Tyrosine phosphorylation translocates beta-catenin from cell-->cell interface to the cytoplasm, but does not significantly enhance the LEF-1-dependent transactivating function

beta-catenin plays an essential role in cells, not only as a cadherin-associated complex, but also as a signaling molecule in the nucleus. Tyrosine phosphorylation of beta-catenin has been shown to correlate with tumorigenesis, cell migration, and developmental processes. However, its exact effects on downstream targets in the nucleus are not yet clear. In this study, we used HCT-15 colon carcinoma and NIH 3T3 fibroblasts as models to investigate the effects of a phosphotyrosine phosphatase (PTPase) inhibitor on the localization of beta-catenin, the binding affinity to LEF-1 (Lymphoid Enhancer Factor), and on LEF-1-dependent transactivation function. Treatment with a PTPase inhibitor, pervanadate, increased the tyrosine phosphorylation of beta-catenin in a time-dependent manner and led to its relocation from cell-cell interfaces to the cytoplasm. This phosphorylation/dephosphorylation of beta-catenin does not require its presence at cell-cell interfaces. However, tyrosine phosphorylation of beta-catenin does not change its binding affinity to LEF-1 nor enhance cyclin D1 transactivation, a nuclear target of beta-catenin/LEF-1. This result suggests that tyrosine phosphorylation of beta-catenin has effects on the binding to cadherins in the cytoplasm but not on its LEF-1-dependent transactivating function in the nucleus.

Studies on anthracenes. 1. Human telomerase inhibition and lipid peroxidation of 9-acyloxy 1,5-dichloroanthracene derivatives

The synthetically useful approaches to 9-acyloxy 1,5-dichloroanthracene derivatives are reported. The system selectively reduces the carbonyl group flanked by the peri substituents of the anthracenediones to give the corresponding 1,5-dichloro-9(10H)-anthracenone. Simple regioselective acylation of anthracenone is applied with appropriate acyl chlorides in CH2Cl2 with catalytic amount of pyridine to give the novel 9-acyloxy 1,5-dichloroanthracene derivatives. Considerable interest has developed in the mechanism of how anthracenone achieves this desirable selectivity. In an attempt to understand the mechanism of this reaction, solid-state structures of anthracene derivatives have been obtained. In addition, the inhibition of lipid peroxidation in model membranes was determined as was their ability to inhibit the telomere-addition function of the human telomerase enzyme together with their inhibition of the Taq polymerase enzyme. In contrast to (+)-alpha-tocopherol, 3b, 3c, 3d, 3g, and 3i do not enhance lipid peroxidation in model membranes. Implications for 9-acyloxy 1,5-dichloroanthracene analogues as potential anticancer agents are discussed.

Three cases of childhood nocturnal asthma due to buckwheat allergy

BACKGROUND

Buckwheat flour (BF) is known as a potent food allergen. Sensitization to it usually occurs by ingestion but also by inhalation in occupational or domestic exposure. Buckwheat chaff-stuffed pillows (BCP) can be contaminated with BF during the process of pilling, and many Korean children and adults use BCP for health reasons.

METHODS AND RESULTS

We here present three cases of BF allergy in children using BCP, who had been treated as nonatopic asthmatics after undergoing the routine allergy skin tests and serologic tests. We took careful clinical histories, and performed skin prick tests (SPT), the radioimmunoassay (RIA) for specific IgE, the BCP-elimination test, the BF bronchial provocation test, and IgE Western blot. All three children showed positive skin reactions to BF, but none of them had positive reactions to house-dust mites. Nocturnal asthmatic symptoms were improved during 7 days of BCP elimination, and asthmatic responses were observed by bronchial provocation tests with homemade BF extract. Serum BF-specific IgE antibodies and several IgE-binding proteins were detected by RIA and Western blot analysis, respectively.

CONCLUSIONS

Thus, a small amount of BF attached to BCP can induce BF sensitization, and BCP should be considered a main cause of childhood nocturnal asthma in those asthmatics exposed to these pillows.

Time- and depth-dependent changes in crosslinking and oxidation of shelf-aged polyethylene acetabular liners

Since crosslinking and oxidation of ultrahigh-molecular-weight polyethylene (UHMWPE) have important roles in determining the wear resistance of UHMWPE total joint components, the time and depth dependence of crosslinking and oxidation of new shelf-aged (2-11 years), ready-to-implant acetabular liners were studied by using solvent extraction and Fourier transform infrared spectroscopy. The ultrastructure of these materials also was examined by using low-voltage scanning electron microscopy in an oil-free vacuum. Oxidation levels increased with time and with depth (p < 0.0001) from the surface of the older liners to a maximum value at about 1-2 mm below the surface, then decreased. They were minimal at the midsection of the liners. The crosslinking of these liners decreased with time and depth (p < 0.0001) and was inversely proportional to the level of oxidation. High and depth-dependent oxidation levels were observed in all older liners made from GUR 415 and 412 resins but were distinctly absent from a comparably aged (i.e., 9 years) liner made from 1900 CM-resin. Some liners showed varying degrees of inhomogeneous and discontinuous morphologic ultrastructure in addition to varying amounts of porosity while others had a more homogeneous ultrastructure. Oxidation and crosslinking of polyethylene are time- and depth-dependent processes that are mutually competitive. We suggest that resin choice and perhaps consolidation-related variables lead to differences in polyethylene's ultrastructure. These ultrastructural differences in polyethylene's inhomogeneities, that is, the type (interconnected or closed-cell) or extent may affect the oxidation resistance of polyethylene. While oxygen diffusion to free radicals in polyethylene already is known to explain some of these time- and depth-dependent effects, perhaps such ultrastructural variations also may facilitate or retard oxygen diffusion in this material. Resin-based ultrastructural variability partially may explain the variability in the clinical performance of polyethylene total joint implant components. Thus resin choice or processing modifications related to polyethylene's ultrastructure may increase its oxidation resistance and ultimately improve the clinical wear performance of polyethylene total joint orthopedic implants.

Degradable and injectable poly(aldehyde guluronate) hydrogels for bone tissue engineering

Degradable and injectable hydrogels may be ideal for bone-tissue engineering, especially in the craniofacial region because of the ease of access for injection. Alginate hydrogels potentially could be used as injectable cell delivery vehicles, but they exhibit a limited range of mechanical properties and uncontrollable disintegration time. Therefore we synthesized new hydrogels, composed of poly(aldehyde guluronate) (PAG) and adipic acid dihydrazide, that have a wide range of mechanical stiffness and controllable degradation rate. MC3T3-E1 cells adhered and multiplied on PAG hydrogels in vitro. When primary rat calvarial osteoblasts were mixed with PAG hydrogels and subcutaneously injected into the backs of mice, mineralized bone tissues were formed 9 weeks following implantation. These hydrogels may find wide utility as an injectable delivery system for bone precursor cells as well as for other applications in tissue engineering.

