Estimation of the mechanical connection between apical stress fibers and the nucleus in vascular smooth muscle cells cultured on a substrate.

Actin stress fibers (SFs) generate intercellular tension and play important roles in cellular mechanotransduction processes and the regulation of various cellular functions. We recently found, in vascular smooth muscle cells (SMCs) cultured on a substrate, that the apical SFs running across the top surface of the nucleus have a mechanical connection with the cell nucleus and that their internal tension is transmitted directly to the nucleus. However, the effects of the connecting conditions and binding forces between SFs and the nucleus on force transmission processes are unclear at this stage.

Mechanics of wrinkle formation: micromechanical analysis of skin deformation during wrinkle formation in ultraviolet-irradiated mice.

Background/purpose: The mechanical aspects of wrinkle formation were studied in the dorsal skin of hairless mice.

Methods: Wrinkles were induced by irradiating with ultraviolet (UV) B for 10 weeks, while observing skin deformation during wrinkle formation. Changes in skin dimensions were also observed during the specimen excision process.

Estimation of single stress fiber stiffness in cultured aortic smooth muscle cells under relaxed and contracted states: Its relation to dynamic rearrangement of stress fibers.

For a quantitative analysis of intracellular mechanotransduction, it is crucial to know the mechanical properties of actin stress fibers in situ. Here we measured tensile properties of cultured aortic smooth muscle cells (SMCs) in a quasi-in situ tensile test in relaxed and activated states to estimate stiffness of their single stress fibers (SFs). An SMC cultured on substrates was held using a pair of micropipettes and detached from the substrate while maintaining its in situ cell shape and cytoskeletal integrity.

Synthesis of 3-(phenylazo)-1,2,4-triazoles by a nucleophilic reaction of primary amines with 5-chloro-2,3-diphenyltetrazolium salt via mesoionic 2,3-diphenyltetrazolium-5-aminides.

The reactions of a 5-chloro-2,3-diphenyltetrazolium salt with amines have been examined. In the presence of an inorganic base such as NaHCO(3), primary and secondary amines undergo a nucleophilic substitution to give the corresponding 5-aminotetrazolium salts. When triethylamine is used as a base, primary amines give 3-phenylazo-1,2,4-triazoles.

Contribution of actin filaments and microtubules to quasi-in situ tensile properties and internal force balance of cultured smooth muscle cells on a substrate.

The effects of actin filaments (AFs) and microtubules (MTs) on quasi-in situ tensile properties and intracellular force balance were studied in cultured rat aortic smooth muscle cells (SMCs). A SMC cultured on substrates was held using a pair of micropipettes, gradually detached from the substrate while maintaining in situ cell shape and cytoskeletal integrity, and then stretched up to approximately 15% and unloaded three times at the rate of 1 mum every 5 s. Cell stiffness was approximately 20 nN per percent strain in the untreated case and decreased by approximately 65% and approximately 30% following AF and MT disruption, respectively.

Novel method to evaluate the net wear volume of bag-filter by fly ash.

In order to study the wear of bag-filter by ash dust, sintered magnetite (Fe(3)O(4)) compact was used for counter material for sliding wear test. The precise amount of magnetite particles embedded into bag-filter was determined by a vibration sample magnetometer (VSM) measurement. It is found that net amount of wear of the bag-filter could be precisely determined by the magnetic measurement.

Cis double allylation of cyclopropenes using cyclopropylindium reagents.

The successive double allylation of cyclopropenes with allylindium sesquiiodide and allyl iodide proceeded with a cis-addition mode in the presence of other organometallics (e.g. Grignard reagent, cuprate, Et(2)Zn and Et(3)Al), giving the corresponding cis-diallylcyclopropanes in high yields.

Effect of actin filament distribution on tensile properties of smooth muscle cells obtained from rat thoracic aortas.

Tensile properties and actin filament distribution of rat aortic smooth muscle cells (SMCs) were measured in the same cells to correlate the mechanical properties of cells with their cytoskeleton. The cells freshly isolated from rat thoracic aorta with enzymatic dispersion (FSMCs), cultured cells (CSMCs), and CSMCs treated with cytochalasin D to disrupt their actin filaments (CSMCs-CYD) were stretched in a Ca(2+)- Mg(2+) -free Hank's balanced salt solution at 37 degrees C with an originally designed micro tensile tester. Some of CSMCs and CSMCs-CYD were fixed and stained with rhodamine phalloidin for actin filament after the tensile test while they remained attached to the tester.

Direct preparation of allylic indium(III) reagents from allylic alcohols via a reductive transmetalation of pi-allylnickel(II) with indium(I) iodide.

InI-mediated direct allylation of carbonyl compounds with allylic alcohols proceeded smoothly with catalytic amounts of Ni(acac)(2) and PPh(3) to give the corresponding homoallylic alcohols in high yields. Allylindium compounds were shown to be the real allylating agents in the present system. Substituted allylic alcohols gave branched homoallylic alcohols with syn-selectivity irrespective of the geometry of the starting allylic alcohols, whereas high anti-selectivity was observed when a bulky substituent is present in the allylic alcohols.

A new synthesis of pyrroles by the condensation of cyclopropenes and nitriles mediated by gallium(III) and indium(III) salts.

Gallium(III) and indium(III) halides were found to mediate the condensation of cyclopropenes and nitriles to give pyrrole derivatives in moderate yields. When excess nitrile was present, diazepine was also formed.

Control of diastereoselectivity in the crotylation and cinnamylation of aldehydes by the selection of ligands on allylic indium reagents.

Diastereoselective couplings of salicylaldehyde, anisaldehyde and 2-pyridylaldehyde with crotyl- and cinnamylindium reagents were studied. The syl/anti selectivity was found to depend largely on the ligands on the indium atom of the allylic indium reagents. A syn-selective cinnamylation of salicylaldehyde was realized by the combination of cinnamyl acetate and indium(I) iodide, whereas an anti-selective coupling with salicylaldehyde was achieved by the indium trichloride/aluminium-mediated cinnamylation.