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Biomedical subjects

R Fritsch

Publications and source records attributed to R Fritsch.

At least 19 recordsLinked to original sources
PubMed1999

Organising multi-dimensional biological image information: the BioImage Database.

Nowadays it is possible to unravel complex information at all levels of cellular organization by obtaining multi-dimensional image information. At the macromolecular level, three-dimensional (3D) electron microscopy, together with other techniques, is able to reach resolutions at the nanometer or subnanometer level. The information is delivered in the form of 3D volumes containing samples of a given function, for example, the electron density distribution within a given macromolecule. The same situation happens at the cellular level with the new forms of light microscopy, particularly confocal microscopy, all of which produce biological 3D volume information. Furthermore, it is possible to record sequences of images over time (videos), as well as sequences of volumes, bringing key information on the dynamics of living biological systems. It is in this context that work on BioImage started two years ago, and that its first version is now presented here. In essence, BioImage is a database specifically designed to contain multi-dimensional images, perform queries and interactively work with the resulting multi-dimensional information on the World Wide Web, as well as accomplish the required cross-database links. Two sister home pages of BioImage can be accessed at http://www. bioimage.org and http://www-embl.bioimage.org

Bacterial Proteins↗
PubMed1998

Bet v 1, the major birch pollen allergen, and Mal d 1, the major apple allergen, cross-react at the level of allergen-specific T helper cells.

BACKGROUND: Food allergy to apple is frequent in individuals allergic to tree pollen. The major allergens of birch, Bet v 1, and apple, Mal d 1, have been cloned and sequenced and display a high degree of sequence identity, leading to IgE cross-reactivity. OBJECTIVE: We sought to investigate cross-reactivity between Bet v 1 and Mal d 1 at the level of allergen-specific T lymphocytes. METHODS: PBMCs of 13 patients allergic to birch pollen with oral allergy syndrome to apple were stimulated with rBet v 1 and rMal d 1, respectively, thereby establishing allergen-specific T-cell lines and T-cell clones. rMal d 1-specific T-cell cultures were tested for reactivity with rBet v 1, and rBet v 1-specific T cells were analyzed for reactivity with apple allergen. Cytokine production patterns in response to specific stimulation were evaluated. A selection of cross-reacting T-cell clones was mapped for epitope specificity by the use of overlapping Bet v 1- derived peptides. RESULTS: Nineteen Mal d 1-specific T-cell clones were produced, 79% of which cross-reacted with Bet v 1. Eight of 18 Bet v 1-specific T-cell clones cross-reacted with Mal d 1. Six peptides representing cross-reactive T-cell epitopes could be identified. The respective fragments from birch and apple displayed approximately 50% amino acid identity. Seventy percent of the cross-reactive T-cell clones revealed a T(H2)-like cytokine production pattern. CONCLUSION: The results indicate that cross-reactivity between apple and birch pollen leading to the clinical oral allergy syndrome occurs not only at the serologic, but also at the cellular level.

Adult↗
PubMed1998

Food allergy with monovalent sensitivity to poultry meat.

BACKGROUND: Allergy to poultry meat is only rarely covered in science. The few reports are usually related to patients allergic to eggs or bird feathers. OBJECTIVE: Two patients with a clear history of monovalent, ingestive allergy to chicken and turkey meat, without other food allergies, were analysed. The relevant allergens were to be identified by immunoblotting. METHODS: Both patients were evaluated with skin tests and specific IgE determination (CAP). Allergens were identified by SDS-PAGE and immunoblotting. Cross-reactivity of chicken and turkey meat was examined by IgE inhibition experiments. RESULTS: Skin tests and specific IgE were positive for chicken and turkey in both patients. Cross-reactivities to other poultry meats were documented for duck and goose meat. No sensitization to egg components or poultry feathers could be found. Allergenic proteins of poultry meat were detected at molecular weights of 21, 23 and 50 kDa (distinct bands) and 13, 27 and 33kDa (faint bands). An additional band at 91 kDa for turkey, can probably not be considered a distinct allergenic epitope. Immunoblot inhibition confirmed cross-reactivity of chicken and turkey meat allergens. CONCLUSION: Food allergy to poultry meat is a distinct disorder with crossreactivity among chicken, turkey and other poultries. The relevant allergens were identified by immunoblotting. Associated food allergy to egg-components is unlikely as the patients were able to tolerate egg and eggs products.

