Combined nighttime ultraviolet B irradiation and phytoseiid mite application provide optimal control of the spider mite Tetranychus urticae on greenhouse strawberry plants

BACKGROUND

Tetranychus urticae is a hard-to-control pest of greenhouse strawberry production. Nighttime ultraviolet B (UV-B) radiation using light reflection sheets (LRS) has been applied as a physical method to control T. urticae through direct ovicidal effects (the UV method). However, because strawberry leaves grow more densely, UV-B radiation fails to reach the lower leaf surfaces inhabited by spider mites; therefore, a complementary method is required. We propose the supplemental application of phytoseiid mites in greenhouse strawberry production. We evaluated the control effects of UV-B irradiation, phytoseiid mite application and their combined use. The effects of UV-B irradiation on the degree of overlap relative to the independent distributions (ω) between predators and prey were also analyzed.

RESULTS

The UV method alone maintained low T. urticae density levels from November to February; however, mite populations increased from March onward. Phytoseiid mite application in January and February without UV-B irradiation resulted in a temporary increase in spider mites in March and/or April. By contrast, combined application of the UV method and phytoseiid mites had a greater control effect during the strawberry growing season. The ω values were higher for the UV method compared with no UV-B irradiation, suggesting that UV-B irradiation increased phytoseiid mite foraging rates.

CONCLUSION

The release of phytoseiid mites compensated for the shortcomings of the UV method, and UV-B irradiation promoted predation by phytoseiid mites by increasing the behavioral numerical response. Consequently, combined application of UV-B irradiation and phytoseiid mites is optimal for T. urticae control in greenhouse strawberry production. © 2023 Society of Chemical Industry.

Phylogenetic and phylodynamic analyses of hepatitis C virus subtype 1a in Okinawa, Japan

Okinawa Island, located in Southern Japan, has a higher prevalence rate of hepatitis C virus subtype 1a (HCV-1a) infection than that in mainland Japan. Okinawa has a history of US military occupation after World War II. To elucidate the transmission history of HCV-1a in Okinawa, 26 whole-genome sequences were obtained from 29 patients during 2011-2016. Phylogenetic trees were reconstructed to identify the origin and characteristics of HCV-1a in Okinawa with epidemiological information. A phylogenetic tree based on whole-genome sequencing revealed that all of the samples were located below the US branches. Additionally, we identified one cluster comprised of 17 strains (Okinawa, n = 16; United States, n = 1). The majority of the patients in this cluster were people who inject drugs (PWID), indicating the presence of a people who inject drugs (PWID) cluster. Subsequently, Bayesian analyses were employed to reveal viral population dynamics. Intriguingly, a phylodynamic analysis uncovered a substantial increase in effective population size of HCV-1a from 1965 to 1980 and a slight increase in mid-2000, which were associated with an increase in illicit drug use in Okinawa. The estimated divergence time of the PWID cluster was 1967.6 (1964.2-1971.1). These findings suggest that HCV-1a was introduced into Okinawa from the United States in the late 1960s, coincident with the Vietnam War. Subsequently, HCV-1a might have spread among the Japanese population with the spread of injecting drug use. Our study provides an understanding of HCV transmission dynamics in Okinawa, as well as the key role of PWID in HCV transmission.

Physical Control of Spider Mites Using Ultraviolet-B With Light Reflection Sheets in Greenhouse Strawberries

Development of spider mite management technology other than chemical control is desired because of the serious development of acaricide resistance worldwide. Recent studies have evidenced the lethal effects of ultraviolet-B (UVB) radiation on spider mites. To develop the technology on how to use UVB irradiation for spider mite control, we tested whether UVB lamp-light reflection sheet (LRS) combinations suppressed the population size of Tetranychus urticae Koch on strawberry in a greenhouse from December to May (2012-2013, 2013-2014) in Japan. We designed four combinations of UVB lamps and LRSs: 1) neither UVB lamps nor LRSs (UV-LRS-); 2) a UVB lamp without an LRS (UV+LRS-; 2012-2013 only); 3) a UVB lamp and a mulch-type LRS (UV+LRSm); and 4) a UVB lamp and a wing-type LRS (UV+LRSw). The number of adult females peaked at 438.0 and 222.0 per plant in UV-LRS- of 2012-2013 and 2013-2014, respectively, and peaked at 191.6 females in UV+LRS- of 2012-2013. In contrast, the peak abundance was 20.9-98.0 females in UV+LRSm, and fewer than 15 females were noted in UV+LRSw over either experimental period. UVB irradiance on lower leaf surfaces was higher in UV+LRSm and UV+LRSw than UV-LRS- and UV+LRS-, and the mite densities were significantly correlated with UVB irradiance on lower leaf surfaces. Consequently, we conclude that the combinations of UVB lamp-LRS have an excellent capacity to control T. urticae on greenhouse strawberry, and that the LRS was an essential component in this technological approach.

Risk factors for hepatocellular carcinoma in hepatitis C patients with normal alanine aminotransferase treated with pegylated interferon and ribavirin

Pegylated interferon (Peg-IFN) plus ribavirin combination therapy is effective in patients with hepatitis C virus (HCV) infection and normal alanine aminotransferase levels (NALT). However, it remains unclear whether the risk of hepatocellular carcinoma (HCC) incidence is actually reduced in virological responders. In this study, HCC incidence was examined for 809 patients with NALT (ALT ≤ 40 IU/mL) treated with Peg-IFN alpha-2b and ribavirin for a mean observation period of 36.2 ± 16.5 months. The risk factors for HCC incidence were analysed by Kaplan-Meier method and Cox proportional hazards model. On multivariate analysis among NALT patients, the risk of HCC incidence was significantly reduced in patients with sustained virological response (SVR) or relapse compared with those showing nonresponse (NR) (SVR vs NR, hazard ratio (HR): 0.16, P = 0.009, relapse vs NR, HR: 0.11, P = 0.037). Other risk factors were older age (≥65 years vs <60 years, HR: 6.0, P = 0.032, 60-64 vs <60 years, HR: 3.2, P = 0.212) and male gender (HR: 3.9, P = 0.031). Among 176 patients with PNALT (ALT ≤ 30 IU/mL), only one patient developed HCC and no significant risk factors associated with HCC development were found. In conclusion, antiviral therapy for NALT patients with HCV infection can lower the HCC incidence in responders, particularly for aged and male patients. The indication of antiviral therapy for PNALT (ALT ≤ 30 IU/mL) patients should be carefully determined.

