Urinary extracellular vesicles as a source of protein-based biomarkers in feline chronic kidney disease and hypertension.

OBJECTIVES: To validate a methodology for isolating feline urinary extracellular vesicles and characterise the urinary extracellular vesicle population and proteome in cats with normal renal function and cats with normotensive or hypertensive chronic kidney disease. METHODS: Feline urinary extracellular vesicles were isolated using three different methods (precipitation alone, precipitation followed by size exclusion chromatography and ultrafiltration followed by size exclusion chromatography, which were compared via transmission electron microscopy and nanoparticle tracking analysis. Cats with normal renal function (n=9), normotensive chronic kidney disease (n=10) and hypertensive chronic kidney disease (n=9) were identified and urinary extracellular vesicles isolated from patient urine samples via ultrafiltration followed by size exclusion chromatography. Extracellular vesicle size and concentration were determined using nanoparticle tracking analysis, and subsequently underwent proteomic analysis using liquid chromatography with tandem mass spectrometry to identify differences in protein expression between categories. RESULTS: Urinary extracellular vesicle preparations contained particles of the expected size and morphology, and those obtained by ultrafiltration + size exclusion chromatography had a significantly higher purity (highest particle: protein ratio). The urinary extracellular vesicle proteomes contained extracellular vesicle markers and proteins originating from all nephron segments. Urinary extracellular vesicle concentration and size were unaffected by renal disease or hypertension. There were no differentially expressed proteins detected when comparing urinary extracellular vesicles derived from cats in the healthy category with the combined chronic kidney disease category, but five differentially expressed proteins were identified between the normotensive chronic kidney disease and hypertensive chronic kidney disease categories. CLINICAL SIGNIFICANCE: Feline urinary extracellular vesicles can be successfully isolated from stored urine samples. Differentially expressed urinary extracellular vesicle proteins were discovered in cats with hypertensive chronic kidney disease, and warrant further investigation into their utility as biomarkers or therapeutic targets.

Polygenic risk score and heritability estimates reveals a genetic relationship between ASD and OCD.

Obsessive-compulsive disorder (OCD) and Autism spectrum disorder (ASD) are both highly heritable neurodevelopmental disorders that conceivably share genetic risk factors. However, the underlying genetic determinants remain largely unknown. In this work, the authors describe a combined genome-wide association study (GWAS) of ASD and OCD. The OCD dataset includes 2998 individuals in nuclear families. The ASD dataset includes 6898 individuals in case-parents trios. GWAS summary statistics were examined for potential enrichment of functional variants associated with gene expression levels in brain regions. The top ranked SNP is rs4785741 (chromosome 16) with P value=6.9×10-7 in our re-analysis. Polygenic risk score analyses were conducted to investigate the genetic relationship within and across the two disorders. These analyses identified a significant polygenic component of ASD, predicting 0.11% of the phenotypic variance in an independent OCD data set. In addition, we examined the genomic architecture of ASD and OCD by estimating heritability on different chromosomes and different allele frequencies, analyzing genome-wide common variant data by using the Genome-wide Complex Trait Analysis (GCTA) program. The estimated global heritability of OCD is 0.427 (se=0.093) and 0.174 (se=0.053) for ASD in these imputed data.

Microbiological risk assessment for personal care products.

