Different prognostic values of KRAS exon 2 submutations and BRAF V600E mutation in microsatellite stable (MSS) and unstable (MSI) stage III colon cancer: an ACCENT/IDEA pooled analysis of seven trials

BACKGROUND

The prognostic value of KRAS and BRAFV600E mutations in stage III colon cancer (CC) remains controversial and has never been clearly analyzed in patients with microsatellite instability-high (MSI-H) tumors due to sample size limitations. Data are also lacking for KRAS submutations and prognosis.

PATIENTS AND METHODS

We examined clinicopathological variables and prognosis in patients with surgically resected stage III CC who participated in seven clinical trials from the ACCENT/IDEA databases. Associations between KRAS exon 2 and BRAFV600E mutations and time to recurrence (TTR), overall survival (OS), and survival after recurrence (SAR) were assessed using a Cox model. We also analyzed the prognostic value of KRAS exon 2 submutations.

RESULTS

Among 8460 patients, 11.4% had MSI-H status. In the MSI-H group, BRAFV600E, KRAS exon 2 mutants, and double-wild-type statuses were detected in 40.6%, 18.1%, and 41.3%, respectively, whereas and in the microsatellite stable (MSS) group, these were detected in 7.7%, 38.6%, and 53.8%, respectively. In the MSS group, 5-year TTR rates of 61.8%, 66.3%, and 72.9% were observed among patients with BRAFV600E, KRAS exon 2 mutants, and those who were DWT, respectively [adjusted hazard ratio (HR) = 1.58 and 1.31, both P < 0.001]. In the MSI-H group, 5-year TTR rates did not differ significantly among the mutated subgroups. Similar results were found for OS. However, survival after relapse was significantly shorter in the KRAS exon 2- and BRAFV600E-mutated patients in both MSS (adjusted HR = 2.06 and 1.15; both P < 0.05) and MSI-H (adjusted HR = 1.99 and 1.81; both P < 0.05) groups. In the MSS group, KRAS exon 2 mutations were associated with TTR, but only p.G12C, p.G12D, and p.G13D were associated with poor outcomes after disease recurrence.

CONCLUSIONS

Testing for both KRAS and BRAFV600E mutations in stage III patients should be considered as they can better define individual patient prognosis, and may also enable patient selection for (neo)adjuvant trials dedicated to specific molecular subtypes with poor prognosis.

Individual cell types in C. elegans age differently and activate distinct cell-protective responses

Aging is characterized by a global decline in physiological function. However, by constructing a complete single-cell gene expression atlas, we find that Caenorhabditis elegans aging is not random in nature but instead is characterized by coordinated changes in functionally related metabolic, proteostasis, and stress-response genes in a cell-type-specific fashion, with downregulation of energy metabolism being the only nearly universal change. Similarly, the rates at which cells age differ significantly between cell types. In some cell types, aging is characterized by an increase in cell-to-cell variance, whereas in others, variance actually decreases. Remarkably, multiple resilience-enhancing transcription factors known to extend lifespan are activated across many cell types with age; we discovered new longevity candidates, such as GEI-3, among these. Together, our findings suggest that cells do not age passively but instead react strongly, and individualistically, to events that occur during aging. This atlas can be queried through a public interface.

CXD101 and nivolumab in patients with metastatic microsatellite-stable colorectal cancer (CAROSELL): a multicentre, open-label, single-arm, phase II trial

BACKGROUND

Patients with microsatellite stable (MSS) colorectal carcinoma (CRC) do not respond to immune checkpoint inhibitors. Preclinical models suggested synergistic anti-tumour activity combining CXD101 and anti-programmed cell death protein 1 treatment; therefore, we assessed the clinical combination of CXD101 and nivolumab in heavily pre-treated patients with MSS metastatic CRC (mCRC).

