Antimicrobial activity of sodium citrate against Streptococcus pneumoniae and several oral bacteria

AIMS

The aim of this study is to assess the antibacterial activity of sodium citrate against Streptococcus pneumoniae and several oral bacteria.

METHODS AND RESULTS

The antibacterial activity was determined by broth microdilution method. The results showed that although Enterocuccus faecium OB7084 and Klebsiella pneumoniae OB7088 had high tolerance to sodium citrate, several oral bacteria including Fusobacterium nucleatum JCM8532(T) , Streptococcus mutans JCM5705(T) and Strep. pneumoniae NBRC102642(T) were susceptible. Furthermore, the bactericidal activity of sodium citrate against Strep. pneumoniae NBRC102642(T) was not influenced by pH in the range of 5·0-8·0, whereas that of sodium lactate was weakened at neutral or weak alkaline pH. When Strep. pneumoniae NBRC102642(T) was treated with sodium citrate for 2 h, many burst cells were observed. However, addition of MgCl(2) or CaCl(2) to an assay medium weakened the antimicrobial activity although ZnCl(2) or MnCl(2) did not influence.

CONCLUSIONS

Independent of pH, sodium citrate inhibited the growth of oral bacteria, which suggests that the mechanism is different from that of sodium lactate.

SIGNIFICANCE AND IMPACT OF THE STUDY

The results presented in this study would be available for understanding the antimicrobial property of sodium citrate.

Bacterial interactions in dental biofilm development

Recent analyses with ribosomal RNA-based technologies have revealed the diversity of bacterial populations within dental biofilms, and have highlighted their important contributions to oral health and disease. Dental biofilms are exceedingly complex and multispecies ecosystems, where oral bacteria interact cooperatively or competitively with other members. Bacterial interactions that influence dental biofilm communities include various different mechanisms. During the early stage of biofilm formation, it is known that planktonic bacterial cells directly attach to surfaces of the oral cavity or indirectly bind to other bacterial cells that have already colonized. Adherence through co-aggregation may be critical for the temporary retention of bacteria on dental surfaces, and may facilitate eventual bacterial colonization. It is likely that metabolic communication, genetic exchange, production of inhibitory factors (e.g., bacteriocins, hydrogen peroxide, etc.), and quorum-sensing are pivotal regulatory factors that determine the bacterial composition and/or metabolism. Since each bacterium can easily access a neighboring bacterial cell and its metabolites, genetic exchanges and metabolic communication may occur frequently in dental biofilms. Quorum-sensing is defined as gene regulation in response to cell density, which influences various functions, e.g., virulence and bacteriocin production. In this review, we discuss these important interactions among oral bacteria within the dental biofilm communities.

Reduction of vitamin K concentration by salivary Bifidobacterium strains and their possible nutritional competition with Porphyromonas gingivalis

AIMS

To assess the possibility that bifidobacteria compete with Porphyromonas gingivalis for their mutual growth factor vitamin K. This study also examined whether salivary Bifidobacterium species decrease vitamin K concentration in the growth medium.

METHODS AND RESULTS

Sixty-five strains of Bifidobacterium were obtained from 20 of 24 periodontally healthy subjects. Bifidobacterium dentium was most frequently detected in the saliva of subjects, followed by Bifidobacterium adolescentis, Bifidobacterium longum, and Bifidobacterium urinalis. The growth of most Bifidobacterium isolates, except that of B. urinalis, was stimulated by vitamin K. Moreover, the isolates were capable of decreasing vitamin K after incubation, which suggests that bifidobacteria compete with P. gingivalis for vitamin K. In a co-culture, a representative strain -B. adolescentis S2-1 - inhibited the growth of P. gingivalis if it was inoculated in the medium before P. gingivalis.

CONCLUSIONS

B. adolescentis S2-1 decreased vitamin K concentration and inhibited the growth of P. gingivalis by possibly competing for the growth factor.

SIGNIFICANCE AND IMPACT OF THE STUDY

Salivary bifidobacteria may possess the potential to suppress the growth of P. gingivalis by reducing the growth factor(s) in the environment.

Quantitative measurement of tetrahydromenaquinone-9 in cheese fermented by propionibacteria

Propionibacteria produce tetrahydromenaquinone-9 [MK-9 (4H)] as a major menaquinone (vitamin K2). This study aimed to determine the MK-9 (4H) concentration in commercial propionibacteria-fermented cheese. The MK-9 (4H) concentration was quantified using an HPLC instrument with a fluorescence detector after postcolumn reduction. Among the various cheese samples, the MK-9 (4H) concentration was highest in Norwegian Jarlsberg cheese, followed by Swiss Emmental cheese. In contrast, the MK-9 (4H) concentrations in Appenzeller or Gruyère cheeses were extremely low or undetected. Likewise, the concentrations in Comte and Raclette cheeses were lower than those in Jarlsberg and Emmental cheeses. In the present study, the MK- 9 (4H) concentration in cheese showed a correlation with the viable propionibacterial cell count and propionate concentration. This implies that the increase in propionibacteria contributed to the generation of MK-9 (4H) in cheese. We presumed, based on these results, that Swiss Emmental and Norwegian Jarlsberg cheeses contain a meaningful amount of vitamin K because of their high MK-9 (4H) concentrations (200 to 650 ng/g).

A new water-soluble N-protecting group, 2-(phenyl(methyl)sulfonio)ethyloxycarbonyl tetrafluoroborate, and its application to solid phase peptide synthesis in water

A new water-soluble N-protecting group, 2-[phenyl(methyl)sulfoniolethyloxycarbonyl tetrafluoroborate, has been prepared and its application to solid phase peptide synthesis in water has been studied. Leu-enkephalin amide was successfully synthesized in water by the solid phase method using this protecting group.