Synchrotron X-ray study of lung surfactant-specific protein SP-B in lipid monolayers

This work reports the first x-ray scattering measurements to determine the effects of SP-B(1-25), the N-terminus peptide of lung surfactant-specific protein SP-B, on the structure of palmitic acid (PA) monolayers. In-plane diffraction shows that the peptide fluidizes a portion of the monolayer but does not affect the packing of the residual ordered phase. This implies that the peptide resides in the disordered phase, and that the ordered phase is essentially pure lipid, in agreement with fluorescence microscopy studies. X-ray reflectivity shows that the peptide is oriented in the lipid monolayer at an angle of approximately 56 degrees relative to the interface normal, with one end protruding past the hydrophilic region into the fluid subphase and the other end embedded in the hydrophobic region of the monolayer. The quantitative insights afforded by this study lead to a better understanding of the lipid/protein interactions found in lung surfactant systems.

Interaction of lung surfactant proteins with anionic phospholipids

Langmuir isotherms, fluorescence microscopy, and atomic force microscopy were used to study lung surfactant specific proteins SP-B and SP-C in monolayers of dipalmitoylphosphatidylglycerol (DPPG) and palmitoyloleoylphosphatidylglycerol (POPG), which are representative of the anionic lipids in native and replacement lung surfactants. Both SP-B and SP-C eliminate squeeze-out of POPG from mixed DPPG/POPG monolayers by inducing a two- to three-dimensional transformation of the fluid-phase fraction of the monolayer. SP-B induces a reversible folding transition at monolayer collapse, allowing all components of surfactant to remain at the interface during respreading. The folds remain attached to the monolayer, are identical in composition and morphology to the unfolded monolayer, and are reincorporated reversibly into the monolayer upon expansion. In the absence of SP-B or SP-C, the unsaturated lipids are irreversibly lost at high surface pressures. These morphological transitions are identical to those in other lipid mixtures and hence appear to be independent of the detailed lipid composition of the monolayer. Instead they depend on the more general phenomena of coexistence between a liquid-expanded and liquid-condensed phase. These three-dimensional monolayer transitions reconcile how lung surfactant can achieve both low surface tensions upon compression and rapid respreading upon expansion and may have important implications toward the optimal design of replacement surfactants. The overlap of function between SP-B and SP-C helps explain why replacement surfactants lacking in one or the other proteins often have beneficial effects.

Rescue treatment with abciximab in acute ischemic stroke

In acute ischemic stroke, reocclusion after an initially successful thrombolysis treatment can occur and is associated with increased morbidity and mortality. The authors present the successful use of abciximab, a platelet glycoprotein IIb/IIIa receptor inhibitor, in a patient with a thrombotic occlusion of the proximal middle cerebral artery, which was refractory to combined IV and intra-arterial thrombolysis and percutaneous intracranial balloon angioplasty.

p53, BCL-2, and Ki-67 expression according to tumor response after concurrent chemoradiotherapy for advanced rectal cancer

BACKGROUND

Concurrent chemoradiotherapy (CCRT) for locally advanced rectal cancer is an important modality for curative resection, but tumors show wide spectrum response. The purpose of this study was to investigate any correlation among related genetic mutations, proliferative index, and tumor response after CCRT.

METHODS

This study included 23 patients with rectal cancer, who were preoperatively staged as at least T3 N1 or T4 (determined by transrectal ultrasonography and MRI). Enrolled patients were given 5-FU 450 mg/m2/day and leucovorin 20 mg/m2/day intravenously for 5 days during weeks 1 and 5 of radiotherapy (45-54 Gy). Surgical resection was performed 4 weeks after completion of the scheduled treatment. Tumor response was classified as CR (complete response), PR (partial response: 50% diminution of tumor volume and downstaging), and NR (no response). Paraffin-embedded tissue obtained before chemoradiotherapy was studied by immunohistochemical staining for p53, BCL-2, and Ki-67. The extent of tumor response was correlated with proliferative activity and was measured by immunostaining Ki-67 proliferative antigen and the expression of p53 and BCL-2 oncoproteins.

RESULTS

All patients were resectable. CR was obtained in 4 patients, PR in 10 patients, and NR in 9 patients. The p53 mutation was noted in 16 patients: NR in 5 patients, PR in 9 patients, and CR in 2 patients (P = .638). BCL-2 expression was noted in 11 patients: NR in 4 patients, PR in 3 patients, and CR in 4 patients (P = .799). The Ki-67 labeling index was NR: 615.4+/-47.2; PR: 663.2+/-20.4; and CR: 765.5+/-58.3 (CR + PR vs. NR, P = .029).

CONCLUSIONS

Immunohistochemical expression of p53 and BCL-2 does not correlate with tumor response after CCRT, but Ki-67 labeling may be a useful parameter for radiosensitive tumors selected for CCRT.

A case of hemorrhagic gallbladder paraganglioma causing acute cholecystitis

Gallbladder paraganglioma is a very rare tumor and so far only a few cases have been reported. Most of these were asymptomatic and were found incidentally during operation. Recently, we experienced a gallbladder paraganglioma that gave rise to hemorrhage, which in turn caused acute cholecystitis. Our case involved a 45 year-old female patient complaining of an intermittent right upper abdominal pain. After a preoperative evaluation, cholecystectomy and lymphadenectomy were performed under the impression of gallbladder cancer with acute cholecystitis. Postoperative pathologic examination revealed a hemorrhagic gallbladder paraganglioma accompanied by acute cholecystitis. Immunohistochemical staining of the chief cells for neuron specific enolase, chromogranin and synaptophysin were positive. Sustentacular cells also stained positively for S100 protein.

Topography and instability of monolayers near domain boundaries

We theoretically study the topography of a biphasic surfactant monolayer in the vicinity of domain boundaries. The differing elastic properties of the two phases generally lead to a nonflat topography of "mesas," where domains of one phase are elevated with respect to the other phase. The mesas are steep but low, having heights of up to 10 nm. As the monolayer is laterally compressed, the mesas develop overhangs and eventually become unstable at a surface tension of about K(deltac(0))(2) (deltac(0) being the difference in spontaneous curvature and K a bending modulus). In addition, the boundary is found to undergo a topography-induced rippling instability upon compression, if its line tension is smaller than about Kdeltac(0). The effect of diffuse boundaries on these features and the topographic behavior near a critical point are also examined. We discuss the relevance of our findings to several experimental observations related to surfactant monolayers: (i) small topographic features recently found near domain boundaries; (ii) folding behavior observed in mixed phospholipid monolayers and model lung surfactants; (iii) roughening of domain boundaries seen under lateral compression; (iv) the absence of biphasic structures in tensionless surfactant films.

