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Inhibited Dopamine Synthesizing Cell Model of AADC Deficiency

Introduction: Aromatic L-amino acid decarboxylase deficiency (AADC) is a rare autosomal recessive pediatric neurotransmitter disease. To date it remains poorly understood mainly due to an absence of a disease model. The dopaminergic neuroblastoma cell SH-SY5Y was chosen to develop our AADC deficiency model. These cells are not native dopamine synthesizers. Objective: To develop a dopamine-producing cellular model of AADC deficiency using SH-SY5Y neuroblastoma cells. Methods: Dopamine pathway proteins were identified with Western Blotting. Dopaminergic differentiation was attempted using all-trans retinoic acid (ATRA) with dopamine detection via HPLC-ECD post alumina extraction. Treatment with L-DOPA provided SH-SY5Y with excess precursor. RT-PCR was used to determine the expression of markers of mature neurons. Results: Western Blot screening identified AADC, dopamine β-hydroxylase and tyrosine hyrdoxylase proteins, indicative of a dopaminergic pathway. ATRA was unsuccessful in producing dopamine from the cells. L-DOPA treatment however, generated dopamine first visible as a HPLC-ECD peak 30 minutes post-incubation. Prior to this, SH-SY5Y dopamine synthesis from L-DOPA has never been documented. This de novo synthesis is then inhibited using benserazide to form our AADC deficiency cell model. RT-PCR showed that SH-SY5Y cells express markers of mature neurons in its ‘native’ state and is not affected by L-DOPA and benserazide treatment. This cell model will potentially benefit many areas of AADC deficiency research. Conclusion: SH-SY5Y cells   produced HPLC-ECD measureable amounts of dopamine with the addition of L-DOPA.    Our model of AADC deficiency is generated by quelling the dopamine production with Benserazide.

Torque Teno Virus and Hepatitis: A review on correlation.

Torque teno virus (TTV) is one of the “orphan” virus that have been discovered almost two decades ago, with little information on the relationship of the infection to any diseases. It is one of the 45% of commensal virus which was found throughout the population and becoming one of the most extensively studied viruses on its prevalence among various level of health status. From healthy blood donors to patients who suffered severe illness, TTV infection level seems to be high and the findings has triggered an interest from the researcher. Even though the study on TTV prevalence is actively performed, the actual pathogenesis of TTV to any specific diseases is yet to be ascertained. Many suggestions on the possible association of TTV infection with severe diseases such as acute respiratory diseases, liver-related diseases and even cancer have been discussed. However, one type of diseases which might have an association with TTV is hepatitis. Albeit, it remains a theory as the actual pathogenicity of TTV is not fully understood.

Validation of A2 Blood Subgroup through Genetic Sequence Analysis

ABO blood grouping is an important antigenic blood typing tools in blood transfusion and organ transplants. Mismatching of blood during transfusion would lead to undesired transfusion reactions. Due to rare occurrence of rare blood group such as A2 subtype, regular blood grouping technique would have missed the identification of blood group. In this study, the identification of A2 subgroup using routine serological technique was validated via DNA sequencing technique. A total of 656 students participated in this study consist of Malay (87.0 %), Chinese (0.4 %), Indian (11.4 %) and others ethnic group (0.9%) respectively. Monoclonal antisera A, B, AB, D, A1 lectin and H lectin were used to identify the antigen on red blood cells. DNA sequence analysis was applied to examine single nucleotide polymorphisms (SNPs) at position 467 (substitution of C>T) and 1061 (deletion of C) on coding region of ABO gene. Our findings showed of 656 blood samples, 256 (39.0%) were blood group O, 190 (29.0%) were blood group B, 179 (27.3%) were blood group A and 31(4.7%) were blood group AB. The frequency of A1 subgroup is 177 (99.0%) and A2 subgroup is 2 (1.0%). From 179 A blood group, only 2 samples showed negative reaction towards anti-A1 lectin. DNA sequence analysis revealed the SNPs at nucleotide 1061 position in sample 2, however sample 1 did not have this mutation and the subgroup was not identified. DNA sequencing provides a precise and high accuracy in identification of A subgroups.

