[A case of spinal elastofibroma].
Explore the source record for details and available documents.
Diagnosis, Differential↗
Biomedical subjects
P Köhler
Publications and source records attributed to P Köhler.
[Experiences with a clinical cancer registry for radiotherapy].
BACKGROUND: A clinical cancer registry is required to assure result quality in radiation oncology. A simpler system could help small radiotherapy departments to survey their therapy results, as long as there is no connection to a central institution established. METHODS: Our clinical cancer registry RADOC was designed for easy handling on a single working place with standard Windows PC. RESULTS: Without additional costs, we store about 550 treatment courses each year and follow-up data. Several times a year the program provides basic analysis of these data for our internal quality assurance. As an example, the results on breast cancer are shown. CONCLUSIONS: Our department's internal therapy registry enables us to survey continuously important therapy results without additional costs, and thereby adds to our quality assurance process. On the other hand, only a centralized registry can provide complete data.
Documentation↗
The biochemical basis of anthelmintic action and resistance.
The most commonly used modern anthelmintics include the benzimidazoles, the nicotinic agonists. praziquantel, triclabendazole and the macrocyclic lactones. These drugs interfere with target sites that are either unique to the parasite or differ in their structural features from those of the homologous counterpart present in the vertebrate host. The benzimidazoles exert their effect by binding selectively and with high affinity to the beta-subunit of helminth microtubule protein. The target site of the nicotinic agonists (e.g. levamisole, tetrahydropyrimidines) is a pharmacologically distinct nicotinic acetylcholine receptor channel in nematodes. The macrocyclic lactones (e.g. ivermectin, moxidectin) act as agonists of a family of invertebrate-specific inhibitory chloride channels that are activated by glutamic acid. The primary mode of action of other important anthelmintics (e.g. praziquantel, triclabendazole) is unknown. Anthelmintic resistance is wide-spread and a serious threat to effective control of helminth infections, especially in the veterinary area. The biochemical and genetic mechanisms underlying anthelmintic resistance are not well understood, but appear to be complex and vary among different helminth species and even isolates. The major mechanisms helminths use to acquire drug resistance appear to be through receptor loss or decrease of the target site affinity for the drug. Knowledge on the mechanisms of drug action and resistance may be exploitable for the development of new drugs and may provide information on ways to overcome parasite resistance, respectively.
Animals↗
[The effects of psychodynamic inpatient treatments on personality data of patients with anorexia nervosa and bulimia nervosa - results of the German multicenter study (TR-EAT)].
OBJECTIVES: How are the effects of a psychodynamic inpatient treatment on personality data of patients with anorexia nervosa and bulimia nervosa? In how many patients can a successful change in the personality area be observed? METHODS: 732 patients were assessed at the beginning and the end of an inpatient treatment as well as 2 1/2 years after this treatment. Data were collected by means of the personality inventories "Freiburger Persoenlichkeitsinventar (FPI-R)" and "Narzissmusinventar". A definition of success was constructed using the clinical significance concept. It is related to the scales life satisfaction, inhibition (FPI-R), powerless self and negative body self (Narzissmusinventar). RESULTS: The results in both questionnaires show the clinically well known psychopathology characteristics of eating disorder patients. During the inpatient treatment and also afterwards, there are improvements in the personality data, but not to the extent of the values obtained from a healthy control group. In the outcome measure, one third of the patients experienced remarkable improvements. The success in the personality area is positively correlated to the success in the eating disorder symptoms. This success could not be predicted by initial data or by therapy data. CONCLUSIONS: There are marked impairments of the patients in the personality data. Changes in this domain take time and are rather small.
Adult↗
On a new artificial mediator accepting NADP(H) oxidoreductase from Clostridium thermoaceticum.
