Multi-directional positron imaging: evaluation of cancer detection with 2-(F-18)-fluoro-2-deoxy-D-glucose

We developed a multi-directional positron imaging system for the whole body in order to evaluate the spatial distribution of radiopharmaceuticals. A positron emission tomography (PET) scanner with ring detectors was modified to provide 54 directional planar images with a three-dimensional appearance by using cinematic display. The initial clinical evaluation was performed on two normal volunteers and 17 cancer patients with 32 foci. Images were obtained approximately one hour after the intravenous administration of 2-(F-18)-fluoro-2-deoxy-D-glucose. In all 19 subjects, good quality images with a three-dimensional appearance were obtained. We were able to visualize 16 of 20 (80%) lesions that were three centimeters or more in greatest diameter. In contrast, only seven of 12 (58%) lesions less than three centimeters in greatest diameter were identified. The overall detectability of lesions was 72%. These results suggest that this system will be useful for tumor detection.

Increased uncoupling of beta-, beta 1- and beta 2-adrenoceptor to myocardial contraction in failing human myocardium

Coupling of myocardial beta-, beta 1-, beta 2- and alpha-adrenoceptors (AR) to myocardial contraction was investigated in patients with various degrees of heart failure. With the use of delta Vcfc, a load independent parameter of myocardial contraction, AR mediated contraction was evaluated. beta-AR mediated contraction, delta Vcfc by infusion of a beta-AR agonist, isoproterenol, declined with the advancement of heart failure from 0.41 Circ/sec (NYHA I) to 0.31 (NYHA II), 0.22 (NYHA III) and 0.12 (NYHA IV). Dobutamine, a beta 1-AR full agonist, mediated delta Vcfc was 92-97% of that of isoproterenol. On the other hand, terbutaline sulfate, a full agonist to beta 2-AR, increased delta Vcfc partially in comparison with isoproterenol; 51% in NYHA I, 52% in NYHA II, 36% in NYHA III and 17% in NYHA IV. An alpha 1-AR agonist, methoxamine had little effect on myocardial contractility beta-AR and alpha-AR densities were analyzed by saturation binding isotherms of myocardial membrane fraction with 125I-Iodocyanopindolol (ICYP) and 3H-Bunazosin, respectively. beta-1 and beta 2-ARs were separated by competition binding of 125ICYP with a highly selective beta 1 AR antagonist, CGP20712A. There was a progressive down regulation of beta, beta 1- and beta 2-ARs with the advancement of heart failure. A new index was used to examine coupling of ARs to myocardial contraction; Coupling Index. The index was slightly decreased in NYHA II in beta- and beta 1-ARs. In beta 2-AR, the coupling index declined as heart failure advanced from NYHA I to NYHA IV.(ABSTRACT TRUNCATED AT 250 WORDS)

[General pharmacology of cefepime]

General pharmacological properties of cefepime (CFPM), a new injectable semisynthetic cephalosporin and its metabolite N-methylpyrrolidine-N-oxide (NMP-N-oxide) were studied in laboratory animals. The results obtained are summarized as follows: 1. CFPM reduced spontaneous locomotor activity but potentiate the anesthesia at the highest dose in mice. Furthermore, significant hypothermia and analgesia were observed at the same dose in mice. No effects were found on the other CNS function in mice and rats or on EEG activities in rabbits. 2. Muscle relaxant activity was not observed in mice treated with CFPM even at the highest dose. 3. CFPM had no effect on the intestinal smooth muscle and did not show any antagonism against some smooth muscle contracting drugs. 4. The respiration, blood pressure, heart rate and ECG were affected by CFPM. Those changes, however, might have been principally caused by L-arginine blended with CFPM product. 5. No effect of CFPM on the intestinal movement or gastric secretion was found even at the highest dose of CFPM. 6. The pH neutralizer L-arginine caused alterations in the renal function and electrolyte metabolism but CFPM did not. 7. Whole blood clotting time tended to be lengthened by CFPM at the highest concentration but this effect seemed to have been caused by L-arginine. Other parameters of the coagulation system or red blood cell resistance were not affected by CFPM. 8. NMP-N-oxide, a metabolite of CFPM, had almost no effect on any of the tested parameters except for its slight effect on the circulatory system. These findings indicate that CFPM has scarcely any pharmacological properties which might be leading to severe adverse reactions in clinical use.

