Induction of esophageal tumors in zinc-deficient rats by single low doses of N-nitrosomethylbenzylamine (NMBA): analysis of cell proliferation, and mutations in H-ras and p53 genes

Dietary zinc deficiency in rats induces hyperplasia in the esophagus and increases N-nitrosomethylbenzylamine (NMBA)-induced esophageal tumor incidence. Previous work showed a direct relationship between epithelial cell proliferation and esophageal tumor incidence in rats given multiple doses of NMBA. We investigated the effects of single low doses of NMBA in zinc-deficient rats since a single dose of 5.0 mg/kg was reported to be non-carcinogenic in rats. Zinc-sufficient and deficient rats received a single i.g. dose of NMBA at 0.5 or 2.0 mg/kg. At week 14, tumor incidence was 50% with 0.8 +/- 1.0 tumors/rat, and 80% with 2.2 +/- 1.9 tumors/rat, in deficient groups, D(0.5) and D(2.0), that received the lower and higher dose, respectively. In addition, two small papillomas were found in one out of eight untreated zinc-deficient rats. None of the NMBA-treated or untreated zinc- sufficient rats had any tumors. Esophageal cell proliferation, as determined by proliferating cell nuclear antigen (PCNA) immunohistochemistry, showed that, irrespective of NMBA treatment, deficient esophagi had significant increases in the number of labeled cells, the total number of cells, and the labeling index, as compared with zinc-sufficient ones. Mutations in Ha-ras and p53 genes in esophageal tumors were detected by single strand conformation polymorphism (SSCP) analysis. DNA sequencing of variant conformers revealed a point mutation (GGA-->GAA, codon 12) in Ha-ras in 4/5 (80%) and 5/8 (63%) tumors, from D(0.5) and D(2.0) rats, respectively. Three out of eight tumors from D(2.0) rats exhibited SSCP mobility shifts within p53 exons 5 and 7: two tumors (2/8, 25%) had missense mutations and the third, a silent mutation. Of the two tumors with p53 mutations, one had a double mutation (transition at codon 164, TCA-->TTA; transversion at codon 241, AGT-->TGT), and the other tumor, a transition at codon 172 (AGA-->GGA), with amino acid changes in all cases. In parallel with PCNA expression, elevated p53 expression was associated with hyperplastic and dysplastic regions, as well as with tumors, in deficient esophagi. In short, these data indicate that dietary zinc deficiency, with its associated sustained increased cell proliferation in the esophagus, can drive an otherwise non-tumorigenic dose of NMBA into a highly tumorigenic one.      

Primary Sjögren's syndrome in children and adolescents: are proposed diagnostic criteria applicable?

OBJECTIVE: To compare the proposed criteria for the diagnosis of primary Sj?gren's syndrome (pSS) in childhood to the validated American-European Consensus Group (AECG) classification criteria for pSS in adults. METHODS: Charts of 7 children with pSS seen at British Columbia's Children's Hospital (BCCH) and data on 128 children identified through Medline in the English language literature between 1963 and 2003 were reviewed for pediatric and AECG criteria for pSS. The presence of > or = 4 criteria was required to satisfy the respective classification criteria. The expert clinical opinion of pediatric rheumatologists was considered the gold standard for diagnosis. RESULTS: A total of 24/62 (39%) cases satisfied the AECG criteria; 47/62 (76%) satisfied the proposed pediatric criteria. Inclusion of recurrent parotitis increased the sensitivity of the pediatric clinical criteria. From the cases, 78/133 (59%) satisfied the pediatric oral symptom criteria; only 6/78 (8%) had xerostomia in the absence of recurrent parotitis. There was no reported case of recurrent conjunctivitis in the absence of keratoconjunctivitis sicca. We found 101/130 (78%) cases had at least one positive autoantibody test result [antinuclear antibodies (ANA), rheumatoid factor (RF), SSA, SSB]; 78/123 (63%) had autoantibodies to SSA or SSB. CONCLUSION: The AECG adult criteria for pSS should not be applied to children as the sensitivity is unacceptably low. The inclusion of recurrent parotitis increases the sensitivity of the pediatric criteria, and recurrent parotitis should alert the clinician to the possibility of pSS. The inclusion of recurrent conjunctivitis did not improve the sensitivity over the AECG ocular criteria. The addition of ANA and RF to the AECG criteria did not change the number of patients satisfying the criteria for pediatric pSS.     

Mechanisms of MHC class I-restricted antigen presentation

The vertebrate immune system monitors whether an organism is invaded by pathogens. Therefore, each cell has to prove itself as healthy. This is achieved by presenting fragments of intracellular protein degradation products on the surface, i.e., each cell displays peptides on specialised proteins known as major histocompatibility complex (MHC) class I proteins. A displayed peptide has to pass certain constraints before its presentation: It has to be excised out of a protein, translocated into the endoplasmic reticulum (ER) and fit into the binding groove of a MHC molecule. In theory, alteration of the cellular protein profile by mutation or infection should force pathogen-specific T-cells to take action via recognition of foreign peptide bound to MHC class I molecules on the cell surface. Unfortunately, pathogens and tumours have evolved many ways to affect antigen presentation and to escape from immune response. Understanding the exact mechanisms of antigen presentation, i.e., protein cleavage and peptide binding by MHC molecules, would allow their manipulation by drugs and lead to the re-establishment of the correct antigen presentation pathway. This review will summarise current knowledge of the mechanisms of antigen presentation and discuss putative targets for therapeutic treatment as well as for vaccination strategies.     

