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At least 955 records · Page 53Linked to original sources
PubMed1988

Diagnostic significance of flow cytometric DNA analysis applied for the detection of cancer cells in bronchial washing fluid.

Since both DNA aneuploidy and increased proliferative activity are important characteristics of malignant neoplasms, flow cytometric (FCM) analysis was used to examine the cell content in bronchial washing samples obtained via fiberoptic bronchoscopy from 73 patients. The results were compared with the results of histology and conventional cytology. The patients included 30 with bronchial carcinomas, 12 with bronchopneumonia and 31 with no evidence of lung disease. Of the 30 patients with histologically confirmed lung cancers, 25 showed either aneuploid stem lines (19 cases) or high levels of proliferation (6 cases) as determined by analysis of cell-cycle stages. The same rate of cancer cell detection was obtained by cytology. In the 43 cases with neither histologic nor clinical evidence of malignancy, FCM data yielded 5 false-positive results, as compared to 4 erroneous suspicions of cancer by cytology. From these data, it is concluded that FCM measurements of both DNA ploidy and proliferative activity may complement conventional cytology in the recognition of bronchial carcinomas.

Bronchitis↗
PubMed2006

Colorectal cancer screening using stool DNA analysis in clinical practice: early clinical experience with respect to patient acceptance and colonoscopic follow-up of abnormal tests.

BACKGROUND: Stool-based DNA screening for colorectal cancer (CRC) was recently made available for use in daily clinical practice (PreGen-Plus). The main objectives of this study were to examine patients' screening experiences with stool DNA testing in routine clinical practice and the results of diagnostic colonoscopy in patients with an antecedent abnormal stool DNA test. PATIENTS AND METHODS: Patients undergoing stool-based DNA testing were asked to complete and return via mail an anonymous 10-item questionnaire inquiring about their test-related experiences. Colonoscopy findings for all abnormal stool-based DNA tests were ascertained via a telephone survey of the ordering primary care clinicians' offices. RESULTS: Patient survey responses were collected between August 2003 and July 2005 and reflect an 18% (1211 of 6730) response rate. The majority reported that the specimen collection process was very easy/easy to perform (87%), that they were very likely/likely to use the test again (91%), and that they had never been screened for CRC previously by any method (52%). Tests were ordered predominantly by the patient's primary care clinician (90%), including obstetrician/gynecologist providers. Colonoscopy findings from 69 of 159 patients with an antecedent abnormal stool DNA test screened with PreGen-Plus between August 2003 and July 2004 were available for review. An abnormal stool DNA test correlated with a colonoscopically demonstrable abnormality in 49% of cases (34 of 69). Abnormal findings, including CRC in 3 patients (4%; 1 with Dukes A and 2 with Dukes B disease), single or multiple adenomatous polyps in 23 patients (33%), hyperplastic polyps in 3 patients (4%), and colitis in 5 patients (7%). Colonoscopy was reported as negative in 51% of patients (35 of 69), including 2 cases (3%) with an altered BAT-26 microsatellite caused by a normal polymorphism. CONCLUSION: Stool DNA testing provides an acceptable noninvasive alternative for CRC screening that can identify early-stage CRCs and adenomatous polyps in routine clinical practice. Ongoing and broader surveys are indicated to support these early findings.

Aged↗
PubMed1996

Effect of environmental factors on PCR-DNA analysis from dental pulp.

This study was designed to observe the results of DNA typing on teeth subjected to aging, different temperatures and various environmental factors. A total of 570 teeth were studied. The study included the analysis of the PCR-based polymorphisms HLA DQA1, D1S80, HUMTH01, HUMFES/FPS and the XY homologous gene amelogenin. In general the best results were obtained with the XY homologous gene amelogenin, followed by the two STRs studied (HUMTH01 and HUMFES/FPS). The small fragment sizes and the method of detection used after PCR amplification are the main factors explaining this fact. In general, teeth submerged in water gave the poorest results. Teeth exposed to outdoor conditions provided better results than teeth buried in sand or soil, but even in these cases good results were obtained. Up to 4 degree C, temperature had only a slight influence on the results. Positive results were obtained in most cases at high temperatures (400 degrees C for 2 min) which are rarely reached in practical casework. Positive typing results for the XY homologous gene amelogenin and the STRs were obtained from teeth 10-30 years old. The usefulness of dental pulp for identification purposes is exemplified in some actual cases.

