Phospholipids from Bombycis corpus and their neurotrophic effects

Three phospholipids (4-6) and three aromatic amines (1-3) were obtained from the methanol extract of Bombycis corpus. Based on spectral data, their structures have been elucidated as nicotiamide (1), cytidine (2), adenine (3), 1-O-(9Z-octadecenoyl)-2-O-(8Z,11Z-octadecadienoyl) sn-glycero-3-phosphorylcholine (4), 1,2-di-O-hexadecanoyl-sn-glycero-3-phosphorylcholine (5) and 1,2-di-O-9Z-octadecenoyl-sn-glycero-3-phosphorylcholine (6). We examined the effects of compounds on synthesis of NGF in cultured astrocytes. By RT-PCR analysis, expresison of NGF mRNA in astrocytes cultured in serum-starvation increased after the addition of phospholipid (10 microM). The NGF content in the culture medium was significantly increased by compound 5, compared with the control value. These results suggest that three phospholipid compounds isolated from the methanol extract of Bombycis corpus may exert neurotrophic effects by stimulation of NGF synthesis in astrocytes.

Role of rho-kinase activity in angiotensin II-induced contraction of rabbit clitoral cavernosum smooth muscle

Isometric tension measurement using a selective Rho-kinase inhibitor (+)- (R)-trans4-(1-aminoethyl)-N-(4-pyridyl)cyclohexanecarboxamide (Y-27632) and a selective myosin light chain kinase (MLCK) inhibitor 1-(5-iodonaphthalene-1-sulfonyl)-1H-hexahydro-1,4-diazepine hydrochloride (ML7) were used in rabbit clitoral cavernosum smooth muscle (CSM). N(G)-nitro-L-arginine methyl ester (L-NAME) was used to evaluate the relationship between NO release and Rho-kinase. Y-27632 significantly attenuated contractions induced by ANG II, dose-dependently. However, ML7 did not affect the contractile response to ANG II except in the high concentrations of ML7. Y-27632 inhibited contraction with phenylephrine (PhE), but ML7 did not inhibit contraction with PhE. Nitric oxide synthase inhibitor (NAME) did not affect the Y-27632-induced relaxation in the pre-contracted strip with PhE. The present study demonstrates that G-protein-coupled increase in myofilament Ca(2+) sensitivity mediated through the RhoA/Rho-kinase signal pathway is involved in the control by ANG II of the clitoral CSM tone. RhoA/Rho-kinase pathway acts in the ANG II-induced contraction independently of the NO pathway.

Primary antiphospholipid syndrome presenting with abdominal angina and splenic infarction

The antiphospholipid syndrome is an autoimmune hypercoagulability syndrome in which a wide variety of thromboembolic diseases may occur. Gastrointestinal manifestations associated with vascular occlusion include Budd-Chiari syndrome, hepatic and splenic infarction, pancreatitis, omental and intestinal infarction, and esophageal variceal bleeding due to portal vein thrombosis, but chronic mesenteric ischemia associated with mesenteric arterial thrombosis is very rare in this syndrome. We experienced a female patient with primary antiphospholipid syndrome with abdominal angina and splenic infarction associated with celiac trunk and mesenteric arterial thromboses. This is the first report describing chronic mesenteric ischemia and splenic infarction in a patient with primary antiphospholipid syndrome.

Activation of caspase-8 during N-(4-hydroxyphenyl)retinamide-induced apoptosis in Fas-defective hepatoma cells

