Determination of Gait Events and Temporal Gait Parameters for Persons with a Knee-Ankle-Foot Orthosis

Gait event detection is essential for controlling an orthosis and assessing the patient's gait. In this study, patients wearing an electromechanical (EM) knee-ankle-foot orthosis (KAFO) with a single IMU embedded in the thigh were subjected to gait event detection. The algorithm detected four essential gait events (initial contact (IC), toe off (TO), opposite initial contact (OIC), and opposite toe off (OTO)) and determined important temporal gait parameters such as stance/swing time, symmetry, and single/double limb support. These gait events were evaluated through gait experiments using four force plates on healthy adults and a hemiplegic patient who wore a one-way clutch KAFO and a pneumatic cylinder KAFO. Results showed that the smallest error in gait event detection was found at IC, and the largest error rate was observed at opposite toe off (OTO) with an error rate of -2.8 ± 1.5% in the patient group. Errors in OTO detection resulted in the largest error in determining the single limb support of the patient with an error of 5.0 ± 1.5%. The present study would be beneficial for the real-time continuous monitoring of gait events and temporal gait parameters for persons with an EM KAFO.

Measurements of Electrodermal Activity, Tissue Oxygen Saturation, and Visual Analog Scale for Different Cuff Pressures

The quantification of comfort in binding parts, essential human-machine interfaces (HMI) for the functioning of rehabilitation robots, is necessary to reduce physical strain on the user despite great achievements in their structure and control. This study aims to investigate the physiological impacts of binding parts by measuring electrodermal activity (EDA) and tissue oxygen saturation (StO2). In Experiment 1, EDA was measured from 13 healthy subjects under three different pressure conditions (10, 20, and 30 kPa) for 1 min using a pneumatic cuff on the right thigh. In Experiment 2, EDA and StO2 were measured from 10 healthy subjects for 5 min. To analyze the correlation between EDA parameters and the decrease in StO2, a survey using the visual analog scale (VAS) was conducted to assess the level of discomfort at each pressure. The EDA signal was decomposed into phasic and tonic components, and the EDA parameters were extracted from these two components. RM ANOVA and a post hoc paired t-test were used to determine significant differences in parameters as the pressure increased. The results showed that EDA parameters and the decrease in StO2 significantly increased with the pressure increase. Among the extracted parameters, the decrease in StO2 and the mean SCL proved to be effective indicators. Such analysis outcomes would be highly beneficial for studies focusing on the comfort assessment of the binding parts of rehabilitation robots.

TinyFallNet: A Lightweight Pre-Impact Fall Detection Model

Falls represent a significant health concern for the elderly. While studies on deep learning-based preimpact fall detection have been conducted to mitigate fall-related injuries, additional efforts are needed for embedding in microcomputer units (MCUs). In this study, ConvLSTM, the state-of-the-art model, was benchmarked, and we attempted to lightweight it by leveraging features from image-classification models VGGNet and ResNet while maintaining performance for wearable airbags. The models were developed and evaluated using data from young subjects in the KFall public dataset based on an inertial measurement unit (IMU), leading to the proposal of TinyFallNet based on ResNet. Despite exhibiting higher accuracy (97.37% < 98.00%) than the benchmarked ConvLSTM, the proposed model requires lower memory (1.58 MB > 0.70 MB). Additionally, data on the elderly from the fall data of the FARSEEING dataset and activities of daily living (ADLs) data of the KFall dataset were analyzed for algorithm validation. This study demonstrated the applicability of image-classification models to preimpact fall detection using IMU and showed that additional tuning for lightweighting is possible due to the different data types. This research is expected to contribute to the lightweighting of deep learning models based on IMU and the development of applications based on IMU data.

Quantification of Comfort for the Development of Binding Parts in a Standing Rehabilitation Robot

Human-machine interfaces (HMI) refer to the physical interaction between a user and rehabilitation robots. A persisting excessive load leads to soft tissue damage, such as pressure ulcers. Therefore, it is necessary to define a comfortable binding part for a rehabilitation robot with the subject in a standing posture. The purpose of this study was to quantify the comfort at the binding parts of the standing rehabilitation robot. In Experiment 1, cuff pressures of 10-40 kPa were applied to the thigh, shank, and knee of standing subjects, and the interface pressure and pain scale were obtained. In Experiment 2, cuff pressures of 10-20 kPa were applied to the thigh, and the tissue oxygen saturation and the skin temperature were measured. Questionnaire responses regarding comfort during compression were obtained from the subjects using the visual analog scale and the Likert scale. The greatest pain was perceived in the thigh. The musculoskeletal configuration affected the pressure distribution. The interface pressure distribution by the binding part showed higher pressure at the intermuscular septum. Tissue oxygen saturation (StO₂) increased to 111.9 ± 6.7% when a cuff pressure of 10 kPa was applied and decreased to 92.2 ± 16.9% for a cuff pressure of 20 kPa. A skin temperature variation greater than 0.2 °C occurred in the compressed leg. These findings would help evaluate and improve the comfort of rehabilitation robots.

