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Chain dimension of polystyrenes diluted with low molecular-weight homologues in semi-dilute solutions was investigated, referring to the results for solutions in benzene and styrene monomer, and its concentration dependence was clarified by small-angle neutron scattering (SANS) with a “contrast-matching” method. The styrene monomer was found to act as a good solvent comparable to benzene. The polystyrene was confirmed to expand in the bulk “diluent” homologues having sufficiently low molecular-weights, and its concentration dependence of expansion factor, α, became weaker with increasing the degree of polymerization, NS, of the short “diluent” polymer. The critical NS value, NS,c, which is defined as the maximum value to give excluded volume effects, was much higher than the earlier theoretical prediction by de Gennes, i.e., N S , c ∼ N L 1 / 2 , where NL is the degree of polymerization of the long “solute” polymer. The power law exponent for NS-dependence of α seems to follow −1/16, rather than −1/8 predicted by the scaling, suggesting that screening blob size, ξ, can be scaled as ξ ∼ N S 1 / 2 , which is equivalent to the radius of gyration for the “diluent” polymers.

Structural changes of dispersed domains in immiscible polymer blends under steady shear flow are directly observed by using cone-plate and coaxial cylinder geometries to analyze the orientation angle and the detailed shape of the domains. It was observed that the orientation angle have rather broad distributions even at the high shear rate. The ellipsoidal domains are not ellipsoid of revolution. At a certain steady state, domains having larger volume than the average volume are more elongated in the flow direction than the smaller ones. Shear stress and first normal stress difference cannot be calculated from average shape of observed domains.

Flow-Induced Structure and Viscoelastic Properties of Poly(styrene- block -2-vinylpyridine)s Solutions near the Order–Disorder Transition

To investigate the inhibitory effect of cyclosporin A on p-glycoprotein function in peripheral nerves (VIIth, VIIIth and sciatic nerves).Male mdr1a(-/-) and mdr1a(+/+) FVB mice were used. Doxorubicin (30 mg/kg) was administered intravenously with or without i.p. administration of cyclosporin A (200 mg/kg). Vinblastine (5 mg/kg) was also administered intravenously with or without i.p. administration of cyclosporin A (200 mg/kg).Tissue concentrations of doxorubicin and vinblastine in peripheral nerves of the mdr1a(+/+) mice pretreated with 200 mg/kg cyclosporin A were significantly higher than those in the mdr1a(+/+) mice administered doxorubicin or vinblastine alone, suggesting that cyclosporin A inhibited the efflux pump function of p-glycoprotein in the peripheral nerves. In the mdr1a(-/-) mice, tissue concentrations of doxorubicin and vinblastine in peripheral nerves were also significantly higher than those in the mdr1a(+/+) mice administered doxorubicin or vinblastine alone. Based on these results, it is suggested that p-glycoprotein plays an important role in blood-nerve barrier function by preventing side-effects induced by neurotoxic drugs.When doxorubicin and vinblastine are co-administered with cyclosporin A, the patient should be carefully monitored because peripheral nerve disorders may be induced.

Domain structures and rheological properties of immiscible polymer blends composed of components having almost the same viscosities in a parallel-plate (PP) geometry are studied in comparison with those in a cone-plate (CP) geometry. Both steady states and transient states after step increase of shear rate are examined. At steady states. it was confirmed that the domain size becomes smaller inversely proportional to the distance from the center (i.e., shear rate) along the radial direction of PP, consistent with the data in CP compared at the same shear rate. The related rheological data are also consistent. At transient states after the step increase of shear rate, there was no apparent long-range interference in the transient behaviors undergoing in different time scales at different positions along the radial direction of PP. The structure change and the related excess stresses of immiscible polymer blends with the nearly same viscosities under shear flow in PP are consistent with those in the CP geometry.

Purpose: The aim of the present study was to identify genes regulated in the early response to heat-shock in human head-and-neck cancer cells using a cDNA array. Methods and Materials: IMC-3 cells were heat-shocked at 44°C for 30 min, then incubated for 6 h. After 6 h incubation, mRNAs were extracted. Early gene expressions in IMC-3 cells were analyzed using a cDNA array after heat-shock. In addition, reverse transcription-polymerase chain reaction (RT-PCR) was performed to identify the expressions of mRNA for confirming features by cDNA array analysis in several other cell lines (KB, T3M-1, SCC-TF) as well as in IMC-3 cells. Results: Twenty-eight genes were found to be induced or upregulated by heat-shock in IMC-3 cells. These included genes involved in the apoptosis (e.g., CC3 , caspase10 ), tumor invasion (e.g., CC3 , TIMP-3 ), cell cycle checkpoint control (e.g., DP-1 , CDC25A ), signal transduction (e.g., MEK1 ) as well as genes associated with heat stress (e.g., Hsp70B ′, Hsp40 ). Gene expressions of CC3 and MEK1 were recognized to be induced by heat-shock in pharyngeal cancer cells (KB, T3M-1) and lingual cancer cells (SCC-TF). Conclusion: The observed alteration in gene expression may play a role in various biochemical pathways of cancer cells exposed to heat-shock.

