Analysis of ribonucleotide content in the genomic DNA of ribonuclease H2 A subunit (RH2A)-knockout NIH3T3 cells after transient expression of wild-type RH2A or RH2A variants with an Aicardi-Goutières syndrome-causing mutation.

Ribonuclease (RNase) H2 is involved in the removal of ribonucleotides embedded in genomic DNA. Eukaryotic RNase H2 is a heterotrimer consisting of the catalytic A subunit (RH2A) and the accessory B and C subunits. This study aimed to compare the cellular activities of wild-type ribonuclease (RNase) H2 and its variants with a mutation causing neuroinflammatory autoimmune disease, Aicardi-Goutières syndrome (AGS). We first analyzed cellular RNase H2 activity and ribonucleotide content in the genomic DNA of RH2A-knockout (KO) mouse fibroblast NIH3T3 cells after transfection with a transient expression plasmid encoding mouse wild-type RH2A. From 4 h after transfection, the RNase H2 activity increased and the amount of ribonucleotides decreased, as compared with the corresponding non-transfected RH2A-KO cells. This demonstrated the rapidness of ribonucleotide turnover in mammalian genomic DNA and the importance of continuous expression of RNase H2 to maintain the ribonucleotide amount low. Next, we expressed mouse RH2A variants with a mutation corresponding to a human AGS-causing mutation in RH2A-KO NIH3T3 cells. Neither increase in RNase H2 activity nor decrease in ribonucleotide amount was observed for G37S; however, both conditions were observed for N213I and R293H. This corresponded with our previous results on the activity of recombinant human RNase H2 variants.

Multiple mutations in RNA polymerase ß-subunit gene (rpoB) in Streptomyces incarnatus NRRL8089 enhance production of antiviral antibiotic sinefungin: modeling rif cluster region by density functional theory.

Streptomyces incarnatus NRRL8089 produces the antiviral, antifungal, antiprotozoal nucleoside antibiotic sinefungin. To enhance sinefungin production, multiple mutations were introduced to the rpoB gene encoding RNA polymerase (RNAP) ß-subunit at the target residues, D447, S453, H457, and R460. Sparse regression analysis using elastic-net lasso-ridge penalties on previously reported H457X mutations identified a numeric parameter set, which suggested that H457R/Y/F may cause production enhancement. H457R/R460C mutation successfully enhanced the sinefungin production by 3-fold, while other groups of mutations, such as D447G/R460C or D447G/H457Y, made moderate or even negative effects. To identify why the rif cluster residues have diverse effects on sinefungin production, an RNAP/DNA/mRNA complex model was constructed by homology modeling and molecular dynamics simulation. The 4 residues were located near the mRNA strand. Density functional theory-based calculation suggested that D447, H457, and R460 are in direct contact with ribonucleotide, and partially positive charges are induced by negatively charged chain of mRNA.

Characterization of six recombinant human RNase H2 bearing Aicardi-Goutiéres syndrome causing mutations.

Mammalian RNase H2 is a heterotrimeric enzyme consisting of one catalytic subunit (A) and two accessory subunits (B and C). RNase H2 is involved in the removal of a single ribonucleotide embedded in genomic DNA and removal of RNA of RNA/DNA hybrids. In humans, mutation of the RNase H2 gene causes a severe neuroinflammatory disorder Aicardi-Goutières syndrome (AGS). Here, we examined the activity and stability of six recombinant human RNase H2 variants bearing one AGS-causing mutation, A-G37S (Gly37 in the A subunit is replaced with Ser), A-N212I, A-R291H, B-A177T, B-V185G, or C-R69W. The activity of A-G37S was 0.3-1% of that of the wild-type RNase H2 (WT), while those of other five variants were 51-120%. In circular dichroism measurement, the melting temperatures of variants were 50-53°C, lower than that of WT (56°C). These results suggested that A-G37S had decreased activity and stability than WT, while other five variants had decreased stability but retained activity. In gel filtration chromatography of the purified enzyme preparation, WT migrated as a heterotrimer, while A-R291H eluted in two separate peaks containing either the heterotrimer or only the A subunit, suggesting that some AGS-causing mutations affect the heterotrimer-forming stability of RNase H2.

Enhanced expression of gene coding for ß-endorphin in human monocytic cells exposed to pulsed radio frequency electric fields through thermal and non-thermal effects.

