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Biomedical subjects

D Guthrie

Publications and source records attributed to D Guthrie.

At least 91 records · Page 5Linked to original sources
PubMed1990

Symptom beliefs and actual blood glucose in type II diabetes.

The relationships of blood glucose levels to symptoms and symptom beliefs were examined in this study of persons (N = 51) with Type II diabetes. Analyses revealed that 88% of the subjects had at least one symptom that was substantially correlated with blood glucose levels. However, subjects' symptom beliefs (symptoms subjects believe are the best indicators of high or low blood glucose levels) were largely unrelated to actual blood glucose levels. Thus, subjects were often mistaken about which of their symptoms were accurate indicators of blood glucose levels. Analyses also showed that the accuracy of symptom beliefs for low blood glucose was positively related to metabolic control.

Adult↗
PubMed1990

Effects of hap mutations on heme and cytochrome formation in yeast.

Simultaneous effects of mutations in the transcriptional regulatory genes, HAP1, HAP2 and HAP3, on all respiratory cytochromes of Saccharomyces cerevisiae were determined. Cytochrome behavior in hap mutants and in cyc4 and rhm1 mutants, altered in regulation of 5-aminolevulinate synthase, was compared. Although hap mutants were isolated as trans-acting, transcriptional regulators of the CYC1 (iso-1-cytochrome c) gene, each mutant exhibits partial deficiencies in all cytochrome types. In hap2 and hap3 strains all cytochromes were decreased proportionally to about 40-50% of wild type values. In contrast, hap1 caused a decrease in all cytochromes and an accumulation of a pigment, probably Zn porphyrin. Apparently apocytochrome and heme biosynthesis retain coordination in hap2 and hap3, but not in hap1, mutants. Unlike cyc4 and rhm1 mutants, hap mutants do not exhibit 5-aminolevulinate-dependent restoration of cytochromes. The hap1 mutant grew at near-normal rates on glycerol, whereas hap2 and hap3 mutants grew very slowly. The frequency of [rho-] was high (16-18%) in hap2 and hap3 strains. Results are consistent with generalized control of mitochondrial replication directed by the HAP1-HAP2 system and heme-directed control of formation of all apocytochromes mediated by HAP1. Neither system exerts all-or-nothing control.

5-Aminolevulinate Synthetase↗
PubMed1990

Maturation of startle facilitation by sustained prestimulation.

The startle response to a 104dB (SPL) 50-ms burst of white noise was facilitated by prestimulation with a nonstartling tone sustained for 2 s prior to the startling stimulus in 3, 4, 5, and 8 year old children and young adults. Both startle amplitude and onset latency showed significantly greater facilitation in the preschool children than in the 8-year-olds and adults. The results of this experiment, which used a fixed prestimulation interval, were compared to those of an earlier study in which the prestimulation interval was varied. The maturational changes in startle facilitation in response to the 2-s prestimulation interval were similar in the two experiments. Hence the maturational effect on startle facilitation was independent of the uncertainty (as to when the startling stimulus would be given), which might be associated with variable prestimulation intervals. These findings suggest that the neuronal mechanisms that mediate startle facilitation undergo development during early childhood and mature about 8 years of age, and that this maturational sequence is relatively independent of attentional effects.

Acoustic Stimulation↗
PubMed1990

Intergroup and intrasubject principal component analysis of event-related potentials.

The purpose of this paper is to show that the familiar principal component analysis (PCA) of event-related potentials is identical to an easily formulated least squares method. This correspondence permits interpretation of several criticisms of PCA and clearer presentation of its strengths and shortcomings. Because data analysis based on PCA compares amplitudes of empirically derived components, it is necessary that the shape of the components be similar under the experimental conditions. We present and illustrate a statistical method for comparison of principal components across groups and between conditions within subjects.

Acoustic Stimulation↗
PubMed1990

Monitoring ovarian cancer using urine cyclic GMP. A two-centre study.

The usefulness of urine cyclic guanosine 3'-5'monophosphate (GMP (cGMP) as a cancer marker in ovarian cancer has been studied in two independent centres using specimens from 81 women. Serial specimens from 60 patients were monitored up to 2 years after the start of chemotherapy. Urine cGMP levels were significantly higher in those patients with poorly differentiated tumours. Levels were not associated with the tumour stage, histological type or residual tumour remaining after surgery. Pretreatment levels were of no value for predicting response to therapy or patient survival. During therapy, however, levels did confirm clinical observations and if a level was elevated then there was a 80-90% chance that the patient was not responding to therapy. Using serial measurements, it was possible to predict the recurrence of tumour in 16/25 patients prior to any other clinical signs.

