Disintegration of porous polyethylene prostheses.

PubMed

Kerr, A G; Riley, D N

1999-06-01

A Plastipore (porous polyethylene) Total Ossicular Replacement Prosthesis gave an excellent initial hearing result which was maintained for 14 years. Hearing then began to deteriorate and revision surgery showed disintegration of the prosthesis and a defect in the stapes footplate. Histological examination confirmed previous findings in porous polyethylene with multinucleated foreign body giant cells and breakdown of the material.

Model-oriented review and multi-body simulation of the ossicular chain of the human middle ear.

PubMed

Volandri, G; Di Puccio, F; Forte, P; Manetti, S

2012-11-01

The ossicular chain of the human middle ear has a key role in sound conduction since it transfers vibrations from the tympanic membrane to the cochlea, connecting the outer and the inner part of the hearing organ. This study reports firstly a description of the main anatomical features of the middle ear to introduce a detailed survey of its biomechanics, focused on model development, with a collection of geometric, inertial and mechanical/material parameters. The joint issues are particularly discussed from the perspective of developing a model of the middle ear both explanatory and predictive. Such a survey underlines the remarkable dispersion of data, due also to the lack of a standardization of the experimental techniques and conditions. Subsequently, a 3D multi-body model of the ossicular chain and other structures of the middle ear is described. Such an approach is justified as the ossicles were proven to behave as rigid bodies in the human hearing range and was preferred to the more widely used finite element one as it simplifies the model development and improves joint modeling. The displacement of the umbo (a reference point of the tympanic membrane) in the 0.3-6kHz frequency range was defined as input of the model, while the stapes footplate displacement as output. A parameter identification procedure was used to find parameter values for reproducing experimental and numerical reference curves taken from the literature. This simple model might represent a valid alternative to more complex models and might provide a useful tool to simulate pathological/post-surgical/post-traumatic conditions and evaluate ossicular replacement prostheses. Copyright © 2012 IPEM. Published by Elsevier Ltd. All rights reserved.

In vitro magnetic resonance imaging evaluation of ossicular implants at 3 T.

PubMed

Shellock, Frank G; Meepos, Lauren N; Stapleton, Matthew R; Valencerina, Sam

2012-07-01

Ossicular implants made from metallic materials may be acceptable or pose hazards for patients referred for magnetic resonance imaging (MRI) examinations, depending on the outcome of proper MRI testing procedures. Using a 3-T MR system, 2 ossicular implants were tested for magnetic field interactions, heating, and artifacts. Two different ossicular implants (Stainless Steel/Fluoroplastic Sanna-Type Piston [6 mm in length] and the Offset ALTO Total Prosthesis [15 mm in length, titanium/silicone]; Grace Medical, Memphis, TN, USA) were selected for testing, which represented the largest metallic mass and materials with the highest magnetic susceptibilities, with the intent of applying the MRI findings to other ossicular implants. The implants were evaluated at 3-T for magnetic field interactions, heating, and artifacts using standard previously described techniques. Each ossicular implant showed relatively minor magnetic field interactions that will not be associated with movement in situ. Heating was not excessive (highest temperature change, ≤ 1.6°C; background temperature change, 1.5°C). Artifacts, although relatively small, may create issues for diagnostic imaging if the area of interest is in the same area or close to these ossicular implants. The results of this investigation demonstrated that it would be acceptable (i.e., "MR conditional" using current terminology) for patients with these ossicular implants to undergo MRI examinations at 3 T or less. In consideration of the materials and dimensions of the implants that underwent testing, these findings pertain to many other similar ossicular implants from the same manufacturer.

Congenital Stapes Ankylosis in Children: Surgical Findings and Results in 35 Cases.

PubMed

Vincent, Robert; Wegner, Inge; Kamalski, Digna M A; Bittermann, Arnold J N; Grolman, Wilko

2016-04-01

To evaluate surgical findings and hearing results in children undergoing middle ear surgery for congenital stapes ankylosis with or without other ossicular malformations (Teunissen and Cremers class I and class II malformations). A nonrandomized, nonblinded case series of prospectively collected data. A tertiary referral center. Twenty-eight consecutive pediatric patients who underwent 35 surgical procedures for congenital stapes ankylosis with or without other ossicular malformations and had available postoperative pure-tone audiometry. Primary stapedotomy with vein graft interposition and reconstruction with a Teflon piston, bucket handle prosthesis or total ossicular replacement prosthesis. Pre- and postoperative audiometric evaluation using four-frequency (0.5, 1, 2, and 4 kHz) audiometry. Air-conduction thresholds, bone-conduction thresholds, and air-bone gaps (ABGs) were measured. Postoperative audiometry was performed at 3, 6, 9, 12, 18, and 24 months after surgery and at a yearly interval thereafter. Overall, a postoperative ABG closure of 10 dB or less was achieved in 73% of class I cases and in 50% of class II cases. A postoperative ABG closure of 20 dB or less was achieved in 77% of class I cases and 67% of class II cases. Postoperative sensorineural hearing loss occurred in one class I case (4%) and none of the class II cases. Stapedotomy is a safe and feasible treatment option in children with congenital stapes ankylosis.

Malleus-to-footplate prosthetic interposition: experience with 265 patients.

PubMed

Colletti, V; Fiorino, F G

1999-03-01

Absence of the long process of the incus with or without absence of the stapes head accounts for more than 80% of ossicular discontinuities. Total or partial replacement prostheses, made of various materials, are interposed to restore the transfer function of the middle ear. To simplify ossicular reconstruction, reduce operative times and costs, improve functional outcomes, and avoid the risk of infections, we have adopted, during the past 10 years, a technique that makes use of a personally designed alloplastic prosthetic device. The prosthesis connects the malleus to the footplate, even in the presence of the stapes superstructure. This malleus-to-footplate prosthesis consists in a plastipore-coated steel piston and hydroxyapatite head, complete with a groove. The groove is placed beneath the malleus neck after dissection of the tensor tympani tendon and the shaft of the piston on the footplate. Two hundred ninety primary ossiculoplasties with the malleus-to-footplate prostheses were performed in 265 patients from 1986 to 1995 in the ENT Department of the University of Verona. The average postoperative air-bone gap at 0.5 to 3 kHz was 11 dB at 1 year and 14 dB at 5 years. These outcomes are significantly better than those personally obtained previously with ossicular or alloplastic prostheses. No extrusions occurred. The structural characteristics of the malleus-to-foot-plate prosthesis endow the prosthesis with a high degree of biocompatibility and stability and optimal sound-transfer function. The rationale for this particular ossiculoplasty procedure is discussed.

Time Average Holography Study of Human Tympanic Membrane with Altered Middle Ear Ossicular Chain

NASA Astrophysics Data System (ADS)

Cheng, Jeffrey T.; Ravicz, Michael E.; Rosowski, John J.; Hulli, Nesim; Hernandez-Montes, Maria S.; Furlong, Cosme

2009-02-01

Computer-assisted time average holographic interferometry was used to study the vibration of the human tympanic membrane (TM) in cadaveric temporal bones before and after alterations of the ossicular chain. Simultaneous laser Doppler vibrometer measurements of stapes velocity were performed to estimate the conductive hearing loss caused by ossicular alterations. The quantified TM motion described from holographic images was correlated with stapes velocity to define relations between TM motion and stapes velocity in various ossicular disorders. The results suggest that motions of the TM are relatively uncoupled from stapes motion at frequencies above 1000 Hz.

Comparative study of new autologous material, bone-cartilage composite graft, for ossiculoplasty with Polycel® and Titanium.

PubMed

Kong, J S; Jeong, C Y; Shim, M J; Kim, W J; Yeo, S W; Park, S N

2018-04-01

Ossiculoplasty is a surgical procedure that recreates sound transmission of the middle ear in conductive hearing loss. Various materials have been used for ossicular reconstruction, but the most ideal material for ossiculoplasty remains controversial. The purpose of this study was to introduce a novel method of autologous ossiculoplasty, bone-cartilage composite graft (BCCG) and to compare its surgical results with different types of ossiculoplastic prostheses. A retrospective study was performed in a tertiary referral centre. Data of 275 patients who received ossiculoplasty using the three different materials of BCCG, Polycel ® and titanium were analysed according to type of ossiculoplasty: partial or total ossicular replacement prosthesis (PORP or TORP). Hearing results, complication rates and clinical parameters including age, sex, past history, preoperative diagnosis and surgery type were compared among different groups. Ossiculoplasty with BCCG showed satisfactory hearing outcomes and the lowest complication rate among the three different materials. In particular, its extrusion rate was 0%. We propose that the BCCG technique is a useful alternative method for ossiculoplasty, with proper patient selection. © 2017 John Wiley & Sons Ltd.

Numerical analysis of ossicular chain lesion of human ear

NASA Astrophysics Data System (ADS)

Liu, Yingxi; Li, Sheng; Sun, Xiuzhen

2009-04-01

Lesion of ossicular chain is a common ear disease impairing the sense of hearing. A comprehensive numerical model of human ear can provide better understanding of sound transmission. In this study, we propose a three-dimensional finite element model of human ear that incorporates the canal, tympanic membrane, ossicular bones, middle ear suspensory ligaments/muscles, middle ear cavity and inner ear fluid. Numerical analysis is conducted and employed to predict the effects of middle ear cavity, malleus handle defect, hypoplasia of the long process of incus, and stapedial crus defect on sound transmission. The present finite element model is shown to be reasonable in predicting the ossicular mechanics of human ear.

Flexibility in the mouse middle ear: A finite element study of the frequency response

NASA Astrophysics Data System (ADS)

Gottlieb, Peter; Puria, Sunil

2018-05-01

The mammalian middle ear is comprised of three distinct ossicles, connected by joints, and suspended in an air-filled cavity. In most mammals, the ossicular joints are mobile synovial joints, which introduce flexibility into the ossicular chain. In some smaller rodents, however, these joints are less mobile, and in the mouse in particular, the malleus is additionally characterized by a large, thin plate known as the transversal lamina, which connects the manubrium to the incus-malleus joint (IMJ). We hypothesize that this feature acts as a functional joint, maintaining the benefits of a flexible ossicular chain despite a less-mobile IMJ, and tested this hypothesis with a finite element model of the mouse middle ear. The results showed that while fusing the ossicular joints had a negligible effect on sound transmission, stiffening the ossicular bone significantly reduced sound transmission, implying that bone flexibility plays a critical role in the normal function of the mouse middle ear.

Sequential motion of the ossicular chain measured by laser Doppler vibrometry.

PubMed

Kunimoto, Yasuomi; Hasegawa, Kensaku; Arii, Shiro; Kataoka, Hideyuki; Yazama, Hiroaki; Kuya, Junko; Fujiwara, Kazunori; Takeuchi, Hiromi

2017-12-01

In order to help a surgeon make the best decision, a more objective method of measuring ossicular motion is required. A laser Doppler vibrometer was mounted on a surgical microscope. To measure ossicular chain vibrations, eight patients with cochlear implants were investigated. To assess the motions of the ossicular chain, velocities at five points were measured with tonal stimuli of 1 and 3 kHz, which yielded reproducible results. The sequential amplitude change at each point was calculated with phase shifting from the tonal stimulus. Motion of the ossicular chain was visualized from the averaged results using the graphics application. The head of the malleus and the body of the incus showed synchronized movement as one unit. In contrast, the stapes (incudostapedial joint and posterior crus) moved synchronously in opposite phase to the malleus and incus. The amplitudes at 1 kHz were almost twice those at 3 kHz. Our results show that the malleus and incus unit and the stapes move with a phase difference.

Systematic Review of Ossicular Chain Anatomy: Strategic Planning for Development of Novel Middle Ear Prostheses.

PubMed

Kamrava, Brandon; Roehm, Pamela C

2017-08-01

Objective To systematically review the anatomy of the ossicular chain. Data Sources Google Scholar, PubMed, and otologic textbooks. Review Methods A systematic literature search was performed on January 26, 2015. Search terms used to discover articles consisted of combinations of 2 keywords. One keyword from both groups was used: [ ossicular, ossicle, malleus, incus, stapes] and [ morphology, morphometric, anatomy, variation, physiology], yielding more than 50,000 hits. Articles were then screened by title and abstract if they did not contain information relevant to human ossicular chain anatomy. In addition to this search, references of selected articles were studied as well as suggested relevant articles from publication databases. Standard otologic textbooks were screened using the search criteria. Results Thirty-three sources were selected for use in this review. From these studies, data on the composition, physiology, morphology, and morphometrics were acquired. In addition, any correlations or lack of correlations between features of the ossicular chain and other features of the ossicular chain or patient were noted, with bilateral symmetry between ossicles being the only important correlation reported. Conclusion There was significant variation in all dimensions of each ossicle between individuals, given that degree of variation, custom fitting, or custom manufacturing of prostheses for each patient could optimize prosthesis fit. From published data, an accurate 3-dimensional model of the malleus, incus, and stapes can be created, which can then be further modified for each patient's individual anatomy.

Laser Doppler Vibrometry measurements of human cadaveric tympanic membrane vibration

PubMed Central

2013-01-01

Objective To determine the feasibility of measuring tympanic membrane (TM) vibrations at multiple locations on the TM to differentiate normal eardrums from those with associated ossicular pathologies. Design Cadaveric human temporal bone study. Setting Basic science laboratory. Methods A mastoidectomy and facial recess approach was performed on four cadaveric temporal bones to obtain access to the ossicles without disrupting the TM. Ossicles were palpated to ensure normal mobility and an intact ossicular chain. Laser Doppler Vibrometry (LDV) measurements were then taken on all four TMs. LDV measurements were repeated on each TM following stapes footplate fixation, incudo-stapedial joint dislocation, and malleus head fixation. Main outcome measures LDV measurements of TM vibration at the umbo, the lateral process of the malleus, and in each of the four quadrants of the TM. Results The best signal-to-noise ratios were found between 2 and 4 kHz, at the umbo, the anterior superior quadrant, the anterior inferior quadrant, and the posterior inferior quadrant. Since our goal was to assess the ossicular chain, we selected the TM locations closest to the ossicular chain (the umbo and lateral process of the malleus) for further analysis. Differences could be seen between normals and the simulated ossicular pathologies, but values were not statistically significant. Conclusions LDV measurements are technically challenging and require optimization to obtain consistent measurements. This study demonstrates the potential of LDV to differentiate ossicular pathologies behind an intact tympanic membrane. Future studies will further characterize the clinical role of this diagnostic modality. PMID:23663748

Human ossicular-joint flexibility transforms the peak amplitude and width of impulsive acoustic stimulia)

PubMed Central

Gottlieb, Peter K.; Vaisbuch, Yona

2018-01-01

The role of the ossicular joints in the mammalian middle ear is still debated. This work tests the hypothesis that the two synovial joints filter potentially damaging impulsive stimuli by transforming both the peak amplitude and width of these impulses before they reach the cochlea. The three-dimensional (3D) velocity along the ossicular chain in unaltered cadaveric human temporal bones (N = 9), stimulated with acoustic impulses, is measured in the time domain using a Polytec (Waldbronn, Germany) CLV-3D laser Doppler vibrometer. The measurements are repeated after fusing one or both of the ossicular joints with dental cement. Sound transmission is characterized by measuring the amplitude, width, and delay of the impulsive velocity profile as it travels from the eardrum to the cochlea. On average, fusing both ossicular joints causes the stapes velocity amplitude and width to change by a factor of 1.77 (p = 0.0057) and 0.78 (p = 0.011), respectively. Fusing just the incudomalleolar joint has a larger effect on amplitude (a factor of 2.37), while fusing just the incudostapedial joint decreases the stapes velocity on average. The 3D motion of the ossicles is altered by fusing the joints. Finally, the ability of current computational models to predict this behavior is also evaluated.

Design and experimental analysis of a new malleovestibulopexy prosthesis using a finite element model of the human middle ear.

PubMed

Vallejo Valdezate, Luis A; Hidalgo Otamendi, Antonio; Hernández, Alberto; Lobo, Fernando; Gil-Carcedo Sañudo, Elisa; Gil-Carcedo García, Luis M

2015-01-01

Many designs of prostheses are available for middle ear surgery. In this study we propose a design for a new prosthesis, which optimises mechanical performance in the human middle ear and improves some deficiencies in the prostheses currently available. Our objective was to design and assess the theoretical acoustic-mechanical behaviour of this new total ossicular replacement prosthesis. The design of this new prosthesis was based on an animal model (an iguana). For the modelling and mechanical analysis of the new prosthesis, we used a dynamic 3D computer model of the human middle ear, based on the finite elements method (FEM). The new malleovestibulopexy prosthesis design demonstrates an acoustical-mechanical performance similar to that of the healthy human middle ear. This new design also has additional advantages, such as ease of implantation and stability in the middle ear. This study shows that computer simulation can be used to design and optimise the vibroacoustic characteristics of middle ear implants and demonstrates the effectiveness of a new malleovestibulopexy prosthesis in reconstructing the ossicular chain. Copyright © 2014 Elsevier España, S.L.U. y Sociedad Española de Otorrinolaringología y Patología Cérvico-Facial. All rights reserved.

Surgical Management and Hearing Outcome of Traumatic Ossicular Injuries.

PubMed

Delrue, Stefan; Verhaert, Nicolas; Dinther, Joost van; Zarowski, Andrzej; Somers, Thomas; Desloovere, Christian; Offeciers, Erwin

2016-12-01

The purpose of this study was to investigate etiological, clinical, and pathological characteristics of traumatic injuries of the middle ear ossicular chain and to evaluate hearing outcome after surgery. Thirty consecutive patients (31 ears) with traumatic ossicular injuries operated on between 2004 and 2015 in two tertiary referral otologic centers were retrospectively analyzed. Traumatic events, clinical features, ossicular lesions, treatment procedures, and audiometric results were evaluated. Air conduction (AC), bone conduction (BC), and air-bone gap (ABG) were analyzed preoperatively and postoperatively. Amsterdam Hearing Evaluation Plots (AHEPs) were used to visualize the individual hearing results. The mean age at the moment of trauma was 27.9±17.1 years (range, 2-75 years) and the mean age at surgery was 33.2±16.3 years (range, 5-75 years). In 10 cases (32.3%), the injury occurred by a fall on the head and in 9 (29.0%) by a traffic accident. Isolated luxation of the incus was observed in 8 cases (25.8%). Dislocation of the stapes footplate was seen in 4 cases (12.9%). The postoperative ABG closure to within 10 and 20 dB was 30% and 76.7%, respectively. Ossicular chain injury by direct or indirect trauma can provoke hearing loss, tinnitus, and vertigo. As injuries are heterogeneous, they require a tailored surgical approach. In this study, the overall hearing outcome after surgical repair was favorable.

Fascin expression in cholesteatoma: correlation with destruction of the ossicular chain and extent of disease.

PubMed

Binnetoglu, A; Sari, M; Baglam, T; Erbarut Seven, I; Yumusakhuylu, A C; Topuz, M F; Batman, C

2015-08-01

Fascin is an actin-bundling protein found in cell membrane protrusions and increases cell motility. The expression of fascin in epithelial neoplasms has been described only recently. No data are available concerning the role of this protein in invasive cholesteatoma. Thus, we investigated the expression of fascin in cholesteatoma tissue and the relationship between fascin expression and intraoperative evaluation of the destruction of the ossicular chain and extent of disease. Cholesteatoma specimens of 28 patients and external auditory canal (EAC) skin specimens of the same patients (as the control group) were collected from mastoidectomies. Immunohistochemical technique was used to investigate the fascin expression in all cholesteatoma tissues and EAC skin specimens. Immunohistochemical staining was assessed semiquantitatively based on the thickness of epithelium. SPSS software version 16.0 (SPSS Inc., Chicago, IL, USA) was performed to statistically analyse the relationships between fascin expression and intraoperative evaluation destruction of ossicular chain and extent of the disease. Immunohistochemically, there was no or very low fascin expression observed in normal epithelial cells of EAC skin, while expressed in cholesteatoma tissue. Also, fascin expression in cholesteatoma tissues was significantly correlated with destruction of ossicular chain and extent of the disease. Fascin expression is usually found in cholesteatoma epithelium and is correlated with destruction of the ossicular chain and extent of disease. Considering all of the correlations between the clinical and histopathological findings, 'fascin immunoexpression scoring' may be used for histological grading of cholesteatoma. © 2015 John Wiley & Sons Ltd.

A new tool for testing ossicular mobility during middle ear surgery: preliminary report of four cases.

PubMed

Hato, Naohito; Kohno, Hisashi; Okada, Masahiro; Hakuba, Nobuhiro; Gyo, Kiyofumi; Iwakura, Takashi; Tateno, Makoto

2006-08-01

We developed an ossicular vibration tester for the objective and quantitative assessment of ossicular mobility, which is one of the most critical factors affecting postoperative hearing after tympanoplasty. Our device consists of three components: a probe shaft with a curved tip to be attached to the target ossicle, a vibration exciter to activate the probe, and a piezoelectric sensor to detect vibrations of the probe. These components are encased in a stainless steel holder, allowing easy hand manipulation during ear surgery. The probe is activated with an electric signal at around 1,600 Hz. The system is controlled with a laptop computer, and the results are presented as the ratio of the ossicular resistance (ROR) to a reference value as a percentage. One measurement takes 10 ms. The device was applied in four selected patients during ear surgery. Several measurements in two of the cochlear implantees showed a greater difference in the RORs of the stapes (15-20% in Case 1 and 35-45% in Case 2), whereas the RORs of the malleus and incus were within the same range. This was thought to correspond to the partial cochlear calcification noted in Case 2. In Case 3, who underwent surgery because of otosclerosis, the ROR of the stapes was high, ranging from 70 to 80%. When measured for the malleus-incus fixation anomaly (Case 4), the ROR of the malleus and incus was in the range of 60 to 70%. Owing to the limited surgical view, the ROR of the stapes could not be measured. No problems related to the measurements with this device were noted. The design, principles, measuring procedures, and preliminary results of our new tool for testing ossicular mobility are reported. Measuring the ossicular mobility during surgery may provide important information for deciding the surgical procedures.

Anatomical measurement of the ossicles in patients with congenital aural atresia and stenosis.

PubMed

Li, Jieying; Chen, Keguang; Li, Chenlong; Yin, Dongming; Zhang, Tianyu; Dai, Peidong

2017-10-01

Our aims were to measure and compare anatomical parameters of the ossicles in normal, congenital aural stenosis (CAS), and congenital aural atresia (CAA) ears. This retrospective study was performed using three-dimensional reconstructed images derived from computed tomography scans of 20 normal subjects, 20 CAS patients, and 20 CAA patients. The lengths of the malleus handle and long process of the incus were greater in normal ears than in CAS and CAA ears (all P < 0.05). The angles of the incudostapedial joint and between the short and long processes of the incus were smaller in normal ears than in CAS and CAA ears (all P < 0.05). There were no significant differences in the positions of the malleus head and incudomalleolar joint, the size of the malleus head, the length of the short process of the incus, or the angle of the incudomalleolar joint (P > 0.05). Anatomical parameters of the lower part, but not of the upper part, of the ossicular chain in CAS and CAA ears differed from those in normal ears. Different branchial arch origins of the upper and lower parts of the ossicular chain may explain these findings. Dysplasia of the second arch, which develops into the lower part of the ossicular chain, may contribute to ossicular malformation in CAA and CAS. Accurate radiographic measurement of malformed ossicles may be useful for reconstructive surgery of CAA and CAS using the patient's native ossicular chain and for choosing an appropriate place for active middle ear implants. Copyright © 2017. Published by Elsevier B.V.

Clinical assessment of ossicular mobility by a ceramic vibrator designed for implantable hearing aids.

PubMed

Gyo, K; Yanagihara, N

1986-01-01

Ossicular mobility was assessed by direct coupling of a piezoelectric ceramic vibrator to the ossicles during middle ear surgery. The sites excited were body of the incus, head of the stapes, and footplate of the stapes through a hydroxyapatite ceramic strut. The threshold of the vibratory hearing was determined by the patient's response as a minimum audition, and the vibration threshold was obtained by subtracting the preoperative bone conduction threshold from the vibratory hearing threshold. The results were analyzed by the state of hearing after the operation, which revealed that a patient with a good vibration threshold during the operation had a tendency to get good postoperative hearing. This may mean that postoperative hearing can be predicted to some extent during the operation by the measurement of ossicular mobility.

Non-ossicular signal transmission in human middle ears: Experimental assessment of the “acoustic route” with perforated tympanic membranes

PubMed Central

Voss, Susan E.; Rosowski, John J.; Merchant, Saumil N.; Peake, William T.

2008-01-01

Direct acoustic stimulation of the cochlea by the sound-pressure difference between the oval and round windows (called the “acoustic route”) has been thought to contribute to hearing in some pathological conditions, along with the normally dominant “ossicular route.” To determine the efficacy of this acoustic route and its constituent mechanisms in human ears, sound pressures were measured at three locations in cadaveric temporal bones [with intact and perforated tympanic membranes (TMs)]: (1) in the external ear canal lateral to the TM, PTM; (2) in the tympanic cavity lateral to the oval window, POW; and (3) near the round window, PRW. Sound transmission via the acoustic route is described by two concatenated processes: (1) coupling of sound pressure from ear canal to middle-ear cavity, HPCAV≡PCAV/PTM, where PCAV represents the middle-ear cavity pressure, and (2) sound-pressure difference between the windows, HWPD≡(POW−PRW)/PCAV. Results show that: HPCAV depends on perforation size but not perforation location; HWPD depends on neither perforation size nor location. The results (1) provide a description of the window pressures based on measurements, (2) refute the common otological view that TM perforation location affects the “relative phase of the pressures at the oval and round windows,” and (3) show with an intact ossicular chain that acoustic-route transmission is substantially below ossicular-route transmission except for low frequencies with large perforations. Thus, hearing loss from TM perforations results primarily from reduction in sound coupling via the ossicular route. Some features of the frequency dependence of HPCAV and HWPD can be interpreted in terms of a structure-based lumped-element acoustic model of the perforation and middle-ear cavities. PMID:17902851

Postinflammatory ossicular fixation: CT analysis with surgical correlation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Swartz, J.D.; Wolfson, R.J.; Marlowe, F.I.

1985-03-01

Postinflammatory ossicular fixation is a common problem encountered by the otologic surgeon upon exploration because of conductive hearing loss in patients with chronic otitis media. These nonotosclerotic noncongenital lesions take three pathologic forms: fibrous tissue fixation (chronic adhesive otitis media), hyalinization of collagen (tympanosclerosis), and new bone formation (fibro-osseous sclerosis). More than 300 patients with the clinical diagnosis of chronic otitis media have been examined. This study encompasses 23 proved cases.

Differential Intracochlear Sound Pressure Measurements in Normal Human Temporal Bones

NASA Astrophysics Data System (ADS)

Nakajima, Hideko Heidi; Dong, Wei; Olson, Elizabeth S.; Merchant, Saumil N.; Ravicz, Michael E.; Rosowski, John J.

2009-02-01

We present the first simultaneous sound pressure measurements in scala vestibuli and scala tympani of the cochlea in human cadaveric temporal bones. Micro-scale fiberoptic pressure sensors enabled the study of differential sound pressure at the cochlear base. This differential pressure is the input to the cochlear partition, driving cochlear waves and auditory transduction. Results showed that: pressure of scala vestibuli was much greater than scala tympani except at low and high frequencies where scala tympani pressure affects the input to the cochlea; the differential pressure proved to be an excellent measure of normal ossicular transduction of sound (shown to decrease 30-50 dB with ossicular disarticulation, whereas the individual scala pressures were significantly affected by non-ossicular conduction of sound at high frequencies); the middle-ear gain and differential pressure were generally bandpass in frequency dependence; and the middle-ear delay in the human was over twice that of the gerbil. Concurrent stapes velocity measurements allowed determination of the differential impedance across the partition and round-window impedance. The differential impedance was generally resistive, while the round-window impedance was consistent with a compliance in conjunction with distributed inertia and damping. Our techniques can be used to study inner-ear conductive pathologies (e.g., semicircular dehiscence), as well as non-ossicular cochlear stimulation (e.g., round-window stimulation) - situations that cannot be completely quantified by measurements of stapes velocity or scala-vestibuli pressure by themselves.

Middle ear dynamics in response to seismic stimuli in the Cape golden mole (Chrysochloris asiatica).

PubMed

Willi, U B; Bronner, G N; Narins, P M

2006-01-01

The hypertrophied malleus in the middle ear of some golden moles has been assumed to be an adaptation for sensing substrate vibrations by inertial bone conduction, but this has never been conclusively demonstrated. The Cape golden mole (Chrysochloris asiatica) exhibits this anatomical specialization, and the dynamic properties of its middle ear response to vibrations were the subjects of this study. Detailed three-dimensional middle ear anatomy was obtained by x-ray microcomputed tomography (muCT) at a resolution of 12 microm. The ossicular chain exhibits large malleus mass, selective reduction of stiffness and displacement of the center of mass from the suspension points, all favoring low-frequency tuning of the middle ear response. Orientation of the stapes relative to the ossicular chain and the structure of the stapes footplate enable transmission of substrate vibrations arriving from multiple directions to the inner ear. With the long axes of the mallei aligned parallel to the surface, the animal's head was stimulated by a vibration exciter in the vertical and lateral directions over a frequency range from 10 to 600 Hz. The ossicular chain was shown to respond to both vertical and lateral vibrations. Resonant frequencies were found between 71 and 200 Hz and did not differ significantly between the two stimulation directions. Below resonance, the ossicular chain moves in phase with the skull. Near resonance and above, the malleus moves at a significantly larger mean amplitude (5.8+/-2.8 dB) in response to lateral vs vertical stimuli and is 180 degrees out of phase with the skull in both cases. A concise summary of the propagation characteristics of both seismic body (P-waves) and surface (R-waves) is provided. Potential mechanisms by which the animal might exploit the differential response of the ossicular chain to vertical and lateral excitation are discussed in relation to the properties of surface seismic waves.

[Equivalent Lever Principle of Ossicular Chain and Amplitude Reduction Effect of Internal Ear Lymph].

PubMed

Zhao, Xiaoyan; Qin, Renjia

2015-04-01

This paper makes persuasive demonstrations on some problems about the human ear sound transmission principle in existing physiological textbooks and reference books, and puts forward the authors' view to make up for its literature. Exerting the knowledge of lever in physics and the acoustics theory, we come up with an equivalent simplified model of manubrium mallei which is to meet the requirements as the long arm of the lever. We also set up an equivalent simplified model of ossicular chain--a combination of levers of ossicular chain. We disassemble the model into two simple levers, and make full analysis and demonstration on them. Through the calculation and comparison of displacement amplitudes in both external auditory canal air and internal ear lymph, we may draw a conclusion that the key reason, which the sound displacement amplitude is to be decreased to adapt to the endurance limit of the basement membrane, is that the density and sound speed in lymph is much higher than those in the air.

Tympanic plate fractures in temporal bone trauma: prevalence and associated injuries.

PubMed

Wood, C P; Hunt, C H; Bergen, D C; Carlson, M L; Diehn, F E; Schwartz, K M; McKenzie, G A; Morreale, R F; Lane, J I

2014-01-01

The prevalence of tympanic plate fractures, which are associated with an increased risk of external auditory canal stenosis following temporal bone trauma, is unknown. A review of posttraumatic high-resolution CT temporal bone examinations was performed to determine the prevalence of tympanic plate fractures and to identify any associated temporal bone injuries. A retrospective review was performed to evaluate patients with head trauma who underwent emergent high-resolution CT examinations of the temporal bone from July 2006 to March 2012. Fractures were identified and assessed for orientation; involvement of the tympanic plate, scutum, bony labyrinth, facial nerve canal, and temporomandibular joint; and ossicular chain disruption. Thirty-nine patients (41.3 ± 17.2 years of age) had a total of 46 temporal bone fractures (7 bilateral). Tympanic plate fractures were identified in 27 (58.7%) of these 46 fractures. Ossicular disruption occurred in 17 (37.0%). Fractures involving the scutum occurred in 25 (54.4%). None of the 46 fractured temporal bones had a mandibular condyle dislocation or fracture. Of the 27 cases of tympanic plate fractures, 14 (51.8%) had ossicular disruption (P = .016) and 18 (66.6%) had a fracture of the scutum (P = .044). Temporomandibular joint gas was seen in 15 (33%) but was not statistically associated with tympanic plate fracture (P = .21). Tympanic plate fractures are commonly seen on high-resolution CT performed for evaluation of temporal bone trauma. It is important to recognize these fractures to avoid the preventable complication of external auditory canal stenosis and the potential for conductive hearing loss due to a fracture involving the scutum or ossicular chain.

Feasible pickup from intact ossicular chain with floating piezoelectric microphone.

PubMed

Kang, Hou-Yong; Na, Gao; Chi, Fang-Lu; Jin, Kai; Pan, Tie-Zheng; Gao, Zhen

2012-02-22

Many microphones have been developed to meet with the implantable requirement of totally implantable cochlear implant (TICI). However, a biocompatible one without destroying the intactness of the ossicular chain still remains under investigation. Such an implantable floating piezoelectric microphone (FPM) has been manufactured and shows an efficient electroacoustic performance in vitro test at our lab. We examined whether it pick up sensitively from the intact ossicular chain and postulated whether it be an optimal implantable one. Animal controlled experiment: five adult cats (eight ears) were sacrificed as the model to test the electroacoustic performance of the FPM. Three groups were studied: (1) the experiment group (on malleus): the FPM glued onto the handle of the malleus of the intact ossicular chains; (2) negative control group (in vivo): the FPM only hung into the tympanic cavity; (3) positive control group (Hy-M30): a HiFi commercial microphone placed close to the site of the experiment ear. The testing speaker played pure tones orderly ranged from 0.25 to 8.0 kHz. The FPM inside the ear and the HiFi microphone simultaneously picked up acoustic vibration which recorded as .wav files to analyze. The FPM transformed acoustic vibration sensitively and flatly as did the in vitro test across the frequencies above 2.0 kHz, whereas inefficiently below 1.0 kHz for its overloading mass. Although the HiFi microphone presented more efficiently than the FPM did, there was no significant difference at 3.0 kHz and 8.0 kHz. It is feasible to develop such an implantable FPM for future TICIs and TIHAs system on condition that the improvement of Micro Electromechanical System and piezoelectric ceramic material technology would be applied to reduce its weight and minimize its size.

Audiometric evaluation of an attempt to optimize the fixation of the transducer of a middle-ear implant to the ossicular chain with bone cement.

PubMed

Snik, A; Cremers, C

2004-02-01

Typically, an implantable hearing device consists of a transducer that is coupled to the ossicular chain and electronics. The coupling is of major importance. The Vibrant Soundbridge (VSB) is such an implantable device; normally, the VSB transducer is fixed to the ossicular chain by means of a special clip that is crimped around the long process of the incus. In addition to crimping, bone cement was used to optimize the fixation in six patients. Long-term results were compared to those of five controls with crimp fixation alone. To assess the effect of bone cement (SerenoCem, Corinthian Medical Ltd, Nottingham, UK) on hearing thresholds, long-term post-surgery thresholds were compared to pre-surgery thresholds. Bone cement did not have any negative effect. Next, to test the hypothesis that aided thresholds might be better with the use of bone cement, aided thresholds were studied. After correction for the severity of hearing loss, only a small difference was found between the two groups at one frequency, viz. 2 kHz. It was concluded that there was no negative effect of using bone cement; however, there is also no reason to use bone cement in VSB users on a regular basis.

A New Intraoperative Real-time Monitoring System for Reconstructive Middle Ear Surgery: An Experimental and Clinical Feasibility Study.

PubMed

Zahnert, Thomas; Metasch, Marie-Luise; Seidler, Hannes; Bornitz, Matthias; Lasurashvili, Nicoloz; Neudert, Marcus

2016-12-01

Electromagnetical excitation of ossicular vibration is suitable for middle ear transmission measurements in the experimental and clinical setting. Thereby, it can be used as a real-time monitoring system for quality control in ossiculoplasty. Positioning and coupling of middle ear prosthesis are a precondition for good postoperative hearing results, but at the same time completely dependent upon the surgeon's subjective judgment during surgery. We evaluated an electromagnetically driven measurement system that enables for in vitro and in vivo transmission measurements and thus can be used as a real-time monitoring tool in ossicular reconstruction. For electromagnetical excitation a magnet was placed on the umbo of the malleus handle and driven by a magnetic field. The induced stapes displacement was picked up by laser Doppler vibrometry on the footplate. Measurements were performed on the intact ossicular chain in five cadaveric temporal bones and during five cochlear implant surgeries. Additionally, two ossiculoplasties were performed under real-time transmission feedback with the monitoring system. Experimentally, the equivalent sound pressure level of the electromagnetic excitation was about 70 to 80 dB which is 10 to 20 dB less than the acoustic stimulation. In the intraoperative setup the generated stapes displacements were about 5 to 20 dB smaller compared with the temporal bone experiments. Applied as real-time feedback system, an improvement in the middle ear transfer function of 4.5 dB in total and 20 dB in partial ossicular reconstruction were achieved. The electromagnetical excitation and measurement system is comparable to the gold standard with acoustical stimulation in both, the experimental setup in temporal bones as well as in vivo. The technical feasibility of the electromagnetical excitation method has been proven and it is shown that it can be used as a real-time monitoring system for ossiculoplasty in the operation room.

Reassessment of the La Ferrassie 3 Neandertal ossicular chain.

PubMed

Quam, Rolf; Martínez, Ignacio; Arsuaga, Juan Luis

2013-04-01

The ossicular chain in La Ferrassie 3 was briefly described in the monograph on the La Ferrassie Neandertal children, but to date has not been the subject of detailed study. We provide new data on these important fossils and re-examine some previous suggestions of derived Neandertal features in the middle ear ossicles based on more limited evidence. The malleus shows a curved lateral margin of the manubrium and a relatively large head. The incus shows a tall articular facet, a depressed area on the medial surface of the body, a straight anterior border of the long process and a more closed angle between the processes. The stapes shows an asymmetrical configuration of the crura, with an anteriorly skewed head, and generally small dimensions, including a smaller and relatively wider stapedial footplate. These same features can also be seen in the few other Neandertal ear ossicles known, suggesting that a consistent anatomical pattern characterizes the Neandertal ossicular chain. While the phylogenetic polarity of many of these features remains to be clarified, the asymmetrical stapes and anteriorly skewed stapedial head appear to be derived Neandertal features. In addition, while the larger malleus head and incus articular facet in La Ferrassie 3 might reflect larger body mass in Neandertals, the larger stapes footplates in Homo sapiens cannot be explained by changes in body mass. Indeed, H. sapiens seems to depart from the general mammalian pattern in combining an increase in stapes footplate size with a decrease in body mass. Although the malleus/incus lever ratio in La Ferrassie 3 is similar to that in H. sapiens, Neandertals appear to be characterized by a slightly different spatial relationship and articulation of the ossicular chain within the tympanic cavity. While only limited inferences can be drawn regarding hearing ability based on the ossicles, the few physiologically relevant dimensions in the La Ferrassie 3 ear bones are similar to H. sapiens. Copyright © 2013 Elsevier Ltd. All rights reserved.

High frequency bone conduction auditory evoked potentials in the guinea pig: Assessing cochlear injury after ossicular chain manipulation.

PubMed

Bergin, M J; Bird, P A; Vlajkovic, S M; Thorne, P R

2015-12-01

Permanent high frequency (>4 kHz) sensorineural hearing loss following middle ear surgery occurs in up to 25% of patients. The aetiology of this loss is poorly understood and may involve transmission of supra-physiological forces down the ossicular chain to the cochlea. Investigating the mechanisms of this injury using animal models is challenging, as evaluating cochlear function with evoked potentials is confounded when ossicular manipulation disrupts the normal air conduction (AC) pathway. Bone conduction (BC) using clinical bone vibrators in small animals is limited by poor transducer output at high frequencies sensitive to trauma. The objectives of the present study were firstly to evaluate a novel high frequency bone conduction transducer with evoked auditory potentials in a guinea pig model, and secondly to use this model to investigate the impact of middle ear surgical manipulation on cochlear function. We modified a magnetostrictive device as a high frequency BC transducer and evaluated its performance by comparison with a calibrated AC transducer at frequencies up to 32 kHz using the auditory brainstem response (ABR), compound action potential (CAP) and summating potential (SP). To mimic a middle ear traumatising stimulus, a rotating bur was brought in to contact with the incudomalleal complex and the effect on evoked cochlear potentials was observed. BC-evoked potentials followed the same input-output function pattern as AC potentials for all ABR frequencies. Deterioration in CAP and SP thresholds was observed after ossicular manipulation. It is possible to use high frequency BC to evoke responses from the injury sensitive basal region of the cochlea and so not rely on AC with the potential confounder of conductive hearing loss. Ongoing research explores how these findings evolve over time, and ways in which injury may be reduced and the cochlea protected during middle ear surgery. Copyright © 2015 Elsevier B.V. All rights reserved.

