Cycloimidamicins, Novel natural lead compounds for translation inhibition in Pseudomonas aeruginosa

Pseudomonas aeruginosa is one of the most concerning pathogenic bacteria. We screened antibiotics using a highly drug-sensitive P. aeruginosa strain and an oligotrophic medium, and successfully isolated novel antibiotics, namely cycloimidamicins (CIMs), from a rare actinomycete strain, Lentzea sp. MM249-143F7. X-ray and nuclear magnetic resonance analyses revealed that CIMs possess a distinctive and unprecedented molecular structure, containing tetramic acid and an imidazole ring bound directly to indolone. The CIMs exhibited potent antibacterial activity against Gram-negative bacteria, as well as translation inhibition in Escherichia coli in both intact cells and in vitro. Additionally, E. coli strains resistant to known translation inhibitors did not exhibit cross-resistance to CIMs, suggesting that CIMs inhibit bacterial growth by blocking translation through a novel mechanism.

Sealutomicins, new enediyne antibiotics from the deep-sea actinomycete Nonomuraea sp. MM565M-173N2

A Nonomuraea sp. strain MM565M-173N2 was isolated from deep-sea sediment off the Sanriku coast, and new antibiotics were evaluated against carbapenem-resistant Enterobacteriaceae (CRE), which is a problematic group of bacteria because of their antimicrobial resistance. From 220 l of fermented broth from strain MM565M-173N2, we isolated four new antibiotics by gel filtration and HPLC, designated as sealutomicins A (1.8 mg), B (1.5 mg), C (0.8 mg), and D (0.8 mg). Their structures were determined from MS, NMR, and CD spectra. Sealutomicin A was found to be a new enediyne antibiotic, while sealutomicins B-D were aromatized products from sealutomicin A. Sealutomicin A showed strong antibacterial activity (MIC 0.05-0.2 μg ml^-1) against CRE.

Primary Lymphangiosarcoma of the Urinary Bladder in a Dog

Abdominal ultrasonographical and computed tomography examinations of a 12-year-old neutered female toy poodle revealed a protruding mass, approximately 2 cm in diameter, at the apex of the bladder. The mass was firm and haemorrhagic with a homogeneously brownish-yellow cut surface. Microscopically, it was unencapsulated and located in the muscle layer with invasion of the extra-muscular layer. It was composed of spindloid to oval neoplastic cells that formed irregular clefts and diffuse sheets that dissected bundles of collagen. Immunohistochemically, the neoplastic cells were positive for vimentin and lymphatic vessel endothelial hyaluronan receptor 1 antigens, but negative for cytokeratin AE1/AE3, factor VIII-related antigen, CD31, CD34, Prox-1, S100, desmin, α-smooth muscle actin and MyoD1. Negative immunolabelling for laminin antigen supported the absence of evidence of a basal lamina on ultrastructural examination. Based on these findings, this tumour was identified as a lymphangiosarcoma. To the best of our knowledge, this case is the first report of lymphangiosarcoma arising from the bladder in a dog.

Association between dexamethasone treatment and alterations in serum concentrations of trace metals

Previously, a significant elevation in the serum levels of iron (Fe) was observed within a few days after the initiation of cisplatin (CDDP)-based chemotherapy. To clarify the underlying mechanisms, the serum concentration of hepcidin, a negative regulator of Fe release, was determined in the clinical samples obtained from six patients with cancer. The result showed that the serum concentration of hepcidin in patients receiving CDDP-based chemotherapy was significantly increased after 4-6 days of treatment, in comparison to the baseline level, suggesting that aforementioned excessive systemic Fe was not explained by the change of serum hepcidin level. All these patients received antiemetic premedication. We next evaluated of the effects of Pt-containing drugs and prophylactic antiemetic dexamethasone medication on the serum concentration of trace metals in mice, and on the hepatic and renal concentration of trace metals. The serum concentrations of Fe, Cu, and Zn in the CDDP-treated and oxaliplatin-treated mice were not significantly altered in comparison to those of the vehicle-treated control group. The serum concentrations of Fe, Cu, and Zn were increased after 24 h of dexamethasone treatment, compared to those of the control group (P < 0.05). The hepatic concentration of Mn was significantly reduced, whereas those of Fe and Cu inclined to diminish. The present findings suggest that dexamethasone can partly contribute to the changes in the serum concentrations of trace metals during anticancer chemotherapy.

Semisynthesis of an Anticancer DPAGT1 Inhibitor from a Muraymycin Biosynthetic Intermediate

We have explored a method to convert a muraymycin biosynthetic intermediate 3 to an anticancer drug lead 2 for in vivo and thorough preclinical studies. Cu(OAc)2 forms a stable complex with the amide 4 and prevents electrophilic reactions at the 2-((3-aminopropyl)amino)acetamide moiety. Under the present conditions, the desired 5″-primary amine was selectively protected with (Boc)2O to yield 6. The intermediate 6 was converted to 2 in two steps with 90% yield.

Instability of the 16S rRNA methyltransferase-encoding npmA gene: why have bacterial cells possessing npmA not spread despite their high and broad resistance to aminoglycosides?

The NpmA bacterial 16S rRNA methyltransferase, which is identified from Escherichia coli strains, confers high resistance to many types of aminoglycoside upon its host cells. But despite its resistance-conferring ability, only two cases of its isolation from E. coli (14 years apart) have been reported to date. Here, we investigated the effect of the npmA gene on aminoglycoside resistance in Pseudomonas aeruginosa and Klebsiella pneumoniae and its stability in E. coli cells by comparing it with armA, another 16S rRNA methyltransferase gene currently spreading globally. As a result, we found that npmA conferred resistance to all types of aminoglycoside antibiotics we tested (except streptomycin) in both P. aeruginosa and K. pneumoniae, as well in E. coli. In addition, co-expression of armA and npmA resulted in an additive effect for the resistance. However, in return for the resistance, we also observed that the growth rates and the cell survivability of the strains transformed with the npmA-harboring plasmids were inferior than those of the control strains and that these plasmids were easily disrupted by IS10, IS1, and IS5 insertion sequences. We discuss these data in the context of the threat posed by pathogenic strains possessing npmA.

