严重水分失衡状态下四照花蒸腾表面的削减

应用RGB图像分析的方法,研究了日本山口市街区生长的四照花（Comus kousa Buerg.）对2007年夏季干热多风的环境的响应。结果表明,许多四照花叶尖叶缘出现焦枯,清晰的暗棕色防护带显示在焦枯的叶片上。这些防护带逐渐从叶尖向叶基退缩直到成功控制焦枯为止,且留下许多不成功的防卫痕迹。焦枯的叶片呈现鲜明的逻辑斯蒂函数式变化趋势。依据气象数据分析,四照花叶片退缩型焦枯几乎与干燥峰值期同步。这表明在干燥度突然升高期间,极端的水分亏缺诱发了四照花的防卫反应,从而保护其余部分免于进一步的失水。像素分析结果表明,截止到2007年8月底四照花样树通过局部叶片退缩型焦枯减少了40.2%的叶面积。相比之下,鉴于上半年雨量充足,2008年,相同的样树只有13.2%叶面积减少。不管怎样,四照花的确削减了蒸腾表面积,并且表现出一种独特的蒸腾表面减少方式。既不同于落叶也不同于地上部枯死。依据脱水过程的分析,四照花在突然的干热胁迫下叶尖始发的干缩和叶片防卫反应的共同作用被认为是其蒸腾表面削减的关键所在。     

Silicic acid: boric acid complexes as wood preservatives

Wood was treated with a low molecular-weight silicic acid: boric acid agent and examined for increased resistance to termites and combustion. Wood treated with silicic acid only exhibited increased termite resistance, but not to the marked extent observed after treatment with a mixture of silicic and boric acids. Increasing the quantity of boric acid also increased the termite mortality rate and shortened the time to death. Oral-toxicity tests using dyed silicic acid: boric acid suggested that the boric acid in the agent acted as a stomach poison. Field tests on stakes over three years showed that even if stakes were placed near the termite exit, those treated with silicic acid and high levels of boric acid had no attack by termites and maintained their original form. Though these specimens were installed in the field during three rainy seasons (about six months in total) in three years, the termite resistance ability of these chemicals was maintained. It became clear that this silicic acid: boric acid agent has a high water resistance ability worthy of application in the outdoors. Combustion tests showed that flame and glowing combustion times were shortened at high levels of boric acid. When a boric acid: methanol solution was added at of rate of not less than 25 ml for 100 g of colloidal silicic acid solution (CSAS), flaming and glowing combustion were not observed. Although the charring length of the wood specimen which was treated with a low molecular weight silicic acid: boric acid agent decreased to 2/3 of that of the control wood, the charring lengths were not influenced by the level of boric acid. However, the volume of smoke decreased relative to the amount of boric acid that had been added.     

Programmed Cell Death Induced by (?)-8,9-Dehydroneopeltolide in Human Promyelocytic Leukemia HL-60 Cells under Energy Stress Conditions

(+)-Neopeltolide is a marine macrolide natural product that exhibits potent antiproliferative activity against several human cancer cell lines. Previous study has established that this natural product primarily targets the complex III of the mitochondrial electron transport chain. However, the biochemical mode-of-actions of neopeltolide have not been investigated in detail. Here we report that (−)-8,9-dehydroneopeltolide (8,9-DNP), a more accessible synthetic analogue, shows potent cytotoxicity against human promyelocytic leukemia HL-60 cells preferentially under energy stress conditions. Nuclear morphology analysis, as well as DNA ladder assay, indicated that 8,9-DNP induced significant nuclear condensation/fragmentation and DNA fragmentation, and these events could be suppressed by preincubating the cells with a pan-caspase inhibitor, N-benzyloxycarbonyl-Val-Ala-Asp(OMe)-fluoromethylketone (zVAD). Immunoblot analysis demonstrated the release of cytochrome c from the mitochondria and the cleavage of full-length caspase-3 and poly(ADP-ribose) polymerase (PARP). These results indicated that 8,9-DNP induced caspase-dependent apoptotic programmed cell death under energy stress conditions. It was also found that 8,9-DNP induced non-apoptotic cell death in the presence/absence of zVAD under energy stress conditions. Immunoblot analysis showed the intracytosolic release of apoptosis-inducing factor (AIF), although it did not further translocate to the nucleus. It appears most likely that, in the presence of zVAD, 8,9-DNP triggered necrotic cell death as a result of severe intracellular ATP depletion.     