BACKGROUND: The enhanced expression of endogenous opioid peptides, including ß-endorphin, has been implicated in the mechanism of action of pulsed radio frequency (PRF) application in pain modulation. Because thermal effects cannot be separated from the physical property of PRF application to biological tissues, we evaluated whether temperatures higher than that of the normal body temperature (37°C) modulate mRNA expression for the precursor of ß-endorphin, proopiomelanocortin (POMC) in human monocytic cells THP-1. We also attempted to examine whether mechanisms other than thermal effects also modulate such gene expression. METHODS AND RESULTS: The mRNA for POMC in THP-1 cells increased by a 15-minutes incubation at 42°C, 45°C, or 70°C without PRF application as compared with that in cells incubated at 37°C. On the other hand, gene expression for POMC in cells incubated at 20°C as well as at 37°C with PRF application for 15 minutes increased as compared to that in cells incubated at 37°C without PRF application. Continuous radio frequency at 70°C but not PRF provoked apoptotic cell death at 1-2 hour, and necrotic cell death at 24 hours after the RF application. CONCLUSION: A simple experimental system using human monocytic cells in culture demonstrated that a 15 minute elevation of temperature above 37°C enhanced gene expression for POMC in THP-1 cells, while a 15 minute application of PRF to these cells incubated at 37°C or lower, also enhanced gene expression, indicating that temperature-independent mechanisms as well as thermal effects may be involved in such gene expression.

Involvement of superoxide generated by NADPH oxidase in the shedding of procoagulant vesicles from human monocytic cells exposed to bupivacaine.

It is known that a variety of sized procoagulant vesicles that express tissue factor are released from several types of cells including monocytes by mechanisms related to the induction of apoptosis, while it has not yet been evaluated whether superoxide is involved in the production of such vesicles. Here, we report that a local anesthetic bupivacaine induces apoptosis in human monocytic cells THP-1 within a short observation period, where the shedding of procoagulant vesicles is associated. The property as procoagulant vesicles was evaluated using flow cytometry by the binding of FITC-conjugated fibrinogen to vesicles in the presence of fresh frozen plasma and the suppression of this binding by heparin. Bupivacaine (1 mg/ml) increased the apoptotic cells and procoagulant vesicles. LY294002 (100 µM), that inhibits the recruiting of intracellular component of NADPH oxidase to construct the activated form of this enzyme complex, or superoxide dismutase (1500 unit/ml) suppressed bupivacaine-provoked induction of apoptosis and the increase of procoagulant vesicles. We suggest that this simple experimental system is useful to explore the molecular mechanisms of action of superoxide in the shedding of procoagulant vesicles from human monocytic cells.

Dual red imaging (novel advanced endoscopy) can increase visibility and can predict the depth in diagnosing esophageal varices.

BACKGROUND: Dual red imaging (DRI) is a new technology that can increase the visibility of deeper veins compared with narrow band imaging (NBI). As esophageal varices (EVs) are a vascular disease occurring in the submucosal layer, their visibility might be increased by DRI. We prospectively clarified whether the visibility of EVs with red color sign (RCS) can be increased by DRI, and clarified the relation between the visibility scores and the obtained endoscopic ultrasound (EUS) images. METHODS: Forty patients were enrolled. The visibility of the EVs on DRI and NBI endoscopic images was evaluated by five observers in a blinded manner and was compared with a white light image (bad, 0; equal, 1; good, 2). The diameter of the lumen and the depth of the EVs and RCS from the epithelium were measured by EUS. The relation between the visibility scores and the EUS findings was investigated. RESULTS: The DRI scores were 1.66 ± 0.34 for the EV substance and 1.79 ± 0.28 for the RCS, whereas the NBI scores were 0.68 ± 0.38 and 0.41 ± 0.28, respectively. A significant negative correlation was found between the depth and the visibility score (r = -0.505, p = 0.001 for EVs; r = -0.458, p = 0.003 for RCS). CONCLUSIONS: DRI increased the visibility of the EVs and RCS. The visibility of the EVs or RCS in the shallower position was more enhanced by DRI. Visual recognition of the changing degrees of visibility by DRI enables the prediction of the depth of EVs.

L-Arginine L-Glutamate Enhances Gastric Motor Function in Rats and Dogs and Improves Delayed Gastric Emptying in Dogs.

