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A Jauch

Publications and source records attributed to A Jauch.

At least 73 records · Page 4Linked to original sources
PubMed1996

Identification of complex chromosome rearrangements in the gibbon by fluorescent in situ hybridization (FISH) of a human chromosome 2q specific microlibrary, yeast artificial chromosomes, and reciprocal chromosome painting.

Chromosome painting has revealed that the human chromosome homologs in lesser apes are often fragmented and translocated to a number of different hylobatid chromosomes. We investigated the fragmented human chromosome 2 homologs in gibbons to illustrate a new strategy in mapping regional and band-specific chromosomal homologies between species. Previous research showed that the DNA library specific to human chromosome 2 paints parts of four gibbon (lar species group) chromosomes (viz., 1, 10, 12, and 16) and yields five distinct hybridization signals (including two on gibbon chromosome 16). However, the exact segments of human chromosome 2 that were translocated to the various gibbon chromosomes could not be distinguished. To determine the origin of the human chromosome 2 signals, we hybridized a microlibrary for the long arm of human chromosome 2, as well as YACs specific for most of the major bands on this chromosome, to metaphases of the gibbon. For reciprocal chromosome painting, we hybridized flow-sorted gibbon chromosome probes to human chromosome 2. Each method added additional insights that helped clarify the shuffling of human chromosome 2 material in the highly reorganized gibbon genome. There was an excellent correspondence between these complementary techniques. YAC 958d2 identified the breakpoint between human chromosome 2 material present on gibbon chromosomes 10 and 16. The reciprocal chromosome painting permitted a more complete and regional assignment of homology between segments on various gibbon chromosomes to human chromosome 2. The results show that a combination of reciprocal chromosome painting, subregional microlibraries, and band-specific probes (such as YACs) can be used to identify homologies between species and to rapidly construct detailed comparative chromosome maps, especially when the karyotypes are highly rearranged.

Animals↗
PubMed1995

Investigations with fluorescence in situ hybridization (FISH) demonstrate loss of the telomeres on the reciprocal chromosome in three unbalanced translocations involving chromosome 15 in the Prader-Willi and Angelman syndromes.

Two patients with classical features of Angel-man syndrome (AS) and one with Prader-Willi syndrome (PWS) had unbalanced reciprocal translocations involving the chromosome 15 proximal long arm and the telomeric region of chromosomes 7, 8 and 10. Fluorescence in situ hybridization (FISH) was used for the detection of chromosome 15(q11-13) deletions (with probes from the PWS/AS region) and to define the involvement of the telomere in the derivative chromosomes (with library probes and telomere-specific probes). The 15(q11-13) region was not deleted in one patient but was deleted in the other two. The telomere on the derivative chromosomes 7, 8 and 10 was deleted in all three cases. Thus, these are true reciprocal translocations in which there has been loss of the small satellited reciprocal chromosome (15) fragment.

Adult↗
PubMed1995

Bacterial keratitis therapy in guinea pigs with lomefloxacin by initially high-followed by low-dosage regimen.

Lomefloxacin is known to have an excellent corneal penetration. The therapeutic effect of two specific treatment regimens with lomefloxacin 0.3% eye drops was studied in a Pseudomonas aeruginosa-induced keratitis model in guinea pigs. An initial loading dose of 1 drop every 5 min for 5 times was used in all groups. Its purpose was to obtain high bactericidal corneal levels in the two actively treated groups. The follow-up treatment for 7 days was by a twice daily regimen in one group and 3 times daily in the other treated group. There were two control groups - one with no treatment and the other with vehicle treatment (initial loading dose followed by twice daily regimen). Clinical signs of cornea, conjunctiva and eye adnexae improved significantly within 2 days in both lomefloxacin regimens, whereas clinical signs deteriorated with vehicle treatment. Fifty percent of the animals treated with lomefloxacin showed no colonies in the swab culture after 2 days of therapy, while all vehicle-treated animals were positive even at day 6, with 5 out of 9 animals continuing to be positive at day 8. Pseudomonas in the range of 100-2,300 colonies was isolated from the grounded and cultured cornea at the end of the study in 4 out of 9 vehicle-treated animals but in none of the lomefloxacin-treated guinea pigs. The biggest difference in the degree of secondary inflammation between lomefloxacin and vehicle-treated groups was observed in the cornea which was the target tissue of infection. An unexpected observation was the lower degree of corneal inflammation in the twice daily treated animals when compared to the 3 times daily treatment group. This finding may be due to the somewhat lower initial degree of corneal inflammation in this group and suggests that the course of corneal recovery is predominately dependent on the initial degree of infection with both dosage regimens of lomefloxacin capable of eradicating corneal organisms.

