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1.
J Nanosci Nanotechnol ; 14(10): 7855-9, 2014 Oct.
Article in English | MEDLINE | ID: mdl-25942880

ABSTRACT

The p-type (Bi0.2Sb0.8)2Te3 powders were mechanically alloyed and hot pressed at 500 degrees C for 30 minutes with dispersion of Si nanopowders up to 3 vol%. The thermal conductivity of the (Bi0.2Sb0.8)2Te3 nanocomposite was substantially reduced with dispersion of 0.3-3 vol% Si nanopowders due to the enhanced phonon scattering. The maximum dimensionless figure-of-merit of 1.32 at 75 degrees C was obtained for the (Bi0.2Sb0.8)2Te3 nanocomposite dispersed with 1 vol% Si nanopowders, compared to 1.08 of the specimen without Si nanopowder dispersion.


Subject(s)
Alloys/chemistry , Antimony/chemistry , Bismuth/chemistry , Electric Conductivity , Nanocomposites/chemistry , Silicon/chemistry , Tellurium/chemistry , Mechanical Phenomena , Temperature
2.
Hong Kong Med J ; 19(5): 407-15, 2013 Oct.
Article in English | MEDLINE | ID: mdl-23784530

ABSTRACT

OBJECTIVE: To report the treatment efficacy and toxicity profile of intensitymodulated radiation therapy in Chinese patients with clinically localised prostate cancer. DESIGN: Historical cohort study. SETTING: Oncology unit in a university teaching hospital in Hong Kong. PATIENTS: Patients with clinically localised prostate cancer undergoing intensity-modulated radiation therapy in our institution between May 2001 and November 2009 were reviewed. MAIN OUTCOME MEASURES: The 5-year biochemical failure­free survival, 5-year overall survival, as well as acute/late gastro-intestinal toxicities and genito-urinary toxicities. RESULTS: A total of 182 patients were treated with prostate intensitymodulated radiation therapy with or without whole-pelvic radiotherapy. The median follow-up was 44 months. The median patient age was 72 years. Overall survival of the cohort was 92% after 5 years. The favourable, intermediate, and unfavourable risk category distributions of the National Comprehensive Cancer Network were 21 (12%), 42 (23%), and 119 (65%), respectively. The 5-year actuarial biochemical failure­free survival rates for patients in these categories were 95%, 82%, and 80%, respectively. Multivariate analysis identified early tumour stage, low pre-treatment prostate-specific antigen levels, and the use of adjuvant androgen deprivation as independent prognostic factors for better biochemical failure­free survival. Grade 2 and 3 late gastro-intestinal/genito-urinary toxicities occurred in 8%/3% and 4%/3% of the patients, respectively. CONCLUSION: Intensity-modulated radiation therapy for prostate cancer is feasible and safe in the Chinese population. These data are consistent with the results of other series in Caucasian populations.


Subject(s)
Prostate-Specific Antigen/blood , Prostatic Neoplasms/radiotherapy , Radiotherapy, Intensity-Modulated/methods , Aged , Aged, 80 and over , Disease-Free Survival , Feasibility Studies , Follow-Up Studies , Gastrointestinal Diseases/epidemiology , Gastrointestinal Diseases/etiology , Hong Kong , Hospitals, University , Humans , Male , Middle Aged , Multivariate Analysis , Prognosis , Prostatic Neoplasms/pathology , Radiotherapy, Intensity-Modulated/adverse effects , Retrospective Studies , Survival Rate , Time Factors , Treatment Outcome , Urogenital System/radiation effects
3.
Ann Oncol ; 23(5): 1287-1292, 2012 May.
Article in English | MEDLINE | ID: mdl-21948811

ABSTRACT

BACKGROUND: Based on our previous work on the clinical activity of cetuximab in recurrent nasopharyngeal carcinoma (NPC), we evaluated the feasibility of adding cetuximab to concurrent cisplatin and intensity-modulated radiotherapy (IMRT) in locoregionally advanced NPC. PATIENTS AND METHODS: Patients with American Joint Committee on Cancer stage III-IVB NPC were given an initial dose of cetuximab (400 mg/m(2)) 7-10 days before receiving concurrent IMRT, weekly cisplatin (30 mg/m(2)/week) and cetuximab (250 mg/m(2)/week). RESULTS: Thirty patients (median age of 45 years) with stage III (67%), IVA (30%) and IVB (3%) nonkeratinizing NPC were enrolled. Grade 3-4 oropharyngeal mucositis occurred in 26 (87%) patients and 10 (33%) patients required short-term nasogastric feeding. Grade 3 radiotherapy-related dermatitis occurred in six patients (20%) and three patients (10%) had grade 3 cetuximab-related acneiform rash. These grade 3-4 skin and mucosal toxic effects were manageable and reversible. At a median follow-up of 31.8 months [95% confidence interval (CI) 26.2-32.1 months], the 2-year progression-free survival was 86.5% (95% CI 74.3% to 98.8%). CONCLUSIONS: Concurrent administration of cetuximab, weekly cisplatin and IMRT is a feasible strategy against locoregionally advanced NPC. Preliminary survival data compare favorably with historic data and further follow-up is warranted.