Immunocytochemical demonstration of salmon GnRH and chicken GnRH-II in the brain of masu salmon, Oncorhynchus masou

We have recently developed sensitive and specific radioimmunoassays (RIAs) for salmon gonadotropin-releasing hormone (sGnRH) and chicken GnRH-II (cGnRH-II) and have measured the contents of both GnRHs in the rainbow trout brain. Our results showed that contents of the two GnRHs are variable among different brain regions. Therefore, in order to confirm the differential distribution of the two GnRHs by a different technique, we examined the distribution of immunoreactive sGnRH and cGnRH-II in the brain of masu salmon by using immunocytochemical techniques. sGnRH immunoreactive (ir) cell bodies were scattered in the transitional areas between the olfactory nerve and the olfactory bulb, the ventral olfactory bulb, between the olfactory bulb and the telencephalon, the ventral telencephalon, and the preoptic area. These sGnRH-ir cell bodies were dispersed in a strip-like region running rostrocaudally in the most ventral part of the ventral telencephalon. sGnRH-ir fibers were distributed in the various brain regions from the olfactory bulb to the spinal cord. They were especially abundant in the olfactory bulb, ventral telencephalon, preoptic area, hypothalamus, deep layers of the optic tectum, and thalamus. sGnRH-ir fibers also innervated the pituitary directly. cGnRH-II-ir cell bodies were found in the nucleus of the medial longitudinal fasciculus (nMLF). The distribution of cGnRH-II-ir fibers was similar to that of sGnRH-ir fibers, except that cGnRH-II-ir fibers were absent in the pituitary. The number of cGnRH-II-ir fibers was much fewer than that of sGnRH-ir fibers. The results of the present immunocytochemical study are in basic agreement with those of our previous RIA study. Thus, we suggest that in masu salmon, sGnRH not only regulates gonadotropin (GTH) release from the pituitary but also functions as a neuromodulator in the brain, whereas cGnRH-II functions only as a neuromodulator.

Immunofluorescence-digital image processing system for the quantitation of secreted immunoglobulin by single cells

To quantitate the amount of secreted immunoglobulin (Ig) by a single cell, the immunofluorescence digital image processing (IDIP) system was adapted to the modified enzyme-linked immunospot (ELI-SPOT) assay. In this assay, an immunofluorescence (tetramethylrhodamine isothiocyanate) conjugated antibody was used for the detection of spots instead of the usual method of enzyme coupling. We have named this the immunofluorescence-linked immunospot (ILISPOT) assay. In addition to the quantitation of secreted Ig by single cells, this method allowed us to objectively determine the exact number of Ig producing spot forming cells (SFC). 96 well culture plates were pre-coated with goat anti-mouse Ig. The mouse IgM producing hybridoma (E-3-4) was incubated in the plates for 4 h at 37 degrees C. Cells were removed prior to the addition of biotinylated goat anti-mouse mu antibody. After overnight incubation, immunofluorescence conjugated avidin was added for the visualization of spots by the IDIP system. The IDIP system consists of a fluorescent microscope equipped with a video camera and computer. The gray scale of secreted IgM was initially established as a standard by the known amount of purified IgM. By using digital image processing, the number of spots and the gray scale of individual spots were computed. The shape and pattern of gray scale data were used to distinguish between the real spots and pseudo spots. This IDIP system could detect as little as 0.19 pg of secreted IgM (1.2 x 10(5) molecules) and an average of approximately 1.33 pg (8.3 x 10(5) molecules) produced by a single cell. Adaptation of the digital image processing system to the ILISPOT assay allowed the measurement of both the amount of Ig produced at the single cell level and also the exact numbers of SFC present in a totally objective fashion.

[An analysis of participation rates for health and cancer screenings in Wakabayashi ward of Sendai]

Persons who were non-employed as determined from the 1985 census were assumed to be the target population for health and cancer screenings, comprising 54.8% and 55.5% of both the male and female population over 40 years of age in Sendai and in Wakabayashi ward respectively. Similar mean participation rates were obtained for health screening from 1986 to 1989 of 24.0% in Sendai and 23.3% in Wakabayashi ward. However, mean participation rates differed for gastric cancer screening, being 18.2% in Sendai and 15.8% in Wakabayashi ward. Both screening rates increased from 1986 to 1989 in Sendai as well as in Wakabayashi ward. Rates for both screenings were high in the suburbs and low in metropolitan Wakabayashi ward. The target population for uterine and breast cancer screenings were 69.8% and 70.1% of women over 30 years of age in Sendai and in Wakabayashi ward respectively. Mean participation rates for uterine cancer screening from 1986 to 1989 were 33.8% in Sendai and 35.1% in Wakabayashi ward, and showed an overall decrease from 1987 to 1989 in both Sendai and Wakabayashi ward. The rate was high in the suburbs and low in metropolitan Wakabayashi ward. Mean participation rates for breast cancer screening from 1988 to 1989 were 13.9% in Sendai and 13.6% in Wakabayashi ward, with rates being low in both the suburbs as well as metropolitan. Wakabayashi ward in 1988 (the beginning year of the screening), but increasing significantly in the suburbs during the following year.

