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Tseng YJ, Chang HH, Shiau CY, Chung WY, Pan DH, Chu WC. PC-based gamma knife radiosurgery dose calculation. IEEE ENGINEERING IN MEDICINE AND BIOLOGY MAGAZINE : THE QUARTERLY MAGAZINE OF THE ENGINEERING IN MEDICINE & BIOLOGY SOCIETY 2004; 22:92-107. [PMID: 14699942 DOI: 10.1109/memb.2003.1256278] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Molassiotis A, Lopez-Nahas V, Chung WY, Lam SW. A pilot study of the effects of a behavioural intervention on treatment adherence in HIV-infected patients. AIDS Care 2003; 15:125-35. [PMID: 12655840 DOI: 10.1080/0954012021000039833] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
A pilot study was carried out in a group of six HIV-infected non-adherent men testing the effects of a behavioural medication management intervention on adherence with antiretroviral drugs. The study was prospective, using a one-group repeated-measures design. Adherence was measured using two self-reports. The intervention was a behaviourally-based programme that lasted for three months and included individualized education about antiretroviral medication and their side effects; positive reinforcement and encouragement; individualized counselling weekly; follow-up calls; and lifestyle assessment and the identification of adherence barriers. Assessments were carried out at recruitment, immediately after the initiation of the intervention, one month, three months and six months later. Results suggested that the intervention enhanced adherence rates from a mean percentage of 80.27 at baseline to a mean of 97.5% at the end of follow-up (six months time point). Similar improvement was observed in the scores of the scale measuring adherence difficulties. Further, CD4+ counts also slightly improved. Interviews with four of the participants at the end of the study highlighted the problems experienced by patients in taking their medication and supported the usefulness of the intervention. Because of the complexity of the factors behind adherence, it is important that patients are supported with individualized medication management programmes.
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Abstract
We recently developed a new surgical technique for carrying out thyroidectomy, to minimize tissue trauma by obviating unnecessary neck exploration. This report describes our technique of performing minimally invasive open thyroidectomy and compares the results with those of conventional thyroidectomy. Minimally invasive open thyroidectomy was performed by making a small skin incision, 3.0-4.5cm long, and approaching the thyroid directly via a transverse division of the strap muscles without raising skin flaps. The outcomes of 466 patients who underwent a minimally invasive open thyroidectomy were retrospectively compared with those of 437 patients who underwent conventional thyroidectomy for various types of thyroid nodules. There was no significant difference in the extent of surgery between the group of patients who underwent minimally invasive thyroidectomy and the group of patients who underwent conventional thyroidectomy. However, the length of the skin incision, at 3.7 +/- 0.7 vs 9.6 +/- 3.3 cm, respectively, operative time, at 57.6 +/- 11.7 vs 85.2 +/- 32.3 min, respectively, blood loss, at 18.4 +/- 15.3 vs 43.1 +/- 21.8 ml, respectively, and hospital stay, at 1.6 +/- 0.5 vs 4.3 +/- 1.6 days, respectively, were significantly reduced in the minimally invasive open thyroidectomy group (P < 0.05). Moreover, the number of patients who required postoperative analgesia was significantly less in the minimally invasive open thyroidectomy group. These results show that minimally invasive open thyroidectomy provides surgeons with a clear operative field, and that it has proven to be simple, safe, and practical for selected patients.
