Myxoid Neurothekeoma of the Nipple

Neurothekeomas are rare benign cutaneous neoplasms of nerve sheath origin. They are primarily found in the superficial soft tissue and are also known as dermal nerve sheath myxomas. They are commonly found on the upper extremities, head and neck followed by trunk. Here is an unusual presentation of neurothekeoma occurring as a polypoidal lesion of the nipple in a young female patient

An equivalent domain integral method for three-dimensional mixed-mode fracture problems

A general formulation of the equivalent domain integral (EDI) method for mixed mode fracture problems in cracked solids is presented. The method is discussed in the context of a 3-D finite element analysis. The J integral consists of two parts: the volume integral of the crack front potential over a torus enclosing the crack front and the crack surface integral due to the crack front potential plus the crack face loading. In mixed mode crack problems the total J integral is split into J sub I, J sub II, and J sub III representing the severity of the crack front in three modes of deformations. The direct and decomposition methods are used to separate the modes. These two methods were applied to several mixed mode fracture problems, were analyzed, and results were found to agree well with those available in the literature. The method lends itself to be used as a post-processing subroutine in a general purpose finite element program

Treatment of singularities in cracked bodies

Three-dimensional finite-element analyses of middle-crack tension (M-T) and bend specimens subjected to mode I loadings were performed to study the stress singularity along the crack front. The specimen was modeled using 20-node isoparametric elements. The displacements and stresses from the analysis were used to estimate the power of singularities using a log-log regression analysis along the crack front. The analyses showed that finite-sized cracked bodies have two singular stress fields of the form rho = C sub o (theta, z) r to the -1/2 power + D sub o (theta, phi) R to the lambda rho power. The first term is the cylindrical singularity with the power -1/2 and is dominant over the middle 96 pct (for Poisson's ratio = 0.3) of the crack front and becomes nearly zero at the free surface. The second singularity is a vertex singularity with the vertex point located at the intersection of the crack front and the free surface. The second term is dominant at the free surface and becomes nearly zero away from the the boundary layer. The thickness of the boundary layer depends on Poisson's ratio of the material and is independent of the specimen type. The thickness of the boundary layer varied from 0 pct to about 5 pct of the total specimen thickness as Poisson's ratio varied from 0.0 to 0.45. Because there are two singular stress fields near the free surface, the strain energy release rate (G) is an appropriate parameter to measure the severity of the crack

Implementation of equivalent domain integral method in the two-dimensional analysis of mixed mode problems

An equivalent domain integral (EDI) method for calculating J-intergrals for two-dimensional cracked elastic bodies is presented. The details of the method and its implementation are presented for isoparametric elements. The total and product integrals consist of the sum of an area of domain integral and line integrals on the crack faces. The line integrals vanish only when the crack faces are traction free and the loading is either pure mode 1 or pure mode 2 or a combination of both with only the square-root singular term in the stress field. The EDI method gave accurate values of the J-integrals for two mode I and two mixed mode problems. Numerical studies showed that domains consisting of one layer of elements are sufficient to obtain accurate J-integral values. Two procedures for separating the individual modes from the domain integrals are presented. The procedure that uses the symmetric and antisymmetric components of the stress and displacement fields to calculate the individual modes gave accurate values of the integrals for all problems analyzed. The EDI method when applied to a problem of an interface crack in two different materials showed that the mode 1 and mode 2 components are domain dependent while the total integral is not. This behavior is caused by the presence of the oscillatory part of the singularity in bimaterial crack problems. The EDI method, thus, shows behavior similar to the virtual crack closure method for bimaterial problems

A Note on 1-Edge Balance Index Set

A graph labeling is an assignment of integers to the vertices or edges or both, subject to certain conditions. Varieties of graph labeling have been investigated by many authors [2], [3] [5] and they serve as useful models for broad range of applications

Olfactory Neuroblastoma: Diagnostic Difficulty

Olfactory neuroblastoma is an uncommon malignant tumor of sinonasal tract arising from the olfactory neuro epithelium. The olfactory neuroblastomas presenting with divergent histomorphologies like, epithelial appearance of cells, lacking a neuro fibrillary background and absence of rosettes are difficult to diagnose. Such cases require immunohistochemistry to establish the diagnosis. We describe the clinical features, pathological and immunohistochemical findings of grade IV Olfactory neuroblastoma in a 57 year old ma

Multiple Choriangiomas of Placenta

Placental chorangiomas, not an uncommon condition is often small and hence usually goes unnoticed . However the incidence of complications is high when the chorangioma is large. We hereby present an unusual case of large and multiple choriangiomas with secondary changes and associated congenital anomalies with hydrops fetalis

A Single Day of 5-Azacytidine Exposure during Development Induces Neurodegeneration in Neonatal Mice and Neurobehavioral Deficits in Adult Mice

The present study was undertaken to evaluate the immediate and long-term effects of a single-day exposure to 5-Azacytidine (5-AzaC), a DNA methyltransferase inhibitor, on neurobehavioral abnormalities in mice. Our findings suggest that the 5-AzaC treatment significantly inhibited DNA methylation, impaired extracellular signal-regulated kinase (ERK1/2) activation and reduced expression of the activity-regulated cytoskeleton-associated protein (Arc). These events lead to the activation of caspase-3 (a marker for neurodegeneration) in several brain regions, including the hippocampus and cortex, two brain areas that are essential for memory formation and memory storage, respectively. 5-AzaC treatment of P7 mice induced significant deficits in spatial memory, social recognition, and object memory in adult mice and deficits in long-term potentiation (LTP) in adult hippocampal slices. Together, these data demonstrate that the inhibition of DNA methylation by 5-AzaC treatment in P7 mice causes neurodegeneration and impairs ERK1/2 activation and Arc protein expression in neonatal mice and induces behavioral abnormalities in adult mice. DNA methylation-mediated mechanisms appear to be necessary for the proper maturation of synaptic circuits during development, and disruption of this process by 5-AzaC could lead to abnormal cognitive function

Bioadhesive Controlled Release Clotrimazole Vaginal Tablets

Purpose: To formulate bioadhesive clotrimazole vaginal tablets using natural polymers in order to provide long-term therapeutic action at the site of infection. Methods: The tablets were prepared by direct compression using bioadhesive polymer mixtures: hydroxypropyl methylcellulose/sodium carboxymethylcellulose (HPMC/NaCMC) and HPMC/Guar gum (GG) in different ratios. Differential scanning calorimetry (DSC) and Fourier transform infrared (FT-IR) spectroscopic evaluations were carried out to assess compatibility between the drug and the excipients. The tablets were subjected to various pre- and post-compression evaluations, including in vitro drug release, in vitro bioadhesive strength, swelling and stability studies. Results: The results show that all the formulations satisfied Indian Pharmacopoeial specifications for tablet parameters. DSC and FT-IR data indicate there was no interaction between the drug and the excipients. Drug dissolution rate at pH 6.0 followed the rank order: HPMC)/NaCMC > HPMC/GG. There was increase in swelling index with time at 37 0C. The combination of HPMC with NaCMC showed greater mucoadhesive strength and superior controlled drug release to the formulations prepared with GG polymer mixture. Furthermore, the release properties of the former in pH 6.0 buffer, as well as release mechanism (n values), were negligibly affected by ageing. Conclusion: This study indicates the possible use of suitable mixtures of natural and semi-syntheticcellulosic polymers for the preparation of clotrimazole mucoadhesive tablets for application as a vaginal controlled delivery system.Keywords:  Clotrimazole, Swelling, Cellulosic polymers, Guar gum, Bioadhesion, Release propertie