A nitronyl nitroxide complex of nickel(II) with nitrate as a ligand.

The complex cation in [4,5-dihydro-4,4,5,5-tetramethyl-2-(2-pyridyl-kappa N)imidazol-1-oxyl 3-oxide-kappa O(3)](nitrato-kappa(2)O,O')(N,N,N',N'-tetramethyl-1,2-ethanediamine-kappa(2)N,N')nickel(II) hexafluorophosphate dichloromethane solvate, [Ni(NO(3))(C(6)H(16)N(2))(C(12)H(16)N(3)O(2))]PF(6) x CH(2)Cl(2), is the first example of a nitronyl nitroxide complex of a transition metal ion having d electrons in which nitrate is coordinated as a bidentate ligand. Owing to the smaller steric requirement of NO(3)(-), the Ni-O(nitroxide) bond length [2.014 (2) A] is remarkably shorter than that in the corresponding beta-diketonate complexes [2.052 (4)-2.056 (2) A].

Direct observation of light induced spin transitions in new 3,5-bis(2-pyridyl)pyrazolato bridged thiocyanato diiron(II) complexes by monitoring variable temperature laser Raman spectra.

The light induced excited spin state trapping LIESST and the reverse LIESST-like phenomena are observed below and above the spin transition temperature, respectively, for new dinuclear diiron(II) complexes and familiar Fe(II) complexes with thiocyanate ligands by monitoring the Raman spectra where only excitation light of various wavelengths for the spectroscopy was used without extra excitation light sources.

Anomalous stereochemistry of pyrazolato-3,5-dicarboxylato-bridged dinuclear chromate(III) complexes containing ethylenediamine-N,N'-dicarboxylates with entrapped unstable conformations: X-ray structure of Na[Cr2(eddp)(mu-pzdc)].6H2O.

Several new pyrazolato-3,5-dicarboxylato (pzdc) bridged dinuclear chromate(III) complexes containing linear tetradentate O-N-N-O type ligands were synthesized and structurally characterized. Among them, the X-ray structure of the eddp complex Na[Cr2(eddp)(mu-pzdc)].6H2O (eddp = ethylenediamine-N,N'-dipropionate) was determined to have a (sym-cis)-(unsym-cis) geometrical configuration with intramolecular three-center hydrogen bonds, entrapping the unfavored sym-cis configuration for the Cr(eddp) moiety as well as the favored unsym-cis one. As a pair of positional disorders, there were also found to be two conformational isomers with respect to the absolute configurations of the coordinated asymmetric nitrogen atom at the G (in-plane) ring for the unsym-cis moiety. Moreover, chiral pzdc-bridged dinuclear complexes with another type of O-N-N-O ligand, 1,2-cyclohexanediamine-N,N'-diacetate (cdda), were successfully synthesized, isolated, and characterized by column chromatographic behavior, elemental analysis, and chiroptical spectra. There were two diastereomers for Na[(R,R-cdda)Cr(mu-pzdc)Cr(S,S-cdda)] and only one isomer for Na[(R,R-cdda)Cr(mu-pzdc)Cr(R,S-cdda)] and Na[(R,R-cdda)Cr(mu-pzdc)Cr(edda)] (R,R- or S,S- and R,S-cdda = R,R-trans- or S,S-trans- and R,S-cis-1,2-cyclohexanediamine-N,N'-diacetate, and edda = ethylenediamine-N,N'-diacetate). From their circular dichroism (CD) spectra, these complexes could exhibit the delta-delta absolute configuration with ((sym-cis-R,R-cdda)-(unsym-cis-edda or S,S- or R,S-cdda)) geometrical configuration, indicating the abnormal eq-eq (N-Ceq) configuration for the R,R-cdda. The comparison among the CD spectra of the ((cdda)-(cdda)) complexes revealed that two diastereomers of the ((R,R-cdda)-(S,S-cdda)) complex correspond to the conformational isomers resulting from the difference in geometrical orientations of the secondary amine protons on two coordinated asymmetric nitrogen atoms with the opposite absolute configuration in the unsym-cis-S,S-cdda moiety. In a series of the pzdc-bridged Cr(III) complexes the anomalous conformations in two different geometrical configurations could be entrapped probably owing to stereognostic coordination through the intramolecular N-H...O hydrogen bond interaction.

Preliminary report on local resection with lymphadenectomy for early gastric cancer.