Ossicular fusion and cholesteatoma in auriculo-condylar syndrome: in vivo evidence of arrest of embryogenesis.

PubMed

Propst, Evan J; Ngan, Bo Y; Mount, Richard J; Martin-Munoz, Daniel; Blaser, Susan; Harrison, Robert V; Cushing, Sharon L; Papsin, Blake C

2013-02-01

Auriculo-condylar syndrome (ACS) is a rare condition affecting first branchial arch structures. The types of hearing loss and temporal bone findings in ACS have not been reported. We describe a 14-year-old male with constricted pinnae, mandibular dysostosis, glossoptosis, a high-arched palate, hearing loss, and cholesteatoma. Computed tomography imaging demonstrated malleoincudal joint ankylosis. The fused malleoincudal complex was removed during mastoidectomy for cholesteatoma. Electron microscopy and histopathology of the joint suggested the fusion was congenital. This is the first report of ossicular fusion and cholesteatoma in ACS and the most detailed in vivo evidence of disruption of embryogenesis during malleoincudal joint formation. Copyright © 2012 The American Laryngological, Rhinological, and Otological Society, Inc.

Direct Age Determination of a Subtropical Freshwater Crayfish (Redclaw, Cherax quadricarinatus) Using Ossicular Growth Marks

PubMed Central

Leland, Jesse C.; Bucher, Daniel J.; Coughran, Jason

2015-01-01

Recent studies have reported that crustacean age determination is possible. We applied a direct ageing method (i.e. transverse cross sectioning of gastric ossicles) to a subtropical freshwater crayfish (Cherax quadricarinatus) sourced from an aquaculture population. Growth mark periodicity and the potential for chronological depositions were investigated by staining C. quadricarinatus with calcein and examining their ossicles a year later. Pterocardiac ossicles were superior to other ageing structures (i.e. other ossicles and eyestalks) and produced repeatable between-reader counts (87% were corroborated and 13% varied by ±1). C. quadricarinatus size-at-age data (for an aquaculture population) was described by a von Bertalanffy growth equation (L ∞ = 32 mm occipital carapace length; K = 0.64; t 0 = –0.18; R2 = 0.81). Ossicular growth marks did not correspond to moult history. The calcein stain was retained over an annual cycle comprising multiple moults, demonstrating that pterocardiac ossicles retain chronological information. The maximum age (3+) corroborated other indirectly-obtained longevity estimates for C. quadricarinatus. Multiple lines of evidence indicate that the growth marks in C. quadricarinatus ossicles are probably deposited annually during winter. The ability to extract age information from subtropical decapods provides substantial opportunities for advancing fisheries and conservation research globally, but further research is needed to provide a definitive validation and elucidate the mechanism governing the accrual of ossicular growth marks. PMID:26309228

Laser vibrometer measurements and middle ear prostheses

NASA Astrophysics Data System (ADS)

Flock, Stephen T.; Dornhoffer, John; Ferguson, Scott

1997-05-01

One of us has developed an improved partial ossicular replacement prosthesis that is easier to implant and, based on pilot clinical measurements, results in better high-frequency hearing as compared to patients receiving one of the alternative prostheses. It is hypothesized that the primary reason for this is because of the relatively light weight (about 25 mg) and low compliance of the prosthesis, which could conceivably result in better high frequency vibrational characteristics. The purpose of our initial work was to develop an instrument suitable for objectively testing the vibrational characteristics of prostheses. We have developed a laser based device suitable for measuring the vibrational characteristics of the oval window or other structures of the middle ear. We have tested this device using a piezoelectric transducer excited at audio frequencies, as well as on the oval window in human temporal bones harvested from cadavers. The results illustrate that it is possible to non-invasively monitor the vibrational characteristics of anatomic structures with a very inexpensive photonic device.

Investigation of a broadband duct noise control system inspired by the middle ear mechanism

NASA Astrophysics Data System (ADS)

Wang, Chunqi; Huang, Lixi

2012-08-01

A new duct noise control device is introduced based on the mechanism of human middle ear which functions as a compact, broadband impedance transformer between the air motion in the outer ear and the liquid motion in the inner ear. The system consists of two rigid endplates, simulating the tympanic membrane and the stapes footplate, and they are connected by a single rigid rod, simulating the overall action of the ossicular chain. These three pieces are placed in a side-branch cavity, and the whole device is called an ossicular silencer. A specific configuration is investigated numerically with a two-dimensional finite element model. Results show that broadband noise attenuation can be achieved in the very low frequency regime. Typically, two or more resonance peaks are found and the transmission loss between two neighbouring peaks is maintained at a high level. The cavity length is found to be the most crucial parameter that determines the effective frequency range of the ossicular silencer. The total cavity volume, which is a major controlling factor in most existing noise control devices, becomes less influential. The fluid medium in the enclosed cavity mainly acts like an added mass, while its stiffness effect is negligible. Simplified plane wave analysis is also conducted to reveal the mechanisms of the system resonances. The first resonance is identified as of the mass-spring system with mass contributions from both fluid and the plates, while the second one is of the Herschel-Quincke (HQ) tube resonance.

Cholesteatomas of the temporal bone: role of computed tomography

DOE Office of Scientific and Technical Information (OSTI.GOV)

Johnson, D.W.; Voorhees, R.L.; Lufkin, R.B.

1983-09-01

Computed tomography (CT) of the temporal bone was performed in 64 patients thought to have a cholesteatoma of the middle ear. Twenty had not had surgery before, while 44 had been operated on; special consideration was given to 21 patients who were scanned immediately before a second operation and had confirmation of the CT findings. Inflammatory disease without cholesteatoma was characterized by absence of erosion of the otic capsule or ossicular chain. Sharply circumscribed cholesteatomas were easily diagnosed by CT. When they were combined with scarring, granulation tissue, or postsurgical changes, the resulting soft-tissue masses were indistinguishable, although cholesteatoma maymore » be suspected if there is evidence of progressive bone erosion about the middle ear. CT can play a major role in postoperative follow-up by confirming that the ear is normal and demonstrating displacement of ossicular grafts or prostheses.« less

The Tympanic Membrane Motion in Forward and Reverse Middle-Ear Sound Transmission

NASA Astrophysics Data System (ADS)

Cheng, Jeffrey Tao; Harrington, Ellery; Horwitz, Rachelle; Furlong, Cosme; Rosowski, John J.

2011-11-01

Sound-induced displacement of the tympanic membrane (TM) is the first stage in the forward transformation of environmental sound to sound within the inner ear, while displacement of the TM induced by mechanical motions of the ossicular chain is the last stage in the reverse transformation of sound generated within the inner ear to clinically valuable otoacoustic emissions (OAEs). In this study, we use stroboscopic holographic interferometry to study motions of the human cadaveric TM evoked by both forward and reverse stimuli. During forward acoustic stimulation, pure tones from 500 to 10000 Hz are used to stimulate the TM, while reverse stimulation is produced by direct mechanical stimulation of the ossicular chain. The TM surface motions in response to both forward and reverse stimuli show differences and similarities, including the modal motion patterns at specific frequencies as well as the presence and directions of traveling waves on the TM surface.

Mass distribution and rotational inertia of "microtype" and "freely mobile" middle ear ossicles in rodents.

PubMed

Lavender, Danielle; Taraskin, Sergei N; Mason, Matthew J

2011-12-01

The middle ears of seven species of rodents, including four hamster species, were examined under light microscopy and through micro-CT imaging. Hamsters were found to possess a spectrum of ossicular morphologies ranging from something approaching "freely mobile" (Mesocricetus) to something nearer the "microtype" (Cricetulus), although no hamster has an orbicular apophysis of the malleus. Rats, mice and Calomyscus were found to have typically microtype ossicles. To explore the functional effects of these morphological differences, CT scan data were used to calculate the magnitudes of the moments of inertia and positions of the centres of mass and principal rotational axes for the malleus-incus complexes. Microtype species were found to have much greater ossicular inertias, relative to size, about the "anatomical axis" extending between anterior process of the malleus and short process of the incus; ossicular centres of mass were displaced further from this axis. Calculated inertial values were then put into an existing model of middle ear function (Hemilä et al., 1995), in order to see whether the more accurate data would improve predictions of upper hearing limits. For the rat and mouse they did, but this was not so for the hamster Mesocricetus. This might indicate that the inner rather than the middle ear limits hearing in this species, or might simply reflect other shortcomings of the model. Functional differences appear to exist even among rodent ears of the same general type, but the adaptive significance of these differences remains enigmatic. Copyright © 2011 Elsevier B.V. All rights reserved.

Zirconium: biomedical and nephrological applications.

PubMed

Lee, David B N; Roberts, Martin; Bluchel, Christian G; Odell, Ross A

2010-01-01

Recent years have witnessed a rapid increase in the use of zirconium (Zr)-containing compounds in artificial internal organs. Examples include dental implants and other restorative practices, total knee and hip replacement, and middle-ear ossicular chain reconstruction. In nephrological practice, Zr-containing sorbents have been used in hemofiltration, hemodialysis, peritoneal dialysis, and in the design and construction of wearable artificial kidneys. Zr compounds continue to be widely and extensively used in deodorant and antiperspirant preparations. In the public health arena, Zr compounds have been studied or used in controlling phosphorus pollution and in the reclamation of poison and bacteria-contaminated water. Experimental and clinical studies support the general consensus that Zr compounds are biocompatible and exhibit low toxicity. Reports on possible Zr-associated adverse reactions are rare and, in general, have not rigorously established a cause-and-effect relationship. Although publications on the use of Zr compounds have continued to increase in recent years, reports on Zr toxicity have virtually disappeared from the medical literature. Nevertheless, familiarity with, and continued vigilant monitoring of, the use of these compounds are warranted. This article provides an updated review on the biomedical use of Zr compounds.

Biomimicry at the nanoscale: current research and perspectives of two-photon polymerization.

PubMed

Marino, Attilio; Filippeschi, Carlo; Mattoli, Virgilio; Mazzolai, Barbara; Ciofani, Gianni

2015-02-21

Living systems such as cells and tissues are extremely sensitive to their surrounding physico-chemical microenvironment. In the field of regenerative medicine and tissue engineering, the maintenance of culture conditions suitable for the formation of proliferation niches, for the self-renewal maintenance of stem cells, or for the promotion of a particular differentiation fate is an important issue that has been addressed using different strategies. A number of investigations suggests that a particular cell behavior can be in vitro resembled by mimicking the corresponding in vivo conditions. In this context, several biomimetic environments have been designed in order to control cell phenotypes and functions. In this review, we will analyze the most recent examples of the control of the in vitro physical micro/nano-environment by exploiting an innovative technique of high resolution 3D photolithography, the two-photon polymerization (2pp). The biomedical applications of this versatile and disruptive computer assisted design/manufacturing technology are very wide, and range from the fabrication of biomimetic and nanostructured scaffolds for tissue engineering and regenerative medicine, to the microfabrication of biomedical devices, like ossicular replacement prosthesis and microneedles.

Biomimicry at the nanoscale: current research and perspectives of two-photon polymerization

NASA Astrophysics Data System (ADS)

Marino, Attilio; Filippeschi, Carlo; Mattoli, Virgilio; Mazzolai, Barbara; Ciofani, Gianni

2015-02-01

Living systems such as cells and tissues are extremely sensitive to their surrounding physico-chemical microenvironment. In the field of regenerative medicine and tissue engineering, the maintenance of culture conditions suitable for the formation of proliferation niches, for the self-renewal maintenance of stem cells, or for the promotion of a particular differentiation fate is an important issue that has been addressed using different strategies. A number of investigations suggests that a particular cell behavior can be in vitro resembled by mimicking the corresponding in vivo conditions. In this context, several biomimetic environments have been designed in order to control cell phenotypes and functions. In this review, we will analyze the most recent examples of the control of the in vitro physical micro/nano-environment by exploiting an innovative technique of high resolution 3D photolithography, the two-photon polymerization (2pp). The biomedical applications of this versatile and disruptive computer assisted design/manufacturing technology are very wide, and range from the fabrication of biomimetic and nanostructured scaffolds for tissue engineering and regenerative medicine, to the microfabrication of biomedical devices, like ossicular replacement prosthesis and microneedles.

Determinants of Change in Air-Bone Gap and Bone Conduction in Patients Operated on for Chronic Otitis Media.

PubMed

Wiatr, Maciej; Wiatr, Agnieszka; Składzień, Jacek; Stręk, Paweł

2015-08-11

Middle ear surgery aims to eliminate pathology from the middle ear, improve drainage and ventilation of the postoperative cavity, and reconstruct the tympanic membrane and ossicles. The aim of this work is to define the factors that affect ABG (air-bone gap) and bone conduction in the patients operated on due to chronic otitis media. A prospective analysis of patients operated on due to diseases of the middle ear during 2009-2012 was carried out. The cases of patients operated on for the first time due to chronic otitis media were analyzed. The analysis encompassed patients who had undergone middle ear surgery. The patients were divided into several groups taking into account the abnormalities of the middle ear mucous and damage of the ossicular chain observed during otosurgery. A significant hearing improvement was observed in patients with type 2 tympanoplasty in the course of chronic cholesteatoma otitis media and in patients with simple chronic inflammatory process in whom a PORP was used in the reconstruction. Granulation tissue was an unfavorable factor of hearing improvement following tympanoplasty. A significant improvement of bone conduction was observed in the patients with dry perforation without other lesions in the middle ear. The elimination of granulation lesions was a positive factor for the future improvement of the function of the inner ear. The presence of granuloma-related lesions in the middle ear spaces is likely to impede hearing improvement. Damage to the ossicular chain rules out the possibility of bone conduction improvement after surgery. The prognosis on tube-related simple chronic otitis media after myringoplasty, with the preserved continuity of the ossicular chain, consists of closing the ABG and leads to significant improvement of bone conduction.

Hearing and Mortality Outcomes following Temporal Bone Fractures.

PubMed

Honeybrook, Adam; Patki, Aniruddha; Chapurin, Nikita; Woodard, Charles

2017-12-01

The aim of this article is to determine hearing and mortality outcomes following temporal bone fractures. Retrospective chart review was performed of 152 patients diagnosed with a temporal bone fracture presenting to the emergency room at a tertiary care referral center over a 10-year period. Utilizing Patients' previously obtained temporal bone computed tomographic scans and audiograms, fractures were classified based on several classification schemes. Correlations between fracture patterns, mortality, and hearing outcomes were analyzed using χ 2 tests. Ossicular chain disruption was seen in 11.8% of patients, and otic capsule violation was seen in 5.9%; 22.7% of patients presented for audiologic follow-up. Seventeen patients with conductive hearing loss had air-bone gaps of 26 ± 7.5 dB (500 Hz), 27 ± 6.8 dB (1,000 Hz), 18 ± 6.2 dB (2,000 Hz), and 32 ± 7.7 dB (4,000 Hz). Two cases of profound sensorineural hearing loss were associated with otic capsule violation. No fracture classification scheme was predictive of hearing loss, although longitudinal fractures were statistically associated with ossicular chain disruption ( p  < 0.01). Temporal bone fractures in patients older than 60 years carried a relative risk of death of 3.15 compared with those younger than 60 years. The average magnitude of conductive hearing loss resulting from temporal bone fracture ranged from 18 to 32 dB in this cohort. Classification of fracture type was not predictive of hearing loss, despite the statistical association between ossicular chain disruption and longitudinal fractures. This finding may be due to the low follow-up rates of this patient population. Physicians should make a concerted effort to ensure that audiological monitoring is executed to prevent and manage long-term hearing impairment.

Mechanics and materials in middle ear reconstruction.

PubMed

Lesser, T H; Williams, K R; Blayney, A W

1991-02-01

The normal anatomy and physiology of the middle ear is not reproduced in ossiculoplasty and an artificial mechanism for the transmission of sound results. This is true for all types of graft, be they of natural or man-made material. There are, therefore, 2 areas for consideration when looking at the problems encountered in such reconstructions: first, the materials' biocompatability and, secondly, the mechanical effects of the positioning of the graft in the reconstructed ossicular chain. The present work examines these mechanical effects using the finite element method to determine stress and displacement levels in the reconstructed ossicular chain. It is found that the stress levels at the implant-stapedial joint increases as the implant is gradually moved down the malleus. In contrast there is thought to be an increase in sound transmission as the implant is moved down the malleus. Changes in rigidity and hardness of the implant appear to make only modest stress attenuations at the implant-stapes interface.

Intracochlear pressure measurements during acoustic shock wave exposure.

PubMed

Greene, Nathaniel T; Alhussaini, Mohamed A; Easter, James R; Argo, Theodore F; Walilko, Tim; Tollin, Daniel J

2018-05-19

Injuries to the peripheral auditory system are among the most common results of high intensity impulsive acoustic exposure. Prior studies of high intensity sound transmission by the ossicular chain have relied upon measurements in animal models, measurements at more moderate sound levels (i.e. < 130 dB SPL), and/or measured responses to steady-state noise. Here, we directly measure intracochlear pressure in human cadaveric temporal bones, with fiber optic pressure sensors placed in scala vestibuli (SV) and tympani (ST), during exposure to shock waves with peak positive pressures between ∼7 and 83 kPa. Eight full-cephalic human cadaver heads were exposed, face-on, to acoustic shock waves in a 45 cm diameter shock tube. Specimens were exposed to impulses with nominal peak overpressures of 7, 28, 55, & 83 kPa (171, 183, 189, & 192 dB pSPL), measured in the free field adjacent to the forehead. Specimens were prepared bilaterally by mastoidectomy and extended facial recess to expose the ossicular chain. Ear canal (EAC), middle ear, and intracochlear sound pressure levels were measured with fiber-optic pressure sensors. Surface-mounted sensors measured SPL and skull strain near the opening of each EAC and at the forehead. Measurements on the forehead showed incident peak pressures approximately twice that measured by adjacent free-field and EAC entrance sensors, as expected based on the sensor orientation (normal vs tangential to the shock wave propagation). At 7 kPa, EAC pressure showed gain, calculated from the frequency spectra, consistent with the ear canal resonance, and gain in the intracochlear pressures (normalized to the EAC pressure) were consistent with (though somewhat lower than) previously reported middle ear transfer functions. Responses to higher intensity impulses tended to show lower intracochlear gain relative to EAC, suggesting sound transmission efficiency along the ossicular chain is reduced at high intensities. Tympanic membrane (TM) rupture was observed following nearly every exposure 55 kPa or higher. Intracochlear pressures reveal lower middle-ear transfer function magnitudes (i.e. reduced gain relative to the ear canal) for high sound pressure levels, thus revealing lower than expected cochlear exposure based on extrapolation from cochlear pressures measured at more moderate sound levels. These results are consistent with lowered transmissivity of the ossicular chain at high intensities, and are consistent with our prior report measuring middle ear transfer functions in human cadaveric temporal bones with high intensity tone pips. Copyright © 2018 Elsevier B.V. All rights reserved.

Incus replacement prostheses of hydroxylapatite in middle ear reconstruction.

PubMed

Wehrs, R E

1989-05-01

Hydroxylapatite is a calcium bioceramic that has the same chemical composition as living bone, Ca10 (PO4) 6 (OH) 2. Since 1970 it has been used as a material in reconstructive prostheses and augmentation of lost tissues in various surgical specialties including maxillofacial surgery, plastic surgery, otolaryngology, and orthopedics. For over 20 years the author has used autograft and homograft ossicles in tympanoplasty. These incudi have been modified into prostheses that were utilized in ossicular reconstruction. During this time two principle prostheses have evolved, the notched incus with short and long processes. The short process prosthesis is used with an intact stapes, whereas the notched incus with long process carries the sound pressure directly to the stapedial footplate. These prostheses have been successful in improving and maintaining hearing following tympanoplasty. Unfortunately, however, the use of human tissue has certain limitations: it is not readily accessible and has a limited shelf life. Furthermore, clinicians are wary of using homograft tissue as concern over the AIDS virus spreads. Therefore it was felt prudent to develop a manmade prosthesis that would as nearly as possible match the advantages of living bone. Hydroxylapetite most nearly met those qualifications.

Electrocoagulation improving bone cement use in middle-ear surgery: short-term and middle-term results.

PubMed

Galy-Bernadoy, C; Akkari, M; Mondain, M; Uziel, A; Venail, F

2016-12-01

Bone cement is used for ossicular chain repair and revision stapes surgery. Its efficient use requires cautious removal of mucosa from the ossicles. This paper reports a technique for easy, fast and safe removal of this mucosa prior to cement application. It consists of the application of monopolar electrocoagulation on the ossicles prior to bone cement application. The outcomes of six cases of revision stapes surgery and seven cases of partial ossiculoplasty, conducted between 2007 and 2012 using this new technique, were evaluated. Intra-operative reports and audiometric data were collected. During the last assessment, reconstruction using bone cement resulted in mean post-operative air-bone gaps of 4.1 ± 6.5 dB in revision stapes surgery cases and 5.7 ± 5.5 dB in partial ossiculoplasty cases, reflecting a significant hearing improvement (p = 0.03). No complications were observed. Electrocoagulation allows the removal of mucosa from the ossicles in an easy, fast and safe manner, enabling the use of bone cement for ossicular chain reconstruction.

Comparison of Conventional Versus Spiral Computed Tomography with Three Dimensional Reconstruction in Chronic Otitis Media with Ossicular Chain Destruction.

PubMed

Naghibi, Saeed; Seifirad, Sirous; Adami Dehkordi, Mahboobeh; Einolghozati, Sasan; Ghaffarian Eidgahi Moghadam, Nafiseh; Akhavan Rezayat, Amir; Seifirad, Soroush

2016-01-01

Chronic otitis media (COM) can be treated with tympanoplasty with or without mastoidectomy. In patients who have undergone middle ear surgery, three-dimensional spiral computed tomography (CT) scan plays an important role in optimizing surgical planning. This study was performed to compare the findings of three-dimensional reconstructed spiral and conventional CT scan of ossicular chain study in patients with COM. Fifty patients enrolled in the study underwent plane and three dimensional CT scan (PHILIPS-MX 8000). Ossicles changes, mastoid cavity, tympanic cavity, and presence of cholesteatoma were evaluated. Results of the two methods were then compared and interpreted by a radiologist, recorded in questionnaires, and analyzed. Logistic regression test and Kappa coefficient of agreement were used for statistical analyses. Sixty two ears with COM were found in physical examination. A significant difference was observed between the findings of the two methods in ossicle erosion (11.3% in conventional CT vs. 37.1% in spiral CT, P = 0.0001), decrease of mastoid air cells (82.3% in conventional CT vs. 93.5% in spiral CT, P = 0.001), and tympanic cavity opacity (12.9% in conventional CT vs. 40.3% in spiral CT, P=0.0001). No significant difference was observed between the findings of the two methods in ossicle destruction (6.5% conventional CT vs. 56.4% in spiral CT, P = 0.125), and presence of cholesteatoma (3.2% in conventional CT vs. 42% in spiral CT, P = 0.172). In this study, spiral CT scan demonstrated ossicle dislocation in 9.6%, decrease of mastoid air cells in 4.8%, and decrease of volume in the tympanic cavity in 1.6%; whereas, none of these findings were reported in the patients' conventional CT scans. Spiral-CT scan is superior to conventional CT in the diagnosis of lesions in COM before operation. It can be used for detailed evaluation of ossicular chain in such patients.

Anatomical study of the pigs temporal bone by microdissection.

PubMed

Garcia, Leandro de Borborema; Andrade, José Santos Cruz de; Testa, José Ricardo Gurgel

2014-01-01

Initial study of the pig`s temporal bone anatomy in order to enable a new experimental model in ear surgery. Dissection of five temporal bones of Sus scrofa pigs obtained from UNIFESP - Surgical Skills Laboratory, removed with hole saw to avoid any injury and stored in formaldehyde 10% for better conservation. The microdissection in all five temporal bone had the following steps: inspection of the outer part, external canal and tympanic membrane microscopy, mastoidectomy, removal of external ear canal and tympanic membrane, inspection of ossicular chain and middle ear. Anatomically it is located at the same position than in humans. Some landmarks usually found in humans are missing. The tympanic membrane of the pig showed to be very similar to the human, separating the external and the middle ear. The middle ear`s appearance is very similar than in humans. The ossicular chain is almost exactly the same, as well as the facial nerve, showing the same relationship with the lateral semicircular canal. The temporal bone of the pigs can be used as an alternative for training in ear surgery, especially due the facility to find it and its similarity with temporal bone of the humans.

Sound transmission in archaic and modern whales: anatomical adaptations for underwater hearing.

PubMed

Nummela, Sirpa; Thewissen, J G M; Bajpai, Sunil; Hussain, Taseer; Kumar, Kishor

2007-06-01

The whale ear, initially designed for hearing in air, became adapted for hearing underwater in less than ten million years of evolution. This study describes the evolution of underwater hearing in cetaceans, focusing on changes in sound transmission mechanisms. Measurements were made on 60 fossils of whole or partial skulls, isolated tympanics, middle ear ossicles, and mandibles from all six archaeocete families. Fossil data were compared with data on two families of modern mysticete whales and nine families of modern odontocete cetaceans, as well as five families of noncetacean mammals. Results show that the outer ear pinna and external auditory meatus were functionally replaced by the mandible and the mandibular fat pad, which posteriorly contacts the tympanic plate, the lateral wall of the bulla. Changes in the ear include thickening of the tympanic bulla medially, isolation of the tympanoperiotic complex by means of air sinuses, functional replacement of the tympanic membrane by a bony plate, and changes in ossicle shapes and orientation. Pakicetids, the earliest archaeocetes, had a land mammal ear for hearing in air, and used bone conduction underwater, aided by the heavy tympanic bulla. Remingtonocetids and protocetids were the first to display a genuine underwater ear where sound reached the inner ear through the mandibular fat pad, the tympanic plate, and the middle ear ossicles. Basilosaurids and dorudontids showed further aquatic adaptations of the ossicular chain and the acoustic isolation of the ear complex from the skull. The land mammal ear and the generalized modern whale ear are evolutionarily stable configurations, two ends of a process where the cetacean mandible might have been a keystone character. 2007 Wiley-Liss, Inc.

Laser stepedotomy for otosclerosis.

PubMed

Perkins, R C

1980-02-01

The argon laser microscope recently developed by the author is used to vaporize the stapes tendon, the posterior crus and a rosette of holes in the stapes footplate in the surgical treatment of otosclerosis. An autogenous vein--stainless steel piston assembly is used to reconstruct the stapes portion of the ossicular chain. The surgical technique and results in a preliminary series of 11 patients are reported. Rationale and advantages over conventional stapedectomy are discussed.

In vitro Characteristics of a Glass Ionomer Cement.

PubMed

Driscoll, C L; Green, J D; Beatty, C W; McCaffrey, T V; Marrs, C D

1998-01-01

Glass ionomer cements were first described by Wilson and Kent and have been used in dentistry since 1969. It has been recommended for bridging ossicular chain defects, fixation of ossicular chain prosthesis, anchoring of cochlear implants, mastoid obliteration, and repair of tegmen and posterior canal wall defects. The biocompatability and stability of this material over time is vital to its usefulness in neurotologic surgery. The purpose of this study was to assess the stability of a glass ionomer cement in the presence of bacteria and in different pH environments. We demonstrated that bacteria readily adhere to the surface and their presence is associated with accelerated loss of matrix. We found the cement to be susceptible to low pH and to release a visible cloud of debris upon contact with fluid. Calcium concentration in the solution was elevated at all pH levels. Although we are able to demonstrate these findings in vitro the clinical relevance is unclear. There have been several cases of aseptic meningitis possibly due to intracranial release of components of the cement. Until further studies are done use of the cement in contact with cerebral spinal fluid should be avoided. This cement, or a similar material, would be useful in neurotologic surgery but prior to widespread use further testing should be done to assess safety.

Finite element analysis of auditory characteristics in patients with middle ear diseases.

PubMed

Tu, Bo; Li, Xiaoping; Nie, Zhenhua; Shi, Changzheng; Li, Hengguo

2017-07-01

This study validates that a finite element model of the human ossicular chain and tympanic membrane can be used as an effective surgical assessment tool in clinics. The present study was performed to investigate the application of a finite element model of ossicular chain and tympanic membrane for fabrication of individualized artificial ossicles. Twenty patients (20 ears) who underwent surgery for middle ear disease (n = 20) and 10 healthy controls (10 ears) were enrolled in the hospital. Computed tomography (CT) and pure tone audiometry were performed before and after surgery. A finite element model was developed using CT scans, and correlation analysis was conducted between stapes displacement and surgical methods. An audiometric test was also performed for 14 patients before and after surgery. Stapes displacement in the healthy group (average = 3.31 × 10 -5  mm) was significantly greater than that in the impaired group (average = 1.41 × 10 -6 mm) prior to surgery. After surgery, the average displacement in the impaired group was 2.55 × 10 -6 mm, which represented a significant improvement. For the patients who underwent the audiometric test, 10 improved hearing after surgery, and stapes displacement increased in nine of these 10 patients.

A dynamic and harmonic damped finite element analysis model of stapedotomy.

PubMed

Blayney, A W; Williams, K R; Rice, H J

1997-03-01

This study was undertaken in an attempt to better understand the mechanics of sound transmission at the footplate following stapedotomy. The insertion of a Teflon (polytetrafluoroethylene) stapes prosthesis introduces new constraints within the reconstructed ossicular chain which have an effect on the normal vibration patterns of the tympanic membrane. In a finite element model of the ear, constraints have been reproduced as a series of spring constants in the incus/prosthesis/footplate interfaces incorporating damping to simulate the impedance of the inner ear. At zero damping, the frequency response at the pseudo stapes footplate exhibit several maxima and minima between 800 Hz and 2.5 Hz. At higher damping values, these maxima and minima become smoothened out with two or three naturals occurring over the same frequency range. Severe ankylosis of a diseased footplate is reproduced by over-damped conditions. The umbo, incus and stapes footplate vibrate in phase with similar frequencies at light damping levels. The movement of the prosthesis at the pseudo-footplate can be large in the out of plane axis of the ossicular chain, unless sufficient support is provided at the reconstructed footplate. Clinically, this would suggest the vein graft interposed between the piston and stapedotomy hole should endow resistance and elasticity to the system.

Biomechanical Modeling and Measurement of Blast Injury and Hearing Protection Mechanisms

DTIC Science & Technology

2015-10-01

12 software into Workbench V. 15 in CFX/ANSYS; 2) building the geometry of the ear model with ossicular chain and cochlear load in CFX; 3...the ear canal to middle ear. The model consists of the ear canal, TM, middle ear ossicles and suspensory ligaments, middle ear cavity, and cochlear ...the TM, ossicles, and ligaments/muscle tendons with the cochlear load applied on the stapes footplate. 17 Fig. 21. Time-history plots of

In vitro Characteristics of a Glass Ionomer Cement

PubMed Central

Driscoll, Colin L. W.; Green, J. Douglas; Beatty, Charles W.; McCaffrey, Thomas V.; Marrs, Christopher D.

1998-01-01

Glass ionomer cements were first described by Wilson and Kent and have been used in dentistry since 1969. It has been recommended for bridging ossicular chain defects, fixation of ossicular chain prosthesis, anchoring of cochlear implants, mastoid obliteration, and repair of tegmen and posterior canal wall defects. The biocompatability and stability of this material over time is vital to its usefulness in neurotologic surgery. The purpose of this study was to assess the stability of a glass ionomer cement in the presence of bacteria and in different pH environments. We demonstrated that bacteria readily adhere to the surface and their presence is associated with accelerated loss of matrix. We found the cement to be susceptible to low pH and to release a visible cloud of debris upon contact with fluid. Calcium concentration in the solution was elevated at all pH levels. Although we are able to demonstrate these findings in vitro the clinical relevance is unclear. There have been several cases of aseptic meningitis possibly due to intracranial release of components of the cement. Until further studies are done use of the cement in contact with cerebral spinal fluid should be avoided. This cement, or a similar material, would be useful in neurotologic surgery but prior to widespread use further testing should be done to assess safety. ImagesFigure 1Figure 2Figure 3Figure 4Figure 5Figure 9Figure 10Figure 11 PMID:17171062

High-resolution computed tomography of the middle ear and mastoid. Part III. Surgically altered anatomy and pathology

DOE Office of Scientific and Technical Information (OSTI.GOV)

Swartz, J.D.; Goodman, R.S.; Russell, K.B.

1983-08-01

High-resolution computed tomography (CT) provides an excellent method for examination of the surgically altered middle ear and mastoid. Closed-cavity and open-cavity types of mastoidectomy are illustrated. Recurrent cholesteatoma in the mastoid bowl is easily diagnosed. Different types of tympanoplasty are discussed and illustrated, as are tympanostomy tubes and various ossicular reconstructive procedures. Baseline high-resolution CT of the postoperative middle ear and mastoid is recommended at approximately 3 months following the surgical procedure.

Endoscopic management of chronic otitis media and tympanoplasty.

PubMed

Tarabichi, Muaaz; Ayache, Stéphane; Nogueira, João Flávio; Al Qahtani, Munahi; Pothier, David D

2013-04-01

The endoscope allows for better inspection for cholesteatoma in cases with chronic otitis media, better access to selective epitympanic poor ventilation and secondary selective chronic otitis media, better visualization of anterior poor ventilation of the mesotympanum (reestablishing adequate ventilation to the mesotympanum), better visualization and reconstruction of anterior tympanic membrane perforations, allows use of Sheehy's lateral graft tympanoplasty through a transcanal approach, and increases the odds of preoperative detection of ossicular chain disruption associated with perforations. Copyright © 2013 Elsevier Inc. All rights reserved.

Microendoscopy of the eustachian tube and the middle ear

NASA Astrophysics Data System (ADS)

Hopf, Juergen U. G.; Linnarz, Marietta; Gundlach, Peter; Scherer, Hans H.; Lutze-Koffroth, C.; Loerke, S.; Voege, Karl H.; Tschepe, Johannes; Mueller, Gerhard J.

1992-08-01

Progressive miniaturization of flexible fiberoptic instruments has made it possible to perform atraumatic endoscopy of the Eustachian tube and tympanic cavity with an intact ear drum. By means of a special set of carrier- and balloon-catheters which are partly actively steerable, flexible microendoscopes with outside diameters of 290 - 700 micrometers are inserted through the nasal cavity into the nasopharyngeal opening of the Eustachian tube and carefully advanced into the middle ear compartment under permanent direct visual control. Second generation microendoscopes with outside diameters of 750 to 1000 micrometers are equipped with a one- direction tip-steering mechanism which allows deflection up to 90 degrees. In addition to it, the use of two special types of four-function scopes (outside diameter: 1.6 mm and 1.8 mm) fitted with a one-lumen working channel are presented. This new technique of `Transnasal Tubo-Tympanoscopy' (TTT) only needs local anesthesia, normally is performed on an outpatient basis, and is indicated for the diagnosis of any disturbances of the sound conducting apparatus (ear drum and ossicular chain) like chronic otitis media and oto-sclerosis and of those sensorineural hearing disorders on which -- until today -- only the traditional surgical tympanoscopy could provide morphological information on the pathogenesis of the hearing loss, e.g., on assumed round window ruptures. By this minimal invasive and minimal traumatizing method pathological alterations of the ossicular chain as well as obstructions in the cartilaginous and the osseous part of the Eustachian tube can be directly visualized.

A Comparison Study of Partial Ossicular Reconstruction Prosthesis (PORP) Placement under the Malleus or Tympanic Membrane Graft in the Presence of the Malleus.

PubMed

Mutlu, Ahmet; Topdağ, Özlem; Topdağ, Murat; İşeri, Mete; Erdoğan, Selvet

2017-08-01

The aim of this study was to compare the hearing results of embedding the partial ossicular reconstruction prosthesis (PORP) underneath the malleus with the malleus relocation technique and tympanic membrane graft in the presence of the malleus. A retrospective review of patient charts and audiometric results in a tertiary referral center was conducted. In total, 83 patients who underwent intact canal tympanoplasty with mastoidectomy between 2010 and 2015 were included and divided into two different groups: malleus assembly to the stapes head (MASH) and tympanic membrane assembly to the stapes head (TASH). Pre- and postoperative audiometric results were assessed. The air-bone gap (ABG) and hearing gains were evaluated according to the groups. In MASH, 86.1% (n=31) of the patients were received successful surgery and the postoperative average ABG was 10.41 dB. In TASH, 82.9% (n=39) of the patients were considered successful and the postoperative ABG was 13.27 dB. According to the overall data, MASH was more statistically successful than TASH, and hearing gains at 500 Hz (p<0.036), 2000 Hz (p<0.031), and PTA (p<0.22) were statistically significant better in the MASH group. Malleus relocation is a successful technique with the presence of the malleus and provides better hearing outcomes than direct placement under the tympanomeatal flap. Both malleus- and tympanomeatal flap-linked groups were successful, but the malleus-linked group showed better ABGs.

Endoscopic versus transcranial procurement of allograft tympano-ossicular systems: a prospective double-blind randomized controlled audit.

PubMed

Caremans, Jeroen; Hamans, Evert; Muylle, Ludo; Van de Heyning, Paul; Van Rompaey, Vincent

2016-06-01

Allograft tympano-ossicular systems (ATOS) have proven their use over many decades in tympanoplasty and reconstruction after resection of cholesteatoma. The transcranial bone plug technique has been used in the past 50 years to procure en bloc ATOS (tympanic membrane with malleus, incus and stapes attached). Recently, our group reported the feasibility of the endoscopic procurement technique. The aim of this study was to assess whether clinical outcome is equivalent in ATOS acquired by using the endoscopic procurement technique compared to ATOS acquired by using the transcranial technique. A double-blind randomized controlled audit was performed in a tertiary referral center in patients that underwent allograft tympanoplasty because of chronic otitis media with and without cholesteatoma. Allograft epithelialisation was evaluated at the short-term postoperative visit by microscopic examination. Failures were reported if reperforation was observed. Fifty patients underwent allograft tympanoplasty: 34 received endoscopically procured ATOS and 16 received transcranially procured ATOS. One failed case was observed, in the endoscopic procurement group. We did not observe a statistically significant difference between the two groups in failure rate. This study demonstrates equivalence of the clinical outcome of allograft tympanoplasty using either endoscopic or transcranial procured ATOS and therefore indicates that the endoscopic technique can be considered the new standard procurement technique. Especially because the endoscopic procurement technique has several advantages compared to the former transcranial procurement technique: it avoids risk of prion transmission and it is faster while lacking any noticeable incision.

Effect of middle ear fluid on sound transmission and auditory brainstem response in guinea pigs.

PubMed

Guan, Xiying; Gan, Rong Z

2011-07-01

Combined measurements of middle ear transfer function and auditory brainstem response (ABR) in live guinea pigs with middle ear effusion (MEE) are reported in this paper. The MEE model was created by injecting saline into the middle ear cavity. Vibrations of the tympanic membrane (TM), the tip of the incus, and the round window membrane (RWM) were measured with a laser vibrometer at frequencies of 0.2-40 kHz when the middle ear fluid increased from 0 to 0.2 ml (i.e., full fill of the cavity). The click and pure tone ABRs were recorded as the middle ear fluid increased. Fluid introduction reduced mobility of the TM, incus and RWM mainly at high frequencies (f > 1 kHz). The magnitude of this reduction was related to the volume of fluid. The displacement transmission ratio of the TM to incus varied with frequency and fluid level. The volume displacement ratio of the oval window to round window was approximately 1.0 over most frequencies. Elevation of ABR thresholds and prolongation of ABR latencies were observed as fluid level increased. Reduction of TM displacement correlated well with elevation of ABR threshold at 0.5-8 kHz. Alterations in the ratio of ossicular displacements before and after fluid induction are consistent with fluid-induced changes in complex ossicular motions. Copyright © 2011 Elsevier B.V. All rights reserved.

Congenital oval or round window anomaly with or without abnormal facial nerve course: surgical results for 15 ears.

PubMed

Thomeer, Henricus; Kunst, Henricus; Verbist, Berit; Cremers, Cor

2012-07-01

To describe the audiometric results in a consecutive series of patients with congenital ossicular aplasia (Class 4a) or dysplasia of the oval and/or round window (Class 4b), which might include a possible anomalous course of the facial nerve. Retrospective chart study. Tertiary referral center. A tertiary referral center study with a total of 14 patients with congenital minor ear anomalies as part of a consecutive series (n = 89) who underwent exploratory tympanotomies (15 ears). Audiometric results. In 8 of 15 ears, ossicular reconstruction was attempted. In the short term (1 mo), there was a serviceable hearing outcome (air-bone gap closure to within 25 dB) in 4 ears. However, the long-term results showed deterioration because of an increased air-bone gap in all but 1 ear. No facial nerve lesion was observed postoperatively. Congenital dysplasia or aplasia of the oval and/or round window is an uncommon congenital minor ear anomaly. Classical microsurgical opportunities are rare in this group of anomalies. Newer options for hearing rehabilitation, such as the osseointegrated passive bone conduction devices, have become viable alternatives for conventional air conduction hearing devices. In the near future, upcoming active bone conduction devices might become the most preferred surgical option. In cases in which the facial nerve is only partially overlying the oval window, a type of malleostapedotomy procedure might result in a serviceable postoperative hearing level.

