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Biomedical subjects

G Parker

Publications and source records attributed to G Parker.

At least 91 records · Page 5Linked to original sources

Plague as a biological weapon: medical and public health management. Working Group on Civilian Biodefense.

OBJECTIVE: The Working Group on Civilian Biodefense has developed consensus-based recommendations for measures to be taken by medical and public health professionals following the use of plague as a biological weapon against a civilian population. PARTICIPANTS: The working group included 25 representatives from major academic medical centers and research, government, military, public health, and emergency management institutions and agencies. EVIDENCE: MEDLINE databases were searched from January 1966 to June 1998 for the Medical Subject Headings plague, Yersinia pestis, biological weapon, biological terrorism, biological warfare, and biowarfare. Review of the bibliographies of the references identified by this search led to subsequent identification of relevant references published prior to 1966. In addition, participants identified other unpublished references and sources. Additional MEDLINE searches were conducted through January 2000. CONSENSUS PROCESS: The first draft of the consensus statement was a synthesis of information obtained in the formal evidence-gathering process. The working group was convened to review drafts of the document in October 1998 and May 1999. The final statement incorporates all relevant evidence obtained by the literature search in conjunction with final consensus recommendations supported by all working group members. CONCLUSIONS: An aerosolized plague weapon could cause fever, cough, chest pain, and hemoptysis with signs consistent with severe pneumonia 1 to 6 days after exposure. Rapid evolution of disease would occur in the 2 to 4 days after symptom onset and would lead to septic shock with high mortality without early treatment. Early treatment and prophylaxis with streptomycin or gentamicin or the tetracycline or fluoroquinolone classes of antimicrobials would be advised.

Anti-Bacterial Agents↗

Bilateral uveal effusion associated with scleral thickening due to amyloidosis.

A 45-year-old man with primary systemic amyloidosis was found to have bilateral uveal effusions secondary to thickened sclera according to magnetic resonance imaging of the orbits. The patient was treated with bilateral sclerectomies and vortex vein decompression, and had an excellent outcome. Light microscopy of excised sclera revealed severe infiltration of the tissue by amyloid. To our knowledge, this is the first report of amyloid infiltration of the sclera leading to uveal effusion. Arch Ophthalmol. 2000;118:1293-1295

Amyloidosis↗

Evaluation and validation of a measure profiling needs and problems of psychiatric patients in the community: a Malaysian study.

BACKGROUND: The Profile of Community Psychiatry Clients (PCPC) was developed in a Sydney-based sample of those with a mental illness as a 35-item measure of likely need for service recognition, review and possible assistance. METHODS: This study has three principal objectives. Firstly, to test the utility of the PCPC measure in a very different region and culture. Secondly, to review the factor structure in an independent sample. Thirdly, to pursue the extent to which the PCPC might serve as a measure of likely need, by obtaining three differing reference viewpoints of need (i.e. clients, their carers, and case managers) and examining responses against PCPC scores. The PCPC was given to a sample of 333 Malaysian clients living in the community, together with two other measures of morbidity and disability. In addition, case managers, family members and clients were requested to directly rate the level of need for service assistance. RESULTS: A principal components analysis favoured a six-factor solution, with PCPC factor scores and total scores intercorrelated with subscale and total scores on the Life Skills Profile (LSP) and Health of the Nation Outcome Scales (HoNOS). The correlation coefficients supported the concurrent validity of the derived PCPC scales. Family members rated the clients' needs as greater than did case managers who, in turn, rated severity of needs greater than the clients themselves. Most importantly, PCPC scores correlated more highly than did LSP and HoNOS scores with need estimates derived by all three rating groups, providing strong support for the PCPC meeting its objective as a measure of putative need. In addition, a refined 23-item version of the PCPC was derived, which retained the capacity of the PCPC to correlate strongly with needs estimates. CONCLUSIONS: This Malaysian study supports the use of the PCPC in a culture where service provision and family support for those with a mental illness vary considerably from Western regions, while its validation as a measure of need for service is supported.