sEMG-Based Hand Posture Recognition and Visual Feedback Training for the Forearm Amputee

sEMG-based gesture recognition is useful for human-computer interactions, especially for technology supporting rehabilitation training and the control of electric prostheses. However, high variability in the sEMG signals of untrained users degrades the performance of gesture recognition algorithms. In this study, the hand posture recognition algorithm and radar plot-based visual feedback training were developed using multichannel sEMG sensors. Ten healthy adults and one bilateral forearm amputee participated by repeating twelve hand postures ten times. The visual feedback training was performed for two days and five days in healthy adults and a forearm amputee, respectively. Artificial neural network classifiers were trained with two types of feature vectors: a single feature vector and a combination of feature vectors. The classification accuracy of the forearm amputee increased significantly after three days of hand posture training. These results indicate that the visual feedback training efficiently improved the performance of sEMG-based hand posture recognition by reducing variability in the sEMG signal. Furthermore, a bilateral forearm amputee was able to participate in the rehabilitation training by using a radar plot, and the radar plot-based visual feedback training would help the amputees to control various electric prostheses.

Fall-from-Height Detection Using Deep Learning Based on IMU Sensor Data for Accident Prevention at Construction Sites

Workers at construction sites are prone to fall-from-height (FFH) accidents. The severity of injury can be represented by the acceleration peak value. In the study, a risk prediction against FFH was made using IMU sensor data for accident prevention at construction sites. Fifteen general working movements (NF: non-fall), five low-hazard-fall movements, (LF), and five high-hazard-FFH movements (HF) were performed by twenty male subjects and a dummy. An IMU sensor was attached to the T7 position of the subject to measure the three-axis acceleration and angular velocity. The peak acceleration value, calculated from the IMU data, was 4 g or less in general work movements and 9 g or more in FFHs. Regression analysis was performed by applying various deep learning models, including 1D-CNN, 2D-CNN, LSTM, and Conv-LSTM, to the risk prediction, and then comparing them in terms of their mean absolute error (MAE) and mean squared error (MSE). The FFH risk level was estimated based on the predicted peak acceleration. The Conv-LSTM model trained by MAE showed the smallest error (MAE: 1.36 g), and the classification with the predicted peak acceleration showed the best accuracy (97.6%). This study successfully predicted the FFH risk levels and could be helpful to reduce fatal injuries at construction sites.

sEMG-Based Hand Posture Recognition Considering Electrode Shift, Feature Vectors, and Posture Groups

Surface electromyography (sEMG)-based gesture recognition systems provide the intuitive and accurate recognition of various gestures in human-computer interaction. In this study, an sEMG-based hand posture recognition algorithm was developed, considering three main problems: electrode shift, feature vectors, and posture groups. The sEMG signal was measured using an armband sensor with the electrode shift. An artificial neural network classifier was trained using 21 feature vectors for seven different posture groups. The inter-session and inter-feature Pearson correlation coefficients (PCCs) were calculated. The results indicate that the classification performance improved with the number of training sessions of the electrode shift. The number of sessions necessary for efficient training was four, and the feature vectors with a high inter-session PCC (r > 0.7) exhibited high classification accuracy. Similarities between postures in a posture group decreased the classification accuracy. Our results indicate that the classification accuracy could be improved with the addition of more electrode shift training sessions and that the PCC is useful for selecting the feature vector. Furthermore, hand posture selection was as important as feature vector selection. These findings will help in optimizing the sEMG-based pattern recognition algorithm more easily and quickly.

The Performance of Post-Fall Detection Using the Cross-Dataset: Feature Vectors, Classifiers and Processing Conditions

In this study, algorithms to detect post-falls were evaluated using the cross-dataset according to feature vectors (time-series and discrete data), classifiers (ANN and SVM), and four different processing conditions (normalization, equalization, increase in the number of training data, and additional training with external data). Three-axis acceleration and angular velocity data were obtained from 30 healthy male subjects by attaching an IMU to the middle of the left and right anterior superior iliac spines (ASIS). Internal and external tests were performed using our lab dataset and SisFall public dataset, respectively. The results showed that ANN and SVM were suitable for the time-series and discrete data, respectively. The classification performance generally decreased, and thus, specific feature vectors from the raw data were necessary when untrained motions were tested using a public dataset. Normalization made SVM and ANN more and less effective, respectively. Equalization increased the sensitivity, even though it did not improve the overall performance. The increase in the number of training data also improved the classification performance. Machine learning was vulnerable to untrained motions, and data of various movements were needed for the training.