Animals↗
PubMed1995

Correlation of microscopic phenotype with genotype in a formalin-fixed, paraffin-embedded testicular germ cell tumor with universal DNA amplification, comparative genomic hybridization, and interphase cytogenetics.

We present a strategy for the evaluation of numerical copy number changes of DNA segments within a solid tumor genome that allows the correlation of microscopic phenotype with genotype in formalin-fixed, paraffin-embedded tumor material. Cells from a human testicular germ cell tumor and adjacent tissue areas with normal seminiferous tubules were selected separately from microscopically analyzed histological tissue sections, and DNA was extracted from the selected areas. After universal DNA amplification, the amplification products were subjected to comparative genomic hybridization. The results confirmed balanced chromosome copy numbers for the normal tissue area, although the analysis of the tumor tissue area revealed numerous gains and losses of chromosome segments. The comparative genomic hybridization results were used to select DNA probes for interphase cytogenetics on serial sections. We conclude that this technique allows the screening of selected tissue areas for numerical DNA alterations, thus enabling a direct phenotype-genotype comparison.

Adult↗
PubMed1994

Chromosomal gains and losses in uveal melanomas detected by comparative genomic hybridization.

Eleven uveal melanomas were analyzed using comparative genomic hybridization (CGH). The most abundant genetic changes were loss of chromosome 3, overrepresentation of 6p, loss of 6q, and multiplication of 8q. The smallest overrepresented regions on 6p and 8q were 6pter-->p21 and 8q24-->qter, respectively. Several additional gains and losses of chromosome segments were repeatedly observed, the most frequent one being loss of 9p (three cases). Monosomy 3 appeared to be a marker for ciliary body involvement. CGH data were compared with the results of chromosome banding. Some alterations, e.g., gains of 6p and losses of 6q, were observed with higher frequencies after CGH, while others, e.g., 9p deletions, were detected only by CGH. The data suggest some similarities of cytogenetic alterations between cutaneous and uveal melanoma. In particular, the 9p deletions are of interest due to recent reports about the location of a putative tumor-suppressor gene for cutaneous malignant melanoma in this region.

Adult↗
PubMed1994

Detection of 14q32 translocations in B-cell malignancies by in situ hybridization with yeast artificial chromosome clones containing the human IgH gene locus.

Partner sites of 14q32 translocations found in B-cell malignancies were detected by fluorescence in situ hybridization (FISH) using yeast artificial chromosome (YAC) clones, Y20 and Y6, containing the human Ig heavy chain (IgH) gene locus. Y20 spans a 160-kb upstream and 40-kb downstream region of the JH segments on chromosome band 14q32.33. Y6 is 300-kb upstream of Y20, and spans a further 320-kb telomeric region. The human DNA sequences amplified by Alu polymerase chain reaction of the YAC clones were used as probes for FISH to study six patients with non-Hodgkin's lymphoma (NHL), one patient with acute lymphoblastic leukemia, and one cell line FR4 established from a plasmacytoma. Three telomeric YAC clones each specific for 3q, 8q, and 18q were also used to further characterize 14q32 translocations. The IgH YACs were successfully applied to detect cytogenetically invisible subtelomeric translocation of the IgH gene locus to each partner site in t(14;18), t(8;14), and t(14;19), and to identify t(3;14) (q27;q32.33) in three patients with 14q32 translocation of unknown origin. Furthermore, complex translocations involving more than three chromosomes were detected in an NHL patient with t(8;14), and t(3;12), and in the FR4 with der(14)t(8;14), der(8)dic(1;8), and del(1)(q21). The technique would be a useful tool in elucidating the mechanisms of a 14q32 translocation in B-cell malignancies.

Aged↗
PubMed1994

The origin of human chromosome 2 analyzed by comparative chromosome mapping with a DNA microlibrary.

Fluorescence in situ hybridization (FISH) of microlibraries established from distinct chromosome subregions can test the evolutionary conservation of chromosome bands as well as chromosomal rearrangements that occurred during primate evolution and will help to clarify phylogenetic relationships. We used a DNA library established by microdissection and microcloning from the entire long arm of human chromosome 2 for fluorescence in situ hybridization and comparative mapping of the chromosomes of human, great apes (Pan troglodytes, Pan paniscus, Gorilla gorilla, Pongo pygmaeus) and Old World monkeys (Macaca fuscata and Cercopithecus aethiops). Inversions were found in the pericentric region of the primate chromosome 2p homologs in great apes, and the hybridization pattern demonstrates the known phylogenetically derived telomere fusion in the line that leads to human chromosome 2. The hybridization of the 2q microlibrary to chromosomes of Old World monkeys gave a different pattern from that in the gorilla and the orang-utan, but a pattern similar to that of chimpanzees. This suggests convergence of chromosomal rearrangements in different phylogenetic lines.

