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Biomedical subjects

S E Williams

Publications and source records attributed to S E Williams.

At least 55 records · Page 3Linked to original sources
PubMed1994

Comparison of live and carcass equations predicting percentage of cutability, retail product weight, and trimmable fat in beef cattle.

Forty-four Hereford-sired steers were measured ultrasonically for backfat and longissimus muscle area between the 12th and 13th ribs before slaughter and visually appraised for fatness, overall muscling, and frame. Carcass measurements associated with USDA yield and quality grades were measured and recorded. Carcasses were fabricated into closely trimmed, boneless subprimals at 1.27- and .32-cm fat trim levels. Cutability percentage (percentage of retail cuts from the cold carcass weight) and kilograms of retail product were defined three ways. The first definition included only retail cuts from the round, loin, rib, and chuck. The second included the above plus adjusted lean trim from the round, loin, rib, and chuck, and, finally, total retail product from the entire carcass. Kilograms (TOTFAT) and percentage (PERFAT) of trimmable fat were also calculated. Stepwise regression procedures were used for live and carcass trait model development predicting cutability percentages, kilograms of retail product, and trimmable fat. Fat measurements accounted for the largest portion of variation in cutability percentage and PERFAT. Weight measurements accounted for the major sources of variation in predicting kilograms of retail product and TOTFAT. Final models using live animal traits ranked the steers equally as well for cutability percentages as the original USDA cutability equation and stepwise, developed carcass equations (P > .10). Final models using live animal or carcass equations ranked the animals equally for kilograms of retail product yield (P > .10).

Adipose Tissue↗
PubMed1994

Foodservice industry market profile study: nutritional and objective textural profile of foodservice ground beef.

Ground beef patties of three types (regular, lean, extra-lean) destined for the foodservice industry were collected from foodservice purveyors in 12 cities equally distributed across six geographical regions of the United States to assess nutritional and objective texture characteristics. Patties were cooked on a foodservice-style clamshell grill to a well (approximately 80 degrees C) degree of doneness (internal temperature) for nutritional analysis and objective texture measurements. Single 5.08-cm2 samples were removed from the center of each patty and sheared with a multiple-blade Allo-Kramer shearing device. Nutritional composition, including proximate analysis values and fatty acid profiles, was determined on both raw and cooked samples of the ground beef. Extra-lean ground beef contained the least (P < .05) fat (12.43%), lean had an intermediate level (17.45%), and regular ground beef contained the most fat (P < .05) (20.20%), on a raw basis. However, after cooking, fat content was similar (P > .05) for regular and lean ground beef. Fatty acid composition of lipid and cholesterol content of ground beef did not differ (P > .05) across types of ground beef or between raw and cooked samples and was similar to USDA Handbook 8-13 values. Cooking loss decreased (P < .05) as fat percentages decreased. Regular and lean ground beef was easier (P < .05) to shear (4.20 and 4.24 kg/g of sample, respectively) than extra-lean ground beef (5.08 kg/g of sample). On average, foodservice ground beef sampled in the present study is 15.5% leaner than retail ground beef as presented in the National Beef Market Basket Survey and 22.2% leaner than USDA Handbook 8-13 values.

Animals↗
PubMed1994

Effect of porcine somatotropin (pST) treatment and withdrawal on performance and adipose tissue cellularity in finishing swine.

A 10-wk trial was conducted with 60 barrows and 60 gilts (initial weight = 47 kg) to investigate the effect of pST treatment (3 mg/d) for wk 0 to 5, 5 to 10, or 0 to 10 on performance, carcass traits, and adipose tissue cellularity of finishing hogs. The primary objective of the study was to determine the effect of 5 wk of pST treatment followed by 5 wk of withdrawal on performance and carcass traits relative to a control or to pigs treated for the entire period. After 5 wk, pST-treated pigs exhibited improved (P < .001) gain (11%) and efficiency (22%) and decreased (P < .001) feed intake (-22%) and 10th rib backfat accretion (-93%, P < .001). There was an increase in adipose cell number/gram of tissue (control, 2.57 vs pST, 3.36 x 10(6)/g; P < .005) and a decrease in cell diameter (control, 72.4 vs pST, 67.2 microns; P < .005). Backfat thickness and cell diameter increased in control pigs from wk 5 to 10. During the last 5-wk period, pST-treated animals continued to exhibit improved performance and maintained adipose cell size distribution and number similar to the pST-treated pigs at wk 5. Pigs treated for the first 5 wk and withdrawn from treatment for the second 5 wk had decreased efficiency (-12%, P < .05) and a twofold increase in backfat accretion (P < .001) relative to control. The increase in backfat thickness was accompanied by an increase in adipocyte diameter, indicative of lipid filling. Most of the benefits of pST observed during the first 5 wk were lost during the withdrawal period. Reductions in carcass fat in response to pST treatment are at least partially accounted for by inhibition of lipid filling in adipose tissue, an effect that is reversed upon cessation of treatment.