DNA Fingerprinting↗
PubMed1994

Flow cytometric DNA analysis of breast cancer by two colour method using cytokeratin labeling for identification of tumour cells.

Flow cytometric assessment of DNA-ploidy and S-phase fraction in breast cancer is compromised by the heterogeneity of cell subpopulations derived from the malignant and surrounding connective tissue, e.g. tumour, stromal and inflammatory cells. To identify tumour cell subpopulations, epithelial cells were labeled by a FITC-conjugated cytokeratin antibody (CK6, CK18) prior to flow cytometric cell cycle analysis in 205 fresh specimens of primary breast cancer. We found 158/205 (77%) DNA-aneuploid tumours compared to 127/205 (62%) without identification of cytokeratin positive cells (P < 0.001). In addition, the number of detected DNA-multiploid tumours rose from 31 (15%) to 51 (25%) after gating for cytokeratin positive cells. In DNA-diploid tumours, S-phase and G2M-phase fractions were significantly higher in cytokeratin positive (tumour) cells compared to total cell populations (4.4% and 5.8% vs. 3.2% and 4.4%; P < 0.001). Cytokeratin negative cells were found in all tumours and can be used as internal standard for calculation of ploidy and for quality control (CV, linearity) of each individual sample. We conclude that at least 20% of DNA-aneuploid tumours would not have been diagnosed without cytokeratin labeling. In addition, influence of non-tumourous cell elements on cell cycle analysis can be markedly reduced. Therefore, both determination of DNA-ploidy and cell cycle analysis can be optimized by cytokeratin labeling.

Breast Neoplasms↗
PubMed1992

DNA analysis of Borrelia burgdorferi NCH-1, the first northcentral U.S. human Lyme disease isolate.

The DNA of the first northcentral United States human Lyme disease isolate, Borrellia burgdorferi NCH-1, was characterized and compared with the DNAs of nine other B. burgdorferi isolates. Strain NCH-1 was isolated in August 1989 from a human skin biopsy specimen. DNA was analyzed by pulsed-field gel electrophoresis and restriction endonuclease analysis. Contour-clamped homogeneous electric field pulsed-field gel electrophoresis of in situ-lysed cells was performed to compare the plasmid profiles of the various isolates. The plasmid profile of isolate NCH-1, which included five plasmids of approximately 69, 42, 38, 32, and 23 kb, could be distinguished from those of the other isolates examined. The DNA profile of NCH-1 was most similar to those of strain 297 (human cerebrospinal fluid isolate, Connecticut) and strain PAL (human erythema migrans isolate, New York) and most dissimilar from those of strain P/Gau (human erythema migrans isolate, Germany) and strain IPF (Ixodes persulcatus tick isolate, Japan). These results indicate that genetic diversity exists among B. burgdorferi strains isolated from different geographical areas.

Base Composition↗
PubMed1993

DNA analysis (ploidy) of molar pregnancies with image analysis on paraffin tissue sections.

Hydatidiform moles can be subclassified based on their ploidy. In general, complete moles are diploid, and partial moles are triploid. The standard method for the determination of DNA content is flow cytometric analysis. In this study, the authors investigated whether static cytometric analysis with the CAS 200 Image Analyzer (Cell Analysis Systems, Inc., Elmhurst, IL) with a software program designed for quantitation of nuclear DNA content in tissue sections can be used to classify moles. Tissue sections from 17 moles were analyzed with this system, and the results were compared with those obtained with flow cytometric analysis. It was found that cell selection was an important factor. A high proportion of the hyperplastic trophoblast was in G2M. Exclusion of these areas and measurement of the trophoblast lining the villi only led to reliable results, and complete agreement between the results of the two methods was obtained. The findings indicate that cytometric analysis on tissue sections is a reliable alternative to flow cytometric analysis for the designation of moles as diploid or triploid.

DNA↗
PubMedDate not supplied

Flow cytometric DNA analysis of normal and cancerous human endometrium and cytological-histopathological correlations.

