The influence of patient positioning and immobilization equipment on MR image quality and image registration in radiation therapy

INTRODUCTION

MRI is preferred for brain tumor assessment, while CT is used for radiotherapy simulation. This study evaluated immobilization equipment's impact on CT-MRI registration accuracy and MR image quality in RT setup.

METHODS

We included CT and MR images from 11 patients with high-grade glioma, all of whom were immobilized with a thermoplastic mask and headrest. T1- and T2-weighted MR images were acquired using an MR head coil in a diagnostic setup (DS) and a body matrix coil in RT setup. To assess MR image quality, signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were considered in some dedicated regions of interest. We also evaluated the impact of immobilization equipment on CT-MRI rigid registration using line profile and external contour methods.

RESULTS

The CNR and SNR reduction was in the RT setup of imaging. This was more evident in T1-weighted images than in T2-weighted ones. The SNR decreased by 14.91% and 12.09%, while CNR decreased by 25.12% and 20.15% in T1- and T2-weighted images, respectively. The immobilization equipment in the RT setup decreased the mean error in rigid registration by 1.02 mm. The external contour method yielded Dice similarity coefficients (DSC) of 0.84 and 0.92 for CT-DS MRI and CT-RT MRI registration, respectively.

CONCLUSION

The image quality reduction in the RT setup was due to the imaged region's anatomy and its position relative to the applied coil. Furthermore, optimizing the pulse sequence is crucial for MR imaging in RT applications. Although the use of immobilization equipment may decrease the image quality in the RT setup, it does not affect organ delineation, and the image quality is still satisfactory for this purpose. Also, the use of immobilization equipment in the RT setup has increased registration accuracy.

Global incidence of surgical site infections following caesarean section: a systematic review and meta-analysis

BACKGROUND

Surgical site infection (SSI) is a health-threatening complication following caesarean section (CS); however, to the authors' knowledge, there is no worldwide estimate of the burden of post-CS SSIs. Therefore, this systematic review and meta-analysis aimed to estimate the global and regional incidence of post-CS SSIs and associated factors.

METHODS

International scientific databases were searched systematically for observational studies published from January 2000 to March 2023, without language or geographical restrictions. The pooled global incidence rate was estimated using a random-effects meta-analysis (REM), and then stratified by World-Health-Organization-defined regions as well as by sociodemographic and study characteristics. Causative pathogens and associated risk factors of SSIs were also analysed using REM. Heterogeneity was assessed with I2.

RESULTS

In total, 180 eligible studies (207 datasets) involving 2,188,242 participants from 58 countries were included in this review. The pooled global incidence of post-CS SSIs was 5.63% [95% confidence interval (CI) 5.18-6.11%]. The highest and lowest incidence rates for post-CS SSIs were estimated for the African (11.91%, 95% CI 9.67-14.34%) and North American (3.87%, 95% CI 3.02-4.83%) regions, respectively. The incidence was significantly higher in countries with lower income and human development index levels. The pooled incidence estimates have increased steadily over time, with the highest incidence rate during the coronavirus disease 2019 pandemic (2019-2023). Staphylococcus aureus and Escherichia coli were the most prevalent pathogens. Several risk factors were identified.

CONCLUSION

An increasing and substantial burden from post-CS SSIs was identified, especially in low-income countries. Further research, greater awareness and the development of effective prevention and management strategies are warranted to reduce post-CS SSIs.

A novel plasmonic metal-semiconductor-insulator-metal (MSIM) color sensor compatible with CMOS technology

Color detection is one of the top interests in both biological and industrial applications. Specifically, the Determination of the light wave characteristics is vital in photonic technology. One of the features in the color sense that should be found out is its wavelength or color. In this work, we propose a structure that can be used to detect RGB colors separately in an efficient way. The proposed detector consists of the plasmonic filter sensing desired wavelength (red, green, and blue) and the PN diode to convert the received photons to the electrical current. At the input intensity of 1 mW × cm-2, the current density for blue, green, and red colors are 27, 35, and 48 µA × cm-2, respectively. It is shown that the intensities needed to obtain the current densities of 0.1 µA × cm-2 are 3.94, 2.98, and 2.25 µW × cm-2 for the blue, green, and red spectra respectively. It should mention that by using high-precision photodetector structures such as PIN diode, the minimum detectable level can be decreased. Simple adjusting for desired wavelength and linear operation for different input intensities are the characteristics of the designed structure. This detector is compatible with CMOS technology and can be easily utilized in numerous applications, such as charge-coupled devices, displays, and cameras.

Selective band amplification in ultra-broadband superimposed quantum dot reflective semiconductor optical amplifiers

In this paper, an approach is proposed for an ultra-broadband quantum dot (QD) reflective semiconductor optical amplifier using superimposed QDs with switching and band selection capability in the supported band. Furthermore, about 1 µm optical bandwidth is covered (O, E, S, C, and L bands), which is the desired region in most optical communication applications. Three optical windows are selected for optimized amplification (1.55 µm, 1.5 µm, 1.31 µm). Also, they can be amplified either simultaneously or one at a time, which guarantees independent modulation. This is a remarkable property in fast data transmission. The amplifier is devised by solution process nanotechnology, which guarantees its synthesizing feasibility with low cost. Finally, by introducing this amplifier, one step is taken toward the development of fast wavelength division multiplexing passive optical networks.

Monte Carlo-based calculation of nano-scale dose enhancement factor and relative biological effectiveness in using different nanoparticles as a radiosensitizer

INTRODUCTION

Nowadays, some nanoparticles (NPs) are known and used as radiosensitizers in radiotherapy and radiobiology, due to their desired biological, physical, and chemical effects on cells. This study aimed to evaluate and compare the dose enhancement factor (DEF) and the biological effectiveness of some common NPs through EGSnrc and MCDS Monte Carlo (MC) simulation codes.

