Syntheses of heterotriptycenes and their Pt complexes that emit circularly polarised fluorescence and phosphorescence

Herein, we report the synthesis and chiroptical properties of 2-azatriptycenes and their platinum(II) complexes, which represent the first examples of heterotriptycenes and metallotriptycenes that exhibit circularly polarized fluorescence and phosphorescence (CPF and CPP). Theoretical studies for CPF and CPP strongly support the experimental findings.

Surface hydrophobicity of particles is not necessarily the most important determinant in their in vivo disposition after intravenous administration in rats

The in vivo disposition of polystyrene microsphere (MS) with the particle size of 50 nm (MS-50) and lecithin-coated MS-50 (LMS-50) after intravenous administration to rats was characterized. While a rapid elimination from the systemic circulation was observed for MS-50, much more prolonged circulating property was observed for LMS-50. In addition, this in vivo disposition property of LMS-50 was suggested to be ascribed to its lower affinity to the liver, which is the determining organ of the in vivo disposition of MS-50. The evaluation of surface hydrophobicity of MS-50 and LMS-50 in buffer solution revealed that the surface of MS-50 is more hydrophobic than that of LMS-50. However, LMS-50 was oppositely found to be more hydrophobic than that of MS-50 in rat serum. The profiles of serum proteins associated with MS-50 and LMS-50 were also examined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The results showed that the amounts of some adsorbed proteins are greatly different between MS-50 and LMS-50. From these findings, it was suggested that the substantial difference in the in vivo disposition between MS-50 and LMS-50 would not be attributed to the difference in their surface hydrophobicity in the blood, but the difference in the type of serum proteins associated with them.

sFlt-1 gene-transfected fibroblasts: a wound-specific gene therapy inhibits local cancer recurrence

Local recurrence occurs frequently at the site of injury after surgical resection. On the other hand, fibroblasts have been shown to accumulate in the injured area to heal and remodel the damaged tissues. Therefore, fibroblasts are likely to be useful as wound-specific vectors for delivery of genes to sites of surgically injury. The present study was performed to investigate wound-specific migration of exogenously administered fibroblasts and efficacy of gene therapy using genetically engineered fibroblasts in an i.p. wound recurrence model in rats. We demonstrated that fibroblasts transfected with the GFP gene accumulated specifically around the site of injury immediately after i.p. injection. Then, fibroblasts transfected with an adenovirus designated as AdFex that encoded the soluble form of Flt-1 (sFlt-1), a vascular endothelial growth factor receptor, were administered i.p. to the rats to examine inhibition of tumor growth. At day 16 after implantation, a significantly smaller tumor volume and less microvessel density in wound sites were observed in the AdFex/fibroblast-treated rats than in controls. Furthermore, this treatment also resulted in an improved survival rate. In conclusion, autologous fibroblasts show promise as a wound-specific vector for gene therapy, and administration of sFlt-1 gene-engineered fibroblasts contributed to local control of the tumor around the injured tissue.

Inhibitory effect of Y-27632, a ROCK inhibitor, on progression of rat liver fibrosis in association with inactivation of hepatic stellate cells

BACKGROUND/AIMS

Activation of hepatic stellate cells (HSCs) is a final common pathway of liver fibrosis. Recently, it has been demonstrated that the small GTPase Rho is involved in HSCs activation, and that Y-27632, an inhibitor of Rho-kinase which is an effector that acts downstream of Rho, inhibits Rho-associated effects. The objective of the current study was to investigate the inhibitory effects of Y-27632 on the activation of HSCs and the progression of liver fibrosis.

METHODS

Y-27632 (1, 10, 100 microM) was added to HSCs isolated from normal rat liver.

RESULTS

HSCs maintained the 'star-like' configuration of the quiescent stage in the presence of Y-27632, as well as inhibition of the expression of Na+/Ca2+ exchanger mRNA which was reported to be an indicator of HSCs activation. In addition, when Y-27632 (30 mg/kg body weight) was administered to rats with carbon tetrachloride-induced liver fibrosis, collagen deposition was inhibited, the hepatic hydroxyproline content was decreased, and the serum hyaluronic acid level was reduced. Moreover, Y-27632 reduced the number of smooth muscle alpha-actin-positive cells and transforming growth factor-beta1-positive cells, and inhibited the expression of Na/Ca2+ exchanger mRNA.

CONCLUSIONS

These findings indicate that Y-27632 may be useful for the clinical management of liver fibrosis.

