Enhancing a clenbuterol immunosensor based on poly(3,4-ethylenedioxythiophene)/multi-walled carbon nanotube performance using response surface methodology

Clenbuterol (CLB) is an illegal antibiotic for livestock, which is misused as a growth promoter drug. In this study, an immunosensor modified with poly(3,4-ethylenedioxythiophene) (PEDOT), multi-walled carbon nanotubes (MWCNT) and anti-clenbuterol antibody (Ab) was developed for the detection of CLB. A screen-printed carbon electrode (SPCE) was modified with PEDOT/MWCNT as a sensor platform before immobilizing Ab for specific CLB binding through a competitive-type immunoassay. Free CLB in the sample solution competed with clenbuterol-horseradish peroxide (CLB–HRP) to bind with Ab. A high current signal was obtained after optimization of the electrochemical immunoassay conditions (pH, incubation temperature, antigen (Ag) incubation time and % blocking) using the response surface methodology/central composite design (RSM/CCD). The developed immunosensor is highly reproducible and sensitive with good storage stability, which are necessary for practical application. In real sample application, this immunosensor produces comparable results with liquid chromatography-mass spectrometry; thus, it is useful for CLB screening and monitoring in real meat samples.

A clenbuterol immunosensor was developed with a poly(3,4-ethylenedioxythiophene)/multi-walled carbon nanotube-modified screen-printed carbon electrode and optimized using response surface methodology.     

Recombinant expression of Toxocara canis excretory-secretory antigen TES-120 in Escherichia coli

The gene encoding the excretory-secretory antigen TES-120 of dog ascarid worm Toxocara canis was cloned into the bacterium Escherichia coli. The specificity of the recombinant TES-120 antigen produced by the bacterium was investigated. A total of 45 human serum samples from patients infected with differenthelminthes and protozoa, including 8 cases of toxocariasis, were tested against the recombinant antigens in immunoblot assays. The results from the assays revealed that the recombinant TES-120 antigen reacted with sera from toxocariasis patients only. This highly specific recombinant TES-120 antigen can potentially be used for the development of an inexpensive serodiagnostic assay for human toxocariasis.     

Immunity in young adult survivors of childhood leukemia is similar to the elderly rather than age‐matched controls: Role of cytomegalovirus

Many treatment complications that occur late in childhood cancer survivors resemble age‐related comorbidities observed in the elderly. An immune phenotype characterized by increased immune activation, systemic inflammation, and accumulation of late‐differentiated memory CD57⁺CD28^? T cells has been associated with comorbidities in the elderly. Here, we explored if this phenotype was present in young adult leukemia survivors following an average of 19 years from chemotherapy and/or radiotherapy completion, and compared this with that in age‐matched controls. We found that markers of systemic inflammation—IL‐6 and human C‐reactive protein and immune activation—CD38 and HLA‐DR on T cells, soluble CD (sCD)163 from monocytes and macrophages—were increased in survivors compared to controls. T‐cell responses specific to cytomegalovirus (CMV) were also increased in survivors compared to controls while CMV IgG levels in survivors were comparable to levels measured in the elderly (>50years) and correlated with IL‐6, human C‐reactive protein, sCD163, and CD57⁺CD28^? memory T cells. Immune activation and inflammation markers correlated poorly with prior chemotherapy and radiotherapy exposure. These data suggest that CMV infection/reactivation is strongly correlated with the immunological phenotype seen in young childhood leukemia survivors and these changes may be associated with the early onset of age‐related comorbidities in this group.     

Review on human toxoplasmosis in Malaysia: the past, present and prospective future

We reviewed various studies regarding human toxoplasmosis in Malaysia. They showed a varying prevalence of specific Toxoplasma antibodies among the Malaysian population. The Malays have shown the highest seroprevalence of toxoplasmosis, by most studies, when compared to other races. Demographic profiles have shown that Toxoplasma seropositivity is higher in males than females, lower in people with higher incomes, higher in the unemployed and tends to increase with age. In general, the route of transmission, such as contact with a cat, consumption of undercooked meat and blood transfusion were shown to have no significant association with Toxoplasma seropositivity (p > 0.05). The immune status (CD4 cell count < 200 cell/mm3) was strongly associated with toxoplasmic encephalitis (p < 0.05).     

Microfilaria in hydrocele fluid cytology

Filariasis, a parasitic infection endemic in parts of India, Myanmar, islands of the South Pacific, West and East Africa and Saudi Arabia can be diagnosed from various types of cytopathological specimens. This case documents the detection of filarial infection from hydrocele fluid cytology in a 30-year-old Myanmar migrant worker in Malaysia.     