MATERIALS AND METHODS

To evaluate considered NPs' DEF, a single NP with 50 nm diameter was simulated at the center of concentric spheres. NP irradiations were done with 30, 60, and 100 keV photon energies. The secondary electron spectra were scored at the surface of considered NPs, and the dose values were scored at surrounding water-filled spherical shells which were distributed up to 4000 nm from the NP surface. The electron spectra were used in the MCDS code to obtain different initial DNA damages for the calculation of enhanced relative biological effectiveness (eRBE).

RESULTS

By decreasing the photon energy, an increment of DEF was seen for all studied NPs. The maximum DEF at 30, 60, and 100 keV photon energies were respectively related to silver (Ag), gadolinium (Gd), and bismuth (Bi) NPs. The maximum double-strand break (DSB) related (eRBE_DSB) values for the 30 keV photon belonged to Ag, while BiNPs showed the maximum values at other photon energies. The minimum eRBE_DSB values were also related to iron (Fe) NPs at the entire range of studied photon energies.

CONCLUSIONS

The compared nanoscale physical and biological results of our study can be helpful in the selection of optimum NP as a radiosensitizer in future radiobiological studies. Bi, gold (Au), Ag, and platinum (Pt) NPs had great potential, respectively, as radiosensitizers relative to the other studied NPs.

Evaluation of the heart and lung dosimetric parameters in deep inspiration breath hold using 3D Slicer

Purpose

The present study was conducted to compare dosimetric parameters for the heart and left lung between free breathing (FB) and deep inspiration breath hold (DIBH) and determine the most important potential factors associated with increasing the lung dose for left-sided breast radiotherapy using image analysis with 3D Slicer software.

Materials and Methods

Computed tomography-simulation scans in FB and DIBH were obtained from 17 patients with left-sided breast cancer. After contouring, three-dimensional conformal plans were generated for them. The prescribed dose was 50 Gy to the clinical target volume. In addition to the dosimetric parameters, the irradiated volumes and both displacement magnitudes and vectors for the heart and left lung were assessed using 3D Slicer software.

Results

The average of the heart mean dose (D_mean) decreased from 5.97 to 3.83 Gy and V₂₅ from 7.60% to 3.29% using DIBH (p < 0.001). Furthermore, the average of D_mean for the left lung was changed from 8.67 to 8.95 Gy (p = 0.389) and V₂₀ from 14.84% to 15.44% (p = 0.387). Both of the absolute and relative irradiated heart volumes decreased from 42.12 to 15.82 mL and 8.16% to 3.17%, respectively (p < 0.001); however, these parameters for the left lung increased from 124.32 to 223.27 mL (p < 0.001) and 13.33% to 13.99% (p = 0.350). In addition, the average of heart and left lung displacement magnitudes were calculated at 7.32 and 20.91 mm, respectively.

Conclusion

The DIBH is an effective technique in the reduction of the heart dose for tangentially treated left sided-breast cancer patients, without a detrimental effect on the left lung.

Global prevalence of latent toxoplasmosis in pregnant women: a systematic review and meta-analysis

BACKGROUND

Toxoplasma gondii infection, if acquired as an acute infection during pregnancy, can have substantial adverse effects on mothers, fetuses and newborns. Latent toxoplasmosis also causes a variety of pathologies and has been linked to adverse effects on pregnancy.

OBJECTIVE

Here, we present results of a comprehensive systematic review and meta-analysis of the global prevalence of latent toxoplasmosis in pregnant women.

DATA SOURCE

We searched PubMed, EMBASE, Web of Science, SciELO and Scopus databases for relevant studies that were published between 1 January 1988 and 20 July 2019.

STUDY ELIGIBILITY CRITERIA

All population-based, cross-sectional and longitudinal studies reporting the prevalence of latent toxoplasmosis in healthy pregnant women were considered for inclusion.

PARTICIPANTS

Pregnant women who were tested for prevalence of latent toxoplasmosis.

INTERVENTIONS

There were no interventions.

METHOD

We used a random effects model to calculate pooled prevalence estimates with 95% confidence intervals (CIs). We grouped prevalence data according to the geographic regions defined by the World Health Organization (WHO). Multiple subgroup and meta-regression analyses were performed.

RESULTS

In total, 311 studies with 320 relevant data sets representing 1 148 677 pregnant women from 91 countries were eligible for inclusion in the meta-analysis. The global prevalence of latent toxoplasmosis in pregnant women was estimated at 33.8% (95% CI, 31.8-35.9%; 345 870/1 148 677). South America had the highest pooled prevalence (56.2%; 50.5-62.8%) of latent toxoplasmosis in pregnant women, whereas the Western Pacific region had the lowest prevalence (11.8%; 8.1-16.0%). A significantly higher prevalence of latent toxoplasmosis was associated with countries with low income and low human development indices (p < 0.001).

CONCLUSION

Our results indicate a high level of latent toxoplasmosis in pregnant women, especially in some low- and middle-income countries of Africa and South America, although the local prevalence varied markedly. These results suggest a need for improved prevention and control efforts to reduce the health risks to women and newborns.

Toxocara eggs in public places worldwide - A systematic review and meta-analysis

Toxocariasis is a neglected tropical disease of humans. Although many studies have indicated or shown that environmental contamination with Toxocara species eggs is a major risk factor for toxocariasis in humans, there has been no comprehensive analysis of published data or information. Here, we conducted the first systematic review and meta-analysis of current literature to assess the global prevalence of Toxocara eggs in public places (including beaches, parks and playgrounds). We conducted searches of the PubMed, Embase, Scopus and Science Direct databases for relevant studies published until 20 April 2018, and assessed the prevalence rates of Toxocara eggs in public places. We used the random effects model to calculate pooled prevalence estimates, with 95% confidence intervals (CIs), and analysed data in relation to WHO geographical regions. Subgroup analysis and meta-regressions regarding the geographical and environmental variables were also performed. Of 2384 publications identified, 109 studies that tested 42,797 soil samples in 40 countries were included in the meta-analysis. The pooled global prevalence of Toxocara eggs in public places was 21% (95% CI, 16-27%; 13,895/42,797). The estimated prevalence rates in the different WHO regions ranged from 13% to 35%: Western Pacific (35%; 95% CI, 15-58%), Africa (27%; 95% CI, 11-47%), South America (25%; 95% CI, 13-33%), South-East Asia (21%; 95% CI, 3-49%), Middle East and North Africa (18%; 95% CI, 11-24%), Europe (18%; 95% CI, 14-22%), and North and Central Americas (13%; 95% CI, 8-23%). A high prevalence was significantly associated with high geographical longitude (P = 0.04), low latitude (P = 0.02) and high relative environmental humidity (P = 0.04). This meta-analysis of data from published records indicates that public places are often heavily contaminated with eggs of Toxocara. This finding calls for measures to reduce the potential risk of infection and disease in humans.