Amino acids and peptides. Part 39: A bivalent poly(ethylene glycol) hybrid containing an active site (RGD) and its synergistic site (PHSRN) of fibronectin

Fibronectin contains the active sequence Arg-Gly-Asp (RGD), along with its synergic site Pro-His-Ser-Arg-Asn (PHSRN). However, the PHSRN peptide does not show synergic activity when it is mixed with the RGD peptide, indicating that a spatial array between RGD and PHSRN in fibronectin may be necessary for synergic activity. Here, we have used an amino acid type poly(ethylene glycol) derivative (aaPEG) to design a bivalent PEG hybrid of fibronectin active peptides. We prepared the aaPEG hybrid peptides PHSRN-aaPEG, aaPEG-RGD, and PHSRN-aaPEG-RGD, and tested their biological activity. Whereas aaPEG-RGD promoted cell spreading activity, PHSRN-aaPEG had no activity. The PHSRN-aaPEG-RGD hybrid strongly promoted cell spreading compared with aaPEG-RGD. These results suggest that the PHSRN sequence in the PHSRN-aaPEG-RGD molecule synergistically enhances the cell spreading activity of the RGD sequence, and that the bivalent aaPEG hybrid method may be useful for conjugating functionally active peptides.

Amino acids and peptides. XXXVIII. Facile synthesis of laminin-related peptide-poly(ethylene glycol) hybrids by the solid phase method

Poly(ethylene glycol) (PEG) has been studied as a drug-carrier for proteins, but not for small peptides. Laminin, a cell adhesive protein, has Tyr-Ile-Gly-Ser-Arg (YIGSR) sequence and peptides containing this sequence inhibit experimental metastasis. We have studied PEG hybrids of YIGSR and other small laminin-related peptides. In a previous paper, we reported preparation of YIGSR-PEG hybrids by combination of the solid phase method and the solution method, but the synthetic procedure was problematic. Here we report a facile synthesis of PEG hybrids of YIGSR (PEG-YIGSR, YIGSR-PEG, PEG-YIGSR-PEG) by the solid phase method.

Preclinical in vivo antitumor efficacy of nedaplatin with gemcitabine against human lung cancer

The antitumor efficacy of the combination of nedaplatin (NDP) with gemcitabine (GEM) was evaluated. We also compared the antitumor activity of NDP plus GEM with that of cisplatin (CDDP) plus GEM or carboplatin (CBDCA) plus GEM. Ma44, which is a human lung cancer sensitive to GEM, and NCI-H460, which is a human lung cancer refractory to GEM, were used in this study. GEM was injected i.v. once followed by i.v. injection of NDP at an interval of approximately 30 min into tumor-bearing athymic mice. GEM was administered again 3 or 4 days thereafter. Combined dosing of NDP with GEM resulted in synergistically enhanced inhibition of tumor growth in the Ma44 tumor model. NDP plus GEM was also effective against Ma44 cells when given late in the therapy, a model for advanced disease. Potent augmentation of growth inhibition by NDP with GEM was also found with the NCI-H460 tumor model. The combination effect of NDP plus GEM appeared to be superior to that of CDDP plus GEM or CBDCA plus GEM in both tumor models. Toxicity in terms of blood cell numbers was not enhanced by the combination of NDP with GEM. These results suggest the effectiveness of combination of NDP with GEM for clinical therapy.

Amino acids and peptides. XXXV. Facile preparation of p-nitroanilide analogs by the solid-phase method

p-Nitroanilides of amino acids and peptides are widely used as the chromogenic substrates for the determination of the activity of proteolytic enzymes. However, the preparation of a p-nitroanilide is not easy, in part due to the low nucleophilicity of the amino group of p-nitroaniline. A facile preparation of p-nitroanilide analog by the solid-phase method was investigated. 5-Amino-2-nitrobenzoic acid (Anb5,2) was used instead of p-nitroaniline (pNA) for preparation of p-nitroanilide analogs. Anb5,2 was introduced on a p-methylbenzhydrylamine resin without protection of the amino group of Anb5,2 by the 2-(H-benzotriazol-1-yl)-1,1,3,3-tetramethyluronium tetrafluoroborate (TBTU) method in the presence of p-dimethylaminopyridine. The coupling reaction of a Nalpha-,NG-protected arginine with a Anb5,2-resin was difficult to achieve by common coupling methods (such as the carbodiimide and diphenylphosphoryl azide methods), but the phosphoryl chloride method was relatively successful. Synthetic benzoyl-Arg-Anb5,2-NH2 and benzoyl-Arg-pNA were hydrolyzed by trypsin and the both reaction mixtures exhibited same spectroscopic characteristics. H-D-Val-Leu-Arg-Anb5,2-NH2, an analog of human urine kallikrein substrate, was readily prepared by the solid-phase method. H-Arg-Anb5,2-OH and H-D-Val-Leu-Arg-Anb5,2-OH were also synthesized on a Wang resin by the solid-phase method. The aqueous solubility of these free-carboxyl materials was better than those of the corresponding amide analogs. 4-Amino-3-nitrobenzoic acid (Anb4,3) was also introduced on the p-methybenzhydrylamine resin, but the resulting H-Anb4,3-resin did not react with Nalpha,NG-protected arginine by any of the coupling methods.

Facile synthesis of a chitosan hybrid of a laminin-related peptide and its antimetastatic effect in mice

Laminin, a cell adhesion protein, consists of three peptide chains (alpha-1, beta-1 and gamma-1). The beta-1 chain contains a Tyr-Ile-Gly-Ser-Arg (YIGSR) sequence that has been found to inhibit experimental metastasis in mice. We have prepared a hybrid of a water-soluble chitosan and a laminin-related peptide, and have examined its inhibitory effect on experimental metastasis in mice. A laminin-related peptide, acetyl-Tyr-Ile-Gly-Ser-Arg-betaAla-OH (Ac-YIGSRbetaA-OH), was prepared by a solid-phase method. Ac-YIGSRbetaA-OH was then reacted with a water-soluble chitosan. BetaAla is a spacer and was placed to avoid racemization of the Arg residue when the peptide was coupled with chitosan. Although chitosan has amino groups, they did not react with the peptide. Four methods were tried to achieve a coupling reaction, the diphenylphosphoryl azide method, the diisopropylcarbodiimide/1-hydroxybenzotriazole method, the water-soluble carbodiimide (WSC), and the 2-(1H-benzotriazole-1-yl)-1,1,3,3-tetramethyluronium tetrafluoroborate (TBTU) method, but all four methods were unsuccessful. Therefore, a small spacer, tert-butyloxycarbonyl-Gly, was intercalated in chitosan, by the TBTU method, to facilitate its coupling with the peptide. After removal of the protecting group, the Gly-chitosan was coupled with Ac-YIGSRbetaA-OH by the water-soluble carbodiimide method to give Ac-YIGSRbetaAG-chitosan. Conjugation of the peptide with the larger chitosan molecule did not reduce the inhibitory effect of the peptide on experimental metastasis in mice, it actually potentiated the antimetastatic effect, demonstrating that chitosan may be effective as a drug carrier for peptides.

