Chemotherapy-induced gut microbiome disruption, inflammation, and cognitive decline in female patients with breast cancer.

Chemotherapy is notorious for causing behavioral side effects (e.g., cognitive decline). Notably, the gut microbiome has recently been reported to communicate with the brain to affect behavior, including cognition. Thus, the aim of this clinical longitudinal observational study was to determine whether chemotherapy-induced disruption of the gut microbial community structure relates to cognitive decline and circulating inflammatory signals. Fecal samples, blood, and cognitive measures were collected from 77 patients with breast cancer before, during, and after chemotherapy. Chemotherapy altered the gut microbiome community structure and increased circulating TNF-α. Both the chemotherapy-induced changes in microbial relative abundance and decreased microbial diversity were related to elevated circulating pro-inflammatory cytokines TNF-α and IL-6. Participants reported subjective cognitive decline during chemotherapy, which was not related to changes in the gut microbiome or inflammatory markers. In contrast, a decrease in overall objective cognition was related to a decrease in microbial diversity, independent of circulating cytokines. Stratification of subjects, via a reliable change index based on 4 objective cognitive tests, identified objective cognitive decline in 35% of the subjects. Based on a differential microbial abundance analysis, those characterized by cognitive decline had unique taxonomic shifts (Faecalibacterium, Bacteroides, Fusicatenibacter, Erysipelotrichaceae UCG-003, and Subdoligranulum) over chemotherapy treatment compared to those without cognitive decline. Taken together, gut microbiome change was associated with cognitive decline during chemotherapy, independent of chemotherapy-induced inflammation. These results suggest that microbiome-related strategies may be useful for predicting and preventing behavioral side effects of chemotherapy.

Impulsivity and Treatment Outcomes in Individuals with Cocaine Use Disorder: Examining the Gap between Interest and Adherence.

Background: Impulsivity is implicated in the development and maintenance of Cocaine Use Disorder (CUD). Less work has examined impulsivity's role on interest in initiating treatment, treatment adherence, or treatment response. No pharmacotherapies are approved for CUD, so efforts to understand and bolster the effects of psychotherapy are important in guiding and refining treatment. The present study examined the impact of impulsivity on interest in treatment, treatment initiation, treatment adherence, and treatment outcomes in individuals with CUD. Methods: Following the completion of a larger study on impulsivity and CUD participants were offered 14 sessions of (12 weeks) Cognitive Behavioral Relapse Prevention (CBT-RP). Before starting treatment, participants completed seven self-report and four behavioral measures of impulsivity. Sixty-eight healthy adults (36% female) with CUD (aged 49.4 ± 7.9) expressed an interest in treatment. Results: Greater scores on several self-report measures of impulsivity, and fewer difficulties with delayed gratification were associated with increased interest in treatment in both males and females. 55 participants attended at least 1 treatment session, while 13 participants did attend a single session. Individuals who attended at least one treatment session scored lower on measures of lack of perseverance and procrastination. Still, measures of impulsivity did not reliably predict session attendance nor the frequency of cocaine-positive urine samples throughout treatment. Males attended nearly twice as many treatment sessions as females despite nonsignificant associations between impulsivity in males and the number of sessions attended. Conclusions: Greater impulsivity in individuals with CUD was associated with expressing an interest in treatment, but not treatment adherence or response.

EELS: Autonomous snake-like robot with task and motion planning capabilities for ice world exploration.

