Results of the c-TRAK TN trial: a clinical trial utilising ctDNA mutation tracking to detect molecular residual disease and trigger intervention in patients with moderate- and high-risk early-stage triple-negative breast cancer

BACKGROUND

Post-treatment detection of circulating tumour DNA (ctDNA) in early-stage triple-negative breast cancer (TNBC) patients predicts high risk of relapse. c-TRAK TN assessed the utility of prospective ctDNA surveillance in TNBC and the activity of pembrolizumab in patients with ctDNA detected [ctDNA positive (ctDNA+)].

PATIENTS AND METHODS

c-TRAK TN, a multicentre phase II trial, with integrated prospective ctDNA surveillance by digital PCR, enrolled patients with early-stage TNBC and residual disease following neoadjuvant chemotherapy, or stage II/III with adjuvant chemotherapy. ctDNA surveillance comprised three-monthly blood sampling to 12 months (18 months if samples were missed due to coronavirus disease), and ctDNA+ patients were randomised 2 : 1 to intervention : observation. ctDNA results were blinded unless patients were allocated to intervention, when staging scans were done and those free of recurrence were offered pembrolizumab. A protocol amendment (16 September 2020) closed the observation group; all subsequent ctDNA+ patients were allocated to intervention. Co-primary endpoints were (i) ctDNA detection rate and (ii) sustained ctDNA clearance rate on pembrolizumab (NCT03145961).

RESULTS

Two hundred and eight patients registered between 30 January 2018 and 06 December 2019, 185 had tumour sequenced, 171 (92.4%) had trackable mutations, and 161 entered ctDNA surveillance. Rate of ctDNA detection by 12 months was 27.3% (44/161, 95% confidence interval 20.6% to 34.9%). Seven patients relapsed without prior ctDNA detection. Forty-five patients entered the therapeutic component (intervention n = 31; observation n = 14; one observation patient was re-allocated to intervention following protocol amendment). Of patients allocated to intervention, 72% (23/32) had metastases on staging at the time of ctDNA+, and 4 patients declined pembrolizumab. Of the five patients who commenced pembrolizumab, none achieved sustained ctDNA clearance.

CONCLUSIONS

c-TRAK TN is the first prospective study to assess whether ctDNA assays have clinical utility in guiding therapy in TNBC. Patients had a high rate of metastatic disease on ctDNA detection. Findings have implications for future trial design, emphasising the importance of commencing ctDNA testing early, with more sensitive and/or frequent ctDNA testing regimes.

The CannTeen study: verbal episodic memory, spatial working memory, and response inhibition in adolescent and adult cannabis users and age-matched controls

BACKGROUND

Preclinical and human studies suggest that adolescent cannabis use may be associated with worse cognitive outcomes than adult cannabis use. We investigated the associations between chronic cannabis use and cognitive function in adolescent and adult cannabis users and controls. We hypothesised user-status would be negatively associated with cognitive function and this relationship would be stronger in adolescents than adults.

METHODS

As part of the 'CannTeen' project, this cross-sectional study assessed cognitive performance in adolescent cannabis users (n = 76; 16-17-year-olds), adolescent controls (n = 63), adult cannabis users (n = 71; 26-29-year-olds) and adult controls (n = 64). Users used cannabis 1-7 days/week. Adolescent and adult cannabis users were matched on cannabis use frequency (4 days/week) and time since last use (2.5 days). Verbal episodic memory (VEM) was assessed using the prose recall task, spatial working memory (SWM) was assessed using the spatial n-back task, and response inhibition was assessed with the stop-signal task. Primary outcome variables were: delayed recall, 3-back discriminability, and stop signal reaction time, respectively.

RESULTS

Users had worse VEM than controls (F(1,268) = 7.423, p = 0.007). There were no significant differences between user-groups on SWM or response inhibition. Null differences were supported by Bayesian analyses. No significant interactions between age-group and user-group were found for VEM, SWM, or response inhibition.

CONCLUSIONS

Consistent with previous research, there was an association between chronic cannabis use and poorer VEM, but chronic cannabis use was not associated with SWM or response inhibition. We did not find evidence for heightened adolescent vulnerability to cannabis-related cognitive impairment.

Identification of functional candidate variants and genes for feed efficiency in Holstein and Jersey cattle breeds using RNA-sequencing

The identification of functional genetic variants and associated candidate genes linked to feed efficiency may help improve selection for feed efficiency in dairy cattle, providing economic and environmental benefits for the dairy industry. This study used RNA-sequencing data obtained from liver tissue from 9 Holstein cows [n = 5 low residual feed intake (RFI), n = 4 high RFI] and 10 Jersey cows (n = 5 low RFI, n = 5 high RFI), which were selected from a single population of 200 animals. Using RNA-sequencing, 3 analyses were performed to identify: (1) variants within low or high RFI Holstein cattle; (2) variants within low or high RFI Jersey cattle; and (3) variants within low or high RFI groups, which are common across both Holstein and Jersey cattle breeds. From each analysis, all variants were filtered for moderate, modifier, or high functional effect, and co-localized quantitative trait loci (QTL) classes, enriched biological processes, and co-localized genes related to these variants, were identified. The overlapping of the resulting genes co-localized with functional SNP from each analysis in both breeds for low or high RFI groups were compared. For the first two analyses, the total number of candidate genes associated with moderate, modifier, or high functional effect variants fixed within low or high RFI groups were 2,810 and 3,390 for Holstein and Jersey breeds, respectively. The major QTL classes co-localized with these variants included milk and reproduction QTL for the Holstein breed, and milk, production, and reproduction QTL for the Jersey breed. For the third analysis, the common variants across both Holstein and Jersey breeds, uniquely fixed within low or high RFI groups were identified, revealing a total of 86,209 and 111,126 functional variants in low and high RFI groups, respectively. Across all 3 analyses for low and high RFI cattle, 12 and 31 co-localized genes were overlapping, respectively. Among the overlapping genes across breeds, 9 were commonly detected in both the low and high RFI groups (INSRR, CSK, DYNC1H1, GAB1, KAT2B, RXRA, SHC1, TRRAP, PIK3CB), which are known to play a key role in the regulation of biological processes that have high metabolic demand and are related to cell growth and regeneration, metabolism, and immune function. The genes identified and their associated functional variants may serve as candidate genetic markers and can be implemented into breeding programs to help improve the selection for feed efficiency in dairy cattle.

