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1.
Int Endod J ; 2024 Sep 10.
Article in English | MEDLINE | ID: mdl-39256997

ABSTRACT

AIM: The influence of hypercholesterolemia on the development of apical periodontitis (AP) is inconclusive. Recent studies revealed that cholesterol metabolite 27-hydoxycholesterol (27HC) can affect cellular responses to bacterial infections and oestrogen status and raloxifene may influence its action. Herein, we aimed to examine the impact of 27HC on production of inflammatory mediators by macrophages and the regulatory function of raloxifene. The contribution of 27HC to AP development and the therapeutic effect of raloxifene were evaluated in a rat model. METHODS: Murine macrophages J774 cells were used. The expression of inducible nitric oxide synthase (iNOS) was examined by Western blot. The concentrations of C-C motif chemokine ligand (CCL) 2 and 27HC were assessed by enzyme-linked immunosorbent assay. Colorimetric assay was used to evaluate cholesterol levels. Experimental AP was induced in ovariectomized (OVX) or un-operated rats receiving high-fat/high-cholesterol diet (HFHCD) or normal diet (ND). Micro-computed tomography and immunohistochemistry were employed to evaluate disease severity and the therapeutic effect of raloxifene. RESULTS: Cholesterol enhanced 27HC production in macrophages. 27HC induced iNOS and CCL2 synthesis by macrophages and estradiol suppressed the responses. In our animal model of AP, HFHCD plus OVX significantly augmented serum and lesion tissue levels of 27HC (p < .05 versus the ND group). Lesion size, infiltration of CD68+ cells, and iNOS+ monocytes were increased in parallel with 27HC accumulation. Raloxifene inhibited pro-inflammatory effects of 27HC on macrophages and suppressed AP progression in HFHCD/OVX rats (p < .05 versus the vehicle control group). CONCLUSIONS: Our results suggested that 27HC contributes to AP aggravation associated with hypercholesterolemia. Oestrogen deficiency may both enhance 27HC production and exacerbate its downstream action.

2.
Zhonghua Jie He He Hu Xi Za Zhi ; 45(12): 1209-1213, 2022 Dec 12.
Article in Chinese | MEDLINE | ID: mdl-36480852

ABSTRACT

Objective: To explore the effect of screening tuberculosis patients in the respiratory department of general hospitals, and to provide a basis for the development of patient screening strategy. Methods: Clinical information and sputum samples of inpatients in the respiratory department of a general hospital in Longhua District, Shenzhen from December 2018 to December 2020 were collected. Sputum samples were sent to the tuberculosis laboratory of the Shenzhen Longhua Center for Chronic Disease Control (designated tuberculosis diagnosis and treatment institution) for sputum smear, liquid culture and Gene-Xpert test. Results: A total of 407 sputum samples (23 cases of suspected tuberculosis by chest imaging and 384 by clinical manifestations) were collected from 3 724 hospitalized patients. A total of 88 patients with positive etiology were detected by the three methods, and the positive rate was 21.6% (88/407), among which 15 patients with suspected tuberculosis were detected by imaging reports, and the positive rate of etiology was 19.0% (73/384) in the reported patients without imaging reports. At least 1.96% (73/3 724) of the hospitalized patients were estimated to be tuberculosis positive during the study. Pneumonia (30.1%,22/73), cough (15.1%,11/73) and pulmonary infection (15.1%,11/73) were the main characteristics in the patients with positive pathogens. Conclusions: Screening for tuberculosis among inpatients in the respiratory department of general hospitals is an effective way to detect patients who were radiographically reported to have probable tuberculosis. It is of great significance to carry out active screening in key departments of general hospitals for tuberculosis detection and control.


Subject(s)
Tuberculosis , Humans , Tuberculosis/diagnosis
3.
Eur Rev Med Pharmacol Sci ; 26(23): 8660-8674, 2022 12.
Article in English | MEDLINE | ID: mdl-36524485

ABSTRACT

OBJECTIVE: This study aims to construct a brand-new ophthalmic disease screening task and establish a practically valuable ophthalmic disease screening model in the case of insufficient data. MATERIALS AND METHODS: The main methods are as follows: firstly, we mixed data from different sources (these data may come from different cameras, including different fundus diseases) to get a new dataset. Based on this dataset, we conducted subsequent experiments on fundus multi-disease screening. However, in the past public datasets, each dataset often only corresponded to the screening diagnosis of one disease. Secondly, we proposed a method to simulate the characteristics of different fundus cameras by using a method based on style transfer, and to augment the training data, so that the model could learn the features of ophthalmic diseases in a more comprehensive way. Finally, a robust disease screening model based on few-shot learning was constructed on the combined dataset, and compared with benchmark algorithms. RESULTS: We focused on the study of eye disease screening methods based on the metric-based few-shot learning model, data augmentation methods, and focus on key technologies such as data augmentation based on style transfer. Experiments have shown that our method can significantly improve the generalization ability of the disease screening model. CONCLUSIONS: By introducing few-shot learning theory and data augmentation based on style transfer into ophthalmic disease screening, the generalization ability of the model is greatly improved, and it has certain practical value.


