1.Nitroglycerin reduces augmentation index and central blood pressure independent of effects on cardiac preload
Baomin LIU ; Xiaolin NIU ; Benyu JIANG ; Mike SADDON ; Karen MCNEIL ; Philip CHOWIENCZYK
Journal of Pharmaceutical Analysis 2009;21(2):114-119
Objective To determine whether reduction In central pressure augmentation and central systolic blood pressure by nitroglycerine (NTG) results from effects on pre-lead or is due to arterial dilation. Methods We compared effects of NTG with these of lower body negative pressure (LBNP). Hemodyunmic measurements were made at rest, during LBNP (10, 20 and 30 mmHg, each for 15 min) and after NTG (10, 30 and 100μg/min, each dose for 15 min) in ten healthy volunteers. Cardiac pre-lead, stroke volume and cardiac output were assessed by echacardiography. Central pressure an mnentation and central systolic pressure were obtained by radial tonometry using a transfer function. Results LBNP (20 mmHg) and NTG (30μg/min) reduced pre-lead (as measured by the peak velocity of the S wave in the superior vena eava) to a similar degree [by (26. 8 ± 3.8) % and (23.9 ± 3. 4) %, respectively]. Compared to LBNP, NTG reduced systemic vascular resistance [by (32. 9 ± 7.5) %, p< 0. 01], decreased peripheral and central pressure augmentation [by (20. 8 ± 3. 4)% units and (12. 9±2. 9)% units, respectively, each P< 0. 01]. Conclusion These results suggest that a reduction in pre-load does not explain reduction in pressure augmentation and central systolic blood pressure by NTG and that these effects are mediated through arterial dilation.
2.Malaysian Parents’ Feedback On Three Proxy-Rated Assessments Used In Pediatric Rehabilitation
Farahiyah Wan Yunus ; Michelle Bissett ; Stefania Penkala ; Masne Kadar ; Karen Liu
Malaysian Journal of Public Health Medicine 2018;18(1):64-69
Assessing a child’s functional abilities and limitations can provide useful information for occupational therapists to develop individualised intervention plans. Usually paediatric assessments require parents to rate their child on different domains of health and functional performance. To do so, parents need to be able to understand the assessment content and instructions to rate their child accurately. The primary purpose of this study was to examine if parents in Malaysia understood the content and instructions of three assessments: the Sensory Profile Caregiver Questionnaire (SP), the Sensory Processing Measure Home Form (SPM) and the Behaviour Rating Inventory of Executive Function Parent Form (BRIEF). The secondary purpose was to examine perceptions about the clarity and relevancy of each of the items in each assessment. Thirty parents, recruited using convenience sampling, completed a survey about the assessments. In general, the parents indicated no problems or only minor problems in understanding the content and instructions of all three assessments. The parents also provided comments to improve the clarity of the assessment items. Comments were primarily related to the terms or jargon language used. Elaborations of the terms or jargon were later provided based on the parents’ comments. All three assessments were identified as relevant to be used in the Malaysian population. The results suggest that all three assessments can be used by parents and are suitable to be implemented by occupational therapists working with children in Malaysia.
Parent-rated assessments
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Malaysian children
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Face validity
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Cross-cultural relevancy
3.Topological Alterations of the Intrinsic Brain Network in Patients with Functional Dyspepsia.
Jiaofen NAN ; Li ZHANG ; Fubao ZHU ; Xiaorui TIAN ; Qian ZHENG ; Karen M VON DENEEN ; Jixin LIU ; Ming ZHANG
Journal of Neurogastroenterology and Motility 2016;22(1):118-128
BACKGROUND/AIMS: Previous studies reported that integrated information in the brain ultimately determines the subjective experience of patients with chronic pain, but how the information is integrated in the brain connectome of functional dyspepsia (FD) patients remains largely unclear. The study aimed to quantify the topological changes of the brain network in FD patients. METHODS: Small-world properties, network efficiency and nodal centrality were utilized to measure the changes in topological architecture in 25 FD patients and 25 healthy controls based on functional magnetic resonance imaging. Pearson's correlation assessed the relationship of each topological property with clinical symptoms. RESULTS: FD patients showed an increase of clustering coefficients and local efficiency relative to controls from the perspective of a whole network as well as elevated nodal centrality in the right orbital part of the inferior frontal gyrus, left anterior cingulate gyrus and left hippocampus, and decreased nodal centrality in the right posterior cingulate gyrus, left cuneus, right putamen, left middle occipital gyrus and right inferior occipital gyrus. Moreover, the centrality in the anterior cingulate gyrus was significantly associated with symptom severity and duration in FD patients. Nevertheless, the inclusion of anxiety and depression scores as covariates erased the group differences in nodal centralities in the orbital part of the inferior frontal gyrus and hippocampus. CONCLUSIONS: The results suggest topological disruption of the functional brain networks in FD patients, presumably in response to disturbances of sensory information integrated with emotion, memory, pain modulation, and selective attention in patients.
