A novel approach to evaluate the immunogenicity of viral antigens of clinical importance in HLA transgenic murine models

Transgenic (Tg) mice expressing HLA class I alleles and lacking murine MHC class I represent a useful model for the pre-clinical evaluation of human vaccines, which focus on induction of CD8(+) T-cell responses. We have developed a platform to be used in Tg mice for exploring the immunogenicity of T-cell targets, whose immunologic epitopes have yet to be defined. To test the attributes of the evaluation system in the context of an important human pathogen, we have explored multiple antigens from cytomegalovirus (CMV). A panel of recombinant modified vaccinia Ankara (MVA) vectors, expressing various CMV proteins (CMV-MVA) was used to immunize HLA-A*0201, B*0702 and A*1101 Tg mice. Immune splenocytes were in vitro stimulated (IVS) either using syngeneic lipo-polysaccharide activated lymphoblasts or Tg HLA-I matched human EBV-transformed B-lymphoblastoid cells (LCL), both loaded with peptide libraries, encompassing the CMV protein under investigation. IVS performed with peptide library loaded lymphoblasts failed to provide a reliable stimulation. In contrast, the usage of LCL as antigen presenting cells (APC) of CMV peptide libraries resulted in a consistent and specific amplification of the Tg T-cell response in animals immunized with CMV-MVAs. The LCL IVS method reliably allowed defining the immunogenicity and immunodominant CD8(+) T-cell regions of uncharacterized CMV antigens. The combination of CMV-MVA vectors, unbiased pools of CMV-specific peptide libraries presented by Tg HLA-I matched LCL constitutes a valid tool for the pre-clinical evaluation of model candidate vaccines. This convenient method could find application to investigate the immunogenicity profile of cancer antigens or proteins from infectious human pathogens.     

Isolated tuberculosis of the pancreas diagnosed with needle aspiration: a case report and review of the literature.

Pancreatic tuberculosis is very rare, especially in immunocompetent patients, and represents a diagnostic challenge. The clinical features in patients with pancreatic tuberculosis are usually non-specific. The radiological features mimic pancreatic malignancy or pancreatitis. We describe a case of pancreatic tuberculosis mimicking carcinoma on Computed tomography scan. Ultrasound guided fine needle aspiration cytology (FNAC) showed caseating granulomatous inflammation. The diagnosis of pancreatic tuberculosis was made and the patient was put on anti-tubercular therapy. Five months later, a repeat CT scan of the abdomen revealed resolution of the pancreatic lesion. We emphasize that tuberculosis should now be included in the differential diagnosis of a pancreatic mass. Diagnostic indicators include the association of a pancreatic mass with fever, the presence of abdominal pain and a cystic pancreatic mass in a younger patient coming from a region where tuberculosis is endemic.     

Pancreatic duct ascariasis: sonographic diagnosis--a case report.

We report the case of a 19-year old boy presenting in the emergency with severe epigastric pain whose biochemical tests revealed elevated serum amylase and lipase levels and a clinical diagnosis of acute pancreatitis was made. On ultrasonic examination, the pancreas appeared bulky with a linear tubular echogenic worm (ascaris) seen within the prominent main pancreatic duct. Successful removal of the pancreatic duct worm was achieved through endoscopic retrograde cholangio pancreatography (ERCP).     

A randomized double-blind placebo-controlled trial showing rifaximin to improve constipation by reducing methane production and accelerating colon transit: A pilot study

Objective

Gut microbe-derived methane may slow colon transit causing chronic constipation (CC). Effect of rifaximin on breath methane and slow-transit CC was evaluated.

Method

Bristol stool form, frequency, colon transit time (CTT), and breath methane were evaluated in 23 patients with CC (10 patients with constipation-predominant irritable bowel syndrome [IBS-C], 13 functional constipation, Rome III) and m-ethane production compared with 68 non-constipating IBS. Methane-producing CC (basal ≥?10 PPM and/or post-lactulose rise by >?10 PPM) was randomized (double-blind) to rifaximin (400-mg thrice/day, 2-weeks) or placebo. Stool forms, frequency, breath methane, and CTT were recorded afterward.

Results

CC patients tended to be methane producer more often (13/23 [56.5%] vs. 25/68 [36.5%], p?=?0.07) and had greater area under curve (AUC) for methane (2415 [435–23,580] vs. 1335 [0–6562.5], p?=?0.02) than non-constipating IBS. Methane producers (8/13 [61.5%]) and 5/10 (50%) non-producers had abnormal CTT (marker retention: 36-h, 53 [0–60] vs. 19 [8–56], p?=?0.06; 60-h, 16 [0–57] vs. 13 [3–56], p?=?0.877). Six and 7/13 methane producers were randomized to rifaximin and placebo, respectively. Rifaximin reduced AUC for methane more (6697.5 [1777.5–23,580] vs. 2617.5 [562.5–19,867.5], p?=?0.005) than placebo (3945 [2415–12,952.5] vs. 3720 [502.5–9210], p?=?0.118) at 1 month. CTT normalized in 4/6 (66.7%) on rifaximin (36-h retention, 54 [44–57] vs. 36 [23–60], p?=?0.05; 60-h, 45 [3–57] vs. 14 [11–51], p?=?0.09) but none on placebo (p?=?0.02) (36-h, 31 [0–60] vs. 25 [0–45], p?=?0.078; 60-h, 6 [0–54] vs. 12 [0–28], p?=?0.2). Weekly stool frequency (3 [1–9] and 7 [1–14], p?=?0.05) and forms improved with rifaximin than placebo.

Conclusion

Rifaximin improves CC by altering methane production and colon transit.

Trial registration

Clinical Trial Registry, India: REF/2012/01/003216

Open image in new window

? ?

