Differential Protein Expression in Response to Varlitinib Treatment in Oral Cancer Cell Line: an In Vitro Therapeutic Approach

Epidermal growth factor receptor (EGFR) is the most frequently overexpressed receptor histologically exhibited by oral squamous cell carcinoma (OSCC) patients. Aberrated EGFR signaling may lead to recurrence and metastasis, thus laying the foundation of targeted therapy. Deactivating EGFR is likely to prevent downstream signaling thus resulting in apoptosis. Tyrosine kinase inhibitors (TKIs) have come into play to revert aggressiveness of OSCC. We exploited comparative proteomic analyses based on anti-EGFR potential of varlitinib, using cellular proteomes from treated and untreated groups of oral cancer cells to identify protein players functional during oral carcinogenesis. Following separation by two-dimensional electrophoresis, differentially expressed cellular proteins (varlitinib-treated and untreated cells) were analyzed and later identified using QTOF mass spectrometer. In silico analysis for protein-protein interaction was carried out using STRING. Six differentially expressed proteins were identified as binding immunoglobulin protein (BiP), heat shock protein 7 C (HSP7C), protein disulfide isomerase 1 A (PDIA1), vimentin (VIME), keratin type I cytoskeletal 14 (K1C14), and β-Actin (ACTB). Relative expression of five proteins was found to be downregulated upon varlitinib treatment, whereas only K1C14 was upregulated in treated cells compared to control. Protein network analysis depicts the interaction between BiP, PDIA1, VIME, etc. indicating their role in oral carcinogenesis. Oral cancer cells show proteome shift based on varlitinib treatment compared to corresponding controls. Our data suggest candidature of varlitinib as a potent therapeutic agent and BiP, PDIA1, HSP7C, VIME, and β-Actin as complementary/prognostic markers of OSCC.

DNA Repair Enzyme XRCC4 30 bp Indel Intron 3 Locus Significant Association with Predisposition of Cataract in Senility

Impaired DNA damage repair cascade can disrupt the lens transparency due to aging-associated oxidative stress. The aim of study was to assess the association of 30 bp indel mutation (rs28360071) in XRCC4 gene with susceptibility of cataract in senility. The study followed case-control design with a total of n = 200 participants and divided equally into senile cataract patients and control groups. Conventional polymerase chain reaction (PCR) was performed for the genotyping of XRCC4 (rs28360071) mutation. In statistical measures, SPSS ® 20.0 software, MedCal©, and SNPStats© tools were used for data analysis. Distribution of homozygous D/D and mutant D allele was higher in senile cataract patients in comparison to controls. XRCC4 (rs28360071) mutation was significantly associated with predisposition senile cataract (χ2 = 13.96, adjusted OR = 2.29, 95% CI: 1.5-3.4, p < 0.001). Codominant model was suggested to be a best fit model. Mutant D/D genotype described significant association with LDL (adjusted OR = 1.67, 95% CI: 0.14-1.45, p = 0.03),and HDL (adjusted OR = 1.66, 95% CI: 0.92-2.31, p = 0.05) cholesterol with higher risk of senile cataract. XRCC4 (rs28360071) mutation may serve as a potential biomarker for the prognosis of cataract in senility. It can used to measure interruption in NHEJ repair pathway to indicate DNA damage in lens epithelial cells which could accelerate cataractogenesis with aging.

Chemical Hypoxic Preconditioning Improves Survival and Proliferation of Mesenchymal Stem Cells

Increasing evidence has demonstrated that mesenchymal stem cells (MSCs) have been linked to tissue regeneration both in vitro and in vivo. However, poor engraftment and low survival rate of transplanted MSCs are still a major concern. It has been found that the proliferation, survival, and migration of MSCs are all increased by hypoxic preconditioning. However, the molecular mechanism through which hypoxic preconditioning enhances these beneficial properties of MSCs remains to be fully investigated. Therefore, the present study is aimed to investigate the mechanism by which hypoxic preconditioning enhances the survival of MSCs. We used proteomic analysis to explore the molecules that may contribute to the survival and proliferation of hypoxic preconditioned (HP) MSCs. The analysis revealed a higher expression of prelamin A/C (Lmna), glutamate dehydrogenase 1(Glud1), Actin, cytoplasmic 1(Actb), Alpha-enolase (Eno1), Glucose-6-phosphate 1-dehydrogenase (G6pd), Protein disulfide-isomerase A3 (Pdia3), Malate dehydrogenase (Mdh1), Peroxiredoxin-6 (Prdx6), Superoxide dismutase (Sod1), and Annexin A2 (Anxa2) in HP-MSCs. These proteins are possibly involved in cellular survival and proliferation through various cellular pathways. This research could aid in understanding the processes involved in hypoxic preconditioning of MSCs and designing of cell-based therapeutic strategies for tissue regeneration.

Novel Synergistic Combination of Pamidronate and Temozolomide for Breast Cancer Therapeutics

OBJECTIVE

Human breast cancer is among one major health concerns with high prevalence and mortality among women worldwide. Various cellular signaling pathways are implicated in carcinogenesis. One of the major pathways that affect the downstream cellular growth cascades is Mevalonate pathway (MVA). The inhibition of MVA is therapeutically beneficial for various cancers. Pamidronate (PAM) (MVA inhibitor), a nitrogen-containing bisphosphosphonate, is an antiresorptive FDAapproved drug. The objective of our study was to explore adjuvant therapy using a combination of PAM and an alkylating agent, Temozolomide (TMZ) against breast cancer.

METHODS

We have examined the differential gene and protein expression in response to the combination treatment strategy. For gene expression analysis RT-qPCR and for proteomic study, twodimensional gel electrophoresis and mass spectrometry techniques were utilized.

