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1.
Clin Case Rep ; 11(5): e7182, 2023 May.
Article in English | MEDLINE | ID: mdl-37180317

ABSTRACT

Sarcomatoid sweat gland carcinomas are rare among cutaneous cancers, with less than 20 cases described. A 54-year-old woman with sarcomatoid sweat gland carcinoma of the right upper extremity suffered extensive recurrence at 15 months, unresponsive to chemotherapy. There is no standard treatment or chemotherapy regimens for metastatic sweat gland carcinoma.

2.
Public Health ; 219: 44-52, 2023 Jun.
Article in English | MEDLINE | ID: mdl-37099967

ABSTRACT

BACKGROUND: Public housing estate is a key determinant of community health risk in American/European cities. However, how forms/characteristics of compact/hilly public housing's neighbourhoods affect dementia among Asian seniors was underestimated. DESIGN: This was a cross-sectional study. METHODS: A total of 2,077 seniors living in Hong Kong's public housing estates were included. Dementia was measured by a Cantonese version of Montreal - Cognitive Assessment. Built environment was measured based on three dimensions (greenery, walkability, accessibility), including 11 metrics. Circular buffers (without walking paths) and service areas (considering walking paths) with two-dimensional/three-dimensional (terrain) adjustment were applied to quantify forms/characteristics of neighbourhoods. Two spatial buffers were applied: immediate distance (200 m) and walkable distance (500 m). Exposure-by-exposure regressions were applied to evaluate the associations between form/characteristics of neighbourhood and dementia. RESULTS: Forms/characteristics without considering walking paths may overestimate health benefits from built environment. For circular buffers, higher percentage of building coverage, higher land use mix and more community/transportation/leisure facilities were negatively associated with dementia. All measures of greenery were positively associated with dementia. For service areas, measures of walkability and accessibility became insignificant except more community facilities at the immediate distance. Furthermore, terrain effect was insignificant when it was compared with the impacts of walking paths. CONCLUSION: Dementia among seniors in hilly public housing estates was negatively associated with neighbourhood's walkability and accessibility and was influenced by walking paths. For healthy ageing, improved forms/characteristics of public housing neighbourhoods should include more accessible spaces and community facilities along walking paths for physical activities and basic daily needs.


Subject(s)
Dementia , Public Housing , Humans , Cross-Sectional Studies , Hong Kong/epidemiology , Environment Design , Walking , Residence Characteristics , Dementia/epidemiology
3.
East Asian Arch Psychiatry ; 31(4): 97-104, 2021 Dec.
Article in English | MEDLINE | ID: mdl-34987120

ABSTRACT

OBJECTIVES: To determine the psychometric properties of the Chinese version of the work and social adjustment scale (CWSAS) in outpatients with common mental disorders, and to evaluate the correlations of CWSAS with Physical Health Questionnaire-9 (PHQ-9), General Anxiety Disorder-7 (GAD-7), World Health Organization Five Well-being Index (WHO-5), and Chinese version of the Perceived Stress Scale-10 (CPSS-10). METHODS: Forward and backward translations of the CWSAS was performed. Between October 2018 and March 2020, 252 outpatients with a common mental disorder who had a job or a job plan were recruited from two psychiatric centres in Hong Kong. Participants were asked to complete the CWSAS, PHQ-9, GAD-7, WHO-5, and CPSS-10. Classical test theory and Rasch analysis were undertaken to determine the psychometric properties of the CWSAS and its correlations with other tools. RESULTS: Principal component analysis revealed that the CWSAS was a one-factor structure and showed adequate convergent and discriminant validities, internal consistency, item-total correlation, and inter-item correlation. There was a significant group difference in terms of employment status. CPSS-10 and PHQ-9 were predictors for CWSAS score. The CWSAS was a distinct factor among other outcome measures. Rasch analysis indicated that the CWSAS was well-targeted and unidimensional. The CWSAS had an adequate person separation index, item separation index, person reliability, and item reliability. No categorical disordering was found, whereas inadequate adjacent threshold distance was reported. The item of ability to work indicated a noticeable differential item functioning in employment status and main source of finance. CONCLUSION: The CWSAS is psychometrically appropriate to measure functional outcomes in outpatients with common mental disorders.


