Structure and Unprecedented Reactivity of a Mononuclear Nonheme Cobalt(III) Iodosylbenzene Complex.

A mononuclear nonheme cobalt(III) iodosylbenzene complex, [CoIII (TQA)(OIPh)(OH)]2+ (1), is synthesized and characterized structurally and spectroscopically. While 1 is a sluggish oxidant in oxidation reactions, it becomes a competent oxidant in oxygen atom transfer reactions, such as olefin epoxidation, in the presence of a small amount of proton. More interestingly, 1 shows a nucleophilic reactivity in aldehyde deformylation reaction, demonstrating that 1 has an amphoteric reactivity. Another interesting observation is that 1 can be used as an oxygen atom donor in the generation of high-valent metal-oxo complexes. To our knowledge, we present the first crystal structure of a CoIII iodosylbenzene complex and the unprecedented reactivity of metal-iodosylarene adduct.

Cytological findings of NK/T-cell lymphoma in pericardial effusion: A case report with a review of the literature.

Extranodal Natural Killer/T-cell lymphoma (ENKL) is an aggressive NK or cytotoxic T-cell neoplasm. The cytological features of NK/T-cell lymphoma have been rarely described, mainly focusing on the fine needle aspiration cytology from lymph nodes or soft tissue, except for a few cases focused on body fluid. A 46-year-old man visited the hospital due to generalized weakness and weight loss. Three months prior, computed tomographic scan revealed mesenteric panniculitis and reactive lymph nodal enlargement, as well as a mildly thickened left adrenal gland, suggesting an inflammatory condition. About 100 days later, marked enlargement of both adrenal glands with pericardial effusion was noted. The pericardial effusion contained medium-sized atypical lymphocytes, suspicious for malignant lymphoma, and the left adrenal mass was histologically confirmed as ENKL on biopsied specimen. Herein, we describe the cytological features of NK/T-cell lymphoma in body fluid cytology along with a review of the literature.

Unified Mechanism of Oxygen Atom Transfer and Hydrogen Atom Transfer Reactions with a Triflic Acid-Bound Nonheme Manganese(IV)-Oxo Complex via Outer-Sphere Electron Transfer.

Outer-sphere electron transfer from styrene, thioanisole, and toluene derivatives to a triflic acid (HOTf)-bound nonheme Mn(IV)-oxo complex, [(N4Py)MnIV(O)]2+-(HOTf)2 (N4Py = N, N-bis(2-pyridylmethyl)- N-bis(2-pyridyl)methylamine), has been shown to be the rate-determining step of different types of redox reactions such as epoxidation, sulfoxidation, and hydroxylation of styrene, thioanisole, and toluene derivatives, respectively, by [(N4Py)MnIV(O)]2+-(HOTf)2. The rate constants of HOTf-promoted epoxidation of all styrene derivatives with [(N4Py)MnIV(O)]2+ and electron transfer from electron donors to [(N4Py)MnV(O)]2+ exhibit a remarkably unified correlation with the driving force of outer-sphere electron transfer in light of the Marcus theory of electron transfer. The same electron-transfer driving force dependence is observed in the oxygen atom transfer from [(N4Py)MnIV(O)]2+-(HOTf)2 to thioanisole derivatives as well as in the hydrogen atom transfer from toluene derivatives to [(N4Py)MnIV(O)]2+-(HOTf)2. Thus, mechanisms of oxygen atom transfer (epoxidation and sulfoxidation) reactions of styrene and thioanisole derivatives and hydrogen atom transfer (hydroxylation) reactions of toluene derivatives by [(N4Py)MnIV(O)]2+-(HOTf)2 have been unified for the first time as the same reaction pathway via outer-sphere electron transfer, followed by the fast bond-forming step, which exhibits the singly unified electron-transfer driving force dependence of the rate constants as outer-sphere electron-transfer reactions. In the case of the epoxidation of cis-stilbene by [(N4Py)MnIV(O)]2+-(HOTf)2, the isomerization of cis-stilbene radical cation to trans-stilbene radical cation occurs after outer-sphere electron transfer from cis-stilbene to [(N4Py)MnIV(O)]2+-(HOTf)2 to yield trans-stilbene oxide selectively, which is also taken as evidence for the occurrence of electron transfer in the acid-catalyzed epoxidation.

