Localization of Plant Lipids for Light Microscopy Using P-Phenylenediamine in Tissues of Arachis Hypogaea L.

p-Phenylenediamine (pPD) can be used en bloc to preserve and differentiate cell lipids in aldehyde-fixed peanut plant tissues treated with osmium tetroxide during dehydration in 70% ethanol. Semithin plastic sections for light microscopy need o further staining and can be mounted in Histoclad after drying on a slide. Brown staining above background differentiates lipid-containing structures. Nonspecific staining can be distinguished in control preparations extracted en bloc with lipid solvents.     

Localization of Acid and Alkaline Phosphatases in Staphylococcus aureus

The localization of acid and alkaline phosphatases in Staphylococcus aureus was studied by fractionation of cells after treatment with the L-11 enzyme and by electron microscopic histochemistry. The two enzyme activities were located in distinctly different positions at the surface of the cells. Acid phosphatase appeared to be localized around the cell membrane of the bacteria, because the enzyme was recovered exclusively in the membrane fraction and because deposition of lead phosphate was detected by electron microscopic histochemistry on the inner surface of the cell membrane of intact bacteria and spheroplasts. The highest specific activity of alkaline phosphatase was also associated with the membrane fraction. However, on electron microscopic histochemistry of intact cells, the deposition of lead phosphate was only seen on the outer surface of the cell wall.     

Rhythmical Variations Accompanying Gustatory Stimulation Observed by Means of Localization Phenomena

When two taste stimuli are presented, one to each side of the tongue, with a time delay of up to 1 msec., the taste sensation seems to move across the tongue. This phenomenon which is similar to directional hearing, can be used to show periodic fluctuations in sensation magnitude as well as other aspects of sensation. When the apparatus was refined to present taste stimuli, it was possible to observe rhythmic changes in the perception of taste. An analogy is demonstrated between hearing and taste sensation, even to some quantitative values.     

梨花中熊果苷的高效液相色谱分析

采用高效液相色谱法对不同时期、不同品种的梨花中熊果苷的含量进行了分析,色谱柱为Hypersil BDSC18(4.6 mm×250 mm,5μm),流动相为甲醇∶水(6∶94),加入甲酸0.05%,检测波长280 nm。结果表明:熊果苷在0.01～5.00μg范围内线性关系良好(r=0.9999),平均加标回收率为97.7%。不同生长期的鸭梨梨花中熊果苷的含量一般在10 mg/g以上,尤以花芽萌动期时含量最高,达到35.7 mg/g(鲜重计)。不同品种的9份梨花样品中,熊果苷含量在3.5～10.5 mg/g之间。     

Localization of MINUTES to Specific Polytene Chromosome Bands by Means of Overlapping Duplications

Overlapping duplications recovered as suppressors of Minute loci have been used to localize M(2)z and M(3)w¹²⁴ to specific polytene bands 25A1(2) and 95A1(2). The surprising efficiency of M localization by duplication may result from the tendency of M suppressors to be at least a visible fraction of a polytene band in length.     

薄层扫描法测定7种腹水草属植物中熊果甙的含量

本文用薄层扫描法测定了７种腹水草属药用植物中熊果甙的含量,并对提取及定量方法进行了考察。     

Histochemical Localization of Alkaline Phosphatases and {beta}-Glucosidases in Cucurbitaceae

The distribution of alkaline phosphatases and ß-glucosidasesin the tissues of the stems of Colocynthls citrullus, Cucumissativus and Cucurbita pepo was studied. There was similarityin the pattern of distribution for these two groups of enzymesand that of acid phosphatases. The activities of these enzymesvaried not only from plant to plant but also from tissue totissue. However both enzymes showed increasing activity withplant age and localization was correspondingly more restricted.The significance of these localizations is discussed.     

