Relative biological effectiveness of the 235 MeV proton beams at the National Cancer Center Hospital East

A therapy-dedicated cyclotron was installed in the National Cancer Center Hospital East (NCCHE) at Kashiwa in 1997. Prior to the start of clinical use, we investigated the biological effectiveness of therapeutic proton beams for cell lethality. The proton beams accelerated up to 235 MeV were horizontally extracted from the cyclotron, and scattered by a bar-ridge filter to produce a Spread-Out-Bragg-Peak (SOBP) of 10-cm width. The biological systems used here were mouse intestinal crypt cells and three in vitro cell lines, including SCC61 human squamous cell carcinoma, NB1RGB human fibroblasts and V79 Chinese hamster cells. The dose responses after irradiation at either the entrance plateau or the middle portion of SOBP were compared with those after linac 6 MV X-ray irradiation. The fit of a linear quadratic model to survival curves showed that proton irradiation increased the alpha value of SCC61 and the beta value of V79 cells with a least change for alpha/beta ratio of NB1RGB cells. The isoeffect dose that reduces either cell survivals to 10% or mouse jejunum crypts to 10 per circumference was termed D10. The relative biological effectiveness (RBE) of protons obtained by comparing the D10 values between protons and X-rays ranged from 0.9 to 1.2. The depth distribution of cell lethality was measured by replating V79 cells after irradiation from a "cell stack chamber" that received a single dose of 7 Gy at the middle position of SOBP. The thus-obtained cell survivals at various depths coincided well with the estimated survivals, but tended to decrease at the distal end of SOBP. We conclude that an RBE of 1.1 would be appropriate for 235 MeV proton beams at the NCCHE.     

Cause-specific mortality risk among male alcoholics residing in the Osaka metropolitan area

We evaluated the mortality risk among 306 male alcoholics living in Osaka, Japan, at the time of initial diagnosis between 1972 and 1983, with regard to the cause of death, length of time from diagnosis, and participation in an alcohol abstinence self-help group. By the closing date on 1 March 1992, 110 of the 306 alcoholics had died, yielding an observed-to-expected (O/E) ratio of 4.5 [95% confidence interval (CI) = 3.7-5.4]. The alcoholics had significantly elevated mortality risks from all malignant neoplasms (O/E = 2.1, 95%CI = 1.2-3.3), esophageal cancer (O/E = 8.4, 95%CI = 1.7-24.5), diseases of the circulatory system (O/E = 4.4, 95%CI = 3.0-6.2), liver cirrhosis (O/E = 15.9, 95%CI = 10.2-23.6), diseases of the genitourinary system (O/E = 6.3, 95%CI = 1.3-18.5), and external death (O/E = 10.3, 95%CI = 6.3-15.8). The mortality risk from all causes still remained significantly high beyond the tenth year following initial diagnosis (O/E = 2.6, 95%CI = 1.0-6.2). The mortality risks from liver cirrhosis and external death (such as suicide) were highest within the first year following diagnosis, and were still high beyond the tenth year. A significantly high mortality risk from diseases of the circulatory system was observed between the first and ninth years, and the mortality risk from all malignant neoplasms was significantly elevated beyond 10 years following diagnosis. Alcoholics who did not join a self-help group soon after the initial institutional treatment had different cause-specific and time-specific mortality risks from those who did join a self-help group. These findings show the importance of long-term clinical follow-up of male alcoholics, taking into consideration the cause-specific mortality.     

Effect of paclitaxel on cisplatin resistant head and neck squamous multicellular tumor spheroids

Paclitaxel has been reported to be effective for the treatment of CDDP resistant tumors. Thus, the efficacy of paclitaxel on CDDP resistant HEp-2 and KB head and neck squamous carcinoma cell lines was evaluated in monolayer and multicellular tumor spheroids (MTS). Cell lines with a tenfold resistance to CDDP were used in this study (Tanaka, K. et al, Keio J Med, 70. 1993). MTS were developed using the liquid overlay culture technique. After exposure to graded concentrations of drugs and different exposure time, the cells were subjected to a clonogenic assay. The effect of paclitaxel on both monolayer and MTS was dependent on the drug concentration and related to the exposure time. For HEp-2 MTS, 10(-7) M/L of paclitaxel resulted in a cell death rate of approximately 90% in both parent and resistant cells. For KB MTS, the cells were more resistant to paclitaxel than the HEp-2 cells, and a 72 hour exposure time was needed to achieve a cell death rate of approximately 90%. These data suggest that paclitaxel may be effective for treating CDDP resistant head and neck cancer.     

