Surface melting and lamella rearrangement process in linear low density polyethylene.

The surface melting and lamella rearrangement process that happen in commercially available linear low-density polyethylene (LLDPE) were studied with special emphasis on conformational and crystal structural changes during the process. The thermal melting behavior of the specimens was examined by using differential scanning calorimetry and the occurrence of the surface melting was strongly suggested in low-crystallinity LLDPE (LLDPE-L) in the temperature range of 90-120 degrees C at the heating rate of 2 degrees C/min. The structural and conformational disordering process during heating was studied by IR spectroscopy combined with two-dimensional spectral correlation analysis. The formation of conformational defects has been determined to proceed prior to the overall disordering of orthorhombic crystalline structure in all the PE specimens except for LLDPE-L. During the heating process, conformational defects are preferably developed in side chains that are excluded from tightly packed orthorhombic crystal in PEs other than in LLDPE-L. The temperature dependency in the thickness of lamella layers of LLDPE-L examined by small-angle X-ray scattering indicates the occurrence of the lamella thickening in the temperature range where surface melting has been observed. In this way, the formation of new orthorhombic cells due to the lamella rearrangement dominates over the formation of conformational defects in LLDPE-L while other specimens indicate opposite. Wide-angle X-ray scattering shows significantly suppressed dilation of the unit cell in LLDPE-L, especially toward orthorhombic unit cell parameter a in the temperature range where lamella thickening process undergoes. It is implied that the lamella thickening happens not only by rearranging the chains originally exist in the interfacial region but also it incorporates those originally existing in the orthorhombic crystal phase in LLDPE-L. The heat-induced morphological changes are explored by means of polarized light microscope with liquid crystal universal compensator and circular polarizer (LC-PolScope). Unlike other PE specimen, high-crystallinity LLDPE (LLDPE-H) shows the retardance histogram with multiple peaks, indicating the presence of several types of higher order structure, such as aggregation within the specimen.

Expression of granulocyte colony-stimulating factor receptor correlates with prognosis in oral and mesopharyngeal carcinoma.

Granulocyte colony-stimulating factor receptors (G-CSFRs) have been observed on the surface of not only hematopoietic cells but also several cancer cells. The stimulation of G-CSF has been demonstrated to induce proliferation and activation of G-CSFR-positive cells. In this study, we investigated the expression of G-CSFR on the surface of tumor cells and G-CSF production in oral and mesopharyngeal squamous cell carcinoma (SCC) by an immunohistochemical approach. Of 58 oral and mesopharyngeal SCCs, 31 cases (53.4%) and 36 cases (62.1%) were positive for G-CSFR and G-CSF, respectively. There was no association between G-CSFR expression and G-CSF staining. In the group positive for G-CSFR expression, relapse was significantly more likely after primary treatment (P = 0.0069), whereas there was no association between G-CSFR expression and age, sex, tumor size, lymph node metastasis, and clinical stage. Also, the G-CSFR-positive groups had a significantly lower disease-free and overall survival rate than the G-CSFR-negative groups (P = 0.0172 and 0.0188, respectively). However, none of the clinical markers correlated significantly with G-CSF staining, nor did the status of G-CSF production influence the overall survival. The results imply that assessment of G-CSFR may prove valuable in selecting patients with oral and mesopharyngeal SCC for aggressive therapy.

Expression of hMSH2 correlates with in vitro chemosensitivity to CDDP cytotoxicity in oral and oropharyngeal carcinoma.

We investigated the expression of hMSH2, a human mutS homologue from chromosome 2p, in oral and oropharyngeal squamous cell carcinoma (SCC) by an immunohistochemical technique and performed tumor in vitro chemosensitivity testing. In 58 oral and oropharyngeal SCC, the hMSH2 positive score was inversely associated with tumor size, but not with other clinical parameters. Among five anticancer drugs (cisplatin (CDDP), 5-FU, peplomycin, mitomycin C and doxorubicin), only for CDDP was sensitivity to cytotoxicity correlated with the hMSH2 positive score. The susceptibility of hMSH2-positive tumors to CDDP killing was significantly higher than that of hMSH2-negative tumors. Immunohistochemical results regarding hMSH2 are promising in the evaluation of the sensitivity of cancer cells to CDDP cytotoxicity and enable one to select patients for adjuvant chemotherapy for oral and oropharyngeal SCC.

Transglycosylation activities of exo- and endo-type cellulases from Irpex lacteus (Polyporus tulipiferae).