Impact of splenectomy for lymph node dissection on long-term surgical outcome in gastric cancer

BACKGROUND

In the treatment of gastric cancer, splenectomy is performed for effective lymph node dissection around the splenic artery and splenic hilum. The purpose of this study was to clarify the long-term outcome of splenectomy in the treatment of gastric cancer.

METHODS

The effect of splenectomy on recurrence and prognosis was examined in a retrospective analysis of 665 patients who had undergone curative total gastrectomy for gastric carcinoma from 1987 to 1996. The risk factors associated with recurrence and prognosis were investigated by univariate and multivariate analysis.

RESULTS

The splenectomy group showed more advanced lesions and a higher recurrence rate than the spleen-preserved group. However, after adjusting for the TNM (tumor, node, metastasis) stage, there was no significant difference in recurrence rate and pattern between the two groups. Logistic regression analysis revealed that gross type, serosal invasion, and nodal metastasis were independent risk factors for recurrence while splenectomy was not. When comparing patients with the same TNM (tumor, node, metastasis) stages, no significant difference in the 5-year survival rates was apparent. Multivariate analysis demonstrated that age, serosal invasion, and nodal metastasis were independent prognostic factors whereas splenectomy was not.

CONCLUSIONS

These data suggest that splenectomy for lymph node dissection in gastric cancer is not effective regarding long-term patient prognosis.

Clinical application of histamine prick test for food challenge in atopic dermatitis

Determining positive food challenges are not easy as there is an absence of simple and objective tests. Histamine, an essential mediator for allergic reactions, is involved in the pathogenesis of atopic dermatitis (AD) and food challenges can change histamine levels. The significances of a prick test with histamine (histamine prick test, HPT) relating to the interpretation of food challenges in AD were evaluated. A total of 467 AD patients participated in this study. Skin prick tests, identification of specific IgE and open food challenge were conducted for the identification of food allergy. Elimination diet was performed with HPT. HPTs were conducted before and after food challenges. The wheal sizes by HPT were significantly decreased after an elimination diet. The relative changes of wheal sizes significantly correlated with those of clinical severity scores in AD patients (p<0.001). The wheal sizes in HPT were increased with a positive provocation in open food challenges. In conclusion, HPT may be a simple and objective test to interprete the results of food challenges in patients with AD. The exact mechanisms of the changes in skin reactivity by HPT need further investigation.

Direct and precise determination of environmental radionuclides in solid materials using a modified Marinelli beaker and a HPGe detector

A simple but precise detection method was studied for the determination of natural radionuclides using a conventional HPGe detector. A new aluminium beaker instead of a plastic Marinelli beaker was constructed and examined to reach radioactive equilibrium conditions between radon and its daughter elements without the escape of gaseous radon. Using this beaker fifteen natural radionuclides from three natural decay series could be determined by direct gamma-ray measurement and sixteen radionuclides could be determined indirectly after radioactive equilibrium had been reached. Analytical results from ground water were compared with those from conventional alpha spectroscopy and the results agreed well within 12% difference. Nitrogen gas purge was used to replace the surrounding air of the detector to obtain a stable background and reducing the interference of radon daughter nuclides in the atmosphere. The use of nitrogen purging and the aluminium Marinelli beaker results in an approximately tenfold increase of sensitivity and a decrease of the detection limit of 226Ra to about 0.74 Bq kg(-1) in soil samples.

Expression of functional markers in acute nonlymphoblastic leukemia

Multidrug resistance parameters, tissue infiltration parameters, receptors for colony-stimulating factors (CSFr) and cell cycle parameters were analyzed using flow cytometry in 145, 109 initial and 36 relapsed or refractory, acute nonlymphoblastic leukemia (ANLL) patients to find out clinically more reliable functional parameters. Lung resistance-associated protein (LRP) was most frequently expressed in ANLL (44.1%) followed by P-glycoprotein (PGP) (35.9%) and multidrug resistance-associated protein (MRP) (8.3%). LRP and PGP were expressed more frequently in relapsed or refractory ANLL than initial ANLL cases. Complete remission rate after standard chemotherapy falls in PGP-positive cases (p = 0.001). CD44-positive ANLL cases relapsed more frequently. The organ tropism is different depending on the infiltration parameters, vascular cell adhesion molecule to splenomegaly, matrix metalloprotease-2 to hepatomegaly and to extramedullary infiltration other than spleen, liver or lymph node. The percentage of the granulocyte-macrophage-CSFr expression was high in M4 and M5, and granulocyte-CSFr-positive ANLL showed less extramedullary infiltration (p = 0.007) and more PGP expression. Ki-67 was expressed significantly less in refractory ANLL than initial ANLL and DNA topisomerase IIalpha was expressed significantly more in the surviving patients group. In conclusion, analysis of these new functional parameters could help to predict and overcome the clinical behavior of each ANLL at the time of diagnosis.

Coumarins isolated from Angelica gigas inhibit acetylcholinesterase: structure-activity relationships

Acetylcholinesterase (AChE) inhibitory activity-guided fractionation of Angelica gigas led to isolation and identification of a new coumarin, peucedanone (12), and isolation of 11 known coumarins. Among them, decursinol (1) represented the highest inhibitory activity toward AChE in vitro. The correlation of the inhibitory activities of the coumarins toward AChE with their chemical structures was studied.

Epstein-Barr virus infection, drug resistance and prognosis in Korean T- and NK-cell lymphomas