Regulatory decisions regarding microbiological safety of cosmetics and personal care products are primarily hazard-based, where the presence of a potential pathogen determines decision-making. This contrasts with the Food industry where it is a commonplace to use a risk-based approach for ensuring microbiological safety. A risk-based approach allows consideration of the degree of exposure to assess unacceptable health risks. As there can be a number of advantages in using a risk-based approach to safety, this study explores the Codex Alimentarius (Codex) four-step Microbiological Risk Assessment (MRA) framework frequently used in the Food industry and examines how it can be applied to the safety assessment of personal care products. The hazard identification and hazard characterization steps (one and two) of the Codex MRA framework consider the main microorganisms of concern. These are addressed by reviewing the current industry guidelines for objectionable organisms and analysing reports of contaminated products notified by government agencies over a recent 5-year period, together with examples of reported outbreaks. Data related to estimation of exposure (step three) are discussed, and examples of possible calculations and references are included. The fourth step, performed by the risk assessor (risk characterization), is specific to each assessment and brings together the information from the first three steps to assess the risk. Although there are very few documented uses of the MRA approach for personal care products, this study illustrates that it is a practicable and sound approach for producing products that are safe by design. It can be helpful in the context of designing products and processes going to market and with setting of microbiological specifications. Additionally, it can be applied reactively to facilitate decision-making when contaminated products are released on to the marketplace. Currently, the knowledge available may only allow a qualitative or semi-quantitative rather than fully quantitative risk assessment, but an added benefit is that the disciplined structuring of available knowledge enables clear identification of gaps to target resources and if appropriate, instigate data generation.

Whole-genome association analysis of treatment response in obsessive-compulsive disorder.

Up to 30% of patients with obsessive-compulsive disorder (OCD) exhibit an inadequate response to serotonin reuptake inhibitors (SRIs). To date, genetic predictors of OCD treatment response have not been systematically investigated using genome-wide association study (GWAS). To identify specific genetic variations potentially influencing SRI response, we conducted a GWAS study in 804 OCD patients with information on SRI response. SRI response was classified as 'response' (n=514) or 'non-response' (n=290), based on self-report. We used the more powerful Quasi-Likelihood Score Test (the MQLS test) to conduct a genome-wide association test correcting for relatedness, and then used an adjusted logistic model to evaluate the effect size of the variants in probands. The top single-nucleotide polymorphism (SNP) was rs17162912 (P=1.76 × 10(-8)), which is near the DISP1 gene on 1q41-q42, a microdeletion region implicated in neurological development. The other six SNPs showing suggestive evidence of association (P<10(-5)) were rs9303380, rs12437601, rs16988159, rs7676822, rs1911877 and rs723815. Among them, two SNPs in strong linkage disequilibrium, rs7676822 and rs1911877, located near the PCDH10 gene, gave P-values of 2.86 × 10(-6) and 8.41 × 10(-6), respectively. The other 35 variations with signals of potential significance (P<10(-4)) involve multiple genes expressed in the brain, including GRIN2B, PCDH10 and GPC6. Our enrichment analysis indicated suggestive roles of genes in the glutamatergic neurotransmission system (false discovery rate (FDR)=0.0097) and the serotonergic system (FDR=0.0213). Although the results presented may provide new insights into genetic mechanisms underlying treatment response in OCD, studies with larger sample sizes and detailed information on drug dosage and treatment duration are needed.

Genome-wide association study in obsessive-compulsive disorder: results from the OCGAS.

Obsessive-compulsive disorder (OCD) is a psychiatric condition characterized by intrusive thoughts and urges and repetitive, intentional behaviors that cause significant distress and impair functioning. The OCD Collaborative Genetics Association Study (OCGAS) is comprised of comprehensively assessed OCD patients with an early age of OCD onset. After application of a stringent quality control protocol, a total of 1065 families (containing 1406 patients with OCD), combined with population-based samples (resulting in a total sample of 5061 individuals), were studied. An integrative analyses pipeline was utilized, involving association testing at single-nucleotide polymorphism (SNP) and gene levels (via a hybrid approach that allowed for combined analyses of the family- and population-based data). The smallest P-value was observed for a marker on chromosome 9 (near PTPRD, P=4.13 × 10(-)(7)). Pre-synaptic PTPRD promotes the differentiation of glutamatergic synapses and interacts with SLITRK3. Together, both proteins selectively regulate the development of inhibitory GABAergic synapses. Although no SNPs were identified as associated with OCD at genome-wide significance level, follow-up analyses of genome-wide association study (GWAS) signals from a previously published OCD study identified significant enrichment (P=0.0176). Secondary analyses of high-confidence interaction partners of DLGAP1 and GRIK2 (both showing evidence for association in our follow-up and the original GWAS study) revealed a trend of association (P=0.075) for a set of genes such as NEUROD6, SV2A, GRIA4, SLC1A2 and PTPRD. Analyses at the gene level revealed association of IQCK and C16orf88 (both P<1 × 10(-)(6), experiment-wide significant), as well as OFCC1 (P=6.29 × 10(-)(5)). The suggestive findings in this study await replication in larger samples.

