Scintillation proximity assay (SPA) is a unique type of radioimmunoassay and makes it possible to use radioisotopes for monitoring binding reactions continuously without separation procedure. Microbeads containing a fluorophor are covalently linked to antibody or receptor. When a radiolabeled antigen or ligand is added it binds to the beads and the emitted short range electrons, excite the fluorophor in the beads. The light emitted can be measured in a scintillation counter. 3H or 125I has been used for SPA. The sensitivities achieved with SPA are comparable to the sensitivities of other procedures. SPA is applicable to immunology, receptor binding, monitoring interactions of biomolecules and study for the kinetics of interaction between receptors and ligands.
Allergy and Immunology ; Kinetics ; Ligands ; Microspheres ; Radioimmunoassay ; Radioisotopes ; Scintillation Counting

This investigation was undertaken to study the mechanisms involved in the absorption of blood from the vitreous, and was divided into following experimental groups: A) Eyes injected with 0.1 cc whole blood (7 eyes). B) Eyes injected with 0.1 hemolyzed blood (7 eyes). C) Eyes injected with 0.1 cc (12IU/0.1ml) urokinase solution after 0.1 cc whole blood injection (7 eyes). D) Eyes injected with 0.1 cc whole blood after 0.5 cc vitreous aspiration (7 eyes). E) Combined group of C) and D) (7 eyes). In each experimental group. simulated vitreous hemorrhages were induced in rabbits by intravitreal injection of 0.1 ml autologous radioactive chronim (51Cr) tagged blood through the pars plana at 12 o'clock position. Thereafter, the author counted the rates of change of radioactivity of the eyes with a scintillation counter everyone day during 10 days and their percentages were obtained. The results obtained were as follows: 1) The average rate of removal of whole blood group from the vitreous cavity(1/2-life; time required for 50% of the injected radioactivity to disappear) was approximately 1/5 times those of hemolyzed group and combined group, and 2/5 times that of urokinase group, 3/5 times that of vitreous aspiration group. 2) The average rate of removal of w hloe blood group from the vitreous cavity (3/4-life; time required for 75% of the injected radioactivity to disappear) was approximately 1/3 times that of hemolyzed blood, and 1/5 times those of urokinase group and combined group. 3) From those results, it was concluded that diffusion of blood elements and hemolysis, alternation of vitreous structure itself were closely related to the absorption of vitreous hemorrhage.
Absorption* ; Diffusion ; Hemolysis ; Intravitreal Injections ; Rabbits ; Radioactivity ; Scintillation Counting ; Urokinase-Type Plasminogen Activator ; Vitreous Hemorrhage*

PURPOSE: 14C-urea breath test (UBT) is a non-invasive and reliable method for the diagnosis of Helicobacter pylori (HP) infection. In this study, we evaluated the diagnostic performance of a new and rapid 14C-UBT (Heliprobe method), which was equipped with Geiger-Muller counter and compared the results with those obtained by using the conventional method. MATERIALS AND METHODS: Forty-nine patients with dyspepsia underwent gastroduodenoscopy and 14C-UBT. A 37 KBq 14C-urea capsule was administered to patients and breath samples were collected. In Heliprobe method, patients exhaled into a Heliprobe BreathCard for 10 min. And then the activities of the BreathCard were countered using Heliprobe analyzer. In the conventional method, results were countered using liquid scintillation counter. During gastroduodenoscopy, 18 of 49 patients were underwent biopsies. According to these histologic results, we evaluated the diagnostic performance of two different methods and compared them. Also we evaluated the concordant and disconcordant rates between them. RESULTS: In all 49 patients, concordant rate of both conventional and Heliprobe methods was 98% (48/49) and the discordant rate was 2% (1/49). Thirteen of 18 patients to whom biopsies were applied, were found to be HP positive on histologic results. And both Heliprobe method and conventional method classified 13 of 13 HP-positive patients and 5 of 5 HP-negative patients correctly (sensitivity 100%, specificity 100%, accuracy 100%). CONCLUSION: The Heliprobe method demonstrated the same diagnostic performance compared with the conventional method and was a simpler and more rapid technique.
Biopsy ; Breath Tests* ; Diagnosis* ; Dyspepsia ; Helicobacter pylori* ; Helicobacter* ; Humans ; Scintillation Counting ; Sensitivity and Specificity

