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Biomedical subjects

S M Yoon

Publications and source records attributed to S M Yoon.

12 recordsLinked to original sources
PubMed2005

Thymidine phosphorylase expression in tumour cells and tumour response to capecitabine plus docetaxel chemotherapy in non-small cell lung cancer.

BACKGROUND: Thymidine phosphorylase (TP) is the key enzyme for capecitabine activation in tumour cells. AIMS: To examine whether TP expression in tumour cells and stroma is predictive of the tumour response to capecitabine plus docetaxel chemotherapy in patients with advanced non-small cell lung cancer (NSCLC). METHODS: Tumour samples were available from 30 of 39 patients enrolled in a previous phase II study of capecitabine/docetaxel chemotherapy in patients with advanced NSCLC. Stromal and tumour cell TP expression was evaluated by immunohistochemistry using monoclonal antibody PD-ECGF. RESULTS: High tumour cell TP expression was found in 13 of 30 cases and was negatively associated with stromal TP expression (p = 0.000). High stromal TP expression was found in 16 of 28 cases and was strongly associated with intense macrophage infiltration (p = 0.002), suggesting that macrophages are the major component of TP expression in the stroma. Tumour response to capecitabine/docetaxel was significantly associated with high tumour cell TP expression (p = 0.004) and low stromal TP expression (p = 0.009). Moreover, high tumour cell TP expression was significantly associated with severe hand-foot syndrome, a toxic side effect of capecitabine (p = 0.01). Improved survival was seen for high tumour cell and low stromal TP expression, although results were not significant (p = 0.6 and 0.3, respectively). CONCLUSIONS: In advanced NSCLC, TP expression in tumour cells and stroma is associated with tumour response to capecitabine/docetaxel chemotherapy, and might be a useful predictor of tumour response to capecitabine based chemotherapy. A large scale prospective study is needed to confirm the prognostic significance of TP expression in NSCLC.

Adult↗
PubMed2001

Local structure analysis of Ti species stabilized in ion exchangeable layer solids by x-ray absorption spectroscopy.

Nano-sized titanium dioxides are incorporated into the interlayer spaces of ion-exchangeable layered perovskites, H(1-x)Ca2(x)La(x)Nb3O10 (x=0.0-0.75), by replacing the interlayer protons with positively charged TiO2 nano-sol particles or basic titanium glycolate complex (titanatrane). Powder X-ray diffraction analysis. UV-Vis absorption spectroscopy, thermogravimetric analysis, and N2 adsorption-desorption isotherm measurements show that quantum sized TiO2 particles are stabilized in between perovskite lattices to form micropores (S(BET) = 37-110 m2/g). X-ray absorption spectroscopy at the Ti K-edge was used for investigating the local environment around Ti atoms constituting the interlayer pillars. According to the XANES spectra, the 'as-pillared' Ti species have the same local environments with those of precursory species, which subsequently converted into TiO2 clusters with rutile and anatase-like local structures when TiO2 nano-sol particles and titanatrane are used as pillaring species. respectively. It is also found that the local environment of TiO2 remains almost constant irrespective of the layer charge density, while the TiO2 pillar content and the microporosity increase with the latter.

Journal Article↗
PubMed2001

The difference in perceptions of educational need between epilepsy patients and medical personnel.

PURPOSE: This study was undertaken to determine what patients with epilepsy need to know about their condition, and to discern what differences exist between patients' perceptions of this need and the medical profession's perception of what patients should know. METHODS: Seventy-five consecutive patients with epilepsy and 56 medical personnel (residents and nurses) who were working in either Neurology or Neurosurgery Units were studied using a structured questionnaire consisting of 3 subsets with a total of 27 questions. RESULTS: Using a Likert scale, epilepsy patients gave high priority to their need for more information about "how epilepsy is diagnosed," "the structure of the brain" (p < 0.05, p < 0.01, respectively), and "the diet that might prevent the attack" (p < 0.05) than did medical personnel. Our study also revealed that men were more concerned with questions regarding smoking and drinking than were women (p < 0.05, respectively), whereas married patients gave higher scores in the category of employment (p < 0.01) and contraception/pregnancy (p < 0.05) than did unmarried patients. The patients with one or more seizures per month rated higher scores on questions concerning the first aid at the time of attack and dosage of antiepileptic drugs (AEDs; p < 0.05, respectively) than did the patients with fewer than one seizure per month. The patients taking poly-AED treatment gave higher scores on six items related to AED therapy than did those receiving monotherapy. No significant differences were found with regard to the length of time patients had the condition, nor to educational level or current employment status. CONCLUSIONS: An educational program for epilepsy patients should be developed on the basis of understanding that there are differences in perspectives among patients with different sociocultural contexts as well as between patients and medical personnel.

