Improvement of the nitrogenase activity in Escherichia coli that expresses the nitrogen fixation-related genes from Azotobacter vinelandii.

The transfer of nitrogen fixation (nif) genes from diazotrophs to non-diazotrophic hosts is of increasing interest for engineering biological nitrogen fixation. A recombinant Escherichia coli strain expressing Azotobacter vinelandii 18 nif genes (nifHDKBUSVQENXYWZMF, nifiscA, and nafU) were previously constructed and showed nitrogenase activity. In the present study, we constructed several E. coli strain derivatives in which all or some of the 18 nif genes were additionally integrated into the fliK locus of the chromosome in various combinations. E. coli derivatives with the chromosomal integration of nifiscA, nifU, and nifS, which are involved in the biosynthesis of the [4Fe-4S] cluster of dinitrogenase reductase, exhibited enhanced nitrogenase activity. We also revealed that overexpression of E. coli fldA and ydbK, which encode flavodoxin and flavodoxin-reducing enzyme, respectively, enhanced nitrogenase activity, likely by facilitating electron transfer to dinitrogenase reductase. The additional expression of nifM, putatively involved in maturation of dinitrogenase reductase, further enhanced nitrogenase activity and the amount of soluble NifH. By combining these factors, we successfully improved nitrogenase activity 10-fold.

Re-discovery of MS-347a as a fungicide candidate through a new drug discovery platform with a multidrug-sensitive Saccharomyces cerevisiae screening system and the introduction of a global secondary metabolism regulator, laeA gene.

We found that the culture broth of fungi showed anti-fungal activity against multidrug-sensitive budding yeast. However, we could not identify the anti-fungal compound due to the small quantity. Therefore, we attempted to increase the productivity of the target compound by the introduction of a global secondary metabolism regulator, laeA to the strain, which led to the successful isolation of 10-folds greater amount of MS-347a (1) than Aspergillus sp. FKI-5362. Compound 1 was not effective against Candida albicans and the detailed anti-fungal activity of 1 remains unverified. After our anti-fungal activity screening, 1 was found to inhibit the growth of broad plant pathogenic fungal species belonging to the Ascomycota. It is noteworthy that 1 showed little insecticidal activity against silkworms, suggesting its selective biological activity against plant pathogenic fungi. Our study implies that the combination strategy of multidrug-sensitive yeast and the introduction of laeA is useful for new anti-fungal drug discovery.

Suppression of NASH-Related HCC by Farnesyltransferase Inhibitor through Inhibition of Inflammation and Hypoxia-Inducible Factor-1α Expression.

Inflammatory processes play major roles in carcinogenesis and the progression of hepatocellular carcinoma (HCC) derived from non-alcoholic steatohepatitis (NASH). But, there are no therapies for NASH-related HCC, especially focusing on these critical steps. Previous studies have reported that farnesyltransferase inhibitors (FTIs) have anti-inflammatory and anti-tumor effects. However, the influence of FTIs on NASH-related HCC has not been elucidated. In hepatoblastoma and HCC cell lines, HepG2, Hep3B, and Huh-7, we confirmed the expression of hypoxia-inducible factor (HIF)-1α, an accelerator of tumor aggressiveness and the inflammatory response. We established NASH-related HCC models under inflammation and free fatty acid burden and confirmed that HIF-1α expression was increased under both conditions. Tipifarnib, which is an FTI, strongly suppressed increased HIF-1α, inhibited cell proliferation, and induced apoptosis. Simultaneously, intracellular interleukin-6 as an inflammation marker was increased under both conditions and significantly suppressed by tipifarnib. Additionally, tipifarnib suppressed the expression of phosphorylated nuclear factor-κB and transforming growth factor-ß. Finally, in a NASH-related HCC mouse model burdened with diethylnitrosamine and a high-fat diet, tipifarnib significantly reduced tumor nodule formation in association with decreased serum interleukin-6. In conclusion, tipifarnib has anti-tumor and anti-inflammatory effects in a NASH-related HCC model and may be a promising new agent to treat this disease.

Normal Variants of the Oral and Maxillofacial Region: Mimics and Pitfalls.