Two highly purified cellulases, Ex-1 [exo-type, exo-cellobiohydrolase, EC 3.2.1.91] and En-1 [endo-type, EC 3.2.1.4] obtained from Driselase, a commercial enzyme preparation from Irpex lacteus (Polyporus tulipiferae), were used in this work. Both cellulases produced 14C-cellooligosaccharides such as 14C-G2 and 14C-G3 by transglycosylation when G3, G5, or beta-PNPC was used as a donor and 14C-G1 as an acceptor. However, the transglycosylation activity of Ex-1 was far higher than that of En-1. When Ex-1 or En-1 was incubated with beta-PNPG only, no p-nitrophenol was released, but it was readily released when G3 was added to the reaction mixture. In this reaction, the optimal donor (G3) concentration for Ex-1 was 1.0 mM, and the optimal pH values of Ex-1 were at 2.7 and 3.7 for beta-PNPG and beta-PG as acceptors, respectively, these values being far lower than the ordinary optimal pH values of the cellulase (4.0-5.0).

Expression of multidrug resistance protein 1 (MRP1) in the rat cochlea with special reference to the blood-inner ear barrier.

Expression of multidrug resistance protein 1 (MRP1) was detected in the rat cochlea by RT-PCR and immunohistochemistry using anti-MRP monoclonal antibody MRPr1. Use of primers specific for rat mrp1 gene resulted in the amplification of an expected 394 bp fragment prepared from brain and cochlear tissues. Immunohistochemically, MRP was found in the choroid plexus, stria vascularis, spiral ligament, spiral prominence and cochlear nerve in the modiolus. From these results, it was suggested that MRP in the rat cochlea might function as an extrusion pump and play an important role in the blood-inner ear barrier.

P-glycoprotein expression in capillary endothelial cells of the 7th and 8th nerves of guinea pig in relation to blood-nerve barrier sites.

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.

Expression of p-glycoprotein is associated with that of multidrug resistance protein 1 (MRP1) in the vestibular labyrinth and endolymphatic sac of the guinea pig.

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.

Light scattering from solutions of a semi-flexible polymer and a polyelectrolyte both having sharp molecular weight distributions.

The particle scattering factor in light scattering is determined for poly(tert-butyl crotonate) in n-butyl chloride and also for partially neutralized poly (acrylic acid) in aqueous solution in the presence of added neutral salt (NaBr). The former is a wormlike chain which is extended due to stiffness of the polymer chain, while the latter is extended due to the electrostatic repulsive force which is a kind of excluded volume effect. A clear difference is found between P(theta) of both polymers.

Applicability of the potentiometric titration method to the analysis of the expansion process of bovine plasma albumin in acidic solutions.

To study the expansion process of bovine plasma albumin in acidic solutions, observed potentiometric titration curves at three different ionic strengths were compared with theoretical curves, using the radii of the protein determined by small angle X-ray scattering (SAXS). From the comparison, it was concluded that the expansion is completed via two different transitions and that the conformation of the protein before the first transition is stable and common at all ionic strengths, whereas the form of the protein becomes a more swollen and unstable one after the first transition. Moreover, the charge-independent part of the standard free energy change, delta G0, in the first transition was estimated from the potentiometric titration curves. The numerical value of delta G0 is 2350 +/- 50 cal/mol, which is very small compared with the corresponding one for ordinary biopolymers.

Enhancement of sensitivity to CDDP in human pharyngeal carcinoma cells by H-7, a protein kinase inhibitor.

We investigated the synergetic effects of 1-(5-isoquinolinesulfonyl)-2-methylpiperazine dihydrochloride (H-7) on cis-diamminedichloroplatinum(II) (CDDP) cytotoxicity to KB cells, a human pharyngeal carcinoma cell line, and explored the possible mechanism whereby it exerted these effects. In vitro treatment with H-7 markedly decreased protein kinase C (PKC) activity in KB cells and significantly sensitized the cells to CDDP. Treatment of KB cells with H-7 induced a dose-dependent depletion of intracellular glutathione (GSH) levels. These results suggest that the decreased GSH content induced by H-7 may be involved in sensitizing KB cells to CDDP.

Relationship between cellular glutathione level and susceptibility to LAK killing in human pharyngeal carcinoma cell line.

We examined the relationship between cellular glutathione (GSH) level and susceptibility to lymphokine-activated killer (LAK) cell-mediated cytolysis in KB human pharyngeal carcinoma cells. Treatment of KB cells with D,L-buthionine-S,R-sulfoximine (BSO), a gamma-glutamyl cysteine synthetase blocker, resulted in decreased total intracellular GSH levels associated with increased susceptibility to LAK killing. In contrast, treatment with oxothiazolidine-4-carboxylate (OTZ, a precursor of cysteine), which is known to increase cellular GSH level, decreased the susceptibility of KB cells to LAK killing. Both agents had no effects on binding frequency of KB cells to LAK cells. These results suggest that intracellular GSH in tumor cells play a protective role against LAK mediated cytolysis, specially in the post-binding killing phase.