α-Fetoprotein impairs activation of natural killer cells by inhibiting the function of dendritic cells

α-Fetoprotein (AFP) is a tumour-associated antigen in hepatocellular carcinoma (HCC). The biological properties of AFP have been identified in its regulatory effects on immune responses of T cells and B cells. However, AFP effects on natural killer (NK) cells are still unclear. In this study, we examined the immunoregulation of AFP on NK activity. The cytolytic activity against K562 cells and Huh7 cells of NK cells co-cultured with AFP-treated dendritic cells (DCs) (AFP-DCs) was lower than that with albumin-treated DCs (Alb-DCs). Direct addition of AFP to NK cells did not alter the cytolytic activity of NK cells. Adding AFP inhibited the interleukin (IL)-12 production of DCs after stimulation with lipopolysaccharide (LPS) [Toll-like receptor (TLR)-4 ligand], or Poly(I:C) (TLR-3 ligand), but not IL-18 production. The mRNAs of IL-12p35 and IL-12p40 were significantly inhibited in AFP-DCs compared with Alb-DCs, but those of TLR-4 or TLR-3 were not. Transwell experiments revealed that soluble factors derived from DCs played roles in inhibition of the ability of activating NK cells by AFP-DCs. Adding the neutralizing antibody of IL-12 to NK cells co-cultured with Alb-DCs resulted in a decrease of cytolytic activity to the levels of NK cells co-cultured with AFP-DCs. Adding IL-12 to NK cells co-cultured with AFP-DCs resulted in an increase of cytolytic activity to the levels of NK cells co-cultured with Alb-DCs. These demonstrated that the impairment of IL-12 production from AFP-DCs resulted in inhibition of the ability of the activation of NK cells by DCs, and thus suggests a role of AFP in HCC development.

Factors affecting efficacy in patients with genotype 2 chronic hepatitis C treated by pegylated interferon alpha-2b and ribavirin: reducing drug doses has no impact on rapid and sustained virological responses

Reducing the dose of drug affects treatment efficacy in pegylated interferon (Peg-IFN) and ribavirin combination therapy for patients with hepatitis C virus (HCV) genotype 1. The aim of this study was to investigate the impact of drug exposure, as well as the baseline factors and the virological response on the treatment efficacy for genotype 2 patients. Two-hundred and fifty patients with genotype 2 HCV who were to undergo combination therapy for 24 weeks were included in the study, and 213 completed the treatment. Significantly more patients who achieved a rapid virological response (RVR), defined as HCV RNA negativity at week 4, achieved a sustained virological response (SVR) (92%, 122/133) compared with patients who failed to achieve RVR (48%, 38/80) (P < 0.0001). Multivariate logistic-regression analysis showed that only platelet counts [odds ratio (OR), 1.68; confidence interval (CI), 1.002-1.139] and RVR (OR, 11.251; CI, 5.184-24.419) were independently associated with SVR, with no correlation being found for the mean dose of Peg-IFN and ribavirin for RVR and SVR. Furthermore, in the stratification analysis of the timing of viral clearance, neither mean dose of Peg-IFN (P = 0.795) nor ribavirin (P = 0.649) affected SVR in each group. Among the patients with RVR, the lowest dose group of Peg-IFN (0.77 +/- 0.10 microg/kg/week) and ribavirin (6.9 +/- 0.90 mg/kg/day) showed 100% and 94% of SVR. Hence, RVR served as an important treatment predictor, and drug exposure had no impact on both SVR and RVR in combination therapy for genotype 2 patients.

Enhanced ability of regulatory T cells in chronic hepatitis C patients with persistently normal alanine aminotransferase levels than those with active hepatitis

In hepatitis C virus (HCV) infection, the Th1-type immune response is involved in liver injury. A predominance of immunosuppressive regulatory T cells (Treg) is hypothesized in patients with persistently normal alanine aminotransferase (PNALT). Our aim was to clarify the role of Treg in the pathogenesis of PNALT. Fifteen chronically HCV-infected patients with PNALT, 21 with elevated ALT (CH) and 19 healthy subjects (HS) were enrolled. We determined naturally-occurring Treg (N-Treg) as CD4+CD25high+FOXP3+ T cells. The expression of FOXP3 and CTLA4 in CD4+CD25high+ cells was quantified by real-time reverse transcriptase-polymerase chain reaction. Bulk or CD25-depleted CD4+ T cells cultured with HCV-NS5 loaded dendritic cells were assayed for their proliferation and cytokine release. We examined CD127-CD25-FOXP3+ cells as distinct subsets other than CD25+ N-Treg. The frequencies of N-Treg in patients were significantly higher than those in HS. The FOXP3 and CTLA4 transcripts were higher in PNALT than those in CH. The depletion of CD25+ cells enhanced HCV-specific T cell responses, showing that co-existing CD25+ cells are suppressive. Such inhibitory capacity was more potent in PNALT. The frequency of CD4+CD127-CD25-FOXP3+ cells was higher in CH than those in PNALT. Treg are more abundant in HCV-infected patients, and their suppressor ability is more potent in patients with PNALT than in those with active hepatitis.

Pegylated interferon alpha-2b (Peg-IFN alpha-2b) affects early virologic response dose-dependently in patients with chronic hepatitis C genotype 1 during treatment with Peg-IFN alpha-2b plus ribavirin

Chronic hepatitis C (CH-C) genotype 1 patients who achieved early virologic response have a high probability of sustained virologic response (SVR) following pegylated interferon (Peg-IFN) plus ribavirin therapy. This study was conducted to evaluate how reducing drug doses affects complete early virologic response (c-EVR) defined as hepatitis C virus (HCV) RNA negativity at week 12. Nine hundred eighty-four patients with CH-C genotype 1 were enrolled. Drug doses were evaluated independently on a body weight base from doses actually taken. From multivariate analysis, the mean dose of Peg-IFN alpha-2b during the first 12 weeks was the independent factor for c-EVR (P = 0.02), not ribavirin. The c-EVR rate was 55% in patients receiving > or = 1.2 microg/kg/week of Peg-IFN, and declined to 38% at 0.9-1.2 microg/kg/week, and 22% in patients given <0.9 microg/kg/week (P < 0.0001). Even with stratified analysis according to ribavirin dose, the dose-dependent effect of Peg-IFN on c-EVR was observed, and similar c-EVR rates were obtained if the dose categories of Peg-IFN were the same. Furthermore, the mean dose of Peg-IFN during the first 12 weeks affected HCV RNA negativity at week 24 (P < 0.0001) and SVR (P < 0.0001) in a dose-dependent manner. Our results suggest that Peg-IFN was dose-dependently correlated with c-EVR, independently of ribavirin dose. Thus, maintaining the Peg-IFN dose as high as possible during the first 12 weeks can yield HCV RNA negativity and higher c-EVR rates, leading to better SVR rates in patients with CH-C genotype 1.