The purification and partial characterisation of an NADP(H) dependent artificial mediator accepting pyridine nucleotide oxidoreductase (AMAPOR) from the anaerobic Clostridium thermoaceticum is described. Depending on the redox potential of the artificial mediators the AMAPOR is able to regenerate NADP+ or NADPH rendering the enzyme useful for preparative work applying NADP(H) dependent oxidoreductases. At 37 degrees C crude extracts of C. thermoaceticum have an AMAPOR activity of 5-7 U mg(-1). This is 28 degrees under the optimal growth temperature of this microrganism. Out of apparently more than 10 AMAPOR active proteins in the crude cell extracts visible after electrophoresis and activity staining on the gel, two of these proteins were isolated. They seem to be two different oligomers. According to gel electrophoresis they show apparent molecular masses of about 200 and 400 kDa. These two forms showed after SDS gel electrophoresis two monomers with apparent molecular masses of 42 and 56 kDa which we call alpha and beta. The two oligomers may have the compositions alpha2beta2 and alpha4beta4. They contain Fe/S cluster and FAD. Various amounts of the FAD were lost during the purification procedure. This loss is partially reversible after addition of FAD. The AMAPOR reacts with rather different artificial mediators such as viologens, quinones e.g. 1,4-benzoquinone or anthraquinone-2,6-disulphonate, 2,6-dichloro-indophenol and clostridial rubredoxin. Two different ferredoxins from C. thermoaceticum, oxygen or lipoamide are no substrates indicating the here described AMAPOR is not a diaphorase in the usual sense.
Amino Acid Sequence↗
[Biker's nodule"--perineal nodular induration of the cyclist].
The "biker's nodule" is a rarely appearing perineal nodular induration of the cyclist. Repeated microtrauma to the subcutaneous fatty tissue or collageneous tissue, caused by pressure or vibration which the bicycle's saddle exerts on the perineal region, leads to collagenous degeneration, myxoid alteration and pseudocyst formation. Because of the painful subcutaneous nodules the patient is often forced to reduce or even give up his training. Therapy of the "biker's nodule" consists in avoiding the pathogenetic factors, i.e. giving up training for a temporary period of time and reducing pressure on the perineal region. Intralesional injection of either hyaluronidase or corticosteroids may also be helpful.
Adipose Tissue↗
Glycosylation and palmitoylation are common modifications of giardia variant surface proteins.
Explore the source record for details and available documents.
Animals↗
Stage-specific expression and targeting of cyst wall protein-green fluorescent protein chimeras in Giardia.
In preparation for being shed into the environment as infectious cysts, trophozoites of Giardia spp. synthesize and deposit large amounts of extracellular matrix into a resistant extracellular cyst wall. Functional aspects of this developmentally regulated process were investigated by expressing a series of chimeric cyst wall protein 1 (CWP1)-green fluorescent protein (GFP) reporter proteins. It was demonstrated that a short 110 bp 5' flanking region of the CWP1 gene harbors all necessary cis-DNA elements for strictly encystation-specific expression of a reporter during in vitro encystation, whereas sequences in the 3' flanking region are involved in modulation of steady-state levels of its mRNA during encystation. Encysting Giardia expressing CWP1-GFP chimeras showed formation and maturation of labeled dense granule-like vesicles and subsequent incorporation of GFP-tagged protein into the cyst wall, dependent on which domains of CWP1 were included. The N-terminal domain of CWP1 was required for targeting GFP to regulated compartments of the secretory apparatus, whereas a central domain containing leucine-rich repeats mediated association of the chimera with the extracellular cyst wall. We show that analysis of protein transport using GFP-tagged molecules is feasible in an anaerobic organism and provides a useful tool for investigating the organization of primitive eukaryotic vesicular transport.
3' Untranslated Regions↗
Purification and characterization of recombinant pyruvate phosphate dikinase from Giardia.
The gene encoding pyruvate phosphate dikinase (PPDK) from Giardia duodenalis was expressed using a baculovirus system. The recombinant enzyme was purified to homogeneity and its enzymological and solution structure properties characterized. The catalytic constant for the pyruvate-producing reaction was about twice as high (1560 min(-1) at 30 degrees C) as that for the reverse reaction (700 min(-1)) and the k(cat)/Km for PPi was about two orders of magnitude higher than k(cat)/Km for Pi, indicating that the pyruvate-forming reaction is much more efficient than the reverse, phosphoenolpyruvate (PEP)-forming process. The endogenous substrate levels found for PEP (0.5 mM) and pyruvate (< 80 microM) support the assumption that, under physiological conditions, the enzyme primarily performs a catabolic function. The molecular mass of the purified recombinant PPDK was analyzed by analytical ultracentrifugation and size exclusion chromatography using different assay conditions that have been reported to affect the quaternary structure of PPDKs in other organisms. Both methods clearly indicated a dimeric structure for giardial PPDK with a molecular mass of about 197 kDa (monomer mass 97.6 kDa). Several compounds, primarily structural analogs of PPi, were tested for their ability to inhibit PPDK activity. Most of the bisphosphonates examined showed either no, or only a moderate, inhibitory effect on the enzyme. Imidodiphosphate was the only competitive inhibitor with respect to PPi (Kic = 0.55 mM), whereas the bisphosphonates produced a mixed type of inhibition. The most active compound in inhibiting PPDK activity was oxalate, with a Kic value of less than 1 microM with respect to PEP.
