Search

We have optimized the conditions for visualizing microfilaments, microtubules, and coated pits in the cortical cytoplasm of high-pressure frozen and freeze-substituted plant cells, in both tobacco root tips and onion cotyledons, individual microfilaments and the supramolecular structure of coated pits can be seen clearly in freeze-substituted samples treated with OsO4 at 40 degrees C followed by 5% uranyl acetate. Treatment with uranyl acetate alone resulted in poorly stained cytoplasmic organelles, whereas microfilaments were difficult to discern in specimen treated with OsO4 alone. The combination of a 40 degrees C OsO4 staining step followed by staining with uranyl acetate at 4 degrees C should prove useful for more detailed plant cytoskeletal/membrane studies in the future.

Free Style Libre Pro, a novel continuous glucose monitoring (CGM) device for retrospective assessment of glycemic excursion, does not require calibration during the measurement period. In this study, the accuracy of FreeStyle Libre Pro in normal glucose levels was investigated. Two meal tests, on the 7th day and 9th day of CGM usage, were performed in five non-diabetic adults. Venous blood samples were obtained at baseline, and at 2 hours, 4 hours and 6 hours after the meal. The plasma glucose levels and the glucose levels measured by FreeStyle Libre Pro were compared. Subjects were aged 41.4±7.6 years, 40% male, with body mass index 21.7±2.6, HbA1c 5.6±0.3% and a fasting plasma glucose level of 95.4±2.1 mg/dl. The plasma glucose levels and the glucose levels measured by FreeStyle Libre Pro were significantly different; 94.4±1.8 vs. 111.2±8.5 mg/dl (P

Plants are valuable systems for analyzing the acentriolar mitotic spindle. We have developed methods for imaging the mitotic spindle in living tobacco (Nicotiana tabacum) suspension culture cells expressing GFP-α-tubulin. The methods allow the spindle to be observed in living cells at high spatial and temporal resolution and rely on water immersion objectives, spinning disk optics, and high-sensitivity cameras. Here, we describe these methods and provide step-by-step protocols for certain key steps. We also describe a method for application and removal of inhibitors.

Plants are valuable systems for analyzing the acentriolar mitotic spindle. We have developed methods for imaging the mitotic spindle in living tobacco (Nicotiana tabacum) suspension culture cells expressing GFP-α-tubulin. The methods allow the spindle to be observed in living cells at high spatial and temporal resolution and rely on water immersion objectives, spinning disk optics, and high-sensitivity cameras. Here, we describe these methods and provide step-by-step protocols for certain key steps. We also describe a method for application and removal of inhibitors.

The interleukin-13 receptor (IL-13R) complex is composed of 2 different chains, IL-13Ralpha1 (also known as IL-13Ralpha') and IL-13Ralpha2 (also known as IL-13Ralpha). For a functional IL-13 receptor, the IL-13Ralpha1 chain forms a productive complex with the primary IL-4 binding protein (IL-4Ralpha also known as IL-4Rbeta). However, the function of the IL-13Ralpha2 chain is not clear even though this chain binds IL-13 with high affinity. This study demonstrates that IL-13Ralpha2 can undergo internalization after binding to ligand without causing activation of its signaling pathways. These conclusions were drawn on the basis of (1) internalization of (125)I-IL-13 in Chinese hamster ovarian (CHO-K1) and T98G glioblastoma cells transiently transfected with the IL-13Ralpha2 chain; (2) a recombinant chimeric fusion protein comprising IL-13 and a mutated form of Pseudomonas exotoxin (termed IL13-PE38QQR or IL-13 toxin) is specifically cytotoxic to IL-13Ralpha2-transfected CHO-K1 cells in a gene dose-dependent manner, whereas cells transfected with vector alone were not sensitive; and (3) IL-13 did not cause activation of signal transduction and activation of transcription 6 (STAT6) in IL-13Ralpha2-transfected cells. IL-13 efficiently caused activation of STAT6 protein in cells transfected with the IL-13Ralpha1 and IL-4Ralpha chains, and IL-13Ralpha2 inhibited this activation. Taken together, these observations indicate that internalization of IL-13Ralpha2 is signal independent and that this property of IL-13Ralpha2 can be exploited for receptor-directed cancer therapy.