New antituberculous drugs derived from natural products: current perspectives and issues in antituberculous drug development

Tuberculosis is one of the most common and challenging infectious diseases worldwide. Especially, the lack of effective chemotherapeutic drugs for tuberculosis/human immunodeficiency virus co-infection and prevalence of multidrug-resistant and extensively drug-resistant tuberculosis remain to be serious clinical problems. Development of new drugs is a potential solution to fight tuberculosis. In this decade, the development status of new antituberculous drugs has been greatly advanced by the leading role of international organizations such as the Global Alliance for Tuberculosis Drug Development, Stop Tuberculosis Partnership and Global Health Innovative Technology Fund. In this review, we introduce the development status of new drugs for tuberculosis, focusing on those derived from natural products.The Journal of Antibiotics advance online publication, 1 November 2017; doi:10.1038/ja.2017.126.

A nationwide survey of pediatric acquired demyelinating syndromes in Japan

OBJECTIVE

To investigate the clinical and epidemiologic features of pediatric acquired demyelinating syndromes (ADS) of the CNS in Japan.

METHODS

We conducted a nationwide survey and collected clinical data on children with ADS aged 15 years or younger, who visited hospitals between 2005 and 2007.

RESULTS

Among 977 hospitals enrolled, 723 (74.0%) responded to our inquiries and reported a total of 439 patients as follows: 244 with acute disseminated encephalomyelitis (ADEM), 117 with multiple sclerosis (MS), 14 with neuromyelitis optica (NMO), and 64 with other ADS. We collected and analyzed detailed data from 204 cases, including those with ADEM (66), MS (58), and NMO (10). We observed the following: (1) the estimated annual incidence rate of pediatric ADEM in Japan was 0.40 per 100,000 children (95% confidence interval [CI], 0.34-0.46), with the lowest prevalence in the north; (2) the estimated prevalence rate of MS was 0.69 per 100,000 children (95% CI, 0.58-0.80), with the lowest prevalence in the south; (3) NMO in Japan was rare, with an estimated prevalence of 0.06 per 100,000 children (95% CI, 0.04-0.08); and (4) the sex ratio and mean age at onset varied by ADS type, and (5) male/female ratios correlated with ages at onset in each ADS group.

CONCLUSIONS

Our results clarify the characteristic clinical features of pediatric ADS in the Japanese population.

Assembling of the Mycobacterium tuberculosis Cell Wall Core

The unique cell wall of mycobacteria is essential to their viability and the target of many clinically used anti-tuberculosis drugs and inhibitors under development. Despite intensive efforts to identify the ligase(s) responsible for the covalent attachment of the two major heteropolysaccharides of the mycobacterial cell wall, arabinogalactan (AG) and peptidoglycan (PG), the enzyme or enzymes responsible have remained elusive. We here report on the identification of the two enzymes of Mycobacterium tuberculosis, CpsA1 (Rv3267) and CpsA2 (Rv3484), responsible for this function. CpsA1 and CpsA2 belong to the widespread LytR-Cps2A-Psr (LCP) family of enzymes that has been shown to catalyze a variety of glycopolymer transfer reactions in Gram-positive bacteria, including the attachment of wall teichoic acids to PG. Although individual cpsA1 and cpsA2 knock-outs of M. tuberculosis were readily obtained, the combined inactivation of both genes appears to be lethal. In the closely related microorganism Corynebacterium glutamicum, the ortholog of cpsA1 is the only gene involved in this function, and its conditional knockdown leads to dramatic changes in the cell wall composition and morphology of the bacteria due to extensive shedding of cell wall material in the culture medium as a result of defective attachment of AG to PG. This work marks an important step in our understanding of the biogenesis of the unique cell envelope of mycobacteria and opens new opportunities for drug development.

Inhibition of the first step in synthesis of the mycobacterial cell wall core, catalyzed by the GlcNAc-1-phosphate transferase WecA, by the novel caprazamycin derivative CPZEN-45

Because tuberculosis is one of the most prevalent and serious infections, countermeasures against it are urgently required. We isolated the antitubercular agents caprazamycins from the culture of an actinomycete strain and created CPZEN-45 as the most promising derivative of the caprazamycins. Herein, we describe the mode of action of CPZEN-45 first against Bacillus subtilis. Unlike the caprazamycins, CPZEN-45 strongly inhibited incorporation of radiolabeled glycerol into growing cultures and showed antibacterial activity against caprazamycin-resistant strains, including a strain overexpressing translocase-I (MraY, involved in the biosynthesis of peptidoglycan), the target of the caprazamycins. By contrast, CPZEN-45 was not effective against a strain overexpressing undecaprenyl-phosphate-GlcNAc-1-phosphate transferase (TagO, involved in the biosynthesis of teichoic acid), and a mutation was found in the tagO gene of the spontaneous CPZEN-45-resistant strain. This suggested that the primary target of CPZEN-45 in B. subtilis is TagO, which is a different target from that of the parent caprazamycins. This suggestion was confirmed by evaluation of the activities of these enzymes. Finally, we showed that CPZEN-45 was effective against WecA (Rv1302, also called Rfe) of Mycobacterium tuberculosis, the ortholog of TagO and involved in the biosynthesis of the mycolylarabinogalactan of the cell wall of M. tuberculosis. The outlook for WecA as a promising target for the development of antituberculous drugs as a countermeasure of drug resistant tuberculosis is discussed.

