31 research outputs found
Laparoscopic total colectomy with lymph node dissection for familial adenomatous polyposis with multiple colorectal cancers
A 49-year-old Japanese man visited our hospital with chief complaints of difficulty with and bleeding during defecation. After a detailed examination, he was diagnosed with familial adenomatous polyposis (FAP) with multiple (five) colorectal cancers. The tumors were located in the right-sided, left-sided, and sigmoid colon, and the lower rectum. Regional lymph node involvement was observed, but no metastasis to other organs was detected. We, therefore, performed a laparoscopic total colectomy with superior mesenteric artery (SMA) and inferior mesenteric artery (IMA) lymph node dissection. We were able to perform minimally invasive and cosmetically acceptable surgery using laparoscopy instead of highly-invasive open abdominal surgery. Our search of the literature revealed no reported cases of laparoscopic total colectomy with lymph node dissection for FAP with multiple colorectal cancers, making the present case the first to be reported in the literature
A case of asymptomatic right-sided adult Bochdalek hernia presented incidentally with rectal tumor
We encountered a patient with an adult Bochdalek hernia discovered asymptomatically. A 77-year-old Japanese woman visited a local clinic with chief complaints of melena and difficulty in defecation. Based on the results of the detailed examination in our hospital, she was diagnosed with a rectal gastrointestinal stromal tumor (GIST) with a concurrent asymptomatic adult right-sided Bochdalek hernia. Because the tumor was large, laparoscopic abdominoperineal rectal amputation was performed after systemic imatinib therapy. During the surgery, we found a right diaphragmatic defect more than 13cm in long dia., through which the right hepatic lobe, colon, and greater omentum had prolapsed into the right thoracic cavity. No visceral adhesions were noted. No hernia sac was observed. Adult Bochdalek hernia is a relatively rare condition, and only three (incidentally discovered) cases of asymptomatic Bochdalek hernia, including the present case, have been reported in Japan. Here we provide a case report for the patient, who was followed-up without hernia surgery, plus a review of the literature
A case of laparoscopic and endoscopic cooperative surgery for sigmoidovesical fistula
We performed laparoscopic and endoscopic cooperative surgery (LECS) for partial colectomy with partial cystectomy in an 80-year-old woman with sigmoidovesical fistula secondary to sigmoid diverticulitis. LECS was designed for local resection of the stomach for gastric submucosal tumors using the endoscopic submucosal dissection (ESD) technique. While conventional open abdominal surgery is very invasive, LECS has enabled surgeons to perform minimally invasive surgery. Although there have been no reported cases in which the bladder was laparoscopically resected after sigmoidovesical fistula division, we were able to safely resect the fistula and preserve the urethral opening by performing laparoscopic and cystoscopic cooperative surgery. There are no previously reported cases in which LECS was performed for partial sigmoidectomy and partial cystectomy ; therefore, we report this as a valuable case, with a review of the literature. We hope that further studies involving more patients will lead to the establishment of this procedure
Enhanced Oxidative DNA Cleavage Activity of Iron Complex of Pentadentate Mono-carboxamide Ligand Having Spermine as DNA Binding Domain
Detection of Enzymatically Generated Hydrogen Peroxide by Metal-Based Fluorescent Probe
We developed a metal-based fluorescent probe for H<sub>2</sub>O<sub>2</sub> called MBFh1, which has an iron complex as a reaction site for H<sub>2</sub>O<sub>2</sub> and a 3,7-dihydroxyphenoxazine derivative as the fluorescent reporter unit. The iron complex reacts quickly with H<sub>2</sub>O<sub>2</sub> to form oxidants, and then the oxidants convert the closely appended nonfluorescent 3,7-dihydroxyphenoxazine moiety to resorufin in an intramolecular fashion. The quick response to H<sub>2</sub>O<sub>2</sub> allows us to plot the enzymatic evolution of H<sub>2</sub>O<sub>2</sub>. A combination of <i>N</i>-acetyl-3,7-dihydroxyphenoxazine and horseradish peroxidase has been frequently used to detect enzymatically generated H<sub>2</sub>O<sub>2</sub>, but this method has interference with phenol derivatives. The use of MBFh1 overcomes this drawback
Fast Guest Exchange of a 1:1 Zinc Porphyrin-Amine Host-Guest Complex via a Six-Coordinated Zinc Porphyrin
Catalytic Performance of a Dicopper–Oxo Complex for Methane Hydroxylation
A dicopper(II) complex,
[Cu<sub>2</sub>(μ-OH)(6-hpa)]<sup>3+</sup>, where 6-hpa is 1,2-bis[2-[bis(2-pyridylmethyl)aminomethyl]-6-pyridyl]ethane,
generates an oxyl radical of Cu<sup>II</sup>O<sup>•</sup> and
catalyzes the selective hydroxylation of benzene to phenol. From the
structural similarity to methane activation catalysts (e.g., bare
CuO<sup>+</sup> ion, Cu-ZSM-5, and particulate methane monooxygenase),
it is expected to catalyze methane hydroxylation. The catalytic performance
for the hydroxylation of methane to methanol by this dicopper complex
is investigated by using density functional theory (DFT) calculations.
