Signal intensity and volume of carotid intraplaque hemorrhage on magnetic resonance imaging and the risk of ipsilateral cerebrovascular events: The Plaque At RISK (PARISK) study.

BACKGROUND: The Plaque At RISK (PARISK) study demonstrated that patients with a carotid plaque with intraplaque hemorrhage (IPH) have an increased risk of recurrent ipsilateral ischemic cerebrovascular events. It was previously reported that symptomatic carotid plaques with IPH showed higher IPH signal intensity ratios (SIR) and larger IPH volumes than asymptomatic plaques. We explored whether IPH SIR and IPH volume are associated with future ipsilateral ischemic cerebrovascular events beyond the presence of IPH. METHODS: Transient ischemic attack and ischemic stroke patients with mild-to-moderate carotid stenosis and an ipsilateral IPH-positive carotid plaque (n = 89) from the PARISK study were included. The clinical endpoint was a new ipsilateral ischemic cerebrovascular event during 5 years of follow-up, while the imaging-based endpoint was a new ipsilateral brain infarct on brain magnetic resonance imaging (MRI) after 2 years (n = 69). Trained observers delineated IPH, a hyperintense region compared to surrounding muscle tissue on hyper T1-weighted magnetic resonance images. The IPH SIR was the maximal signal intensity in the IPH region divided by the mean signal intensity of adjacent muscle tissue. The associations between IPH SIR or volume and the clinical and imaging-based endpoint were investigated using Cox proportional hazard models and logistic regression, respectively. RESULTS: During 5.1 (interquartile range: 3.1-5.6) years of follow-up, 21 ipsilateral cerebrovascular ischemic events were identified. Twelve new ipsilateral brain infarcts were identified on the 2-year neuro MRI. There was no association for IPH SIR or IPH volume with the clinical endpoint (hazard ratio (HR): 0.89 [95% confidence interval: 0.67-1.10] and HR: 0.91 [0.69-1.19] per 100-µL increase, respectively) nor with the imaging-based endpoint (odds ratio (OR): 1.04 [0.75-1.45] and OR: 1.21 [0.87-1.68] per 100-µL increase, respectively). CONCLUSION: IPH SIR and IPH volume were not associated with future ipsilateral ischemic cerebrovascular events. Therefore, quantitative assessment of IPH of SIR and volume does not seem to provide additional value beyond the presence of IPH for stroke risk assessment. TRIAL REGISTRATION: The PARISK study was registered on ClinicalTrials.gov with ID NCT01208025 on September 21, 2010 (https://clinicaltrials.gov/study/NCT01208025).

Various Factors that are Causing Difference in Prevalence of Coronary Risk Factors among Siblings.

BACKGROUND AND AIM: Coronary artery disease (CAD) is one of the predominant types of cardiovascular disease (CVD). The aim of present study was to study various factors that are causing difference in prevalence of coronary risk factors among siblings. MATERIALS AND METHODS: This cross-sectional study was conducted in Dayanand Medical College and Hospital, among the healthy individuals (not known CAD) attending regular health care outpatient department (OPD) and their siblings over a period of 1½ years. All individuals coming for regular health checkup (not known CAD) of age more than 30 years or above and their siblings (with or without known CAD). RESULTS: This was a cross-sectional study, conducted among 100 pairs of healthy siblings (not known cases of CAD) who came for health checkup at health center of Dayanand Medical College and Hospital, a tertiary care hospital in North India. Prevalence of obesity was more in siblings living in urban area than their counter siblings living in rural area, but it was statistically insignificant. Six had impaired fasting blood sugar (FBS) and two were diabetic. Among their siblings living in urban area, 21 were nondiabetic, 10 had impaired FBS, and seven were diabetic. This correlation was statistically significant with p-value of 0.02. Among the CAD negative, out of 23 subjects, two subjects (9.0%) had heavy stress level, while remaining four subjects (17.0%) and 17 subjects (74.0%) had light and moderate stress levels, respectively. Among the CAD negative, out of 23 subjects, 10 subjects (43.0%) had high stress level, while remaining zero subject (0%) and 13 subjects (57.0%) had light and moderate stress levels, respectively. Significant results were obtained while comparing the CAD findings of subjects divided on the basis of stress level. CONCLUSION: In our study, among siblings (CAD positive and CAD negative), significant results were obtained for residence, socioeconomic class, physical activity, stress levels, smoking, waist-to-hip ratio (WHR), and diabetes, that is, all these factors have correlation in increasing CAD among siblings.

