Alternatives assessment: An analysis on progress and future needs for research and practice

Alternatives assessment is a science-policy approach to support the informed substitution of chemicals of concern in consumer products and industries, with the intent of avoiding regrettable substitution and facilitating the transition to safer, more sustainable chemicals and products. The field of alternatives assessment has grown steadily in recent decades, particularly after the publication of specific frameworks and the inclusion of substitution and alternatives assessment requirements in a number of policy contexts. Previously, 14 research and practice needs for the field were outlined across five critical areas: comparative hazard assessment, comparative exposure characterization, lifecycle considerations, decision-making and decision analysis, and professional practice. The aim of the current article is twofold: to highlight methodological advances in the growing field of alternatives assessment based on identified research and practice needs and to propose areas for future developments. We assess advances in the field based on the analysis of a broad literature review that captured 154 sources published from 2013 to 2022. The results indicate that research conducted advanced many of the needs identified, but several remain underaddressed. Although the field has clearly grown and taken root over the past decade, there are still research and practice gaps, most notably on the hazard assessment of mixtures or different forms of chemicals, the integration of lifecycle considerations, and the development of practical approaches to address trade-offs in decision-making. We propose modifications to four of the prior research and practice needs in addition to new needs, including the development of standardized hazard assessment approaches for chemical mixtures as well as better integration of equity and/or justice considerations into assessments. Integr Environ Assess Manag 2024;00:1-18. © 2023 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC).

Dietary exposure to the food preservative tert-Butylhydroquinone (tBHQ) impairs zebrafish (Danio rerio) survival, growth, organ development, and gene expression in Nrf2a-dependent and independent ways

Tert-Butylhydroquinone (tBHQ), a preservative used to prevent oxidative deterioration of oil, fat, and meat products, has been linked to both chemoprotective and adverse effects. This study investigates the impact of dietary tBHQ consumption on survival, growth parameters, organ development, and gene expression in zebrafish (Danio rerio). As tBHQ activates the transcription factor nuclear factor erythroid 2-related factor 2 (Nrf2a), a zebrafish line with a mutation in the DNA-binding domain of Nrf2a was used to identify Nrf2a-dependent vs independent effects. Homozygous Nrf2a wildtype (wt) and mutant (m) larvae were fed a diet containing 5% tBHQ or a control diet. Survival and growth parameters were assessed at 15 days and at 5 months, and samples were collected for RNA sequencing at 5 months. Dietary exposure to tBHQ throughout the larval and juvenile periods negatively impacted growth and survival. RNA-seq analysis found differentially expressed genes related to growth and development and upregulation of several immune system-related pathways. The findings herein demonstrate that dietary tBHQ exposure may impair growth and survival in both Nrf2a dependent and independent manners.

The Zebrafish (Danio rerio) Embryo Model as a Tool to Assess Drinking Water Treatment Efficacy for Freshwater Impacted by Crude Oil Spill

Traditional approaches toward evaluating oil spill mitigation effectiveness in drinking water supplies using analytical chemistry can overlook residual hydrocarbons and treatment byproducts of unknown toxicity. Zebrafish (Danio rerio) were used to address this limitation by evaluating the reduction in toxicity to fish exposed to laboratory solutions of dissolved crude oil constituents treated with 3 mg/L ozone (O₃ ) with or without a peroxone-based advanced oxidation process using 0.5 M H₂ O₂ /M O₃ or 1 M H₂ O₂ /M O₃ . Crude oil water mixtures (OWMs) were generated using three mixing protocols-orbital (OWM-Orb), rapid (OWM-Rap), and impeller (OWM-Imp) and contained dissolved total aromatic concentrations of 106-1019 µg/L. In a first experiment, embryos were exposed at 24 h post fertilization (hpf) to OWM-Orb or OWM-Rap diluted to 25%-50% of full-strength samples and in a second experiment, to untreated or treated OWM-Imp mixtures at 50% dilutions. Toxicity profiles included body length, pericardial area, and swim bladder inflation, and these varied depending on the OWM preparation, with OWM-Rap resulting in the most toxicity, followed by OWM-Imp and then OWM-Orb. Zebrafish exposed to a 50% dilution of OWM-Imp resulted in 6% shorter body length, 83% increased pericardial area, and no swim bladder inflation, but exposure to a 50% dilution of OWM-Imp treated with O₃ alone or with 0.5 M H₂ O₂ /M O₃ resulted in normal zebrafish development and average total aromatic destruction of 54%-57%. Additional aromatic removal occurred with O₃  + 1 M H₂ O₂ /M O₃ but without further attenuation of toxicity to zebrafish. This study demonstrates using zebrafish as an additional evaluation component for modeling the effectiveness of freshwater oil spill treatment methods. Environ Toxicol Chem 2022;41:2822-2834. © 2022 SETAC.

Nrf2a dependent and independent effects of early life exposure to 3,3'-dichlorobiphenyl (PCB-11) in zebrafish (Danio rerio)

The environmental pollutant 3,3'-dichlorobiphenyl (PCB-11) is a lower-chlorinated polychlorinated biphenyl (PCB) congener present in air and water samples. Both PCB-11 and its metabolite, 4-PCB-11-Sulfate, are detected in humans, including in pregnant women. Previous research in zebrafish (Danio rerio) has shown that 0.2 μM exposures to 4-PCB-11-Sulfate starting at 1 day post fertilization (dpf) increase hepatic neutral lipid accumulation in larvae at 15 dpf. Here, we explored whether nuclear factor erythroid 2-related factor 2 (Nrf2), known as the master-regulator of the adaptive response to oxidative stress, contributes to metabolic impacts of 4-PCB-11-Sulfate. For this work, embryos were collected from homozygous wildtype or Nrf2a mutant adult zebrafish that also express GFP in pancreatic β-cells, rendering Tg(ins:GFP;nrf2a^fh318+/+) and Tg(ins:GFP;nrf2a^fh318-/-) lines. Exposures were conducted from 1-15 dpf to either 0.05% DMSO or DMSO-matched 0.2 µM 4-PCB-11-Sulfate, and at 15 dpf subsets of larvae were imaged for overall morphology, primary pancreatic islet area, and collected for fatty acid profiling and RNAseq. At 15 dpf, independent of genotype, fish exposed to 4-PCB-11-Sulfate survived significantly more at 80-85% compared to 65-73% survival for unexposed fish, and had primary pancreatic islets 8% larger compared to unexposed fish. Fish growth at 15 dpf was dependent on genotype, with Nrf2a mutant fish a significant 3-5% shorter than wildtype fish, and an interaction effect was observed where Nrf2a mutant fish exposed to 4-PCB-11-Sulfate experienced a significant 29% decrease in the omega-3 fatty acid DHA compared to unexposed mutant fish. RNAseq revealed 308 differentially expressed genes, most of which were dependent on genotype. These findings suggest that Nrf2a plays an important role in growth as well as for DHA production in the presence of 4-PCB-11-Sulfate. Further research would be beneficial to understand the importance of Nrf2a throughout the lifecourse, especially in the context of toxicant exposures.

