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PubMed2006

In vivo experimentation with simian herpesviruses: assessment of biosafety and molecular contamination.

In vivo studies with highly pathogenic viruses prompt concerns regarding the persistence of infectious virus in pathology specimens. Although formalin fixation of tissues may inactivate infectious virus, fixation may also degrade viral nucleic acid and antigens, thereby limiting detection of virus in tissues by polymerase chain reaction (PCR) amplification or immunohistochemistry (IHC). We sought to: 1) assess the rate of inactivation of infectious virus in tissue specimens during formalin fixation, 2) assess IHC recognition of viral antigens and PCR detection of viral DNA after long-term (14 d) formalin fixation, and 3) investigate microtome contamination by DNA carry-over to subsequently sectioned tissues. Infectious baboon herpesvirus HVP2 could be recovered from fresh tissues of infected mice but not those fixed in formalin for >/=24 h. The intensity of IHC staining of viral antigen was unaffected by the duration of formalin fixation. PCR detection of viral DNA was negatively impacted by formalin fixation and/or heat inherent to paraffin processing; however, amplification of very short DNA sequences using real-time PCR was not affected. Lastly, microtome contamination by viral DNA was demonstrated by PCR screening of uninoculated control tissues that were sectioned after sectioning infected tissues. In summary, infectious virus is inactivated after only 24 h of formalin fixation whereas IHC staining remains sensitive in tissues fixed for up to 14 d. Formalin fixation does degrade DNA, but viral DNA can be detected by PCR amplification of very short DNA sequences. In addition, viral DNA can contaminate a microtome knife such that subsequently sectioned uninoculated control tissues exhibit false positive PCR amplification.

Animals↗

PubMed1993

Identification of Helicobacter pylori DNA in the mouths and stomachs of patients with gastritis using PCR.

AIMS: To determine the prevalence of Helicobacter pylori colonisation in the mouths of patients with H pylori gastritis. METHODS: A nested polymerase chain reaction test for the 16S ribosomal RNA gene of H pylori was used on saliva, dental plaque, gastric juice and gastric biopsy specimens from patients attending a dyspepsia clinic. RESULTS: Thirteen patients had histologically confirmed Helicobacter associated gastritis. Twelve of these had positive gastric aspirates by PCR. Five had at least one positive oral specimen. Eight patients with normal gastric biopsy specimens had no PCR positive oral specimens or gastric aspirates. All, however, had PCR positive gastric biopsy specimens. In an attempt to determine the origin of these positive results in normal patients, it was shown that biopsy forceps could contaminate specimens with DNA from previous patients. CONCLUSION: The demonstration of the organism in the mouths of a substantial proportion of dyspeptic patients has major implications for the spread of H pylori and identifies a potential source for reinfection following eradication of the organism from the stomach.

Base Sequence↗

PubMed1991

[Results and contributing prospects of molecular probes and genetic amplification in vitro (PCR) in toxoplasmosis].

Toxoplasmosis is one of the latest parasitic diseases to have benefited from molecular biological study (1989). To our knowledge we were one of the first to have cloned several DNA probes using genomic DNA from Toxoplasma gondii. One of these probes, TGR1E, has been sequenced and has enabled the selection and chemical synthesis of 4 oligonucleotides (22 to 25 nucleotides respectively) for use in the Polymerase Chain reaction (PCR). Completely specific for Toxoplasma gondii, they confer remarkable sensitivity allowing detection of quantities of DNA as small as 2 fg (f = 10(-15) g) corresponding to less than 1/50th of the DNA contents in a single tachyzoïte. The method is currently being applied using the in situ hybridization technique. One hundred samples (sera, CSF, broncho-alveolar washings, biopsies), mostly from immunocompromised patients, have been studied by the Southern-blot method. The results are still preliminary but appear very encouraging, especially since serological diagnostic studies during acquired or post-therapeutic immunodeficiencies (transplants) are usually impossible. Nevertheless, as it has already been reported in various other applications, the risk of false positive results requires that PCR be performed with highly rigorous technique, particularly in order to avoid any contamination by foreign DNA. An analysis of restriction profiles by the Southern method has also been carried out in 6 different strains of Toxoplasma gondii. Although a certain number of DNA fragments are common to all strains, some fractions of greater than 1.6 kb could characterize certain isolates. This protocol which is still preliminary is currently in progress and will be carried out in a larger number of cloned strains.(ABSTRACT TRUNCATED AT 250 WORDS)

Base Sequence↗

PubMed1998

Tympano-ossicular allografts and HIV transmission.

