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Biomedical subjects

C Gray

Publications and source records attributed to C Gray.

At least 127 records · Page 7Linked to original sources
PubMed1997

Relationship between age of commercial broiler chickens and response to photostimulation.

A study was conducted to determine the relationship between age of commercial broiler chickens and response to photostimulation. The chickens were brooded collectively for 1 wk and then separated into five light treatment groups with each group replicated three times using a completely randomized block design. After Week 1, the five light treatments applied were: 6, 5, 4, 3, and 2 wk of continuous supplementary lighting, respectively. Chickens were fed a corn-soybean meal basal diet containing 22% CP and 3,300 kcal ME/ kg of feed from day old to 7 wk. At 7 wk of age, chickens in Group 5 treated with supplementary light during the last 2 wk of growth had the highest mean BW when the data on sexes were combined. When the data were separated by sex and analyzed, only male chickens showed a significant response to photostimulation and this was observed at 4 wk of age. Chickens in Group 5 had the best feed conversion with less mortality and no leg disorders. There were no significant differences among the relative organ weights among the treatment groups except for the pancreas. The pancreas taken from Group 5 had the smallest weight relative to BW. There were no significant differences in breast, thigh, drumstick, and wing weights when expressed as relative weight. However, there were significant differences when expressed as absolute weight. The breasts taken from birds in Group 5 were significantly heavier than the control breasts.

Animal Feed↗
PubMed1996

MD crosses great divide when moving between practices in Canada, US.

A Canadian surgeon who also practises in the US says the cross-border experience has provided him with an up-close look at the widening gulf separating medical care in the two countries. Dr. Robert Harris says Canadian physicians are no longer able to practise to the standards set south of the border.

Attitude of Health Personnel↗
PubMed1996

NHS reforms reduce length of waiting lists but create widespread unease.

Reforms involving the National Health Service (NHS) have greatly reduced the length of waiting lists in the United Kingdom. The key to the reductions was additional funding from the government, the chief executive of the NHS said during a recent visit to Ottawa. Decreasing the size of the waiting lists created intense stress for NHS personnel, who had to work longer hours, and it also lowered demand for private-sector care.

Canada↗
PubMed1996

1996 up & comers. Strategies for success.

They're bright, focused and aggressive. They're on a mission to improve the quality of America's healthcare provider organizations. They're MODERN HEALTHCARE's 1996 Up & Comers, a dozen healthcare professionals 40 and younger who are in the vanguard of the next generation.

Administrative Personnel↗
PubMed1996

Community education for cardiovascular disease prevention. Morbidity and mortality results from the Minnesota Heart Health Program.

The Minnesota Heart Health Program was a community trial of cardiovascular disease prevention methods that was conducted from 1980 to 1990 in three Upper Midwestern communities with three matched comparison communities. A 5- to 6-year intervention program used community-wide and individual health education in an attempt to decrease population risk. A major hypothesis was that the incidence of validated fatal and nonfatal coronary heart disease and stroke in 30- to 74-year-old men and women would decline differentially in the education communities after the health promotion program was introduced. This hypothesis was investigated using mixed-model regression. The intervention effect was modeled as a series of annual departures from a linear secular trend after a 2-year lag from the start of the intervention program. In the education communities, 2,394 cases of coronary heart disease and 818 cases of stroke occurred, with 2,526 and 739 cases, respectively, being seen in the comparison communities. The overall decline in coronary heart disease incidence was 1.8 percent per year in men (p = 0.03) and 3.6 percent per year in women (p = 0.007). For stroke, there were no significant secular trends. The authors recently published findings showing minimal effects of sustained intervention on risk factor levels. In the current report, there was no evidence of a significant intervention effect on morbidity or mortality, either for coronary heart disease or for stroke.

Adult↗
PubMed1996

Characterization of a multicomponent receptor for GDNF.

Glial-cell-line-derived neurotrophic factor (GDNF) is a potent survival factor for central and peripheral neurons, and is essential for the development of kidneys and the enteric nervous system. Despite the potential clinical and physiological importance of GDNF, its mechanism of action is unknown. Here we show that physiological responses to GDNF require the presence of a novel glycosyl-phosphatidylinositol (GPI)-linked protein (designated GDNFR-alpha) that is expressed on GDNF-responsive cells and binds GDNF with a high affinity. We further demonstrate that GDNF promotes the formation of a physical complex between GDNFR-alpha and the orphan tyrosin kinase receptor Ret, thereby inducing its tyrosine phosphorylation. These findings support the hypothesis that GDNF uses a multi-subunit receptor system in which GDNFR-alpha and Ret function as the ligand-binding and signalling components, respectively.

Amino Acid Sequence↗
PubMed1996

Visions of our health care future: is a parallel private system the answer?

In this time of spending restraint, arguments for and against a two-tier medical system are common. Proponents say governments can no longer afford to supply all the health care we want and Canadians should have the right to purchase it, just as they purchases other services and commodities. Opponents fear that administrative costs will rise greatly if this happens, the best physicians will leave the public system and public support for medicare will erode. For this article, Charlotte Gray sought opinions on whether a parallel private system is a good option for Canadians to consider.

Canada↗
PubMed1996

Visions of our Medicare future: status quo has become a dirty word in Canadian health care.

This is the second article in a three-part series on the future of Canada's health care system. The articles are presented as a follow-up to the impassioned debate on the topic during the CMA's 1995 annual meeting in Winnipeg. The first article, which appeared in the Feb. 1 issue, dealt with the development of a parallel private health care system in the United Kingdom. This article deals with the consequences of maintaining the health care status quo in Canada. The final one, to appear Apr. l, will debate whether a parallel private system is a worthwhile option for Canada to consider. Last August, General Council decided unanimously that the CMA should spark a national debate on the advisability of introducing private insurance for all medical services.