Dibenzyl trisulfide binds to and competitively inhibits the cytochrome P450 1A1 active site without impacting the expression of the aryl hydrocarbon receptor

The toxicological manifestation of many pollutants relies upon their binding to the aryl hydrocarbon receptor (AHR), and it follows a cascade of reactions culminating in an elevated expression of cytochrome P450 (CYP) 1 enzymes. CYP1A1 and CYP1B1 are associated with enhanced carcinogenesis when chronically exposed to certain polyaromatic hydrocarbons, and their inhibition may lead to chemoprevention. We evaluated dibenzyl trisulfide (DTS), expressed in the ethnomedical plant, Petiveria alliacea, for such potential chemoprevention. Using recombinant human CYP1A1 and CYP1B1 bactosomes on a fluorogenic assay, we first demonstrated that DTS moderately inhibited both enzymes with half maximal inhibitory concentration (IC50) values of 1.3 ± 0.3 and 1.7 ± 0.3 μM, respectively. Against CYP1A1, DTS was a reversible, competitive inhibitor with an apparent inhibitory constant (Ki) of 4.55 ± 0.37 μM. In silico molecular modeling showed that DTS binds with an affinity of -39.8 kJ·mol-1, situated inside the binding pocket, approximately 4.3 Å away from the heme group, exhibiting interactions with phenylalanine residue 123 (Phe-123), Phe-224, and Phe-258. Lastly, zebrafish (Danio rerio) embryos were exposed to 0.08-0.8 μM DTS from 24 to 96 h post fertilization (hpf) with the in vivo ethoxyresorufin-O-deethylase (EROD) assay, and, at 96 hpf, DTS significantly suppressed EROD CYP1A activity in a dose-dependent manner, with up to 60% suppression in the highest 0.8 μM exposure group. DTS had no impact on gene transcription levels for cyp1a and aryl hydrocarbon receptor 2 (ahr2). In co-exposure experiments, DTS suppressed CYP1A activity induced by both B[a]P and PCB-126, although these reductions were not significant. Taken together, these results demonstrate that DTS is a direct, reversible, competitive inhibitor of the carcinogen-activating CYP1A enzyme, binding in the active site pocket close to the heme site, and shows potential in chemoprevention.

The sulfate metabolite of 3,3'-dichlorobiphenyl (PCB-11) impairs Cyp1a activity and increases hepatic neutral lipids in zebrafish larvae (Danio rerio)

The environmental contaminant 3,3'-dichlorobiphenyl (PCB-11) is widely detected in environmental samples, and this parent compound along with its metabolites 4-OH-PCB-11 and 4-PCB-11-Sulfate are detected in human serum. Our previous research in zebrafish (Danio rerio) embryos shows exposure to 20 μM PCB-11 inhibits Cyp1a enzyme activity and perturbs lipid metabolism pathways. In this study, wildtype AB embryos underwent acute exposures from 1 to 4 days post fertilization (dpf) to 0.002-20 μM 4-OH-PCB-11 or 0.2-20 μM 4-PCB-11-Sulfate, with and without co-exposures to 100 μg/L benzo[a]pyrene (B[a]P) or 5 nM 3,3',4,4',5-pentachlorobiphenyl (PCB-126), and were assessed for in vivo EROD activity and morphometrics. Chronic exposures from 1 to 15 dpf to assess lipid accumulation using Oil-Red-O staining were also conducted with 0.2 μM parent or metabolite compounds, alongside a co-exposure experiment of 0.002-0.2 μM 4-PCB-11-Sulfate and 10 μg/L B[a]P. For acute experiments, 2 and 20 μM 4-OH-PCB-11 was lethal but no Cyp1a or morphological effects were observed at lower concentrations; 20 μM 4-PCB-11-Sulfate significantly lowered the Cyp1a activity of B[a]P and PCB-126 but did not alter morphological development. For chronic experiments, 0.2 μM 4-PCB-11-Sulfate significantly increased lipid accumulation 30% in single exposures and 44% in co-exposures with B[a]P. Further long-term studies would better elucidate the effects of this contaminant, particularly in the context of environmentally-relevant mixtures.

Chemical Characterization of a Legacy Aqueous Film-Forming Foam Sample and Developmental Toxicity in Zebrafish (Danio rerio)

BACKGROUND

Drinking water contamination related to the use of aqueous film-forming foam (AFFF) has been documented at hundreds of military bases, airports, and firefighter training facilities. AFFF has historically contained high levels of long-chain per- and polyfluoroalkyl substances (PFAS), which pose serious health concerns. However, the composition and toxicity of legacy AFFF mixtures are unknown, presenting great uncertainties in risk assessment and affected communities.

OBJECTIVES

This study aimed to determine the fluorinated and nonfluorinated chemical composition of a legacy AFFF sample and its toxicity in zebrafish embryos.

METHODS

A sample of legacy AFFF (3% application formulation, manufactured before 2001) was provided by the Massachusetts Department of Environmental Protection. High resolution mass spectrometry (HRMS) was used to identify PFAS and nonfluorinated compounds, and a commercial laboratory measured 24 PFAS by a modified U.S. EPA Method 537.1. AFFF toxicity was assessed in zebrafish embryos in comparison with four major constituents: perfluorooctanesulfonic acid (PFOS); perfluorohexanesulfonic acid (PFHxS); sodium dodecyl sulfate (SDS); and sodium tetradecyl sulfate (TDS). End points included LC 50 values, and sublethal effects on growth, yolk utilization, and pancreas and liver development.

RESULTS

We identified more than 100 PFAS. Of the PFAS detected, PFOS was measured at the highest concentration (9,410 mg / L ) followed by PFHxS (1,500 mg / L ). Fourteen nonfluorinated compounds were identified with dodecyl sulfate and tetradecyl sulfate the most abundant at 547.8 and 496.4 mg / L , respectively. An LC 50 of 7.41 × 10 - 4 % AFFF was calculated, representing a dilution of the 3% formulation. TDS was the most toxic of the constituents tested but could not predict the AFFF phenotype in larval zebrafish. PFOS exposure recapitulated the reduction in length but could not predict effects on development of the liver, which was the tissue most sensitive to AFFF.

DISCUSSION

To our knowledge, this research is the first characterization of the chemical composition and toxicity of legacy AFFF, which has important implications for regulatory toxicology. https://doi.org/10.1289/EHP6470.

Community outreach workers: Perceived practices and impacts on families and young children

Background

Community outreach workers support individuals accessing healthcare and other services that could be useful to respond to their needs. Even though community outreach workers have been working in the province of Quebec (Canada) for the past 40 years, their practice is poorly documented and evaluated, especially with respect to young children aged 0 to 5 years. This study aimed to document the practice of community outreach workers and its perceived impacts among children and families.

Methods

A qualitative methodology with a descriptive research design was used. We performed a content analysis on 55 scientific and grey literature documents, 24 individual interviews, and 3 focus groups with stakeholders including parents, community outreach workers, healthcare employees, and inter-sectoral partners.

Results

Our analysis reveals three main themes: 1) characteristics of the population served, 2) concrete actions performed by community outreach workers, and 3) perceived impacts of community outreach on families and children. Community outreach workers were perceived as essential to reach families with vulnerable circumstances and children with special needs. With respect to concrete actions, community outreach workers were reported to tailor their interventions to respond in different but complementary ways to the healthcare system. Perceived impacts included increased access for children and families to appropriate services, decreased social isolation, increased empowerment (especially with respect to parental abilities), increased social capital of families, and confidence towards the healthcare system. Results showed that community outreach workers helped to reduce inequalities in health

Conclusions

Community outreach work help the healthcare system to fulfill its legal mandate to protect citizen and increase health and well-being. It is crucial that such type of proximity approaches be not only encouraged but also sustained.

Key messages

Community outreach workers adapt their practices to act in a complementary way to the healthcare system. Community outreach workers help to reduce inequalities in health.