Effect of heat-drug sequences on thermoenhancement and uptake of cis-DDP in human pharyngeal carcinoma.

To discover the point of maximum interactive effect, we examined the time sequence of high (above (42.5 degrees C) or low (below 42.5 degrees C) -hyperthermia and cis-diammine dichloroplatinum (II) (CDDP). Simultaneous or post-hyperthermic CDDP (0.5 micrograms/ml) treatment at 43 degrees C resulted in a slight synergistic effect, with thermoenhancement ratios (TER) of 1.42 or 1.38, respectively, and there was a significant increase CDDP uptake after both combinations compared with pre-hyperthermic CDDP treatment. However, at 42 degrees C, the maximal interaction (TER = 8.57) was obtained when KB cells were simultaneously heated with CDDP, there was also a significant increase of CDDP uptake by simultaneous procedures compared with pre or post-hyperthermic CDDP treatment. These results indicate that simultaneous or post-hyperthermic CDDP treatment for high-hyperthermia and simultaneous CDDP treatment for low-hyperthermia are the most effective means of CDDP thermochemotherapy with hyperthermia.

Involvement of intracellular glutathione in induction of apoptosis by cisplatin in a human pharyngeal carcinoma cell line.

We investigated the effect of intracellular glutathione (GSH) levels on apoptosis in KB cells induced by cisplatin (CDDP). The mode of cell death, apoptosis or necrosis, was evaluated by biochemical and morphological criteria. The treatment of KB cells with D,L-buthionine-(S,R)-sulfoximine (BSO, a gamma-glutamyl cysteine synthetase inhibitor) decreased GSH level to 1/7th of that of control cells, and augmented cell death induced by CDDP via a necrotic rather than apoptotic process (the ratio of necrosis to apoptosis; n/a>14). In contrast, treatment with 2-oxothiazolidine-4-carboxylic acid (OTZ, a precursor of cysteine) increased GSH levels 1.7 fold compared with that of untreated cells, inhibited cell death induced by CDDP and switched the mode of cell death from necrosis to apoptosis (n/a<0.8, similar to untreated cells). These results suggest that the GSH level affects the cytotoxicity of CDDP and plays an important role in switching the mode of cell death induced by CDDP.

Long-term follow-up results of electrogustometry and subjective taste disorder after middle ear surgery.

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.

Swainsonine augments the cytotoxicity of human lymphokine-activated killer cells against autologous thyroid cancer cells.

OBJECTIVE: Swainsonine (SW), an inhibitor of mammalian Golgi alpha-mannosidase II, blocks the processing of high mannose to complex type oligosaccharides. In this study, the effect of SW on the cytotoxicity of lymphokine-activated killer (LAK) cells against autologous thyroid cancer was investigated. DESIGN: Peripheral blood lymphocytes from patients with thyroid cancer were incubated with recombinant interleukin 2 (100 U/mL) and 0.5 mg/L of SW for 7 days, and thyroid cancer cells obtained from surgical specimens were pretreated with SW (0.5 mg/L) for 18 hours. The cytotoxicity of SW-treated LAK cells against tumor cells tested in a standard 4-hour radioactive chromium Cr 51 release assay. RESULTS: The cytotoxicity of SW-treated LAK cells against autologous thyroid cancer cells was found to be significantly greater than that of standard LAK cells incubated with interleukin 2 alone. The N-alpha-benzyloxycarbonyl-L-lysine thiobenzyl ester esterase activity of LAK cells, this activity being a cytotoxic factor that is necessary for the lethal hit stage, was also increased by SW treatment. Further, thyroid cancer cells incubated with SW, as compared with nontreated tumor cells, showed much higher susceptibility to LAK killing. CONCLUSIONS: Our results suggest that SW might have potential immunomodulatory properties in the treatment of thyroid cancer.

Heat shock enhances the susceptibility of tumor cells to lysis by lymphokine-activated killer cells.

OBJECTIVE: To determine whether heat-treated thyroid cancer cells augment the susceptibility of target cells to lysis by autologous lymphokine-activated killer cells. DESIGN: Peripheral blood lymphocytes from patients with thyroid cancer were incubated with recombinant interleukin 2 (100 U/mL) for 7 days, and thyroid cancer cells obtained from surgical specimens were heated at 44 degrees C for 20 minutes and incubated at 37 degrees C for 18 hours before performing the radioactive chromium Cr 51 release assay. RESULTS: The susceptibility of heat-treated thyroid cancer cells to lysis by autologous and allogeneic lymphokine-activated killer cells was significantly greater than that of untreated tumor cells. The mechanism of enhanced susceptibility was unclear. However, the effect depended on de novo protein synthesis, because inhibition of RNA synthesis by dactinomycin completely abolished the heat-enhanced susceptibility of tumor cells. CONCLUSION: Immunotherapy combined with hyperthermia may be useful in management of thyroid cancer.