Subject(s)
Algorithms , Learning , Technology
4.
Int Endod J ; 54(6): 902-915, 2021 Jun.
Article in English | MEDLINE | ID: mdl-33369764

ABSTRACT

AIM: To examine the role of palmitic acid in lipopolysaccharide (LPS)-stimulated chemotaxis of macrophages and the potential contribution of saturated fatty acid in signalling during the pathogenesis of apical periodontitis. METHODOLOGY: J774, a mouse macrophage cell line, was used in the experiments. After treatment with LPS, proteolytic maturation of sterol regulatory element-binding protein-1c (SREBP-1c) and expression of fatty acid synthase (FASN) were examined by Western analysis. Levels of palmitic acid were measured by reverse phase-high performance liquid chromatography-mass spectrometry. Knockdown of SREBP-1c and FASN was accomplished by small interfering RNA technology. Secretion of CC-chemokine ligand 2 (CCL2) and cellular chemotaxis were assessed by enzyme-linked immunosorbent assay and transwell migration assay, respectively. Sulfo-N-succinimidyl oleate (SSO) treatment was used to inhibit fatty acid signalling in vitro and also in a rat model of apical periodontitis. All data were first subjected to Levene's test. In vitro data were then analysed using ANOVA followed by Tukey's multiple comparison test. Data from animal experiments were analysed by independent t-tests. The significant level was set at 0.05. RESULTS: LPS stimulated proteolytic maturation of SREBP-1c and FASN expression in macrophages and significantly enhanced palmitic acid synthesis (P < 0.05). Knockdown of SREBP-1c attenuated LPS-enhanced FASN expression. Knockdown of FASN significantly suppressed LPS-enhanced palmitic acid synthesis (P < 0.05). LPS and exogenous palmitic acid significantly enhanced CCL2 secretion and macrophage chemotaxis (all P < 0.05). Inhibition of FASN expression significantly alleviated LPS-augmented CCL2 secretion (P < 0.05). SSO significantly suppressed CCL2 secretion and macrophage chemotaxis augmented by LPS and palmitic acid (all P < 0.05). In a rat model of induced apical periodontitis, SSO treatment significantly attenuated progression of apical periodontitis and macrophage recruitment (all P < 0.05). CONCLUSIONS: LPS/SREBP-1c/FASN/palmitic acid signalling contributed to tissue destruction caused by bacterial infection. Modulation of lipid metabolism and signalling may be helpful for the management of apical periodontitis.


Subject(s)
Lipopolysaccharides , Periapical Periodontitis , Animals , Fatty Acids , Macrophages , Mice , Rats , Sterol Regulatory Element Binding Protein 1
5.
Hong Kong Med J ; 26(2): 95-101, 2020 04.
Article in English | MEDLINE | ID: mdl-32245911

ABSTRACT

INTRODUCTION: To compare the intermediate-term outcomes and patient-reported outcomes of robot-assisted laparoscopic prostatectomy (RALP) and radical external beam radiotherapy (RT) in Chinese patients with localised prostate cancer. METHODS: This was a retrospective study of patients with localised prostate cancer diagnosed between 2010 and 2011 and treated with either RALP or RT. Baseline patient and disease characteristics, post-treatment complications, and latest disease status were retrospectively collected from hospital records. For assessment of patient-reported outcomes, the Chinese version of the Expanded Prostate Cancer Index Composite (EPIC) questionnaire was completed by the patients. RESULTS: Ninety three patients aged 58 to 84 years were recruited. Thirty patients were treated by RALP (32.3%), whereas 63 received RT (67.7%). The RALP group had significantly lower baseline prostate-specific antigen levels than the RT group (P<0.001). More patients who underwent RALP reported urinary incontinence (70.0% vs 3.2%, P<0.001), whereas more patients who underwent RT reported other voiding symptoms (87.3% vs 50.0%, P<0.001) and perirectal bleeding (36.5% vs 0%, P<0.001) during follow-up. Of the 85 patients who were still alive at the time of the study, 52 (61.2%) returned completed questionnaires. Patients who underwent RALP had poorer median (interquartile range) EPIC urinary summary scores than patients who underwent RT [81.5 (18.3) vs 88.9 (17.9), P=0.016]. Urinary function [75.9 (20.4) vs 93.6 (16.2), P<0.001] and incontinence [60.5 (31.8) vs 91.8 (14.5), P<0.001] were also significantly worse in the RALP group. The bowel and sexual domain scores were similar between the two groups. CONCLUSIONS: We found that RALP and RT were associated with different patterns of complications and patient-reported outcomes. Urinary incontinence was much more prevalent in the patients treated surgically. This may significantly affect patients' quality of life.