BACKGROUND: The frequency of lymph node metastasis in mucosal gastric cancers 2-4 cm in diameter was low (three (1.3 per cent) of 234) in patients treated in this unit between 1966 and 1995. This study was a prospective report on local resection with lymphadenectomy for early gastric cancer. METHODS: Eight patients with a single early gastric cancer underwent local resection with lymphadenectomy. The tumour was excised with a non-cancerous rim of approximately 2 cm. The extent of lymphadenectomy depended on tumour location. Intraoperative endoscopic examination and frozen-section analysis of the dissected nodes were used to determine the resection line and evaluate nodal status. RESULTS: Mean operating time, blood loss and number of dissected nodes were 171 min, 87 ml and 8 respectively. There were no operative complications. Cancer invasion was confined to the mucosa in six tumours but two patients had minute submucosal invasion. The maximum diameter of the resected specimens was 10 cm and no nodal involvement was detected. No patient developed postgastrectomy syndrome. CONCLUSION: For selected patients with early gastric cancer, local resection with lymphadenectomy can provide a good quality of life without compromising cure rate.

Complete dissection of the lymph nodes located along and at the roots of the left gastroepiploic vessels during distal gastrectomy.

Achieving complete dissection of the lymph nodes located at the roots of the left gastroepiploic vessels is difficult when distal gastrectomy is the surgical goal; firstly, because the short gastric vessels must be preserved to supply blood to the remnant stomach; and also, because the roots of the left gastroepiploic vessels at the splenic hilus are obscured intraoperatively by adipose tissues. We describe herein a technique which enables complete and easy dissection of the lymph nodes located along and at the roots of the left gastroepiploic vessels.

Inhibitory effects of n-3 polyunsaturated fatty acids on sigmoid colon cancer transformants.

Various types of polyunsaturated fatty acids (PUFAs) have been suggested to exert different effects on the colon in terms of promotion or inhibition of tumor development. Results of in vitro and in vivo studies are, however, inconsistent and it remains unclear whether or not the cellular effects of PUFAs change along with the malignant transformation of colonic cells. In this study, we used the NIH3T3 cell line and its SIC (sigmoid colon cancer) oncogene transformants to compare the effects of PUFAs on the proliferation of non-malignant and malignant cells. We also determined the cellular utilization of fatty acids in media by a high-performance liquid chromatography method. The addition of exogenous arachidonic acid (ARA, an n-6 fatty acid), eicosapentaenoic acid (EPA, n-3), and docosahexaenoic acid (DHA, n-3) exerted different effects on NIH3T3 cells, and on SIC transformants, in which selective inhibitory effects were observed at media concentrations ranging from 10 to 20 microg/ml. In cells cultured in media supplemented with EPA or DHA at a concentration of 2 microg/ml, which had no effect on cell proliferation, the cellular utilization of linoleic acid (n-6), a precursor of n-3 fatty acids, was inhibited. This inhibition was stronger in SIC transformants than in NIH3T3 cells (P < 0.05). There was no difference in the utilization of fatty acids between the two cell lines cultured in media supplemented with ARA. We conclude that the cellular response to exogenous long-chain PUFAs is modified during the course of malignant transformation, and that EPA and DHA (n-3 PUFAs) appear to have specific inhibitory effects on cancer cells and may thus enhance the host defense against colon cancer.

Microvascular anastomosis for additional blood flow in reconstruction after intrathoracic esophageal carcinoma surgery.

Microvascular anastomosis, designed to achieve additional blood flow to the reconstructed site, was carried out in nine patients with intrathoracic esophageal cancer. This procedure prevents the major complications of esophagogastric and esophagocolic anastomotic leaks after subtotal esophagectomy.

The relationship of macroscopic shape of superficial esophageal carcinoma to depth of invasion and regional lymph node metastasis.

BACKGROUND: There has been considerable controversy with regard to surgical strategies for the treatment of superficial esophageal carcinoma, which is characterized by tumor confined within the epithelium (EP), muscularis mucosae (MM), or submucosa (SM). The relationships among macroscopic shape, depth of invasion, and lymph node involvement in superficial tumors were investigated to devise therapeutic strategies for patients with such disease. METHODS: Thirty-three patients with superficial primary esophageal cancer underwent esophagectomy with regional lymph node dissection (3 EP, 6 MM, and 24 SM). Tumors were divided into two types according to macroscopic characteristics: (1) tumors with elevated components and (2) flat or depressed tumors without an elevated component. RESULTS: Tumors with an elevated component (n = 19) showed invasion of the deep layer, and a high incidence of lymph node metastasis. Conversely, tumors without an elevated component (n = 14) showed varied depths of invasion, and, with one exception, had no lymph node involvement. CONCLUSIONS: The existence of an elevated component in superficial esophageal cancer is an important macroscopic feature suggesting submucosal invasion and a high probability of lymph node involvement. More intensive treatment should be adopted for such tumors, whereas localized resection may be feasible for tumors without an elevated component.