Adult↗

The nature of bipolar depression: implications for the definition of melancholia.

AIM: To examine if melancholic depression is over-represented in those with 'bipolar depression' and, if confirmed, to use that phenomenon to assist the clinical definition of melancholia. METHODS: We contrast 83 bipolar and 904 unipolar depressed patients on three melancholic sub-typing systems (DSM, Clinical and CORE system) and compare representation of their clinical depressive features. RESULTS: By all three melancholic sub-typing systems, the bipolar patients were more likely to receive diagnoses of 'melancholia' and of psychotic depression. To the extent that this differential prevalence of depressive sub-types was reflected in varying patterns of clinical features, we so indirectly identified a set of items defining 'melancholia'. By such a strategy, melancholia was most clearly distinguished by behaviourally-rated psychomotor disturbance. While a number of 'endogeneity symptoms' were significantly over-represented, logistic regression analyses refined the set to psychomotor disturbance (both as a symptom and as a sign) and pathological guilt. We also established a distinctly higher prevalence of bipolar depression in those where a refined diagnosis of melancholia was made. CONCLUSIONS: Bipolar depression appears to be more likely to be 'melancholic' in type, thus providing an indirect strategy for the clinical definition of melancholia.

Adult↗

Twelve-month outcome of nonmelancholic depressive subjects: refinement of subgroups by examination of trajectories.

We previously studied a sample of patients with nonmelancholic depression and attempted to subtype their depression on the basis of etiological factors and current clinical features, analyzed individually and together. We now examine the validity of the three contrasting analytic approaches by examining outcome trajectories in a prospective study. At follow-up we reinterviewed 67% of our initially assessed nonmelancholic subjects, with progress over the 12-month interval assessed across a range of outcome parameters. The "anxious depressed" groups identified across all three differing analytic strategies consistently had the poorest 12-month outcome. However, varying definitions of this group influenced quite differing trajectories, with the worst outcome being for those defined on the basis of clinical features. Study results strongly suggest that patients presenting with a nonmelancholic depressive disorder and who acknowledge a significant number of concurrent anxiety symptoms are likely to have a distinctly poor medium-term outcome. Thus, clinical definition does have predictive utility in such a group.

Affect↗

Subtyping depression by clinical features: the Australasian database.

OBJECTIVE: To distinguish psychotic, melancholic and a residual non-melancholic class on the basis of clinical features alone. Previous studies at our Mood Disorders Unit (MDU) favour a hierarchical model, with the classes able to be distinguished by two specific clinical features, but any such intramural study risks rater bias and requires external replication. METHOD: This replication study involved 27 Australasian psychiatrist raters, thus extending the sample and raters beyond the MDU facility. They collected clinical feature data using a standardized assessment with precoded rating options. A psychotic depression (PD) class was derived by respecting DSM-IV decision rules while a cluster analysis distinguished melancholic (MEL) and non-melancholic classes. RESULTS: The MELs were distinguished virtually entirely by the presence of significant psychomotor disturbance (PMD), as rated by the observationally based CORE measure, with over-representation on only three of an extensive set of 'endogeneity symptoms'. CONCLUSION: In comparison to PMD, endogeneity symptoms appear to be poor indicators of 'melancholic' type, confounding typology with severity. Results again support the hierarchical model.

Adult↗

How long does it take for antidepressant therapies to act?

OBJECTIVE: To review the proposition that antidepressants have a delayed onset of action by employing measurement and analytic strategies that overcome problems confounding interpretation of many efficacy studies. METHOD: A subset of patients was recruited to the longitudinal component of the Australasian database study, was assessed at baseline, and then completed measures of depression and anxiety when treatment commenced, and every 3 days over the next 4 weeks. The trajectories of defined 4-week outcome responders and non-responders were compared. RESULTS: Both groups showed a similar decrease in depression (and anxiety) over the first 3 days. A clear trend break then occurred, with little further improvement in the non-responders, as against distinct and progressive improvement in the responders. Ongoing early improvement (across days 3-6) was a strong predictor of responder status. CONCLUSIONS: The small sample size limits firm interpretation, although distinct interpretive advantages to the study design are evident. Findings are compatible with a number of recent studies arguing against any extensive delayed onset of action for the antidepressant drugs, but argue for caution in interpreting immediate improvement as predicting likely responder status, and more for examining early and sustained improvement as such a marker.

