Changes in adult neurogenesis in neurodegenerative diseases: cause or consequence?

This review addresses the role of adult hippocampal neurogenesis and stem cells in some of the most common neurodegenerative disorders and their related animal models. We discuss recent literature in relation to Alzheimer's disease and dementia, Parkinson's disease, Huntington's disease, amyotrophic lateral sclerosis, alcoholism, ischemia, epilepsy and major depression.

Relating functional changes during hand movement to clinical parameters in patients with multiple sclerosis in a multi-centre fMRI study

We performed a prospective multi-centre study using functional magnetic resonance imaging (fMRI) to better characterize the relationships between clinical expression and brain function in patients with multiple sclerosis (MS) at eight European sites (56 MS patients and 60 age-matched, healthy controls). Patients showed greater task-related activation bilaterally in brain regions including the pre- and post-central, inferior and superior frontal, cingulate and superior temporal gyri and insula (P < 0.05, all statistics corrected for multiple comparisons). Both patients and healthy controls showed greater brain activation with increasing age in the ipsilateral pre-central and inferior frontal gyri (P < 0.05). Patients, but not controls, showed greater brain activation in the anterior cingulate gyrus and the bilateral ventral striatum (P < 0.05) with less hand dexterity. An interaction between functional activation changes in MS and age was found. This large fMRI study over a broadly selected MS patient population confirms that movement for patients demands significantly greater cognitive 'resource allocation' and suggests age-related differences in brain responses to the disease. These observations add to evidence that brain functional responses (including potentially adaptive brain plasticity) contribute to modulation of clinical expression of MS pathology and demonstrate the feasibility of a multi-site functional MRI study of MS.

Genetic Polymorphism of CYP2C19 gene in the Stanislas cohort. A link with inflammation

CYP2C19, a member of the cytochrome P450 family, metabolises arachidonic acid to produce epoxyeicosanoid acids, which are involved in vascular tone and inflammation. Thus, this study describes the possible relationship between a CYP2C19 polymorphism (681G>A) and three inflammatory markers: interleukin (IL)-6, tumor necrosis factor-alpha (TNF-alpha) and high sensitivity C-reactive protein (hs-CRP) in healthy individuals. In a sub-sample of 178 men and 181 women from the Stanislas study, we quantified plasma IL-6 and TNF-alpha concentrations by using an enzyme-linked immunosorbent assay, and serum hs-CRP concentration by immunonephelometry. The CYP2C19 681G>A polymorphism was genotyped using the kinetic thermocycling allele specific PCR method. In the Stanislas cohort, the frequency of the allele CYP2C19*2 (681A) was 17.8%. Circulating levels of inflammatory factors were increased in individuals homozygous for the defective allele CYP2C19*2 (A) notably IL-6 in the whole sample (P= 0.0008) and hs-CRP only in women (P= 0.008), with a significant interaction with sex (P= 0.005), in comparison to carriers of one copy or more of the wild type allele CYP2C19*1 (G). Only a trend of association (P= 0.089) was found between this polymorphism and TNF-alpha concentration in the whole sample. The association between CYP2C19*2 polymorphism and inflammatory markers' concentrations could suggest that CYP2C19 may be considered as a new candidate gene for cardiovascular risks via inflammation.

During infection of epithelial cells Salmonella enterica serovar Typhimurium undergoes a time-dependent transcriptional adaptation that results in simultaneous expression of three type 3 secretion systems

The biogenesis of the Salmonella-containing vacuole within mammalian cells has been intensively studied over recent years. However, the ability of Salmonella to sense and adapt to the intracellular environment of different types of host cells has received much less attention. To address this issue, we report the transcriptome of Salmonella enterica serovar Typhimurium SL1344 within epithelial cells and show comparisons with Salmonella gene expression inside macrophages. We report that S. Typhimurium expresses a characteristic intracellular transcriptomic signature in response to the environments it encounters within different cell types. The signature involves the upregulation of the mgtBC, pstACS and iro genes for magnesium, phosphate and iron uptake, and Salmonella pathogenicity island 2 (SPI2). Surprisingly, in addition to SPI2, the invasion-associated SPI1 pathogenicity island and the genes involved in flagellar biosynthesis were expressed inside epithelial cells at later stages of the infection, while they were constantly downregulated in macrophage-like cells. To our knowledge, this is the first report of the simultaneous transcription of all three Type Three Secretion Systems (T3SS) within an intracellular Salmonella population. We discovered that S. Typhimurium strain SL1344 was strongly cytotoxic to epithelial cells after 6 h of infection and hypothesize that the time-dependent changes in Salmonella gene expression within epithelial cells reflects the bacterial response to host cells that have been injured by the infection process.

