Search PubMed⌕ Search

Biomedical subjects

H Spring

Publications and source records attributed to H Spring.

At least 37 records · Page 2Linked to original sources
PubMed1997

[General muscle rehabilitation practice].

This article presents a five-step approach to the rehabilitation of sports injuries. (1) pain management; (2) specific exercise instruction for treatment of localized functional disturbances/motion restrictions; (3) training therapy to increase localized and general physical performance; (4) patient education and instruction of an individualized home/gym program and for precautions and injury prevention; and (5) enhancement of psychological performance. Described are the negative sequelae of a sports-related injury or immobilization after surgery on joints, bones and circulatory system, with particular emphasis of the effects on the involved musculature. The negative impact of an injury on generalized physical performance is presented (deconditioning syndrome). The course of rehabilitation requires a specific functional diagnosis, so as to implement an individualized treatment plan. Regular and objective follow-up/monitoring is suggested within the context of projected goals. The specific steps are described. Pain and discomfort can impede the restoration process and must be addressed effectively. Even though many questions remain to be answered in the field of muscular rehabilitation, the present day knowledge coupled with successful empirical interventions allow the introduction of effective and efficient rehabilitation concepts.

Athletic Injuries↗
PubMed1997

Influence of 12(S)-hydroxyeicosatetraenoic acid (12(S)-HETE) on the localization of cathepsin B and cathepsin L in human lung tumor cells.

Cathepsins B and L are catabolic lysosomal enzymes but are likely candidates for extracellular proteolysis in normal and malignant processes. The signal mediator 12(S)-HETE selectively triggers a shot-gun release of cathepsin B. We have therefore investigated the intracellular distribution of cathepsins in unstimulated and 12(S)-HETE-stimulated tumor cells. Cathepsins B and L have only limited colocalization, which is found in the regions of synthesis and sorting (endoplasmic reticulum, Golgi, trans Golgi network). Treatment by 12(S)-HETE scatters cathepsin B but not cathepsin L and proform of cathepsin B. Colocalization with both mannose 6-phosphate receptors is very limited for both cathepsins. But extensive colocalization of cathepsin B and the endosomal/lysosomal marker CD63 (LIMP-I) documents the main fraction of the enzyme in these compartments. The supposed non-lysosomal fraction of cathepsin B is very likely the secretable material which follows a regulated secretory pathway. Storage and regulated secretion in tumor cells support extracellular proteolysis as a means in invasion which may lead to metastasis. But the mechanisms by which cells might acquire and eventually apply this means is still unknown.

12-Hydroxy-5,8,10,14-eicosatetraenoic Acid↗
PubMed1996

cDNA cloning of the hepatocyte canalicular isoform of the multidrug resistance protein, cMrp, reveals a novel conjugate export pump deficient in hyperbilirubinemic mutant rats.

ATP-dependent transport of glutathione and glucuronate conjugates from hepatocytes into bile is mediated by a distinct member of the ATP-binding cassette superfamily. We have cloned and sequenced the canalicular isoform of the multidrug resistance protein from rat liver, and termed it cMrp. This membrane glycoprotein is composed of 1541 amino acids with an identity of 47.8% with the human multidrug resistance protein (MRP) and of 41.9% with the yeast cadmium factor (YCF1). The carboxyl-terminal 130 amino acids of the human hepatocyte canalicular isoform of MRP (cMRP) were 80.2% identical with rat cMrp. cMrp was not expressed in the liver of two mutant rat strains, the Eisai hyperbilirubinemic rat and the GY/TR- mutant, which are deficient in the ATP-dependent transport of conjugates across the canalicular membrane. Immunoblotting using an antibody raised against the carboxyl terminus of cMrp detected the glycoprotein of about 190 kDa only in the canalicular membrane from normal liver. Double immunofluorescence and confocal laser scanning microscopy localized cMrp exclusively to the canalicular membrane domain of hepatocytes and demonstrated its loss in the hyperbilirubinemic mutant rat. The results identify cMrp as a canalicular transport protein with a novel sequence and with a function similar to the one of the MRP.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1996

Three-dimensional analysis of the substrate-dependent invasive behavior of a human lung tumor cell line with a confocal laser scanning microscope.