RESULTS

Combination treatment (PAM+TMZ) showed more pronounced cytotoxic effect as compared to single agent treatment. Our results indicate that MVA pathway regulatory genes (FDFT1, FDPS, KRAS) are significantly (p<0.05) downregulated in combination-treated breast cancer cells. The differential proteomic analysis showed lower expression of GFAP, PPA1 and TRIM68 proteins after synergistic treatment whereas, these proteins are found to be up-regulated in multiple cancers.

CONCLUSION

The present study reveals that a combination of PAM and TMZ produces an effective anti-cancerous effect on breast cancer cells. Therefore, this novel therapeutic regimen is likely to provide a better treatment strategy for breast cancer.

Oxidative stress and PON1 (T172A/L55M) polymorphism: potential risk factors for Osteoarthritis

Objective: To investigate the role of oxidative stress in the progression of osteoarthritis with the genetic determinant of paraoxonase-1 enzyme L55M in osteoarthritis patients. Method: The case control study was carried out at the University of Karachi from April to November 2020, and comprised blood samples of female osteoarthritis patients aged >50 years and healthy controls matched for age and gender. Oxidative stress was assessed by measuring lipid peroxidation product and protein carbonyl content. Activities of paraoxonase-1 paraoxonase and arylesterase were evaluated in the subjects. Protein expression of paraoxonase-1 was also analysed using western blot method. Paraoxonase-1 L55M (rs854560) polymorphism was determined using tetra-amplification-refractory mutation system polymerase chain reaction. Data was analysed using SPSS® Statistics 20.0. Results: Of the 103 subjects, 50(48.5%) were patients and 53(51.5%) were controls. The overall age range was 50-70 years. The extent of malondialdehyde (p<0.001) and protein carbonyl content (p<0.05) were increased significantly in the patients compared to the controls. Activity of paraoxonase and arylesterase was found decreased (p<0.001) in patients compared to the controls. The prevalence of genotype MM was higher in the patients than the controls(p=0.001). L55M was more pronounced in patients suffering than the controls (p=0.01). Conclusion: The elevated levels of malondialdehyde and cabonylated protein content might be associated with osteoarthritis progression. Decreased serum paraoxonase-1 activity with L55M was the major consequence of oxidative stress in female osteoarthritis patients. Key Words: Osteoarthritis, Oxidative stress, Paraoxonase, Polymorphism.

Triple-action of the standardized antidiabetic polyherbal extract; Synacinn™ through upregulation of GLUT4 and inhibition of DPP(IV), α-amylase, and α-glucosidase activity

INTRODUCTION

Synacinn^™ is a standardized polyherbal supplement for diabetes mellitus which is formulated from Andrographis paniculata, Curcuma xanthorrhiza, Cinnamomum zeylanicum, Eugenia polyantha, and Orthosiphon stamineous.

MATERIALS AND METHODS

This study aimed to elucidate the antidiabetic potential of Synacinn^™ on three specific actions, including 1) the insulin sensitivity and glucose transport on dexamethasone-induced insulin-resistance 3T3-L1 adipocytes, 2) the inhibitory capacity on postprandial enzyme activity (α-amylase and α-glucosidase), and 3) the inhibitory activity of hepatic DPP(IV) enzyme.

RESULTS

Results showed that insulin resistance of 3T3-L1 adipocytes may be developed by prolonging the exposure of 1μg/ml of dexamethasone for >48 hours. The insulinresistance condition was minimized by the treatment of 10 μg/ml of Synacinn^™ which significantly improved the insulin-stimulated glucose utilization by 10.6%. Meanwhile, insulin-stimulated glucose utilization in normal adipocytes was also attenuated by 9.2%. At the cellular level, Synacinn^™ attenuated glucose utilization mainly by upregulating GLUT₄ protein expression by 1.71 fold. Additionally, Synacinn^™ is a potent inhibitor for the activity of α-amylase and α-glucosidase with IC₅₀ of 0.467 mg/mL and 0.245 mg/mL, respectively. Synacinn^™ also controlled the glycemic index through inhibition of hepatic DPP(IV) enzyme with IC₅₀ of 1.11 mg/mL.

CONCLUSION

Results suggested that Synacinn^™ reduced diabetes mellitus through sensitizing the cellular glucose utilization, reducing the postprandial carbohydrate degradation, and inhibiting the hepatic DPP(IV) enzyme function.

Predisposition of SOD1, GPX1, CAT genetic variants and their haplotypes in cataractogenesis of type 2 diabetes mellitus in Pakistan

AIMS

Cataract formation is accelerated by hyperglycemia due to the excessive production of oxidative stress. This study aimed to examine the underlaying role of glutathione peroxidase 1 (GPX1) rs1800668, catalase (CAT) rs1001179 and superoxide dismutase 1 (SOD1) 50 bp Indel promotor region variants in the pathogenesis of cataract in patients with diabetes.

METHODS

A population-based case-control study of n=680 individuals was conducted which comprised of four respective groups: type 2 diabetes mellitus, diabetic cataract, senile cataract patients and controls. Screening of genotypes was performed by allele-specific (AS) and conventional polymerase chain reaction (PCR). Statistical testing was carried out using SPSS© 20.0, MedCal© and SNPStats© software's. Bioinformatics analysis of linkage disequilibrium was done by HaploView© software 7.0.

RESULTS

GPX1 (rs1800668) showed significant association with higher susceptibility of opacification in type 2 diabetes mellitus (χ²=23.0, Adjusted OR=1.63, 95% CI: 1.05-2.49, p<0.001). A protective role was anticipated by CAT variant (rs1001179) for the development of resistance against the pathogenicity of cataract with diabetes (χ² = 107, Adjusted OR=0.17, 95% CI: 0.10-0.29, p<0.001). Linkage disequilibrium (LD) plot of GPX1 and CAT variants revealed that CTC-CTT haplotypes demonstrated the presence of linkage (D'=1.0) and co-inheritance (LOD=13.84) in patients of diabetic cataract.

