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T Fink

Publications and source records attributed to T Fink.

At least 37 records · Page 2Linked to original sources
PubMed1996

A palindromic structure in the pericentromeric region of various human chromosomes.

The primate-specific multisequence family chAB4 is represented with approximately 40 copies within the haploid human genome. Former analyis revealed that unusually long repetition units ( > 35 kb) are distributed to at least eight different chromosomal loci. Remarkably varying copy-numbers within the genomes of closely related primate species as well as the existence of human specific subfamilies, which most probably arose by frequent sequence exchanges, demonstrate that chAB4 is an unstable genomic element, at least in an evolutionary sense. To analyze the chAB4 basic unit in more detail we established a cosmid contig and found it to be organized as inverted duplications of approximately 90 kb flanking a noninverted core sequence of approximately 60 kb. FISH as well as the analysis of chromosome-specific hybrid cell lines revealed a chromosomal localization of chAB4 on chromosomes 1, 3, 4, 9, Y, and the pericentromeric region of all acrocentrics. Furthermore, we can detect chAB4 sequences together with alpha satellites, beta satellites, and satellite III sequences within a single chromosome 22-specific YAC clone, indicating that chAB4 is located in close proximity to the centromere, at least on the acrocentrics. Hence, chAB4 represents an unstable genomic structure that is located just in the chromosomal region that is very often involved in translocation processes.

Base Sequence↗
PubMed1996

Efficacy of current molecular cytogenetic protocols for the diagnosis of chromosome aberrations in tumor specimens.

Molecular cytogenetics provides a powerful link between molecular genetic analysis and chromosome morphology, allowing one to pinpoint structurally aberrant chromosome regions on the molecular level. Fluorescence in situ hybridization with selected DNA probes allows the design of efficient and sensitive tools for the diagnosis of chromosomal aberrations present in tumor cells. Comparative genomic hybridization (CGH) allows the identification of chromosomal imbalances in a comprehensive manner, and is applied to solid tumors and hematological malignancies in order to (i) identify clonal differences within a specimen, (ii) contribute to tumor classifications, (iii) identify recurrent chromosomal gains and losses as starting points for the characterization and isolation of pathogenetically relevant genes, such as proto-oncogenes and tumor suppressor genes respectively, (iv) identify imbalances of prognostic relevance, (v) detect high-copy-number amplification and other markers of genetic instability, and (vi) analyze chromosomal imbalances during tumor progression.

Chromosome Aberrations↗
PubMed1995

Follicular dendritic cells, interdigitating cells, and cells of the monocyte-macrophage lineage are the C1q-producing sources in the spleen. Identification of specific cell types by in situ hybridization and immunohistochemical analysis.

In a mouse model, we have shown previously that macrophages are the principal source of complement C1q. Furthermore, spleen, heart, and brain were found to contain substantial levels of murine C1q-specific mRNA, whereas liver, kidney, lung, and small intestine contained only trace amounts of C1q-specific mRNA. This work addresses the identification of C1q-expressing spleen cells in the rat, using Northern blotting and in situ detection of rat C1q mRNA combined with immunohistochemical analysis. The complete sequence of mRNA encoding the B chain of rat C1q was established. The cloned cDNA was found to hybridize primarily with spleen-derived mRNA of 1.2 kb, and additionally with a novel mRNA species of 3 kb. In situ hybridization together with immunohistochemistry revealed most of the C1q-expressing cells to be located in the red pulp of the spleen, and to be mainly of the monocyte-macrophage lineage, as indicated by coexpression of ED-1, an established marker for this type of cell. In addition, C1q was expressed in S-100-positive but ED-1-negative cells, in germinal center follicular dendritic cells, and in some interdigitating dendritic cells of the periarteriolar lymphatic sheath (PALS). These results indicate that the spleen, containing the above APCs that are all involved to a major extent in the adaptive immune response and are all capable of synthesizing C1q that is involved intimately in the innate immune response, may provide the site at which the innate and adaptive immune systems merge.

Amino Acid Sequence↗
PubMed1995

The major dermatomyositis-specific Mi-2 autoantigen is a presumed helicase involved in transcriptional activation.

