Showing papers by "Yonsei University published in 1989"

Extended broad spectrum β-lactamase in Klebsiella pneumoniae including resistance to cephamycins

Abstract: A plasmid-encoded β-lactamase conferring extended broad spectrum resistance including cephamycins was identified in aKlebsiella pneumoniae strain isolated from a patient's wound. Strains harbouring the plasmid pMVP-1 were resistant to penicillins, cephalosporins of all generations (parenteral and new oral compounds) cephamycins, aztreonam, tetracycline, chloramphenicol, sulfonamides and to all aminoglycosides modified by AAC-(6)-I-transferase. β-lactams still active against these strains were temocillin, ceftazidime, cefpirome, carumonam and the carbapenems imipenem and meropenem. The new cephamycinase (CMY-1) was more strongly inhibited by sulbactam in the majority of combinations than by clavulanic acid or tazobactam. MICs of ceftazidime and carumonam were not reduced by inhibitors in the wild type and the transconjugant. A transferable plasmid (pMVP-1) of about 9.6 × 107 dalton was demonstrated by gel-electrophoresis. In the wild type and the transconjugant a β-lactamase with an isoelectric point of 8.0 was identified. This enzyme CMY-1 is different from the other extended broad spectrum β-lactamases (TEM-3 to TEM-10, SHV-2 to SHV-5). The incidence of this enzyme may be underestimated, since resistance to cephamycins in Klebsiella andEscherichia coli has so far been regarded as almost exclusively chromosomally encoded and sensitivity of CMY-1 to clavulanic acid is low. Therefore, screening for CMY-1 beta-lactamases by the usual double disk test including clavulanic acid is not sensitive enough to detect CMY-1 producers. Sulbactam (e. g. in combination with ampicillin) disks and a cephamycin should therefore be used as well when screening for super extended broad spectrum (SEBS-) beta-lactamases.

Replantation and revascularization of hands: Clinical analysis and functional results of 261 cases

Abstract: During the past 4 years we performed 261 replantations and revascularizations on amputated digits and hands in 153 patients. The overall survival rate was 82%. Clean-cut proximal level amputations and hypothermically preserved amputation parts had the highest survival rate. A higher survival rate and more satisfactory results with accelerated return of sensory function correlated with repair of both digital arteries and two veins rather than only one. All patients experienced intolerance to cold, but this was more troublesome in patients with digital replantation in whom only a single artery was repaired. Digital sensibility and joint motion after replantation were better in these patients who had sharp amputations and on whom repairs were carried out in zone III. Return of intrinsic muscle function after hand replantation was poor; however, patient satisfaction with the procedures remained high.

The Ames Salmonella/Microsome Mutagenicity Assay: Issues of Inference and Validation

Abstract: The importance of chemically induced mutation for human health is discussed briefly, and the biological basis for the primary in vitro assay for mutagenicity, the Ames Salmonella/microsome assay, is reviewed. A previous analysis for Ames test data, based on two mathematical models of the competing risks of mutation and toxicity, is shown to have inflated false-positive rates. A reason for this is the existence of local singularities in the Fisher information matrix. A new likelihood ratio test incorporating a pretest of a nuisance parameter is proposed, and its size is validated with replicated experimental data through an analysis based on a finite-mixture-of-binomials model.

Detection of physiological events by impedance.

Abstract: The current emphasis on the acquisition of physiological data by noninvasive means for mass medical screening and patient monitoring has increased interest in the use of electrical impedance for the measurement of physiological events. The technique has gained some degree of acceptance for monitoring respiration (Baker & Geddes, 1970), and much interest has been displayed recently in use of the technique to measure cardiac output including studies by Kubicek et al. (1966) Judy et al. (1969), and Mohapatra (1981). Other applications using the impedance technique include thoracic fluid accumulation, peripheral blood flow, cerebral blood flow, muscle contraction, eye movement, and uterine contraction, etc. The purpose of this article is to introduce the various impedance techniques for the measurement of physiological variables.

Erythema nodosum-like lesions in Behçet's syndrome: a histopathologic study of 30 cases.

Abstract: Thirty patients who fulfilled the criteria for complete and incomplete types of Behcet's syndrome were studied to determine the histopathologic changes of erythema nodosum-like lesions. Lymphocytic vasculitis was observed in 12 (40%) of the cases, but it was only focal in areas of severe lymphocytic inflammation and only mild in degree. No diffuse vasculitis was seen. It is our opinion that the observed lymphocytic vasculitis is only secondary to moderate or severe lymphocytic inflammation. Twelve cases (40%) revealed septal panniculitis, 10 cases (33%) demonstrated lobular panniculitis with moderate to marked inflammation and fat cell necrosis, and 8 cases (27%) showed mild and nonspecific inflammation in the panniculus. Therefore, there is a spectrum of histopathologic changes of erythema nodosum-like lesions in Behcet's syndrome, similar to that of erythema nodosum secondary to other systemic disorders.