Amino acids are not only constituents of proteins, but also have multiple physiologic functions. Recent findings have revealed that ingested amino acids either activate luminal receptors or are metabolized, causing physiologic reactions in the gastrointestinal (GI) tract. We examined the effect of oral L-arginine L-glutamate (ArgGlu), a pharmaceutical amino acid salt used i.v. for the treatment of hyperammonemia, on gastric motor function in rats and dogs. Gastric emptying was determined using phenol red and 13C-breath test methods, whereas gastric relaxation was determined using the barostat method. ArgGlu (10-30 mg/kg, p.o.) dose-dependently promoted gastric emptying in rats. This effect was dependent on vagus nerve activation and comparable to that of the prokinetic mosapride. Intragastric ArgGlu (3-30 mg/kg intragastrically) also dose-dependently enhanced adaptive relaxation of rat stomachs, which was negated not by vagotomy of gastric branches, but by pretreatment with N omega-nitro-L-arginine methyl ester (20 mg/kg i.v.), a nitric oxide synthase inhibitor. Its relaxing effect on the stomach was also confirmed in dogs and was equally as efficacious as treatment with sumatriptan (1-3 mg/kg s.c.). ArgGlu (30 mg/kg p.o.) significantly reduced the half gastric emptying time in clonidine-induced delayed gastric emptying of solids in dogs, and its effect was comparable to that of cisapride (3 mg/kg p.o.). This study demonstrated that the pharmaceutical ingredient ArgGlu, currently used i.v., enhanced gastric motor function when administered orally, suggesting that it could be a new oral medicine indicated for treatment of upper GI hypofunction or dysfunction like functional dyspepsia.

Optimal injection rate of ultrasound contrast agent for evaluation of focal liver lesions using an automatic power injector: a pilot study.

OBJECTIVE: To determine the optimal bolus injection rate of ultrasound (US) contrast agent in vascular imaging for focal liver lesions. METHODS: Thirteen patients with 13 focal liver lesions (5 hepatocellular carcinomas (HCCs) with cirrhosis, 4 liver metastases, 2 hemangiomas, 1 intrahepatic cholangiocarcinoma, 1 focal nodular hyperplasia) received two bolus injections of Sonazoid (at 0.5 and 2.0 mL/s) using an automatic power injector. The lesion-to-liver contrast ratio at peak enhancement was quantitatively evaluated. Enhancement of the lesions compared to liver parenchyma was assessed by two independent readers using a five-point scale and qualitatively evaluated by receiver operating characteristic (ROC) analysis. RESULTS: For all lesions, the contrast ratio was not significantly different between the two injection rates. For HCCs, the contrast ratio was higher at 0.5 mL/s (7.41 ± 6.56) than at 2.0 mL/s (4.28 ± 4.66, p = 0.025). For all lesions, the mean area under the ROC curve (AUC) was not significantly different between the two injection rates. For HCCs, the AUC was greater at 0.5 mL/s than at 2.0 mL/s (AUC: 0.86, p = 0.013). CONCLUSION: In contrast-enhanced US, an injection rate of 0.5 mL/s is superior to an injection rate of 2.0 mL/s for the quantitative and qualitative analysis of HCCs in the cirrhotic liver.

Relationship between liver tissue stiffness and histopathological findings analyzed by shear wave elastography and compression testing in rats with non-alcoholic steatohepatitis.

PURPOSE: The aim of the present study was to investigate two methods of determining liver stiffness in rats with various degrees of non-alcoholic steatohepatitis induced by a methionine- and choline-deficient (MCD) diet by comparing each finding with reference to histopathological liver findings. METHODS: Twenty male Wister rats were fed an MCD diet for up to 32 weeks, and four were fed a normal diet. Ultrasound-based shear wave elastography (SWE) and mechanical compression testing using an Instron Universal Testing machine were performed on each rat at designated time points. After each examination, liver histopathology was analyzed to evaluate the degrees of steatosis, inflammation, and fibrosis based on non-alcoholic fatty liver disease (NAFLD) activity score, and each finding was compared with reference to liver histopathologic findings. RESULTS: Median liver stiffness values measured using SWE showed a stepwise increase with increasing histological inflammation score (P = 0.002), hepatic fibrosis stage (P = 0.029), ballooning score (P = 0.012), and steatosis grade (P = 0.030). Median liver stiffness measured using an Instron machine showed a stepwise increase only with increasing histological fibrosis stage (P = 0.033). CONCLUSIONS: Degree of liver stiffness measured by SWE and the Instron machine differed. SWE reflected mainly inflammation, whereas Instron machine-derived values primarily reflected fibrosis. This is the main source of discrepancies between measurements made with these two modalities.

