Showing papers by "Chung-Ang University published in 1993"

Closed-End Country Funds and U.S. Market Sentiment, Mitsui Life Financial Research Center

Abstract: The premiums on closed-end country funds tend to move in tandem, but do not move together with premiums on domestic closed-end funds. After controlling for foreign market fundamentals, changes in the stock price of country funds co-move with U.S. market returns, but changes in their net asset values do not. An index of changes in country fund premiums explains cross-sectional stock returns in the U.S. market. Collectively, these findings suggest U.S. stock prices are affected by market-wide sentiments which are reflected in closed-end country fund premiums.

Discrete ordinates solutions for radiatively participating media in a cylindrical enclosure

Abstract: The radiative transfer equation is solved by the S-N discrete ordinates method in the two-dimensional r-z coordinates system. The walls of the enclosure are diffuse, and the participating medium absorbs, emits, and anisotropically scatters the radiative energy. Diffuse wall incidence, isothermal medium emission, and collimated incidence problems are considered. Effects of the scattering phase functions on average incident radiation and net radiative heat fluxes are studied. In addition, the effects of scattering albedo, optical thickness, and the wall emissivity are briefly discussed.

The liposome partitioning system for correlating biological activities of imidazolidine derivatives.

Abstract: The partitioning of 10 imidazolidines in various liposome/buffer systems (logK'm) has been determined and compared to partitioning in the n-octanol/buffer system (logP'). The logK'm, which was generally greater than the logP', increased or decreased upon the addition of dicetylphosphate (DCP) or stearylamine (STA), respectively, to dimyristoylphosphatidylcholine (DMPC) liposomes. Quantitative correlations of alpha 2-adrenergic potencies of imidazolidines have been made by regression analyses with logP', logK'm, binding affinity, and intrinsic activity. Both central and peripheral potencies correlated with logK'm but not with logP'. Multiple regressions yielded improved predictable quantification of these potencies. Thus, the liposomal membrane system shows certain advantages over the n-octanol/buffer system for the prediction of biological activities of the imidazolidines.

Optimization of hepatocyte attachment to microcarriers: Importance of oxygen.

Abstract: Many potential applications of primary hepatocytes cultured on microcarriers, such as an artificial liver or hepatocyte transplantation, would benefit from having a large number of hepatocytes attached to each microcarrier. In addition, the supply of primary hepatocytes is usually limited, so the efficient utilization of hepatocytes during attachment to microcarriers is necessary. Several physical parameters involved in the attachment process have been investigated, and the number of cells attached per microcarrier and the fraction of hepatocytes which attach have been quantitatively monitored. Variation of the partial pressure of gas phase oxygen in the incubation flask produced significant effects on the attachment of hepatocytes to microcarriers, with higher partial pressures of oxygen found to be necessary for attachment. In addition, variation of fluid depth and cell number, both of which influence the partial pressure of oxygen at the cell surface, affected hepatocyte attachment. The partial pressure of oxygen at the cell surface as a function of the physical parameters was analyzed using a simple one-dimensional theoretical model. Variations in the cell-to-microcarrier ratio used for incubation indicate that a compromise must be made in terms of maximizing the number of cells per microcarrier and the fraction of total hepatocytes which attach. The maximum number of hepatocytes per microcarrier obtained in this work was approximately 100. The best attachment fraction, defined as the ratio of the number of hepatocytes attached to the total number added to the incubation, was approximately 90%. © 1993 John Wiley & Sons, Inc.

