Electroconvulsive therapy in a tertiary Australian mental health facility between 2009 and 2020.

BACKGROUND: Despite electroconvulsive therapy being one of the most effective treatments in psychiatry, few studies report trends in the provision of electroconvulsive therapy over time. This study aims to investigate the use of electroconvulsive therapy between 2009 and 2020 in an Australian public tertiary mental health facility, and to describe the electroconvulsive therapy patient population and change in courses of treatment. METHODS: Routinely collected data for 677 patients who received 1669 electroconvulsive therapy courses of treatment at an Australian public tertiary mental health facility between 2009 and 2020 were examined. RESULTS: The provision of acute electroconvulsive therapy was stable across the study period; however, the number of maintenance electroconvulsive therapy courses commenced declined over the study. Schizophrenia was the most common indication for index treatment (37.4%). The majority of patients (85.7%) received acute electroconvulsive therapy only. Voluntary provision of electroconvulsive therapy declined over the study period, reducing from 44.9% in 2009 to 16.3% in 2020. CONCLUSION: Over the study period, there was a significant reduction in the number of maintenance electroconvulsive therapy courses commenced, and a large increase in involuntary treatment. The provision of electroconvulsive therapy was more likely to occur in males with a diagnosis of schizophrenia. Further studies are needed to generate a greater understanding of the factors influencing the provision of electroconvulsive therapy within differing geographical, social and healthcare landscapes.

A two-generation study of attachment in mothers and their young adult offspring: Latent classes of attachment and associations with anxiety and depression.

BACKGROUND: Evidence supports the conceptualization of adult attachment as existing along a continuum of attachment security and insecurity; however, ongoing debates persist regarding the use of categorical versus continuous approaches to studying attachment. Attachment data collected from a large community sample of mothers and their offspring in young adulthood were used to examine i) latent classes of adult attachment, ii) associations between mother and offspring attachment, iii) the relationship between adult attachment and mental health symptoms. METHODS: Mothers and offspring were each administered the Attachment Style Questionnaire when offspring were aged 21-years. Latent class analyses (LCA) were performed to examine response patterns across ASQ items. Associations between mothers' and offspring attachment, and correlations between attachment domains and depression/anxiety subscales were examined. RESULTS: LCA identified four latent classes across a continuum of secure and insecure attachment rather than four distinct adult attachment styles. Anxious attachment subscales correlated strongly with depression/anxiety symptoms in both cohorts. Mothers' attachment was significantly but weakly correlated with their young adult offspring attachment. LIMITATIONS: Attachment was measured at one time point and as such, a causal maternal-offspring attachment relationship could not be established. CONCLUSIONS: Findings support a dimensional view of attachment security and insecurity over a four-category model of adult attachment. Attachment correlated with anxiety and depressive symptoms and highlights the importance of considering adult attachment when addressing mental health. There was limited evidence of a relationship between middle aged mothers and their offspring in young adulthood, suggesting other factors influence attachment in adulthood.

The unique role of adolescent internalizing and externalizing problems, and maternal-adolescent communication in their association with attachment in early adulthood.

Attachment styles influence mental health and relationships through life. Few studies examine the adolescent factors associated with adult attachment styles. This paper examines the association between adolescent emotional and behavioral problems and maternal-adolescent communication with attachment style in early adulthood. Data from 3423 participants in a birth cohort study were examined. At 14-years, participants' mothers completed the Parent-Adolescent Communication Scale. Participants completed the Youth Self-Report at 14-years which measures internalizing and externalizing symptoms, and the Attachment Style Questionnaire (ASQ) at 21-years. The ASQ comprises five domains of internal working models of interpersonal relationships and attachment style: confidence (security), discomfort with closeness and relationships as secondary (avoidance), need for approval and preoccupation with relationships (anxiety). Associations were examined using general linear models. After adjustments, internalizing symptoms score was associated with all domains of attachment and externalizing symptoms score was associated with four domains of attachment insecurity, but not attachment security. Low openness in maternal-adolescent communication was most strongly associated with decreased confidence and high problem maternal-adolescent communication was associated with viewing relationships as secondary. Adolescents with emotional and behavioral problems and maternal-adolescent communication may benefit from attachment-based interventions to support the development of healthy relationships and attachments in young adulthood.

The Kessler Psychological Distress Scale in Australian adolescents: Analysis of the second Australian Child and Adolescent Survey of Mental Health and Wellbeing.