Amycolamicin: a novel broad-spectrum antibiotic inhibiting bacterial topoisomerase

The abuse of antibacterial drugs imposes a selection pressure on bacteria that has driven the evolution of multidrug resistance in many pathogens. Our efforts to discover novel classes of antibiotics to combat these pathogens resulted in the discovery of amycolamicin (AMM). The absolute structure of AMM was determined by NMR spectroscopy, X-ray analysis, chemical degradation, and modification of its functional groups. AMM consists of trans-decalin, tetramic acid, two unusual sugars (amycolose and amykitanose), and dichloropyrrole carboxylic acid. The pyranose ring named as amykitanose undergoes anomerization in methanol. AMM is a potent and broad-spectrum antibiotic against Gram-positive pathogenic bacteria by inhibiting DNA gyrase and bacterial topoisomerase IV. The target of AMM has been proved to be the DNA gyrase B subunit and its binding mode to DNA gyrase is different from those of novobiocin and coumermycin, the known DNA gyrase inhibitors.

Brn-3b inhibits generation of amacrine cells by binding to and negatively regulating DLX1/2 in developing retina

During retinogenesis, the basic helix-loop-helix proneural gene math5 (atoh7) initiates the generation of the first-born neurons, retinal ganglion cells (RGCs), by activating a network of RGC transcription factors, including Brn-3b (POU4F2). Herein, we show that the expression of DLX1 and DLX2 is significantly down-regulated in math5-null retina but is markedly increased in Brn-3b-null retina. Interestingly, Brn-3b interacts with DLX1 through its homeodomain, and this interaction represses DLX1 activity. Retrovirus-mediated mis-expression of DLX1 or DLX2 dramatically increases the number of amacrine/bipolar cells and concurrently reduces rod photoreceptors. Conversely, combined ectopic expression of Brn-3b with DLX1 or DLX2 promotes the production of RGCs and inhibits amacrine cell differentiation. Thus, DLX1/2 play an essential role in cell fate selection between amacrine and RGCs. Brn-3b suppresses the role of DLX1/2 through physical interaction and biases the competent precursors toward RGC fates.

Abnormal fast activity before the onset of West syndrome

In our sequential EEG study performed on 68 infants with various pre- and perinatal brain insults, we found peculiar abnormal fast activity (AFAs) in 12 patients. 9 of the 12 patients with AFAs later developed West syndrome (WS) compared with only 3 of the 56 patients without AFAs (p<0.001, χ(2) test). We analyzed these AFAs using EEG topography, and compared them with ictal fast activity (IFA) corresponding to tonic spasms observed later in the same patients after they had developed WS. We also investigated the clinical and EEG features in these patients. AFAs were first observed commonly at 4-5 months of CA, before the onset of WS. AFA topographic maps revealed posterior predominance in 11 of the 12 patients; IFA maps also showed posterior predominance but were more widely distributed. We propose that, though AFAs and IFAs are different, they share certain aspects of their pathophysiology, and that the maturational process of the occipital cortex plays an important role in the shared aspects. Since AFAs are observed before the onset of WS, they can be considered a sign that WS is imminent.

Effects of intermittent Pringle's manoeuvre on cirrhotic compared with normal liver

BACKGROUND

Although patients with liver cirrhosis are supposed to tolerate ischaemia-reperfusion poorly, the exact impact of intermittent inflow clamping during hepatic resection of cirrhotic compared with normal liver remains unclear.

METHODS

Intermittent Pringle's manoeuvre was applied during minor hepatectomy in 172 patients with a normal liver, 59 with chronic hepatitis and 97 with liver cirrhosis. To assess hepatic injury, delta (D)-aspartate aminotransferase (AST) and D-alanine aminotransferase (ALT) (maximum level minus preoperative level) were calculated. To evaluate postoperative liver function, postoperative levels of total bilirubin, albumin and cholinesterase (ChE), and prothrombin time were measured.

RESULTS

Significant correlations between D-AST or D-ALT and clamping time were found in each group. The regression coefficients of the regression lines for D-AST and D-ALT in patients with normal liver were significantly higher than those in patients with cirrhotic liver. Irrespective of whether clamping time was 45 min or less, or at least 60 min, D-AST and D-ALT were significantly lower in patients with cirrhosis than in those with a normal liver. Parameters of hepatic functional reserve, such as total bilirubin, prothrombin time, albumin and ChE, were impaired significantly after surgery in patients with a cirrhotic liver.

CONCLUSION

Patients with liver cirrhosis had a smaller increase in aminotransferase levels following portal triad clamping than those with a normal liver. However, hepatic functional reserve in those with a cirrhotic liver seemed to be affected more after intermittent inflow occlusion.

Effects of intermittent Pringle's manoeuvre on cirrhotic compared with normal liver

BACKGROUND

Although patients with liver cirrhosis are supposed to tolerate ischaemia-reperfusion poorly, the exact impact of intermittent inflow clamping during hepatic resection of cirrhotic compared with normal liver remains unclear.

METHODS

Intermittent Pringle's manoeuvre was applied during minor hepatectomy in 172 patients with a normal liver, 59 with chronic hepatitis and 97 with liver cirrhosis. To assess hepatic injury, delta (D)-aspartate aminotransferase (AST) and D-alanine aminotransferase (ALT) (maximum level minus preoperative level) were calculated. To evaluate postoperative liver function, postoperative levels of total bilirubin, albumin and cholinesterase (ChE), and prothrombin time were measured.

RESULTS

Significant correlations between D-AST or D-ALT and clamping time were found in each group. The regression coefficients of the regression lines for D-AST and D-ALT in patients with normal liver were significantly higher than those in patients with cirrhotic liver. Irrespective of whether clamping time was 45 min or less, or at least 60 min, D-AST and D-ALT were significantly lower in patients with cirrhosis than in those with a normal liver. Parameters of hepatic functional reserve, such as total bilirubin, prothrombin time, albumin and ChE, were impaired significantly after surgery in patients with a cirrhotic liver.