Gapless Quantum Spin Liquid in the Triangular System Sr_{3}CuSb_{2}O_{9}

We report gapless quantum spin liquid behavior in the layered triangular Sr_{3}CuSb_{2}O_{9} system. X-ray diffraction shows superlattice reflections associated with atomic site ordering into triangular Cu planes well separated by Sb planes. Muon spin relaxation measurements show that the S=1/2 moments at the magnetically active Cu sites remain dynamic down to 65 mK in spite of a large antiferromagnetic exchange scale evidenced by a large Curie-Weiss temperature θ_{CW}≃-143  K as extracted from the bulk susceptibility. Specific heat measurements also show no sign of long-range order down to 0.35 K. The magnetic specific heat (C_{m}) below 5 K reveals a C_{m}=γT+αT^{2} behavior. The significant T^{2} contribution to the magnetic specific heat invites a phenomenology in terms of the so-called Dirac spinon excitations with a linear dispersion. From the low-T specific heat data, we estimate the dominant exchange scale to be ∼36  K using a Dirac spin liquid ansatz which is not far from the values inferred from microscopic density functional theory calculations (∼45  K) as well as high-temperature susceptibility analysis (∼70  K). The linear specific heat coefficient is about 18  mJ/mol K^{2} which is somewhat larger than for typical Fermi liquids.

Prognostic value of peri-coronary adipose tissue attenuation and whole vessel and lesion plaque quantification on Coronary Computed Tomography Angiography

Background

Peri-coronary adipose tissue attenuation expressed by fat attenuation index (FAI) on coronary CT angiography (CCTA) reflects peri-coronary inflammation and is associated with cardiac mortality. CCTA also provides two-dimensional and three-dimensional quantification of the individual component of atherosclerotic plaque and entire vessel. The atherosclerotic burden or disease extent in entire epicardial coronary arteries provides prognostic information in patients with coronary artery disease.

Purpose

This study sought to explore the prognostic significance of FAI values and whole vessel and lesion plaque quantification on CCTA in stable patients with intermediate epicardial stenosis evaluated by fractional flow reserve (FFR).

Methods

A total of 277 patients (277 lesions) with intermediate coronary stenosis who underwent FFR measurement and CCTA were studied. FAI was assessed by the crude analysis of the mean CT attenuation value (−190 to −30 Hounsfield units; higher values indicating inflammation) on CCTA. CT findings including whole vessel and lesion plaque quantification, and target vessel myocardial mass were investigated. Major adverse cardiovascular outcome (MACE) was defined as all cause death, cardiac death, myocardial infarction, unplanned revascularization, and heart failure requiring admission. Survivals from MACE were assessed.

Results

The mean FAI and the median FFR values were −71.6 and 0.77, respectively. FFR values were weakly albeit significantly correlated with FAI values. (r=−0.016, P=0.008.) MACE was occurred 43 (15.5%) patients during 5 years F-up. ROC analyses revealed that best cut-off value of FAI to predict MACE was −73.1. Kaplan-Meier analysis revealed that lesions with FAI ≥−73.1 had a significantly higher risk of MACE. (Chi-square 5.5, P=0.019) FFR values and the percutaneous coronary intervention were not predictive of MACE. Multivariate COX proportional hazards regression analysis revealed that age, remodeling index, and lesions with FAI ≥−73.1 were independent predictors of MACE.

Conclusion

The peri-coronary inflammation evaluated by FAI and CT remodeling index enhances cardiac risk prediction in chronic coronary syndrome patients with intermediate lesions. Non-invasive comprehensive CT assessment may help identify high risk patients of subsequent clinical events and provide enhanced patient management.

Funding Acknowledgement

Type of funding source: Foundation. Main funding source(s): This study was supported in part by an unrestricted research grant from St. Jude Medical (Abbot Vascular, Santa Clara, CA, USA). The company had no role in study design, conduct, data analysis or manuscript preparation.

Prognostic value of pre-revascularization fractional flow reserve mediated by the post-revascularization level: a causal mediation analysis

Background

The prognostic value of pre-percutaneous coronary intervention (PCI) fractional flow reserve (FFR) can depend on that of the post-PCI FFR and their interaction. To correctly interpret the prognostic value of pre-PCI FFR, it is essential to understand to what extent the relationship between pre-PCI FFR and clinical outcome is explained by pre-PCI FFR-related post-PCI FFR.

Purpose

The aim of this study is to investigate the extent to which post-PCI FFR mediates the relationship between pre-PCI FFR and vessel-related outcomes using a global, multicenter collaboration registry.

Methods

Patient data from 4 global FFR registries were pooled and 1488 patients with pre-PCI FFR ≤0.80 were analyzed. The primary outcome was target vessel failure (TVF) during 2-years of follow-up. We evaluated the extent to which post-PCI FFR &lt;0.90 mediated the association between pre-PCI FFR &lt;0.75 and TVF employing a causal mediation analysis in a counterfactual framework.

