Biomedical subjects

K Stone

Publications and source records attributed to K Stone.

77 records · Page 5Linked to original sources

PubMedDate not supplied

Investigation of the adducts formed by reaction of malondialdehyde with adenosine.

Malondialdehyde (MDA) forms oligomeric adducts with DNA bases. It has been proposed that the 2:1 MDA-guanosine (M2G) and 3:1 MDA-adenosine (M3A) adducts result from sequential addition of MDA molecules to the nucleoside base. Reaction of 1:1 MDA-guanosine (M1G) and 1:1 MDA-adenosine (M1A) adducts with MDA does not produce the multimeric adducts. This suggests they arise by reaction of the nucleoside bases with oligomers of MDA. If so, the proposed structure for M3A is inconsistent with the addition of an MDA trimer to adenosine. Therefore, we investigated the structure of this molecule. Two-dimensional double quantum filtered COSY and hetero-COSY NMR experiments were performed, and a series of insensitive nuclei assignment by polarization transfer (INAPT) NMR spectra were also recorded. The results of these experiments revealed the presence of a propano group and two alpha,beta-unsaturated aldehydes. The UV spectrum of M3A displayed a maximum at 326 nm, similar to that of N6-[3-oxo-1(E)-propenyl]adenosine (M1A). The adducts were reduced with sodium borohydride for comparison of the UV and NMR spectra. On the basis of our results, a new structure for M3A is proposed which is tentatively named 6(5*,7*-diformyl-2*H-3*,6*-dihydro-2*,6*-methano-1*,3*-oxazocin -3*-yl)-9-beta-D-ribofuranosylpurine.

Adenosine↗

PubMedDate not supplied

Studies of the reaction of malondialdehyde with cytosine nucleosides.

The reaction of malondialdehyde (MDA) with cytosine nucleosides was investigated, and the structures of 1:1 and 3:1 MDA-cytosine adducts were identified. Ultraviolet and NMR spectroscopy indicates the structure of the 1:1 adduct is N4-(3-oxo-1-trans-propenyl)cytosine (M1C) and the structure of the 3:1 adduct is 6-(5*,7*-diformyl-2*H-3*,6*-dihydro-2*,6*-methano-1*,3*-oxazoci n-3*yl)-2- oxopyrimidine (M3C). Both adducts are analogous to previously identified MDA-adenine adducts. The time courses of adduct formation in the reaction of MDA with deoxycytidine at different pH's and using different sources of MDA were determined. M3C-deoxyribose is the major product at acidic pH whereas M1C-deoxyribose appears to be the sole adduct formed at neutral pH. These results suggest that adducts formed between nucleic acid bases and oligomers of MDA may not play a major role in MDA mutagenesis.

Cytosine↗

PubMedDate not supplied

Health education goes Hollywood: working with prime-time and daytime entertainment television for immunization promotion.

This article presents an entertainment education strategy used to influence Hollywood prime-time and daytime television programs to add storylines on the importance of immunizations to their shows. Rather than giving information about immunizations to show producers, directors, actors, and writers, we furnished "log lines" and true stories about immunizations that could be used to inspire scripts that included immunization themes. By working through personal contacts within the entertainment television industry's closed system of networks, we were able to gain entree and some airtime for our campaign agenda. Embedded messages aired on eight popular shows in the 1996-1997 broadcast season, with five scheduled to air in the 1997-1998 season. These efforts were evaluated qualitatively, focusing on issues of personal networks, content of aired messages, and comparative costs for paid airtime. The strategy developed can be adapted for a range of entertainment education interventions.

Adolescent↗

PubMedDate not supplied

Alagille syndrome: prenatal diagnosis and pregnancy outcome.

The Alagille syndrome (AGS) is a multisystem autosomal dominant condition. In this case report, we describe a pregnant woman with this unusual disorder, in whom serial fetal sonography revealed severe pulmonary stenosis and progressively severe intrauterine growth retardation, suggesting that the fetus also had AGS, a diagnosis which was confirmed postnatally. In this report, the potential complications for pregnancy, labor and delivery when both mother and fetus are affected with AGS are described.

Adult↗

PubMedDate not supplied

An holistic approach to turning patients.

Turning patients who are immobile is usually undertaken expressly to prevent pressure sores. Here the authors highlight some of the other factors that need to be taken into account when nursing dependent and/or immobile patients.

Activities of Daily Living↗