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Tseng YJ, Chu WC, Chung WY, Guo WY, Kao YH, Wang J, Huang SC. The role of dose distribution gradient in the observed ferric ion diffusion time scale in MRI-Fricke-infused gel dosimetry. Magn Reson Imaging 2002; 20:495-502. [PMID: 12361797 DOI: 10.1016/s0730-725x(02)00522-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Ferric ion diffusion is a detrimental factor in MRI-Fricke-infused gel dosimetry. In this study, a novel approach involving MR image subtraction and a fast image-based dosimetry technique to study ferric ion diffusion effects is presented. The fast image-based approach allows studying dose profile degradation within minutes post-irradiation. The relationship between the rate of dose profile deterioration and dose distribution gradients can be elucidated with the improved imaging temporal resolution also. Our results showed that for a dose distribution with gradient 4 Gy/mm or higher, ferric ion diffusion causes apparent dose profile degradation in 0.5-1 h post-irradiation. For a gradual dose gradient change of 2.1 Gy/mm or smaller, dose profile degradation appears insignificant for a two-hour elapsed diffusion time. These observations agree well with the theoretical analysis of a square dependence between dose profile degradation and dose distribution gradient. Because all stereotactic radiosurgery procedures produce steep dose distributions and because the ideal "snapshot" of MR scanning cannot be achieved, knowledge of the ferric ion diffusion time scale is important in experimental designs in order to avoid potential measurement errors in MRI-Fricke-agarose gel dosimetry.
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Molassiotis A, Callaghan P, Twinn SF, Lam SW, Chung WY, Li CK. A pilot study of the effects of cognitive-behavioral group therapy and peer support/counseling in decreasing psychologic distress and improving quality of life in Chinese patients with symptomatic HIV disease. AIDS Patient Care STDS 2002; 16:83-96. [PMID: 11874640 DOI: 10.1089/10872910252806135] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Forty-six Chinese patients with symptomatic human immunodeficiency virus (HIV) participated in a comparative study assessing the effectiveness of cognitive-behavioral group therapy (CBT) and peer support/counseling group therapy (PSC) in relation to improving mood and quality of life and decreasing uncertainty in illness as compared to a group receiving routine treatment with no formal psychosocial intervention. The CBT group consisted of 10 subjects, the PSC group of 10 subjects, and the comparison group of 26 subjects. There was a 24% attrition rate. The intervention groups received 12 weekly sessions of therapy over 3 months. Assessment of mood states was carried out before randomization (baseline data), immediately postintervention (3-month time point) and followed-up 3 months later (6-month time point). Assessment of quality of life and uncertainty in illness was carried out before randomization and at the 6-month follow-up time point. Results indicated that the mood of the participants in the CBT group improved in terms of anger, tension-anxiety, depression, confusion, and overall mood. The quality of life in this group was significantly improved compared to the other two groups, as was uncertainty in illness. In the PSC group a worsening of psychologic functioning was observed immediately postintervention, but this picture dramatically improved at the follow-up assessment with improvements of up to 34%. Quality of life also improved over time in this group by almost 5%, but results did not reach statistical significance. This study demonstrated that psychologic interventions could decrease psychologic distress and improve quality of life in symptomatic HIV patients, indicating their use should be incorporated in the management of care of people living with HIV/AIDS.
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Chung WY, Chang HS, Kim EK, Park CS. Ultrasonographic mass screening for thyroid carcinoma: a study in women scheduled to undergo a breast examination. Surg Today 2002; 31:763-7. [PMID: 11686552 DOI: 10.1007/s005950170044] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
This study was carried out to clarify the sensitivity of ultrasonographic mass screening for thyroid carcinoma. Between December 1997 and July 1998, a total of 1401 subjects who were scheduled to undergo either a breast examination or a follow-up examination for breast cancer were enrolled in this study. Patients with thyroid nodules were classified into two groups according to their potential risk for malignancy based on the ultrasonographic findings. Ultrasonographic high-risk patients for thyroid cancer underwent an ultrasound guided fine-needle aspiration biopsy (FNAB) and were advised to undergo a thyroidectomy based on the FNAB results. The characteristics of the thyroid cancer patients detected by mass screening were then compared with those of 106 consecutive female patients with clinical thyroid cancer during the same period. Thyroid nodules were detected in 353 (25.2%) of the subjects, 94 (26.6%) of whom were placed in the high-risk group for thyroid cancer. Among the 94 high-risk patients, 43 underwent a thyroidectomy and 37 turned out to have thyroid carcinomas. The detection rate for thyroid cancer was 2.6% for all subjects. The tumor size was significantly smaller than that of the clinically detected cancer group (P < 0.05). Ultrasonographic mass screening for thyroid carcinoma in women who require breast examinations is thus considered to be effective for the detection of subclinical thyroid carcinoma.