CONCLUSION

Patients with liver cirrhosis had a smaller increase in aminotransferase levels following portal triad clamping than those with a normal liver. However, hepatic functional reserve in those with a cirrhotic liver seemed to be affected more after intermittent inflow occlusion.

[Metastatic lung cancer origin from osteosarcoma of mandible invading tracheal lumen]

A 52-year-old woman underwent the surgical treatment for osteosarcoma of the left mandible in 2003 and was followed up afterward. She suffered from dry cough and bloody sputum, and was admitted to our hospital in April 2007. Computed tomography (CT) revealed several nodules in bilateral lung, and bronchofiberscopy showed the endobronchial tumor obstructing in the right main bronchus. The metastatic tumor progressed in the right main bronchus from the right S6 lung segment. The tumor rapidly progressed in the right bronchus in comparison with the CT findings in about 2 weeks, and the possibility of the tracheal obstruction was considered. She underwent the right middle and lower lobectomy, and the endobronchial tumor was pulled through the right main bronchus. The postoperative course was uneventful, the patient was discharged on 14th postoperative day, and the chemotherapy using cisplatin (CDDP) and adriamycin (ADR) is on-going.

[Thymic carcinoma involving aortic arch; report of a case]

Adenocarcinoma of the thymus is a very rare malignant tumor. The standard treatment for advanced thymic carcinoma has not yet been established, and the prognosis is poor. We report a case of thymic carcinoma that involving the aortic arch and the innominate vein. A 78-year-old woman was admitted to our hospital complaining of hoarseness in April 2007. The computed tomography (CT) scan showed an anterior mediastinal tumor contiguous to the aortic arch and the innominate vein with swelling lymphnodes. Microspcopic examinations of specimens obtained by CT-guided needle biopsy revealed poorly differenciated adenocarcinoma. The carcinoembryonic antigen (CEA) level of serum elevated at 54.9 ng/ml. Thymic carcinoma was diagnosed. The chemoradiotherapy [concurrent, carboplatin (CBDCA) + paclitaxel(TXL)-->vinorelbine (NVB), 60 Gy] was performed, but the effect of the therapy was limited. The resection of the tumor with a part of aortic arch and other peripheral tissues was performed in Augast 2007. The postoperative course was uneventful and the CEA level of serum lowered to the normal. She was discharged 30 days after surgery.

[Right lung cancer with right aortic arch]

An abnormal shadow was detected on chest X-ray mass screening in an asymptomatic 63-year-old man. The further examinations revealed the shadow to be primary lung cancer (Rt. S6. adenocarcinoma, cT2N0M0, c-stage IB) with right aortic arch. We used 3 dimentional-computed tomography (3D-CT) to assess an anatomical feature of vessels in detail. The right lower lobectomy and the dissection of medi astinal lymph nodes was performed. We confirmed no abnormal anatomy of pulmonary artery and vein at surgery, and it was possible to perform right lower lobectomy with the common procedure. Since lymph node was found by intraopetrative pathological examination, since no metastasis from interlobar to subcarinal lymph node was found, we did not perform dissection of upper mediastinal dissection, which was equivalent to ND2a lymph nodes dissection of the left lung cancer in General Rule for Clinical and Pathological Record of Lung Cancer. The patient with right aortic arch is known to have variant anatomy of other intrathoracic vessels occasionally. 3D-CT was quite useful in assessing anatomical feature, and enabled us to perform safe operation.

Impact of a left-lobe graft without modulation of portal flow in adult-to-adult living donor liver transplantation

In adult-to-adult living donor liver transplantation (LDLT), left-lobe grafts can sometimes be small-for-size. Although attempts have been made to prevent graft overperfusion through modulation of portal inflow, the optimal portal venous circulation for a liver graft is still unclear. Hepatic hemodynamics were analyzed with reference to graft function and outcome in 19 consecutive adult-to-adult LDLTs using left-lobe grafts without modulation of graft portal inflow. Overall mean graft volume (GV) was 398 g, which was equivalent to 37.8% of the recipient standard liver volume (SV). The GV/SV ratio was less than 40% in 13 of the 19 recipients. Overall mean recipient portal vein flow (PVF) was much higher than the left PVF in the donors. The mean portal contribution to the graft was markedly increased to 89%. Average daily volume of ascites revealed a significant correlation with portal vein pressure, and not with PVF. When PVP exceeds 25 mmHg after transplantation, modulation of portal inflow might be required in order to improve the early postoperative outcome. Although the study population was small and contained several patients suffering from tumors or metabolic disease, all 19 patients made good progress and the 1-year graft and patient survival rate were 100%. A GV/SV ratio of less than 40% or PVF of more than 260 mL/min/100 g graft weight does not contraindicate transplantation, nor is it necessarily associated with a poor outcome. Left-lobe graft LDLT is still an important treatment option for adult patients.

Conversion of elective laparoscopic to open cholecystectomy between 1993 and 2004

BACKGROUND

Laparoscopic cholecystectomy (LC) is the standard treatment for symptomatic gallbladder disease. The identification of factors that reliably predict the likely need to convert LC to an open procedure would provide short-term benefits in terms of patient education and postoperative expectations.

METHODS

Between 1993 and 2004, 1179 elective LCs were attempted from a total of 1339 elective cholecystectomies. The change in conversion rate between 1993-1999 and 2000-2004 was analysed. Factors predictive of higher risk for conversion were also identified.

RESULTS

Eighty-nine LCs (7.5 per cent) required conversion. Gallbladder wall thickness and a history of common bile duct (CBD) stones, treated by preoperative endoscopic sphincterotomy, were predictors of conversion. The proportion of patients who underwent LC was the same in 1993-1999 (87.5 per cent) and 2000-2004 (88.8 per cent), but the conversion rate increased significantly from 5.3 to 10.6 per cent in these two time intervals. In addition, the proportion of patients with a history of CBD stones rose significantly, from 6.4 per cent in 1993-1999 to 11.0 per cent in 2000-2004.