Titanium clip ball joint: a partial ossicular reconstruction prosthesis.

PubMed

Beutner, Dirk; Luers, Jan Christoffer; Bornitz, Matthias; Zahnert, Thomas; Huttenbrink, Karl-Bernd

2011-06-01

To describe a new titanium clip prosthesis for partial ossicular reconstruction with a micro ball joint in the headplate for compensation of tympanic membrane displacements. Laboratory experiments followed by 18 consecutive patients. A micro ball joint was implemented into a headplate of titanium middle ear prosthesis. First, the new prosthesis was tested in the laboratory in temporal bone experiments. Second, the new prosthesis was clinically installed in 18 patients. Results of laser Doppler vibrometry and force measurements in the laboratory experiments, analysis of a questionnaire, and preoperative and postoperative pure tone audiometry. The frictional resistance in the joint was measured to be 12 mN that should allow for adequate mobility under physiologic conditions. The effective sound transmission of the prosthesis was demonstrated by laser Doppler vibrometry. Intraoperatively, the installation of the prosthesis was always straightforward with headplate prosthesis shaft angles between 60 and 90 degrees. Postoperatively, pure tone audiometry revealed satisfying hearing results with a remaining average air-bone gap of 18.2 dB over the frequencies 500, 1,000, 2,000, and 3,000 Hz. No signs of prosthesis dislocation were discovered within the follow-up period of approximately 6 months. The experimental data show that the new modified prosthesis headplate fulfills the requirements necessary for sound transmission. The joint allows the plate to follow movements of the tympanic membrane. This characteristic in conjunction with the proven clip design ensure for optimal prosthesis placement and effectiveness.

Novel CAD/CAM rapid prototyping of next-generation biomedical devices

NASA Astrophysics Data System (ADS)

Doraiswamy, Anand

An aging population with growing healthcare needs demands multifaceted tools for diagnosis and treatment of health conditions. In the near-future, drug-administration devices, implantable devices/sensors, enhanced prosthesis, artificial and unique functional tissue constructs will become increasingly significant. Conventional technologies for mass-produced implants do not adequately take individual patient anatomy into consideration. Development of novel CAD/CAM rapid prototyping techniques may significantly accelerate progress of these devices for next-generation patient-care. In this dissertation, several novel rapid prototyping techniques have been introduced for next-generation biomedical applications. Two-photon polymerization was developed to microfabricate scaffolds for tissue engineering, microneedles for drug-delivery and ossicular replacement prostheses. Various photoplymers were evaluated for feasibility, mechanical properties, cytotoxicity, and surface properties. Laser direct write using MDW was utilized for developing microstructures of bioceramics such as hydroxyapatite, and viable mammalian osteosarcoma cells. CAD/CAM laser micromachining (CLM) was developed to engineer biointerfaces as surface recognition regions for differential adherence of cells and growth into tissue-like networks. CLM was also developed for engineering multi-cellular vascular networks. Cytotoxic evaluations and growth studies demonstrated VEGF-induced proliferation of HAAE-1 human aortic endothelial cells with inhibition of HA-VSMC human aortic smooth muscle cells. Finally, piiezoelectric inkjet printing was developed for controlled administration of natural and synthetic adhesives to overcome several problems associated with conventional tissue bonding materials, and greatly improve wound-repair in next generation eye repair, fracture fixation, organ fixation, wound closure, tissue engineering, and drug delivery devices.

Vibration of middle ear with shape memory prosthesis - Experimental and numerical study

NASA Astrophysics Data System (ADS)

Rafal, Rusinek; Szymanski, Marcin; Lajmert, Pawel

2018-01-01

The paper presents experimental investigations of ossicular chain vibrations using a Laser Doppler Vibrometer (LDV) for the intact middle ear and a reconstructed one by means of the new designed shape memory prosthesis. Vibrations of the round window are measured with the Laser Doppler vibrometer and studied classically by the transfer function analysis. Moreover, the recurrence plot technique and the Hilbert vibration decomposition method are used to extend the classical analysis. The new methods show additional vibrations components and provide more information about middle ear behaviour.

Optical Coherence Tomography of the Tympanic Membrane and Middle Ear: A Review.

PubMed

Tan, Hsern Ern Ivan; Santa Maria, Peter Luke; Wijesinghe, Philip; Francis Kennedy, Brendan; Allardyce, Benjamin James; Eikelboom, Robert Henry; Atlas, Marcus David; Dilley, Rodney James

2018-05-01

Objective To evaluate the recent developments in optical coherence tomography (OCT) for tympanic membrane (TM) and middle ear (ME) imaging and to identify what further development is required for the technology to be integrated into common clinical use. Data Sources PubMed, Embase, Google Scholar, Scopus, and Web of Science. Review Methods A comprehensive literature search was performed for English language articles published from January 1966 to January 2018 with the keywords "tympanic membrane or middle ear,"optical coherence tomography," and "imaging." Conclusion Conventional imaging techniques cannot adequately resolve the microscale features of TM and ME, sometimes necessitating diagnostic exploratory surgery in challenging otologic pathology. As a high-resolution noninvasive imaging technique, OCT offers promise as a diagnostic aid for otologic conditions, such as otitis media, cholesteatoma, and conductive hearing loss. Using OCT vibrometry to image the nanoscale vibrations of the TM and ME as they conduct acoustic waves may detect the location of ossicular chain dysfunction and differentiate between stapes fixation and incus-stapes discontinuity. The capacity of OCT to image depth and thickness at high resolution allows 3-dimensional volumetric reconstruction of the ME and has potential use for reconstructive tympanoplasty planning and the follow-up of ossicular prostheses. Implications for Practice To achieve common clinical use beyond these initial discoveries, future in vivo imaging devices must feature low-cost probe or endoscopic designs and faster imaging speeds and demonstrate superior diagnostic utility to computed tomography and magnetic resonance imaging. While such technology has been available for OCT, its translation requires focused development through a close collaboration between engineers and clinicians.

Virtual reality case-specific rehearsal in temporal bone surgery: a preliminary evaluation.

PubMed

Arora, Asit; Swords, Chloe; Khemani, Sam; Awad, Zaid; Darzi, Ara; Singh, Arvind; Tolley, Neil

2014-01-01

1. To investigate the feasibility of performing case-specific surgical rehearsal using a virtual reality temporal bone simulator. 2. To identify potential clinical applications in temporal bone surgery. Prospective assessment study. St Mary's Hospital, Imperial College NHS Trust, London UK. Sixteen participants consisting of a trainer and trainee group. Twenty-four cadaver temporal bones were CT-scanned and uploaded onto the Voxelman simulator. Sixteen participants performed a 90-min temporal bone dissection on the generic simulation model followed by 3 dissection tasks on the case simulation and cadaver models. Case rehearsal was assessed for feasibility. Clinical applications and usefulness were evaluated using a 5-point Likert-type scale. The upload process required a semi-automated system. Average time for upload was 20 min. Suboptimal reconstruction occurred in 21% of cases arising when the mastoid process and ossicular chain were not captured (n = 2) or when artefact was generated (n = 3). Case rehearsal rated highly (Likert score >4) for confidence (75%), facilitating planning (75%) and training (94%). Potential clinical applications for case rehearsal include ossicular chain surgery, cochlear implantation and congenital anomalies. Case rehearsal of cholesteatoma surgery is not possible on the current platform due to suboptimal soft tissue representation. The process of uploading CT data onto a virtual reality temporal bone simulator to perform surgical rehearsal is feasible using a semi-automated system. Further clinical evaluation is warranted to assess the benefit of performing patient-specific surgical rehearsal in selected procedures. Copyright © 2013 Surgical Associates Ltd. Published by Elsevier Ltd. All rights reserved.

Technical note: a landmark-based approach to the study of the ear ossicles using ultra-high-resolution X-ray computed tomography data.

PubMed

Schmidt, Jodi L; Cole, Theodore M; Silcox, Mary T

2011-08-01

Previous study of the ear ossicles in Primates has demonstrated that they vary on both functional and phylogenetic bases. Such studies have generally employed two-dimensional linear measurements rather than three-dimensional data. The availability of Ultra- high-resolution X-ray computed tomography (UhrCT) has made it possible to accurately image the ossicles so that broadly accepted methodologies for acquiring and studying morphometric data can be applied. Using UhrCT data also allows for the ossicular chain to be studied in anatomical position, so that it is possible to consider the spatial and size relationships of all three bones. One issue impeding the morphometric study of the ear ossicles is a lack of broadly recognized landmarks. Distinguishing landmarks on the ossicles is difficult in part because there are only two areas of articulation in the ossicular chain, one of which (the malleus/incus articulation) has a complex three-dimensional form. A measurement error study is presented demonstrating that a suite of 16 landmarks can be precisely located on reconstructions of the ossicles from UhrCT data. Estimates of measurement error showed that most landmarks were highly replicable, with an average CV for associated interlandmark distances of less than 3%. The positions of these landmarks are chosen to reflect not only the overall shape of the bones in the chain and their relative positions, but also functional parameters. This study should provide a basis for further examination of the smallest bones in the body in three dimensions. Copyright © 2011 Wiley-Liss, Inc.

Sensorineural hearing loss in patients with chronic suppurative otitis media: Is there a significant correlation?

PubMed

Amali, Amin; Hosseinzadeh, Nima; Samadi, Shahram; Nasiri, Shirin; Zebardast, Jayran

2017-02-01

Hearing loss as a sequel of chronic suppurative otitis media (CSOM) is often conductive, but recent studies have found an additional sensorineural component in these patients, thus demonstrating inner ear damage. The aim of the study was to determine the association between CSOM and sensorineural hearing loss (SNHL) and to assess the influence of patient's age, duration of disease, and presence of cholesteatoma and ossicular erosion on the degree of SNHL. In a retrospective study, the medical records of 119 patients who underwent surgery was reviewed. Seventy patients met the inclusion criteria of unilateral otorrhea, normal contralateral ear on otoscopy, and age between 10-65 years with no history of head trauma or ear surgery or familial hearing loss. Bone conduction (BC) thresholds for affected and contralateral ear were measured at frequencies of 500, 1000, 2000, and 4000 Hz. Data analysis was performed using SPSS 13 with independent-samples t-test, Pearson correlation test, and two-tailed analysis. A p ≤ 0.05 was considered statistically significant. Significant higher BC thresholds were found in the affected ear than in the normal ear for each frequency (p < 0.001), which increased with increasing frequency (7.00 dB at the 500 Hz and 9.71 dB at the 4000 Hz). There was a significant correlation between age and degree of SNHL (r = 0.422, p < 0.001) but no significant correlation was in duration of the disease (r = 0.119, p > 0.05). There was no relationship between presence of cholesteatoma and ossicular erosion with SNHL (p > 0.05). These findings demonstrate that CSOM is associated with some degree of SNHL and cochlear damage, and higher frequencies are more affected. Aging can act as a precipitating factor in this pathological process.

Management of pediatric cholesteatoma based on presentations, complications, and outcomes.

PubMed

McGuire, J K; Wasl, H; Harris, T; Copley, G J; Fagan, J J

2016-01-01

To highlight important aspects and paradigms in the management of paediatric cholesteatoma in a developing world setting. A retrospective audit was conducted of paediatric cholesteatomas that underwent tympanomastoid surgery between 2008 and 2012 at the Red Cross War Memorial Children's Hospital in Cape Town. The following was audited: initial presentation; cholesteatoma complications; types of surgery, intraoperative findings and outcomes of surgery in terms of hearing, otorrhoea and recidivism; and the reliability of follow-up and how this might influence the type of surgery. Fifty-seven children aged 2-13 years with 61 cholesteatomas (4 bilateral) were reviewed. Fifty-five mastoidectomies were done; 11% presented with complicated cholesteatoma. Referrals from primary care were significantly delayed (>6 months) in 76%. Canal wall down surgery was done in 71%. Forty-five percent had improved hearing (within 15dB of better hearing ear) and a further 15% had no or only mild hearing loss. Ossicular chain involvement and ossicles encased in inflammatory tissue were associated with poorer hearing outcomes. Sixty-four percent of ears remained dry. Forty-five percent of the canal wall up, and 23% of canal wall down mastoidectomies had recidivism. Twenty-six percent of patients were lost to follow-up. Children are likely to present with advanced cholesteatoma with ossicular chain involvement. The children present with high rates of complications, poor pre-operative hearing and have high recurrence rates post-surgery. Referral from primary health care is delayed. Canal wall down procedures may be appropriate in a setting where patient follow-up is unreliable and access to operating theatre is limited. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Cost effective use of audiograms after pediatric temporal bone fractures.

PubMed

Frisenda, Julia L; Schroeder, James W; Ryan, Maura E; Valika, Taher S; Billings, Kathleen R

2015-11-01

To identify the relationship of pediatric temporal fractures to the incidence and type of hearing loss present. To analyze the timing and utility of audiometric testing in children with temporal bone fractures. Retrospective case series of 50 pediatric patients with temporal bone fractures who were treated at an urban, tertiary care children's hospital from 2008 to 2014. A statistical analysis of predictors of hearing loss after temporal bone fracture was performed. Fifty-three fractures (69.7%) in 50 patients involved the petrous portion of the temporal bone. The mean age of patients was 7.13 years, and 39 (73.6%) were male. A fall was the most common mechanism of injury in 28 (52.8%) patients, followed by crush injury (n=14, 26.2%), and vehicular trauma (n=10, 18.9%). All otic capsule violating fractures were associated with a sensorineural hearing loss (n=4, 7.5%, p=0.002). Three of four otic capsule sparing fractures were associated with ossicular dislocation, with a corresponding mixed or conductive hearing loss on follow up audiometric testing. The majority of otic capsule sparing fracture patients (n=19/43, 44.2%) who had follow up audiograms had normal hearing, and those with otic capsule violating fractures were statistically more likely to have persistent hearing loss than those with otic capsule sparing fractures (p=0.01). Patients with otic capsule violating fractures or those with ossicular disruption are at higher risk for persistent hearing loss. Cost-saving may be accrued by selecting only those patients at high risk for persistent hearing loss for audiometric testing after temporal bone fractures. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Sheep as a large animal ear model: Middle-ear ossicular velocities and intracochlear sound pressure.

PubMed

Péus, Dominik; Dobrev, Ivo; Prochazka, Lukas; Thoele, Konrad; Dalbert, Adrian; Boss, Andreas; Newcomb, Nicolas; Probst, Rudolf; Röösli, Christof; Sim, Jae Hoon; Huber, Alexander; Pfiffner, Flurin

2017-08-01

Animals are frequently used for the development and testing of new hearing devices. Dimensions of the middle ear and cochlea differ significantly between humans and commonly used animals, such as rodents or cats. The sheep cochlea is anatomically more like the human cochlea in size and number of turns. This study investigated the middle-ear ossicular velocities and intracochlear sound pressure (ICSP) in sheep temporal bones, with the aim of characterizing the sheep as an experimental model for implantable hearing devices. Measurements were made on fresh sheep temporal bones. Velocity responses of the middle ear ossicles at the umbo, long process of the incus and stapes footplate were measured in the frequency range of 0.25-8 kHz using a laser Doppler vibrometer system. Results were normalized by the corresponding sound pressure level in the external ear canal (P EC ). Sequentially, ICSPs at the scala vestibuli and tympani were then recorded with custom MEMS-based hydrophones, while presenting identical acoustic stimuli. The sheep middle ear transmitted most effectively around 4.8 kHz, with a maximum stapes velocity of 0.2 mm/s/Pa. At the same frequency, the ICSP measurements in the scala vestibuli and tympani showed the maximum gain relative to the P EC (24 dB and 5 dB, respectively). The greatest pressure difference across the cochlear partition occurred between 4 and 6 kHz. A comparison between the results of this study and human reference data showed middle-ear resonance and best cochlear sensitivity at higher frequencies in sheep. In summary, sheep can be an appropriate large animal model for research and development of implantable hearing devices. Copyright © 2017 Elsevier B.V. All rights reserved.

Challenges and outcomes of cholesteatoma management in children with Down syndrome.

PubMed

Ghadersohi, Saied; Bhushan, Bharat; Billings, Kathleen R

2018-03-01

The high incidence of chronic otitis media with effusion and Eustachian tube dysfunction in children with Down syndrome (DS) may predispose them to cholesteatoma formation. Establishing the diagnosis, choosing the appropriate operative intervention, and post-operative care can be challenging. To describe management strategies for cholesteatoma diagnosis, surgical treatment, and post-operative management in children with Down syndrome. Retrospective case series of 14 patients (17 total ears) with Down syndrome diagnosed with cholesteatoma over a 9-year period. A total of 14 patients with cholesteatoma (3 with bilateral disease) were analyzed. Thirteen ears (76.5%) had ≥2 tympanostomy tubes insertions prior to cholesteatoma diagnosis, and otorrhea and hearing loss were the most common presenting symptoms. Common pre-operative CT scan findings included mastoid sclerosis and ossicular erosion. The average age at first surgery was 9.8 years, and the average follow-up was 4.3 years. For acquired cholesteatoma, most ears were managed with canal wall up (CWU) approaches, but ultimately 6/15 (40.0%) required canal wall down (CWD) approaches. Postoperatively, 3 (20.0%) ears developed new tympanic membrane retraction pockets, but no recurrent cholesteatoma. Four (26.7%) ears developed recurrent disease, and 3 (20.0%) had residual disease at secondary procedures. Ossiculoplasty was performed in 4 ears. Twelve (70.6%) ears were rehabilitated with hearing aids or FM systems. The diagnosis of cholesteatoma in Down syndrome was associated with otorrhea, hearing loss, and CT scan findings of ossicular erosion and mastoid sclerosis. Most cases were managed with CWU surgical approaches. Hearing aid use was common post-operatively. Copyright © 2018 Elsevier B.V. All rights reserved.

[Lysis of the incus long process and incudostapedial rebridging ossiculoplasty: comparative study of titanium-gold angle prosthesis Plester-type versus Martin Incudo prosthesis hydroxylapatite].

PubMed

Faye, M B; Martin, C; Schmerber, S

2013-01-01

We report two surgical techniques devised to restore a disrupted incudostapedial joint. Thirty patients underwent rebridging of distal portion of incus long process in the ENT Department of University of Grenoble and Saint-Etienne, between October 1998 and September 2002. Two types of ossicular prostheses were used: A titanium-gold angle prosthesis according to Plester Winkel Kurz (n = 16 patients), and a hydroxylapatite prosthesis as Martin Incudo Prosthesis (n = 14 patients). The average hearing gain in short term is of 8.30 dB for the Martin-Incudo group. It is of 5.23 dB in the Winkel group. Seven and three cases of failures (Residual Rinne > 20 dB) were noticed respectively in the groups Martin-Incudo and Winkel. Seven and four cases of labyrinthisation were observed respectively in the groups Martin-Incudo and Winkel. The average hearing gain in long term is 3.43 dB in the Martin-Incudo group; and 2.85 dB among patients with Winkel Kurz prosthesis. Average residual Rinne is higher than 20 dB in the Winkel group. The hearing gain is not statistically significant between the two groups (p > 0.05). The titanium partial prosthesis did not give good functional results. In the case of a limited lysis (< 2 mm) of the distal portion of incus, we use the cement or cartilage interposition. When ossicular chain cannot be preserved entirely, we privilege incus transposition or a titanium PORP. The Martin-Incudo prosthesis seems interesting in the event of lysis of 2 mm of the long process of incus, nevertheless engineering changes are necessary in order to make rigid the incudostapedial joint.

Feasibility of spectral-domain phase-sensitive optical coherence tomography for middle ear vibrometry

PubMed Central

Nguyen-Huynh, Anh; Wang, Ruikang K.; Jacques, Steven L.; Choudhury, Niloy; Nuttall, Alfred L.

2012-01-01

Abstract. We describe a novel application of spectral-domain phase-sensitive optical coherence tomography (SD PS-OCT) to detect the tiny motions of the middle ear structures, such as the tympanic membrane and ossicular chain, and their morphological features for differential diagnosis of CHL. This technique has the potential to provide meaningful vibration of ossicles with a vibration sensitivity of ∼0.5  nm at 1 kHz of acoustic stimulation. To the best of our knowledge, this is the first demonstration of depth-resolved vibration imaging of ossicles with a PS-OCT system at a nanometer scale. PMID:22734728

Benefits of active middle ear implants in mixed hearing loss: Stapes versus round window.

PubMed

Lee, Jeon Mi; Jung, Jinsei; Moon, In Seok; Kim, Sung Huhn; Choi, Jae Young

2017-06-01

We compared the audiologic benefits of active middle ear implants with those of passive middle ear implants with hearing aids in mixed hearing loss, and also compared the outcomes of stapes vibroplasty with those of round window vibroplasty. Retrospective chart review. Thirty-four patients with mixed hearing loss due to chronic otitis media were treated with a middle ear implant. Of these, 15 were treated with a passive middle ear implant (conventional ossiculoplasty with a partial ossicular replacement prosthesis), nine with an active middle ear implant coupling to the stapes, and 10 with an active middle ear implant coupling to the round window. Patients underwent pure-tone/free-field audiograms and speech discrimination tests before surgery and 6 months after surgery, and the results of these tests were compared. The active middle ear implant resulted in better outcomes than the passive middle ear implant with hearing aids at mid to high frequencies (P < .05). Patients who received either a stapes vibroplasty or a round window vibroplasty showed comparable hearing gain except at 8,000 Hz (48.9 dB vs. 31.0 dB, P < .05). Patients who received a stapes vibroplasty showed an improvement even in bone conduction at 1,000 Hz and 2,000 Hz (both P < .05). Active middle ear implantation could be a better option than treatment with passive middle ear implants with hearing aids for achieving rehabilitation in patients with mixed hearing loss. Vibroplasty via either oval window or round window stimulation shares similar good results. 4 Laryngoscope, 127:1435-1441, 2017. © 2016 The American Laryngological, Rhinological and Otological Society, Inc.

Laser Doppler vibrometry: new ENT applications

NASA Astrophysics Data System (ADS)

Stasche, Norbert; Baermann, M.; Kempe, C.; Hoermann, Karl; Foth, Hans-Jochen

1996-12-01

Common audiometry often does not really allow a reliable and objective differential diagnosis of hearing disorders such as otosclerosis, adhesive otitis, ossicular interruption or tinnitus, even though several methods might be used complementarily. In recent years, some experimental studies on middle ear mechanics established laser Doppler vibrometry (LDV) as a useful method allowing objective measurement of human tympanic membrane displacement. The present study on LDV investigated the clinical use of this new method under physiological conditions. LDV proved to be a fast, reproducible, non-invasive and very sensitive instrument to characterize ear-drum vibrations in various middle ear dysfunctions, except in tinnitus patients. For future applications, improved optical characteristics of the vibrometer might result in a better differential diagnosis of subjective and objective tinnitus, otoacoustic emissions or Morbus Meniere.

CT scans and 3D reconstructions of Florida manatee (Trichechus manatus latirostris) heads and ear bones.

PubMed

Chapla, Marie E; Nowacek, Douglas P; Rommel, Sentiel A; Sadler, Valerie M

2007-06-01

The auditory anatomy of the Florida manatee (Trichechus manatus latirostris) was investigated using computerized tomography (CT), three-dimensional reconstructions, and traditional dissection of heads removed during necropsy. The densities (kg/m3) of the soft tissues of the head were measured directly using the displacement method and those of the soft tissues and bone were calculated from CT measurements (Hounsfield units). The manatee's fatty tissue was significantly less dense than the other soft tissues within the head (p<0.05). The squamosal bone was significantly less dense than the other bones of the head (p<0.05). Measurements of the ear bones (tympanic, periotic, malleus, incus, and stapes) collected during dissection revealed that the ossicular chain was overly massive for the mass of the tympanoperiotic complex.

[Evaluation of a training system for middle ear surgery with optoelectric detection].

PubMed

Strauss, G; Bahrami, N; Pössneck, A; Strauss, M; Dietz, A; Korb, W; Lüth, T; Haase, R; Moeckel, H; Grunert, R

2009-10-01

This work presents a new training concept for surgery of the temporal bone. It is based on a model of gypsum plastic with optoelectric detection of risk structures. A prototypical evaluation is given. The training models are based on high-resolution computed tomographic data of a human skull. The resulting data set was printed by a three-dimensional (3D) printer. A 3D phantom is created from gypsum powder and a bonding agent. Risks structures are the facial nerve, semicircular canal, cochlea, ossicular chain, sigmoid sinus, dura, and internal carotid artery. An electrically conductive metal (Wood's metal) and a fiber-optic cable were used as detection materials for the risk structures. For evaluating the training system, a study was done with eight inexperienced and eight experienced ear surgeons. They were asked to perform temporal bone surgery using two identical training models (group A). In group B, the same surgeons underwent surgical training with human cadavers. In the case of injuries, the number, point in time, degree (facial nerve), and injured structure were documented during the training on the model. In addition, the total time needed was noted. The training systems could be used in all cases. Evaluation of the anatomic accuracy of the models showed results that were between 49.5% and 90% agreement with the anatomic origin. Error detection was evaluated with values between 79% and 100% agreement with the perception of an experienced surgeon. The operating setting was estimated to be better than the previous"gold standard." The possibility of completely replacing the previous training method, which uses cadavers, with the examined training model was affirmed. This study shows that the examined system fulfills the conditions for a new training concept for temporal bone surgery. The system connects the preliminary work with printed and sintered models with the possibilities of microsystem engineering. In addition, the model's digital database permits a complete virtual representation of the model with appropriate further applications ("look behind the wall," virtual endoscopy).

Endoscopy-Assisted Ear Surgery for Treatment of Chronic Otitis Media With Cholesteatoma, Adhesion, or Retraction Pockets.

PubMed

Ulku, Cagatay Han

2017-06-01

The objective of this study was to analyze the results of endoscopy-assisted ear surgery for the treatment of chronic otitis media with cholesteatoma, adhesion, or retraction pockets.Fifty-one patients who underwent oto-endoscopy-assisted canal wall up tympanomastoid surgery and/or limited anterior atticotomy with tympanoplasty for chronic otitis media with cholesteatoma, adhesion, or retraction pocket from 2006 to 2013 have been included in this study. Eradication of the disease from the middle ear and mastoid air cells was achieved by combination of the oto-microscobic and oto-endoscopic approaches. Second look surgery was performed 18 months later from the initial surgery in selected patients. Age, gender, pre-/postoperative otoscopy findings/audiograms, type of the used prostheses, and follow-up time were obtained from the patient's file. Anatomic integrity rates of the tympanic membrane, the mean gains of air bone gap, on pure-tone audiogram at 4 frequencies and existence of the residual disease were reviewed parameters. Functional evaluation was made in patients with intact tympanic membrane.Of the 51 patients, the ratios of the chronic otitis media with cholesteatoma and isolated adhesive otitis or retraction pocket cases were 74.5% (38/51) and 25.5% (13/51), respectively. Ossicular chain reconstruction was made with PORP in 27 patients and TORP in 20 patients, whereas the ossicular chain was intact in 4 patients. Anatomic integrity rates of the tympanic membrane were 90.2% (46/51). The overall (n = 46) pre-/postoperative mean ABG obtained at 4 frequencies were 28.3 ± 12.26 and 9.18 ± 5.68 dB (P < 0.0001) respectively. Residual cholesteatoma rate was 10.5% (34/38) for chronic otitis media with cholesteatoma patients. However, there was no recurrence or new cholesteatoma formation in isolated retraction pockets or adhesive otitis patients.Oto-endoscopic eradication of the cholesteatoma or epithelial tissue from hidden area after the all visible cholesteatoma removal by oto-microscope improves the quality of surgery, significantly decreases the frequency of the canal wall-down procedure and posterior tympanotomy requirements with acceptable residual cholesteatoma rates.

Structures that Contribute to Middle-Ear Admittance in Chinchilla

PubMed Central

Rosowski, John J.; Ravicz, Michael E.; Songer, Jocelyn E.

2009-01-01

We describe measurements of middle-ear input admittance in chinchillas (Chinchilla lanigera) before and after various manipulations that define the contributions of different middle-ear components to function. The chinchilla’s middle-ear air spaces have a large effect on the low-frequency compliance of the middle ear, and removing the influences of these spaces reveals a highly admittant tympanic membrane and ossicular chain. Measurements of the admittance of the air spaces reveal that the high-degree of segmentation of these spaces has only a small effect on the admittance. Draining the cochlea further increases the middle-ear admittance at low frequencies and removes a low-frequency (less than 300 Hz) level dependence in the admittance. Spontaneous or sound-driven contractions of the middle-ear muscles in deeply anesthetized animals were associated with significant changes in middle-ear admittance. PMID:16944166

Transmission matrix analysis of the chinchilla middle ear

PubMed Central

Songer, Jocelyn E.; Rosowski, John J.

2008-01-01

Despite the common use of the chinchilla as an animal model in auditory research, a complete characterization of the chinchilla middle ear using transmission matrix analysis has not been performed. In this paper we describe measurements of middle-ear input admittance and stapes velocity in ears with the middle-ear cavity opened under three conditions: intact tympano-ossicular system and cochlea, after the cochlea has been drained, and after the stapes has been fixed. These measurements, made with stimulus frequencies of 100–8000 Hz, are used to define the transmission matrix parameters of the middle ear and to calculate the cochlear input impedance as well as the middle-ear output impedance. This transmission characterization of the chinchilla middle ear will be useful for modeling auditory sensitivity in the normal and pathological chinchilla ear. PMID:17672642

Early hominin auditory ossicles from South Africa

PubMed Central

Quam, Rolf M.; de Ruiter, Darryl J.; Masali, Melchiorre; Arsuaga, Juan-Luis; Martínez, Ignacio; Moggi-Cecchi, Jacopo

2013-01-01

The middle ear ossicles are only rarely preserved in fossil hominins. Here, we report the discovery of a complete ossicular chain (malleus, incus, and stapes) of Paranthropus robustus as well as additional ear ossicles from Australopithecus africanus. The malleus in both early hominin taxa is clearly human-like in the proportions of the manubrium and corpus, whereas the incus and stapes resemble African and Asian great apes more closely. A deep phylogenetic origin is proposed for the derived malleus morphology, and this may represent one of the earliest human-like features to appear in the fossil record. The anatomical differences found in the early hominin incus and stapes, along with other aspects of the outer, middle, and inner ear, are consistent with the suggestion of different auditory capacities in these early hominin taxa compared with modern humans. PMID:23671079

Biomedical Simulation Models of Human Auditory Processes

NASA Technical Reports Server (NTRS)

Bicak, Mehmet M. A.

2012-01-01

Detailed acoustic engineering models that explore noise propagation mechanisms associated with noise attenuation and transmission paths created when using hearing protectors such as earplugs and headsets in high noise environments. Biomedical finite element (FE) models are developed based on volume Computed Tomography scan data which provides explicit external ear, ear canal, middle ear ossicular bones and cochlea geometry. Results from these studies have enabled a greater understanding of hearing protector to flesh dynamics as well as prioritizing noise propagation mechanisms. Prioritization of noise mechanisms can form an essential framework for exploration of new design principles and methods in both earplug and earcup applications. These models are currently being used in development of a novel hearing protection evaluation system that can provide experimentally correlated psychoacoustic noise attenuation. Moreover, these FE models can be used to simulate the effects of blast related impulse noise on human auditory mechanisms and brain tissue.

Dislocation of the incus into the external auditory canal after mountain-biking accident.

PubMed

Saito, T; Kono, Y; Fukuoka, Y; Yamamoto, H; Saito, H

2001-01-01

We report a rare case of incus dislocation to the external auditory canal after a mountain-biking accident. Otoscopy showed ossicular protrusion in the upper part of the left external auditory canal. CT indicated the disappearance of the incus, and an incus-like bone was found in the left external auditory canal. There was another bony and board-like structure in the attic. During the surgery, a square-shaped bony plate (1 x 1 cm) was found in the attic. It was determined that the bony plate had fallen from the tegmen of the attic. The fracture line in the posterosuperior auditory canal extending to the fossa incudis was identified. According to these findings, it was considered that the incus was pushed into the external auditory canal by the impact of skull injury through the fractured posterosuperior auditory canal, which opened widely enough for incus dislocation. Copyright 2001 S. Karger AG, Basel

Middle ear abnormalities in Van Maldergem syndrome.

PubMed

Verheij, Emmy; Thomeer, Henricus G X M; Pameijer, Frank A; Topsakal, Vedat

2017-01-01

Van Maldergem syndrome (VMS) is a very rare syndrome that was first described in 1992. The main features of this syndrome comprise intellectual disability, blepharo-naso-facial malformation, and hand anomalies. Almost all nine described patients have been shown to be affected by conductive hearing impairment attributed to microtia, and atresia of the outer ear canal. Here, we present a VMS patient with congenital malformations of the middle ear as the main reason for severe conductive bilateral hearing impairment. To our knowledge, this is the first report to describe middle ear abnormalities in VMS. These malformations were seen on high resolution Computed Tomography scanning and during an exploratory tympanotomy. Due to the severity of the middle ear abnormalities and the risk for facial nerve damage, the patient was not offered an ossicular chain reconstruction but a bone conduction device after this exploratory tympanotomy. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Of mice, moles and guinea pigs: functional morphology of the middle ear in living mammals.

PubMed

Mason, Matthew J

2013-07-01

The middle ear apparatus varies considerably among living mammals. Body size, phylogeny and acoustic environment all play roles in shaping ear structure and function, but experimental studies aimed ultimately at improving our understanding of human hearing can sometimes overlook these important species differences. This review focuses on three groups of mammals, bringing together anatomical, zoological and physiological information in order to highlight unusual features of their middle ears and attempt to interpret their function. "Microtype" ears, found in species such as mice and bats, are associated with high-frequency hearing. The orbicular apophysis, the focus of some recent developmental studies on mouse ears, is characteristic of microtype mallei but is not found in humans or other "freely mobile" species. The apophysis increases ossicular inertia about the anatomical axis of rotation: its adaptive purpose in a high-frequency ear is still not clear. Subterranean mammals have convergently evolved a "freely mobile" ossicular morphology which appears to favour lower-frequency sound transmission. More unusual features found in some of these animals include acoustically coupled middle ear cavities, the loss of middle ear muscles and hypertrophied ossicles which are believed to subserve a form of inertial bone conduction. Middle ears of the rodent group Ctenohystrica (which includes guinea pigs and chinchillas, important models in hearing research) show some striking characteristics which together comprise a unique type of auditory apparatus requiring a classification of its own, referred to here as the "Ctenohystrica type". These characteristics include a distinctive malleus morphology, fusion of the malleus and incus, reduction or loss of the stapedius muscle, a synovial stapedio-vestibular articulation and, in chinchillas, enormously expanded middle ear cavities. These characteristics may be functionally linked and associated with the excellent low-frequency hearing found in these animals. The application of new experimental and imaging data into increasingly sophisticated models continues to improve our understanding of middle ear function. However, a more rigorous comparative approach and a better appreciation of the complex patterns of convergent and divergent evolution reflected in the middle ear structures of living mammals are also needed, in order to put findings from different species into the appropriate context. This article is part of a special issue entitled "MEMRO 2012". Copyright © 2012 Elsevier B.V. All rights reserved.

[Hearing and balance in metabolic bone diseases].

PubMed

Zatoński, Tomasz; Temporale, Hanna; Krecicki, Tomasz

2012-03-01

There are reports that hearing loss is one of the clinical manifestations of metabolic bone diseases. Demineralization can lead to a reduction in ossicular mass. Paget's disease can reveal loss of mineral density of the cochlear bone. Ear bone remodeling in osteoporosis is similar to the changes in otosclerosis. Moreover, osteoporosis, osteogenesis imperfecta and otosclerosis have a similar genetic mechanism. According to some researchers osteopenia and osteoporosis may well be associated with idiopathic benign positional vertigo (BPV). Dysfunction of the organ of hearing and balance in patients with renal insufficiency may be due to disturbances in calcium phosphate balance and renal osteodystrophy in the course of the disease. Proving the presence of hearing loss in patients with metabolic bone diseases may lead to determining the new indications for bone densitometry in some patients with hearing impairment. Furthermore, audiological examination in patients with osteoporosis may be important because of the impact of hearing loss on prognosis for patients with metabolic bone diseases.

Ossicular density in golden moles (Chrysochloridae).

PubMed

Mason, Matthew J; Lucas, Sarah J; Wise, Erica R; Stein, Robin S; Duer, Melinda J

2006-12-01

The densities of middle ear ossicles of golden moles (family Chrysochloridae, order Afrosoricida) were measured using the buoyancy method. The internal structure of the malleus was examined by high-resolution computed tomography, and solid-state NMR was used to determine relative phosphorus content. The malleus density of the desert golden mole Eremitalpa granti (2.44 g/cm3) was found to be higher than that reported in the literature for any other terrestrial mammal, whereas the ossicles of other golden mole species are not unusually dense. The increased density in Eremitalpa mallei is apparently related both to a relative paucity of internal vascularization and to a high level of mineralization. This high density is expected to augment inertial bone conduction, used for the detection of seismic vibrations, while limiting the skull modifications needed to accommodate the disproportionately large malleus. The mallei of the two subspecies of E. granti, E. g. granti and E. g. namibensis, were found to differ considerably from one another in both size and shape.

Vibrant Soundbridge Implantation: Floating Mass Transducer Coupled with the Stapes Head and Embedded in Fat.

PubMed

Liu, Qingsong; Feng, Guodong; Shang, Yingying; Wang, Suju; Gao, Zhiqiang

2018-04-26

Subtotal petrosectomy may be performed for refractory chronic middle ear diseases, such as massive cholesteatoma or recurrent otitis media. It involves permanent obliteration of the operative cavity, thus precluding the chance to restore conductive hearing via traditional inertial ossicular prostheses. The Vibrant Soundbridge (VSB) is an alternative option for hearing rehabilitation. Vibrant energy is delivered into the inner ear via a floating mass transducer (FMT), which can be coupled with any part of the middle ear acoustic transmission structure. To restore the hearing of a young woman with cholesteatoma, we combined subtotal petrosectomy with obliteration of the cavity and VSB implantation with an FMT coupled to the stapes head. Two years of follow-up demonstrated excellent auditory rehabilitation, improved sound source localization ability, and a lower speech recognition threshold. This study showed that the FMT works well in an obliterated cavity, and the experience acquired through this successful exploration is worth disseminating. © 2018 S. Karger AG, Basel.

Frequency of auditory involvement and of associated factors in patients with juvenile idiopathic arthritis.

PubMed

Céspedes Cruz, Adriana Ivonne; Méndez Núñez, Myriam; Solís Vallejo, Eunice; Zeferino Cruz, Maritza; Torres Jiménez, Alfonso Ragnar; Ocampo Sánchez, Verónica; Flores Meza, Beatriz; Quintana Ruiz, Norma

2017-09-08

Juvenile idiopathic arthritis (JIA) is a chronic autoimmune disease characterized by the presence of arthritis in children under 16 years of age for more than 6 weeks in the absence of any other known cause. The extra-articular manifestations, especially in the audiovestibular system, are related to the involvement of the joints of the ossicular chain as a result of the inflammatory process in the synovium. Previous clinical studies in pediatric patients have shown conductive or sensorineural hearing loss. The aim of this study was to assess the frequency of hearing impairment and of associated factors in patients with JIA. A prospective, analytical study was conducted from January 2013 to August 2014 in 62 patients with JIA aged between 5 and 15 years. The study was approved by the local ethics committee and parents signed their informed consent. All subjects underwent audiological examination involving otomicroscopy, audiometry, tympanometry, stapedius reflex and test for transient otoacoustic emissions (TOAE); rheumatologic evaluation included joint examination and the application of a measure of functional ability (disability) using the Childhood Health Assessment Questionnaire (CHAQ). Measures of central tendency and of dispersion were used (chi-square for associations and P<.05 for statistical significance). Sixty-two patients were included: 56 girls and 6 boys, mean age 11.9 years and mean disease duration of 3.4 years; 46% had rheumatoid factor (RF)- positive polyarticular JIA, 40% had RF-negative polyarticular JIA, 15% had disease of systemic onset and 3% had oligoarthritis. Active disease was found in 29 patients and 33 were in remission with medication. Of the total of 124 ears evaluated according to the Jerger classification for tympanometry, abnormal findings were observed in 78 that were type As and in 1 that was type Ad, whereas there were 45 type A ears. Hearing loss was disclosed by speech audiometry, rather than by pure tone audiometry. The TOAE were absent in 4% of those assessed and the stapedius reflex was absent in less than 10%. Factors that had a positive correlation with hearing impairment were RF-positive polyarticular JIA, disease duration, degree of disability and the erythrocyte sedimentation rate level (P<.000). The presence of an abnormal tympanogram suggested early involvement in the structure of the tympanic-ossicular complex; however, 3.4 years later, no hearing loss had been reported. Copyright © 2017 Elsevier España, S.L.U. and Sociedad Española de Reumatología y Colegio Mexicano de Reumatología. All rights reserved.

