Midpoint Research Articles

Energy-Efficient Design of MI Communication-Based 3-D Non-Conventional WSNs

This paper proposes optimal clustering (OC) for magnetic induction (MI) communication-based 3-D Non-Conventional Wireless Sensor Networks (3-D Non-Conv WSNs) leveraging compressive sensing (CS) and principal component analysis (PCA) with and without consideration of relay node. These WSNs are resource constrained with limited energy reserves. OC for 3-D media is performed using analytical modeling to minimize the energy consumption in the network. Clustering efficacy is further improved by applying the CS and PCA data compression techniques. The performance of the proposed model is evaluated in terms of energy efficiency and network lifetime for three different media (viz., sea water, dry soil, and sedimentary wet rock) by considering three different positions of base station (BS) (viz., center, lateral mid point, and outside of sensing field). Furthermore, from the results, we observed that our proposed techniques save energy up to $\text{84.37}{\%}$ for all base station (BS) positions.

Clinical application of the lateral branch of lateral circumflex femoral artery in the anterolateral thigh perforator flap

Objective To investigate the feasibility and technique of using the anterolateral thigh perforator flap pedicled with the lateral branch of the lateral circumflex femoral artery (LBLCFA) to repair soft tissue defect of extremities. Methods Eighty-six cases of anterolateral thigh perforator flap transplantation were performed from May, 2014 to May, 2018. A total of 37 cases of soft tissue defect of extremities were treated by anterolateral thigh perforator flap used the LBLCFA as vascular pedicle, of which there were 19 cases of upper limbs and 18 of lower limbs. There were 27 cases of defects caused by trauma, and 10 by soft tissue tumor resection. The flaps were designed centering around the point proximal to the midpoint of the iliac-patellar line. The dimensions of soft tissue defect were from 9.0 cm×6.0 cm to 26.0 cm×10.0 cm, and the flap were from 10.0 cm×7.0 cm to 27.0 cm×11.0 cm. The length of vascular pedicle ranged of 7.0-13.0 cm, with an average of 11.5 cm. The donor sites were directly sutured. All of the patients were followed-up regularly in the outpatient department. Results All the flaps survived and the donor sites were primarily healed. Of these 37 cases, 2 trauma patients and 2 patients treated with local radiotherapy had poor wound healing, but still healed after multiple dressing changes. All the patients were followed-up for 3-26 months, with an average of 13 months. The texture, color and elasticity of the flap were similar to the surrounding tissue of the recipient sites, while only a linear scar remained at the donor sites. Ten tumor patients were treated with routine radiotherapy and chemotherapy after the repairation; there was no tumor recurrence during the follow-up period. Conclusion The LBLCFA gives off a relatively large and thick perforator proximal 5.0-7.0 cm of the iliac-patellar line, which locates in the upper lateral side, travels parallel to the vastus lateralis, and give off the skin and muscular perforators. The lateral branch can be used as pedicle to make into perforator flap or chimeric flap, which provides a novel selection of vascular pedicel for anterolateral thigh perforator flap. When the descending branch does not provide a thick and large perforator, the LBLCFA has important practical value and is worth utilizing in the clinic. Key words: Lateral branch, lateral circumflex femoral artery; Anterolateral thigh flap; Tissue transplantation; Microsurgical technique

Three ways of inserting the anteroinferior iliac spine channel screws: a computer simulation comparison