Matrigel and collagen G gels were used as models for basement membrane and interstitial space-collagen, respectively, to study the invasive behavior of cells of the human lung tumor cell line EPLC 32M1, which was derived from a squamous cell carcinoma. For three dimensional analysis of the invasive process, cells were seeded onto the gels in a slide chamber and observed with a confocal laser scanning microscope. Optical sectioning in the xy and xz directions and image reconstruction with computer programs allowed us readily to obtain a three-dimensional overview of the invasive process in situ. Both types of gel showed a smooth surface. Matrigel had a granular structure whereas collagen G revealed a fiber-like morphology. The tumor cells showed a matrix-dependent behavior. On Matrigel, within 24 h of incubation, a network of cells appeared on the surface, which developed further within 72 h to interconnected multicellular cords also invading the gel. Tumor cells seeded on collagen G remained individual. They formed pseudopodia and achieved tight contact with the matrix, eventually also invading the gels in a time-dependent manner. Therefore, the composition of the substrate crucially influences the invasion path.

Animals↗
PubMed1996

Multiparameter microscopic analysis of nucleolar structure and ribosomal gene transcription.

A survey of novel microscopic approaches for structural and functional analysis of subnucleolar compartments will be presented. Research on nucleolar structure and function concentrates predominantly on two distinct types of nucleoli: (1) nucleoli present during the interphase of the cell cycle in somatic tissue culture cells and (2) nucleoli present in meiotic cells, e.g. oocytes of amphibians. These nucleoli are found during meiotic prophase of oogenesis and are functional during several months of the diplotene stage of oogenesis. A further characteristic is the fact that these nucleoli are extrachromosomal, since they originate by selective ribosomal DNA (rDNA) amplification during the early pachytene stage of oogenesis. Miller-type chromatin spread preparations using transcriptionally active nucleoli, to a major part, contributed to our understanding of the structural organization of polymerase I directed pre-rRNA transcription. Although the structural organization of the template-associated pre-rRNA transcript is known in some detail from chromatin spreads, relatively little is known about structural aspects of pre-rRNA processing. In order to investigate this intriguing question in more detail, we have developed a computer-based densitometry analysis of both template-associated and template-dissociated pre-rRNA transcripts in order to follow the structural modification of pre-rRNA transcripts during processing. Another line of experiments is devoted to the in situ structure of actively transcribing genes in the nucleolus. In order to bridge the gap between light microscopy and electron microscopy we started video-enhanced light microscopical analysis of actively transcribing genes. Although the dimensions of individual spread genes are critical for detection by optical microscopy, we succeeded in obtaining the first series of images of transcribing genes in their "native' hydrated state. An additional promising type of microscopy is transmission X-ray microscopy. Recent progress in instrumentation as well as in sample preparation has allowed us to obtain the first images of density distribution within intact, fully hydrated nucleoli using amplitude-contrast and/or phase-contrast X-ray microscopy of non-contrasted, fully hydrated nucleoli at different states of transcriptional activity. Whereas the above mentioned investigations using video microscopy and X-ray microscopy are predominantly applicable to the analysis of amplified nucleoli in amphibian oocytes, which are characterized by an extremely high transcription rate of 80-90% of rDNA genes per individual nucleolus, structural analysis of the in situ arrangement of actively transcribing genes in somatic nucleoli as present in the interphase nucleus is far more difficult to perform, mainly due to the much lower number of simultaneously transcribed active genes per individual nucleolus. Visualization of actively transcribed gene clusters is approached by an integrated experimental assay using video microscopy, confocal laser scan microscopy, and antibodies against specific nucleolar proteins.

Animals↗
PubMed1996

Spatial arrangement of intra-nucleolar rDNA chromatin in amplified Xenopus oocyte nucleoli: structural changes precede the onset of rDNA transcription.