Adipocytes↗
PubMed1993

Pressure-flow characteristics of intramural and total coronary collateral networks.

The purpose of the present investigation was to determine the pressure-flow (PF) relationship of intramural collaterals and to determine whether their characteristics differ significantly from those of the total collateral network, defined as the epicardial plus intramural collateral network. Because a significant portion of the collateral flow is diverted away from the retrograde flow measurement, we embolized the coronary vessel on which the retrograde flow was measured with spheres of various sizes until the retrograde flow was maximized and retrograde flow diversion blocked. The PF relationship was obtained before and after the epicardial collaterals were cauterized to determine the characteristics of the total and intramural collateral network. PF data for the collateral circulations were obtained by changing the inflow pressure to all coronary vessels simultaneously and by measuring the retrograde flow while maintaining the retrograde outflow pressure at 0 mmHg. The PF characteristics of the total and intramural collateral circulations could be fitted by either a second-degree polynomial or linear equation. In both cases the pressure intercept crossed the origin of the axes. The average contribution of intramural collaterals to total retrograde flow was 58 +/- 5%. We conclude that the PF characteristics of intramural collaterals parallel those of the total collateral circulation.

Animals↗
PubMed1993

Effect of pH and ionic strength on bovine m-calpain and calpastatin activity.

The effects of bovine skeletal muscle m-calpain and calpastatin on the degradation of casein and isolated bovine myofibrils were characterized under various pH values (7.0, 6.2, 5.7) and ionic strengths (32 to 400 mM KCl) at 25 degrees C. Caseinolytic assays indicated that m-calpain activity increased with increasing pH (P < .01) but decreased with increasing ionic strength (P < .01). Regardless of the presence of m-calpain, SDS-PAGE of myofibrils showed increased solubilization of myofibrillar proteins as pH and ionic strength increased. However, only in the presence of m-calpain were changes normally observed during postmortem storage reproduced. Protein release attributed to m-calpain activity increased with pH, but the effects of elevated ionic strength on the ability of m-calpain to hydrolyze myofibrillar proteins were not evident from SDS-PAGE, except for the decreased troponin-T degradation by m-calpain at the higher ionic strengths. A pH x ionic strength interaction was observed for calpastatin activity determined by caseinolytic assays (P < .01). No changes in m-calpain inhibition were detected at pH 7.0 and 6.2 at different ionic strengths. However, at pH 5.7 the ability of calpastatin to inhibit m-calpain decreased with increasing ionic strength. No changes in m-calpain inhibition could be detected with SDS-PAGE. Based on these results, it can be concluded that although m-calpain and calpastatin activities decrease with increasing ionic strength, their activities in the presence of myofibrils were not affected by ionic strengths typically found in postmortem muscle.

Animals↗
PubMed1993

Effect of prepubertal body weight gain and breed on carcass composition at puberty in beef heifers.