Adult↗

Predictors of 1-year outcome in depression.

OBJECTIVE: We compared several different methods for assessing depression 'recovery' over a 1-year review interval, to determine the utility of the contrasting approaches. Second, we assessed baseline predictors of 1-year outcome and recovery status. Third, we examined the extent to which predictors showed consistency across the variable definitions of outcome and recovery. METHODS: Twelve-month outcome was assessed in a sample of 182 subjects who at baseline assessment met DSM criteria for a major depressive episode. The contrasting methods involved a defined percentage reduction in Beck Depression Inventory self-rating scores, formalised change point definitions, no longer meeting DSM-IV major depression criteria, and clinical global improvement (CGI) ratings. RESULTS: Sixty-one per cent reached formalised change point criteria for full remission or recovery when trajectories across the 12-month interval were examined. Other measures quantified recovery rates ranging from 43% to 70%. Those with a psychotic or melancholic depression were more likely to have achieved recovery status in some analyses. Non-recovery at 12 months was predicted most consistently by higher baseline levels of anxiety and depression; high trait anxiety and a lifetime anxiety disorder; disordered personality function; and having reported exposure to acute and enduring stressors at baseline assessment. CONCLUSIONS: While the CGI was the superior system in terms of number of significant discriminating predictors of outcome, the change point definitional approach provides much greater information across the follow-up interval, arguing for their complementary utility. As several currently identified baseline predictors of outcome (i.e. anxiety, disordered personality function) also predicted onset of depression, their relevance as both depression-inducing and depression-propagating variables is suggested.

Adult↗

Cerebral cryptococcal granuloma in a cat.

A 7-year-old cat was presented for seizures. Cerebrospinal fluid cytology and serology were consistent with a diagnosis of toxoplasmosis. The cat was treated with clindamycin but seizures continued and additional neurological signs developed over 6 months. A mass lesion was identified in the left cerebral hemisphere using magnetic resonance imaging (MRI). The lesion enhanced after gadolidium and a tumour was considered likely. Histologically, the lesion proved to be a cryptococcal granuloma and retrospective serology confirmed that the cat had cryptococcosis at its initial presentation. This report provides the first description in the veterinary literature of the MRI appearance of a cerebral cryptococcoma and emphasises the importance of performing cryptococcal antigen determination in cats with signs of intracranial disease.

Animals↗

Costing depression and its management: an Australian study.

OBJECTIVE: To examine the cost impact of referral to a Mood Disorders Unit (MDU), by comparing pre-service and post-service costs, and MDU and control samples. METHOD: We studied tertiary referral MDU patients and a control group of consultants' depressed patients, with the principal comparison intervals being: (i) 12 months prior to and (ii) 6 months following baseline assessment, with costs annualised to allow the impact of assessment and treatment recommendation to be determined. In addition, we assessed any 'personal cost' of depression. RESULTS: Following baseline assessment, MDU referrals showed a reduction in costs, while controls' costs increased, largely driven by contrasting directions in hospitalisation and social welfare costs. We identify variables associated with high and increased costs, including features of the earlier stages of the disorder, whether social welfare was received, diagnostic subtype and personality dysfunction, with multivariate analyses refining the variable sets. Self-report data indicated that patients judged the 'personal cost' of depression to exceed more formal cost parameters, so that to experience depression is itself depressogenic. CONCLUSIONS: This first Australian attempt to cost depression and its management in the clinical setting more provides a methodology for wider application in service evaluation studies rather than delivers an unequivocal answer to whether a specialist Mood Disorders Unit is cost efficient or not.

