Effects of exogenous interferon on L cells persistently infected with Sendai virus

A carrier culture of L cells persistently infected with Sendai virus (steady state) designated as L-Sendaits cells was established with a temperature-sensitive strain of the virus. When interferon was added to culture fluids from the start of the cultures at permissive (35 degrees C) or non-permissive temperature (38 degrees C), cell-associated infectivity was unaffected at 35 degrees C, while it was unexpectedly enhanced at 38 degrees C, although the cell-associated infectivity was titrated after further incubation at 32 degrees C for 2 days. The titer of cell-associated infectivity was increased by subculturing in the continuous presence of interferon at 38 degrees C. The effect of interferon on the paradoxical enhancement of cell-associated infectivity was shown to be dose dependent. When L-Sendaits cells were successively subcultured 6 times at 38 degrees C in the continuous presence or absence of interferon, more than 95 per cent of the cells contained a detectable amount of nucleocapsid (NP) antigen in the presence of interferon, whereas the antigen could be detected in only 30-40 per cent of the cells subcultured in the absence of interferon. Only when the cells subcultured at 38 degrees C in the presence of interferon were transferred to permissive temperature, could the distinct hemadsorbing and cell-associated hemagglutinating activities and the release of virus particles, as measured by hemagglutinating activity in the culture fluids, be detected. Cells subcultured in the presence of interferon accumulated more virus polypeptides than in the absence of interferon. Accumulation of virus specific RNA in the cells subcultured in the presence of interferon was about twice as much as that in the absence of interferon. Larger sized RNA (probably 50S) was the major species and two smaller RNAs could be detected in both the treated and untreated cells. When L-Sendaits cells were cultured at 38 degrees C in the presence of interferon, their multiplication was clearly inhibited. However, the cells which were subcultured twice at 38 degrees C in the continuous presence of interferon acquired resistance to the anti-cell proliferative action of interferon. Interestingly, the conversion of the sensitive state to resistant state of the cells was reversible.

Involvement of DNA polymerase alpha in host cell reactivation of UV-irradiated herpes simplex virus

Aphidicolin is a potent inhibitor of both host cell DNA polymerase alpha and herpes simplex virus (HSV)-induced DNA polymerase but has no effect on DNA polymerases beta and gamma of host cells. By using an aphidicolin-resistant mutant (Aphr) of HSV, a possible involvement of DNA polymerase alpha in host cell reactivation of UV-damaged HSV was studied. Plaque formation by UV-irradiated Aphr was markedly inhibited by 1 microgram of aphidicolin per ml, which did not affect the plating efficiency of nonirradiated Aphr. Aphidicolin added before 12 h postinfection inhibited plaque formation by irradiated Aphr, which became aphidicolin insensitive after 36 h postinfection. The results strongly suggest that host cell DNA polymerase alpha is involved in the repair of UV-irradiated HSV DNA.

Identification of DNA polymerase(s) involved in the repair of viral and cellular DNA in herpes simplex virus type 2-infected cells

When human embryonic fibroblasts (HEF) were infected with herpes simplex virus type 2 (HSV-2), replicative viral DNA synthesis and some repair synthesis of cellular DNA were induced at the early stage of infection, but almost all DNA synthesis at the late stage of infection was derived from repair synthesis of cellular and viral DNA (Y. Nishiyama and F. Rapp, Virology 110, 466-475, 1981). In this study, we have assessed the effects of DNA polymerase inhibitors on repair DNA synthesis HSV-2-infected HEF. Both viral and cellular DNA syntheses during the late stage of infection were extremely resistant to aphidicolin and phosphonoacetic acid but partially sensitive to high concentrations of 1-beta-D-arabinofuranosylcytosine, while replicative viral DNA synthesis during the early stage of infection was very sensitive to all of those inhibitors. The results suggest that neither HSV-induced DNA polymerase nor cellular DNA polymerase alpha was involved in the repair synthesis of viral and cellular DNA but that cellular DNA polymerase beta was.

[Placental tissue concentration of pregnancy-associated proteins in early and term pregnancies]

