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Biomedical subjects

S Kirkeby

Publications and source records attributed to S Kirkeby.

At least 55 records · Page 3Linked to original sources
PubMed1989

The influence of temperature on the distribution and intensity of the reaction product in rat muscle fibers obtained with the histochemical method for myosin ATPase.

The influence of temperature in the incubation medium on the localization and intensity of myosin ATPase was investigated in striated muscles from the rat using a conventional histochemical technique. It was found that the enzyme reaction was temperature-dependent since the activity in some fibers was raised and in others was depressed by alteration of the incubation temperature. There was no obvious correlation between the temperature sensitivity of ATPase in the muscle fibers and their activity for succinic dehydrogenase. It is proposed that the histochemical method for myosin ATPase can be used for demonstration of isoenzymes in striated muscle fibers.

Animals↗
PubMed1989

Skull development in the muscular dystrophic mouse.

Roentgencephalometric tracings of skulls of 7-week-old normal and muscular dystrophic mice were compared. A marked size reduction of the dystrophic skulls relative to the normal ones was observed. However, the visceral parts of the dystrophic skull were more reduced in size than the neural parts. Marked differences in shape were also noticed. Differences in angular values were primarily found between skull parts, whereas angles between adjacent bones were remarkably similar in the two groups. Only a few exceptions of this condition were observed, as angles between adjacent bones in the posterior part of the cranial vault of the dystrophic animals differed from those of the normal animals. The observed differences between normal and dystrophic mice skulls may chiefly be explained as the results of differences in the action of diseased and normal muscles on bone.

Animals↗
PubMed1989

Incidence of centrally positioned nuclei in mouse masticatory muscle fibers.

Cross-sections of normal digastric, temporalis and masseter muscles from 7- and 30-week-old mice were studied for centrally positioned nuclei. Such nuclei were inhomogeneously distributed throughout each muscle and varied markedly between specimens. The incidence of centrally positioned nuclei in the digastric muscle (mean +/- SD: 0.029 +/- 0.015, n = 25) was significantly higher (p less than 0.001) than that in the temporalis (mean +/- SD: 0.011 +/- 0.010, n = 25) and masseter muscles (mean +/- SD: 0.005 +/- 0.007, n = 9), but did not differ between the two latter muscles (p = 0.41). Furthermore, the frequency in a given muscle was apparently age-independent. A connection between fiber type and centrally positioned nuclei is suggested.

Animals↗
PubMed1989

Chromatographic separation of alkaline phosphatase from dental enamel.

Alkaline phosphatase (AP) was prepared from partly mineralized bovine enamel by extraction in phosphate buffer, centrifugation and various chromatographic techniques. Chromatofocusing showed that the enamel enzyme possessed five isoelectric points at the acid pH level ranging from pH 5.7 to pH 4.4. Three enzyme peaks were eluted using low pressure chromatography with a Bio-gel column. With a HPLC gel filtration column the separation of the enamel extract resulted in only one peak with AP activity. The fractions of this peak were used to produce an antibody against bovine AP.

Alkaline Phosphatase↗
PubMed1988

A comparison between activities for non-specific esterases and esterproteases.

Electrophoretic separation of non-specific esterases and esterproteases from kidney, lung, and liver have been carried out in polyacrylamide gels. By use of zone electrophoresis, isoelectric focusing, and 2-dimensional electrophoresis it was found that most of the esterprotease bands had the same localization in the gels as non-specific esterase bands. A number of esterase bands showed no activity towards the esterprotease substrates and a single kidney band possessed esterprotease activity only. Isozymes of the ES-6 and ES-9 zones showed sex dependent esterprotease reactions. In sections esterase activity was located to all parts of the proximal tubule. In male kidneys, esterprotease activity was present in the 2nd segment of the convoluted tubule which is not connected to glomeruli and in the descending part of the proximal tubule. In female kidney only the descending part of the proximal tubule showed esterprotease activity.

Alanine↗
PubMed1988

Masticatory muscles in the muscular dystrophic mouse. Aspects of the age-related progression of the disease.

Cross-sections of normal and dystrophic digastric and masseter muscles from 7- and 35- to 40-week-old mice were studied in the light microscope. Comparisons of mean cell size, cell size variance and number of centrally positioned nuclei in a given number of fibers were carried out. The masseter muscle seems at both ages to be far more affected by the disease than the digastric muscle. However, the progression of the disease from 7 to 40 weeks is more pronounced in the digastric muscle than in the masseter muscle.

Aging↗
PubMed1988

Macrophages and mast cells in dystrophic masseter muscle: a light and electron microscopic study.

Macrophages and mast cells in masseter muscle from normal and dystrophic mice were studied by light and electron microscopy. Acid phosphatase activity and FITC-dextran were used to identify and describe macrophages. Toluidine blue was used as a marker for mast cells. In dystrophic muscle, the number of macrophages was greatly increased and they contained large amounts of phagocytozed material. In normal muscle, mast cells were rarely identified whereas dystrophic muscle contained many mast cells which were often in close contact with macrophages.