Comparison of serum levels of IL-18 in peripheral blood of patients with type II diabetes with nephropathy clinical protests and patients with type II diabetes without nephropathy clinical protests

BACKGROUND AND AIM

Interleukin (IL)-18 is a proinflammatory cytokine secreted from mononuclear cells. Serum concentration of IL-18 is a strong predictor of death in patients with cardiovascular diseases. Recent studies have shown that microinflammation is involved in the pathogenesis of diabetic nephropathy as well as of cardiovascular diseases. This study aimed to test the hypothesis that the serum level of IL-18 is a common predictor of nephropathy and atherosclerosis in patients with type 2 diabetes.

MATERIALS AND METHODS

69 diabetic patient that have documented file in two centers (Ali asghar hospital and dialysis center of Imam ali hospital) had selected. 32 patients with type 2 nephropathic diabetes and 37 age- and sex-matched control subjects with type 2 diabetes that haven't any sign and symptom of nephropathy were enrolled.then take 5 ml blood from peripheral veins. Patients with positive CRP were excluded(2 patients in control group and 1 patient in case group). We assessed measured serum IL-18 levels in all patients.

FINDINGS

Serum IL-18 levels were significantly elevated in patients with type 2 diabetes with nephropathy as compared with control subjects (serum IL-18 261.29±20.25 vs. 167.20±13.48 pg/ml, P<0.001. the all patients in case control have upper level of serum IL-18 vs the control group.

DISCUSSION AND CONCLUSIONS

Serum levels of IL-18 in nephropathic patient significantly rise and Serum levels of IL-18 might be a predictor factor of progression of diabetic nephropathy.

Evaluation of recombinant P23 protein as a vaccine for passive immunization of newborn calves against Cryptosporidium parvum

Cryptosporidiosis is a zoonotic protozoan disease that affects the gastrointestinal tract of animals and humans. Diarrhoea as the most important indication of the infection leads to high economic losses in livestock industries and is a life threatening infection in immunocompromised individuals. In the absence of the effective drugs, vaccine has an effective role in the prevention of infection. For this purpose we developed a vaccine utilizing recombinant P23 protein and immunized pregnant cows four times from 70 days to parturition every 2 weeks. After parturition, each calf received his dam colostrum and challenged with 1 × 10(7) Cryptosporidium parvum oocysts at 12 h of age. Results showed that in contrast with the control group, the antibody titre in the sera and first milking colostra of the immunized cows significantly increased and calves fed hyperimmune colostrum did not show cryptosporidiosis signs. Moreover, enriched colostrum not only reduced significantly the amount of oocyst excretion but also delayed its onset. Our study showed that recombinant P23 protein could be used for passive immunization of newborn calves against Cryptosporidium parvum.

The effect of glucose-coated gold nanoparticles on radiation bystander effect induced in MCF-7 and QUDB cell lines

Due to biocompatibility and relative non-toxic nature, gold nanoparticles (GNPs) have been studied widely to be employed in radiotherapy as radio-sensitizer. On the other hand, they may enhance radiation-induced bystander effect (RIBE), which causes radiation adverse effects in non-irradiated normal cells. The present study was planned to investigate the possibility of augmenting the RIBE consequence of applying glucose-coated gold nanoparticles (Glu-GNPs) to target cells. Glu-GNPs were synthesized and utilized to treat MCF7 and QUDB cells. The treated cells were irradiated with 100 kVp X-rays, and their culture media were transferred to non-irradiated bystander cells. Performing MTT cellular proliferation test and colony formation assay, percentage cell viability and survival fraction of bystander cells were determined, respectively, and were compared to control bystander cells which received culture medium from irradiated cells without Glu-GNPs. Glu-GNPs decreased the cell viability and survival fraction of QUDB bystander cells by as much as 13.2 and 11.5 %, respectively (P < 0.02). However, the same end points were not changed by Glu-GNPs in MCF-7 bystander cells. Different RIBE responses were observed in QUDB and MCF7 loaded with Glu-GNPs. Glu-GNPs increased the RIBE in QUDB cells, while they had no effects on RIBE in MCF7 cells. As opposed to QUDB cells, the RIBE in MCF7 cells did not change in the dose range of 0.5-10 Gy. Therefore, it might be a constant effect and the reason of not being increased by Glu-GNPs.

The correlation between Toxoplasma gondii infection and prenatal depression in pregnant women

Previous studies have demonstrated that latent toxoplasmosis is associated with neuropsychiatric disorders. We evaluated the correlation between Toxoplasma gondii infection and prenatal depression. In this case-control study, we enrolled 116 depressed pregnant women and 244 healthy controls. The Edinburgh Postpartum Depression Scale (EPDS) was used to evaluate the depression symptom severity in study participants. All participants were screened for the anti-Toxoplasma IgG by enzyme-linked immunosorbent assay. Seroprevalence of T. gondii did not significantly differ between the depressed pregnant women and healthy controls (OR = 1.4; 95 % CI = 0.9-2.19; P = 0.142). T. gondii IgG titer was significantly higher in depressed women (18.6 ± 10.9 IUs) than those in the control group (13.6 ± 8.1 IUs) (z = -5.36, P < 0.001). The T. gondii-positive depressed women showed a positive correlation of T. gondii IgG titer with the EPDS scores (r = 0.52; P < 0.01). The mean EPDS score was also significantly higher in the T. gondii-positive depressed women (20.7 ± 2.7) compared with the controls (18.36 ± 2.7) (P < 0.001). The results obtained from the current study revealed that T. gondii infection might affect susceptibility to depression and severity of depressive symptoms in pregnant women, particularly in those patients who have high antibody titers. Further study is required to fully elucidate the characteristics and mechanisms of this association.

