Preoperative mitral annulus size - Can we get it right?

Objective: We looked for a correlation between the surgically measured mitral valve size and the cardiac dimensions (left ventricle internal diameter, left atrial size, aorta size, and body surface area) measured by preoperative and intraoperative echocardiography. We also assessed to see if we could predict the mitral prosthesis size based on the correlation data obtained. Methods: The hospital records of 180 patients who underwent mitral valve replacement (MVR) with TTK Chitra valve between January 2008 and December 2012 at our hospital, were studied. The correlation between surgically measured mitral annulus size to left ventricular internal diameter systolic (LVIDS) and diastolic (LVIDD), left atrial size (linear measurement), and aorta size on echocardiography and body surface area was calculated using Pearson correlation coefficient. Mean LVIDS was calculated for each valve prosthesis size separately and the correlation was studied. Results: The correlation between mitral valve prosthesis size and left ventricular internal diameter (systolic) showed a Pearson coefficient of 3.3 with significance at the level 0.01. Mitral valve size and left atrial size showed a correlation coefficient of 2.7 with significance at the level 0.01. The correlation coefficient for mitral valve size with left ventricular internal diameter diastolic, aorta and body surface area were 2.5, 1.9, and 1.8, respectively. There was a gradual increase in the mean LVIDS with increase in the prosthetic valve size. Box plot and scatter plot showed linear correlation between valve size and mean LVIDS.

Internal Jugular Vein Cannulation Using a 3-Dimensional Ultrasound Probe in Patients Undergoing Cardiac Surgery: Comparison Between Biplane View and Short-Axis View.

OBJECTIVE: To compare the clinical performance in terms of procedure time, success rate, and cannulation attempts between ultrasound biplane view (BPX) and short-axis (SAX) view for internal jugular vein cannulation (IJV) in patients undergoing cardiac surgery. DESIGN: Prospective, observational pilot study. SETTING: University level tertiary referral hospital. PATIENTS: The study comprised 100 patients between ages 18 and 75 years undergoing elective cardiac surgery. INTERVENTIONS: One hundred patients were divided into 2 groups of 50 (BPX group and SAX group) by assigning the study participants alternatively to each group. IJV cannulation was performed using a 3-dimensional ultrasound probe in all patients with either BPX view (BPX group, n = 50) or the SAX view (SAX group, n = 50) by an experienced anesthesiologist. MEASUREMENTS AND MAIN RESULTS: Time required for imaging, time for IJV puncture, time for guidewire confirmation, number of needle punctures and needle redirections, and incidence of posterior wall puncture were noted in both groups. In addition, the quality of needle visualization and the incidence of complications were recorded. The time taken for imaging was significantly greater in the BPX group than in the SAX group (9.52 ± 2.69 s v 7.94 ± 2.55 s; p = 0.0034), whereas the time taken for IJV puncture (10.39 ± 2.33 s v 23.7 ± 2.46 s; p < 0.0001), time taken for confirmation of guidewire (32.94 ± 4.50 s v 57.64 ± 7.14 s; p < 0.0001), and the incidence of posterior wall puncture (4% v 26%; p = 0.0022) were significantly less in the BPX group than in the SAX group. The total number of attempts taken to puncture the IJV was fewer in the BPX group than in the SAX group (55 v 78). Successful puncture of the IJV occurred on the first attempt in 90% of patients in the BPX group, whereas it was only 50% in the SAX group (p < 0.0001). The quality of needle visualization was good in 90% of patients in the BPX group, whereas it was only 6% in the SAX group. The number of needle redirections for IJV puncture was less in the BPX group than in the SAX group (48 v 116). The incidence of complications was not significant between the 2 groups. CONCLUSION: The results suggested that the BPX view may be a safer, feasible and more reliable method than the SAX view for IJV cannulation in cardiac surgical patients.

In vivo carotid strain imaging using principal strains in longitudinal view.

