Central command does not decrease cardiac parasympathetic efferent nerve activity during spontaneous fictive motor activity in decerebrate cats

To examine whether withdrawal of cardiac vagal efferent nerve activity (CVNA) predominantly controls the tachycardia at the start of exercise, the responses of CVNA and cardiac sympathetic efferent nerve activity (CSNA) were directly assessed during fictive motor activity that occurred spontaneously in unanesthetized, decerebrate cats. CSNA abruptly increased by 71 ± 12% at the onset of the motor activity, preceding the tachycardia response. The increase in CSNA lasted for 4-5 s and returned to the baseline, even though the motor activity was not ended. The increase of 6 ± 1 beats/min in heart rate appeared with the same time course of the increase in CSNA. In contrast, CVNA never decreased but increased throughout the motor activity, in parallel with a rise in mean arterial blood pressure (MAP). The peak increase in CVNA was 37 ± 9% at 5 s after the motor onset. The rise in MAP gradually developed to 21 ± 2 mmHg and was sustained throughout the spontaneous motor activity. Partial sinoaortic denervation (SAD) blunted the baroreflex sensitivity of the MAP-CSNA and MAP-CVNA relationship to 22-33% of the control. Although partial SAD blunted the initial increase in CSNA to 53% of the control, the increase in CSNA was sustained throughout the motor activity. In contrast, partial SAD almost abolished the increase in CVNA during the motor activity, despite the augmented elevation of 31 ± 1 mmHg in MAP. Because afferent inputs from both muscle receptors and arterial baroreceptors were absent or greatly attenuated in the partial SAD condition, only central command was operating during spontaneous fictive motor activity in decerebrate cats. Therefore, it is likely that central command causes activation of cardiac sympathetic outflow but does not produce withdrawal of cardiac parasympathetic outflow during spontaneous motor activity.     

Synthesis and biological evaluation of gambierol analogues

Gambierol is a polycyclic ether toxin, isolated as a toxic constituent from the marine dinoflagellate Gambierdiscus toxicus. We describe here the synthesis and biological evaluation of structural analogues of gambierol. The present preliminary structure-activity relationship studies clearly indicate that the H ring functionality and the unsaturated side chain of gambierol are crucial for its potent toxicity.     

Significant enhancement of lignan accumulation in hairy root cultures of Linum album using biotic elicitors

Linum album has been shown to accumulate some lignans with antiviral and anticancer properties such as podophyllotoxin (PTOX) and 6-methoxy podophyllotoxin (MPTOX). In this research, we examined the effects of fungal elicitors on the production of lignans in L. album hairy root cultures. The biosynthesis of lignans was differentially affected by fungal elicitors. Fusarium graminearum extract induced the highest increase of PTOX, 190 μg g^?1 dry weight (DW), and lariciresinol, 260 μg g^?1 DW, which was two-fold and three-fold greater than the untreated control, respectively, while Trichoderma viride extract enhanced the accumulation of MPTOX, instead of PTOX, up to 160 µg g^?1 DW, which was 2.4-fold greater than the control. The enhancing effects of fungal elicitors on lignans production was correlated with the increased expression of some key genes involved in the biosynthesis of these compounds, phenylalanine ammonia-lyase, cinnamoyl-CoA reductase, cinnamyl-alcohol dehydrogenase and pinoresinol-lariciresinol reductase.     

Predictive Factor of Local Recurrence after Balloon-Occluded TACE with Miriplatin (MPT) in Hepatocellular Carcinoma

Background

Miriplatin (MPT) is a novel platinum complex used in TACE that shows promise for the treatment of hepatocellular carcinoma (HCC). However, rapid washout has been reported in some cases. Therefore, various methods of administration with MPT have been attempted to increase its therapeutic efficacy. One hopeful method is balloon-occluded TACE (B-TACE), but the therapeutic efficacy of B-TACE with MPT has not been evaluated.

Aim

To investigate the treatment outcomes and factors involved in local recurrence after B-TACE with MPT in HCC.

Methods

This study included 51 patients (55 nodules) with HCC lesions equal or less than 5 cm in diameter who underwent B-TACE with MPT between January 2012 and June 2013. Local recurrence after B-TACE with MPT and factors associated with local recurrence were evaluated.

Results

The overall local recurrence rate was 11.1% at 6 months and 26.2% at 12 months. The local recurrence rate did differ significantly depending on CT values immediately after B-TACE with MPT. Multivariate analysis also showed that the CT value after B-TACE with MPT was the only factor related to local recurrence after B-TACE.

