Measurement of bone mineral in vivo: an improved method

The mineral content of bone can be determined by measuring the absorption by bone of a monochromatic, low-energy photon beam which originates in a radioactive source (iodine-125 at 27.3 kev or americium-241 at 59.6 kev). The intensity of the beam transmitted by the bone is measured by counting with a scintillation detector. Since the photon source and detector are well collimated, errors resulting from scattered radiation are reduced. From measurements of the intensity of the transmitted beam, made at intervals across the bone, the total mineral content of the bone can be determined. The results are accurate and reproducible to within about 3 percent.

Comparison of the Quantitative Values of C-14 and C-13 UBT to Reflect the Presence and Degree of Ongoing Helicobacter pylori Infection / 핵의학분자영상

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 ( 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.

Radiolocalização do linfonodo sentinela em portadores de carcinoma espinocelular da cavidade oral e orofaringe: resultados preliminares / Sentinel Lymph node radiolocalization in cancers of the oral cavity and oropharynx: preliminary results

Objetivos: Avaliar a eficácia e a utilidade do estudo por radiolocalização do linfonodo sentinela em portadores de carcinoma espinocelular de orofaringe e cavidade bucal. Foi estudado o comportamento radioativo do linfonodo sentinela no paciente (in vivo) e fora deste (ex vivo) e a histologia do linfonodo sentinela comparado com os achados histológicos do esvaziamento cervical ipsilateral. Métodos: Utilizou-se 12 pacientes com tumores de orofaringe e cavidade bucal tratados na Clinique Saint Augustin - Bordeaux - França no período de janeiro a dezembro de 2003. A radiolocalização do linfonodo sentinela foi realizada com injeção peritumoral de tecnécio 99m, análise no laboratório de cintilografia e utilização da sonda gama no per-operatório. Os linfonodos radiomarcados foram comparados por sua atividade radioativa in vivo e ex vivo e, com o restante do esvaziamento cervical, quanto à característica histopatológica. Resultados: Em relação à comparação do comportamento radioativo in vivo e ex vivo, existiram 15 zonas radiomarcadas e, entre estas, cinco zonas não coerentes in vivo e ex vivo. A comparação da histologia do linfonodo sentinela e o restante do esvaziamento cervical mostram coerência em nove casos e discordância em três. Conclusão: Os resultados sugerem que a técnica de radiolocalização de linfonodo sentinela em portadores de carcinomas espinocelulares de orofaringe e cavidade bucal é pouco eficaz tanto para determinar corretamente o linfonodo sentinela quanto para predizer o estado dos demais gânglios do esvaziamento cervical.

Expression of IRFs and iNOS in the Mouse Cornea with Pseudomonas Aeruginosa Keratitis

PURPOSE: To investigate the expression of IRF-1, IRF-7 and iNOS in the mice model of Pseudomonas aeruginosa keratitis. The enzymatic activity of iNOS and its expression were also investigated. METHODS: With western blot analysis, the protein expression of IRF-1, IRF-7 (at 24 hours), and iNOS (at 12 hours and 24 hours) were evaluated in the mouse model of P. aeruginosa keratitis. iNOS enzymatic activity was determined with a scintillation counter. IRF-1 and IRF-7 expression were localized with immunofluorescent labeling. The wounded control group was given the same corneal wound without bacterial inoculation, and the fellow eyes served as normal controls. RESULTS: Expression of IRF-1, IRF-7 and iNOS was highly upregulated in corneas with P. aeruginosa keratitis compared to normal or wounded corneas. iNOS enzymatic activity also was higher in infected than normal corneas. In wounded corneas, NOS2 expression and activity slightly increased at 12 hours after the infection. Intense IRF-1 immunopositivity was seen in the epithelial layer of infected corneas. Some corneal stromal cells and endothelial cells showed moderate positive labeling in infected corneas. IRF-7 showed intense labeling in the epithelial layer and endothelial cells of normal as well as infected corneas. Increased IRF-7 labeling was observed in epithelial cells in the ulcerated region of infected corneas. CONCLUSIONS: These results suggest that IRF-1, IRF-7 and iNOS may play a regulatory role in the immune responses and wound healing process in P. aeruginosa keratitis.

Screening of Low Molecular Metabolite, FS390 as an Inhibitor of Neurotransmitter Release from PC12 Cells / 대한해부학회지

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+.

