Depth dose measurements in water for 11C and 10C beams with therapy relevant energies.

Owing to the favorable depth-dose distribution and the radiobiological properties of heavy ion radiation, ion beam therapy shows an improved success/toxicity ratio compared to conventional radiotherapy. The sharp dose gradients and very high doses in the Bragg peak region, which represent the larger physical advantage of ion beam therapy, make it also extremely sensitive to range uncertainties. The use of ß +-radioactive ion beams would be ideal for simultaneous treatment and accurate online range monitoring through PET imaging. Since all the unfragmented primary ions are potentially contributing to the PET signal, these beams offer an improved image quality while preserving the physical and radiobiological advantages of the stable counterparts. The challenging production of radioactive ion beams and the difficulties in reaching high intensities, have discouraged their clinical application. In this context, the project Biomedical Applications of Radioactive ion Beams (BARB) started at GSI (Helmholtzzentrum für Schwerionenforschung GmbH) with the main goal to assess the technical feasibility and investigate possible advantages of radioactive ion beams on the pre-clinical level. During the first experimental campaign 11C and 10C beams were produced and isotopically separated with the FRagment Separator (FRS) at GSI. The ß +-radioactive ion beams were produced with a beam purity of 99% for all the beam investigated (except one case where it was 94%) and intensities potentially sufficient to treat a small animal tumors within few minutes of irradiation time, ∼ 106 particle per spill for the 10C and ∼ 107 particle per spill for the 11C beam, respectively. The impact of different ion optical parameters on the depth dose distribution was studied with a precision water column system. In this work, the measured depth dose distributions are presented together with results from Monte Carlo simulations using the FLUKA software.

Radioactive Beams for Image-Guided Particle Therapy: The BARB Experiment at GSI.

Several techniques are under development for image-guidance in particle therapy. Positron (ß+) emission tomography (PET) is in use since many years, because accelerated ions generate positron-emitting isotopes by nuclear fragmentation in the human body. In heavy ion therapy, a major part of the PET signals is produced by ß+-emitters generated via projectile fragmentation. A much higher intensity for the PET signal can be obtained using ß+-radioactive beams directly for treatment. This idea has always been hampered by the low intensity of the secondary beams, produced by fragmentation of the primary, stable beams. With the intensity upgrade of the SIS-18 synchrotron and the isotopic separation with the fragment separator FRS in the FAIR-phase-0 in Darmstadt, it is now possible to reach radioactive ion beams with sufficient intensity to treat a tumor in small animals. This was the motivation of the BARB (Biomedical Applications of Radioactive ion Beams) experiment that is ongoing at GSI in Darmstadt. This paper will present the plans and instruments developed by the BARB collaboration for testing the use of radioactive beams in cancer therapy.

Synthetic peptide-based electrochemiluminescence immunoassay for anti-Borna disease virus p40 and p24 antibodies in rat and horse serum.

Borna disease virus (BDV) is a neurotropic pathogen that infects a wide variety of vertebrates. We have developed a new electrochemiluminescence immunoassay (ECLIA) for the detection of antibodies to BDV, using three synthetic peptides corresponding to the amino acid residues 3-20 and 338-358 of p40 and 59-79 of p24 peptide of BDV. Using the ECLIA, we examined serum samples for the presence of anti-BDV antibodies in 20 rats (experimentally BDV-infected and uninfected) and 38 horses (13 US horses, experimentally infected and uninfected, and 25 Japanese horses, feral and domestic). The ECLIA, performed in a double-blind manner, detected anti-BDV antibodies in rats with a history of BDV infection, giving results that were in agreement with indirect immunofluorescence assay and/or Western blot (WB) analysis. The ECLIA also correctly identified all three experimentally infected horses and four domestic American horses that were seropositive for BDV antibodies by WB. Among the Japanese horses, at least two out of 10 feral and six out of 15 domestic horses were seropositive for BDV. In most of these cases, the specificity of immunoreactivity was verified by blocking with soluble p40 and p24 peptides.

Efficacy of a mixed glycoprotein vaccine against pseudorabies in pregnant sows.

A pseudorabies virus (PRV) glycoprotein-mixed vaccine was prepared by heparin-affinity chromatography from PRV-infected PK-15 cell lysates. In our previous study, the trial vaccine was induced protection with suppression of virus shedding in one-month-old pigs and generation of cytotoxic T lymphocyte (CTL) response in mice. In this study, the effect of the trial vaccine on suppression of both virus shedding and reproductive failure in pregnant sows was examined. Three sows were vaccinated twice until one week before mating. Each of them was infected intranasally with 10(6) TCID50 of PRV on day 28, 54, or 85 after mating, respectively. Three other sows were also mated and challenged at the same time as the respective control. The vaccinated sows produced virus-neutralizing antibodies. Sows with high level of VN antibody lowered the level and period of virus shedding after challenge. The maximum level of shed-virus titers in vaccinated sows were 10(1.25) to 10(3) times lower than controls. Vaccinated sows shed virus for 1 or 5 days, while controls shed for 8, 9, or 12 days. No abortion or stillbirth was observed in vaccinated sows during pregnancy. On the other hand, control sow challenged at a late stage of pregnancy showed abortion and stillbirth. The results obtained here indicate that our trial vaccine is effective to prevent reproductive failure by pseudorabies virus.