The relevance of pilus-related genes to motility, pilus structure on the cell surface and competency of natural transformation was studied by gene disruption analysis in the unicellular motile cyanobacterium Synechocystis: sp. PCC 6803. The genes disrupted in this study were chosen as related to the pil genes for biogenesis of the type IV pili in a Gram-negative bacterium Pseudomonas aeruginosa. It was found that motility of Synechocystis cells was lost in the mutants of slr0063, slr1274, slr1275, slr1276, slr1277 and sll1694 together with a simultaneous loss of the thick pili on the cell surface. Competency of the natural transformation was lost in the mutants listed above and slr0197-disruptant. The gene slr0197 was previously predicted as a competence gene by a search with sequence-independent DNA-binding structure [Yura et al. (1999) DNA Res. 6: 75]. It was suggested that both DNA uptake for natural transformation and motility are mediated by a specific type IV-like pilus structure, while a putative DNA-binding protein encoded by slr0197 is additionally required for the DNA uptake. Based on the homology with the pil genes in P: aeruginosa, slr0063, slr1274, slr1275, slr1276, slr1277 and sll1694 were designated pilB1, pilM, pilN, pilO, pilQ and pilA1, respectively. The gene slr0197 was designated comA.

It is difficult for new sciences and big technologies such as life sciences, nuclear energy, biotechnology, etc. to achieve the appropriate public understanding. One of the issues is the lack of scientific literacy in the public. We propose a new type of nuclear reactor to prepare the opportunity for the public to be acquainted with the information and technology of the nuclear science and engineering. This reactor for interpretation is a symbolic facility adjacent to the scientific and technological museum.Features of the interpretative rector must be safety and openness. The safety is satisfied by the excess reactivity less than 0.5%Δk/k and little burn up based on the thermal output less than 1W.

Since the introduction of warm compaction in 1994, several new warm-compacted powder metallurgy (P/M) parts have been developed. However, the main applications to date have been limited to machine tool parts and parts for agricultural tools, for example. Only a few automotive parts have been developed by using the warm-compaction method. Engine parts have not yet to be developed, particullary. Here, we investigate the mechanical properties and wear resistance of warm-compacted P/M materials, and the developed warm-compacted P/M engine sprockets. A method of controlling the powder temperature is also described.

Aim: To describe the extremely rare case of an adenomyoma of the papilla of Vater. Case Report: A 42-year-old woman was hospitalized for epigastralgia and high fever. The clinical presentation and endoscopic, biochemical, and radiologic findings led to the diagnostic impression of a dysfunction of the papilla of Vater. The patient was treated successfully by laparotomy and duodenotomy, incorporating cholangiomanometry and cholangiography. Intraoperative frozen-section examination of a transduodenal papillectomy specimen led to the diagnosis of adenomyomatosis of the papilla. The patient is doing well 38 months postoperatively. Conclusion: Such a combined approach to intraoperative diagnosis was important to avoid excessive surgery for a benign periampullary disease.

Molybdenum sulfide cluster [Mo 3 S 4 (H 2 O) 9 ] 4+ and nickel–molybdenum bimetallic sulfide cluster [Mo 3 NiS 4 Cl(H 2 O) 9 ] 3+ were incorporated into zeolites NaY, HUSY, NaHβ, Na-mordenite (NaMOR), and KL by aqueous ion exchange. EXAFS data revealed that the structure of the molybdenum sulfide cluster remained virtually intact after ion exchange. However, the incomplete cubane-type structure of the cluster might be lost after thermal treatment at 573 K. The structure of the cluster in Mo 3 S 4 /NaY and Mo 3 S 4 /KL seems to have changed to the MoS 2 -like structure through the hydrodesulfurization (HDS) reaction, although a considerably high level of dispersion was kept. Mo 3 S 4 cluster catalysts loaded on NaMOR and KL exhibited a higher level of activity for HDS of benzothiophene than Mo 3 S 4 catalysts loaded on the other zeolites. Benzene was formed through acid-catalyzed dealkylation of ethylbenzene, the primary HDS product. Alkylation of benzothiophene with alkenes derived from the cracking of decane as the solvent also occurred. The acidity seems to be produced through the ion exchange and reduction of cationic clusters during activation. Over HUSY- and NaHβ-supported catalysts benzene was the major HDS product. Nickel incorporation into the Mo 3 S 4 zeolite catalysts remarkably enhanced the HDS activity. Introduction of the Mo 3 NiS 4 core into zeolite as a precursor resulted in catalysts with higher HDS activity than that of Mo 3 S 4 core and Ni 2+ independently; it is conceivable that the intimate interaction between nickel and molybdenum in the precursor is effective at producing active species.