Objective To compare the safely between 3 ways of inserting the anteroinferior iliac spine channel screws using computer simulation. Methods The spiral pelvic CT data of 100 patients were collected who had sought medical treatment at General Hospital of The Northern Theater Command from October 2017 to October 2018. They were 61 males and 39 females, aged from 20 to 60 years (average, 47.5 years). The data were imported into Mimics (Materi-alise, Belgium) software to create three-dimensional models of the pelvis. The pelvic modeling data were then imported into 3-Matic (Materi-alise, Belgium) software for post-processing. Three cylinders with a diameter of 6.7 mm were created, taking the anteroinferior iliac spine as the entry point and taking the posterosuperior iliac spine, the posteroinferior iliac spine and the midpoint between the 2 spines as the 3 exit points. The insertion of anteroinferior iliac spine channel screws was simulated to observe the screw penetration. Results In the channel from the anteroinferior iliac spine to the posterosuperior iliac spine, penetration occurred in 41 cases out of the medial ilium and in 2 cases out of the lateral ilium, giving a penetration rate of 43% (43/100); in the channel from the anteroinferior iliac spine to the midpoint between the 2 spines, penetration occurred in 16 cases out of the medial ilium and in 2 cases out of the lateral ilium, giving a penetration rate of 18% (18/100); in the channel from the anteroinferior iliac spine to the posteroinferior iliac spine, penetration occurred in 6 cases out of the medial ilium, in 2 cases out of the lateral ilium, in 60 cases out of the greater sciatic notch and in 8 cases out of both the medial ilium and greater sciatic notch, giving a penetration rate of 76% (76/100). There were significant differences between the 3 ways of insertion in the screw penetration (χ2=68.219, P<0.001). The rate of screw penetration in the channel from the anteroinferior iliac spine to the posteroinferior iliac spine was significantly higher than that in the channel from the anteroinferior iliac spine to the posterosuperior iliac spine which was significantly higher than that in the channel from the anteroinferior iliac spine to the midpoint between the 2 spines (P<0.05). Conclusions The channel from the anteroinferior iliac spine to the midpoint between the posterosuperior iliac spine and the posteroinferior iliac spine may lead to a lower rate of screw penetration while the channel from the anteroinferior iliac spine to the posteroinferior iliac spine may lead to a higher rate of screw penetration. Key words: Pelvis; Bone nails; Safe passage; Morphology

USE OF GROUND PENETRATING RADAR TO STUDY SPATIAL VARIABILITY AND SOIL STRATIGRAPHY

ABSTRACT Ground Penetrating Radar (GPR) is a geophysical method that uses electromagnetic waves to study subsurface structure in different fields such as geology, agriculture and civil engineering. The wave penetration in the soil is strongly controlled by the electrical conductivity of soil components such as clay, organic matter, and water. In this study, tests were conducted in a floodplain in the Elizabeth Creek watershed (New Jersey – USA). We established one transect where measurements were completed using two techniques, common mid point (CMP) and constant offset profile (COP), both with 100- MHz frequency antennas. Measurements were also completed using 250 and 500 MHz shielded antennas. GPR showed good accuracy to study soil spatial variability and stratigraphy. Antennas of a higher frequency had less vertical investigation capacity and greater accuracy. In this study, it was not possible to clearly differentiate signals from organic matter and clay; this was the main limitation of the GPR system.

A novel similarity measure between intuitionistic fuzzy sets based on the mid points of transformed triangular fuzzy numbers with applications to pattern recognition and medical diagnosis

Similarity measure is an essential tool to compare and determine the degree of similarity between intuitionistic fuzzy sets (IFSs). In this paper, a new similarity measure between intuitionistic fuzzy sets based on the mid points of transformed triangular fuzzy numbers is proposed. The proposed similarity measure provides reasonable results not only for the sets available in the literature but also gives very reasonable results, especially for fuzzy sets as well as for most intuitionistic fuzzy sets. To provide supportive evidence, the proposed similarity measure is tested on certain sets available in literature and is also applied to pattern recognition and medical diagnosis problems. It is observed that the proposed similarity measure provides a very intuitive quantification.