Protective effect of glycoprotein gC-rich antigen against pseudorabies virus.

A trial vaccine containing pseudorabies virus (PRV) glycoprotein gC as the main component showed excellent protection against virulent virus infection in pigs. Glycoprotein gC-rich antigen was prepared by heparin affinity chromatography from PRV-infected cell lysates. The preparations were mixed with mineral oil adjuvant as a water-in-oil emulsion. Six-week-old pigs were immunized twice at two-week intervals with trial vaccines containing 128,000, 12,800 and 1,280 HA units per dose of gC antigen. They were then challenged with a virulent PRV at day 7 after the final immunization. Neutralizing (NT) antibodies were produced with increase of antibody titers after challenge. Pigs immunized with 128,000 HA units per dose of gC survived and showed no virus shedding during the 2-week experimental period after the challenge. The role of cell-mediated immunity was examined using BALB/c mice, and induction of gC-specific cytotoxic T lymphocytes (CTLs) was detected by 51Cr release assay. From these results with mice, it is inferred that cell-mediated immunity, especially CTL, may play an important role in the effectiveness of our trial vaccine in addition to humoral immunity.

Influences of The Great Hanshin-Awaji Earthquake on glycemic control in diabetic patients.

We investigated influences on glycemic control in 177 diabetic patients after The Great Hanshin-Awaji Earthquake which occurred on January 17, 1995. Changes in serum HbA(1c) level were studied according to the worsen rate of dietary and living conditions. A significant temporary increase in the mean value of HbA(1c) level was found after the earthquake (8.34 +/- 2.07% in March, 1995 vs. 7.74 +/- 1.82% in December, 1994, P < 0.01). Ninety nine of them showed more than 0.5% in the rate of increase. Multiple regression analysis was applied to the following factors: inappropriate diet, discontinuation of drug uptake, reduction of exercise, destruction of house, long stay at shelter, sex, age, and pre-earthquake therapy. Among them, inappropriate diet demonstrated the highest partial regression coefficient to raise the mean value of the HbA(1c) level. The increased level of HbA(1c) declined gradually to the pre-earthquake level in September, 1995. This study emphasizes the importance of appropriate diet for diabetic patients during a natural disaster. To fulfil it, medical staff have to educate diabetic patients of their disorders tediously in ordinary time. In addition, it seems quite useful to supply a medical information card and a small medical bag containing essential drugs to each patient.

[Clinical usefulness of polyamino acid particle agglutination test for detection of anti-HTLV-I antibody].

A new artificial carrier particle agglutination test using polyamino acid (polyamino PA) was developed for anti HTLV-I assay. We carried out the comparative study on anti-HTLV-I among polyamino PA, gelatin PA, EIA and WB methods. All of 76 ATL, 20 HAM/TSP, 53 patients with uveitis and 50 HTLV-I carriers were seropositive and 50 HTLV-I non carriers were seronegative with four methods. Eighteen of 503 patients include autoimmune diseases showed seropositive by polyamino PA and gelatin PA. One of 19 seropositives by EIA was false positive. All of 25 sera showed non-specific reaction by the gelatin PA were clearly negative by the polyamino PA. This is due to the fact that the polyamino acid particle has a greater specific gravity as carrier. The final judgement was got within 45 minutes. It was earlier more 30 minutes than the gelatin PA. The polyamino PA is a simple, rapid, sensitive and specific method. Therefore, it is useful for mass screening and clinical diagnosis.

Experimental toxoplasmosis in pregnant cats.

Cysts of the K strain of Toxoplasma gondii were administered orally to nine pregnant cats having no antibody to the organism at each of the three stages of gestation, namely early (14 days), middle (30 days), and late (40 and 51 days). Premature and weak or deformed fetuses were observed in the offsprings delivered by mother cats infected with Toxoplasma in the early or middle stage of gestation, while the cats infected at the late stage were delivered of apparently healthy fetuses. Mother cats developed parasitemia excreting Toxoplasma oocysts in their feces and formed the antibody to the organism after the oral administration. Toxoplasma was recovered from the organs or tissues of all fetuses delivered by the mother cats infected in the early stage of gestation. All kittens born healthy from the cats infected in the middle stage of gestation were free from Toxoplasma, but 80% of the premature kittens were found to be infected. Toxoplasma was isolated also from the organs of about half the offsprings born healthy from the mother cats infected in the late stage of gestation. These results indicate that congenital infection with Toxoplasma may occur commonly and cause damage to the fetuses when pregnant cats are infected orally with Toxoplasma cysts in the early or middle stage of gestation.

