Showing papers by "Yonsei University published in 1986"

A brain syndrome associated with delayed neuropsychiatric sequelae following acute carbon monoxide intoxication.

Abstract: A summary of clinical data is presented on 34 men and 52 women patients with brain syndrome associated with delayed neuropsychiatric sequelae following acute carbon monoxide intoxication. Their ages ranged from 34 to 82 years, with peak incidence in the sixth and seventh decade. Possible etiological factors were age, duration of unconsciousness on acute intoxication, and previous physical illness. The onset was relatively sudden after the apparent clear period which ranged from 2 to 40 days (mean 22.5 days). The most frequent symptoms were apathy, dull facial expressions, dementia, such as amnesia and disorientation, hypokinesia, mutism, irritable distractibility, urinary and/or fecal incontinence, gait disturbance and abnormal neurological signs and reflexes. EEG was abnormal in 33 of the 57 cases (58%). Of 27 patients who were given a computed tomographic brain scan, 15 patients were abnormal. The prognosis was relatively good in the follow-up study of 56 patients. Only age was related to a better prognosis.

Non-Lambertian Effects on Remote Sensing of Surface Reflectance and Vegetation Index

Abstract: This paper discusses the effects of non-Lambertian reflection from a homogeneous surface on remote sensing of the surface reflectance and vegetation index from a satellite. Remote measurement of the surface characteristics is perturbed by atmospheric scattering of sun light. This scattering tends to smooth the angular dependence of non-Lambertian surface reflectances, an effect that is not present in the case of Lambertian surfaces. This effect is calculated to test the validity of a Lambertian assumption used in remote sensing. For the three types of vegetations considered in this study, the assumption of Lambertian surface can be used satisfactorily in the derivation of surface reflectance from remotely measured radiance for a view angle outside the backscattering region. Within the backscattering region, however, the use of the assumption can result in a considerable error in the derived surface reflectance. Accuracy also deteriorates with increasing solar zenith angle. The angular distribution of the surface reflectance derived from remote measurements is smoother than that at the surface. The effect of surface non-Lambertianity on remote sensing of vegetation index is very weak. Since the effect is similar in the visible and near infrared part of the solar spectrum for the vegetations treated in this study, it is canceled in deriving the vegetation index. The effect of the diffuse skylight on surface reflectance measurements at ground level is also discussed.

Two cases of human infection by Echinostoma cinetorchis

Abstract: Eggs of Echinostoma sp. were found from two patients who were hospitalized between Oct. and Dec. 1985. Single dose of 10 mg/kg of praziquantel was prescribed to each patient and after purgation with magnesium salt seven and two adult worms of Echinostoma cinetorchis in respect were recovered from patients. The first case was a 54-year-old male residing at Chungju city in Chungbuk province. He was hospitalized because of severe weight loss and frequent urination. The second case was a 71-year-old male residing at Chungsun-kun in Kangwon province, and hospitalized due to suspected lung cancer. The average size of the eggs found in the stools was 98 x 63 micrometer (the first case) and 100 x 67 micrometer (the second case) respectively, and total nine worms collected were identified as E. cinetorchis.

[Experimental and epidemiological studies on the life cycle of Echinostoma hortense Asada, 1926 (Trematoda: Echinostomatidae)]