We isolated a novel oxidized sorbicillin dimer (1) as yellowish amorphous powder from the fermentation broth of Trichoderma sp. USF-2690 strain isolated from a soil sample. The structure of the compound was determined by elucidation of spectroscopic evidence. The compound was revealed to possess a new carbon skeleton in the group of oxidized sorbicillin dimers and was named bisorbibetanone. The stereostructure of bisorbibetanone was analyzed on the basis of the spectral data. In 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging assay, bisorbibetanone gave an ED30 value of 62.5 μM after standing for 30 min.

In hematopoietic cells, interleukin-2 receptor (IL-2R) γ chain (termed γc) is shown to be a component of the IL-4R system, whereas in nonhematopoietic cells, γc is absent and it is not a component of the IL-4R system. Here, we show that the IL-13R α′ chain (termed IL-13Rα′) but not the IL-13R α chain (termed IL-13Rα) can substitute for γc and, thus, IL-13Rα′ forms a novel component of the IL-4R system. This conclusion was drawn on the basis of chemical cross-linking, immunoprecipitation, the ability of IL-13Rα′ but not IL-13Rα to augment IL-4 binding affinity, and the requirement of IL-13Rα′ for IL-4–induced STAT6 activation in Chinese hamster ovary (CHO) cells transfected with various receptor subunits. Cotransfection of IL-4 receptor p140 (termed IL-4Rβ) with γc or IL-13Rα′ increased IL-4 binding affinity and allowed for STAT6 activation in response to IL-4. However, cotransfection of all three chains did not further increase IL-4 binding or alter the extent of STAT6 activation suggesting that all three chains together do not seem to participate in IL-4 function. Instead, IL-4Rβ heterodimerizes with γc or IL-13Rα′ and mediates STAT6 activation. Cotransfection of IL-4Rβ with IL-13Rα neither increased IL-4 binding affinity nor allowed for STAT6 activation in response to IL-4 indicating that IL-13Rα does not convert binding affinity nor transmit signals for IL-4. Because IL-4 phosphorylates JAK1 and JAK2 tyrosine kinases in nonhematopoietic cells, we investigated whether JAK1 and JAK2 are required for IL-4–induced STAT6 activation in various transfectants. Cotransfection experiments with different chains of IL-4R and kinase-deficient JAK1 and JAK2 mutants in CHO cells showed that JAK1 and JAK2 are required for optimal activation of STAT6 in the α′β transfectant but only partially in the βγc transfectant. Taken together, our results show that IL-13Rα′ is a novel functional component of the IL-4R system and that JAK1 and JAK2 mediate IL-4–induced optimal activation of STAT6 in nonhematopoietic cells.

Three yellowish compounds with 1,1-diphenyl-2-picrylhydrazyl-radical scavenging activity were newly isolated from the fermentation broth of Trichoderma sp. USF-2690 strain that had been isolated from a soil sample: two were novel oxidized sorbicillin dimers designated as bisorbibutenolide (1) and bisorbicillinolide (2), and one was sorbicillin (3) itself. The structures of 1 and 2 were determined from spectroscopic evidence. In the DPPH-radical scavenging assay, α-tocopherol gave an ED50 value of 17.0 μM after standing for 30 min, while continuing observation showed that the ED50 values for bisorbibutenolide, bisorbicillinolide, and sorbicillin slowly reached 80.8, 88.8 and 152.3 μM over 24 hr.

In our screening program for antioxidants with DPPH radical scavenging activity, we isolated four yellowish compounds from the fermentation broth of Trichoderma sp. USF-2690 strain isolated from a soil sample: two were novel compounds designated bisorbicillinol (1) and demethyltrichodimerol (2), and two were known compounds bisvertinolone (3) and trichodimerol (4). The structures of 1 and 2 were elucidated by spectroscopic evidence and chemical modification. Two compounds seemed to be the oxidized dimers of sorbicillin. In the evaluation of DPPH radical scavenging activity, bisorbicillinol gave the lowest ED50 value (31.4 μM) among the four compounds, equal to that of BHT (27.0 μM).