Animals↗
Study of the effect of DATEM. 1. Influence of fatty acid chain length on rheology and baking.
To answer the question of which fatty acid residue is the most effective, diacetyltartaric esters of monoglycerides (DATEMs) with fatty acids of chain lengths 6:0-20:0 were synthesized. The activity of synthesized DATEMs and commercial DATEM products was studied by means of rheological methods and a microscale baking test with 10 g of flour. Variation of the acyl residue from 6:0 to 22:0 showed that stearic acid (18:0) had the best effect on the baking activity of DATEM (loaf volume increased by 62%). DATEMs containing unsaturated fatty acids (18:1, 18:2) or DATEMs produced from diacylglycerols instead of monoacylglycerols showed a slight increase of the loaf volumes. A slight effect of DATEM on the rheology of dough was observed. However, much greater was the effect on the gluten isolated from doughs prepared with DATEM. The resistance of gluten to extension was increased after the addition of increasing amounts of DATEM (0.1-0.5%). Within the series of DATEMs derived from the homologous series of monoacylglycerols the product based on glycerol monostearate (18:0) showed a maximum increase of the gluten resistance.
Cooking↗
[Ganglioglioma of the cerebellum on the CT].
Explore the source record for details and available documents.
Adult↗
Mutational analysis of the nucleoid-associated protein HBsu of Bacillus subtilis.
The essential nucleoid-associated protein HBsu of Bacillus subtilis comprises 92 residues, 20% of which are basic amino acids. To investigate the role of the residues located within the DNA-binding arm, the arginine residues R58 and R61 were changed to leucine, while lysine residues K80 and K86 were replaced by alanine. All altered proteins exhibited a reduction in DNA binding capacity, ranging from 10% to 30% of HBsu wild type DNA-binding ability. To investigate the physiological effect of these mutations in B. subtilis, the indigenous hbs gene was replaced by the mutated genes. B. subtilis strain PK20, which carries the HBsu mutation R58L which exhibits the lowest DNA binding ability in vitro, showed the strongest retardation of growth compared to the wild type. Furthermore, PK20 cells displayed an increased rate of cell lysis, diminished sporulation efficiency and a reduced level of negatively supercoiled DNA. These observations suggest that the DNA binding ability of HBsu DNA is important for growth and differentiation and influences DNA topology.
Amino Acid Sequence↗
The complete amino acid sequence of a trypsin inhibitor from Bauhinia variegata var. candida seeds.
Trypsin inhibitors of two varieties of Bauhinia variegata seeds have been isolated and characterized. Bauhinia variegata candida trypsin inhibitor (BvcTI) and B. variegata lilac trypsin inhibitor (BvlTI) are proteins with Mr of about 20,000 without free sulfhydryl groups. Amino acid analysis shows a high content of aspartic acid, glutamic acid, serine, and glycine, and a low content of histidine, tyrosine, methionine, and lysine in both inhibitors. Isoelectric focusing for both varieties detected three isoforms (pI 4.85, 5.00, and 5.15), which were resolved by HPLC procedure. The trypsin inhibitors show Ki values of 6.9 and 1.2 nM for BvcTI and BvlTI, respectively. The N-terminal sequences of the three trypsin inhibitor isoforms from both varieties of Bauhinia variegata and the complete amino acid sequence of B. variegata var. candida L. trypsin inhibitor isoform 3 (BvcTI-3) are presented. The sequences have been determined by automated Edman degradation of the reduced and carboxymethylated proteins of the peptides resulting from Staphylococcus aureus protease and trypsin digestion. BvcTI-3 is composed of 167 residues and has a calculated molecular mass of 18,529. Homology studies with other trypsin inhibitors show that BvcTI-3 belongs to the Kunitz family. The putative active site encompasses Arg (63)-Ile (64).