Symptomatic Carotid Plaques Demonstrate Less Leaky Plaque Microvasculature Compared With the Contralateral Side: A Dynamic Contrast-Enhanced Magnetic Resonance Imaging Study.

Background Rupture of a vulnerable carotid atherosclerotic plaque is an important underlying cause of ischemic stroke. Increased leaky plaque microvasculature may contribute to plaque vulnerability. These immature microvessels may facilitate entrance of inflammatory cells into the plaque. The objective of the present study is to investigate whether there is a difference in plaque microvasculature (the volume transfer coefficient Ktrans) between the ipsilateral symptomatic and contralateral asymptomatic carotid plaque using noninvasive dynamic contrast-enhanced magnetic resonance imaging. Methods and Results Eighty-eight patients with recent transient ischemic attack or ischemic stroke and ipsilateral >2 mm carotid plaque underwent 3 T magnetic resonance imaging to identify plaque components and to determine characteristics of plaque microvasculature. The volume transfer coefficient Ktrans, indicative for microvascular density, flow, and permeability, was calculated for the ipsilateral and asymptomatic plaque, using a pharmacokinetic model (Patlak). Presence of a lipid-rich necrotic core, intraplaque hemorrhage, and a thin and/or ruptured fibrous cap was assessed on multisequence magnetic resonance imaging . We found significantly lower Ktrans in the symptomatic carotid plaque compared with the asymptomatic side (0.057±0.002 min-1 versus 0.062±0.002 min-1; P=0.033). There was an increased number of slices with intraplaque hemorrhage (0.9±1.6 versus 0.3±0.8, P=0.002) and lipid-rich necrotic core (1.4±1.9 versus 0.8±1.4, P=0.016) and a higher prevalence of plaques with a thin and/or ruptured fibrous cap (32% versus 17%, P=0.023) at the symptomatic side. Conclusions Ktrans was significantly lower in symptomatic carotid plaques, indicative for a decrease of plaque microvasculature in symptomatic plaques. This could be related to a larger amount of necrotic tissue in symptomatic plaques. Clinical Trial Registration URL : http://www.clinicaltrials.gov.uk . Unique identifier: NCT 01208025.

Ischemic Stroke Patients Demonstrate Increased Carotid Plaque Microvasculature Compared to (Ocular) Transient Ischemic Attack Patients.

BACKGROUND: Patients with a recent ischemic stroke have a higher risk of recurrent stroke compared to (ocular) transient ischemic attack (TIA) patients. Plaque microvasculature is considered as a feature of plaque vulnerability and can be quantified with carotid dynamic contrast-enhanced MRI (DCE-MRI). The purpose of this cross-sectional study was to explore the association between plaque microvasculature and the type of recent cerebrovascular events in symptomatic patients with mild-to-moderate carotid stenosis. METHODS: A total of 87 symptomatic patients with a recent stroke (n = 35) or (ocular) TIA (n = 52) underwent carotid DCE-MRI examination. Plaque microvasculature was studied in the vessel wall and adventitia using DCE-MRI and the pharmacokinetic modeling parameter Ktrans. Statistical analysis was performed with logistic regression, correcting for associated clinical risk factors. RESULTS: The 75th percentile adventitial (OR 1.97, 95% CI 1.18-3.29) Ktrans was significantly associated with a recent ischemic stroke compared to (ocular) TIA in multivariate analysis, while clinical risk factors were not significantly associated with the type of event. CONCLUSIONS: This study indicates a positive association of leaky plaque microvasculature with a recent ischemic stroke compared to (ocular) TIA. Prospective longitudinal studies are needed to investigate whether Ktrans or other plaque characteristics may serve as an imaging marker for predicting (the type of) future cerebrovascular events.

