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Biomedical subjects

K Herrmann

Publications and source records attributed to K Herrmann.

At least 19 recordsLinked to original sources
PubMed1992

[Chemically-induced scleroderma].

Scleroderma-like diseases can be induced by a number of chemical compounds, such as plastics, solvents and drugs. Contaminated rapeseed oil was the cause of the toxic oil syndrome and L-tryptophan induces the so-called eosinophilia-myalgia-syndrome. On the other hand, paraffin and silicon can trigger so-called adjuvant disease, while long-term exposure to silica can lead to idiopathic scleroderma (associated with silicosis in some cases). In addition to the clinical features, some pathogenetic data in the literature, such as genetic factors (HLA, chromosomal anomalies, enzyme deficiencies) and the metabolism of chlorinated ethylenes via reactive epoxide intermediate products, and our own findings are reported. Silica-induced scleroderma cannot be distinguished from the idiopathic form by epidemiological, clinical or immunological studies or by parameters referring to the blood vessels or collagen metabolism. In cell culture studies it has been shown that macrophages/monocytes release IL1, IL6 and TNF after ingestion of silica, which affects fibroblasts, T-helper cells and endothelial cells. Comparative results from the silicosis literature are reported. Finally, the possibly stimulating role of ionizing irradiation (uranium mining) in favouring the development of scleroderma is discussed.

Ethylenes↗
PubMed1991

Lesions of HVc block the developmental masculinizing effects of estradiol in the female zebra finch song system.

The neural song control system of female zebra finches is permanently masculinized if the females are given estradiol within 1 month after hatching. One hypothesis is that estradiol acts on neurons in the caudal nucleus of the ventral hyperstriatum (HVc) to cause developmental changes that lead to masculinizing influences in other song control regions. To test whether lesions of HVc block the masculinizing effects of estradiol elsewhere in the song system, we gave 20-day-old females either a Silastic pellet containing estradiol or no implant, and they received either a unilateral lesion of HVc or no lesion. At 60 days of age, they were sacrificed. The volumes of brain regions and sizes of neurons were measured in four song nuclei: HVc, robust nucleus of the archistriatum (RA), lateral magnocellular nucleus of the neostriatum (IMAN), and Area X. Lesions of HVc blocked the masculinizing effects of estradiol on RA and Area X on the side of the lesion. Thus, HVc must be intact in order for estradiol to masculinize these two nuclei. This observation is compatible with the hypothesis that estradiol acts on or near HVc to masculinize several song nuclei, although other interpretations are also possible.

Animals↗
PubMed1991

Remodeling of retinal ganglion cell dendrites in the absence of action potential activity.

The dendrites of ganglion cells in the retina have an excess number of spines and branches that are normally lost during the first postnatal month of development. We investigated whether this dendritic remodeling can be prevented when the action potential activity of ganglion cells is abolished by chronic intraocular injections of tetrodotoxin (TTX) during the first 4 or 5 postnatal weeks in the cat. Dendritic tree morphologies of alpha and beta ganglion cells from TTX-treated, non-TTX-treated (contralateral eye), and normal control retinae were compared after intracellular filling with Lucifer yellow. Qualitative observations and quantitative measurements indicate that TTX treatment does not prevent the normally occurring loss of spines and dendritic branches. Indeed, the dendritic trees of both alpha and beta cells in TTX injected eyes actually have even fewer spines and branches than normal cells at equivalent ages. However, because the total dendritic lengths of these cells are also reduced after TTX blockade, spine density is indistinguishable from untreated animals at the same age. In addition, although dendritic field areas are not altered with treatment, the complexity of the dendritic trees is reduced. These observations suggest that dendritic remodeling can occur in the absence of ganglion cell action potential activity. Thus, the factors that influence the dendritic and axonal development of retinal ganglion cells must differ, because similar TTX treatment during the period of axonal remodeling does have profound effects on the final pattern of terminal arborizations.

Action Potentials↗
PubMed1991

Steady-state mRNA levels of collagens I, III, fibronectin, and collagenase in skin biopsies of systemic sclerosis patients.

Total RNA was extracted from skin biopsies of nine patients suffering from systemic sclerosis (SSc). Steady-state mRNA levels of collagen alpha 1(I) and alpha 1(III), collagenase, fibronectin, and beta-actin were studied using specific cDNA probes and compared to those of 12 sex- and age-matched healthy individuals. There was a more than three-fold elevation of collagen I mRNA levels in SSc skin compared to controls. No difference was found, however, for collagen III, collagenase, and fibronectin mRNA levels in SSc and control biopsies. The selective increase of collagen alpha 1(I) mRNA levels indicates a specific alteration of fibroblast metabolism in scleroderma. Analysis of mRNA levels in skin biopsies might not only offer a direct approach to the understanding of the pathophysiology of SSc, but also facilitate the monitoring of fibrotic activity in SSc patients during therapeutic trials.

Adult↗
PubMed1991

The development of afferent projections to the robust archistriatal nucleus in male zebra finches: a quantitative electron microscopic study.

