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Biomedical subjects

A Taylor

Publications and source records attributed to A Taylor.

At least 235 records · Page 13Linked to original sources
PubMed1999

Antecedents and complications of trauma in boys with ADHD: findings from a longitudinal study.

OBJECTIVE: To examine the relationship between trauma and attention-deficit hyperactivity disorder (ADHD), evaluating whether ADHD increases the risk for trauma, the risk for posttraumatic stress disorder (PTSD), or the risk for trauma-associated psychopathology. METHOD: Data from a longitudinal sample of 260 children and adolescents with and without ADHD were examined. All were evaluated comprehensively with assessments in multiple domains of functioning including systematic assessments of trauma and PTSD. Comparisons were made between traumatized and nontraumatized youths with and without ADHD. RESULTS: No meaningful differences were detected in comparisons between ADHD and control children, either in the rate of trauma exposure or in the development of PTSD. Although trauma was associated with the development of major depression, this effect was independent of ADHD status. In contrast, bipolar disorder at baseline assessment was a significant risk factor for subsequent trauma exposure. CONCLUSIONS: ADHD was not found to be a risk factor for either trauma exposure or PTSD, but childhood mania was. If confirmed, this finding stresses the potential severe clinical sequelae of childhood mania in children.

Adolescent↗
PubMed1999

Psychiatric disorder and cognitive function in a family with an inherited novel mutation of the developmental control gene PAX6.

The PAX family of developmental control genes are known to play important roles in the early patterning of the central nervous system. One member of this family, PAX6, is involved in eye development in invertebrates as well as in mouse and man, but is also widely expressed in the developing forebrain. Humans with a mutation in this gene have abnormalities of eye development, and the results presented here suggest, for the first time, that this mutation may also be associated with subtle abnormalities of frontal lobe function in the family studied. We carried out genotyping of individuals within a single family, with and without the characteristic eye abnormalities of PAX6 mutation, and only those individuals with the mutation showed significant abnormalities on tests of frontal lobe function. These individuals also had higher rates of psychiatric disorder. PAX6 is highly conserved between mouse and man, and although the neuroanatomical phenotype associated with PAX6 heterozygosity has only been studied in mice, the resultant cellular disorganization seen in mice is likely to be present in the human forebrain. Although these mice have no obvious behavioural phenotype, the results presented here suggest that humans with the equivalent mutation display a neurobehavioural phenotype.

Adolescent↗
PubMed1999

Minimum requirements for remote realtime fetal tele-ultrasound consultation.

We studied the transmission bandwidth required for accurate diagnoses when performing realtime fetal tele-ultrasound consultations. The study was divided into three phases. In phase I, three experienced clinicians evaluated the quality of ultrasound images transmitted at various bandwidths (internally looped back within Brisbane) using eight commercially available codecs at random. The two codecs that performed best proceeded to phase 2, in which a realtime video-link of up to 2 Mbit/s was set up between Brisbane and Townsville (1,500 km apart). Testing with a standard video-tape was performed at seven different bandwidths selected at random, with four clinicians (who were blinded to the equipment and bandwidths used). The optimum line rates for transmission were determined, and testing was then performed using these line rates for fetuses with various anomalies (phase 3). The results showed significant differences in performance according to bandwidths used, but not according to observers. Bandwidths were grouped into three levels. At level I (256 kbit/s) the performance was significantly worse than at level II (384, 512 or 768 kbit/s), which was in turn worse than that at level III (1, 1.5 or 2 Mbit/s). However, within each level, performance at one bandwidth was not significantly different from that at the others. The most cost-effective transmission rates therefore appeared to be 384 kbit/s and 1 Mbit/s. Further testing with fetuses affected by various anomalies confirmed that the majority could be diagnosed using a 384 kbit/s link, with slight improvement in evaluation when the bandwidth was increased to 1 Mbit/s.

Analysis of Variance↗
PubMed1999

A non-comparative multi-centre clinical evaluation of a new hydropolymer adhesive dressing.

This study evaluates the performance of a new hydropolymer adhesive dressing in the treatment of chronic or acute wounds, in the presence of blood and/or low levels of exudate, in 74 patients, in a five-site multi-centre non-comparative clinical trial of four weeks' duration. The primary efficacy variable was defined as the incidence of central island dressing adherence to the wound bed in the final stages of healing. The hydropolymer dressing performed extremely well with 98.4% (240 out of 244) of the dressings not adhering to the wound bed.

Acute Disease↗
PubMed1999

Effects of PMA and transcription factors on ovine interferon-tau transactivation in various cell lines.