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Hutter PA, Chung WY, Nunumete DC, Hitchcock JF, Bennink GB, Meijboom EJ. [Arterial-switch operation for transposition of the great vessels; good results in the Wilhelmina Children's Hospital, Utrecht, 1977-2000]. NEDERLANDS TIJDSCHRIFT VOOR GENEESKUNDE 2001; 145:2534-8. [PMID: 11793830] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
Abstract
OBJECTIVE To examine the results of the arterial switch operation which is used to correct the transposition of the great arteries. DESIGN Descriptive. METHOD In the period May 1977-October 2000 195 patients at the Wilhelmina Children's Hospital in Utrecht, the Netherlands, underwent an arterial switch operation. The patient group consisted of 132 boys and 63 girls, with a median age at surgery of 8 days (range: 0-1976). In accordance with the protocol, the postoperative follow-up consisted of echocardiography and an ECG. Further investigations were performed on indication. Additional data were collected from the status reports. The mean follow-up was 8.0 years (range: 0.04-22.17). RESULTS The overall peri-operative mortality was 15% (30/195). Initially this figure was about 50%, in the 1980s it was 15% and from 1996 onwards it was 4%. Of the 151 surviving and traceable patients, 2 patients died years later (1.3%). Of the remaining 149 patients, 145 were classified in New York Heart Association class I and 4 in class II. Due to pulmonary stenosis, 45 reinterventions were required in 26 patients (/149; 17%). Left ventricle dysfunction occurred in 5 patients (3%), arrhythmias in 5 patients and aorta abnormalities in 5 patients. Coronary artery abnormalities were found in 5 of the 61 patients who underwent angiography (8%). CONCLUSION Peri-operative mortality decreased to 4% and late mortality was 1.3%. The long-term clinical outcome of the arterial switch operation was good. Morbidity was predominantly caused by pulmonary stenosis and late coronary obstruction.
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Abstract
After anterior cruciate ligament reconstruction with autologous patellar tendon, 23 patients who had clinically stable knees were studied prospectively with sequential magnetic resonance imaging 1, 2, 3, 6, and 12 months after surgery. The images of the anterior cruciate ligament were obtained with a 1.5 tesla magnetic resonance scanner in the oblique sagittal, coronal, and oblique axial planes. The cross-sectional area and signal intensity on the reconstructed anterior cruciate ligament were measured in an oblique axial image. The usefulness of the oblique axial image in evaluating the integrity of the reconstructed anterior cruciate ligament was seen. The result showed that the diameter of the graft increased by 70% of its initial size and the signal intensity of the reconstructed graft also showed a tendency to increase. In three patients, there was discontinuity in the graft direction on the oblique sagittal image, but on the oblique axial image there was no evidence of reconstructed anterior cruciate ligament rupture in the sequential images. This shows the value of the oblique axial image in evaluating the integrity of the reconstructed anterior cruciate ligament. Also, sufficient notchplasty in anterior cruciate ligament reconstruction may be needed to prevent graft impingement.
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Choy CK, Cho P, Chung WY, Benzie IF. Water-soluble antioxidants in human tears: effect of the collection method. Invest Ophthalmol Vis Sci 2001; 42:3130-4. [PMID: 11726613] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/22/2023] Open
Abstract
PURPOSE To resolve differences in published data on tear antioxidant levels by comparing the concentration of water-soluble antioxidants in human reflex tears collected by capillary tube and by the Schirmer strip collection method and in basal and reflex tears collected using the Schirmer strip method. METHODS Yawn-induced reflex tears (collected simultaneously by capillary tubes and by Schirmer strips) and basal tears (by Schirmer strips and using local anesthetic) were collected from 12 healthy subjects. Tear cysteine, ascorbate, glutathione, urate, and tyrosine were measured by high-performance liquid chromatography within a few minutes of collection. RESULTS Cysteine, ascorbate, glutathione, and tyrosine were 5 to 10 times higher (P < 0.01) in both reflex and basal tears collected by Schirmer strip compared with reflex tears collected by capillary tube from the same subject. Urate levels were slightly but nonsignificantly higher in Schirmer strip samples (P > 0.05). CONCLUSIONS The conflict in published data on tear antioxidants is caused by differences in collection methods. With the exception of urate, antioxidants accumulate to very high levels in corneal cells. Spuriously high antioxidant levels in tears collected using Schirmer strips, therefore, are most probably caused by contamination with intracellular constituents. The capillary tube collection method is proposed as the method of choice for reflex tear collection for biochemical studies. This less-invasive method facilitates the evaluation of tear antioxidant levels as a biomonitoring tool for corneal health. Although moderately increased antioxidant levels may be beneficial, the authors hypothesize that marked increases may indicate damage to the ocular surface.