T-cell lymphomas are a biologically heterogeneous group of diseases with varying clinical presentations and outcomes. We tried to understand the effect of Epstein-Barr virus (EBV) on lymphogenesis, prognostic factors and drug resistance of T-cell lymphomas, and to establish their relationship with international prognostic factors. Formalin-fixed paraffin-embedded tissue sections from 35 patients (12 women and 23 men) with T-cell lymphomas were examined to detect the presence of EBV using RNA in situ hybridization for EBV-encoded small nuclear RNA (EBER) 1/2 and immunohistochemical stain for latent membrane protein (LMP)-1. We also tried to establish the expression of p53 and P-glycoprotein (P-gp) using immunohistochemistry. The distribution according to the subgroup was: two T-lymphoblastic lymphomas, 13 NK/T-cell lymphomas, one angioimmunoblastic T-cell lymphoma, 17 peripheral T-cell lymphomas, unspecified, and two anaplastic large cell lymphomas. The EBER was detected in 15 of 35 T-cell lymphomas (42.9%) and among these it was detected in five of 17 nodal lymphomas (29.4%) and 10 of 18 extranodal lymphomas (55.6%). There was close correlation between EBER positivity and NK/T-cell lymphoma (P = 0.032). Expression of LMP was found in a proportion of tumor cells in seven of the 15 EBER-positive cases (46.7%). There was no correlation between EBER expression and complete response (CR rate), but coexpression of EBER and p53 was associated with treatment failure (P = 0.047). The 18 patients (51.4%) with p53 expression had significantly poorer outcomes compared with the 17 patients without p53 expression (CR rate, P < 0.0005; overall survival, P = 0.0102). Twenty of 35 patients (57.1%) were positive for P-gp expression. P-gp expression was significantly associated with treatment failure (P = 0.001) and overall survival (P = 0.0089). Seventeen of 35 patients (48.6%) treated with systemic chemotherapy or radiation therapy achieved a CR after initial treatment. When the prognostic factors were grouped using the international prognostic index, the CR rate was 58.8% for the low risk group, 50.0% for the low-intermediate risk group, 14.3% for the high-intermediate risk group, and 0% for the high risk group. In conclusion, high incidence of EBV was detected among Korean patients with T-cell lymphomas. Our study supports the prediction that patients who express p53 and P-gp have a poorer prognosis than those who do not and this should be considered when treatment strategies for individual patients are selected.

MEK inhibits secretin release and pancreatic secretion: roles of secretin-releasing peptide and somatostatin

We investigated the mechanism of action of methionine enkephalin (MEK) on HCl-stimulated secretin release and pancreatic exocrine secretion. Anesthetized rats with pancreatobiliary cannulas and isolated upper small intestinal loops were perfused intraduodenally with 0.01 N HCl while bile and pancreatic juice were diverted. The effect of intravenous MEK on acid-stimulated secretin release and pancreatic exocrine secretion was then studied with or without coinfusion of naloxone, an anti-somatostatin (SS) serum, or normal rabbit serum. Duodenal acid perfusate, which contains secretin-releasing peptide (SRP) activity, was collected from donor rats with or without pretreatment with MEK, MEK + naloxone, or MEK + anti-SS serum, concentrated by ultrafiltration, and neutralized. The concentrated acid perfusate (CAP), which contains SRP bioactivity, was infused intraduodenally into recipient rats. MEK increased plasma SS concentration and inhibited secretin release and pancreatic fluid and bicarbonate secretion dose-dependently. The inhibition was partially reversed by naloxone and anti-SS serum but not by normal rabbit serum. In recipient rats, CAP increased plasma secretin level and pancreatic secretion. CAP SRP bioactivity decreased when it was collected from MEK-treated donor rats; this was partially reversed by coinfusion with naloxone or anti-SS serum. These results suggest that in the rat, MEK inhibition of acid-stimulated pancreatic secretion and secretin release involves suppression of SRP activity release. Thus the MEK inhibitory effect appears to be mediated in part by endogenous SS.

Colonic motility abnormality in patients with irritable bowel syndrome exhibiting abdominal pain and diarrhea

OBJECTIVES

Although colon dysmotility is recognized as a pathophysiological factor in irritable bowel syndrome (IBS), it has not been characterized. We have investigated motility patterns in IBS patients with abdominal pain and frequent defecation or diarrhea and in healthy volunteers.

METHODS

A recording catheter that had six polyvinyl tubes with infusion ports was placed in the transverse, descending, and sigmoid colon under fluoroscopy. After 2-h basal recordings, motility responses to cholecystokinin octapeptide (CCK-8) and a meal were studied for 3 h. The motility index (MI) and number of high amplitude propagating contractions (HAPCs) in 10 IBS patients were compared with those of 10 controls. HAPCs were correlated with abdominal pain, and colon transit time using radio-opaque markers was determined. Using human colon muscle strips, the effect of CCK-8 on muscle contractions was also studied.

RESULTS

The MI and mean number and peak amplitude of HAPCs in IBS patients were significantly greater than in controls. These abnormalities paralleled markedly shortened colonic transit time. Abdominal pain coincided with >90% of HAPCs. Dose-dependent muscle contraction by CCK-8 was profoundly suppressed both by loxiglumide and atropine.

CONCLUSIONS

The dysmotility in this subset of IBS patients was characterized by significantly increased occurrences of powerful HAPCs that paralleled rapid colon transit and were accompanied by abdominal pain. Thus, it is suggested that this powerful contraction is one of the causes of abdominal pain. The action of CCK-8 seems to be mediated via the colon enteric nervous system.

Thin layer chromatographic determination of organic acids for rapid identification of bifidobacteria at genus level

This study presents a simple and fast method for the identification of bifidobacteria using a thin layer chromatographic (TLC) analysis of the short chain fatty acids in a culture broth. When the chromatogram was sprayed with the indicator solution (methyl red-bromophenol blue in 70% ethanol), lactic acid exhibited two red spots, and acetic acid, propionic acid, and butyric acid all produced blue spots. Succinic acid and citric acid produced yellow and dark yellow spot, respectively. In addition, these organic acids showed different R(f) values. The total time taken to analyze the organic acids in the 10 bacterial culture broths using the proposed method was approximately 50 min. The proposed TLC method was used to analyze the organic acids in culture broths of the following strains, five Bifidobacterium species. (Bifidobacterium longum, B. breve, B. infantis, B. bifidum, and B. adolescentis) and five other lactic acid bacteria strains (Lactobacillus casei, L. bulgaricus, L. acidophilus, Streptococcus thermophilus, and S. lactis). Both spots of lactic acid and acetic acid were detected on all the TLC plates from the five bifidobacterial culture broths. The five other lactic acid bacterial culture broths, however, only exhibited lactic acid spots. Accordingly, the proposed TLC method would appear to be a useful tool for rapid identification of Bifidobacterium spp. at the genus level.

Effects of lung surfactant proteins, SP-B and SP-C, and palmitic acid on monolayer stability

Langmuir isotherms and fluorescence and atomic force microscopy images of synthetic model lung surfactants were used to determine the influence of palmitic acid and synthetic peptides based on the surfactant-specific proteins SP-B and SP-C on the morphology and function of surfactant monolayers. Lung surfactant-specific protein SP-C and peptides based on SP-C eliminate the loss to the subphase of unsaturated lipids necessary for good adsorption and respreading by inducing a transition between monolayers and multilayers within the fluid phase domains of the monolayer. The morphology and thickness of the multilayer phase depends on the lipid composition of the monolayer and the concentration of SP-C or SP-C peptide. Lung surfactant protein SP-B and peptides based on SP-B induce a reversible folding transition at monolayer collapse that allows all components of surfactant to be retained at the interface during respreading. Supplementing Survanta, a clinically used replacement lung surfactant, with a peptide based on the first 25 amino acids of SP-B also induces a similar folding transition at monolayer collapse. Palmitic acid makes the monolayer rigid at low surface tension and fluid at high surface tension and modifies SP-C function. Identifying the function of lung surfactant proteins and lipids is essential to the rational design of replacement surfactants for treatment of respiratory distress syndrome.