Separation of Langerhans cells in epidermis of 16 healthy Korean individuals were performcd. Separation of Langerhans cells by density gradient centrifugation on a colloidal sillica(percoll) polyvinilpyrrolidone gradient. And autologous, allogeneic mixed skin cell leukocyte culture reaction was done with each fractionatcd cpidermal cell suspensions. Also lymphocytes, epidermal cells was cultured in media alone, respectively. The results was quantitated by the incorporation of H-thymidine by p-liquid scintillation counter. The densities of I angerhans cells within the epidermal cells, fraction-2 was most higher concentration (22.0+2.8%) and fraction-5 was most lower concentration (3.4+ l.9%). 2. In the comparison of the results of Langehans cells enriched and depleted population in autologous mixed skin cell leukocyte culture reaction, the former was higher than the latter on lymphocyte stimulatory capacity. There was significant differences(p<0.005) And also same as result in allogeneic mixed skin cell leukocyte culture reaction. 3. Langerhans cells enriched fraction in this study was more lymphocyte stimulatory capacity than depleted fraction in allogeneic mixed skin cell leukocyte culture(p<0.01~0.05). Ailogeneic mixed skin cell leukocyte culture reaction was more lymphocyte stimulatory capacity than the autologous(p<0.005~0.05).
Centrifugation, Density Gradient* ; Colloids* ; Epidermis ; Humans* ; Langerhans Cells* ; Leukocytes* ; Lymphocytes ; Scintillation Counting ; Silicon Dioxide* ; Skin* ; Suspensions

Hypoxic insult increases the level of extracellular glutamate, which leads to the influx of toxic Ca++ through the activation of N-methyl-D-aspartate(NMDA) receptors. The neuroprotective action of NMDA antagonist against hypoxic insult has been demonstrated in vitro. It has been demonstrated that the concentration of 50hydrox-ytryptamine(5-HT) also increased after ischemia in rat hippocampus. However, there is paucity of studies concerning the funtional relationships between the spontaneous release of 5-HT and NMDA receptor activity during hypoxia in vitro. Therefore, the present study was aimed to investigate whether hypoxia and/or NMDA was able to stimulate the release of 5-HT from the hypoxia-sensitive rat hippocampl slices.The hippocampus was obtained from the rat brain and sliced 400um thickness with manual chorpper. After 30 min's preincubation in the normal buffer, the slices were incubated for 20 min in a buffer containing 3H-5HT(0.1uM, 74uCi) for uptake, and washed. To measure the release of 3H-5-HT into the buffer, the incubation medium was drained off and refilled every ten minutes through a sequence of 14 tubes. Administration of NMDA or induction of hypoxia (gassing it with 95% N2/5% CO2) was done in the 6th and 7th tube, and APV was added 10 minutes prior to these manipulations. The radioactivities in each buffer and the tissue were counted using liquid scintillation counter and the results were expressed as a percentage of the total radioactivity. When slices were exposed to hypoxia for 20min, 3H-5-HT release was markedly decreased and a rebound release of 3H-5-HT was observed on the post-hypoxic period. NMDA(1mM) incereased 3H-5-HT release in the control group. NMDA also incereased rebound release of 3H-5-Htrelease. When 2-amino-5-hposphonovaleric acid (APV, 30uM or 60 uM) were added to the incubation media, NMDA-induced increase of 3H-5-HT release were blocked does-dependently. The rebound release of 3H-5-HT during post-hypoxic period was also blocked by APV. These results suggest that the spontaneous release of 3H-5HT decreases during hypoxic period, but 20min hypoxic exposure causes rebound increase of 3H-5-HT release during post-hypoxic period which is mediated by the increased activity of the NMDA receptor.
Animals ; Anoxia* ; Brain ; Glutamic Acid ; Hippocampus ; Ischemia ; N-Methylaspartate* ; Radioactivity ; Rats* ; Scintillation Counting ; Serotonin*