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Chung WY, Chung JK, Szeto YT, Tomlinson B, Benzie IF. Plasma ascorbic acid: measurement, stability and clinical utility revisited. Clin Biochem 2001; 34:623-7. [PMID: 11849621 DOI: 10.1016/s0009-9120(01)00270-3] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
AIMS To compare plasma ascorbic acid results by the colorimetric FRASC (Ferric Reducing/Antioxidant and Ascorbic Acid) assay and a reference HPLC method; to re-examine plasma ascorbic acid stability, and anticoagulant effect. DESIGN AND METHODS For method comparison, 31 plasma samples were tested by both methods. For stability, matching EDTA, heparin, citrate and fluoride/oxalate plasma, stored under different conditions of time and temperature, was measured. RESULTS FRASC is an acceptable alternative to HPLC for plasma ascorbic acid: precision, limit of detection and recovery were similar, and results by the two methods were indistinguishable: mean (95% CI) difference:1.8 (-1.1-4.6; n = 31) micromol/L. Ascorbic acid was most stable in heparinized plasma. Marked loss (p < 0.05) in EDTA plasma occurred within 30 min of blood collection. CONCLUSIONS FRASC offers a speedy and reliable alternative to HPLC for plasma ascorbic acid. Heparin is proposed as the anticoagulant of choice; loss of ascorbic acid is rapid in EDTA plasma ex vivo.
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Tam LS, Li EK, Benzie IF, Lam CW, Arumanayagam M, Chung WY, Tomlinson B. Metabolic abnormalities associated with microalbuminuria in systemic lupus erythematosus. Rheumatology (Oxford) 2001; 40:1193-4. [PMID: 11600754 DOI: 10.1093/rheumatology/40.10.1193-a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Chung WY, Jung YJ, Surh YJ, Lee SS, Park KK. Antioxidative and antitumor promoting effects of [6]-paradol and its homologs. Mutat Res 2001; 496:199-206. [PMID: 11551496 DOI: 10.1016/s1383-5718(01)00221-2] [Citation(s) in RCA: 87] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Recently, considerable attention is focused on anti-carcinogenic phytochemicals, particularly those derived from medicinal or edible plants. [6]-Paradol, a pungent phenolic compound present in certain Zingiberaceae plants, is known to have antimicrobial and analgesic activities. The compound has been reported to attenuate promotion of skin carcinogenesis and TPA-induced ear edema in female ICR mice, and to induce apoptosis in cultured human promyelocytic leukemia (HL-60) cells. In this study, we performed several biochemical studies to evaluate and compare the cancer chemopreventive potential of [6]-paradol and its synthetic derivatives. [6]-Paradol and its synthetic nonpungent analog, [6]-dehydroparadol significantly decreased the incidence and the multiplicity of skin tumors initiated by 7,12-dimethylbenz[a]anthracene (DMBA) and promoted by 12-O-tetradecanoylphorbol-13-acetate (TPA). Topical application of [6]-paradol and its derivatives inhibited TPA-induced ear edema and H(2)O(2) production and myeloperoxidase activity in the dorsal skin of mice. Induction of TPA-induced mouse epidermal ornithine decarboxylase (ODC) activity and H(2)O(2)- and UV-induced formation of oxidized DNA bases in vitro were also attenuated by the above compounds. These results indicate that [6]-paradol and its derivatives possess the cancer chemopreventive potential.