We observed that N-(4-hydroxyphenyl)retinamide (4HPR), a chemopreventive and chemotherapeutic agent, effectively induced apoptosis in hepatoma cells. Interestingly, Fas-negative (Hep 3B and PLC/PRF/5) hepatoma cells were shown to be more susceptible to apoptosis induced by 4HPR than were Fas-positive (Hep G2 and SK-HEP-1) hepatoma cells. Thus, we explored the mechanisms underlying 4HPR-induced apoptosis in Fas-defective hepatoma cells. Hep 3B cells stably expressing the dominant-negative Fas-associated death domain (dnFADD) showed no alteration in 4HPR drug susceptibility, but when stably expressing E1B19K, Crm A, or dominant-negative FLICE (dnFLICE), Hep 3B cells were resistant, suggesting that 4HPR-induced apoptosis was mediated by caspase-8 activation. Furthermore, apoptosis could be completely blocked by Z-VAD-FMK (a general caspase inhibitor) or by IETD-CHO (a caspase-8 inhibitor), but was only partially blocked by Ac-DEVD-CMK (a caspase-3 inhibitor), by N-acetyl-L-cysteine (NAC) (an antioxidant), by N-acetyl-leucyl-leucyl-norleucinal (ALLN) (a calpain inhibitor I), or by Z-LEHD-FMK (a caspase-9 inhibitor). Time-sequence analysis of the induction of apoptosis by 4HPR revealed that an initial caspase-8 activation was followed by late mitochondrial cytochrome c release and minor caspase-9 activation, which suggested that caspase-8 activation is the primary upstream regulatory point. Activation of Bid or induction of proapoptotic Bax was not observed during apoptosis. In contrast, Bcl-xL expression was decreased during 4HPR-induced apoptosis. Taken together, these results indicate that 4HPR may be a potential chemotherapeutic drug, which is able to induce apoptosis in Fas-defective hepatoma cells through caspase-8 activation.

Low-level resistance to glycopeptides amongst staphylococcus species: surveillance in a university hospital and evaluation of a vancomycin screening agar

The prevalence of low-level resistance to glycopeptides (teicoplanin MIC > or = 8 microg/mL and vancomycin MIC > or = 4 microg/mL) among staphylococci was investigated over a 15 month period. A total of 2,279 isolates (1,519 S. aureus, 760 coagulase-negative staphylococcus (CNS)) were screened using inoculum of 10(6) CFU/mL and Mueller-Hinton agars supplemented with 8 microg/mL of teicoplanin. Of these, 218 isolates (136 S. aureus and 82 CNS) grew on the screening agar. For these isolates, teicoplanin and vancomycin MICs were determined by agar dilution method and a vancomycin agar screening method was evaluated. The prevalence of low-level resistance to teicoplanin and vancomycin was 7.8% and 0.1% for S. aureus and 8.8% and 0.8% for CNS, respectively. The brain heart infusion agar containing 4 microg/mL of vancomycin failed to detect two out of eight staphylococcal isolates with vancomycin MICs of 4 microg/mL. Furthermore, the method appeared to lack reproducibility. Considering the increasing incidence of vancomycin treatment failure in staphylococcal infection, a more reliable screening method is required.

Absence of mutation in the region (nt. 710-1010) of pbp4 gene in clinical isolates of Staphylococcus aureus with low-level teicoplanin resistance

Resistance to teicoplanin in clinical isolates of Staphylococcus aureus has increased in frequency. Detection is difficult due to heterogeneous phenotypes of these strains. Two mutations in pbp4 have recently been identified in glycopeptide resistant laboratory strains. We investigated to determine if these mutations could be used to screen clinical isolates for teicoplanin resistance. Of 41 clinical isolates screened, none contained the mutations in pbp4 indicating these mutations cannot be used as a molecular diagnostic tool for glycopeptide resistance.

Palliation of postoperative gastrointestinal anastomotic malignant strictures with flexible covered metallic stents: preliminary results

PURPOSE

To evaluate the efficacy of the placement of covered metallic stents for palliation of gastrointestinal anastomotic strictures secondary to recurrent gastric cancer.

METHODS

Under fluoroscopic guidance, placement of one or two self-expandable covered metallic stents was attempted perorally in 11 patents (aged 48-76 years) with anastomotic stenoses due to recurrent gastric malignancies. The strictures involved both the afferent and efferent loops in three patients. All patients had poor peroral food intake with severe nausea and vomiting after ingestion. The technical and clinical success was evaluated.

RESULTS

Placement of the covered stent was technically successful in 13 of 15 (87%) attempts in ten patients. After the procedure, 9 of 11 (82%) patients overall were able to ingest at least a liquid diet and had markedly decreased incidence of vomiting. During the follow-up of 2-31 weeks (mean 8.5 weeks) there were no major complications.

