Expression of RAB27B is up-regulated in senescent human cells

Immortal SVts8 cells that express thermolabile SV40 T antigen exhibit a senescence-like phenomenon upon inactivation of the T antigen. By using a cDNA subtractive hybridization technique, RAB27B, a member of the RAB GTPase family, was found to be up-regulated in senescent SVts8 cells. The up-regulation of RAB27B depends on the p53 gene. Enhanced expression was also observed in replicative senescence in normal human fibroblasts.     

Airway cytokine expression measured by means of protein array in exhaled breath condensate: correlation with physiologic properties in asthmatic patients

BACKGROUND: Simultaneous monitoring of airway inflammation and physiology might be useful for asthma management. OBJECTIVE: We examined the upregulated molecules in asthmatic airways. Furthermore, we investigated the relationship between these molecules and the airway physiologic properties of asthma. METHODS: Ten nonsmoking healthy subjects and 16 steroid-naive asthmatic patients were enrolled. Exhaled breath condensate (EBC) sampling, spirometry, and methacholine inhalation challenge were performed on one occasion in this cross-sectional study. Peak expiratory flow was also measured for 4 weeks. Airway cytokine-chemokine-growth factor production was analyzed with a protein array. RESULTS: The expressions of IL-4, IL-8, IL-17, TNF-alpha, RANTES, IFN-gamma-inducible protein 10, TGF-beta, and macrophage inflammatory protein 1alpha and 1beta were significantly upregulated in asthmatic airways compared with those of nonsmoking healthy subjects. Among the upregulated molecules, RANTES expression was significantly correlated with the parameters that represent airway caliber, FEV(1) and respiratory resistance values. In addition, the levels of both TNF-alpha and TGF-beta were significantly correlated with the methacholine threshold and peak expiratory flow variability for the week. CONCLUSION: Inflammatory molecule analysis with EBC appeared to be useful for monitoring the asthmatic airway condition. CLINICAL IMPLICATIONS: Measurements of cytokine levels in EBC might be a promising approach to assess the efficacy of pharmacologic interventions and to investigate the pathophysiology of asthma.     

Two modes of microtubule sliding driven by cytoplasmic dynein

Dynein is a huge multisubunit microtubule (MT)-based motor, whose motor domain resides in the heavy chain. The heavy chain comprises a ring of six AAA (ATPases associated with diverse cellular activities) modules with two slender protruding domains, the tail and stalk. It has been proposed that during the ATP hydrolysis cycle, this tail domain swings against the AAA ring as a lever arm to generate the power stroke. However, there is currently no direct evidence to support the model that the tail swing is tightly linked to dynein motility. To address the question of whether the power stroke of the tail drives MT sliding, we devised an in vitro motility assay using genetically biotinylated cytoplasmic dyneins anchored on a glass surface in the desired orientation with a biotin-streptavidin linkage. Assays on the dyneins with the site-directed biotin tag at eight different locations provided evidence that robust MT sliding is driven by the power stroke of the tail. Furthermore, the assays revealed slow MT sliding independent of dynein orientation on the glass surface, which is mechanically distinct from the sliding driven by the power stroke of the tail.     

A case of HHV-6 associated acute necrotizing encephalopathy with increase of CD56bright NKcells

We describe a 15-month-old girl with acute necrotizing encephalopathy (ANE) associated with HHV-6. Inflammatory cytokines were elevated in the CSF and serum and the number of CD56bright NK cells was significantly increased in the peripheral blood. CD56bright NK cells may be involved in the pathogenesis of ANE by producing inflammatory cytokines.     

Possible vascular role of increased plasma arginine vasopressin in congestive heart failure