Manning Criteria in Irritable Bowel Syndrome: Its Diagnostic Significance

Abstract: BACKGROUND Irritable bowel syndrome is one of the most commonly encountered gastrointestinal disorders, for which there are no established diagnostic criteria Thus, a diagnosis of IBS is made by exclusion of any organic diseases Recently, important attempts for the positive diagnosis of irritable bowel syndrome by questionnaire surveys of physical symptoms have been made We performed a questionnaire survey to evaluate the diagnostic value of the Manning criteria and to observe the major symptoms in irritable bowel syndrome METHODS A symptom questionnaire which consisted of 22 items, including 6 cardinal symptoms of the Manning criteria, were answered by 172 outpatients who had gastrointestinal complaints According to a final diagnosis based on independent clinical evaluation, all patients were categorized in three groups: irritable bowel syndrome group, nonulcer dyspepsia group and organic gastrointestinal disease group The results of the questionnaire were analyzed for each group RESULTS The sensitivity and specificity of the Manning criteria for the diagnosis of irritable bowel syndrome were 67% and 70% if three or more items were regarded as positive The mean score and overall frequency of the Manning criteria were significantly higher in irritable bowel syndrome group than in nonuclear dyspepsia (p < 001) or organic gastrointestinal disease group (p < 005) Among subgroups of the irritable bowel syndrome group, the pain-predominant subgroup showed a significantly higher score and overall frequency than the painless subgroup (p < 005) CONCLUSIONS The Manning criteria would be useful as a simple and reliable backup tool for the diagnosis of irritable bowel syndrome and seem to be more useful in pain-predominant subgroup More detailed history-taking should prevent unnecessary extensive investigations for the diagnosis of irritable bowel syndrome

Discrete ordinates solutions of nongray radiative transfer with diffusely reflecting walls

Abstract: Nongray gas radiation in a plane parallel slab bounded by gray, diffusely reflecting walls is studied using the discrete ordinates method. The spectral equation of transfer is averaged over a narrow wavenumber interval preserving the spectral correlation effect. The governing equations are derived by considering the history of multiple reflections between two reflecting wails. A closure approximation is applied so that only a finite number of reflections have to be explicitly included. The closure solutions express the physics of the problem to a very high degree and show relatively little error. Numerical solutions are obtained by applying a statistical narrow-band model for gas properties and a discrete ordinates code. The net radiative wail heat fluxes and the radiative source distributions are obtained for different temperature profiles. A zeroth-degree formulation, where no wall reflection is handled explicitly, is sufficient to predict the radiative transfer accurately for most cases considered, when compared with increasingly accurate solutions based on explicitly tracing a larger number of wail reflections without any closure approximation applied.

Fate of Clinically Insignificant Residual Fragments after Extracorporeal Shock Wave Lithotripsy with EDAP LT-01 Lithotripter

Abstract: The stone-free rate of 248 cases of clinically insignificant residual fragments (CIRF) was 32.7% by 1 month, 73.0% by 3 months, and 92.7% by 6 months of follow-up. The stone-free rate decreased but...

Institutional Change, Compensating Differentials, and Accident Risk in American Railroding, 1892–1945

Abstract: The labor markets in the railroad industry went through extensive institutional changes between 1890 and 1945. Federal laws increased railroad employers' liability for workplace accidents in several stages. Unions expanded to cover more occupations. The federal government set railroad wages during World War I and then mediated and arbitrated a large number of collective bargaining disputes between 1920 and 1945. We examine how these changes in institutions affected compensating differentials for fatal and nonfatal accident risk. The increasing role of unionization and government intervention coincided with a decline in the size of compensating differentials. Railroading was one of the more dangerous occupations at the turn of the century. More than 1,300 workers were killed each year in steam railway accidents between 1890 and 1929, reaching a peak of over 4,500 in 1907, and more than 100,000 workers were injured each year between 1911 and 1926. In the late nineteenth century injured railroad workers and their families received varying amounts of postaccident compensation based on common-law liability rules. Beginning in 1906, however, federal legislation altered the liability rules, leading to changes in the postaccident compensation of injured workers. Over the next few decades, moreover, the wage structure of the industry changed as a result of federal oversight and increased unionization. During World War I the federal government intervened to set wages for railroad workers, and it continued to play the role of arbitrator and mediator in settling wage disputes in the following period. At the same time, the growing strength of unions meant that by the 1920s wages in most railroad occupations were set by collective bargaining agreements.