Carotid plaque rupture can result in stroke or transient ischemic attack that can be devastating for patients. Ultrasound strain imaging provides a noninvasive method to identify unstable plaque likely to rupture. Axial, lateral and shear strains in carotid plaque have been shown to be linked to carotid plaque instability. Recently, there has been interest in using principal strains, which do not depend on angle of insonification of the carotid artery for quantifying instability in plaque along the longitudinal view. In this work relationships between angle dependent axial, lateral and shear strain along with axis independent principal strains are compared. Three strain indices were defined, 1) Average Mean Strain (AMS), 2) Maximum Mean Strain (MMS) and 3) Mean Standard Deviation (MSD) to identify relationships between these five strain image types in a group of 76 in vivo patients. The maximum principal strain demonstrated the highest strain values when compared to axial strain for all patients with a linear regression slope of 1.6 and a y intercept of 2.4 percent strain for AMS. The maximum shear strain when compared to shear strain had a slope of 1.15 and a y intercept of 0.21 percent for AMS. Next, the effect of insonification angle, which is the angle subtended by the artery at the location of plaque was studied. Patients were divided into three sub groups, i.e. less than 5 degrees (n = 31), between 5 and 10 degrees (n = 24) and above 10 degrees (n = 21). The angle of insonification did not make a significant difference between the three angle groups when comparing the relationship between the angle dependent and independent strain values.

Outcomes of Mitral Valve Replacement after Closed Mitral Valvotomy: A Retrospective Cohort Study.

BACKGROUND: The incidence of rheumatic fever and rheumatic heart disease still remains high in the developing countries. Mitral stenosis is predominantly due to rheumatic origin and affects females more than males. Historically, closed mitral valvotomy (CMV) was the first effective intervention for mitral stenosis. We studied the immediate and early surgical outcomes of MVR in patients with history of CMV to see whether their disease behaves differently, when compared with patients without prior CMV undergoing MVR. METHODS: This single center retrospective cohort study was conducted in Sree Chitra Tirunal Institute for Medical Sciences and Technology, Thiruvananthapuram, Kerala, India. Patients who underwent MVR from January 2008 to December 2012 at our institute were studied. The hospital records of 90 patients were analyzed both in the CMV cohort and also in the non-CMV cohort. Preoperative details, intraoperative parameters, immediate postsurgery echocardiography parameters, and follow-up echocardiography details at 1 year and 5 years were studied. RESULTS: Both the cohorts were similar in age, height, weight, and BSA. In the CMV cohort, 67% were females and in the non-CMV cohort 48% were females. Most of the patients in both the cohorts presented with functional classes 2 and 3. The mean duration between onset of symptoms and MVR in the CMV cohort and the non-CMV cohort was 24.6 years and 6.25 years, respectively. Fifty-nine patients in the CMV cohort had preoperative atrial fibrillation, whereas 47 patients in the non-CMV cohort presented with atrial fibrillation. The mean left atrial (LA) size of patients with sinus rhythm and atrial fibrillation was 46.34 (SE, 0.852) and 55.21(SE, 0.808), respectively. Preoperative echocardiographic assessment revealed a mean ejection fraction of 62% and 63%, mean mitral stenosis gradient of 13 mm Hg and 14.7 mm Hg, mean LA size of 53.2 mm and 50.5 mm, and mean right ventricular systolic pressure of 47.5 mm Hg and 43.6 mm Hg in the post-CMV cohort and in the non-CMV cohort, respectively. The CMV cohort had a longer cardiopulmonary bypass time (111.5 minutes) in comparison with the non-CMV cohort (97 minutes). The aortic cross-clamp time remained similar in both the cohorts. Thirty-six percent of the post-CMV cohort patients had a valve size of 25, and 48% of patients belonging to the non-CMV cohort had a valve size of 27. The percent of moderate-to-severe subvalvar pathology was 88 in both the cohorts. Patients belonging to the post-CMV cohort had a median ventilation time of 16.35 hours, and the patients of the non-CMV cohort had a median ventilation time of 13.75 hours. The duration of ICU stay was 4.41 (SE, 0.188) days and 4.13 (SE, 0.153) days, and length of hospital stay was 8.93 (SE, 0.230) days and 9.13 (SE, 0.313) days in the CMV and the non-CMV cohorts, respectively. Inotropic requirement, measured by the vasoactive inotropic score, was higher in the post-CMV group (11.9), when compared to the other cohort (9.7). Right ventricular (RV) function and pulmonary arterial hypertension assessed in the immediate postoperative period, at 1 year, and at 5 years did not show any significant difference. CONCLUSION: The percentage of females in the CMV cohort is higher. Delaying the valve replacement by performing a surgical palliative procedure like CMV, is beneficial in female patients in the child-bearing age group so that they can complete the families. The disease process started earlier in the CMV cohort, and they had a longer duration of illness before undergoing MVR. Even with the longer duration of disease, the RV function, LA size, PA pressures, and mitral stenosis gradients were comparable. Therefore, CMV prevented progression of the disease in the CMV group. The mean LA size is significantly higher in patients with atrial fibrillation. The CMV cohort had a longer cardiopulmonary bypass time. The duration of ventilation, ICU stay, and hospital stay were similar in both cohorts. Inotrope requirement was higher in the post-CMV group. RV function and pulmonary arterial hypertension assessed in the immediate postoperative period, at 1 year, and at 5 years did not show any significant difference.