BACKGROUND: The present study was undertaken to determine the relation of cardiac dysfunction with hormonal release in patients with congestive heart failure. METHODS: Seventy-two patients with congestive heart failure were examined, who were divided into four subgroups classified by the criteria of the New York Heart Association (NYHA). Also, 10 age-matched subjects were served as a control. Plasma arginine vasopressin (AVP), norepinephrine, atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) were determined. Cardiac index and pulmonary capillary wedge pressure (PCWP) were measured in 51 of 72 patients. RESULTS: Plasma AVP levels were significantly increased according to the severity of NYHA classes; control: 1.7 +/- 0.2; NYHA I: 4.9 +/- 0.8, NYHA II: 5.5 +/- 0.9, NYHA III: 13.4 +/- 2.6 (p < 0.05), NYHA IV: 26.9 +/- 5.6 pmol/l (p < 0.001). Similar results were obtained with plasma norepinephrine, ANP and BNP. Plasma AVP levels had negative correlation with cardiac index (r = -0.36, p < 0.01), but did not with PCWP and plasma osmolality. Plasma BNP levels positively correlated with PCWP (r = 0.44, p < 0.001), but did not with cardiac index. There was no correlation between plasma AVP and BNP. Intensive therapy profoundly reduced all the hormones according to the improvement of cardiac index in the patients with NYHA class III and IV. The percent decrease in plasma AVP was 60.0%, a value greater than that in plasma BNP. CONCLUSION: The present study indicates that increased AVP may deteriorate cardiac function through V(1a) as well as V(2) action, and that plasma AVP level is also a proper marker for the presence and severity of congestive heart failure.     

Noninvasive assessment of coronary stents in patients by 16-slice computed tomography

BACKGROUND: The usefulness of thin-slice multi-detector computed tomography (MDCT) has been highly expected to assess the lumens of coronary artery stents. We evaluated the usefulness of 16-slice MDCT to assess the in-stent lumen after coronary artery stenting. METHODS: In 42 consecutive patients after coronary artery stenting, retrospective ECG-gated CT-angiography using 16-slice MDCT (0.5-s rotation time, 16x0.625-mm detector collimation) was performed. The qualitative assessability of the lumens of 61 coronary stents (14 different types) by MDCT and the reasons for non-assessability were investigated. Furthermore, the evaluation of in-stent restenosis in 21 assessable stents of 16 patients, including quantitative density analysis by MDCT, was performed and the results were compared with those of conventional coronary angiography (CAG). RESULTS: Of 61 stents, 42 (68.9%) were assessable. The assessability of diameter > or =3.5-mm stents made of stainless steel or cobalt was high (88.6%, 31/35), that of 3.0-mm stents was low (57.9%, 11/19) and all 2.5-mm stents were non-assessable due to partial volume effects and metal artifacts of stents. The lumens of stents made of tantalum were totally obscured and the metal artifacts of Bestent2 (gold markers) and S670 were severer than others. All non-assessable stents due to banding artifact and calcification were implanted in segment #1-3 and #6, respectively. In comparison to CAG, MDCT correctly detected the 5 in-stent restenoses and identified absence of restenoses was influenced strongly by the stent strut. CONCLUSION: Despite some limitations, 16-slice MSCT is sufficiently useful for assessment of various coronary stents in patients and can detect in-stent restenoses of assessable stents with high accuracy in comparison to CAG.     

Mutagenic potentials of Amberlite XAD-2-resin extracts obtained from river and drinking waters in the Northwest district of Chiba, Japan

Amberlite XAD-2 resin extracts of river and drinking water sampled from the Northwest district of Chiba Prefecture in each month during the period from January to December 2008 were investigated to characterize and determine their mutagenic potentials and polycyclic aromatic hydrocarbon (PAH) levels. The extracts from the river water were shown to be mutagenic in Salmonella typhimurium TA98 (a flameshift mutagen) without S9 mix, with higher mutagenic responses in summer and early fall seasons. While the drinking water extracts exhibited weak mutagenicity in both the TA98 and TA100 strains (a base-pair substitution mutagen) without S9 mix, with high mutagenic responses in fall and early winter seasons. GC/MS determinations of the water concentrates showed some seasonal scatter in PAH levels in river water. In contrast, comparatively high concentrations of PAHs were observed for drinking water samples collected during warmer seasons. Statistical studies revealed that there is a lower correlation between the levels of flameshift mutagenicity and the concentrations of PAH in the river water concentrations, but a higher correlation between them in the drinking water samples.     