The Relationship between Optimism and Life Expectancy with Family Function among Parents with Disabled Children

This study was done aimed to investigate the relationship between optimism and life expectancy with family function among parents with disabled children in the city of Tehran. This research is descriptive by correlation method. Statistical population included all parents with disabled children in Tehran and the research sample consisted of 202 people. Sampling method was chosen based on available. The Spss software version 18 and correlation method and simultaneous multiple regression was used to analyze the data. Tools used include Family Assessment Device (FAD), scale Snyder hope, optimism questionnaire (LOT). The results showed that family performance with hope 0.49 and with optimism 0.48 has a meaningful relationship. In addition, optimism and hope can explain 0.09% of the variance spiritual well-being. It is suggested that to take actions order to help improving the performance of disabled parents.

Pulmonary hypertension and right ventricular failure in broiler chickens reared at high altitude is affected by dietary source of n-6 and n-3 fatty acids

The present study evaluated the development of pulmonary hypertension and right ventricular failure in broiler chickens reared at high altitude (2100 m) as affected by dietary intake of n-3 and n-6 fatty acid sources. Flax oil and soy oil were used as sources of n-3 and n-6 fatty acids, respectively, either with or without α-tocopheryl acetate. A total of 192 day-old broiler chicks (Ross 308) were used in a completely randomized design using isoenergetic and isonitrogenous experimental diets. Results showed that dietary flax oil significantly (p < 0.05) improved feed conversion ratio during 21-42 days of age. However, body weight gain did not significantly differ among the experimental groups in entire trial. Birds received flax oil had significantly higher serum concentration of nitric oxide (NO) but they had lower serum concentration of malondialdehyde when compared with their counterparts fed with soy oil. Liver and abdominal fat weights were significantly (p < 0.05) reduced by substitution of soy oil for flax oil. The right-to-total ventricle weight ratio (RV/TV) and mortality from pulmonary arterial hypertension (PAH) were significantly (p < 0.05) decreased in birds that received flax oil. In conclusion, n-3 fatty acids could significantly reduce RV:TV and PAH mortality in birds by increasing circulatory level of NO and suppressing hepatic lipogenesis.

Practical parasitology courses and infection with intestinal parasites in students

Students who are working in research or educational laboratories of parasitology, as well as health care workers providing care for patients, are at the risk of becoming infected with parasites through accidental exposure. The main purpose of this study was to identify potential positive cases of intestinal parasitic infections among students who took practical parasitology courses compared with students who did not take any practical parasitology courses in Lorestan University of Medical Sciences, Khorramabad, Iran, in 2013-2014. A total of 310 subjects from various majors were invited to voluntarily participate in the study. Various demographic data were collected using questionnaires. Three stool samples were collected from each individual on alternate days. Saline wet mounts (SWM), formalin-ether sedimentation test (FEST), Sheather floatation test (SHFT) and trichrome and modified Ziehl-Neelsen staining methods were used to diagnose the presence of intestinal parasites. The prevalence rate of intestinal parasites (IPs) among the students was 11.93%. There was a significant difference between majors in the infection with IPs (P<0.05). The most frequently observed IPs were Blastocystis hominis (4.51%) and Giardia intestinalis (3.54%). The results of this study showed that the transmission of pathogenic parasites in the educational course of practical parasitology could occur and must be taken into careful consideration.

Silver- and fluoride-containing mesoporous bioactive glasses versus commonly used antibiotics: Activity against multidrug-resistant bacterial strains isolated from patients with burns

The wound healing process is frequently associated with a number of major clinical challenges, due to the failure of commonly used antibiotics as a remedy for wounds. There have always been fascinating questions about the novel applications of bioactive glasses (BGs) and it is expected that in the next few years these types of materials may play an important role in many aspects of soft tissue regeneration. This research focuses on the feasibility of using silver- and fluoride-containing BGs against multidrug-resistant bacterial strains isolated from patients with burns. According to the results obtained, fluoride did not exhibit antibacterial activity against the tested bacteria, while both 1% and 2% silver-containing BGs inhibited the bacterial growth. It is an important finding that 1% silver-containing BGs showed a potential antibacterial activity without any toxicity against fibroblasts, suggesting that this class of BGs could play a key role in the prevention of infection, reduction of pain, and removal of excessive exudates.

Fabrication of fast mid-infrared range photodetector based on hybrid graphene-PbSe nanorods

Weak light absorption of graphene has limited the responsivity of graphene-based photodetectors. On the other hand, the slow response of PbSe as a mid-infrared range (MIR) detector makes this type of detector unsuitable as a commercial detector. Here, we report a fast MIR detector based on hybrid graphene-PbSe nanorods. For this purpose, a few-layer graphene piece was synthesized using a simple, scalable, and economical method on a cobalt layer, the synthesized graphene was transferred onto interdigitated copper electrodes, and then synthesized nanorods were spin coated on the transferred graphene. Strong and tunable light absorption in the quantum dot layer creates electric charges, which are transferred to the graphene, and due to the high charge mobility of graphene and long trapped-charge lifetimes in the quantum dot layer, they recirculate many times. The fabricated device has high speed and responsivity. The gain of fabricated detectors based on hybrid graphene quantum dots is 10.3 times more, their response time is 14.3 times faster, and their responsivity is 10 times more than conventional nanorod-based detectors. From the point of view of spectral selectivity, tuning the size of the nanorods helps optical detection from the IR to mid-IR.

