Brugada-type patterns are easily observed in high precordial lead ECGs in collegiate athletes

Background

Displacement of ECG leads can result in unwarranted findings. We assessed the frequency of Brugada-type patterns in athletes when precordial leads were purposely placed upward.

Methods

Four hundred ninety-one collegiate athletes underwent two ECGs: one with standard leads, one with V1 and V2 along the 2nd intercostal space. A positive Brugada-type pattern was defined as ST elevation in V1 or V2 consistent with a Type 1, 2, or 3 pattern in the high-lead ECG. A control group was comprised of 181 outpatients.

Results

No Type 1 patterns were seen. In 58 athletes (11.8%), a Brugada-type 2 or 3 pattern was observed. Those with Brugada-type 2 or 3 patterns were more likely male, taller, and heavier. In the control group, 18 (9.9%) had Brugada-type 2 or 3 patterns and were more likely male.

Conclusions

Proper lead positioning is essential to avoid unwarranted diagnosis of a Brugada-type ECG, especially in taller, heavier male athletes.     

Molecular markers for predicting response to tamoxifen in breast cancer patients

Tamoxifen is one of the most effective treatments for breast cancer. Standard practice is to select patients who are likely to respond to this therapy through the evaluation of estrogen receptor (ER) and progesterone receptor (PR) in the primary tumor tissue. Over the past 25 yr that physicians have been using ER determination to guide tamoxifen use, numerous studies have demonstrated that this molecular marker is useful in predicting benefit from tamoxifen. ER has been analyzed for many years using ligand-binding assays. However, current practice involves the use of immunohistochemical-based assays to detect ERα Immunohistochemistry (IHC) has several advantages. For example, IHC evaluates tumor cell heterogeneity, can be used to study small samples, is less expensive, and allows direct correlation with multiple histopathological tumor features and other molecular markers. PR, an estrogen-responsive protein, can also be useful in predicting response to tamoxifen in specific clinical situations. In recent years, several other markers of tamoxifen response have been examined, including: pS2 (another estrogen-regulated protein), heat-shock proteins 27 and 70, bcl-2 protein, c-erbB-2 (HER-2/neu) oncoprotein, and mutated p53 tumor suppressor protein. In this article, we present an analysis of the data on these new molecular markers. Overall, from numerous studies, the data indicate that in addition to ERα bcl-2 is a potential candidate to help further improve our ability to predict response to tamoxifen. ER and bcl-2 are the most useful molecular markers to better identify breast cancer patients who will respond to tamoxifen and who will have prolonged survival.     

A new method for quantitative analysis of dentinal tubules

Conventional methods to estimate the number of dentinal tubules cannot be considered reliable and repeatable, because results depends on the operator outlining of the tubules contours. In this study, we propose a totally automated computerized analysis technique to evaluate dentinal tubules and their surface area. The comparison test of these conventional with a semi-automatic methods shows that the automated analysis allowed a reliable identification and numbering of dentinal tubules, by means of high-quality images. No statistically significant difference exists in the number of tubules and the total tubule surface area between the control and test groups.     

Liver infiltrating mononuclear cells in children with type 1 autoimmune hepatitis

OBJECTIVE: To investigate infiltrating cells in the liver of children with type 1 autoimmune hepatitis (AH-1). METHODS: liver biopsies from 24 untreated AH-1 patients (14 children, 10 adults), five patients with hepatitis C virus related chronic hepatitis (HCV), and 10 control liver specimens (CL) were processed for immunohistochemical cell characterisation. RESULTS: Two different cell distribution patterns were detected in the liver of patients with AH-1: (1) CD4(+) and CD20(+) cells were found in the central areas of the portal tracts (portal distribution); (2) CD8(+) cells were observed at the periphery of the portal space (periportal distribution). Some cell subsets, like CD56, CD57, Fas-L, and Bak, showed a non-defined distribution pattern. The presence of two well defined patterns of cell distribution was not observed in HCV and CL (CD4(+), CD20(+), and CD8(+) cells were uniformly distributed in the portal space). In AH-1 and CL, the NK markers CD56 and CD57 were found scattered throughout the liver parenchyma. However, in HCV biopsies, CD56(+) cells were also clearly increased in both the portal and the periportal areas. Biopsies of AH-1 and HCV patients showed a uniform distribution of Fas-L and Bak in the portal and periportal areas, with Bak staining also detected in the hepatic parenchyma. CONCLUSIONS: Despite clinical and genetic differences, there was a similar distribution of liver infiltrating mononuclear cells in children and adults with AH-1. These results raise the possibility of reclassifying cryptogenic chronic hepatitis by immunohistochemical analysis of infiltrating liver cells.     

Sequence comparison of human and yeast telomeres identifies structurally distinct subtelomeric domains

We have sequenced and compared DNA from the ends of three human chromosomes: 4p, 16p and 22q. In all cases the pro-terminal regions are subdivided by degenerate (TTAGGG)n repeats into distal and proximal sub- domains with entirely different patterns of homology to other chromosome ends. The distal regions contain numerous, short (<2 kb) segments of interrupted homology to many other human telomeric regions. The proximal regions show much longer (approximately 10-40 kb) uninterrupted homology to a few chromosome ends. A comparison of all yeast subtelomeric regions indicates that they too are subdivided by degenerate TTAGGG repeats into distal and proximal sub-domains with similarly different patterns of identity to other non-homologous chromosome ends. Sequence comparisons indicate that the distal and proximal sub-domains do not interact with each other and that they interact quite differently with the corresponding regions on other, non- homologous, chromosomes. These findings suggest that the degenerate TTAGGG repeats identify a previously unrecognized, evolutionarily conserved boundary between remarkably different subtelomeric domains.