We examined the localization of five pregnancy-associated proteins such as pregnancy specific beta 1-glycoprotein (SP1), human chorionic gonadotropin (HCG), human placental lactogen (HPL), alpha 2-PA-glycoprotein (SP3) and pregnancy-associated plasma protein-A (PAPP-A) in the placentae of early and term pregnancies by means of the PAP method in immunohistochemical technology. It was found that the degree of staining of these proteins did not reflect their concentration in serum at each gestational age. Therefore, the concentrations of these proteins in the solution extracted from the placenta were measured. 1) Placental tissues were fixed with a 10% neutral formaldehyde solution and these were embedded into paraffin blocks. These specimens were used for the PAP method. The localizations of five pregnancy-associated proteins from 10 placentae at the gestational age of 7 to 10 weeks were compared with those at the gestation age of 38 to 41 weeks from 7 patients. The staining degree of SP1 in free villi was pale in both early and term pregnancies. HCG was stained deeply in early pregnancy but pale at term pregnancy. HPL was stained deeply at both gestational ages. Horseradish peroxidase reaction products from SP1, HCG and HPL were located chiefly in the syncytiotrophoblast. SP3 was not stained on the placental tissue. PAPP-A was stained to a greater extent in the cytotrophoblast in early pregnancy but pale in the syncytiotrophoblast at term pregnancy. 2) The concentrations of SP1, HCG, HPL, SP3 and PAPP-A were measured in the placental tissues in both early and term pregnancies. Placental tissues were obtained from 24 normal pregnancy patients aborted artificially at 8 to 11 weeks gestation and from 28 patients terminated by normal deliveries at 38 to 40 weeks gestation. The tissue was homogenated with 3 volumes of 1/2 PBS (0.005M phosphate-buffered 0.07M sodium chloride, pH 7.4). The supernatant was removed after centrifugation and stored at -20 degrees C until assayed. The concentration of SP1 was measured by single radial immunodiffusion. That of HCG was assayed by a directed Latex agglutination test (Gestate Slide Eiken). The concentrations of HPL, SP3 and PAPP-A were quantified by rocket immunoelectrophoresis. No significant difference in SP1 levels was shown between early and term pregnancies, and the SP1 level was 4.3 +/- 1.3 (mean +/- 1 S.D.) mg/dl at term pregnancy. The HCG level was 1,100 +/- 300 IU/ml in early pregnancy and at least 20-fold higher than that at term pregnancy.(ABSTRACT TRUNCATED AT 400 WORDS)

Effect of high salt treatment on influenza B viral protein synthesis in MDCK cells

Based on the information that high salt inhibits the initiation of cellular mRNA translation which depends on the function of the 5'-terminal structure of mRNA, we compared the effect of high salt on translation of host cellular mRNAs and influenza viral mRNAs, both of which are of 5'-terminal structure. Brief exposure of influenza B virus-infected MDCK cells to high salt medium resulted in a dose-dependent inhibition of viral polypeptide synthesis as well as of cellular polypeptide synthesis, but it had less effect on synthesis of viral polypeptides, particularly nonstructural protein (NS). Under these conditions the Na+ content of the infected cells was significantly increased. A similar salt effect on in vitro translation of viral and cellular mRNAs extracted from infected cells was also observed. There was no significant difference in sensitivity to hypertonic block of in vivo translation of influenza viral mRNAs and vesicular stomatitis virus mRNAs, the latter of which possess a virus-directed structure at the 5'-terminus.

[Epidemiologic studies on multiple cancers in Japan]

During a 21-year period, 3040 patients with malignant tumors were treated at the Division of Surgery, Fukuyama National Hospital. Of these 86 (2.8%) were diagnosed as having double cancers. The simultaneous double cancer rate was 27.3%. Statistical study showed that the etiology had a relation to family history and previous therapy, but not to immunology. The prognosis was good and diagnosis by RI was non-specific.

Mechanism of uncoating of influenza B virus in MDCK cells: action of chloroquine

Exposure of influenza B virus-infected MDCK cells to chloroquine at the time of infection resulted in significant inhibition of infection. The appearance of input virus in the intracellular vesicles was not affected in the presence of the drug, but primary transcription of the virus genome did not occur. Chloroquine caused a rapid rise in the pH inside the lysosomes of MDCK cells, to 6.5 from the physiological pH 5.6. In contrast, exposure of infected cells incubated in acidic medium (pH 6.0) to chloroquine did not cause an increase in lysosomal pH and this low pH treatment during the chloroquine-sensitive phase was followed by virus production. Influenza B virus induced haemolysis of chick erythrocytes at low pH values (5.0 to 5.9) which was associated with cell-cell membrane fusion. It is likely that chloroquine prevents the uncoating of influenza B virus by increasing the lysosomal pH above the critical value required for inducing fusion between the virus envelope and the lysosomal membrane.

Heat(40 degrees C)-induced polypeptides in human embryonic fibroblasts

The synthesis of 3 polypeptides with molecular weights of 103-, 80- and 78-kdalton (K) was dramatically accelerated when the cultures of human embryonic fibroblasts were transferred from 37 to 40 degrees C. The induction of these polypeptides was not observed if actinomycin D was added to the cultures at the beginning of the rising of the temperature, indicating that this response may be mediated by increased transcription of their messenger RNA.