Evaluating a unique, specialist psychiatric genetic counseling clinic: uptake and impact.

People with psychiatric disorders and their family members have expressed interest in receiving genetic counseling (GC). In February 2012, we opened the first (to our knowledge) specialist psychiatric GC clinic of its kind, for individuals with non-syndromic psychiatric disorders and their families. Prior to GC and at a standard 1-month follow-up session, clinical assessment tools are completed, specifically, the GC outcomes scale (GCOS, which measures empowerment, completed by all clients) and the Illness Management Self Efficacy scale (IMSES, completed by those with mental illness). Consecutive English-speaking clients attending the clinic between 1 February 2012 and 31 January 2013 who were capable of consenting were asked for permission to use their de-identified clinical data for research purposes. Descriptive analyses were conducted to ascertain demographic details of attendees, and paired sample t-tests were conducted to assess changes in GCOS and IMSES scores from pre- to post-GC. Of 143 clients, seven were unable to consent, and 75/136 (55.1%) consented. Most were female (85.3%), self-referred (76%), and had personal experience of mental illness (65.3%). Mean GCOS and IMSES scores increased significantly after GC (p < 0.0001 and p = 0.011, respectively). In a naturalistic setting, GC increases empowerment and self-efficacy in this population.

Mouse granzyme A induces a novel death with writhing morphology that is mechanistically distinct from granzyme B-induced apoptosis.

Human and mouse granzyme (Gzm)B both induce target cell apoptosis in concert with pore-forming perforin (Pfp); however the mechanisms by which other Gzms induce non-apoptotic death remain controversial and poorly characterised. We used timelapse microscopy to document, quantitatively and in real time, the death of target cells exposed to primary natural killer (NK) cells from mice deficient in key Gzms. We found that in the vast majority of cases, NK cells from wild-type mice induced classic apoptosis. However, NK cells from syngeneic Gzm B-deficient mice induced a novel form of cell death characterised by slower kinetics and a pronounced, writhing, 'worm-like' morphology. Dying cells initially contracted but did not undergo membrane blebbing, and annexin-V staining was delayed until the onset of secondary necrosis. As it is different from any cell death process previously reported, we tentatively termed this cell death 'athetosis'. Two independent lines of evidence showed this alternate form of death was due to Gzm A: first, cell death was revealed in the absence of Gzm B, but was completely lost when the NK cells were deficient in both Gzm A and B; second, the athetotic morphology was precisely reproduced when recombinant mouse Gzm A was delivered by an otherwise innocuous dose of recombinant Pfp. Gzm A-mediated athetosis did not require caspase activation, early mitochondrial disruption or generation of reactive oxygen species, but did require an intact actin cytoskeleton and was abolished by latrunculin B and mycalolide B. This work defines an authentic role for mouse Gzm A in granule-induced cell death by cytotoxic lymphocytes.

Meta-analysis of association between obsessive-compulsive disorder and the 3' region of neuronal glutamate transporter gene SLC1A1.

