Topiramate induced myopic shift and angle closure glaucoma.
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Adult↗
Biomedical subjects
T C Chen
Publications and source records attributed to T C Chen.
Adsorption characteristics of benzene on biosolid adsorbent.
This study selected biosolids from a petrochemical wastewater treatment plant as the raw material. The sludge was immersed in 0 to 5 mol l(-1) of ZnCl2 solutions and pyrolyzed at different temperatures. When the sludge was pyrolyzed for 30 min at temperatures of 400, 500, 600, and 700 degrees C, the corresponding surface area of the biosolid adsorbent was 46, 401, 921, and 727 m2/g, respectively. Pore size analysis indicated that the mesopore (20 to 500 A) contributed more than the macropore and micropore in the sludge pyrolytic residue. When the benzene influent concentration was 800 ppmv, the adsorption capacity ranged from 59 to 164 mg/g for different biosolid adsorbents. A larger BET surface area and smaller average pore diameter yielded a larger benzene adsorption capacity.
Adsorption↗
Successful treatment with weekly paclitaxel in a patient with recurrent endometrial cancer. A case report.
The best treatment for recurrent endometrial cancer is still uncertain, although weekly paclitaxel has shown some promise in the management of this disease. In this report we present a patient with recurrent endometrial cancer treated with weekly paclitaxel. Serial power Doppler angiography was used to assess the effects of therapy. The response was good, suggesting that recurrent endometrial cancer may be successfully treated with weekly paclitaxel and effectively monitored with power Doppler angiography.
Adenocarcinoma↗
Nuclear beta-catenin expression is closely related to ulcerative growth of colorectal carcinoma.
Although most colorectal cancer develops based on the adenoma-adenocarcinoma sequence, morphologically, colorectal cancer is not a homogeneous disease entity. Generally, there are two distinct morphological types: polypoid and ulcerative colorectal tumours. Previous studies have demonstrated that K-ras codon 12 mutations are preferentially associated with polypoid growth of colorectal cancer; however, little is known about the molecular mechanism that determines ulcerative growth of colorectal cancer. beta-catenin complex plays a critical role both in tumorigenesis and morphogenesis. We examined the differential expression of beta-catenin and its related factors among different types of colorectal cancer in order to determine any relationship with gross tumour morphology. Immunohistochemical staining of beta-catenin, E-cadherin and MMP-7 was performed on 51 tumours, including 26 polypoid tumours and 25 ulcerative tumours. Protein truncation tests and single-strand conformational polymorphism for mutation of the adenomatous polyposis coli tumour suppressor gene, as well as single-strand conformational polymorphism for the mutation of beta-catenin exon 3 were also done. Nuclear expression of beta-catenin was observed in 18 out of 25 (72%) cases of ulcerative colorectal cancer and seven out of 26 (26.9%) cases of polypoid colorectal cancer. A significant relationship of nuclear beta-catenin expression with ulcerative colorectal cancer was found (P<0.001). However, this finding was independent of adenomatous polyposis coli tumour suppressor gene mutation and E-cadherin expression. Together with previous data, we propose that different combinations of genetic alterations may underlie different morphological types of colorectal cancer. These findings should be taken into consideration whenever developing a new genetic diagnosis or therapy for colorectal cancer.
Adenomatous Polyposis Coli↗
Hyperbaric oxygen increases the lung's susceptibility to inhaled lipopolysaccharide in mice.
Hyperbaric oxygen (HBO2) has been shown to inhibit the adhesion function of beta(2)-integrin, which is important in mediating cell-to-cell adhesion and extravasation of inflammatory cells. In the present study, we examined the effects of HBO2 exposure on neutrophil infiltration and tissue injury in a model of acute lung inflammation induced by lipopolysaccharide (LPS) inhalation. Male C57BL/6 mice of 8 weeks old were exposed to 3 atmosphere absolute (ATA) 100% HBO2, 3 ATA hyperbaric air (HBA), or room air for 90 min. After exposure, they were exposed to aerosolized LPS solution (1 mg/ml) or saline in a plexiglass chamber for 10 min. Four hours after inhalation, bronchoalveolar lavage (BAL) was performed to determine protein concentration, LDH activity, total cells, and differential cell counts in the lavage fluid (BALF). Myeloperoxidase (MPO) content, lung histopathology, and plasma nitric oxide (NO) metabolite concentrations were also determined in separate sets of animals. We observed that LPS inhalation increased neutrophil number in the BALF, which was significantly inhibited by HBO2 but not HBA pre-exposure. However, MPO content in the lung was prominently increased by HBO2 pre-exposure, which correlated with increased PMN infiltration in lung tissues. Further, HBO2 plus LPS, but not saline inhalation caused a significant increase in the BALF protein level and LDH activity compared with that of LPS inhalation alone. LPS exposure induced significant increase in plasma NO metabolites, which was not potentiated by HBO2 pre-exposure. The inducible nitric oxide synthase inhibitor, aminoguanidine, significantly attenuated the increases in plasma NO metabolites and tissue MPO content as well as lung injuries. In summary, our data suggest that HBO2 pre-exposure increases the lung's susceptibility to inhaled LPS, which may be related to increased tissue neutrophil infiltration and dependent on interaction(s) between HBO2 exposure with LPS-induced nitric oxide production.
