A calorimetric study of the interaction of synthetic phospholipid liposomes with lipid-soluble small molecules used as dental materials and devices

The interaction of 22 lipid-soluble small molecules, widely used in dental materials and devices, with synthetic phospholipid liposomes, was investigated by the application of differential scanning calorimetry (DSC), in order to clarify the mechanism of small molecules in biological systems. Dimyristoyl phosphatidyl choline (DMPC) and dipalmitoyl phosphatidyl choline (DPPC) were used as lipids. The interaction of various monomers with liposomes has been reported by us in this journal. In this experiment, various compounds such as redox-initiator, photo-initiator or photo-sensitizer, inhibitor, root-canal disinfectant, cement-base materials (eugenol and 2-ethoxybenzoic acid) etc., were investigated. From changes in the phase transition temperature (T), enthalpy (delta H kcal mol-1) and H/HHW values of both DMPC and DPPC liposomes induced by these molecules, it was concluded that aromatic tertiary amine, benzoyl peroxide and hydroquinone monomethyl ether had a relatively large effect on liposomes, and that in phenol derivatives, m-cresol and p-chlorophenol had a large effect on liposomes compared to phenol. Eugenol used as dental cement also had a large effect on liposomes due to its high hydrophobicity. Changes in the transition properties of liposomes induced by small molecules (characterized by shift of T to a lower temperature, an increase or decrease in cooperativity (H/HHW), and a decrease in delta H of a endothermic peak) seemed to be related to biological activities.     

Purification and characterization of gene 17 product of bacteriophage T3

Tail fiber proteins of bacteriophage T3 are encoded by gene 17. By using in vitro complementation for phage assembly as an assay, the product of gene 17 (gp17) was purified to near homogeneity from cells infected with a double mutant of T3 defective in DNA synthesis and head assembly. The purified gp17 consists of a single polypeptide having a molecular weight of 67,000. Electron microscopy of the purified gp17 showed a fiber structure similar to the tail fiber in a virion. The subunit structure of the purified, native gp17 was analyzed by using a crosslinking agent, dimethyl suberimidate. The results indicate that native gp17 is a trimer of gp17 monomer.     

Effect of etodolac on type-II collagen-induced arthritis in mice

We tested the effect of etodolac on the development of type-II collagen-induced arthritis in DBA/1J mice. It was administered orally once daily for 35 days after the primary immunization with type-II collagen. Etodolac (10 mg/kg) significantly inhibited the development of signs of arthritis on day 28 to day 35. Indomethacin (1 mg/kg) also significantly inhibited it on day 29 to day 34. Radiographic examination showed that etodolac (10 mg/kg) significantly prevented the development of osteopenia, bone erosion and new bone formation of the joints on day 35, while indomethacin (1 mg/kg) significantly prevented only the development of bone erosion. Histopathological examination showed that both etodolac (10 mg/kg) and indomethacin (1 mg/kg) significantly prevented the development of synovitis, erosion of cartilage of the joints and bone destruction of the limbs on day 35. Etodolac and indomethacin did not affect the serum level of anti-type-II collagen antibodies. These results suggest that etodolac and indomethacin suppress type-II collagen-induced arthritis without affecting humoral immune responses.     

Isolation and characterization of bacteriophage T3/T7 hybrids and their use in studies on molecular basis of DNA-packaging specificity

In vitro DNA-packaging systems of bacteriophages T3 and T7 packaged homologous DNA more efficiently than heterologous DNA. Packaging of phage DNA proceeds by way of concatemeric intermediates (H. Fujisawa, J. Miyazaki, and T. Minagawa (1978), Virology 87, 394-400). The conversion of mature homologous and heterologous DNAs to concatemers was efficient in both the T3- and T7-packaging systems. In vitro complementation experiments indicate that the gene 19 product (gp19) specifies which DNA enters the capsid. To identify DNA regions recognized by the packaging systems, T3/T7 hybrids were constructed and physical maps of the hybrid DNAs were determined by restriction enzyme analysis. By comparing restriction maps and in vitro packaging of hybrid DNAs, it is concluded that the sequence responsible for specificity of DNA packaging is confined within 5% of the ends of the T3 and T7 genomes.     

