An observational study on the expression levels of MDM2 and MDMX proteins, and associated effects on P53 in a series of human liposarcomas

Background

Inactivation of wild type P53 by its main cellular inhibitors (MDM2 and MDMX) is a well recognised feature of tumour formation in liposarcomas. MDM2 over-expression has been detected in approximately 80% of liposarcomas but only limited information is available about MDMX over-expression. To date, we are not aware of any study that has described the patterns of MDM2 and MDMX co-expression in liposarcomas. Such information has become more pertinent as various novel MDM2 and/or MDMX single and dual affinity antagonist compounds are emerging as an alternative approach for potential targeted therapeutic strategies.

Methods

We analysed a case series of 61 fully characterized liposarcomas of various sub-types by immunohistochemistry, to assess the expression levels of P53, MDM2 and MDMX, simultaneously. P53 sequencing was performed in all cases that expressed P53 protein in 10% or more of cells to rule out mutation-related over-expression.

Results

50 cases over-expressed MDM2 and 42 of these co-expressed MDMX at varying relative levels. The relative expression levels of the two proteins with respect to each other were subtype-dependent. This apparently affected the detected levels of P53 directly in two distinct patterns. Diminished levels of P53 were observed when MDM2 was significantly higher in relation to MDMX, suggesting a dominant role for MDM2 in the degradation of P53. Higher levels of P53 were noted with increasing MDMX levels suggesting an interaction between MDM2 and MDMX that resulted in a reduced efficiency of MDM2 in degrading P53. Of the 26 cases of liposarcoma with elevated P53 expression, 5 were found to have a somatic mutation in the P53 gene.

Conclusions

The results suggest that complex dynamic interactions between MDM2 and MDMX proteins may directly affect the cellular levels of P53. This therefore suggests that careful characterization of both these markers will be necessary in tumours when considering in vivo evaluation of novel blocker compounds for MDM proteins, as a therapeutic strategy to restore wild type P53 function.

Oral arginine metabolism may decrease the risk for dental caries in children

Arginine metabolism by oral bacteria via the arginine deiminase system (ADS) increases the local pH, which can neutralize the effects of acidification from sugar metabolism and reduce the cariogenicity of oral biofilms. To explore the relationship between oral arginine metabolism and dental caries experience in children, we measured ADS activity in oral samples from 100 children and correlated it with their caries status and type of dentition. Supragingival dental plaque was collected from tooth surfaces that were caries-lesion-free (PF) and from dentinal (PD) and enamel (PE) caries lesions. Regardless of children's caries status or type of dentition, PF (378.6) had significantly higher ADS activity compared with PD (208.4; p < .001) and PE (194.8; p = .005). There was no significant difference in the salivary arginolytic activity among children with different caries status. Mixed-model analysis showed that plaque caries status is significantly associated with ADS activity despite children's age, caries status, and dentition (p < .001), with healthy plaque predicting higher ADS activity compared with diseased plaque. Plaque arginine metabolism varies greatly among children and tooth sites, which may affect their susceptibility to caries.

Chronic fatigue syndrome in the UK armed forces

Chronic Fatigue Syndrome (CFS) is a debilitating condition that can have a significant impact on the lives of patients and those who care for them. In the UK Armed Forces this condition can also have a marked impact on a patient's career and their ability to function in the deployed environment. In this article the recognition and management of CFS will be discussed, as well as the occupational considerations within the UK Armed Forces.