Purification and partial characterization of cysteine proteinase from spirometra mansoni plerocercoids

Abstract: ABSTRAcr: Spirometra mansoni plerocercoids were dissected from the tissues of naturally infected snakes (Natrix trigrialateralia) Fresh plerocercoids were incubated in medium, and excretory-secretory products (E-S) were collected In addition, soluble proteins from lyophilized plerocercoids (10 mg/ml) were extracted in 01 M sodium acetate Proteinase activity was assayed with a synthetic fluorescent substrate, carbobenzoxy-phenylalanyl-arginyl-7-amino-4-trifluoromethylcoumarin Proteinase was isolated from plerocercoid extract or E-S by diethylaminoethyl trisacryl M ion-exchange chromatography and thiolpropyl-Sepharose affinity chromatography These separations resulted in a 122- (extract) and 156-fold (E-S) purification of proteinase Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of the purified materials revealed a 28-kDa band, consistent with the apparent native molecular weight (gel filtration chromatography) of approximately 35 kDa Proteinases purified from whole extracts and E-S were compared for various biochemical characteristics; inhibitor profiles indicated that activities from both sources are cysteine proteinases, they exhibited identical pH curves with optima at pH 55 and a 50% activity range at pH 47-80, they cleaved collagen chains to 3 identical products, and they showed only minor activity toward hemoglobin Further, the proteinase purified from plerocercoids was utilized in immunoblots with sera from sparganosis patients Antibody (IgG) from the infected patients, but not uninfected controls, recognized the cysteine proteinase, suggesting that this antigen may be useful in the serodiagnosis of Spirometra mansoni infection

PRIDE and Prejudice: The Economic Impacts of Growth Controls in Pasadena:

Abstract: In recent decades there has been a major revival, especially in the United States and Canada, in the adoption by municipalities of growth management controls and development ordinances, particularly in California (Glickfield and Levine 1991) and other fast-growing states with state growth management mandates (e.g. Oregon, Washington, Florida). Typically, these controls are justified as bringing a variety of community benefits such as reduced traffic congestion, lower taxes for infrastructure expenses, improved environmental quality, and preservation of traditional community atmosphere and spirit (Pincetl 1990). On the other hand, as Alonso (1973) argued, the hidden goal was often not to avoid the negative impacts of growth but to discriminate against newcomers, particularly poorer and/or minority newcomers. Another rationale for growth controls is based on the view that the cost of municipal services can rise very rapidly as populations grow larger and become more heterogeneous, and that this situation was made worse by the retrenchment in the 1980s of federal assistance for local infrastructure investments (Schneider 1990).

Sweet potato beta-amylase. Primary structure and identification of the active-site glutamyl residue.

Abstract: The complete amino acid sequence of a subunit of sweet potato β-amylase, a homotetramer, was established by sequence analysis of peptides obtained by digestions with Achromobacter protease I and Staphylococcus aureus V8 protease and by cyanogen bromide cleavage of the S-carboxyme-thylated subunit. The subunit of the enzyme is a single polypeptide consisting of 498 amino acid residues. It showed 50–60% identity in the amino acid sequence with those of β-amylases from soybean and barley, while it about 25% with those of three bacterial β-amylases deduced from the cDNA sequences. Sweet potato β-amylase was completely inactivated with 2,3-epoxypropyl α-d-[U-14C]glucopyranoside. Sequence analysis of the inactivated enzyme revealed that Glu187 was specifically esterified by the affinity labeling with the above reagent, proposing that Glu187 is a potent candidate involved directly in the catalysis with this plant β-amylase.