Medicinal bioactive compounds to functional foods from geochemical signatures marine biomasses: sea cucumbers, macroalgae and crown of thorns biomasses

Recognition of health benefits associated with consumption of marine derived biomasses is one of the most promising developments in human nutrition and disease-prevention research. This endeavor for bioactives and functional ingredients discovery from marine sources is “experience driven,” as such the search for therapeutically useful synthetic drugs, and functional components is like “looking for a needle in a haystack,” thus a daunting task. Zoonotic infection, adulteration, global warming and religious belief can be the star-gate barrier: - For example, the outsourcing for Glycosaminoglycans (GAGs), a pharmacologically bioactive compound have emerged as novel biomarkers and molecular players both within tumor cells and their microenvironment, as they integrate signals from growth factors, chemokines, integrins, and cell-cell matrix adhesion. As such, worldwide initiatives in outsourcing from geochemical signatures marine biomasses are flourishing. Most of these scientific interests are related to marketable compounds optimised via biotechnology applications. Approximately 50% of the US FDA approved drugs during 1981–2002 consist of either marine metabolites or their synthetic analogs. These bioactive compounds acts as antioxidant, peptides, chitoligosaccharides derivatives, sulfated polysaccharides, phlorotannins and carotenoids. Highlights from works to harness and provide scientific support to folk medicine much claimed legacy, pertaining to geochemical signatures vouchered sea cucumbers, macroalgae and crown of thorns starfish will be extrapolated.

Effects of Melicope ptelifolia Aqueous Extract on Sperm Parameters and Testosterone Level in Sprague-Dawley Rats

The increasing number of prevalence infertility cases is becoming a major public health problem in developing countries due to changes in diet and lifestyle. Melicope ptelefolia is known for its health benefit as a sex enhancing effect among the Malays folk however there is no clinical data to prove it until these days. The main aim of the present study is to identify the effects of Melicope ptelifolia Aqueous extract (MPAE) on Sperm Parameters and Testosterone Level . A total of 30 male Sprague Dawley rats were divided equally into five different groups. MPAE was given by orally gavage for 28 days at a dose of 100mg/kg, 200 mg/kg and 500 mg/kg body weight to the animals of group II (n=6), III (n=6) and IV (n=6), respectively. The animals of group I (control, n=6) had distilled water and group V had sildenafil citrate. Results were analyzed using one way ANOVA test and the data were significant at p<0.05. Oral administration of MPAE extract showed an increased sperm count and sperm viability. Oral administration of the MPAE resulted a significant increased (p<0.05) for Group II, III and IV in sperm count and sperm morphology. A significant increased increased was recorded for Group I, II, III and IV in sperm viability. However, sperm vitality remained normal in all the groups. From our present experimental findings we are tempted to suggest that the MPAE could be a potential male fertility agent.

Profiles and Biological Values of Sea Cucumbers: A Mini Review

Sea cucumbers, blind cylindrical marine invertebrates that live in the ocean intertidal beds have more than thousand species available of varying morphology and colours throughout the world. Sea cucumbers have long been exploited in traditional treatment as a source of natural medicinal compounds. Various nutritional and therapeutic values have been linked to this invertebrate. These creatures have been eaten since ancient times and purported as the most commonly consumed echinoderms. Some important biological activities of sea cucumbers including anti-hypertension, anti-inflammatory, anti-cancer, anti-asthmatic, anti-bacterial and wound healing. Thus, this short review comes with the principal aim to cover the profile, taxonomy, together with nutritional and medicinal properties of sea cucumbers.

Effect of Open Top Chamber as Global Warming Model on Soil Chemical Properties and Microbial Growth

Global warming is the main concern in today’s century as it comes with numerous side effects on the natural environment. Open Top Chambers (OTC) consist of metal constructions with transparent vertical side-walls and a frustum on top. An opening in the middle of the frustum allows an air exchange to reduce temperature and humidity effects in the chamber. The size of the open top chamber which is located in Universiti Putra Malaysia is slanted 60o, 50cm tall, 2.08m basal diameter hexagon chamber. The Open Top chamber experiments were carried out to determine how much global warming has affected and is still affecting the temperature, pH, the moisture and the growth of the microbes in the tropical soil. The aim of this study is to elucidate the effects of temperature increase on the soil microbes’ population and on the pH of the soil. The study was conducted to observe the effect of heat on soil microbes, and the pH of the soil which was collected on the same day for 6 consecutive months. The microbes values were then used for Colony Forming Unit (CFU) value calculations. The effects of OTCs on mean temperature showed a large range of CFU values throughout the 6 months but did not differ significantly between studies. Increases in mean monthly and diurnal temperature were strongly related, indicating that the presence of warming effect by the OTCs. Such predictive power allows a better mechanistic understanding of observed biotic response to experimental warming. This study will be useful for the understanding of the global warming effect on microbes. The open top chamber has proven to be one of the effective model for global warming research and data collected especially on the growth of soil microbial obtained would be off great use for further experiments.

