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Biomedical subjects

S H Cho

Publications and source records attributed to S H Cho.

At least 55 records · Page 3Linked to original sources
PubMed2001

IgE binding components in Tetranychus urticae and Panonychus ulmi-derived crude extracts and their cross-reactivity with domestic mites.

BACKGROUND: Recent investigation has revealed that spider mites such as Tetranychus urticae and Panonychus ulmi are important allergens in the development of occupational asthma among apple farmers. OBJECTIVE: To evaluate IgE binding components in T. urticae and P. ulmi-derived crude extracts and their cross-reactivity with Panonychus citri, Tyrophagus putrescentiae and Dermatophagoides pteronyssinus in apple cultivating farmers. METHODS: Thirty-one apple farmers with positive skin responses to T. urticae or P. ulmi were randomly recruited, and specific IgE levels in their sera were measured using ELISA. Cross-reactivity was evaluated by ELISA inhibition. IgE binding components were evaluated by IgE immunoblotting. RESULTS: A total of 11 IgE binding components in T. urticae and 10 in P. ulmi were found. Among them, the 17 kDa, 27 kDa, 33 kDa, 37 kDa, 41 kDa, 56 kDa, and 75 kDa allergens in T. urticae, and the 33 kDa, 41 kDa, and 51 kDa allergens in P. ulmi were identified as dominant allergens. T. urticae-specific IgE binding was completely inhibited by 100 microg/mL of T. urticae (99.7%), but only partially inhibited by P. citri (83.0%), P. ulmi (71.6%), T. putrescentiae (69.7%), and D. pternonyssinus (60.1%). P. ulmi-specific IgE binding was completely inhibited by additions of P. citri (92.3%) and P. ulmi (91.2%), but only partially inhibited by the addition of T. urticae (61.5%), T. putrescentiae (57.7%), and D. pteronyssinus (54.4%). CONCLUSION: There were seven dominant allergens found in T. urticae and three in P. ulmi. T. urticae- and P. ulmi-specific IgE bindings were partially inhibited by crude extracts derived from D. pteronyssinus and T. putrescentiae.

Adult↗
PubMed2001

Impact of Bcl-2 and Ha-ras on keratinocytes in organotypic culture.

In this study, the role of specific molecular alterations associated with multistep skin carcinogenesis was assessed using in vitro organotypic cultures of the spontaneously immortalized, nontumorigenic HaCaT keratinocyte cell line. HaCaT vector control clones and clones expressing bcl-2, activated Ha-ras, or both genes were generated. Clones were induced to stratify and differentiate by culturing on dermal equivalents for 2 wk at the air-medium interface. In parental and vector control HaCaT rafts the expression and distribution of cytokeratin K1, K14, involucrin, proliferating cell nuclear antigen, and p21cip1/waf1 were assessed using immunohistochemistry and immunoblotting and were similar to normal epidermis. Apoptosis was also examined using the TUNEL technique. HaCaT-bcl-2 rafts were similar to control rafts but exhibited lower spontaneous rates of apoptosis and a moderate increase in the rate of proliferation. Differentiation was significantly inhibited in HaCaT-ras organotypic cultures and was associated with high rates of proliferation and lower rates of spontaneous apoptosis. Additionally, HaCaT-ras rafts exhibited significantly higher rates of apoptosis following ultraviolet irradiation compared with vector control or HaCaT-bcl-2 rafts. Bcl-2 was able to largely restore normal differentiation, proliferation, and apoptosis in HaCaT-ras/bcl-2 organotypic cultures. Bcl-2 also abrogated apoptosis induction following ultraviolet irradiation in HaCaT-ras/bcl-2 organotypic cultures. Organotypic keratinocyte culture represents a valuable in vitro system to evaluate the impact of individual molecular genetic alterations on the coordinate regulation of cell proliferation, differentiation, and cell death.

3T3 Cells↗
PubMed2001

Impregnation of vancomycin, gentamicin, and cefotaxime in a cement spacer for two-stage cementless reconstruction in infected total hip arthroplasty.