Inhibition of cytokine-induced vascular cell adhesion molecule-1 expression; possible mechanism for anti-atherogenic effect of Agastache rugosa

Adhesion molecules such as vascular cell adhesion molecule-1 (VCAM-1) play an important role during the early stages of atherogenesis. Agastache rugosa has an anti-atherogenic effect in low density lipoprotein receptor -/- mice. Moreover, A. rugosa reduced macrophage infiltration and VCAM-1 expression has been localized in aortic endothelium that overlies early foam cell lesions. This study ascertained that tilianin (100 microM), a major component of A. rugosa, inhibits the tumor necrotic factor-alpha (TNF-alpha)-induced expression of VCAM-1 by 74% in cultured human umbilical vein endothelial cells (HUVECs). Also, tilianin (100 microM) reduced TNF-alpha-induced activation of nuclear factor-kappaB in HUVECs.

IFNalpha sensitizes ME-180 human cervical cancer cells to TNFalpha-induced apoptosis by inhibiting cytoprotective NF-kappaB activation

Tumor necrosis factor alpha (TNFalpha) induces apoptosis of a variety of tumor cell types. The anti-tumor effect of TNFalpha is often augmented by interferon (IFN) gamma. We hypothesized that IFNalpha, which shares many biological activities with IFNgamma, might also synergize with TNFalpha for the induction of tumor cell death. We tested our hypothesis using ME-180 human cervical cancer cells exposed to either IFNalpha or TNFalpha alone or both. We analyzed the death of ME-180 cells by biochemical and cytological means, and investigated the molecular mechanism underlying cytotoxic synergism between the two cytokines. We found that (i) IFNalpha/TNFalpha synergistically induced apoptosis of ME-180 cells, which was accompanied by activation of caspases-3 and -8; (ii) IFNalpha induced signal transducer and activator of transcription (STAT) 1 phosphorylation, and transfection of phosphorylation-defective STAT1 dominant-negative mutant inhibited IFNalpha/TNFalpha-induced apoptosis; (iii) inhibition of nuclear factor kappaB (NF-kappaB) by proteasome inhibitor MG-132 sensitized ME-180 cells to TNFalpha alone; (iv) IFNalpha treatment attenuated TNFalpha-induced NF-kappaB reporter activity, while it did not inhibit DNA binding of NF-kappaB. Taken collectively, our results indicate that IFNalpha sensitizes ME-180 cells to TNFalpha-induced apoptosis by inhibiting TNFalpha-mediated cytoprotective NF-kappaB activation, and this sensitizing effect of IFNalpha is mediated through a STAT1-dependent pathway.

A clinicopathologic study on three cases of constrictive bronchiolitis

We describe the characteristic clinical and pathologic findings of three cases of constrictive bronchiolitis. All three patients were middle-aged women with chronic respiratory illness characterized by chronic cough, dyspnea, mild to severe obstructive pulmonary dysfunction, relatively normal chest radiographs with occasional peribronchial infiltration, and lack of response to bronchodilators or prednisolone. The patients also had medical diseases such as non-Hodgkin's lymphoma and hyperprolactinemia in case 1 and 3, respectively. None of the patients smoked cigarettes and had clinical evidence of recent viral lower respiratory tract infection. Histologic study by open lung biopsy revealed a spectrum of changes ranging from active cellular bronchiolitis to obliterative peribronchiolar fibrosis. The intervening interstitial and alveolar areas showed no remarkable lesion. Immunohistochemically, the bronchiolar or peribronchiolar inflammatory infiltrates mainly comprised of mixed T- and B-lymphocytes. It may be possible that the active form of constrictive bronchiolitis is initiated by attendant lymphocytic inflammation of the airways, which is followed by fibrous obliteration of bronchioles.

Ultrasound biomicroscopic diagnosis of cyclitic membranes

PURPOSE

To evaluate the utility of ultrasound biomicroscopy in imaging cyclitic membranes.

METHODS

Patients with hypotony and suspected or known cyclitic membrane underwent ultrasound biomicroscopic examination. Histopathology of cyclitic membrane was correlated with ultrasound biomicroscopy in three cases.

RESULTS

Six eyes of six patients were enrolled. Mean patient age was 62.2 +/- 18.4 (SD) years. The mean intraocular pressure in the affected eye was 4.3 +/- 3.4 mmHg. Three eyes were pseudophakic and three eyes were aphakic. All eyes had undergone two or more previous intraocular surgeries. Ultrasound biomicroscopy imaged the cyclitic membrane in all six eyes. Histopathology revealed fibroproliferative cyclitic membranes with associated inflammatory cells.

CONCLUSION

Ultrasound biomicroscopy is useful in detecting the presence of those cyclitic membranes that may not be identified on clinical examination.

The necessity of diet therapy for successful interferon-gamma therapy in atopic dermatitis

The avoidance of incriminated foods is one of the principal therapies for atopic dermatitis (AD). Recently, interferon (IFN)-gamma therapy has been tried in AD with limited success. The necessity of diet therapy for the success of IFN-gamma therapy in AD was evaluated. A total of 524 AD patients participated in this study and 316 patients among them were entered into open food challenge tests. As the first step, an elimination diet was administered to 43 AD patients and 30 AD patients were enrolled as an untreated control group. As the second step, 45 AD patients were treated by both IFN-gamma therapy and elimination diet alone, 30 AD patients by elimination diet alone, 50 AD patients by IFN-gamma therapy, and 43 AD patients as controls. Clinical severity reduced significantly by using only the elimination diet in 58.1% patients with varying degrees of AD. Elimination diet improved the clinical results of IFN-gamma therapy in AD. In regard to the food challenge test, 77.8% of AD patients showed an adverse reaction to at least one food. Diet therapy itself had therapeutic effects on AD and an elimination diet might be essential for the success of IFN-gamma therapy in AD.