Subject(s)
Laparoscopy/adverse effects , Patient Reported Outcome Measures , Prostatectomy/adverse effects , Prostatic Neoplasms/radiotherapy , Prostatic Neoplasms/surgery , Aged , Aged, 80 and over , Hong Kong , Humans , Laparoscopy/methods , Male , Middle Aged , Prostate-Specific Antigen , Prostatectomy/methods , Quality of Life , Retrospective Studies , Robotics , Surveys and Questionnaires , Treatment Outcome , Urinary Incontinence/etiology
6.
Hong Kong Med J ; 25(5): 372-381, 2019 10.
Article in English | MEDLINE | ID: mdl-31619576

ABSTRACT

INTRODUCTION: This study was conducted to evaluate sexual function in adult survivors of childhood cancers and investigate possible relationships between sexual function and quality of life, as measured by general well-being, self-esteem, body image, and depressive symptoms. METHODS: This cross-sectional survey was performed in our centre from 14 August 2015 to 8 September 2017. Adult patients who had a history of childhood cancers, and who were disease-free for >3 years, were approached for the study during clinical follow-up. Clinical information was collected from medical records. Self-administered questionnaires regarding quality of life and sexual functioning were given to the patients and resulting data were analysed. RESULTS: Two hundred patients agreed to participate in the study. The overall response rate was 64.8%. Ninety-one (45.5%) patients were women, and the mean age was 25.4 ± 5.57 years. The overall sexual functioning score was 28.3 ± 20.09. Forty-eight (24.0%) patients reported at least one sexual problem. Among patients who reported no sexual problems, more had haematological cancers (P=0.009), fewer underwent surgery (P=0.004), fewer underwent surgery with external effects (P=0.032), and fewer were regular social drinkers (P=0.013); additionally, they had a higher mean Rosenberg self-esteem scale score (P=0.010), lower mean body image scale score (P=0.008), and lower mean Patient Health Questionnaire score (P=0.001). CONCLUSION: Aspects of life beyond disease condition and physical function should be considered in adult survivors of childhood cancers. Appropriate referral and intervention should be initiated for these patients when necessary.


Subject(s)
Cancer Survivors , Neoplasms/physiopathology , Neoplasms/psychology , Quality of Life , Self Concept , Sexual Dysfunction, Physiological/etiology , Adult , Alcohol Drinking , Body Image , Child , Cross-Sectional Studies , Depression , Female , Hong Kong , Humans , Linear Models , Male , Surveys and Questionnaires , Young Adult
7.
Malays Fam Physician ; 14(3): 18-27, 2019.
Article in English | MEDLINE | ID: mdl-32175037

ABSTRACT

BACKGROUND: Colorectal cancer (CRC) is the second most common cancer in Malaysia. Awareness of risk factors, symptoms and warning signs of CRC will help in early detection. This paper presents the level of CRC awareness among the urban population in Malaysia. METHOD: A cross-sectional study was conducted from November 2015 till December 2016 at three government clinics in the Klang Valley. The validated Bowel Cancer Awareness Measure questionnaire in both English and Malay was used. The mean knowledge scores for the warning signs and risk factors of CRC in different socio-demographic groups were compared using ANOVA in SPSS version 23. Statistical significance was set at p<0.05 and a 95% confidence level. RESULTS: Of the 426 respondents, 29.1% were unable to recall the warning signs and symptoms of CRC. Average recall was less than two warning signs and symptoms (mean 1.62, SD 1.33). The mean total knowledge score for CRC was 9.91 (SD 4.78), with a mean knowledge scores for warning signs and risk factors at 5.27 (SD 2.74) and 4.64 (SD 2.78), respectively. Respondents with a higher level of education were found to have higher level of knowledge regarding the warning signs of CRC. There was a significant positive association between knowledge score for warning signs and level of confidence in detecting warning signs. Regarding the total knowledge score for CRC, 3.3% of respondents scored zero. For warning signs and risk factors, 8.2% and 8.5% of respondents had zero knowledge scores, respectively. CONCLUSIONS: Generally, awareness of CRC is poor among the urban population of Klang Valley. Greater education and more confidence in detecting warning signs are significantly associated with better knowledge of warning signs. CRC awareness programs should be increased to improve awareness.

