Sofosbuvir Suppresses the Genome Replication of DENV1 in Human Hepatic Huh7 Cells

Dengue virus (DENV) causes dengue fever and dengue hemorrhagic fever, and DENV infection kills 20,000 people annually worldwide. Therefore, the development of anti-DENV drugs is urgently needed. Sofosbuvir (SOF) is an effective drug for HCV-related diseases, and its triphosphorylated metabolite inhibits viral RNA synthesis by the RNA-dependent RNA polymerase (RdRp) of HCV. (2'R)-2'-Deoxy-2'-fluoro-2'-methyluridine (FMeU) is the dephosphorylated metabolite produced from SOF. The effects of SOF and FMeU on DENV1 replication were analyzed using two DENV1 replicon-based methods that we previously established. First, a replicon-harboring cell assay showed that DENV1 replicon replication in human hepatic Huh7 cells was decreased by SOF but not by FMeU. Second, a transient replicon assay showed that DENV1 replicon replication in Huh7 cells was decreased by SOF; however, in hamster kidney BHK-21 cells, it was not suppressed by SOF. Additionally, the replicon replication in Huh7 and BHK-21 cells was not affected by FMeU. Moreover, we assessed the effects of SOF on infectious DENV1 production. SOF suppressed infectious DENV1 production in Huh7 cells but not in monkey kidney Vero cells. To examine the substrate recognition of the HCV and DENV1 RdRps, the complex conformation of SOF-containing DENV1 RdRp or HCV RdRp was predicted using AlphaFold 2. These results indicate that SOF may be used as a treatment for DENV1 infection.

A pyridinium‑type fullerene derivative suppresses primary effusion lymphoma cell viability via the downregulation of the Wnt signaling pathway through the destabilization of β‑catenin

Primary effusion lymphoma (PEL) is defined as a rare subtype of non-Hodgkin's B cell lymphoma, which is caused by Kaposi's sarcoma-associated herpesvirus (KSHV) in immunosuppressed patients. PEL is an aggressive type of lymphoma and is frequently resistant to conventional chemotherapeutics. Therefore, the discovery of novel drug candidates for the treatment of PEL is of utmost importance. In order to discover potential novel anti-tumor compounds against PEL, the authors previously developed a pyrrolidinium-type fullerene derivative, 1,1,1′,1′-tetramethyl [60]fullerenodipyrrolidinium diiodide (derivative #1), which induced the apoptosis of PEL cells via caspase-9 activation. In the present study, the growth inhibitory effects of pyrrolidinium-type (derivatives #1 and #2), pyridinium-type (derivatives #3 and #5 to #9) and anilinium-type fullerene derivatives (derivative #4) against PEL cells were evaluated. This analysis revealed a pyridinium-type derivative (derivative #5; 3- 5′-(etho-xycarbonyl)-1′,5′-dihydro-2′H-[5,6]fullereno-C₆₀-I_h-[1,9-c]pyrrol-2′-yl]-1-methylpyridinium iodide), which exhibited antitumor activity against PEL cells via the downregulation of Wnt/β-catenin signaling. Derivative #5 suppressed the viability of KSHV-infected PEL cells compared with KSHV-uninfected B-lymphoma cells. Furthermore, derivative #5 induced the destabilization of β-catenin and suppressed β-catenin-TCF4 transcriptional activity in PEL cells. It is known that the constitutive activation of Wnt/β-catenin signaling is essential for the growth of KSHV-infected cells. The Wnt/β-catenin activation in KSHV-infected cells is mediated by KSHV latency-associated nuclear antigen (LANA). The data demonstrated that derivative #5 increased β-catenin phosphorylation, which resulted in β-catenin polyubiquitination and subsequent degradation. Thus, derivative #5 overcame LANA-mediated β-catenin stabilization. Furthermore, the administration of derivative #5 suppressed the development of PEL cells in the ascites of SCID mice with tumor xenografts derived from PEL cells. On the whole, these findings provide evidence that the pyridinium-type fullerene derivative #5 exhibits antitumor activity against PEL cells in vitro and in vivo. Thus, derivative #5 may be utilized as a novel therapeutic agent for the treatment of PEL.

Capsaicin Induces ATF4 Translation with Upregulation of CHOP, GADD34 and PUMA

Primary Effusion Lymphoma (PEL) is a rare and aggressive B-lymphoma caused by Kaposi's sarcoma-associated herpes virus (KSHV) infection that occurs in immunocompromised patients. PEL patients have a poor prognosis. KSHV modulates various cellular signaling pathways to maintain latent infection, and causes malignant conversion of host cells. We previously reported that capsaicin suppressed extracellular signal-regulated kinase (ERK) and p38 mitogen-activated protein kinase (MAPK) signaling and induced apoptosis in PEL. Generally, cellular stress such as nutrient starvation, oxidation and virus infection induce CCAAT/enhancer binding protein (C/EBP) homologous protein (CHOP) expression by activating transcription factor 4 (ATF4), however endoplasmic reticulum (ER) stress induces CHOP expression by both ATF4 and ATF6. CHOP is associated with apoptosis induction and upregulates growth arrest and DNA damage-inducible protein 34 (GADD34) and p53 up-regulated modulator of apoptosis (PUMA) mRNA expression. In this study, we found a new mechanism in which capsaicin induces apoptosis via ATF4-CHOP-PUMA. Capsaicin promoted transcriptional activation of CHOP, which increased mRNA expression of GADD34 and PUMA, resulting in PEL apoptosis. Furthermore, capsaicin increased ATF4 protein levels by promoting ATF4 translation, not transcription, and had no effect on ATF6-dependent transcriptional activation. In sum, capsaicin promotes ATF4 translation and transcriptional induction of CHOP, which results in PUMA expression and apoptosis in PEL cells.

Safety and efficacy of PD-1/PD-L1 blockade in patients with preexisting antinuclear antibodies

PURPOSE

Immune checkpoint inhibitors (ICIs) show promising clinical activity in advanced cancers. However, the safety and efficacy of PD-1/PD-L1 blockade in patients with preexisting antinuclear antibodies (ANA) are unclear.

METHODS

191 patients treated with nivolumab, pembrolizumab, atezolizumab, or durvalumab for unresectable advanced cancers between September 2014 and December 2018 were identified retrospectively. Patients were divided into positive (ANA titers ≥ 1:160) and negative ANA groups (ANA titers < 1:160). Development of immune-related adverse events (irAEs), the overall response rate (ORR), and disease control rate (DCR) were monitored.

RESULTS

Positive ANA titers were seen in 9 out of 191 patients. Four patients in the positive ANA group and 69 patients in the negative group developed irAEs of any grade without a significant difference between the groups. The development of endocrine, pulmonary, and cutaneous irAEs was not significant, whereas positive ANA was significantly higher in patients who developed colitis (2/9) than in patients who did not (3/182, P = 0.0002). DCR in the positive and negative ANA group was 37.5% and 67.5%, respectively, and was not statistically significant, but had better efficacy in patients without ANA (P = 0.08). ANA-related autoimmune diseases such as SLE, Sjögren's syndrome, MCTD, scleroderma, dermatomyositis, and polymyositis was not induced in either group. However, one patient with preexisting dermatomyositis had a flare up after initiation of atezolizumab.