Twenty-two patients with infected total hip arthroplasty were treated with 2-stage arthroplasty, using a cement spacer impregnated with a combination of 3 thermostable antibiotics (vancomycin, gentamicin, and cefotaxime). Initially, implants were removed, and a spacer was inserted. Six to 12 weeks later, the spacer was removed, and the patients underwent reconstruction using cementless components. The patients were followed for an average of 41 months. One patient had a recurrence of infection and was treated with resection arthroplasty. The remaining 21 patients (95%) had no evidence of infection at the final follow-up. We recommend using the combination of these 3 antibiotics in the cement spacer for 2-stage reconstruction in infected hip arthroplasty when the causative organism is not identified in the culture of preoperative aspiration.

Adult↗
PubMed2001

Identification of IgE-binding components of citrus red mite in sera of patients with citrus red mite-induced asthma.

BACKGROUND: Our previous investigations demonstrated that citrus red mite (CRM) antigen could cause IgE-mediated bronchoconstriction in exposed farmers working on citrus farms. OBJECTIVE: This study was performed to confirm IgE-binding components and major allergens within the CRM antigens. METHODS: Ten subjects who had been diagnosed as having CRM-induced asthma were enrolled. Serum-specific IgE antibodies to CRM antigens were measured by using an ELISA. To identify IgE-binding components and major allergens, SDS-PAGE, 2-dimensional PAGE, IgE-immunoblot analysis, and amino acid sequencing of major allergens were performed. RESULTS: All the asthmatic subjects had high specific IgE antibodies to CRMs. Twelve percent SDS-PAGE analysis showed more than 10 protein bands ranging from 6 to 64 kd. SDS-PAGE and IgE-immunoblot analysis with each individual serum showed 5 IgE-binding components (11, 24, 35, 40, and 64 kd), with 2 (24 and 35 kd) of them bound in more than 50% of the study subjects. Two-dimensional PAGE and IgE-immunoblot analysis demonstrated that the major allergen at 24 kd had 2 bands with different isoelectric points of 4.75 and 5.1. Thirty-five kilodaltons had one band with an isoelectric point of 4.75. All amino acid sequencing of the 2 major allergens was performed, which was not homologous with any previously characterized allergens. CONCLUSION: Five IgE-binding components and 2 major allergens (24 and 35 kd) were identified within the CRM antigen. The N-terminal amino acid sequence of the 2 major allergens (24 and 35 kd) was determined.

Adult↗
PubMed2001

Fibronectin and fibrinogen contribute to the enhanced binding of Staphylococcus aureus to atopic skin.

BACKGROUND: Staphylococcus aureus colonizes the skin lesions of more than 90% of patients with atopic dermatitis (AD). The mechanism for increased S aureus colonization in AD is unknown. However, the initial event in colonization requires adherence of S aureus to the skin. OBJECTIVE: The purpose of this study was to examine the roles of various bacterial adhesins on S aureus binding to AD skin. METHODS: In an attempt to delineate the mechanism behind this adherence process, an in vitro bacterial binding assay was developed to quantitate the adherence of various S aureus strains to AD, psoriatic, and normal skin sections. S aureus strains used in this study were obtained either from cultures of AD skin lesions or from genetically manipulated strains of S aureus that lacked specific microbial surface components recognizing adhesive matrix molecules (MSCRAMMs)--namely, fibronectin-binding protein (Fnbp), fibrinogen-binding protein (Clf), collagen-binding protein (Cna), and their parent strains. In addition, S aureus strains from patients with AD were pretreated with fibronectin or fibrinogen to block MSCRAMM receptors and interfere with binding. RESULTS: Under all experimental conditions, binding of S aureus was localized primarily to the stratum corneum. Immunocytochemical staining of AD skin sections showed a redistribution of fibronectin to the cornified layer, an observation not seen in normal skin. S aureus binding to uninvolved AD skin was significantly greater than the binding to uninvolved psoriatic skin (P <.0001) and normal skin (P <.0005). The Fnbp-negative S aureus showed a significant reduction in binding to the AD skin (P <.0001) but not to the psoriatic and normal skin. In the AD skin, a significant reduction in the binding of S aureus was also observed in the Clf-negative strain (P <.0001) but not in the Cna-negative S aureus. Preincubation of S aureus with either fibronectin or fibrinogen also inhibited bacterial binding to AD skin (P <.0001). CONCLUSION: These data suggest that fibronectin and fibrinogen--but not collagen--play a major role in the enhanced binding of S aureus to the skin of patients with AD.