A normal variant is defined as an incidental, often asymptomatic, imaging finding that mimics a true pathologic condition. Given the complex anatomy and wide variety of normal variants in the oral and maxillofacial region, a thorough understanding of commonly encountered normal variants in this region is essential to avoid misinterpretation and unnecessary further imaging or interventions. Moreover, familiarity with normal variants that are known to become symptomatic at times is necessary to facilitate further workup and guide the treatment plan. Intraoral radiography and panoramic radiography, which are unique to oral and maxillofacial radiology, provide two-dimensional (2D) images. Hence, the overlapping of structures or the displacement of the tomographic layer on images can confuse radiologists. It is crucial to understand the principle of 2D imaging to avoid being confused by ghost images or optical illusions. In addition, understanding the normal development of the maxillofacial region is essential when interpreting maxillofacial images in children or young adults because the anatomy may be quite different from that of mature adults. Knowledge of changes in the jaw bone marrow and each tissue's growth rate is essential. It is also necessary to know when the tooth germ begins to calcify and the tooth erupts for diagnostic imaging of the maxillofacial region. The authors describe imaging findings and clinical manifestations of common normal variants in the oral and maxillofacial region, divided into four parts: the maxilla, mandible, tooth, and temporomandibular joint, and discuss the imaging approach used to differentiate normal variants from true pathologic conditions. Online supplemental material is available for this article. ©RSNA, 2022.

Complete biosynthetic pathways of ascofuranone and ascochlorin in Acremonium egyptiacum.

Ascofuranone (AF) and ascochlorin (AC) are meroterpenoids produced by various filamentous fungi, including Acremonium egyptiacum (synonym: Acremonium sclerotigenum), and exhibit diverse physiological activities. In particular, AF is a promising drug candidate against African trypanosomiasis and a potential anticancer lead compound. These compounds are supposedly biosynthesized through farnesylation of orsellinic acid, but the details have not been established. In this study, we present all of the reactions and responsible genes for AF and AC biosyntheses in A. egyptiacum, identified by heterologous expression, in vitro reconstruction, and gene deletion experiments with the aid of a genome-wide differential expression analysis. Both pathways share the common precursor, ilicicolin A epoxide, which is processed by the membrane-bound terpene cyclase (TPC) AscF in AC biosynthesis. AF biosynthesis branches from the precursor by hydroxylation at C-16 by the P450 monooxygenase AscH, followed by cyclization by a membrane-bound TPC AscI. All genes required for AC biosynthesis (ascABCDEFG) and a transcriptional factor (ascR) form a functional gene cluster, whereas those involved in the late steps of AF biosynthesis (ascHIJ) are present in another distantly located cluster. AF is therefore a rare example of fungal secondary metabolites requiring multilocus biosynthetic clusters, which are likely to be controlled by the single regulator, AscR. Finally, we achieved the selective production of AF in A. egyptiacum by genetically blocking the AC biosynthetic pathway; further manipulation of the strain will lead to the cost-effective mass production required for the clinical use of AF.

Texture analysis of low-flow vascular malformations in the oral and maxillofacial region: venous malformation vs. lymphatic malformation.

Purpose: It is challenging for radiologists to distinguish between venous malformations (VMs) and lymphatic malformations (LMs) using magnetic resonance imaging (MRI). Thus, this study aimed to differentiate VMs from LMs using non-contrast-enhanced MRI texture analysis. Material and methods: This retrospective case-control study included 12 LM patients (6 men and 6 women; mean age 43.58, range 7-85 years) and 29 VM patients (7 men and 22 women; mean age 53.10, range 19-76 years) who underwent MRI for suspected vascular malformations. LM and VM patients were identified by histopathological examination of tissues excised during surgery. The texture features of VM and LM were analysed using the open-access software MaZda version 3.3. Seventeen texture features were selected using the Fisher and probability of error and average correlation coefficient methods in MaZda from 279 original parameters calculated for VM and LM. Results: Among 17 selected texture features, the patients with LM and VM revealed significant differences in 1 histogram feature, 8 grey-level co-occurrence matrix (GLCM) features, and 1 grey-level run-length matrix feature. At the cut-off values of the histogram feature [skewness ≤ -0.131], and the GLCM features [S(0, 2) correlation ≥ 0.667, S(0, 3) correlation ≥ 0.451, S(0, 4) correlation ≥ 0.276, S(0, 5) correlation ≥ 0.389, S(1, 1) correlation ≥ 0.739, S(2, 2) correlation ≥ 0.446, S(2, -2) correlation ≥ 0.299, S(3, -3) correlation ≥ 0.091] had area under the curves of 0.724, 0.764, 0.773, 0.747, 0.733, 0.759, 0.730, 0.744 and 0.727, respectively. Conclusions: Non-contrast-enhanced MRI texture analysis allows us to differentiate between LMs and VMs.