OBJECTIVE: To evaluate the potential risk of human immunodeficiency virus (HIV) transmission by tympano-ossicular allografts by studying the efficacy of standard preservation techniques to eliminate the presence of proviral HIV-1 DNA fragments in contaminated ossicles. STUDY DESIGN: Randomized single-blind prospective study on the ossicles of HIV-1 patients. MATERIAL: Ossicles of five patients who had died of acquired immune deficiency syndrome (AIDS) (HIV-1 infection) were taken within 6 hours postmortem and allocated randomly to a treatment and nontreatment group. Liver and skin biopsies were taken as positive control specimens. PROCESSING: The treatment group was processed with standard techniques (formaldehyde) for tympano-ossicular allograft preservation and the nontreatment group was only washed, dried, and stored in sterile tubes at -700 degrees without further processing. MAIN OUTCOME MEASURE: Proviral HIV-1 DNA was detected using polymerase chain reaction amplification techniques. RESULTS: No proviral HIV-1 DNA was detected in any of the treated ossicles, whereas three of five sets of untreated ossicles were positive. The positive control specimens of all treated and nontreated sets were positive for proviral HIV-1 DNA. CONCLUSIONS: These results suggest that the preservation technique for tympano-ossicular allografts is safe with regard to HIV-1 transmission.

DNA, Viral↗

PubMed2004

The use of degenerate-primed random amplification of polymorphic DNA (DP-RAPD) for strain-typing and inferring the genetic similarity among closely related viruses.

Often it is necessary to distinguish among strains of closely related viruses, as well as infer the genetic relatedness within large groups of viruses. Current methods for strain-typing viruses are time-consuming, require significant quantities of extracted DNA, and/or may require a priori genetic information. In this study we modified random amplification of polymorphic DNA (RAPD) by using a degenerate primer to produce unique and reproducible banding patterns from viral genomes. In the degenerate-primed RAPD analysis (DP-RAPD), a selection of algal virus and bacteriophage strains were profiled that encompassed an array of genome sizes and virus families. Closely related viruses (e.g. strains infecting Micromonas pusilla) generated similar, yet unique DP-RAPD patterns that could be readily distinguished from viruses within the same family (Phycodnaviridae) infecting a Chlorella-like alga. As well, marine vibriophage from the families Myoviridae, Siphoviridae, and Podoviridae showed high diversity and were distinct from coliphage and cyanophage. Contamination of host DNA, even at levels above those that would normally be encountered, did not interfere with the viral patterns. These findings describe a rapid, PCR-based tool for strain-typing viral isolates that allows inferences to be made on genetic relatedness within groups of closely related viruses.

Caudovirales↗

PubMedDate not supplied

PCR with Paracoccidioides brasiliensis specific primers: potential use in ecological studies.

The precise microenvironment of Paracoccidioides brasiliensis has not yet been discovered perhaps because the methods used are not sensitive enough. We applied to this purpose the polymerase chain reaction (PCR) using three sets of specific primers corresponding to two P. brasiliensis genes. This fungus as well as several other fungi, were grown and their DNA obtained by mechanical disruption and a phenol chloroform isoamylalcohol-based purification method. The DNA served for a PCR reaction that employed specific primers from two P. brasiliensis genes that codify for antigenic proteins, namely, the 27 kDa and the 43 kDa. The lowest detection range for the 27 kDa gene was 3 pg. The amplification for both genes was positive only with DNA from P. brasiliensis; additionally, the mRNA for the 27 kDa gene was present only in P. brasiliensis, as indicated by the Northern analysis. The standardization of PCR technology permitted the amplification of P. brasiliensis DNA in artificially contaminated soils and in tissues of armadillos naturally infected with the fungus. These results indicate that PCR technology could play an important role in the search for P. brasiliensis' habitat and could also be used in other ecological studies.

Animals↗

PubMed2004

Measurement of relative copy number of CDKN2A/ARF and CDKN2B in bladder cancer by real-time quantitative PCR and multiplex ligation-dependent probe amplification.

