Cochlear implant: indications, contraindications and complications

Cochlear implant (CI) is a surgically implanted electronic device that provides a sense of sound to a person who is profoundly deaf. CI represents the current treatment for patients affected by profound sensorineu- ral hearing loss (SNHL). At first times, only deaf adults were considered to be candidates for a CI; however, with the development of technology and gained experience by pshycians, indications for cochlear implan- tation have been expanded. Today, CIs are implanted also in children and broader indications are followed. There are, however, a number of patients who are potential candidates for CI but do not completely fulfill the current indications. Residual hearing and duration of deafness represent prognostic indicators for CI per- formance; however, prelingually deafened adults and children with residual hearing are still point at issue. Anatomical variations such as cochlear malformation, ossification and chronic otitis media still represent a contraindication to CI for some surgeons. Although the technology for cochlear implant surgery is advanc- ing everyday, there may be several complications related to the device or operation and some of them can be healed only with medical therapy but some are serious enough to process to reimplantation. In this arti- cle the indications and contraindications for cochlear implant candidates and complications that may occur during or after the operation were reviewed under the light of the literature

Recent graft materials in experimental study stage used in the treatment of nasal septum perforation: a review

Various conservative approaches are being used for the treatment of nasal septum perforations (NSPs); however, for permanent results, it is essential to use surgical methods. For this purpose, many various surgical methods have been tried, but a satisfactory method has not yet been determined. In order to eliminate the commonly encountered failure of surgical methods, new graft materials combined with flaps have been tried recently and successful results have been reported.In this review, we examined the scientific literature using Medline, PubMed, and Google by using the keywords "nasal septum perforation", "animal study", and "graft". According to the results obtained, we compiled graft materials that have been used in experimental stage related to this subject and reported to have achieved successful results, especially when combined with flaps. These materials seem promising for the successful closure of the hard-to-treat NSPs

Mechanical behavior of tissue simulants and soft tissues under extreme loading conditions

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 2013.Cataloged from PDF version of thesis.Includes bibliographical references (p. 157-168).Recent developments in computer-integrated surgery and in tissue-engineered constructs necessitate advances in experimental and analytical techniques in characterizing properties of mechanically compliant materials such as gels and soft tissues, particularly for small sample volumes. One goal of such developments is to quantitatively predict and mimic tissue deformation due to high rate impact events typical of industrial accidents and ballistic insults. This aim requires advances in mechanical characterization to establish tools and design principles for tissue simulant materials that can recapitulate the mechanical responses of hydrated soft tissues under dynamic contact-loading conditions. Given this motivation, this thesis studies the mechanical properties of compliant synthetic materials developed for tissue scaffold applications and of soft tissues, via modifying an established contact based technique for accurate, small scale characterization under fully hydrated conditions, and addresses some of the challenges in the implementation of this method. Two different engineered material systems composed of physically associating block copolymer gels, and chemically crosslinked networks including a solvent are presented as potential tissue simulants for ballistic applications, and compared directly to soft tissues from murine heart and liver. In addition to conventional quasistatic and dynamic bulk mechanical techniques that study macroscale elastic and viscoelastic properties, new methodologies are developed to study the small scale mechanical response of the aforementioned material systems to concentrated impact loading. The resistance to penetration and the energy dissipative constants are quantified in order to compare the deformation of soft tissues and mechanically optimized simulants, and to identify the underlying mechanisms by which the mechanical response of these tissue simulant candidates are modulated. Finally, given that soft tissues are biphasic in nature, atomic force microscopy enabled load relaxation experiments are utilized to develop approaches to distinguish between poroelastic and viscoelastic regimes, and to study how the anisotropy of the tissue structure affects elastic and transport properties, in order to inform the future design of tissue simulant gels that would mimic soft tissue response.by Zeynep Ilke Kalcioglu.Ph.D

A troublesome lesion of the larynx: Lobular capillary hemangioma

Lobular capillary hemangioma (LCH), which is also known as pyojenic granuloma, is a benign and vascular lesion of the skin and mucous membranes and mostly seen in females between 20-40 years of age. Although the etiology of the condition is still unknown, some conditions, such as trauma, poor oral hygiene, viral or fungal infections, and periodontal and gingival diseases are considered to be related to the formation of LCH. It mostly seems in cheek and oral cavity in head and neck region. Larynx localization of LCH is very rare. We present a case of LCH in a 47-year-old male and review the literature

Marrow-Derived Stem Cell Motility in 3D Synthetic Scaffold Is Governed by Geometry Along With Adhesivity and Stiffness

Author Manuscript 2012 May 21.Design of 3D scaffolds that can facilitate proper survival, proliferation, and differentiation of progenitor cells is a challenge for clinical applications involving large connective tissue defects. Cell migration within such scaffolds is a critical process governing tissue integration. Here, we examine effects of scaffold pore diameter, in concert with matrix stiffness and adhesivity, as independently tunable parameters that govern marrow-derived stem cell motility. We adopted an “inverse opal” processing technique to create synthetic scaffolds by crosslinking poly(ethylene glycol) at different densities (controlling matrix elastic moduli or stiffness) and small doses of a heterobifunctional monomer (controlling matrix adhesivity) around templating beads of different radii. As pore diameter was varied from 7 to 17 µm (i.e., from significantly smaller than the spherical cell diameter to approximately cell diameter), it displayed a profound effect on migration of these stem cells—including the degree to which motility was sensitive to changes in matrix stiffness and adhesivity. Surprisingly, the highest probability for substantive cell movement through pores was observed for an intermediate pore diameter, rather than the largest pore diameter, which exceeded cell diameter. The relationships between migration speed, displacement, and total path length were found to depend strongly on pore diameter. We attribute this dependence to convolution of pore diameter and void chamber diameter, yielding different geometric environments experienced by the cells within. Bioeng. 2011; 108:1181–1193(National Institute of General Medical Sciences (U.S.) (NRSA Fellowship GM083472)National Institutes of Health (U.S.) (National Institute of General Medical Sciences (U.S.) Cell Migration Consortium Grant GM064346)National Science Foundation (U.S.) (CAREER CBET-0644846

