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Biomedical subjects

R L Moser

Publications and source records attributed to R L Moser.

At least 19 recordsLinked to original sources

Coronary artery plaque burden and perioperative cardiac risk.

BACKGROUND: Electron-beam computed tomography-derived coronary calcium score correlates with the morphologic severity of coronary artery disease, reflecting both global atherosclerotic plaque formation and coronary artery luminal narrowing. The current study examines the impact of coronary atherosclerotic plaque burden, measured by coronary calcium score, on the potential for perioperative myocardial cell injury, as assessed by cardiac troponin T elevations in patients undergoing elective vascular surgery. The authors further investigated whether perioperative myocardial cell injury in those patients adversely affects noninvasive measures of left ventricular systolic function, such as ejection fraction and wall motion score. METHODS: Fifty-one consecutive patients scheduled for vascular surgery were enrolled in this prospective study. In addition to standard preoperative evaluation, including patient history and physical examination, electron-beam computed tomography scan, 12-lead electrocardiography, and transthoracic echocardiography were performed on the day before surgery. Subsequent evaluations on postoperative days 2 and 7 included transthoracic echocardiography and 12-lead electrocardiography. Cardiac troponin T determinations were performed on the day before surgery, immediately preoperatively, and on postoperative days 1, 2, 3, and 7. RESULTS: The median coronary calcium score of the 51 patients was 997.0 (25th percentile, 202.5; 75th percentile, 1,949.5). Cardiac troponin T elevations exclusively occurred in patients with a coronary calcium score greater than 1,000. The six patients (12%) with perioperative cardiac troponin T elevations had a 2.5-fold higher coronary calcium score than those without cardiac troponin T elevation (P = 0.021). In these patients, the ejection fraction decreased from 61 +/- 10% to 52 +/- 13% (mean +/- SD) on postoperative day 2 and was 54 +/- 16% on postoperative day 7 (P = 0.022). CONCLUSION: A high electron-beam computed tomography coronary calcium score, reflecting substantial coronary plaque burden, carries an increased risk for myocardial cell injury after vascular surgery. In these patients, myocardial damage may result in deterioration of global systolic left ventricular function.

Aged↗

[Postoperative delirium: risk factors, prophylaxis and treatment].

After surgical operations delirium can occur as a serious and possible lethal complication in about 5-15% of patients. Additionally, risk factors such as old age, polymedication, organic and psychiatric diseases raise the incidence. After open-heart and orthopedic surgery more than half of the patients are affected. Delirium has negative effects on postoperative mobilization and reconvalescence and prolongs treatment on the ward. It is discussed in the literature that delirium may induce dementia in older patients. The correction of metabolic and electrolyte imbalances, as well as the therapy of neurologic and psychiatric diseases, belongs to prophylactic treatment. Environmental conditions which facilitate reorientation of the patient after operation have beneficial effects. Some success has been achieved by using the nootropic substance piracetam as a prophylactic. In acute treatment, the butyrophenon-neuroleptic haloperidol is the drug of choice. In delirium caused by intoxication with anticholinergic agents, physostigmin is indicated. Benzodiazepines, clonidine and clomethiazole are used in particular for the treatment of withdrawal delirium.

Aged↗

Limiting order of amino acids in a low-protein corn-soybean meal-whey-based diet for nursery pigs.

Three trials were carried out with pigs between 5 and 8 wk of age to determine the limiting order of amino acids in a 13.5% CP corn-soybean meal-based diet containing 8% dried whey. The positive-control diet was a 19.2% CP corn-soybean meal-based diet (1.15% lysine), also with 8% dried whey. Amino acid additions to the low-protein, negative-control diet were based on levels needed to accomplish 110% of ideal ratios (to lysine, set at 1.15%). In Exp. 1, the addition of an amino acid mixture containing Lys, Trp, Thr, Met, Ile, and Val to the low-protein diet increased (P<.05) gain and gain: feed ratio, and these response traits were not different from those of pigs fed the 19.2% CP positive-control diet. Single deletion of Lys from the supplemental amino acid mixture depressed performance to a greater (P<.05) extent than single deletion of any of the other amino acids. Single deletions of Trp, Thr, Met, or Val decreased (P<.05) performance in a similar but lesser magnitude than the decrease caused by Lys deletion, whereas Ile deletion was without effect. Experiments 2 and 3 were designed to evaluate the limiting order of AA beyond Lys in the low-protein diet. Neither His nor Glu were found to be deficient, and, as in Exp. 1, deletion of Trp, Thr, Met, or Val from the supplemental amino acid mixture resulted in performance depressions (P<.05) that were similar. The results suggest that Lys is first-limiting and Trp, Thr, Met, and Val are equally second-limiting in a reduced protein (13.5% CP) corn-soybean meal-based diet with 8% whey for 10-kg pigs.