Amino Acid Sequence↗
The variant-specific surface protein of Giardia, VSP4A1, is a glycosylated and palmitoylated protein.
The variant-specific surface proteins (VSPs) of the ancient protist Giardia duodenalis (syn.: Giardia intestinalis, Giardia lamblia) are cysteine- and threonine-rich polypeptides that can vary considerably in sequence and size. In the present study, we have purified a VSP (VSP4A1, formerly called CR1SP-90) from a cloned Giardia isolate, derived from a sheep, by Triton X-114 phase partitioning and anion-exchange chromatography. Analysis of the purified VSP4A1 showed that this protein is posttranslationally modified with both glycans and lipid. The glycans of VSP4A1 were detected and partially characterized by (1) compositional analysis, which indicated the presence of GlcNAc and Glc (0.5 and 1.0 mol/mol of protein respectively), and (2) the specific labelling of VSP4A1 with galactosyltransferase/UDP-[3H]Gal. The glycans were released by beta-elimination, suggesting that they are O-linked to the protein. Bio-Gel P4 chromatography of the released galactosylated glycans and further compositional analysis suggested that the major glycan on the VSP is a trisaccharide with Glc at the reducing terminus. These and other results indicate the absence of any N-linked glycans on the VSP and suggest instead that it is elaborated with a novel type of short O-linked glycan. Compositional analysis and radiolabelling experiments also indicated that VSP4A1 is modified with covalently linked palmitate (1 mol/mol of protein). Hydroxylamine treatment at neutral pH of[3H]palmitate-labelled VSP4A1 indicated that the acyl chain may be attached by a thioester linkage. A likely location for the lipid modification appears to be in the region of the C-terminal domain where it may facilitate association of the protein with the plasma membrane.
Animals↗
Primary structure and biochemical properties of a variant-specific surface protein of Giardia.
Trophozoites of Giardia duodenalis express at their cell surface variant-specific proteins (VSPs) that are believed to contribute to the protection of the parasite from immunological and other host defense mechanisms. In the present study, we have cloned and characterized the gene encoding a VSP (VSP4A1, originally designated CRISP-90) that is expressed by the sheep-derived Giardia variant clone O2-4A1. The gene was isolated by probing a genomic library with a near-full-length gene-specific polymerase chain reaction (PCR) product. The VSP4A1 gene specifies a 70729 Da protein with features common to all previously reported VSPs, including a high cysteine and threonine content, a highly conserved hydrophobic carboxy-terminal domain and little similarity in the remaining polypeptide sequence. Comparison of the predicted sequence with the amino-terminal sequence of purified VSP4A1 revealed the absence of an amino-terminal hydrophobic extension from the mature protein. VSP4A1 purified from the O2-4A1 variant clone was found to undergo conformational changes resulting in the formation of two additional electrophoretic species. Free thiol groups were not detected in purified VSP4A1, indicating that all cysteine residues may be involved in disulphide crosslinking. Possibly as a consequence of this VSP4A1 was found to be fairly resistant to proteolytic digestion. Although VSP4A1 is able to bind zinc following blotting to a nitrocellulose membrane, other analyses with both the purified and cell associated VSP have failed to confirm significant zinc ion binding to this protein. The latter result questions the assumption previously made by other authors that zinc binding to VSPs constitutes an important structural and functional aspect of these proteins.
Amino Acid Sequence↗
Association of the histone-like protein HBsu with the nucleoid of Bacillus subtilis.