OBJECTIVE: To characterize the complementary DNA (cDNA) and protein sequences of autoantigens recognized by anti-Mi-2 antibodies, using recombinant Mi-2 proteins for improved autoantibody detection. METHODS: A cDNA expression library was immunoscreened, and cDNA isolation, alignment, and sequence analysis were performed. Northern blotting and in situ hybridization techniques were used. A recombinant protein (rMi-2) was synthesized. Immunoprecipitation of 35S-methionine-labeled HEp-2 cell proteins and immunoblotting of rMi-2 and natural nuclear proteins were performed. Immunofluorescence studies were done with anti-Mi-2 positive sera of dermatomyositis (DM) patients, and with human or rabbit antibodies specific for rMi-2. Antibody screening of systemic lupus erythematosus, rheumatoid arthritis, DM, and antinuclear antibody-positive human sera was performed using an rMi-2 protein enzyme-linked immunosorbent assay (ELISA). RESULTS: A major antigen recognized by anti-Mi-2 positive sera of DM patients was found to constitute a 218-kd nuclear protein (218-kd Mi-2) encoded on chromosome 12 and to belong to the SNF2/RAD 54 helicase family. Human and rabbit antibodies that were affinity purified using the recombinant protein reacted with and precipitated a nuclear protein of similar size, which was also recognized by anti-Mi-2 sera. Anti-218-kd Mi-2 antibodies detected by rMi-2 protein ELISA seemed to be mainly restricted to sera from patients with DM. CONCLUSION: The molecular characterization of the 218-kd Mi-2 antigen may contribute to our understanding of autoimmune phenomena in DM. The use of immunoreactive recombinant proteins allows structural and functional studies of the helicase and the development of sensitive and accurate antibody screening tests.

Adenosine Triphosphatases↗
PubMed1995

Pro-enkephalin opioid peptides are abundant in porcine and bovine splenic nerves, but absent from nerves of rat, mouse, hamster, and guinea-pig spleen.

The opioidergic innervation of the mammalian spleen and possible species differences were investigated. Light-microscopic immunohistochemistry revealed that splenic nerves of bovine and porcine spleen, but not of rat, mouse, hamster and guinea-pig spleen contained proenkephalin-derived opioidergic innervation. Immunoreactivity to both prodynorphin and pro-opiomelanocortin was absent from splenic nerves. In bovine and porcine spleen, fibers immunoreactive for met-enkephalin, met-enkephalin-Arg-Phe, met-enkephalin-Arg-Gly-Leu, leu-enkephalin and peptide F formed perivascular plexus, traveled in trabecular connective tissue, and extended into the capsule. Spatial relationships with immune cells were apparent in the white and red pulp, excluding lymphoid follicles. Colocalization of enkephalin immunoreactivity with immunoreactivities for tyrosin hydroxylase, dopamin-beta-hydroxylase, and neuropeptide Y, but not for substance P or calcitonin gene-related peptide were found. Our results provide evidence that opioid expression in splenic innervation is strongly species-dependent and exclusively proenkephalin-derived. Colocalization with marker enzymes of noradrenergic neurons indicates a mainly postganglionic sympathetic origin of proenkephalinergic splenic innervation. Opioidergic perivascular nerves probably control the splenic blood flow. A close interrelationship of opioidergic fibers with immune cells provides the anatomical basis for direct effects of neurally released opioids on splenic immune functions.

Animals↗
PubMed1995

Changes of protein gene product 9.5 (PGP 9.5) immunoreactive nerves in inflamed appendix.

The existence of chronic appendicitis is controversial. In this prospective study, we investigated possible changes in the innervation of the appendix under different pathological conditions and correlated histological findings with clinical observation. Thirty appendectomy specimens and 14 appendices obtained from organ donors or patients who underwent right hemicolectomy were immediately fixed in Bouin's solution and processed for immunocytochemistry using an antiserum directed against the panneuronal marker protein gene product 9.5 (PGP 9.5). The density of PGP 9.5 immunostaining was evaluated by digitized morphometry. Significant differences in the density of the PGP 9.5-immunoreactive area were detected in the mucosal layer. In the nonacute appendicitis group, PGP 9.5 was increased (10.99 +/- 3.15%) as compared to acute appendicitis (3.89 +/- 1.77%) and controls (4.98 +/- 1.25%). The significant increase of PGP 9.5 in nonacute appendicitis may suggest axonal sprouting leading to hyperinnervation of the mucosa. This may be a neuronal factor in the pathophysiology of the disease and pain symptoms.

Abdominal Pain↗
PubMed1995

Expression of C1q, a subcomponent of the rat complement system, is dramatically enhanced in brains of rats with either Borna disease or experimental allergic encephalomyelitis.