     

Development and testing of the Role-related Meaning Scale for Staff in Pediatric Oncology

The purpose of this study was to develop and test the Role-Related Meaning Scale for Staff in Pediatric Oncology (RRMS) to determine the internal consistency and the content and construct validity of this two-phase instrument. During phase 1 (item generation, content validation, and initial field testing), 23 nurses from two cancer centers participated, and during phase 2 (instrument testing), 89 nurses from one pediatric research center participated. The nurses completed either the RRMS only (phase 1) or six instruments including the RRMS (phase 2) to assess the following research variables: role-related meaning, group cohesion, organizational commitment, work satisfaction, and intent to leave. The RRMS was revised after phase 1 because the results yielded a ceiling effect and three overlapping items. The Cronbach alpha for the phase 2 total RRMS was.83, and four of the five hypothesized relations were confirmed (P =.04). Therefore, the RRMS was concluded to be an internally consistent instrument that has content validity and beginning construct validity. Future studies will examine whether the RRMS adequately measures the change in meaning brought about by interventions designed to increase role-related meaning among nurses.     

Inhibition of Japanese encephalitis virus infection by diethyldithiocarbamate is independent of its antioxidant potential

Diethyldithiocarbamate (DDTC), a low molecular weight dithiol, has been described as an immunomodulator and modifier of diverse biological actions in human and animal models, and has also been shown to be effective in several disease conditions. Therefore, we studied the therapeutic aspect of DDTC in providing inhibition of Japanese encephalitis virus (JEV) infection. DDTC tested at various doses (10-100 micromol/kg) revealed that administration at low concentration (10 micromol/kg; i.p.) on alternate days prolonged the average survival time (AST) of mice infected with lethal dose of JEV (102 LD50, i.c.) and delayed progression of the disease. The low dose also provided > 80% survival in sub-clinical (10(5) LD50, i.c.) JEV infection. Administration of DDTC to JEV-infected mice enhanced the inducible nitric oxide synthase (iNOS) activity in brain and level of serum tumour necrosis factor-alpha (TNF-alpha). We have recently demonstrated the production of nitric oxide (NO) via induction of iNOS activity is meditated by circulating macrophage-derived factor (MDF), which may be responsible for the delayed progression of the disease. DDTC-mediated inhibition of JEV is believed to involve the augmentation of protective role of MDF as evidenced by the observation that pretreatment with anti-MDF antibody significantly decreased the AST of mice and together with the inhibition of iNOS activity. Interestingly, DDTC alone did not stimulate iNOS and TNF-alpha in mock-infected normal mice. These results show that DDTC may have a possible therapeutic role during JEV infection.     

Effectiveness of the clinical pathway in the management of congestive heart failure

BACKGROUND: The prevalence of congestive heart failure (CHF) in the United States is approximately 4 million, with associated annual health care expenditures exceeding dollar 8 billion. Clinical pathways for CHF have been developed, but they have not been rigorously evaluated regarding efficacy and improvement in the quality of care. We sought to evaluate the effect of a CHF clinical pathway on hospital charges, length of stay, and use of angiotensin-converting enzyme (ACE) inhibitors in patients with CHF in a retrospective cohort study. METHODS: We studied 371 patients (age range, 44-92 yr) with discharge diagnoses of CHF in a 376-bed community hospital between July 1996 and December 1997. We conducted chart reviews to determine length of stay, hospital charges, and use of ACE inhibitors. RESULTS: Of the 371 patients, 174 were assigned to the clinical pathway and 197 were not. Baseline characteristics of the two groups were similar. The benchmark of less than 4 days' in-hospital stay was achieved in 65% of patients on the pathway and 42% who were not on the pathway (odds ratio, 2.6; 95% confidence interval, 1.67-4.05; P < 0.001). The median hospital charges were lower in the group on the clinical pathway (dollar 3,000 versus dollar 5,500, P < 0.001). In addition, 81% of the patients on the clinical pathway were administered ACE inhibitors, compared with 48% of equally eligible patients from the nonpathway group (odds ratio, 4.68; 95% confidence interval, 2.85-7.72; P < 0.001). CONCLUSION: The clinical pathway for CHF was associated with increased use of ACE inhibitors as well as reduced length of stay and hospital charges.     

Prostate specific antigen ratio: for diagnosis and assessment of aggressiveness of malignancy of prostate

The search for a perfect tumour marker, which would be able to distinguish benign from malignant enlargement of prostate accurately, is still not complete. Total Prostate Specific Antigen (TPSA), a good test, has it's own inadequacies but Free Prostate Specific Antigen (FPSA) to TPSA ratio is emerging as a better adjuvant to it. This prospective study was done to verify the utility of FPSA to TPSA ratio in diagnosis of malignancy of prostate and its relationship to Gleason grading (indicating the aggressiveness) of adenocarcinoma of prostate. 100 patients with urinary symptoms, who were above fifty years of age and had prostatic enlargement, formed the study group. TPSA and FPSA were assayed by ELISA method and FPSA to TPSA ratio was calculated. Prostatic biopsy of all the cases was obtained and diagnostic histopathology and Gleason grading (in cases where adenocarcinoma was diagnosed) was done. Sensitivity, specificity, predictive value of positive test and predictive value of negative test for TPSA and FPSA to TPSA ratio were calculated. They were found to be 100%, 76.7%, 74.1% and 100% for TPSA and 82%, 100%, 100%, 89% for FPSA/TPSA ratio. Thus making it very obvious that FPSA to TPSA ratio is an excellent adjuvant to TPSA for diagnosis of malignancy of prostate increasing the specificity and predictive value for positive test. An inverse correlation (correlation coefficient = -0.95) was also found between PSA ratio and aggressiveness of prostate cancer, pointing towards its capability to predict the histological (Gleason) grade of the tumour.