PubMed Health⌕ Search

Biomedical subjects

H van Dekken

Publications and source records attributed to H van Dekken.

62 records · Page 4Linked to original sources
PubMed1989

Detection of host cells following sex-mismatched bone marrow transplantation by fluorescent in situ hybridization with a Y-chromosome specific probe.

Fluorescent in situ hybridization (FISH) with a biotinylated Y-chromosome specific repetitive DNA probe was applied to detect Y-bearing cells in blood and bone marrow samples from patients with hemopoietic malignancies after a sex-mismatched bone marrow transplantation. The sensitivity of this method is in the order of 0.1% Y-bearing nuclei in male recipients transplanted with female marrow. In female recipients of male marrow, the detection of low numbers of non-Y-bearing nuclei is less sensitive. The presence of host cells in blood and bone marrow of seven patients (four males, three females) was investigated with respect to successful engraftment or recurrence of the disease. The results obtained were compared with cytology (all seven cases) and with conventional cytogenetics (five cases). In five patients, the results of Y-FISH and cytology were identical. In two patients, low numbers of male host cells were detected in the marrow by Y-FISH, whereas cytology indicated complete remission of the disease. In three patients Y-FISH and cytogenetic data were similar, but in two patients Y-FISH revealed the presence of 0.2% and 7% male host cells, respectively, in bone marrow, whereas cytogenetics indicated a 100% female marrow in both cases. Because the hybridization was performed in situ, the morphology of the nuclei was preserved. To differentiate between normal and leukemic cells, the size of the blast cell nuclei appeared to be a very useful indicator. Our data suggest that fluorescent in situ hybridization with a Y-chromosome specific probe is a fast and sensitive technique to identify the host cells after sex-mismatched bone marrow transplantation, in particular in case of male recipient and female donor combinations.

Bone Marrow Transplantation↗
PubMed1988

Fluorescence in situ hybridization to interphase cell nuclei in suspension allows flow cytometric analysis of chromosome content and microscopic analysis of nuclear organization.

Fluorescence hybridization to interphase nuclei in liquid suspension allows quantification of chromosome-specific DNA sequences using flow cytometry and the analysis of the three-dimensional positions of these sequences in the nucleus using fluorescence microscopy. The three-dimensional structure of nuclei is substantially intact after fluorescence hybridization in suspension, permitting the study of nuclear organization by optical sectioning. Images of the distribution of probe and total DNA fluorescence within a nucleus are collected at several focal planes by quantitative fluorescence microscopy and image processing. These images can be used to reconstruct the three-dimensional organization of the target sequences in the nucleus. We demonstrate here the simultaneous localization of two human chromosomes in an interphase nucleus using two probe labeling schemes (AAF and biotin). Alternatively, dual-beam flow cytometry is used to quantify the amount of bound probe and total DNA content. We demonstrate that the intensity of probe-linked fluorescence following hybridization is proportional to the amount of target DNA over a 100-fold range in target content. This was shown using four human/hamster somatic cell hybrids carrying different numbers of human chromosomes and diploid and tetraploid human cell lines hybridized with human genomic DNA. We also show that populations of male, female, and XYY nuclei can be discriminated by measuring their fluorescence intensity following hybridization with a Y-chromosome-specific repetitive probe. The delay in the increase in Y-specific fluorescence until the end of S-phase in consistent with the results recorded in previous studies indicating that these sequences are among the last to replicate in the genome. A chromosome-17-specific repetitive probe is used to demonstrate that target sequences as small as one megabase (Mb) can be detected using fluorescence hybridization and flow cytometry.(ABSTRACT TRUNCATED AT 250 WORDS)

Cell Line↗
PubMed1988

Enzymatic production of single-stranded DNA as a target for fluorescence in situ hybridization.

This study demonstrates that Exonuclease III (Exo III) can be used to produce sufficient single-stranded (ss)DNA in chromosomes and cells to allow in situ hybridization. In this study, all of the probes were modified with biotin and the probe binding was visualized with fluorescein-labeled avidin. Exo III digestion starting at naturally occurring breaks in methanol-acetic acid preparations produced enough ssDNA for strong hybridization when human genomic DNA was used to probe human chromosomes. Pretreatment with the endonucleases EcoRI, Hind III and BamHI was used to produce more sites for initiation of Exo III digestion when using a chromosome-specific repetitive probe specific to a small chromosomal subregion near the telomere of human chromosome 1(1p36). The fluorescence intensity following hybridization to Exo III-treated targets was roughly equal to that following hybridization to thermally denatured targets, but background fluorescence was lower.