The emerging contaminant 3,3'-dichlorobiphenyl (PCB-11) impedes Ahr activation and Cyp1a activity to modify embryotoxicity of Ahr ligands in the zebrafish embryo model (Danio rerio)

3,3'-dichlorobiphenyl (PCB-11) is an emerging PCB congener widely detected in environmental samples and human serum, but its toxicity potential is poorly understood. We assessed the effects of three concentrations of PCB-11 on embryotoxicity and Aryl hydrocarbon receptor (Ahr) pathway interactions in zebrafish embryos (Danio rerio). Wildtype AB or transgenic Tg(gut:GFP) strain zebrafish embryos were exposed to static concentrations of PCB-11 (0, 0.2, 2, or 20 μM) from 24 to 96 h post fertilization (hpf), and gross morphology, Cytochrome P4501a (Cyp1a) activity, and liver development were assessed via microscopy. Ahr interactions were probed via co-exposures with PCB-126 or beta-naphthoflavone (BNF). Embryos exposed to 20 μM PCB-11 were also collected for PCB-11 body burden, qRT-PCR, RNAseq, and histology. Zebrafish exposed to 20 μM PCB-11 absorbed 0.18% PCB-11 per embryo at 28 hpf and 0.61% by 96 hpf, and their media retained 1.36% PCB-11 at 28 hpf and 0.84% at 96 hpf. This concentration did not affect gross morphology, but altered the transcription of xenobiotic metabolism and liver development genes, impeded liver development, and increased hepatocyte vacuole formation. In co-exposures, 20 μM PCB-11 prevented deformities caused by PCB-126 but exacerbated deformities in co-exposures with BNF. This study suggests that PCB-11 can affect liver development, act as a partial agonist/antagonist of the Ahr pathway, and act as an antagonist of Cyp1a activity to modify the toxicity of compounds that interact with the Ahr pathway.

A Metagenomic Approach to Evaluating Surface Water Quality in Haiti

The cholera epidemic that occurred in Haiti post-earthquake in 2010 has resulted in over 9000 deaths during the past eight years. Currently, morbidity and mortality rates for cholera have declined, but cholera cases still occur on a daily basis. One continuing issue is an inability to accurately predict and identify when cholera outbreaks might occur. To explore this surveillance gap, a metagenomic approach employing environmental samples was taken. In this study, surface water samples were collected at two time points from several sites near the original epicenter of the cholera outbreak in the Central Plateau of Haiti. These samples underwent whole genome sequencing and subsequent metagenomic analysis to characterize the microbial community of bacteria, fungi, protists, and viruses, and to identify antibiotic resistance and virulence associated genes. Replicates from sites were analyzed by principle components analysis, and distinct genomic profiles were obtained for each site. Cholera toxin converting phage was detected at one site, and Shiga toxin converting phages at several sites. Members of the Acinetobacter family were frequently detected in samples, including members implicated in waterborne diseases. These results indicate a metagenomic approach to evaluating water samples can be useful for source tracking and the surveillance of pathogens such as Vibrio cholerae over time, as well as for monitoring virulence factors such as cholera toxin.

Redox stress and signaling during vertebrate embryonic development: Regulation and responses

Vertebrate embryonic development requires specific signaling events that regulate cell proliferation and differentiation to occur at the correct place and the correct time in order to build a healthy embryo. Signaling pathways are sensitive to perturbations of the endogenous redox state, and are also susceptible to modulation by reactive species and antioxidant defenses, contributing to a spectrum of passive vs. active effects that can affect redox signaling and redox stress. Here we take a multi-level, integrative approach to discuss the importance of redox status for vertebrate developmental signaling pathways and cell fate decisions, with a focus on glutathione/glutathione disulfide, thioredoxin, and cysteine/cystine redox potentials and the implications for protein function in development. We present a tissue-specific example of the important role that reactive species play in pancreatic development and metabolic regulation. We discuss NFE2L2 (also known as NRF2) and related proteins, their roles in redox signaling, and their regulation of glutathione during development. Finally, we provide examples of xenobiotic compounds that disrupt redox signaling in the context of vertebrate embryonic development. Collectively, this review provides a systems-level perspective on the innate and inducible antioxidant defenses, as well as their roles in maintaining redox balance during chemical exposures that occur in critical windows of development.

Pancreatic beta cells are a sensitive target of embryonic exposure to butylparaben in zebrafish (Danio rerio)

BACKGROUND

Butylparaben (butyl p-hydroxybenzoic acid) is a common cosmetic and pharmaceutical preservative reported to induce oxidative stress and endocrine disruption. Embryonic development is sensitive to oxidative stress, with redox potentials playing critical roles in progenitor cell fate decisions. Because pancreatic beta cells have been reported to have low antioxidant gene expression, they may be sensitive targets of oxidative stress. We tested the hypotheses that butylparaben causes oxidative stress in the developing embryo, and that pancreatic beta cells are a sensitive target of butylparaben embryotoxicity.

METHODS

Transgenic insulin:GFP zebrafish embryos (Danio rerio) were treated daily with 0, 250, 500, 1,000, and 3,000 nM butylparaben. Pancreatic islet and whole embryo development were examined though 7 days postfertilization, and gene expression was measured by quantitative real-time PCR. Glutathione (GSH) and cysteine redox content were measured at 28 hr postfertilization using HPLC.

RESULTS

Butylparaben exposure caused intestinal effusion, pericardial edema, and accelerated yolk utilization. At 250 nM, beta cell area increased by as much as 55%, and increased incidence of two aberrant morphologies were observed-fragmentation of the islet cluster and ectopic beta cells. Butylparaben concentrations of 500 and 1,000 nM increased GSH by 10 and 40%, respectively. Butylparaben exposure downregulated transcription factor pdx1, as well as genes involved in GSH synthesis, while upregulating GSH-disulfide reductase (gsr).

CONCLUSIONS

The endocrine pancreas is a sensitive target of embryonic exposure to butylparaben, which also causes developmental deformities and perturbs redox conditions in the embryo.

Developmental Exposure to 2,2',4,4'-Tetrabromodiphenyl Ether Permanently Alters Blood-Liver Balance of Lipids in Male Mice

Polybrominated diphenyl ethers (PBDEs) were used as flame-retardant additives starting 1965 and were recently withdrawn from commerce in North America and Europe. Approximately 1/5 of the total U.S. population were born when environmental concentrations of PBDE plateaued at their maximum. Accumulating evidence suggests that developmental exposures to PBDE may result in long-lasting programming of liver metabolism. In this study, CD-1 mice were exposed prenatally or neonatally to 1 mg/kg body weight of 2,2',4,4'-tetrabromodiphenyl ether (BDE-47), and changes in liver histology, transcriptome, and liver-blood balance of triglycerides were analyzed in 10 months old male offspring. In both exposure groups, long-term reprogramming of lipid metabolism was observed, including increased liver triglycerides and decreased blood triglycerides, and altered expression of metabolic genes in the liver. Significant upregulation of lipid influx transporter Cd36 2.3- and 5.7-fold in pre- and neonatal exposure groups, respectively was identified as a potential mechanism of blood/liver imbalance of triglycerides. Analysis of our and previously published all-genome gene expression data identified changes in expression of ribosomal protein genes as a transcriptomic signature of PBDE exposure. Further comparison of our new data and published data demonstrate that low doses (0.2 mg/kg body weight) of PBDE induce long-lasting up-regulation of ribosomal genes, suppression of Cd36 in liver and increase circulating triglycerides in blood, while moderated doses (≥1 mg/kg body weight) produce opposite long-lasting effects. To conclude, this study shows that an environmentally relevant developmental exposures to BDE-47 permanently alter lipid uptake and accumulation in the liver, with low and moderate doses having opposite effect on liver transcriptomics and triglyceride balance. Similar effects of pre- and neonatal exposures point at hepatocyte maturation as a sensitive window of the liver metabolism programming. These results suggest that PBDE exposure may be an important factor increasing risks of cardio-vascular disease and non-alcoholic fatty liver disease via modulation of liver/blood balance of lipids. The translational relevance of these findings for human remain to be studied.