Ice worlds are at the forefront of astrobiological interest because of the evidence of subsurface oceans. Enceladus in particular is unique among the icy moons because there are known vent systems that are likely connected to a subsurface ocean, through which the ocean water is ejected to space. An existing study has shown that sending small robots into the vents and directly sampling the ocean water is likely possible. To enable such a mission, NASA's Jet Propulsion Laboratory is developing a snake-like robot called Exobiology Extant Life Surveyor (EELS) that can navigate Enceladus' extreme surface and descend an erupting vent to capture unaltered liquid samples and potentially reach the ocean. However, navigating to and through Enceladus' environment is challenging: Because of the limitations of existing orbital reconnaissance, there is substantial uncertainty with respect to its geometry and the physical properties of the surface/vents; communication is limited, which requires highly autonomous robots to execute the mission with limited human supervision. Here, we provide an overview of the EELS project and its development effort to create a risk-aware autonomous robot to navigate these extreme ice terrains/environments. We describe the robot's architecture and the technical challenges to navigate and sense the icy environment safely and effectively. We focus on the challenges related to surface mobility, task and motion planning under uncertainty, and risk quantification. We provide initial results on mobility and risk-aware task and motion planning from field tests and simulated scenarios.

AAV-encoded OTC activity persisting to adulthood following delivery to newborn spf(ash) mice is insufficient to prevent shRNA-induced hyperammonaemia.

Urea cycle defects presenting in the neonatal period with hyperammonaemia are associated with high morbidity and mortality, and necessitate liver transplantation for long-term management. Gene therapy is therefore an attractive possibility, with vectors based on adeno-associated virus (rAAV) currently showing exciting promise in liver-targeted clinical trials in adults. Successful use of rAAV vectors in infants, however, is more challenging as episomal rAAV genomes will be lost from proliferating hepatocytes during liver growth, leaving stable transgene expression dependent on the subset of vector genomes that undergo genomic integration. To explore this challenge, we exploited the partially ornithine transcarbamylase (OTC)-deficient spf(ash) mouse model and small hairpin RNA-mediated knockdown of residual endogenous OTC enzyme activity in adult mice that had received neonatal treatment with an OTC-encoding rAAV. This leaves mice reliant on vector-encoded OTC activity that has persisted from the newborn period. Despite stable transduction in approximately 8% of hepatocytes and residual vector-encoded OTC activity of up to 33% of wild-type, well above endogenous spf(ash) levels (5-7%), mice were not protected from hyperammonaemia. These data show that the distribution of OTC activity within the liver is critical and that rAAV vector re-delivery after early neonatal treatment is likely to be necessary for stable control of hyperammonaemia into adulthood.

Baker's yeast ß-glucan supplementation increases monocytes and cytokines post-exercise: implications for infection risk?

Strenuous aerobic exercise is known to weaken the immune system, and while many nutritional supplements have been proposed to boost post-exercise immunity, few are known to be effective. The purpose of the present study was to evaluate whether 10 d of supplementation with a defined source of baker's yeast ß-glucan (BG, Wellmune WGP®) could minimise post-exercise immunosuppression. Recreationally active men and women (n 60) completed two 10 d trial conditions using a cross-over design with a 7 d washout period: placebo (rice flour) and baker's yeast BG (250 mg/d of ß-1,3/1,6-glucans derived from Saccharomyces cerevisiae) before a bout of cycling (49 ± 6 min) in a hot (38 ± 2°C), humid (45 ± 2 % relative humidity) environment. Blood was collected at baseline (before supplement), pre- (PRE), post- (POST) and 2 h (2H) post-exercise. Total and subset monocyte concentration was measured by four-colour flow cytometry. Plasma cytokine levels and lipopolysaccharide (LPS)-stimulated cytokine production were measured using separate multiplex assays. Total (CD14⁺) and pro-inflammatory monocyte concentrations (CD14⁺/CD16⁺) were significantly greater at POST and 2H (P<0·05) with BG supplementation. BG supplementation boosted LPS-stimulated production of IL-2, IL-4, IL-5 and interferon-γ (IFN-γ) at PRE and POST (P<0·05). Plasma IL-4, IL-5 and IFN-γ concentrations were greater at 2H following BG supplementation. It appears that 10 d of supplementation with BG increased the potential of blood leucocytes for the production of IL-2, IL-4, IL-5 and IFN-γ. The key findings of the present study demonstrate that BG may have potential to alter immunity following a strenuous exercise session.