Role of the nuclear matrix in the growth of herpes simplex virus type 2

Nuclear matrix was prepared from Vero cells infected with herpes simplex virus type 2. In the early stage of infection, both 155K and 110K viral proteins were associated with the nuclear matrix, while in the late stage, 155K protein, presumably a viral capsid protein, was predominantly associated with the matrix. Electron microscopic study showed that empty capsids were bound to the filamentous networks of the nuclear matrix of the late stage. Neither viral DNA nor viral DNA polymerase activity was associated with the nuclear matrix. These results may indicate that the nuclear matrix plays some role in the growth of herpes simplex virus, especially during the morphogenesis.

Characterization of human cytomegalovirus-induced DNA polymerase and the associated 3'-to-5', exonuclease

A DNA polymerase activity induced by human cytomegalovirus (HCMV) was separated from host cell DNA polymerase and purified by phosphocellulose and DNA-cellulose column chromatography. The DNA polymerase activity was strongly inhibited by phosphonoacetic acid, aphidicolin, araATP, and N-ethylmaleimide, but it was resistant to 2',3'-dideoxyTTP. The sensitivity of HCMV-induced DNA polymerase to these reagents resembles that of host cell DNA polymerase alpha. However, HCMV-induced DNA polymerase activity was stimulated several fold by 100 mM ammonium sulfate, by which DNA polymerase alpha activity was strongly inhibited. Furthermore, it was found that a 3'-to-5' exonuclease activity was tightly associated with the HCMV-induced DNA polymerase. The exonuclease was also stimulated by ammonium sulfate, was inhibited by phosphoacetic acid, and it preferred single-stranded DNA as a substrate. The results suggest that the 3'-to-5' exonuclease may play a role in proofreading in the polymerization process as an integral part of the HCMV-induced DNA polymerase.

[Immunohistochemical study of SP1, HPL and HCG in chorionic tissue with early spontaneous and induced abortions]

Using an indirect enzyme-labeled antibody method, localization of SP1, HPL and HCG in spontaneous abortions (29 cases) was compared with those in induced abortions (39 cases). At the same time, histological changes were examined in the same specimens. 1) Histologically, the fibrinoid degeneration in cytotrophoblastic mass was more often found in spontaneous abortions than in induced abortions. Stromal fibrosis frequently existed in spontaneous abortions (6-10 weeks: 53%, 11-16 weeks: 93%). Stromal edema was rare in induced abortions, but was detected in spontaneous abortions (6-10 weeks: 13%, 11-16 weeks: 50%). These findings were increased with gestational age. 2) Horseradish peroxidase (HRP) reaction products from SP1, HPL and HCG located mainly in the syncytiotrophoblast. The intensity of HRP reaction was not always uniform in each villus. 8% in induced abortions and 59% in spontaneous abortions showed reaction with anti-HCG in some stromas in syncytiotrophoblast. Most of them also showed stromal fibrosis. In spontaneous abortions, the intensity of HRP reaction on HPL was relatively increased in comparison with that on HCG or SP1. In some severe degenerated specimens, SP1 and HPL were found in syncytiotrophoblast, but HCG seemed to be located on the outer part of the stroma adjacent to syncytiotrophoblast.

Effects of DNA polymerase inhibitors on replicative and repair DNA synthesis in ultraviolet-irradiated HeLa cells

Aphidicolin specifically inhibits eukaryotic DNA polymerase alpha, while 2',3'-dideoxythymidine 5'-triphosphate (d2TTP) inhibits DNA polymerase beta and gamma but not alpha. 1-beta-D-Arabinofuranosylcytosine 5'-triphosphate (araCTP) inhibits both DNA polymerase alpha and beta although to a different extent. Here we measured the effects of these inhibitors on repair DNA synthesis of U.V.-irradiated HeLa cells by two different methods. Firstly, aphidicolin, 1-beta-D-arabinofuranosylcytosine (araC, a precursor of araCTP) and 2',3'-dideoxythimidine (d2Thd, a precursor of d2TTP) were added directly to the culture medium. In this case, aphidicolin and araC strongly inhibited replicative DNA synthesis of HeLa cells, and they also inhibited repair synthesis after U.V.-irradiation but to a much lesser extent. In contrast, high concentrations of d2Thd inhibited repair DNA synthesis to a higher extent than replicative DNA synthesis. Secondly, the active form of inhibitor, d2TTP, was microinjection directly into cytoplasm or nuclei or U.V.-irradiated HeLa cells. Microinjection of d2TTP effectively inhibited repair synthesis. The microinjection of d2TTP, into either cytoplasm or nucleus, strongly inhibited replicative synthesis. These results might indicate that multiple DNA polymerases are involved in repair synthesis as well as in replicative synthesis.

