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At least 469 records · Page 26Linked to original sources
PubMed1978

Cystic kidneys, renal dysplasia and microdissection data in 5 children with congenital valvular urethral obstruction.

A survey of the findings in 5 children with urethral obstruction due to valves is presented. The microdissection data found in the 7 kidneys of this series were compared. The microdissection findings in all 7 kidneys are mostly the same with a continuum of processes ranging from relatively mild to severe derangements. We could not find two varieties of renal change designated type II or IV by potter. The characterization of the lesions by nephron dissection always approached those of the type II (multicystic, dysplastic kidney). Renal dysplasia was associated with extrarenal malformations in 2 of our cases and we therefore believe that the significance of the dysplasia lies rather in the period of the insult during organogenesis than in the obstruction.

Autopsy↗
PubMed1978

Structural changes of experimental glomerulonephritis in rats as revealed by microdissection.

Microdissection revealed striking alterations in the nephrons of animal models AICN and anti-GBMN. The most severely damaged AICN kidney in the series presented marked heterogeneity in the size and deformity of the proximal tubules, corresponding to the diverse and variegated nephrons described by Oliver in chronic Bright's disease. The severely damaged anti-GBMN kidneys revealed widespread alterations in the proximal tubules, which, however, tended to be fairly uniform among the affected nephrons. This uniformity, perhaps, reflected the shorter duration of disease in the anti-GBMN animals. The most characteristic proximal tubular alteration in either the AICN or anti-GBMN animals was that combining atrophy of the pars convoluta and hypertrophy of the pars recta in same tubule. The largest and smallest nephrons encountered in the entire study were found in the most severly damaged kidney in the AICN. This finding reflected the simultaneous existence of regressive and progressive changes in this kidney, as certain nephrons underwent hypertrophy to compensate for the atrophy and disappearance of others. The remarkable functional glomerulotubular balance of single nephrons known to exist in both AICN and anti-GBMN was matched by the evidence presented here of structural glomerulotubular balance among the severely altered nephrons of a representative kidney from each group. Microdissection studies directed toward the characterization of the nephronic alterations in both membranous glomerulonephritis and proliferative glomerulonephritis of man should be of interest in relation to the findings in these experimental rat models of human disease.

Animals↗
PubMed1995

Allelic loss on chromosome 8p12-21 in microdissected prostatic intraepithelial neoplasia.

The development and progression of human prostate cancer is associated with genetic abnormalities in tumor cells. Inactivation of tumor suppressor genes due to allelic loss is thought to be an important mechanism of gene alteration in prostatic neoplasms. In this study we examined allelic loss on chromosome 8p12-21 in microdissected samples of normal prostatic epithelium, high grade prostatic intraepithelial neoplasia (PIN), and invasive prostate carcinoma from the same patients. Tissue microdissection under direct microscopic visualization procures pure populations of cells of interest, including small lesions such as PIN. Among 30 patients with concomitant cancer and PIN, we found loss of heterozygosity on chromosome 8p12-21 in 63% (34 of 54) of foci of PIN examined and 90.6% (29 of 32) of tumors, suggesting that abnormalities on chromosome 8p12-21 may be important in the early stages of prostatic carcinoma development. Several cases in which multiple foci of PIN from the same patient were sampled showed different patterns of allelic loss. Fifty-five % (16 of 29) of the prostate carcinomas contained a potential precursor PIN focus based on allelic loss pattern. Our results are consistent with the hypothesis that PIN arises multifocally within the prostate gland, and that a subset of these lesions progress to become carcinoma.

Alleles↗
PubMed1994

[Microdissection of human chromosome 1].

This work began with chromosome preparation and microdissection. Booster IRS-PCR was developed to amplify DNA dissected form human chromosome 1. The accuracy of microdissection was demonstrated by chromosomal in situ suppression (CISS)-hybridization. The amplified DNA fragments were ligated to pUC 18 vector at SmaI site and the average size of the inserts was about 450bp.

Chromosomes, Human, Pair 1↗
PubMed1995

A microdissection technique for archival DNA analysis of specific cell populations in lesions < 1 mm in size.

We have developed a microdissection technique that allows for procurement and analysis of specific, minute cell populations from routine, 5-mu, formalin-fixed, paraffin-embedded histological tissue sections. Lesions < 1 mm in size can be specifically examined. Cells of interest are procured under direct microscopic visualization followed by a single-step DNA extraction and subsequent polymerase chain reaction. Amplification of DNA from selected cell populations was demonstrated by detecting a loss of heterozygosity (LOH) at the von Hippel-Lindau disease (VHL) gene in an atypical renal lesion and a renal cell carcinoma in a kidney of a VHL patient. Moreover, previously unrecognized LOH on the short arm of chromosome 3 (3p25-26) was detected in microdissected colorectal carcinoma cells in a non-VHL patient with sporadic colon carcinoma. This technique should prove useful in DNA studies of small lesions and cell populations. Furthermore, microscopic premalignant, in situ, and invasive lesions can be selectively examined.