Comparison of various robust and efficient load-flow techniques based on Runge–Kutta formulas

Based on Continuous Newton’s method, any well-assessed numerical scheme can be adapted for solving the Load-Flow (LF) problem. So far, LF techniques based on 4th order Runge–Kutta formula (RK4) and Adams–Bashfort’s methods (AB) have been proposed. However, there is a huge variety of numerical methods whose adequacy for solving the LF problem has not been explored yet. This paper tries to fill this gap by proposing several LF solvers based on Runge–Kutta (RK) formulas. Thus, several LF techniques based on Midpoint (MP), 3rd order Heun (H3), Simpson 3/8 (S3/8) and an accelerated 3rd order Runge–Kutta (ARK3) formulas are proposed. The performance of the proposed LF techniques is assessed using several medium and large-scale ill-conditioned power systems. The proposed techniques are compared with RK4, AB and other robust LF methods. In addition, their scalability and influence of the loading level are analyzed. The obtained results prove that the proposed LF techniques are faster than RK4 and robust enough to successfully tackle medium and large-scale ill-conditioned power systems. As main conclusion, it is proved that lower order methods might be as robust as higher order ones but more efficient. Therefore, its usage with respect higher order methods (e.g. 4th order ones), should be frequently preferable.

Shortest Dubins paths through three points

The 3-Point Dubins Problem (3PDP) consists of steering a Dubins vehicle through three consecutive points with prescribed heading orientations at initial and final points so that the resulting path is the shortest. Characterizing the path of the 3PDP is important because (1) it provides insightful views on the solution paths of the Dubins Traveling Salesman Problem (DTSP) and the Curvature-Constrained Shortest-Path Problem (CCSPP) as they are natural extensions of the 3PDP and (2) some algorithms in the literature for solving the DTSP and the CCSPP require efficient methods for solving the 3PDP. In this paper, Pontryagin’s maximum principle is used to show that the path of 3PDP must lie in a sufficient family of 18 types. Moreover, a formula in terms of the parameters of the 3PDP for all the 18 types is established, and this formula reveals the relationship between the unknown orientation angle at mid point and known parameters. By observing that the formula can be converted into some polynomials, the 3PDP can therefore be efficiently solved by finding zeros of those polynomials. Finally, numerical simulations illustrate the developments by comparing with the straightforward discretization-based method.

Efficacy of ultrasound-prepositioned four-point method for right internal jugular vein catheterization in parturients at high risk of bleeding

Objective To evaluate the efficacy of ultrasound-prepositioned four-point method for right internal jugular vein (IJV) catheterization in the parturients at high risk of bleeding. Methods Eighty American Society of Anesthesiologists physical status Ⅰ or Ⅱparturients diagnosed as having pernicious placenta previa, aged 25-38 yr, weighing 60-90 kg, scheduled for elective cesarean section under general anesthesia, were divided into 2 groups (n=40 each) using a random number table method: real-time ultrasonic guidance group (group UG) and ultrasound-prepositioned four-point method group (group UF). In group UG, the right IJV catheterization was performed under real-time ultrasound guidance: moving the ultrasonic probe to make the mid-line of the cross section image of the right IJV overlap with the mid-line of the ultrasonic display screen, and the intersection of the mid-line of the IJV and the horizontal line of the annular cartilage was selected as the puncture point.In group UF, the right IJV catheterization was performed by using ultrasound-prepositioned four-point method as follows: moving the ultrasonic probe to make the midline of the right IJV cross-sectional images overlap with the midline of the ultrasound display screen, and marking the skin where the midpoint of the probe′s long-axis was located as point A; transversely moving the probe to the inside so that the tangent line of its inner edge overlapped with the midline of the ultrasonic display screen, marking the skin where the midpoint of the probe′s long-axis was located as point B (the puncture site); at the proximal cardiac end of the right IJV, making point C at 2 cm from point B, and making point D (the indicator point, direction of the puncture needle) at 2 cm from point A. After local infiltration anesthesia was performed in point B, the puncture needle was inserted towards the point D. The success rate of puncture, success rate of catheterization, catheterization operation time and complications such as hematoma, intravascular catheter insertion or hemopneumothorax were recorded. Results The success rate of total catheterization was 100% in two groups.Compared with group UG, the catheterization operation time was significantly shortened (P 0.05). Conclusion Compared with real-time ultrasound guidance, ultrasound-prepositioned four-point method produces better efficacy when used for the right IJV catheterization in the parturients at high risk of bleeding. Key words: Ultrasonography; Catheterization, central venous; Cesarean section

