[Constant infusion system of 15O labeled-water]

The quantitative measurement of regional blood flow and regional extravascular lung water, called for a design of 15O labeled water production and administration under continuous and constant flow. In our search for simple methodology, suitable for clinical routine facilities, two remote-controlled systems were designed and their applicability for continuous and constant infusion of H215O were tested. In system (A), H215O was prepared from C15O2 based on the fast exchange reaction between carbon dioxide and carbonic acid. In the system (B), the reaction of 15O2 with H2 using palladium as a catalyst was adopted. In the both systems, the radioactivity level of the infusate was kept constant by using a buffer reservoir. Clinical applicability of both fully automated systems for the production of sterile H215O at a continuous and constant rate was discussed. Namely, system (A), being very simple seems more suitable for any closely located facility but system (B) is more suited for the production of higher radioactivity.

Further study on a BF silent allele

A family was found which indicated the existence of a silent allele (BF*QO) at the locus for complement factor B. Three generations with eight members were studied. Four individuals were considered to be heterozygous for B deficiency because of unusual segregation patterns of the BF electrophoretic variants and low levels of B. Haplotype study on the other HLA-linked markers supported the presumption. No unusual products were detected by immunoblotting after sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE).

Carrier-added and no-carrier-added syntheses of [18F]spiroperidol and [18F]haloperidol

Syntheses of [18F]haloperidol and [18F]spiroperidol in both no-carrier-added and carrier-added forms have been accomplished. The no-carrier-added [18F]butyrophenone neuroleptics were prepared in low (less than 2%) yield by acid decomposition of aryl piperidine triazenes. Carrier-added 18F-neuroleptics were prepared in better (5-17%) yields by 18F-for-19F nucleophilic aromatic substitution. The preparation of all synthetic precursors, and procedures for radiolabeling are fully described.

Monoclonal antibodies to hepatitis B surface antigen (HBsAg) as a tool for the automated HBsAg screening

Hybridomas secreting monoclonal antibodies to hepatitis B surface antigen (HBsAg) were established by fusion of the spleen cells from mice immunized with purified HBsAg with the mouse myeloma cell line P3-NSI/1-Ag4-1. The monoclonal antibodies to the group-specific antigen (a) produced by one of them were used for the automated screening of HBsAg on the Groupamatic 360 (Kontron International). Its sensitivity is almost equal, but slightly inferior, to the system employing polyclonal horse antibodies to HBsAg; it barely detects 6 ng/ml of HBsAg. It is also as highly specific as the system with polyclonal antibodies; the incidence of false-positive reactions is 0.2%. These results indicate that the monoclonal antibodies will become a practical source for the HBsAg screening on the Groupamatic.

Deferoxamine, a promising bifunctional chelating agent for labeling proteins with gallium: Ga-67 DF-HSA: concise communication

A new efficient method has been developed for the labeling of various biologically important proteins with radiogallium, using deferoxamine (DF) as a bifunctional chelating agent. Human serum albumin (HSA) was chosen for studying the DF coupling reaction by a glutaraldehyde two-step method. The DF-HSA conjugate obtained was then easily labeled with Ga-67 with high efficiency and reproducibility. High stability of the Ga-67 DF-HSA was observed both in vitro and in vivo. In rats the half-time of blood clearance at the first phase was 234 min for the Ga-67 DF-HSA, whereas most conventional I-131 HSA gives 121 min. The excellent pharmacological and physiological properties were assessed by plasma clearance and plasma volume measurements in normal volunteers. Even at 2 hr after injection, (90.0 +/- 3.0)% of Ga-67 DF-HSA was retained within the vascular space. The mean plasma volume per kilogram of body weight, measured with Ga-67 DF-HSA, was 46.6 +/- 3.4 ml/kg, compared with 52.2 +/- 2.4 ml/kg as determined with I-131 HSA in the same men.

HLA-DR antigens in Japanese with Hashimoto's thyroiditis and Graves' disease

HLA-A, -B, -C and -DR specificities were determined to study the association of HLA in 49 unrelated patients with Hashimoto's thyroiditis and 51 patients with Graves' disease. The results were compared with 144 control subjects from the Japanese population at large. Much less HLA-DR2 was found in the patients with Hashimoto's thyroiditis than in the normal controls. It was present in 16% of the thyroiditis patients compared to 39% in the controls. Also the frequency of HLA-DRl was less in the patients with Graves' disease (0%) than in the controls (15%). No positive association was found for any HLA-antigens in the two diseases.

HLA-DR specificities among Japanese with several autoimmune diseases

HLA-A, -B, -C, and -DR antigens were determined in order to study the association of HLA in Japanese patients with several autoimmune diseases, hypertrophic cardiomyopathy, and Hodgkin's disease. The frequency of HLA-DR4 was significantly increased in the patients with rheumatoid arthritis, juvenile-onset insulin-dependent diabetes mellitus (IDDM) and hypertrophic obstructive cardiomyopathy. In this study, no significant associations with A, B, or C specificities were observed except BW22 in IDDM. In contrast, the negative association with HLA-DR2 was observed in Hashimoto's thyroiditis, pemphigus vulgaris and hypertrophic non-obstructive cardiomyopathy.

