Probing local structure of glass with orientation-dependent luminescence

The local ordering of particles is considered an important process in glass transition. Ordering is usually observed in simulation and micrometer-sized colloid. However, clear information on local ordering at the molecular level is difficult to obtain experimentally. In this study, we prepared an easily glass-forming fluorophore with a color change owing to the intermolecular arrangement in the liquid, glass, and crystal states. The bathochromic shifts of the photoluminescence spectra indicated a change in the intermolecular orientation upon immediate cooling of the melt. The recovery of the spectra by successive heating indicated that rotation contributed to the change in the intermolecular orientation. The orientation in the glass was distinct from that during crystal growth, which was observed as a slow bathochromic shift by maintaining the temperature between the melting points of the blue- and green-luminescent crystals obtained from dichloromethane/ethanol and dichloromethane/hexane, respectively. Our results demonstrate that the anisotropic interaction between glass-forming luminophores is useful for uncovering molecular-level events in the glassy state.

Copper-Catalyzed Single C-H Amination of 8-Aminoquinoline-Directed Ferrocenes

An unprecedented copper-catalyzed C-H monoamination of ferrocenes directed by an 8-aminoquinoline amide directing group is described. This reaction proceeds in the presence of a catalytic amount of copper catalyst with both cyclic and acyclic amines to afford the various aminoferrocenes. The C-H amination of ortho-substituted ferroceneamides was also achieved, enabling rapid access to multisubstituted ferrocenes that are useful for developing new functional molecules.

Intra- and intermolecular interaction of anthracene moieties in 7,8-disilabicyclo[3.3.0]octadienyl-bridged bisanthracenes

V-shaped 9-anthrylarylsilane dimers prepared through ruthenium-catalyzed C–H cleavage showed excimer emission and bathochromic shifts by promoted contact of π-orbitals.

Twisted Polycyclic Aromatic Systems Prepared by Annulation of Bis(arylethynyl)arenes with Biphenylboronic Acids

Twisted polycyclic aromatic hydrocarbons (PAHs) were prepared by the successive rhodium-catalyzed annulation and dehydrogenative cyclization of bis(arylethynyl)arenes with di-tert-butylbiphenyl-2-ylboronic acid. The molecular structures of the PAHs were determined by single-crystal XRD analysis. The PAHs showed up to four fjord regions, and the twisting angle was 46.7°. The nonplanarity (NP) and harmonic oscillator model of aromaticity (HOMA) were calculated by using the structural data obtained from XRD analysis. The PAHs derived from dialkynyl naphthalenes showed low planarity and HOMA of the central ring. The optical properties of the PAHs were investigated by UV/Vis absorption and fluorescence spectroscopy analyses. The absorption and emission maxima of the PAHs with a larger planar region appeared at a longer wavelength. DFT calculations support that the absorption band at λ≈450 nm can be mainly attributed to the HOMO-LUMO transition.

Synthesis of π-Conjugated Polymers Containing Benzodipyrrole Moieties in the Main Chain through Cleavage of C-H Bonds in 1,4-Bis(acetylamino)benzene

Rhodium-catalyzed copolymerization between 1,4-bis(acetylamino)benzene and diynes through C-H bond cleavage afforded π-conjugated polymers containing benzodipyrrole moieties. The polymers with substituted benzene units exhibited nearly the same absorption peaks and HOMO levels. Fluorenone and benzothiadiazole moieties can be also introduced as electron-acceptor units to the main chain by polymerization in tert-amyl alcohol and tetrahydropyran as mixed solvent, leading to absorption at longer wavelength.

Integration of benzo[h]quinoline and π-extended dibenzo[b,f]silepins on pentacoordinate silicon

We investigated the relationship between the chemical structure involving the pentacoordinate silicon and the electronic properties of the molecules.

Synthesis of π-conjugated polymers containing aminoquinoline-borafluorene complexes in the main-chain

The regulation of electron transfer between a conjugated polymer and ligands orthogonally connected to the main-chain is reported. Poly(arylene-ethynylene)s containing aminoquinoline-borafluorene complexes in the main-chain are synthesized in good yields by a Sonogashira-Hagihara coupling. Single crystal X-ray analysis of a model compound has elucidated the complex's structure in which the aminoquinolate moiety and the borafluorene ring are connected directly and orthogonally. Moreover, the optical properties of the polymers are characterized by UV-vis absorption and photoluminescence spectra. Perfluorinated alkyl chain-containing polymers show strong emission, while hydrocarbon chain-containing ones exhibit only a slight emission. DFT calculation suggests that an electron transfer from the excited main-chain to the aminoquinolate ligand is suppressed because of the lowered LUMO level by introducing the electron withdrawing groups, resulting in the significant emission.