We have employed high pressure freezing techniques to examine cytoskeletal and membrane structures in meristematic cells of plant seedlings. This method results in improved preservation of preprophase bands of microtubules as well as other structures in onion and tobacco roots and in meristematic cells of onion cotyledons. In this paper, we describe the use of high pressure freezing and freeze substitution to obtain thin sections of samples embedded in Spurr's resin and discuss problems with these procedures. We also present new results obtained from high pressure frozen cells and discuss the possible applications of high pressure freezing in plant cell biology.

This study demonstrated the decrease of bone mineral density (BMD) in the type II collagen (CII)-induced arthritis (CIA) model in rats and the relationship between BMD and paw edema and the effect of dexamethasone-21-phosphate (DEX). The paw swelling occurred on Day 10 and reached its peak on Day 18 after CII injection. BMD in the CII-injected group is lower than that in the control group. BMD in the proximal and distal regions of the femur largely decreased in comparison with that of the middle region. The oral administration of DEX (0.1 mg/kg) inhibited the swelling and decrease of BMD in all three regions of the femur.

The molybdenum sulfide cluster [Mo 3 S 4 (H 2 O) 9 ] 4+ ( 1 ) and the nickel-molybdenum bimetallic sulfide cluster [Mo 3 NiS 4 Cl(H 2 O) 9 ] 3+ ( 2 ) were incorporated into zeolites NaY, HUSY, KL, NaMOR and NaH β by aqueous ion-exchange. The catalysts supported on KL and NaMOR exhibited a higher activity for hydrodesulfurization (HDS) of benzothiophene than catalysts supported on other zeolites. Nickel incorporation into Mo/zeolite catalysts enhanced the HDS activity remarkably. Teh catalysts prepared by ion-exchanging zeolites with 2 were more active in the HDS reaction than the catalysts prepared by ion-exchanging 1 /zeolite with nickel nitrate solution; the presence of the MoSNi linkage in 2 will be effective for producing active HDS species.

This study demonstrates that systemic and local decreases in bone mineral density (BMD) occurred with Freund's complete adjuvant injection in the rat right footpad using dual energy X-ray absorptiometry. The rats were assigned to either adjuvant-treated or non-treated control groups composed of eight animals each. There was significant decrease in BMD in the adjuvant group compared to the control group at the distal region of femur or proximal region of tibia on Day 7 post-adjuvant injection (P < 0.05). On the other hand, the femur or tibia of the noninjected side showed a smaller and delayed decrease in BMD than did the injected side. These decreases in BMD were seen in not only the trabecular but also the cortical bone. In addition, the vertebrae also showed delayed but significant decrease (P < 0.05) in BMD on Day 21.

A phragmosome (PS) is a transvacuolar aggregation of cytoplasm that develops in the plane of future cytokinesis and is found specifically in highly vacuolated cells. Although protonemal cells of Adiantum capillus-veneris L. usually do not form a PS, a PS-like structure developed at the site of a preprophase band (PPB) of microtubules (MTs) when the nucleus and endoplasm were displaced from the division site by centrifugation, leaving a PPB in the cortical cytoplasm. The PS-like structure contained endoplasmic MTs, Factin, oil droplets and mitochondria. The structure did not develop when the cells were centrifuged before the formation of a PPB. Application of amiprophos-methyl (APM) before development of the PPB strongly inhibited the formation of the PS-like structure after centrifugation. The PS-like structure was dispersed after cytokinesis which occurred in the region of the displaced nucleus. Treatment with APM after the formation of the PS-like structure arrested the cell cycle at the M phase and inhibited the degradation of this structure. These results suggest that development of a PS-like structure is associated both with the formation of a PPB and with the stage of the cell cycle.