Three-dimensional evaluation of labial alveolar bone overlying the maxillary and mandibular incisors in different skeletal classifications of malocclusion

The purpose of this study was to investigate differences in the thickness of the labial bone overlying the maxillary and mandibular incisors in class I, II, and III skeletal classifications using three-dimensional cone-beam computed tomographs (CBCT) technology. Pretreatment CBCTs of 54 Caucasian subjects (44 males, 10 females) were collected from the archives of a graduate orthodontic clinic. The subjects were divided into three groups based on their skeletal classification. CBCT scans were oriented to the long axis of each maxillary and mandibular incisor from the root apex to incisal tip and the axial inclination of each incisor was measured and recorded. Labial bone thickness was measured at the apex (A) and at the midpoint (MP) on each maxillary and mandibular incisor. A linear measurement, perpendicular to the long axis, was recorded from the labial bone surface to the most anterior root surface at two points. The effects of skeletal classification, jaw, incisor position, and side on A, MP, and Inclination were evaluated using mixed-model ANOVA. A 5% significance level was used for all tests. Significantly greater bone thickness at the apex and midpoint was reported in class III individuals than class I or II. Central incisors had significantly greater bone thickness at both the root apex and midpoint. Significantly greater bone thickness was noted in the mandible at the level of the apex. At the level of the midpoint, significantly greater thickness was reported in the maxilla. There was a positive correlation between thickness and angle within each jaw-incisor combination for class I patients and for central incisors in class III patients. The thickness of labial alveolar bone over the incisors varies based on the underlying skeletal discrepancy in each patient. Skeletal discrepancy influences the inclination of the maxillary and mandibular incisors.

Some new hermite-hadamard type inequalities and their applications

Abstract In this paper first, we prove some new generalizations of Hermite-Hadamard type inequalities for the convex function f and for (s, m)-convex function f in the second sense in conformable fractional integral forms. Second, by using five new integral identities, we present some new Riemann-Liouville fractional trapezoid and midpoint type inequalities. Third, using these results, we present applications to f-divergence measures. At the end, some new bounds for special means of different positive real numbers and new error estimates for the trapezoidal and midpoint formula are provided as well. These results give us the generalizations of the earlier results.

Combined bending-tension/compression deformation of micro-bars accounting for strain-driven long-range interactions

The paper aims to investigate combined bending-tension/compression deformation of a micro-bar. The strain-driven nonlocal differential model which involves information about long-range interactions between atoms is used to develop the mechanical model and theoretical formulations. Subsequently, effects of internal long-range scale parameter, length of micro-bar, external loads and bending rigidity on combined deformation are shown and discussed. In particular, the upper bound of internal longrange scale parameter and the buckling load are achieved during bending-compression analyses. It is demonstrated that the existence of internal scale parameter or axial tensile load decreases combined deformation. The deflection at the midpoint reduces with increasing bending rigidity, while it rises with increasing length of the microbar. Additionally, an effect of the acting position of transverse load on combined deformation is discussed and deflection at the symmetry point of transverse acting position is achieved. When the long-range interaction is taken into consideration, the equivalent stiffness of the micro-bar subjected to combined bending-tension is stiffer than that predicted by classical mechanics, and it validates the existing nonlocal hardening model. The combined bending-compression of the micro-bar reveals that the deflection may increase or decrease with an increase in the long-range scale or structural length, which verifies both the nonlocal softening and hardening models.