Quantitative Assessment of the Apparent Diffusion Coefficient Values of the Inflammatory Connective Tissue Around the Mandibular Condyle in Rheumatoid Arthritis.

PURPOSE: Magnetic resonance imaging can detect soft- and hard-tissue abnormalities and has become the primary imaging modality for temporomandibular joints. However, few studies have quantitatively evaluated rheumatoid arthritis (RA) in temporomandibular joints using diffusion-weighted imaging. The purpose of this study was to assess the apparent diffusion coefficient (ADC) values of the inflammatory connective tissue around the mandibular condyle in RA. METHODS: This was a retrospective cohort study. We analyzed the magnetic resonance imaging studies of patients with suspected temporomandibular joint disorders performed between April 2008 and August 2020. The predictor variable was disease status (RA-y/n). The primary outcome variable was the mean of ADC values of the connective tissue around the mandibular condyle. The other variables were age and sex. Furthermore, the ADC values were compared between the 2 groups. Data were analyzed using a Mann-Whitney U test, Spearman's correlation coefficient, and a receiver operating characteristic curve. P < .05 was considered to indicate statistical significance. RESULTS: In total, 35 patients (18 normal patients and 17 patients with RA) were included. The mean ADC values were 1.26 ± 0.11 × 10-3 mm2/s and 1.60 ± 0.19 × 10-3 mm2/s in the control and RA groups, respectively (P < .001). Receiver operating characteristic analysis revealed that a cutoff of 1.37 for ADC values for RA provided an accuracy of 0.86. The sensitivity and specificity of ADC values were 0.94 and 0.83, respectively. CONCLUSIONS: ADC values of the inflammatory connective tissue around the mandibular condyle in RA were significantly higher in the RA group than those in the control group. This parameter might be useful for the quantitative evaluation of RA.

Quantitative Assessment of the Mandibular Condyle in Patients With Rheumatoid Arthritis Using Diffusion-Weighted Imaging.

PURPOSE: The purpose of this study was to quantitatively assess the mandibular condyle in patients with rheumatoid arthritis (RA) using the apparent diffusion coefficient (ADC) on diffusion-weighted imaging (DWI). PATIENTS AND METHODS: Thirty-one patients with RA and temporomandibular joint (TMJ) pain who underwent magnetic resonance imaging (MRI) examination of the TMJs at our hospital between August 2006 and March 2020 were included in this study. Twenty-one patients with normal TMJs who underwent MRI examination at our hospital between August 2006 and March 2020 were included as controls. The MRI findings were compared between the 2 groups. RESULTS: The mean ADC values of the mandibular condyle in patients with RA were 1.20 ± 0.17 × 10-3 mm2/second. The mean ADC values of the mandibular condyle in patients with RA were significantly greater than the controls (P < .01). Receiver operating characteristic curve analysis revealed a cutoff of 0.89 for the ADC values of the mandibular condyle in patients with RA. The receiver operating characteristic curve analysis revealed areas under the curve for maximum ADC values of 0.98. CONCLUSIONS: Our study found that the ADC on DWI could be used for the quantitative assessment of the mandibular condyle in patients with RA, which indicated that the ADC on DWI could be useful for predicting RA.

Increased Apparent Diffusion Coefficient Values of Masticatory Muscles on Diffusion-Weighted Magnetic Resonance Imaging in Patients With Temporomandibular Joint Disorder and Unilateral Pain.