Evaluation of NMU-Induced Breast Cancer Treated with Sirolimus and Sunitinib on Breast Cancer Growth

Objective: To analyze the effect of sirolimus and sunitinib in blocking the tumor growth and to evaluate the expressions of estrogen receptor (ER), progesterone receptor (PgR), and human epidermal growth factor receptor-2 (HER2/neu) after treated with sirolimus and sunitinib. Methods: Thirty-two female Sprague Dawley rats at age 21-days old were administered intraperitoneally with N-Methyl-N-Nitroso Urea (NMU), dosed at 70mg/kg body weight. The rats were divided into 4 groups; Group 1 (Control, n=8), Group 2 (Sirolimus, n=8), Group 3 (Sunitinib, n=8) and Group 4 (Sirolimus+Sunitinib, n=8), being treated twice when the tumor reached the size of 14.5±0.5 mm and subsequently sacrificed after 5 days. The protein expressions of ER, PgR and HER2/neu of the tumor tissues were evaluated by using immunohistochemistry analysis. Results: Treatment with sirolimus alone lowered expressions of ER and PgR of breast cancer and reduced tumor size. There was no significant difference of ER and PgR expressions between control and sunitinib treated tumor. Sunitinib treated tumors reduce in diameter after the first treatment, however the diameter increases after the second treatment. Histologically, sunitinib treated tumor did not show any aggressive invasive carcinoma of no special type (NST) histological subtypes. In addition, all NMU-induced tumors are HER2/neu-negative scoring. Conclusion: Sirolimus is neither synergistic nor additive with sunitinib for breast cancer treatment.     

Toxocara seroprevalence and childhood asthma among Malaysian children

BACKGROUND: The larva of Toxocara spp., a common animal roundworm, may infect non-compatible hosts, causing a profound immunological reaction with marked eosinophil and IgE responses, not unlike in atopy. In this study, we determined the seroprevalence of Toxocara exposure in 66 asthmatic and 58 non-asthmatic children. METHODS: Exposure to Toxocara was determined by examining the serum samples of the children for specific IgG antibodies to L2 Toxocara larvae, using a commercially available diagnostic kit. RESULTS: There was no significant difference in the mean age, sex, social class, residence type and presence of domestic pets at home between the two children groups. Children with bronchial asthma were observed to have higher Toxocara seropositivity than that of the non-asthmatic controls (21.2 vs 8.6%, P=0.047). CONCLUSION: The observed relationship between exposure to Toxocara infection and bronchial asthma in Malaysian children warrants further evaluation. An understanding of any possible contribution to the pathogenesis of childhood asthma provides a potential avenue for prevention.     

Defining metabolic syndrome and factors associated with metabolic syndrome in a poly-pharmaceutical population

Objectives: Metabolic Syndrome (METs) definitions vary and diagnosis takes into account consumption of medications commonly prescribed for conditions defining METs. This paper evaluates the potential differences in population characteristics using two different methods of defining METs, with and without the adjustment of the effects of pharmacotherapy on biochemical and blood pressure (BP) measurements

Methods: This was a cross-sectional study utilizing the Malaysian Elders Longitudinal Research (MELoR) cohort comprising urban community-dwellers aged ≥55 years. Participants were interviewed using a structured questionnaire during home visits where medications were reviewed. Health impacts assessed included heart disease, stroke, body mass index (BMI), peptic ulcers, arthritis, and number of medications and comorbidities. Risk factors and health impacts associated with METs were determined by Poisson multivariate regression models using a binary and count dependent variables.

Results: A total of 891 participants with a mean (SD) age of 68.6 (7.3) years were included. The prevalence of METs vary from 52.7% to 35.1% depending upon the definition used. The risk factors associated with METs were increasing age, ethnicity, lower education levels, BMI, stroke and medication use. Male gender was considered a risk factor following modification for medication usage using a count model. The drug-modified model removed marginal candidates prescribed medications used for specific conditions which defined METs who did not meet the criteria once their BP or biochemical parameters were modified for the effects of medication-use.

Conclusion: The IDF definition for METs that makes allowance for treatment for each specific condition can lead to an overestimation in the prevalence of METs in population studies. Not including those medicated with normal results conversely underestimates the prevalence of METs. We have therefore proposed adjustments to BP and lipid measurements based on pooled mean effects from published systematic reviews to mitigate bias in future research on prevalence of METs.