[Virtual otoscopy--technique, indications and initial experiences with multislice spiral CT].

PubMed

Klingebiel, R; Bauknecht, H C; Lehmann, R; Rogalla, P; Werbs, M; Behrbohm, H; Kaschke, O

2000-11-01

We report the standardized postprocessing of high-resolution CT data acquired by incremental CT and multi-slice CT in patients with suspected middle ear disorders to generate three-dimensional endoluminal views known as virtual otoscopy. Subsequent to the definition of a postprocessing protocol, standardized endoluminal views of the middle ear were generated according to their otological relevance. The HRCT data sets of 26 ENT patients were transferred to a workstation and postprocessed to 52 virtual otoscopies. Generation of predefined endoluminal views from the HRCT data sets was possible in all patients. Virtual endoscopic views added meaningful information to the primary cross-sectional data in patients suffering from ossicular pathology, having contraindications for invasive tympanic endoscopy or being assessed for surgery of the tympanic cavity. Multi slice CT improved the visualization of subtle anatomic details such as the stapes suprastructure and reduced the scanning time. Virtual endoscopy allows for the non invasive endoluminal visualization of various tympanic lesions. Use of the multi-slice CT technique reduces the scanning time and improves image quality in terms of detail resolution.

Surgical anatomy and pathology of the middle ear.

PubMed

Luers, Jan Christoffer; Hüttenbrink, Karl-Bernd

2016-02-01

Middle ear surgery is strongly influenced by anatomical and functional characteristics of the middle ear. The complex anatomy means a challenge for the otosurgeon who moves between preservation or improvement of highly important functions (hearing, balance, facial motion) and eradication of diseases. Of these, perforations of the tympanic membrane, chronic otitis media, tympanosclerosis and cholesteatoma are encountered most often in clinical practice. Modern techniques for reconstruction of the ossicular chain aim for best possible hearing improvement using delicate alloplastic titanium prostheses, but a number of prosthesis-unrelated factors work against this intent. Surgery is always individualized to the case and there is no one-fits-all strategy. Above all, both middle ear diseases and surgery can be associated with a number of complications; the most important ones being hearing deterioration or deafness, dizziness, facial palsy and life-threatening intracranial complications. To minimize risks, a solid knowledge of and respect for neurootologic structures is essential for an otosurgeon who must train him- or herself intensively on temporal bones before performing surgery on a patient. © 2015 Anatomical Society.

Clinical significance of stapedioplasty biomechanics: swimming, diving, flying after stapes surgery.

PubMed

Hüttenbrink, Karl-Bernd

2007-01-01

A piston prosthesis in stapedioplasty significantly modifies the function of the normal ossicular chain. Due to the fact that the ear works as a pressure receptor, a piston prosthesis will be displaced at ambient air pressure changes in a different way than the normal stapes. Our ear is constantly exposed to these pressure changes in daily live, for example during swallowing, with tubal opening, with wind gusts at the external ear, during flying, or diving. Temporal bone experiments showed that elevated static pressures, like in tympanometry, can displace a piston up to 0.5mm in the vestibule. These large movements, which are caused by the missing attachment of the piston to the annual ligament, may explain why a short piston can be lifted out of the footplate perforation (e.g. after sneezing) or a piston with excessive length might come into contact with the membranous labyrinth, causing vertigo with an inward movement. Flying or diving can be performed by the patients after stapedioplasty, provided that a test with tympanometry is tolerated without evoking vertigo.

Ear malformations, hearing loss and hearing rehabilitation in children with Treacher Collins syndrome.

PubMed

Rosa, Francisco; Coutinho, Miguel Bebiano; Ferreira, João Pinto; Sousa, Cecilia Almeida

2016-01-01

The aim of this study was to assess the main ear malformations, hearing loss and auditory rehabilitation in children with Treacher Collins syndrome. We performed a retrospective study of 9 children with Treacher Collins syndrome treated in a central hospital between January 2003 and January 2013. This study showed a high incidence of malformations of the outer and middle ear, such as microtia, atresia or stenosis of the external auditory canal, hypoplastic middle ear cavity, dysmorphic or missing ossicular chain. Most patients had bilateral hearing loss of moderate or high degree. In the individuals studied, there was functional improvement in patients with bone-anchored hearing aids in relation to conventional hearing aids by bone conduction. Treacher Collins syndrome is characterized by bilateral malformations of the outer and middle ear. Hearing rehabilitation in these children is of utmost importance, and bone-anchored hearing aids is the method of choice. Copyright © 2014 Elsevier España, S.L.U. y Sociedad Española de Otorrinolaringología y Cirugía de Cabeza y Cuello. All rights reserved.

The influence of the mechanical behaviour of the middle ear ligaments: a finite element analysis.

PubMed

Gentil, F; Parente, M; Martins, P; Garbe, C; Jorge, R N; Ferreira, A; Tavares, João Manuel R S

2011-01-01

The interest in computer modelling of biomechanical systems, mainly by using the finite element method (FEM), has been increasing, in particular for analysis of the mechanical behaviour of the human ear. In this work, a finite element model of the middle ear was developed to study the dynamic structural response to harmonic vibrations for distinct sound pressure levels applied on the eardrum. The model includes different ligaments and muscle tendons with elastic and hyperelastic behaviour for these supportive structures. Additionally, the nonlinear behaviour of the ligaments and muscle tendons was investigated, as they are the connection between ossicles by contact formulation. Harmonic responses of the umbo and stapes footplate displacements, between 100 Hz and 10 kHz, were obtained and compared with previously published work. The stress state of ligaments (superior, lateral, and anterior of malleus and superior and posterior of incus) was analysed, with the focus on balance of the supportive structures of the middle ear, as ligaments make the link between the ossicular chain and the walls of the tympanic cavity. The results obtained in this work highlight the importance of using hyperelastic models to simulate the mechanical behaviour for the ligaments and tendons.

Computational Modeling of Blast Wave Transmission Through Human Ear.

PubMed

Leckness, Kegan; Nakmali, Don; Gan, Rong Z

2018-03-01

Hearing loss has become the most common disability among veterans. Understanding how blast waves propagate through the human ear is a necessary step in the development of effective hearing protection devices (HPDs). This article presents the first 3D finite element (FE) model of the human ear to simulate blast wave transmission through the ear. The 3D FE model of the human ear consisting of the ear canal, tympanic membrane, ossicular chain, and middle ear cavity was imported into ANSYS Workbench for coupled fluid-structure interaction analysis in the time domain. Blast pressure waveforms recorded external to the ear in human cadaver temporal bone tests were applied at the entrance of the ear canal in the model. The pressure waveforms near the tympanic membrane (TM) in the canal (P1) and behind the TM in the middle ear cavity (P2) were calculated. The model-predicted results were then compared with measured P1 and P2 waveforms recorded in human cadaver ears during blast tests. Results show that the model-derived P1 waveforms were in an agreement with the experimentally recorded waveforms with statistic Kurtosis analysis. The FE model will be used for the evaluation of HPDs in future studies.

Extratympanic observation of middle ear structure using a refractive index matching material (glycerol) and an infrared camera.

PubMed

Kong, Soo-Keun; Chon, Kyong-Myong; Goh, Eui-Kyung; Lee, Il-Woo; Wang, Soo-Geun

2014-05-01

High-resolution computed tomography has been used mainly in the diagnosis of middle ear disease, such as high-jugular bulb, congenital cholesteatoma, and ossicular disruption. However, certain diagnoses are confirmed through exploratory tympanotomy. There are few noninvasive methods available to observe the middle ear. The purpose of this study was to investigate the effect of glycerol as a refractive index matching material and an infrared (IR) camera system for extratympanic observation. 30% glycerol was used as a refractive index matching material in five fresh cadavers. Each material was divided into four subgroups; GN (glycerol no) group, GO (glycerol out) group, GI (glycerol in) group, and GB (glycerol both) group. A printed letter and middle ear structures on the inside tympanic membrane were observed using a visible and IR ray camera system. In the GB group, there were marked a transilluminated letter or an ossicle on the inside tympanic membrane. In particular, a footplate of stapes was even transilluminated using the IR camera system in the GB group. This method can be useful in the diagnosis of diseases of the middle ear if it is clinically applied through further studies.

Extratympanic observation of middle ear structure using a refractive index matching material (glycerol) and an infrared camera

NASA Astrophysics Data System (ADS)

Kong, Soo-Keun; Chon, Kyong-Myong; Goh, Eui-Kyung; Lee, Il-Woo; Wang, Soo-Geun

2014-05-01

High-resolution computed tomography has been used mainly in the diagnosis of middle ear disease, such as high-jugular bulb, congenital cholesteatoma, and ossicular disruption. However, certain diagnoses are confirmed through exploratory tympanotomy. There are few noninvasive methods available to observe the middle ear. The purpose of this study was to investigate the effect of glycerol as a refractive index matching material and an infrared (IR) camera system for extratympanic observation. 30% glycerol was used as a refractive index matching material in five fresh cadavers. Each material was divided into four subgroups; GN (glycerol no) group, GO (glycerol out) group, GI (glycerol in) group, and GB (glycerol both) group. A printed letter and middle ear structures on the inside tympanic membrane were observed using a visible and IR ray camera system. In the GB group, there were marked a transilluminated letter or an ossicle on the inside tympanic membrane. In particular, a footplate of stapes was even transilluminated using the IR camera system in the GB group. This method can be useful in the diagnosis of diseases of the middle ear if it is clinically applied through further studies.

PubMed Central

Labrecque, M; Dostaler, L P; Dumont, H; Huard, G; Laflamme, L

1993-01-01

OBJECTIVE: To determine the interobserver reliability of tympanograms obtained with the MicroTymp, a portable tympanometer. SETTING: Family medicine teaching unit in a tertiary care hospital. PATIENTS: Thirty-three patients who presented to the ear, nose and throat clinic in August 1990 for an ear problem. INTERVENTION: Three residents in family medicine independently attempted to record with the MicroTymp one tympanogram for the 66 ears. We excluded the results for seven ears for which tympanograms could not be obtained. MAIN OUTCOME MEASURE: Using objective criteria, two family physicians and two residents in family medicine independently classified the 177 tympanograms into five categories (normal, possible effusion, possible perforation, possible tympano-ossicular dysfunction and unclassifiable). Reliability was estimated by means of the kappa (kappa) coefficient on 161 tympanograms from 59 ears for which the interpretation of the three tympanograms agreed. MAIN RESULTS: The interpretation of the three tympanograms agreed for 34 of the 59 ears (0.58) (kappa = 0.52, 95% confidence limits 0.45 and 0.59). There was no significant difference in interobserver reliability between pairs of observers or between symptomatic and asymptomatic ears. CONCLUSIONS: The interobserver reliability of the MicroTymp is moderate. The tympanograms obtained with the instrument should be interpreted in the context of the clinical findings. PMID:8431817

Structure and function of the mammalian middle ear. I: Large middle ears in small desert mammals.

PubMed

Mason, Matthew J

2016-02-01

Many species of small desert mammals are known to have expanded auditory bullae. The ears of gerbils and heteromyids have been well described, but much less is known about the middle ear anatomy of other desert mammals. In this study, the middle ears of three gerbils (Meriones, Desmodillus and Gerbillurus), two jerboas (Jaculus) and two sengis (elephant-shrews: Macroscelides and Elephantulus) were examined and compared, using micro-computed tomography and light microscopy. Middle ear cavity expansion has occurred in members of all three groups, apparently in association with an essentially 'freely mobile' ossicular morphology and the development of bony tubes for the middle ear arteries. Cavity expansion can occur in different ways, resulting in different subcavity patterns even between different species of gerbils. Having enlarged middle ear cavities aids low-frequency audition, and several adaptive advantages of low-frequency hearing to small desert mammals have been proposed. However, while Macroscelides was found here to have middle ear cavities so large that together they exceed brain volume, the bullae of Elephantulus are considerably smaller. Why middle ear cavities are enlarged in some desert species but not others remains unclear, but it may relate to microhabitat. © 2015 Anatomical Society.

Ear abnormalities in patients with oculo-auriculo-vertebral spectrum (Goldenhar syndrome).

PubMed

Rosa, Rafael Fabiano Machado; Silva, Alessandra Pawelec da; Goetze, Thayse Bienert; Bier, Bianca de Almeida; Almeida, Sheila Tamanini de; Paskulin, Giorgio Adriano; Zen, Paulo Ricardo Gazzola

2011-01-01

Oculo-auriculo-vertebral spectrum (OAVS) is a rare condition characterized by the involvement of the first branchial arches. To investigate the ear abnormalities of a sample of patients with OAVS. The sample consisted of 12 patients with OAVS seen at the Clinical Genetics Unit, UFCSPA/CHSCPA. The study included only patients who underwent mastoid computed tomography and with normal karyotype. We performed a review of its clinical features, giving emphasis to the ear findings. Nine patients were male, the ages ranged from 1 day to 17 years. Ear abnormalities were observed in all patients and involved the external (n = 12), middle (n = 10) and inner ear (n = 3). Microtia was the most frequent finding (n = 12). The most common abnormalities of the middle ear were: opacification (n = 2), displacement (n = 2) and malformation of the ossicular chain. Agenesis of the internal auditory canal (n = 2) was the most frequent alteration of the inner ear. Ear abnormalities are variable in patients with OAVS and often there is no correlation between findings in the external, middle and inner ear. The evaluation of these structures is important in the management of individuals with OAVS.

Miniature, minimally invasive, tunable endoscope for investigation of the middle ear.

PubMed

Pawlowski, Michal E; Shrestha, Sebina; Park, Jesung; Applegate, Brian E; Oghalai, John S; Tkaczyk, Tomasz S

2015-06-01

We demonstrate a miniature, tunable, minimally invasive endoscope for diagnosis of the auditory system. The probe is designed to sharply image anatomical details of the middle ear without the need for physically adjusting the position of the distal end of the endoscope. This is achieved through the addition of an electrowetted, tunable, electronically-controlled lens to the optical train. Morphological imaging is enabled by scanning light emanating from an optical coherence tomography system. System performance was demonstrated by imaging part of the ossicular chain and wall of the middle ear cavity of a normal mouse. During the experiment, we electronically moved the plane of best focus from the incudo-stapedial joint to the stapedial artery. Repositioning the object plane allowed us to image anatomical details of the middle ear beyond the depth of field of a static optical system. We also demonstrated for the first time to our best knowledge, that an optical system with an electrowetted, tunable lens may be successfully employed to measure sound-induced vibrations within the auditory system by measuring the vibratory amplitude of the tympanic membrane in a normal mouse in response to pure tone stimuli.

Influence of Ossicular Chain Damage on Hearing After Chronic Otitis Media and Cholesteatoma Surgery: A Systematic Review and Meta-analysis.

PubMed

Blom, Erik F; Gunning, Marlise N; Kleinrensink, Nienke J; Lokin, Alexander S H J; Bruijnzeel, Hanneke; Smit, Adriana L; Grolman, Wilko

2015-11-01

Physicians should ideally be able to provide patients with chronic otitis media and/or cholesteatoma specific information about postoperative hearing outcome, based on their level of preoperative ossicular chain damage (OCD). To identify the influence of preoperative OCD on hearing outcomes in patients after chronic otitis media and/or cholesteatoma surgery. PubMed, EMBASE, and the Cochrane Library databases were systematically searched for available evidence, without any constraints, on December 13, 2014, for articles published between January 1, 1975, and December 13, 2014. We reviewed the literature for articles assessing the prognostic value of OCD on postoperative hearing outcome (air-bone gap [ABG] in decibels), using Austin-Kartush criteria or independent OCD classification systems. We assessed relevance and validity using a self-designed critical appraisal tool based on the Cochrane Collaboration's risk of bias tool. Characteristics of study populations and postoperative ABGs in decibels were extracted from all included studies by 4 authors (E.F.B., M.N.G., N.J.K., A.S.H.J.L.). The tested hypothesis was formulated before data collection. Primary study outcome was defined as postoperative adult hearing outcomes after COM and/or cholesteatoma surgery defined as mean postoperative ABG. Our search yielded 5661 articles. Nine articles with high relevance were included. Pooled results of studies using the Austin-Kartush criteria showed a significant (P < .001) difference in mean ABG in favor of group B, when comparing group B (patients with malleus present, stapes absent; 11.1 [95% CI, 10.3-11.8] dB) to group C (patients with malleus absent, stapes present; 15.7 [95% CI, 14.6-16.7] dB) and group B to group D (patients with malleus absent, stapes absent; 16.5 [95% CI, 15.2-17.9] dB). Three studies using independent OCD classification criteria found no influence of stapes structure (intact stapes suprastructure, 13.5 [95% CI, 10.3-16.7], 15.1 [95% CI, 11.8-18.3], and 21.9 [95% CI, 15.0-28.8] dB vs absent stapes structure, 12.8 [95% CI, 9.5-16.1], 19.5 [95% CI, 14.9-24.1], and 30.2 [95% CI, 24.7-35.8] dB) on postoperative ABG. One study reported a significant (P = .04) difference in mean ABG between patients with present (18.9 [95% CI, 15.7-22.1] dB) and absent (24.4 [95% CI, 20.2-28.6] dB) malleus. Pooled results of Austin-Kartush studies showed that in patients with COM, with or without cholesteatoma, the malleus status is a significant predictor of postoperative hearing outcome, independent of the stapes condition. Studies reporting on individual ossicle status supported this finding by showing that only malleus condition influenced postoperative hearing outcome. These findings are based on level IV evidence, which indicates the need for future high-level evidence studies.

Development of a finite element model of the middle ear.

PubMed

Williams, K R; Blayney, A W; Rice, H J

1996-01-01

A representative finite element model of the healthy ear is developed commencing with a description of the decoupled isotropic tympanic membrane. This model was shown to vibrate in a manner similar to that found both numerically (1, 2) and experimentally (8). The introduction of a fibre system into the membrane matrix significantly altered the modes of vibration. The first mode "remains as a piston like movement as for the isotropic membrane. However, higher modes show a simpler vibration pattern similar to the second mode but with a varying axis of movement and lower amplitudes. The introduction of a malleus and incus does not change the natural frequencies or mode shapes of the membrane for certain support conditions. When constraints are imposed along the ossicular chain by simulation of a cochlear impedance term then significantly altered modes can occur. More recently a revised model of the ear has been developed by the inclusion of the outer ear canal. This discretisation uses geometries extracted from a Nuclear Magnetic resonance scan of a healthy subject and a crude inner ear model using stiffness parameters ultimately fixed through a parameter tuning process. The subsequently tuned model showed behaviour consistent with previous findings and should provide a good basis for subsequent modelling of diseased ears and assessment of the performance of middle ear prostheses.

A case of chronic otitis media caused by Mycobacterium abscessus.

PubMed

Sugimoto, Hisashi; Ito, Makoto; Hatano, Miyako; Nakanishi, Yosuke; Maruyama, Yumiko; Yoshizaki, Tomokazu

2010-10-01

Although it appears very uncommon in adult COM, Mycobacterium abscessus should be considered as a possible cause of a chronically draining ear. Multi-antibiotic chemotherapy including high-dose clarithromycin can effectively treat adult COM cased by M. abscessus. The first case report of adult chronic otitis media (COM) caused by M. abscessus is described here. A 61-year-old woman presented persistent otorrhea for 2 months, despite treatment with standard antimicrobial drugs. Physical examination revealed a small perforation of the tympanic membrane and edematous middle ear mucosa. Mycobacterial cultures and PCR yielded non-tuberculous mycobacteria (NTM); M. abscessus. Intravenous panipenem/betamipron and amikacin and oral clarithromycin were administered for 36 days. Computed tomography of the temporal bone showed improved aeration in the tympanic cavity, but soft tissue shadow remained unchanged in the mastoid 31 days after starting medication. She therefore underwent tympano-mastoidectomy at 36 days. At surgery, inflammation remained in the middle ear, and edematous pale mucosal tissue was noted around the stapes and ossicular chain. Histopathologic examination showed inflammation and granulation tissue, but no caseating necrosis or acid-fast bacilli. After surgery the symptoms resolved and remained well without evidence of infection recurrence 12 months after the operation. Copyright 2010 Elsevier Ireland Ltd. All rights reserved.

A short-wave infrared otoscope for middle ear disease diagnostics (Conference Presentation)

NASA Astrophysics Data System (ADS)

Carr, Jessica A.; Valdez, Tulio; Bruns, Oliver; Bawendi, Moungi

2016-02-01

Otitis media, a range of inflammatory conditions of the middle ear, is the second most common illness diagnosed in children. However, the diagnosis can be challenging, particularly in pediatric patients. Otitis media is commonly over-diagnosed and over-treated and has been identified as one of the primary factors in increased antibiotic resistance. We describe the development of a short-wave infrared (SWIR) otoscope for objective middle ear effusion diagnosis. The SWIR otoscope can unambiguously detect the presence of middle ear fluid based on its strong light absorption in the SWIR. This absorption causes a stark, visual contrast between the presence and absence of fluid behind the tympanic membrane. Additionally, when there is no middle ear fluid, the deeper tissue penetration of SWIR light allows the SWIR otoscope to better visualize middle ear anatomy through the tympanic membrane than is possible with visible light. We demonstrate that in healthy, adult human ears, SWIR otoscopy can image a range of middle ear anatomy, including landmarks of the entire ossicular chain, the promontory, the round window niche, and the chorda tympani. We suggest that SWIR otoscopy can provide valuable diagnostic information complementary to that provided by visible pneumotoscopy in the diagnosis of middle ear effusions, otitis media, and other maladies of the middle ear.

Ground sounds: Seismic detection in the golden mole

NASA Astrophysics Data System (ADS)

Narins, Peter M.; Lewis, Edwin R.

2004-05-01

The Namib Desert golden mole is a nocturnal, surface-foraging mammal, possessing a massively hypertrophied malleus which presumably confers low-frequency, substrate-vibration sensitivity through inertial bone conduction. Foraging trails are punctuated with characteristic sand disturbances in which the animal's head dips under the sand. The function of this behavior is not known but it is thought that it may be used to obtain a seismic fix on the next mound to be visited. To test this, we measured the local seismic vibrations both on the top of a mound and on the flats. The spectrum recorded on the flats shows a relatively low-amplitude peak at about 120 Hz, whereas the spectral peak recorded from the mound is nearly 17 dB greater in amplitude and centered at 310 Hz. This suggests that mounds act as seismic beacons for the golden moles that would be detectable from distances corresponding to typical intermound distances of 20-25 m. In addition, out of the 117 species for which data are available, these golden moles have the greatest ossicular mass relative to body size (Mason, personal communication). Functionally, they appear to be low-frequency specialists, and it is likely that golden moles hear through substrate conduction. [Work supported by NIH.

Medical devices of the head, neck, and spine.

PubMed

Hunter, Tim B; Yoshino, Mark T; Dzioba, Robert B; Light, Rick A; Berger, William G

2004-01-01

There are many medical devices used for head, neck, and spinal diseases and injuries, and new devices are constantly being introduced. Many of the newest devices are variations on a previous theme. Knowing the specific name of a device is not important. It is important to recognize the presence of a device and to have an understanding of its function as well as to be able to recognize the complications associated with its use. The article discusses the most common and important devices of the head, neck, and spine, including cerebrospinal fluid shunts and the Codman Hakim programmable valve; subdural drainage catheters, subdural electrodes, intracranial electrodes, deep brain stimulators, and cerebellar electrodes; coils, balloons, adhesives, particles, and aneurysm clips; radiation therapy catheters, intracranial balloons for drug installation, and carmustine wafers; hearing aids, cochlear implants, and ossicular reconstruction prostheses; orbital prostheses, intraocular silicone oil, and lacrimal duct stents; anterior and posterior cervical plates, posterior cervical spine wiring, odontoid fracture fixation devices, cervical collars and halo vests; thoracic and lumbar spine implants, anterior and posterior instrumentation for the thoracic and lumbar spine, vertebroplasty, and artificial disks; spinal column stimulators, bone stimulators, intrathecal drug delivery pumps, and sacral stimulators; dental and facial implant devices; gastric and tracheal tubes; vagus nerve stimulators; lumboperitoneal shunts; and temperature- and oxygen-sensing probes. Copyright RSNA, 2004

Pressurized transient otoacoustic emissions measured using click and chirp stimuli.

PubMed

Keefe, Douglas H; Patrick Feeney, M; Hunter, Lisa L; Fitzpatrick, Denis F; Sanford, Chris A

2018-01-01

Transient-evoked otoacoustic emission (TEOAE) responses were measured in normal-hearing adult ears over frequencies from 0.7 to 8 kHz, and analyzed with reflectance/admittance data to measure absorbed sound power and the tympanometric peak pressure (TPP). The mean TPP was close to ambient. TEOAEs were measured in the ear canal at ambient pressure, TPP, and fixed air pressures from 150 to -200 daPa. Both click and chirp stimuli were used to elicit TEOAEs, in which the incident sound pressure level was constant across frequency. TEOAE levels were similar at ambient and TPP, and for frequencies from 0.7 to 2.8 kHz decreased with increasing positive and negative pressures. At 4-8 kHz, TEOAE levels were larger at positive pressures. This asymmetry is possibly related to changes in mechanical transmission through the ossicular chain. The mean TEOAE group delay did not change with pressure, although small changes were observed in the mean instantaneous frequency and group spread. Chirp TEOAEs measured in an adult ear with Eustachian tube dysfunction and TPP of -165 daPa were more robust at TPP than at ambient. Overall, results demonstrate the feasibility and clinical potential of measuring TEOAEs at fixed pressures in the ear canal, which provide additional information relative to TEOAEs measured at ambient pressure.

Thyroid Hormone Receptors Control Developmental Maturation of the Middle Ear and the Size of the Ossicular Bones

PubMed Central

Cordas, Emily A.; Ng, Lily; Hernandez, Arturo; Kaneshige, Masahiro; Cheng, Sheue-Yann

2012-01-01

Thyroid hormone is critical for auditory development and has well-known actions in the inner ear. However, less is known of thyroid hormone functions in the middle ear, which contains the ossicles (malleus, incus, stapes) that relay mechanical sound vibrations from the outer ear to the inner ear. During the later stages of middle ear development, prior to the onset of hearing, middle ear cavitation occurs, involving clearance of mesenchyme from the middle ear cavity while the immature cartilaginous ossicles attain appropriate size and ossify. Using in situ hybridization, we detected expression of Thra and Thrb genes encoding thyroid hormone receptors α1 and β (TRα1 and TRβ, respectively) in the immature ossicles, surrounding mesenchyme and tympanic membrane in the mouse. Thra+/PV mice that express a dominant-negative TRα1 protein exhibited deafness with elevated auditory thresholds and a range of middle ear abnormalities including chronic persistence of mesenchyme in the middle ear into adulthood, markedly enlarged ossicles, and delayed ossification of the ossicles. Congenitally hypothyroid Tshr−/− mice and TR-deficient Thra1−/−;Thrb−/− mice displayed similar abnormalities. These findings demonstrate that middle ear maturation is TR dependent and suggest that the middle ear is a sensitive target for thyroid hormone in development. PMID:22253431

Limits on normal cochlear 'third' windows provided by previous investigations of additional sound paths into and out of the cat inner ear.

PubMed

Rosowski, John J; Bowers, Peter; Nakajima, Hideko H

2018-03-01

While most models of cochlear function assume the presence of only two windows into the mammalian cochlea (the oval and round windows), a position that is generally supported by several lines of data, there is evidence for additional sound paths into and out of the inner ear in normal mammals. In this report we review the existing evidence for and against the 'two-window' hypothesis. We then determine how existing data and inner-ear anatomy restrict transmission of sound through these additional sound pathways in cat by utilizing a well-tested model of the cat inner ear, together with anatomical descriptions of the cat cochlear and vestibular aqueducts (potential additional windows to the cochlea). We conclude: (1) The existing data place limits on the size of the cochlear and vestibular aqueducts in cat and are consistent with small volume-velocities through these ducts during ossicular stimulation of the cochlea, (2) the predicted volume velocities produced by aqueducts with diameters half the size of the bony diameters match the functional data within ±10 dB, and (3) these additional volume velocity paths contribute to the inner ear's response to non-acoustic stimulation and conductive pathology. Copyright © 2017 Elsevier B.V. All rights reserved.

Simultaneous Measurements of Ossicular Velocity and Intracochlear Pressure Leading to the Cochlear Input Impedance in Gerbil

PubMed Central

Decraemer, W. F.; Khanna, S. M.; Olson, E. S.

2008-01-01

Recent measurements of three-dimensional stapes motion in gerbil indicated that the piston component of stapes motion was the primary contributor to intracochlear pressure. In order to make a detailed correlation between stapes piston motion and intracochlear pressure behind the stapes, simultaneous pressure and motion measurements were undertaken. We found that the scala vestibuli pressure followed the piston component of the stapes velocity with high fidelity, reinforcing our previous finding that the piston motion of the stapes was the main stimulus to the cochlea. The present data allowed us to calculate cochlear input impedance and power flow into the cochlea. Both the amplitude and phase of the impedance were quite flat with frequency from 3 kHz to at least 30 kHz, with a phase that was primarily resistive. With constant stimulus pressure in the ear canal the intracochlear pressure at the stapes has been previously shown to be approximately flat with frequency through a wide range, and coupling that result with the present findings indicates that the power that flows into the cochlea is quite flat from about 3 to 30 kHz. The observed wide-band intracochlear pressure and power flow are consistent with the wide-band audiogram of the gerbil. PMID:18459001

Anatomic Malformations of the Middle and Inner Ear in 22q11.2 Deletion Syndrome: Case Series and Literature Review.

PubMed

Verheij, E; Elden, L; Crowley, T B; Pameijer, F A; Zackai, E H; McDonald-McGinn, D M; Thomeer, H G X M

2018-05-01

The 22q11.2 deletion syndrome is characterized by a heterogenic phenotype, including hearing loss. The underlying cause of hearing loss, especially sensorineural hearing loss, is not yet clear. Therefore, our objective was to describe anatomic malformations in the middle and inner ear in patients with 22q11.2 deletion syndrome. A retrospective case series was conducted in 2 tertiary referral centers. All patients with 22q11.2 deletion syndrome who had undergone CT or MR imaging of the temporal bones were included. Radiologic images were evaluated on predetermined parameters, including abnormalities of the ossicular chain, cochlea, semicircular canals, and vestibule. There were 26 patients (52 ears) with a CT or MR imaging scan available. A dense stapes superstructure was found in 18 ears (36%), an incomplete partition type II was suspected in 12 cochleas (23%), the lateral semicircular canal was malformed with a small bony island in 17 ears (33%), and the lateral semicircular canal and vestibule were fused to a single cavity in 15 ears (29%). Middle and inner ear abnormalities were frequently encountered in our cohort, including malformations of the lateral semicircular canal. © 2018 by American Journal of Neuroradiology.

Cochlear Implantation in Patients With CHARGE Syndrome.

PubMed

Rah, Yoon Chan; Lee, Ji Young; Suh, Myung-Whan; Park, Moo Kyun; Lee, Jun Ho; Chang, Sun O; Oh, Seung-Ha

2016-11-01

To determine the optimal surgical approach for cochlear implantation (CI) preoperatively based on the spatial relation of a displaced facial nerve (FN) and middle ear structures and to analyze clinical outcomes of CHARGE syndrome. Facial nerve displacement and associated deviation of inner ear structures were analyzed in 13 patients (17 ears) with CHARGE syndrome who underwent CI. Surgical accessibility through the facial recess was assessed based on anatomical landmarks. Postoperative speech performance and associated clinical characteristics were analyzed. The most consistently identified ear anomalies were semicircular canal aplasia (100%), ossicular anomaly (100%), and vestibular hypoplasia (88%). Facial nerve displacement was found in 77% of cases (anteroinferior: 47%, anterior: 24%, inferior: 6%). The width of available surgical space around facial recess was significantly greater in cases of facial recess approach (2.85 ± 0.9 mm) than those of alternative approach (0.12 ± 0.29 mm, P = .02). Postoperatively, 53% achieved better than category 4 on the categories of auditory perception (CAP) scale. The CAP category was significantly correlated with internal auditory canal diameter (P = .025) and did not differ according to the applied surgical approach. Preoperative determination of surgical accessibility through facial recess would be useful for safe surgical approach, and successful hearing rehabilitation was achievable by applying appropriate surgical approaches. © The Author(s) 2016.

Measurement of the Three-Dimensional Vibration Motion of the Ossicular Chain in the Living Gerbil

NASA Astrophysics Data System (ADS)

Decraemer, Willem F.; de La Rochefoucauld, Ombeline; Olson, Elizabeth S.

2011-11-01

In previous studies 3D motion of the middle-ear ossicles in cat and human temporal bone were explored but models for hearing research has shifted in the last decades to smaller mammals and gerbil in particular has become a hearing model of first choice. In the present study we have measured with an optical interferometer the 3D motion of the malleus and incus in anesthetized gerbil for sound of moderate intensity (90 dB SPL) in a broad frequency range. To access the malleus and incus the pars flaccida was completely removed exposing the neck and head of the malleus and the incus from the malleus-incus joint to the long process of the incus and the plate of the lenticular process. In a previous study an approach through a hole in the bullar wall was used to study the stapes motion so that we now have a complete picture of the middle ear motion. In both approaches vibration measurements were done at 6 to 7 points per ossicle while the angle of observation was varied over approximately 30 degrees to enable calculation of the 3D velocity components. Knowledge of middle ear motion is of great importance in understanding how the middle ear transforms the acoustical input from the ear canal to the cochlea.

Roles of an anti-tuberculosis medication and surgery in patients with tuberculous otitis media.

PubMed

Kwon, Minsu; Choi, Seung Hyo; Chung, Jong Woo

2010-06-01

The standard treatment for tuberculous otitis media (TOM) without complications consists of anti-tuberculosis (anti-TB) medication, with which we experienced good treatment outcomes. However, surgery is required for recovery of anatomy and hearing function. To determine the clinical characteristics of TOM that might optimize diagnosis and to evaluate the differences in clinical courses between patients treated with and without surgery. We analyzed 14 patients (16 ears) who had been diagnosed and treated for TOM. Radiologic findings, laboratory data, and audiometry results were also evaluated. Patients were divided into a chemotherapy group and a surgery group according to treatment modality. Temporal bone CT (TBCT) showed total occupation of the tympanic cavity by soft tissue and little evidence of ossicular erosion. In the chemotherapy group, dry ears were obtained in all but one patient (14 ears) after treatment. Normalized tympanic membrane (TM) was found in 50% in the chemotherapy group and in 75% in the surgery group. The air-bone gap (ABG) changed from 40.3 +/- 2.5 dB to 47.0 +/- 19.2 dB in the chemotherapy group and from 35.2 +/- 7.6 dB to 30.2 +/- 11.4 dB in the surgery group. After treatment, ABG improved by > 10 dB in one ear in the chemotherapy group and in four ears in the surgery group.

Examining in vivo tympanic membrane mobility using smart phone video-otoscopy and phase-based Eulerian video magnification

NASA Astrophysics Data System (ADS)

Janatka, Mirek; Ramdoo, Krishan S.; Tatla, Taran; Pachtrachai, Krittin; Elson, Daniel S.; Stoyanov, Danail

2017-03-01

The tympanic membrane (TM) is the bridging element between the pressure waves of sound in air and the ossicular chain. It allows for sound to be conducted into the inner ear, achieving the human sense of hearing. Otitis media with effusion (OME, commonly referred to as `glue ear') is a typical condition in infants that prevents the vibration of the TM and causes conductive hearing loss, this can lead to stunting early stage development if undiagnosed. Furthermore, OME is hard to identify in this age group; as they cannot respond to typical audiometry tests. Tympanometry allows for the mobility of the TM to be examined without patient response, but requires expensive apparatus and specialist training. By combining a smartphone equipped with a 240 frames per second video recording capability with an otoscopic clip-on accessory, this paper presents a novel application of Eulerian Video Magnification (EVM) to video-otology, that could provide assistance in diagnosing OME. We present preliminary results showing a spatio-temporal slice taken from an exaggerated video visualization of the TM being excited in vivo on a healthy ear. Our preliminary results demonstrate the potential for using such an approach for diagnosing OME under visual inspection as alternative to tympanometry, which could be used remotely and hence help diagnosis in a wider population pool.

Mandibulofacial Dysostosis with Microcephaly: Mutation and Database Update

PubMed Central

Huang, Lijia; Vanstone, Megan R.; Hartley, Taila; Osmond, Matthew; Barrowman, Nick; Allanson, Judith; Baker, Laura; Dabir, Tabib A.; Dipple, Katrina M.; Dobyns, William B.; Estrella, Jane; Faghfoury, Hanna; Favaro, Francine P.; Goel, Himanshu; Gregersen, Pernille A.; Gripp, Karen W.; Grix, Art; Guion-Almeida, Maria-Leine; Harr, Margaret H.; Hudson, Cindy; Hunter, Alasdair G.W.; Johnson, John; Joss, Shelagh K.; Kimball, Amy; Kini, Usha; Kline, Antonie D.; Lauzon, Julie; Lildballe, Dorte L.; López-González, Vanesa; Martinezmoles, Johanna; Meldrum, Cliff; Mirzaa, Ghayda M.; Morel, Chantal F.; Morton, Jenny E.V.; Pyle, Louise C.; Quintero-Rivera, Fabiola; Richer, Julie; Scheuerle, Angela E.; Schönewolf-Greulich, Bitten; Shears, Deborah J.; Silver, Josh; Smith, Amanda C.; Temple, I. Karen; van de Kamp, Jiddeke M.; van Dijk, Fleur S.; Vandersteen, Anthony M.; White, Sue M.; Zackai, Elaine H.; Zou, Ruobing; Bulman, Dennis E.; Boycott, Kym M.; Lines, Matthew A.

2017-01-01

Mandibulofacial dysostosis with microcephaly (MFDM) is a multiple malformation syndrome comprising microcephaly, craniofacial anomalies, hearing loss, dysmorphic features, and, in some cases, esophageal atresia. Haploinsufficiency of a spliceosomal GTPase, U5–116 kDa/EFTUD2, is responsible. Here, we review the molecular basis of MFDM in the 69 individuals described to date, and report mutations in 38 new individuals, bringing the total number of reported individuals to 107 individuals from 94 kindreds. Pathogenic EFTUD2 variants comprise 76 distinct mutations and seven microdeletions. Among point mutations, missense substitutions are infrequent (14 out of 76; 18%) relative to stop-gain (29 out of 76; 38%), and splicing (33 out of 76; 43%) mutations. Where known, mutation origin was de novo in 48 out of 64 individuals (75%), dominantly inherited in 12 out of 64 (19%), and due to proven germline mosaicism in four out of 64 (6%). Highly penetrant clinical features include, microcephaly, first and second arch craniofacial malformations, and hearing loss; esophageal atresia is present in an estimated ~27%. Microcephaly is virtually universal in childhood, with some adults exhibiting late “catch-up” growth and normocephaly at maturity. Occasionally reported anomalies, include vestibular and ossicular malformations, reduced mouth opening, atrophy of cerebral white matter, structural brain malformations, and epibulbar dermoid. All reported EFTUD2 mutations can be found in the EFTUD2 mutation database (http://databases.lovd.nl/shared/genes/EFTUD2). PMID:26507355

Mandibulofacial Dysostosis with Microcephaly: Mutation and Database Update.

PubMed

Huang, Lijia; Vanstone, Megan R; Hartley, Taila; Osmond, Matthew; Barrowman, Nick; Allanson, Judith; Baker, Laura; Dabir, Tabib A; Dipple, Katrina M; Dobyns, William B; Estrella, Jane; Faghfoury, Hanna; Favaro, Francine P; Goel, Himanshu; Gregersen, Pernille A; Gripp, Karen W; Grix, Art; Guion-Almeida, Maria-Leine; Harr, Margaret H; Hudson, Cindy; Hunter, Alasdair G W; Johnson, John; Joss, Shelagh K; Kimball, Amy; Kini, Usha; Kline, Antonie D; Lauzon, Julie; Lildballe, Dorte L; López-González, Vanesa; Martinezmoles, Johanna; Meldrum, Cliff; Mirzaa, Ghayda M; Morel, Chantal F; Morton, Jenny E V; Pyle, Louise C; Quintero-Rivera, Fabiola; Richer, Julie; Scheuerle, Angela E; Schönewolf-Greulich, Bitten; Shears, Deborah J; Silver, Josh; Smith, Amanda C; Temple, I Karen; van de Kamp, Jiddeke M; van Dijk, Fleur S; Vandersteen, Anthony M; White, Sue M; Zackai, Elaine H; Zou, Ruobing; Bulman, Dennis E; Boycott, Kym M; Lines, Matthew A

2016-02-01

Mandibulofacial dysostosis with microcephaly (MFDM) is a multiple malformation syndrome comprising microcephaly, craniofacial anomalies, hearing loss, dysmorphic features, and, in some cases, esophageal atresia. Haploinsufficiency of a spliceosomal GTPase, U5-116 kDa/EFTUD2, is responsible. Here, we review the molecular basis of MFDM in the 69 individuals described to date, and report mutations in 38 new individuals, bringing the total number of reported individuals to 107 individuals from 94 kindreds. Pathogenic EFTUD2 variants comprise 76 distinct mutations and seven microdeletions. Among point mutations, missense substitutions are infrequent (14 out of 76; 18%) relative to stop-gain (29 out of 76; 38%), and splicing (33 out of 76; 43%) mutations. Where known, mutation origin was de novo in 48 out of 64 individuals (75%), dominantly inherited in 12 out of 64 (19%), and due to proven germline mosaicism in four out of 64 (6%). Highly penetrant clinical features include, microcephaly, first and second arch craniofacial malformations, and hearing loss; esophageal atresia is present in an estimated ∼27%. Microcephaly is virtually universal in childhood, with some adults exhibiting late "catch-up" growth and normocephaly at maturity. Occasionally reported anomalies, include vestibular and ossicular malformations, reduced mouth opening, atrophy of cerebral white matter, structural brain malformations, and epibulbar dermoid. All reported EFTUD2 mutations can be found in the EFTUD2 mutation database (http://databases.lovd.nl/shared/genes/EFTUD2). © 2015 WILEY PERIODICALS, INC.