Hematein inhibits tumor necrotic factor-alpha-induced vascular cell adhesion molecule-1 and NF-kappaB-dependent gene expression in human vascular endothelial cells

Monocyte adhesion to the endothelium via adhesion molecules is one of the earliest events in atherogenesis. It has been suggested that vascular cell adhesion molecule-1 (VCAM-1) plays a very important role in the recruitment of monocytes in atherosclerosis. The aim of our study was to evaluate whether hematein can influence the expression of VCAM-1 and the transcription of nuclear factor-kappaB (NF-kappaB)-dependent genes. Immunohistochemistry revealed that mouse aortic artery endothelial cells express VCAM-1 after feeding a high cholesterol diet for 8 weeks. Hematein dose dependently suppressed TNF-alpha-induced VCAM-1 in both surface (30.8%) and soluble protein (65%) production in HUVECs. The transcription level of VCAM-1 was measured by Northern blot analysis, and decreased VCAM-1 protein expression was associated with a reduction of VCAM-1 mRNA expression. Transient transfection study of NF-kappaB promoter construct and electrophoretic mobility shift assay suggested that hematein inhibited both NF-kappaB-dependent gene expression and NF-kappaB activation induced by TNF-alpha. Our results suggest that the down-regulation of VCAM-1 expression by hematein may in part be due to the inhibition of NF-kappaB-dependent gene expression.

Glucocorticoid-mediated repression of inflammatory cytokine production in fibroblast-like rheumatoid synoviocytes is independent of nuclear factor-kappaB activation induced by tumour necrosis factor alpha

OBJECTIVE

To determine whether steroids inhibit the production of inflammatory cytokines by the inhibition of nuclear factor kappaB (NF-kappaB) activation in fibroblast-like rheumatoid synoviocytes (FLSs) under inflammatory conditions, and to determine whether steroids stimulate the induction of synthesis of the inhibitory protein IkappaB-alpha in the anti-inflammatory immune response of these cells.

METHODS

Expression of the interleukin-6 (IL-6) and interleukin-1beta (IL-1beta) genes was measured by semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR), and the secreted IL-6 was measured with the enzyme-linked immunosorbent assay. Inhibition of the NF-kappaB activation was examined with the electrophoretic mobility shift assay (EMSA). In order to study dexamethasone (DEX)-dependent regulation of IkappaB-alpha expression, we performed Western blotting before and after stimulation with tumour necrosis factor alpha (TNF-alpha).

RESULTS

The inflammatory cytokine study showed that DEX suppressed gene expression and the production of protein in FLSs. EMSA demonstrated that identical amounts of NF-kappaB were present in the nucleus of the FLSs stimulated by TNF-alpha, with or without pretreatment with DEX. Treatment of FLSs with DEX did not induce an increase in IkappaB-alpha sufficient to prevent nuclear translocation of NF-kappaB on stimulation with TNF-alpha.

CONCLUSION

DEX may suppress the production of inflammatory cytokines, such as IL-6 and IL-1beta, but it neither prevents the translocation of NF-kappaB to the nucleus nor induces the synthesis of IkappaB-alpha protein in FLSs stimulated by TNF-alpha.

Alternative splicing of transcripts expressed by the Manduca sexta allatotropin (Mas-AT) gene is regulated in a tissue-specific manner

The Manduca allatotropin (Mas-AT) gene is expressed as at least three mRNA isoforms that differ from each other by alternative splicing. The location at which the alternative exons are included in the mature mRNAs occur within the open reading frame, so that three different propeptides are predicted as translation products. In the pharate adult insect, the major mRNA isoform expressed in the brain and frontal ganglion differs from that expressed in the nerve cord. Examination of the deduced translations of the alternative exons reveals the presence of three additional Mas-AT-like sequences that are flanked by basic amino acid residues. Therefore, the Mas-AT-like sequences present within the gene may be derived from a duplication of an ancestral Mas-AT-like sequence followed by divergence.

Increase in rat plasma antioxidant activity after E. coli lipopolysaccharide administration

It is well recognized that the sensitivity of animals to lipopolysaccharide (LPS) endotoxin varies tremendously. And, it has been recently observed that Sprague-Dawley rats dramatically increase the activity of hepatic endogenous antioxidative enzyme systems after LPS administration. This finding suggests that the relative resistance of rats to LPS may be related to a concomitant increase in the activities of the hepatic antioxidant systems. This study was designed to examine if the above reported hepatic change in rats given LPS could be observed at the systemic level. Male Sprague-Dawley or Wistar rats, weighing 250 - 350 g, were given increasing doses (10 - 100 mg/kg) of LPS i.p. under 1.0% isoflurane anesthesia. Antioxidant capacity (AOC), blood gas analysis, and the cardiovascular parameters of the arterial blood of animals were determined over a 4 hour period following LPS administration. In addition, we studied the effect of pretreatment with the non-specific nitric oxide synthase inhibitor, L-N(G)-Nitroarginine methyl ester hydrochloride (L-NAME), given 50 mg/kg s.c. one and 24 hours before the administration of 20 mg/kg LPS i.p. in Sprague-Dawley rats. Rats given sufficiently high doses of E. coli LPS to produce behavioral effects also showed increased plasma AOCs in the early period after the administration of LPS. Similar changes were noted in Sprague-Dawley and Wistar rat strains, but at different doses that reflect their differential sensitivities to the LPS induced inflammatory response. Also, the resistance of the Sprague-Dawley strain of rats to LPS was not altered by the prior administration of L-NAME, nor was the plasma AOC altered. In conclusion, our study suggests that the rat strains are relatively resistant to develop the toxic signs of LPS in the early period after the administration of LPS, especially in Sprague-Dawley rats. Moreover, endotoxin-induced increases in plasma AOC may contribute to the rats' resistance to LPS intoxication.

Successful interferon alpha therapy in atopic dermatitis of Besnier's prurigo pattern with normal serum IgE and blood eosinophil fraction: randomized case-controlled study

A randomized case-controlled study was carried out to investigate for interferon alpha therapy in atopic dermatitis (AD) of Besnier's prurigo pattern with normal serum IgE and normal blood eosinophil fraction. Interferon alpha therapy was conducted on 14 non-responders to interferon gamma and subsequent thymopentin therapy among 100 atopic dermatitis patients. Eight patients who improved significantly, showed skin lesions of the Besnier's prurigo pattern with normal serum IgE and normal blood eosinophil fraction. For the randomized prospective case-controlled study, 44 patients with the above characteristics were selected. Thirteen Besnier's prurigo patients were treated with interferon alpha therapy, ten with interferon gamma, ten with thymopentin, and the remaining 11 were untreated as the control group. With interferon alpha therapy, 11 out of 13 Besnier's prurigo patients with normal IgE and normal blood eosinophil fraction improved significantly, two out of ten improved with interferon gamma therapy, and none improved with thymopentin therapy or in the untreated control group. Interferon alpha therapy was effective on AD of Besnier's prurigo pattern with normal serum IgE and normal blood eosinophil fraction. These results suggest the possibility of non-IgE-mediated AD and the heterogeneity of atopic dermatitis.