Epigenetic regulation of olfactory receptor gene expression by the Myb-MuvB/dREAM complex

In both mammals and insects, an olfactory neuron will usually select a single olfactory receptor and repress remaining members of large receptor families. Here we show that a conserved multiprotein complex, Myb-MuvB (MMB)/dREAM, plays an important role in mediating neuron-specific expression of the carbon dioxide (CO(2)) receptor genes (Gr63a/Gr21a) in Drosophila. Activity of Myb in the complex is required for expression of Gr63a/Gr21a and acts in opposition to the histone methyltransferase Su(var)3-9. Consistent with this, we observed repressive dimethylated H3K9 modifications at the receptor gene loci, suggesting a mechanism for silencing receptor gene expression. Conversely, other complex members, Mip120 (Myb-interacting protein 120) and E2F2, are required for repression of Gr63a in inappropriate neurons. Misexpression in mutants is accompanied by an increase in the H3K4me3 mark of active chromatin at the receptor gene locus. Nuclei of CO(2) receptor-expressing neurons contain reduced levels of the repressive subunit Mip120 compared with surrounding neurons and increased levels of Myb, suggesting that activity of the complex can be regulated in a cell-specific manner. Our evidence suggests a model in which olfactory receptors are regulated epigenetically and the MMB/dREAM complex plays a critical role in specifying, maintaining, and modulating the receptor-to-neuron map.

The impact of mucosal infections on acquisition and progression of tuberculosis

More than one-third of the world's population, or over 2 billion people, are infected with Mycobacterium tuberculosis, the causative pathogen of tuberculosis in humans. Why only 10% of those infected develop active disease while the remainder harbor latent infection remains one of the greatest scientific and public health mysteries. Bacterial persistence is characterized by a dynamic state of immunological tolerance between pathogen and host. The critical role of CD4(+) T cells in defense against intracellular pathogens became evident during epidemiological studies of HIV-1 infection, which showed a clear inverse relationship between CD4(+) T-cell count in peripheral blood and increased risk of infection with M. tuberculosis, pneumocystis and Toxoplasma gondii. There is also growing evidence of a common mucosal immune system, whereby immune cells activated at one mucosal site may disseminate to remote effector sites. In this commentary, we review emerging evidence from human studies that the outcome of M. tuberculosis infection is influenced by concurrent mucosal infections, using Helicobacter pylori and geohelminths as examples. Understanding how the complexity of microbial exposures influences host immunity may have important implications for vaccine development and therapeutic interventions.

An investigation of the relationship between anxiety and depression and urge incontinence in women: Development of a psychological model

OBJECTIVES

The study investigated the association between anxiety and depression and urge incontinence and the direction of causal pathways between these variables.

DESIGN

A prospective longitudinal postal survey.

METHOD

A random sample of women aged 40 years or more, registered with a general practitioner in Leicestershire or Rutland, was mailed a postal questionnaire. The questionnaire included questions on general health, urinary symptoms and the Hospital Anxiety and Depression Scale (HADS). In total, 12,568 women responded to the baseline postal survey (65.3% response rate) and 9,596 to the first annual follow-up (79.8% response rate). The prevalence and one-year incident rates of these symptoms were compared and contrasted, whilst controlling for confounding variables.

RESULTS

A significant proportion of women with urge incontinence reported symptoms of anxiety (56.6%) and depression (37.6%). Anxiety and depression were associated with a number of urinary symptoms and were not exclusive to urge incontinence. Incident cases of anxiety and depression were predicted by the presence of urge incontinence at baseline. Incident cases of urge incontinence were predicted by anxiety at baseline, but not depression. Anxiety, urge incontinence and frequency appeared to interact and exacerbate each other.

CONCLUSIONS

The findings demonstrated the relevance of emotional factors in the development and maintenance of urge incontinence. Currently, assessment and treatment protocols for urge incontinence concentrate on physical symptoms and toilet behaviours. A more integrated psychological model of urge incontinence is proposed.

Pattern of release and relationship between HMGB-1 and IL-6 following blunt trauma

BACKGROUND

High mobility group box-1 (HMGB-1), a recently identified inflammatory cytokine, is implicated in the pathogenesis of several inflammatory, infective and neoplastic processes. Patterns of expression following blunt trauma have not been adequately reported in the literature. This study aimed to quantify the serum concentrations of HMGB-1 following blunt trauma, and assess its relationship with the more established interleukin 6 (IL-6).