Ventilation of the paranasal sinuses has been hypothesized to be a critical factor in curing rhinosinusitis, because blockage of the ventilating sinuses can lead to retention of nasal discharge or pus. In this report, we investigated the effect of treatment to clean and widen the middle nasal meatus in outpatients with rhinosinusitis. The outpatients were assigned to two groups: in the first group, cotton wool soaked with epinephrine was applied to the middle nasal meatus for 10minutes after cleaning the meatus at each consultation; in the second group, noepinephrine was used but the other conditions were the same. The treatment results were analyzed using X-rays, and subjective complaints via a the questionnaire survey, and nasal symptoms and X-rays scores were significantly better in the first group compared to the second group (p

Flow-induced phase separation behavior of poly (α-methylstyrenes) in a θ solvent, n-undecyl anisitate and the related viscoelastic properties were studied by rheological and light scattering measurements. The critical shear rate for flow-induced phase separation was consistently determined from integrated intensity of light scattering under the flow and its change after the cessation of flow, as well as from time dependency of dynamic modulus measured after the cessation of flow. It was observed that first normal stress difference and excess shear stress are proportional to shear rate at the shear rate region higher than the critical ones for phase separation. These results are qualitatively consistent with the theories of Onuki (Phys. Rev. A, 35, 5149 (1987)) and Doi and Ohta (J. Chem. Phys., 95, 1242 (1991)). The relative magnitude of excess stresses can be explained if we assume existence of domain structure elongated in the flow direction. At the higher shear rate end of measurement, it was observed that the stresses become not stable and show tendency to diverse. Together with direct observation results of the sample under the flow, it was speculated that the flow-induced gelation occurred at such high shear rates.

cDNAアレイは近年急速に発達している分野であり, 数百から数千以上の遺伝子発現を解析することができる手法である。今回我々はヒト上顎癌細胞株IMC-3における低pH条件下での温熱刺激による遺伝子発現の変化を, cDNAアレイを用いて解析した。さらにRT-PCRを行いその結果を検証した。低pH条件下での温熱刺激で18種の遺伝子の発現が増加していた。これらの中にはアポトーシスに関連する遺伝子と同様に, 細胞周期制御やシグナル伝達に関係する遺伝子が含まれていた。低pHの条件は温熱による細胞死誘導を増感させる効果があるが, 今回発現の変化が観察された遺伝子群がこの増感効果に関係がある可能性が示唆された。

Objectives The present study compares the long-term follow-up results of electrogustometry with patient reports of taste dysfunction after middle ear surgery. Study Design Retrospective review of 371 patients who underwent middle ear surgery. Methods Patients were divided into the following groups depending on the degree of manipulation or surgical damage to the chorda tympani nerves: the no-touch group (group 1 [n = 109]); the touch group (group 2 [n = 149]); and the severed nerve group (group 3 [n = 113]). Electrogustometry was periodically performed over the course of several years. Results The incidences of postoperative subjective taste disorder in groups 1, 2, and 3 were 2.8%, 25.5%, and 38.9%, respectively. Although the subjective taste disorder usually recovered within 1 to 2 years after surgery in all groups, it persisted for more than 2 years in 2.7% of the touch group and 5.3% of the severed nerve group. Concerning postoperative electrogustometric results, in the no-touch group, 8.3% of patients showed threshold elevation on electrogustometry, but the elevated thresholds completely recovered in all cases. In the touch group, 45% of patients exhibited elevated electrogustometric thresholds on their first postoperative test, including 32.9% who subsequently had complete electrogustometric recovery, 10.1% who subsequently had incomplete recovery, and 2% who failed to recover during the follow-up period. In the severed nerve group, none of the patients was responsive to the electrical stimulus on the first postoperative test, including 8.8% of patients who subsequently exhibited complete electrogustometric recovery, 32.7% who later had incomplete electrogustometric recovery, and 58.4% who never recovered any electrogustometric responsiveness. Nerve repair in the severed nerve group produced better recovery, as measured electrically. Conclusions The incidence of postoperative subjective taste disorder was low, although inconsistent with the high incidence of threshold elevation on electrogustometry, especially in the severed nerve group. Preservation or repair of the chorda tympani nerve is recommended in order to maintain or recover gustatory function.

