RESUMEN
BACKGROUND: Mantle cell lymphoma (MCL) of the gastrointestinal tract is a rare malignancy, accounting for about 0.2% of malignant colorectal tumors. MCL synchronous with rectal adenocarcinoma is extremely rare. We know of only a few cases reported in the literature. We describe the case of a patient with synchronous rectal adenocarcinoma and intestinal MCL. CASE SUMMARY: A 63-year-old man was admitted to our hospital due to abdominal pain and hematochezia over the past month. The patient was diagnosed with middle rectal cancer cT2N0M0 and underwent surgery. However, we found a large tumor in the small intestine during surgery. The patient underwent total mesorectal excision for rectal cancer and resectioning of the ileal segment containing the large mass. Pathology and immunohistochemistry revealed the presence of both rectal adenocarcinoma and pathognomonic MCL stage IIE presenting as multiple lymphomatous polyposis. The patient subsequently underwent RDHAP/RCHOP chemotherapy and was maintained with rituximab. A Positron Emission Tomography and Computed Tomography (PET/CT) scan showed that the disease responded well to treatment without tumor-increased metabolism in the gastrointestinal tract. CONCLUSION: Synchronous rectal adenocarcinoma and intestinal MCL presenting as multiple lymphomatous polyposis are extremely rare. MCL is often discovered fortuitously when rectal cancer is diagnosed. The coexistence of these tumors poses treatment challenges.
RESUMEN
A new benzofuran derivative, nervione (1), was isolated from Nervilia concolor (Blume) Schltr. (Orchidaceae). Eight previously reported compounds were also isolated: 5,7-dimethoxyflavone (2), 3,5,7-trimethoxyflavone (3), 7-methoxyflavone (4), 3,7-dimethoxy-5-hydroxyflavone (5), tetramethylscutellarein (4',5,6,7-tetramethoxyflavone) (6), 5,7-dimethoxy-4'-hydroxyflavone (7), rhamnetin (8), and 5,7-dihydroxy-3',4'-dimethoxyflavone (9). The structures were elucidated by 1D, 2D NMR, and HRESIMS spectroscopy in addition to the literature. The relative configuration of 1 was defined using DP4+ probability while its absolute configuration was defined by comparison of the ECD spectrum of 1 with those of previously reported compounds. All isolated compounds were evaluated for alpha-glucosidase inhibition, revealing weak or no activity.[Formula: see text].
Asunto(s)
Benzofuranos , Orchidaceae , Espectroscopía de Resonancia Magnética , Estructura Molecular , Orchidaceae/química , alfa-GlucosidasasRESUMEN
L-Aspartic acid has recently been found to be a good leaving group during HIV reverse transcriptase catalyzed incorporation of deoxyadenosine monophosphate (dAMP) in DNA. This showed that L-Asp is a good mimic for the pyrophosphate moiety of deoxyadenosine triphosphate. The present work explores the thermochemistry and mechanism for hydrolysis of several models for L-aspartic-dAMP using B3LYP/DGDZVP, MP2/6-311++G** and G3MP2 level of theory. The effect of the new compound is gradually investigated: starting from a simple methyl amine leaving group up to the aspartic acid leaving group. The enzymatic environment was mimicked by involving two Mg(2+) ions and some important active site residues in the reaction. All reactions are compared to the corresponding O-coupled leaving group, which is methanol for methyl amine and malic acid for aspartic acid. With methyl amine as a leaving group a tautomeric associative or tautomeric dissociative mechanism is preferred and the barrier is lower than the comparable mechanism with methanol as a leaving group. The calculations on the aspartic acid in the enzymatic environment show that qualitatively the mechanism is the same as for triphosphate but the barrier for hydrolysis by the associative mechanism is higher for L-aspartic-dAMP than for L-malic-dAMP and pyrophosphate.