Mineralization of 14C-carbofuran in soil under aerobic and anaerobic conditions

The mineralization of 14C-carbofuran in clay loam soil was determined during a three months laboratory incubation period under anaerobic and aerobic conditions. 14C-activity in solution was directly determined by liquid scintillation counting. Unextractable soil residues were determined by combustion. Evolution of 14CO2 increased with time and reached to 7.5% and 12.0% of the initial 14C-concentration, within 90 days in case of anaerobic and aerobic conditions, respectively. At that time, soil contained about 58% of the applied dose as extractable residues under anaerobic conditions and 59% under aerobic conditions. The unextractable pesticide residues were gradually increased with time and the highest binding capacity of about 5.3% and 13% in case of anaerobic and aerobic conditions, respectively were observed after 90 days of incubation. Chromatographic analysis of methanolic extracts revealed the presence of labelled carbofuran, carbofuran phenol and 3-hydroxycarbofuran as main products. Radiorespirometiy was used to evaluate the effect of carbofuran on soil microbial activity for 14 days. Both 3 and 9 mg carbofuran/kg soil depressed 14CO2 evolution from 14C-glucose and microbial activity was significantly inhibited especially in case of the high dose

Comparison of the Diagnostic Performance of 14C-urea Breath Test According to Counting Method for the Diagnosis of Helicobacter pylori Infection / 대한핵의학회잡지

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.

Interference of three weed extracts on uptake of nutrient in three different varieties of paddy through radio tracer techniques.

Interference of three dominant weed extracts viz., Ageratum conyzoides L., Melilotus indica All. and Parthenium hysterophorus L. were examined on seed germination, seedling growth, and nutrient uptake (32P and 65Zn) in three different varieties (PD-10, PD-12 and PB) of paddy (Oryza sativa L.). Among the three different varieties irrespective of weed extracts, PD-10 and PD-12 were resistant and PB was susceptible in terms of seed germination, radicle length and plumule dry weight; and PD-12 and PB were resistant and susceptible, respectively, in terms of plumule length and total seedling dry weight. A. conyzoides caused maximum reduction in seed germination and M. indica in seedling growth in different varieties of paddy. The weed extracts interfered in uptake of both 32P and 65Zn and there was a gradual decrease in uptake of both nutrients with increasing concentration of extracts in both root and shoot. The uptake of 32P and 65Zn was more inhibitory with the extracts of A. conyzoides and M. indica, respectively in different varieties. The inhibition in seed germination, seedling growth and nutrient uptake may be due to the presence of phenolics and other secondary metabolities. The phenolics such as gallic, vanillic, protocatechuic and p-hydroxybenzoic acids were identified from these weed extracts.

Comparison of the efficacy of biodegradable and non-biodegradable scintillation liquids on the counting of tritium- and [14C]-labeled compounds

The widespread use of H and 14C in research has generated a large volume of waste mixed with scintillation liquid, requiring an effective control and appropriate storage of liquid radioactive waste. In the present study, we compared the efficacy of three commercially available scintillation liquids, Optiphase HiSafe 3, Ultima-GoldÕ AB (biodegradable) and Insta-Gel-XF (non-biodegradable), in terms of [14C]-glucose and [ H]-thymidine counting efficiency. We also analyzed the effect of the relative amount of water (1.6 to 50 percent), radioisotope concentration (0.1 to 100 nCi/ml), pH (2 to 10) and color of the solutions (samples containing 0.1 to 1.0 mg/ml of Trypan blue) on the counting efficiency in the presence of these scintillation liquids. There were few significant differences in the efficiency of 14C and H counting obtained with biodegradable or non-biodegradable scintillation liquids. However, there was an 83 and 94 percent reduction in the efficiency of 14C and H counting, respectively, in samples colored with 1 mg/ml Trypan blue, but not with 0.1 mg/ml, independent of the scintillation liquid used. Considering the low cost of biodegradable scintillation cocktails and their efficacy, these results show that traditional hazardous scintillation fluids may be replaced with the new safe biodegradable fluids without impairment of H and 14C counting efficiency. The use of biodegradable scintillation cocktails minimizes both human and environmental exposure to hazardous solvents. In addition, some biodegradable scintillation liquids can be 40 percent less expensive than the traditional hazardous cocktails.

Characterization of the binding of delmopinol to salivary precipitates / Caracterização da associação de delmopinol com precipitados salivares

O objetivo do trabalho é determinar a quantidade de delmopinol associado com cada componente salivar de diferente peso molecular. Saliva não estimulada foi coletada com cinco indivíduos e misturada com delmopinol radioativo obtendo-se uma concentração final de 9,7 mM. As misturas de saliva e delmopinol foram analisadas com eletroforese tanto para o pelete como para o supernatante. Cada amostra foi analisada três vezes em eletroforese. A primeira foi corada com corante de prata. A segunda amostra foi preparada para fazer uma auto-radiografia. A terceira fileira foi cortada em pedaços iguais dissolvidos e analisados com cintilografia. O resultado de cintilografia demonstrou que um grande nível de radioatividade foi detectado em alto peso molecular (600-700 kDa). Em todas as amostras dos peletes foram encontradas grandes quantidades de delmopinol. O resultado da auto-radiografia confirmou que o delmopinol interagiu com proteínas de alto peso molecular (600-700 kDa)

Effect of Neuropeptide Y on the Serotonin Release in the Rat Hippocampus / 대한남성과학회지

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.

