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Biomedical subjects

R Elliott

Publications and source records attributed to R Elliott.

At least 109 records · Page 6Linked to original sources
PubMed1995

Neuropsychological evidence for frontostriatal dysfunction in schizophrenia.

Schizophrenics and controls were compared on a computerized test of attentional set-shifting which provides a componential analysis of the Wisconsin Card Sort Test and has previously been shown to be sensitive to frontal lobe dysfunction and Parkinson's disease. The main test was of extra-dimensional shifting where subjects are required to shift response to an alternative perceptual dimension. In one condition, termed 'perseveration', subjects are required to shift to a novel dimension and ignore the previously relevant one. In the other condition, termed 'learned irrelevance', subjects are required to shift to the previously irrelevant dimension and ignore a novel one. Chronic medicated schizophrenics (N = 32) show a highly significant impairment on the perseveration but not the learned irrelevance condition, as compared to normal age and IQ matched controls (N = 24). This was true even of a subgroup of patients with preserved IQ. The impairments in attentional set-shifting failed to correlate with patients' scores on the Mini-Mental State Examination (mean; S.D. 26.8; 1.8) or with scores on a test of recognition memory. These results provide evidence for a specific deficit in a set-shifting test of executive function and support a hypothesis of frontostriatal dysfunction in schizophrenia.

Adult↗
PubMed1995

Control of coccidia in young calves using lasalocid.

Thirty-six, 2- to 4-day-old Friesian bull calves were divided into 4 groups and fed milk replacer and calf starter pellets ad libitum in separate pens. Four treatments were applied; lasalocid in milk (1 mg/kg body weight/day) (M), lasalocid in starter (F), lasalocid in both milk and starter (M + F) and untreated (C). When the calves were about 2 weeks old they were each dosed orally with 550,000 sporulated Eimeria sp oocysts, mainly E zurneii and E bovis. The infection, detected by faecal excretion of oocysts, was suppressed in the M + F and M groups. There was significant excretion of oocysts in the F group but these calves did not show any clinical signs of coccidiosis. Untreated calves were affected with diarrhoea containing blood on the 24th day after inoculation. Body weight gain and intake of starter pellets was also depressed in the untreated calves during the time they were clinically affected. It is concluded that mixing lasalocid in milk replacer (or fresh milk) is an effective method of protecting young calves against early infection with coccidia.

Animals↗
PubMed1995

Altered glucose dependence of glucagon-like peptide I(7-36)-induced insulin secretion from the Zucker (fa/fa) rat pancreas.

In previous studies on the enteroinsular axis in Zucker rats, it was found that glucose-dependent insulinotropic polypeptide (GIP) levels were normal in obese animals, but the glucose threshold for the insulinotropic action of GIP in the perfused rat pancreas was reduced. Glucagon-like peptide I (GLP-I)(7-36) is also an important incretin, and in the current study, glucose, insulin, and immunoreactive (IR)-COOH-terminal GLP-I responses to oral glucose were compared in lean (Fa/?) and obese (fa/fa) rats. In addition, the concentration thresholds for stimulation and glucose dependence of perfused pancreases to GLP-I(7-36) were examined. Glucose responses to oral glucose were similar in fa/fa and Fa/? rats. Obese animals were hyperinsulinemic when fasting and after oral glucose. Significant increases in IR-GLP-I levels in response to glucose were only observed in fa/fa rats. Perfused pancreases from fa/fa rats hypersecreted insulin at all glucose concentrations. In the presence of 4.4 mmol/l glucose, GLP-I(7-36) increased insulin secretion in fa/fa pancreases approximately 25-fold, whereas there was only a 5-fold increase in Fa/? pancreases. Pancreases from fa/fa rats, perfused with a glucose gradient (2.8-11 mmol/l) in the presence of GLP-I(7-36), responded with an immediate increase in insulin secretion, i.e., at a glucose concentration of 2.8 mmol/l, whereas Fa/? pancreases required a minimum of 4.22 mmol/l glucose for stimulation. With high glucose (16.7 mmol/l), both fa/fa and Fa/? rat pancreases exhibited similar responsiveness to GLP-I(7-36), having thresholds of < 50 pmol/l.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

Loss of heterozygosity in spontaneous and chemically induced tumors of the B6C3F1 mouse.