The neuronal glutamate transporter gene SLC1A1 is a candidate gene for obsessive-compulsive disorder (OCD) based on linkage studies and convergent evidence implicating glutamate in OCD etiology. The 3' end of SLC1A1 is the only genomic region with consistently demonstrated OCD association, especially when analyzing male-only probands. However, specific allele associations have not been consistently replicated, and recent OCD genome-wide association and meta-analysis studies have not incorporated all previously associated SLC1A1 SNPs. To clarify the nature of association between SLC1A1 and OCD, pooled analysis was performed on all available relevant raw study data, comprising a final sample of 815 trios, 306 cases and 634 controls. This revealed weak association between OCD and one of nine tested SLC1A1 polymorphisms (rs301443; uncorrected P = 0.046; non-significant corrected P). Secondary analyses of male-affecteds only (N = 358 trios and 133 cases) demonstrated modest association between OCD and a different SNP (rs12682807; uncorrected P = 0.012; non-significant corrected P). Findings of this meta-analysis are consistent with the trend of previous candidate gene studies in psychiatry and do not clarify the putative role of SLC1A1 in OCD pathophysiology. Nonetheless, it may be important to further examine the potential associations demonstrated in this amalgamated sample, especially since the SNPs with modest associations were not included in the more highly powered recent GWAS or in a past meta-analysis including five SLC1A1 polymorphisms. This study underscores the need for much larger sample sizes in future genetic association studies and suggests that next-generation sequencing may be beneficial in examining the potential role of rare variants in OCD.

Genome-wide association study of obsessive-compulsive disorder.

Obsessive-compulsive disorder (OCD) is a common, debilitating neuropsychiatric illness with complex genetic etiology. The International OCD Foundation Genetics Collaborative (IOCDF-GC) is a multi-national collaboration established to discover the genetic variation predisposing to OCD. A set of individuals affected with DSM-IV OCD, a subset of their parents, and unselected controls, were genotyped with several different Illumina SNP microarrays. After extensive data cleaning, 1465 cases, 5557 ancestry-matched controls and 400 complete trios remained, with a common set of 469,410 autosomal and 9657 X-chromosome single nucleotide polymorphisms (SNPs). Ancestry-stratified case-control association analyses were conducted for three genetically-defined subpopulations and combined in two meta-analyses, with and without the trio-based analysis. In the case-control analysis, the lowest two P-values were located within DLGAP1 (P=2.49 × 10(-6) and P=3.44 × 10(-6)), a member of the neuronal postsynaptic density complex. In the trio analysis, rs6131295, near BTBD3, exceeded the genome-wide significance threshold with a P-value=3.84 × 10(-8). However, when trios were meta-analyzed with the case-control samples, the P-value for this variant was 3.62 × 10(-5), losing genome-wide significance. Although no SNPs were identified to be associated with OCD at a genome-wide significant level in the combined trio-case-control sample, a significant enrichment of methylation QTLs (P<0.001) and frontal lobe expression quantitative trait loci (eQTLs) (P=0.001) was observed within the top-ranked SNPs (P<0.01) from the trio-case-control analysis, suggesting these top signals may have a broad role in gene expression in the brain, and possibly in the etiology of OCD.

Genome-wide association study of Tourette's syndrome.

Tourette's syndrome (TS) is a developmental disorder that has one of the highest familial recurrence rates among neuropsychiatric diseases with complex inheritance. However, the identification of definitive TS susceptibility genes remains elusive. Here, we report the first genome-wide association study (GWAS) of TS in 1285 cases and 4964 ancestry-matched controls of European ancestry, including two European-derived population isolates, Ashkenazi Jews from North America and Israel and French Canadians from Quebec, Canada. In a primary meta-analysis of GWAS data from these European ancestry samples, no markers achieved a genome-wide threshold of significance (P<5 × 10(-8)); the top signal was found in rs7868992 on chromosome 9q32 within COL27A1 (P=1.85 × 10(-6)). A secondary analysis including an additional 211 cases and 285 controls from two closely related Latin American population isolates from the Central Valley of Costa Rica and Antioquia, Colombia also identified rs7868992 as the top signal (P=3.6 × 10(-7) for the combined sample of 1496 cases and 5249 controls following imputation with 1000 Genomes data). This study lays the groundwork for the eventual identification of common TS susceptibility variants in larger cohorts and helps to provide a more complete understanding of the full genetic architecture of this disorder.

The EBV-encoded latent membrane proteins, LMP2A and LMP2B, limit the actions of interferon by targeting interferon receptors for degradation.

