Biomedical subjects

S C Kim

Publications and source records attributed to S C Kim.

316 records · Page 18Linked to original sources

PubMedDate not supplied

Formation and emission status of PCDDs/PCDFs in municipal solid waste incinerators in Korea.

This study was carried out to examine the formation and the emission status of polychlorinated dibenzo-p-dioxins/polychlorinated dibenzofurans (PCDDs/PCDFs) in the flue gases of commercial-scale municipal solid waste (MSW) incinerators, and thus to provide the engineering data for the reduction of PCDDs/PCDFs emitted from MSW incinerators. The formation concentrations of the PCDDs/PCDFs generated at the outlet of waste heat boilers (WHB) were in the range of 1.18-29.61 ng-TEQ/N m3 (average 5.75 ng-TEQ/N m3), while the emission concentrations at the stacks were in the range of 0.026-4.548 ng-TEQ/N m3 (average 0.924 ng-TEQ/N m3). Two major 2,3,7,8-substituted congeners were 2,3,4,7,8-PeCDF and 2,3,4,6,7,8-HxCDF, and their concentrations were up to 50% and 64% of total TEQ values at the outlet of WHB and the stack, respectively. From the results of multi-regression analysis, the formation concentration of PCDDs/PCDFs could be predicted as follows with the correlation factor of r2 = 0.962: PCDDs/PCDFs (ng-TEQ/N m3) = 3.036 (Cl) + 0.094 (T1) - 0.472 (Combustibles) + 0.059 (CO) - 0.039 (THC) - 3.366 (H) + 22.157, where T1 (degrees C) is the temperature at the outlet of the WHB. Cl, Combustibles and H are given as percentages and the others are in parts per million.

Air Pollutants↗

PubMedDate not supplied

Removal efficiencies of PCDDs/PCDFs by air pollution control devices in municipal solid waste incinerators.

Removal efficiencies of polychlorinated dibenzo-p-dioxins/polychlorinated dibenzofurans (PCDDs/PCDFs) by air pollution control devices (APCDs) in the commercial-scale municipal solid waste (MSW) incinerators with a capacity of above 200 ton/day were evaluated. The removal efficiencies of PCDDs/PCDFs were up to 95% when the activated carbon (AC) was injected in front of electrostatic precipitator (EP). Spray dryer absorber/bag filter (SDA/BF) had high removal efficiency (99%)) of PCDDs/PCDFs when a mixture of lime and AC was sprayed into the SDA. When the AC was not added in scrubbing solution, the whole congeners of PCDDs/PCDFs were enriched in the wet scrubber (WS) with negative removal efficiencies of -25% to -5731%. Discharge of PCDDs/PCDFs was decreased with increasing the proportions of AC added in scrubbing solution. Selective catalytic reduction (SCR) system had the removal efficiencies of up to 93% during the test operation.

Air Pollution↗

PubMedDate not supplied

Mullerian adenosarcoma with sarcomatous overgrowth of the cervix presenting as cervical polyp: a case report and review of the literature.

An aggressive variant of adenosarcoma, mullerian adenosarcoma with sarcomatous overgrowth (MASO) in the cervix is extremely rare. This variant contains obvious, high-grade sarcoma in addition to a low-grade form. In this report, we describe a case of MASO of the uterine cervix and review the clinical and pathological features of these tumors. The patient was a 37-year-old woman with a cervical polypoid mass, which was morphologically considered as a benign endocervical polyp. Microscopically, polypoid cervical mass showed diffuse and dense malignant spindle cell proliferation around the benign endocervical glands and also an area of markedly anaplastic and pleomorphic spindle cell proliferation, so called, sarcomatous overgrowth. Total abdominal hysterectomy and bilateral salpingo-oophorectomy with pelvic lymph node dissection were performed. The patient has been followed-up and neither chemotherapy nor other adjuvant therapies have been administered. At present, she has been clinically free of disease for 9 months since she received surgery. It is extremely rare that MASO of the uterine cervix is presented in premenopausal woman. Gynecologists and pathologists should be aware of the difficulties associated with a delay in the diagnosis of MASO when the tumor is present as a benign looking cervical polyp.

Adenosarcoma↗

PubMedDate not supplied

CAG repeat length in exon 1 of the androgen receptor gene is related to age of diagnosis but not germ line BRCA1 mutation status in ovarian cancer.