Administration, Inhalation↗
Role of impurities in the thermoluminescence of LiF:Mg,Cu,P.
The thermoluminescent properties of lithium fluoride doped with magnesium, copper and phosphorous are reviewed. This material shows specific advantages over LiF (TLD-100) in that is has higher sensitivity, less energy dependence and no supralinear behaviour with dose. However, it suffers from an irreversible loss in sensitivity when heated above 270 degrees C. Possible causes for this loss in sensitivity are discussed and experimental results are shown that indicate potential roles for the Cu, P and O impurities in this process. The present work focuses on the understanding of the impurity contents, inclusions, cluster formation and valence changes in this material by using differential scanning calorimetry (DSC) and glow discharge mass spectroscopy (GDMS). This research concludes that phosphorus inclusions are formed and a valence change of the Cu ions occurs after annealing above 270 degrees C, which degrades the TL sensitivity of LiF:Mg,Cu,P phosphors. It is also shown that a high content of oxygen in the material and control of the oxygen content during processing are critical to maintaining the sensitivity of these phosphors.
Calorimetry, Differential Scanning↗
Biliary papillary neoplasm of the liver.
Biliary papillary neoplasia of the liver characterized by intraductal papillary growth of neoplastic biliary epithelia with a fine fibrovascular stalk has been sporadically reported, and includes intraductal growing cholangiocarcinoma and biliary papillomatosis. In addition, biliary papillary dysplasia and in situ and microinvasive carcinoma with papillary configuration reported in hepatolithiasis and in other chronic biliary diseases, could be included in this category. Usually, they arise in the intrahepatic large bile ducts, and the neoplastic and non-neoplastic parts of the intrahepatic biliary tree show saccular and segmental dilatation with mucin hypersecretion. This neoplasia frequently shows intraductal spreading and peribiliary glandular involvement. Acute repeated episodes of cholangitis or obstructive jaundice are a frequent clinical manifestation. Gastroenteric metaplasia with aberrant expression of cytokeratin 20, MUC2, MUC5AC, and/or MUC6, is frequent in the neoplastic parts, and biliary epithelial dysplasia with such metaplasia may give rise to in situ and then invasive carcinoma in hepatolithiasis. Interestingly, this type tends to contain foci of mucinous carcinoma elements, and this element may be predominant (mucinous carcinoma). Some may progress to "mucinous biliary cystadenocarcinoma" without ovarian mesenchymal stroma and with intraluminal continuous growth into the neighboring bile duct lumens. Interestingly, the biliary papillary neoplasm resembles histologically, phenotypically and clinically intraductal papillary mucinous neoplasm of the pancreas which is now being established as an infrequent, slow-growing pancreatic neoplasm. Recognition of such biliary papillary neoplasm with respect to the pancreatic equivalent may lead to a better understanding and further studies of the intrahepatic biliary neoplasm.
Aged↗
Effects of UV irradiation on selected pathogens in peptone water and on stainless steel and chicken meat.
Effects of intensity and processing time of 254 nm UV irradiation on Listeria monocytogenes, Escherichia coli O157:H7, and Salmonella Typhimurium were investigated. Intensities measured at 5.08, 10.1, 15.2, and 20.3 cm from the light source were 1.000, 500, 250, and 150 microW/cm2, respectively. Intensities of 250 or 500 microW/cm2 reduced all suspended pathogen cells in peptone water about 5 log cycles after 2 min and completely inactivated L. monocytogenes and E. coli O157:H7 after 3 min by reductions of 8.39 and 8.64 log cycles, respectively. Intensities of 250 or 500 microW/cm2 also reduced (P < or = 0.05) the tested pathogens inoculated on stainless steel (SS) chips, and E. coli O157:H7 was completely destroyed at 500 microW/cm2 for 3 min. After UV treatment for 3 min at 500 microW/cm2, all selected pathogens on chicken meat with or without skin showed reduction ranges from 0.36 to 1.28 log cycles. Results demonstrated that UV irradiation could effectively decrease pathogens in peptone water and on SS but that it was less effective on chicken meat.