8.
Int Endod J ; 52(5): 676-688, 2019 May.
Article in English | MEDLINE | ID: mdl-30537112

ABSTRACT

AIM: To assess the connection between mitophagy and hypoxia-induced apoptosis in osteoblasts and whether simvastatin alleviates bone resorption in apical periodontitis through modulation of mitophagy-related apoptosis. METHODOLOGY: Hypoxia-induced generation of reactive oxygen species in mitochondria and changes in mitochondrial membrane potential were evaluated, respectively, by MitoSOX and JC-1 fluorescence dye signalling. Accumulation of mitophagy markers PTEN-induced putative kinase 1 (PINK1) and Parkin in mitochondria was examined by Western blotting and immunofluorescence microscopy. Osteoblast apoptosis was assessed by Western analysis of cleaved-poly (adenosine diphosphate ribose) polymerase (PARP). In a rat model of induced apical periodontitis, the therapeutic effect of simvastatin and its action on osteoblast mitophagy and apoptosis were examined. anova, Fisher's and Student's t-test were used for data analysis. RESULTS: Hypoxia-induced mitochondrial dysfunction and stimulated mitophagy in osteoblasts. Hypoxia also provoked apoptosis in osteoblasts and inhibition of mitophagy decreased hypoxia-augmented apoptotic activity. Simvastatin alleviated hypoxia-induced mitochondrial dysfunction, mitophagy and apoptosis. The protective action of simvastatin against apoptosis was related to its antimitophagy activity. Experiments in the rat model of induced apical periodontitis supported the laboratory findings. Simvastatin treatment mitigated periapical bone loss and reduced the activities of apoptosis and mitophagy in regional osteoblasts. CONCLUSIONS: The results suggest that modulation of osteoblast mitophagy may help diminish bone loss associated with inflammation and has potential as an auxiliary therapy for apical periodontitis.


Subject(s)
Bone Resorption , Periapical Periodontitis , Animals , Apoptosis , Humans , Mitophagy , Osteoblasts , Rats , Simvastatin
9.
Int Endod J ; 51 Suppl 2: e74-e86, 2018 Feb.
Article in English | MEDLINE | ID: mdl-28039864

ABSTRACT

AIM: To investigate the attenuating effect of sirtuin 6 (SIRT6) on hypoxia-induced production of chemokine (C-C motif) ligand 2 (CCL2) by osteoblasts and the relevance of this action on the pathogenesis of periapical lesions. METHODOLOGY: Sirtuin 6 was overexpressed in MC3T3-E1 murine osteoblasts by lentivirus-mediated gene transfer. The relationship between the antiglycolytic/antioxidative activities of SIRT6 and its effect on hypoxia-induced CCL2 production were examined. Pathogenetic relevance of the actions of SIRT6 was assessed in a rat model of induced apical periodontitis. The data were analysed statistically using Student's t-test or one-way analysis of variance (anova) and then a Tukey's multiple comparison test. RESULTS: In cultured murine osteoblasts, 24-h hypoxic treatment significantly enhanced the generation of reactive oxygen species (P = 0.003), expression of lactate dehydrogenase A (LDHA) and production of lactate (P = 0.007). A reciprocal effect between hypoxia-induced redox imbalance and hypoxia-enhanced glycolysis was noted which in turn augmented the secretion of CCL2. Through its antiglycolytic and antioxidative effects, SIRT6 blocked the vicious cycle to suppress CCL2 production. In normal periapical tissues of rats, strong expression of SIRT6 and low levels of LDHA and 8-OHdG (a marker of oxidative DNA damage) were found in osteoblasts. In induced apical periodontitis, osteoblastic expression of SIRT6 was significantly suppressed (P = 0.001) which was associated with significantly elevated levels of LDHA (P = 0.003) and 8-OHdG (P = 0.004) and significantly enhanced recruitment of macrophages (P = 0.004). CONCLUSIONS: Sirtuin 6 has a therapeutic effect on periapical lesions through suppression of CCL2 synthesis. The anti-inflammatory action of SIRT6 is closely related to its regulatory activities in cellular metabolism and redox homoeostasis.


Subject(s)
Chemokine CCL2/metabolism , Hypoxia/metabolism , Osteoblasts/metabolism , Periapical Periodontitis/metabolism , Sirtuins/metabolism , Animals , Blotting, Western , Cells, Cultured , Lactic Acid/metabolism , Mice , Mitochondria/metabolism , Reactive Oxygen Species/metabolism
10.
Scand J Immunol ; 79(3): 173-80, 2014 Mar.
Article in English | MEDLINE | ID: mdl-24383579

ABSTRACT

The potential use of lymphoid chemokines to generate a dendritic cell (DC) cancer vaccine is not yet clear. We investigated the effect of lymphoid chemokines on DC function and on the production of effective cytotoxic T lymphocytes (CTLs) for application of cancer vaccine using monocyte-derived mature DCs (mDCs) prestimulated with lymphoid chemokines. mDCs exposed to a secondary lymphoid organ chemokine (SLC/CCL21) dramatically induced CTL response by increasing cytolytic activity without any significant alterations on expression of cell surface markers (e.g. CD80, CD83, CD86 and CCR7) or on the production of cytokines (e.g. IL-12p70, IL-10 and IL-23). Interestingly, mDCs prestimulated with CCL21 showed higher levels of CXCL10 (IP-10) production, but not the production of CCL22, compared with untreated mDCs. IP-10 treatment during CTL generation with DCs dramatically enhanced tumour-specific CTL response compared with untreated CTLs, and these enhanced CTL-inducing functions of CCL21-treated DCs were inhibited by anti-IP-10 treatment. Taken together, our data suggested an important role of the lymphoid-endothelium-associated chemokine, CCL21, on DCs in the induction of CTL responses.


