Ridge filter design for proton therapy at Hyogo Ion Beam Medical Center

At the Hyogo Ion Beam Medical Center (HIBMC) we have developed a new design method for the bar ridge filter used in proton therapy, taking into consideration the scattering and nuclear interaction effects within the filter itself, which are introduced in the design. In our beam delivery system, the bar ridge filter is employed as the range modulator. It is combined with the wobbler system, and produces a three-dimensionally uniform spread-out Bragg peak (SOBP). The design program predicts the three-dimensional dose distribution. Ridge filters of 3-12 cm SOBP in 1 cm increments were designed in the maximum radiation field for 150 MeV and 190 MeV proton beams so that a uniform physical dose area is obtained in the SOBP region three-dimensionally. Measurements were performed with the constructed ridge filters to verify the uniformity and these were compared with the predictions of the design program. The predictions and measurements were found to be in agreement except for the 12 cm SOBP. The uniformities were better than +/- 3.0% for all SOBPs produced. The ridge filters are now clinically in use.     

Synthetic peptides as antigens for the detection of humoral immunity to Plasmodium falciparum sporozoites

The presence of antibodies against P. falciparum sporozoites in humans living in malaria-endemic areas was measured using as antigen the synthetic peptide (NANP)3, which represents the immunodominant region of the circumsporozoite (CS) protein. By using a competitive binding assay it was determined that antibodies which recognize (NANP)3 do not react with a 22-Mer synthetic peptide representing a cross-reacting epitope present in an antigen (5.1) from the blood stages of the parasite. Antibodies present in human sera which react with the 5.1 peptide did not react with (NANP)3. This strongly suggests that antibodies to (NANP)3 found in sera of individuals living in endemic areas are a reflection of exposure to P. falciparum sporozoites. These results validate the use of (NANP)3 for epidemiological studies to detect and measure humoral immunity to P. falciparum sporozoites.     

Kupffer cell-mediated cytotoxicity against hepatoma cells occurs through production of nitric oxide and adhesion via ICAM-1/CD18

Rat Kupffer cell (KC)-mediated cytotoxicity against both thesyngeneic hepatoma cell line AH70 and hepatocytes was evaluatedby changes in mitochondrial function, and the possible roleof ICAM-1/CD18 in the interaction between the cells was studied.Rhodamine 123 fluorescence, a marker of the mitochondrial membranepotential, decreased in AH70 cells after co-culture with KC,while that in hepatocytes was unchanged by co-culture. Thisdecrease was blocked by anti-ICAM-1, anti-CD18 and the Inhibitionof nitric oxide synthesis. Cytometric studies demonstrated thatICAM-1 expression on AH70 cells increased after addition ofIFN-, IL-1ß, tumor necrosis factor (TNF)- or KC, whilein hepatocytes ICAM-1 was not increased. Anti-ICAM-1 pretreatmentinhibited the increase in ICAM-1 expression and the decreasein rhodamine 123 fluorescence on AH70 cells after co-culturewith KC. CD18 on KC was increased only after co-culture withAH70. TNF- but not IFN- was detected in the supernatant of co-culturebetween KC and AH70 cells, and this production was partiallyinhibited by anti-ICAM-1 and anti-CD18. The activity of Induciblenitric oxide synthase in Kupffer cells and the levels of nitritesand nitrates in the co-culture supernatant increased over time,and this increase was attenuated either by addition of NO synthesisinhibitors, anti-ICAM-1 or anti-CD18. These results indicatethat the rat KC causes mitochondrial dysfunction in cancer cellsvia the production of NO and cell-to-cell adhesion via ICAM-1/CD18has an Important role in this cytotoxic process.     

De novo interstitial deletion of 4q[46,XX,del(4)(q27q28.2)] with intact blood group-MN locus,confining its locus to 4q28.2–4q31.1

We report a malformed female infant withde novo interstitial deletion of 4q[46,XX,del(4)(q27q28.2)]. The MN blood type analysis of the family members showed that the patient had an intact blood group-MN locus. The locus of the gene responsible for the MN antigen activity is confined to a 4q28.2–4q31.1 segment on the basis of the result of this patient and the previous mapping data.     

Acute toxicity, inductive effects of liver enzymes and distribution in the liver of 1,2,3,7,8-pentachlorodibenzo-p-dioxin in rats

Acute toxicity, inductive effects of liver enzymes and liver persistency of 1,2,3,7,8-pentachlorodibenzo-p-dioxin (PenCDD) were compared with those of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) using male Wistar rats. 1,2,3,7,8-PenCDD treatment at a dose of 0.1 mumol/kg resulted in significant depression of growth of rats from a day to 28 days after treatment. However, the effect was relatively less than that of 2,3,7,8-TCDD. On 5 days, similarly to 2,3,7,8-TCDD-treated group, liver hypertrophy and thymic atrophy were observed in 1,2,3,7,8-PenCDD-treated groups. In addition, 1,2,3,7,8-PenCDD showed potent 3-methylcholanthrene-type inducing ability. For example, the activities of benzo(a)pyrene 3-hydroxylase and DT-diaphorase were 25-fold and 10-fold of control, respectively. On 30 days, about 50% of the inductive effects on 5 days were maintained in both 1,2,3,7,8-PenCDD- and 2,3,7,8-TCDD-treated groups. Amount of 1,2,3,7,8-PenCDD distributed to the liver on 5 days was about 80-90% of dose and was about 1.5 times greater than that of 2,3,7,8-TCDD. About 50% of dose of 1,2,3,7,8-PenCDD remained even on 30 days after treatment. From these results, it is suggested that 1,2,3,7,8-PenCDD possessing the potent acute toxicity comparable to 2,3,7,8-TCDD and higher persistency in the liver might be more important than 2,3,7,8-TCDD in terms of the chronic toxicity.     