Ribavirin dose reduction raises relapse rate dose-dependently in genotype 1 patients with hepatitis C responding to pegylated interferon alpha-2b plus ribavirin

The impact of ribavirin exposure on virologic relapse remains controversial in combination therapy with pegylated interferon (Peg-IFN) and ribavirin for patients with chronic hepatitis C (CH-C) genotype 1. The present study was conducted to investigate this. Nine hundred and eighty-four patients with CH-C genotype 1 were enrolled. The drug exposure of each medication was calculated by averaging the dose actually taken. For the 472 patients who were HCV RNA negative at week 24 and week 48, multivariate logistic regression analysis showed that the degree of fibrosis (P = 0.002), the timing of HCV RNA negativiation (P < 0.001) and the mean doses of ribavirin (P < 0.001) were significantly associated with relapse, but those of Peg-IFN were not. Stepwise reduction of the ribavirin dose was associated with a stepwise increase in relapse rate from 11% to 60%. For patients with complete early virologic response (c-EVR) defined as HCV RNA negativity at week 12, only 4% relapse was found in patients given > or = 12 mg/kg/day of ribavirin and ribavirin exposure affected the relapse even after treatment week 12, while Peg-IFN could be reduced to 0.6 microg/kg/week after week 12 without the increase of relapse rate. Ribavirin showed dose-dependent correlation with the relapse. Maintaining as high a ribavirin dose as possible (> or = 12 mg/kg/day) during the full treatment period can lead to suppression of the relapse in HCV genotype 1 patients responding to Peg-IFN alpha-2b plus ribavirin, especially in c-EVR patients.

Impaired ability of interferon-alpha-primed dendritic cells to stimulate Th1-type CD4 T-cell response in chronic hepatitis C virus infection

In interferon-alpha (IFN-alpha)/ribavirin combination therapy for chronic hepatitis C (CHC), an enhanced T helper 1 (Th1) response is essential for the eradication of hepatitis C virus (HCV). We aimed to elucidate the role of IFN-alpha or IFN-alpha/ribavirin in dendritic cell (DC) ability to induce Th1 response in HCV infection. We generated monocyte-derived DC from 20 CHC patients and 15 normal subjects driven by granulocyte-macrophage colony-stimulating factor and interleukin 4 (IL-4) without IFN-alpha (GM/4-DC), with IFN-alpha (IFN-DC), with ribavirin (R-DC) or with IFN-alpha/ribavirin (IFN/R-DC) and compared their phenotypes and functions between the groups. We also compared them in 14 CHC patients between who subsequently attained sustained virological response (SVR) and who did not (non-SVR) by 24 weeks of IFN-alpha/ribavirin therapy. Compared with GM/4-DC, IFN-DC displayed higher CD86 expression, but lesser ability to secrete IL-10 and were more potent to prime CD4(+) T cells to secrete IFN-gamma and IL-2. Such differences were more significant in healthy subjects than in CHC patients. No additive effect of ribavirin was observed in DC phenotypes and functions in vitro either which was used alone or in combined with IFN-alpha. However, in the SVR patients, an ability of IFN/R-DC to prime T cells to secrete IFN-gamma and IL-2 was higher than those of IFN-DC and those of IFN/R-DC in the non-SVR group, respectively. In conclusion, DC from CHC patients are impaired in the ability to drive Th1 in response to IFN-alpha. Such DC impairment is restored in vitro by the addition of ribavirin in not all but some patients who cleared HCV by the combination therapy.

A single nucleotide polymorphism of the low molecular mass polypeptide 7 gene influences the interferon response in patients with chronic hepatitis C

Transporter associated with antigen processing (TAP) and low molecular mass polypeptides (LMP) play crucial roles in the human leukocyte antigen (HLA) class I-restricted antigen presenting systems. This study was performed to elucidate whether these antigen-presenting gene polymorphisms could influence the response to interferon (IFN) treatment in patients with chronic hepatitis C. Polymorphisms of TAP and LMP genes in 175 hepatitis C virus (HCV) patients were determined by polymerase chain reaction-restriction fragment length polymorphism. The frequencies of these genes were compared between sustained-responders (n=49) and nonresponders (n=126), classified by biochemical and virological responses to IFN. The distributions of TAP1*, TAP2*, and LMP2 genes between sustained-responders and nonresponders did not differ. However, LMP7-K gene frequency in sustained-responders was higher than that in nonresponders [odds ratio 2.3 (95% confidence interval 1.1-4.6); 16%vs 7.9%]. Multivariate analysis revealed that LMP7-K and HCV-RNA quantity were independent factors influencing the outcome of IFN therapy [4.5 (1.4-14); P=0.011, 0.40 (0.24-0.65); P=0.0003, respectively]. Furthermore, among patients with a low viral load (< or = 2.0 Meq/mL), the LMP7-K positive patients had an even higher ratio of sustained response compared to those without LMP7-K [5.9 (1.6-22); 82%vs 44%; P=0.0062]. These findings suggest that a single nucleotide polymorphism of LMP7 gene is one of the important host factors which independently influence the response to IFN in patients with chronic hepatitis C.

Administration of interleukin-12 enhances the therapeutic efficacy of dendritic cell-based tumor vaccines in mouse hepatocellular carcinoma

Dendritic cells (DCs) are potent antigen-presenting cells that are capable of priming systemic antitumor immune response. Here, we evaluated the combined effectiveness of tumor lysate-pulsed DC immunization and interleukin (IL)-12 administration on the induction of antitumor immunity in a mouse hepatocellular carcinoma (HCC) model. Mouse DCs were pulsed with lysate of BNL 1ME A.7R.1 (BNL), a BALB/c-derived HCC cell line, and then injected into syngeneic mice in combination with systemic administration of IL-12. Lymphocytes from mice treated with BNL lysate-pulsed DCs and IL-12 showed stronger cytolytic activity and produced higher amounts of IFN-gamma than those from mice treated with BNL lysate-pulsed DCs alone. Although immunization with BNL lysate-pulsed DCs alone did not lead to complete regression of established tumors, it significantly inhibited tumor growth compared with vehicle injection. Importantly, the combined therapy of BNL lysate-pulsed DCs and IL-12 resulted in tumor rejection or significant inhibition of tumor growth compared with mice treated with BNL lysate-pulsed DCs alone. In vivo lymphocyte depletion experiments demonstrated that this combination was dependent on both CD8+ and CD4+ T cells, but not natural killer cells. These results demonstrated that IL-12 administration enhanced the therapeutic effect of immunization of tumor lysate-pulsed DCs against HCC in mice. This combination of IL-12 and DCs may be useful for suppressing the growth of residual tumor after primary therapy of human HCC.