Molecular cloning and characterization of mouse Tspan-3, a novel member of the tetraspanin superfamily, expressed on resting dendritic cells

Dendritic cells (DCs) are the most potent antigen-presenting cells and play an essential role for triggering T-cell-mediated immune responses. In search for novel cell surface molecules expressed on DCs involved in T cell priming by representational differential analysis, we identified a mouse homologue of Tspan-3 (mTspan-3), a novel member of the tetraspanin superfamily. The mTspan-3 consists of four hydrophobic, putative transmembrane regions, forming a small and a large extracellular loop, with short intracellular amino and carboxil tails. Although the mTspan-3 is expressed on a variety of immune cell types including resting DCs, its expression on DCs is downregulated during activation induced by cross-linking CD40 with anti-CD40 monoclonal antibody. These results suggest that mTspan-3 may be involved in the function of DCs in association with T cell stimulation.

Virtual pancreatoscopy of mucin-producing pancreatic tumors

We used computer-based virtual endoscopy techniques as a novel approach to clarify the three-dimensional (3D) surgical anatomy of the pancreas and of mucin-producing pancreatic tumors. Thirteen cases (18 lesions) of mucin-producing pancreatic tumors were investigated by virtual pancreatoscopy. Virtual endoscopic images were generated with virtual endoscopy software application on UNIX workstations. We created surface-rendered virtual endoscopic images derived from a computer reconstruction of the cross-sectional magnetic resonance imaging data. Virtual endoscopy could visualize the surfaces of the pancreatic duct and the bile duct, and also demonstrated all cystic tumors. The surfaces of malignant mucin-producing pancreatic tumors were illustrated as being more irregular than those of benign lesions. The virtual endoscopic technique could demonstrate not only a surface-rendered endoscopic image of the tumors but also a 3D reconstructed image of the pancreas. The relationship to anatomic structures located outside the surfaces is continuously maintained and displayed at the same time. Virtual pancreatoscopy was useful for surgical planning of minimally invasive resection of the pancreas.

Inferior head resection of the pancreas for intraductal papillary mucinous tumors

BACKGROUND

Patients with intraductal papillary mucinous tumor have a favorable prognosis after surgical treatment. When this neoplasm is located in the head of the pancreas, resection has conventionally required pancreatoduodenectomy. Although pancreatoduodenectomy can now be performed with a low mortality rate, morbidity still occurs frequently.

METHODS

Between November 1982 and January 1999, 38 intraductal papillary mucinous tumors of the pancreas were resected at the Chiba University Hospital. Seven patients (18%) underwent inferior head resection of the pancreas. In this preliminary study, the operative technique is presented, and its efficacy in improvement of quality of life is evaluated.

RESULTS

Patients with intraductal papillary mucinous tumor underwent resection with no perioperative mortality. After discharge from hospital, 6 patients who underwent inferior head resection were still alive without recurrent disease after a median follow-up of 3 years. However, 1 patient developed peritoneal dissemination and died 18 months after inferior head resection. Patients had regained 98% of preoperative weight 1 year after inferior head resection. N-benzoyl-L-tyrosyl-p-amino-benzoic acid (BT-PABA) excretion test showed the same value before (73%) and after (73%) inferior head resection (n = 7). Pancreatic fistulas occurred more frequently after inferior head resection (38%), but the incidence of major complications was similar between inferior head resection and other types of pancreatic head resection.

CONCLUSIONS

Pancreatic function was well preserved, and patients regained 98% of preoperative weight after inferior head resection of the pancreas. The authors concluded that the limited involvement of intraductal papillary mucinous tumors enables the surgeons to perform inferior head resection of the pancreas.

Intraductal papillary mucinous tumors of the pancreas

BACKGROUND

An increasing number of intraductal papillary mucinous tumors of the pancreas have been reported in recent years. The indolent character and favorable prognosis of this neoplasm have been described.