Canada↗
PubMed1996

Topographically induced bone formation in vitro: implications for bone implants and bone grafts.

We have investigated the influence of substrate topography on the timing and location of bone formation by rat osteoblasts. 250 mu m thick slabs of dental tissues were used intact or had a rectangular grid of grooves (350 mu m wide and of variable depth) cut with a diamond wheel. They were then seeded with rat calvarial osteoblasts and cultured in MEM with 10% FCS at 37 degrees C in 5% CO(2). Ascorbic acid 50 mu g/mL and beta-glycero-phosphate 2 mmol/L were added at confluence. Cultures were observed daily from 2 to 4 weeks, until fixation (and storage) in 70% ethanol. Most were stained with alizarin red S to visualize the newly formed bone. The presence of gap junctions in the bone nodules was determined using connexin-43 immunolabeling and confocal microscopy. Two specimens were embedded in polymethylmethacrylate (PMMA): micromilled blockfaces were coated with carbon and examined by digital backscattered electron (BSE) microscopy. Bone formation began in the second week, preferentially wherever cellular condensation was favored: these locations were (a) within the grooves; (b) at the junction between the slab and the bottom of the culture dish; (c) at the periphery of the dish; and (d) in cracks where dissimilar tissues had separated. In the grooves, a grid of aligned bone developed, the deeper trenches showing bone formation earlier than shallower ones, with bone formation tapering off as a groove became shallower. BSE images showed that the bone formed was well mineralized and contained a high volume proportion of osteocytes. Mean and median values for the mean BSE coefficients were: in vitro bone in grooves 0.138528, 0.141484; in vivo aged bone (2 year old rat mandible) 0.143431, 0.144206; and in vivo young bone (neonate rat cranium) 0.129011, 0.132696. Connexin-43 gap junctions were immunolocalized on osteocytes fully enclosed within bone and on osteoblasts overlying it. We conclude first that local topography is an important factor in the location and timing of bone formation in vitro, and that it is likely to be equally important in vivo in normal bone turnover, fracture repair and the incorporation of bone grafts. Second, the mineral density of the bone formed in vitro is consistent with its being true bone.

Animals↗
PubMed1996

Effect of the N-terminal glycine on the secondary structure, orientation, and interaction of the influenza hemagglutinin fusion peptide with lipid bilayers.

The amino-terminal segment of the membrane-anchored subunit of influenza hemagglutinin (HA) plays a crucial role in membrane fusion and, hence, has been termed the fusion peptide. We have studied the secondary structure, orientation, and effects on the bilayer structure of synthetic peptides corresponding to the wild-type and several fusogenic and nonfusogenic mutants with altered N-termini of the influenza HA fusion peptide by fluorescence, circular dichroism, and Fourier transform infrared spectroscopy. All peptides contained segments of alpha-helical and beta-strand conformation. In the wild-type fusion peptide, 40% of all residues were in alpha-secondary and 30% in beta-secondary structures. By comparison, the nonfusogenic peptides exhibited larger beta/alpha secondary structure ratios. The order parameters of the helices and the amide carbonyl groups of the beta-strands of the wild-type fusion peptide were measured separately, based on the infrared dichroism of the respective absorption bands. Order parameters in the range 0.1-0.7 were found for both segments of the wild-type peptide, which indicates that they are most likely aligned at oblique angles to the membrane normal. The nonfusogenic but not the fusogenic peptides induced splitting of the infrared absorption band at 1735 cm(-1), which is assigned to stretching vibrations of the lipid ester carbonyl bond. This splitting, which reports on an alteration of the hydrogen bonds formed between the lipid ester carbonyls and water and/or hydrogen-donating groups of the fusion peptides, correlated with the beta/alpha ratio of the peptides, suggesting that unpaired beta-strands may replace water molecules and hydrogen-bond to the lipid ester carbonyl groups. The profound structural changes induced by single amino acid replacements at the extreme N-terminus of the fusion peptide further suggest that tertiary or quaternary structural interactions may be important when fusion peptides bind to lipid bilayers.

Amino Acid Sequence↗
PubMed1996

Management of Caesarean delivery in the presence of a large pelvic vascular malformation.

Caesarean section is associated with significant cardiovascular disturbances. We present a patient known to have a large pelvic arteriovenous malformation who underwent elective Caesarean section. To assist in the monitoring and management of the anticipated haemodynamic changes a flow directed pulmonary artery catheter with the capacity to allow continuous cardiac output measurement was used.

Adult↗
PubMed1996

Sensitivity of Escherichia coli O157:H7 strain 932 to selected anticoccidial drugs in broiler chicks.

The ability of selected anticoccidial drugs to inhibit the colonization of day-old male broiler chicks (Cornish Rocks) by Escherichia coli O157:H7, strain 932 was examined. Chicks were challenged with 1.8 x 10(9) E. coli O157:H7 on Day 1, and fed diets supplemented with three selected anticoccidial drugs; monensin, nicarbazin, or robenidine. The cecal and colon fecal contents of the chicks were removed on Day 7, 14, and 21 postinoculation and examined for the concentration of E. coli O157: H7 per gram of contents. Monensin effectively reduced cecal and colon colonization of the chicks by E. coli O157:H7. By Day 7, there were significant reductions in the bacterial population of the cecal contents of chicks receiving the monensin-medicated feed, and by Day 21 no E. coli O157:H7 was recovered from the cecal and colon contents. The bacterial counts in the colon contents of the nicarbazin- and robenidine-medicated and unmedicated chicks were significantly higher than the monensin-treated chicks. Bacterial populations in the colon contents were high only when there were high bacterial concentrations in the cecal contents.

Animals↗