Interpersonal competence and sex risk behaviours among Jamaican adolescents.

OBJECTIVE: Of particular public health concern to the Jamaican authorities is the consistently high numbers of new HIV infections among adolescents and young adults. The thrust in HIV/AIDS prevention campaigns has largely been toward an increase in knowledge and attitudes as opposed to personality variables. However, it is widely believed that persons with high interpersonal skills may be less likely to engage in sex risk behaviours. This study investigated interpersonal competence as a personality characteristic associated with sexual risk-taking among Jamaican adolescents. METHODS: A cross-sectional survey of 500 adolescents, ages 13-18 years (250 males and 250 females) from nine randomly selected secondary government schools within Kingston and St Andrew was used. The sample ensured maximum variation in age groups. The BarOn EQ-i:YV(S) was utilized to provide a measure of interpersonal competence and the Sex Risk Scale from the Adolescent Risk Inventory acted as a measure of sex risk behaviours. The Spearman's rho correlational statistic was used to investigate the hypothesis. RESULTS: Of the students surveyed, 58.6% reported that they were sexually active; 31.8% reported having multiple sexual partners and 28.2% reporting inconsistent condom use. A significant, inverse relationship was observed between interpersonal competence and sex risk behaviours (p < 0.05). CONCLUSION: This research provided evidence that adolescents with high interpersonal skills are less likely to participate in risky sexual behaviours. Therefore, interventions aimed at reducing risky adolescent sexual practices might benefit from the inclusion of strategies to build interpersonal skills.

Temperature distributions and gradients in laser-heated plasmas relevant to magnetized liner inertial fusion.

We present two-dimensional temperature measurements of magnetized and unmagnetized plasma experiments performed at Z relevant to the preheat stage in magnetized liner inertial fusion. The deuterium gas fill was doped with a trace amount of argon for spectroscopy purposes, and time-integrated spatially resolved spectra and narrow-band images were collected in both experiments. The spectrum and image data were included in two separate multiobjective analysis methods to extract the electron temperature spatial distribution T_{e}(r,z). The results indicate that the magnetic field increases T_{e}, the axial extent of the laser heating, and the magnitude of the radial temperature gradients. Comparisons with simulations reveal that the simulations overpredict the extent of the laser heating and underpredict the temperature. Temperature gradient scale lengths extracted from the measurements also permit an assessment of the importance of nonlocal heat transport.

In vivo assessment of mutations in OTC for dominant-negative effects following rAAV2/8-mediated gene delivery to the mouse liver.

Mutant proteins have the potential to exert dominant-negative effects that might limit the therapeutic efficacy of their wild-type counterparts after gene transfer. For ornithine transcarbamylase (OTC) deficiency, in vitro studies have suggested the presence of dominant-negative effects, however, supporting in vivo studies have not been conducted. In this study, we exploited the capacity of recombinant adeno-associated virus (rAAV) 2/8 vectors to deliver transgenes to the mouse liver with high efficiency to determine whether expression of selected OTC mutant proteins exert inhibitory effects on endogenous wild-type OTC enzymatic activity. Using site-directed mutagenesis we constructed three OTC mutants with a theoretical or reported in vitro capacity to exert dominant-negative effects, and delivered these to the liver using rAAV2/8. Each mutation had been earlier identified in patients with OTC deficiency. Treated mice showed no increase in urinary orotic acid levels or reduction in OTC activity despite supra-physiological expression of the mutant proteins, consistent with an absence of dominant-negative effects. These data have important implications for the development of gene therapy strategies for OTC deficiency and validate a model system in which potential dominant-negative effects of specific mutations in prospective patients can be examined empirically before gene therapy.

Congenital disorder of glycosylation type Ia: heterogeneity in the clinical presentation from multivisceral failure to hyperinsulinaemic hypoglycaemia as leading symptoms in three infants with phosphomannomutase deficiency.

