Water-soluble taxol conjugates with dextran and targets tumor cells by folic acid immobilization

BACKGROUND

Paclitaxel (taxol) is a very effective anticancer drug. However, the solution used to enhance the water solubility of paclitaxel, a mixture of polyoxyethylene castor oil (Cremphor EL) and dehydrated ethanol, causes irritation. Our aim is to develop a water-soluble taxol with a high anticancer effect.

MATERIALS AND METHODS

Taxol derivatives (conjugation with aminated dextran, Dex-TXL) were synthesized for the water-solublization of taxol and folic acid (FA) was ionically and covalently conjugated with Dex-TXL. In addition, their anticancer activity was investigated in vitro with KB cells (a folate receptor-overexpressing carcinoma cell line of the oral cavity).

RESULTS

The high solubility of Dex-TXL conjugates (2700 times higher than that of intact taxol) needed no additional Cremophor EL or dehydrated ethanol. Dex-TXL showed 2-3 times greater anticancer effect when conjugated with FA.

CONCLUSION

These results suggest that conjugation with dextran and FA could bring about an improvement in taxol anticancer therapy.

Development of a new tissue-engineered sheet for reconstruction of the stomach

We have developed tissue-engineered digestive tracts composed of collagen scaffold and an inner silicon sheet and successfully used it to repair defects in parts of the esophagus, stomach, and small intestine. However, some improvements were demanded for clinical usage because the silicon sheet presented technical difficulties for suturing and endoscopic removal. New tissue-engineered sheet (New-sheet) was composed of a single-piece and reinforced collagen scaffold with biodegradable copolymer. One beagle dog was used to evaluate whether New-sheet could withstand suturing in comparison with native digestive tracts using a tensile tester. Seven beagle dogs had a 5-cm circular defect created in the stomach. New-sheet soaked with autologous peripheral blood or bone marrow aspirate was sutured to the gastric wall. Endoscopic, histological, and immunohistochemical assessment was performed to evaluate regeneration of the stomach up to 16 weeks. Tensile strength testing showed that the mucosal side of New-sheet had strength almost equivalent to the mucosa of the esophagus (P = 0.61). Endoscopically, regeneration of the mucosa started from the circumference after 4 weeks, but a small linear ulcer was still evident at 16 weeks. The regenerated stomach shrank by 60-80% of its original size and histologically showed villous mucosa and underlying dense connective tissue. Immunohistochemically, the regenerated area expressed alpha-smooth-muscle actin but was negative for basic calponin, irrespective of the source of soaked blood. New-sheet shows sufficient strength for suturing, no dehiscence, and better biocompatibility for clinical use, although further examination will be necessary to create a functional digestive tract.

Neuroendoscopic trans-third ventricle approach for lesions of the ventral brainstem surface

Due to the establishment in recent years of neuroendoscopic third ventriculostomy (ETV), it has become possible during ETV to observe the ventral brainstem surface--particularly the prepontine cistern--in a minimally invasive manner via the third ventricular base with a neuroendoscope. As an adaptation of that technique in this study, we investigated a neuroendoscopic trans-third ventricle approach (ETTVA), which accesses lesions of the ventral brainstem surface with a neuroendoscope inserted via the stoma of the third ventricular floor. Our study included 6 cases, including one case each of neurenteric cyst, chordoma, pontine glioma (astrocytoma), ecchordosis physaliphora, endodermal cyst, and cystic schwannoma. Surgical operations performed by ETTVA included 3 cases of tumor resection, 2 cases of tumor biopsy, and 1 case of cyst puncture and aspiration. There were no complications accompanying ETTVA. Out of the 6 cases, only 1 required additional surgical treatment following ETTVA surgery. In the other 5 cases, no additional surgical procedures were performed. This study showed that ETTVA allowed access to the prepontine cistern quickly and in a minimally invasive manner. In selected cases, ETTVA can offer a new approach to these lesions.

Adiponectin suppresses colorectal carcinogenesis under the high-fat diet condition

BACKGROUND AND AIMS

The effect of adiponectin on colorectal carcinogenesis has been proposed but not fully investigated. We investigated the effect of adiponectin deficiency on the development of colorectal cancer.

METHODS

We generated three types of gene-deficient mice (adiponectin-deficient, adiponectin receptor 1-deficient, and adiponectin receptor 2-deficient) and investigated chemical-induced colon polyp formation and cell proliferation in colon epithelium. Western blot analysis was performed to elucidate the mechanism which affected colorectal carcinogenesis by adiponectin deficiency.

