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PubMed1989

Isolation of Fixed and Viable Eggs, Central Cells, and Embryo Sacs from Ovules of Plumbago zeylanica.

Three alternative protocols for light microscopy, electron microscopy, and biochemical characterization of isolated megagametophytic tissues are described employing enzymic maceration and microdissection of living and fixed ovular tissue of Plumbago zeylanica. Morphologically well preserved megagametophytes are obtained using fixed ovules in two different regimes (nearly 40 and 60% yield, respectively). Fluorescein diacetate-positive megagametophytic cells are recovered in nearly 20% of unfixed ovules using the third regime.

Journal Article↗
PubMed1994

Ultrathin-layer microelectrophoretic determination of lactate dehydrogenase isoenzymes in corneal and conjunctival epithelium of the cow.

In order to evaluate the impact of tissue oxygenation on the distribution pattern of lactate dehydrogenase isoenzymes, activities of the isoenzymes were measured in microdissected samples of bovine tissue. A highly sensitive ultrathin-layer electrophoretic technique was used to determine the distribution pattern of lactate dehydrogenase isoenzymes in basal, intermediate and superficial layers of the epithelium of central and peripheral cornea and in the epithelium of the bulbar conjunctiva. Measurements revealed almost homogeneous intraepithelial distribution patterns of lactate dehydrogenase isoenzymes in both tissues. In the cornea the lactate dehydrogenase isoenzymes 4 and 5, which are regarded to be specialized for anaerobic glucose metabolism, were found to predominate. In the well-oxygenated conjunctival epithelium most of the activity could be ascribed to the lactate dehydrogenase isoenzyme 3. In contrast to the isoenzymatic activities, total activity of lactate dehydrogenase was inhomogeneously distributed; maximum activities were found in the basal layer of corneal epithelium and in the intermediate layer of conjunctival epithelium. The results indicate that oxygen supply is relevant rather for the intraepithelial distribution of total enzyme activity than for the expression of lactate dehydrogenase isoenzymes.

Animals↗
PubMed2005

Combined laser capture microdissection and serial analysis of gene expression from human tissue samples.

Cell-specific gene expression profiling from heterogeneous human tissues is confounded by cell purification limitations. Here, we describe a technique to generate gene expression profiles of pure populations of prostate cancer cells obtained from fresh-frozen prostatectomy specimens and small initial quantities of RNA by combining laser capture microdissection and microserial analysis of gene expression (LCM-microSAGE). Two microSAGE libraries were obtained from approximately 100,000 laser pulses, estimated to contain fewer than 3 x 10(5) cells and 20-30 ng mRNA. Two libraries were sequenced to a depth of 10,111 and 10,463 unique tags from normal and cancer cells, representing 6453 and 6923 genes, respectively. Most transcripts were expressed at similar levels, but cancer cells compared with normal cells had increased expression of 385 tags and decreased expression of 389 tags. A total of 20 genes were differentially expressed (P<0.05); five of these genes were upregulated and 15 were downregulated in cancer cells. Quantitative reverse transcriptase-polymerase chain reaction results from three selected genes corroborated the existence of cell-specific gene expression in LCM-microSAGE-derived libraries. In conclusion, the LCM-microSAGE approach demonstrates that large-scale expression profiles of known and unknown transcripts can be generated from pure populations of target cells obtained from human tissue samples comprised of heterogeneous mixtures of cell types.

Gene Expression Profiling↗
PubMed2002

Quantifying porphobilinogen deaminase mRNA in microdissected nephron segments by a modified RT-PCR.

BACKGROUND: Quantifying mRNA levels by reverse transcription-polymerase chain reaction (RT-PCR), although widely exercised, is still difficult. METHODS: A modified quantitative RT-PCR in which genomic DNA was used as standard was developed. The quantity of mRNA was expressed as the ratio of the PCR product from cDNA and that from genomic DNA (CG ratio). Nephron distribution of porphobilinogen deaminase (PBGD) mRNA was examined in microdissected nephron segments using the method. The enzyme activity and mRNA quantity of PBGD also were measured in tissue homogenates. RESULTS: Tubular segments expressed substantially more PBGD mRNA than glomeruli (expressed as CG ratios, 1.04 +/- 0.10 in glomeruli, 4.53 +/- 0.32 in PCT, 5.71 +/- 0.25 in PST, 5.13 +/- 0.52 in mTAL, 5.29 +/- 0.20 in cTAL, 4.05 +/- 0.35 in DCT, 2.88 +/- 0.25 in CCD, and 4.90 +/- 0.24 in OMCD). PBGD mRNA level in liver homogenate (3.17 +/- 0.36) was much higher than glomeruli but lower than most of the tubular segments. The enzyme activity in tissue homogenates correlated well with mRNA levels. CONCLUSION: The method reported here is simple and reliable, and especially suitable for quantitating specific mRNA amounts in minute tissue samples such as microdissected nephron segments.

