Biomedical subjects

E Schulze

Publications and source records attributed to E Schulze.

At least 19 recordsLinked to original sources

PubMed2002

The Caenorhabditis elegans ortholog of human PHF5a shows a muscle-specific expression domain and is essential for C. elegans morphogenetic development.

We have recently described a novel human and murine multigene-family that is highly conserved during evolution and shows a PHD-finger-like domain present in the deduced protein sequences. Here, we describe the cloning and characterization of the Caenorhabditis elegans ortholog of human PHF5a. Transgenic phf-5::yfp-reporter techniques in C. elegans identified temporal C. elegans phf-5 expression being restricted to late C. elegans development. The phf-5::yfp expression starts within the morphogenetic phase of embryonic development and lasts to the stage of adult worms. Spatial phf-5 expression is muscle-specific with an expression in the developing pharynx, in body wall muscular structures, and in the anal muscles. By phf-5 RNAi we further demonstrated that PHF-5 is essential in the morphogenetic phase of C. elegans embryonic development as well as in young larvae. In contrast, phf-5 RNAi does not show an evident phenotype to adult worms. Taken together, this is the first report providing evidence for a tissue and stage-specific expression of a PHF5a ortholog, named phf-5, in C. elegans while our data further suggest an essential role of the encoded PHF-5 protein in morphogenetic development and muscle function.

Amino Acid Sequence↗

PubMed2002

Phenotypic characterization of mononuclear and multinucleated cells of giant cell reparative granuloma of small bones.

Four cases of giant cell reparative granuloma (GCRG) of small bones were analysed in order to determine the pathogenesis of the lesion and the nature of the component mononuclear and multinucleated cells. In cell cultures, giant cells formed a non-proliferating homogeneous population which expressed features characteristic of the osteoclast phenotype, including leucocyte common antigen, CD68, vitronectin receptor, and tartrate-resistant acid phosphatase. The giant cells were capable of lacunar resorption and their activity was inhibited by calcitonin. In addition to numerous macrophage-like cells, some of which expressed osteoclast phenotypic characteristics, there were also mononuclear stromal cells which proliferated in culture and were alkaline phosphatase-positive; these cells expressed receptor activator of NF-kappaB ligand (RANKL) and were capable of supporting human osteoclast formation from circulating precursors in vitro. These findings suggest that the osteoclast-like giant cells in GCRG of small bones are formed from monocyte/macrophage-like osteoclast precursors which differentiate into osteoclasts under the influence of mononuclear osteoblast-like stromal cells.

Adult↗

PubMed2002

The influence of serum cytokines and growth factors on osteoclast formation in Paget's disease.

BACKGROUND: Osteoclasts are multinucleated cells (MNCs) that form from circulating mononuclear precursors in the presence of the receptor activator of nuclear factor kappa B-ligand (RANKL) and macrophage-colony stimulating factor (M-CSF). AIM: To determine whether cytokines and growth factors influence RANKL/M-CSF induced osteoclastogenesis and bone resorption in Paget's disease. DESIGN: Prospective case-control study. METHODS: Serum levels of M-CSF, interleukin (IL)-1 beta, IL-6 and tumour necrosis factor-alpha (TNFalpha) were measured in 13 Paget's disease patients and 8 normal controls. The effect of serum from Paget's patients on osteoclast formation was also assessed. RESULTS: Serum levels of IL-1 beta, IL-6 and TNFalpha were low or undetectable in Paget's disease patients and normal controls. Levels of M-CSF were significantly increased in Paget's patients who were not currently under treatment. In Paget's patients under treatment, serum M-CSF levels were not significantly different from normal controls. The addition of serum from untreated Paget's patients dose-dependently increased RANKL-induced osteoclast formation and lacunar resorption in normal monocyte cultures; elevated IL-6 levels were found in the supernatant and the addition of a specific antibody to human IL-6 blocked the increase in osteoclast formation and resorption. Serum from untreated Paget's patients also induced osteoclast formation in the absence of exogenous M-CSF; an antibody specific to human M-CSF abolished this effect. DISCUSSION: Both M-CSF and IL-6 play a major role in osteoclast formation and bone resorption in Paget's disease and measurement of serum M-CSF may provide a useful indicator of disease activity.

