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M Hinz

Publications and source records attributed to M Hinz.

At least 37 records · Page 2Linked to original sources
PubMed1999

Structure of the Xenopus laevis TFF-gene xP4.1, differentially expressed to its duplicated homolog xP4.2.

TFF-peptides (formerly P-domain peptides, trefoil factors) represent major secretory products of mucous epithelia in mammals and amphibia. The nucleotide sequence of a large portion of a gene encoding the TFF-peptide xP4.1 from Xenopus laevis and its genomic organization were determined in the present study. The peptide xP4.1 containing four TFF-domains is thought to represent the functional frog homolog of human TFF2 (formerly hSP). The xP4.1 gene analyzed spans a region of about 7 kb and consists of six exons. Each TFF-domain is encoded by a single exon flanked by type 1 introns typical of shuffled modules. The 5'-upstream region contains a TATA-box, and potential binding sites for hepatocyte nuclear factor 3 and AP-1. Furthermore, the cDNA sequence of a transcript named xP4.2 with 91% similarity to xP4.1 is presented. RT-PCR analysis revealed that xP4.1 and xP4.2 genes are differentially expressed. xP4.1 transcripts are detectable only in the stomach, but not in the esophagus, whereas xP4.2 transcripts are found both in the esophagus and in the stomach with a descending gradient from fundus to antrum.

Amino Acid Sequence↗
PubMed1999

Secretion of TFF-peptides by human salivary glands.

TFF-peptides (formerly P-domain peptides, trefoil factors) are typical secretory products of mucin-producing cells and seem to influence the rheological properties of mucous gels. Here, localization studies of TFF-peptides in human salivary glands are presented. Expression studies (polymerase chain reaction) revealed mainly TFF3 transcripts in submandibular and sublingual glands and trace amounts in parotid glands. Only low levels of expression of TFF1 could be monitored in submandibular and sublingual glands, and TFF2 transcripts were hardly detectable in all three major salivary glands. This result was partly confirmed by Western blot analysis, which only detected TFF3 in submandibular glands, but not in sublingual and parotid glands. TFF3 was also shown to be a constituent of human saliva. Immunofluorescence localized TFF3 solely in the secretory granules of serous cells of submandibular glands but not in mucous cells. This localization is remarkably similar to that of the unique low-molecular-weight mucin MUC7, which interacts with a number of oral microorganisms.

Blotting, Western↗
PubMed1999

The influence of antibody and complement removal with a Ig-Therasorb column in a xenogeneic working heart model.

OBJECTIVE: Organ transplantation is limited by the number of brain-dead human donors. Xenotransplantation could be an alternative to guarantee a constant supply of organs. A major problem of xenotransplantation are xenogeneic natural antibodies (XNAb) directed against species-specific antigens of a discordant donor species (e.g. pig). They trigger the hyperacute xenograft rejection (HXR). Re-usable immunoapheresis (LA)-columns Ig-Therasorb (Therasorb, Baxter) were used to adsorb these XNAb. The effect of immunoapheresis of the perfusing human blood was investigated in ex vivo working pig hearts. METHODS: Hearts of 12 landrace pigs (body weight 14-31 kg) were explanted after inducing cardiac arrest with 4 degrees C Celsior solution. Human blood (500 ml, heparinized) was obtained from healthy volunteers. In group 1 (G1, n = 6), blood as perfusate remained untreated. In group 2 (G2, n = 6), native blood was separated by plasmapheresis into cellular components and plasma. The latter passed through the Ig-Therasorb column for removal of immunoglobulins (so-called immunoadsorption or immunoapheresis). After back-table preparation the hearts were mounted to the working heart model. After 20 min of reperfusion in Langendorff mode, the working heart mode was established. Blood samples were taken isochronously for measurement of: CK(-MB), LDH, ASAT, troponin, immunoglobulins, complement activity, anti-pig antibodies and others. After cessation of the heart, atrial and ventricular tissue samples were taken for histological examinations (light/electron microscopy and immunohistochemistry). RESULTS: Two cycles of immunoapheresis reduced the levels of IgG by 84%, IgM by 83.3% and IgA by 76%. In G2, the antibody immunoadsorption of blood prolonged the duration of the working heart mode significantly to 335+/-37.5 min. In contrast, hearts of group 1 (control) failed after 125+/-31.3 min. Heart rate was significantly different between both groups (G1, 77.3+/-6.1 beats/min; G2, 86.5+/-5.5 beats/min). In G2 cardiac output was 118% and mean coronary flow was 154.6% higher than in G1. CK, LDH and ASAT showed no differences in the two groups. Heart weight increased significantly more in group 1 than in G2. Histological examination indicated specific signs of HXR in G1 after 1.5 h, whereas in G2 only slight unspecific damages were found after 6 h. CONCLUSION: Antibody removal by means of immunoapheresis results in a significantly improved xenogeneic cardiac function. Immunoapheresis may, therefore, become an important adjunct in future pig-to-man clinical xenotransplantation.