CONCLUSIONS

GPX1 (rs1800668) variant may serve as an antioxidant biomarker for the assessment of risk for cataract in type 2 diabetes mellitus. GPX1 enzyme owed an antioxidant activity which can reduce the oxidative stress and hence could develop resistance in cataractogenesis. The findings could be beneficial as a potential target to the future pharmacogenomic studies of cataract prevention and eradication in diabetes mellitus.

Prenatal diagnosis of maternal serum from mothers carrying β-thalassemic fetus

BACKGROUND

This study focuses on the discovery of protein biomarkers from the maternal serum of β-thalassemic trait mothers carrying the normal fetus and β-thalassemic major fetus.

METHODS

Serum samples from β-thalassemic trait mothers carrying major (N = 5) and normal fetuses (N = 5) were studied. The IVS1-5 thalassemia mutation was common among β-thalassemic trait mothers who were carrying a homozygous β-thalassemic fetus (IVS1-5/ IVS1-5 mutation) or a normal fetus (no mutation). We employed two-dimensional gel electrophoresis and mass spectrometry analysis to explore differentially expressed maternal serum proteins from thalassemia carrier couples with the same β-thalassemia mutation. Western blotting was performed for one of the identified proteins to validate our data.

RESULTS

Ten proteins were identified in the maternal serum of β-thalassemic trait mothers carrying the β-thalassemic major fetus and normal fetus. Among these, serotransferrin, haptoglobin, α-1 anti-trypsin, apo-lipoprotein A1, and the fibrinogen-β chain were found to be upregulated in mothers carrying major fetuses and are known to be associated with pregnancy-related disorders. The expression of α-1 anti-trypsin was validated through western blotting.

CONCLUSIONS

Proteins identified in the current study from maternal serum are reported to contribute to hereditary disorders. We suggest that these can serve as putative screening markers for non-invasive prenatal diagnosis in β-thalassemic pregnancies.

Antioxidant Activity and Oxidative Stress Status in Maternal Serum of β-thalassemic Mothers Carrying β-thalassemic Major and Normal Fetuses

Objectiveβ-thalassemia is a genetic disorder characterized by reduction or absence of β-globin chain with mutations in both copies (β-thalassemia major) or in one copy (β-thalassemia minor). Pregnancies in β- thalassemic carrier women are considered symptom free but have risk of inheriting β-thalassemic fetuses. Current study was designed to compare oxidative stress and antioxidants status in maternal serum from β-thalassemic minor mothers having β-thalassemic major and normal fetuses. Method: We investigated paraoxonase (PON1) and arylesterase (ARE) activities along with malondialdehyde (MDA) and reactive oxygen species (ROS) in maternal serum of β-thalassemic carrier women. Results: PON1 and ARE activities were found to be significantly decreased, whereas the concentration of MDA and ROS were significantly increased in β-thalassemic minor mothers with β-thalassemic major fetuses. Conclusion: The study concludes that redox imbalance in β-thalassemic trait mothers carrying thalassemic fetuses is higher than in mothers carrying normal fetuses.

Oxidative Stress Induced Cell Cycle Arrest: Potential Role of PRX-2 and GSTP-1 as Therapeutic Targets in Hepatocellular Carcinoma

BACKGROUND

The increasing incidence and mortality rate of HCC is a major concern, especially for developing countries of the world. Hence, extensive research is being carried out in order to explore new approaches for developing successful therapeutic strategies for HCC. The controversial role of oxidative stress in the prognosis and treatment of various diseases such as cancer has become the area of great interest and intrigue for many scientists throughout the world.

OBJECTIVE

We aim to investigate the role of induced oxidative stress on the suppression of HCC Huh-7 cancerous cells as therapeutic approach.

METHODS

Induction of oxidative stress via H2O2 treatment produced cell cytotoxicity in a dose dependent manner and also led to the over expression of GSTP-1 and PRX-2. The expression of GSTP-1 and PRX-2 was compared in HCC Huh-7 treated, untreated cells and normal hepatocytes using immunocytochemistry. Furthermore, the effects of oxidative stress on cell cycle arrest were also studied through flow cytometry.

RESULTS

Our study demonstrated the inhibition of cancer cell proliferation as a result of H2O2 induction by arresting the cell cycle at G2 phase.

CONCLUSION

The induction of oxidative stress could be a potential therapeutic approach for treating HCC in the future. GSTP-1 and PRX-2 can serve as substantial therapeutic targets for the treatment of HCC.

Serum HSP90-Alpha and Oral Squamous Cell Carcinoma : A Prospective Biomarker

AIM

Current study aims to perform differential protein expression analysis of serum samples from Oral squamous cell carcinoma (OSCC) patients and healthy controls in search of potential diagnostic and/or prognostic biomarker(s).

OBJECTIVE

OSCC is diagnosed late, resulting in poor survival and high mortality. Identification of non-invasive prognostic biomarker is of utmost importance for early diagnosis and proper management of the disease; hence we used proteomic approach to identify potential biomarkers from serum.

METHODS

Serum samples (OSCC n=45 and control n=30) were depleted and proteins were separated using 2-D gel electrophoresis followed by identification by mass spectrometric analysis. Gene expression analysis of identified proteins in malignant and normal tissue was also performed to complement proteomics studies.

