Electronic Structures of Metallocene Complexes. I. Electronic Structure of Metallocenes. Optical Spectroscopic Study of Metallocene Complexes. II. Magnetic Susceptibility Study of the Ferricenium Ion. III. Synthesis and Characterization of Several Oxidation Products of Ruthenocene

I. ELECTRONIC STRUCTURE OF METALLOCENES The electronic absorption spectra of various low-spin d5 and d6 metallocene complexes have been studied in different environments (glasses, KBr pellets, and single crystals) and as a function of temperature. Ferrocene, phenylferrocene, ruthenocene, and cobalticenium ion were selected in the d6 study and several ferricenium, n-butylferricenium, and 1,1' -di-n-butylferricenium salts were examined in the d5 case. The electronic spectra of ferrocene and phenylferrocene single crystals at 4.2°K clearly indicate that the bands at 22,700 cm-1 and 22,400 cm-1, respectively, consist of two electronic transitions each. The corresponding band systems in ruthenocene and cobalticenium ion also exhibit asymmetry at 77 °K. Ligand field theory has been successfully applied to the above d6 metallocenes, utilizing the three observed spin-allowed d-d absorption band positions. Emission of ruthenocene has been observed at 23,300 cm-1 and discussed in conjunction with the reported ferrocene emission. The visible absorption spectra of the various ferricenium complexes show a low-energy charge transfer transition (16,200 cm-1 in the unsubstituted ion). Ring substitution and temperature effects have been used to assign this band to the ligand-to-metal 2E2g → 2E1u transition. The vibrational structure observed for this band at 77°K appears as a doubled progression of the lowest energy a1g vibration. The doubling has been attributed to splitting of the 2E1u excited state. Detailed assignments of this vibrational structure are given for [Fe(cp)2]PF6 and [Fe(cp)2](CCl3CO2H)3. The intense charge transfer band of ferrocene(~ 50,000 cm-1), as well as the corresponding bands in the other d6 metallocenes, have been assigned as ligand-to-metal transitions. A similar assignment has been proposed for the three strong (f ≈ 0.1) bands observed in the ferricenium ultraviolet absorption spectrum. II. MAGNETIC SUSCEPTIBILITY STUDY OF THE FERRICENIUM ION The ground electronic state [2E2g(a1g)2(e2g)3] of the ferricenium ion has been further characterized by a variable-temperature (40-300°K) magnetic susceptibility study of nine ferricenium and two analogous Fe(III) dicarbollide (1,2-B9C2H112- state. Solvent and counter ion effects on the magnetic properties of the ferricenium ion are appreciable. III. SYNTHESIS AND CHARACTERIZATION OF SEVERAL OXIDATION PRODUCTS OF RUTHENOCENE Attempts to prepare ruthenicenium salts have resulted in the synthesis and characterization of several interesting ruthenocene derivatives. Contrary to a previous report, electrochemical oxidation of ruthenocene employing a mercury anode yields the mercury-bridged dimer [(cp)2Ru-Hg-Ru(cp)2](ClO4)2. Analytical, infrared, Raman, and electronic absorption spectral data were utilized in assigning the molecular structure. In particular, a Raman band at 110 cm-1 was assigned to the symmetrical Ru-Hg-Ru stretching mode. Preliminary X-ray crystallographic data for the hexafluorophosphate salt, which was obtained by anion exchange, are in agreement with the above dimeric formulation. Chemical oxidation of ruthenocene by iodine and bromine gives [Ru(cp)2I]I3 and [Ru(cp)2Br]Br3, respectively, as indicated by analytical and spectral data.</p

Incidentally Detected Situs Ambiguous in Adults

Situs ambiguous is rare congenital anomaly in adults. In 2 adult patients who admitted for different cardiac problems, situs ambiguous with polysplenia was detected. A 42-year-old male admitted for radio frequent catheter ablation of atrial fibrillation, and he had left-sided inferior vena cava (IVC), hepatic segment of IVC interruption with hemiazygos continuation, multiple spleens and intestinal malrotation. And in a 52-year-old female case who was hospitalized due to infective endocarditis after implanting pacemaker for sick sinus syndrome, multiple spleens, left-sided stomach, bilateral liver with midline gallbladder, and left-sided IVC were found. Those findings were consistent with situs ambiguous with polysplenia, but their features were distinctive

A study of the relationship between clinical phenotypes and plasma iduronate-2-sulfatase enzyme activities in Hunter syndrome patients