Adult↗
PubMed1998

Effects of adjuvants on the immune response to allergens in a murine model of allergen inhalation: cholera toxin induces a Th1-like response to Bet v 1, the major birch pollen allergen.

Based on the fact that type I allergies are frequently elicited by inhalant allergens, we have established a model of aerosol inhalation leading to allergic sensitization in BALB/c mice. Using this model we studied the effects of aluminium hydroxide (Al(OH)3), known to enhance IgE antibody responses, compared with cholera toxin (CT), a potent mucosal adjuvant, on the immune response to birch pollen (BP) and its major allergen Bet v 1. Two groups of BALB/c mice were either systemically immunized with recombinant Bet v 1 in Al(OH)3 and subsequently aerosol exposed to BP allergen, or aerosolized with BP and CT. IgE-mediated skin reactions were only elicited in the mice which had received Bet v 1/Al(OH)3. Allergen-specific serum IgE and IgG1 antibodies dominated in the Al(OH)3 group, IgG2a antibody levels to BP and rBet v 1 were markedly higher in the sera of mice exposed to CT with the allergen. IgA antibodies were only detected in the bronchial lavage of the CT-treated group. Moreover, the latter group displayed consistently higher T cell proliferative responses to BP and interferon-gamma production in vitro. Thus, the systemic immunization with rBet v 1 in Al(OH)3 before inhalation of the BP extract promoted a Th2-like immune response, while CT mixed with the aerosolized BP extract rather induced a Th1-like immune response. In an attempt to reverse these ongoing immune responses we could achieve a shift towards a Th0 response. Immunization with BP extract without adjuvant treatment led to undetectable antibody or cellular immune responses. We conclude from the present study that the induction of an immune response to BP allergen after aerosol inhalation can be directed towards a Th1- or a Th2-like response. Once established, the immune response can be modulated.

Adjuvants, Immunologic↗
PubMed1998

[Diagnostic validity of thermography of lameness in horses].

Thirty-six lameness free horses and 119 horses with lameness of the distal forelimb including the carpus were evaluated through thermography. Examination was done with an infrared thermography camera "Thermovision 470" and a specially developed analyzing software program. Temperature differences between corresponding regions of the left and right forelimb were determined and scrutinized statistically between various lameness groups. By creating temperature differences between both limbs a parameter for skin temperature was found which is independent of surrounding temperature. In lameness free horses skin temperature was contralaterally symmetric and there was no significant temperature difference between left and right limb. A significant (p < 0.01) temperature difference of all regions in comparison to lameness free horses was demonstrated in diseases like navicular disease, pododermatitis and tendopathia. Horses with a diagnosis of coffin bone fracture and arthropathia showed a significant (p < 0.05) temperature difference in almost all regions compared to controls, whereas horses with laminitis and periostitis did not show a significant difference. Loss of symmetric distribution of skin temperature could be demonstrated between affected and non-affected regions. Thermography can show and quantitatively prove very well changes in skin temperature in forelimb lameness. It must be emphasized that thermography in lameness diagnosis of horses is only useful in combination with a thorough clinical examination including additional examination procedures.

Animals↗
PubMed1997

Food allergy to pumpkinseed--characterization of allergens.

In recent years, pumpkinseed has become increasingly popular as a foodstuff. Here we report the occurrence of allergic reactions (itching and swelling of oral mucosa, and asthma) to this member of the Cucurbitaceae family. We investigated three patients suffering from symptoms after ingestion of roasted pumpkinseed. All the patients fished for sport and used pressed pumpkinseed flour as bait. Sera were tested by the immunoblot technique for IgE reactivity with proteins of pumpkinseed extract. The immunoblot revealed pumpkinseed allergens of 13, 14, 36, 48, 77, and 87 kDa. Inhibition experiments with recombinant birch profilin were performed: IgE binding to the 14-kDa allergen was completely blocked by preincubation of the sera with recombinant birch profilin. In conclusion, type I allergy to pumpkinseed is rare, and the patients' histories suggest inhalation of pumpkinseed flour during fishing to be the relevant route of sensitization, leading to food allergy to pumpkinseed.

Adult↗
PubMed1996

Checklist: vertebrate homeobox genes.