Postprandial hypotension in clinical geriatric patients and healthy elderly: prevalence related to patient selection and diagnostic criteria.

The aims of this study were to find out whether Postprandial hypotension (PPH) occurs more frequently in patients admitted to a geriatric ward than in healthy elderly individuals, what the optimal interval between blood pressure measurements is in order to diagnose PPH and how often it is associated with symptoms.The result of this study indicates that PPH is present in a high number of frail elderly, but also in a few healthy older persons. Measuring blood pressure at least every 10 minutes for 60 minutes after breakfast will adequately diagnose PPH, defined as >20 mmHg systolic fall, in most patients. However with definition of PPH as >30 mmHg systolic fall, measuring blood pressure every 10 minutes will miss PPH in one of three patients. With the latter definition of PPH the presence of postprandial complaints is not associated with the existence of PPH.

Facial expression (mood) recognition from facial images using committee neural networks.

BACKGROUND: Facial expressions are important in facilitating human communication and interactions. Also, they are used as an important tool in behavioural studies and in medical rehabilitation. Facial image based mood detection techniques may provide a fast and practical approach for non-invasive mood detection. The purpose of the present study was to develop an intelligent system for facial image based expression classification using committee neural networks. METHODS: Several facial parameters were extracted from a facial image and were used to train several generalized and specialized neural networks. Based on initial testing, the best performing generalized and specialized neural networks were recruited into decision making committees which formed an integrated committee neural network system. The integrated committee neural network system was then evaluated using data obtained from subjects not used in training or in initial testing. RESULTS AND CONCLUSION: The system correctly identified the correct facial expression in 255 of the 282 images (90.43% of the cases), from 62 subjects not used in training or in initial testing. Committee neural networks offer a potential tool for image based mood detection.

Toward a fuzzy logic control of the infant incubator.

Premature birth is a world wide problem. Thermo regulation is a major problem in premature infants. Premature infants are often kept in infant incubators providing convective heating. Currently either the incubator air temperature is sensed and used to control the heat flow, or infant's skin temperature is sensed and used in the close loop control. Skin control often leads to large fluctuations in the incubator air temperature. Air control also leads to skin temperature fluctuations. The question remains if both the infant's skin temperature and the incubator air temperature can be simultaneously used in the control. The purpose of the present study was to address this question by developing a fuzzy logic control which incorporates both incubator air temperature and infant's skin temperature to control the heating. The control was evaluated using a lumped parameter mathematical model of infant-incubator system (Simon, B. N., N. P. Reddy, and A. Kantak, J. Biomech. Eng. 116:263-266, 1994). Simulation results confirmed previous experimental results that the on-off skin control could lead to fluctuations in the incubator air temperature, and the air control could lead to too slow rise time in the core temperature. The fuzzy logic provides a smooth control with the desired rise time.

Neural network committees for finger joint angle estimation from surface EMG signals.

BACKGROUND: In virtual reality (VR) systems, the user's finger and hand positions are sensed and used to control the virtual environments. Direct biocontrol of VR environments using surface electromyography (SEMG) signals may be more synergistic and unconstraining to the user. The purpose of the present investigation was to develop a technique to predict the finger joint angle from the surface EMG measurements of the extensor muscle using neural network models. METHODOLOGY: SEMG together with the actual joint angle measurements were obtained while the subject was performing flexion-extension rotation of the index finger at three speeds. Several neural networks were trained to predict the joint angle from the parameters extracted from the SEMG signals. The best networks were selected to form six committees. The neural network committees were evaluated using data from new subjects. RESULTS: There was hysteresis in the measured SMEG signals during the flexion-extension cycle. However, neural network committees were able to predict the joint angle with reasonable accuracy. RMS errors ranged from 0.085 +/- 0.036 for fast speed finger-extension to 0.147 +/- 0.026 for slow speed finger extension, and from 0.098 +/- 0.023 for the fast speed finger flexion to 0.163 +/- 0.054 for slow speed finger flexion. CONCLUSION: Although hysteresis was observed in the measured SEMG signals, the committees of neural networks were able to predict the finger joint angle from SEMG signals.

