PubMed Health⌕ Search

Biomedical subjects

D M Schuster

Publications and source records attributed to D M Schuster.

16 recordsLinked to original sources
PubMed1998

One possible future.

Explore the source record for details and available documents.

Complementary Therapies↗
PubMed1998

The use of the diagnostic radionuclide ascites scan to facilitate treatment decisions for hepatic hydrothorax.

A 44-year-old man had an intractable right-sided pleural effusion due to cirrhosis, despite the absence of abdominal ascites. Instillation of Tc-99m macroaggregated serum albumin under CT guidance into the peritoneal space demonstrated transdiaphragmatic communication. This finding indicated the necessity for decompressing the portal system to treat the hydrothorax. The diagnostic radionuclide ascites scan may play an important role in the treatment approach to such patients.

Abdomen↗
PubMed1997

Effective amplification of 20-kb DNA by reverse transcription PCR.

Polymerase chain reaction has been applied to the amplification of long DNA fragments from a variety of sources, including genomic, mitochondrial, and viral DNAs. However, polymerase chain reaction amplification from cDNA templates produced by reverse transcription has generally been restricted to products of less than 10 kilobases. In this paper, we report a system to effectively amplify fragments up to 20 kilobases from human coronavirus 229E genomic RNA. We demonstrate that the integrity of the RNA template and the prevention of false priming events during reverse transcription are the critical parameters to achieve the synthesis of long cDNAs. The optimization of the polymerase chain reaction conditions enabled us to improve the specificity and yield of product but they were not definitive. Finally, we have shown that the same reverse transcription polymerase chain reaction technology can be used for the amplification of extended regions of the dystrophin mRNA, a cellular RNA of relatively low abundance.

Base Sequence↗
PubMed1996

Archaebacterial DNA polymerases tightly bind uracil-containing DNA.

We show that archaebacterial DNA polymerases are strongly inhibited by the presence of small amounts of uracil-containing DNA. Inhibition appears to be competitive, with the DNA polymerase exhibiting approximately 6500-fold greater affinity for binding the inhibitor than a DNase I-activated DNA substrate. All six archaebacterial DNA polymerases tested were inhibited, while no eubacterial, eukaryotic, or bacteriophage enzymes showed this effect. Only a small inhibition resulted when uracil was present as the deoxynucleoside triphosphate, dUTP. The rate of DNA synthesis was reduced by approximately 40% when dUTP was used in place of dTTP for archaebacterial DNA polymerases. Furthermore, an incorporated dUMP served as a productive 3'-primer terminus for subsequent elongation. In contrast, the presence of an oligonucleotide containing as little as a single dUrd residue was extremely inhibitory to DNA polymerase activity on other primer-template DNA.

Archaea↗
PubMed1996

The integrative hospital explored via acupuncture.

To integrate complementary and allopathic medicine within a single hospital requires close attention to models of health care delivery, economics, and medical philosophy. The practice of acupuncture can be used as a heuristic device to examine these issues and how solutions may apply to other complementary modalities in the creation of such a hospital facility.

Acupuncture Therapy↗
PubMed1995

Hospital 2000: the interface of radiology within a combined "complementary-allopathic" medicine framework.

The field of radiology can play a crucial role in the movement beyond allopathic and complementary medicine to a true combination approach. Radiologists are proponents of minimal invasiveness and are familiar with the overreliance on diagnostic imaging tests. Their experience can be used to design appropriate applications for technology and to plan research methods to explore the questions raised by a combination medicine paradigm.

Clinical Medicine↗
PubMed1993

Selective RNA amplification: a novel method using dUMP-containing primers and uracil DNA glycosylase.