RESULTS

The numbers of colon polyps were significantly increased in adiponectin-deficient mice compared with wild-type mice fed a high-fat diet. However, no difference was observed between wild-type and adiponectin-deficient mice fed a basal diet. A significant increase in cell proliferative activity was also observed in the colonic epithelium of the adiponectin-deficient mice when compared with wild-type mice fed a high-fat diet; however, no difference was observed between wild-type and adiponectin-deficient mice fed a basal diet. Similarly, an increase in epithelial cell proliferation was observed in adiponectin receptor 1-deficient mice, but not in adiponectin receptor 2-deficient mice. Western blot analysis revealed activation of mammalian target of rapamycin, p70 S6 kinase, S6 protein and inactivation of AMP-activated protein kinase in the colon epithelium of adiponectin-deficient mice fed with high-fat diet.

CONCLUSIONS

Adiponectin suppresses colonic epithelial proliferation via inhibition of the mammalian target of the rapamycin pathway under a high-fat diet, but not under a basal diet. These studies indicate a novel mechanism of suppression of colorectal carcinogenesis induced by a Western-style high-fat diet.

[Mature teratoma in the posterior mediastinum showing the fatty density on the chest computed tomography]

We reported a case of posterior mediastinal mature teratoma. A 16-year-old woman was referred for further investigation of a left paravertebral mass detected on chest roentgenogram. The defined mass was located above the diaphragm and showed homogeneous fat density on computed tomography (CT) and hypersignal intensity on both T1 weighted images and T2 weighted images on magnetic resonance imaging (MRI). Radiologically, there was a mimicking foci of calcification. The mass was histologically diagnosed as mature teratoma.

Testing the druggable endothelial differentiation gene 2 knee osteoarthritis genetic factor for replication in a wide range of sample collections

OBJECTIVES

To replicate a previously reported association with osteoarthritis (OA) of the promoter single nucleotide polymorphism (SNP) rs10980705 in the endothelial differentiation gene 2 (EDG2).

METHODS

Five collections of samples, four from Europe and one from China, were studied. They included patients with 3 OA phenotypes: 1501 with knee OA, 1497 with hip OA and 376 with generalised OA. A total of 2521 controls were also studied. Allele and genotype frequencies of the rs10980705 SNP were analysed in each individual sample collection and in pooled data. In addition, a meta-analysis to incorporate results from the original Japanese report was performed.

RESULTS

The association of the rs10980705 SNP with knee OA was not replicated in any of the five sample collections studied or in their combined analysis (odds ratio (OR) 1.10, 95% CI 0.98 to 1.22; p = 0.10). Meta-analysis of all data, including the original Japanese study, did show association with knee OA (OR 1.15, 95% CI 1.06 to 1.26; p = 0.002) but the effect was accounted for by the Japanese data and was less significant than the original report. No association was found with hip OA or with generalised OA.

CONCLUSIONS

The original report of a promising genetic association between a druggable G-protein coupled receptor, EDG2, and knee OA has not been replicated. This lack of replication could be due to a modest effect of the promoter polymorphism that will require even larger studies (the winners curse) although a more pronounced effect in the Asian population vs Europeans cannot be excluded.

[Pulmonary metastatic meningioma 26-years after craniotomy]

A 68-year-old male, pointed out of bilateral lung tumors, was hospitalized for the evaluation of multiple lung tumors. Chest computed tomography demonstrated 10 x 10 mm and 30 x 60 mm tumors in left lower lung and a 16 x 16 mm tumor in right lower lung. He was operated under the diagnosis of intracranial meningioma 26-years ago. For purpose of diagnosis, partial resections of left lower lung were performed, and then these tumors were diagnosed as pulmonary metastasis of intracranial meningioma. This is a very rare case of pulmonary metastasis of meningioma 26-years after craniotomy.

Purification and characterization of a novel esterase (beta-hydroxypalmitate methyl ester hydrolase) and prevention of the expression of virulence by Ralstonia solanacearum

AIMS

To screen novel micro-organisms and enzymes capable of degrading 3-hydroxypalmitic acid methyl ester (3-OH PAME), the quorum-sensing signal molecule (quormone), which regulates the virulence of Ralstonia solanacearum.

METHODS AND RESULTS

Ideonella sp. 0-0013, a betaproteobacterium isolated from soil using the selective-enrichment culture method, was grown on plates containing 3-OH PAME as its main carbon source. beta-Hydroxypalmitate methyl ester hydrolase (betaHPMEH) purified from the supernatant of the Ideonella sp. 0-0013 culture exhibited high hydrolysing activity towards the ester bond of 3-OH PAME and eliminated the 3-OH PAME activity, thereby reducing the virulence of R. solanacearum. An Escherichia coli transformant of the betahpmeh gene expression vector degraded 3-OH PAME, and the crude enzyme from the transformant inhibited in vitro production of the R. solanacearum exopolysaccharide (EPS).