Biomarkers, Tumor↗
PubMed1989

The effects of gepirone and 1-(2-pyrimidinyl)-piperazine on levels of corticosterone in rat plasma.

It was found that gepirone and 1-(2-pyrimidinyl)-piperazine (1-PP) increased levels of corticosterone in plasma in the intact rat. Gepirone was more potent and more efficacious than its metabolite, 1-PP. The ED50 was 6.4 mumol/kg for gepirone and 65.4 mumol/kg for 1-PP. Forty-five min after intraperitoneal administration, gepirone and 1-PP produced maximum increases in corticosterone of 283% and 211%, respectively, above control values. The amplitude and duration of the effects of the drugs were dependent on the ongoing activity in the hypothalamic-pituitary-adrenal axis. Consequently, the greatest absolute increases in corticosterone were produced during the afternoon when the activity in the hypothalamic-pituitary-adrenal axis was greatest. A single 10 mg/kg dose of gepirone significantly elevated levels of corticosterone in plasma (313% after 1 hr) above control values for 2 hr during afternoon trials and for 1 hr (244%) during morning trials. In addition, it was found that the effects of the administration of gepirone and of stress on the levels of corticosterone in plasma were additive. In the light of other work on the hypothalamic-pituitary-adrenal axis, these results suggest that the increased levels of corticosterone, elicited by gepirone, were mediated through a serotonergic action rather than through noradrenergic activity.

Animals↗
PubMed1989

The Kiddie Formal Thought Disorder Rating Scale: clinical assessment, reliability, and validity.

The Kiddie Formal Thought Disorder Story Game and the Kiddie Formal Thought Disorder Scale were administered to schizophrenic, schizotypal, and normal children, aged 5 to 13 years. The story game elicited more elaborate speech samples than did a structural clinical interview focused on psychotic symptomatology. The sum of illogical thinking and loose associations was a reliable kappa = 0.77), sensitive (79%), and specific (90%) indicator of schizophrenia in this sample. It also demonstrated significant developmental changes in the schizophrenic and normal subjects. Incoherence and poverty of content of speech were infrequently rated in both schizophrenic and normal subjects.

Child↗
PubMed1989

Long-term habituation and sensitization of the acoustic startle response in the normal adult human.

The development and independence of short-term and long-term habituation (and short-term sensitization) of the acoustic startle response to repetitive stimuli has been repeatedly demonstrated in the experimental animal. Although short-term habituation (and sensitization) of acoustic startle has been studied in humans, neither long-term habituation nor sensitization has been demonstrated. In this study, long-term habituation (response amplitude decrement) of the blink component of the acoustic startle response occurred in normal men across five consecutive daily sessions of repetitive acoustic stimulation. Long-term sensitization (onset latency shortening) developed after the third day. Both the long-term habituation and sensitization were independent of the day. Both the long-term habituation and sensitization were independent of the short-term habituation, which developed within each daily session.

Adolescent↗
PubMed1988

Ultrastructural alterations in caudate nucleus in aged cats.

These studies provide information on the changes in the ultrastructure in the caudate nucleus of aged cats. The major finding was that there was a decrease in the density of synapses in caudate neuropil. This decrease occurred in animals after 3 years of age and remained relatively constant in older animals. In conjunction with this change a population of unusually long synapses also occurred. These larger synaptic appositions were associated with enlarged spine heads. The caudate also showed a number of qualitative ultrastructural alterations. Many neurons contained accumulations of lipofuscin or lipopigment granules in aged animals. These inclusions occurred in both soma and dendrites of neurons and all types of glial cells. A unique configuration of collapsed agranular cisterns also was observed in aged animals. The present results indicate that decreases in synaptic density may be one morphological event underlying functional alterations observed in caudate neurons in aged cats.

Aging↗
PubMed1988

Kinsey revisited, Part I: Comparisons of the sexual socialization and sexual behavior of white women over 33 years.