The Emerging Risk Factors Collaboration: analysis of individual data on lipid, inflammatory and other markers in over 1.1 million participants in 104 prospective studies of cardiovascular diseases

Many long-term prospective studies have reported on associations of cardiovascular diseases with circulating lipid markers and/or inflammatory markers. Studies have not, however, generally been designed to provide reliable estimates under different circumstances and to correct for within-person variability. The Emerging Risk Factors Collaboration has established a central database on over 1.1 million participants from 104 prospective population-based studies, in which subsets have information on lipid and inflammatory markers, other characteristics, as well as major cardiovascular morbidity and cause-specific mortality. Information on repeat measurements on relevant characteristics has been collected in approximately 340,000 participants to enable estimation of and correction for within-person variability. Re-analysis of individual data will yield up to approximately 69,000 incident fatal or nonfatal first ever major cardiovascular outcomes recorded during about 11.7 million person years at risk. The primary analyses will involve age-specific regression models in people without known baseline cardiovascular disease in relation to fatal or nonfatal first ever coronary heart disease outcomes. This initiative will characterize more precisely and in greater detail than has previously been possible the shape and strength of the age- and sex-specific associations of several lipid and inflammatory markers with incident coronary heart disease outcomes (and, secondarily, with other incident cardiovascular outcomes) under a wide range of circumstances. It will, therefore, help to determine to what extent such associations are independent from possible confounding factors and to what extent such markers (separately and in combination) provide incremental predictive value.

The clinical relevance of p53 isoforms modifying the effects of p53 mutation on survival from breast cancer

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Background: p53 is a key gene in the development of breast cancer and response to therapy. Nine splice variants of p53 in breast cancer have been identified, with full length p53, p53beta and p53gamma (both 46kD, C terminal truncated proteins) commonly expressed. This study examined the clinical relevance of splice variants in breast cancer. Methods: Tumors from 248 patients with primary breast cancer were examined for mutation with the Roche p53 mutation chip and p53 isoform expression detected by RT-PCR followed by nested PCR; full clinical and pathological data included median follow up of 6.4 years. Results: p53 mutation, identified in 65/248 (26%) cancers, was significantly associated by Chi square test with shorter survival (p=0.001), histological grade 3 (p<0.001) and estrogen receptor (ER) negative cancers (p<0.001), as expected. Expression of p53 beta or p53 gamma mRNA was associated with p53 mutation (p=0.002, Fisher's exact test). Intriguingly, the patient groups with a mutant p53 cancer but expressing p53 gamma or p53 beta or both isoforms had survival curves comparable to patients with cancer containing wild type p53. Similarly, p53 gamma or p53 beta was associated with ER negative cancers (Chi square; p<0.001), but the group of ER negative tumors expressing p53 gamma or p53 beta had improved survival similar to ER positive cancers. Patients with p53 mutant, p53 beta negative and ER negative cancers comprised half of those who died within 3 years of diagnosis. Conclusions: p53 beta or p53 gamma isoform expression in breast cancer is associated with better prognosis and may moderate disease behaviour even in mutant p53 and ER negative cancers. Manipulation of p53 isoforms in breast cancer may thus offer therapeutic potential.

No significant financial relationships to disclose.

Evaluation of methods to identify the Klebsiella pneumoniae carbapenemase in Enterobacteriaceae

The Klebsiella pneumoniae carbapenem (KPC) beta-lactamase occurs in Enterobacteriaceae and can confer resistance to all beta-lactam agents including carbapenems. The enzyme may confer low-level carbapenem resistance, and the failure of susceptibility methods to identify this resistance has been reported. Automated and nonautomated methods for carbapenem susceptibility were evaluated for identification of KPC-mediated resistance. Ertapenem was a more sensitive indicator of KPC resistance than meropenem and imipenem independently of the method used. Carbapenemase production could be confirmed with the modified Hodge test.

The prognostic value of PSA derivatives in favourable risk localised prostate cancer

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Introduction: Risk stratification in localized prostate cancer is based on PSA level, Gleason score and T stage. PSA derivatives may be of additional prognostic value. We have assessed the use of PSA derivatives in the prediction of histologic disease progression on repeat biopsy in patients on active surveillance. Methods: In a prospective cohort study of active surveillance, men with untreated, low- and intermediate-risk, clinically localized prostate cancer (T1/2a, PSA < 15 ng/ml, Gleason score ≤ 3 + 4, and % positive cores ≤ 50%) had repeat octant prostate biopsies 18–24 months after diagnosis. Histologic progression was defined as primary Gleason pattern ≥ 4, or % positive cores > 50 %, or an increase in Gleason score from ≤ 6 to ≥ 7. Standard clinical variables and PSA derivatives were analysed with respect to histologic progression. Multivariate analysis was performed including all standard variables both with each PSA derivative individually, and with all PSA derivatives. Results: 175 men had repeat biopsy. Median age was 67 yrs and median initial PSA, 6.5 ng/ml. Histologic disease progression was seen in 50 (29%) cases. Factors associated with histologic progression on univariate analysis were PSA velocity (p=0.0001), PSA density (p=0.0002), free-total PSA ratio (p=0.002), maximal % core involvement (p=0.009), age (p=0.003), and initial PSA level (p=0.02). On multivariate analysis, each PSA derivative was significant, independent of standard clinical variables. On combined multivariate analysis, free-total PSA ratio (p=0.0027), PSA velocity (p=0.009), age (p=0.0057) and maximal % core involvement (p=0.011) were significant determinants of histologic progression. Conclusions: Free-total PSA ratio and PSA velocity may be useful in the subclassification of favourable-risk localized disease. Larger validation studies in active surveillance patients are warranted.