Analysis of anatomical characteristics of upper airway in Pierre Robin sequence pediatric patients with difficult laryngoscopy: computed tomography-based three-dimensional reconstruction

Objective To analyze the anatomical characteristics of the upper airway in Pierre Robin sequence pediatric patients with difficult laryngoscopy using the computed tomography-based three-dimensional reconstruction. Methods Fifty pediatric patients of both sexes with Pierre Robin sequence, aged 10-101 days, weighing 2.0-6.3 kg, of American Society of Anesthesiologists physical status Ⅲ, scheduled for elective mandibular distraction osteogenesis under general anesthesia, were enrolled in this study.Cone beam CT scan was performed to obtain upper airway anatomy information during the natural sleep before operation.Images were imported into medical engineering software MIMICS 17.0 to reconstruct the three-dimensional images of the oral and maxillofacial bones and airways.The related anatomical parameters were measured, including the distance between the alveolar ridge of the upper central incisor and root of the epiglottis(D1), distance between the root of the epiglottis and midpoint of glottis(D2), distance between the bilateral lower edge of the mandible and midpoint of glottis(D3), distance between the alveolar ridge of the lower central incisor and the lower edge of the mandible(D4), length of the mandibular ramus(D5), length of the mandible body(D6), and length of the total mandible(D7), angle between lines D1 and D2(angle 1), the angle between line D2 and the alveolar ridge of the upper central incisor to the midpoint of glottis(angle 2), the angle between lines D3 and D4(angle 3), the angle of the point of the upper central incisor alveolar ridge to the trailing edge of the hard palate and then to the root of epiglottis(angle 4), the angle of bilateral mandible(angle 5), the angle of the point of gnathion to the two gonions(angle 6), the airway cross-sectional area at the tip of epiglottis, volume of oral cavity, volume of velopharyngeal cavity, and volume of glossopharyngeal cavity.Fiberoptic bronchoscope-guided endotracheal intubation was performed under topical anesthesia with lidocaine.Propofol, sufentanil and cis-atracurium were intravenously injected to induce anesthesia after successful intubation, and then the pediatric patients were sent to the operating room.Anesthesia was maintained by inhalation of sevoflurane.The exposure of glottis was observed with a laryngoscope.Pediatric patients were divided into difficult laryngoscopy group(group A) and non-difficult laryngoscopy group(group B) according to whether they presented with difficult laryngoscopy(Cormack-Lehane classification Ⅲ or Ⅳ ). Results Compared with group B, the airway cross-sectional area at the tip of epiglottis and in the volume of velopharyngeal cavity were decreased(P 0.05). Conclusion The three-dimensional CT images of the upper airway show characteristic changes in Pierre Robin sequence pediatric patients with difficult laryngoscopy, and the main manifestations are the decrease in the airway section area and in the volume of the palatopharyngeal cavity at the tip of the epiglottis. Key words: Pierre Robin syndrome; Laryngoscopy; Imaging, three-dimensional; Anatomy, regional

'The genome wager' at its midpoint: Implications for developmental biology.

Prediction is a very important part of the business of scientific theories, and scientists like to make wagers. Back in 2009, two prominent biologists within the public arena entered into a gentleman's bet about the explanatory value of the genome. Lewis Wolpert believes that, by 2029, it will be possible to predict all the physical details of a complex organism by the knowledge of its genome. Rupert Sheldrake, conversely, insists that new scientific principles are needed to explain development. It is also over a decade since Sean Carroll formalized the cis-regulatory hypothesis of morphological evolution. This paradigm, whereby major changes in form are produced by small variations in regulatory DNA, is congruent with Wolpert's own understanding of the genome. Research conducted over the past decade, however, suggests that a gene-centred approach to developmental evolution may be fading, but there is still much to work on. Far from being eccentric, the wager's outcome could affect the future course of the field of developmental biology.