Although frequently expressed in Epstein-Barr virus (EBV)-positive malignancies, the role that latent membrane protein 2A and 2B (LMP2A and LMP2B) have in the oncogenic process remains obscure. Here we show a novel function for these proteins in epithelial cells, namely, their ability to modulate signalling from type I/II interferon receptors (IFNRs). We show that LMP2A- and LMP2B-expressing epithelial cells show decreased responsiveness to interferon (IFN)alpha and IFNgamma, as assessed by STAT1 phosphorylation, ISGF3 and GAF-mediated binding to IFN-stimulated response element and IFNgamma-activated factor sequence elements and luciferase reporter activation. Transcriptional profiling highlighted the extent of this modulation, with both viral proteins impacting 'globally' on IFN-stimulated gene expression. Although not affecting the levels of cell-surface IFNRs, LMP2A and LMP2B accelerated the turnover of IFNRs through processes requiring endosome acidification. This function may form part of EBV's strategy to limit anti-viral responses and define a novel function for LMP2A and LMP2B in modulating signalling from receptors that participate in innate immune responses.

Epstein-Barr virus-encoded EBNA1 regulates cellular gene transcription and modulates the STAT1 and TGFbeta signaling pathways.

The Epstein-Barr virus (EBV)-encoded EBNA1 protein is expressed in all virus-associated tumors where it plays an essential role in the maintenance, replication and transcription of the EBV genome. Transcriptional profiling of EBNA1-expressing carcinoma cells demonstrated that EBNA1 also influences the expression of a range of cellular genes including those involved in translation, transcription and cell signaling. Of particular interest was the ability of EBNA1 to enhance expression of STAT1 and sensitize cells to interferon-induced STAT1 activation with resultant enhancement of major histocompatibility complex expression. A negative effect of EBNA1 on the expression of TGFbeta1-responsive betaig-h3 and PAI-1 genes was confirmed at the protein level in EBV-infected carcinoma cells. This effect resulted from the ability of EBNA1 to repress TGFbeta1-induced transcription via a reduction in the interaction of SMAD2 with SMAD4. More detailed analysis revealed that EBNA1 induces a lower steady-state level of SMAD2 protein as a consequence of increased protein turnover. These data show that EBNA1 can influence cellular gene transcription resulting in effects that may contribute to the development of EBV-associated tumors.

Practice MRI: reducing the need for sedation and general anaesthesia in children undergoing MRI.

The aim of this study was to evaluate the effectiveness of a practice magnetic resonance unit, in preparing children to undergo magnetic resonance procedures without general anaesthesia (GA) or sedation. The records of children who attended the practice MRI between February 2002 and April 2004 were retrospectively reviewed. Each record was assessed as to whether the child had passed or failed the practice MRI intervention. Those children who were considered to have passed and were proceeded to a clinical non-GA MRI had the report of the clinical scan reviewed. If the scan had been reported as non-diagnostic because of movement artefact it was classified as a failed scan, otherwise it was considered a pass. One hundred and thirty-four children undertook a practice MRI (age range 4.1-16.1 years, median age 7.7 years, 47% boys) and 120/134 (90%) passed the practice session. In all, 117/120 (98%) subsequently had a clinical non-GA MRI and 110/117 (94%) passed (median age 7.8 years, 47% boys). Preparation is a safe and effective method to reduce the need for sedation and GA in children undergoing a clinical MRI scan. It provides a positive medical experience for children, parents and staff, and results in cost savings for the hospital.

Long-term outcome of pediatric obsessive-compulsive disorder: a meta-analysis and qualitative review of the literature.

OBJECTIVE: To review the extant literature on the long-term outcome of child/adolescent-onset obsessive-compulsive disorder (OCD). METHOD: Medline and Psychlit databases were systematically searched for articles regarding long-term outcomes of child/adolescent-onset OCD. Meta-analysis regression was applied to evaluate predictors and persistence of OCD. RESULTS: Sixteen study samples (n = 6-132; total = 521 participants) in 22 studies had follow-up periods ranging between 1 and 15.6 years. Pooled mean persistence rates were 41% for full OCD and 60% for full or subthreshold OCD. Earlier age of OCD onset (z = -3.26, P = 0.001), increased OCD duration (z = 2.22, P = 0.027) and in-patient vs. out-patient status (z = 2.94, P = 0.003) predicted greater persistence. Comorbid psychiatric illness and poor initial treatment response were poor prognostic factors. Although psychosocial function was frequently compromised, most studies lacked comprehensive outcome measures. CONCLUSION: Long-term persistence of pediatric OCD may be lower than believed. Future studies should include broader measures of outcome including symptomatic persistence and functional impairment in multiple domains.