CONCLUSION

These preliminary results suggest that flexible, covered stents may provide effective palliation of malignant anastomotic stricture secondary to recurrent gastric cancer.

Involvement of an extracellular protease in algicidal activity of the marine bacterium Pseudoalteromonas sp. strain A28

The marine bacterium Pseudoalteromonas sp. strain A28 was able to kill the diatom Skeletonema costatum strain NIES-324. The culture supernatant of strain A28 showed potent algicidal activity when it was applied to a paper disk placed on a lawn of S. costatum NIES-324. The condensed supernatant, which was prepared by subjecting the A28 culture supernatant to ultrafiltration with a 10,000-M(w)-cutoff membrane, showed algicidal activity, suggesting that strain A28 produced extracellular substances capable of killing S. costatum cells. The condensed supernatant was then found to have protease and DNase activities. Two Pseudoalteromonas mutants lacking algicidal activity, designated NH1 and NH2, were selected after N-methyl-N'-nitrosoguanidine mutagenesis. The culture supernatants of NH1 and NH2 showed less than 15% of the protease activity detected with the parental strain, A28. The protease was purified to homogeneity from A28 culture supernatants by using ion-exchange chromatography followed by preparative gel electrophoresis. Paper-disk assays revealed that the purified protease had potent algicidal activity. The purified protease had a molecular mass for 50 kDa, and the N-terminal amino acid sequence was determined to be Ala-Thr-Pro-Asn-Asp-Pro. The optimum pH and temperature of the protease were found to be 8.8 and 30 degrees C, respectively, by using succinyl-Ala-Ala-Pro-Phe-p-nitroanilide as a substrate. The protease activity was strongly inhibited by phenylmethylsulfonyl fluoride, diisopropyl fluorophosphate, antipain, chymostatin, and leupeptin. No significant inhibition was detected with EDTA, EGTA, phenanthroline or tetraethylenepentamine. These results suggest that Pseudoalteromonas sp. strain A28 produced an extracellular serine protease which was responsible for the algicidal activity of this marine bacterium.

Synthesis and antimicrobial activity of squalamine analogue

Synthesis and antimicrobial activity of squalamine analogue 2 are reported. The synthesis of 2 was accomplished from bisnoralcohol 3. The spermidine moiety was introduced via reductive amination of an appropriately functionalized 3beta-aminosterol with spermidinyl aldehyde 17 utilizing sodium triacetoxyborohydride as the reducing agent. Compound 2 shows weaker antimicrobial activity than squalamine.

Purification and characterization of biosurfactants from Nocardia sp. L-417

The Nocardia sp. L-417 strain grown with n-hexadecane as a carbon source produced two types of biosurfactant that have different characteristics. These biosurfactants were purified by procedures that included ammonium sulphate fractionation, chilled acetone and hexane treatments, silica-gel column chromatography and Sephadex LH-20 gel filtration. The purified biosurfactants were very stable over a broad range of pHs (2-12) and temperatures (100 degrees C, 3 h). The biosurfactant type I had strong properties as an emulsifying agent and as an emulsion-stabilizing agent, whereas type II had a strong ability to reduce surface tension.

Screening method for detecting staphylococci with reduced susceptibility to teicoplanin

The incidence of infections caused by staphylococci with decreased susceptibility to teicoplanin (MIC>/=8 microg/ml) is increasing, but the disk diffusion test has difficulty detecting this low level of resistance. In addition, detection is complicated because of the heterogeneous phenotypes for teicoplanin. In this study, we evaluated an agar screening method to detect staphylococci with decreased susceptibility to teicoplanin or heterogeneous resistance. First, to investigate the inoculum density and teicoplanin concentration of screening agar, we used 10(5) and 10(6) CFU/ml and Mueller-Hinton agars supplemented with 6 and 8 microg of teicoplanin/ml to test 39 genetically distinct staphylococcal strains (15 strains with teicoplanin MICs>/=8 microg/ml and 24 strains with teicoplanin MICs</=4 microg/ml). On the basis of the results obtained, a final inoculum of 10(6) CFU/spot and a teicoplanin concentration of 8 microg/ml were selected. By this screening method, all strains having teicoplanin MICs>/=8 microg/ml or showing heteroresistance could be detected. These findings indicate that the method can be used as a reliable screening method for detecting staphylococci with reduced susceptibility to teicoplanin.

