Amyloid β (Aβ) aggregates are the primary component of senile plaques in Alzheimer disease (AD) patient’s brain. Aβ is known to bind p75 neurotrophin receptor (p75NTR) and mediates Aβ-induced neuronal death. Recently, we showed that NGF leads to p75NTR polyubiquitination, which promotes neuronal cell survival. Here, we demonstrate that Aβ stimulation impaired the p75NTR polyubiquitination. TRAF6 and p62 are required for polyubiquitination of p75NTR on NGF stimulation. Interestingly, we found that overexpression of TRAF6/p62 restored p75NTR polyubiquitination upon Aβ/NGF treatment. Aβ significantly reduced NF-κB activity by attenuating the interaction of p75NTR with IKKβ. p75NTR increased NF-κB activity by recruiting TRAF6/p62, which thereby mediated cell survival. These findings indicate that TRAF6/p62 abrogated the Aβ-mediated inhibition of p75NTR polyubiquitination and restored neuronal cell survival.
p75 neurotrophin receptor; TRAF6; p62; Amyloid β; Ubiquitination
A major drawback of internalizing monoclonal antibodies (mAbs) radioiodinated with direct electrophilic approaches is that tumor retention of radioactivity is compromised by the rapid washout of iodo-tyrosine, the primary labeled catabolite for mAbs labeled via this strategy. In our continuing efforts to develop more versatile residualizing labels that could overcome this problem, we have designed SIB-DOTA, a prosthetic labeling template that combines the features of the prototypical, dehalogenation resistant N-succinimidyl 3-iodobenzoate (SIB) with DOTA, a useful macrocyclic chelator for labeling with radiometals. Herein we describe the synthesis of the unlabeled standard of this prosthetic moiety, its protected tin precursor, and radioiodinated SIB-DOTA. An anti-EGFRvIII-reactive mAb, L8A4 was radiolabeled with [131I]SIB-DOTA in 27.1 ± 6.2% (n = 2) conjugation yields and its targeting properties to the same mAb labeled with [125I]SGMIB both in vitro and in vivo using U87MG·ΔEGFR cells and xenografts were compared. In vitro paired-label internalization assays showed that the intracellular radioactivity from [131I]SIB-DOTA-L8A4 was 21.4 ± 0.5% and 26.2 ± 1.1% of initially bound radioactivity at 16 and 24 h, respectively. In comparison, these values for [125I]SGMIB-L8A4 were 16.7 ± 0.5% and 14.9 ± 1.1%. Similarly, the SIB-DOTA prosthetic group provided better tumor targeting in vivo than SGMIB over 8 d period. These results suggest that SIB-DOTA warrants further evaluation as a residualizing agent for labeling internalizing mAbs including those targeted to EGFRvIII.
Monoclonal antibody; Internalization; Residualizing Labels; Radioiodine
Although small populations are expected to lose genetic diversity through genetic drift and inbreeding, a number of mechanisms exist that could minimize this genetic decline. Examples include mate choice for unrelated mates and fertilization patterns biased toward genetically dissimilar gametes. Both processes have been widely documented, but the long-term implications have received little attention. Here, we combined over 25 years of field data with high-resolution genetic data to assess the long-term impacts of biased fertilization patterns in the endangered North Atlantic right whale. Offspring have higher levels of microsatellite heterozygosity than expected from this gene pool (effect size = 0.326, P < 0.011). This pattern is not due to precopulatory mate choice for genetically dissimilar mates (P < 0.600), but instead results from postcopulatory selection for gametes that are genetically dissimilar (effect size = 0.37, P < 0.003). The long-term implication is that heterozygosity has slowly increased in calves born throughout the study period, as opposed to the slight decline that was expected. Therefore, this mechanism represents a natural means through which small populations can mitigate the loss of genetic diversity over time.
Genetic incompatibility; genetic variation; mate choice; mate incompatibility; right whale
To determine the effects of niacin on adiponectin and markers of adipose tissue inflammation in a mouse model of obesity.