Subject(s)
Chemokine CCL21/metabolism , Chemokine CXCL10/immunology , Dendritic Cells/immunology , Dendritic Cells/metabolism , T-Lymphocytes, Cytotoxic/immunology , Antigens, CD/metabolism , B7-1 Antigen/metabolism , B7-2 Antigen/metabolism , Cancer Vaccines/immunology , Cells, Cultured , Chemokine CCL22/biosynthesis , Chemokine CXCL10/biosynthesis , HLA-A2 Antigen/metabolism , Humans , Immunoglobulins/metabolism , Interferon-gamma/biosynthesis , Interleukin-10/metabolism , Interleukin-12/metabolism , Interleukin-23/metabolism , Lymphocyte Activation/immunology , Membrane Glycoproteins/metabolism , Receptors, CCR7/metabolism , CD83 Antigen
11.
Int J Cosmet Sci ; 35(5): 484-90, 2013 Oct.
Article in English | MEDLINE | ID: mdl-23714012

ABSTRACT

OBJECTIVES: The aim of this study was to investigate the whitening and antioxidant activities of essential oils from Cryptomeria japonica by determining their tyrosinase inhibition, 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging and superoxide dismutase (SOD)-like activities. METHODS: Essential oils of C. japonica leaves were extracted with distilled water, and after condensation of volatile constituents, the condensates were extracted with ethyl acetate. Crude essential oils of C. japonica were divided into six fractions by thin layer chromatography and open column chromatography, and their chemical analysis was performed by GC/MS. Major compounds of fractions were composed of kaurene, bornyl acetate, nezukol, (-)-4-terpineol, δ-cadinene, α-terpineol, γ-eudesmol, α-eudesmol and elemol. RESULTS: For tyrosinase inhibitory activity using two substrates, l-tyrosine and 3,4-dihydroxyphenylalanine (l-DOPA), kaurene, bornyl acetate and nezukol were highly effective. In antioxidant activity, (-)-4-terpinenol and δ-cadinene showed high DPPH radical scavenging activity, and bornyl acetate and nezukol indicated extremely high SOD-like activity. CONCLUSION: Therefore, bornyl acetate and nezukol fractionated from C. japonica essential oil, which showed highly active whitening and antioxidant activities, have potential applications in cosmeceutical materials.


Subject(s)
Antioxidants/isolation & purification , Camphanes/isolation & purification , Cryptomeria/chemistry , Enzyme Inhibitors/isolation & purification , Plant Oils/chemistry , Sesquiterpenes/isolation & purification , Antioxidants/metabolism , Antioxidants/pharmacology , Biphenyl Compounds/antagonists & inhibitors , Biphenyl Compounds/metabolism , Camphanes/metabolism , Camphanes/pharmacology , Enzyme Inhibitors/metabolism , Enzyme Inhibitors/pharmacology , Gas Chromatography-Mass Spectrometry , Monophenol Monooxygenase/antagonists & inhibitors , Monophenol Monooxygenase/metabolism , Picrates/antagonists & inhibitors , Picrates/metabolism , Plant Leaves/chemistry , Sesquiterpenes/metabolism , Sesquiterpenes/pharmacology , Superoxide Dismutase/antagonists & inhibitors , Superoxide Dismutase/metabolism
12.
IEEE Trans Nanobioscience ; 12(2): 65-8, 2013 Jun.
Article in English | MEDLINE | ID: mdl-23392387

ABSTRACT

The low limit of detection (LLD) plays an important role in biomolecular assays, especially for early-stage assays. Biomolecular detections usually involve the use of two main elements: a reagent and an analyzer, which both greatly contribute to the LLD. In this work, the relationships among the LLD and reagent-related factors are investigated. The to-be-detected biomolecule is c-reactive protein (CRP) as an example. The assay method is immunomagnetic reduction (IMR). The components of reagent are Fe(3)O(4) magnetic nanoparticles bio-functionalized with antibodies against CRP, dispersed in pH-7.4 phosphate buffered saline solution. Several key factors of the reagent, such as particle concentration, volume ratio of reagent to sample, and particle size, are manipulated to optimize the LLD of detecting CRP.


Subject(s)
C-Reactive Protein/analysis , Indicators and Reagents/chemistry , Limit of Detection , Magnetite Nanoparticles/chemistry , Antibodies/chemistry , Antibodies/immunology , C-Reactive Protein/immunology , Immunoassay , Magnetic Phenomena , Particle Size , Sodium Chloride/chemistry
13.
J Virol Methods ; 181(1): 68-72, 2012 Apr.
Article in English | MEDLINE | ID: mdl-22335935

ABSTRACT

Nervous necrosis virus (NNV) is the cause of viral nervous disease, which is a serious constraint on production for grouper aquaculture. Real-time PCR is commonly used to detect and quantify NNV, has the disadvantages of being expensive and technically demanding. In this study, an immunomagnetic reduction (IMR) assay was developed as a rapid and cost-effective alternative to real-time PCR. This method used magnetic nanoparticles conjugated with antibodies specific for viral surface antigens to detect NNV in grouper tissue samples. The association of NNV with the antibody-conjugated magnetic particles resulted in a reduction in magnetic signal, which was strongly correlated with the concentration of NNV, as determined by real-time PCR. Grouper larvae were prepared for testing using a viral extraction buffer which provided a rapid, 15-min method of extracting viral antigens and had an extraction efficiency of higher than 80%. In addition, this study proposes using magnetic nanoparticles as labeling markers and as an assaying reagent for NNV. The magnetic nanoparticles are functionalized with antibodies against the viral surface of NNV and are able to associate specifically with NNV. The reduction of the magnetic signals comes from the association between magnetic particles and NNV, and relates to the concentration of NNV. The results show that the detected concentrations of NNV are highly correlated to those detected by real-time PCR.