Biliary excretion of polystyrene microspheres depends on the type of receptor-mediated uptake in rat liver

Hepatic uptake and biliary excretion of fluorescein isothiocyanate-labeled polystyrene microspheres with a particle size of 50 nm (MS-50) were studied in rats. Liver perfusion studies revealed that not only apo-E-mediated but also asialoglycoprotein receptor-mediated uptake is involved in the mechanism of the serum protein-dependent uptake of MS-50 in the liver. The uptake of MS-50 mediated by apo-E contributes more to the total uptake of MS-50 by the hepatocytes than that via asialoglycoprotein receptor in the presence of serum in the perfusate. Furthermore, it was found that MS-50 is substantially excreted into the bile by transcytosis. The extent of exocytosis of MS-50 taken up by the hepatocytes was much higher after MS-50 was endocytosed via asialoglycoprotein receptor than after taken up via the process mediated by apo-E. On the basis of these results, a possible regulation of the intracellular sorting of ligands, depending on the receptor-mediated uptake mechanism, was inferred.

RECK gene expression in hepatocellular carcinoma: correlation with invasion-related clinicopathological factors and its clinical significance. Reverse-inducing--cysteine-rich protein with Kazal motifs

The RECK (reversion-inducing-cysteine-rich protein with Kazal motifs) gene was initially isolated as a transformation suppressor gene. It encodes a membrane-anchored glycoprotein with multiple serine protease inhibitor-like domains. The RECK gene is expressed widely in normal organs but is undetectable in many tumor-derived cell lines. When artificially expressed in such cell lines, RECK suppresses their invasive and metastatic activities. Clinical implications of these findings, however, remained undefined because of the lack of studies using fresh human tumor samples. In the present study, we have addressed this issue by analyzing the levels of RECK gene expression in hepatocellular carcinoma (HCC). RECK mRNA was detectable by RNA blot hybridization in all the tumorous and contiguous nontumorous tissues obtained from 64 patients with HCC. In 26 cases, the RECK expression in tumorous tissues was higher than that in nontumorous tissues. The expression of RECK protein in these tissues could also be demonstrated by immunohistochemistry. Patients with high RECK mRNA expression in tumorous tissues tended to show better survival (P =.02), and such tumors had a tendency to be less invasive. Univariate and multivariate analysis revealed that the RECK mRNA expression is a novel and independent variable affecting overall survival (P =.01). These findings support the hypothesis that RECK has negative effects on the invasiveness of HCC cells and suggest the feasibility of RECK mRNA as a promising prognostic molecular marker for HCC.

Spleen-derived dendritic cells engineered to enhance interleukin-12 production elicit therapeutic antitumor immune responses

The major goal in cancer immunotherapy is the induction of tumor-specific T lymphocytes capable of killing tumor cells. As both dendritic cells (DCs) and interleukin-12 (IL-12) can play immunostimulatory roles in vivo, the use of a combination of these has become a promising approach. In the present study, we used a murine tumor model to examine whether spleen-derived DCs transduced with the IL-12 gene could elicit tumor-specific immune responses. BALB/c mice injected peritumorally with adenovirus-mediated IL-12 gene-transduced antigen-unpulsed DCs inhibited the growth of day 5-established subcutaneous CT26 tumors. Splenocytes from treated mice responded specifically to parental tumor cells and showed increased production of interferon gamma (IFN-gamma) and antitumor cytotoxic T-lymphocyte (CTL) activity. Increased numbers of both CD4(+) and CD8(+) T cells were detected in the treated tumors. The inhibition of tumor growth was significantly greater in mice injected with IL-12 gene-transduced DCs than in those injected with IL-12 gene-transduced fibroblasts or the IL-12 gene-encoding adenovirus itself. Taken together, these results indicate that DCs transduced with the IL-12 gene by a recombinant adenovirus are effective in inducing tumor-specific Th1 and CTL responses that inhibit the growth of established subcutaneous tumors.

Soluble Flt-1 gene therapy for peritoneal metastases using HVJ-cationic liposomes

Many studies have reported a close association between VEGF and tumor angiogenesis. The aim of the present study was to evaluate the effectiveness of gene therapy against cancer, including peritoneal metastasis, using a cDNA encoding a soluble type of Flt-1, one of the VEGF receptors. In a peritoneal metastasis model of MKN45 human gastric cancer cells, mice repetitively treated with intraperitoneal injections of HVJ-Fex, a type of HVJ-cationic liposome encapsulating a plasmid expressing soluble mFlt-1, exhibited smaller disseminated foci with fewer microvessels, thus resulting in a significantly longer survival period than the control mice. In another peritoneal metastasis model using HT1080S cells, a clone of HT1080 human fibrosarcoma cells stably transfected with hVEGF, treatments with HVJ-Fex also reduced the growth of disseminated foci without ascites formation. In conclusion, this study demonstrated that the peritoneal metastases of some cancers were largely dependent on VEGF, and that the repeated intraperitoneal transduction of a soluble flt-1 gene using HVJ-cationic liposomes suppressed peritoneal metastases, thereby contributing to a longer survival period.