Materials and Methods
Male C57BL/6 mice were placed on a control or high-fat diet (HFD) and were maintained on such diets for the duration of the study. After 6 weeks on the control or high fat diets, vehicle or niacin treatments were initiated and maintained for 5 weeks. Identical studies were conducted concurrently in HCA2−/− (niacin receptor−/−) mice.
Niacin increased serum concentrations of the anti-inflammatory adipokine, adiponectin by 21% in HFD-fed wild-type mice, but had no effect on lean wild-type or lean or HFD-fed HCA2−/− mice. Niacin increased adiponectin gene and protein expression in the HFD-fed wild-type mice only. The increases in adiponectin serum concentrations, gene and protein expression occurred independently of changes in expression of PPARγ C/EBPα or SREBP-1c (key transcription factors known to positively regulate adiponectin gene transcription) in the adipose tissue. Further, niacin had no effect on adipose tissue expression of ERp44, Ero1-Lα, or DsbA-L (key ER chaperones involved in adiponectin production and secretion). However, niacin treatment attenuated HFD-induced increases in adipose tissue gene expression of MCP-1 and IL-1β in the wild-type HFD-fed mice. Niacin also reduced the expression of the pro-inflammatory M1 macrophage marker CD11c in HFD-fed wild-type mice.
Niacin treatment attenuates obesity-induced adipose tissue inflammation through increased adiponectin and anti-inflammatory cytokine expression and reduced pro-inflammatory cytokine expression in a niacin receptor-dependent manner.
The Afrotropical mosquito Anopheles gambiae sensu stricto (A. gambiae), a major vector of malaria, is currently undergoing speciation into the M and S molecular forms. These forms have diverged in larval ecology and reproductive behavior through unknown genetic mechanisms, despite considerable levels of hybridization. Previous genome-wide scans using gene-based microarrays uncovered divergence between M and S that was largely confined to gene-poor pericentromeric regions, prompting a speciation-with-ongoing-gene-flow model that implicated only ~3% of the genome near centromeres in the speciation process. Here, based on the complete M and S genome sequences, we report widespread and heterogeneous genomic divergence inconsistent with appreciable levels of inter-form gene flow, suggesting a more advanced speciation process and greater challenges to identify genes critical to initiating that process.
This study included a series of middle-aged male and female patients who presented with chronic anterior hemicord dysfunction progressing to paraplegia. Imaging of anterior thoracic cord displacement by either a dural adhesion or a dural defect with associated cord herniation is presented.
This is a retrospective review of cases referred to a tertiary neuroscience centre over a 19-year period. Imaging series were classified by two experienced neuroradiologists against several criteria and correlated with clinical examination and/or findings at surgery.
16 cases were available for full review. Nine were considered to represent adhesions (four confirmed surgically) and four to represent true herniation (three confirmed surgically). In the three remaining cases the diagnosis was radiologically uncertain.
The authors propose “thoracic anterior spinal cord adhesion syndrome” as a novel term to describe this patient cohort and suggest appropriate clinicoradiological features for diagnosis. Several possible aetiologies are also suggested, with disc rupture and inflammation followed by disc resorption and dural pocket formation being a possible mechanism predisposing to herniation at the extreme end of a clinicopathological spectrum.
Arthroplasty in the haemophiliac patient is associated with higher rates of infection and is traditionally performed in a younger age group. Despite this there is little evidence in the literature regarding revision arthroplasty in this cohort of patients. We describe the case of a periprosthetic fracture in a haemophiliac patient requiring revision arthroplasty, who did not consent to receiving blood products due to religious beliefs, with a successful outcome.