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Huang MC, Lee LS, Ho DM, Cheng H, Chung WY, Huang CI, Hsiao CY, Pan DH. A metastatic pituitary carcinoid tumor successfully treated with gamma knife radiosurgery. ZHONGHUA YI XUE ZA ZHI = CHINESE MEDICAL JOURNAL; FREE CHINA ED 2001; 64:414-8. [PMID: 11584580] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/21/2023]
Abstract
Intracranial metastasis occurs in a certain number of patients with carcinoid tumor. However, carcinoid tumor with metastasis to the pituitary gland is extremely rare. Up to the present, no effective treatment for either a metastatic intracranial carcinoid tumor or a metastatic pituitary lesion of any origin has been documented. We have treated a case of metastatic carcinoid tumor of the pituitary gland with transsphenoidal tumor resection followed by gamma knife radiosurgery. A 59-year-old man presented with headache and left oculomotor palsy. He was treated at the same hospital for bronchial atypical carcinoid tumor one and a half years ago. Magnetic resonance image of the brain showed a pituitary tumor. There were no signs of recurrent or metastatic lesion elsewhere despite thorough investigation. Transsphenoidal approach for removal of tumor was done and the pathology turned out to be a metastatic carcinoid tumor. Subsequent gamma knife radiosurgery was given for residual tumor. The oculomotor palsy improved after radiosurgery. No neurological deficit occurred. Follow-up CT scan of the brain showed complete resolution of the tumor. We concluded that gamma knife radiosurgery could be used to treat a metastatic intracranial carcinoid tumor. It can also be used to treat a metastatic lesion of the pituitary gland without causing neurological deficit.
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Ban E, Choi OK, Chung WY, Park CS, Yoo EA, Chung BC, Yoo YS. Influence of buffer composition and sample pretreatment on efficiency separation for monitoring neuropeptides in plasma using capillary electrophoresis. Electrophoresis 2001; 22:2173-8. [PMID: 11504049 DOI: 10.1002/1522-2683(20017)22:11<2173::aid-elps2173>3.0.co;2-8] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
More efficient and faster separation conditions for qualitative as well as quantitative analysis of neuropeptides in human plasma using capillary zone electrophoresis (CZE) have been developed. The analysis method for neuropeptides has been improved specifically to study thyroid hormone related neuropetides for the regulation of thyroid disease. In this study, we investigated the pretreatment methods, composition of the running buffer and rinsing procedures between runs in order to obtain more sensitive and faster separation of trace neuropeptides in plasma by CZE. The tested neuropeptides were somatostatin (SOMA), vasopressin (VP), neurotensin (NT), and thyrotropin-releasing hormone (TRH). Plasma samples were pretreated by deproteinization and solid-phase extraction method. The fraction of neuropeptides was reconstituted in 40% acetonitrile followed by ultrafiltration, and then analyzed by CZE. Resolution and sensitivity was improved using the separation buffer composition with 100 mM Tris-phosphate buffer (pH 2.0) while the sensitivity was further improved via a stacking method using the sample buffer of 40% acetonitrile. These sample pretreatment methods and buffer condition permit quantitative analysis on tested neuropeptides at the 20 ng/mL level. The rinsing procedures between runs using 90% ethanol dramatically shortened the rinsing time to 30 min.
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Abstract
A 54-year-old woman was admitted to our hospital complaining of postcoital bleeding. Sonography of the abdomen showed a 8.2 x 8.9 cm-sized solid heterogeneous mass occupying the cul-de-sac, which appeared to be in no way connected with the ovary. On exploratory laparotomy, the tumor mass protruded from the posterolateral retroperitoneum of the pelvic cavity and severely replaced the uterus and adnexa with the outer surface being grossly intact. It grossly measured 10 cm in maximal diameter. The histologic features closely resembled those of ovarian granulosa cell tumor. The primary extraovarian granulosa cell tumor is extremely rare such that in the English literature only 7 cases have been reported to date. Of those granulosa cell tumors are especially rare and only two cases have been reported to arise from retroperitoneum. We herein present a case of retroperitoneal granulosa cell tumor with special regard to differential diagnosis from other solid tumors with similar histology.