Expression of p-glycoprotein (p-gp) and multidrug resistance protein 1 (MRP1) was detected in the vestibular labyrinth and endolymphatic sac (ES) of the guinea pig by immunohistochemical staining using anti-p-gp monoclonal antibody (mAb) C219 and anti-MRP mAb MRPr1. P-gp was detected in capillary endothelial cells of the crista ampullaris, utricle, saccule and ES. MRP1 was detected in the epithelial lining of the crista ampullaris, utricle, saccule, and epithelial cells of the ES. Since p-gp and MRP1 act as extrusion pumps, they may coordinate with each other in vestibular organs and ES and play an important role in the blood-labyrinth barrier.

We investigated the expression and function of mdr1a p-glycoprotein in peripheral nerves, including the VIIth and VIIIth nerves, using mdr1a p-glycoprotein gene knockout mice [mdr1a(-/-) mice] and wild-type mdr1a(+/+) mice. P-glycoprotein expression in capillary endothelial cells of the peripheral nerve tissues was detected by immunohistochemical and RT-PCR analyses in mdr1a(+/+) mice but not in mdr1a(-/-) mice. Pharmacokinetic analyses indicated that, compared to mdr1a(+/+) mice, mdr1a(-/-) mice showed a significantly higher accumulation of p-glycoprotein substrate drugs such as vinblastine and doxorubicin, which are neurotoxic. Tissue concentrations of vinblastine and doxorubicin were lower in the order of the brain, peripheral nerves and most other organs. However, increased accumulation was not detected after administering another neurotoxic drug, cisplatin, indicating that p-glycoprotein is selective at extruding drugs. These data indicate that mdr1a p-glycoprotein, which acts as an efflux pump, might play an important role in the blood-nerve barrier to prevent side effects induced by neurotoxic p-glycoprotein substrate drugs. The participation of p-glycoprotein in the blood-nerve barrier is considered to represent a new functional mechanism of this barrier.

CDDPは, 頭頸部癌化学療法の中心的役割を担う薬剤であるがその耐性は深刻な問題である。CDDPの抗腫瘍効果を増大する目的で, 親株とCDDP耐性株に対し, CDDPとイソチオシアネート誘導体 (hITC) との併用効果を検討した。両剤の併用効果が観察され, それはアポトーシスの増大によるものであった。細胞内シグナルの観点からは, p53依存的にも非依存的にもアポトーシスが誘導され, p53以外にはSAPK/JNKの関与が考えられた。hITCの併用により, CDDP感受性の増大と耐性の克服が示唆された。

Although doxorubicin [adriamycin (ADM)] ototoxicity has not been detected to date, it has been reported that neurotoxicity in the central nervous system was induced by chemotherapy with ADM in patients receiving chronic cyclosporin A (CsA) treatment. ADM ototoxicity may be induced by combination therapy with CsA because extrusion of ADM from the inner ear by p-glycoprotein (p-gp), which acts as an extrusion pump and is expressed on the surface of endothelial cells of capillary blood vessels, might be inhibited by CsA. resulting in significant accumulation of ADM in the inner ear. ADM (10 mg/kg) was administered to FVB mice either with or without CsA (200 mg/kg). Auditory brainstem responses (ABRs) were recorded before and after treatment. ABR changes were not observed in mice treated with either ADM or CsA alone. Threshold elevation, elongation of wave I-V latencies and interpeak latencies of waves I-II, I-III, I-IV and I-V were detected in mice treated with ADM in combination with CsA. These changes reached their peak values 3 weeks after treatment, and then recovered to pre-treatment levels. In normal mice, ADM is extruded by p-gp from the inner ear and auditory pathway, thus preventing hearing disorder. However, ADM ototoxicity was induced by combination therapy with CsA, indicating that CsA has an inhibitory action on p-gp function in the auditory pathway, including the inner ear. After organ transplantation, therefore, clinical administration of ADM in combination with CsA should be performed with caution.

Granulocyte colony-stimulating factor (G-CSF), a hematopoietic cytokine, regulates the proliferation and differentiation of granulocytic progenitor cells and functionally activated mature neutrophils. G-CSF also affects nonhematopoietic tumor cells through its binding to the specific receptor (G-CSFR) on the cells. The type IV collagenase [matrix metalloproteinase 2 (MMP-2)] is known to play a main role in the process of invasion and metastasis, but its regulation, for example, in expression or in activation, is not clearly understood. In this study, we investigated the role of G-CSF in the regulation of tumor cell invasion and the synthesis of MMP-2. G-CSFs producing the head and neck carcinoma cell line T3M-1 cells with metastatic ability and no G-CSF receptor (G-CSFR) expression were transfected with G-CSFR expression vector. In vitro treatment of G-CSFR-transfectant T3M-1 cells with recombinant G-CSF (rG-CSF) significantly augmented their invasive potential in a reconstituted basement membrane (Matrigel) system compared with that of parental cells. Moreover, MMP-2 activity of G-CSFR-transfectant T3M-1 cells was enhanced by the stimulation with rG-CSF, as assessed by gelatin zymography. These results identify G-CSF as a regulator of MMP-2 and cellular invasion.