Ceramide mediates tumor-induced dendritic cell apoptosis

Induction of apoptosis in dendritic cells (DC) is one of the escape mechanisms of tumor cells from the immune surveillance system. This study aimed to clarify the underlying mechanisms of tumor-induced DC apoptosis. The supernatants (SN) of murine tumor cell lines B16 (melanoma), MCA207, and MCA102 (fibrosarcoma) increased C16 and C24 ceramide as determined by electrospray mass spectrometry and induced apoptosis in bone marrow-derived DC. N-oleoylethanolamine or D-L-threo 1-phenyl-2-decanoylamino-3-morpholino-1-propanol (PDMP), which inhibits acid ceramidase or glucosylceramide synthase and then increases endogenous ceramide, enhanced DC apoptosis and ceramide levels in the presence of tumor SN. Pretreatment with L-cycloserine, an inhibitor of de novo ceramide synthesis, or phorbol ester, 12-O-tetradecanoylphorbol-13-acetate reduced endogenous ceramide levels and protected DC from tumor-induced apoptosis. However, other DC survival factors, including LPS and TNF-alpha, failed to do so. The protective activity of 12-O-tetradecanoylphorbol-13-acetate is abrogated by pretreatment with phosphoinositide 3-kinase (PI3K) inhibitor, LY294002. Therefore, down-regulation of PI3K is the major facet of tumor-induced DC apoptosis. Tumor SN, N-oleoylethanolamine, or PDMP suppressed Akt, NF-kappaB, and bcl-x(L) in DC, suggesting that the accumulation of ceramide impedes PI3K-mediated survival signals. Taken together, ceramide mediates tumor-induced DC apoptosis by down-regulation of the PI3K pathway.

Generation of hepatitis C virus-specific cytotoxic T lymphocytes from healthy individuals with peptide-pulsed dendritic cells

BACKGROUND AND AIMS

In hepatitis C virus (HCV) infection, cytotoxic T lymphocytes (CTL) are involved in liver inflammation and contribute to the reduction of viral load. Antibodies for HCV-CTL precursor frequencies (CTLpf) are relatively low in chronic hepatitis C, and this may be related to the poor CTL response in vivo. The aim of this study was to assess the efficacy of dendritic cells (DC) as antigen-presenting cells in CTL generation from low CTLpf.

METHODS

To confirm the rationale of using DC to prime naive T cells, five HCV-uninfected individuals were enrolled in the study. We obtained DC by maturation from peripheral progenitors under stimulation with granulocyte-macrophage colony-stimulating factor (GM-CSF), interleukin (IL)-4 and IL-1alpha. Autologous T cells were cultured with DC or concanavalin-A-induced blasts loaded with four HCV-derived peptides bearing human leukocyte antigen (HLA)-A*0201 or -A24 motifs for 28 days under IL-7 and IL-2 stimulation. The lytic activity against peptide-pulsed targets was assessed by using a [51Cr]-releasing assay.

RESULTS

The DC strongly expressed HLA class I, II, B7-1 and B7-2, but not phenotypic markers of T-, B-, natural killer (NK)-cells or monocytes. The CD8-positive, HLA-class I-restricted and HCV peptide-specific CTL were generated with DC from HLA-A antigen-matched subjects, whereas no CTL activity was detected with concavalin (Con-A) blasts. We were thus able to generate HCV specific CTL from naive precursors with peptide-pulsed DC.

CONCLUSIONS

This DC-based system can be used to generate CTL of desired antigen specificity, even from a source with low CTLpf.

Interleukin 1beta protects mice from Fas-mediated hepatocyte apoptosis and death

BACKGROUND & AIMS

Fas-mediated apoptosis is one of the major death processes of hepatocytes in liver diseases. The aim of this study was to determine whether interleukin (IL)-1beta regulates the Fas-mediated apoptotic process of differentiated hepatocytes in vivo.

METHODS

IL-1beta was injected into Balb/cA mice 5 hours before lethal challenge with agonistic anti-Fas administration. Survival and hepatocyte apoptotic process of these mice were examined.

RESULTS

IL-1beta pretreatment prolonged animal survival in a dose-dependent manner, and 500 ng of IL-1beta completely protected mice from lethality. Both serum alanine aminotransferase value and hepatic DNA fragmentation were significantly suppressed by IL-1beta pretreatment. IL-1beta affected neither hepatic distribution of anti-Fas antibody nor Fas expression levels on hepatocytes but significantly suppressed Fas-induced activation of hepatic caspase 3-like protease. Suppression of Fas-induced activation of the caspase by IL-1beta was diminished by coadministration with D-galactosamine and reversed by coinjection with an excess amount of uridine.

CONCLUSIONS

These results suggest that IL-1beta suppresses Fas-mediated hepatocyte apoptosis by inducing molecule(s) that suppress the apoptosis control machinery upstream of caspase 3. This observation raises the possibility that IL-1beta acts as a negative regulator of Fas-mediated hepatocyte apoptosis during liver injury.

B7-1 (CD80)-gene transfer combined with interleukin-12 administration elicits protective and therapeutic immunity against mouse hepatocellular carcinoma

Human hepatocellular carcinoma (HCC) frequently recurs after primary therapy, resulting in poor prognosis. To try to find a way to prevent this, we examined the combined effectiveness of B7-1 (CD80)-gene transfer and interleukin-12 (IL-12) on the induction of protective antitumor immunity against poorly immunogenic BNL1ME A.7R. 1 (BNL) mouse HCC cells. We introduced mouse B7-1 gene into BNL1ME A. 7R.1 cells. Overexpression of B7-1 on BNL1ME A.7R.1 cells resulted in significant inhibititon of subcutaneous tumor development in syngeneic BALB/c mice, but not in complete rejection, suggesting that strong expression of B7-1 molecules may enhance the immunogenicity of BNL1ME A.7R.1 cells in immunocompetent mice. Lymphocyte study revealed that the cytolytic activity generated by immunization with B7-1 transfectants against BNL1ME A.7R.1 cells was mediated mainly by CD8(+) cytotoxic T lymphocytes (CTL). We examined the synergistic effect of IL-12 and immunization with B7-1 transfectants. The combination led to rejection of BNL1ME A.7R.1 cells in 6 of 10 tested mice and delayed tumor development in the remaining mice. Furthermore, the combined treatment against pre-established BNL1ME A.7R.1 tumors resulted in rejection in 3 of 8 tested mice or in significant inhibition of tumor growth in the remaining mice. In vivo lymphocyte subset depletion study indicated that the combined antitumor effect was dependent on the presence of both CD8(+) and CD4(+) T cells. In conclusion, the combination of immunization of B7-1-transfected HCC cells and IL-12 could induce protective and therapeutic immunity against parental HCC cells, and this combination may be therapeutically useful for suppressing recurrence of HCC.

