Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Tissue microdissection”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 397 records · Page 22Linked to original sources
PubMed2006

Enhanced catecholamine synthesis in the prefrontal cortex after traumatic brain injury: implications for prefrontal dysfunction.

Traumatic brain injury (TBI)--induced dysfunction of the prefrontal cortex causes many high-level cognitive deficits, including working memory (WM) dysfunction. WM lies at the core of many high-level functions, yet the cellular and molecular mechanisms underlying its dysfunction are poorly understood. Lesion and pharmacological studies in rodents have implicated the medial prefrontal cortex (mPFC), which includes the prelimbic/infralimbic (PL/IL) cortices, in WM tasks. These studies have shown that optimal levels of catecholamine neurotransmission are critical for normalcy of WM function, suggesting that alterations in their synthesis may play a role in WM dysfunction. Using the cortical impact injury model of traumatic brain injury which reproducibly causes working memory deficits in rodents, we have measured the protein levels and activity of tyrosine hydroxylase (TH), the rate-limiting enzyme for catecholamine biosynthesis, and tissue dopamine (DA) and norepinephrine (NE) levels in microdissected PL/IL tissues. Our results show that TBI increases TH protein levels, its activity and tissue DA and NE content in the PL/IL. These findings suggest that altered catecholamine signaling within the PL/IL may contribute to impaired PFC function, and may have implications in the design and implementation of strategies to alleviate prefrontal dysfunction in brain injury patients.

Animals↗
PubMed2006

Quantitative analysis of human telomerase reverse transcriptase in pancreatic cancer.

Although telomerase activity is a promising diagnostic marker, clinical introduction of this marker for cancer diagnosis is still problematic due to the lack of means of evaluating sample quality. Human telomerase reverse transcriptase (hTERT), one of the subunits of telomerase, is also a promising diagnostic marker. In the present study, we did large-scale analysis of 88 pancreatic juice samples to determine the feasibility of quantitative analysis of hTERT mRNA for diagnosis of pancreatic cancer. We found significant differences in hTERT expression among carcinoma-derived, intraductal papillary mucinous neoplasm (IPMN)-derived, and chronic pancreatitis-derived juice samples. Results showed that quantitative analyses of hTERT mRNAs are more useful in discriminating carcinoma from IPMN than from chronic pancreatitis. When the specificity was set at 100%, the sensitivity for differentiation between carcinoma and IPMN was 43.5%, whereas the sensitivity of cytologic examination was 22.0%. There were significant differences in hTERT expression among carcinoma cells, IPMN cells, and normal ductal cells isolated from pancreatic tissues by microdissection. Lymphocytes and hyperplastic epithelial cells isolated from tissues with the histologic appearance of pancreatitis showed various expression levels of hTERT. Our results suggest that quantitative analysis of hTERT mRNA in pancreatic juice is advantageous over cytologic analysis for differentiation between carcinoma and IPMN but probably not for differentiation between carcinoma and chronic pancreatitis.

DNA-Binding Proteins↗
PubMed2006

RCL2, a new fixative, preserves morphology and nucleic acid integrity in paraffin-embedded breast carcinoma and microdissected breast tumor cells.

Methacarn and RCL2, a new noncrosslinking fixative, were compared to formalin-fixed or frozen tissue samples of the same invasive breast carcinoma and were evaluated for their effects on tissue morphology and immunohistochemistry as well as DNA and RNA integrity. The histomorphology of methacarn- or RCL2-fixed paraffin-embedded tumors was similar to that observed with the matched formalin-fixed tissues. Immunohistochemistry using various antibodies showed comparable results with either fixative, leading to accurate breast tumor diagnosis and determination of estrogen and progesterone receptors, and HER2 status. Methacarn and RCL2 fixation preserved DNA integrity as demonstrated by successful amplification and sequencing of large DNA amplicons. Similarly, high-quality RNA could be extracted from methacarn- or RCL2-fixed paraffin-embedded MCF-7 cells, whole breast tumor tissues, or microdissected breast tumor cells, as assessed by electropherogram profiles and real-time reverse transcriptase-polymerase chain reaction quantification of various genes. Moreover, tissue morphology and RNA integrity were preserved after 8 months of storage. Altogether, these results indicate that methacarn, as previously shown, and RCL2, a promising new fixative, have great potential for performing both morphological and molecular analyses on the same fixed tissue sample, even after laser-capture microdissection, and can open new doors for investigating small target lesions such as premalignant breast lesions.

Breast Neoplasms↗
PubMed2000

BRCA2 is inactivated late in the development of pancreatic intraepithelial neoplasia: evidence and implications.

