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Biomedical subjects

K Meyer

Publications and source records attributed to K Meyer.

At least 253 records · Page 14Linked to original sources
PubMed1979

[The value of irreversible contraception].

8 years after sterilization was in force in GDR it is stated, that this way of female healthy protection was different performed in the varions countries of GDR. The portion of the country Rostock amount to 56,6%. --85,3% of the women were elder than 30 years. 60% of the applicants have had legal abortions. 66,8% of the propositions were based by medical indication. --The rate of complications and failures amount to 0,3%. --By reason of the results it is recommended to regard the sterilization as the adequate method of contraception, if reproduction is finished.

Adolescent↗
PubMed1977

Root surface roughness in response to periodontal instrumentation studied by combined use of microroughness measurements and scanning electron microscopy.

Root surface roughness, resulting from calculus removal by hand curette, ultrasonic curette and rotating diamond or Roto-Pro points, was examined by combined use of microroughness measurements and scanning electron microscopy (SEM). Mandibular incisors were placed in a jaw model with a rubber "gingiva" in an attempt to simulate a clinical situation. After cleaning with the various instruments, the surface roughness was measured by an industrial profilometer followed by SEM evaluation. A microroughness index (MRI) was developed and showed that the instruments could be separated into three groups, where the hand curette produced least roughness, followed by the Roto-Pro instrument, while the ultrasonic curette and the diamond left the most uneven surfaces. A SEM roughness index (SRI) based on defined criteria, corresponded well with the results from the profilometer measurements, except that using this index the diamond scored higher than the ultrasonic curette. This was probably due to considerable calculus remnants remaining in the ultrasonic specimens. Characteristic features of the root surface morphology of the cleaned teeth are described. It is concluded that the combined use of microroughness measurements and SEM is of considerable value in this type of studies since more information may be obtained than by any of these methods used separately.

Dental Calculus↗
PubMed1977

Calculus removal and loss of tooth substance in response to different periodontal instruments. A scanning electron microscope study.

The efficiency of calculus removal and the amount of lost tooth substance resulting from the use of hand curette, ultrasonic curette and rotating diamond and Roto-Pro points were examined by scanning electron microscopy (SEM). Root surfaces of mandibular incisors placed in a jaw model were cleaned of adhering deposits, photographed by SEM and evaluated at a standard magnification by three examiners. Scores were given for remaining calculus (RCI) and loss of tooth substance (LTSI) according to defined index criteria. The results revealed that calculus removal was most complete following diamond instrumentation, whereas the ultrasonic curette was least efficient in this respect. Hand curette, ultrasonic curette and Roto-Pro removed about the same amount of tooth substance whereas the diamond removed considerably more than the others. The diamond regularly removed all the cementum and left deep instrumental marks in the dentin; it seems advisable to avoid the use of such instruments in periodontal depuration.

Curettage↗
PubMed1977

[Aqueous humor levels of gentamicin after parenteral, subconjunctival and topical administration (aithor's transl)].

The purpose of this study was to determine the concentration of Gentamicin in blood serum and primary aqueous humor at varying periods of time after intravenous, intramuscular, subconjunctival and topical administration of Gentamicin. Therapeutic effective levels in primary aqueous humor were measured only after subconjunctival injections. The only broad spectrum antibiotics are the aminoglykosides Gentamicin, Tobramycin, Sisomicin and Amikacin. For prompt treatment of bacterial endophthalmitis without bacterial culture and antibiotic sensitivity testing therefore subconjunctival injection of Gentamicin is necessary.

Administration, Topical↗
PubMed1975

The structure of a sulfated glycoprotein of chick allantoic fluid: methylation and periodate oxidation.

The structure of an antigenic, sulfated glycoprotein from chick chorioallantoic fluid has been investigated by exogalactosidase digestion, methylation and mass spectral analyses, periodate oxidation, and Smith degradation. The main carbohydrate chains are composed of D-galactosyl residues linked at C-3 and 2-acetamido-2-deoxyglucose residues linked at C-4. Fucose and N-acetylneuraminic acid residues are nonreducing terminal groups, and the N-acetylneuraminic acid groups are linked to the D-galactose residues at C-3. Most of the sulfate groups (91% of the sulfate) are located on C-6 of the 2-acetamido-2-deoxyglucose residues, and the rest on C-6 of the D-galactose residues. A large number of the D-galactose residues (36.9% of the total) are present as nonreducing terminal groups and another 21.7% of the D-galactose residues are in penultimate position to the nonreducing terminal N-acetylneuraminic acid residues. Although mild periodate oxidation indicates the presence of D-galactose in furanoside form (5.5% of total D-galactose), no 5-O-methyl derivative of D-galactose was observed on methylation.

Allantois↗
PubMed1975

The structure of keratan sulphates from various sources.

Quantitative structural comparisons were made between keratan sulphates isolated from various sources, namely pig nucleus pulposus, bovine cornea, and the costal cartilages of children, a young adult with Marfan syndrome and of old human autopsies. In human costal cartilage the amount of keratan sulphate increases markedly with age, although total mucopolysaccharide decreases to some extent, concomitant with a decrease in chondroitin 4-sulphate and an increase in chondroitin 6-sulphate. Comparison of molecular weights estimated by gel chromatography with those calculated from the molar ratio of galactose to mannose indicates that keratan sulphates of human costal cartilages of children and of a young adult with Marfan syndrome, and of pig nucleus pulposus, contain one mannose residue per chain, whereas keratan sulphates of old human costal cartilage and of bovine cornea contain one to two, and two, per chain respectively. After mild acid-catalysed desulphation of pig nucleus pulposus keratan sulphate, approx. 12% of the mucopolysaccharide aggregates irreversibly once the water is removed from the polysaccharide. The following conclusions have been drawn from a methylation analysis of keratan sulphates of various sources, aided by g.l.c.-mass spectrometry. (1) Fucose and N-acetylneuraminic acid are non-reducing terminal residues and the sialic acid is linked to the 3-position of galactose residues. (2) Pig nucleus pulposus keratan sulphate has approximately 4 non-reducing terminal groups per molecule and appears to be slightly less branched than the costal-cartilage keratan sulphate of children. The branching in human costal-cartilage keratan sulphates decreases with age. Bovine corneal keratan sulphate appears to be unbranched. (3) Mannose residues are linked by 3 different substituents in human costal-cartilage and bovine corneal keratan sulphates, and by two different substituents in pig nucleus pulposus keratan sulphate. (4) The sulphate ester groups are all on the 6-position of N-acetyl-glucosamine and galactose residues. The degree of sulphation increases with age in costal keratan sulphates with the increase mainly of the galactose 6-sulphate residues.

Acetylation↗