The B6C3F1 mouse is used worldwide to gauge the carcinogenic hazard posed by chemicals to humans. An assessment of the ability of this rodent model to predict human neoplasia requires an evaluation of similarities and differences in the genetics of tumor formation between these two species. We examined 142 spontaneous and chemically-induced liver tumors isolated from the B6C3F1 mouse for losses of heterozygosity (LOH) at 78 polymorphic loci and compared these results to genetic changes known to occur in human hepatocellular carcinoma. Approximately a third of the 142 mouse tumors exhibited LOH, suggesting that tumor suppressor gene inactivation may be involved in the formation of mouse liver tumors. Most of the LOH observed was restricted to seven chromosome sites and most of the tumors that underwent LOH lost alleles from only one of those seven sites. The relatively few losses seen in these mouse tumors distinguished them from clinical stage human tumors in that, in the mouse tumors, interstitial deletions appeared more frequently than losses of whole chromosomes. Only four mouse tumors lost a whole chromosome. LOH occurred at loci of the mouse genome syntenic to areas of the human genome known to harbor the Wilms', retinoblastoma, APC, MCC and DCC tumor suppressor genes; these genes have never been associated with hepatocellular carcinomas. Losses observed on chromosomes 5 and 8 (syntenic to human chromosomes 4 and 16) suggest tumor suppressor genes that are common to hepatocellular carcinomas from both species, while losses on chromosome 9 suggest involvement of a previously unidentified tumor suppressor gene.

Animals↗
PubMed1994

Emergency nurses' moral evaluation of patients.

Introduction Judgments by nurses concerning patients' moral fitness and the appropriateness of their visits to the emergency department are made constantly. The treatment rendered to patients is affected by these judgments. This study explored which patient characteristics emergency nurses used to morally evaluate patients, determined reasons the nurses gave for this behavior, and identified some factors that contributed to the evaluative behavior. Methods An exploratory, descriptive study with a mailed questionnaire was conducted on nurses working in emergency departments in hospitals throughout Alberta. Results Eighty-three questionnaires were completed and returned, representing a response rate of 55%. A hierarchy emerged from the data, validating previous research. Nature of the illness and diagnosis, in addition to certain patient characteristics, were critical in determining emergency nurses' attitudes. Nurses appeared to be unaware that they were acting prejudicially. Discussion When patients are aware of being disliked by the nurses caring for them, nurse-patient communication and relationship are jeopardized. This may affect care and, ultimately, recovery. Recommendations included encouraging nurses to recognize the dynamics, consequences, and inherent dangers of labeling patients and to improve their understanding of patients identified as unfavorable.

Alberta↗
PubMed1993

HTLV-II infection in Florida Indians.

A significantly increased prevalence of antibodies to human T-cell leukemia virus (HTLV) has been described in several native American populations in the United States and Latin America. Initial virologic studies indicate that HTLV-II is the predominant virus responsible for this antibody pattern. We obtained blood samples from 106 Seminole Indians living on four reservations in Southern Florida. Seropositivity to HTLV-I/II was found in 14 (13.2%) of these individuals. Polymerase chain reaction (PCR) documented HTLV-II and the absence of HTLV-I in 7 of the 9 donors available for follow-up testing of white blood cells. Evaluation of various risk factors excluded blood transfusion or intravenous drug use as an important contributing factor to the HTLV-II seroprevalence rate. These studies support the hypothesis that HTLV-II is endemic in many native American tribes in the Western hemisphere.

Florida↗
PubMed1992

"If you love someone, you don't hurt them": a comprehensive process analysis of a weeping event in therapy.

Early theorists described physical diseases (e.g., asthma, ulcers) thought to be associated with the inhibition of weeping (e.g., Alexander 1950), and catharsis theories (Breuer and Freud 1895/1955; Koestler 1964) postulated that unexpressed emotion accumulated as in a tank, and then overflowed as tears when a threshold level was exceeded. From a more biological perspective, it has been suggested that stress produces toxic chemicals in the body that become concentrated in the lacrimal gland and are released through weeping, restoring homeostasis (Frey 1985). As a result of these theories, psychotherapists tend to believe weeping is healthy for clients and that it serves to decrease depression (Trezza et al. 1988). While laboratory studies have typically not supported these ideas (e.g., Labott and Martin 1987, 1988), no studies have been performed on weeping specifically in the context of psychotherapy.

Adult↗
PubMed1992

Reporting what you have seen: effects associated with age and mode of questioning on eyewitness reports.