Triptolide and chemotherapy cooperate in tumor cell apoptosis. A role for the p53 pathway

Triptolide (PG490), a diterpene triepoxide, is a potent immunosuppressive agent extracted from the Chinese herb Tripterygium wilfordii. We have previously shown that triptolide blocks NF-kappaB activation and sensitizes tumor necrosis factor (TNF-alpha)-resistant tumor cell lines to TNF-alpha-induced apoptosis. We show here that triptolide enhances chemotherapy-induced apoptosis. In triptolide-treated cells, the expression of p53 increased but the transcriptional function of p53 was inhibited, and we observed a down-regulation of p21(waf1/cip1), a p53-responsive gene. The increase in levels of the p53 protein was mediated by enhanced translation of the p53 protein. Additionally, triptolide induced accumulation of cells in S phase and blocked doxorubicin-mediated accumulation of cells in G(2)/M and doxorubicin-mediated induction of p21. Our data suggest that triptolide, by blocking p21-mediated growth arrest, enhances apoptosis in tumor cells.

Varying expression levels of colony stimulating factor receptors in disease states and different leukocytes

Administration of G-CSF may not always respond in rise of neutrophil counts in different patient population. In order to understand a possible inter-relationship between the G-CSF and GM-CSF induced leukocyte responses and expression levels of receptors for G-CSF (G-CSFr) and GM-CSF (GM-CSFr), the levels of each receptor and CSF were measured in patients with basophilia (8), eosinophilia (14) and bacterial infection showing neutrophilia (12) in comparison with normal healthy adults (12) and children (14). G-CSFr was expressed in neutrophils in the largest amount followed by monocytes, but GM-CSFr was expressed more in monocytes than neutrophils. Lymphocytes and basophils did not express G-CSFr or GM-CSFr. The amount of GM-CSFr in neutrophils was present less in patients with infection than normal control (P = 0.031). The neutrophils expressed more G-CSFr than GM-CSFr. The quantity of G-CSFr in eosinophil showed marked interval change, higher in acute stage. The plasma concentrations of G-CSF in patients with infection were much higher than normal adults or children (117.95 +/- 181.16 pg/ml, P < 0.05). Binding assay with excess amount of CSFs could discriminate the patient who did not show any response to G-CSF or GM-CSF administration. After incubation with excess CSFs, more receptors were blocked in children than in adults (G-CSF P = 0.024, GM-CSF P = 0.006). These results indicate that the amount of CSFr in leukocyte varies in different types of leukocyte, and changes according to the patients' condition even in the same type of leukocyte, and the CSFrs of children bind to CSFs more than those of adults.

Controlled growth factor release from synthetic extracellular matrices

Polymeric matrices can be used to grow new tissues and organs, and the delivery of growth factors from these matrices is one method to regenerate tissues. A problem with engineering tissues that exist in a mechanically dynamic environment, such as bone, muscle and blood vessels, is that most drug delivery systems have been designed to operate under static conditions. We thought that polymeric matrices, which release growth factors in response to mechanical signals, might provide a new approach to guide tissue formation in mechanically stressed environments. Critical design features for this type of system include the ability to undergo repeated deformation, and a reversible binding of the protein growth factors to polymeric matrices to allow for responses to repeated stimuli. Here we report a model delivery system that can respond to mechanical signalling and upregulate the release of a growth factor to promote blood vessel formation. This approach may find a number of applications, including regeneration and engineering of new tissues and more general drug-delivery applications.

Facile and efficient total synthesis of (+)-preussin

[structure] The enantioselective total synthesis of (+)-preussin, a potent antifungal agent, has been achieved. The key steps are a Pd(0)-catalyzed oxazoline-forming reaction from L-phenylalanine, hydrogenolysis, and subsequent diastereoselective reductive cyclization of the intermediate aminoketone to pyrrolidine using Pearlman's catalyst.

Identification and characterization of the major allergens of buckwheat

BACKGROUND

Buckwheat (BW) has been recognized as a common food allergen in Korea, Japan, and other countries. Until now, serologic findings of BW food-allergic patients and its major allergenic components have not been clarified. In this study, we analyzed the serologic findings of BW food allergy and characterized its major allergenic components.

METHODS

Nineteen BW-allergic subjects with symptoms after BW ingestion and 15 asymptomatic control subjects with positive skin prick test to BW were recruited. BW-specific IgE was measured with the Pharmacia CAP kit. Allergenic components of BW were analyzed by IgE immunoblotting, periodate oxidation, two-dimensonal PAGE, and sequencing of N-terminal amino acids.

RESULTS

From the BW-allergic patients and asymptomatic controls, the sensitivity (100%), specificity (53%), and negative (100%) and positive predictive values (73%) of Pharmacia CAP specific IgE for diagnosis were estimated. The prevalence of IgE binding to 24-kDa (pI 8.3), 16-kDa (pI 5.6), and 9-kDa (pI 5.0/ 6.0) allergens was higher than 50% in BW-allergic and asymptomatic subjects. However, the specific IgE to split 19-kDa (pI 6.5/7.0) allergens were more specifically found in BW-allergic patients than in asymptomatic subjects (78% vs 7%). N-terminal amino-acid sequences of 19-kDa and 16-kDa allergens showed moderate and weak homology to the 19-kDa globulin protein of rice and alpha-amylase/trypsin inhibitor of millet, respectively. The N-terminus of the 9-kDa isoallergens were not different from each other and were identified as the reported trypsin inhibitors of BW. Attenuation of the IgE binding to the 9-kDa allergen was found with periodate oxidation.

CONCLUSIONS

The allergens of 24, 19, 16, and 9 kDa are strong candidates to be major allergens, and the 19-kDa allergen was relatively specific for BW-allergic patients. Moreover, measurement of BW-specific IgE and the features of immunoblotting should be very useful tools in the diagnosis of BW allergy.

Prevalence of gynecologic cancers among female Vietnam veterans

The possibility of a gender-specific health problem associated with the Vietnam War has been a concern since the war. We targeted 4140 female Vietnam veterans and 4140 veteran controls to complete a structured telephone interview that included questions regarding any history of gynecologic cancer. As a measure of association between the risk of cancer and military service in Vietnam, odds ratios and 95% confidence intervals were calculated using multiple logistic regression models that yielded estimates of potential cofounders. Although 8% of Vietnam veterans and 7.1% of non-Vietnam veterans reported a history of gynecologic cancers, namely, breast, ovary, uterus, or cervix, the difference was not statistically significant either for the individual site or for the gynecologic cancers as a group. Female Vietnam veterans have not experienced a higher prevalence of gynecologic cancer in the 30 years since the conflict.

