Phloroglucinols from Baeckea frutescens

Two new phloroglucinols, named BF-1 and BF-2, were isolated from the dried leaves of Baeckea frutescens. Their structures were determined by their 1H and 13C NMR and mass spectral data. BF-2 exhibited strong cytotoxic activity (IC50 = 5.0 micrograms ml-1) against leukaemia cells (L 1210) in tissue culture.

Comparative fungicidal activity of a new quaternary ammonium salt, N-alkyl-N-2-hydroxyethyl-N,N-dimethylammonium butyl phosphate and commonly used disinfectants

We synthesized a new quaternary ammonium salt, N-alkyl-N-2-hydroxyethyl-N, N-dimethylammonium butyl phosphate (ABP) that does not precipitate in the presence of anionic surfactants by incorporating a paired butyl phosphate anion into cationic surfactants. ABP showed much greater bactericidal activities and antirusting effects than benzalkonium chloride (BAC). In this study, the fungicidal effects of ABP were evaluated in comparison with common disinfectants [BAC, chlorhexidine digluconate (CHX) and alkyldiaminoethylglycine hydrochloride (ADE)]. Fungicidal effects were evaluated in 10 strains of 6 fungal species, namely, 3 Candida albicans, 2 Candida tropicalis, 1 Candida parapsilosis, 1 Aspergillus niger, 2 Aspergillus terreus, and 1 Trichophyton rubrum. ABP and BAC showed the same effects on 2 C. tropicalis and C. parapsilosis, and similar effects on 3 C. albicans, with slight differences among the strains. ABP showed quick fungicidal effects against A. niger and 2 A. terreus of molds in 30 min at 0.1% and in 15 min at 0.2 and 0.4%, but BAC showed slow effects against A. niger at 1 h and 2 A. terreus at 30 min at 0.2 and 0.4%, respectively. There is one factor, which may have caused this difference: the former had a butyl phosphate anion and the latter had a chloride anion as a counter ion. BAC, CHX and ADE needed 24h to cause notable effects on A. niger at 0.1% and 1 h at 0.2%. The new synthetic anti-rust ABP is considered to have sufficient fungicidal effects that are comparable to those of BAC, CHX and ADE.

Therapeutic effects of glycyrrhizin in mice infected with LP-BM5 murine retrovirus and mechanisms involved in the prevention of disease progression

Glycyrrhizin (GL), a plant extract, has been evaluated for its inhibitory effect on HIV replication in vitro and for its improvement of clinical symptoms in HIV-infected patients. In this study, we used GL in a murine AIDS model (MAIDS) to evaluate these effects. C57BL/6 mice were inoculated with LP-BM5 murine leukemia virus to cause MAIDS. Treatment with GL supplemented with glycine and cysteine (Stronger Neo-Minophagen C, SNMC) was then begun on day 0 or 4 wks after virus inoculation. SNMC was administered three times a week for up to 19 wks. Immunological abnormalities were monitored with respect to the surface phenotype identified by two-color staining for CD3 and IL-2 receptor beta-chain. All mice infected with the virus alone developed MAIDS and died by 14 wks after infection. The immunopathogenesis was estimated to be an abnormal expansion of intermediate CD3 cells (i.e., extrathymic T cells) as well as other types of lymphocytes. SNMC did not change the total mortality rate. However, some mice that began the treatment on day 0 or 4 wks after infection survived 3 wks longer. Splenomegaly and lymphadenopathy in such mice were suppressed. These mice showed normal phenotypic features and normal responses to Con A. These results suggest that SNMC is effective in some MAIDS mice in preventing the progression of disease. When lymphocytes isolated from the liver, spleen and lymph nodes of diseased mice were cultured in vitro, they showed a spontaneous proliferation. Interestingly, such proliferation was inhibited by addition of liver lymphocytes, but not splenic lymphocytes, obtained from normal or SNMC-treated mice. Since liver lymphocytes contains intermediate CD3 cells with autoreactivity, they may possibly suppress the progression of disease.