Adult↗

PubMed2002

New indolocarbazoles as antitumour active compounds: evaluation of the target by experimental and theoretical studies.

A series of indolocarbazoles was synthesized as congeners of the natural lead compounds rebeccamycin (1) and staurosporine (2) which reduce cell growth by inhibiting topoisomerase I and protein kinase C respectively. Two of the carbazoles (3 and 4) screened at the National Cancer Institute (NCI, USA) showed an interesting cytotoxic activity and were therefore further analysed. The mechanism of action of these two compounds was studied experimentally using different assay to determine the B-DNA binding ability and the inhibition of topoisomerase I and of protein kinase C. Theoretical molecular modelling studies were also performed to describe the possible interactions with protein kinase C and DNA.

Antineoplastic Agents↗

PubMed2001

[The extralobar sequestration of the fetal lung].

The extralobar sequestration is a rare pulmonary malformation. An accurate antenatal evaluation is required for a timely therapy and subsequently a good outcome. Here an unusual case of extralobar pulmonary sequestration in a male human fetus is reported. Antenatal ultrasound at 28th week of gestation has revealed a fetal hydrothorax in coexistence with pulmonary hypoplasia and an isolated pulmonary structure. Authors summarise their postnatal findings with special reference to the pathogenesis of an accessory lung. The aim of this report is to define the association of clinical, gross, and histological features of this rare congential malformation in order to improve the antenatal diagnosis. This case indicates that an extralobar pulmonary sequester is not connected to the tracheobronchial tree, and that the arterial as well as the venous blood supply is realised by aberrant systemic vessels. Moreover, histologically revealed dilatations of the normally differentiated terminal airways within the sequester suggest that hyperechogenity can not be a reliable diagnostic criterion. For the accurate assessment of a pulmonary sequestration a detailed antenatal evaluation of both, the arterial and the venous blood supply is essential.

Adult↗

PubMed2001

Monarthritis of the ankle as manifestation of a calcaneal metastasis of bronchogenic carcinoma.

We report a case of bronchiogenic carcinoma metastasizing to the calcaneus and clinically manifesting itself as a therapy-refractory monarthritis in the right ankle. There is a wide spectrum of possible diagnoses of acute ankle monarthritis including different forms of inflammatory rheumatic diseases, sarcoidosis, osteoarthritis, or septic arthritis. Primary or metastatic malignancies of the hand or foot bones are considered to be rare. Persistent monarthritis as a sole symptom of a calcaneal metastasis has never been reported. This case demonstrates possible difficulties in the early differential diagnosis of acute monarthritis, and will be discussed with respect to the few reports on foot acrometastases.

Aged↗

PubMed2001

Synergistic effect of titanium alloy and collagen type I on cell adhesion, proliferation and differentiation of osteoblast-like cells.

A number of studies have demonstrated the pivotal role of collagen in modulating cell growth and differentiation. In bone, where the extracellular matrix is composed of approximately 85% type I collagen, cellular interaction with matrix components has been shown to be important in the regulation of the osteoblast phenotype. Preservation or enhancement of normal osteoblast function and appositional bone formation after implant placement represents a strategy that can be useful for the purpose of improving osseointegration. In order to further improve biocompatibility, we combined two known favorable compounds, namely the titanium alloy, Ti6A14V, with type I collagen. We assessed the in vitro behavior of primary osteoblasts grown on both fibrillar collagen-coated and tropocollagen-coated Ti6A14V in comparison with uncoated titanium alloy, using an improved adsorption procedure. As parameters of biocompatibility, a variety of processes, including cell attachment, spreading, cytoskeletal organization, focal contact formation, proliferation and expression of a differentiated phenotype, were investigated. Our results demonstrated for the first time that in comparison to uncoated titanium alloy, collagen-coated alloy enhanced spreading and resulted in a more rapid formation of focal adhesions and their associated stress fibers. Growing on collagen-coated Ti6A14V, osteoblasts had a higher proliferative capacity and the intracellular expression of osteopontin was upregulated compared to uncoated titanium alloy. Type I collagen-coated titanium alloy exhibits favorable effects on the initial adhesion and growth activities of osteoblasts, which is encouraging for its potential use as bone graft material. Moreover, collagen type I may serve as an excellent biocompatible carrier for osteotropic factors such as cell adhesion molecules (e.g. fibronectin) or bone-specific growth factors.

