Reduced marine phytoplankton sulphur emissions in the Southern Ocean during the past seven glacials.

Marine biogenic sulphur affects Earth's radiation budget and may be an indicator of primary productivity in the Southern Ocean, which is closely related to atmospheric CO2 variability through the biological pump. Previous ice-core studies in Antarctica show little climate dependence of marine biogenic sulphur emissions and hence primary productivity, contradictory to marine sediment records. Here we present new 720,000-year ice core records from Dome Fuji in East Antarctica and show that a large portion of non-sea-salt sulphate, which was traditionally used as a proxy for marine biogenic sulphate, likely originates from terrestrial dust during glacials. By correcting for this, we make a revised calculation of biogenic sulphate and find that its flux is reduced in glacial periods. Our results suggest reduced dimethylsulphide emissions in the Antarctic Zone of the Southern Ocean during glacials and provide new evidence for the coupling between climate and the Southern Ocean sulphur cycle.

First Measurement of a Long-Lived π

The adapted DIRAC experiment at the CERN PS accelerator observed for the first time long-lived hydrogenlike π^{+}π^{-} atoms, produced by protons hitting a beryllium target. A part of these atoms crossed the gap of 96 mm between the target and a 2.1 µm thick platinum foil, in which most of them dissociated. Analyzing the observed number of atomic pairs, n_{A}^{L}=436_{-61}^{+157}|_{tot}, the lifetime of the 2p state is found to be τ_{2p}=(0.45_{-0.30}^{+1.08}|_{tot})×10^{-11} s, not contradicting the corresponding QED 2p state lifetime τ_{2p}^{QED}=1.17×10^{-11} s. This lifetime value is three orders of magnitude larger than our previously measured value of the π^{+}π^{-} atom ground state lifetime τ=(3.15_{-0.26}^{+0.28}|_{tot})×10^{-15} s. Further studies of long-lived π^{+}π^{-} atoms will allow us to measure energy differences between p and s atomic states and so to discriminate between the isoscalar and isotensor ππ scattering lengths with the aim to check QCD predictions.

Observation of π

The observation of hydrogenlike πK atoms, consisting of π^{-}K^{+} or π^{+}K^{-} mesons, is presented. The atoms are produced by 24 GeV/c protons from the CERN PS accelerator, interacting with platinum or nickel foil targets. The breakup (ionization) of πK atoms in the same targets yields characteristic πK pairs, called "atomic pairs," with small relative momenta Q in the pair center-of-mass system. The upgraded DIRAC experiment observed 349±62 such atomic πK pairs, corresponding to a signal of 5.6 standard deviations. This is the first statistically significant observation of the strange dimesonic πK atom.

SETBP1 mutations drive leukemic transformation in ASXL1-mutated MDS.

Mutations in ASXL1 are frequent in patients with myelodysplastic syndrome (MDS) and are associated with adverse survival, yet the molecular pathogenesis of ASXL1 mutations (ASXL1-MT) is not fully understood. Recently, it has been found that deletion of Asxl1 or expression of C-terminal-truncating ASXL1-MTs inhibit myeloid differentiation and induce MDS-like disease in mice. Here, we find that SET-binding protein 1 (SETBP1) mutations (SETBP1-MT) are enriched among ASXL1-mutated MDS patients and associated with increased incidence of leukemic transformation, as well as shorter survival, suggesting that SETBP1-MT play a critical role in leukemic transformation of MDS. We identify that SETBP1-MT inhibit ubiquitination and subsequent degradation of SETBP1, resulting in increased expression. Expression of SETBP1-MT, in turn, inhibited protein phosphatase 2A activity, leading to Akt activation and enhanced expression of posterior Hoxa genes in ASXL1-mutant cells. Biologically, SETBP1-MT augmented ASXL1-MT-induced differentiation block, inhibited apoptosis and enhanced myeloid colony output. SETBP1-MT collaborated with ASXL1-MT in inducing acute myeloid leukemia in vivo. The combination of ASXL1-MT and SETBP1-MT activated a stem cell signature and repressed the tumor growth factor-ß signaling pathway, in contrast to the ASXL1-MT-induced MDS model. These data reveal that SETBP1-MT are critical drivers of ASXL1-mutated MDS and identify several deregulated pathways as potential therapeutic targets in high-risk MDS.

