Biomedical subjects
Publications and source records attributed to I Y Lee.
We have developed a new method to study the order-to-chaos transition in rotational nuclei. Correlations between successive gamma rays are used to determine the average complexity of the intermediate levels and thereby the ratio of the interaction potential between levels to the level spacing. The measured ratios, 0.15 to 1.5, span the range from nearly fully ordered to nearly fully chaotic.
1. There is evidence that the induction of inducible nitric oxide synthase (iNOS) and peroxynitrite by ischaemia/reperfusion may lead to renal cell injury. Herein, we investigated whether Sheng mai san (SMS), a Chinese herbal medicine, protects against renal ischaemic injury during heat stroke by reducing iNOS-dependent nitric oxide (NO) and peroxynitrite formation. 2. Urethane-anaesthetized rats were exposed to heat stress (ambient temperature 43 degrees C) to induce heat stroke. Control rats were exposed to 24 degrees C. Mean arterial pressure and renal blood flow after the onset of heat stroke were significantly lower in heat stroke rats than in control rats. However, both colonic temperature and renal damage score were greater in heat stroke rats compared with control rats. Similarly, plasma NO, creatinine and blood urea nitrogen (BUN), as well as the renal immunoreactivity of iNOS and peroxynitrite, were significantly higher in heat stroke rats compared with their normothermic controls. 3. Pretreatment with SMS (1.2 g/day per rat for 7 consecutive days before the initiation of heat stress) significantly attenuated the heat stroke-induced arterial hypotension, hyperthermia, renal ischaemia and damage, the increased renal immunoreactivity of iNOS and peroxynitrite and the increased plasma levels of NO, creatinine and BUN. Pretreatment with SMS resulted in a prolongation of survival time in heat stroke. 4. The results of the present study suggest that SMS protects against renal ischaemic damage by reducing iNOS-dependent NO and peroxynitrite production during heat stroke.
The angular-momentum induced transition from a deformed state of collective rotation to a noncollective configuration has been studied. In 157Er this transition manifests itself as favored band termination near I=45 Planck's. The feeding of these band terminating states has been investigated for the first time using the Gammasphere spectrometer. Many weakly populated states lying at high excitation energy that decay into these special states have been discovered. Cranked Nilsson-Strutinsky calculations suggest that these states arise from weakly collective "core-breaking" configurations.
Chiral doublet bands based on the pi g(9/2) multiply sign in circle nu h(11/2) configuration that achieve degeneracy at spin I=17 in the odd-odd triaxial 104Rh nucleus have been observed. Experimental verification of the interpretation has been tested against specific fingerprints of chirality in the intrinsic system.
Lifetimes of states in the lowest lying positive parity band in 106Cd have been measured using the Doppler shift attenuation method. The deduced B(E2) transition rates show a marked decrease with increasing spin. Cranking and semiclassical model calculations suggest that the structure has the character of a shears-type band resulting from the coupling of g(9/2) proton holes to aligned pairs of h(11/2) and g(7/2) neutron particles. This is the first clear evidence for the phenomenon of "antimagnetic" rotation in nuclei.
The objectives of this study were to assess the quality of marital life (QML) in patients with spondyloarthropathy (SpA) in Korea and to identify possible gender differences in QML in patients with SpA. This was a case-control study at the outpatient unit of a tertiary care medical centre. Subjects were the patient group, composed of 47 married patients with SpA, and a comparison group composed of 47 healthy married adults with similar demographic characteristics. QML was measured using the Marital Satisfaction Inventory, Revised. As a result, QML was similar for both the male patients and the healthy men. However, the female patients had higher scores on the global distress scale (59.8 +/- 6.3 vs. 53.8 +/- 5.6, P=0.021) and the aggression scale (50.5 +/- 7.9 vs. 44.3 +/- 5.4, P=0.016) than the female comparison group. At the same time, the female patients demonstrated higher scores on the global distress scale (59.8 +/- 6.3 vs. 54.7 +/- 7.2, P=0.035) than the male patients. In conclusion, QML in Korean males with SpA was not greatly different from that of the male comparison group. However, QML in the female patients was characterised by higher global distress and a higher probability of aggression from their partner, but no significant sexual dissatisfaction.