We describe three patients with congenital disorder of glycosylation (CDG) type Ia, all of whom had persistent hyperinsulinaemic hypoglycaemia responding to diazoxide therapy as a common feature. The first patient, an infant girl, presented with recurrent vomiting, failure to thrive, liver impairment, hypothyroidism and a pericardial effusion. The second patient, also female, had a milder disease with single organ involvement, presenting as isolated hyperinsulinaemic hypoglycaemia, not associated with any cognitive impairment. The third patient, a boy presented with multi-organ manifestations including congenital hypothyroidism, persistent hyperinsulinaemic hypoglycaemia, coagulopathy, olivopontocerebellar hypoplasia and recurrent pancreatitis. All three patients had a type 1 serum transferrin isoform pattern, and were subsequently found to have low phosphomannomutase activity, confirming the diagnosis of CDG type Ia. Our findings emphasize that CDG should be considered as a differential diagnosis in patients with persistent hyperinsulinaemic hypoglycaemia and that it may even occasionally be the leading symptom in CDG Ia.

Glutaric aciduria type I: outcome following detection by newborn screening.

Glutaric aciduria type I (GA I), a cerebral organic acidaemia with the potential for severe neurological consequences, can now be detected by tandem mass spectrometry newborn screening. Early detection with implementation of careful management strategies appears to lessen the likelihood of neurological damage. We assessed the outcome in all 10 GA I patients detected in New South Wales during the last decade. Three patients were detected clinically and 7 by newborn screening. Diagnosis was confirmed by detection of significantly elevated urinary 3-hydroxybutyrate and glutarate in urine, isolated elevation of glutarylcarnitine in plasma, typical clinical and MRI findings in several, and mutation analysis or enzyme analysis on cultured skin fibroblasts in 4 cases. The birth frequency was 1:90,000. Following diagnosis, treatment was initiated in all children with oral carnitine (100 mg/kg per day) and a low-protein diet supplemented with a lysine-free, low-tryptophan amino acid formula. Disability was assessed in fields of motor, cognitive and speech development and scored according to Kyllerman. Clinically diagnosed patients were all symptomatic, with severity scores (out of 9) of 3, 5 and 9. Six of seven patients detected by newborn screening are asymptomatic, 4 being aged 2-6 years. One patient had a severe decompensation at 7 months, despite full management advice and treatment, and later died. Our data support previous findings that early diagnosis reduces neurological complications, but show that even with early diagnosis and careful management severe complications may ensue in some.

Assessment of the relationship between a written measure of empathy and an independently rated interview of Motivational Interviewing.

Motivational Interviewing (MI) is an evidence-based practice shown to be effective when working with people in treatment for substance use disorders. However, MI is a complex treatment modality optimized by training with feedback. Feedback, assessment and monitoring of treatment fidelity require measurement, which is typically done using audiotaped sessions. The gold standard for such measurement of MI skill has been an audiotaped interview, scored by a rater with a detailed structured instrument such as the Motivational Interviewing Treatment Integrity 2.0 (MITI 2.0) Coding System (Moyers, et al., 2005). The Helpful Responses Questionnaire (HRQ) (Miller, Hedrick, & Orlofsky, 1991) is a pen-and-paper test of empathy (a foundational MI skill) that does not require an audiotaped session. A randomized trial of three different regimens for training counselors in MI (live supervision using Teleconferencing, Tape-based supervision and Workshop only) (Smith et al., 2012) offered the opportunity to evaluate the performance of the HRQ as a measure of MI ability, compared to the several MITI 2.0 global scores and subscales. Participants were counselors (N=97) working at community-based substance use treatment programs, whose MI proficiency was measured at four time points: baseline (before an initial 2-day MI workshop), post-workshop, 8weeks post-workshop (i.e., post-supervision), and 20weeks post-workshop with both MITI 2.0 and HRQ. HRQ total scores correlated significantly with the Reflection to Question Ratio from the MITI 2.0 at post-workshop (r=0.33), week 8 (r=0.34), and week 20 (r=0.38), and with the Spirit (r=0.32) and Empathy (r=0.32) global scores at week 20. Correlations of HRQ with other MITI 2.0 subscales and time points after workshop were small and not significant. As predicted, HRQ scores differed between training conditions (X2(2)=7.88, p=0.02), with counselors assigned to live supervision achieving better HRQ scores than those in Workshop only. In summary, HRQ is a modestly accurate measure, mainly of the Reflection to Question Ratio, considered a core marker of MI skill. It is sensitive to training effects and may help identify counselors needing more intensive supervision. Given its ease of administration and scoring, HRQ may be a useful marker of MI skill during training efforts.

