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Congenital dilatation of intrahepatic bile ducts associated with hepatic fibrosis and medullary sponge kidney--reconstruction and microdissection study.

An autopsy case of a four-year-old female with congenital dilatation of intrahepatic bile ducts with bilateral medullary sponge kidney is presented. The liver and kidney were investigated by reconstruction with serial sections and the kidney was also studied by microdissection. In this case the dilatations of collecting tubules and intra- and extrahepatic bile ducts were observed. We regard these lesions as developmental anomalies since these sites of both organs are excretory ducts derived from the endoderm. The liver cirrhosis observed at autopsy had developed in the course of the disease because the liver architecture was well preserved in the biopsy material. The patient had fatal cholangitis without cholelithiasis.

Bile Ducts, Intrahepatic↗

A semiautomated analysis method for catecholamines, indoleamines, and some prominent metabolites in microdissected regions of the nervous system: an isocratic HPLC technique employing coulometric detection and minimal sample preparation.

The application of a commercially available coulometric electrochemical detector to the automated HPLC analysis of some monoamines and their metabolites in microdissected areas of the rat nervous system is described. Apart from the stability and high sensitivity of the system, other appealing features of the technique are the facile sample preparation and long-term sample storage characteristics which show minimal analyte degradation. Basal values of some regional monoamine and metabolite concentration are listed together with a brief appendix that serves as a user's guide to the operation and maintenance of the detection system.

3,4-Dihydroxyphenylacetic Acid↗

Molecular analyses of mtDNA deletion mutations in microdissected skeletal muscle fibers from aged rhesus monkeys.

Mitochondrial DNA (mtDNA) deletion mutations co-localize with electron transport system (ETS) abnormalities in rhesus monkey skeletal muscle fibers. Using laser capture microdissection in conjunction with PCR and DNA sequence analysis, mitochondrial genomes from single sections of ETS abnormal fibers were characterized. All ETS abnormal fibers contained mtDNA deletion mutations. Deletions were large, removing 20-78% of the genome, with some to nearly all of the functional genes lost. In one-third of the deleted genomes, the light strand origin was deleted, whereas the heavy strand origin of replication was conserved in all fibers. A majority (27/39) of the deletion mutations had direct repeat sequences at their breakpoints and most (36/39) had one breakpoint within or in close proximity to the cytochrome b gene. Several pieces of evidence support the clonality of the mtDNA deletion mutation within an ETS abnormal region of a fiber: (a) only single, smaller than wild-type, PCR products were obtained from each ETS abnormal region; (b) the amplification of mtDNA from two regions of the same ETS abnormal fiber identified identical deletion mutations, and (c) a polymorphism was observed at nucleotide position 16103 (A and G) in the wild-type mtDNA of one animal (sequence analysis of an ETS abnormal region revealed that mtDNA deletion mutations contained only A or G at this position). Species-specific differences in the regions of the genomes lost as well as the presence of direct repeat sequences at the breakpoints suggest mechanistic differences in deletion mutation formation between rodents and primates.

Aged↗

Laser capture microdissection.

Laser capture microdissection (LCM) under direct microscopic visualization permits rapid one-step procurement of selected human cell populations from a section of complex, heterogeneous tissue. In this technique, a transparent thermoplastic film (ethylene vinyl acetate polymer) is applied to the surface of the tissue section on a standard glass histopathology slide; a carbon dioxide laser pulse then specifically activates the film above the cells of interest. Strong focal adhesion allows selective procurement of the targeted cells. Multiple examples of LCM transfer and tissue analysis, including polymerase chain reaction amplification of DNA and RNA, and enzyme recovery from transferred tissue are demonstrated.

Cell Separation↗

Microdissection of and microcloning from the short arm of human chromosome 2.

A bank of cloned DNA sequences from the distal half of the short arm of human chromosome 2 was generated by using microdissection and microcloning techniques. DNA was purified from 106 chromosomal fragments, manually dissected from peripheral lymphocytes in metaphase, and cloned into the EcoRI site of lambda gt10. A total of 257 putative recombinants were recovered, of which 41% were found to contain human inserts. The mean insert size was 380 base pairs (median size, 83 base pairs), and fewer than 10% of the clones contained highly repetitive sequences. All single-copy sequences examined were shown to map to the short arm of chromosome 2 by using hybrid panels. This technique provides a rapid method of isolating probes specific to a human subchromosomal region to generate linked markers to genetic diseases for which the chromosomal location is known.