Actins↗
PubMed2003

Prospects for tissue-specific analysis of gene expression in Xenopus embryos through laser-mediated microdissection of histological sections.

Analysis of spatiotemporal patterns of gene expression is an important prerequisite for understanding the molecular basis of embryogenesis. Tissue-specific resolution is desirable, but often not achieved owing to methodical limitations. We used a common model system for embryonic development--the South African clawed frog Xenopus laevis--to demonstrate that laser microdissection and laser-mediated catapulting of tissue samples from histologic sections are feasible even for yolk-rich, fragile embryonic tissue. A combination with RT-PCR provides the possibility of detecting tissue-specific gene expression with high resolution and fidelity. We show that specimens of various sizes and shapes can easily be procured by laser microdissection and pressure catapulting (LMPC). Subsequent RNA-isolation and nested RT-PCR for marker genes revealed that the combination of these methods allows for analysis of specific gene expression in micro-areas. We report on the efficiency and reliability of detection of marker genes in dissected tissue. We further discuss the question of whether such a combination can be applied to certain issues raised in developmental biology with regard to other techniques.

Animals↗
PubMed2002

Microdissection is essential for gene expression profiling of clinically resected cancer tissues.

The gene expression array method enables us to achieve expression profiling with thousands of genes. Clinically resected bulk cancer tissues, however, contain not only cancer cells but also stromal cells, which may affect gene expression profiling and hamper accurate analysis of the cancer cells per se. Therefore, a procedure for dissecting specific cells, such as laser capture microdissection, is neededfor the clinical application of a gene expression array. There has been no study actually comparing 2 gene expression profiles, one obtained using RNA extractedfrom cancer cells by laser capture microdissection and one obtained using RNA extractedfrom bulk cancer tissues. Wefirst demonstrated the difference in expression patterns between them, without any amplification procedures. In addition, differential expression analysis between tumor and nontumor tissue yielded quite different patterns between the 2 methods. We conclude that microdissection is essential for gene expression profiling of clinical specimens.

Dissection↗
PubMed2003

Grade II astrocytomas are subgrouped by chromosome aberrations.

Grade II astrocytoma is defined as a low-grade tumor, yet patients have a wide range of survival and tumors can quickly progress to high-grade astrocytoma/glioblastoma. Previous studies using comparative genomic hybridization (CGH) failed to demonstrate frequent copy number aberrations (CNA) in these tumors. This may be related to technical difficulties because infiltrating astrocytic tumors are often intermixed with normal brain tissue. We developed methods to exclude most normal tissue and use small amounts of DNA for CGH by microdissecting small regions of tumor from paraffin sections and amplifying extracted DNA using degenerate oligonucleotide-primed polymerase chain reaction (DOP-PCR). Using this method, we examined 30 grade II astrocytoma cases. We found CNA in 25 cases (83%), with a mean of two CNA per case. The most frequent CNA were gains on 7q (12 cases), 5p (5 cases), 9 (5 cases), and 19p (3 cases), and losses on 19q (7 cases), 1p (6 cases), and Xp (3 cases). Gain on 7q and losses on 1p/19q were mutually exclusive. This is the first report on the genetic characterization of low-grade astrocytomas using CGH from microdissected and formalin-fixed tissue. The comparatively large number of cases in this study allows us to suggest that these tumors are genetically subgrouped.

Adolescent↗
PubMed2006

Galectin-1 in secondary alveolar septae of neonatal mouse lung.