CONCLUSION

The conversion rate increased over the 12-year interval of the study. A history of preoperative endoscopic sphincterotomy and a thickened gallbladder wall contributed to the likelihood of conversion.

Laparoscopy-assisted right hepatic lobectomy using a wall-lifting procedure

This article describes a new technique for performing a laparoscopy-assisted right hepatic lobectomy using a hanger wall-lifting procedure. The patient is placed in the left semi-lateral position. A cholecystectomy and hemi-hepatic vascular inflow control are then performed through a midline incision, through which the resected liver can be removed. Next, the right lower chest and right upper abdominal wall are lifted by two wires vertical to the abdominal wall. Two ports, a 5-mm port in right lateral abdomen for forceps and a 12-mm port just right of the umbilicus for the laparoscope, are inserted. The obtained view of the operative field in the right upper abdominal cavity is thus excellent. The laparoscopy-assisted mobilization of the right hepatic lobe is done with the assistance of a hand inserted through the midline incision, including a dissection of the hepato-renal ligament, the right triangular ligament, and the right coronary ligament. A parenchymal dissection is then performed using the Cavitron Ultrasonic Surgical Aspirator (CUSA) and the resected specimen is passed through the midline incision without any morcellation of the liver. This procedure can minimize the length of the wound, while avoiding the lethal complications associated with pneumoperitoneum.

Clinical significance of immunohistochemically detectable lymph node metastasis in adenocarcinoma of the ampulla of Vater

BACKGROUND

The aim of this study was to assess the impact of immunohistochemically identified lymph node metastasis on survival in patients with carcinoma of the ampulla of Vater.

METHODS

Three hundred and twenty-six regional lymph nodes dissected from pancreatoduodenectomy specimens from 25 patients with ampulla of Vater carcinoma were immunostained with anticytokeratin antibody (CAM 5.2). The clinicopathological significance of immunohistochemically detectable lymph node metastasis was evaluated and compared with that of other potential prognostic factors.

RESULTS

The frequency of lymph node involvement in relation to the total number of dissected lymph nodes increased from 5.5 per cent (18 of 326) using haematoxylin and eosin staining to 9.5 per cent (31 of 326) using cytokeratin immunostaining (P < 0.001). Lymph node involvement was revealed by haematoxylin and eosin staining in eight of 25 patients and by cytokeratin immunostaining in 11 of 25 patients (P = 0.006). Absence of immunohistochemically detectable lymph node metastasis was identified as an independent predictor of improved postoperative survival.

CONCLUSION

Immunostaining of dissected lymph nodes adds additional information to data obtained by conventional haematoxylin and eosin staining when determining the prognosis of patients with carcinoma of the ampulla of Vater.

Change in broth culture is associated with significant suppression of Escherichia coli death under high magnetic field

When Escherichia coli B was cultivated under an inhomogeneous magnetic field of 5.2-6.1 T, a significant 100,000-fold suppression of cell death was observed [Bioelectrochemistry 53 (2001) 149]. The limited magnetic field exposure for 12 h after logarithmic growth phase was sufficient to observe similar suppressive effects on cell death [Bioelectrochemistry 54 (2001) 101]. These results suggest some possible changes in either the medium or the cells during the magnetic field exposure. When the cell-free filtrate of the broth cultured under the magnetic field for 10 h and the cells of E. coli cultivated under the geomagnetic field for 30 h were mixed, and the mixture was subsequently cultivated under the geomagnetic field, the number of cells observed in the filtrate exposed to the high magnetic field was 20,000 times higher than that in the filtrate exposed to the geomagnetic field. When the cells cultivated under the magnetic field for 10 h and the cell-free filtrate of the broth culture exposed to the geomagnetic field were mixed, only a 50-fold difference in the number of cell between under the magnetic field and under the geomagnetic field was observed. This suggests that the filtrate of the broth culture exposed to the magnetic field is primarily responsible for the cell death suppression. It was also revealed that the small difference in pH of the filtrates of the broth culture between under the magnetic field and under the geomagnetic field was critical for the cell death suppression.

Twelve hours exposure to inhomogeneous high magnetic field after logarithmic growth phase is sufficient for drastic suppression of Escherichia coli death

When Escherichia coli B was aerobically grown at 43 degrees C in a medium whose concentration was one-fourth that of the Luria-Bertani (LB) medium supplemented with 1.5 g/l of glutamic acid, drastic cell death was observed after the end of the logarithmic growth phase. However, when the same experiment was conducted under inhomogeneous 5.2-6.1 T magnetic field, cell death was extremely suppressed and the ratio of viable cell number under high magnetic field to that under geomagnetic field reached as much as 100,000. When the magnetic field exposure was restricted to 12 h after the logarithmic growth phase, a similar high degree of suppressive effect on the death was observed. The findings that the amount of sigma S protein encoded by the rpoS gene under the high magnetic field was larger than that under the geomagnetic field, and that the magnetic field effect disappeared when the rpoS gene-deficient strain was cultivated under the high magnetic field, suggest the interaction of magnetic field with a stationary phase specific gene.

Cromolyn sodium suppresses eosinophilic inflammation in patients with aspirin-intolerant asthma

BACKGROUND

Although administration of cromolyn sodium is one of the most useful drugs for the treatment of aspirin-intolerant asthma (AIA), both its pharmacologic mechanism of action and association with the pathogenesis remain obscure.

OBJECTIVE

This study was designed to investigate the protective effect of cromolyn sodium on airway responsiveness to the sulpyrine provocation test, and to examine whether its activity is associated with a reduction in eosinophilic inflammation.