Results

Among 1488 patients, the mean (standard deviation) age was 63.5 (9.9) years and 78% (1161 patients) were male. The median (IQR) pre-PCI and post-PCI FFR were 0.71 (0.62–0.76) and 0.88 (0.83–0.92), respectively. The direct effect of low pre-PCI FFR (&lt;0.75) on TVF was significantly elevated (OR: 1.81, 95% CI: 1.03–3.18, p=0.038), and was not mediated by post-PCI FFR&lt;0.90 (indirect effect, OR: 1.01, 95% CI: 0.98–1.05, p=0.39). In the model, post-PCI FFR explained only 2.2% of the association between pre-PCI FFR and TVF. The subgroup analysis implicated that the prognostic information of pre-PCI FFR was mainly for diffuse lesions.

Conclusions

The prognostic information of pre-PCI FFR did not greatly depend on the results of PCI assessed by post-PCI FFR. Pre-PCI FFR, as a prognostic marker, may mainly reflect the global atherosclerotic burden of the artery, not the extent of the modifiable epicardial stenosis, thus providing independent information from post-PCI FFR.

Interpretation

Funding Acknowledgement

Type of funding source: None

Enhanced Algorithm for the Detection of Preimpact Fall for Wearable Airbags

Fall-related injury is a common cause of mortality among the elderly. Hip fractures are especially dangerous and can even be fatal. In this study, a threshold-based preimpact fall detection algorithm was developed for wearable airbags that minimize the impact of falls on the user's body. Acceleration sum vector magnitude (SVM), angular velocity SVM, and vertical angle, calculated using inertial data captured from an inertial measurement unit were used to develop the algorithm. To calculate the vertical angle accurately, a complementary filter with a proportional integral controller was used to minimize integration errors and the effect of external impacts. In total, 30 healthy young men were recruited to simulate 6 types of falls and 14 activities of daily life. The developed algorithm achieved 100% sensitivity, 97.54% specificity, 98.33% accuracy, and an average lead time (i.e., the time between the fall detection and the collision) of 280.25 ± 10.29 ms with our experimental data, whereas it achieved 96.1% sensitivity, 90.5% specificity, and 92.4% accuracy with the SisFall public dataset. This paper demonstrates that the algorithm achieved a high accuracy using our experimental data, which included some highly dynamic motions that had not been tested previously.

Evaluation of Inertial Sensor-Based Pre-Impact Fall Detection Algorithms Using Public Dataset

In this study, pre-impact fall detection algorithms were developed based on data gathered by a custom-made inertial measurement unit (IMU). Four types of simulated falls were performed by 40 healthy subjects (age: 23.4 ± 4.4 years). The IMU recorded acceleration and angular velocity during all activities. Acceleration, angular velocity, and trunk inclination thresholds were set to 0.9 g, 47.3°/s, and 24.7°, respectively, for a pre-impact fall detection algorithm using vertical angles (VA algorithm); and 0.9 g, 47.3°/s, and 0.19, respectively, for an algorithm using the triangle feature (TF algorithm). The algorithms were validated by the results of a blind test using four types of simulated falls and six types of activities of daily living (ADL). VA and TF algorithms resulted in lead times of 401 ± 46.9 ms and 427 ± 45.9 ms, respectively. Both algorithms were able to detect falls with 100% accuracy. The performance of the algorithms was evaluated using a public dataset. Both algorithms detected every fall in the SisFall dataset with 100% sensitivity). The VA algorithm had a specificity of 78.3%, and TF algorithm had a specificity of 83.9%. The algorithms had higher specificity when interpreting data from elderly subjects. This study showed that algorithms using angles could more accurately detect falls. Public datasets are needed to improve the accuracy of the algorithms.

Effects of extrusion and microbial phytase on the apparent and standardized total tract digestibility of phosphorus in hemp hulls fed to growing pigs

An experiment was carried out to determine the apparent total tract digestibility (ATTD) and the standardized total tract digestibility (STTD) of P and the effects of extrusion and microbial phytase on ATTD and STTD of P in hemp hulls (HH). Thirty-six pigs (30.3 ± 2.7 kg) were randomly allotted to 1 of 6 experimental diets in a complete randomized design with 6 replicates per diet. A corn-soybean meal (SBM)-based basal diet was formulated. Two additional diets were formulated by replacing 40% of corn and SBM (on a 100% of total diet basis) with HH or extruded HH (EHH). The test ingredients, corn, and SBM were the only sources of P in the diets. Three additional diets were also prepared by supplementing 500 unit/kg of microbial phytase to the initial 3 diets (the corn-SBM basal diet and diets containing test ingredients). Pigs were fed experimental diets at 3 times the maintenance energy requirement (197 kcal ME/kg BW0.60). Results indicated that fecal P concentration and daily P output were reduced (P < 0.05) from pigs fed diets with dietary phytase compared with pigs fed diets without dietary phytase. The ATTD and STTD of P in experimental diets were not different. However, the ATTD and STTD of P in experimental diets supplemented with dietary phytase were increased (P < 0.05) compared with the diets without phytase. The ATTD and STTD of P in HH were 18.8% and 22.0%, respectively, whereas respective values for EHH were 22.5% and 26.3%. Extrusion had no effects on ATTD and STTD of P in HH. However, the ATTD and STTD of P in HH and EHH increased (P < 0.05) when dietary phytase was added to the diets. The concentration of Ca in feces and daily Ca output were reduced (P < 0.05) as a result of phytase supplementation. Addition of dietary phytase increased (P < 0.05) the ATTD of Ca in all experimental diets. In conclusion, the ATTD and STTD of P in HH fed to growing pigs were 18.8% and 22.0%, respectively. Respective values for EHH were 22.5% and 26.3%. Extrusion did not affect the ATTD and STTD of P in HH. However, the addition of microbial phytase to experimental diets increased the ATTD and STTD of P in diets and test ingredients and decreased fecal P output from pigs fed experimental diets. There was no interaction between extrusion and dietary phytase supplementation.