This study examined age-related differences in the reporting of a filmed domestic scene, in which a mother was either ambiguously caring or ambiguously abusive toward her daughter. Three age groups were used (3- to 4-yr.-old, 6- to 7-yr.-old, and adult), and three modes of questioning were used (free recall, short-answer cued-recall, and leading questions either consistent or inconsistent with what was observed). There were 119 subjects in all: 39 3- to 4-yr.-olds, 39 6- to 7-yr.-olds, and 41 adults. Developmental trends were found in the subjects' ability to answer free-recall questions and cued-recall questions. Although 6- to 7-yr.-olds were significantly lower than adults in their accuracy scores on the cued-recall questions, they were still highly accurate. There were also significant age-related differences in the subjects' suggestibility, with the 3- to 4-yr.-olds being relatively suggestible, the 6- to 7-yr.-olds less so, and the adults virtually unsuggestible. When the leading questions that concerned the central theme of the film (i.e., Was the mother abusive or not?) were isolated, however, no significant age-related differences in suggestibility were found.

Adolescent↗
PubMed1991

Transcription analysis and sequence of the putative murine cytomegalovirus DNA polymerase gene.

The conservation of the herpesvirus DNA polymerases has allowed cross-hybridization studies to be used for their identification and mapping on the viral genome. With the use of a DNA fragment containing the DNA polymerase gene of human cytomegalovirus (HCMV) as a hybridization probe, we were able to localize the DNA polymerase gene of murine cytomegalovirus (MCMV) to a region within MCMV EcoRI fragment B which spans the HindIII site separating HindIII fragments D and H. This site is colinear with the HCMV strain AD169 DNA polymerase gene. To confirm that this region encoded the MCMV DNA polymerase gene, we sequenced a 5131 nucleotide fragment from the PstI site in HindIII fragment D to a BglII site in HindIII fragment H. Initiating in HindIII fragment D and extending into HindIII fragment H was a long open reading frame (ORF) 1097 amino acids in length with extensive homology to the DNA polymerases of HCMV, herpes simplex virus, and Epstein-Barr virus. Upstream of the polymerase ORF was a reading frame with considerable homology to the carboxy terminal half of the glycoprotein B gene of human herpesviruses. At early times in the infection, we could detect with a probe representing part of the polymerase ORF two 3' coterminal transcripts, 3.9 kb and 1.7 kb in length. S1 nuclease and exonuclease VII analyses indicated that both transcripts were unspliced and initiated at independent sites in HindIII fragment D. By primer extension, we were able to map precisely the 5' end of the 3.9-kb RNA to a site 186 nucleotides upstream of the beginning of the DNA polymerase ORF.

Amino Acid Sequence↗
PubMed1991

Regulation of NGF gene expression in CNS glia by cell-cell contact.

Nerve growth factor (NGF) gene expression in central nervous system (CNS) glia appears to be associated with active glial growth. To study the underlying molecular mechanisms, we examined the effects of a number of growth-related factors on NGF mRNA expression in glial cultures. Our results suggest that glial membrane interaction, as a consequence of growth, actively inhibits NGF gene expression in CNS glia.

Animals↗
PubMed1991

Utilization of ileal digestible amino acids by growing pigs: threonine.

An experiment was conducted to determine the utilization of ileal digestible threonine by growing pigs. Three threonine-deficient diets (0.22 g ileal digestible threonine/MJ digestible energy (DE] were formulated using cottonseed meal, meat-and-bone meal and soya-bean meal respectively, as the only source of threonine in the diet. An additional three diets were formulated with supplements of threonine to confirm that threonine was limiting in the first three diets. The growth performance and retention of threonine by pigs given the six diets over the 20-45 kg growth phase was then determined. Growth rates (g/d) of the pigs given the three diets formulated to 0.22 g ileal digestible threonine/MJ DE were significantly different (P less than 0.001): cottonseed meal 417, meat-and-bone meal 452, soya-bean meal 524 (SED 13.6). The response of pigs to the addition of threonine confirmed that threonine was limiting in these diets. Crude protein (nitrogen x 6.25) deposited by the pigs (g/d) was significantly higher (P less than 0.001) for those given soya-bean meal (75), relative to meat-and-bone meal (62) and cottonseed meal (47) (SED 3.3). The proportion of ileal digestible threonine retained by pigs given the three protein concentrates was: cottonseed meal 0.44, meat-and-bone meal 0.59, soya-bean meal 0.64 (SED 0.024). These results indicate that values for the ileal digestibility of threonine in protein concentrates are unsuitable in dietary formulations as the assay does not reflect the proportion of threonine that can be utilized by the pig. It appears that, with heat-processed meals, a considerable proportion of the threonine is absorbed in a form(s) that is (are) inefficiently utilized.