Localization in the Cell and Extraction of Alkaline Phosphatase from Bacillus subtilis

Study of protoplasts, lysed protoplasts, and cells treated with lysozyme in the absence of osmotic stabilizer suggested that the alkaline phosphatase (EC 3.1.3.1.) of Bacillus subtilis is located in the protoplasmic membrane. Cytochemical evidence in support of this view is presented. The enzyme protein was strongly bound to the membrane structure and could not be solubilized by a number of treatments known to release enzymes from membranes and other lipoprotein structures. Alkaline phosphatase was, however, solubilized by treatment of intact B. subtilis cells or isolated protoplasmic membranes with strong salt solutions at pH 7.2, suggesting that electrostatic forces are responsible for the association between membrane and enzyme protein. Dialysis of alkaline phosphatase solutions against buffer of low ionic strength resulted in precipitation of the enzyme.     

Biochemical Localization of Alkaline Phosphatase in the Cell Wall of a Marine Pseudomonad

The various layers of the cell envelope of marine pseudomonad B-16 (ATCC 19855) have been separated from the cells and assayed directly for alkaline phosphatase activity under conditions established previously to be optimum for maintenance of the activity of the enzyme. Under conditions known to lead to the release of the contents of the periplasmic space from the cells, over 90% of the alkaline phosphatase was released into the medium. Neither the loosely bound outer layer nor the outer double-track layer (cell wall membrane) showed significant activity. A small amount of the alkaline phosphatase activity of the cells remained associated with the mureinoplasts when the outer layers of the cell wall were removed. Upon treatment of the mureinoplasts with lysozyme, some alkaline phosphatase was released into the medium and some remained with the protoplasts formed. Cells washed and suspended in 0.5 M NaCl were lysed by treatment with 2% toluene, and 95% of the alkaline phosphatase in the cells was released into the medium. Cells washed and suspended in complete salts solution (0.3 M NaCl, 0.05 M MgSO(4), and 0.01 M KCl) or 0.05 M MgSO(4) appeared intact after treatment with toluene but lost 50 and 10%, respectively, of their alkaline phosphatase. The results suggest that the presence of Mg(2+) in the cell wall is necessary to prevent disruption of the cells by toluene and may also be required to prevent the release of alkaline phosphatase by toluene when disruption of the cells by toluene does not take place.     

Expression and Localization of Escherichia coli Alkaline Phosphatase Synthesized in Salmonella typhimurium Cytoplasm

The Escherichia coli structural gene for alkaline phosphatase was inserted into Salmonella typhimurium by episomal transfer in order to determine whether this enzyme would continue to be localized to the periplasmic space of the bacterium even though it was formed in a cell that does not synthesize alkaline phosphatase. The S. typhimurium heterogenote synthesized alkaline phosphatase under conditions identical to that observed with E. coli. This enzyme appeared to be identical to that synthesized by E. coli, and was quantitatively released from the bacterial cell by spheroplast formation with lysozyme. These results showed that localization is not a property unique to the E. coli cell and suggested that, in E. coli, enzyme location is related to the structure of the protein. Formation of alkaline phosphatase in the S. typhimurium heterogenote was repressed in cells growing in a medium with excess inorganic phosphate, even though only one of the three regulatory genes for this enzyme is on the episome. Thus, S. typhimurium can supply the products of the other two regulatory genes essential for repression even though this bacterium seems to lack the structural gene for alkaline phosphatase.     

Effect of Arbutin on Melanogenic Proteins in Human Melanocytes

The inhibitory effect of arbutin, a naturally occurring β-D-glucopyranoside derivative of hydroquinone, on melanogenesis was studied biochemically by using human melano-cytes in culture. Cells were cultured in the presence of different concentrations of arbutin. The maximum concentration of arbutin that was not inhibitory to growth of the cells was 100 ug/ml. At that concentration, melanin synthesis was inhibited significantly by ～20% after 5 days, compared with untreated cells. This phenotypic change was associated with the inhibition of tyrosinase and DHICA polymerase activities, and the degree of inhibition was dose dependent. No significant difference in DOPAchrome tautomerase (DT) activity was observed before or after arbutin treatment. Western blotting experiments revealed there were no changes in protein content or in molecular size of tyrosinase, TRP-1 or TRP-2, indicating that inhibition of tyrosinase activity by arbutin might be due to effects at the post-translational level.     