Amphibian oocyte nucleoli are a particular suited object for research on nucleolar chromatin organization. By selective rDNA amplification each pachytene oocyte nucleus accumulates 30 pg of extrachromosomal rDNA, this amount corresponds to 2 million rDNA copies. Following the selective amplification stage, the amplified gene copies are finally distributed within more than thousand extrachromosomal nucleoli per individual oocyte nucleus. The aim of the present study was first to obtain a precise documentation of the fate of amplified rDNA during early Xenopus oogenesis until the final functional integration of these copies into individual oocyte nucleoli, and, second, a close correlation of the structural data with determination of rDNA transcription rates by S1 transcript analysis for the subsequent stages of oocyte differentiation. In order to investigate the structural complexity of the intranuclear rDNA translocation process in detail, a confocal laser scan microscope (CLSM) was used, equipped with an external UV-laser. This instrumentation unambiguously allowed (i) the detection of small clusters of rDNA copies and (ii) the precise spatial documentation of the intranuclear position of rDNA clusters in relation to the protein-free pre-nucleolar protein bodies, a specific characteristic of late pachytene/early diplotene amphibian oocyte nuclei. Our results indicate that the major rDNA translocation processes, e.g. the association of rDNA clusters with pre-nucleolar protein bodies, the formation of ribbon-like pre-nucleolar units sensu Van Gansen and Schramm (J. Cell Sci. 10: 339-367, 1972), and, finally, the translocation of fused rDNA units into the interior of pre-nucleolar protein bodies, occur--for the most part--in absence of massive rDNA transcription. As shown by the S1 transcript analysis, the onset of massive rDNA transcription starts concomitantly with an unraveling of the densely packed rDNA clusters into finely dispersed rDNA units, which were shown by CLSM analysis to be distributed throughout the entire nucleolar volume.

Animals↗
PubMed1996

Interaction of microtubules with peroxisomes. Tubular and spherical peroxisomes in HepG2 cells and their alterations induced by microtubule-active drugs.

We have studied the interaction of microtubules with peroxisomes and the influence of changes in the microtubular network on the peroxisomal compartment. From the several cell lines analyzed for this purpose, HepG2 cells proved to be the best candidate exhibiting both a well-developed cytoskeleton and a peroxisomal compartment with great plasticity. Three distinct types of peroxisomes: small spherical (0.1-0.3 micron), rod-shaped (0.5 micron) and elongated tubular (up to 5 microns) ones were identified in this cell line. A shift of the elongated tubular forms to spherical particles was noted by increasing the density of cells in culture, whereas no correlation between the distinct peroxisomal forms and the cellular proliferation could be observed. At time points when the elongated tubular peroxisomes were disappearing, many spherical peroxisomes arranged like 'chains of beads on a string' were observed, suggesting that the fission of elongated tubular forms may give rise to newly developing spherical peroxisomes. A clear association of spherical peroxisomes with microtubules was visualized by double immunofluorescence in combination with confocal laser scanning microscopy (CLSM). Treatment with a variety of microtubule-depolymerizing drugs (colcemid, nocodazole, vinblastine) induced a significant increase in the frequency of tubular peroxisomes and led to the formation of peroxisomal clusters. These effects were reversible since already 1 to 2 h after removal of the drugs from the culture medium, a uniform distribution of spherical peroxisomes was reestablished. Taxol, a microtubule-stabilizing drug, on the other hand exerted no significant effects on the peroxisomal compartment. The direct interaction of microtubules with peroxisomes in vitro was demonstrated using highly purified rat liver peroxisomes and taxol-stabilized microtubules from bovine or pig brain. The binding of peroxisomes to microtubules was visualized by video-enhanced contrast microscopy (VECM) and was abolished by pretreatment of peroxisomes with 100 mM KCl ('stripping'), proteinase K or trypsin. Incubation with cytosol restored the binding capacity of KCl-treated peroxisomes, but did not complement the protease treatment. The data presented provide for the first time evidence for a direct interaction of microtubules with the peroxisomal compartment indicating that this cytoskeletal system plays an important role in the morphogenesis and intracellular distribution of peroxisomes.

Actin Cytoskeleton↗
PubMed1995

Cell surface-bound urokinase-type plasminogen activator facilitates infiltration of freshly isolated granulocytes into fibrin matrix.