Fourteen prepubertal Angus heifers, all of which reached puberty, and 11 Santa Gertrudis (SG) heifers, eight of which reached puberty, were divided into two treatment groups. There was no breed difference in age at puberty for those that reached puberty. Treatment 1 (T1) heifers, fed to gain .5 kg/d, tended (P < .11) to be older than Treatment 2 (T2) heifers, fed to gain 1 kg/d, at puberty. Body weight and height were greater (P < .01) in SG than in Angus heifers at puberty. Angus heifers in T2 deposited more fat over the rump during the 15 wk before puberty, whereas T1 SG heifers deposited the least amount of fat (P < .05). Heifers in T2 were heavier at puberty (P < .05), had faster growing longissimus muscle areas (P < .05), and deposited more fat over the rib (P < .01) as they approached puberty. The T2 (P < .05) and Angus (P < .05) rib sections had more dissectible subcutaneous fat than did T1 and SG rib sections. Angus heifers had higher marbling scores (P < .05), as well as higher total lipid percentages for seam fat (P < .05), longissimus muscle (P < .01), other lean tissue (P < .05), and subcutaneous fat (P < .01). Predicted total lipid content for the edible portion of the dressed carcass was higher for T2 heifers (P < .09).

Adipose Tissue↗
PubMed1993

Foodservice industry market profile study: in-plant beef fat trim level survey and cutting yields.

Fifty foodservice purveying companies were sampled in 12 U.S. cities evenly distributed across six geographical regions. Beef whole muscle cuts (WMC) and portion control items (PCI) from the primal rib and loin were evaluated for surface fat levels. Fat thicknesses were measured on WMC before and after fabrication, whereas additional PCI were measured for fat trim levels before distribution. The average initial fat thickness was 11.9 mm (174 Short Loin and 180A Strip Loin) and 15.6 mm (184 Top Sirloin Butt); maximum fat thicknesses ranged from 16.2 mm (strip loin) to 22.2 mm (top sirloin butt). After fabrication, average fat thicknesses were 6.2, 5.1, and 4.0 mm for resulting products from the short loin, strip loin, and top sirloin butt, respectively. The average initial fat thickness for the strip loin was greater (P < .05) in Southeast and Northeast regions than in Mountain/Desert, Midwest, and Southwest regions. In contrast, average trimmed fat thicknesses for products from the strip loin and top sirloin butt were lower (P < .05) in the Southeast and Northeast than in all other regions. Average fat trim levels for PCI were 3.0 (1112A Ribeye Roll steak, Lip-On), 5.3 (1173B/1174B T-Bone/Porterhouse steak), 5.0 (1180A Strip Loin steak), and 4.0 mm (1184B Top Sirloin steak). Maximum fat trim levels were 4.4 (IMPS 1112A), 7.4 (IMPS 1173B/1174B), 6.9 (IMPS 1180A), and 5.5 mm (IMPS 1184B). The PCI had average and maximum fat trim levels in compliance with USDA (1988) recommendations for fat trim specifications.(ABSTRACT TRUNCATED AT 250 WORDS)

Adipose Tissue↗
PubMed1993

The impact of aphasia on marital satisfaction.

This investigation retrospectively examined changes in marital satisfaction following stroke. The relationship between such changes and other pertinent factors were also examined, including severity of aphasia, knowledge of aphasia, number of months after stroke, and length of the marriage. The subjects were 40 spouses of patients with aphasia grouped according to severity of the aphasia (mild, moderate, severe). Spouses completed two different measures of marital satisfaction--the Marital Satisfaction Scale (MSS) and the Marital Comparison Level Index (MCLI). These measures were completed in both a prestroke (retrospective reporting) and a poststroke format to allow for change to be assessed. In addition, a Knowledge of Aphasia questionnaire was completed by the normal spouses to evaluate their understanding of the disorder of aphasia. There was a significant difference between prestroke and poststroke scores on both the MSS and the MCLI, indicating a lower level of satisfaction following the stroke. The amount of change between prestroke and poststroke MSS and MCLI scores was not related to either number of months poststroke or number of years married. Although there was no relationship between changes in prestroke and poststroke scores on the MCLI and Knowledge of Aphasia scores, there was a significant correlation between changes in these scores on the MSS and Knowledge of Aphasia scores. Hence, the more knowledge spouses had regarding aphasia, the less the negative impact the stroke had on marital satisfaction, as measured by the MSS. Results are discussed in terms of the interdisciplinary treatment needs of aphasic patients and the implications for future investigations.

Aged↗
PubMed1992

The low density lipoprotein receptor-related protein/alpha 2-macroglobulin receptor binds and mediates catabolism of bovine milk lipoprotein lipase.

