Broadband terahertz absorber realized by self-assembled multilayer glass spheres

A broadband terahertz (THz) absorber consisting of multilayer glass spheres and polydimethylsiloxane (PDMS) was realized. The multilayer glass spheres were deposited by repeating a self-assembly method used to form monolayer glass spheres and by the spin-coating of PDMS to fill the gaps between the glass spheres. The average reflection at the surface of the absorber was 0.8% and the absorbance was higher than 98% in the frequency range between 0.7 to 2.0 THz.

Directed evolution of adeno-associated virus for enhanced gene delivery and gene targeting in human pluripotent stem cells

Efficient approaches for the precise genetic engineering of human pluripotent stem cells (hPSCs) can enhance both basic and applied stem cell research. Adeno- associated virus (AAV) vectors are of particular interest for their capacity to mediate efficient gene delivery to and gene targeting in various cells. However, natural AAV serotypes offer only modest transduction of human embryonic and induced pluripotent stem cells (hESCs and hiPSCs), which limits their utility for efficiently manipulating the hPSC genome. Directed evolution is a powerful means to generate viral vectors with novel capabilities, and we have applied this approach to create a novel AAV variant with high gene delivery efficiencies (~50%) to hPSCs, which are importantly accompanied by a considerable increase in gene-targeting frequencies, up to 0.12%. While this level is likely sufficient for numerous applications, we also show that the gene-targeting efficiency mediated by an evolved AAV variant can be further enhanced (>1%) in the presence of targeted double- stranded breaks (DSBs) generated by the co-delivery of artificial zinc finger nucleases (ZFNs). Thus, this study demonstrates that under appropriate selective pressures, AAV vectors can be created to mediate efficient gene targeting in hPSCs, alone or in the presence of ZFN- mediated double-stranded DNA breaks.

Colloids as mobile substrates for the implantation and integration of differentiated neurons into the mammalian brain

Neuronal degeneration and the deterioration of neuronal communication lie at the origin of many neuronal disorders, and there have been major efforts to develop cell replacement therapies for treating such diseases. One challenge, however, is that differentiated cells are challenging to transplant due to their sensitivity both to being uprooted from their cell culture growth support and to shear forces inherent in the implantation process. Here, we describe an approach to address these problems. We demonstrate that rat hippocampal neurons can be grown on colloidal particles or beads, matured and even transfected in vitro, and subsequently transplanted while adhered to the beads into the young adult rat hippocampus. The transplanted cells have a 76% cell survival rate one week post-surgery. At this time, most transplanted neurons have left their beads and elaborated long processes, similar to the host neurons. Additionally, the transplanted cells distribute uniformly across the host hippocampus. Expression of a fluorescent protein and the light-gated glutamate receptor in the transplanted neurons enabled them to be driven to fire by remote optical control. At 1-2 weeks after transplantation, calcium imaging of host brain slice shows that optical excitation of the transplanted neurons elicits activity in nearby host neurons, indicating the formation of functional transplant-host synaptic connections. After 6 months, the transplanted cell survival and overall cell distribution remained unchanged, suggesting that cells are functionally integrated. This approach, which could be extended to other cell classes such as neural stem cells and other regions of the brain, offers promising prospects for neuronal circuit repair via transplantation of in vitro differentiated, genetically engineered neurons.

Electrospun nanofibrous scaffolds for controlled release of adeno-associated viral vectors

The integration of viral gene delivery with key features of biomaterial scaffolds that modulate viral delivery in a controlled manner offers a promising strategy for numerous tissue engineering applications. In this study adeno-associated virus (AAV), which is widely utilized in human gene therapy as a gene carrier due to its safety and efficient gene delivery capability, was encapsulated within electrospun nanofibrous scaffolds composed of blended mixtures of elastin-like polypeptides (ELP) and poly (ε-caprolactone) (PCL) and was employed to transduce fibroblasts adherent on the scaffolds. Combinatorial interactions between ELP and PCL chains upon physical blending significantly altered the mechanical properties (i.e. wettability, elastic modulus, strain, etc.) of the ELP/PCL composites, thus providing key tools to mediate controlled release of AAV vectors and robust cellular transduction on the fibrous scaffolds. The ability of ELP/PCL composites to manipulate the controlled release of AAV-mediated gene delivery for subsequent high-efficiency cellular transduction will provide tremendous opportunities for a variety of tissue engineering applications.