PurposeMucopolysaccharidosis type II (MPS II or Hunter syndrome) is a rare lysosomal storage disorder caused by iduronate-2-sulfatase (IDS) deficiency. MPS II causes a wide phenotypic spectrum of symptoms ranging from mild to severe. IDS activity, which is measured in leukocyte pellets or fibroblasts, was reported to be related to clinical phenotype by Sukegawa-Hayasaka et al. Measurement of residual plasma IDS activity using a fluorometric assay is simpler than conventional measurements using skin fibroblasts or peripheral blood mononuclear cells. This is the first study to describe the relationship between plasma IDS activity and clinical phenotype of MPS II.MethodsWe hypothesized that residual plasma IDS activity is related to clinical phenotype. We classified 43 Hunter syndrome patients as having attenuated or severe disease types based on clinical characteristics, especially intellectual and cognitive status. There were 27 patients with the severe type and 16 with the attenuated type. Plasma IDS activity was measured by a fluorometric enzyme assay using 4-methylumbelliferyl-α-iduronate 2-sulphate.ResultsPlasma IDS activity in patients with the severe type was significantly lower than that in patients with the attenuated type (P=0.006). The optimal cut-off value of plasma IDS activity for distinguishing the severe type from the attenuated type was 0.63 nmol·4 hr-1·mL-1. This value had 88.2% sensitivity, 65.4% specificity, and an area under receiver-operator characteristics (ROC) curve of 0.768 (ROC curve analysis; P=0.003).ConclusionThese results show that the mild phenotype may be related to residual lysosomal enzyme activity

Multi-Disciplinary Treatment of a Rare Pelvic Cavity Ependymoma

Ependymomas usually develop from neuroectodermal organs. Here, we present an ependymoma arising from the pelvic cavity. A 27-year-old Korean female was admitted to the hospital with a sensation of abdominal fullness. Imaging studies revealed a huge heterogeneous nodular mass in the pelvis and lower abdomen. Laparotomy showed that two large masses with multiple nodules were located between the uterus and rectum and uterus and bladder, respectively. Histologically, the tumor was characterized by compact columnar neoplastic cells divided by fibrovascular septae. The neoplastic cells formed true ependymal rosettes and perivascular pseudorosettes. Immunohistochemical staining showed a strong positive reaction for glial fibrillary acidic protein (GFAP) and vimentin and a partial positive reaction for S100 and EMA. The tumor was thus diagnosed as an ependymoma arising from the pelvic cavity. The patient was treated with a debulking operation and chemotherapy based upon the in vitro chemosensitivity test results. The patient was free of cancer for 4 years following surgery. This is a rare case of extraneural ependymoma for which an in vitro chemosensitivity test was critical in determining the multidisciplinary approach for treatment

Effect of Cosensitization with Buckwheat Flour Extract on the Production of House Dust Mite-specific IgE

There are studies reporting food sensitization in infancy increases the risk of sensitization to inhalants later in life. We performed a study to evaluate whether cosensitization with buckwheat (BW) has an effect on the production of house dust mite-IgE. C3H/HeJ mice (4 weeks, female) were sensitized with house dust mite (HDM)/Al (OH)3, intraperitoneally on day 0, followed by 4 intranasal sensitizations (on days 14, 15, 16, and 21). Group 1 was cosensitized intragastrically with BW/cholera toxin (CT) (on days 0, 1, 2, 7, and 18) during sensitization with HDM, group 2 was cosensitized intragastrically with CT only (on days 0, 1, 2, 7, and 18), and group 3 was used as controls. HDM- and BW-IgE and antigen-specific T-cell proliferation and cytokine production were evaluated. In Group 1, BW-IgE levels were highest at week 4, and the HDM-IgE at week 3 (98.45±64.37 ng/mL and 169.86±55.54 ng/mL, respectively). In Group 2, HDM-IgE levels reached a peak at week 3, remarkably higher (810.52±233.29 ng/mL) compared to those of Group 1 (169.86±55.54 ng/mL). The interleukin (IL)-4 and interferon (IFN)-γ in the HDM-stimulated culture supernatants of splenocytes were not significantly different among groups. We postulate that the cosensitization with BW may down-regulate the specific IgE response to HDM

Current Trends in the Epidemiological and Pathological Characteristics of Gastrointestinal Stromal Tumors in Korea, 2003-2004

Despite remarkable progress in understanding and treating gastrointestinal stromal tumors (GISTs) during the past two decades, the pathological characteristics of GISTs have not been made clear yet. Furthermore, concrete diagnostic criteria of malignant GISTs are still uncertain. We collected pathology reports of 1,227 GISTs from 38 hospitals in Korea between 2003 and 2004 and evaluated the efficacy of the NIH and AFIP classification schemes as well as the prognostic factors among pathologic findings. The incidence of GISTs in Korea is about 1.6 to 2.2 patients per 100,000. Extra-gastrointestinal GISTs (10.1%) are more common in Korea than in Western countries. In univariate analysis, gender, age, tumor location, size, mitosis, tumor necrosis, vascular and mucosal invasions, histologic type, CD34 and s-100 protein expression, and classifications by the NIH and AFIP criteria were found to be significantly correlated with patient's survival. However, the primary tumor location, stage and classification of the AFIP criteria were prognostically significant in predicting patient's survival in multivariate analysis. The GIST classification based on original tumor location, size, and mitosis is more efficient than the NIH criteria in predicting patient's survival, but the mechanism still needs to be clarified through future studies