Lipoprotein lipase (LPL), the major lipolytic enzyme involved in the conversion of triglyceride-rich lipoproteins to remnants, was found to compete with binding of activated alpha 2-macroglobulin (alpha 2M*) to the low density lipoprotein receptor-related protein (LRP)/alpha 2-macroglobulin receptor. Bovine milk LPL displaced both 125I-labeled alpha 2M* and 39-kDa alpha 2M receptor-associated protein (RAP) from the surface of cultured mutant fibroblasts lacking LDL receptors with apparent KI values at 4 degrees C of 6.8 and 30 nM, respectively. Furthermore, LPL inhibited the cellular degradation of 125I-alpha 2M* at 37 degrees C. Because both alpha 2M* and RAP interact with LRP, these data suggest that LPL binds specifically to this receptor. This was further supported by observing that an immunoaffinity-isolated polyclonal antibody against LRP blocked cellular degradation of 125I-LPL in a dose-dependent manner. In addition, 125I-LPL bound to highly purified LRP in a solid-phase assay with a KD of 18 nM, and this binding could be partially displaced with alpha 2M* (KI = 7 nM) and RAP (KI = 3 nM). Taken together, these data establish that LPL binds with high affinity to LRP and undergoes LRP-mediated cellular uptake. The implication of these findings for lipoprotein catabolism in vivo may be important if LRP binding is preserved when LPL is attached to lipoproteins. If so, LPL might facilitate LRP-mediated clearance of lipoproteins.

Animals↗
PubMed1992

3-Carboxy-cis,cis-muconate lactonizing enzyme from Pseudomonas putida is homologous to the class II fumarase family: a new reaction in the evolution of a mechanistic motif.

The gene (pcaB) for 3-carboxymuconate lactonizing enzyme (CMLE; 3-carboxymuconate cycloisomerase; EC 5.5.1.2) from Pseudomonas putida has been cloned into pMG27NS, a temperature-sensitive expression vector, and expressed in Escherichia coli N4830. The specific activity and kinetic parameters of the recombinant CMLE were comparable to those previously reported. A comparison of the deduced amino acid sequence of CMLE with sequences available in the PIR and Genbank databases revealed that CMLE has highly significant sequence homology to the class II fumarase family, particularly to adenylosuccinate lyase from Bacillus subtilis. CMLE has no significant homology to muconate lactonizing enzyme (MLE) from P. putida, its sister enzyme in the beta-ketoadipate pathway. These findings fully corroborate a prediction made by us on the basis of mechanistic and stereochemical analyses of CMLE and MLE [Chari, R. V. J., Whitman, C. P., Kozarich, J. W., Ngai, K.-L., & Ornston, L. N. (1987) J. Am. Chem. Soc. 109, 5514-5519] and suggest that CMLE and MLE were recruited into this specialized pathway from two different enzyme families.

Amino Acid Sequence↗
PubMed1992

Carnivorous plants: phylogeny and structural evolution.

The carnivorous habit in flowering plants represents a grade of structural organization. Different morphological features associated with the attraction, trapping, and digestion of prey characterize a diversity of specialized forms, including the familiar pitcher and flypaper traps. Phylogenetic analysis of nucleotide sequence data from the plastic rbcL gene indicates that both carnivory and stereotyped trap forms have arisen independently in different lineages of angiosperms. Furthermore, these results demonstrate that flypaper traps share close common ancestry with all other trap forms. Recognition of these patterns of diversification may provide ideal, naturally occurring systems for studies of developmental processes underlying macromorphological evolution in angiosperms.

Base Sequence↗
PubMed1992

A novel mechanism for controlling the activity of alpha 2-macroglobulin receptor/low density lipoprotein receptor-related protein. Multiple regulatory sites for 39-kDa receptor-associated protein.