Gene expression based leukemia sub-classification using committee neural networks.

Analysis of gene expression data provides an objective and efficient technique for sub-classification of leukemia. The purpose of the present study was to design a committee neural networks based classification systems to subcategorize leukemia gene expression data. In the study, a binary classification system was considered to differentiate acute lymphoblastic leukemia from acute myeloid leukemia. A ternary classification system which classifies leukemia expression data into three subclasses including B-cell acute lymphoblastic leukemia, T-cell acute lymphoblastic leukemia and acute myeloid leukemia was also developed. In each classification system gene expression profiles of leukemia patients were first subjected to a sequence of simple preprocessing steps. This resulted in filtering out approximately 95 percent of the non-informative genes. The remaining 5 percent of the informative genes were used to train a set of artificial neural networks with different parameters and architectures. The networks that gave the best results during initial testing were recruited into a committee. The committee decision was by majority voting. The committee neural network system was later evaluated using data not used in training. The binary classification system classified microarray gene expression profiles into two categories with 100 percent accuracy and the ternary system correctly predicted the three subclasses of leukemia in over 97 percent of the cases.

The effect of intraduodenal glucose on muscle sympathetic nerve activity in healthy young and older subjects.

OBJECTIVE: The cardiovascular response to a meal is modulated by gastric distension and the interaction of nutrients, particularly carbohydrate, within the small intestine. We tested the hypothesis that the depressor effect of small intestinal glucose is greater in older than in young subjects, because the reflex increase in muscle sympathetic nerve activity (MSNA) is blunted by age. METHODS: The effects of intraduodenal glucose infusion (IDGI) on blood pressure, heart rate and MSNA were evaluated in eight healthy young subjects (4 women; mean age +/- SEM: 28.8 +/- 3.4 years), eight healthy elderly (4 women; 75.3 +/- 1.6 years) and in two patients with symptomatic postprandial hypotension (PPH), one young (21 years), and one old (90 years). RESULTS: In both young and elderly healthy subjects, IDGI decreased blood pressure (P < 0.05), but the fall in systolic blood pressure was greater in the older subjects (-17.0 +/- 4.1 vs. -6.5 +/- 1.6 mmHg, P < 0.03). MSNA increased similarly, after infusion in both young (9.0 +/- 3.4 bursts/min) and elderly (7.8 +/- 1.0 bursts/min) subjects. Baroreflex sensitivity for number of sympathetic bursts was attenuated in the elderly (P < 0.03). The increase in burst area in the young patient with PPH was attenuated (18 vs. 63% in the healthy young group). INTERPRETATION: The fall in BP induced by IDGI was greater in healthy elderly compared to healthy young subjects. The reason for this is unclear, as they have similar increases in MSNA.

Toward direct biocontrol using surface EMG signals: control of finger and wrist joint models.

Increased interest in virtual reality (VR) and telemanipulation has created a growing need for the development of new interfacing devices for measuring controlling actions of the human hand. The objective of the present study was to determine if surface electromyography signals (SEMG) from the flexor digitorum superficialis (FDS), and flexor carpi ulnaris (FCU) generated during flexion-extension of the human index finger and wrist can be used for controlling the flexion-extension of the finger and wrist of a simple geometric computer model. A simple geometric computer model of finger and wrist joints was developed. Eighteen subjects controlled the computer model using the SEMG signals from their FDS and FCU. The results indicate that the SEMG signals from the FDS and FCU muscles can be used as a direct biocontrol technique for controlling the finger and wrist models. This study establishes the proof of concept for direct biological control of the dynamic motion of the finger and wrist models for use in virtual reality environments and telemanipulation.

Synthesis of multisubstituted quinolines from Baylis-Hillman adducts obtained from substituted 2-chloronicotinaldehydes and their antimicrobial activity.

Baylis-Hillman acetates were synthesized from substituted 2-chloronicotinaldehydes and were conveniently transformed into multisubstituted quinolines and cyclopenta[g]quinolines on reaction with nitroethane or ethyl cyanoacetate via a successive S(N)2'-S(N)Ar elimination strategy. Thus, synthesized quinolines were evaluated for antimicrobial activity and found having substantial antibacterial and antifungal activity.