Involvement of transporter associated with antigen processing 2 (TAP2) gene polymorphisms in hepatitis C virus infection

BACKGROUND & AIMS

Transporter associated with antigen processing (TAP) has essential roles in the antigen-presenting systems, translocating antigenic peptides from the cytosol into the endoplasmic reticulum. The aim of this study was to clarify whether TAP polymorphisms are involved in hepatitis C virus (HCV) infection.

METHODS

The 145 HCV-infected Japanese patients examined in this study were categorized into two groups: 36 carriers with persistently normal alanine transaminase (ALT) values and 109 patients with chronic liver disease (CLD). TAP2 gene phenotypes were determined by means of polymerase chain reaction-restriction fragment length polymorphism, and their frequencies were compared between the two groups.

RESULTS

Frequencies of TAP2*0101, *0102, and *0201 were not different between the two groups. However, TAP2*0103 frequency in carriers with normal ALT levels was significantly higher than that in patients with CLD (44% vs. 16%; P = 0.00064, Pc < 0.005). Although the TAP2*0103 allele was tightly linked with class II DRB1*1302-DQB1*0604 haplotype in this study, the TAP2*0103 frequency in the normal ALT group was also significantly higher than that in the CLD group even in DRB1*1302-DQB1*0604-negative patients (31% vs. 10%; P = 0.0076, Pc < 0.05).

CONCLUSIONS

These findings suggest that TAP2*0103 may be closely associated with low serum ALT activity in HCV-infected Japanese patients.

Impaired allostimulatory capacity of peripheral blood dendritic cells recovered from hepatitis C virus-infected individuals

In hepatitis C virus (HCV) infection, Th responses are implicated in the pathogenesis of liver disease. The dendritic cell (DC) is the most potent activator of CD4 T cells for supporting Th1 differentiation. To clarify the roles of DC of HCV-infected individuals in the development of CD4 T cell responses, we generated peripheral DC with GM-CSF and IL-4 from 24 chronic hepatitis C patients and 14 healthy donors. We then compared their potentials for stimulating allogeneic CD4 T cells, autologous CD4 T cells against influenza A or HCV core Ags, and cytokine production. The DC from the patients (HCV-DC) expressed lower degrees of CD86 than DC from the donors (N-DC), whereas no difference was found in the HLA molecules and other costimulators. HCV-DC stimulated allogeneic T cells less than N-DC; however, influenza A- or core-pulsed HCV-DC retained the potentials for autologous T cell proliferation. In allogeneic DC/T cell cultures, the IFN-gamma levels with HCV-DC were lower than those with N-DC, which may be related to the low expressions of IL-12 p35 and p40 transcripts in HCV-DC. The stimulation with LPS disclosed that HCV-DC is less potent in IL-12 p70 production than N-DC. In the autologous cultures, the pulsing of the Ags to HCV-DC increased the IL-12 p40 and IFN-gamma production and up-regulated the transcription of both IL-12 subunits. Exogenous IL-2 or IL-12 restored the low allogeneic T cell proliferation with HCV-DC in a dose-dependent manner. Therefore, low expression of CD86 and/or IL-12 is crucially involved in the low allostimulatory capacity of HCV-DC. Low IL-12 and low IFN-gamma milieu with HCV-DC on encounters with alloantigens may impede Th1 polarization.

Serum levels of soluble Fas antigen in chronic hepatitis C patients

BACKGROUND/AIMS

In chronic hepatitis C, the expression of Fas antigen on hepatocytes is upregulated and Fas ligand expression is detected on liver-infiltrating mononuclear cells. Thus Fas antigen/Fas ligand-mediated apoptosis is thought to be involved in hepatic injury in chronic hepatitis C. The soluble form of Fas antigen has been detected in serum and shown to inhibit Fas-mediated apoptosis. The present study was done to evaluate the relationship of serum soluble Fas antigen levels with disease activity.

METHODS

Serum soluble Fas antigen levels were measured by enzyme-linked immunosorbent assay for 68 chronic hepatitis C patients and compared with those in normal volunteers, chronic hepatitis B patients and autoimmune hepatitis patients. These levels were compared with histological activity, ALT levels, HCV-RNA titer and Fas expression on hepatocytes.

RESULTS

Serum soluble Fas antigen levels in chronic hepatitis C patients (3.24+/-1.55 ng/ml) were significantly higher than those in normal volunteers (1.70+/-1.01 ng/ml) (p<0.01). They showed no difference from those in chronic hepatitis B or autoimmune hepatitis patients. Histologically, soluble Fas antigen levels showed correlation with the levels of liver inflammation (p<0.01). However, no relationship was observed between serum soluble Fas antigen and serum ALT levels or HCV-RNA titer. Serum soluble Fas antigen levels showed correlation with the levels of Fas antigen expression in liver tissue (p<0.05).

CONCLUSIONS

These findings suggest that serum soluble Fas antigen may reflect the expression levels of Fas antigen on hepatocytes and the severity of liver inflammation in chronic hepatitis C.

Cross-linking of Fc(gamma)-receptor on monocytes inhibits hepatitis C virus-specific cytotoxic T-lymphocyte induction in vitro

In hepatitis C virus (HCV) infection, immune complex (IC)-type virus particles are frequently observed in circulation. The IC leads to cross-linking of Fcgamma receptors (FcgammaR) on monocytes and exerts immunoinhibitory function. To test the roles of IC in HCV-specific cytotoxic T lymphocyte (CTL) induction, we generated HCV CTL from peripheral blood mononuclear cells of chronic hepatitis C patients with or without HCV-IC- or immunoglobulin G (IgG)-coated culture plates and compared their lytic activities. HCV-IC or adherent IgG, which induces FcgammaR cross-linking, significantly reduced CTL activity. Expression of B7-1 on monocytes decreased on adherent IgG. In addition, tumour necrosis factor-alpha (TNF-alpha) and transforming growth factor-beta1 (TGF-beta1) production increased from cells on adherent IgG and their mRNA expression in monocytes was enhanced. Anti-TNF-alpha antibody during induction on adherent IgG inhibited lysis; however, anti-TGF-beta completely reversed its inhibitory effect. These results demonstrated that HCV-IC or adherent IgG impaired HCV-CTL induction in vitro. The FcgammaR-mediated CTL suppression occurred via decreased expression of monocyte B7-1 and/or enhanced production of TGF-beta1.