Uptake by hepatocytes and biliary excretion of intravenously administered polystyrene microspheres in rats

The in vivo uptake by hepatocytes and biliary excretion of fluorescein isothiocyanate-labeled polystyrene microsphere with a particle size of 50 nm (MS-50) after intravenous administration was studied in rats. It was confirmed by using confocal laser scanning microscopy that MS-50 was partially phagocytosed by the hepatocytes and that MS-50 taken up by the hepatocytes existed exclusively inside the cells 1 h after intravenous administration. Studies on the mechanism of the uptake of MS-50 by the hepatocytes using the liver perfusion technique revealed that a process mediated by apo-E was involved. After intravenous administration of MS-50, about 4% of dose was excreted into bile in 24 h. Pharmacokinetic evaluation of the excretion rate of MS-50 into bile showed that the process followed first-order kinetics. Qualitative evaluation of the fluorescence detected in the bile after intravenous administration of MS-50 revealed that the particles were certainly excreted into bile in an intact form. From these results, it was suggested that intravenously administered MS-50 would be partially phagocytosed by hepatocytes through a process mediated by apo-E and that MS-50 ingested by hepatocytes would be partially excreted into the bile.

Age-dependent telomere shortening is slowed down by enrichment of intracellular vitamin C via suppression of oxidative stress

Telomeres in eukaryotic somatic cells are destined to the age-dependent shortening, which has not been demonstrated to correlate to direct lesion of telomeric DNA by reactive oxygen intermediates (ROI); still less explicable is the inhibitory effect of ROI-scavenging on telomere shortening. Here, we succeeded in artificial slowdown of age-dependent telomere shortening to 52-62% of the untreated control, in human vascular endothelial cells, by addition of the oxidation-resistant type of ascorbic acid (Asc), Asc-2-O-phosphate (Asc2P), which concurrently achieved both extension of cellular life-span and prevention of cell size enlargement indicative of cellular senescence. The results are attributable to a 3.9-fold more marked enrichment of intracellular Asc (Asc(in)) by addition of Asc2P, subsequently dephosphorylated before or during transmembrane influx, than by addition of Asc itself, and also attributed to diminution of intracellular ROI to 53% of the control level by Asc2P; telomerase activity was at a trace level and underwent an age-dependent decline, which was significantly decelerated by Asc2P. Thus, age-dependent telomere-shortening can be decelerated by suppression of intracellular oxidative stress and/or by telomerase retention, both of which are achieved by enriched Asc(in) but not by extracellular Asc overwhelmingly more abundant than Asc(in).

[Study on the radiation effects toward function and vessels of parotid gland in rat]

The effect of irradiation on the parotid gland was determined from 99mTc-pertechnetate (99mTcO4-) uptake and the course of vessels in the parotid gland, by investigating the uptake and excretion of 99mTcO4- in 60Co-gamma ray-irradiated rat parotid gland and ovserving the course of blood vessels and the histological changes. 1. In the uptake test, radiation activity of 99mTcO4- taken into the parotid gland per unit weight was the highest three days after irradiation for both 10 Gy (1.68 x 10(5)cpm/g) and 50 Gy (2.05 x 10(5)cpm/g); however, it began to decrease gradually at 7 days after irradiation. 2. In the clearance test, as in the uptake test, the radiation activity of 99mTcO4- per unit weight remaining in the parotid gland after stimulation of secretion, was high at 3 days after irradiation for both 10 Gy and 50 Gy (0.86 x 10(5), 1.28 x 10(5)cpm/g, respectively) and 7 days (0.88 x 10(5), 1.29 x 10(5)cpm/g) after irradiation, and gradually decreasing thereafter. 3. Stimulation-secretion coefficients determined from the ratio of uptake and clearance of 99mTcO4- were lower in all groups with irradiation than in the group without irradiation, with especially low values at 7 and 14 days after radiation. Thus, parotid function declined after irradiation. 4. With respect to the effect of irradiation on blood vessels, mild dilation was observed at 10 Gy at 3 and 7 days after irradiation, then constriction and meandering were noticed. Such changes were greater at 50 Gy than at 10 Gy. 5. Histological changes appeared 6h after irradiation in the 10 Gy- and 50 Gy-irradiation groups. Derangement of cells in the terminal parts, dilation of conduits, and proliferation of connective tissue were observed from 3 days after irradiation. 6. The periodic aid-Schiff (PAS) reaction was decreased in the 10 Gy- and 50 Gy-irradiation groups, with few PAS-positive cells at 28 days after irradiation. In conclusion, the decline in parotid function after 10 Gy- and 50 Gy-irradiation was related to histological changes in the vascular system and glandular tissues.

