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Biomedical subjects

W A Jones

Publications and source records attributed to W A Jones.

At least 19 recordsLinked to original sources

Phylogenetic relationships among transposon-like elements in human and primate DNA.

A THE-1 sequence in intron 7 of the human dystrophin gene has been found to represent a new subfamily of THE-1 elements. The sequence is closely related to the MstII family of repetitive sequences and is more like single-copy sequences found in the galago genome than any other THE-1 sequence previously reported. This new THE-1 sequence has been compared with two other complete THE-1 sequences and three related long-terminal repeat elements that we have previously found in intron 7 of the dystrophin gene, and with members of the same family from elsewhere in the primate genome. Parsimony and deletion analysis show that the cluster of THE-1 sequences in intron 7 of the dystrophin gene has arisen from at least three individual insertion events, rather than from the insertion and duplication of a single progenitor sequence.

Animals

Sequence of a transposon identified as Tn1000 (gamma delta).

We report the complete sequence of a transposon found in a cosmid clone of a human DNA sequence. The transposon is identified as the Escherichia coli transposon Tn1000 (also known as gamma delta) on the basis of the identity of the restriction map of the new sequence with that previously recorded for Tn1000 and homology between parts of the new sequence and that of published fragments of Tn1000 sequence. The transposon, which comprises 5,981 nucleotides including two 35 bp inverted terminal repeat sequences (ITRs), contains three open reading frames. The sequence of the resolvase coding region (tnpR) is identical to that published by others. A second reading frame can be identified as the tnpA gene, coding for the transposase, on the grounds of its strong homology with the corresponding gene from transposon Tn3. The third reading frame has the potential to code for a protein of unknown function containing 698 amino acids.

Amino Acid Sequence

Simple excision of the trapezium for osteoarthritis of the carpometacarpal joint of the thumb.

We have reviewed the results in 34 patients (39 operations) following simple excision of the trapezium for osteoarthritis of the basal joint of the thumb. The average age at operation was 57 years and the average follow-up was 6 years. All the patients were graded clinically and radiologically and were asked their opinion of the procedure. There was dramatic relief of pain following this procedure. Stability of the thumb was not compromised. When compared to the unoperated side, thumb length, thumb abduction and first web span were similar. There was a reduction in pinch strength (operated 8.1 k.p.a., non-operated 9.6 k.p.a.) and grip strength (operated 15.5 k.p.a., non-operated 19.5 k.p.a.) and an increase in MIP extension (operated 5.4 degrees, non-operated 2.9 degrees) following this procedure but the differences were not statistically significant. 11 patients (32%) had scar hyperaesthesia on testing but this was a clinical problem in two patients only (5%). Simple excision of the trapezium is a satisfactory procedure for the majority of patients with this disorder, but has a long post-operative rehabilitation period.

Aged

Sequencing and expression of a cellodextrinase (ced1) gene from Butyrivibrio fibrisolvens H17c cloned in Escherichia coli.

The nucleotide sequence of a 2.314 kb DNA segment containing a gene (ced1) expressing cellodextrinase activity from Butyrivibrio fibrisolvens H17c was determined. The B. fibrisolvens H17c gene was expressed from a weak internal promoter in Escherichia coli and a putative consensus promoter sequence was identified upstream of a ribosome binding site and a GTG start codon. The complete amino acid sequence (547 residues) was deduced and homology was demonstrated with the Clostridium thermocellum endoglucanase D (EGD), Pseudomonas fluorescens var. cellulosa endoglucanase (EG), and a cellulase from the avocado fruit (Persea americana). The ced1 gene product Ced1 showed cellodextrinase activity and rapidly hydrolysed short-chain cellodextrins to yield either cellobiose or cellobiose and glucose as end products. The Ced1 enzyme released cellobiose from p-nitrophenyl-beta-D-cellobioside and the enzyme was not inhibited by methylcellulose, an inhibitor of endoglucanase activity. Although the major activity of the Ced1 enzyme was that of a cellodextrinase it also showed limited activity against endoglucanase specific substrates [carboxymethylcellulose (CMC), lichenan, laminarin and xylan]. Analysis by SDS-polyacrylamide gel electrophoresis with incorporated CMC showed a major activity band with an apparent Mr of approximately 61,000. The calculated Mr of the ced1 gene product was 61,023.

