Search PubMed⌕ Search

Biomedical subjects

G Parker

Publications and source records attributed to G Parker.

At least 37 records · Page 2Linked to original sources
PubMed2003

Examination stress in Singapore primary schoolchildren: how compliance by subjects can impact on study results.

OBJECTIVE: Examinations are anecdotally viewed as extremely stressful to Singapore schoolchildren. We test this postulate by obtaining parental ratings of children's emotional stress levels longitudinally in a large representative sample of sixth (P6) and fifth (P5) class primary schoolchildren, respectively, exposed and unexposed to a streaming examination. METHOD: Children's stress levels were rated monthly by a parent for 10 months. RESULTS: Analyses failed to find evidence of any differential stress impact across P6 and P5 comparison groups, apart from a subset of P6 children whose parents complied with every monthly survey. CONCLUSION: The streaming examination in the final year of primary school did not emerge as a general stressor to children, but achieved salience within a defined subset of children whose parents were highly study compliant. Study compliance may be a proxy variable of some import, and have wider relevance to other cohort studies and to intervention trials.

Child↗
PubMed2003

Properties of the temperament and character inventory in a Chinese sample.

OBJECTIVE: To determine the influence of language and culture on the temperament and character (TCI) measure in a Chinese sample. METHOD: We translated the TCI into Mandarin and had a non-psychiatric sample of Malaysian Chinese subjects complete the TCI at baseline and at a 1-month retest, with subsets completing English or Mandarin versions alternatively or on both occasions. Analyses examine the TCI factor structure and any impact of language and culture on TCI scoring. RESULTS: We identified age, gender, occupation and language effects on TCI scale scores. Test-retest reliability was high and not compromised by language. Scale internal consistency was also high. Factor analyses of separate sets of TCI scales corresponded strongly to the structure identified in the TCI development studies. CONCLUSION: The results indicate that TCI is likely to have applicability to Chinese subjects, and argue against properties being constrained by the English language or by western culture.

Adolescent↗
PubMed2003

Pseudotumour cerebri, CSF rhinorrhoea and the role of venous sinus stenting in treatment.

We present a case of pseudotumour cerebri (PTC), which is important as it illustrates the effects of chronically raised CSF pressure, the relationship between PTC and venous sinus obstruction and the successful treatment of PTC using a venous sinus stent. A 38-year-old woman, previously diagnosed with PTC and unsuccessfully treated 10 years previously re-presented with spontaneous CSF rhinorrhoea. Imaging revealed dramatic changes of chronically raised CSF pressure and a defect in the anterior cranial fossa. The CSF leak was corrected surgically and a lumbo-peritoneal shunt inserted to correct a large postoperative subgaleal CSF collection. Direct retrograde cerebral venography (DRCV) demonstrated venous sinus obstruction due to a filling defect. This was associated with a pressure gradient and a high superior sagittal sinus pressure. The venous sinus obstruction was successfully treated with a venous sinus stent and the lumbo-peritoneal shunt was removed. Chronically raised CSF pressure in untreated cases of PTC may cause widespread changes in the skull, which in this case, culminated in a spontaneous CSF leak despite relatively mild headache and visual symptoms. Furthermore, cases of PTC secondary to venous sinus obstruction may be successfully treated using venous sinus stenting. The index of suspicion for venous sinus stenosis or obstruction should be raised in the investigation of patients with PTC.

Adult↗
PubMed2002

Cognitive-based measures screening for depression in the medically ill: the DMI-10 and the DMI-18.

OBJECTIVE: We suggest that the identification of depression in the medically ill (DMI) might be improved by focussing on cognitive features. METHOD: We recruited 302 patients to complete our provisional cognitive-based measure. Subsets also completed one of two comparator screening measures, either the Hospital and Anxiety Depression Scale (HADS) or the Beck Depression Inventory for Primary Care (BDI-PC). One hundred and sixty patients were then assessed by a psychiatrist who estimated whether they were 'clinically depressed' and who also administered a standardized interview for depression (the CIDI). RESULTS: Analyses identified items discriminating clinically depressed and non-depressed individuals, allowing development of brief (10-item) and extended (18-item) measures. The two new measures were compared with the HADS and the BDI-PC in discriminating depressed and non-depressed medically ill patients. CONCLUSION: A cognitive construct-based approach to assessing depression in the medically ill appears strongly supported. We provide brief (DMI-10) and extended (DMI-18) measures that appear to have utility as screening instruments. Consideration of the discriminating items may also assist clinical decision making.

Chronic Disease↗
PubMed2002

Gender differences in depression risk and coping factors in a clinical sample.