Adult↗
PubMed2001

Location of the chronic subdural haematoma: role of the gravity and cranial morphology.

Chronic subdural haematoma (SDH) frequently originates from subdural hygroma (SDG). The cranial morphology can determine the location of SDG. Since SDG is the precursor of chronic SDH, the shapes of the cranium wall act an important role in location of chronic SDH. The authors tried to test this hypothesis. The computed tomographic scans or magnetic resonance images of 118 consecutive patients with chronic SDH were re-evaluated, and the symmetry of the cranium and location of the lesion were checked. The cranium was symmetrical in 55 patients (47%) and asymmetrical in 63 patients (53%). Chronic SDH was bilateral in 25 patients (21%) and unilateral in 93 patients (79%). It was more commonly bilateral in symmetrical craniums than in asymmetrical craniums (29.1% vs. 14.3%) (p = 0.0496). In 63 patients with asymmetric cranium, the chronic SDH was bilateral in nine patients, located on the opposite side of the flat side in 38 patients, and located on the same side of the flat side in 17 patients. This unequal distribution was statistically significant (p = 0.03). In four patients, the haematoma originated from the acute SDH located on the same side of the flat side. No reason could be found in the remaining 13 patients. Chronic SDH originating from SDG usually locates on the opposite to the flat side of the skull. The shape and posture of the cranium can predict the location of chronic SDH, as in the SDG.

Adolescent↗
PubMed2001

Prostate shape and symptom score in benign prostatic hyperplasia.

Prostates of the same volumes were found to have very variable shapes, that is, combinations of variably elongated width, height, and lengths. These were believed to be possible causes of the differences in the severity of both the obstructions and symptoms in the prostates even when their volumes were similar. We measured the transverse (width), anterior-posterior (height) and longitudinal (length) diameters of the prostates and the transition zone, and their calculated volumes using transrectal ultrasonography. To establish the relationship between the International Prostate Symptom Score (IPSS) and each of the dimensional parameters of the transition zone and the total prostate, 105 consecutive patients (mean age 66.43 +/- 9.24 years with a range o6f 46 to 90) who had voiding dysfunctions that were presumably related to BPH were analyzed using the t-test. Patients with conditions other than BPH were excluded. The results were as follows: 1. There was no significant correlation between the IPSS and any prostate volume parameter in the constant prostate volume conditions, because of the small numbers in each group. However, in the analysis of the total number of cases in all the volume categories, a significant correlation was found between the IPSS and some prostate dimensions; i.e., the longitudinal parameters in the total prostates (p < 0.01), and the transverse (p < 0.05) and longitudinal parameters (p < 0.05) in the transition zones. 2. Further investigations of the statistics of these significant parameters showed that prostates that were longer than 4 cm had significantly more severe symptoms than prostates shorter than 4 cm (p < 0.05), and that prostates with a ratio of length in the transition zone to the length in the total prostate ratio that was greater than 0.8 had significantly higher symptom scores than those with lower ratios (p < 0.05). When evaluating patients who have BPH, it is important to consider the shape of prostate. More aggressive treatment may be indicated in cases where the transition zone lengths exceeds 4 cm and the transition zone to total prostate length ratio exceeds 0.8.

Aged↗
PubMed2001

Denitrification in submerged biofilters of concentrated-nitrate wastewater.