On the normalization method in two-dimensional correlation spectra when concentration is used as a perturbation parameter.

Data pretreatment is of importance in two-dimensional (2D) correlation analysis when composition is used as a perturbation parameter. For composition-oriented studies, different normalization methods based on both external parameters (i.e., concentration) and internal parameters (i.e., absorbance from individual components) have been compared. It was found that when there is no overlapping between absorption bands of interest, no normalization is needed for data pretreatment. When overlapped bands must be used for 2D correlation analysis, the mean-centered normalization method could be used to obtain correct signs in synchronous spectra for a transformation process in the specific form of A-->kC. The intensity of the 2D spectrum, however, may not accurately reflect quantitative information of the overall extent of spectral intensity variation observed during experiments.

Effects of sequence and temperature of hyperthermia and peplomycin on human pharyngeal carcinoma KB cells in vitro.

To maximize the interactive effect, we examined the time sequence of high (above 43 degrees C) or low (below 43 degrees C)-hyperthermia and peplomycin (PEP)(0.5 microgram/ml). Simultaneous or post-hyperthermic PEP treatment at 44 degrees C resulted in a slight synergistic effect with thermoenhancement ratios (TER) of 1.30 or 1.34, respectively. However, at 42 degrees C, maximal interaction was obtained (TER = 10.19) when KB cells were simultaneously heated with PEP. Furthermore, pre-treatment at 44 degrees C for 25 min or 42 degrees C for 4 h enhanced PEP cytotoxicity more than that of post-treatment at 44 degrees C for 25 min or 42 degrees C for 4 h, respectively. However, chemoenhancement ratios (CER) of pre-treatment at 44 degrees C for 25 min and at 42 degrees C for 4 h were 19.1 and 3.5, respectively, although the isothermic dose decreased the cell count to 60% in both cases. These results indicated that simultaneous or post-hyperthermic PEP treatment with high-hyperthermia, and simultaneous PEP treatment with low-hyperthermia, are the most effective means of PEP thermochemotherapy with hyperthermia.

Recent outcome of tympanoplasty in the elderly.

OBJECTIVE: To investigate the outcome of tympanoplasty in the elderly (patients older than 60 years) compared with younger patients. PATIENTS AND STUDY DESIGN: Retrospective review of 87 (28.3%) older patients among a total of 307 patients with chronic otitis media with or without cholesteatoma who were surgically treated at a university hospital by the senior author. Follow-up was systematically provided at the same institution. INTERVENTIONS: Surgery included tympanoplasty with mastoidectomy performed as the primary procedure in 358 ears. Tympanoplasty was performed with canal-wall-up or canal-wall-down with canal wall reconstruction, ossiculoplasty with autologous or homologous ossicle interposition or columella. Mean follow-up was 30 months (range, 12-70 months). MAIN OUTCOME MEASURES: Pre- and postoperative air- and bone-conduction thresholds were calculated as an average of three speech frequencies (0.5, 1, and 2 kHz). Analysis was subsequently carried out on the postoperative air-bone gap, hearing gain, and postoperative problems such as elevation of the bone-conduction threshold, delayed epithelialization, and reperforation of the eardrum. Statistical analysis was performed by chi-square or Student's t-test. A p value less than 0.05 was considered significant. RESULTS: Compared with results from younger patients, there was no particular disadvantage in postoperative hearing results and complications in the elderly, although preoperative bone-conduction thresholds were gradually worsened with age. CONCLUSIONS: There is no contraindication for tympanoplasty in older patients if their physical status is the same or better than what is normal for their chronological age.

Synthesis of high-molecular-weight poly([R]-(-)-3-hydroxybutyrate) in transgenic Arabidopsis thaliana plant cells.

High-molecular-weight poly([R]-(-)-3-hydroxybutyrate) (PHB), a biodegradable thermoplastic, was produced from a suspension culture of transgenic Arabidopsis thaliana plant cells expressing two genes from the bacterium Alcaligenes eutrophus involved in the synthesis of PHB. The molecular structure of the plant-produced polymer was analysed by gas chromatography, mass spectrometry, proton nuclear magnetic resonance spectroscopy, infra-red spectroscopy, spectropolarimetry, differential scanning calorimetry, X-ray diffraction and size exclusion chromatography. The results indicate that the polymer from transgenic plants appears to have a chemical structure identical to that of PHB produced by bacteria. However, the molecular weight distribution of the plant-produced PHB was much broader than that of typical bacterial PHB.