Heparin-coated superparamagnetic nanoparticle-mediated adeno-associated virus delivery for enhancing cellular transduction

Superparamagnetic iron oxide nanoparticles (SPIONs) have been exploited as an elegant vehicle to enhance gene delivery efficiencies in gene therapy applications. We developed a magnetically guided adeno-associated virus (AAV) delivery system for enhancing gene delivery to HEK293T and PC12 cell lines. Wild-type AAV2 and a novel AAV vector, AAVr3.45, which was directly evolved in a previous study to possess diverse cell tropisms, were used as gene carriers. Additionally, the affinity of each viral vector to heparin was employed as a moiety to immobilize virus onto heparin-coated SPIONs (HpNPs). Magnetically guided AAV delivery resulted fast and efficient cellular transduction. Importantly, a short exposure of virus to target cells under a magnetic field (<180min) yielded comparable transduction produced by the conventional gene-delivery protocol (i.e., 24h-incubation of virus with target cells prior to replacing with fresh medium). Additionally, magnetic guidance of AAV encoding nerve growth factor (NGF) produced sufficient functional NGF, leading to robust neurite elongation by PC12 as compared to direct NGF protein delivery or non-magnetic delivery. The successful establishment of a magnetically guided AAV delivery system, with the ability to efficiently and rapidly infect target cells, will provide a powerful platform for a variety of gene therapy applications.

A high-coverage nanoparticle monolayer for the fabrication of a subwavelength structure on InP substrates

Subwavelength structures (SWSs) were fabricated on the Indium Phosphide (InP) substrate by utilizing the confined convective self-assembly (CCSA) method followed by reactive ion etching (RIE). The surface condition of the InP substrate was changed by depositing a 30-nm-thick SiO2 layer and subsequently treating the surface with O2 plasma to achieve better surface coverage. The surface coverage of nanoparticle monolayer reached 90% by using O2 plasma-treated SiO2/InP substrate among three kinds of starting substrates such as the bare InP, SiO2/InP and O2 plasma-treated SiO2/InP substrate. A nanoparticle monolayer consisting of polystyrene spheres with diameter of 300 nm was used as an etch mask for transferring a two-dimensional periodic pattern onto the InP substrate. The fabricated conical SWS with an aspect ratio of 1.25 on the O2 plasma-treated SiO2/InP substrate exhibited the lowest reflectance. The average reflectance of the conical SWS was 5.84% in a spectral range between 200 and 900 nm under the normal incident angle.

Engineering biomaterial systems to enhance viral vector gene delivery

Integrating viral gene delivery with engineered biomaterials is a promising strategy to overcome a number of challenges associated with virus-mediated gene delivery, including inefficient delivery to specific cell types, limited tropism, spread of vectors to distant sites, and immune responses. Viral vectors can be combined with biomaterials either through encapsulation within the material or immobilization onto a material surface. Subsequent biomaterial-based delivery can increase the vector's residence time within the target site, thereby potentially providing localized delivery, enhancing transduction, and extending the duration of gene expression. Alternatively, physical or chemical modification of viral vectors with biomaterials can be employed to modulate the tropism of viruses or reduce inflammatory and immune responses, both of which may benefit transduction. This review describes strategies to promote viral gene delivery technologies using biomaterials, potentially providing opportunities for numerous applications of gene therapy to inherited or acquired disorders, infectious disease, and regenerative medicine.

Aberrant ventral striatal responses during incentive processing in unmedicated patients with obsessive-compulsive disorder

OBJECTIVE

Obsessive-compulsive disorder (OCD) is characterized by the dysfunction of control and reward mechanisms. However, only few neuroimaging studies of OCD have examined the reward processing. We examined the neural responses during incentive processing in OCD.

METHOD

  Twenty unmedicated patients with OCD and 20 age-, sex-, and IQ-matched healthy controls underwent functional magnetic resonance imaging while performing a modified monetary incentive delay task.

RESULTS

Compared with controls, patients with OCD showed increased ventral striatal activation in the no-loss minus loss outcome contrast and a significant positive correlation between the ventral striatal activation and compulsion symptom severity. In addition, patients with OCD showed increased activations in the frontostriatal regions in the gain minus no-gain outcomes contrast. During loss anticipation, patients with OCD showed less activations in the lateral prefrontal and inferior parietal cortices. However, during gain anticipation, patients with OCD and healthy controls did not differ in the ventral striatal activation.