Low citrulline may not be diagnostic of ornithine transcarbamylase deficiency: a case report.

A newborn boy with family history of severe ornithine transcarbamylase (OTC) deficiency was investigated prospectively and managed aggressively at birth based on an existing protocol for at risk neonates. Undetectable citrulline levels at birth suggested that the infant was affected; however, normal plasma glutamine and urine orotic acid levels confused the diagnosis to some extent. Mutation testing confirmed that the patient did not have OTC deficiency. Thus the low plasma citrulline level did not validate our initial biochemical suspicion of OTC deficiency, and this highlights the importance of considering all available clinical, biochemical and molecular evidence in determining disease status.

Distinct right frontal lobe activation in language processing following left hemisphere injury.

Right hemisphere activation during functional imaging studies of language has frequently been reported following left hemisphere injury. Few studies have anatomically characterized the specific right hemisphere structures engaged. We used functional MRI (fMRI) with verbal fluency tasks in 12 right-handed patients with left temporal lobe epilepsy (LTLE) and 12 right-handed healthy controls to localize language-related activity in the right inferior frontal gyrus (RIFG). During the phonemic task, LTLE patients activated a significantly more posterior region of the right anterior insula/frontal operculum than healthy controls (P = 0.02). Activation of the left inferior frontal gyrus (LIFG) did not differ significantly between the two groups. This suggests that, following left hemisphere injury, language-related processing in the right hemisphere differs from that with a functionally normal left hemisphere. The localization of activation in the left and right inferior frontal gyri was determined with respect to the anatomical sub-regions pars opercularis (Pop), pars triangularis (Ptr) and pars orbitalis (Por). In the LIFG, both healthy controls (8 out of 12) and LTLE patients (9 out of 12) engaged primarily Pop during phonemic fluency. Activations in the RIFG, however, were located mostly in the anterior insula/frontal operculum in both healthy controls (8 out of 12) and LTLE patients (8 out of 12), albeit in distinct regions. Mapping the locations of peak voxels in relation to previously obtained cytoarchitectonic maps of Broca's area confirmed lack of homology between activation regions in the left and right IFG. Verbal fluency-related activation in the RIFG was not anatomically homologous to LIFG activation in either patients or controls. To test more directly whether RIFG activation shifts in a potentially adaptive manner after left hemisphere injury, fMRI studies were performed in a patient prior to and following anatomical left hemispherectomy for the treatment of Rasmussen's encephalitis. An increase in activation magnitude and posterior shift in location were found in the RIFG after hemispherectomy for both phonemic and semantic tasks. Together, these results suggest that left temporal lobe injury is associated with potentially adaptive changes in right inferior frontal lobe functions in processing related to expressive language.

Consumption of a high-fat breakfast on consecutive days alters preclinical biomarkers for atherosclerosis.