The emergence of the modern university in Korea

Abstract: This article examines Western influence on the development of Korean higher education, which is characteristic of the predominance of adaptation to the American ideas and practices from the beginning in the late nineteenth century. The roots of American influence can be seen developmentally as representing three sets of entangled issues: the role of the early American missionaries in practice and unconstrained accommodation in resisting the Japanese oppression; the increase of American-educated scholars and their change-agent leadership; and the newly emerging definitions of nationalism and collaborative relationship between the change-agent and the indigenous group. The most probable schema to respond to the Western influences on Korean higher education is to view Western development as one of the sources challenging endogenous change, while treating it also as an influential force. The institutions of higher education in Korea are now faced with strong pressures for increased academic nationalism as well as for excellence comparable to that of Western advanced countries, dealing with the Western influences rather as a source of data for their own development.

Nevus comedonicus associated with epidermal nevus.

Abstract: A 21-year-old man had a zosteriform nevus comedonicus associated with a surrounding hyperpigmented maculopapular eruption, which had the histologic appearance of epidermal nevus. Scanning electron microscopic examinations of the comedones and the surrounding epidermal nevus showed a common feature, that is, chrysanthemum-like keratotic plugs. The association of a nevus comedonicus with an epidermal nevus and the common scanning electron microscopic findings of both suggest that a nevus comedonicus probably is an uncommon form of epidermal nevus.

Permeability of the blood brain barrier for 125I-albumin-bound bilirubin in newborn piglets.

Abstract: Permeability of the blood brain barrier (BBB) for bilirubin and 125I-albumin was studied in 2-d- and 2-wk-old piglets. 125I-albumin was given by bolus at the beginning of each study. Hyperbilirubinemia was produced by an initial bolus infusion of bilirubin and sustained at a plasma bilirubin:albumin molar ratio of approximately 1.0 by continuous infusion of bilirubin for 3 h. During the study period, arterial pH and blood gas tensions, serum osmolarity, and mean arterial blood pressure were within the physiologic range for age in both groups. Serum albumin and serum total and unbound bilirubin concentrations were higher in the 2-wk-old piglets. Brain bilirubin concentrations and permeability (P.S product) of the BBB for bilirubin were higher in the 2-d-old than in the 2-wk-old piglets, but the values of P.S for albumin were not different between the two groups. In 2-d-old piglets, regional brain bilirubin concentrations and permeability of the BBB were higher in subcortical regions (cerebellum and brainstem) than in the cerebral cortex. Regional brain albumin concentrations and BBB permeability to albumin in 2-d-old piglets were higher only in the cerebellum. In all regions, the bilirubin:albumin molar ratio was higher in the brain tissues than in the blood. In 2-wk-old piglets, the brain concentrations and P.S products for bilirubin were lower and the regional differences were less marked than for 2-d-old animals.(ABSTRACT TRUNCATED AT 250 WORDS)

Radioiodinated fatty acid esters in the management of hepatocellular carcinoma: preliminary findings

Abstract: Radioiodinated fatty acid esters, such as lipiodol or ethiodol, are localized in the hypervascular hepatocellular carcinoma (HCC) for a long time following intra-arterial hepatic injection, enabling delivery of high internal radiation to the tumor. The desired radiation can easily be delivered to small HCC, less than 5 cm in diameter, in single or multiple procedures with an 8-week interval. For larger tumors, [131I]lipiodol or [131I]ethiodol in conjunction with chemotherapy emulsion, Ivalon embolization or all three combinations should be considered for maximal clinical results. A strong beta emitter with shorter physical half-life, i.e. 90Y will be more effective in the management of HCC if one can label lipiodol with 90Y.

Hazard from weapons impulses: histological and electrophysiological evidence.

Abstract: Current methods of rating the hazard of weapons impulses for the ear have recently been challenged by electrophysiological data from experiments with animal ears which indicate that the hazard from low‐frequency impulses is much lower than the hazard from higher frequency impulses (Dancer et al., 1981; Price, 1986b). To supplement these data, histological data are reported here for 51 cats that were exposed on one occasion to either rifle or howitzer impulses at peak pressures from 145 to 155 dB or 153 to 166 dB, respectively. Histological procedures (scanning electron and light microscopy) were carried out over 2 months after the exposure and after electrophysiological measures had been made. For both types of impulse the losses tended to be in the middle of the cochlea in focused lesions, even though the spectral peaks of the acoustic stimuli had been at about 80 Hz (howitzer) and 1000 Hz (rifle). Outer hair cells were more susceptible than the inner hair cells and interindividual differences in effects...