Subject(s)
Mental Disorders , Outpatients , Hong Kong , Humans , Psychometrics , Reproducibility of Results , Social Adjustment , Surveys and Questionnaires
4.
AJNR Am J Neuroradiol ; 41(3): 515-521, 2020 03.
Article in English | MEDLINE | ID: mdl-32184223

ABSTRACT

BACKGROUND AND PURPOSE: We evaluated modifications to our contrast-enhanced MR imaging grading system for symptomatic patients with suspected nasopharyngeal carcinoma, aimed at improving discrimination of early-stage cancer and benign hyperplasia. We evaluated a second non-contrast-enhanced MR imaging grading system for asymptomatic patients from nasopharyngeal carcinoma plasma screening programs. MATERIALS AND METHODS: Dedicated nasopharyngeal MR imaging before (plain scan system) and after intravenous contrast administration (current and modified systems) was reviewed in patients from a nasopharyngeal carcinoma-endemic region, comprising 383 patients with suspected disease without nasopharyngeal carcinoma and 383 patients with nasopharyngeal carcinoma. The modified and plain scan systems refined primary tumor criteria, added a nodal assessment, and expanded the system from 4 to 5 grades. The overall combined sensitivity and specificity of the 3 systems were compared using the extended McNemar test (a χ2 value [Formula: see text]> 5.99 indicates significance). RESULTS: The current, modified, and plain scan MR imaging systems yielded sensitivities of 99.74%, 97.91%, and 97.65%, respectively, and specificities of 63.45%, 89.56% and 86.42%, respectively. The modified system yielded significantly better performance than the current ([Formula: see text] = 122) and plain scan ([Formula: see text] = 6.1) systems. The percentages of patients with nasopharyngeal carcinoma in grades 1-2, grade 3, and grades 4-5 for the modified and plain scan MR imaging systems were 0.42% and 0.44%; 6.31% and 6.96%; and 90.36% and 87.79%, respectively. No additional cancers were detected after contrast administration in cases of a plain scan graded 1-2. CONCLUSIONS: We propose a modified MR imaging grading system that improves diagnostic performance for nasopharyngeal carcinoma detection. Contrast was not valuable for low MR imaging grades, and the plain scan shows potential for use in screening programs.


Subject(s)
Early Detection of Cancer/methods , Image Interpretation, Computer-Assisted/methods , Magnetic Resonance Imaging/methods , Nasopharyngeal Carcinoma/diagnostic imaging , Nasopharyngeal Neoplasms/diagnostic imaging , Adolescent , Adult , Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Retrospective Studies , Sensitivity and Specificity , Young Adult
5.
Ann Oncol ; 30(6): 977-982, 2019 06 01.
Article in English | MEDLINE | ID: mdl-30912815

ABSTRACT

BACKGROUND: Early-stage nasopharyngeal carcinoma (NPC) evades detection when the primary tumor is hidden from view on endoscopic examination. Therefore, in a prospective study of subjects being screened for NPC using plasma Epstein-Barr virus (EBV) DNA, we conducted a study to investigate whether magnetic resonance imaging (MRI) could detect endoscopically occult NPC. PATIENTS AND METHODS: Participants with persistently positive EBV DNA underwent endoscopic examination and biopsy when suspicious for NPC, followed by MRI blinded to the endoscopic findings. Participants with a negative endoscopic examination and positive MRI were recalled for biopsy or surveillance. Diagnostic performance was assessed by calculating sensitivity, specificity and accuracy, based on the histologic confirmation of NPC in the initial study or in a follow-up period of at least two years. RESULTS: Endoscopic examination and MRI were performed on 275 participants, 34 had NPC, 2 had other cancers and 239 without cancer were followed-up for a median of 36 months (24-60 months). Sensitivity, specificity and accuracy were 76.5%, 97.5% and 94.9%, respectively, for endoscopic examination and 91.2%, 97.5% and 96.7%, respectively, for MRI. NPC was detected only by endoscopic examination in 1/34 (2.9%) participants (a participant with stage I disease), and only by MRI in 6/34 (17.6%) participants (stage I = 4, II = 1, III = 1), two of whom had stage I disease and follow-up showing slow growth on MRI but no change on endoscopic examination for 36 months. CONCLUSION: MRI has a complementary role to play in NPC detection and can enable the earlier detection of endoscopically occult NPC.


