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Biomedical subjects

K A Turner

Publications and source records attributed to K A Turner.

At least 19 recordsLinked to original sources
PubMed1999

Effects of feeding high carbohydrate or high fat diets. 1. Growth and metabolic status of the posthatch poult following immediate or delayed access to feed.

Three experiments were conducted with turkey poults to determine the effects of diet and delayed placement on growth and selected aspects of carbohydrate metabolism. Immediately after hatch, poults were placed in batteries and allowed either immediate access to feed and water (FED) or feed and water withdrawal for 48 h (WH). In the first two experiments, diets contained a high proportion of carbohydrate from corn (CHO; 60% of diet) or a lower proportion of corn (26%) and 10% supplemental animal-vegetable fat (FAT). The WH poults weighed less than FED poults at 5 d postfeeding (DPF; P < or = 0.05) but not at 13 DPF. Similarly, poults fed the CHO diet were heavier 5 DPF, whereas poults fed the FAT diet were heavier at 13 DPF (P < or = 0.05). Regardless of feeding regimen (WH vs FED), all poults were nearly depleted of hepatic glycogen prior to feeding. At 2 DPF, poults fed the CHO diet had more hepatic glycogen concentrations compared with those fed the FAT diet (P < or = 0.002). In addition, one-half of the WH poults fed the CHO diet had plasma glucose concentrations in excess of 500 mg/dL at 2 DPF. In Experiment 3, similar feeding regimens and diets were used with the addition of a third diet containing a synthetic medium-chain triglyceride emulsion (MCT) as the supplemental fat source. Poults fed the FAT and MCT diets were 41 g heavier than poults fed the CHO diet at 13 DPF (P < or = 0.05). Similar to the results of Experiment 2, poults fed the CHO diet had increased hepatic glycogen concentrations at 2 DPF, and within the WH treatment at 2 DPF, 30% of the poults had plasma glucose concentrations in excess of 500 mg/dL. Metabolic consequences of delayed placement were also found. At both 4 and 7 DPF, WH poults had a reduced capacity for glucose clearance 60 min after a glucose load (250 mg; P < or = 0.05). The current experiments demonstrate that supplemental fat may ease the metabolic shift toward glycolysis after hatching, thereby improving growth through 2 wk of age.

Animal Feed↗
PubMed1999

Effects of feeding high carbohydrate or fat diets. 2. Apparent digestibility and apparent metabolizable energy of the posthatch poult.

An experiment was conducted with turkey poults to determine the apparent digestibility and derivation of ME from diets containing a high proportion of carbohydrate from corn (CHO; 60% of diet) or 10%) supplemental fat from an animal-vegetable blended fat (FAT) or a synthetic medium-chain triglyceride (MCT). Poults fed the FAT diet consumed more feed from 6 to 8 and 9 to 11 d of age than poults fed the CHO diet, intake of the MCT diet was intermediate. From 3 to 11 d of age, the percentage apparent digestibility of nonlipid DM by poults fed the CHO diet was greater than that observed for either the FAT or MCT diets (P < or = 0.05). The percentage apparent digestibility of lipid was consistently greater for poults fed the MCT diet (> or = 90%) and could be attributed to the high apparent digestibility of C8:0 (>95%), which accounted for 76% of total MCT dietary fatty acids. Over the course of the experiment, the mean percentage apparent digestibility of lipid in the CHO and FAT diets was 76.4 and 70.8%, respectively, and did not change with increasing age. The lower percentage apparent digestibility of lipid in the CHO and FAT diets was attributed to the low apparent digestibility of C16:0 (70.4, 52.7%) and C18:0 (58.4, 26.8%), respectively. The apparent digestibility of the polyunsaturated fatty acids, C18:2 (n-6) and C18:3 (n-3), was consistently high and ranged from 72 to 85% and 81 to 88%, respectively. The CHO diet resulted in an approximate 6% increase in determined AMEn compared with either the FAT or MCT diets. The results of this study showed that commercial feed-grade fats are poorly digested by very young poults. The digestibility of polyunsaturated fatty acids, however, was shown to be quite high, and the data suggest that vegetable oils containing high proportions of polyunsaturated fatty acids or alternative fat sources containing high proportions of medium-chain fatty acids could be well utilized by the very young poult.