Irreversible electroporation for nonthermal tumor ablation in patients with hepatocellular carcinoma: initial clinical experience in Japan.

PURPOSE: This clinical study was conducted to evaluate the safety and short-term outcomes of irreversible electroporation (IRE) for the treatment of patients with hepatocellular carcinoma (HCC) in Japan. MATERIALS AND METHODS: The study was designed in a prospective setting. Five patients (3 men and 2 women; mean age, 66.6 ± 5.8 years) with 6 HCCs were enrolled and treated using percutaneous ultrasound (US)-guided IRE. Safety was assessed based on adverse events and laboratory values. Local control was assessed using contrast-enhanced US with a perflubutane microbubble contrast agent, contrast-enhanced multiphase CT, and gadoxetic acid-enhanced MRI (EOB-MRI) at designated points. RESULTS: The tumors ranged in diameter from 11 to 28 mm (mean diameter, 17.5 ± 6.3 mm). Five of the 6 tumors (83 %) were successfully treated, with no local recurrence to date (mean follow-up 244 ± 55 days). In 1 lesion located in liver segment 1, residual tumor was diagnosed at 7 days after intervention by follow-up EOB-MRI. No serious complications related to the IRE procedure were observed. CONCLUSION: The results of this study suggest that image-guided percutaneous IRE can achieve satisfactory local disease control, particularly for small HCCs, and is well tolerated by patients.

Radiologic-pathologic correlation of three-dimensional shear-wave elastographic findings in assessing the liver ablation volume after radiofrequency ablation.

AIM: To evaluate the usefulness of three-dimensional (3D) shear-wave elastography (SWE) in assessing the liver ablation volume after radiofrequency (RF) ablation. METHODS: RF ablation was performed in vivo in 10 rat livers using a 15-gauge expandable RF needle. 3D SWE as well as B-mode ultrasound (US) were performed 15 min after ablation. The acquired 3D volume data were rendered as multislice images (interslice distance: 1.10 mm), and the estimated ablation volumes were calculated. The 3D SWE findings were compared against digitized photographs of gross pathological and histopathological specimens of the livers obtained in the same sectional planes as the 3D SWE multislice images. The ablation volumes were also estimated by gross pathological examination of the livers, and the results were then compared with those obtained by 3D SWE. RESULTS: In B-mode US images, the ablation zone appeared as a hypoechoic area with a peripheral hyperechoic rim; however, the findings were too indistinct to be useful for estimating the ablation area. 3D SWE depicted the ablation area and volume more clearly. In the images showing the largest ablation area, the mean kPa values of the peripheral rim, central zone, and non-ablated zone were 13.1 ± 1.5 kPa, 59.1 ± 21.9 kPa, and 4.3 ± 0.8 kPa, respectively. The ablation volumes depicted by 3D SWE correlated well with those estimated from gross pathological examination (r (2) = 0.9305, P = 0.00001). The congestion and diapedesis of red blood cells observed in histopathological examination were greater in the peripheral rim of the ablation zone than in the central zone. CONCLUSION: 3D SWE outperforms B-mode US in delineating ablated areas in the liver and is therefore more reliable for spatially delineating thermal lesions created by RF ablation.

[Anesthetic management for a pediatric patient of Klippel-Trenaunay syndrome with giant head by hydrocephalus].

Klippel-Trenaunay syndrome (KTS) is a rare disorder associated with the triad of 1) capillary vascular malformation, 2) varicose veins and/or venous malformation, 3) and soft tissue and/or bony hypertrophy. A six-month old, 6.0-kg-weight male pediatric patient was scheduled for ventriculo-peritoneal shunt operation for hydrocephalus caused by obstructive aqueductus cerebri. At the age of three months, he was diagnosed as KTS by extensive capillary vascular malformation and soft tissue hypertrophy of the right leg. Physical examination showed prominent vascular malformation over his anterior thoracic and abdominal wall, and soft tissue hypertrophy was only on his right leg. Simultaneously, he was complicated with congenital hydrocephalus because of obstructive aqueductus cerebri. His head and skull were enlarged and his head measurement reached 55 cm (chest measurement 32 cm). Anesthetic management of KTS patients should be prepared with blood transfusion against massive hemorrhage and hypovolemic shock. Furthermore, KTS patients should be always considered to have airway difficulty due to the soft tissue hypertrophy, upper and airway hemangiomas. Therefore, we planned safer tracheal intubation following practice guidelines for management of the difficult airway.

