Evidence for enemy release in invasive common dace Leuciscus leuciscus in Ireland: a helminth community survey and systematic review.

Invasive species lose parasites in the process of invasion and tend to be less parasitized than conspecifics in the native range and sympatric native species in the invasive range (enemy release). We evaluated enemy release in an invasive freshwater fish in Ireland, common dace Leuciscus leuciscus, using helminth parasite community surveys at the core and front of the invasive range of common dace. Furthermore, we undertook a systematic literature review of helminth infection in common dace across its native range in Great Britain and Europe and invasive range in Ireland. The helminth parasite community survey revealed that invasive common dace were infected with fewer helminth species at the invasion front than at the core. Four helminth taxa - Acanthocephala, Monogenea, Digenea and Nematoda - were present in dace at the invasion core compared to only a single helminth species (Pomphorhynchus tereticollis) at the front. The systematic review revealed that invasive common dace in Ireland hosted fewer species of helminths than common dace in the native range. We report a total of three helminth species in common dace in Ireland compared to 24 in Great Britain and 84 in Continental Europe. Our results support the hypotheses that invasive populations are less parasitized than native populations and that more recently established populations host fewer parasites. However, we demonstrate that invasive species may continue to experience release from parasites long after initial invasion.

Application of frequency-domain Fluorescence Lifetime Imaging Microscopy as a quantitative analytical tool for microfluidic devices.

We describe the application of wide-field frequency domain Fluorescence Lifetime Imaging Microscopy (FLIM) to imaging in microfluidic devices. FLIM is performed using low cost, intensity modulated Light Emitting Diodes (LEDs) for illumination. The use of lifetime imaging for quantitative analysis within such devices is demonstrated by mapping the molecular diffusion of iodide ions across a microchannel.

Relapse and rehospitalization during maintenance treatment of schizophrenia. The effects of dose reduction and family treatment.

BACKGROUND: Previous studies have examined dose reduction and family treatment in schizophrenia, but none has examined their interaction. This study assessed the impact of dose reduction of antipsychotic medication and family treatment on relapse and rehospitalization during maintenance treatment. METHODS: Subjects were 313 male and female outpatients at 5 centers with a DSM-III-R diagnosis of schizophrenia or schizoaffective disorder. In a 3 x 2 design, subjects were randomized to 1 of 3 medication strategies using fluphenazine decanoate under double-blind conditions: continuous moderate dose (standard) (12.5-50 mg every 2 weeks); continuous low dose (2.5-10 mg every 2 weeks); or targeted, early intervention (fluphenazine only when symptomatic). Subjects also were randomized to 1 of 2 family treatment strategies (supportive or applied). Supportive family management involved monthly group meetings. The more intensive applied family management involved monthly group meetings and home visits where communication and problem-solving skills were taught. Patients and families were treated and assessed for 2 years. RESULTS: Both continuous low-dose and targeted treatment increased use of rescue medication and relapse; only targeted treatment increased rehospitalization. This pattern was consistent across both family treatments; there were no differences between family treatments. CONCLUSIONS: These findings reaffirm the value of antipsychotic medication in preventing relapse and rehospitalization. The absence of family treatment differences may be because both conditions engaged families.

The diagnosis of schizophrenia: a review of onset and duration issues.

The diagnosis of schizophrenia remains a topic of continuing dialogue both within the United States and internationally, as witnessed by the numerous revisions to the Diagnostic and Statistical Manual (i.e., DSM-I, DSM-II, DSM-III, and DSM-III-R) and the International Classification of Diseases (i.e., ICD-9, and ICD-10). At issue is how best to characterize patients suffering the debilitating symptoms and chronicity associated with the disease and, at the same time, arrive at a diagnosis that has specific clinical utility and can be reliably assessed. The purpose of the following report is to review three issues associated with the diagnosis of schizophrenia: the role of prodromal and residual symptoms, the duration of psychotic symptoms, and the 6-month versus 1-month time criterion. Our general recommendation, based on extant studies providing data related to various facets of the issues under debate, is to use diagnostic criteria that are consistent with the international diagnostic system. However, final decisions will depend on the outcome of the ongoing DSM-IV field trials.

Diagnosis of schizophrenia: a critical review of current diagnostic systems.

The data relevant to the evaluation of six systems for diagnosing schizophrenia are reviewed. They are summarized in terms of the reliability, predictive validity, specificity, and comprehensiveness of each system. Unfortunately, none, of these systems (Schneider's First-rank Symptoms, New Haven Schizophrenia Index, Flexible System, Feighner Criteria, Research Diagnostic Criteria, and DSM-III) have established construct validity. It is noted therefore that they are all, in a sense, arbitrary. Choosing one over another cannot be data-based. Because the elevation of any one diagnostic system to an official status is thought to be premature, clinicians and researchers alike are advised to exercise caution and openmindedness in their use of DSM-III. There is as yet no evidence that its criteria for schizophrenia are either less arbitrary or better (in identifying a group of "true" schizophrenics) than those of other systems or DSM-II.