A novel approach to estimate age and sex from mri measurement of liver dimensions in an Indian (Bengali) Population – A pilot study

Radiological methods have been used to assess the ossification stages of bones to estimate age and sex, but studies using the growth stages of organs such as the liver for identification purposes have not yet been performed. Liver weight increases with age, reaching a maximum between 41 and 50 years in men and between 51 and 60 years in women. Thereafter, above the age of 50 years, the liver weight decreases again, and the differences in liver weight between men and women are lost. For this reason, we have conducted this study in a population aged between 10 and 40 years. In this study, we attempted to find correlations between liver dimensions (from magnetic resonance imaging [MRI] images) and age and sex in an eastern Indian (Bengali) population. MRI images showing the liver were acquired from people aged between 10 and 40 years visiting the MRI Centre of Calcutta National Medical College. Liver MRI was acquired from 104 people. Chi-square tests showed a significant correlation between age and the mid hepatic point anteroposterior (MHP AP) dimension. However, there was no such significant correlation between age and maximum craniocaudal (Max CC) dimension or between age and maximum transverse dimension. The following discriminant function equation was derived (Df) = 0.04 MHP AP + 0.006 Max CC + 0.031 Max transverse −11.873 (Constant). Using this formula, 60.6% of the original grouped cases from the Eastern Indian Bengali population would be correctly classified. From the forensic point of view, the dimensions of the liver may be of the value of corroborating age and sex in doubtful cases in living individuals, aged between 10 and 40 years.

Fractional Ostrowski type inequalities for functions whose derivatives are s-preinvex

In this paper, some new fractional Ostrowski's inequalities for functions whose first derivatives in absolute value are $MT$-preinvex are established, mid point inequalities are also derived.

Ultrasonographic analysis of the anatomical relationship between femoral vessels in the upper part of thigh in critically ill patients– a cross sectional study

Objective: Femoral vessels are one of the frequently used sites of cannulation in intensive care units. In resource limited settings cannulations are done blindly without ultrasonographic guidance based on a traditional belief that in the upper thigh vein keeps a medial relationship to artery. In this trial we tried to analyse the anatomical relationship of femoral vein to femoral artery using ultrasound in critically ill patients. Methods: This cross sectional study analysed the anatomical relationship of femoral vein to femoral artery at 2cm, 4 cm and 6 cm from the mid inguinal point in both thighs of the patients using ultrasonography. The study was done among patients admitted in a multidisciplinary intensive care unit. Results: Three hundred limbs of one hundred and fifty patients were analysed by ultrasonography. A total of 900 measurements were taken at three different levels of both legs. At 2 cm below the mid inguinal point, in 256 limbs (85.3%) femoral vein was medial to femoral artery (95% Confidence Interval82.82% to 89.14%), at 4 cm below the mid inguinal point, in 210 limbs (70%) femoral vein was postero medial to femoral artery (95% CI64.47% to 75.13%),and at6 cm below the mid inguinal point in 200 limbs(66.7%)femoral vein was posterior to femoral artery(95% CI 61.02% to 71.98%). Conclusion: Femoral vein showed variable relationship to femoral artery in the upper part of the thigh. As the distance increased from mid inguinal point, variation from normal relationship was also found to be increasing.

Application of curved needling technique in the treatment of trigeminal neuralgia by radiofrequency ablation through foramen rotundum with inward opening

