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Biomedical subjects

J Woolford

Publications and source records attributed to J Woolford.

10 recordsLinked to original sources

Long-Term use of rivastigmine in patients with dementia with Lewy bodies: an open-label trial.

Patients with dementia with Lewy bodies (DLB) have progressive deficits in cognition, parkinsonism, and neuropsychiatric symptoms. Cholinesterase inhibitors have been used to ameliorate cognitive decline and neuropsychiatric symptoms in short-term trials. In this study, patients with DLB were treated with rivastigmine up to 96 weeks. Improvement from baseline was seen in cognitive function as measured by the Mini-Mental State Examination (MMSE), and neuropsychiatric symptoms as measured by the Neuropsychiatric Inventory (NPI) over the first 24 weeks of treatment. By 96 weeks, neither the MMSE scores nor the NPI scores were significantly worse than at baseline.

Aged↗

Chloroplast encoded thioredoxin genes in the red algae Porphyra yezoensis and Griffithsia pacifica: evolutionary implications.

A gene encoding a thioredoxin protein was identified in the chloroplast genome of the rhodophyte Porphyra yezoensis. The P. yezoensis trxA gene contains 324 bp and is transcribed into a 0.7 kb messenger RNA. Analysis of the transcription start site demonstrates that canonical chloroplast -10 and -35 sequences are not present. The deduced amino acid sequence of the thioredoxin gene from the red algae has the greatest similarity to type m thioredoxins, providing strong support for the hypothesis that type m thioredoxins in photosynthetic eukaryotes originated from an engulfed bacterial endosymbiont. Hybridization analysis of nuclear and chloroplast DNAs from several members of the phyla Chromophyta and Rhodophyta using P. yezoensis DNA as a probe demonstrated strong hybridization to the chloroplast and nuclear genomes of Griffithsia pacifica and a weak cross-hybridization to the chromophyte P. foliaceum. The G. pacifica chloroplast gene has a 66% identity with the P. yezoensis DNA, contains conserved active site amino acid residues, but lacks a methionine start codon.

Amino Acid Sequence↗

Activation of the feline c-fms proto-oncogene: multiple alterations are required to generate a fully transformed phenotype.

The v-fms oncogene is capable of producing tumors in vivo and transforming cells in culture; in contrast, the c-fms proto-oncogene is nontransforming. In this report we present the complete nucleotide sequence of a feline c-fms cDNA, the progenitor of the v-fms oncogene. Comparison of this sequence with that of v-fms shows that the proteins encoded by these two genes differ by nine amino acid substitutions and the replacement of 50 C-terminal amino acids present in c-fms by 11 unrelated residues in v-fms. Using chimeric fms genes and site-directed mutagenesis, we have determined that the C-terminal modification present in v-fms is sufficient to generate a partially transforming phenotype, but that mutations at amino acid positions 301 and 374 are required (in addition to the C-terminal modification) to generate a fully transforming fms gene.

Amino Acid Sequence↗

pp60c-src has less affinity for the detergent-insoluble cellular matrix than do pp60v-src and other viral protein-tyrosine kinases.

A difference in affinity for a Nonidet P-40-insoluble cellular matrix was observed between the products of the viral and cellular src genes. It has previously been demonstrated that pp60v-src is associated with a detergent-insoluble matrix containing the cellular cytoskeleton (J. G. Burr, G. Dreyfuss, S. Penman, and J. M. Buchanan, Proc. Natl. Acad. Sci. USA 77:3484-3488, 1980). We observed a similar association of the transforming proteins of Fujinami sarcoma virus (P130gag-fps) and Yamaguchi 73 avian sarcoma virus (P90gag-yes), both of which are tyrosine-specific protein kinases. However, we found that the endogenous c-src product, pp60c-src, was not tightly bound to the detergent-insoluble matrix. This does not appear to have been due to differences in the cytoskeleton between transformed and nontransformed cells since pp60c-src was also solubilized by nonionic detergent in cells transformed by Rous sarcoma virus. This difference in the affinities of the v-src and c-src products for cytoskeletal proteins may contribute to the inability of pp60c-src to transform cells.

Avian Sarcoma Viruses↗

Characterization of the human c-fms gene product and its expression in cells of the monocyte-macrophage lineage.