Many tumors have large homozygous deletions of the CDKN2A locus (encoding p14(ARF) and p16) and of CDKN2B (p15). Our aim was to determine which gene is the major target in bladder cancer. We used quantitative real-time PCR (RTQ-PCR) to determine copy number of p15, of p14(ARF) exon 1beta, and p16 exon 2 in 22 tumor cell lines and 83 bladder tumors, some of which had been assessed previously by duplex PCR. Titration experiments showed that homozygous deletion could be detected in the presence of up to 30% normal DNA. Results for cell lines were compatible with previous cytogenetic analyses. Ten cell lines and 32 tumors (38.5%) had homozygous deletion of at least one target. Thirteen tumors (15.7%) had deletion of all three targets. Two tumors had deletion of p14(ARF) exon 1beta alone and four of p16 exon 2 alone. RTQ-PCR detected more homozygous deletions than duplex PCR. Finally we used a multiplex ligation-dependent probe amplification kit to provide independent confirmation of results. We conclude that with appropriate controls RTQ-PCR is a sensitive and robust method to detect copy number changes in tumors even in the presence of contaminating normal cell DNA.

Cell Cycle Proteins↗

PubMed2000

An outbreak of febrile gastroenteritis associated with corn contaminated by Listeria monocytogenes.

BACKGROUND: On May 21, 1997, numerous cases of febrile gastrointestinal illness were reported among the students and staff of two primary schools in northern Italy, all of whom had eaten at cafeterias served by the same caterer. METHODS: We interviewed people who ate at the cafeterias about symptoms and foods consumed on May 20. There were no samples of foods left at the cafeterias, but we tested routine samples taken on May 20 by the caterer and environmental specimens at the catering plant. The hospitalized patients were tested for common enteropathogens and toxins. RESULTS: Of the 2189 persons interviewed (82 percent of those exposed), 1566 (72 percent) reported symptoms; of these, 292 (19 percent) were hospitalized. Among samples obtained from hospitalized patients, all but two of the stool specimens and all blood specimens were negative for common enteropathogens. Listeria monocytogenes was isolated from one blood specimen and from 123 of the 141 stool specimens. Consumption of a cold salad of corn and tuna was associated with the development of symptoms (relative risk, 6.19; 95 percent confidence interval, 4.81 to 7.98; P<0.001). L. monocytogenes was isolated from the caterer's sample of the salad and from environmental specimens collected from the catering plant. All listeria isolates were serotype 4b and were found to be identical on DNA analysis. Experimental contamination of sterile samples of the implicated foods showed that L. monocytogenes grew on corn when kept for at least 10 hours at 25 degrees C. CONCLUSIONS: Food-borne infection with L. monocytogenes can cause febrile illness with gastroenteritis in immunocompetent persons.

Adult↗

PubMed1992

Omeprazole does not cause unscheduled DNA synthesis in rabbit parietal cells in vitro.

Parietal cells from rabbit gastric mucosa, enriched to greater than 90% purity, were used to study the effect of the H+,K(+)-ATPase inhibitor omeprazole on DNA in vitro. In this preparation, omeprazole undergoes acid-catalyzed conversion to its active form, the sulfenamide, which subsequently binds to luminal SH groups of the H+,K(+)-ATPase and thereby inhibits acid secretion. In the parietal cell fraction the S-phase inhibitor hydroxyurea (HU) decreased [3H]thymidine uptake by 40% as measured by liquid scintillation counting (LSC), presumably due to inhibition of scheduled DNA synthesis in contaminating stem cells. In the presence of HU, irradiation with ultraviolet light (UV) or treatment with the gastric carcinogen, 1-methyl-3-nitro-1-nitrosoguanidine (MNNG) increased [3H]thymidine uptake by a factor of 5. Autoradiography of isolated, stimulated parietal cells showed that UV irradiation and MNNG treatment increased the average number of silver grains over the nuclei 18-fold and 4-fold, respectively. In contrast, treatment of histamine-stimulated parietal cells with omeprazole or ranitidine in concentrations 100 times the IC50 value for inhibition of acid secretion in the parietal cells did not increase [3H]thymidine incorporation above the control levels, measured either by LSC or by autoradiography. Extracted DNA from stimulated parietal cells treated with [3H]omeprazole or [3H]MNNG showed no binding of [3H]omeprazole but considerable binding of [3H]MNNG. It is concluded that parietal cells can undergo DNA repair, but there is no indication that omeprazole, or its acid-derived metabolites, should cause any damage to DNA, nor does it bind to DNA in its target cell, where the highest concentrations of omeprazole and its acid-derived products are found.

Animals↗

PubMed1980

A characterization of mitochondrial and mycoplasmal DNAs associated with cloned HeLa thymidine kinase minus cells.