Amino Acid Sequence

Early open reduction for congenital dislocation of the hip.

We have reviewed 82 children with congenital dislocation of the hip, after treatment by anterior open reduction followed by derotation femoral osteotomy. The clinical and radiological results were significantly better in the group that had open reduction before the appearance of the capital femoral epiphysis; this group also had a lower incidence of avascular necrosis. We conclude that, when it is clearly indicated, the earlier an open reduction is carried out the better the results.

Child, Preschool

Molecular analysis and nucleotide sequence of the adh1 gene encoding an NADPH-dependent butanol dehydrogenase in the Gram-positive anaerobe Clostridium acetobutylicum.

The nucleotide sequence of a 2081-bp fragment of Clostridium acetobutylicum DNA containing the adh1 gene was determined. The butanol dehydrogenase gene is referred to as the adh1 gene since it was shown to have activity using butanol and ethanol as substrates. The adh1 gene consisted of 1164 bp and encoded an alcohol dehydrogenase (ADH) enzyme of 388 aa residues with an Mr of 43,274. The adh1 gene was separated from an upstream open reading frame by an intergenic region of 354 bp. No promoter consensus sequences were identified in the intergenic upstream region and the adh1 gene did not appear to be expressed off its own promoter in Escherichia coli. Three separate types of ADH have been recognized. The ADH1 from C. acetobutylicum exhibited 39% homology with the Fe-containing ADH2 from Zymomonas mobilis and 37% homology with the ADH4 from Saccharomyces cerevisiae, but showed little or no homology with the other characterised types of ADH.

Alcohol Oxidoreductases

Cloning and sequencing of an endoglucanase (end1) gene from Butyrivibrio fibrisolvens H17c.

The nucleotide sequence of a 2.8 kb DNA segment containing an endoglucanase gene (end1) from Butyrivibrio fibrisolvens H17c was determined. The B. fibrisolvens H17c gene was expressed from its own regulatory region in Escherichia coli and three putative consensus promoter sequences were identified upstream of a ribosome binding site and an ATG start codon. The complete amino acid sequence (547 residues) was deduced and homology with the Clostridium thermocellum celE gene product (EGE) was demonstrated. The endoglucanase contained a typical amino-terminal signal sequence and five repeated sequences (PDPTPVD) between amino acids 412-447. The endoglucanase showed relatively high endoglucanase activity against endoglucanase-specific substrates with beta 1-4 linkages but low activity against xylan and an exoglucanase-specific substrate, p-nitrophenyl-beta-D-cellobioside.

Amino Acid Sequence

Nucleotide sequence of the Vibrio alginolyticus glnA region.

The nucleotide sequence of a 4 kb fragment containing the Vibrio alginolyticus glnA, ntrB and ntrC genes was determined. The upstream region of the glnA gene contained tandem promoters. The upstream promoter resembled the consensus sequence for Escherichia coli sigma 70 promoters whereas the presumptive downstream promoter showed homology with nitrogen regulated promoters. Four putative NRI binding sites were located between the tandem promoters. The ntrB gene was preceded by a single presumptive NRI binding site. The ntrC gene was located 45 base pairs downstream from the ntrB gene. The V. alginolyticus ntrB and ntrC genes were able to complement ntrB, ntrC deletions in E. coli.

Amino Acid Sequence

Structure of an endo-beta-1,4-glucanase gene from Clostridium acetobutylicum P262 showing homology with endoglucanase genes from Bacillus spp.