Invadopodia Formation is a Critical Step in Cancer Cell Invasion: The Effect of Passage Number on Invadopodia Formation in MDA-MB-231 Breast Cancer Cell Line

High invasive cancer cells are thought to recruit specialised actin-rich protrusions for invasion in metastasis process. These protrusions are termed invadopodia. To study invadopodia formation, one of the first challenges faced by researchers has been to optimise the cell line passage number in order to be used for the invadopodia assay. Therefore, this study aims to investigate the effects of the passage number on invadopodia formation in MDA-MB-231 breast cancer cell line. Invadopodia assay was used to achieve the aim of the study. The results provided evidence that invadopodia formation is affected by the high passage number. The cells were also tested with dimethyloxalylglycine (DMOG) a hypoxic mimicking agent which is known to be an invadopodia inducer, the results showed that the cells in low passage number (P7) treated with DMOG increase the cells forming invadopodia, while the cells with high passage number (P35) showed that DMOG fails to stimulate the cells to form invadopodia. Furthermore, the cells with high passage number after passage 15 are starting to lose the ability to degrade the gelatin. In conclusion, this study suggests that only cells with a low passage number, less than passage 15 should be used in the study of invadopodia formation to obtain the results in the search for molecular targets and signaling at invadopodia.

The Effect of DMEM and DMEM:F12 Culture Media on the Growth of SH-SY5Y Cells

The human neuroblastoma cell line, SH-SY5Y cells, is commonly used as an in vitro model for neuroscience and neurobiology research. SH-SY5Y cells were established during the 1970’s from the parental metastatic bone tumor, SK-N-SH cell line. The utilization of SH-SY5Y cells in neurobiology research is due to their resemblance to the human primary neuronal cells with several limitations, considering the cells are derived from malignant tumor cells. Since SH-SY5Y cells are widely cultured for research, several different culture media have been used to optimize the growth of the cells, including Eagle's Minimum Essential Medium (EMEM), Dulbecco’s modified Eagle’s medium (DMEM) and other recently developed culture media. The ability of SH-SY5Y cells to reach confluency in culture flasks ranges from 5 days to 15 days, depending on the culture media. Hence, the optimization of the culture media is crucial to achieve the fastest growth rate for the cells. The objective of the study is to evaluate the culture media for the proliferation of SH-SY5Y cells. We compared the growth rate of SH-SY5Y cells cultured in Dulbecco’s modified Eagle’s medium (DMEM) supplemented with 15% heat-inactivated fetal bovine serum (hiFBS), Dulbecco’s modified Eagle’s medium: Nutrientmixture F-12 (DMEM:F12) + supplemented with 15% hiFBS and DMEM:F12 supplemented with 10% hiFBS. In DMEM:F12 supplemented with 15% hiFBS, cells grew up to 6.67E+05 cells. In DMEM:F12 supplemented with 10%hiFBS, cells grew up to 5.28E+05 cells. In DMEM supplemented with 15% hiFBS, the cells grew up to 4.76E+05 cells. There was a significant difference between culture media DMEM:F12 supplemented with 15% hiFBS as compared to DMEM:F12 supplemented with 10%hiFBS and DMEM supplemented with 15% hiFBS (p<0.05) following 24h incubation. However, there is no significant difference between DMEM:F12 supplemented with 10%hiFBS as compared to DMEM supplemented with 15% hiFBS (p>0.05).

Intracellular stored calcium plays a minor role in Gq-coupled receptor-mediated contraction in rat airway smooth muscle

The general notion of activation of Gq-protein coupled receptors involves the mobilisation of stored and extracellular calcium and leads to smooth muscle tissue contraction. The aim of this study was to investigate the involvement of calcium mediated contractions in vascular and airway smooth muscles. Using the standard organ bath procedures, aortic and tracheal rings were obtained from 6 to 8 week-old male Sprague Dawley rats. To activate the Gq protein receptors, phenylephrine (PE), an α1-adrenoceptor agonist, and carbachol, a M3 cholinoceptor  agonist, was added to baths containing the aortic and tracheal rings, respectively.  The maximum response (Emax) to PE was reduced from 158.8 ± 11.8% (n=6) to 62.5 ± 12.4 % (n=8) upon removal of extracellular calcium in Krebs-Ringer solution. Maximal response to PE was also suppressed in the presence of nifedipine, a L-type Ca2+ channel inhibitor,  (70.3 ± 11 %, n=8) and SKF96365, a canonical transient receptor potential channel inhibitor, (26.7 ± 13.2 %, n=5) when the influx of extracellular calcium was blocked. Removal of stored calcium also attenuated the PE contraction (p<0.05). Contractile responses to carbachol in the airway were totally abolished in the absence of calcium in the Krebs-Ringer solution (208.6 ± 23 % [n=8] vs 10.7 ± 4.2 % [n=3]). This is different from the aorta where a measurable response was detected despite the absence of external calcium. Blockage of extracellular calcium influx in the presence of nifedipine and SKF96365 also showed similar lack of responses in trachea. Interestingly, removal of stored calcium did not affect the carbachol responses (p>0.05). From these observations, we conclude that the role of stored and extracellular calcium in Gq protein activation is not the same across different type of smooth muscle tissues.