A Cross-Sectional Investigation of Cognition and Ultrasound-Based Vascular Strain Indices.

OBJECTIVE: We examine the relationship between variability in the plaque strain distribution estimated using ultrasound with multiple cognitive domains including executive, language, visuospatial reasoning, and memory function. METHOD: Asymptomatic (n = 42) and symptomatic (n = 34) patients with significant (>60%) carotid artery stenosis were studied for plaque instability using ultrasound strain imaging and multiple cognitive domains including executive, language, visuospatial reasoning, and memory function. Correlation and ROC analyses were performed between ultrasound strain indices and cognitive function. Strain indices and cognition scores were also compared between symptomatic and asymptomatic patients to determine whether there are significant group differences. RESULTS: Association of high-strain distributions with dysexecutive function was observed in both asymptomatic and symptomatic patients. For memory, visuospatial, and language functions, the correlations between strain and cognition were weaker for the asymptomatic compared to symptomatic group. CONCLUSIONS: Both asymptomatic and symptomatic patients demonstrate a relationship between vessel strain indices and executive function indicating that silent strokes and micro-emboli could initially contribute to a decline in executive function, whereas strokes and transient ischemic attacks may cause the further decline in other cognitive functions.

Polylactic acid/chitosan films for packaging of Indian white prawn (Fenneropenaeus indicus).

Composite films were developed by embedding nanochitosan (0.5%, 1% and 2%) in a polylactic acid (PLA) matrix using polyethylene glycol as a cross linking agent and polyvinyl alcohol as plasticizer. The mixture was casted into films via solvent casting. The interaction between the polylactic acid/nanochitosan (PLA/NCS) and polyethylene glycol had a significant effect on the tensile strength and the heat sealing properties. Antimicrobial properties of PLA/NCS films have been confirmed against aerobic microorganisms. PLA/NCS solvent casted films were used to pack prawn meat (Fenneropeneaus indicus) which was further stored in chilled condition for 18 days. The study proved that microbial and biochemical quality indices of prawn samples packed in different PLA/NCS film were retained and concluded that PLA/NCS composite films can be used for packing of fresh prawn to increase its shelf life.

Risk Factors for Post-operative Complications in Primary Oral Cancer Surgery-a Prospective Study.

The surgical treatment of oral cavity cancers can be influenced by post-operative complications. Identification of risk factors based on clinical characteristics may assist in therapeutic planning and thereby helps in reducing complications. Here, an attempt is made to identify the factors associated with post-operative complications (complications developing within 1 month of surgery) in patients undergoing primary oral cancer surgery. Six hundred seventy-six consecutive patients who underwent primary surgery for oral cancer from December 2007 to May 2010 were prospectively evaluated. The risk factors that predict for post-operative complications were analyzed. There was one mortality and 15% (103 patients) had post-operative complications. The complications included metabolic complications, primary site problems, donor site problems, and systemic complications. Fifteen factors were found statistically significant for the development of post-operative complications by univariate analysis. On multivariate analysis, three of the 15 factors, i.e., presence of COPD, full thickness wide excision, and increased duration of surgery were found to be independently associated with the development of post-operative complications. Presence of COPD, full thickness wide excision, and increased duration of surgery were identified as independent risk factors for post-operative complications in primary oral cancer surgery. The development of complications invariably resulted in increased hospital stay. Hence, the prompt recognition of risk factors for complications based on pre-operative clinical characteristics plus the identification of the risks associated with the surgical procedure can help in determining the appropriate therapeutic planning to prevent complications and in achieving cost effectiveness.

