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Biomedical subjects

L Gold

Publications and source records attributed to L Gold.

At least 145 records · Page 8Linked to original sources
PubMed1984

Delila system tools.

We introduce three new computer programs and associated tools of the Delila nucleic-acid sequence analysis system. The first program, Module, allows rapid transportation of new sequence analysis tools between scientists using different computers. The second program, DBpull, allows efficient access to the large nucleic-acid sequence databases being collected in the United States and Europe. The third program, Encode, provides a flexible way to process sequence data for analysis by other programs.

Base Sequence↗
PubMed1984

Elevated L-xylulose concentrations in serum: a difference between type I and type II diabetes.

L-Xylulose, which can be derived from glucose directly or from mucopolysaccharide degradation, was measured in serum samples from 61 diabetics and 42 controls. All serum samples from the controls were negative for L-xylulose. Fifteen of 30 adult-onset diabetics, in contrast to only four of 31 juvenile-onset diabetics, had detectable L-xylulose levels. This difference between adult-onset and juvenile-onset diabetics was significant at the 0.001 level. Detectability of L-xylulose in serum did not appear to be influenced by the fasting mean or peak serum concentration of glucose. Mean serum concentrations of growth hormone did not correlate with L-xylulose levels. The reason for the variation of L-xylulose between type-I and type-II diabetic subjects could not be identified. We would postulate a variation in the degradation of glycosaminoglycan. These results support the view that type-I and type-II diabetes are different diseases.

Blood Glucose↗
PubMed1983

Overproduction of bacteriophage Q beta maturation (A2) protein leads to cell lysis.

Double-stranded cDNA from the maturation (or A2) protein gene of the RNA bacteriophage Q beta has been cloned such that its expression is regulated by the E. coli lac promoter/operator. Induction of the A2 clone is lethal to the host. The basis of this lethality is cell lysis, which is correlated with synthesis of the A2 protein. No other major proteins appear to be made from the A2 gene when inducer is added. Plasmid-derived A2 protein specifically complements infecting Q beta A2 amber mutants. Lysis activity is abolished in clones that synthesize truncated or internally deleted A2 polypeptides ranging from 10% to 95% of the length of wild-type protein. We conclude that host lysis is promoted by the maturation protein itself, rather than by a separate lysis protein. The A2 protein probably allows for the release of progeny Q beta phage particles following normal infection.

Cell Survival↗
PubMed1983

Bacterial and phage mutations that reveal helix-unwinding activities required for bacteriophage T4 DNA replication.

An Escherichia coli strain with a mutation in the optA gene restricts the growth of bacteriophage T4 strains partially defective in gene 43 (DNA polymerase) or missing gene dda (DNA-dependent ATPase). The mutations in the dda gene inactivate a DNA-dependent ATPase that has been shown to have DNA helicase activity in vitro. We show that the restriction of phage growth after infection of the optA bacterium is the result of a block in DNA replication. We infer that the block arises from a defect in DNA unwinding.

DNA Helicases↗
PubMed1982

Use of the 'Perceptron' algorithm to distinguish translational initiation sites in E. coli.

We have used a "Perceptron" algorithm to find a weighting function which distinguishes E. coli translational initiation sites from all other sites in a library of over 78,000 nucleotides of mRNA sequence. The "Perceptron" examined sequences as linear representations. The "Perceptron" is more successful at finding gene beginnings than our previous searches using "rules" (see previous paper). We note that the weighting function can find translational initiation sites within sequences that were not included in the training set.

Base Sequence↗
PubMed1982

On the role of the single-stranded DNA binding protein of bacteriophage T4 in DNA metabolism. I. Isolation and genetic characterization of new mutations in gene 32 of bacteriophage T4.

The product of gene 32 of bacteriophage T4 is a single-stranded DNA binding protein involved in T4 DNA replication, recombination and repair. Functionally differentiated regions of the gene 32 protein have been described by protein chemistry. As a preliminary step in a genetic dissection of these functional domains, we have isolated a large number of missense mutants of gene 32. Mutant isolation was facilitated by directed mutagenesis and a mutant bacterial host which is unusually restrictive for missense mutations in gene 32. We have isolated over 100 mutants and identified 22 mutational sites. A physical map of these sites has been constructed and has shown that mutations are clustered within gene 32. The possible functional significance of this clustering is considered.

Base Sequence↗
PubMed1982

Central giant cell granuloma of the mandible. A case report.

Although a benign lesion, the central giant cell granuloma can be locally aggressive and quite destructive. The case reported here involved a giant cell lesion occurring in the mandibular symphysis of an 11-year-old girl. The treatment required four hospital admissions over a period of 4 years. The surgical intervention was complicated by a localized infection requiring closed reduction and bone grafting. The patient was followed over a period of 8 years, during which there was no recurrence of tumor or infection subsequent to the last surgical procedure.

Child↗
PubMed1982

Determination of the amount of homology required for recombination in bacteriophage T4.

Homology is an important feature of recombination. We have used the rll cistrons of bacteriophage T4 to determine the extent of homology required for recombination. We varied the amount of homologous DNA available for recombination in both marker rescue experiments and deletion-by-deletion crosses. Our results suggest that the primary pathway for recombination in T4 requires 50 bp of homology. Our finding that recombination is detectable when fewer than 50 bp of homology are available suggests that there is a second, less efficient pathway of recombination in T4. This pathway may be used during the formation of deletions.

Base Sequence↗
PubMed1981

Translational regulation: identification of the site on bacteriophage T4 rIIB mRNA recognized by the regA gene function.

The bacteriophage T4 gene regA encodes a protein that diminishes the expression of many unlinked early T4 genes. Previous work demonstrated that regA-mediated repression occurs after transcription. We report here on the identification of the target site on one regA-sensitive mRNA, the message encoding the phage T4 rIIB protein. The target for regA-mediated action overlaps the translational initiation domain of the rIIB messenger. The regA protein may be a repressor that operates translationally on a significant and interesting set of early phage T4 mRNAs.

Base Sequence↗