PATIENTS AND METHODS

This single-arm, open-label study enrolled patients aged 18 years or older with biopsy-confirmed MSS CRC; at least two lines of systemic anticancer therapies (including oxaliplatin and irinotecan); at least one measurable lesion; Eastern Cooperative Oncology Group performance status of 0, 1 or 2; predicted life expectancy above 3 months; and adequate organ and bone marrow function. Nine patients were enrolled in a safety run-in study to define a tolerable combination schedule of CXD101 and nivolumab, followed by 46 patients in the efficacy assessment phase. Patients in the efficacy assessment cohort were treated orally with 20 mg CXD101 twice daily for 5 consecutive days every 3 weeks, and intravenously with 240 mg nivolumab every 2 weeks. The primary endpoint was immune disease control rate (iDCR).

RESULTS

Between 2018 and 2020, 55 patients were treated with CXD101 and nivolumab. The combination therapy was well tolerated with the most frequent grade 3 or 4 adverse events being neutropenia (18%) and anaemia (7%). Immune-related adverse reactions commonly ascribed to checkpoint inhibitors were surprisingly rare although we did see single cases of pneumonitis, hypothyroidism and hypopituitarism. There were no treatment-related deaths. Of 46 patients assessable for efficacy, 4 (9%) achieved partial response and 18 (39%) achieved stable disease, translating to an immune disease control rate of 48%. The median overall survival (OS) was 7.0 months (95% confidence interval 5.13-10.22 months).

CONCLUSIONS

The primary endpoint was met in this phase II study, which showed that the combination of CXD101 and nivolumab, at full individual doses in the treatment of advanced or metastatic MSS CRC, was both well tolerated and efficacious.

Amoebic crab disease (ACD) in edible crab Cancer pagurus from the English Channel, UK

The genera Paramoeba and Neoparamoeba (Amoebozoa, Dactylopodida, Paramoebidae) include well-known opportunistic pathogens associated with fish (N. peruans; amoebic gill disease), lobsters, molluscs and sea urchins, but only rarely with crabs (grey crab disease of blue crabs). Following reports of elevated post-capture mortality in edible crabs Cancer pagurus captured from a site within the English Channel fishery in the UK, a novel disease (amoebic crab disease, ACD) was detected in significant proportions of the catch. We present histopathological, transmission electron microscopy and molecular phylogenetic data, showing that this disease is defined by colonization of haemolymph, connective tissues and fixed phagocytes by amoeboid cells, leading to tissue destruction and presumably death in severely diseased hosts. The pathology was strongly associated with a novel amoeba with a phylogenetic position on 18S rRNA gene trees robustly sister to Janickina pigmentifera (which groups within the current circumscription of Paramoeba/Neoparamoeba), herein described as Janickina feisti n. sp. We provide evidence that J. feisti is associated with ACD in 50% of C. pagurus sampled from the mortality event. A diversity of other paramoebid sequence types, clustering with known radiations of N. pemaquidensis and N. aestuarina and a novel N. aestuarina sequence type, was detected by PCR in most of the crabs investigated, but their detection was much less strongly associated with clinical signs of disease. The discovery of ACD in edible crabs from the UK is discussed relative to published historical health surveys for this species.

Microbiomics: The Next Pillar of Precision Medicine and Its Role in African Healthcare

Limited access to technologies that support early monitoring of disease risk and a poor understanding of the geographically unique biological and environmental factors underlying disease, represent significant barriers to improved health outcomes and precision medicine efforts in low to middle income countries. These challenges are further compounded by the rich genetic diversity harboured within Southern Africa thus necessitating alternative strategies for the prediction of disease risk and clinical outcomes in regions where accessibility to personalized healthcare remains limited. The human microbiome refers to the community of microorganisms (bacteria, archaea, fungi and viruses) that co-inhabit the human body. Perturbation of the natural balance of the gut microbiome has been associated with a number of human pathologies, and the microbiome has recently emerged as a critical determinant of drug pharmacokinetics and immunomodulation. The human microbiome should therefore not be omitted from any comprehensive effort towards stratified healthcare and would provide an invaluable and orthogonal approach to existing precision medicine strategies. Recent studies have highlighted the overarching effect of geography on gut microbial diversity as it relates to human health. Health insights from international microbiome datasets are however not yet verified in context of the vast geographical diversity that exists throughout the African continent. In this commentary we discuss microbiome research in Africa and its role in future precision medicine initiatives across the African continent.