Differences in salmon GnRH and chicken GnRH-II contents in discrete brain areas of male and female rainbow trout according to age and stage of maturity

We have developed sensitive and specific radioimmunoassays (RIA) for salmon gonadotropin-releasing hormone (sGnRH) and chicken GnRH-II (cGnRH-II). Synthetic sGnRH and cGnRH-II(2-10) were conjugated to bovine serum albumin and injected into rabbits to raise specific antisera. The antiserum against sGnRH showed cross-reactivities of 1.58 and 0.08% for cGnRH-II and lamprey GnRH, respectively. The antiserum against cGnRH-II showed cross-reactivities of 0.05 and 0.01% for sGnRH and lamprey GnRH, respectively. Both antisera were observed not to cross-react with mammalian GnRH and cGnRH-I or other peptide hormones. Synthetic sGnRH and cGnRH-II were iodinated using the chloramine-T method. The iodinated GnRH was purified by HPLC using a reverse-phase C18 column. The RIA system was developed as a double antibody method. Brain extracts of rainbow trout showed displacement curves which were parallel to the sGnRH and cGnRH-II standards in each RIA. HPLC analysis followed by RIA has revealed that rainbow trout brain contains two types of GnRH: sGnRH and cGnRH-II. Total sGnRH content in the brain was about three-fold higher than that of cGnRH-II. In the olfactory bulbs, telencephalon, optic tectum-thalamus, hypothalamus, and pituitary, sGnRH content (per region) was higher than cGnRH-II content, whereas cerebellum and medulla oblongata contained much more cGnRH-II than sGnRH. sGnRH content in the optic tectum-thalamus and pituitary was the highest in 1-year-old immature fish and 3-year-old mature fish, respectively. Medulla oblongata showed the highest cGnRH-II content in all groups. sGnRH concentrations (per milligram of protein) were high in the pituitary and intermediate in the olfactory bulbs, hypothalamus, and telencephalon. In all groups, the cGnRH-II concentration was high in the medulla oblongata, whereas the concentration in the olfactory bulbs and pituitary gland was below the detectable limit in most individuals.

[General pharmacology of BMY-28100]

General pharmacological properties of BMY-28100, a new semisynthetic oral cephalosporin, were studied in experimental animals. The obtained results are summarized as follows: 1. BMY-28100 had no effect on gross behavior and the central nervous system in mice and rats nor on EEG activities in rabbits. 2. BMY-28100 did not affect the smooth muscle isolated from rats, guinea pigs or rabbits nor did it influence ganglionic transmission in cats. 3. Effects of BMY-28100 on the atrium and heart isolated from guinea pigs were not obvious. Several parameters of the cardiovascular system were examined and found unchanged by administration of BMY-28100 to rabbits. 4. In the digestive system, BMY-28100 had no effect on charcoal meal transport in the small intestine of mice. In rats, however, gastric secretion was reduced at a dose level of 125 mg/kg or higher and bile secretion was enhanced at a dose level of 500 mg/kg. 5. BMY-28100 had no effect on neuromuscular transmission in rabbits and showed no local anesthetic activity in guinea pigs. 6. BMY-28100 decreased urine volume and urinary excretion of electrolytes in dose-dependent manners in rats. Sulfobromophthalein excretion in rats was inhibited only at the highest dose tested. BMY-28100 had no effect on blood coagulation and red blood cell resistance in rats or rabbits. BMY-28100 revealed no antiinflammatory activity in rats. 7. BMY-28167, a trans-isomer of BMY-28100, had no or weak effects on some of above test systems when compared with BMY-28100. These results suggest that BMY-28100 has hardly any pharmacological properties leading to severe adverse reactions in clinical use.