Alloys↗

PubMed2001

Mutational spectrum of the steroid 21-hydroxylase gene in Austria: identification of a novel missense mutation.

This study attempted an analysis of the mutational spectrum of 21-hydroxylase deficiency in 79 unrelated Austrian patients with classical and nonclassical forms of congenital adrenal hyperplasia and their respective 112 family members. Apparent large gene deletions/conversions were present in 31% of the 158 unrelated congenital adrenal hyperplasia alleles, whereas the most frequent point mutations were intron 2 splice (22.8%), I172N (15.8%), V281L (12%), and P30L (7.6%), in line with the frequencies reported for other countries. In 5 of the 12 congenital adrenal hyperplasia alleles carrying a P30L mutation the aberration is based on a single base substitution, whereas the remaining 7 represent part of a CYP21B conversion (1 allele) or CYP21B/21A hybrid gene (6 alleles), the latter characterized by a junction site before intron 2 as indicated by Southern blot, PCR, and sequence analyses. Previously described mutations were not present in 1.2% of unrelated congenital adrenal hyperplasia alleles, including one female patient presenting with severe genital virilization. Sequence analysis of the complete functional 21-hydroxylase gene revealed an as yet undescribed mutation in exon 10-Arg(426)His, which has not yet been described to represent a common pseudogene sequence. In vitro expression experiments showed the Arg(426)His mutant to exhibit only low enzyme activity toward the natural substrate 17-hydroxyprogesterone corresponding to the degree of disease manifestation in the patient in whom it was found.

Adrenal Hyperplasia, Congenital↗

PubMed2001

A single histone H1 isoform (H1.1) is essential for chromatin silencing and germline development in Caenorhabditis elegans.

In remarkable contrast to somatic cells, the germline of the nematode Caenorhabditis elegans efficiently silences transgenic DNA. The molecular mechanisms responsible for this have been shown to implicate chromatin proteins encoded by the mes genes (Kelly, W. G. and Fire, A. (1998) Development 125, 2451-2456), of which two are the C. elegans homologs of Polycomb Group gene transcriptional repressors. We have analyzed the contribution of the histone H1 gene family to this specific aspect of germ cells in C. elegans. We show with isotype-specific double stranded RNA-mediated interference (RNAi) that a single member of this gene family (H1.1) is essential for the repression of a silenced reporter-transgene in the germline of hermaphrodites and males, whereas no change is found in the somatic expression of this reporter. Additionally, RNA-mediated interference with H1.1 gene expression can cause a phenotype with severe affection of germline proliferation and differentiation in the hermaphrodite, and even sterility (5%-11% penetrance). These and further features observed in histone H1.1 RNAi experiments are also characteristic of the mes phenotype (Garvin, C., Holdeman, R. and Strome, S. (1998) Genetics 148, 167-185), which is believed to result from the desilencing of genes required for somatic differentiation in the germline. Our observations therefore support this interpretation of the mes phenotype and they identify a single histone H1 isoform (H1.1) as a new component specifically involved in chromatin silencing in the germline of C. elegans.

Amino Acid Sequence↗

PubMed2000

[Diarrhea as the initial manifestation of medullary thyroid gland carcinoma].