CONCLUSION

These findings provide neural evidence for altered incentive processing in unmedicated patients with OCD, suggesting an elevated sensitivity to negatively affect stimuli as well as dysfunction of the ventral striatum.

Abstract P3-10-25: The Prognosis of Metaplastic Breast Cancer Patients Compare to Triple-Negative Breast Cancer Patients

Background: Metaplastic breeast cancer (MBC) is a rare, heterogenous cancer characterized by admixture of adenocarcinoma with metaplastic elements, low hormone receptor expression and poor outcome. This study was planned to assess the clinicopathological chacteristics and immunohistochemical findings of MBC compared to invasive ductal carcinoma (IDC) including the triple-negative subtype (TN-IDC). Material and Methods: We retrospectively reviewed the medical records of 47 MBC and 1,346 IDC patients. Two hundred eighteen TN-IDC patients were included in the 1,346 IDC patients. Between 2005 and 2009, these patients were undergone surgical treatment at the Samsung Medical Center. Patients were reviewed clinicopathologic factors, immunohistochemistry of biologic factors such as ER, PR, HER-2, p53, Ki67, cytokeratine (CK) 5/6, epidermal growth factor receptor (EGFR), and treatment modalities (type of operation, use of chemotherapy, radiotherapy and hormone therapy). Result: The MBC patients presented with a larger tumor size (&gt;T1, 66.0% vs. 44.3.%, P = 0.008), lower lymph node involvement (N0, 73.3% vs. 55.6%, P = 0.03), higher histologic (HG) and nuclear grade (NG) (HG3, 70.0% vs. 41.5%, P = 0.001; NG3,82.6% vs. 46.9%, P &lt; 0.001), fewer estrogen receptor (ER), progesterone receptor (PR) and HER2 positivity (ER+, 4.3% vs. 69.2%, P &lt; 0.001; PR+, 6.4% vs. 63.5%, P &lt; 0.001; HER2+, 0% vs. 27.6%, P &lt; 0.001), higher p53, CK5/6 and EGFR expression (p53+, 63.8% vs.38.8%, P &lt; 0.001; CK5/6+, 71.9% vs.21.5%, P &lt; 0.001; EGFR+, 93.9% vs.21.6%, P &lt;0.001) and more TN subtypes (93.6% vs. 16.2%, P &lt; 0.001) compared to the IDC group. There was no significant difference in clinicopathological characteristics with MBC and TN-IDC except EGFR over expression (EGFR+, 93.9% vs.69.0%, P = 0.017). In follow-up duration (median 30 months, range 2-56 months), seven (14.9%) MBC patients and 98 (7.2%) IDC patients recurred. The 3-year disease-free survival (DFS) rate was 78.1% in the MBC group and 91.1% in IDC group (P &lt;0.001). The 3-year DFS rate was not significantly difference between MBC group and TN-IDC group (78.1% vs. 84.9%, P = 0.114). However, in patients with lymph node metastasis who underwent adjuvant chemotherapy, the 3-year DFS rate was 44.4% in MBC group and 72.5% in TN-IDC group (P = 0.025).

Discussion: In our result, MBC show poorer clinical outcome than IDC. It is not shown significant difference between MBC and TN-IDC. However, MBC patients with nodal metastasis have poorer prognosis than TN-IDC patients with metastasis despite adjuvant chemotherapy.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P3-10-25.

Design and construction of a compact microwave proton source for a proton linac

A 100 MeV, 20 mA proton linear accelerator is being developed by the Proton Engineering Frontier Project at the Korea Atomic Energy Research Institute. 20 MeV acceleration system using radio frequency quadrupole and drift tube linac was already developed and has been tested. To operate this acceleration system with a long time, more reliable proton source is needed. A compact microwave proton source was proposed and has been designed and constructed as a prototype ion source for the 100 MeV proton linear accelerator. The design of microwave power injection system is based on the microwave proton injector at LANL and CEA. The wave power from a 2.45 GHz, 2 kW magnetron source is introduced into a compact plasma chamber with 7 cm diameter and 5 cm length through a standard tapered, double-ridged waveguide (WRD250) and a quartz window. The microwave power supply is installed on high voltage platform. Axial magnetic fields up to 1 kG can be provided with a water-cooled solenoid coil. A single-hole three electrode extraction system is designed for an extraction current up to 30 mA at a 50 kV extraction voltage. The design and initial operations of the proton source are presented.

