Search PubMed⌕ Search

Biomedical subjects

L G Young

Publications and source records attributed to L G Young.

At least 37 records · Page 2Linked to original sources
PubMed1992

Treatment acceptability ratings for sexual offenders: effect of diagnosis and offense.

Case description methodology was used to obtain treatment acceptability ratings for mentally retarded and nondisabled (normal) sex offenders across three different offenses (masturbation, rape, and child fondling) and eight interventions. For both diagnostic groups, social-sexual skills training (SST) was the most acceptable treatment except in cases of rape, fondling of a minor, and public masturbation. For these offenses, SST was as acceptable as aversive treatments and incarceration. The addition of a positive treatment component to a preexisting aversive intervention did not result in significantly different acceptability ratings relative to ratings of aversive interventions alone. Respondent's history as a victim of sexual abuse did not affect treatment acceptability ratings for prison, medication, or use of noxious odors.

Adolescent↗
PubMed1992

Porcine skeletal muscle myofibrillar protein synthesis is stimulated by ractopamine.

Thirty-two 64-kg individually penned barrows were fed protein at 130 or 170 g/kg diet and ractopamine at 0 or 20 mg/kg in a randomized complete block design for 28 d. Fractional synthesis rates of myofibrillar, sarcoplasmic and connective tissue proteins in longissimus dorsi, biceps femoris and gastrocnemius muscles were examined by primed-continuous infusion of L-[ring-2,6-3H(N)]phenylalanine over a 4-h period. Fractional synthesis, accretion and breakdown rates of protein in the muscles were not affected by dietary ractopamine, regardless of whether estimated on the basis of plasma or tissue homogenate specific activity. Absolute rates of protein synthesis (P less than 0.05) and breakdown (P less than 0.1) in biceps femoris muscle were both elevated by ractopamine feeding at 170 g protein/kg diet. Also in the diet containing 170 g protein/kg, ractopamine increased (P less than 0.05) protein contents of longissimus dorsi and biceps femoris muscles. Dietary ractopamine increased (P less than 0.05) fractional rates of synthesis of myofibrillar but not sarcoplasmic proteins in longissimus dorsi and biceps femoris muscles of pigs fed the 170 g protein/kg diet. This result demonstrates that ractopamine treatment results in a stimulation of myofibrillar protein synthesis.

Adrenergic beta-Agonists↗
PubMed1992

Metabolic responses induced by isoproterenol in ractopamine-fed pigs.

Ractopamine at 0 or 20 mg/kg and protein at 130 or 170 g/kg diet were used in a 2 x 2 factorial experiment arranged in six randomized complete blocks of 64-kg pigs. On d 21, pigs were intravenously administered 1 microgram isoproterenol/kg body wt, and blood was sampled at -60, -30, 0, 5, 10, 15, 20, 30, 60, 90 and 120 min relative to injection. Subcutaneous adipose tissue samples were used to measure in vitro lipolytic and lipogenic responses to isoproterenol. Regardless of dietary treatment, isoproterenol challenge induced a rapid increase in plasma glucose, nonesterified fatty acids and lactate concentrations. Pigs fed ractopamine in a 170 g protein/kg diet had a greater plasma nonesterified fatty acid response to isoproterenol challenge than pigs fed the same dietary protein but without ractopamine. There was an attenuation of plasma glucose and lactate responses to isoproterenol by chronic ractopamine feeding at both protein concentrations. Ractopamine feeding had no effect on basal lipolysis and lipogenesis in vitro. Lipolysis was elevated and lipogenesis was depressed by isoproterenol. The results suggest that ractopamine, when it improves performance and carcass composition, elicits a shift in metabolism involving increased use of fat for oxidation and potentiates the responsiveness of the adipose tissue to lipolytic cues.

Adipose Tissue↗
PubMed1992

Microbial transformation of deoxynivalenol (vomitoxin).

Microbial inocula from rumen fluid, soil, and contents of the large intestines of chickens (CLIC) and of swine (SLIC) were tested for their ability to transform deoxynivalenol (vomitoxin) in vitro. Microorganisms in (CLIC) completely transformed pure vomitoxin, and this activity was retained through six serial subcultures. No alteration of the toxin by incubation with SLIC was detected, whereas 35% of the vomitoxin was metabolized in the original culture of rumen fluid and 50% was metabolized by the soil sample, though metabolism was decreased in subsequent subcultures of either sample. A single metabolite was isolated and identified as deepoxy vomitoxin. The increase in concentration of deepoxy vomitoxin in the culture medium corresponded with the decrease in vomitoxin concentration. The vomitoxin transformation rate was not affected by either the ratio of CLIC to vomitoxin (5 to 0.2 g of CLIC per mg of vomitoxin) or the initial concentration of vomitoxin (14 to 1,400 ppm) in the medium. Biotransformation of vomitoxin was completely inhibited when the pH in the medium was lowered to 5.20. Sodium azide at a 0.1% (wt/vol) concentration in the medium blocked the transformation of vomitoxin, suggesting that the deepoxidation of vomitoxin is an energy-dependent process. About 50% of the vomitoxin in moldy corn in culture medium was transformed by microorganisms from CLIC. The vomitoxin transformation rate in moldy corn was not affected when the concentration of CLIC changed from 0.2 to 0.8 g/ml of medium. Vomitoxin in the moldy corn was not transformed when CLIC were added to corn without culture medium.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