To understand the possibilities and limitations of the treatment of concentrated nitrate in wastewater, a space-saving biofilm process was introduced to investigate how efficiently concentrated nitrate was utilized in a biofilm process. Lab-scale submerged biofilters stuffed with plastic pall-ring media were developed for the treatment of wastewater containing high nitrate concentration. Two identical biofilters were operated at 2 and 4 hr media HRT in parallel and the concentration of nitrate in the influent was increased stepwise from 50 to 3000 mg-N/L. The concentration of NOx in the effluent was measured at various volumetric loading rates that were proportional to influent nitrate concentrations. There was a critical point for volumetric loading rate (9 kg NO3-N/m3/day) distinguishing the biofilter performances. At the volumetric loading rate below this critical point, the effluent NOx concentration was maintained steadily in spite of the drastic change in the loading rates. However, the effluent NOx concentration severely fluctuated for the small change when the loading rate was higher than the critical point. It was found that the reactor performance was closely related with the biomass concentration (g-dw/ring) in the biofilters.

Biofilms↗
PubMed2000

Comparison of two immunization schedules for a Pseudomonas aeruginosa outer membrane proteins vaccine in burn patients.

The aim of the present study was to compare two immunization schedules for a Pseudomonas aeruginosa outer membrane proteins (OMPs) vaccine in burn patients. In a double-blind, randomized and placebo-controlled clinical trial, 95 adult patients with burn injuries in 10% or greater of total body surface area were randomly allocated to either placebo or immunization groups. Three doses of the vaccine (0.5 or 1.0 mg) were administered intramuscularly at either 3- or 7-day intervals. The vaccine was well tolerated, and no severe adverse reactions were observed in any of the vaccinees. After three immunizations, 88 patients were available for evaluation of serum antibody titers. Elevation of OMPs-specific antibody titers in the immunization groups was significantly higher as compared with the placebo group, and the highest antibody response was obtained by immunization with 1.0-mg doses at 3-day intervals. Conventional blood culture, tissue culture of wound biopsy specimens and a nested polymerase chain reaction (PCR) assay of blood specimens were performed to determine the protective efficacy. The results of the nested PCR indicated that the overall detection rate of P. aeruginosa in blood was significantly lower among immunized patients than placebo patients (6.1 vs. 40.0%, P<0.001). Based on these results, we concluded that the P. aeruginosa OMPs vaccine is safe and highly immunogenic in burn patients, especially with 1.0-mg doses at 3-day intervals, and may be effective in conferring protection against P. aeruginosa bacteremia in burn patients.

Adult↗
PubMed2000

Immunization of burn-patients with a Pseudomonas aeruginosa outer membrane protein vaccine elicits antibodies with protective efficacy.

The aim of this study was to determine whether the antibodies raised in burn patients by active immunization with a Pseudomonas aeruginosa OMPs vaccine have a protective efficacy against infection with P. aeruginosa. The binding patterns with P. aeruginosa OMPs of immunized burn patient sera were similar to the sera of immunized healthy humans as determined by immunoblot and immunoprecipitation analyses. The sera pooled from immunized burn patients after three immunizations showed a significantly higher opsonophagocytic-killing activity than the corresponding pre-immune sera, while the sera from unimmunized patients collected at the same day did not. Passive immunization of mice with post-immune sera of burn patients significantly enhanced the survival rate upon a lethal challenge with P. aeruginosa compared to the pre-immune sera, indicating the protective ability of the antibodies induced in burn patients by immunization. These results suggest that anti-P. aeruginosa OMPs antibodies elicited in burn patients by active immunization are protective against infection with P. aeruginosa, and provide a rational for further development of the vaccine for prevention against P. aeruginosa infection in burn patients.

Animals↗
PubMed2000

Location of the traumatic subdural hygroma: role of gravity and cranial morphology.