BACKGROUND: With the differential diagnosis of a diarrhea a lot of causes has to be considered. In very rare cases diarrhea can be the first symptom of a medullary thyroid carcinoma (MTC). CASE REPORT: A 28-year-old patient came to the admission department because of persisting diarrhea. A computerized tomography revealed multiple hepatic and pulmonary metastases. A medullary thyreoid carcinoma was found as the cause of it. The serum calcitonin values were highly increased, later the carcinoembryonal antigen (CEA), too. Sandostatin, a radioimmune therapy (131J-anti-CEA antibody) and adriamycin were therapeutically applied. The patient died 24 months after the occurrence of the first symptoms. CONCLUSION: In case of persisting diarrhea the differential diagnosis of a medullary thyroid carcinoma must be taken into consideration and a calcitonin determination has to be arranged. Yet, typical symptoms like struma nodosa, swollen neck lymph nodes or a CEA increase can still be missing in the initial phase.

Adult↗

PubMed2000

X-ray microscopic studies of the Drosophila dosage compensation complex.

X-raymicroscopy is applied to detect specific proteins in whole cell nuclei of Drosophila melanogaster using immunogold labeling and silver enhancement. As a model for a small subnuclear structure the Drosophila dosage compensation protein MSL-1 was chosen. It associates with a number of other proteins to form a hetero-multiprotein complex, which elevates the transcriptional activity of the single X chromosome in males. This phenomenon is known as dosage compensation and is essential for the survival of male flies. The distribution of the Drosophila dosage compensation complex was studied by X-ray microscopy, because though the complex is expected to function by remodeling the structure of chromatin, its exact mode of action is not yet known. Many similar protein complexes are associated with different aspects of chromatin-mediated gene regulation in all eucaryotic organisms and can also be studied with the approach presented in this work. The distribution of MSL-1 protein in the nuclei of fixed D. melanogaster culture cells is visualized using the Göttingen X-ray microscope at the electron storage ring BESSY I. In addition to conventional and confocal laserscan fluorescence microscopy, X-ray microscopic investigations were performed at room as well as at cryogenic temperatures. The label can clearly be identified in the X-ray micrographs and shows detailed structure in the cell nuclei. Currently, X-ray micrographs show details in the cell nuclei about five times smaller than those in visible light micrographs.

Animals↗

PubMed2000

[Technology in residences for support of a self-determined life style for the elderly. The research project "sentha" and initial results of a social science project].

Sentha is an interdisciplinary research team involving the Technical University Berlin, the Berlin Institute for Social Research GmbH (BIS), the German Centre for Research on Ageing at the University of Heidelberg (DZFA), the School of Fine Arts Berlin (HdK), and the Brandenburg Technical University Cottbus (BTU). Building on empirical investigations of the role of everyday household products in the everyday life of older people, product-independent design and assessment guidelines and new products are being developed in an intensive interdisciplinary process in order to better meet the needs of older people and to enhance their autonomous living. The following paper describes the contributions from the participating disciplines and presents initial results of the social sciences subproject, describing the problems arising in living independently in old age and detecting the demands on new technological solutions. Data are based on a representative survey conducted in 1999 and including a stratified sample of 1417 men and women aged 55 and older.

Activities of Daily Living↗

PubMed2000

Characterization of caveolins from human knee joint catilage: expression of caveolin-1, -2, and -3 in chondrocytes and association with integrin beta1.

Interactions between the extracellular matrix (ECM) and chondrocytes are of great importance for structure and function of cartilage. The present study was undertaken to answer the question whether caveolins take part in integrin-mediated cell-ECM interactions in the human cartilage. In samples of human knee joint cartilage, we detected the caveolin subtypes -1, -2, and -3 by immunohistochemical methods. Double-label experiments revealed a colocalization of caveolin with beta1-integrin. Results of immunoprecipitation and immunoblotting assays show that beta1-integrins associate with all three caveolin subtypes in human chondrocytes and indicate that they are part of the same complexes. Furthermore, immunoelectron microscopy shows the localization of beta1-integrin in caveolae-like structures of the cell membrane. The data stimulate further investigations on the role of the caveolin-integrin complex for integrin-mediated signaling pathways in chondrocytes.

Cartilage↗

PubMed2000

Metabolism of glucocorticoids and mineralocorticoids in patients with adrenal incidentalomas.