Adult↗

A comparative mental health literacy survey of psychiatrists and other mental health professionals in Singapore.

OBJECTIVE: The objectives of this study are, first, to replicate and extend an Australian approach to assessing mental health literacy by studying a sample of Singapore mental health professionals, and to focus on differences between judgements made by the psychiatrists in comparison with the other mental health professionals. Second, to compare the psychiatrists' judgements with those of Australian psychiatrists. METHOD: The Australian questionnaire, assessing responses in relation to vignettes of major depression and to schizophrenia was extended by adding a third vignette of mania, and by the addition of several region-specific response options. Nearly 500 questionnaires were distributed to representative staff (psychiatrists, nurses and allied health) of a large psychiatric institution in Singapore, with a response rate of 81%. Psychiatrists' judgements were compared with all other hospital staff, and with Australian psychiatrists' judgements. RESULTS: The two principal contrast groups (Singapore psychiatrists and other Singapore mental health professionals) differed slightly in terms of diagnostic accuracy. The psychiatrists differed in favouring a more professionally focused model of intervention, while both professional groups viewed traditional healers and their practices as distinctly unhelpful. Direct comparison of psychiatrist ratings generated in Singapore and in Australia revealed quite similar response profiles. CONCLUSIONS: In addition to generating data of some intrinsic importance, comparison with Australian survey data allows the potential impact of regional and cultural differences, as well as of varying psychiatric practices, to be identified. Responses identified more similarities than differences in the judgements of the psychiatrists from the two countries.

Australia↗

Antisense IL-10 abrogates the inhibitory effects of IL-10 production by transfected tumor cells.

Interleukin-10 (IL-10) is a pleiotropic cytokine that has a variety of downregulatory effects on immunologic and inflammatory processes. Ectopic tumor expression of IL-10 inhibited tumor growth, and local administration of antisense IL-10 significantly reversed the effects of IL-10 transfection in P815 mastocytoma. Tissue inhibitors of metalloproteinase (TIMPs) have been associated with decreased tumorigenesis and reduced metastasis, and TIMPs were increased in the region surrounding P815/IL-10 tumors and reduced in antisense IL-10-treated mice. In addition, the antisense IL-10 group had the largest tumor volume and poorest survival when compared with the P815/IL-10 control or sense groups. In summary, our data suggest that, in a mouse model, antisense IL-10 has substantive effects in reducing IL-10 translation and inhibiting IL-10-mediated TIMP upregulation, and, by doing so, allows IL-10-transfected mastocytoma to grow unchecked. Thus, ectopic tumor expression of IL-10 inhibits tumor growth, and antisense IL-10 administration in vivo reverses this protective effect.

Animals↗

Respiratory symptoms and wheat flour exposure: a study of flour millers.

The objective of this study was to determine the prevalence of respiratory symptoms and their relationship to sensitization to wheat flour allergens and fungal amylase, in a group of workers from the UK flour milling industry. A cross-sectional study was used to evaluate symptoms, using a structured interview technique, and sensitization, using skin prick test findings, from 679 employees in flour milling and packing operations at 18 flour mills. A total of 147 workers (147/679, 22%) described upper respiratory tract symptoms of some kind. In the majority (139/147, 95%) these symptoms were of an occasional or transitory nature and were related to short-term exposures to high levels of dust. Three individuals (3/679, 0.4%) were identified whose symptoms were thought to be the result of allergy to wheat flour. The prevalence of positive skin prick tests to wheat flour allergens and to fungal amylase was 1.2% (8/678) and 0.9% (6/678), respectively. Measurements of total inhalable dust exposure for personnel exposed to flour dust were taken at 10 of the sites (116 samples). For production personnel the levels were typically between 1 and 10 mg/m3 (8-h time weighted average), with a median of 6.2 mg/m3. Hygiene operatives had appreciably higher exposure than production personnel, with a median of 18.7 mg/m3. Overall, 43% (50/116) of all samples exceeded 10 mg/m3 (8-h time weighted average). The findings suggest that the risk of sensitization to wheat flour allergens from current dust exposures in flour mills is very low. Wheat allergy was responsible in only a small proportion of the total who had respiratory symptoms. The principal causation of symptoms experienced by the workforce was considered to be a non-specific irritant effect related to short-term exposures to high levels of total inhalable dust.