Ciliated hepatic foregut cyst: radiologic features

Ciliated hepatic foregut cysts (CHFCs) are solitary unilocular cysts in the liver that are histologically similar to bronchogenic cysts. Three cases of CHFC are reported that demonstrated radiologic features similar to those of solid masses. All the lesions were smaller than 3 cm in diameter and were subcapsular. At ultrasonography, one lesion appeared anechoic but the other two were hypoechoic. Unenhanced computed tomography demonstrated the lesions to be hyperattenuating or isoattenuating relative to surrounding liver parenchyma, and no lesions enhanced with administration of contrast material. Magnetic resonance imaging was performed in one case and demonstrated the lesion to be markedly hyperintense with a spin-echo (SE) 2,500/80 (repetition time msec/echo time msec) sequence. All the lesions were resected and found to be filled with viscous mucinous fluid. The CHFCs are not neoplasms and must be differentiated from cystic neoplasms and hypovascular solid tumors. When a subcapsular lesion demonstrated the varied appearance described, a diagnosis of CHFC should be considered.

[NK- and T-cell granular lymphocyte-proliferative disorders]

For the disease of the granular lymphocytes (GL) that contain azurophilic granules to proliferate in the peripheral blood, which is often complicated by anemia or neutropenia and which generally develop into chronic disease, the new designation of granular lymphocyte-proliferative disorders (GLPD) is being proposed. This disease include T-GL having CD3 antigen which forms a complex with T cell Ag receptor (TCR-alpha beta), and NK-GL which is CD3-negative but CD16- or NKH-1-positive, having non-MHC-restricted cytotoxicity. The two cases presented here demonstrate the characteristics of T-GL or NK-GL, however, while one case with NK-GL showed spontaneous decrease of GL, improvement of neutropenia and anemia without any treatment, the other case with T-GL became intractable and required repeated blood transfusion. On such differences in the clinical development of the disease, we have conducted investigations including a review of the literature to see whether there is any correlation between the characteristics of the proliferating cells and pathologic conditions of the disease, and whether this disease is indeed tumorous.

One-electron reduction of the oxy form of cobalt-substituted hemoproteins

The reduction of oxy forms in cobalt-substituted hemoproteins by the hydrated electron (e(aq)-) was investigated by pulse radiolysis. The hydrated electron (e(aq)-) reacted with the oxy form of cobalt horseradish peroxidase (CoHRP) to form CoHRP. On the other hand, the initial product observed in the reaction of the oxy form of cobalt myoglobin (CoMb) with e(aq)- is neither CoMb nor Co3+ Mb. Subsequently, the product was found to convert to another form, the irreversible change in the porphyrin. In contrast to e(aq)-, both oxy forms of CoMb and CoHRP were reduced by various electron donors to form the cobaltic forms.

[Synthesis of 4,5-diarylthiazole derivatives as blood platelet aggregation inhibitors]

A number of 2-substituted 4,5-diphenylthiazoles were synthesized by the nucleophilic substitution of 2-methylsulfonyl-4,5-diphenylthiazole with various sodium alkoxides, amines, and carbanions of active methylene compounds. 2-Methylsulfonyl-4,5-diphenylthiazole was obtained by the potassium permanganate oxidation of 2-methylthio-4,5-diphenylthiazole in the presence of a phase-transfer catalyst. 2-Ethoxy-4,5-bis(4-methoxyphenyl) thiazole was prepared in a similar manner. 2-Ethynyl-4,5-diphenylthiazoles were synthesized by the palladium catalyst cross-coupling reaction of 2-iodo-4,5-diphenylthiazole with monosubstituted acetylenes. These compounds were tested for inhibitory activity against blood platelet aggregation in vitro. Among them, 2-alkoxy-, and 2-(4-methylpiperazin-1-yl)-4,5-diphenylthiazole were found to have potent inhibitory activity.

Age-related reduction in the number of rabbit erythrocyte Na, K-ATPase

The number of Na, K-ATPase units, assessed by [3H]-ouabain binding assay, was significantly less in erythrocytes from 17 mature (30-week) rabbits than in those from 17 young (16-week) ones (0.179 +/- 0.010 vs. 0.263 +/- 0.014 pmol/10(9) cells, p less than 0.01). Consistent with this finding, the erythrocyte sodium concentration was significantly higher in mature rabbits as compared with young animals (17.1 +/- 1.30 vs. 10.8 +/- 0.68 mmol/liter, p less than 0.01). When the assays were repeated in 8 of the young rabbits 8 weeks after the initial determination, both variables were found to be similar to the levels from mature animals. The data suggest that the activity of erythrocyte sodium pump declines with aging or growth of donor rabbits, as a result of a reduction in the number of Na, K-ATPase units.