The incidence of congenital color deficiency among Koreans.

Abstract: It is important to investigate the incidence of congenital color deficiency and to determine the type and degree because the color deficiency can effect as a handicap to certain occupations. The incidence of congenital color deficiency is remarkably constant among Caucasians but other races show considerable variations. We investigated the incidence of congenital color deficiency among Koreans by the use of H-R-R pseudoisochromatic plates. The present study revealed that the incidence of congenital color deficiency among Koreans was 31.5% (5.90% in men, 0.44% in women).

Lateral neck mass as the initial manifestation of thyroid carcinoma.

Abstract: Of 238 thyroid cancer patients, 24 exhibited a lateral neck mass as the initial presentation. Twenty four (77.4%) of 31 metastatic masses were located at the midjugular and lower jugular lymph chains. The average number of histologically proven metastatic nodes was 6.5. Histologically, 22 cases were diagnosed as papillary carcinoma, 1 as follicular carcinoma, and the remaining case as medullary carcinoma. Fifteen thyroid glands were found to have a single primary focus, while 9 others had multiple foci. The mean diameter of the primary foci was 1.2 cm. The rates of detection of primary foci by thyroid scan and ultrasonography were 60% and 37.5%, respectively. Surgical procedures for the thyroid lesions included total or near-total thyroidectomy in 18 cases and lobectomy in 6 cases; for metastatic neck nodes, 13 were treated by modified neck dissection, 5 by standard radical neck dissection, and six by partial neck dissection. All 24 patients were followed for a mean duration of 4.5 years with a range of 2.0 to 7.5 years, and all except 1 are still living. In the presence of a lateral neck mass as the initial manifestation of thyroid carcinoma, no matter what size the primary tumor foci, a total or near-total thyroidectomy appears to be justified in addition to an appropriate neck dissection.

Occupational asthma and IgE antibodies to reactive dyes.

Abstract: Reactive dyes have been widely used in recent years. This paper reports nine cases of immediate type occupational asthma to reactive dyes in one dye industry. All patients had had asthmatic symptoms, four had had rhinitis and they had worked for 6 to 25 months. Skin prick tests with reactive dyes were positive and bronchoprovocation tests also produced immediate or dual types of bronchoconstriction. We used the radioallergosorbent test (RAST) technique with nitrocellulose filter paper as a solid phase to detect specific IgE to four reactive dye-human serum albumin conjugates. High specific IgE binding was found in eight asthmatic workers compared with 13 negative controls. The RAST inhibition test revealed that there was no immunological cross-reactivity between 4 reactive dyes. These results suggested that the mechanism of their asthmatic symptoms was immunological, mostly an IgE-mediate reaction.

Foreign body epithelioid granuloma after cosmetic eyebrow tattooing.

Abstract: We describe two patients with epithelioid granulomatous inflammation on the eyebrows after undergoing cosmetic eyebrow tattooing. We tried to analyze the causative elements from biopsy specimens and tattoo inks with x-ray microanalysis. We suggest that granuloma caused by cosmetic eyebrow tattooing is a complication worthy of mention.

Behçet's syndrome associated with bullous necrotizing vasculitis

Abstract: We recently saw a case of Behcet's syndrome in an 11-year-old Korean boy who had severe bullous necrotizing vasculitis as a skin manifestation. The patient exhibited three major criteria of the Shimizu classification, namely, oral and genital ulcerations, uveitis, and bullous necrotizing vasculitis as the skin manifestation. Immunologic laboratory data showed an increased OKT4/OKT8 ratio and a lymphocyte stimulation index with phytohemagglutinin. A skin specimen taken from a developing lesion showed features of lymphocytic vasculitis extending into the panniculus.

The chondrocutaneous postauricular free flap.

Abstract: Use of the auriculomastoid region as a donor-site for a microvascular free flap is still not the general consensus. This report presents three patients with composite tissue defects of the face aesthetically reconstructed with a chondrocutaneous postauricular free flap. For its safe surgical application, additional anatomic knowledge was refined with cadaver study. Use of the chondrocutaneous postauricular free flap has some merits. Its dissection is straightforward and safer than when only the cutaneous unit is used. It also offers a more dependable vascularized composite tissue as a one-stage operation. With freedom of design, a variable combined facial defect can be delicately reconstructed. The final aesthetic results obtained were gratifying, and the donor-site deformity was minimal.

