Showing papers by "Chung-Ang University published in 1994"

Nitric oxide generation from streptozotocin.

Abstract: Streptozotocin (STZ), a diabetogenic agent, is thought to damage pancreatic beta-cells by activating immune mechanisms and by alkylating DNA. In the present study, we demonstrated that STZ can prod...

Cleavage of immunoglobulin G by excretory-secretory cathepsin S-like protease of Spirometra mansoni plerocercoid

Abstract: When immunoglobulin G (IgG) was incubated with Spirometra mansoni plerocercoid (sparganum), it was cleaved into Fab and Fc fragments. Fab/c fragments were also hydrolysed. The digestion was accelerated by dithiothreitol (DTT), indicating that cleavage of IgG heavy chain was due to a cysteine protease secreted into the medium. The responsible enzyme, of M(r) 27 (+/- 0.8) kDa, was purified by a series of thiopropyl affinity, Sephacryl S-300 HR and DEAE-anion exchange chromatographies, either from worm extracts or from excretory-secretory products (ESP). The purified, thiol-dependent protease showed an optimal activity at pH 5.7 with 0.1 M sodium acetate but was active over the pH range 4.5-8.0. Its activity was inhibited completely by 10(-5) M L-trans-epoxysuccinylleucylamido(4-guanidino) butane (E-64) and 1 mM iodoacetamide (IAA), but by only 53% using the specific cathepsin L inhibitor, Z-Phe-Phe-CHN2 (5 x 10(-5) M). Partial NH2-terminal amino acid sequence was Leu-Pro-Asp-Ser-Val-Asn-Trp-Arg-Glu-Gly-Ala-Val-Thr-Ala-Val which showed 80% homology to human cathepsin S. Immunoblot analysis showed that sera from infected patients exhibited IgE antibody reaction. It is proposed that cleavage of immunoglobulin by an excreted-secreted, cathepsin S-like, allergenic protease is a mechanism of immune evasion used by the sparganum.

Economic design of a variable sample size -chart

Abstract: An economic design model for an -chart which uses a variable sample size feature is developed in this paper. In a variable sample size control chart the sample size at each sampling time depends on the value of the previous sample statistic, whereas the sample size is set to be fixed constant in traditional control charts. In order to detect shifts quickly, the variable sample size chart takes a larger sample if there is any indication that the process is running in an out-of-control state and a smaller sample otherwise. for practical purposes only two possible sample sizes are considered. The objective of the econo,ic design is to find the optimal sampling interval, control limit and sample sizes to minimize the expected cost per unit operating time. The determination of the optimal design requires the computation of the averge number of samples and the average number of observations taken when the process is in control and out of control. The characteristics can be computed using the Markov chain proper...

Two vivax malaria cases detected in Korea

Abstract: On .lune and .truly 1994, two cases of vivax wl,Blaria were consecutively diagnosed at the Yongsan Hospital, Chung-Ang University in Seoul. The first patient was a soldier sewing in western parts of the demilitarized zone (DMZ) while the second case was a resident of a village near DMZ. Neither patients had history of being abroad. Republic of Korea (ROK) has been free of malaria since the mid-1970s except for imported cases. The two ivfn malaria cases, together with an additional patient detected in 1993, occurred in relatively small areas near DMZ. This necessitated an epidemiologic surveillance. When medical records and blood smears in the areas were examined, no other cases were found. Of 7,723 mosquitoes collected by a black light trap for ho nights in June, 7,066 (91.5%) were Anopheles sinensis. In order to evaluate a significance of the recent malaria occurrence, a surveillance system should be operated in the areas. key words: Indigenous malaria, PEasmonium uivox, Korea

Quantitative study on the relation between structural and functional properties of the hearts from three different mammals.