[Antiangiogenic and antitumor effect of BPHA, an orally-active matrix metalloproteinase inhibitor, in in vivo murine and human tumor model]

We examined the antiangiogenic and antitumor efficacy of a newly-developed matrix metalloproteinase (MMP) inhibitor, BPHA (N-biphenyl sulfonyl-phenylalanine hydroxiamic acid). BPHA potently inhibits MMP-2, 9 and 14 but not MMP-1, 3 or 7. In contrast, (-)BPHA, an enantiomer of BPHA, was inactive against all MMP tested. Daily oral administration of BPHA in mice resulted in potent inhibition of tumor-induced angiogenesis, primary tumor growth and liver metastasis, whereas (-)BPHA did not. These results demonstrate that selective MMP inhibition is correlated with antiangiogenic and antitumor efficacy and that the selective MMP inhibitor BPHA has therapeutic potential without hematotoxic effect or loss of body weight.

Suppression of oncogenic transformation by hypothemycin associated with accelerated cyclin D1 degradation through ubiquitin-proteasome pathway

Hypothemycin was originally isolated as an antifungal metabolite of Hypomyces trichothecoides. Here we report that treatment on v-K-ras-transformed NIH3T3 cells (DT cells) with hypothemycin caused drastic decrease in amount of cyclin D1 protein with concomitant prolongation of G1 phase in their cell cycle. Analysis using hypothemycin-resistant mutant of Schizosaccharomyces pombe (S. pombe) was carried out to show that S. pombe rhp6+ (homologue of Saccharomyces cerevisiae RAD6) and mammalian ubiquitin-conjugating enzyme 2 (ubc2) are the targets of hypothemycin or its downstream molecules in ubiquitin-conjugation process. Furthermore, in the presence of lactacystin, a specific inhibitor for proteasome, hypothemycin greatly enhanced the accumulation of multi-ubiquitinated form of cyclin D1 in DT cells. Therefore, it is indicated that hypothemycin facilitates ubiquitinating process of cyclin D1. In terms of malignant phenotype, hypothemycin inhibited anchorage-independent growth and reverted the morphology of DT cells. On the contrary, their morphology still remained transformed in the additional presence of lactacystin. Our results suggest that cyclin D1 is a key molecule working downstream in ras-signaling and that the transformation can be inhibited by the compound which can activate ubiquitin-proteasome pathway including degradation of cyclin D1.

Hereditary sensory neuropathy with deafness and dementia: a clinical and neuroimaging study

We describe three sibling patients with autosomal dominantly inherited sensory neuropathy, sensorineural hearing loss and dementia. The features of cognitive-behavioral deficits in the patients, including executive dysfunction, apathy, indifference and inattention, were consistent with a frontal lobe dysfunction. Magnetic resonance imaging showed a diffuse brain atrophy. A fluorodeoxyglucose positron emission tomography in one patient and a single photon emission computed tomography in another demonstrated a glucose hypometabolism or a hypoperfusion in the medial frontal and thalamic regions. Primary frontal involvement or frontal dysfunction secondary to thalamic lesions may contribute to the nature of dementia in these patients.

Blood biochemical characteristics, cecal microbiota and short-chain fatty acid composition in fistula implanted rats

We raised an experimental rat implanted with a cecal fistula and investigated various characteristics of fistula-implanted rats. Male F344/N Sic rats at 14 weeks of age were divided into three groups, the fistula group (n = 5) which consisted of fistula-implanted rats, the sham group (n = 7) which consisted of sham-operated rats, and the control group (n = 7) which were not subjected to any surgical procedure. Four weeks after the fistula implantation surgery, we compared the blood biochemical indices, the microflora composition and the short-chain fatty acids (SCFA) concentration in cecal contents of fistula-implanted rats with those of sham-operated and control rats. The blood albumin concentration of the fistula group was significantly lower than that of the sham group and the control group, and the hematocrit value of the fistula group was significantly lower than that of the control group, but there were no significant differences in the SCFA concentration and the microflora composition among these three groups. In conclusion, it was considered that the fistula-implanted rats are useful for taking cecal contents and determining the microflora composition and the metabolites concentration at any time, without disturbing the physiological functions of the intestinal tract.

Correlation of antiangiogenic and antitumor efficacy of N-biphenyl sulfonyl-phenylalanine hydroxiamic acid (BPHA), an orally-active, selective matrix metalloproteinase inhibitor

The antiangiogenic activity and antitumor efficacy of a newly developed matrix metalloproteinase (MMP) inhibitor were examined. N-biphenyl sulfonyl-phenylalanine hydroxiamic acid (BPHA) potently inhibits MMP-2, -9, and -14, but not MMP-1, -3, or -7. In contrast, (-)BPHA, an enantiomer of BPHA, was inactive against all MMPs tested. Daily oral administration of 200 mg/kg BPHA, but not (-)BPHA in mice resulted in potent inhibition of tumor-induced angiogenesis, primary tumor growth, and liver metastasis. The growth inhibition activity of BPHA was 48% and 45% in a B16-BL6 melanoma and F2 hemangio-endothelioma model, respectively. BPHA also showed 42% inhibition of the liver metastasis of C-1H human colon carcinoma cells. These results indicate that selective MMP inhibition is correlated with antiangiogenic and antitumor efficacy and that the selective MMP inhibitor BPHA has therapeutic potential.