Aging↗
PubMed1997

Ornithine decarboxylase activity in muscle, liver, and intestinal tissue of turkeys during a short-term feed withdrawal and following refeeding.

The activity of ornithine decarboxylase (ODC), an enzyme associated with cellular growth and protein synthesis, was examined in breast muscle, liver, and intestinal tissues of turkeys during a short-term period of feed withdrawal (FW) and following refeeding. Turkeys from a randombred control line were reared under standard management practices to 3 wk of age in battery brooders. Feed was then withdrawn from FW birds for a 48-h period, after which feed was consumed ad libitum. Control birds consumed feed ad libitum throughout the test period. Tissues were collected from 12 birds per treatment following 24 and 48 h of FW and at 6, 12, 24, and 48 h following refeeding for later determination of tissue ODC activity. Activity of ODC was greater in tissue from the small intestine than in liver tissue and both had greater activity than that exhibited by breast muscle. Short-term FW and refeeding produced differential responses in ODC activity of the three tissues examined. Feed withdrawal resulted in a reduction of ODC activity in intestinal tissue, whereas activity was unaffected for liver or breast muscle tissues. Compensatory increases in ODC activity were observed in liver and intestinal tissues; however, the increase was both more rapid and transitory in small intestine than in liver tissue. The ODC activity in breast muscle was largely unaffected by short-term FW and refeeding. Patterns of ODC activity in liver during FW and refeeding closely resembled patterns observed for absolute and relative liver weight. Thus, the results of the present experiment demonstrate that short-term FW and refeeding influence underlying growth mechanisms of supply organs, such as hepatic and intestinal tissue, in addition to affecting overall growth and muscle development.

Analysis of Variance↗
PubMed1996

Automated polymerase chain reaction product sample preparation for capillary electrophoresis analysis.

The analysis of crude polymerase chain reaction (PCR) products by capillary electrophoresis (CE) is often compromised due to the presence of a high concentration of salt. Salt interferes with the electrokinetic injection and induces localized heating within the column; hence, PCR products must be desalted or cleaned-up prior to CE analysis. A variety of commercial clean-up systems are available that have been traditionally used to prepare PCR products for cloning, sequencing and digestion with restriction enzymes. These systems were tested for their effectiveness in preparing PCR products for CE analysis and were evaluated based on CE resolution, salt removal, DNA recovery, processing time and cost. One particularly effective clean-up system, membrane dialysis, was automated using a robotic workstation.

Automation↗
PubMed1996

The evaluation of fast purification methods for preparing polymerase chain reaction (PCR) products for capillary electrophoresis analysis.

The analysis of crude polymerase chain reaction (PCR) products by capillary electrophoresis (CE) is often compromised by the presence of a high concentration of salt. Salt interferes with the electrokinetic injection and induces localized heating within the column, hence, PCR products must be desalted or cleaned-up prior to CE analysis. A variety of commercial clean-up systems are available that have been traditionally used to prepare PCR products for cloning, sequencing, and digestion with restriction enzymes. These systems were tested for their effectiveness in preparing PCR products for CE analysis and were evaluated based on CE resolution, salt removal, DNA recovery, processing time, and cost.

DNA↗
PubMed1995

Automated DNA purification and amplification from blood-stained cards using a robotic workstation.

A new method for the purification of DNA on blood-stained cards was developed. This method was implemented into a high-throughput automated system using a Biomek 1000 robotic workstation. In addition, the processes of DNA purification and amplification were coupled into a completely automated and uninterrupted prototype system, and the resultant PCR products generated by this system were subjected to automated desalting for capillary electrophoresis analysis.

Autoanalysis↗
PubMed1992

The effect of early protein restriction (zero to eight weeks) on skeletal development in turkey toms from two to eighteen weeks.