Development and comparison of RNA-sequencing pipelines for more accurate SNP identification: practical example of functional SNP detection associated with feed efficiency in Nellore beef cattle

Background

Optimization of an RNA-Sequencing (RNA-Seq) pipeline is critical to maximize power and accuracy to identify genetic variants, including SNPs, which may serve as genetic markers to select for feed efficiency, leading to economic benefits for beef production. This study used RNA-Seq data (GEO Accession ID: PRJEB7696 and PRJEB15314) from muscle and liver tissue, respectively, from 12 Nellore beef steers selected from 585 steers with residual feed intake measures (RFI; n = 6 low-RFI, n = 6 high-RFI). Three RNA-Seq pipelines were compared including multi-sample calling from i) non-merged samples; ii) merged samples by RFI group, iii) merged samples by RFI and tissue group. The RNA-Seq reads were aligned against the UMD3.1 bovine reference genome (release 94) assembly using STAR aligner. Variants were called using BCFtools and variant effect prediction (VeP) and functional annotation (ToppGene) analyses were performed.

Results

On average, total reads detected for Approach i) non-merged samples for liver and muscle, were 18,362,086.3 and 35,645,898.7, respectively. For Approach ii), merging samples by RFI group, total reads detected for each merged group was 162,030,705, and for Approach iii), merging samples by RFI group and tissues, was 324,061,410, revealing the highest read depth for Approach iii). Additionally, Approach iii) merging samples by RFI group and tissues, revealed the highest read depth per variant coverage (572.59 ± 3993.11) and encompassed the majority of localized positional genes detected by each approach. This suggests Approach iii) had optimized detection power, read depth, and accuracy of SNP calling, therefore increasing confidence of variant detection and reducing false positive detection. Approach iii) was then used to detect unique SNPs fixed within low- (12,145) and high-RFI (14,663) groups. Functional annotation of SNPs revealed positional candidate genes, for each RFI group (2886 for low-RFI, 3075 for high-RFI), which were significantly (P < 0.05) associated with immune and metabolic pathways.

Conclusion

The most optimized RNA-Seq pipeline allowed for more accurate identification of SNPs, associated positional candidate genes, and significantly associated metabolic pathways in muscle and liver tissues, providing insight on the underlying genetic architecture of feed efficiency in beef cattle.

Perioperative intravenous contrast administration and the incidence of acute kidney injury after major gastrointestinal surgery: prospective, multicentre cohort study

BACKGROUND

This study aimed to determine the impact of preoperative exposure to intravenous contrast for CT and the risk of developing postoperative acute kidney injury (AKI) in patients undergoing major gastrointestinal surgery.

METHODS

This prospective, multicentre cohort study included adults undergoing gastrointestinal resection, stoma reversal or liver resection. Both elective and emergency procedures were included. Preoperative exposure to intravenous contrast was defined as exposure to contrast administered for the purposes of CT up to 7 days before surgery. The primary endpoint was the rate of AKI within 7 days. Propensity score-matched models were adjusted for patient, disease and operative variables. In a sensitivity analysis, a propensity score-matched model explored the association between preoperative exposure to contrast and AKI in the first 48 h after surgery.

RESULTS

A total of 5378 patients were included across 173 centres. Overall, 1249 patients (23·2 per cent) received intravenous contrast. The overall rate of AKI within 7 days of surgery was 13·4 per cent (718 of 5378). In the propensity score-matched model, preoperative exposure to contrast was not associated with AKI within 7 days (odds ratio (OR) 0·95, 95 per cent c.i. 0·73 to 1·21; P = 0·669). The sensitivity analysis showed no association between preoperative contrast administration and AKI within 48 h after operation (OR 1·09, 0·84 to 1·41; P = 0·498).

CONCLUSION

There was no association between preoperative intravenous contrast administered for CT up to 7 days before surgery and postoperative AKI. Risk of contrast-induced nephropathy should not be used as a reason to avoid contrast-enhanced CT.

P6244Cytomegalovirus (CMV) burden may be used to enhance algorithms to predict future cardiovascular health in renal transplant recipients and healthy controls

Background

Cytomegalovirus (CMV) has been implicated in accelerated cardiovascular changes and may warrant inclusion in predictive algorithms. This is addressed here in healthy older adults and in renal transplant recipients (RTR) stable on therapy as they retain a high burden of CMV.

Methods

RTR (n=45) stable >2 years after transplantation and 58 age-matched healthy adults were recruited in 2014 and returned in 2017. Venous blood samples and saliva were collected, frozen and stored. Plasma proteins linked with inflammation [soluble interferon a receptor 2 (sIFNaR2), sTNFR1, sCD14, C-reactive protein (CRP)], vasculopathy [p-selectin, intercellular adhesion molecule 1 (ICAM-1), vascular cell adhesion molecule 1 (VCAM-1)], and metrics of CMV burden [antibodies reactive with CMV lysate, gB or IE-1 (by ELISA), CMV DNA in saliva (by PCR) and T-cell IFNg responses to CMV antigens (by ELISpot)] were assessed in 2014. In 2017, vascular endpoint measurements included brachial artery flow mediated dilatation (FMD), pulse wave analysis [augmented index corrected to heart rate of 75 beats per minute (Aix@75)] and pulse wave velocity (PWV).

