Biomedical subjects

A Jauch

Publications and source records attributed to A Jauch.

At least 55 records · Page 3Linked to original sources

PubMed1998

The human small conductance calcium-regulated potassium channel gene (hSKCa3) contains two CAG repeats in exon 1, is on chromosome 1q21.3, and shows a possible association with schizophrenia.

Mutations in various ion channel genes are responsible for neuromuscular and other neurological disorders. We have previously identified the human small conductance calcium-activated potassium channel gene (hSKCa3) which has two tandemly arranged CAG repeats in its 5' region. Here we have isolated the first genomic clones containing the gene and have shown that both repeats are in exon 1. Homology to the previously localized sequence tagged site G16005 indicated that the gene may be on chromosome 22q, however using polymerase chain reaction amplification of somatic cell hybrid DNA and fluorescence in situ hybridization of two P1 artificial chromosome clones, we physically localized the gene to chromosome 1q21.3. We previously found an association between the highly polymorphic second (more 3') CAG repeat and schizophrenia in 98 patients and 117 controls. We have now genotyped an additional 19 patients with schizophrenia and have performed statistical analyses on the entire group of patients and controls to investigate the possible effect of age of onset, family history, and gender of the patients on the observed association. None of these factors were found to influence the results. Both CAG repeats have been typed in 86 bipolar I disorder patients, and no significant difference in allele distribution was observed between our bipolar disorder patients and controls.

Animals↗

PubMed1998

Corneal penetration of diclofenac from a fixed combination of diclofenac-gentamicin eyedrops.

PURPOSE: To establish the corneal penetration of diclofenac in the presence of gentamicin in patients having cataract surgery. SETTING: Kantonsspital Augenklinik, Aarau, and Hôpital Jules Gonin, Lausanne, Switzerland. METHODS: Eligible patients having cataract surgery (39 women, 30 men) were treated with 4 drops of diclofenac 0.1%-gentamicin 0.3% (Voltamicin) instilled at 20 minute intervals. Paracentesis was performed 15, 30, or 60 minutes after the last instillation, and a sample of aqueous humor was collected for analysis of diclofenac by high-performance liquid chromatography. Blood samples of some patients were obtained before surgery for analysis. RESULTS: Mean diclofenac levels (+/- SD) in the aqueous humor 15, 30, and 60 minutes after the last instillation were 72 +/- 84, 108 +/- 87, and 201 +/- 116 ng/mL (= 682 nMol/L), respectively. Diclofenac remained below the limit of detection (5 ng/mL) in all samples of blood serum. In general, local tolerance was good; no side effects were reported. Comparison of the data with published results of topically instilled diclofenac 0.1% suggests that the concentration of diclofenac in the aqueous humor achieved with 4 instillations of the combination product is similar to that achieved with 8 instillations of diclofenac 0.1% (Voltaren Ophtha) alone. CONCLUSIONS: Drug levels of diclofenac in the aqueous humor well above IC-50 for cyclo-oxygenase were achieved with the regimen applied. No inhibitory effect by the gentamicin or vehicle was observed. Comparison of these data with published results of Voltaren Ophtha implies a 2-fold better penetration of diclofenac with the diclofenac-gentamicin combination.

Aged↗

PubMed1998

Separate and variably shaped chromosome arm domains are disclosed by chromosome arm painting in human cell nuclei.

Fluorescence in situ hybridization (FISH) with microdissection probes from human chromosomes 3 and 6 was applied to visualize arm and subregional band domains in human amniotic fluid cell nuclei. Confocal laser scanning microscopy and quantitative three-dimensional image analysis showed a pronounced variability of p- and q-arm domain arrangements and shapes. Apparent intermingling of neighbouring arm domains was limited to the domain surface. Three-dimensional distance measurements with pter and qter probes supported a high variability of chromosome territory folding.

Amniotic Fluid↗

PubMed1998

Aspects of three-dimensional chromosome reorganization during the onset of human male meiotic prophase.