Animals↗
PubMed1999

Effects of prolonged cold storage time in xenotransplantation.

BACKGROUND: Ischemia and reperfusion injury after prolonged ischemic time (IT) has a marked influence on hyperacute xenograft rejection (HXR). The aim of the study was to investigate the impact of different cold ischemic times on the HXR of ex vivo "working pig hearts" perfused with human blood. Xenoreactive natural antibodies (XNAb) as the trigger of HXR were reduced by immunoadsorption (IA) using an Ig-Therasorb column. METHODS: Hearts of 24 Landrace pigs (13-31 kg) were harvested after cardioplegia with Celsior-solution and split into 4 groups. In Group C1 (n = 6) the short ischemic time (IT) lasted 48.9+/-10 minutes on the average prior to start of xenoperfusion, in Group I1 IT lasted 4 hours instead. Groups C2 and 12 experienced the same IT as C1 and I1, respectively, but underwent 2 cycles of IA in addition. IA removed immunoglobulins IgG, IgM and IgA from the perfusate. In the working heart mode hemodynamic parameters were measured in defined intervals. Blood samples were collected at the same time to determine myocardial enzymes, immunoglobulins, complement and anti-pig-antibodies. At the end of the study (cardiac arrest) tissue was sampled for histologic examination (light/electron microscopy (LM/EM) and immunohistochemistry). RESULTS: Survival time of the control Group C1 was 125 minutes. IA resulted in an extension of perfusion time to 6.5 hours in C2. Four hours of IT (I1) prolonged the working time of hearts when compared with C1. IA had no additional impact (I2). Heart weight increased significantly in C1 without IA. Cardiac output and coronary flow in C1 were significantly lower when compared with the other 3 groups. IA improved cardiac output (CO) in C2 (vs C1, p < 0.001). Histologic signs of HXR (LM/EM) could be found in C1 in contrast to the other groups. Serologic parameters for myocardial damage were higher in groups with prolonged IT than in groups with short IT. CONCLUSION: Prolonged ischemia and reperfusion injury showed controversial effects in this specific xenogeneic heart transplant model. In contrast to observations in allogeneic transplantation 4 hours of IT showed a beneficial behaviour of the xenografts. Reasons could be either a protective effect of the Celsior solution or changes of the endothelial cell surface (in terms of glycosylation or loss of alpha1-3Gal-epitopes). Tolerance of prolonged IT would allow transportation of xenografts over long distances.

Animals↗
PubMed1999

NF-kappaB function in growth control: regulation of cyclin D1 expression and G0/G1-to-S-phase transition.

Nuclear factor kappa B (NF-kappaB) has been implicated in the regulation of cell proliferation, transformation, and tumor development. We provide evidence for a direct link between NF-kappaB activity and cell cycle regulation. NF-kappaB was found to stimulate transcription of cyclin D1, a key regulator of G1 checkpoint control. Two NF-kappaB binding sites in the human cyclin D1 promoter conferred activation by NF-kappaB as well as by growth factors. Both levels and kinetics of cyclin D1 expression during G1 phase were controlled by NF-kappaB. Moreover, inhibition of NF-kappaB caused a pronounced reduction of serum-induced cyclin D1-associated kinase activity and resulted in delayed phosphorylation of the retinoblastoma protein. Furthermore, NF-kappaB promotes G1-to-S-phase transition in mouse embryonal fibroblasts and in T47D mammary carcinoma cells. Impaired cell cycle progression of T47D cells expressing an NF-kappaB superrepressor (IkappaBalphaDeltaN) could be rescued by ectopic expression of cyclin D1. Thus, NF-kappaB contributes to cell cycle progression, and one of its targets might be cyclin D1.

3T3 Cells↗
PubMed1997

[Long-term results and costs of elective bypass operation of infrarenal aortic aneurysm].

During a 10-years-period from 1978-1987 n = 545 patients were operated upon for infrarenal aortic aneurysm. Hospital mortality was 6.4%. In 95.6% of the patients information concerning state and cause of death were achieved. Cumulative survival was 64.6% at 5 years and 41.0% at 10 years, the mean survival being 95.1 month. Preoperative risk factors like age, coronary artery disease and hypertension had a negative impact on the long-term results. The costs were calculated according to the "Gesundheitsstrukturgesetz" and on the mean in-hospital-stay of 16.4 days.

Aged↗
PubMed1996

Domain analysis of human U5 RNA. Cap trimethylation, protein binding, and spliceosome assembly.