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Sohn DW, Chung WY, Chai IH, Zo JH, Lee MM, Park YB, Choi YS, Lee YW. Mitral annulus velocity in the noninvasive estimation of left ventricular peak dP/dt. Am J Cardiol 2001; 87:933-6. [PMID: 11274960 DOI: 10.1016/s0002-9149(00)01546-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Yin LT, Chou JC, Chung WY, Sun TP, Hsiung SK. Characteristics of silicon nitride after O2 plasma surface treatment for pH-ISFET applications. IEEE Trans Biomed Eng 2001; 48:340-4. [PMID: 11327502 DOI: 10.1109/10.914797] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Silicon nitride (Si3N4) sensing gate pH-ion-selective field effect transistors (ISFETs) were treated by 2.54-GHz microwave O2 plasma, the results show the ISFET sensitivity has an advantage up to 24% increment after the plasma treatment. Electron spectroscopy for chemical analysis (ESCA) is used to make sure that the plasma treatment is not just a native oxide cleaning procedure. The samples, which were immobilized with glutaraldehyde used as a bifunctional reagent and 3-aminopropyItriethoxysilane used as an adhesion promoter were studied. The binding force between the glucose oxidase and glutaraldehyde immobilized samples, and the element concentrations of nitrogen in 3-aminopropyltriethoxysilane immobilized samples are higher which were treated by plasma.
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Chung WY, Lee JM, Lee WY, Surh YJ, Park KK. Protective effects of hemin and tetrakis(4-benzoic acid)porphyrin on bacterial mutagenesis and mouse skin carcinogenesis induced by 7, 12-dimethylbenz[a]anthracene. Mutat Res 2000; 472:139-45. [PMID: 11113706 DOI: 10.1016/s1383-5718(00)00137-6] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Porphyrins which are widespread in nature can interfere with the actions of certain carcinogens and mutagens, and have also been used clinically in photodynamic therapy (PDT) of tumors. Porphyrins such as chlorophyll, chlorophyllin (CHL) and hemin are known to inactivate various mutagens by forming complexes with them. Tetrakis(4-benzoic acid)porphyrin (TBAP) has been developed as a photosensitizer for PDT and its metal complex, MnTBAP has been shown to be efficacious in a variety of in vitro and in vivo oxidative stress models of human diseases. In the present study, we have found that TBAP and hemin exert concentration-related inhibition of his(+) reversion in Salmonella typhimurium TA100 induced by 7, 12-dimethylbenz[a]anthracene (DMBA), and significantly reduced both incidence and multiplicity of skin tumors when topically applied prior to treatment of 12-O-tetradecanoylphorbol-13-acetate in female ICR mice. Covalent DNA binding of DMBA in mouse skin was also significantly inhibited by topical application of TBAP or hemin as well as CHL. These results suggest the chemopreventive potential of compounds containing a porphyrin nucleus.
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Chung WY, Benzie IF. Probe-assisted flow cytometric analysis of erythrocyte membrane response to site-specific oxidant stress. CYTOMETRY 2000; 40:182-8. [PMID: 10878560 DOI: 10.1002/1097-0320(20000701)40:3<182::aid-cyto2>3.0.co;2-g] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
BACKGROUND Probe-assisted flow cytometry was used to monitor the response of membranes of living cells to oxidant stress in the presence and absence of antioxidants. Test conditions (fluorophore loading, oxidant concentration) were investigated and storage-related changes in erythrocyte response to oxidant stress explored. METHODS Erythrocytes were incubated with a lipophilic fluorescent probe and exposed to site-specific oxidant challenge, induced by cumene hydroperoxide, in the presence and absence of urate, ascorbate, or alpha tocopherol in physiological amounts. Fluorescence of labeled and treated erythrocytes was measured for 120 min using a Coulter EPICS Elite ESP flow cytometer. RESULTS Probe loading was dose and time dependent. Cumene hydroperoxide exhibited a potent and dose-dependent oxidant effect on erythrocyte membranes. Alpha tocopherol slowed, but did not prevent, membrane oxidation. Ascorbate appeared to have no effect on peroxidation initially, but then slowed and stopped propagation of membrane oxidation. The effect of urate was slight. CONCLUSIONS This technique can provide insight into oxidative processes at the cellular level. Results indicated that lipophilic alpha tocopherol was the most effective antioxidant in slowing membrane peroxidation, but ascorbate appears to stop chain propagation. This effect may be owing to vitamin C/E interaction. Further study is needed.