Low micromolar zinc exerts cytotoxic action under H2O2-induced oxidative stress: Excessive increase in intracellular Zn concentration

The ability of zinc to retard oxidative processes has been recognized for many years. However, zinc is cytotoxic under certain oxidative stress. In this study, we investigated the effect of H₂O₂ on intracellular Zn²⁺ concentration of rat thymocytes and its relation to the cytotoxicity. Experiments were cytometrically performed by the use of fluorescent probes, propidium iodide, FluoZin-3-AM, and 5-chloromethylfluorescein diacetate. ZnCl₂ potentiated cytotoxicity of H₂O₂ while TPEN, a chelator for intracellular Zn²⁺, attenuated it. Results suggested an involvement of intracellular Zn²⁺ in the cytotoxicity of H₂O₂. H₂O₂ at concentrations of 30 μM or more (up to 1000 μM) significantly increased intracellular Zn²⁺ concentration. There were two mechanisms. (1) H₂O₂ decreased cellular content of nonprotein thiols, possibly resulting in release of Zn²⁺ from thiols as cellular Zn²⁺ binding sites. (2) H₂O₂ increased membrane Zn²⁺ permeability because external ZnCl₂ application further elevated intracellular Zn²⁺ concentration. Micromolar H₂O₂ may induce excessive elevation of intracellular Zn²⁺ concentration that is harmful to cellular functions. However, the incubation with micromolar ZnCl₂ alone increased cellular content of nonprotein thiols, one of the factors protecting cells against oxidative stress. Though zinc is generally considered to be protective with its antioxidant property, this study reveals the toxic effect of zinc even in micromolar range under oxidative stress induced by H₂O₂.     

Surgical treatment for isolated inguinal lymph node metastasis in lower rectal adenocarcinoma patients improves outcome

Purpose

No consensus has been formed on the optimal treatment strategy for the prognosis of patients with inguinal lymph node (ILN) metastasis from lower rectal adenocarcinoma. We, therefore, retrospectively analyzed outcomes of patients with ILN metastasis from lower rectal adenocarcinoma.

Methods

Of 323 patients with lower rectal adenocarcinoma treated at a single institution between November 1993 and March 2010, 10 had synchronous or metachronous ILN metastasis, as confirmed by curative resection (R0) of the primary lesion. Outcomes of these 10 patients were assessed.

Results

The 10 patients with ILN metastasis were divided into two groups: group A (two patients who did not undergo ILN resection surgery because of metastases at other sites) and group B (eight patients with no other metastases who underwent surgery). Both patients in group A, with median overall survival of 5.2 months, died due to the other metastases, whereas five out of eight patients in group B survived (P?=?0.001). Group B patients were further subclassified into synchronous (group B1) and metachronous (group B2) metastasis (n?=?4 each) groups. Two patients in group B1 died of other metastases, which was diagnosed later, whereas three patients in group B2 survived.

Conclusions

Some patients with isolated inguinal lymph node metastasis show a good prognosis after lymph node excision and, therefore, should be treated surgically. Patients with metachronous metastases have a better prognosis than patients with synchronous ILN metastases. Nevertheless, assessment of additional patients for prognosis and treatment strategy is warranted.     

Increased hepatic oxidative DNA damage in patients with nonalcoholic steatohepatitis who develop hepatocellular carcinoma

Background

The rate of onset of hepatocellular carcinoma (HCC) in patients with nonalcoholic steatohepatitis (NASH) has been reported recently to be comparable to that of patients with chronic hepatitis C. However, the precise mechanism contributing to carcinogenesis in the former remains unclear. Although increased oxidative stress is presumed to play a role in carcinogenesis in patients with NASH, this relationship remains to be directly proven. In this study, we investigated the involvement of oxidative DNA damage in hepatocarcinogenesis in patients with NASH.

Methods

Patients with nonalcoholic fatty liver disease who were treated at our university hospital were eligible for enrolment in the study(n = 49). The study cohort included 30 patients with NASH without HCC (NASH without HCC), six HCC patients with NASH (NASH–HCC), and 13 patients with simple steatosis. Quantitative immunohistochemistry with a KS-400 image analyzing system was used for 8-hydroxy-2′-deoxyguanosine (8-OHdG) detection.

Results

The 8-OHdG content in the liver tissue of NASH–HCC patients was significantly different from that in the other patients. The median immunostaining intensity was 8.605 in the NASH–HCC cases, which was significantly higher than that in the cases of NASH without HCC (4.845; P = 0.003). Multivariate analysis using hepatic 8-OHdG content as a factor in addition to age and fasting blood sugar revealed a significant difference in clinicopathological factors between NASH–HCC and NASH without HCC cases. Old age (P = 0.015) and high relative immunostaining intensity for intrahepatic 8-OHdG (P = 0.037) were identified as independent factors.

Conclusions

8-OHdG content in liver tissue may serve a marker of oxidative stress and could be a particularly useful predictor of hepatocarcinogenesis.