Results

In 2017, RTR had lower FMD % (p<0.001), higher PWV (<0.001) and slightly higher Aix@75 values (p=0.14) compared with healthy adults, indicating inferior vascular health. In a multivariable regression model (adjusted R2=0.42) predicting 2017 FMD in RTR (adjusted for age, sex, BMI, eGFR, sCD14, CMV gB Ab and saliva CMV DNA), each 1AU/mL increase of CMV gB Ab (p=0.03) predicted a 5% increase in FMD – associating with better vascular outcomes, but detectable saliva CMV DNA (p=0.02) associated with a 3% increase in FMD. In healthy adults, however, while predicting 2017 FMD (adjusting for p-selectin, ICAM-1, age, sex, BMI, eGFR; adjusted R2=0.22), a 1 ng/mL increase in p-selectin (p=0.03) predicted a 0.04% increase in FMD, and 1 ng/mL increase in ICAM-1 (p=0.03) associated with 0.03% lower FMD. From the pulse wave analyses of RTR, every 1ng/mL increase of sIFNaR2 (p=0.06) marginally predicted 1.4 unit decrease in Aix@75 (adjusted for CMV IE-1 Ab, sIFNaR2, age, sex, BMI and eGFR; adjusted R2=0.37). However in healthy adults, each 1ng/mL increase of sIFNaR2 levels (p=0.04) associated with 3.5 units worsening of Aix@75 (p=0.04) (adjusted R2 = 0.40). Each 1 AU/mL increase in CMV IE-1 Ab levels associated with 0.08 units decrease in PWV (p=0.02) (adjusting for CMV IE-1 Ab, sCD14, age, sex, BMI and eGFR adjusted R2=0.55).

Conclusions

Overall measures of a high burden of CMV, predicted a low FMD marking poor peripheral vascular health in RTR several years after assessment, with more potency than was achieved with plasma markers of systemic and vascular inflammation, which was observed in healthy controls. CMV antibodies can predict future measures of arterial stiffness such as Aix@75 and PWV in healthy controls, but need further investigation in larger cohorts.

Abstract PD1-07: Withdrawn

This abstract was withdrawn by the authors.

Citation Format: Howell SJ, Waters S, Twelves C, Joffe J, Moon S, Bale C, Venkitaraman R, Bezecny P, Casbard A, Wilhelm-Benartzi C, Carucci M, Butler R, Alchami F, Jones R. Withdrawn [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr PD1-07.

Abstract PD3-09: Pertuzumab and trastuzumab with or without metronomic chemotherapy for older patients with HER2- positive metastatic breast cancer: Results from the EORTC 75111- 10114 ETF/BCG randomized phase II study

Introduction: Pertuzumab (P) is approved as first line therapy for HER2-positive (HER2+) metastatic breast cancer (MBC) combined with trastuzumab (T) and docetaxel. However older patients are at higher risk of chemotherapy-induced toxicity raising high interest in a less toxic backbone such as metronomic chemotherapy and in chemo-free dual HER2 blockade (TP). Patients and Methods: This phase II selection study randomized (1:1) patients with HER2+ MBC, aged 70+ or frail 60+, to first line chemotherapy with metronomic oral cyclophosphamide 50 mg/day + TP (TPM) or TP alone. Prior endocrine therapy and up to 1 line of anti-HER2 therapy (without chemotherapy) for MBC were allowed.T-DM1 was offered in case of progression. Randomization was stratified according to hormonal receptors, previous anti-HER2 treatment and geriatric assessment. Primary endpoint was progression-free survival (PFS) rate at 6 months seeking a difference of ≥ 10% between the two arms. Results: Between July 2013 and May 2016, 39 and 41 patients were randomized to TP and TPM arm respectively: median age 76.7 years, hormone receptor positivity 69%, prior adjuvant T 11%, prior metastatic T (with endocrine therapy) 3%, visceral involvement 93.7%, potential frailty profile according to geriatric screening G8 (≤14) 71% and/or to short physical performance battery (&lt;10) 81%, Charlson comorbidity score &gt; 0 in 40%. With 20.7 months of median follow-up, 6-month and median PFS were 46.2% (95% CI 30.2-60.7) and 5.6 months (95% CI 3.6-16.8) versus 73.4% (95% CI 56.6-84.6) and 12.7 months (95% CI 6.7-24.8) for TP and TPM, respectively. Four patients in TPM and 2 in TP developed brain metastases only as progression event. OS and breast cancer specific survival were comparable between the two arms; 9/29 deaths were not breast cancer-related. Response rate was 44% in TP arm and 53% in TPM arm. In 29 patients who received T-DM1 second line, 6-month PFS, median PFS and response rate were 49.5% (95% CI 29.2-66.9), 5 months (95% CI 2.5-12.5) and 13.5%. In patients who discontinued TP(M), 37, 9 and 14 stopped because of progression, toxicity or other reasons, respectively. During TPM treatment, 1 patient died of heart failure and 1 developed grade 3 heart failure; 1 patient in each arm developed a ≥ 10% asymptomatic left ventricular ejection fraction decrease below 50%. Diarrhea any grade and grade ≥ 3 were observed in 56% and 8% versus 71% and 12% patients in TP and TPM arms, respectively. No grade 3 or febrile neutropenia was reported. There was no relevant difference in functional evolution between both groups. In the whole population, several geriatric items were of prognostic value by multivariate analysis: e.g. for OS, G8 &gt;14 vs ≤ 14 HR=0.12 (95% CI 0.03-0.55, p 0.006). In 29 patients receiving T-DM1, grade 3 toxicity was rare: fatigue (2 patients), thrombocytopenia and epistaxis (1 patient). Conclusions: Metronomic chemotherapy-based dual blockade (TPM) seems to be superior to dual blockade alone (TP) in an elderly/frail HER2+ MBC population, with an attractive safety profile. TPM, followed by T-DM1 after progression, may delay or supersede taxane chemotherapy in this population.