Human cell lines of myelo/monocytic origin express the cellular receptor for urokinase-type plasminogen activator (uPA-R). The receptor localizes urokinase-type plasminogen activator (uPA) to the surface of the cell, where it can convert plasminogen to the active serine proteinase plasmin. Plasmin may subsequently account for proteolysis of pericellular proteins. We demonstrated the expression of the uPA-R by freshly isolated neutrophilic granulocytes by using a specific mAb. In freshly isolated granulocytes we detected only a weak occupation of the uPA-R; further uPA binding by granulocytes was saturable and proceeded in a dose-dependent manner. Receptor-bound uPA retained its enzymatic activity. Saturation of isolated granulocytes with exogenous uPA enhanced cellular infiltration into a fibrin matrix in vitro. uPA-dependent infiltration was inhibited by an anti-catalytic monoclonal anti-uPA antibody. The findings show that circulating neutrophilic granulocytes express the cell surface uPA-R and suggest that surface-binding of uPA may facilitate the infiltration of granulocytes into a fibrin clot, a process that might add to thrombolysis in vivo.

Cell Movement↗
PubMed1995

Differential expression of the microspike-associated protein moesin in human tissues.

The protein moesin is a member of a gene family consisting of talin, ezrin, radixin, protein 4.1., and merlin. Proteins of this family are associated to the submenbranous cytoskeleton. Using monoclonal antibody 38/87 directed against moesin in immunochemical analysis, the 78 kDa moesin protein was demonstrated in endothelial cells and in cells of carcinoma, mesothelioma and lymphoid origin. Moesin was metabolically labeled by [32P]orthophosphate and reacted with an antibody against phosphotyrosine. Moesin also contains carbohydrate residues as demonstrated by immunostainings of digoxigenin-labeled sugar residues. The antibody 38/87 in comparison to antisera against radixin and ezrin was applied in immunohistological stainings on various human tissues. As a prominent feature, moesin as strongly expressed in endothelium of vessels in contrast to radixin and ezrin. Moesin but not radixin was observed in T and B lymphocytes. Further, moesin was expressed in basal layers of squamous epithelium and glandular ducts and lymphocytes. Subcellular expression of moesin was studied on cultured human endothelial cells of umbilical cord veins and the mesothelioma cell line CH3LC by confocal laser scanning microscopy. In subconfluently growing cells moesin showed a characteristic expression on extending microspikes at the basal cell level. Moesin was coexpressed with actin in the cortical cytoskeleton and on microspikes but not in stress fibers. The differential cellular expression of moesin and its pronounced occurrence on microspikes of growing cells support the possibility that moesin is a protein involved in plasma membrane-cytoskeleton interactions in specialized tissues.

Antibodies, Monoclonal↗
PubMed1994

Urokinase-type plasminogen activator enhances invasion of human T cells (Jurkat) into a fibrin matrix.

The receptor for urokinase-type plasminogen activator (uPA-R) localizes uPA to the cell surface. The receptor-bound uPA converts plasminogen to the trypsin-like endopeptidase plasmin. Thus uPA is involved in the initiation of pericellular proteolysis. Pericellular proteolysis is assumed to facilitate the cellular infiltration into surrounding tissue. The uPA-R has recently been identified as a surface antigen of activated human T lymphocytes. We have characterized the uPA-R of the human CD4 T cell line Jurkat by immunological (flow cytometry), biochemical (ligand blotting), and physico-chemical (Scatchard blotting) methods. The collective data suggest that the human CD4+ T cell line Jurkat expresses a cell surface receptor for uPA similar to that of myelo/monocytes and normal T cells with regard to size, affinity, ligand specificity, and antigenicity. Binding studies using exogenous uPA and subsequent functional assays revealed that receptor-bound uPA retains its enzymatic activity. Saturation of the Jurkat cell uPA-R with exogenous uPA facilitated cellular invasion into fibrin matrices in vitro. uPA-dependent invasion was inhibited in the presence of an anti-catalytic monoclonal anti-uPA antibody. We propose that uPA-R-bound uPA may facilitate the invasiveness of uPA-R-positive T lymphocytes.

CD4-Positive T-Lymphocytes↗
PubMed1994

Cathepsin B activity in human lung tumor cell lines: ultrastructural localization, pH sensitivity, and inhibitor status at the cellular level.