Subject(s)
Epstein-Barr Virus Infections/diagnosis , Nasopharyngeal Carcinoma/diagnosis , Nasopharyngeal Neoplasms/diagnosis , Adult , DNA, Viral/blood , DNA, Viral/genetics , Early Detection of Cancer/methods , Endoscopy/methods , Epstein-Barr Virus Infections/blood , Epstein-Barr Virus Infections/pathology , Epstein-Barr Virus Infections/virology , Follow-Up Studies , Herpesvirus 4, Human/genetics , Herpesvirus 4, Human/isolation & purification , Humans , Magnetic Resonance Imaging/methods , Male , Middle Aged , Nasopharyngeal Carcinoma/diagnostic imaging , Nasopharyngeal Carcinoma/surgery , Nasopharyngeal Carcinoma/virology , Nasopharyngeal Neoplasms/diagnostic imaging , Nasopharyngeal Neoplasms/surgery , Nasopharyngeal Neoplasms/virology , Prognosis , Prospective Studies , Viral Load
6.
Neuroradiology ; 60(10): 1093-1096, 2018 Oct.
Article in English | MEDLINE | ID: mdl-30132019

ABSTRACT

Cerebral venous sinus thrombosis is an uncommon cause of stroke with high morbidity and mortality rates from venous infarction, intracranial hemorrhage, and extensive cerebral edema. Endovascular treatment with various devices has been proposed as a salvage treatment when standard medical treatment with systemic anticoagulation is ineffective, especially in long segment dural sinus thrombosis. We describe our technique of transvenous endovascular aspiration thrombectomy with large bore thrombectomy catheters, followed by placement of microcatheter for local thrombolytic infusion at the site of thrombosis. We report a retrospective study of angiographic and clinical outcome of six consecutive patients treated with this approach. Endovascular aspiration thrombectomy with large bore catheters followed by continuous local thrombolytic infusion appeared to be a safe and effective salvage treatment for selected patients with cerebral dural venous sinus thrombosis refractory to medical treatment.


Subject(s)
Magnetic Resonance Imaging , Sinus Thrombosis, Intracranial/diagnostic imaging , Sinus Thrombosis, Intracranial/therapy , Thrombectomy/methods , Thrombolytic Therapy/methods , Adult , Aged , Combined Modality Therapy , Female , Humans , Male , Middle Aged , Retrospective Studies , Salvage Therapy , Treatment Outcome
7.
Oncogene ; 34(33): 4403-11, 2015 Aug 13.
Article in English | MEDLINE | ID: mdl-25417706

ABSTRACT

The E2 ubiquitin conjugating enzyme Ubc13 and the E3 ubiquitin ligases Rad18 and Rnf8 promote homologous recombination (HR)-mediated double-strand break (DSB) repair by enhancing polymerization of the Rad51 recombinase at γ-ray-induced DSB sites. To analyze functional interactions between the three enzymes, we created RAD18(-/-), RNF8(-/-), RAD18(-/-)/RNF8(-/-) and UBC13(-/-)clones in chicken DT40 cells. To assess the capability of HR, we measured the cellular sensitivity to camptothecin (topoisomerase I poison) and olaparib (poly(ADP ribose)polymerase inhibitor) because these chemotherapeutic agents induce DSBs during DNA replication, which are repaired exclusively by HR. RAD18(-/-), RNF8(-/-) and RAD18(-/-)/RNF8(-/-) clones showed very similar levels of hypersensitivity, indicating that Rad18 and Rnf8 operate in the same pathway in the promotion of HR. Although these three mutants show less prominent defects in the formation of Rad51 foci than UBC13(-/-)cells, they are more sensitive to camptothecin and olaparib than UBC13(-/-)cells. Thus, Rad18 and Rnf8 promote HR-dependent repair in a manner distinct from Ubc13. Remarkably, deletion of Ku70, a protein essential for nonhomologous end joining (NHEJ) significantly restored tolerance of RAD18(-/-) and RNF8(-/-) cells to camptothecin and olaparib without affecting Rad51 focus formation. Thus, in cellular tolerance to the chemotherapeutic agents, the two enzymes collaboratively promote DSB repair by HR by suppressing the toxic effect of NHEJ on HR rather than enhancing Rad51 focus formation. In contrast, following exposure to γ-rays, RAD18(-/-), RNF8(-/-), RAD18(-/-)/RNF8(-/-) and UBC13(-/-)cells showed close correlation between cellular survival and Rad51 focus formation at DSB sites. In summary, the current study reveals that Rad18 and Rnf8 facilitate HR by two distinct mechanisms: suppression of the toxic effect of NHEJ on HR during DNA replication and the promotion of Rad51 focus formation at radiotherapy-induced DSB sites.