Citation Format: Wildiers H, Tryfonidis K, dal Lago L, Vuylsteke P, Curigliano G, Waters S, Brouwers B, Aalders K, Meulemans B, Litiere S, Touati N, Cardoso F, Brain E. Pertuzumab and trastuzumab with or without metronomic chemotherapy for older patients with HER2- positive metastatic breast cancer: Results from the EORTC 75111- 10114 ETF/BCG randomized phase II study [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr PD3-09.

Fertility and genomics: comparison of gene expression in contrasting reproductive tissues of female cattle

To compare gene expression among bovine tissues, large bovine RNA-seq datasets were used, comprising 280 samples from 10 different bovine tissues (uterine endometrium, granulosa cells, theca cells, cervix, embryos, leucocytes, liver, hypothalamus, pituitary, muscle) and generating 260 Gbases of data. Twin approaches were used: an information–theoretic analysis of the existing annotated transcriptome to identify the most tissue-specific genes and a de-novo transcriptome annotation to evaluate general features of the transcription landscape. Expression was detected for 97% of the Ensembl transcriptome with at least one read in one sample and between 28% and 66% at a level of 10 tags per million (TPM) or greater in individual tissues. Over 95% of genes exhibited some level of tissue-specific gene expression. This was mostly due to different levels of expression in different tissues rather than exclusive expression in a single tissue. Less than 1% of annotated genes exhibited a highly restricted tissue-specific expression profile and approximately 2% exhibited classic housekeeping profiles. In conclusion, it is the combined effects of the variable expression of large numbers of genes (73%–93% of the genome) and the specific expression of a small number of genes (<1% of the transcriptome) that contribute to determining the outcome of the function of individual tissues.

Coagulation status in dogs with naturally occurring Angiostrongylus vasorum infection

OBJECTIVES

Angiostrongylus vasorum infection is associated with bleeding tendencies in approximately one-third of clinical cases. The cause of the coagulopathy is poorly understood but may be related to disseminated intravascular coagulation. Thromboelastography is a global evaluation of coagulation and has not been described in a cohort of dogs with this disease.

MATERIALS AND METHODS

Thromboelastography in association with other measures of coagulation including prothrombin and activated partial thromboplastin times, antithrombin percentage activity and D-dimer and von Willebrand factor concentrations was evaluated in a group of 30 dogs with A. varosum infection.

RESULTS

A total of 18 dogs had signs of bleeding on physical examination. Thromboelastography was consistent with hypocoagulation in 17 of these dogs. There was no association between any of the other measures and hypocoagulation on thromboelastography. Abnormal coagulation times were not significantly associated with bleeding. Only fibrinogen concentration was significantly lower in dogs that were bleeding compared with those that were not (P = 0 · 026). D-dimer concentrations were increased in 22/25 cases in the study; however, other coagulation parameters were more variable.

CLINICAL SIGNIFICANCE

Although the changes identified in this study were not consistent, there is activation of coagulation within this population, possibly consistent with an intravascular disseminated coagulopathy.

Parent emotion representations and the socialization of emotion regulation in the family

There is considerable knowledge of parental socialization processes that directly and indirectly influence the development of children’s emotion self-regulation, but little understanding of the specific beliefs and values that underlie parents’ socialization approaches. This study examined multiple aspects of parents’ self-reported emotion representations and their associations with parents’ strategies for managing children’s negative emotions and children’s emotion self-regulatory behaviors. The sample consisted of 73 mothers of 4–5-year-old children; the sample was ethnically diverse. Two aspects of parents’ beliefs about emotion – the importance of attention to/acceptance of emotional reactions, and the value of emotion self-regulation – were associated with both socialization strategies and children’s self-regulation. Furthermore, in mediational models, the association of parental representations with children’s emotion regulation was mediated by constructive socialization strategies. These findings are among the first to highlight the specific kinds of emotion representations that are associated with parents’ emotion socialization, and their importance to family processes shaping children’s emotional development.

Combined pubic rami and sacral osteoporotic fractures: a prospective study

Background

Pelvic osteoporotic fractures (POFs) are often associated with considerable morbidity and mortality mainly as a result of infections and cardiovascular events. Patients usually need prolonged institutionalization, rehabilitation, and follow-up, with a high rate of dependency and cost. The most common sites of POFs include the pubic rami, sacrum, ilium, and acetabulum. Combined pubic rami (PROFs) and sacral osteoporotic fractures (SOFs) have been reported, mostly in retrospective studies, describing the mechanism of injury and incidence. The aim of this study was to evaluate the association between PROFs and SOFs and to assess the effect of combined PROFs and SOFs on patients’ mobility, discharge destination, and length of stay.

Materials and methods

We prospectively studied 67 patients with low-impact PROFs and/or SOFs. There were 54 (80.4%) female and 13 (19.6%) male patients, and the average age was 87.5 (range 65–96) years. All patients were assessed by the fracture liaison service. Patients had magnetic resonance imaging or bone scan when there was history of low back pain following the injury or lumbosacral tenderness on clinical examination.