Timing and magnitude of frontal activity differentiates refixation and anti-saccade performance.

EEG data were recorded while 10 subjects generated refixation saccades towards a visual target and antisaccades away from a visual cue. Theoretically, the same basic neural circuitry supports refixation and correct anti-saccade performances, with additional activity in primarily dorsolateral prefrontal cortex circuitry supporting antisaccade-associated inhibitory processes. Analyses demonstrated that sensory registration of visual stimuli is similar for refixation and anti-saccade conditions. Increased frontal brain activity at 5 and 15 Hz was observed preceding correct antisaccades when compared to refixation saccades. These analyses provide specific information suggesting that 160-60 ms before saccade generation is the critical period for response inhibition.

Suicidal children and adolescents with first emergency room presentations: predictors of six-month outcome.

OBJECTIVE: To examine risk of future documented suicide attempts and emergency room (ER) returns among children and adolescents with first suicidal ER presentations. METHOD: A total of 548 consecutive ER presentations of suicidal 5- to 19-year-olds to a Canadian center over a 1-year period (1997-1998) were reviewed. Relative risk analyses were performed on 224 first-time patients (mean age 14.6+/-2.1) to determine the strength of associations between predictors and outcomes (ER return and suicide attempts). RESULTS: At 6-month follow-up, 32.6% (n = 73) had returned to the ER, 24.1% (n = 54) had a documented suicide attempt, and 14.3% (n = 32) required psychiatric hospitalization. Predictors for both ER return and future documented suicide attempts included 15- to 19-year age range, past foster/group home placement, past mental health care, a suicide plan, reported mood symptoms, sobriety at ER visit, and general substance use. Child welfare guardianship and abuse history were also predictors of ER returns. CONCLUSIONS: Clinicians should be aware of these risk factors when assessing and managing suicidal youths with first ER presentations.

A convergent validity study of Cloninger's Temperament and Character Inventory with the Coolidge Axis II Inventory.

This study examined the convergent validity of the Temperament and Character Inventory (TCI), a measure of four biosocial temperaments and three character dimensions with the Coolidge Axis II Inventory (CATI), a measure of 14 personality disorders. A nonclinical sample of 163 college students was given both measures, and the data were analyzed with bivariate and multivariate statistics. Hypotheses generated from the findings of Svrakic, Whitehead, Przybeck, and Cloninger (1993, Archives of General Psychiatry, 50, 991-999) were confirmed for a majority of the relationships between the two measures. The preliminary results provide qualified support for the TCI and Cloninger's biosocial theory in the assessment of personality disorders.

Clinical and biochemical response following withdrawal of a long-acting, depot injection form of octreotide (Sandostatin-LAR).

