Modulation of Host-Microbe Metabolism by Cholera Toxin.

In order for successful fecal-oral transmission, enteric bacterial pathogens have to successfully compete with the intestinal microbiota and reach high concentrations during infection. Vibrio cholerae requires cholera toxin (CT) to cause diarrheal disease, which is thought to promote the fecal-oral transmission of the pathogen. Besides inducing diarrheal disease, the catalytic activity of CT also alters host intestinal metabolism, which promotes the growth of V. cholerae during infection through the acquisition of host-derived nutrients. Furthermore, recent studies have found that CT-induced disease activates a niche-specific suite of V. cholerae genes during infection, some of which may be important for fecal-oral transmission of the pathogen. Our group is currently exploring the concept that CT-induced disease promotes the fecal-oral transmission of V. cholerae by modulating both host and pathogen metabolism. Furthermore, the role of the intestinal microbiota in pathogen growth and transmission during toxin-induced disease merits further investigation. These studies open the door to investigating whether other bacterial toxins also enhance pathogen growth and transmission during infection, which may shed light on the design of novel therapeutics for intervention or prevention of diarrheal diseases.

Yeast derlin Dfm1 employs a chaperone-like function to resolve misfolded membrane protein stress.

Protein aggregates are a common feature of diseased and aged cells. Membrane proteins comprise a quarter of the proteome, and yet, it is not well understood how aggregation of membrane proteins is regulated and what effects these aggregates can have on cellular health. We have determined in yeast that the derlin Dfm1 has a chaperone-like activity that influences misfolded membrane protein aggregation. We establish that this function of Dfm1 does not require recruitment of the ATPase Cdc48 and it is distinct from Dfm1's previously identified function in dislocating misfolded membrane proteins from the endoplasmic reticulum (ER) to the cytosol for degradation. Additionally, we assess the cellular impacts of misfolded membrane proteins in the absence of Dfm1 and determine that misfolded membrane proteins are toxic to cells in the absence of Dfm1 and cause disruptions to proteasomal and ubiquitin homeostasis.

Evaluation of sample stability for a quantitative faecal immunochemical test and comparison of two sample collection approaches.

Background Faecal immunochemical testing is increasingly being used to triage symptomatic patients for suspected colorectal cancer. However, there are limited data on the effect of preanalytical factors on faecal haemoglobin when measured by faecal immunochemical testing. The aim of this work was to evaluate the stability of faecal haemoglobin in faeces and to compare two methods of faecal haemoglobin sampling for faecal immunochemical testing. Methods Six patients provided faeces for faecal haemoglobin measurement which were transferred into specialized collection devices at baseline and at 1, 2, 3 and 7 days after storage at either room temperature or 4°C. A total of 137 patients returned both faeces transferred into the specialized collection device and faeces in a standard collection pot. A quantitative immunoturbidometric method was used to measure faecal haemoglobin and results were compared categorically. Discrepant results were assessed against diagnosis. Results Faecal haemoglobin concentration declined rapidly within a day of storage at room temperature but results remained ≥10 µg Hb/g faeces in 5/6 patients after two days. A faecal haemoglobin result ≥10 µg Hb/g faeces was obtained in 4/6 patients after storage for seven days at 4°C. Results obtained when patients used specialized collection devices were significantly different from results obtained when faeces was transferred into the specialized collection device in the laboratory. Conclusion There is considerable heterogeneity in the sample stability of faecal haemoglobin; therefore, samples should be transferred rapidly into specialized collection devices to prevent false-negative results. Use of collection devices by patients can lead to false-positive results compared with their use in a laboratory.

Can we use influencing factors to predict aspiration pneumonia in the United Kingdom?