Subject(s)
Bass/virology , Fish Diseases/virology , Immunomagnetic Separation/methods , Nodaviridae/isolation & purification , Viral Load/methods , Animals , Antibodies, Viral , Rabbits , Sensitivity and Specificity
14.
Rev Sci Instrum ; 82(8): 084301, 2011 Aug.
Article in English | MEDLINE | ID: mdl-21895259

ABSTRACT

Although magnetic nanoparticles (MNPs) have been widely applied to animals in biomedicine, MNPs within animals should be examined in real time, in vivo, and without bio-damaged possibility to evaluate whether the bio-function of MNPs is valid or to further controls the biomedicinal process because of accompanying complex problems such as MNPs distribution and MNPs biodegradation. The non-invasive and high-sensitivity scanning detection of MNPs in animals using ac susceptometry based on a high-T(c) superconducting quantum interference device (SQUID) is presented. The non-invasive results and biopsy results show good agreement, and two gold-standard biomedicine methods, Prussian blue stain and inductively coupled plasma, prove the magnetic results. This confirms that the future clinical diagnosis of bio-functional MNPs could be operated by using scanning SQUID biosusceptometry as conveniently as an ultrasonic probe.


Subject(s)
Magnetometry/instrumentation , Magnets/analysis , Nanoparticles/analysis , Animals , Hot Temperature , Liver/chemistry , Liver/cytology , Male , Rats
15.
IEEE Trans Biomed Eng ; 58(10): 2719-24, 2011 Oct.
Article in English | MEDLINE | ID: mdl-21041154

ABSTRACT

Magnetic nanoparticles have been widely applied to biomagnetism, such as drug deliver, magnetic labeling, and contrast agent for in vivo image, etc. To localize the distribution of these magnetic particles in living organism is the first important issue to confirm the effects of magnetic nanoparticles and also evaluate the possible untoward effects. In this study, a scanning high T(c) rf-SQUID superconducting quantum interference devices (SQUIDs) biosusceptometry, composed of static SQUID unit and scanning coil sets, is developed for biomedicine study with the advantages of easy operation and unshielded environment. The characteristics tests showed that the system had the low noise of 8 pT/Hz at 400 Hz and the high sensitivity with the minimum detectable magnetization around 4.5 × 10(-3) EMU at distance of 13 mm. A magnetic nanoparticle detection test, performed by ex vivo scanning of the magnetic fluids filled capillary under swine skin for simulation of blood vessels in living bodies, confirmed that the system is feasible for dynamic tracking of magnetic nanoparticles. Based on this result, we performed further studies in rats to clarify the dynamic distribution of magnetic nanoparticle in living organism for the pharmacokinetics analysis like drug delivers, and propose the possible physiological metabolism of intravenous magnetic nanoparticles.


Subject(s)
Magnetite Nanoparticles/chemistry , Molecular Imaging/methods , Animals , Dextrans/chemistry , Male , Molecular Imaging/instrumentation , Rats , Rats, Wistar , Swine , Tissue Distribution
16.
Oral Microbiol Immunol ; 22(1): 24-9, 2007 Feb.
Article in English | MEDLINE | ID: mdl-17241167

ABSTRACT

This study aimed to elucidate the modulation by nitric oxide (NO) of the apoptosis of macrophages and osteoblasts, the essential cellular components in the development of periapical lesions. Lipopolysaccharide (LPS) induced prominent nitrite synthesis in J774 mouse macrophage cell lines. Exposure to LPS induced obvious apoptosis in J774 cells, whereas transient transfection with murine inducible nitric oxide synthase (iNOS), small interfering RNA (siRNA) diminished this effect. Tumor necrosis factor-alpha (TNF-alpha) and S-nitroso-N-acetyl-DL-penicillamine (SNAP) (a NO donor) triggered apoptosis in UMR-106 rat osteoblastic cell lines and a synergistic effect was noted when TNF-alpha and SNAP were added to the medium together. Administration of siRNAs for c-Fos and c-Jun: components of activator protein-1 (AP-1) and transforming growth factor-beta1 attenuated the combined effect markedly. Terminal deoxynucleotidyl transferase-mediated nick end-labeling (TUNEL) stain in a rat model of induced periapical lesion showed positive apoptotic signals in macrophages and osteoblasts. Administration of N(G)-monomethyl-l-arginine markedly diminished the extent of bone loss and the amounts of apoptotic macrophages and osteoblasts. In conclusion, NO mediates LPS-stimulated apoptosis of macrophages. It also induces osteoblast apoptosis and augments the pro-apoptotic effect of cytokines. Inhibition of NO synthesis in vivo attenuates apoptosis and the size of periapical lesions. Taken together, these results suggest that NO may promote the progression of periapical lesion by inducing the apoptosis of macrophages and osteoblasts.