The whole reaction of the methane conversion involves two steps without
radical species: (1) C–H bond dissociation of methane by the
Cu<sup>II</sup>O<sup>•</sup> moiety and (2) C–O bond
formation with methyl migration. In the first step, the activation
barrier is calculated to be 10.2 kcal/mol, which is low enough for
reactions taking place under normal conditions. The activation barrier
by the other Cu<sup>II</sup>O<sub>2</sub><sup>•</sup> moiety
is higher than that by the Cu<sup>II</sup>O<sup>•</sup> moiety,
which should work to turn the next catalytic cycle. DFT calculations
show that the dicopper complex has a precondition to hydroxylate methane
to methanol. Experimental verification is required to look in detail
at the reactivity of this dicopper complex
Electrochemical Epoxidation Catalyzed by Manganese Salen Complex and Carbonate with Boron-Doped Diamond Electrode
Epoxides are essential precursors for epoxy resins and other chemical products. In this study, we investigated whether electrochemically oxidizing carbonate ions could produce percarbonate to promote an epoxidation reaction in the presence of appropriate metal catalysts, although Tanaka and co-workers had already completed a separate study in which the electrochemical oxidation of chloride ions was used to produce hypochlorite ions for electrochemical epoxidation. We found that epoxides could be obtained from styrene derivatives in the presence of metal complexes, including manganese(III) and oxidovanadium(IV) porphyrin complexes and manganese salen complexes, using a boron-doped diamond as the anode. After considering various complexes as potential catalysts, we found that manganese salen complexes showed better performance in terms of epoxide yield. Furthermore, the substituent effect of the manganese salen complex was also investigated, and it was found that the highest epoxide yields were obtained when Jacobsen’s catalyst was used. Although there is still room for improving the yields, this study has shown that the in situ electrochemical generation of percarbonate ions is a promising method for the electrochemical epoxidation of alkenes
KCTD19 and its associated protein ZFP541 are independently essential for meiosis in male mice.
Meiosis is a cell division process with complex chromosome events where various molecules must work in tandem. To find meiosis-related genes, we screened evolutionarily conserved and reproductive tract-enriched genes using the CRISPR/Cas9 system and identified potassium channel tetramerization domain containing 19 (Kctd19) as an essential factor for meiosis. In prophase I, Kctd19 deficiency did not affect synapsis or the DNA damage response, and chiasma structures were also observed in metaphase I spermatocytes of Kctd19 KO mice. However, spermatocytes underwent apoptotic elimination during the metaphase-anaphase transition. We were able to rescue the Kctd19 KO phenotype with an epitope-tagged Kctd19 transgene. By immunoprecipitation-mass spectrometry, we confirmed the association of KCTD19 with zinc finger protein 541 (ZFP541) and histone deacetylase 1 (HDAC1). Phenotyping of Zfp541 KO spermatocytes demonstrated XY chromosome asynapsis and recurrent DNA damage in the late pachytene stage, leading to apoptosis. In summary, our study reveals that KCTD19 associates with ZFP541 and HDAC1, and that both KCTD19 and ZFP541 are essential for meiosis in male mice