Postmortem formation of carbon monoxide

Since carbon monoxide (CO) production after death was suggested in a drowned body, CO and carboxyhemoglobin (HbCO) levels in blood and body cavity fluids of cadavers which were not exposed to fire and CO hve been analyzed. CO released from the tissues was determined by gas chromatography and gas chromatography-mass spectrometry, and the total concentration of hemoglobin (Hb) was measured as cyanmethemoglobin (CNmHb). The HbCO level was calculated by the ratio of CO content and CO-binding capacity. CO levels (ml/100 g at STP) of the seven cases in which blood and body cavity fluids could be collected ranged from 0.13 to 0.87 in blood and 0.02 to 0.80 in body cavity fluids. HbCO levels in blood and body cavity fluids were from 0.3 to 6.0% and from 2.3 to 44.1%, respectively. In a typical case showing postmortem formation of CO, the CO levels in body cavity fluids were higher than that in blood. It is suggested that CO in a putrefied body is due to CO in blood prior to death and the CO formed by the decomposition of Hb, myoglobin and other substances during putrefaction. The significance of HbCO levels in body cavity fluids of cases with marked postmortem decomposition seems difficult to interpret without the value of HbCO in blood.

Role of viral glycoproteins in haemolysis by influenza B virus

Influenza B virus exhibited haemolytic activity at low pH, but the pH profile for its activity varied from strain to strain. The results of selective heat-inactivation of the enzyme activity of neuraminidase (NA) or elimination from virions of the enzyme-active portion of the NA molecule by trypsin digestion, suggest that proteolytically cleaved haemagglutinin, but not enzyme activity of NA, is essential for haemolysis by influenza B virus.

[Studies on pregnancy specific beta 1-glycoprotein (SP1) by enzymeimmunoassay (author's transl)]

We developed a highly sensitive EIA for determination of SP1. The detection limit was 5ng/ml, and the correlation of EIA and RIA was extremely good (SAWAKI et al., 1980). Using this method, we found that SP1 was detected even in the serum at 12 days of ovulation. The concentration of SP1 in cord blood was on average 127ng/ml (24-540ng/ml). SP1 in newborn serum was 126ng/ml (22-355ng/ml) in 1st, and almost undetected in 4th day. SP1 in urine was 9.7ng/ml in the 5th week of pregnancy, 1,210ng/ml at peak in the 32th week, and in after delivery was 439ng/ml in 1st day and afterwards descended to 6ng/ml in 8th day. In 2 infertile women SP1 was detected in the sera of 14 days after ovulation. This suggests that SP1 measurment might be useful in the diagnosis of occult pregnancy. Three patients with throphoblastic disease were found to have regression curves for both HCG and SP1. The sera of 39 patients with uterine cervical carcinoma were examined to determine the occurrence of elevated SP1 levels. Ten of 27 patients before treatment had increased SP1 levels while only one of 12 patients had an increased SP1 level after treatment.

Immunological responses of hamsters in the acquired immune state to Mycoplasma pneumoniae infection

Protective effects of vaccination of hamsters against Mycoplasma pneumoniae infection, evaluated according to the recovery of mycoplasmas and histopathological changes in the respiratory tract after challenge infection, persisted for at least 6 months after the final vaccination. Serum antibody levels reached a maximum in the second week after the last vaccination and decreased markedly between the first and the third months, but increased again in sera obtained from animals given booster injections. Metabolism-inhibiting antibodies were detected in bronchial washings of animals showing high resistance obtained by vaccinal or passive immunization. Antiserum transfer was also effective for protection but cell-mediated immune responses were not demonstrated in any animals up to 6 months after the vaccination. Even after 10 months, suppression of both mycoplasmal proliferation and lung lesions was apparent, and a single dose of the vaccine induced a significant booster effect. These findings suggest that (1) humoral immunity is more important than cell-mediated immunity in resistance of hamsters to M. pneumoniae pneumonia, and (2) the antibody secreted in the respiratory tract may be involved in the local defense mechanisms.

Plaque formation by human-origin parainfluenza type 2 virus in established cell lines

Two strains of parainfluenza type 2 virus formed well-defined plaques in cultures of Vero cells, an established line of African green monkey kidney cells. In the absence of trypsin, satisfactory plaques were formed by the Toshiba strain of virus. When trypsin was added in the overlay medium of Vero cell monolayers, another strain (62-M786) of virus produced plaques. The Toshiba strain was also able to make plaques in HeLa, BHK, and LLC-MK2 (an established line of monkey kidney) cells without trypsin, but not in mouse L cells. The sensitivity of plaque assay was about equal to that of the hemadsorption method.