The three-dimensional morphology and distribution of human chromosomes 3 were studied in nuclei of spermatogonia and spermatocytes I from formaldehyde-fixed human testis sections. Chromosome arms, pericentromeres and telomeric regions were painted by a three-color, five-probe fluorescence in situ hybridization protocol. Light optical serial sections of premeiotic and meiotic nuclei obtained by confocal laser scanning microscopy revealed that premeiotic chromosomes 3 are separate from each other and occupy variably shaped territories, which are sectored in distinct 3 p- and q-arm domains. Three-dimensional reconstructions of the painted chromosome domains by a Voronoi tessellation approach showed that mean chromosome volumes did not differ significantly among the premeiotic and meiotic stages investigated. A significant increase in surface area and reduction of dimensionless 'roundness factor' estimates of arm domains indicated that the restructuring of spatially separate chromosome territories initiates during preleptotene. Telomeric regions, which in meiotic stem cells located predominantly in arm-domain chromatin, showed a redistribution towards the domain surface during this stage. At leptotene homologues were generally misaligned and displayed intimate intermingling of non-homologous chromatin. Pairing initiated at the ends of bent zygotene chromosomes, which displayed a complex surface structure with discernible sister chromatids. The results indicate that, in mammals, homology search is executed during leptotene, after remodeling of chromosome territories.

Chromatin↗

PubMed1997

Molecular cloning of the interleukin-1 gene cluster: construction of an integrated YAC/PAC contig and a partial transcriptional map in the region of chromosome 2q13.

Genes of the interleukin-1 (IL-1) gene cluster localized on chromosome 2q13 are implicated in many physiological and pathophysiological processes. We present here a high-resolution physical map of this region between markers D2S2008 and D2S4/PAX8. An integrated YAC/PAC contig and a partial transcriptional map were constructed by STS-constent mapping using the CEPH YAC library and three PAC libraries. A total of 3 YACs, 34 PACs, and 56 STSs were integrated: 33 newly generated probes to PAC end sequences, 9 polymorphic and 4 nonpolymorphic markers, 5 known genes, 4 expressed sequence tags, and 1 pseudogene. Within the map, a complete PAC contig of > 1 Mb encompasses the IL-1 gene cluster and PAX8, a paired-box-containing gene. This allowed us to define the transcriptional orientation of GLVR1, IL1B, and IL1RN and to show that PAX8 is localized outside the IL-1 gene cluster. FISH analysis localized PAC clones containing the IL-1 gene cluster to 2q12-q13. The data provide the basis for further characterization of the IL-1 gene cluster and for the construction of a sequence-ready PAC contig of this region.

Base Sequence↗

PubMed1997

Comparison of DNA gains and losses in primary renal clear cell carcinomas and metastatic sites: importance of 1q and 3p copy number changes in metastatic events.

Archival material from primary and metastatic renal clear cell carcinomas of 25 patients was studied by comparative genomic hybridization. Copy number changes of entire chromosomes or chromosomal subregions were detected in 22 primary and 21 metastatic tumors. Copy number changes affected the following chromosomes in at least 20% of the 25 primary tumors (minimal common region given in parentheses): gains were noted for chromosomes 1 (1q21-->q23), 5 (5q31-->q34), 7 (7p), 8 (8q), 16 (16p), 17 (17q12-->qter), 19, and 22 (22q12-->qter); losses were revealed for chromosomes 3 (3p21-->pter), 8 (8p23-->pter), 14(14q21-->qter), and Y. The same chromosomal regions that were involved in primary renal clear cell carcinomas were also found in the respective metastatic tumors but with strikingly different frequencies for a few regions. Metastatic tumors showed a significantly higher frequency of complete or partial gains of the long arm of chromosome 1, in particular at 1q21-->q23 than primary tumors (16 cases versus 6 cases; P < 0.005). These data suggest a correlation of metastatic events in renal clear cell carcinomas with an increase in the copy number of genes located at 1q, in particular at 1q21-->q23. In contrast, the entire or partial loss of the short arm of chromosome 3 was significantly less frequent in metastatic tumors (8 cases versus 15 cases; P < 0.025). The validity of 1q and 3p copy number changes detected by comparative genomic hybridization was confirmed by interphase cytogenetics with region-specific yeast artificial chromosomes to paraffin-embedded tumor tissue sections.