We have analyzed the sequence requirements of the human U5 RNA during small nuclear ribonucleoprotein (snRNP) and spliceosome assembly. A collection of mutant derivatives of the human U5 RNA gene was constructed in a U1 expression vector and transiently transfected in mammalian cells. Using immunoprecipitation and affinity selection assays, the cap trimethylation, the binding of Sm proteins and of the U5 snRNP-specific protein p220, as well as the assembly of the U4/U5/U6 triple snRNP and of spliceosomes were determined. By mutational analysis we were able to assign distinct functions to several structural elements of the human U5 RNA. Efficient binding of the Sm proteins requires the 3' stem-loop. Both the Sm protein-binding site and the 3' stem-loop are necessary for the formation of the trimethyl guanosine cap, consistent with Sm protein binding being a prerequisite for cap trimethylation. Specific elements of the U5 RNA 5' stem-loop contribute to efficient p220 association, in particular stem Ib. Interestingly, the highly conserved loop I appears to be a multifunctional element; in addition to its function in splice-site selection the 5' loop is involved in binding of p220 and in the assembly of the U4/U5/U6 triple snRNP. In sum, this mutational analysis has identified four functional domains of the human U5 RNA.

Animals↗
PubMed1993

Formation of DNA adducts from 1-hydroxymethylpyrene in liver cells in vivo and in vitro.

The binding of 1-hydroxymethylpyrene (HMP) and its active metabolites, 1-hydroxymethylpyrene sulfate (SMP) and 1-chloromethylpyrene (CMP), to DNA was studied. In the liver of rats, maximum adduct levels were observed 1.5 h after i.p. injection of HMP, followed by a relatively rapid decrease. Separate exposure of different liver cell types in vitro to HMP led to high adduct levels in parenchymal cells, intermediate levels (1/10) in endothelial cells and low levels (1/200) in Kupffer cells. The adduct patterns were similar in the different cell types. The same pattern was also obtained when isolated DNA was incubated with SMP or CMP. One of the four major spots co-chromatographed on TLC with a dG adduct, one with a dA adduct and one with both dG and dA adducts. The fourth spot did not co-chromatograph with any of the adducts observed in reactions with any nucleic acid homopolymer.

Animals↗
PubMed1990

[Retinol-binding protein, haptoglobin and ceruloplasmin--tumor markers in colorectal cancer?].

Retinol-binding protein, haptoglobin and ceruloplasmin were determined in the plasma of patients with colorectal carcinoma. The comparison with a control group shows that retinol-binding is significantly decreased in colorectal carcinoma and that haptoglobin and ceruloplasmin are significantly elevated. The ROC-curves of the three parameters, however, display a sensitivity distinctly lower than that of CEA, so that any use in the clinical treatment of colorectal carcinoma cannot be expected from the determination of these substances.

Adult↗
PubMed1990

[Preclinical biological testing of veneer composite materials].

The toxicity of commercial (Dentacolor, Visio-Gem) and other light reactive veneer composite materials under development (DG) was investigated by the hemolysis test. In contrast to a standard composite filling material (Evicrol) the veneer composite materials caused only small hemolysis rates.

Acrylic Resins↗
PubMed1987

Generation of oligomeric insulin receptor forms by intramolecular sulfhydryl-disulfide exchange. Involvement of masked sulfhydryl groups.

Insulin receptors from rat liver membranes were labelled with a 125I-labelled photoreactive insulin analogue or by iodination using lactoperoxidase and analysed by sodium dodecyl sulfate polyacrylamide gel electrophoresis. Under nonreducing conditions different receptor forms with Mr 400,000 (alpha 2 beta 2), 360,000 (alpha 2 beta beta'), 330,000 (alpha 2 beta' beta'), 320,000 (alpha 2 beta), 280,000 (alpha 2 beta'), 240,000 (alpha 2), 210,000 (alpha beta), 165,000 (alpha beta') and 115,000 (alpha) were detected. The subunit composition of these receptor forms was determined by two-dimensional sodium dodecyl sulfate polyacrylamide gel electrophoresis in the absence and presence of dithioerythritol. During denaturation in sodium dodecyl sulfate in the absence of reductants, the Mr 400,000 receptor form (alpha 2 beta 2) was converted into the Mr 320,000 (alpha 2 beta) and Mr 240,000 (alpha 2) receptor form. This conversion was prevented either by N-ethylmaleimide, oxidants, or low pH. In contrast, alkylation of the receptor with N-ethylmaleimide under non-denaturing conditions did not prevent the appearance of intermediate-sized receptor forms. Furthermore, the inhibition of receptor cleavage by N-ethylmaleimide during denaturation was also observed when the amount of free sulfhydryl groups was reconstituted by the addition of an unlabelled and non-alkylated receptor sample to the alkylated and photoaffinity-labelled receptor. These results suggest, that the generation of different oligomeric receptor forms detected by sodium dodecyl sulfate polyacrylamide gel electrophoresis is due at least in part to the cleavage of one or both beta-subunits from the insulin receptor.(ABSTRACT TRUNCATED AT 250 WORDS)

Affinity Labels↗