Macroeconomic Factors and Stock Price in Malaysia

Stock prices move every seconds, up and down, and it never waits for an investor to make a decision. Investors, economists and the policy makers needs to understand the macroeconomic factors that influences the stock price as the factors plays a critical role in shaping the stock market. Furthermore, economists and policy makers should know how to react when the factors change, while investors should understand whether or not they should invest their money. Seven macroeconomic variables were collected for this study, which is the earnings per share, lending interest rate, consumer price index, gross domestic product, average crude oil price, dividend per share, and narrowed money supply (M1). However, due to strong correlation among the variables, earnings per share, gross domestic product, the average crude oil price, and narrowed money supply is excluded in regression model. Dividend per share, consumer price index, and lending interest rate is used in this study. The results of this paper reflected that gross domestic product, oil price and money supply are strongly correlated; inflation is statistically significant and positively influence the stock price, and finally the lending interest rate negatively influence the stock price.

Management Style in Retaining Loyal Customers and Quality of Products: A Case Study of Starbucks

The success of the coffee company in influencing the people’s preference in buying coffee is something that could grab the attention of everybody. Customers are willing to spend a high amount of money for a cup of coffee simply because of the quality of the products and brand image that the company offers. With their loyal customers, it has always been Starbucks best way of advertising the brand or their coffee by word-of-mouth. Despite having loyal customers because they have passion for coffees, Starbucks still find its way to retain their loyal customers with improvised strategies and upcoming promotions.

Financial Risk Tolerance: Malaysia

Financial risk tolerance (FRT) is a matter adamant in understanding the underlying issues of financial decisions, in that, it is an important component of investment. The demographic variables; age, gender, income level and birth order are explored in this study to see if there are any significant differences across each of the variables. This study indicates the need for further contribution to the literature of financial risk tolerance in Malaysia as location differential herald different culture and environment, thus, different constituent of financial risk tolerance factors.

Risk and Return Evaluation of Malaysian Mutual Fund Market

Mutual funds are growing tremendously in Malaysia. Many investors have no time to select individual stocks or bonds in the market due to limited time, money and knowledge. Hence, mutual fund has to show up as a useful and preferred investment tool in the Malaysian market. Ten portfolios were chosen from two prominent mutual fund companies in Malaysia. Performance evaluation and risk measurements were applied to understand the performance of each portfolio. Paired T-test was tested on two portfolios with 45 individual stock in each portfolio. The result was rather intriguing as what was initially expected. There appear to be a difference in terms of decision when applying fundamental measurement using existing concept and measures such as Sharpe and Treynor. To conclude, there is no significant difference in items of risk and return performance in Conventional and Islamic mutual funds. However, further validation can be done with larger sample size or portfolio.

The Determinants of Capital Structure in Malaysian Companies

In Malaysia, organization take a gander at the association between capital structure and market structure, particularly advantage. The current financial crisis has put awesome weight on residential and worldwide firms, particularly failing to meet firms’ expectations. The supply of credit has dropped drastically, while expanded hazard and an expanded cost of capital weight firms in finding the correct value of firm. Capital structure has been the subject of numerous surviving investigations, in which analysts intend to archive the connection between capital structure and firm performance. From a company's point of view, finding and working at the ideal capital structure could be useful. Capital structure essentially influences the cost and accessibility of capital, which thus will likewise influence a company's performance. For this study, 90 listed companies were chosen from five various industries for the period 2014 to 2017. This research has included six independent variables includes profitability, tangibility, firm size, growth, age and liquidity. The results indicate that profitability, tangibility and age are the key determinants of capital structure decision in Bursa Malaysia listed companies.

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Professor Dr Cheah Yoke Kqueen

Professor Dr Cheah Yoke Kqueen currently serves as Deputy Director of the Centre for Industry Relations and Networks (CiRNeT), Universiti Putra Malaysia.

Prof. Dr. Cheah earned his bachelor’s degree in Biomedical Science (1998), a Master of Science in Molecular Biology (2001), a PhD in Genetic Engineering and Molecular Biology (2006) and a Postgraduate Diploma in Bioinformatics (2018).