Base Sequence↗
PubMed1993

[Laser chromosome microdissection and cloning of the genetic disease loci].

We have developed an argon ion laser chromosome microdissection technique in conjunction with a single unique primer polymerase chain reaction (SUP-PCR) to directly amplify microdissected chromosomes. The 22-mer primer used in PCR, although unique in sequence, randomly primed and amplified any target DNA. These methods were applied to both the terminal region of the human chromosome 4p (4p 16) and Xq (Xq26-q28), and two chromosome region-specific DNA libraries were constructed. The resulting libraries contained approximately 1000 nonoverlapping DNA sequences with an average size of 230-350 bp, at an average spacing of 10-65 Kbp along the chromosomes of origin. Our new method is a simple and general approach for constructing a chromosome region-specific DNA library from a single metaphase spread.

Base Sequence↗
PubMedDate not supplied

Microdissection as a means to verify allelic imbalance in tumour biology samples.

Allelotypes (TP53, AFM051xd10 and alu-i1) in normal DNA and in DNA from paraffin-embedded tumours of a patient with a p53 germ-line mutation were compared in order to demonstrate LOH. Microdissection was applied in order to overcome difficulties with the interpretation of LOH data from a pelvic recurrence of a primary malignant histiocytoma. Furthermore, a rapid and simple boiling method was developed in order to reduce the loss of DNA usually occurring during traditional methods for DNA extraction. The conclusion drawn is that it is of utmost importance to use highly enriched fractions of tumour cells when performing LOH-studies. It is also shown that a rapid and simple boiling procedure is sufficient to release enough DNA of microdissection-enriched tumour cells for microsatellite analysis by PCR to detect allelic imbalance.

Alleles↗
PubMed1996

Allelic imbalance at NME1 in microdissected primary and metastatic human colorectal carcinomas is frequent but not associated with metastasis to lymph nodes or liver.

Allelic imbalance at the NME locus on chromosome 17q21 was analyzed in colorectal cancer patients using a highly polymorphic microsatellite repeat sequence within NME1 itself. Duplicate samples of carcinoma and adjacent normal tissue was obtained by microdissection from 6 to 7-microns paraffin sections of 94 primary carcinomas (treatment years 1979-1993) and available lymph node and liver secondaries. In 55 patients informative (heterozygous) at this locus, allelic imbalance was examined in primary and secondary carcinomas. Microsatellite instability prevented assessment of allelic balance in two cases, and there was no evidence of homozygous loss at NME1 in any case analyzed. Allelic imbalance at the NME locus in carcinomas was frequent (27/53; 51%), and concordant results were obtained between primary carcinoma and secondary deposits in 30 of 33 (91%) cases. Three discordant cases showed allelic imbalance in secondary deposits but not the primary lesion. Although frequent, allelic imbalance at NME1 had no relationship to Dukes' stage at presentation or with subsequent hepatic metastasis, nor with the primary carcinoma site (proximal versus distal), tumor size, or mitotic or apoptotic index. Moreover, neither disease-free nor overall survival differed between patients with carcinomas showing NME1 allelic imbalance and patients with carcinomas that did not. Our results show that although allelic imbalance is frequent at the NME locus in primary and secondary colorectal carcinomas, there is no evidence to link this with clinical or pathological features or with metastatic potential. Microsatellite PCR and microdissection of enriched populations of carcinoma cells allowed uniformly successful analysis of samples from archival formalin-fixed paraffin-embedded tissue up to 15 years old and clear assessment of allelic imbalance in tumor specimens. Target sequences (e.g., microsatellites and minisatellites) up to approximately 200-250 bp may be reliably analyzed for allelic balance, suggesting that this method is of general utility in the genetic analysis of primary and metastatic neoplasia.

Adenocarcinoma↗
PubMed1997

Microdissection and polymerase chain reaction amplification of genomic DNA from histological tissue sections.

Polymerase chain reaction (PCR)-based assays are being used increasingly to study the molecular genetic changes that occur in minute cellular lesions that are identified in histological sections. It is often desirable to microdissect the cells of interest in a lesion, isolating them from surrounding normal tissue to obtain the purest representation of genomic DNA possible. We present here an optimized microdissection and DNA extraction protocol that reliably produces PCR-amplifiable DNA from lesional tissue less than 0.1 mm in diameter. The utility of this technique is demonstrated by PCR amplification and sequencing of the K-ras gene and microsatellite PCR analysis of proliferative epithelial lesions in the small ducts of a human pancreas involved by cancer.