Development of wide-band middle ear transmission in the Mongolian gerbil

NASA Astrophysics Data System (ADS)

Overstreet, Edward H.; Ruggero, Mario A.

2002-01-01

Stapes vibrations were measured in deeply anesthetized adult and neonatal (ages: 14 to 20 days) Mongolian gerbils. In adult gerbils, the velocity magnitude of stapes responses to tones was approximately constant over the entire frequency range of measurements, 1 to 40 kHz. Response phases referred to pressure near the tympanic membrane varied approximately linearly as a function of increasing stimulus frequency, with a slope corresponding to a group delay of 30 μs. In neonatal gerbils, the sensitivity of stapes responses to tones was lower than in adults, especially at mid-frequencies (e.g., by about 15 dB at 10-20 kHz in gerbils aged 14 days). The input impedance of the adult gerbil cochlea, calculated from stapes vibrations and published measurements of pressure in scala vestibuli near the oval window [E. Olson, J. Acoust. Soc. Am. 103, 3445-3463 (1998)], is principally dissipative at frequencies lower than 10 kHz. Conclusions: (a) middle-ear vibrations in adult gerbils do not limit the input to the cochlea up to at least 40 kHz, i.e., within 0.5 oct of the high-frequency cutoff of the behavioral audiogram; and (b) the results in both adult and neonatal gerbils are inconsistent with the hypothesis that mass reactance controls high-frequency ossicular vibrations and support the idea that the middle ear functions as a transmission line.

Otologic manifestations of Larsen syndrome.

PubMed

Marques, Letícia Helena de Sousa; Martins, Daniela Vieira; Juares, Gabriel Liria; Lorenzetti, Fábio Tadeu Moura; Monsanto, Rafael da Costa

2017-10-01

To describe and discuss otologic manifestations of Larsen syndrome, based on a case report and a systematic review of the literature. We performed a PubMED database search, and we selected studies reporting otolaryngologic manifestations secondary to Larsen syndrome. The selected articles were read in full, and three researchers independently extracted data from the studies. In parallel, we report the case of a 14-year-old patient who had hearing loss secondary to Larsen syndrome. Fifteen studies met our selection criteria. Seven studies reported hearing loss in patients with Larsen syndrome (4 had conductive hearing loss and 3 had mixed hearing loss). The conductive hearing loss may be secondary to ossicular malformations and/or middle ear effusions. Other causes for conductive hearing loss are mesenchymal remnants in the middle ear, Eustachian tube dysfunction, and cleft palate. Surgical management of the hearing loss is possible in selected cases, although the surgical and anesthetic risks should be considered. Hearing aids seem to be safe and effective treatment options for the hearing loss secondary to Larsen syndrome. Although rare, patients with Larsen syndrome may have hearing loss. The most frequent type of deficit is conductive, either secondary to malformation of the ossicles or middle ear effusion. Possible surgical correction of these abnormalities should be weighed against the anesthetic risks of these patients. Copyright © 2017 Elsevier B.V. All rights reserved.

Stage progression of congenital cholesteatoma in children.

PubMed

Kim, Young Ho; Yoo, Jae Chul; Lee, Jun Ho; Oh, Seung-Ha; Chang, Sun O; Koo, Ja-Won; Kim, Chong Sun

2012-03-01

This study aimed to investigate the most prevalent stage in each age-group of children with congenital cholesteatoma (CC) and verify the correlation between the stage and the age of the patients for the type of CC ("closed" keratotic cyst and "open" infiltrative types). Patients diagnosed with CC between 2004 and 2009 (n = 156; 116 boys and 40 girls; mean age, 5 years and 5 months; range, 12 months-16 years and 7 months) were enrolled retrospectively. Assessment of stage and type of CC was performed with preoperative high-resolution temporal bone computed tomography and intraoperative findings. The stage of CC was determined using Potsic's staging system classified into four stages according to ossicular involvement and mastoid extension. The patients consisted of groups divided on the basis of a 2-year interval. The prevalence of stage I began to decline from the age-group of 1-2 years. In contrast, the prevalence of stages III increased from the age-group of 3-4 years and that of stage IV from the age-group 5-6 years. The prevalence of "open" infiltrative type CC increased from approximately the age of 7 years, thus showing some correlation with age but not with stage. The prevalence of CC with the advanced stage increased since the age of 2 years. Therefore, the importance of early diagnosis and treatment of CC should be more emphasized.

Hearing and whistling in the deep sea: depth influences whistle spectra but does not attenuate hearing by white whales (Delphinapterus leucas) (Odontoceti, Cetacea).

PubMed

Ridgway, S H; Carder, D A; Kamolnick, T; Smith, R R; Schlundt, C E; Elsberry, W R

2001-11-01

Hearing is attenuated in the aerial ear of humans and other land mammals tested in pressure chambers as a result of middle ear impedance changes that result from increased air density. We tested the hypothesis, based on recent middle ear models, that increasing the density of middle ear air at depth might attenuate whale hearing. Two white whales Delphinapterus leucas made dives to a platform at a depth of 5, 100, 200 or 300 m in the Pacific Ocean. During dives to station on the platform for up to 12 min, the whales whistled in response to 500 ms tones projected at random intervals to assess their hearing threshold at each depth. Analysis of response whistle spectra, whistle latency in response to tones and hearing thresholds showed that the increased hydrostatic pressure at depth changed each whale's whistle response at depth, but did not attenuate hearing overall. The finding that whale hearing is not attenuated at depth suggests that sound is conducted through the head tissues of the whale to the ear without requiring the usual ear drum/ossicular chain amplification of the aerial middle ear. These first ever hearing tests in the open ocean demonstrate that zones of audibility for human-made sounds are just as great throughout the depths to which these whales dive, or at least down to 300 m.

Assessment and management of retraction pockets.

PubMed

Alper, Cuneyt; Olszewska, Ewa

2017-02-28

This manuscript intends to review types, pathogenesis, associated risk factors, and potential methods of prevention and treatment of the retraction pockets in adults and children. The importance of retraction pockets (RP) lies in loss of original histological and anatomical structure which is associated with development of ossicular chain erosion, cho¬lesteatoma formation and potentially life threatening complications of cholesteatoma. The trans-mucosal exchange each gas in the middle ear (ME) is towards equalizing its partial pressures with the partial pressure in the environ¬ment. MEs that have abnormalities in the volume and ventilation pathways in the epitympanic may be more suscep¬tible to retraction pockets. Sustained pressure differences and/or inflammation leads to destruction of collagen fibers in the lamina propria. Inflammatory mediators and cytokines lead to release of collagenases result in viscoelastic properties of the lamina propria. The process of changes in the tympanic membrane structure may evolve to the cho¬lesteatoma formation. There are many different staging systems that clinicians prioritize in their decision making in the management of RP. The authors discuss the management possibilities in different clinical situations: RP without and with ongoing or intermittent evidence of Eustachian Tube Dysfunction (ETD), presence of adenoid hypertrophy or re-growth of adenoids, presence or absence of effusion, invisible depth of RP without effusion. invisible depth of RP with effusion, ongoing RP after VT insertion, and finally suspicion of cholesteatoma in a deep RP with ME effusion. A decision algorithm regarding the management of TM retraction and retraction pockets is provided.

[How do metallic middle ear implants behave in the MRI?].

PubMed

Kwok, P; Waldeck, A; Strutz, J

2003-01-01

Magnetic resonance imaging (MRI) has gained in frequency and importance as a diagnostic procedure. In respect to the close anatomical relationship in the temporal bone it is necessary to know whether it is hazardous to patients with metallic middle ear implants regarding displacement and rise in temperature. For the MR image quality artefacts caused by metallic prostheses should be low. Four different stapes prostheses made from titanium, gold, teflon/platinum and teflon/steel, a titanium total ossicular reconstruction prosthesis (TORP) and two ventilation tubes (made from titanium and gold) were tested in a 1.5 Tesla MRI machine regarding their displacement. All objects were first placed in a petri dish, then suspended from a thread and finally immersed in a dish filled with Gadolinium. Temperature changes of the implants were recorded by a pyrometer. None of the implants moved when they were placed in the petri dish or suspended from the thread. On the water surface the teflon/platinum and the teflon/steel pistons adjusted their direction with their axis longitudinally to the MRI scanner opening and the teflon/steel piston floated towards the MRI-machine when put close enough to the scanner opening. No rise in temperature was recorded. All implants showed as little artefacts that would still make an evaluation of the surrounding tissue possible. Patients with any of the metallic middle ear implants that were examined in this study may undergo MRI-investigations without significant adverse effects.

Electromagnetic semi-implantable hearing device: phase I. Clinical trials.

PubMed

McGee, T M; Kartush, J M; Heide, J C; Bojrab, D I; Clemis, J D; Kulick, K C

1991-04-01

Conventional hearing aids have improved significantly in recent years; however, amplification of sound within the external auditory canal creates a number of intrinsic problems, including acoustic feedback and the need for a tight ear mold to increase usable gain. Nonacoustic alternatives which could obviate these encumbrances have not become practical due to inefficient coupling (piezoelectric techniques) or unfeasible power requirements (electromagnetic techniques). Recent technical advances, however, prompted a major clinical investigation of a new electromagnetic, semi-implantable hearing device. This study presents the details of clinical phase I, in which an electromagnetic driver was coupled with a target magnet temporarily affixed onto the lateral surface of the malleus of six hearing aid users with sensorineural losses. The results indicate that the electromagnetic hearing device provides sufficient gain and output characteristics to benefit individuals with sensorineural hearing loss. Significant improvements compared to conventional hearing aids were noted in pure-tone testing and, to a lesser degree, in speech discrimination. Subjective responses were quite favorable, indicating that the electromagnetic hearing device 1. produces no acoustic feedback; 2. works well in noisy environments; and 3. provides a more quiet, natural sound than patients' conventional hearing aids. These favorable results led to phase II of the project, in which patients with surgically amendable mixed hearing losses were implanted with the target magnet incorporated within a hydroxyapatite ossicular prosthesis. The results of this second-stage investigation were also encouraging and will be reported separately.

Comparison of lasers used in stapedotomy using specialized visualization techniques for mechanical and thermal effects in an inner ear model

NASA Astrophysics Data System (ADS)

Kamalski, Digna M. A.; Verdaasdonk, Rudolf M.; de Boorder, Tjeerd; Grolman, Wilko

2011-03-01

The outcome of stapedotomy depends on several surgical steps. Using laser light, the ossicular chain can be handled and the oval window can be punctured with a non-touch method. Various lasers are being used or considered, however, it is not clear which settings and characteristics will contribute to optimal or adverse effects (vestibule damage and loss hearing frequencies). Using a unique high speed thermal imaging setup based on Schlieren techniques, the mechanical and thermal effects during laser stapedotomy were studied in an inner ear model consisting of human, fresh frozen stapes positioned on a liquid filled cavity in a gel cast. The cw KTP (532 nm), cw CO2 (10.6 μm), cw Thulium (2.0 μm), pulsed Er,Cr;YSGG (2.78 μm) coupled to special fiber delivery systems were applied at typical clinical settings for comparison. The imaging techniques provided a good insight in the extent of heat conduction beneath the footplate and (explosive) vapour formation on both sides. For the pulsed laser modes, explosive vapour expansion can to be controlled with optimized pulse energies while for continuous wave lasers the thermal effects can be controlled with the pulse length and repetition rate. The fluence at the tip of the delivery system and the distance to the footplate has a major impact on the ablation effect. The pulsed IR lasers with fiber delivery show to be promising for a controlled stapedotomy.

Integration of implant planning workflows into the PACS infrastructure

NASA Astrophysics Data System (ADS)

Gessat, Michael; Strauß, Gero; Burgert, Oliver

2008-03-01

The integration of imaging devices, diagnostic workstations, and image servers into Picture Archiving and Communication Systems (PACS) has had an enormous effect on the efficiency of radiology workflows. The standardization of the information exchange between the devices with the DICOM standard has been an essential precondition for that development. For surgical procedures, no such infrastructure exists. With the increasingly important role computerized planning and assistance systems play in the surgical domain, an infrastructure that unifies the communication between devices becomes necessary. In recent publications, the need for a modularized system design has been established. A reference architecture for a Therapy Imaging and Model Management System (TIMMS) has been proposed. It was accepted by the DICOM Working Group 6 as the reference architecture for DICOM developments for surgery. In this paper we propose the inclusion of implant planning systems into the PACS infrastructure. We propose a generic information model for the patient specific selection and positioning of implants from a repository according to patient image data. The information models are based on clinical workflows from ENT, cardiac, and orthopedic surgery as well as technical requirements derived from different use cases and systems. We show an exemplary implementation of the model for application in ENT surgery: the selection and positioning of an ossicular implant in the middle ear. An implant repository is stored in the PACS. It makes use of an experimental implementation of the Surface Mesh Module that is currently being developed as extension to the DICOM standard.

Temporal bone bank: complying with European Union directives on human tissue and cells.

PubMed

Van Rompaey, Vincent; Vandamme, Wouter; Muylle, Ludo; Van de Heyning, Paul H

2012-06-01

Availability of allograft tympano-ossicular systems (ATOS) provides unique reconstructive capabilities, allowing more radical removal of middle ear pathology. To provide ATOS, the University of Antwerp Temporal Bone Bank (UATB) was established in 1988. ATOS use was stopped in many countries because of safety issues concerning human tissue transplantation. Our objective was to maintain an ATOS tissue bank complying with European Union (EU) directives on human tissues and cells. The guidelines of the Belgian Superior Health Council, including EU directive requirements, were rigorously applied to UATB infrastructure, workflow protocols and activity. Workflow protocols were updated and an internal audit was performed to check and improve consistency with established quality systems and changing legislations. The Belgian Federal Agency of Medicines and Health Products performed an inspection to examine compliance with national legislatives and EU directives on human tissues and cells. A sample of important procedures was meticulously examined in its workflow setting next to assessment of the infrastructure and personnel. Results are reported on infrastructure, personnel, administrative workflow, procurement, preparation, processing, distribution, internal audit and inspection by the competent authority. Donors procured: 2006, 93 (45.1%); 2007, 64 (20.6%); 2008, 56 (13.1%); 2009, 79 (6.9%). The UATB was approved by the Minister of Health without critical or important shortcomings. The Ministry accords registration each time for 2 years. An ATOS tissue bank complying with EU regulations on human allografts is feasible and critical to assure that the patient receives tissue, which is safe, individually checked and prepared in a suitable environment.

The palisade cartilage tympanoplasty technique: a systematic review and meta-analysis.

PubMed

Jeffery, Caroline C; Shillington, Cameron; Andrews, Colin; Ho, Allan

2017-06-17

Tympanoplasty is a common procedure performed by Otolaryngologists. Many types of autologous grafts have been used with variations of techniques with varying results. This is the first systematic review of the literature and meta-analysis with the aim to evaluate the effectiveness of one of the techniques which is gaining popularity, the palisade cartilage tympanoplasty. PubMed, EMBASE, and Cochrane databases were searched for "palisade", "cartilage", "tympanoplasty", "perforation" and their synonyms. In total, 199 articles reporting results of palisade cartilage tympanoplasty were identified. Five articles satisfied the following inclusion criteria: adult patients, minimum 6 months follow-up, hearing and surgical outcomes reported. Studies with patients undergoing combined mastoidectomy, ossicular chain reconstruction, and/or other middle ear surgery were excluded. Perforation closure, rate of complications, and post-operative pure-tone average change were extracted for pooled analysis. Study failure and complication proportions that were used to generate odds ratios were pooled. Fixed effects and random effects weightings were generated. The resulting pooled odds ratios are reported. Palisade cartilage tympanoplasty has an overall take rate of 96% at beyond 6 months and has similar odds of complications compared to temporalis fascia (OR 0.89, 95% CI 0.62, 1.30). The air-bone gap closure is statistically similar to reported results from temporalis fascia tympanoplasty. Cartilage palisade tympanoplasty offers excellent graft take rates and good postoperative hearing outcomes for perforations of various sizes and for both primary and revision cases. This technique has predictable, long-term results with low complication rates, similar to temporalis fascia tympanoplasty.

Ear Structures of the Naked Mole-Rat, Heterocephalus glaber, and Its Relatives (Rodentia: Bathyergidae)

PubMed Central

Mason, Matthew J.; Cornwall, Hannah L.; Smith, Ewan St. J.

2016-01-01

Although increasingly popular as a laboratory species, very little is known about the peripheral auditory system of the naked mole-rat, Heterocephalus glaber. In this study, middle and inner ears of naked mole-rats of a range of ages were examined using micro-computed tomography and dissection. The ears of five other bathyergid species (Bathyergus suillus, Cryptomys hottentotus, Fukomys micklemi, Georychus capensis and Heliophobius argenteocinereus) were examined for comparative purposes. The middle ears of bathyergids show features commonly found in other members of the Ctenohystrica rodent clade, including a fused malleus and incus, a synovial stapedio-vestibular articulation and the loss of the stapedius muscle. Heterocephalus deviates morphologically from the other bathyergids examined in that it has a more complex mastoid cavity structure, poorly-ossified processes of the malleus and incus, a ‘columelliform’ stapes and fewer cochlear turns. Bathyergids have semicircular canals with unusually wide diameters relative to their radii of curvature. How the lateral semicircular canal reaches the vestibule differs between species. Heterocephalus has much more limited high-frequency hearing than would be predicted from its small ear structures. The spongy bone forming its ossicular processes, the weak incudo-stapedial articulation, the columelliform stapes and (compared to other bathyergids) reduced cochlear coiling are all potentially degenerate features which might reflect a lack of selective pressure on its peripheral auditory system. Substantial intraspecific differences were found in certain middle and inner ear structures, which might also result from relaxed selective pressures. However, such interpretations must be treated with caution in the absence of experimental evidence. PMID:27926945

MRI information for commonly used otologic implants: review and update.

PubMed

Azadarmaki, Roya; Tubbs, Rhonda; Chen, Douglas A; Shellock, Frank G

2014-04-01

To review information on magnetic resonance imaging (MRI) issues for commonly used otologic implants. Manufacturing companies, National Library of Medicine's online database, and an additional online database (www.MRIsafety.com). A literature review of the National Library of Medicine's online database with focus on MRI issues for otologic implants was performed. The MRI information on implants provided by manufacturers was reviewed. Baha and Ponto Pro osseointegrated implants' abutment and fixture and the implanted magnet of the Sophono Alpha 1 and 2 abutment-free systems are approved for 3-Tesla magnetic resonance (MR) systems. The external processors of these devices are MR Unsafe. Of the implants tested, middle ear ossicular prostheses, including stapes prostheses, except for the 1987 McGee prosthesis, are MR Conditional for 1.5-Tesla (and many are approved for 3-Tesla) MR systems. Cochlear implants with removable magnets are approved for patients undergoing MRI at 1.5 Tesla after magnet removal. The MED-EL PULSAR, SONATA, CONCERT, and CONCERT PIN cochlear implants can be used in patients undergoing MRI at 1.5 Tesla with application of a protective bandage. The MED-EL COMBI 40+ can be used in 0.2-Tesla MR systems. Implants made from nonmagnetic and nonconducting materials are MR Safe. Knowledge of MRI guidelines for commonly used otologic implants is important. Guidelines on MRI issues approved by the US Food and Drug Administration are not always the same compared with other parts of the world. This monograph provides a current reference for physicians on MRI issues for commonly used otologic implants.

Mrmc Neo Surgical Ventilating Port and Neo Attic Malleo-Incudal Complex in Endoscopic Management of Limited Attico-Antral Cholesteatoma.

PubMed

Nandyal, C B; Sutrave, Mithun; Kurle, Vinayak; Harsoor, Pallavi A

2018-03-01

To study functional outcome of the endoscopic management of limited attico-antral cholesteatoma in terms of visualization of sac, cholesteatoma disease clearance, ABG closure improvement, preservation of residual anatomy and recurrence of disease. It is a prospective study done during Feb 2016 to March 2017 done on 20 pts with limited attico-antral cholesteatoma with CT confirmation. Endoscopic management of limited attico-antral cholesteatoma with complete removal of sac, infected discharge and granulations along with creation of MRMC Neo surgical ventilating port (joining Anterior & posterior isthmuses) done in cases where residual attic anatomy was present to establish physiological attic ventilation and drainage. Whereas in cases of attic and ossicular erosion, ossiculoplasty along with neo attic malleo-incudal complex (with composite tragal cartilage with perichondrium graft) for lateral attic wall reconstruction was done to prevent attic retraction. Patients had mean pre op ABG of 36.29 ± 6.29 and mean post op ABG closure of 16.33 ± 6.50 with no recurrence of cholesteatoma at 6 months of follow up. Patient showed significant (55%) improvement in hearing with all having graft uptake in which four cases having mild pars tensa retraction which recovered later without any intervention. Thus creation of new MRMC Neo surgical ventilating port or neo attic malleo-incudal complex with endoscopic approach allows better visual access to clear the limited attico-antral disease with sparing of normal residual attic anatomy along with physiological ventilation and drainage having better hearing results and outcome.

La Ferrassie 1: New perspectives on a "classic" Neandertal.

PubMed

Gómez-Olivencia, Asier; Quam, Rolf; Sala, Nohemi; Bardey, Morgane; Ohman, James C; Balzeau, Antoine

2018-04-01

The La Ferrassie 1 (LF1) skeleton, discovered over a century ago, is one of the most important Neandertal individuals both for its completeness and due to the role it has played historically in the interpretation of Neandertal anatomy and lifeways. Here we present new skeletal remains from this individual, which include a complete right middle ear ossicular chain (malleus, incus, and stapes), three vertebral fragments, and two costal remains. Additionally, the study of the skeleton has allowed us to identify new pathological lesions, including a congenital variant in the atlas, a greenstick fracture of the left clavicle, and a lesion in a mid-thoracic rib of unknown etiology. In addition, we have quantified the amount of vertebral pathology, which is greater than previously appreciated. We have complemented the paleopathological analysis with a taphonomic analysis to identify any potential perimortem fractures. The taphonomic analysis indicates that no surface alteration is present in the LF1 skeleton and that the breakage pattern is that of bone that has lost collagen, which would be consistent with the intentional burial of this individual proposed by previous researchers. In this study, we used CT and microCT scans in order to discover new skeletal elements to better characterize the pathological lesions and to quantify the fracture orientation of those bones in which the current plaster reconstruction did not allow its direct visualization, which underlines the broad potential of imaging technologies in paleoanthropological research. A century after its discovery, LF1 is still providing new insights into Neandertal anatomy and behavior. Copyright © 2018 Elsevier Ltd. All rights reserved.

Using the shortwave infrared to image middle ear pathologies

PubMed Central

Valdez, Tulio A.; Bruns, Oliver T.; Bawendi, Moungi G.

2016-01-01

Visualizing structures deep inside opaque biological tissues is one of the central challenges in biomedical imaging. Optical imaging with visible light provides high resolution and sensitivity; however, scattering and absorption of light by tissue limits the imaging depth to superficial features. Imaging with shortwave infrared light (SWIR, 1–2 μm) shares many advantages of visible imaging, but light scattering in tissue is reduced, providing sufficient optical penetration depth to noninvasively interrogate subsurface tissue features. However, the clinical potential of this approach has been largely unexplored because suitable detectors, until recently, have been either unavailable or cost prohibitive. Here, taking advantage of newly available detector technology, we demonstrate the potential of SWIR light to improve diagnostics through the development of a medical otoscope for determining middle ear pathologies. We show that SWIR otoscopy has the potential to provide valuable diagnostic information complementary to that provided by visible pneumotoscopy. We show that in healthy adult human ears, deeper tissue penetration of SWIR light allows better visualization of middle ear structures through the tympanic membrane, including the ossicular chain, promontory, round window niche, and chorda tympani. In addition, we investigate the potential for detection of middle ear fluid, which has significant implications for diagnosing otitis media, the overdiagnosis of which is a primary factor in increased antibiotic resistance. Middle ear fluid shows strong light absorption between 1,400 and 1,550 nm, enabling straightforward fluid detection in a model using the SWIR otoscope. Moreover, our device is easily translatable to the clinic, as the ergonomics, visual output, and operation are similar to a conventional otoscope. PMID:27551085

Heart valve replacement with the Sorin tilting-disc prosthesis. A 10-year experience.

PubMed

Milano, A; Bortolotti, U; Mazzucco, A; Mossuto, E; Testolin, L; Thiene, G; Gallucci, V

1992-02-01

From 1978 to 1988, 697 patients with a mean age of 48 +/- 11 years (range 5 to 75 years) received a Sorin tilting-disc prosthesis; 358 had had aortic valve replacement, 247 mitral valve replacement, and 92 mitral and aortic valve replacement. Operative mortality rates were 7.8%, 11.3%, and 10.8%, respectively, in the three groups. Cumulative duration of follow-up is 1650 patient-years for aortic valve replacement (maximum follow-up 11.4 years), 963 patient-years for mitral valve replacement (maximum follow-up 9.9 years) and 328 patient-years for mitral and aortic valve replacement (maximum follow-up 9.4 years). Actuarial survival at 9 years is 72% +/- 4% after mitral valve replacement, 70% +/- 3% after aortic valve replacement, and 50% +/- 12% after mitral and aortic valve replacement, and actuarial freedom from valve-related deaths is 97% +/- 2% after mitral valve replacement, 92% +/- 2% after aortic valve replacement, and 62% +/- 15% after mitral and aortic valve replacement. Thromboembolic events occurred in 21 patients with aortic valve replacement (1.3% +/- 0.2%/pt-yr), in 12 with mitral valve replacement (1.2% +/- 0.3% pt-yr), and in seven with mitral and aortic valve replacement (2.1% +/- 0.8%), with one case of prosthetic thrombosis in each group; actuarial freedom from thromboembolism at 9 years is 92% +/- 3% after mitral valve replacement, 91% +/- 3% after aortic valve replacement, and 74% +/- 16% after mitral and aortic valve replacement. Anticoagulant-related hemorrhage was observed in 15 patients after aortic valve replacement (0.9% +/- 0.2%/pt-yr), in 9 after mitral valve replacement (0.9% +/- 0.3%/pt-yr), and in 6 with mitral and aortic valve replacement (0.9% +/- 0.5%/pt-yr); actuarial freedom from this complication at 9 years is 94% +/- 2% after aortic valve replacement, 91% +/- 4% after mitral valve replacement, and 68% +/- 16% after mitral and aortic valve replacement. Actuarial freedom from reoperation at 9 years is 97% +/- 2% after mitral and aortic valve replacement, 92% +/- 4% after mitral valve replacement, and 89% +/- 3% after aortic valve replacement, with no cases of mechanical fracture. The Sorin valve has shown a satisfactory long-term overall performance, comparable with other mechanical prostheses, and an excellent durability that renders it a reliable heart valve substitute for the mitral and aortic positions.

Influence of Total Knee Arthroplasty on Gait Mechanics of the Replaced and Non-Replaced Limb During Stair Negotiation.

PubMed

Standifird, Tyler W; Saxton, Arnold M; Coe, Dawn P; Cates, Harold E; Reinbolt, Jeffrey A; Zhang, Songning

2016-01-01

This study compared biomechanics during stair ascent in replaced and non-replaced limbs of total knee arthroplasty (TKA) patients with control limbs of healthy participants. Thirteen TKA patients and fifteen controls performed stair ascent. Replaced and non-replaced knees of TKA patients were less flexed at contact compared to controls. The loading response peak knee extension moment was greater in control and non-replaced knees compared with replaced. The push-off peak knee abduction moment was elevated in replaced limbs compared to controls. Loading and push-off peak hip abduction moments were greater in replaced limbs compared to controls. The push-off peak hip abduction moment was greater in non-replaced limbs compared to controls. Future rehabilitation protocols should consider the replaced knee and also the non-replaced knee and surrounding joints. Copyright © 2016 Elsevier Inc. All rights reserved.

25 CFR 700.189 - Expenditure of replacement home benefits.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 25 Indians 2 2011-04-01 2011-04-01 false Expenditure of replacement home benefits. 700.189 Section... PROCEDURES Replacement Housing Payments § 700.189 Expenditure of replacement home benefits. Replacement home... maximum replacement home benefit. (b) All replacement home benefits shall be expended not later than one...

25 CFR 700.189 - Expenditure of replacement home benefits.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 25 Indians 2 2014-04-01 2014-04-01 false Expenditure of replacement home benefits. 700.189 Section... PROCEDURES Replacement Housing Payments § 700.189 Expenditure of replacement home benefits. Replacement home... maximum replacement home benefit. (b) All replacement home benefits shall be expended not later than one...

25 CFR 700.189 - Expenditure of replacement home benefits.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 25 Indians 2 2012-04-01 2012-04-01 false Expenditure of replacement home benefits. 700.189 Section... PROCEDURES Replacement Housing Payments § 700.189 Expenditure of replacement home benefits. Replacement home... maximum replacement home benefit. (b) All replacement home benefits shall be expended not later than one...

25 CFR 700.189 - Expenditure of replacement home benefits.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 25 Indians 2 2010-04-01 2010-04-01 false Expenditure of replacement home benefits. 700.189 Section... PROCEDURES Replacement Housing Payments § 700.189 Expenditure of replacement home benefits. Replacement home... maximum replacement home benefit. (b) All replacement home benefits shall be expended not later than one...

25 CFR 700.189 - Expenditure of replacement home benefits.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 25 Indians 2 2013-04-01 2013-04-01 false Expenditure of replacement home benefits. 700.189 Section... PROCEDURES Replacement Housing Payments § 700.189 Expenditure of replacement home benefits. Replacement home... maximum replacement home benefit. (b) All replacement home benefits shall be expended not later than one...

Finite element modelling of sound transmission from outer to inner ear.

PubMed

Areias, Bruno; Santos, Carla; Natal Jorge, Renato M; Gentil, Fernanda; Parente, Marco Pl

2016-11-01

The ear is one of the most complex organs in the human body. Sound is a sequence of pressure waves, which propagates through a compressible media such as air. The pinna concentrates the sound waves into the external auditory meatus. In this canal, the sound is conducted to the tympanic membrane. The tympanic membrane transforms the pressure variations into mechanical displacements, which are then transmitted to the ossicles. The vibration of the stapes footplate creates pressure waves in the fluid inside the cochlea; these pressure waves stimulate the hair cells, generating electrical signals which are sent to the brain through the cochlear nerve, where they are decoded. In this work, a three-dimensional finite element model of the human ear is developed. The model incorporates the tympanic membrane, ossicular bones, part of temporal bone (external auditory meatus and tympanic cavity), middle ear ligaments and tendons, cochlear fluid, skin, ear cartilage, jaw and the air in external auditory meatus and tympanic cavity. Using the finite element method, the magnitude and the phase angle of the umbo and stapes footplate displacement are calculated. Two slightly different models are used: one model takes into consideration the presence of air in the external auditory meatus while the other does not. The middle ear sound transfer function is determined for a stimulus of 60 dB SPL, applied to the outer surface of the air in the external auditory meatus. The obtained results are compared with previously published data in the literature. This study highlights the importance of external auditory meatus in the sound transmission. The pressure gain is calculated for the external auditory meatus.

Application of distortion product otoacoustic emissions to inflation of the eustachian tube in low frequency tinnitus with normal hearing.

PubMed

Wang, Hui; Song, Ningying; Li, Xujing; Lv, Hongguang

2013-06-01

This study was designed to investigate the applications of distortion product otoacoustic emissions to assess the efficacy of eustachian tube inflation on low frequency tinnitus with normal hearing. Ninety-four patients (155 ears) suffering from subjective tinnitus with normal hearing sensitivity participated in this study. Control group consists of fifty volunteers (100 ears) without tinnitus. They were subjected to full history taking, otoscopy, basic audiologic evaluation and distortion product otoacoustic emissions (DPOAE). As for the patients with decreased DPOAE amplitude over a limited frequency range from 0.5 to 1kHz, we offered nose dropping and tubal inflation for a week and DPOAE was preformed again. The patients were followed up for a month. 34.8% DPOAE-gram showed decreased amplitude at the frequencies from 0.5 to 1kHz in tinnitus group and "the ring" is mostly lower in pitch. Among the patients accepted the treatment of eustachian tube inflation, 16.7% the tinnitus disappeared, no recurrence within one month; 66.67% the tinnitus reduced within one month. 95.5% the amplitude of DPOAE showed improved over the limited frequency. 16.7% the tinnitus still existed. The changes of the mechanical properties of ossicular chain or the tympanic membrane influenced by tympanum pressure may cause tinnitus, which is sub-clinical prior to the changes of audiometry and tympanometry. The low frequency tinnitus may gain transitory relief from ringing with the tubal inflation. DPOAE was proved to be a useful tool in the evaluation of the efficacy of tubal inflation on low frequency tinnitus with normal hearing. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

[Preoperative CT Scan in middle ear cholesteatoma].

PubMed

Sethom, Anissa; Akkari, Khemaies; Dridi, Inès; Tmimi, S; Mardassi, Ali; Benzarti, Sonia; Miled, Imed; Chebbi, Mohamed Kamel

2011-03-01

To compare preoperative CT scan finding and per-operative lesions in patients operated for middle ear cholesteatoma, A retrospective study including 60 patients with cholesteatoma otitis diagnosed and treated within a period of 5 years, from 2001 to 2005, at ENT department of Military Hospital of Tunis. All patients had computed tomography of the middle and inner ear. High resolution CT scan imaging was performed using millimetric incidences (3 to 5 millimetres). All patients had surgical removal of their cholesteatoma using down wall technic. We evaluated sensitivity, specificity and predictive value of CT-scan comparing otitic damages and CT finding, in order to examine the real contribution of computed tomography in cholesteatoma otitis. CT scan analysis of middle ear bone structures shows satisfaction (with 83% of sensibility). The rate of sensibility decrease (63%) for the tympanic raff. Predictive value of CT scan for the diagnosis of cholesteatoma was low. However, we have noticed an excellent sensibility in the analysis of ossicular damages (90%). Comparative frontal incidence seems to be less sensible for the detection of facial nerve lesions (42%). But when evident on CT scan findings, lesions of facial nerve were usually observed preoperatively (spécificity 78%). Predictive value of computed tomography for the diagnosis of perilymphatic fistulae (FL) was low. In fact, CT scan imaging have showed FL only for four patients among eight. Best results can be obtained if using inframillimetric incidences with performed high resolution computed tomography. Preoperative computed tomography is necessary for the diagnosis and the evaluation of chronic middle ear cholesteatoma in order to show extending lesion and to detect complications. This CT analysis and surgical correlation have showed that sensibility, specificity and predictive value of CT-scan depend on the anatomic structure implicated in cholesteatoma damages.

Micro CT visualization of silver nanoparticles in the middle and inner ear of rat and transportation pathway after transtympanic injection.

PubMed

Zou, Jing; Hannula, Markus; Misra, Superb; Feng, Hao; Labrador, Roberto Hanoi; Aula, Antti S; Hyttinen, Jari; Pyykkö, Ilmari

2015-01-27

Silver nanoparticles (Ag NPs) displayed strong activities in anti-bacterial, anti-viral, and anti-fungal studies and were reportedly efficient in treating otitis media. Information on distribution of AgNPs in different compartments of the ear is lacking. To detect distribution of Ag NPs in the middle and inner ear and transportation pathways after transtympanic injection. Contrast effect of Ag NPs in the micro CT imaging was assessed in a phantom. AgNPs at various concentrations (1.85 mM, 37.1 mM, and 370.7 mM) were administered to rat middle ear using transtympanic injection and cadaver heads were imaged using micro CT at several time points. The lowest concentration of Ag NPs that could be visualized using micro CT was 37.1 mM. No difference was observed between the solvents, deionized H2O and saline. Ag NPs at 37.1 mM were visible in the middle ear on 7 d post-administration. Ag NPs at 370.7 mM generated signals in the middle ear, ossicular chain, round window membrane, oval window, scala tympani, and Eustachian tube for both 4 h and 24 h time points. A gradient distribution of Ag NPs from the middle ear to the inner ear was detected. The pathways for Ag NPs to be transported from the middle ear into the inner ear are round and oval windows. This study provided the imaging evidence that Ag NPs are able to access the inner ear in a dose-dependent manner after intratympanic administration, which is relevant to design the delivery concentration in the future clinic application in order to avoid adverse inner ear effect.

Sclerosteosis involving the temporal bone: histopathologic aspects.

PubMed

Nager, G T; Hamersma, H

1986-01-01

Sclerosteosis is a rare, potentially lethal, autosomal recessive, progressive craniotubular sclerosing bone dysplasia with characteristic facial and skeletal features. The temporal bone changes include a marked increase in overall size, extensive sclerosis, narrowing of the external auditory canal, and severe constriction of the internal auditory meatus, fallopian canal, eustachian tube, and middle ear cleft. Attenuation of the bony canals of the 9th, 10th, and 11th cranial nerves, reduction in size of the internal carotid artery, and severe obliteration of the sigmoid sinus and jugular bulb also occur. Loss of hearing, generally bilateral, is a frequent symptom. It often manifests in early childhood and initially is expressed as sound conduction impairment. Later, a sensorineural hearing loss and loss of vestibular nerve function often develop. Impairment of facial nerve function is another feature occasionally present at birth. In the beginning, a unilateral intermittent facial weakness may occur which eventually progresses to a bilateral permanent facial paresis. The histologic examination of the temporal bones from a patient with sclerosteosis explains the mechanisms involved in the progressive impairment of sound conduction and loss of cochlear, vestibular, and facial nerve function. There is a decrease of the arterial blood supply to the brain and an obstruction of the venous drainage from it. The histopathology reveals the obstacles to decompression of the middle ear cleft, ossicular chain, internal auditory and facial canals, and the risks, and in many instances the contraindications, to such procedures. On the other hand, decompression of the sigmoid sinus and jugular bulb should be considered as an additional life-saving procedure in conjunction with the prophylactic craniotomy recommended in all adult patients.

[Comparative evaluation of vertigo in patients after stapedotomy and stapedectomy].

PubMed

Harmat, Kinga; Thurén, Gergely; Simon, László; Nepp, Nelli; Németh, Adrienn; Gerlinger, Imre; Bakó, Péter

2017-09-01

The reason of gradually developing conductive hearing loss in otosclerotic patients is the ossification of the stapes footplate to the surrounding bony structures and the therapy of stapes fixation is mainly surgical. In stapedotomy the footplate of the stapes is fenestrated with laser and microdrill in a diameter of 0.8 mm, whereas in stapedectomy there is complete removal of the footplate followed by the reconstruction of the ossicular chain. In the early postoperative period, temporary vertigo is frequently recorded which significantly influences the recovery. In the Department of Otorhinolaryngology, University of Pécs both stapedectomy and stapedotomy were performed on a daily basis between 01.02.2010 and 15.03.2012. Our study focused on comparing the degree of postoperative vertigo after the two types of surgery. We hypothesized that the smaller fenestration of the stapes footplate during stapedotomy limits exposure to the inner ear reducing the severity of dizziness. Vertigo was evaluated subjectively with a retrospective questionnaire and objectively with static posturography. On the 1st postoperative day, significantly fewer patients reported vertigo in the stapedotomy group and with significantly lower intensity. Results of the questionnaire regarding the later postoperative period showed no significant differences between the groups. Based on the analysis of the posturography test results, no significant difference was detected between the postoperative stability of the two groups. Results of the questionnaire and the posturography showed no correlation. Posturography test results did not confirm the presence of subjective vertigo. Many factors may play a role in the development of vertigo after stapes surgery, but the type of intervention does not influence it. Orv Hetil. 2017; 158(38): 1503-1511.

Hip joint replacement

MedlinePlus

... Total hip replacement; Hip hemiarthroplasty; Arthritis - hip replacement; Osteoarthritis - hip replacement ... total hip replacement surgery in patients with hip osteoarthritis: a long-term follow-up of a randomised ...