Apoptotic cell-treated dendritic cells induce immune tolerance through specifically facilitating development of CD4+ effector memory T cells (IRC10P.408)

CD4+ memory T cells play an important role in induction of autoimmunity and chronic inflammatory responses. However, regulatory mechanisms of CD4+ memory T cell-mediated inflammatory responses are poorly understood. Here we showed that apoptotic cell-treated dendritic cells inhibit development and differentiation of CD4+ effector and central memory T cells in vitro and in vivo. Simultaneously, i.v. transfer of apoptotic T cell-induced tolerogenic dendritic cells can block development of experimental autoimmune encephalomyelitis (EAE), an inflammatory disease in central nervous system of C57BL/6J mouse. However, our results imply that it is effector memory CD4+ T cells, not central memory CD4+ T cells which play a major role in chronic inflammatory responses in mice with EAE. I.v. transfer of tolerogenic dendritic cells induced by apoptotic T cells leads to immune tolerance through specifically blocking development of CD4+ effector memory T cells compared with results of EAE control mice. Our results reveal a new mechanism of apoptotic cell-treated dendritic cell-mediated immune tolerance in vivo.

Expression of GM-CSF in T cells is increased in multiple sclerosis and is suppressed by IFN-β therapy (BA11P.136)

Multiple sclerosis (MS) is an autoimmune disease of the central nervous system (CNS). Studies in animal models of MS have shown that granulocyte-macrophage colony-stimulating factor (GM-CSF) produced by T cells is necessary for development of autoimmune CNS inflammation. This suggests that GM-CSF may have a pathogenic role in MS as well. The objective of this study was to characterize GM-CSF production by T cells of MS patients, and to determine the effect of interferon-beta (IFN-β) therapy on its production. GM-CSF production by peripheral blood (PB) T cells and the effects of IFN-β were characterized in samples of untreated and IFN-β-treated MS patients vs. healthy subjects. GM-CSF production by T cells in MS brain lesions was analyzed by immunofluorescence. Untreated MS patients had significantly greater numbers of GM-CSF+ CD4+ and CD8+ T cells in PB compared to healthy controls and IFN-β-treated MS patients. IFN-β strongly suppressed GM-CSF production by T cells in vitro. A number of CD4+ and CD8+ T cells in MS brain lesions expressed GM-CSF. Elevated GM-CSF production by PB T cells in MS is indicative of aberrant hyperactivity of the immune system. Given its essential role in animal models, abundant GM-CSF production at the sites of CNS inflammation suggests that GM-CSF contributes to MS pathogenesis. Our findings also reveal a potential mechanism of IFN-β therapy, namely suppression of GM-CSF production.

Galectin-1 plays an essential role in intravenous tolerance in experimental autoimmune encephalomyelitis (BA4P.139)

Multiple sclerosis and its animal model, experimental autoimmune encephalomyelitis (EAE), are inflammatory demyelinating diseases of the central nervous system (CNS). EAE can be induced by immunizing mice with myelin oligodendrocyte glycoprotein-derived peptide, MOG35-55, in adjuvant. It has been previously demonstrated that intravenous (i.v.) injection of MOG35-55 post immunization induction suppresses disease development, a phenomenon called i.v. tolerance. The glycan-binding protein galectin-1, produced primarily by regulatory T cells plays an immunoregulatory role in EAE by inducing tolerogenic DCs and IL-10-producing regulatory type 1 T cells (Tr1). To examine the role of galectin-1 in i.v. tolerance, we administered MOG35-55 peptide i.v. to wild-type (WT) and galectin-1-/- (Gal1-/-) mice with ongoing EAE. MOG35-55 rapidly suppressed disease in the WT, but not in the Gal1-/- mice. Expression of pro-inflammatory cytokines IFN-gamma and IL-17A were reduced in the CNS and periphery of tolerized WT mice, while the number of Tr1 cells increased in the periphery. In contrast, i.v. MOG35-55 significantly increased IFN-gamma and IL-17A in the CNS and periphery of Gal1-/-mice and these mice had markedly fewer Tr1 cells in the periphery. Our data suggest that galectin-1 mediated i.v. tolerance induction is dependent on the downregulation of Th1 and Th17 pro-inflammatory responses, and enhanced development of Tr1 cells.

Prevalence of intestinal parasite infections and associated clinical symptoms among patients with end-stage renal disease undergoing hemodialysis

PURPOSE

Intestinal parasitic infections (IPIs) can result in high morbidity and mortality, particularly in immunocompromised patients. Infectious diseases are among the main causes of death in end-stage renal disease (ESRD) patients due to their impaired immune systems. The aim of this study was to determine the prevalence IPIs and their associated symptoms in ESRD patients.

METHODS

In this case-control study, the fecal samples of 78 ESRD patients undergoing hemodialysis and 140 controls without any kidney problems were analyzed for intestinal parasites using direct-smear, formol-ether and modified Ziehl-Neelsen staining techniques.

RESULTS

The difference in the prevalence of IPIs between ESRD patients (30.7 %) and the control group (10.7 %) was significant (OR = 3.7; 95 % CI = 1.8-7.61; P < 0.001). Blastocystis (14.1 %) and Cryptosporidium spp.(11.5 %) were the most common IPIs detected in ESRD patients, and the presence of Cryptosporidium spp. was significantly associated with diarrhea in ESRD patients (OR = 16; 95 % CI = 1.54-166.05; P < 0.05). Leukocytosis, diarrhea, weight loss, nausea/vomiting and bloating were also significantly higher in the hemodialysis group when compared with the control group.

CONCLUSION

The current study revealed a high prevalence of intestinal parasites and related clinical symptoms in ESRD patients undergoing hemodialysis. Since hemodialysis patients are immunocompromised and intestinal parasites can cause serious clinical complications, we suggest that stool examination for intestinal parasites, with an emphasis on detection of Cryptosporidium spp. and Blastocystis, should be incorporated into the routine clinical care for these patients. Measures for preventing the acquisition of IPIs are also recommended.

