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Biomedical subjects

R Thieme

Publications and source records attributed to R Thieme.

At least 19 recordsLinked to original sources
PubMed1986

3-Azi-1-methoxybutyl D-maltooligosaccharides specifically bind to the maltose/maltooligosaccharide-binding protein of Escherichia coli and can be used as photoaffinity labels.

Maltooligosaccharides with two to six (alpha 1-4)-linked glucose residues, carrying at their reducing end a 3-azi-1-methoxybutyl group in either alpha or in beta glycosidic linkage, were synthesized. These maltooligosaccharide analogues inhibit maltose uptake via the maltose-binding-protein-dependent transport system in Escherichia coli. The concentration of half-maximal inhibition of maltose transport, at 15 nM concentration, decreases with increasing chain length of the analogue, levelling off at 40 microM after a chain length of four glucose residues in the alpha series and at 350 microM after a chain length of three glucose residues in the beta series. The inhibition of maltose transport occurs at the level of the periplasmic maltose-binding protein. 3-Azi-1-methoxybutyl alpha-D-[3H]maltotrioside was bound by the maltose-binding protein with a Kd of 0.18 mM. Irradiation at 350 nm of purified maltose-binding protein in the presence of 4 microM of this substrate labeled the protein covalently; labeling was prevented by 1 mM maltose. Using a crude preparation of periplasmic proteins two proteins were labeled, the maltose-binding protein and alpha-amylase. Thus, 3-azi-1-methoxybutyl alpha-D-maltooligosaccharides are potent photoaffinity labels for proteins with maltooligosaccharides-binding sites.

ATP-Binding Cassette Transporters↗
PubMed1986

[10-year comparison of deposits of heavy metals in the human placenta].

The environmental influence on the heavy metal's (trace elements) content of the human placenta was determined in tissues from three different regions of the FRG by different analytical techniques. Besides the mean values and the standard deviation the frequency distribution curves of the elements cadmium, lead, zinc, copper, cobalt, manganese and nickel are given. Comparing the results with our findings from ten years ago it seems that cadmium concentrations in the placenta have reached an approximately equal level both in rural and in industrial districts. This is equally true for lead.

Body Burden↗
PubMed1986

Optimized calcium/phosphorus solubility in a parenteral nutrition solution containing dicarboxylic amino acids and cysteine.

The solubility of calcium and phosphorus was studied in neonatal parenteral nutrition solutions containing dicarboxylic amino acids and cysteine. Experimental amino acid solutions containing aspartic acid, glutamic acid, and cysteine in concentrations from 0.5% to 2.0% were studied with dextrose concentrations of 5-20% plus standard electrolyte, vitamin, and trace element additives. Solutions were held at room temperature for 24 hr prior to incubation in a 37 degrees C water bath for 30 min. The pH of each solution was determined. Precipitation was detected by light scattering on a Cobas Bio centrifugal analyzer. An absorbance greater than 0.015 at 600 nm was considered evidence of precipitation. The pH of test solutions ranged between 5.7 and 6.4. Increasing amino acid concentration produced an improvement in calcium/phosphate solubility. Change in dextrose concentration had a lesser effect. Solutions of 10% dextrose with 2% amino acids contained 40 mEq/liter calcium and 17 mmol/liter phosphorus without precipitation. Administered at 150 ml/kg/day, such a solution would provide 120 mg/kg body weight/day calcium and 80 mg/kg/day phosphorus, approximately the daily in utero accretion rates during the last trimester. This is not readily achieved in comparable solutions of previous amino acid formulations.

Amino Acids, Dicarboxylic↗
PubMed1981

[Radiotherapy of the juvenile xanthogranuloma of the iris (author's transl)].

A report is given on an eight months old child with a juvenile xanthogranuloma of the iris and a secondary glaucoma. After radiotherapy with 6 X 0,5 Gy under conventional deep therapy conditions, a soon regression of the increased intraocular pressure was observed. In case of a juvenile xanthogranuloma of the iris, this secondary glaucoma represents in any case an acute danger to the eye, so it must be treated immediately. Radiotherapy has to be considered as the method of choice; it is also discussed with regard to the risk and the avoidance of a radiation cataract which, however, has to be tolerated in certain cases in order to prevent greater troubles.

Cataract↗
PubMed1980

[Problems in juvenile xanthogranuloma of the anterior uvea (author's transl)].

