A model of acute renal allograft rejection in outbred Yorkshire piglets

Pigs represent a desirable animal model for the study of rejection in kidney transplantation with inbred Yucatan miniature swine (YMS) the most commonly studied strain due to well defined swine leukocyte antigen (SLA) genotypes. However, limitations to YMS may include cost and availability. Outbred Yorkshire pigs are widely available and significantly cheaper than YMS. Recent advances in SLA genotyping have allowed its application to outbred strains. On this basis, we theorized that Yorkshire pigs would be a viable alternative to YMS for the study of rejection in kidney transplantation. To address this question, we performed auto (Auto) and allotransplants (Allo) in 24 Yorkshire pigs, and assessed SLA genotypes and acute rejection after 72h. At sacrifice, and when compared to autotransplants, allotransplants had significant elevations in serum creatinine (8.4±1.3 vs 2.8±2.0mg/dL for Allo vs autotransplants, respectively) and BUN (61±9 vs 19.2±15mg/dL for Allo vs autotransplants, respectively). Warm ischemia times between the two groups did not differ (24±2.3 vs 26.4±1.4min for Auto vs Allo, respectively). There were 16 distinct SLA haplotypes identified from pigs undergoing allotransplantion, no matched donor-recipient pairs, and all allografts demonstrated rejection. Type IIA cellular rejection (Banff) was the most common. One allograft demonstrated hyperacute rejection due a blood group incompatibility. Histologically, the expression of regulatory Tcells and dendritic cells was increased in allografts. These data suggest that Yorkshire pigs may be a useful model for the study of acute rejection in experimental kidney transplantation.

Abstract P5-01-01: Real-time imaging of lymph node metastasis in response to systemic ezrin inhibitor treatment in breast cancer

Lymph node (LN) metastasis is a key driver of recurrence and survival in breast cancer (BC) patients. However, the mechanisms of metastatic dissemination of tumour cells from LNs to distant sites and their predictors of response to systemic therapy remain poorly understood, mainly due to a lack of non-invasive in vivo imaging models. We have recently described ezrin, a pro-metastatic crosslinker protein, as a regulator of tumour lymphangiogenesis and metastasis in BC (Breast Cancer Res. 2014; 16(5): 438). Furthermore, we demonstrated significant association of high ezrin expression with lymphovascular invasion in a cohort (n=63) of premenopausal patients with invasive BC (p =0.024). These findings prompted us to examine the role of ezrin in migration and invasion of metastatic tumour cells in LNs and their response to ezrin-targeted therapy. Using a locally accrued LN positive patient cohort (n=94), we demonstrated a significant association between high ezrin levels and reduced recurrence-free survival (univariate Log-rank test, p=0.033), suggesting that ezrin is a potential predictor of relapse in LN positive BC. To address the mechanistic role of ezrin in LN metastasis, we developed a novel intravital imaging model using a lymphatic reporter transgenic mouse (B6-prox1-mOrange2-pA-BAC) to examine the response of tumour-draining LN to anti-ezrin systemic therapy in real time. Next, we tested the effects of a small molecule ezrin inhibitor (NSC668394) in vitro and observed significant suppression of ezrin activation (p-T567) and cancer cell invasive phenotype. Intravital imaging of inguinal LN metastases, derived from subcutaneously implanted breast adenocarcinoma E0771-LMV (lung metastatic variant) cells, demonstrated significant reduction in mobility and invasiveness (Mann Whitney, p<0.0001) of metastatic cells following systemic treatment with NSC668394 (0.5 mg/kg at 24h and 8h prior to imaging). Interestingly, LN metastases engagement by host T cell (CD3+) was notably increased, whereas T cell mobility was not affected by ezrin inhibition. Our findings present a novel non-invasive imaging model to study the LN metastasis response to anti-cancer therapy in real time, and provide new insight into the role of ezrin as a potential anti-metastatic target in BC.

(Supported by CRS, CIHR, CBCF, BCAK, Queen's SRC).