Subject(s)
DNA End-Joining Repair/genetics , DNA-Binding Proteins/genetics , Homologous Recombination/genetics , Rad51 Recombinase/genetics , Antigens, Nuclear/genetics , Cell Line, Tumor , DNA Repair/genetics , DNA Replication/genetics , HCT116 Cells , Humans , Ku Autoantigen , Ubiquitin-Conjugating Enzymes/genetics , Ubiquitin-Protein Ligases/genetics , Ubiquitination/genetics
8.
Diabetologia ; 56(3): 542-52, 2013 Mar.
Article in English | MEDLINE | ID: mdl-23238790

ABSTRACT

AIMS/HYPOTHESIS: The paucity of information on the epigenetic barriers that are blocking reprogramming protocols, and on what makes a beta cell unique, has hampered efforts to develop novel beta cell sources. Here, we aimed to identify enhancers in pancreatic islets, to understand their developmental ontologies, and to identify enhancers unique to islets to increase our understanding of islet-specific gene expression. METHODS: We combined H3K4me1-based nucleosome predictions with pancreatic and duodenal homeobox 1 (PDX1), neurogenic differentiation 1 (NEUROD1), v-Maf musculoaponeurotic fibrosarcoma oncogene family, protein A (MAFA) and forkhead box A2 (FOXA2) occupancy data to identify enhancers in mouse islets. RESULTS: We identified 22,223 putative enhancer loci in in vivo mouse islets. Our validation experiments suggest that nearly half of these loci are active in regulating islet gene expression, with the remaining regions probably poised for activity. We showed that these loci have at least nine developmental ontologies, and that islet enhancers predominately acquire H3K4me1 during differentiation. We next discriminated 1,799 enhancers unique to islets and showed that these islet-specific enhancers have reduced association with annotated genes, and identified a subset that are instead associated with novel islet-specific long non-coding RNAs (lncRNAs). CONCLUSIONS/INTERPRETATIONS: Our results indicate that genes with islet-specific expression and function tend to have enhancers devoid of histone methylation marks or, less often, that are bivalent or repressed, in embryonic stem cells and liver. Further, we identify a subset of enhancers unique to islets that are associated with novel islet-specific genes and lncRNAs. We anticipate that these data will facilitate the development of novel sources of functional beta cell mass.


Subject(s)
Islets of Langerhans/metabolism , Animals , Basic Helix-Loop-Helix Transcription Factors/metabolism , Chromatin Immunoprecipitation , Enhancer Elements, Genetic/genetics , Hepatocyte Nuclear Factor 3-beta/metabolism , Homeodomain Proteins/metabolism , Mice , Nerve Tissue Proteins/metabolism , Trans-Activators/metabolism
9.
Arch Oral Biol ; 57(2): 177-87, 2012 Feb.
Article in English | MEDLINE | ID: mdl-21963335

