50 research outputs found

    Cryptosporidium Priming Is More Effective than Vaccine for Protection against Cryptosporidiosis in a Murine Protein Malnutrition Model

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    Cryptosporidium is a major cause of severe diarrhea, especially in malnourished children. Using a murine model of C. parvum oocyst challenge that recapitulates clinical features of severe cryptosporidiosis during malnutrition, we interrogated the effect of protein malnutrition (PM) on primary and secondary responses to C. parvum challenge, and tested the differential ability of mucosal priming strategies to overcome the PM-induced susceptibility. We determined that while PM fundamentally alters systemic and mucosal primary immune responses to Cryptosporidium, priming with C. parvum (106 oocysts) provides robust protective immunity against re-challenge despite ongoing PM. C. parvum priming restores mucosal Th1-type effectors (CD3+CD8+CD103+ T-cells) and cytokines (IFNγ, and IL12p40) that otherwise decrease with ongoing PM. Vaccination strategies with Cryptosporidium antigens expressed in the S. Typhi vector 908htr, however, do not enhance Th1-type responses to C. parvum challenge during PM, even though vaccination strongly boosts immunity in challenged fully nourished hosts. Remote non-specific exposures to the attenuated S. Typhi vector alone or the TLR9 agonist CpG ODN-1668 can partially attenuate C. parvum severity during PM, but neither as effectively as viable C. parvum priming. We conclude that although PM interferes with basal and vaccine-boosted immune responses to C. parvum, sustained reductions in disease severity are possible through mucosal activators of host defenses, and specifically C. parvum priming can elicit impressively robust Th1-type protective immunity despite ongoing protein malnutrition. These findings add insight into potential correlates of Cryptosporidium immunity and future vaccine strategies in malnourished children

    The Colorectal cancer disease-specific transcriptome may facilitate the discovery of more biologically and clinically relevant information

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    <p>Abstract</p> <p>Background</p> <p>To date, there are no clinically reliable predictive markers of response to the current treatment regimens for advanced colorectal cancer. The aim of the current study was to compare and assess the power of transcriptional profiling using a generic microarray and a disease-specific transcriptome-based microarray. We also examined the biological and clinical relevance of the disease-specific transcriptome.</p> <p>Methods</p> <p>DNA microarray profiling was carried out on isogenic sensitive and 5-FU-resistant HCT116 colorectal cancer cell lines using the Affymetrix HG-U133 Plus2.0 array and the Almac Diagnostics Colorectal cancer disease specific Research tool. In addition, DNA microarray profiling was also carried out on pre-treatment metastatic colorectal cancer biopsies using the colorectal cancer disease specific Research tool. The two microarray platforms were compared based on detection of probesets and biological information.</p> <p>Results</p> <p>The results demonstrated that the disease-specific transcriptome-based microarray was able to out-perform the generic genomic-based microarray on a number of levels including detection of transcripts and pathway analysis. In addition, the disease-specific microarray contains a high percentage of antisense transcripts and further analysis demonstrated that a number of these exist in sense:antisense pairs. Comparison between cell line models and metastatic CRC patient biopsies further demonstrated that a number of the identified sense:antisense pairs were also detected in CRC patient biopsies, suggesting potential clinical relevance.</p> <p>Conclusions</p> <p>Analysis from our <it>in vitro </it>and clinical experiments has demonstrated that many transcripts exist in sense:antisense pairs including <it>IGF2BP2</it>, which may have a direct regulatory function in the context of colorectal cancer. While the functional relevance of the antisense transcripts has been established by many studies, their functional role is currently unclear; however, the numbers that have been detected by the disease-specific microarray would suggest that they may be important regulatory transcripts. This study has demonstrated the power of a disease-specific transcriptome-based approach and highlighted the potential novel biologically and clinically relevant information that is gained when using such a methodology.</p

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    613 cases of splenic rupture without risk factors or previously diagnosed disease: a systematic review