Adsorption characteristics of a reverse stratified tapered adsorber (RSTA) system and competitive adsorption for phenol and 4-nitrophenol were investigated. In this study, a novel technology, RSTA, was introduced and compared with a conventional cylindrical adsorber (CA). The optimum study of RSTA in a single-solute system with phenol for size distribution, mean velocity and optimum angle was conducted to satisfy environmental criteria and reduce granular activated carbon (GAC) treatment costs. The competitive adsorption efficiency of RSTA and CA was also compared in a binary solute system with phenol and 4-nitrophenol. In the results of single-solute experiment, breakthrough time of RSTA was increased by 30-50% over conventional CA. The mean bed velocity was 19.10 cm/min and the optimum angle of RSTA was decided to 3 degrees. Adsorption efficiency was increased with increasing GAC dose and the number of GAC layers. The affinity of competitive adsorption was significantly increased with decreasing GAC dose and increasing adsorbate concentration. The RSTA can be considered to provide an increase in breakthrough time with decreasing flow rate and increasing the number of layers. Water and wastewater plants processing large volumes of water can realize significant savings in capital and operation costs by utilizing this type of operation.
We have made the first clear measurements of rotational damping widths in nuclei. In a mixture of three Yb nuclei, these widths are 300 +/- 60 keV between 1.2 and 1.5 MeV gamma-ray energy [approximately (37-57)Planck's constant]. Compound damping and motional narrowing are discussed in connection with these results.
STUDY DESIGN: Prospective investigation using serial urodynamic studies. OBJECTIVE: To evaluate type of neurogenic bladder and to observe changes of autonomous detrusor contraction (ADC) after the normalization of the compliance and capacity of the bladder in cauda equina injury. SETTING: Spinal Cord Injury Unit, Yonsei Rehabilitation Hospital, Seoul, Korea. METHODS: Urodynamic studies were performed in 50 patients with complete cauda equina injury from trauma with an infusion ratio of 30 ml/min. Findings of urodynamic studies and clinical features of patients with low compliance were compared with those of the normal compliant patients. Fourteen patients with low compliance received oral administration of oxybutynin and propiverine and intravesical instillation of oxybutynin to increase the compliance and capacity of the bladder, and follow-up urodynamic studies to monitor the change were undertaken. RESULTS: Bladder compliance was decreased in 14 (28%) patients and normal in 36 (72%) patients. There was a significantly long time interval between the onset of injury and the initiation of rehabilitative treatment in the neurogenic bladder group with low compliance when compared to those of the normal compliance group (P < 0.05). Clean intermittent catheterization was used as the voiding method, significantly less than the normal compliance group (P < 0.05). ADC was observed in six out of fourteen patients with low compliance neurogenic bladder, but none in the normal compliance group. Upon the completion of conservative treatment, ADC disappeared in four patients whose compliance and capacity of the bladder were normalized on follow-up urodynamic studies. CONCLUSION: ADC was only observed in the low compliant bladder and as ADC disappeared when compliance and capacity of the bladder was normalized; low compliance appeared to be the main cause of ADC. In addition, this study supports that the maintenance of compliance of the bladder may be the most important factor in the management of neurogenic bladder.
BACKGROUND: Der f 2 is a major sensitizing allergen in patients allergic to house dust mites worldwide. Isoforms of Der f 2 have been reported and are known to have different antigenicities. The aim of this study was to facilitate antigenic analysis and to develop an improved method for the detection of Der f 2 isoallergen, which is prevalent in Korea. METHODS: A two-site ELISA was developed with monoclonal antibodies (mAbs) which were produced against recombinant Der f 2 (rDer f 2) and applied to assess Der f 2 in bedding samples. RESULTS: A major isoform of Der f 2, found in Korea, was found to have amino acid variations especially at position 100 from lysine to glutamic acid, which is known to reduce significantly the binding affinity of mAbs when used to assess group 2 allergens. The detection limit of the developed two-site ELISA was determined to be about 8 ng/ml with rDer f 2 and 1 microg/ml with Derntatophagoides farinae crude extract. The average amount of Der f 2 in dust obtained from bedding samples from 89 homes in Seoul was estimated to be 25.61+/-10.70 microg/g dust. CONCLUSIONS: Assays using mAbs for rDer f 2 could be useful for the assessment of environmental allergen exposure and mAbs could be used to further characterize the isoallergens of Der f 2.
