36 research outputs found
Effects of leaf maturity of piper sarmentosum (kaduk) on its antioxidant level
Kaduk (Piper sarmentosum) is popular due to its culinary and medicinal properties and has been used traditionally
in different parts of the world to cure many diseases and ailments. One of the studies which was conducted by Forest
Research Institute of Malaysia (FRIM) shows that the extract from P. sarmentosum leaves contains antioxidant
properties. However, a scientific study of its antioxidant level based on leaf maturity has not yet been conducted.
Thus, this study aims to screen the antioxidant activity of P. sarmentosum based on the leaf maturity, from young,
middle-age and matured leaves. The leaves were extracted by maceration using methanol and the antioxidant
activity was determined by 1,1-diphenyl-2-picryl-hydrazyl (DPPH) assay. Results showed that the middle-age leaves
contain the highest antioxidant activity followed by the young and matured leaves. Hence, if P. sarmentosum’s leaves
are to be collected for its antioxidant properties, it is best to harvest the middle-age leaves to gain the optimized
yield of antioxidant properties
Statistical analysis of genomic binding sites using high-throughput ChIP-seq data
This thesis focuses on the statistical analysis of Chromatin immunoprecipitation
sequencing (ChIP-Seq) data produced by Next Generation Sequencing (NGS). ChIP-Seq
is a method to investigate interactions between protein and DNA. Specifically, the method
aims to identify the binding sites of a particular protein of interest, such as a transcription
factor, in the genome. In the context of cancer research, this information is important
to check whether, for example, a particular transcription factor can be considered as a
therapeutic target.
The sequence data produced by ChIP-Seq experiment are in the form of mapped short
sequences, which are called reads. The reads are counted at each single genomic position,
and the read counts are the data to be analysed. There are many problems related to the
analysis of ChIP-Seq data, and in this research we focus on three of them.
First, in the analysis of ChIP-Seq data, the genome is not analysed in its entirety; instead
the intensity of read counts is estimated locally. Estimating the intensity of read counts
usually involves dividing the genome into small regions (windows). If the window size
is small, the noise level (low read counts) would dominate and many empty windows
would be observed. If the window size is large, the windows would have many small read
counts, which would smooth out some important features. The need exists for an approach
that enables researchers to choose an appropriate window size. To address this problem,
an approach was developed to optimise the window size. The approach optimises the
window size based on histogram construction. Note, the developed methodology is
published in [46].
Second, different studies of ChIP-Seq can target different transcription factors and then
give different conclusions, which is expected. However, they are all ChIP-Seq datasets
and many of them are performed on the same genome, for example the human genome.
So is there a pattern for the distribution of the counts? If the answer is yes, is the pattern common in all ChIP-Seq data? Answering this question can help in better understanding
the biology behind this experiment. We try to answer this question by investigating
RUNX1/ETO ChIP-Seq data. We try to develop a statistical model that is able to describe
the data. We employ some observed features in ChIP-Seq data to improve the performance
of the model. Although we obtained a model that is able to describe the RUNX1/ETO
data, the model does not provide a good statistical fit to the data.
