Hypomethylation of the XRE -1383 site is associated with the upregulation of CYP1A1 in gastric adenocarcinoma.

Owing to its broad substrate specificity of mainly xenobiotics and its preferential extrahepatic expression, cytochrome P450 1A1 (CYP1A1) is a principle member of the CYP detoxifying enzyme superfamily involving in carcinogenesis. Methylation status of 93 CpG sites, densely scattered within approximately 1.5 kb 5' regulatory region of CYP1A1, and its association with gene transcription was analyzed in tissue cohorts dissected from 40 patients with gastric cancer. Bisulfite sequencing and the resulting methylation percentages revealed dynamically methylated CpG sites located within or around xenobiotic response elements (XRE) 4-10, and a region of consistent hypermethylation located near proximal promoter, encompassing XRE2-3. Statistical analysis revealed significant differences of the methylation percentages at the CpG sites -1415 (0.032) and -1524 (P = 0.041) (located at the close upstream region of XRE10) between cancerous and normal gastric tissues as well as between those with and without lymphatic involvement. Quantitative real time PCR analysis showed that the CYP1A1 gene expression significantly increases in cancerous tissues compared to their normal tissue cohort, and is significantly associated with hypomethylation at the CpG site -1383 (P = 0.018) within the XRE10 motif. These data suggest that the variably methylated CpG site from the 5' regulatory region of CYP1A1, corresponding with the XRE10 regulatory region, is associated with its gene upregulation thus, is likely involved in gastric cancer incidence and metastasis. Methylation analysis of the CpG sites located within or around the XRE10 motif of the CYP1A1 promoter can be used as a potential marker to evaluate individual susceptibility to gastric cancer.

The position of the upper limb during shoulder arthroscopy does not affect the distance between axillary nerve and glenoid.

PURPOSE: The segment of the axillary nerve (AxN) near the glenoid rim is at risk of iatrogenic lesion during arthroscopic procedures. We hypothesize that the distance between the AxN and the glenoid rim is not modified by the patient's positioning. The primary objective was to compare the position of the AxN with the inferior glenoid rim in lateral decubitus or in beach chair and positions of the upper limb. METHODS: Sixteen shoulders were dissected in beach chair position with the shoulder in neutral rotation. Needle one was placed in the axillary nerve where it was the closest with the inferior glenoid rim. In lateral decubitus with traction and 70° of abduction needle two was placed in the AxN at the closest with the inferior glenoid rim. The glenoid rim was marked with a needle at 6 o'clock. In beach chair position, the distance between needle one and the glenoid needle was measured for six positions. In lateral decubitus, measures were done for two positions of abduction. In lateral decubitus with 70° of abduction, the distance between needle two and the glenoid needle was also measured. RESULTS: The mean distance between AxN and the inferior glenoid rim was 14.4 mm in reference position in beach chair. The results showed the absence of difference between the positions during surgery except for lateral decubitus with 70° of abduction. CONCLUSION: Our study showed that the position of the shoulder during arthroscopic procedures cannot take away the AxN from the inferior glenoid rim. LEVEL OF EVIDENCE: Level IV-basic science study.

Diagnostic characteristics of late-night salivary cortisol using liquid chromatography-tandem mass spectrometry.

OBJECTIVE: The objective of the study was to describe the diagnostic performance of a commercially available late-night salivary cortisol (NSC) assay using liquid chromatography tandem mass spectrometry. METHODS: We retrospectively identified 90 patients who had one or more NSC determinations: 52 patients in whom Cushing syndrome (CS) was excluded or could not be confirmed [group 1 (G1)] and 38 patients in whom CS was confirmed [group 2 (G2)]. Eighteen healthy volunteers served as controls. RESULTS: Baseline demographics in all groups were similar with regards to age, ethnicity, gender, and body mass index. NSC levels [median (range)] were higher in G2, 381 (64-13,500) ng/dl [10.51 (1.77-372.46) nmol/liter], compared with controls, 19.3 (2.1-416) ng/dl [0.53 (0.06-11.48) nmol/liter], and G1, 26 (4-176) ng/dl [0.72 (0.11-4.86) nmol/liter, P < 0.001]. The highest combined sensitivity (92%) and specificity (92%) was achieved at a cut point of 107 ng/dl (2.95 nmol/liter). Two or more NSCs were done in 32 of 52 G1 and 31 of 38 G2 patients. In G1 eight of 32 (25%) had at least one elevated [>100 ng/dl (2.76 nmol/liter)] NSC including two in whom both NSCs were elevated. In contrast, four of 31 (13%) in G2 had at least one normal NSC including one with four of five normal NSC values. None of the patients with CS had a NSC less than 60 ng/dl (<1.66 nmol/liter). Comparing G1 and G2, obtaining more than one saliva sample did not improve the diagnostic accuracy of NSC measurement (P = 0.64). CONCLUSION: The liquid chromatography tandem mass spectrometry assay to measure NSC is a simple and reliable test to screen patients suspected to have CS. Clinicians should be aware of appropriate cutoff values for proper interpretation of NSC and use additional tests when necessary.

Odor preferences in neonatal and weanling rats.

In order to establish odors which can be used in appetitive and aversive conditioning paradigms, naive rat pups, postnatal day 7 (i.e., PND 7) and weanlings (PND 25), were placed in a rectangular open field with an odorant at one or both ends. Time spent over each odor was measured for 3 min. At both ages subjects avoided peppermint, orange, and lemon odors in favor of fresh home-cage bedding. Comparing any of these three odorants with each other resulted in no significant differences in preferences. In experiments using banana odorant, equal time was spent between banana and no odorant. However, in a two-odorant choice between banana and peppermint, weanlings preferred banana whereas pups showed no preference. The results of this study indicate that in an appetitive learning paradigm, peppermint, orange, or lemon odors may be used, while in aversive learning paradigms banana odor may be more appropriate for weanlings.