Radiological/biological/aerosol removal system

DOEpatents

Haslam, Jeffery J

2015-03-17

An air filter replacement system for existing buildings, vehicles, arenas, and other enclosed airspaces includes a replacement air filter for replacing a standard air filter. The replacement air filter has dimensions and air flow specifications that allow it to replace the standard air filter. The replacement air filter includes a filter material that removes radiological or biological or aerosol particles.

Shoulder replacement - discharge

MedlinePlus

Total shoulder arthroplasty - discharge; Endoprosthetic shoulder replacement - discharge; Partial shoulder replacement - discharge; Partial shoulder arthroplasty - discharge; Replacement - shoulder - discharge; Arthroplasty - shoulder - ...

Frequency and impact of informant replacement in Alzheimer disease research.

PubMed

Grill, Joshua D; Zhou, Yan; Karlawish, Jason; Elashoff, David

2015-01-01

Informants serve an essential role in Alzheimer disease research. Were an informant to be replaced during a longitudinal study, this could have negative implications. We used data from the National Alzheimer's Coordinating Center Uniform Data Set to examine the frequency of informant replacement among Alzheimer disease dementia participants, whether patient and informant characteristics were associated with replacement, and how replacement affected research outcome measures. Informant replacement was common (15.5%) and typically occurred after the first or the second research visit. Adult child (24%) and other (38%) informants were more frequently replaced than spouse informants (10%). Older spouse informant age and younger adult child informant age were associated with replacement. The between-visit change in Functional Assessment Questionnaire scores was greater in patients who replaced informants than in those with stable informants. Clinical Dementia Rating-Sum of Boxes, Functional Assessment Questionnaire, and Neuropsychiatric Inventory scores showed greater variability in between-visit change in patients who replaced informants compared with those with stable informants. These findings suggest that informant replacement is relatively common, may have implications to study analyses, and warrant further examination in the setting of clinical trials.

Evolution of high tooth replacement rates in sauropod dinosaurs.

PubMed

D'Emic, Michael D; Whitlock, John A; Smith, Kathlyn M; Fisher, Daniel C; Wilson, Jeffrey A

2013-01-01

Tooth replacement rate can be calculated in extinct animals by counting incremental lines of deposition in tooth dentin. Calculating this rate in several taxa allows for the study of the evolution of tooth replacement rate. Sauropod dinosaurs, the largest terrestrial animals that ever evolved, exhibited a diversity of tooth sizes and shapes, but little is known about their tooth replacement rates. We present tooth replacement rate, formation time, crown volume, total dentition volume, and enamel thickness for two coexisting but distantly related and morphologically disparate sauropod dinosaurs Camarasaurus and Diplodocus. Individual tooth formation time was determined by counting daily incremental lines in dentin. Tooth replacement rate is calculated as the difference between the number of days recorded in successive replacement teeth. Each tooth family in Camarasaurus has a maximum of three replacement teeth, whereas each Diplodocus tooth family has up to five. Tooth formation times are about 1.7 times longer in Camarasaurus than in Diplodocus (315 vs. 185 days). Average tooth replacement rate in Camarasaurus is about one tooth every 62 days versus about one tooth every 35 days in Diplodocus. Despite slower tooth replacement rates in Camarasaurus, the volumetric rate of Camarasaurus tooth replacement is 10 times faster than in Diplodocus because of its substantially greater tooth volumes. A novel method to estimate replacement rate was developed and applied to several other sauropodomorphs that we were not able to thin section. Differences in tooth replacement rate among sauropodomorphs likely reflect disparate feeding strategies and/or food choices, which would have facilitated the coexistence of these gigantic herbivores in one ecosystem. Early neosauropods are characterized by high tooth replacement rates (despite their large tooth size), and derived titanosaurs and diplodocoids independently evolved the highest known tooth replacement rates among archosaurs.

Evolution of High Tooth Replacement Rates in Sauropod Dinosaurs

PubMed Central

Smith, Kathlyn M.; Fisher, Daniel C.; Wilson, Jeffrey A.

2013-01-01

Background Tooth replacement rate can be calculated in extinct animals by counting incremental lines of deposition in tooth dentin. Calculating this rate in several taxa allows for the study of the evolution of tooth replacement rate. Sauropod dinosaurs, the largest terrestrial animals that ever evolved, exhibited a diversity of tooth sizes and shapes, but little is known about their tooth replacement rates. Methodology/Principal Findings We present tooth replacement rate, formation time, crown volume, total dentition volume, and enamel thickness for two coexisting but distantly related and morphologically disparate sauropod dinosaurs Camarasaurus and Diplodocus. Individual tooth formation time was determined by counting daily incremental lines in dentin. Tooth replacement rate is calculated as the difference between the number of days recorded in successive replacement teeth. Each tooth family in Camarasaurus has a maximum of three replacement teeth, whereas each Diplodocus tooth family has up to five. Tooth formation times are about 1.7 times longer in Camarasaurus than in Diplodocus (315 vs. 185 days). Average tooth replacement rate in Camarasaurus is about one tooth every 62 days versus about one tooth every 35 days in Diplodocus. Despite slower tooth replacement rates in Camarasaurus, the volumetric rate of Camarasaurus tooth replacement is 10 times faster than in Diplodocus because of its substantially greater tooth volumes. A novel method to estimate replacement rate was developed and applied to several other sauropodomorphs that we were not able to thin section. Conclusions/Significance Differences in tooth replacement rate among sauropodomorphs likely reflect disparate feeding strategies and/or food choices, which would have facilitated the coexistence of these gigantic herbivores in one ecosystem. Early neosauropods are characterized by high tooth replacement rates (despite their large tooth size), and derived titanosaurs and diplodocoids independently evolved the highest known tooth replacement rates among archosaurs. PMID:23874921

Replacement Condition Detection of Railway Point Machines Using an Electric Current Sensor.

PubMed

Sa, Jaewon; Choi, Younchang; Chung, Yongwha; Kim, Hee-Young; Park, Daihee; Yoon, Sukhan

2017-01-29

Detecting replacement conditions of railway point machines is important to simultaneously satisfy the budget-limit and train-safety requirements. In this study, we consider classification of the subtle differences in the aging effect-using electric current shape analysis-for the purpose of replacement condition detection of railway point machines. After analyzing the shapes of after-replacement data and then labeling the shapes of each before-replacement data, we can derive the criteria that can handle the subtle differences between "does-not-need-to-be-replaced" and "needs-to-be-replaced" shapes. On the basis of the experimental results with in-field replacement data, we confirmed that the proposed method could detect the replacement conditions with acceptable accuracy, as well as provide visual interpretability of the criteria used for the time-series classification.

78 FR 21924 - Alabama Power Company; Notice of Application for Amendment of License and Soliciting Comments...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-04-12

... approval to replace the Unit 4 turbine at the Jordan Dam Project. Specifically, the licensee proposes the following work: complete turbine replacement, wicket gate system rehabilitation or replacement, gate stem bushing replacement, turbine and generator bearing refurbishment, and related component replacement. The...

25 CFR 700.187 - Utilization of replacement home benefits.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 25 Indians 2 2012-04-01 2012-04-01 false Utilization of replacement home benefits. 700.187 Section... PROCEDURES Replacement Housing Payments § 700.187 Utilization of replacement home benefits. The Commission... to the head of household as provided in these regulations for the acquisition of a replacement home...

25 CFR 700.187 - Utilization of replacement home benefits.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 25 Indians 2 2013-04-01 2013-04-01 false Utilization of replacement home benefits. 700.187 Section... PROCEDURES Replacement Housing Payments § 700.187 Utilization of replacement home benefits. The Commission... to the head of household as provided in these regulations for the acquisition of a replacement home...

25 CFR 700.187 - Utilization of replacement home benefits.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 25 Indians 2 2011-04-01 2011-04-01 false Utilization of replacement home benefits. 700.187 Section... PROCEDURES Replacement Housing Payments § 700.187 Utilization of replacement home benefits. The Commission... to the head of household as provided in these regulations for the acquisition of a replacement home...

25 CFR 700.187 - Utilization of replacement home benefits.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 25 Indians 2 2010-04-01 2010-04-01 false Utilization of replacement home benefits. 700.187 Section... PROCEDURES Replacement Housing Payments § 700.187 Utilization of replacement home benefits. The Commission... to the head of household as provided in these regulations for the acquisition of a replacement home...

25 CFR 700.187 - Utilization of replacement home benefits.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 25 Indians 2 2014-04-01 2014-04-01 false Utilization of replacement home benefits. 700.187 Section... PROCEDURES Replacement Housing Payments § 700.187 Utilization of replacement home benefits. The Commission... to the head of household as provided in these regulations for the acquisition of a replacement home...

Replacing The Engine In Your Car While You Are Still Driving It [PowerPoint

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bjorklund, Eric A.

The scope of the project included the following: install new network backbone, replace 201 MHz rf tubes, replace low-level rf system, replace timing system, replace industrial I/O system, replace beam synchronous data acquisition system, replace fast protect reporting system, new wire scanner hardware, and new beam position/phase monitor hardware--all of this to be done while continuing to deliver beam to users. Lessons learned, for anyone contemplating a similarly ambitious upgrade: You can’t replace the whole system at once. Some compatibility must be maintained between the old and new systems. Always have a way to fall back. Have sympathy for themore » operations staff. You will be surprised.« less

Hormone replacement therapy in the developing countries.

PubMed

Oei, P L; Ratnam, S S

1998-05-01

The sales data of oestrogen replacement products for 8 developing countries from 1993 to 1995 were analyzed. The data from Malaysia, Pakistan, Taiwan, Thailand, Indonesia, Philippines and South Korea showed the increasing use of oestrogen replacement products. The total usage however varied widely, from only US$11,153 (Philippines in 1993) to as much as US$6,306,717 (Taiwan in 1995). In Singapore, where oestrogen replacement is an accepted and established form of therapy for the postmenopausal woman, there has been an increase in the usage of the nonoestrogen replacement products. There are multiple reasons for the increasing sales of hormone replacement products in the developing countries and these are explored in this article. In some of the developing countries, for example China and India, hormone replacement therapy has just been introduced. However, in those developing countries in which hormone replacement therapy is already available, sales figures show increasing usage. The future augurs well for hormone replacement therapy.

26 CFR 1.168-5 - Special rules.

Code of Federal Regulations, 2010 CFR

2010-04-01

...) Retirement-replacement-betterment (RRB) property—(1) RRB replacement property placed in service before... for the taxable year for retirement-replacement-betterment (RRB) replacement property (as defined in...

Roguing with replacement in perennial crops: conditions for successful disease management.

PubMed

Sisterson, Mark S; Stenger, Drake C

2013-02-01

Replacement of diseased plants with healthy plants is commonly used to manage spread of plant pathogens in perennial cropping systems. This strategy has two potential benefits. First, removing infected plants may slow pathogen spread by eliminating inoculum sources. Second, replacing infected plants with uninfected plants may offset yield losses due to disease. The extent to which these benefits are realized depends on multiple factors. In this study, sensitivity analyses of two spatially explicit simulation models were used to evaluate how assumptions concerning implementation of a plant replacement program and pathogen spread interact to affect disease suppression. In conjunction, effects of assumptions concerning yield loss associated with disease and rates of plant maturity on yields were simultaneously evaluated. The first model was used to evaluate effects of plant replacement on pathogen spread and yield on a single farm, consisting of a perennial crop monoculture. The second model evaluated effects of plant replacement on pathogen spread and yield in a 100 farm crop growing region, with all farms maintaining a monoculture of the same perennial crop. Results indicated that efficient replacement of infected plants combined with a high degree of compliance among farms effectively slowed pathogen spread, resulting in replacement of few plants and high yields. In contrast, inefficient replacement of infected plants or limited compliance among farms failed to slow pathogen spread, resulting in replacement of large numbers of plants (on farms practicing replacement) with little yield benefit. Replacement of infected plants always increased yields relative to simulations without plant replacement provided that infected plants produced no useable yield. However, if infected plants produced useable yields, inefficient removal of infected plants resulted in lower yields relative to simulations without plant replacement for perennial crops with long maturation periods in some cases.

Implementation of a timed, electronic, assessment-driven potassium-replacement protocol.

PubMed

Zielenski, Christopher; Crabtree, Adam; Le, Tien; Marlatt, Alyse; Ng, Dana; Tran, Alan

2017-06-15

The adherence to and effectiveness and safety of a timed, electronic, assessment-driven potassium-replacement protocol (TARP) were compared with an electronic nurse-driven replacement protocol (NRP) are reported. A retrospective observational study was conducted in a community hospital evaluating protocol adherence, effectiveness, and safety for 2 potassium-replacement protocols. All adults on medical units with an order for potassium replacement per protocol during the 3-month trial periods were reviewed. All patients requiring potassium replacement per protocol were included in the analysis. Adherence to the protocol was assessed by evaluating the dose of potassium administered and performance of reassessments. Effectiveness of the protocol was assessed by evaluating the time to achieve target potassium levels. Safety was assessed by evaluating the route of administration and occurrence of hyperkalemia. A total of 300 patients treated using potassium-replacement protocols required potassium replacement during the study period, with 148 patients in the NRP group requiring 491 instances of potassium replacement. In the TARP group a total of 564 instances requiring potassium replacement corresponded to 152 patients. Of the 491 instances requiring replacement in the NRP group, the correct dose was administered and reassessment performed 117 times (23.8%). Overall adherence ( p < 0.05), correct dose given ( p < 0.05), average time from blood draw to potassium replacement ( p < 0.0001), use of oral replacement ( p < 0.05), and time to achieve target potassium level within 12 hours ( p < 0.05) were significantly improved in the TARP group. The TARP improved the effectiveness and safety of potassium-replacement therapy over the traditional NRP without negatively affecting timeliness of care. Copyright © 2017 by the American Society of Health-System Pharmacists, Inc. All rights reserved.

Menopausal Symptom Relief and Side Effects Experienced by Women Using Bioidentical Hormone Replacement Therapy and Synthetic Conjugated Equine Estrogen and/or Progestin Hormone Replacement Therapy, Part 1.

PubMed

Deleruyelle, Laura J

2016-01-01

The use of compounded bioidentical hormone replacement therapy by menopausal women has become a popular alternative to traditional synthetic conjugated equine estrogen and progestin hormone replacement therapy due to safety concerns raised by recent studies. However, due to the lack of randomized, large-scale trials to evaluate the efficacy and side-effect profile of compounded bioidentical hormone replacement therapy many healthcare providers are reluctant to prescribe such therapy. The purpose of this study was to compare women's menopausal symptom relief and side effects experienced when using compounded bioidentical hormone replacement therapy and traditional hormone replacement therapy. A descriptive comparative design was used. Inferential and descriptive statistical procedures including a paired difference t -test, two-sample t -test, and f tests (percentage, mean, standard deviation, frequency) were run on the Statistical Package for the Social Sciences. The framework used to guide this study was Lenz and Pugh's Theory of Unpleasant Symptoms. Surveys were distributed once to a convenient sample of women aged 35 and older when they dropped off or picked up their prescriptions at a pharmacy. Of the 216 surveys distributed, 70 were returned from those women taking compounded bioidentical hormone replacement therapy and 53 from traditional hormone replacement therapy. The survey contained 15 questions pertaining to age, duration of hormone replacement therapy, type and formulation of hormone replacement therapy, reasons for initiating hormone replacement therapy, symptoms before and one month after hormone replacement therapy, and side effects related to hormone replacement therapy. The results of this study will be summarized in forthcoming articles in this series. Copyright© by International Journal of Pharmaceutical Compounding, Inc.

41 CFR 109-38.402-50 - Prompt disposal of replaced motor vehicles.

Code of Federal Regulations, 2011 CFR

2011-01-01

... replaced motor vehicles. 109-38.402-50 Section 109-38.402-50 Public Contracts and Property Management... REGULATIONS AVIATION, TRANSPORTATION, AND MOTOR VEHICLES 38-MOTOR EQUIPMENT MANAGEMENT 38.4-Use and Replacement Standards § 109-38.402-50 Prompt disposal of replaced motor vehicles. A replaced motor vehicle...

30 CFR 872.29 - What are prior balance replacement funds?

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 3 2010-07-01 2010-07-01 false What are prior balance replacement funds? 872... § 872.29 What are prior balance replacement funds? “Prior balance replacement funds” are moneys we must... SMCRA, we distribute prior balance replacement funds to you, the State or Indian tribe, for seven years...

30 CFR 872.29 - What are prior balance replacement funds?

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 3 2011-07-01 2011-07-01 false What are prior balance replacement funds? 872... § 872.29 What are prior balance replacement funds? “Prior balance replacement funds” are moneys we must... SMCRA, we distribute prior balance replacement funds to you, the State or Indian tribe, for seven years...

The impact of changes in LVEF and renal function on the prognosis of ICD patients after elective device replacement.

PubMed

Vandenberk, Bert; Robyns, Tomas; Garweg, Christophe; Floré, Vincent; Foulon, Stefaan; Voros, Gabor; Ector, Joris; Willems, Rik

2017-10-01

A proportion of patients with an implantable cardioverter-defibrillator (ICD) in prevention of sudden cardiac death will only receive their first appropriate ICD therapy (AT) after device replacement. Clinical reassessment at the time of replacement could be helpful to guide the decision to replace or not in the future. All patients with an ICD for primary or secondary prevention in ischemic (ICM) or nonischemic cardiomyopathy were included in a single-center retrospective registry. The association of changes in left ventricular ejection fraction (LVEF; cut-off at 35%), worsening renal function (decrease in estimated glomerular filtration rate > 15 mL/min), and worsening New York Heart Association class at elective device replacement with mortality and AT was analyzed using adjusted Cox regression analysis. A total of 238 (33%) out of 727 patients received elective device replacement (86.1% male, 74.4% ICM, 42.9% primary prevention). During this replacement 20.2% received a device upgrade. The mean time to replacement was 6.4 ± 2.0 years and mean follow-up after replacement was 3.4 ± 3.0 years. Of patients who did not receive AT before replacement 23.1% received their first AT after replacement. Worsening renal function (hazard ratio [HR] 2.79, 95% confidence interval [CI] 1.50-5.18) and a consistently LVEF ≤35% compared to a consistently LVEF >35% (HR 2.15, 95% CI 1.10-4.19) at the time of replacement were independent predictors of mortality. Independent predictors of first AT after replacement could not be identified. Although reassessment of LVEF and renal function at replacement can be helpful in predicting total mortality, the clinical utility to guide reimplantation seemed limited. Our experience indicates that approximately 25% of patients received their first AT only after replacement. © 2017 Wiley Periodicals, Inc.

A comparison of conventional surgery, transcatheter aortic valve replacement, and sutureless valves in "real-world" patients with aortic stenosis and intermediate- to high-risk profile.

PubMed

Muneretto, Claudio; Alfieri, Ottavio; Cesana, Bruno Mario; Bisleri, Gianluigi; De Bonis, Michele; Di Bartolomeo, Roberto; Savini, Carlo; Folesani, Gianluca; Di Bacco, Lorenzo; Rambaldini, Manfredo; Maureira, Juan Pablo; Laborde, Francois; Tespili, Maurizio; Repossini, Alberto; Folliguet, Thierry

2015-12-01

We sought to investigate the clinical outcomes of patients with isolated severe aortic stenosis and an intermediate- to high-risk profile treated by means of conventional surgery (surgical aortic valve replacement), sutureless valve implantation, or transcatheter aortic valve replacement in a multicenter evaluation. Among 991 consecutive patients with isolated severe aortic stenosis and an intermediate- to high-risk profile (Society of Thoracic Surgeons score >4 and logistic European System for Cardiac Operative Risk Evaluation I >10), a propensity score analysis was performed on the basis of the therapeutic strategy: surgical aortic valve replacement (n = 204), sutureless valve implantation (n = 204), and transcatheter aortic valve replacement (n = 204). Primary end points were 30-day mortality and overall survival at 24-month follow-up; the secondary end point was survival free from a composite end point of major adverse cardiac events (defined as cardiac-related mortality, myocardial infarction, cerebrovascular accidents, and major hemorrhagic events) and periprosthetic regurgitation greater than 2. Thirty-day mortality was significantly higher in the transcatheter aortic valve replacement group (surgical aortic valve replacement = 3.4% vs sutureless = 5.8% vs transcatheter aortic valve replacement = 9.8%; P = .005). The incidence of postprocedural was 3.9% in asurgical aortic valve replacement vs 9.8% in sutureless vs 14.7% in transcatheter aortic valve replacement (P< .001) and peripheral vascular complications occurred in 0% of surgicalaortic valve replacement vs 0% of sutureless vs 9.8% transcatheter aortic valve replacement (P< .001). At 24-month follow-up, overall survival (surgical aortic valve replacement = 91.3% ± 2.4% vs sutureless = 94.9% ± 2.1% vs transcatheter aortic valve replacement = 79.5% ± 4.3%; P < .001) and survival free from the composite end point of major adverse cardiovascular events and periprosthetic regurgitation were significantly better in patients undergoing surgical aortic valve replacement and sutureless valve implantation than in patients undergoing transcatheter aortic valve replacement (surgical aortic valve replacement = 92.6% ± 2.3% vs sutureless = 96% ± 1.8% vs transcatheter aortic valve replacement = 77.1% ± 4.2%; P < .001). Multivariate Cox regression analysis identified transcatheter aortic valve replacement as an independent risk factor for overall mortality hazard ratio (hazard ratio, 2.5; confidence interval, 1.1-4.2; P = .018). The use of transcatheter aortic valve replacement in patients with an intermediate- to high-risk profile was associated with a significantly higher incidence of perioperative complications and decreased survival at short- and mid-term when compared with conventional surgery and sutureless valve implantation. Copyright © 2015 The American Association for Thoracic Surgery. Published by Elsevier Inc. All rights reserved.

Hip or knee replacement - in the hospital after

MedlinePlus

Hip replacement surgery - after - self-care; Knee replacement surgery - after - self-care ... taking walks in the hallways with help. After knee replacement, some surgeons recommend using a continuous passive ...

Mechanical valve replacement in congenital heart disease.

PubMed

Fiane, A E; Lindberg, H L; Saatvedt, K; Svennevig, J L

1996-05-01

Mechanical valves are the prosthesis of choice in valve replacement in children. However, the problem of somatic growth leading to patient-valve mismatch remains present, and the appropriate anticoagulation regimen remains controversial. We present our experience of valve replacement in a young population over 20 years. Between 1972 and 1992, 48 patients (34 males and 14 females), mean age 11.2 years (range 0.4-27.4 years), underwent mechanical valve replacement at our institution. Aortic valve replacement was performed in 28 patients (58.3%), mitral valve replacement in 13 (27.1%), tricuspid valve replacement in six (12.5%) and pulmonary valve replacement in one patient (2.1%). The prostheses used were: St. Jude Medical (n = 2), Björk-Shiley (n = 14), Medtronic Hall (n = 16), Duromedics (n = 2) and CarboMedics (n = 14). Early mortality was 14.3%, 10.7% for aortic valve replacement and 30.8% for mitral valve replacement. Mean follow up for all patients was 8.3 years (range 0-22 years), with a total of 398 patient-years. Seven patients died during the follow up (17.1%). Survival after 10 years, including operative mortality, was 81% for aortic valve replacement, 33% for mitral valve replacement, 83% for tricuspid valve replacement and 100% for pulmonary valve replacement. All patients were anticoagulated with warfarin. In eight patients (16.7%) an antiplatelet drug (aspirin or dipyridamole) was added. Major events included paravalvular leak in six patients (1.5%/pty), valve thrombosis in five (mitral position in two, tricuspid in three) (1.3%/pty) and endocarditis in one patient (0.3%/pty). Minor thromboembolic events occurred in three patients (0.8%/pty) and minor hemorrhagic events in three (0.8%/pty). No patients developed hemolytic anemia and there was no case of structural failure. In our experience, mechanical prostheses in congenital heart disease were associated with significant morbidity and mortality, however long term survival after aortic valve replacement was good (81% at 10 years). Thromboembolic and hemorrhagic events were of minor significance. Atrio-ventricular valve replacement carried the highest risk of valve thrombosis and we now give warfarin and an antiplatelet drug to children undergoing mechanical valve implantation in this position.

42 CFR 433.117 - Initial approval of replacement systems.

Code of Federal Regulations, 2011 CFR

2011-10-01

... and Information Retrieval Systems § 433.117 Initial approval of replacement systems. (a) A replacement... information retrieval system. (b) The agency must submit a APD that includes— (1) The date the replacement...

42 CFR 433.117 - Initial approval of replacement systems.

Code of Federal Regulations, 2012 CFR

2012-10-01

... and Information Retrieval Systems § 433.117 Initial approval of replacement systems. (a) A replacement... information retrieval system. (b) The agency must submit a APD that includes— (1) The date the replacement...

42 CFR 433.117 - Initial approval of replacement systems.

Code of Federal Regulations, 2013 CFR

2013-10-01

... and Information Retrieval Systems § 433.117 Initial approval of replacement systems. (a) A replacement... information retrieval system. (b) The agency must submit a APD that includes— (1) The date the replacement...

42 CFR 433.117 - Initial approval of replacement systems.

Code of Federal Regulations, 2014 CFR

2014-10-01

... and Information Retrieval Systems § 433.117 Initial approval of replacement systems. (a) A replacement... information retrieval system. (b) The agency must submit a APD that includes— (1) The date the replacement...

Hip or knee replacement - after - what to ask your doctor

MedlinePlus

... chap 7. Read More Hip joint replacement Hip pain Knee joint replacement Knee pain Osteoarthritis Patient Instructions Getting your home ready - knee or hip surgery Hip or knee replacement - before - ...

Hip or knee replacement - before - what to ask your doctor

MedlinePlus

... chap 7. Read More Hip joint replacement Hip pain Knee joint replacement Knee pain Osteoarthritis Patient Instructions Getting your home ready - knee or hip surgery Hip or knee replacement - after - ...

Estrogen and Progestin (Hormone Replacement Therapy)

MedlinePlus

... progestin are two female sex hormones. Hormone replacement therapy works by replacing estrogen hormone that is no ... Progestin is added to estrogen in hormone replacement therapy to reduce the risk of uterine cancer in ...

The use of synthetic ligaments in the design of an enhanced stability total knee joint replacement.

PubMed

Stokes, Michael D; Greene, Brendan C; Pietrykowski, Luke W; Gambon, Taylor M; Bales, Caroline E; DesJardins, John D

2018-03-01

Current total knee replacement designs work to address clinically desired knee stability and range of motion through a balance of retained anatomy and added implant geometry. However, simplified implant geometries such as bearing surfaces, posts, and cams are often used to replace complex ligamentous constraints that are sacrificed during most total knee replacement procedures. This article evaluates a novel total knee replacement design that incorporates synthetic ligaments to enhance the stability of the total knee replacement system. It was hypothesized that by incorporating artificial cruciate ligaments into a total knee replacement design at specific locations and lengths, the stability of the total knee replacement could be significantly altered while maintaining active ranges of motion. The ligament attachment mechanisms used in the design were evaluated using a tensile test, and determined to have a safety factor of three with respect to expected ligamentous loading in vivo. Following initial computational modeling of possible ligament orientations, a physical prototype was constructed to verify the function of the design by performing anterior/posterior drawer tests under physiologic load. Synthetic ligament configurations were found to increase total knee replacement stability up to 94% compared to the no-ligament case, while maintaining total knee replacement flexion range of motion between 0° and 120°, indicating that a total knee replacement that incorporates synthetic ligaments with calibrated location and lengths should be able to significantly enhance and control the kinematic performance of a total knee replacement system.

Urban chaos and replacement dynamics in nature and society

NASA Astrophysics Data System (ADS)

Chen, Yanguang

2014-11-01

Replacements resulting from competition are ubiquitous phenomena in both nature and society. The evolution of a self-organized system is always a physical process substituting one type of components for another type of components. A logistic model of replacement dynamics has been proposed in terms of technical innovation and urbanization, but it fails to arouse widespread attention in the academia. This paper is devoted to laying the foundations of general replacement principle by using analogy and induction. The empirical base of this study is urban replacement, including urbanization and urban growth. The sigmoid functions can be employed to model various processes of replacement. Many mathematical methods such as allometric scaling and head/tail breaks can be applied to analyzing the processes and patterns of replacement. Among varied sigmoid functions, the logistic function is the basic and the simplest model of replacement dynamics. A new finding is that replacement can be associated with chaos in a nonlinear system, e.g., urban chaos is just a part of replacement dynamics. The aim of developing replacement theory is at understanding complex interaction and conversion. This theory provides a new way of looking at urbanization, technological innovation and diffusion, Volterra-Lotka’s predator-prey interaction, man-land relation, and dynastic changes resulting from peasant uprising, and all that. Especially, the periodic oscillations and chaos of replacement dynamics can be used to explain and predict the catastrophic occurrences in the physical and human systems.

The value of genetic information in selecting dairy replacements.

PubMed

Radke, Brian R; Lloyd, James W; Black, J Roy; Harsh, Stephen

2005-09-30

The objective of this study was to empirically determine the economic value of genetic information in the selection of dairy replacements, and assess whether this value was sufficient to prompt producers to select replacements on this basis. The data set consisted of 1982 Michigan Holstein replacements in 115 herds. Each herd had a minimum of 10 replacements that were born in the last 6 months of 1992 and calved within the last 6 months of 1994. The data for each replacement included the estimated breeding value (EBV) for milk at the beginning and end of the rearing period, and the estimated lifetime profit corrected for the opportunity cost of postponed replacement (ELPCOC). The replacement selection decision for a profit-maximizing dairy producer selecting 70 or 80% of the replacements was modeled. We modeled three methods of selection: genetic, random and ex poste. Genetic selection was evaluated using the EBV milk available at the beginning or end of the rearing period. For each herd, the profit associated with each of the three methods of selection was simulated. The value of the genetic information and perfect information were the differences in herd profits of genetic selection and ex poste selection relative to random selection, respectively. The difference in value of the genetic information between the end of the rearing period and the beginning of the rearing period was the increase in value of the genetic information due to updating. The value of information was calculated as the average herd profit per replacement. The value of the genetic information ranged from 22 dollars/replacement to 30 dollars/replacement and was statistically greater than zero at a 95% confidence level. It is unclear whether this value is sufficient to prompt producers to select replacements on the basis of EBV milk as has been recommended. The negative value of EBV milk (from the end of the rearing period when selecting 80% of the replacements) for 32 herds was consistent with the noisiness of the genetic estimates as messages of ELPCOC. The increased value of the genetic information due to updating was approximately 5 dollars/replacement. This increased value is likely insufficient to warrant delaying replacement selection decisions solely to obtain the updated information. The value of EBV milk was approximately 4 dollars/replacement higher when selecting 70% of the replacements versus 80%. The genetic information captured between 15% (selecting 70% at the beginning of the rearing period) and 20% (selecting 80% at the end of the rearing period) of the value of perfect information.

Hereditary hemochromatosis as a risk factor for joint replacement surgery.

PubMed

Sahinbegovic, Enijad; Dallos, Tomás; Aigner, Elmar; Axmann, Roland; Engelbrecht, Matthias; Schöniger-Hekele, Maximilian; Karonitsch, Thomas; Farkas, Martin; Karger, Thomas; Willeit, Johann; Stölzel, Ulrich; Keysser, Gernot; Datz, Christian; Kiechl, Stefan; Schett, Georg; Zwerina, Jochen

2010-07-01

Hemochromatosis is an inherited disease with iron overload and joint involvement resembling osteoarthritis. To determine the rate of joint replacement surgery in patients with hemochromatosis, we performed a cross-sectional cohort study. A total of 199 individuals with hereditary hemochromatosis were included. The prevalence of joint replacement surgery in hip, knee, and ankle joints because of secondary osteoarthritis was assessed. Data were compared with 917 healthy subjects from the population-based Bruneck study. A total of 32 of 199 individuals with hemochromatosis received joint replacement surgery with a total number of 52 joints replaced. Compared with expected rates in healthy individuals, patients with hemochromatosis had a significantly higher risk for joint replacement surgery (odds ratio 9.0; confidence interval, 4.6-17.4). Joint replacement occurred significantly earlier in life in patients with hemochromatosis; 21.9% of the patients with hemochromatosis and 1.7% of healthy individuals required joint replacement before the age of 50 years (P=.0027). Moreover, patients with hemochromatosis were more likely to require multiple joint replacements (8.5%) than the control group (expected rate 0.3%; P=.0001). Hemochromatosis is a risk factor for joint replacement surgery because of severe secondary osteoarthritis. Copyright 2010 Elsevier Inc. All rights reserved.

Primary hypothyroidism in the community: Lower daily dosages of levothyroxine replacement therapy for Asian patients.

PubMed

Tan, Ngiap Chuan; Chew, Rong Quan; Koh, Yi Ling Eileen; Subramanian, Reena Chandini; Sankari, Usha; Meyappan, Meykkumar; Cho, Li Wei

2017-02-01

The goal of treatment in patients with primary hypothyroidism is to attain euthyroidism guided by the stipulated thyroid-stimulating hormone (TSH) levels range so as to minimize any potential long-term adverse effects. However, various factors may result in their Levothyroxine (T4) under and over-replacement.Our study aimed to evaluate the mean daily dose of L-T4 replacement for Asian patients with primary hypothyroidism. The secondary aims were to determine the proportion of those who were either over or under-replaced, and the factors associated with their thyroid function status and replacement adherence.Data collected using questionnaire survey from targeted patients managed in a typical public primary care center in Singapore: socio-demographic characteristics, clinical parameters, laboratory investigations, mean daily L-T4-replacement doses, and replacement regimens. The thyroid status of patients was classified based on thyroid function investigations.Complete data of 229 patients were analyzed. A total of 59.8% of patients had TSH within the normal range, 27.5% and 12.7% were under and over-replaced, respectively. About 60% of Asian patients with primary hypothyroidism achieved normal TSH status requiring average of 1.1 μg of daily L-T4/kgBW (kg body weight). Subjects who were over-replaced had a higher daily L-T4 dose/kgBW when compared to the euthyroid and the under replaced groups. Those with L-T4 over-replacement were largely due to excessive dosage. Patients who were younger, from lower socioeconomic strata, and higher BMI were more likely to be over or under-replaced.Majority of Asian patients with hypothyroidism required replacement of 1.1 μg of daily L-T4/kgBW. Their thyroid status was influenced by demographic and dosing factors.

Adjacent level effects of bi level disc replacement, bi level fusion and disc replacement plus fusion in cervical spine--a finite element based study.

PubMed

Faizan, Ahmad; Goel, Vijay K; Biyani, Ashok; Garfin, Steven R; Bono, Christopher M

2012-03-01

Studies delineating the adjacent level effect of single level disc replacement systems have been reported in literature. The aim of this study was to compare the adjacent level biomechanics of bi-level disc replacement, bi-level fusion and a construct having adjoining level disc replacement and fusion system. In total, biomechanics of four models- intact, bi level disc replacement, bi level fusion and fusion plus disc replacement at adjoining levels- was studied to gain insight into the effects of various instrumentation systems on cranial and caudal adjacent levels using finite element analysis (73.6N+varying moment). The bi-level fusion models are more than twice as stiff as compared to the intact model during flexion-extension, lateral bending and axial rotation. Bi-level disc replacement model required moments lower than intact model (1.5Nm). Fusion plus disc replacement model required moment 10-25% more than intact model, except in extension. Adjacent level motions, facet loads and endplate stresses increased substantially in the bi-level fusion model. On the other hand, adjacent level motions, facet loads and endplate stresses were similar to intact for the bi-level disc replacement model. For the fusion plus disc replacement model, adjacent level motions, facet loads and endplate stresses were closer to intact model rather than the bi-level fusion model, except in extension. Based on our finite element analysis, fusion plus disc replacement procedure has less severe biomechanical effects on adjacent levels when compared to bi-level fusion procedure. Bi-level disc replacement procedure did not have any adverse mechanical effects on adjacent levels. Copyright © 2011 Elsevier Ltd. All rights reserved.

The influence of carbohydrate-based fat replacers with and without emulsifiers on the quality characteristics of lowfat cake.

PubMed

Khalil, A H

1998-01-01

Physical and sensory characteristics of cakes prepared with either the carbohydrate-based fat replacers N-Flate, Paselli MD 10 and Litesse (0, 25, 50 and 75% of fat weight) or fat replacers plus emulsifier (mono- and diglycerides; 0 and 3% of flour weight) were studied. Specific gravity of the batter was significantly (p < or = 0.05) improved by using the carbohydrate-based fat replacers, especially at the 25 and 50% replacement levels. The combination of the emulsifier with either Paselli MD 10 or Litesse also enhanced the specific gravity. Cakes prepared with fat replacers at the 25 and 50% levels had higher volumes, specific volume and standing heights than those of the control. Cakes prepared with fat replacers at the 25, 50 and 75% levels were more compressible than the control. Cakes prepared with Paselli MD 10 had the highest volumes, specific volume, standing heights and compressibilities. Incorporation of emulsifier with fat replacers improved cake volumes, standing heights and compressibilities. Cakes prepared with fat replacers exhibited higher crust and crumb color values compared to the control. Cakes prepared with 25 or 50% fat replacers had higher mean scores for flavor, softness and eating quality than the control. Incorporation of emulsifier with fat replacers did not affect the crust color, crumb color and flavor, but significantly (p < or = 0.05) improved softness and eating quality.

Short communication: Effects of increasing protein and energy in the milk replacer with or without direct-fed microbial supplementation on growth and performance of preweaned Holstein calves.

PubMed

Geiger, A J; Ward, S H; Williams, C C; Rude, B J; Cabrera, C J; Kalestch, K N; Voelz, B E

2014-11-01

Forty-four Holstein calves were fed a direct-fed microbial (DFM) and 1 of 2 milk replacers to evaluate calf performance and growth. Treatments were (1) a control milk replacer [22:20; 22% crude protein (CP) and 20% fat], (2) an accelerated milk replacer (27:10; 27% CP and 10% fat), (3) the control milk replacer with added DFM (22:20+D), and (4) the accelerated milk replacer with added DFM (27:10+D). Dry matter intake, rectal temperatures, respiration scores and rates, and fecal scores were collected daily. Body weight, hip and withers height, heart girth, blood, and rumen fluid samples were collected weekly. Effects of treatment, sex, week, and their interactions were analyzed. Calves fed an accelerated milk replacer, regardless of DFM supplementation, consumed more CP and metabolizable energy in the milk replacer. No treatment differences were found for starter intake or intake of neutral detergent fiber or acid detergent fiber in the starter. Calves fed the accelerated milk replacer had greater preweaning and weaning body weight compared with calves fed the control milk replacer. Average daily gain was greater during the preweaning period for calves fed the accelerated milk replacer, but the same pattern did not hold true during the postweaning period. Feed efficiency did not differ among treatments. Hip height tended to be and withers height and heart girth were greater at weaning for calves fed the accelerated milk replacer compared with calves fed the control milk replacer. Fecal scores were greatest in calves fed DFM. Overall acetate, propionate, butyrate, and n-valerate concentrations were lower in calves fed the accelerated milk replacer, but DFM did not have an effect. Rumen pH was not different. Blood metabolites were unaffected by DFM supplementation, but calves fed the accelerated milk replacer had increased partial pressure of CO2, bicarbonate, and total bicarbonate in the blood. Direct-fed microbial supplementation did not appear to benefit the calf in this trial. Copyright © 2014 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Menopausal Symptom Relief and Side Effects Experienced by Women Using Compounded Bioidentical Hormone Replacement Therapy and Synthetic Conjugated Equine Estrogen and/or Progestin Hormone Replacement Therapy, Part 2.

PubMed

Deleruyelle, Laura J

2016-01-01

The use of compounded bioidentical hormone replacement therapy by menopausal women has become a popular alternative to traditional synthetic conjugated equine estrogen and progestin hormone replacement therapy due to safety concerns raised by recent studies. However, due to the lack of randomized, large-scale trials to evaluate the efficacy and side-effect profile of compounded bioidentical hormone replacement therapy many healthcare providers are reluctant to prescribe such therapy. The purpose of this study was to compare women's menopausal symptom relief and side effects experienced when using compounded bioidentical hormone replacement therapy and traditional hormone replacement therapy. A descriptive comparative design was used. Inferential and descriptive statistical procedures including a paired difference t-test, two-sample t-test, and f-tests (percentage, mean, standard deviation, frequency) were run on the Statistical Package for the Social Sciences. The framework used to guide this study was Lenz and Pugh's Theory of Unpleasant Symptoms. Surveys were distributed once to a convenient sample of women aged 35 and older when they dropped off or picked up their prescriptions at a pharmacy. Of the 216 surveys distributed, 70 were returned from those women taking compounded bioidentical hormone replacement therapy and 53 from traditional hormone replacement therapy. The survey contained 15 questions pertaining to age, duration of hormone replacement therapy, type and formulation of hormone replacement therapy, reasons for initiating hormone replacement therapy, symptoms before and one month after hormone replacement therapy, and side effects related to hormone replacement therapy. Included in part 1 of this series of articles was the introduction to the study conducted and the results of the literature review that was conducted for the purpose of examining the current data related to the topic of hormone replacement therapy. Part 2 provides a brief discussion on the significance of this study to nursing and provides the methods used in this study. The results of this study will be summarized in forthcoming articles in this series. Copyright© by International Journal of Pharmaceutical Compounding, Inc.