Apoptosis in tumors and normal tissues induced by whole body hyperthermia in rats

Apoptosis in tumor and normal tissues was examined in rats treated with whole-body hyperthermia (WBH; 41.5 degrees C for 2 h). WBH alone produced 0.5 day of tumor growth delay (TGD) in a fibrosarcoma and 5.8 days of TGD in the Ward colon carcinoma. This difference in WBH-induced TGD indicates that the fibrosarcoma is relatively resistant to WBH, whereas the Ward colon carcinoma is relatively heat sensitive. A quantitative histological assay for apoptosis demonstrated that the extent of apoptosis in the fibrosarcoma reached a maximum level of 19% 4 h after WBH and returned to the control level by 24 h. In contrast, WBH induced apoptosis with a peak value of 43% at 8 h in the Ward colon carcinoma, and the apoptotic level remained elevated above the control level until 48 h after WBH. Within normal tissues, the spleen and the lymph nodes showed WBH-induced apoptosis; however, the highest level of WBH-induced apoptosis as well as the most prolonged increase in apoptotic levels occurred in the thymus. The WBH-induced apoptosis in the thymus remained elevated above the control level until 48 h after WBH. Within the entire gastrointestinal tract, the small intestine was the most sensitive to WBH. Apoptotic cells were observed in the small bowel mucosa following WBH exposure. We also noted a minor WBH-induced increase in the apoptotic level in the bone marrow. Except for the case of the thymus, increased apoptotic levels in the normal tissues declined after peak levels at 4 h, and apoptosis above control levels was not seen beyond 12 h following WBH. Thus, within the normal tissues, WBH-induced apoptosis declined to basal levels within 12-48 h. These data indicate that both the extent and the kinetics of WBH-induced apoptosis differ between the two tumors and, meaningfully, between tumor and normal tissues. The extent and duration of apoptosis seem to correlate with tumor response to WBH.

Expression of major histocompatibility complex in mouse peritoneal macrophages increasingly depends on plasma corticosterone levels: stimulation by aconitine

Influence of aconite extract and a main component of aconite, aconitine were investigated on the plasma corticosterone level for the expression of major histocompatibility complex class II (Ia antigen) of macrophage. In peritoneal macrophage exposed to corticosterone (2.9-87 microns) in vitro the interferon (IFN)-gamma (0.1 unit/ml)-induced Ia antigen expression was inhibited in a dose-dependent manner. Ia antigen expression in macrophages harvested from the corticosterone (1.25mg/mouse/d, i.m., 4d)-excessive mice and aconitine (3 micrograms/kg, i.p., 7d)-treated mice was significantly stimulated, whereas that of adrenalectomized (7d) mice was inhibited. In macrophage exposed to aconitine up to 46.5 microns in culture Ia antigen expressed was not affected. Administration of aconite extract (3 mg/kg, i.p., 7d) and aconitine (3 micrograms/kg, i.p., 7d) increased plasma corticosterone levels. These result demonstrate that high levels of corticosterone increases the macrophage response to ifn-gamma on Ia antigen expression and that low levels of corticosterone decrease it. Aconite extract and aconitine stimulate the response to IFN-gamma-activated expression of Ia antigen by macrophages which is caused by increasing the plasma corticosterone level.

Urease production correlates with possession of the trh gene in Vibrio parahaemolyticus strains isolated in Thailand

A total of 489 Vibrio parahaemolyticus isolates from patients in Thailand with diarrhea was examined for the presence of thermostable direct hemolysin (TDH) and TDH-related hemolysin genes (tdh and trh, respectively), their serovars, TDH production, and urease activity. Of the strains, 81% were positive only for the tdh gene, 6% for both trh and tdh genes, and 2% for the trh gene only. Thirty-seven (8%) of the 489 isolates were positive for urease production. Of special interest, all urease-positive strains possessed the trh gene, and conversely, urease-negative strains lacked the gene, indicating that urease production by V. parahaemolyticus strains strongly correlates with the possession of the trh gene. Thus, the urease-positive phenotype of V. parahaemolyticus can be considered an indication of virulent (trh-possessing) V. parahaemolyticus strains in clinical diagnosis.

Lethal shock is inducible by lipopolysaccharide but not by superantigen in mice with retrovirus-induced immunodeficiency syndrome