Actual vs. best practices for young children with cerebral palsy: a survey of paediatric occupational therapists and physical therapists in Quebec, Canada

RATIONALE

Cerebral palsy (CP) constitutes a substantial portion of paediatric rehabilitation, yet little is known regarding actual occupational therapy (OT) and physical therapy (PT) practices. This study describes OT and PT practices for young children with CP in Quebec, Canada.

METHODS

This was a cross-sectional survey. All eligible, consenting paediatric occupational therapists (OTs) and physical therapists (PTs) were interviewed using a structured telephone interview based on vignettes of two typical children with CP at two age points--18 months and 4 years. Reported practices were grouped according to the International Classification of Functioning, Disability and Health (ICF).

RESULTS

91.9% of PTs (n=62; 83.8% participation rate) and 67.1% of OTs (n=85; 91.4% participation rate) reported using at least one standardized paediatric assessment. OT and PT interventions focused primarily on impairments and primary function (such as gait function and activities of daily living). Both professions gave little attention to interventions related to play and recreation/leisure. Clinicians reported the need for more training and education specific to CP and to the use of research findings in clinical practice.

CONCLUSION

Wide variations and gaps were identified in clinicians' responses suggesting the need for a basic standard of OT and PT management as well as strategies to encourage knowledge dissemination regarding current best practice.

Knee height to predict stature in North American Caucasian frail free-living elderly receiving community services

CONTEXT

Height is an important component of anthropometric assessment. Valid measures of height are difficult to obtain in the frail elderly. Equations to predict height, using knee height, were proposed for healthy but not for frail elderly.

OBJECTIVE

The objectives of this study were to 1) develop and validate equations to predict height (measured and reported) in the frail elderly, 2) to verify the accuracy and reliability of equations, and 3) to compare predicted values with those predicted from existing equations for the healthy elderly.

DESIGN AND SETTING

This is a secondary analysis of data from three cross-sectional studies and three randomized community trials in the Sherbrooke area, Quebec, Canada.

PARTICIPANTS

Subjects (n=599) were Caucasian, aged 60 and over, and receiving community or Meals-on-Wheels services.

ANALYSES

Variables associated with measured and reported heights were entered in multiple linear regression models (n = 409) to identify independent prediction factors. Reliability assessment and agreement analysis were performed with a sub-group of subjects (n=190).

RESULTS

Knee height and age in men (R(2) = .718), and with the addition of weight and hip circumference in women (R(2) = .593), were identified as predictors of measured height. For reported height, knee height was a predictor in men (R(2) = .693), while weight was another predictor in women (R(2) = .540). These models predicted height just as well in the validation group (R(2) = .514 to .623). Errors of estimates ranged from +/- 3.31 cm to +/- 5.06 cm. Predicted values were closer to directly measured values in the frail elderly as compared to values obtained with equations in the healthy elderly which differed significantly.

CONCLUSIONS

Equations were developed to predict measured and reported height in the frail elderly. These equations can be used when height cannot be measured directly or when postural problems (for measured height) or cognitive disorders (for reported height) can cause unreliable measurements.

A search for specific and common susceptibility loci for schizophrenia and bipolar disorder: a linkage study in 13 target chromosomes

We report the first stage of a genome scan of schizophrenia (SZ) and bipolar disorder (BP) covering 18 candidate chromosomal areas. In addition to testing susceptibility loci that are specific to each disorder, we tested the hypothesis that some susceptibility loci might be common to both disorders. A total of 480 individuals from 21 multigenerational pedigrees of Eastern Québec were evaluated by means of a consensus best-estimate diagnosis made blind to diagnoses in relatives and were genotyped with 220 microsatellite markers. Two-point and multipoint model-based linkage analyses were performed and mod scores (Z, for max Z(max)) are reported. The strongest linkage signals were detected at D18S1145 (in 18q12; Z = 4.03) for BP, and at D6S334 (in 6p 22-24; Z(het) = 3.47; alpha = 0.66) for SZ. Three other chromosomal areas (3q, 10p, and 21q) yielded linkage signals. Chromosomes 3p, 4p, 5p, 5q, 6q, 8p, 9q, 11q, 11p, 12q, 13q, 18p and 22q showed no evidence of linkage. The 18q12 results met the Lander and Kruglyak (1995) criterion for a genome-wide significant linkage and suggested that this susceptibility region may be shared by SZ and BP. The 6p finding provided confirmatory evidence of linkage for SZ. Our results suggest that both specific and common susceptibility loci must be searched for SZ and BP.

Subtyping schizophrenia according to outcome or severity: a search for homogeneous subgroups

There is a growing consensus that current definitions of schizophrenia (SZ) include different disorders, or else different dimensions underlain by different pathophysiologies. This article reviews the evidence for the validity of three novel strategies to subtype SZ according to outcome or severity (deficit vs. nondeficit, Kraepelinian vs. non-Kraepelinian, congenital vs. adult-onset). Medline and bibliographies were used to locate articles. The methodology of the studies was reviewed, and their results were grouped according to seven validating criteria. Several differences were found between subtypes, particularly for the deficit/nondeficit subtypes. However, for most of these differences, replications have yet to be undertaken. Important indicators of etiology from the environmental risk factors and genetic domains have received very little attention. These three subtyping strategies represent promising attempts to address the etiologic heterogeneity of SZ. However, one cannot conclude whether these strategies identify etiologically distinct SZ subgroups. We propose ten methodological and conceptual recommendations for future studies aimed at the identification of valid SZ subtypes according to outcome or severity.

Male gender is associated with deficit schizophrenia: a meta-analysis

An association between deficit schizophrenia and male gender could be expected, since male schizophrenic subjects have been repeatedly found more severe than females on several dimensions of severity. Surprisingly, very few studies have confirmed such an association. We performed a more definitive test of this association using a meta-analysis. A pooled odds ratio was computed based on the 23 studies that reported the gender ratio in deficit vs. non-deficit schizophrenia. We tested for the heterogeneity of the association and examined the potential impact of the sampling method, the method used to assess the deficit syndrome, the breadth of diagnoses included and the mean duration of illness. A highly significant association between male gender and deficit schizophrenia was observed (pooled odds ratio=1.75). There was no definitive evidence that differences across studies in sampling methods, breadth of diagnoses included, mean duration of illness and methods to assess the deficit syndrome affected the strength of the association. However, the studies using the "Proxy Deficit Syndrome" method to assess the deficit syndrome yielded qualitatively weaker evidence. This significant association between male gender and deficit schizophrenia may reflect the influence of a gender related factor (e.g. sexual hormones) or gender differences in the liability to different etiologies of schizophrenia. The role of gender as a potential confounder must be closely examined in studies comparing deficit and non-deficit SZ.

Intensive surveillance and treatment of dyslipidemia in the postinfarct patient: evaluation of a nurse-oriented management approach

BACKGROUND

Lowering plasma low density lipoprotein (LDL) cholesterol concentrations in patients with established coronary artery disease is essential if recurrent cardiac events and mortality are to be prevented; however, a large proportion of patients with myocardial infarction (MI) are not screened and treated appropriately in the months immediately following hospital discharge.

OBJECTIVES AND METHODS

The CHOlesterol Post-INfarct (CHOPIN) project is a nurse-centred program initiated to close the large gap between nationally centred recognized guidelines for LDL lowering and current actual practice in the secondary prevention of coronary artery disease.