Amino Acids↗

Influence of gilt age and body composition at first breeding on sow reproductive performance and longevity.

Regression analysis was used to evaluate the effects of gilt age and body composition at first breeding on sow performance over three parities. Eighty-seven Yorkshire x Landrace F1 gilts were used. Variation in age and body composition at first breeding was obtained by breeding gilts at puberty, second, or third estrus and by providing those gilts bred after puberty one of four nutritional regimens from puberty until breeding: 1) 2.7 kg/d of a 14.3% CP, 3.5 Mcal ME/kg diet (H), 2) maintenance ME and CP/d (M), 3) half-maintenance ME and CP/d (1/2M), and 4) M or 1/2M until anestrus, then 2.27 kg/d of a 14.0% CP corn-soybean meal diet until first breeding. Body composition at first breeding was determined using live weight, backfat thickness, and deuterium oxide space as variables in prediction equations. All females were treated similarly after first breeding. Age and body composition at first breeding were not related (P > .10) to litter size at birth or weaning in parities 1, 2, 3, or overall. Increasing age at first breeding was related to small increases in pig birth weights (P < .001) in parity 1 and average pig weaning weight (P < .001) in parities 1, 2, and overall. Body composition of gilts at first breeding was not related (P > .10) to pig birth weights and was inconsistently related to pig weaning weights in parities 2 and 3 (P < .001). Females heavier at first breeding remained heavier (P < .01) throughout the experiment. Age and body composition at first breeding were not different (P > .10) for gilts completing three parities (n = 53) compared with gilts failing to complete three parities (n = 34). Results show no large effects of gilt age or body composition at first breeding on sow productivity and longevity over three parities.

Aging↗

Body composition of gilts at puberty.

The relationship between body composition and the occurrence of puberty was evaluated using 93 Yorkshire x Landrace gilts. At approximately 60 d of age gilts were purchased and placed in a heated confinement unit where they were housed for the duration of the study. Ad libitum access to feed was provided throughout the study. Gilts were moved, mixed, and initially exposed to mature boars at approximately 120 d of age to encourage the earliest possible occurrence of puberty. Empty body weights of water, fat, protein, and ash at puberty were estimated using a deuterium dilution technique and prediction equations developed for this gilt population. There was considerable variation in age, weight, and all measures of body composition at puberty. Gilts were 138 to 240 d old and weighted 64.9 to 150.8 kg. Backfat thickness ranged from 17.5 to 44.0 mm. Gilts were composed of 32.4 to 64.3 kg of water, 15.6 to 53.9 kg of fat, 9.03 to 20.56 kg of protein, and 1.24 to 3.10 kg of ash. The coefficient of variation for fat to lean ratio at puberty was 15.39%. Linear and quadratic regressions showed that lifetime (birth to puberty) growth rate was not related to age at puberty (P > .10). Based on the variation in body composition observed it was concluded that the occurrence of puberty in gilts given ad libitum access to feed during rearing and initially exposed to mature boars at approximately 120 d of age was not related to certain minimum threshold amounts of body tissues or to a specific rate at which body tissue reserves were accumulated.

Animals↗

In vivo estimation of body composition of mature gilts using live weight, backfat thickness, and deuterium oxide.