Citation Format: Ghaffari A, Hoskin V, Mullins G, Greer P, Kiefer F, Madarnas Y, SenGupta S, Elliott B. Real-time imaging of lymph node metastasis in response to systemic ezrin inhibitor treatment in breast cancer. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P5-01-01.

Indoleamine 2,3-dioxygenase inhibition alters the non-coding RNA transcriptome following renal ischemia-reperfusion injury

BACKGROUND

Indoleamine 2,3 dioxygenase (IDO) degrades the essential amino acid tryptophan and has been shown to minimize rejection in animal models of renal transplantation. Ischemia-reperfusion injury (IRI) is unavoidable in renal transplantation and correlates with shorter graft survival times. Despite its favorable effects on rejection, there is evidence that IDO may facilitate renal IRI. Differentiating the negative impact of IDO on IRI from its pro-tolerant effects in allograft rejection is of clinical relevance. In these studies we hypothesized that constitutive IDO activity may influence renal genes associated with recovery from IRI, and that IDO inhibition may unmask these effects.

METHODS

We examined the renal transcriptome in a rat model of IRI with and without IDO inhibition with 1-methyl-d-tryptophan (1-MT), and assessed for alterations in the gene expression signature.

RESULTS

These studies demonstrated that during recovery from renal IRI, pre-treatment with 1-MT alleviated alterations in 105 coding sequences associated with IRI, and in turn triggered new changes in 66 non-coding transcripts, the majority of which were represented by small nucleolar RNA.

CONCLUSION

These results suggest a biologic role for non-coding, IDO-dependent genes in regulating the early response to IRI.

Parametric modelling of cardiac system multiple measurement signals: an open-source computer framework for performance evaluation of ECG, PCG and ABP event detectors

The major focus of this study is to present a performance accuracy assessment framework based on mathematical modelling of cardiac system multiple measurement signals. Three mathematical algebraic subroutines with simple structural functions for synthetic generation of the synchronously triggered electrocardiogram (ECG), phonocardiogram (PCG) and arterial blood pressure (ABP) signals are described. In the case of ECG signals, normal and abnormal PQRST cycles in complicated conditions such as fascicular ventricular tachycardia, rate dependent conduction block and acute Q-wave infarctions of inferior and anterolateral walls can be simulated. Also, continuous ABP waveform with corresponding individual events such as systolic, diastolic and dicrotic pressures with normal or abnormal morphologies can be generated by another part of the model. In addition, the mathematical synthetic PCG framework is able to generate the S4-S1-S2-S3 cycles in normal and in cardiac disorder conditions such as stenosis, insufficiency, regurgitation and gallop. In the PCG model, the amplitude and frequency content (5-700 Hz) of each sound and variation patterns can be specified. The three proposed models were implemented to generate artificial signals with varies abnormality types and signal-to-noise ratios (SNR), for quantitative detection-delineation performance assessment of several ECG, PCG and ABP individual event detectors designed based on the Hilbert transform, discrete wavelet transform, geometric features such as area curve length (ACLM), the multiple higher order moments (MHOM) metric, and the principal components analysed geometric index (PCAGI). For each method the detection-delineation operating characteristics were obtained automatically in terms of sensitivity, positive predictivity and delineation (segmentation) error rms and checked by the cardiologist. The Matlab m-file script of the synthetic ECG, ABP and PCG signal generators are available in the Appendix.

A methodology for prediction of acute hypotensive episodes in ICU via a risk scoring model including analysis of ST-segment variations