[T-cell lymphomas of the skin: a study of 7 cases excluding mycosis fungoides and adult T-cell leukemia/lymphoma]

Seven cases of T-cell lymphomas of the skin, excluding mycosis fungoides and adult T-cell leukemia/lymphoma, treated at the Department of Dermatology, Miyazaki Medical College for the previous 5 years were studied. Five were males and 2 were females, with a mean age of 61 years. Six patients presented either multiple skin tumors or subcutaneous indurations. Histologically, all cases presented dense infiltrations of the tumor cells showing variable morphological characteristics. Surface markers were also variable, suggesting that these were not a single entity. Treatment consisted of chemotherapy in 5 cases and electron beam therapy in 5 (localized in 4 and generalized in 1). Complete remission was obtained in 5 cases. The mean period from the first examination to death in the three fatal cases was 11.7 months, and the mean period of observation from the first examination to the present time in 4 cases ranged from 12 months to 40 months. Clinicopathological characteristics of these cases were compared with those of adult T-cell leukemia/lymphoma.

[Initial symptoms of hematemesis from gastric varix with chromosomal abnormalities of t(2; 8) and 14q+ in a patient with acute lymphoblastic leukemia (FAB: L3)]

A 71-year-old woman was hospitalized because of hematemesis on December 1, 1987. Her white blood cell (WBC) count was 41,200/microliters with 48% of lymphoblasts, and the bone marrow was hypercellular with more than 90% of blasts. The diagnosis of acute lymphoblastic leukemia (ALL) (FAB: L3) was made by morphologic, cytochemical and immunologic studies of the blasts. The examination of fiber gastroscope revealed remarkable varix in the stomach, suggesting portal hypertension accompanied by infiltration of leukemic cells into reticulo-endothelial system. She died of respiratory failure because of bleeding into the trachea. The autopsy disclosed the massive infiltration of leukemic cells into the whole organs. In the chromosome study of the peripheral blood, t(2; 8) and 14q+ were observed, and these chromosomal abnormalities are relatively unusual in patients with Burkitt's lymphoma.

[Megakaryocytic leukemia with thrombocytosis]

A 62-year-old man was admitted to our hospital with exertional dyspnea. On admission, neither hepatosplenomegaly nor lymphadenopathy were noted. Laboratory data revealed anemia (Hb, 4.8 g/dl), leukopenia (2,800 microliters) and a normal platelet count (21 X 10(4)/microliters). The immature blast cells in the peripheral blood were 15%, which increased to 32% during his clinical course. On cytochemical studies, the blast cells had no staining with peroxidase, alpha-naphthyl-butyrate esterase and PAS, although acid phosphatase was positive. More than 58% of the blasts were identified as being of megakaryocytic lineage by platelet peroxidase and by tests with monoclonal GP IIb/IIIa antibody. Bone marrow biopsy disclosed marked fibrosis. However, the patient constantly had normal counts of platelets ranging from 21 X 10(4) to 63 X 10(4)/microliters. This case provides evidence that the megakaryocytic leukemias can be categorized into two types, which are characterized by either undifferentiated or differentiated megakaryocytic leukemia cells.

Scleral fibroblasts of the chick embryo proliferate by an autocrine mechanism in protein-free primary cultures: differential secretion of growth factors depending on the growth state

Scleral fibroblasts of the chick embryo in primary culture proliferated in a protein-free medium. Conditioned medium (CdM) from the culture contained plural growth-promoting factors, which were active to the same cell type. The activity of one of the growth-promoting factors (SAF-I) was heat-resistant and the rest (SAF-II) were heat-sensitive. SAF-I accumulated in the CdM only during the growing phase; on the other hand, SAF-II accumulated in the CdM during the stationary phase. SAF-I showed the same time course of DNA synthesis-promoting activity as human PDGF. However, the activity of the SAF-I was not neutralized by anti-human PDGF. On the other hand, a part of the SAF-II (SAF-II a) showed a strong affinity for heparin.