Third, it is biologically important to know what changes (if any) occur at the binding sites
under some biological conditions, for example in knock-out experiments. Changes in the
binding sites can be either in the location of the sites or in the characteristics of the sites
(for example, the density of the read counts), or sometimes both. Current approaches for
differential binding sites analysis suffer from major drawbacks. First, unclear underlying
models as a result of dependencies between methods used, for example peak finding and
testing methods. Second, lack of accurate control of type-I error. Hence there is a need
for approach(es) to address these drawbacks. To address this problem, we developed three
statistical tests that are able to detect significantly differential regions between two ChIPSeq
datasets. The tests are evaluated and compared to some current methodologies by
using simulated and real ChIP-Seq datasets. The proposed tests exhibit more power as
well as accuracy compared to current methodologies
Risk factors and predictors of levodopa-induced dyskinesia among multiethnic Malaysians with Parkinson's disease
Chronic pulsatile levodopa therapy for Parkinson's disease (PD) leads to the development of motor fluctuations and dyskinesia. We studied the prevalence and predictors of levodopa-induced dyskinesia among multiethnic Malaysian patients with PD. Methods: This is a cross-sectional study involving 95 patients with PD on uninterrupted levodopa therapy for at least 6 months. The instrument used was the UPDRS questionnaires. The predictors of dyskinesia were determined using multivariate logistic regression analysis. Results: The mean age was 65.6 ± 8.5 years. The mean onset age was 58.5 ± 9.8 years. The median disease duration was 6 (7) years. Dyskinesia was present in 44% (n = 42) with median levodopa therapy of 3 years. There were 64.3% Chinese, 31% Malays, and 3.7% Indians and other ethnic groups. Eighty-one percent of patients with dyskinesia had clinical fluctuations. Patients with dyskinesia had lower onset age ( p < 0.001), longer duration of levodopa therapy ( p < 0.001), longer disease duration ( p < 0.001), higher total daily levodopa dose ( p < 0.001), and higher total UPDRS scores ( p = 0.005) than patients without dyskinesia. The three significant predictors of dyskinesia were duration of levodopa therapy, onset age, and total daily levodopa dose. Conclusions: The prevalence of levodopa-induced dyskinesia in our patients was 44%. The most significant predictors were duration of levodopa therapy, total daily levodopa dose, and onset age
Nanograin study of polycrystalline ceramics based on cerate-zirconate via two-step sintering / Azliana Ramli … [et al.]
Increasing in the energy demand lead the world to focus on an alternative energy conversion technologies. Solid oxide fuel cells (SOFCs) offer more efficiency in conversion of chemical energy in fuels into electricity. There is worldwide interest in reducing the operating temperature of SOFCs to 500-700°C for long-term stability and lower cost. Proton conducting solid oxide fuel cells (PCFCs) are under intense study due to their lower operating temperature < 800°C compared to the conventional oxygen ion conducting solid oxide fuel cells [1]. Cerate-zirconate ceramics with perovskite structure of ABO3 is one of the promising candidates as solid electrolyte for PCFCs applications due to its low activation energy for proton conduction. A better understanding of proton conduction in this material requires a systematic study on the role of synthesizing process and heat treatment in controlling the material's microstructure
‘Crescendo transient ischemic attack’—an uncommon presentation of a very common disease: a case report on capsular warning syndrome
Capsular warning syndrome is a rare presentation of transient ischaemic attack, which described as recurrent episodes of motor and/or sensory deficits which typically sparring the cortical function. It has a significant risk to progress into a massive stroke with permanent disability, thus important to be recognize early. Here, we report a middle-aged gentleman with no known medical illness presented with eight episodes of transient ischaemic attack within the span of 24 h. He was treated with double anti-platelet for 21 days and was not subjected to thrombolysis at time of presentation because it was outside the window period of 4.5 h and has fully recovered after each episode. The purpose of this case report is to share the uncommon clinical presentation of transient ischaemic attack, which is still not fully understood and warrant more studies especially on the treatment that can affect the progression of the disease
Biochemical aspirin resistance in stroke patients: a cross-sectional single centre study
Background: Aspirin use is known to reduce the recurrence of stroke. However, the clinical response to aspirin has been mixed. The rate of stroke recurrence whilst on aspirin treatment is still unacceptably high. A plausible explanation for this may be resistance to the effects of
aspirin. The causes of aspirin resistance are manifold and multi-factorial. We conducted a study to investigate the prevalence rate of biochemical aspirin resistance in a cohort of aspirin-naïve stroke patients. We also sought to determine the inherent factors that may predispose towards the development of aspirin resistance.
Method: This was a cross-sectional, observational study conducted on patients admitted to our centre with an acute stroke who were aspirin-naïve. The diagnosis of an acute stroke was confirmed by clinical history and brain imagi
ng. Fifty consecutive patients were prospectively enrolled. Socio demographic data were collected and baseline blood investigations were performed. Patients were tested for biochemical aspirin resistance using Multiplate platelet
analyser (Dynabyte, Munich, Germany) after 5 doses of aspirin, corresponding to a total dose of 900 mg.