The aim of this study is to detect Acute Hypotensive Episodes (AHE) and Mean Arterial Pressure Dropping Regimes (MAPDRs) using ECG signal and Arterial Blood Pressure waveforms. To meet this end, the QRS complexes and end-systolic end-diastolic pulses are first extracted using two innovative Modified Hilbert Transform-Based algorithms namely as ECGMHT and BPMHT. A new smoothing algorithm is next developed based on piecewise polynomial fitting to smooth the fast fluctuations observed in RR-tachogram, systolic blood pressure (SBP) and diastolic blood pressure (DBP) trends. Afterwards, in order to consider the mutual influence of parameters on the evaluation of shock probability, a Sugeno Adaptive Network-based Fuzzy Inference System-ANFIS is trained using Hasdai et al. (J Am Coll Cardiol, 35: 136–143, 2000) parameters as input, with appropriate membership functions for each parameter. Using this network, it will be possible to incorporate the possible mutual influences between risk parameters such as heart rate, SBP, DBP, ST-segment episodes, age, gender, weight and some miscellaneous factors to the calculation of shock occurrence probability. In the next step, the proposed algorithm is applied to 15 subjects of the MIMIC II Database and AHE and MAPDRs (MAP ≤ 60 mmHg with a period of 30 min or more) are identified. As a result of this study, for a sequence of MAPDRs as long as 20 min or more, there will exist a consequent high peak with the duration of 3–4 min in the corresponding probability of cardiogenic shock diagram.

Parallel processing of ECG and blood pressure waveforms for detection of acute hypotensive episodes: a simulation study using a risk scoring model

The aim of this study is to detect acute hypotensive episodes (AHE) and mean arterial pressure dropping regimes (MAPDRs) using electrocardiographic (ECG) signals and arterial blood pressure waveforms. To meet this end, the QRS complexes and end-systolic end-diastolic pulses are first extracted using two innovative modified Hilbert transform-based algorithms, namely ECGMHT and BPMHT. The resulting systolic and diastolic blood pressure pulses are then used to calculate the MAP trend. A new smoothing algorithm is developed, next based on piecewise polynomial fitting (PPF) to smooth the fast fluctuations observed in RR-tachogram and MAP trends. PPF algorithm operates by sequentially fitting N number of polynomials to the original signal and calculating the corresponding coefficients using the best linear unbiased estimation approach. In the next step, the proposed algorithm is applied to 15 subjects of the MIMIC II Database and AHE and MAPDRs (MAP ≤ 60 mmHg with a period of 30 min or more) are identified. As a result of this study, MAPDR is realised as a specific marker of cardiogenic shock, in that for a sequence of MAPDRs as long as 20 min or more, there will exist a consequent high peak with a duration of 3-4 min in the corresponding probability of cardiogenic shock diagram.

Predicting acute hypotensive episodes based on HR baroreflex model estimation

A new method to predict acute hypotensive episodes (AHE) is proposed in this paper. The AHE is defined as any period of 30 min or more during which at least 90% of mean arterial pressure (MAP) measurements are below 60 mmHg. Since arterial pressure has a direct correlation with heart rate through heart rate (HR) baroreflex and cardiovascular systems, any changes in MAP, directly affect HR and vice versa. Predicting HR using our developed model, the periods in which HR drops to the values less than 40 beat/min are detected. The demonstrated AHE data for twenty patients are picked to validate the proposed algorithm. Results show that the proposed method could truly predict occurrence of the AHE in 17 out of 20 cases analyzed. Results show reliable accuracy in predicting AHE in these patients.

Simultaneous spectrophotometric determination of paracetamol, phenylephrine and chlropheniramine in pharmaceuticals using chemometric approaches

BACKGROUND AND THE PURPOSE OF THE STUDY

The linear multivariate calibration models such as principal components regression (PCR) and partial least squares regressions (PLS1 and PLS2) due to the mathematical simplicity and physical or chemical interpretability are sufficient and generally preferred method for analysis of multicomponent drugs. In this study, simultaneous determination of paracetamol, phenylephrine and chlorpheniramine in pharmaceuticals using chemometric methods and UV spectrophotometry is reported as a simple alternative technique.

MATERIAL AND METHODS

Principal components regression (PCR) and partial least squares regressions (PLS1 and PLS2) were used for chemometric analyses of data obtained from the spectra of paracetamol, phenylephrine and chlorpheniramine between wavelengths of 200 to 400 nm at several concentrations within their linear ranges. The analytical performance of these chemometric methods were characterized by relative prediction errors and recoveries (%) and compared with each other.

RESULTS

PCR, PLS1 and PLS2 were successfully applied to a tablet formulation, with no interference from excipients as indicated by the recovery. However, the PLS1 shows better results due to its flexibility and mathematical principals.

