Targeting of interleukin-13 receptor on human renal cell carcinoma cells by a recombinant chimeric protein composed of interleukin-13 and a truncated form of Pseudomonas exotoxin A (PE38QQR)

We have previously shown that human renal cell carcinoma (RCC) cells express large numbers of interleukin-13 receptors (IL-13R), a newly described hemopoietic growth factor receptor. To target tumor cells that express IL-13R, we have produced a chimeric protein composed of human IL-13 and a derivative of Pseudomonas exotoxin A, termed PE38QQR. We report here that IL13-PE38QQR is highly cytotoxic to many human RCC cell lines. IL-13R-negative cell lines or cell lines expressing low numbers of IL-13R ( < 300 sites/cell) that include human bone marrow- derived cells were not susceptible to the cytotoxic effect of IL 13- PE38QQR. The sensitivity of RCC cells to IL13-PE38QQR correlated positively with the density of IL-13R. The cytotoxic activity of IL13- PE38QQR was competed by an excess of IL-13 in a protein synthesis inhibition assay and confirmed by a clonogenic assay. Even though IL-13 and IL-4 are homologues and IL-4R and IL-13R have been proposed to share a receptor subunit, IL-4 did not compete for the cytotoxicity mediated by IL13-toxin on RCC. IL13-PE38QQR competes for [125I]-IL-13 binding sites on RCC cells, although at a lower affinity than the wild- type recombinant cytokine. Human T-cell, B-cell, and monocytic cell lines are unresponsive to the cytotoxic action of IL13-PE38QQR. Thus, our results indicate that IL13-PE38QQR is highly cytotoxic to human RCC cells, although it is not cytotoxic to a variety of normal hematopoietic cells. IL13-PE38QQR should be further investigated preclinically for the treatment of human RCCs.     

Quantitative assessment of Tn antigen in breast tissue micro-arrays using CdSe aqueous quantum dots

In this study, we examined the use of CdSe aqueous quantum dots (AQDs) each conjugated to three streptavidin as a fluorescent label to image Tn antigen expression in various breast tissues via a sandwich staining procedure where the primary monoclonal anti-Tn antibody was bound to the Tn antigen on the tissue, a biotin-labeled secondary antibody was bound to the primary anti-Tn antibody, and finally the streptavidin-conjugated AQDs were bound to the biotin on the secondary antibody. We evaluated the AQD staining of Tn antigen on tissue microarrays consisting of 395 cores from 115 cases including three tumor cores and one normal-tissue core from each breast cancer case and three tumor cores from each benign case. The results indicated AQD-Tn staining was positive in more than 90% of the cells in the cancer cores but not the cells in the normal-tissue cores and the benign tumor cores. As a result, AQD-Tn staining exhibited 95% sensitivity and 90% specificity in differentiating breast cancer against normal breast tissues and benign breast conditions. These results were better than the 90% sensitivity and 80% specificity exhibited by the corresponding horse radish peroxidase (HRP) staining using the same antibodies on the same tissues and those of previous studies that used different fluorescent labels to image Tn antigen. In addition to sensitivity and specificity, the current AQD-Tn staining with a definitive threshold was quantitative.     

Invariant Natural Killer T Cells Contribute to the Allergic Response in Cow's Milk Protein-Sensitized Mice

Background: Little is known about the contribution of the invariant natural killer T (iNKT) cells in the onset of food allergy. Using a mouse model for cow's milk allergy the function of iNKT cells was investigated. Methods: Mice were sensitized orally with casein or whey proteins. One hour before the sensitizations the mice were injected intraperitoneally with α-galactosylceramide (αGalCer) or control. One week after the last sensitization acute allergic skin reactions were measured. Furthermore, in the liver, spleen and mesenteric lymph nodes (MLN) percentages of iNKT cells were analyzed and liver lymphocyte restimulation assays were performed. Results: Whey- or casein-sensitized mice treated with αGalCer showed enhanced acute allergic skin reactions. The percentage of iNKT cells in the liver of sensitized mice was reduced compared to sham-sensitized mice. αGalCer treatment was found to deplete iNKT cells in the liver of sensitized as well as sham-sensitized mice, and these hepatocytes did not respond to ex vivo restimulation with αGalCer. αGalCer treatment did not reduce iNKT cell percentages in the spleen and MLN of sham-sensitized mice but abrogated the increase in iNKT cell percentage in the spleen upon whey sensitization, whereas it enhanced the iNKT cell percentage in the MLN of casein-sensitized mice. Due to the repeated application of αGalCer, livers were functionally depleted of iNKT cells. This resulted in an increased allergic effector response which was most pronounced in whey-sensitized mice and associated with enhanced whey-specific immunoglobulin levels. Conclusion: iNKT cells may suppress cow's milk allergic symptoms in mice and may differentially regulate oral sensitization for casein and whey.     