Analysis of 99mTc-pyridoxylidene-glutamate complex formation and its preparation with tin-adsorbed-resin: Sn-Resin kit method

99mTc-Pyridoxylidene-glutamate (Tc-PG) was introduced in 1975 by Baker et al. as a cholescintigraphic agent. Nevertheless its routine use has been limited due to the autoclaving process involved. To shorten the labeling procedure, an analysis of Tc-PG complex formation using the stannous chloride method was carried out. Sn-Resin (stannous ion adsorbed onto cation exchange resin) was used for labeling a stable Tc-PG with high efficiency. A preautoclaved complex of pyridoxal and glutamate was required but the labeling procedure took only 10-15 min after the elution of 99m-TcO4- from the generator. Formation of a complex other than a 99mTc-complex of the Schiff -base ligand pyridoxylidene-glutamate is discussed. The new formulation of a Tc-PG kit (Sn-Resin) simplified the labeling method and reproducible data to that already reported by Baker was obtained in chromatographic studies. Its suitability in hospital departments has already been shown in clinical studies.

Technetium coordination state as a factor of stability in 99mTc-complexes used in hepatobiliary system: comparative studies on 99mTc-complexes of pyridoxal with glutamate (Tc-PG) and isoleucine (Tc-PI)

Studies on 99mTc-Penicillamine (Tc-Pen) have given us some insight into the significance of the technetium coordination state in hepatobiliary clearance behavior. A 99mTc-complex of pyridoxal and glutamate (Tc-PG) prepared by Baker et al. (1975) using an autoclaving process or by a Sn-Resin kit method (Horiuchi 1981) was compared with a 99mTc-complex of pyridoxal and isoleucine (Tc-PI) prepared by the method of Kato and Hazue (1978) through an intermediate compound of stannous ion, at room temperature. Tc-PG and TcPI complexes analyzed by thin layer chromatography, sephadex column chromatography (G-15), octanol extraction, and ligand exchange reaction showed different chemical properties. Their biological evaluation also demonstrated great differences in biodistribution in mice, metabolic studies, protein binding, and rat bile excretion. Tc-PG was estimated as an hepatobiliary agent with strong metal-ligand binding, inert to ligand exchange reaction with Pen at physiological pH; the likely occurrence of technetium in a mononuclear or dinuclear state providing the great stability observed in its biological and in vivo behavior was compared with the relatively weaker binding observed in Tc-PI, a highly lipophilic complex of high liver partition but of low stability, denoting its different chemical characteristics. The technetium coordination state in radiopharmaceuticals is responsible for the integrity of the molecule while in the blood pool and its relevance in impaired liver uptake is discussed.

A method for the automated screening for hepatitis B surface antigen

A reverse passive hemagglutination (RPHA-G) technique for the automated screening of hepatitis B surface antigen (HBsAg) on the Groupamatic 360 (Kontron International, Zürich, Switzerland) has been developed. It is more sensitive than manual RPHA (RPHA-M) and nearly as sensitive as radioimmunoassay (RIA); it detects 6 ng/ml of HBsAg, compared to 3 ng/ml by RIA and 25 ng/ml by RPHA-M. Although it is slightly inferior to the other two methods in respect of specificity, the incidence of false-positive reactions was only 0.34%. The test can also be performed manually without the Groupamatic.

[Enhancement of 67Ga tumor-to-blood ratios by chelating agent (author's transl)]

Chelating agent, such as CaEDTA, CaDTPA, D-penicillamine, DMSA, desferoxamine, NTA, cysteine ethyl ester, BAL, alpha-MPG, phthalein complexone, were tested as a possible contrast enhancing agent for tumor imaging with 67Ga-citrate. The intravenous administration of a chelating agent to Ehrlich's tumor bearing mice, one hour after the injection of 67Ga-citrate, accelerated the blood clearance with only a very slight change of activity in the target, increasing the tumor-to-blood ratio, and consequently achieving a better visualization. Among the tested chelating agents, D-penicillamine showed the highest target-to-nontarget ratio at a shorter time: a good tumor-to-blood ratio, performed after 24 hr with non-treated animals, was achieved in only 1-3 hr with post-treated animals. Thus, D-penicillamine hold a considerable promise as a contrast enhancing agent for future clinical use.

A Japanese Rhmod family: serological and haematological observations

This report describes a Japanese family have two Rhmod members, and two sibs with slightly depressed Rh antigens. It is proposed that the Rhmod and the depressed Rh antigen phenotypes are due to regulator genes in homozygous or heterozygous condition, respectively. The two Rhmod members showed mild reticulocytosis, stomatocytosis, slight anisocytosis, slight hyperchromia and slight punctate basophilia without anaemia. Scanning electron microscopy showed their red cells to be small and of bowl shape. Increased fragility of their erythrocytes was demonstrated by dynamic osmofragility testing using a coil planet centrifuge.

[Caffeine-11C, ephedrine-11C and methylephedrine-11C: Synthesis and distribution in mice (author's transl)]

Caffeine, ephedrine and methylephedrine were labeled with carbon-11 by the action of methyliodide-11C on theophylline, norephedrine and ephedrine, respectively. Caffeine-11C was prepared in 44 min with a radiochemical yield of 40%, ephedrine-11C in 45 min with a 11% radiochemical yield and methylephedrine-11C in 36 min with a 43% radiochemical yield. When injected in mice intravenously, these products show a high uptake in the liver, the kidney and the blood for caffeine-11C and in the liver and the kidney for ephedrine-11C and methylephedrine-11C. The brain uptake for these products was found to be 2.4 to 3.9% of the injected dose per gram at 5 min after injection. These studies in mice have demonstrated that these products are potentially useful agents for the dynamic studies of the brain.