HeLa S3 cells were cloned, recloned, and then selected for growth in the presence of increasing concentrations of bromodeoxyuridine. Cultures of these cloned thymidine kinase minus (TK-) cells were found to harbor mycoplasma which sedimented with mitochondria in sucrose density step gradients. Examination of mitochondrial DNA (mitDNA) components by restriction enzyme analysis and electron microscopy revealed no gross alterations in size, sequence arrangements, or replicative forms compared with mitDNA of HeLa S3 cells. Restriction enzyme cleavage sites for BamHI (one site), PstI (two sites) and HpaI (three sites) were mapped on this genome relative to the three cleavage sites for each of EcoRI and HindIII, respectively. Analysis of topological complexity revealed similar frequencies of catenated mitDNA molecules in both cloned TK- (22.5 +/- 1.5% of mass) and HeLa S3 cells )25.6 +/- 1.5% of mass). Unicircular dimers comprise 6.7 +/- 0.9% of the mitDNA mass in cloned TK- cells but were not detected in HeLa S3 mitDNA. Examination of the mycoplasmal contaminant of mitochondrial DNA after digestion with various restriction enzymes and agarose gel electrophoresis revealed that most of the DNA was distributed in discretely sized fragments in patterns that can probably be used to unambiguously identify and classify the organism.

Bromodeoxyuridine↗

PubMed2002

[Microsatellite analysis of the 3p13-p25 region in renal cell carcinoma in humans].

INTRODUCTION & OBJECTIVES: Interstitial and terminal deletions of different regions of the chromosome 3 have been associated with the development of human nonpapillary renal cell carcinomas. We performed a microsatellite analysis at the region 3p13-p25 to study the role of the short arm of chromosome 3 in the pathogenesis of Renal Cell Carcinomas. MATERIAL & METHODS: Renal tumor specimens and normal kidney tissue from 57 patients were obtained after radical nephrectomy and immediately snap-frozen. Blood samples were also obtained from each patient, immediately processsed and used as normal DNA. To detect allelic loss, we used 8 microsatellite markers covering the region 3p13-p25. Genetic alterations have been correlated with histology, nuclear grade, pathological stage and stromal cell infiltration. RESULTS: A total of 41 cases (71.9%) were clear cell renal cell carcinomas (CCRCC), 7 (12.3%) were chromophobe renal cell carcinomas, 5 (8.8%) were papillary renal cell carcinomas, and 4 (7%) oncocytic tumors. Microsatellite analysis showed loss of heterozigosity (LOH) in 73.2% of the CCRCCs, and in none of the remaining histologic types. Terminal deletions were detected in 53.3% of the nonpapillary RCCs with LOH, and the remaining nonpapillary RCCs showed multiple interstitial deletions (46.6%). A common region of deletion in 3p14.2 has been observed. Due to contamination with normal DNA, when stromal cell infiltration increases, less losses of heterozigosity are detected. We did not find a correlation between LOH at 3p and the nuclear grade, nor between LOH at 3p and the pathological stage. CONCLUSIONS: 1. Microsatellite analysis of LOH at 3p can be used for the differential diagnosis of renal tumors. 2. The evidence of multiple interstitial deletions in a great number of nonpapillary RCCs suggests that more than one gene should be involved in the development of nonpapillary RCC, and already present in early stages of oncogenesis. 3. The common region of deletion 3p14.2 suggests the presence of unstable sequences of DNA that play an important role in the pathogenesis of nonpapillary RCC. 4. LOH at 3p in most nonpapillary RCCs irrespective of the grade and stage, proves that these molecular alterations do not mark a more aggressive behaviour of the tumor.

Carcinoma, Renal Cell↗

PubMed1987

Nuclear endo-exonuclease of Neurospora crassa. Evidence for a role in DNA repair.