Intraoperative Transesophageal and Postoperative Transthoracic Echocardiographic Evaluation of a Mechanical Heart Valve Prosthesis Implanted at Aortic Position.

OBJECTIVE: The aims of this study were to evaluate the intraoperative transesophageal echocardiographic (iTEE) characteristics and Doppler flow profile of aortic Chitra heart valve prosthesis (CHVP) under stable hemodynamic and loading conditions, and to compare and correlate the iTEE data with the postoperative transthoracic echocardiography (TTE) data obtained at 48 hours (TTE1) and 3 months (TTE2) after the surgery. DESIGN: Prospective, observational study. SETTING: University-level tertiary referral hospital. PARTICIPANTS: Forty patients between 18 years and 65 years of age undergoing elective aortic valve replacement (AVR) using CHVP during the period January 2015 to August 2016. INTERVENTIONS: After obtaining permission from institutional ethics committee, 40 patients undergoing elective AVR were studied prospectively. The iTEE examination was performed in the pre-cardiopulmonary bypass (CPB) and post-CPB period in all the study subjects. CHVP was subjected to iTEE two-dimensional (2D) echo, color Doppler, and spectral Doppler evaluation under stable hemodynamic and loading condition in the post-CPB period after the administration of protamine. The CHVP were re-evaluated using TTE in all the patients 48 hours after the surgery (TTE1) and 3 months after the surgery (TTE2). The iTEE and postoperative TTE Doppler values were compared and correlated. MEASUREMENTS AND MAIN RESULTS: The CHVP could be imaged adequately and interrogated with Doppler in all the patients. None of the patients had restriction of occluder mobility or unstable seating of the valve. The intraoperative flow dependent (peak velocity [PV] and mean pressure gradient [MPG]) and less flow dependent (Doppler velocity index, acceleration time, acceleration time/ejection time, effective orifice area [EOA] and indexed EOA) Doppler parameters of CHVP were measured as per the American Society of Echocardiography recommendations. The PV and MPG of CHVP measured by iTEE showed no statistical difference (p > 0.05) and were in limits of agreement when compared with TTE1 and TTE2 data. CONCLUSION: The iTEE features of CHVP were found compliant with the criteria set by the ASE defining normal functioning of an aortic valve prosthesis. The iTEE Doppler parameters obtained under stable loading conditions strongly predicted the postoperative values of Doppler parameters on TTE examination. The iTEE Doppler values can be used as the reference values for the postoperative follow up studies.

Assessment of Iron Deposition in the Brain in Frontotemporal Dementia and Its Correlation with Behavioral Traits.

BACKGROUND AND PURPOSE: Brain iron deposition has been implicated as a major culprit in the pathophysiology of neurodegeneration. However, the quantitative assessment of iron in behavioral variant frontotemporal dementia and primary progressive aphasia brains has not been performed, to our knowledge. The aim of our study was to investigate the characteristic iron levels in the frontotemporal dementia subtypes using susceptibility-weighted imaging and report its association with behavioral profiles. MATERIALS AND METHODS: This prospective study included 46 patients with frontotemporal dementia (34 with behavioral variant frontotemporal dementia and 12 with primary progressive aphasia) and 34 age-matched healthy controls. We performed behavioral and neuropsychological assessment in all the subjects. The quantitative iron load was determined on SWI in the superior frontal gyrus and temporal pole, precentral gyrus, basal ganglia, anterior cingulate, frontal white matter, head and body of the hippocampus, red nucleus, substantia nigra, insula, and dentate nucleus. A linear regression analysis was performed to correlate iron content and behavioral scores in patients. RESULTS: The iron content of the bilateral superior frontal and temporal gyri, anterior cingulate, putamen, right hemispheric precentral gyrus, insula, hippocampus, and red nucleus was higher in patients with behavioral variant frontotemporal dementia than in controls. Patients with primary progressive aphasia had increased iron levels in the left superior temporal gyrus. In addition, right superior frontal gyrus iron deposition discriminated behavioral variant frontotemporal dementia from primary progressive aphasia. A strong positive association was found between apathy and iron content in the superior frontal gyrus and disinhibition and iron content in the putamen. CONCLUSIONS: Quantitative assessment of iron deposition with SWI may serve as a new biomarker in the diagnostic work-up of frontotemporal dementia and help distinguish frontotemporal dementia subtypes.