ABSTRACT

UNLABELLED: Matrix proteoglycans define matrix structure, mineralization, and resulting biomechanics of tissues and their attachment sites. OBJECTIVE: We therefore investigated physical and (bio)chemical differences in enamel and periodontal tissues/attachment sites from mice that lack a specific nanoscale small leucine-rich proteoglycan (SLRPs) named biglycan (BGN). DESIGN: Experimental groups consisted of N=4, biglycan knockout (BGNKO) and N=5 wildtype (WT) 8-week-old, male C3H mice. Morphology, histochemical and mechanical analyses were performed through micro X-ray computed tomography (Micro XCT™), immunohistochemistry, and microindentation. Unless mentioned otherwise, all differences between BGNKO and WT were demonstrated to be statistically significant through Student's t-tests with a 95% confidence interval (P≤0.05). RESULTS: Histomorphometry performed by using Micro XCT™ images indicated significantly higher BGNKO-enamel (0.46 ± 0.03mm(3)) and BGNKO-root (1.81 ± 0.10mm(3)) volumes compared to WT-enamel (0.37 ± 0.02mm(3)) and WT-root (1.65 ± 0.07mm(3)). BGNKO tooth size was relatively larger than WT mice, with no significant difference between skull sizes. Immunohistochemistry indicated BGN expression in the periodontal ligament (PDL), alveolar bone (AB), at the bone-PDL and cementum-PDL attachment sites in WT mice. Deeper AB resorption pits within interdental region of BGNKO specimens compared to WT resulting in significant differences in PDL-space of BGNKO (93 ± 13µm) and WT (74 ± 11µm) were observed. Microhardness of BGNKO-enamel (2.46 ± 0.60GPa) and BGNKO-AB (0.52 ± 0.10GPa) was significantly lower than WT-enamel (2.67 ± 0.60GPa) and WT-AB (0.54 ± 0.10GPa). CONCLUSION: Results indicate that BGNKO-mice exhibit significant differences in tissue properties compared to WT-mice.


Subject(s)
Biglycan/metabolism , Dental Cementum/metabolism , Dental Enamel Proteins/metabolism , Dental Enamel/metabolism , Extracellular Matrix Proteins/metabolism , Periodontal Ligament/metabolism , Tooth Root/metabolism , Alveolar Bone Loss/metabolism , Animals , Biglycan/chemistry , Dental Enamel/anatomy & histology , Immunohistochemistry , Mice , Mice, Knockout , Tomography, X-Ray Computed , Tooth Calcification , Tooth Root/anatomy & histology
10.
J Clin Pathol ; 62(4): 308-13, 2009 Apr.
Article in English | MEDLINE | ID: mdl-19329710

ABSTRACT

The discovery of cell-free circulating fetal nucleic acids in maternal plasma has opened up new possibilities in non-invasive prenatal diagnosis. The rapid advancement of this field in the past decade is catalysed by the discovery of new classes of fetal nucleic acid markers and technological developments in nucleic acid detection and amplification. In this review, some of the more significant recent developments in this field will be discussed, including the detection of single molecule, chromosomal aneuploidies, single nucleotide variations and placental microRNAs in maternal plasma.


Subject(s)
Fetal Diseases/diagnosis , Nucleic Acids/blood , Prenatal Diagnosis/methods , Aneuploidy , Biomarkers/blood , Female , Humans , MicroRNAs/blood , Polymorphism, Single Nucleotide , Pregnancy
12.
J Biomed Mater Res A ; 81(2): 310-6, 2007 May.
Article in English | MEDLINE | ID: mdl-17120215

ABSTRACT

The effects of an oral p38 mitogen-activated protein kinase (MAPK) inhibitor and polyethylene particles separately and together on tissue differentiation in the bone harvest chamber (BHC) in rabbits over a 3-week treatment period were investigated. The harvested tissue was analyzed histomorphometrically for markers of bone formation (percentage of bone area), osteoblasts (alkaline phosphatase staining), and osteoclasts (CD51, the alpha chain of the vitronectin receptor). Polyethylene particles decreased the percentage of bone ingrowth and staining for alkaline phosphatase. The p38 MAPK inhibitor alone decreased alkaline phosphatase staining. When the oral p38 MAPK inhibitor was given and the chamber contained polyethylene particles, there was a suppression of bone ingrowth and alkaline phosphatase staining. In contrast to oral non-steroidal anti-inflammatory drugs (NSAIDs) and local Interleukin-1 receptor antagonist (IL-1ra) administration, the oral p38 MAPK inhibitor alone did not suppress bone formation when given during the initial phase of tissue differentiation. Particle-induced inflammation and the foreign body reaction were not curtailed when the p38 MAPK inhibitor was given simultaneously with particles. Additional experiments are needed to establish the efficacy of p38 MAPK inhibitor administration on mitigating an established inflammatory and foreign body reaction that parallels the clinical situation more closely.