In mice, alveolarization occurs during postnatal days 4 through 12, when secondary alveolar septae create thin-walled alveoli in the distal lung. We hypothesized that genes predominantly expressed in newly forming secondary alveolar septae influence the process of alveolarization. To address this hypothesis, tips of secondary alveolar septae were isolated from sections of postnatal day 6 mouse lung tissue using laser capture microdissection. Total RNA was isolated and amplified from the dissected alveolar septal tips and from intact postnatal day 6 lung tissue. Gene expression in the samples was characterized using Affymetrix mouse U74AN2 GeneChips. Galectin-1 was an abundantly expressed transcript that was enriched in the alveolar septal tips compared with levels in the whole lung tissue. Galectins are beta-galactoside-binding proteins involved in the regulation of cell proliferation, differentiation, and apoptosis in fibroblasts, muscle cells and endothelial cells, cell types that are present in the alveolar wall. Immunostaining in postnatal day 6 lung tissue confirmed that galectin-1 protein is concentrated in the tips of secondary alveolar septae, predominantly in myofibroblasts. Fibroblasts isolated from day 6 neonatal mouse lung tissue contained galectin-1 protein. Real-time PCR demonstrated that galectin-1 mRNA levels in mouse lung tissue peak at postnatal day 6. Immunoblot analysis confirmed that peak levels of lung galectin-1 protein are found at postnatal days 6 to 12. The increased expression of galectin-1 at the site and time of ongoing alveolarization in the newborn mouse is suggestive that galectin-1 may play an important role in this critical aspect of lung development.

Aging↗
PubMed1991

Interstitial cells of Cajal and Auerbach's plexus. A scanning electron microscopical study of guinea-pig small intestine.

Interstitial cells of Cajal (ICC) appear to be involved in the regulation of intestinal motility, probably as pacemaker cells. We investigated the complex organization of ICC associated with Auerbach's plexus of guinea-pig small intestine in the scanning electron microscope. The plexus was exposed by microdissection of zinc iodide/osmic acid stained tissue. After separation of the muscle layers by microdissection alone, the exposed Auerbach's plexus was seen to be covered by a smooth mat of reticular fibrils, thin enough to allow the detailed examination of the intact nerve plexus and interstitial tissue. ICC were distinguished as small, ovoid cell bodies from which 2-5 long, branching, roughly cylindrical processes emerge, associating to form a complex network. Characteristically, ICC processes participated in the formation of small bundles along their course, individual processes passing from one bundle to another. Cell bodies and processes of ICC were intimately associated with tertiary nerves of Auerbach's plexus. Axons were identified and distinguished these from ICC processes by their varicose structure and by th smaller diameters as compared with ICC processes. We found no single axons in our material. The characteristic morphology of ICC clearly distinguished these as a separate cell population different from neurons, glial cells, fibroblasts, and smooth muscle cells. After removal of the mat of reticular fibrils by chemical digestion the detailed organization of the interstitial tissue was preserved. Macrophage-like cells were previously demonstrated by other techniques to constitute a constant and rather dense population of cells in the studied location. As an indication that we preserve the full complement of interstitial cells by our technique, these macrophage-like cells wer for the first time identified in material processed for scanning electron microscopy. The cells had characteristically irregular cell surfaces with short, veil-like, folded extensions intertwined between the other cells in the interstices. Our study establishes an improved correlation between results obtained by the application of scanning electron microscopy to dissected tissue and results from light and transmission electron microscopy of the intact tissue.

Animals↗
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↗
PubMed2006

[Genetic heterogeneity for familial recurrent hydatidiform mole].

OBJECTIVE: To determine the parental origin of the genome in the molar pregnancies of two familes with familial recurrent hydatidiform mole (FRHM) and to investigate whether the gene responsible for FRHM is likely to be located within the 19q13.4 region in these familes. METHODS: The features of complete hydatidiform mole (CHM) were confirmed by pathological examination. DNA of CHM was prepared from sections of formalin-fixed paraffin-embedded blocks of molar tissue following laser capture microdissection. The polymerace chain reaction was used to amplify microsatellite polymorphisms in DNA from the patients, their husbands and the captured molar tissue. Parental contributions to the molar tissue were determined using ABI 310 GeneScan software. Genotyping and haplotype analysis of the candidate region on 19q13.4 was performed for members of both families using 25 microsatellite markers. RESULTS: One CHM from each family was identified as a biparental complete hydatidiform mole. All patients were heterozygous for most of the markers in the chromosome region of interest. In addition the two affected sisters in one of the families had different genotypes for the 19q13.4 region, suggesting that mutations in a different locus might be responsible for the disorder in this family. CONCLUSION: The location of the gene responsible for FRHM is unlikely to be located in the 19q13.4 chromosomal region in these two families suggesting that FRHM shows genetic heterogeneity.

