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T Vincent

Publications and source records attributed to T Vincent.

10 recordsLinked to original sources

Molecular cloning of the UMP synthase gene rudimentary-like from Drosophila melanogaster.

The rudimentary-like locus encodes UMP synthase, a bienzyme protein containing the last two enzyme activities of de novo pyrimidine biosynthesis: orotate phosphoribosyltransferase and orotidylate decarboxylase. This locus lies within chromosome region 93B. New mutations have been used to refine the 93B cytogenetic map and a chromosome walk has been executed to clone DNA from this region. DNA encoding UMP synthase was identified using mixed oligonucleotides which were based on sequences derived from conserved peptide tracts of the protein in other species. cDNA clones of the embryonic UMP synthase mRNA have been isolated and used to define the extent of genomic DNA sequences which encode the transcript. The embryonic RNA is approximately 1.75 kb in length.

Amino Acid Sequence

Geographical variation in mortality from leukaemia and other cancers in England and Wales in relation to proximity to nuclear installations, 1969-78.

The distribution of mortality from 11 causes of death (lymphoid leukaemia, other leukaemia, leukaemia of all types, Hodgkin's disease, other lymphomas, all lymphomas, multiple myeloma, lung cancer, other malignancies, all malignancies and all other causes) has been examined in three age groups throughout England and Wales over the period 1969-78. The reorganisation of local authority administration in 1974 meant that the smallest areas that could be examined were 400 county districts or (in some cases) approximate county districts formed by aggregating pre-1974 local authority areas. The variation in the numbers of deaths observed about the numbers expected was assessed using log-linear models to estimate the effect on the relative risk in each district associated with social class, rural status, population size, health authority region and proximity to one of 15 nuclear installations. Trends in risk with increasing proximity to an installation (as judged by the proportion of the population resident within 10 miles) were examined after adjustment for the other four variables. The results showed that in districts near to an installation there were significant excess mortalities in persons under 25 years of age from leukaemia (RR = 1.15, P = 0.01) and especially from lymphoid leukaemia (RR 1.21, P = 0.01) and from Hodgkin's disease (RR 1.24, P = 0.05) and a significant deficiency of mortality from lymphoid leukaemia in persons aged 25-64 years. No significant trends were observed with an increasing proportion of the population near to the installations and the greatest excess mortality from lymphoid leukaemia in young persons was observed in the districts with the intermediate proportion of the population (10.0-65.9%) near an installation.

Adolescent

Effect of experimental azotemia on intestinal transport of butyric acid.

Earlier studies have revealed an impairment of jejunal absorption of long chain fatty acids in experimental uremia. We investigated the intestinal absorption of butyric acid which is a short chain fatty acid in experimental renal failure (RF). Sprague-Dawley rats were randomized into the RF group which had subtotal nephrectomy, a sham-operated control group, and a pair-fed group. In vivo recirculating perfusion (n = 5) and in vitro everted sac incubation (n = 8) were employed. The in vitro experiments were repeated substituting the serosal buffer by either predialysis or postdialysis sera from uremic individuals, or normal serum (n = 10). The rate of in vivo butyric acid absorption was significantly lower while the in vitro absorption was significantly higher in the RF group than those observed in the sham-operated and pair-fed groups which showed comparable values. The normality of butyric acid absorption in the pair-fed animals despite comparable weight loss with the RF group tends to exclude anorexia and weight loss as a cause of altered butyric acid transport in RF animals. The disparity between the in vivo and in vitro data is suggestive of an inhibitory influence of uremic environment which is present in vivo and absent in vitro. This viewpoint was corroborated by the observed fall in butyric acid absorption by sacs containing predialysis uremic serum as compared with those containing normal or postdialysis sera. The latter further suggests that the inhibitory factor(s) is dialyzable.

Animals

Bilateral carotid siphon involvement in giant cell arteritis.

A 60-year-old woman with inadequately treated giant cell arteritis developed an acute unilateral ischemic optic neuropathy associated with bilateral carotid artery and orbital bruits. Angiography demonstrated vascular changes compatible with arteritis localized to the cavernous and petrous segments of both internal carotid arteries. After treatment with high dose steroids, the bruits disappeared.

Blindness