Most pathway and gene-set enrichment methods prioritize genes by their main effect and do not account for variation due to interactions in the pathway. A portion of the presumed missing heritability in genome-wide association studies (GWAS) may be accounted for through gene–gene interactions and additive genetic variability. In this study, we prioritize genes for pathway enrichment in GWAS of bipolar disorder (BD) by aggregating gene–gene interaction information with main effect associations through a machine learning (evaporative cooling) feature selection and epistasis network centrality analysis. We validate this approach in a two-stage (discovery/replication) pathway analysis of GWAS of BD. The discovery cohort comes from the Wellcome Trust Case Control Consortium (WTCCC) GWAS of BD, and the replication cohort comes from the National Institute of Mental Health (NIMH) GWAS of BD in European Ancestry individuals. Epistasis network centrality yields replicated enrichment of Cadherin signaling pathway, whose genes have been hypothesized to have an important role in BD pathophysiology but have not demonstrated enrichment in previous analysis. Other enriched pathways include Wnt signaling, circadian rhythm pathway, axon guidance and neuroactive ligand-receptor interaction. In addition to pathway enrichment, the collective network approach elevates the importance of ANK3, DGKH and ODZ4 for BD susceptibility in the WTCCC GWAS, despite their weak single-locus effect in the data. These results provide evidence that numerous small interactions among common alleles may contribute to the diathesis for BD and demonstrate the importance of including information from the network of gene–gene interactions as well as main effects when prioritizing genes for pathway analysis.
eigenvector centrality; epistasis network; evaporative cooling machine learning feature selection; pathway enrichment analysis; regression-based genetic association interaction network (reGAIN); SNPrank
The association between cancer, major surgery and venous thromboembolism (VTE) is well established. Multimodal therapy is increasingly being used as standard treatment for localised gastrointestinal cancer. The aim of this study was to examine the markers of pro-coagulation response and VTE risk in an exemplar multimodal model of pre-operative combination chemotherapy and radiation therapy, followed by complex cancer surgery.
Consecutive patients (n=36) with localised oesophageal cancer were studied at baseline after the first and second cycles of chemoradiation, and on post-operative days 1–28, and at 3, 6 and 9 months. Factors regulating the pro- and anti-coagulant response, as well as pro-inflammatory markers including NFκB activation in peripheral blood mononuclear cells, were examined. All patients received enoxaparin 40 mg s.c. postoperatively up to discharge, and underwent pulmonary CT-pulmonary angiography and venography on day 10 postoperatively.
Four (11%) non-fatal thromboembolic events were documented, all after hospital discharge. Neoadjuvant therapy before surgery activated factor VIII (FVIII) and pro-inflammatory NFκB, and increased D-dimers, pro-thrombin fragment 1+2 (F1+2) and the thrombin-anti-thrombin complex (TAT). Surgery significantly (P<0.05) increased pro-thrombin time (PT), activated partial thromboplastin time, fibrinogen, D-dimers, TAT, F1+2 and FVIII up to 6 months.
These data highlight the linked pro-coagulant and immunoinflammatory pathways in the multimodal management of oesophageal cancer, and suggest that the duration of current standard thromboprophylaxis regimens warrants further study.
oesophageal cancer; multimodal; pro-coagulant; immunoinflammation
Dental caries is one of the primary causes of tooth loss among adults. It is estimated to affect a majority of Americans aged 55 and older, with a disproportionately higher burden in disadvantaged populations. Although a number of treatments are currently in use for caries prevention in adults, evidence for their efficacy and effectiveness is limited.
The Prevention of Adult Caries Study (PACS) is a multicenter, placebo-controlled, double-blind, randomized clinical trial of the efficacy of a chlorhexidine (10% w/v) dental coating in preventing adult caries. Participants (n = 983) were recruited from four different dental delivery systems serving four diverse communities, including one American Indian population, and were randomized to receive either chlorhexidine or a placebo treatment. The primary outcome is the net caries increment (including non-cavitated lesions) from baseline to 13 months of follow-up. A cost-effectiveness analysis also will be considered.
This new dental treatment, if efficacious and approved for use by the Food and Drug Administration (FDA), would become a new in-office, anti-microbial agent for the prevention of adult caries in the United States.
Trial Registration Number
To evaluate a modified American College of Rheumatology 20 (mACR20) scoring system for patients with rheumatoid arthritis.
The data were evaluated from one study on patients with methotrexate (MTX)‐naive early rheumatoid arthritis (ERA) and another study on patients with DMARD‐refractory late rheumatoid arthritis (LRA). For mACR20 scoring, acute‐phase reactant measurements were excluded, and 20% improvement from baseline was determined by 2 or 3 of the 4 remaining ACR components.