Can the C-14 Urea Breath Test Reflect the Extent and Degree of Ongoing Helicobacter pylori Infection? / 대한핵의학회잡지

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.

Scintillation Proximity Assay / 대한핵의학회잡지

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.

Involvement of Polyamine in Growth Hormine Secretion from the GH3 Cells / 대한내분비학회지

BACKGROUNDS: Polyamines are known to be essential for cell growth and differentiation. Recently, possible roles of the polyamine in signal transduction as neurotransmitter, modulator, or second messenger are suggested in many studies. Furthermore, it is widely studied that possible roles of polyamine are involved in the action of hormone. Thus, it was to investigate the effect of polyamines in the cell proliferation and secretion of GH from the GH cells. METHODS: Cells(5*10 cells/mL) were incubated for 3 days in DMEM containing test drugs and labeled with 20pCi/mL of [S]-methionine for 2 hr. Proteins secreted into the medium were separated by 13% SDS-gel electrophoresis, then autoradiography was performed to identify radiolabeled proteins. [S]-methionine labelled GH was identified by radioimmuno-precipitation. Total protein synthesis was determined from the radioactivity of the cell homogenate by liquid scintillation counter. The intracellular polyamine content was determined by HPLC. RESULTS: Externally added polyamines(putrescine, spermidine, spermine) induced cell proliferation in a dose-dependent manner at proper concentrations, specifically 50pM putrescine increased GH secretion, DFMO or MGBG, which is polyamine biosynthetic inhibitor, inhibited GH secretion in a dose-dependent fashion, In the cells treated with 20mM or 0.01mM MGBG, total protein synthesis were decreased only to 90 or 76% of the control levels and cell proliferation was also slightly inhibited. However the secretion of GH was severely blocked to 37% or 35% of the control. Hydrocortisone at 5 pM stimulated the secretion of GH to 153% of basal secretion, also doubled intracellular putrescine content. CONCLUSION: The present data show that externally added polyamines induced cell proliferation and GH secretion. Also, extemally added putrescine stimulated GH secretion significantly. GH secretion was inhibited by polyamine metabolic inhibitor in a dose-dependent manner and polyamine metabolic inhibitors, at proper concentrations, specifically blocked GH secretion without any significant influence on the total protein synthesis. The above results imply the involvement of polyamine in GH secretion.

Alteration of Phospholipase D Activity in the Rat Tissues by Irradiation / 대한치료방사선과학회지

PURPOSE: Phospholipase D (PLD) catalyzes the hydrolysis of phosphatidyl choline to phosphatidic acid (PA) and choline. Recently, PLD has been drawing much attentions and considered to be associated with cancer process since it is involved in cellular signal transduction. In this experiment, oleate-PLD activities were measured in various tissues of the living rats after whole body irradiation. MATERIAL AND METHODS: The reaction mixture for the PLD assay contained 0.1microCi 1,2-di[1-14C]palmitoyl phosphatidylcholine, 0.5mM phosphatidylcholine, 5mM sodium oleate, 0.2% taurodeoxycholate, 50mM HEPES buffer (pH 6.5), 10mM CaCl2, and 25mM KF. phosphatidic acid, the reaction product, was separated by TLC and its radioactivity was measured with a scintillation counter. The whole body irradiation was given to the female Wistar rats via Cobalt 60 Teletherapy with field size of 10cm x 10cm and an exposure of 2.7Gy per minute to the total doses of 10Gy and 25Gy. RESULTS: Among the tissues examined, PLD activity in lung was the highest one and was followed by kidney, skeletal muscle, brain, spleen, bone marrow, thymus, and liver. Upon irradiation, alteration of PLD activity was observed in thymus, spleen, lung, and bone marrow. Especially PLD activities of the spleen and thymus revealed the highest sensitivity toward gamma-ray with more than two times amplification in their activities. In contrast, the PLD activity of bone marrow appears to be reduced to nearly 30%. Irradiation effect was hardly detected in liver which showed the lowest PLD activity. CONCLUSION: The PLD activities affected most sensitively by the whole-body irradiation seem to be associated with organs involved in immunity and hematopoiesis. This observation strongly indicates that the PLD is closely related to the physiological function of these organs. Furthermore, radiation stress could offer an important means to explore the phenomena covering from cell proliferation to cell death on these organs.