Pharmacological preconditioning with doxorubicin. Implications of heme oxygenase-1 induction in doxorubicin-induced hepatic injury in rats.

Heme oxygenase (HO) is the rate-limiting enzyme in the degradation of heme into biliverdin, carbon monoxide, and iron. HO-1, an inducible form, is thought to contribute to resistance to various types of oxidative stress. Doxorubicin (DOX) produces clinically useful responses in a variety of human cancers. We reported previously that prior administration of DOX ameliorated subsequent hepatic ischemia and reperfusion injury. The aim of this study was to examine whether this pharmacological preconditioning was useful for another type of hepatic injury induced by a non-surgical method. When a high dose of DOX (10 mg/kg body weight) was administered directly to rat liver via the portal vein, serum aspartate transaminase (AST) and alanine transaminase (ALT) levels increased markedly 24 hr after the injection. Under this condition, zinc-protoporphyrin IX, a specific inhibitor of HO-1, caused both serum AST and ALT levels to be elevated further. When a low dose of DOX (5 mg/kg body weight) was administered to rats via the tail vein as pharmacological preconditioning 3 days before the injection of a high dose of DOX via the portal vein, the levels of serum AST and ALT in rats clearly were improved as compared with rats without the preconditioning. Expression of HO-1 in the liver was confirmed 3 days after the administration of a low dose of DOX. In addition, prior administration of zinc-protoporphyrin IX abolished the effect of DOX preconditioning. Immunohistochemical analysis showed that the positive staining of HO-1 protein induced by a low dose of DOX was localized to histiocytes infiltrating periportal areas. These results strongly suggest that pharmacological preconditioning with DOX may generally help to attenuate subsequent oxidant-induced hepatic injury.

[Pneumonia caused by Nocardia nova].

This is the first clinical report of a case of pneumonia caused by Nocardia nova in Japan. A 52 year-old woman who had received steroids and cyclophosphamide for six years because of polymyositis was admitted to our hospital for further examination. On admission she had a mild cough, and her chest radiography and computed tomography revealed bilateral multiple nodules, some of which were cavitated. She developed a cough productive of yellow sputum and fever up to 38 degrees C. Examination of the sputum revealed a gram-positive branched organism and sputum cultures repeatedly grew Nocardia species. The isolate was identified as Nocardia nova later. Clinical recovery was obtained readily upon treatment with imipenem and trimethoprim methoxazole, though the latter drug was discontinued because of nausea and anorexia. This drug was therefore replaced with oral minocycline, which proved to be ineffective clinically although susceptibility testing of the drug showed positive sensitivity. Minocycline was replaced with clarithromycin, after which chest radiography and computed tomography showed almost total resolution of the infiltrates. Clarithromycin may be an alternative oral agent to sulfonamides or minocycline when these agents are ineffective or not tolerated.

[A case of non-invasive pulmonary aspergillosis that rapidly deteriorated].

The pulmonary diseases caused by the Aspergillus species include invasive forms, for example, invasive pulmonary aspergillosis, chronic necrotizing pulmonary aspergillosis, and non-invasive pulmonary aspergillosis. Though these forms are defined pathologically by the presence of the Aspergillus species that invades the lung tissue, they are used as clinical entities. We report a case of non-invasive pulmonary aspergillosis which, from the clinical data, appeared likely to be misdiagnosed as the chronic invasive form. A 45 year-old man received chemoradiotherapy for lung cancer as well as undergoing an left upper lobectomy. Two weeks after the surgery the patient developed a cough, high fever and chest pain. Chest radiography and chest computed tomography showed a rapidly enlarging cavity with an internal mass and infiltration in the left lower lung field. A transbronchial biopsy specimen of the cavity wall showed fungal hyphae. Bronchial washing culture grew Aspergillus fumigatus. Itraconazole and amphotericin B were administered, but the patient's condition did not improve. A left lower lobectomy was performed. The histologic findings showed that the fungal hyphae were only on the surface of the cavity wall, and were surrounded by necrosis and widespread inflammatory cell infiltration. No fungal invasion of the viable lung tissue was seen. The area of infiltration revealed an organizing pneumonia without Aspergillus or other organisms. Our final diagnosis was non-invasive pulmonary aspergillosis. There has been no recurrence of the lung cancer or of the pulmonary aspergillosis in the three years since surgery. It is reported that non-invasive pulmonary aspergillosis passes through a period so active that it seems to be the invasive form for its entire clinical course. To avoid confusion in diagnosis, establishment of a comprehensive clinical classification of pulmonary aspergillosis will be needed.