Quantification of carotid artery plaque stability with multiple region of interest based ultrasound strain indices and relationship with cognition.

Vulnerability and instability in carotid artery plaque has been assessed based on strain variations using noninvasive ultrasound imaging. We previously demonstrated that carotid plaques with higher strain indices in a region of interest (ROI) correlated to patients with lower cognition, probably due to cerebrovascular emboli arising from these unstable plaques. This work attempts to characterize the strain distribution throughout the entire plaque region instead of being restricted to a single localized ROI. Multiple ROIs are selected within the entire plaque region, based on thresholds determined by the maximum and average strains in the entire plaque, enabling generation of additional relevant strain indices. Ultrasound strain imaging of carotid plaques, was performed on 60 human patients using an 18L6 transducer coupled to a Siemens Acuson S2000 system to acquire radiofrequency data over several cardiac cycles. Patients also underwent a battery of neuropsychological tests under a protocol based on National Institute of Neurological Disorders and Stroke and Canadian Stroke Network guidelines. Correlation of strain indices with composite cognitive index of executive function revealed a negative association relating high strain to poor cognition. Patients grouped into high and low cognition groups were then classified using these additional strain indices. One of our newer indices, namely the average L - 1 norm with plaque (AL1NWP) presented with significantly improved correlation with executive function when compared to our previously reported maximum accumulated strain indices. An optimal combination of three of the new indices generated classifiers of patient cognition with an area under the curve (AUC) of 0.880, 0.921 and 0.905 for all (n = 60), symptomatic (n = 33) and asymptomatic patients (n = 27) whereas classifiers using maximum accumulated strain indices alone provided AUC values of 0.817, 0.815 and 0.813 respectively.

Trends, practice patterns and underuse of surgery in the treatment of early stage small cell lung cancer.

BACKGROUND: Practice guidelines from the National Comprehensive Cancer Network and the American Society of Clinical Oncology recommend pathologic mediastinal staging and surgical resection for patients with clinically node-negative T1/T2 small cell lung cancer (SCLC), but the extent to which surgery is used is unknown. We sought to assess trends and practice patterns in the use of surgery for SCLC. METHODS: T1 or T2N0M0 SCLC cases were identified in the National Cancer Database (NCDB), 2004-2013. Characteristics of patients undergoing resection were analyzed. Hierarchical logistic regression was used to identify individual and hospital-level predictors of receipt of surgery, adjusting for clinical, demographic and facility characteristics. Trends in resection rates were analyzed over the study period. FINDINGS: 9740 patients were identified with clinical T1 or T2 N0M0 SCLC. Of these, 2210 underwent surgery (22.7%), with 1421 (64.3%) undergoing lobectomy, 739 (33.4%) sublobar resections and 50 (2.3%) pneumonectomies. After adjustment, Medicaid patients were less likely to receive surgery (OR0.65 95% CI 0.48-0.89, p=0.006), as were those with T2 tumors (OR0.25 CI0.22-0.29, p<0.0001). Academic facilities were more likely to resect eligible patients (OR 1.90 CI1.45-2.49, p<0.0001). Between 2004 and 2013, resection rates more than doubled from 9.1% to 21.7%. Overall, 68.7% of patients were not offered surgery despite having no identifiable contraindication. In patients not receiving surgery, only 7% underwent pathologic mediastinal staging. INTERPRETATION: Rates of resection are increasing, but two thirds of potentially eligible patients fail to undergo surgery. Further study is required to address the lack of concordance between guidelines and practice.

Surgery Versus Chemotherapy and Radiotherapy For Early and Locally Advanced Small Cell Lung Cancer: A Propensity-Matched Analysis of Survival.

