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Biomedical subjects

B Hentzer

Publications and source records attributed to B Hentzer.

28 records · Page 2Linked to original sources

Apatite crystals in pseudoxanthoma elasticum: a combined study using electron microscopy and selected area diffraction analysis.

Calcium deposits in elastic fibers of involved skin of patients suffering from pseudoxanthoma elasticum have previously been reported. In the present work, the crystalline structure and composition were studied. Involved skin was obtained from 5 patients. Bright-field and dark-field electron microscopy and selected area electron diffraction of the calcium deposits were applied. The study demonstrates calcium apatite crystals.

Apatites↗

The ultrastructure of Leishmania tropica in skin lesions.

The ultrastructure of the amastigote stage of Leishmania tropica has been studied. The present work reports on new observations on the fine structure of the basal body, prokinosome and flagellum. The basal body is composed of a centriole-like structure and a transitional zone continuous with the proximal part of the flagellum. The centriole-like part consists of nine peripheral triplet tubules and an indistinct dense central core. The transitional zone consists of nine peripheral doublet tubules and two central cylinders. The centriole-like prokinosome is present parallel and close to the basal body. The flagellum arises from the transitional zone of the body and has the classical axoneme (9+2) structure. However, at the tip of the flagellum the central tubules are replaced by one of the peripheral doublet tubules. The ultrastructural findings, as compared with previous studies of Leishmania, are discussed.

Adult↗

Fibrodysplasia ossificants progressiva.

Two cases of fibrodysplasia ossificans progressiva are reported. Both patients were females and had suffered from the disease since birth. The characteristic anomalies of great toes and thumbs associated with multiple ectopic ossifications of the connective tissue are described. Fasciae, tendons, ligaments, and joint capsules of the proximal parts of the extremities and the dorsal aspect of the trunk were involved. The muscle atrophy was probably a secondary phenomenon.

Adult↗

Ultrastructure of prolapsed disc.

Prolapsed tissue and removed interspace contents were obtained during hemilaminectomy for disc prolapse. The ultrastructure of the tissue was studied. Division of the material into annulus fibrosus and nucleus pulposus proved to be inaccurate. Chondrocytes were always the predominant cell type and could be classified into normal, cloning and necrotized types. Matrix vesicles were found in relation to the haloes of chondrocytes and seemed to be products of disintegrated chondrocytes. Findings of crystals in the vesicles were rare. The intercellular substance showed degraded collagen fibrils, which could be seen in spindle shaped cells as well. A dense amorphous material interpersed with collagen fibrils seemed to be a glycoprotein. A few elastic fibres were found, but without any evidence of severe degeneration. These findings represent changes occuring in cells and in the intercellular substance.

Adult↗

Ultrastructure of dermal connective tissue in fibrodysplasia ossificians progressiva.

The ultrastructure of dermal connective tissue in two patients suffering from fibrodysplasia ossificans progressiva (syn myositis o.p.) was studied. The disorder starts with soft tissue swelling which subsequently ossify. The connective tissue of various organs may be affected. No defects in calcium metabolism have been discovered. It was intended to study the primary event which initiates the ossification. The present ultrastructural study demonstrates an accumulation of proteoglycan microfibrils as well as glycoprotein material in dermal connective tissue. Both substances are prerequisites of calcification resulting from the binding of calcium and phosphorus ions. A subsequent release of proteolytic enzymes in the tissues may be set free the bound iones and, thus, initiate mineralization.

Calcium↗

Dissociation of human adult epidermal cells by disulfide-reducing agents and subsequent trypsinization.

Primary cultures of epidermal cells from human adult skin were dissociated by dithiothreitol (DTT) with subsequent trypsinization. After treatment with disulfide reducing agents, the desmosomes were either destroyed or showed a homogeneous ultrastructure. Trypsin separated the homogeneous desmosomes, whereas cell membranes, organelles, and nuclei remained undamaged. Trypsin did not influence normal desmosomes. A suspension of human epidermal cells was recultivated in new flasks. Two types of cells grew in the cultures--polygonal and spindle-shaped. The polygonal cells were maintained for 30 to 60 days and grew slowly. The spindle-shaped cells were leucine-amino-peptidase negative, grew actively, and were subcultured.

Adult↗

Separation of human epidermal cells from fibroblasts in primary skin culture.

To obtain pure culture of epidermal cells from small human biopsies, two different techniques were tested and compared, i.e. separation of epidermis from corium before cultivation by trypsin and suction, and after cultivation by trypsin and collagenase. The most active growth of epidermal cells was obtained by the third technique, since short-term trypsin treatment released only fibroblasts from the culture. Crude collagenase (type I) was less effective than trypsin. Collagenase type II, III and IV had no effect on fibroblast release. Neither trypsin nor collagenases dispersed epidermal cells.

Biopsy↗

Suction blister transplantation for leg ulcers.

Application of suction blister transplants to leg ulcers is an alternative symptomatic treatment to split-skin grafting, i.e. "pinch-grafting". Blisters are produced by the suction device Dermovac at a suction pressure of 250-300 mmHg for 1-2 hours. The blister-roofs are cut off at the periphery and placed on the granulation tissue of the ulcer. The healing time for leg ulcers was 10-14 days. Excellent epithelialization was seen in 10 out of 12 ulcers. The advantages of the method are, that it is easy to perform, no scarring is produced, and the procedure is painless.

Blister↗

Treatment of chlamydial urethritis in men and Chlamydia trachomatis-positive female partners: comparison of erythromycin and tetracycline in treatment courses of one week.

Seventy-one consecutive men who had Chlamydia trachomatis-positive nongonococcal urethritis were assigned randomly to treatment for one week with either tetracycline or erythromycin (1g daily). Seventy men completed the study. At follow-up, there were two therapeutic failures among 36 patients treated with erythromycin, and two failures among 34 patients treated with tetracycline. Twenty-four C. trachomatis-positive female contacts were randomly assigned to treatment regimens similar to those of the men. There was one treatment failure among 12 women treated with erythromycin, and no failure among 12 treated with tetracycline. In this study the urethral smears contained fewer than five leukocytes per high-power field in 16% of the C. trachomatis-positive men with symptoms suggestive of urethritis.

Adolescent↗