Preoperative Tumor Localization by Means of Venous Sampling for Fibroblast Growth Factor-23 in a Patient with Tumor-Induced Osteomalacia

ObjectiveTo report on a novel strategy for tumor localization in a 62-year-old man with hypophosphatemic tumor-induced osteomalacia (TIO).MethodsRepeated computed tomographic and magnetic resonance imaging scans failed to localize any tumor in a patient with adult-onset hypophosphatemic osteomalacia. Therefore, venous sampling for fibroblast growth factor-23 (FGF23)—a circulating hormone that has been identified as a causative factor for TIO—in major veins was conducted. Serum FGF23 was measured from collected samples by an intact FGF23 enzyme-linked immunosorbent assay.ResultsVenous sampling suggested a local increase in serum FGF23 in the left femoral vein; this finding prompted performance of octreotide scintigraphy restricted to the left leg. A tumor was located at the lateral condyle of the left femur, which was also confirmed by magnetic resonance imaging. Surgical resection of the tumor normalized the serum phosphorus and 1,25-dihydroxyvitamin D₃ levels within 5 to 10 days, and FGF23 declined to normal levels within 24 hours. Histologic analysis supported the diagnosis of a soft-tissue giant cell tumor.ConclusionOur study case demonstrates the diagnostic complexity and difficulties in localizing a small tumor in a patient with TIO. Venous sampling for FGF23 may be helpful in tumor localization in sporadic cases of hypophosphatemic osteomalacia, especially when noninvasive diagnostic techniques prove insufficient. (Endocr Pract. 2008;14:362-367)     

Localization of Polyribosomes Containing Alkaline Phosphatase Nascent Polypeptides on Membranes of Escherichia coli

A procedure has been developed for extracting membranes from bacterial cells under conditions that keep a large fraction of bacterial polyribosomes intact. Freeze-thawing spheroplasts in the presence of deoxyribonuclease, followed by differential centrifugation, permits a separation of free and membrane-associated polyribosomes. The latter fraction contains as much as 40% of cell ribosomal ribonucleic acid (RNA) and 55% of cell messenger RNA (mRNA). Nascent polypeptides were divided almost equally between the two fractions, but 70 to 80% of alkaline phosphatase nascent chains, detected both chemically and immunologically, were derived from polyribosomes associated with the bacterial membrane. Analysis of the fractions for mRNA specific for the lac and trp operons by RNA-deoxyribonucleic acid hydridization showed somewhat larger amounts on membrane than on free polyribosomes, but enrichment for nascent alkaline phosphatase (a secreted protein) on membranes was consistently greater, suggesting that polyribosomes making secreted proteins are more tightly bound to membranes. Electron micrographs of the membrane preparations show relatively intact membranes with clusters of polyribosomes on their inner surfaces.     

Arbutin blocks defects in the ripple phase of DMPC bilayers by changing carbonyl organization

The effect of arbutin, a 4-hydroxyphenyl-beta-glucopyranoside, on dimyristoylphosphatidylcholine (DMPC) bilayers was studied by turbidimetry, EPR and FTIR spectroscopies. The disruption of DMPC multilamellar vesicles (MLV's) with monomyristoylphosphatidylcholine (lysoPC), a product of hydrolysis of phospholipase A(2) (PLA(2)), is more efficient at 18 degrees C, where DMPC MLV's are known to be in the ripple P(beta') phase, than at 10 degrees C (L(beta') flat gel phase). Disruption at 18 degrees C was inhibited by increasing concentrations of arbutin in the solution. This inhibition was correlated with the disappearance of the ripple phase in MLV's when arbutin is present. Shifts in FTIR carbonyl bands caused by arbutin or by temperature changes allow us to propose a model. It is interpreted that the changes in the water-hydrocarbon interface caused by arbutin, forcing a reaccommodation of the carbonyl groups, eliminate the topological defects in the lattice due to mismatches among regions with different area per lipid where lysoPC can insert.     