We investigated the appearance and activity of the cysteine proteinase cathepsin B and its physiological inhibitors, stefins A and B, at the cellular level in human tumor cell lines HS-24, derived from a primary lung tumor (squamous cell), and SB-3, derived from a metastasis (lung adenocarcinoma). In addition to cathepsin B, these tumor cells also expressed the immunologically and functionally related cathepsin L, but not cathepsin H. Stefin A was found in HS-24 but not in SB-3 cells; stefin B was found in both cell types. Using a specific fluorogenic cytochemical assay, the intracellular activity of the enzyme was localized and quantified. Thus, the cellular cathepsin B kinetics for the synthetic substrates Z-Arg-Arg-4M beta NA and Z-Val-Lys-Lys-Arg-4M beta NA, its pH dependence and inhibition by E64, stefins A and B, and cystatin C could be determined. From these measurements it appeared that the enzyme exhibited different cleavage rates for these substrates in the different cell types, showed considerable cleavage activity at neutral pH, which was stable under these conditions for extended time periods, and was highly sensitive to the inhibitors E64 and cystatin C but was considerably less sensitive to stefins, particularly stefin A. By conventional light microscopy, confocal laser scanning microscopy, and electron microscopy the enzymatic activity was localized in lysosomes, as expected, but also in the endoplasmic reticulum, nuclear membrane, and plasma membrane. The endoplasmic reticulum is a site at which only pre-mature enzyme forms exist, which are usually not active. The appearance of enzymatic activity at the plasma membrane confirms earlier biochemical and immunofluorescence microscopic investigations. The different sites of localization within the cells make it likely that different forms of the enzyme are expressed simultaneously, which follow alternate ways of processing and sorting. Taken together, the results support an involvement of the enzyme under extracellular conditions in degradative processes.

Amino Acid Sequence↗
PubMed1994

[Maximal and high-velocity power. A study in Swiss male and female national ski athletes].

An important quality aspect of a good alpine skier is his ability to produce torque at high angular velocities. Both the isokinetic dynamometer (Cybex 6000, open chain of movement) and a device to measure flight time in skill jumps (Ergo Jump, closed chain of movement) allow to identify subjects with outstanding capacities in explosive force production and possibly to measure changes after specific training protocols aiming at improving this important characteristics of alpine skiers.

Adult↗
PubMed1993

The RNA polymerase I-specific transcription initiation factor UBF is associated with transcriptionally active and inactive ribosomal genes.

We have characterized an anti-NOR (nucleolar organizer region) serum (P419) from a patient with rheumatoid arthritis and show that it contains antibodies directed against the RNA polymerase I-specific transcription initiation factor UBF. This serum reacts with UBF from a variety of vertebrate cells as revealed both by immunoblotting and by indirect immunofluorescence. We have used the P419 serum to study the intracellular localization of this transcription factor at the light and electron microscopic level. In interphase cells, UBF exhibits a pronounced punctate pattern and is found to be associated with necklace-like structures, which appear to reflect the transcriptionally active state of the nucleolus. Inhibition of rRNA synthetic activity caused either by nutritional starvation or by actinomycin D treatment resulted in a marked decrease in the number and in a significant increase in the size of UBF-positive granules. Under all experimental conditions applied, UBF was exclusively found within the nucleolus and was not released into the nucleoplasm or cytoplasm. During mitosis, UBF was found to be concentrated at the chromosomal NOR indicating that a significant quantity, if not all, of this factor remains bound to the ribosomal transcription units. From this we conclude that UBF is associated both with transcriptionally active and inactive rRNA genes and, therefore, changes in the intracellular localization of UBF are very likely not involved in rDNA transcription regulation.

Animals↗
PubMed1993

[Religious dogmatism and ecclesiogenic neuroses. A quasi-experimental contribution to Catholic church communities between tradition and pleuralism].