Amino Acids↗
PubMed1991

A state-university collaboration program: residents' perspectives.

Little information is currently available about how residents perceive the recently developed state-university collaboration programs in psychiatry. To determine the opinions of residents participating in the collaboration program in Kentucky, the authors administered a questionnaire to 18 residents who had completed at least one rotation at Eastern State Hospital in Lexington. The questionnaire asked the residents to respond to statements about the clinical, organizational, and educational aspects of the experience. Most respondents rated the experience as favorable, and 78 percent indicated interest in state employment. In addition, the state hospital was noted as one of residents' three future career choices.

Academic Medical Centers↗
PubMed1990

floricaula: a homeotic gene required for flower development in antirrhinum majus.

Plants carrying the floricaula (flo) mutation cannot make the transition from inflorescence to floral meristems and have indeterminate shoots in place of flowers. The flo-613 allele carries a Tam3 transposon insertion, which allowed the isolation of the flo locus. The flo gene encodes a putative protein (FLO) containing a proline-rich N-terminus and a highly acidic region. In situ hybridization shows that the flo gene is transiently expressed in the very early stages of flower development. The earliest expression seen is in bract primordia, followed by sepal, petal, and carpel primordia, but no expression is detected in stamen primordia. This pattern of expression has implications for how flo affects phyllotaxis, organ identity, and determinacy. We propose that flo interacts in a sequential manner with other homeotic genes affecting floral organ identity.

Amino Acid Sequence↗
PubMed1990

Utilization of ileal digestible amino acids by pigs: lysine.

Two experiments were conducted to determine the utilization of ileal digestible lysine by pigs. In the first, the apparent ileal digestibility of amino acids in cottonseed meal, meat-and-bone meal and soya-bean meal was determined in pigs fitted with 'T'-shaped cannulas. In the second experiment, three lysine-deficient diets were formulated to 0.36 g ileal digestible lysine/MJ digestible energy (DE), with lysine contributed from the three protein concentrates as the only source of lysine in sugar-based diets. An additional three diets were formulated with supplements of lysine to verify that lysine was limiting in the first three diets. The growth performance and retention of lysine by pigs given the six diets over the 20-45 kg growth phase were then determined. The apparent ileal digestibility of lysine in the three protein concentrates (proportion of total) was: cottonseed meal 0.74, meat-and-bone meal 0.78, soya-bean meal 0.89. Growth rates (g/d) of the pigs given the three diets formulated to 0.36 g ileal digestible lysine/MJ DE were significantly different (P less than 0.001): cottonseed meal 377, meat-and-bone meal 492, soya-bean meal 541. The response of pigs to the addition of lysine confirmed that lysine was limiting in these diets. Crude protein (nitrogen x 6.25) deposited by the pigs was significantly higher (P less than 0.001) for those given soya-bean meal (77 g/d), relative to meat-and-bone meal (66 g/d) and cottonseed meal (38 g/d). The proportion of ileal digestible lysine retained by pigs given the three protein concentrates was: cottonseed meal 0.36, meat-and-bone meal 0.60, soya-bean meal 0.75. The results indicate that values for the ileal digestibility of lysine in protein concentrates are unsuitable in dietary formulations as the assay does not reflect the proportion of lysine that can be utilized by the pig. It appears that, with heat-processed meals, a considerable proportion of the lysine is absorbed in a form(s) that is (are) inefficiently utilized.

Animal Feed↗
PubMed1990

More on the discredibility of eyewitnesses.

This study examined the hypothesis that the extent to which discreditations of eyewitness testimony are effective is in part a function of the strength of the basic physical and noneyewitness circumstantial evidence to which eyewitness testimony adds. Specific guilt-inducing facts were varied within each of two case contexts. In these and other designs, both within- and between-subjects, the hypothesis was supported, though the main result was that it is not difficult to discredit eyewitness testimony. The rival hypothesis that the outcome is an artifact of ceiling effects cannot be rejected for these data.

Adult↗