PATIENTS AND METHODS

20 patients with median injury severity score 17 (range 9-36) sustaining closed diaphyseal fractures of the femur treated by intramedullary nailing were included in the study. Serum concentrations of HMGB-1 and IL-6 were measured at several time points during their treatment.

RESULTS

A strong correlation was observed between admission and day 1 post-op concentrations of IL-6 and both the injury severity score (ISS) and the requirement for intensive care unit treatment. Serum concentrations of HMGB-1 did not demonstrate such a correlation. Around day 3 when IL-6 concentrations begin to fall, serum HMGB-1 concentrations were observed to increase.

CONCLUSIONS

IL-6 concentration measured early after admission is again shown to be strongly associated with overall injury severity and requirement for intensive care unit treatment. In contrast, HMGB-1 appears to be a late inflammatory mediator with levels becoming elevated once serum concentrations of IL-6 begin to fall. However, we were unable to demonstrate any relationship with injury severity or requirement for ICU care at any stage. These preliminary findings may form the basis for future research in this area.

The systemic inflammatory response following femoral canal reaming using the reamer-irrigator-aspirator (RIA) device

We evaluated the peripheral release of inflammatory mediators after femoral fracture and subsequent intramedullary reaming using the RIA reamers. IL-6 was elevated after trauma, and reaming with RIA induced a measurable second hit response. However, despite a higher ISS, the levels of IL-6 in the RIA group were similar to the levels measured in a group of patients where reaming of the femoral canal was performed using conventional reamers. There was one death related to fat embolism syndrome in the conventional reamers group. However, the overall incidence of complications was low and similar between the 2 groups of studied patients. In polytrauma patients, large scale studies are desirable to evaluate further the immuno-inflammatory response using the RIA reamers prior to the instrumentation of the femoral canal.

Psychological distress among male patients and male spouses: what do oncologists need to know?

BACKGROUND

The aim of the current study was to strengthen the knowledge of oncologists concerning psychological distress and social support among married and unmarried male cancer patients and healthy male spouses of female cancer patients.

PATIENTS AND METHODS

Three groups of men were recruited from three major cancer centers in Israel: 185 married colon and rectal cancer patients, 54 single (unmarried) colon and rectal cancer patients, and 153 male spouses of female cancer patients. Participants were evaluated on four standardized instruments measuring psychological distress, coping, and social support.

RESULTS

About 42.6% of the participants reported on a clinical level of psychological distress, with the highest rates (61.1%) among the single (unmarried) patients. Distress was negatively correlated to Karnofsky score and coping variables among all study groups. Distress was significantly and negatively correlated to social support variables among the spouses and married patients but not among the single patient groups.

CONCLUSIONS

Social support received by male cancer patients from friends and family may be mediated by spouse support. As a result, single male patients are at higher risk for psychological distress. Male spouses were also found to have high rates of distress. These two groups need special attention by oncologists.

Temozolomide (TMZ) and bevacizumab (BV) as initial treatment for unresectable or multifocal glioblastoma multiforme (GBM)

e13025

Background: GBMs are vascular tumors and inherently resistant to therapy. The prognosis for patients is poor with a median survival of 9–15 months. Patients with unresectable or multifocal GBMs have an even poorer prognosis, with a median survival of 6–8 months. Given the angiogenic phenotype of GBM, we conducted a phase II trial of upfront BV and 5-day TMZ in newly diagnosed unresectable or multifocal GBMs. Methods: Patients had histologically documented newly diagnosed GBMs that were unresectable or multifocal. Patients received up to 4 cycles of temozolomide at 200 mg/m2/d days 1–5 and BV at 10 mg/kg on days 1 and 14 in a 28 day cycle. An MRI was performed after every cycle and patients continued on therapy as long as there was no tumor progression, grade 4 non-hematologic toxicity or recurrent grade 4 hematologic toxicity after a dose reduction to 150 mg/m2/d. The primary endpoint was tumor response using the modified MacDonald criteria plus FLAIR and T2 sequences to evaluate non-enhancing tumor. Results were evaluated by two independent reviewers. Results: 41 patients were enrolled between October 2007 and September 2008 and 31 patients were analyzed after completion of cycle 2. As the best response, there were 8 (25.8%) partial responses, 19 (61.3 %) patients with stable disease, and 4(12.9 %) had disease progression. 19 of the 41 patients enrolled completed four cycles without tumor progression. The regimen was tolerable, with 3 grade 4 hematologic toxicities including neutropenia and thrombocytopenia. There were 2 grade 4 non-hematologic toxicities, including pulmonary embolism. There were two CNS hemorrhages. The median PFS was 3.6 months (2.9 months, 4.4 months) and the median OS was 4.5 months (3.7 months, 5.3 months). Conclusions: Upfront temozolomide and bevacizumab was well tolerated, but synergistic chemotherapy or growth factor inhibitors need to be added to produce meaningful clinical benefit, particularly for unresectable or multifocal GBM.