Immunotherapy using lipopolysaccharide-stimulated bone marrow-derived dendritic cells to treat experimental autoimmune encephalomyelitis

Lipopolysaccharide (LPS) produced by Gram-negative bacteria induces tolerance and suppresses inflammatory responses in vivo; however, the mechanisms are poorly understood. In this study we show that LPS induces apoptosis of bone marrow-derived dendritic cells (DCs) and modulates phenotypes of DCs. LPS treatment up-regulates expression of tolerance-associated molecules such as CD205 and galectin-1, but down-regulates expression of Gr-1 and B220 on CD11c(+) DCs. Moreover, LPS treatment regulates the numbers of CD11c(+) CD8(+) , CD11c(+) CD11b(low) and CD11c(+) CD11b(hi) DCs, which perform different immune functions in vivo. Our data also demonstrated that intravenous transfer of LPS-treated DCs blocks experimental autoimmune encephalomyelitis (EAE) development and down-regulates expression of retinoic acid-related orphan receptor gamma t (ROR-γt), interleukin (IL)-17A, IL-17F, IL-21, IL-22 and interferon (IFN)-γ in myelin oligodendrocyte glycoprotein (MOG)-primed CD4(+) T cells in the peripheral environment. These results suggest that LPS-induced apoptotic DCs may lead to generation of tolerogenic DCs and suppress the activity of MOG-stimulated effector CD4(+) T cells, thus inhibiting the development of EAE in vivo. Our results imply a potential mechanism of LPS-induced tolerance mediated by DCs and the possible use of LPS-induced apoptotic DCs to treat autoimmune diseases such as multiple sclerosis.

Investigation of MMP-2 and MMP-9 activities in canine sera with dilated cardiomyopathy

Dilated cardiomyopathy (DCM) is accompanied by myocytes and connective tissue changes. Matrix metalloproteinases (MMPs) play important roles in cardiac remodeling. It seems that the gelatinases (MMP-2 and MMP-9) are effective enzymes in cardiomyopathy. Dilated cardiomyopathy was confirmed in 22 dogs (patient group) including 11 female and 11 male by clinical examination, auscultation, thoracic radiography and echocardiography. 17 healthy dogs (control group) with similar weight and breed to patients were also selected from referred cases to Small Animal Hospital of the Veterinary Faculty of Tehran University and the same diagnostic procedures were performed on them. After that, serum MMP-2 and MMP-9 of control and patient groups were measured by semi-quantitative zymography. Semiquantitative analysis of zymograms from canine serums with DCM showed that total MMP-9 in patients is more than control group, while there was no significant difference in total MMP-2 between the two groups. Pro-MMP-2 was not detected in patient group but its active form was present in both groups, of course MMP-2 activity in patients was significantly more than control. Active form of MMP-9 was detected only in patients. Although pro-MMP-9 was present in both groups, its level in control group was significantly higher than patients. The heart enlargement was observed in the left, right or both parts. Statistically significant differences in active form of MMP-2 and MMP-9 levels were observed between different groups of heart enlargement (right, left and both parts) compared to control but this difference was not significant considering chambers affected and VHS (vertebral heart score) groups. In conclusion, although there are some changes in serum MMP-2 and MMP-9 levels in canine DCM, it seems that increase of MMP-9 is more prominent than MMP-2 and neither of them were affected by heart enlargement or VHS grade.

Evaluation of modified Ziehl-Neelsen, direct fluorescent-antibody and PCR assay for detection of Cryptosporidium spp. in children faecal specimens

To determine the sensitivity and specificity of routine screening methods for cryptosporidiosis, three methods including conventional modified Ziehl-Neelsen (MZN), direct fluorescent-antibody (DFA) and Nested-PCR assay compared together. To this end, their ability to identify the low concentrations of Cryptosporidium spp. oocysts in children fecal samples was evaluated. The sample population of this study was children under 12 years old who had diarrhea and referred to pediatric hospitals in Tehran, Iran. 2,510 stool specimens from patients with diarrhea were screened for Cryptosporidium oocysts by concentration method and MZN. To determine sensitivity and specificity, Nested-PCR and DFA were performed on 30 positive and 114 negative samples which previously had been proved by MZN. By using the microscopic method, DFA assay and PCR analysis, a total of 30 (1.2 %), 28 (1.1 %) and 32 (1.27 %) positive samples were detected respectively. According to the results, the sensitivity, specificity, and positive and negative predictive values of the Nested-PCR assay were 100 %, compared to 94, 100, 100, and 98 %, respectively, for MZN and 87.5, 100, 100, and 96 %, respectively, for DFA. Results of the present study showed that the Nested-PCR assay was more sensitive than the other two methods and laboratories can use the Nested-PCR method for precise diagnosis of Cryptosporidium spp. However, regarding the costs of Nested-PCR and its unavailability in all laboratories and hospitals, MZN staining on smears has also enough accuracy for Cryptosporidium diagnosis.

Effective, appropriate and simple culture, egg hatching and cryopreserving of the nematode Cheilospirura hamulosa

1. Successful invasion by nematode parasites is associated with several factors including egg hatching at the right time in their hosts. To determine a simple and appropriate medium for culture and egg hatching of the highly pathogenic species of the Acuariidae family, Cheilospirura hamulosa were cultured in three different media. In addition the viability of C. hamulosa eggs was determined after storage in frozen infected gizzards. 2. Eggs removed from the uteri of the female worms in infected gizzards were pooled and washed in distilled water and screened under a stereo dissecting microscope. Eggs were counted and cultured in three different media, nutrient agar, normal saline 0.9% and Bearman, at room temperature. Additionally, 10 infected gizzards were kept at -20°C for 2 and 8 months. 3. After 4-5 d there had been no growth in the nutrient agar medium, whereas 11% of the cultured eggs in the Bearman medium contained larvae 2-3 d after culturing. In 0.9% normal saline medium the two polar knobs appeared on the two poles of the eggs at 2 d post cultivation, and 74% of the eggs contained a larva on the third day. Mature larvae gradually exited from the eggs. 4. Eggs collected from female worms in gizzards frozen at -20°C were cultured in the same three culture media at room temperature. Larvae were visible in the eggs after 2-3 d in the Bearman and 0.9% normal saline media and hatched thereafter. 5. The 0.9% normal saline medium is recommended for egg hatching and cultivation of C. hamulosa due for simplicity, efficacy and cost effectiveness. Moreover, freezing of the infected gizzards at -20°C is proposed for long-term storage of the eggs.

