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David Jaffe

Publications and source records attributed to David Jaffe.

6 recordsLinked to original sources
PubMed2006

Effect of switching to tenofovir with emtricitabine in patients with chronic hepatitis B failing to respond to an adefovir-containing regimen.

BACKGROUND: In patients with chronic hepatitis B, long-term use of lamivudine is limited by resistance mutations. Adefovir dipivoxil has a very low rate of resistance, but there have been recent reports describing resistance mutations. Tenofovir disoproxil fumarate and emtricitabine show potent activity against wild-type and lamivudine-resistant hepatitis B virus. METHODS: We describe a series of seven HIV-seronegative patients who failed to achieve undetectable hepatitis B viral DNA on adefovir. No lamivudine resistance testing was performed. The antiviral regimen was changed to tenofovir (300 mg daily) and emtricitabine (200 mg daily). Variables collected included levels of hepatitis B viral DNA by polymerase chain reaction, alanine and aspartate aminotransferase, hepatitis B e antigen and hepatitis B e antibody. RESULTS: The median hepatitis B viral DNA level while on adefovir was 430,000 copies/ml with a median fall in hepatitis B viral DNA levels of 2.0 log10 copies/ml. Patients were on adefovir for a median period of 10 months before a change in regimen to tenofovir and emtricitabine. This regimen change resulted in a median fall in hepatitis B viral DNA levels of 3.0 log10 copies/ml (range, 2-4) after a median treatment duration of 23 months (range, 14-28). All patients (100%) had achieved undetectable hepatitis B viral DNA levels following combination therapy. Anti-hepatitis B e seroconversion occurred in one patient. No change in serum creatinine was observed during therapy, and no significant adverse events were reported. CONCLUSIONS: In patients failing to respond to adefovir monotherapy or an adefovir-containing regimen for chronic hepatitis B virus, a combination of tenofovir and emtricitabine resulted in undetectable hepatitis B viral DNA levels without any renal toxicity. Tenofovir, in combination with emtricitabine, may be an alternative treatment for those with detectable hepatitis B viral DNA on adefovir.

Adenine↗
PubMed2005

Benign cutaneous pseudoglandular schwannoma: a case report.

Schwannoma is a common peripheral neural neoplasm that could present as a primary skin lesion. In addition to typical schwannoma with classic Antoni A and Antoni B areas, many variant types have been described, such as plexiform, cellular, epithelioid, and ancient schwannomas. Glandular schwannoma is a rare variant characterized by the presence of glands in an otherwise typical schwannoma. There are also a few reported cases in the literature of pseudoglandular schwannoma from central nervous system, eye, submandible, and shoulder, in which the gland-like structures were lined by Schwann cells. We report here a patient with a benign cutaneous schwannoma composed of predominantly gland-like spaces that contained mucinous material and were lined by Schwann cells confirmed by immunohistochemistry and ultrastructural studies. The tumor was well circumscribed and showed minimal cytologic atypia, indicating benignity. We report this unusual case of benign cutaneous pseudoglandular schwannoma to further awareness of the morphologic diversity of schwannoma.

Female↗
PubMed2004

Genome duplication in the teleost fish Tetraodon nigroviridis reveals the early vertebrate proto-karyotype.

Tetraodon nigroviridis is a freshwater puffer fish with the smallest known vertebrate genome. Here, we report a draft genome sequence with long-range linkage and substantial anchoring to the 21 Tetraodon chromosomes. Genome analysis provides a greatly improved fish gene catalogue, including identifying key genes previously thought to be absent in fish. Comparison with other vertebrates and a urochordate indicates that fish proteins have diverged markedly faster than their mammalian homologues. Comparison with the human genome suggests approximately 900 previously unannotated human genes. Analysis of the Tetraodon and human genomes shows that whole-genome duplication occurred in the teleost fish lineage, subsequent to its divergence from mammals. The analysis also makes it possible to infer the basic structure of the ancestral bony vertebrate genome, which was composed of 12 chromosomes, and to reconstruct much of the evolutionary history of ancient and recent chromosome rearrangements leading to the modern human karyotype.

Animals↗
PubMed2003

The genome sequence of the filamentous fungus Neurospora crassa.

Neurospora crassa is a central organism in the history of twentieth-century genetics, biochemistry and molecular biology. Here, we report a high-quality draft sequence of the N. crassa genome. The approximately 40-megabase genome encodes about 10,000 protein-coding genes--more than twice as many as in the fission yeast Schizosaccharomyces pombe and only about 25% fewer than in the fruitfly Drosophila melanogaster. Analysis of the gene set yields insights into unexpected aspects of Neurospora biology including the identification of genes potentially associated with red light photobiology, genes implicated in secondary metabolism, and important differences in Ca2+ signalling as compared with plants and animals. Neurospora possesses the widest array of genome defence mechanisms known for any eukaryotic organism, including a process unique to fungi called repeat-induced point mutation (RIP). Genome analysis suggests that RIP has had a profound impact on genome evolution, greatly slowing the creation of new genes through genomic duplication and resulting in a genome with an unusually low proportion of closely related genes.

Calcium Signaling↗
PubMed2002

Academic dilemmas.

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Career Mobility↗