INTRODUCTION: The 10-item Kessler Psychological Distress Scale (K10) is used to screen adolescents for mental disorders in Australian clinical practice; however, there are no Australian adolescent normative data. METHODS: Data were drawn from a nationally representative sample (N = 2964) of Australian adolescents (11-17 years). This study had three aims: (1) to examine concurrent validity between the K10 and Strengths and Difficulties Questionnaire (SDQ) emotional symptoms subscale, (2) to establish normative Australian adolescent K10 data and (3) to determine optimal K10 cut-off scores for screening for major depressive disorder (MDD) via receiver operator characteristic curve analysis and stratum-specific likelihood ratios. RESULTS: The K10 and SDQ emotional symptoms scales were moderately correlated (rs = 0.63, p < 0.001). Older female adolescents reported higher total K10 scores compared with younger female adolescents (15-17 years: M = 20.2, standard error [SE] = 0.3; 11-14 years: M = 16.8, SE = 0.3) and male adolescents (11-14 years: M = 16.6, SE = 0.2; 15-17 years: M = 16.0, SE=0.2). K10 scores to optimally discriminate those with and without MDD varied by age and sex and had low specificities. Stratum-specific likelihood ratios indicated adolescents with a K10 score of ≥30 will have a 12.9 (95% confidence interval = [10.2, 16.2]) increased likelihood of MDD. CONCLUSION: The K10 has utility for assessing psychological distress in health care and epidemiological research in Australian adolescents. Adolescents with K10 scores in the 'very high' range are at increased risk of MDD. Further assessment of these young people is indicated to identify those with or at risk of developing MDD.

'Who you gonna call?' A qualitative study of psychiatrists accessing mental health services.

OBJECTIVE: To identify motivation, capabilities and opportunities that enable psychiatrists and registrars to seek help for mental health problems and to inform design of interventions. METHOD: Data collected in qualitative semi-structured interviews were analysed using a framework approach with the COM-B model of behaviour as a theoretical frame. RESULTS: Accounts of the eight participants show help-seeking to be a complex process requiring cognitive and emotional capability to recognise a problem or goal, acceptance of vulnerability, and facilitated by access to professional networks. Help-seeking was enabled by openness about mental health problems in workplace culture. CONCLUSIONS: Interventions to enable help-seeking should focus on normalising the experience of mental health problems among doctors and challenge the notion that difficulties represent characterological flaws. Greater understanding of the mandatory reporting requirements is also required.

Sense of purpose interventions for depression and anxiety in youth: A scoping review and cross-cultural youth consultation.

BACKGROUND/OBJECTIVES: To investigate the effectiveness, feasibility, and acceptability of sense of purpose (SOP) interventions in preventing or reducing anxiety or depression in youth aged 14-24 years. METHODS: A systematic search was conducted of the academic (PubMed/MEDLINE, PsycINFO, EMBASE) and grey literature. We also consulted two SOP experts and an Australian and Indian youth advisory group with lived experience of anxiety and/or depression. Consultations focused on the feasibility and acceptability of reviewed interventions. RESULTS: The search identified 25 studies reporting on 4408 participants from six countries (64.0 % of studies in the US). Multi-component interventions targeting several SOP components (i.e., value clarification, goal setting, gratitude enhancement) reported, on average, moderate reductions in depression and anxiety symptoms in youth. Interventions were generally more effective at reducing depression than anxiety symptoms. In terms of sub-populations or groups, there was some evidence for greater intervention effectiveness among youth with prior therapy experience, extraverted personalities, and those with already elevated anxiety/depression symptoms. Youth advisors and experts opined that group interventions were most acceptable to young people. LIMITATIONS: This review was limited to a recent 10-year timeframe and publications in English, potentially excluding relevant studies published prior to 2011 or in other languages. CONCLUSIONS: Fostering SOP can lead to better psychological wellbeing in youth. Potential harms resulting from interventions can occur without adequate consideration for a person's readiness for purpose discovery, environmental barriers, and familial and cultural settings. Further research in more diverse populations is required to determine who benefits and in what contexts.

Comparing the impact of high versus low lockdown severity on the mental health of young people in Australia during the COVID-19 pandemic.