Interferon-tau (IFNtau) is produced by the trophectoderm of ruminant ungulates and its gene transactivation in vitro has so far been achieved only in human choriocarcinoma cells, JAR and JEG3. To examine if ovine IFNtau gene transactivation could be induced in cells other than JAR or JEG3 cells and its activation could be aided by the expression of a protooncogene(s), a transient transfection system was developed with the upstream region of ovine IFNtau gene that had been inserted into the chloramphenicol acetyltransferase (CAT) reporter plasmid (IFNtau-CAT). The effect of a protein kinase C (PKC) activator, phorbol 12-myristate 13-acetate (PMA), on IFNtau-CAT transcriptional activity was examined in JEG3, human embryonic kidney (293), HeLa and Vero cells. Upon transfection and PMA treatment, ovine IFNtau gene was transactivated in two unrelated cell lines, JEG3 and 293 cells. Since IFNtau-CAT was not induced in HeLa or Vero cells, HeLa and JEG3 cells were further examined for their ability to support IFNtau-CAT transactivation in a co-transfection system. While the expression of c-myc, interferon regulatory factor 1 or 2 (IRF-1 or IRF-2) was not effective, CAT activity was strongly enhanced in both JEG3 and HeLa cells with the co-transfection of c-Jun or c-Jun plus c-Fos. These data suggest that ovine IFNtau gene transcription induced by PMA is not specific for trophoblast cells and a protooncogene, c-jun, is a downstream effector of PMA activated nuclear factors in its signal transduction cascade resulting in IFNtau gene transactivaion.

Animals↗
PubMed1999

Synchronization, anticipation, and consistency in motor timing of children with dimensionally defined attention deficit hyperactivity behaviour.

We tested the hypothesis that children with hyperactive behaviour are impaired in the temporal organization of their motor output. The performance of 11 boys, scoring above a cut-off on standard scales of overactivity and inattention, was compared to that of controls in progressively more complex Motor-timing tasks. The tasks administered required self-paced and externally paced Sensorimotor Synchronization and Sensorimotor Anticipation. Deficits at a perceptual level were investigated with a Time-discrimination task. As hypothesized, we found that hyperactive children had no deficits in their perception of time but were impaired in timing their motor output. Hyperactive children were more inconsistent than controls in maintaining a freely chosen tapping rhythm, in synchronizing and in anticipating their motor response to external visual stimulation.

Attention Deficit Disorder with Hyperactivity↗
PubMed1999

Avoidant/ambivalent attachment style as a mediator between abusive childhood experiences and adult relationship difficulties.

The role of attachment style, self-esteem, and relationship attributions as possible mediators between abusive childhood experiences and difficulties in establishing supportive love relationships in adulthood were investigated in a sample of women known to be at risk of experiencing relationship problems. Measures of child abuse, the quality of love relationships, and the three potential mediators were made concurrently in adulthood. Participants who had experienced child abuse were found to be six times more likely to be experiencing difficulties in the domain of adult love relationships than those who had not. Self-esteem and relationship attributions were not found to be related to child abuse. When both child abuse and avoidant/ambivalent attachment style were considered together avoidant/ambivalent attachment style, but not child abuse, was found to be related to relationship difficulties. These findings indicate that avoidant/ambivalent attachment style, but not self-esteem and relationship attributions, is a mediating factor in the route from child abuse to adult relationship abilities.

Adult↗
PubMed1999

Health related quality of life in a population sample with arthritis.

OBJECTIVE: To determine the prevalence and health related quality of life of a community sample of people with arthritis and compare it with persons with other chronic diseases and the healthy population in South Australia. METHODS: A representative population survey by trained interviewers in autumn 1995 using a multi-stage, systematic, clustered area sample of 4200 urban and country households. There were 3001 (73.6%) respondents aged 15 or over. Subjects were asked, "Have you ever been told by a doctor that you have arthritis?" and "What type?", in addition to the Medical Outcome Survey Short Form-36 (SF-36) health status survey. RESULTS: Medically confirmed arthritis was self-reported in 666 (22.1%) as osteoarthritis (OA) (8.6%), rheumatoid arthritis (RA) (4.0%), and other, or unspecified arthritis (9.6%). People with arthritis were more likely to be female, aged, and of lower socioeonomic status. SF-36 scores were compared to nonarthritic subjects and adjusted for differences in age, sex, and occupational status. Scores were significantly lower for respondents with arthritis, compared with the rest of the population across all subscales of the SF-36 (p<0.05). This was most marked in the subscales measuring physical function and pain. CONCLUSION: Self-reported arthritis is common in the South Australian population, particularly in those aged over 65 years. Arthritis has a major impact on the health related quality of life in the community setting.