Abstract: The ultrastructural quantitative composition of left ventricular cardiac myocytes from isolated Langendorff-perfused hearts was studied in three different mammals (rabbit, guinea pig, and rat). Volume densities of mitochondria, myofibrils, and unspecified cytoplasm were determined using morphometry and were compared to functional parameters including left ventricular developed pressure (LVDP), contractility (dP/dt), heart rate, TTI (tension-time index, an index of oxygen consumption), and relative heart mass (H/B) obtained from these hearts. Each of the mammals was found to possess a very specific and characteristic quantitative composition of cardiac myocyte. Cardiac myocytes contained 26.8% mitochondria and 56.3% myofibrils in rabbits, 25.8% mitochondria and 60.9% myofibrils in guinea pigs, and 27.7% mitochondria and 58.1% myofibrils in rats. The LVDP, contractility, heart rate, and TTI were quite different among species. However, there were close correlations between the mitochondrial volume density and the LVDP (p < 0.05), and between the mitochondrial volume density and the TTI (p < 0.05), in any group of the animals. It is concluded that the mitochondrial volume density is a good indirect indicator of function of cardiac muscle related to oxidative capacity. © 1994 Wiley-Liss, Inc.

Sparganum infections in normal adult population and epileptic patients in Korea: a seroepidemiologic observation.

Abstract: A seroepidemiologic observation of anti-Spirometrc erinacei plerocercoid (sparganum) antibody (IgG) in serum was made in normal adult and epileptic patients in Korea from february, 1987 to September, 1990. Sera were tested by enzyme-linked immunosorbent assay (ELISA) for anti-sparganum antibody together with anti-Taenic soEiun metacestode, and anti-Parusonimus westermcni antibodies. Sera reacted positively to sparganum antigen only were considered. Positive rate for anti-sparganum antibody in 850 normal adults was 1.9% (standardized rate by provincial population was 1.7%). In 2,667 randomly selected patients of epilepsy at 28 local centers of the Changmi Club, positive rate was 2.5% (standardized rate: 2.3%). In both normal adult and patient groups, the higher antibody rates were observed in Kangwon and Chonnam Provinces. Positive rates were 10 times higher in male than in female in normal adults and 4.5 times in male epileptic patients. The rates were elevated especially with age over 30-year. odd ratio of the antibody was 1.32 which indicated an ambiguous etiologic factor for epilepsy Key words: Sparganum, sparganosis, seroepidemiology, epilepsy

Characterization of three neutral proteases of Spirometra mansoni plerocercoid

Abstract: In the pathogenesis of sparganosis, proteases have been considered to play important roles in tissue migration and parasite feeding. Several bands of proteolysis were observed when crude extracts of Spirometra mansoni plerocercoid (sparganum) were examined using gelatin substrate gel at neutral pH, of which two proteases of 198 and 104 kDa were purified by two chromatographic steps, and a 36 kDa protease was purified by gelatin-affinity and DEAE-anion exchange chromatography. All the purified proteases exhibited optimal activity at pH 7.5 and 0.1 M Tris-HCl. Proteolytic activities at 198 and 104 kDa were inhibited specifically by serine protease inhibitors and 4-(amidinophenyl)methanesulfonyl fluoride (APMSF, 0.5 mM) and N-alpha-p-tosyl-L-lysine chloromethyl ketone (TLCK, 1 mM), which strongly suggested that these two proteases were trypsin-like proteases. The activity of the 36 kDa protease was inhibited by N-tosyl-L-phenylalanine chloromethyl ketone (TPCK, 1 mM) and chymostatin (0.1 mM), and was potentiated in 10 mM Ca2+ which showed that the protease had a chymotrypsin-like property. All the proteases were Schiff (PAS) positive. Proteases of 198 and 104 kDa degraded collagen completely within 24 h. The 36 kDa enzyme cleaved human recombinant interferon-gamma (rIFN gamma) and bovine myelin basic protein. In addition, all the purified proteins elicited strong antibody responses in the infected patients.

Intraocular fascioliasis: a case report.