Young Australians have been differentially affected by lockdowns and social restrictions during the COVID-19 pandemic. This study compared the mental health impacts of the COVID-19 pandemic and associated restrictions for young people in two Australian states, Victoria and Queensland, with Victoria experiencing more days in lockdown and greater infection rates. An online survey was completed between 01/04/2021 and 31/07/2021 by 687 young people, aged 16 to 24 years; 337 from Victoria and 350 from Queensland. Levels of negative emotion feelings (as measured by the Depression Anxiety Stress Scale), and COVID-19 risk factors for negative emotions (such as financial hardship, education disruption, loneliness and household conflict), as well as protective factors (resilience and self-esteem) were compared between the Victorian and Queensland samples, also considering some early pandemic data and pre-pandemic norms. No significant differences in negative emotions were found between young people living in the two states, despite substantial differences in pandemic restrictions. The results indicated that young people in Queensland and Victoria had experienced similarly high levels of negative emotions, at levels also seen at the start of the pandemic in Victoria. This is of grave concern, requiring urgent attention as the pandemic continues.

Long-acting injectable buprenorphine for opioid use disorder: A systematic review of impact of use on social determinants of health.

OBJECTIVES: This systematic review synthesizes evidence on both the effects and perspectives of the use of novel long-acting injectable buprenorphine (LAIB) as part of medication-assisted treatment (MAT) and its impact on social determinants of health (SDH), specifically abstinence, accessibility, employment, forensic matters, and gender and social relationships via a framework approach. METHODS: The study team searched three databases between January 2010 and June 2020 to identify English-language original research published in peer reviewed journals. This search yielded 9253 papers. A comprehensive search followed by 67 full text publication screenings by two independent reviewers yielded 15 papers meeting inclusion criteria. The study included three randomized control trials, one open label safety study, two case series, and six qualitative papers examining patient perspectives toward the LAIB prior to use. The team assessed the quality of studies via standardized quality assessment tools. RESULTS: The LAIB was positively associated with improvements in abstinence, accessibility, employment, social relationships, and forensic matters. Limited evidence exists on gender equity within the current literature. The qualitative papers highlighted the importance of patients' preferences and individualization of treatment planning to ensure the success of MAT. CONCLUSION: The quality of evidence was rated as medium or high risk of bias, which does limit interpretation of the results. Overall, the LAIB was positively associated with SDH and should be offered as part of MAT in alignment with the recovery model. Future research should evaluate the implementation and longitudinal impacts of LAI buprenorphine compared to treatment as usual (TAU).

The association between birth by caesarean section at term and offspring cognitive and academic performance: A birth cohort study.

BACKGROUND: Caesarean section (CS) is associated with an increased risk of adverse health outcomes for both mothers and offspring. The evidence for an association between CS and reduced offspring cognitive and academic performance has been inconsistent, with considerable limitations. AIM: The aim of this study is to compare cognitive and academic performance in childhood and early adulthood in offspring delivered by CS with those delivered vaginally at term. MATERIALS AND METHODS: Data on 4327 mothers and offspring from a longitudinal birth cohort study were analysed. Offspring cognitive performance was measured by the Picture Peabody Vocabulary Test-Revised (PPVT-R) at ages five and 21 and the Raven's Standard Progressive Matrices at age 14. Academic achievement was assessed using the Wide Range Achievement Test at age 14. RESULTS: After adjustment for confounding factors, there was no statistically significant association between cognitive performance and offspring birth mode at age five (P = 0.11). The adjusted difference of mean scores at five years on the PPVT-R for elective CS birth compared to those born by vaginal delivery was -2.2 (95% confidence interval (CI) -4.3 to -0.2), whereas for emergency CS it was 0.0 (95% CI -2.0 to 2.0). There were no differences in cognitive or academic performance at ages 14 and 21. CONCLUSION: Birth mode was not significantly associated with offspring cognitive or academic performance. Our study does not support concerns that CS is associated with a reduction in cognitive performance.

Monitoring of metabolic side-effects in children and adolescents prescribed antipsychotic medication: A systematic review.