PURPOSE: Myalgia of the masticatory muscles is difficult to evaluate quantitatively. The purpose of the present study was to quantitatively assess myalgia of the masticatory muscles in patients with temporomandibular disorders (TMDs) using the apparent diffusion coefficient (ADC) on diffusion-weighted magnetic resonance imaging (MRI). PATIENTS AND METHODS: Patients who had undergone MRI with clinically diagnosed TMDs according to the criteria of the American Academy of Orofacial Pain and unilateral temporomandibular joint pain from March 2015 to January 2017 were prospectively enrolled. The MRI techniques used included axial diffusion-weighted imaging (DWI) and short T1 inversion recovery imaging through the neck to the skull base. The regions of interest were drawn to completely include the right and left lateral pterygoid muscles, medial pterygoid muscles, and masseter muscles on a slice demonstrating the largest area of each muscle on the ADC map. We compared each masticatory muscle of the pain side with those of the contralateral side without pain. RESULTS: A total of 106 patients with TMD had met the inclusion criteria (18 males, 88 females; mean age, 48.7 years; range, 16 to 80). The mean ADC values of the masticatory muscles of the pain side were significantly greater than those of the no-pain sides (P < .01), as were those for the lateral pterygoid muscles (1.35 ± 0.79 × 10-3 mm2/second vs 1.13 ± 0.77 × 10-3 mm2/second), medial pterygoid muscles (1.28 ± 0.46 × 10-3 mm2/second vs 1.05 ± 0.69 × 10-3 mm2/second), masseter muscles (1.33 ± 0.78 × 10-3 mm2/second vs 1.09 ± 0.64 × 10-3 mm2/second). CONCLUSIONS: The ADC values of the masticatory muscles on the pain side were significantly greater than those of the contralateral side without pain. Our results suggest that DWI could be used to assess myalgia of the masticatory muscles quantitatively.

Parotid Lymphadenopathy Is Associated With Joint Effusion in Non-Neoplastic Temporomandibular Disorders.

PURPOSE: Lymphadenopathy often occurs in the setting of inflammation, with or without infection. We sought to elucidate any association of parotid lymphadenopathy with joint effusion in temporomandibular joint (TMJ) disorders. MATERIALS AND METHODS: We performed a retrospective cohort study. We analyzed the magnetic resonance imaging studies of patients with suspected TMJ disorders performed from April 2006 to March 2007. The degree of joint effusion was graded on sagittal T2-weighted spin echo images according to a commonly used system. On axial short T1-weighted short inversion recovery images, the number and short-axis diameter of the parotid lymph nodes were recorded. We performed analyses of the cluster-correlated data using the Mann-Whitney U test and Spearman's correlation coefficients. P < .05 was considered to indicate significance. To assess the possible predictive value of certain variables, a generalized linear model (generalized estimation equation) was constructed, considering the multiple measurements. RESULTS: A total of 402 TMJ disorders were analyzed from 201 patients during the study period. The number and size of the parotid lymph nodes identified was significantly greater in the patients with TMJ effusion (P < .01) than in those without effusion. CONCLUSION: In the present study, we found an association between parotid lymphadenopathy and joint effusion in TMJ disorders. These findings indicate that lymphadenopathy should be considered as an inflammation condition commonly associated with joint effusion in TMJ disorders.

Characteristic Magnetic Resonance Imaging Findings in Rheumatoid Arthritis of the Temporomandibular Joint: Focus on Abnormal Bone Marrow Signal of the Mandibular Condyle, Pannus, and Lymph Node Swelling in the Parotid Glands.

PURPOSE: The purpose of this study was to determine the characteristic magnetic resonance imaging (MRI) findings indicating bone and soft tissue involvement in patients with rheumatoid arthritis (RA) of the temporomandibular joints (TMJs). PATIENTS AND METHODS: Twenty-one patients with RA and TMJ pain who underwent MRI examination of the TMJs at the authors' hospital from August 2006 to December 2014 were included in this study. Twenty-two patients with normal TMJs who underwent MRI examination at the authors' hospital from November to December 2014 were included as controls. MRI findings were compared between the 2 groups. RESULTS: MRI findings of RA in the TMJ included 1) abnormal disc position (95.2%), 2) abnormal disc morphology (83.3%), 3) joint effusion (30.9%), 4) osseous changes in the mandibular condyle (83.3%), 5) synovial proliferation (pannus; 85.7%), 6) erosion of the articular eminence and glenoid fossa (9.52%), 7) deformity of the articular eminence and glenoid fossa (16.6%), 8) abnormal bone marrow signal in the mandibular condyle (83.3%), and 9) swelling of lymph nodes in the parotid glands (78.5%). The abnormal bone marrow signal and pannus in the mandibular condyle and lymph node swelling in the parotid glands were markedly more common in patients with RA than in controls. CONCLUSIONS: MRI findings of RA of the TMJs were characterized by bone and soft tissue involvement, including abnormal bone marrow signal of the mandibular condyle, pannus, and swelling of lymph nodes in the parotid glands. These characteristic MRI findings could be useful in detecting RA in the TMJ in a clinical situation.