Molecular evolution of adeno-associated virus for enhanced glial gene delivery

The natural tropism of most viral vectors, including adeno-associated viral (AAV) vectors, leads to predominant transduction of neurons and epithelia within the central nervous system (CNS) and retina. Despite the clinical relevance of glia for homeostasis in neural tissue, and as causal contributors in genetic disorders such as Alzheimer's and amyotrophic lateral sclerosis, efforts to develop more efficient gene delivery vectors for glia have met with limited success. Recently, viral vector engineering involving high-throughput random diversification and selection has enabled the rapid creation of AAV vectors with valuable new gene delivery properties. We have engineered novel AAV variants capable of efficient glia transduction by employing directed evolution with a panel of four distinct AAV libraries, including a new semi-random peptide replacement strategy. These variants transduced both human and rat astrocytes in vitro up to 15-fold higher than their parent serotypes, and injection into the rat striatum yielded astrocyte transduction levels up to 16% of the total transduced cell population, despite the human astrocyte selection platform. Furthermore, one variant exhibited a substantial shift in tropism toward Müller glia within the retina, further highlighting the general utility of these variants for efficient glia transduction in multiple species within the CNS and retina.

DNA shuffling of adeno-associated virus yields functionally diverse viral progeny

Adeno-associated virus (AAV) vectors are extremely effective gene-delivery vehicles for a broad range of applications. However, the therapeutic efficacy of these and other vectors is currently limited by barriers to safe, efficient gene delivery, including pre-existing antiviral immunity, and infection of off-target cells. Recently, we have implemented directed evolution of AAV, involving the generation of randomly mutagenized viral libraries based on serotype 2 and high-throughput selection, to engineer enhanced viral vectors. Here, we significantly extend this capability by performing high-efficiency in vitro recombination to create a large (10(7)), diverse library of random chimeras of numerous parent AAV serotypes (AAV1, 2, 4-6, 8, and 9). In order to analyze the extent to which such highly chimeric viruses can be viable, we selected the library for efficient viral packaging and infection, and successfully recovered numerous novel chimeras. These new viruses exhibited a broad range of cell tropism both in vitro and in vivo and enhanced resistance to human intravenous immunoglobulin (IVIG), highlighting numerous functional differences between these chimeras and their parent serotypes. Thus, directed evolution can potentially yield unlimited numbers of new AAV variants with novel gene-delivery properties, and subsequent analysis of these variants can further extend basic knowledge of AAV biology.

Decreased phosphorylation of STAT-1, STAT-4 and cytokine release in MDR-TB patients with primary resistance

SETTING

We recently showed that treatment failure rate was higher among multidrug-resistant tuberculosis (MDR-TB) patients without a previous history of tuberculosis (TB) treatment, or so-called 'primary resistance'.

OBJECTIVE

To investigate the phosphorylation levels of signal transducers and activators of transcription-1 (STAT-1) and STAT-4 and the subsequent cytokine release as a possible cause of a poor prognosis in MDR-TB patients with primary resistance.

DESIGN

Ten patients with successfully treated pulmonary TB without resistance, 12 MDR-TB patients with acquired resistance and 10 MDR-TB patients with primary resistance were enrolled. After 24 h stimulation of peripheral blood mononuclear cells (PBMC) with interferon-gamma (IFN-gamma), interleukin-12 (IL-12), purified protein derivative (PPD), or lysate of Mycobacterium tuberculosis, flow cytometric analysis of intracellular pSTAT-1 and pSTAT-4 were performed and secretion of IFN-gamma, IL-12p40 and tumour necrosis factor-alpha (TNF-alpha) was measured in culture supernatant.

RESULTS

The mean fluorescent intensities of pSTAT-1 and pSTAT-4 in PBMC of MDR-TB patients with primary resistance decreased on stimulation of IFN-gamma, PPD or lysate of M. tuberculosis when compared with patients with acquired resistance. In addition, secretion of IFN-gamma, IL-12p40 and TNF-alpha in these patients decreased on various stimuli.

CONCLUSION

Decreased phosphorylation of STAT-1, STAT-4, and of subsequent cytokine release, might be associated with a poor prognosis in MDR-TB patients with primary resistance.