Appendicitis during Pregnancy: The Clinical Experience of a Secondary Hospital.

PURPOSE: Appendicitis is the most common condition leading to an intra-abdominal operation for a non-obstetric problem in pregnancy. The aim of this study was to examine our experience and to analyze the clinical characteristics and the pregnancy outcomes for appendicitis during pregnancy that was reported in Korea. METHODS: We reported 25 cases of appendicitis during pregnancy that were treated at Good Moonhwa Hospital from January 2004 to March 2010. We also analyzed appendicitis during pregnancy reported in Korea between 1970 and 2008 by a review of journals. RESULTS: The incidence of acute appendicitis during pregnancy was one per 568 deliveries. The mean age was 27.92 years old, the gestational stage at the onset of symptoms was the first trimester in 10 patients (40%), the second trimester in 14 patients (56%), and the third trimester in 1 patient (4%). Among the 25 cases, 21 were treated with an open appendectomy and 4 with laparoscopic appendectomies. The postoperative complications were 2 wound infections and 1 spontaneous abortion. CONCLUSION: Our experience demonstrated that appendectomies on pregnant patients can be successfully performed at secondary hospitals.

Preliminary X-ray crystallographic analysis of the breakage-reunion domain of the GyrA subunit of DNA gyrase from Colwellia psychrerythraea strain 34H.

DNA gyrase is a type II topoisomerase that is essential for chromosome segregation and cell division owing to its ability to modify the topological forms of bacterial DNA. In this study, the N-terminal breakage-reunion domain of the GyrA subunit of DNA gyrase from Colwellia psychrerythraea 34H was overexpressed in Escherichia coli, purified and crystallized. Diffraction data were collected to 2.60 A resolution using a synchrotron-radiation source. The crystal belonged to space group P2(1)2(1)2(1), with unit-cell parameters a = 98.98, b = 101.56, c = 141.83 A. The asymmetric unit contained two molecules, with a corresponding V(M) of 3.18 A(3) Da(-1) and a solvent content of 59.9%.

Crystallization and preliminary X-ray crystallographic analysis of DNA gyrase GyrB subunit from Xanthomonas oryzae pv. oryzae.

DNA gyrase is a type II topoisomerase that is essential for chromosome segregation and cell division owing to its ability to modify the topological forms of bacterial DNA. In this study, the N-terminal fragment of the GyrB subunit of DNA gyrase from Xanthomonas oryzae pv. oryzae was overexpressed in Escherichia coli, purified and crystallized. Diffraction data were collected to 2.10 A resolution using a synchrotron-radiation source. The crystal belonged to space group I4(1), with unit-cell parameters a = b = 110.27, c = 70.75 A. The asymmetric unit contained one molecule, with a V(M) of 2.57 A(3) Da(-1) and a solvent content of 50.2%.

Treatment outcome of adult patients with Burkitt lymphoma: results using the LMB protocol in Korea.

Burkitt lymphoma (BL) is a rare subtype of adult non-Hodgkin lymphoma, so studies on the outcome of adult BL, especially in Asian patients, are scarce. We report our results using the LMB protocol on Korean adult BL patients. Thirty-eight newly diagnosed BL patients were treated with the LMB protocol; 29 males and nine females with a median age of 47 years (range 18-70) were analyzed, and 14 (36.8%) patients had central nervous system or bone marrow involvement. After the induction phase, 28 patients achieved complete response (CR, 73.7%) and five showed partial response (PR, 13.2%). Among those achieving CR, only four showed relapse. All of the non-CR patients died, including five PR and one with progressive disease. The other four patients died because of infection after the first course of induction. The progression-free and overall estimated survival at 5 years was 74.99% and 68.10%, respectively. Of the 12 patients who died, the median survival was 4.43 months (95% confidence interval 1.43-7.43 months). Thus, most deaths occurred shortly after diagnosis, and four patients older than 58 years died after the first induction cycle. Most early deaths were caused by treatment-related morbidity and failure to achieve complete response. B symptoms, advanced age, bone marrow involvement, and St. Jude/Murphy stage IV classification were significantly associated with poor overall survival. In conclusion, the LMB protocol was effective for Korean adult BL patients. However, considering the high incidence of treatment-related deaths and the poor outcome of non-CR patients, risk-adapted modification of the induction phase is warranted.