CONCLUSIONS

The ability of betaHPMEH to hydrolyse 3-OH PAME inhibited the production of EPS by the R. solanacearum wild-type strain, indicating that betaHPMEH inhibits the effects of activation of virulence genes. This ability will be potentially useful for pest control of the wilt disease caused by this bacterium.

SIGNIFICANCE AND IMPACT OF THE STUDY

This enzyme is the first protein that has been found to degrade a quormone other than N-acyl homoserine lactone.

231 STAGE-DEPENDENT CHANGES OF IP3R1 PHOSPHORYLATION DURING IN VITRO MATURATION AND DEVELOPMENT IN PIG OOCYTES

During fertilization in mammalian species, a sperm-induced intracellular Ca2+ signal [Ca2+] is well suited to mediate the highly specialized spatiotemporal patterns of [Ca2+]i responses that underlie fertilization. Recently, we demonstrated that the expression pattern of inositol 1,4,5- triphosphate receptor type 1 (IP3R1) did not change during in vitro maturation and parthenogenetic activation in mouse oocytes; however, the phosphorylation status of IP3R1 depended on the cell cycle during meiosis. Moreover, it was shown that IP3R1 phosphorylation played a crucial role in the induction of [Ca2+]i oscillations (Lee et al. 2006 Development 133, 4355–4365). In other species, expression of IP3R1, especially phosphorylation levels of IP3R1 during meiosis, has not been examined. The aim of this study was to examine the kinetics of IP3R1 expression and phosphorylation during in vitro maturation and activation in pig oocytes. Immature oocytes at the germinal vesicle (GV) stage were collected from ovaries and cultured in modified NCSU37 up to 48 h. After culture, cumulus cells were removed and oocytes were parthenogenetically activated by 25 µm Ca2+ ionophore for 3 min and 2 mm 6-DMAP for 6 h. After activation, oocytes were further cultured up to the 2-cell stage. Groups of 30 oocytes were collected at each culture period for detection of IP3R1. According to our previous report in the mouse, IP3R1s were detected by western blotting using MPM-2 and Rbt03 antibody for detecting IP3R1 phosphorylation and total IP3R1 expression, respectively (Lee et al. 2006). In pig oocytes, IP3R1 was abundantly expressed at the GV stage. The total level of IP3R1 expression did not change during in vitro maturation or after activation. However, phosphorylated IP3R1 levels increased by 24 h although they were undetectable at the start of culture. Phosphorylation of IP3R1 reached maximal levels at 36 h. After activation, phosphorylation levels decreased progressively until the pronuclear (PN) stage. Phosphorylation of IP3R1 was observed at mitosis I to some extent. From these results, we detected for the first time IP3R1 expression and phosphorylation in pig oocytes. Moreover, our data suggest that phosphorylation of IP3R1 is dependent on cell cycle at least during meiosis, especially M-phase, as already shown for mouse oocytes. In vitro kinase assays for p34cdc2 kinase and MAPK will be carried out to clarify the relationship between IP3R1 phosphorylation and M-phase kinase(s).

Effects on gingival cells of hydroxyapatite immobilized on poly(ethylene-co-vinyl alcohol)

Hydroxyapatite was immobilized on poly(ethylene-co-vinyl alcohol) (EVA) by alternate soaking in aqueous CaCl(2) and Na(2)HPO(4) solutions, followed by carboxyl groups introduction through ozone exposure in order to investigate the nature of the gingival cells, to control their proliferation and properties and to develop a highly organized hybrid implant possessing periodontium. Human gingival cells were cultured on the ozone-exposed EVA, collagen-immobilized EVA, hydroxyapatite-immobilized EVA, and a conventional tissue culture dish. Cell proliferation was highest on the tissue culture dish and lowest on the hydroxyapatite-immobilized EVA. The results of RT-PCR of gingival cells on hydroxyapatite-immobilized EVA shows that mRNAs expressed in bone and periodontal ligament were determined. Furthermore, alkaline phosphatase activity and ELISA assay revealed that gingival cells acquired the osteoblastic properties when cultured on hydroxyapatite-immobilized EVA, suggesting that the periodontium might be regenerated around implants using gingival cells.