Bacterial Adhesion↗
PubMed2001

The enhanced effect of a hexameric deoxyriboguanosine run conjugation to CpG oligodeoxynucleotides on protection against allergic asthma.

BACKGROUND: Oligodeoxynucleotides containing a CpG motif (CpG ODNs), as potent inducers of T(H)1 immunity, are considered promising candidates for immune modulation in asthma. We have previously demonstrated that conjugation of a hexameric deoxyriboguanosine run to the 3' terminus (3' dG(6)-run) of phosphodiester (PE) CpG ODNs enhanced their immuno-stimulatory activities in vitro. OBJECTIVE: This study aimed to evaluate the effect of a 3' dG(6)-run conjugation to PE or phosphorothioate (PS) CpG ODNs on protection against murine allergic asthma in vivo. METHODS: Balb/c mice were sensitized to ovalbumin by intraperitoneal injection with or without CpG ODNs (PS CpG ODNs, PE CpG ODNs, and those with 3' dG(6)-run) and subsequently challenged with ovalbumin. We evaluated airway hyperresponsiveness, eosinophil proportion in bronchoalveolar lavage fluid, airway inflammation, and ovalbumin-specific antibody responses. RESULTS: The conjugation of a 3' dG(6)-run to PE CpG ODNs enhanced the production of IFN-gamma from ovalbumin-specific T(H) cells and prevented the development of asthma in terms of airway hyperresponsiveness, airway eosinophilia, and ovalbumin-specific IgE responses; these effects were comparable to those of PS CpG ODNs. Enhanced effects of the 3' dG(6)-run were also observed in PS CpG ODNs, though they were lower than those in PE CpG ODNs. CONCLUSION: This study suggests that conjugation of a 3' dG(6)-run to CpG ODNs might provide an effective method for immune modulation of allergic asthma.

Animals↗
PubMed2001

Six cases of confluent and reticulated papillomatosis alleviated by various antibiotics.

Confluent and reticulated papillomatosis (CRP) is a relatively rare disorder manifested by persistent papules that are confluent in the center and reticulated at the periphery with a characteristic distribution. Recently, many cases of CRP treated with minocycline have been reported, and their effect seems to be derived from their antibiotic properties. We report 6 cases of CRP alleviated by various antibiotics. The patient described in case 1 is a 16-year-old girl whose disease was alleviated by oral minocycline, 100 mg daily for 8 weeks. Cases 2 and 3 describe an 18-year-old woman and a 17-year-old male adolescent whose disease was reduced by oral fusidic acid, 1000 mg daily for 4 weeks. Case 4 describes a 14-year-old girl who received oral clarithromycin, 500 mg daily for 5 weeks. Case 5 describes a 22-year-old woman whose disease was reduced by oral erythromycin, 1000 mg daily for 6 weeks. Case 5 reports a 24-year-old man who received oral azithromycin, 500 mg daily 3 times per week for 3 weeks. Complete clearing after treatment with antibiotics raises the possibility that CRP is triggered by a bacterial infection and that antibiotics are the treatment of choice for CRP.

Adolescent↗
PubMed2001

Modification of coagulation and Fenton oxidation processes for cost-effective leachate treatment.

Physicochemical processes have been used to remove nonbiodegradable organic compounds in leachate generated from sanitary landfills. In this study, a coagulation process combined with Fenton oxidation was evaluated for the removal of refractory organics in leachate. Recycling of sludge generated from Fenton oxidation to a coagulation process was attempted to reduce operation cost and to improve organic removal rate. The addition mode of Fenton reagent was also modified to obtain a better organic removal rate and more cost-effective operation. With Fenton sludge recycling, 9% higher COD removal was obtained, and the sludge to be disposed could be reduced up to 50%. Also, the coagulant could be reduced by 50%. For Fenton oxidation process, stepwise addition of reagents gave a 5% higher COD removal, and a 25% reduction in chemical consumption.