High-angular-momentum states in 108Cd were populated via the (64)Ni((48)Ca,4n) reaction at a beam energy of 207 MeV. Gamma rays were detected using the Gammasphere array. A rotational band has been observed with a dynamic moment of inertia and deduced lower limit of the quadrupole moment suggesting a major-to-minor axis ratio larger than 1.8:1, placing it among the most deformed structures identified in any nucleus, to date.
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The diagnostic ability of the restriction fragment length dimorphism-polymerase chain reaction (RFLD-PCR) method was evaluated. Seven primer pairs, newly designed from 44 beta-lactamase genes encoding extended-spectrum beta-lactamases not related to TEM- and SHV-types, were used to differentiate OXA-2, FOX-3, CMY-3, IMP-1, and IMI-1 beta-lactamases. The RFLD-PCR was carried out successfully, and these genes were differentiated by the sizes of their PCR products and by the difference in restriction fragment length when each amplicon was digested with a unique restriction enzyme. This discriminatory detection of the genes was confirmed by sequencing the PCR products.
BACKGROUND: Cockroaches have been demonstrated to be an etiologic factor in allergic diseases. Further, sensitivity to cockroach places patients with asthma at risk for exacerbations that require emergency medical care. OBJECTIVE: This study compared the differences in allergenic components between German cockroach whole body and German cockroach fecal extracts (GWBE and GFE). METHODS: Patients with asthma and/or allergic rhinitis were skin prick tested with German cockroach extract (Bayer Corporation, West Haven, CT). Serum specimens from these patients, 25 with positive skin tests and 8 with negative tests, were used for the ELISA and immunoblot experiments. RESULTS: By ELISA, 72% (18 of 25) and 60% (15 of 25) of positive responders' sera showed IgE antibodies to GWBE and GFE, respectively, and the IgE levels to GWBE were highly correlated with those to GFE (r = .84, P < .01). In inhibition ELISA experiments, extensive cross-reactivity was observed between GWBE and GFE, slight cross-reactivity between GWBE and Dermatophagoides farinae, and no cross-reactivity between GFE and D. farinae. The two-site monoclonal antibody ELISA detected more of the German cockroach major allergens in GFE compared with GWBE; 6.2 times (2420 vs 390 U/mL) for Bla g 1 and 3 times (15.32 vs 5.07 microg/mL) for Bla g 2. In the immunoblot comparison of patients' sera, the IgE antibodies binding to GWBE were apparently different from those binding to GFE in all the positive responders' sera; eg, 50% or more of the 25 positive responders' sera reacted to 43- to 67-kDa proteins in GWBE and to 28- to 30-kDa proteins in GFE, respectively. No IgE antibodies bound to components in GWBE and GFE in the 8 negative responders' sera. CONCLUSIONS: There are major differences between the allergenic components of GWBE and GFE. Based on the amounts of major allergens (Bla g 1, Bla g 2), German cockroach feces are a more important source of allergen than the whole body in respiratory allergic diseases.