RESULTS

The authors report findings in 151 consecutive patients (70 years of age or less) followed for an average of 5.5+/-3.3 months. Three months after an index MI and at a time when patients started being followed in CHOPIN, 46% of patients had LDL in excess of 2.5 mmol/L and 36% had LDL greater than 3.20 mmol/L. LDL-lowering interventions undertaken comprised either consultation with a dietitian (35%) or initiation or modification of lipid-lowering medication (58%). Mean LDL on discharge from CHOPIN was 2.58+/-0.49 mmol/L, and 97% of the patients had LDL cholesterol less than 3.20 mmol/L at discharge.

CONCLUSIONS

This experience shows that a nurse-based case management strategy can achieve good control of dyslipidemia in a large proportion of post-MI patients. Because intervention to lower LDL has been prospectively shown to reduce the need for coronary artery bypass and angioplasty, these results suggest that projects configured in the manner of CHOPIN should reduce hospital costs associated with cardiovascular disease.

[Introduction to genetic psychiatry: progress in uncovering genetic susceptibility to psychiatric disorders]

The recent progress in human genetics suggests major benefits in clinical practice, including psychiatry. This article introduces the research methodology used in psychiatric genetics and explains how it is applied, for a better understanding of the challenges facing psychiatric genetics and the strategies being used to overcome them. We will review the evidence of genetic factors in psychiatric disorder etiology as well as the specificity or non-specificity of their expression. We will discuss problems associated with the approximate nature of diagnostic methods, the incomplete penetrance and the genetic heterogeneity of psychiatric disorders, the presence of phenocopies and our uncertainty concerning the mode of inheritance of psychiatric disorders. Finally, we will provide an overview of the most promising results and set out priorities for future studies.

Prolongation of brainstem auditory-evoked responses in autistic probands and their unaffected relatives

BACKGROUND

Brain function, as indexed by brain electrical activity, is heritable in humans, and it may be impaired in autism. Autism also has strong genetic determinants, and like all major psychiatric disorders, its complex clinical phenotype renders genetic studies difficult. Innovative strategies focused on alternative biological phenotypes are needed.

METHODS

The early brain auditory-evoked response was assessed in 73 autistic probands and 251 relatives who were compared with 521 normal controls.

RESULTS

We first confirmed in the autistic probands the presence of a slowing in nerve conduction in the auditory system as expressed by the prolongation of early brain auditory-evoked response under the form of I-III interpeak latencies (IPLs). Furthermore, we observed the same I-III IPL prolongation in the unaffected first degree relatives of the autistic probands compared with controls. Despite clear evidence of a coaggregation of autism and I-III IPL prolongation in families, the IPLs did not seem to be the sole liability factor for autism as suggested by the observation of 52% of families in which the autistic proband and relatives showed normal IPLs.

CONCLUSION

A prolongation of the early brain auditory-evoked response IPLs may be a marker for one of several deficits underlying autism and deserves further analysis as a potential alternative phenotype for the disorder.

Significant linkage for Tourette syndrome in a large French Canadian family

Family and twin studies provide strong evidence that genetic factors are involved in the transmission of Gilles de la Tourette syndrome (TS) and related psychiatric disorders. To detect the underlying susceptibility gene(s) for TS, we performed linkage analysis in one large French Canadian family (127 members) from the Charlevoix region, in which 20 family members were definitely affected by TS and 20 others showed related tic disorders. Using model-based linkage analysis, we observed a LOD score of 3.24 on chromosome 11 (11q23). This result was obtained in a multipoint approach involving marker D11S1377, the marker for which significant linkage disequilibrium with TS recently has been detected in an Afrikaner population. Altogether, 25 markers were studied, and, for level of significance, we derived a criterion that took into account the multiple testing arising from the use of three phenotype definitions and three modes of inheritance, a procedure that yielded a LOD score of 3.18. Hence, even after adjustment for multiple testing, the present study shows statistically significant evidence for genetic linkage with TS.

Longitudinal comparative study of risperidone and conventional neuroleptics for treating patients with schizophrenia. The Quebec Schizophrenia Study Group

This study compared the long-term (12 months) effectiveness of risperidone (RP) with that of conventional neuroleptics (CNs) in a population with chronic schizophrenia who had shown suboptimal response to CNs. A randomized, open, parallel, multicenter design was used. One hundred eighty-four subjects meeting DSM-IV criteria for schizophrenia were randomly assigned to receive either RP or a CN, and 165 of them completed the follow-up. Outcome measures were taken at 3, 6, and 12 months and included the Positive and Negative Syndrome Scale (PANSS) and the Extrapyramidal Symptom Rating Scale. Within this 12-month follow-up, RP was found to be superior to CNs in terms of both the average change in score from baseline on the PANSS (p = 0.006) and the proportion of good responders (as defined by a 20% decrease in total PANSS scores;p = 0.03). For positive symptoms, the effectiveness of the RP treatment tended to increase over time. At 12 months, the percentage of good responders in the RP group was twice as large as that in the CN group (30% vs. 15%;p = 0.03). The superiority of RP over CNs was constant over the three dose categories. In both the RP and the CN groups, the maximum decrease in psychopathology was achieved with the lowest dose range. A worsening of akathisia was less frequent in subjects receiving RP than in those receiving CNs (p = 0.02). In conclusion, this study showed that, compared with CNs, RP is beneficial in the treatment of patients with chronic schizophrenia and that some of these benefits may appear only after longer-term treatment.

Anticipation in schizophrenia and bipolar disorder controlling for an information bias

Anticipation was investigated in schizophrenia (SZ) and bipolar disorder (BP) while addressing several biases in 18 large families (154 subjects) from Eastern Québec densely affected by SZ, BP, or both over three generations. In particular, we controlled for an information bias using a measure of quality and quantity of clinical information (QOI) concerning the subjects' illness. Otherwise, spurious anticipation could have arisen because we found that QOI varied with the generations as well as with the severity of illness. Although anticipation was investigated separately for SZ and BP, both disorders were also included in one analysis that tested anticipation under the unitary hypothesis that the SZ and the BP spectrums represent a continuum of severity of the same disease. Age of onset (AOO) and five indices of severity were tested for anticipation. Two statistics were used: the difference in the mean AOO or severity between two successive generations, and the mean difference in parent-offspring pairs (POP). The study led to four main findings: 1) the choice of the statistics greatly influenced the results, POP yielding systematically greater biased estimates; 2) for SZ and BP, the evidence for anticipation with the five severity indices vanished after controlling for QOI; 3) as regards AOO a decrease of 8.6 years, p = 0.0001, and 5.3 years, p = 0.009 in AOO was found for SZ between Generations 1-2, and 2-3, respectively, despite controlling for QOI and addressing all biases; and 4) conversely for BP, anticipation with AOO may be due to censoring. Findings suggest that future anticipation studies should also control for QOI. Am. J. Med. Genet. (Neuropsychiatr. Genet.) 96:61-68, 2000.

Evidence of linkage in subtypes of alcoholism

We believed that subtyping alcoholism might be an efficient strategy for mapping susceptibility genes. Cluster analysis is one of the possible statistical techniques for such a purpose. We required that, ideally, the variables to be used in cluster analysis should be: 1) related to alcoholism, 2) related to the severity of alcoholism, and 3) familial, i.e., correlated within families. Only three variables met all three conditions. Those included age of onset of ALDX1, smoking, and TPQ-HA. A global score of symptoms of alcoholism was systematically introduced as one of the variables composing a subset for cluster analysis, although this score did not show any familial aggregation. Our strategy led to a strong evidence of linkage at D15S230 in only 20 families whose members are mainly characterized by heavy smoking.