Effective flow conditions for making fine structure of a model immiscible polymer blend, i.e., equiviscous immiscible polymer blend was examined by using interrupted flow and combination of step increase and decrease of shear rate. Overshoot peak of first normal stress difference, which corresponds to the existence of most elongated domains, was used as an indicator for changing shear rate. That is, shear rate was decreased (including zero shear rate) just after the overshoot peak of first normal stress difference appeared. Time needed to rupture the elongated domains and also droplet size and distributions thus obtained were compared to the data evaluated by using shear flow with step increase of shear rate. The time needed to rupture the domain with interrupted flow and combination of step increase and decrease of shear rate was shorten to be one fifth and the size of domains and their distribution were almost the same compared to corresponding data for flow with step increase of shear rate. It was concluded that decreasing of shear rate at the most elongated state of domain structure is an effective procedure to make fine structure of immiscible polymer blends.

Recently, endoscopic endonasal surgery has been widely used to treat chronic sinusitis with good results being reported by many investigators. Endoscopic endonasal surgery is a technique available not only for chronic sinusitis but also for other sinus diseases including postoperative maxillary mucoceles. In this report, the indications and limitations of endoscopic endonasal surgery for the treatment of postoperative maxillary mucoceles are discussed based on our experience treating 26 such mucoceles at our clinic. The indications for endoscopic endonasal surgery include mucoceles in close contact with the lateral wall of the inferior nasal meatus and those mucoceles that can be widely opened to the middle nasal meatus. The following cases could not be treated by endoscopic endonasal surgery: mucoceles that were localized in areas distant from the nasal cavity, mucoceles in which the lateral wall of the inferior nasal meatus was bony and intensely thickened, and mucoceles that could not be sufficiently opened to the middle nasal meatus.

Potentiometric titration of aliphatic α,ω-diamines such as 1,3-, 1,4-, and 1,6-diamines was carried out in aqueous solutions with and without added salt to study the effect of electrostatic interactions on the chain conformations. The ratios of first to second association constants of proton K1/K2 Were larger than 4 indicating the effects of electrostatic interactions on the second association constant in a similar manner as α,ω-diacids. These data were analyzed by the theories of Bjerrum and Kirkwood–Westheimer, and the resulting charge distances were compared with the end-to-end distances of various chain models.

Poly(2-vinylpyridine) (P2VP) with cyclic structure was tentatively prepared through the reaction of linear P2VP having two living ends followed by coupling with a bifunctional coupling agent. Thus, prepared crude product was fractionated by preparative size exclusion chromatography in order to enrich the cyclic polymer portion. Then the existence of the ring structure in the fractionated P2VP sample was directly confirmed for the first time by pyrolysis−gas chromatography/mass spectrometry by detecting the characteristic fragments reflecting the coupling moiety of the polymers at which the coupling agent combined the living 2VP units at both functional points.

Chain dimensions of polystyrenes diluted with benzene, styrene monomer, and low molecular weight homologues were measured by small-angle neutron scattering. Polystyrenes were confirmed to be expanded in monomer and in the homologues having sufficiently low molecular weights when polymer concentrations are low, and the concentration dependence of the expansion factor gets weaker with increasing degree of polymerization, N S , of “diluent”. The critical N S value, N S,c , which is the maximum value to give the excluded volume effects, is much higher than the theoretical prediction, N S,c ≈ N L 1/2 , where N L is the degree of polymerization of the “solute” polymer.

13 C NMR Relaxation of iso-Poly(2-vinylpyridinium chloride) in Aqueous Solution. Effects of Electrostatic Interactions on Local Chain Dynamics

Measurement of 13C spin-lattice relaxation times, T1, and nuclear Overhauser effects, NOE, was made as a function of temperature at two magnetic fields for poly(t-butyl crotonate), PTBC, and poly(t-butyl methacrylate), PTBM, in toluene-d8 to study the effects of β-substitution on local chain motions. For main chain carbons of PTBC and PTBM, experimental T1 and NOE data were well reproduced by the Dejean–Laupretre–Monnerie (DLM) model in the entire temperature range. The model parameters thus obtained differed between PTBC and PTBM. For methyl carbons in the t-butyl ester group, the experimental data were analyzed by the models combining the DLM model and multiple internal rotations. The model parameters were almost the same for the two polymers. These results indicate that β-substitution affects the local motion of main chains as well as chain stiffness, but does not significantly affect the local motion of methyl carbons at the ends of side-chains. The correlation between the local dynamics of various polymer chains and chain stiffness is discussed.