Anxiety
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Brain*
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Chronic Pain
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Connectome
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Depression
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Dyspepsia*
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Gyrus Cinguli
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Hippocampus
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Humans
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Magnetic Resonance Imaging
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Memory
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Orbit
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Putamen
4.Determination of the ADAMTS13 antigen and its activity in TTP patients and carriers.
Fang LIU ; Hendrik B FEYS ; Ning-zheng DONG ; Xia BAI ; Karen VANHOORELBEKE ; Hans DECKMYN ; Chang-geng RUAN
Chinese Journal of Hematology 2006;27(3):154-157
OBJECTIVETo investigate the antigen levels and activity of von Willebrand factor cleaving protease ADAMTS13 in thrombotic thrombocytopenic purpura (TTP) patients and carriers.
METHODS28 samples from 13 TTP patients and 10 samples from the carriers were examined. The activity of ADAMTS13 was measured by residue collagen binding assay, and antigen by a newly developed sandwich ELISA.
RESULTSThe mean ADAMTS13 level in Chinese normal controls (CN) was (600.93 +/- 145.36) mU/ml (n = 26) comparable to the level (1000 mU/ml) in pooled normal Caucasian plasma, and the activity was (74.79 +/- 11.81)%. Both the antigen level and activity of ADAMTS13 in congenital TTP patients either before plasma exchange (pre-PE) or interval relapse were quite lower than those in normal control, but were increased after PE (post-PE). The antigen was (331.40 +/- 109.85) mU/ml (P < 0.01, n = 10), and activity was (66.79 +/- 12.82)% (P > 0.05). The ADAMTS13 levels pre-PE in idiopathic TTP was (98.7 +/- 82.08) mU/ml (n = 11, P < 0.01), and that post-PE was up to (449.4 +/- 232.33) mU/ml (P < 0.01, n = 10). The activity of ADAMTS13 in patients pre-PE and post-PE were (22.23 +/- 19.07)% (P < 0.01) and (60.92 +/- 22.33)% (P > 0.05) respectively. In a secondary TTP patient the ADAMTS13 antigen was much higher than that in CN, and the activity was 6.00%.
CONCLUSIONThe antigen and activity of ADAMTS13 in most TTP patients pre-PE are deficient, and these two indices in most TTP patients are paralleled. The reason for ADAMTS13 deficiency is congenital shortage or clearance by immune system, but it is unknown that why in some patients the ADAMTS13 antigen is extremely high but its activity is quite low.
ADAM Proteins ; blood ; immunology ; ADAMTS13 Protein ; Adult ; Female ; Humans ; Male ; Purpura, Thrombotic Thrombocytopenic ; blood ; immunology
5.Two sets of acupoint combination of similar functions engage shared neural representation: a functional magnetic resonance imaging study.
Ling ZHAO ; Wei QIN ; Ji-xin LIU ; Li FANG ; Ming-hao DONG ; Fu-wen ZHANG ; Cui JIANG ; Jin-bo SUN ; Karen M von DENEEN ; Fan-rong LIANG
Chinese journal of integrative medicine 2014;20(3):184-193
OBJECTIVETo investigate whether the neural representations underlying alternating two acupoint combinations (ACs) are the same or not.
METHODSIn this functional magnetic resonance imaging study, two sets of analgesia ACs were utilized, including Waiguan (TE5) and Qiuxu (GB40) for Group A, and Neiguan (PC6) and Taichong (LR3) for Group B, which are the most commonly adopted in clinical treatment. Each group had 20 healthy subjects. An experimental design was proposed, which consisted of a pre-needling resting phase, a needling phase and a post-needling resting phase. This paradigm optimally mimics the clinical protocol as well as focuses on both the stimulation and the resting periods. The results were subjected to general linear model analysis, conjunction analysis and the functional connectivity analysis.