In situ hybridization, RT-PCR and Northern blot analysis as well immunohistochemistry were used to examine the expression of C1q, a subcomponent of the rat complement system, in brains of rats infected with Borna disease virus (BDV) and rats afflicted with experimental allergic encephalomyelitis (EAE) induced by the adoptive transfer of myelin basic protein specific T cells. C1q mRNA, which was not detected in normal brain, became clearly detectable using RT-PCR analysis by d14 post infection (p.i.) with BDV. Maximal levels of C1q mRNA were reached 21 days p.i. when inflammatory reactions in the brain were also at a peak. Similarly, C1q mRNA was elevated when the clinical symptoms of EAE became evident 5 days following cell transfer. C1q positive cells, as identified by immunohistology, were preferentially localized in grey and white matter of the hippocampus and basolateral cortex. The C1q positive cells resembled microglial cells in morphology. The correlation of C1q expression with the development of neurological disease as well as the dramatic increase of C1q within brain regions with inflammatory lesions suggest that local biosynthesis of C1q may play a role in the pathogenesis of Borna virus induced and autoimmune encephalomyelitis.

Animals↗
PubMed1994

Distribution and chemical phenotypes of neuroendocrine cells in the human anal canal.

The presence, morphology and distribution of anal neuroendocrine cells were investigated with a panel of antisera and antibodies for neural markers, biogenic amines, and neuropeptides by the sensitive streptavidin-biotin-peroxidase immunocytochemistry, and coexistence patterns of neurochemically characterized neuroendocrine cells were examined by double immunofluorescence cytochemistry. In the colorectal zone, endocrine-like cells were immunoreactive for chromogranin A (CGA), serotonin (5-HT), pancreastatin (PST), peptide tyrosine tyrosine (PYY), glucagon-like peptide-1 (GLP-1), and somatostatin (SOM). Coexistence patterns of endocrine-like cell phenotypes with CGA and GLP-1 were heterogeneous. In the anal transitional zone (ATZ), endocrine-like cells were immunoreactive for CGA, 5-HT and PST. Furthermore, six new phenotypes of endocrine-like cells were characterized by their immunoreactivity for PYY, GLP-1, protein gene product 9.5 (PGP), calcitonin gene-related peptide (CGRP), neurotensin (NT), and SOM. All endocrine-like cell types in the ATZ were immunoreactive for CGA. In the squamous zone and perianal skin, CGA-immunopositive Merkel cells were also immunoreactive for CGRP, PST, NT and PGP. Neuroendocrine cells in the anal canal exhibit epithelial zone-related diversities in their neurochemical phenotypes and coexistence patterns, which may indicate specific regulatory functions. In the epithelium of the ATZ, which is regarded as metaplastic, endocrine-like cells expressed phenotypes characteristic of the neuroendocrine cells of the colorectal zone and the squamous zones, indicating a possible metaplastic origin of these cells.

Adolescent↗
PubMed1994

Human neutral amino acid transporter ASCT1: structure of the gene (SLC1A4) and localization to chromosome 2p13-p15.

Screening for cDNAs encoding proteins similar to the sodium-coupled glutamate transporter GLAST1 led to the isolation of a cDNA clone coding for a protein that turned out to be identical to the recently described neutral amino acid transporter ASCT1. The new member of the GLAST-related transporter family does not transport glutamate or aspartate but alanine, serine, cysteine, and threonine instead. The expressed sequence tag EST02446, a short cDNA sequence found in the course of a large-scale sequencing project of human brain-derived cDNAs, showed significant similarity to the eukaryotic glutamate transporter GLAST1 and was therefore used as probe in the search for further glutamate transporter cDNAs. Fragments of the cDNA were used for the isolation and characterization of human ASCT1 genomic clones. The ORF of 1572 bp encoding 524 amino acid residues is distributed over 8 exons, which span at least 40 kb of human chromosomal DNA. The ASCT1 gene locus was assigned to chromosome 2p13-p15 by chromosomal in situ suppression (CISS) studies. The gene structure is not related to any other previously characterized transporter gene. In contrast to the genes of the sodium-coupled nonglutamate neurotransmitter transporters, it shows no obvious correspondence between intron/exon structure and transmembrane organization. The transcription start site in human liver tissue was determined by primer extension analysis to be located 291 bp upstream of the initiating ATG codon. The DNA region immediately upstream of the transcription start lacks any TATA or CAAT boxes but contains several binding sites for the transcription factors Sp1 and Egr-1.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acid Sequence↗
PubMed1994

Human mitochondrial 3,2-trans-enoyl-CoA isomerase (DCI): gene structure and localization to chromosome 16p13.3.