For full joint counts with data from patients with ERA, marked differences favoured 25 mg etanercept (ETN) over 10 mg ETN by using the unmodified ACR20 (69% v 55%), the mACR203 of 4 (63% v 49%) and the mACR202 of 4 (72% v 58%). An assessment of 28 joints showed similar findings. In the trial on patients with LRA, considerably more patients in both ETN groups achieved a clinical response compared with placebo by using the ACR20, the mACR203 of 4 and the mACR202 of 4, whether using full or 28 joint counts. The mACR203 of 4 and full joint counts with data on patients with ERA showed a marked difference between the MTX and 10 mg ETN groups (63% v 49%), which was not observed with the ACR20.
Patterns of improvement indicated by mACR20 scores were consistent with standard ACR20 scores.
To estimate minimally important differences (MIDs) in scores for the modified Rodnan Skin Score (mRSS) and Health Assessment Questionnaire—Disability Index (HAQ‐DI) in a clinical trial on diffuse systemic sclerosis (SSc).
Participants and methods
134 people participated in a 2‐year, double‐blind, randomised clinical trial comparing efficacy of low‐dose and high‐dose d‐penicillamine in diffuse SSc. At 6, 12, 18 and 24 months, the investigator was asked to rate the change in the patient's health since entering the study: markedly worsened, moderately worsened, slightly worsened, unchanged, slightly improved, moderately improved or markedly improved. Patients who were rated as slightly improved were defined as the minimally changed subgroup and compared with patients rated as moderately or markedly improved.
The MID estimates for the mRSS improvement ranged from 3.2 to 5.3 (0.40–0.66 effect size) and for the HAQ‐DI from 0.10 to 0.14 (0.15–0.21 effect size). Patients who were rated to improve more than slightly were found to improve by 6.9–14.2 (0.86–1.77 effect size) on the mRSS and 0.21–0.55 (0.32–0.83 effect size) on the HAQ‐DI score.
MID estimates are provided for improvement in the mRSS and HAQ‐DI scores, which can help in interpreting clinical trials on patients with SSc and be used for sample size calculation for future clinical trials on diffuse SSc.
Plasmodium knowlesi is an intracellular malaria parasite whose natural vertebrate host is Macaca fascicularis (the ‘kra’ monkey); however, it is now increasingly recognized as a significant cause of human malaria, particularly in southeast Asia1,2. Plasmodium knowlesi was the first malaria parasite species in which antigenic variation was demonstrated3, and it has a close phylogenetic relationship to Plasmodium vivax4, the second most important species of human malaria parasite (reviewed in ref. 4). Despite their relatedness, there are important phenotypic differences between them, such as host blood cell preference, absence of a dormant liver stage or ‘hypnozoite’ in P. knowlesi, and length of the asexual cycle (reviewed in ref. 4). Here we present an analysis of the P. knowlesi (H strain, Pk1(A+) clone5) nuclear genome sequence. This is the first monkey malaria parasite genome to be described, and it provides an opportunity for comparison with the recently completed P. vivax genome4 and other sequenced Plasmodium genomes6-8. In contrast to other Plasmodium genomes, putative variant antigen families are dispersed throughout the genome and are associated with intrachromosomal telomere repeats. One of these families, the KIRs9, contains sequences that collectively match over one-half of the host CD99 extracellular domain, which may represent an unusual form of molecular mimicry.
To determine the long term safety profile of the tumour necrosis factor (TNF) antagonist etanercept in subjects with rheumatoid arthritis (RA), psoriatic arthritis (PsA), or ankylosing spondylitis (AS) aged ⩾65 years in comparison with subjects aged <65 years.
Safety data from an integrated database of 4322 subjects enrolled in 18 RA trials, 2 PsA trials, and 2 AS trials were analysed. Safety end points included subject incidence of all adverse events (AE), serious adverse events (SAE), infectious events (IE), medically important infections (MII), and deaths. Events of particular interest in subjects treated with TNF modulating biological treatments, including demyelinating diseases, tuberculosis, lymphomas, and cardiovascular diseases, were also evaluated.
