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Biomedical subjects

J Hollmann

Publications and source records attributed to J Hollmann.

At least 19 recordsLinked to original sources
PubMed1993

[Skin lipids in seborrhea- and sebostasis-associated skin diseases].

Recent studies suggest that epidermal skin lipids play an important role in the pathogenesis of skin diseases associated with seborrhoea or sebostasis. Depending on the state of the skin, various lipids are found in varying quantities and proportions. In some sebostatic diseases, in particular, altered enzyme activities relevant to the synthesis of lipids have been identified, which may account for alterations in epidermal lipid fractions. This concept represents a substantial modification of earlier ones, according to which sebostatic or seborrhoeic skin diseases were attributed solely to decreased or increased sebum lipids, respectively. This provides an important rationale for a new approach to the therapy of certain skin diseases with specific lipid fractions, such as ceramides.

Ceramides↗
PubMed1991

[Stratum corneum and nail lipids in patients with atopic dermatitis. Decrease in ceramides--a pathogenetic factor in atopic xerosis?].

Dry skin is seen in many patients with atopic dermatitis and correlates with a disturbed epidermal barrier function demonstrated by such features as increased transepidermal water loss and diminished stratum corneum hydration. With regard to the importance of stratum corneum lipids for the permeability barrier, we have analysed plantar (n = 8) and lumbar (n = 20) stratum corneum and nail lipids (n = 15) of atopic subjects by high-performance thin-layer chromatography (HPTLC). Compared with controls our investigations show a decrease in the ceramide fraction as a percentage of total lipid and a diminished ratio of ceramides and free sterols in atopic subjects. This implies that impaired ceramide synthesis may be a factor in the pathogenesis of atopic xerosis.

Dermatitis, Atopic↗
PubMed1989

Microanalytical screening of all major stratum corneum lipids by sequential high-performance thin-layer chromatography.

For rapid and sensitive screening of lipid biochemical abnormalities of scaling skin disorders a sequential, one-dimensional high-performance thin-layer chromatographic method (HPTLC) has been developed. All major human stratum corneum lipid classes, i.e., cholesterol sulfate, glucosylceramides, six major ceramide fractions, free sterols, free fatty acids, triglycerides, sterol esters, squalene, and n-alkanes, are separated and quantitated after a stepwise development of a single silica gel 60 HPTLC-plate using three consecutive solvent systems. Reproducible results have been obtained by degradative charring as well as fluorescence detection. By fluorescence detection the method is particularly suitable for the determination of minor amounts of cholesterol sulfate and other sterols.

Chromatography, High Pressure Liquid↗
PubMed1989

Autosomal dominant lamellar ichthyosis exhibits an abnormal scale lipid pattern.

Autosomal dominant lamellar ichthyosis (ADLI) is a recently recognized genetic skin disorder. Clinically and histologically, it cannot be distinguished with certainty from the more frequent autosomal recessive lamellar ichthyosis (ARLI), which in itself may still be heterogeneous. By ultrastructural examination of ADLI a prominent transforming zone between the stratum granulosum and stratum corneum and lipid inclusions in the stratum corneum have been observed. Using sequential high-performance thin-layer chromatography, we studied the plantar scale lipid pattern of two patients, mother and daughter, affected with ADLI. We found a distinctive alteration in the relative composition of the scale lipid pattern characterized by excessive amounts of free fatty acids, triglycerides, elevated n-alkanes, reduced free sterols and decreased total ceramides. This scale lipid profile clearly differs from that of the erythrodermic and non-erythematous variants of ARLI and confirms that this disorder is a distinct entity of the heterogeneous group of lamellar ichthyoses.

Alkanes↗
PubMed1988

Tyrosine O-sulfate ester in proteoglycans.