L-Carnitine is an ubiquitous substance that plays a major role in the transportation of long-chain fatty acids. We investigated crucial factors that influence microbial conversion of gamma-butyrobetaine to L-carnitine using an Achromobacter cycloclast strain. Two-stage culture results showed that gamma-butyrobetaine induced enzymes essential for the conversion, which suggests that the precursor should be present in the initial cell growth stage. The addition of yeast extract enhanced L-carnitine production whereas inorganic nitrogen sources inhibited it. Under nitrogen-limiting conditions, the cells accumulated poly-beta-hydroxybutyrate instead of L-carnitine. Among the trace elements tested, nickel addition enhanced L-carnitine production by almost twice that of the control and copper strongly inhibited the conversion. L-Carnitine production was reduced when the medium contained inorganic salts of sodium, potassium, and calcium at a concentration greater than 2 g l(-1). A higher L-carnitine yield was achieved when cells were incubated in a lower culture volume. The optimal pH for L-carnitine production was 5 to 5.5, whereas that of growth was 7.0, indicating that a pH shift was required. Under optimal conditions, L-carnitine concentrations as high as 15 g l(-1) were obtained in 62 h with a 45% molar conversion yield.
STUDY DESIGN: A face-to-face interview survey. OBJECTIVE: To compare bowel care patterns in spinal cord injury (SCI) patients based on type of neurogenic bowel. SETTING: Department of Physical Medicine and Rehabilitation of a tertiary university hospital in Suwon, Korea. METHODS: Among chronic SCI patients, 22 patients with upper motor neuron bowel (UMNB) and 20 patients with lower motor neuron bowel (LMNB) participated in an interview survey for the evaluation of bowel care patterns. RESULTS: The patients with LMNB demonstrated increased frequency of defecation, increased frequency of fecal incontinence, increased use of oral medications for bowel care, increased required time for defecation and more diet modification than those with UMNB (P < 0.05). However, there was no significant difference in the subjective difficulty of bowel care. Among several available bowel care methods, suppositories were used most frequently by the UMNB group, whereas the Valsalva maneuver was the most frequently used method by the LMNB group. CONCLUSIONS: Patients with LMNB tend to suffer more difficulties in management of their neurogenic bowel than those with UMNB. Therefore, more intensive and aggressive bowel care programs should be provided for SCI patients with LMNB.
Field rodents and chigger mites were collected at 30 locations in Korea in October and November 1997-1999 to determine the serotypes of Orientia tsutsugamushi and their geographical distribution. A nested polymerase chain reaction was performed with the spleen tissues from 546 field-striped mice (Apodemus agrarius) and 104 pools of chigger mites. The positivity rate of O. tsutsugamushi was 45.6% in A. agrarius and 39.4% in the chigger mite pools. Two serotypes, Boryong and Karp, were found in these samples; the former was predominant (78.3% in the mice and 82.9% in the chigger mite pools), with wide distribution throughout the country, including Cheju-do. The latter was confined to the middle of the Korean peninsula, with positivity rates of 15.7% in the mice and 12.2% in the chigger mite pools. The double infection of Karp and Boryong serotypes was found in 15 (6.0%) A. agrarius mice. Gilliam serotype was not detected at any of the study locations. The Boryong and Kuroki serotypes were identical in amino acid sequence of the 56-kDa protein, although they differed in virulence to BALB/c mice.
To evaluate the vector efficiency of Anopheles sinensis in transmitting vivax malaria in the northern part of Gyonggi-do, South Korea, daily survival and feeding host preferences were studied during the period of June-October 1999. Ovaries of unfed and freshly fed An. sinensis females were dissected and parity or nulliparity were observed. The parous rates were 75.2% in July, 56.5% in August, 78.5% in September, and 60.0% in October at Gusan-dong, Goyang-si, Gyonggi-do. The average probability of daily survival was 0.890. To determine the host feeding patterns of An. sinensis, outdoor-resting bloodfed mosquitoes were collected, and the sources of the blood meals were analyzed by enzyme-linked immunosorbent assay, using 6 different animal immunoglobulin G antibodies. Out of 305 blood meals tested, 0.7% were positive from humans, 89.8% from bovines, 3.3% from swine, 0.7% from dogs, 1.6% from chickens, and 0.7% from bovines and swine mixed. No blood meals were positive from mice. Though the vector efficiency of An. sinensis was poor because of a low human blood index and a moderate rate of daily survival, vectorial capacity would be high because of high density of the population.