Base Sequence↗

Technique for microdissection and measurement in biopsies of human small intestine.

A microdissection and measurement technique has been adapted for biopsy of human small intestine. Specimens fixed in alcohol and acetic acid are Schiff stained in bulk. Villi and crypts are then dissected out under a dissecting microscope, placed under a coverslip, examined, measured, and the number of mitoses in individual crypts counted. With this method specimens of normal small intestine have been found to have villi 500 microns to 1100 microns long and crypts 150 microns to 300 microns. These values were double those obtained when measuring sections of the same specimens stained with haematoxylin and eosin. The mean number of mitoses per crypt in normal duodenum and jejunum ranged from 1 to 12 and most of the cells in mitosis were in prophase or telophase. This rapid, sensitive, and inexpensive technique complements the available methods of measuring small intestinal architecture.

Biopsy↗

Delineation of a complex karyotypic rearrangement by microdissection and CGH in a family affected with split foot.

We report on a male patient and members of his family with additional material in chromosome 3. This derivative chromosome 3 was transmitted from his mother who had a complex rearrangement between chromosomes 2, 3, and 7. It was possible to delineate her chromosomal rearrangement by microdissection and reverse painting and to exclude these aberrations from being responsible for neonatal deaths and several abortions in this family. Two members of this family suffer from ectrodactyly or split hand/foot malformations (SHFM) of the feet which possibly correlates with the derivative chromosome 7 containing a breakpoint in the SHFM1 critical region involving several homeobox genes.

Chromosome Banding↗

Altered p53 in microdissected, metachronous, premalignant and malignant oral lesions from the same patients.

Aims-To determine whether mutant p53 alleles harboured by malignant tumours of the oral cavity were also present in previous premalignant lesions at the same site.Methods-Paraffin embedded tumour specimens along with their premalignant counterparts were analysed for p53 alterations using immunohistochemistry, microdissection, polymerase chain reaction amplification, and DNA sequencing.Results-Malignant lesions from five of eight patients showed overexpression of p53 protein by immunohistochemistry. Upon DNA sequencing, two of these five specimens had p53 mutations. Of the five patients whose cancers showed p53 overexpression by immunohistochemistry, three had previous premalignant lesions that also had immunohistochemically detectable p53 protein. However, DNA sequencing showed that none of these three had mutations in the p53 gene. The remaining five premalignant lesions had no immunohistochemically detectable p53 protein.Conclusions-Some premalignant lesions have increased p53 protein which can be detected by staining with antibody to p53. This staining is not caused by mutations in p53 that are found in subsequent tumours at the same site.

Journal Article↗

Microdissection of stained archival tissue.

In many tissues the preinvasive stage of neoplastic progression can be identified histologically as dysplasia or in situ disease. There is much interest in defining the molecular events associated with the early stages of neoplasia. Retrieval of histologically recognisable preinvasive neoplastic tissue uncontaminated by inflammatory or stromal cells is important for genetic studies using polymerase chain reaction (PCR) assay. A novel method for microdissection is described in which 10 microns sections are dewaxed, stained with haematoxylin and eosin, dried, covered with Sellotape, and the tissue cut out using a scalpel blade under direct visual control. The method is quick, eliminates problems of operator tremor, preserves the architecture of the micro-dissected tissue (for photographic documentation) and requires no special equipment. The presence of Sellotape and adhesive in the reaction mixture has no detrimental effect on the ability to extract DNA or to perform PCR.

Breast Neoplasms↗

Cloning and characterization of dispersed repetitive DNA derived from microdissected sex chromosomes of Rumex acetosa.

Rumex acetosa is characterized by a multiple chromosome system (2n = 12 + XX for females, and 2n = 12 + XY1Y2 for males), in which sex is determined by the ratio between the number of X chromosomes and autosome sets. For a better understanding of the molecular structure and evolution of plant sex chromosomes, we have generated a sex chromosome specific library of R. acetosa by microdissection. The screening of this library has allowed us to identify 5 repetitive DNA families that have been characterized in detail. One of these families, DOP-20, has shown no homology with other sequences in databases. Nevertheless, the putative proteins encoded by the other 4 families, DOP-8, DOP-47, DOP-60, and DOP-61, show homology with proteins from different plant retroelements, including poly proteins from Ty3-gypsy- and Ty1-copia-like long terminal repeat (LTR) retroelements, and reverse transcriptase from non-LTR retro elements. Results indicate that sequences from these 5 families are dispersed throughout the genome of both males and females, but no appreciable accumulation or differentiation of these types of sequences have been found in the Y chromosomes. These repetitive DNA sequences are more conserved in the genome of other dioecious species such as Rumex papillaris, Rumex intermedius, Rumex thyrsoides, Rumex hastatulus, and Rumex suffruticosus, than in the polygamous, gynodioecious, or hermaphrodite species Rumex induratus, Rumex lunaria, Rumex con glom er atus, Rumex crispus, and Rumex bucephalo phorus, which supports a single origin of dioecious species in this genus. The implication of these transposable elements in the origin and evolution of the heteromorphic sex chromosomes of R. acetosa is discussed.

