Allergen avoidance in the secondary and tertiary prevention of allergic diseases: does it work?

Although allergen avoidance is widely recommended as part of a secondary and tertiary prevention strategy for allergic diseases, a clear-cut demonstration of its effectiveness is still lacking. Ongoing observational secondary prevention cohorts show that sensitisation to mite can be prevented in the short term by allergen avoidance measures, but further follow-up of these children is needed to show if this effect can be sustained, as well as to ascertain its impact on allergic disease. More well-designed trials are still required before we can give any conclusive advice to our patients. Considering the management of allergy, current evidence suggests that interventions in children (either single or multifaceted) may be associated with some beneficial effect on asthma control, but no conclusive evidence exists regarding rhinitis or eczema. Conversely, there is little evidence to support the recommendation of allergen avoidance methods in adults with asthma and rhinitis. There is a need for an adequately designed trial assessing the effects of a multifaceted intervention in this age group.     

Release of soluble transferrin receptor from the surface of human leukemic HL60 cells

Information regarding transferrin (Tf) receptor degradation is largely incomplete. HL60 cells were shown to release to their growth medium a Tf-binding protein which could be immunoprecipitated by anti-Tf receptor monoclonal antibodies (MoAbs) B3/25 and OKT9. Soluble Tf receptor was detected in the medium within one hour of replating of cells, and its release was inhibited at 4 degrees C. The affinity of Tf for the soluble receptor released by cells (kd = 2.3 x 10(-10) mol/L) was slightly lower than its affinity for the detergent-solubilized cellular receptor (kd = 1.2 x 10(-10) mol/L). 125I-Tf internalized and released by cells subsequently bound to Tf receptor released by the same cells, and soluble Tf receptor in the conditioned medium (CM) inhibited 125I-Tf binding to intact cells. The soluble Tf receptor isolated from the CM was smaller (78,000 daltons) than the cell surface receptor (94,000 daltons) when analyzed by gel electrophoresis under reducing conditions. Isolated cell membranes readily released soluble receptor; however, this release could be blocked by protease inhibitors. The soluble Tf receptor may represent the extracytoplasmic domain of the cellular Tf receptor released from the surface of HL60 cells through proteolytic cleavage by a membrane-based protease.     

Lymphocyte T helper-specific reactivity in sustained responders to interferon and ribavirin with negativation (seroreversion) of anti-hepatitis C virus.

BACKGROUND: Seroreversion, negativation of anti-hepatitis C virus previously positive, is sometimes found in some chronic hepatitis C-sustained responders (SRs) to antiviral therapy. AIMS: To determine the probability of seroreversion in SR treatment with Interferon and Ribavirin, and lymphocyte T helper (CD4+) reactivity to HCV antigens. METHODS: Thirty SR were followed on average for 54.8 months. Anti-HCV was tested by third generation test. Peripheral blood mononuclear cells (PBMCs) were isolated from venous blood and cultured to evaluate CD4+ proliferation in response to 2 microg/ml of eight HCV recombinant antigens from core, NS3, NS4, NS5 regions. RESULTS: Seroreversion was verified in 23% of patients (7/30), appearing at 47.5+/-24.0 months. The probability of anti-HCV loss in this group was 25% at 56 months after ending therapy. In 57% (4/7), anti-HCV returned to positive. These 7 SR patients with seroreversion also showed weaker CD4+ reactivity in 5% of tests (3/56) than the remaining 23 anti-HCV-positive SRs who showed stronger reactivity in 18% of tests (33/184), P=0.036. CONCLUSIONS: One-quarter of the SR showed seroreversion of anti-HCV and weaker CD4+ specific HCV proliferation than those who remained anti-HCV positive. The data suggest that complete viral eradication is a possible and achievable clinical objective.     

Pneumothorax and other lung diseases: effect of altered resolution and edge enhancement on diagnosis with digitized radiographs

Prior studies have shown that pneumothorax is one of the more difficult entities to diagnose with digitized radiography. This study was designed to test whether increasing resolution from 1.25 to 2.5 line pairs per millimeter (lp/mm) and image processing (edge enhancement from unsharp masking) would increase accuracy and confidence in the diagnosis of pneumothorax, as well as normal cases and other forms of lung disease. Conventional radiographs were digitized with use of a laser reader and then reformatted as film hard copy. Eleven observers read 35 cases reformatted in three different ways (1.25 lp/mm, 2.5 lp/mm, 1.25 lp/mm unsharp mask). The images with finer resolution (2.5 lp/mm) and unsharp mask images were superior to those with coarser resolution (1.25 lp/mm) for the diagnosis of pneumothorax. There was no difference in diagnostic accuracy for normal patients. For abnormalities other than pneumothorax, the unsharp mask images were significantly worse. Confidence in the diagnosis of pneumothorax and other abnormalities was highest with the finest resolution (2.5 lp/mm).     

Treatment and prognostic factors in patients with hepatocellular carcinoma.

INTRODUCTION: Hepatocellular carcinoma is a leading cause of death from cancer worldwide. Survival of patients depends on tumor extension and liver function, but yet there is no consensual prognostic model. AIMS: To evaluate the influence on survival of pretreatment parameters (clinico-laboratorial, liver function, tumor extension, Okuda and Cancer of the Liver Italian program (CLIP) staging) and treatment modalities. METHODS: We retrospectively analyzed 207 patients, diagnosed between 1993 and 2003. The initial treatment was: surgery--six patients; radiofrequency ablation--21; percutaneous ethanol injection--29; transarterial chemoembolization--49; tamoxifen--49; supportive care alone--53. Factors determining survival were assessed by Kaplan-Meier method and Cox regression models. RESULTS: Median survival was 24 months. In univariate analysis, Child-Pugh classification and Model for end-stage liver disease (MELD) score, portal vein thrombosis (PVT), tumor size, number of lesions, Okuda and CLIP scores were all associated with prognosis (P < 0.001). Alpha-fetoprotein levels were not predictive of survival. Independent predictors of survival were ascites, bilirubin, PVT and therapeutic modalities (P < 0.001). In early stage hepatocellular carcinoma (HCC), survival was similar for both percutaneous ablation modalities, either radiofrequency or ethanol injection (P = NS). In advanced HCC, survival was better in patients receiving tamoxifen than supportive care alone (P < 0.001). CONCLUSION: This study reinforces the importance of baseline liver function (Child-Pugh classification and MELD score) in the survival of patients with HCC, although staging systems allowed the stratification of patients in different prognostic groups. Ascites, bilirubin and PVT were independent pretreatment predictors of survival. All treatments influenced the patient's outcome, whether in early or advanced stages.