Subject(s)
Osseointegration/drug effects , Protein Kinase Inhibitors/pharmacology , p38 Mitogen-Activated Protein Kinases/antagonists & inhibitors , Administration, Oral , Animals , Biocompatible Materials , Diffusion Chambers, Culture , Joint Prosthesis/adverse effects , Male , Materials Testing , Osteolysis/etiology , Osteolysis/prevention & control , Polyethylenes , Prosthesis Failure , Protein Kinase Inhibitors/administration & dosage , Rabbits , Tibia/pathology , Tibia/surgery , Tissue Engineering
13.
Acta Neurochir Suppl ; 95: 471-4, 2005.
Article in English | MEDLINE | ID: mdl-16463903

ABSTRACT

Much research interest has been shown in recent years for the development of molecular diagnostic strategies based on the analysis of DNA/RNA molecules that are present in the plasma/serum of human subjects. Reported applications include the diagnosis, prognostication or monitoring of malignancies and pregnancy-associated complications. While researchers have speculated that cell death is a potential mechanism that leads to the release of DNA/RNA into the circulation, studies have demonstrated that indeed increased amounts of plasma DNA and RNA could be detected in patients sustaining acute traumatic injuries. The degree of plasma DNA elevation correlated with the severity of injury. Similarly, plasma DNA concentrations have been shown to correlate with indices of prognostic significance in patients with acute stroke. It is expected that new diagnostic markers based on plasma RNA detection could be developed for the evaluation of acute pathologies.


Subject(s)
Blood Chemical Analysis/methods , Neoplasms/blood , Neoplasms/diagnosis , Nucleic Acids/blood , Stroke/blood , Stroke/diagnosis , Animals , Biomarkers/blood , Humans
15.
Lancet ; 362(9398): 1807-8, 2003 Nov 29.
Article in English | MEDLINE | ID: mdl-14654320

ABSTRACT

Severe acute respiratory syndrome (SARS) is a global health concern. In Hong Kong, two major outbreaks, one hospital based and the other in the Amoy Gardens apartments, were identified. The frequency of diarrhoea, admission to intensive care, and mortality differed significantly between the two outbreaks. We did genomic sequencing for viral isolates from five Amoy Gardens patients. The virus sequence was identical in four of these five patients. The sequence data from one hospital case and the four identical community cases had only three nucleotide differences. Alterations in the SARS coronavirus genome are unlikely to have caused the distinctive clinical features of the Amoy Gardens patients, and these results highlight the importance of non-viral genomic factors in this outbreak.


Subject(s)
Disease Outbreaks/statistics & numerical data , Genome, Viral , Severe Acute Respiratory Syndrome/virology , Severe acute respiratory syndrome-related coronavirus/genetics , Base Sequence/genetics , Cross Infection/virology , Hong Kong/epidemiology , Humans , Severe Acute Respiratory Syndrome/diagnosis , Severe Acute Respiratory Syndrome/epidemiology
16.
Transplant Proc ; 35(7): 2415-7, 2003 Nov.
Article in English | MEDLINE | ID: mdl-14611974

ABSTRACT

Allograft nephropathy leads to progressive renal injury and ultimate graft loss. In native kidney disease, the use of angiotensin-converting enzyme inhibitors (ACEi) or angiotensin receptor blockers (ARB) is beneficial in retarding the decline of renal function. We reviewed a cohort of renal transplant recipients who were prescribed either an ACEi or ARB for biopsy-proven allograft nephropathy. Patients were followed from time of initiation of ACEi/ARB and were stratified based on biopsy findings. Outcomes of interest included safety, allograft survival, renal function, and rate of renal function decline pre- and post-ACEi/ARB. The 5-year allograft survival after biopsy was 83%. Mean serum creatinine was 2.2 +/- 1.1 mg/dL (range 1.0 to 4.3) at time of biopsy and 2.6 +/- 1.2 mg/dL (1.2 to 6.5) at last follow-up. The mean slope of the creatinine versus time (SD) was 2.43 (7.93) in the 12 months prior to therapy and 1.45 (3.66) following therapy, with the absolute difference in slope -3.38 (6.06) (P =.0004). We conclude that treatment with ACEi/ARB is beneficial in the management of allograft nephropathy.