This research compared data from two studies of women's sexual behavior--one conducted in the 1940s, the other in the 1980s. The first sample included 3952 white women, ages 18 to 36, drawn from the larger sample of women who participated in the original Kinsey study. The second comprised 122 white women, in the same age range, who had taken part in a recent study of sexual socialization and experiences among women in Los Angeles County, CA. Log-linear analyses were used to control for differences between the samples on age, education, and marital status. Comparisons were conducted in the areas of childhood family characteristics; sexual socialization and education; sexual behavior in childhood, adolescence, and adulthood; contraceptive practices; and child sexual abuse. Results tended to reflect changes that have taken place in society and in patterns of sexual behavior. Differences in sexual socialization pointed to the increased role of the media and the schools and to more relaxed attitudes about nudity in the home. Shifts in sexual behavior were particularly dramatic. As compared to women in the Kinsey sample, the newer subjects began intercourse earlier, were less likely to have a fiance or husband as their first partner, reported a higher number of sexual partners, and participated in a broader range of sexual behaviors. Contraceptive practices differed considerably, especially among never-married women. Women in the new study were also more likely to report instances of child sexual abuse. Methodological and social factors contributing to the findings are discussed.

Adolescent↗
PubMed1988

Kinsey revisited, Part II: Comparisons of the sexual socialization and sexual behavior of black women over 33 years.

Kinsey's findings regarding the sexual behavior of black women were compared with data from a more recent study of sexual socialization and experiences among women in Los Angeles County, Ca. The study examined responses from two groups of college-educated black women, ages 18 to 36, 196 women from the original Kinsey sample and 64 women from the new sample. Log-linear analyses were used to control for differences between the samples on age and marital status. Comparisons were conducted in the areas of childhood family characteristics; sexual socialization and education; sexual behavior in childhood, adolescence, and adulthood; contraceptive practices; and child sexual abuse. Results reflected changes that have taken place in society and in patterns of sexual behavior. Differences in sexual socialization pointed to the increased role of the media and the schools and to more relaxed attitudes about nudity in the home. Shifts in sexual behavior were particularly dramatic. As compared to women in the Kinsey sample, newer subjects began intercourse earlier, were less likely to have a fiance or husband as their first partner, reported a higher number of sexual partners, and participated in a broader range of sexual behaviors. Contraceptive practices differed considerably, especially among never-married women. Women in this study were slightly more likely to report instances of child sexual abuse. Methodological and social factors contributing to the findings are discussed.

Adolescent↗
PubMed1988

Fucosylated forms of alpha-1-antitrypsin that predict unresponsiveness to chemotherapy in ovarian cancer.

We have discovered modified fucosylation of alpha 1-antitrypsin (F-AT) in the sera of ovarian cancer patients. This was detected by SDS/electrophoresis and silver-staining after extracting the sera with the fucose-binding lectin, Lotus tetragonolobus, and was identified as alpha 1-antitrypsin by Western blotting. Initially, high F-AT levels appeared to be related to the recurrence of cancer, but later measurements showed that elevated levels were also present in patients who did not respond to therapy. Using an arbitrary grading system, the level of F-AT was assessed in pairs of sera from 29 ovarian cancer patients undergoing therapy; one specimen collected just after the start of therapy and the other on a later occasion. In 75% of the 15 non-responders, F-AT was higher when measured on a second occasion; whereas in 86% of the 14 responders the second measurement was either unchanged or lower, being frequently undetectable. F-AT levels were also low or undetectable in sera from healthy women. Eight responders were monitored for F-AT throughout cyclophosphamide chemotherapy. Despite a high tumour burden at the start of therapy, all patients had relatively low levels of F-AT and this was maintained throughout remission; the levels only becoming elevated with the recurrence of tumour growth. Increased F-AT expression did not appear to be particularly associated with the presence of liver metastases and frequently predated any clinical signs of a recurrence. The interesting characteristics of these molecules could make them useful in the management of ovarian cancer.

Adult↗
PubMed1987

The use of primary sentence stress by normal, aphasic, and autistic children.

Primary sentence stress is an important aspect of the English prosodic system. Its adequate use is a prerequisite in the development of normal intonation patterns. This study examined the use of primary sentence stress in autistic children with mean length of utterance (MLU) scores between 1.9 and 4.1 morphemes. Normal and aphasic subjects at similar MLU levels served as contrast groups. The primary sentence task required that the subjects verbally respond to a request for information and provide a description of a play situation. Toy manipulation was used to elicit the desired responses. Listener judgment served as the basis for analyzing results. Although all subjects were able to perform the task, differences were seen in the number of correct responses and in the pattern of stress misassignment. These results are at variance with a prediction of stress placement on grammatical grounds. An explanation is offered, based on pragmatic considerations and cognitive developmental trends in young children.

Aphasia↗