Menopausal Symptom Relief and Side Effects Experienced by Women Using Compounded Bioidentical Hormone Replacement Therapy and Synthetic Conjugated Equine Estrogen and/or Progestin Hormone Replacement Therapy, Part 3.

PubMed

Deleruyelle, Laura J

2017-01-01

The use of compounded bioidentical hormone replacement therapy by menopausal women has become a popular alternative to traditional synthetic conjugated equine estrogen and progestin hormone replacement therapy due to safety concerns raised by recent studies. However, due to the lack of randomized, large-scale trials to evaluate the efficacy and side-effect profile of compounded bioidentical hormone replacement therapy many healthcare providers are reluctant to prescribe such therapy. The purpose of this study was to compare women's menopausal symptom relief and side effects experienced when using compounded bioidentical hormone replacement therapy and traditional hormone replacement therapy. A descriptive comparative design was used. Inferential and descriptive statistical procedures including a paired difference t-test, two-sample t-test, and f-tests (percentage, mean, standard deviation, frequency) were run on the Statistical Package for the Social Sciences. The framework used to guide this study was Lenz and Pugh's Theory of Unpleasant Symptoms. Surveys were distributed once to a convenient sample of women aged 35 and older when they dropped off or picked up their prescriptions at a pharmacy. Of the 216 surveys distributed, 70 were returned from those women taking compounded bioidentical hormone replacement therapy and 53 from traditional hormone replacement therapy. The survey contained 15 questions pertaining to age, duration of hormone replacement therapy, type and formulation of hormone replacement therapy, reasons for initiating hormone replacement therapy, symptoms before and one month after hormone replacement therapy, and side effects related to hormone replacement therapy. Included in part 1 of this series of articles was the introduction to the study conducted and the results of the literature review that was conducted for the purpose of examining the current data related to the topic of hormone replacement therapy. Part 2 provided a brief discussion on the significance of this study to nursing and provided the methods used in this study. The results and conclusion of this study are provided within this article. Copyright© by International Journal of Pharmaceutical Compounding, Inc.

VH Replacement Footprint Analyzer-I, a Java-Based Computer Program for Analyses of Immunoglobulin Heavy Chain Genes and Potential VH Replacement Products in Human and Mouse

PubMed Central

Huang, Lin; Lange, Miles D.; Zhang, Zhixin

2014-01-01

VH replacement occurs through RAG-mediated secondary recombination between a rearranged VH gene and an upstream unrearranged VH gene. Due to the location of the cryptic recombination signal sequence (cRSS, TACTGTG) at the 3′ end of VH gene coding region, a short stretch of nucleotides from the previous rearranged VH gene can be retained in the newly formed VH–DH junction as a “footprint” of VH replacement. Such footprints can be used as markers to identify Ig heavy chain (IgH) genes potentially generated through VH replacement. To explore the contribution of VH replacement products to the antibody repertoire, we developed a Java-based computer program, VH replacement footprint analyzer-I (VHRFA-I), to analyze published or newly obtained IgH genes from human or mouse. The VHRFA-1 program has multiple functional modules: it first uses service provided by the IMGT/V-QUEST program to assign potential VH, DH, and JH germline genes; then, it searches for VH replacement footprint motifs within the VH–DH junction (N1) regions of IgH gene sequences to identify potential VH replacement products; it can also analyze the frequencies of VH replacement products in correlation with publications, keywords, or VH, DH, and JH gene usages, and mutation status; it can further analyze the amino acid usages encoded by the identified VH replacement footprints. In summary, this program provides a useful computation tool for exploring the biological significance of VH replacement products in human and mouse. PMID:24575092

Importance of milk replacer intake and composition in rearing orphan foals

PubMed Central

Cymbaluk, Nadia F.; Smart, Marion E.; Bristol, Frank M.; Pouteaux, Victor A.

1993-01-01

Effects of milk replacer composition and intake on the growth of orphan foals were evaluated. Twenty foals were assigned to four treatments: 1) mare-nursed, 2) commercial foal milk replacer at recommended intakes (standard), 3) commercial foal milk replacer at high intakes (high), and 4) acidified replacer at recommended intakes (acidified). Foals fed milk replacer diets were weaned at 12-24 hours postpartum and fed milk replacer for 50 days. Mare-nursed foals were weaned between 52 and 56 days of age. Foals fed replacer diets gained 12% to 28% less weight than mare-nursed foals up to two weeks of age. However, by four months of age, weights of replacer-fed foals were similar to those of mare-nursed foals and 32 other mare-nursed foals at the farm weaned between three and four months postparium. Foals drank 10 to 12 L/100 kg body weight (BW) in fluid replacer daily over the trial period. During the first week, high intake foals consumed 26% more replacer (p<0.05) than foals fed acidified or standard diets. This higher intake resulted in diarrhea earlier (6-11 days vs 11-22 days) and for a longer time (6.3 days vs 2.5-3.6 days) than in foals fed recommended amounts. Mare-nursed foals developed “foal heat scours” in the second week postpartum. After the first week, foals fed high replacer diet voluntarily consumed the same volume of fluid replacer as foals fed the standard intake. Foals ate less than 1 kg grain mix/100 kg BW daily to one month of age, then increased intake to 1.5-2 kg/ 100 kg BW to weaning. Water intake was 20-40% of daily fluid intake and was correlated (r = 0.85) to dry matter intake. Foals in the high intake group ate less (p<0.05) solid feed and drank less water than foals fed the standard and acidified diets. The foal's stomach capacity appears to limit meal size and thus replacer intake. If recommended feeding intervals are used, replacer intakes by foals are less than 15% BW daily. High volume intakes appeared to prolong diarrhea. Normal growth rates occur when replacer and good-quality feeds are fed concurrently. PMID:17424268

Semantic Factors Predict the Rate of Lexical Replacement of Content Words

PubMed Central

Vejdemo, Susanne; Hörberg, Thomas

2016-01-01

The rate of lexical replacement estimates the diachronic stability of word forms on the basis of how frequently a proto-language word is replaced or retained in its daughter languages. Lexical replacement rate has been shown to be highly related to word class and word frequency. In this paper, we argue that content words and function words behave differently with respect to lexical replacement rate, and we show that semantic factors predict the lexical replacement rate of content words. For the 167 content items in the Swadesh list, data was gathered on the features of lexical replacement rate, word class, frequency, age of acquisition, synonyms, arousal, imageability and average mutual information, either from published databases or gathered from corpora and lexica. A linear regression model shows that, in addition to frequency, synonyms, senses and imageability are significantly related to the lexical replacement rate of content words–in particular the number of synonyms that a word has. The model shows no differences in lexical replacement rate between word classes, and outperforms a model with word class and word frequency predictors only. PMID:26820737

The Effect on Long-Term Survivorship of Surgeon Preference for Posterior-Stabilized or Minimally Stabilized Total Knee Replacement: An Analysis of 63,416 Prostheses from the Australian Orthopaedic Association National Joint Replacement Registry.

PubMed

Vertullo, Christopher J; Lewis, Peter L; Lorimer, Michelle; Graves, Stephen E

2017-07-05

Controversy still exists as to the optimum management of the posterior cruciate ligament (PCL) in total knee arthroplasty. Surgeons can choose to kinematically substitute the PCL with a posterior-stabilized total knee replacement or alternatively to utilize a cruciate-retaining, also known as minimally stabilized, total knee replacement. Proponents of posterior-stabilized total knee replacement propose that the reported lower survivorship in registries when directly compared with minimally stabilized total knee replacement is due to confounders such as selection bias because of the preferential usage of posterior-stabilized total knee replacement in more complex or severe cases. In this study, we aimed to eliminate these possible confounders by performing an instrumental variable analysis based on surgeon preference to choose either posterior-stabilized or minimally stabilized total knee replacement, rather than the actual prosthesis received. Cumulative percent revision, hazard ratio (HR), and revision diagnosis data were obtained from the Australian Orthopaedic Association National Joint Replacement Registry from September 1, 1999, to December 31, 2014, for 2 cohorts of patients, those treated by high-volume surgeons who preferred minimally stabilized replacements and those treated by high-volume surgeons who preferred posterior-stabilized replacements. All patients had a diagnosis of osteoarthritis and underwent fixed-bearing total knee replacement with patellar resurfacing. At 13 years, the cumulative percent revision was 5.0% (95% confidence interval [CI], 4.0% to 6.2%) for the surgeons who preferred the minimally stabilized replacements compared with 6.0% (95% CI, 4.2% to 8.5%) for the surgeons who preferred the posterior-stabilized replacements. The revision risk for the surgeons who preferred posterior-stabilized replacements was significantly higher for all causes (HR = 1.45 [95% CI, 1.30 to 1.63]; p < 0.001), for loosening or lysis (HR = 1.93 [95% CI, 1.58 to 2.37]; p < 0.001), and for infection (HR = 1.51 [95% CI, 1.25 to 1.82]; p < 0.001). This finding was irrespective of patient age and was evident with cemented fixation and with both cross-linked polyethylene and non-cross-linked polyethylene. However, the higher revision risk was only evident in male patients. There was a 45% higher risk of revision for the patients of surgeons who preferred a posterior-stabilized total knee replacement compared with the patients of surgeons who preferred a minimally stabilized total knee replacement. Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Kinetics of methane hydrate replacement with carbon dioxide and nitrogen gas mixture using in situ NMR spectroscopy.

PubMed

Cha, Minjun; Shin, Kyuchul; Lee, Huen; Moudrakovski, Igor L; Ripmeester, John A; Seo, Yutaek

2015-02-03

In this study, the kinetics of methane replacement with carbon dioxide and nitrogen gas in methane gas hydrate prepared in porous silica gel matrices has been studied by in situ (1)H and (13)C NMR spectroscopy. The replacement process was monitored by in situ (1)H NMR spectra, where about 42 mol % of the methane in the hydrate cages was replaced in 65 h. Large amounts of free water were not observed during the replacement process, indicating a spontaneous replacement reaction upon exposing methane hydrate to carbon dioxide and nitrogen gas mixture. From in situ (13)C NMR spectra, we confirmed that the replacement ratio was slightly higher in small cages, but due to the composition of structure I hydrate, the amount of methane evolved from the large cages was larger than that of the small cages. Compositional analysis of vapor and hydrate phases was also carried out after the replacement reaction ceased. Notably, the composition changes in hydrate phases after the replacement reaction would be affected by the difference in the chemical potential between the vapor phase and hydrate surface rather than a pore size effect. These results suggest that the replacement technique provides methane recovery as well as stabilization of the resulting carbon dioxide hydrate phase without melting.

Generator replacement is associated with an increased rate of ICD lead alerts.

PubMed

Lovelock, Joshua D; Cruz, Cesar; Hoskins, Michael H; Jones, Paul; El-Chami, Mikhael F; Lloyd, Michael S; Leon, Angel; DeLurgio, David B; Langberg, Jonathan J

2014-10-01

Lead malfunction is an important cause of morbidity and mortality in patients with an implantable cardioverter-defibrillator (ICD). We have shown that the failure of recalled high-voltage leads significantly increases after ICD generator replacement. However, generator replacement has not been recognized as a predictor of lead failure in general. The purpose of this study is to assess the effect of ICD generator exchange on the rate of ICD lead alerts. A time-dependent Cox proportional hazards model was used to analyze a database of remotely monitored ICDs. The model assessed the impact of generator exchange on the rate of lead alerts after ICD generator replacement. The analysis included 60,219 patients followed for 37 ± 19 months. The 5-year lead survival was 99.3% (95% confidence interval 99.2%-99.4%). Of 60,219 patients, 7458 patients (12.9%) underwent ICD generator exchange without lead replacement. After generator replacement, the rate of lead alerts was more than 5-fold higher than in controls with leads of the same age without generator replacement (hazard ratio 5.19; 95% confidence interval 3.45-7.84). A large number of lead alerted within 3 months of generator replacement. Lead alerts were more common in patients with single- vs dual-chamber ICDs and in younger patients. Sex was not associated with lead alerts. Routine generator replacement is associated with a 5-fold higher risk of lead alert compared to age-matched leads without generator replacement. This suggests the need for intense surveillance after generator replacement and the development of techniques to minimize the risk of lead damage during generator replacement. Copyright © 2014 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Permanent Quadriplegia Following Replacement of Voice Prosthesis.

PubMed

Ozturk, Kayhan; Erdur, Omer; Kibar, Ertugrul

2016-11-01

The authors presented a patient with quadriplegia caused by cervical spine abscess following voice prosthesis replacement. The authors present the first reported permanent quadriplegia patient caused by voice prosthesis replacement. The authors wanted to emphasize that life-threatening complications may be faced during the replacement of voice prosthesis. Care should be taken during the replacement of voice prosthesis and if some problems have been faced during the procedure patients must be followed closely.

Validating Future Force Performance Measures (Army Class): Reclassification Test and Criterion Development

DTIC Science & Technology

2009-09-01

Replace CV boot assembly. 11 Replace propeller shafts , universal joints, and center bearings. 11 Replace front axle spindle . 5 Replace...propeller shafts , universal joints, and center bearings. (SL1/2) 12 Troubleshoot axles. (SL1/2) 11 Replace front axle spindle . (SL1/2) 6...Social Sciences. NOTE: The findings in this report are not to be construed as an official Department of the Army position, unless so designated by

23 CFR 650.407 - Application for bridge replacement or rehabilitation.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 23 Highways 1 2011-04-01 2011-04-01 false Application for bridge replacement or rehabilitation... ENGINEERING AND TRAFFIC OPERATIONS BRIDGES, STRUCTURES, AND HYDRAULICS Highway Bridge Replacement and Rehabilitation Program § 650.407 Application for bridge replacement or rehabilitation. (a) Agencies participate...

23 CFR 650.411 - Procedures for bridge replacement and rehabilitation projects.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 23 Highways 1 2011-04-01 2011-04-01 false Procedures for bridge replacement and rehabilitation... ENGINEERING AND TRAFFIC OPERATIONS BRIDGES, STRUCTURES, AND HYDRAULICS Highway Bridge Replacement and Rehabilitation Program § 650.411 Procedures for bridge replacement and rehabilitation projects. (a) Consideration...

23 CFR 650.411 - Procedures for bridge replacement and rehabilitation projects.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 23 Highways 1 2010-04-01 2010-04-01 false Procedures for bridge replacement and rehabilitation... ENGINEERING AND TRAFFIC OPERATIONS BRIDGES, STRUCTURES, AND HYDRAULICS Highway Bridge Replacement and Rehabilitation Program § 650.411 Procedures for bridge replacement and rehabilitation projects. (a) Consideration...

23 CFR 650.407 - Application for bridge replacement or rehabilitation.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 23 Highways 1 2010-04-01 2010-04-01 false Application for bridge replacement or rehabilitation... ENGINEERING AND TRAFFIC OPERATIONS BRIDGES, STRUCTURES, AND HYDRAULICS Highway Bridge Replacement and Rehabilitation Program § 650.407 Application for bridge replacement or rehabilitation. (a) Agencies participate...

[Clinical study on patellar replacement in total knee arthroplasty].

PubMed

Bao, Liang; Gao, Zhihui; Shi, Xiaoqiang; Fang, Xiaomin; Jin, Qunhua

2013-01-01

To evaluate the influence of patellar replacement on total knee arthroplasty by comparing with non patellar replacement. Between September 2010 and November 2010, 63 patients (63 knees) with osteoarthritis who met the selection criteria and underwent total knee arthroplasty, were randomly divided into 2 groups: patellar replacement in 32 cases (replacement group), non patellar replacement in 31 cases (non patellar replacement group). There was no significant difference in gender, age, disease duration, osteoarthritis grading, the clinical and functional scores of American Knee Society Score (KSS), the patellar tilt angle, tibiofemoral angle, and patellar ligament ratio between 2 groups (P > 0.05), they were comparable. After 6 weeks, 3, 6, and 12 months of operation, clinical and imaging evaluation methods were used to assessment the effectiveness. Primary healing of incision was obtained in all patients of 2 groups. Deep venous thrombosis occurred in 6 cases of replacement group and in 8 cases of non patellar replacement group. All patients were followed up 12 months. The postoperative incidence of anterior knee pain in replacement group was significantly lower than that in non patellar replacement group (P < 0.05) at 3, 6, and 12 months after operation. No significant difference was found in the postoperative KSS clinical score between 2 groups at each time point (P > 0.05). The joint function score of the replacement group was significantly higher than that of the non patellar replacement group at the other time point (P < 0.05) except the score at 6 weeks and 3 months. Significant difference was found in the patella score between 2 groups at 12 months (P < 0.05), but no significant difference at the other time points (P > 0.05). X-ray film showed no patellar fracture and dislocation, or loosening and breakage of internal fixation. At 12 months after operation, the tibiofemoral angle, the patellar ligament ratio, and the patellar tilt angle showed no significant difference between 2 groups (P > 0.05). Patella replacement can improve knee function score and the patella score, and reduce the incidence of postoperative anterior knee pain.

COMPUTER AIDED DESIGN OF REPLACEMENT SOLVENTS UNDER VARYING ENVIRONMENTAL CONSTRAINTS

EPA Science Inventory

There is a great need to replace many solvents that are commonly used by industry and the public, but whose continued use entails a number of human health and environmental risks. One problem hampering solvent replacement is the thought that replacement, particularly for environm...

22 CFR 51.10 - Replacement passports.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 22 Foreign Relations 1 2013-04-01 2013-04-01 false Replacement passports. 51.10 Section 51.10 Foreign Relations DEPARTMENT OF STATE NATIONALITY AND PASSPORTS PASSPORTS General § 51.10 Replacement passports. A passport issuing office may issue a replacement passport without payment of applicable fees for...

22 CFR 51.10 - Replacement passports.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 22 Foreign Relations 1 2011-04-01 2011-04-01 false Replacement passports. 51.10 Section 51.10 Foreign Relations DEPARTMENT OF STATE NATIONALITY AND PASSPORTS PASSPORTS General § 51.10 Replacement passports. A passport issuing office may issue a replacement passport without payment of applicable fees for...

22 CFR 51.10 - Replacement passports.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 22 Foreign Relations 1 2014-04-01 2014-04-01 false Replacement passports. 51.10 Section 51.10 Foreign Relations DEPARTMENT OF STATE NATIONALITY AND PASSPORTS PASSPORTS General § 51.10 Replacement passports. A passport issuing office may issue a replacement passport without payment of applicable fees for...

22 CFR 51.10 - Replacement passports.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Replacement passports. 51.10 Section 51.10 Foreign Relations DEPARTMENT OF STATE NATIONALITY AND PASSPORTS PASSPORTS General § 51.10 Replacement passports. A passport issuing office may issue a replacement passport without payment of applicable fees for...

22 CFR 51.10 - Replacement passports.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 22 Foreign Relations 1 2012-04-01 2012-04-01 false Replacement passports. 51.10 Section 51.10 Foreign Relations DEPARTMENT OF STATE NATIONALITY AND PASSPORTS PASSPORTS General § 51.10 Replacement passports. A passport issuing office may issue a replacement passport without payment of applicable fees for...

40 CFR 1042.615 - Replacement engine exemption.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 34 2013-07-01 2013-07-01 false Replacement engine exemption. 1042.615... CONTROLS CONTROL OF EMISSIONS FROM NEW AND IN-USE MARINE COMPRESSION-IGNITION ENGINES AND VESSELS Special Compliance Provisions § 1042.615 Replacement engine exemption. For Category 1 and Category 2 replacement...

40 CFR 1042.615 - Replacement engine exemption.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 33 2014-07-01 2014-07-01 false Replacement engine exemption. 1042.615... CONTROLS CONTROL OF EMISSIONS FROM NEW AND IN-USE MARINE COMPRESSION-IGNITION ENGINES AND VESSELS Special Compliance Provisions § 1042.615 Replacement engine exemption. For Category 1 and Category 2 replacement...

21 CFR 870.3710 - Pacemaker repair or replacement material.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Pacemaker repair or replacement material. 870.3710... (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Prosthetic Devices § 870.3710 Pacemaker repair or replacement material. (a) Identification. A pacemaker repair or replacement material is an...

21 CFR 870.3710 - Pacemaker repair or replacement material.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Pacemaker repair or replacement material. 870.3710... (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Prosthetic Devices § 870.3710 Pacemaker repair or replacement material. (a) Identification. A pacemaker repair or replacement material is an...

21 CFR 870.3710 - Pacemaker repair or replacement material.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Pacemaker repair or replacement material. 870.3710... (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Prosthetic Devices § 870.3710 Pacemaker repair or replacement material. (a) Identification. A pacemaker repair or replacement material is an...

21 CFR 870.3710 - Pacemaker repair or replacement material.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Pacemaker repair or replacement material. 870.3710... (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Prosthetic Devices § 870.3710 Pacemaker repair or replacement material. (a) Identification. A pacemaker repair or replacement material is an...

Replacement Condition Detection of Railway Point Machines Using an Electric Current Sensor

PubMed Central

Sa, Jaewon; Choi, Younchang; Chung, Yongwha; Kim, Hee-Young; Park, Daihee; Yoon, Sukhan

2017-01-01

Detecting replacement conditions of railway point machines is important to simultaneously satisfy the budget-limit and train-safety requirements. In this study, we consider classification of the subtle differences in the aging effect—using electric current shape analysis—for the purpose of replacement condition detection of railway point machines. After analyzing the shapes of after-replacement data and then labeling the shapes of each before-replacement data, we can derive the criteria that can handle the subtle differences between “does-not-need-to-be-replaced” and “needs-to-be-replaced” shapes. On the basis of the experimental results with in-field replacement data, we confirmed that the proposed method could detect the replacement conditions with acceptable accuracy, as well as provide visual interpretability of the criteria used for the time-series classification. PMID:28146057

42 CFR 433.117 - Initial approval of replacement systems.

Code of Federal Regulations, 2010 CFR

2010-10-01

... and Information Retrieval Systems § 433.117 Initial approval of replacement systems. (a) A replacement system must meet all conditions of initial approval of a mechanized claims processing and information retrieval system. (b) The agency must submit a APD that includes— (1) The date the replacement system will...

48 CFR 908.7101-4 - Replacement of motor vehicles.

Code of Federal Regulations, 2014 CFR

2014-10-01

... vehicles. 908.7101-4 Section 908.7101-4 Federal Acquisition Regulations System DEPARTMENT OF ENERGY....7101-4 Replacement of motor vehicles. (a) The replacement of motor vehicles shall be in accordance with... Activities may arrange to sell, as exchange sales, used motor vehicles being replaced and to apply the...

14 CFR 21.9 - Replacement and modification articles.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Replacement and modification articles. 21.9... CERTIFICATION PROCEDURES FOR PRODUCTS AND PARTS General § 21.9 Replacement and modification articles. (a) If a person knows, or should know, that a replacement or modification article is reasonably likely to be...

14 CFR 21.9 - Replacement and modification articles.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Replacement and modification articles. 21.9... CERTIFICATION PROCEDURES FOR PRODUCTS AND PARTS General § 21.9 Replacement and modification articles. (a) If a person knows, or should know, that a replacement or modification article is reasonably likely to be...

14 CFR 21.9 - Replacement and modification articles.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Replacement and modification articles. 21.9... CERTIFICATION PROCEDURES FOR PRODUCTS AND PARTS General § 21.9 Replacement and modification articles. (a) If a person knows, or should know, that a replacement or modification article is reasonably likely to be...

14 CFR 21.9 - Replacement and modification articles.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Replacement and modification articles. 21.9... CERTIFICATION PROCEDURES FOR PRODUCTS AND PARTS General § 21.9 Replacement and modification articles. (a) If a person knows, or should know, that a replacement or modification article is reasonably likely to be...

14 CFR 21.9 - Replacement and modification articles.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Replacement and modification articles. 21.9... CERTIFICATION PROCEDURES FOR PRODUCTS AND PARTS General § 21.9 Replacement and modification articles. (a) If a person knows, or should know, that a replacement or modification article is reasonably likely to be...

21 CFR 870.3925 - Replacement heart valve.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Replacement heart valve. 870.3925 Section 870.3925...) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Prosthetic Devices § 870.3925 Replacement heart valve. (a) Identification. A replacement heart valve is a device intended to perform the function of any...

7 CFR 274.6 - Replacement issuances and cards to households.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 4 2014-01-01 2014-01-01 false Replacement issuances and cards to households. 274.6 Section 274.6 Agriculture Regulations of the Department of Agriculture (Continued) FOOD AND NUTRITION... Excessive Replacement Card Notice if they have chosen to exercise the option to withhold the replacement...

48 CFR 908.7101-4 - Replacement of motor vehicles.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 48 Federal Acquisition Regulations System 5 2011-10-01 2011-10-01 false Replacement of motor....7101-4 Replacement of motor vehicles. (a) The replacement of motor vehicles shall be in accordance with... Heads of Contracting Activities may arrange to sell, as exchange sales, used motor vehicles being...

40 CFR 85.1714 - Replacement-engine exemption.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 18 2010-07-01 2010-07-01 false Replacement-engine exemption. 85.1714... Vehicle Engines § 85.1714 Replacement-engine exemption. (a) Engine manufacturers may use the provisions of 40 CFR 1068.240 to exempt new replacement heavy-duty highway engines as specified in this section. (b...

23 CFR 710.509 - Functional replacement of real property in public ownership.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 23 Highways 1 2010-04-01 2010-04-01 false Functional replacement of real property in public... Functional replacement of real property in public ownership. (a) General. When publicly owned real property...) Federal participation. Federal-aid funds may participate in functional replacement costs only if: (1...

40 CFR 85.1714 - Replacement-engine exemption.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 19 2012-07-01 2012-07-01 false Replacement-engine exemption. 85.1714... Vehicle Engines § 85.1714 Replacement-engine exemption. (a) Engine manufacturers may use the provisions of 40 CFR 1068.240 to exempt new replacement heavy-duty highway engines as specified in this section. (b...

40 CFR 85.1714 - Replacement-engine exemption.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 19 2013-07-01 2013-07-01 false Replacement-engine exemption. 85.1714... Vehicle Engines § 85.1714 Replacement-engine exemption. (a) Engine manufacturers may use the provisions of 40 CFR 1068.240 to exempt new replacement heavy-duty highway engines as specified in this section. (b...

40 CFR 85.1714 - Replacement-engine exemption.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 18 2011-07-01 2011-07-01 false Replacement-engine exemption. 85.1714... Vehicle Engines § 85.1714 Replacement-engine exemption. (a) Engine manufacturers may use the provisions of 40 CFR 1068.240 to exempt new replacement heavy-duty highway engines as specified in this section. (b...

40 CFR 85.1714 - Replacement-engine exemption.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 19 2014-07-01 2014-07-01 false Replacement-engine exemption. 85.1714... Vehicle Engines § 85.1714 Replacement-engine exemption. (a) Engine manufacturers may use the provisions of 40 CFR 1068.240 to exempt new replacement heavy-duty highway engines as specified in this section. (b...

21 CFR 870.3925 - Replacement heart valve.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Replacement heart valve. 870.3925 Section 870.3925...) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Prosthetic Devices § 870.3925 Replacement heart valve. (a) Identification. A replacement heart valve is a device intended to perform the function of any...

21 CFR 870.3925 - Replacement heart valve.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Replacement heart valve. 870.3925 Section 870.3925...) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Prosthetic Devices § 870.3925 Replacement heart valve. (a) Identification. A replacement heart valve is a device intended to perform the function of any...

21 CFR 870.3925 - Replacement heart valve.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Replacement heart valve. 870.3925 Section 870.3925...) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Prosthetic Devices § 870.3925 Replacement heart valve. (a) Identification. A replacement heart valve is a device intended to perform the function of any...

21 CFR 870.3925 - Replacement heart valve.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Replacement heart valve. 870.3925 Section 870.3925...) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Prosthetic Devices § 870.3925 Replacement heart valve. (a) Identification. A replacement heart valve is a device intended to perform the function of any...

[Vitrectomy: in search of the ideal vitreous replacement].

PubMed

Steijns, Daan; Stilma, Jan S

2009-01-01

Pars plana vitrectomy is a form of surgery to remove the vitreous body. It is performed with various eye diseases. Replacement of the vitreous body is necessitated by its removal. After more than 50 years the search for the ideal vitreous replacement has not yet ended. Different materials are used to replace the vitreous body. The advantages, disadvantages and applications of those materials are discussed. The lack of a material to successfully replace the vitreous body is a significant restriction in the treatment vitreoretinal pathologies.

Operation and maintenance cost data for residential photovoltaic modules/panels

NASA Technical Reports Server (NTRS)

Oster, J. R., Jr.; Zaremski, D. R., Jr.; Albert, E. M.; Hawkins, S. L.

1980-01-01

Costs associated with the operation and maintenance of residential photovoltaic modules and arrays are studied. Six basic topics related to operation and maintenance to photovoltaic arrays are investigated: maintenance; cleaning; panel replacement; gasket repair/replacement; wiring repair/replacement; and termination repair/replacement. The effects of the mounting types (rack mount, stand off mount, direct mount and integral mount) and the installation/replacement type (sequential, partial interruption and independent) are identified and described. Methods of reducing maintenance costs are suggested.

Potentiality Prediction of Electric Power Replacement Based on Power Market Development Strategy

NASA Astrophysics Data System (ADS)

Miao, Bo; Yang, Shuo; Liu, Qiang; Lin, Jingyi; Zhao, Le; Liu, Chang; Li, Bin

2017-05-01

The application of electric power replacement plays an important role in promoting the development of energy conservation and emission reduction in our country. To exploit the potentiality of regional electric power replacement, the regional GDP (gross domestic product) and energy consumption are taken as potentiality evaluation indicators. The principal component factors are extracted with PCA (principal component analysis), and the integral potentiality analysis is made to the potentiality of electric power replacement in the national various regions; a region is taken as a research object, and the potentiality of electric power replacement is defined and quantified. The analytical model for the potentiality of multi-scenario electric power replacement is developed, and prediction is made to the energy consumption with the grey prediction model. The relevant theoretical research is utilized to realize prediction analysis on the potentiality amount of multi-scenario electric power replacement.

[Longterm results of mitral valve replacement (author's transl)].

PubMed

Erhard, W; Reichmann, M; Delius, W; Sebening, H; Herrmann, G

1977-04-22

210 patients were followed up by the actuary method for over 5 years after isolated mitral valve replacement or a double valve replacement. After isolated valve replacement the one month survival including the operative mortality was 92+/-2%. The survival after one year was 83+/-3% and after 5 years 66+/-7%. The five year survival of patients in preoperative class III (according to the NYHA) was 73+/-8% and of class IV 57+/-8% (P less than or equal to 0.1). A comparison of valve replacements for pure mitral stenosis or mitral insufficiency showed no statistically significant differences. In the 37 patients who had a double valve replacement the survival risk was not increased in comparison with those patients who had had a single valve replacement. Age above 45 years and a preoperative markedly raised pulmonary arteriolar resistance reduced the chances of survival.

23 CFR 661.19 - When is a bridge eligible for replacement?

Code of Federal Regulations, 2011 CFR

2011-04-01

... 23 Highways 1 2011-04-01 2011-04-01 false When is a bridge eligible for replacement? 661.19... TRAFFIC OPERATIONS INDIAN RESERVATION ROAD BRIDGE PROGRAM § 661.19 When is a bridge eligible for replacement? To be eligible for replacement, the bridge must be considered structurally deficient or...

40 CFR 74.47 - Transfer of allowances from the replacement of thermal energy-combustion sources.

Code of Federal Regulations, 2010 CFR

2010-07-01

... replacement of thermal energy-combustion sources. 74.47 Section 74.47 Protection of Environment ENVIRONMENTAL...—combustion sources. (a) Thermal energy plan—(1) General provisions. The designated representative of an opt... quarter the replacement unit(s) will replace thermal energy of the opt-in source; (ii) The name...

78 FR 19718 - Modifications To Labeling of Nicotine Replacement Therapy Products for Over-the-Counter Human Use

Federal Register 2010, 2011, 2012, 2013, 2014

2013-04-02

...] Modifications To Labeling of Nicotine Replacement Therapy Products for Over-the-Counter Human Use AGENCY: Food...-counter nicotine replacement therapy products, related to concomitant use with other nicotine-containing... over-the- counter nicotine replacement therapy products for their approved intended use as aids to...

43 CFR 4750.4-4 - Replacement animals.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 43 Public Lands: Interior 2 2012-10-01 2012-10-01 false Replacement animals. 4750.4-4 Section 4750... FREE-ROAMING HORSES AND BURROS Private Maintenance § 4750.4-4 Replacement animals. The authorized officer shall replace an animal, upon request by the adopter, if (a) within 6 months of the execution of...

43 CFR 4750.4-4 - Replacement animals.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 43 Public Lands: Interior 2 2011-10-01 2011-10-01 false Replacement animals. 4750.4-4 Section 4750... FREE-ROAMING HORSES AND BURROS Private Maintenance § 4750.4-4 Replacement animals. The authorized officer shall replace an animal, upon request by the adopter, if (a) within 6 months of the execution of...

43 CFR 4750.4-4 - Replacement animals.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 43 Public Lands: Interior 2 2013-10-01 2013-10-01 false Replacement animals. 4750.4-4 Section 4750... FREE-ROAMING HORSES AND BURROS Private Maintenance § 4750.4-4 Replacement animals. The authorized officer shall replace an animal, upon request by the adopter, if (a) within 6 months of the execution of...

43 CFR 4750.4-4 - Replacement animals.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 43 Public Lands: Interior 2 2014-10-01 2014-10-01 false Replacement animals. 4750.4-4 Section 4750... FREE-ROAMING HORSES AND BURROS Private Maintenance § 4750.4-4 Replacement animals. The authorized officer shall replace an animal, upon request by the adopter, if (a) within 6 months of the execution of...

46 CFR 59.01-5 - Repairs, replacements, or alterations.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 2 2013-10-01 2013-10-01 false Repairs, replacements, or alterations. 59.01-5 Section 59.01-5 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING REPAIRS TO BOILERS, PRESSURE VESSELS AND APPURTENANCES General Requirements § 59.01-5 Repairs, replacements, or alterations. (a) No repairs, replacements, or...

46 CFR 59.01-5 - Repairs, replacements, or alterations.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 2 2010-10-01 2010-10-01 false Repairs, replacements, or alterations. 59.01-5 Section 59.01-5 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING REPAIRS TO BOILERS, PRESSURE VESSELS AND APPURTENANCES General Requirements § 59.01-5 Repairs, replacements, or alterations. (a) No repairs, replacements, or...

46 CFR 59.01-5 - Repairs, replacements, or alterations.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 2 2011-10-01 2011-10-01 false Repairs, replacements, or alterations. 59.01-5 Section 59.01-5 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING REPAIRS TO BOILERS, PRESSURE VESSELS AND APPURTENANCES General Requirements § 59.01-5 Repairs, replacements, or alterations. (a) No repairs, replacements, or...

46 CFR 59.01-5 - Repairs, replacements, or alterations.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 2 2014-10-01 2014-10-01 false Repairs, replacements, or alterations. 59.01-5 Section 59.01-5 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING REPAIRS TO BOILERS, PRESSURE VESSELS AND APPURTENANCES General Requirements § 59.01-5 Repairs, replacements, or alterations. (a) No repairs, replacements, or...

46 CFR 59.01-5 - Repairs, replacements, or alterations.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 2 2012-10-01 2012-10-01 false Repairs, replacements, or alterations. 59.01-5 Section 59.01-5 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING REPAIRS TO BOILERS, PRESSURE VESSELS AND APPURTENANCES General Requirements § 59.01-5 Repairs, replacements, or alterations. (a) No repairs, replacements, or...

Do I Have to Learn Something New? Mental Models and the Acceptance of Replacement Technologies

ERIC Educational Resources Information Center

Zhang, Wei; Xu, Peng

2011-01-01

Few studies in technology acceptance have explicitly addressed the acceptance of replacement technologies, technologies that replace legacy ones that have been in use. This article explores this issue through the theoretical lens of mental models. We contend that accepting replacement technologies entails both mental model maintenance and mental…

9 CFR 82.15 - Replacement birds and poultry.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Replacement birds and poultry. 82.15...- EASE (END) AND CHLAMYDIOSIS Exotic Newcastle Disease (END) § 82.15 Replacement birds and poultry. Birds and poultry that have been destroyed because of a quarantine for END may not be replaced by birds or...

9 CFR 82.15 - Replacement birds and poultry.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 9 Animals and Animal Products 1 2011-01-01 2011-01-01 false Replacement birds and poultry. 82.15...- EASE (END) AND CHLAMYDIOSIS Exotic Newcastle Disease (END) § 82.15 Replacement birds and poultry. Birds and poultry that have been destroyed because of a quarantine for END may not be replaced by birds or...

The Salary Premium Required for Replacing Management Faculty: Evidence from a National Survey

ERIC Educational Resources Information Center

Finch, J. Howard; Allen, Richard S.; Weeks, H. Shelton

2010-01-01

One of the most important aspects of growing and improving business education is replacing departed faculty members. As the baby-boom generation approaches retirement, the supply of available replacement faculty members is diminishing. The result is a competitive market for replacement faculty that features increasing starting salary levels. In…

23 CFR 661.19 - When is a bridge eligible for replacement?

Code of Federal Regulations, 2010 CFR

2010-04-01

... 23 Highways 1 2010-04-01 2010-04-01 false When is a bridge eligible for replacement? 661.19... TRAFFIC OPERATIONS INDIAN RESERVATION ROAD BRIDGE PROGRAM § 661.19 When is a bridge eligible for replacement? To be eligible for replacement, the bridge must be considered structurally deficient or...

Contemporary experience with surgical treatment of aortic valve disease in children.

PubMed

Khan, Muhammad S; Samayoa, Andres X; Chen, Diane W; Petit, Christopher J; Fraser, Charles D

2013-09-01

Surgical treatment of aortic valve (AoV) disease in childhood involves complex decisions particularly in very small patients. There is no consensus regarding the optimum surgical option. The objective of this review was to analyze a contemporary experience of AoV surgery in a large children's hospital. A retrospective review of children (aged ≤ 18 years) undergoing AoV repair or replacement from June 1995 to December 2011 was carried out. A total of 285 AoV operations (97 repairs, 188 replacements) were performed on 241 patients. Hospital survival for repair was 98% and for replacements was 97%. At follow-up of repairs, there were 16 (17%) reoperations and 3 (3%) late deaths. Follow-up of AoV replacements demonstrated 31 (16%) reoperations (homograft 27, autograft 3, mechanical 1) and 8 (4%) late deaths (homograft 5, autograft 2, mechanical 1). Freedom from reintervention or death (FRD) was found to be lower in repairs for infants (P = .048) and truncal valves (P < .05). For AoV replacements, infants and patients who had concomitant CHD or homografts (P < .0001) had lower FRD. Cox regression analysis for AoV replacements identified infants and homograft root replacements at a higher risk for death/reoperation. AoV repairs and replacements were generally found to be associated with low death and reoperation rates at long-term follow-up. Infants had a lower freedom from reintervention or death after either an AoV repair or replacement, although truncal valve repairs and AoV replacement in patients with concomitant CHD were associated with lower valve survival. Among the valve options, homograft root replacement had a higher risk of death/reoperation and lowest freedom from reintervention or death. Copyright © 2013 The American Association for Thoracic Surgery. Published by Mosby, Inc. All rights reserved.

Replacement of Mushroom Cage Gastrostomy Tube Using a Modified Technique to Allow Percutaneous Replacement with an Endoscopic Tube in Patients with Amyotrophic Lateral Sclerosis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ammar, Thoraya; Rio, Alan; Ampong, Mary Ann

2010-06-15

Radiologic inserted gastrostomy (RIG) is the preferred method in our institution for enteral feeding in amyotrophic lateral sclerosis (ALS). Skin-level primary-placed mushroom cage gastrostomy tubes become tight with weight gain. We describe a minimally invasive radiologic technique for replacing mushroom gastrostomy tubes with endoscopic mushroom cage tubes in ALS. All patients with ALS who underwent replacement of a RIG tube were included. Patients were selected for a modified replacement when the tube length of the primary placed RIG tube was insufficient to allow like-for-like replacement. Replacement was performed under local anesthetic and fluoroscopic guidance according to a preset technique, withmore » modification of an endoscopic mushroom cage gastrostomy tube to allow percutaneous placement. Assessment of the success, safety, and durability of the modified technique was undertaken. Over a 60-month period, 104 primary placement mushroom cage tubes in ALS were performed. A total of 20 (19.2%) of 104 patients had a replacement tube positioned, 10 (9.6%) of 104 with the modified technique (male n = 4, female n = 6, mean age 65.5 years, range 48-85 years). All tubes were successfully replaced using this modified technique, with two minor complications (superficial wound infection and minor hemorrhage). The mean length of time of tube durability was 158.5 days (range 6-471 days), with all but one patient dying with a functional tube in place. We have devised a modification to allow percutaneous replacement of mushroom cage gastrostomy feeding tubes with minimal compromise to ALS patients. This technique allows tube replacement under local anesthetic, without the need for sedation, an important consideration in ALS.« less

Prevalence of Total Hip and Knee Replacement in the United States.

