Search PubMed⌕ Search

Biomedical subjects

D Hill

Publications and source records attributed to D Hill.

At least 271 records · Page 15Linked to original sources
PubMed1987

Uptake and quitting smoking trends in Australia 1974-1984.

Five cross-sectional surveys of random, cluster samples of the Australian population taken between 1974 and 1984 obtained information on the prevalence of smokers and ex-smokers. This information, however, does not provide the essential data for trend studies of smoking behavior: Estimates of the prevalence of smoking uptake and of smoking cessation are also required. The uptake rate for males ages 16-19 reached a peak in 1980. For females ages 16-19, the uptake rate reached a peak in 1983; in 1984 there was a significant drop in the percentage of female ever-smokers, which coincidentally corresponded to the introduction of large-scale, mass-media anti-smoking campaigns in Australia. A quit ratio has been defined in this study as the ratio of the proportion of ex-smokers to the proportion of those available to quit, that is, ever-smokers. This ratio enables community smoking cessation activity trends to be plotted. Quit ratios were similar for both sexes and increased at approximately 1% per year for almost all age groups studied. Overall, the percentage increase between 1974 and 1984 was greater for females than for males.

Adolescent↗
PubMed1987

Synthesis and characterization of all four isomers of the muscarinic agonist 2'-methylspiro[1-azabicyclo[2.2.2]octane-3,4'-[1,3]dioxolane].

The four separated isomers of the muscarinic agonist 1, previously known as AF30, have been synthesized by a route that has allowed the absolute stereochemistry of each isomer to be assigned. With the chirality of (-)-camphanic acid known, X-ray analysis of the more crystalline intermediate diastereomeric camphanate 5A allowed the absolute stereochemistry at the quinuclidine chiral center to be determined. Each diastereomer was separately transformed into the spirodioxolane with concomitant introduction of the second chiral center. Chromatographic separation followed by a second crystal structure determination revealed the absolute stereochemistry of all four isomers of 1. Detailed biological evaluation of each isomer indicated that while the 3(R),2'(S) isomer was the most active in binding studies, it was the 3(R),2'(R) isomer that displayed the largest functional selectivity between ganglion (M-1 site) and heart (M-2 site). With the same internal chiral standard, the absolute configuration of the more active enantiomer of 3 was shown to be S, confirming earlier literature reports.

Animals↗
PubMed1986

Electromagnetic field focusing (EFF) probe in aneurysm thrombosis. Preliminary report.

Due to its capability of producing a well localized intense heat field of predictable dimensions, the electromagnetic field focusing probe was evaluated experimentally as a surgical tool in aneurysm thrombosis. Aneurysm models were created by anastomosing a segment of vein to the abdominal aorta. Seventy-five such aneurysms were created in seventy-five animals. The aneurysms were then placed under the solenoidal radiofrequency coil and the tip of the field focusing probe was inserted into them. Intense heat was delivered with well defined, effective and quick thrombosis and shrinkage of the aneurysm. Nineteen of the aneurysms were followed for up to one week. Histological studies were conducted showing complete thrombosis of the aneurysm with good preservation of the aorta. With further refinement of this technique, it is hoped that stereotaxic aneurysm thrombosis might be possible.

Aneurysm↗
PubMed1986

Hyperinsulinism, glucose-dependent insulinotropic polypeptide, and the enteroinsular axis in morbidly obese patients before and after gastric bypass.

The role of glucose-dependent insulinotropic polypeptide (GIP) in the hyperinsulinism of morbid obesity and its correction after gastric bypass was studied in 12 morbidly obese (150 +/- 15 kg) patients. After oral glucose, significant increases in serum glucose, insulin, and GIP levels occurred both before and after gastric bypass. Compared with preoperative values, fasting concentrations and integrated incremental areas for glucose, insulin, and GIP were decreased after a 25% weight loss after gastric bypass. The hyperinsulinism of morbid obesity and its amelioration after gastric bypass may be caused by markedly elevated levels of GIP before surgery and its reduced release after bypass. Reduced release of GIP after gastric bypass may partly occur because of exclusion of ingested glucose from contact with the mucosa of the duodenum and proximal jejunum, sites with the highest concentration of GIP.

Adult↗
PubMed1985

Detection of papillomaviruses in cutaneous fibromas of white-tailed and mule deer.

Naturally occurring cutaneous fibromas affecting white-tailed deer (Odocoileus virginianus) and mule deer (O hemionus), and cutaneous fibropapillomas of domestic cattle were tested for papillomavirus using indirect immunofluorescence (IF), peroxidase-antiperoxidase (PAP), and negative-stain electron microscopic techniques. Papillomavirus was consistently detected using rabbit antiserum against papillomavirus group-specific antigen in all mule deer fibromas and bovine fibropapillomas; only 16 of 28 white-tailed deer fibromas tested by IF and 9 of 15 tested by PAP were detected. Normal skin from white-tailed deer or cattle was consistently negative for virus. Similar results were obtained by negative-stain electron microscopic examination of partially purified tumor homogenates. Using deer fibroma virus or bovine papillomavirus type 1-specific antisera, viruses were typed by IF, PAP, and immunoelectron microscopy.

Animals↗
PubMed1984

The mini-F primary origin. Sequence analysis and multiple activities.

The sequence of an 897 base-pair fragment (42.1 to 43.0 kilobase co-ordinates on the F genetic map) containing the primary origin (ori-1) of mini-F replication has been determined. It contains one significant open reading frame, which probably codes for part of the C protein thought to be necessary for ori-1 replication activity. Tests of the ability of the sequenced ori-1 region to direct replication of DNA polymerase I-dependent replicons revealed that ori-1 replication requires adjacent mini-F sequences, 43.0 to 43.9 kilobase co-ordinates on the F genetic map in cis as well as a trans-acting gene product, probably the E protein, from the essential replication region of mini-F. In addition, a sequence required for control of pif gene expression has been mapped to a 160 base-pair region immediately upstream from the C (pifC) gene, and the crossover site of a specific recA-independent recombination mechanism has been mapped to a 220 base-pair region on the side of the pif control sequence distal to the C gene.

Base Sequence↗