Relaxation dynamics of liposomes in an aqueous solution.

The gel-liquid crystal phase transition has been studied by the temperature and frequency dependent dielectric relaxation behavior of liposomes in an aqueous solution (40 g L(-1) DPPC-water mixture). Four relaxation processes were observed in the frequency range from 40 Hz to 30 GHz which were ascribed to different molecular mechanisms, related to the structural units of the system. The gel-liquid crystal phase transition was also described very accurately from the temperature-dependent dielectric relaxation strength, relaxation time and symmetric shape parameter of the relaxation functions obtained from the fitting procedure. Relaxation process 3, obtained from the dielectric fitting procedure, was confirmed by dielectric modulus analysis. A comparison of the lipid membrane with non-biological systems like liquid crystals was performed. It was determined that the lipid membrane has a ferroelectric liquid crystal like behavior. Process 3 is comparable to the soft mode relaxation process observed in ferroelectric liquid crystals which was detected close to the smectic-C*-smectic-A phase transition. Differential scanning calorimetry was also used to confirm the gel-liquid crystal phase transition of this mixture.

Does planned intravenous sedation affect preoperative anxiety in patients?

Dental surgery generally causes stress and fear, which may affect patient physiology and increase perioperative anxiety. Dental anxiety is considered to be an important factor in determining the need for intravenous sedation. One of the gold standards for measuring preoperative anxiety is Spielberger's State-Trait Anxiety Inventory (STAI). The authors have previously assessed preoperative anxiety using STAI and recommended that intravenous sedation be performed for patients whose anxiety level is high. The intravenous cannulation necessary for sedation and sedation itself may increase anxiety. The authors carried out this study to examine whether planning intravenous sedation before surgery increases preoperative anxiety. The subjects were patients who planned to undergo wisdom teeth extraction under local anaesthesia in the authors' hospital. They were divided into two groups on the basis of the planned intravenous sedation. STAI scores were compared between the initial visit and just before surgery. There were no significant differences in the state and trait anxiety scores between the initial visit and the day of the surgery in the two groups. Planned intravenous sedation based on the evaluation of anxiety levels using STAI is effective for promoting a safe operation without aggravating preoperative anxiety.

Hydrophilic polymer supports for solid-phase synthesis: preparation of poly(ethylene glycol) methacrylate polymer beads using "classical" suspension polymerization in aqueous medium and their application in the solid-phase synthesis of hydantoins.

Lightly cross-linked hydrophilic polymer beads representing new types of supports for solid-phase synthesis have been prepared from commercial oligoethylene glycol monomethacrylates using an aqueous suspension polymerization process and specifically designed polymerization mixtures. These beads swell extensively in solvents with a wide range of polarities from dichloromethane, tetrahydrofuran, and water to dimethylformamide, and they enable high functional loadings of 1.2-1.8 mmol g(-1). Their ability to serve as supports was demonstrated in the model solid-phase synthesis of a small library of hydantoins. This four-step synthesis using primary amines readily affords yields of over 70%.

[Percutaneous radiofrequency ablation (PRFA) for hepatocellular carcinoma].

Percutaneous local treatment for hepatocellular carcinoma is minimally invasive. Moreover, since local radical cure may be possible, the procedure has become widely performed. Percutaneous radiofrequency ablation (PRFA) was recently introduced in Japan. Excellent results are expected. PRFA was conducted on 244 tumor nodules found in 177 cases of hepatocellular carcinoma (a total of 349 procedures), and the usefulness was examined. 1. Tumor markers significantly decreased after PRFA and a favorable necrotic effect was obtained on CT images. 2. Mild post-operative inflammatory reaction and exacerbation of liver dysfunction was noted, but recovery was achieved in one week. There were no major complications. 3. The cumulative local recurrence in 1 year was 5.4%, which is lower than that with percutaneous microwave coagulation therapy. 4. PRFA is a safe and handy procedure for hepatocellular carcinoma, which promises the favorable effect of coagulation necrosis. PRFA will likely become a key method among local ablation therapies.

Disruption of the p16/cyclin D1/retinoblastoma protein pathway in the majority of human hepatocellular carcinomas.

p16, cyclin D1 and retinoblastoma protein (pRB) regulate G1 to S transition and are commonly targeted in various cancers. However, few studies have simultaneously examined all components of the p16/cyclin D1/pRB pathway (RB pathway) in hepatocellular carcinoma (HCC). To clarify the role of the disruption of the RB pathway in HCC, we analyzed p16, pRB and cyclin D1 in 47 HCCs. Inactivation of p16 was detected in 30 of 47 HCCs (64%) by Western blot analysis and significantly correlated with hypermethylation of the promoter of this gene. pRB expression was found to be absent in 13 of 47 HCCs (28%) by immunohistochemistry. We found that 38 of 47 HCCs (81%) contained at least one inactivation in either pRB or p16. Furthermore, there was a significant inverse correlation between p16 and pRB inactivation (p = 0.041). Overexpression of cyclin D1 was detected in 5 of 47 HCCs (11%) by immunohistochemistry. The cases with cyclin D1 overexpression exhibited an advanced clinicopathological appearance and also contained inactivation of pRB and/or p16. These findings suggest that inactivation of pRB and/or p16 is a major event in human hepatocarcinogenesis, while cyclin D1 overexpression may confer additional growth advantages to the tumor in addition to pRB and/or p16 inactivation in HCC.