CONCLUSION

Further studies to identify predictive factors for the development of irAEs are required to provide relevant patient care and maximize the therapeutic benefits of ICIs.

Capsaicin Induces Apoptosis in KSHV-Positive Primary Effusion Lymphoma by Suppressing ERK and p38 MAPK Signaling and IL-6 Expression

Primary effusion lymphoma (PEL) is defined as a rare subtype of non-Hodgkin's B-cell lymphoma which is caused by Kaposi's sarcoma-associated herpesvirus (KSHV) in immunosuppressed patients. PEL is an aggressive lymphoma and is frequently resistant to conventional chemotherapies. Therefore, it is critical to investigate novel therapeutic options for PEL. Capsaicin is a pungent component of chili pepper and possesses unique pharmacological effects, such as pain relief, anti-microbial and anti-cancer properties. Here, we demonstrate that capsaicin markedly inhibited the growth of KSHV latently infected PEL cells by inhibiting ERK, p38 MAPK and expression hIL-6, which are known to contribute to PEL growth and survival. The underlying mechanism of action by capsaicin was through the inhibition of ERK and p38 MAPK phosphorylation and signaling that affected hIL-6 expression. As a result, capsaicin induced apoptosis in PEL cells in a caspase-9 dependent manner. In line with these results, ERK (U0126) and p38 MAPK (SB203580) specific signaling inhibitors suppressed hIL-6 expression and attenuated cell growth in PEL cells. Furthermore, the addition of hIL-6 neutralizing antibody to culture medium suppressed the growth of PEL cells. We also demonstrate that capsaicin suppressed PEL cell growth in the absence of nascent viral replication. Finally, we confirmed ex vivo treatment of capsaicin attenuated PEL development in SCID mice. Taken together, capsaicin could represent a lead compound for PEL therapy without the risk of de novo KSHV infection.

A predictive factor of insufficient liver regeneration after preoperative portal vein embolization

BACKGROUND

Preoperative portal vein embolization (PVE) is performed to enhance the future remnant liver function (FRLF) and volume (FRLV). However, the volume of the nonembolized liver does not increase enough in some patients, which results in an insufficient FRLF. The aim of this study was to evaluate the predictors of insufficient FRLF after PVE for extended hepatectomy.

METHODS

This retrospective study included 172 patients (107 patients with cholangiocarcinoma, 40 patients with metastatic liver cancer and 25 patients with hepatocellular carcinoma) who underwent PVE before extended hepatectomy. The total liver function was evaluated by measuring the indocyanine green plasma clearance rate (KICG). Computed tomography volumetry was conducted to evaluate the total liver volume and FRLV. The KICG of the future remnant liver (remK) was calculated using the following formula: KICG × FRLV/total liver volume. The safety margin for hepatectomy was set at remK after PVE (post-PVE remK) ≥ 0.05.

RESULTS

One hundred and twenty-three patients with a post-PVE remK level of >0.05 underwent hepatectomy without postoperative liver failure [sufficient liver regeneration (SLR) group], and 9 patients with a post-PVE remK level of <0.05 did not due to insufficient FRLF [insufficient liver regeneration (ILR) group]. In the SLR group, the KICG values did not change after PVE (median, 0.144-0.146, p = 0.523); however, the %FRLV and remK increased significantly (35.0-44.3%, p < 0.001 and 0.0488-0.0610, p < 0001, respectively). In contrast, in the ILR group, the KICG values decreased significantly (0.128-0.108, p = 0.021) and the %FRLV increased marginally (27.4-32.6%, p = 0.051). As a result, the remK did not increase significantly (0.0351-0.0365, p = 0.213). A receiver operating characteristic curve demonstrated an remK value of 0.04 obtained before PVE (pre-PVE remK) to be the optimal cutoff point for defective liver regeneration. The univariate and multivariate analyses revealed that a pre-PVE remK value of <0.04 was a factor for ILR. It was also correlated with postoperative liver failure in the analysis of the patients who underwent hepatectomy.

CONCLUSIONS

The patients in the ILR group did not achieve SLR after PVE due to a significant decrease in the KICG and an insufficient increase in %FRLV. A pre-PVE remK value of <0.04 is a useful predictor of insufficient regeneration of the nonembolized liver, even after PVE.

Criteria for drain removal following liver resection

BACKGROUND

Abdominal drains have been placed prophylactically and removed in liver resection without robust evidence. The present study was designed to establish the optimal time for removal of such drains.

METHODS

Data on abdominal prophylactic drains were analysed in a consecutive series of patients who underwent liver resection for malignancy between 2006 and 2009. Bilirubin levels in drain fluid were measured and bacteriological cultures were taken on days 1, 3, 5 and 7 after surgery. Drains were removed on day 3 if the drain-fluid bilirubin level was less than 5 mg/dl and bacteriological cultures were negative. Drains remained in situ until these conditions were met.

RESULTS

A total of 514 abdominal drains were placed in 316 patients operated on in the study period. Fifty-eight patients (18·4 per cent) had positive drain-fluid cultures and 14 (4·4 per cent) had bile leakage (drain-fluid bilirubin level 5 mg/dl or more). Only one patient required ultrasound-guided abdominal drainage. On multivariable analysis, drain-fluid bilirubin level on day 3 after surgery was the strongest predictor of infection (odds ratio 15·11, 95 per cent confidence interval 3·04 to 92·11; P < 0·001). The area under the receiver operating characteristic curve on day 3 had the highest predictive value: 83·6 per cent accuracy and 3·9 per cent false-positive rate for a drain-fluid bilirubin level of 3·01 mg/dl (51·5 µmol/l).

CONCLUSION

The '3 × 3 rule' (drain-fluid bilirubin level below 3 mg/dl on day 3 after operation) is an accurate criterion for removal of prophylactically placed abdominal drains in liver resection.

Immune recovery after autologous PBSC transplantation without in vitro graft manipulation for refractory systemic lupus erythematosus

Autologous hematopoietic SCT (ASCT) has been investigated as salvage therapy for refractory systemic lupus erythematosus (SLE). Although immune recovery after ASCT with in vitro purging of lymphocytes has been extensively studied, little information is available about immune recovery after ASCT without in vitro purging. Therefore, we analyzed the immune recovery of a patient who successfully underwent ASCT without in vitro purging for refractory SLE. In addition to the numbers of PBL subsets, T-cell receptor rearrangement excision circles (TRECs) and the T-cell receptor repertoire diversity of both CD4+ and CD8+ T cells were sequentially analyzed. All SLE-related symptoms disappeared within 3 months after ASCT and the serum anti-dsDNA Ab became undetectable. The number of CD4+CD45RO+ memory T cells remained lower than that in healthy adult controls, but the number of CD4+CD45RA+ naïve T cells showed a rapid increase after ASCT. TRECs of both CD4+ and CD8+ T cells were strongly suppressed before ASCT, but consistently increased after ASCT. The T-cell receptor repertoire of CD8+ T cells was skewed before ASCT, but the diversity recovered after ASCT. ASCT with the reinfusion of a large number of autologous T cells did not impair the recovery of naive T cells or resetting of the immune system.