Tunicamycin (TM), a naturally occurring antibiotic, blocks the first step in the biosynthesis of N-linked oligosaccharides in cells. In this study, we investigated whether changes in N-linked glycosylation affect the sensitivity of head-and-neck carcinoma cell lines to cis-diaminedichloroplatinum(II) (cisplatin) in vitro and in vivo. In vitro treatment of the IMC-3 and KB cell lines with TM significantly decreased the 50% inhibitory concentration (IC50) of cisplatin, as determined by the MTT assay (24.15 to 10.97 microg/ml, p 100 to 14.4 microg/ml, p < 0.05) to levels similar to those against parental IMC-3 cells. TM treatment decreased the number of Con A- and L-PHA-binding sites on the surface of tumor cells but had no effect on the intracellular platinum concentration. Induction of apoptosis in vitro by TM plus cisplatin in combination was increased compared with that by cisplatin alone. Furthermore, in vivo administration of TM plus cisplatin in combination significantly inhibited local tumor growth in the cisplatin-resistant in vivo C3H/He mouse model as compared with the control group (p < 0.05) and increased in vivo apoptosis of tumor cells. Our results suggest that the manipulation of glycosylation by TM in tumor cells might be a useful therapeutic strategy for successful chemotherapy using cisplatin against head-and-neck cancer.

Viscoelastic properties of immiscible polymer blends consisting of polystyrene and poly(2-vinylpyridine), both of which have almost the same viscoelastic properties are studied under steady shear flow in linear and non-linear regions for the viscoelastic properties of components. It was observed that shear rate dependence of shear viscosity of blend samples was the same as those of component homopolymers, implying that the excess shear stress is proportional to the shear rate in the linear and non-linear regions for component polymers. It was also observed that the excess first normal stress difference of the blends was also proportional to the shear rate. It is concluded that the scaling relations between the excess stresses and the shear rate observed for binary immiscible polymer blends consisting of components with similar Newtonian viscosities can be extended into the higher shear rate regions where the components show similar non-linear viscoelastic behaviors.

The steady shear rate dependence of the structure of two poly(styrene-d8-b-2-vinylpyridine)s in α-chloronaphthalene, a common good solvent, was measured by small-angle neutron scattering (SANS) in a couette flow cell geometry in the ordered state, in which the solutions assume a lamellar structure (randomly oriented grains). SANS measurements revealed that steady shear flow induces macroscopic lamellar orientation at certain characteristic shear rates for the higher molecular weight sample (M w = 3.6 × 10 5 ). Lamellar normals are preferentially oriented along the vorticity direction at high shear rates. However, no shear effect was observed for the low molecular weight sample (M w = 2.0 × 10 5 ).

Sodium periodate (IO 4 ) exerts a number of biological effects including the enhancement of lymphocyte activation. In this study, we investigated its effects on cytotoxicity of human peripheral blood lymphocytes (PBL) and explored the mechanism whereby it exerted these effects. In vitro treatment of human PBL with IO 4 augmented their cytotoxicity against K562 myelogenous leukemia cells. IO 4 oxidative treatment increased the frequency of effector-to-target cell binding. It also increased cellular ATP levels in effector cells, suggesting that the post-binding cytolytic functions of these cells were also enhanced after treatment with IO 4 . Moreover, IO 4 treatment significantly increased the protein kinase C (PKC) activity of effector cells and induced the translocation of activity in the membrane fraction from the cytosol. H-7, a potent PKC inhibitor, significantly reduced this enhancement of membrane-associated PKC activity at 10 μ M and significantly reduced the enhanced cytotoxicity of PBL at the same concentration. These results indicated that IO 4 enhanced the binding capacity and post-binding cytolytic functions of PBL and that PKC activation was one mechanism to explain the IO 4 -induced cellular activation.

Order-disorder transitions (ODT) of symmetric poly(styrene-b-2-vinylpyridine) in a common good solvent and bulk were determined by dynamic rheological and small-angle neutron scattering measurements. ODT conditions determined by both methods are consistent with each other and the degree of polymerization dependence of critical volume fraction in solution at almost constant temperature agrees with the theoretical prediction for semidilute solutions. However, semidilute behavior persists to a much higher concentration than for ordinary polymer solutions and the crossover from semidilute to concentrated regimes is not clear.