BACKGROUND: The role of surgery in small cell lung cancer (SCLC) is controversial. Survival outcomes for resection of stage I-IIIA SCLC compared to chemotherapy-based non-surgical treatment (NST) were examined using propensity matching. METHODS: 29,994 clinical stage I-IIIA SCLC patients, including 2,619 undergoing surgery, were identified in the National Cancer Database. Stage-specific propensity scores for receipt of surgery were created. Resected patients were matched 1:1 to those undergoing NST. Overall survival (OS) was assessed using Kaplan-Meier and multivariable Cox models. A separate match was performed comparing Stage I/II patients aged <85 with a Charlson score of 0 who underwent lobectomy with adjuvant chemotherapy (and radiotherapy if node positive) to those treated with multiagent chemotherapy and concurrent chest radiotherapy (CRT) of at least 40 gray. RESULTS: 2,089 patients were matched, and cohorts were well balanced. Surgery was associated with longer survival for Stage I (median OS 38.6 months vs. 22.9 months, HR 0.62 95%CI 0.57-0.69, p<0.0001), but survival differences were attenuated for Stage II (median OS 23.4 months vs. 20.7 months, HR 0.84 95%CI 0.70-1.01, p=0.06) and IIIA (median OS 21.7 vs. 16.0 months, HR 0.71 95%CI 0.60-0.83, p <0.0001). In analyses by T and N stage, longer OS was observed in resected patients with stage T3/T4 N0 (median OS 33.0 vs. 16.8 months, p=0.008) and node positivity(N1+ 24.4 vs. 18.3 months p=0.03; N2+ 20.1 vs. 14.6 months p=0.007). In the subgroup analysis, 507 stage I/II patients receiving lobectomy and adjuvant chemotherapy were matched to patients receiving concurrent CRT. In this cohort, lobectomy with adjuvant chemotherapy was associated with significantly longer survival (median OS 48.6 vs. 28.7 months, p<0.0001). CONCLUSIONS: Surgical resection is associated with significantly longer survival for early SCLC. New randomized trials should assess trimodality therapy in stages I/II, and in node negative disease.

UV protective poly(lactic acid)/rosin films for sustainable packaging.

Recently, biopolymer based plastic materials are regarded as potential alternative for conventional plastics of fossil fuel origin in order to compensate depleting petroleum resources and address environmental pollution issues. Poly(lactic acid) (PLA) is one among the biopolymers which is rapidly commercialized for food packaging application. However, the demerits accompanied with PLA like brittle nature, slower crystallization rate, poor gas barrier and high ultraviolet radiation transmission properties confines its commercial application in food packaging sector. Studies on the improvement of ductility, crystallization rate and gas barrier properties are markedly reported. Much emphasis is not given in the literature on improving UV shielding properties which plays important role in preventing oxidation degradation of PLA. Therefore, the current work is focused on fabrication of eco-friendly poly(lactic acid)/rosin (RS) based biocomposite films with improved UV shielding along with ductility and oxygen barrier properties. The PLA-RS biocomposite films containing different loadings (1, 3, 5, 10 and 20wt%) of RS with an average thickness of 50µm are fabricated via solution casting technique. The PLA-RS film demonstrated noteworthy light barrier feature by shielding the passage of ∼98%, 92% and 53% in UV-B, UV-A and visible light regime, respectively. In case of UV-C region, complete blockage of UV transmission through the PLA-RS biocomposite film is noticed. In addition to this, the presence of RS in the PLA matrix brought considerable improvement in terms of ductility and oxygen barrier characteristics. This in turn indicates PLA-RS biocomposite films hold significant potential for sustainable food packaging application.

Influence of electron beam irradiation on structural and optical properties of α-Ag2WO4 nanoparticles.

The influence of 8MeV electron beam irradiation on the structural and optical properties of silver tungstate (α-Ag2WO4) nanoparticles synthesized by chemical precipitation method was investigated. The dose dependent effect of electron irradiation was investigated by various characterization techniques such as, X-ray diffraction, scanning electron microscopy, UV-vis absorption spectroscopy, photoluminescence and Raman spectroscopy. Systematic studies confirm that electron beam irradiation induces non-stoichiometry, defects and particle size variation on α-Ag2WO4, which in turn results changes in optical band gap, photoluminescence spectra and Raman bands.

OfftargetFinder: a web tool for species-specific RNAi design.

MOTIVATION: RNA interference (RNAi) technology is being developed as a weapon for pest insect control. To maximize the specificity that such an approach affords we have developed a bioinformatic web tool that searches the ever-growing arthropod transcriptome databases so that pest-specific RNAi sequences can be identified. This will help technology developers finesse the design of RNAi sequences and suggests which non-target species should be assessed in the risk assessment process. AVAILABILITY AND IMPLEMENTATION: http://rnai.specifly.org CONTACT: crobin@unimelb.edu.au.