Inhibition of expression of ornithine decarboxylase by c-myc antisense oligonucleotide at the promotion stage of lung tumorigenesis in mice.

Regulation of ornithine decarboxylase (ODC) expression at a promotion stage of lung carcinogenesis is a key clue to suppress the cancer. In this study, we investigated that the ODC induction at the promotion stage of lung carcinogenesis in mice could be inhibited through the suppression of the expression of c-myc, a transcription factor for ODC. The treatment with c-myc antisense oligonucleotide decreased the carcinogen-elevated level of pulmonary ODC protein at the promotion stage, but the sense oligonucleotide had no influence on the level. Overall, it is possible that the induction of ODC in the carcinogenic process of lung is regulated at its transcriptional level.

Hemin pretreatment ameliorates aspects of the nephropathy induced by mercuric chloride in the rat.

Mercuric chloride (HgCl(2)) is known to be a nephrotoxicant. When HgCl(2) is administered into rats, acute renal failure (ARF) is induced. Heme oxygenase-1 (HO-1) is antioxidative enzyme and is known to play a protective role against the oxidative injury. To elucidate the cytoprotective role of HO-1 against the nephrotoxicant-induced ARF, we examined the effect of hemin, HO-1 inducer, on HgCl(2)-induced ARF. Subcutaneous administration of hemin (30 mg/kg body weight) into rats once a day for two successive days obviously induced HO-1 protein in the kidneys at 24 h after the last injection. Under this situation, when HgCl(2) (1 mg/kg body weight) was intraperitoneally injected into rats at 24 h after the last injection of hemin improved the serum creatinine (SCr) and blood urea nitrogen (BUN) levels, markers for renal injury, at 24 h after the HgCl(2) injection as compared with the control rats without hemin pretreatment (HgCl(2) treatment alone). This result was further confirmed by histopathological analysis. These findings strongly suggest that the preinduction of HO-1 ameliorates the subsequent HgCl(2)-induced acute renal injury.

Correlation between the expression of methionine adenosyltransferase and the stages of human colorectal carcinoma.

Methionine adenosyltransferase (MAT) catalyzes the synthesis of S-adenosylmethionine (AdoMet) from ATP and L-methionine. AdoMet is the major methyl donor in most transmethylation reactions in vivo, and it is also the propylamino donor in the biosynthesis of polyamines. In the present study, we assessed MAT activity in human colons with colorectal carcinoma and the values were compared with those of morphologically normal adjacent mucosa. Higher levels of MAT activity were observed in the colorectal carcinoma than in the normal colon. The ratio of MAT activity in tumor tissue versus normal tissue seemed to be correlated well will the stage of the colorectal tumor. Furthermore, immunoblot analysis showed that the high levels of MAT activity observed in colorectal carcinoma were due to the increased amounts of MAT protein. Immunohistochemical analysis revealed that MAT was most abundant in goblet cells, particularly in granules in the supranuclear area of these cells. In the colorectal carcinoma tissues, MAT was strongly stained in the cancerous cells and localized in granules in the supranuclear region. The results of this preliminary study suggest that determination of the relative ratio of MAT activity in both normal and tumor regions in human colorectal carcinoma could be a clinically useful tool for determining the stage of malignancy of colorectal carcinomas.

Doxorubicin preconditioning: a protection against rat hepatic ischemia-reperfusion injury.