CD40はB細胞上に存在し, T細胞上などのCD40-ligand (CD40L) と結合し, B細胞の増殖, クラススイッチを含む分化, 生存に関するシグナルが伝達される。さらにこのシグナルはアポトーシスに関連があるシグナルとされてきた。そこで今回B細胞以外にも頭頸部癌細胞株でCD40が存在しないかどうか, フローサイトメトリーを用いて検討してみた。IMC-2, IMC-3, KB, HTC/C3, CA-19.9の5つの細胞株の中で甲状腺癌由来のHTC/C3だけがCD40陽性であった。そこで抗CD40抗体を培養系に添加してCD40を刺激してみると, HTC/C3のコロニー形成が, 抗CD40抗体濃度依存性に抑制した。一方CD40陰性であった他の細胞株に抗CD40抗体を添加しても全く影響を及ぼさなかった。抗CD40抗体はHTC/C3に対する殺細胞効果はなかったが, Bcl-2を誘導するとともに, 抗Fas抗体によるアポトーシスを抑制した。さらにBcl-2のアンチセンスオリゴを導入すると, 抗CD40抗体の作用は解除された。つまり抗CD40抗体によるHTC/C3細胞増殖抑制は, Bcl-2のG1 arrest によるものであることが判明した。臨床的に成長がゆっくりな甲状腺癌由来の細胞にのみCD40が陽性であったことは, 非常に興味深いと思われた。

Although platysma myocutaneous flap (PTMCF) is suitable for a small intraoral defect, combination with neck dissection (ND) decreases the viability. Therefore, a version of PTMCF was devised to increase the viability. This version consists of three points: preservation of the external jugular vein (EJV), preservation of the facial artery after skeletonization from the submandibular gland, and a new incision around the flap. This procedure was applied to 21 patients with intraoral cancer. All 21 patients underwent some kind of ND. The average viable area of transferred skin was 80%. This rate was significantly better than that for 46 previous cases using Farr’s modification with ND, in which the facial artery was divided. Viability of the flaps was analyzed by the vessels preserved, especially by EJV. ND is not a contraindication with this version.

The critical shear rate for flow-induced homogenization of a polystyrene/poly(vinyl methyl ether) blend with nearly critical composition in the phase-separated region near the phase separation temperature was studied by rheological and light scattering measurements under steady shear flows. The critical shear rate by rheometry was determined from the change in shear rate dependence of first normal stress difference as in a previous study. This critical shear rate was almost consistent with the critical shear rate by flow-light scattering at which the intensity deviates from the value in the phase-separated region.

We examined chain degradation in rheological measurements and the effects of molecular weight distributions (MWDs) on rheological data at steady states for polystyrenes in dioctyl phthalate undergoing flow-induced phase separation. The chain degradation occurred when we observed a strong overshoot in transient stresses. The suppression of overshoot by lowering the concentration and the molecular weights of the samples, and/or by making a step increase in the shear rate, was effective in preventing the degradation. The most significant difference between the rheological data for samples with broad and narrow MWDs is the existence of plateau in the first normal stress difference in the former. Shear rate dependences of the stresses of broad MWD samples in the shear rate range before the plateau are somewhat steeper than those of narrow MWD samples.

Rheological properties of three immiscible polyisoprene (PI)/polydimethylsiloxane (PDMS) blends (PI:PDMS=1:9 by weight) having viscosity ratios ηd/ηm=0.155, 0.826, and 4.02, where ηd and ηm are the viscosities of the droplet and matrix, were investigated by directly measuring the droplet size distributions with a video microscope. Steady state measurements were performed by sequentially stepping up the shear rate γ (step-up) and step decrease (step-down) of the shear rate. Dynamic frequency sweep measurements were also performed immediately following cessation of steady shear flow. In the step-up measurements for blends with ηd/ηm=0.155 and 0.826, stresses were proportional to γ and the droplet sizes were well regulated by the flow and inversely proportional to γ for γ⩾0.553 s−1, in good agreement with the Doi–Ohta model [J. Chem. Phys. 95, 1242–1248 (1991)]. The results of step-down measurements were consistent with dynamic moduli measurements, because the droplet sizes were almost unchanged during these measurements. The results are in accord with Palierne’s model [Rheol. Acta 29, 204–214 (1990)]. For the ηd/ηm=4.02 blend, however, the droplet sizes were insensitive to γ, resulting in worse agreement between the experimental and theoretical results than for the other blends.Rheological properties of three immiscible polyisoprene (PI)/polydimethylsiloxane (PDMS) blends (PI:PDMS=1:9 by weight) having viscosity ratios ηd/ηm=0.155, 0.826, and 4.02, where ηd and ηm are the viscosities of the droplet and matrix, were investigated by directly measuring the droplet size distributions with a video microscope. Steady state measurements were performed by sequentially stepping up the shear rate γ (step-up) and step decrease (step-down) of the shear rate. Dynamic frequency sweep measurements were also performed immediately following cessation of steady shear flow. In the step-up measurements for blends with ηd/ηm=0.155 and 0.826, stresses were proportional to γ and the droplet sizes were well regulated by the flow and inversely proportional to γ for γ⩾0.553 s−1, in good agreement with the Doi–Ohta model [J. Chem. Phys. 95, 1242–1248 (1991)]. The results of step-down measurements were consistent with dynamic moduli measurements, because the droplet sizes were almost unchanged during t...