Improved Correlation of Strain Indices with Cognitive Dysfunction with Inclusion of Adventitial Layer with Carotid Plaque.

Plaque instability may lead to chronic embolization, which in turn may contribute to progressive cognitive decline. Accumulated strain tensor indices over a cardiac cycle within a pulsating carotid plaque may be viable biomarkers for the diagnosis of plaque instability. Using plaque-only carotid artery segmentations, we recently demonstrated that impaired cognitive function correlated significantly with maximum axial and lateral strain indices within a localized region of interest in plaque. Inclusion of the adventitial layer focuses our strain or instability measures on the vessel wall-plaque interface hypothesized to be a region with increased shearing forces and measureable instability. A hierarchical block-matching motion tracking algorithm developed in our laboratory was used to estimate accumulated axial, lateral, and shear strain distribution in plaques identified with the plaque-with-adventitia segmentation. Correlations of strain indices to the Repeatable Battery for the Assessment of Neuropsychological Status Total score were performed and compared with previous results. Overall, correlation coefficients (r) and significance (p) values improved for axial, lateral, and shear strain indices. Shear strain indices, however, demonstrated the largest improvement. The Pearson correlation coefficients for maximum shear strain and cognition improved from the previous plaque-only analyses of -0.432 and -0.345 to -0.795 and -0.717 with the plaque-with-adventitia segmentation for the symptomatic group and for all patients combined, respectively. Our results demonstrate the advantage of including adventitia for ultrasound carotid strain imaging providing improved association to parameters assessing cognitive impairment in patients. This supports theories of the importance of the vessel wall plaque interface in the pathophysiology of embolic disease.

Comparative Evaluation of Dimensional Accuracy of Elastomeric Impression Materials when Treated with Autoclave, Microwave, and Chemical Disinfection.

BACKGROUND: Impression materials during impression procedure often get infected with various infectious diseases. Hence, disinfection of impression materials with various disinfectants is advised to protect the dental team. Disinfection can alter the dimensional accuracy of impression materials. The present study was aimed to evaluate the dimensional accuracy of elastomeric impression materials when treated with different disinfectants; autoclave, chemical, and microwave method. MATERIALS AND METHODS: The impression materials used for the study were, dentsply aquasil (addition silicone polyvinylsiloxane syringe and putty), zetaplus (condensation silicone putty and light body), and impregum penta soft (polyether). All impressions were made according to manufacturer's instructions. Dimensional changes were measured before and after different disinfection procedures. RESULT: Dentsply aquasil showed smallest dimensional change (-0.0046%) and impregum penta soft highest linear dimensional changes (-0.026%). All the tested elastomeric impression materials showed some degree of dimensional changes. CONCLUSION: The present study showed that all the disinfection procedures produce minor dimensional changes of impression material. However, it was within American Dental Association specification. Hence, steam autoclaving and microwave method can be used as an alternative method to chemical sterilization as an effective method.

Development and characterization of an LDPE/chitosan composite antimicrobial film for chilled fish storage.

An antimicrobial packaging material was developed by uniformly embedding 1, 3 and 5% chitosan (w/w) in low density polyethylene matrix using maleic anhydride grafted LDPE as a compatible agent. The materials were mixed by compounding and blown into monolayer films via blown film extrusion. The developed films showed good barrier properties against oxygen. Characterization of the composite films with Fourier transform infrared spectroscopy revealed that chitosan and LDPE interacted well with each other. Overall migration showed better release of chitosan adduct from the LDPE matrix which enhanced the antibacterial properties of the films. The interaction between the LDPE/CS and maleic anhydride grafted LDPE had a decreasing effect on the tensile strength and heat sealing properties. Investigation on antimicrobial properties of LDPE/CS films showed 85-100% inhibition of Escherichia coli. Efficacy of LDPE/CS films was evaluated by using them as packaging material for chilled storage of Tilapia (Oreochromis mossambicus). Analysis of storage quality indices (peroxide value, free fatty acid, total volatile base nitrogen and aerobic plate count) revealed good antibacterial property and extension of shelf life of Tilapia in the chitosan incorporated novel composite films compared to virgin LDPE film.