Binding of sperm-reactive antibodies in human sera to surface-associated antigens on human sperm compared by indirect immunobead, immunofluorescence, and immunogold assays.

Human sera were identified as positive or negative for sperm-reactive antibodies in a solid-phase enzyme-linked immunosorbent assay (ELISA). Of these, 28 positive and 22 negative sera were blind-coded and used as first antibody to compare three immunoassays, a modified liquid-phase indirect immunobead assay (IBA); a liquid-phase indirect immunofluorescence assay (IFA); and a solid-phase indirect immunogold assay (IGA). These three immunoassays perform both as sperm-reactive antibody detection assays and as sperm-associated antigen localization assays. As antibody detection assays, the IBA, IFA, and IGA gave 37, 27, and 28 positives and 13, 23, and 22 negatives, respectively. The usefulness of the IBA as an antigen localization assay was limited by the size of the marker, while the smaller IFA and IGA markers enabled increased resolution of binding patterns of sperm-reactive antibodies to surface-associated sperm antigens. Although the antigen-antibody binding patterns were almost identical for IFA and IGA, suggesting the same sperm-associated antigens were detected by both assays, the IGA reaction product was stable, higher in resolution, and visible by light microscopy.

Antibodies↗
PubMed1990

Manipulation of porcine carcass composition by ractopamine.

The effect of dietary ractopamine and protein level on growth performance, individual muscle weight and carcass composition of finishing pigs were evaluated in two experiments. Twelve barrows and 12 gilts (Exp. 1) and 32 barrows (Exp. 2) with an average initial weight of 64 kg were penned individually and offered ractopamine at 0 or 20 ppm in diets containing 13 or 17% CP in 2 x 2 factorial experiments for 28 d. In both experiments, dietary ractopamine improved daily gain (P less than .1) and gain-to-feed ratio (P less than .05) at 17% dietary protein level but depressed these response criteria at 13% protein level. Leaf fat was reduced (P less than .05) and longissimus muscle depth was increased (P less than .1) by feeding ractopamine regardless of dietary CP concentration. Longissimus, psoas major, semitendinosus, biceps and quadriceps femoris (P less than .05) and tensor facia latae (P less than .1) muscles were 8 to 22% heavier with ractopamine feeding at 17% dietary CP level. Results from both trials suggest that ractopamine improves growth rate and carcass leanness at the higher dietary protein level but improves only carcass leanness at the lower protein level.

Adipose Tissue↗
PubMed1990

Effects of feeding zearalenone to sows on rebreeding and pregnancy.

Two trials were conducted with a total of 91 lactating sows fed 0, 5 or 10 ppm dietary zearalenone (Z) and 0 or 15% dietary alfalfa in a factorial arrangement to evaluate their influence on reproductive performance to 40 d postbreeding. Feeding of Z did not alter the proportion of sows returning to estrus; however, the weaning-to-estrus interval increased when increased dietary Z was fed in Trial 2, with a similar trend at the highest level in Trial 1. The average number of fetuses per sow with fetuses tended to decrease (P less than .05) with increasing dietary Z in Trial 2, but not in Trial 1. Embryonic mortality did not appear to increase when the ratio of fetuses to corpora lutea was compared in sows with fetuses in Trial 1, but it did increase in Trial 2. The trend to increased numbers of bred sows that were non-pregnant at slaughter when dietary Z increased in Trial 1 was not observed in Trial 2. Dietary dehydrated alfalfa meal did not appear to modify the effects of Z in these trials.

Animal Feed↗
PubMed1989

In vitro Na+,K+-ATPase (EC 3.6.1.3)-dependent respiration and protein synthesis in skeletal muscle of pigs fed at three dietary protein levels.

