal tubular dysfunction. Renal biopsy showed a minimal proliferative intercapillary glomerulonephritis (minimal changes). In electron-microscopic studies a fusion of a part of the foot processes of the podocytes was found. No familialhistory of the syndrome could be demonstrated in our patient.

Anemia, Macrocytic↗
PubMed1977

Decrease of non-suppressible insulin-like activity after pancreatectomy and normalization by insulin therapy.

Non-suppressible insulin-like activity (NSILA-S) was determined in 5 dogs before and after pancreatectomy and again during insulin therapy. All NSILA-S determinations were carried out on serum samples which were passed over Sephadex G-50 columns equilibrated with 1 M acetic acid. The levels of NSILA-S decreased drastically shortly after pancreatectomy and rose slowly after institution of insulin therapy, to normal levels. During the period of severe diabetes after pancreatectomy the concentration of growth hormone was elevated. These findings indicate that 1) the pancreas cannot be the site of synthesis and release of NSILA-S, 2) NSILA-S levels do not always parallel growth hormone levels and 3) the synthesis and secretion of NSILA-S among other factors is under the control of insulin.

Animals↗
PubMed1977

The influence of hypophysectomy on NSILA concentrations in the dog: evidence for partially pituitary-independent regulation.

Non-suppressible insulin-like activity (NSILA) was determined in 5 dogs before and after hypophysectomy. All NSILA determinations were carried out on serum samples after acidic Sephadex G-50 chromatography by two different assay systems, i.e. a bioassay and a protein binding assay. The levels of NSILA decreased significantly after hypophysectomy and returned to near normal levels after 2 weeks. T3-, T4- and cortisol levels were drastically reduced during the entire period of the experiment. Several GH determinations after hypophysectomy revealed very low levels. Insulin-induced hypoglycaemia failed to provoke a rise of GH levels as late as 4 months after hypophysectomy. These findings indicate that: 1) The pituitary gland cannot be the site of synthesis of NSILA. 2) NSILA concentrations in the dog are maintained at a near normal level in the presence of very low growth hormone and thyroid hormone concentrations, so that these latter hormones do not appear to be the only regulatory factors concerned in NSILA synthesis.

Animals↗
PubMed1977

[Diffuse x-ray wide-angle scattering of polyglutamic acid in solution].

The diffuse wide angle x-ray scattering (WAXS) of polyglutamic acid (PGA) in solution was studied using an x-ray diffractometer with small aperture of the primary beam. The scattering curve was recorded at an angular interval from (article: see text). The experimental scattering intensity of PGA with alpha-helical CD spectrum showed a maximum at 14.4 nm-1. Unordered PGA in solution yielded no maximum at this scattering angle. The studies have proved that the scattering theory can be applied to globular proteins in solution as well as to chain molecules in solution in this angular interval. The differences between the calculated scattering curves and the experimental curves indicate minor movements of the side chains of PGA in solutions and slight structuring of the solvent at the surface of the polypeptide chain.

Glutamates↗
PubMed1977

Heterologous reactivity of in vitro cultured mouse cells with natural human serum antibodies.

Studies employing the cytotoxic and immunofluorescence tests revealed presence of natural human serum antibodies in the serum of various human donors, which reacted with normal and pathologic mouse cells cultivated in vitro. This reactivity was due to presence on the cell surface of heterologous HMAg antigen incorporated into the cell membrane from calf serum. Immunofluorescence studies demonstrated localization of this antigen on the cell surface. Absorption of human sera with calf serum or with lyophilized cow's milk abolished or markedly weakened the ability of these sera to react with cultured mouse cells.

Animals↗
PubMed1977

[Alpha1-fetoprotein: physiology, pathology and diagnosis especially in childhood (author's transl)].

Alpha1-fetoprotein (AFP) is an alpha1-glycoprotein which can be found in high concentration during fetal development in many mammals, birds, sharks and, also, man. The alpha-fetoproteins of various species have similar physico-chemical properties and often common antigenic determinants. Differences of microheterogeneity depend on a different content of sialin-acid. During human fetal development the serum AFP concentration falls with increasing gestational age. 4-5 weeks after birth AFP can be detected usually in low serum concentrations. Using more sensitive immunulogic techniques e.g. radioimmunoassay there was shown that AFP is present in sera of normal adults in concentrations of 10-20 ng/ml. AFP serum concentrations rise physiologically during pregnancy up to 500-550 ng/ml. During fetal development liver, yolk sac and gastrointestinal tract are the major sites of synthesis. In primary liver cell carcinoma, hepatoblastoma and in teratoblastoma containing yolk sac tissue AFP synthesis rises in tumor cells; the AFP serum concentration increases above 2 microgram/ml. In patients with benign liver diseases e.g. virus hepatitis, a transient rise of AFP serum concentrations was seen. Moreover, increased levels of AFP were found in hereditary diseases e.g. congenital tyrosinemia, ataxia-telangiectasia and in the amniotic fluid in congenital nephrosis of Finnish type. AFP assay in serum is clinically important for the control of course and treatment of primary liver cell carcinoma and teratoblastoma. AFP assay in amniotic fluid is a method for the prenatal detection of neural tube defects and the fetal distress syndrome, especially.

Adolescent↗
PubMed1976

[Serum-gastrin levels and gastric-acid secretion in infants (author's transl)].

Gastric acid secretion was measured in 20 infants aged 6-438 days. The values for the basal acid output and that after stimulation with 6 mug/kg pentagastrin subcutaneously were found to be related to age, body weight and body surface area. But these correlations were not comparable to those in adults. Standard values for different age groups in childhood must therefore be established. Furthermore, the results indicate parietal-cell immaturity during the first six months of life. Measurement of fasting serum-gastrin concentration by radioimmunoassay in 74 infants, aged 1-438 days, and 154 adults as controls revealed a high serum-gastrin level in infants, with an exponential decrease during the first year of life. Despite comparable pH values in gastric juice at one year of life, the gastrin concentrations were higher than those in adults (at a statistically significant level). On the other hand, normal serum-gastrin concentrations were found in ten pregnant women just before delivery. The results suggest a negative feed-back mechanism between gastric-acid secretion and fasting serum-gastrin levels, but such mechanism probably being limited by extragastric gastrin secretion.

Age Factors↗
PubMed1976

[HL-A histocompatibility antigens in children with coeliac disease (author's transl)].

HL-A antigens were determined in 41 unrelated coeliac children and in clinically healthy parents and siblings of 40 of these patients using a lymphocyte microcytotoxicity test. 58.5% of the coeliac patients had phenotype HL-A 8 compared with an HL-A 8 frequency of 16.6% in a control group of 320 unrelated individuals (P less than 0.0005). Excluding five patients not of pure German origin HL-A 8 frequency increases to 63.9%. The increase of HL-A 1 frequency in coeliac patients is attributed to linkage disequilibrium between HL-A 8 and HL-A 1. The haplotype HL-A 1.8 frequency was significantly increased in coeliac children (P less than 0.0001) with frequency elevation also in parents (P approximately 0.025) but not in siblings. Furthermore, an increase in frequency of HL-A 12 and a decreased frequency of HL-A 7 and HL-A 9 was found in coeliac patients. Five clinically healthy siblings had the same HL-A haplotypes as their affected sisters and brothers.

Adolescent↗