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S N Chow

Publications and source records attributed to S N Chow.

At least 19 recordsLinked to original sources
PubMed2000

Humic acid suppresses the LPS-induced expression of cell-surface adhesion proteins through the inhibition of NF-kappaB activation.

Humic acid (HA), a potential toxin when penetrating the drinking well water of blackfoot disease-endemic areas in Taiwan, has been implicated as one of the etiological factors of this disease. In this study, we investigated the effects of HA on the expression of human vascular endothelial-leukocyte adhesion molecules and the activation of nuclear factor kappa B (NF-kappaB) in cultured human umbilical vein endothelial cells (HUVECs). The expression of intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), and E-selectin was monitored by flow cytometry. Pretreatment of HUVECs with HA inhibited the lipopolysaccharide (LPS)-induced expression of these three adhesion molecules in a dose- and time-dependent manner. Since NF-kappaB can regulate the expression of these adhesion molecules, NF-kappaB activation was assessed by electrophoretic mobility shift assay (EMSA). Our results reveal that the activation of NF-kappaB by LPS is suppressed by HA in a dose- and time-dependent manner. Furthermore, HA reduces NF-kappaB binding to DNA slightly, but completely inhibits the degradation of IkappaBalpha at a concentration of 100 microg/ml. Thus, all our data demonstrate that HA can inhibit the LPS-induced expression of adhesion molecules through the inhibition of NF-kappaB activation. HA may also suppress the immune or inflammatory reaction of HUVECs responsible for endotoxin, which could be one possible explanation for the causes of the infection and inflammation observed for patients with blackfoot disease. Our results also suggest that immune or inflammatory disturbance occurs for patients with blackfoot disease and that NF-kappaB may be a critical molecule in the pathogenesis of this disease.

Cell Adhesion↗
PubMed1999

Influence of histologic type and age on survival rates for invasive cervical carcinoma in Taiwan.

OBJECTIVE: The aim of this study was to assess survival rates and to evaluate histologic type and age as prognostic factors for cervical carcinoma in an ethnically homogenous population in Taiwan. METHODS: A retrospective analysis was conducted of 3678 cases of squamous cell carcinoma and adenocarcinoma that were diagnosed and treated for invasive cervical carcinoma between 1977 and 1994. Observed survival rates were estimated using the Kaplan-Meier method, and prognostic factors were assessed using Cox's proportional hazards regression analysis. RESULTS: Correlating both FIGO stage and age with histologic type revealed a higher proportion of cases with adenocarcinoma in the lower FIGO stages (P = 0.0417). Further, we found that the younger the age group the higher the proportion of cases of cervical adenocarcinoma (P = 0.0006). The 5-year survival rate was lower for patients with adenocarcinoma than for patients with squamous cell carcinoma (66.5 vs 74.0%, P = 0.0009). The 5-year survival rates for FIGO stages I, II, III, and IV squamous cell carcinoma were 81.3, 75.2, 42.7, and 26.1%, respectively, while for adenocarcinoma they were 75.9, 62.9, 29.2, and 0%, respectively. The difference in survival rates between squamous cell carcinoma and adenocarcinoma was found mainly in stage I (P = 0.0039) and stage II (P = 0.0103), where radiotherapy was used as the primary treatment. Age also affected the overall Kaplan-Meier estimate of survival. The younger the age group, the better the survival rate (P < 0.0001). Multivariate analysis confirmed a highly significant association between survival rate and both histologic type (P < 0.0001) and age (P = 0.0037). CONCLUSIONS: Early stage cervical cancer (stages I and II) with a glandular component had a lower 5-year survival rate than squamous cell carcinoma in cases where radiotherapy was the primary treatment. We speculate that this difference in survival rates between cervical adenocarcinoma and squamous cell carcinoma was due to the relative ineffectiveness of radiotherapy as a primary treatment in cases of adenocarcinoma.