Thirty-seven Duroc x (Yorkshire x Landrace) (DYL) and 21 Yorkshire x Landrace (YL) gilts were used to develop equations that predict body composition of replacement-age breeding swine. Before slaughter, gilts were weighed, ultrasonically scanned for 10th rib backfat thickness, and infused with D2O (.25 g/kg live weight). The D2O space (kilograms) was calculated from body water D2O concentration determined at equilibrium (150 and 210 min after infusion). Regression models predicting empty body (Eb) components for DYL and YL groups were fitted using all possible variable combinations (D2O space, live weight, and[or] backfat depth). Variables selected in best-fit models for Eb water, protein, fat, and ash for data from DYL gilts differed from variables selected from data from YL gilts. Average prediction errors (kilograms; [predicted residual sum of squares divided by n]1/2) of best-fit equations were 2.37, 2.03 (Eb weight), 2.36, 1.66 (Eb water), 1.07, .47 (Eb protein), and 2.76, 2.89 (Eb fat) for DYL and YL data sets, respectively. Cross-validation by applying DYL equations to YL data, and vice versa, resulted in larger prediction errors. Likewise, larger errors were obtained when equations published elsewhere were applied to DYL and YL data sets. No cited source provided a set of equations that consistently minimized prediction errors of all Eb components of both DYL and YL gilts. Results indicate that prediction equations using D2O space, live weight, and(or) backfat thickness are accurate in estimating body composition only in animals physiologically resemble the population in which the equations were derived.

Adipose Tissue↗

Pharmacological evidence for the release of galanin from rat stomach.

The neuropeptide galanin has been shown to occur in nerve fibres in the circular muscle layer of the rat stomach. The present experiments aimed at demonstrating a functional correlate for this observation by testing the motor effects of galanin on circular strips of the rat gastric corpus in vitro. Exogenous galanin elicited only small contractions of the smooth muscle which were dose-related but did not show a clear sigmoid dose-response relationship. These responses were resistant to atropine plus guanethidine or TTX. When the muscle strips were electrically stimulated, they showed pronounced rebound contractions after the end of the stimulus. These rebound contractions were significantly reduced by either desensitizing the strips to galanin or by addition of spantide. It is concluded that galanin is released from the myenteric plexus in the stomach and acts to modulate gastric contractions either postsynaptically or by modifying the release of tachykinins.

Animals↗

Body composition of postpubertal gilts at nutritionally induced anestrus.

An experiment using comparative slaughter was conducted to examine the relationship between occurrence of nutritionally induced anestrus in postpubertal gilts and chemically determined body composition and body composition changes. Thirty-nine Duroc x (Yorkshire x Landrace) gilts, each having experienced three or more estrous cycles, were used. Nine gilts were chosen randomly, weighed, ultrasonically scanned for 10th rib backfat thickness, and slaughtered to determine initial body composition. Remaining gilts were allotted randomly to five dietary treatments, four characterized as severely energy restrictive (RES; .25, .50, .75, and 1.0 mcal of ME/d) and a control (3.4 Mcal of ME/d). Dietary treatments provided equal amounts of protein (50 g), minerals, and vitamins daily. Individual serum progesterone levels were determined every 3 d using RIA and gilts were considered anestrous when concentrations were < 1.0 ng/mL for four consecutive samples (9 d). All RES gilts became anestrous, and gilts restricted more severely tended (P = .22) to do so more quickly. Days to anestrus were 66.0 +/- 12.0, 77.4 +/- 13.1, 84.5 +/- 12.0, and 86.5 +/- 12.0 for treatments .25, .50, .75, and 1.0, respectively. Among RES treatments there were no linear, quadratic, or cubic effects of ME intake (P > .10) on the quantity of body protein or fat lost, or on the quantity of body protein or fat remaining at anestrus. However, individual body protein and body fat contents of RES gilts at slaughter revealed that anestrus occurred at a wide range of body compositions, from 13.4 to 20.2 kg of protein and .36 to 27.0 kg of fat. This wide range of individual values suggests that estrous activity in the mature gilt is not controlled by specific threshold levels of body reserves.

Adipose Tissue↗

Estrous cycle characteristics of postpubertal gilts approaching anestrus due to limited dietary energy intake.