Immunological studies on the antitumor effect of sporamycin

The role of immunological effects in the antitumor activity of sporamycin activity of sporamycin was studied mainly using the mouse syngeneic tumor, Meth-A. Sporamycin inhibited the growth of the Meth-A tumor and Balb/c mice, and 12 out of 19 mice were cured. The 12 survivors did not show any growth of reinoculated Meth-A cells. Enzymes-histochemical observations revealed marked activities of both acid phosphatase and alpha-naphthyl acetate esterase in lymphoid cells and macrophages which heavily infiltrated the tumor tissue. Pretreatment of mice with sporamycin produced a remarkable inhibition of tumor growth. A marked neutralization activity against tumor cells was observed by Winn's method using spleen cell of tumor-bearing mice which had been pre- or post-treated with sporamycin. However, this neutralization activity was depressed by anti-Thy 1.2 serum plus complement. The response of spleen cells to concanavalin A was increased by treatment with sporamycin in mice. All of these findings suggest that sporamycin may, at least partially, act by modulating the cellular immune response.

Tallysomycin, a new antitumor antibiotic complex related to bleomycin. IV. New biosynthetic derivatives of tallysomycin

A series of new biosynthetic derivatives of tallysomycins A and B were obtained by precursor amine-feeding fermentation. Certain diamines were incorporated into tallysomycins as the terminal amine moiety affording two classes of biosynthetic derivatives, with or without the Beta-lysine moiety in the subterminal position. Among 21 derivatives prepared, tallysomycin S10b was selected for further studies in view of its favorable therapeutic indices.

Tallysomycin, a new antitumor antibiotic complex related to bleomycin. V. Production, characterization and antitumor activity of tallysomycin S10b, a new biosynthetic tallysomycin derivative

Tallysomycin S10b is a biosynthetic derivative of tallysomycin B obtained by precursor amine-feeding fermentation. Tallysomycin S10b contains 1,4-diaminobutane as the terminal amine moiety in place of spermidine of tallysomycin B, and its assigned structure was verified by carbon-13 NMR spectrum. The antitumor activity of tallysomycin S10b was comparable to that of tallysomycin A against sarcoma 180 but less active than the latter against leukemia P388. Tallysomycin S10b was less toxic than tallysomycin A in terms of acute and subacute LD50 values. The nephrotoxic potential of tallysomycin S10b in rats was less than that of tallysomycin A.

[Study on the properties of pregnancy-specific beta 1-glycoprotein (SP1) in urines of pregnant women (author's transl)]

The properties of pregnancy-specific beta 1-glycoprotein (SP1) were examined in urines of pregnant women. Two cross-reactive substances with rabbit antisera to SP1 were observed in the urines of pregnant woman. By agar gel immunodiffusion method two lines were formed and by single radial immunodiffusion (SRID) double rings were detected in concentrated pregnancy urines. The immunoprecipitate of the inner ring in SRID was distinct, while that of the outer ring was rather indistinct, compared with the former. The substance to make inner ring (tentatively called SP1-A) was found to be the same as SP1 in pregnant serum. The SP1-like substance to make outer ring (tentatively called SP1-B) appeared to be specific to pregnant urine. Although the precipitation lines of urinary SP1 were slightly different from that of serum SP1, both Sp1-A and SP1-B were migrated towards the beta 1-globulin region in immunoelectrophoresis. The molecular weights were estimated by gel filtration method and calculated to be 110,000 for SP1-A and 75,000 for SP1-B, respectively.

Enhanced capacity of DNA repair in human cytomegalovirus-infected cells

Plaque formation in Vero cells by UV-irradiated herpes simplex virus was enhanced by infection with human cytomegalovirus (HCMV), UV irradiation, or treatment with methylmethanesulfonate. Preinfection of Vero cells with HCMV enhanced reactivation of UV-irradiated herpes simplex virus more significantly than did treatment with UV or methylmethanesulfonate alone. A similar enhancement by HCMV was observed in human embryonic fibroblasts, but not in xeroderma pigmentosum (XP12BE) cells. It was also found that HCMV infection enhanced hydroxyurea-resistant DNA synthesis induced by UV light or methylmethanesulfonate. Alkaline sucrose gradient sedimentation analysis revealed an enhanced rate of synthesis of all size classes of DNA in UV-irradiated HCMV-infected Vero cells. However, HCMV infection did not induce repairable lesions in cellular DNA and did not significantly inhibit host cell DNA synthesis, unlike UV or methylmethanesulfonate. These results indicate that HCMV enhanced DNA repair capacity in the host cells without producing detectable lesions in cellular DNA and without inhibiting DNA synthesis. This repair appeared to be error proof for UV-damaged herpes simplex virus DNA when tested with herpes simplex virus thymidine kinase-negative mutants.