Results

The mean length of stay for all patients was 45 (±35) days. Mortality rate was 10.4%. A significant relationship was found between low back pain and a positive finding of sacral fracture. Patients with combined PROFs and SOFs showed significantly longer length of stay than those with isolated PROFs.

Conclusions

The presence of low back pain and tenderness in patients who had low-impact pelvic injuries was highly suggestive of the presence of an associated SOF. There was a high association between sacral and PROFs. The length of stay of patients with PROFs associated with sacral osteoporotic fractures was significantly longer than that of patients with PROFs only. Therefore, we recommend considering the high association between SOFs and PROFs in planning the management and rehabilitation of patients with POFs.

The EuroPhysiome, STEP and a roadmap for the virtual physiological human

Biomedical science and its allied disciplines are entering a new era in which computational methods and technologies are poised to play a prevalent role in supporting collaborative investigation of the human body. Within Europe, this has its focus in the virtual physiological human (VPH), which is an evolving entity that has emerged from the EuroPhysiome initiative and the strategy for the EuroPhysiome (STEP) consortium. The VPH is intended to be a solution to common infrastructure needs for physiome projects across the globe, providing a unifying architecture that facilitates integration and prediction, ultimately creating a framework capable of describing Homo sapiens in silico. The routine reliance of the biomedical industry, biomedical research and clinical practice on information technology (IT) highlights the importance of a tailor-made and robust IT infrastructure, but numerous challenges need to be addressed if the VPH is to become a mature technological reality. Appropriate investment will reap considerable rewards, since it is anticipated that the VPH will influence all sectors of society, with implications predominantly for improved healthcare, improved competitiveness in industry and greater understanding of (patho)physiological processes. This paper considers issues pertinent to the development of the VPH, highlighted by the work of the STEP consortium.

MCP-1 and murine prion disease: separation of early behavioural dysfunction from overt clinical disease

Prion diseases are chronic, fatal neurodegenerative conditions of the CNS. We have investigated the role of monocyte chemoattractant protein-1 (MCP-1) in the ME7 model of murine prion disease. MCP-1 expression increased in the CNS throughout disease progression and was positively correlated with microglial activation. We subsequently compared the inflammatory response, pathology and behavioural changes in wild-type (wt) mice and MCP-1 knockout mice (MCP-1-/-) inoculated with ME7. Late-stage clinical signs were delayed by 4 weeks in MCP-1-/- mice, and survival time increased by 2-3 weeks. By contrast, early changes in affective behaviours and locomotor activity were not delayed in onset. There was also no difference in microglial activation or neuronal death in the hippocampus and thalamus of wt mice and MCP-1-/- mice. These results highlight an important dissociation between prolonged survival, early behavioural dysfunction and hippocampal/thalamic pathology when considering therapeutic intervention for human prion diseases and other chronic neurodegenerative conditions.

Central nervous system injury triggers hepatic CC and CXC chemokine expression that is associated with leukocyte mobilization and recruitment to both the central nervous system and the liver

The administration of interleukin-1beta to the brain induces hepatic CXC chemokine synthesis, which increases neutrophil levels in the blood, liver, and brain. We now show that such hepatic response is not restricted to the CXC chemokines. CCL-2, a CC chemokine, was released by the liver in response to a tumor necrosis factor (TNF)-alpha challenge to the brain and boosted monocyte levels. Furthermore, a clinically relevant compression injury to the spinal cord triggered hepatic chemokine expression of both types. After a spinal cord injury, elevated CCL-2 and CXCL-1 mRNA and protein were observed in the liver by TaqMan reverse transcriptase-polymerase chain reaction and enzyme-linked immunosorbent assay as early as 2 to 4 hours. Simultaneously, we observed elevated levels of these chemokines and circulating leukocyte populations in the blood. Leukocytes were recruited to the liver at this early stage, whereas at the site of challenge in the central nervous system, few were observed until 24 hours. Artificial elevation of blood CCL-2 triggered dose-dependent monocyte mobilization in the blood and enhanced monocyte recruitment to the brain after TNF-alpha challenge. Attenuation of hepatic CCL-2 production with corticosteroids resulted in reduced monocyte levels after the TNF-alpha challenge. Thus, combined production of CC and CXC hepatic chemokines appears to amplify the central nervous system response to injury.

MRI reveals that early changes in cerebral blood volume precede blood-brain barrier breakdown and overt pathology in MS-like lesions in rat brain

Magnetic resonance imaging (MRI) is an established clinical tool for diagnosing multiple sclerosis (MS), the archetypal central nervous system neuroinflammatory disease. In this study, we have used a model of delayed-type hypersensitivity in the rat brain, which bears many of the hallmarks of an MS lesion, to investigate the development of MRI-detectable changes before the appearance of conventional indices of lesion development. In addition, we have correlated the MRI-detectable changes with the developing histopathology. Significant increases in regional cerebral blood volume (rCBV) preceded overt changes in blood-brain barrier (BBB) permeability, T2 relaxation and the diffusion properties of tissue water. Thus, changes in rCBV might be a more sensitive indicator of lesion onset than the conventional indices used clinically in MS patients, such as contrast enhancement. In addition, we show that BBB breakdown, and consequent edema formation, are more closely correlated with astrogliosis than any other histopathologic changes, while regions of T1 and T2 hypointensity appear to reflect hypercellularity.