Subject(s)
Apoptosis/drug effects , Free Radical Scavengers/pharmacology , Macrophages/drug effects , Nitric Oxide/pharmacology , Osteoblasts/drug effects , Periapical Diseases/physiopathology , Animals , Cell Line , Cells, Cultured , Disease Models, Animal , Disease Progression , Drug Synergism , Enzyme Inhibitors/pharmacology , Lipopolysaccharides/pharmacology , Mice , Nitric Oxide Donors/pharmacology , Nitric Oxide Synthase Type II/pharmacology , Nitrites/metabolism , Proto-Oncogene Proteins c-fos/pharmacology , Proto-Oncogene Proteins c-jun/pharmacology , RNA, Small Interfering/pharmacology , Rats , Rats, Wistar , S-Nitroso-N-Acetylpenicillamine/pharmacology , omega-N-Methylarginine/pharmacology
17.
Singapore Med J ; 47(6): 518-24, 2006 Jun.
Article in English | MEDLINE | ID: mdl-16752021

ABSTRACT

INTRODUCTION: This study aims to study whether knowledge that upper respiratory tract infection (URTI) resolves on its own is associated with more appropriate antibiotic cognition and treatment-seeking behaviour in adult patients seeking consultation for upper respiratory tract symptoms in all nine polyclinics of the National Healthcare Group in Singapore. METHODS: A prospective study of 595 adult patients who attended for URTI symptoms of less than seven days duration was performed. We collected data using an interviewer-administered structured questionnaire eliciting the participant's personal and demographical data, his knowledge about URTI, past experience with URTI and treatment-seeking behaviour for this current episode of URTI. These variables were then regressed against the variable "URTI resolves on its own", adjusting for "antibiotics relieve URTI faster", "antibiotic used unnecessarily for URTI", "recovery faster with antibiotics" for antibiotic cognition; and "number of days with URTI", "first line of action: self-medicate", "reason for attendance: felt unwell", "reason for attendance: get well faster" and "used prescribed medication before current visit" for health-seeking behaviour. RESULTS: More than one-third of patients believed that URTI resolved on its own. Subjects who believed that URTI resolved on its own were not significantly different in terms of gender, ethnic group, educational status, age, knowledge of germs as causal, and number of days sick before attendance. However, such patients were 1.68 times (confidence interval [CI] 1.17, 2.41) more likely to agree that, nowadays, antibiotics are used unnecessarily for "flu", and 2.07 times (CI 1.32, 3.24) more likely to self-medicate. They were 0.51 (CI 0.35, 0.76) times more likely to be dependant on prescribed medication. CONCLUSION: Knowledge that URTI resolves on its own is associated with more appropriate antibiotic cognition and health-seeking behaviour.


Subject(s)
Anti-Bacterial Agents , Health Education , Health Knowledge, Attitudes, Practice , Patient Acceptance of Health Care , Respiratory Tract Infections/prevention & control , Adult , Aged , Aged, 80 and over , Cognition , Female , Humans , Interviews as Topic , Male , Middle Aged , Prospective Studies , Respiratory Tract Infections/drug therapy , Respiratory Tract Infections/psychology , Self Medication , Singapore , Surveys and Questionnaires
18.
Neurology ; 62(11): 1999-2004, 2004 Jun 08.
Article in English | MEDLINE | ID: mdl-15184604

ABSTRACT

OBJECTIVE: To investigate the prevalence of Parkinson disease (PD) in Singapore and compare the rates between Singaporean Chinese, Malays, and Indians. METHODS: A three-phase community-based survey among a disproportionate random sample of 15,000 individuals (9,000 Chinese, 3,000 Malays, 3,000 Indians) aged 50 years and above who live in central Singapore was conducted. In phase 1, trained interviewers conducted a door-to-door survey using a validated 10-question questionnaire. In phase 2, medical specialists examined participants who screened positive to any of the questions. Participants suspected to have PD had their diagnosis confirmed in phase 3 by a movement disorders specialist. RESULTS: The participation rate was 67% among 22,279 eligible individuals. Forty-six participants with PD were identified of which 16 were newly diagnosed cases. The prevalence rate of PD for those aged 50 and above in Singapore was 0.30% (95% CI: 0.22 to 0.41), age-adjusted to US 1970 census. The prevalence rates increased significantly with age. The age-adjusted prevalence rates among Chinese (0.33%, 95% CI: 0.22 to 0.48), Malays (0.29%, 95% CI: 0.13 to 0.67), and Indians (0.28%, 95% CI: 0.12 to 0.67) were the same (p = 1.0). CONCLUSIONS: The prevalence of PD in Singapore was comparable to that of Western countries. Race-specific rates were also similar to previously reported rates and similar among the three races. Environmental factors may be more important than racially determined genetic factors in the development of PD.