Net energy content of canola meal fed to growing pigs and effect of experimental methodology on energy values

An experiment was conducted to determine the digestible energy (DE), metabolizable energy (ME), and net energy (NE) contents of canola meal (CM) and to investigate the effects of basal diet [corn diet vs. corn-soybean meal (SBM) diet] and methodology (difference method vs. regression method) on energy values of CM. Thirty-six growing barrows (20.8 ± 1.0 kg initial body weight [BW]) were individually housed in metabolism crates and randomly allotted to one of six dietary treatments to give six replicates per treatment. The six experimental diets included a corn diet, a corn-SBM diet, a corn diet with 15 or 30% of CM, and a corn-SBM diet with 15 or 30% of CM. The DE, ME, and NE of CM were determined using the corn diet or the corn-SBM diet as a basal diet. In each basal diet, two additional diets containing 15 or 30% of CM were formulated to compare the determined energy values by the difference method and estimated energy values from the regression method. Feeding level was set at 550 kcal ME/kg BW0.6 per day. Pigs were fed experimental diets for 16 d including 10 d for adaptation and 6 d for total collection of feces and urine. Pigs were then moved into indirect calorimetry chambers to determine 24 h heat production (HP) and 12 h fasting HP. The DE, ME, and NE of CM determined by the difference method were within the 95% confidence intervals estimated for the DE, ME, and NE of CM by the regression method regardless of the basal diets used, which indicates that the difference and regression methods give equivalent DE, ME, and NE of CM. However, when the goodness of fit for the linear model was compared, the r2 of the regression analysis from the corn-SBM diet (0.78) was relatively greater than that from corn diet (0.40). The estimated NE of CM by the prediction equations generated by either the corn diet or corn-SBM diets were 2,096 kcal/kg and 1,960 kcal/kg (as-fed basis), respectively, whereas those values determined by the difference method were 2,233 kcal/kg and 2,106 kcal/kg (as-fed basis), respectively. In conclusion, the NE of CM determined in the current study was, on average, 2,099 kcal/kg (as-fed basis). The difference and regression methods do not give different NE value of CM fed to growing pigs. Although the NE values of CM determined using either the corn diet or the corn-SBM diet were not different, the greater r2 of the regression analysis from the corn-SBM diet than that from the corn diet suggests that the corn-SBM diet is a more appropriate basal diet for NE determination of ingredients.

Molecular epidemiology and environmental contamination during an outbreak of parainfluenza virus 3 in a haematology ward

Background

Although fomites or contaminated surfaces have been considered as transmission routes, the role of environmental contamination by human parainfluenza virus type 3 (hPIV-3) in healthcare settings is not established.

Aim

To describe an hPIV-3 nosocomial outbreak and the results of environmental sampling to elucidate the source of nosocomial transmission and the role of environmental contamination.

Methods

During an hPIV-3 outbreak between May and June 2016, environmental surfaces in contact with clustered patients were swabbed and respiratory specimens used from infected patients and epidemiologically unlinked controls. The epidemiologic relatedness of hPIV-3 strains was investigated by sequencing of the haemagglutinin–neuraminidase and fusion protein genes.

Findings

Of 19 hPIV-3-infected patients, eight were haematopoietic stem cell recipients and one was a healthcare worker. In addition, four had upper and 12 had lower respiratory tract infections. Of the 19 patients, six (32%) were community-onset infections (symptom onset within <7 days of hospitalization) and 13 (68%) were hospital-onset infections (≥7 days of hospitalization). Phylogenetic analysis identified two major clusters: five patients, and three patients plus one healthcare worker. Therefore, seven (37%) were classified as nosocomial transmissions. hPIV-3 was detected in 21 (43%) of 49 environmental swabs up to 12 days after negative respiratory polymerase chain reaction conversion.

Conclusion

At least one-third of a peak season nosocomial hPIV-3 outbreak originated from nosocomial transmission, with multiple importations of hPIV-3 from the community, providing experimental evidence for extensive environmental hPIV-3 contamination. Direct contact with the contaminated surfaces and fomites or indirect transmission from infected healthcare workers could be responsible for nosocomial transmission.