Abstract: Recently there have been some reports on human infections of Echinostoma hortense in Korea It was found that a few species of freshwater fishes were playing the role of the second intermediate host of E hortense However, molluscan intermediate host has not been identified yet in Korea The present study aimed to establish the life cycle of E hortense in laboratory Experimental studies such as egg production from the rat, development of the eggs in vitro, exposure of miracidia to freshwater snails, shedding pattern of cercariae from infected snails, morphology of cercariae, cercarial infection to the second intermediate host and infection of metacercariae to the difinitive hosts were done In addition, epidemiological surveys on the infection status in inhabitants and house rats, and on the natural infection of larval echinostomes in the snails and fishes were carried out along the South Hangang-river The results obtained were as follows: The eggs deposited from adults in physiological saline were cultivated at room temperature (20-24C) The miracidia were firstly observed on 8 days after cultivation, and 855 per cent of the eggs contained the mature miracidia on 11 days after cultivation More than 90 per cent formed the miracidia when cultivated at temperature 22-27C Hatching of the miracidia began on 12 days after cultivation and continued for a week The size of the miracidia was 1030 x 514 micrometer in average The motility of miracidia were active up to 8 hours after shedding, but they were all dead within 10 hours after shedding A freshwater snail, Radix auricularia coreana was cultivated in aquaria A hatched F1 snails from the egg masses were exposed to 20 miracidia respectively Escape of cercariae started on 15 days after infection Radix auricularia coreana was experimentally identified as the first intermediate host of E hortense in Korea Cercarial shedding started on 15-20 days after infection by snail, continued for about 10 days (88 days in average) Infected snails were dead within 32 days after the miracidial infection About 1,335 cercariae (328-1,994) per snail were shed in its life, and 119 cercariae in average per snail per day were shed The cercariae were motile for more than 24 hours, and then squirming at the bottom until death The body and tail sizes of cercariae were 356 x 186 micrometer and 510 x 68 micrometer in average, respectively The rediae parasitized in the snail hosts were found mainly around the pericardial regions, and their size was 1,575 x 258 micrometer in average The numbers of developing cercariae in a mature redia were 14 in average (7-20 in range) The numbers of rediae in a snail were 102 in average on 15 days after miracidial infection and 221 in average on 28 days Three uninfected Misgurnus anguillicaudatus, less than 65 cm long were used in for the cercaria1 infection They were all exposed with 755 cercariae, and examined at 5-day intervals starting from 10 days after infection All the fihes were infected with metacercariae of E hortense and a total of 275 was found infected (364 per cent) The metacercariae were fed to rats and the adult worms were obtained on 15 days after infection The infected rats began to deposit the eggs on 11 days after infection The number of eggs deposited per day per worm (EPD/worm) was 400-500 on 3 weeks after infection and was increased to 1,000-1,500 on 4 to 17 weeks, then decreased to 800 on 2l weeks after infection A total of 745 stool specimens collected from 576 male and 169 female residents of 8 different villages along South Hangang basin was examined Out of 745 specimens, the eggs of Echinostoma sp were found in 2 cases (03 per cent) Of 34 house rats one showed egg-positive (29 per cent) Total 971 Radix auricularia coreana collected from 7 sampling stations were examined for shedding of cercariae Three snails (03 per cent) shed the cercariae of E hortense A total of 119 out of 542 freshwater fishes (220 per cent) had the metacercariae of E hortense The fishes parasitized with the metacercariae were 4 out of 14 examined species The infection rate of 4 species were 341 per cent (106 out of 311) in Misgurnus anguillicaudatus, 304 per cent 7 out of 23) in Misgurnus mizolepis, 43 per cent (2 out of 46) in Moroco oxycephalus and 222 per cent (4 out of 18) in Odontobutis obscura interrupta In summarizing the above results, the first intermediate host of E hortense was found as Radix auricularia coreana in Korea Also it took about 46 days for the shortest completion of a life cycle of E hortense in summer; that is, 10 days for miracidial development in eggs, 15 days for cercarial development in the snail, about 10 days for metacercarial development in the second intermediate hosts, 11 days for the maturation as the adults in the definitive hosts The natural infection rates of E hortense in the intermediate hosts were relatively high but those in the definitive hosts were low in the middle areas of South Hangang basin

ELISA of paragonimiasis in cat by crude and purified antigens of Paragonimus westermani

Abstract: Enzyme-linked immunosorbent assay (ELISA) using crude and affinity-purified antigens of adult worms of Paragonimus westermani was performed for infected cat sera with different worm burden, from preinfection to 18th week after infection. Crude antigen was used with supernatant of homogenated worms by freezing-thawing method, and the supernate was centrifuged for l hour at 10,000 rpm at 4C. Affinity-purified antigen (antibody-bound antigen) was prepared from fractions (bound and unbound) of crude antigen by affinity chromatography on CNBr-activated sepharose 4B, and IgG as a ligand was prepared from paragonimiasis cat serum (6 months infected) obtained by ammonium sulfate (40-45 per cent saturated) precipitation method. By SDS-PAGE, crude antigen showed 22 polypeptide fractions while purified antigen showed 4 fractions: 36, 400, 34,700,27,600 and 11,500 in molecular weights. All cats were divided into five groups(G1-G5) by different worm burdens. The mean of recovered worms (+/-SD) and the number of cats in each group are as follows:G1, 2 worms(0) and 4 cats; G2, 4.75(+/-0.66) and eight; G3, 10.75(+/-1.92) and four; G4, 25.20(+/-3.43) and five; G5, 48(+/-12.63) and five cats. The results were summarized as follows: The antibody levels(OD value) increased by worm burden in G1 to G4 generally. However, individual antibody levels were not exactly related with worm burden in all groups, especially there was a wide difference in G4 and G5. These results suggested that the worm burden in G4 (about 20 - 30 worms) is enough to produce antibody maximum in cats of 2~3 kg weight. The antibody levels increased significantly (p<0.05) compared to control sera at the 3rd week in G1 and G2, at the 2nd week in G3, and at the 1st week in G4 and G5. Especially in the 4th week, OD value increased more in G1(p<0.001) and in G2 to G5(p<0.01). In the pattern of antibody levels by ELISA in each group, OD in G1 increased to the 18th week continuously, in G2 OD was maintained same after the 16th week, but in G3 it decresed after the 16th week, and it was maintained same in G4 and G5 after the 14th week. The antibody levels by ELISA with the affinity-purified antigen were higher than those with crude antigen in all groups generally. Especially, the difference of OD values between two antigens was larger from the 4th to the 10th week. In G1 and G2 OD with purified antigen was higher than that with crude one to the 18th week. It was also higher in G3 than that with crude antigen to the 16th week and OD of G4 and G5 were higher before the 14th week than that with crude antigen, however became lower at the 16th week. Consequently, the antibody level in ELISA with affinity-purified antigen was more sensitive at the early weeks after infection and in light infection groups than that with crude antigen.