Doxorubicin produces clinically useful responses in a variety of human cancers. However, the toxicity of doxorubicin has limited its usefulness. This side effect is mainly due to the doxorubicin-mediated free radical formation. Administration of doxorubicin (10 mg/kg body weight) to rats intravenously induces heme oxygenase-1 (HO-1) in the liver. The levels of HO-1 protein were first detected at 6 hours and peaked at about 18 to 24 hours after the injection. It is known that HO-1 plays a protective role against the oxidative injury. Therefore, we have examined the protective effect of doxorubicin preconditioning against the hepatic ischemia-reperfusion injury. Partial hepatic ischemia was produced in the left and medium lobes for 45 minutes followed by 120 minutes reperfusion. When low doses of doxorubicin (1 mg/kg body weight) was intravenously administered to rats 2 days before the ischemia, the serum alanine transaminase (ALT) levels in the preconditioning rat were clearly improved compared with those in the rat without preconditioning. Under this situation, zinc-protoporphyrin IX, a specific inhibitor of HO-1, was injected subcutaneously to rats at 3 and 16 hours before the ischemia, the ALT levels were not improved by doxorubicin preconditioning. Histopathologic examination also supported these results. Although the HO-1 protein level was fairly low 2 days after the doxorubicin administration, significant amounts of HO-1 protein were detected. Our results indicated that the induction of HO-1 played a protective role against hepatic ischemia-reperfusion injury and that doxorubicin preconditioning is more clinically useful than other preconditioning methods.

Regulation of methionine adenosyltransferase activity by the glutathione level in rat liver during ischemia-reperfusion.

Hepatic ischemia was induced by clamping the hepatic artery, portal vein, and bile duct. After 15 min of ischemia, the hepatic glutathione (GSH) content rapidly decreased. On the other hand, after the start of reperfusion, the hepatic GSH levels promptly increased and reached a peak at about 1 h, and thereafter decreased to a minimum level by 2 h. Under such conditions, we examined the changes in the methionine adenosyltransferase (MAT) activity in the liver. Though the time course of MAT activity was somewhat delayed compared with that of the hepatic GSH levels, both patterns were substantially similar during ischemia-reperfusion. In contrast to the changes in the MAT activity during ischemia-reperfusion, the levels of MAT protein were unchanged during these periods. When endogenous antioxidant coenzyme Q(10) (CoQ(10)) was administered to rats prior to ischemia, both the reduction in the MAT activity and hepatic GSH levels induced by ischemia-reperfusion were protected. Our findings suggest that CoQ(10) may posttranslationally regulate the MAT activity via the changes in the GSH level in the liver.

Characterization of CFTR expression in a human pulmonary mucoepidermoid carcinoma cell line, NCI-H292 cells.

The NCI-H292 cell, a human pulmonary mucoepidermoid carcinoma cell line, is commonly used for studying bacterial and viral infections of airway epithelial cells. Dysfunction of the cystic fibrosis transmembrane conductance regulator (CFTR) is the main cause of fetal lung infection in cystic fibrosis patients. In this study, we examined CFTR expression in NCI-H292 cells to determine whether NCI-H292 cells possess sufficient, normally functioning CFTR. The results of RT-PCR and Northern blotting analysis indicated that the CFTR gene expression level was much lower in NCI-H292 cells than in T84 cells. However, Western blotting analysis showed that protein expression in NCI-H292 cells was comparable to that in T84 cells. Furthermore, whole-cell and cell-attached patch clamp electrophysiological techniques indicated that the Cl- current induced by intracellular cAMP elevation in NCI-H292 cells was comparable to that in T84 cells. These findings suggest that NCI-H292 cells with a low level of CFTR gene expression possess enough functional CFTR to show a physiological response.

Activation of epidermal growth factor receptor in the early phase after renal ischemia-reperfusion in rat.

In order to estimate a regenerative response in the early phase after renal ischemia-reperfusion in rat, we examined the time course of the activation of epidermal growth factor receptor (EGFR) as a response of signal transduction pathway after 45 min ischemia in kidney. The activation of EGFR was observed 5-30 min after the start of reperfusion. Simultaneously, superoxide anion/hydrogen peroxide generated in the mitochondrial fraction was elevated during the same period. On the other hand, the level of EGF decreased in a time-dependent manner. These results suggested that superoxide anion/hydrogen peroxide generated during the ischemia-reperfusion other than EGF could act as an activator for the EGFR. In summary, the activation of EGFR is important as a regenerative response at an early stage after the start of reperfusion in ischemic kidney.

Activation of extracellular signal-regulated kinase in lung tissues of mice treated with carcinogen.