Amino Acid Sequence↗

Repeated DNA sequences isolated by microdissection. I. Karyotyping of barley (Hordeum vulgare L.).

We report on microdissection, cloning and sequence, and Southern and fluorescence in situ hybridization (FISH) analysis of one moderately and one highly amplified repetitive DNA element, pHvMWG2314 and pHvMWG2315, respectively, isolated from barley (Hordeum vulgare L.) chromosome arm 3HL. The pHvMWG2315 sequence hybridizes to all 14 telomeric or subtelomeric regions of the barley chromosomes as determined by FISH. The 50 different hybridization sites that include intercalary signals allow the discrimination of all 14 chromosome arms and the construction of a kariotype of barley. The tandemly repeated subtelomeric element of 331 bp exists in all Triticeae species tested (H. vulgare, Agropyron elongatum, Secale cereale, Triticum tauschii, T. turgidum, and T. aestivum). It is AT rich (66%), exibits 84% sequence homology to subfragments of the D genome ¿specific¿ 1-kb element pAs1 of T. tauscii and 75% homology to interspersed genome-specific DNA sequence pHcKB6 from H. chilence. The repetitive sequence pHvMWG2314 is moderately amplified in barley and highly amplified in hexaploid wheat. The in situ experiments revealed no distinct signals on barley chromosomes, indicating a dispersed character for the sequence. The significance of the results for the identification of chromosomes and chromosome aberrations in FISH experiments are discussed.

Base Composition↗

Renal adrenergic receptors: localization of [125I]prazosin binding sites along the microdissected rat nephron.

Norepinephrine stimulates renal tubular sodium reabsorption, probably through an alpha 1-adrenoceptor-mediated mechanism. Although the distribution of alpha 1-adrenoceptors in the kidney has been studied with autoradiography, the precise location of these receptors in isolated nephron segments is unclear. Using a microassay we determined the specific binding of [125I]iodoarylazidoprazosin ([125I]prazosin), a high specific radioactivity analog of the selective alpha 1-antagonist prazosin, to microdissected glomeruli and tubule segments. Specific binding of [125I]prazosin (3 nM) in the proximal convoluted tubule was time- and concentration-dependent, saturable, and reversible. In this segment the apparent KD by association and dissociation rate constants of [125I]prazosin binding was 0.47 nM, and the maximum receptor density was approximately 0.19 fmol/mm, or 720 fmol/mg protein. Binding specificity was verified in competition studies with excess (3 microM) unlabeled prazosin and probes for alpha 2- (yohimbine), beta- (propranolol), dopamine1- (SCH23390), and dopamine2- (S-sulpiride) receptors. [125I]Prazosin binding was inhibited significantly only by unlabeled prazosin. Mapping of prazosin binding along the nephron revealed that the highest density was in the proximal convoluted tubule, followed by the proximal straight tubule. Lesser binding was found in the thick ascending limb and in the distal convoluted tubule, whereas in the cortical and outer medullary collecting duct and in glomeruli, binding was not significantly different from zero.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Laser microdissection of plant tissue: what you see is what you get.

Laser microdissection (LM) utilizes a cutting or harvesting laser to isolate specific cells from histological sections; the process is guided by microscopy. This provides a means of removing selected cells from complex tissues, based only on their identification by microscopic appearance, location, or staining properties (e.g., immunohistochemistry, reporter gene expression, etc.). Cells isolated by LM can be a source of cell-specific DNA, RNA, protein or metabolites for subsequent evaluation of DNA modifications, transcript/protein/metabolite profiling, or other cell-specific properties that would be averaged with those of neighboring cell types during analysis of undissected complex tissues. Plants are particularly amenable to the application of LM; the highly regular tissue organization and stable cell walls of plants facilitate the visual identification of most cell types even in unstained tissue sections. Plant cells isolated by LM have been the starting point for a variety of genomic and metabolite studies of specific cell types.