Schaetzing (1955) characterizes "ecclesiogen neurosis" as mental disturbances, which are caused by "dogmatism of the church". To prove his thesis that the factor "dogmatism of the church" goes along with ecclesiogen-neurotic symptoms we use as factorial levels two different forms of Catholic congregations, that is to say a "traditional congregation" (high "dogmatism of the church") and a "pluralistic" one (low "dogmatism of the church"). In this quasi-experimental design 93 Catholics who are involved in the church of a "traditional" congregation and 70 of a "pluralistic" one are examined. The correctness of categorizing these congregations to the factorial levels is proved empirically. To record ecclesiogen-neurotic symptoms we consider "religious anxiety" (Kim, 1988) and "depressivity" (Zerssen, 1976). Our findings show that active Catholics of both congregations show a distinct higher expressivity in the dependent variable "depressivity" compared with the mean population. The comparison of both congregation samples by analysis of covariance shows furthermore, that the dependent variable "religious anxiety" is significantly higher in the "traditional" congregation than in the "pluralistic" one. The results are later critically discussed.

Adult↗
PubMed1992

Retinol stimulates Golgi apparatus activity in cultured bovine mammary gland epithelial cells.

Biochemical and electron microscopic studies have indicated that the Golgi apparatus responds to retinol. The purpose of this investigation was to visualize and record with living cells the rapidity of the response to retinol. A rapid response of the Golgi apparatus to retinol (1.75-17.5 mumol/L) added to the culture medium was observed using video-enhanced light microscopy with bovine mammary epithelial cells. The response was manifested within 1 min as a marked movement of membranes within the Golgi apparatus zone. In subsequent electron microscope preparations of the cells, only minor changes were observed and were restricted to increased numbers of normal-appearing membranes and vesicles associated with the trans Golgi apparatus face of the retinol-treated cells.

Animals↗
PubMed1991

[Sports in ankylosing spondylitis].

As therapy of ankylosing spondylarthritis still remains empirical, gymnastics and sports are of particular importance within the treatment of this disease. They aim at the improvement or at least the preservation of mobility, force and endurance. By those means an eventual immobilisation of the axial skeleton or the peripheral joints should take place in a position as favourable to function as possible. Various joint mobilisation techniques as well as muscle stretching are used to improve mobility. The latter thus pointedly prevents muscular disbalances. Various training methods are able to improve muscular performance. Slow dynamic force training can be used in gymnastic lessons as well as in home programmes. Maximal and staying power can thus be increased. Aerobic muscular training favours general efficiency, has a positive influence on risk factors of cardiac and vascular diseases and improves thoracic excursion. Motivation of the patient is correlated with the diversion of exercise, therapies and sport activities. The suitability of these measures are to be judged by expected maximal strain, the control of motion pattern, the effect of external forces as well as by the hazard to fall. Each and every sport activity has to be accompanied by supportive gymnastics. The most important sport disciplines are evaluated.

Gymnastics↗
PubMed1991

Faithful in vivo transcription termination of Xenopus laevis rDNA. Correlation of electron microscopic spread preparations with S1 transcript analysis.

DNA sequencing and subsequent functional in vitro analysis of the Xenopus laevis rDNA transcription termination has led to the identification of three transcription termination sequence elements: T1, located at the 3' end of the 28S rDNA; T2, a putative processing site 235 bp downstream of T1; T3, the principal terminator positioned 215 bp upstream of the gene promoter. As demonstrated for nuclear run-off assays, T3 was found to be the main terminator for Xenopus rDNA transcription. These in vitro data are in obvious contradiction to results obtained by electron microscopic (EM) spread preparations from rapidly isolated amplified oocyte nucleoli, i.e., an rDNA chromatin probe thought to represent the in vivo situation, indicative of transcription termination at sites T1-2. However, most interestingly, T3 had--again by the EM method--been identified as the exclusive terminator for NTS spacer transcription units. In order to answer the question of whether read-through transcription of the complete rDNA spacer sequence is obligatory for 40S pre-rRNA in vivo transcription, we analyzed several hundreds of spread rRNA genes from Xenopus oocyte nucleoli in great detail, applying two different spreading procedures, e.g., dispersal of amplified oocyte nucleoli shortly in detergent-free or detergent containing low-salt media prior to the EM spreading technique. Quantitation of EM spreads resulted in the finding that read-through rDNA spacer transcription beyond T1-2 termination sites (i.e., indicative of T3 transcription termination) can be visualized for the in vivo situation at a frequency of less than 3% of rRNA genes analyzed.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