Twenty-nine Duroc x (Yorkshire x Landrace) gilts, approximately 9 mo of age and each having experienced at least three estrous cycles, were allotted randomly to five dietary treatments. Each treatment provided a different daily intake of metabolizable energy: .25, .5, .75, 1.0 Mcal (severely restrictive [RES]; chosen to cause cessation of estrous cycles) or 3.4 Mcal (control; designed for maintenance of estrous cyclicity). Blood samples were drawn by venipuncture every 3 d and sera were assayed for progesterone (P4) concentration. Estrous cycle length was estimated by defining d 0 as the last day when serum P4 concentrations were < 1 ng/mL before increasing to > 1 ng/mL. Gilts were considered acyclic when serum P4 levels remained < 1 ng/mL for four consecutive samples (9 d). Anestrus occurred after 78.7 +/- 6.1 d in all RES gilts (n = 23) and in one control on d 24. Compared with the control treatment, RES treatments resulted in longer (P < .05) average estrous cycles (21.0 +/- .2 vs 20.2 +/- .3 d) and greater (P < .05) mean serum P4 concentrations (13.7 +/- .4 vs 11.4 +/- .8 ng/mL). There were no differences in P4 or cycle length measurements among RES treatments. Cycle duration and serum P4 concentrations of the final estrous cycle before anestrus were similar to those of previous cycles. It is concluded that severe energy restriction caused elevated serum P4 concentrations. Neither cycle length nor serum P4 concentration was notably altered as gilts neared anestrus.

Animal Nutritional Physiological Phenomena↗

Selective microscopic examination of gallbladders, hernia sacs, and appendices.

The usefulness of many "routine" medical procedures is being challenged in the health care atmosphere of today. This study was undertaken to determine the utility of routine microscopic pathologic examination of three frequently submitted surgical specimens. Pathology reports of 39,568 consecutive specimens, 17,105 appendices, 14,654 hernia sacs, and 7,809 gallbladders, submitted over a 49-year period, were reviewed. Microscopic examination of these tissues detected few unexpected findings. In those instances in which unexpected findings were discovered the primary surgery was curative or additional surgery would not have altered the prognosis. When careful, thorough gross examination by the surgeon and pathologist failed to disclose significant abnormalities or confirmed obvious disease such as inflammation, microscopic examination of these tissues might have been eliminated without a change in patient outcome. Although it could be argued that this microscopic pathologic correlation may be helpful for quality control and/or feedback of surgical decision making, the data indicate that gross examination alone may be sufficient in most cases, since unexpected microscopic findings are rare. The indications for microscopic examination of appendices, hernia sacs, and gallbladders are listed. Substantial savings of resources and time may be expected when selective microscopic examination is used.

Appendix↗

Effect of reduced growth rate on the prevalence and severity of osteochondrosis in gilts.

Ninety-six recently weaned gilts were assigned to 3 groups. Group-1 gilts were fed a corn-soybean meal diet ad libitum and were killed when they weighed 110 kg. Gilts in groups 2 and 3 were fed 70% of the feed consumed by group-1 gilts. Group-2 gilts were killed when they weighed 110 kg, and group-3 gilts were killed at the same age as group-1 gilts. At slaughter, the right pelvic and thoracic limbs from all gilts were removed, and the distal end of each femur and humerus was sectioned serially at 5-mm intervals. Articular-epiphyseal cartilage complexes from these sites were examined grossly, radiographically, and histologically. Effects of treatment (ad libitum vs limited energy intake) and average daily gain on the prevalence and severity of lesions were analyzed statistically, using chi 2 analysis, a categoric-modeling technique, analysis of variance, and correlation coefficients. Of humeri and femora, 49 and 70%, respectively, had lesions of osteochondrosis, and 86% of the gilts had a lesion at one or both sites. Group-2 gilts (killed at 110 kg, but approx 70 days older than group-1 gilts) had significantly lower prevalence (P = 0.009) and severity (P = 0.002) of osteochondrosis of the distal end of the femur than did gilts in groups 1 and 3. When each group was evaluated individually, gilts that had a higher average daily gain had an increased prevalence and severity of lesions.

Animal Feed↗

Effects of oral doses of corn oil and other factors on preweaning survival and growth of piglets.