RESULTSThe rostral anterior cingulated cortex was engaged in the initiative period of the acupuncture effect in both groups, and it was chosen as the seed region for the functional connectivity analysis for the following resting period. The results showed that several shared brain regions were involved in both groups, in particular the insula, amygdala and hypothalamus. Moreover, significant differences were located at the posterior cingulated cortex as revealed by a two sample -test (P<0.05, corrected). Other regions showed no significant differences. This finding was further supported by the spatial correlation analysis that the two groups were significantly correlated (r =0.51, P<0.01).
CONCLUSIONThis preliminary research helps us understand the neurophysiological mechanisms of acupuncture when following clinical guidelines on ACs, as well as provides an important opportunity to develop better treatment strategies for reducing, or even preventing pain.
Acupuncture Points ; Acupuncture Therapy ; Female ; Gyrus Cinguli ; physiology ; Humans ; Magnetic Resonance Imaging ; Male ; Nerve Net ; physiology ; Nervous System Physiological Phenomena ; Psychophysics ; Rest ; Signal Processing, Computer-Assisted ; Statistics as Topic ; Young Adult
6.Expression and function of MCP-1 and its receptor in wAMD model mouse
Quan ZHOU ; Lin XIAO ; Jing-Mei XU ; Bing XU ; Karen WU ; Jing LIU ; Yan LU ; Li-Qun CHU
Chinese Journal of Clinical and Experimental Pathology 2018;34(1):32-36
Purpose To detect the expression and the function of MCP-1 and its receptor CCR2 in wet agerelated macular degenerative (wAMD) model mouse retina. Methods C57BL/6J mouse were enrolled into the study. Model mouse of wAMD was induced with laser. Frozen sections were prepared for histopathological tests. Immunofluorescence study for MCP-1 and CCR2 was carried out. Co-expression study for CCR2/ CDllb or CCR2/CD68 was carried out. Total protein and total mRNA from the eyes of both wAMD and wild type mouse were extracted. The expression of mRNA and protein of MCP-1 and CCR2 in the eyes were determined by reverse transcription-poly-merase chain reaction (RT-PCR) and Western blots test, respectively. Results In wild type mouse, both MCP-1 and its receptor CCR2 were not detected in the retina. However in wAMD mouse, an obvious up-regulated MCP-1 and CCR2 expression was seen in the retinal pigment epithelium (RPE) cells accompanied with the increased expression of their mRNA and protein. The co-expression study showed that CCR2 co-ex-pressed with CDllb, but not with CD68. Conclusion MCP-1 and its receptor CCR2 may play a role in the wAMD through stimulation of microglia.
7.Variation of sexual dimorphism and asymmetry in disease expression of inflammatory arthritis among laboratory mouse models with different genomic backgrounds
Wei DONG ; Cheng TIAN ; Z. Galvin LI ; David BRAND ; Yanhong CAO ; Xiaoyun LIU ; Jiamin MA ; Andy CHAI ; Linda K. MYERS ; Jian YAN ; Karen HASTY ; John STUART ; Yan JIAO ; Weikuan GU ; Xiaojun CAI
Laboratory Animal Research 2023;39(4):402-410
Sex difference has shown in the arthritis diseases in human population and animal models. We investigate how the sex and symmetry vary among mouse models with different genomic backgrounds. Disease data of sex and limbs accumulated in the past more than two decades from four unique populations of murine arthritis models were analyzed. They are (1) interleukin-1 receptor antagonist (IL-1ra) deficient mice under Balb/c background (Balb/c KO); (2) Mice with collagen II induced arthritis under DBA/1 background; (3) Mice with collagen II induced arthritis under C57BL/6 (B6) background and (4) A F2 generation population created by Balb/c KO X DBA/1 KO.Our data shows that there is a great variation in sexual dimorphism for arthritis incidence and severity of arthritis in mice harboring specific genetic modifications. For a F2 population, the incidence of arthritis was 57.1% in female mice and 75.6% in male mice. There was a difference in severity related to sex in two populations: B6.DR1/ B6.DR4 (P < 0.001) and F2 (P = 0.023) There was no difference Balb/c parental strain or in collagen-induced arthritis (CIA) in DBA/1 mice. Among these populations, the right hindlimbs are significantly higher than the scores for the left hindlimbs in males (P < 0.05). However, when examining disease expression using the collagen induced arthritis model with DBA/1 mice, sex-dimorphism did not reach statistical significance, while left hindlimbs showed a tendency toward greater disease expression over the right. Sexual dimorphism in disease expression in mouse models is strain and genomic background dependent. It sets an alarm that potential variation in sexual dimorphism among different racial and ethnic groups in human populations may exist. It is important to not only include both sexes and but also pay attention to possible variations caused by disease expression and response to treatment in all the studies of arthritis in animal models and human populations.