Objective To observe the application effect of radiofrequency puncture needle with individualized and on-demand plastic curved needle technique in the treatment of second-branch trigeminal neuralgia by radiofrequency ablation through foramen rotundum with inward opening. Methods From November 2012 to May 2018, a total of 263 cases of second-branch trigeminal neuralgia were admitted to Department of Anesthesiology, the First Hospital of Jiaxing and underwent foramen rotundum puncture for radiofrequency ablation. All those cases were enrolled into this retrospective analysis. The paranasal sinus model of CT was used to scan the pterygoid fossa with a thickness of 3 mm, and the CT images, including the midpoint of the foramen rotundum tube, the internal and external hole, were selected and the puncture path was designed. The length of the line (puncture depth) and the angle between the straight line and the sagittal plane (the angle of puncture) were measured by using the ruler tool of CT software from the external hole of the foramen rotundum along the lateral wall of the maxillary sinus to the surface of the skin (puncturing point). If the external hole of foramen rotundum demonstrated an inward opening, the angle between the line and the direction of the foramen rotundum tube(the angle of the needle needed to bend) should be measured. The radiofrequency needle was inserted 5 mm into the self-made needle-bender, the corresponding bending angle was pulled out slightly to the side of the needle at the tip of the needle, and the individual radiofrequency needle for the patient was made. Then, puncturing under the guidance of CT followed by designed trajectory. The arc of the needle was turned to the top of the front when the needle reached the external hole of the foramen rotundum. Whereafter, the arc of the needle was turned to the bottom when the needle crossed the external hole. Subsequently, the needle was pushed into the foramen rotundum. Then, electrophysiological test was conducted for radiofrequency treatment. Results Of 263 patients undergoing radiofrequency ablation of the second branch of trigeminal nerve, 71 (27.0%) had an inward opening of the external hole of foramen rotundum, which needed the patient's individually designed radiofrequency puncture needle. The average bending angle was 21.3 °±3.6 °(14°-31 °). When using the individual puncture needle, the needle tip could always reach the puncture target. Using 0.1-0.5 mA current could induce obvious muscle tremor or numbness in the region innervated by the second branch of trigeminal nerve in electrophysiological test. Following radiofrequency ablation, the second-branch trigeminal neuralgia disappeared completely. Ipsilateral palate muscosal numbness and the skin numbness involving the side of the nose, upper lip and zygomatic facial region were reported. None of the patients developed numbness involving the first or third branch of trigeminal nerve. A total of 242 patients were followed up for an average of 3.2±0.6 years. The total recurrence rates at 6 months, 1 year, 2 years, 3 years and 4 years were 2.5% (6/242), 7.9% (19/242), 16.1% (39/242), 24.4% (59/242) and 33.9% (82/242), respectively. Conclusions CT-guided individually made curved needle technology allows the radiofrequency needle tip to bypass the sphenoid bone which obstructs the outer opening of foramen rotundum and enter the middle of foramen rotundum tube with inward opening, so as to improve the radiofrequency effect and reduce the recurrence rate. Key words: Trigeminal neuralgia; Radiofrequency coagulation; Foramen rotundum; Treatment effect

Entire mitral valve reconstruction using porcine extracellular matrix: static in vitro evaluation.

To investigate the feasibility of reconstruction of the entire mitral valve using a tube graft made of 2-ply small intestinal submucosa extracellular matrix in vitro. Seven explanted mitral valves with intact subvalvular apparatus from 80 kg pigs were evaluated in a left heart simulator and served as controls. After testing the native valve, the leaflets and chordae tendineae were explanted, and the 2-ply small intestinal submucosa extracellular matrix (CorMatrix®; Cardiovascular Inc., Alpharetta, GA, USA) tube graft was implanted. The characterization was based on geometric data from digital images, papillary muscle force, annular tethering force and leaflet pressure force. The tube grafts were fully functional without any signs of leakage, tearing or rupture during incrementally increased pressures from 0 mmHg to 120 mmHg. The posterior leaflet moved anteriorly and became larger after reconstruction when compared with the native valve. However, the mid coaptation point was preserved. The anterior papillary muscle force decreased significantly (5.2 N vs 4.4 N, P = 0.022 at 120 mmHg), and the posterior papillary muscle force increased significantly (4.8 N vs 5.6 N, P = 0.017 at 120 mmHg) after reconstruction. The entire mitral valvular and subvalvular reconstruction with a 2-ply small intestinal submucosa extracellular matrix tube graft is feasible in an in vitro model. Our method of reconstruction increased the convexity of the anterior leaflet's coaptation line and significantly redistributed the papillary muscle force towards the posterior papillary muscle. These promising results and the prospect of the entire mitral valvular and subvalvular reconstruction warrant further in vivo evaluations.