Characterization of time-related changes after experimental bile duct ligation

BACKGROUND

Although bile duct ligation (BDL) in mice is used to study cholestasis, a detailed description of this animal model is lacking. The aim of this study was to define specific phases of acute and chronic injury and repair in the different cellular compartments of the liver.

METHODS

C57BL/6 mice underwent BDL or sham laparotomy, and serum and liver tissue were analysed between 8 h and 6 weeks later.

RESULTS

Biliary infarcts and alanine aminotransferase levels revealed acute hepatocellular injury peaking at days 2-3, paralleled by enhanced transcription of pro-proliferative mediators and followed by a distinct peak of hepatocellular proliferation at day 5. Cholangiocellular proliferation occurred in large bile ducts on days 2-3 and in small bile ducts on day 5. Neutrophil infiltration occurred within 8 h, with neutrophils remaining the predominant immune cell type until day 3. Acute injury was followed by continuous tissue repair, lymphocyte and Kupffer cell infiltration, and accumulation of collagen during the second week. Thereafter, the number of alpha-smooth muscle actin-positive cells and the expression of transforming growth factor beta1, tissue inhibitor of metalloproteinases 1 and procollagen (I) decreased, and liver fibrosis stabilized.

CONCLUSION

BDL elicits dynamic changes in mouse liver. The chronological dissection and quantification of these events identified specific phases of acute and chronic cholestatic liver injury.

Library selection and directed evolution approaches to engineering targeted viral vectors

Gene therapy, to delivery of genetic material to a patient for therapeutic benefit, has significant promise for translating basic knowledge of disease mechanism into biomedical treatments. The clinical development of the field has been slowed, however, by the need for improvements in the properties and capabilities of gene delivery vehicles. Vehicles based on viruses offer the potential for efficient gene delivery, but because viruses did not evolve to serve human therapeutic needs, many of their properties require significant improvement, including their safety, efficiency, and capacity for targeted gene delivery. Since viruses are highly complex biological entities, engineering such properties at the molecular level can be challenging. However, there has been significant progress in developing approaches that mimic the mechanisms by which viruses arose in the first place. In particular, library-based selection, the generation of one diverse genetic library and selection for new properties, and directed evolution, based on the multiple rounds of library generation and selection for iterative improvement of function, have strong potential in engineering novel properties into these complex biomolecular assemblies. This review will discuss progress in the application of peptide display, library selection, and directed evolution technologies toward engineering vectors based on retrovirus, adeno-associated virus, and adenovirus that are capable of targeted delivery to specific cell types. In addition to creating biomedically useful products, these approaches have future potential to yield novel insights into viral structure-function relationships.

White matter abnormalities in drug-naïve patients with obsessive-compulsive disorder: a diffusion tensor study before and after citalopram treatment

OBJECTIVE

The aim was to investigate the white matter abnormalities of drug-naïve patients with obsessive-compulsive disorder (OCD) using diffusion tensor-imaging and the white matter changes in the patients after pharmacotherapy.

METHOD

Thirteen drug-naïve OCD patients and 13 age- and sex-matched healthy comparison subjects were examined using diffusion tensor-imaging and structural magnetic resonance imaging. Measurements were made in OCD patients before and after 12 weeks of citalopram treatment.

RESULTS

Compared with controls, the drug-naïve OCD patients showed significant increases in fractional anisotropy (FA) in the corpus callosum, the internal capsule and white matter in the area superolateral to the right caudate. The increases in FA were mostly no longer observed in patients after 12 weeks of treatment compared with controls.

CONCLUSION

Our findings suggest that white matter alterations are associated with the pathophysiology of OCD, and the abnormalities may be partly reversible with pharmacotherapy.

Engineering adeno-associated virus for one-step purification via immobilized metal affinity chromatography

Adeno-associated virus (AAV) is a promising vehicle for gene therapy, which will rely on the generation of high-titer, high-purity recombinant vectors. However, numerous purification protocols can involve challenging optimization or scalability issues, and most AAV serotypes do not bind heparin or sialic acid, used for AAV2/3 or AAV4/5 purification, requiring the development of new chromatography strategies. Immobilized metal affinity chromatography (IMAC) allows for robust protein purification via affinity tags such as the hexahistidine (His(6)) sequence. Through the combination of a diverse AAV2 library and rational peptide insertions, we have located an optimal His(6) tag insertion site within the viral capsid. This mutant and a related AAV8 variant can be purified from clarified cell lysate in a single gravity column step at infectious particle yields exceeding 90%. Furthermore, injection of IMAC-purified vector into the brain demonstrates that it mediates high-efficiency gene delivery in vivo, equivalent to that of wild-type capsid, with minimal immune cell activation. This affinity chromatography method may offer advantages in ease of purification, final vector purity, and process scalability. Moreover, a combined rational design and high-throughput library selection approach can aid in the design of enhanced viral gene delivery vectors.