Amylases↗

Classifying depression: should paradigms lost be regained?

OBJECTIVE: Classification of the depressive disorders has long been controversial. The dominant current model is unitarian, with disorders largely distinguished on the basis of severity. Both the unitarian and the contrasting binarian views (of two principal types) have proved to be unsatisfactory. The binarian model's procrustean requirements are too inflexible to address the evident heterogeneity contributed to by clinical manifestations and underlying personality features. METHOD: This article briefly reviews the historically favored unitarian and binarian viewpoints on classification of depression. RESULTS: The author argues that the "final common pathway" model, articulated in the early 1970s, helped to cement psychiatric classification in subsequent DSM and ICD revisions into a unitarian framework, leading to a relatively sterile period of depression research. Clinically described depressive typologies were obscured rather than refined by appropriate modeling paradigms. A contrasting, empirically based hierarchical model, driven by disorder-specific clinical manifestations such as psychotic features and observable psychomotor disturbance, is proposed as a paradigm for distinguishing psychotic, melancholic, and nonmelancholic classes of depression, while a spectrum model is favored for distinguishing the principal nonmelancholic subclasses. CONCLUSIONS: Resolution of the better paradigm requires that the two models undergo comparative testing in applied studies, particularly ones pursuing neurobiological determinants and differential responses to antidepressant treatments.

Depressive Disorder↗

Best place of care for older people after acute and during subacute illness: a systematic review.

OBJECTIVES: To assess the evaluative research literature on the costs, quality and effectiveness of different locations of care for older patients. METHODS: A systematic review of evaluative research from 1988 using CRD4 guidelines. Twenty-five databases were searched, using processes developed specially for this review. Library OPACS, the Internet and research registers were also searched for relevant material. The final stage of the review was confined to randomised and pseudorandomised trials. Studies were selected for review by pairs of researchers working independently who then met to reach a decision. Analysis was predominantly descriptive; simple pooled odds ratios were used to explore some outcomes. RESULTS: Eighty-four papers from 45 trials were included. Firm conclusions were difficult to draw, except in relation to some outcomes for stroke units, early discharge schemes and geriatric assessment units. Few trials in this area have adequately addressed issues of patients' quality of life and costs to health services, social care providers, patients and their families. CONCLUSIONS: Despite considerable recent development of different forms of care for older patients, evidence about effectiveness and costs is weak. However, evidence is also weak for longer-standing care models. A substantial service evaluation agenda emerges from this review. This study also raises questions about the usefulness of systematic review techniques in the area of service delivery and organisation.

Acute Disease↗

Season of birth in schizophrenia: no latitude at the equator.

BACKGROUND: If the established winter excess in births of people who subsequently develop schizophrenia is an effect of 'seasonality', this would be testable by examining the pattern of births in an equatorial region with no formal seasons. AIMS: To investigate whether there is any variation in month of birth among patients from equatorial Singapore with a diagnosis of schizophrenia. METHOD: All 9655 patients discharged from Singapore's national psychiatric hospital with a diagnosis of schizophrenia were included (year of birth range 1930-1984). We analysed aggregated data, as well as the data of subsamples grouped according to birth-year periods, in order to examine secular trends. One patient subsample (those born 1960-84) allowed exact matching against the general population data set and close testing of any seasonal influence. RESULTS: Monthly variation in births was evident for both patients and controls; the patterns were very similar, apart from the patient sample showing a trough in March-April. CONCLUSIONS: In an equatorial region, where 'seasons' are absent, no seasonal excess in births of those later developing schizophrenia was evident.

Adult↗