RESULTS

Among differentially expressed proteins, a noteworthy observation was up regulation of Heat shock protein alpha (HSP90α) from serum of oral cancer patients. We also observed elevated levels of Haptoglobin (HP) along with down regulation of Type II keratin cytoskeletal 1(KRT1) and serum Albumin (ALB) in oral cancer patients. Gene expression studies of identified proteins in malignant and normal tissue revealed a similar pattern with the exception of KRT1. We believe that elevated levels of serum HSP90 alpha might be used as a potential biomarker.

CONCLUSION

Our findings suggest the contribution of HSP90 alpha and other identified proteins in oral pathology as pro/anti apoptotic modulators, thus they are being considered as predictive biomarkers.

Inhibition of USP2 Induces Apoptosis through Down Regulation of Fatty Acid Synthase and Cyclin D1 in Triple Negative Breast Cancer

Background:

Breast cancer is the most occurring cancer in women with high incidence rates both in developed and developing countries. Among different types of breast cancers, Triple Negative Breast Cancer (TNBC) is the most aggressive type as it lacks receptors of Estrogen, Progesterone and Human Epidermal Growth Factor Receptor 2, common diagnostic biomarkers for the disease. Since early detection of TNBC can save thousands of lives, there is a dire need to discover and develop effective and affordable methods for early detection. Different Post Translational Modifications (PTMs) have been proposed as potential biomarker for various clinical conditions. Ubiquitination is a type of PTM involved in the stability and regulation of cellular proteins.

Objective:

It is hypothesized that reticence of ubiquitination may lead to cell death. Current study focuses on the inhibition of Ubiquitin Specific Protease (USP), USP2 using its inhibitor, ML364 in HTB- 132 triple negative breast cancer cell line to induce cell death. The aim of the current study was to evaluate anticancer property of ML364 that might be a promising novel therapeutic agent for TNBC. Furthermore, current investigations focus on USP2 and their focal stabilizing substrates i.e. Fatty acid Synthase (FAS) and Cyclin D1 could be potential prognostic markers for the disease.

Methods:

Quantitative PCR of CyclinD1, USP2, MDM2, and Fatty Acid Synthase (FAS) was performed to identify the deubiquitination effect of ML364 in breast cancer cells, which complemented our results with studies on normal and breast cancerous tissue samples.

Results:

Expression of USP2 and its substrates Cyclin D1and FAS was found to be down regulated in ML364 treated breast cancer cell line whereas higher expression was observed in breast cancer tissue, indicating therapeutic potential of USP2 inhibitor.

Conclusion:

Our findings suggest that USP2, Cyclin D1 and FAS could be used as prognostic marker and therapeutic target for TNBC.

Respiratory health among office workers in Malaysia and endotoxin and (1,3)-β-glucan in office dust

OBJECTIVE: To examine the associations between endotoxin and (1,3)-β-glucan concentrations in office dust and respiratory symptoms and airway inflammation among 695 office workers in Malaysia.METHODS: Health data were collected using a questionnaire, sensitisation testing and measurement of fractional exhaled nitric oxide (FeNO). Indoor temperature, relative air humidity (RH) and carbon dioxide (CO₂) were measured in the offices and settled dust was vacuumed and analysed for endotoxin and (1,3)-β-glucan concentrations. Associations were analysed by two level multiple logistic regression.RESULTS: Overall, 9.6% of the workers had doctor-diagnosed asthma, 15.5% had wheeze, 18.4% had daytime attacks of breathlessness and 25.8% had elevated FeNO (≥25 ppb). The median levels in office dust were 11.3 EU/mg endotoxin and 62.9 ng/g (1,3)-β-glucan. After adjusting for personal and home environment factors, endotoxin concentration in dust was associated with wheeze (P = 0.02) and rhinoconjunctivitis (P = 0.007). The amount of surface dust (P = 0.04) and (1,3)-β-glucan concentration dust (P = 0.03) were associated with elevated FeNO.CONCLUSION: Endotoxin in office dust could be a risk factor for wheeze and rhinoconjunctivitis among office workers in mechanically ventilated offices in a tropical country. The amount of dust and (1,3)-β-glucan (a marker of indoor mould exposure) were associated with Th2 driven airway inflammation.

Therapeutic effect of hydrogen peroxide via altered expression of glutathione S-transferase and peroxiredoxin-2 in hepatocellular carcinoma

BACKGROUND

Hepatocellular carcinoma (HCC) has a high incidence and mortality that epitomizes one of the prominent causes of cancer-related death globally. Novel therapeutic approaches are therefore required. Reactive oxygen species (ROS) are necessary for maintaining cell cycle. Although ROS is involved in HCC progression, hydrogen peroxide (H₂O₂) has anti-proliferative effect on HCC.

METHOD

HCC Huh-7 cells were cultured and incubated with various concentrations of H₂O₂. Paraoxonase activity, levels of malondialdehyde, glutathione and protein oxidation were measured in treated and untreated Huh-7 cells. Furthermore, untreated and treated Huh-7 cells were subjected to two dimensional gel electrophoresis and identified protein spots which were differentially expressed by LC-MS/MS analysis. qRT-PCR was performed to validate the identified proteins.

RESULTS

H₂O₂ depleted glutathione (GSH) with the concomitant up-regulation of GSTP1 and Prx2. H₂O₂ also increased malondialdehyde and protein oxidation, decreased the activity of paraoxonase in Huh-7 cells.

CONCLUSION

H₂O₂ could be used as a novel therapeutic agent that might be beneficial in inducing cell cytotoxicity and hence suppress HCC proliferation.