Adenocarcinoma↗
PubMed1999

Diagnosis of oral cancer by light-induced autofluorescence spectroscopy using double excitation wavelengths.

A cancer diagnostic algorithm, light-induced autofluorescence spectroscopy using double excitations wavelengths, was employed for distinguishing between cancerous and normal oral mucosa. For emission spectra at the shorter excitation wavelengths (280, 290, and 300 nm), the ratio between the area under 325-335 nm and the area under 465-475 nm was calculated. In the same way, for emission spectra at the longer excitation wavelengths (320, 330, and 340 nm), the ratio between the area under 375-385 nm and the area under 465-475 nm was calculated. Receiver operating characteristic curves were used to evaluate the performance of algorithms using single and the double (by combining shorter and longer) excitation wavelengths. The results showed that better performance, up to sensitivity 81.25%, specificity 93.75%, and positive predictive value 92.86%, could be achieved by using the double excitation wavelengths. The present study can be useful as a basis for further investigation on in vivo autofluorescence measurement and analysis using double excitation wavelength.

Algorithms↗
PubMed1999

A probability-based multivariate statistical algorithm for autofluorescence spectroscopic identification of oral carcinogenesis.

A probability-based multivariate statistical algorithm combining partial least-squares (PLS) and logistic regression was developed to identify the development stages of oral cancer through analysis of autofluorescence spectra of oral tissues. Tissues were taken from a 7,12-dimethylbenz[a]anthracene-induced hamster buccal pouch carcinogenesis model. Analyses were conducted at various excitation wavelengths, ranging from 280 nm to 400 nm in 20 nm increments, to assess classification performance at different excitations. For each excitation the PLS analysis and logistic regression were combined, on the basis of cross validation, to calculate the posterior probabilities of samples belonging to four stages of cancer development: normal tissues, hyperplasia, dysplasia and early cancers and frankly invasive cancers. Results showed that the 320 nm excitation wavelength optimally classified the cancer development stages: the accuracy rates for identifying samples at that excitation were 91.7%, 83.3%, 66.7% and 83.3% for the four respective stages. The average accuracy rate was 81.3%. These results suggest that the algorithm described in this study might be useful for the detection of human oral cancers.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1998

Prognostic factors of primary adenocarcinoma of the uterine cervix.

OBJECTIVE: To determine which clinicopathological factors influence the prognosis of cervical adenocarcinoma. METHODS: Three hundred and two cases of primary adenocarcinoma of the uterine cervix, treated between 1977 and 1994, were studied retrospectively. Clinical data and pathological findings with respect to primary therapy were reviewed and evaluated. RESULTS: The 5-year survival rates for stages I, II, and III/IV were 75.9, 62.9, and 25.1%, respectively. International Federation of Gynecology and Obstetrics stage (P < 0. 0001), cell type (P = 0.0176), tumor grade (P = 0.023), lymph node status (P = 0.018), and bulky tumor (P = 0.007) were found to be independent factors using the stepwise Cox proportional hazards model. Old age (P = 0.0581), presence of hypertension (P = 0.46), diabetes mellitus (P = 0.18), obesity (P = 0.15), and oral contraceptive use (P = 0.42) were not found to adversely influence survival rates for cervical adenocarcinoma after adjusting for other covariates. Adenosquamous adenocarcinoma had a better prognosis than endocervical columnar cell adenocarcinoma in stages I and II (P = 0. 0235). Also, in cervical adenocarcinoma's early stages, multivariate modeling revealed that chances of survival were significantly better for patients treated by radical surgery than for patients treated by radiation therapy (P < 0.001). CONCLUSIONS: Survival rates for cervical adenocarcinoma were significantly influenced by stage, histologic subtype, tumor grade, the presence of a positive lymph node, and tumor size. Although a randomized prospective study is needed, our data imply that radical surgery may be considered a better primary modality of treatment than radiation therapy for the early stages of cervical adenocarcinoma. Further, the presence of hypertension, diabetes mellitus, or obesity may not adversely influence survival rates.