First-episode psychosis: Part I. Editors' introduction.

Until recently, there has been a conspicuous lack of studies regarding the earliest phases of psychotic illness, with most research on schizophrenia and related disorders focusing on chronically ill patients. Currently, however, a number of investigators have turned their attention toward this topic, exploring the conceptual issues involved in defining the onset of psychosis, using case registers and population-based samples to do crucial epidemiologic studies on the course of schizophrenia, and developing mechanisms for identifying patients with first-episode psychosis and entering them into active research protocols. The issue of the Schizophrenia Bulletin is devoted to articles representing this full range of conceptual and empirical work on first-episode psychosis. The ultimate goal is for researchers working in this area to develop a network to enhance the sharing of concepts and data, with the eventual possibility of developing combined data bases and collaborative studies.

Research on first-episode psychosis: report on a National Institute of Mental Health Workshop.

The need to focus increased research on patients experiencing their first episode of psychosis was emphasized in A National Plan for Schizophrenia Research. To develop strategies for enhancing research in this area, a National Institute of Mental Health Workshop on First-Episode Psychosis was held in 1991. The topics discussed at that workshop are summarized, with key issues including the following: (1) the need for better operational definitions of onset, end of an episode, and relapse of psychosis; (2) careful consideration of inclusion and exclusion criteria related to age, gender, prior treatment, comorbid substance abuse, and similar issues; (3) the challenge of finding patients never exposed to neuroleptics and the value of entering first-episode patients into standardized treatment protocols; (4) the design of followup studies; (5) strategies to increase the pool of applicants; and (6) approaches for increasing power through data sharing and collaboration between groups.

A non-neuroleptic treatment for schizophrenia: analysis of the two-year postdischarge risk of relapse.

The efficacy of antipsychotic drug maintenance in reducing the risk of relapse among previously hospitalized schizophrenic patients has been well documented. However, data from an ongoing study comparing two cohorts of young first admission schizophrenics--one receiving neuroleptic-oriented treatment on the wards of a community mental health center (CMHC), the other an intensive interpersonal approach in a small homelike facility in the community (Soteria House)--raise questions about the routine use of neuroleptics with this population. Our questioning of this practice is based on data analyzed from these two cohorts by means of the life table, a statistical technique appropriate for longitudinal studies. Data are presented in two ways: (1) The overall effectiveness of the two independent treatment programs (Soteria, N = 32, vs. CMHC, N = 36) is compared in terms of the probabilities of not being readmitted over the 2-year postdischarge interval. (2) Analyses that look at the influence of the original treatment setting and postdischarge antipsychotic drug status on readmission rates are presented. Program comparisons reveal Soteria patients to have a consistently higher survival rate than CMHC patients throughout 2 years postdischarge. At 12 months postdischarge, the cumulative probability of remaining well (no readmissions) significantly favors the Soteria patients (p less than .05, Mantel chi2). The overall results of the Soteria program were achieved despite the fact that all CMHC patients received neuroleptics during their original inpatient stays and about 50 percent were maintained on neuroleptics up to the point of readmission or study termination, whereas only 10 percent of Soteria subjects were treated with or maintained on neuroleptics. The survival rates by postdischarge drug status and program affiliation show the Soteria no-drug group to have the highest proportion of survivors at almost every interval throughout 24 months, the CMHC drug-maintained group to have the lowest survival rate, and the CMHC unmaintained group to be surviving at a rate generally comparable to the Soteria no-drug group.

Definition of 15 equine leucocyte antigens.

Fifteen equine leucocyte antigens were defined by absorption and titration analysis of alloantisera obtained by natural sensitisation through pregnancy and by planned experimental immunisation. Definitive sera were tested on the cells of 90 unrelated horses and members of eight equine families. The family data suggested that 13 specificities were coded by a single locus (first locus) and one specificity (Eq 14) was coded by a second linked locus. The remaining specificity (Eq 7) was controlled by a third locus unlinked to the first or second loci. Tests on the cells of unrelated horses showed that two first locus specificities (Eq 16 and Eq 17) had a supertypic relationship to other first locus antigens. No individual was found to possess more than two first locus antigens, excluding the supertypic specificities.

Equine leucocyte antigen system: progress and potential.

Leucocyte antigens are cell-surface glycoproteins, the structure of which is under the genetic control of a chromosome region called the major histocompatibility complex. Progress in the study of the equine leucocyte antigen (ELA) system has been achieved in two ways; first by the fact that the ELA system is intensively investigated in different laboratories all over the world and parallels can be drawn to the information gained from research in more extensively studied species, and secondly by the collaborative efforts of the participants in three international workshops. The potential applications of the ELA system and areas of further investigation are discussed.