WISP genes are members of the connective tissue growth factor family that are up-regulated in wnt-1-transformed cells and aberrantly expressed in human colon tumors

Wnt family members are critical to many developmental processes, and components of the Wnt signaling pathway have been linked to tumorigenesis in familial and sporadic colon carcinomas. Here we report the identification of two genes, WISP-1 and WISP-2, that are up-regulated in the mouse mammary epithelial cell line C57MG transformed by Wnt-1, but not by Wnt-4. Together with a third related gene, WISP-3, these proteins define a subfamily of the connective tissue growth factor family. Two distinct systems demonstrated WISP induction to be associated with the expression of Wnt-1. These included (i) C57MG cells infected with a Wnt-1 retroviral vector or expressing Wnt-1 under the control of a tetracyline repressible promoter, and (ii) Wnt-1 transgenic mice. The WISP-1 gene was localized to human chromosome 8q24.1-8q24.3. WISP-1 genomic DNA was amplified in colon cancer cell lines and in human colon tumors and its RNA overexpressed (2- to >30-fold) in 84% of the tumors examined compared with patient-matched normal mucosa. WISP-3 mapped to chromosome 6q22-6q23 and also was overexpressed (4- to >40-fold) in 63% of the colon tumors analyzed. In contrast, WISP-2 mapped to human chromosome 20q12-20q13 and its DNA was amplified, but RNA expression was reduced (2- to >30-fold) in 79% of the tumors. These results suggest that the WISP genes may be downstream of Wnt-1 signaling and that aberrant levels of WISP expression in colon cancer may play a role in colon tumorigenesis.

Clinical and methodological factors related to reliability of the best-estimate diagnostic procedure

OBJECTIVE

The reliability and accuracy of the best-estimate diagnostic procedure were examined, and factors associated with reliability were determined.

METHOD

The subjects were 134 members of large multigenerational pedigrees densely affected by bipolar disorders or schizophrenia. Three best-estimate diagnoses were derived: first, by a research psychiatrist and research assistant unblind to the relatives' diagnoses; second, by two blind independent psychiatrists; third, by a panel of four blind psychiatrists. The subjects were characterized on several clinical and methodological variables, which were used to compare the agreements of two types of best-estimate diagnoses with the disagreements.

RESULTS

There was satisfactory agreement between the unblind and blind consensus best-estimate diagnoses and between the two blind independent psychiatrists. Latent class analyses revealed that limited sensitivity was the main source of imperfect reliability. Confusability analyses revealed that the most problematic diagnostic distinctions involved schizoaffective disorder, which was confused with schizophrenia, bipolar I disorder, and schizophreniform disorder. Blindness significantly affected diagnostic outcome in latent class analyses. Moreover, for diagnostic disagreements, unblind diagnoses had greater continuity with the most predominant diagnosis in the pedigree than did blind diagnoses. Diagnostic disagreements were associated with the presence of mixed affective and psychotic symptoms, less diagnostic certainty, and shorter duration of illness.

CONCLUSIONS

These results suggest that it is possible to identify cases that are more likely to lead to diagnostic disagreements in family and epidemiological studies and that blind diagnoses may help to prevent false positive diagnoses, which may be particularly detrimental to genetic linkage analyses.

Inflammatory bowel disease

The vast majority of patients with inflammatory bowel disease experience chronic symptoms punctuated by periodic exacerbations requiring adjustments in medical therapy or surgery. True emergencies are fortunately uncommon but have been associated with high rates of morbidity and mortality. Patients presenting with fulminant colitis, toxic megacolon, or perforation require prompt identification as well as intensive medical therapy and monitoring by physicians and surgeons experienced in the care of such patients. Recent advances in the evaluation and treatment of these complicated patients are reviewed.

6p24-22 region and major psychoses in the Eastern Quebec population. Le Groupe IREP

Recent reports of a linkage trend in 6p24-22 for schizophrenia (SZ), in different samples, were tempered by the concurrent evidence of negative reports in other samples. In the studies showing positive results, different definitions of affection and a wide spectrum of diagnoses were used. Our objectives were not only to test for linkage at 6p24-22 in the Eastern Quebec population, but also to test whether this putative vulnerability locus was either selectively linked to schizophrenia (SZ), or to bipolar disorder (BP), or to both major psychoses. Parametric and nonparametric linkage analyses with 12 microsatellite markers in 6p24-p22 were performed on a sample of 18 large multigenerational pedigrees (N = 354) either affected by SZ, or by BP, or equally affected by both major psychoses (i.e., mixed pedigrees). Three affection definitions were usually tested in our program: one on schizophrenia (SZ), one on bipolar disorder (BP), and one that comprised SZ and BP under the hypothesis of a susceptibility locus common to both in major psychoses (common locus, CL). The results of parametric analyses did not support a major gene hypothesis. However, in one large mixed pedigree (#151), we observed with the common locus phenotype (CL) lod scores of 2.49 and 2.15, respectively, at the D6S296 and D6S277 loci under a dominant model. Our data suggest the presence of a potential vulnerability locus at 6p24-22 that could be related to both schizophrenia and bipolar affective disorder. These results may be seen as congruent with former studies that used schizoaffective as well as schizophrenia diagnoses as entry criteria for the affected families, and used an affection definition that comprised affective psychoses as well as schizophrenia.

Selecting a control group in studies of the familial coaggregation of two disorders: a quantitative genetics perspective

We sought to compare four different definitions of control groups in studies of the coaggregation between two disorders (A and B) on: 1) their ability to detect valid familial coaggregation; 2) their liability to artifactual evidence for familial coaggregation; and 3) their robustness to the overselection of comorbid cases. Using a quantitative genetic model of transmission, we simulated sibling pairs with familial and nonfamilial sources of comorbidity. Four different definitions of controls were tested to predict disorder B in siblings of cases vs. controls: 1) unscreened controls included subjects with A or B as well as subjects with either A or B; 2) in the symmetrical selection method, controls included only subjects without A; 3) supernormal controls included only subjects without A or B; and 4) in the pure proband method, cases included subjects with A only, and controls included only subjects without A or B. In the absence of selection bias, 1) the unscreened control and the symmetrical selection methods did not yield spurious evidence for familial coaggregation and could detect familial coaggregation; 2) the supernormal controls yielded spurious evidence of familial coaggregation; and 3) the pure proband method sometimes yielded spurious evidence for negative familial coaggregation, and had limited power to detect familial coaggregation. However, the pure proband method was the only one unaffected by overselection of comorbid cases. In the absence of selection bias, both the unscreened control and the symmetrical selection methods are appropriate, and the robustness of the pure proband method to overselection of comorbid cases may be an interesting feature in studies using clinical samples. Moreover, quantitative genetics methods may offer important advantages in the study of familial coaggregation.

Childhood/early adolescence-onset and adult-onset schizophrenia. Heterogeneity at the dopamine D3 receptor gene

BACKGROUND

The dopamine D3 receptor gene (DRD3) is a meaningful candidate gene because it unifies the dopamine and the limbic hypotheses for schizophrenia. We tested for an allelic association between schizophrenia and the DRD3 Mscl alleles, hypothesising heterogeneity between childhood/early adolescence-onset schizophrenia (CO-SZ) and adult-onset schizophrenia (A-SZ).

METHOD

The frequencies of the DRD3 alleles were compared between 70 DSM-III-R schizophrenics (35 CO-SZ and 35 A-SZ) and 79 controls.

RESULTS

Compared with the controls, the subsample of A-SZ, but not CO-SZ, showed an over-proportion (P = 0.025) of allele 1. The association was not found in the total sample, combining the two subsamples.