Incidence and characteristics of thyroid dysfunction following interferon therapy in patients with chronic hepatitis C.

Thyroid functions were analyzed before, during and after interferon (IFN) therapy in patients with chronic hepatitis C. According to the results of routine thyroid function tests and measurements of the levels of anti-thyroid autoantibody prior to the therapy, patients were divided into 2 groups; Group A (19 patients) had at least one abnormal finding related to the thyroid, and Group B (40 patients) did not show any abnormality. Five patients (26%) in Group A and 4 (10%) in Group B showed thyroid dysfunctions which were very clearly reflected by thyrotropin (TSH) measurements. Interestingly, the time of peak TSH elevation in Group A (mean +/- SD, 4.3 +/- 0.8 months) was significantly earlier than that in Group B (6.8 +/- 0.8). Most patients in Group B were diagnosed as having destructive thyroiditis. These findings may suggest that the pathogenesis of IFN-induced thyroid dysfunction consists not only of exacerbation of pre-existing thyroid autoimmunity but also of de novo destructive changes even in the intact thyroid before IFN therapy.

Infrequent alterations of the p16INK4A gene in liver cancer.

We examined the genomic status of the p16INK4A (inhibitor of cyclin-dependent kinase 4 A) and cyclin-dependent kinase 4 (CDK4) genes in 62 human hepatocellular carcinomas (HCCs), 5 cholangiocellular carcinomas and 6 cell lines derived from human liver cancers. Although no samples showed the homozygous deletion of the p16INK4A gene, we detected intragenic mutations of the p16INK4A gene in 3 HCCs and one HCC cell line, which led to an amino-acid substitution or a frameshift. In 2 HCC samples with mis-sense mutations of the p16INK4A gene, loss of heterozygosity on 9p22 was also detected, suggesting that the loss of function of p16 was induced during hepatocarcinogenesis. On the other hand, amplification or rearrangement of the CDK4 gene was not detected in any samples examined in this study. These results indicated that the mutations or deletions of the p16INK4A gene are not frequent, but may play a role in a sub-set of human HCC.

Sensitive detection of circulating hepatocellular carcinoma cells in peripheral venous blood.

BACKGROUND: This study was performed to develop a sensitive method for the detection of circulating hepatocellular carcinoma (HCC) cells in peripheral blood, in advance of the diagnosis of distant metastasis of HCC by conventional means. METHODS: Peripheral blood (5 ml) samples were obtained from 64 patients with HCC and from 48 control subjects (31 patients with benign liver disease, 8 with metastatic liver cancer, and 9 with normal liver function). To identify HCC cells in peripheral blood, liver-specific human alpha-fetoprotein (hAFP) mRNA was amplified from total RNA extracted from whole blood by reverse transcriptase-polymerase chain reaction. RESULTS: Human alpha-fetoprotein mRNA was detected in 23 blood samples from the HCC patients (23/64, 36%), in 17 patients in whom there was no clinical evidence of distant metastasis. In contrast, there were no control patients whose samples showed detectable hAFP mRNA in the peripheral blood. The presence of hAFP mRNA in blood seemed to be correlated with the stage (by TNM classification) of HCC, the serum hAFP value, and the presence of intrahepatic metastasis, portal vein thrombosis, and/or distant metastasis. CONCLUSIONS: Reverse-transcriptase polymerase chain reaction is a very sensitive method for detecting circulating HCC cells. With this technique, important information for the management of HCC can be acquired, such as the indications for orthotopic liver transplantation in HCC patients. Moreover, use of this detection method may encourage investigation of the mechanism of metastasis in HCC.

Amplification and overexpression of the cyclin D1 gene in aggressive human hepatocellular carcinoma.

We analyzed the genetic alterations of the cyclin D1 and INT-2 genes in hepatocellular carcinomas (HCCs) from 45 patients. Among these, expression of the cyclin D1 mRNA was also analyzed in 18 of them by Northern blotting. The cyclin D1 gene was amplified 3-16 fold in five HCCs (11%); among these, the INT-2 gene was also amplified 2-10 fold in four HCCs. We analyzed the mRNA of cyclin D1 in four HCCs with gene amplifications, and 6-10 fold overexpressions were detected in all of them. Because the cyclin D1 gene was amplified in patients at an advanced stage of HCC with rapid tumor growth, it appeared to be associated with the aggressive behavior of tumors. Studies on loss of heterozygosity on chromosome 13q, where the retinoblastoma (RB) gene is located, indicated that all HCCs with an amplified cyclin D1 gene retained heterozygosity on chromosome 13q. These results suggest that amplification and overexpression of the cyclin D1 gene result in the rapid growth of a subset of HCC, even though the function of the RB gene is retained.

GM-CSF and eosinophil chemotactic factors in an acute lymphoblastic leukemia patient with eosinophilia.

We describe a patient with common acute lymphoblastic leukemia associated with blood and cerebrospinal fluid (CSF) eosinophilia. Serum obtained at onset and conditioned medium prepared from T cells obtained at remission stimulated with interleukin-2 contained eosinophil colony stimulating activity (Eo-CSA), which was confirmed to be predominantly GM-CSF. Leukemic cell conditioned medium and serum obtained at remission contained no Eo-CSA. The CSF contained increased eosinophil chemotactic activity, however, this factor was not identified.