The DNA content in individual cells from 112 histopathologically normal endometria and from 222 malignant endometrial tumors was measured using flow cytometry. In the normal endometrial cases only single DNA peaks were found, all in the diploid region, and the range of DNA index values was used for defining the limits for diploid tumor cases. In most cases with aneuploid cell populations, an additional peak was found in the normal diploid region. However, combined cytological and histopathological analysis showed that a majority of these diploid cells were to be considered as tumor cells. Aneuploid cell populations were found in 43% of malignant endometria; in the remaining endometrial carcinomas, the flow cytometrical findings showed no differences compared to those of benign tissue. Flow cytometry in this respect did not prove useful as a diagnostic screening method. Ploidy aberrations were correlated to histopathology. Aneuploidy was more common (62%) in poorly differentiated tumors than in highly/moderately differentiated tumors (29%). Two or more aneuploid cell populations were found in 6% of the cases. No difference in aneuploidy was found between FIGO stage I and II (36% and 34%), but aneuploidy was more frequent in stage IV (86%). In normal endometria the fraction of cells with DNA content corresponding to S-phase (S-fraction) was 9.7% on average in the proliferative phase and 6.2% in the secretory phase. In well and moderately differentiated diploid tumors the S-fraction was about the same (8.8% and 9.2%), but in poorly differentiated tumors it was significantly higher (12-16.5%).

Adenocarcinoma↗
PubMed2001

Use of DNase to eliminate contamination in ancient DNA analysis.

Using polymerase chain reaction (PCR) amplification, it is possible to analyze DNA from limited source template. This method has proved especially valuable in studies of ancient DNA and in forensic investigations. However, PCR reactions containing minimal or damaged source template are prone to contamination by DNA from a number of other sources. While standard protocols to prevent and/or detect contamination do exist, methods of eliminating contamination are needed to ensure the validity of results obtained. We present a method to eliminate sources of contamination in reagents and labware through the use of a DNase prior to PCR amplification without damaging even the minimal amounts of template present in ancient DNA samples. This method, suggested previously for forensics applications, appears to be effective in eliminating contamination without interfering with the amplification of ancient template.

Deoxyribonucleases↗
PubMed1995

Applications of flow cytometric DNA analysis to diagnostic cytology.

Flow cytometry is a rapid method for measuring DNA content. Its high sensitivity and specificity in detecting transitional cell carcinomas in bladder washings should make it a routinely applied adjunct to cytology once universal laboratory standards are firmly established. Diagnostic and prognostic information on solid tumors can be obtained at least as reliably on fine-needle aspirations as on surgically resected specimens. At the present time, the sensitivity of FCM in the evaluation of effusions, peritoneal washings, and CSF is relatively low, and although in some cases malignant cells in these specimens that are missed by conventional cytology are detected by FCM, the number of such cases is small. Investigation continues into the application of FCM to the screening of cervical specimens.

Ascitic Fluid↗
PubMed1988

Flow cytometric DNA analysis of neuroblastoma: correlation with prognostic variables and survival of patients.

The DNA ploidy of tumor tissues obtained from 41 patients with neuroblastoma, or ganglioneuroblastoma, which is the histologic variant of neuroblastoma, was determined by flow cytometry. The DNA ploidy was diploid in 7 tumors (5 neuroblastomas and 2 ganglioneuroblastomas) and aneuploid in 34 tumors (20 neuroblastomas and 14 ganglioneuroblastomas). The DNA ploidy of tumor cells did not correlate with the survival of patients and there was no correlation between the DNA ploidy of tumor cells and such prognostic variables, histology, primary site, staging of tumors and operative curability.

Cell Separation↗
PubMed1998

DNA analysis of temperate bacteriophage Aa(phi)23 isolated from actinobacillus actinomycetemcomitans.

The DNA of the temperate bacteriophage Aaphi23 isolated from the oral bacterium Actinobacillus actinomycetemcomitans was examined structurally both in the phage head and in the prophage. The DNA in phage particles comprises 44 kb linear molecules with a terminal redundancy of 1.6 kb, which represent circular permutations. Thus, DNA is packaged into phage heads by the headful mechanism. The Aaphi23 prophage is integrated into the host chromosome.

Aggregatibacter actinomycetemcomitans↗
PubMed2005

Prenatal and newborn paternity testing with DNA analysis.

In rape against youthful girls which yields pregnancy after the abortion DNA examinations can be performed from the aborted foetal material to provide evidence of paternity of the suspect. In our present work we demonstrate six cases: four of them are rape cases and two where the mother abandoned her newborn baby. These cases proved that DNA-STR profiles can be determined from foetus after the abortion and perpetrator of a rape can be found. Due to our result we suggest that not only placenta but also bloody vernix caseosa is useful tissue for identifying the putative mother because vernix caseosa can be the carrier of the mother's blood.

Aborted Fetus↗