CONCLUSIONS

Consistently with former studies, our data suggest an aetiological heterogeneity between CO-SZ and A-SZ and a possible specificity of the excess of allele 1 to the familial form of schizophrenia and to schizophrenia with a better outcome.

Long-term stability of diagnosis and symptom dimensions in a systematic sample of patients with onset of schizophrenia in childhood and early adolescence. II: Postnegative distinction and childhood predictors of adult outcome

BACKGROUND

The aim of this study was to verify the presence and stability across life of the positive/negative distinction in early-onset schizophrenia (EO-SZ) through a longitudinal factor analysis of the schizophrenic dimensions, and to identify the factors predicting several indices of long-term outcome for EO-SZ.

METHOD

Forty children consecutively referred for DSM-III-R schizophrenia (SZ) in a specific catchment area comprised the sample.

RESULTS

Across a 14.8-year follow-up, longitudinal factor analysis identified two separate factors corresponding to the positive and negative symptom dimensions. We also observed that: the GAS rated over the last three years of adult illness and the severity of negative symptoms during the stabilised interepisode intervals in adulthood were the indices of adult outcome that were most easily predicted; and the best childhood predictors of adult outcome were premorbid functioning and severity of positive and negative symptoms during acute episodes.

CONCLUSIONS

The presence of premorbid non-psychotic behaviour disturbances (NPBD) and premorbid developmental problems was not related to severity of outcome, in contrast to the former variables.

Long-term stability of diagnosis and symptom dimensions in a systematic sample of patients with onset of schizophrenia in childhood and early adolescence. I: nosology, sex and age of onset

BACKGROUND

Little is known about the long-term outcome of schizophrenia that has its onset during childhood and early adolescence (early-onset schizophrenia, or EO-SZ). Whether or not EO-SZ is an aetiologically separate form of schizophrenia (SZ) is unresolved.

METHOD

The study was a 14.8-year follow-up, using methods such as systematic sampling, evaluation of possible non-respondent bias, consensus best-estimate diagnoses (DSM-III-R) made independently in childhood and adulthood, measures of positive and negative dimensions, of non-psychotic behaviour disturbances (NPBD) and of developmental problems before the appearance of SZ.

RESULTS

There was high stability of EO-SZ (n = 40) diagnoses (mean onset at 14.0 years) until adulthood (mean age at follow-up 28.8 years) but a lower stability of positive and negative schizophrenic dimensions. There was a poor outcome of EO-SZ, a strong over-representation of males but few gender differences, and no effect of age of onset on clinical features and outcome.

CONCLUSIONS

EO-SZ taken as a whole shows no qualitative differences to adult-onset SZ. However, a distinction through the onset of preschizophrenic developmental problems or NPBD might be a way to investigate heterogeneity within EO-SZ.

Accuracies and inaccuracies of the family history method: a multivariate approach

This paper reports on 1459 first-degree relatives of probands with schizophrenia or affective illness and matched community controls. We sought (i) to validate psychiatric diagnoses obtained by family history (FH) against those obtained by a best estimate (BE) procedure based on personal interview and (ii) to explore the factors influencing the accuracy of the FH report. We found relatively poor agreement between the FH and BE diagnoses, and the disagreements were influenced by numerous factors, including gender, psychiatric status of the informant or proband's diagnosis. When validated against a BE diagnosis, the overall accuracy of the FH method is relatively poor, and is furthermore subject to several biases. Therefore, substituting the FH method for BE diagnosis may be an important source of error in the investigation of familial/genetic factors in psychiatric disorders.

No difference found between winter- and non-winter-born schizophrenic cases

The distinction between winter-born (WBS) and non-winter born (NWBS) schizophrenic cases has been proposed as a strategy to identify distinct etiologic subtypes within schizophrenia, the WBS subgroup being a predominantly environmental subtype. The goal of this paper is to empirically test the validity of this strategy by comparing WBS and NWBS groups on a broad array of clinical and biological variables. DSM-III-R schizophrenic, schizoaffective and schizophreniform subjects were comprehensively assessed using (i) the Comprehensive Assessment of Symptoms and History; (ii) a comprehensive neurological exam; (iii) a neuropsychological battery, including IQ and the Continuous Performance Test and (iv) an MRI scanning. The patients were divided into WBS and NWBS, using five alternative sets of definitions of winter birth. These comparisons yielded no differences between the groups on any of the 23 variables. The results suggest that the distinction between winter-born and non-winter-born cases has very limited power to identify distinct schizophrenic subtypes, and that better delineation of the correlates of environmental risk factors in schizophrenia will require a better identification of these factors.

Validity of a diagnosis of lifetime major depression obtained by personal interview versus family history

OBJECTIVE

Diagnoses obtained by family history agree only modestly with those obtained through personal interview. If personal interview diagnoses are the "gold standard," these findings suggest that family history diagnoses have low validity. Here the authors take another perspective--to evaluate family history versus personal interview diagnoses of lifetime major depression by three independent validators.

METHOD

In a large sample of female-female twin pairs and their parents (903 families) ascertained from a population-based twin register, all subjects were personally interviewed by using a modified Structured Clinical Interview for DMS-III-R. Family history diagnoses based on the Family History Research Diagnostic Criteria were obtained by questioning each participant about his or her relatives. By means of multiple regression, the powers of the personal interview and family history methods were compared to predict 1) future episodes of major depression in the twins, 2) neuroticism, and 3) familial aggregation of major depression.

RESULTS

Agreement between diagnoses obtained by personal interview and family history was modest. After the presence or absence of a personal interview diagnosis of major depression was controlled for, a family history diagnosis of major depression significantly predicted future episodes of major depression, neuroticism (in five of six analyses), and familial aggregation of major depression (in four of six analyses).

CONCLUSIONS

Although agreeing relatively poorly, diagnoses of lifetime major depression obtained by personal interview and family history both contained useful information about future episodes, personality, and familial liability to illness. A multimethod approach to assessment of psychiatric illness may maximize the validity of psychiatric diagnoses.

Negative, psychoticism, and disorganized dimensions in patients with familial schizophrenia or bipolar disorder: continuity and discontinuity between the major psychoses

OBJECTIVE

This study aimed to answer the following questions: 1) Can we reliably measure the psychopathologic dimensions of schizophrenia by using a lifetime frame and by rating acute and interepisode periods separately? 2) Can we reproduce in subjects with familial schizophrenia the characteristic three-factor structure of schizophrenic symptoms that has been found previously in general groups of schizophrenic patients? 3) Is the factor structure also present in familial bipolar disorder?

METHOD

Lifetime measures of psychotic symptoms were taken through a slightly modified version of the Comprehensive Assessment of Symptoms and History for 138 patients with highly familial DSM-III-R schizophrenia (N = 51), bipolar disorder (N = 44), or spectrum disorders (N = 43). Symptoms were rated separately in the acute episodes and in the stabilized interepisode intervals across the patients' lives.

RESULTS

A satisfactory level of reliability was obtained. In this highly familial study group, the positive/negative factorial distinction was replicated, as was a three-factor model similar to that observed in prior general groups of schizophrenic patients. These factors were also present in bipolar affective disorder. The negative, psychoticism, and disorganized factor model applied more to the acute phase of illness than to the stabilized state.

CONCLUSIONS

These findings offer an empirical basis for testing biological or genetic variables in relation to negative/positive symptom dimensions, rather than diagnoses. Observations of a shared structure for schizophrenia and bipolar disorder suggest some continuity in the causes of these disorders.