Animals↗
PubMed1994

Comparative genomic hybridization of human malignant gliomas reveals multiple amplification sites and nonrandom chromosomal gains and losses.

Nine human malignant gliomas (2 astrocytomas grade III and 7 glioblastomas) were analyzed using comparative genomic hybridization (CGH). In addition to the amplification of the EGFR gene at 7p12 in 4 of 9 cases, six new amplification sites were mapped to 1q32, 4q12, 7q21.1, 7q21.2-3, 12p, and 22q12. Nonrandom chromosomal gains and losses were identified with overrepresentation of chromosome 7 and underrepresentation of chromosome 10 as the most frequent events (1 of 2 astrocytomas, 7 of 7 glioblastomas). Gain of a part or the whole chromosome 19 and losses of chromosome bands 9pter-23 and 22q13 were detected each in five cases. Loss of chromosome band 17p13 and gain of chromosome 20 were revealed each in three cases. The validity of the CGH data was confirmed using interphase cytogenetics with YAC clones, chromosome painting in tumor metaphase spreads, and DNA fingerprinting. A comparison of CGH data with the results of chromosome banding analyses indicates that metaphase spreads accessible in primary tumor cell cultures may not represent the clones predominant in the tumor tissue.

Adolescent↗
PubMed1993

Characterization of two marker chromosomes in a patient with acute nonlymphocytic leukemia by two-color fluorescence in situ hybridization.

A patient with acute nonlymphocytic leukemia (ANLL), M5b according to French-American-British (FAB) classification, showed monosomy 16, an extra 1p-, and a 21q+. These derivative chromosomes could not be defined by GTG-banding. For better characterization, we performed two-color fluorescence in situ hybridization (FISH) experiments applying DNA libraries from sorted human chromosomes, chromosome-specific repetitive probes, and a band-specific YAC-clone. With these FISH studies the karyotype could be characterized as 46,XY, +der(1)t(1;21)(p11;?), -16,der(21)t(16;21) (p11.1;q22).

Adult↗
PubMed1993

A strategy for the characterization of minute chromosome rearrangements using multiple color fluorescence in situ hybridization with chromosome-specific DNA libraries and YAC clones.

The identification of marker chromosomes in clinical and tumor cytogenetics by chromosome banding analysis can create problems. In this study, we present a strategy to define minute chromosomal rearrangements by multicolor fluorescence in situ hybridization (FISH) with "whole chromosome painting" probes derived from chromosome-specific DNA libraries and Alu-polymerase chain reaction (PCR) products of various region-specific yeast artificial chromosome (YAC) clones. To demonstrate the usefulness of this strategy for the characterization of chromosome rearrangements unidentifiable by banding techniques, an 8p+ marker chromosome with two extra bands present in the karyotype of a child with multiple anomalies, malformations, and severe mental retardation was investigated. A series of seven-color FISH experiments with sets of fluorochrome-labeled DNA library probes from flow-sorted chromosomes demonstrated that the additional segment on 8p+ was derived from chromosome 6. For a more detailed characterization of the marker chromosome, three-color FISH experiments with library probes specific to chromosomes 6 and 8 were performed in combination with newly established telomeric and subtelomeric YAC clones from 6q25, 6p23, and 8p23. These experiments demonstrated a trisomy 6pter-->6p22 and a monosomy 8pter-->8p23 in the patient. The present limitations for a broad application of this strategy and its possible improvements are discussed.

Abnormalities, Multiple↗
PubMed1993

Delineation of translocation t(15; 17) in acute promyelocytic leukemia by chromosomal in situ suppression hybridization.

In this study we demonstrate the feasibility of chromosomal in situ suppression (CISS) hybridization to detect the translocation t(15; 17) in metaphase spreads of patients with acute promyelocytic leukemia. Using DNA libraries from sorted human chromosomes 15 and 17 the translocation t(15; 17) can be unequivocally identified even if the spread and the morphology of the chromosomes are poor. The sensitivity of CISS hybridization is compared with the sensitivity of conventional G-banded karyotypes.

Adult↗
PubMed1993

Chromosomal bar codes produced by multicolor fluorescence in situ hybridization with multiple YAC clones and whole chromosome painting probes.