Adenocarcinoma↗
PubMed1998

Ratiometric confocal Ca2+ measurements with visible wavelength indicators in d-amphetamine-treated central snail neuron.

1. The bursting firing of action potentials and cytosolic calcium content in d-amphetamine-treated RP4 neurons of the African snail, Achatina fulica Ferussac, were studied elelctrophysiologically and optopharmacologically. 2. d-Amphetamine elicited bursting of firing of action potentials in central RP4 neuron. The bursting firing of action potentials was blocked following extracellular application of ruthenium red, the calcium uptake and release inhibitor from mitochondria. 3. At the same neuron, image analysis using ratiometric measurement on calcium green 1 and Texas red dextran (70,000 MW) with laser-scanning confocal microscopy revealed that cytosolic calcium content was increased after d-amphetamine treatment. 4. Our results support the view that the bursting firing of action potentials elicited by d-amphetamine is associated with cytosolic calcium content.

Action Potentials↗
PubMed1998

Autofluorescence in normal and malignant human oral tissues and in DMBA-induced hamster buccal pouch carcinogenesis.

Light-induced fluorescence spectroscopy was conducted on human oral malignant and normal tissues. Under 330-nm excitation wavelength, significant differences in fluorescence intensity were observed around 380- and 460-nm emission. Furthermore, 7,12-dimethylbenz[a]anthracene (DMBA)-induced carcinogenesis in hamster buccal pouch was investigated to elucidate whether similar alterations of fluorescence spectroscopy occurred during the development of squamous cell carcinoma. Similar to the spectral profiles of human oral malignant and normal tissues, the most intense fluorescence peaks in the pouches occurred at 380 nm and 460 nm emission under 330 nm excitation wavelength. At 380 nm emission, the fluorescence intensity of normal pouch mucosa was stronger than those of DMBA-treated abnormal tissues at different stages of carcinogenesis. However, at 460 nm emission, the fluorescence intensity of DMBA-treated tissues was not only stronger than that of normal pouch mucosa but also shifted to 470 nm. These results suggest that under 330 nm excitation wavelength fluorescence spectroscopy may be useful for the detection of oral malignant lesions.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1997

Identification of LDH-ras p21 protein complex and expression of these genes in human ovarian cancer.

Normal ovarian and ovarian cancer tissues from 35 patients were tested for LDH-A-ras protein complex formation, as well as for the expression of ras and LDH-A genes. By immunodetection of the immunoprecipitates, LDH-A-ras protein complexes are present in the homogenates of human ovarian tissues (benign and malignant). Two bands of 21 and 36 kDa were demonstrated in affinity-purified LDH active fractions by Western blot analysis, and these two proteins were proved to be ras p21 and LDH-A by immunodetection. By Northern blot analysis, elevated levels of c-Ki-ras and LDH-A mRNA transcripts were noted in 49% (17/35) and 40% (14/35) of ovarian cancers, respectively. Concurrent high expression of both genes was demonstrated in 11 cases (31%). Tyrosylphosphorylation of LDH-A was demonstrated in normal and malignant ovarian tissues, and the extent of phosphorylation was correlated with the stage of ovarian cancer. The concurrent elevated expression of ras and LDH-A in the same ovarian tissue may imply that the increased synthesis of LDH-A is due to increased or amplified signaling of the ras-cascade pathway. The possible biochemical role of the tyrosylphosphorylated LDH-A complexed with ras p21 in cell transformation and progression of human ovarian cancer is worthy of further investigation.

Female↗
PubMed1997

Detection of serum transforming growth factor-alpha in patients of primary epithelial ovarian cancers by enzyme immunoassay.