Stability and control of fuzzy dynamic systems via cell-state transitions in fuzzy hypercubes

Abstract: The objective of this paper is to provide fuzzy control designers with a generalized design tool for stable fuzzy logic controllers in an optimal sense. Given multiple sets of data disturbed by vagueness uncertainty, we generate the implicative rules that guarantee stability and robustness of closed-loop fuzzy dynamic systems. First, the mathematical basis of fuzzy hypercubes and fuzzy dynamic systems is rigorously studied by considering the membership conditions for perfect recall and the evidential combination for reliable reasoning. Second, the author suggests the cell-state transition method, which utilizes Hsu's cell-to-cell mapping concept. As a result, a generic and implementable design methodology for obtaining a fuzzy feedback gain K, a fuzzy hypercube, is provided and illustrated with simple examples. The designed rules or membership functions in K form the cell-state transitions that lead an initial state to the goal state globally. The cell-state transition approach provides flexibility in choosing different controller rule bases depending on optimal strategies. >

On developing an adaptive neural-fuzzy control system

Abstract: An adaptive neural-fuzzy control scheme for intelligent control is proposed. The control system consists of a fuzzy-neural controller (FNC) and model neural network (MNN). In the FNC, the antecedence and consequence of the fuzzy rule are constructed by a clustering method and a multilayer neural network. In the MNN, a multilayer neural network is utilized to identify an unknown controlled plant. The error backpropagation algorithm has been adopted as a learning technique. The effectiveness of the scheme is demonstrated by computer simulations of a cart-pole and a two-d.o.f. robot manipulator.

Seroepidemiological observation of Taenia solium cysticercosis in epileptic patients in Korea

Abstract: Prevalence survey of neurocysticercosis was made in a mixed epilepsy patients of Changmi Club in Korea. From February 1987 to July 1990, a total of 2,667 randomly selected patients at 27 local centers was tested for their serum levels of anti-Cysticercus antibody (IgG) by enzyme-linked immunosorbent assay. Positive rate of the antibody was 4.0% in the examined patients. The standardized antibody positive rate by provincial population was 3.1%. The rate was the highest in patients living in Cheju Do (8.4%). The patient age brackets of 0 approximately 9 years and over 50-year showed higher positive rates of the antibody. In 750 normal persons who checked up routine physical examination, the antibody positive rate was 2.1% (standardized rate was 1.8%). These seroepidemiological data disclosed for the first time the prevalence of cysticercosis in epileptic patients and in population.

Prevalence of Helicobacter pylori infection in patients with peptic ulcer diseases and non-ulcer dyspepsia.

Abstract: BACKGROUND Helicobacter pylori is known to be a cause of active chronic gastritis and has been proposed as an etiologic factor in the development of peptic ulcer disease, but controversy continues regarding the pathogenic importance and mechanism We examined the prevalence of H pylori infection in patients with peptic ulcers and non-ulcer dyspepsia METHOD 749 patients (373 with duodenal ulcer, 303 with gastric ulcer, 73 with non-ulcer dyspepsia) were included Endoscopic mucosal biopsies were done at antrum, duodenum, and, if present, ulcer margin The specimens were tested by Gram staining, Giemsa staining, culture, urease testing for identification of H pylori Antibody to H pylori was examined in 83 patient of these patients by ELISA, and the result was compared with the results of bacteriologic studies RESULT Prevalence of H pylori in antral mucosa was higher in patients with duodenal ulcers (815%) than in patients with gastric ulcer and non-ulcer dyspepsia (56% and 528%) (P < 005) Also in the duodenal mucosa of non-ulcer sites, and the ulcer margin of patients with duodenal ulcers, the detection rates (12% and 407%) were higher than those in the duodenal mucosa of patients with gastric ulcer and non-ulcer dyspepsia (7% and 8%)(p < 0005) Antibody to H pylori was detected in all patients with duodenal and gastric ulcers and non-ulcer dyspepsia who were tested for antibody In contrast, the detection rates of antibody in adult control and child control were 333% and 27% Among patients with antibody to H pylori, H pylori was detected in 857% of patients with duodenal ulcer, 625% of patients with gastric ulcers and 222% of patients with non-ulcer dyspepsia (p < 005) CONCLUSION These data suggest that H pylori is a possible pathogen for duodenal ulcer by duodenal colonization probably via gastric metaplasia Also the past or present infection of H pylori in antral mucosa may play a role at least partially in generation of upper gastrointestinal symptoms