BACKGROUND: Adrenal incidentalomas are mostly nonfunctioning adrenocortical adenomas (NFI). However, in 5%-12% of the patients a preclinical Cushing's syndrome (PCS) with autonomous cortisol production by the tumour is present. Since urinary free cortisol excretion is not sensitive enough to determine subclinical hypercortisolism, in the present study more sensitive indicators of daily cortisol production were measured. DESIGN: (1) Tetrahydrocortisol, tetrahydrocortisone, urinary free cortisone together with urinary free cortisol were measured in 35 patients with adrenal incidentalomas (29 NFI and six PCS) and in 35 healthy controls. (2) Since little is known about daily aldosterone production, aldosterone metabolite excretions were measured. (3) As recently reported, ACTH stimulation revealed an increased response of precursors of the glucocorticoid and mineralocorticoid pathway. To find out which steroidogenic enzymes have altered activities, a 1-24ACTH stimulation test (250 microg i.v.) was carried out in 25 patients and 18 healthy controls with determination of multiple steroids. (4) Finally, since it was assumed that 21-hydroxylase deficiency or even 11b-hydroxylase deficiency may be involved in adrenal tumourigenesis, the prevalence of germline CYP21B and CYP11B1 mutations were studied in the same patients, who had underwent the ACTH stimulation test. RESULTS: (1) Glucocorticoid metabolites were within the normal range in all but three patients with NFI. As a group, the patients had subtle alterations in cortisol metabolism. Tetrahydrocortisol excretion was elevated in NFI and PCS compared with normal subjects (2.1 +/- 0.2 and 2.5 +/- 0.5 vs. 1.5 +/- 0.1 mg 24 h(-1); P < 0.05). Accordingly, the twofold elevation of the tetrahydrocortisol/free cortisol ratio indicates an increased 5beta-reduction of cortisol in the liver. (2) Tetrahydroaldosterone and aldosterone-18-glucuronide excretions were not different to controls. (3) In patients with incidentalomas an increased response to ACTH was seen for 17-hydroxyprogesterone (595 +/- 133 vs. 160 +/- 25 ng dL(-1)), 21-desoxycortisol (105 +/- 25 vs. 29 +/- 9 ng dL(-1)) and 11-desoxycortisol (401 +/- 40 vs. 293 +/- 17 ng dL(-1)). (4) In only one of 25 patients, a heterozygous deletion in exon 3 of the CYP21B gene was detected. CONCLUSIONS: (1) In conclusion, even the excretion of the main glucocorticoid metabolites is not a marker sensitive enough to distinguish between NFI and PCS. However, it is also possible that alterations in cortisol secretion are qualitative rather than quantitative. (2) Zona glomerulosa function is not influenced. (3) The elevation of 21-desoxycortisol argues against an impairment of 11beta-hydroxylase and favours a decreased activity of 21-hydroxylase. All others had wild-type sequences of both genes. (4) In conclusion, neither 21-hydroxylase deficiency nor 11beta-hydroxylase deficiency are predisposing factors for adrenal tumourigenesis.

Adenoma↗

PubMed2000

Functionalized and [a]-anellated carbazoles as potential B-DNA ligands: experimental studies of DNA binding and molecular modeling of intercalation complexes.

Three synthetically available carbazole derivatives 3-5 were investigated for DNA binding (ethidium bromide displacement assay, DNA unwinding assay), for inhibition of topoisomerase I and for cell cytotoxicity (antitumour cell lines). In addition molecular modeling studies of DNA complexes were performed by semiempirical quantum chemistry, force field calculations and molecular dynamics calculations. In summary, combining the results from experiments and molecular modeling, the naphthoquinone anellated carbazole 4 emerges as a promising antitumour active candidate for further drug design studies in carbazole chemistry.

Animals↗

PubMed1999

Immunohistochemical investigations on the differentiation marker protein E11 in rat calvaria, calvaria cell culture and the osteoblastic cell line ROS 17/2.8.

