Endoscopic drainage with a metallic stent for obstructive jaundice caused by bile duct metastasis of breast cancer: A case report.

Key Clinical Message: Bile duct metastasis of breast cancer is rare. It often causes obstructive jaundice which makes the patient interrupt state of treatment. Endoscopic drainage for obstructive jaundice is effective and less invasive treatment option also in this case. Abstract: A 66-year-old breast ductal carcinoma patient developed obstructive jaundice, presenting with epigastric discomfort and dark-colored urine. Computed tomography and endoscopic retrograde cholangiopancreatography revealed bile duct stenosis. Brushing cytology and tissue biopsy confirmed bile duct metastasis, a self-expandable metallic stent was placed/replaced endoscopically, and chemotherapy was continued, extending the patient's life.

l-Tryptophan-starved cultivation enhances S-allyl-l-cysteine synthesis in various food-related microorganisms.

S-Allyl-l-cysteine (SAC) has received much interest due to its beneficial effects on human health. To satisfy the increasing demand for SAC, this study aims to develop a valuable culturing method for microbial screening synthesizing SAC from readily available materials. Although tryptophan synthase is a promising enzyme for SAC synthesis, its expression in microorganisms is strictly regulated by environmental l-tryptophan. Thus, we constructed a semisynthetic medium lacking l-tryptophan using casamino acids. This medium successfully enhanced the SAC-synthesizing activity of Lactococcus lactis ssp. cremoris NBRC 100676. In addition, microorganisms with high SAC-synthesizing activity were screened by the same medium. Food-related Klebsiella pneumoniae K-15 and Pantoea agglomerans P-3 were found to have a significantly increased SAC-synthesizing activity. The SAC-producing process established in this study is shorter in duration than the conventional garlic aging method. Furthermore, this study proposes a promising alternative strategy for producing food-grade SAC by microorganisms.

Structure of a [NiFe] hydrogenase maturation protease HycI provides insights into its substrate selectivity.

The immature large subunit of [NiFe] hydrogenases undergoes C-terminal cleavage by a specific protease in the final step of the post-translational process before assembly with other subunits. It has been reported that the [NiFe] hydrogenase maturation protease HycI from Thermococcus kodakarensis (TkHycI) has the catalytic ability to target the membrane-bound hydrogenase large subunit MbhL from T. kodakarensis. However, the detailed mechanism of its substrate recognition remains elusive. We determined the crystal structure of TkHycI at 1.59 Šresolution to clarify how TkHycI recognizes its own substrate MbhL. Although the overall structure of TkHycI is similar to that of its homologous protease TkHybD, TkHycI adopts a larger loop than TkHybD, thereby creating a broad and deep cleft. We analyzed the structural properties of the TkHycI cleft probably involved in its substrate recognition. Our findings provide novel and profound insights into the substrate selectivity of TkHycI.

Crystal structure of a [NiFe] hydrogenase maturation protease HybD from Thermococcus kodakarensis KOD1.

A [NiFe] hydrogenase maturation protease HybD from Thermococcus kodakarensis KOD1 (TkHybD) is involved in the cleavage of the C-terminal residues of [NiFe] hydrogenase large subunits by Ni recognition. Here, we report the crystal structure of TkHybD at 1.82 Å resolution to better understand this process. TkHybD exhibits an α/ß/α sandwich fold with conserved residues responsible for the Ni recognition. Comparisons of TkHybD with homologous proteins also reveal that they share a common overall architecture, suggesting that they have similar catalytic functions. Our results including metal binding site prediction provide insight into the substrate recognition and catalysis mechanism of TkHybD. Proteins 2016; 84:1321-1327. © 2016 Wiley Periodicals, Inc.

[A Case of Strangulation Ileus with Hemorrhagic Shock Caused by an Internal Hernia of the Small Intestine].

PATIENT: An 81-year-old man. Past medical history: distal gastrectomy and Roux-en-Y reconstruction. CHIEF COMPLAINT: epigastric pain, nausea, and hematemesis. History of present illness: the man developed epigastric pain, nausea, and hematemesis the day before visiting our hospital. Upper gastrointestinal endoscopy revealed that the small intestinal mucosa was extensively congested, and a clinical condition due to the previous gastric surgery was suspected. Therefore, the man was admitted to our department. The patient was diagnosed with strangulation ileus by contrast-enhanced abdominal CT, and was referred for emergency surgery. At the time of entering the operating room 3 hours later, his abdomen was remarkably swollen. After anesthesia induction, his blood pressure dropped to 40-49 mmHg, and he was in a state of shock. Strangulation ileus was caused by an internal hernia of the small intestine through the gap between the mesenteric sutures of the Roux-en-Y reconstruction. The small intestinal wall was significantly discolored and remarkably expanded due to bleeding into the small intestine. We determined that mass resection of the small intestine posed high risk, and performed only reduction of the small intestinal hernia. Since strangulated ileus causing hemorrhagic shock is rare, we describe the case and review the literature on the topic.

Enzymatic production of L-alanyl-L-glutamine by recombinant E. coli expressing α-amino acid ester acyltransferase from Sphingobacterium siyangensis.

An enzymatic production method for synthesizing L-alanyl-L-glutamine (Ala-Gln) from L-alanine methyl ester hydrochloride (AlaOMe) and L-glutamine (Gln) was developed in this study. The cultivation conditions for an Escherichia coli strain overexpressing α-amino acid ester acyltransferase from Sphingobacterium siyangensis AJ 2458 (SAET) and reaction conditions for Ala-Gln production were optimized. A high cell density culture broth prepared by fed-batch cultivation showed 440 units/mL of Ala-Gln-producing activity. In addition, an Ala-Gln-producing reaction using intact E. coli cells overexpressing SAET under optimum conditions was conducted. A total Ala-Gln yield of 69.7 g/L was produced in 40 min. The molar yield was 67% against both AlaOMe and Gln.