Identification of Differentially Expressed Proteins from Smokeless Tobacco Addicted Patients Suffering from Oral Squamous Cell Carcinoma

Oral squamous cell carcinoma (OSCC) is the eight most common malignancy worldwide with an incidence rate of 40% in south-east Asia. Lack of effective diagnostic tools at early stage and disease recurrence despite extensive treatments are main reasons for high mortality and low survival rates. The aim of current study was to identify differentially expressed proteins to explore potential candidate biomarkers having diagnostic significance. We performed comparative proteomic analysis of paired protein samples (cancerous buccal mucosa and adjacent normal tissue) from OSCC patients using a combination of two dimensional gel electrophoresis and Mass spectrometric analysis. On the basis of spot intensity, seventeen proteins were found to be consistently differentially expressed among most of the samples which were identified through mass spectrometry. For validation of identified proteins, expression level of stratifin was determined using immuno-histochemistry and Western blot analysis. All identified proteins were analyzed by STRING to explore their interaction. Among uniquely identified proteins in this study, at least two candidate markers (Ig Kappa chain C region and Isoform 2 of fructose bisphosphate aldolase A) were found to be novel with respect to OSCC which can be explored further. Results presented in current study are likely to contribute in understanding the involvement of these molecules in carcinogenesis apart from their plausible role as diagnostic/prognostic markers.

Alendronate and FTI-277 combination as a possible therapeutic approach for hepatocellular carcinoma: An in vitro study

BACKGROUND

An important product of mevalonate pathway is downstream synthesis of isoprenoid units that has long been implicated in development and progression of tumor. It has been speculated that inhibition of protein prenylation might be therapeutically beneficial. The objective of current study was to evaluate antitumor potential of a novel therapeutic combination of mevalonate pathway inhibitors, FTI-277 and alendronate. We also examined differentially expressed proteins in response to treatment using proteomics approach.

METHODS

Huh-7 cells were incubated with different concentrations of FTI-277 alone and in combination with alendronate. Differential protein and gene expression was examined through two dimensional gel electrophoresis and real-time quantitative polymerase chain reaction (qPCR), respectively. Proteins were identified using tandem mass spectrometry analysis.

RESULTS

Treatment of hepatocellular carcinoma (HCC) cell line with FTI-277 alone showed cell death in a time and dose dependent manner while in combination with alendronate, a synergistic apoptotic effect at 24 h was observed. Proteomic studies on the 20 µmol/L FTI-277 and 5 µmol/L alendronate +20 µmol/L FTI-277 treated cells revealed altered expression of different proteins including peroxiredoxin 2 (Prx2), glutathione S transferase 1 (GSTP1), Rho GTPase activating protein (RhoGAP), triosephosphate isomerase (TPI), and heat shock protein 60 (HSP60). Down-regulated expression of Prx2 and GSTP1 in treated cells was also confirmed by real-time qPCR analysis.

CONCLUSIONS

Combined treatment of FTI-277 and alendronate on Huh-7 HCC cells showed cell death suggesting their anticancer potential. Such treatment approaches are likely to offer new therapeutic strategies.

Optically observed multiple inter-chain interactions in polyblend semiconducting polymer nanoparticles

Tunable nanoparticle photoluminescence was observed in nanoparticles formed from a polyblend of F8BT, MEH-PPV, and CN-PPV. This phenomena was attributed to direct and indirect inter-chain interactions between the polymers within each nanoparticle.

Quality of Kelantan drinking water and knowledge, attitude and practice among the population of Pasir Mas, Malaysia

OBJECTIVES

Information about the quality of drinking water, together with analysis of knowledge, attitude and practice (KAP) analysis and health risk assessment (HRA) remain limited. The aims of this study were: (1) to ascertain the level of KAP regarding heavy metal contamination of drinking water in Pasir Mas; (2) to determine the concentration of heavy metals (Al, Cr, Cu, Fe, Ni, Pb, Zn and Cd) in drinking water in Pasir Mas; and (3) to estimate the health risks (non-carcinogenic and carcinogenic) caused by heavy metal exposure through drinking water using hazard quotient and lifetime cancer risk.

METHODS

Information on KAP was collected using a standardized questionnaire. Heavy metal analysis of drinking water samples was performed using graphite furnace atomic absorption spectrophotometry.

RESULTS

The population of Pasir Mas has good knowledge (80%), a less positive attitude (93%) and good practice (81%) towards heavy metal contamination of drinking water. The concentrations of heavy metals analysed in this study were found to be below the permissible limits for drinking water set by the Malaysian Ministry of Health and the World Health Organization. The HRA showed no potential non-carcinogenic and carcinogenic risks from the intake of heavy metal through drinking water.

CONCLUSION

By investigating the quality of drinking water, KAP and HRA, the results of this study will provide authorities with the knowledge and resources to improve the management of drinking water quality in the future.

Effects of 5'-azacytidine and alendronate on a hepatocellular carcinoma cell line: a proteomics perspective

Hepatocellular carcinoma (HCC) is the third leading cause of cancer related deaths around the world. Due to late diagnosis and development of drug resistance in patients suffering from HCC, development of more effective therapeutic strategies is inevitable. The aim of this study was to evaluate the combined apoptotic effect of 5'-Azacytidine (5'-AzaC) and alendronate (ALN) on Huh-7 HCC cell line and to explore differential expression at genomics and proteomics level. Incubation of HCC cell line with 5'-AzaC alone showed cell death in a time and dose dependent manner while in combination with ALN, increased cytotoxicity was observed. Up-regulation of CASP7(Caspase7) and LZTS1 (leucine zipper, putative tumor suppressor 1) and down-regulation of DNMT1(DNA (cytosine-5-)-methyltransferase 1) was noted in treated cells. Proteomic studies on the treated cells revealed altered expression of different proteins including peroxiredoxin 2 (Prx2), Annexin 5 (Anx5), Rho GTPase activating protein (RhoGAP), Nuclear factor-kappa B (NF-kB), tumor necrosis factor alpha-induced protein (TNF), triosephosphate isomerase (TPI), Glutathione S transferase (GSTP1) and Heat shock protein60 (HSP60). Our study demonstrated the cytotoxic effect of 5'-AzaC and ALN drug combination on Huh-7 HCC cells suggesting such combinations may be explored as a possible therapeutic approach. Current study revealed that Huh-7 HCC cells are sensitive to 5'-AzaC and ALN drug combination and such combination approaches could lead to the development of new therapeutic strategies. Furthermore, we also report the expression of Anx5 exclusively in untreated cancerous cell line indicating the possibility of being used as a potential therapeutic target and biomarker.