The major nuclease activity in nuclei of mycelia of Neurospora crassa has been identified as that of endoexonuclease, an enzyme purified and characterized previously from mitochondria and vacuoles which acts endonucleolytically on single-stranded DNA and RNA and possesses highly processive exonuclease activity with double-stranded DNA. Cross-contamination from the other organelles was eliminated as a source of the activity. Endo-exonuclease of nucleoplasm, chromatin, and nuclear matrix showed 80-100% cross-reaction with antisera raised to purified extranuclear endoexonuclease and was also strongly inhibited by 20 microM aurin tricarboxylic acid. In addition, it yielded some of the same-sized polypeptides on activity gel analysis. Nuclei also contained immunochemically cross-reactive trypsin-activable endo-exonuclease activity, a form of enzyme that was shown previously to occur in high amounts in the cytosol and in a tightly bound form associated with the mitochondrial inner membrane. Pretreatment of wild-type mycelia for 1 h with 4-16 micrograms/ml the DNA-damaging agent, 4-nitroquinoline-1-oxide (4-NQO), which caused about 50-80% growth inhibition, resulted in a dose-dependent loss of up to 80% of inactive endo-exonuclease from nuclei. At low doses of 4-NQO, this was accompanied by increases in the level of active enzyme. Nuclei of the DNA repair-deficient uvs-3 mutant were found to contain only 12% of the active enzyme and about 32% of inactive enzyme as that in wild-type nuclei. Mycelial growth of this mutant was 10 times more sensitive to 4-NQO than the wild-type. At a dose which resulted in equivalent growth inhibition, 4-NQO had no effect on the level of active endo-exonuclease in uvs-3 nuclei and caused an increase (over 30%) in the level of inactive enzyme. These data are consistent with a role of endo-exonuclease in the repair of nuclear DNA.

4-Nitroquinoline-1-oxide↗

PubMed1996

Diagnosis of Neospora caninum and Toxoplasma gondii infection by PCR and DNA hybridization immunoassay.

A recently described PCR test for the identification of Neospora caninum and Toxoplasma gondii has been further developed and optimized in view of its practicability for routine diagnostic application. The N. caninum-specific PCR was adapted to the diagnostic operating standard of the T. gondii-specific PCR in that the uracil DNA glycosidase system was introduced, which eliminates potential carry-over contaminations of amplified target DNA from previous reactions. Furthermore, both PCR tests were optimized by including a DNA hybridization immunoassay based on the use of the commercially available Gen-eti-k DEIA kit. This assay allowed highly sensitive and specific detection of respective DNA amplification products and thus substantially facilitated the reading and interpretation of the test results.

Animals↗

PubMed1985

Rapid large-scale purification of plasmid DNA by medium or low pressure gel filtration. Application: construction of thermoamplifiable expression vectors.

This paper describes a new method of plasmid DNA purification which is fast and reliable enough for most purposes in recombinant DNA technology. The present method does not require the use of toxic chemicals such as phenol or ethidium bromide, costly ultracentrifugation procedures or other processes which can modify the supercoiled structure of the plasmids, such as adsorption on glass fiber. This method is based on the principle of gel filtration chromatography, at low pressure (1 bar) or medium pressure (between 5 and 10 bars), using Sephacryl S1000 or Superose 6B. It permits recovery of plasmids: in preparative quantities (from 300 micrograms to 4 mg), exempt from RNA, DNA and protein contamination, and suitable for various common genetic engineering procedures immediately after purification. To test the reliability of the technique as well as the degree of purification, the plasmids were used to construct thermoamplifiable vectors, carrying the lacUV5 promoter and the 5' end of the beta-galactosidase gene with a single EcoR1 site in each of the three possible translational phases. This set of vectors is designed for the expression of foreign genes as hybrid proteins in Escherichia coli.

Chromatography, Gel↗

PubMed1995

[Usefulness of genome analysis methods for diagnosis of giardiasis and cryptosporidiosis].

The article comprises a critical review on practical applications of molecular technology in parasitological diagnostics in a broad sense, also as a diagnosis of species and a method of epidemiological analysis. Techniques of genome analysis at different levels, as specific nucleic acid probes, DNA restriction profiles (RFLP), hybridization techniques, pulse-field gel electrophoresis, in vitro nucleic acid amplification, and DNA fingerprint technique used in studies on Giardia and Cryptosporidium were discussed. The essential reservation as far as this technology is concerned refers to its usefulness in parasitological diagnostics; there is no sense in working out methods for recognizing parasites which could otherwise be identified by well trained parasitologists and simple microscopic methods. The improved diagnosis of parasites resulting from the application of molecular technology significantly contributed to the armarium of parasitologists. Application of recent molecular technology in diagnosis of giardiasis and cryptosporidiosis may basically support clinical diagnosis which provides possibilities of early and selective treatment and makes possible epidemiological studies. These assays will permit not only a rapid diagnosis and exact differentiation but will also enable a better recognition of Giardia and Cryptosporidium genome organization. However, in spite of the wide availability of this new techniques they have not been fully applied--as yet--in diagnosis and in epidemiological studies on these parasites. The authors share the opinion of Busch (1991) on the need of proper recognition of high-quality and rigorous work in employing new molecular assays, because their wide availability and high sensitivity could cause "false-positive" results by contamination with amplified DNA sequences.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1966

Extraction of nucleic acids from lyophilized plant material.