BACKGROUND: The current study builds upon the work of others in looking at influencing factors of aspiration pneumonia in people with a swallowing problem. This study differs from previous researches on this topic, focusing on the United Kingdom (UK) population and involving more recently defined influencing factors of aspiration pneumonia. The study aims to explore the multifactorial nature of aspiration pneumonia in a UKdysphagic client group, as well as different disease specific variables. METHODS: Speech and Language Therapists collected data on 33 influencing factors over a period of 6 months during routine bedside swallowing assessment of 687 patients. All subjects were adults referred with suspected dysphagia and included acute inpatients, head and neck cancer patients and adults with learning disabilities. The study population included 400 males and 287 females and ages ranged from 17 to 102 giving a mean age of 72.9 years. The influence of the different variables included in the study was evaluated using multivariate logistic regression analysis. RESULTS: The results show that 13 statistically significant influencing factors were implicated in the development of aspiration pneumonia for this group. Out of these, nine correlate with the previous work undertaken in the United States. These were poor mobility, nil by mouth status, age, dependency for feeding, number of medications, Chronic Obstructive Pulmonary Disease (COPD), number of medical conditions, stroke and alcohol abuse. Four further influencing factors were shown to be significant in the UK population, these were dysphagia, only oral intake, bedfast, and male gender. CONCLUSIONS: This study confirms that in the UK there are influencing factors in the development of an aspiration pneumonia. It would be prudent to remember that a direct link is yet to be established when applying this knowledge to inform clinical management.

Preclinical development of hybrid cell vaccines for multiple myeloma.

Immunotherapy may provide alternative or supplementary treatment of multiple myeloma (MM). We propose that hybrid cells, formed by fusing professional antigen-presenting cells with malignant plasma cells, would induce immune responses capable of mediating tumour regression. The human B-lymphoblastoid cell line, HMy2, was fused in vitro with CD138+ bead-separated myeloma plasma cells from five patients with MM. The hybrid cell lines generated in these studies grew stably in tissue culture, and maintained their phenotypic and functional characteristics, providing self-renewing cell lines with potential for therapeutic vaccination. The hybrid cells stimulated allogeneic and autologous T-cell proliferative responses in vitro to a considerably greater degree than their respective parent myeloma plasma cells, and directly activated both CD4+ and CD8+ T-cell responses. The enhanced T-cell stimulation correlated with expression of CD80 on the hybrid cells, and was inhibited by CTLA4-Ig fusion protein. The hybrid cell lines expressed several tumour-associated antigens known to be expressed in myeloma. These data show that self-replicating cell lines with enhanced immunostimulatory properties and potential for therapeutic vaccination can be generated by in vitro fusion of ex vivo myeloma cells and B-lymphoblastoid cell lines.

The experiences of teenagers and young adults with cancer--results of 2004 conference survey.

In 2004, 350 teenagers and young adults (TYAs) attended the third Find Your Sense of Tumour Conference for cancer patients. This provided a unique opportunity to survey a large group of patients regarding their cancer experience. Analysis of the results showed that delegates had both positive and negative experiences of the cancer journey and had clear views regarding service provision. The survey showed that the majority of TYAs with or who have had cancer would like to be treated on a specialist unit. There are currently 7 Teenage and Young Adult Units developed by Teenage Cancer Trust within the UK; however, a large number of patients do not have access to these specialist services. Despite the increased attention to TYA health needs there are still a number of issues relating to cancer services that need addressing as a matter of urgency in order to ensure that future patients receive a timely diagnosis, together with appropriate care that meets the specific needs of this unique client group.

Evidence for reduced B-cell progenitors in early (low-risk) myelodysplastic syndrome.

Early, low-risk International Prognostic Scoring System (IPSS) myelodysplastic syndrome (MDS) is a heterogeneous disorder where the molecular and cellular hematopoietic defects are poorly understood. To gain insight into this condition, we analyzed gene expression profiles of marrow CD34+ progenitor cells from normal-karyotype, low-blast-count MDS patients, age-matched controls, and patients with non-MDS anemia. Given the heterogeneity of early MDS, a surprisingly consistent finding was decreased expression of B-cell lineage-affiliated genes in MDS patients compared with healthy controls and 3 of 5 samples with non-MDS anemia. Both patients with non-MDS anemia with reduced B-cell gene expression were on chemotherapy. In 25 of 27 of the original samples and 9 further MDS samples, Taqman real-time polymerase chain reaction (PCR) confirmed these data. Flow cytometry on unfractionated marrow from independent samples also demonstrated reduced B-cell progenitors in MDS patients compared with healthy controls. These novel findings suggest a common perturbation in early MDS hematopoiesis. They also provide the rationale for a larger study to evaluate the diagnostic utility of reduced B-cell progenitor number as a diagnostic biomarker of early low-risk MDS, which can pose a diagnostic challenge.