No significant financial relationships to disclose.

A feasibility study of using gold seeds as fiducial markers for bladder localization during radical radiotherapy

Target localization and verification of the treatment position is important for the accurate delivery of conformal radiotherapy. The bladder in particular is a deformable structure whose shape and position continually varies throughout a course of radiation treatment as a result of bladder filling. We report a novel technique of organ localization using gold seeds as fiducial markers that are implanted into the bladder using a specially adapted applicator that is passed through a rigid cystoscope. The seeds are readily apparent on electronic portal imaging taken at the time of radiotherapy and can thus act as a surrogate for bladder position. The feasibility and technical aspects of performing such a procedure on eight patients were assessed. In all of the patients, some of the seeds were visible on the planning CT scan and remained within the bladder wall throughout the course of radiotherapy treatment. The drop-out rate was minimized by the use of cystodiathermy at the site of seed insertion. It was possible to place the seeds in both areas of normal and diseased bladder tissue. The procedure was associated with minimal toxicity. This technique will form the basis for planning further studies on bladder localization.

Prairie and turf buffer strips for controlling runoff from paved surfaces

Eutrophication of surface waters due to nonpoint source pollution from urban environments has raised awareness of the need to decrease runoff from roads and other impervious surfaces. These concerns have led to precautionary P application restrictions on turf and requirements for vegetative buffer strips. The impacts of two plant communities and three impervious/pervious surface ratios were assessed on runoff water quality and quantity. A mixed forb/grass prairie and a Kentucky bluegrass (Poa pratensis L.) blend were seeded and runoff was monitored and analyzed for total volume, total P, soluble P, soluble organic P, bioavailable P, total suspended solids, and total organic suspended solids. Mean annual runoff volumes, all types of mean annual P nutrient losses, and sediment loads were not significantly affected by treatments because over 80% of runoff occurred during frozen soil conditions. Total P losses from prairie and turf were similar, averaging 1.96 and 2.12 kg ha(-1) yr(-1), respectively. Vegetation appeared to be a likely contributor of nutrients, particularly from prairie during winter dormancy. When runoff occurred during non-frozen soil conditions turf allowed significantly (P < or = 0.10) lower runoff volumes compared with prairie vegetation and the 1:2 and 1:4 impervious/pervious surface ratios had less runoff than the 1:1 ratio (P < or = 0.05). In climates where the majority of runoff occurs during frozen ground conditions, vegetative buffers strips alone are unlikely to dramatically reduce runoff and nutrient loading into surface waters. Regardless of vegetation type or size, natural nutrient biogeochemical cycling will cause nutrient loss in surface runoff waters, and these values may represent baseline thresholds below which values cannot be obtained.

Vasopressin administration facilitates fluid removal during hemodialysis

Inadequate secretion of vasopressin during fluid removal by hemodialysis may contribute to the cardiovascular instability that complicates this therapy and administration of exogenous hormone, by supporting arterial pressure, may facilitate volume removal. To test this, we measured plasma vasopressin in patients with end-stage renal disease (ESRD) during hemodialysis and found that despite significant fluid removal, plasma vasopressin concentration did not increase. We further found that ESRD did not alter the endogenous removal rate of plasma vasopressin and that plasma hormone is not dialyzed. Finally, in a randomized, double-blinded, placebo-controlled trial in 22 hypertensive patients, we examined the effect of a constant infusion of a non-pressor dose of vasopressin on the arterial pressure response during a hemodialysis in which the target fluid loss was increased by 0.5 kg over the baseline prescription. We found that arterial pressure was more stable in the patients receiving vasopressin and that while only one patient (9%) in the vasopressin group had a symptomatic hypotensive episode, 64% of the patients receiving placebo had such an episode (P=0.024). Moreover, increased fluid removal was achieved only in the vasopressin group (520+/-90 ml vs 64+/-130 ml, P=0.01). Thus, administration of non-pressor doses of vasopressin to hypertensive subjects improves cardiovascular stability during hemodialysis and allows increased removal of excess extracellular fluid. Inadequate vasopressin secretion during hemodialysis-induced fluid removal is a likely contributor to the intradialytic hypotension that limits fluid removal.