Patients harboring germline BRCA2 mutations are at an increased risk of developing pancreatic cancer. We investigated the prevalence of biallelic inactivation of BRCA2 in the presumed precursors to invasive pancreatic ductal carcinomas, pancreatic intraepithelial neoplasia (PanIN). Surgical resection specimens from three patients with germline BRCA2 mutations who developed pancreatic ductal adenocarcinoma were studied. Fourteen PanINs were needle-microdissected from paraffin-embedded tissue. DNA was isolated from these microdissected tissues and amplified by primer-mediated pre-amplification. Loss of heterozygosity at the BRCA2 locus was determined by polymerase chain reaction amplification and cycle sequencing. The presence of the wild-type alleles was evaluated at the nucleotide positions of the germline BRCA2 mutations. The K-ras gene was sequenced at codon 12 and 13 to confirm the efficacy of microdissection. By histological evaluation the prevalence of PanINs in these patients was not notably elevated. Loss of the wild-type allele of BRCA2 was present in one high-grade PanIN (PanIN 3), but in none of 13 low-grade PanINs (PanIN 1). In contrast, K-ras mutations were detectable in 7 of the 14 PanINs. These results suggest that biallelic inactivation of the BRCA2 gene is a relatively late event in pancreatic tumorigenesis. In contrast to classical molecular progression models of tumorigenesis, the inactivation of the wild-type allele in a carrier of a recessive tumor susceptibility gene may not always be the first somatic event during the molecular evolution of a cancer. The necessity for earlier genetic alterations before biallelic inactivation of a recessive tumor susceptibility gene such as BRCA2 may explain why affected carriers have normal numbers of neoplastic precursor lesions, a relatively low phenotypic penetrance, and late age of onset of pancreatic and other cancers.

BRCA2 Protein↗
PubMed2006

Corticotropin-releasing hormone receptor expression on normal and tumorous human adrenocortical cells.

Corticotropin-releasing hormone (CRH) is not only the principal regulator of the central hypothalamic-pituitary-adrenal (HPA) axis but also exerts direct actions on peripheral tissues. We analyzed the expression of CRH receptors in microdissected preparations of normal human adrenal glands and in adrenocortical and adrenomedullary tumors, employing immunohistochemistry, quantitative RT-PCR of microdissected adrenal tissues, and in situ hybridization. The effect of CRH on adrenal steroidogenesis was tested in adrenal cells. Immunoreactive CRH1R was found primarily within the zona reticularis. In addition, we found a higher expression of CRH type-1 and 2 receptors mRNAs in preparations of adrenal cortices as compared to pheochromocytomas, a 6-fold increase in preparations of clinically unapparent adrenocortical adenomas, and a 10- to 60-fold increase in cortisol-producing adrenal adenomas. Stimulation of the adrenal tumor cell line NCI-H295R with CRH elicited a 1.4-fold increase in DHEA secretion. This result could be reproduced in a culture of primary human adrenocortical cells. We conclude that adrenocortical cells exhibit a higher expression of functional CRH receptors than chromaffin cells and that CRH acts on adrenal DHEA production. The data support the assertion of a direct action of CRH on human adrenocortical cells in addition to an intra-adrenal CRH receptor/adrenocorticotropin system. Enhanced CRH1R expression may be involved in adrenocortical tumorigenesis.

Adrenal Cortex↗
PubMed2001

Identification of syt-ssx fusion transcripts in both epithelial and spindle cell components of biphasic synovial sarcoma in small tissue samples isolated by membrane-based laser microdissection.

In order to confirm the presence of SYT-SSX fusion gene in epithelial and spindle cell components of synovial sarcoma, we performed a nested reverse transcriptase-polymerase chain reaction (RT-PCR) using microbeam microdissection of membrane-mounted native tissue (MOMeNT) technique applied on formalin-fixed, paraffin-embedded tumor specimens from two biphasic synovial sarcomas and a control tissue of adamantinoma. Small targeted portions of either an epithelial or spindle cell component of the tumor tissue were microdissected together with the supporter membrane, by using an ultraviolet (337-nm) pulsed laser microbeam coupled into a robot-stage microscope with infinity optics. The SYT-SSX fusion transcript was detected in epithelial and spindle cell components of both biphasic synovial sarcomas, but not in the control tissue. Southern blot analysis also confirmed that the detected messages were derived from the SYT-SSX fusion gene. In conclusion, the microbeam MOMeNT is a useful method for isolating selected small portions from tissue sections. The SYT-SSX fusion gene is present in both cellular components of biphasic synovial sarcoma and is involved in oncogenesis of the synovial sarcoma rather than in morphologic epithelial differentiation. Therefore, in spite of the variable proportions of each component, our results confirm that the synovial sarcoma is of monoclonal origin.