Significant increase in the dominant lethal mutations: benzo(a)pyrene

Background: Use of biomarkers particularly under in vivo condition is of importance in risk assessment. This study is proposed to identify the in vivo antigenotoxic potential using dominant lethal mutation test in B(a)P exposed, turmeric fed animals and evaluate the role of turmeric in counteracting the germ cell mutations. Methods: Twenty four male mice were taken and divided into 4 groups each group containing 6 mice/group. The first and second group received stock diet (control) while the third and fourth groups received 5% turmeric diet for a period of one month. At the end of feeding period, second and fourth group received a single dose of benzo(a)pyrene 1mg/mouse intraperitoneally. After 1 week each male mouse was mated to 3 female mice at 1,4, 8 and 12 week intervals. On 13th day from mid point of mating, the females were sacrificed and live and dead embryos were counted to study the pre and post implantation loss of embryos. The differences in the frequencies of pre and post implant deaths were done by comparing treated with control group at 4-time periods by analysis of variance (ANOVA) and chi-square test which is used to compare treatment group and positive control with negative control. Results: Feeding of 5% turmeric and treatment with a single dose of B(a)P did not show any significant effect on the mutagenic index or the frequency of pregnancy in treated groups compared with control. There was no apparent induction of dominant lethal mutations in B(a)P or B(a)P+Turmeric treated groups. No post implantation dominant lethal effects produced by B(a)P could be detected in this study. The induction of B(a)P and treatment with turmeric did not influence the dominant lethal test. Conclusion: B(a)P did not produce a significant increase in the dominant lethal mutations. Turmeric also did not give any positive response and may be considered as non-mutagenic. The negative result suggests that under the conditions of the test the test substance may not be genotoxic in the germ cell of the treated sex of the test species.

When is a Vestibular Aqueduct Enlarged?

A ten-year-old boy with bilateral moderate sensorineural hearing loss underwent computerized tomographic (CT) imaging (GE Brightspeed, Wisconsin, USA) of the temporal bone as part of the work-up to determine the etiology of his condition. The formal radiologic interpretation of the scan stated that the vestibular aqueducts were not enlarged. However, independent review of the axial CT images appeared to indicate the presence of enlarged vestibular aqueducts. (Figure 1) This can be contrasted with a scan from another patient with no evidence of sensorineural hearing loss. (Figure 2)&#x0D; What can explain the discrepancy between the two?&#x0D; &#x0D; If simple visual inspection of the vestibular aqueduct (VA) can lead to conflicting interpretations, then what radiographic parameters can be used to resolve the issue? Is there a more objective means of determining the presence of a clinically significant vestibular aqueduct enlargement?&#x0D; &#x0D; In 1978, Valvasorri and Clemis1 first described an association between congenital sensorineural hearing loss and an abnormality in vestibular aqueduct anatomy which they labelled as the “large vestibular aqueduct syndrome.” In this landmark study that utilized hypocycloidal polytomographic temporal bone studies, they proposed that a vestibular aqueduct is enlarged when its midpoint diameter is greater than 1.5 mm. Although this parameter is generally considered to be the defining characteristic of the condition, one must realize that this measurement was based on less accurate imaging technology and measurement tools. Contemporary studies utilize high-resolution CT imaging with digital workstation measurement software to evaluate vestibular aqueduct anatomy. Currently, the two most commonly used radiographic parameters are the VA midpoint (MP) width and the VA opercular (OP) width. (Figure 3)&#x0D; More recently, Boston et al.2 in 2007 published normative values for these parameters based on a study population of 73 children without known sensorineural hearing loss. They considered a vestibular aqueduct enlarged when one or both of the measured widths were above the 95th percentile of the normal study group measurements. On this basis, a VA midpoint width of &gt;0.9 mm and/or a VA opercular width of &gt;1.9 mm was the criteria established to define an enlarged vestibular aqueduct.&#x0D; &#x0D; The patient’s measured vestibular aqueduct midpoint width on the right was 2.1 mm, while the vestibular aqueduct opercular width was 2.9 mm. (Figure 4) These measurements, when evaluated against either the original Valvassori criteria or the newer criteria of Boston et al., confirm what was visually apparent– the presence of a clinically significant enlargement of the vestibular aqueduct as the etiology of the patient’s sensorineural hearing loss.&#x0D;