Transforming growth factor-alpha (TGF-alpha) is a potent mitogenic polypeptide. It is secreted by a variety of transformed cells and tumors, modifying tumor growth through autocrine or paracrine mechanism. In the present study, serum levels of TGF-alpha were determined by enzyme-linked immunosorbent assay (ELISA) in 27 normal females, 116 patients with benign ovarian tumors, and 42 patients with epithelial ovarian cancers (10 with stage I, 7 with stage II, 19 with stage III, and 6 with stage IV). The ELISA assay could detect a minimum level of serum TGF-alpha concentration at 10 pg/ml. Serum samples were obtained from normal females and from patients with benign or malignant ovarian tumors before initial surgery. The detectable rates were 11% (3/27) in normal females, 28% (32/116) in benign ovarian tumors, and 62% (26/42) in ovarian cancers. The detectable rates in serous and endometrioid ovarian cancers were 71 and 70%, respectively, which were higher than the rate of 33% in mucinous type. However, there was no obvious relationship between the detectability of serum TGF-alpha and the stages of ovarian cancers. The mean concentration of TGF-alpha in ovarian cancer was 159.8 pg/ml, which was significantly higher than 27.7 pg/ml in benign ovarian tumors (P < 0.001) as well as 15 pg/ml in normal females (P < 0.001). The mean concentrations of serum TGF-alpha in stages I to IV ovarian cancers were 133.5, 96.2, 194.8, and 178.3 pg/ml, respectively. The mean concentration of serum TGF-alpha in any two stages of ovarian cancers was not statistically different. In conclusion, measurement of serum TGF-alpha can be used as a supplementary tumor marker to differentiate a malignant ovarian tumor from a benign one. However, the concentration of serum TGF-alpha has no special relation with the stage of ovarian cancer itself. Because of the small number of stage I ovarian cancers with detectable TGF-alpha in the present investigation, it would probably not be feasible to differentiate a stage I ovarian cancer from a benign ovarian tumor based only on the level of TGF-alpha in serum.

Biomarkers, Tumor↗
PubMed1997

Light-induced fluorescence spectroscopy to differentiate benign and malignant uterine cervical lesions.

In Taiwan, cervical cancer is the leading malignancy among women. For the early detection of cervical neoplasia, light-induced fluorescence spectroscopy was conducted ex vivo to assess the ability of this technique to differentiate cervical neoplastic tissue (20 samples) from normal or inflammatory cervical tissue (37 samples) at an excitation wavelength of 280 nm. The principal fluorescent peaks occurred within +/- 5 nm of 330 nm and 470 nm emission. At 330 nm emission, the spectrum of the normal or inflammatory tissue was significantly stronger than that of the neoplastic tissue after are normalization. However, at 470 nm emission, the spectrum of the normal or inflammatory tissue was significantly weaker than that of the neoplastic tissue. A diagnostic algorithm based on the ratio of relative intensities of 330 nm to 470 nm emission within the 5 +/- nm peak area of each sample was calculated and paired. The ratios showed that histologically neoplastic lesions could be distinguished from inflammatory samples using a 280-nm-excitation wavelength with a sensitivity, specificity and positive predictive value of 94%, 82% and 73%, respectively. The average ratio of malignant or dysplastic cervical samples was significantly greater than that of the inflammatory samples (p < 0.001). Our ex vivo study indicated that light-induced fluorescence spectroscopy may be useful in differentiating malignant or premalignant from normal or inflammatory cervical tissue.

Algorithms↗
PubMed1997

Demographic characteristics and medical aspects of menopausal women in Taiwan.