Effects of diet complexity and multicarbohydrase supplementation on growth performance, nutrient digestibility, blood profile, intestinal morphology, and fecal score in newly weaned pigs

To study the effects of diet complexity and multicarbohydrase (MC) supplementation, 144 piglets (6.70 ± 0.81 kg of BW) weaned at 21 ± 2 d of age (1:1 male to female ratio) were assigned to 1 of 6 dietary treatments in a 3 × 2 factorial arrangement based on diet complexity (complex1, complex2, and simple) and MC addition (0 vs. 0.1% of MC). Diets were provided in a 2-phase feeding program with phase I (d 1 to 14) and phase II diets (d 15 to 28). Complex1 was formulated to mimic a conventional weaner diet with blood plasma, fish meal, dried whey, and skim milk powder, whereas complex2 partially or totally replaced these ingredients with various plant-based ingredients. The simple diet primarily comprised corn, wheat, and soybean meal. No interactions were found between diet complexity and MC supplementation ( > 0.10), except for apparent total tract digestibility (ATTD) of ash and globulin concentration on d 28 ( < 0.05). Pigs fed the complex1 diet had greater ( < 0.01) ADG, ADFI, and G:F than those fed the other diets during the first week after weaning. However, no differences in ADG or ADFI were observed for pigs fed the complex1 and simple diets throughout the 28-d experimental period ( > 0.10), whereas the complex2 diet led to lower ADG and ADFI compared with the complex1 diet ( < 0.05). Overall, G:F was greater for pigs fed the simple diet compared with those fed the complex1 diet ( < 0.01). Pigs fed the simple diet showed ATTD of DM, OM, GE, and ash comparable to those fed the complex1 diet on d 14 ( > 0.10). In contrast, greater ATTD of DM, OM, NDF, GE, and ash was observed ( < 0.05) in pigs fed the complex1 diet than in those fed the complex2 diet or the simple diet on d 28. The simple diet increased the lymphocyte proportion in serum compared with the complex1 diet ( < 0.01) on d 14. Pigs fed the complex1 diet had a greater ( < 0.05) ratio of villus height (VH) to crypt depth (CD) in the ileum compared with the other diets. The complex2 diet decreased ( < 0.05) the fecal score during 3 wk of the postweaning period compared with the complex1 diet. Dietary MC supplementation increased ( < 0.05) G:F during the overall experimental period, VH in the ileum, VH:CD ratio in the duodenum, and ATTD of DM and GE but it reduced fecal score ( < 0.05). In conclusion, feeding a simple diet resulted in BW comparable to feeding the complex1 diet, but it led to inferior intestinal morphology and ATTD of nutrients on d 28. Also, MC supplementation could be beneficial regardless of diet complexity.

Digestible, metabolizable, and net energy of camelina cake fed to growing pigs and additivity of energy in mixed diets

This experiment was conducted to determine the DE, ME, and NE contents of camelina cake (CC) and to test the hypothesis that dietary glucosinolates originating from CC will affect the additivity of energy in mixed diets containing different inclusion levels of corn, soybean meal (SBM), and CC. A total of 30 growing barrows ([Yorkshire × Landrace] × Duroc) with a mean BW of 16.8 kg (SD 1.4) were randomly allotted to 1 of 5 treatments with 6 replicates per treatment. Pigs were fed experimental diets for 16 d, including 10 d for adaptation and 6 d for total collection of feces and urine. The 5 experimental diets consisted of 3 corn-based diets to determine the DE, ME, and NE of the 3 ingredients (corn, SBM, and CC) and 2 mixed diets to test the additivity of DE, ME, and NE. The corn diet contained 97.52% corn; the SBM diet contained 67.52% corn and 30.0% SBM; the CC diet contained 67.52% corn and 30.0% CC; the Mixed diet 1 contained 67.52% corn, 20.0% SBM, and 10.0% CC; and the Mixed diet 2 contained 67.25% corn, 10.0% SBM, and 20.0% CC. Vitamins and minerals were included in the diets to meet or exceed the requirements for growing pigs (). Pigs were fed their assigned diets at 550 kcal ME/kg BW per day on the basis of BW on d 1, 5, and 10, which was close to ad libitum intake. Pigs had free access to water. Determined DE, ME, and NE contents of corn were 3,348, 3,254, and 2,579 kcal/kg, respectively; those of SBM were 3,626, 3,405, and 2,129 kcal/kg, respectively; and those of CC were 3,755, 3,465, and 2,383 kcal/kg, respectively. No differences between the predicted and determined DE, ME, and NE were observed in the 2 mixed diets. In conclusion, DE, ME, and calculated NE content of CC fed to growing pigs were 3,755, 3,465, and 2,383 kcal/kg (as-fed basis), respectively. In addition, additivity of DE, ME, and calculated NE was observed in the mixed diets containing corn, SBM, and CC, which indicates that dietary glucosinolates originating from up to 30% of CC inclusion do not affect DE, ME, and calculated NE of diets.