Family Health↗
PubMed2004

Is gliomatosis peritonei derived from the associated ovarian teratoma?

Gliomatosis peritonei, a rare condition that occurs almost exclusively in the setting of ovarian immature teratoma, is characterized by the occurrence of nodules of mature glial tissues in the peritoneum. It is controversial whether glial tissues are derived from maturation of the associated teratomatous tissue that has implanted in the peritoneum, or glial differentiation of subperitoneal stem cells. In this study, we employed the unique genetic characteristics of ovarian teratomas (often with a duplicated set of maternal chromosomes and thus homozygous at many polymorphic microsatellite loci) versus normal tissues (heterozygous pattern due to presence of maternal and paternal genetic materials) to investigate the origin of gliomatosis peritonei. DNA samples were extracted from microdissected paraffin-embedded tissues, including the glial implants, the associated ovarian teratomas, and normal tissues, to determine their patterns of microsatellite loci in a multiplex polymerase chain reaction system. Two cases were not informative because the ovarian teratoma showed a heterozygous microsatellite pattern. In the 5 informative cases, the normal tissues showed a heterozygous pattern in the microsatellite loci, the associated teratomas showed a homozygous pattern, and the glial tissues showed a heterozygous pattern. Thus, gliomatosis peritonei is genetically unrelated to the associated teratoma but is probably derived from nonteratomatous cells, such as through metaplasia of submesothelial cells.

Female↗
PubMed2000

Concurrent and independent genetic alterations in the stromal and epithelial cells of mammary carcinoma: implications for tumorigenesis.

The high frequency of loss of heterozygosity (LOH) in epithelial cells of mammary ductal carcinoma in situ (DCIS) and IDC is a well known phenomenon, whereas the genetic abnormalities in the mammary stroma and its influence on the epithelial component have not been sufficiently studied. Using the PCR, we examined DNA extracts from microdissected stromal and epithelial tissues of 11 breast samples containing DCIS, including five cases associated with IDC. In each case, the mesenchymal tissue consisting of normal-appearing stroma at a distance from DCIS and IDC or stroma close to either DCIS or IDC was manually microdissected. Epithelial cells from morphologically clear-cut normal ducts and lobules, DCIS, and IDC were also microdissected. Twelve polymorphic DNA markers were tested to identify possible genetic alterations in the mesenchymal and epithelial cells on chromosomes 2p, 3p, 11q, 16q, and 17q. Samples from bilateral reduction mammoplasty from 10 women without any clinical, radiological, or pathological abnormalities were also selected as a control (reduction mammoplasty group). Whereas most cases (8/11, 73%) displayed at least one identical LOH in both epithelial and mesenchymal components, LOH at several loci was noted exclusively in stromal cells. The most frequent genetic alterations in the mesenchymal cells were at chromosomes 17q24, 16q23.1-24.2, 3p14.2, and 11q21-23.2, in 87.5, 62, 60, and 45% of informative cases, respectively. The LOH frequency in the stroma close to cancer ranged from 10 to 66.5% for DCIS and from 20 to 75% of informative cases for IDC. Furthermore, 10 of the 12 polymorphic markers revealed LOH in the stroma at a distance, ranging from 11 to 57% of informative cases. None of the control cases (women without any breast disease) revealed LOH either in the epithelial or in the stromal components. Our findings strongly support the concept of stromal-epithelial interaction in the development and progression of mammary neoplasia. Furthermore, this study suggests that genetic alterations in the stromal cells may precede genotypic changes in the epithelial cells. At least in some cases, the mammary stroma in DCIS or IDC apparently represents a neoplastic interactive component rather than a reactive response to the carcinoma. The frequent allelic loss (LOH) in the mammary stroma, identified in our study, may explain some of the fibroblastic abnormalities previously observed in patients with breast carcinoma or a variety of cancer-associated hereditary diseases. We conclude that the mammary stroma may play a key role in inducing neoplastic transformation of epithelial cells, recapitulating its role in normal mammary duct development.

Breast Neoplasms↗
PubMed2004

Laser capture microdissection analysis reveals frequent allelic losses in papillary urothelial neoplasm of low malignant potential of the urinary bladder.