OBJECTIVES: Prescribing antipsychotic medications to children and adolescents with severe mental and developmental disorders is common; however, there is a lack of consensus on appropriate metabolic monitoring for this population. This review systematically evaluates studies examining metabolic monitoring of children and adolescents prescribed antipsychotic medication to understand the clinical practice of metabolic monitoring and identify opportunities to improve the safety of antipsychotic prescribing in this population. METHODS: A systematic search for original research on metabolic monitoring in children and adolescents prescribed antipsychotics was conducted in six databases (PubMed, EMBASE, PsycINFO, The Cochrane Library [Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials, CENTRAL], Cochrane Methodology Register and Web of Science [Science and Social Science Citation Index]) from inception to February 2020 following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Studies were assessed for quality and findings summarised using narrative synthesis. RESULTS: Fifteen papers were identified. Studies agreed on the need for metabolic monitoring; however, there was a gap between guideline-recommended practice and clinical practice. Variable rates of baseline and subsequent monitoring were reported for both physical and biochemical parameters, with particularly low rates for monitoring requiring venesection. Younger age was also associated with lower monitoring rates. Implementation of quality improvement activities (new guidelines, staff education and checklists) improved monitoring rates although the measurement of biochemical parameters still occurred in only a minority of children. CONCLUSION: Despite widespread awareness and concern regarding metabolic side-effects, monitoring occurred inconsistently and infrequently, particularly for biochemical parameters requiring venesection. Monitoring of anthropometric measures (weight, body mass index and waist circumference) with escalation to more laboratory testing where metabolic concerns are identified may improve monitoring. Minimising iatrogenic harm, through reduced antipsychotic prescription where possible, is a clinical priority in this population.

The association of birth by caesarean section and cognitive outcomes in offspring: a systematic review.

PURPOSE: Studies have reported children born by caesarean section are more likely to have lower cognitive outcomes compared to those born by vaginal delivery. This paper reviews the literature examining caesarean birth and offspring cognitive outcomes. METHODS: A systematic search for observational studies or case-control studies that compared cognitive outcomes of people born by caesarean section with those born by vaginal delivery was conducted in six databases (Medline, PubMed, EMBASE, PsychInfo, CINAHL, Web of Science) from inception until December 2019 according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Studies were assessed for quality and a narrative synthesis was undertaken considering the evidence for a causal relationship according to the Bradford Hill Criteria. RESULTS: A total of seven studies were identified. Of these, four found a significant association between elective and emergency caesarean birth and reduction in offspring cognitive performance as measured by school performance or validated cognitive testing. Three studies found no association. There was variability in the quality of the studies, assessment of the reason for caesarean section (emergency vs elective), measurement of outcomes and adjustment for confounding factors. CONCLUSION: The evidence of an association between CS birth and lower offspring cognitive functioning is inconsistent. Based on currently available data, there is no evidence that a causal association exists. To better examine this association, future studies should (a) distinguish elective and emergency caesareans, (b) adequately adjust for confounding variables and (c) have valid outcome measures of cognition.

A comprehensive functional analysis of tissue specificity of human gene expression.

BACKGROUND: In recent years, the maturation of microarray technology has allowed the genome-wide analysis of gene expression patterns to identify tissue-specific and ubiquitously expressed ('housekeeping') genes. We have performed a functional and topological analysis of housekeeping and tissue-specific networks to identify universally necessary biological processes, and those unique to or characteristic of particular tissues. RESULTS: We measured whole genome expression in 31 human tissues, identifying 2374 housekeeping genes expressed in all tissues, and genes uniquely expressed in each tissue. Comprehensive functional analysis showed that the housekeeping set is substantially larger than previously thought, and is enriched with vital processes such as oxidative phosphorylation, ubiquitin-dependent proteolysis, translation and energy metabolism. Network topology of the housekeeping network was characterized by higher connectivity and shorter paths between the proteins than the global network. Ontology enrichment scoring and network topology of tissue-specific genes were consistent with each tissue's function and expression patterns clustered together in accordance with tissue origin. Tissue-specific genes were twice as likely as housekeeping genes to be drug targets, allowing the identification of tissue 'signature networks' that will facilitate the discovery of new therapeutic targets and biomarkers of tissue-targeted diseases. CONCLUSION: A comprehensive functional analysis of housekeeping and tissue-specific genes showed that the biological function of housekeeping and tissue-specific genes was consistent with tissue origin. Network analysis revealed that tissue-specific networks have distinct network properties related to each tissue's function. Tissue 'signature networks' promise to be a rich source of targets and biomarkers for disease treatment and diagnosis.

Gene expression signature in peripheral blood detects thoracic aortic aneurysm.