Abstract: We report the case of a 28-year-old male who had been ill with headache and motor weakness for a month and developed sudden pain and blindness of the right eye. During ophthalmoscopy, a worm was recognized penetrating the iris, occupying the anterior chamber for a brief period, returning back behind the iris, and leaving corneal edema with hyphyema. Enucleation was performed to prevent the worm's escape from the eye. The enucleated eye revealed areas of a focal degeneration of sclera and intraocular hemorrhage. Microscopic findings of an abrupt tissue defect and few inflammatory reactions in the uvea suggested very recent migration of a moving worm. The flatworm detected in the anterior chamber was identified to be a juvenile Fasciola sp. This case is presumed to be the first case of intraocular fascioliasis reported in the literature.

Non‐visualization versus normal appearance of cavernous arteries on selective internal pudendal pharmaco‐angiograms: comparison with Duplex scanning, cavernosal artery systolic occlusion pressure and penile brachial index

Abstract: OBJECTIVE To determine whether selective internal pudendal pharmaco-angiography (SIPA) is the most reliable diagnostic procedure for evaluating the function of the cavernosal arteries. PATIENTS AND METHODS Both sides of the selective internal pudendal pharmaco-angiogram taken in 35 patients (70 cases), whose history was suggestive of post-traumatic arteriogenic impotence, were evaluated separately and compared to the corresponding side using the penile brachial index (PBI), duplex scanning and cavernosal artery systolic occlusion pressure (CASOP). RESULTS There was no significant difference in the peak flow velocity and diameter changes of the cavernosal arteries on duplex scanning, in pressure differences between the brachial artery systolic pressure and the CASOP, and in the PBI between the group with a normal appearance on SIPA and the other where the cavernosal arteries were not visualized. There was no significant difference in the results of these functional evaluations between the normal group and cases where the cavernosal arteries were not visualized accompanied by a completely obstructed internal pudendal artery or common penile artery visible on SIPA. CONCLUSIONS This study is unable to confirm the value of SIPA in evaluating the function of the cavernosal arteries as it provides only anatomical information.

Modulation of large conductance calcium-activated K+ channel by membrane-delimited protein kinase and phosphatase activities.

Abstract: Large conductance Ca(2+)-activated K+ channel was identified and studied in excised inside-out membrane patches of freshly dispersed smooth muscle cells from rabbit gastric antrum. The current-voltage relationship of the single channel was linear from -80 to +80 mV of pipette voltage in which single channel conductance was 249 +/- 17.8 pS (n = 19) in symmetrical concentration of K+ (145 mM) across the patch. Activity of the channel (NPo) depended not only on cytoplasmic calcium concentration but also on membrane potential. MgATP increased NPo in a dose-dependent manner and Mg2+ was prerequisite for the effect. Okadaic acid (100 nM), inhibitor of protein phosphatases, increased NPo further in the presence of MgATP. Therefore, it would be concluded that activity of the calcium-activated K+ channel in gastric smooth muscle cells was controlled by phosphorylation state of the channel protein and the state is further modulated by membrane-delimited protein kinase and protein phosphatase activities.

Characterization of a cysteine proteinase from adult worms of Paragonimus westermani

Abstract: Paragonimus westermani, the lung fluke, is known to migrate to the pulmonary tissue of mammalian hosts and causes pathological changes in the lungs. An acidic thiol-dependent proteinase with a molecular weight of approximately 20,000 daltons was purified to homogeneity using ion-exchange chromatography and gel filtration chromatography. On SDS-PAGE, the molecular weight of the enzyme was 17,500 daltons. Isoelectric point was 6.45. The enzyme was similar to the acidic cysteine proteinase of vertebrates in the properties of pH 5.5 for at least two days when stored at 4 degrees C. The cysteine proteinase was capable of degrading collagen and hemoglobin. Sera of patients with paragonimiasis and mice infected with P. westermani reacted in immunoblots with the partially purified proteinase. This result suggested that the cysteine proteinase of P. westermani may play a role in migration in tissues, and in acquisition of nutrients by parasites from the host. It is also potentially an antigen for the serodiagnosis of paragonimiasis.