Delayed Fas-mediated hepatocyte apoptosis during liver regeneration in mice: hepatoprotective role of TNF alpha

Fas-mediated apoptosis is one of the major death processes of hepatocytes in liver diseases. Although compensatory regeneration occurs during liver injury, it has not been determined whether regenerating hepatocytes die by the same apoptotic process as quiescent hepatocytes. To clarify this issue, the hepatocyte apoptotic process, after injection of agonistic anti-mouse Fas, was compared between sham-operated mice and two-thirds partially hepatectomized mice. The onset of hepatocyte apoptosis was retarded in hepatectomized mice, as evidenced by both morphological and biochemical observations, resulting in significantly prolonged animal survival. Flow cytometric analysis revealed similar levels of Fas expression on hepatocytes between hepatectomized mice and sham-operated mice; however, the activation of liver caspase-3-like protease after Fas stimulation was suppressed in hepatectomized mice, whereas pro-caspase-3 expression did not change with or without hepatectomy. Anti-tumor necrosis factor alfa (TNF alpha), when administered before hepatectomy, partially reversed suppression of caspase-3-like activity after Fas stimulation. Furthermore, the injection of TNF alpha into untreated mice suppressed caspase-3-like activity and prolonged animal survival after Fas stimulation. These results indicate that Fas-signaling events at the level or upstream of caspase-3-like protease are suppressed during liver regeneration, resulting in delayed hepatocyte apoptosis, and also that TNF alpha acts as one of the protective factors against Fas-mediated hepatocyte apoptosis.

Influence of HLA haplotypes on the clinical courses of individuals infected with hepatitis C virus

The human leukocyte antigen is a crucial genetic factor that initiates or regulates immune response by presenting foreign or self antigens to T lymphocytes. The aim of this study was to investigate whether HLA polymorphism is associated with the onset or progression of liver injury in chronic hepatitis C virus (HCV) infection. We determined HLA class I antigens and class II alleles in 130 hepatitis C virus (HCV)-infected patients (33 carriers with persistently normal alanine transaminase [ALT] values and 97 patients with chronic liver disease [CLD]). HLA class I (A, B) was typed serologically, and class II (DRB1, DQB1) was typed by means of polymerase chain reaction-restriction fragment length polymorphism methods. The frequencies of DRB1*0405 and DQB1*0401 were higher in HCV-infected patients than in uninfected subjects. Among HCV-infected patients, the frequencies of B54, DRB1*0405, and DQB1*0401 were significantly higher in patients with CLD than in those carriers with persistently normal ALT values, whereas DRB1*1302, DRB1*1101, and DQB1*0604 were more frequently found in carriers with persistently normal ALT values than in patients with CLD. From extended haplotype analyses, in carriers with B54-DRB1*0405-DQB1*0401 haplotype, the risk of having liver injury was 13.2 times greater than in carriers with DRB1*0405-DQB1*0401 but without B54 [P = 0.0015, Haldane odds ratio = 13.2 (95% confidence interval, 1.7-103.8)]. In contrast, carriers with B44-DRB1*1302-DQB1*0604 had a 12.7-fold lower relative risk of developing liver injury compared to those with the haplotype containing B44 but not DRB1*1302-DQB1*0604 [P = 0.0076, Haldane odds ratio = 0.079 (0.009-0.695)]. Our findings show that extended haplotypes including class I B54 are closely associated with the progression of liver injury, whereas extended haplotypes including class II DRB1*1302-DQB1*0604 are associated with low hepatitis activity in chronic HCV infection.

Neutralization of transforming growth factor beta 1 augments hepatitis C virus-specific cytotoxic T lymphocyte induction in vitro

In hepatitis C virus (HCV) infection, TGF-beta 1 is upregulated in the liver and may be involved in the pathogenesis of chronic liver disease. TGF-beta 1 is also produced by activated T cells and acts as a potent immunosuppressor. The aim of this study was to investigate the roles of TGF-beta 1 in HCV-specific cytotoxic T lymphocyte (CTL) induction and enhance their killer activity by TGF-beta 1 modulation. We generated anti-HCV CTL from peripheral blood mononuclear cells from HLA-A2 patients under stimulation with the HCV-core peptide having the HLA-A2.1 binding motif. The lytic activities of CTL or precursor frequency (CTLpf) generated with or without anti-TGF-beta antibody were compared. To optimize the IL-2 dose for CTL induction, low (50 U/ml) and high (500 U/ml) doses were tested and the lytic activities were compared. TGF-beta 1 amounts in the supernatants were assessed by enzyme-linked immunosorbent assay and by their growth inhibitory effect on mink lung epithelial cells. CTL activity was enhanced by anti-TGF-beta antibody in a dose-dependent manner but CTLpf did not significantly change. A high dose of IL-2 reduced the activity to 45% of that observed with a low dose, whereas TGF-beta 1 increased as the dose of IL-2 increased. Exogenous IL-10 reversed the inhibitory effect of a high dose of IL-2 on the killing activity by reducing TGF-beta 1 mRNA expression in T cells and its production. These results demonstrated that endogenous TGF-beta 1 is an autocrine suppressor in CTL induction in vitro. Therefore, the blockade of endogenous TGF-beta 1 could enhance the killing potential of anti-HCV CTL.

Expression of costimulatory molecules B7-1 (CD80) and B7-2 (CD86) on human hepatocellular carcinoma

Costimulation mediated by costimulatory molecules, such as B7-1 and B7-2, which are ligands for the CD28/cytolytic T lymphocyte associated antigen (CTLA)-4 counter-receptor, plays an important role in the induction of T cell-mediated antitumor immunity. We investigated the expressions of B7-1, B7-2, and human leukocyte antigen (HLA) class I in seven human hepatocellular carcinoma (HCC) cell lines by reverse transcription-polymerase chain reaction (RT-PCR) and flow cytometric analysis. RT-PCR showed that all these human HCC cell lines were positive for B7-1 and B7-2 at the messenger RNA (mRNA) level. Flow cytometric analysis revealed that they all expressed B7-1, B7-2, and HLA class I on the cell surface. However, the expression levels of B7-1 and B7-2 were very low whereas those of HLA class I were high. B7-1 and B7-2 expression could be increased by treatment with interferon alpha and interferon gamma in a dose-dependent manner, although the expression levels of B7-1 and B7-2 after interferon treatment remained low. By transfecting Hep3B cells with a plasmid containing human B7-1 complementary cDNA (cDNA), we were able to establish Hep3B cell lines strongly expressing B7-1. From mixed lymphocytes and tumor cultures analysis, the primary cytolytic activity against parental Hep3B cells could be induced effectively by B71-transfected Hep3B cells. These findings suggested that B7-1 gene transfer is the best way to induce strong expression of this molecule and this might be useful for immuno-gene therapy against human HCC.