We have reported that human ovarian-carcinoma cell lines express high-affinity IL-4 receptor. Since IL-4R has been hypothesized to share a chain with IL-13R, we investigated whether ovarian cancer cells express IL-13 receptor. In the present study, we report that the ovarian-carcinoma cell lines IGROV-1 and PA-1 express varying numbers of high-affinity IL-13 receptors. Furthermore, IL-13 inhibited the binding of IL-4 on both ovarian-carcinoma cell lines, while IL-4 did not inhibit IL-13 binding on IGROV-1 cell line. IL-13 and IL-4 induced the phosphorylation of JAK1, JAK2 and Tyk2 Janus kinases in PA-1 cells. In contrast, JAK3 tyrosine kinase was expressed in PA-1 cells, but IL-4 or IL-13 did not augment its phosphorylation. In IGROV-1 cells, Tyk2 was constitutively phosphorylated and this phosphorylation was augmented by IL-4 or IL-13. JAK1 and JAK2 but not JAK3 were expressed but only JAK2 was faintly phosphorylated in response to either IL-13 or IL-4 respectively. IRS (insulin-receptor substrate)-1 and IRS-2 were also phosphorylated constitutively in both ovarian cancer cell lines examined, but only the phosphorylation of IRS-1 was augmented in response to IL-4 or IL-13. STAT6 was phosphorylated and activated in response to IL-4 and IL-13 in all cell lines examined. Our results demonstrate that ovarian cancer cell lines may express 2 types of IL-13R and the IL-13- or IL-4-induced signaling patterns may be slightly different in each type of receptor.

Gametophytes of Ceratopteris richardii developed into strap-shaped prothalli in the dark. The prothalli had an apical meristem, a subapical elongation zone and a basal zone where no growth occurred. Continuous irradiation of blue light inhibited cell growth of the elongation zone, although red or far-red light had no effect on elongation. Cortical microtubules (MTs) of subapical cells reoriented from transverse to oblique or parallel to the growing axis during blue light inhibition. Each region of the strap-shaped prothallus was irradiated with a micro-beam of blue light. Cell elongation in the subapical region was not inhibited by irradiation at the apical meristem. Irradiation of the subapical region inhibited cell elongation to a similar extent as the whole irradiation control. When a single elongating cell at one side of the subapical region was irradiated by a blue microbeam, elongation was inhibited in a cell at the irradiate side only, resulting in a bowing prothallus. Cortical MTs reoriented from transverse to longitudinal to the cell axis in irradiated cells only. The results indicate that each cell in the subapical region perceives blue light by itself, reorients only its cortical MTs and ceases only its cell elongation, independent of surrounding cells.

In land plants, the cell plate partitions the daughter cells at cytokinesis. The cell plate initially forms between daughter nuclei and expands centrifugally until reaching the plasma membrane. The centrifugal development of the cell plate is driven by the centrifugal expansion of the phragmoplast microtubule array, but the molecular mechanism underlying this expansion is unknown. Here, we show that the phragmoplast array comprises stable microtubule bundles and dynamic microtubules. We find that the dynamic microtubules are nucleated by γ-tubulin on stable bundles. The dynamic microtubules elongate at the plus ends and form new bundles preferentially at the leading edge of the phragmoplast. At the same time, they are moved away from the cell plate, maintaining a restricted distribution of minus ends. We propose that cycles of attachment of γ-tubulin complexes onto the microtubule bundles, microtubule nucleation and bundling, accompanied by minus-end-directed motility, drive the centrifugal development of the phragmoplast., Plant cell division is driven by the expansion of the phragmoplast, a characteristic structure that forms in the middle of the plant cell during cytokinesis. Murata et al. use genetic and cell imaging approaches to clarify the microtubule behaviour that leads to phragmoplast expansion.

Traditional polymer capacitors used for pulsed power and power electronics applications have severe limitations in terms of portability and high temperature reliability. Alkali-free glass is a promising material for high temperature and high power capacitors because of its low dielectric loss and high breakdown strength (10 MV/cm), resulting in energy density values higher than 35 J/cm3. Thin glass sheet production has grown substantially because of the strong demand from the flat panel display industry and a large investment in the development of new glass fabrication methods. Several alkali-free glass compositions, such as Schott's AF-45 and NEG's OA-10G barium-boro-alumino-silicate glass, are commercially offered with a permittivity range of 5 to 7 and low dielectric loss (tan δ < 0.5%) values up to temperatures of 200°C. Glass ribbons and sheets are available with thicknesses between 5 and 50 µm and length of up to a few meters.