Isolation of cis-3-Amino-l-Proline from Cultured Mycelia of Morchella esculenta Fr

cis-3-Amino-l-proline, identified once as a nonprotein amino acid from the fruiting bodies of Morchella esculenta Fr., was isolated also from the growth medium and cultured mycelia of the same fungus.

A green tea polyphenol, epigalocatechin-3-gallate, induces apoptosis of human hepatocellular carcinoma, possibly through inhibition of Bcl-2 family proteins

BACKGROUND/AIMS

A major polyphenol of green tea, epigallocatechin-3-gallate (EGCG), has previously been shown to induce cell-cycle arrest and apoptosis in various cancers. However, little is known about its effects on hepatocellular carcinomas (HCCs).

METHODS

Four HCC cell lines, HLE, HepG2, HuH-7 and PLC/PRF/5, were treated with EGCG or vehicle. Cell viability was assessed by trypan blue staining and WST-8 assay. Cell-cycle, apoptosis and apoptosis-related proteins in HLE cells were evaluated by flow cytometry and Western blotting. The effect of EGCG was also studied in vivo using a xenograft model. The effect of co-treatment with EGCG and tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) was also assessed.

RESULTS

EGCG inhibited the growth of all HCC cell lines at concentrations of 50-100 microg/ml. In HLE cells, EGCG induced apoptosis but not cell-cycle arrest and appears to have down-regulated Bcl-2alpha and Bcl-xl by inactivation of NF-kappaB. Oral administration of EGCG showed similar effects in HLE xenograft tumors. Co-treatment with EGCG and TRAIL synergistically induced apoptosis in HLE cells.

CONCLUSIONS

EGCG induced apoptosis in HLE cells, both in vitro and in vivo. Moreover, it enhanced TRAIL-induced apoptosis. Therefore, EGCG treatment may be useful for improving the prognosis of HCCs.

Determination of probability distribution of diplotype configuration (diplotype distribution) for each subject from genotypic data using the EM algorithm

Haplotype analysis is important for mapping traits. Recently, methods for estimating haplotype frequencies from genotypes of unrelated individuals based on the expectation-maximization (EM) algorithm have been developed. Our program estimates haplotype frequencies in the population and determines the posterior probability distribution of diplotype configuration (diplotype distribution) for each subject based on the estimated haplotype frequencies. Samples from three ethnic groups for the smoothelin gene (SMTN) and those from three Japanese groups for serum amyloid A genes (SAA@) were analyzed. The estimated diplotype distribution for each individual was concentrated, in most cases, in a single diplotype configuration. The diplotype configuration thus determined was the same as that determined in in vitro experiments, with one exception. Thus, the diplotype configurations determined using the estimated haplotype frequencies from unrelated individuals are reliable. Using this method, the risk of a subject developing a phenotype may be estimated from the diplotype distribution when the phenotype is associated with diplotype configurations.

Clinical usefulness of the atrial double potential at the intercaval region in the right atrium: a new index for inducibility of atrial fibrillation in electrophysiologic studies

The second deflection of the atrial double potential (DP) recorded at the intercaval region is considered to reflect the far-field potential of the left atrium. The conduction via the upper interatrial connection was evaluated utilizing this DP and the relationship between atrial fibrillation (AF) and the conduction via the interatrial connection evaluated. In 30 consecutive patients with the DP at the intercaval region, prolongation in the left atrial activation time during the right atrial extra stimulation was measured at the intercaval region (deltaDP) and the coronary sinus (deltaCS). The difference between deltaDP and deltaCS (deltaDP-deltaCS) was used as an index of inhomogeneity in interatrial conduction. The patients were divided into AF (n=13) and non-AF (n=17) groups in accordance with the inducibility of AF in the electrophysiologic study. The max deltaDP and the max ACS were greater in the AF group than in the non-AF group, i.e., max deltaDP (43+/-19 vs 27+/-17 ms, P=0.021), max deltaCS (35+/-15 vs 21+/-14 ms, P=0.029). The max absolute value(deltaDP-deltaCS) was also greater in t

Effect of procainamide on the postrepolarization refractoriness in cardiac muscle: evaluation using the block coupling interval in the artificial isthmus model in the canine right atrium

The post-repolarization refractoriness (PRR) is an important factor to determine the conduction block in cardiac muscle. Recently, we proposed the block coupling interval (BCI) as an useful electrophysiological index for evaluating the PRR. In the present study, the effect of procainamide on PRR was evaluated using the BCI and the effective refractory period (ERP). In five beagle dogs, radiofrequency linear ablation was performed on the right atrial surface parallel to the AV groove, forming an artificial isthmus (8-10 mm width and 15-20 mm length). Bipolar recordings were performed in the isthmus at a resolution of 1.2 mm and single extrastimuli with eight basic drive trains were delivered to cause conduction blocks in the isthmus. When a conduction block occurred, the recorded coupling interval at the recording site just proximal to the site of block was defined as BCI. At the site of the block, the ERP and duration of the monophasic action potential (MAP) at each drive cycle length was measured. The PRR was calculated using two different formulas: (1) [ERP-MAP] and (2) [BCI-MAP]. Procainamide was administrated intravenously at a dose of 15 mg/kg after the control study and the whole study protocol was repeated. The site of the block in an individual dog was always the same. BCI, ERP, and MAP were all shortened in accordance with the shortening of the basic drive cycle length, and the BCI was always the longest, ERP the middle, and the MAP was the shortest. The administration of procainamide prolonged each parameter, but the order of BCI > ERP > MAP remained unchanged. The PRR calculated as [BCI-MAP] was prolonged from 15 +/- 10 ms to 29 +/- 8 ms by the administration of procainamide (P = 0.048), but [ERP-MAP] was unchanged (8 +/- 10 ms vs 8 +/- 4 ms). In the conduction block model in the canine right atrium, procainamide prolonged the [BCI-MAP], but did not change the [ERP-MAP]. The procainamide effect of prolonging the PRR might be expressed better by the change in the BCI than the ERP.

A novel single-nucleotide polymorphism at the 5'-flanking region of SAA1 associated with risk of type AA amyloidosis secondary to rheumatoid arthritis

OBJECTIVE

To address whether the gamma haplotype at exon 3 of the SAA1 gene is directly associated with type AA amyloidosis or is merely in linkage with an unknown polymorphism that is primarily associated with disease risk, we examined the SAA1 gene for new polymorphisms.

METHODS

We analyzed DNA samples from 44 rheumatoid arthritis (RA) patients with AA amyloidosis (amyloid group), 55 RA patients without AA amyloidosis (RA group), and 58 non-RA healthy subjects (non-RA group). We also examined DNA samples from 50 Caucasians to compare linkage disequilibrium relationships involving SAA1 region polymorphisms between Japanese and Caucasoid populations.