OBJECTIVE: To examine gender differences in depression risk and coping factors in a clinical sample of patients with a diagnosis of DSM-IV major depression. METHOD: Patients were assessed for substance use and abuse, family history of psychiatric disorder, interpersonal depressogenic factors and lifetime history of anxiety disorders. Trait anxiety, coping styles when depressed, parental bonding, marital features and personality style were also measured. Patients were reassessed at 12-month follow-up. RESULTS: There were few gender differences in experience of depression (either in duration, type or severity prior to treatment) in a group with established episodes of major depression but women reported more emotional arousability when depressed. Women reported higher rates of dysfunctional parenting and childhood sexual abuse, and rated their partners as less caring and as more likely to be a depressogenic stressor. Men were more likely to have a generalized anxiety disorder at assessment, to use recreational drugs prior to presentation. Men were rated as having a more rigid personality style and 'Cluster A' personality traits both at assessment and follow-up. CONCLUSION: There were few gender differences in severity or course of established episodes of major depression. Gender differences were related to levels of arousal, anxiety disorders, and repertoires for dealing with depression, rather than depressive symptoms per se.

Adaptation, Psychological↗
PubMed2002

Examining the utility of a temperament model for modelling non-melancholic depression.

OBJECTIVE: Depression is currently modelled dimensionally, along severity, duration and recurrency dimensions. An alternative model allows dimensional expressions of temperament and personality to influence risk to onset as well as persistence. Here, we examine the utility of a temperament model. METHOD: A questionnaire assessing temperament dimensions and a number of depression variables was administered to a large routine general practice sample and with the temperament measure also completed by a small clinical sample. RESULTS: 'Anxious worrying' and 'irritable' dimensions were identified as internalizing and externalizing expressions of a trait anxiety dimension, three other 'temperament' dimensions (i.e. 'introversion', 'self-centred' and 'obsessive') were refined, while a 'self-blame' dimension intruded into the factor analytic solution. High scores on the 'anxious worrying' dimension were associated with all depression parameters. The 'irritable', 'introversion' and 'self-blame' dimensions were less clearly linked with depression variables, while higher scores on the 'self-centred' and 'obsessional' dimensions did not appear to increase the chance of depression onset, persistence or recourse to treatment. CONCLUSION: A temperament-based approach appears to have some conceptual utility in modelling depression, and particularly, the non-melancholic disorders. It is likely, however, to require complementing with refined at-risk personality dimensions.

Adult↗
PubMed2002

Differential effectiveness of newer and older antidepressants appears mediated by an age effect on the phenotypic expression of depression.

OBJECTIVE: A possible mechanism whereby the serotonin reuptake inhibitor (SSRI) antidepressants may not (overall) be as effective as the tricyclic (TCA) antidepressants is explored. METHOD: Clinical psychiatrists rated the effectiveness of past antidepressant medications in a clinical panel study of patients with a major depressive disorder, with 200 having previously received a TCA and 219 an SSRI. RESULTS: Analyses indicated decreased SSRI effectiveness with age in those with the melancholic subtype. TCA effectiveness appeared uninfluenced by age and depressive subtype. CONCLUSION: Findings suggest why the broader-based TCAs may be more effective than the SSRIs in implicating age and depressive subtype influences.

Adult↗
PubMed2002

Cranial venous outflow obstruction in the pseudotumour syndrome: incidence, nature and relevance.

This study reports a retrospective analysis of the evidence of cranial venous outflow pathology in 188 patients with pseudotumour syndrome (PTS) investigated over the period 1968-1999. Standard methods of investigation appropriate to the period were used, i.e. cerebral angiography, CT and MR scanning. Recently, some patients had specific venous studies including intraluminal cranial venous sinus pressure measurements. A sub-group (25 patients) was investigated for haematological abnormalities. The overall incidence of cranial venous outflow abnormality was 19.7% (37 cases). In decades, related to the predominant investigative method, the figures were: to 1979, 4.2% (2 cases); to 1989, 15.0% (8 cases); to 1999, 31.0% (27 cases). A cause of the venous abnormality was identified in 20 cases, most commonly haematological and iatrogenic. In 17 patients (all females) no cause was identified. Fifteen of the 25 patients (60%) tested specifically were found to have a haematological abnormality, although no correlation was shown between this and a demonstrable venous outflow abnormality. The conclusion was drawn that there is a high incidence (close to one-third) of venous outflow abnormalities in PTS with detailed investigation. Issues of mechanism and therapy are discussed.

