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Biomedical subjects

R Blair

Publications and source records attributed to R Blair.

At least 127 records · Page 7Linked to original sources

Metrizamide myelography risk factors: a pseudopsychiatric case presentation.

A case of neurologic sequelae from intrathecal metrizamide is presented. The patient had a convulsion, became comatose, and transiently developed mutism and hemiparesis, with eventual full recovery. Metrizamide is generally safe, but side effects do occur, and they may require clinical attention and follow-up.

Adult↗

Conditioned place preference: an evaluation of morphine's positive reinforcing properties.

The place-preference paradigm was evaluated as a measure of morphine's positive reinforcing properties. Previous place-preference studies obtained a morphine place preference of 26%-63%. In order to examine whether differences in procedure may account for this scatter, the present experiment investigated whether there is any difference in the absolute magnitude of preference when animals are conditioned on their non-preferred side of the box or when animals are randomly assigned to the side of conditioning. Furthermore, the number of conditioning days was extended with 3 intervening test days, and drug doses were doubled following each test day. The results showed no significant difference between conditioning animals on their non-preferred side or randomly assigning them to the side of conditioning. However, by extending the number of conditioning days, as well as by following the drug regimen used, the animals showed a greater magnitude of preference than that observed in previous studies. The implications of these findings for the usage of this paradigm as a measure of morphine's positive reinforcing properties are discussed.

Animals↗

The binding of dietary protein by sorghum tannins in the digestive tract of pigs.

The effects of reconstitution of sorghums on dry matter, energy, protein and amino acid digestibilities, and the nature of protein binding by sorghum tannins during digestion were investigated. Grains from a high and a low tannin sorghum were reconstituted by adding 30% (wt/wt) distilled water to the grain and stored at 25 degrees C for 20 days with an acetic-propionic acid mixture added to deter fungal growth. Another lot of grain from the same sources was untreated and used as control. The sorghum grains were then incorporated at an 85% level in diets for a digestibility trial with pigs cannulated at the terminal ileum. The digestibilities of dry matter, protein and amino acids at the terminal ileum were lower than the corresponding values measured over the total digestive tract. Reconstitution improved the digestibilities of dry matter, energy, protein and amino acids in the high but not low tannin sorghum diets. The improvement in digestibility of individual amino acids ranged from 7.5 to 23.5%. The tannin-associated proteins were more hydrophobic than the dietary protein. The results suggest that hydrophobic bonding is important in the formation of tannin-protein complexes in the digestive tract of pigs.

Amino Acids↗

Effect of varying levels of dietary vitamin D3 on turkey hen egg production, fertility and hatchability, embryo mortality and incidence of embryo beak malformations.

Two hundred Large White turkey hens were fed diets varying in vitamin D3 supplementation (300, 900, or 2700 IU/kg feed) from day-old to 37 weeks of age. Hens receiving 300 IU vitamin D3/kg feed produced fewer eggs, which were lighter in weight and had thinner shells than those laid by hens receiving the higher levels of vitamin D3. Fertility was not affected by treatment; however, hatchability of eggs from hens fed 300 IU vitamin D3/kg feed was reduced by 48% from that of hens fed the two higher levels. A shortened upper mandible, which was detected in embryos during Week 4 of incubation, accounted for approximately 10% of the total embryo mortality and 49.5% of the embryo mortality, during Week 4. It appeared that hens fed the low vitamin D3 did not have adequate amounts of the vitamin to transport to the egg for normal embryonic development.

Animal Feed↗

Influence of maternal vitamin D3 carry-over on kidney 25-hydroxyvitamin D3-1-hydroxylase activity of poults.