Adenocarcinoma, Clear Cell↗

PubMed1997

High-resolution comparative hybridization to combed DNA fibers.

Comparative genomic hybridization (CGH) has proven to be a comprehensive new tool to detect genetic imbalances in genomic DNA. However, the resolution of this method carried out on normal human metaphase spreads is limited to low copy number gains and losses of > or = 10 Mb. An improved resolution allowing the detection of copy number representations of single genes would strongly enhance the applicability of CGH as a diagnostic and research tool. This goal may be achieved when metaphase chromosomes are replaced by an array of target DNAs representing the genes of interest. To explore the feasibility of such a development in a model system we used cosmid MA2B3, which encompasses about 35 kb in the vicinity of exon 48 of the human dystrophin gene. Linearized cosmid fibers were attached to a glass surface and aligned in parallel by "molecular combing". Two-color fluorescence in situ suppression hybridization was performed on these cosmid fibers with probe mixtures containing different ratios (ranging from 1:2 to 4:1) of biotin- and digoxigenin-labeled MA2B3 cosmid DNAs. For each mixture fluorescence ratios were determined for 40-50 individual combed DNA molecules. In two series comprising a total of 651 molecules the median fluorescence ratio measurements revealed a linear relationship with the chosen probe ratios. Our study demonstrates that fluorescence ratio measurements on single DNA molecules can be performed successfully.

Biotin↗

PubMed1997

Comparative genomic hybridization analysis of human neuroblastomas: detection of distal 1p deletions and further molecular genetic characterization of neuroblastoma cell lines.

Deletions of the short arm of chromosome 1 and MYCN amplification are the most frequently encountered genetic changes in disseminated neuroblastomas and neuroblastoma cell lines. Different strategies have been followed for detection of these and other genomic changes in neuroblastoma including karyotyping, FISH, and LOH, each with its own limitations. Here we report upon the evaluation of comparative genomic hybridization (CGH) in the analysis of neuroblastoma cell lines, with the emphasis on the assessment of the reliability of CGH for the detection of distal 1p deletions. We have analyzed seven neuroblastoma cell lines for which the 1p status was previously studied in detail using FISH and LOH. Our results show that CGH allows reliable detection of distal 1p deletions, including a small interstitial deletion in cell line SK-N-AS. Furthermore, CGH also allows the detection of chromosomal imbalance which would otherwise remain undetected, and provides useful information for further molecular characterization of chromosomal imbalances.

Child, Preschool↗

PubMed1997

Sensitive and reliable detection of genomic imbalances in human neuroblastomas using comparative genomic hybridisation analysis.

Deletions of the short arm of chromosome 1, extra copies of chromosome 17q and MYCN amplification are the most frequently encountered genetic changes in neuroblastomas. Standard techniques for detection of one or more of these genetic changes are karyotyping, FISH analysis and LOH analysis by Southern blot or PCR. Each of these techniques has its own particular limitations. More recently, comparative genomic hybridisation (CGH) was introduced for detection of genomic imbalances including deletions, duplications and gene amplification. We evaluated the sensitivity and reliability of CGH for detection of the most frequently encountered genetic changes in neuroblastoma. For this purpose a panel of well-characterised neuroblastoma cell lines as well as a series of 11 primary neuroblastomas was analysed. Our results show that CGH is a valuable tool for the genetic characterisation of neuroblastomas, both for the detection of frequently occurring genomic imbalances and for the identification of previously unnoticed genetic changes.