CINC-1 is an acute-phase protein induced by focal brain injury causing leukocyte mobilization and liver injury

Following injury or infection, the liver releases acute-phase proteins (APP). After a severe focal injury, this systemic response can be excessive and may lead to multiorgan dysfunction (MODS). CINC-1 is a neutrophil chemoattractant, and we have now established that it also functions as an early APP after injury to the brain or to peripheral tissues. After induction of a focal inflammatory lesion in the brain, there is rapid hepatic and serum CINC-1 induction, which is associated with increases in neutrophil numbers within the liver and within the circulation. CINC-1-mediated recruitment of neutrophils to organs distant from the primary injury site may contribute to MODS. Indeed, we found that enzyme markers of liver tissue injury are increased in the serum following generation of a focal inflammatory lesion in the brain. Neutralization of CINC-1 in the periphery reversed brain-injury-induced neutrophil mobilization and inhibited recruitment of neutrophils to the brain and to the liver. Thus, a significant component of the hepatic acute-phase response is the release of chemokines by the liver, which act to amplify the inflammatory response and modulate the subsequent leukocytosis and secondary tissue damage. Hepatic CINC-1 synthesis following injury presents a novel focus for treatment of inflammation.

Synaptic changes characterize early behavioural signs in the ME7 model of murine prion disease

Prion diseases are fatal, chronic neurodegenerative diseases of mammals, characterized by amyloid deposition, astrogliosis, microglial activation, tissue vacuolation and neuronal loss. In the ME7 model of prion disease in the C57BL/6 J mouse, we have shown previously that these animals display behavioural changes that indicate the onset of neuronal dysfunction. The current study examines the neuropathological correlates of these early behavioural changes. After injection of ME7-infected homogenate into the dorsal hippocampus, we found statistically significant impairment of burrowing, nesting and glucose consumption, and increased open field activity at 13 weeks. At this time, microglia activation and PrPSc deposition was visible selectively throughout the limbic system, including the hippocampus, entorhinal cortex, medial and lateral septum, mamillary bodies, dorsal thalamus and, to a lesser degree, in regions of the brainstem. No increase in apoptosis or neuronal cell loss was detectable at this time, while in animals at 19 weeks postinjection there was 40% neuronal loss from CA1. There was a statistically significant reduction in synaptophysin staining in the stratum radiatum of the CA1 at 13 weeks indicating loss of presynaptic terminals. Damage to the dorsal hippocampus is known to disrupt burrowing and nesting behaviour. We have demonstrated a neuropathological correlate of an early behavioural deficit in prion disease and suggest that this should allow insights into the first steps of the neuropathogenesis of prion diseases.

A behavioural pattern analysis of hypoglutamatergic mice--effects of four different antipsychotic agents

In a hypoglutamatergic rodent model, we have observed certain behaviours that might have relevance for the cognitive impairments seen in autism and schizophrenia. Thus, hypoglutamatergic mice show defective habituation, impaired attention, a meagre behavioural repertoire and a general behavioural primitivization. The aim of the present study was to characterise and quantify changes in movement pattern in mice rendered hypoglutamatergic by means of MK-801 treatment, using an automated video tracking system. Further, the effects of four different antipsychotic drugs, the classical neuroleptic haloperidol, the atypical antipsychotic clozapine, the DA D2/5-HT2A antagonist risperidone and the selective 5-HT2A-receptor antagonist M100907, were compared with respect to effects on NMDA antagonist-induced movement pattern alterations. We found that each receptor antagonist had a unique effect on the MK-801-induced behavioural primitivization. Haloperidol was unable to affect the monotonous behaviour induced by MK-801, while risperidone, clozapine and M100907 produced movement patterns of high intricacy.

Standardisation of 11C

The increasing use of positron emission tomography for medical imaging and the availability of short-lived positron emitters has raised concerns about the accuracy of calibration of secondary standard measurement systems and the viability of using a single long-lived positron emitter as a reference calibration source for all positron emitters. Potential problems arise because the 511 keV quanta arising from positron annihilation are not generally produced at the same point as the original disintegration. In addition, the secondary standard may also be responsive to the associated bremsstrahlung radiation. The magnitude of both effects depends on the positron end-point energy. In order to resolve these problems, it is necessary to produce absolute standards of these positron-emitting radionuclides and the work presented here details the results of such work with 11C.

Production of free radicals measured by spin trapping during operations for stenosis of the carotid artery

OBJECTIVES

To analyse production of free radicals during operations for stenosis of the internal carotid artery.

SETTING

University hospital, Sweden.

SUBJECTS

10 patients operated on for carotid artery stenosis.

INTERVENTIONS

Blood samples were repeatedly drawn from the sigmoid sinus through a catheter in the internal jugular vein on the same side, before, during, and after clamping of the internal carotid artery. OXANOH was added to the blood samples in vitro and the radical production calculated from the amount oxidised to OXANO as electron spin resonance.

MAIN OUTCOME MEASURES

The relation between radical production and certain clinical variables investigated by partial least squares regression analysis.

RESULTS

There were several significant relations. High systolic blood pressure and advanced age were associated with low, and severe degree of stenosis with increased, free radical production. Certain anaesthetic drugs as well as blood variables also influenced the production of radicals.

CONCLUSIONS

The technique used seems to offer the possibility to find and study methods to reduce free radical production during this kind of operation.