Initiation of health-behaviour change among employees participating in a web-based health risk assessment with tailored feedback

Background

Biological monitoring of healthy workers exposed to hazardous dusts lack validated screening tools. Induced sputum (IS) cellular profile was compared with bronchoalveolar lavage fluid (BALF) profile in asbestos exposed workers in order to assess its usefulness in monitoring workers exposed to asbestos for a long period of time.

Methods

IS and BALF analysis was performed in 39 workers of a car brakes and clutches factory that uses chrysotile asbestos. Selection criteria were an employment history of > 15 years and the absence of a diagnosis of pneumonoconiosis. The type of cells, the existence of dust cells, of iron laden macrophages and of asbestos bodies were assessed and compared between IS and BALF samples.

Results

35 IS samples (90%) had dust cells, 34 (87%) iron laden macrophages and in 8 samples (21%) asbestos bodies were found. In most samples neutrophils were dominated. Samples with asbestos bodies (ABs) had significantly higher lymphocytes and lower neutrophils count compared with the samples without ABs. Macrophages and neutrophils in IS and BALF exhibited significant inter-relations (Spearman's rho: 0.26-0.29, p < 0.05) while IS lymphocytes count showed an inverse relation with BALF neutrophils (Spearman's rho: -0.36). Neutrophils and dust cells were highly correlated between the samples (Spearman's rho: 0.35, p < 0.05) while IS dust cells and lymphocytes were inversely related (Spearman's rho: -0.36, p < 0.05). More years of employment in the company was related with more neutrophils (Spearman's rho: 0.26) and less lymphocytes (Spearman's rho: -0.33) count. In multivariate analysis the presence of AB in IS samples was strongly related to the presence of asbestos bodies and lymphocytes count in BALF samples.

Conclusions

IS and BALF analysis showed a similar cellular profile indicating that IS sampling in exposed workers to asbestos as a less invasive and expensive method may be useful in providing an insight both for inhalation of dusts and inflammatory processes in the lung.     

Cholangiopathy associated with portal hypertension

Portal cholangiopathy encompasses a group of abnormalities of the biliary system and gallbladder that occur secondary to chronic portal vein thrombosis and collateral venous circulation. Chronic obstruction of the portal vein is a frequent cause of gastrointestinal variceal bleeding, but data on biliary tract abnormalities are limited. We report the case of a male patient with obstructive jaundice secondary to portal cholangiopathy. We describe the pathogenesis of this entity, and the various diagnostic and therapeutic options available.     

Developing best practice for fungal specimen management: audit of UK microbiology laboratories

This study represents an audit of microbiology laboratories in the UK to ascertain whether they are aware of, or follow, the Health Protection Agency (HPA) National Standard Methods Standard Operating Procedure (NSM SOP) for the investigation of dermatological specimens for superficial mycoses, or use a locally adapted version. A questionnaire audit was distributed to 179 NHS microbiology laboratories throughout England, Wales, Scotland and Northern Ireland. The NSM SOP was followed by 92% of laboratories for the microscopy of dermatological samples; light microscopy/ KOH digestion was used by 63% and fluorescence microscopy/KOH digestion by 29% of laboratories. Preliminary reports post-microscopy were issued by 98% of laboratories, with 93% issuing reports within 48 hours. Adherence to the NSM SOP guidelines for culture was low; only 34% of laboratories incubated microscopy-negative specimens for the recommended 14 days, while approximately 60% incubated microscopy-positive specimens for 21 days. The culture medium recommended by the NSM SOP was used in 82% of laboratories. Comments were added to culture reports by 51% of laboratories; most were added manually and comments varied between laboratories. Nail samples were the most common sample received from primary care, followed by skin and hair. These results show no significant difference in the rate of microscopy positives versus culture positives. Microscopy and culture are the easiest and cheapest methods available to UK laboratories for the investigation of suspected superficial fungal infections. Although most laboratories included in this audit claimed to follow the NSM SOP for microscopy and culture, these results show that the techniques used vary throughout the UK. To maximise the service provided to primary care, UK laboratories should use standardise methods based on the NSM SOP.