Until now, many extracellular matrix proteins, e.g. osteopontin and osteonectin, have been used to determine a cell's osteogenic maturation. The disadvantage in evaluation of these proteins is their relative wide-ranging appearance throughout the osteogenic differentiation process. Thus, the aim of this study was to establish an immunohistochemical setup using E11, a marker that binds selectively to cells of the late osteogenic cell lineage. In addition, the histochemical expression of the bone matrix proteins osteonectin, osteopontin and fibronectin was compared to that of E11 using monoclonal antibodies. For light microscopical detection of osteogenic markers in cultured cells we developed a simple paraffin technique using a fibrin glue as embedding medium. This allows the handling of cultured cells such as a tissue sample and includes the use of stored biological specimens for further immunohistochemical experiments. We used newborn rat calvariae for whole tissue preparations and for isolation and cultivation of bone cells. In addition, we included the rat osteosarcoma cell line ROS 17/2.8 in this study. For the first time, we have localised E11 in osteocytes of rat calvaria preparations at the electron microscopical level. E11 was detected at plasma membranes of osteocytes and their processes, but not at those of osteoblasts. Accompanying experiments with cultured newborn rat calvaria cells and ROS 17/2.8 cells revealed E11 reactivity on a subset of cells. The results obtained confirm the suitability of the differentiation marker E11 as a sensitive instrument for the characterisation of bone cell culture systems.

Animals↗

PubMed1999

Immunohistochemical localization of the differentiation marker E11 in dental development of rats.

E11 antigen, originally characterized in a rat osteosarcoma cell line, is known to be expressed during late stages of the osteogenic cell lineage both in vitro and in vivo. The aim of the present study was to monitor the occurrence and distribution patterns of the E11 antigen using monoclonal antibodies (mAb E11 and MEP-1) during different stages of tooth germ development of new-born rats by means of immunohistochemistry. Both antibodies strongly bound to plasma membranes of ameloblasts in presecretory and secretory stages. In addition, odontoblasts and cells of the periodontium were immunoreactive for E11 and MEP-1. During maturation, the immunoreactivity of ameloblast plasma membranes decreased significantly. Our data suggest that E11 and MEP-1 might be important as markers for cell differentiation and mineralization processes during tooth germ development.

Ameloblasts↗

PubMed1999

Chronic liver injury alters basal and stimulated nitric oxide production and 3H-thymidine incorporation in cultured sinusoidal endothelial cells from rats.

BACKGROUND/AIM: Under pathological conditions the nitric oxide synthase (NOS)-mediated nitric oxide production of sinusoidal endothelial cells might be altered. Therefore, studies were performed to evaluate the nitrite formation by cultured sinusoidal endothelial cells from rat livers chronically injured by thioacetamide and the effect of endogenously or exogenously generated nitric oxide on their proliferative activity. METHODS: Basal and stimulated nitrite formation, expression of NOS and DNA synthesis were examined in sinusoidal endothelial cells isolated and cultivated from livers with incipient or advanced chemically-induced cirrhosis. RESULTS: Cultured sinusoidal endothelial cells from injured livers exhibited a reduced basal and an increased lipopolysaccharide-stimulated nitrite production when compared with controls. Western blot analysis revealed a markedly reduced protein expression of endothelial NOS (eNOS) and inducible NOS (iNOS) in sinusoidal endothelial cells from both experimental groups when compared with controls. Lipopolysaccharide stimulated iNOS expression in sinusoidal endothelial cells from control livers only marginally, and from those with cirrhosis more strongly. There was no clear correlation between the amount of enzyme and nitrite formation. Cultured sinusoidal endothelial cells from livers with incipient cirrhosis showed a higher proliferative activity than controls. Endogenously-produced nitric oxide inhibited DNA synthesis in all groups in a cGMP-independent way. Exogenously-generated nitric oxide affected DNA synthesis differently in sinusoidal endothelial cells from controls and injured livers. CONCLUSION: The results provide evidence that cultured sinusoidal endothelial cells from controls and livers with incipient or advanced cirrhosis differ with respect to basal and lipopolysaccharide-stimulated nitrite production. The data can be taken as evidence that in sinusoidal endothelial cells from livers chronically injured by thioacetamide, eNOS and iNOS are aberrantly expressed and differently regulated.

Animals↗