The effects of adenosine, adenosine A1 receptor antagonist (DPCPX), or NMDA receptor antagonist (APV) on the spontaneous release of (3H)-5-hydroxytryptamine ((3H)-5-HT) during normoxic/normoglycemic or hypoxic/hypoglycemic period were studied in the rat hippocampal slices. The hippocampus was obtained from the rat brain and sliced 400 mum thickness with the tissue slicer. After 30 min's preincubation in the normal buffer, the slices were incubated for 30 min in a buffer containing (3H)-5-HT (0.1 muM, 74 muCi/8 ml) for uptake, and washed. To measure the release of (3H)-5-HT into the buffer, the incubation medium was drained off and refilled every ten minutes through sequence of 14 tubes. Induction of glucose/oxygen deprivation (GOD; medium depleting glucose and gassed with 95% N2/5% CO2) was done in 6th and 7th tube. The radioactivities in each buffer and the tissue were counted using liquid scintillation counter and the results were expressed as a percentage of the total radioactivities. When slices were exposed to GOD for 20 mins, the spontaneous release of (3H)-5-HT was markedly increased and this increase of (3H)-5-HT release was blocked by adenosine (10 muM) or DL-2-amino-5-phosphonovaleric acid (APV; 30 muM). Adenosine A1 receptor specific antagonist, 8-cyclopentyl-1,3-dipropylxanthine (DPCPX) exacerbate GOD-induced increase of spontaneous release of (3H)-5-HT. These results suggest that Adenosine may play a role in the GOD-induced spontaneous release of (3H)-5-HT through adenosine A1 receptor activity.
Adenosine* ; Animals ; Brain ; Glucose ; Hippocampus ; N-Methylaspartate ; Radioactivity ; Rats* ; Receptor, Adenosine A1 ; Scintillation Counting

PURPOSE: A urea breath test (UBT) using C-14 or C-13 has been developed for identifying Helicobacter (H) pylori infection on the basis of urease production with release of labeled CO2. We investigated if the C-14 and C-13 UBT have the difference to reflect the presence and degree of H. pylori infection detected by gastroduodenoscopic biopsies (GBx) in the same patients. Materials and METHODS: Thirty eight patients (M:F=28:10, age 53.4+/-13.0 yrs) with upper gastrointestinal symptoms such as indigestion, gastric fullness or pain consecutively underwent C-14 UBT, GBx and C-13 UBT within one week before medications. For the C-14 UBT, a single breath sample was collected at 10 minutes after ingestion of C-14 urea (37 KBq) capsule and counting was done in a liquid scintillation counter for 1 minute, and the results were classified as positive (> or =200 dpm), intermediate (50~199 dpm) or negative (<50 dpm). For the C-13 UBT, the results were classified as positive (> or =2.5 permill) or negative (<2.5 permill). The results of GBx with Giemsa stain were graded 0 (normal) to 4 (diffuse) according to the distribution of H. pylori by the Wyatt method. We compared C-14 UBT and C-13 UBT results with GBx grade as a gold standard. RESULTS: The prevalence of H. pylori infection by GBx with Giemsa stain was 25/38 (65.8%). In the assessment of the presence of H. pylori infection, the C-14 UBT global performance yielded sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy of 92.0%, 92.3%, 95.8%, 91.7% and 92.1%, respectively. However, the C-13 UBT had sensitivity, specificity, PPV, NPV and accuracy of 96.0%, 84.6%, 92.3%, 91.7% and 92.1%, respectively. The more significant correlation in C-14 than C-13 UBT (r=0.948 vs r=0.819, p<0.001) was found between the value of UBT and the grade of distribution of H. pylori infection. CONCLUSION: We conclude that the diagnostic performance between C-14 and C-13 UBT to detect H. pylori infection is not significantly different, but the value of C-14 UBT more significantly reflects the degree of bacterial distribution.
Azure Stains ; Biopsy ; Breath Tests ; Dyspepsia ; Eating ; Helicobacter ; Helicobacter pylori ; Humans ; Organothiophosphorus Compounds ; Prevalence ; Scintillation Counting ; Sensitivity and Specificity ; Urea ; Urease