The nucleotide sequence of an endo-beta-1,4-glucanase gene of Clostridium acetobutylicum contained two putative extended promoter consensus sequences, a Shine-Dalgarno sequence and a TTG initiation codon. The nucleotide sequence of the gene coding for the C-terminal region of this enzyme was not required for activity. Extensive homology in the nucleotide and amino acid sequences of the endoglucanase genes from C. acetobutylicum and Bacillus spp. was demonstrated.

Amino Acid Sequence

Molecular analysis and regulation of the glnA gene of the gram-positive anaerobe Clostridium acetobutylicum.

The nucleotide sequence of a 2.0-kilobase DNA segment containing the Clostridium acetobutylicum glnA gene was determined. The upstream region of the glnA gene contained two putative extended promoter consensus sequences (p1 and p2), characteristic of gram-positive bacteria. A third putative extended gram-positive promoter consensus sequence (p3), oriented towards the glnA gene, was detected downstream of the structural gene. The sequences containing the proposed promoter regions p1 and p2 or p3 were shown to have promoter activity by subcloning into promoter probe vectors. The complete amino acid sequence (444 residues) of the C. acetobutylicum glutamine synthetase (GS) was deduced, and comparisons were made with the reported amino acid sequences of GS from other organisms. To determine whether the putative promoter p3 and a downstream region with an extensive stretch of inverted repeat sequences were involved in regulation of C. acetobutylicum glnA gene expression by nitrogen in Escherichia coli, deletion plasmids were constructed lacking p3 and various downstream sequences. Deletion of the putative promoter p3 and downstream inverted repeat sequences affected the regulation of GS and reduced the levels of GS approximately fivefold under nitrogen-limiting conditions but did not affect the repression of GS levels in cells grown under nitrogen-excess conditions.

Amino Acid Sequence

Beware the sprained wrist. The incidence and diagnosis of scapholunate instability.

A consecutive series of 100 cases of wrist injury, other than those referred with a radial fracture, have been reviewed to determine the incidence of acute scapholunate instability; a "clenched fist" radiograph was used in addition to the routine scaphoid views. Of 19 patients with an increase in the scapholunate gap, five were eventually considered to have significant scapholunate instability, two in association with Colles' fractures. Injuries producing significant ligamentous damage and carpal instability may be as common as scaphoid fractures. They require special consideration in diagnosis and management.

Adult

Nucleotide sequence of the glutamine synthetase gene and its controlling region from the acidophilic autotroph Thiobacillus ferrooxidans.

A 2089-bp chromosomal DNA segment containing the Thiobacillus ferrooxidans glnA gene has been sequenced. Putative glnAp1-type promoter sequences, a consensus ntrC-gene-product-binding site and a catabolite-activating protein consensus recognition sequence were detected upstream of the structural gene. The glnA gene was followed by a sequence resembling a Rho-independent termination sequence. The complete amino acid sequence (468 residues) of the glutamine synthetase (GS) has been deduced, and comparisons are made with reported amino acid sequences of GS from other organisms.

Amino Acid Sequence

Nucleotide sequence of the gene encoding the nitrogenase iron protein of Thiobacillus ferrooxidans.

The DNA sequence was determined for the cloned Thiobacillus ferrooxidans nifH and part of the nifD genes. A putative T. ferrooxidans nifH promoter was identified whose sequences showed perfect consensus with those of the Klebsiella pneumoniae nif promoter. Two putative consensus upstream activator sequences were also identified. The amino acid sequence was deduced from the DNA sequence. In a comparison of nifH DNA sequences from T. ferrooxidans and eight other nitrogen-fixing microbes, a Rhizobium sp. isolated from Parasponia andersonii showed the greatest homology (74%) and Clostridium pasteurianum (nifH 1) showed the least homology (54%). In a comparison of the amino acid sequences of the Fe proteins, the Rhizobium sp. and Rhizobium japonicum showed the greatest homology (both 86%) and C. pasteurianum (nifH 1 gene product) demonstrated the least homology (56%) to the T. ferrooxidans Fe protein.

Amino Acid Sequence