Chemical arthrodesis of the distal tarsal joints using sodium monoiodoacetate in 104 horses.

OBJECTIVE: To evaluate chemical arthrodesis using sodium monoiodoacetate for treatment of degenerative joint disease of the tarsometatarsal and distal intertarsal joints. DESIGN: Retrospective clinical study. METHOD: Horses were diagnosed with degenerative joint disease of one or more of the tarsometatarsal or distal intertarsal joints based on history, lameness examination, radiographic findings and, in some cases, response to intra-articular anaesthesia or medication. Intra-articular injections of sodium monoiodoacetate were performed using 23 gauge needles in the sedated, standing horse. Positive contrast arthrography of the distal intertarsal joint was performed in all horses to evaluate needle placement and the presence or absence of communication with other synovial structures. The mean intra-articular dose of sodium monoiodoacetate was 192 mg. Horses were subject to a graded exercise program commencing 7 to 10 days after treatment. Where possible, follow up lameness examination and radiography was performed at 3, 6, 12 and 24 months after treatment. RESULTS: At 3, 6, 12 and 24 months after treatment, respectively, 0/57, 14/55, 41/50, and 29/34 of horses were sound. At 3, 6, 12 and 24 months after treatment, respectively, 5/55, 24/38, 26/30 and 18/18 of horses had radiographic evidence of ankylosis of treated joints. Post injection pain was marked in 6.7% of horses and significant complications requiring further treatment occurred in 3.8% of horses. CONCLUSIONS: Chemical arthrodesis using sodium monoiodoacetate was an effective treatment method for degenerative joint disease of the distal tarsal joints. The technique was performed in the sedated standing horse and required minimal equipment. Results were comparable to those achieved following surgical arthrodesis. The risk of significant complications was minimised through good technique using an appropriate injection volume and concentration.

Refolding of a membrane protein in a microfluidics reactor.

Membrane protein production for structural studies is often hindered by the formation of non-specific aggregates from which the protein has to be denatured and then refolded to a functional state. We developed a new approach, which uses microfluidics channels, to refold protein correctly in quantities sufficient for structural studies. Green fluorescent protein (GFP), a soluble protein, and bacteriorhodopsin (BR), a transmembrane protein, were used to demonstrate the efficiency of the process. Urea-denatured GFP refolded as the urea diffused away from the protein, forming in the channel a uniform fluorescent band when observed by confocal microscopy. Sodium dodecyl sulphate-denatured BR refolded within the channel on mixing with detergent-lipid mixed micelles. The refolding, monitored by absorbance spectroscopy, was found to be flow rate dependent. This potential of microfluidic reactors for screening protein-folding conditions and producing protein would be particularly amenable for high-throughput applications required in structural genomics.

Delta9-tetrahydrocannabinol stimulates palatable food intake in Lewis rats: effects of peripheral and central administration.

To further study effects of delta9-tetrahydrocannabinol (THC) on food intake, male Lewis rats were maintained on rat chow and, on testing days, presented with chocolate cake batter (CCB) for 4h in addition to chow. Chow intake was not affected by THC administration in either experiment. In experiment 1 (n = 13) THC was administered intraperitoneally, and low doses produced increases in CCB intake for up to 1 h while the highest dose significantly decreased CCB intake over this same time period. In experiment 2 (n = 10) THC was injected intracerebroventricularly. Doses of 2.5, 10 and 25 microg significantly increased CCB intake for up to 1 h while stimulatory effects following 5 microg lasted up to 2h. Overall THC produced short-term increases in palatable food intake following both peripheral and central administration. Intraperitoneal administration resulted in an "inverted U" dose-response curve at all time points, while all central doses resulted in increased intake early in the time course and the hyperphagic effects were of greater duration than those following peripheral administration.

Primary prevention of asthma and atopy during childhood by allergen avoidance in infancy: a randomised controlled study.

BACKGROUND: Recent increases in the prevalence of asthma and atopy emphasise the need for devising effective methods for primary prevention in children at high risk of atopy. METHOD: A birth cohort of genetically at risk infants was recruited in 1990 to a randomised controlled study. Allergen avoidance measures were instituted from birth in the prophylactic group (n=58). Infants were either breast fed with mother on a low allergen diet or given an extensively hydrolysed formula. Exposure to house dust mite was reduced by the use of an acaricide and mattress covers. The control group (n=62) followed standard advice as normally given by the health visitors. At age 8, all 120 children completed a questionnaire and 110 (92%) had all assessments (skin prick test, spirometry, and bronchial challenges). RESULTS: In the prophylactic group eight children (13.8%) had current wheeze compared with 17 (27.4%) in the control group (p=0.08). Respective figures were eight (13.8%) and 20 (32.3%) for nocturnal cough (p=0.02) and 11 of 55 (20.0%) and 29 of 62 (46.8%) for atopy (p=0.003). After adjusting for confounding variables, the prophylactic group was found to be at a significantly reduced risk for current wheeze (odds ratio (OR) 0.26 (95% confidence interval (CI) 0.07 to 0.96)), nocturnal cough (OR 0.22 (95% CI 0.06 to 0.83)), asthma as defined by wheeze and bronchial hyperresponsiveness (OR 0.11 (95% CI 0.01 to 1.02)), and atopy (OR 0.21 (95% CI 0.07 to 0.62)). CONCLUSION: Strict allergen avoidance in infancy in high risk children reduces the development of allergic sensitisation to house dust mite. Our results suggest that this may prevent some cases of childhood asthma.

