Impact of aging on gastrointestinal mucosal immunity

More than two million tympanotomy tubes are placed annually in the United States, making this operation the most common performed on children. This article provides an overview of the applications of tympanotomy tubes for the treatment for otitis media in childhood. The indications for tube placement are discussed; a visual guide for managing children with tympanostomy tubes is presented; an approach to dealing with tube complications is outlined; and guidelines for referral to a pediatric otolaryngologist are suggested.     

Stress activated cytokines and the heart

The ability of myocardium to successfully compensate for, and adapt to, stress ultimately determines whether the heart will decompensate and fail, or whether it will instead maintain preserved function. Despite the importance of the myocardial response to environmental stress, very little is known with respect to the biochemical mechanisms that are responsible for mediating and integrating the stress response in the heart. In the present review we will summarize recent experimental material which suggests that cytokines that are expressed within the myocardium in response to a environment injury, namely tumor necrosis factor-alpha (TNF-alpha), interleukin-1 (IL-1) and interleukin-6 (IL-6), may play an important role in initiating and integrating homeostatic responses within the heart. However, these 'stress-activated' cytokines all have the potential to produce cardiac decompensation when expressed at sufficiently high concentrations. Accordingly, the theme that will emerge from this discussion is that the short-term expression of stress-activated cytokines within the heart may provide the heart with an adaptive response to stress, whereas long-term expression of these molecules may be frankly maladaptive by producing cardiac decompensation.     

Automated 3-D registration of MR and CT images of the head

This paper discusses the application of voxel similarity measures in the automated registration of clinically acquired MR and CT data of the head. We describe a novel single-start multi-resolution approach to the optimization of these measures, and the issues involved in applying this to data having a range of different fields of view and sampling resolution. We compare four proposed measures of voxel similarity using the same optimization scheme when presented with 10 pairs of images with a range of initial misregistrations. The registration estimates are compared with those provided by manual point-based registration and evaluated by visual inspection to give an assessment of the robustness and accuracy of the different measures. One full-volume CT image set is used to investigate the performance of each measure when used to align truncated images from different regions in the head. The soft tissue correlation and mutual information measures were found to provide the most robust measures of misregistration, providing results comparable to or better than those from manual point-based registration for all but the most truncated image volumes.     

Effect of growth factors on growth of bovine parathyroid cells in serum-free medium

Published work has suggested a possible role of the epidermal growth factor receptor (EGFr) in parathyroid disease. Bovine parathyroid cells (BPCs) are frequently used as a tissue model for studying parathyroid disorders. We have studied the effect of the EGFr ligands EGF and transforming growth factor alpha (TGFalpha), alone and with insulin-like growth factors IGF-I and IGF-II on BPC growth. Experiments were run in triplicate and repeated three times. Cell numbers were assessed on day 5 by colorimetric MTT assay as well as by tritiated thymidine uptake. Results show that TGFalpha alone (p < 0.05) and IGF-I and IGF-II alone (p < 0.05) significantly stimulated growth over controls (t-test). Furthermore, the combination of TGFalpha with IGF-I and IGF-II exhibited significant enhancement above that seen with IGF-I and IGF-II alone (p < 0.01). EGF did not stimulate growth over controls. EGFr may be expressed in BPCs, but TGFalpha exhibits a more potent growth stimulus than EGF. Addition of IGF-I or IGF-II to the growth medium further enhances this effect.     

Cocaine alters the respiratory burst and phagocytic activity of murine macrophages

Ninety-five patients with suspected acute myocardial infarction were randomly allocated on admission to hospital on a double blind basis to treatment with lorcainide, a Class 1C anti-arrhythmic drug, or matching placebo. Treatment was continued for 6 weeks. Twenty-four-hour ECG tape recordings were made immediately on admission, on the sixth or seventh day after admission, and again just before the end of the treatment period. Lorcainide was shown to be an effective anti-arrhythmic agent. The study was not designed to evaluate the effect of lorcainide on survival, but there were nine deaths among the 49 patients treated with lorcainide compared with only one in the patients given placebo. These findings are consistent with the results of the First and Second Cardiac Arrhythmia Suppression trials (CAST and CAST-II). This study was carried out in 1980 but was not published at the time: it now provides an interesting example of 'publication bias'.