Child, Preschool↗

PubMed1997

Ocular distribution of lomefloxacin 0.3% after a single instillation in the infected eye of pigmented rabbits.

We investigated the distribution of lomefloxacin, a fluoroquinolone, in the infected eye of pigmented rabbits after one instillation of 50 microliters lomefloxacin 0.3% eye drop, and compared tissue concentrations with therapeutic levels. Infection was induced by 6 instillations of Pseudomonas aeruginosa inoculum 6 x 10(5) bacteria) on centrally scratched cornea of 32 pigmented rabbits. Fifty microliters of 14[C] lomefloxacin 0.3% were instilled 24 hours after infection and animals were sacrificed 0.25, 0.5, 1, 2, 4, 8 and 12 hours later. Ocular structures, tear fluid, whole blood and plasma were then sampled, and tissue levels over time, Tmax, Cmax and area under the curve (AUC) were calculated. Lomefloxacin rapidly penetrated into the ocular structures: tear (Tmax 0.25 hours, Cmax 366 micrograms/ml, AUC 360 micrograms/ml x hour), corresponding value were for: eye lids (0.25, 7, 33), conjunctiva (0.25, 11, 7), cornea (0.25, 56, 70), aqueous humor (1, 8, 14), iris ciliary-body (4, 34, 252), lens (1, 0.2, 0.6). Tear levels remained high for many hours and were 34, 48, 1 and 27 micrograms/ml at 1, 2, 4 and 8 hours following a single instillation. Elimination from ocular structures was rapid. Therapeutic levels were achieved after a single instillation (mainly in the external ocular structures) when compared with MIC 90% values (1-10 micrograms/ml).

Administration, Topical↗

PubMed1996

Mapping human telomere regions with YAC and P1 clones: chromosome-specific markers for 27 telomeres including 149 STSs and 24 polymorphisms for 14 proterminal regions.

A YAC library enriched for telomere clones was constructed and screened for the human telomere-specific repeat sequence (TTAGGG). Altogether 196 TYAC library clones were studied: 189 new TYAC clones were isolated, 149 STSs were developed for 132 different TY-ACs, and 39 P1 clones were identified using 19 STSs from 16 of the TYACs. A combination of mapping methods including fluorescence in situ hybridization, somatic cell hybrid panels, clamped homogeneous electric fields, meiotic linkage, and BLASTN sequence analysis was utilized to characterize the resource. Forty-five of the TYACs map to 31 specific telomere regions. Twenty-four linkage markers were developed and mapped within 14 proterminal regions (12 telomeres and 2 terminal bands). The polymorphic markers include 12 microsatellites for 10 telomeres (1q, 2p, 6q, 7q, 10p, 10q, 13q, 14q, 18p, 22q) and the terminal bands of 11q and 12p. Twelve RFLP markers were identified and meiotically mapped to the telomeres of 2q, 7q, 8p, and 14q. Chromosome-specific STSs for 27 telomeres were identified from the 196 TYACs. More than 30,000 nucleotides derived from the TYAC vector-insert junction regions or from regions flanking TYAC microsatellites were compared to reported sequences using BLASTN. In addition to identifying homology with previously reported telomere sequences and human repeat elements, gene sequences and a number of ESTs were found to be highly homologous to the TYAC sequences. These genes include human coagulation factor V (F5), Weel protein tyrosine kinase (WEE1), neurotropic protein tyrosine kinase type 2 (NTRE2), glutathione S-transferase (GST1), and beta tubulin (TUBB). The TYAC/P1 resource, derivative STSs, and polymorphisms constitute an enabling resource to further studies of telomere structure and function and a means for physical and genetic map integration and closure.

Animals↗

PubMed1996

Comparative genomic hybridization imaging by the one-chip true-color CCD camera kappa CF 15 MC.