Up to now around 170 different homeobox genes have been cloned from vertebrate genomes. A compilation of the various isolates from mouse, chick, frog, fish and man is presented in the form of a concise checklist, including the designations from the original publications. Putative homologs from different species are aligned, and key characteristics of embryonic or adult expression domains, as well as mutant phenotypes are briefly indicated.

Animals↗
PubMed1996

IgE cross-reactivity between birch pollen, mugwort pollen and celery is due to at least three distinct cross-reacting allergens: immunoblot investigation of the birch-mugwort-celery syndrome.

BACKGROUND: Allergy to celery is often associated with sensitization to birch and/or mugwort pollen. OBJECTIVE AND METHODS: In a multi-centre study, sera from 23 patients suffering from type 1 allergy to celery and 15 patients with positive celery RAST but no clinical sensitization were compared. To examine whether cross-reactivity between celery and mugwort pollen includes cross-sensitization to birch pollen allergens, we determined cross-reacting structures in birch pollen, mugwort pollen and celery by means of immunoblotting. Inhibition studies were performed by preincubation of sera with extracts of birch pollen, mugwort pollen, and celery. RESULTS: We identified three groups of proteins--homologues of Bet v 1 and birch profilin (Bet v 2) as well as a group of proteins with a molecular range of 46 to 60 kD--displaying IgE-cross-reactivity, which were shared by birch pollen and celery. Two of these groups of allergens (profilin and the 46 to 60 kD proteins) were also present in mugwort pollen. In this paper we demonstrate that most cross-reacting allergens present in mugwort pollen and celery can also be detected in birch pollen extract. CONCLUSION: Therefore we propose, from a serological point of view, to extend the mugwort-celery syndrome to the birch-mugwort-celery syndrome.

Allergens↗
PubMed1996

Forebrain patterning defects in Small eye mutant mice.

Pax6 is a member of the Pax gene family of transcriptional regulators that exhibits a restricted spatiotemporal expression in the developing central nervous system, eye and nose. Mutations in Pax6 are responsible for inherited malformations in man, rat and mouse. To evaluate the role of Pax6 in forebrain development, we studied in detail mouse Small eye/Pax6 mutant brains. This analysis revealed severe defects in forebrain regions where Pax6 is specifically expressed. The establishment of some expression boundaries along the dorsoventral axis of the secondary prosencephalon is distorted and the specification of several ventral structures and nuclei is abolished. Specifically, the development of the hypothalamo-telencephalic transition zone and the ventral thalamus is distorted. Our detailed analysis included a comparison of the expression of Pax6, Dlx1 and several other genes during embryonic mouse brain development in wild-type and in the mutant Small eye (Sey) brain. The results from the analysis of normal brain development show that the restricted expression of Pax6 and Dlx1 at E12.5 dpc respect domains within the forebrain, consistent with the implications of the prosomeric model for the organisation of the forebrain (L. Puelles and J. L. R. Rubenstein (1993) Trends Neurosci. 16, 472-479). Furthermore, we found an early restriction of Pax6 and Dlx1 expression into presumptive histogenetic fields that correlate with the formation of distinct forebrain structures and nuclei. Our results are discussed in light of changes in adhesive properties in the Sey brain that might control segregation, assembly and cell migration of progenitors of specific forebrain regions.

Animals↗
PubMed1994

The role of Pax-1 in axial skeleton development.

Previous studies have identified a single amino-acid substitution in the transcriptional regulator Pax-1 as the cause of the mouse skeletal mutant undulated (un). To evaluate the role of Pax-1 in the formation of the axial skeleton we have studied Pax-1 protein expression in early sclerotome cells and during subsequent embryonic development, and we have characterized the phenotype of three different Pax-1 mouse mutants, un, undulated-extensive (unex) and Undulated short-tail (Uns). In the Uns mutation the whole Pax-1 locus is deleted, resulting in the complete absence of Pax-1 protein in these mice. The other two genotypes are interpreted as hypomorphs. We conclude that Pax-1 is necessary for normal vertebral column formation along the entire axis, although the severity of the phenotype is strongest in the lumbar region and the tail. Pax-1-deficient mice lack vertebral bodies and intervertebral discs. The proximal part of the ribs and the rib homologues are also missing or severely malformed, whereas neural arches are nearly normal. Pax-1 is thus required for the development of the ventral parts of vertebrae. Embryonic analyses reveal that although sclerotomes are formed in mutant embryos, abnormalities can be detected from day 10.5 p.c. onwards. The phenotypic analyses also suggest that the notochord still influences vertebral body formation some days after the sclerotomes are formed. Furthermore, the notochord diameter is larger in mutant embryos from day 12 p.c., due to increased cell proliferation. In the strongly affected genotypes the notochord persists as a rod-like structure and the nucleus pulposus is never properly formed. Since the notochord is Pax-1-negative these findings suggest a bidirectional interaction between notochord and paraxial mesoderm. The availability of these Pax-1 mutant alleles permitted us to define an early role for Pax-1 in sclerotome patterning as well as a late role in intervertebral disc development. Our observations suggest that Pax-1 function is required for essential steps in ventral sclerotome differentiation, i.e. for the transition from the mesenchymal stage to the onset of chondrogenesis.