Stridor due to cricoarytenoid arthritis in pauciarticular onset juvenile rheumatoid arthritis

A 2-year-old girl developed severe inspiratory and expiratory stridor 2 months after onset of pauciarticular juvenile rheumatoid arthritis (JRA). Direct laryngoscopy demonstrated that both vocal cords were immobile and approximated to each other in the midline secondary to arthritis of the cricoarytenoid joints. High dose corticosteroid therapy resulted in clinical and laryngoscopic improvement and tracheostomy was avoided. Cricoarytenoid arthritis can be a life threatening complication in JRA. Early institution of corticosteroids appears to be the treatment of choice.     

Confirmation of hepatitis C infection: a comparison of five immunoblot assays

BACKGROUND: Recently, new immunoblot assays for the detection of antibodies to hepatitis C virus (HCV) became available. STUDY DESIGN AND METHODS: The performance of five confirmatory anti-HCV immunoblot assays was studied with samples with known HCV antibody and HCV RNA status. The assays were a third-generation strip recombinant immunoblot assay (RIBA-3, Chiron Corp., Emeryville, CA), a second-generation HCV blot (DB-2 blot, Diagnostic Biotechnology, Singapore), the Wellcozyme HCV Western blot (Murex blot, Murex Diagnostics, Dartford, UK), an immunodot HCV assay (Matrix, Abbott Laboratories, Chicago, IL), and the third-generation HCV line immunoassay (Liatek-III, Organon Teknika, Boxtel, The Netherlands). RESULTS: Sensitivity on samples from 48 HCV RNA-positive, second-generation RIBA (RIBA-2)-positive persons and specificity on samples from 31 low-risk donors was 96 percent or better for all assays. The sensitivity on 31 HCV RNA-positive, RIBA-2- indeterminate samples was as follows: Liatek-III, 94 percent; RIBA-3, 90 percent; Murex blot, 61 percent; Matrix, 55 percent; and DB-2 blot, 39 percent. In testing 39 HCV RNA-negative, RIBA-2-indeterminate donor samples, the percentage found to be negative was Liatek-III, 77 percent; RIBA-3, 67 percent; Murex blot, 49 percent; DB-2 blot, 33 percent; and Matrix, 15 percent. The order of sensitivity on four HCV seroconversion series was (from high to low): RIBA-3, Liatek-III, DB-2 blot, Murex blot, and Matrix; the differences were small. CONCLUSION: Detection of HCV antibodies was not refined by the addition of new HCV antigens (NS5, E2/NS1), but by improved classical antigens (core, NS3, NS4). Replacement of the commonly used RIBA-2 will resolve the status of a high proportion of RIBA-2-indeterminate samples.     

Sensitivity and specificity of four assays to detect human T− lymphotropic virus type I or type I/II antibodies

BACKGROUND: Assays that detect human T-lymphotropic virus type I and type II antibody (HTLV-I/II) are widely used in the routine screening of blood donors. STUDY DESIGN AND METHODS: Four commercially available anti-HTLV-I (Fujirebio and Organon Teknika) or -HTLV-I/II assays (Murex and Ortho) were evaluated in various serum panels: A) HTLV-I-positive specimens (n = 41), confirmed by Western blot and polymerase chain reaction; B) a commercially available anti-HTLV-I/II panel; C) serial dilutions of sera from HTLV-I-positive individuals (n = 30), confirmed by immunofluorescence assay and Western blot: D) serial dilutions of HTLV-II-positive blood donors (n = 20), confirmed by Western blot and polymerase chain reaction, and E) sera from first-time blood donors (n = 1055). RESULTS: All four assays elicited reactions in all 82 HTLV-I- positive samples in Panels A, B, and C. Of 32 HTLV-II-positive specimens in Panels B and D, 31 (96.9%) reacted in the Organon Teknika assay and all 32 reacted in the remaining tests. Probit analysis of test results in Panels C and D indicated that the Fujirebio test was the most sensitive assay, followed by Organon Teknika, Ortho, and Murex. The specificities of Fujirebio, Murex, Organon Teknika, and Ortho tests in 1055 first-time blood donors were 99.9, 100, 99.6, and 99.9 percent, respectively. CONCLUSION: All four studied assays for detecting HTLV-I or HTLV-I/II antibodies are appropriate as screening tests.     