The retrovirus-induced murine AIDS (MAIDS) shares many features with human AIDS. Here, we examined the susceptibility of mice with MAIDS to staphylococcal enterotoxin-triggered shock. Following sensitization with D-galactosamine (D-Gal), mice with MAIDS were resistant to the otherwise lethal effect of superantigen staphylococcal enterotoxin A (SEA). Peak IL-2 levels in these mice after D-Gal/SEA challenge were 10-fold higher than those in uninfected controls, and concurrently, IL-10 levels rose markedly with reduction of circulating IL-1 and IFN-gamma. Treatment with neutralizing anti-IL-10 mAb before D-Gal/SEA challenge led to increased IFN-gamma levels in mice with MAIDS, and resulted in a dose-dependent mortality. In contrast, mice with MAIDS were more susceptible to the toxicity of bacterial endotoxin LPS than were uninfected controls. Administration of 100 micrograms LPS alone induced 50% lethality in mice infected with MAIDS virus 8 wk previously but not in uninfected controls. Administration of 10 micrograms LPS caused acute shock in D-Gal-sensitized mice with MAIDS. Peak TNF-alpha levels in these mice after LPS challenge were increased more than 10-fold, whereas IL-10 levels were one-third of those after SEA challenge. Moreover, serum IFN-gamma was undetectable in uninfected controls and rose to 1063 +/- 483 pg/ml in mice with MAIDS 4 h after LPS challenge. These results suggest that aberrant profiles of cytokine production are crucial in determining fatal outcome in these two types of septic shock in MAIDS.

Two groups of diabetic KK-CAy mice specifically bred for high and low sensitivity to exogenous acetylcholine and beta 1-adrenergic stimulation: interaction of higenamine and aconitine on pulse rate

Diabetic KK-CAy mice were specifically bred for high and low sensitivity to the addition of exogenous acetylcholine (ACh). The sensitivity to ACh was measured by the change in pulse rate 2 min after the administration of ACh (10 mg/kg, s.c.). The two groups of mice, with high and low sensitivity to ACh, were specially selected and mated sequentially until the 12th filial generation. Although higenamine (100 micrograms/kg, i.p.), a beta 1-adrenergic agonist (a compound derived from aconite), had no effect per se, it inhibited aconitine (another compound derived from aconite extract)-induced bradycardia within 30 s of administration in ACh-low sensitive mice but not in ACh-high sensitive mice. The effects of aconitine and higenamine alone did not differ between these two groups of mice. This demonstrates that the high muscarinic and high beta 1-adrenergic sensitive mice may be stratified into two groups based upon an antagonistic interaction between higenamine and aconitine.

Lethal shock is inducible by lipopolysaccharide but not by superantigen in mice with retrovirus-induced immunodeficiency syndrome

The retrovirus-induced murine AIDS (MAIDS) shares many features with human AIDS. Here, we examined the susceptibility of mice with MAIDS to staphylococcal enterotoxin-triggered shock. Following sensitization with D-galactosamine (D-Gal), mice with MAIDS were resistant to the otherwise lethal effect of superantigen staphylococcal enterotoxin A (SEA). Peak IL-2 levels in these mice after D-Gal/SEA challenge were 10-fold higher than those in uninfected controls, and concurrently, IL-10 levels rose markedly with reduction of circulating IL-1 and IFN-gamma. Treatment with neutralizing anti-IL-10 mAb before D-Gal/SEA challenge led to increased IFN-gamma levels in mice with MAIDS, and resulted in a dose-dependent mortality. In contrast, mice with MAIDS were more susceptible to the toxicity of bacterial endotoxin LPS than were uninfected controls. Administration of 100 micrograms LPS alone induced 50% lethality in mice infected with MAIDS virus 8 wk previously but not in uninfected controls. Administration of 10 micrograms LPS caused acute shock in D-Gal-sensitized mice with MAIDS. Peak TNF-alpha levels in these mice after LPS challenge were increased more than 10-fold, whereas IL-10 levels were one-third of those after SEA challenge. Moreover, serum IFN-gamma was undetectable in uninfected controls and rose to 1063 +/- 483 pg/ml in mice with MAIDS 4 h after LPS challenge. These results suggest that aberrant profiles of cytokine production are crucial in determining fatal outcome in these two types of septic shock in MAIDS.