Results: The median age of patients was 65.5 years and 54 % of patients were female. There were 11 smokers; of these 10 were male. Twenty-six (52 %) patients were Chinese, 21 (41%)
were Malay and 3 (6.0 %) were Indian. Aspirin resistance was present in 14 % of our patients.There was an inverse relationship between the presence of aspirin resistance and plasma HDL levels (r = -0.394; p = 0.005). There was no relationship observed between aspirin resistance and total cholesterol, triglycerides, LDL, HbA1c, ALT, ALP, urea and creatinine levels. There were no significant differences in demographic profiles or smoking status between the aspirin resistant and non-aspirin resistant groups. We did not find any link between ethnicity and aspirin resistance.
Conclusions: Our results indicate that a lower HDL leve
l is associated with biochemical aspi-rin resistance. This may increase platelet aggregation and consequently increase the risk of a recurrent stroke. The clinical implications
for aspirin resistance are far reaching. Any evidence that correctable factors may negatively influence the action of aspirin warrants further investigation. The prevalence rate of biochemical aspirin resistance in our study is comparable to the findings in other studies performed in an Asian population. Further research is required to determine how our findings translate into clinical aspirin resistance and stroke recurrence
Biochemical aspirin resistance in stroke patients - a cross-sectional single centre study
Aspirin use is known to reduce the recurrence of stroke. However, the clinical response to aspirin has been mixed. The rate of stroke recurrence whilst on aspirin treatment is still unacceptably high. A plausible explanation for this may be resistance to the effects of aspirin. The causes of aspirin resistance are manifold and multi-factorial. We conducted a study to investigate the prevalence rate of biochemical aspirin resistance in a cohort of aspirin-naïve stroke patients. We also sought to determine the inherent factors that may predispose towards the development
of aspirin resistance. Method: This was a cross-sectional, observational study conducted on patients admitted to our centre with an acute stroke who were aspirin-naïve. The diagnosis of an acute stroke was
confirmed by clinical history and brain imaging. Fifty consecutive patients were prospectively enrolled. Socio-demographic data were collected and baseline blood investigations were performed. Patients were tested for biochemical aspirin resistance using Multiplate® platelet analyser (Dynabyte, Munich, Germany) after 5 doses of aspirin, corresponding to a total dose of 900 mg. Results: The median age of patients was 65.5 years and 54 % of patients were female. There were 11 smokers; of these 10 were male. Twenty-six (52 %) patients were Chinese, 21 (41 %) were Malay and 3 (6.0 %) were Indian. Aspirin resistance was present in 14 % of our patients. There was an inverse relationship between the presence of aspirin resistance and plasma HDL levels (r = -0.394; p = 0.005). There was no relationship observed between aspirin resistance and total cholesterol, triglycerides, LDL, HbA1c, ALT, ALP, urea and creatinine levels. There were no significant differences in demographic profiles or smoking status between the
aspirin resistant and non-aspirin resistant groups. We did not find any link between ethnicity and aspirin resistance. Conclusions: Our results indicate that a lower HDL level is associated with biochemical aspirin resistance. This may increase platelet aggregation and consequently increase the risk of a recurrent stroke. The clinical implications
for aspirin resistance are far reaching. Any evidence that correctable factors may negatively influence the action of aspirin warrants further investigation. The prevalence rate of biochemical aspirin
resistance in our study is comparable to the findings in other studies performed in an Asian population. Further research is required to determine how our findings
translate into clinical aspirin resistance and stroke recurrence
Sickle Cell Illness Awareness among the General Public
Background: Lifelong ickle cell disease (SCD), a group of inherited blood disorders, afflicts millions of individuals. Sickle cell disease (SCD), with a global prevalence of 112 cases per 100,000 individuals, frequently gives rise to this condition. Sickle Cell Disease (SCD) exhibits a high prevalence in various regions, including Sub-Saharan Africa, Saudi Arabia, India, South and Central America, as well as the Mediterranean. We conducted a study in Tabuk, Saudi Arabia to assess the level of public knowledge and awareness of Sickle Cell Disease (SCD). Methods: The present study employed a cross-sectional observational design, encompassing a sample of 386 individuals residing in Tabuk, who were over the age of 18 and represented both genders and various nationalities. Demographic data and sickle cell disease awareness were obtained through the utilization of a structured questionnaire that was developed from previous research. Results: The present study included a total of 386 adults residing in Tabuk, Saudi Arabia, who satisfied the predetermined inclusion criteria. Among the participants, 47.4% fell between the age range of 18 to 25 years. The majority of participants had a satisfactory level of knowledge, with 24.1% of individuals aged 18-25, 10.1% of those aged 26-35, 7.3% and 6.55% of individuals aged 36-45, and a significant proportion of participants aged over 45. Conclusion: The survey participants demonstrated a satisfactory degree of understanding on the prevalence of sickle cell disease (SCD) in the Kingdom of Saudi Arabia (KSA). 