Subcorneal pustular dermatosis treated with phototherapy.

Abstract: A 12-year-old boy had a 5-year history of recurrent generalized dermatoses with scales, crusts, and pustules. Histologic findings showed subcorneal blisters filled with polymorphonuclear leukocytes typical of subcorneal pustular dermatosis. Dapsone and prednisolone with a topical fluocinolone acetonide did not produce improvement. The skin lesions cleared completely after 11 exposures of UV-B three times a week. After 8 months of follow-up, there has been no recurrence.

Gold and Silver Ores from the Geumwang Mine in South Korea and Their Mineralization

Abstract: Gold and silver bearing quartz veins of the Geumwang mine in South Korea occur in Cretaceous granite altered hydrothermally. Ores from the mine are exceptionally silver rich as the Korean type gold deposit. The ore minerals occur in two or three sulfide bands formed at early to middle stages and a sulfosalt band at the late stage of mineralization. Electrum and silver minerals of polybasite, pyrargyrite and argentian tetrahedrite appears in sulfide band or stringer consisting of pyrite, arsenopyrite, galena, sphalerite, chalcopyrite and quartz in the vein. Also silver-antimony sulfosalt minerals such as pyrargyrite, polybasite, miargyrite, diaphorite and argentian tetrahedrite with native silver occur as a band in central portion of the quartz vein in association with some amounts of pyrite, sphalerite, arsenopyrite and quartz. Composition of electrum is 48.4 to 52.7 wt% Ag (63.0 to 67.4 at% Ag). Meanwhile sphalerite has 2.2 to 4.2 mole% Fes. Homogenization temperatures of fluid inclusion (two phases) in quartz of the sulfide band are from 183•‹to 310•Ž(240•Ž in average) with a peak at 240•Ž, commonly 220•‹to 270•Ž. The ore mineralogy suggests that temperature (T) and sulfur fugacity (fs2) of the formation of the sulfide and sulfosalt bands are estimated as T: 190•‹to 240•Ž, fs2: 10-15.5 to 10-13.5 atm, and T: 130•‹to 170•Ž, fs2: 10-19.5 to 10-110 atm, respectively. Such low temperature and low sulfur fugacity mineralization crystallized silver-antimony sulfosalts are considered.to be singular as the Korean type gold deposit.

Metastasis of lung carcinoma to proximal femur after hip implant.

Abstract: Adenocarcinoma of the lung metastasized to the site of hemiarthroplasty for a femoral neck fracture in a 73-year-old woman who had no evidence of preexisting primary or metastatic tumor. The mechanism of the metastasis in this patient remains a question, but it seems likely that metastatic tumor seeding occurred as the result of surgical trauma after the prosthetic implantation.

The egg detection rates of Enterobius vermicularis among school children in the various regions

Abstract: A total of 860 cellotape anal swab specimens from 326 school children of urban area, 243 of rura1 farm village and 291 of rural fishing village was submitted for Enterobius vermicularis egg detection from September through November 1985. Each specimen was collected in the morning. Among the total 860 children's submitting specimens, 316 (36.7 per cent) were positive for E. vermicularis eggs. Of the 326 children in the urban area, E. vermicularis eggs were detected in the 45 (13.8 per cent). This detection rate was lower significantly as compared with 143 (55.6 per cent) of 243 children in the farm village or 136 (46.7 per cent) of 291 children in the fishing village. The egg detection rate in the male children was lower remarkably than that in the female children.