DNA↗
PubMed1997

[Clonal analysis in cells using PCR and laser microdissection].

Clonality represents one of the hallmarks of neoplastic cell growth. X-chromosomal inactivation patterns have been used to determine clonality in various tumors. This approach is limited by admixture of polyclonal non-tumor stroma cells among which the monoclonal proliferation may be missed. In order to overcome this limitation, we combined a sensitive PCR based DNA analysis with a highly selective microdissection technique using a laser beam. In sections of intraductal mammary carcinomas tumor cell complexes of at least 100 cells were isolated by removing the surrounding stroma by laser irradiation. Thereby, tumor cells could be isolated without contaminating non-neoplastic elements. Clonality in these cells was determined using two X-chromosomal polymorphic sites-phosphoglycerate kinase 1 (PGK1) and human androgen receptor (HUMARA). Control experiments could show the polyclonal nature of the surrounding tissue. Moreover, complete destruction of DNA by laser irradiation was assured. The technique requires a certain amount of cells and DNA in order to avoid artefacts that result from preferential amplification of exclusively one X-chromosomal allele in small samples. We conclude that combination of laser-microdissection with PCR analysis of X-chromosomal inactivation patterns enables the detection of clonal cell populations in heterogeneous tissues. Studies of clonality in borderline cases between reactive and neoplastic proliferations or premalignant lesions are made possible by this technique.

Breast Neoplasms↗
PubMed1998

Characterization of a de novo unbalanced translocation t(14q18q) using microdissection and fluorescence in situ hybridization.

We report on a patient with a de novo translocation between the long arms of chromosomes 14 and 18. The translocation was studied using microdissection in combination with fluorescence in situ hybridization (micro-FISH). Five copies of the chromosomes involved in the translocation were isolated by microdissection and amplified by means of degenerate oligonucleotide primed-polymerase chain reaction (DOP-PCR). Reverse chromosome painting with the biotin-labeled PCR product showed that part of the q-arm of chromosome 18 had no signal. The deletion was characterized further by FISH with band-specific probes and it was concluded that the rearrangement was unbalanced: 46,XY,t(14;18)(14pter-->14q22::18q21.1-->18qter) (18pter-->18q12.2::14q22-->14qter). The patient, who presented with psychomotor retardation, mild obesity, pes equinovarus, strabismus, and facial anomalies, is compared with previously reported patients with an interstitial deletion of band 18q12.

Child, Preschool↗
PubMedDate not supplied

Applications of tissue microdissection in cancer genetics.

A major obstacle to apply molecular biologic techniques effectively to the somatic genetic analysis of neoplastic tissue is the presence of abundant nonneoplastic elements in the analyzed specimen. These nonneoplastic elements, including reactive fibrous cells, vascular cells, and a variety of infiltrating white blood cells, may mask genetic alterations that otherwise would be easily detectable if the neoplastic cells were procured selectively. We have developed a microdissection technique which allows to selectively procure and genetically analyze small populations of neoplastic cells from the glass slide. In this report, we describe the microdissection technique and genetic analysis of archival frozen and paraffin-embedded tissue in general. Then, we review some implications of this approach of genetic analysis for mapping and cloning of new genes, identification of premalignant lesions, and differential analysis of different histologic components within the same tumor.

Barrett Esophagus↗
PubMed1998

Different patterns of p53 mutations in prostatic intraepithelial neoplasia and concurrent carcinoma: analysis of microdissected specimens.

Prostatic intraepithelial neoplasia (PIN) is characterized by intraluminal proliferation of epithelial cells and can be divided into high-grade (HGPIN) and low-grade (LGPIN) lesions. HGPIN is regarded as the most likely precursor of prostatic carcinoma (PCA). Microdissected DNA selectively extracted from paraffin-embedded sections of 29 cases of PCA and 1 benign prostatic hypertrophy were analyzed for p53 mutation by single-strand conformation polymorphism (SSCP) of polymerase chain reaction (PCR)-amplified DNA fragments followed by direct sequencing. These patients had received total prostatectomy (27 cases) or transurethral resection (3 cases). Under direct microscopic observation, DNA was microdissected from 108 lesions: 67 lesions from 22 cases of PIN (55 HGPIN and 12 LGPIN), 29 from 22 cases of PCA, and 12 from 11 cases of adjoining benign glands. Analysis revealed 13 mutations in 10 lesions from six cases. All 13 were point mutations: 7 missense, 5 silent, and 1 nonsense. Mutations were detected in 3 cases (14%) of PIN and 5 cases (25%) of PCA. PIN lesions with p53 mutations were all categorized as HGPIN. Neither LGPIN nor benign glands adjoining PIN and/or PCA had mutations. Two PIN and one PCA lesion in each of two cases had mutations that were different from each other. G-to-A transition was the commonest mutation pattern. The current findings showed that HGPIN, but not LGPIN, and PCA are similar with regard to p53 mutation. The diverse patterns of p53 mutation among HGPIN and PCA lesions suggested multiclonal development of prostatic precancerous lesions.