Time-dependent promotion activity of 17beta-estradiol on uterine carcinogenesis in mice initiated with N-ethyl-N-nitrosourea

The time-dependent promotion activity of 17beta-estradiol (E2) by initiation with N-ethyl-N-nitrosourea (ENU) on induction of mouse uterine endometrial proliferative lesions was examined. Illumination-induced persistent estrous female CD-1 mice were divided into five groups at 9 weeks of age. At 10 weeks of age, mice in all groups (n=25) were given a single intra-uterine administration of ENU (50 mg/kg), dissolved in polyethylene glycol. Animals in Groups 2 to 5 were then implanted s.c. with an E2 pellet at 9, 11, 14 and 17 weeks of age. The implants were left in place for 8 weeks and then taken out. At the termination of the experiment (week 15 after the ENU-treatment), all surviving mice were killed and the development of uterine proliferative lesions were assessed. All groups demonstrated endometrial hyperplasias and adenocarcinomas and the incidences of the latter in ENU plus E2 treated animals (Groups 2 to 5; 36, 48, 35 and 36%, respectively) were significantly higher compared to 8% for Group 1, without any variation with the age at E2 treatment. However, the incidences of adenocarcinomas plus severe hyperplasias increased from Groups 1 to 5 (28, 40, 56; P<0.05, 61; P<0.05 and 80%; P<0.01, respectively), indicating that promotion effects of E2 on induction of uterine proliferative lesions in the uterine endometrium become more pronounced with the interval after ENU initiation.     

Prognostic factors for short-term survival in patients with stage IV non-small cell lung cancer.

Prognostic factors which can forecast short-term survival in patients with stage IV non-small cell lung cancer have not been well evaluated. Characteristics of such factors may be different from those for overall survival, and would be an important eligibility criterion for clinical trials of chemotherapy. We retrospectively analyzed the data of 158 patients with stage IV non-small cell lung cancer whose performance status was 0, 1 or 2. Univariate and multivariate logistic regression models revealed demographic variables which significantly correlated with the survival at 8 or 12 weeks. The univariate model showed the following significant variables: T factor, N factor, number of organs with metastases, grade of performance status, weight loss within 6 months, evidence of metastasis either at bone or lymph node, and lactate dehydrogenase level. The subsequent multivariate model demonstrated that both grade of performance status under 2 and number of metastasized organs less than 3 are important factors for 8- or 12-week survival. The survival rate in patients meeting the two criteria (grade of performance status under 2 and number of metastasized organs less than 3) and in those meeting only one of them was 93% versus 80% at 8 weeks (P = 0.030) and 88% versus 62% at 12 weeks (P < 0.001), respectively. Grade of performance status and number of organs with metastases appear to be important prognostic factors for short-term survival in patients with stage IV non-small cell lung cancer.     

Susceptibilities of bacteria isolated from patients with lower respiratory infectious diseases to antibiotics (1997)]