A surgical case of inflammatory pseudotumor by hepatic anisakiasis.

Anisakiasis is a parasitic infection caused by the ingestion of raw or undercooked seafood infected with Anisakis larvae. It generally affects the gastrointestinal tract, particularly the stomach, but very rare cases have been reported in which infection of the liver leads to the formation of inflammatory pseudotumors. We herein report an extremely rare case of an inflammatory pseudotumor induced by hepatic anisakiasis that was laparoscopically resected for the purpose of both diagnosis and treatment. A 51-year-old woman underwent a routine medical checkup by ultrasound examination, which incidentally detected a 15-mm mass on the surface of S6 of the liver. Because a malignant tumor could not be ruled out on several preoperative imaging studies, laparoscopic partial resection of the liver was performed. Histopathological examination revealed Anisakis larva in the inflammatory pseudotumor, suggesting hepatic anisakiasis. This report describes an extremely rare case of an inflammatory pseudotumor induced by hepatic anisakiasis. Because the preoperative diagnosis could not be obtained by several imaging modalities, laparoscopic liver resection with a sufficient margin might be suitable for diagnosis and treatment of this disease.

Texture analysis using short-tau inversion recovery magnetic resonance images to differentiate squamous cell carcinoma of the gingiva from medication-related osteonecrosis of the jaw.

OBJECTIVES: Despite the difficulty in distinguishing between squamous cell carcinoma (SCC) and medication-related osteonecrosis of the jaw (MRONJ) on the basis of medical imaging examinations, the two conditions have completely different treatment methods and prognoses. Therefore, differentiation of SCC from MRONJ on imaging examinations is very important. This study aimed to distinguish SCC from MRONJ by performing texture analysis using magnetic resonance imaging (MRI) short-tau inversion recovery images. METHODS: This retrospective case-control study included 14 patients with SCC of the lower gingiva and 35 with MRONJ of the mandible who underwent MRI and computed tomography (CT) for suspected SCC or MRONJ. SCC was identified by histopathological examination of tissues excised during surgery. The radiomics features of SCC and MRONJ were analyzed using the open-access software MaZda version 3.3 (Technical University of Lodz, Institute of Electronics, Poland). CT was used to evaluate the presence or absence of qualitative findings (sclerosis, sequestrum, osteolysis, periosteal reaction, and cellulitis) of SCC and MRONJ. RESULTS: Among the 19 texture features selected using MaZda feature-reduction methods, SCC of the gingiva and MRONJ of the mandible revealed differences in two histogram features, one absolute gradient feature, and 16 Gy level co-occurrence matrix features. In particular, the percentile, angular second moment, entropy, and difference entropy exhibited excellent diagnostic performance. CONCLUSION: Non-contrast-enhanced MRI texture analysis revealed differences in texture parameters between mandibular SCC and mandibular MRONJ. MRI texture analysis can be a new noninvasive quantitative method for distinguishing between SCC and MRONJ.

Robotic spleen-preserving distal pancreatectomy using the first domestic surgical robot platform (the hinotori™ Surgical Robot System): a case report.

BACKGROUND: Robotic pancreatectomy has been performed worldwide mainly using the da Vinci® Surgical System (Intuitive Surgical, Inc., Sunnyvale, CA, USA). Recently, because of the death of some patents related to the da Vinci® system, new surgical robot systems have been introduced that are characterized by unique technical refinements. In Japan, the hinotori™ Surgical Robot System (Medicaroid Corporation, Kobe, Japan) was approved for use in gastroenterological surgery in October 2022. Since then, we have attempted complicated procedures using this robot. In this report, we report our first experience performing spleen-preserving distal pancreatectomy with conservation of the splenic artery and vein using this first Japanese domestic surgical robot. CASE PRESENTATION: The patient was a 58-year-old woman with a mass in the pancreatic tail identified during medical screening. Further examinations resulted in a diagnosis of a pancreatic neuroendocrine tumor. The patient consented to surgical resection, and we planned robotic spleen-preserving distal pancreatectomy with conservation of the splenic artery and vein, using the hinotori™. Five trocars, including one port for the assistant surgeon, were placed in the upper abdomen. The operating unit was rolled in from the patient's right side. The pivot position was set for each robotic arm, and this setting was specific to the hinotori™. The cockpit surgeon performed all surgical procedures, excluding port placement and pancreatic transection. There were no unrecoverable device errors during the operation. The operation time was 531 min, and blood loss was 192 ml. The postoperative course was uneventful. We were able to safely perform this highly complicated surgery for a pancreatic tumor using the first Japanese domestic surgical robot platform. CONCLUSIONS: The first Japanese domestic surgical robot platform, hinotori™, has different features from those of the da Vinci® and performed sufficiently as a surgical robot system in highly advanced pancreatic surgery.