Animals↗
Stabilization of an elevated heavy metal contaminated site.
Heavy metal contamination is a common problem that is encountered at many uncontrolled sites. Immobilization is seen as a promising technology for heavy metal remediation. Here, we report a remediation case study of an elevated and multi-metal contaminated site containing Cd, Cu, Ni, Pb, and Zn. In a laboratory test, when the soil was stabilized with reagent grade stabilizers (CaHPO(4) and CaCO(3)), the toxicity characteristic leaching procedure (TCLP) extractable concentrations of Cd, Cu, Pb, and Zn were reduced by more than 87%. The greatest reduction was shown with Pb (99.8%). In the field, Ca(H(2)PO(4))(2) due to lower cost and higher solubility replaced CaHPO(4). The TCLP results of the field treatment showed that the extractable concentrations of Cd, Cu, Pb, and Zn were significantly reduced after 30 days of stabilization. The reduction ratios were 98% (Cd), 97% (Cu), 99% (Pb), and 96% (Zn). Although, the reduction ratio of Ni was only 65%, the average extractable concentration was still less than 4.0mg/l. The percent reduction can, therefore, be considered reasonable. The significant reduction of extractable metal concentrations showed that the stabilizers, a combination of Ca(H(2)PO(4))(2) and CaCO(3), successfully immobilized heavy metals on the site.
Carbonates↗
On-line monitoring of trihalomethanes in drinking water using continuous-flow purge and cryofocusing gas chromatography-mass spectrometry.
A continuous-flow purge-and-trap-GC-MS system was developed for on-line monitoring of THMs (trihalomethanes) in drinking water. Three systems with different traps and purging flow-rates are discussed. In order to minimize interference from water vapor, total purge gas volume and injection temperature were controlled during analysis. Shorter sample concentration time and GC separation time reduced total cycle time to less than 5 min. The detection limits of the system could be lowered to 10 ppt, 25 ppt, 40 ppt, and 50 ppt (w/w) for CHCl3, CHCl2Br, CHClBr2, and CHBr3, respectively. This system could detect changes in sample concentration when applied to the on-line monitoring of THMs in drinking water.
Gas Chromatography-Mass Spectrometry↗
Vitamin D intoxication associated with an over-the-counter supplement.
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Adult↗
Drop metastasis from sinonasal undifferentiated carcinoma: clinical implications.
STUDY DESIGN: The first reported case of multiple intradural, extramedullary spinal metastasis from sinonasal undifferentiated carcinoma is presented. OBJECTIVES: To elucidate the mechanisms by which metastatic disease invades the spinal axis, and to discuss the possibility of spinal drop metastasis from head and neck tumors that invade the dura. SUMMARY OF BACKGROUND DATA: Sinonasal undifferentiated carcinoma is a rare yet aggressive neoplasm of the upper airways and anterior skull base. This neoplasm is known to invade the cranial vault and brain locally. However, it has not previously been reported to seed the cerebrospinal fluid or result in drop metastasis. Such drop metastasis may result in significant neurologic deficit if not diagnosed and treated in a timely manner. METHODS: This report is based on a single patient treated by a multidisciplinary team from the departments of neurosurgery, otolaryngology, and radiation oncology at the University of Southern California School of Medicine. RESULTS: This patient initially underwent resection and local radiation therapy for sinonasal undifferentiated carcinoma of the anterior skull base. At the time of surgery, the tumor was noted to violate the dura and arachnoid along the subfrontal plane. At 11/2 years after the initial treatment, a bandlike distribution developed at T2 as well as paresthesias and numbness below that level. Imaging of the spine showed an intradural, extramedullary tumor at T2 consistent with a schwannoma or meningioma. The patient underwent a laminectomy and tumor resection, which showed poorly differentiated sinonasal carcinoma. Local radiation therapy was administered, and the patient experienced complete recovery of neurologic function. Bilateral leg pain and weakness developed 14 months later. Magnetic resonance imaging of the spine showed a new intradural, extramedullary lesion at T12, remote from the first lesion. This second metastasis was managed with surgical resection and adjuvant radiation therapy. CONCLUSIONS: This is the first reported case of a sinonasal carcinoma leading to intradural extramedullary metastasis. The primary tumor likely seeded the cerebrospinal fluid, thus resulting in drop metastasis. Patients with sinonasal undifferentiated carcinoma that invades the dura should be monitored closely for evidence of metastasis before symptoms develop.