BACKGROUND: Thoracic aortic aneurysm (TAA) is usually asymptomatic and associated with high mortality. Adverse clinical outcome of TAA is preventable by elective surgical repair; however, identifying at-risk individuals is difficult. We hypothesized that gene expression patterns in peripheral blood cells may correlate with TAA disease status. Our goal was to identify a distinct gene expression signature in peripheral blood that may identify individuals at risk for TAA. METHODS AND FINDINGS: Whole genome gene expression profiles from 94 peripheral blood samples (collected from 58 individuals with TAA and 36 controls) were analyzed. Significance Analysis of Microarray (SAM) identified potential signature genes characterizing TAA vs. normal, ascending vs. descending TAA, and sporadic vs. familial TAA. Using a training set containing 36 TAA patients and 25 controls, a 41-gene classification model was constructed for detecting TAA status and an overall accuracy of 78+/-6% was achieved. Testing this classifier on an independent validation set containing 22 TAA samples and 11 controls yielded an overall classification accuracy of 78%. These 41 classifier genes were further validated by TaqMan real-time PCR assays. Classification based on the TaqMan data replicated the microarray results and achieved 80% classification accuracy on the testing set. CONCLUSIONS: This study identified informative gene expression signatures in peripheral blood cells that can characterize TAA status and subtypes of TAA. Moreover, a 41-gene classifier based on expression signature can identify TAA patients with high accuracy. The transcriptional programs in peripheral blood leading to the identification of these markers also provide insights into the mechanism of development of aortic aneurysms and highlight potential targets for therapeutic intervention. The classifier genes identified in this study, and validated by TaqMan real-time PCR, define a set of promising potential diagnostic markers, setting the stage for a blood-based gene expression test to facilitate early detection of TAA.

Defining embryonic stem cell identity using differentiation-related microRNAs and their potential targets.

Defining the identity of embryonic stem (ES) cells in quantitative molecular terms is a prerequisite to understanding their functional characteristics. Little is known about the role of microRNAs (miRNAs) in the regulation of ES cell identity. Statistical analysis of miRNA expression revealed unique expression signatures that could definitively classify mouse ES (mES), embryoid bodies (mEB), and somatic tissues. Analysis of these data sets also provides further confirmation of the nonrestrictive expression of miRNAs during murine development. Using combined genome-wide expression analyses of both miRNAs and mRNAs, we observed both negative and positive correlations in gene expression between miRNAs and their predicted targets. ES-specific miRNAs were positively correlated with their predicted targets, suggesting that mES-specific miRNAs may have a different role or mechanism in regulating their targets in mES maintenance or differentiation. The concept of cellular identity has changed with technology; this study redefines cellular identity by a generic statistical method of known dimension.

Large scale real-time PCR validation on gene expression measurements from two commercial long-oligonucleotide microarrays.

BACKGROUND: DNA microarrays are rapidly becoming a fundamental tool in discovery-based genomic and biomedical research. However, the reliability of the microarray results is being challenged due to the existence of different technologies and non-standard methods of data analysis and interpretation. In the absence of a "gold standard"/"reference method" for the gene expression measurements, studies evaluating and comparing the performance of various microarray platforms have often yielded subjective and conflicting conclusions. To address this issue we have conducted a large scale TaqMan Gene Expression Assay based real-time PCR experiment and used this data set as the reference to evaluate the performance of two representative commercial microarray platforms. RESULTS: In this study, we analyzed the gene expression profiles of three human tissues: brain, lung, liver and one universal human reference sample (UHR) using two representative commercial long-oligonucleotide microarray platforms: (1) Applied Biosystems Human Genome Survey Microarrays (based on single-color detection); (2) Agilent Whole Human Genome Oligo Microarrays (based on two-color detection). 1,375 genes represented by both microarray platforms and spanning a wide dynamic range in gene expression levels, were selected for TaqMan Gene Expression Assay based real-time PCR validation. For each platform, four technical replicates were performed on the same total RNA samples according to each manufacturer's standard protocols. For Agilent arrays, comparative hybridization was performed using incorporation of Cy5 for brain/lung/liver RNA and Cy3 for UHR RNA (common reference). Using the TaqMan Gene Expression Assay based real-time PCR data set as the reference set, the performance of the two microarray platforms was evaluated focusing on the following criteria: (1) Sensitivity and accuracy in detection of expression; (2) Fold change correlation with real-time PCR data in pair-wise tissues as well as in gene expression profiles determined across all tissues; (3) Sensitivity and accuracy in detection of differential expression. CONCLUSION: Our study provides one of the largest "reference" data set of gene expression measurements using TaqMan Gene Expression Assay based real-time PCR technology. This data set allowed us to use an alternative gene expression technology to evaluate the performance of different microarray platforms. We conclude that microarrays are indeed invaluable discovery tools with acceptable reliability for genome-wide gene expression screening, though validation of putative changes in gene expression remains advisable. Our study also characterizes the limitations of microarrays; understanding these limitations will enable researchers to more effectively evaluate microarray results in a more cautious and appropriate manner.