Taurine transporter from the giant Pacific oyster <Emphasis Type="Italic">Crassostrea gigas</Emphasis>: function and expression in response to hyper- and hypo-osmotic stress

ABSTRACT:   Taurine is the primary osmolyte in marine molluscs, whose cellular osmo-conforming process is vital for environmental adaptation because of a lack of osmotic homeostasis. Here, cDNA cloning and expression, and functional analyses of taurine transporter (TAUT) from the giant Pacific oyster are reported on. The deduced amino-acid sequence of oyster TAUT (oyTAUT) showed 47–51% identity to those of vertebrate TAUT, whereas identity among the vertebrates is 78–95%. Functional analysis of oyTAUT expressed in Xenopus oocytes revealed that oyTAUT has a lower affinity and specificity for taurine and a requirement for higher NaCl concentration, compared with vertebrate TAUT. Taken together with similar functional properties of TAUT from mussel, indicated by our previous study, it is possible that these functional features reflect the internal environment of the molluscs (i.e. higher taurine and NaCl concentrations). Oyster taurine transporter mRNA expression was induced by not only hyper-osmotic stress, similar to other TAUT, but also hypo-osmotic stress. It is speculated that the expression in response to hypo-osmotic stress was induced by a substantial decrease in tissue taurine content following the decrease in the internal osmolality.     

The incidence of disseminated intravascular coagulation in dogs with malignant tumor

The incidence of DIC in 208 dogs with a malignant tumor was evaluated. The incidence of DIC was 9.6% in dogs with a malignant tumor which was a solid tumor in all. In 164 dogs with a malignant solid tumor, the incidence of DIC was 12.2%. The incidence of DIC in dogs with hemangiosarcoma, mammary gland carcinoma and adenocarcinoma of the lung was significantly higher than that in dogs with other malignant tumors. These results suggested that special care in looking for DIC should be taken in dogs with a malignant solid tumor.     

Effect of intramammary injection of rboGM-CSF on milk levels of chemiluminescence activity, somatic cell count, and Staphylococcus aureus count in Holstein cows with S. aureus subclinical mastitis

The effect of intramammary injection of recombinant bovine granulocyte-macrophage colony-stimulating factor (rboGM-CSF, 400 microg/10 mL) on quarter milk levels of chemiluminescence (CL) activity, and somatic cell count (SCC) and shedding pattern of Staphylococcus aureus was investigated. Ten Holstein cows, naturally infected with S. aureus were used, with either early-stage or late-stage subclinical mastitis. Injection of rboGM-CSF caused a remarkable increase in milk CL activity with a peak at 6 h after the cytokine injection in the early- and late-stage groups. In the early-stage group, milk SCC stayed around preinjection level at 6 h, rose significantly on days 1 and 2, and was followed by a smooth and significant decline to an under preinjection level (below 200 000 cells/mL) on day 7 postinjection. Alternatively, in the late-stage group, milk SCC rose significantly at 6 h after the cytokine injection and maintained high levels thereafter. The milk S. aureus count decreased drastically by the cytokine injection in the early-stage group. The bacterial count was moderately decreased in the late-stage group, but increased back to preinoculation levels on day 7 after the cytokine injection. The results suggest that the rboGM-CSF has a potential as a therapeutic agent for S. aureus infection causing subclinical mastitis of dairy cows, if the cytokine is applied at the initial stage of infection.     

Electroencephalographic observation on sheep and cattle with experimental cerebrocortical necrosis

Nine Suffolk sheep and 4 Holstein cattle were employed to observe electroencephalographic changes in experimental cerebrocortical necrosis. Amprolium (600 mg/kg/day) alone was given intraruminally 6 sheep and 4 cattle, all of which showed neurological signs and abnormal electroencephalograms. Both amprolium and thiamine (200 mg/day) and thiamine (50 mg/day) alone were given 2 and 1 sheep, respectively, as controls, which did not show any abnormal signs. Abnormal electroencephalograms included continuous slow waves and long-lasting spindles, both of which appeared diffusely and were seen subclinically or with neurological signs. The spindles consisted of slow waves or sharp- (or spike-) and-slow-wave complexes with or without convulsive seizures even during the convulsion stage. Conversely, the seizures occurred with the spindles or slow waves.