Adult↗
PubMed1982

Angiogenesis induced by "normal" human breast tissue: a probable marker for precancer.

Normal human breast lobules, freshly isolated by precision microdissection of tissue stained with methylene blue chloride, were assayed for their ability to induce neovascularization (angiogenesis) in rabbit irises. Histologically, normal lobules from cancerous breast induced angiogenesis twice as often as lobules from noncancerous breasts, suggesting that preneoplastic transformation is diffuse.

Age Factors↗
PubMed2004

Microdissection genotyping of mixed glial and primitive neuroectodermal central nervous system neoplasm.

A 22-year-old man with previous radiation treatment for childhood astrocytoma underwent resection of a right parietooccipital lesion. Histopathology revealed a malignant neoplasm with areas of astrocytic and primitive neuroectodermal components. To resolve the relationship and cellular origin, representative tissue was microdissected from several targets, obtaining a balanced mixture of each element. Nonneoplastic brain parenchyma was separately microdissected to determine polymorphic marker informativeness and to serve as an internal negative control. Despite the relatively small quantity of tissue removed for each microdissection target, sufficient material was available for reliable, balanced, polymerase chain reaction-format genotyping encompassing a panel of tumor suppressor genes and genetic loci associated with these forms of neoplasia. The findings revealed distinct discordant genotypic profiles for each of the neoplastic components. The efficacy of the approach used for molecular analysis of this complex neoplasm and the implication of the genotypic findings are discussed.

Adult↗
PubMed2003

Piezo-power microdissection of mature human dental tissue.

Isolation of sufficient quantities of pure populations of odontoblasts from healthy and diseased teeth will facilitate our understanding of dentinogenesis during development and repair. Here we describe a novel Piezo-power microdissection (PPMD) technique for the isolation of pure populations of odontoblasts and pulpal tissue from formalin-fixed, paraffin-embedded, mature, healthy and carious human teeth. Odontoblasts and pulpal tissue gene expression were subsequently studied in ribonucleic acid isolated from PPMD preparations using a semi-quantitative reverse transcription polymerase chain reaction approach. Data confirmed that the genes for dentine sialophosphoprotein and Nestin are preferentially expressed in odontoblasts, whilst the genes for both collagen-1alpha and collagen-3alpha were expressed preferentially in pulpal tissue, particularly in carious samples. PPMD provides a novel and powerful approach to isolate pure populations of dental tissues and cells from fixed specimens for subsequent downstream molecular analyses.

Base Sequence↗
PubMed2006

Molecular profiling of laser-microdissected matched tumor and normal breast tissue identifies karyopherin alpha2 as a potential novel prognostic marker in breast cancer.

PURPOSE: The aim of the present study was to identify human genes that might prove useful in the diagnosis and therapy of primary breast cancer. EXPERIMENTAL DESIGN: Twenty-four matched pairs of invasive ductal breast cancer and corresponding benign breast tissue were investigated by a combination of laser microdissection and gene expression profiling. Differential expression of candidate genes was validated by dot blot analysis of cDNA in 50 pairs of matching benign and malignant breast tissue. Cellular expression of candidate genes was further validated by RNA in situ hybridization, quantitative reverse transcription-PCR, and immunohistochemistry using tissue microarray analysis of 272 nonselected breast cancers. Multivariate analysis of factors on overall survival and recurrence-free survival was done. RESULTS: Fifty-four genes were found to be up-regulated and 78 genes were found to be down-regulated. Dot blot analysis reduced the number of up-regulated genes to 15 candidate genes that showed at least a 2-fold overexpression in >15 of 50 (30%) tumor/normal pairs. We selected phosphatidic acid phosphatase type 2 domain containing 1A (PPAPDC1A) and karyopherin alpha2 (KPNA2) for further validation. PPAPDC1A and KPNA2 RNA was up-regulated (fold change >2) in 84% and 32% of analyzed tumor/normal pairs, respectively. Nuclear protein expression of KPNA2 was significantly associated with shorter overall survival and recurrence-free survival. Testing various multivariate Cox regression models, KPNA2 expression remained a highly significant, independent and adverse risk factor for overall survival. CONCLUSIONS: Gene expression profiling of laser-microdissected breast cancer tissue revealed novel genes that may represent potential molecular targets for breast cancer therapy and prediction of outcome.

Biomarkers, Tumor↗
PubMed1975

Nicotinamide adenine dinucleotide phosphate-converting enzymes and adenosine triphosphate citrate lyase in some tissues and organs of New Zealand obese mice with special reference to the enzyme pattern of the pancreatic islets.

