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Biomedical subjects

A Turchin

Publications and source records attributed to A Turchin.

7 recordsLinked to original sources
PubMed2005

Severe hypercholesterolemia mediated by lipoprotein X in patients with chronic graft-versus-host disease of the liver.

We describe a series of cases of extreme hypercholesterolemia mediated by lipoprotein X in patients with chronic graft-versus-host disease of the liver after an allogeneic bone marrow transplant. All of the patients presented with a total cholesterol in excess of 1000 mg/dl (25.9 mmol/l). At the time they were also noted to have pseudohyponatremia. Cholesterol appeared to be predominantly carried by lipoprotein X. Intrahepatic cholestasis leading to reflux of bile lipoproteins into the bloodstream and subsequent formation of protein X appears to be the mechanism underlying this phenomenon. Complications, including retinal cholesterol thromboembolism and cholesteroloma of the lung have been seen in the patient with the highest cholesterol levels. Severe hypercholesterolemia is an important, and likely more common than previously reported, long-term complication of allogeneic hematopoietic stem cell transplantation. It is important for clinicians to familiarize themselves with the diagnostic and therapeutic challenges this condition presents.

Adult↗
PubMed1999

The primer generator: a program that facilitates the selection of oligonucleotides for site-directed mutagenesis.

Site-directed mutagenesis is a powerful tool that has enabled molecular biologists to perform functional analysis of altered nucleic acids and proteins. Newer PCR-based mutagenesis techniques have reduced the process of mutagenesis to as little as one day. While each technique has its advantages, both require a strategy to isolate the desired clone from a population that contains mutagenized and wild-type genes. In this report, we describe a World Wide Web-based computer program that facilitates the design of mutagenic primers such that successfully mutagenized clones can be identified by the presence or absence of a unique restriction site.

Amino Acid Sequence↗
PubMed1999

Active Learning Centre: utilization patterns of an interactive educational World Wide Web site.

The advent of the World Wide Web (WWW) provides unique opportunities to transform medical education. Interactive computer assisted instruction has shown promising results but its growth has been impeded by logistical barriers. We designed an interactive WWW site--Active Learning Centre (ALC)--that offers a novel approach to these problems, combining remotely authored databases with computer-generated self-assessment tests. This study analyzes utilization and user assessment of the site. The site was found to be patronized mostly by students and health professionals from English-speaking countries. Users have been pleased with their experience and suggest further expansion of the ALC. Our data have also tentatively shown that their knowledge improved with repeated visits to the site.

Attitude to Computers↗
PubMed1996

The generation of antibody diversity in the turtle.

The Ab response in reptiles has been studied at the protein level, and in turtles some aspects resemble those of cold-blooded vertebrates from other classes. The genetic bases for these features are not clear. The present study is the first on the IgH organization and complexity of a reptilian Ig gene system. The approach to cloning turtle (Pseudemys scripta) sequences is entirely PCR based, and its efficacy is demonstrated by obtaining extensive information on a heretofore unexplored Ig gene system. A number of genomic VH sequences, representing possibly four families, were isolated, as was a genomic C mu 4 clone. These sequences, used as probes, provided proof that in the turtle there is a single IgH locus with multiple VH genes and one C mu gene. In Northern hybridizations, the C mu 4 probe detected two transcripts; of the four VH groups, only one was expressed, and multiple bands indicated the presence of at least two non-mu transcripts. Using reverse transcription-PCR on spleen or liver RNA, an IgM heavy chain sequence was obtained, as were a number of VDJ rearrangements. Among 32 unique VDJ rearrangements from one animal, there were 22 sequence variants at framework 4, suggesting either a very large number of J segments or somatic modification in the variable region. The latter interpretation is supported by point mutations found in framework 3 and CDR3. The number of changes is considerably greater than the deduced Taq misincorporation rate (0.05%).

Amino Acid Sequence↗
PubMedDate not supplied

Situs inversus totalis and single coronary ostium: A coincidence or a pattern?

Situs inversus totalis and single coronary ostium are rare congenital anomalies, and no ontogenic connection has been described between them. Only three cases of association of single coronary ostium and situs inversus have been reported in the literature, all found on angiography. Here we present the first case of this association discovered at autopsy. Based on the apparently higher than expected frequency of this finding, an underlying pathologic connection between these conditions is proposed.

Adult↗
PubMedDate not supplied

Active Learning Centre: design and evaluation of an educational World Wide Web site.

OBJECTIVE: A new medium--World Wide Web (WWW)--has grown rapidly over the last few years. It provides opportunities for development of new educational tools and facilitates learning through interactivity, self-paced study and easy access. The aim of this project was to devise all educational WWW site (Active Learning Centre) that would take advantage of the capabilities of the new medium and assess its utilization by users. METHODS: Active Learning Centre provides customizable computer-generated feedback tests, searchable databases (currently Microbiology, Pharmacology, Vaccines, and Spanish-language Cardiovascular Medications), remote WWW-based database authoring, and multilingual support. Its modular architecture allows easy expansion into new areas of knowledge. To evaluate the Active Learning Centre we conducted a study evaluating utilization of the site and user feedback. RESULTS: The site is being used by thousands of patrons from around the world, the majority of whom are health professionals/health profession students from English-speaking countries. Customizable interactive tests are the most popular feature of the site. Most users give the site high ratings and would like it to expand further. CONCLUSION: The paradigm of combining interactive feedback tests with searchable % reference databases has been successful. Further expansion of the site to incorporate other areas of knowledge is planned.

Computer-Assisted Instruction↗