B7/BB-1 expression and hepatitis activity in liver tissues of patients with chronic hepatitis C

Cytotoxic T lymphocytes (CTL) are closely related to the mechanism of liver injury in chronic viral hepatitis. Recently, it has been suggested that antigen-specific T cell activation requires both presentation of antigen by major histocompatibility complex (MHC) molecules and the delivery of costimulatory signals. Such signals are provided by B7/BB-1, one of the most important accessory molecules, sufficient for causing antigen-specific MHC-restricted T cell activation. To evaluate the role of B7/BB-1 in chronic hepatitis C, we immunohistochemically studied its expression in liver tissues obtained from 61 patients with hepatitis C virus (HCV) infection and compared them based on hepatitis activity. In HCV-infected liver, B7/BB-1 was strongly expressed in the cytoplasm of hepatocytes. B7/BB-1-positive cells accompanied liver-infiltrating lymphocytes and were mainly detected in the periportal region. B7/BB-1 expression was closely correlated with the activity of viral hepatitis as evaluated from scores of periportal or intralobular inflammation and necrosis, or serum alanine transferase (ALT) levels. Further study by immunostaining with anti-HCV core and anti-human leukocyte antigen (HLA) class I antibody showed B7/BB-1 positive cells near HCV core antigen- and HLA class I-positive cells, with B7/BB-1-positive cells mostly included among HLA class I-positive cells. These findings suggested that B7/BB-1 expression by hepatocytes may be induced by HCV infection and may trigger generation and activation of CTL, which may cause damage to HCV-infected HLA class I-expressing hepatocytes.

High levels of serum interleukin-10 are associated with a poor response to interferon treatment in patients with chronic hepatitis C

BACKGROUND

It still remains unclear whether some immunologic factors affect the response to interferon treatment. We therefore examined whether the pretreatment levels of serum interleukin-10 and soluble intercellular adhesion molecule-1 can be associated with the response to interferon treatment in patients with chronic hepatitis C.

METHODS

One hundred and two patients with chronic hepatitis C treated with interferon alpha-2b were divided into three groups on the basis of patterns of biochemical interferon response. Pretreatment levels of serum interleukin-10 and soluble intercellular adhesion molecule-1 were determined using enzyme-linked immunosorbent assay. Hepatitis C virus (HCV) typing was performed with a serologic enzyme-linked immunosorbent assay.

RESULTS

For patients with serotype I (n = 76) the numbers of sustained, transient, and non-responders were 12 (16%), 43 (56%), and 21 (28%), respectively. In serotype-I patients the pretreatment levels of serum interleukin-10 in non-responders were significantly higher than those in sustained or transient responders, although no significant differences were observed in HCV RNA quantity between them. There were no significant differences in the pretreatment levels of serum soluble intercellular adhesion molecule-1 among the three groups.

CONCLUSION

These findings suggest that high serum interleukin-10 levels may be related to a poor response to interferon treatment in serotype-I patients with chronic hepatitis C.

Low expression of erythrocyte complement receptor type 1 in chronic hepatitis C patients

Primate erythrocyte complement receptor type 1 (CR1) plays an essential role in complement-associated immune complex clearance by transporting complexes to macrophages in the liver and/or spleen. Antibody-bound hepatitis C virus, which consists of immune complexes, is observed in patients with chronic hepatitis C. The aim of this study was to clarify the pathophysiological roles of erythrocyte CR1 in hepatitis C virus-infected individuals. We quantified the expression of erythrocyte CR1 with a fluorescence-activated cell sorter system in 57 chronic hepatitis C and 37 chronic hepatitis B cases and 20 normal volunteers. Complement-bound immune complexes were quantified by means of an enzyme-linked immunosorbent assay using anti-C1q and anti-C3d antibodies. Hepatitis C virus-infected patients showed lower erythrocyte CR1 and higher C3d immune complex levels than volunteers (P < 0.01 and P < 0.05, respectively). An inverse correlation was observed between the erythrocyte CR1 and C3d immune complex levels in hepatitis C virus infection (r = -0.300, P = 0.032). The erythrocyte CR1 levels in hepatitis C virus infection were lower in patients with severe liver inflammation, cirrhosis, or hepatocellular carcinoma than in those with mild inflammation, whereas the levels did not differ regardless of the disease stage in hepatitis B virus infection. These findings demonstrate that the expression of erythrocyte CR1 is related to immune complex quantity and the severity of liver disease in hepatitis C virus infection.

Serial density analysis of hepatitis C virus particle populations in chronic hepatitis C patients treated with interferon-alpha

In interferon treatment of chronic hepatitis C patients, the biochemical and virological responses mostly parallel each other. However, some patients who show persistent ALT normalization display continued viremia after cessation of therapy. High-density hepatitis C virus (HCV) particles, which are immune complex forms, are reported to be less infectious both in vitro and in vivo. To assess whether high-density HCV contributes to the response discrepancies and to clarify the association with patient outcome, sera were examined from chronic hepatitis C patients who were treated with interferon-alpha. This study included 10 sustained responders with viremia (SR + ve), 5 SR without viremia, 3 transient responders (TR), and 3 nonresponders (NR). The SR + ve patients were defined as those with continued ALT normalization and serum HCV-RNA positivity at 24 weeks after therapy completion. Serum samples obtained before and 24 weeks after therapy were ultracentrifuged on 35% sucrose. The ratio between high-density and low-density HCV was determined by quantification of HCV-RNA titers in the bottom and top fractions by competitive reverse transcription and by the polymerase chain reaction, and expressed as the bottom/top (B/T) ratio. The B/T ratios before therapy were 1:1 in all groups of patients, and 1:1 after therapy in TR and NR groups. Five out of 6 SR + ve patients who showed 1:1 ratio after therapy relapsed within 1 year. In contrast, all SR + ve patients whose ratios were 10-100:1 continued to show ALT normalization. These findings demonstrate that patients who have high-density HCV dominance after therapy show persistent ALT normalization despite viremia, which can be explained by predominance of the neutralized immune complex.