Antioxidative Activity of Arbutin in a Solution and Liposomal Suspension

Chattonella marina, a raphidophycean flagellate, is one of the most toxic red tide phytoplankton and causes severe damage to fish farming. Recent studies demonstrated that Chattonella sp. generates superoxide (), hydrogen peroxide (H₂ O₂), and hydroxyl radicals (·OH), which may be responsible for the toxicity of C. marina. In this study, we found that other raphidophycean flagellates such as Hetevosigma akashiwo, Otisthodiscus luteus, and Fihrocapsa japonica also produce and H₂O₂ under normal growth condition. Among the flagellate species tested, Chattonella has the highest rates of production of and H₂O₂ as compared on the basis of cell number. This seems to be partly due to differences in their cell sizes, since Chattonella is larger than other flagellate species. The generation of by these flagellate species was also confirmed by a chemiluminescence assay by using 2-methyl-6-(p-methoxyphenyl)-3,7-dihydroimidazo[l,2-a]pyrazin-3-one (MCLA). All these raphidophycean flagellates inhibited the proliferation of a marine bacterium, Vibrio alginolyticus, in a flagellates/bacteria co-culture system, and their toxic effects were suppressed by the addition of superoxide dismutase (SOD) or catalase. Our results suggest that the generation of reactive oxygen species is a common feature of raphidophycean flagellates.     

New Insight into the Interactions of Arbutin with Mushroom Tyrosinase

The Protein Journal - As a safe substitute for hydroquinone, β-arbutin, a natural plant substance, and its synthetic counterpart, α-arbutin, are used in depigmentation formulations....     

Enzymhistochemical Localization of Alkaline Phosphatases in Germinal Cysts of the Testis of the Frog Rana temporaria (Anura)

Alkaline phosphatases have been demonstrated enzymhistochemically in the testis of the common frog Rana temporaria, caught in the month of January. The follicle cells in the cyst walls and the lamina propria of the seminiferous tubules showed strong enzymatic activity; also a weak activity was observed in the peripheral region of some of the germinal cells lying within the cysts. The possible interaction of alkaline phosphatases in the transport processes across the cyst walls has been discussed.     

Arbutin ameliorates glucocorticoid-induced osteoporosis through activating autophagy in osteoblasts

Chronic long-term glucocorticoid use causes osteoporosis partly by interrupting osteoblast homeostasis and exacerbating bone loss. Arbutin, a natural hydroquinone glycoside, has been reported to have biological activities related to the differentiation of osteoblasts and osteoclasts. However, the role and underlying mechanism of arbutin in glucocorticoid-induced osteoporosis are elusive. In this study, we demonstrated that arbutin administration ameliorated osteoporotic disorders in glucocorticoid dexamethasone (Dex)-induced mouse model, including attenuating the loss of bone mass and trabecular microstructure, promoting bone formation, suppressing bone resorption, and activating autophagy in bone tissues. Furthermore, Dex-stimulated mouse osteoblastic MC3T3-E1 cells were treated with arbutin. Arbutin treatment rescued Dex-induced repression of osteoblast differentiation and mineralization, the downregulation of osteogenic gene expression, reduced autophagic marker expression, and decreased autophagic puncta formation. The application of autophagy inhibitor 3-MA decreased autophagy, differentiation, and mineralization of MC3T3-E1 cells triggered by arbutin. Taken together, our findings suggest that arbutin treatment fends off glucocorticoid-induced osteoporosis, partly through promoting differentiation and mineralization of osteoblasts by autophagy activation.     

应用荧光原位杂交技术检测人类APPSWE基因在转基因小鼠染色体上的定位及位置效应

应用荧光原位杂交技术研究了人类淀粉样前体蛋白基因瑞典型突变（APPSWE）在转基因小鼠首建、F1及F2代小鼠染色体上的整合及定位,结果在2只首建转基因小鼠中,分别观察80个分裂相,出现杂交信号的核型分别为34及36个,检出率为42.5%和45%;1只F1及1只F2代转基因小鼠中,分别观察100个分裂相,出现杂交信号的核型分别为33及30个,检出率为33%和30%。转基因分别整合在8号、1号、17号和2号染色体上,提示转基因APPSWE已稳定整合到转基因小鼠的染色体上,并通过生殖细胞遗传给予子代,证实转基因在小鼠染色上的整合可能是随机的多点整合,同时,对不同整合位点的转基因小鼠进行了表型研究,结果发现不同整合位点对表型具明显影响。