Urografi intravena (IVU) dan tomografi berkomputer helikal tanpa kontras (UHCT) urografi adalah dua prosedur utama yang akan dijalankan semasa penyiasatan radiologi bagi pengesanan urolitiasis (batu karang) pada sistem genitourinari. Dedahan terhadap sinaran radiasi merupakan faktor kebimbangan utama dalam kedua-dua prosedur. Oleh itu, satu kajian perbandingan dos sinaran telah dijalankan antara prosedur IVU dan UHCT urografi di samping menentukan faktor dedahan optimum bagi kedua-dua prosedur tersebut. Kajian ini telah dijalankan ke atas fantom antropomorfik seluruh tubuh mengikut protokol sebenar bagi prosedur UHCT urografi dan penghasilan radiografi bersiri berserta dengan pemberian media berkontras bagi prosedur IVU. Sebanyak tiga parameter dedahan voltan tiub digunakan iaitu 75 kVp, 80 kVp dan 85 kVp bagi prosedur IVU dan 100 kVp, 120 kVp dan 140 kVp bagi prosedur UHCT urografi . Hasil dos sinaran bagi prosedur IVU yang diperolehi adalah 1.40 mSv, 2.10 mSv dan 2.79 mSv bagi 75 kVp, 80 kVp dan 85 kVp. Manakala bagi prosedur UHCT urografi , sebanyak 0.76 mSv, 1.32 mSv dan 1.82 mSv dos sinaran direkodkan bagi 100 kVp, 120 kVp dan 140 kVp. Hasil kualiti imej optimum adalah menggunakan dedahan sebanyak 85 kVp bagi prosedur IVU dan 120 kVp bagi prosedur UHCT urografi . Kesimpulannya, walaupun tidak terdapat perbezaan signifi kan, dos sinaran yang terhasil daripada prosedur IVU adalah kekal lebih tinggi daripada prosedur UHCT urografi .
Urografi intravena (IVU) dan tomografi berkomputer helikal tanpa kontras (UHCT) urografi adalah dua prosedur utama
yang akan dijalankan semasa kajian radiologi bagi pengesanan urolitiasis (batu karang) pada sistem genitourinari.
Dedahan terhadap sinaran radiasi merupakan faktor kebimbangan utama dalam kedua-dua prosedur. Oleh itu, satu
kajian perbandingan dos sinaran telah dijalankan antara prosedur IVU dan UHCT urografi di samping menentukan faktor
dedahan optimum bagi kedua-dua prosedur tersebut. Kajian ini telah dijalankan ke atas fantom antropomorfi seluruh
tubuh mengikut protokol sebenar bagi prosedur UHCT urografi dan penghasilan radiografi bersiri beserta dengan
pemberian media berkontras bagi prosedur IVU. Sebanyak tiga parameter dedahan voltan tiub digunakan iaitu 75, 80
dan 85 kVp bagi prosedur IVU dan 100, 120 dan 140 kVp bagi prosedur UHCT urografi. Hasil dos sinaran bagi prosedur
IVU yang diperoleh adalah 1.40, 2.10 dan 2.79 mSv bagi 75, 80 dan 85 kVp. Manakala bagi prosedur UHCT urografi,
sebanyak 0.76, 1.32 dan 1.82 mSv dos sinaran direkodkan bagi 100, 120 dan 140 kVp. Hasil kualiti imej optimum adalah
menggunakan dedahan sebanyak 85 kVp bagi prosedur IVU dan 120 kVp bagi prosedur UHCT urografi. Kesimpulannya,
walaupun tidak terdapat perbezaan signifikan, dos sinaran yang terhasil daripada prosedur IVU adalah tekal lebih tinggi
daripada prosedur UHCT urografi.
Spermine (SPM) is considered a biomarker for prostate cancer and detecting it becomes highly challenging due to its electro- and optical-inactive nature. SPM has a tendency to interact with groups such as phosphates and sulfides to form macrocyclic arrangements known as nuclear aggregates of polyamines. Using this tendency, an electrochemical sensor has been developed using a polysulfide (PS) modified Au electrode (PS@Au electrode). PS has been synthesized from elemental sulfur by hydrothermal method and characterized using UV-Vis, fluorescence, FTIR, SEM, and XPS analyses. The PS@Au electrode was employed for electrochemical sensing of SPM. In the presence of SPM, a decrease in gold oxide reduction current was noted which is proportional to the concentration of SPM. The decrease in gold oxide reduction (0.5 V) current was attributed to the complexing nature of SPM-PS at the electrode interface. The reason for the decrease in current has been substantiated using XRF, XPS, and spectroelectrochemical studies. Under the optimized conditions, the PS@Au electrode exhibited a linear range of 1.55-250 µM with LOD of 0.511 ± 0.02 µM (3σ). The electrochemical strategy for SPM sensing exhibited better selectivity even in the presence of possible interferents. The selectivity stems from the selective interaction of SPM with PS on the Au electrode surface; the tested amino acids, and other molecules do not complex with PS and hence they could not interfere. The PS@Au electrode has been subjected to the determination of SPM in artificial urine samples and exhibited outstanding performance in the synthetic sample.