RESULTS

We observed 3 novel single-nucleotide polymorphisms (SNPs) in the 5'-flanking region of SAA1: -61C/G, -13T/C, and -2G/A. Comparison of allele frequencies and ratios of individuals with particular alleles between the study groups revealed statistically significant differences between the amyloid and RA groups and between the amyloid and non-RA groups. Statistical analysis revealed that the -13T/C SNP was strongly associated with AA amyloidosis. In addition, we found tight linkage between the -13T allele and the alpha haplotype, rather than the beta haplotype, at exon 3 in the Caucasoid population, while -13T was closely linked to the gamma and beta haplotypes, rather than the alpha haplotype, in the Japanese population. Since the linkage disequilibrium relationship was reversed between the Japanese and Caucasoid populations, different exon 3 haplotypes of SAA1 are found to be associated with the risk of AA amyloidosis in different ethnic groups.

CONCLUSION

Our data suggest that the SAA1 -13T allele, rather than SAA1 exon 3 haplotypes, is primarily associated with AA amyloidosis risk.

A prospective study of renal disease in patients with early rheumatoid arthritis

OBJECTIVES

This prospective study was designed to clarify the frequency, causes, and clinical course of renal disease in patients with early rheumatoid arthritis (RA).

METHODS

235 patients (185 women, mean age 49.4 years) with early RA of less than one year's duration were enrolled and assessed monthly. Proteinuria was defined as a positive dipstick result and microscopic haematuria was defined as the presence of > or =5 red blood cells per high power field. Urinary abnormalities lasting three months or longer were defined as persistent abnormalities.

RESULTS

At entry, 40 patients exhibited haematuria, two had a raised serum creatinine concentration, and none had proteinuria. During the observation period (average 42 months), persistent haematuria was found in 43, persistent proteinuria in 17, and a raised serum creatinine concentration in 14 patients. Persistent proteinuria was caused by drugs in 14 of 17 patients and disappeared in most cases. Risk factors for drug induced proteinuria included a raised C reactive protein and erythrocyte sedimentation rate and age over 50 at entry. Drugs resulted in a raised serum creatinine concentration in eight of 14 patients. The incidence of haematuria at entry did not differ among patients who had been treated with non-steroidal anti-inflammatory drugs, disease modifying antirheumatic drugs, or no drugs. In some patients with isolated haematuria, the haematuria appeared when the activity of RA was high and resolved when it was low.

CONCLUSIONS

This study suggests that a raised serum creatinine concentration or persistent proteinuria in patients with early RA is predominantly drug related whereas, in contrast, isolated haematuria is more directly associated with the activity of the disease process.

Inhomogeneity in the appearance of electrical remodeling during chronic rapid atrial pacing: evaluation of the dispersion of atrial effective refractoriness

In the present study, the long-term process of progression of electrical remodeling at various atrial sites, which is not well understood, was compared while monitoring continuously the electrophysiologic parameters at multirecording sites in canine atria during continuous atrial burst pacing. A rapid pacing device was implanted in 5 dogs, and continuous atrial burst pacing (400 beats/min) was delivered at the right atrial appendage (RAA). Four pairs of epicardial wire electrodes were sutured on (1) the RAA, (2) Bachmann's bundle (BB), (3) the right atrium close to the inferior vena cava (IVC), and (4) the left atrium (LA). The distal ends of those wires were exteriorized posteriorly and used for pacing and recording. The atrial effective refractory period (AERP), AERP dispersion (AERPd), atrial conduction time (CT) and inducibility of atrial fibrillation (AF) were evaluated during burst pacing for 14 days and during the subsequent 7 days' recovery. The AERP at the LA pacing site was shorter than that at the other sites on day 0. The AERP shortening was greater in the RAA and LA sites than in the BB and IVC sites. The AERPd increased during pacing and reached the maximum level on day 3, and then decreased during the recovery phase. Prolongation of CT tended to be longer between the RAAand IVC sites than that between the other sites. The incidence of AF induction became higher in accordance with the time course of the rapid pacing phase. There was another peak of AF induction on days 7-10. In a canine chronic rapid atrial stimulation model, the progression of electrical remodeling (ie, the shortening of the AERP and the prolongation of the CT) was not homogeneous in both atria, the AERPd showed a temporal increase between days 3 and 7 and matched the increase in AF inducibility at the LA pacing site, the increase in the AERPd was mainly caused by more rapid AERP shortening at the RAA or LA sites, and the LA site always showed a shorter AERP than the other atrial sites in the control state and during the rapid pacing phase, whereas AF inducibility was higher at the LA site than the other sites.

Leakage of energy to the body surface during defibrillation shock by an implantable cardioverter-defibrillator (ICD) system--experimental evaluation during defibrillation shocks through the right ventricular lead and the subcutaneous active-can in canines

The leakage of electrical current to the body surface during defibrillation shock delivery by an implantable cardioverter-defibrillator (ICD) device (the Medtronic Jewel Plus PCD system) was evaluated in 5 dogs. The defibrillation shocks were delivered between the active-can implanted in the left subclavicular region and the endocardial lead placed in the right ventricle at the energy levels of 1, 2, 8, 12, 24 and 34 J. During each delivery, the electrical current leakage from the body surface was measured by electrodes connected to a circuit at 4 recording positions: (A) parallel-subcutaneous (the electrodes were fixed in the subcutaneous tissue of the left shoulder and the right lower chest, and the direction of the electrode vector was parallel to the direction of the defibrillation energy flow); (B) cross-subcutaneous (the electrodes were fixed in the subcutaneous tissue of the right shoulder and the left lower chest, and the vector of the electrodes was roughly perpendicular to the direction of the energy flow); (C) parallel-surface (the electrodes were fixed with ECG paste on the shaved skin surface at the left shoulder and the right lower chest); and (D) surface grounded (the electrodes were fixed on the shaved skin surface at the left shoulder and the left foot, which was grounded). The circuit resistance was set at a variable level (100-5,000 ohms) in accordance with the resistance measured through each canine body. Leakage energies were measured in 750 defibrillation shocks with each circuit resistance in 5 dogs. The leakage energy increased in accordance with the increase of the delivered energy and the decrease of the circuit resistance in all 4 recording positions. When the circuit resistance was set at 1,000 ohms, the leakage energy during shock delivery at 34 J was 32+/-17 mJ at position A, 5+/-9 mJ at B, 10+/-9 mJ at C, and 4+/-3 mJ at D (p=0.042). The peak current was highest at position A and was 87+/-22 mA with a circuit resistance of 1,000 ohms. The power of the leakage energy depended on the delivered energy and the impedance between the electrodes. The angle between the alignment of the recording electrodes and the direction of the energy flow was another important factor in determining the leakage energy. Although the peak current of the leakage energy reached the level of macro shock, the highest leakage energy from the body surface was considerably less because of the short duration of the shock delivery.