The McDonough strain of feline sarcoma virus contains an oncogene called v-fms whose ultimate protein product (gp140v-fms) resembles a cell surface growth factor receptor. To identify and characterize the protein product of the proto-oncogene c-fms, antisera were prepared to the viral fms sequences and used to detect specific cross-reacting sequences in human choriocarcinoma cells (BeWo) known to express c-fms mRNA. Both tumor-bearing rat sera and a rabbit antiserum prepared to a segment of v-fms expressed in Escherichia coli detected a 140-kilodalton (kDa) glycoprotein in the BeWo cells. Tryptic fingerprint analysis of [35S]methionine-labeled proteins indicated that the viral fms proteins and the 140-kDa BeWo cell protein were highly related. This 140-kDa glycoprotein contained an associated tyrosine kinase activity in vitro and was labeled principally on serine after 32Pi metabolic labeling. These results suggest that the 140-kDa protein in BeWo cells is the protein product of the human c-fms proto-oncogene. This conclusion is supported by the finding that a similar protein is detectable only in other human cells that express c-fms mRNA. These other human cells include adherent monocytes and the cell line ML-1, which can be induced to differentiate along the monocyte-macrophage pathway. This is in agreement with current thought that the c-fms proto-oncogene product functions as the CSF-1 receptor specific to this pathway.

Antigens↗

A comparison of yeast ribosomal protein gene DNA sequences.

The DNA sequences of eight yeast ribosomal protein genes have been compared for the purpose of identifying homologous regions which may be involved in the coordinate regulation of ribosomal protein synthesis. A 12 bp homology was identified in the 5' DNA sequence preceding the structural gene for 6 out of 8 yeast ribosomal protein genes. In each case the homologous sequence was found at a position approximately 300 bp preceding the transcription start of the ribosomal protein gene. This homology was not identified in any non-ribosomal protein gene examined. Additional homologies between ribosomal protein genes were identified in the transcribed regions, including the untranslated 5' and 3' DNA regions flanking the coding regions.

Amino Acid Sequence↗

Transforming proteins of fujinami and PRCII avian sarcoma viruses have different subcellular locations.

The subcellular locations of transforming proteins encoded by the related avian sarcoma viruses, PRCII and Fujinami sarcoma virus (FSV), were compared by cell fractionation and by indirect immunofluorescence. Whereas both viruses encode gag-fps proteins associated with tyrosine-specific kinase activity, FSV is more highly tumorigenic than PRCII in vivo. Cell fractionation studies showed that the PRCII transforming protein, P105, became associated with the high-speed particulate fraction shortly after synthesis. However, PRCII P105 did not fractionate with the plasma membrane marker, but rather with high-density membranes. It is unique in this subcellular localization among viral tyrosine kinases. This membrane association was found to be relatively insensitive to salt concentration and did not require divalent cations. Immunofluorescent studies, using anti-fps serum, showed that the PRCII protein was present in discrete, large, cytoplasmic patches, as well as in a juxtanuclear location. In contrast, FSV-encoded P130 was found to fractionate with the plasma membrane marker when cells were analyzed in low salt in the presence of magnesium. However, at higher salt concentrations and in the absence of magnesium, the bulk of P130 was found to be soluble. Immunofluorescent staining of FSV P130 revealed a diffuse, cytoplasmic pattern that was distinct from that of the PRCII product. The observed difference in the subcellular localization of these transforming proteins may be the cause of the difference in tumorigenicity between the two viruses.

Animals↗

Isolation of yeast histone genes H2A and H2B.

Analysis of cloned sequences for yeast histone genes H2A and H2B reveals that there are only two copies of this pair of genes within the haploid yeast genome. Within each copy, the genes for H2A and H2B are separated by approximately 700 bp of spacer DNA. The two copies are separated from one another in the yeast genome by a minimum distance of 35-60 kb. Sequence homology between the two copies is restricted to the genes for H2A and H2B; the spacer DNA between the genes is nonhomologous. In both copies, the genes for H2A and H2B are divergently transcribed. In addition, both plasmids code for other nonhistone proteins. Sequences coding for histones H3 and H4 have not been detected in the immediate vicinity of the genes for H2A and H2B.

Base Sequence↗