1. Eighteen pigs were offered diets containing 130, 170 or 210 g protein/kg with three barrows and three gifts per diet from 20 to 60 kg live weight. Oxygen consumption, Na+,K+-ATPase (EC 3.6.1.3)-dependent and -independent respiration and protein synthesis were measured in vitro in intercostal and sartorius muscle preparations from these pigs. 2. Increasing dietary protein concentration increased (P less than 0.01) daily gain and dissectible muscle in carcass. 3. O2 consumption and Na+,K+-ATPase-dependent respiration of the intercostal and sartorius muscles increased linearly (P less than 0.01) with increase in dietary protein concentration. The requirement for the support of the transport of Na+ and K+ across the cell membrane in these muscles, on average, accounted for 22-25% of the O2 consumption. 4. Synthesis rate (mg/g per d) of protein in the sartorius muscle increased (P less than 0.05) from 3.05 to 5.07 and increased (P less than 0.1) from 2.57 to 4.06 in the intercostal muscle as dietary protein increased from 130 to 210 g/kg diet. 5. Regression of Na+,K+-ATPase-dependent respiration against protein synthesis in each of intercostal and sartorius muscles showed a linear relation, an attestation of a close link between productive processes and auxiliary energy expenditure.

Animals↗
PubMed1989

Dietary protein-induced changes in porcine muscle respiration, protein synthesis and adipose tissue metabolism.

Growth rate, physically separable tissues of the ham and loin, heat production, skeletal muscle respiration and protein synthesis, and lipogenesis and lipolysis in s.c. adipose tissue were measured in a single experiment in which pigs were offered a 13 (n = 8), or 21% (n = 6) protein diet from 20 to 100 kg live weight. Pigs that were fed the 13% protein diet gained body weight slower, ate less, converted feed less efficiently and took 31 d longer to reach 100 kg live weight. Fat depth (cm) was greater (P less than .05) and loin eye area (cm2) was less (P less than .01) in pigs fed the 13% protein diet (2.6 vs 2.3 and 29.8 vs 35.3). Pigs that were fed the 13% protein diet had lower (P less than .05) ham and loin separable muscle and greater (P less than .05) ham and loin separable fat. The mean heat production was less (P less than .05) in pigs offered the 13% (22.49) vs 21% (24.63 MJ/d) protein diets. In the intercostal muscle preparation, total and Na+,K+-ATPase-dependent respiration (microliter O2.mg-1.h-1) were lower (P less than .05) in pigs offered the 13% (2.39 and .41) vs the 21% (3.89 and .68) protein diets. The energy used for the support of Na+ transport across membrane accounted for approximately 17% of muscle respiration. Absolute rates of protein synthesis in the muscle preparations were lower (P less than .01) at 13 than at 21% dietary protein. Lipogenesis in s.c. adipose tissue was not affected by dietary protein level. There was no difference in basal and norepinephrine-stimulated lipolysis between the two dietary protein levels.

Adipose Tissue↗
PubMed1987

Changes in binding of a 27-kilodalton chimpanzee cauda epididymal protein glycoprotein component to chimpanzee sperm.

Motility patterns of caput epididymal chimpanzee sperm, caput epididymal chimpanzee sperm incubated in vitro with chimpanzee cauda epididymal fluid, and cauda epididymal chimpanzee sperm were assessed quantitatively. Sperm recovered from the caput epididymis showed no motility, whereas sperm recovered from cauda epididymis showed progressive forward motility. After incubation in cauda fluid, approximately 25% of caput epididymal sperm showed some motile activity. Electrophoretic analysis of 125I-labeled sperm plasma membrane preparations revealed that the surface of caput epididymal sperm, incubated in cauda fluid, was modified by the appearance of a major protein-glycoprotein surface component with an apparent molecular weight of 27 kilodaltons (kD). THis 27-kD component was not detected on caput epididymal sperm incubated in buffer or in caput fluid. However, it was present in cauda fluid and on cauda epididymal sperm. Binding to caput epididymal sperm was cell specific in that chimpanzee erythrocytes incubated in cauda fluid did not bind this 27-kD cauda fluid component. Motility patterns of ejaculated chimpanzee sperm and of ejaculated chimpanzee sperm incubated in the uterus of adult female chimpanzees also were assessed quantitatively. Ejaculated sperm showed progressive forward motility, whereas in utero incubated ejaculated sperm showed hyperactivated motility typical of capacitated sperm. Electrophoretic analysis of 125I-labeled sperm plasma membrane preparations revealed the loss of a 27-kD component from the surface of ejaculated sperm after in utero incubation. No significant change in the 125I-distribution pattern was detectable when ejaculated sperm were incubated in buffer. These results suggest that the lumenal fluid component, which becomes adsorbed to the surface of chimpanzee sperm during maturation in the epididymis and which is removed from the surface of mature chimpanzee sperm in the female reproductive tract, affects sperm motility.