Cyclosporin in the treatment of psoriasis

Abstract: The purpose of this study was to evaluate the efficacy of a low-dose cyclosporin therapy in psoriasis. In the multicentre study, carried out in Korea, 52 patients with moderate to severe psoriasis were treated with an initial dose of 2.5 mg/kg per day cyclosporin for 18 weeks. In 44 patients the dose was increased gradually up to 5 mg/kg per day according to the therapeutic response. Treatment success, defined as a reduction in PASI score by at least 66%, was achieved in 76.9% of patients. PASI scores reduced significantly from 20.0 to 5.4. Changes in systolic and diastolic blood pressure were not statistically significant. A 30% increase in serum creatinine in comparison with baseline was observed in five patients (9.6%) by the 18th week, but none of the patients showed an increase beyond the normal range. The overall assessments of efficacy and tolerability by both the investigators and the patients were mostly ‘good’ or ‘very good’. Our regimen of low-dose cyclosporin therapy (2.5 mg/kg per day initial...

Subband coding using human visual characteristics for image signals

Abstract: A subband coder which can be applied to various kinds of images such as HDTV (high-definition television), digital TV, and videophone is proposed using human visual characteristics. Data compression is achieved by the procedure based on human visual characteristics, where motion vectors in lower band are utilized to process components in higher band according to the degree of movement. Since the compression of the signal in higher band is accomplished by motion information, the proposed method shows good performance regardless of the degree of movement. Compared with the existing methods, which uniformly process all subblocks in the same subband, the quality of the image reconstructed by the proposed method is shown to be superior. >

Antral Helicobacter Pylori Infection, Hypergastrinemia and Peptic Ulcers: Effect of Eradicating the Organism

Abstract: BACKGROUND A randomized prospective study on the response of fasting serum gastrin concentrations in peptic ulcer patients was performed in order to test the hypothesis that H. pylori infection in the gastric antrum increases gastrin release, and to examine whether the high fasting serum gastrin concentrations respond to treatment that eradicates H. pylori. METHODS One hundred and twenty-seven patients with gastric or duodenal ulcer were included in this study. Patients were divided into three groups on the basis of antral H. pylori status and therapeutic modalities. The first group, 58 patients infected by H. pylori, was treated with metronidazole and tripotassium dicitrato bismuthate combined with ranitidine and mylanta. The second group, 40 patients also infected by H. Pylori, was treated with ranitidine and mylanta. The third group, 29 patients, free of H. pylori infection, was designed to evaluate the influence of H2-receptor antagonist on the change of gastrin. When ulcers were completely healed, changes of gastrin concentrations and H. pylori status were re-examined. RESULTS H. pylori was eradicated in all patients who have received antibacterial therapy in 4 weeks, and serum gastrin concentrations were significantly decreased after eradication of the organism both in gastric and in duodenal ulcer diseases. (Gastric ulcer: 129.3 +/- 47.0 pg/ml before and 63.7 +/- 21.6 pg/ml after treatment. Duodenal ulcer: 108.3 +/- 35.0 pg/ml and 66.5 +/- 21.9 pg/ml, respectively. Total: 112.7 +/- 38.2 pg/ml vs 66.0 +/- 21.6 pg/ml) (p 0.05). None of the patients who were initially H. pylori-negative has been reinfected during the period of the study, and their serum gastrin concentrations were not changed. (Gastric ulcer: 69.8 +/- 38.0 pg/ml. Total: 63.2 +/- 31.1 pg/ml. Duodenal ulcer: 55.1 +/- 17.6 pg/ml vs 55.8 +/- 13.8 pg/ml. Total: 63.2 +/- 31.1 pg/ml vs 63.4 +/- 30.0 pg/ml). Four- to six-week therapy of H2-receptor antagonist and antacid had no influence on serum gastrin concentrations. CONCLUSIONS On the basis of the above results, we confirmed that the chronic infection of H. pylori of gastric antrum in peptic ulcer patients causes increased release of serum gastrin, and eradication of the organism results in a significant fall in serum gastrin concentrations.