Lamellar domain spacings (D) of blends of a styrene-2-vinylpyridine (SP) diblock copolymer and homopolymers corresponding to the block polymers (S and/or P), of which molecular weights are lower than that of the block polymer, were examined by small-angle X-ray scattering (SAXS), and the dimensions of block chains in the lamellae were investigated by small-angle neutron scattering (SANS). The D's for SP/S/P ternary and SP/S (or SP/P) binary blends increase with increasing the molecular weight of the homopolymers, MH, as well as the volume fraction of the homopolymers, ΦH, in the corresponding lamella. The variations of the D's with ΦH for the blends with homopolymers having different MH's reveal that homopolymers with higher MH are localized at the center of the corresponding lamella, while those with lower MH are distributed throughout the lamella. Moreover, the comparison between the D's for ternary and binary blends with homopolymers having equal MH's implies that the homopolymers in binary blends are ...

Expression of P-glycoprotein (P-gp) was detected by immunohistochemical staining and Western blot analysis in the peripheral nerves (7th and 8th nerves) of the guinea pig using anti-P-gp monoclonal antibody C219. P-gp was detected in the capillary endothelial cells of these nerves. Immunoreactivity in these nerves was similar to that in the brain. Besides these nerves, positive staining was observed in the sciatic nerve, although immunoreactivity was somewhat lower than that of the 7th and 8th nerves. The present investigation suggested that P-gp in the endothelial cells of the peripheral nerves might play a very important role as a part of the blood-nerve barrier function, since P-ag acts as an extension pump in these cells.

Segment distribution of styrene in an alternating lamellar structure of styrene−2-vinylpyridine diblock copolymer was investigated by neutron reflection. Block copolymers having three types of deuterium-labeled styrene block chains consisting of fully labeled, partially junction-labeled, and partially end-labeled block chains were used in this study. The degree of junction and end labeling was varied to obtain a more complete picture of segment distribution. Spin-coated thin films of these block copolymers on silicon wafers exhibited lamellar structures which were oriented preferentially parallel to the silicon surface. Our results indicate that the poly(2-vinylpyridine) block chain exists at the silicon surface, while polystyrene appears at the air surface in all of the film specimens. The segment distribution at the interface between polystyrene and poly(2-vinylpyridine) lamellae could be well described by an error function. The thickness of the lamellar interface (defined as a full-width half-maximum v...

頭頸部悪性腫瘍の治療では, その機能と形態の保存上, CDDPを中心とした化学療法に対する期待が大きいが, 初回治療後に出現するCDDP耐性が, 化学療法の障害となっている。我々はヒト上顎癌由来細胞 (IMC-3) とそのCDDP耐性細胞 (IMC-3-DDP) を用いて40℃加温との同時併用効果を検討した。両細胞の40℃感受性は同等であった。40℃加温によって, IMC-3, IMC-3-DDP細胞のCDDP感受性は37℃に比べて, それぞれ1.48, 1.94倍に増強された。また細胞内Pt量は, 耐性細胞において親株の約6割に減少していたが, 40℃加温時のPt量は37℃に比べて, IMC-3で1.4倍, 一方IMC-3-DDP細胞では1.8倍と増加していた。CDDP感受性の40℃加温による増感効果は正感受性細胞より耐性細胞において大きく, またその程度は, 細胞内Pt量の変化を良好に反映していた。

The molecular weight dependence of lamellar domain spacing of poly(2-vinylpyridine-g-styrene) was measured by small angle X-ray scattering (SAXS). The samples used are six three-arm star-shaped polymers having one polystyrene arm connected at the centre of a poly(2-vinylpyridine) chain. The volume fractions of grafted polystyrene chains, ƒ s , of the samples range from 0.45 to 0.78, though all the samples were confirmed to have alternating lamellar structure by SAXS and transmission electron microscopy. It was found that the relationship between lamellar domain spading, D, and the molecular weight, M, of the graft copolymers is given by D = 0.0153 M0.69 (nm) over the molecular weight range from 49 to 283 k irrespective of the difference in composition. The exponent 0.69 is quite close to 2 3 , which is predicted for AB diblock copolymers by several different theories. However, the magnitude of the prefactor in the above relationship is apparently smaller than that for styrene-2-vinylpyridine diblock copolymers. This difference can be explained by considering the difference in structure between AB diblock copolymers and ABB graft copolymers.