[General pharmacological study of iodixanol, a new non-ionic isotonic contrast medium]

The general pharmacological study of iodixanol, a non-ionic isotonic contrast medium, was conducted. 1) Iodixanol administered intravenously over a dose range of 320 to 3,200 mgI/kg had little or no effect on the general behavior, spontaneous locomotor activity, hexobarbital sleeping time, pain response, electroshock- or pentylenetetrazol-induced convulsion (mouse), EEG or body temperature (rabbit), gastrointestinal propulsion (mouse) or skeletal muscle contraction (rabbit). Iodixanol had no specific interaction with acetylcholine, histamine, serotonin, nicotin, BaCl2 (ileum), methacholine (trachea), isoprenaline (atrium) or oxytocin (pregnant uterus), nor had any effect on spontaneous contractility (atrium and uterus), or transmural electrostimulation-induced contractility (vas deferens) at concentrations of < or = 3.2 x 10(-3) gI/ml in vitro. Iodixanol had no effect on the cardiovascular system of dog, except that it increased femoral blood flow and respiratory rate at doses of > or = 1,000 mgI/kg. Iodixanol at 3,200 mgI/kg i.v. reduced urine output with a decrease in Na+ and Cl- excretion, whereas at 320 mgI/kg i.v., it slightly increased urine output (rat). 2) Injections of iodixanol into the cerebroventricular (0.96, 9.6 mgI/mouse and 3.2, 32 mgI/rat), left ventricular (1,920, 6,400 mgI/dog) or coronary artery (640, 1,920 mgI/dog) had no conspicuous effect on the central nervous system or the cardiovascular system, respectively. There was no marked difference among iodixanol, iohexol and iopamidol in this respect. Vascular pain during injection into the femoral artery (300-320 mgI/guinea pig) appeared to be less intense with iodixanol, compared with the other contrast media iohexol and iopamidol. These results suggest that intravenous injection of iodixanol is relatively free from pharmacological activity, and effects of iodixanol on the central nervous system (intracerebroventricular injection) and cardiovascular system (intra-left ventricular and -coronary injections) are comparable to those of iohexol and iopamidol. Furthermore, intra-femoral injection of iodixanol has less of a tendency to produce vascular pain than those of iohexol and iopamidol.

Impact of MHC class I gene on resistance to murine AIDS

Development of murine AIDS in mice following infection with LP-BM5 murine leukaemia virus (MuLV) is highly strain dependent, with strain differences determined by genes within and outside H-2. Among H-2 genes, the Dd gene is the most closely associated with resistance to LP-BM5 MuLV infection. However, the Dd-mediated resistance is highly influenced by outside H-2 genes, i.e. A lineage strains are more resistant than mice strains of B6/B10 lineage. In this study, the mice having BALB background were analysed and, similarly to A lineage mice, only Dd gene products were found to be required to provide resistance to LP-BM5 MuLV infection. Furthermore, BALB/c Kh mice bearing both Dd and Ld genes clearly showed obviously higher resistance than BALB/c-H-2dm2 mice solely having the Dd gene. In addition, in the long-term observation of the effect of the Dd gene on B6/B10 background mice, D8 mice having the Dd gene as a transgene and expressing a high level Dd gene product showed higher resistance than naturally recombinant B10.A(18R) mice. These results suggest that the MAIDS resistance associated with the D end loci is dependent on the level of expression of an MHC class I gene.

Effects of suprachiasmatic lesions on circadian rhythms of blood pressure, heart rate and locomotor activity in the rat

To determine whether the circadian rhythms in blood pressure (BP), heart rate (HR) and locomotor activity are controlled by an internal biological clock located in the suprachiasmatic nucleus (SCN), we continuously measured these parameters in SCN-lesioned rats using a newly developed implantable radiotelemetry device and a computerized data collecting system. Although SCN-lesioned rats showed a weak but significant 24-h periodicity in BP and HR under light-dark (LD) cycles, BP, HR and locomotor activity became completely aperiodic under constant dark (DD) conditions. The amount of locomotor activity was significantly reduced in SCN-lesioned rats compared to that in intact rats. BP tended to be higher in SCN-lesioned rats, but the differences were significant only in the comparison of systolic blood pressure (SBP) under LD and DD (p < 0.05) and of mean blood pressure (MBP) under LD (p < 0.05). HR in SCN-lesioned rats was significantly lower under LD (p < 0.05), but not under DD. The standard deviation and the variation coefficient of MBP, as indices of short-term variability of this parameter, were significantly larger in SCN-lesioned rats than in intact rats, while those of HR and locomotor activity did not differ significantly between SCN-lesioned and intact rats. These results indicate that the SCN is important not only for generating circadian rhythms of BP, HR and locomotor activity, but also for buffering the short-term variability of BP in rats.