A rapid and green analytical method based on capillary electrophoresis with capacitively coupled contactless conductivity detection (C⁴D) for the determination of eight environmental pollutants, the biogenic amines (putrescine, cadaverine, spermidine, spermine, tyramine, 2-phenylamine, histamine and tryptamine), is described. The separation was achieved under normal polarity mode at 24 °C and 25 kV with a hydrodynamic injection (50 mbar for 5 s) and using a bare fused-silica capillary (95 cm length × 50 µm i.d.) (detection length of 10.5 cm from the outlet end of the capillary). The optimized background electrolyte consisted of 400 mM malic acid. C⁴D parameters were set at a fixed amplitude (50 V) and frequency (600 kHz). Under the optimum conditions, the method exhibited good linearity over the range of 1.0⁻100 µg mL−1 (R² ≥ 0.981). The limits of detection based on signal to noise (S/N) ratios of 3 and 10 were ≤0.029 µg mL−1. The method was used for the determination of seawater samples that were spiked with biogenic amines. Good recoveries (77⁻93%) were found.
Rice which belongs to the grass family is vulnerable to water stress. As water resources get limited, the productivity of rice is affected especially in granaries located at drought prone areas. It would be even worse in granaries located in drought prone areas such as KADA that receives the lowest rainfall in Malaysia. Spermine (SPM), a polyamine compound that is found ubiquitiosly in plants is involved in adaptation of biotic and abiotic stresses. The effect of SPM on growth,grain filling and yield of rice at three main granaries namely, IADA BLS, MADA and KADA representing unlimited water, limited water and water stress conditions respectively, were tested during the main season. Additinally, the growth enhancer was also tested during off season at KADA. Spermine increased plant height, number of tillers per hill and chlorophyll content in all three granaries. Application of SPM improved yield by 38, 29 and 20% in MADA, KADA and IADA BLS, respectively. Harvest index showed 2.6, 6 and 16% increases at IADA BLS, KADA and MADA, respectively in SPM treated plants as compared to untreated. Except for KADA which showed a reduction in yield at 2.54 tha-1, SPM improved yield at MADA, 7.21 tha-1 and IADA BLS, 9.13 tha-1 as compared to the average yield at these respective granaries. In the second trial, SPM increased the yield to 7.0 and 6.4 tha-1 during main and off seasons, respectively, indicating that it was significantly higher than control and the average yield reported by KADA. The yield of SPM treatments improved by 25 and 33% with an increment of farmer's income at main and off seasons, respectively. Stomatal width was significantly higher than control at 11.89 µm. In conclusion, irrespective of the tested granaries and rice variety, spermine mediated plots displayed increment in grain yield.
Regeneration of plantlets from shoot apex-derived callus and "calloid" cultures of a local taro [Colocasia esculenta var. antiquorum cv. Keladi Birah] cultivar, was expedited by treatment with high levels of spermine. The total time taken, from culture of primary shoot apices on modified Linsmaier and Skoog medium supplemented with trichlorophenoxyacetic acid and kinetin, to complete plantlet regeneration, was reduced by 2-16 weeks, when the callus and "calloid" cultures were treated with 0.01, 0.1 and 1 mM spermine. Furthermore, the number of plantlets produced per gram callus increased from 25 to 55. On media supplemented with arginine and ornithine, no callus was initiated from expiants and no plantlets differentiated from pre-established callus.
In vitro growth and multiplication of taro [Colocasia esculenta var. antiquorum cv. Keladi Birah] was improved considerably, when primary shoot apices were cultured on two modifications of Linsmaier and Skoog [1965] medium, containing 5.5 mg 1(-1) naphthaleneacetic acid and 0.2 mg 1(-1) kinetin or 1.85 mg 1(-1) naphthaleneacetic acid and 2 mg 1(-1) kinetin and supplemented with 10(-4) or 10(-3) mol·1(-1) of polyamine spermine or either of the precursors of polyamine putrescine-arginine and ornithine. Plantlets were regenerated directly from primary shoot apices, axillary buds and protocorm-like bodies [PLB]. Frequency of plantlet regeneration, rate of development and growth in height of main plantlets were enhanced by the addition of arginine and ornithine to the media. Secondary plantlet formation from axillary buds and PLB were promoted by spermine and arginine respectively.