METHODS

Patients were randomly assigned to receive cromolyn sodium (20 mg/2 mL, or 1 ampoule; Fujisawa, Osaka, Japan) or matching placebo (2 mL of saline) four times daily for 1 week. We evaluated the effects of pretreatment with cromolyn sodium on bronchoconstriction precipitated by inhalation of sulpyrine in 16 adult patients with mild or moderate AIA; those who were in stable clinical condition were allocated to this study. A double-blind, randomized, crossover design was used. Blood and sputum samples were taken in the morning on the sulpyrine provocation testing day. Eosinophil counting and measurement of eosinophilic cationic protein (ECP) were performed.

RESULTS

Inhaled cromolyn sodium protect against aspirin-induced attacks of asthma through mechanisms not related to the bronchodilator property, but related to the improvement of the bronchial hypersensitivity, almost completely in all patients (P < 0.001). After 1 week's treatment with cromolyn sodium, patients' symptoms, blood and sputum eosinophils counts, and sputum ECP levels were significantly decreased compared with both placebo and baseline.

CONCLUSIONS

Cromolyn sodium has a bronchial anti-inflammatory effect associated with decreased eosinophilic infiltration. This is the first report that cromolyn sodium reduces blood and sputum eosinophils counts and sputum ECP levels in AIA.

Drastic high magnetic field effect on suppression of Escherichia coli death

When Escherichia coli B was aerobically grown in a medium containing one-fourth the concentration of the LB medium supplemented with glutamic acid at 43 degrees C under an inhomogeneous 5.2-6.1 T magnetic field, the number of cells in the stationary phase under the high magnetic field was 100,000 times higher than that under a geomagnetic field. The finding that the amount of sigma S factor encoded by the rpoS gene under the high magnetic field was larger than that under the control geomagnetic field indicated that the activity of the rpoS gene was affected by the high magnetic field.

[Effectiveness of high-dose, intermittent 5'-DFUR therapy for advanced gastric cancer]

We report a case of advanced gastric cancer with multiple liver metastases and peritoneal dissemination. The patient was effectively treated with high-dose 5'-DFUR. A 52-year-old patient with advanced gastric cancer and multiple liver metastases, who showed a high serum level of CEA and CA19-9 underwent simple D1 gastrectomy. Thereafter, he received per os 1,200 mg/day of 5'-DFUR intermittently (5 days a week) and TAI every four months postoperatively. The serum levels of both CEA and CA19-9 fell dramatically to within the normal range and were maintained thereafter until the present. The size and number of the liver metastases dramatically decreased, judging from CT and angiography findings.

Normotonic cell shrinkage because of disordered volume regulation is an early prerequisite to apoptosis

A major hallmark of apoptosis is normotonic shrinkage of cells. Here, we studied the relation between apoptotic cell shrinkage and apoptotic cell death. Induction of the apoptotic volume decrease (AVD) under normotonic conditions was found to be coupled to facilitation of the regulatory volume decrease (RVD), which is known to be attained by parallel operation of Cl(-) and K(+) channels, under hypotonic conditions. Both the AVD induction and the RVD facilitation were found to precede cytochrome c release, caspase-3 activation, DNA laddering, and ultrastructural alterations in three cell types after apoptotic insults with two distinct apoptosis inducers. Also, the AVD was not prevented by a broad-spectrum caspase inhibitor. When the AVD induction and the RVD facilitation were prevented by blocking volume-regulatory Cl(-) or K(+) channels, these cells did not show succeeding apoptotic biochemical and morphological events and were rescued from death. Thus, it is concluded that the AVD, which is caused by disordered cell volume regulation, is an early prerequisite to apoptotic events leading to cell death.

A role for p27/Kip1 in the control of cerebellar granule cell precursor proliferation

During development, control of proliferation of neuronal precursor cells plays a crucial role in determining the number of neurons. Proliferation is driven by mitogens, but how it is terminated remains a mystery. In this study, we examined the role of cyclin-dependent kinase inhibitors in the control of proliferation of cerebellar granule cell precursors (GCPs). Among the inhibitors we examined, only p27/Kip1 (p27) was expressed at significant levels in cells of the granule cell lineage in the developing and adult cerebellum. In developing cerebella, p27 was expressed in the external germinal layer (the deeper regions), the molecular layer, and the granule layer. In adult cerebella, p27 was expressed in the cells of the granule layer. We isolated and purified GCPs from cerebella of developing mice and examined their bromodeoxyuridine (BrdU) uptake and p27 expression at various times. We found that there was an inverse correlation between BrdU uptake and p27 expression. Even in the presence of saturating amounts of Sonic hedgehog, a potent mitogen, the cells eventually stopped dividing and differentiated, expressing p27 strongly. We also examined mice in which one or both copies of the p27 gene have been inactivated by targeted gene disruption and found that their cerebella were larger than those of wild-type mice. In cell cultures, GCPs prepared from p27-deficient mice showed enhanced proliferation compared with GCPs from wild-type mice. Taken together, these results suggest that there is an intracellular mechanism that stops GCP division and causes GCPs to differentiate and that p27 is part of this mechanism.

Effect of pranlukast on bronchial inflammation in patients with asthma

BACKGROUND

Pranlukast (8-[p-(4-phenylbutyloxy) benzol] amino-2-[tetrazol-5-yl]-4-oxo-4H-1-benzopyran hemihydrate), a selective cysteinyl leukotriene receptor antagonist, has been reported to exhibit not only antileukotrine activity but also pharmacological activity including antieosinophilic effects.

OBJECTIVE

This study was designed to investigate whether the antiasthmatic activity of pranlukast is associated with a reduction in eosinophilic inflammation.

METHODS

A double-blind, randomized, crossover design was used. Subjects received 225 mg of pranlukast or placebo orally twice daily for 4 weeks and then, after a washout period of at least 4 weeks, crossed over to receive the alternative treatment. We assessed the effects of pretreatment with pranlukast on bronchoconstriction precipitated by inhalation of methacholine in 32 adult patients with mild or moderate bronchial asthma; those who were in stable clinical condition were allocated to this study. Blood and sputum samples were taken the morning of the methacholine provocation test. Eosinophil counts and measurement of eosinophilic cationic protein (ECP) were performed.