Expression of cyclin D1, retinoblastoma gene protein, and p16 MTS1 protein in atypical adenomatous hyperplasia and adenocarcinoma of the lung

 To clarify the events leading to the disruption of cell growth control that occurs during the development of pulmonary adenocarcinoma (AC), we used immunohistochemistry to evaluate the expression of G1 cycle regulators, cyclin D1, Rb protein (pRb), and p16 MTS1 protein and the tumour proliferation marker, Ki 67, both in AC of the lung and in its precursor lesion, atypical adenomatous hyperplasia (AAH). The frequency of lesions with cyclin D1 overexpression was relatively high in AAH (47–89%), but was decreased in early AC (28%) and overt AC (35%). The loss of pRb expression was rare in both AAH (0–18%) and early AC (0%), and was infrequent even in overt AC (13%). The loss of p16 expression was also relatively infrequent in both the premalignant and the malignant lesions (11–25%). Our results suggest that overexpression of cyclin D1 is an early event and plays an important part in tumorigenesis in the case of lung AC. However, cyclin D1 overexpression is not required for the development and maintenance of a malignant phenotype. It is likely that some cyclin D1-independent pathways other than Rb and p16 abnormalities have an important role in the malignant transformation from AAH to early AC. Received: 8 July 1997 / 26 September 1997     

Association of genetic variation of the RIL gene,encoding a PDZ-LIM domain protein and localized in 5q31.1, with low bone mineral density in adult Japanese women

Twin and family studies had shown that genetic factors are important determinants of bone mass. Multiple genes might be involved. One candidate gene, the reversion-induced LIM gene (RIL), is a PDZ and LIM-domain-containing protein and has been localized within the cytokine cluster of chromosome 5 (5q31.1). In a genetic study of 370 adult Japanese women, we investigated the correlation between radial bone mineral density (BMD) and a genetic variation (−3333T→C) of the 5'-flanking region of RIL gene. A significant association was identified between the RIL variation −3333T→C and radial BMD (r=0.15, P=0.003). The variation of the RIL locus may be an important determinant of osteoporosis.     

PROGRESSIVE MULTIFOCAL LEUKOENCEPHALOPATHY

Clinical, light- and electron microscopic, and immunohistochemical findings of a 44-year-old woman with progressive multifocal leukoencephalopathy were presented. Autopsy revealed a wide distribution of the demyelinating lesion in the cerebrum, cerebellum, brain stem and spinal cord, and intranuclear inclusion bodies and papova-like virions in transmission electron microscopy in the nuclei of oligodendrocytes. SV40 antigen was immunohistochemically detected in these inclusion bodies. The widespread extension of the lesions seemed to correlate with the duration of the patient's illness. The prolongation of the clinical course in this case may be dependent upon the lack of serious underlying diseases except for a small nodule of thyroid carcinoma, SV40 infection rather than JC virus infection and/or improved care of that kind of patient.     

The proliferating cell nuclear antigen (PCNA) index correlates with the grade of cytologic atypia in well-differentiated early adenocarcinomas of the large intestine

Well-differentiated colorectal adenocarcinomas are subclassified into carcinoma with high-grade atypia (CAH) and carcinoma with low-grade atypia (CAL) based on their cellular atypia. It is proposed that CAH and CAL are different in histologic prognostic factors and that the former should be regarded as carcinoma with high-grade malignancy and the latter as low-grade malignancy. In this study, the differences in cell-proliferative activity between CAH and CAL were examined using a monoclonal antibody to the proliferating cell nuclear antigen (PCNA). The PCNA index and mitotic index of 27 early colorectal carcinomas (9 CAL, 5 CAH, and 13 carcinomas with mixed low- and highgrade atypia) was evaluated in relation to their depth of invasion. In intra-mucosal lesions, both indices were higher in CAH (78%, 0.89%) than in CAL (68%, 0.47%; P <0.01). In lesions invading into the submucosa, the PCNA and mitotic indices were also higher in CAH (7596, 0.65%) than in CAL (35%, 0.19%; P <0.01). A significant correlation was observed between the PCNA index and the mitotic index in the mucosal lesions (P<0.05). These results indicate that CAH has a higher proliferative activity than CAL, and support the current authors' proposal that CAH is a high-grade malignancy and CAL a low-grade malignancy.     