Subtle involvement of the parasympathetic nervous system in patients with irritable bowel syndrome.

This study comprises assessment of autonomic function in irritable bowel syndrome (IBS) patients, focusing on meal-related changes. In 18 IBS patients (4 males, mean age 45+/-3.0 [SEM] years) and 19 healthy volunteers (6 males, mean age 41+/-3.5 years) blood pressure, heart rate, heart rate variability and muscle sympathetic nerve activity (MSNA) were assessed before, during and after consumption of a standardized meal. In pre- and postprandial phase Valsalva maneuver, cold pressor test (CPT) and deep breathing test were carried out and Visual Analog Scale (VAS) scores for nausea, bloating and pain were obtained. In the IBS group, the meal induced significantly higher VAS scores for pain (P=0.002) and bloating (P=0.02). During food intake, the increase in blood pressure, heart rate and MSNA was equal in patients and controls, but the increase of LF/HF ratio of heart rate variability was significantly higher in the IBS group (median [quartiles] 2.29 [1.14-3.00] versus 0.77 [0.25-1.81]; P=0.03). IBS patients scored lower on pre- and postprandial RRmax/RRmin ratio during deep breathing (DB ratio, P=0.03). The increase in MSNA (burst frequency) in response to CPT tended to be higher in the IBS patients (P=0.07). We conclude that reactivity to food intake, measured as muscle sympathetic nerve activity, is normal in IBS patients. The lower DB ratio and higher LF/HF ratio during food intake in IBS patients is an indication of a reduced parasympathetic reactivity. These results suggest that reduced baseline activity as well as responsiveness of the parasympathetic system could play a role in the pathogenesis of IBS.

Anti-malarial activity of Baylis-Hillman adducts from substituted 2-chloronicotinaldehydes.

New Baylis-Hillman adducts are synthesized based on substituted 2-chloronicotinaldehydes and screened for their in vitro anti-malarial activity against chloroquine sensitive and chloroquine resistant Plasmodium falciparum. Out of the six new compounds synthesized and screened, 2b, 2c and 2d compounds showed substantial anti-malarial activity.

Fractal analysis of acceleration signals from patients with CPPD, rheumatoid arthritis, and spondyloarthroparthy of the finger joint.

Arthritis is one of the leading causes of disability and affects a major segment of the population. Consequently, accurate diagnosis of arthritis is important. Arthritis due to calcium pyrophosphate deposition disease (CPPD), rheumatoid arthritis, and spondyloarthropathy, induce complex changes in the cartilage and the articular surface. The fractal dimension provides a measure of the complexity of a signal. Recently, we have developed non-invasive acceleration measurements to characterize the arthritic patients. The question remains if the fractal dimension of the acceleration signal is different for different arthritis conditions. The purpose of this study was to distinguish between different types of arthritis of the finger joint using the fractal dimension of the acceleration signal obtained from the finger joint of the arthritic patients. Acceleration signals were obtained from the finger joint of arthritis patients with rheumatoid arthritis, spondyloarthropathy, and calcium pyrophosphate deposition disease of the finger joint. ANOVA results showed that there were significant differences between the fractal dimension of acceleration signals from patients having calcium pyrophosphate deposition disease and rheumatoid arthritis and spondyloarthropathy. Fractal dimension of acceleration signals, in concert with other clinical symptoms, can be used to classify different types of arthritis.

Speaker verification using committee neural networks.

Security is a major problem in web based access or remote access to data bases. In the present study, the technique of committee neural networks was developed for speech based speaker verification. Speech data from the designated speaker and several imposters were obtained. Several parameters were extracted in the time and frequency domains, and fed to neural networks. Several neural networks were trained and the five best performing networks were recruited into the committee. The committee decision was based on majority voting of the member networks. The committee opinion was evaluated with further testing data. The committee correctly identified the designated speaker in (50 out of 50) 100% of the cases and rejected imposters in (150 out of 150) 100% of the cases. The committee decision was not unanimous in majority of the cases tested.