The application of PCR to a wide variety of biological problems and molecular techniques has gained wide acceptance. RNA-PCR, a technique in which first-strand cDNA synthesis is followed by PCR amplification, has enabled detection and characterization of rare transcripts. One problem confronting the researcher involves specific amplification of transcribed sequences in the presence of small amounts of genomic DNA of identical sequence. We describe a novel technique, selective RNA amplification, which will specifically amplify RNA sequences in a background of homologous DNA. The method involves first-strand cDNA synthesis from a specific dUMP-containing oligonucleotide that contains unique user-defined 5' sequence (adapter sequence) not found in the message of interest. RNA template is degraded using RNase H, which is specific for RNA/DNA hybrids. This is followed by second-strand synthesis using a gene-specific primer (GSP). The original adapter primer is digested with uracil DNA glycosylase (UDG) to prevent its participation in subsequent amplification. PCR is then performed using the GSP and a second primer corresponding to the unique adapter sequence. In this paper, we apply this method to the amplification of RNA derived from human papilloma virus sequences. Using Southern analysis, we demonstrate specific amplification of 10(5) molecules of an in vitro-transcribed RNA. Denatured DNA of identical sequence and concentration was not amplified using the RNA-specific method. The method could eliminate the need for stringent purification of RNA and enables amplification of rare messages from RNA preparations containing homologous DNA of identical sequence and size.

Base Sequence↗
PubMed1992

Uracil DNA glycosylase-mediated cloning of polymerase chain reaction-amplified DNA: application to genomic and cDNA cloning.

A simple and rapid method for cloning of amplification products directly from the polymerase chain reaction (PCR) has been developed. The method is based on the addition of a 12-base dUMP-containing sequence (CUACUACUACUA) to the 5' end of PCR primers. Incorporation of these primers during PCR results in the selective placement of dUMP residues into the 5' end of amplification products. Selective degradation of the dUMP residues in the PCR products with uracil DNA glycosylase (UDG) disrupts base pairing at the termini and generates 3' overhangs. Annealing of 3' protruding termini to vector DNA containing complementary 3' ends results in chimeric molecules which can be transformed, with high efficiency, without in vitro ligation. Directional cloning of PCR products has also been accomplished by incorporating different dU-containing sequences at the end of each PCR primer. Substitution of all dT residues in PCR primers with dU eliminates cloning of aberrant "primer dimer" products and enriches cloning of genuine PCR products. The method has been applied to cloning of inter-Alu DNA sequences from human placental DNA. Using a single primer, DNA sequences between appropriately oriented Alu sequences were amplified and cloned. Cloning of cDNA for the glyceraldehyde-3'-phosphate dehydrogenase gene from rat brain RNA was also demonstrated. The 3' end region of this gene was amplified by the 3' RACE method and the amplified DNA was cloned after UDG digestion. Characterization of cloned DNAs by sequence analysis showed accurate repair of the cloning junctions. The ligase-free cloning method with UDG should prove to be a widely applicable procedure for rapid cloning of PCR-amplified DNA.

Animals↗
PubMedDate not supplied

Magnetic resonance cholangiography.

Magnetic resonance cholangiography (MRC) can be performed with data from a routine imaging protocol, without the need for additional pulse sequences or special equipment. We studied three patients with obstructive jaundice who underwent magnetic resonance imaging (MRI) of the liver. T2-weighted fat suppressed fast spin-echo sequences were processed with a maximum intensity projection algorithm to create three-dimensional images of the dilated portions of the biliary tree. Results were correlated with endoscopic retrograde cholangiopancreatography and computed tomography. These images compared favorably with those acquired on scanners in which special breath-holding gradient echo protocols are used.

Aged↗
PubMedDate not supplied

Patients with an implanted cardioverter defibrillator: a new challenge.

The AICD has become the "gold standard" of tachydysrhythmia management. Since its approval in October 1985, nearly 12,000 patients have been implanted with the device (statistic from Cardiac Pacemakers, Inc., February 15, 1990). The use of this device is expected to increase for patients who are at risk for sudden cardiac death. Future device technology is advancing rapidly with the addition of more programmable options, such as shock energy output and a programmable delay feature for nonsustained VT patients. Both of these options currently are incorporated into a clinical investigational device, the VENTAKP. The emergency nurse must be aware of the device's specific operation and be prepared to interact safely and effectively to assist the AICD patient.

Electric Countershock↗