Translocation (2;8)(p12;q24) associated with a cryptic t(12;21)(p13;q22) TEL/AML1 gene rearrangement in a child with acute lymphoblastic leukemia

We report a case of childhood acute lymphoblastic leukemia with the simultaneous occurrence of a t(2;8)(p12;q24) typically associated with mature B cell or Burkitt leukemia, and a t(12;21)(p13;q22) exclusively associated with pre-B cell ALL. The lymphoblasts were characterized as L2 morphology by the French-American-British classification. However, there were atypical morphologic findings for L2 ALL, including vacuolization in some cells. The lymphoblasts were periodic acid-Schiff positive and myeloperoxidase negative. Immunophenotypic analysis revealed that the majority of lymphoblasts were TdT+, CD10+, CD19+, CD20-, and cytoplasmic mu+. These features were consistent with an immature pre-B cell leukemia phenotype with some characteristics of a mature B-cell leukemia. A t(2;8)(p12;q24)(p12;q24), characteristic of mature B-cell leukemia or Burkitt type leukemia, was detected by conventional cytogenetics with no other cytogenetic abnormalities. However, diagnostic peripheral blood and bone marrow specimens demonstrated simultaneous occurrence of a cryptic t(12;21)(p13;q22) by both FISH and RT-PCR. The simultaneous occurrence of these translocations in a pediatric patient have implications for the pathogenesis of leukemias with t(2;8)(p12;q24) as well as t(12;21)(p12;q22). Analysis of additional cases of leukemia with translocations involving the MYC locus on 8q24 will be required to determine the frequency of association with the cryptic t(12;21)(p13;22), and the prognostic significance of the simultaneous occurrence of the translocations.

Network interactions in schizophrenia - therapeutic implications

Research into the role of neurotransmitters and neural networks in the pathogenesis of schizophrenia has been remarkably successful in recent years. The hypothesis postulating a dopamine dysfunction, which has for a long time been supported only by indirect evidence, has received direct support by means of sophisticated imaging techniques. Interactions between dopamine and several other neurotransmitters in complex neural networks have been revealed, largely thanks to the advent of an array of new pharmacological probes. Two major pharmacological models of schizophrenia, based on hyperdopaminergia and hypoglutamatergia, respectively, are ready for clinical testing. In addition, the hypothesis of network stabilization as a major therapeutic strategy in psychiatry and neurology has now reached the 'proof-of-concept' level. From a therapeutic perspective, several ongoing and forthcoming clinical trials, using drugs acting on dopaminergic, serotonergic and glutamatergic receptors, give rise to optimism.

The 5-HT2A receptor antagonist M100907 is more effective in counteracting NMDA antagonist- than dopamine agonist-induced hyperactivity in mice

The purpose of the present study was to compare the effectiveness of the selective 5-HT2A antagonist M100907 in different psychosis models. The classical neuroleptic haloperidol was used as reference compound. Two hyperdopaminergia and two hypoglutamatergia mouse models were used. Hyperdopaminergia was produced by the DA releaser d-amphetamine or the DA uptake inhibitor GBR 12909. Hypoglutamatergia was produced by the un-competitive NMDA receptor antagonist MK-801 or the competitive NMDA receptor antagonist D-CPPene. M100907 was found to counteract the locomotor stimulant effects of the NMDA receptor antagonists MK-801 and D-CPPene, but spontaneous locomotion, d-amphetamine- and GBR-12909-induced hyperactivity were not significantly affected. Haloperidol, on the other hand, antagonized both NMDA antagonist- and DA agonist-induced hyperactivity, as well as spontaneous locomotion in the highest dose used. Based on the present and previous results we draw the conclusion that 5-HT2A receptor antagonists are particularly effective against behavioural anomalies resulting from hypoglutamatergia of various origins. The clinical implications of our results and conclusions would be that a 5-HT2A receptor antagonist, due to i a the low side effect liability, could be the preferable treatment strategy in various disorders associated with hypoglutamatergia; such conditions might include schizophrenia, childhood autism and dementia disorders.

MK-801-induced hyperlocomotion: differential effects of M100907, SDZ PSD 958 and raclopride

The influence of three selective monoamine receptor antagonists on spontaneous locomotion and on the hyperlocomotion induced by the un-competitive N-methyl-D-aspartate (NMDA) receptor antagonist [+]-5-methyl-10,11-dihydro-5H-dibenzo-[a,d]-cyclohepten-5,10-imine hydrogen maleate (MK-801; dizocilpine) was investigated. The selective and potent 5-hydroxytryptamine (5-HT)2A receptor antagonist R(+)-alpha(2,3-dimethoxyphenyl)-1-[2(4-fluorophenyl)ethyl)]-4-piperidine -methanol (MDL100,907; M100907) displayed a clear-cut selectivity for reduction of MK-801-induced as compared to spontaneous locomotion, in that the former was dose-dependently (0.001, 0.01, 0.1 mg/kg i.p.) blocked and even totally abolished by the highest dose, while the latter was only modestly affected. Even at high doses of M100907 (up to 9 mg/kg i.p.), spontaneous locomotion was not reduced below 40% of control. The selective dopamine D1 receptor antagonist (-)-[4aR, 10 aR]-1,2,3,4,4a,5,10,10a-octahydro-4-(4-chloro-2-methyl-phenyl)-1-methyl- benzo[g]quinoxaline-6-ol (SDZ PSD 958; 0.017, 0.15, 1.35 mg/kg i.p.) decreased both spontaneous and MK-801-induced locomotion with a slight preference for the latter; spontaneous locomotion was dose-dependently diminished to approx. 10% of controls (at 8 mg/kg i.p.). The dopamine D2 receptor antagonist raclopride ([(-)-(S)-3,5-dichloro-N-((1-ethyl-2-pyrrolidinyl) methyl)-6-methoxy-salicylamide tartrate]; 0.11, 0.33, 1.0 mg/kg i.p.) reduced both MK-801-induced and spontaneous locomotion to a similar extent. An orthogonal matrix experimental design, and multiple regression, were used to evaluate the effects of several combinations of different doses of the 5-HT2A receptor antagonist and the dopamine D1 receptor antagonist. No synergistic actions on reduction of spontaneous or MK-801-induced locomotion were detected between M100907 and SDZ PSD 958. If the hyperlocomotion elicited by acutely administered MK-801 is a valid model of at least some aspects of schizophrenia, these results indicate that the 5-HT2A receptor antagonist M100907 will have efficacy in treating this condition. The lack of effect on spontaneous locomotion, suggests that M100907, compared to dopamine receptor antagonists, will be less prone to induce psychomotor side-effects. Ongoing clinical studies will hopefully give the answers in the near future.