Animals↗
PubMed1988

A new application of in situ hybridization: detection of numerical and structural chromosome aberrations with a combination centromeric-telomeric DNA probe.

Fluorescent in situ hybridization provides a fast method for detection of specific nucleic acid sequences. We have used high-resolution, single-color fluorescent in situ hybridization with a combination centromeric-telomeric DNA probe, specific for chromosome 1, to investigate the feasibility of simultaneous assessment of numerical and structural chromosome aberrations. The K562 leukemia cell line served as a model.

Centromere↗
PubMed1981

Linear relations between proton current and pH gradient in bacteriorhodopsin liposomes.

The dependence of proton movement across the membrane of bacteriorhodopsin liposomes on the pH gradient was investigated. Under the appropriate experimental conditions, endogenous proton (or hydroxyl) leakage, proton movement catalyzed by protonophore or nigericin, and light-driven proton translocation depend linearly on the pH gradient. This justifies the use of linear proton flux vs. protonmotive force relations in a recent mosaic thermodynamic description of ion translocation in bacteriorhodopsin liposomes [Westerhoff, H. V., Scholte, B. J., & Hellingwerf, K. J. (1979) Biochim. Biophys. Acta 547, 544-560]. Since bacteriorhodopsin liposomes are a model system for all biological energy transducing systems in which proton pumps are involved, these findings also explain linear relations between proton flux and protonmotive force observed in and postulated for those systems. In cases where the membrane potential is not clamped at a low value, an initial phase of rapid proton movement occurs, followed by a phase of slower proton movement. The rate of proton movement during the slow phase is again linear with the pH gradient. Such a linear relation is not observed for the fast phase. Since the rapid proton movement phase is also observed in liposomes without bacteriorhodopsin, it is not due (only) to dissociation of scalar protons from bacteriorhodopsin. We suggest that during the initial phase of proton movement, the proton flux is not yet electrically compensated by the fluxes of other ions.

Bacteriorhodopsins↗
PubMedDate not supplied

Interphase cytogenetics and comparative genomic hybridization of human epithelial cancers and precursor lesions.

The accuracy of cytogenetic analyses of human solid cancers has improved enormously over the past decade by the introduction and refinement of DNA in situ hybridization (ISH) techniques. This methodology can be applied to cells in the interphase state, thereby making it an excellent tool for the delineation of chromosomal aberrations in solid tumors. The use of non-isotopic ISH to intact and disaggregated cancer specimens will be discussed, as well as comparative genomic hybridization (CGH) with tumor-derived DNAs. In this review we will focus on hybridocytochemical interphase approaches for the detection of chromosomal changes in frequently occurring human epithelial malignancies, e.g., breast, lung, and prostate carcinomas. We will further discuss the use of ISH procedures for the genetic analysis of precursor conditions leading to invasive carcinomas. Knowledge concerning these precancerous conditions is increasing, and its importance in cancer prevention has been recognized. Interphase cytogenetics by ISH, as well as CGH, with DNAs derived from microdissected, precancerous, dysplastic tissue areas will increase our understanding of these lesions, both at the investigative and diagnostic levels.

Humans↗
PubMedDate not supplied

Involvement of cancer-activating genes on chromosomes 7 and 8 in esophageal (Barrett's) and gastric cardia adenocarcinoma.

UNLABELLED: The incidence of adenocarcinomas of the distal esophagus (Barrett's esophagus) and proximal stomach (gastric cardia) has increased rapidly over the past decades. In contrast to this dramatic increase, genetic knowledge is sparse. MATERIALS AND METHODS: We investigated genomic amplification on chromosomes 7 and 8 by comparative genomic hybridization (CGH) and protein expression of relevant oncogenes (EGFR, HGF, MET, CTSB, MYC) by immunohistochemistry (IHC) in 22 esophageal and 22 gastric cardia carcinomas. RESULTS: The CGH and IHC patterns were very similar for the two cancer locations. IHC showed positive immunostaining in 93% of the adenocarcinomas for at least one of the investigated genes, whereas CGH disclosed genomic gains on chromosome 7 and/or 8 in 80%. CONCLUSION: Cancer-activating genes on chromosomes 7 and 8 are frequently involved in gastro-esophageal junction adenocarcinomas. Moreover, the similarities in chromosomal changes and protein expression patterns strongly suggest that esophageal and gastric cardia adenocarcinomas have a shared etiology. This is in agreement with studies addressing gastroesophageal reflux disease and intestinal metaplasia at these locations.

Adenocarcinoma↗