Latency in vitro using irradiated herpes simplex virus

Human embryonic fibroblasts infected with u.v.-irradiated herpes simplex virus type 2 (HSV-2, strain 186) and maintained at 40.5 degrees C did not yield detectable virus. Virus synthesis was induced by temperature shift-down to 36.5 degrees C. The induced virus grew very poorly and was inactivated very rapidly at 40.5 degrees C. Non-irradiated virus failed to establish latency at 40.5 degrees C in infected cells. Enhanced reactivation of HSV-2 was observed when latently infected cultures were superinfected with human cytomegalovirus (HCMV) or irradiated with a small dose of u.v. light at the time of temperature shift-down. HCMV did not enhance synthesis of HSV-2 during a normal growth cycle but did enhance synthesis of u.v.-irradiated HSV-2. These observations suggest that in this in vitro latency system, some HSV genomes damaged by u.v. irradiation were maintained in a non-replicating state without being destroyed or significantly repaired.

Histopathological studies on antitumor effect of sporamycin. Cell-mediated immunity against allogeneic tumor-bearing mice

Mice that had received transplants of sarcoma-180 followed by treatment with sporamycin were examined histopathologically at periodic intervals. A marked degeneration of tumor cells was observed at an early stage after the administration of sporamycin, but the degeneration subsequently ceased and regrowth of the tumor was seen. Marked infiltration of lymphoid cells, granulation tissue, and fibrosis was seen in the stroma or surrounding tissue of the tumor at a late stage after the administration of sporamycin, and the regression of tumor cells became marked. With a few exceptions the mice were completely cured by about the 40th day. In the peripheral lymphoid tissues, a transitory decrease in the number of cells was observed after the administration of sporamycin, but this was followed by regeneration of the cells, followed by a marked increase in the B cell system. On the other hand, lymphoid cell depletion of the thymus had persisted. Transplantation of intact sarcoma-180 to mice preliminarily inoculated with sporamycin-treated sarcoma-180 cells resulted in inhibition of tumor growth in most of the mice, and qualitatively the same tissue reactions as those in mice cured of sarcoma-180 by sporamycin were seen. The results suggest that enhancement both of antigenicity of the tumor (cells) and of the subsequent immune response of the host by sporamycin may be involved in the cure of the experimental tumor.

BBM-928, a new antitumor antibiotic complex. I. Production, isolation, characterization and antitumor activity

A complex of the antitumor antibiotic BBM-928 was produced by an actinomycete strain No. G455-101. Four components, BBM-928 A, B, C and D, were isolated in crystalline form and characterized. They were shown to be cyclic depsipeptide antibiotics containing a quinoline nucleus as the chromophore. BBM-928 A is a monoacetyl derivative of BBM-928 B and a diacetyl derivative of BBM-928 C. BBM-928 components exhibit antimicrobial activity against Gram-positive and acid-fast bacteria. BBM-928 A is highly active in mice against various experimental tumors including leukemia P388, leukemia L1210, melanoma B16, LEWIS lung carcinoma and sarcoma 180. BBM-928 B is less active than BBM-928 A, and BBM-928 C has no antitumor activity.

[Studies for a sensitive radioimmunoassay of beta1-Sp1-glycoprotein (SP1) (author's transl)]

In order to measure beta1-SP1-glycoprotein (SP1), on RIA system by the 2-antibody method was established as a measuring method of the low concentration range. SP1 concentrations were measured by this method in the sera of women in early pregnancy, in the amniotic fluids of late pregnancy, in the sera of malignant tumour patients. Furthermore, SP1 concentrations in the sera of women in early pregnancy as well as E2, E3, progesterone and HCG concentrations in the same samples were measured, and correlations between them were examined. 1) The minimum sensitivity of this measuring system was 3ng/ml. The optimum concentration of samples was between 10 approximately 660ng/ml. 2) The correlation between the data obtained by this RIA method and the SRID method was as close as r = 0.9287. 3) SP1 concentrations in the sera of women in early pregnancy were 0.17 +/- 0.12 microgram/ml in the fifth week of pregnancy, showing an almost straight increase during the course of pregnancy, and were 31.62 +/- 3.20 microgram/ml in the 13th week of pregnancy. 4) SP1 concentrations in amniotic fluids were 1.09 approximately 2.20 microgram/ml and were equal to about 1% of SP1 concentrations in the sera of women in late pregnancy. SP1 concentrations in the sera of umbilical cord blood were 0.13 approximately microgram/ml, which were equal to about 0.1% of SP1 concentrations in the sera of women in late pregnancy. 5) SP1 was detected in all four samples of the choriocarcinoma patients' sera, and the concentrations were 25 approximately 2,600ng/ml. Sp1 was detected in 6 of the 15 samples of the cervical carcinoma patients' sera, and the detection rate was 40%. SP1 was detected in 3 of the 6 samples of the leukemia patients' sera and 1 of the 4 samples of the prostatic cancer patients' sera. SP1 detection rates and concentrations appeared to increase in the sera of cervical carcinoma and leukemia patients in accordance with the progress of the diseases. SP1 concentrations in the sera of women in early pregnancy were not correlative to measured E2 and E3 concentrations in the same samples, but there was a significant correlation with progesterone and HCG concentrations. The RIA method for measuring SP1, which we have established, is available for measuring SP1 in the low concentration range. The method is expected to be applied clinically, such as in examinations in early pregnancy, and will be available in fundamental studies such as attempts to measure the SP1 movement in malignant tumour patients, in cooperation with studies of the meaning of SP1 production at pregnancy.

