Helminth parasite communities of the water-rat, Hydromys chrysogaster, from Queensland

The helminth fauna from 124 water-rats, Hydromys chrysogaster, collected from 33 localities in Queensland was analysed. A total of 45 species of helminths was found, comprising 2 acanthocephalans, 2 cestodes, 13 nematodes and 28 trematodes. The helminth community of the water-rats in the region north of latitude 18 degrees (far north) was different from that of water-rats south of 18 degrees (central); Sorensen's Index 45.8% similarity, whereas Holmes and Podesta's Index gave 32.1% similarity. Comparisons with data from water-rats from southern and Tasmanian regions showed that they were different from each other and from both Queensland regions. The helminth communities were characterised by high diversity, dominated by trematodes in the central and Tasmanian regions, but with nematodes becoming more prominent in the far northern and southern regions. No core or secondary species were found in the Queensland helminth communities, the southern community was suggestive of a bimodal distribution and the Tasmanian had two core species. A checklist of helminth species occurring in water-rats from eastern Australia is provided.

Combined external-endonasal approach for complete excision of the lacrimal drainage apparatus

Purpose: The purpose of this study was to describe a new surgical technique for the complete excision of the lacrimal drainage apparatus (LDA) that combines external and endoscopic approaches. Methods: This study involved a noncomparative, retrospective chart review of the clinical and pathological findings of four patients presenting with LDA papillomas who underwent a combined open and endonasal excision of the lacrimal system. Results. Of the four patients, three were male. The mean age at referral was 41 years, and all cases were unilateral. Histopathology revealed two transitional cell papillomas, one squamous cell papilloma, and one combined transitional/squamous papilloma. Epiphora and an external lesion were the main complaints at presentation. Nasolacrimal duct obstruction was present in all four patients. Papilloma virus infection was suggested in two cases and was confirmed in the only patient who had recurrence. CT identified a solid enhancing mass in two cases. The surgical approach in all cases was performed with the patient under general anesthetic supplemented with infiltration of local anesthesia with vasoconstriction. The lacrimal sac was exposed as per an external dacryocystorhinostomy with biopsy collection from the lacrimal sac lumen to confirm the diagnosis prior LDA excision. The superior aspect of the LDA was isolated by using lacrimal probes in each canaliculus to stabilized parallel incisions and careful dissection toward the common canaliculus until they met the medial aspect of the lacrimal sac. The sac was then separated from the periosteum from the medial orbital wall, using sharp dissection. Finally, an endoscopic dissection of the lower end of the nasolacrimal duct released the most inferior aspect of the LDA, allowing the surgeon to pull and excise the complete system from the external wound. Conclusions: Extensive LDA papillomas required complete excision of the drainage system to prevent recurrence and/or malignant transformation. The use of a combined approach through an open excision of the superior part of the LDA in conjunction with the direct manipulation of the nasolacrimal duct guided by the nasal endoscope facilitates the complete excision of the system for extensive benign lesions.

An exploration of varieties of visual attention: ERP findings

A set of five tasks was designed to examine dynamic aspects of visual attention: selective attention to color, selective attention to pattern, dividing and switching attention between color and pattern, and selective attention to pattern with changing target. These varieties of visual attention were examined using the same set of stimuli under different instruction sets; thus differences between tasks cannot be attributed to differences in the perceptual features of the stimuli. ERP data are presented for each of these tasks. A within-task analysis of different stimulus types varying in similarity to the attended target feature revealed that an early frontal selection positivity (FSP) was evident in selective attention tasks, regardless of whether color was the attended feature. The scalp distribution of a later posterior selection negativity (SN) was affected by whether the attended feature was color or pattern. The SN was largely unaffected by dividing attention across color and pattern. A large widespread positivity was evident in most conditions, consisting of at least three subcomponents which were differentially affected by the attention conditions. These findings are discussed in relation to prior research and the time course of visual attention processes in the brain. (C) 1999 Elsevier Science B.V. All rights reserved.