Prognosis of microsatellite instability and/or mismatch repair deficiency stage III colon cancer patients after disease recurrence following adjuvant treatment: results of an ACCENT pooled analysis of seven studies

BACKGROUND

Microsatellite instable/deficient mismatch repair (MSI/dMMR) metastatic colorectal cancers have been reported to have a poor prognosis. Frequent co-occurrence of MSI/dMMR and BRAFV600E complicates the association.

PATIENTS AND METHODS

Patients with resected stage III colon cancer (CC) from seven adjuvant studies with available data for disease recurrence and MMR and BRAFV600E status were analyzed. The primary end point was survival after recurrence (SAR). Associations of markers with SAR were analyzed using Cox proportional hazards models adjusted for age, gender, performance status, T stage, N stage, primary tumor location, grade, KRAS status, and timing of recurrence.

RESULTS

Among 2630 patients with cancer recurrence (1491 men [56.7%], mean age, 58.5 [19-85] years), multivariable analysis revealed that patients with MSI/dMMR tumors had significantly longer SAR than did patients with microsatellite stable/proficient MMR tumors (MSS/pMMR) (adjusted hazard ratio [aHR], 0.82; 95% CI [confidence interval], 0.69-0.98; P = 0.029). This finding remained when looking at patients treated with standard oxaliplatin-based adjuvant chemotherapy regimens only (aHR, 0.76; 95% CI, 0.58-1.00; P = 0.048). Same trends for SAR were observed when analyzing MSI/dMMR versus MSS/pMMR tumor subgroups lacking BRAFV600E (aHR, 0.84; P = 0.10) or those harboring BRAFV600E (aHR, 0.88; P = 0.43), without reaching statistical significance. Furthermore, SAR was significantly shorter in tumors with BRAFV600E versus those lacking this mutation (aHR, 2.06; 95% CI, 1.73-2.46; P < 0.0001), even in the subgroup of MSI/dMMR tumors (aHR, 2.65; 95% CI, 1.67-4.21; P < 0.0001). Other factors associated with a shorter SAR were as follows: older age, male gender, T4/N2, proximal primary tumor location, poorly differentiated adenocarcinoma, and early recurrence.

CONCLUSIONS

In stage III CC patients recurring after adjuvant chemotherapy, and before the era of immunotherapy, the MSI/dMMR phenotype was associated with a better SAR compared with MSS/pMMR. BRAFV600E mutation was a poor prognostic factor for both MSI/dMMR and MSS/pMMR patients.

TRIAL IDENTIFICATION NUMBERS

NCT00079274, NCT00265811, NCT00004931, NCT00004931, NCT00026273, NCT00096278, NCT00112918.

Mathematical modelling of the vitamin C clock reaction

Chemical clock reactions are characterized by a relatively long induction period followed by a rapid 'switchover' during which the concentration of a clock chemical rises rapidly. In addition to their interest in chemistry education, these reactions are relevant to industrial and biochemical applications. A substrate-depletive, non-autocatalytic clock reaction involving household chemicals (vitamin C, iodine, hydrogen peroxide and starch) is modelled mathematically via a system of nonlinear ordinary differential equations. Following dimensional analysis, the model is analysed in the phase plane and via matched asymptotic expansions. Asymptotic approximations are found to agree closely with numerical solutions in the appropriate time regions. Asymptotic analysis also yields an approximate formula for the dependence of switchover time on initial concentrations and the rate of the slow reaction. This formula is tested via 'kitchen sink chemistry' experiments, and is found to enable a good fit to experimental series varying in initial concentrations of both iodine and vitamin C. The vitamin C clock reaction provides an accessible model system for mathematical chemistry.