Rapid development of murine AIDS is dependent of signals provided by CD54 and CD11a

Murine AIDS (MAIDS) is induced by infection with the replication-defective virus (BM5def) component in the LP-BM5 murine leukemia virus (MuLV) mixture. The disease is characterized by polyclonally activated CD4+ T cells and B cells. It is known that BM5def is expressed at highest levels in B lymphocytes and that B cells serve as viral antigen-presenting cells. Full and sustained activation of CD4+ T cells against a conventional Ag usually requires both TCR and costimulating signals. Among various molecules known to provide costimulatory function, the expression of CD54 (ICAM-1) and CD11a/CD18 (LFA-1) on MAIDS B cells was increased, whereas that of CD2, heat-stable Ag (CD24), CD80 (B7-1), and CD86 (B7-2) was unchanged from normal. C57BL/6 mice depleted of both CD54 and CD11a expression as a result of chronic administration of mAb had developed no MAIDS at 4 wk and 8 wk after LP-BM5 MuLV infection. In addition, the proliferative response of B cells to mitogen was well conserved, whereas MAIDS-associated increases in serum Ig levels were inhibited. Replication of BM5def was suppressed markedly in infected mice treated with the CD54 and CD11a mAbs. These results suggest that the CD54/CD11a signal transduction pathway is a critical determinant of MAIDS development, and the lack of an immune response against viral Ag is enough to suppress BM5def replication and to prevent MAIDS.

Rapid development of murine AIDS is dependent of signals provided by CD54 and CD11a

Murine AIDS (MAIDS) is induced by infection with the replication-defective virus (BM5def) component in the LP-BM5 murine leukemia virus (MuLV) mixture. The disease is characterized by polyclonally activated CD4+ T cells and B cells. It is known that BM5def is expressed at highest levels in B lymphocytes and that B cells serve as viral antigen-presenting cells. Full and sustained activation of CD4+ T cells against a conventional Ag usually requires both TCR and costimulating signals. Among various molecules known to provide costimulatory function, the expression of CD54 (ICAM-1) and CD11a/CD18 (LFA-1) on MAIDS B cells was increased, whereas that of CD2, heat-stable Ag (CD24), CD80 (B7-1), and CD86 (B7-2) was unchanged from normal. C57BL/6 mice depleted of both CD54 and CD11a expression as a result of chronic administration of mAb had developed no MAIDS at 4 wk and 8 wk after LP-BM5 MuLV infection. In addition, the proliferative response of B cells to mitogen was well conserved, whereas MAIDS-associated increases in serum Ig levels were inhibited. Replication of BM5def was suppressed markedly in infected mice treated with the CD54 and CD11a mAbs. These results suggest that the CD54/CD11a signal transduction pathway is a critical determinant of MAIDS development, and the lack of an immune response against viral Ag is enough to suppress BM5def replication and to prevent MAIDS.

[Flow cytometric measurement of p53 protein and DNA content in colorectal carcinomas with liver metastasis]

To investigate the possible relation between p53 protein, DNA content and liver metastasis of colorectal cancer, overexpression of p53 and DNA content were measured by flowcytometer in 113 primary lesions, which included 34 cases with simultaneous liver metastasis and 79 cases with curative resection, and 25 metastatic lesions of the liver. Overexpression of p53 and DNA aneuploidy were found in 44 (38.9%) and 77 (68.1%) of 113 primary lesions, respectively. However, p53 protein and DNA aneuploidy were unrelated to the clinicopathological findings, such as liver metastasis, venous invasion and lymph node metastasis. Comparing the overexpression of p53 protein between primary and metastatic lesions, p53 protein was recognized in 18 (72.0%) of 25 metastatic lesions of the liver. Incidence of p53 protein was significantly higher in metastatic lesions of the liver than in primary lesions (p < 0.01). On the other hand, p53 protein was found in 27 (60.0%) of 45 diploid lesions and in 35 (37.6%) of 93 aneuploid lesions. There was a significant difference in p53 protein between diploid and aneuploid tumors (p < 0.05). These results suggest that p53 protein may not correlate with the occurrence of liver metastasis and might be produced in the metastatic lesion of the liver after metastasis.

Hot water extracts of Chlorella vulgaris reduce opportunistic infection with Listeria monocytogenes in C57BL/6 mice infected with LP-BM5 murine leukemia viruses

The bacterial elimination after infection with Listeria monocytogenes was impaired in mice with murine acquired immunodeficiency syndrome (MAIDS) by infection with LP-BM5 murine leukemia virus. Oral administration of hot water extracts of Chlorella vulgaris (CVE) restored the capacity of MAIDS mice to eliminate L. monocytogenes in association with improvement of the deteriorated immune response to L. monocytogenes. DTH response to Listeria in CVE-treated MAIDS mice was significantly higher than that of MAIDS mice after Listeria infection in association with increases in number of CD4+CD8- and CD4-CD8+ alpha beta T-cells in the infected sites. CVE might be effective in the treatment of opportunistic infection in retrovirus-induced immunodeficient patients.