The study of HCV antibody and serologic tests for syphilis in Thai patients with gynecologic disorders.

Investigation for prevalence of antibodies to hepatitis C virus (HCV) and to Treponema pallidum was conducted in 883 females with gynecologic disorders who were admitted to the gynecological ward of the Department of Obstetrics and Gynecology, Siriraj Hospital during April to August 1991. The study population consisted of 678 patients with malignancies and 205 patients with benign diseases. Anti-HCV antibody was found in 3.1% of the cases with malignancies and 1.46% of those with benign diseases. Among the gynecologic malignant group, the patients with carcinoma of cervix had the highest prevalence of HCV antibody (3.6%). The positive serologic tests for syphilis in patients with carcinoma of cervix (9.8%) were significantly higher from those in patients with ovarian carcinoma (3.75%) (p < 0.01). There were 3 cases with carcinoma of cervix who were simultaneously sero-positive for both HCV and syphilis.

Physicochemical properties of pseudorabies virus hemagglutinin.

Pseudorabies virus hemagglutinin was readily adsorbed on mouse erythrocytes at 4, 22, or 37 degrees C, but not on cattle erythrocytes. The adsorbed hemagglutinin could not be eluted from the cells by resuspending in phosphate-buffered saline (PBS), by incubating at 37 or 50 degrees C, or by incubating in the presence of neuraminidase. The receptor on mouse erythrocytes for the hemagglutinin was inactivated by trypsin, but not by neuraminidase, sodium deoxycholate (DOC), potassium periodate (KIO4), dithiothreitol (DTT), 2-mercaptoethanol (2-ME) and formalin. The hemagglutinin was inactivated by trypsin, alpha-amylase, pepsin, DOC, KIO4, and ethylendiamine-tetraacetic acid (EDTA), but not by papain, beta-glucosidase, phospholipase C, neuraminidase, DTT, 2-ME, Tween-80, ethylether, chloroform, trichloro-trifluoroethane, beta-propiolactone and formalin, suggesting that the hemagglutinin active component involved glycoproteins. The hemagglutinin was stable at 37 degrees C for lower temperatures but not at 60 degrees C or higher. The hemagglutinin activity was resistant to ultraviolet irradiation, while the infectivity was very susceptible. The hemagglutinin and the infectivity were readily sedimented by ultracentrifugation at 48,000 x g for 3 hr. In rate zonal centrifugation of the preparation on a sucrose density gradient, the hemagglutination (HA) activity showed a sharp peak at 1.22 g/ml coinciding with the peak of infectivity. The HA activity in the peak fraction seemed to be structually associated with virus particles. After fractionation of the virus by Nonidet P-40, the HA activity was found only in the fraction of the envelope material, indicating that the hemagglutinin is situated in the viral envelop.

[Seropositivity of anti-HTLV-II antibodies in patients with HTLV-I-associated myelopathy and adult T-cell leukemia].

Dr Kira et al. (Lancet 1991, 338: 64-65) stress the high incidence of the co-infection with HTLV-I and HTLV-II in the HTLV-I associated myelopathy or tropical spastic paraparesis (HAM/TSP) detected by a polymerase chain reaction (PCR). They showed that 67% of HAM/TSP patients and 6% of healthy carriers had the co-infection. They suggested the co-infection might be important for the development of the myelopathy. Recently, we have analyzed the seropositivity of antibodies to HTLV-I and II in Adult T-cell Leukemia (ATL), HAM/TSP and carriers in Japan using SELECT-HTLV (IAF Biochem International Inc., Montreal, Canada). This system was a solid phase enzyme immunoassay utilizing synthetic peptides to differentiate between antibodies to type I and II. We examined 101 samples (31 ATL patients, 20 HAM/TSP and 50 carriers) which were all positive with the particle agglutination (PA, Fujirebio, Tokyo) and ELISA (Eisai, Tokyo). All samples were negative with HTLV-II and positive with HTLV-I. The results of our serological survey suggested that HTLV-II did not associate with the etiology of ATL and HAM/TSP in Japan.

Appearance of slow-reacting, complement-requiring hemagglutination-inhibiting antibody in swine infected with pseudorabies virus.

Slow-reacting, complement-requiring hemagglutination-inhibiting (HI) antibody was detected in sera from pigs infected with pseudorabies virus; approximately 16 hemolytic units of complement were necessary for the detection of such antibody. Higher HI antibody titers were obtained when antigen and serum were allowed to incubate before addition of complement than when all three components were incubated at the same time. A HI test was developed in which antigen-serum mixtures were incubated at 4 degrees C for 48 h and then with complement at 37 degrees C for 1 h; this gave an improved sensitivity over the previous incubation without complement.