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Kim J, Yook JI, Park KK, Jung SY, Hong JC, Kim KJ, Kim JA, Chung WY. Anti-promotion effect of chlorophyllin in DMBA-TPA-induced mouse skin carcinogenesis. Anticancer Res 2000; 20:1493-8. [PMID: 10928061] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
Abstract
This study aimed to elucidate the inhibitory effects of chlorophyllin (CHL) at different promotion stages in a DMBA-TPA-induced mouse skin carcinogenesis model. TPA promotion was undertaken for 6, 18 and 24 weeks, respectively. Proliferating activity was observed immunohistochemically and the ornithine decarboxylase (ODC) mRNA level was analyzed by reverse transcriptase-polymerase chain reaction. Messenger RNAs for c-fos, c-jun and jun-B were also observed. CHL treatment clearly reduced proliferating activity and the level of ODC mRNA at the 18-week-promotion stage. When promoted for 24 weeks, CHL was not effective in reducing proliferating activity and ODC mRNA expression. These results indicate that the promotion stage of each target tissue should be considered in a chemopreventive program.
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Chung WY, Kim YJ. Expression of Ki-67 antigen using monoclonal antibody MIB-1 in children with post-streptococcal glomerulonephritis. Pediatr Nephrol 2000; 14:389-92. [PMID: 10805466 DOI: 10.1007/s004670050780] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
We investigated the expression of Ki-67 antigen using monoclonal antibody MIB-1 in glomeruli and renal tubules of 21 children (18 males, 3 females) with post-streptococcal glomerulonephritis (PSGN). Patients were divided into two groups of active and convalescent phases. The active group (n=13) comprised those patients with clinical manifestations of the acute nephritic syndrome consisting of edema, hypertension, hematuria, and oliguria or those in whom percutaneous renal biopsy was performed within 4 weeks of onset of the symptoms of PSGN and those with serum C3 levels below 55 mg/dl at the time of biopsy. MIB-1 expression was considered positive when staining of endocapillary cells was observed. Of the 21 biopsies, expression of MIB-1 in glomeruli and renal tubules was observed in 14 cases (63.6%) and 20 cases (95.7%), respectively. The expression of MIB-1 in glomeruli of patients with active disease (11/13, 84.6%) was significantly higher than that of the convalescent group (2/8, 25%) (P=0.018). The cellularity in the glomeruli was more severe in the active group than the convalescent group (P=0.0475). There was a significant difference of neutrophilic infiltration in glomeruli between the active group and the convalescent group (P=0.0117). However, glomerular MIB-1 expression did not correlate with the degree of immunofluorescence, the number of neutrophils in the glomeruli on light microscopy, and the presence of subepithelial dense deposits on electron microscopy. There was no significant correlation between MIB-1 and serum C3 level. There was no significant correlation between glomerular MIB-1 expression and creatinine clearance (r=-0. 180, P=0.556) or 24-h urinary protein excretion (r=0.434, P=0.137). Our results suggest that the expression of MIB- in glomeruli in the active phase in PSGN was higher than in the convalescent phase and expression of glomerular MIB-1 appears to be related to glomerular endocapillary proliferation with exudative lesions in children with PSGN.