The incidence of AE, SAE, IE, MII, and malignancies was not significantly raised in elderly subjects in comparison with subjects aged <65 years. No cases of tuberculosis were reported in the trials. Demyelinating diseases were seen only in subjects aged <65 years. The incidence and types of death in the elderly subjects were consistent with the expected rates for subjects of comparable age.
Etanercept is a generally safe and well tolerated biological agent for treatment of rheumatological diseases in the elderly, and the risk of AE in these studies was no greater in subjects aged ⩾65 years than in younger subjects.
geriatric; elderly; etanercept; safety; rheumatological diseases
To develop standards of care for head injury and thereby identify and prioritise areas of the service needing development; to report the findings from a survey of compliance with such standards in the Eastern region of UK.
The standards were collaboratively developed through an inclusive and iterative process of regional surveys, multidisciplinary conferences, and working groups, following a method similar to that used by the Society of British Neurological Surgeons. The standards cover seven topics relating to all aspects of service delivery, with standards within each objective. Each standard has been designated a priority level (A, B, or C). The standards were piloted using a self‐assessment questionnaire, completed by all 20 hospitals of the Eastern region.
Full compliance was 36% and a further 30% of standards were partially met across the region, with some areas of service delivery better than others. Seventy eight per cent of level A standards were either fully or partially met. Results were better in the north of the region compared with the south.
A survey of compliance with the head injury standards indicate that, with their whole systems approach and subject to further refinement, they are a useful method for identifying deficiencies in service provision and monitoring for quality of care both within organisations and regionally.
head injury; standards; health service research; NSF; long term conditions
Motivation: The development of genome-wide capabilities for genotyping has led to the practical problem of identifying the minimum subset of genetic variants relevant to the classification of a phenotype. This challenge is especially difficult in the presence of attribute interactions, noise and small sample size.
Methods: Analogous to the physical mechanism of evaporation, we introduce an evaporative cooling (EC) feature selection algorithm that seeks to obtain a subset of attributes with the optimum information temperature (i.e. the least noise). EC uses an attribute quality measure analogous to thermodynamic free energy that combines Relief-F and mutual information to evaporate (i.e. remove) noise features, leaving behind a subset of attributes that contain DNA sequence variations associated with a given phenotype.
Results: EC is able to identify functional sequence variations that involve interactions (epistasis) between other sequence variations that influence their association with the phenotype. This ability is demonstrated on simulated genotypic data with attribute interactions and on real genotypic data from individuals who experienced adverse events following smallpox vaccination. The EC formalism allows us to combine information entropy, energy and temperature into a single information free energy attribute quality measure that balances interaction and main effects.
Availability: Open source software, written in Java, is freely available upon request.
The social amoebae are exceptional in their ability to alternate between unicellular and multicellular forms. Here we describe the genome of the best-studied member of this group, Dictyostelium discoideum. The gene-dense chromosomes encode ~12,500 predicted proteins, a high proportion of which have long repetitive amino acid tracts. There are many genes for polyketide synthases and ABC transporters, suggesting an extensive secondary metabolism for producing and exporting small molecules. The genome is rich in complex repeats, one class of which is clustered and may serve as centromeres. Partial copies of the extrachromosomal rDNA element are found at the ends of each chromosome, suggesting a novel telomere structure and the use of a common mechanism to maintain both the rDNA and chromosomal termini. A proteome-based phylogeny shows that the amoebozoa diverged from the animal/fungal lineage after the plant/animal split, but Dictyostelium appears to have retained more of the diversity of the ancestral genome than either of these two groups.