Subject(s)
Antibodies, Monoclonal/administration & dosage , Chemoradiotherapy/methods , Cisplatin/administration & dosage , Nasopharyngeal Neoplasms/therapy , Radiotherapy, Intensity-Modulated , Adult , Antibodies, Monoclonal/adverse effects , Antibodies, Monoclonal, Humanized , Antineoplastic Combined Chemotherapy Protocols/adverse effects , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Carcinoma , Cetuximab , Chemoradiotherapy/adverse effects , Cisplatin/adverse effects , Disease Progression , Disease-Free Survival , Feasibility Studies , Female , Follow-Up Studies , Humans , Male , Middle Aged , Nasopharyngeal Carcinoma , Nasopharyngeal Neoplasms/pathology , Neoplasm Recurrence, Local/therapy , Neoplasm Staging , Radiotherapy, Intensity-Modulated/methods , Young Adult
4.
Ann Oncol ; 20(11): 1854-9, 2009 Nov.
Article in English | MEDLINE | ID: mdl-19549713

ABSTRACT

BACKGROUND: Nasopharyngeal carcinoma (NPC) is a platinum-sensitive cancer and excision repair cross-complementing group 1 (ERCC1) polymorphisms have been shown to predict survival in several cancers following platinum therapy. PATIENTS AND METHODS: This multicenter study evaluated the activity of oxaliplatin and prolonged infusion of gemcitabine ('GEMOX' regimen) in recurrent NPC. Baseline blood samples were genotyped for the presence of ERCC1-118 gene polymorphisms. RESULTS: Forty-two patients were recruited, of whom most (61%) had metastatic disease. Of the 40 patients evaluated for response, the respective overall response and disease control rates were 56.1% and 90.2%. At a median follow-up of 14.8 months, the respective median overall survival and time to progression were 19.6 months [95% confidence interval (CI) = 12.8-22 months] and 9 months (95% CI = 7.3-10 months). Grade 3-4 toxic effects were uncommon. The distribution of ERCC1-118 genotypes from 29 patients was C/C (n = 17, 40.5%), C/T (n = 10, 23.8%) and T/T (n = 2, 4.8%). No differences in survival or response rates were found between genotypes. CONCLUSIONS: GEMOX is active in the treatment of recurrent NPC. Detection of single-nucleotide gene polymorphisms from genomic DNA in peripheral blood is feasible in NPC and further studies are warranted.


Subject(s)
Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Carcinoma/genetics , DNA-Binding Proteins/genetics , Drug Resistance, Neoplasm/genetics , Endonucleases/genetics , Nasopharyngeal Neoplasms/genetics , Adult , Aged , Carcinoma/drug therapy , Deoxycytidine/analogs & derivatives , Deoxycytidine/therapeutic use , Disease-Free Survival , Female , Humans , Kaplan-Meier Estimate , Male , Middle Aged , Nasopharyngeal Neoplasms/drug therapy , Neoplasm Recurrence, Local/drug therapy , Neoplasm Recurrence, Local/genetics , Organoplatinum Compounds/therapeutic use , Polymorphism, Single Nucleotide
5.
Oncogene ; 26(4): 554-70, 2007 Jan 25.
Article in English | MEDLINE | ID: mdl-16953232

ABSTRACT

Multiple endocrine neoplasia type 2A (MEN2A) is predisposed by mutations in the RET proto-oncogene. Low expression of the cyclin-dependent kinase inhibitor (CDKI) p27(Kip1) is present in thyroid tumors, and recent evidence demonstrates p27 downregulation by the active RET mutant, RET/PTC1, found in papillary thyroid carcinoma. This implicates decreased p27 activity as an important event during thyroid tumorigenesis. However, p27(-/-) mice develop MEN-like tumors only in combination with loss of another CDKI, p18(Ink4c). This suggests that p18 and p27 functionally collaborate in suppression of tumorigenesis, that loss of both is critical in the development of MEN tumors and that both p18 and p27 are regulated by RET. We report that induction of the constitutively active MEN2A-specific RET mutant, RET2A(C634R), correlates with reduced p18/p27, and elevated cyclin D protein levels, leading to increased CDK activity, increased pRb phosphorylation and proliferation under growth arrest conditions. Mechanistically, RET2A represses p18/p27 mRNA levels while elevating cyclin D1 mRNA levels. RET2A expression also correlates with decreased p27 protein stability. RET2A-mediated regulation of p18 and p27, but not of cyclins D1 and D2, requires functional mitogen-activated protein kinase signaling. Additionally, RET2A-dependent p18 repression is required and sufficient to increase cell proliferation. Perhaps most significantly, MEN2A adrenal tumors also display these changes in cell cycle expression profile, demonstrating the biological relevance of our cell culture studies. Our results demonstrate for the first time that RET2A regulates p18, and suggest that loss of not only p27 but also of p18 expression is a key step in MEN tumorigenesis.