Turkey toms were fed protein- and lysine-deficient diets or protein- and lysine-adequate diets from 0 to 4 and 5 to 8 wk and similar diets from 9 to 18 wk. Beginning at 2 wk of age and at approximate 2-wk intervals thereafter, the length and width of the right tibia were measured in nine toms per treatment. The length and width of the femur were measured beginning at 8 wk. Three tibiae that were close to the average length for each age and treatment were selected for ashing. The top 25% (epiphyseal) and middle 10% (diaphyseal) segments from each of these bones were fat-extracted prior to ashing. Mean length of the tibia continued to increase throughout the experiment whereas tibia width reached a plateau at 16 wk. Femur length also continued to increase throughout the study whereas there were no significant changes in femur width after 16 wk. Compared with the control diet, the diet deficient in protein and lysine resulted in a significant decrease in tibia and femur width at all ages. There were no dietary effects on tibia length at 16 and 18 wk, however. There were no significant dietary effects on femur length after 14 wk. There were significant age effects but no significant dietary effects on epiphyseal or diaphyseal bone ash. Epiphyseal bone ash increased from 41 to 54% over the course of the study whereas diaphyseal bone ash increased only from 59 to 64%.

Animals↗
PubMed1990

The dimensional stability of elastomeric impression materials following disinfection.

Public awareness of infectious diseases has focused attention on the prevention of nosocomial disease. Difficulties in sterilizing impressions have led to chemical disinfection as an alternative. Recent literature indicated a lack of consensus between researchers about distortion caused by disinfection. A polysulfide, polyether, and vinyl polysiloxane were disinfected by immersion in iodophor, sodium hypochlorite, and glutaraldehyde. Distortion was evaluated by use of a stainless steel die (ADA specification No. 19). Linear dimension variations after disinfection were clinically insignificant.

Aldehydes↗
PubMed1989

An evaluation of porcelain strength and the effect of surface treatment.

This investigation evaluated the flexural strengths of five porcelains commonly used in the all-porcelain margin technique and the effect of surface treatment on the flexural strength. Thirty samples were made by using each of five different porcelain margin systems. The five porcelain groups were subdivided into groups of 10 each to allow the evaluation of three surface treatments. A three-point flexural test was used to test the specimens on a universal testing machine. Crystar shoulder porcelain with distilled water as the binder was significantly stronger than the other porcelains tested, and porcelain treated with an overglaze was stronger than porcelain treated with autoglaze or autoglaze and polish.

Dental Casting Technique↗
PubMed1986

Multiple cast post and cores for severely worn anterior teeth.

A technique has been presented to simplify the fabrication of multiple direct post and core patterns. When combined with techniques for indirect provisional restorations, this technique merely requires the fabrication of an additional plastic template to form the direct core patterns.

Acrylic Resins↗
PubMed1985

Inhibition of penicillin-binding protein 3 of Escherichia coli K-12. Effects upon growth, viability and outer membrane barrier function.

A temperature-conditional, cell-division mutant of Escherichia coli K-12 possessing a thermolabile penicillin-binding protein (PBP) 3 was isolated. The mutant phenotype was due to a lesion in the pbpB gene. This mutant, and leu+ pbpB co-transductants of E. coli C600 grew as rods at 30 degrees C but were converted to filaments at 42 degrees C upon denaturation of PBP3 and concomitant cessation of cell division. These strains have been used to study the consequences of the specific inhibition of PBP3 of E. coli K-12 upon growth, viability and outer membrane integrity. Our results indicate that the singular inhibition of PBP3 is bactericidal in E. coli K-12, even though the turbidimetric response of the bacteria in broth culture suggests bacteriostasis. Furthermore, filament formation is accompanied by disruption of outer membrane barrier function, as witnessed by the rapid leakage of periplasmic beta-lactamase. This latter finding was confirmed by observing the lytic effect of a sub-inhibitory concentration of cefsulodin on filaments of E. coli K-12 induced by PBP3-specific beta-lactams. The impact of these results upon the testing of beta-lactam sensitivity of E. coli K-12 is discussed.

Acyltransferases↗