A case of intrahepatic mass-forming portal biliopathy mimicking intrahepatic cholangiocarcinoma.

A 75-year-old man was referred to our department because of an enlarging intrahepatic mass detected on magnetic resonance imaging (MRI) follow-up for another disease. MRI showed hypointensity on T1-weighted imaging and hyperintensity on T2-weighted imaging in liver segment 4. Abdominal plain computed tomography (CT) indicated a low-density lesion with an unclear boundary, measuring approximately 4 cm × 3 cm in liver segment 4. Dynamic CT showed early rim enhancement and gradual central enhancement. Contrast-enhanced CT also showed occlusion of the portal vein in segment 4. As the possibility of intrahepatic cholangiocarcinoma could not be excluded on imaging studies, we performed laparoscopic left medial sectionectomy. Histologically, the lesion showed diminished numbers of hepatocytes with increased collagen fibers compared with normal, with no patent portal vein. We considered this lesion a reactive lesion caused by collapse of the liver parenchyma owing to localized obstruction and loss of the portal vein. This lesion was pathologically diagnosed as portal biliopathy. We experienced an extremely rare case of intrahepatic mass-forming portal biliopathy that mimicked a hepatic tumor, which was diagnosed by laparoscopic resection. Portal biliopathy rarely forms intrahepatic mass lesions and must be distinguished from a malignant hepatic tumor.

Graphical user interface-based convolutional neural network models for detecting nasopalatine duct cysts using panoramic radiography.

Nasopalatine duct cysts are difficult to detect on panoramic radiographs due to obstructive shadows and are often overlooked. Therefore, sensitive detection using panoramic radiography is clinically important. This study aimed to create a trained model to detect nasopalatine duct cysts from panoramic radiographs in a graphical user interface-based environment. This study was conducted on panoramic radiographs and CT images of 115 patients with nasopalatine duct cysts. As controls, 230 age- and sex-matched patients without cysts were selected from the same database. The 345 pre-processed panoramic radiographs were divided into 216 training data sets, 54 validation data sets, and 75 test data sets. Deep learning was performed for 400 epochs using pretrained-LeNet and pretrained-VGG16 as the convolutional neural networks to classify the cysts. The deep learning system's accuracy, sensitivity, and specificity using LeNet and VGG16 were calculated. LeNet and VGG16 showed an accuracy rate of 85.3% and 88.0%, respectively. A simple deep learning method using a graphical user interface-based Windows machine was able to create a trained model to detect nasopalatine duct cysts from panoramic radiographs, and may be used to prevent such cysts being overlooked during imaging.

Purification and characterization of a glutaminase enzyme accounting for the majority of glutaminase activity in Aspergillus sojae under solid-state culture.

Glutaminase, an enzyme that hydrolyzes L-glutamine to L-glutamate, plays an important role in the production of fermented foods by enhancing the umami taste. In this study, we found ten glutaminase genes in the Aspergillus sojae genome by conducting a BLAST search of the characterized glutaminase sequence. We subsequently constructed glutaminase gene disruptants. The glutaminase activity of the gahB disruptant was decreased by approximately 90 % in A. sojae and Aspergillus oryzae, indicating that this enzyme (GahB) accounted for the majority of the glutaminase activity in Aspergillus species. Subsequently, GahB protein was purified from the AsgahB-overexpressing transformant and characterized. The molecular mass was estimated to be approximately 110 and 259 kDa by SDS-PAGE and gel filtration chromatography, respectively, indicating that the native form of AsGahB was a dimer. The optimal pH was 9.0, and the optimal temperature was 50 °C. Analysis of substrate specificity revealed that AsGahB had peptidoglutaminase-asparaginase activity, similar to AsGahA, but preferred free L-glutamine to free L-asparagine, C-terminal glutaminyl, and asparaginyl residues in peptides.

Identification of the glutaminase genes of Aspergillus sojae involved in glutamate production during soy sauce fermentation.