Constituents ofCrataegus pinnatifida var.psilosa leaves (II) —Flavonoids from BuOH fraction—

Abstract: The studies were carried out to evaluate the constituents in the leaves ofCrataegus pinnatifida var.psilosa (Rosaceae) continuously. From the BuOH fraction of the MeOH extract, four flavonoid compounds, hyperoside (1), vitexin (2), 2"-O-rhamnosylvitexin (3) and quercetin-3-O-α-L-rhamnopyranosyl-(1→6)-β-D-galactopyranoside (4) were isolated and identified on the basis of their physico-chemical properties and spectroscopic evidences by comparison with authentic samples.

Energy measurement of 50 MeV proton beam with a NaI(Tl) scintillator

Abstract: Energy measurement of 50 MeV proton beam produced on the AVF MC-50 Cyclotron was conducted using a detector telescope with a NaI(Tl) scintillator as an E counter. Protons of various energies, elastically and inelastically scattered from the 12 C target nucleus were measured at four different angles of 35°, 40°, 50° and 55°. We applied the chi-square method to determine the beam energy, which showed a well defined minimum chi-square corresponding to a beam energy of 49.6 ± 2.3 MeV at the 68% confidence level. Also the light output response of NaI(Tl) to proton energies between 31 and 44 MeV is linear within 0.5 MeV and is in good accord with the recent result of Romero et al. [Nucl. Instr. and Meth. A 301 (1991) 241].

An estimation method for the excess over the bocndaries in the sprt and its applications

Abstract: Since Wald developed the sequential probability ratio test, many studies have been done to approximate the characteristics of the test. One of the major efforts among them is to approximate the excess over the boundaries used in the test. In this paper the excess is approximated as a simple function of the parameter to be tested by using the condition of the test statistic immediately before the stopping time in normal and exponential cases. The use of the estimated excess shows good performances in estimating the operating characteristic function, the average sample number, and the probability mass function of the sarnple number. It also make it possible to determine the boundary values which can give the error probabilities close to the desired ones.

Infectivity of Paragonimus westermani developing in a final host to another final host

Abstract: In the definitive hosts, metacercariae of Parofonimn westermani excyst in host duodenum, penetrate intestinal wall, migrate peritoneal and thoracic cavities, and develop to sexual maturity in 8 weeks. This study was undertaken to examine the age of the maturing p. westernnni when their infectivity to the other definitive hosts was retained. On 3, 7, 10, 14,21 and 28 days after feeding the metacercariae to cats through a gastric tube, the developing worms were harvested. The juveniles of different age were fed again to other experimental cats. One to 12 weeks after the oral-transfer infections, the experimental cats were examined for establishment of infections. In the cats to which 3- day and 7-day old juveniles (grown up to 1.4 mm long) were fed, 31.4% and 22.6% of the transferred worms were found infected. The worms of 10-28 days old were not infective. Early maturing stages grown up to 7 days maintained their infectivity to the other definitive hosts. Key words: Pnrosoninur upestermani metacercariae, juvenile worm, transfer infectivity

Determination of the structure for polysubstituted flavonoid and 6-C-glucosyl flavonoids using13C-1H long range couplings

Abstract: A flavone glycoside was isolated from the leaves ofBetula platyphylla var.latifolia and chracterized as 4′,6-Dimethoxy-5-hydroxyflavone-7-O-β-D-glucoside(pectolinarigenin-7-O-β-D-glucopyranoside) by method of chemical and NMR spectral analysis.13C-1H long range coupling was confirmative for determination of its substituted position. In connection with this study, 6-C-Glucosylnalingenin and 6-C-Glucosylaromadendrin were confirmed its structures using this technique.

Generalized techniques of reducing torque ripples in BDCM drives

Abstract: In this paper, a new technique of reducing torque ripples in inverter fed brushless DC motor drives is presented. The developed technique allows the reduction of as many torque ripple components as switching angles per half cycle of the inverter. The switching angles are determined by solving the nonlinear equations of the problem using numerical techniques. Software programs are developed to analyze the technique and the simulated torque waveforms are compared. The developed technique is also implemented to provide experimental torque waveforms. It is demonstrated that the developed technique can reduce the torque ripples and improve the performance of the system. >