S-methylmethionine is involved in the salinity tolerance of Arabidopsis thaliana plants at germination and early growth stages.

Methionine (Met) is biosynthesized by the activated methyl cycle and S-methylmethionine (SMM) cycle in one-carbon (C1) metabolism in plants. It is converted to S-adenosylmethionine (SAM) which serves as a precursor for many metabolites including glycinebetaine, methylated polyols, polyamines and ethylene which accumulate in plants in response to salinity. We have investigated how the Met biosynthetic pathway is regulated under saline conditions at the transcriptional level in Arabidopsis thaliana plants. Within Met biosynthesis-related genes, the expression of homocysteine methyltransferase (HMT) and methionine methyltransferase (MMT) genes in SMM cycle had altered toward increasing Met production by the presence of NaCl. We have determined the salinity tolerance of an Arabidopsis mmt mutant with an insertional mutation in the single copy of the AtMMT gene. Although the mmt mutant showed comparable germination and shoot growth with wild type under normal conditions, NaCl treatment caused severe repression of germination rate and shoot growth in the mmt mutant compared with in the wild type. These results indicate that the utilization of SMM is important for the salinity tolerance of Arabidopsis plants at the germination and early growth stages.

A new immune-modulating diet enriched with whey-hydrolyzed peptide, fermented milk, and isomaltulose attenuates gut ischemia-reperfusion injury in mice.

BACKGROUND & AIMS: Gut ischemia-reperfusion (I/R) is considered an important mechanism underlying multiple organ failure after severe surgical insults. We previously demonstrated an enteral diet enriched with whey-hydrolyzed peptide, fermented milk, and isomaltulose to have anti-inflammatory effects in a concanavalin A-induced hepatitis model. Here, we investigated whether the immune-modulating diet (IMD), could prevent systemic inflammation, thereby improving survival in a gut I/R model. METHODS: Mice were randomized into control enteral diet (n = 58) or IMD (n = 56) for 2 weeks' feeding. In experiment 1, 39 mice underwent 45 min of gut ischemia, and were sacrificed at 3 h after reperfusion to collect blood samples. Plasma IL-6 and glucose levels were measured. In experiment 2, 75 mice underwent 60 min of ischemia, and their survival was observed until 48 h. RESULTS: Plasma IL-6 and glucose levels of the IMD group were significantly lower than those of control mice. In association with these changes, the IMD improved survival rate at early time points (12 and 30 h) after gut I/R (p < 0.05, χ(2) test). CONCLUSIONS: Nutritional management with the IMD may be useful for preventing systemic inflammatory response after gut I/R.

Dietary whey protein hydrolysate suppresses development of atopic dermatitis-like skin lesions induced by mite antigen in NC/Nga mice.

BACKGROUND: Oral administration of enzymatic hydrolysate of cow's milk whey protein (WPH) has been reported to produce an anti-inflammatory effect. Since inflammation plays a role in dermatitis of allergic disease, we examined the influence of WPH on the development of atopic dermatitis (AD)-like skin lesions, induced in NC/Nga mice by the mite antigen Dermatophagoides pteronyssinus (Dp). METHODS: AD-like skin lesions were induced on the pinnae and backs of NC/Nga mice by daily application of Dp for 4 weeks. Mice were fed cow's milk casein (control), WPH or casein protein hydrolysate (CPH) diets for 2 weeks prior to Dp application. Clinical skin conditions were evaluated periodically by a clinical severity score, total serum IgE and soluble E-selectin levels were measured by enzyme linked immunosorbent assay (ELISA). RESULTS: WPH-fed mice showed significantly less AD-like skin lesions than those fed casein diets at 2 and 4 weeks after Dp application. In contrast, CPH-fed mice had manifestations in a similar manner as casein-fed mice did, and did not show an inhibitory effect. Serum soluble E-selectin levels, known as a marker of disease activity in AD patients, were significantly lower in the WPH diet group. CONCLUSIONS: Our results suggest that in addition to its hypoallergenicity an anti-inflammatory function, dietary WPH might be useful for reducing the severity of AD-like skin lesions.