Correlation between the adsorption tendency of cationic disinfectant onto a synthetic multibilayer and its minimum inhibitory concentration

Minimum inhibitory concentration (the lowest concentration able to inhibit growth of microorganisms after 48 h contract) could be useful as a measure of bactericidal activity of cationic disinfectants. The relation between the minimum inhibitory concentration (microgram/ml) of cationic disinfectants against gram-negative microorganisms and the adsorption tendency of these compounds onto a lipid bilayer was therefore studied using a quartz crystal microbalance (QCM) coated with synthetic multibilayer film. The adsorbed amounts of these compounds were obtained from the frequency decrease of the QCM in aqueous solutions. The calculated partition coefficients showed a good correlation with the minimum inhibitory concentrations of cationic disinfectants against E. coli and K. pneumoniae, supporting the validity of this method for predicting minimum inhibitory concentration. The results suggest that effective antibacterial agents are only slightly absorbed, and may mostly penetrate through the lipid bilayer.

Mutations in rpoB gene of rifampicin resistant clinical isolates of Mycobacterium tuberculosis in Japan

In Mycobacterium tuberculosis, involvement of alterations of the RNA polymerase beta subunit in resistance to rifampicin has been described by Telenti et al. To determine if the same correlation could be observed between the mutation of the rpoB gene and clinically isolated M. tuberculosis of the rifampicin-resistant phenotype in Japan, 47 strains of M. tuberculosis of the rifampicin-resistant phenotype, 17 of the rifampicin-susceptible phenotype, and 4 type strains were examined. A 411-base pair (bp) rpoB fragment was amplified by the polymerase chain reaction and subjected to solid phase direct sequencing. By comparing the nucleotides, mutation involving 8 conserved amino acids were identified in 44 of the 47 (93.6%) rifampicin-resistant isolates, but in none of the 17 sensitive isolates and 4 type strains. All mutations found were clustered within a region of 23 amino acids. Thus, similar to the results reported by Telenti et al., substitution of a limited number of highly conserved amino acids encoded by the rpoB gene appears to be the molecular mechanism responsible for resistance to rifampicin in Japanese clinical isolates of M. tuberculosis. Our results suggest that direct DNA sequencing of the rpoB gene may be a reliable method for identifying rifampicin-resistant M. tuberculosis strains among Japanese clinical isolates.

Prophylactic portal infusion chemotherapy as adjuvant therapy for the prevention of metachronous liver metastasis in colorectal cancer

The DNA ploidy and DNA indices (DI) of 414 patients with colorectal cancer were analyzed, and the incidence of patients with metachronous liver metastasis was found to be significantly higher in those with aneuploid tumors and a DI above 1.5 than in those with aneuploid tumors and a DI below 1.4, or in those with diploid tumors and a DI equal to 1.0. Next, to confirm the effectiveness of administering prophylactic portal infusion chemotherapy (PPIC) as adjuvant therapy for the prevention of metachronous liver metastasis in colorectal cancer, a randomized controlled trial of PPIC was performed on 110 consecutive patients with primary colorectal cancer who had undergone curative resection. Although the incidence of patients with metachronous liver metastasis in the two study groups was not significantly different at 3.3% in the PPIC group and 10.3% in the control group, the incidence in the patients with aneuploidy and a DI above 1.5 was significantly lower in the PPIC group than in the control group. These findings suggest that colorectal cancer with aneuploidy and a DI above 1.5 may have a strong tendency to metastasize to the liver, and that prophylactic portal infusion chemotherapy may be effective for preventing metachronous liver metastasis in such patients.

Synthesis of carbocyclic nucleoside precursors from bicyclo[2.2.1]hept-5-enes using a novel reductive C-C bond cleavage reaction

Dimethyl c-4-aminomethylcyclo-pent-2-en-r-1-ylmalonate, an precursor of carbocyclic homo-nucleosides, has been synthesized from the bicyclo-[2.2.1]helpt-5-ene derivative prepared by the Diels-Alder reaction of cyclopentadiene with dimethyl trifluoroacetylaminomethylenemalonate, which is a new dienophile. The synthetic method involves a novel C-C bond cleavage reaction by sodium borohydride.