This report describes the medical and demographic characteristics of menopausal women in Taiwan in order to provide information for consideration during future healthcare planning. The medical and demographic data analyzed were taken from officially published materials of the Government of the Republic of China on Taiwan, our own studies, and those of other researchers. In 1994, the average lifespan of men in Taiwan was 71.8 years and that of women was 77.7 years. The age of menarche was 13.6 years and the age of menopause was 49.5 years. Women aged 50 and over accounted for 18.3% of the total female population and 8.9% of the total population in Taiwan. In 1994, 68.9% of women in Taiwan aged 50 and over were married. The most frequently occurring menopausal symptoms in Taiwanese women were lumbago or low backpain (68%), fatigue (59%), impairment of memory (55%), vaginal dryness (50%), and hot flushes and sweating (49%). The spinal bone mineral density of women decreased markedly after the age of 50 years. The prevalence of vertebral fracture in women 65 years and over was 19.8%, which was higher than the 12.5% in men of the same age group. The prevalence of hypertension and coronary heart disease in women 50 years or older was also higher than in men. The most frequent sites of cancer in women in 1992 were the cervix uteri, breast, sigmoid colon and rectum, lungs, liver, stomach, thyroid, ovaries, hemopoietic and reticuloendothelial systems, and skin. There were 14,298 newly reported cases of malignant neoplasms in women in 1992. About 60% of these occurred in women aged 50 years or more. The median age of occurrence of cervix uteri, breast, and ovarian cancers was 48 to 49 years, which is very close to the menopause age. About 30% of menopausal women in Taiwan are currently living without a husband. Although 18.3% of women in Taiwan were at least 50 years old, approximately 60% of all malignant neoplasms in the female population occurred in this group. There is an urgent need for menopausal women in Taiwan to receive psychologic support and comprehensive medical care.

Adult↗
PubMed1996

Malignant ovarian germ cell tumors.

OBJECTIVES: Fifty patients with malignant ovarian germ cell tumors, which accounts for 10.8% of all ovarian malignancies, were treated from 1977 through 1994. Their cases are reviewed. METHODS: The histology includes endodermal sinus tumor (EST) in 15 patients, immature teratoma in 14, dysgerminoma in 13, and mixed germ cell tumor in eight. The mean age at presentation was 21.5 years and mean primary tumor diameter was 16 cm. All patients underwent surgery as the initial treatment, and 10 received more than one operation. Postoperative adjuvant chemotherapy was not given to cases with stage Ia immature teratoma and dysgerminoma. VAC (vincristine, actinomycin D, cyclophosphamide) and BVP (bleomycin, vinblastine, cisplatin) regimens were utilized in early 1980s for EST and advanced-stage tumors of immature teratoma and dysgerminoma. BEP (bleomycin, etoposide, cisplatin) and EP (etoposide, cisplatin) regimens were applied in advanced-stage disease and some stage I disease since 1990. VIP (VP-16, ifosfamide, cisplatin) regimen was employed as salvage regimen in cases where other combinations failed. RESULTS: alpha-Fetoprotein (AFP) was elevated in every tumor containing endodermal sinus element, and AFP served as a good indicator for prediction of tumor recurrence. The follow-up time ranged from 5 to 144 months with the mean of 54.5 months. CONCLUSIONS: The survival rate for EST was 54%, that for immature teratoma and dysgerminoma was 85% and 90%, respectively.

Adolescent↗
PubMed1996

Borderline malignant tumors of the ovary: study of prognostic factors.

A 16-year review of borderline tumors of the ovary was carried out to study the clinical features and outcomes of patients and to assess the value of color Doppler ultrasound in preoperative diagnosis. The records of 53 patients with borderline tumors of the ovary were retrospectively analyzed for clinical features, sonographic findings and survival. Twenty-three of 44 patients with stage I disease were treated conservatively without recurrence. Seven of eight (87.5%) patients with stage III disease developed recurrent or persistent tumors within 3 years. Overall, eight of 53 (15.1%) patients had recurrent or persistent disease. Twenty-three of 44 (52.3%) patients with borderline ovarian tumors showed morphologic malignancy by gray-scale sonography. Ten of 13 (76.9%) patients who had color Doppler ultrasound examination had detectable intratumoral blood flow. The mean resistance index value was 0.47 (range, 0.3-0.6). Three of these patients (30%) had a resistance index value < 0.4. The results indicated that the extent of disease as reflected by the clinical stage was the main factor for prediction of recurrence, and borderline tumors of the ovary were not efficiently differentiated from benign or malignant tumors by resistance index values obtained from color Doppler ultrasound.