Carcinoma↗
25-hydroxyvitamin D-1alpha-hydroxylase in normal and malignant colon tissue.
Vitamin D affects calcium metabolism and prevents proliferation of colon cells in vitro. In human beings the main circulating form of vitamin D is 25-hydroxyvitamin D; to regulate calcium homoeostasis, this form must be converted to 1alpha, 25-dihydroxyvitamin D by 1alpha-hydroxylation in the kidney with 25-hydroxyvitamin D-1alpha-hydroxylase. Cultured transformed colon cancer cells can convert 25-hydroxyvitamin D(3) to 1alpha,25-dihydroxyvitamin D(3). We identified messenger RNA (mRNA) for 25-hydroxyvitamin D-1alpha-hydroxylase in normal colon tissue and in malignant and adjacent normal colon tissue. These findings support the notion that vitamin D might have a role in cell growth regulation and cancer protection, and might be the explanation for why the risk of dying from colorectal cancer is highest in areas with the least amount of sunlight.
25-Hydroxyvitamin D3 1-alpha-Hydroxylase↗
Genome-wide hypomethylation in hepatocellular carcinogenesis.
Aberrant genome-wide hypomethylation has been thought to be related to tumorigenesis. However, its mechanism and implications in hepatocellular carcinogenesis remain to be elucidated. Samples of hepatoma (hepatocellular carcinoma, HCC) and paired non-HCC liver tissues were obtained from 17 HCC patients. Normal liver tissues obtained from three individuals were used as controls. Compared with the paired non-HCC liver tissues, genome-wide 5-methylcytosine content in HCC was reduced in all of the tested HCC samples (P < 0.001). Conversely, genome-wide 5-methylcytosine content did not significantly differ among normal, noncirrhotic, and cirrhotic liver tissues. Moreover, the degree of reduced DNA methylation was related to late histopathological HCC grade (P = 0.005) and large tumor size (P = 0.079). Compared with the paired non-HCC liver tissues, expression of DNA methyltransferases DNMT-1, DNMT-3A, and DNMT-3B and the DNA methyltransferase-like gene, DNMT-2, was up-regulated in 53, 41, 59, and 47% of the HCC samples, respectively. Surprisingly, small amounts of LINE-1 retrotransposon transcripts were detected in HCC and non-HCC as well as normal liver tissues, and the expression levels were not significantly different in HCC compared with the paired non-HCC or normal liver tissues. Of interest, the 3' ends of these LINE-1 transcripts were truncated. Our findings suggest that genome-wide hypomethylation in HCC is a continuing process that persists throughout the lifetime of the tumor cells rather than a historical event occurring in precancer stages or in cell origins for HCC. Up-regulation of DNA methyltransferases might simply be a result of increased cell proliferation in cancer. In addition, our results did not support the hypothesis of activation of transposable elements in HCC via genome-wide hypomethylation.
5-Methylcytosine↗
Angiomyolipoma of the liver.
BACKGROUND AND OBJECTIVES: Angiomyolipoma is a rare benign tumor that occurs in the liver and other organs. We provide data on eight cases of hepatic angiomyolipoma, regarding clinical presentations, diagnoses, management, and prognosis. METHODS: A retrospective review of medical records of the eight patients with hepatic angiomyolipoma treated at the Chang Gung Memorial Hospital-Taipei between October 1988 and October 1999. RESULTS: Eight female patients with hepatic angiomyolipoma were identified, with ages ranging from 30 to 66 years (mean, 45.3 years). Abdominal pain was the most common symptom, occurring in six of eight patients (75%). Hepatocellular carcinoma was the most common preoperative diagnosis, occurring in three of eight patients (37.5%). Laparotomy was performed in seven of eight patients (87.5%). Among these seven patients, three patients (43%) received hepatic resection with 100% cure rate to date. One of the eight patients (12.5%) was closely follow up after diagnosis made by echo-guided needle biopsy. CONCLUSIONS: Hepatic angiomyolipoma is a rare and benign entity. It has a wide variation and poses a diagnostic challenge clinically, radiologically, and pathologically. Its prognosis is good regardless of management, including hepatic resection or conservative treatment after tissue biopsy by echo-guided needle. To alleviate the mass effect, surgical resection may be needed for hepatic angiomyolipoma in selected cases.
Abdominal Pain↗
Observations on serum 25-hydroxyvitamin D and calcium concentrations from wild-caught and captive neotropical bats, Artibeus jamaicensis.
