Publications

BACKGROUND AND AIM

The endoscopic landmark of esophagogastric junction (EGJ) for diagnosis of Barrett's esophagus (BE) differs between Japan and Western countries. Japanese endoscopists use the distal end of the lower esophageal palisade vessels to localize EGJ. In the West, endoscopists use the proximal gastric folds because of concerns that palisade vessels may be difficult to recognize. We evaluated whether there were differences between American and Japanese endoscopists in the recognition of palisade vessels.

METHOD

A total of 82 patients were enrolled in this study. Patients were referred for diagnostic esophagogastroduodenoendoscopy (EGD) at the Veterans Affairs Palo Alto Health Care System, from May to July 2008. American and Japanese endoscopists evaluated the EGJ of patients undergoing diagnostic EGD. We analyzed the differences in the recognition of the distal end of palisade vessels. We calculated the kappa statistic to measure interobserver variability.

RESULTS

Based on localization using the distal end of the palisade vessels, American and Japanese endoscopists identified the EGJ in 87.8% (72/82) and 89.0% (73/82) of cases, respectively. The kappa statistic for visualization of EGJ was 0.88 [95% confidence interval (CI): 0.73-1.00].

CONCLUSION

American and Japanese endoscopists similarly recognized the distal end of palisade vessels as EGJ.

SUMMARY

To determine the laboratory reproducibility of urine N-telopeptide and serum bone-specific alkaline phosphatase measurements, we sent identical specimens to six US commercial labs over an 8-month period. Longitudinal and within-run laboratory reproducibility varied substantially. Efforts to improve the reproducibility of these tests are needed.

INTRODUCTION

We assessed the laboratory reproducibility of urine N-telopeptide (NTX) and serum bone-specific alkaline phosphatase (BAP).

METHODS

Serum and urine were collected from five postmenopausal women, pooled, divided into identical aliquots, and frozen. To evaluate longitudinal reproducibility, identical specimens were sent to six US commercial labs on five dates over an 8-month period. To evaluate within-run reproducibility, on the fifth date, each lab was sent five identical specimens. Labs were unaware of the investigation.

RESULTS

Longitudinal coefficients of variation (CVs) ranged from 5.4% to 37.6% for NTX and from 3.1% to 23.6% for BAP. Within-run CVs ranged from 1.5% to 17.2% for NTX. Compared to the Osteomark NTX assay, the Vitros ECi NTX assay had significantly higher longitudinal reproducibility (mean CV 7.2% vs. 30.3%, p < 0.0005) and within-run reproducibility (mean CV 3.5% vs. 12.7%, p < 0.0005).

CONCLUSIONS

Reproducibility of urine NTX and serum BAP varies substantially across US labs.

Degeneration of language regions in the dominant hemisphere can result in primary progressive aphasia (PPA), a clinical syndrome characterized by progressive deficits in speech and/or language function. Recent studies have identified three variants of PPA: progressive non-fluent aphasia (PNFA), semantic dementia (SD) and logopenic progressive aphasia (LPA). Each variant is associated with characteristic linguistic features, distinct patterns of brain atrophy, and different likelihoods of particular underlying pathogenic processes, which makes correct differential diagnosis highly clinically relevant. Evaluation of linguistic behavior can be challenging for non-specialists, and neuroimaging findings in single subjects are often difficult to evaluate by eye. We investigated the utility of automated structural MR image analysis to discriminate PPA variants (N=86) from each other and from normal controls (N=115). T1 images were preprocessed to obtain modulated grey matter (GM) images. Feature selection was performed with principal components analysis (PCA) on GM images as well as images of lateralized atrophy. PC coefficients were classified with linear support vector machines, and a cross-validation scheme was used to obtain accuracy rates for generalization to novel cases. The overall mean accuracy in discriminating between pairs of groups was 92.2%. For one pair of groups, PNFA and SD, we also investigated the utility of including several linguistic variables as features. Models with both imaging and linguistic features performed better than models with only imaging or only linguistic features. These results suggest that automated methods could assist in the differential diagnosis of PPA variants, enabling therapies to be targeted to likely underlying etiologies.