Regulation of various genes in human leukocytes acutely exposed to morphine: expression microarray analysis.

BACKGROUND: Previous studies from our laboratory have identified a novel mu opiate receptor micro(3), which is expressed in several different cell types and tissues including human vascular endothelial cells, leukocytes and neural tissues. This novel micro receptor is selective for the opiate alkaloid morphine, since this receptor does not bind other opioid peptides. MATERIAL/METHODS: This report details the acute affects of morphine exposure (1 microg/ml) to human leukocytes by analyzing gene expression using microarrays (Applied Biosystems). Robust estimation of the median fold change was used to identify candidates for significantly differentially expressed genes. An independent experiment using four same sample arrays was used to test the algorithm and to confirm the calculated percentage of falsely significant genes. RESULTS: Data obtained from this study demonstrate that acute morphine exposure differentially affected genes that are involved in immune function, signal transduction, cell adhesion, and apoptosis. CONCLUSIONS: Acute morphine exposure to human leukocytes results in specific and significant alterations in gene expression.

Inactivation of Kex2p diminishes the virulence of Candida albicans.

Deletion of the kexin gene (KEX2) in Candida albicans has a pleiotropic effect on phenotype and virulence due partly to a defect in the expression of two major virulence factors: the secretion of active aspartyl proteinases and the formation of hyphae. kex2/kex2 mutants are highly attenuated in a mouse systemic infection model and persist within cultured macrophages for at least 24 h without causing damage. Pathology is modest, with little disruption of kidney matrix. The infecting mutant cells are largely confined to glomeruli, and are aberrant in morphology. The complex phenotype of the deletion mutants reflects a role for kexin in a wide range of cellular processes. Taking advantage of the specificity of Kex2p cleavage, an algorithm we developed to scan the 9168 open reading frames in Assembly 6 of the C. albicans genome identified 147 potential substrates of Kex2p. These include all previously identified substrates, including eight secreted aspartyl proteinases, the exoglucanase Xog1p, the immunodominant antigen Mp65, and the adhesin Hwp1p. Other putative Kex2p substrates identified include several adhesins, cell wall proteins, and hydrolases previously not implicated in pathogenesis. Kexins also process fungal mating pheromones; a modification of the algorithm identified a putative mating pheromone with structural similarities to Saccharomyces cerevisiae alpha-factor.

A Trypanosoma brucei protein complex that binds G-overhangs and co-purifies with telomerase activity.

The chromosomal ends of Trypanosoma brucei, like those of most eukaryotes, contain conserved 5'-TTAGGG-3' repeated sequences and are maintained by the action of telomerase. Fractionated T. brucei cell extracts with telomerase activity were used as a source of potential regulatory factors or telomerase-associated components that might interact with T. brucei telomeres. Electrophoretic mobility shift assays and UV cross-linking were used to detect possible single-stranded telomeric protein.DNA complexes and to estimate the approximate size of the protein constituents. Three single-stranded telomeric protein.DNA complexes were observed. Complex C3 was highly specific for the G-strand telomeric repeat sequence and shares biochemical characteristics with G-rich, single-stranded telomeric binding proteins and with components of the telomerase holoenzyme described in yeast, ciliates, and humans. Susceptibility to RNase A or chemical nuclease (hydroxyl radical) pre-treatment showed that complex C3 was tightly associated with an RNA component. Matrix-assisted laser desorption/ionization-time of flight mass spectrometry was used to estimate the molecular mass of the peptides obtained by in-gel Lys-C digestion of low abundance C3-associated proteins. The molecular masses of the peptides showed no homologies with other proteins from trypanosomes or with any protein in the data bases screened.