Conclusions

B-TACE with MPT achieves relatively good local control of HCC. The plain CT value immediately after B-TACE with MPT is a predictive factor for local recurrence. In patients with unsatisfactory CT values, locoregional therapy or additional treatment is required.     

Ribosomes in a Stacked Array: ELUCIDATION OF THE STEP IN TRANSLATION ELONGATION AT WHICH THEY ARE STALLED DURING S-ADENOSYL-l-METHIONINE-INDUCED TRANSLATION ARREST OF CGS1 mRNA*

Expression of CGS1, which codes for an enzyme of methionine biosynthesis, is feedback-regulated by mRNA degradation in response to S-adenosyl-l-methionine (AdoMet). In vitro studies revealed that AdoMet induces translation arrest at Ser-94, upon which several ribosomes stack behind the arrested one, and mRNA degradation occurs at multiple sites that presumably correspond to individual ribosomes in a stacked array. Despite the significant contribution of stacked ribosomes to inducing mRNA degradation, little is known about the ribosomes in the stacked array. Here, we assigned the peptidyl-tRNA species of the stacked second and third ribosomes to their respective codons and showed that they are arranged at nine-codon intervals behind the Ser-94 codon, indicating tight stacking. Puromycin reacts with peptidyl-tRNA in the P-site, releasing the nascent peptide as peptidyl-puromycin. This reaction is used to monitor the activity of the peptidyltransferase center (PTC) in arrested ribosomes. Puromycin reaction of peptidyl-tRNA on the AdoMet-arrested ribosome, which is stalled at the pre-translocation step, was slow. This limited reactivity can be attributed to the peptidyl-tRNA occupying the A-site at this step rather than to suppression of PTC activity. In contrast, puromycin reactions of peptidyl-tRNA with the stacked second and third ribosomes were slow but were not as slow as pre-translocation step ribosomes. We propose that the anticodon end of peptidyl-tRNA resides in the A-site of the stacked ribosomes and that the stacked ribosomes are stalled at an early step of translocation, possibly at the P/E hybrid state.     

Arf6 Guanine Nucleotide Exchange Factor Cytohesin-2 Binds to CCDC120 and Is Transported Along Neurites to Mediate Neurite Growth

The mechanism of neurite growth is complicated, involving continuous cytoskeletal rearrangement and vesicular trafficking. Cytohesin-2 is a guanine nucleotide exchange factor for Arf6, an Arf family molecular switch protein, controlling cell morphological changes such as neuritogenesis. Here, we show that cytohesin-2 binds to a protein with a previously unknown function, CCDC120, which contains three coiled-coil domains, and is transported along neurites in differentiating N1E-115 cells. Transfection of the small interfering RNA (siRNA) specific for CCDC120 into cells inhibits neurite growth and Arf6 activation. When neurites start to extend, vesicles containing CCDC120 and cytohesin-2 are transported in an anterograde manner rather than a retrograde one. As neurites continue extension, anterograde vesicle transport decreases. CCDC120 knockdown inhibits cytohesin-2 localization into vesicles containing CCDC120 and diffuses cytohesin-2 in cytoplasmic regions, illustrating that CCDC120 determines cytohesin-2 localization in growing neurites. Reintroduction of the wild type CCDC120 construct into cells transfected with CCDC120 siRNA reverses blunted neurite growth and Arf6 activity, whereas the cytohesin-2-binding CC1 region-deficient CCDC120 construct does not. Thus, cytohesin-2 is transported along neurites by vesicles containing CCDC120, and it mediates neurite growth. These results suggest a mechanism by which guanine nucleotide exchange factor for Arf6 is transported to mediate neurite growth.     

Aluminum in lake water and organs of a fish Tribolodon hakonensis in strongly acidic lakes with a high aluminum concentration