The effects of intravenous infusion of autologous mesenchymal stromal cells in patients with subacute middle cerebral artery infarct: a phase 2 randomized controlled trial on safety, tolerability and efficacy
Background aims Mesenchymal stromal cells (MSCs) are characterized by paracrine and immunomodulatory functions capable of changing the microenvironment of damaged brain tissue toward a more regenerative and less inflammatory milieu. The authors conducted a phase 2, single-center, assessor-blinded randomized controlled trial to investigate the safety and efficacy of intravenous autologous bone marrow-derived MSCs (BMMSCs) in patients with subacute middle cerebral artery (MCA) infarct. Methods Patients aged 30-75 years who had severe ischemic stroke (National Institutes of Health Stroke Scale [NIHSS] score of 10-35) involving the MCA territory were recruited within 2 months of stroke onset. Using permuted block randomization, patients were assigned to receive 2 million BMMSCs per kilogram of body weight (treatment group) or standard medical care (control group). The primary outcomes were the NIHSS, modified Rankin Scale (mRS), Barthel Index (BI) and total infarct volume on brain magnetic resonance imaging (MRI) at 12 months. All outcome assessments were performed by blinded assessors. Per protocol, analyses were performed for between-group comparisons. Results Seventeen patients were recruited. Nine were assigned to the treatment group, and eight were controls. All patients were severely disabled following their MCA infarct (median mRS = 4.0 [4.0-5.0], BI = 5.0 [5.0-25.0], NIHSS = 16.0 [11.5-21.0]). The baseline infarct volume on the MRI was larger in the treatment group (median, 71.7 [30.5-101.7] mL versus 26.7 [12.9-75.3] mL, P = 0.10). There were no between-group differences in median NIHSS score (7.0 versus 6.0, P = 0.96), mRS (2.0 versus 3.0, P = 0.38) or BI (95.0 versus 67.5, P = 0.33) at 12 months. At 12 months, there was significant improvement in absolute change in median infarct volume, but not in total infarct volume, from baseline in the treatment group (P = 0.027). No treatment-related adverse effects occurred in the BMMSC group. Conclusions Intravenous infusion of BMMSCs in patients with subacute MCA infarct was safe and well tolerated. Although there was no neurological recovery or functional outcome improvement at 12 months, there was improvement in absolute change in median infarct volume in the treatment group. Larger, well-designed studies are warranted to confirm this and the efficacy of BMMSCs in ischemic stroke
Impulse control behaviours in a Malaysian Parkinson’s disease population
Background: Impulse control behaviours are repetitive and excessive activities that may be sub-syndromal and not fulfill the criteria for impulse control disorder. These activities have potential to negatively impact on the daily lives of sufferers. We conducted a study to investigate the prevalence of impulse control behaviors and its associated features in Parkinson’s disease in our population. Methods: We conducted a prospective cross-sectional study on consecutive patients attending neurology clinic. Inclusion criteria include idiopathic Parkinson’s disease patients with Hoehn & Yahr stage I-IV. Eighty patients were enrolled and screened for impulse control behaviors using the Questionnaire for Impulsive-Compulsive Disorder for Parkinson’s disease (QUIP). Results: Prevalence of impulse control behaviors among our cohort was 11.3%; the features significantly associated with it were higher level of education (p=0.02), advanced stage of disease (p=0.03) and higher levodopa dosage (p= 0.01). The commonest impulse control behavior in our cohort was compulsive medication use (7.5%), followed by hobbyism (6.3%), hypersexuality (5%), compulsive buying (3.75%), punding (2.5%), walkabout (2.5%), compulsive eating (1.25%) and pathological gambling (1.3%). Conclusions: There is an association between impulse control behavior and higher levodopa dosage in a study on patients with Parkinson’s disease in Malaysia. We also found a low prevalence of pathological gambling as compared to studies performed in the West