[Medicaments and oral healthcare. Systematic review of the -literature assessing the effect of drugs on the salivary glands]

Evidence-based reviews of drugs causing medication-induced salivary gland dysfunction, such as xerostomia (sensation of oral dryness) and subjective sialorrhea are lacking. To compile a list of medicaments that influence salivary gland function, electronic databases were searched for relevant articles published up to June 2013. A total of 269 papers out of 3,867 records located satisfied the inclusion criteria (relevance, quality of methodology, strength of evidence). A total of 56 active substances with a higher level of evidence and 50 active substances with a moderate level of evidence of causing salivary gland dysfunction are described in this article. While xerostomia was a commonly reported outcome, the objective effect on salivary secretion was rarely measured. Xerostomia was, moreover, mostly reported as a negative side effect instead of the intended effect of that drug. A comprehensive list of medications having documented effects on salivary gland function or symptoms was compiled, which may assist practitioners in assessing patients who complain of dry mouth while taking medications.

Prognostic markers for colorectal cancer: estimating ploidy and stroma

Background

We report here the prognostic value of ploidy and digital tumour-stromal morphometric analyses using material from 2624 patients with early stage colorectal cancer (CRC).

Patients and methods

DNA content (ploidy) and stroma-tumour fraction were estimated using automated digital imaging systems and DNA was extracted from sections of formalin-fixed paraffin-embedded (FFPE) tissue for analysis of microsatellite instability. Samples were available from 1092 patients recruited to the QUASAR 2 trial and two large observational series (Gloucester, n = 954; Oslo University Hospital, n = 578). Resultant biomarkers were analysed for prognostic impact using 5-year cancer-specific survival (CSS) as the clinical end point.

Results

Ploidy and stroma-tumour fraction were significantly prognostic in a multivariate model adjusted for age, adjuvant treatment, and pathological T-stage in stage II patients, and the combination of ploidy and stroma-tumour fraction was found to stratify these patients into three clinically useful groups; 5-year CSS 90% versus 83% versus 73% [hazard ratio (HR) = 1.77 (95% confidence interval (95% CI): 1.13-2.77) and HR = 2.95 (95% CI: 1.73-5.03), P < 0.001].

Conclusion

A novel biomarker, combining estimates of ploidy and stroma-tumour fraction, sampled from FFPE tissue, identifies stage II CRC patients with low, intermediate or high risk of CRC disease specific death, and can reliably stratify clinically relevant patient sub-populations with differential risks of tumour recurrence and may support choice of adjuvant therapy for these individuals.

Psychometric properties of the Irish Management Standards Indicator Tool

BACKGROUND

Work Positive is Ireland's national policy initiative to control work-related stress. Since the introduction of the UK Health and Safety Executive's Management Standards (MS) in 2004, a number of studies have been undertaken to assess the potential adaptation of the MS framework within Ireland.

AIMS

To investigate the dimensionality, reliability and validity of the Irish version of the MS Indicator Tool (ROI-MSIT).

METHODS

Between February 2011 and June 2014, we collected data from a wide range of public and private sector organizations that used the ROI-MSIT. In addition to the ROI-MSIT, respondents completed the WHO-Five Well-being Index (WHO-5). Exploratory factor analysis (EFA) was used to determine whether the ROI-MSIT maintained the structure of the UK instrument. The internal consistency of the ROI-MSIT was also assessed to determine its reliability, while its criterion-related validity was explored through correlation analysis with the WHO-5.

RESULTS

Data were collected from 7377 participants. The factor structure of the ROI-MSIT consisted of six factors; the Demands, Control, Peer Support, Relationships and Role factors were equivalent to the original UK factors. Like the Italian version, a principal factor emerged that combined the Manager Support and Change domains. Cronbach's alpha scores ranged from 0.75 to 0.91. Finally, the ROI-MSIT's subscales and WHO-5 were positively correlated (r = 0.42-0.59, P < 0.001).