Cost-Benefit Analysis↗
PubMed2001

Effects of ambient air pollution on daily mortality in a cohort of patients with congestive heart failure.

This study was planned to test the hypothesis that patients with congestive heart failure are more susceptible to the harmful effects of ambient air pollution than the general population. We used both general additive Poisson regression and the case-crossover approach to test the hypothesis. The effect of air pollution on daily mortality of patients with congestive heart failure among residents of Seoul, South Korea, during the period 1994--1998 was compared with that of the general population in the same area and the same period. The odds ratios and 95% confidence intervals (95% CIs) estimated from general additive models in the general population for an interquartile range increase of particulate matter less than 10 microm in diameter (42.1 microg/m(3)), carbon monoxide (0.59 ppm), nitrogen dioxide (14.6 ppb), sulfur dioxide (9.9 ppb), and ozone (20.5 ppb) were 1.014 (95% CI = 1.006- 1.022), 1.022 (95% CI = 1.017- 1.029), 1.021 (95% CI = 1.014- 1.029), 1.020 (95% CI = 1.012--1.028), and 1.010 (95% CI = 1.002--1.017), respectively. The estimated effects appeared larger among the congestive heart failure patients than among the general population (2.5 approximately 4.1 times higher depending on the pollutants). The results from the case-crossover analysis were similar. The finding of a stronger association in the patients with congestive heart failure reinforces the evidence that a harmful effect of air pollution is mediated by cardiovascular mechanisms.

Adult↗
PubMed2001

Subcapital fractures associated with extensive osteonecrosis of the femoral head.

The authors reviewed 10 patients with subcapital fractures associated with extensive osteonecrosis of the femoral head and distinguished these fractures from traumatic femoral neck fractures The mean age of the patients was 52 years (range, 36-68 years). Nine patients were younger than 60 years. Eight patients had risk factors for osteonecrosis. Necrosis was extensive and involved nearly the whole femoral head. Fracture occurred at the junction between a necrotic bone and reparative bone and extended downward through the reparative interface to the healthy inferior cortex of the femoral neck. Patients experienced hip pain that was aggravated gradually during a period of 1 to 24 weeks before diagnosis of the fracture. In all patients, the opposite femoral head was involved with osteonecrosis. In two femoral heads, slight collapse or subchondral fracture (crescent sign) also was observed. No patient had a history of precipitating trauma. In patients younger than 60 years with a subcapital fracture, fracture associated with extensive osteonecrosis of the femoral head should be suspected when a history of trauma is not obvious, when the opposite hip shows findings of osteonecrosis, and when the patient has a risk factor of osteonecrosis. In these fractures, osteosynthesis rarely should be considered because of the high failure rate caused by additional progression of extensive osteonecrosis and the probability of nonunion.

Adult↗
PubMed2001

(S)-albuterol increases the production of histamine and IL-4 in mast cells.

BACKGROUND: Racemic albuterol is an equimolar mixture of (R)-albuterol and (S)-albuterol. Previous studies indicated that (S)-albuterol may exert proinflammatory effects. We investigated the effect of (S)-albuterol in the production of mast cell mediators such as histamine and interleukin (IL)-4. METHODS: Murine mast cells were either unstimulated or stimulated by IgE-receptor crosslinking. Both groups of mast cells were pretreated with either (R)- or (S)-albuterol. Histamine release and IL-4 secretion were measured by ELISA. Expression of L-histidine decarboxylase (L-HDC) and IL-4 was analyzed by semiquantitative reverse transcription-polymerase chain reaction. RESULTS: In the overnight IgE-stimulated group, secreted histamine and total histamine were approximately 19.9 and 18.3% greater in cells co-treated with (S)-albuterol than untreated cells, respectively (n = 4, p < 0.002, p < 0.02), whereas there was no significant difference between the cells treated with (R)-albuterol and untreated cells. When the IgE-stimulated cells were treated with (S)-albuterol for 6 and 24 h, histamine release was approximately 18.3 and 24% greater, respectively (n = 4, p < 0.01). L-HDC is an essential enzyme for synthesizing histamine and its message was significantly induced in mast cells treated with (S)-albuterol. Both IL-4 message and protein were also significantly increased after treatment with (S)-albuterol. In the overnight IgE-stimulated group, IL-4 secretion was increased by approximately 58.8% upon exposure to (S)-albuterol (n = 5, p < 0.01). (R)-albuterol had no effect on mast cell mediator release. CONCLUSION: (S)-albuterol may have adverse effects in asthma control by activating mast cells to produce inflammatory mediators such as histamine and IL-4.