Eosinophilic granulopoiesis in human fetal liver.

Abstract: Eosinophilic granulopoiesis was investigated in human fetal liver during intrauterine life from 5 to 34 weeks of gestation. Eosinophilic granulocytes were observable for the first time at 5 weeks in the hepatic laminae and were frequently found in the late embryonic period around the large vessels and in the mesenchyme adjacent to the liver. Eosinophilic granulopoiesis increased gradually in the hepatic laminae (P < 0.01) after 20 weeks of gestation and in the portal areas (P < 0.05) after 16 weeks of gestation. The proportions of each cellular differentiation stage were relatively constant during fetal life, but a greater number of mature eosinophils were observed in the portal areas. Eosinophilic granulopoiesis was evident in all the hepatic tissue components, but developed more actively in portal areas than in hepatic laminae during intrauterine life. Eosinophilic granulopoiesis preceded both erythropoiesis and megakaryopoiesis in the human embryonic liver. Although the latter two occurred mainly in the hepatic laminae, eosinophilic granulopoiesis developed more actively in the portal areas, where it exhibited increasing activity along with the development of the component cells.

Information processing models for sleep staging

Abstract: Three different methods of automated sleep staging are described and compared in the paper. The interesting aspect of the comparison is that the inputs to the three different information processing models (an expert system, a belief automaton, and a neural network) are the outputs of the same fronted processor that excerts EEG features. We found out that the level of man-machine agreement is very similar among the systems (around 85%) approaching the level of agreement required among human experts. However, the similarity of performance in such a diversified set of approaches points out the need for enhancing the accuracy of the first level of analysis (EEG feature extraction).

Antigenic protein fractions of Metagonimus yokogawai reacting with patient sera.

Abstract: Antibody test is sometimes necessary for the diagnosis of acute human metagonimiasis because eggs may not be detected in stool. The antibody test (ELISA) was evaluated for its significance by reacting human sera from clinically diagnosed metagonimiasis, fascioliasis, clonorchiasis and paragonimiasis with 4 crude extracts of Metagonimus yokogawai (metacercariae), adults of Fasciola hepatica, Clonorchis sinensis and Paragonimus westermani. By ELISA, 10 of 11 metagonimiasis sera showed the highest absorbance (abs.) to the homologous antigen. Cross reactions to M. yokogawai antigen occurred most frequently in clonorchiasis sera. The antigenic protein fractions in M. yokogawai metacercarial extract were observed by SDS-PAGE/immunoblot using patients and control sera together with experimental cat sera. Out of 14 protein bands in the extract, 11 bands were reacting. Cross reacting bands to other trematodiasis sera were frequently observed. Of the reacting bands, 66 and 22 kDa proteins were recognized as specific for metagonimiasis.

An automated rule design of fuzzy logic controllers for uncertain dynamic systems

Abstract: The author investigates a systematic design procedure for automated rule generation for fuzzy-logic-based controllers of uncertain dynamic systems such as an engine dynamic model. Automated rule generation means autonomous clustering or collection of meaningful transitional relations from one conditional subspace to another. During the design procedure, optimal control strategies such as minimum squared error, near minimum time, minimum energy, or combined performed criteria are considered. Fuzzy feedback control systems designed by the cell-state transition method have the properties of closed-loop stability, robustness under parameter variations, and a certain degree of optimality. The main advantage of the approach is that reliability can potentially be increased even if a large grain of uncertainty is involved within the control system under consideration. A numerical example is shown in which the strategic fuzzy controller design is applied to a highly nonlinear model of engine idle-speed control. >