Piglets were provided supplemental energy as oral doses of corn oil to find whether such treatment might improve survival or weight gains. A total of 1,840 piglets from 182 litters was used. Piglets were allotted to dosed and control treatments within litter on the basis of body weight. Dosed piglets received a total of 8 ml of corn oil in four doses during the first 48 h postpartum. The survival rate to weaning was high and not affected (P greater than .10) by the corn oil doses. Deaths of piglets low in birth weight were delayed by the fat doses, suggesting some utilization. The fat doses did not affect piglet weight gain. Factors affecting preweaning survival and growth of piglets were also evaluated using data from the same piglets. Specific factors investigated were sex, parity of dam, birth weight, litter size and the mean and standard deviation of piglet birth weights within litters. Male piglets were heavier at birth than females, but there was no sex effect on weight at 7 d or at weaning. Small males were less likely to survive to 3 d than were small females. Litters from primiparous sows were smaller at birth and weaning, but had lower percentages of stillbirths and of preweaning deaths than did those from multiparous sows. Piglets from primiparous sows were more uniform in birth weight. Piglets that were heavier at birth grew faster and were more likely to survive. Litter size affected growth but not survival of piglets. A heavier average birth weight in the litter reduced slightly the growth rate of individual piglets. An increase in variability of piglet birth weight within a litter was associated with an increase of the percentages of stillbirths and of preweaning mortality. A few litters accounted for a major portion of the mortality. Much of the variation in piglet mortality and growth was not explained by factors considered.

Animal Feed↗

Effect of age, weaning and diet on digestive enzyme levels in the piglet.

Thirty-seven pigs were used to evaluate the effects of age and weaning on the level of protease in the gastric mucosa and trypsin, chymotrypsin, amylase and lipase in the pancreas. There was a positive allometry of the pancreas and gastric mucosa associated with age and with weaning to a solid diet. Increases with age in total activity of chymotrypsin, trypsin, amylase and gastric proteases were due to increases in both tissue weight and enzyme activity per gram of tissue. A general depression in pancreatic enzymatic activities, but not in gastric proteolytic activity, was found during the first week following weaning. Forty pigs were used in a second trial to evaluate the effects of age and weaning diet on the same digestive enzymes. Total activity of all enzymes assayed increased with time postweaning. Increases in total activity of lipase and chymotrypsin were due primarily to increased pancreatic weight postweaning. Amylase, trypsin and gastric protease increases were due both to increased tissue weight and increased activity per gram of tissue. There were no effects of diet on the weight of gastric mucosa or the level of activity of the gastric proteases. Pigs fed a diet containing 20% whey had larger pancreases (P less than .10) at slaughter and a greater, but nonsignificant, mean activity per gram of pancreas for all pancreatic enzymes. It appears that the pig has sufficient pancreatic and gastric enzyme activity so that performance should not be limited, with the possible exception of the period shortly after weaning. However diet digestibility and subsequent pig performance may be more directly related to the extent of release of these enzymes into the intestine and the conditions that exist therein.

Aging↗

Integration of factors affecting sow efficiency: a modeling approach.

A dynamic, partially stochastic mathematical model describing the reproductive performance of a sow herd is presented. The model stimulates a herd that averages 17.27 sow days/pig produced, with a mean of 9.06 pigs weaned/litter and 2.327 litters produced/sow each year. Several alternative options are simulated. Of these, the ones that increase the litter size at weaning appear most beneficial in terms of both biological and economic efficiencies.

Animal Husbandry↗

Response of growing-finishing pigs to decreasing floor space allowance and(or) virginiamycin in diet.

Five hundred forty crossbred pigs were utilized in four trials (10 replications) at two stations to determine the separate and interacting effects of decreasing floor space allowance with or without the addition of virginiamycin to the diet on performance of growing-finishing pigs. Pigs were allowed .37, .33 or .28 m2/pig during the growing phase (23 to 55 kg) and .74, .66, .56 m2/pig during the finishing phase (55 to 100 kg) and fed either a corn-soybean meal control diet or the control diet plus 11 mg of virginiamycin/kg of diet. Floor space allowances were achieved by varying pen size, so the number of pigs and feeder space per pig were constant for all pens. During the growing phase, daily gain (P less than .01) daily feed intake (P less than .05) and feed conversion ratio (P less than .05) decreased as floor space allowance decreased. During the finishing phase and for the total test period, daily gain (P less than .01) and feed conversion ratio (P less than .05) were reduced but daily feed intake was not affected (P greater than .05) by restricted floor space allowance. The addition of virginiamycin to the diet had no effect on pig performance. The virginiamycin X floor space allowance interaction was not significant, suggesting that pigs fed a diet with or without virginiamycin responded similarly to restricted floor space allowance. The data suggest that the addition of virginiamycin to the diet was ineffective in overcoming the decrease in performance of growing-finishing pigs caused by crowded conditions.

Animal Feed↗