In comparative genomic hybridization (CGH), quantitative measurement of fluorescence intensity ratios on metaphase chromosomes is the basic method for detecting copy number changes in the test DNA. The microscope images are usually acquired by high-resolution, highly sensitive, black and white (B&W) CCD cameras. This requires subsequent recording of the different color images using appropriate filter combinations for excitation and emission. We describe an alternative approach using the one-chip true-color CCD camera Kappa CF 15 MC and an Omega triple-bandpass filter for simultaneous registration of the three dyes Texas red, FTTC, and DAPI. A detailed examination of the imaging properties of the system was performed. The camera response in the three color planes R, G, and B was evaluated, and calibration factors for image correction were calculated. An error estimate is given. A complete computer program for the image analysis of CGH experiments has been developed for an 80486 PC, using the commercially available software package Optimas as the basis for image recording. Examples that confirm the suitability of the system for ratio imaging in CGH are presented. The results were compared with others obtained from the same microscope slides using an established setup consisting of a B&W CCD camera (Photometrics) and a software program based on the TCL software package and run on a Macintosh Quadra 950. The results obtained using the two different systems were found to correspond closely.

Calibration↗

PubMed1996

Familial adenomatous polyposis: a submicroscopic deletion at the APC locus in a family with mentally normal patients.

Cytogenetically visible deletions that include the adenomatosis polyposis coli (APC) locus have repeatedly been reported in mentally handicapped polyposis patients. We report on a family with a submicroscopic deletion of about 200 kb including more than the 3' half of the APC gene and the adjacent DP1 gene. The deletion was detected by linkage analysis with flanking and intragenic markers and proven by in situ hybridisation with intragenic cosmid clones. All the familial adenomatous polyposis (FAP) patients and persons at risk in the family show normal behaviour and intelligence. Thus, it is conceivable that at least some of the FAP patients in whom mutations could not be identified by routine methods may have large but submicroscopic deletions.

Adenomatous Polyposis Coli↗

PubMed1996

Detection of a germline mutation and somatic homozygous loss of the von Hippel-Lindau tumor-suppressor gene in a family with a de novo mutation. A combined genetic study, including cytogenetics, PCR/SSCP, FISH, and CGH.

von Hippel-Lindau (VHL) disease is a pleiotropic disorder featuring a variety of malignant and benign tumors of the eye, central nervous system, kidney, and adrenal gland. Recently the VHL gene has been identified in the chromosomal region 3p25-26. Prognosis and successful management of VHL patients and their descendants depend on unambiguous diagnosis. Due to recurrent hemangioblastomas, a29-year-old patient without familial history of VHL disease was diagnosed to be at risk for the disease. Histopathological examination of a small renal mass identified a clear cell tumor with a G1 grading. Genetic characterization of the germline and of the renal tumor was performed. Polymerase chain reaction/single strand conformation polymorphism (PCR/SSCP) analysis with primers from the VHL gene identified a deletion of a single nucleotide in exon 2 in the patient's germline and in the tumor, but not in the DNA of his parents. This deletion therefore must be a de novo mutation. Comparative genome hybridization (CGH) and fluorescence in situ hybridization (FISH) analysis of the G1 tumor with differentially labelled yeast artifical chromosome (YAC) clones showed loss of 3p and of the 3p26 signals, respectively. In conclusion, we identified a de novo germline mutation in the VHL gene of a young patient and a somatic chromosome 3p loss at the homologous chromosome 3 in his renal tumor. Our results suggest a recessive mode of inactivation of the VHL gene, providing solid evidence for its tumor-suppressor gene characteristics. Our data show the diagnostic potential of genetic testing, especially in patients without VHL family history. Furthermore, the findings of homozygous inactivation of the VHL gene in a G1 tumor support the notion that the inactivation of the VHL gene is an early event in tumorigenesis of renal cell carcinoma.

Adult↗

PubMed1996

Nuclear architecture and the induction of chromosomal aberrations.