Knowledge, attitude and perception of second-hand smoke and factors promoting smoking in Malaysian adolescents

OBJECTIVE

To identify the relationship between knowledge, attitude and perception regarding environmental tobacco smoke (ETS) and smoking among Malaysian adolescents living in states with complete or partial smoke-free legislation (SFL).

METHODS

A total of 898 respondents aged 13-14 years were randomly selected from 21 secondary schools. The Malay version of the modified Global Youth Tobacco Survey questionnaire was used. Hierarchical logistic regression was performed in examining predictors of smoking attempt among adolescents.

RESULTS

Participants exposed to ETS >5 h/day were more likely to have smoked compared to those exposed to ETS <1 h/day (OR 4.1, 95%CI 1.03-16.0). Living in a state with partial SFL was associated with a two-fold increase in self-reported smoking attempts (OR 1.95, 95%CI 1.10-3.43) compared to living in a state with complete SFL. Negative attitudes and perceptions towards smoking and ETS exposure were linked to lower smoking attempts in states with complete SFL.

CONCLUSIONS

Adolescents with limited ETS exposure who lived in a state with complete SFL were less likely to attempt smoking compared to those exposed more regularly to ETS and living in a state with partial SFL. Preventing adolescents from becoming smokers is the key to reducing national prevalence rates in smoking. There is a need to implement comprehensive smoke-free legislation nationally across Malaysia.

Measurement of serum paraoxonase activity and MDA concentrations in patients suffering with oral squamous cell carcinoma

BACKGROUND

Oxidative stress is associated with many diseases including cancer. Oral squamous cell carcinoma (OSCC) is a prevalent cancer involving oral cavity. We evaluate the activity of paraoxonase 1 (PON1) in serum samples of subjects suffering from OSCC along with malondialdehyde (MDA) levels, a marker for oxidative stress. Antioxidant status in OSCC may reflect the role of oxidative imbalance in the disease.

METHODS

Forty-five patients suffering with OSCC and 30 healthy controls were selected for the study. Serum paraoxonase (PON) and arylesterase (ARE) activities were measured in subjects suffering from OSCC and their healthy counterparts. To examine the status of lipid peroxidation, MDA concentrations were estimated and a correlation was determined between PON activities and MDA concentrations. MDA expression in cancer and normal adjacent tissue was studied through immunohistochemical (IHC) analysis. Total reactive oxygen species (ROS) level was determined in serum from normal and diseased subjects. Our results revealed that both PON and ARE activities of PON1 were significantly decreased in OSCC patients. Serum MDA concentrations were inversely correlated to PON activity. Immunohistochemical analysis showed a higher expression of MDA in cancerous tissue. Total ROS levels were found to be significantly elevated in cancer subjects.

CONCLUSIONS

Along with other antioxidants, PON levels may act as an indicator of oxidative stress in cancer.

Osmotic stress induced oxidative damage: possible mechanism of cataract formation in diabetes

Chronic hyperglycemia causes increased level of reactive oxygen species which is thought to be involved in the pathogenesis of diabetes associated complications including cataract. In diabetic cataractous lens, over production of free radicals and decreased capacity of antioxidant defense system are the major contributors to oxidative damage by polyol pathway and advanced glycation end products. The current study focused on analysis of factors associated with osmotic imbalance and oxidative stress in aging and diabetic human cataractous lenses. We examined activities of polyol pathway enzymes, G6PD and glutathione system in lenses from subjects suffering from cataract due to aging and diabetes. We observed elevated activities of aldose reductase and sorbitol dehydrogenase while G6PD and glutathione system enzyme activities were found to be lower in cataractous subjects suffering from diabetes. The findings from the current study support the premise that osmotic imbalance, AGEs formation and oxidative stress contribute synergistically to the development of lens opacity in hyperglycemia.

Advanced glycation end products in diabetic and non-diabetic human subjects suffering from cataract

Advanced glycation end products (AGEs) play a pivotal role in loss of lens transparency, i.e., cataract. AGEs formation occurs as a result of sequential glycation and oxidation reaction between reducing sugars and protein. AGEs production takes place throughout the normal aging process but its accumulation is found to be more rapid in diabetic patients. In this study, we quantified AGEs and N-(carboxyethyl) lysine (CEL) in human cataractous lenses from non-diabetic (n=50) and diabetic patients (n=50) using ELISA. We observed significantly higher (p<0.001) levels of lens AGEs and CEL in diabetic patients with cataract as compared with their respective controls. The presence of AGEs and CEL was also determined by western blotting and immuno-histochemical analysis. Furthermore, isolated β-crystallin from cataractous lenses of non-diabetic and diabetic patients was incubated with different sugars to evaluate the extent of glycation in a time dependent manner. Our data indicated more pronounced glycation in patients suffering from diabetes as compared to non-diabetics subjects demonstrating the need to focus on developing normoglycemic approaches. Such studies may provide an insight in developing therapeutic strategies and may have clinical implications.