A key enzyme in the mitochondrial beta-oxidation of unsaturated fatty acids is the 3,2-trans-enoyl-CoA isomerase (DCI; EC 5.3.3.8). It catalyzes the transformation of 3-cis and 3-trans intermediates arising during the stepwise degradation of all cis-, mono-, and polyunsaturated fatty acids to the 2-trans-enoyl-CoA intermediates. A genomic clone encoding the human DCI was isolated and characterized by use of the previously cloned human DCI cDNA. The entire gene encompasses approximately 12.5 kb, and the coding sequence is distributed over seven exons. One major and three minor transcription start sites were determined by primer extension analysis. In common with promoters of other housekeeping genes encoding mitochondrial proteins, the GC-rich, immediate 5'-flanking region of the DCI transcription initiation site lacks typical TATA and CAAT boxes; instead, two GC box consensus sequences are present. Introns 2 and 6 contain several Alu repetetive sequences. The human DCI gene locus was assigned to chromosome 16 by use of human-rodent somatic cell hybrids and to chromosome 16p13.3 by chromosomal in situ suppression hybridization studies.

Animals↗
PubMed1994

The human Met-ase gene (GZMM): structure, sequence, and close physical linkage to the serine protease gene cluster on 19p13.3.

Cosmid clones containing the genes for the human and murine natural killer cell serine protease Met-ase (gene symbol GZMM; granzyme M) were identified by screening human and murine cosmid libraries with rat Met-ase (RNK-Met-1) cDNA. The human gene has a size of 7.5 kb and an exon-intron structure identical to that of serine protease genes located on human chromosomes 5q11-q12, 14q11.2, and 19p13.3 that are expressed by lymphocytes, mast cells, or myelomonocyte precursors. Using cosmid DNA as a probe for fluorescence in situ hybridization, we identified the chromosomal position of human Met-ase as 19p13.3. Interphase studies with two differentially labeled probes for Met-ase and the azurocidin (AZU1), proteinase 3 (PRTN3), and neutrophil elastase (ELA2) gene cluster revealed that the distance of Met-ase from this gene cluster is in the range of 200 to 500 kb. Using differentially labeled mouse cosmid probes, we also mapped the murine gene for Met-ase to chromosomal band 10C, close to the gene for lamin B2. Thus, the Met-ase, AZU1, PRTN3, and ELA2 genes fall into an established region of homology between mouse chromosomal band 10C and human 19p13.3.

Amino Acid Sequence↗
PubMed1994

Distribution and relative proportions of neuropeptide Y- and proenkephalin-containing noradrenergic neurones in rat superior cervical ganglion: separate projections to submaxillary lymph nodes.

The distribution and relative proportions of neuropeptide Y (NPY)- and [Met]enkephalyl-Arg-Gly-Leu (ME-RGL)-containing sympathetic neurones in the rat superior cervical ganglion (SCG) and their projections to submaxillary lymph nodes (SLN) were determined by retrograde tracing and immunocytochemistry. Three subpopulations of neurones were detected in the SCG: 64% contained NPY, 30% contained ME-RGL, and 6% were immunonegative for both. Immunoreactive neurones were also present inside the external carotid nerve of the SCG. An injection of Fluoro-Gold (FG) into the left SLN retrogradely labeled a few neurones in the ipsilateral SCG. FG-labeled neurones contained tyrosine hydroxylase (TH) and were either positive for ME-RGL or for NPY. FG-labeled neurones immunostained for ME-RGL out-numbered by 4:1 FG-labeled neurones immunopositive for NPY. It is suggested that the sympathetic/peptidergic innervation to SLN may have distinct vasoregulatory and immunomodulatory functions.

Animals↗
PubMed1994

Growth-associated protein-43 and protein gene-product 9.5 innervation in human pancreas: changes in chronic pancreatitis.