Animals↗
PubMed1993

[Indications for ultrasonography in the diagnosis of surgical diseases].

Ultrasonography has established itself as an invaluable diagnostic aid in surgical diseases. In addition to the diagnosis of thoracic and abdominal disease, ultrasonography is increasing in importance in the examination of muscles, tendons and joints in small animals. In the horse, the application of the technique is being extended from tendon conditions to organ diseases. The optimal diagnostic information can only be achieved through the use of different scanner types.

Abdomen↗
PubMed1993

[Ulna growth retardation syndrome in the dog].

Premature closure of the distal ulnar physis leads to medial bowing of the radius, later to lateral deviation of the carpus, and ventral subluxation of the elbow. Diagnosis of this growth disturbance depends on accurate radiographical examination. There are different surgical treatments to allow the radius to grow without impediment. The prognosis depends on early treatment.

Animals↗
PubMed1991

The molecular basis of the undulated/Pax-1 mutation.

The murine paired box gene Pax-1 has been associated with the mouse developmental mutant undulated (un), which exhibits malformations in the vertebral column. In un mice, a point mutation leading to a Gly-Ser exchange in a conserved part of the paired domain of Pax-1 is present. Here we show that Pax-1 encodes a DNA-binding protein with transcriptional activating properties. The DNA-binding specificity of the Pax-1 protein has been extensively analyzed in gel shift assays, and in conjunction with binding interference experiments, a DNA-binding core motif was defined. Comparison of the DNA-binding properties of wild-type and un Pax-1 proteins demonstrates that the Gly-Ser replacement at position 15 within the paired domain dramatically decreases the DNA-binding affinity of the un Pax-1 protein and alters its DNA-binding specificity. These results decipher the molecular basis of the un mutation.

Alkylation↗
PubMed1991

Does trampolining and anaerobic physical fitness affect sleep?

The structure of nocturnal sleep of 16 volunteers, participating in the anaerobic sports of trampolining, dancing, and soccer, was monitored by means of polygraphic recordings. Since trampolining requires the acquisition of unfamiliar patterns of motor coordination, it can be considered as a special form of motor learning, whereas the acquisition of motor skills specific for dancing and soccer can be linked with motor patterns of normal biped locomotion. According to this view, an experimental group of 8 volunteers was formed; they participated in a training course of trampolining. In addition, a control group of 8 subjects was recruited, who engaged in one of the other two anaerobic sports. Subjects who had acquired new motor skills during a 13-wk. program in trampolining showed a statistically significant increase in REM-sleep. By contrast, the 8 subjects of the control group showed no considerable changes in REM-sleep. This suggests that efforts in acquiring new and complex motor patterns activate processes specifically involved in the generation of REM stage during nocturnal sleep.

Adult↗
PubMed1989

Rapid detection of IDDM susceptibility with HLA-DQ beta-alleles as markers.

The allelic forms of the human leukocyte antigen (HLA)-DQ beta-chain (DQB1) have been recognized as the best markers of insulin-dependent diabetes mellitus (IDDM) susceptibility. We describe a method that allows the recognition of these DQB1 alleles without the use of either allele-specific oligonucleotide probes or radioactive material. This method determines these alleles by electrophoretically separating restriction enzyme-generated fragments from the polymerase chain-reaction-amplified second exon of the HLA-DQB1 gene, which encodes the first domain of the protein chain. This digestion method, which is simpler and more rapid than the previously adopted hybridization method, is described in detail to enable individuals at any clinical laboratory to quickly ascertain IDDM susceptibility.

Alleles↗