In order to obtain a quantitative estimate of the capacity of the pancreatic islets for provision of cytoplasmic acetyl-coenzyme A and for the turnover of nicotinamide adenine dinucleotide phosphate and its reduced form (NADP+/NADPH), the following enzymes were assayed in islets taken from New Zealand Obese mice: adenosine triphosphate citrate lyase (EC 4.1.3.8), malate dehydrogenase (decarboxylating) (NADP+) (EC 1.1.1.40), glutathione reductase (EC 1.6.4.2) and isocitrate dehydrogenase (NADP+) (EC 1.1.1.42). In addition, the activity of isocitrate dehydrogenase (NAD+) (EC 1.1.1.41) was determined. For comparative purposes the activities in exocrine pancreas, liver, heart muscle, kidney cortex and skeletal muscle were also determined. Specimens of pancreatic islets and the other tissues were microdissected from freeze-dried sections. In comparison with the other tissues, adenosine triphosphate citrate lyase was particularly active in the islets. The NADP+/NAPH-converting enzymes had activities, which suggested a rapid turnover of the islet NADP+/NADPH pool.

ATP Citrate (pro-S)-Lyase↗
PubMed1996

Elevation of intracellular cAMP by noradrenaline and vasoactive intestinal peptide in striated ducts isolated from the rabbit mandibular salivary gland.

Salivary gland intralobular ducts are responsible for the modification of the electrolyte composition of the primary fluid secreted by the acini. However, the intracellular messengers that regulate this and other intralobular duct cell processes have not been fully characterized. To investigate the possibility that cAMP-mobilizing agonists may be involved, intralobular (striated) ducts were isolated from the rabbit mandibular salivary gland by tissue dissociation and microdissection and maintained in tissue culture overnight. Individual duct fragments were stimulated with the secretory agonists noradrenaline, vasoactive intestinal peptide (VIP) and substance P and their cAMP content measured by acetylated radioimmunoassay. Both noradrenaline and VIP elevated intracellular cAMP content concentration dependently, but substance P did not. The response to noradrenaline was blocked by the beta-adrenoceptor antagonist propranolol, but not by the alpha-adrenoceptor antagonist prazosin. Application of the VIP analogue [D-p-Cl-Phe6, Leu17]-VIP decreased the VIP-induced cAMP response. These results demonstrate that striated intralobular duct cells possess beta-adrenoceptors and peptidergic receptors that are coupled to adenylate cyclase and activated by noradrenaline and VIP, respectively. By elevating ductal cAMP content, these agonists may regulate both the electrolyte content of the primary saliva and the secretion of protein(s) from the ducts.

Adenylyl Cyclases↗
PubMed2004

Distribution of HLA class I altered phenotypes in colorectal carcinomas: high frequency of HLA haplotype loss associated with loss of heterozygosity in chromosome region 6p21.

HLA class I loss or down-regulation is a widespread mechanism used by tumor cells to avoid tumor recognition by cytotoxic T lymphocytes, and thus favor tumor immune escape. Multiple mechanisms are responsible for these HLA class I alterations. In different epithelial tumors, loss of heterozygosity (LOH) at chromosome region 6p21.3, leading to HLA haplotype loss, occurs in 6-50% of all cases depending on the tumor entity. In this paper we report the frequency of LOH at 6p21 in 95 colorectal carcinomas (CRC) previously analyzed for altered HLA class I expression with immunohistological techniques. We used PCR microsatellite amplification of selected STR markers located on Chromosome 6 to identify LOH with DNA from microdissected tumor tissues and the surrounding stroma. Sequence-specific oligonucleotide analysis was performed in microdissected stroma and tumor cells for HLA typing, and to detect HLA haplotype loss. A high frequency (40%) of HLA haplotype loss was found in CRC. Eight tumors showed microsatellite instability. We sometimes observed two or more mechanisms responsible for HLA alteration within the same HLA-altered phenotype, such as LOH and HLA class I total loss. In 25 tumors (26%) no HLA class I alteration could be identified. These data are potentially relevant for CRC patients undergoing T-cell-based immunotherapy.

Chromosomes, Human, Pair 6↗
PubMed2003

Laser microdissection and pressure catapulting (LMPC) in paraffin sections mounted on glass slides. A methodological report.