Expression and activity of paraoxonase 1 in human cataractous lens tissue

Paraoxonase 1 (PON1) is a high-density lipoprotein-associated enzyme that is believed to be involved in the protection against oxidative stress. There is evidence that paraoxonase activity is reduced in patients with diabetes and cataract. In the current study, we analyzed mRNA expression of PON1 as well as other members of the paraoxonase family, PON2 and PON3, in human cataractous lens samples. Our results indicate that only PON1 is expressed at the gene and protein levels in human lens tissues. We quantified MDA levels and measured PON1 (paraoxonase/arylesterase) enzymatic activities in subjects suffering from cataract due to aging and diabetes. Decreased PON1 activity was more pronounced in diabetic patients (p< 0.001) compared to senile subjects, which may be due to glycation and increased oxidative insult. To examine the structural alterations that occur in response to glycation, we constructed a three-dimensional model of PON1 and its glycated variant. Glycation at Lys70 and Lys75 is predicted to cause hindrance in binding of substrate to the active site of the enzyme.

Relationship between blood lead concentration and nutritional status among Malay primary school children in Kuala Lumpur, Malaysia

A cross-sectional study was conducted to identify the relationship between blood lead concentration and nutritional status among primary school children in Kuala Lumpur. A total of 225 Malay students, 113 male and 112 female, aged 6.3 to 9.8 were selected through a stratified random sampling method. The random blood samples were collected and blood lead concentration was measured by a Graphite Furnace Atomic Absorption Spectrophotometer. The nutrient intake was determined by the 24-hour Dietary Recall method and Food Frequency Questionnaire. An anthropometric assessment was reported according to growth indices (z-scores of weight-for-age, height-for-age, and weight-for-height). The mean blood lead concentration was low (3.4 +/- 1.91 ug/dL) and was significantly different between gender. Only 14.7% of the respondents fulfilled the daily energy requirement. The protein and iron intakes were adequate for a majority of the children. However, 34.7% of the total children showed inadequate intake of calcium. The energy, protein, fat and carbohydrate intakes were significantly different by gender, that is, males had better intake than females. Majority of respondents had normal mean z-score of growth indices. Ten percent of the respondents were underweight, 2.8% wasted and 5.4% stunted. Multiple linear regression showed inverse significant relationships between blood lead concentration with children's age (beta = -0.647, p < 0.001) and per capita income (beta = -0.001, p = 0.018). There were inverse significant relationships between blood lead concentration with children's age (beta = -0.877, p = 0.001) and calcium intake (beta = -0.011, p = 0.014) and positive significant relationship with weight-for-height (beta = 0.326, p = 0.041) among those with inadequate calcium intake. Among children with inadequate energy intake, children's age (beta = -0.621, p < 0.001), per capita income (beta = -0.001, p = 0.025) and protein intake (beta = -0.019, p = 0.027) were inversely and significantly related with blood lead concentration. In conclusion, nutritional status might affect the children's absorption of lead and further investigation is required for confirmation.

Antioxidant markers in human senile and diabetic cataractous lenses

OBJECTIVE

To determine the role of free radicals and antioxidant enzymes in patients suffering from cataract due to aging and diabetes.

DESIGN

Experimental study.

PLACE AND DURATION OF STUDY

Department of Biochemistry, University of Karachi from December 2004 to May 2005.

PATIENTS AND METHODS

The study was conducted on 80 cataract patients. Lens and plasma samples from senile and diabetic subjects suffering from cataract were analyzed and activity of Cu, Zn-superoxide dismutase (Cu, Zn-SOD) was measured using xanthine oxidase system. Catalase (CAT) activity was estimated. Levels of malondialdehyde (MDA) was measured by thiobarbituric acid reaction. Student's t- test was employed for analysis of results.

RESULTS

Significant difference (p<0.001) was found in activity of Cu, Zn-SOD in cataract lenses from diabetic patients as compared to senile subjects, CAT activities was also lower (p<0.001) in lenses from diabetic cataract patients when compared to lenses from senile cataractous subjects. Lens MDA levels were significantly higher (p<0.001) in cataract lenses from diabetic patients than in senile subjects. Plasma MDA levels were lowest (p<0.001) in controls as compared to senile and diabetic cataractous patients.

CONCLUSION

Results of present study suggest that increased production of high levels of free oxygen species is linked to glucose oxidation and non-enzymatic glycation of proteins. Furthermore, elevated glucose levels might be involved in the insufficiency of antioxidant enzymatic activity and in the progression of lipid peroxidation.

Assessment of paraoxonase activity and lipid peroxidation levels in diabetic and senile subjects suffering from cataract

OBJECTIVES

The purpose of this study was to evaluate antioxidant effect of paraoxonase 1 activity and malondialdehyde (MDA) levels as a marker of oxidative stress in patients suffering from cataract due to diabetes and aging.

DESIGN AND METHODS

One hundred cataract patients (senile and diabetic) and age- and sex-matched controls were studied. Paraoxonase 1 and arylesterase activities in plasma samples were measured using paraoxon and phenylacetate as substrates, respectively. The magnitude of lipid peroxidation was established by measuring plasma MDA and oxidized low-density lipoprotein (ox LDL) levels. One-way ANOVA was employed for analysis of results.

RESULTS

We observed significantly lower plasma paraoxonase and arylesterase activities in senile and diabetic cataractous patients as compared to respective controls (p<0.001). Plasma MDA and ox LDL levels were found to be higher in patients suffering from cataract (p<0.001).

CONCLUSIONS

The results of present study suggest that the observed decrease in PON1 activity may be due to increase in oxidative stress. It can be concluded that lower paraoxonase activity could contribute to the higher risk of cataract formation.