CONCLUSION

The proposed methods are simple and rapid requiring no separation step, and can be easily used as an alternative in the quality control of drugs.

MEFV mutations in Iranian Azeri Turkish patients with familial Mediterranean fever

Familial Mediterranean fever (FMF) is an autosomal recessive autoinflammatory disorder with more than 60 disease-associated mutations in the responsible gene, MEFV. In the present study, we determined 15 MEFV mutations in Iranian Azeri Turkish FMF patients. Five hundred and twenty-four unrelated patients were tested for 15 known mutations in the MEFV gene using amplification refractory mutation system-polymerase chain reaction and polymerase chain reaction-restriction fragment length polymorphism methods. Thirty-five different genotypes were characterized among the studied patients. Of the alleles investigated, the most common mutation was p.M694V (42.4%), followed by p.V726A (17%), p.E148Q (16.2%), and p.M680I (c.2040G>C) (15.2%). The p.R761H mutation (4.7%) was found to be the most frequent among the rare mutations. The mutations p.M680I (c.2040G>A), p.I692del, p.M694del and p.K695R were not found in this cohort. The remaining mutations account for 7.7% of the identifiable mutations. Five different types of complex alleles were also identified. The results show the diversity and the frequency of the mutations in the Iranian Azeri Turkish FMF patients. The p.R761H mutation is rather prevalent in Azeri Turks; therefore, it should be included in the routine molecular diagnosis of FMF patients from this ethnic group.

Aetiology and outcome of elderly burn patients in tabriz, iran

Background. Geriatric patients, usually defined as being 65 years of age or over, now make up about 10% of the major burn population. Main aim. To conduct a prospective study of elderly burn patients, analysing the predictive value of age, gender, total body surface area (TBSA) burned, inhalation trauma, pre-morbid conditions, and mortality. Methods. A 10-year prospective study of burn victims hospitalized in a major burn centre in Iran was conducted to analyse the association between age, percentage TBSA burn, inhalation injury, the causes of the burns, pre-existing co-morbid conditions and the risk of death, and the epidemiology of the burns. Results. Three hundred and eighty patients aged 65 years and over were identified. The mean patient age was 71 years. There were 109 deaths overall (28.7%), the majority of which (74) were among patients with self-inflicted burns. Except for the incidence of the burns, there were no significant differences between males and females. The mean burn size (21.6%) was significantly larger in non-survivors than in survivors (49.5% vs 10.3%; p < 0.001). In these 380 elderly burn patients, when the TBSA burned exceeded 50% mortality reached 100%. Inhalation injuries were strongly associated with large burns and were present in the majority of flame-burn fatalities. There were no deaths related to scalds. Pre-morbid conditions had no statistically significant influence on mortality. Conclusion. Large burn size was the strongest predictor of mortality among elderly burn patients, followed by the presence of inhalation injury. This study showed that burn patients aged 65 years and over can achieve a good outcome.

Finding events of electrocardiogram and arterial blood pressure signals via discrete wavelet transform with modified scales

A robust electrocardiogram (ECG) wave detection-delineation algorithm that can be applied to all ECG leads is developed in this study on the basis of discrete wavelet transform (DWT). By applying a new simple approach to a selected scale obtained from DWT, this method is capable of detecting the QRS complex, P-wave, and T-wave as well as determining parameters such as start time, end time, and wave sign (upward or downward). In the proposed method, the selected scale is processed by a sliding rectangular window of length n and the curve length in each window is multiplied by the area under the absolute value of the curve. In the next step, an adaptive thresholding criterion is conducted on the resulted signal. The presented algorithm is applied to various databases including the MIT-BIH arrhythmia database, European ST-T database, QT database, CinC Challenge 2008 database as well as high-resolution Holter data gathered in the DAY Hospital. As a result, the average values of sensitivity and positive prediction Se = 99.84 per cent and P+ = 99.80 per cent were obtained for the detection of QRS complexes with an average maximum delineation error of 13.7, 11.3, and 14.0 ms for the P-wave, QRS complex, and T-wave respectively. The presented algorithm has considerable capability in cases of a low signal-to-noise ratio, high baseline wander, and in cases where QRS complexes and T-waves appear with abnormal morphologies. Especially, the high capability of the algorithm in the detection of the critical points of the ECG signal, i.e. the beginning and end of the T-wave and the end of the QRS complex was validated by the cardiologist and the maximum values of 16.4 and 15.9 ms were recognized as absolute offset error of localization respectively. Finally, in order to illustrate an alternative capability of the algorithm, it is applied to all 18 subjects of the MIT-BIH polysomnographic database and the end-systolic and end-diastolic points of the blood pressure waveform were extracted and values of sensitivity and positive prediction Se = 99.80 per cent and P+ = 99.86 per cent were obtained for the detection of end-systolic, end-diastolic pulses.