Adolescent↗
PubMed1996

The suitable treatment for adenocarcinoma in situ of uterine cervix: a report of four cases.

Adenocarcinoma in situ (AIS) of the uterine cervix is a rare disease. Some authors suggested that conization is a suitable treatment for AIS as for squamous cell carcinoma in situ. However, others did not agree. Four cases of AIS, from 1984 to 1994, have been diagnosed in the Hospital of National Taiwan University. If the diagnosis of the conization specimen showed AIS, abdominal total hysterectomy was performed days thereafter. The remaining uterine cervix was checked by histopathology to determine whether it was free of cancer lesions. AIS lesions remained in the uterine cervix, as shown by conization in two cases. AIS is not like lesion as squamous cell carcinoma in situ lesion which is easy to be removed by conization. It is suggested that conization is not an adequate treatment for AIS, rather, a total hysterectomy should be performed.

Adenocarcinoma↗
PubMed1996

Light-induced fluorescence spectroscopy: a potential diagnostic tool for oral neoplasia.

For the early detection of oral neoplasia, light-induced fluorescence spectroscopy was used to measure the fluorescence emission of malignant (squamous cell carcinoma & verrucous carcinoma) and premalignant (epithelial dysplasia, hyperkeratosis & lichen planus) oral tissues as well as normal oral mucosa ex vivo to assess the ability of this technique to distinguish neoplastic from normal oral tissues. The emission spectra of histologically normal and neoplastic oral tissues were obtained under excitation wavelengths varied from 270 nm to 400 nm at 10-nm intervals. At 300-nm excitation, the most intensely fluorescent peak occurred at 330-nm and 470 nm emission. At 330-nm emission, the spectrum of the malignant oral tissue was significantly stronger than that of the normal oral mucosal tissue after area normalization. However, at 470-nm emission, the spectrum of the malignant oral tissue was significantly weaker than that of the normal oral mucosal tissue. A diagnostic algorithm based on the ratio of relative intensities of 330 nm to 470 nm emission within the +/-5 nm peak area of each sample was calculated and paired. The histogram of ratios showed that histologically neoplastic oral tissues could be distinguished from normal oral mucosal tissues using the 300 nm excitation wavelength. The average ratio of malignant or premalignant oral samples was significantly greater than that of the normal oral mucosal samples (p < 0.001). This ex vivo study indicated that fluorescence spectroscopy may be useful in differentiating malignant or premalignant oral tissue from normal oral mucosa.

Areca↗
PubMed1995

Independent clinical factors which correlate with failures in diagnosing early cervical cancer.

Our aim was to identify independent factors that correlated with colposcopically directed biopsy's reliability as a method for diagnosing early cervical cancer. One hundred ninety-one of a total of 2265 patients who had colposcopic examinations because of abnormal Papanicolaou smears were included in this study. These patients had all undergone a hysterectomy after being diagnosed as having cervical intraepithelial neoplasia grade III by colposcopically directed biopsy. By univariate analysis, old age (P = 0.0195), achievement of menopausal status (P = 0.0046), large lesion size (P = 0.0021), and unsatisfactory colposcopy (P = 0.0017) were found to be associated with the nondiagnosis of early cervical cancer. However, multivariate analysis using stepwise logistic regression revealed that large lesion size (P = 0.003) and unsatisfactory colposcopy (P = 0.0008) were the only independent factors that correlated with nondiagnosis. Our findings indicate that in order to reach a clear-cut diagnosis, cases with either unsatisfactory colposcopy or satisfactory colposcopy with large lesions (despite a lack of histologic evidence of invasions) should undergo a diagnostic conization.

Adult↗