Chromosomes, Plant↗

Laser-assisted microdissection and real-time PCR detect anti-inflammatory effect of perfluorocarbon.

The aim of this study was to identify cell types involved in the anti-inflammatory effect of ventilation with perfluorocarbon in vivo. Fifteen anesthetized, surfactant-depleted piglets received either aerosolized perfluorocarbon (Aerosol-PFC), partial liquid ventilation (rLV) at functional residual capacity (FRC) volume (FRC-PLV), or intermittent mandatory ventilation (control). After laser-assisted microdissection of different lung cell types, mRNA expression of IL-8 and ICAM-1 was determined using TaqMan real-time PCR normalized to hypoxanthine phosphoribosyltransferase (HPRT). IL-8 mRNA expression (means +/- SE; control vs. Aerosol-PFC) was 356 +/- 142 copies IL-8 mRNA/copy HPRT mRNA vs. 3.5 +/- 1.8 in alveolar macrophages (P <0.01); 208 +/- 108 vs. 2.7 +/- 0.8 in bronchiolar epithelial cells (P <0.05); 26 +/- 11 vs. 0.7 +/- 0.2 in alveolar septum cells (P <0.01); 2.8 +/- 1.0 vs. 0.8 +/- 0.4 in bronchiolar smooth muscle cells (P <0.05); and 1.1 +/- 0.4 vs. 0.2 +/- 0.05 in vascular smooth muscle cells (P <0.05). With FRC-PLV, IL-8/HPRT mRNA expression was significantly lower in macrophages, bronchiolar epithelial, and vascular smooth muscle cells. ICAM-1 mRNA expression in vascular endothelial cells remained unchanged. Predominantly, alveolar macrophages and bronchiolar epithelial cells were involved in the inflammatory pulmonary process. The anti-inflammatory effect of Aerosol-PFC was most pronounced.

Animals↗

Alpha 2-adrenoceptor stimulation and cellular cAMP levels in microdissected rat glomeruli.

A functional role for the numerically predominant glomerular alpha 2-adrenoceptors is unknown. In other tissues, activation of alpha 2-adrenoceptors inhibits adenylate cyclase activity. We therefore examined the effect of alpha 2-adrenoceptor stimulation with (-)-epinephrine (E) on the cellular cAMP concentration in glomeruli isolated by microdissection. Parathyroid hormone (1-34 PTH), prostaglandin E2 (PGE2), histamine, serotonin, or adenosine, in the presence of 3-isobutyl-1-methylxanthine (phosphodiesterase inhibitor) and propranolol, was used to activate adenylate cyclase in single intact rat glomeruli. alpha 2-Adrenoceptors were activated with varying concentrations of E (37 degrees C, 2 min). In the presence of PTH-stimulated cAMP production, alpha 2-adrenoceptor activation with E (5 X 10(-7) to 5 X 10(-6) M) suppressed cellular cAMP levels in a dose-dependent fashion with the maximum at 30%. This suppression by E was inhibited by 5 X 10(-6) M yohimbine but not by 5 X 10(-6) M prazosin, confirming alpha 2-adrenoceptor mediation of this effect of E. Consistent with the above findings, the specific alpha 2-adrenoceptor agonist BHT933 inhibited PTH-stimulated cAMP accumulation. E also inhibited cAMP accumulation stimulated by serotonin. However, E did not suppress the PGE2-, histamine-, or adenosine-stimulated increase in cellular cAMP in the glomerulus. Activation of alpha 2-adrenoceptors inhibits cAMP formation stimulated by PTH or serotonin but not by PGE2, histamine, or adenosine in the rat glomerulus. Thus, the ability of alpha 2-adrenoceptors to inhibit adenylate cyclase appears to be hormone and probably function specific.

Adenosine↗

Aldose reductase activities in microdissected rat renal tubule segments.