It has been postulated that androgens, through their interaction with androgen receptors (AR), may play an important role in the development of ovarian cancer. Exon 1 of the AR gene contains three highly polymorphic trinucleotide repeats. The length of the (CAG)n repeat segment 1 is inversely correlated with the transactivation function of the AR. Recent studies have shown that BRCA1 may function as an AR coregulator or coactivator and play positive roles in androgen-induced cell death in cancer cells as well as other androgen/AR target organs. We hypothesize that the AR gene, involved in endocrine signaling, may modify BRCA1-associated ovarian cancer risk. To test this hypothesis, potential associations between the (CAG)n repeat length, germ line BRCA1 mutation status, and age of diagnosis for ovarian cancer were investigated. One hundred and eleven ovarian cancer patients (27 hereditary and 84 sporadic) were included. All the cases were allelotyped for CAG repeat length and genotyped for mutations in the BRCA1 gene by direct sequencing. No association between CAG repeat length and BRCA1 mutation status was identified. Furthermore, there were no differences between hereditary and sporadic ovarian cancer in the number of (CAG)n repeats of the short allele (P= 0.336), long allele (P= 0.875), or average allele length (P= 0.550). However, ovarian cancer patients from both groups (hereditary and sporadic) who carried any AR allele of (CAG)n < or = 22 repeats were diagnosed on average 8.17 years (95% confidence interval [1.3, 15.0]) earlier than the patients whose shortest AR allele (CAG)n was >22 (P= 0.020). In conclusion, it is suggested that the CAG repeat length in AR exon 1 may affect the age of diagnosis of ovarian cancer but does so independent of germ line BRCA1 carrier status.

Adult↗

PubMedDate not supplied

Electronmicroscopic observation of the basement membrane zone in focal dermal hypoplasia.

A 3-month-old boy had reticulated achromic and atrophic skin lesions on the right buttock and thigh, as well as partial syndactyly of the third and fourth toes of the right foot. With hematoxylin and eosin stain, an epidermal defect, abnormally located fat cell lobules, and absence of the upper and midportions of the dermis were observed, conforming to a typical histopathologic picture of focal dermal hypoplasia. Electron microscopic examination of the atrophic site showed loose collagen bundles, collagen fibers with loss of regular bands, abnormal fibroblasts, and disruption of the basement membrane zone. These defects in the basement membrane zone strongly suggest that abnormal formation of type IV collagen is associated with focal dermal hypoplasia, and that this abnormal formation of collagen is correlated with the clinical sign of skin atrophy.

Atrophy↗

PubMedDate not supplied

Pneumatization of the sphenoid sinus in children evaluated by magnetic resonance imaging.

Previous studies concerned with the normal development of the sphenoid sinus have reported that the onset of initial pneumatization varies from 6 months to 4 years of life, and that the pneumatization is completed by 12 to 14 years of age. This study was designed to evaluate the age-related development of the sphenoid sinus pneumatization in children using magnetic resonance (MR) imaging technique. MR images of the sphenoid sinus in 152 children, ages 2 months to 163 months, were retrospectively reviewed. The degree of pneumatization was classified into four grades as 0, 1, 2, and 3 in axial images, and into five grades as 0, 1, 2, 3, and 4 in sagittal images. The numbers of grades were age-matched in the studied children. The pneumatized sphenoid sinus was identifiable as early as 2 months of age on axial image, and 4 months on sagittal image. Pneumatized sphenoid sinuses were identified in 100% of the subjects studied at the age of 3 years on axial image, and 6 years on sagittal image. All the children over 9 years old showed pneumatization of grade 2 or more both on axial and sagittal images. The results of this study may indicate that the sphenoid sinus begins and completes pneumatization earlier than previously described.

Adolescent↗

PubMedDate not supplied

Characteristics of viable Brevibacterium linens cells, methionine and cysteine in milkfat-coated microcapsules.

The potential for microencapsulation of viable Brevibacterium linens with methionine or cysteine in milkfat to produce sulphur compounds was examined in this study. More than 80 per cent of B. linens cells were encapsulated and then numbers inside capsules increased about three-fold during 48 h at 26 degrees C under anaerobic conditions before a slow decline. Most of micro-organisms (7 x 10(7)/ml) were still viable in the capsules after 15 days. More than 90 per cent of cysteine and methionine were encapsulated and 90, 80 and 60 per cent of the encapsulated amino acids were maintained in the capsules at 4, 12 and 26 degrees C, respectively, after 24 h. Most of the cysteine was oxidized to cystine during microencapsulation but still available to micro-organisms whereas methionine remained in the reduced form. Partition coefficients of methionine and cysteine to milkfat were 0.117 and 0.275, respectively, indicating that most of these substrates would be available to cells of B. linens in the capsules.