Venous thromboembolism (VTE) is responsible for an estimated 25 000 deaths per annum in UK hospital practice. It is well established that many of these deaths could be prevented through the use of appropriate thromboprophylaxis. This issue is of particular relevance in oncology practice, where the risks of VTE and bleeding are both significantly higher than those observed in general medical patients. Cancer patients with in-dwelling central venous catheters (CVCs) are at particularly high risk of developing thrombotic complications. However, the literature has produced conflicting conclusions regarding the efficacy of using routine primary thromboprophylaxis in these patients. Indeed such is the level of confusion around this topic, that the most recent version of the American College of Chest Physicians (ACCP) guidelines published in 2004 actually reversed their previous recommendation (published in 2001). Nevertheless, minidose warfarin continues to be routinely used in many oncology centres in the UK. In this article, we have performed a systematic review of the published literature regarding the efficacy and the risks, associated with using thromboprophylaxis (either minidose warfarin or low-dose LMWH) in cancer patients with CVC. On the basis of this evidence, we conclude that there is no proven role for using such thromboprophylaxis. However, asymptomatic CVC-related venous thrombosis remains common, and further more highly powered studies of better design are needed in order to define whether specific subgroups of cancer patients might benefit from receiving thromboprophylaxis.
central venous catheter; malignancy; thrombosis; antithrombotic prophylaxis
Ring chromosomes are estimated to occur in 3/10 000 newborns and the simultaneous occurrence of two autosomal rings must be a very rare event. Recently, the characterisation of these markers using fluorescence in situ hybridisation (FISH) has greatly enhanced cytogenetic-phenotypic correlations in patients with these marker chromosomes. This kind of analysis enabled us to clarify a unique karyotype containing a r(1) and a r(16) in identical twins born after a 26 week gestation with minimal somatic abnormalities. The origin of the rings was identified using α satellite and whole chromosome painting probes. FISH analysis showed the same abnormal female karyotype in both twins, 48,XX,+r(1)(p13q21),+r(16)(p11q11).ish r(1) (D1Z5+,wcp1+), r(16)(D16Z2+,wcp16+) in about two thirds of the cells. Each also had minor clones with a normal female karyotype or with one or the other supernumerary ring. Half of the r(1) contained CBG band negative material and the r(16) appeared to be totally CBG band positive. These twins represent the second report of the simultaneous occurrence of multiple autosomal rings. Their description may help to delineate a new chromosome disorder and shows the usefulness of FISH analysis.
Keywords: ring chromosome 1; ring chromosome 16; marker chromosomes; whole chromosome painting probes
Phylogenetic analysis of tetracycline resistance genes, which confer resistance due to the efflux of tetracycline from the cell catalyzed by drug:H+ antiport and share a common structure with 12 transmembrane segments (12-TMS), suggested the monophyletic origin of these genes. With a high degree of confidence, this tet subcluster unifies 11 genes encoding tet efflux pumps and includes tet(A), tet(B), tet(C), tet(D), tet(E), tet(G), tet(H), tet(J), tet(Y), tet(Z), and tet(30). Phylogeny-aided alignments were used to design a set of PCR primers for detection, retrieval, and sequence analysis of the corresponding gene fragments from a variety of bacterial and environmental sources. After rigorous validation with the characterized control tet templates, this primer set was used to determine the genotype of the corresponding tetracycline resistance genes in total DNA of swine feed and feces and in the lagoons and groundwater underlying two large swine production facilities known to be impacted by waste seepage. The compounded tet fingerprint of animal feed was found to be tetCDEHZ, while the corresponding fingerprint of total intestinal microbiota was tetBCGHYZ. Interestingly, the tet fingerprints in geographically distant waste lagoons were identical (tetBCEHYZ) and were similar to the fecal fingerprint at the third location mentioned above. Despite the sporadic detection of chlortetracycline in waste lagoons, no auxiliary diversity of tet genes in comparison with the fecal diversity could be detected, suggesting that the tet pool is generated mainly in the gut of tetracycline-fed animals, with a negligible contribution from selection imposed by tetracycline that is released into the environment. The tet efflux genes were found to be percolating into the underlying groundwater and could be detected as far as 250 m downstream from the lagoons. With yet another family of tet genes, this study confirmed our earlier findings that the antibiotic resistance gene pool generated in animal production systems may be mobile and persistent in the environment with the potential to enter the food chain.