Progress in fluorescence in situ hybridization, three dimensional microscopy and image analysis has provided the means to study the three-dimensional structure and distribution of chromosome territories within the cell nucleus. In this contribution, we summarize the present state of knowledge of the territorial organization of interphase chromosomes and their topological relationships with other macromolecular domains in the human cell nucleus, and present data from computer simulations of chromosome territory distributions. On this basis, we discuss models of chromosome territory and nuclear architecture and topological consequences for the formation of chromosome exchanges.

Animals↗

PubMed1996

A SPGY copy homologous to the mouse gene Dazla and the Drosophila gene boule is autosomal and expressed only in the human male gonad.

We have isolated a series of human testis poly(A) cDNA clones by cross-hybridization to SPGY1, a Y gene homologous to DAZ. Their sequence analysis revealed an identical nucleotide composition in different 'full-length' clones, suggesting that all were encoded by the same gene. We mapped this gene to the short arm of chromosome 3 and designated it SPGYLA (SPGY like autosomal). Comparison of the SPGYLA cDNA sequence with the cDNA sequences of DAZ and SPGY1 revealed two prominent differences. The tandem repetitive structure of 72 bp sequence units (DAZ repeats) is absent. SPGYLA contains only one 72 bp sequence unit. Downstream of it, a specific 130 bp sequence domain is present which is absent in DAZ and SPGY1 but present in the mouse gene Dazla and in the Drosophila gene boule. SPGYLA encodes an RNA binding protein expressed only in the human male gonad. The data presented give strong evidence that not DAZ but SPGYLA is the functional human homologue of Dazla and boule.

Amino Acid Sequence↗

PubMed1996

Topical lomefloxacin twice daily compared with fucidic acid in acute bacterial conjunctivitis.

Forty-five patients with presumed acute bacterial conjunctivitis were treated in an investigator-masked randomized multicenter study with either lomefloxacin 0.3% or fucidic acid 1% eye drops twice daily. Clinical signs and symptoms were rated by slit-lamp examination and conjunctival swab cultures were performed to evaluate clinical and microbiological efficacy. A total of 57 ocular isolates were tested for susceptibility to nine antibiotics. A significant decrease in clinical symptomatology was achieved by both treatments with a gradual improvement over the treatment period of 7-9 days. Bacteriological recovery was frequently achieved already at the first control visit (day 3-5), but the recovery rate was statistically significant (p = 0.014) only in the lomefloxacin group. The relatively high in vitro resistance rate (46%) to fucidic acid was not reflected by lower clinical efficacy. Two unrelated adverse events (one in each treatment group) and minimal local intolerance problems were observed in both treatment groups. A significantly higher incidence of burning sensation was observed with fucidic acid than with lomefloxacin (p < 0.01). All four treatment failures in the study occurred in the fucidic acid group. Lomefloxacin 0.3% ophthalmic solution demonstrated a high efficacy and good tolerance in the management of acute bacterial conjunctivitis.

Acute Disease↗

PubMed1996

A 3 1/2 year old girl with distal trisomy 19q defined by FISH.

A 3 1/2 year old girl was evaluated because of developmental delay. Short stature was evident with height between the 3rd and 10th centiles, while weight and head circumference were on the 50th centile. Dysmorphic features consisted of a high bossed forehead, pointed short ear lobes, small nose, bilateral convergent strabismus, left simian crease, a gap between the first and second toes bilaterally, mild clinodactyly, and a broad, barrel shaped thorax. Cytogenetic investigations showed an unbalanced karyotype, 46,XX,10q+, which was de novo in origin. Fluorescence in situ hybridisation (FISH) using three library probes (from chromosomes 10, 19, and 19q) and a YAC probe (from 10q telomere) showed that the additional material on 10q was derived from chromosome 19q. The patient had an unbalanced translocation, 46,XX,-10,+der(10)t(10;19)(q26.3; q13.3), which resulted in distal trisomy 19q. Few other cases of proven distal trisomy 19q are available for comparison of clinical features.

Child↗