Effect of nodularin on the expression of glutathione S-transferase placental form and proliferating cell nuclear antigen in N-nitrosodiethylamine initiated hepatocarcinogenesis in the male Fischer 344 rat

The tumor-promoting effect of nodularin during carcinogenesis was investigated. Male Fischer 344 rats were injected with nodularin for 10 weeks from week 3 after N-nitrosodiethylamine initiation without partial hepatectomy. Rats were further maintained for 10 weeks after the cessation of nodularin and were periodically killed. In contrast to the minimal foci in the DEN and nodularin alone groups, treatment with DEN and nodularin produced four kinds of nodules with eosinophilic, clear, mixed and basophilic cells. After the cessation of nodularin, the maximally increased number, but not the area, of glutathione S-transferase placental form-positive [GST-P(+)] nodules at week 12 decreased significantly and the appearance of two types of hyperplastic nodules was noted by GST-P immunostaining; homogeneously stained dense nodules (DN) and heterogeneously stained pale nodules (PN), which appeared only after the cessation of nodularin. DN were well circumscribed by enzyme-altered cells, as opposed to poorly in PN. Moreover, normal-appearing hepatocytes replaced the enzyme-altered cells in PN. In contrast to the higher PCNA index in GST-P(+) DN, the background level returned to that of the control at week 15. PCNA indices in DN were significantly higher than in PN, which were still higher than the control, indicating that nodularin affected the PCNA index differentially in the altered and unaltered hepatocytes. However, nodularin without DEN initiation significantly increased the PCNA index through initial cell death and subsequent hepatocyte proliferation. These results suggest that: (i) nodularin has a promoting effect by inducing hepatocyte proliferation in both enzyme-altered hyperplastic nodules and the surrounding parenchyma; (ii) proliferation is transient in background cells but not in enzyme-altered hepatocytes; (iii) GST-P(+) DN can be regarded as progressive and GST-P(+) PN as regressive, revealed by both immunohistochemistry and PCNA index.

Purification and characterization of a levanbiose-producing levanase from Pseudomonas sp. No. 43

A levanbiose-accumulating levanase from Pseudomonas sp. No. 43 was purified to a homogeneous state by (NH4)2SO4 fractionation and by chromatography on DEAE-Toyopearl 650 M and phenyl-Toyopearl 650 M columns. The molecular mass and isoelectric point of the enzyme were estimated to be 36 kDa and 5.7 respectively; the optimal pH and temperature for the enzyme reaction were pH 7.0 and 40 degrees C respectively. The purified enzyme was stable in the pH range 6.0-8.0 at 20 degrees C and stable up to 50 degrees C at pH 7.0. The enzyme's activity was inhibited by MnCl2, CoCl2, AlCl3, EDTA and potassium permanganate. The levanase was specific towards the 2, 6-beta-D-fructosidic linkages of levan and did not hydrolyse other polysaccharides among those examined. The enzyme is an exohydrolase of levan and produced levanbiose as a sole product; the limits of hydrolysis of levans from Zymomonas mobilis and Serratia sp. were 65% and 80% respectively.