8.Advisory Panel Review on the Feasibility of Three Intervention Programmes for Children with Autism Spectrum Disorder
Farahiyah Wan Yunus ; Michelle Bissett ; Stefania Penkala ; Muhammad Hibatullah Romli ; Karen P.Y Liu
Malaysian Journal of Medicine and Health Sciences 2020;16(No.2):43-51
Introduction: The prevalence of children with autism spectrum disorder is increasing each year. Intervention programmes towards improving the occupational needs such as daily activities of these children are limited. This study aimed to collect opinions from advisory panel for the content validation of the three developed intervention programmes to be implemented among children with autism spectrum disorder aged between 6 to 12 years. The intervention programmes are; i) self-regulated learning, ii) sensory integration intervention and iii) activity-based intervention. Methods: A cross-sectional study was conducted. Twenty occupational therapists with more than three years’ experience working with children with autism spectrum disorders were recruited as advisory panel members. Researchers-developed questionnaire was used. The questionnaire consists of nine to eleven items. Each item consists of a five-point Likert scale for quantitative responses and open-ended questions for qualitative responses. Results: Advisory panel ratings of ‘Good’ to ‘Excellent’ was reported across most items in all three intervention programmes. Overall results suggested that the intervention programmes content was rated to be suitable for children with autism spectrum disorder. Constructive comments were adopted to clarify the activities and structure of the intervention programmes. Final development of the intervention programmes is presented. Conclusion: This study provides confidence for the interventions to be incorporated into the future randomised controlled trial.
10.Ultrasmall, elementary and highly translational nanoparticle X-ray contrast media from amphiphilic iodinated statistical copolymers.
Lu SU ; Kellie S DALBY ; Hannah LUEHMANN ; Sussana A ELKASSIH ; Sangho CHO ; Xun HE ; Lisa DETERING ; Yen-Nan LIN ; Nari KANG ; Dennis A MOORE ; Richard LAFOREST ; Guorong SUN ; Yongjian LIU ; Karen L WOOLEY
Acta Pharmaceutica Sinica B 2023;13(4):1660-1670
To expand the single-dose duration over which noninvasive clinical and preclinical cancer imaging can be conducted with high sensitivity, and well-defined spatial and temporal resolutions, a facile strategy to prepare ultrasmall nanoparticulate X-ray contrast media (nano-XRCM) as dual-modality imaging agents for positron emission tomography (PET) and computed tomography (CT) has been established. Synthesized from controlled copolymerization of triiodobenzoyl ethyl acrylate and oligo(ethylene oxide) acrylate monomers, the amphiphilic statistical iodocopolymers (ICPs) could directly dissolve in water to afford thermodynamically stable solutions with high aqueous iodine concentrations (>140 mg iodine/mL water) and comparable viscosities to conventional small molecule XRCM. The formation of ultrasmall iodinated nanoparticles with hydrodynamic diameters of ca. 10 nm in water was confirmed by dynamic and static light scattering techniques. In a breast cancer mouse model, in vivo biodistribution studies revealed that the 64Cu-chelator-functionalized iodinated nano-XRCM exhibited extended blood residency and higher tumor accumulation compared to typical small molecule imaging agents. PET/CT imaging of tumor over 3 days showed good correlation between PET and CT signals, while CT imaging allowed continuous observation of tumor retention even after 10 days post-injection, enabling longitudinal monitoring of tumor retention for imaging or potentially therapeutic effect after a single administration of nano-XRCM.