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R L West

Publications and source records attributed to R L West.

At least 19 recordsLinked to original sources
PubMed1992

Sequence and methylation in the beta/A4 region of the rabbit amyloid precursor protein gene.

Alzheimer's disease is characterized by the accumulation of the beta/A4 fragment of the amyloid precursor protein in the hippocampal regions of the brain. We report here the isolation of genomic clones carrying exons 15, 16 and 17 of the beta/A4 coding region of the rabbit amyloid precursor protein gene. The complete sequence of these exons predicts that all three peptides are identical to their human counterparts. An unexpectedly high concentration of CpG dinucleotides seen in exon 15 were conserved and continued into the intron 15 region. MspI/HpaII southern blot analysis revealed the presence of a number of methylated CpG dinucleotides in the cloned region of the gene. These data suggest that the rabbit amyloid precursor protein gene could provide a new and useful model for the study of this important gene.

Amino Acid Sequence↗
PubMed1992

Everyday memory performance across the life span: effects of age and noncognitive individual differences.

Gerontologists have long been concerned with the impact of individual-difference factors on memory. This study used a large sample (N = 2,495) of adult volunteers aged 18 to 90 years to determine if a set of individual-difference variables--vocabulary, education, depression, gender, marital status, and employment status--mediates the effects of aging on a wide range of laboratory-analogue tests of everyday memory. The data indicated that age was consistently the most significant predictor of memory performance, followed by vocabulary and gender. Vocabulary totally mediated age effects on a prose memory measure, and partial mediation of aging effects--primarily by vocabulary and gender--was observed on 5 other memory tests. These data suggest that when health samples of volunteers serve as research subjects, these individual differences can affect some memory test scores, but age remains the best overall predictor of memory performance.

Adolescent↗
PubMed1991

Age differences in the recall of actions and cognitive activities: the effects of presentation rate and object cues.

In studies of activity memory, age differences have been found in the recall of cognitive activities (sustained mental activities that subjects solve during acquisition) but not in recall of Subject-Performed Tasks (one-step actions that subjects enact during acquisition). To understand the reasons for the discrepant findings, both types of item were included in a study examining the effects of object cues, rate of presentation, and aging. Variations in presentation rate or use of objects did not account for the different findings on the two item types. Even when presentation rate and object cues were matched, larger age differences were found for recall of cognitive activities than of SPTs. Age differences were also affected by the interaction of item type, presentation rate, and the presence of objects during encoding. To identify the variables controlling age differences, more analysis is needed of the features of activities to be remembered.

Adolescent↗
PubMed1991

The association of memory complaint with computer-simulated everyday memory performance.

The relationship of memory self-report to self-rated depression and to actual performance on computer-simulated everyday memory tasks was investigated in 125 normal adults. Canonical correlation analyses demonstrated that self-rated memory performance and objective computer-simulated everyday memory performance shared from 27.9% to 29.4% of common variance. These data provide initial concurrent validity for a new memory self-report scale, the MAC-S. Results are discussed in relation to psychometric factors important in the design and validation of self-report memory scales.

Adolescent↗
PubMed1991

Factors influencing intermuscular fat and other measures of beef chuck composition.

Carcasses from 59 steers produced from the mating of Braford, Simbrah, Senepol, and Simmental bulls to Brahman- and Romana Red-sired cows and Brahman bulls mated to Angus cows were used in this study. Effects of sire breed and feeding calves vs yearlings on fat depots in the chuck, when steers were fed to 1.0 cm external fat, were determined. Breed of sire and feeding calves vs yearlings had no effect (P greater than .05) on percentage of intermuscular fat. However, carcasses from Braford-sired steers had a higher (P less than .05) percentage of dissectable subcutaneous fat on the chuck than did those from other breed groups. Carcasses from Simmental-sired steers were superior (P less than .05) to those from Braford-sired steers in USDA yield grade and had a higher average marbling score (P less than .05) than the Simbrah-sired group. Estimated kidney, pelvic, and heart (KPH) fat was higher (P less than .05) in carcasses from Brahman-, Simbrah-, and Senepol-sired steers than in Braford-sired steers. Steers fed as calves had higher percentages (P less than .05) of KPH fat and major chuck muscles than did those fed as yearlings. The best single predictor of percentage of intermuscular fat within the chuck was adjusted fat over the ribeye (R2 = .46).

Adipose Tissue↗
PubMed1991

The effect of breed of sire and age at feeding on muscle tenderness in the beef chuck.

Steers (n = 59) produced from the mating of Braford, Simbrah, Senepol, and Simmental bulls to Brahman- and Romana Red-sired cows and Brahman bulls to Angus cows were used in this study. Effects of sire breed and age at feeding on muscle tenderness in the major muscles of the chuck when steers were fed to 1.0 cm 12th rib fat were determined. There were no muscle tenderness effects due to sire breed group, with the exception of the serratus ventralis muscle, which was more tender in Brahman- and Braford-sired steers than in Simmental-sired steers. Additionally, the supraspinatus muscle from the yearlings was lower in shear value than that from the calves. The Brahman-sired steers had serratus ventralis muscles with higher percentages (P less than .05) of intramuscular fat than those of Braford-, Simbrah-, and Simmental-sired steers. Fat deposited within the muscle or between muscles in the chuck was not related to muscle tenderness as measured by Warner-Bratzler shear values. Also, percentages of intramuscular fat of the triceps brachii, serratus ventralis, or supraspinatus muscles were not influenced (P greater than .05) by age at feeding.

Adipose Tissue↗
PubMed1990

Age differences in everyday memory: laboratory analogues of telephone number recall.