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Kim NG, Roh JK, Kim JH, Chung WY, Park CS, Kim H. Clonality analysis using methylation-specific polymerase chain reaction: a novel method for investigating tumor clonality. J Transl Med 1999; 79:1727-9. [PMID: 10616221] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/15/2023] Open
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Chung WY, Lee JM, Park MY, Yook JI, Kim J, Chung AS, Surh YJ, Park KK. Inhibitory effects of chlorophyllin on 7,12-dimethylbenz[a]anthracene-induced bacterial mutagenesis and mouse skin carcinogenesis. Cancer Lett 1999; 145:57-64. [PMID: 10530770 DOI: 10.1016/s0304-3835(99)00229-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Chlorophyllin (CHL), a water-soluble derivative of chlorophyll, has been used for the treatment of several abnormal human conditions without apparent toxicity. Recent studies have revealed that CHL has the excellent chemopreventive potential. In the present investigation, we have found the inhibitory activities of CHL against 7,12-dimethylbenz[a]anthracene (DMBA)-induced mutagenesis in Salmonella typhimurium TA100 and also on DMBA-initiated and 12-O-tetradecanoyl-phorbol-13-acetate (TPA)-promoted mouse skin tumor formation. The incidence and the multiplicity of skin tumors were not significantly decreased in mice by a single topical application of CHL prior to the DMBA treatment, but there was a marked suppression of papillomagenesis in mice treated with CHL during the promotional stage. Furthermore, the formation of DMBA-induced papillomagenesis was reduced in all mice that had received CHL for 6 weeks following treatment with TPA for 6, 18 and 24 weeks. These results indicate that CHL can inhibit both tumor promotion and the progression of papillomagenesis in the two-stage mouse skin carcinogenesis induced by DMBA and TPA.
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Hsieh PC, Pan HC, Chung WY, Lee LS. Computerized tomography-guided stereotactic aspiration of brain abscesses: experience with 28 cases. ZHONGHUA YI XUE ZA ZHI = CHINESE MEDICAL JOURNAL; FREE CHINA ED 1999; 62:341-9. [PMID: 10389291] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/13/2023]
Abstract
BACKGROUND Computerized tomography (CT)-guided stereotactic techniques allow accurate identification of brain abscesses and provide promising results for the management of brain abscesses. METHODS We reviewed the results of stereotactic aspiration of brain abscesses in 28 consecutive patients from 1984 to 1995. In all patients, the diagnosis of brain abscess was made by computerized tomography (CT). All patients underwent stereotactic aspiration of abscesses as the primary surgical therapy. Intravenous antibiotics were administered preoperatively and adjusted according to organism type and sensitivity to antibiotics. In patients with multiple lesions, aspirations were performed on abscesses larger than 2 cm in diameter or on those causing significant mass effects. CT was performed weekly to monitor abscess growth or failure to resolve. Patients were followed on an outpatient basis. This report is a retrospective review of clinical features, diagnostic methods, treatment and postoperative results. RESULTS A total of 19 patients had good recoveries and six patients had mild neurologic sequelae. One patient had persistent conscious impairment. Intracranial hemorrhage occurred in one patient. Two deaths occurred during hospitalization. One patient with a fungal infection underwent additional surgical excision of the abscess. Most patients had resolution of abscesses after stereotactic treatment within two months. The cure rate was 92% in patients with bacterial brain abscesses treated with stereotactic aspiration and intravenous antibiotics for six weeks. CONCLUSIONS Stereotactic surgery is a procedure with minimal morbidity and mortality, and can be the treatment of choice for brain abscesses when combined with appropriate antibiotic therapy.
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Chung WY, Chung LP. A case of oral-facial-digital syndrome with overlapping manifestations of type V and type VI: a possible new OFD syndrome. Pediatr Radiol 1999; 29:268-71. [PMID: 10199905 DOI: 10.1007/s002470050586] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
We report a child with clinical and radiological manifestations characteristic of both V'aradi syndrome (oral-facial-digital syndrome type VI) and Thurston syndrome (oral-facial-digital syndrome type V). The findings have not been reported previously, and we believe that it represents a new variant.
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