Concurrent Assay for Four Bacterial Species Including Alloiococcus Otitidis in Middle Ear, Nasopharynx and Tonsils of Children with Otitis Media with Effusion: A Preliminary Report

ObjectivesTo detect the prevalences of Alloiococcus otitidis, as well as Haemophilus influenzae, Streptococcus pneumoniae, and Moraxella catarrhalis in children with chronic otitis media with effusion (OME) and to simultaneously investigate the colonization of these bacteria in the nasopharynx and palatine tonsils of these patients.MethodsThe study included 34 pediatric patients with OME, and 15 controls without OME. In the study group, A. otitidis, H. influenzae, S. pneumoniae, and M. catarrhalis were investigated in the samples obtained from middle ear effusions (MEE), nasopharyngeal swabs (NPS) and tonsillar swabs (TS), using multiplex polymerase chain reaction (PCR) and conventional culture methods. Only the samples obtained from NPS and TS were studied with the same techniques in the control group.ResultsA. otitidis was isolated only in MEE and only with multiplex PCR method. A. otitidis, S. pneumoniae, M. catarrhalis, H. influenzae were identified in 35%, 8.8%, 8.8%, and 2.9%, respectively, in 34 MEE. A. otitidis was not isolated in NPS or TS of the study and the control groups.ConclusionThe prevalence of A.otitidis is high in children with OME and A.otitidis doesn't colonize in the nasopharynx or tonsil

Case Report Papillary Thyroid Microcarcinoma with a Large Cystic Dilated Lymph Node Metastasis to the Neck Mimicking a Branchial Cleft Cyst: A Potential Pitfall

Lateral cervical cystic mass in a young adult very rarely could be a first sign of an occult thyroid papillary microcarcinoma metastasis. In this paper, we presented a 37-year-old male patient whose preoperative 6 cm left lateral cervical cystic mass was initially diagnosed as branchial cleft cyst, but then the postoperative histopathological examination of the mass was revealed as papillary thyroid carcinoma metastasis. Preoperative fine needle aspiration biopsy was relevant with a branchial cleft cyst. In the left thyroid lobe there were 3 solid nodules with 4, 6, and 12 mm dimensions, respectively. One of the nodules had malignant well-differentiated cells diagnosed after fine needle aspiration biopsy. After total thyroidectomy, histopathologic evaluation of biopsy material's showed papillary thyroid microcarcinomas. This case indicates that especially in a young adult lateral cervical cystic mass should be carefully considered preoperatively for the possibility of metastatic occult thyroid carcinoma, especially for papillary carcinoma in differential diagnosis, and evaluation of the thyroid gland should be taken into account

Combinatorial Development of Biomaterials for Clonal Growth of Human Pluripotent Stem Cells

July 3, 2012Both human embryonic stem cells and induced pluripotent stem cells can self-renew indefinitely in culture; however, present methods to clonally grow them are inefficient and poorly defined for genetic manipulation and therapeutic purposes. Here we develop the first chemically defined, xeno-free, feeder-free synthetic substrates to support robust self-renewal of fully dissociated human embryonic stem and induced pluripotent stem cells. Material properties including wettability, surface topography, surface chemistry and indentation elastic modulus of all polymeric substrates were quantified using high-throughput methods to develop structure–function relationships between material properties and biological performance. These analyses show that optimal human embryonic stem cell substrates are generated from monomers with high acrylate content, have a moderate wettability and employ integrin α[subscript v]β[subscript 3] and α[subscript v]β[subscript 5] engagement with adsorbed vitronectin to promote colony formation. The structure–function methodology employed herein provides a general framework for the combinatorial development of synthetic substrates for stem cell culture.National Institutes of Health (U.S.) (Grant R37-CA084198)National Institutes of Health (U.S.) (Grant RO1-CA087869)National Institutes of Health (U.S.) (Grant RO1-HD045022)National Institutes of Health (U.S.) (Grant DE016516)Massachusetts Institute of Technology. Institute for Soldier Nanotechnologies (Contract W911NF-07-D-0004

Comparing the use of meat and clay during cutting and projectile research

Diverse disciplines investigate how muscular tissue (i.e. ‘meat’) responds to being cut and deformed, however, large-scale, empirically robust investigations into these matters are often impractical and expensive. Previous research has used clay as an alternative to meat. To establish whether clay is a reliable proxy for meat, we directly compare the two materials via a series of cutting and projectile tests. Results confirm that the two materials display distinct cutting mechanics, resistance to penetration and are not comparable. Under certain conditions clay can be used as an alternative to meat, although distinctions between the two may lead to experimental limitations