Albuterol↗
PubMed2001

Tumor removal enhances immunity induced by B7.1.

Costimulation of tumor T cells by B7.1 has been shown to be important for eliciting cell-mediated anti-tumor immunity. We constructed a stable B7.1 gene transfectant of a poorly immunogenic murine sarcoma, Moloney murine sarcoma virus-induced tumor cell line (MMSV). This transfectant, MMSV-B7.1, failed to produce any tumor development in syngeneic mouse models. When MMSV-B7.1 was simultaneously injected with wild-type MMSV, about half of the coinjected mice remained tumor free and displayed an increase in T cell population, upregulation of the mRNA level of various cytokines such as IL-4, IL-5, IL-10, IL-13, IL-15 and IFN-gamma, and complete rejection of reinjected MMSV. To investigate whether MMSV-B7.1 demonstrates any vaccinal effect, the transfectant was injected following the surgical removal of the primary tumor mass. Following a re-challenge with wild-type MMSV, all vaccinated mice maintained their tumor free status and displayed a rapid recovery of down-regulated cytokine levels. The results suggest that B7.1 vaccination after tumor removal might be useful for the prevention of tumor recurrence.

Animals↗
PubMed2001

Strain distribution in the proximal human femur. An in vitro comparison in the intact femur and after insertion of reference and experimental femoral stems.

Six pairs of human cadaver femora were divided equally into two groups one of which received a non-cemented reference implant and the other a very short non-dependent experimental implant. Thirteen strain-gauge rosettes were attached to the external surface of each specimen and, during application of combined axial and torsional loads to the femoral head, the strains in both groups were measured. After the insertion of a non-cemented femoral component, the normal pattern of a progressive proximal-to-distal increase in strains was similar to that in the intact femur and the strain was maximum near the tip of the prosthesis. On the medial and lateral aspects of the proximal femur, the strains were greatly reduced after implantation of both types of implant. The pattern and magnitude of the strains, however, were closer to those in the intact femur after insertion of the experimental stem than in the reference stem. On the anterior and posterior aspects of the femur, implantation of both types of stem led to increased principal strains E1, E2 and E3. This was most pronounced for the experimental stem. Our findings suggest that the experimental stem, which has a more anatomical proximal fit without having a distal stem and cortex contact, can provide immediate postoperative stability. Pure proximal loading by the experimental stem in the metaphysis, reduction of excessive bending stiffness of the stem by tapering and the absence of contact between the stem and the distal cortex may reduce stress shielding, bone resorption and thigh pain.

Adult↗
PubMed2001

A comparison of polyethylene wear in hips with cobalt-chrome or zirconia heads. A prospective, randomised study.