Subject(s)
Cell Proliferation , Cyclin-Dependent Kinase Inhibitor p18/metabolism , Cyclin-Dependent Kinase Inhibitor p27/metabolism , Multiple Endocrine Neoplasia Type 2a/metabolism , Proto-Oncogene Proteins c-ret/physiology , Adrenal Gland Neoplasms/metabolism , Animals , Carcinoma, Medullary/metabolism , Cell Cycle , Down-Regulation , Humans , MAP Kinase Signaling System/physiology , Mice , Models, Biological , NIH 3T3 Cells , Oncogene Proteins/metabolism , Pheochromocytoma/metabolism , Proto-Oncogene Mas , Proto-Oncogene Proteins c-ret/metabolism , Transfection
6.
Eur J Gynaecol Oncol ; 24(6): 495-9, 2003.
Article in English | MEDLINE | ID: mdl-14658588

ABSTRACT

PURPOSE: To evaluate the efficacy of the addition of speculoscopy to a Pap smear in cervical cancer screening. METHODS: All women were screened using the Pap smear plus speculoscopy (PapSure) and colposcopy in the multicenter trial. The final diagnosis of each patient was based on a histological evaluation of the colposcopic target biopsy. Results were analyzed using a proportional compare test, sensitivity, specificity and predictive value with significant value determined at less than 0.05. RESULTS: Of 1,717 eligible cases, 26 cases had LGSIL and 16 cases had HGSIL. Of the Pap smears, five cases had LSIL and 14 cases had HGSIL. Of the combination of the PapSure, 23 cases had LGSIL and 16 cases had HGSIL. The sensitivity of the Pap smear to that of PapSure was calculated at 45.2% and 92.9%, respectively (p < 0.001). The estimated cost to detect a cervical lesion using PapSure is less than that of the Pap smear. CONCLUSION: The addition of speculoscopy along with a Pap smear screening results in early detection of cervical lesions in comparison to the Pap smear alone. This screening combination is also more cost-effective and requires fewer visits to the clinic in comparison to a Pap smear screening alone.


Subject(s)
Papanicolaou Test , Physical Examination/standards , Uterine Cervical Dysplasia/diagnosis , Uterine Cervical Neoplasms/diagnosis , Vaginal Smears/standards , Adult , Aged , Aged, 80 and over , Biopsy , Colposcopy/economics , Colposcopy/methods , Colposcopy/standards , Cost-Benefit Analysis , Female , Humans , Medical Records , Middle Aged , Physical Examination/economics , Physical Examination/instrumentation , Predictive Value of Tests , Retrospective Studies , Sensitivity and Specificity , Taiwan/epidemiology , Uterine Cervical Neoplasms/epidemiology , Uterine Cervical Neoplasms/etiology , Uterine Cervical Neoplasms/pathology , Vaginal Smears/economics , Vaginal Smears/instrumentation , Uterine Cervical Dysplasia/epidemiology , Uterine Cervical Dysplasia/etiology , Uterine Cervical Dysplasia/pathology
7.
J Sports Med Phys Fitness ; 43(3): 393-7, 2003 Sep.
Article in English | MEDLINE | ID: mdl-14625522