11C-diprenorphine binding in Huntington's disease: a comparison of region of interest analysis with statistical parametric mapping

We compare region of interest (ROI) analytical approaches with statistical parametric mapping (SPM) of 11C-diprenorphine positron emission tomography findings in five patients with Huntington's disease (HD) and nine age-matched controls. The ROI were placed on caudate, putamen, and an occipital reference area. Ratios of striatal-occipital uptake from averaged static images centered at 60 minutes showed a mean 20% reduction in caudate (P = 0.034) and 15% reduction in putamen (P = 0.095) receptor binding in the HD patients. Dynamic data from caudate and putamen ROI, together with a plasma tracer input function, were analyzed using spectral analysis to give regional impulse response functions. Regional data at 60 minutes after impulse showed a mean 29% decrease in caudate (P = 0.006) and 23% decrease in putamen (P = 0.029) opioid binding in the HD cohort. Parametric images of tracer binding also were produced with spectral analysis on a voxel basis. The images of the unit impulse response function at 60 minutes showed a mean 31% decrease in caudate (P = 0.005) and a 26% decrease in putamen binding (P = 0.011) in HD. The voxel-based parametric images were transformed into standard stereotactic space, and a between-group comparison (patient versus controls) was performed with SPM. This approach revealed symmetrical decreases in caudate (peak 40% decrease, z score = 4.38) and putamen opioid binding (peak 24% decrease, z score = 4.686) with additional nonhypothesized changes in cingulate, prefrontal, and thalamic areas. The significance and precision of changes measured with spectral analysis applied to dynamic data sets were superior to ROI-based ratio analysis on static images. The SPM replicated the striatal reductions in opioid binding in HD and detected additional nonpredicted changes. This study suggests that SPM is a valid alternative to conventional ROI analytical approaches for determining binding changes with positron emission tomography and may have advantages over region-based analyses in exploratory studies.

Sources and nature of heterogeneity in recombinant phenol hydroxylase derived from the basidiomycetous soil yeast Trichosporon cutaneum

Preparations of the dimeric flavoenzyme phenol hydroxylase derived from Trichosporon cutaneum were found to contain an active tetrameric form when the enzyme was produced in Escherichia coli. The relative content of the tetramer was estimated from scans of silver-stained native PAGE gels and/or size-exclusion chromatography (SEC). Proportions of up to 22% of the enzyme protein, depending on the growth temperature and the level of added inducer, were observed in independent cultures as well as in purified preparations. No tetramer was ever seen in cell extracts or purified preparations from T. cutaneum. Traces of higher multimers and of possibly deamidated species were also detected in preparations of the recombinant enzyme. The rate of enzyme production seems to be the major factor in promoting formation of the tetramer, whereas the specific growth rate of the fermentor culture appears to be of minor importance. The dimeric and the tetrameric forms were purified using either SEC or ion-exchange chromatography as a final step. The two purified species did not interchange under a variety of conditions, indicating that they are not undergoing rapid equilibria. The FAD of either form, as isolated by SEC, was present to a lower-than-expected extent of 2 equiv/dimer. However, by removing FAD and reconstituting the resulting apoproteins with the cofactor, the FAD content could be increased to 2 equiv. in the dimer and 3 equiv. in the tetramer. Both reconstituted forms exhibited absorption spectra identical with that of phenol hydroxylase from T. cutaneum as well as that of the recombinant enzyme. All spectra were equally perturbed by one equivalent of phenol per enzyme-attached FAD. The ratio of specific activities of the dimeric and the tetrameric forms was, however, lower than expected from the ratio of their FAD contents. The results are compatible with the notion that the tetramer consists of a native phenol hydroxylase dimer associated with a non-native one with a decreased ability to bind FAD, either in one or both of its constituent 'monomers'.

A model for sperm-egg binding and fusion based on ADAMs and integrins

Once a sperm meets an egg, several events must occur in order for fertilization to proceed. Sperm must bind to the zona pellucida, undergo the acrosome reaction, penetrate the zona pellucida and then bind to and fuse with the egg plasma membrane. Shortly thereafter, the egg must be activated for zygotic development. This review focuses on mammalian sperm-egg plasma membrane binding and fusion, and in particular on the roles of two families of cell-adhesion molecules, ADAMs and integrins, in this important union.

Effects of unilateral hearing loss on teacher responses to the SIFTER. Screening Instrument for Targeting Educational Risk

Eighteen school children with unilateral hearing loss were compared to their peers through administration of the Screening Instrument for Targeting Educational Risk (SIFTER) to their teachers. Results indicate that children with unilateral hearing loss are given SIFTER scores significantly lower than their peers in all five SIFTER areas of academics, attention, communication, participation, and behavior. Such results support previous findings regarding teachers' attitudes toward students with unilateral hearing loss and indicate a need for in-service education for the classroom teacher and special attention to the educational risks of such children.

Viral measurement by polymerase chain reaction-based assays in human immunodeficiency virus-infected infants

Serial samples from human immunodeficiency virus-infected infants in the first year of life were analyzed by quantitative human immunodeficiency virus polymerase chain reaction assays. Very high, persistent levels of plasma RNA and proviral DNA were detected throughout the study period, suggesting the absence of an effective immune response. Most patients had normal CD4 lymphocyte counts and were symptom free for the first 3 to 6 months despite high levels of viral replication. These findings support the evaluation of early intervention (before symptoms develop) and efforts to establish the predictive value of these assays.