Phase II study of docetaxel and cisplatin as first-line chemotherapy in patients with recurrent or metastatic gastric cancer.

PURPOSE: Palliative chemotherapy for patients with recurrent or metastatic gastric cancer has been shown to have a survival benefit. Docetaxel monotherapy has achieved appreciable results for treating gastric cancer. We investigated the clinical efficacy and feasibility of a docetaxel and cisplatin combination regimen for patients suffering with recurrent or metastatic gastric cancer. MATERIALS AND METHODS: Patients with histologically proven, bidimensionally measurable lesions of recurrent or metastatic gastric cancer, and they had an Eastern Cooperative Oncology Group (ECOG) performance status of 0 to 2 and no prior palliative chemotherapy were eligible for this study. The combination chemotherapy regimen consisted of docetaxel 75 mg/m(2) plus cisplatin 75 mg/m(2) on day 1, and this was repeated every 3 weeks until disease progression. RESULTS: 32 patients were enrolled from 2002 to 2005. The objective response rate was 31.3% (95% confidence interval (CI): 14.2 approximately 48.2%) with no CR. The disease control rate was 59.4%. At a median follow up of 38.9 months, the median overall survival was 7.4 months (95% CI: 6.3 approximately 8.5). The median time to progression was 4.7 months (95% CI: 3.1 approximately 6.3). During a total of 106 cycles, grade 3 or 4 hematological toxicities were observed as follows: neutropenia (39 of 106 cycles) and anemia (3 of 106 cycles). The grade 3 or 4 non-hematological toxicities included anorexia (18.9%) and nausea/vomiting (21.7%). CONCLUSION: Docetaxel and cisplatin combination chemotherapy showed promising anti-tumor activity and this was well tolerated as a first-line treatment for patients with recurrent or metastatic gastric cancer. Further large, randomized phase III studies are warranted.

Expression of angiogenic factor Cyr61 during neuronal cell death via the activation of c-Jun N-terminal kinase and serum response factor.

The immediate early gene, cyr61, is transcriptionally activated within minutes by serum and serum growth factors. The encoded Cyr61 protein is secreted into the extracellular matrix and promotes cell adhesion and migration. In this study, we sought to examine the expression profile of cyr61 gene during neuronal cell death induced by various toxic stimuli and the mechanisms involved. Our data show that toxic stimuli, such as etoposide, significantly increased cyr61 mRNA levels in immortalized hippocampal progenitor (H19-7) cells. Cyr61 transcriptional activation was corroborated at the protein level as well. To identify the upstream signaling cascades involved in cyr61 gene induction, the blocking effect of either JNK or p38 kinase-signaling pathway on cyr61 induction in response to etoposide was tested. Transfection of the cells with a kinase-deficient mutant MEKK, an upstream activator of JNK, significantly decreased the cyr61 expression induced by etoposide. In contrast, cyr61 mRNA levels did not change after pretreatment with SB203580, the p38 kinase inhibitor. When the induction of cyr61 was tested by using several of its deleted promoters driving the expression of reporter gene, the promoter activation occurred primarily within the region containing an SRE-like CArG box. In addition, the SRF, which binds to the CArG site, was directly phosphorylated by active JNK. Furthermore, the blockade of cyr61 gene expression using an antisense encoding cyr61 sequence significantly inhibited the cell death induced by etoposide. Overall, these results suggest that the induction of the immediate early gene, cyr61, is important for neuronal cell death in the central nervous system hippocampal progenitor cells, and JNK activation, but not of p38, as well as the subsequent SRF phosphorylation are involved in cyr61 gene induction.