BACKGROUND/OBJECTIVES: Recent research has speculated that the risk of developing atherosclerosis is due to the accumulation of the effects of daily diet choices. The purpose of this study was to examine which of our previously identified preclinical disease risk biomarkers were further elevated when consuming a high-fat (644±50 kcal; 100% recommended dietary allowance for fat), high-calorie (1118±100 kcal; 70% daily caloric needs) breakfast on consecutive days. Young, normal weight females (N=7) participated in this study. SUBJECTS/METHODS: Blood samples were taken premeal and hourly for 5-h postprandial. Serum biomarkers (C-peptide, eotaxin, gastric inhibitory polypeptide, granulocyte colony-stimulating factor (G-CSF), granulocyte-monocyte colony-stimulating factor (GM-CSF), insulin, leptin, monocyte chemoattractant protein 1, pancreatic polypeptide (PPY) and tumor necrosis factor-α), monocyte concentration, and adhesion molecule expression (CD11a, CD18 and CD54) were measured. Area under the curve was calculated for each outcome variable as a function of day and data were analyzed for significance. RESULTS: We found significant (P<0.05) increases on Day 2 for: GM-CSF (+47%; P=0.041), G-CSF (+31%; P=0.012), PPY (+51%; P=0.049), total monocyte (+110%; P=0.043), pro-inflammatory (PI) monocyte (+60%; P=0.012), PI monocyte CD18 (+960%; P=0.003), PI monocyte CD11a (+230%; P=0.006), and PI monocyte CD54 (+208%; P=0.015). CONCLUSIONS: To our knowledge, the present study is the first to report changes in selected biomarkers and monocytes following eating a high-fat, high-calorie breakfast on consecutive days in humans. More research is needed to determine how transient the observed changes are and what the long-term implications for disease risk are.

Focal interstitial CC chemokine receptor 7 (CCR7) expression in idiopathic interstitial pneumonia.

BACKGROUND/AIMS: Idiopathic interstitial pneumonias (IIPs) are a diverse grouping of chronic pulmonary diseases characterised by varying degrees of pulmonary fibrosis. The triggers of the fibroproliferative process in IIP remain enigmatic but recent attention has been directed towards chemokine involvement in this process. METHODS: The expression of two chemokine receptors, CCR7 and CXCR4, and their respective ligands, CCL19, CCL21, and CXCL12, were examined in surgical lung biopsies (SLBs) from patients with IIP. Transcript and protein expression of these receptors and their ligands was compared with that detected in histologically normal margin SLBs. RESULTS: CCR7 and CXCR4 were detected by gene array and real time polymerase chain reaction analysis and CCR7, but not CXCR4, expression was significantly raised in usual interstitial pneumonia (UIP) relative to biopsies from patients diagnosed with non-specific interstitial pneumonia (NSIP) or respiratory bronchiolitis/interstitial lung disease (RBILD). CCR7 protein was expressed in interstitial areas of all upper and lower lobe UIP SLBs analysed. CCR7 expression was present in 50% of NSIP SLBs, and CCR7 was restricted to blood vessels and mononuclear cells in 75% of RBILD SLBs. Immune cell specific CXCR4 expression was seen in IIP and normal margin biopsies. CCR7 positive areas in UIP biopsies were concomitantly positive for CD45 (the leucocyte common antigen) but CCR7 positive areas in all IIP SLBs lacked the haemopoietic stem cell antigen CD34, collagen 1, and alpha smooth muscle actin. CONCLUSION: This molecular and immunohistochemical analysis showed that IIPs are associated with abnormal CCR7 transcript and protein expression.

Newborn screening may fail to identify intermediate forms of maple syrup urine disease.

The New South Wales state-wide newborn screening programme has offered comprehensive screening for inborn errors of metabolism, including MSUD, using electrospray tandem mass spectrometry since 1998. Over this period, a number of patients with classic MSUD have been identified with subsequent good neurological outcome. We describe two patients with an intermediate form of MSUD who presented later in childhood. Retrospective review of their newborn screening results demonstrates that the diagnosis could not have been made by current newborn screening. Their neurological outcome is much less satisfactory. Despite the usefulness of expanded newborn screening programmes in detecting severe neonatal presentations of inborn errors of metabolism, partial enzyme deficiencies may not be detected. Metabolic diseases still need to be considered in appropriate clinical situations later in life.

