Search PubMed⌕ Search

Biomedical subjects

A M Deshpande

Publications and source records attributed to A M Deshpande.

11 recordsLinked to original sources
PubMed2001

Intercistronic region required for polycistronic pre-mRNA processing in Caenorhabditis elegans.

In Caenorhabditis elegans, polycistronic pre-mRNAs are processed by cleavage and polyadenylation at the 3' ends of the upstream genes and trans splicing, generally to the specialized spliced leader SL2, at the 5' ends of the downstream genes. Previous studies have indicated a relationship between these two events in the processing of a heat shock-induced gpd-2-gpd-3 polycistronic pre-mRNA. Here, we report mutational analysis of the intercistronic region of this operon by linker scan analysis. Surprisingly, no sequences downstream of the 3' end were important for 3'-end formation. In contrast, a U-rich (Ur) element located 29 bp downstream of the site of 3'-end formation was shown to be important for downstream mRNA biosynthesis. This approximately 20-bp element is sufficient for SL2 trans splicing and mRNA accumulation when transplanted to a heterologous context. Furthermore, when the downstream gene was replaced by a gene from another organism, no loss of trans-splicing specificity was observed, suggesting that the Ur element may be the primary signal required for downstream mRNA processing.

Animals↗
PubMed2001

An approach to guideline implementation with GEM.

Implementation of practice guidelines refers to the creation of strategies and systems to operationalize the knowledge and recommendations set forth by guideline developers. We describe an approach to guideline implementation that makes direct use of the guideline document as a knowledge base. The Guideline Elements Model (GEM) provides an XML-based guideline document model that facilitates implementation of guidelines. Knowledge extraction using GEM requires document markup rather than programming and can promote authenticity and consistent knowledge encoding. Knowledge customization for the local enterprise requires addition of meta-information to pertinent components of the GEM hierarchy in a design database. GEM provides an audit trail to track local adaptation. Knowledge integration with patient data can be promoted using information management services. A design goal is to devise a system that can be applied by local clinical domain experts, quality assurance experts, and information systems programmers without requiring trained informaticians and knowledge engineers to serve as intermediaries

Artificial Intelligence↗
PubMed2001

A metadata framework for interoperating heterogeneous genome data using XML.

The rapid advances in the Human Genome Project and genomic technologies have produced massive amounts of data populated in a large number of network-accessible databases. These technological advances and the associated data can have a great impact on biomedicine and healthcare. To answer many of the biologically or medically important questions, researchers often need to integrate data from a number of independent but related genome databases. One common practice is to download data sets (text files) from various genome Web sites and process them by some local programs. One main problem with this approach is that these programs are written on a case-by-case basis because the data sets involved are heterogeneous in structure. To address this problem, we define metadata that maps these heterogeneously structured files into a common eXtensible Markup Language (XML) structure to facilitate data interoperation. We illustrate this approach by interoperating two sets of essential yeast genes that are stored in two yeast genome databases (MIPS and YPD).

Databases, Genetic↗
PubMed2000

Functional characterization of five eIF4E isoforms in Caenorhabditis elegans.

Recognition of the 5'-cap structure of mRNA by eIF4E is a critical step in the recruitment of most mRNAs to the ribosome. In Caenorhabditis elegans, approximately 70% of mRNAs contain an unusual 2,2,7-trimethylguanosine cap structure as a result of trans-splicing onto the 5' end of the pre-mRNA. The characterization of three eIF4E isoforms in C. elegans (IFE-1, IFE-2, and IFE-3) was reported previously. The present study describes two more eIF4E isoforms expressed in C. elegans, IFE-4 and IFE-5. We analyzed the requirement of each isoform for viability by RNA interference. IFE-3, the most closely related to mammalian eIF4E-1, binds only 7-methylguanosine caps and is essential for viability. In contrast, three closely related isoforms (IFE-1, IFE-2, and IFE-5) bind 2,2, 7-trimethylguanosine caps and are partially redundant, but at least one functional isoform is required for viability. IFE-4, which binds only 7-methylguanosine caps, is most closely related to an unusual eIF4E isoform found in plants (nCBP) and mammals (4E-HP) and is not essential for viability in any combination of IFE knockout. ife-2, ife-3, ife-4, and ife-5 mRNAs are themselves trans-spliced to SL1 spliced leaders. ife-1 mRNA is trans-spliced to an SL2 leader, indicating that its gene resides in a downstream position of an operon.

Amino Acid Sequence↗
PubMed1996

DNA replication fork pause sites dependent on transcription.

Replication fork pause (RFP) sites transiently arresting replication fork movement were mapped to transfer RNA (tRNA) genes of Saccharomyces cerevisiae in vivo. RFP sites are polar, stalling replication forks only when they oppose the direction of tRNA transcription. Mutant tRNA genes defective in assembly of transcription initiation complexes and a temperature-sensitive RNA polymerase III mutant (rpc160-41) defective in initiation of transcription do not stall replication forks, suggesting that transcription is required for RFP activity.

Base Sequence↗
PubMed1995

Effects of nitroxazepine on diastolic blood pressure in mild hypertensive patients--a short term clinical study.

In a double blind short term clinical study, nitroxazepine has been found to be superior over placebo in reducing the diastolic blood pressure in mild hypertensive patients. In short term open clinical trial design nitroxazepine (25 mg PO, HS) has been found to be superior and better tolerated than diazepam (5 mg PO, HS). In open clinical trial design, nitroxazepine (25 mg PO, HS) reduced the diastolic blood pressure to the target level (100 mm Hg and less) effectively controlling the uncontrolled hypertensive patients receiving maintenance dose of beta blockers. There was no such beneficial effect in patients receiving maintenance doses of other antihypertensive drugs (pilot study). Adverse drug reactions like disturbed sleep in one, uneasiness in 3, palpitation in one and dryness of mouth in one patient have been observed.

Adrenergic beta-Antagonists↗
PubMed1992

The ARS consensus sequence is required for chromosomal origin function in Saccharomyces cerevisiae.

Replication origins have been mapped to positions that coincide, within experimental error (several hundred base pairs), with ARS elements. To determine whether the DNA sequences required for ARS function on plasmids are required for chromosomal origin function, the chromosomal copy of ARS306 was deleted and the chromosomal copy of ARS307 was replaced with mutant derivatives of ARS307 containing single point mutations in domain A within the ARS core consensus sequence. The chromosomal origin function of these derivatives was assayed by two-dimensional agarose gel electrophoresis. Deletion of ARS306 deleted the associated replication origin. The effects on chromosomal origin function of mutations in domain A paralleled their effects on ARS function, as measured by plasmid stability. These results demonstrate that chromosomal origin function is a property of the ARS element itself.

Base Sequence↗