Viscoelastic properties of poly(2-vinylpyridine) (P2VP) over a wide range of molecular weight (M) were studied in bulk and solution. It was found that the absolute values of zero-shear viscosity η0 of P2VP in bulk and in α-chloronaphtharene (αCN) are practically the same as those of polystyrene (PS) over whole experimental range of M. The temperature dependence of η0 in bulk is also the same. It is concluded that among various polymers so far studied, P2VP and PS have very similar viscoelastic properties in both bulk and a good solvent (αCN), though the plateau modulus GN0 and steady state compliance Je of P2VP are slightly different from those of PS.

Viscoelastic properties of non-entangled concentrated aqueous solutions of three sodium polystyrenesulfonates with low molecular weights were measured in oscillation flows. Master curves of dynamic moduli were obtained by shifting the moduli data measured at different concentrations along the frequency (ω) axis for each molecular weight. The concentration shift factor used in making the master curves composes a single line irrespective of molecular weight. Storage and loss moduli are proportional to ω 2 and ω, respectively, in the terminal region, while they are proportional to ω 1/2 in the transition region. All the master curves can be well represented by the modified Rouse theory using the experimental values of concentration, molecular weight and viscosity in a reference state.

Viscoelastic properties of polyelectrolyte solutions were studied in the absence and presence of added salt over a wide range of polymer concentration in comparison with those of non-ionic polymers in good solvents. In the semidilute region where the polymer concentration C is higher than the overlap concentration for viscosity C v * , but lower than C ** (ca. 0.3 kg/dm 3 ), the polymer concentration dependence of specific viscosity at zero-shear rate η 0 sp increases with increasing added-salt concentration C s and at high C s almost agrees with that of non-ionic polymers in good solvents. In the concentrated and entangled region where C>C J * and C>C ** , η 0 sp more steeply increases with C even in salt-free solutions, implying the screening of electrostatic interaction and the increase of local frictional coefficients as considered in concentrated non-ionic polymer solutions. In the dilute region where C is lower than the overlap concentration for steady-state compliance C J * , the steady-state compliance J e more strongly depends on molecular weight and C than in non-ionic polymer solutions. In the semidilute region where C>C J * , but C C J * and C>C ** , the polymer concentration dependence becomes similar to that of non-ionic polymer solutions. In the concentrated and non-entangled region where C C ** , the frequency dependences of storage and loss moduli are well explained by the modified Rouse model like non-ionic polymer systems in the same region. The experimental results in the semidilute region are well explained by our theory of viscoelastic properties of polyelectrolyte solutions based on the reptation model with electrostatic interactions.

We prepared well-defined styrene (S)-2-vinyl-pyridine (P) graft copolymers of the ABB type or SPP graft copolymers, in which as block chain is grafted at the center of a block chain, as a model graft copolymer by anionic polymerization and coupling reaction. The composition dependence of morphology of SPP graft copolymers is qualitatively the same as that of SP diblock copolymers, but the composition range of each structure is shifted to the higher volume fraction of S block chain. The molecular weight dependence of lamellar domain size of SPP graft copolymers is almost the same as that of SP diblock copolymers, but the magnitudes are smaller. These experimental results are well explained by the difference in chain architectures.

Poly(2-vinylpyridine-g-styrene)s were prepared by successive coupling reactions of polystyryl anion and poly-2-vinylpyridinyl anion prepared by anionic polymerizations, with trifunctional coupling agent, tris-bromomethylbenzene. Five samples were prepared and characterized. Their volume fractions of polystyrene graft,os, were determined to be 0.24, 0.34, 0.45, 0.58 and 0.67, respectively. Morphologies of the solvent-cast films of the samples were observed by transmission electron microscopy and small-angle X-ray scattering. It was revealed that two samples, with os of 0.24 and 0.34, show cylindrical structures, while the other three samples have alternating lamellar structures.

ヒト上顎癌細胞株における, rG-CSFの癌浸潤能に及ぼす影響を検討した。rG-CSFの添加により, 上顎癌培養細胞の浸潤能は培養時間およびrG-CSF濃度依存性に増大した。rG-CSFによるこの浸潤能増大は, 抗G-CSF抗体によって濃度依存性に抑制された。rG-CSFによる上顎癌浸潤増強効果, および癌細胞上のG-CSFレセプター存在の可能性が示唆された。