Adolescent↗
PubMed2002

Olanzapine augmentation in the treatment of melancholia: the trajectory of improvement in rapid responders.

It has been suggested that the atypical antipsychotic drugs may induce a rapid improvement in individuals with melancholic depression. This might reflect a specific or non-specific effect on mood and other parameters. To examine this issue, ten consecutive patients, for whom olanzapine augmentation was judged a clinically appropriate strategy, were asked to complete daily ratings of depression severity and component features for 1 week. Of the six rapid responders, there was a 52% group improvement in the first day and 89% improvement at 1 week. Item analyses suggested the most rapid impact was evident for insomnia, compared to a slower and linear improvement in depressed mood. Such findings may assist in an understanding of the mechanisms underlying augmentation with atypical neuroleptic drugs.

Adult↗
PubMed2001

Agonistic behavior in groups of limbic epileptic male rats: pattern of brain damage and moderating effects from normal rats.

Different ratios of normal male rats and male rats in which limbic seizures had been induced by a single systemic injection of lithium and pilocarpine were housed in groups of six. The group ratios ranged along the continuum from all normal rats to all experimental rats. The average numbers of episodes of boxing, biting and mounting--thrusting per rat per hour per group were recorded by direct observation (red light) for 1 h during the midscotophase. Groups that contained less than two normal rats exhibited significantly elevated amounts of agonistic (boxing, biting) behavior but not mounting behavior. Multiple regression analyses showed that combinations of neuronal loss within only two to three areas accommodated at least 50% of the variance in the numbers of these behaviors.

Agonistic Behavior↗
PubMed2001

Tularemia as a biological weapon: medical and public health management.

OBJECTIVE: The Working Group on Civilian Biodefense has developed consensus-based recommendations for measures to be taken by medical and public health professionals if tularemia is used as a biological weapon against a civilian population. PARTICIPANTS: The working group included 25 representatives from academic medical centers, civilian and military governmental agencies, and other public health and emergency management institutions and agencies. EVIDENCE: MEDLINE databases were searched from January 1966 to October 2000, using the Medical Subject Headings Francisella tularensis, Pasteurella tularensis, biological weapon, biological terrorism, bioterrorism, biological warfare, and biowarfare. Review of these references led to identification of relevant materials published prior to 1966. In addition, participants identified other references and sources. CONSENSUS PROCESS: Three formal drafts of the statement that synthesized information obtained in the formal evidence-gathering process were reviewed by members of the working group. Consensus was achieved on the final draft. CONCLUSIONS: A weapon using airborne tularemia would likely result 3 to 5 days later in an outbreak of acute, undifferentiated febrile illness with incipient pneumonia, pleuritis, and hilar lymphadenopathy. Specific epidemiological, clinical, and microbiological findings should lead to early suspicion of intentional tularemia in an alert health system; laboratory confirmation of agent could be delayed. Without treatment, the clinical course could progress to respiratory failure, shock, and death. Prompt treatment with streptomycin, gentamicin, doxycycline, or ciprofloxacin is recommended. Prophylactic use of doxycycline or ciprofloxacin may be useful in the early postexposure period.

Anti-Bacterial Agents↗
PubMed2001

Effects of a 2- to 4-week course of repetitive transcranial magnetic stimulation (rTMS) on neuropsychologic functioning, electroencephalogram, and auditory threshold in depressed patients.

BACKGROUND: The safety of repetitive transcranial magnetic stimulation (rTMS) has only previously been formally studied in volunteers receiving a single session of stimulation or in a small number of depressed subjects receiving a 2-week treatment course. This study examined safety issues in depressed subjects receiving up to 4 weeks of rTMS. Efficacy results from this study have been previously reported. METHODS: Eighteen subjects with DSM-IV major depression participated in a 2-week, parallel, double-blind, sham-controlled study of rTMS treatment. Twelve subjects then went on to receive 4 weeks active rTMS in an open follow-up. We examined the effects of rTMS on neuropsychologic function (up to 4 weeks), auditory threshold (up to 6 weeks exposure to rTMS noise), and an electroencephalogram (after 2 weeks). Data were analyzed by repeated measures analysis. RESULTS: There were trends for improvement in neuropsychologic performance, probably due to practice effects. No mean changes in auditory threshold occurred, but two patients showed mild high-frequency hearing loss after several weeks of rTMS. Electroencephalograms in two patients, one of whom had sham stimulation, showed minor abnormality. CONCLUSIONS: No significant mean deficits were demonstrated in this cohort. Overall, rTMS for up to 4 weeks is safe, but individual results suggest caution and the need for further investigation of the safety of several weeks of rTMS.

