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Biomedical subjects

G Janssen

Publications and source records attributed to G Janssen.

At least 73 records · Page 4Linked to original sources
PubMed1982

Structure of the side chain of the C29 dicarboxylic bile acid occurring in infants with coprostanic acidemia.

The structure of the side chain of the 3 alpha, 7 alpha, 12 alpha-trihydroxy-5 beta-C29 dicarboxylic bile acid occurring in body fluids of infants with coprostanic acidemia was investigated by means of mass spectrometry and nuclear magnetic resonance spectroscopy. The findings identified this bile acid as 3 alpha, 7 alpha, 12 alpha-trihydroxy-27a, 27b-dihomo-5 beta-cholestane-26,27b-dioic acid (3 alpha, 7 alpha, 12 alpha-trihydroxy-27-carboxymethyl-5 beta-cholestan-26-oic acid).

Cholestanols↗
PubMed1981

A further study of the bile acids in infants with coprostanic acidemia.

The structure of the bile acids in serum of infants with coprostanic acidemia was further investigated. The identity of 3 alpha-hydroxy-5 beta-cholestan-26-oic acid and 3 beta-hydroxy-5-cholesten-26-oic acid was confirmed. The biosynthesis of the 3 alpha, 7 alpha, 12 alpha-trihydroxy-5 beta-C29 dicarboxylic bile acid does not start from beta-sitosterol.

Acidosis↗
PubMed1980

Disturbances in bile acid metabolism of infants with the Zellweger (cerebro-hepato-renal) syndrome.

The bile acid pattern in bile and serum from two infants with the cerebro-hepato-renal syndrome of Zellweger was severely disturbed. An increased concentration particularly of trihydroxycoprostanic acid and also of dihydroxycoprostanic acid could be demonstrated. A generalized mitochondrial defect could explain these increased concentrations. This hypothesis is supported by the abnormal structure of the mitochondria in the liver biopsy of one of our patients. It is possible that the abnormal bile acids contribute to the liver damage of infants with Zellweger syndrome.

Bile Acids and Salts↗
PubMed1978

Determination of double bond positions in fatty acids with conjugated double bonds.

The positions of the double bonds in fatty acids with conjugated double bonds may be determined by mass spectrometry of the methyl esters of their trimethylsilyl ether derivatives obtained by hydroxylation of the double bonds followed by silylation of the resulting polyols. The method has been applied to trans-9,trans-11- and trans-10, trans-12-octadecadienoic acid.

Chemical Phenomena↗
PubMed1978

[A method for measuring the distal torsion of the femoral bone (author's transl)].

A new method of measuring the distal torsion of the femoral bone is introduced. The term "torsion" is defined, and the etiology of femoral torsion is scrutinized. The sources of error are discussed after a description of the process of measurement and of the calculation of the angle of torsion. The aim and value of this method are, firstly, to supply evidence for the existence of a prearthrosis factor of the patellofemoral joint, and, secondly, to be of practical importance for the consequences of surgery. These consequences will be discussed elsewhere.

Adult↗
PubMed1978

[Etiology of dislocation of the patella (author's transl)].

Using a new method for measuring the distal femoral torsion (Janssen a. Prüssner 1977) it is possible to determine the encreased medial torsion of the distal femur in most of the patients with dislocation of the patella. A group of patients with dislocated knee-cap was studied for this purpose. The characteristic clinical and x-ray features are listed and weighted according to their value. They throw a new light on the pathogenesis and pathomechanics of patellar luxation, and point to the need to reclassify the different types of luxations according to etiological aspects.

Adolescent↗
PubMed1977

Preparation of trimethylsilyl derivatives of thiamphenicol.

The silylation of thiamphenicol has been investigated. Treatment of thiamphenicol with hexamethyldisilazane or N-trimethylsilylimidazole, either alone or in the presence of trimethylchlorosilane, in acetonitrile or pyridine yields the bis(trimethylsily) (TMS) ether derivative. These procedures, however, cause to some extent the formation of 1-(p-methylsulphonylphenyl)-2-monochloroacetamido-1,3-propanediol. Silylation with N,O-bis(trimethylsilyl)acetamide gives, depending on the solvent used, the mono-, bis- and tris-TMS derivatives.

Anti-Bacterial Agents↗
PubMed1977

Preparation and properties of derivatives of virginiamycin S.

Reduction of virginiamycin S with sodium borohydride produces allo- and normal-dihydro-virginiamycin S. Reduction of the tosylhydrazone of virginiamycin S with sodium cyanoborohydride affords deoxyvirginiamycin S. These compounds are less active than virginiamycin S. Like virginiamycin S they enhance the activity of virginiamycin M1.

Bacteria↗
PubMed1976

[The position of the supracondylar correction osteotomie during the treatment of the senile gonarthrosis (author's transl)].

The position of the supracondylar correction osteotomie during the treatment of the senile gonarthrosis is examined by controls of 17 patients with 21 performed osteotomies. The indication, the technique as well as the clinical and radiological results of the operation are critically dealt with. In case of a correct indication and when considering the contra-indication-like and existing strong osteoporosis, a distinct deficit of expansion and a most serious arthrosis-good results can be expected.

Aged↗