[Video-assisted thoracoscopic surgery for ligation of anomalous systemic arterial supply to pulmonary sequestration]

A 52-year old female with anomalous systemic arterial supply to pulmonary sequestration was reported. The patient was admitted because of an abnormal lung shadow on chest X-ray film. Computed tomography (CT) showed an anomalous systemic arterial supply to pulmonary sequestration of the left lower lung without lung infection. Video-assisted thoracoscopic surgery for ligation of the anomalous systemic artery was performed. Postoperative course has been uneventful for 14 months after surgery. Blood supply increased to the left lower lung by 3-dimensional CT after surgery. The ligation of anomalous systemic arterial is enough for this disease.

Creation of a uniform pleural defect model for the study of lung sealants

OBJECTIVE

Animal models are indispensable for the development of new therapeutic methods for the closure of alveolar air leakage. However, it is difficult to create a uniform pleural defect model. The purpose of this study was to establish an appropriate animal model for assessing the efficacy and histotoxicity of synthetic sealants for lung surgery.

METHODS

Nine beagle dogs were used to evaluate the pleural defect model in comparison with conventional resection procedures. A donut-shaped silicon ring with an inner diameter of 15 mm was placed on the pleura, and 0.1 mL of cyanoacrylate was dropped into the ring. A pleural defect was created by sliding a microtome blade just beneath the polymerized cyanoacrylate. Hemostasis was performed by pressure with a sponge.

RESULTS

Morphologically, round areas of the pleura were uniformly resected with our procedure. The resected tissue consisted of pleura and thin underlying lung parenchyma. Among the results from 3 surgeons, there were no significant differences in the mean time required for hemostasis (P = .69), the mean thickness of the resected tissue (P = .13), and the mean amount of air leakage from the resected area (P = .19). No penetration of cyanoacrylate into the lung parenchyma was evidenced by immunofluorescence microscopy. Histologically, when the pleura was resected without using cyanoacrylate, a thick fibrocellular layer extended to the lung parenchyma. Furthermore, severe fibrosis was observed when electrocautery was used for hemostasis. However, when the pleura was resected using cyanoacrylate, the normal alveolar structure was preserved.

CONCLUSIONS

Our uniform pleural defect model using cyanoacrylate may be feasible for the evaluation of synthetic sealants for alveolar air leakage.

Ab initio x-ray absorption near-edge structure study of Ti K-edge in rutile

This work reports a theoretical x-ray absorption near-edge structure (XANES) spectroscopy study at the Ti K-edge in TiO(2) rutile. We present detailed ab initio computations of the Ti K-edge XANES spectrum performed within the multiple-scattering framework. An extensive discussion is presented concerning the size of the cluster needed to reproduce the experimental spectrum, especially regarding the split main absorption line. In addition, the role of the exchange and correlation potential (ECP) in reproducing all the experimental XANES features is discussed. The best agreement between experimental data and computations is obtained by using real ECP potentials, i.e. the energy-dependent Dirac-Hara exchange potential, or by using only the real part of the energy-dependent Hedin-Lundqvist complex potential, together with an additional imaginary constant to account for the core-hole lifetime and the experimental resolution. The addition of the imaginary part of the HL potential worsens the agreement between the experimental and calculated spectra, indicating the failure of the complex part of the Hedin-Lundqvist ECP in accounting for the electron damping in these systems.

High production of (2s,3s)-3-hydroxy-2-methylbutanoate by immobilized plant cells of Marchantia polymorpha

Cultured plant cells of Marchantia polymorpha were examined for their ability to reduce beta-keto ester, 2-methyl-3-oxobutanoate. The cells reduced ethyl 2-methyl-3-oxobutanoate to predominantly yield the anti-product, ethyl (2S,3S)-3-hydroxy-2-methylbutanoate, with 92% diastereomeric excess and over 99% enantiomeric excess. The use of immobilized cells of M. polymorpha in calcium alginate gel improved the diastereomeric excess of the product (97% de). In addition, the large-scale reduction of 75 g of ethyl 2-methyl-3-oxobutanoate with immobilized M. polymorpha gave the product with 97% de and >99% ee in 92% yield.

[Mediastinal recurrence of breast cancer suspecting mediastinal fibrosis]

A 63-year-old female, who had undergone a modified radical mastectomy for breast cancer at the age of 45, was suffered from trachyphonia due to left recurrent nerve paralysis at the age of 53. She presented left phrenic nerve paralysis and dysphagia at the age of 61. Computed tomography (CT) revealed mediastinal fibrosis, stenosis of esophagus and superior vena cava, and slight lymph nodes swelling. Video-assisted thoracoscopic mediastinal biopsy was performed and the mediastinal fibrosis was diagnosed as recurrence of breast cancer 17 years after the breast cancer operation. She underwent mediastinal radiation and chemotherapy for mediastinal recurrence and stenting for esophageal stenosis.