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Notes: The purpose of this study was to characterize the level of sleepiness/alertness following the nocturnal administration of dexamethasone. Thirteen healthy men participated in this study. Following the initial screening, dexamethasone (4 mg) or placebo was administered at 22:30 hr in a randomized double-blind procedure. Subjects were given nap opportunities at 23:00, 1:00, 3:00, 4:30, 5:30, 7:30, 9:30, 11:30, 13:30, 15:30, 17:30, and 19:30 hr. The administration of dexamethasone resulted in an overall lengthening of sleep latency. Although the two groups displayed comparable latencies to stage 1 for the 23:00–7:30 hr nap opportunities, the administration of dexamethasone resulted in significantly longer latencies on the 9:30–19:30 hr nap opportunities. Consistent with these results, participants reported significantly greater levels of alertness on the Stanford Sleepiness Scale. The results of this study revealed greater levels of daytime alertness following the nocturnal administration of dexamethasone.

Notes: We present boron isotope and concentration data from magmatic (komatiitic to rhyolitic) and sedimentary geological silicate and artificial glass reference materials that cover a wide spectrum of boron isotope compositions and boron concentrations. Boron isotope compositions were determined by TIMS (Cs2BO2+ -graphite and BO2- method) and boron concentrations by ICP-AES. Boron concentrations ranged from 7 to 159μ g-1 and agree within 14% with published values. Based on replicate analyses of individually prepared sample aliquots an overall external reproducibility of better than 10% was determined. The obtained δ11B values ranged from -12.6 to +13.6% and were reproducible within 1.1 % (2 RSD; excluding NTIMS) on the basis of individually prepared sample aliquots. The δ11B values of JA-1 (+5.3%), JB-3 (+5.9%) and JR-2 (+2.9%) overlap the published data within analytical uncertainty. For the first time δ11B values for the TB (-12.6%) and the MPI-DING glasses GOR-128-G (+13.6%), GOR-132-G (+7.1 %) and StHs6/80-G (-4.5%) are reported. The δ11B values obtained by the Cs2BO2+ -graphite and the BO2- method as well as the majority of δ11B values obtained using different sample preparation methods agree within analytical uncertainty. Therefore, we conclude that none of these analytical methods introduce any systematic error on the obtained δ11B values.

Notes: Gastric cancer is one of the most frequent neoplasms and a leading cause of the death world-wide. In recent years, epidemiological and animal studies demonstrated a link between gastric cancer and chronic infection with H. pylori. The exact mechanism responsible for the development of gastric cancer in H. pylori-infected patients still remains unclear. There is evidence that the up-regulation of certain growth factors could play an important role in the promotion of the gastric carcinogenesis.〈section xml:id="abs1-2"〉〈title type="main"〉Aims:The present study was designed to determine the gene expression of major known growth factors such as transforming growth factor alpha (TGFα), hepatocyte growth factor (HGF) and gastrin in the gastric cancer tissue, the surrounding mucosa and, for comparison, in the normal gastric mucosa. Furthermore, the luminal and plasma levels of gastrin in patients with gastric cancer were determined. In addition, the gene and protein expressions of apoptosis-related proteins such as Bax and Bcl-2 were investigated by reverse transcription-polymerase chain reaction and Western blot. Twenty-five gastric cancer patients and 40 age- and gender-matched control subjects hospitalized with non-ulcer dyspepsia were included into this study.〈section xml:id="abs1-3"〉〈title type="main"〉Results:An overall H. pylori-seropositivity among gastric cancer patients was about 72% and was significantly higher than in the controls (56%). The prevalence of CagA-positive strains was also significantly higher among gastric cancer patients than in controls (56% vs. 32%). The gene expression of HGF and TGFα was detected more frequently in gastric cancer tissue samples than in normal gastric mucosa (52% vs. 12% for HGF and 48% vs. 24% for TGFα). The extent of protein expression in Western blotting analysis for HGF and TGFα correlated with the mRNA expression of these factors. Gene expression of gastrin was detected in the antrum of all tested patients and in the majority (84%) of gastric cancer patients. The median plasma and luminal concentrations of gastrin in gastric cancer patients were significantly higher than in controls. The gene expression of bcl-2 was detected in all (100%) and that of proapoptotic bax only in 56% of gastric cancer samples. In comparison to the surrounding non-tumorous tisssue, the gene expression of bax was significantly down-regulated and the gene expression of bcl-2 was up-regulated in gastric cancer tissue. At the protein level, Bax was not detectable and Bcl-2 was seen in 80% of gastric cancer samples.〈section xml:id="abs1-4"〉〈title type="main"〉Conclusions:It is concluded that the patients infected with H. pylori, especially with CagA-positive strains, are at a higher risk of developing a gastric cancer. An increased production and release of gastrin, as well as an over-expression of growth factors such as HGF and TGFα, might contribute to the gastric carcinogenesis. In addition, a dysregulation of the Bax/Bcl-2 system with significant up-regulation of Bcl-2 is observed in gastric cancer.

Notes: Background After exposure, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) is excreted via the faeces, breast milk and epidermal lipids. Objectives To determine to what extent TCDD is eliminated via the skin and to evaluate whether cutaneous elimination can be accelerated by the application of petrolatum. Methods In two patients severely intoxicated with TCDD, material obtained from the skin surface and, in one patient, cerumen and the content of epithelial cysts, was analysed for TCDD. Results The TCDD concentration in the initial blood sample taken was 144 000 pg g−1 blood fat in patient 1, and 26 000 pg g−1 blood fat in patient 2. Six months later, when the skin tests were performed, the blood TCDD levels had decreased to 80 900 and 16 100 pg g−1 blood fat, respectively. In the two samples of pooled cyst contents from patient 1, TCDD levels of 34 400 and 18 600 pg g−1 fat were found. A cerumen sample contained TCDD at 20 500 pg g−1 fat. In the material collected from the skin surface we observed a linear increase of the amount of TCDD measured per test field with time, indicating a continuous elimination of TCDD via the skin. The daily amount of TCDD eliminated via the skin was 1·51 pg cm−2 in patient 1 and 0·57 pg cm−2 in patient 2. Application of petrolatum led to a twofold increase in the amount of TCDD measured in patient 1, but had no significant effect in patient 2. Conclusions In our patients, elimination of TCDD via the skin, most probably through desquamating scales, represented 1–2% of the overall daily TCDD elimination rate, with regard to the body surface and when calculated on the basis of the half-life of TCDD at the time of the skin test. If a more typical overall elimination half-life of 7 years is used as the basis for the calculation, the skin would account for 9%(patient 1) and 15%(patient 2) of the overall elimination. Although we observed an increase in TCDD in material derived from the skin surface of up to 100% after application of petrolatum in patient 1, such an approach appears not to be a feasible means to increase elimination. Owing to the small amount of TCDD measured in skin-surface material, as well as in the cyst contents and cerumen obtained from one patient, contamination of the environment and other persons appears highly unlikely.