CONCLUSIONS

The ROI-MSIT is reliable and valid, with a factor structure similar to the original UK instrument and the Italian MSIT. Further psychometric evaluation of the ROI-MSIT is recommended.

BRCA1, BRCA2 and PALB2 mutations and CHEK2 c.1100delC in different South African ethnic groups diagnosed with premenopausal and/or triple negative breast cancer

Background

Current knowledge of the aetiology of hereditary breast cancer in the four main South African population groups (black, coloured, Indian and white) is limited. Risk assessments in the black, coloured and Indian population groups are challenging because of restricted information regarding the underlying genetic contributions to inherited breast cancer in these populations. We focused this study on premenopausal patients (diagnosed with breast cancer before the age of 50; n = 78) and triple negative breast cancer (TNBC) patients (n = 30) from the four South African ethnic groups. The aim of this study was to determine the frequency and spectrum of germline mutations in BRCA1, BRCA2 and PALB2 and to evaluate the presence of the CHEK2 c.1100delC allele in these patients.

Methods

In total, 108 South African breast cancer patients underwent mutation screening using a Next-Generation Sequencing (NGS) approach in combination with Multiplex Ligation-dependent Probe Amplification (MLPA) to detect large rearrangements in BRCA1 and BRCA2.

Results

In 13 (12 %) patients a deleterious mutation in BRCA1/2 was detected, three of which were novel mutations in black patients. None of the study participants was found to have an unequivocal pathogenic mutation in PALB2. Two (white) patients tested positive for the CHEK2 c.1100delC mutation, however, one of these also carried a deleterious BRCA2 mutation. Additionally, six variants of unknown clinical significance were identified (4 in BRCA2, 2 in PALB2), all in black patients. Within the group of TNBC patients, a higher mutation frequency was obtained (23.3 %; 7/30) than in the group of patients diagnosed before the age of 50 (7.7 %; 6/78).

Conclusion

This study highlights the importance of evaluating germline mutations in major breast cancer genes in all of the South African population groups. This NGS study shows that mutation analysis is warranted in South African patients with triple negative and/or in premenopausal breast cancer.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-015-1913-6) contains supplementary material, which is available to authorized users.

Paradoxium irvingi n.gen. n.sp. (Microsporidia) infecting the musculature of European pink shrimp Pandalus montagui

This paper utilises histological, ultrastructure and molecular phylogenetic data to describe a novel genus and species (Paradoxium irvingi n.gen., n.sp.) within clade 5 of the phylum Microsporidia. The parasite infects the musculature of the pink shrimp Pandalus montagui captured from United Kingdom waters. The novel microsporidium is morphologically and phylogenetically dissimilar to its nearest phylogenetic branch relative Thelohania butleri infecting the sister shrimp taxon Pandalus jordani. Furthermore, it is morphologically distinct from the type species of the genus Thelohania, Thelohania giardi infecting European brown shrimp Crangon crangon. Since phylogenetic data pertaining to type T. giardi is not currently available, our discovery places some doubt on the likelihood that T. butleri represents the proposed surrogate for the type taxon. Further it demonstrates potential for significant morphological plasticity in this clade of muscle-infecting microsporidians of crustaceans which contains the genera Myospora, Cucumispora, Thelohania, and now Paradoxium. Since it cannot be stated with certainty that T. butleri (or other taxa within the clade) represent true close relatives of T. giardi, clarity on this issue will only occur with re-discovery and genotyping of type T. giardi infecting C. crangon from European waters.