No significant financial relationships to disclose.

Cognitive development in macaques: Attentional set-shifting in juvenile and adult rhesus monkeys

In humans and nonhuman primates, the structure and function of frontal cortical regions of the brain are not completely developed until early adulthood. How this cortical development affects cognitive function continues to be elucidated. To that end, this experiment tested the ability of juvenile and adult rhesus monkeys to perform a cognitive task that is dependent upon intact frontal cortical function for optimal performance. Twenty-four juvenile (mean age 2.3 years) and 16 adult (mean age 10.3 years) rhesus monkeys were tested on the Cambridge Neuropsychological Test Automated Battery intradimensional/extradimensional set-shifting (ID/ED) task. Performance on the ID/ED task has been shown to be dependent upon frontal cortical function in both humans and nonhuman primates. Compared with adults, juveniles were impaired on the reversal of simple discrimination, intradimensional shift, reversal of intradimensional shift, and the extradimensional shift stages of the task. These results indicate juveniles committed more perseverative errors and more errors on the set-formation and set-shifting components of the ID/ED task. The developmental stage of the juvenile monkeys corresponds to roughly 5 to 6-year-old children, and these results are consistent with performance of human children and adults on similar ID/ED tests and on several other tests of attentional set-shifting or attentional flexibility. Furthermore, these results are consistent with the ongoing development of frontal cortical structures relating to ongoing cognitive development in nonhuman primates.

Growth factor release following femoral nailing

The aim of this study was to investigate whether growth factors essential for fracture healing are substantially increased in the immediate aftermath following reaming of the intramedullary cavity for stabilisation of femoral shaft fractures. Consecutive adult patients whose femoral shaft fractures stabilised with either reamed (10 patients) or unreamed (10 patients) intramedullary nailing were studied. Peripheral blood samples and samples from the femoral canal before and after reaming and nail insertion were collected. Serum was extracted and using Elisa colorimetric assays the concentration of Platelet Derived Growth Factor-BetaBeta (PDGF), Vascular Endothelial Growth Factor (VEGF), Insulin-like Growth Factor-I (IGF-I), Transforming Growth Factor beta 1 (TGF-beta1) and Bone Morphogenetic Protein-2 (BMP-2) was measured. The mean age of the twenty patients who participated in the study was 38 years (range 20-63). Reaming substantially increased all studied growth factors (p<0.05) locally in the femoral canal. VEGF and PDGF were increased after reaming by 111.2% and 115.6% respectively. IGF-I was increased by 31.5% and TGF-beta1 was increased by 54.2%. In the unreamed group the levels of PDGF-BB, VEGF, TGF-beta1 remained unchanged while the levels of IGF-I decreased by 10%. The levels of these mediators in the peripheral circulation were not altered irrespectively of the nail insertion technique used. BMP-2 levels during all time points were below the detection limit of the immunoassay. This study indicates that reaming of the intramedullary cavity is associated with increased liberation of growth factors. The osteogenic effect of reaming could be secondary not only to grafting debris but also to the increased liberation of these molecules.