Three output port channel-drop filter based on photonic crystals

We present a photonic-crystal (PC) channel-drop filter (CDF) design based on 3x3 PC ring resonators. The normalized transmission spectra for single-ring and dual-ring configurations have been investigated using two-dimensional finite-difference time-domain (FDTD) technique in a square-lattice dielectric-rod PC structure. First, we investigate a single ring and we show that backward and forward dropping is possible in the third communication window. Then we add another ring and waveguide to develop a new CDF. This filter consists of an input and three outputs. Our FDTD simulation yields more than 85% efficiency over each output port.

Performance comparison of neural network training algorithms in modeling of bimodal drug delivery

The major aim of this study was to model the effect of two causal factors, i.e. coating weight gain and amount of pectin-chitosan in the coating solution on the in vitro release profile of theophylline for bimodal drug delivery. Artificial neural network (ANN) as a multilayer perceptron feedforward network was incorporated for developing a predictive model of the formulations. Five different training algorithms belonging to three classes: gradient descent, quasi-Newton (Levenberg-Marquardt, LM) and genetic algorithm (GA) were used to train ANN containing a single hidden layer of four nodes. The next objective of the current study was to compare the performance of aforementioned algorithms with regard to predicting ability. The ANNs were trained with those algorithms using the available experimental data as the training set. The divergence of the RMSE between the output and target values of test set was monitored and used as a criterion to stop training. Two versions of gradient descent backpropagation algorithms, i.e. incremental backpropagation (IBP) and batch backpropagation (BBP) outperformed the others. No significant differences were found between the predictive abilities of IBP and BBP, although, the convergence speed of BBP is three- to four-fold higher than IBP. Although, both gradient descent backpropagation and LM methodologies gave comparable results for the data modeling, training of ANNs with genetic algorithm was erratic. The precision of predictive ability was measured for each training algorithm and their performances were in the order of: IBP, BBP>LM>QP (quick propagation)>GA. According to BBP-ANN implementation, an increase in coating levels and a decrease in the amount of pectin-chitosan generally retarded the drug release. Moreover, the latter causal factor namely the amount of pectin-chitosan played slightly more dominant role in determination of the dissolution profiles.

Potential application of gaseous nitric oxide as a topical antimicrobial agent

The presence of bacterial colonization in non-healing wounds and burn injuries interferes significantly with the normal process of healing. Recent evidence suggests that nitric oxide (NO) plays an important role in host defense against infection and regulates wound healing and angiogenesis. We investigated the potential application of a medical-grade gaseous form of NO (gNO) as a novel antibacterial agent in wound infection. Using a continuous horizontal-flow delivery system, the antibacterial activity of gNO was tested in vitro against a range of pathogens, including clinical isolates of Staphylococcus aureus, methicillin-resistant S. aureus, Escherichia coli, Group B Streptococcus, Pseudomonas aeruginosa, and Candida albicans. To probe the effect of topical application of gNO on the human skin, the proliferation and extracellular matrix gene expression of human dermal fibroblasts in culture were also analyzed by (3)H-thymidine incorporation assay and Northern blot techniques, respectively. Potent bacteriocidal activity was observed at 200 ppm gNO with an average of 4.1 +/- 1.1 h to completely stop bacterial growth. Interestingly, this dose of gNO did not show any cytotoxic effect in human dermal fibroblasts in culture exposed for up to 48 h. Analysis of gene transcription in fibroblasts revealed a significant increase in MMP-1 mRNA expression as early as 2 h post-exposure to gNO. Although to a lesser degree, a significant reduction in type I procollagen was also observed in the same fibroblasts. The results of this study suggest that exogenous gaseous NO has potent significant antibacterial properties that can be beneficial in reducing bacterial burden in infected wound in burn injuries or non-healing ulcers.