Four methods for extracting nucleic acids from lyophilized cotton (Gossypium hirsutum L. cv. Stoneville 62) leaves and roots were compared. They were based on the use of: (I) HC10(4); (II) KOH; (III) a mixture of 90% phenol, Tris (hydroxymethyl) aminomethane buffer, and sodium lauryl sulfate; and (IV) NaCl. (I) extracted large amounts of RNA but little DNA and extracted much carbohydrate and protein contaminants. (II) gave a good yield of both RNA and DNA but extracted such large amounts of contaminating material that purification of RNA on an anion exchange column was necessary. (III) extracted only part of the RNA and practically no DNA, but extracted contaminating materials. (IV) resulted in high yields of both RNA and DNA when modified to omit preliminary acid extraction of impurities. The use of cold trichloroacetic acid instead of ethanol, to precipitate NaCl-extracted nucleic acids, separated the nucleic acids from most of the carbohydrate and acid-soluble phosphate contaminants and resulted in good agreement among results by ultraviolet absorbance, pentose tests, and phosphate analysis. This method also resulted in lower protein contents and better ultraviolet absorption spectra than the other methods tested. Nucleic acids were extracted from leaves of 14 other species of plants, in addition to cotton, by this modified NaCl procedure.

Journal Article↗

PubMed1996

Analytic performance and contamination control methods of a ligase chain reaction DNA amplification assay for detection of Chlamydia trachomatis in urogenital specimens.

A ligase chain reaction (LCR) DNA amplification assay that targeted the cryptic plasmid of Chlamydia trachomatis was developed to detect C. trachomatis urogenital tract infection. The objectives of this study were to determine the cutoff and analytic performance of the LCR assay and to characterize the effectiveness of its postdetection contamination control method. The assay's cutoff was determined after receiver-operator characteristic (ROC) analysis of 4660 clinical data points. The assay detected one infectious unit per reaction of each of the 15 C. trachomatis serovars and did not cross-react with 13 Chlamydia pneumoniae strains, 13 Chlamydia psittaci strains, and 87 other bacteria, fungi, parasites, or viruses. In addition, the assay did not detect 77 processed urine specimens collected from patients with urinary tract infections caused by yeast or bacteria other than C. trachomatis. The assay was sufficiently precise to detect consistently two infectious units of C. trachomatis per reaction. False-positive assay results attributable to contamination with amplified product were minimized by the use of standard procedures as well as by a postdetection chemical inactivation method that could reduce the amount of amplified LCR product by a factor of > or = 10(7).

Chlamydia trachomatis↗

PubMed1999

Analysis of ovarian borderline tumors using comparative genomic hybridization and fluorescence in situ hybridization.

It is unclear whether ovarian borderline tumors (tumors of low malignant potential) are independent entities or whether they are part of a continuum of tumor progression that culminates in ovarian carcinoma. Little is known about genetic abnormalities in borderline tumors because of the difficulty of growing them in culture for chromosome studies, and because the low ratio of tumor to nontumor cells can interfere with molecular genetic examination. To circumvent these problems, we performed comparative genomic hybridization (CGH) on 10 serous borderline tumors from nine patients, using microdissection to enrich the samples for tumor DNA and reduce contamination from stromal and inflammatory cells. CGH analysis revealed that three of the tumors had detectable chromosomal imbalances, whereas seven were in a balanced state. In those tumors with imbalances, the number of abnormalities ranged from 3-6 per tumor. Additional studies by fluorescence in situ hybridization (FISH) on disaggregated nuclei confirmed the imbalances detected by CGH, revealed one tumor to be hypertriploid, and indicated that the remaining tumors were diploid and in a balanced state. All abnormalities observed in the aneuploid cases are consistent with chromosomal aberrations previously reported for ovarian carinomas, providing further evidence that some borderline tumors are part of a continuum of tumor progression. These results also suggest that there may be different mechanisms leading to borderline tumor formation, including one associated with multiple chromosomal imbalances, and others that do not involve imbalances detectable by CGH. Genes Chromosomes Cancer 25:307-315, 1999.

Adult↗