Colored chromosome staining patterns, termed chromosomal 'bar codes' (CBCs), were obtained on human chromosomes by fluorescence in situ hybridization (FISH) with pools of Alu-PCR products from YAC clones containing human DNA inserts ranging from 100 kbp to 1 Mbp. In contrast to conventional G- or R-bands, the chromosomal position, extent, individual color and relative signal intensity of each 'bar' could be modified depending on probe selection and labeling procedures. Alu-PCR amplification products were generated from 31 YAC clones which mapped to 37 different chromosome bands. For multiple color FISH, Alu-PCR amplification products from various clones were either biotinylated or labeled with digoxigenin. Probes from up to twenty YAC clones were used simultaneously to produce CBCs on selected human chromosomes. Evaluation using a cooled CCD camera and digital image analysis confirmed the high reproducibility of the bars from one metaphase spread to another. Combinatorial FISH with mixtures of whole chromosomes paint probes was applied to paint seven chromosomes simultaneously in different colors along with a set of YAC clones which map to these chromosomes. We discuss the potential to construct analytical chromosomal bar codes adapted to particular needs of cytogenetic investigations and automated image analysis.

Chromosome Banding↗
PubMed1992

Reconstruction of genomic rearrangements in great apes and gibbons by chromosome painting.

The homology between hylobatid chromosomes and other primates has long remained elusive. We used chromosomal in situ suppression hybridization of all human chromosome-specific DNA libraries to "paint" the chromosomes of primates and establish homologies between the human, great ape (chimpanzee, gorilla, and orangutan), and gibbon karyotypes (Hylobates lar species group, 2n = 44). The hybridization patterns unequivocally demonstrate the high degree of chromosomal homology and synteny of great ape and human chromosomes. Relative to human, no translocations were detected in great apes, except for the well-known fusion-origin of human chromosome 2 and a 5;17 translocation in the gorilla. In contrast, numerous translocations were detected that have led to the massive reorganization of the gibbon karyotype: the 22 autosomal human chromosomes have been divided into 51 elements to compose the 21 gibbon autosomes. Molecular cytogenetics promises to finally allow hylobatids to be integrated into the overall picture of chromosomal evolution in the primates.

Animals↗
PubMed1992

Molecular and classical cytogenetic analyses demonstrate an apomorphic reciprocal chromosomal translocation in Gorilla gorilla.

The existence of an apomorphic reciprocal chromosomal translocation in the gorilla lineage has been asserted or denied by various cytogeneticists. We employed a new molecular cytogenetic strategy (chromosomal in situ suppression hybridization) combined with high-resolution banding, replication sequence analysis, and fluorochrome staining to demonstrate that a reciprocal translocation between ancestral chromosomes homologous to human chromosome 5 and 17 has indeed occurred.

Animals↗
PubMed1992

Homologies in human and Macaca fuscata chromosomes revealed by in situ suppression hybridization with human chromosome specific DNA libraries.

We established chromosomal homologies between all chromosomes of the human karyotype and that of an old world monkey (Macaca fuscata) by chromosomal in situ suppression (CISS) hybridization with human chromosome specific DNA libraries. Except for the human chromosome 2 library and limited cross-hybridization of X and Y chromosome libraries all human DNA libraries hybridized to single GTG-banded macaque chromosomes. Only three macaque chromosomes (2, 7, 13) were each hybridized by two separate human libraries (7 and 21, 14 and 15, 20 and 22 respectively). Thus, an unequivocally high degree of synteny between human and macaque chromosomes has been maintained for more than 20 million years. As previously suggested, both Papionini (macaques, baboons, mandrills and cercocebus monkeys, all of which have nearly identical karyotypes) and humans are chromosomally conservative. The results suggest, that CISS hybridization can be expected to become an indispensable tool in comparative chromosome and gene mapping and will help clarify chromosomal phylogenies with speed and accuracy.

Animals↗
PubMed1992

Somatic mosaicism for a deletion of the dystrophin gene in a carrier of Becker muscular dystrophy.

Duchenne muscular dystrophy (DMD) and the allelic milder form of Becker muscular dystrophy (BMD) are caused by mutations of the dystrophin gene on the short arm of the X chromosome. One third of affected individuals are expected to result from de novo mutations. Genetic counselling of families with sporadic cases is complicated by the potential meiotic origin of the mutation in the mother resulting in germline mosaicism. Here we present direct evidence for combined somatic and germline mosaicism for a deletion of the dystrophin gene, thereby proving the mitotic origin of this deletion and pinpointing a further potential pitfall for genetic counselling. The mother of a BMD son and a BMD carrier daughter, both carrying a deletion of dystrophin cDNA 7 (0.5 kb Hind III fragment) and cDNA 8, was herself clinically healthy and had normal creatine kinase levels. A muscle specimen of the mother showed mild overall pathology as well as focal dystrophin deficiency. In contrast chromosomal in situ suppression (CISS) hybridization of metaphase chromosomes using a cosmid clone of the corresponding cDNA deleted in her son revealed no evidence of somatic mosaicism in their lymphocytes. These results emphasize the value of an approach correlating genetic and immunological data for the definition of a carrier state in BMD or DMD. The possibility of somatic mosaicism should be considered when genetic counselling of a family with a sporadic case of BMD or DMD is performed.

Blotting, Southern↗