Growth-associated protein-43, an established marker of neuronal plasticity during development and in injury, was used to characterize innervation in the normal human pancreas and changes in chronic alcohol-induced pancreatitis by using light microscopic immunocytochemistry and computer-assisted image analysis. Immunostaining for the pan-neuronal marker protein gene-product 9.5 served as a reference for the characterization of total innervation in both groups. In normal human pancreas, strong protein gene-product 9.5 immunostaining revealed all nerve fibres in nerve trunks, all neuronal cell bodies and the entire parenchymal innervation. In contrast, growth-associated protein-43 immunoreactivity was restricted to a few nerve fibres in interlobular nerve trunks and to fine varicose nerve fibres supplying the parenchyma, blood vessels, pancreatic ducts and intrinsic ganglia. In cell bodies of intrinsic neurons, growth-associated protein-43 immunoreactivity was absent or extremely faint. In chronic pancreatitis, the protein gene-product 9.5 innervation exhibited region-specific changes. In areas with reduced parenchyma, the protein gene-product 9.5 innervation was sparse. In fibrotic regions, which are characteristic for advanced stages of chronic pancreatitis, enlarged nerve trunks showing neuroma-like formations were heavily stained for protein gene-product 9.5. In fibrotic tissue, protein gene-product 9.5-containing nerve fibres were extremely rare. The growth-associated protein-43 innervation in chronic pancreatitis was characterized by a dramatic increase, which was most pronounced in the enlarged nerve trunks. Such nerve trunks were frequently surrounded by infiltrates of immune cells, which in some cases formed follicle-like structures. Digital image analysis of adjacent sections and double fluorescence immunocytochemistry revealed that growth-associated protein-43 immunoreactivity was present in the vast majority of protein gene-product 9.5-immunoreactive nerve fibres. In contrast to the normal pancreas, a major subpopulation of intrinsic neurons immunostained for growth-associated protein-43. The expression of growth-associated protein-43 in the terminal fields of pancreatic nerve suggests that the innervation of the normal human pancreas undergoes continual and toposelective remodelling. The increase in the density of growth-associated protein-43 immunoreactive nerve fibres in enlarged nerve trunks paralleled by augmented expression of growth-associated protein-43 in intrinsic neurons and reduced parenchymal growth-associated protein-43-immunoreactive innervation underline the dramatic plasticity of pancreatic innervation in chronic pancreatitis.(ABSTRACT TRUNCATED AT 400 WORDS)

Adolescent↗
PubMed1994

Molecular cytogenetic analysis of RB-1 deletions in chronic B-cell leukemias.

Deletions or translocations of 13q, most commonly involving band 13q14, belong to the most frequent structural chromosome abnormalities in B-cell chronic lymphocytic leukemia (B-CLL). In a combined metaphase and interphase cytogenetic study using conventional G-banding analysis and fluorescence in situ hybridization (ISH) we previously analysed the retinoblastoma susceptibility gene (RB-1) and its chromosomal locus 13q14 in 35 patients with chronic B-cell leukemias. We report here on the interphase cytogenetic analysis of 109 cases with chronic B-cell leukemias [B-CLL = 90; B-prolymphocytic leukemia (B-PLL) = 6, hairy cell leukemia (HCL) = 13]; a subset of 49 patients (B-CLL = 45; B-PLL = 4) was studied by conventional G-banding analysis. By G-banding, 5/45 (11%) patients with B-CLL had deletions or translocations affecting band 13q14; in contrast, ISH to interphase cells showed RB-1 deletion in 19/90 (21%) patients with B-CLL. No 13q14 abnormalities or RB-1 deletion were detected in patients with B-PLL and HCL. Our data confirm the high frequency of RB-1 deletions in B-CLL and further emphasize the possible pathogenetic role of this genomic region.

Adult↗
PubMed1994

Biological activities of a putative truncated hepatitis B virus X gene product fused to a polylysin stretch.

Truncated transcripts terminating within the HBx frame have been recognized previously in tumor and liver tissue of HCC patients. In this study biological activities of a predicted truncated HBx fused to a polylysin stretch (HBtx-polylysin) and of full length HBx were compared in NIH3T3 cells transfected with respective cDNA plasmids. Transactivation of a co-transfecting reporter gene and influence on neor DNA mediated transformation to G418 resistance were determined. In comparison to full length HBx the data indicate for HBtx-polylysin a lower transactivating capacity and as judged by the yield of colonies on a solid surface, a lower capacity to stimulate neor DNA mediated transformation. In soft agar the outgrowth into G418 resistant colonies was dependent on co-transfecting HBx cDNA. In providing this condition HBtx-polylysin had a much higher relative activity than full length HBx. Large cointegrants consisting of the plasmids carrying truncated HBx cDNA and neor DNA respectively were identified by chromosomal in situ hybridization. Based on Southern blot analyses extended concatemeres of the HBx cDNA plasmid constituted a main part of the cointegrants. Expression of truncated HBx cDNA was followed on the RNA and the protein level. The presence of this cDNA could be correlated to a compact spindle like cell appearance, its loss after prolonged passaging in the absence of G418 to a concomitant reversion to the phenotype of the NIH3T3 cell. Interspersed selection for G418 resistance stabilized the morphologically transformed phenotype. These results provide a basis to manipulate expression of truncated HBx and to recognize thereby processes leading to transformation.

3T3 Cells↗