Combined digital zooming and digital effects system utilizing CCD signal characteristics

Abstract: An image processing system for digital zooming and digital effects is proposed. This system directly processes the CCD (charge coupled device) signal without separating it into luminance and chrominance signals, based on the characteristics of the color filter array in the CCD. By using the proposed color signal processing method, and efficient and high-quality digital zooming system is obtained. Various special effect functions are included in the system by adding simple controls for the addresses of the accompanied image buffers. The digital zooming can magnify the real-time dynamic images up to 4 times by 25 discrete steps. The digital effects unit achieves various visual effects by controlling the accompanied image buffers. To realize the proposed system, approximately 270000 transistors are integrated in a single chip VLSI by using 0.8 mu m double metal CMOS technology. >

Characterization of a peroxidase in excretory-secretory product of adult Paragonimus westermani.

Abstract: When activity of peroxidase in adult Paragonimus westermani was monitored using o-dianisidine and H2O2 as substrates, its specific activity was 1.5 times higher in excretory-secretory product (ESP) than in crude extract. The enzyme was purified by two purification steps of Sephacryl S-300 Superfine gel permeation and DEAE-Trisacryl M anion exchange chromatographies. Its activity increased 16.9 fold with 32.3% recovery. The enzyme was inhibited totally by 1 millimoles of dithiothreitol (DTT), 2-mercaptoethanol and azide. Molecular mass was 16 kDa in reducing SDS-polyacrylamide gel electrophoresis (PAGE) or 19 kDa in TSK-Blue gel filtration high performance liquid chromatography (HPLC), respectively. Special staining for peroxidase by diaminobenzidine on SDS-PAGE confirmed the activity. The peroxidase was less reactive to a paragonimiasis serum when observed by SDS-PAGE/immunoblot. In addition, specific activities of superoxide dismutase (SOD) and catalase were also identified in the ESP. High activities of these antioxidant enzymes in ESP indicate that they are parts of defense mechanisms against reactive oxygen intermediates from host.

Applicability of ABC-ELISA and protein A-ELISA in serological diagnosis of cysticercosis.

Abstract: Specific antibody test in serum and cerebrospinal fluid (CSF) is still the main mode of serological diagnosis of cysticercosis. Of different techniques of antibody test, enzyme-linked immunosorbent assay (micro-ELISA) has widely been applied. This study was undertaken to observe whether diagnostic capability can be improved by applying more sensitive techniques such as Protein A-ELISA and avidin biotin complex ELISA (ABC-ELISA). When evaluated using 115 sera of human cysticercosis, the antibody positive rates were not significantly improved in Protein A-ELISA (82.6%) and in ABC-ELISA (86.1%) than in micro-ELISA (81.7%). The specificities, evaluated in 165 sera from other diseases and normal controls, were significantly improved (88.5% by micro-ELISA, 93.3% by Protein A-ELISA and 93.8% by ABC-ELISA). Antibody levels (absorbance, abs.) in individual serum were correlated well (r = 0.83-0.86) each other. An actual benefit of Protein A-ELISA and ABC-ELISA was that they needed smaller amount of test sample.

Histopathologic and ultrastructural findings of photocoagulation lesions produced by transpupillary diode laser in the rabbit retina

Abstract: Transpupillary retinal photocoagulations were performed on ten eyes of five pigmented rabbits using a diode laser (Nidek Co., LTD, Aichi, Japan) emitting infrared radiation at 800 nm wavelength. A histological and an ultrastructural study on the treated eyes were done at 1, 3, 5, and 7 days after retinal photocoagulations. The purpose of this study was to observe the sequential changes in the retina and the choroid following transpupillary diode laser retinal photocoagulations at the parameters of laser power which produced a grayish white retinal discoloration with distinct white center. It seemed that the lesion was grade 3 retinal photocoagulation by Tso et al's classification. It appeared that the parameters necessary to produce grade 3 photocoagulation lesions were 160 mW power, and 0.2 second duration at 200 microns size. In general, with an agreement to other reports, histologic study of the diode laser lesions showed that the outer retina was damaged more severely than the inner retina. However, on day 1 after laser treatment, the alterations were more profound in the inner retina than in the outer retina and an occasional swelling of the axons in the nerve fiber layer was observed on the ultrastructural study. The results observed have not been found in other previous studies and suggest that the inner retina might be injured directly by 800 nm wavelength diode laser radiations. Thus we could conclude that 800 nm wavelength diode radiation might be absorbed by melanin pigment and also by other chromophores contained in inner retinal tissues. Further studies must follow to verify the laser-tissue interactions in diode laser retinal photocoagulations.