Role of humoral antibodies in resistance to Mycoplasma pneumoniae pneumonia in hamsters

Golden Syrian hamsters adoptively immunized with hyperimmune Mycoplasma pneumoniae rabbit antiserum, immunoglobulin (Ig) M-rich (IgM) fraction, IgG-rich (IgG) fraction, antiserum absorbed with either killed M. pneumoniae or killed Staphylococcus aureus organisms, or antiserum treated with 2-mercaptoethanol (2-ME) were examined for resistance against aerosol infection with virulent M. pneumoniae. Significant resistance to the establishment of infection in the respiratory tract was shown in hamsters pretreated with the untreated antiserum, IgG fraction or 2-ME-treated antiserum, whereas animals pretreated with the IgM fraction and the antisera absorbed with M. pneumoniae or S. aureus organisms were not significantly resistant. Histopathologically, lung lesions were markedly suppressed in animals with high resistance, but were typically pneumonic in animals with low or no resistance. The efficacy of adoptively administered serum preparations was closely related to their antibody titers. The results indicate that humoral antibody plays an important role in protection against experimental M. pneumoniae pneumonia in hamsters, although the participation of the cell-mediated immune response was not determined.

Influence of trypsin on the infectivity and biological properties or parainfluenza type 2 type 2 (croup-associated) virus in Vero cells

A comparative study on the infectivity and biological activities of parainfluenza virus type 2 revealed that one strain (Toshiba) showed c.p.e. with cell fusion and produced plaques in Vero cells, an established line of African green monkey kidney cells. Another strain (62-M786) of this virus, however, showed minimum c.p.e. and produced almost no plaques in Vero cells, although c.p.e. appeared and plaques were observed following addition of trypsin. The infectivity titre of the latter strain, estimated by 50% tissue culture infectious doses (TCID50), was increased 10 times and plaque counts more than 6400 times by addition of an adequate concentration of trypsin; however, trypsin did not affect the infectivity of the former strain. Trypsin also increased the haemolytic activity of strain 62-M786 but not that of the Toshiba strain. These results show that the two isolates of parainfluenza virus type 2 were affected very differently by trypsin as regards infectivity, cell fusion and haemolytic activity.

Inhibition of herpes simplex virus type 2-induced biochemical transformation by interferon

The effect of interferon on the biochemical transformation of thymidine kinase-deficient cells by UV-inactivated herpes simplex virus type 2 has been studied. Transformation was much less sensitive to the action of interferon than virus multiplication. However, the continuous presence of a high dose of interferon (2,000 U) inhibited transformation almost completely. Although we could not differentiate between the effect of interferon on fixation and expression of the virus thymidine kinase gene, data suggest that the inhibitory effect of interferon on transformation might be partially due to the suppression of virus thymidine kinase expression.

[Mechanism of action of certain fibrinolytic bis-tetrahydroisoquinolines: their antagonists and histamine- and 5-hydroxytryptamine-releasing effects (author's transl)]

1, 1'-Heptamethylene-bis-6, 7-dimethoxy-1, 2, 3, 4-tetrahydroisoquinoline (HBDT) and 1, 1'-tetramethylene-bis-6, 7-dimethoxy-1, 2, 3, 4-tetrahydroisoquinoline (bisobrin) produced an edema when given subcutaneously into the hind paws of rats. The inhibitory effects of various antagonists on the paw edema and fibrinolysis induced by HBDT were examined in rats to determine whether chemical mediators other than histamine were involved. The relation of histamine to the fibrinolytic activity of these bis-tetrahydroisoquinoline derivatives has already been reported. Both edema and fibrinolysis were significantly inhibited by pretreatment with promethazine, cyproheptadine or phentolamine, but not by dibenamine, propranolol, atropine, indomethacin or pyridinolcarbamate. epsilon-Aminocaproic acid inhibited the fibrinolytic activity completely without any effect on the paw edema. HBDT released 5-hydroxytryptamine (5-HT) along with histamine from rat peritoneal mast cells. However, the amount of released 5-HT was considerably smaller than that of histamine. These results suggested that bis-tetrahydroisoquinolines released both histamine and 5-HT and that these mediators produced paw edema and induced fibrinolysis by enhancement of plasmin production.