Blood lead levels of urban and rural Malaysian primary school children

The objective of this article is to study the influence of exposure and socio-economic variables on the blood lead level of Malaysian school children. Data on respirable lead and blood lead of 346 school children were obtained from Kuala Lumpur (urban), Kemaman (semi-urban) and Setiu (rural). Respirable lead and blood lead were highest for Kuala Lumpur (95 ng/m3 and 5.26 micrograms/dL) followed by Kemaman (27 ng/m3 and 2.81 micrograms/dL) and Setiu (15 ng/m3 and 2.49 micrograms/dL), and the differences were statistically significant. The percentage of school children with excessive blood lead of 10 micrograms/dL or greater was 6.36% overall, and highest for Kuala Lumpur (11.73%). Regression analyses show that urban children are at higher risk of exhibiting excessive blood lead levels. Kuala Lumpur's school children have a 25 times greater risk of having excessive blood lead levels when compared to Kemaman's and Setiu's school children. Respirable and blood lead were correlated (r = 0.999, p = 0.021). Urban school children acquire higher blood lead levels than their rural and semi-urban counterparts, even after controlling for age, sex, parents' education and income levels. In conclusion, it is time that lead in the Malaysian environment and population be monitored closely, especially its temporal and spatial variability. Only then can a comprehensive preventive strategy be implemented.

Interindividual variation in circulating zinc concentrations among healthy adult men and women

Circulating zinc concentrations were measured in 73 healthy adult males and females 19-52 years of age who were volunteers for eight different metabolic studies at the University of California, Berkeley. The interindividual variation in the eight studies varied from 5 to 20%; the global coefficient of variation for all studies was 12 +/- 7% (mean +/- SD). The analysis of a reference plasma sample on six different days showed a mean coefficient of variation of 3.8%. Thus, only a small portion of the intraindividual variation is due to day-to-day analytical differences. There was no relationship between circulating zinc concentrations and age, height, or body mass index. Nor were there any significant differences due to gender. Information regarding dietary zinc and protein intakes was available from three-day weighed food intake records from 44 of the subjects. Plasma zinc concentrations were unrelated to the intake of either zinc or protein in those subjects. The results of this study show that the impact of age, gender, body size and dietary zinc or protein on circulating zinc concentrations are too small to be detected in the presence of the analytical and endogenous factors that influence plasma/serum zinc concentrations. Also, within a population of healthy adults, circulating zinc concentrations may vary by as much as 15%.

Resonant photoemission from complex cuprates and nickelates

Synchrotron-excited resonant-photoemission measurements at rare-earth 4d --> 4f and transition-metal 3p --> 3d thresholds have been carried out using a variety of complex cuprates and nickelates on stations 6.1 (grazing-incidence monochromator) and 6.2 (toroidal-grating monochromator) at the SRS CLRC Daresbury Laboratory. The systems studied are Nd(2)Ni(1 - x)Cu(x)O(4), La(2 - x)Sr(x)Ni(1- y)Fe(y)O(4 + delta) and Bi(2)Sr(2)Ca(1 - x)Y(x)Cu(2)O(8 + delta). A combination of EDC and constant-initial-state data is used to examine the 4f and 3d contributions to the valence-band density of states and their binding-energy positions relative to the Fermi energy. This allows the study of the valence states of the transition-metal ions and their modulation on doping. For La(2 - x)Sr(x)Ni(1 - y)Fe(y)O(4 + delta), this approach is used to infer a valence state of >/= 3.0 for Fe. In the case of Bi(2)Sr(2)Ca(1 - x)Y(x)Cu(2)O(8 + delta), the effect of Cu valence modulation on the 3p resonance is observed as x is varied. This is discussed in the light of controversy surrounding shifts in core-level photoemission with doping for this system.

Evaluation of trace trace elements iron, zinc, copper and lead in the diet of female university students

Food consumption of 50 female students in Universiti Kebangsaan Malaysia was recorded for 7 days. Foods and drinks most frequently consumed were selected for analysis of iron, zinc, copper and lead content. The mean daily intakes of energy, protein, carbohydrate and fat among the students are 6.5±1.4 MJ (1550±335 kcal), 59.8±18.5g, 227.1±54.6 g and 46.0±11.5 g respectively. This diet contributed 19.6-6.4 mg Fe, 7.0-2.0 mg Zn and 1.6-0.6 mg Cu per day which were lower than the Malaysian RDA for Fe and US RDA for Zn, while Cu is within the recommended range. The main sources of these minerals in the student's diet were rice, rice products, meat and animal products. Lead concentration in the diet (134±77 ug/day) is below the acceptable daily intake (ADI) value suggested by Codex Alimentarius Commission (1984). This study indicated concern regarding the low intake of the essential trace elements on long term basis among the students.

Energy intake and activity pattern during pregnancy in relation to infant birth weight

The study was designed to determine if the activity pattern of pregnancy women on an intake of energy lower than that recommended will affect fetal growth. Subjects who volunteered were either attending public or private hospitals. Pregnant women in the "private" group were significantly older (p < 0.001) weighed somewhat less and significantly taller (p < 0.001) when compared to the "public" group. Differences in energy intake during the second and third trimesters between the "public" and "private" groups were small; 1608 +/- 334, 1726 +/- 271 kcal and 1627 +/- 367, 1778 +/- 260 kcal, respectively. However, daily activity patterns revealed that the "public" group was more active as reflected by the higher energy expenditure of 1412 +/- 74 kcal and 1578 +/- kcal during the second and third trimesters respectively. There was a significant difference (p < 0.01) in birth weight between the "public" and "private" groups; 2951 +/- 377 g and 3173 +/- 357 g respectively. This study indicates that energy intakes lower than recommended and sedentary lifestyles have no direct influence on birth weights of babies.