To investigate the physiological role of the essential histone-like protein of Bacillus subtilis (HBsu) in the nucleoid structure, a fusion to the green fluorescent protein (GFP) of Aequorea victoria was constructed. This purified fusion protein, HBsuGFP, showed a threefold-reduced affinity to DNA compared to unmodified HBsu; however, in gel mobility shift experiments HBsuGFP DNA-binding was greatly enhanced in the presence of low HBsu concentrations. Additional production of HBsu also had a positive effect on the retarded growth of a B. subtilis strain, PK9C8, which expresses only hbs-gfp (encoding HBsuGFP). HBsu seemed to influence not only growth but also nucleoid structure, as monitored by DNA staining and fluorescence microscopy. Without HBsu production, strain PK9C8 showed a relaxed nucleoid structure associated with HBsuGFP. However, a highly compact nucleoid structure that coincides with the fluorescence of the fusion protein was visualized when HBsu synthesis was induced. This provides the first evidence for in vivo association of HBsu in DNA packaging and its consequence on cell growth.
Bacillus subtilis↗
The release of the variant surface protein of Giardia to its soluble isoform is mediated by the selective cleavage of the conserved carboxy-terminal domain.
The trophozoites of Giardia duodenalis are covered by a coat composed of an apparently single species of a group of novel, cysteine-rich proteins. These variant-specific surface proteins (VSPs) can be changed by sequential expression of different VSP genes, a process for which a gradual exchange of VSP molecules appears to be required. In the present study, we have examined the in vitro release of one of these VSPs (VSP4A1, formerly named CRISP-90) expressed by a sheep-derived variant Giardia clone. During in vitro incubation of the cloned trophozoites, the membrane-associated form of VSP4A1 (mVSP4A1) was specifically converted to a water-soluble isoform that was continuously released into the culture medium. The time required for mVSP4A1 to decline to half of the initial amount was 7.8 h. Analysis of the two purified protein species by mass spectrometry revealed molecular mass values of 68,991 Da for mVSP4A1 and of 65,425 Da for its soluble counterpart. Amino-terminal sequencing and metabolic labeling experiments indicated that the release of mVSP4A1 was associated with the cleavage of a carboxy-terminal peptide carrying the palmitic acid recently demonstrated to be attached to mVSP4A1. Calculations using the molecular mass and predicted amino acid sequence data indicated that fragmentation of the protein possibly occurs at a site located between the lysine and serine residues of the highly conserved NKSGLS motif directly preceding the hydrophobic sequence previously postulated to serve as a membrane anchoring domain of other VSP molecules. The observed processing of the membrane-associated VSP to its soluble isoform is assumed to be an essential requirement for the ability of the parasite to undergo surface antigenic variation and thus for its establishment and survival within the vertebrate host.
Amino Acid Sequence↗
Comparison of genetic groups determined by molecular and immunological analyses of Giardia isolated from animals and humans in Switzerland and Australia.
Nine axenic isolates of Giardia originating from four different host species in Switzerland were subjected to genetic analysis using the polymerase chain reaction (PCR) to amplify segments of genes encoding different trophozoite variant surface proteins (VSPs). Three genotypes were identified on the basis of product yield, size, and restriction-fragment-length polymorphisms (RFLPs). Five G. duodenalis isolates (O1, B1, B2, B3-1A1 and C1--from a sheep, three calves and a dog, respectively) were classified as belonging to genetic group I of Andrews et al. (1989). DNA amplified from the VSP genes tsp11, tsa417 and vsp1267 of these isolates was indistinguishable in size and restriction characteristics from that amplified from group-I Giardia isolated from humans in Australia. One human-derived Swiss isolate (H2-17A1), typed as belonging to genetic group II, yielded a vsp1267-specific PCR product that was indistinguishable by size or restriction sites from the equivalent 1.6-kb product amplified from human-derived Australian group-II organisms. This isolate also yielded 1.8-kb tsp11 and 0.52-kb tsa417/tsp11-like PCR products possessing RFLPs typical of group-II organisms. Three isolates (O2-4A1, O3 and H3-15K2--originating from two sheep and a human, respectively) represent a novel genotype that is closely related to genetic groups I and II. These three isolates exhibited identical RFLPs in their tsp11 PCR products and failed to yield a vsp1267 PCR product. An antiserum specific for the 90-kDa VSP of the sheep-derived clone O2-4A1 reacted strongly by immunofluorescence and on Western blots with surface proteins from the O2, O3 and H3 isolates only--consistent with the genetic classification determined above. The data provide no evidence for the occurrence of host-specific genotypes.
Animals↗