Animals↗
PubMed1986

Low concentrations of zearalenone in diets of mature gilts.

Four groups of sixteen gilts were each individually fed diets containing 0, 3, 6 or 9 ppm pure zearalenone starting the day after they exhibited puberal estrus. They were artificially inseminated twice at subsequent heat periods. Fifteen of the 30 gilts not exhibiting estrus within 80 d of the start of the experiment were slaughtered and their reproductive tracts examined. The remaining 15 gilts that did not return to estrus were fed the control diet after 80 d to determine the effect on return to estrus. Eighty-eight percent of the gilts fed 6 or 9 ppm zearalenone became pseudopregnant as confirmed by plasma progesterone levels and(or) examination of their reproductive tracts. However, three animals fed the two higher levels of zearalenone conceived and farrowed. No conclusions can be made regarding the effect of zearalenone on litter size due to the relatively few numbers of gilts fed the higher levels of zearalenone that farrowed. Gilts fed diets containing 6 or 9 ppm zearalenone returned to estrus spontaneously (n = 7) or following injection of cloprostenol (n = 8) approximately 45 d after the removal of zearalenone from their diet.

Animals↗
PubMed1986

Low concentrations of zearalenone in diets of boars for a prolonged period of time.

Thirty-two boars were fed diets containing 0, 3, 6 or 9 ppm zearalenone from 32 d of age up to 145 or 312 d of age. Rate of gain, feed intake and gain:feed were not significantly different among treatments. Feeding of diets containing 9 ppm zearalenone did not affect the libido in seven boars. There was a tendency for boars fed 9 ppm dietary zearalenone to produce lower total and gel free volumes of semen, with lower total motile sperm; however, only the percent motility of the sperm was reduced (P less than .05).

Animals↗
PubMed1986

Effects of feeding hens a high level of vomitoxin-contaminated corn on performance and tissue residues.

A balance experiment was conducted with hens fed a high level of vomitoxin (V) to study the effect on live performance, egg quality, and tissue residues of V. Twenty Single Comb White Leghorn (SCWL) hens, approximately 26 weeks of age, were individually housed in metabolic cages and fed a control (C) or V (82.8 mg/kg) diet for 27 days. No significant differences were observed in feed consumption, body weight gain, egg production, egg weight, haugh units, shell deformation, or egg shell thickness between treatments. No gross pathological lesions were observed in the oral cavity, proventriculus, small or large intestine, liver, spleen, heart, or kidney. Small erosions were present in the gizzard mucosa of birds fed the V-diet. No significant V residues were found in the yolk, albumen, egg shell, liver, kidney, thigh, or breast muscle, but levels of approximately 20 ppb were found in the gizzard. About 4.2% of the total V consumed by hens were recovered in the feces.

Animals↗
PubMed1985

Surface changes in chimpanzee sperm during epididymal transit.

Intact chimpanzee caput and cauda epididymal sperm, sperm cell lysates, and caput and cauda epididymal fluid were radiolabeled by enzymatic iodination with lactoperoxidase and Na125 I and were compared by sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis. Caput epididymal sperm showed nine labeled macromolecular components of 90, 64, 56, 48, 38, 31, 20, 18 and 16 Kd and cauda epididymal sperm showed eleven macromolecular components of 90, 64, 55, 47, 42, 33, 27, 18, 17, 15 and 11 Kd. Six of the components labeled on caput sperm (90, 64, 56, 48, 18 and 16 Kd) were detected in equal amounts of cauda sperm and two (38 and 20 Kd) were detected at greatly reduced labeling intensities. In the cauda epididymidis, four new components (33, 27, 17 and 11 Kd) became prominent features of the sperm surface. Analysis of labeled caput and cauda sperm cell lysates resolved components distinct from those detected on sperm surfaces. Electrophoresis of caput epididymal fluid showed five labeled components of 66, 56, 47, 41 and 37 Kd, while electrophoresis of cauda epididymal fluid showed eight labeled components of 92, 66, 56, 48, 31, 27, 24 and 11 Kd. Three components (66, 56 and 47 Kd) were present in both caput and cauda fluid, two (41 and 37 Kd) in caput fluid only, and five (92, 31, 27, 24 and 11 Kd) in cauda fluid only. Components of 37 Kd were labeled in caput fluid and on caput sperm but not on cauda sperm, whereas components of 27 Kd and 11 Kd were labeled in cauda fluid and on cauda sperm but not on caput sperm. These data show that chimpanzee sperm undergo extensive surface modifications during epididymal maturation and that some of these modifications may be related to exogenous proteins/glycoproteins in epididymal fluids.

Animals↗