Because the projections into the robust nucleus of the archistriatum (RA) are thought to play important roles in song learning and sexual differentiation of the zebra finch (Poephila guttata), quantitative electron microscopic techniques were used to measure the development of synaptic input to the neuropil of RA in this species. Two nuclei [hyperstriatum ventrale pars caudalis (HVc) and lateral magnocellular nucleus of the anterior neostriatum (IMAN)] that send projections to RA were lesioned at each of three different ages: 25 d after hatching, 53 d, and adulthood. In tissue from RA processed for conventional electron microscopy, lesion-induced degeneration was used to identify synapses from either HVc or IMAN. Axosomatic synapses were excluded from analysis. In control (unlesioned) animals, the density of synapses in neuropil increased slightly between days 28 and 56 and remained constant thereafter. Because of a large increase in the volume of RA, the total number of synapses in neuropil of RA tripled between days 28 and 56 and decreased significantly between day 56 and adulthood. The density and total number of synapses in neuropil originating from HVc increased significantly between days 25 and 53, but did not change significantly thereafter. In contrast, the density and total number of synapses from IMAN decreased significantly between days 25 and 53 and did not change thereafter. Presynaptic terminals from IMAN were larger than those from HVc. These data demonstrate that the most rapid phase of song learning is accompanied by a major rearrangement of synaptic contacts into RA that stem from HVc and IMAN.

Afferent Pathways↗
PubMed1990

Silica-induced scleroderma.

In a survey done in East Germany between 1981 and 1988, we found that 93 of 120 male scleroderma patients had long-term exposure to silica dust. We describe our findings in 12 patients with scleroderma and silicosis. The exposure time to silica dust was between 3 and 34 years; the interval between the beginning of exposure and the onset of scleroderma averaged 27.3 years (range 9 to 40 years). Antinuclear antibodies in titers between 80 and 10,240 with nucleolar and/or speckled patterns were found in 10 patients, antibodies against double-stranded DNA in three, Scl-70 (topoisomerase I) in three, and anticentromere antibodies in five. The following markers of collagen metabolism were increased in serum: beta-galactosidase in 12 patients, laminin peptide-P1 in 10 patients, N-terminal procollagen type III peptide in 10, and urinary sialic acid excretion in 7. We propose that crystalline particles of silica less than 5 microns may be phagocytosed by macrophages and release lymphokines and monokines, which activate fibroblasts and enhance their collagen and glycosaminoglycan synthesis. In addition, silica may act as an adjuvant to increase immune reactivity.

Biopsy↗
PubMed1990

Type III collagen aminopropeptide and laminin P1 levels in serum of patients with silicosis-associated and idiopathic systemic scleroderma.

A group of 191 patients with systemic scleroderma and 12 patients with silicosis-associated scleroderma were investigated for connective tissue turnover. The serum levels of type III collagen aminopropeptide (P-III-P), the laminin PI (Lam PI) fragment and the acid lysosomal beta-galactosidase (beta-Gal) were determined by specific radioimmunoassays and spectrofluorometry, respectively. Increased levels of type III collagen aminopropeptide strongly correlated with enhanced activity of beta-galactosidase. Both parameters correlated with the clinical course in idiopathic systemic scleroderma and in silicosis-associated scleroderma. Serum levels of Lam PI were also found to be elevated in both groups, although there was no correlation with the severity of the disease. Autoantibodies directed against the DNA topoisomerase Scl-70 and against centromeric proteins were found in a similar range in patients with idiopathic systemic and silicosis-associated scleroderma. These results suggest that P-III-P, Lam PI and beta-Gal are useful serological markers of fibrotic activity and demonstrate similarities between idiopathic systemic scleroderma and scleroderma associated with silica-dust exposure.

Aged↗
PubMed1990

[N-procollagen(III)peptide and lysosomal beta-galactosidase in progressive scleroderma and silicosis].

The concentration of type III collagen aminopropeptide and the activity of lysosomal beta-galactosidase were determined in the serum of patients with progressive sclerosis (PS), silicosis and PS associated with silicosis. In PS-patients, the serum levels of both parameters were significantly increased with a high correlation to the stage of the disease and to each other. In patients with silicosis normal serum concentrations of both parameters were found, whereas in all patients suffering from silicosis and PS significantly elevated serum levels were detectable, independent of the stage of PS. Both parameters can also be used as markers of therapy (e.g. with D-penicillamine) and as early indicators for the development of PS in patients with silicosis.

Adult↗
PubMed1990

[Early detection of scleroderma in quartz dust exposed workers and workers with silicosis by determining serum beta-galactosidase activity].

Progressive systemic sclerosis (PSS) is a rare disease belonging to the collagen diseases. PSS is frequently observed in workers with an intensive exposure to crystalline silica and with silicosis in the GDR. The recognition as an occupational disease is regulated by law. The elevated beta-galactosidase activity in the serum of patients with silicosis and beginning PSS can be used for detecting of early stages of PSS. References are given to medical care of patients with silicosis and exposure to quartz.

Adolescent↗
PubMed1990

[Pelvimetry using computerized tomography. I. Theoretical and methodical fundamentals].