BACKGROUND: In the 1999 World Health Organization classification system, papillary tumors of the urinary bladder were classified as papilloma, papillary urothelial neoplasm of low malignant potential (PUNLMP), and as Grade 1, Grade 2, and Grade 3 urothelial carcinoma. The biologic potential of PUNLMP of the urinary bladder is controversial. To the authors' knowledge, information regarding the genetic changes of PUNLMP tumors of the bladder is limited. METHODS: The authors examined loss of heterogygosity (LOH) at 5 polymorphic microsatellite markers on chromosome 9q32-33 (D9S177), 9p22 (IFNA), 17p13.1 (TP53), 12q14-24 (D12S1051), and 3p25-26 (D3S3050) from 26 patients who were diagnosed with PUNLMP tumors of the urinary bladder. Tumors were microdissected from sections prepared from formalin-fixed, paraffin-processed tissue specimens using laser capture microdissection. RESULTS: LOH was found in 21 of 26 (81%) patients with PUNLMP. The rate of LOH was 41% with D9S177, 32% with IFNA, 29% with TP53, 26% with D12S1051, and 44% with D3S3050. Allelic loss of multiple chromosome loci was often present in patients with PUNLMP tumors. CONCLUSIONS: Genetic changes that commonly occur in advanced bladder carcinoma (> or = pT2) are frequently found in PUNLMP of the urinary bladder.

Adult↗
PubMed1984

Comparison of tritiated thymidine and metaphase arrest techniques of measuring cell production in rat intestine.

Measurements of intestinal cell production at several sites throughout the gastrointestinal tract were compared using two different methods, namely tritiated thymidine to determine the uptake of tritium per unit weight of tissue (dpm/mg) and per microdissected intestinal crypt or stomach gland (dpm/crypt or gland) and the metaphase arrest technique, in the same group of rats. The metaphase arrest technique was employed to determine the crypt cell production rate per hour (CCPR). The dpm/crypt or gland of tritiated thymidine-derived tritium in microdissected intestinal crypts or stomach glands showed a good linear correlation (r = 0.93) with CCPR which extrapolated through the origin. The dpm/mg wet weight of tissue showed a good linear correlation with CCPR (r = 0.87) and dpm/crypt (r = 0.97); however, neither of these relationships extrapolated through the origin. Instead there was a positive intercept of dpm/mg tissue which represented about 25-30% of the maximal tritium content of the intestine. This radioactivity in tissue had no counterpart in the crypts or glands and presumably reflected unbound tritium and tritium in cells which were located outside the epithelial compartment. The good linear correlation (r = 0.93) between dpm/crypt and CCPR extended to the intestine of transected and 75% small bowel resected rats. Subsequent analysis of the times recorded for these procedures showed that determination of CCPR was faster by at least 25% than measurement of dpm/crypt. In conclusion, dpm/crypt but not dpm/mg tissue gave a valid estimate of intestinal cell production equivalent to measurement of CCPR.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
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↗
PubMed2005

Assessment of RET/PTC oncogene activation in thyroid nodules utilizing laser microdissection followed by nested RT-PCR.

Single palpable nodules of the thyroid gland are common in clinical practice; the majority of such lesions are benign. However, noninvasive thyroid nodules that exhibit borderline morphological signs of papillary cancer represent a diagnostic challenge. Rearrangements of the RET oncogene have been proposed as a marker for papillary thyroid cancer. In this chapter, methods for the analysis of the RET oncogene in laser microdissected papillary thyroid cancer tissue are described.

Biomarkers, Tumor↗
PubMed1983

Biochemical quantification of ATPase activities during liver carcinogenesis.

In the course of chemically induced liver carcinogenesis as one of the earliest changes, the histochemically demonstrable focal loss of nucleoside 5'-triphosphatase activities (ATPase) is detectable. The exact quantitation and differentiation of these alterations can be achieved by biochemical analysis in microdissected preneoplastic foci. The preparation of focal tissue was facilitated using a microscopic-microdissecting apparatus [1]. By microanalytic determination of hydrolytic cleavage of 32P from gamma 32P-ATP a decrease of total ATPase activity to about 70% was found. Furthermore, the alteration of ATPase activities in course of chemically induced liver carcinogenesis in rats will be described.

Adenosine Triphosphatases↗