Thermomechanical Properties of β‐Sialon Synthesized from Kaolin

Abstract: β-Sialon powder was synthesized by the simultaneous reduction and nitridation of Hadong kaolin at 1350°C in an N2–H2 atmosphere, using graphite as a reducing agent. The average particle size of β-sialon powder was about 4.5 μm. The synthesized β-sialon powder was pressureless sintered from 1450° to 1850°C under a N2 atmosphere. The relative density, modulus of rupture, fracture toughness, and microhardness of β-sialon ceramics sintered at 1800°C for 1 h were 92%, 248 MPa, 2.8 MN/m3/2, and 13.3 GN/m2, respectively. The critical temperature difference (ΔTc) in water-quench thermal-shock behavior was about 375°C for the synthesized β-sialon ceramics.

Chlorophyll derivatives--a new photosensitizer for photodynamic therapy of cancer in mice.

Abstract: The in vivo photosensitizing efficacy of chlorophyll derivatives (CpD), which had been developed as a new photosensitizer, was compared with that of hematoporphyrin derivatives (HpD). A murine tumor model implanted subcutaneously with S-180 cells on the abdomen was used. The CpD or HpD was administered by intratumoral injection, and light of appropriate wavelength was irradiated on the tumor areas for 10 minutes at 1h and 24h or 24h and 48h after the injection of photosensitizer. When CpD was injected, the early irradiation group (1h and 24h) showed a 100% tumor cure rate; however, the late irradiation group (24h and 48h) showed a 60% tumor cure rate (p less than 0.01). This showed that the early irradiation with light after injection of CpD was an important factor for obtaining better results. With HpD, there was no difference in tumor cure rate between early (1h and 24h, 80%) and late irradiation (24h and 48h, 80%) groups. Thus, in early irradiation groups, the tumor cure rate using CpD (100%) was superior to that of HpD (80%) (p less than 0.05). However, in late irradiation groups, the tumor cure rate using CpD (60%) was inferior to that of HpD (80%), but this difference was not statistically significant (p greater than 0.1). Pathologic sections of these tumors were made before treatment and 48h and 3 weeks after treatment. These showed geographic necrosis at 48h after treatment and no viable tumor tissue at 3 weeks after treatment. Our results showed that CpD was as effective as HpD as a photosensitizer for in vivo photodynamic therapy.

Reverse-flow postauricular arterial flap for auricular reconstruction.

Abstract: Two patients with an ear defect, each reconstructed with a reverse-flow postauricular arterial flap are presented; one defect was caused by accidental exposure of bare cartilage at the posterior helix and the other by traumatic loss of earlobe After the flaps were transposed, a line of auditory signals was dictated by Doppler probing, which suggested the presence of reverse blood flow in the flaps from the anteroauricular vessels We believe that the reverse-flow postauricular arterial flap is a reliable and convenient optional tool in the reconstruction of auricular defects

The prevalence of head louse infestation among urban and rural children in Korea

Abstract: The prevalence of head louse (Pediculus hamanus var capitis) infestation in preschool and school children in 9 urban and 8 rural areas of Korea, was investigated Of 11,865 children who were examined for head lice and nits, 2,900(244%) were found infested The over-all infestation rate of rural children, 589%, was higher than that of urban children, 144% There also existed significant differences in the infestation rate among various regions of urban as well as rural areas Females were more infested than males But there was no differences in infestation rate in either sex of preschool age The infestation rate increased gradually from the age of 6, reached a plateau between 9-12 years of age and thereafter slowly decreased The infestation rate of an orphanage children was higher than that of general childhood population Health education and mass-delousing attempt are urgently required to lower such a high prevalence of head louse infestation in Korea

A new algorithm for P-wave detection in the ECG signal

Abstract: An algorithm is presented for P-wave detection in the ECG signal. The peak and valley points are obtained by using a significant point extraction algorithm with a nine-point derivative. Because P-wave duration is a changing tendency according to heart rate, the R peak is first searched and the R-R interval time calculated prior to the determination of the threshold value of P-wave duration, in order to adapt to the change of P-wave duration actively. The parameter values are determined for P-wave detection, and then the P peak, P onset, and P offset are detected by these parameters values. The results obtained from the proposed algorithm have a detection accuracy of more than 90%. >

Clinical and histopathological study of fibro-osseous lesions of the jaws.

Abstract: Seventy-two cases of benign fibro-osseous lesions of the jaws were reassessed, and a modified classification is proposed that may be helpful in their understanding and management. The anatomical distribution of these cases is described and compared to previously reported cases. The histogenesis of each particular lesion is also discussed. Correlative analysis of histopathologic and oral radiographic features is essential for definitive diagnosis.