RESULTS

After the 4 weeks of treatment with pranlukast, patients' symptoms, blood eosinophils, serum ECP, sputum eosinophils, and sputum ECP were significantly decreased. Furthermore, values of PC20-methacholine significantly improved in the treatment with pranlukast.

CONCLUSION

Our results suggest that pranlukast has an anti-inflammatory effect on bronchial eosinophilic infiltration. This study raises further interesting therapeutic possibilities and argues for further trials of new approaches to the treatment of bronchial asthma.

Evaluation of psychological effects due to bed rest

The psychological condition of astronauts is an important factor for ensuring mission success in limited space. Head-down tilting bed rest is a well-accepted method by which to simulate an acute stage of human adaptation to the weightless state in space flight. In our previous studies, the enhancement of depressive and neurotic levels occurred during a 20-day horizontal bed rest. In this study, we attempted to examine the depressive and neurotic levels, the mood status, and behavioral tendency of the subjects and to analyze the changes of 24-hour urinary excretion of 17-hydroxycorticosteroid-glucronides (17-OHCS) for an indicator of changes in the endocrine system due to physical and psychological stress during a 20-day 6-degrees head-down tilting bed rest (BR).

Immobilization on the day 14th does not disrupts the basic diurnal rhythm of bone resorption

Weight bearing and physical activity are important mechanical stimuli to bone growth and metabolism, and microgravity, such a space flight and/or bed rest, induces bone resorption and bone loss. An increased excretion of urinary Ca, an increased bone resorption and a decreased bone mineral density (BMD) have been observed in bed rest experiment of healthy subjects. Bone resorption markers show the specific circadian rhythms in human. Cross-linked carboxyl-terminal telopeptide of type I collagen (ICTP) and the urinary excretion of deoxypyridinoline (Dpy) are the highest in the early morning and the lowest late at night. Bed rest immobilization might influence these rhythms, due to no mechanical loading with loss of daily life activity. Bone resorption markers in healthy subjects had been compared between before and during bed rest to determine disruption of diurnal rhythms of bone resorption.

Clarithromycin suppresses bronchial hyperresponsiveness associated with eosinophilic inflammation in patients with asthma

BACKGROUND

Although long-term administration of 14-membered macrolide antibiotics is a therapeutic alternative in asthma, both its pharmacologic mechanism of action and association with the pathogenesis of asthma remain obscure.

OBJECTIVE

This study investigated the suppressive effect of clarithromycin on airway responsiveness to methacholine provocation testing and examined whether chrarithromycin's antiasthmatic activity is associated with a reduction in eosinophilic inflammation.

METHODS

For 8 weeks, patients received 200 mg of clarithromycin or identical-appearing placebo twice daily. We assessed the effects of treatment with clarithromycin on bronchoconstriction precipitated by inhalation of methacholine in 17 adults with mild or moderate bronchial asthma who were in stable clinical condition. A double-blind, randomized, crossover design was used. Eosinophil counts and eosinophilic cationic protein (ECP) levels were determined in blood and sputum samples obtained on the morning of the methacholine provocation testing day.

RESULTS

After 8 weeks of treatment with clarithromycin, patients' symptoms, blood and sputum eosinophils counts and sputum ECP levels were significantly decreased compared with both placebo and baseline. Furthermore, values of PC20 methacholine improved in all patients after clarithromycin treatment.

CONCLUSIONS

Clarithromycin has a bronchial anti-inflammatory effect associated with decreased eosinophilic infiltration. This study suggests interesting therapeutic possibilities for bronchial asthma that warrant further trials.

Efficacy of leukotriene receptor antagonist in bronchial hyperresponsiveness and hypersensitivity to analgesic in aspirin-intolerant asthma

BACKGROUND

Albeit its exact pathogenesis is still ambiguous; aspirin-intolerant asthma is one of several types of asthma for which antileukotriene therapy is useful, because it is widely accepted that bronchial over-production of leukotrienes may be involved in its pathogenesis. Pranlukast (8-[p-(4-phenylbutyloxy) benzol] amino-2-(tetrazol-5-yl)-4-oxo-4H-1-benzopyran hemihydrate), a selective cysteinyl leukotriene receptor antagonist, is now widely used in the treatment of asthma.

OBJECTIVE

This study was designed to investigate the protective effect of pranlukast on airway sensitivity to sulpyrine provocation testing, bronchial responsiveness to methacholine provocation testing, and to investigate whether this protective activity is associated with a reduction in aspirin-induced excretion of urinary LTE4 (uLTE4), a marker of the cysteinyl leukotriene (LT) overproduction that participates in the pathogenesis of aspirin-induced asthma.

METHODS

We assessed the effects of pretreatment with pranlukast on bronchoconstriction precipitated by inhalation of methacholine and sulpyrine in 16 adult patients with mild or moderate aspirin-intolerant asthma; those who were in stable clinical condition and were hypersensitive to sulpyrine provocation testing were allocated to this study. A double-blind, randomized, crossover design was used. uLTE4 was measured using combined reverse-phase high-performance liquid chromatography (rp-HPLC)/enzyme immunoassay.

RESULTS

Pranlukast protected against analgesic-induced bronchoconstriction through mechanisms that were not related to the bronchodilator property, but were related to the improvement both of bronchial hyperresponsiveness and hypersensitivity to analgesic (P < 0.005 and P < 0.0001). Pranlukast showed little effect on excretion of uLTE4.

CONCLUSION

These results support the hypothesis that cysteinyl leukotriene is one of the most important components in the pathogenesis of aspirin-intolerant asthma. Pranlukast improves not only hypersensitivity to analgesic, but also bronchial hyperresponsiveness in aspirin-intolerant asthma. It is also possible that pranlukast has another anti-asthmatic effect besides that of a leukotriene receptor antagonist.

