Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.1.26.9 (ribonuclease)
 6,589 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We searched for germ-line mutations of the APC gene in 79 unrelated patients with familial adenomatous polyposis using a ribonuclease protection analysis coupled with polymerase chain reaction amplifications of genomic DNA. Mutations were found in 53 patients (67%); 28 of the mutations were small deletions and 2 were 1- to 2-base-pair insertions; 19 were point mutations resulting in stop codons and only 4 were missense point mutations. Thus, 92% of the mutations were predicted to result in truncations of the APC protein. More than two-thirds (68%) of the mutations were clustered in the 5' half of the last exon, and nearly two-fifths of the total mutations occurred at one of five positions. This information has significant implications for understanding the role of APC mutation in inherited forms of colorectal neoplasia and for designing effective methods for genetic counseling and presymptomatic diagnosis.
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PMID:Germ-line mutations of the APC gene in 53 familial adenomatous polyposis patients. 131 10

The Turcot syndrome (TS) is a rare, probably autosomal recessive, disorder characterized by development of primary neuroepithelial tumors of the central nervous system (CNS) and numerous adenomatous colorectal polyps. To examine the possible involvement of mutations of the APC gene, which is responsible for familial adenomatous polyposis (FAP), in Turcot syndrome, we examined DNAs from TS patients for alterations in this gene by means of ribonuclease protection analysis. Germ-line APC mutations were detected in each of three unrelated cases of TS, and additional (somatic) mutations were observed in colonic adenomas that had developed in one of these patients. However, no somatic mutations in APC were found among 91 neuroepithelial tumors (medulloblastoma, glioblastoma, astrocytoma, and oligodendroglioma), whether sporadic or associated with TS. These results suggest that the APC gene is associated with pathogenesis of one feature of TS, but that at least one other gene is responsible for the genesis of neuroepithelial tumors in the CNS.
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PMID:Germ-line and somatic mutations of the APC gene in patients with Turcot syndrome and analysis of APC mutations in brain tumors. 751 58

The ribonuclease (RNase) protection assay (RPA) is an extremely sensitive technique used to determine specific mRNAs from cell and tissue extracts. The present protocol presents detailed procedures for a conventional RPA using antisense RNA probes purified with a Fullengther apparatus. The Fullengther has the advantage of being a relatively quick and safe procedure compared to more conventional methods for purification of full-length RNA probes. Using this protocol, we sought to simultaneously determine multiple mRNA species, including splice variants of the type I receptor (PAC(1)) of pituitary adenylate cyclase-activating polypeptide (PACAP), an important mediator in the regulation of luteinizing hormone-releasing hormone (LHRH) synthesis by ovarian steroids such as progesterone [7]. PAC(1) has more than eight splice variants. We have been able to discriminate the hop1 variant from other splice variants. To improve our understanding of the regulation mechanism of genes that are related to each other, such as LHRH and PACAP, it is most important to simultaneously determine genes that are involved in the same physiological areas of regulation. Using only 5 microg of total RNA sample from a single rat preoptic area, we simultaneously determined five different transcripts, including four rare mRNA species such as LHRH, PACAP, and hop1 variant and other splice variants of PAC(1), as well as the internal control of cyclophilin mRNA. This protocol provides a method for the simultaneous determination of multiple transcripts using the RPA.
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PMID:Simultaneous determination of multiple transcripts and splice variants of a primary transcript using ribonuclease protection assays. 1143 Nov 30

An approach in tissue engineering of heart valves is the use of decellularized xenogeneic matrices to avoid immune response after implantation. The decellularization process must preserve the structural components of the extracellular matrix to provide a biomechanically stable scaffold. However, it is known that in vascular lesions platelet adhesion to extracellular matrix components occurs and platelet activation is induced. In the present study we examined the effects of a decellularized porcine heart valve matrix on thrombocyte activation and the influence of re-endothelialisation in vitro. Porcine pulmonary conduits were decellularized using Triton X-100, Na-deoxycholate and Igepal CA-630 followed by a ribonuclease digestion. Cryostat sections of decellularized heart valves with and without seeding with human umbilical vein endothelial cells (HUVEC) were incubated with platelet rich plasma. Samples were either stained with fluorescent antibodies for CD41 and PAC-I (recognizing the activated fibrinogen receptor) or fixed with glutaraldehyde. Thereafter, the samples were processed for laser scanning microscopy (LSM) or scanning electron microscopy (SEM). Examination by LSM showed numerous platelets with co-localized staining for CD41 and PAC-1 on the nonseeded decellularized heart valve matrix whereas after seeding with endothelial cells no platelet activation was detected. SEM revealed platelet adhesion and aggregate formation only on the surface of the non-seeded or partially denuded matrix specimens. We show in this study that the decellularized porcine matrix acts as a platelet-activating surface. Seeding with endothelial cells effectively abolishes the platelet adhesion and activation and therefore is necessary to eliminate thrombogenicity in tissue engineered heart valves.
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PMID:The decellularized porcine heart valve matrix in tissue engineering: platelet adhesion and activation. 1626 58

In this work, the in vitro tests of biological activity of benzimidazoles were conducted. This group of benzimidazole derivatives was evaluated as potential bioreductive agents and their characteristic pro-apoptosis activity and cell cycle interruption on the human lung adenocarcinoma A549 cells were discussed. Their toxicity on the healthy human erythrocytes and their influence on the healthy human erythrocytes acetylcholinesterase enzyme (AChE) were established. Their apoptosis activity on A549 cells line was determined by Annexin V-APC test, and it was visualized by Hoechst test. In the next stage, their influence on the cell cycle interruption was determined by using the ribonuclease reagent. The AChE inhibition test was defined by the Ellman method, and the red blood cell lysis was defined by erythrotoxicity test. The results proved the pro-apoptosis properties of all tested compounds in normoxia and hypoxia. The DNA content assay showed that the benzimidazoles possess the ability to interrupt S phase of tumor cell cycle. The best activity in this action was presented by compound 1, especially in hypoxia, and it proves that the N-oxide analogs are predispositioned to the hypoxic target. In this study, the benzimidazoles were found as potentially biocompatible and their inhibition of acetylcholinesterase was lower than tirapazamine and much lower than tacrine which constitutes their desired effect of potential biological activity.
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PMID:Biological evaluation of the toxicity and the cell cycle interruption by some benzimidazole derivatives. 2703 17