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    Background Rupture of the spleen in the absence of trauma or previously diagnosed disease is largely ignored in the emergency literature and is often not documented as such in journals from other fields. We have conducted a systematic review of the literature to highlight the surprisingly frequent occurrence of this phenomenon and to document the diversity of diseases that can present in this fashion. Methods Systematic review of English and French language publications catalogued in Pubmed, Embase and CINAHL between 1950 and 2011. Results We found 613 cases of splenic rupture meeting the criteria above, 327 of which occurred as the presenting complaint of an underlying disease and 112 of which occurred following a medical procedure. Rupture appeared to occur spontaneously in histologically normal (but not necessarily normal size) spleens in 35 cases and after minor trauma in 23 cases. Medications were implicated in 47 cases, a splenic or adjacent anatomical abnormality in 31 cases and pregnancy or its complications in 38 cases. The most common associated diseases were infectious (n = 143), haematologic (n = 84) and non-haematologic neoplasms (n = 48). Amyloidosis (n = 24), internal trauma such as cough or vomiting (n = 17) and rheumatologic diseases (n = 10) are less frequently reported. Colonoscopy (n = 87) was the procedure reported most frequently as a cause of rupture. The anatomic abnormalities associated with rupture include splenic cysts (n = 6), infarction (n = 6) and hamartomata (n = 5). Medications associated with rupture include anticoagulants (n = 21), thrombolytics (n = 13) and recombinant G-CSF (n = 10). Other causes or associations reported very infrequently include other endoscopy, pulmonary, cardiac or abdominal surgery, hysterectomy, peliosis, empyema, remote pancreato-renal transplant, thrombosed splenic vein, hemangiomata, pancreatic pseudocysts, splenic artery aneurysm, cholesterol embolism, splenic granuloma, congenital diaphragmatic hernia, rib exostosis, pancreatitis, Gaucher's disease, Wilson's disease, pheochromocytoma, afibrinogenemia and ruptured ectopic pregnancy. Conclusions Emergency physicians should be attuned to the fact that rupture of the spleen can occur in the absence of major trauma or previously diagnosed splenic disease. The occurrence of such a rupture is likely to be the manifesting complaint of an underlying disease. Furthermore, colonoscopy should be more widely documented as a cause of splenic rupture

    Internal Medicine Residents' Perceptions of Cross-Cultural Training: Barriers, Needs, and Educational Recommendations

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    BACKGROUND: Physicians increasingly face the challenge of managing clinical encounters with patients from a range of cultural backgrounds. Despite widespread interest in cross-cultural care, little is known about resident physicians' perceptions of what will best enable them to provide quality care to diverse patient populations. OBJECTIVES: To assess medicine residents' (1) perceptions of cross-cultural care, (2) barriers to care, and (3) training experiences and recommendations. DESIGN, SETTING, AND PATIENTS: Qualitative individual interviews were conducted with 26 third-year medicine residents at Massachusetts General Hospital in Boston (response rate = 87%). Interviews were recorded, transcribed, and analyzed. RESULTS: Despite significant interest in cross-cultural care, almost all of the residents reported very little training during residency. Most had gained cross-cultural skills through informal learning. A few were skeptical about formal training, and some expressed concern that it is impossible to understand every culture. Challenges to the delivery of cross-cultural care included managing patients with limited English proficiency, who involve family in critical decision making, and who have beliefs about disease that vary from the biomedical model. Residents cited many implications to these barriers, ranging from negatively impacting the patient-physician relationship to compromised care. Training recommendations included making changes to the educational climate and informal and formal training mechanisms. CONCLUSIONS: If cross-cultural education is to be successful, it must take into account residents' perspectives and be focused on overcoming residents' cited barriers. It is important to convey that cross-cultural education is a set of skills that can be taught and applied, in a time-efficient manner, rather than requiring an insurmountable knowledge base

    p16INK4a Gene Promoter Hypermethylation in Mucosa as a Prognostic Factor for Patients with Colorectal Cancer

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    Low gene expression of folylpolyglutamate synthase (FPGS) in colorectal mucosa correlates with low folate levels and poor survival of colorectal cancer (CRC) patients. Because gene-specific hypermethylation is affected by the folate level, the hypermethylation status in mucosa may also be linked to clinical outcome of CRC patients. The tumor suppressor gene p16INK4a (p16) regulates the cell cycle and angiogenic switch. In human neoplastic tissues, the main mechanism of p16 inactivation is promoter methylation. The aim of the study was to determine whether hypermethylation of the p16 promoter could be detected in mucosa of CRC patients (n = 181) and to analyze if hypermethylation was related to survival. The relation between p16 hypermethylation and expression of FPGS and two other folate-associated genes, reduced folate carrier 1 (RFC-1), and thymidylate synthase (TS), was analyzed (n = 63). The results showed that p16 was hypermethylated in 65 (36%) of the mucosa samples and that hypermethylation was age-related (P = 0.029). After adjustment for known risk factors, Cox regression analysis showed that Dukes’ A-C patients with p16 hypermethylation in mucosa had an increased risk of cancer-related death (hazard ratio = 2.9, P = 0.007) and shorter disease-free survival (hazard ratio = 2.5, P = 0.015) compared with patients with no p16 hypermethylation. RFC-1 and FPGS gene expression levels were significantly correlated in patients lacking p16 hypermethylation in mucosa (P = 0.0003), but not at all correlated in patients having hypermethylation in mucosa (P = 1.0). In conclusion, p16 hypermethylation in mucosa of CRC patients was identified as an independent prognostic parameter for cancer-specific survival as well as an independent predictor of DFS. The results suggest that there might be a connection between folate-associated gene expression and p16 methylation status
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