With reference to a case of juvenile xanthogranuloma localized in the anterior uvea the authors describe the clinical signs, differential diagnosis, morphology and treatment of this disease. If the juvenile xanthogranuloma is located in the anterior uvea, the eye may be severely affected. Spontaneous hyphema in infants is characteristic. At present radiation is the most successful treatment for preserving the bulbus and visual function. The earlier the disease is discovered the better the chances of successful treatment.

Diagnosis, Differential↗
PubMed1980

[Pneumothorax in the newborn].

Pneumothorax in the newborn is described with reference to aetiology and clinical aspects, pathophysiology and radiological symptoms.

Humans↗
PubMed1979

[Visual field response to hypotension following oculopression (author's transl)].

The authors studied the visual fields in 100 healthy persons of different ages before and 10 min after oculopression. They found a depression of the I/2 isopter mostly in the nasal lower quarter of the visual field in persons over 60 years old, due to a disturbed or diminished vascular compensation of bulbus compression. They consider that oculopression might have clinical importance as an indirect provocation test of the cellular blood circulatory system.

Adolescent↗
PubMed1979

[Application of computer tomography (CT) as an additional means of follow-up gynecologic neoplasms-a case documentation (author's transl)].

The application of CT represents an important progress not only in diagnostic and therapeutic planning, but also in the evaluation of the effectiveness of follow-up procedures in gynecologic cancer therapy. The evaluation of the results of some follow-up procedures in a case of leiomyosarcoma uteri shows significance and importance of CT as a new radiologic method. Inspite of preliminary negative results of extensive radiologic, myelographic, laboratory investigations and of technetium- and gallium-scintigraphy, CT proved a solitary metastasis located at S-1 in the os sacrum. The diagnostic aspects of follow-up examinations in patients undergoing cytoreductive surgery or radiotherapy are discussed. CT should not be placed at first rank position, but be considered as an helpful additional means for special cases.

Bone Neoplasms↗
PubMed1979

[The effect of preventive cesarean section in breech presentation on perinatal mortality].

This study is based upon 1229 infants delivered from breech presentations who were investigated for the influence of the prophylactic Caesarean section carried out with primiparae after their 36th week of pregnancy in 1972, on perinatal mortality. The periods under report, i. e., 1966 to 1971 and 1972 to 1975, were compared with one another. The incidence of Caesarean sections carried out in breech presentations increased from 11.6% to 52.2%. With a premature birth rate of 22.1% and 20.9%, respectively, the uncleaned perinatal mortality decreased from 109.2% to 96.5%, whereas the cleaned one dropped from 73.3% to 64.2%. As to mature infants delivered vaginally or by Caesarean section, there was no significant difference in death rates. The worse prognosis for breech presentation infants given birth by pluriparae could be confirmed. The high portion of underweight infants amounting to 78.0% and 82.9%, respectively, in the total number of perinatal deaths illustrates the main problem of the breech presentation births.

Birth Weight↗
PubMed1978

The effect of the mode of administration of nitrogen mustard and cytosine arabinoside on the production of chromosomal aberrations in mouse bone marrow and ascites tumour cells.

The cytogenetic effects of intraperitoneally (i.p.) and subcutaneously (s.c.) administered nitrogen mustard (HN2) and cytosine arabinoside (ara-C) on bone-marrow and ascites tumour cells of mice were studied. Ehrlich ascites tumour-bearing mice were treated with the mutagens, and cytological preparations were made from ascites tumour and bone-marrow cells of the same animal. The following parameters were investigated: frequencies of mitotic and chromosomal aberrations, time of aberration maxima and aberration spectra. HN2 (0.68 mg/kg b.w.), when given i.p., induced in ascites tumour cells a strong inhibition of mitotic frequency and very high aberration rates, whereas in bone marrow no aberrant chromosomes were observed. On the other hand, after s.c. administration, the same dose induced more aberrant metaphases in bone marrow than in tumour cells. Ara-C (315 mg/kg b.w.) resulted, after s.c. administration, in higher aberration frequencies both in ascites and bone-marrow cells compared with i.p. treatment. All ascites tumour cells showed higher aberration requencies than bone-marrow cells. In bone marrow the aberration maximum occurred as soon as 6 h after treatment. Furthermore, clear differences with respect ot the types of aberration found in the two systems were evident. The differences caused by the different modes of administration in two different types of cell are discussed in terms of metabolic inactivation and differences of the two tissues with respect to karyotype, cell cycle time and repair capacity.

Animals↗