Cytokine genotypes correlate with pain and radiologically defined joint damage in patients with juvenile rheumatoid arthritis

OBJECTIVES: Single nucleotide polymorphisms (SNPs) in cytokine genes have been associated with risk of a number of autoimmune diseases. Moreover, some SNPs are associated with variations in rates of in vitro gene expression, and it is therefore possible that these functional polymorphisms may differentially affect inflammatory processes and disease outcome. This project's objective was to determine whether cytokine genotypes correlate with disease outcomes in patients with juvenile rheumatoid arthritis (JRA). METHODS: Genotypes of SNPs of pro-inflammatory cytokines, tumour necrosis factor-alpha -308G -->A, interleukin-6 (IL-6) -174G -->C and interferon-gamma +874G -->A, and anti-inflammatory, immunosuppressive cytokines, interleukin-10 -1082G -->A, -819C -->T and -592A -->C and transforming growth factor-beta1 (TGF-beta1) codon 10T -->C and codon 25G -->C, were determined for patients with JRA who previously participated in a long-term outcome study. Cytokine genotypes and clinical variables showing significant correlations with clinical outcomes at the alpha = 0.100 level in univariate analyses were entered in multivariate tests. RESULTS: In multivariate tests, the IL-6 genotype -174G/G was positively correlated with pain [regression coefficient B = 0.899, 95% confidence intervals (CI) 0.185, 1.612, P = 0.014]. The homozygous TGF-beta1 codon 25G/G genotype showed a protective effect against joint space narrowing on radiographs taken within 2 yr of disease onset, but confidence intervals were wide [odds ratio (OR) 0.176, 95% CI 0.037, 0.837 P = 0.029]. CONCLUSIONS: The correlation of IL-6 genotype with pain and the possible association of the TGF-beta1 codon 25 genotype with short-term radiographic damage (G/C with greater risk and G/G with decreased risk) suggests that both these polymorphisms may be useful early prognostic indicators. Further studies of the relation between cytokine genotypes and outcomes in patients with all forms of juvenile idiopathic arthritis (JIA) are warranted.     

Effects of adherence to treatment on short-term outcomes in children with juvenile idiopathic arthritis

OBJECTIVE: To determine the impact of adherence to treatment (medication and prescribed exercise) on outcomes in children with juvenile idiopathic arthritis (JIA). METHODS: In this longitudinal study, we studied parents of patients with JIA at the Montreal Children's Hospital and British Columbia Children's Hospital in Vancouver. Adherence was evaluated on a visual analog scale in the Parent Adherence Report Questionnaire. Outcomes of interest were active joint count, pain, child functional score on the Child Health Assessment Questionnaire, quality of life score on the Juvenile Arthritis Quality of Life Questionnaire, and parental global impression of overall well-being. The association between adherence to treatment and subsequent outcomes was evaluated using generalized estimating equations and logistic regression. RESULTS: Mean age and disease duration of our sample of 175 children were 10.2 and 4.1 years, respectively. Moderate adherence to medication was associated with lower active joint count (odds ratio [OR] 0.47, 95% confidence interval [95% CI] 0.22-0.99). Moderate adherence to exercise was associated with better functional score (OR 0.13, 95% CI 0.03-0.54), and lower pain during the last week (OR 0.14, 95% CI 0.04-0.50). Both high and moderate adherence to exercise were associated with parental perception of global improvement. CONCLUSION: Improved outcomes in patients who adhered to treatment underscores the need for clinicians to address adherence issues with their patients. Sustaining adherence, particularly to the more time-consuming treatment of exercise, is a challenge.     

Safety and Efficacy of Oral Transmucosal Fentanyl Citrate Compared to Morphine Sulphate Immediate Release Tablet in Management of Breakthrough Cancer Pain

Aim:

To compare the efficacy and safety of oral transmucosal fentanyl citrate (OTFC) and oral morphine in Indian patients with breakthrough episodes of cancer pain.

Materials and Methods:

In this randomized, open label, active controlled, clinical study, total 186 patients who regularly experienced 1-4 episodes of breakthrough cancer pain (BTCP) daily, over the persistent pain controlled by taking oral morphine 60 mg/day or its equivalent were randomized to receive either OTFC 200 mcg or oral morphine 10 mg for the treatment of BTCP for 3 days. Improvement in pain as determined by numerical rating scale (NRS) at 5, 15, 30, and 60 minutes of drug administration and percentage of BTCP episodes showing reduction in pain intensity by >33% at 15 minutes were primary efficacy endpoints. Secondary efficacy endpoints were requirement for rescue analgesia and global assessment by physician and patient. Data of both treatment groups were analysed by appropriate statistical test using software, STATISTICA, version 11.

Results:

Patients treated with OTFC experienced significantly greater improvement in pain intensity of breakthrough episodes compared to those treated with oral morphine at all assessment time points (P < 0.0001). 56% of breakthrough pain episodes treated with OTFC showed a greater than 33% reduction in pain intensity from baseline at 15 minutes compared to 39% episodes treated with oral morphine (P < 0.0001). Patient''s and physician''s global assessment favoured OTFC than oral morphine (P < 0.0001). Requirement of rescue analgesia in both the study groups was similar (P > 0.05). Both study drugs were well tolerated.

Conclusions:

OTFC was found to provide faster onset of analgesic effect than immediate release oral morphine in management of breakthrough cancer pain.