The technique of laser microdissection together with laser pressure catapulting (LMPC) is demonstrated in paraffin sections obtained from surgical specimens of brain tumors mounted on glass slides. A sufficient and precise application of microdissection techniques in tissue on glass slides is worthwhile, since it offers the possibility of a retrospective analysis of archived paraffin sections in histopathology. We could demonstrate a precise dissection of areas in tissues of different thicknesses (4 microm and 20 microm). Areas of tissue mounted directly on glass need to be dissected in a scanning mode in order to remove the total region in form of small tissue fragments row by row. This mode provided a precise microdissection of tissue areas of different sizes and shapes. A successful molecular biological analysis of the microdissected regions could be demonstrated. As an example for such an analysis, differential-PCR for detecting an amplification of the gene for the epidermal growth factor receptor (EGFR) was performed.

Central Nervous System Neoplasms↗
PubMed1986

Airway branching patterns influence asbestos fiber location and the extent of tissue injury in the pulmonary parenchyma.

The degree to which various anatomic components of the lung influence the distribution of inhaled particles is not entirely clear. Therefore, we have studied the role intrapulmonary airways play in the localization of respired asbestos fibers and have correlated local asbestos fiber burden with tissue injury in rats following exposure to aerosolized chrysotile asbestos for 7 hours per day, 5 days per week for 12 months. Tissues arising from anatomically distinct pathways of the tracheobronchial tree were isolated by using microdissection. Adjacent tissue blocks from regions immediately distal to the last dissected airway were prepared for light microscopic evaluation or digested in hypochlorite solution to determine alveolar septal tissue density and asbestos fiber concentration respectively. These studies demonstrated regional differences in asbestos fiber number, size, and mass which were inversely related to airway pathlength and to bifurcation number along each airway path. Fiber burden within each region was found to be proportional to the relative degree of tissue injury present. These findings suggest that differences in tissue injury from region to region in the lungs following exposure to asbestos are a result of regional differences in the deposition and retention of these substances in the lungs. These airway characteristics which influence fiber deposition may also play an important role in the deposition and subsequent lung injury caused by other particulates and environmental pollutants.

Animals↗
PubMed1983

Heterogeneous distribution of ATP citrate lyase in rat-liver parenchyma. Microradiochemical determination in microdissected periportal and perivenous liver tissue.

1. A radiochemical microtest was established for the determination of ATP citrate lyase in tissue samples of 0.2-1.0 micrograms dry weight. The specificity of this test system was guaranteed by its coenzyme A dependence as well as by inhibition of the activity measured in presence of a specific antibody. 2. Using this test system ATP citrate lyase activity was determined in microdissected periportal and perivenous liver tissue of fed, fasted and refed animals. The perivenous activity was 1.8-fold and 2.4-fold higher than the periportal one in fed male and female rats respectively. 3. The perivenous to periportal gradient was decreased during starvation-dependent reduction of the ATP citrate lyase activity. On the other hand it was not only restored but enhanced up to 2.8 after refeeding-dependent enhancement of the enzyme activity. 4. The predominance of the ATP citrate lyase activity in the perivenous, mainly glycolytic zone supports the hypothesis of the coordinate zonation of the carbohydrate and the lipid metabolism in the liver parenchyma.

ATP Citrate (pro-S)-Lyase↗
PubMed1991

Distribution of cyclic AMP phosphodiesterase in microdissected periportal and perivenous rat liver tissue with different dietary states.

Cyclic AMP phosphodiesterase was measured in liver homogenates and microdissected periportal and perivenous liver tissue from rats in different dietary states under different conditions of substrate saturation and effector stimulation. A radiochemical microtest, more sensitive by 2-3 orders of magnitude than the usual assay, was established for the determination of the activity in liver samples corresponding to 200-800 ng dry weight. At saturating cyclic AMP concentrations (46 microM) phosphodiesterase was homogeneously distributed within the liver acinus of fed rats. Starvation for 48 h led to a decrease in the overall activity and to a heterogenous distribution with slightly higher activities in the perivenous zone. At physiological cyclic AMP concentrations (1.8 microM) phosphodiesterase showed a flat zonal gradient in livers of fed rats with higher levels in the periportal zone; after 48 h starvation it was homogeneously distributed. In the presence of cyclic GMP (2 microM) the basal activity at physiological substrate concentrations was stimulated to a greater extent in the perivenous zone. This led to a homogeneous activity distribution in the fed state and to a heterogenous pattern with a slight perivenous maximum in the fasted state. Thus there was no or only a small zonal heterogeneity of signal transmitting enzymes such as cyclic AMP phosphodiesterase and glucagon-stimulated adenylate cyclase (Zierz and Jungermann 1984). This similar signal transducing capacity in the periportal and the perivenous area will contribute to maintain the zonation of signal input due to the hormone concentration gradients across the liver acinus.

1-Methyl-3-isobutylxanthine↗