A Mossy Veil Land plants have two distinct generations: a haploid gametophyte responsible for producing the gametes, and a diploid sporophyte, that in most land plants is the dominant form observed. However, in mosses, a basal land plant, the primary biomass is composed of the haploid gametophyte. Sakakibara et al. (p. 1067 ; see the Perspective by Friedman ) analyzed loss-of-function mutants of KNOX2 (class 2 KNOTTED1-LIKE HOMEOBOX) genes in the moss Physcomitrella patens. Mutant plants exhibit apospory, where fertilization apparently occurs, but the normal sporophyte phase is bypassed and instead a diploid structure resembling a haploid gametophyte is produced. The results suggest that KNOX2 regulates the alternation of generations by suppressing the haploid body plan in the diploid phase.

Zeolites NaY, HUSY and KL were ion-exchanged with a cationic molybdenum sulfide cluster [Mo3S4(H2O)9]4+ with incomplete cubane-type structure and a cationic nickel-molybdenum mixed sulfide cluster [Mo3NiS4Cl(H2O)9]3+ with complete cubane-type structure. The UV-visible spectra and EXAFS analysis data exhibited that the structure of the molybdenum cluster was maintained after ion exchange. These zeolite catalysts showed activity for benzothiophene hydrodesulfurization; especially, involvement of Ni resulted in great enhancement of the hydrodesulfurization activity.

術前Induction therapyを行った39例 (男36, 女3, 平均年齢61.5歳, 扁平上皮癌16, 腺癌12, 大細胞癌1, 小細胞癌10) を対象にその周術期合併症について検討した. 術前合併症としては知覚異常, 心電図異常等の他, 肺塞栓も1例みられた. 術中術後合併症は64.1%の症例にみられ, 同時期の連続100例の肺癌手術例の対照群では26%にとどまった. また術前治療群では手術死亡1, 遠隔期に肺塞栓2, 膿胸3の死亡を認めたが, 対照群に治療関連死亡はなかった. 術前治療施行例ではsubclinica1に合併症, 或はその準備状態が存在するものと考え, 術中術後管理に臨む必要があり, また本治療の施行にあたっては治療効果面のみならず副作用面からの検討も必要であり, 本法の評価が定まらない現在では症例選択も含めて慎重な対処が必要と考えられた.

A formal total synthesis of (±)-aphidicolin (1) was accomplished starting from the tricyclic ketone (2) corresponding to the B/C/D ring system. The quaternary carbon center adjacent to the spirocarbon was constructed stereoselectively by conjugate addition of a methyl group to the enone (7) obtained from 2 in a four-step sequence. The tetracyclic enone (3) was obtained via acid-catalyzed intramolecular aldol condensation of the tricarbonyl compound (10) followed by 1,3-carbonyl transposition, in which Pd(O)-catalyzed reductive deacetoxylation of γ-acetoxy-α,β-enone (15) was a crucial step. The A-ring manipulation was performed by a similar procedure to the Ireland method to give the keto-acetonide (4), a degradation product of 1, which has already been efficiently reconverted to 1

The V-ATPase from Thermus thermophiles is a rotary enzyme, that mediates the coupling between ATP synthesis in the soluble part (V1) and proton translocation across membrane through the membrane-embedded part (Vo). Atomic resolution structural information of the soluble catalytic region has not been obtained yet, and little is known about the high-resolution structure of the Vo. Single particle analysis by cryo-electron microscopy has advanced to a technique for high-resolution structural analysis recently. Thus, now we are trying to get high-resolution structures of both V1 and VoV1 (intact enzyme) using a cryo-electron microscope (Titan Krios) equipped with a direct electron detector (Falcon II). We prepared grids for cryo-electron microscopy using Vitrobot (FEI) with the recombinant V1 and the Vo solubilized by DDM. We used thin carbon-backing for Vo and collected the images from both samples using EPU (FEI). For the efficient data collection by EPU, we used Quantifoil R2/4 made by Mo with 200 mesh. It is known that the particles on the images by cryo-electron microscopy are subjected to a beam-induced movement and so we applied motion collection before the image processing by Relion. We will show the resulted structures and discuss about possible improvements to the technique. Images of the VoV1 holoenzymes C3-P-12 doi:10.1093/jmicro/dfv315