Possible involvement of a chloride-bicarbonate exchanger in apoptosis of endothelial cells and cardiomyocytes

We examined the role of ion movement in staurosporine-induced apoptosis of vascular endothelial cells. Cultured vascular endothelial cells from bovine carotid arteries were used. Apoptosis was determined by propidium iodide assay. Treatment of the endothelial cells with staurosporine (10 nmol/l-1 micromol/l) for 6 h induced nuclear fragmentation in a dose-dependent manner. Staurosporine (1 micromol/l) elicited apoptosis in 70.5+/-1.5% of cells. Concomitant treatment of endothelial cells with 1 mmol/l of 4, 4-diisothiocyanatostilbene-2,2-disulfonic acid (DIDS), a chloride-bicarbonate exchange blocker, completely inhibited staurosporine-induced apoptosis. Other ion transporter inhibitors such as dimethyl amiloride and anthracene-9 carboxylic acid were less effective inhibitors of staurosporine-induced apoptosis of endothelial cells. DIDS prevented staurosporine-induced apoptosis of endothelial cells as well as cardiomyocytes. Next, we determined whether chloride ions or bicarbonate are involved in apoptosis. Incubation with a chloride ion removal buffer did not inhibit staurosporine-induced apoptosis of endothelial cells. However, endothelial cell apoptosis was completely suppressed by an inhibitor of caspase, benzyloxycarbonyl-Asp-CH(2)-O(C)O-dichlorobenzene (zD-dcb, 50 micromol/l). Staurosporine (1 micromol/l) increased the intracellular pH of endothelial cells, and DIDS (1 mmol/l), but not a caspase inhibitor, inhibited this increase in pH caused by staurosporine. Our findings suggest that endothelial cell apoptosis induced by staurosporine may be associated with the Cl(-)and bicarbonate (HCO-3) ions. Thus, Cl(-)efflux from cells or HCO-3 influx to cells (which increases pH) may play an important role in signal transduction leading events such as activation of caspase in staurosporine-induced apoptosis.

Amalgam allergy associated with exacerbation of aspirin-intolerant asthma

BACKGROUND

Aspirin-intolerant asthma can be induced not only by acidic analgesics (including acetylsalicylic acid), which effectively inhibit cyclo-oxygenase, but also by cross-reactivity with paraben, and other chemical additives.

OBJECTIVE

We examined whether amalgam allergy is involved in the pathogenesis of a aspirin-intolerant asthma.

METHODS

We present the first case of aspirin-intolerant asthma that improved after the removal of dental amalgam. In addition, we performed both the methacholine provocation testing and sulpyrine provocation testing before and after the removal of dental amalgam.

RESULTS

In addition, the methacholine concentration causing a 20% fall in FEV1 in provocation tests rose significantly, though hypersensitivity to analgesics evaluated with sulpyrine provocation testing did not decrease. These results suggest that amalgam sensitization is involved in bronchial hyperresponsiveness in aspirin-intolerant asthma.

CONCLUSION

Sensitivity to amalgam may cause exacerbation of aspirin-intolerant asthma in some patients. To the best of our knowledge, this is the first case report of amalgam allergy associated with aspirin-intolerant asthma.

Evaluation of local excision for sessile-type lower rectal tumors

BACKGROUND/AIMS

A study was undertaken to evaluate the surgical morbidity and risk of recurrence in patients undergoing local excision for rectal carcinoma.

METHODOLOGY

Twenty patients with well or moderately differentiated lesions less than 6 cm in diameter, which were difficult to remove endoscopically but had no clinically involved regional nodes, were eligible for local excision.

RESULTS

The transanal approach was simple and had few complications. After posterior parasacral excision, 3 patients developed rectocutaneous fistulas, and 1 of them died. None of the 12 patients with cancer extension limited to the lesser depth of the submucosa died of rectal cancer. Among 8 patients with cancer invasive into the greater depth of the submucosa or deeper, 5 underwent additional radical resection, and regional lymph node metastasis was revealed in 2.

CONCLUSIONS

Transanal excision is suitable for curative resection of lower rectal tumors when the cancer extends only to the lesser depth of the submucosa. The procedure should be defined as a total excisional biopsy until the results of histologic examination are obtained.

Clinical evaluation of 3D-CT cholangiography for preoperative examination in laparoscopic cholecystectomy

Three-dimensional-computed tomography (3D-CT) cholangiography is a 3D shaded surface display image of the biliary tract obtained by using helical CT after intravenous cholangiography or cholangiography per percutaneous transhepatic cholangio-drainage tube. We investigated whether 3D-CT cholangiography could provide a useful image, for preoperative examination in laparoscopic cholecystectomy. Sixty-five patients with biliary diseases were examined by 3D-CT cholangiography. Helical scanning was performed on a Proceed Accell (GE Medical Systems, Waukesha, WI, USA). Three-dimensional images were created using an independent workstation. A clear image of the common bile duct was obtained for all patients (100%) by 3D-CT cholangiography. The gallbladder was well visualized in 54 (93%) and the cystic duct was shown to be opacified in 55 (95%) of the 58 patients with a gallbladder. Thirty-one patients were diagnosed as having gallstones by 3D-CT cholangiography (sensitivity. 72.1%; specificity, 100%; accuracy, 79.3%), while 43 were diagnosed as having cholecystolithiasis by ultrasonography. The advantages of 3D-CT cholangiography were a low level of invasiveness, easily obtained images compared to those obtained with endoscopic retrograde cholangiography (ERC), good opacification, and provision of a three-dimensional understanding of the biliary system, especially of the cystic duct. When combined with ultrasonography and routine liver function tests, 3D-CT cholangiography was considered very useful for obtaining information before laparoscopic cholecystectomy. It allowed the omission of ERC in many patients who were considered to have no common bile duct stone, by employment of 3D-CT cholangiography.