[Change on the cell proliferation kinetics of the central and peripheral regions of DMBA induced hamster tongue cancer following irradiation]

Cellular changes on the vascular and peripheral sides of DMBA-induced cancer of the tongue in hamsters, were assessed by [3H] thymidine cellular labelling, one and three days after irradiation by 60Co-gamma ray at 20 Gy. The results obtained were as follows: 1) Initial labelling index (L.I.) was high on the vascular side and low on the peripheral side before irradiation. The L.I. on the day following irradiation was decreased was decreased for the whole tumor. The vascular side demonstrated a decrease of about 43% while there were no changes on the peripheral side. This tendency was still observed 3 days after irradiation. 2) Mitosis index (M.I.) were high on the vascular side, and low on the peripheral side before irradiation. On the following day, and three days after irradiation the M.I. was decreased totally, although the decrease was only slight on the vascular side. On the peripheral side, in contrast, the M.I. was increased to about two-fold. 3) There was no difference in the time of cellular rotation (Tc), between vascular and peripheral sides before irradiation, but the Tc on the following day of irradiation was increased by about 3 on both the vascular and peripheral sides of the tumors. In contrast, at three days after irradiation, it was decreased by about 6.5h. 4) There was no difference in the time of preparation for mitosis (Tg2) between the vascular and peripheral sides before irradiation. It was increased by about 2h on both sides on the day following irradiation, and it was increased by about 3h, 3 days after irradiation. 5) Although there was no difference in the time of mitosis (Tm) between both sides, on the day following irradiation, it was increased by about 1.6 times, and 2.1 times, on the vascular and peripheral sides, respectively. A very similar tendency was observed even 3 days after irradiation. 6) There was no difference in the time of DNA synthesis (Ts) between the vascular and peripheral sides of the tumors before irradiation, or at one, or three days after irradiation. 7) Although there was no difference in the time of preparation for synthesis (Tg1), between both sides before irradiation, or on the day following irradiation, it showed a marked decrease of about 90% on both sides of the tumors 3 days after irradiation.

[Ossifying fibroma in maxilla. Report of case]

Since first reported by Montgomery in 1927, ossifying fibroma, a benign neoplasm of bone or bone tissue, has been the subject of numerous studies. In the present paper, a case of ossifying fibroma in a woman is presented. The woman was 49 years old. She visited our clinic with a complaint of swelling in the right maxillary region. Thorough examinations were conducted. From X-ray, CT, scintigraphy and biopsy findings, the case was diagnosed as ossifying fibroma. Under a general anesthetic, the tumor was extirpated. It measured 40 x 40 x 60mm. It's weight, including that of teeth, was 60.5 g. Histopathological examination revealed fibroblasts and hard, bone-like masses of varying shapes in the connective tissue. Nearly one year has elapsed since the surgical operation. The patient is doing well. Since 1957, a total of 107 cases of ossifying fibroma have been reported in Japan. The ages of the patients were mostly between 10 and 49. By sex, 42 were male and 65 female. By region, in 28 case, fibroma occurred in the maxillary part, 68 in the mandibular part, and 11 in the region extending from maxillary to mandibular area. More 70% of the cases were fibroma originating in the molar area.

In vivo and in vitro effects of zinc oxide-eugenol (ZOE) on biosynthesis of cyclo-oxygenase products in rat dental pulp

To determine the in vivo effects of a zinc oxide-eugenol mixture (ZOE) on the cyclo-oxygenase system in dental pulp, we used radioimmunoassay to measure the levels of prostaglandin E2 (PGE2), 13,14-dihydro-15-keto-PG (DHK-PG), thromboxane B2 (TXB2), and 6-keto-PGF1 alpha in the dental pulp of rats. When the dental pulp was irritated by a hole made in the dentin of the mandibular incisors without use of any coolants, the levels of these cyclo-oxygenase products in the pulp were increased to, respectively, 2.8, 1.7, 10.0, and 2.6 times those in the normal pulp at six hr after treatment. In contrast, these increases in cyclo-oxygenase products disappeared immediately when the artificial cavity in the dentin was filled with ZOE (P/L; 1 g/0.25 mL), but were not altered when the cavity was filled with zinc oxidewater (ZOW, 1 g/1.5 mL). Most of the eugenol portion of ZOE was released into the pulp within two hr after the cavity was filled with ZOE. The maximal eugenol content was 35 pmol per mg of pulp. Furthermore, when the cavity was filled either with ZOE or by the addition of 10 mumol/L eugenol to the pulp homogenate, biosynthesis of 14C-6-keto-PGF1 alpha, PGF2 alpha, and PGE2 from 14C-arachidonic acid in the homogenate was inhibited. These results suggest that eugenol released from ZOE in the cavity prepared in the dentin inhibited the biosynthesis of cyclo-oxygenase products during pulp irritation.