We have reviewed 70 patients with bilateral simultaneous total hip arthroplasties to determine the rate of failure and to compare polyethylene wear and osteolysis between an implant with a cobalt-chrome head and Hylamer liner with that of a zirconia head and Hylamer liner. The mean thickness of the polyethylene liner was 11.0 mm (8.8 to 12.2) in the hip with a zirconia head and 10.7 mm (8.8 to 12.2) in that with a cobalt-chrome head. At follow-up at 6.4 years no acetabular or femoral component had been revised for aseptic loosening and no acetabular or femoral component was loose according to radiological criteria in both the cemented and cementless groups. The mean rate of linear wear and annual wear rate were highest in the 22 mm zirconia femoral head (1.25 mm (SD 1.05) and 0.21 mm (SD 0.18), respectively) and lowest in the 22 mm cobalt-chrome femoral head (0.70 mm (SD 0.39) and 0.12 mm (SD 0.07), respectively). The mean volumetric wear was highest in the 28 mm zirconia femoral head (730.79 mm ) and lowest in the 22 mm cobalt-chrome femoral head (264.67 mm3), but if the results were compared by size of the femoral head and type of material there was no statistical difference (p > 0.05). Sequential measurements of annual wear showed that the zirconia femoral head had a relatively higher rate of penetration than the cobalt-chrome head over the first three years; thereafter the rate of wear was reduced and compared favourably with that of cobalt-chrome heads. There was a statistically significant relationship between the wear of the polyethylene liner and the age of the patient, male gender and the degree of abduction angle of the cup, but not diagnosis, weight, hip score, range of movement, or amount of anteversion. Osteolysis was identified on both sides of the acetabulum in six patients (9%). Of 12 hips with acetabular osteolysis, six had a 28 mm cobalt-chrome femoral head and the remaining six a 28 mm zirconia head. Osteolysis was observed in zones 1A and 7A of the femur in two hips (3%) with a 28 mm zirconia head (cemented hip) and in four (6%) with a 28 mm cobalt-chrome femoral head (cementless hip). Our findings suggest that although the performance of a zirconia femoral head with a Hylamer liner was not statistically different from that of a cobalt-chrome femoral head and Hylamer liner, there was a trend for the zirconia head to be worse than the cobalt-chrome femoral head.

Adult↗
PubMed2001

Preoperative uterine artery embolization and evacuation in the management of cervical pregnancy: report of two cases.

Preoperative uterine artery embolization and cervical evacuation as conservative management of cervical pregnancy has been tried in recent years. However, cervical suturing, vasoconstrictor injection, or cervical ballooning was frequently used as an ancillary measures in those procedures in most of the previous studies. We report two cases of cervical pregnancy that were successfully treated with preoperative uterine artery embolization and removal of gestational material without ancillary procedures. Our therapeutic modality seems to be safe and effective for conservative management of cervical pregnancy.

Adult↗
PubMed2001

Experimental infection of Anopheles sinensis with Korean isolates of Plasmodium vivax.

The objectives of the present study were to (1) determine the susceptibility of Anopheles sinensis to Korean isolates of Plasmodium vivax, (2) establish a method to collect large quantities of P. vivax sporozoites for use as antigen in seroepidemiological studies, and (3) investigate the characteristics of Korean isolates of P. vivax sporozoites. Females of Anopheles sinensis were collected at non-epidemic area, Seokwha-ri, Cheongwon-gun and Chungcheongbuk-do using tent-trap methods coupled with dry ice. The females were artificially infected with gametocytes of P. vivax using blood obtained from P. vivax malaria patients. Individual mosquitoes were infected using either a parafilm-covered glass feeding apparatus or were allowed to feed on naturally infected volunteers. Mosquitoes were sacrificed between 16 and 18 days post-feeding and an enzyme-linked immunosorbent assay (ELISA) was used to detect sporozoites. Four (33.4%) of 12 mosquitoes, which were fed on naturally infected volunteers directly, were positive for sporozoites. In cases, the mosquitoes allowed to feed on whole blood which were extract from three different patients with heparin treated vacuutainers using a parafilm-covered glass apparatus. Two of 55 (3.6%) were positive which blood sample was maintained at room temperature for 8 hours, 1 of 68 (1.5%) was positive which blood was maintained at 4 degrees C for 24 hours and 1 of 47 (2.3%) was positive at 4 degrees C for 48 hours. The mean number of sporozoites was estimated about 818 (n = 8; range of 648-1,056) based on optical density values of ELISA.

Animals↗
PubMed2001

Squamous cell carcinoma of the cornea.

In this paper, a case of corneal squamous cell carcinoma is reported. Invasive squamous cell carcinoma of the cornea is a rare disorder and has not been previously described in the Korean literature. In this case, the invasive squamous cell carcinoma of the cornea was treated by complete excision and cryotherapy. No evidence of metastasis or recurrence has been found since the procedure. Complete excision and adjunctive cryotherapy has become the treatment of choice because of the higher recurrence rate following a simple excision.

Aged↗