An IFN-gamma-dependent pathway plays a critical role in the pathogenesis of murine immunodeficiency syndrome induced by LP-BM5 murine leukemia virus

The murine acquired immunodeficiency syndrome (MAIDS) caused by a defective murine leukemia virus produces severe immunodeficiency with abnormal lymphoproliferation and hypergammaglobulinemia. The presence of both CD4+ T cells and B cells is critical for the development of this disease. Remarkably elevated mRNA expression for IFN-gamma and IL-10 was observed in spleen cells of C57BL/6 mice starting from the early phase of viral infection. IFN-gamma production was induced by spleen cells from virus-infected mice upon stimulation with concanavalin A or lipopolysaccharide in both the early and late phases of MAIDS progression. When mice that had been passively administered anti-IFN-gamma mAb were infected with the virus, the development and progression of lymphadenopathy, immunodeficiency and elevated levels of serum IgG2a associated with MAIDS were delayed. Treatment with anti-IL-4 or anti-IL-10 mAb in place of anti-IFN-gamma mAb did not induce the delayed progression of MAIDS. These data support the concept that IFN-gamma-dependent pathway may be involved in the development of MAIDS.

Radiation-induced malignant fibrous histiocytoma of the transverse colon: case report and review of the literature

We report the first case, to our knowledge, of a malignant fibrous histiocytoma (MFH) of the transverse colon that seems to have been induced by radiation and we review the 12 other cases of colorectal MFH in the literature. The frequency of recurrence after radical surgery was 33% (4/12), excluding a patient with synchronous liver metastases, during the follow-up periods reported in the literature. The presence of ulceration of the tumor was a factor indicating poor prognosis (P < 0.001). Our patient had local recurrence and peritoneal metastases within only 3 months after curative resection and died 4 months after the initial operation. This case may suggest the necessity of adjuvant chemotherapy or radiotherapy in such patients, although the effectiveness of these methods has not been confirmed.

Correlation between zeta-potential of a cell in a new cationic disinfectant solution and minimum inhibitory concentration of the disinfectant

In the previous paper, we described the synthesis of new quaternary ammonium slats with antimicrobial activity: N-alkyl-N-2-hydroxyethyl-N,N-dimethylammonium butyl phosphate (4) and N-alkyl-N-(2-hydroxy-3-phenoxy)-propyl-N,N-dimethylammonium butyl phosphate (5). In this study, we examined the relationship between the MIC (minimum inhibitory concentration) of these new cationic disinfectants, 4 (six compounds) and 5 (three compounds), and the xi-potential against Escherichia coli in solutions of these compounds. The MIC values of these disinfectants against E. coli were highly correlated with the concentration that induced electric charge inversion (xi-potential=0) of E. coli from negative to positive.

Clonal expansion but lack of subsequent clonal deletion of bacterial superantigen-reactive T cells in murine retroviral infection

Several studies have suggested that activation-induced apoptosis of Ag-specific CD4+ T cells leads to depletion of this subset during HIV infection. The bacterial superantigen, staphylococcal enterotoxin A (SEA), is known to induce activation-induced apoptosis in the TCR V beta-bearing CD4+ T cells in the periphery after clonal expansion of these cells. The murine retroviral model of AIDS (MAIDS), which is induced by LP-BM5 murine leukemia virus, shares many common features with HIV infection in humans, except that CD4+ T cells increase progressively in susceptible strains. In this study, we challenged SEA to MAIDS mice and examined whether this retrovirus affects the fate of the SEA-reactive CD4+ T cells in vivo. At 4 wk post-infection with LP-BM5 murine leukemia virus, clonal expression and subsequent deletion of SEA-reactive CD4+V beta 3+ T cells occurred normally after SEA administration, whereas in vitro proliferative responses were severely impaired. At 8 wk postinfection, the in vivo expansion of CD4+V beta 3+ T cells was evident, but not followed by clonal deletion, as late as 14 days after SEA administration. This expanding subset in the infected mice expressed the Fas Ag in the same amount as the same subset in uninfected controls. These findings suggest that activation-induced apoptosis of superantigen-reactive CD4+ T cells is interfered with in vivo during the course of MAIDS, which is not attributable to underexpression of the Fas Ag by the CD4+ T cells.