Three experiments were conducted to examine age differences in memory for telephone numbers by adults ranging from 18 to 85 years of age. In the first 2 studies, using visual simultaneous presentation, age declines in immediate recall were evident on 10-digit numbers, but not on 3-digit numbers. With 7-digit numbers, the youngest group performed significantly better than the oldest (70-85 years) group. In the second study, more marked age declines occurred when subjects had to redial a number after a busy signal. The third experiment replicated the observed aging pattern with auditory sequential presentation. Also, chunked presentation of local telephone numbers resulted in high performance for old and young in sequential recall. The findings were discussed in relation to task processing demands and practical issues related to telephone number recall.

Adolescent↗
PubMed1990

Name recall performance across the adult life-span.

Everyday name-recall tests were administered to 1205 adults ranging in age from 18 to 90 years. They were asked to recall sets of four, six, or 14 names of individuals who introduced themselves on videotape. Immediate recall, acquisition, and delayed retention were examined. The results showed consistent age-related declines in name recall. Declines in performance were more evident on sets of 14 names rather than four or six names. Age deficits remained across several acquisition trials within the set of 14 names. The largest declines were evident for the old-old (over 70), although there were also significant performance differences, on some analyses, between the young and middle-aged groups. Changes in performance were less apparent during the middle-aged years (40-60 years). Name recall was related to individual differences factors, reaction time and paired-associate memory for names. The value of assessment and intervention with name recall was stressed.

Adult↗
PubMed1989

Bronchoalveolar lavage in the diagnosis of lipoid pneumonia.

Lipoid pneumonia (LP) is an uncommon entity with the characteristic radiographic features and histologic findings of alveoli filled with vacuolated, lipid-laden histiocytes. We questioned whether bronchoalveolar lavage (BAL) could be useful in the confirmation of LP. We examined lipid stains (oil-red O) in BAL specimens from 18 cases, representing a variety of pulmonary disease states, and compared them with an index case of confirmed LP. The index case of LP had a history of chronic intranasal use of mentholated petrolatum with subsequent x-ray findings of progressive air bronchograms. Positive histochemical confirmation (oil-red O) performed on frozen sections of transbronchial lung biopsy was obtained. Eleven of the non-LP cases had no intracellular staining of BAL macrophages with oil-red O stain, whereas the index case of LP exhibited markedly positive intracytoplasmic staining of macrophages for lipid. The remaining seven cases showed minimal to mild lipid staining with only one other case having moderate staining. This study demonstrates that BAL macrophages from patients with a variety of pulmonary states and without suspected LP do not demonstrate significant staining for intracellular lipids, in contrast with the expected strong positivity of LP. Lipid staining of BAL specimens, although not entirely specific, may be a preferred method for confirming the diagnosis of LP, thereby avoiding more invasive procedures.

Adult↗
PubMed1987

Carcass and meat quality characteristics and backfat fatty acid composition of swine as affected by the consumption of peanuts remaining in the field after harvest.

Carcass composition, meat quality characteristics and changes in backfat fatty acid composition of swine that were allowed to obtain part or all of their weight gain during the growing-finishing period from gleaning peanuts remaining in the field after harvest were evaluated. Thirty-six cross-bred pigs (18 barrows, 18 gilts) were allotted evenly among the following six treatments: 1) fed a corn-soybean meal-based diet (C) from 26 to 104 kg (CCC); 2) gleaned peanuts (P) from 26 to 102 kg (PPP); 3) C from 26 to 78 kg and P from 78 to 103 kg (CCP); 4) P from 26 to 55 kg and C from 55 to 105 kg (PCC); 5) C from 26 to 56 kg and P from 56 to 103 kg (CCP); 6) P from 26 to 79 kg and C from 79 to 106 kg (PPC). Carcasses from all treatment groups were similar in composition. Carcass fat of pigs in CPP, PPC and, in particular, PPP groups was softer than that from pigs in CCC, CCP and PCC groups. Ratio of unsaturated to saturated fatty acids in backfat increased in proportion to the amount of weight gained while pigs gleaned peanuts. Loins from pigs in the PPP and CPP treatment groups received lower marbling scores than those from the CCC group, but the fat content of the loin was not affected by treatment. No differences were detected between treatment groups in shear force values or sensory panel attributes of broiled loin chops, or in thiobarbituric acid values of vacuum packaged loin sections frozen for 4 mo.(ABSTRACT TRUNCATED AT 250 WORDS)

Adipose Tissue↗
PubMed1986

The role of fine-needle aspiration biopsy in the rapid diagnosis and management of thyroid neoplasm.

This report describes our 5-year experience with fine-needle aspiration (FNA) biopsy of the thyroid in a 560-bed teaching hospital. Three hundred nine FNA biopsies were performed primarily by one endocrinologist and interpreted by several pathologists. Analysis of the data reveals the sensitivity of the procedure is 93%, specificity is 95.1%, and the positive and negative predictive values are 88.9% and 96.5%, respectively. This data confirms the diagnostic accuracy of FNA biopsy. Complications were seen in 6 of 309 cases (1.9%) and were relatively mild. Nearly 75% of the cases in the series were cytologically diagnosed as nonneoplastic. Fine-needle aspiration biopsy identified 19.4% of the cases needing surgery, of which 72% had neoplastic nodules, confirming the selection role of the procedure. The management of thyroid nodules is discussed and a selective review of the FNA literature is presented. The authors believe that our experience rebuts the argument that special referral centers are needed to interpret the cytologic material. Several well trained surgical pathologists can become proficient in interpreting the FNA biopsies without significant loss in accuracy, and thereby render a definite diagnosis in the vast majority of the cases. Accordingly, the authors recommend FNA of the thyroid as the initial diagnostic test in the evaluation of thyroid nodules.

Adenocarcinoma↗