p53 protein overexpression and K-rascodon 12 mutation in pancreatic ductal carcinoma: Correlation with histologic factors

The correlation of p53 protein overexpression and the K-ras codon 12 mutatlon wlth histologlc type, grade of cytologic atypla, depth of lnvasion and other histologlc prognostic factors was studied In paraffin sectlons from 43 ductectatic-and 70 solid-type pancreatic ductal carcinomas. Overexpression of p53 was found in 23.3% (10143) of ductectatic carcinomas (17.2% of intraductal and 35.7% of lnvaslve carclnomas) and in 61.4% (43/70) of solid carcinomas. In ductectatic cancers, p53 overexpression was detected In 14.8% (4/27) of carcinomas wlth lowgrade atypla (CAL), 50.0% (5110) of carcinomas wlth high-grade atypla (CAH) and in 16.7% (In) of mixed low- and hlgh-grade cancers. In the last group, expression was restricted to an area of CAH. In solld cancers, p53 overexpression did not dlffer by histologic type or grade. Overexpresslon of p53 and K-ras mutatlons did not correlate with histologlc prognostic factors (lymphatic, venous and perineural Invasion, and lymph node metastasls) in ductectatlc and solld cancers or depth of invasion of solld carclnomas. Our data suggest that p53 alteratlon occurs at an early intraductal stage of solld carcinoma, irrespectlve of cellular atypla, but Is low in ductectatic CAL and becomes hlgher In ductectatlc CAH. K-ras mutatlon, present In a high percentage of tumors of all groups and not correlating with the factors above, showed no changes In frequency with tumor progression.     

The relationship of VEGF and PGE2 expression to extracellular matrix remodelling of the tenosynovium in the carpal tunnel syndrome

Tenosynovial thickening within the confined space of the carpal tunnel is thought to be the cause of the carpal tunnel syndrome (CTS). However, little is known about the pathological mechanism of tenosynovial thickening. In this study, the role of prostaglandin E(2) (PGE(2)) and vascular endothelial growth factor (VEGF) (two representative molecules that can induce oedema by increasing vascular permeability) was analysed in CTS by using immunohistochemistry and enzyme-linked immunosorptive assay (ELISA). Expression of these molecules was compared with the patients' clinical histories and a temporary increase in production of these molecules was found in cells within the vessels and synovial lining during the intermediate phase of the syndrome when the histology of the tenosynovium changes from oedematous to fibrotic. Statistical analysis clearly demonstrated that there is a close correlation between the expression of PGE(2) and VEGF. Furthermore, immunohistochemical analysis with anti-proliferating cell nuclear antigen (PCNA) revealed that the area with distinct VEGF expression closely matched the area where endothelial cells, vascular smooth muscle cells, and synovial lining cells proliferate. In contrast, despite marked alteration in the extracellular matrix (ECM) component of the tenosynovium, the fibroblasts responsible for most ECM framework production do not proliferate during any phase of CTS. Histological analysis demonstrated that angiogenesis takes place only during the intermediate phase. Since clusters of capillaries and arterioles are often surrounded by type III collagen-rich, disorganized, degenerate connective tissue, which contains fewer fibroblasts than normal, angiogenesis appears to take place as a part of a regenerative reaction that results in fibrosis. These findings strongly indicate that both PGE(2) and VEGF are expressed in the tenosynovium in CTS during the intermediate phase and induce the histological changes seen in the tenosynovium.