The activation of extracellular signal-regulated kinase (ERK) in lung tissues of mice, as determined by the appearance of phosphorylated form, was observed on day 30 after urethane injection, and the activation also occurred in urethane-induced lung tumors. Immunohistochemical analysis using anti-phosphorylated ERK antibody indicated that the active form of ERK localized in alveolar epithelial cells. Furthermore, we confirmed by immunoprecipitation and immunoblot analysis that other essential components of the ERK cascade, that is, Ras, Raf and MEK (known as ERK kinase) were activated. These results indicate that the activation of the ERK signal in alveolar epithelial cells at the early stage of urethane-induced lung carcinogenesis is an important factor to develop lung tumors.

Extracellular signal-regulated kinase mediates renal regeneration in rats with myoglobinuric acute renal injury.

In vitro data support that extracellular signal-regulated kinase (ERK) and c-Jun N-terminal kinase (JNK), members of mitogen-activated protein (MAP) kinases, mediate the signal transduction pathways responsible for the cell proliferation. However, in vivo role of these MAP kinases is poorly understood. Intramuscular injection of 50% glycerol solution induces acute renal failure in rats. This injury is known as a model of rhabdomyolysis in human. To investigate the molecular mechanism of the signaling pathway in this injury, we examined the role of ERK and JNK. After the glycerol injection JNK was rapidly and transiently activated at about 4 h, while the activation of ERK was gradually increased and the levels were sustained at least to 24 h. Next, we examined the expression of cell-cycle related proteins after the glycerol injection using Western blot analysis. The levels of proliferating cell nuclear antigen (PCNA) protein as a marker for cell proliferation were induced at 2 h and significantly increased to 24 h after the injection. In addition, cyclins D1, D2, and D3 as markers for G1 phase also increased with similar time courses. To examine whether activation of ERK and/or JNK are involved in the renal regeneration after the glycerol injection, we examined the effect of genistein, which is an inhibitor of tyrosine kinase, on the activation of ERK and JNK. Administration of genistein to rats with this injury decreased the activation of ERK, but not JNK. The induction of PCNA and cyclin D1 was also prevented by this treatment. In this condition, renal function was further worsened as compared to control rats. These results provide the first evidence that ERK may be involved in the repair process of renal tubules damaged by this injury.

Both positive and negative portal venous and hepatic arterial glucose gradients stimulate hepatic glucose uptake after the same amount of glucose is infused into the splanchnic bed in conscious dogs.

We studied the effects of both positive and negative portal venous and hepatic arterial glucose gradients on hepatic glucose uptake after the same amount of glucose was administered into the portal vein and/or hepatic artery. Studies were performed on eight unrestrained conscious dogs with catheters in the portal vein, hepatic vein, gastroduodenal artery, superior mesenteric vein, and femoral artery and Doppler flow probes on the portal vein and hepatic artery. Glucose was infused as follows: protocol 1, 55.6 micromol/kg/min into the portal vein for the first 90 minutes; protocol 2, 27.8 micromol/kg/min into both the portal vein and hepatic artery for the next 90 minutes; and protocol 3, 55.6 micromol/kg/min into the hepatic artery for the last 90 minutes. The portal venous and hepatic arterial plasma glucose gradient was 2.1+/-0.3, -3.0+/-0.5, and -7.1+/-0.6 mmol/L, the rate of hepatic glucose uptake divided by the administered glucose load was 46%+/-11%, 42%+/-10%, and 57%+/-8%, net hepatic glucose uptake was 25.4+/-5.9, 23.5+/-5.6, and 31.6+/-4.6 micromol/kg/min; and the fractional hepatic extraction of glucose was 10.7%+/-2.2%, 11.6%+/-2.5%, and 15.0%+/-2.1%, respectively (mean+/-SEM of three points at 60, 75, and 90 minutes in each protocol). The rate of hepatic glucose uptake divided by the administered glucose load, net hepatic glucose uptake, and fractional hepatic extraction of glucose did not change significantly despite the various portal venous and hepatic arterial glucose gradients. We also studied the effect of the same amount of intraportal glucose infusion for 240 minutes on net hepatic glucose uptake. From 60 to 240 minutes, net hepatic glucose uptake did not change significantly. In conclusion, the liver took up a large amount of glucose administered into the portal vein and/or hepatic artery, regardless of positive or negative portal venous and hepatic arterial glucose gradients. Augmentation of hepatic glucose uptake is not dependent on the signal of the positive or negative portal venous and hepatic arterial glucose gradient.