Chronic hypoxia accelerates the progression of atherosclerosis in apolipoprotein E-knockout mice.

The aim of this study was to investigate the effect of chronic hypoxia on the development and progression of atherosclerosis in apolipoprotein E-knockout (apoE-KO) mice. Male and female apoE-KO mice (6 weeks old) and age- and sex-matched wild-type mice were kept under hypoxic conditions (10.0 +/- 0.5% O2) in a gas chamber or in room air for 3 weeks. Aortic atherosclerotic plaque was not observed in wild-type mice under normoxic or hypoxic conditions. In the apoE-KO mice, however, hypoxia induced proliferation of smooth muscle cells and plaque formation in the aorta, which were not observed under normoxic conditions. Although sexual dimorphism of the response to hypoxia was not observed, these hypoxia-induced atherogenic changes were accompanied by a significant increase of plasma low density lipoprotein (LDL) cholesterol and NADPH-dependent vascular superoxide (O2-) production. Furthermore, matrix metalloproteinase (MMP)-9 was activated in the aorta of apoE-KO mice. In conclusion, chronic hypoxia accelerated the development of atherosclerosis in apoE-KO mice, along with increased O2- production and activated MMP-9 in the aorta.     

Changing trends in the proportion of adenocarcinoma of the esophagogastric junction in a large tertiary referral center in Japan

Introduction: A dramatic increase in incidence of adenocarcinoma of the esophagogastric junction (EGJ) over the past two decades has been reported in the West. However, epidemiological data from Asian countries have not shown a similar trend. The aim of this study was to determine the incidence of adenocarcinoma of the EGJ in a cohort of consecutive patients operated on for gastric adenocarcinoma at a major cancer referral center in Japan. Method: We reviewed pathological reports of all patients who underwent surgery for advanced gastric adenocarcinoma between 1962 and 2005 at the National Cancer Centre Hospital in Tokyo. Adenocarcinoma of the EGJ was defined from images recorded for each patient, in accordance with the classification of Siewert and Stein. The proportion of adenocarcinoma at the EGJ among operated gastric adenocarcinoma patients was compiled at five‐year intervals and serial comparison made. Results: A total of 6953 patients with advanced gastric adenocarcinoma were operated on; adenocarcinoma of EGJ was found in 520 patients. The overall proportion of adenocarcinoma of the EGJ increased from 2.3% (1962–1965) to 10.0% (2001–2005). The proportion of Siewert Type II rose from 28.5% (1962–1965) to 57.3% (2001–2005), while that of Type I remained at around 1%. Conclusion: An increasing trend of adenocarcinoma of EGJ is observed in this study of patients operated on for gastric adenocarcinoma from 1962 to 2005 in a large tertiary referral center in Japan.     

Neocerebellar hypoplasia with systemic combined olivo-ponto-dentatal degeneration in a 9-day-old baby: contribution to the problem of relations between malformation and systemic degeneration in early life

Three different cerebral alterations, apparently formed consecutively, were observed in a 9-day-old baby. Marked cortico-neocerebellar hypoplasia was seen in a relatively well-developed paleocortex. Its teratological stage was apparently the 3rd fetal month. Almost total nerve cell loss and marked proliferation of protoplasmic and fibrous astrocytes were found in the nuclei pontis and inferior olive. Perihypoglossal and pararaphal nuclei, which are related to the cerebellum, were also affected. This degenerative process must have resulted from neuronal deprivation or inactivity, as the pertinent cortico-cerebellar area was hypoplastic, and therefore any neuronal imput was impossible (olivo-ponto-dentatal degeneration due to cortico-cerebellar hypoplasia). Massive symmetrical necrosis in the cerebral white and grey matter, basal ganglia, midbrain and bulbus, is interpreted as hypoxic damage due to perinatal convulsive attacks and cessation of respiration.     

Essential role of IRAK-4 protein and its kinase activity in Toll-like receptor-mediated immune responses but not in TCR signaling

Interleukin-1 receptor-associated kinase 4 (IRAK-4) was reported to be essential for the Toll-like receptor (TLR)- and T cell receptor (TCR)-mediated signaling leading to the activation of nuclear factor kappaB (NF-kappaB). However, the importance of kinase activity of IRAK family members is unclear. In this study, we investigated the functional role of IRAK-4 activity in vivo by generating mice carrying a knockin mutation (KK213AA) that abrogates its kinase activity. IRAK-4(KN/KN) mice were highly resistant to TLR-induced shock response. The cytokine production in response to TLR ligands was severely impaired in IRAK-4(KN/KN) as well as IRAK-4(-/-) macrophages. The IRAK-4 activity was essential for the activation of signaling pathways leading to mitogen-activated protein kinases. TLR-induced IRAK-4/IRAK-1-dependent and -independent pathways were involved in early induction of NF-kappaB-regulated genes in response to TLR ligands such as tumor necrosis factor alpha and IkappaBzeta. In contrast to a previous paper (Suzuki, N., S. Suzuki, D.G. Millar, M. Unno, H. Hara, T. Calzascia, S. Yamasaki, T. Yokosuka, N.J. Chen, A.R. Elford, et al. 2006. Science. 311:1927-1932), the TCR signaling was not impaired in IRAK-4(-/-) and IRAK-4(KN/KN) mice. Thus, the kinase activity of IRAK-4 is essential for the regulation of TLR-mediated innate immune responses.     

Effect of plaunotol in combination with clarithromycin or amoxicillin on Helicobacter pylori in vitro and in vivo

Plaunotol, a cytoprotective anti-ulcer agent, has antibacterial activity against Helicobacter pylori. The purpose of the present study was to investigate the effect of plaunotol when combined with clarithromycin or amoxicillin against H. pylori. When combined with clarithromycin, plaunotol showed synergic activity against 11 of 14 strains, and additive activity against the other three strains, by chequerboard titration. When combined with amoxicillin, plaunotol showed additive activity against 10 of 14 strains. No antagonistic effects were seen against any of the strains tested. The interactions between plaunotol and either clarithromycin or amoxicillin were determined by time-kill assay against the Sydney Strain (strain SS1) of H. pylori. The combination of plaunotol with clarithromycin showed synergic activity and with amoxicillin showed additive activity. In a C57BL/6 mouse gastritis model infected with H. pylori SS1, the plaunotol-clarithromycin and plaunotol-amoxicillin combinations both exhibited synergic effects, which allowed the effective dose of clarithromycin to be reduced when co-administered with plaunotol. These results suggest that plaunotol may have a useful role in combination with anti-H. pylori drugs in the treatment of H. pylori-associated diseases.