Most bats of the suborder Microchiroptera are nocturnal, actively avoid sunlight, and eat mineral-poor diets. In those bats previously studied with respect to mineral metabolism, extensive bone remodeling occurs, and it has been suggested that calcium has been an important constraint on reproduction. There have been no previous studies of vitamin D or its metabolites in microchiropteran bats with respect to calcium metabolism. Reported is the utilization of current advances for the determination of serum levels of the vitamin D metabolite 25-hyroxyvitamin D (25-OH-D) in a neotropical bat, Artibeus jamaicensis. Serum from wild-caught animals contained low levels of 25-OH-D (5.6 +/- 3.0 ng/ml, n = 8). Bats maintained on a vitamin-D-supplemented diet had higher serum 25-OH-D levels and when the diet containing vitamin D was discontinued, mean serum 25-OH-D levels declined significantly after 6 months. Serum calcium concentrations in wild-caught bats (8.5 +/- 0.4 mg%) showed very little variation and were not significantly different in any of the vitamin-D-supplemented animals. A pairwise correlation analysis between 25-OH-D and serum calcium levels revealed no linear correlation. The results indicate either that 25-OH-D does not appear to play a key role or that low levels of 25-OH-D may be adequate in regulating serum calcium levels in this bat.
25-Hydroxyvitamin D 2↗
Hepatocellular carcinoma associated with focal nodular hyperplasia. Report of a case with clonal analysis.
We describe a hepatocellular carcinoma partially surrounded by focal nodular hyperplasia in a 65-year-old female patient. In order to clarify the relationship of the hepatocellular carcinoma and the adjacent focal nodular hyperplasia, clonal analysis was conducted. The clonal analysis was based on the methylation pattern of the polymorphic X-chromosome-linked androgen receptor gene (HUMARA). The allelic bands from the amplification of the focal nodular hyperplasia and of the hepatocellular carcinoma showed a significant reduction in the intensity of one of the two alleles as compared with two alleles of equal intensity in the buff coat after HhaI digestion, which indicated that these two parts were monoclonal. However, the inactivated allele in the focal nodular hyperplasia and that in the hepatocellular carcinoma were not identical. Therefore, the focal nodular hyperplasia and hepatocellular carcinoma probably derived from the clonal expansion of two different clones.
Aged↗
Brimonidine 0.2% versus apraclonidine 0.5% for prevention of intraocular pressure elevations after anterior segment laser surgery.
OBJECTIVE: To compare the efficacy of brimonidine 0.2% with apraclonidine 0.5% in preventing intraocular pressure (IOP) elevations after anterior segment laser surgery. DESIGN: Double-masked, randomized clinical trial. PARTICIPANTS: Sixty-six patients underwent either laser peripheral iridotomy, argon laser trabeculoplasty, or neodymium:yttrium-aluminum-garnet laser capsulotomy. INTERVENTION: Eyes received either one drop of brimonidine 0.2% or apraclonidine 0.5% before laser surgery. MAIN OUTCOME MEASURES: Intraocular pressure, heart rate, and blood pressure were measured before laser surgery and at 1 hour, 3 hours, 24 hours, and 1 week after laser surgery. RESULTS: Before the laser treatment, 33 patients (50.0%) received brimonidine 0.2% and 33 patients (50.0%) received apraclonidine 0.5%. Eight of 33 patients (24.2%) in the brimonidine-treated group and 9 of 33 patients (27.3%) in the apraclonidine group had postoperative IOP increases of 5 mmHg or more. This was not statistically different (P = 0.80). By the time of last follow-up examination, 3 of 33 patients (9.1%) in the brimonidine-treated group and 3 of 33 patients (9.1%) in the apraclonidine group had IOP increases of 10 mmHg or more. This was also not statistically different (P > or = 0.95). The mean IOP reduction from baseline in the brimonidine group (-2.8 +/- 2.8 mmHg) was not statistically different (P = 0.55) compared with the mean IOP reduction in the apraclonidine group (-3.6 +/- 3.3 mmHg). There were no statistically significant changes in mean heart rate or blood pressure in either group except for a slight reduction in diastolic blood pressure at 1 hour (P = 0.005) in the brimonidine group (-5.2 +/- 7.4 mmHg) compared with the apraclonidine group (-0.2 +/- 6.4 mmHg). There were no clinically significant side effects noted in either group. CONCLUSIONS: A single preoperative drop of brimonidine 0.2% is as effective as apraclonidine 0.5% in preventing IOP elevation immediately after anterior segment laser surgery.
Adrenergic alpha-Agonists↗