Adult↗
PubMed2001

Botulinum toxin as a biological weapon: medical and public health management.

OBJECTIVE: The Working Group on Civilian Biodefense has developed consensus-based recommendations for measures to be taken by medical and public health professionals if botulinum toxin is used as a biological weapon against a civilian population. PARTICIPANTS: The working group included 23 representatives from academic, government, and private institutions with expertise in public health, emergency management, and clinical medicine. EVIDENCE: The primary authors (S.S.A. and R.S.) searched OLDMEDLINE and MEDLINE (1960-March 1999) and their professional collections for literature concerning use of botulinum toxin as a bioweapon. The literature was reviewed, and opinions were sought from the working group and other experts on diagnosis and management of botulism. Additional MEDLINE searches were conducted through April 2000 during the review and revisions of the consensus statement. CONSENSUS PROCESS: The first draft of the working group's consensus statement was a synthesis of information obtained in the formal evidence-gathering process. The working group convened to review the first draft in May 1999. Working group members reviewed subsequent drafts and suggested additional revisions. The final statement incorporates all relevant evidence obtained in the literature search in conjunction with final consensus recommendations supported by all working group members. CONCLUSIONS: An aerosolized or foodborne botulinum toxin weapon would cause acute symmetric, descending flaccid paralysis with prominent bulbar palsies such as diplopia, dysarthria, dysphonia, and dysphagia that would typically present 12 to 72 hours after exposure. Effective response to a deliberate release of botulinum toxin will depend on timely clinical diagnosis, case reporting, and epidemiological investigation. Persons potentially exposed to botulinum toxin should be closely observed, and those with signs of botulism require prompt treatment with antitoxin and supportive care that may include assisted ventilation for weeks or months. Treatment with antitoxin should not be delayed for microbiological testing.

Antitoxins↗
PubMed2001

Depression in Singapore: failure to demonstrate an age effect on clinical features.

OBJECTIVES: Studies comparing older and younger depressed patients have variably identified differing and similar clinical feature patterns, an inconsistency requiring clarification and explanation. If influential, age may have a true phenotypic effect or be a secondary influence reflecting depressive sub-type differences. If age is primarily influential, then, after controlling for depressive sub-type differences its effect should impact on clinical features - even in non-western regions. METHODS: We therefore undertook a study in Singapore, comparing 42 elderly and 28 younger patients of a Singapore psychiatric hospital, and with the diagnostic sub-type profile similar across the age-based groups. RESULTS: Despite the elderly group being some 35 years older, both at first episode and when surveyed, and having a distinctly higher rate of physical disorders, few clinical differences were identified. While the elderly group reported a less severe depressed mood and more 'somatic' symptoms, analyses indicated that such differences were accounted for by education and language factors, and were compatible with the view that Chinese subjects historically report depression more 'somatically'. CONCLUSION: We conclude that, in a non-western, largely Chinese sample of depressed patients, few differences in the phenotypic expression of depression were identified, perhaps reflecting similar distributions of depressive sub-types across the groups, an issue which may have muddied interpretation of western studies.

Adolescent↗
PubMed2001

Do the Chinese somatize depression? A cross-cultural study.

BACKGROUND: A large literature argues for the Chinese--whether in mainland China or elsewhere--being highly likely to express depression somatically, leading to predictable detection and diagnostic difficulties. If true, detection might be assisted if a set of somatic proxies of depression were identified, and this was the principal initial objective in mounting this study. METHODS: We studied two sets of depressed outpatients, one of Malaysian Chinese and the other of Australian Caucasians, matched by age and sex. We identified the prime symptom nominated by them when they first sought assistance, and required them to complete an inventory of both somatic and cognitive symptoms, and rank the three items they judged as most capturing their distress. RESULTS: The Chinese were distinctly more likely to nominate a somatic symptom as their presenting complaint (60% vs 13%), while the Australian subjects were more likely to nominate depressed mood, cognitive and anxiety items. Responses to the inventory established that the Chinese did score somewhat higher on a somatic set of items, but differed far more distinctly in being less likely to affirm cognitive items of depression, resulting in significantly lower total inventory scores. Variation across the contrast samples in acknowledging the presence of symptoms did not relate simply to the prevalences of those symptoms. CONCLUSIONS: Our failure to identify a culture-specific somatic factor as a proxy of depression, together with establishing a high rate of somatic and related items (e. g. insomnia) in both samples, may largely reflect the phenomenon of 'corporization', whereby depressed patients irrespective of culture are more likely to experience and report in response to a 'somatosensory amplification' influence.

Adult↗