The peroxidative activation of butylated hydroxytoluene to BHT-quinone methide and stilbenequinone.

Abstract: Butylated hydroxytoluene (BHT, 2,6-di-tert-butyl-4-methyl-phenol) is a commonly used antioxidant allowed in foods in amounts up to 0.02% of the weight of fat present. BHT helps prevent undesirable oxidation reactions from occurring by acting as a free radical scavenger. BHT is also used as a stabilizer in pesticides, gasolines and lubricants, soaps and cosmetics, and as an antiskinning agent in paints and inks (1). BHT has been shown to have a protective effect against the toxicity and carcinogenicity of a wide variety of chemicals (2). However, several recent animal studies have questioned the presumed safety of this antioxidant. For example, BHT has been shown to cause lung damage in mice (3,4), hemorrhagic death in rats (5) and can act as a tumor promoter in both mice and rats (6,7). One of the best characterized toxic effects of BHT is the destruction of type I alveolar and pulmonary endothelial cells (8) in the mouse lung. This lung damage is thought to arise from the biotransformation of BHT into BHT-quinone methide (2,6-di-tert-butyl-4-methylene-2,5-cyclohexadienone) (9,10), a highly reactive compound (see Figure 1). BHT has been demonstrated to be metabolized to BHT-quinone methide in vivo in the mouse (10) and rat (11). This reaction is presumably catalyzed by a cytochrome P-450 related enzyme (12,13). As a class of chemical compounds, quinone methides have been shown to react with cellular nucleophiles including amines, carbohydrates, alcohols, thiols, and olefins (14).

Patterns of topic sequencing and information gain: A comparative study of relationship development in Chinese and American cultures

Abstract: Patterns of inferred information, information gain, and topic placement for Chinese and American respondents were compared. Based on pilot interviews and existing literature, four hypotheses were derived: 1) Chinese respondents infer more information about others when introduced, 2) displace topics later in time, and categorize more messages as 3) prohibited and 4) obligatory. Respondents read a description of initial meeting, completed information scales, and sorted a set of statements. Results partially supported the first three hypotheses. Hypotheses 4 was not supported. Results suggest the diversity of cultural patterns and the differences between message content and information gain.

On the relation between the maximum entropy probability density function and the autoregressive model

Abstract: The problem of maximizing the entropy of an n-variate random vector subject to constraints on the first p + 1 autocovariance terms is examined. It is shown that the maximum is achieved by the Gaussian autoregressive process of order p satisfying the autocovariance constraints. This solution provides Burg's theorem about the maximum entropy spectral density as a special case.

Human leukocyte antigen (HLA) in Korean patients with autoimmune thyroid diseases.

Abstract: In previous studies, there has been evidence of different allelic associations with a particular disease among various ethnic groups. The present study was done to investigate the associations between HLA and autoimmune thyroid diseases in the Korean. We found no association between Graves’ disease and HLA-B8 or -B35. However, increased frequencies of HLA-A11 and -DRw8, and the decreased frequencies of HLA-A10 and B12 were found in patients with Graves’ disease. In the cases of Hashimoto’s disease, the frequencies of HLA-A2 and -DRw8 were found to be significantly increased and the frequency of HLA-DRw6y decreased. These data indicate that the association between autoimmune thyroid disease and HLA in the Korean would appear to be different from that in most other racial groups, including Caucasians, Japanese and Chinese.

Adaptive phase transform processors for time delay estimation

Abstract: This paper introduces two recursive realizations of the phase transform (PHAT) processor for time‐delay estimation (TDE), using a simple one‐pole low‐pass filter and the least‐mean‐square (LMS) adaptive filter, respectively. It is shown that these adaptive methods are capable of tracking time‐varying delay functions which correspond to moving sources or receivers, and are very effective in reducing the effect of interfering tonals which must be generated by the target as jamming signals to mask its movement. The performances of these methods are compared with those of other existing adaptive TDE algorithms via computer simulations.

Occupational asthma caused by nickel and zinc.

Abstract: A 28-year-old man developed asthma 10 years after working in a metal-plating factory. Recordings of peak expiratory flow rates showed increased variations after exposure at work. Allergy prick skin tests elicited an immediate reaction with nickel sulfate at a concentration of 1 and 10 mg/ml, and with zinc sulfate at a concentration of 10 mg/ml. Inhalation challenges with nickel sulfate and zinc sulfate produced bronchial obstructions. Thus, we concluded that this was a case of asthma caused by nickel sulfate and zinc sulfate.