The Prostate Health Index adds predictive value to multi-parametric MRI in detecting significant prostate cancers in a repeat biopsy population

Both multi-parametric MRI (mpMRI) and the Prostate Health Index (PHI) have shown promise in predicting a positive biopsy in men with suspected prostate cancer. Here we investigated the value of combining both tests in men requiring a repeat biopsy. PHI scores were measured in men undergoing re-biopsy with an mpMRI image-guided transperineal approach (n = 279, 94 with negative mpMRIs). The PHI was assessed for ability to add value to mpMRI in predicting all or only significant cancers (Gleason ≥7). In this study adding PHI to mpMRI improved overall and significant cancer prediction (AUC 0.71 and 0.75) compared to mpMRI + PSA alone (AUC 0.64 and 0.69 respectively). At a threshold of ≥35, PHI + mpMRI demonstrated a NPV of 0.97 for excluding significant tumours. In mpMRI negative men, the PHI again improved prediction of significant cancers; AUC 0.76 vs 0.63 (mpMRI + PSA). Using a PHI≥35, only 1/21 significant cancers was missed and 31/73 (42%) men potentially spared a re-biopsy (NPV of 0.97, sensitivity 0.95). Decision curve analysis demonstrated clinically relevant utility of the PHI across threshold probabilities of 5-30%. In summary, the PHI adds predictive performance to image-guided detection of clinically significant cancers and has particular value in determining re-biopsy need in men with a negative mpMRI.

A Novel Combined Hybrid Approach to Enable Revascularisation of a Trauma-Induced Subclavian Artery Injury

Introduction

This case highlights the complexity of upper limb revascularization after a subclavian artery traumatic injury and strengthens the role of a hybrid/multi-disciplinary approach to such injuries.

Report

A 45-year-old male patient presented with an acute right upper limb following a traumatic injury to the right subclavian artery due to a motor vehicle accident (MVA). Associated injuries included an unstable cervical spine injury, a large open right clavicular injury, and a brain injury, which limited the potential revascularisation options available. The arm was revascularised using a hybrid endovascular/open surgical approach, namely embolization of the proximal subclavian artery (just distal to vertebral artery) and a right common femoral artery to distal axillary artery bypass using prosthetic material.

Discussion

Blunt injuries to the subclavian artery are often high impact, complex and associated with multiple injuries to surrounding structures, which limit the role of standard procedures used in the elective setting. This case highlights the role of multidisciplinary team involvement, using a hybrid approach and a novel distal inflow site to restore upper limb perfusion.

•

Major vascular trauma often requires a multidisciplinary team approach.

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Prompt decision is required even if it involves unusual methods of treatment.

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A combined hybrid endovascular/open surgical treatment should be considered.

336 QUANTITATIVE ANALYSIS OF TETRACYCLINE-INDUCIBLE EXPRESSION OF THE GREEN FLUORESCENT PROTEIN GENE IN TRANSGENIC CHICKENS

The use of transgenic farm animals as bioreactors to address the growing demand for biopharmaceuticals, both in terms of increased quantity and greater number, represents a key development in the advancement of medical science. However, the potential for detrimental side effects as a result of uncontrolled constitutive expression of foreign genes in transgenic animals is a well-recognised limitation of such systems. Previously, using a tetracycline-inducible expression system, we demonstrated the induction of expression of a transgene encoding green fluorescent protein (GFP) in transgenic chickens by feeding with doxycycline, a tetracycline derivative; expression of GFP reverted to pre-induction levels when the inducer was removed from the diet (Kwon et al. 2011 Biochem. Biophys. Res. Commun. 410, 890–894). As a proof of principle study, however, quantitative assessment of expression was not possible, as only 1 G0 and 1 G1 transgenic chicken was obtained. In the current study, with 7 G2 transgenic chickens obtained from 1 G1 hen, we confirmed stable genomic integration of a single copy number of the transgene by Southern blot analysis. As we have observed in G1 transgenic chicken previously, all of the G2 transgenic chickens emitted a green fluorescence upon doxycycline feeding (50 mg kg–1 of formula feed). Fluorescence became detectable 4 days after starting doxycycline feeding, and maximum GFP expression was detected after 2 weeks. Removal of doxycycline from the diet after 14 days of induction feeding resulted in the return of external fluorescence to pre-induction levels after 39 days. Quantitative analysis of gene induction was done using protein and mRNA extracted from primary cultured cells derived from 6-day transgenic chicken embryos. The eggs were obtained by mating a nontransgenic wild-type hen with 1 of G2 transgenic roosters. Protein levels of GFP were analysed by immunoblot and quantified using a densitometer. In the absence of doxycycline, the amount of GFP per 1 µg of total protein was 0.2 ng. However, when the cells were treated with doxycycline for 6 days, the amount of GFP increased to 3.1 ng per 1 µg of total protein, which was 16-fold higher than that of the cells pre-treated with doxycycline. Switching to doxycycline-free medium after doxycycline induction resulted in significant abrogation of GFP expression in 6 days; the amount of GFP reduced from 3.1 to 0.5 ng, a 6.2-fold reduction. Transcription of the GFP gene was also assessed by Northern blot. The amount of GFP mRNA measured by band density increased as much as 20-fold (3.9/0.2) with 6 days of doxycycline induction and declined to 1/8 (3.9/0.5) when doxycycline was removed from the cell culture media for 6 days. The use of an inducible expression system that can be regulated by dietary supplementation could help mitigate the physiological disruption that can occur in transgenic animals as a result of uncontrolled constitutive expression of a transgene.