Evidence of Delayed Mesangial Transport of Human IgA in Glomeruli of ddY Mice Pretreated with Sheep Anti-type IV Collagen Serum

In order to investigate whether mesangial transport by glomeruli is delayed in ddY mice pretreated with sheep anti type IV collagen serum, the mice were administered an overload of human IgA myeloma serum. Non pretreated ddY mice used as controls and both experimental and control BALB/c mice were also processed in a similar manner. The intensities of mesangial deposition of human IgA were examined periodically and were found to correlate well with deposition of mouse IgA. Both mouse and human IgAs showed a gradual increase for up to 8 experimental weeks. In the control young ddY mice, however, the overloaded mesangial human IgA quickly disappeared, presenting no appreciable mesangial deposition of autologous IgA. In sharp contrast, both the experimental and control BALB/c mice showed an initially prolonged and rather heavy mesangial deposition of human IgA, followed by a gradual decrease and somewhat light mesangial deposition of autologous mouse IgA. These results obtained using experimental ddY mice appear to confirm the possibility that non immunological local trapping, due to retardation of mesangial transport function, causes mesangial deposition of autologous mouse IgA in this particular strain. Acta Pathol Jpn 39: 289 295, 1989.     

The effects in the excess administration of prostaglandin E1 on the indicator enzymes of organella membrane in gastric mucosa

Administration of excess vitamin A to rats causes gastric ulceration. In this study the effects on the gastric mucosa of excess vitamin A and excess prostaglandin E1, alone and in combination, were studied. Prostaglandin E1 protected against ulceration by vitamin A. Vitamin A labilized marker enzymes from four different membrane systems, namely those of the lysosomes, mitochondria, endoplasmic reticulum and plasma membrane, whereas only the effect on lysosomes was prevented by prostaglandin E1. Indeed, the prostaglandin alone labilized the enzymes from plasma membrane and endoplasmic reticulum and also damaged mitochondrial membranes. Both vitamin A and prostaglandin E1 caused a reduction in the total number and an increase in irregularly-shaped mitochondria in the parietal cells and produced dilation of the endoplasmic reticulum in both parietal and chief cells. It is noteworthy that prostaglandin E1 effectively prevents ulceration by vitamin A despite the extent to which it damages these membrane systems. These findings lend support to the hypothesis that vitamin A ulceration of the gastric mucosa is mediated via release of lysosomal enzymes, following damage to the lysosomal membranes.     

Change of membrane fluidity of rat neutrophils accompanying Escherichia coli inoculation

Membrane fluidity of rat neutrophils was studied following Escherichia coli inoculation, and characteristic changes were observed. Membrane fluidity was assessed by the excimer-forming lipid technique using pyrenedecanoic acid and flow cytometry and expressed as the fluorescence intensity ratios of excimer and monomer pyrenedecanoic acid (IE/IM ratio). High IE/IM ratios indicated high membrane fluidity. The IE/IM ratio of rat neutrophils (0.50 +/- 0.048) increased after E. coli inoculation, reaching a maximum of almost 1.00 after 10-20 min and then returning to its starting value. Intravenous injection of heat-killed E. coli or E. coli-conditioned culture supernatants into rats induced a rapid increase of IE/IM ratios, which returned to initial levels after 20 min. The effect on membrane fluidity of in vitro neutrophil incubation with E. coli, heat-killed E. coli, or E. coli-conditioned culture supernatants was similar to that observed in vivo. Addition of 5 mM ethylenediaminetetraacetic acid (EDTA) did not affect neutrophil membrane fluidity. Addition of either 5 micrograms/ml cytochalasin B or 10(-5) M colchicine did not directly affect neutrophil membrane fluidity but did block the change observed following incubation with bacteria.     

Differentiation of subtypes B and E of human immunodeficiency virus type 1 by polymerase chain reaction using novel env gene primers

Novel sets of env gene PCR primers for distinguishing human immunodeficiency virus type 1 (HIV-1) subtypes B and E were designed. These primers anneal to different regions of the env gene and amplify DNA fragments of distinct sizes in a subtype-specific manner. Blood samples from 11 HIV-1 carriers in Thailand and 46 carriers in Japan were examined by PCR. The new env primers detected HIV-1 proviral DNA in 100% (11/11) and 88% (37/42) of the subtype B and E infection cases, respectively. The env primers also detected proviral DNA in saliva and breast milk samples in seven of 11 cases and two of three cases, respectively. The PCR subtyping results matched completely with those obtained by nucleotide sequencing of the env V3 region. The results suggest that the PCR using the env primers designed in this study may be an accurate and cost-effective method for differentiating subtypes B and E of HIV-1 in a large number of clinical samples. However, subtype E specific primer cross-react with subtype A, C, G, the new primer in this study is useful for regions in South East Asia where subtype E is predominant.