Amyloid beta protein (25-35) phosphorylates MARCKS through tyrosine kinase-activated protein kinase C signaling pathway in microglia

Myristoylated alanine-rich C kinase substrate (MARCKS) is a widely distributed specific protein kinase C (PKC) substrate and has been implicated in membrane trafficking, cell motility, secretion, cell cycle, and transformation. We found that amyloid beta protein (A beta) (25-35) and A beta (1-40) phosphorylate MARCKS in primary cultured rat microglia. Treatment of microglia with A beta (25-35) at 10 nM or 12-O-tetradecanoylphorbol 13-acetate (1.6 nM) led to phosphorylation of MARCKS, an event inhibited by PKC inhibitors, staurosporine, calphostin C, and chelerythrine. The A beta (25-35)-induced phosphorylation of MARCKS was inhibited by pretreatment with the tyrosine kinase inhibitors genistein and herbimycin A, but not with pertussis toxin. PKC isoforms alpha, delta, and epsilon were identified in microglia by immunocytochemistry and western blots using isoform-specific antibodies. PKC-delta was tyrosine-phosphorylated by the treatment of microglia for 10 min with A beta (25-35) at 10 nM. Other PKC isoforms alpha and epsilon were tyrosine-phosphorylated by A beta (25-35), but only to a small extent. We propose that a tyrosine kinase-activated PKC pathway is involved in the A beta (25-35)-induced phosphorylation of MARCKS in rat microglia.

Pre-operative chemoradiation therapy with 5-fluorouracil and low-dose daily cisplatin for esophageal cancer: a preliminary report

BACKGROUND

A combination of chemotherapy and radiotherapy (chemoradiation therapy; CRT) has recently been developed to improve the survival of esophageal cancer patients. However, the optimal choice of chemotherapeutic agents and their doses, as well as chemotherapy and radiotherapy regimens, remain unclear.

METHODS

Based on recent advances in knowledge on the radiosensitizing and biochemical modulation effects of chemotherapeutic agents, we have recently developed concurrent CRT which consisted of continuous 5-fluorouracil (5FU) administration (600 mg/m2/day, days 1-5) combined with a low dose of daily cisplatin administration (10 mg/m2/day, days 1-5, and 5 or 10 mg/m2/day, days 8-12 and 15-19) before each fraction of radiation (2 Gy each). To evaluate the efficacy and safety of our concurrent CRT, 10 esophageal cancer patients received one or one and a half courses of the CRT.

RESULTS

All patients tolerated and completed a full course of the CRT. The effectiveness of the CRT on the primary tumor included pathologically or endoscopically complete responses in three patients (30%), partial response in five (50%), no response in two (20%) and tumoral downstaging (T-classification) in five (50%). Grade 2 and Grade 3 toxicity, seen in six patients, did not affect surgical operation. No patients showed CRT-related deaths. Eight patients (80%) underwent resection with no operative mortality. Of these, two patients (25%) showed pathologically or endoscopically complete responses, and four (50%) showed partial response. Three patients died of cancer after resection. The two inoperable patients showed a pathologically complete response and partial response, respectively. They were relieved of their cancer-related complaints and were living without hospitalization at the time of this analysis.

CONCLUSIONS

These results suggest that the concurrent CRT based on the theoretical backgrounds is effective and has acceptable toxicities with maintaining its efficacy for the treatment of esophageal cancer patients.

Regioselective conjugation of chitosan with a laminin-related peptide, Tyr-Ile-Gly-Ser-Arg, and evaluation of its inhibitory effect on experimental cancer metastasis

A conjugate from the YIGSR peptide and chitosan has been prepared on the basis of a regioselective modification strategy of chitosan, and its antimetastatic activity has been assayed. Chitosan was converted to its organosoluble derivative, 6-O-trityl-chitosan, in 3 steps, and then coupled with the peptide portion containing a spacer amino acid, Ac-Tyr-Ile-Gly-Ser-Arg-beta Ala-OH [beta Ala; beta-alanine]. The product was treated with CHCl2CO2H to afford the desired conjugate, Ac-Tyr-Ile-Gly-Ser-Arg-beta Ala-chitosan, which proved to inhibit the experimental lung metastasis of B16BL6 melanoma cells in mice at lower doses than the parent peptide.

Complete response of esophageal cancer achieved by combination therapy with 5-fluorouracil, low-dose cisplatin, and radiation: report of a case

To improve the survival rate of patients with esophageal cancer, several protocols of a preoperative combination of chemotherapy and radiotherapy, known as chemoradiation therapy, have been developed, recently characterized by the combination of 5-fluorouracil (5-FU), cisplatin, and radiation. Although some of these combinations have been demonstrated to be effective, the optimal chemoradiation dose and schedule are not yet precisely established. Recent investigations have elucidated that the radiosensitizing effects of cisplatin are able to be achieved more effectively by the daily administration of cisplatin before each fraction of radiation. Based on these investigations, we report herein the case of a patient with esophageal cancer with direct invasion to the trachea, in whom a complete response was achieved by the continuous administration of 5-FU, 600 mg/m2 per day, from days 1-5 combined with the daily administration of low-dose cisplatin, 10 mg/m2 per day before each fraction of radiation, given as 2Gy each time, throughout the entire treatment period of 3 weeks beginning on day 1. The benefits of our preoperative chemoradiation therapy included no severe side effects, down-staging and resectability of the tumor, as well as a pathological complete response, which could prolong the survival time. Our experience of this case prompts us to recommend the concurrent daily preoperative chemoradiation therapy for patients with locally advanced esophageal cancer.

[Augmented antitumor efficacy of combination chemotherapy of nedaplatin with 5-fluorouracil in in vivo murine and human tumor model]

Augmented antitumor activity was demonstrated in combination chemotherapy of Nedaplatin (NDP) or Cisplatin (CDDP) with 5-fluorouracil (5-FU) against murine lung carcinoma and human squamous carcinoma from head and neck. Either NDP or CDDP (1/4 to 1 maximum tolerated dose; MTD) was injected once and 5-FU (1/16 MTD) was injected daily for five days via tail vein to tumor-implanted mice. The sequential administration of either NDP or CDDP prior to 5-FU (NF or CF therapy) showed severe body weight loss followed by the toxic death of tumor-bearing mice at the MTD of NDP or CDDP. In contrast, the reverse sequence of the treatment, that is, 5-FU prior to NDP or CDDP (FN or FC therapy), resulted in the synergistically enhanced inhibition of tumor growth and the prolonged survival in comparison with NDP, CDDP or 5-FU monotherapy. The antitumor activities of the combinations of CDDP with 5-FU was less than those of the combination of NDP with 5-FU. Especially, at the MTD of NDP in FN therapy, long-term tumor-free survival was frequently observed. Thus, FN therapy was thought to be the most efficient regimen in combination of NDP with 5-FU as a clinical therapy.