Patterned PLG substrates for localized DNA delivery and directed neurite extension

Tissue engineering strategies that enable nerve regeneration will require methods that can promote and direct neurite extension across the lesion. In this report, we investigate an in vitro combinatorial approach to directed neurite outgrowth using gene delivery from topographically patterned substrates, which can induce expression of neurotrophic factors to promote neurite extension and direct the extending neurites. Poly(lactide-co-glycolide) (PLG), which has been used to fabricate conduits or bridges for regeneration, was compression molded to create channels with 100, 150, and 250 microm widths. DNA complexes were immobilized to the PLG, and cells cultured on the substrate were transfected with efficiencies dependent on channel width and DNA amount. A co-culture model consisting of primary neurons and accessory cells was employed to investigate neurite outgrowth within the channels. Localized secretion of nerve growth factor (NGF) by the accessory cells promoted neuron survival and neurite extension. Neurons cultured in channels with NGF expression exhibited longer primary neurites than in the absence of channels. Neurons cultured in smaller width PLG microchannels exhibited a greater degree of directionality and less secondary sprouting than larger channels. Finally, surface immobilization allowed for the delivery of distinct plasmids from each channel, which may enable channels to be tailored for specific nerve tracts. This approach demonstrates the ability to combine gene delivery with physical guidance, and can be tailored to target specific axonal populations with varying neurotrophic factor requirements.

Characteristics of indicator microorganisms in paddy rice plots after reclaimed water irrigation

A study was performed to examine the effects of reclaimed-water irrigation on microorganism concentration in the ponded-water of paddy rice plots. Several treatments were used and each one was triplicated to evaluate the change of indicator microorganisms (total coliforms (TC), faecal coliforms (FC), and E. coli) concentrations in 2003 and 2004 growing seasons. Their concentrations increased significantly after irrigation, but decreased by approximately 45% in 24 h. It implies that agricultural activities such as ploughing and fertilising need to be practiced one or two days after irrigation, considering health risks. Treatments with UV-disinfected water irrigation, demonstrated significantly lower concentrations than others, including control plots where natural water was irrigated. The monitoring result from actual paddy rice fields and experimental paddy plots showed that concentrations of indicator microorganisms ranged from 10(2) to 10(5) MPN/100 mL. The field scale water reuse research project is in progress and national guidelines for reclaimed-water irrigation are under preparation in Korea. A comprehensive assessment of existing agricultural practices and a thorough monitoring in the fields as well as treatment plots are recommended to make national guidelines more representative.

Integrated modelling under uncertainty in watershed-level assessment and management

Uncertainty in water quality model predictions is inevitably high due to natural stochasticity, model uncertainty, and parameter uncertainty. An integrated modelling system (modified-BASINS) under uncertainty is described and demonstrated for use in receiving-water quality prediction and watershed management. A Monte Carlo simulation was used to investigate the effect of various uncertainty types on output prediction. Without pollution control measures in the watershed, the concentrations of total nitrogen (T-N) and total phosphorus (T-P) in the Hwaong Reservoir, considering three uncertainty types, would be less than about 4.4 and 0.23 mg L(-1), respectively, in 2012, with 90% confidence. The effects of two watershed management practices, wastewater treatment plants (WWTP) and constructed wetlands (WETLAND), were evaluated. The combined scenario (WWTP + WETLAND) was the most effective at improving reservoir water quality, bringing concentrations of T-N and T-P in the Hwaong Reservoir to less than 3.4 and 0.14 mg L(-1), 24 and 41% improvements, respectively, with 90% confidence. Overall, the Monte Carlo simulation in the integrated modelling system was practical for estimating uncertainty and reliable in water quality prediction. The approach described here may allow decisions to be made based on the probability and level of risk, and its application is recommended.