Isolation and characterization of heat-resistant (HR) mutants of Newcastle disease virus

Heat-resistant (HR) mutants (MR 70 and HR 74) of Newcastle disease virus (NDV) which exhibited significantly higher thermostability in their infectivity than wild-type virus were isolated and characterized. They differ from each other in their plaque morphology; HR 70 produces small turbid plaques, whereas those of HR 74 are large and clear. Cytopathogenicity of these mutants is much lower than that of the wild-type virus in cultured cells such as CEF, LLCMK2 and HeLa cells. Moreover, these HR mutants exhibited extended mean embryo survival times. Synthesis of cellular RNA's and proteins in cells infected with HR mutants was not significantly reduced under conditions in which synthesis of these macromolecules was strongly reduced in cells infected with wild-type virus. No significant differences were observed between HR mutants and wild-type virus in their other phenotypic characteristics such as the capacity for interferon production, growth characteristics at a low multiplicity of infection, and cleavage of viral glycoproteins in infected cells. From these findings, it was suggested that the inhibitory effect of virus infection on cellular macromolecular synthesis is a possible determinant of cytopathogenicity of NDV.

Immune interferon produced in vitro as a quantitative indicator of cell-mediated immunity

The present study was constructed to provide some information on the possibility of utilizing immune interferon as a quantitative indicator of cell-mediated immunity and to clarify some of the nature of immune interferon-producing cells (IIPC). When spleen cells derived from L cell-sensitized mice were co-cultivated with L cells, interferon appeared in the culture fluid. It was shown by additional experiments that the cells responsible for immune interferon production in this system were T-lymphocytes assisted by macrophages. The pattern of kinetics of immune interferon production in vitro was similar to that of migration inhibitory factor or T cell-mediated cytotoxicity.

Anticellular effects of 9-(2-hydroxyethoxymethyl) guanine against herpes simplex virus-transformed cells

The guanine derivative 9-(2-hydroxyethoxymethyl) guanine (acycloguanosine), a potent inhibitor of herpes simplex virus (HSV) multiplication, was found to have marked anticellular activity against HSV-transformed thymidine kinase-positive cells. HSV type I-transformed cells were more sensitive to the drug than HSV type 2-transformed cells.

Regulation of persistent infection with herpes simplex virus in vitro by hydrocortisone

About 1% of Raji cells showed sensitivity to herpes simplex virus type 2 (HSV-2) infection when tested by infectious center assays or immunofluorescence tests, and the percentage did not change during cell passage. The addition of hydrocortisone to Raji cells persistently infected with HSV-2 caused a marked increase in virus production and in the number of HSV-producing cells. In the case of HSV-1, it was shown that the addition of hydrocortisone was required to maintain persistent infection. These observations suggest that control of replication of HSV-1 and HSV-2 in these cells is regulated by different mechanisms.

Tumor development in lung of ddY mice following transplacental exposure to 1-ethyl-1-nitrosourea

Transplacental induction of lung tumor by 1-ethyl-1-nitrosourea (ENU) was studied in pregnant ddY mice which were given a single intraperitoneal injection of 58.5 mg/kg of ENU in water between day 13 and 19 of gestation. Within 4 approximately 6 weeks after birth, pulmonary tumor nodules were found in all offsprings exposed to ENU, and they were histopathologically adenoma. Number of tumor nodules could be counted under the stereomicroscope from approximately day 40 after birth. The size of tumor increased with the lapse of time but the number of tumor nodules did not increase markedly. Weekly injections of urethan or ENU into mice pretreated with ENU in their fetal age enhanced the number of pulmonary adenoma. The development of other tumor was not seen except a few cases of lymphoma. Tumor development in the lung by injection of ENU in ddY mice during gestation is reproducible, relatively simple, and rapid. Therefore, it is considered that this may be a useful method for screening of antitumor agent.

Interferon susceptibility of various cell lines persistently infected with haemagglutinating virus of Japan (HVJ)

Various cell lines persistently infected with para-influenza 1 virus, HVJ strain, were less susceptible to the antiviral action of interferon than the same cell lines when not infected with HVJ. When Vero cells persistently infected with a temperature-sensitive strain of HVJ were incubated at 38 degrees C, a non-permissive temperature, they became fully susceptible to interferon, whereas neither the haemadsorbing nor the cell-associated haemagglutinating activity of the virus was expressed. These findings suggest that the lowered interferon susceptibility of virus-carrier cells may be related to the maturation of virus in them. It was found that the low susceptibility of virus-carrier cells to interferon is not due to blocked adsorption of interferon or to inability of the cells to respond tointerferon. Studies with actinomycin D suggest that some step (or steps) before the synthesis of the messenger RNA for the antiviral protein is blocked.