PKC and tyrosine kinase involvement in amyloid beta (25-35)-induced chemotaxis of microglia

Microglia are activated by amyloid beta (Abeta) in vivo and in vitro, and Abeta-activated microglia may be involved in the pathogenesis of Alzheimer's disease (AD). We investigated the mechanism of microglial chemotaxis induced by Abeta (25-35), an active fragment of Abeta. Abeta (25-35) 0.1 and 1 nM stimulated microglial chemotaxis. The protein kinase C (PKC) inhibitors chelerythrine (0.5 and 2 microM), calphostin C (1 microM) and staurospine (10 nM) significantly inhibited the microglial chemotaxis induced by Abeta (25-35) (1 nM). The chemotactic effect of Abeta (25-35) on microglia was desensitized by pretreatment of microglia with 1 ng/ml 12-O-tetradecanoylphorbol 13-acetate (TPA). Pretreatment of cells with Abeta (25-35) (1 nM) also desensitized the chemotactic effect by Abeta (25-35) (1 nM). The desensitization by TPA or Abeta (25-35) was inhibited when staurosporine was present in the pretreatment media. The tyrosine kinase inhibitor herbimycin A (0.1 and 1 microM) significantly inhibited the microglial chemotaxis induced by Abeta (25-35) (1 nM). Based on these observations, it seems likely that PKC and tyrosine kinase are involved in the Abeta-induced chemotaxis of microglia.

Sequence-dependent antitumour efficacy of combination chemotherapy of nedaplatin, a novel platinum complex, with 5-fluorouracil in an in vivo murine tumour model

The antitumour efficacy of a sequential combination of nedaplatin (NDP) and 5-fluorouracil (5-FU) was evaluated using Lewis lung carcinoma in vivo. NDP was developed as a second generation platinum complex. Because it has greater antitumour activity and lower nephrotoxicity than cisplatin (CDDP), we also compared the antitumour activity of NDP plus 5-FU with that of CDDP plus 5-FU. A fixed 5-FU dose was injected daily for 5 days and increasing doses of either NDP or CDDP were injected once via the tail vein into the Lewis lung carcinoma-implanted mice. The sequential administration of either NDP or CDDP prior to 5-FU (NF or CF therapy) resulted in severe body weight loss followed by the death of the tumour-bearing mice when the high-dose of NDP or CDDP was administered. In contrast, the sequential administration of 5-FU prior to NDP or CDDP (FN or FC therapy) resulted in synergistically enhanced inhibition of tumour growth and prolonged survival in comparison with NDP, CDDP or 5-FU monotherapy. At the high-dose of NDP in FN therapy, a reduction of tumour size and long-term tumour-free survival were frequently observed. The survival effect of the combinations of NDP with 5-FU was superior to those of the combination of CDDP with 5-FU. In conclusion, the sequence-dependent antitumour efficacy and toxicity of the combination of NDP or CDDP with 5-FU was demonstrated in this study, and FN therapy appeared to be the most efficient regimen as a clinical therapy.

A rare case of primary malignant mesothelioma originating from the rectovaginal tissue

A 35 year-old female patient with pelvic malignant mesothelioma is described. The patient underwent total pelvic exenteration due to a pelvic tumor. Macroscopically, the resected tumor was located in the rectovaginal lesion with invasion into the rectal and vaginal wall, and around the internal urethral ostium. Light microscopically, the tumor predominantly consisted of sheets of plump round cells with acidophilic cytoplasm, and focally of tumor cells showing papillary growth pattern. The tumor cells showed remarkable cellular pleomorphism, and were both alcian blue and periodic acid-Schiff stain negative. Electron microscopically, these tumor cells had numerous long bush-like microvilli on their surface with increased length/width ratios. Positive staining with epithelial membrane antigen, cytokeratin, and vimentin, and negative staining with the carcinoembryonic antigen and S-100 protein were observed immunohistochemically. Based on these histological and immunohistochemical estimations, the tumor was diagnosed as a primary malignant mesothelioma originating from the rectovaginal tissue. Review of the literature confirmed the rarity of pelvic malignant mesothelioma. The possibilities of the pathogenesis of the tumor include the tumor's arising from the peritoneal remnant in the rectovaginal tissues, or from the epithelium of the secondary Mullerian system, which shares the same ancestry with the peritoneum.

[Treatment strategy for cancer of the colorectum--difference with western approach]

In Japan, extensive radical surgery is used for advanced cancer, whereas in western countries the standard operative approach used in Japan 20-30 years ago is used, followed by rather aggressive adjuvant therapy-chemotherapy and irradiation therapy by medical oncologists. The results of the extensive radical operations performed in Japan, called the "Japanese operation," have drawn attention but hesitate to undertake for a big aggression; instead the TME proposed by Heald is gaining ground, although we don't appreciate it. In Japan, more and more cases are being discovered relatively early, and function preserve operations to preserve pelvic nerves, or EMR (endoscopic mucous resection) have been developed and are seeing progressively widespread application. Therapeutic results have been considered to have remained unchanged in the past 20-30 years in western nations, whereas they have much improved in Japan, mainly because of relatively earlier discovery in an increased number of cases and the progress in surgical techniques.

Anticancer efficacy in vivo and in vitro, synergy with 5-fluorouracil, and safety of recombinant methioninase

The elevated exogenous-methionine dependency of tumors for growth has been observed in all major cancer cell types. We have previously cloned a methioninase (rMETase) from Pseudomonas putida to deplete methionine. Growth inhibition followed by apoptotic cell death was induced by treatment of tumor cells with rMETase in vitro. A single i.p. injection of 300 units of rMETase can lower the serum methionine level in the mice from 70 microM to less than 1 microM within 2 h and maintain this depleted level for 8 h. Repeated dosing of rMETase of tumor-bearing mice could be administered without acute immune-hypersensitivity. rMETase treatment demonstrated growth inhibitory activity against human tumors in nude mice, including those which were multiple drug-resistant. No body weight loss or hematotoxicity, except a slight anemia, was found throughout the therapy. The combined treatment of the Lewis lung carcinoma with a fixed rMETase dose and increasing doses of 5-fluorouracil (5-FU) resulted in a dose-dependent enhanced antitumor efficacy for survival as well as tumor growth inhibition. Thus, methionine depletion by rMETase potentiates the antitumor efficacy of 5-FU. The data presented in this report thus indicate that rMETase is active alone, is synergistic in combination with 5-FU, and has negligible toxicity suggesting a novel clinical approach for effective cancer therapy.