Evaluation of post-repolarization refractoriness for conduction block in cardiac muscle: studies in an artificial isthmus in the canine right atrium

Post-repolarization refractoriness (PRR) is an important factor in determining conduction block and is the difference between the effective refractory period (ERP) and the duration of the monophasic action potential (MAPD). In the present study, conduction block in an artificial isthmus in the canine atrium was evaluated and the coupling interval of a premature beat, which caused the block, was defined as the block coupling interval (BCI). The usefulness of this value was also evaluated. Radiofrequency linear ablation was performed on the right atrial surface parallel to the atrioventricular groove in 5 mongrel dogs, and an artificial isthmus (8-10mm wide and 25-30mm long) was created. Fourteen simultaneous unipolar recordings were performed in the isthmus with a resolution of 1.2 mm. Single extra-stimuli with basic drive train were delivered to induce conduction block in the isthmus and when it occurred, the coupling interval at the recording site just proximal to the site of the block was defined as the BCI. At the site of the block, the ERP and MAPD at each drive cycle length were measured. The PRR was calculated using 2 different formulae: (1) [ERP-MAPD], and (2) [BCI-MAPD]. It was found that each value was shortened in accordance with the shortening of the basic drive cycle length. In all basic drive trains, BCI>ERP>MAPD, and [ERP-MAPD] was always shorter than [BCI-MAPD]. In the shorter cycle length of basic drives, the difference between [ERP-MAPD] and [BCI-MAPD] was more prominent. In the artificial isthmus model in the canine atrium, BCI was always longer than the ERP measured at the same site as the block. Because the ERP may not directly reflect the block phenomenon, the electrophysiologic evaluation should use the BCI instead, as in the PRR evaluation.

Isolation of a Thermophilic Poly-L-Lactide Degrading Bacterium from Compost and Its Enzymatic Characterization

Thermophilic poly-L-lactide-degrading bacteria were isolated from a garbage fermentor. One of the isolates, strain PL21, was identified as Bacillus smithii based on its physiological properties, sugar assimilation pattern, and partial 16S rDNA sequence. The degradation activity of poly-L-lactide exibited by the culture fluid was parallel to the esterase activity, and the purified enzyme was active against various fatty acid esters and poly-L-lactide, at 60 degrees C and pH 5.

Purification and characterization of nitrite-oxidizing enzyme from heterotrophic Bacillus badius 1-73, with special concern to catalase

Nitrite-oxidizing enzyme I (NiOx I) was purified from a heterotrophic bacterium, Bacillus badius I-73. The enzyme was a homotetramer of a heme-containing peptide, and was similar to catalases from various sources in its N-terminal amino acid sequence. The purified enzyme also catalyzed H2O2 degradation. The nitrite oxidation reaction required ascorbic acid and oxygen. Successive H2O2 feeding could be substituted for ascorbic acid. These indicated that NiOx I is a catalase and nitrite was oxidized by a peroxidase-like reaction.

Quantitative evaluation of a directly depolarized area induced by high-output pacing on the cardiac muscle

Quantitative information is needed on the directly depolarized area (DDA) induced by high-output energy during a precise mapping procedure to detect the origin of a tachycardia. In the present study, a DDA caused by high-output energy was quantitatively evaluated in the exposed canine heart. In 8 dogs, the right atrial and ventricular surfaces were exposed through a right thoracotomy and pacing with various outputs was delivered from the epicardial surface. A comb-shaped 16 polar electrode array and/or a 224 polar mat electrode array were used for recording the epicardial electrograms. The local activation time was measured at each electrode site, and the relationship of the distance between the electrode location from the pacing site and the local activation time was plotted and fitted to a primary regression line. The intercept of the regression line on the horizontal axis was defined as the radius of the 'DDA' and this was evaluated at each pacing output. The radius of the DDA was 0.6+/-0.1 mm with a 2 V and 3.8+/-0.2 mm with a 10 V output when it was evaluated in a direction perpendicular to the fiber orientation of the pectinate muscle, 0.8+/-0.1 mm with a 2 V and 4.1+/-0.3 mm with a 10 V output in a direction parallel to the pectinate muscle fiber orientation, and 0.9+/-0.3 mm with a 2 V and 3.6+/-0.5 mm with a 10 V output in the right ventricle. The DDA extended according to the increase in stimulation outputs at all sites, and there was no significant difference in the pacing site or the direction of the stimulation propagation. The DDA caused by high-output energy is a purely physical phenomenon that depends only on stimulation output and tissue resistance. The diameter of the DDA exceeded 4 mm (ie, the size of a standard tip electrode for catheter ablation) when pacing was delivered with an output greater than 6 V.

Transient appearance of antegrade conduction via an AV accessory pathway caused by atrial fibrillation in a patient with intermittent Wolff-Parkinson-White syndrome

A 55 year old man with intermittent Wolff-Parkinson-White (WPW) syndrome had an episode of atrial fibrillation (AF) that lasted for 117 days. After interruption of the AF a Delta wave appeared that lasted for two days and then disappeared. Exercise stress and isoprenaline infusion could not reproduce the Delta wave, but after another episode of AF which lasted for seven days a persistent Delta wave appeared that lasted for six hours. In an electrophysiological study performed on a day without a Delta wave, neither antegrade nor retrograde conduction via an accessory pathway was seen, but after atrial burst pacing (at 250 ms cycle length) for 10 minutes, a Delta wave appeared lasting for 16 seconds. Atrial electrical remodelling-that is, the shortening of the atrial effective refractory period caused by AF, is a possible mechanism of the appearance of the Delta wave.

Role of conserved histidine residues in D-aminoacylase from Alcaligenes xylosoxydans subsp. xylosoxydans A-6

D-Aminoacylase from Alcaligenes xylosoxydans subsp. xylosoxydans A-6 (Alcaligenes A-6) was strongly inactivated by diethylpyrocarbonate (DEPC). An H67N mutant was barely active, with a kcat/Km 6.3 x 10(4) times lower than that of the recombinant wild-type enzyme, while the H67I mutant lost detectable activity. The H67N mutant had almost constant Km, but greatly decreased kcat. These results suggested that His67 is essential to the catalytic event. Both H69N and H69I mutants were overproduced in the insoluble fraction. The kcat/Km of H250N mutant was reduced by a factor of 2.5 x 10(4)-fold as compared with the wild-type enzyme. No significant difference between H251N mutant and wild-type enzymes in the Km and kcat was found. The Zn content of H250N mutant was nearly half of that of wild-type enzyme. These results suggest that the His250 residue might be essential to catalysis via Zn binding.

Posteroventral pallidotomy for midbrain tremor after a pontine hemorrhage. Case report

This 49-year-old man gradually developed a disabling action tremor in the proximal right upper extremity 8 months after suffering a pontine tegmental hemorrhage. The intraoperative microrecording in the nucleus ventralis intermedius (VIM) of the left thalamus revealed tremor-synchronous grouped discharges with a vigorous (2.7 Hz) action tremor predominantly in the shoulder and upper arm. High frequency electrical stimulation in the VIM did not affect the tremor. A posteroventral pallidotomy (PVP) was performed and resulted in the successful alleviation of all tremor activity. Posteroventral pallidotomy is known to alleviate parkinsonian tremors, especially those occurring in the contralateral lower extremity, trunk, and proximal segment of the contralateral upper extremity. The authors consider the pallidoreticular pathway to be an important tremor-mediating pathway for the proximal segment of the upper extremities and believe it can be controlled more effectively by PVP than by VIM thalamotomy, as demonstrated by the PVP-induced resolution of the midbrain tremor observed in this case.