The bacteria isolated from the patients with lower respiratory tract infections were collected by institutions located throughout Japan, since 1981. Ikemoto et al. have been investigating susceptibilities of these isolates to various antibacterial agents and antibiotics, and analyzed some characteristics of the patients and isolates from them each year. Results obtained from these investigations are discussed. In these 17 institutions around the entire Japan, 512 strains of presumably etiological bacteria were isolated mainly from the sputa of 440 patients with lower respiratory tract infections during the period from October in 1997 to September in 1998. MICs of various antibacterial agents and antibiotics were determined against 100 strains of Staphylococcus aureus, 81 strains of Streptococcus pneumoniae, 85 strains of Haemophilus influenzae. 71 strains of Pseudomonas aeruginosa (non-mucoid strains), 27 strains of Pseudomonas aeruginosa (mucoid strains), 33 strains of Moraxella subgenus Branhamella catarrhalis, 17 strains of Klebsiella pneumoniae etc., and the susceptibilities of these strains were assessed except for those strains that died during transportation. S. aureus strains for which MICs of oxacillin (MPIPC) were higher than 4 micrograms/ml (methicillin-resistant S. aureus: MRSA) accounted for 55.0%. The frequency of the drug resistant bacteria decreased comparing to the previous year's 67.3%. Arbekacin (ABK) and vancomycin (VCM) showed the most potent activities against MRSA. Imipenem (IPM) and panipenem (PAPM) of carbapenems showed the most potent activities with MIC80S of 0.063 microgram/ml against S. pneumoniae. The frequency of penicillin (PC)-intermediate S. pneumoniae (PISP)+PC-resistant S. pneumoniae (PRSP) had decreased gradually, that is, in 1995 the frequency of it was 40.3%, but that was 30.9% in 1997. Against H. influenzae and M.(B.) catarrhalis, all the drugs showed good activities. But the sensitive strains of them against ceftazidime (CAZ) had decreased in 1997, compared those in 1995 and 1996. Meropenem (MEPM), IPM and tobramycin (TOB) showed the most potent activity against P. aeruginosa (mucoid strains). And TOB and ciprofloxacin (CPFX) showed the most potent activities against P. aeruginosa (non-mucoid strains). All drugs except ampicillin (ABPC) were more active against K. pneumoniae in 1997 than that in 1996. Also, we investigated year to year changes in the characteristics of patients, their respiratory infectious diseases, and the etiology. The examination of age distribution indicated that the proportion of patients with ages over 70 years was 45.5% of all the patients showing a slight increase year by year. About the proportion of diagnosed diseases, not so particular changes were recognized as follows: Bacterial pneumonia and chronic bronchitis were the most frequent with 33.6% and 29.1%, respectively. Number of strains isolated from patients before administration of antibiotics were more than those after administration of them in chronic bronchitis, but these had reversed in bacterial pneumonia. The tendency in bacterial pneumonia had been acknowledged since 1995. The increase of S. aureus and P. aeruginosa (both mucoid and non-mucoid strains) isolated after administration of antibiotics, has suggested the decrease of the susceptibility of these strains against antibiotics. Administration of antibiotics has changed the results of the frequency of isolation of bacterial species. Bacterial isolations before administration of antibiotics were as follows: S. pneumoniae 24.5%, H. influenzae 21.4%, S. aureus 18.4% and P. aeruginosa 12.2%. The frequencies of S. aureus decreased after antibiotics administration over 15 days, but the frequencies of P. aeruginosa was not affected. The frequencies of P. aeruginosa was 47.8% after administration over 15 days. From patients administered antibiotics of penicillins and cephems. S. aureus was mainly detected with 31.7-58.3%, and from patients administere     

Mechanism of decrease in levels of hepatic P450 isozymes induced by intracerebral endotoxin: independence from sympathetic nervous and adrenocortical systems

We previously reported that lipopolysaccharide (LPS) injected intracerebroventricularly (i.c.v.) at an ineffective dose (0.1 μg/rat) decreased the drug metabolizing activities and related cytochrome P450 (CYP) isozymes in rat liver microsomes when injected intraperitoneally (i.p.). The dose study (doses <0.1 μg intracerebrally and >0.1 μg i.p.), which was carried out to examine how much more effective is i.c.v.-LPS than i.p.-LPS, showed that the pattern of alteration of expression of CYP isozymes induced by i.c.v.-LPS was different from that caused by i.p.-LPS at an effective dose (10 μg/rat). These results indicate that the decrease in hepatic CYP isozymes caused by i.c.v.-LPS could not be explained by the LPS leaked from the brain, suggesting that the decrease in hepatic CYP isozymes by i.c.v.-LPS may be caused by a central action of LPS. In this study, the possible involvement of sympathetic nervous and adrenocortical systems in the down-regulation of CYP isozymes by i.c.v.-LPS was investigated using surgical or chemical sympathetecomized or adrenalectomized rats. The norepinephrine (NE) content in the liver in rats with surgical hepatic sympathetectomy was reduced by 88% compared with that of sham-operated rats that received i.c.v.-saline and 85% compared with that of sham-operated rats that received i.c.v.-LPS, indicating that hepatic denervation was successful. The NE content in the liver in rats chemically sympathetectomized by two i.p. injections of 6-hydroxydopamine (40 mg/kg each time) 1 and 2 days before i.c.v. injection was reduced by 82% in i.c.v.-saline-treated and by 74% in i.c.v.-LPS-treated groups compared with that in rats pretreated with i.p.-saline. These results indicate that sympathetic NE terminals were effectively removed. Intracerebroventricular LPS decreased the total P450 content and the activities of CYP dependent drug metabolizing enzymes, ethoxyresorufin O-deethylase (EROD), pentoxyresorufin O-depentylase (PROD), imipramine N-demethylase (IMND) and erythromycin N-demethylase (ERND) after 24 h in both sympathetectomized rats and non-denervated rats. Adrenalectomy (ADX) reduced the level of corticosterone in serum by 81% compared to sham-operated rats, indicating that adrenalectomy was successful. ADX did not inhibit the decrease in the total P450 content and the metabolism of drugs induced by i.c.v.-LPS, but more profoundly emphasized the inhibitory effect of i.c.v.-LPS than the sham-operation. These results suggest that the sympathetic nervous systems both directly and indirectly innervating the liver do not participate in the primary mechanism of the decrease in the activities of CYP isozymes in rat liver microsomes induced by i.c.v.-LPS. Also, the adrenal glands, especially the adrenocortical system, play a suppressive role in the decrease in CYP isozymes caused by i.c.v.-LPS. Received: 31 August 1998 / Accepted: 24 November 1998     