No correlation between nigral degeneration and striatal plaques in Alzheimer's disease.

Although Alzheimer's disease may involve both the substantia nigra and the striatum, there is little information concerning the relationship between the resulting abnormalities in these reciprocally interconnected regions of the brain. We have examined the correlation between plaque density in the striatum and counts of neurons and neurofibrillary tangles in the pars compacta of the substantia nigra, in 12 cases of "pure" Alzheimer's disease (i.e. without clinical or neuropathological evidence of Parkinson's or cortical Lewy body disease) and 11 normal controls. Diffuse plaques in the striatum and neurofibrillary tangles in the substantia nigra were consistent findings in all of the Alzheimer brains. However, quantitation did not reveal a statistically significant correlation between the density of striatal plaques and the numbers of either neurofibrillary tangles or neurons in the substantia nigra. Although the mean number of neurons in the substantia nigra of Alzheimer brains was lower than that in controls, the difference did not reach statistical significance. We suggest that previous assessments of substantial loss of nigral neurons in Alzheimer's disease may have been skewed by the inclusion of cases with coexistent cortical Lewy bodies.

Changes in blood ammonia, lactate and amino acids in relation to workload during bicycle ergometer exercise in man.

Whole body exercise at intensities up top 50% VO2max has no effect on the concentration of blood ammonia but a threefold rise in blood ammonia is observed at workloads up to maximal. There is a linear relationship between blood ammonia and lactate production during exercise which suggests that the two processes may be linked to a common process of short-term energy provision. Blood glutamine and blood alanine both show rises linearly related to power output during exercise, suggesting that if these amino acids are sinks for ammonia then the process of ammonia incorporation is saturated at high workloads.

Comparison of three silver stains for demonstrating neurofibrillary tangles and neuritic plaques in brain tissue stored for long periods.

Three methods were compared to find a reliable method for demonstrating neurofibrillary tangles (NFTs) and neuritic plaques (NPs) in brain tissue stored for long periods in formalin or as paraffin blocks. The short-term fixation of tissue, e.g. up to 6 months in formalin does not usually present a problem using any of the three methods tried, e.g. Gallyas, modified Palmgren, or modified Bielschowsky, but once the time lengthens to 6 years or more the demonstration of NFTs and NPs is not so reliable using the first two methods. The modified Bielschowsky method, however, demonstrates well both NFTs and NPs in material stored in formalin or as paraffin blocks for long periods, e.g. 7 years, and also compares favourably with the other methods on freshly processed material and fixed tissue, stored for shorter periods. We also noted as a consistent trend, irrespective of the staining technique employed, the detection of fewer plaques and tangles in material stored in formalin, as opposed to that stored as blocks embeded in paraffin wax.

A team approach to pharmacologic treatment of chronic schizophrenia.

The authors describe a therapeutic approach to the pharmacologic treatment of the schizophrenic patient. This team approach relies on interaction between the patient, the patient's family, and the clinician, and helps to eliminate blaming behavior that often demoralizes all parties involved. The authors maintain that neuroleptic therapy can control the positive symptoms of schizophrenia. However, they point out that neuroleptics may cause side effects and may interfere with improvement in negative symptoms and interpersonal relationships. The authors suggest that reduced-dosage strategies may prove the most effective way to prevent relapse, while minimizing the side effects of neuroleptics.

Maintenance treatment of schizophrenia: a review of dose reduction and family treatment strategies.

Maintenance treatment in schizophrenia requires the integration of both medication and psychosocial treatment interventions for maximum effect. We review the recent evidence for strategies drawn from both domains. For the use of anti-psychotic medication we focus on studies of dose reduction using two strategies that differ in assumptions regarding the action of medication. They are: continuous low-dose and targeted, early intervention or intermittent treatment. For psychosocial interventions we focus on studies of family treatment. Regarding dose reduction, we conclude that both strategies are feasible but the targeted strategy incurs higher relapse and rehospitalization rates. Regarding family treatment, we conclude that family treatment provides benefits beyond other psychosocial interventions or usual care, but that there is no evidence for differences in efficacy among family treatments.