Distribution of rantes and interleukin-5 in allergic nasal mucosa and nasal polyps

Eosinophil-chemoattracting cytokines are thought to be important in the pathogenesis of allergic inflammation. However, little is known about the presence and significance of RANTES in nasal allergy and nasal polyps, two well-known rhinologic disorders characterized by eosinophil infiltration in the tissue. In order to evaluate the role of RANTES in eosinophil infiltration in vivo, the tissue distributions of RANTES and interleukin-5 (IL-5) and their correlation with eosinophil infiltration were investigated. Nasal mucosa specimens were obtained from 9 allergic and 12 control subjects, and nasal polyps from 6 allergic and 9 nonallergic subjects. All the subjects were divided into 4 groups: normal mucosa, allergic mucosa, nonallergic polyps, and allergic polyps. To identify the cellular localizations of RANTES and IL-5, we used specific immunohistochemical staining. We also investigated the differences in cytokine expression among the 4 groups, and the correlation between cytokine expression and eosinophil infiltration in the tissue. RANTES was expressed in the epithelium, endothelium, and some submucosal cells, while IL-5 was confined to the cells in the submucosa. Expression of both RANTES and IL-5 significantly increased in allergic mucosa and nasal polyps compared to normal mucosa; however, there was no significant difference in their expression between allergic and nonallergic polyps. Both cytokines had a significant correlation between their expression and either total or activated eosinophil numbers. The results of this study suggest that RANTES, as well as IL-5, plays a role in eosinophil recruitment in allergic nasal mucosa and nasal polyps in vivo.

The nitric oxide-producing properties of Ulmi radicis cortex extract

We investigated the effect of Ulmi radicis cortex extract (UrCE) on the production of nitric oxide (NO). Stimulation of mouse peritoneal macrophages with UrCE after the treatment of recombinant interferon-gamma (rIFN-gamma) resulted in the increased NO synthesis. UrCE had no effect on NO synthesis by itself. When UrCE was used in combination with rIFN-gamma, there was a marked cooperative induction of NO synthesis in a dose-dependent manner. The optimal effect of UrCE on NO synthesis was shown 6 h after treatment with rIFN-gamma. NO production was inhibited by NG-monomethyl-L-arginine. The increased production of NO from rIFN-gamma plus UrCE-stimulated cells was decreased by the treatment of protein kinase C inhibitor such as staurosporin. In addition, synergy between rIFN-gamma and UrCE was mainly dependent on UrCE-induced tumor necrosis factor-alpha (TNF-alpha) secretion. All the preparations of UrCE were endotoxin free. These results suggest that the capacity or UrCE to increase NO production from rIFN-gamma-primed mouse peritoneal macrophages is the result of UrCE-induced TNF-alpha secretion.

T cell subsets in chronic hepatitis B and the effect of prednisolone withdrawal and interferon alpha-2b

OBJECTIVES

The evaluations of the pathogenetic roles of cell mediated immunity and of the preventive effect for disease progression with interferon(IFN) treatment in patients with chronic active hepatitis-B(CAH-B) are the objectives of this study.

METHODS

Thirty-two patients with CAH-B were treated with interferon alpha-2b(IFN alpha-2b) with prednisolone withdrawal and 30 control patients were treated with conventional hepatotonics for 6 months. Peripheral total T cell fractions and T cell subsets of the patients with CAH-B, treated with IFN alpha-2b with prednisolone withdrawal, were examined 1 month before administration of prednisolone, and compared with 12 normal controls for assessing the potential role of cellular immunity in the development of CAH-B. To estimate the effectiveness of IFN therapy for the patients with CAH-B, levels of various liver function tests, HBsAg, anti-HBs, HBeAg, anti-HBe, HBV DNA, anti-HCV and others were assessed for the treatment group and compared with control patients at pre- and post-treatment period each.

RESULTS

The value of CD4 was significantly lower in patients with CAH-B than normal controls (36.3 +/- 7.7% vs 42.1 +/- 5.7%, p < 0.05) and the value of CD8 was significantly higher in patients with CAH-B than normal controls (30.6 +/- 10.3% vs 24.3 +/- 5.2%, p < 0.05) before prednisolone administration. The patients in responder group (n = 26) had significantly lower CD4 cells compared with normal controls, but non-responders (n = 6) did not have. The levels of liver function test(LFT) in the patients with IFN alpha-2b treatment with prednisolone withdrawal were not different from the control patient group at pretreatment, but significantly lower than control patient group's after treatment, regardless of response to IFN alpha-2b treatment with prednisolone withdrawal.