Image restoration using spectrum estimation

Abstract: A stochastic approach to image restoration is proposed by using various spectrum estimation techniques. In order to estimate the original image from the knowledge of observed image, the minimum mean square error filter or Wiener filter is known to be optimum in the sense of minimizing the mean square error. The optimality of Wiener filter, however, holds only when the power spectra of the original image and noise are given in addition to the transfer function of the imaging system. In practice, the information of the original image is generally not available. In the present paper additive noise is assumed to be white with known variance and the Wiener filter is implemented using various estimation techniques for the original spectrum. The proposed method shows significant improvement over the conventional methods, such as the Wiener filter using constant signal-to-noise power ratio, particularly for images with low signal-to-noise ratio.© (1994) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Level structure of doubly odd154Ho

Abstract: 154Ho was studied via141Pr(16O,3n) reaction at beam energy of 75 MeV. We found two new rotationally aligned bands made of neutron h9/2 and f7/2 orbitals coupled to a proton h11/2 orbital. As with several new high-spin states, up to I=20, the ground state band with odd parity starts to show anomalous signature splitting at I=13 in this doubly odd154Ho. The observed rotational bands in154Ho are quite consistent with the onset of collectivity which appears in general at neutron number of 87 in neutron-deficient rare-earth nuclei.

Effect of pretreatment with diltiazem on left ventricular function and intracellular calcium distribution in postischemic reperfused guinea-pig hearts.

Abstract: BACKGROUND It has been previously demonstrated that pretreatment with diltiazem preserves mitochondrial function during postischemic reperfusion. AIM The purpose of this study was to perform cytochemical and hemodynamical assessment to confirm this demonstration. METHODS Isolated Langendorff-perfused guinea-pig hearts received 10 min of diltiazem (7.5 microM) treatment, were subjected to 10 min of global ischemia and to 20 min of reperfusion. Left ventricular function was monitored by connecting a balloon to a pressure transducer. Intracellular calcium was precipitated with potassium pyroantimonate and examined with a transmission electron microscope. RESULTS Compared with the control and the ischemic hearts, the diltiazem-pretreated hearts showed a significant increase in the left ventricular developed pressure (LVDP), dP/dtmax (P < 0.01), and recovery rates of the LVDP (P < 0.01 versus ischemic hearts) and dP/dtmax (P < 0.05), and a decrease in the heart rate (P < 0.01). The left ventricular end-diastolic pressure (LVEDP) and leakage of creatine kinase were not significantly different. Calcium deposits were seen along the inner aspects of the sarcolemma and t-tubule membranes, and in the mitochondria of the control hearts. The number of these deposits was considerably reduced after ischemia. They reappeared principally in the mitochondria by reperfusion. In contrast, the calcium deposits reappeared along the sarcolemma, t-tubule membranes, and cell junctions, and in the mitochondria in the diltiazem-pretreated hearts. CONCLUSION These results suggest that pretreatment with diltiazem may improve cardiac function during postischemic reperfusion, probably in part by maintenance of sarcolemmal integrity rather than by mitochondrial buffering function.

Obtaining surface orientation of texture image using mathematical morphology

Abstract: In this paper, we present a new morphological approach to obtain a surface orientation using the variation of texture image caused by projective distortions. The perspective effect and the foreshortening are considered as the projective distortions. Under the assumption that the surface of texture image is plane, we apply the mathematical morphology in order to compute the 3D surface orientation. Centroids of texels can be obtained from the farthest texel to the nearest texel sequentially by recursive erosions, so the entire texture image is segmented into several sub-regions. We may compute a major axis of each sub-region with centroids and an average slope with all major axes. Intersections between the line perpendicular to the average slope and the major axes are obtained. Using the relations between the intersections and the size of structuring elements in each sub-region, we can compute the vanishing point. The entire region is rearranged using the major axes of sub-regions and the lines converging to the vanishing point. We can obtain the surface orientation by using the vanishing point and the perpendicular line. We have demonstrated experimental results with the artificial image and the natural images. In the experimental results, we have ascertained the proposed algorithm was more effective than the algorithm using the aggregation transform with the texel edge.© (1994) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.