Density analysis of hepatitis C virus particle population in the circulation of infected hosts: implications for virus neutralization or persistence

Hepatitis C virus has a low buoyant density in sucrose, but high-density particles are often observed in hepatitis C virus infection. To investigate the characteristics of circulating hepatitis C virus particles and their association with liver disease progression, we examined sera from two histologically normal hepatitis C virus carriers, 20 chronic hepatitis patients and five acute hepatitis C patients. The supernatants obtained after immunoprecipitation with anti-immunoglobulins antibody were subjected to sucrose equilibrium centrifugation. HCV-RNA positive fractions separated after the treatments were further examined for immunoprecipitation with anti-core hepatitis C virus antibody. We separated hepatitis C virus particle populations according to the density difference on 35% sucrose with centrifugation. The proportions of high and low density particles in hepatitis C virus populations were determined by means of competitive reverse transcription and polymerase chain reaction. Circulating hepatitis C virus particles in chronically infected patients could be separated into two populations: those immunoglobulin-bound with high densities and -unbound with low densities. Patients with severe liver inflammation had high-density hepatitis C virus that did not precipitate with anti-immunoglobulins but with anti-core hepatitis C virus antibodies. Thus, hepatitis C virus particle populations consist of low-density virions and high-density immune complexes and/or nucleocapsids. Among the chronic hepatitis patients, the dominant population shifted from low-density to high-density particles with the progression of liver disease. In acute hepatitis patients, this density shift was observed with alanine aminotransferase normalizations. Therefore, the major hepatitis C virus populations change from virion to immune complex and/or nucleocapsid with the progression of liver disease or inflammation.

Buoyant density of hepatitis C virus recovered from infected hosts: two different features in sucrose equilibrium density-gradient centrifugation related to degree of liver inflammation

Hepatitis C virus is reported to have a low buoyant density in sucrose. To determine the density of hepatitis C virus in the circulation of infected hosts and its association with the degree of liver inflammation, we examined serum samples from 10 patients who were positive for both hepatitis C virus antibody (C100 antigen) antibody and serum hepatitis C virus RNA. After the serum was ultracentrifuged in sucrose density gradient (10% to 60%), the hepatitis C virus RNA titer in each collected fraction was quantified by means of competitive reverse transcription-polymerase chain reaction. In samples from five blood donors, the hepatitis C virus RNA titer had a single peak at fractions with densities of 1.08 to 1.11 gm/ml. In samples from five patients with ALT abnormalities, the titer had two peaks at fractions with 1.09 to 1.10 gm/ml and 1.22 to 1.25 gm/ml. After the selected samples were treated with detergents and ultracentrifuged, the titer in the 1.08 to 1.11 gm/ml fractions decreased and that in the 1.22 to 1.25 gm fractions increased. This result implied that the hepatitis C virus density changed with removal of the viral envelope by lipid solvents. Thus the buoyant density of hepatitis C virus in sucrose was 1.08 to 1.11 gm/ml for an intact virion and 1.22 to 1.25 gm/ml for what was presumed to be a nucleocapsid. These results demonstrated that HCV virion is a dominant form in the circulation of blood donors without ALT abnormalities. In patients with liver inflammation HCV particles with higher densities of 1.22 to 1.25 gm/ml coexist with virion in the circulation, which might be presumed nucleocapsids.

[Local injection of high-dose CDDP to the advanced gynecological cancer]

We investigated the efficacy of local injection of high-dose CDDP. The subjects were 16 patients with advanced gynecological cancer or tumor recurrence, in whom systemic administration of CDDP was inadvisable because of advanced age or associated complications (12 cases of cervical carcinoma, 2 cases of endometrial carcinoma, 1 case of ovarian carcinoma, and 1 case of vulvar carcinoma). In 14 cases, CDDP was injected locally to the tumor mass, using a single dose of 50-300 mg. In 2 cases, a single dose of 10-20 mg of CDDP was infused into the uterine cavity. The effects of the therapy were evaluated by cytodiagnosis, tumor markers, CT, and performance status. In all cases, an antitumor effect was noted, and seven subjects survived for at least 24 months following these therapy with CDDP. One patient developed vesicovaginal and rectovaginal fistulae after local injection of CDDP following high-dose radiotherapy. We investigated the plasma concentrations of free and total platinum after CDDP application with doses from 60-200 mg/body. Plasma concentrations showed a biphasic pattern (phase alpha and phase beta), and the peak plasma concentration of CDDP was lower than that following intravenous administration of the same dose. From these results, it was suggested that a large dose of CDDP can be injected into the tumor tissue itself and the surrounding tissue with comparatively few side effects. It will be possible to administer large dose of CDDP in this way to the terminal patients to whom there is currently no other appropriate method of treatment. The performance status of our subjects was improved, and we expect that wider use of this method will improve the quality of life for end-stage patients.

[Study on management of low potential malignancy ovarian tumors]

Thirty-six patients with low potential malignancy ovarian tumors were treated at our hospital from 1972 to 1986. Of these, 80.6% were classified as stage I, 5.6% as stage II, and 13.9% as stage III. Sixteen patients were treated by simple total hysterectomy and bilateral salpingo-oophorectomy, 15 patients by unilateral salpingo-oophorectomy, 2 patients by enucleation of the tumor, and 3 patients by exploratory laparotomy. In stage I no difference between the survival rates for the conservative therapy group and the radical therapy group was seen. Postoperative radiation therapy was given to 4 patients with dysgerminoma, and chemotherapy was given to 13 other patients. The five-year survival rate for stage I was 91.7%, better than for stage I malignant ovarian tumors, which was 78.9%. But the five-year survival rate for stage II and stage III was 0%. Analysis indicated that: 1. Prognosis of stage I patients is so good that treatments may be done in consideration of the patient's fertility. 2. The importance of adequate postoperative treatment and of strict follow up to guard against recurrence of malignancy is important in patients with stage II or stage III disease.

Experimental local administration of CDDP to in vitro models of gynecological malignant tumors transplanted into nude mice (compared with medroxyprogesterone acetate orally administered)

In order to develop a new method of administration for CDDP, in vitro models of malignant tumors in the field of gynecology were prepared using two cell lines maintained by the authors, and fundamental experiments on the topical injection of CDDP were carried out. In experimental topical injection of CDDP in tumor-bearing nude mice, the test drug demonstrated an excellent tumor regression effect and an inhibitory effect on tumor growth. In the histopathologic examinations, specific necrosis of tumor cells was observed. It was confirmed that this is a highly safe method, as tissue separation, ulceration, or hemorrhagic lesions attributable to the local administration of CDDP were not observed. In the present study, treatment with oral medroxyprogesterone acetate was also used. At the doses used in this study, however, no inhibitory effect on tumor growth or synergism between medroxyprogesterone acetate and CDDP was observed. Topical injection is an excellent pharmacodynamic method that permits the injection of free platin into the tumor itself or in the boundary area between the tumor and normal tissues, with no loss of the drug, and it is considered a safe and effective mode of local administration. Intra-arterial injection of this drug alone or in conjunction with OK-432 can also be used, even though further studies will be required to determine the optimum dosage and reduce side effects. At present, data are being collected on terminal cancer patients for whom no other therapy is available. In the near future this method of administration is expected to be utilized in the clinical treatment of malignant tumors, be it early tumor or progressive cancer.