An index of biotic integrity based on the summer polyhaline zooplankton community of the Chesapeake Bay.

A zooplankton index of biotic integrity was developed for the polyhaline waters of the Chesapeake Bay using data from a long-term environmental assessment program in which both zooplankton and water quality were regularly monitored. Summer (July to September) sampling events were classified as either coming from impaired or reference (least-impaired) conditions based on water quality conditions. Seventeen zooplankton community metrics were evaluated under these criteria and nine were chosen for a composite index. These were the Simpson diversity index, and abundance of barnacle larvae, rotifers, cladocerans, copepods, total mesozooplankton, and predators. The composite index of biotic integrity correctly classified about 94% of the impaired samples and about 82% of the reference samples. Average classification efficiency was 88%. This index appears to be an effective measure of eutrophication for the summer polyhaline waters of the Chesapeake Bay ecosystem.

Lipids and oxidised lipids in human atheroma and normal aorta.

Lipids and oxidised lipids were analysed by GC and GC-MS in samples of human atheroma (necrotic gruel from the interior of advanced atherosclerotic plaques in the aorta) and human normal aorta (lesion-free intima plus inner media) from necropsy subjects. Cholest-5-en-3 beta,26-diol and cholest-5-en-3 beta,7 beta-diol were detected in all the atheroma samples examined but not in significant amounts in normal aorta. In atheroma, cholest-5-en-3 beta,26-diol was approximately proportional to cholesterol. Several isomeric hydroxy-octadecadienoic acids were detected in atheroma, and, in smaller amounts, in normal aorta. Many of the components of atheroma showed a high degree of cross-correlation on linear regression analysis, whilst cross-correlations were somewhat weaker for normal aorta. Atheroma showed a vast accumulation of lipid, especially cholesterol, in comparison to normal aorta. The atheroma samples contained a larger proportion of linoleate relative to oleate than the normal aorta. Levels of fatty acids relative to cholesterol were lower for atheroma than for normal aorta. The chemical composition of atheroma appeared unrelated to the age of the subject, whereas age-related increases in linoleate, oleate and cholesterol content were seen in the samples of normal aorta.

Lipids and oxidised lipids in human atherosclerotic lesions at different stages of development.

Lipids and oxidised lipids were analysed by GC and GC-MS in human necropsy samples of normal artery and individual atherosclerotic lesions, from aorta and common carotid artery, including fatty streaks, intermediate lesions and advanced lesions. Age-related increases were seen for linoleate, oleate and cholesterol in normal artery, but not in lesions. Each category of lesion was much richer than normal artery in all the lipids measured and in oxidised lipids (oxysterols and hydroxyoctadecadienoic acids), although a degree of overlap existed between the compositions of the various categories of lesion. 26-Hydroxycholesterol and 7 beta-hydroxycholesterol levels were extremely low or undetectable in normal artery, but significantly higher in each of the categories of lesions. The generally wide variation in lipid composition of individual lesions within each category, and the fact that a few individual lesions showed no detectable 26-hydroxycholesterol or 7 beta-hydroxycholesterol, suggested that the lipid oxidation in lesions and therefore perhaps the progression of lesions may be intermittent. Fatty streaks showed the highest concentration of 7 beta-hydroxycholesterol relative to cholesterol, and the lowest ratio of linoleate to oleate, suggesting that this type of lesion experiences the greatest concentration of free radical activity. Levels of the enzymatic product 26-hydroxycholesterol were approximately proportional to cholesterol in all the categories of lesions. 26-Hydroxycholesterol was significantly more abundant in advanced lesions than in intermediate lesions or fatty streaks. 26-Hydroxycholesterol levels were higher in macrophage-rich intermediate and advanced lesions than in their fibrous counterparts. This distinction between macrophage-rich and fibrous lesions was also true for most of the other lipid components, consistent with the involvement of macrophages in lipid accumulation, lipid oxidation and lesion development.