Subject(s)
Ethnicity/genetics , Parkinson Disease/ethnology , Aged , Aged, 80 and over , China/ethnology , Female , Health Surveys , Humans , India/ethnology , Malaysia/ethnology , Male , Middle Aged , Parkinson Disease/epidemiology , Prevalence , Research Design , Sampling Studies , Singapore/epidemiology , Surveys and Questionnaires
19.
Singapore Med J ; 45(4): 154-60, 2004 Apr.
Article in English | MEDLINE | ID: mdl-15094983

ABSTRACT

INTRODUCTION: Ethnic differences exist in patients with diabetes mellitus. Not much is known about such differences in Asian populations. The aim of the study was to determine ethnic differences among Chinese, Malay and Indian patients with type 2 diabetes mellitus in Singapore. METHODS: The study design was cross-sectional, involving 967 patients who were attending follow-up care for type 2 diabetes mellitus at a primary care clinic. Data collection was by patient interview, examination, and from case records. Blood and urine samples were collected for analysis of indicators of diabetic control and albuminuria. RESULTS: Malays had the highest mean body mass index (BMI) after controlling for age, gender, duration of diabetes and exercise status. Adjusted mean BMI for Malays was 27.4kg per square metres, Indians 25.7kg per square metres, Chinese 24.9kg per square metres, with the p value being less than 0.01. HbA1c levels were highest among Indians after controlling for age, duration of diabetes, body mass index and treatment. Adjusted mean HbA1c for Indians was 8.3 percent, Malays 8.0 percent, and Chinese 7.7 percent, with the p value being less than 0.01. Compared with Chinese, Indians were more likely to have a positive family history of diabetes (prevalence rate ratio (PRR) of 1.3, 95 percent confidence interval (CI) of 1.0 to 1.7), but were less likely to have associated hypertension (PRR of 0.7, 95 percent CI of 0.5 to 1.0) and microalbuminuria and macroalbuminuria (PRR of 0.6, 95 percent CI of 0.4 to 1.0). CONCLUSION: Ethnic differences exist with regard to BMI, diabetic control as reflected by HbA1c levels, family history of diabetes, presence of associated hypertension, and severity of albuminuria. Indians, while having poorer control of diabetes, are less prone to hypertension and renal complications than Chinese.


Subject(s)
Diabetes Mellitus, Type 2/diagnosis , Diabetes Mellitus, Type 2/ethnology , Ethnicity/statistics & numerical data , Aged , Asian People/statistics & numerical data , Body Mass Index , Cross-Sectional Studies , Diabetes Mellitus, Type 2/drug therapy , Female , Glucose Tolerance Test , Humans , India/ethnology , Life Style , Malaysia/ethnology , Male , Middle Aged , Prevalence , Probability , Prognosis , Risk Assessment , Severity of Illness Index , Singapore/epidemiology
20.
QJM ; 96(10): 747-54, 2003 Oct.
Article in English | MEDLINE | ID: mdl-14500861

ABSTRACT

BACKGROUND: Use of complementary and alternative medicines (CAM) by asthmatic patients is increasing. Data on the prevalence of CAM use in asthma are limited, and the motivation for patients to seek CAM therapy is uncertain. AIM: To determine the prevalence and pattern of use of complementary therapies in adults treated for asthma in primary care in Singapore, and the demographic and clinical factors associated with their use. DESIGN: Cross-sectional study. SETTING: Five primary care clinics in Singapore. METHODS: Adult patients with asthma (n = 802) received a structured questionnaire interview and clinical assessment that included demographic and clinical variables (clinical status, patient's knowledge, self-care and healthcare-seeking behaviour, and spirometric measurements) and detailed information on CAM use in the past one year. RESULTS: CAM use in the past year was reported by 27.2%, including animal food products (12.3%), herbs (10.3%), herbal-based proprietary medicines (3.2%), and acupuncture or reflexology (1%). The use of CAM was significantly associated with Chinese ethnicity, longer disease duration, moderate and severe persistent asthma, FEV(1)/FVC < 80%, lack of positive response to treatment in the past year, higher patient knowledge score, and multiple sources of care providers. DISCUSSION: The use of CAM is highly prevalent in Asian patients treated for asthma in primary care, and is associated with cultural and clinical factors reflecting a need to improve care.


Subject(s)
Asthma/therapy , Complementary Therapies/statistics & numerical data , Patient Acceptance of Health Care/statistics & numerical data , Adult , Attitude to Health , Complementary Therapies/standards , Cross-Sectional Studies , Female , Health Services Accessibility , Herbal Medicine , Humans , Male , Middle Aged , Primary Health Care , Singapore , Surveys and Questionnaires
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