Glutaminase, an enzyme that catalyzes the conversion of L-glutamine to L-glutamate, enhances the umami taste in soy sauce. The Aspergillus sojae genome contains 10 glutaminase genes. In this study, we estimated that approximately 60% of the glutamate in soy sauce is produced through the glutaminase reaction. To determine which glutaminase is involved in soy sauce glutamate production, we prepared soy sauces using single and multiple glutaminase gene disruptants of A. sojae. The glutamate concentration in soy sauce prepared using the ΔgahA-ΔgahB-ΔggtA-Δgls disruptant was approximately 60% lower than that in the control strain, whereas it was decreased by approximately 20-30% in the ΔgahA-ΔgahB disruptant. However, the glutamate concentration was unchanged in the soy sauces prepared using the ΔgahA-ΔggtA-Δgls and ΔgahB-ΔggtA-Δgls disruptants. These results indicate that four glutaminases are involved in glutamate production in soy sauce, and that the peptidoglutaminase activities of GahA and GahB increase the glutamate concentration in soy sauce.

Robotic distal pancreatectomy using a docking-free system (the hinotori™ Surgical Robot System).

BACKGROUND: Although robotic surgery has rapidly spread in pancreatectomy [1], the procedure is performed by the da Vinci™ Surgical System (Intuitive Surgical Inc., CA), the most common surgical robot in the world [2]. We herein present our first experience of robotic distal pancreatectomy using a new Japanese surgical robot named the hinotori™ Surgical Robot System (Medicaroid Corporation, Kobe, Japan). METHODS: A 68-year-old man who was found to have the mass lesion in the pancreatic tail in a medical examination. Investigations, including various imaging studies suggested a diagnosis of pancreatic cancer (Fig. 1). The patient was considered for robotic pancreatectomy. RESULTS: Five trocars, including one port for the assistant surgeon, were placed at the upper abdomen. The operation unit was rolled in from the right side (Fig. 2). The patient successfully underwent robotic distal pancreatectomy combined with dissection of the regional lymph nodes using the hinotori™ system. The cockpit surgeon performed all procedures, excluding port placement, vessel clipping, and transection of the pancreas. There were no unrecoverable device errors in this operation. The total operation time was 473 minutes, and the estimated blood loss was 182 ml. The postoperative course was uneventful, and hospital length of stay was 10 days. Pathological diagnosis was pancreatic cancer, T1N1M0, Stage ⅡB. Adjuvant chemotherapy using S-1 was administered, and he has survived without recurrence for 3 months after the curative resection. CONCLUSIONS: This is the first report of robotic pancreatectomy using the hinotori™ system, which showed the favorable perioperative results. The accumulation of experience and further studies are required to confirm its clinical benefits.

Detecting lymphadenopathy affected by peri-implantitis using diffusion-weighted magnetic resonance imaging.

PURPOSE: This study aimed to assess peri-implantitis-induced lymphadenopathy on diffusion-weighted imaging (DWI). METHODS: This retrospective study was conducted from October 2017 to March 2020 in patients with and without peri-implantitis who underwent magnetic resonance imaging (MRI). Patients in the peri-implantitis group had radiographically confirmed loss of alveolar bone > 2.0 mm and clinical findings such as bleeding on probing, suppuration of tissues surrounding the teeth, probing-pocket depth of > 4 mm, pain on implant function, and clinical implant mobility, whereas those without peri-implantitis had none of the abovementioned clinical findings. The Mann-Whitney U test was used to compare groups, using lymph node (LN) short-axis diameters and apparent diffusion coefficients (ADCs) as the criterion variables and presence or absence of peri-implantitis as the explanatory variable. Receiver operating characteristic (ROC) analysis was done to investigate the effectiveness of LN size and ADC use in detecting peri-implantitis-induced lymphadenopathy. Statistical significance was established at P < 0.05. RESULTS: There were 66 lymph nodes from 12 patients analyzed. The mean LN size and ADC were significantly higher in patients with peri-implantitis than in those without (P < 0.01). ROC curve analysis showed cut-off LN sizes of 4.78 and 4.84 mm and cut-off ADCs of 1.12 and 1.09 for lymphadenopathy affected by peri-implantitis corresponding to levels IB and II, respectively. CONCLUSIONS: Cervical lymphadenopathy may be an inflammatory finding associated with peri-implantitis.