The impact of two workplace-based health risk appraisal interventions on employee lifestyle parameters, mental health and work ability: results of a randomized controlled trial

Health risk appraisals (HRA) are a common type of workplace health promotion programme offered by American employers. In the United Kingdom, evidence of their effectiveness for promoting health behaviour change remains inconclusive. This randomized controlled trial examined the effects of two HRA interventions on lifestyle parameters, mental health and work ability in a UK context. A total of 180 employees were randomized into one of three groups: Group A (HRA augmented with health promotion and education activities), Group B (HRA only) and Group C (control, no intervention). After 12 months, changes in mean scoring in 10 lifestyle, mental health and work ability indices were compared, Groups A and B demonstrated non-significant improvements in 70% and 80%, respectively, compared with controls (40%). Odds ratios revealed that, compared with the control group, Group A was 29.2 (95% CI: 9.22-92.27) times more likely to report a perceived change in lifestyle behaviour; Group B 4.4 times (95% CI: 1.65-11.44). In conclusion, participation in the HRA was associated with a higher likelihood of perceived lifestyle behaviour change which was further increased in the augmented HRA group, thereby providing preliminary evidence that HRA and augmented HRA in particular may help UK employees make positive healthy lifestyle changes.

Movement time in an underwater environment

The effect of an underwater environment on the human motor capacity, as measured by Fitts' Law, was determined. Five Ss performed a reciprocal tapping task both on land and underwater. The results showed that movement time (MT) was significantly slower (p < 01) underwater than on land. Underwater the amplitude of the movement was found to have a greater influence on MT than the required precision of the movement. On land the reverse was found to be true with movement precision having a greater influence on MT.

Persistent increase of blood lead level and suppression of δ-ALAD activity in northern bobwhite quail orally dosed with even a single 2-mm spent lead shot

Birds that display grit ingestion behavior are potentially at risk of lead (Pb) poisoning from mistaken ingestion of spent Pb shot pellets. The majority of available studies designed to assess such risk have used unspent shot pellets rather than field-obtained spent shot, which is oxidized and otherwise changed by weathering. Available studies also often administered more or heavier shot pellets to a bird than it might be expected to ingest. The current study dosed northern bobwhite quail (Colinus virginianus) weighing 194.6 ± 23.1 g (female birds) and 199.3 ± 12.2 g (male birds) with one to three spent no. 9 Pb shot collected from a skeet range, with particular interest in the toxicity that may occur from ingestion of a single 2-mm, 50 mg shot. An 8 week post-dosing clinical observation period was employed, over which feed consumption, body weight, blood Pb levels, and a battery of blood physiological parameters were made. Weight loss occurred in the birds, including male birds dosed with one Pb pellet. Erythrocyte delta aminolevulinic acid dehydratase (δ-ALAD) levels were decreased for the duration of the study across exposures and to levels associated with injury in wild bird populations. Decreased ALAD was particularly severe in female birds dosed with one Pb pellet and was still 92 % decreased at 8 weeks after dosing. Together, these results suggest that inadvertent ingestion of a single no. 9 Pb shot pellet can adversely affect the health of northern bobwhite quail.

TYPES OF ALBINISM IN THE BLACK SOUTHERN AFRICA POPULATION

BACKGROUND

Oculocutaneous albinism (OCA) is the most common inherited disorder in Southern African blacks and several types have been described. Molecular techniques, where available, can be used to confirm a clinical diagnosis and the type of OCA, if necessary, and for prenatal diagnosis.

OBJECTIVES

To investigate and classify the different types of albinism commonly found and to determine the clinical implications for each type.

DESIGN

A descriptive survey.

SETTING

Gauteng province, South Africa, and Lesotho.

SUBJECTS

Three groups of subjects with OCA (96 from a genetics clinic, 62 from a dermatology clinic, and 31 from community surveys) from the black African population participated.

MAIN OUTCOME MEASURES

Subjects underwent clinical and/or dermatological examinations and were then classified according to type of OCA.