CONCLUSIONS

The cellular immunity of the host may have a potential role in the pathogenesis of chronicity of hepatitis B infection. IFN alpha-2b treatment with prednisolone withdrawal may be regarded as one of the effective treatment modalities for the inhibition of disease progression in patients with CAH-B.

Purification and characterization of a novel levanoctaose-producing levanase from Pseudomonas strain K-52

Levan-assimilating micro-organisms from soil samples were screened for levanoligosaccharide-generating enzyme production. The isolated strain K-52 produced an extracellular levanoctaose-generating enzyme and was identified as belonging to genus Pseudomonas. The levanase was purified to homogeneity by (NH4)2SO4 fractionation and successive column chromatography on DEAE-cellulose, phenyl-Toyopearl 650 M, Sephadex G-100 and hydroxyapatite. The molecular mass of the enzyme was estimated as approx. 38 kDa by both SDS/PAGE and gel filtration, and its isoelectric point was approx. pH 4.8. The optimum temperature and pH for the enzyme reaction were 35 and 7.0 respectively. The enzyme was stable at a pH range of 6.0-9.0 at 4 degrees C and up to 40 degrees C at pH 6.8. The enzyme activity was inhibited by Fe2+, Cu2+, Hg2+ and Ag2+. The levanase was specific toward 2,6-beta-D-fructosidic linkages of levan and did not hydrolyse other polysaccharides such as inulin and dextran. Chemical modification on the levanase suggested that cysteine and histidine residues are essential for enzyme activity. The levanoctaose liberated by levanase reaction was used selectively only by the intestinal beneficial micro-organisms, such as Bifidobacterium and Lactobacillus spp.

Chaperone-like function of lipocortin 1

Lipocortin 1 (LC1) is a 37 kDa member of the annexin family of proteins. It has been proposed to act as a mediator of some of the actions of glucocorticoids in anti-inflammatory and immune suppressive functions. LC1 has been shown to play a role in cell proliferation, apoptosis, and differentiation. However, the exact biological functions of LC1 still remain obscure. Here it is shown that LC1 displays a chaperone-like function. Stoichiometric amounts of LC1 suppressed thermally induced inactivation and aggregation of the test enzymes citrate synthase and glutamate dehydrogenase. LC1 was also effective in refolding guanine hydrochloride-denatured glutamate dehydrogenase, as judged by circular dichroism spectroscopy.

Lipocortin 1 binding sites on human T-cells: the population of cells with the binding sites is larger in CD8+ T-lymphocytes than in CD4+ T-lymphocytes

Lipocortin 1 (LC1) is believed to be a mediator of glucocorticoids in displaying anti-inflammatory and immune suppressive responses. The existence of specific LC1 binding sites (putative receptor) on monocytes and neutrophils has been reported. We have studied the distribution of LC1 binding sites in human peripheral blood leukocytes by flow cytometry. The population of cells with LC1 binding sites was much larger in monocytes than in lymphocytes in both rheumatoid arthritis patients (93.1 +/- 2.3% vs 8.8 +/- 1.0%) and healthy volunteers (97.0 +/- 0.9% vs 9.9 +/- 1.5%). The LC1 binding cell population was larger in CD8+ T-lymphocytes than in CD4+ T-lymphocytes in both healthy volunteers (26.4 +/- 4.5% vs 10.6 +/- 2.0%) and rheumatoid arthritis patients (28.8 +/- 4.7% vs 8.7 +/- 2.1%). No difference in LC1 binding cell populations was found between rheumatoid arthritis patients and healthy controls.

Bioflocculant produced by Aspergillus sp. JS-42

A bioflocculant from a fungus, Aspergillus sp. JS-42, was purified by precipitations with acetone and cetylpyridinium chloride. The flocculating activity was not significantly affected by pH from 3 to 8, but was stimulated by the addition of CaCl2, and was effective only when the reaction mixture contained an adequate amount of flocculant. The flocculant could efficiently flocculate all tested solids suspended in aqueous solution, including various microorganisms, organic acids, and inorganic materials.