Influence of genotypes at SAA1 and SAA2 loci on the development and the length of latent period of secondary AA-amyloidosis in patients with rheumatoid arthritis

To examine whether polymorphism at the SAA loci is associated with the development of amyloid protein A (AA)-amyloidosis, we determined the genotypes at the SAA1 and SAA2 loci in 43 AA-amyloidosis patients (amyloidosis population) and 77 patients with rheumatoid arthritis (RA) who had been ill for less than 5 years (early RA population). We also compared the frequencies of the genotypes at the SAA1 locus among 90 Korean, 95 Taiwanese, and 103 Japanese healthy subjects. The frequencies of the gamma/gamma genotype and gamma alleles at the SAA1 locus were significantly higher in the amyloidosis population than in the early RA population (34.9% versus 7.8%, and 58.1% versus 33.8%, chi2 test P=0.0001). The frequencies of the gamma allele at the SAA1 locus in Koreans, Taiwanese, and Japanese were 41.6%, 35.6%, and 37.4%, respectively. The length of the latent period of AA-amyloidosis was significantly longer in the patients with smaller numbers of the gamma allele at the SAA1 locus (Spearman's correlation coefficient: -0.42, P<0.05). On the other hand, the mean C-reactive protein (CRP) level during 2 years prior to the diagnosis of AA-amyloidosis was significantly higher in the patients with larger numbers of the gamma allele at the SAA1 locus (Spearman's correlation coefficient: 0.34, P<0.05). No significant association was found between amyloidosis and polymorphism at the SAA2 locus. We postulate that the allele SAA1gamma renders an RA patient susceptible to amyloidosis, possibly by affecting the severity of inflammation in RA.

Electrophysiologic parameters to predict clinical recurrence of ventricular tachycardia in patients under electrophysiologic study-guided effective pharmacological therapy

Although an electrophysiologic study (EPS) is the most reliable method for selecting the treatment for a patient with sustained ventricular tachycardia (VT), VT recurrence may occur even during EPS-guided effective therapy. Electrophysiologic parameters were compared between patients with and without arrhythmic events under EPS-guided effective therapy to identify the predictive parameters of VT recurrence during the clinical course. The study population consisted of 77 consecutive patients with sustained VT who were receiving long-term pharmacological therapy that was demonstrated to be effective by the EPS assessment. The VT induction protocol employed 1-3 extrastimuli and rapid ventricular pacing at 2 right ventricular sites and 1 left ventricular site, and isoproterenol was infused when VT was not induced. To determine the 'effective' antiarrhythmic drug, all sustained ventricular arrhythmias had to be prevented during the whole induction protocol, but repetitive ventricular responses (RVR) were allowed to remain for up to 5 beats when they were in the same QRS configurations as the clinical VT and up to 12 beats when they were in polymorphic QRS configurations. The effective refractory periods (ERPs) at the 3 ventricular pacing sites and their difference (i.e., ERP-dispersion) and the maximum number of RVR beats were evaluated in an EPS during the control state and at the time of drug assessment. In the comparison of patients with and without VT recurrence, there was no significant difference in clinical characteristics or ERPs, but the deltaERP-dispersion (i.e., the increase in ERP-dispersion caused by the antiarrhythmic drug) and the maximum number of RVRs were significantly smaller in the group of patients without VT recurrence (deltaERP-dis, -3+/-8 vs. 6+/-12, p = 0.0027; maxRVR, 3+/-3 vs. 5+/-4, p = 0.0160). The VT recurrence rate was significantly lower in the patients with deltaERP-dis < or =0 or maxRVR<6 in comparison with the others (p = 0.01 14 and p = 0.0360). Patients with VT recurrence showed greater deltaERP-disp and a longer duration of RVRs at the time of drug assessment in comparison with the patients without VT recurrence. The prognosis of patients under EPS-guided therapy may be improved by the use of stricter criteria for drug assessment in the EPS, although this may decrease the number of drug responders determined in the EPS.

Importance of retrograde atrial activation in atrial fibrillation genesis in the initiation of atrial fibrillation in Wolff-Parkinson-White syndrome. Comparison of atrial electrophysiologic parameters between patients with different atrial fibrillation genesis (initiation sites) in atria

The changes in the duration of atrial electrograms during different atrial activation sequences from a sinus rhythm were evaluated to test the hypothesis that the prolongation of atrial electrogram duration caused by the different atrial activation sequence is more prominent at the site of atrial fibrillation (Afib) genesis (initiation site) than other areas. In 39 patients with single retrograde left-sided accessory connection who had inducible transient atrial fibrillation during an electrophysiologic study, the site of Afib genesis was determined and classified into three groups, i.e., 1) high right atrial genesis (HRA), 2) low right atrial genesis (LRA), and 3) left atrial genesis (LA). Single premature extrastimuli after 8 basic drive trains (600 ms) were delivered at the HRA and the right ventricular apex. Three atrial electrophysiologic parameters were evaluated at three atrial sites, i.e., 1) HRA, 2) LRA, and 3) coronary sinus. The atrial vulnerability parameters were as follows; 1) %A2/A1: % prolongation of atrial electrogram duration during premature beat (A2) in comparison with basic drive (A1), 2) wavelength index (WLI): calculated as [effective refractory period]/[A2], and 3) retrograde activation index (RAI): calculated as [A1 during retrograde activation; i.e., RVA pacing/[A1 during antegrade activation, i.e., HRA pacing], shown as a percentage. The Afib genesis was HRA in 20, LRA in 12 and LA in 7 patients. At the HRA recording site, %A2/A1 and RAI were the largest and WLI the shortest in the HRA genesis group in comparison with the other two groups. Similarly, at the LRA and LA recording sites, %A2/A1 and RAI were the largest and WLI the shortest in the groups with Afib genesis at these recording sites. In patients with inducible Afib, %A2/A1 and RAI were the highest and WLI the shortest at the atrial recording site close to the site of Afib genesis. Atrial wave prolongation during retrograde atrial activation, possibly the anisotropic conduction, was considered to play a role in initiating Afib as well as a conduction delay during the atrial premature beat.

Overexpression of salt-tolerant glutaminase from Micrococcus luteus K-3 in Escherichia coli and its purification

A high-expression plasmid, pKSGHE3-1, containing the salt-tolerant glutaminase (EC 3.5.1.2) from marine bacterium Micrococcus luteus K-3 was constructed. pKSGHE3-1 was made by inserting the DNA fragment (1.43 kb) containing the structural gene synthesized by polymerase chain reaction into the downstream region of the tac promoter of expression vector pKK223-3. The translational start codon was located 10 bases downstream of the Shine-Dalgarno sequence (AGGA) of pKK223-3. Escherichia coli JM109 transformed with pKSGHE3-1 exhibited more than 190-fold higher glutaminase activity than M. luteus K-3 under optimal culture conditions. The enzyme was purified to homogeneity through three column chromatography steps with a final yield of 17.1%. The recombinant enzyme showed the same enzymatic properties, including salt tolerance, as those of M. luteus K-3. This glutaminase expression system allows the production of sufficient quantities of glutaminase for basic structure-function studies including chemical modification and future X-ray crystallization analysis.