A direct nitric oxide gas delivery system for bacterial and mammalian cell cultures

Nitric oxide (NO) is the smallest known gaseous signaling molecule released by mammalian and plant cells. To investigate the pathophysiologic role of exogenous NO gas (gNO) in bacterial and mammalian cell cultures, a validated in vitro delivery method is required. The system should be able to deliver gNO directly to bacterial and/or cell cultures in a continuous, predictable, and reproducible manner over a long period of time (days). To accomplish this, a gas delivery system was designed to provide optimal growth conditions for bacteria and/or mammalian cells. Parameters for cell exposure, such as concentration of gNO, nitrogen dioxide (NO(2)), oxygen (O(2)), temperature, and relative humidity (RH) were continuously monitored and evaluated. Uptake of gNO into various media was monitored by measuring the nitrite concentration using the Griess reagent technique. A selection of standard growth media [saline, tryptic soy broth (TSB), Middlebrook 7H9 (MB 7H9), and Dulbecco's modified Eagle's medium (DMEM)] exposed to various concentrations of gNO revealed a steady and consistent transfer of gNO into the aqueous phase over a 48-h period. Validation of optimal growth conditions within the device, as compared to a conventional incubator, were accomplished by growing and observing viability of Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, and human fibroblast cultures in the absence of gNO. These results indicate that an optimal growth environment for the above tested cells was accomplished inside the proposed delivery system. Dose-dependent toxicological data revealed a significant bacteriostatic effect on P. aeruginosa and S. aureus with continuous exposure to 80 ppm gNO. No toxic effects were observed on dermal fibroblast proliferation at concentrations up to 400 ppm gNO for 48 h. In conclusion, the designed gNO exposure system is capable of supporting cellular viability for a representative range of prokaryote and eukaryotic cells. The exposure system is also capable of obtaining toxicological data. Therefore, the proposed device can be utilized to continuously expose cells to various levels of gNO for up to 72 h to study the in vitro effects of gNO therapy.

Prevalence of penile human papillomavirus DNA in husbands of women with and without cervical neoplasia: a study in Spain and Colombia

To investigate the role of men in cervical cancer, 816 husbands of women enrolled in four case-control studies of cervical neoplasia in populations at high (Colombia) and low (Spain) risk for cervical cancer were interviewed. Exfoliated cells from the penis were obtained and analyzed by polymerase chain reaction for the presence of human papillomavirus (HPV) DNA. Penile HPV DNA prevalences were higher in husbands of women with cervical neoplasia than in husbands of controls. Husbands of controls in Colombia had a 5-fold higher penile HPV DNA prevalence than the corresponding husbands in Spain. Strong dose-response relationships were found between penile HPV DNA prevalence and all sexual behavior-related variables in Spain but not in Colombia. Sexual promiscuity is the most important risk factor for penile HPV infections. Differences in HPV DNA prevalence in the male populations of Spain and Colombia are consistent with their 8-fold difference in cervical cancer incidences.

Continuous-wave operation of extremely low-threshold GaAs/AlGaAs broad-area injection lasers on (100) Si substrates at room temperature

Room-temperature continuous-wave operation of large-area (120 microm x 980 microm) GaAs/AlGaAs graded-refractive-index separate-confinement heterostructure lasers on (100) Si substrates has been obtained. Minimum threshold-current densities of 214 A/cm(2) (1900-microm cavity length), maximum slope efficiencies of about 0.8 W/A (600-microm cavity length), and optical power in excess of 270 mW/facet 900-microm cavity length) have been observed under pulsed conditions.