[Chemotherapy of gastric cancer]

At present curative resection is the only radical treatment for gastric cancer, although recently developed combination chemotherapy shows increased activity in treating locally advanced and metastatic disease. Among several combination regimens, those based on biochemical modulation, such as sequential methotrexate/5-fluorouracil or low-dose CDDP/5-fluorouracil, are thought to provide increased efficacy with decreasing adverse reactions in unresectable gastric cancer. Therefore, a prospective randomized clinical trial comparing the prognosis of patients receiving adjuvant multi-agent chemotherapy with those treated only surgically should be pursued for estimation of the clinical benefit of these agents.

[Chemoradiation therapy for esophageal carcinoma]

Cancer of the esophagus poses a great challenge to the surgical, medical, and radiation professions. Despite standardization of resection and reconstruction techniques, extended lymph node dissection, and advances in perioperative management, the overall prognosis of patients with esophageal cancer undergoing surgical resection has not improved. Preoperative combination chemoradiation therapy in patients with squamous cell esophageal carcinoma has recently received increasing attention, because preoperative chemoradiation therapy, consisting of the concurrent combination of 5-fluorouracil, cis-platinum and radiation, appears to increase the resection rate, the rate of pathological complete responders, and survival time after esophagectomy in patients with locally advanced tumors. Overall in the trials using preoperative concurrent chemoradiotherapy, major antitumor responses have been reported in 40% to 80% of patients, and, consistently, up to 42.1% pathologic complete responses have been seen at esophagectomy. Therefore, preoperative chemoradiation therapy can be anticipated for better prognosis of the patients with locally advanced esophageal cancer.

[Sexual dysfunction following pelvic surgery]

In male, sexual dysfunction was a common complication that occurred after radical pelvic surgery: radical protectomy, radical cysto-, prostatectomy. Upon the recent pelvic neuroanatomical findings and preservation of these nerves, it is now possible to perform successful cancer operation on the rectum, prostate or bladder with preservation of sexual function in the group of early cancer patients. Depending on the location and severity of these nerve injury, this could result in temporary or permanent erectile and ejaculation dysfunction. In female, the total hysterectomy for cervical cancer sacrifices or injuries the faculty of pregnancy or sexual intercourse. The oophorectomies causes a deficiency of female hormones. But recently the numbers of patients with a small or early stages cancer of uterine or ovary are increasing and we have become to be able to save the functions of these organs in many patients well with minimum local excision or partial resection of them.

[Prospective controlled study on the usefulness of Carmofur as a postoperative adjuvant chemotherapy for colorectal cancer]

A prospective controlled study, the 7th cooperative study of the Japanese Foundation for Multidisciplinary Treatment, was conducted to evaluate the usefulness of concomitant therapy with MMC + HCFU as a postoperative adjuvant therapy in patients with colorectal cancer who had undergone curative resection for a period of 2 years and 11 months from February, 1986. The Dukes B and C patients with colorectal cancer classified by macroscopic examination who had an intravenous MMC 6 mg/m2 on the day of operation and followed by oral HCFU for 12 months from 2 weeks after operation (Group X) were compared with patients who had operation only (Group Y). Some 978 patients with colon cancer and 713 patients with rectal cancer were enrolled in the study, 85 (5.0%) of whom were not eligible. The 5-year survival rate of Group X in colon cancer was 79.3% and that of Group Y was 76.4%: thus the survival rate of Group X was slightly better than that of Group Y, but no significant difference was found between the two groups. Subset analysis revealed that the survival rate of Group X in advanced cancer of stage III b + IV, according to the General Rules for Clinical and Pathological Studies on Cancer of the Colon, Rectum and Anus in Japan, was 62.4% and that of Group Y was 46.2%. Thus, the survival rate of Group X was significantly better than that of Group Y (logrank test: p = 0.035, generalized Wilcoxon test: p = 0.025). The disease-free survival rate was not significantly different between the groups with colon cancer and rectal cancer. The above results suggest that HCFU is useful for patients with a high risk of recurrence who had advanced colon cancer (stage III b + IV). However, additional prospective studies are required to verify them.

Oxysterols found in opacified cornea of fish

We describe a new concept implicating oxidized cholesterol derivatives and very long-chain fatty acids as possible factors in the development of corneal opacification after death. Corneal tissues, removed from both fresh and stale fish eyes, were examined for cholesterol derivatives and fatty acids after methanolysis of lipids. Cholesta-3,5-dien-7-one, cholest-4-en-3-one, hexacosenoic acid, and hexacosenoic acid were identified via gas chromatography/mass spectrometry in opacified corneas, but not in significant amounts in fresh ones. The present study confirmed the presence of lipid hydrolysis and a peroxidation process in the opacified cornea.

Thymic nurse cells as the site of thymocyte apoptosis and apoptotic cell clearance in the thymus of cyclophosphamide-treated mice

Structural changes in the thymus of BALB/c mice after the intraperitoneal injection with a single high dose (200 mg/kg) of cyclophosphamide (CY) were examined. A large number of thymic nurse cell (TNC)-like structures that contained apoptotic thymocytes were observed in the thymus between 8 and 20 hours after CY treatment, just before a marked reduction in the number and proportion of PNAhi, CD3-, CD4+ CD8+ thymocytes. The majority of apoptotic thymocyte-containing TNC-like structures had an epithelial nature and were mainly located in the subcapsular and outer cortex, perivascular area of the cortex, corticomedullary junction and, in part, in the medulla. Most thymocytes seemed to undergo apoptosis synchronously in every TNC-like structure, but one or two fully intact mature thymocytes were found in every one. By 24 hours after CY treatment, many vacuoles that contained apoptotic cells in various stages of degeneration were observed within the epithelium, and most of the apoptotic cells disappeared at 24 hours. We herein demonstrated that the epithelium of TNC-like structures had a phagocytic activity in the digestion of apoptotic thymocytes by the presence of phagolysosomes with acid phosphatase activity. The epithelium left very small vacuoles with a small amount of nondigestible dense granules. The minority of apoptotic thymocyte-containing TNC-like structures scattered in the entire cortex between 8 and 20 hours after CY treatment was macrophage (M phi)-derived. Many apoptotic cell-containing M phi were observed as early as 4 hours after the CY injection. Apoptotic thymocytes of CY-treated mice showed the internucleosomal DNA fragmentation. In conclusion, CY accelerates physiologic thymocyte apoptosis, and epithelial TNC are one of the principal sites of thymocyte apoptosis as well as an environment for the nursing of immature thymocytes. Both the epithelium of TNC and M phi participate in digestion of apoptotic cells and have the efficient capacity of clearance of apoptotic thymocytes in the normal thymus at a presumed high rate.