Subject(s)
Kidney Transplantation/pathology , Renin-Angiotensin System/drug effects , Angiotensin Receptor Antagonists , Angiotensin-Converting Enzyme Inhibitors/therapeutic use , Biopsy , Chronic Disease , Creatinine/blood , Creatinine/urine , Humans , Postoperative Complications/classification , Postoperative Complications/pathology , Retrospective Studies
17.
J Membr Biol ; 194(3): 187-97, 2003 Aug 01.
Article in English | MEDLINE | ID: mdl-14502431

ABSTRACT

Claudins are a family of proteins involved in forming tight junctions between cells. Here we describe two forms of claudin-7 (CLDN-7), a full-length form of CLDN-7 with 211 amino-acid residues and a C-terminal truncated form with 158 amino-acid residues. These two forms of CLDN-7 are able to regulate the expression of a tissue-specific protein, the prostate-specific antigen (PSA), in the LNCaP prostate cancer cell line. We also found that the expression of CLDN-7 is responsive to androgen stimulation in the LNCaP cell line, suggesting that this protein is involved in the regulatory mechanism of androgen. Both forms of claudin-7 are expressed in human prostate, kidney and lung samples, and in most samples, the full-length form of claudin-7 was predominant. However, in some prostate samples from healthy individuals, the truncated form of claudin-7 is predominantly expressed. Our results demonstrated that unlike other claudins, CLDN-7 has both structural and regulatory functions, and the two forms of CLDN-7 may be related to cell differentiation in organ development.


Subject(s)
Adenocarcinoma/pathology , Gene Expression Regulation, Neoplastic/physiology , Membrane Proteins/physiology , Neoplasm Proteins/physiology , Prostate-Specific Antigen/biosynthesis , Prostatic Neoplasms/pathology , Adenocarcinoma/metabolism , Amino Acid Sequence , Cell Line, Tumor/drug effects , Cell Line, Tumor/metabolism , Claudins , DNA, Complementary/genetics , Gene Expression Profiling , Humans , Male , Membrane Proteins/biosynthesis , Membrane Proteins/chemistry , Membrane Proteins/genetics , Molecular Sequence Data , Neoplasm Proteins/biosynthesis , Neoplasm Proteins/chemistry , Neoplasm Proteins/genetics , Organ Specificity , Prostate-Specific Antigen/genetics , Prostatic Neoplasms/metabolism , Protein Isoforms/chemistry , Protein Isoforms/physiology , Protein Structure, Tertiary , RNA, Messenger/biosynthesis , RNA, Neoplasm/biosynthesis , Recombinant Fusion Proteins/genetics , Recombinant Fusion Proteins/physiology , Structure-Activity Relationship , Subtraction Technique , Tight Junctions/physiology , Transfection
18.
Hong Kong Med J ; 8(3): 172-6, 2002 Jun.
Article in English | MEDLINE | ID: mdl-12055361