The effects of maternal vitamin D3 carry-over to the poult and dietary vitamin D3 on kidney 25-hydroxyvitamin D3-1-hydroxylase (1-hydroxylase) (EC 1.14.13.13) activity were studied in poults from 6 days prehatching to 46 days of age. Large White female turkeys from day-old were fed diets with either 300, 900, or 2700 IU vitamin D3/kg feed. Progeny from each maternal group were fed diets with either 0, 300, 900, or 2700 IU vitamin D3/kg feed. Low maternal vitamin D3 carry-over increased kidney 1-hydroxylase activity in embryos and poults to at least 5 days of age. Low dietary vitamin D3 increased the enzyme activity over that of poults fed higher levels. Kidney 1-hydroxylase activity peaked at about 8 to 18 days to a level similar in all groups. This peak is coincident with the appearance of rickets often noted in the field. Maternal diet did not affect plasma calcium (Ca) but plasma inorganic phosphorus (Pi) decreased with decreasing maternal vitamin D3 up to 14 days of age. Plasma Ca increased at 14 days with higher dietary vitamin D3, as did plasma Pi from day 8. Plasma alkaline phosphatase increased with age to 18 days and then declined. Tibia ash increased with higher maternal vitamin D3 carry-over to 12 days and with higher dietary vitamin D3 after 12 days of age. Body weight was reduced with low maternal vitamin D3 carry-over until at least 2 weeks of age, after which the effect of progeny diet was highly significant; birds receiving 2700 IU vitamin D3/kg feed were almost twice as large as those receiving none. This study shows the importance of adequate maternal carry-over of vitamin D3 and its possible influence on the development of rickets in starting poults.

25-Hydroxyvitamin D3 1-alpha-Hydroxylase↗

Effects of vitamin D3, calcium, and phosphorus on growth and bone development of market turkeys.

A study was undertaken to determine the effects of maternal and poult nutrition on poult growth and bone development through to market age. Nicholas Large White turkey hens (200) were fed diets with 300, 900, or 2700 IU vitamin D3/kg from day-old to 37 weeks of age. Male poults (649 from Hatch 1 and 555 from Hatch 2) were fed diets containing .6 or 1.2% Ca; .4 or .8% available P; and 300, 900, or 2700 IU vitamin D3/kg to 4 weeks (Hatch 1) or 2 weeks of age (Hatch 2) in a complete factorial design. All Hatch 2 poults were given a "therapeutic" diet from 2 to 4 weeks, followed by normal grower diets from 4 to 24 weeks of age. Increasing the level of vitamin D3 in the hen diet increased weight at hatching and at 2 and 4 weeks, decreased mortality from 0 to 2 weeks, and increased bone ash percent and breaking strength and decreased the severity of rickets score at 2 weeks. Increasing the levels of Ca, P, and vitamin D3 in the poult diet gave reduced mortality from 0 to 2 weeks, increased weight at 2 and 4 weeks, increased bone ash percent and breaking strength, and decreased severity of rickets score at 2 and 4 weeks. Carcass fleshing score at 24 weeks was improved with 1.2% Ca. Conformation score and percent grade A carcasses increased linearly with level of vitamin D3 in the starter diet and were also improved by increasing the vitamin D3 in the breeder diet.

Animals↗

Nutrient deficiencies in broiler chicks: a demonstration project for undergraduate students.

A demonstration project is described that proved to be popular with undergraduate students enrolled in a senior level course on animal and poultry nutrition. A total of 100 male, day-old broiler chicks were housed in a Petersime battery brooder and used in a 3-week test. Students were responsible for the management and care of the birds throughout the test. The birds were allotted to 5 groups (4 replicates each of 5 birds per group) and the test involved the omission of calcium, phosphorus, vitamin D3, or sodium chloride from a nutritionally adequate diet for a period of 2 weeks. After that period, one pen of each group was repleted with the control diet. Feed consumption, liveweight, feed conversion efficiency, and tibia bone ash content were measured weekly. Deficiency signs of the nutrients were observed, and it was noted that sodium chloride had the most marked effect on growth. Phosphorus deficiency had the most severe effect on bone development and resulted in a high incidence of rickets. Repletion resulted in a marked response in all parameters measured and was most marked in the group deficient in sodium chloride.

Animals↗

Improvement of the nutritive value of high tannin sorghums for broiler chickens by high moisture storage (reconstitution).