[Treatment of multiple myeloma with LAK cells plus interleukin 2 or interleukin 2 alone]

Three patients with multiple myeloma were treated with 3.3-10 x 10(5) u/day intravenous or subcutaneous IL 2 alone. Both their Leu7 and CD16 positive cells in the peripheral blood and NK and LAK cell activity elevated but no M protein decreased. LAK cells and IL-2 administered to three patients intravenously. Lymphocyte counts in the peripheral blood elevated remarkably in one patient and CD3, 8, 16, 2, 38, Leu7 positive cells and NK cell activity increased in three patients. Though the reduction of M proteins were observed in three patients (17%, 75.8% and 40%, respectively), they returned to pretreatment level in 35 days, 55 days and 200 days after the therapy. Significance of the therapy against multiple myeloma was discussed.

Purification of an autocrine growth factor in conditioned medium obtained from primary cultures of scleral fibroblasts of the chick embryo

Scleral fibroblasts of the chick embryo were found to secrete autocrine growth factors. One of the factors was purified from conditioned medium collected from growing-phase cultures of these cells by DEAE-Sepharose column chromatography and following non-denaturing polyacrylamide gel electrophoresis. The specific activity was increased 1100-fold by this purification. The chromatographically purified growth factor was still active after incubation at 95 degrees C, at pH 10 or pH 3, or with glycosidase H, but inactive after incubation with dithiothreitol or trypsin. An active protein having a molecular weight of 32 kDa was found to be the major component of the final preparation.

[A comparative study on lomefloxacin and norfloxacin in the treatment of acute uncomplicated cystitis]

To objectively evaluate the efficacy, safety and utility of lomefloxacin (NY-198), a new quinolone antibacterial agent, in the treatment of acute uncomplicated cystitis, a comparative double blind trial was performed using norfloxacin (NFLX) as the control drug. In both groups, the drug was orally administered after meals for 3 days in a dose of 100 mg t.i.d. and clinical efficacies were assessed on the 3rd day (the 1st assessment) according to the criteria by the UTI Committee in Japan. Subsequently, either the active drug (NY-198 or NFLX) or placebo was administered for 4 days and the 2nd assessment was performed on the 7th day. Further, in patients who showed excellent responses at the 2nd assessment, recurrence was examined on the 14th day (the 3rd assessment) and on around the 21st day (the 4th assessment) following a subsequent 7-day placebo treatment. 1. A total of 258 patients was treated, and among them clinical efficacies were evaluable in 207 patients (NY-198: 106, NFLX: 101) at the 1st assessment, and in 176 patients (NY-198-NY-198 which was the combination of the 1st and 2nd administrations: 47, NY-198-placebo: 43, NFLX-NFLX: 44, NFLX-placebo: 42). 2. In the evaluation of overall clinical efficacy by the committee at the 1st assessment, the overall efficacy rates in the NY-198 group and the NFLX group were 76.4% and 64.4% (excellent), respectively, or 100% and 99.0% (excellent and good), respectively. There was no statistically significant difference between the 2 groups. In the 1st assessment on effects of drugs on pain at micturition, pyuria and bacteriuria and on bacteriological response, no significant differences were observed between the 2 groups. 3. In the 2nd assessment by the committee, there were statistically significant differences among the 4 groups in the overall clinical efficacies and the effects on bacteriuria (P less than 0.05). No difference was observed between NY-198 group and NFLX group, but the groups administered with active drug for 7 days, i.e. NY-198-NY-198 group and NFLX-NFLX group were significantly superior to the groups administered with active drug for 3 days and placebo for subsequent 4 days, i.e. NY-198-placebo group and NFLX-placebo group (P less than 0.05). There were no differences in the effects on pain at micturition and pyuria among the 4 groups.(ABSTRACT TRUNCATED AT 400 WORDS)

[Design concepts and preliminary performances of stationary-sampling whole-body high-resolution positron emission tomography: HEADTOME IV]

Design concepts and preliminary performances of a stationary sampling high-resolution whole-body positron emission tomograph, HEADTOME IV, were reported. The system comprises four layers of detector ring which consists of 768 BGO crystals with 3 mm width, 96 photomultiplier tubes arrayed on 825 mm circle. A sufficiently fine sampling-interval allows data sampling without scan motion along the transaxial plane. But an axial motion (Z-motion) is installed to interlace between adjacent planes. Preliminary performance characteristics were an in-plane resolution of 4.5 mm in full width at half maximum (FWHM), an axial resolution of 9.5 mm in FWHM, sensitivities of 14 and 24 kcps/(microCi/ml) for direct and cross planes, respectively, with 20 cm diam. cylindrical flood phantom. A large scale cache memory prepared for each plane allows a realtime correction for the deadtime and the radionuclide decay, and a realtime calculation of the rate constants using the weighted integral method.