Traumatic subdural hygroma (TSH) is frequently bilateral and locates on the top of the head in a supine position. It suggests that the gravity and cranial posture act a certain role. The authors tried to test this hypothesis. The computed tomographic (CT) scans or magnetic resonance (MR) images of 86 consecutive patients with TSH were re-evaluated. The symmetry of the cranium, the posture of the head during the radiological examinations, and the location of the lesion were all checked. The cranium was symmetrical in 47 patients and asymmetrical in 39 patients. TSH was more commonly bilateral in patients with symmetrical cranium than those with asymmetrical cranium (77% vs 62%). The asymmetrical cranium tended to turn to the flat side. It was more frequently oblique in MR images, which has a long scanning time, than in CT (29% vs 18%). In 39 asymmetric craniums, TSH was bilateral and it was symmetrical in 14 cases. In the remaining 25 cases, TSH located opposite to the flat side in 18 cases. In seven patients with the same side TSHs, four patients had it on the side of atrophy, two on the opposite side of a mass lesion. The gravity and cranial posture can predict the location of TSH. TSH usually occurs at the least pressure in the cranium as a lesion of ex vacuo.

Adolescent↗
PubMed1999

Non-insulin-dependent diabetic microangiopathy in the inner ear.

UNLABELLED: Hearing loss has long been associated with diabetes mellitus. Microangiopathy, associated with thickening of the basement membranes of small vessels, has been implicated as a major source of multiple system organ disease. OBJECTIVE: This study was designed to evaluate changes in basement membrane thickness in the inner ear of laboratory animals suffering from non-insulin-dependent diabetes mellitus (NIDDM) with, and without, exposure to moderate intensity noise exposure in an attempt to extrapolate the same disease process in humans. DESIGN: Spontaneously hypertensive-corpulent non-insulin-dependent rats (SHR/N-cp) were selected as a genetic model for the above study. Both lean and obese rats were used in this study. A genetically similar control group of animals (LA/N-cp) were used as controls. These animals express both the lean and obese phenotypes, but they lack the NIDDM gene. Forty-eight animals in each group were sacrificed at the end of the study. The cochleas were dissected and fixed. The basement membrane of the stria vascularis was examined using transmission electron microscopy. SETTING: This study was a laboratory-based, standard animal study. MAIN OUTCOME: This study was designed to show microangiography of the inner ear as related to NIDDM with, and without, obesity and noise exposure. RESULTS/CONCLUSIONS: NIDDM alone does not cause statistically significant basement membrane thickening; however, NIDDM in combination with obesity and/or noise exposure did show significant thickening and the combination of all three showed the greatest thickening. NIDDM appeared to be the greatest contributing factor.

Animals↗
PubMed1999

Comparison of rocuronium and vecuronium pretreatment for prevention of fasciculations, myalgia and biochemical changes following succinylcholine administration.

BACKGROUND: The purpose of this study was to assess the effect of rocuronium pretreatment on the succinylcholine-induced fasciculations, myalgia and biochemical changes, and to compare it with vecuronium pretreatment. METHODS: We have studied 60 female patients undergoing minor elective surgery, in a prospective double blinded method. Three groups of 20 patients each was pretreated with either saline (control group), rocuronium 0.05 mg/kg (rocuronium group) or vecuronium 0.007 mg/kg (vecuronium group). Three min after the pretreatment, 1.5 mg/kg succinylcholine was injected. Single twitch responses to electrical stimulation were measured. Serum potassium and creatine kinase were respectively measured 5 min after succinylcholine and 24 h after operation. Fasciculations and myalgia on postoperative day 1 and day 2 were evaluated. RESULTS: The incidence of fasciculations was lowest in the rocuronium group, followed by the vecuronium group, and was highest in the control group. The incidence of myalgia on postoperative day 1 was lower in the rocuronium and vecuronium groups than the control group. The increase of serum creatine kinase was similar among the three groups, but there was no increase in serum potassium concentration in any group. No differences of the single twitch responses to electrical stimulation were found between the rocuronium and vecuronium groups. CONCLUSIONS: Rocuronium pretreatment was more effective in reducing fasciculations than was vecuronium pretreatment, but both were equally effective in preventing myalgia on postoperative day 1. This difference may reflect the differential activities of rocuronium and vecuronium at the neuromuscular junction. The increase of creatine kinase was not attenuated by any regimen.

Adult↗