Identification of cholesta-3,5-dien-7-one by gas chromatography-mass spectrometry in the erythrocyte membrane of alcoholic patients

Lipids and oxidized lipids were analyzed by gas chromatography-mass spectrometry in the erythrocyte membranes of alcoholic and control subjects. Cholesta-3,5-dien-7-one and cholesta-trienes were detected in alcoholic samples examined, but not in significant amounts in controls. Levels of polyunsaturated fatty acids (arachidonic acid, 20:4; docosahexaenoic acid, 22:6; and docosatetraenoic acid, 22:4) in alcoholic samples declined significantly, whereas cholesta-3,5-dien-7-one levels increased. A high level of total bilirubin was observed in most patients. A possible mechanism of the accumulation of cholesta-3,5-dien-7-one in the erythrocyte membrane of alcoholics is discussed.

Reaction of 20S proteasome: shift of SDS-dependent activation profile by divalent cations

The multicatalytic endopeptidase complex (20S proteasome) is a latent high-molecular-mass multisubunit proteinase. In many investigations, SDS has been used as a proteasome activator at some fixed concentration that was apparently optimal. This study examined the effects of various divalent cations on the SDS-dependent peptidase and casein degradation activities of 20S proteasome purified from Xenopus laevis oocytes at a series of SDS concentrations and the correlation between these effects and the critical micelle concentration (CMC) of SDS. Surprisingly, it was found that divalent cations such as Mg2+ markedly shifted the SDS-dependent activation profiles to a lower concentration range. Ca2+, Mn2+, Co2+, and Zn2+ also markedly reduced the optimum SDS concentration in the Suc-Leu-Leu-Val-Tyr-MCA hydrolysis reaction: for example, 5 mM Co2+ reduced the optimum SDS concentration from 0.065 to 0.005%. However, in all cases examined the optimum concentrations were below the CMC. Cu2+, Hg2+, and Cd2+ strongly inhibited the SDS-dependent maximum activity without remarkably shifting the optimum SDS concentration. No correlation between the shift and the inhibition was recognized. Most interestingly, remarkable activation of casein degradation by SDS was observed only by addition of the divalent cations Mg2+, Ca2+, and Mn2+. These cations might be essential for casein degradation. The activation and inactivation ranges of SDS concentration varied with the species of substrate.(ABSTRACT TRUNCATED AT 250 WORDS)

Congenital myotonic dystrophy: molecular diagnosis and clinical study

Recently, an unstable DNA fragment specific to myotonic dystrophy (MyD) was discovered. In affected individuals, a DNA fragment is found that is larger than in normal siblings. Our objectives were to show whether the results of DNA analysis agree with the disease severity and prognosis in congenital myotonic dystrophy (CMyD) by DNA analysis. We investigated three pregnancies (two studied retrospectively) in three families. We genotyped the family members with the Southern blots and the polymerase chain reaction (PCR) analysis. In one case a prenatal diagnosis was carried out using chorionic villus sampling. This report also presents the three cases of affected mothers and CMyD babies with their growth courses. We clarify four main problems in CMyD, namely, respiratory distress, delayed motor development, feeding difficulty, and delayed mental development. The allele size in the range of 10 to 13 kb tended to be present as the adult form of MyD, and 14 to 15 kb as the CMyD. The three CMyD cases whose alleles size in the range of 14 to 15 kb showed various forms of disease and prognosis. We reached the following conclusions: the disease severity and prognosis in babies with CMyD did not correlate with the result of DNA analysis. The DNA analysis is a useful test for prenatal diagnosis. However, it is impossible to predict the disease severity and prognosis in babies with CMyD.

Murine nursing thymic epithelial cell lines capable of inducing thymocyte apoptosis express the self-superantigen Mls-1a

Two cloned thymic epithelial cell (TEC) lines, D2.TEC-A3 and AKR TEC-K1, were established from minor lymphocyte-stimulating (Mls)-1a-positive normal, 4-week-old DBA/2 (H-2d, Mls-1a2a) mice and AKR (H-2k, Mls-1a2b) mice, respectively. Both cell lines were MHC class I and class II (both I-A and I-E) positive without stimulation by interferon-gamma. They were capable of infolding immature thymocytes to form thymic nurse cells (TNC; we call this type of TEC "nursing TEC") and induced apoptosis with DNA fragmentation in immature thymocytes. Using a primary Mls mixed lymphocyte reaction (MLR) we demonstrated that self-superantigen Mls-1a was expressed on these cloned nursing TEC lines. D2.TEC-A3 cells stimulated nylon-wool-purified splenic T cells obtained from H-2d-compatible BALB/c (Mls-1b2a) and B10.D2 (Mls-1b2b) mice with a maximal response at a stimulator:responder ratio of 1:40 after 4 days of the coculture. AKR TEC-K1 cells also stimulated purified T cells from H-2k-compatible C3H/He mice (Mls-1b2a) in a similar manner. The Mls MLR induced by the nursing TEC lines was completely inhibited in the presence of anti-mouse I-A and anti-mouse I-E monoclonal antibodies. These results suggest that nursing TEC/TNC could be involved in negative selection due to apoptosis.