Therapeutic effects of LK 423, a phthalimido-desmuramyl-dipeptide compound, on dextran sulfate sodium-induced colitis in rodents through restoring their interleukin-10 producing capacity

A new phthalimido compound, N-[2-(2-phthalimidoethoxy)acetyl]-L-alanyl-D-glutamic acid (CAS 142489-47-2, LK 423), was examined for its possible activity to modulate levels and species of cytokines in mice carrying a specific inflamed organ. Colonic inflammation was induced in mice by giving 5% dextran sulfate sodium (DSS) solution as drinking water. The capacity of spleen cells obtained from the DSS-inflamed mice to produce interleukin-10 (IL-10) in response to mitogen was significantly reduced when compared with the capacity of spleen cells from intact mice. Treatment of the mice administered DSS by subcutaneous multiple injections with a low dose of LK423 resulted in delaying the progression to full-blown inflammation in the colon. The mitogen-stimulated spleen cells obtained from the LK423-treated mice yielded significantly greater amounts of IL-10 and IL-6 than the untreated DSS group, and the peritoneal cells from the LK423-treated mice produced significantly lower levels of tumor necrosis factor alpha (TNF alpha). Based on this prophylactic effect of LK423 in the murine colitis model, its therapeutic effect was examined in rats in which colitis had been induced by feeding 3% DSS for 12 days. Intracolonic administration of LK423 to these rats for 7 days resulted in diminishing the ulcerative area in the colon. The immunological characteristics of this new compound are discussed from the point of view of its possible application as a therapeutic agent for inflammatory bowel diseases (IBD) and other inflammatory diseases.

Interleukin-10 inducing activity of LK423, a phthalimido-desmuramyldipeptide compound

A new phthalimido compound, N-[2-(2-phthalimidoethoxy)acetyl]-L-alanyl-D-glutamic acid (CAS 142489-47-2, LK423), was examined along with other N-acyl-desmuramyldipeptide compounds for possible immunomodulating activities in cyclophosphamide (Cy)-treated mice. Reverse transcriptase-polymerase chain reaction (RT-PCR) and Northern blot assays demonstrated that multiple subcutaneous injections of LK423 (1 to 50 micrograms/days, for 4 days) into these mice resulted in upregulating interleukin-10 (IL-10) gene expression in the spleen. In contrast to IL-10, expression of interferon-gamma (IFN-gamma) gene was reduced by treating with this compound. The culture supernatant of spleen cells obtained from the mice that had received LK423 injections was found to contain a larger amount of IL-10 protein than in the culture supernatant of the spleen obtained from the mice that received no LK423 injections when tested by enzyme-linked immunosorbent assay (ELISA). Conversely to IL-10, the concentration of IFN-gamma was lower in the culture supernatant from the LK423-treated group than that in the control group. In contrast to this compound, other N-acyl-desmuramyldipeptide derivatives carrying a L-alanyl-D-isoglutamine moiety, and other immunological stimulants showed an activity to augment production of IFN-gamma and reduce the gene expression of IL-10. The immunological activities of this new phthalimido desmuramyldipeptide compound, LK423, are discussed from the point of view of its therapeutic application.

Purification and characterization of three thermostable endochitinases of a noble Bacillus strain, MH-1, isolated from chitin-containing compost

A thermophilic and actinic bacterium strain, MH-1, which produced three different endochitinases in its culture fluid was isolated from chitin-containing compost. The microorganism did not grow in any of the usual media for actinomyces but only in colloidal chitin supplemented with yeast extract and (2, 6-O-dimethyl)-beta-cyclodextrin. Compost extract enhanced its growth. In spite of the formation of branched mycelia, other properties of the strain, such as the formation of endospores, the presence of meso-diaminopimelic acid in the cell wall, the percent G+C of DNA (55%), and the partial 16S ribosomal DNA sequence, indicated that strain MH-1 should belong to the genus Bacillus. Three isoforms of endochitinase (L, M, and S) were purified to homogeneity and characterized from Bacillus sp. strain MH-1. They had different molecular masses (71, 62, and 53 kDa), pIs (5.3, 4.8, and 4.7), and N-terminal amino acid sequences. Chitinases L, M, and S showed relatively high temperature optima (75, 65, and 75 degreesC) and stabilities and showed pH optima in an acidic range (pH 6.5, 5.5, and 5.5, respectively). When reacted with acetylchitohexaose [(GlcNAc)6], chitinases L and S produced (GlcNAc)2 at the highest rate while chitinase M produced (GlcNAc)3 at the highest rate. None of the three chitinases hydrolyzed (GlcNAc)2. Chitinase L produced (GlcNAc)2 and (GlcNAc)3 in most abundance from 66 and 11% partially acetylated chitosan. The p-nitrophenol (pNP)-releasing activity of chitinase L was highest toward pNP-(GlcNAc)2, and those of chitinases M and S were highest toward pNP-(GlcNAc)3. All three enzymes were inert to pNP-GlcNAc. AgCl, HgCl2, and (GlcNAc)2 inhibited the activities of all three enzymes, while MnCl2 and CaCl2 slightly activated all of the enzymes.

[Immunocytochemistry of proteoglycan in dentin and odontoblasts]

To clarify the distribution of proteoglycan (PG) and matrix metalloproteinase-3 (MMP-3) in the molar tooth germ dentin of rats, immunohistochemical investigation was performed using a antibody 2-B-6 specific for chondroitin 4 sulfate (Ch4-S) and dermatan sulfate (DS) of PG, antibody 3-B-3 specific for chondroitin 6 sulfate (Ch6-S) and chondroitin (Ch) of PG and anti-human-MMP3 antibody. 2-B-6 reacted with the predentin and dentinal tubules. However, there were no reactions around the calcification front or in the calcified dentin matrix other than the dentinal tubules. 3-B-3 and anti-MMP3 antibodies reacted with only the predentin. These results showed that PG containing Ch4-S and DS was present in the dentinal tubules, while PG containing Ch4-S, DS, Ch6-S and Ch as well as MMP-3 was present in the predentin. It is suggested that PG of the predentin is degraded by MMP-3 at the calcification front. In undecalcified sections, the reaction of the dentinal tubules with 2-B-6 was localized in electron-dense sites corresponding to the peritubular dentin, suggesting that PG at this site binds to hydroxyapatite. Furthermore, in odontoblasts, the localization of 2-B-6 was noted in secretory granules distributed in the Golgi region and the odontoblastic process. This suggests that PG is transported from the Golgi region to the odontoblastic process in the form of secretory granules. Immunoreactive secretory granules were also noted in the cellular process of the calcified dentin. PG of the peritubular dentin may be secreted by these secretory granules in the process.

Eosinophilic fasciitis complicated with peripheral polyneuropathy

Peripheral polyneuropathy and the complication of eosinophilic fasciitis (EF) is rare; only 2 such cases have been described previously. A 40-year-old woman suffered from swelling of the extremities after strenuous exercise and complained of bilateral paresthesia on the soles of her feet. The diagnosis was EF according to clinical symptoms, peripheral eosinophilia, and histological examination of the fascia. Nerve conduction tests also revealed sensory disturbance as mononeuritis multiplex. After administration of prednisolone, the swelling and tenderness of the extremities improved immediately but the neuropathy lasted for 6 months.