Adolescent↗
PubMed1999

Hyperactivity and reading disability: a longitudinal study of the nature of the association.

In order to investigate the possible causal relationships between hyperactivity and educational underachievement that might account for their frequent co-occurrence, four groups of boys, defined by the presence or absence of hyperactivity and specific reading retardation, were identified in an epidemiological study of 7 8-year-old children. They were examined in detail by means of parental interviews and psychological tests and reassessed 9 years later at the age of 16-18 years on a similar range of measures. The findings provided little support for the idea that persistent reading disabilities either lead to the development of hyperactivity de novo or increased the likelihood that hyperactivity, when present, would persist. Similarly, although features of hyperactivity persisted to follow-up, there was little evidence that they either lead to the development of reading disabilities or increased the likelihood that reading disabilities, when present, would persist. Socioeconomic adversity and a history of speech therapy were more common in the group with both hyperactivity and reading disability, but the strength of these associations made it unlikely that these factors could account for the frequent co-occurrence of the two conditions.

Adolescent↗
PubMed1998

Calorie restriction, stress and the ubiquitin-dependent pathway in mouse livers.

Calorie restriction (R) is the only known method to delay the aging process and extend mean and maximal lifespan in rodents. R has been shown to delay the age-related accumulation of damaged proteins and to protect organisms from various stresses which can produce damaged proteins. Such stresses include irradiation, heat shock, and oxidative stress. The ubiquitin- and ATP-dependent proteolytic pathway (UPP) has been associated with the degradation of abnormal and/or damaged proteins. We examined the effect of diet and oxidative stress on activities of the UPP in supernatants from livers taken from 23-month-old Emory mice which had been exposed to an in-vivo injection of paraquat. Paraquat induces oxidative stress by generating superoxide radicals. In livers from non-stressed animals, steady-state levels of endogenous ubiquitin conjugates, de novo conjugate formation, and E1 and E2 activities were significantly lower in R animals than in control (C) animals. However, after exposure to paraquat, levels of endogenous ubiquitin conjugates were significantly higher in R versus C animals, and de novo conjugate formation and E1 and E2 activities in R animals rose to levels which were indistinguishable from levels of these activities noted in C animals. R was associated with an increased ability to degrade beta-lactoglobulin by the UPP after an oxidative stress was imposed. Ability to degrade beta-lactoglobulin by the C or R livers in non-stressed animals was not significantly different. Taken together, these data indicate that oxidative stress in R animals is associated with enhanced levels of ubiquitin conjugates and that this enhancement may be due to an increase in UPP activity. These data also indicate that the ability to form ubiquitin conjugates and the UPP system does not change with oxidative stress in C animals. The latter is consistent with prior reports that suggests that older C animals may already be in a state of enhanced oxidative stress and that activities of the UPP provide a sensitive indicator of levels of cellular redox status.

Adenosine Triphosphate↗
PubMed1998

The effects of aging and calorie restriction on plasma nutrient levels in male and female Emory mice.

We examined the effect of diet, age (4.5, 13 and 23 months), and sex on plasma levels of retinol, tocopherol, ascorbate, cholesterol, glucose and glycohemoglobin in male and female Emory mice which were fed control (C) and 50% calorie restricted (R) diets. Results showed that C fed animals tended to have higher levels of plasma ascorbate (50-71%), cholesterol (23-71%), glucose (38-81%) and glycohemoglobin (50%). However, these diet differences varied with the age and sex of the animals. Plasma retinol levels were lower only in R males vs. C males (50%). Novel sex-related differences in levels of plasma retinol (2-fold higher in C male mice than in C or R female mice) are described. Aging was associated with trends towards lower levels of plasma ascorbate (14-25%), glucose (34-36%) and glycohemoglobin (47-57%) from 4.5 to 23 months of age. However, these age differences depended upon the diet and sex of the animals. These data suggest that lower plasma levels of glucose, glycosylated hemoglobin and cholesterol may be causally related to the life extension noted in R animals since elevated levels of these moieties have been related to aging. Since oxidative stress is thought to be causally related to aging it appears unlikely that retinol, tocopherol and ascorbate are causally related to R-induced life-extension.

Aging↗
PubMed1998

Aging, calorie restriction and ubiquitin-dependent proteolysis in the livers of Emory mice.