ABSTRACT

OBJECTIVES: To evaluate performance characteristics of the newly available handheld combined glucose and ketone meter for beta-hydroxybutyrate measurement. DESIGN: Laboratory method evaluation. MAIN OUTCOME MEASURES: Accuracy of beta-hydroxybutyrate measurement and effect of acetoacetate interference at clinically important beta-hydroxybutyrate levels. RESULTS: Deming regression analysis of beta-hydroxybutyrate measurements assessed by the ketone sensor and a laboratory enzymatic method revealed a coefficient of determination of 0.989 (P<0.001). Passing-Bablok regression analysis showed a linear relationship between the two methods, ie Y= -0.32+1.13X. The 95% confidence interval of the slope and y-intercept were: slope=1.13 (95% confidence interval, 1.04 to 1.22); intercept= -0.32 (95% confidence interval, -0.59 to -0.06). The Bland-Altman plot showed a small proportional bias between the two methods. The mean bias +/-2 standard deviations was between -0.53 and 0.67 mmol/L. Beta-hydroxybutyrate measurements made by the sensor were linear up to 6 mmol/L. Replicate analysis of two samples spiked with 3.6 mmol/L and 0.8 mmol/L of beta-hydroxybutyrate resulted in coefficients of variation of 3.3% and 13%, respectively. The presence of acetoacetate caused a negative interference in beta-hydroxybutyrate measurement. Beta-hydroxybutyrate recovery was 97.0% and 90.7% when the ketone body ratios were 6:1 and 3:1, respectively. CONCLUSION: The analytical performance of the sensor, when operated according to manufacturer's instructions, could meet the needs of point-of-care beta-hydroxybutyrate measurement. Additional clinical studies are needed to assess the benefits of introducing such an assay in a clinical setting.


Subject(s)
3-Hydroxybutyric Acid/blood , Autoanalysis/instrumentation , Biosensing Techniques/standards , Point-of-Care Systems/standards , Computer Peripherals , Diabetic Ketoacidosis/diagnosis , Humans
19.
Eur J Cancer ; 38(2): 240-57, 2002 Jan.
Article in English | MEDLINE | ID: mdl-11803141

ABSTRACT

There is overwhelming evidence that solid human tumours grow within a unique micro-environment. This environment is characterised by an abnormal vasculature, which leads to an insufficient supply of oxygen and nutrients to the tumour cells. These characteristics of the environment limit the effectiveness of both radiotherapy and chemotherapy. Measurement of the oxygenation status of human tumours has unequivocally demonstrated the importance of this parameter on patient prognosis. Tumour hypoxia has been shown to be an independent prognostic indicator of poor outcome in prostate, head and neck and cervical cancers. Recent laboratory and clinical data have shown that hypoxia is also associated with a more malignant phenotype, affecting genomic stability, apoptosis, angiogenesis and metastasis. Several years ago, scientists realised that the unique properties within the tumour micro-environment could provide the basis for tumour-specific therapies. Efforts that are underway to develop therapies that exploit the tumour micro-environment can be categorised into three groups. The first includes agents that exploit the environmental changes that occur within the micro-environment such as hypoxia and reduced pH. This includes bioreductive drugs that are specifically toxic to hypoxic cells, as well as hypoxia-specific gene delivery systems. The second category includes therapies designed to exploit the unique properties of the tumour vasculature and include both angiogenesis inhibitors and vascular targeting agents. The final category includes agents that exploit the molecular and cellular responses to hypoxia. For example, many genes are induced by hypoxia and promoter elements from these genes can be used for the selective expression of therapeutic proteins in hypoxic tumour cells. An overview of the various properties ascribed to tumour hypoxia and the current efforts underway to exploit hypoxia for improving cancer treatment will be discussed.


Subject(s)
Cell Hypoxia , Neoplasms/blood supply , Neoplasms/therapy , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Carbon Dioxide/administration & dosage , Combined Modality Therapy/methods , Gene Expression , Humans , Neovascularization, Pathologic , Niacinamide/administration & dosage , Oxygen/administration & dosage , Oxygen/analysis , Prognosis , Radiation-Sensitizing Agents/therapeutic use
20.
Ann N Y Acad Sci ; 945: 156-60, 2001 Sep.
Article in English | MEDLINE | ID: mdl-11708472

ABSTRACT

We have recently reported the development of a multiplex, real-time quantitative polymerase chain reaction (PCR) assay for RhD zygosity determination based on the coamplification and quantification of RHD-specific sequences in relation to a reference gene, albumin. This paper discusses the optimization procedure and technical parameters of this multiplex assay.


Subject(s)
Heterozygote , Homozygote , Polymerase Chain Reaction/methods , Rh-Hr Blood-Group System/genetics , Albumins/genetics , Humans , Reproducibility of Results
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