OBJECTIVE: Monthly injections of Sandostatin-LAR have been shown to be an effective therapy for patients with acromegaly. Because of an ongoing need to assess a patients response to definitive therapy such as surgery and/or radiotherapy, we aimed to evaluate GH levels and acromegaly symptom scores in patients withdrawing from Sandostatin-LAR. DESIGN AND PATIENTS: 12 patients with acromegaly previously treated with Sandostatin-LAR, 20-40 mg intramuscularly every 28 (n = 9) or 42 (n = 3) days for 12-36 months were studied at monthly intervals for 4 months following the withdrawal of the drug. MEASUREMENTS: Hourly fasting serum GH measurements between 0800 h and 1200 h, serum IGF-1 and symptom scores were undertaken at 4, 8, 12 and 16 weeks following the last injection of Sandostatin-LAR. MRI/CT scans of the pituitary were undertaken at 16 weeks and compared to scans taken on Sandostatin-LAR within the previous 10 months. RESULTS: Serum GH rose progressively from 7.7 (1.5 to 14.6) (median (range)) mIU/l at 4 weeks to 9.9 (1.5-21.8), to 12.6 (4.9-31.9) (P < 0.05 vs 4 weeks) and to 13.1 (6.0-39.1) mIU/l (P < 0.002) at 8, 12 and 16 weeks, respectively, following cessation of Sandostatin-LAR. IGF-1 rose from 38.5 (12.6-73.8) nmol/l at 4 weeks to 62.4 (37.4-159) at 16 weeks (P < 0.002) and mean symptom score (comprising headache, sweating, arthralgia, paraesthesiae, tiredness) from 4.0 (0 to 10) (4 weeks) to 4.5 (0-9) (8 weeks) to 6.0 (2-10) (12 weeks) to 6.5 (4-12) (16 weeks, P < 0.05). Individual GH profiles indicated a rise in GH in 5/12 patients between weeks 4-8 and between weeks 8-12 in a further 5/12 patients. There were no changes in pituitary tumour size following discontinuation of Sandostatin-LAR. CONCLUSIONS: GH and symptom scores rise progressively following discontinuation of Sandostatin-LAR in acromegalic patients. However, GH and symptom scores remain suppressed in some patients for at least 8 weeks following cessation of Sandostatin-LAR. We suggest that a withdrawal period of 3 months from Sandostatin-LAR is required in order to perform a meaningful re-assessment of GH and clinical status.

Long-term therapy with long-acting octreotide (Sandostatin-LAR) for the management of acromegaly.

OBJECTIVES: To evaluate the efficacy and safety of a long-acting preparation of the somatostatin analogue octreotide, Sandostatin-LAR (SMS-LAR) for the treatment of acromegaly. DESIGN AND PATIENTS: Thirteen patients with acromegaly received intramuscular injections of SMS-LAR 20-40 mg at 4-6 week intervals for a period of up to 3 years. MEASUREMENTS: Serial measurement of serum GH and IGF concentrations were obtained. Symptoms related to acromegaly were scored by patients at baseline and following each injection. Serial gallbladder ultrasound and pituitary imaging was performed throughout the study. RESULTS: One patient was withdrawn from the study after 6 months because of continued gastrointestinal side effects; 4 patients were treated with monthly injections for 12 months and 8 patients with injections at either 1 month or 6-week intervals for 36 months; hence data is presented for n = 12 for up to 12 months; and thereafter n = 8. SMS-LAR significantly reduced serum GH and IGF-1 values: for the whole group GH concentrations fell from 24.8 +/- 4.2 mU/l (mean +/- SE) at baseline to 5.2 +/- 0.8 mU/l at 12 months (P < 0.01, n = 12). In the 8 patients treated for 3 years GH fell from 27.8 +/- 6.1 mU/l at baseline to 4.2 +/- 0.8 mU/l at the end of 3 years (P < 0.01, n = 8). GH fell to < 10 mU/l in all subjects and was < 5 mU/l in 50% after both 1 and 3 years. IGF-1 concentrations fell from 95 +/- 13 nmol/l at baseline to 63 +/- 13 nmol/l after 1 year (P < 0.01, n = 12; reference range < 65 nmol/l). In the 8 patients treated for 3 years IGF-1 concentrations fell from 119 +/- 14 nmol/l at baseline to 60 +/- 13 nmol/l after 3 years (P < 0.001, n = 8). IGF-1 was < 65 nmol/l in 60% of patients after 1 year and 75% after 3 years. Treatment resulted in trends towards improvement in symptoms of acromegaly and statistically significant improvement in sweating. There was no evidence of tachyphylaxis or evidence to suggest development of glucose intolerance. Only 2 patients (15%) developed gallbladder sludge which was asymptomatic; no patient developed gallstones. CONCLUSIONS: We conclude that SMS-LAR is a safe, effective and well tolerated treatment, making it an important therapeutic option in the management of acromegaly.