Tolerogenic dendritic cells produced by lentiviral-mediated CD40- and interleukin-23p19-specific shRNA can ameliorate experimental autoimmune encephalomyelitis by suppressing T helper type 17 cells

Down-regulation of soluble or membrane-bound co-stimulatory molecules by RNAi in dendritic cells can prevent the activation of immune responses. Therefore, this study was designed to evaluate the therapeutic efficacy of bone marrow-derived DCs (BMDCs) transduced with lentiviral vectors to permanently expressed shRNA specific for CD40 (CD40LV-DCs) and/or p19 subunit of interleukin (IL)-23 (p19LV-DCs) mRNAs in experimental autoimmune encephalomyelitis (EAE). In-vitro studies showed that double-transduced BMDCs (CD40(+) p19LV-DCs) resemble tolerogenic DCs due to profound down-regulation of CD40, lower expression of proinflammatory cytokines (IL-6 and IL-12), increased IL-10 production and stronger stimulation of myelin oligodendrocyte glycoprotein (MOG)35-55 -specific T cells for production of IL-10 compared with CD40LV-DCs, p19LV-DCs and BMDCs transduced with control lentiviral vector (CoLV-DCs). Moreover, injection of transduced CD40(+) p19LV- BMDCs in EAE mice resulted in more reduction in clinical score, significant reduction in IL-17 or increased production of IL-10 by mononuclear cells derived from the lymph nodes or spinal cord compared with CoLV-DCs-treated EAE mice. In conclusion, simultaneous knock-down of CD40 and IL-23 production by BMDCs may represent a promising therapeutic tool for the treatment of IL-17-dependent autoimmune diseases, including multiple sclerosis.

Self-consistent performance modeling for dual band MIS UV photodetectors based on Si/SiO2 multilayer structure

In this paper, we present a self-consistent theoretical model for a metal-insulator semiconductor (MIS) dual band ultraviolet (UV) photodetector with a modified structure implying an arbitrarily defined insulating potential barrier as its active region. Utilizing our proposed model, the dark and photocurrent density-voltage (J-V) characteristics of MIS UV photodetectors with multi-quantum wells of silicon (MQWs) are calculated. We demonstrate that dark current is reduced in the suggested structure, because the electron-tunneling probability becomes unity at energies coincident with the peak detection wavelength. This is due to the resonant tunneling and decreases at energies that are significantly smaller than this optimum value. In consequence, the number of carriers contributing to the dark current, which have a broad energy distribution at high temperatures, will decrease. It is also shown that the designed structure could detect two individual UV wavelengths, simultaneously. The width of each Si quantum well has been considered at around 1.2 nm, in order to observe these two absorption peaks in the middle and near UV regions of photon spectrum (about 365 nm, 175 nm).

T- and Y-splitters based on an Au/SiO2 nanoring chain at an optical communication band

In this paper, we have utilized Au nanoring chains in an SiO2 host to design certain T-and Y-structures, and expanded it to transport and split the electromagnetic energy in integrated nanophotonic devices operating at an optical communication band (λ≈1550 nm). We compared two structures and tried to choose the best one, with lower losses and higher efficiency at the output branches, in order to split and transport the optical energy. Comparing the different types of nanoparticles corroborates that nanorings have an extra degree of tunability in their geometrical components. Meanwhile, nanorings show strong confinement in near-field coupling, less extinction coefficient, and also lower scattering into the far field during energy transportation at the C-band spectrum. Due to the nanoring's particular properties, transportation losses would be lower than in other nanoparticle-based structures like nanospheres, nanorods, and nanodisks. We demonstrate that Au nanorings surrounded by an SiO2 host yield suitable conditions to excite surface Plasmons inside the metal. Comparison between Y-and T-splitters shows that the Y-splitter is a more suitable alternative than the T-splitter, with higher transmission efficiency and lower losses. In the Y-structure, the power ratio (time-averaged power across the surface) is 24.7%, and electromagnetic energy transportation takes place at group velocities in the vicinity of 30% of the velocity of light; transmission losses are γT=3 dB/655 nm and γT=3 dB/443 nm. In this work, we have applied the finite-difference time-domain method (FDTD) to simulate and indicate the properties of structures.

Accelerated thymocyte maturation in IL-12Rβ2-deficient mice contributes to increased susceptibility to autoimmune inflammatory demyelination

IL-12Rβ2(-/-) mice, which are unresponsive to IL-12, develop severe experimental autoimmune encephalomyelitis (EAE). The mechanisms for enhanced autoimmunity are incompletely understood. We report that in IL-12Rβ2(-/-) mice, thymocytes undergo markedly accelerated maturation. This occurs at the transition from a double positive (DP) to a single positive (SP) phenotype, resulting in higher numbers of CD4 and CD8 SP cells, and to a lesser extent at the transition from double negative (DN) to DP cells. Accelerated maturation is observed in mice injected with anti-CD3 to mimic pre-T-cell receptor stimulation, and also in mice immunized with myelin oligodendrocyte glycoprotein (MOG) peptide to induce EAE.

The role of N53Q mutation on the rat mu-opioid receptor function

Glycosylation of the mu-opioid receptor may play an important role on its function. Using nested PCR, N53Q mutation was prepared in the N-terminal region of the rat mu-opioid receptor cDNA and cloned into the pcDNA3 vector. The plasmids containing the wild-type and mutated receptor cDNA were transfected into the COS-7 cells. Intracellular cAMP was measured in the morphine-treated and untreated transfected cells using an ELISA kit. Plasmid expression was evaluated using X-gal staining. Intracellular concentration of cAMP in the N53Q-mutated cells was not significantly different from the wild-type. The expression of the transfected plasmids was confirmed. Therefore, based on these results, it seems that glycosylation at the N53 site of the rat mu-opioid receptor does not influence the function of this receptor significantly.