Tyrosine O-sulfate residues were detected in the protein core of sulfated proteoglycans. When cultured skin fibroblasts and arterial smooth muscle cells were incubated in the presence of [35S]sulfate, dermatan sulfate proteoglycan and chondroitin sulfate proteoglycan isolated from the culture medium contained tyrosine [35S]sulfate ester which accounted for 0.03%-0.82% of total 35S radioactivity incorporated into the sulfated proteoglycans. This corresponds to a tyrosine sulfation of every second (fibroblasts) and every 10th (smooth muscle cells) dermatan sulfate proteoglycan molecule. [3H]Tyrosine labeling of fibroblast dermatan sulfate proteoglycan gave a similar stoichiometry. However, the relative proportion of tyrosine [35S]sulfate in proteoglycans from arterial tissue was about 10 times higher than in that from cultured arterial cells. Pulse chase experiments with [35S]sulfate revealed that tyrosine sulfation is a late event in the biosynthesis of dermatan sulfate proteoglycan from fibroblasts and occurs immediately prior to secretion. Cultured skin fibroblasts from a patient with a progeroid variant (Kresse et al. 1987, Am. J. Hum. Gen. 41, 436-453) which exhibit a partial deficiency to synthesize dermatan sulfate proteoglycan were shown to form and to secrete a tyrosine-sulfated but glycosaminoglycan-free protein core, thus confirming a selective and independent [35S]sulfate labeling of the protein core.

Animals↗
PubMed1987

[Long-term follow-up of vena cava filters: real-time sonography and the native x-ray image].

In 16 patients with vena cava filters (12 Günther filters, 4 Kimray-Greenfield filters) a follow-up study was performed by ultrasound and abdominal plain film. Ultrasound allows to identify type and location of the filter as well as the entrapment of emboli. Abdominal radiography is useful for exact evaluation of changes in filter position. Combination of sonography and plain films is considered to be most suitable for follow-up studies of caval filters.

Adult↗
PubMed1987

Glycosaminoglycan-free small proteoglycan core protein is secreted by fibroblasts from a patient with a syndrome resembling progeroid.

A male patient, 4 years 9 mo old and having progeroidal appearance, exhibited delayed mental development and multiple abnormalities of connective tissues including growth failure, osteopenia of all and dysplasia of some bones, defective deciduous teeth, loose but elastic skin, delayed wound healing with formation of thin atrophic scars, scanty scalp hair, hypotonic muscles, and hypermobile joints. Skin fibroblasts of the patient converted only about half of the core protein of the small proteodermatan sulfate to a mature glycosaminoglycan chain-bearing proteoglycan. The remaining core protein, which contained complex-type asparagine-bound oligosaccharides, was secreted with almost normal kinetics. Xylosyltransferase activity and the synthesis of other proteoglycan types were normal. Normal induction of glycosaminoglycan synthesis occurred in the presence of 1 mM, but there was very little induction in the presence of 0.01 mM p-nitrophenyl-beta-xyloside. An antibody against an N-terminal pentadecapeptide of the core protein recognized the glycosaminoglycan-free core protein from the patient less well than the chain-bearing protein treated with chondroitin ABC lyase. Though these results do not define the basic defect unambiguously, they provide the first report of a disorder being due to an abnormality in small proteoglycan biosynthesis.

Abnormalities, Multiple↗
PubMed1986

Increased activity of chondroitin sulfate-synthesizing enzymes during proliferation of arterial smooth muscle cells.

Cultured arterial smooth muscle cells incorporate [35S]sulfate into the extracellular chondroitin sulfate/dermatan sulfate containing proteoglycans at a higher rate in the phase of logarithmic growth than do non-dividing cells. The cell growth-dependent decrease in 35S incorporation with increasing cell density is accompanied by a decrease in the activity of chondroitin sulfate-synthesizing enzymes. The specific activity of xylosyl transferase, N-acetylgalactosaminyl transferase I and chondroitin sulfotransferase declines as the cells proceed from low to high densities. The corresponding correlation coefficients are 0.86, 0.91 and 0.89. The ratio of C-6OH/C-4OH sulfation of chondroitin shows a cell proliferation-dependent decrease indicating an inverse correlation of chondroitin 6-sulfotransferase and chondroitin 4-sulfotransferase activity. The observed changes in the expression of enzyme activities are thought to have some implications in the pathogenesis of arteriosclerosis, the initial stages of which are characterized by proliferation of arterial smooth muscle cells.