Therapy-related leukemia and myelodysplastic syndrome in breast cancer patients treated with cyclophosphamide or anthracyclines

BACKGROUND: Accumulation of data regarding therapy-related leukemia (TRL) or myelodysplastic syndrome (t-MDS) is critical for assessing the risk of developing such diseases and for subsequent decision-making processes for better treatment. METHODS: We evaluated the clinical characteristics of patients with TRL/t-MDS diagnosed at the National Cancer Center Hospital between January 1989 and September 1997. This report is concerned with those patients who initially had been treated with chemotherapeutic agents for breast cancer. RESULTS: Thirteen patients (median age, 55 years) developed TRL (n = 4) or t-MDS (n = 9). The median interval between the development of TRL/t-MDS and initial treatment was 94 months (range 23-190 months). For the primary therapy, all patients had received intense and prolonged treatment with cyclophosphamide (CPA) and/or anthracyclines including doxorubicin (DOX), with a median cumulative dose of 55 g/body (range 16.4-288.5 g) for CPA and 480 mg/m2 (range 395-625.5 mg/m2) for DOX. Seven patients were subsequently treated by chemotherapy and one received an allogeneic bone marrow transplantation. CONCLUSIONS: Clinicians must remain alert to the risks associated with unproven medical practices which include long-term administration of alkylating agents. Selected patients with TRL/t-MDS may respond to intense salvage combination chemotherapy.     

Induction of immunity to prostate cancer antigens: results of a clinical trial of vaccination with irradiated autologous prostate tumor cells engineered to secrete granulocyte-macrophage colony-stimulating factor using ex vivo gene transfer.

Vaccination with irradiated granulocyte-macrophage colony-stimulating factor (GM-CSF)-secreting gene-transduced cancer vaccines induces tumoricidal immune responses. In a Phase I human gene therapy trial, eight immunocompetent prostate cancer (PCA) patients were treated with autologous, GM-CSF-secreting, irradiated tumor vaccines prepared from ex vivo retroviral transduction of surgically harvested cells. Expansion of primary cultures of autologous vaccine cells was successful to meet trial specifications in 8 of 11 cases (73%); the yields of the primary culture cell limited the number of courses of vaccination. Side effects were pruritis, erythema, and swelling at vaccination sites. Vaccine site biopsies manifested infiltrates of dendritic cells and macrophages among prostate tumor vaccine cells. Vaccination activated new T-cell and B-cell immune responses against PCA antigens. T-cell responses, evaluated by assessing delayed-type hypersensitivity (DTH) reactions against untransduced autologous tumor cells, were evident in two of eight patients before vaccination and in seven of eight patients after treatment. Reactive DTH site biopsies manifested infiltrates of effector cells consisting of CD45RO+ T-cells, and degranulating eosinophils consistent with activation of both Th1 and Th2 T-cell responses. A distinctive eosinophilic vasculitis was evident near autologous tumor cells at vaccine sites, and at DTH sites. B-cell responses were also induced. Sera from three of eight vaccinated men contained new antibodies recognizing polypeptides of 26, 31, and 150 kDa in protein extracts from prostate cells. The 150-kDa polypeptide was expressed by LNCaP and PC-3 PCA cells, as well as by normal prostate epithelial cells, but not by prostate stromal cells. No antibodies against prostate-specific antigen were detected. These data suggest that both T-cell and B-cell immune responses to human PCA can be generated by treatment with irradiated, GM-CSF gene-transduced PCA vaccines.     

Structures of ADP-ribosylated rifampicin and its metabolite: intermediates of rifampicin-ribosylation by Mycobacterium smegmatis DSM43756

23-(O-ADP-Ribosyl)rifampicin [RIP-TAs (3, Na+ form), RIP-TAf (4, H+ form)] was obtained as an intermediate in the conversion process of rifampicin (1) to RIP-Mb (2) that is mediated by cell homogenates of Mycobacterium smegmatis DSM43756 or of Escherichia coli carrying a mycobacterial mono(ADP-ribosyl) transferase gene, in the presence of NADH. 23-[O-(5'-Phosphoribosyl)]rifampicin (5, RIP-TAp) was also obtained by the reaction of rifampicin with NADH in the presence of a homogenate of M. smegmatis. The structures of 3, 4, and 5 were determined by means of MS and NMR analyses.