Grains from three high and one low tannin sorghum cultivars were treated as follows: 1) untreated, no water was added, the dry grain had an average moisture content of 8% and 2) the moisture content of the grain was raised by adding 25% (w/w) distilled water to the grain. The treated grain was then stored for 10 or 20 days with a 2% level of acetic-propionic acid mixture (60/40, v/v) added to deter fungal growth. This treated grain was used in diets during a 3-week feeding trial with broiler chickens. High moisture storage (reconstitution) of high tannin sorghums decreased their extractable tannin content. Chickens fed diets containing these treated sorghums had improved weight grains (23 to 83 g) and feed efficiencies compared to birds fed diets containing the untreated grain. Treatment of low tannin sorghum did not improve weight gains. Reconstitution of high but not low tannin sorghums improved protein digestibility (6 to 16%) and dietary metabolizable energy (.1 to .3 kcal/g) for broiler chickens. There was a highly significant cultivar effect on leg scores, but the correlation between dietary tannin content and leg scores was low (r = .10), suggesting that tannin content was not a major factor in leg abnormality incidences shown. The improvement in weight grains, feed efficiencies, and protein digestibilities at 10 and 20 days storage periods was not different (P greater than .05), indicating that the benefits of high moisture storage were already obtained by 10 days.

Animals↗

Dietary level of fat, calcium, and vitamins A and D3 as contributory factors to rickets in poults.

Two experiments were conducted on dietary predisposition to rickets in poults. The first experiment compared fat type (corn oil or tallow), level of added fat (3.5 or 7%), vitamin D3 (900 or 2,400 IU/kg feed), and total calcium (.6, 1.2, or 3%) inclusion in the diet. Poults fed diets supplemented with corn oil had higher percentage tibia ash than poults fed tallow-supplemented diets. Vitamin D3 included at 2,400 IU/kg feed increased body weights significantly by 2 and 4 weeks of age and lowered plasma alkaline phosphatase (AP) at 2 and 4 weeks compared with diets containing 900 IU/kg feed. Tibia ash was significantly greater with the higher vitamin D3 supplementation at 2 weeks. At 2 weeks of age both low (.6%) and high (3%) levels of dietary calcium increased plasma AP, decreased tibia ash, and decreased body weight compared with diets containing 1.2% calcium. By 4 weeks of age, diets containing 1.2 and 3% calcium had no significant effects on body weight and plasma AP; however, tibia ash was significantly greater with these levels than with the .6% calcium diets. The second experiment compared level of dietary tallow inclusion (2.5 or 7%) and supplementary vitamin A (4,000, 16,000, or 44,000 IU/kg feed). The high tallow diets decreased tibia ash at 3 weeks, and the maximum supplementation of vitamin A significantly depressed body weight. Clinical rickets were first noted at 18 days of age. By 26 days of age the higher level of dietary fat and the highest level of vitamin A caused a significant increase in severity of rickets. The results suggested that rickets can be induced by high dietary levels of tallow and vitamin A.

Alkaline Phosphatase↗

Effects of chronic naltrexone on amphetamine locomotor activity.

Animals from two different populations of Wistar rats were chronically pretreated with naltrexone for 8 days. After a 2-day rest period, animals were tested with amphetamine for locomotor activity in the open-field with or without white noise (Day 2). The rats were similarly retested on Day 7 and Day 14. New colony animals showed a significant attenuation in amphetamine locomotor activity in the absence of noise only. In contrast, chronic naltrexone significantly decreased amphetamine activity in old colony animals only under noise conditions. The possibility of an inhibitory role opiate receptors on the dopamine neuro-transmission is discussed.

Amphetamine↗

Ruptured abdominal aortic aneurysm: an 11 year review.

This paper reviews experience over 11 years at Waikato Hospital of an aggressive approach to ruptured abdominal aortic aneurysms. The total hospital mortality was 51 percent. Of those reaching operation 34 percent died in hospital. This was reduced to 28 percent over the last five years of the survey. Features relating to the presentation, operative and postoperative management, and subsequent progress of patients are discussed.

Acute Kidney Injury↗