RESULTS

Four forms of OCA were identified: most (82%) subjects had OCA2 (a tyrosinase- positive type) with three sub-types: those without large freckles (ephelides) on exposed areas (named OCA 2a in this study), those with such freckles (named OCA 2b), and those with brown albinism (BOCA); the remainder had red/rufous albinism, ROCA (OCA 3). The four forms could be distinguished from each other clinically without using molecular genetic testing.

CONCLUSION

The most common types of albinism found in the black population of Southern Africa are OCA2 and OCA3. Given the high prevalence of the disorder, together with the high risk of skin cancer, and the recent persecution of affected individuals in certain East African countries, these findings and their clinical implications have significance in terms of both education and awareness for health professionals and lay people caring for those with albinism.

A combinatorial semaphorin code instructs the initial steps of sensory circuit assembly in the Drosophila CNS

Longitudinal axon fascicles within the Drosophila embryonic CNS provide connections between body segments and are required for coordinated neural signaling along the anterior-posterior axis. We show here that establishment of select CNS longitudinal tracts and formation of precise mechanosensory afferent innervation to the same CNS region are coordinately regulated by the secreted semaphorins Sema-2a and Sema-2b. Both Sema-2a and Sema-2b utilize the same neuronal receptor, plexin B (PlexB), but serve distinct guidance functions. Localized Sema-2b attraction promotes the initial assembly of a subset of CNS longitudinal projections and subsequent targeting of chordotonal sensory afferent axons to these same longitudinal connectives, whereas broader Sema-2a repulsion serves to prevent aberrant innervation. In the absence of Sema-2b or PlexB, chordotonal afferent connectivity within the CNS is severely disrupted, resulting in specific larval behavioral deficits. These results reveal that distinct semaphorin-mediated guidance functions converge at PlexB and are critical for functional neural circuit assembly.

High hydrostatic pressure processing of murine norovirus 1-contaminated oysters inhibits oral infection in STAT-1(-/-)-deficient female mice

We have previously demonstrated that high pressure processing (HPP) is effective in preventing in vitro replication of murine norovirus strain 1 (MNV-1), a human norovirus surrogate, in a monocyte cell line following extraction from MNV-1-contaminated oysters. In the present study, the efficacy of HPP to prevent in vivo replication within mice fed HPP-treated MNV-1-seeded oyster extracts was evaluated. Oyster homogenate extracts seeded with MNV-1 were given 5-min, 400-MPa (58,016-psi) treatments and orally gavaged into immunodeficient (STAT-1(-/-)) female mice. Mice orally gavaged with HPP-treated MNV-1 showed significant (P ≤ 0.05) weight loss leading to enhanced morbidity, whereas those given 100 and 200 PFU of HPP-treated MNV-1 were comparable to uninfected controls. MNV-1 was detected, via real-time PCR, within the liver, spleen, and brain of all mice fed non-HPP-treated homogenate but was not detected in the tissues of mice fed HPP-treated homogenates or in uninfected control mice. Hepatocellular necrosis and lymphoid depletion in the spleen were observed in non-HPP-treated MNV-1 mice only. These results clearly show that HPP prevents MNV-1 infection in vivo and validates that viral inactivation by HPP in vitro is essentially equivalent to that in vivo. Further, the data suggest that HPP may be an effective food processing intervention for norovirus-contaminated shellfish and thus may decrease risk to both immunocompromised and immunocompetent individuals who consume shellfish.

Management of the patient and family with neurofibromatosis 2: a consensus conference statement

A consensus conference on neurofibromatosis 2 (NF2) was held in 2002 at the request of the United Kingdom (UK) Neurofibromatosis Association, with particular emphasis on vestibular schwannoma (VS) surgery. NF2 patients should be managed at specialty treatment centres, whose staff has extensive experience with the disease. All NF2 patients and their families should have access to genetic testing because presymptomatic diagnosis improves the clinical management of the disease. Some clinical manifestations of NF2, such as ocular abnormalities, can be detected in infancy; therefore, clinical screening for at-risk members of NF2 families can start at birth, with the first magnetic resonance (MRI) scan at 10-12 years of age. Minimal interference, maintenance of quality of life, and conservation of function or auditory rehabilitation are the cornerstones of NF2 management, and the decision points to achieve these goals for patients with different clinical presentations are discussed.