Ultrafast low-threshold all-optical switch implemented by arrays of ring resonators coupled to a Mach-Zehnder interferometer arm: based on 2D photonic crystals

Using an array of m x n nonlinear ring resonators (m = 1, 3, 5, and n = 1, 2, 3) coupled to the upper arm of a Mach-Zehnder interferometer (MZI), we have proposed an all-optical switch structure. Using a 5 x 3 array, we have shown the possibility of designing an all-optical switching device with a threshold intensity as low as 15 mW/m(2) and switching window of approximately 35 ps. While using m x 1 arrays, we have achieved switching windows smaller than 10 ps, at the expense of higher switching thresholds, ranging from 37 to 55 mW/m(2). The whole structure is based on a square lattice photonic crystal of lattice constant a = 600 nm, formed by rods of radius r = 90 nm in an air background. The linear rods' refractive index is taken to be the same as that of Si(0.75)Ge(0.25); i.e., n(r) = 3.6, whereas the nonlinear rod's refractive index and Kerr index parameter are taken to be n(0) = 1.4 and n(2) = 10(-14) m(2)/W. The center wavelength at which the nonlinear rings are designed to make the resonance is taken to be lambda(0) = 1550 nm in free space.

Proposal for ultra-high performance infrared quantum dot

In this paper, effect of an introduced defect on electrical and optical properties of quantum box and spherical quantum dot is studied. 3D-self-consistent solution of the Schrödinger-Poisson equations for evaluation of the proposed complex quantum box and analytical solution for spherical quantum dot are used. It is shown that with increasing the defect size and height a considerable enhancement in matrix element, optical nonlinearities (second order, quadratic electro-optic effect and the resonant third order nonlinear susceptibilities), optical linear absorption coefficient ( 4.5 -10 nm, 10(-4) approximately 10(-2) m.V(-1), 10(-12) approximately 10(-9) m(2) / V (2) , 10(-11) approximately 10(-9) m(2) / V(2) and 4.7 x 10(2) approximately 3.8 x 10(4) cm(-1) respectively) and electroabsorption properties associated with intersublevel transition of centered defect quantum dot are examined. Also, it is shown that enhancement of optical nonlinearity is approximately independent of defect position that is so excellent from practical implementation point of view. A THZ-IR photodetector based on resonant tunneling spherical centered defect quantum dot (RT-SCDQD) operating at room temperature is also investigated. Inserting the centered defect in quantum dot increases the dipole transition matrix element and so increases the absorption coefficient considerably (1.05 x 10(6) approximately 7.33 x 10(6)at 83 microm ). Therefore the quantum efficiency in SCDQD structure enhances which leads to increasing the responsivity of the proposed system. The double barrier reduces the dark current. These improvements concludes to ultra high detectivity 5 x 10(16) 2.25 x 10(9) cm Hz (1/2)/W at 83 and 300 degrees K at 83 microm respectively.

Narrowband DWDM filters based on Fibonacci-class quasi-periodic structures

In this paper, we propose a narrowband DWDM filter structure, whose reflection band characteristics, meets the ITU-T standard. The proposed filter structure is based on Fibonacci quasi-periodic structures composed of multilayers with large index differences. Studying the effects of the optical and geometrical parameters of Fibonacci quasi-periodic structures on its filtering properties, we have realized that to achieve the ITU-T standard, we need to cascade two successive structures both with the same generation numbers j=4 and orders n=25 and apodized refractive indices. The apodization process helps to minimize the stop band sidelobes. We have also demonstrated that beside Fibonacci's order, n, the layers dimensions, and their refractive index ratios are the main design parameters.

Motor neuron pathology in experimental autoimmune encephalomyelitis: studies in THY1-YFP transgenic mice

Using adult male C57BL/6 mice that express a yellow fluorescent protein transgene in their motor neurons, we induced experimental autoimmune encephalomyelitis (EAE) by immunization with myelin oligodendrocyte glycoprotein peptide 35-55 (MOG peptide) in complete Freund's adjuvant (CFA). Control mice of the same transgenic strain received CFA without MOG peptide. Early in the course of their illness, the EAE mice showed lumbosacral spinal cord inflammation, demyelination and axonal fragmentation. By 14 weeks post-MOG peptide, these abnormalities were much less prominent, but the mice remained weak and, as in patients with progressive multiple sclerosis, spinal cord atrophy had developed. There was no significant loss of lumbar spinal cord motor neurons in the MOG peptide-EAE mice. However, early in the course of the illness, motor neuron dendrites were disrupted and motor neuron expression of hypophosphorylated neurofilament-H (hypoP-NF-H) immunoreactivity was diminished. By 14 weeks post-MOG peptide, hypoP-NF-H expression had returned to normal, but motor neuron dendritic abnormalities persisted and motor neuron perikaryal atrophy had appeared. We hypothesize that these motor neuron abnormalities contribute to weakness in this form of EAE and speculate that similar motor neuron abnormalities are present in patients with progressive multiple sclerosis.

Mature bone marrow-derived dendritic cells polarize Th2 response and suppress experimental autoimmune encephalomyelitis

Distinct subsets of dendritic cells (DCs) based on the origin, phenotypes, and the nature of the signals that promote DC maturation can determine polarized immune responses of T cells. In this study, DCs were cultured from mouse bone marrow (BM) progenitors in granulocyte-macrophage colony-stimulating factor (GM-CSF). To generate mature DCs (mDCs), lipopolysaccharide (LPS) was used in the culture for 24 h. LPS-stimulated DCs were phenotypically mature, which exhibited strongly upregulated CD40, B7.1, and B7.2 compared to non-LPS-stimulated immature DCs (imDCs). Both mDCs and imDCs expressed high levels of MHC class II but low level of CD54. mDCs produced higher levels of IL-10 and lower IL-12 compared to imDCs. No IFN-gamma or IL-4 was found in both groups. When mDCs were injected intraperitoneally (i.p.) to the mice with experimental autoimmune encephalomyelitis (EAE), the severity of clinical signs and inflammation in the CNS was significantly suppressed compared to imDC-injected mice (p<0.01) and PBS-injected mice (p<0.02). Moreover, lymphocytes from mDC-injected mice produced lower level of IL-12, IFN-gamma, but higher level of IL-10, compared to imDC-injected and non-DC-injected mice. We conclude that BM-mDCs, but not BM-imDCs, promote Th2 differentiation and have the potential for suppression of inflammatory demyelination.