Diagnosis and monitoring a case of light-chain deposition disease in the kidney using a new, sensitive immunoassay.

A 59-year-old male was diagnosed with nephrotic syndrome secondary to light-chain deposition disease. There was no other evidence of a B cell clonal disorder or amyloidosis; circulating free light chains were identified using a new immunoassay (Freelite) and used to monitor disease progression. Improvement in renal function and proteinuria following VAMP chemotherapy correlated with a reduction in circulating light-chain levels. This case demonstrates a new tool in monitoring light-chain deposition disease in the kidney.

Randomized comparison of low-dose versus high-dose interferon-alfa in chronic myeloid leukemia: prospective collaboration of 3 joint trials by the MRC and HOVON groups.

The optimal dose of interferon-alfa (IFN) for chronic myeloid leukemia (CML) is unknown. Retrospective analyses suggest that low doses are as effective as high doses, with less toxicity and fewer patients abandoning the drug. The Dutch Hemato-Oncology Association (HOVON) and British Medical Research Council (MRC) cooperative groups jointly performed randomized trials in newly diagnosed CML patients, comparing high-dose IFN (5 MIU/m(2) daily) with low-dose (3 MIU, 5 times a week). Both arms allowed additional hydroxyurea to keep the white blood cell count lower than 5 x 10(9)/L. Quality of life data were collected in a subset of patients. Between 1993 and 2001, 407 patients were randomized. At a median follow-up of 53 months, there were no significant differences in overall survival (odds ratio = 1.09, 95% confidence interval, 0.81-1.46), progression-free survival, and complete hematologic or major cytogenetic responses. Fewer patients in the low-dose group abandoned IFN for reasons other than transplant or progressive disease (P =.002, 58% vs 72% at 5 years). Quality of life data showed comparable results in both arms for most factors. There is no evidence of benefit for high-dose IFN compared with low-dose for the treatment of CML. Therefore, when IFN is combined with other drugs, low-dose IFN is advised, to minimize toxicity and costs.

Cognitive outcome of long-term survivors of multisystem langerhans cell histiocytosis: a single-institution, cross-sectional study.

PURPOSE: Damage to the CNS, including the cerebellum, and to the hypothalamopituitary axis, is documented in Langerhans cell histiocytosis (LCH). Neuropsychologic deficits have been recognized, but this is the first study in which cognitive function has been systematically assessed in a cohort of patients. PATIENTS AND METHODS: Twenty-eight long-term survivors of multisystem LCH (mean age, 15.1 years) were investigated for intelligence, memory and learning, language, and academic attainments. RESULTS: The mean intelligence quotient (IQ) of the entire group was not significantly different from the mean of the population (ie, mean +/- SD, 100 +/- 1), but there were wide ranges (Full-Scale IQ [FSIQ]: mean, 93.6; range, 61.7 to 134; Performance IQ [PIQ]: mean, 92.2; range, 46 to 136; and Verbal IQ [VIQ]: mean, 93.7; range, 64.2 to 126). CNS involvement was a significant risk factor for lower scores, but sex, diabetes insipidus, and cranial radiotherapy were not. The CNS group had lower VIQ, PIQ, and FSIQ than patients with no CNS involvement (no CNS group: mean +/- SD FSIQ, 102.3 +/- 15.6; CNS group: mean +/- SD FSIQ, 73.6 +/- 7.7; P <.001). A similar pattern of results was obtained for all other cognitive measures. Even when effects of reduction in FSIQ were taken into account, specific deficits were found in patients in the CNS group. CONCLUSION: Long-term survivors of multisystem LCH, particularly patients with CNS involvement, may develop significant cognitive deficits. All patients should have formal, repeated neuropsychologic assessment as part of long-term follow-up, which will enable abnormalities to be detected early so that appropriate supportive measures can be offered.