Infiltration of intratumoral T cells and regulatory T cells are associated with p53 expression and ER status in early breast cancer: a Korean breast cancer study

Abstract #5049

Background: Immune responses, such as rich lymphocyte infiltrate, have shown associated with improved clinical outcomes in patients with breast cancer. Recently, number of tumor-infiltrating regulatory T cell has been identified as a poor prognostic marker. There is, however, not enough data evaluating the associations between the clinicopathologic factors and quantity or quality of TILs in Asian breast cancer patients.&#x2028; Material and methods: CD4-, CD8-, and Foxp3-positive tumor-infiltrating lymphocytes (TILs) were detected by immunohistochemistry using the paraffin-embedded samples from the 40 patients with early stage (I-III) breast cancer. Expression status of ER, PR, HER-2, p53, and Ki-67 were also evaluated by immunohistochemistry. Clinical data, such as pathologic stage, patient's age, were available for statistical analysis.&#x2028; Results: Statistically significant correlation between ER expression and CD8/CD4 ratio of the TILs (Spearman r=0.447, p=0.024) was observed. Other clinicopathlogical factors, such as PR, tumor size, nodal metastasis, tumor grade, did not show significant correlation with ratio of the TILs. Additionally, tumors with more dense accumulation of p53 protein were associated with recruitment of higher number of Foxp3-positive regulatory T cells (Spearman r=0.52, p=0.0002). Ki-67, a proliferation index of the tumor cells, was also statistically significantly associated with infiltration of regulatory T cells (Spearman r=0.46, p=0.019).&#x2028; Discussion: Our data showed that ER-positive tumors had higher ratio of CD8/CD4 TILs, which is opposite result from the previous studies. In addition, p53 overexpression and high proliferation index of the breast cancer were associated with high regulatory T cell infiltration, but not with total TIL. The role of the p53 overexpression of the tumor cells in determining immune balance and its prognostic implication will be evaluated in the future study.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 5049.

304 PRODUCTION OF TRANSGENIC CHICKENS EXPRESSING HUMAN ERYTHROPOIETIN IN A TETRACYCLINE-INDUCIBLE MANNER

The use of livestock animals as bioreactors to address the growing demand for large quantities and increasing numbers of biopharmaceuticals is of prime strategic relevance to agricultural improvement and medical advancement. We report here the production of transgenic chickens that produce human erythropoietin (hEPO) using replication-defective Moloney murine leukemia virus-based vectors. Because it is well known that constitutive overexpression of some cytokine genes in the transgenic animals may cause serious physiological disturbances, the vectors were designed to express in the presence of tetracycline. In addition, we introduced woodchuck hepatitis virus posttranscriptional regulatory element sequence at 3′ end of hEPO gene to boost the gene expression under the inducible condition. Approximately 5 μL of vector virus solution concentrated as much as 109 cfu mL–1 was injected beneath the blastoderm of non-incubated chicken embryo (stage X). Out of 596 injected eggs, 36 chicks hatched after 21 days of incubation and 23 hatched chicks were found to express vector-encoded hG-GSF gene when fed with doxycycline. Quantitative analysis of the blood samples taken from some Go transgenic chickens resulted in more than 300 IU mL–1 of hEPO in the blood. These transgenic chickens have not exhibited any physiological abnormalities; therefore, it is possible that this controllable gene expression system may be useful in minimizing detrimental side effects when used to produce other transgenic animals. The biological activity of the recombinant hEPO was comparable to its commercially derived Escherichia coli counterpart. The significance of this work stems from the fact that it is the first successful report on the production of transgenic chickens expressing the hEPO gene. This approach can be employed to create a useful transgenic model system for further studies on the chicken embryo development and the efficient production of transgenic chickens as bioreactors. This work was supported by: The BioGreen 21 Program of the Rural Development Administration, Republic of Korea; The SRC/ERC program of MOST/KOSEF (grant no. R11-2002-100-04005-0); The 2006–2011 Technology Development Program for Agriculture and Forestry (TDPAF), Ministry of Agriculture and Forestry, Republic of Korea.