Effects of prednisolone on eosinophils, IL-5, eosinophil cationic protein, EG2+ eosinophils, and nitric oxide metabolites in the sputum of patients with exacerbated asthma

Corticosteroids are considered to be one of the most effective medicine for asthma by suppressing airway inflammation. This study was carried out to investigate the effects of prednisolone in the sputum of exacerbated asthmatics. Clinical severity, cell differentials, levels of interleukin (IL)-5, eosinophil cationic protein (ECP), EG2+ eosinophils, and nitric oxide (NO) metabolites were measured. Sputum was examined 2 weeks apart in 13 exacerbated asthmatics before and after prednisolone treatment, and once in 12 stable asthmatics. We used a sandwich ELISA for IL-5, fluoroimmunoassay for ECP, immunohistochemical staining for EG2+ eosinophils, a NO metabolites assay using modified Griess reaction. Exacerbated asthmatics, in comparison with stable asthmatics, had significantly higher proportion of eosinophils, higher level of ECP, higher percentage of EG2+ eosinophils, and NO metabolites. Exacerbated asthmatics after treatment with prednisolone had reduced the proportions of eosinophils, reduced level of IL-5, ECP and percentage of EG2+ eosinophils. FEV1 was correlated with the proportion of eosinophils, ECP, and IL-5 respectively. These findings suggest that prednisolone is considered to be effective medicine for asthma by suppressing eosinophil activation through IL-5.

Pregnancy outcomes among U.S. women Vietnam veterans

BACKGROUND

Since the 1965-1975 Vietnam War, there has been persistent concern that women who served in the U.S. military in Vietnam may have experienced adverse pregnancy outcomes.

METHODS

We compared self-reported pregnancy outcomes for 4,140 women Vietnam veterans with those of 4,140 contemporary women veterans who were not deployed to Vietnam. As a measure of association, we calculated odds ratios (OR) and 95% confidence intervals (CI) using logistic regression adjusting for age at conception, race, education, military nursing status, smoking, drinking and other exposures during pregnancy.

RESULTS

There was no statistically significant association between military service in Vietnam and index pregnancies resulting in miscarriage or stillbirth, low birth weight, pre-term delivery, or infant death. The risk of having children with "moderate-to-severe" birth defects was significantly elevated among Vietnam veterans (adjusted OR = 1.46, 95% CI = 1.06-2.02).

CONCLUSIONS

The risk of birth defects among index children was significantly associated with mother's military service in Vietnam.

Purification of dual-tagged intact recombinant proteins

Large-scale purification of recombinant proteins has been used extensively to assist numerous protein studies, including investigation of function, substrate identification and protein-protein interaction of low abundance proteins. Genetic fusion of affinity tags to these proteins has also been widely used for ease of purification by affinity chromatography. However, this technique sometimes yields unstable and degraded protein products limiting its application. In this study, we show a facile and straightforward method of dual-tagged recombinant protein purification that eliminates contamination by degraded protein products. A 6His-containing BamHI-HindIII fragment from pQE12 was ligated into the pGEX-KG BamHI-HindIII fragment and the protein of interest (p25(nck5a), which is highly susceptible to proteolytic degradation when expressed and purified from bacteria) was cloned into the BamHI site without a termination codon. The resulting plasmid construct, designated as pGST-p25(nck5a)-6His, with GST at the N-terminal and 6His at the C-terminal was expressed in Escherichia coli DH5alpha and purified using a two-step procedure. We show that using Ni(2+)-NTA chromatography as a first purification step and GSH-agarose chromatography as a second step, rather than vice-versa, yields a highly purified intact protein that is free of any contaminating degraded protein product. The purified fusion protein is soluble and fully active.

The expression of cytokeratin 18 in transitional cell carcinoma comparing with hepatoma

The epithelium in kidneys and urinary bladders contain CK18 as in liver cells. The modulation of cytokeratin 18 during tumor transformation in hepatoma had been previously recognized through a series of biochemical and immunological approaches. A 14 KD hepatoma related molecules was found in the previous studies. We would like to utilize the hepatoma transformation model to study the changes in CK18 in transitional cell carcinoma, using immunoblotting and western blotting techniques. The result is that transitional cell carcinoma retain their CK18 molecule. Furthermore, CK18 related molecules similar to those seen in hepatoma also present in transitional cell carcinoma. The conclusions are transitional cell carcinoma contains CK18 related proteins similar to those seen in hepatoma tissues. We suggest that this element would be responsible for the change during the malignant transformation processes.

Stabilizing of cytokeratin in PLC/PRF/5 cells

There are two sorted groups of cytokeratin 18 (CK18) in forms of assembly and disassembly in PLC/PRF/5 cells. A subcellular shifting is found in association with conditions of microtubule networks. The finding shows that CK18 mostly in forms of assembly, when microtubule networks are in status. The result also reveals that CK18 is relatively in forms of disassembly, while microtubule networks are disrupted in steps. It indicates that intact microtubule networks are probably a stabilizing factor of assembled CK18. It implies that CK18 is not a stable molecule when the cell is under environmental stress.

Sustained and controlled release of daunomycin from cross-linked poly(aldehyde guluronate) hydrogels

We have incorporated daunomycin, an antineoplastic agent, into a biodegradable hydrogel through a labile covalent bond. In brief, sodium alginate was chemically broken down to low molecular weight and followed by oxidation to prepare poly(aldehyde guluronate). Adipic dihydrazide was used to incorporate the drug into the polymer backbone and cross-link the polymer to form hydrogels. Daunomycin can be released from the hydrogel after the hydrolysis of the covalent linkage between the drug and the polymer. A wide range of release profiles of daunomycin (e.g., from 2 days to 6 weeks) has been achieved using these materials, and the biological activity of the released daunomycin was maintained.

Solubility changes in shelf-aged ultra-high molecular weight polyethylene acetabular liners

Crosslinking of extruded, air-packaged, irradiated, shelf-aged (10 consecutive years) polyethylene acetabular liners was measured versus time and material location by using a hot xylene extraction protocol. Insolubility (crosslinking) of new polyethylene liners was 87%, but decreased to 45% after 10 years of shelf-aging. This degradation is similar to that observed from retrieved (aged in vivo) acetabular cups. Crosslinking varied with depth in the aged liners and with radial location in the unaged liners. Given that crosslinking improves polyethylene's wear resistance, crosslinking degradation of polyethylene orthopaedic components must be controlled to improve the long-term clinical performance of total joint implants.