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Biomedical subjects

C J Donnelly

Publications and source records attributed to C J Donnelly.

7 recordsLinked to original sources
PubMed2001

The NADH oxidase from Pyrococcus furiosus. Implications for the protection of anaerobic hyperthermophiles against oxidative stress.

A wealth of H(2)O-producing NADH oxidase (NOX) homologues have been discovered in the genomes of the hyperthermophilic Archaea, including two homologues in the genome of Pyrococcus furiosus which have been designated as NOX1 and NOX2. In order to investigate the function of NOX1, the structural gene encoding NOX1 was cloned from the genome of P. furiosus and expressed in Escherichia coli, and the resulting recombinant enzyme (rNOX1) was purified to homogeneity. The enzyme is a thermostable flavoprotein that can be reconstituted only with FAD. rNOX1 catalyzes the oxidation of NADH, producing both H(2)O(2) and H(2)O as reduction products of O(2) (O(2) + 1-2NADH + 1-2H(+) --> 1-2NAD(+) + H(2)O(2) or 2H(2)O). To our knowledge, this is the first NADH oxidase found to produce both H(2)O(2) and H(2)O. The enzyme exhibits a low K(m) for NADH (< 4 microm), and shows little or no reaction with NADPH. Transcriptional analyses demonstrated that NOX1 is constitutively expressed regardless of the carbon source and a single promoter was identified 25 bp upstream of the nox1 gene by primer extension. Although P. furiosus is a strict anaerobe, it may tolerate oxygen to some extent and we anticipate NOX1 to be involved in the response to oxygen at high temperatures.

Amino Acid Sequence↗
PubMed1978

The oral health of adults in the Baltimore SMSA study area.

This study, carried out in the region including Baltimore, Maryland, USA followed the pattern previously reported in the studies in Australia, New Zealand, Norway, Germany and Japan (Int. dent. J. 1976, 26, 317). In this area dental care is provided predominantly by payment of fees for service in private practice. Details are given of the oral health status in terms of caries, periodontal disease and loss of teeth for a group of 1142 adults aged between 35 and 45. Using the WHO stepwise regression analysis the significance of the previously reported predictors for each of the variables examined was determined. Finally a comparison is made between the present findings and those from an earlier National Health Survey carried out between 1960 and 1962. This suggests that while the caries situation may have improved over the past fifteen years, periodontal disease and loss of teeth have increased.

Adult↗
PubMed1977

Plaque, caries, periodontal diseases, and acculturation among Yanomamö Indians, Venezuela.

The number of DM and d teeth and surfaces was recorded for 220 Yanomamö Indians from three groups of villages with different degrees of contact with Western culture. Specimens of plaque were taken from the teeth, transported in a holding solution, cultured, and examined for specific oral streptococci. In addition, the periodontal health and oral hygiene of one group of villagers were assessed using the Russell PI and the Greene & Vermillions OHIS. Caries experience among the Yanomamö was shown to be positively associated with exposure to Western culture. S. mutans was recovered with about the same frequency from specimens taken from the teeth of Indians living at all three village locations. However, the presence of S. mutans alone did not account for the disparity in dental caries scores. The examinees had abundant and persistent accumulations of soft deposits on their teeth accompanied by markedly inflamed gingival tissues. However, periodontal pockets and loss of appreciable amounts of bone did not appear as early in life nor were they as severe as reported for some other populations which practice little oral hygiene. Those disparities in the distribution of plaque-induced oral diseases between Western populations and the Yanomamö warrant further study.

Acculturation↗