ABSTRACT

AIM: Effect of treadmill exercise on hippocampal cell proliferation under normal conditions has been well documented; however, this effect under alcohol intoxication conditions is not clarified, yet. In the present study, the effect of treadmill exercise on cell proliferation in the dentate gyrus in alcohol-intoxicated rats was investigated. EXPERIMENTAL DESIGN: comparative investigation on number of 5-bromo-2'-deoxyuridine (BrdU)-positive cells in the dentate gyrus 8 days after commencement. SETTING: animal laboratory. PARTICIPANTS: male Sprague-Dawley rats of 5 weeks in age weighing 150+/-10 g. INTERVENTION: animals were divided into 4 groups: the control-rest group, the control-exercise group, the alcohol-treated-rest group, and the alcohol-treated-exercise group. Animals of the alcohol-treated groups were injected intraperitoneally with alcohol (2 g/kg) once a day for 3 days. All animals were injected BrdU (50 mg/kg) intraperitoneally, and rats of exercise groups were made to run on treadmill for 30 min each day for 5 days following alcohol administration. MEASURES: mean number of BrdU-positive cells in dentate gyrus was observed via immunohistochemistry. RESULTS: Treadmill exercise significantly increased the number of BrdU-positive cells in the dentate gyrus. Also, treatment with alcohol for 3 days inhibited cell proliferation and treadmill exercise alleviated alcohol-induced inhibition of new cell formation. CONCLUSION: These results suggest the possibility that treadmill exercise may help in improvement following alcohol-induced brain damage.


Subject(s)
Alcoholic Intoxication/pathology , Alcoholic Intoxication/physiopathology , Dentate Gyrus/pathology , Exercise Test , Hippocampus/pathology , Alcoholic Intoxication/blood , Analysis of Variance , Animals , Ethanol/blood , Immunohistochemistry , Male , Physical Conditioning, Animal , Rats , Rats, Sprague-Dawley
8.
Eur J Gynaecol Oncol ; 23(1): 35-6, 2002.
Article in English | MEDLINE | ID: mdl-11878287

ABSTRACT

INTRODUCTION: Doctors are usually reluctant to perform a vulvar biopsy on a patient with non-specific chronic vulvitis--especially because of the rarity of vulvar malignancy in young women--until the lesion is suspected of being malignant. Therefore, most cases of extramammary Paget's disease (EMPD) were originally misdiagnosed as chronic and recurrent vulvar lesions. Late diagnosis of invasive lesions occurring in elderly females have resulted in cases of death. CASE: A 37-year-old patient showed an extended lesion on the vulva and perineum. In addition, abnormal cells were found from a vulvar scrape smear, and a following punch biopsy was used to diagnose and determine the extension of the disease. CONCLUSION: Diagnosis and demarcation of EMPD remain difficult due to the multifocal lesions and subtle nature of the disease. Brush sampling taken from suspicious areas can be a guide for multiple biopsies to demarcate the lesion before major surgery. A brush biopsy is presented as a first-step method to detect vulvar malignancy.


Subject(s)
Neoplasm Invasiveness/pathology , Paget Disease, Extramammary/pathology , Vulvar Neoplasms/pathology , Adult , Biopsy, Needle , Female , Follow-Up Studies , Humans , Immunohistochemistry , Paget Disease, Extramammary/surgery , Sensitivity and Specificity , Treatment Outcome , Vaginal Smears , Vulvar Neoplasms/surgery
9.
Opt Lett ; 19(13): 960-2, 1994 Jul 01.
Article in English | MEDLINE | ID: mdl-19844501

ABSTRACT

We report synchronously mode-locked subpicosecond and continuous-wave color-center laser operation in the 1.8-2.4-microm wavelength range. For active materials we use (F(2)(+))(H) centers in KBr:O(2)(-) and (F(2)(+))(AH) centers in KBr:Na(+):O(2)(-) crystals. When the lasers are pumped with a continuous-wave or mode-locked NaCI (F(2)(+))(H)-center laser in a cascaded configuration, laser operation is obtained over the combined tuning range of 1.8-2.4 microm, with output powers as high as 150 mW. When synchronously mode locked with ~5-ps pump pulses, both KBr lasers yield typically ~1-ps pulse widths over the entire tuning range. Pulses as short as ~400 fs could be obtained at the expense of higher noise levels.

10.
Appl Opt ; 28(15): 3024-9, 1989 Aug 01.
Article in English | MEDLINE | ID: mdl-20555646

ABSTRACT

The optical depolarizing properties of simulated stratospheric aerosols were studied in laboratory laser (0.633 microm) backscattering experiments for application to polarization lidar observations. Clouds composed of sulfuric acid solution droplets, some treated with ammonia gas, were observed during evaporation. The results indicate that the formation of minute ammonium sulfate particles from the evaporation of acid droplets produces linear depolarization ratios of delta approximately 0.02, but delta approximately 0.10-0.15 are generated from acid droplet crystallization effects associated with recycled aerosols and the introduction of ammonia gas into the chamber. It is concluded that partially crystallized sulfuric acid droplets are a likely candidate for explaining the lidar delta approximately 0.10 values that have been observed in the lower stratosphere in the absence of the relatively strong backscattering from homogeneous sulfuric acid droplet (delta approximately 0) or ice crystal (delta approximately 0.5) clouds.

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