Leukemic cells are hard-to-transfect cell lines. Many transfection reagents which can provide high gene transfer efficiency in common adherent cell lines are not effective to transfect established blood cell lines or primary leukemic cells. This study aims to examine a new class of cationic polymer non-viral vector, PEGylated-dextran-spermine (PEG-D-SPM), to determine its ability to transfect the leukemic cells. Here, the optimal conditions of the complex preparation (PEG-D-SPM/plasmid DNA (pDNA)) were examined. Different weight-mixing (w/w) ratios of PEG-D-SPM/pDNA complex were prepared to obtain an ideal mixing ratio to protect encapsulated pDNA from DNase degradation and to determine the optimal transfection efficiency of the complex. Strong complexation between polymer and pDNA in agarose gel electrophoresis and protection of pDNA from DNase were detected at ratios from 25 to 15. Highest gene expression was detected at w/w ratio of 18 in HL60 and K562 cells. However, gene expression from both leukemic cell lines was lower than the control MCF-7 cells. The cytotoxicity of PEG-D-SPM/pDNA complex at the most optimal mixing ratios was tested in HL60 and K562 cells using MTS assay and the results showed that the PEG-D-SPM/pDNA complex had no cytotoxic effect on these cell lines. Spherical shape and nano-nature of PEG-D-SPM/pDNA complex at ratio 18 was observed using transmission electron microscopy. As PEG-D-SPM showed modest transfection efficiency in the leukemic cell lines, we conclude that further work is needed to improve the delivery efficiency of the PEG-D-SPM.
Biological amines are nitrogenous compounds that occur naturally in wide variety of food. Histamine, putrescine, cadavarine, tyramine, spermine, spermidine, tryptamine and β-phenylethylamine are the biogenic amines that are normally present in foods. Although the biogenic amines play some important physiological functions but high level of amines can cause toxicological effects. High amount of amines can be produced by bacteria during amino acids decarboxylation and have been identified as one of the important agent causing seafood intoxication. Temperature is the major factor for controlling the biogenic amines formation in food. The effects of other alternatives are also discussed including salting, packaging, irradiation, high pressure processing and the use of starter culture. A variety of techniques can be combined together to control the microbial growth and enzyme activity during processing and storage for better shelf life extension and food safety.
A novel cationic polymer, dextran-spermine (D-SPM), has been found to mediate gene expression in a wide variety of cell lines and in vivo through systemic delivery. Here, we extended the observations by determining the optimal conditions for gene expression of D-SPM/plasmid DNA (D-SPM/pDNA) in cell lines and in the lungs of BALB/c mice via instillation delivery. In vitro studies showed that D-SPM could partially protect pDNA from degradation by nuclease and exhibited optimal gene transfer efficiency at D-SPM to pDNA weight-mixing ratio of 12. In the lungs of mice, the levels of gene expression generated by D-SPM/pDNA are highly dependent on the weight-mixing ratio of D-SPM to pDNA, amount of pDNA in the complex, and the assay time postdelivery. Readministration of the complex at day 1 following the first dosing showed no significant effect on the retention and duration of gene expression. The study also showed that there was a clear trend of increasing size of the complexes as the amount of pDNA was increased, where the sizes of the D-SPM/pDNA complexes were within the nanometer range.
The failure of colorectal cancer treatments is partly due to overexpression of CXCR4 by tumor cells, which plays a critical role in cell metastasis. Moreover, serum alkaline phosphatase (ALP) levels are frequently elevated in patients with metastatic colorectal cancer. A polysaccharide, dextran, was chosen as the vector of siRNA. Spermine was conjugated to oxidized dextran by reductive amination process to obtain cationized dextran, so-called dextran-spermine, in order to prepare CXCR4-siRNAs/dextran-spermine nanoparticles. The fabricated nanoparticles were used in order to investigate whether downregulation of CXCR4 expression could affect serum ALP in mouse models of colorectal cancer.
Plasmid DNA (pDNA)-based vaccines have emerged as effective subunit vaccines against viral and bacterial pathogens. In this study, a DNA vaccine, namely plasmid internal ribosome entry site-HN/F, was applied in ovo against Newcastle disease (ND). Vaccination was carried out using the DNA vaccine alone or as a mixture of the pDNA and dextran-spermine (D-SPM), a nanoparticle used for pDNA delivery. The results showed that in ovo vaccination with 40 μg pDNA/egg alone induced high levels of antibody titer (P<0.05) in specific pathogen-free (SPF) chickens at 3 and 4 weeks postvaccination compared to 2 weeks postvaccination. Hemagglutination inhibition (HI) titer was not significantly different between groups injected with 40 μg pDNA + 64 μg D-SPM and 40 μg pDNA at 4 weeks postvaccination (P>0.05). Higher antibody titer was observed in the group immunized with 40 μg pDNA/egg at 4 weeks postvaccination. The findings also showed that vaccination with 40 μg pDNA/egg alone was able to confer protection against Newcastle disease virus strain NDIBS002 in two out of seven SPF chickens. Although the chickens produced antibody titers 3 weeks after in ovo vaccination, it was not sufficient to provide complete protection to the chickens from lethal viral challenge. In addition, vaccination with pDNA/D-SPM complex did not induce high antibody titer when compared with naked pDNA. Therefore, it was concluded that DNA vaccination with plasmid internal ribosome entry site-HN/F can be suitable for in ovo application against ND, whereas D-SPM is not recommended for in ovo gene delivery.