A twin study of generalized anxiety disorder and major depression

Previous analyses with a sample of female twins sampled from the general population in Virginia have suggested that generalized anxiety disorder (GAD) and major depression (MD) share their genetic determinants but have partly different environmental determinants. The goal of this report is to examine whether these findings apply to samples that include male as well as female twins and contain high proportions of subjects who had been hospitalized for MD. The subjects were ascertained through two different sources: (i) index probands were ascertained through the Swedish Psychiatric Twin Registry for a diagnosis of unipolar or bipolar affective illness; (ii) control twin probands were ascertained through the Swedish Twin Registry. Subjects were sent questionnaires for the assessment of lifetime history of GAD and MD. Positing multinormal distribution of the liability for GAD and MD, we fitted bivariate models to examine the sources of comorbidity. The full model included additive genetic effects, shared environment and individual-specific environment, as well as scalar and non-scalar sex limitations and different thresholds across genders. The best-fitting model included: (i) a genetic correlation of unity; (ii) no common environment; (iii) an individual-specific environmental correlation of 0.28; (iv) different thresholds across genders, but neither scalar nor non-scalar sex-limitations. A model that included additive and dominant genetic effects and individual-specific environment, with correlation of unity for both additive and dominant genetic effects, provided an equivalent fit. These analyses confirm that GAD and MD share the same genetic factors but that their environmental determinants are mostly distinct. Moreover, the present report supports the feasibility of combining clinical ascertained and general-population samples into a single bivariate analysis.

The genetic epidemiology of self-esteem

BACKGROUND

Previous studies on self-esteem have focused exclusively on its psychosocial determinants. The goal of the present study is to clarify genetic v. environmental determinants of self-esteem.

METHOD

Participants were Caucasian women sampled from the Virginia Twin Register: 363 pairs of MZ and 238 pairs of DZ twins were available from the first wave of the study, and 430 pairs of MZ and 308 pairs of DZ twins from the second. Self-esteem was assessed with the Rosenberg's Self-Esteem Scale.

RESULTS

Using univariate twin analyses of self-esteem and a repeated measurement twin model, we found that self-esteem is a moderately heritable trait (heritability = 52% in the repeated measurement model); environmental influences are also very important, and are probably mostly not shared by members of a twin pair.

CONCLUSIONS

Aetiological models of self-esteem which examine only psychosocial factors are incomplete; genetic factors need to be integrated.

Magnetic resonance imaging in familial versus sporadic cases of schizophrenia

Magnetic resonance imaging findings were compared in 22 familial and 29 sporadic cases with DSM-III-R diagnoses of schizophrenia, schizoaffective, or schizophreniform disorders. Volumetric measurements were used to assess the size of brain structures, including the cranium, cerebrum, lateral ventricles, temporal horns, third ventricle, lenticular nuclei, amygdaloid-hippocampal complex, and cerebellum, as well as the asymmetry of the lateral ventricles. Increased volume of the lenticular nuclei and greater ventricular asymmetry (the left ventricle being larger) were found in familial cases compared with sporadic cases and normal control subjects. It is possible that increased lenticular nuclei volume and greater lateral ventricular asymmetry reflect the role of genetic factors in schizophrenia.

[Positive and negative symptoms in schizophrenia: a current overview]

The purpose of this article is to summarize the results of studies examining the validity of the positive and negative sub-types of schizophrenia as proposed by Crow. The authors summarized Crow's model's predictions in the form of 12 research questions and examined whether its predictions were confirmed. The following predictions are generally confirmed by the data collected: (i) it is possible to measure negative symptoms with accuracy; (ii) the negative symptoms predict a deterioration; (iii) the negative symptoms are generally correlated with overall cognitive deficits; (iv) each dimension appears to have distinct neurobiological substrata. However, several elements of the Crow model are not supported by the data collected. Among the necessary modifications, the most important are as follows: (i) it appears more productive to conceive of the negative symptoms as distinct dimensions, rather than distinct diseases; (ii) at least three dimensions exist for describing the symptoms of schizophrenia; (iii) the negative symptoms are not necessarily intrinsic to the schizophrenic process, and they may be due to other causes; (iv) the negative symptoms are not necessarily irreversible, and can be improved under ataractics; (v) the positive symptoms, in particular those relating to disorganization, can also be correlated with cognitive deficits.

Biases in the diagnosis of alcoholism by the family history method

The authors explored the factors influencing the agreement of diagnoses of alcoholism obtained by a best-estimate (BE) procedure versus those obtained by family history (FH) only, based on data from the Roscommon Family Study. The participants were first-degree relatives of either schizophrenic subjects, subjects with affective disorders, or matched community controls. The FH information was obtained from first-degree relatives of the participants, whereas the BE diagnoses included personal interview and medical records as well as FH information. Two types of error were distinguished: false-negative FHs, who were diagnosed with alcoholism by BE but not by FH; and false-positive FHs, who were diagnosed with alcoholism by FH but not by BE. The risk of false-negative FHs was increased by young age of the subject and male gender of the informant, and decreased by a history of previous hospitalization of the subject. Conversely, the risk for false-positive FHs was increased by older age of the subject, male gender of the subject, female gender of the informant, and informant's diagnosis of alcoholism. Comorbid diagnosis of nonaffective psychosis increased the risk of both types of error. It is concluded that when validated against a BE diagnosis, the FH diagnosis of alcoholism is subject to several biases and that the FH method is not a satisfactory substitute for BE diagnoses.

Validity of the familial and sporadic subtypes of schizophrenia

OBJECTIVE

A common means of subtyping schizophrenia is to use family history. Familial schizophrenia is defined by a family history of psychotic disorders, and sporadic schizophrenia is defined by the absence of such a history. Some writers have proposed that familial cases are mostly genetic, while the causes of sporadic schizophrenia are primarily environmental. The object of this report is to consider the theoretical and empirical support for the validity of this classification.

METHOD

A review of studies examining the familial-sporadic distinction in schizophrenia was based on papers located through a MEDLINE search and published bibliographies. Because of the great variation in the methodological rigor of the studies, the authors rated them on a scale assessing 10 methodological features. Studies achieving at least 50% of the maximum possible score were selected for review.

RESULTS

Only 29 of 69 studies located met the selection criteria, and even among the studies selected, important methodological shortcomings were noted. Despite an impressive number of comparisons between groups of subjects with familial and sporadic schizophrenia, few differences were found. In addition, few differences were replicated and supported by studies using designs other than the familial-sporadic distinction.

CONCLUSIONS

The scarcity of studies with adequate methodology precludes any definitive judgment about the validity of the familial-sporadic distinction in schizophrenia. The delineation of predominantly genetic and predominantly environmental subtypes of schizophrenia will likely require large sample sizes, valid methods for the diagnosis of relatives, and stringent definitions of familiarity and sporadicity. Moreover, research strategies other than the familial-sporadic distinction may be better suited to identify such subtypes.

Epidemiological and clinical correlates of familial and sporadic schizophrenia

We studied 68 schizophrenic cases with a schizophrenic first-degree relative (familial group) and 62 cases without such a family history (sporadic group). We compared them on: (i) clinical variables, including premorbid adjustment, age of onset and severity of symptoms; (ii) neural abnormalities, including abnormal involuntary movements, neural "soft" and "hard signs"; (iii) neuropsychological tests, including the Wechsler Adult Intelligence Scale and the Continuous Performance Test and (iv) environmental risk factors, including winter birth and obstetrical complications. Sporadic cases were more likely to be born in winter and had more severe psychotic symptoms, but most analyses yielded no difference between the groups. Our results offer some support that sporadic schizophrenia is a more environmental subtype, but they also suggest that the familial vs sporadic distinction of schizophrenia has limited power to identify distinct subgroups.