The chiral diamine (2R), (4R)-pentane-2,4-diamine (2R,4R-ptn) has been found efficiently to regulate the stereochemistry of the cobalt(III) complex [Co(edda)(2R,4R-ptn)]+(edda = ethylenediamine-N,N′-diacetate). The product ratio Λ-sym-cis:Δ-sym-cis is 3:97. The stereoselectivity is surprisingly high in comparison with that for the analogous complex involving (1R),(2R)-cyclohexane-1,2-diamine (R,R-chxn), Λ-sym-cis:Δ-sym-cis= 60:40. It is discussed on the basis of crystal structure determinations carried out for both diastereoisomers of sym-cis-[Co(edda)(2R,4R-ptn)]+. A notable difference was observed in the six-membered chelate ring of 2R,4R-ptn which adopts the chair conformation in Λ-sym-cis-[Co(edda)(2R,4R-ptn)]ClO4·H2O 1a but the λ skew-boat conformation in Δ-sym-cis-[Co(edda)(2R,4R-ptn)]ClO41b. The chair conformation in 1a is due to steric repulsions between the chelates, which is the important factor for the preferential formation of 1b over 1a. Such steric repulsions between the chelates are remarkably efficient for the chiral six-membered chelate compared with those for the five-membered one. N-Alkyl substitutions on the edda ligand caused preferential formation of the Λ-sym-cis form, as is the case for the [Co(R2edda)(R,R-chxn)]+ system.

Compound 2, corresponding to the B/C/D-ring for aphidicolane-type diterpenes, was synthesized stereoselectively from a perhydroindane derivative (3) which was obtained by rhodium-alumina catalyzed hydrogenation of an indane ester (4) as a key step.

Cacao beans are composed of cacao nibs and germs. Although numerous chemical and physiological studies on cacao nib compounds have been reported, there is little information on cacao germ compounds. We therefore analyzed an extract from the cacao germ, and found two compounds that were specific to the germ. One of these two compounds was identified as the new glycosylated abscisic acid metabolite, dihydrophaseic acid-4′-O-6″-(β-ribofuranosyl)-β-glucopyranoside, and the other as the known compound, dihydrophaseic acid-4′-O-β-D-glucopyranoside.

NimA-related kinase 6 (NEK6) has been implicated in microtubule regulation to suppress the ectopic outgrowth of epidermal cells; however, its molecular functions remain to be elucidated. Here, we analyze the function of NEK6 and other members of the NEK family with regard to epidermal cell expansion and cortical microtubule organization. The functional NEK6-green fluorescent protein fusion localizes to cortical microtubules, predominantly in particles that exhibit dynamic movement along microtubules. The kinase-dead mutant of NEK6 (ibo1-1) exhibits a disturbance of the cortical microtubule array at the site of ectopic protrusions in epidermal cells. Pharmacological studies with microtubule inhibitors and quantitative analysis of microtubule dynamics indicate excessive stabilization of cortical microtubules in ibo1/nek6 mutants. In addition, NEK6 directly binds to microtubules in vitro and phosphorylates β-tubulin. NEK6 interacts and co-localizes with NEK4 and NEK5 in a transient expression assay. The ibo1-3 mutation markedly reduces the interaction between NEK6 and NEK4 and increases the interaction between NEK6 and NEK5. NEK4 and NEK5 are required for the ibo1/nek6 ectopic outgrowth phenotype in epidermal cells. These results demonstrate that NEK6 homodimerizes and forms heterodimers with NEK4 and NEK5 to regulate cortical microtubule organization possibly through the phosphorylation of β-tubulins.

Organization of microtubules (MTs) in relation to the behavior of nuclei was examined in dividing binucleate cells ofAdiantum capillus-veneris L. To induce binucleate cells, caffeine, an inhibitor of formation of the cell plate, was applied at 4 mM to synchronously dividing protonemal cells during cytokinesis (Murata and Wada 1993). Formation of the preprophase band (PPB) during the next cell cycle was examined in non-centrifuged and centrifuged cells. The two nuclei were separated or associated with one another in both non-centrifuged and centrifuged cells, although the location of the nuclei in the cylindrical protonemal cells was different (Murata and Wada 1993). Irrespective of centrifugation, a single PPB was formed around the nuclei in cells with associated nuclei. Two PPBs were formed in cells with separated nuclei in centrifuged cells. Patterns of mitosis and cytokinesis varied, depending on the location of the PPB and the distribution of the nuclei. The role of the nucleus in formation of the PPB is discussed.