The alpha 2-macroglobulin receptor/low density lipoprotein receptor-related protein (alpha 2MR/LRP) consists of two polypeptides, 515 and 85 kDa, that are noncovalently associated. A 39-kDa polypeptide, termed the receptor-associated protein (RAP), interacts with the 515-kDa subunit after biosynthesis of these molecules and remains associated on the cell surface. This molecule regulates ligand binding of alpha 2MR/LRP (Herz, J., Goldstein, J. L., Strickland, D. K., Ho, Y. K., and Brown, M. S. (1991) J. Biol. Chem. 266, 21232-21238). Titration and binding studies indicate that RAP binds to two equivalent binding sites on alpha 2MR/LRP, with a KD of 14 nM. Heterologous ligand displacement experiments demonstrated that RAP completely inhibits the binding of 125I-activated alpha 2M to human fibroblasts and to the purified alpha 2MR/LRP, with a Ki of 23 and 26 nM, respectively. A direct correlation between the degree of binding of RAP to the receptor and the degree of ligand inhibition was observed, indicating that as the RAP binding sites are saturated, alpha 2MR/LRP loses its ability to bind ligands. Thus, the amount of RAP bound to alpha 2MR/LRP dictates the level of receptor activity. A model is proposed in which alpha 2MR/LRP contains multiple ligand binding sites, each regulated by a separate RAP site.

Base Sequence↗
PubMed1992

Effect of hot-fat trimming on factors associated with the subprimal yield of beef carcasses.

Thirty-two crossbred cattle (steers = 17; heifers = 15) exhibiting an ultrasound fat thickness at the 12 to 13th rib region of at least 10 mm were selected from a slaughter shift at a commercial packing plant. After splitting, alternating sides of each carcass were trimmed of 1) subcutaneous fat in excess of 6.4 mm; 2) all kidney, pelvic, and heart fat; and 3) all cod or udder fat and fat in the flank region. Both sides of each carcass were fabricated into subprimals (final trim level of 6.4 mm) according to normal industry procedures. Effect of hot-fat trimming, yield grade (3, 4, and 5), and gender on hot-fat trim, fabrication fat trim, major subprimal, and total subprimal yield of untrimmed and trimmed carcasses were determined. Higher numerical yield grade (YG) corresponded with higher (P less than .05) percentages of hot-fat trim. Hot-fat trimming increased (P less than .05) the difference in fabrication fat trim between steers and heifers and between YG 3 and YG 5. Steers and heifers differed (P less than .05) in percentage of major subprimals and total subprimals when processed conventionally, whereas hot-fat trimming eliminated this difference (P less than .05). Untrimmed YG 3 carcasses had 3.1 and 5.0% higher major subprimal yield (P less than .05) than untrimmed YG 4 and YG 5 carcasses, respectively, whereas hot-fat trimming reduced this difference to 2.5% for YG 4 and to 3.7% for YG 5.(ABSTRACT TRUNCATED AT 250 WORDS)

Adipose Tissue↗
PubMed1991

An investigation of naming errors following semantic and phonemic cueing.

This study investigated the types of verbal errors produced by aphasic patients following phonemic and semantic cueing. Twenty-eight aphasic patients--10 Broca's, 10 Wernicke's and 8 conduction aphasics--served as subjects. Semantic and phonemic cues were administered on object and action confrontation-naming tasks. When subjects did not respond correctly to phonemic cueing, a significantly greater number of phonemic errors were produced, with a concurrent decline in related words and extended circumlocutions. When subjects failed to respond to semantic cueing on the action task, there was an increase in a number of error categories.

Anomia↗
PubMed1991

Kinetochore analysis of micronuclei allows insights into the actions of colcemid and mitomycin C.

We have induced micronuclei in two strains of diploid human fibroblasts with a known aneugen, colcemid, and a known clastogen, mitomycin C. Using immunofluorescence to detect the presence of kinetochores in micronuclei, we were able to demonstrate a 26.8-fold increase in fluorescence-positive micronuclei (aneuploidy) in colcemid-treated cells. However, colcemid also induced an increase in kinetochore-negative micronuclei. Our findings support previous reports that suggest colcemid may induce chromosome breakage in addition to its major aneugenic effect. The frequency of kinetochore-negative micronuclei (chromosome breakage) in mitomycin C-treated cells rose an average of 7.9-fold in the two test strains, a clear reflection of its clastogenic action. However, a 4-fold increase in the kinetochore-positive fraction was seen. We conclude that the fibroblast micronucleus assay, coupled with kinetochore immunofluorescence, provides a useful screening approach for genotoxic agents. The delineation of the precise mechanism by which an agent perturbs the rates of chromosomal breakage or lag may require more detailed analysis.

Aneuploidy↗