An enhanced postnatal autoimmune profile in 24 week-old C57BL/6 mice developmentally exposed to TCDD

Developmental exposure of mice to the environmental contaminant and AhR agonist, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), causes persistent postnatal suppression of T cell-mediated immune responses. The extent to which prenatal TCDD may induce or exacerbate postnatal autoimmune disease remains unknown. In the present study, time-pregnant high affinity AhR C57BL/6 mice received a single oral administration of 0, 2.5, or 5 microg/kg TCDD on gestation day (gd) 12. Offspring of these mice (n=5/gender/treatment) were evaluated at 24 weeks-of-age and showed considerable immune dysregulation that was often gender-specific. Decreased thymic weight and percentages of CD4(+)CD8(+) thymocytes, and increased CD4(+)CD8(-) thymocytes, were present in the female but not male offspring. Males but not females showed decreased CD4(-)CD8(+) T cells, and increased Vbeta3(+) and Vbeta17a(+) T cells, in the spleen. Males but not females also showed increased percentages of bone marrow CD24(-)B220(+) B cell progenitors. Antibody titers to dsDNA, ssDNA and cardiolipin displayed increasing trends in both male and female mice, reaching significance for anti-dsDNA in both genders and for ssDNA in males at 5 microg/kg TCDD. Immunofluorescent staining of IgG and C3 deposition in kidney glomeruli increased in both genders of prenatal TCDD-exposed mice, suggestive of early stages of autoimmune glomerulonephritis. Collectively, these results show that exposure to TCDD during immune system development causes persistent humoral immune dysregulation as well as altered cell-mediated responses, and induces an adult profile of changes suggestive of increased risk for autoimmune disease.

Quantifying noise levels of intercellular signals

Cells often measure their local environment via the interaction of diffusible chemical signals with cell surface receptors. At the level of a single receptor, this process is inherently stochastic, but cells can contain many such receptors which can reduce the variability in the detected signal by suitable averaging. Here, we use explicit Monte Carlo simulations and analytical calculations to characterize the noise level as a function of the number of receptors. We show that the residual level approaches zero and that the correlation time, i.e., the waiting time needed to obtain statistically independent data, diverges, both for large receptor numbers. This result has important implications for such processes as eukaryotic chemotaxis.

Low-grade osteosarcoma of the ethmoid sinus

Osteosarcoma uncommonly arises in craniofacial bones and has only rarely been reported to arise in the ethmoid sinus. Most primary osteosarcomas arising in paranasal sinuses are high-grade malignancies. A low-grade osteosarcoma arising in the ethmoid sinus has not previously been described. We report the clinical, radiological and histological findings of a case of low-grade (parosteal osteosarcoma-like) osteosarcoma which arose in the ethmoid sinus.

Development, application and validation of a Taqman real-time RT-PCR assay for the detection of infectious salmon anaemia virus (ISAV) in Atlantic salmon (Salmo salar)

Infectious salmon anaemia (ISA) is a disease of cultured Atlantic salmon (Salmo salar) which was successfully eradicated from Scotland following its emergence in 1998. The rapid deployment of sensitive diagnostic methods for the detection of ISA virus (ISAV) was fundamental to the swift eradication of ISA disease in Scotland and continues to be of crucial importance to surveillance of the aquaculture industry. This study reports the development, validation, application and interpretation of two independent, highly sensitive and specific semi-quantitative Taqman real-time RT-PCR (qRT-PCR) methods for the detection of ISAV. Such technology offers considerable advantages over conventional RT-PCR methods in current routine use for ISAV surveillance. These include an increased sensitivity, enhanced specificity, semi-quantification using endogenous controls, a lack of subjectivity in results interpretation, speed of processing and improved contamination control.