Calorie restriction (R), the only known method to delay the aging process and extend mean and maximal lifespan, has been shown to delay the age-related decline in protein degradation. There are several proteolytic pathways. The ubiquitin- and ATP-dependent proteolytic pathway (UPP) is frequently associated with degradation of damaged abnormal and/or regulatory proteins. We examined the effect of aging and R on supernatants of livers taken from young (4.5 months) and old (23 months) Emory mice. Aging was associated with increased levels of endogenous ubiquitin conjugates, enhanced ability to form high molecular weight conjugates and ubiquitin activating (E1) and ubiquitin conjugating (E2) activity in the control (C) liver supernatants. The age-related increase in levels of endogenous ubiquitin conjugates in liver appears to be primarily due to increased E1 and E2 activities. R prevented the age-related increase in E1 and E2 activity, and thus prevented the age-related increase in levels of ubiquitin conjugates. In spite of the age-related increase in ubiquitin conjugates, no age-related changes in ubiquitin-dependent proteolytic pathway were observed in the C animals. R was associated with an enhanced ability (130%) to degrade beta-lactoglobulin by the ubiquitin-dependent proteolytic pathway in livers from 4.5-month-old animals relative to age-matched C livers. However, rates of the ubiquitin-dependent degradation of beta-lactoglobulin in the 23-month-old C and R animals were indistinguishable. There were no age- or diet-related differences in the ability to degrade another substrate, oxidized ribonuclease (RNase).

Adenosine Triphosphate↗
PubMed1998

Effect of turmeric, turmerin and curcumin on H2O2-induced renal epithelial (LLC-PK1) cell injury.

Cell injury by oxidative stress is an important mechanism for renal epithelial cell destruction. This study observed the protective effect of turmeric and its constituents on H2O2-induced injury. Turmeric consists of a water soluble turmerin and lipid soluble curcumin with potent antioxidant properties. Confluent LLC-PK1 cells were labelled with 3H-arachidonic acid at 0.1 microCi/ml over 18 h and then further labelled with 51Cr. Turmeric ( 100 microg/ml-0.1 microg/ml), turmerin (800 ng/ml-0.8 ng/ml), curcumin (100 microg/ml-0.1 microg/ml), vitamin E (100 microM) and 21-aminosteroid (20 microM) were added and incubated for 3 h at 37 degrees C in 24-well plate. The adherent cells were washed and incubated for 3 h with 1.5 mM H2O2 at 37 degrees C. 3H-arachidonic acid release, 51Cr release and lipid peroxidation by the thiobarbituric acid reaction was determined. Turmeric ( 100 microg/ml) and curcumin (100 microg/ml, 10 microg/ml) gave as much protection as did vitamin E in both chromium release assay and lipid degradation while Turmeric (100 microg/ml) and curcumin (100 microg/ml) gave comparable inhibition of lipid peroxidation. Turmerin and 21-aminosteroid showed no protection. These findings provide evidence that turmeric and curcumin provide protection against oxidative stress in a renal cell line.

Animals↗
PubMed1998

The effect of HLA-DR genes on susceptibility to and severity of ankylosing spondylitis.

OBJECTIVE: To analyze the effect of HLA-DR genes on susceptibility to and severity of ankylosing spondylitis (AS). METHODS: Three hundred sixty-three white British AS patients were studied; 149 were carefully assessed for a range of clinical manifestations, and disease severity was assessed using a structured questionnaire. Limited HLA class I typing and complete HLA-DR typing were performed using DNA-based methods. HLA data from 13,634 healthy white British bone marrow donors were used for comparison. RESULTS: A significant association between DR1 and AS was found, independent of HLA-B27 (overall odds ratio [OR] 1.4, 95% confidence interval [95% CI] 1.1-1.8, P = 0.02; relative risk [RR] 2.7, 95% CI 1.5-4.8, P = 6 x 10(-4) among homozygotes; RR 2.1, 95% CI 1.5-2.8, P = 5 x 10(-6) among heterozygotes). A large but weakly significant association between DR8 and AS was noted, particularly among DR8 homozygotes (RR 6.8, 95% CI 1.6-29.2, P = 0.01 among homozygotes; RR 1.6, 95% CI 1.0-2.7, P = 0.07 among heterozygotes). A negative association with DR12 (OR 0.22, 95% CI 0.09-0.5, P = 0.001) was noted. HLA-DR7 was associated with younger age at onset of disease (mean age at onset 18 years for DR7-positive patients and 23 years for DR7-negative patients; Z score 3.21, P = 0.001). No other HLA class I or class II associations with disease severity or with different clinical manifestations of AS were found. CONCLUSION: The results of this study suggest that HLA-DR genes may have a weak effect on susceptibility to AS independent of HLA-B27, but do not support suggestions that they affect disease severity or different clinical manifestations.

Age of Onset↗