Amino Acid Substitution↗
PubMed1998

An improved method for construction of directionally cloned cDNA libraries from microdissected cells.

Here, we developed an improved method for constructing microdissected cDNA libraries, based on strand-switching properties of reverse transcriptase, followed by PCR amplification with primers to mediate unidirectional insert cloning. Using RNA from microdissected ovarian carcinoma cells, we constructed a cDNA library consisting of 1.3 x 10(6) unidirectional recombinants with an average insert size of 500 bp. Single-pass sequencing of 100 clones with the T7 primer revealed 89 inserts derived from known genes, anonymous expressed sequence tags (ESTs), or novel sequences. Among these clones were known genes and ESTs previously found in cDNA libraries from bulk ovarian tissue RNA, sequences seen for the first time in an ovarian-derived library, and novel sequences not previously seen in any cDNA library. These results demonstrate a methodology for constructing quality cDNA libraries that are cloned in a unidirectional fashion, are complex and diverse, and reflect the tissue of origin.

Actins↗
PubMed1997

A simple approach to single-cell microdissection and molecular analysis.

OBJECTIVE: To develop a simple approach to single-cell microdissection from Papanicolaou-stained smears and to determine its usefulness in molecular diagnosis using archival cytologic material. STUDY DESIGN: Culture cells from three cell lines (TT, A549 and Lu65) were used to prepare Papanicolaou-stained smears. Mount-Quick, a mounting medium, was used to establish the method of sorting target single cells from smear slides under direct microscopic observation. Calcitonin receptor gene and codon 12 of the K-ras oncogene were amplified to check the application of single-cell genetic analysis in cytology. RESULTS: The target single cell could be simply sorted from Papanicolaou-stained smears using the Mount-Quick microdissection technique. Boiling in water was more suitable for preparing DNA from a single cell or from fewer than five cells versus other methods. Analysis of calcitonin receptor gene and K-ras codon 12 demonstrated that molecular analysis was applicable to a single cell or a few cells from archival Papanicolaou-stained smears. CONCLUSION: This approach has significant implications for cytology: (1) it circumvents the limitations of molecular analysis in cytology and makes the combination of molecular analysis and morphologic diagnosis possible in cases with limited materials; (2) the remaining part of the smear is still preserved well for additional analysis; and (3) the approach is simple, economical and practical for cytology as well as histology.

DNA, Neoplasm↗
PubMed2005

A search for CDKN2A/p16INK4a mutations in melanocytic nevi from patients with melanoma and spouse controls by use of laser-captured microdissection.

OBJECTIVE: To determine the frequency at which the CDKN2A coding region is mutated in the atypical nevi of persons with sporadic melanoma. DESIGN: DNA samples, isolated by laser-captured microdissection of atypical nevi from 10 patients with newly incident cases of sporadic melanoma and their spouses as matched controls, were used as templates for nested polymerase chain reaction amplification of CDKN2A exons 1 and 2. RESULTS: No point mutations in the coding region of CDKN2A were observed in any of the melanocytic nevi. CONCLUSIONS: Point mutations in CDKN2A are an uncommon event in the atypical nevi of persons with melanoma. As such, the data may support a hypothesis of melanocytic nevus histogenesis, in which the melanocytic nevus and malignant melanoma represent separate, pleiotropic pathways resulting from common stimuli, such as genomic damage from UV radiation.

Alleles↗
PubMed2004

Laser capture microdissection (LCM) for analysis of gene expression in specific tissues during embryonic epithelial-mesenchymal transformation.

The analysis of gene expression in developing organs is a valuable tool for the assessment of genetic fingerprints during the various stages of tissue differentiation and epithelial-mesenchymal transformation (EMT). However, the variety of differentiating cells and the close association of epithelial and mesenchymal cells makes it difficult to extract protein and mRNA from specific cells and tissue and, thus, to assign expressed genes to specific cell populations. We report here the analysis of LEF1 mRNA in epithelial and mesenchymal cells isolated by LCM from different stages of EMT during development of the mouse palate and describe our techniques in detail. By applying a laser capture microdissection (LCM) technique and real-time polymerase chain reaction, we were able to determine mRNA levels that accurately reflect changes in gene expression in specific cells. The sensitivity of the technique is remarkable. Indeed, the mRNAs can be detected for many proteins too low in abundance to stain with antibodies. These techniques will enable embryologists to collect homogeneous groups of cells from heterogeneous populations in developing organs, which otherwise would not be available for gene analysis.

Animals↗