Brevibacterium↗

PubMedDate not supplied

Production of hydrogen sulphide in milkfat-coated microcapsules containing Brevibacterium linens and cysteine.

Milkfat-coated microcapsules containing Brevibacterium linens and cysteine were used to produce hydrogen sulphide, one of Cheddar cheese flavour compounds. Hydrogen sulphide production was substantially reduced and delayed in the encapsulated system as compared with that of the unencapsulated system. Hydrogen sulphide was not produced aerobically whereas substantial amounts of hydrogen sulphide were produced in a nitrogen purged system. The inhibitory effect of the initial aerobic condition disappeared after 8 days of incubation. In spite of the lag in hydrogen sulphide production under aerobic conditions almost the same amount of hydrogen sulphide was produced in oxygen purged samples as in the nitrogen purged samples after 10 days of incubation. Moderate heat treatment (2 min at 58 degrees C) of cell suspension-milkfat-emulsion increased subsequent hydrogen sulphide production. The optimum pH and temperature for hydrogen sulphide production from cysteine by Brevibacterium linens were 6 degrees C and 32 degrees C, respectively. Antioxidants BHT, BHA and ascorbic acid had negligible effects on production of hydrogen sulphide in the encapsulated system.

Animals↗

PubMedDate not supplied

Involvement of endothelial nitric oxide synthase in the impaired endothelium-dependent relaxation of cavernous smooth muscle in hypercholesterolemic rabbit.

The present study was designed to evaluate whether functional impairment and/or protein expression of constitutive nitric oxide synthase (cNOS; endothelial NOS [eNOS] and neuronal NOS[nNOS]) was involved in impairment of endothelium-dependent relaxation of cavernous smooth muscle in hypercholesterolemic rabbits. New Zealand White rabbits were randomly divided into control and experimental groups. The control group (n=20) received a regular diet, while the two experimental groups (n=20 for each) were fed a 2% cholesterol diet for 4 and 8 weeks, respectively. We conducted isometric tension studies with endothelium-dependent and endothelium-independent vasodilators with or without preincubation with L-arginine and nonadrenergic, noncholinergic (NANC)-selective electrical field stimulation on isolated strips of corpus cavernosum. Expression of cNOS (eNOS and nNOS) protein was assessed by Western blot analysis. cNOS activities in both cytosolic and particulate fractions were measured by determining the conversion of L-[U-14C] arginine to L-[U-14C] citrulline. Blood levels of cholesterol were significantly higher (P < 0.01) in the experimental groups than in the control group. The relaxation responses to endothelium-dependent agents (acetylcholine and adenosine 5'-diphosphate [ADP]) were significantly reduced (P < 0.05) in both experimental groups, regardless of their incubation with L-arginine, compared with the control group. However, no differences were found among the three groups in the relaxation response to endothelium-independent agents (papaverine and nitroprusside) and to NANC-selective electrical field stimulation. There was no difference in immunoreactive nNOS from cytosolic and particulate fractions between the cavernous tissues of the control and experimental groups. nNOS protein levels in the particulate fractions were markedly lower than in the cytosolic fractions. The particulate cNOS activity was significantly decreased (P < 0.05) in the experimental groups compared with the control group, while the cytosolic cNOS activity in the experimental groups was not different from that found in the control group. Therefore, it is concluded that functional impairment of eNOS, rather than of nNOS, may lead to impairment of cavernous smooth muscle relaxation in response to endothelium-mediated stimuli in hypercholesterolemic rabbits.

Animals↗

PubMedDate not supplied

Lichen planus pemphigoides with circulating autoantibodies against 200 and 180 kDa epidermal antigens.

We describe a case of lichen planus pemphigoides with circulating autoantibodies against 200 and 180 kDa epidermal antigens. A 24-year-old man presented pruritic erythematous patches with occasional central blister formation on the face, neck, and trunk and erythematous hyperkeratotic patches on the elbows and feet for 10 months. Histopathological findings of the neck and plantar lesions were consistent with lichen planus. Direct immunofluorescence studies from both lesions showed a linear deposition of IgG and C3 and cytoid bodies along the basement membrane zone. Indirect immunofluorescence studies demonstrated circulating IgG antibodies deposited on the epidermal side of salt-split skin. Immunoblot analysis using epidermal extract showed that the patient's serum reacted with 180 kDa bullous pemphigoid antigen (BPAG2) and a 200 kDa antigen. The cutaneous lesions almost cleared with a low dose of prednisolone and acitretin.

Adult↗