Perceived need for mental health care, findings from the Australian National Survey of Mental Health and Well-being

Background. The Australian National Survey of Mental Health and Well-being was designed to detect and describe psychiatric morbidity, associated disability, service use and perceived need for care. The survey employed a single-phase interview methodology, delivering a field questionnaire to a clustered probability sample of 10641 Australians. Perceived need was sampled with an instrument designed for this survey, the Perceived Need for Care Questionnaire (PNCQ). This questionnaire gathers information about five categories of perceived need, assigning each to one of four levels of perceived need. Reliability and validity studies showed satisfactory performance of the instrument. Methods. Perceived need for mental health care in the Australian population has been analysed using PNCQ data, relating this to diagnostic and service utilization data from the above survey. Results. The survey findings indicate that an estimated 13.8 % of the Australian population have perceived need for mental health care. Those who met interview criteria for a psychiatric diagnosis and also expressed perceived need make up 9.9 % of the population. An estimated 11.0% of the population are cases of untreated prevalence, a minority (3.6% of the population) of whom expressed perceived need for mental health care. Among persons using services, those without a psychiatric diagnosis based on interview criteria (4.4% of the population), showed high levels of perceived met need. Conclusions. The overall rate of perceived need found by this methodology lies between those found in the USA and Canada. The findings suggest that service use in the absence of diagnosis elicited by survey questionnaires may often represent successful intervention. In the survey, untreated prevalence was commonly not accompanied by perceived need for mental health care.

Post-traumatic stress disorder: Findings from the Australian National Survey of Mental Health and Well-being

Background. We report on the epidemiology of post-traumatic stress disorder (PTSD) in the Australian community, including information on lifetime exposure to trauma, 12-month prevalence of PTSD, sociodemographic correlates and co-morbidity. Methods. Data were obtained from a stratified sample of 10641 participants as part of the Australian National Survey of Mental Health and Well-being. A modified version of the Composite International Diagnostic Interview was used to determine the presence of PTSD, as well as other DSM-IV anxiety, affective and substance use disorders. Results. The estimated 12-month prevalence of PTSD was 1.33%, which is considerably lower than that found in comparable North American studies. Although females were at greater risk than males within the subsample of those who had experienced trauma, the large gender differences noted in some recent epidemiological research were not replicated. Prevalence was elevated among the never married and previously married respondents, and was lower among those aged over 55. For both men and women, rape and sexual molestation were the traumatic events most likely to be associated with PTSD. A high level of Axis I co-morbidity was found among those persons with PTSD Conclusions. PTSD is a highly prevalent disorder in the Australian community and is routinely associated with high rates of anxiety, depression and substance disorders. Future research is needed to investigate rates among other populations outside the North American continent.

Paternal age as a risk factor for psychosis and schizophrenia: Findings from Denmark, Sweden and Australia

The offspringof older fathers have an increased risk of various disorders that may be due to the accumulation of DNA mutations during spermatogenesis. Previous studies have suggested increased paternal age may be a risk factor for schizophrenia. The aim of the current study was to examine paternal age as a risk factor for schizophrenia andror psychosis. We used data from three sources: a population-based cohort studyŽDenmark., and two case-control studiesŽSweden and Australia.. In the Danish and Australian studies, we examined both psychosis and schizophrenia. In the Swedish study we examined psychosis only. After controllingfor the effect of maternal age, increased paternal age was significantly associated with increased risk of both psychosis and schizophrenia in the Danish study and of psychosis in the Swedish study. The Australian study found no association between paternal age and risk of psychosis or schizophrenia. In all three studies the relationship between paternal age and risk of disorder in the offspring was AUB-shaped. In addition to an increased risk for the offspringof older father Ž)35 years., there was a non-significant increase for the offspringof fathers aged less than 20 years. The possible role of paternally derived DNA mutations andror other psychosocial factors associated with older paternal age warrants further research. The ‘U’-shaped relationship suggests that factors other than DNA mutations may warrant consideration in this research. The Stanley Foundation supported this project.