METHODS

Intraductal papillary mucinous tumors were classified into main duct type (n = 8) and branch type (n = 28) according to the dominant location of the tumor. This single-institute study examined the clinicopathological features and outcome after surgical resection in patients with intraductal papillary mucinous tumors.

RESULTS

The gender, age, tumor size, and prognosis were quite similar for the main duct type and branch type groups. Branch type tumors were more frequently located in the head of the pancreas than were main duct type tumors. Histological examination revealed that 88% of main duct type tumors were adenocarcinomas; however, only 46% of branch type tumors were adenocarcinomas. Five-year survival rates for the patients with all main duct type tumors (n = 8), main duct type adenocarcinoma (n = 7), all branch type tumors (n = 28), and branch duct adenocarcinoma (n = 13) were 100%, 100%, 90.6%, and 90.9%, respectively.

CONCLUSIONS

Intraductal papillary mucinous tumors had a favorable prognosis after surgical treatment. A curative pancreatectomy should be indicated for this localized malignant tumor.

Gilvusmycin, a new antitumor antibiotic related to CC-1065

A new antitumor antibiotic gilvusmycin was isolated from the culture broth of Streptomyces sp. QM16. The structure of gilvusmycin was related to CC-1065 and determined by NMR spectral analysis. Gilvusmycin exhibited antitumor activity against murine leukemia P388 in vivo.

Combined therapy with radiofrequency thermal ablation and intra-arterial infusion chemotherapy for hepatic metastases from colorectal cancer

BACKGROUND/AIMS

In this preliminary study, we investigated the efficacy of combined radiofrequency thermal ablation therapy (RFA) with hepatic arterial infusion chemotherapy (HAI) in the treatment of multiple liver metastases from colorectal cancer.

METHODOLOGY

Nine patients with bilobular multiple metastases was treated. The number of nodules was 6.0 +/- 3.9 (range: 2-13), and the size was 2.1 +/- 1.0 cm (range: 0.5-4.8 cm) in diameter. RFA was performed using a RF generator operating at 460 kHz with a 15-gauge, 4-prong custom RF needle. Treatment temperature was kept at 90-110 degrees C for 5 min. 5-Fluorouracil (5-FU) was administered by weekly 750-1250 mg/body/5 h as the regimen of HAI.

RESULTS

During a 15.2-month follow-up period, 6 of 9 patients survived more than 1 year. Three of the 6 survived more than 2 years. Serum CEA level in 5 patients dropped from 24.5 +/- 9.5 ng/ml to 10.3 +/- 5.5 ng/ml. Local recurrence was observed in 5 patients and new lesions in 4. Extrahepatic recurrence was observed in 5 patients. There were no serious complications but one HAI-related cerebral thrombosis.

CONCLUSIONS

Combined RFA with HAI would be effective and safe. This modality provides a new option for the treatment of multiple liver metastases from colorectal cancer.

A mouse carrying genetic defect in the choice between T and B lymphocytes

Transgenic mice with human CD3epsilon gene have been shown to exhibit early arrest of T cell development in the thymus. The present study shows that, instead of T cells, B cells are generated in the thymus of a line, tg epsilon26, of the human CD3epsilon transgenic mice. The accumulation of mature B cells in the thymus was found only in tg epsilon26 mice, not in other human CD3epsilon transgenic mouse lines or other T cell-deficient mice, including CD3-epsilon knockout mice and TCR-beta/TCR-delta double knockout mice. Hanging drop-mediated transfer into 2-deoxyguanosine-treated thymus lobes showed that lymphoid progenitor cells rather than thymus stromal cells were responsible for abnormal B cell development in tg epsilon26 thymus, and that tg epsilon26 fetal liver cells were destined to become B cells in normal thymus even in the presence of normal progenitor cells undergoing T cell development. These results indicate that lymphoid progenitor cells in tg epsilon26 mice are genetically defective in thymic choice between T cells and B cells, generating B cells even in normal thymus environment. Interestingly, tg epsilon26 thymocytes expressed GATA-3 and TCF-1, but not LEF-1 and PEBP-2alpha, among T cell-specific transcription factors that are involved in early T cell development, indicating that GATA-3 and TCF-1 expressed during thymocyte development do not necessarily determine the cell fate into T cell lineage. Thus, tg epsilon26 mice provide a novel mouse model in that lineage choice between T and B lymphocytes is genetically defective.