Aluminum in lake water and in the organs of the fish Tribolodon hakonensis was investigated in Lake Usoriko (pH 3.6), Lake Inawashiroko (pH 5.0), and the Tenryu River (pH 7.7). The concentration of total soluble aluminum in the water was 0.51 mg l⁻¹ in Usoriko, 0.05 mg l⁻¹ in Inawashiroko, and less than 0.01 mg l⁻¹ in the Tenryu. The chemical forms of soluble aluminum in the acid water were characterized as Al³⁺, AlL²⁺, and AlL^≦1+. More than 90% of soluble aluminum in the water of Usoriko was Al³⁺, whereas AlL²⁺ was dominant in the water of Inawashiroko. The aluminum concentration in the organs of T. hakonensis in Usoriko was 42 μg g⁻¹ wet weight in gills, 4.2 μg g⁻¹ in muscle, 6.9 μg g⁻¹ in bone, 12.7 μg g⁻¹ in liver, 6.0 μg g⁻¹ in kidney, and 6.0 μg g⁻¹ in intestine, indicating accumulation of aluminum in the gills. The aluminum concentration in the organs of T. hakonensis living in Inawashiroko was approximately the same, in spite of the difference in water chemistry of the two acid lakes, especially for pH and aluminum. This suggests that aluminum accumulation might be controlled in the fish living in the acid lakes. In contrast, the aluminum concentration in the gills of T. hakonensis from the Tenryu was 2 μg g⁻¹. Received: May 20, 1999 / Accepted: December 10, 1999     

Mechanism of aluminium tolerance in Cyanidium caldarium

Cyanidium caldarium, an acidophilic, thermophilic red alga, specifically tolerates Al. The tolerance increases at lower culture temperatures. The intracellular Al concentration is kept at low levels, especially when the cells are cultured at lower temperatures. Lower Al incorporation accounts for the Al tolerance in this alga. Fe incorporation antagonizes the Al incorporation, implying that Fe transporters incorporate Al ions. Treatment with an uncoupler, carbonylcyanide m-chlorophenylhydrazone, increases the intracellular concentration of Al. These results support the hypothesis that Al ions taken up by the algal cells are exported by an energy-dependent mechanism.     

Relationship between seasonal progression of floral meristem development and <Emphasis Type="Italic">FLOWERING LOCUS T</Emphasis> expression in the deciduous tree <Emphasis Type="Italic">Fagus crenata</Emphasis>

Estimating the timing of flower bud formation in plants is essential to identify environmental factors that regulate floral transition. The presence of winter dormancy between the initiation of flowers and anthesis, characteristic of most trees in the temperate forests, hampers accurate estimation of the timing of floral transition. To overcome this difficulty, expression levels of flowering-time genes could be used as indicators of the timing of floral transition. Here, we evaluated the usefulness of molecular markers in estimating the timing of floral transition in Fagus crenata, a deciduous tree that shows intermittent and synchronized flowering at the population level. We selected FLOWERING LOCUS T (FT) as a candidate molecular marker and quantified the expression levels of its ortholog in F. crenata (FcFT). Subsequently, we analyzed the relationship between morphogenetic changes that occur between the vegetative state of the buds and the initiation of floral organs, and compared the FcFT expression levels in reproductive and vegetative buds, collected from spring to autumn. FcFT expression in leaves peaked at least two weeks before the morphological changes associated with flowering were visible in the buds in late July. FcFT expression levels were significantly higher in the reproductive buds than in the vegetative buds in July. These results suggest that the FcFT expression in July is a reliable indicator of the timing and occurrence of floral transition. This study highlights the utility of molecular tools in unraveling reproductive dynamics in plants, in combination with ecological and physiological approaches.     

Impact of serine protease inhibitor alpha1-antitrypsin on expression of endoplasmic reticulum stress-induced proinflammatory factors in adipocytes

Obesity-induced endoplasmic reticulum (ER) stress contributes to low-grade chronic inflammation in adipose tissue and may cause metabolic disorders such as diabetes mellitus and dyslipidemia. Identification of high serpina A1 (alpha-1 antitrypsin, A1AT) expression in mouse adipose tissue and adipocytes prompted us to explore the role of A1AT in the inflammatory response of adipocytes under ER stress. We aimed to determine the role of A1AT expression in adipocytes with ER stress during regulation of adipocyte homeostasis and inflammation. To this end, we chemically induced ER stress in A1AT small interfering RNA-transfected differentiating adipocytes using thapsigargin. Induction of CCAAT-enhancer-binding protein homologous protein (CHOP), an ER stress marker, by thapsigargin was lower in A1AT-deficient SW872 adipocytes. Thapsigargin or the proinflammatory cytokine tumor necrosis factor (TNF)α increased basal expression of cytokines such as interleukin (IL)-1β and IL-8 in both SW872 and primary omental adipocytes. This thapsigargin- or TNFα-induced expression of proinflammatory genes was increased by A1AT deficiency. These findings indicate that adipose A1AT may suppress the ER stress response to block excessive expression of proinflammatory factors, which suggests that A1AT protects against adipose tissue dysfunction associated with ER stress activation.