Coordination of karyokinesis of two nuclei in individual filamentous binucleate cells of the fern,Adiantum capillus-veneris was investigated. To induce binucleate cells, the protonemata were treated with caffeine, which is known as an inhibitor of plant cytokinesis, during the first synchronous division of cells that was induced by blue light (BL). The next synchronous division of cells in the resultant binucleate cells was analysed.

The mixed-metal sulfide cubane-type cluster complex [PdMo 3 S 4 (tacn) 3 Cl][PF 6 ] 3 ( 1 ; tacn = 1,4,7-triazacyclononane) was found to be a highly efficient and selective catalyst for the addition of carboxylic acids to acetylenes with electron-withdrawing groups. The corresponding trans addition products were exclusively obtained in good yields under mild reaction conditions in the presence of a catalytic amount of triethylamine.

We isolated a novel oxidized sorbicillin dimer (1) as yellowish amorphous powder from the fermentation broth of Trichoderma sp. USF-2690 strain isolated from a soil sample. The structure of the compound was determined by elucidation of spectroscopic evidence. The compound was revealed to possess a new carbon skeleton in the group of oxidized sorbicillin dimers and was named bisorbibetanone. The stereostructure of bisorbibetanone was analyzed on the basis of the spectral data. In 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging assay, bisorbibetanone gave an ED30 value of 62.5 μM after standing for 30 min.

The preprophase band (PPB) of microtubules (MTs), which appears at the future site of cytokinesis prior to cell division in higher plant cells, disappears by metaphase. Recent studies have shown that displacement of the endoplasm from the PPB region by centrifugation delays the disappearance of the PPB. To study the role of the endoplasm in the cell cycle-specific disruption of the PPB, the filamentous protonemal cells of the fern Adiantum capilius-veneris L. were centrifuged twice so that the first centrifugation displaced the endoplasm from the site of the PPB and the second returned it to its original location. The endoplasm, including the nucleus of various stages of mitosis, could be returned by the second centrifugation to the original region of the PPB, which persists during mitosis in the centrifuged cells. When endoplasm with a prophase nucleus was returned to its original location, the PPB was not disrupted. When endoplasm with a prometa-phase telophase nucleus was similarly returned, the PPB was disrupted within 10 min of termination of centrifugation. In protonemal cells of Adiantum, a second PPB is often formed near the displaced nucleus after the first centrifugation. In cells in which the endoplasm was considered to have been returned to its original location at the prophase/prometaphase transition, the second PPB did not disappear even though the initial PPB was disrupted by the endoplasm. These results suggest that cell cycle-specific disruption of the PPB is regulated by some factor(s) in the endoplasm, which appears at prometaphase, i.e. the stage at which the PPB is disrupted in non-centrifuged cells.

Land plants have distinct developmental programs in haploid (gametophyte) and diploid (sporophyte) generations. Although usually the two programs strictly alternate at fertilization and meiosis, one program can be induced during the other program. In a process called apogamy, cells of the gametophyte other than the egg cell initiate sporophyte development. Here, we report for the moss Physcomitrella patens that apogamy resulted from deletion of the gene orthologous to the Arabidopsis thaliana CURLY LEAF ( PpCLF ), which encodes a component of polycomb repressive complex 2 (PRC2). In the deletion lines, a gametophytic vegetative cell frequently gave rise to a sporophyte-like body. This body grew indeterminately from an apical cell with the character of a sporophytic pluripotent stem cell but did not form a sporangium. Furthermore, with continued culture, the sporophyte-like body branched. Sporophyte branching is almost unknown among extant bryophytes. When PpCLF was expressed in the deletion lines once the sporophyte-like bodies had formed, pluripotent stem cell activity was arrested and a sporangium-like organ formed. Supported by the observed pattern of PpCLF expression, these results demonstrate that, in the gametophyte, PpCLF represses initiation of a sporophytic pluripotent stem cell and, in the sporophyte, represses that stem cell activity and induces reproductive organ development. In land plants, branching, along with indeterminate apical growth and delayed initiation of spore-bearing reproductive organs, were conspicuous innovations for the evolution of a dominant sporophyte plant body. Our study provides insights into the role of PRC2 gene regulation for sustaining evolutionary innovation in land plants.