The first part of our article deals with the basic aspects of using computed tomography in obstetrical pelvimetry. A macerated osseous female pelvis was used to measure the true conjugate, the transverse plane of the pelvic inlet, the interspinous line and the distance between the ischial tuberosities. The same pelvis was then examined computed tomographically. A lateral and a posterior-anterior scan, and a single scan through the iliac spines were performed. The results of the direct measurement agreed highly with the values achieved computed tomographically if the phantom was positioned exactly on the mid-line of the examination-table, if not, the true conjugate was elongated. Measurements of the superficial and the intravaginal radiation dose in patients demonstrated a significantly lower risk in computed tomography than in conventional x-ray methods. We recommend computed tomography in obstetrics as a safe, accurate and reliable method.

Female↗
PubMed1989

Occurrence and content of hydroxycinnamic and hydroxybenzoic acid compounds in foods.

Phenolic acid compounds seem to be universally distributed in plants. They have been the subject of a great number of chemical, biological, agricultural, and medical studies. Hydroxycinnamic acid compounds occur most frequently as simple esters with hydroxy carboxylic acids or glucose, while the hydroxybenzoic acid compounds are present mainly in the form of glucosides. Furthermore, phenolic acids may occur in food plants as esters or glycosides conjugated with other natural compounds such as flavonoids, alcohols, hydroxyfatty acids, sterols, and glucosides. Also, hydroxycinnamic acid amides appear to be common constituents. The occurrence of the different natural phenolic acid compounds in foods is reviewed, and data of the content in fruit, vegetables, and spices are given. The distribution of the main phenolic acid compounds in food plants as well as their changes during development and maturation of fruits are considered. Furthermore, the hydroxycinnamic acids bound to cell wall polymers, the phenolic acid compounds in coffee, cereals, oil seed, and tree nuts, and the analysis of phenolic acid derivatives are reviewed.

Cinnamates↗
PubMed1989

[Function of the spermatozoal plasma membrane in oocyte fertilization. Cell electrophoresis and immunofluorescence microscopy studies].

The influence of the capacitation on the electric charge of the spermatozoal surface and the unspecific spermatozoon-oocyte-binding are not fully understood up to now. Therefore, human semen samples were divided into two subgroups of spermatozoa by the "swim up" method. Both of the subgroups were examined by means of the micro-electrophoresis and the immunofluorescence technique using antihuman fibronectin antibodies. Cellular electrophoresis: The 2 subgroups of spermatozoa prepared of one semen sample showed a significantly different electrophoretic mobility (EPM) after washing and resuspension in an isotonic glycin-HCl-buffer (pH 2.0). In contrast, after resuspension in Baker's-buffer (pH 7.4) no difference between the 2 subgroups of one semen sample was detectable. The incubation in a medium with Ca++ caused secondly alterations of the EPM with the result of a smaller difference between the two subgroups of spermatozoa. Albumin also modified the EPM of spermatozoa. Immunofluorescence technique: 69 per cent of spermatozoa with a normal shape and only 17 per cent of them exhibiting a pathological shape showed a positive fibronectin-fluorescent-band on the equatorial segment called equatorial fibronectin band (EFB). Spermatozoa separated by "swim up" from semen samples with various semen parameters showed different percentages of spermatozoa with EFB. There was a significant difference between the spermatozoa of the two subgroups after "swim up" concerning EFB.

Electrophoresis↗
PubMed1989

[HLA-A, B, C phenotype frequencies in progressive systemic scleroderma].

In 41 patients suffering from progressive systemic sclerosis (PSS) the phenotype frequencies of 28 HLA-A, B, C antigens were determined. Compared to 2947 blood donors the PSS patients exhibited an increase in the HLA-B8 frequency (37% versus 19%). This difference revealed to be not significant after the correction according to the number of antigens tested. The same was with the increase in the frequency of HLA-B5, B13, B27, Cw2 and the decrease in the frequency of HLA-A2, B12, B14, B15, B4 and Cw3. The results were compared with the data reported in the literature. Additionally, there were no differences when compared the diffuse PSS with the acral form and CREST, respectively.

Adolescent↗
PubMed1988

Development of neurons in the ectostriatum of normal and monocularly deprived zebra finches: a quantitative Golgi study.

The postnatal development of the main neuron type in the ectostriatum, the telencephalic station of the tectofugal pathway, was followed in normally reared and monocularly deprived zebra finches by using the Golgi method. Three parameters were investigated: dendritic field radius, branching index, and spine density. The results show that all three exhibit the same developmental trend--namely, an increase from day 5 until day 20, followed by a subsequent reduction until adulthood (greater than 100 days). Monocular deprivation from birth until day 20, 40, or at least 100 does not seem to interfere with the development of the dendritic field radius or branching index. Clear changes in spine density result from depriving the birds for at least 40 days. In these birds, neurons in the deprived hemisphere bear significantly fewer spines than those in the nondeprived hemisphere, which is mainly due to a lack of normally occurring spine reduction in the nondeprived hemisphere rather than to spine reduction in the deprived hemisphere.

Aging↗