[Chronological changes in autoantigenicity of autologous testicular germ cells in C3H/He mice during the postnatal period]

Our recent studies demonstrated that experimental autoimmune orchitis (EAO) model was produced in C3H/He mice with high incidence by two subcutaneous injections of viable syngeneic testicular germ cells (TC) without the use of any adjuvants or immunopotentiators. In this study the developmental patterns of autoantigenicity of TC during postnatal period were investigated by examining the orchitogenic activity of TC, the lymphostimulatory activities of TC (including the TC-induced in vitro lymphocyte proliferative response and the cytokine release from sensitized spleen cells (SPC) in response to TC) and the immunohistochemical localization of target autoantigens in the testes of mice at various weeks of age. Delayed-type hypersensitivity-inducing capacity and anti-TC antibody-eliciting capacity were initially observed in mice that were immunized with TC of 4-week old (w.o.) mice. The TC from 6-w.o. mice had the capability of inducing EAO (orchitogenicity) for the first time. A significant stimulation of in vitro lymphocyte proliferative response, as well as of interleukin (IL) 5 and IL-6 production by sensitized SPC were detectable when TC of mice 3-w.o. or more than were employed as stimulant. IL-2 and interferon gamma production were detected with TC of 4-w.o. mice. Immunohistochemical staining reaction with anti-TC antisera was primarily localized at the acrosomal portion of spermatids and spermatozoa in the seminiferous tubules, being already detected in spermatids of as early as 3-w.o. mice. Thus, from these data it is suggested that the appearance of the lymphostimulatory activities of TC consistently precedes that of the orchitogenic activity and that relatively mature germ cells such as spermatids and spermatozoa developing in the testes during the postnatal weeks may be responsible for the induction of disease and relevant immune responses in our EAO system.

An analysis on the effect of blood transfusion on recurrence and survival in patients undergoing extended lymphadenectomy for colorectal cancer

In a retrospective study data were collected from 644 patients with cancer of the colon or rectum undergoing curative surgery with extended lymphadenectomy to evaluate a possible effect of blood transfusion, given perioperatively, on tumor recurrence and patient survival. Univariate analysis showed depth of bowel wall invasion, number and level of lymph node metastases to be of highly significant prognostic factors. After 5 years the overall recurrence rate was 16.6% for the non-transfused (n = 223) and 26.1% for the transfused (n = 421; p < .01) patients, and survival rates showed borderline significance favoring the non-transfused patients (90.5% vs. 80.0% after 5 years; p < 0.05). However, after stratification for the prognostically important factors, in a multivariate analysis a possible detrimental effect of perioperative blood transfusions could not be demonstrated.

Generation and characterization of a continuous line of CD8+ suppressively regulatory T lymphocytes which down-regulates experimental autoimmune orchitis (EAO) in mice

We have previously shown that two injections with viable syngeneic testicular germ cells (TC) alone developed experimental autoimmune orchitis (EAO) in C3H/He mice, and that the induction of antigen-specific tolerance in this EAO model is associated with the generation of antigen-specific suppressively regulatory T (Ts) cells. For the elucidation of the nature of these Ts cells, a murine Ts cell line (designated Ts-A) was established. This line was generated from the spleen cells of C3H/He mice which had received three i.v. injections of a soluble (deaggregated) form of murine testicular antigen (mTA), followed by the repeated selection of these spleen lymphocytes in vitro by stimulation with mTA. Adoptive transfer of Ts-A cells into naive syngeneic mice immediately before the first TC injection was found to downgrade EAO in actively immunized recipients. The transferred Ts-A cells significantly inhibited the cellular immune response to TC in the recipients in an antigen-specific manner, but these cells had no inhibitory effect on the humoral immune response to TC. This line could also inhibit in vitro syngeneic TC-driven proliferation of orchitogenic lymphocytes. Surface phenotype of this line was CD8+, CD4-, Thy-1.2+, CD3+, and TCR alpha beta+. These findings may suggest an in vivo role for suppressively regulatory lymphocytes, capable of inhibiting helper T cells, in the regulation of EAO.

Murine experimental autoimmune orchitis (EAO) induced by syngeneic testicular germ cells (TC) alone: orchitogenic and lymphostimulatory activities of TC from mice at various ages

As part of our continuous investigations on the immune pathogenesis of a new experimental autoimmune orchitis (EAO) model without the use of adjuvant in C3H/He mice, the developmental patterns of autoantigenicity of viable syngeneic testicular germ cells (TC) during the postnatal period were investigated by examining the orchitogenic and immunogenic activities of TC, the lymphostimulatory activities of TC (the cytokine release from sensitized spleen cells (SPC) in response to TC), and the immunohistochemical localization of autoantigens in the testes of normal mice at various weeks of age. TC from 6-week-old mice had the capability of inducing EAO (orchitogenicity) for the first time. Delayed-type hypersensitivity-inducing capacity and anti-TC antibody-eliciting capacity were initially observed in mice immunized with TC from 4-week-old mice. A significant stimulation of interleukin 5 (IL-5) and interleukin 6 (IL-6) production by sensitized SPC was detectable when the TC from 3-week or older mice were employed as a stimulant. Interleukin 2 (IL-2) and interferon-gamma (IFN-gamma) production was detected with TC from 4-week or older mice. Immunohistochemical staining reaction with anti-TC antisera was primarily localized at the acrosomal portion of spermatids and spermatozoa in the seminiferous tubules and was detected in early and late spermatids of mice as early as 3 weeks. Thus, from these chronological data it is suggested that the appearance of the lymphostimulatory activities of TC consistently precedes that of the orchitogenic activity and that the production of IL-5 and IL-6 (Th 2 cytokine) by sensitized SPC upon in vitro TC stimulation is detectable earlier than the production of IL-2 and IFN-gamma (Th 1 cytokine) in the postnatal period.

Pattern of recurrence after hepatic resection for colorectal metastases

Between 1978 and 1989, 159 patients with liver metastases from colorectal cancer underwent hepatic resection. Of 134 patients in whom metastases were confined to the liver, 109 had tumours removed completely with histologically negative resection margins. Two patients died in hospital. Ultrasonographically guided partial resection was performed in 80 patients, lateral segmentectomy in seven and lobectomy in 22. The 5-year survival rate of patients undergoing potentially curative resection was 47.9 per cent. Patients with metachronous tumours showed a significantly better prognosis than those with synchronous lesions in both univariate (P < 0.01) and multivariate (P = 0.01) analysis. During a median follow-up of 35.4 months, 64 patients developed recurrence, including 34 in the liver, 20 in the lung and 12 in the abdominal cavity. Of those with hepatic recurrence, ten patients developed tumours at the initial resection bed, seven in the same lobe, five in the contralateral lobe and 12 in both lobes. Ultrasonographically guided partial liver resection did not increase the risk of hepatic recurrence.