G- and D-cell populations, serum and tissue concentrations of gastrin and somatostatin in patients with peptic ulcer diseases.

Abstract: BACKGROUND Gastric acid is the most important pathophysiologic determinant in the development of peptic ulcer diseases, and gastrin and somatostatin are believed to be physiologic hormonal regulators in gastric acid secretion. The aim of this study is to investigate patterns of these peptides, both in serum and in tissue, and to correlate with numbers of their secretory cells in the antral and the duodenal bulb mucosa. METHODS The study population was made up of 256 patients with peptic ulcer (duodenal ulcer, 127; gastric ulcer, 74) and 55 patients with non-ulcer control subjects. Serum and mucosal concentrations of G17, G34 and somatostatin were measured by radioimmunoassay technique and peptides producing cells were identified immunohistochemically using peroxidase-antiperoxidase staining technique. RESULTS Serum G17 concentration was significantly decreased in duodenal ulcer patients (93.4 +/- 36.0 pg/ml) and G34 were more than twice as high as G17 both in patients with gastric and duodenal ulcer (210.6 +/- 50.6 pg/ml and 202.7 +/- 48.1 pg/ml vs 103.8 +/- 41.8 pg/ml and 93.4 +/- 36.0 pg/ml). Antral G17 (19.9 +/- 14.8 mcg/g, tissue) and G34 (26.6 +/- 18.5 mcg/g, tissue) were increased in duodenal ulcer patients and duodenal G17 (12.5 +/- 9.5 mcg/g. tissue in Gu and 8.5 +/- 7.4 mcg/g. tissue in DU) and G34 (15.7 +/- 12.6 mcg/g. tissue in GU and 13.9 +/- 12.0 mcg/g. tissue in DU) concentrations were found to be increased in both gastric and duodenal ulcer patients than in non-ulcer subjects (G17: 5.3 +/- 4.9 mcg/g. tissue. G34: 6.5 +/- 4.4 mcg/g. tissue). Only the antral somatostatin concentration was significantly increased in duodenal ulcer patients (5.3 +/- 5.9 mcg/g. tissue). Numbers of the antral G- and D-cell were lowest in GU patients (48.1 +/- 47.4 and 7.9 +/- 12.3) and numbers of both cells decreased proportionately with the severity of atrophic gastritis and/or intestinal metaplasia of the gastric mucosa. D/G cell ratio between non-ulcer subjects and DU patients was similar (1:4 and 1:5) but slightly increased in GU patients (1:7). There was no correlation between numbers of each peptide-producing cells and serum or mucosal concentration of gastrin and somatostatin. CONCLUSIONS Patients with duodenal ulcer had decreased level of serum G17 in the fasting state while mucosal concentrations of G17 and G34 were increased in the antrum and the duodenal bulb. Patients with gastric ulcer had increased levels of G17 and G34 only in the duodenal bulb mucosa. Only the antral somatostatin concentration was significantly increased in duodenal ulcer patients. Patients with gastric ulcer had lowest numbers of G- and D-cells in the antrum and numbers of both cells decreased proportionately with the degree of chronic atrophic gastritis and/or intestinal metaplasia of the gastric antrum. Numbers of G- and D-cells were not correlated with the serum or mucosal concentrations of each peptide.