Acid Phosphatase↗
PubMed1988

Esterase profile of human masseter muscle.

The esterase profile of fresh human masseter muscle was investigated by use of histochemistry and electrophoresis. The histochemical methods included reactions for alpha-naphthyl esterase, myofibrillar ATPase, reverse myofibrillar ATPase and succinic dehydrogenase. In frozen sections of the muscle the coloured reaction product for esterases was present both as a diffuse sarcoplasmic coloration and as distinct granules. The intensity of diffuse reaction was used to classify the muscle fibres as strongly, moderately and weakly reacting. The fibres with strong esterase activity belonged to Type I and iiC. iM and Type II A fibres showed a moderate esterase reaction and Type II B fibres had a low activity. The electrophoretic gels stained for esterase activity showed that the human masseter muscle possesses a slow migrating double band with high enzyme activity and a cascade of faster migrating isoenzymes. In isoelectric focused gels the major esterases showed isoelectric points around pH 5.

Esterases↗
PubMed1986

Studies on the actions of glutaraldehyde, formaldehyde, and mixtures of glutaraldehyde and formaldehyde on tissue proteins.

The effects of aldehyde fixation on tissue proteins was studied using SDS-polyacrylamide gel electrophoresis. Fixation with low concentrations of formaldehyde or glutaraldehyde had only a slight effect on the protein banding pattern. On the other hand, most of the original protein bands were absent after a short treatment with mixtures of formaldehyde and glutaraldehyde. Spectral absorption measurements showed a stronger absorption at both gamma = 280 nm and gamma = 235 nm with the glutaraldehyde-formaldehyde mixture than with glutaraldehyde alone.

Aldehydes↗
PubMed1986

Histomorphometry of masticatory muscles in the muscular dystrophic mouse.

Cross sections of normal and dystrophic digastric, masseter and temporalis muscles from 7-week-old mice were studied by histomorphological and histomorphometrical methods in the light microscope. The histomorphological part of the study revealed marked differences in morphology between normal and dystrophic muscles. Mutual differences between the dystrophic muscles were also observed. Comparisons of the parameters chosen for the histomorphometrical part of the study, i.e., cell size and number of centrally positioned nuclei in a given number of fibers, revealed that the digastric muscle seems to be the least affected and the masseter muscle the most affected by the disease.

Animals↗
PubMed1986

Effects of different extraction media on the electrophoretic pattern of proteins from partly mineralized bovine enamel.

Five different extraction solutions were used to isolate matrix proteins from immature bovine enamel, to evaluate the effect of this procedure on the pattern obtained after electrophoresis. By sodium dodecyl sulfate-polyacrylamide gel electrophoresis, the dominating protein fraction in the ethylenediaminetetraacetic acid extract had a molecular weight of 67,000 daltons. The acetic acid and phosphate buffer extracts contained mostly low molecular weight proteins. Isoelectric focusing showed that most of the enamel proteins had isoelectric points below pH 7.0.

Acetates↗
PubMed1986

Influence of cations on enamel phosphatase activity.

ATP and 5-Br-4-Cl-indoxyl phosphate were used as substrates for spectrophotometric measurement of phosphatase activity in partly mineralized bovine enamel. MgCl2, CaCl2, NaCl, and KCl were used as moderators of the enzyme activities. It is concluded that at least two phosphatases, active at alkaline pH, are present in the immature enamel matrix.

Alkaline Phosphatase↗
PubMed1986

Biochemical characterization of alkaline phosphatase from partly mineralized bovine enamel.

Alkaline phosphatase (AP) from partly mineralized bovine enamel was studied. The enzyme resembles alkaline phosphatases in other calcifying tissues. The Km was 0.46 mM; the phosphatase was strongly inhibited by 1 mM Levamisol or EDTA and it showed the same sensitivity towards heating as bone alkaline phosphatase. The inactivation caused by phosphate ions was approximately about 30%. In a zymogram, five isozymes of enamel alkaline phosphatase can be recognized. In a SDS-polyacrylamide gel a single band showing enzyme activity was visualized. This enzyme has an apparent molecular weight of 140,000.

Alkaline Phosphatase↗
PubMed1985

Biochemical and histochemical studies on alkaline phosphatase in normal and dystrophic muscle.

In muscles from dystrophic mice the activity of alkaline phosphatase is 50-75% higher than in their control littermates. In the dystrophic animals all muscle fibres show strong enzyme activity. It is suggested that during dystrophy amounts of an already existing muscle alkaline phosphatase are produced rather than that a synthesis of a new isoenzyme should be initiated.

Alkaline Phosphatase↗
PubMed1985

Immunoblotting demonstration of antibodies to the organic matrix of developing bovine enamel.

Antiserum was raised against an acetic acid extract of partly mineralized bovine enamel. By use of immunoblotting it was shown that rabbit antibodies react with both high and low molecular weight proteins. Most but not all of the enamel proteins isolated by different extraction solutions were antigenic identical. The blotting time was found to be important when immunoblotting of enamel proteins is carried out.

Animals↗