Prediction of effect of interferon on chronic hepatitis C

Clinical, pathological, and virological analysis including hypervariable region-1 of hepatitis C virus (HCV) was performed to predict the effect of interferon (IFN) on 41 patients with chronic hepatitis type C. The low virus load, low frequency of the mutation in the hypervariable region-1 as the change of amino acid and high level of serum aminotransferase make one estimate the good effect of IFN on patients with HCV. Mutation in the hypervariable region-1 of HCV measured by fast assay fluorescence single-stranded conformational polymorphism was more frequent in nonresponders to IFN than responders. The most frequently mutated position was amino acid number 406. This indicates that the specific mutation site might affect the response of IFN.

L-ornithine decarboxylase from Hafnia alvei has a novel L-ornithine oxidase activity

A novel activity producing gamma-aminobutyric acid (GABA) from L-ornithine in the presence of NAD(P)+ was found in the crude extract of L-ornithine-induced Hafnia alvei, in addition to L-ornithine decarboxylase (ODC) activity. The reaction system for the former activity consisted of two enzymes, L-ornithine oxidase (decarboxylating, OOD) and gamma-aminobutyraldehyde (GABL) dehydrogenase (GDH). OOD catalyzed the conversion of L-ornithine into GABL, CO2, NH3, and H2O2 in the presence of O2, and GDH dehydrogenated GABL to GABA in the presence of NAD(P)+. OOD, purified to homogeneity, had a high ODC activity and the activity ratio of ODC to OOD was almost constant throughout the purification (ODC/ OOD=160:1). The molecular mass of the OOD was about 230 kDa, probably consisting of three identical subunits of a 77 kDa peptide, and OOD had an absorption maximum at 420 nm as well as at 278 nm, the specific absorption for an enzyme containing pyridoxal phosphate (PLP). The content of PLP was estimated at about 1 mol per subunit. OOD was specific to L-ornithine, and other L-amino acids and polyamines including putrescine were inert. The enzyme was activated by PLP, but not by pyridoxamine 5'-phosphate, FAD, FMN, or pyrroloquinoline quinone, and it was inactivated by hydrazine, semicarbazide, and hydroxylamine. The holoenzyme can be resolved to the apoenzyme by incubation with hydroxylamine, and reconstituted with PLP. These properties of OOD were almost the same as those of ODC separately purified to homogeneity from H. alvei. Zn2+ and Cu2+, butanedione, and sodium borohydride inhibited both OOD and ODC in a similar manner. The OOD reaction required O2 and only the ODC reaction proceeded under anaerobic conditions. The substitution of air for oxygen in the reaction vessel and the addition of catalase-H2O, enhanced only the OOD reaction, resulting in an increase of the ratio of OOD/ODC to 1:30 and 1:4.1, respectively. These results suggested that OOD and ODC are identical and that the former is a side reaction of the latter in the presence of O2.

[Cyclophosphamide pulse therapy for refractory rheumatic diseases]

We studied the efficacy of cyclophosphamide pulse therapy (CYP) for refractory rheumatic diseases except for lupus nephritis. Thirty-five patients were included in all, that is 9 patients with systemic lupus erythematosus (SLE), 10 with rheumatoid arthritis (RA), 7 with polymyositis/dermatomyositis (PM/DM), 2 with progressive systemic sclerosis (PSS), 2 with anti-phospholipid antibody syndrome (APS), 1 with mixed connective tissue disease (MCTD), 1 with juvenile rheumatoid arthritis (JRA), 1 with Behcet's disease (BD), 1 with Wegener's granulomatosis (WG) and 1 with allergic granulomatous angiitis (AGA). Moderate to marked improvement was noted in 4 patients with SLE (2 with CNS-lupus and 2 with vasculitis), 7 with RA (2 with interstitial pneumonia:IP, 2 with vasculitis and 2 with refractory arthritis), 4 with PM/DM (2 with IP and 2 with refractory myositis), 1 PSS with IP, 2 APS with thrombocytopenia, 1 JRA with vasculitis and BD with CNS disturbance. On the other hand, adverse reactions were observed in 9 out of 35 patients (25.8%). CYP should apply in the treatment for such refractory rheumatic diseases as CNS disturbance, vasculitis, IP and autoimmune thrombocytopenia.

[A case of systemic sclerosis associated with interstitial pneumonia with various autoantibodies: improvement by intravenous cyclophosphamide therapy]

A 41-year-old woman was admitted to Tokyo Women's Medical College Aoyama Hospital in January 1994. She presented cough and dyspnea in September 1991. The diagnosis of interstitial pneumonia was made based on TBLB. Interstitial pneumonia was responsive to initial prednisolone of 40 mg daily. When dose of prednisolone was reduced to 15 mg daily, she complained of cough and dyspnea again. She was referred to Institute of Rheumatology, Tokyo Women's Maedical College in November 1993. She was diagnosed as systemic sclerosis associated with interstitial pneumonia based on proximal scleroderma and digital pitting scar. Double immunodiffusion and immunoprecipitation assay revealed the presence of anti-Ki, anti-Wa, and anti-RNA polymerases antibodies in the serum. On admission in March 1994, she was treated with intravenous cyclophosphamide therapy at 500 mg/day once a mouth. After the third infusion, respiratory symptoms, pulmonary function test values, findings of chest X-ray and CT scan were improved without adverse drug effects. Intravenous cyclophosphamide therapy seems to be useful in this case. The efficacy of Intravenous cyclophosphamide therapy in the treatment of the interstitial pneumonia associated with systemic sclerosis was discussed.

Intravenous immunoglobulin therapy for refractory myositis

The efficacy of polyvalent intravenous immunoglobulin therapy (IVIG) was evaluated in three patients with refractory myositis. Patients refractory to conventional therapy, such as corticosteroid administration, corticosteroid or cyclophosphamide pulse therapy [2 with dermatomyositis (DM), 1 with polymyositis (PM)] were treated with IVIG (0.4 g/kg daily) for 5 days. Clinical improvement was apparent within 1-2 months after IVIG and persisted for 19-23 months (DM patients) and 12 months (PM patient). No adverse effects were observed. Thus, IVIG may be considered an effective therapy for refractory myositis.

Overproduction of D-aminoacylase from Alcaligenes xylosoxydans subsp. xylosoxydans A-6 in Escherichia coli and its purification

We constructed the high-expression plasmid for D-aminoacylase from Alcaligenes xylosoxydans subsp. xylosoxydans A-6. The appropriate Shine-Dalgarno sequence (AAGGAG) was introduced to the eight bases upstream of start codon (ATG) of D-aminoacylase structural gene by site-directed mutagenesis, and then the 1.75-kb DNA fragment including the open reading frame was inserted into the downstream of the tac promoter of plasmid vector pKK223-3. The resultant plasmid, which was named pKNSD2, showed a high D-aminoacylase activity in Escherichia coli JM109 cells transformed with it. The enzyme was purified to homogeneity in only two steps with a final yield of 24% (sp act, 2023 U/mg).