PURPOSE: Hippocampus contains interneurons where neuropeptide Y is located, but the connectivity of these has not been well studied. Neuropeptide Y may influence the serotonergic nervous system through the interneurons. Serotonergic nerve fibers pass through nearly all areas of the hippocampus. We investigate the effects of Neuropeptide Y on serotonin release from rat hippocampal slices for the better understanding of the effects of neuropeptide Y at the hippocampus. MATERIALS AND METHODS: The hippocampus was obtained from the male rat brain and sliced. The slices were incubated in a buffer containing 0.1 mM [3H]5-hydroxytryptamine (5-HT) for uptake. The release of 5-HT into the buffer during each 10 min period was measured and the radioactivities in each buffer and the tissue were counted using liquid scintillation counter and the results were expressed as a percentage of the total activity. After 50 min from the initiation, neuropeptide Y were administered at 6th and 7th 10 min period, respectively. The changes of 5-HT release were expressed as percent values compared to the 5th 10 min period. RESULTS: A steady release of 5-HT was observed up to 100 min after the rapid release during the first 40 min. The 5-HT release during 10 and 20 min of neuropeptide Y (10 6 M) treatment showed no significant change. CONCLUSIONS: The release of 5-HT was not changed by neuropeptide Y and this results suggest that neuropeptide Y does not influence the serotonergic nervous system through the interneurons.
Animals ; Brain ; Hippocampus* ; Humans ; Interneurons ; Male ; Nerve Fibers ; Nervous System ; Neuropeptide Y* ; Neuropeptides* ; Radioactivity ; Rats* ; Scintillation Counting ; Serotonin*

PURPOSE: The C-14 urea breath test (C-14 UBT) is the most specific noninvasive method to detect Helicobacter (H) pylori infection. We investigated if the C-14 UBT can reflect the presence and degree of H. pylori detected by gastroduodenoscopic biopsies (GBx). MATERIALS AND METHODS: One hundred fifty patients (M:F=83:67, age 48.6+/-11.2 yrs) underwent C-14 UBT, rapid urease test (CLO test) and GBx on the same day. For the C-14 UBT, a single breath sample was collected at 10 minutes after ingestion of C-14 urea (137 KBq) capsule and counting was done in a liquid scintillation counter for 1 minute, and the results were classified as positive ( 200 dpm), intermediate (50~199 dpm) or negative (<50 dpm). The results of CLO tests were classified as positive or negative according to color change. The results of GBx on giemsa stain were graded 0 (normal) to 4 (diffuse) according to the distribution of H. pylori by the Wyatt method. We compared C-14 UBT results with GBx grade as a gold standard. RESULTS: In the assessment of the presence of H. pylori infection, the C-14 UBT global performance yielded sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy of 92.5%, 88.4%, 97.1%, 88.4% and 91.3%, respectively. However, the CLO test had sensitivity, specificity, PPV, NPV and accuracy of 83.2%, 81.4%, 91.8%, 81.4% and 82.7%, respectively. The quantitative values of the C-14 UBT were 45+/-27 dpm in grade 0, 707+/-584 dpm in grade 1, 1558+/-584 dpm in grade 2, 1851+/-604 dpm in grade 3, and 2719+/-892 dpm in grade 4. A significant correlation (r=0.848, p<0.01) was found between C-14 UBT and the grade of distribution of H. pylori infection on GBx with giemsa stain. CONCLUSION: We conclude that the C-14 UBT is a highly accurate, simple and noninvasive method for the diagnosis of ongoing H. pylori infection and reflects the degree of bacterial distribution.
Azure Stains ; Biopsy ; Breath Tests* ; Diagnosis ; Eating ; Helicobacter pylori* ; Helicobacter* ; Humans ; Scintillation Counting ; Sensitivity and Specificity ; Urea* ; Urease

We established an in vitro experimental system using the following procedure. We first introduced tritium-labeled norepinephrine ([3H]-NE) into PC12 cells. The [3H]-NE incorporated-PC12 cells were stimulated by a high concentration (60 mM) of K+ buffer during 12 minutes. Then, we collected 100 microliter supernatant and counted the amount of [3H]-NE release from PC12 cells with a scintillation counter. After screening fungal, Streptomyces spp. or bacterial product using this experimental sytem, we obtained FS390 from Streptomyces spp. which inhibited [3H]-NE release from PC12 cells. FS390 also inhibits the release of ATP as a neurotransmitter of PC12 cells and rat cortical neurons. The inhibitory effect was seen even when the PC12 cells were treated with low K+ buffer containing ionomycin (1 micrometer) as an ionopore. This result suggests that the inhibitory action of FS390 on neurotransmitter release appeared after the influx of Ca2+.
Adenosine Triphosphate ; Animals ; Exocytosis ; Ionomycin ; Mass Screening* ; Neurons ; Neurotransmitter Agents* ; Norepinephrine ; PC12 Cells* ; Rats ; Scintillation Counting ; Streptomyces