Animals↗
PubMed1986

Purification and characterization of a 3'-phosphoadenylylsulfate:chondroitin 6-sulfotransferase from arterial tissue.

A 3'-phosphoadenylylsulfate:chondroitin sulfotransferase (EC 2.8.2.5) was purified to homogeneity (about 760-fold) from the cytosolic fraction of calf arterial tissue by Con A-Sepharose, ion exchange and affinity chromatography. The enzyme has a molecular mass of 38000 Da, optimal activity at pH 6.0 (100%) and 7.25 (75%), requires divalent cations for maximal activity (Mn2+ greater than Mg2+, Ca2+) and exhibits specificity towards desulfated chondroitin sulfate and oligosaccharides derived therefrom. The enzyme transfers sulfate groups from [35S]phosphoadenylylsulfate exclusively to C-6 OH groups of N-acetylgalactosamine units of the acceptor substrates. Maximal sulfate transfer occurs at 2mM chondroitin disaccharide units (100%), the transfer rates decreasing with decreasing chain length in the order deca (55%), octa (17%) and hexasaccharides (4%). Lineweaver-Burk plots revealed equal maximal velocities for chondroitin, deca-, octa- and hexasaccharide, but decreasing Km values. Chondroitin 4-sulfate has 21% of the acceptor potency exhibited by chondroitin, whereas dermatan sulfate, heparan sulfate and hyaluronate and the chondroitin tetrasaccharide showed no acceptor properties. Analysis of the reaction products formed by prolonged enzymatic sulfation of a reduced chondroitin hexasaccharide [GlcA-GalNAc]2-GlcA-GalNAc-ol revealed that the preterminal N-acetylgalactosamine from the non-reducing end and the internal N-acetylgalactosamine but not the N-acetylgalactosaminitol were sulfated and that no hexasaccharide disulfate was formed by the action of chondroitin 6-sulfotransferase. Chondroitin 6-sulfotransferase is considered to possess a binding region capable of accommodating a nonsulfated oligosaccharide sequence of at least six sugars and is believed to act in the course of chondroitin sulfate synthesis in cooperation with, but shortly after, the enzymes involved in the chain elongation reaction.

Animals↗
PubMed1984

Computed tomography of the intervertebral foramen.

52 cases with pathologic lesions in the intervertebral foramen, studied with CT, are analyzed. The most frequent lesions are intraforaminal disc herniations. These are characterized by their hyperdensity in comparison to the dural sac (34 of 34 cases) and their broad contact with the intervertebral disc space (31 of 34 cases). Foraminal size and contour are usually normal. In contradistinction to disc herniations, benign tumors often show bone erosion of the pressure-type with enlargement of the foramen. Bone infiltration was seen only in malignant lesions and in the single case of Echinococcosis. Preoperative diagnosis of vascular lesions which present with foraminal enlargement is most important for the choice of the appropriate operative approach. Correct CT diagnosis of such vascular lesions is only possible with dynamic CT.

Diagnosis, Differential↗
PubMed1983

[Contribution of computed tomography to the radiological clarification of a chondroma of the cervicothoracic spinal column].

On the basis of a chondroma which, as is well known, is very rarely found in the cervicothoracic spinal canal, the contribution made by computed tomography to the radiological identification of such benign tumours in explained. Morphology, localisation and incidence of chondromas and their differentiation against other tumours localised in the vertebral column, are discussed. The possibilities offered by the available diagnostic tools are compared with each other, also with regard to indication of operation and surgical planning.

Adolescent↗
PubMed1982

[Arthrography as a diagnostic measure in injuries of ligament and capsule of the ankle joint (author's transl)].

The application of monocontrast arthrography in examining the ankle joint is demonstrated by means of an extensive series of examinations. It is evident that this method of examination is more reliable than x-ray films of the forced extreme joint position, especially in combined injuries of the ligamentous apparatus, so that it enables better planning of the necessary therapeutic procedure.

Adolescent↗