Osmoregulation in inner medullary cells depends in part on cellular accumulation of sorbitol, the production of which from glucose is catalyzed by aldose reductase. To identify nephron segments that contain aldose reductase, we developed a fluorometric ultramicroassay to measure aldose reductase activity in microdissected nephron segments from collagenase-treated kidneys of Sprague-Dawley rats. DL-Glyceraldehyde (10 mM) was used as a substrate. Substantial aldose reductase activities were found in all three inner medullary renal tubule segments: thin descending limbs, thin ascending limbs, and inner medullary collecting ducts. Activity increased with depth into the inner medulla in all three segments. When aldose reductase activities were normalized by cell volume the activities in the three inner medullary segments were similar. Little or no aldose reductase activity was measured in glomeruli or any cortical or outer medullary nephron segment. Both proximal convoluted and proximal straight tubules were found to have a substantial capacity to reduce DL-glyceraldehyde, but the finding of greater reductase activity with D-glucuronate (10 mM) than with D-xylose (10 mM) indicated that the activity was due to aldehyde reductase. Sorbitol dehydrogenase (measured by a similar ultramicroassay method) was present in substantial amounts in proximal tubules, but not in inner medullary collecting ducts. The overall pattern of enzyme activities is consistent with the proposed osmoregulatory role for sorbitol in all three inner medullary renal tubule segments.(ABSTRACT TRUNCATED AT 250 WORDS)

Aldehyde Reductase↗

Glutamate dehydrogenase activities in microdissected rat nephron segments: effects of acid-base loading.

A method for measurement of glutamate dehydrogenase (GDH) activity in single renal tubules was employed to determine the distribution and regulation of GDH in tubule segments. Fresh microdissected tubules from collagenase-treated kidneys were permeabilized by hyposmotic shock and freezing. The rate of conversion of alpha-ketoglutarate, NH4+, and NADH to glutamate and NAD was measured at 37 degrees C fluorometrically. Very high activities were found in proximal tubule segments (150-210 pmol.min-1.mm tubule length-1), intermediate values (40-90 pmol.min-1.mm-1) in distal convoluted tubules, cortical thick ascending limbs, connecting tubules, medullary thick ascending limbs, and lower values (5-30 pmol.min-1.mm-1) in cortical collecting ducts, inner medullary collecting ducts, outer medullary collecting ducts, outer medullary thin limbs, and inner medullary thin limbs. To determine the effects of acid-base loading on GDH activity, 0.28 M NH4Cl (acid) or 0.28 M NaHCO3 (alkali) was added to the animals' drinking water for 7 days. Acid intake by the rats increased GDH activity in S1 and S2 proximal tubules by threefold, with no effect in other segments, including S3 proximal tubules. Alkali intake decreased GDH activity in the S3 proximal tubule by 40%, with no effect in other segments. We conclude that GDH activities are highest in proximal tubule segments and are regulated only in proximal tubule segments. Thus the results are consistent with the view that the proximal tubule is the chief site of the regulated production of ammonium in the kidney.

Acid-Base Imbalance↗

Quantitation of aquaporin-2 abundance in microdissected collecting ducts: axial distribution and control by AVP.

Aquaporin-2 (AQP-2) is the arginine vasopressin-regulated water channel of the renal collecting ducts. Using an improved version of a fluorescence-based enzyme-linked immunosorbent assay (Y. Maeda, B. L. Smith, P. Agre, and M. A. Knepper. J. Clin. Invest. 95: 422-428, 1995), we quantified AQP-2 protein abundance in microdissected renal collecting ducts from normal Sprague-Dawley (SD) rats and vasopressin-deficient Brattleboro rats. Standard curves were linear in the range of 0-200 fmol/well and were highly reproducible from day to day (lower limit of detection 2.3 fmol; coefficient of variation 6-9%). In SD rats thirsted for 24 h, the measured quantities of AQP-2 were as follows (x 10(9) molecules/mm): cortical collecting ducts (CCD), 4.3 +/- 0.5; outer medullary collecting ducts (OMCD), 10.1 +/- 1.7; initial one-third of inner medullary collecting duct (IMCD-1), 9.2 +/- 1.1; middle one-third of the IMCD (IMCD-2), 7.5 +/- 0.8; terminal one-third of the IMCD (IMCD-3), 3.3 +/- 0.6; n = 7-12. In IMCD-2 this corresponds to 11.8 +/- 1.3 x 10(6) AQP-2 molecules per cell. Thus AQP-2 is extremely abundant in collecting duct cells. AQP-2 levels were decreased in untreated Brattleboro rats relative to the parent strain Long-Evans (LE) by 68% in IMCD-2 and 44% in CCD. Following vasopressin infusion by osmotic minipumps, AQP-2 levels in IMCD-2 of Brattleboro rats rose gradually, reaching levels equivalent to those seen in LE rats after 5 days. A similar rise was seen in the CCD, indicating that the vasopressin-induced increase was not dependent on a large increase in the interstitial tonicity. Thus a rise in circulating vasopressin concentration increases the level of AQP-2 protein expression in collecting ducts, presumably via a direct action of vasopressin.

Animals↗