Effect of Gamma Aminobutyric Acid on 5-Hydroxytryptamine Release Related to Sexual Function / 대한비뇨기과학회지

5-hydroxytryptamine (5-HT) containing pathways exert a inhibitory or facilitate effect on copulation. The administration of gamma aminobutyric acid (GABA) receptor agonists to the central nervous system in rats inhibits male copulatory behavior, whereas the administration of antagonists facilitates corpulatory behavior. GABA may influence the erection through dopaminergic pathway. But few about the effect of GABA on serotoninergic neuron are known. Raphe nuclei give rise to the major serotonergic innervation to the hippocampal formation and the GABAergic interneurons are located at the hippocampal formation also. This study was performed to investigate the influence of GABA, inhibitory interneuron, on the 5-HT release from rat hippocampal slices to understand the connection of the serotonergic neurons to GABAergic interneurons. The hippocampus was obtained from the male rat brain and sliced to a 400 Im thickness. After 30 minutes preincubation in the normal buffer, the slices were incubated for 20 minutes in a buffer containing 0.1 microM [3H]5-HT for uptake, and washed. After administration of GABA, the release of [3H] 5-HT into the buffer 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. Spontaneous release of [3H] 5-HT from the rat hippocampal slices decreased rapidly during the first 40 minutes of incubation. Through the rapid release of [3H] 5-HT, a steady state of [3H] 5-HT release was obtained from the 50 minutes of incubation. The value of released [3H] 5-HT after 50 minutes was expressed as percent of the value at 50 minutes. After administration of GABA (10(-4)M), the values (mean +/- SE) of released (3H)5-HT were 97.3 +/- 3.8% at 60 minutes and 91.2 +/- 3.4% at 70 minutes. The values of control group were 96.6 +/- 1.9% at 60 minutes and 89.6 +/- 2.3% at 70 minutes. There were no changes in the release of (3H)5-HT after administration of GABA. These results suggest that there are few connections between GABA and serotoninergic neurons and GABA does not influence the release of 5-HT in rat hippocampus.

Effect of adenosine on the release of (3H)-5-hydroxytryptamine during glucose/oxygen deprivation from rat hippocampal slices

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.

Variabilidad interobservadores al delimitar regiones de interés en gamagramas computarizados / Interobserver variability in RIO drawing in computerized scan processing

Antecedentes. En la actualidad, de los departamentos de medicina nuclear cuentan con cámaras de centelleo para gamagrafía computarizada. Para el radiorrenograma se adquieren 90 imágenes de 16 segundos cada una, se integran en una sola y sobre ella se trazan regiones de interés (RDI) dibujado el contorno de los riñones y de la vejiga, por medio de una palanca móvil ("joy stick"). El programa utliza la radiactividad de cada RDI para generar curvas de actividad/tiempo, y calcular el tiempo de máxima actividad renal (Tmax) y el tiempo que tarde el riñón en eliminar la mitad de esta radiactividad T½). El dibujo del contorno de órgano, al trazar las RDI, es el único paso en que interviene directamente el operador por lo que cabe la posibilidad de que los resultados dependan de su habilidad y experiencia, y por ende, que hubiera diferencias interoperadores que repercutieran en la interpretación clínica de los gamagramas. Objetivo. Establecer la variabilidad interoperadores de cuatro personas experimentadas en el trazado de RDI en imágenes renales. Material y métodos. Los cuatro operadores trazaron las RDI para obtener la Tmax Y T½ de 38 riñones de 20 pacientes (dos trasplantados). Se calculó el CV interoperadores de Tmax y T½ de los 38 riñones. Resultados. Globalmente hubo mayor variabilidad interobservadores en T½ que en Tmax. Cuatro riñones mostraron pequeñas diferencias interoperadores en Tmax y/o T½ pero suficientes para que discreparan sus clasificaciones de normal/retardado. La separación de los datos en tres grupos (T = Tmax y T½ normales; 2 = Tmax normal y T½ retardada; 3 = ambas retardadas) mostró que había diferencias intergrupos significativas en el CV interobservadores de la Tmax (Kruskal-Wallis p = 0.032) que obedecían a que la variabilidad fue mayor en el grupo 2 (6 de 11 riñones con CV >4 por ciento) que en los grupos 1 y 3 (ninguno con CV >4 por ciento). Conclusiones. 1. Las discrepancias interoperadores tuvieron repercusión sólo en algunos casos en que los parámetros estaban ligeramente retardados (8-9 min en Tmax, 15-20 min en T½). 2. No tenermos una explicación de por qué hubo mayor variabilidad interoperadores en Tmax de los riñones del grupo 2 (Tmax normal con T½ retardada). 3. Creemos que un estudio de la variabilidad interoperador de estas mismas cuatro personas puede aclarar algunas de las observaciones de este estudio

Involvement of N-methyl-D-aspartate Receptor in the Release of 5-hydroxytryptamine after Hypoxia from Rat Hippocampal Slices

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.

Separation of Human Epidermal Langerhans Cells by Density Gradient Centrifugation on a Colloidal Silica ( Percoll ) Gradient Method and Autologous , Allogeneic Mixed Skin Cell Leukocyte Culture Reactions / 대한피부과학회지

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).