PubMed

Maradit Kremers, Hilal; Larson, Dirk R; Crowson, Cynthia S; Kremers, Walter K; Washington, Raynard E; Steiner, Claudia A; Jiranek, William A; Berry, Daniel J

2015-09-02

Descriptive epidemiology of total joint replacement procedures is limited to annual procedure volumes (incidence). The prevalence of the growing number of individuals living with a total hip or total knee replacement is currently unknown. Our objective was to estimate the prevalence of total hip and total knee replacement in the United States. Prevalence was estimated using the counting method by combining historical incidence data from the National Hospital Discharge Survey and the Healthcare Cost and Utilization Project (HCUP) State Inpatient Databases from 1969 to 2010 with general population census and mortality counts. We accounted for relative differences in mortality rates between those who have had total hip or knee replacement and the general population. The 2010 prevalence of total hip and total knee replacement in the total U.S. population was 0.83% and 1.52%, respectively. Prevalence was higher among women than among men and increased with age, reaching 5.26% for total hip replacement and 10.38% for total knee replacement at eighty years. These estimates corresponded to 2.5 million individuals (1.4 million women and 1.1 million men) with total hip replacement and 4.7 million individuals (3.0 million women and 1.7 million men) with total knee replacement in 2010. Secular trends indicated a substantial rise in prevalence over time and a shift to younger ages. Around 7 million Americans are living with a hip or knee replacement, and consequently, in most cases, are mobile, despite advanced arthritis. These numbers underscore the substantial public health impact of total hip and knee arthroplasties. Copyright © 2015 by The Journal of Bone and Joint Surgery, Incorporated.

Total ankle replacement systems available in the United States.

PubMed

Coetzee, J Chris; Deorio, James K

2010-01-01

Ankle replacement continues to be a viable option for treating patients with ankle arthritis. Over the past 10 years, there has been a significant increase in the number of ankle replacement systems available for use. Current controversy centers on whether fixed- or mobile-bearing devices are most advantageous. Most total ankle systems used outside the United States are mobile-bearing devices, whereas ankle replacement systems used in the United States are all essentially fixed-bearing devices. Not all ankles with degenerative changes are amenable to replacement surgery, and several exclusion criteria are well documented. Ankle replacement is especially complicated because of the ankle's proximity to the foot and the important role that the balance and alignment of the foot play in the success of the ankle replacement. Foot deformities should be treated before or at the time of ankle replacement surgery. Ignoring foot deformities can lead to failure of the ankle replacement. It is also of paramount importance to consider the stability of the ankle ligaments. An unstable ankle with a varus or valgus deformity of more than 20 degrees is probably not amenable to ankle replacement. There are currently no reliable options to predictably reconstruct the lateral or medial ligaments in these severe deformities. It is important to be aware of the ankle replacement systems currently available in the United States and understand the key features of each design. Devices approved by the US Food and Drug Administration, a device that is awaiting approval, and a device that is being evaluated by the Food and Drug Administration in a prospective randomized clinical trial are discussed, along with an objective comparison of fixed- and mobile-bearing devices.

On-line upgrade of program modules using AdaPT

NASA Technical Reports Server (NTRS)

Waldrop, Raymond S.; Volz, Richard A.; Smith, Gary W.; Goldsack, Stephen J.; Holzbach-Valero, A. A.

1993-01-01

One purpose of our research is the investigation of the effectiveness and expressiveness of AdaPT, a set of language extensions to Ada 83, for distributed systems. As a part of that effort, we are now investigating the subject of replacing, e.g. upgrading, software modules while the software system remains in operation. The AdaPT language extensions provide a good basis for this investigation for several reasons: they include the concept of specific, self-contained program modules which can be manipulated; support for program configuration is included in the language; and although the discussion will be in terms of the AdaPT language, the AdaPT to Ada 83 conversion methodology being developed as another part of this project will provide a basis for the application of our findings to Ada 83 and Ada 9X systems. The purpose of this investigation is to explore the basic mechanisms of the replacement process. With this purpose in mind, we will avoid including issues whose presence would obscure these basic mechanisms by introducing additional, unrelated concerns. Thus, while replacement in the presence of real-time deadlines, heterogeneous systems, and unreliable networks is certainly a topic of interest, we will first gain an understanding of the basic processes in the absence of such concerns. The extension of the replacement process to more complex situations can be made later. A previous report established an overview of the module replacement problem, a taxonomy of the various aspects of the replacement process, and a solution to one case in the replacement taxonomy. This report provides solutions to additional cases in the replacement process taxonomy: replacement of partitions with state and replacement of nodes. The solutions presented here establish the basic principles for module replacement. Extension of these solutions to other more complicated cases in the replacement taxonomy is direct, though requiring substantial work beyond the available funding.

Bilateral same-day endoscopic transcanal cartilage tympanoplasty: initial results.

PubMed

Daneshi, Ahmad; Jahandideh, Hesam; Daneshvar, Ali; Safdarian, Mahdi

Same-day closure of bilateral tympanic membrane perforations is a quick and more comfortable procedure for the patients. However, conventional bilateral same-day tympanoplasty or myringoplasty has been rarely performed because of the theoretical risk of postoperative complications. To evaluate the advantages and outcomes of bilateral simultaneous endoscopic cartilage tympanoplasty in patients with bilateral tympanic membrane perforations. From February 2012 to March 2013, patients with bilateral dry tympanic membrane perforations who had some degree of hearing loss corresponding to the size and location of the perforation entered the study. There was no suspicion to disrupted ossicular chain, mastoid involvement or other middle or inner ear pathology. Endoscopic transcanal cartilage tympanoplasty was done using the underlay (medial) technique. The graft was harvested from cymba cartilage in just one ear with preservation of perichondrium in one side. A 1.5cm×1.5cm cartilage seemed to be enough for tympanoplasty in both sides. Nine patients (4 males and 5 females) with the mean age of 37.9 years underwent bilateral transcanal cartilage tympanoplasty in a same-day surgery. The mean duration of follow up was 15.8 months. There were detected no complications including hearing loss, otorrhea and wound complication with no retraction pocket or displaced graft during follow-up period. The grafts take rate was 94.44% (only one case of unilateral incomplete closure). The mean of air-bone gap overall improved from 13.88dB preoperatively to 9.16dB postoperatively (p<0.05). Bilateral endoscopic transcanal cartilage tympanoplasty can be considered as a safe minimally invasive procedure that can be performed in a same-day surgery. It reduces the costs and operation time and is practical with a low rate of postoperative complications. Copyright © 2017 Associação Brasileira de Otorrinolaringologia e Cirurgia Cérvico-Facial. Published by Elsevier Editora Ltda. All rights reserved.

Separating the contributions of olivocochlear and middle ear muscle reflexes in modulation of distortion product otoacoustic emission levels.

PubMed

Wolter, Nikolaus E; Harrison, Robert V; James, Adrian L

2014-01-01

Mediated by the medial olivocochlear system (MOCS), distortion product otoacoustic emission (DPOAE) levels are reduced by presentation of contralateral acoustic stimuli. Such acoustic signals can also evoke a middle ear muscle reflex (MEMR) that also attenuates recorded DPOAE levels. Our aim is to clearly differentiate these two inhibitory mechanisms and to analyze each separately, perhaps allowing the development of novel tests of hearing function. DPOAE were recorded in real time from chinchillas with normal auditory brainstem response thresholds and middle ear function. Amplitude reduction and its onset latency caused by contralateral presentation of intermittent narrow-band noise (NBN) were measured. Stapedius and tensor tympani muscle tendons were divided without disturbing the ossicular chain, and DPOAE testing was repeated. Peak reduction of (2f1 - f2) DPOAE levels occurred when the center frequency of contralateral NBN approximated the primary tone f2, indicating an f2-frequency-specific response. For a 4.5-kHz centered NBN, DPOAE (f2 = 4.4 kHz) inhibition was 0.1 dB (p < 0.001). This response remained present after tendon division, consistent with an MOCS origin. Low-frequency NBN (center frequency: 0.5 kHz) reduced otoacoustic emission levels (0.1 dB, p < 0.001) across a wide range of DPOAE frequencies. This low-frequency response was abolished by division of the middle ear muscle tendons, clearly indicating MEMR involvement. Following middle ear muscle tendon division, DPOAE inhibition by contralateral stimuli approximating the primary tone f2 persists, whereas responses evoked by lower contralateral frequencies are abolished. This distinguishes the different roles of the MOCS (f2 frequency specific) and MEMR (low frequency only) in contralateral modulation of DPOAE. This analysis helps clarify the pathways involved in an objective test that might have clinical benefit in the testing of neonates.

A New Acoustic Portal into the Odontocete Ear and Vibrational Analysis of the Tympanoperiotic Complex

PubMed Central

Cranford, Ted W.; Krysl, Petr; Amundin, Mats

2010-01-01

Global concern over the possible deleterious effects of noise on marine organisms was catalyzed when toothed whales stranded and died in the presence of high intensity sound. The lack of knowledge about mechanisms of hearing in toothed whales prompted our group to study the anatomy and build a finite element model to simulate sound reception in odontocetes. The primary auditory pathway in toothed whales is an evolutionary novelty, compensating for the impedance mismatch experienced by whale ancestors as they moved from hearing in air to hearing in water. The mechanism by which high-frequency vibrations pass from the low density fats of the lower jaw into the dense bones of the auditory apparatus is a key to understanding odontocete hearing. Here we identify a new acoustic portal into the ear complex, the tympanoperiotic complex (TPC) and a plausible mechanism by which sound is transduced into the bony components. We reveal the intact anatomic geometry using CT scanning, and test functional preconceptions using finite element modeling and vibrational analysis. We show that the mandibular fat bodies bifurcate posteriorly, attaching to the TPC in two distinct locations. The smaller branch is an inconspicuous, previously undescribed channel, a cone-shaped fat body that fits into a thin-walled bony funnel just anterior to the sigmoid process of the TPC. The TPC also contains regions of thin translucent bone that define zones of differential flexibility, enabling the TPC to bend in response to sound pressure, thus providing a mechanism for vibrations to pass through the ossicular chain. The techniques used to discover the new acoustic portal in toothed whales, provide a means to decipher auditory filtering, beam formation, impedance matching, and transduction. These tools can also be used to address concerns about the potential deleterious effects of high-intensity sound in a broad spectrum of marine organisms, from whales to fish. PMID:20694149

A new acoustic portal into the odontocete ear and vibrational analysis of the tympanoperiotic complex.

PubMed

Cranford, Ted W; Krysl, Petr; Amundin, Mats

2010-08-04

Global concern over the possible deleterious effects of noise on marine organisms was catalyzed when toothed whales stranded and died in the presence of high intensity sound. The lack of knowledge about mechanisms of hearing in toothed whales prompted our group to study the anatomy and build a finite element model to simulate sound reception in odontocetes. The primary auditory pathway in toothed whales is an evolutionary novelty, compensating for the impedance mismatch experienced by whale ancestors as they moved from hearing in air to hearing in water. The mechanism by which high-frequency vibrations pass from the low density fats of the lower jaw into the dense bones of the auditory apparatus is a key to understanding odontocete hearing. Here we identify a new acoustic portal into the ear complex, the tympanoperiotic complex (TPC) and a plausible mechanism by which sound is transduced into the bony components. We reveal the intact anatomic geometry using CT scanning, and test functional preconceptions using finite element modeling and vibrational analysis. We show that the mandibular fat bodies bifurcate posteriorly, attaching to the TPC in two distinct locations. The smaller branch is an inconspicuous, previously undescribed channel, a cone-shaped fat body that fits into a thin-walled bony funnel just anterior to the sigmoid process of the TPC. The TPC also contains regions of thin translucent bone that define zones of differential flexibility, enabling the TPC to bend in response to sound pressure, thus providing a mechanism for vibrations to pass through the ossicular chain. The techniques used to discover the new acoustic portal in toothed whales, provide a means to decipher auditory filtering, beam formation, impedance matching, and transduction. These tools can also be used to address concerns about the potential deleterious effects of high-intensity sound in a broad spectrum of marine organisms, from whales to fish.

Factors Affecting Loss of Tympanic Membrane Mobility in Acute Otitis Media Model of Chinchilla

PubMed Central

Guan, Xiying; Chen, Yongzheng; Gan, Rong Z.

2014-01-01

Recently we reported that middle ear pressure (MEP), middle ear effusion (MEE), and ossicular changes each contribute to the loss of tympanic membrane (TM) mobility in a guinea pig model of acute otitis media (AOM) induced by S. pneumoniae (Guan and Gan, 2013). However, it is not clear how those factors vary along the course of the disease and whether those effects are reproducible in different species. In this study, a chinchilla AOM model was produced by transbullar injection of Haemophilus influenzae. Mobility of the TM at the umbo was measured by laser vibrometry in two treatment groups: 4 days (4D) and 8 days (8D) post inoculation. These time points represent relatively early and later phases of AOM. In each group, the vibration of the umbo was measured at three experimental stages: unopened, pressure-released, and effusion-removed ears. The effects of MEP and MEE and middle ear structural changes were quantified in each group by comparing the TM mobility at one stage with that of the previous stage. Our findings show that the factors affecting TM mobility do change with the disease time course. The MEP was the dominant contributor to reduction of TM mobility in 4D AOM ears, but showed little effect in 8D ears when MEE filled the tympanic cavity. MEE was the primary factor affecting TM mobility loss in 8D ears, but affected the 4D ears only at high frequencies. After the release of MEP and removal of MEE, residual loss of TM mobility was seen mainly at low frequencies in both 4D and 8D ears, and was associated with middle ear structural changes. Our findings establish that the factors contributing to TM mobility loss in the chinchilla ear were similar to those we reported previously for the guinea pig ears with AOM. Outcomes did not appear to differ between the two major bacterial species causing AOM in these animal models. PMID:24406734

Visualization of Middle Ear Ossicles in Elder Subjects with Ultra-short Echo Time MR Imaging.

PubMed

Naganawa, Shinji; Nakane, Toshiki; Kawai, Hisashi; Taoka, Toshiaki; Suzuki, Kojiro; Iwano, Shingo; Satake, Hiroko; Grodzki, David

2017-04-10

To evaluate the visualization of middle ear ossicles by ultra-short echo time magnetic resonance (MR) imaging at 3T in subjects over 50 years old. Sixty ears from 30 elder patients that underwent surgical or interventional treatment for neurovascular diseases were included (ages: 50-82, median age: 65; 10 men, 20 women). Patients received follow-up MR imaging including routine T 1 - and T 2 -weighted images, time-of-flight MR angiography, and ultra-short echo time imaging (PETRA, pointwise encoding time reduction with radial acquisition). All patients underwent computed tomography (CT) angiography before treatment. Thin-section source CT images were correlated with PETRA images. Scan parameters for PETRA were: TR 3.13, TE 0.07, flip angle 6 degrees, 0.83 × 0.83 × 0.83 mm resolution, 3 min 43 s scan time. Two radiologists retrospectively evaluated the visibility of each ossicular structure as positive or negative using PETRA images. The structures evaluated included the head of the malleus, manubrium of the malleus, body of the incus, long process of the incus, and the stapes. Signal intensity of the ossicles was classified as: between labyrinthine fluid and air, similar to labyrinthine fluid, between labyrinthine fluid and cerebellar parenchyma, or higher than cerebellar parenchyma. In all ears, the body of the incus was visible. The head of the malleus was visualized in 36/60 ears. The manubrium of the malleus and long process of the incus was visualized in 1/60 and 4/60 ears, respectively. The stapes were not visualized in any ear. Signal intensity of the visible structures was between labyrinthine fluid and air in all ears. The body of the incus was consistently visualized with intensity between air and labyrinthine fluid on PETRA images in aged subjects. Poor visualization of the manubrium of the malleus, long process of the incus, and the stapes limits clinical significance of middle ear imaging with current PETRA methods.

Pressure buffering by the tympanic membrane. In vivo measurements of middle ear pressure fluctuations during elevator motion.

PubMed

Padurariu, Simona; de Greef, Daniël; Jacobsen, Henrik; Nlandu Kamavuako, Ernest; Dirckx, Joris J; Gaihede, Michael

2016-10-01

The tympanic membrane (TM) represents a pressure buffer, which contributes to the overall pressure regulation of the middle ear (ME). This buffer capacity is based on its viscoelastic properties combined with those of the attached ossicular chain, muscles and ligaments. The current work presents a set of in vivo recordings of the ME pressure variations normally occurring in common life: elevator motion. This is defined as a situation of smooth ambient pressure increase or decrease on a limited range and at a low rate of pressure change. Based on these recordings, the purpose was a quantitative analysis of the TM buffer capacity including the TM compliance. The pressure changes in seven normal adult ME's with intact TM's were continuously recorded directly inside the ME cavity during four different elevator trips using a high precision instrument. The TM buffer capacity was determined by the ratio between the changes in ME and the ambient pressure. Further, the ME volumes were calculated by Boyle's Law from pressure recordings during inflation-deflation tests; subsequently the TM compliance could also be calculated. Finally, the correlation between the ME volume and buffer function was determined. Twenty-one elevator trips could be used for the analysis. The overall mean TM pressure buffering capacity was 23.3% (SEM = 3.4), whereas the mean overall compliance was 28.9 × 10 -3  μL/Pa (SEM = 4.8). A strong negative linear correlation was found between the TM buffer capacity and the ME volumes (R 2  = 0.92). These results were in fair agreement with the literature obtained in clinical as well as temporal bone experiments, and they provide an in vivo reference for the normal ME function as well as for ME modeling. The TM buffer capacity was found more efficient in smaller mastoids. Possible clinical implications are discussed. Copyright © 2015 Elsevier B.V. All rights reserved.

Cost analysis and outcomes of a second-look tympanoplasty-mastoidectomy strategy for cholesteatoma.

PubMed

Crowson, Matthew G; Ramprasad, Vaibhav H; Chapurin, Nikita; Cunningham, Calhoun D; Kaylie, David M

2016-11-01

To analyze cost and compare cholesteatoma recidivism and hearing outcomes with single-stage and second-look operative strategies. Retrospective review and cost analysis. Adult and pediatric patients who underwent a tympanoplasty with mastoidectomy for cholesteatoma with a single-stage or second-look operative strategy were identified. Variables included procedure approach, residual or recurrent cholesteatoma, ossicular chain reconstruction frequency, and operative complications. Audiologic outcomes included pre-/postoperative air bone gap (ABG) and word recognition score (WRS). Cost analysis included charges for consultation and follow-up visits, surgical procedures, computed tomography temporal bone scans, and audiology visits. One hundred and six patients had a tympanoplasty with mastoidectomy for cholesteatoma, with 80 canal wall-up procedures (CWU) as initial approach. Of these, 46 (57.5%) CWU patients had a planned second look. Two (4.3%) CWU patients had recurrent cholesteatoma and 20 (43.4%) had residual identified at second look. Four (11.7%) single-stage CWU strategy patients developed recurrent cholesteatoma. There was no significant difference in pre-/postoperative ABG and WRS between second look and single stage (P > 0.05). Compared to second-look patients, single-stage patients had significantly fewer postoperative visits (6.32 vs. 10.4; P = 0.007), and significantly lower overall charges for care ($23,529. vs. $41.411; P < 0.0001). The goal of cholesteatoma surgery is to produce a safe ear, and a second-look strategy after CWU has historically been used to evaluate for recurrent or residual disease. The cholesteatoma recurrence rate at a second look after a CWU tympanoplasty-mastoidectomy is low. Costs of operative procedures are a significant proportion of healthcare resource expenditures. Considering the low rate of cholesteatoma recurrence and relatively high cost of care, implementation of a second-look strategy should be individually tailored and not universally performed. 4. Laryngoscope, 126:2574-2579, 2016. © 2016 The American Laryngological, Rhinological and Otological Society, Inc.

Acoustic input and efferent activity regulate the expression of molecules involved in cochlear micromechanics

PubMed Central

Lamas, Veronica; Arévalo, Juan C.; Juiz, José M.; Merchán, Miguel A.

2015-01-01

Electromotile activity in auditory outer hair cells (OHCs) is essential for sound amplification. It relies on the highly specialized membrane motor protein prestin, and its interactions with the cytoskeleton. It is believed that the expression of prestin and related molecules involved in OHC electromotility may be dynamically regulated by signals from the acoustic environment. However little is known about the nature of such signals and how they affect the expression of molecules involved in electromotility in OHCs. We show evidence that prestin oligomerization is regulated, both at short and relatively long term, by acoustic input and descending efferent activity originating in the cortex, likely acting in concert. Unilateral removal of the middle ear ossicular chain reduces levels of trimeric prestin, particularly in the cochlea from the side of the lesion, whereas monomeric and dimeric forms are maintained or even increased in particular in the contralateral side, as shown in Western blots. Unilateral removal of the auditory cortex (AC), which likely causes an imbalance in descending efferent activity on the cochlea, also reduces levels of trimeric and tetrameric forms of prestin in the side ipsilateral to the lesion, whereas in the contralateral side prestin remains unaffected, or even increased in the case of trimeric and tetrameric forms. As far as efferent inputs are concerned, unilateral ablation of the AC up-regulates the expression of α10 nicotinic Ach receptor (nAChR) transcripts in the cochlea, as shown by RT-Quantitative real-time PCR (qPCR). This suggests that homeostatic synaptic scaling mechanisms may be involved in dynamically regulating OHC electromotility by medial olivocochlear efferents. Limited, unbalanced efferent activity after unilateral AC removal, also affects prestin and β-actin mRNA levels. These findings support that the concerted action of acoustic and efferent inputs to the cochlea is needed to regulate the expression of major molecules involved in OHC electromotility, both at the transcriptional and posttranscriptional levels. PMID:25653600

Implementing Replacement Cost Accounting

DTIC Science & Technology

1976-12-01

cost accounting Clickener, John Ross Monterey, California. Naval Postgraduate School http://hdl.handle.net/10945/17810 Downloaded from NPS Archive...Calhoun IMPLEMENTING REPLACEMENT COST ACCOUNTING John Ross CHckener NAVAL POSTGRADUATE SCHOOL Monterey, California THESIS IMPLEMENTING REPLACEMENT COST ...Implementing Replacement Cost Accounting 7. AUTHORS John Ross Clickener READ INSTRUCTIONS BEFORE COMPLETING FORM 3. RECIPIENT’S CATALOG NUMBER 9. TYRE OF

Changing spatial patterns of stand-replacing fire in California conifer forests

Treesearch

Jens T. Stevens; Brandon M. Collins; Jay D. Miller; Malcolm P. North; Scott L. Stephens

2017-01-01

Stand-replacing fire has profound ecological impacts in conifer forests, yet there is continued uncertainty over how best to describe the scale of stand-replacing effects within individual fires, and how these effects are changing over time. In forests where regeneration following stand-replacing fire depends on seed dispersal from surviving trees, the size and shape...

Digital Classrooms: A Multiple Case Study of Four Visually Impaired College Students' Challenges and Opportunities

ERIC Educational Resources Information Center

Malone, Jo Ann

2017-01-01

Access to the Internet and technology skills are essential to the success of college students. Electronic textbooks are replacing paper textbooks. Laptops are replacing pens, pencils, and paper. Electronic forms found on school websites are replacing long registration lines. Hyperlinks are replacing handouts, and face-to-face interaction with…

Processing the Army’s Wartime Replacements: The Preferred CONUS Replacement Center Concept.

DTIC Science & Technology

1987-12-01

Replacement System. The first model, the macro model, was a network flow model which was used to analyze the flow of replacements from their source through...individual CRCs. Through the analysis of the macro model, recommendations were made on how the CRC system should be configured in terms of size, location

75 FR 8386 - Agency Information Collection Activities: Proposed Collection; Comment Request, 1660-0100...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-02-24

...), General Admissions Application Short-Form; 106-0-1 (replaces FEMA Form 75-3), Student Stipend Agreement... collection; OMB No. 1660-0100; FEMA Forms 064-0-1 (replaces FEMA Form 75-5), General Admissions Application; 064-0-2 (replaces FEMA Form 75-5a), General Admissions Application Short-Form; 106-0-1 (replaces FEMA...

75 FR 5511 - Safety Zone; AICW Closure Safety Zone for Ben Sawyer Bridge Replacement Project, Sullivan's...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-02-03

...-AA00 Safety Zone; AICW Closure Safety Zone for Ben Sawyer Bridge Replacement Project, Sullivan's Island... replacement of the old and new approach spans of the Ben Sawyer Swing Bridge. This regulation is necessary to... proposed rulemaking (NPRM) with respect to this rule because hazards associated with the bridge replacement...

Root replacement using stentless valves in the small aortic root: a propensity score analysis.

PubMed

Kunihara, Takashi; Schmidt, Kathrin; Glombitza, Petra; Dzindzibadze, Vachtang; Lausberg, Henning; Schäfers, Hans-Joachim

2006-10-01

Root replacement using a stentless bioprosthesis may be the optimal approach to avoid patient-prosthesis mismatch in patients with a small aortic root. Primary root replacement, however, is considered to be associated with increased surgical risk. We compared early outcome of full root replacement with a stentless bioprosthesis with that of aortic valve replacement with a stented bioprosthesis using propensity score-matching analysis. Of 231 patients undergoing elective, first-time aortic valve replacement with a small root (< or = 22 mm), 120 patients were selected using propensity score-matching analysis. They underwent either root replacement using a 23-mm stentless bioprosthesis (stentless group, n = 60) or supra-annular aortic valve replacement using a 21-mm stented bioprosthesis (stented group, n = 60). Preoperative characteristics and frequency of concomitant operations were identical. Duration of operation (196 +/- 54 versus 174 +/- 49 minutes), cardiopulmonary bypass (112 +/- 36 versus 91 +/- 33 minutes), and aortic cross-clamping (76 +/- 21 versus 61 +/- 21 minutes) were significantly longer in the stentless group. However, the need for perioperative transfusion and the incidence of postoperative reexploration for bleeding (3% versus 8%) was lower, and ventilation time was shorter. Mean duration of intensive care and hospital stay were also significantly shorter (2.3 +/- 1.7 versus 4.0 +/- 3.9 days, 8.9 +/- 3.1 versus 12.4 +/- 5.7 days). In-hospital mortality was identical (5% each). No independent predictor for in-hospital mortality was identified. Full root replacement using a stentless bioprosthesis does not increase postoperative morbidity or mortality of aortic valve replacement and may be advantageous in patients with a small aortic root.

Estimating the Risks and Benefits of Implantable Cardioverter Defibrillator Generator Replacement: A Systematic Review.

PubMed

Lewis, Krystina B; Stacey, Dawn; Carroll, Sandra L; Boland, Laura; Sikora, Lindsey; Birnie, David

2016-07-01

Every 4-7 years an implantable cardioverter defibrillator (ICD) pulse generator must be replaced surgically. This procedure is not without risk. In some cases, the risk versus benefit ratio may be against replacement. We aimed to synthesize the evidence on risks, benefits, and costs related to ICD replacement. A systematic review was conducted using electronic databases from 2000 onward. Literature screening, quality appraisal, and data extraction were independently conducted by two reviewers. Outcomes included major and minor complications, ICD therapies, and costs, which were synthesized descriptively. Of 1,483 citations, 17 nonrandomized studies met criteria. Median rate of major complications was 4.05% (range 0.55-7.37%) and minor complications was 3.50% (range 0.36-7.37%). Without non-ICD control groups, the true risk reduction provided by the ICD following replacement is unknown. Following ICD replacement, annualized rate of appropriate ICD therapy was 10.52% (range 2.42-75.00%). Of these, patients without therapies during their first generator life and those no longer meeting ICD criteria received appropriate therapies at nontrivial rates. Rates of complications associated with ICD replacement are substantial. No study had nonreplacement groups, hence the true risk reduction provided by the ICD following replacement is unknown. Our analysis did not identify a subgroup at low risk of therapies following replacement. Shared discussions should occur with patients about the evidence, healthcare goals, risk tolerances, and feelings about life and death trade-offs to enable high-quality decisions about ICD replacement. ©2016 Wiley Periodicals, Inc.

Comparison of the nutrient composition of commercial dog milk replacers with that of dog milk

PubMed Central

Heinze, Cailin R.; Freeman, Lisa M.; Martin, Camilia R.; Power, Michael L.; Fascetti, Andrea J.

2015-01-01

Objective To compare the nutrient composition of commercially available dog milk replacers with that of dog milk. Design Prospective, cross-sectional study. Sample 5 dog milk samples and 15 samples of commercial dog milk replacers. Procedures Dog milk and milk replacers were analyzed for concentrations of total protein, essential amino acids, sugars, total fat, essential fatty acids, calcium, and phosphorus. Energy density was calculated. Results from milk replacers were compared with the range of the concentration of each nutrient in milk samples from mature dogs as well as the National Research Council (NRC) recommendations for puppy growth. Results Milk replacers varied widely in caloric density and concentration of nutrients such as calcium, protein, and fat. Calcium concentration was lower in 14 of 15 milk replacers than in the dog milk samples. Docosahexaenoic acid was undetectable in 12 of 15 milk replacers but present in all dog milk samples. All milk replacers had numerous essential nutrients outside of the range of the dog milk samples, and many had concentrations of amino acids, essential fatty acids, calcium, and phosphorus less than the NRC minimal requirement or recommended allowance. Compared with NRC recommendations, some dog milk samples had concentrations of total protein, linoleic acid, calcium, or phosphorus less than the recommended allowance. Conclusions and Clinical Relevance Results suggested that there was substantial variation in nutrient composition of 15 dog milk replacers and that some products were closer approximations of dog milk than others. Nearly all products would benefit from more appropriate calcium, amino acids, and essential fatty acids concentrations and better feeding directions. PMID:24871064

Circadian variation in serum cortisol during hydrocortisone replacement is not attributable to changes in cortisol-binding globulin concentrations.

PubMed

Chung, T T; Gunganah, K; Monson, J P; Drake, W M

2016-04-01

Patients taking hydrocortisone (HC) replacement for primary or secondary adrenal failure require individual adjustment of their dose. In addition to modifying the administered doses of HC for each patient, physicians are increasingly interested in variations in the bioavailability of glucocorticoid replacement. One potential determinant of the bioavailability of replaced HC is a variation in serum cortisol-binding globulin (CBG) concentration, which may, in turn, affect interpretation of cortisol profiles and individual dose selection for patients on hydrocortisone replacement therapy. To investigate the hypothesis that there is a circadian variation in CBG levels. A total of 34 male patients divided into 3 groups (10 patients with non-somatotroph structural pituitary disease on HC replacement, 11 patients with treated acromegaly on HC replacement and 13 patients with treated acromegaly not on HC replacement) and 10 healthy volunteers were included. Cortisol and CBG levels were measured at 6 time points (0800, 1100, 1300, 1500, 1700 and 1900). No significant circadian variation in CBG concentration was found in any of the 4 groups. Circadian variation in serum cortisol during hydrocortisone replacement is not attributable to changes in cortisol-binding globulin concentration. Changes in serum cortisol levels may thus be explained by other factors including 11 β-hydroxysteroid dehydrogenase type 1 activity or circadian changes in the binding properties of CBG. © 2015 John Wiley & Sons Ltd.

Energy Efficiency Upgrades

DOE Office of Scientific and Technical Information (OSTI.GOV)

Roby Williams

2012-03-29

The energy efficiency upgrades project at Hardin County General Hospital did not include research nor was it a demonstration project. The project enabled the hospital to replace outdated systems with modern efficient models. Hardin County General Hospital is a 501c3, nonprofit hospital and the sole community provider for Hardin and Pope Counties of Illinois. This project provided much needed equipment and facility upgrades that would not have been possible through locally generated funding. Task 1 was a reroofing of the hospital. The hospital architect designed the replacement to increase the energy efficiency of the hospital roof/ceiling structure. Task 2 wasmore » replacement and installation of a new more efficient CT scanner for the hospital. Included in the project was replacement of HVAC equipment for the entire radiological suite. Task 5 was a replacement and installation of a new higher capacity diesel-fueled emergency generator for the hospital replacing a 50+ year old gas-fired generator. Task 7 was the replacement of 50+ year-old walk-in cooler/freezer with a newer, energy efficient model. Task 8 was the replacement of 10+ year-old washing machines in the hospital laundry with higher capacity, energy efficient models. Task 9 was replacement of 50-year old single pane curtain window system with double-pane insulated windows. Additionally, insulation was added around ventilation systems and the curtain wall system.« less

77 FR 59852 - Fisheries of the Exclusive Economic Zone Off Alaska; Bering Sea and Aleutian Islands Management...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-10-01

...NMFS publishes regulations to implement Amendment 97 to the Fishery Management Plan for Groundfish of the Bering Sea and Aleutian Islands Management Area (FMP). Amendment 97 allows the owner of a trawl catcher/processor vessel authorized to participate in the Amendment 80 catch share program to replace that vessel with a vessel that meets certain requirements. This action establishes the regulatory process for replacement of vessels in the Amendment 80 fleet and the requirements for Amendment 80 replacement vessels, such as a limit on the overall length of a replacement vessel, a prohibition on the use of an AFA vessel as a replacement vessel, measures to prevent a replaced vessel from participating in Federal groundfish fisheries off Alaska that are not Amendment 80 fisheries, and measures that extend specific catch limits (known as Amendment 80 sideboards) to a replacement vessel. This action is necessary to promote safety-at-sea by allowing Amendment 80 vessel owners to replace their vessels for any reason at any time and by requiring replacement vessels to meet certain U.S. Coast Guard vessel safety standards, and to improve the retention and utilization of groundfish catch by these vessels by facilitating an increase in the processing capabilities of the fleet. This action is intended to promote the goals and objectives of the Magnuson-Stevens Fishery Conservation and Management Act, the FMP, and other applicable laws.

How do gait frequency and serum-replacement interval affect polyethylene wear in knee-wear simulator tests?

PubMed

Reinders, Jörn; Sonntag, Robert; Kretzer, Jan Philippe

2014-11-01

Polyethylene wear (PE) is known to be a limiting factor in total joint replacements. However, a standardized wear test (e.g. ISO standard) can only replicate the complex in vivo loading condition in a simplified form. In this study, two different parameters were analyzed: (a) Bovine serum, as a substitute for synovial fluid, is typically replaced every 500,000 cycles. However, a continuous regeneration takes place in vivo. How does serum-replacement interval affect the wear rate of total knee replacements? (b) Patients with an artificial joint show reduced gait frequencies compared to standardized testing. What is the influence of a reduced frequency? Three knee wear tests were run: (a) reference test (ISO), (b) testing with a shortened lubricant replacement interval, (c) testing with reduced frequency. The wear behavior was determined based on gravimetric measurements and wear particle analysis. The results showed that the reduced test frequency only had a small effect on wear behavior. Testing with 1 Hz frequency is therefore a valid method for wear testing. However, testing with a shortened replacement interval nearly doubled the wear rate. Wear particle analysis revealed only small differences in wear particle size between the different tests. Wear particles were not linearly released within one replacement interval. The ISO standard should be revised to address the marked effects of lubricant replacement interval on wear rate.

Influence of fat replacers on chemical composition, proteolysis, texture profiles, meltability and sensory properties of low-fat Kashar cheese.

PubMed

Sahan, Nuray; Yasar, Kurban; Hayaloglu, Ali A; Karaca, Oya B; Kaya, Ahmet

2008-02-01

Changes in chemical composition, proteolysis, lipolysis, texture, melting and sensory properties of low-fat Kashar cheese made with three different fat replacers (Simplesse D-100, Avicel Plus CM 2159 or beta-glucan) were investigated throughout ripening. The low-fat cheeses made with fat replacers were compared with full- and low-fat counterparts as controls. Reduction of fat caused increases in moisture and protein contents and decreases in moisture-in-non fat substance and yield values in low-fat cheeses. The use of fat replacers in the manufacture of low-fat Kashar cheese increased water binding capacity and improved overall quality of the cheeses. Use of fat replacer in low-fat cheese making has enhanced cheese proteolysis. All samples underwent lipolysis during ripening and low-fat cheeses with fat replacers had higher level of total free fatty acid than full- or low-fat control cheeses. Texture attributes and meltability significantly increased with addition of fat replacers. Sensory scores showed that the full-fat cheese was awarded best in all stages of ripening and low-fat variant of Kashar cheeses have inferior quality. However, fat replacers except beta-glucan improved the appearance, texture and flavour attributes of low-fat cheeses. When the fat replacers are compared, the low-fat cheese with Avicel Plus CM 2159 was highly acceptable and had sensory attributes closest to full-fat Kashar cheese.

Properties of Cement Mortar Produced from Mixed Waste Materials with Pozzolanic Characteristics.

PubMed

Yen, Chi-Liang; Tseng, Dyi-Hwa; Wu, Yue-Ze

2012-07-01

Waste materials with pozzolanic characteristics, such as sewage sludge ash (SSA), coal combustion fly ash (FA), and granulated blast furnace slag (GBS), were reused as partial cement replacements for making cement mortar in this study. Experimental results revealed that with dual replacement of cement by SSA and GBS and triple replacement by SSA, FA, and GBS at 50% of total cement replacement, the compressive strength (Sc) of the blended cement mortars at 56 days was 93.7% and 92.9% of the control cement mortar, respectively. GBS had the highest strength activity index value and could produce large amounts of CaO to enhance the pozzolanic activity of SSA/FA and form calcium silicate hydrate gels to fill the capillary pores of the cement mortar. Consequently, the Sc development of cement mortar with GBS replacement was better than that without GBS, and the total pore volume of blended cement mortars with GBS/SSA replacement was less than that with FA/SSA replacement. In the cement mortar with modified SSA and GBS at 70% of total cement replacement, the Sc at 56 days was 92.4% of the control mortar. Modifying the content of calcium in SSA also increased its pozzolanic reaction. CaCl(2) accelerated the pozzolanic activity of SSA better than lime did. Moreover, blending cement mortars with GBS/SSA replacement could generate more monosulfoaluminate to fill capillary pores.

Properties of Cement Mortar Produced from Mixed Waste Materials with Pozzolanic Characteristics

PubMed Central

Yen, Chi-Liang; Tseng, Dyi-Hwa; Wu, Yue-Ze

2012-01-01

Abstract Waste materials with pozzolanic characteristics, such as sewage sludge ash (SSA), coal combustion fly ash (FA), and granulated blast furnace slag (GBS), were reused as partial cement replacements for making cement mortar in this study. Experimental results revealed that with dual replacement of cement by SSA and GBS and triple replacement by SSA, FA, and GBS at 50% of total cement replacement, the compressive strength (Sc) of the blended cement mortars at 56 days was 93.7% and 92.9% of the control cement mortar, respectively. GBS had the highest strength activity index value and could produce large amounts of CaO to enhance the pozzolanic activity of SSA/FA and form calcium silicate hydrate gels to fill the capillary pores of the cement mortar. Consequently, the Sc development of cement mortar with GBS replacement was better than that without GBS, and the total pore volume of blended cement mortars with GBS/SSA replacement was less than that with FA/SSA replacement. In the cement mortar with modified SSA and GBS at 70% of total cement replacement, the Sc at 56 days was 92.4% of the control mortar. Modifying the content of calcium in SSA also increased its pozzolanic reaction. CaCl2 accelerated the pozzolanic activity of SSA better than lime did. Moreover, blending cement mortars with GBS/SSA replacement could generate more monosulfoaluminate to fill capillary pores. PMID:22783062

Early forest dynamics in stand-replacing fire patches in the northern Sierra Nevada, California, USA

Treesearch

Brandon M. Collins; Gary B. Roller

2013-01-01

There is considerable concern over the occurrence of stand-replacing fire in forest types historically associated with low- to moderate-severity fire. The concern is largely over whether contemporary levels of stand-replacing fire are outside the historical range of variability, and what natural forest recovery is in these forest types following stand-replacing fire....

75 FR 24722 - Agency Information Collection Activities: Submission for OMB Review; Comment Request, OMB No...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-05-05

... information collection; OMB No. 1660-0100; FEMA Forms 119-25-1 (replaces FEMA Form 75-5), General Admissions Application; 119-25-2 (replaces FEMA Form 75-5a), General Admissions Application Short-Form; 119-25-3 (replaces FEMA Form 75-3), Student Stipend Agreement; and 119-25-4 (replaces FEMA For 75-3a), Student...

Effect on smoking cessation of switching nicotine replacement therapy to over-the-counter status.

PubMed

Thorndike, Anne N; Biener, Lois; Rigotti, Nancy A

2002-03-01

This study examined whether the change in nicotine replacement therapy sales from prescription to over the counter (OTC) status affected smoking cessation. We used the 1993-1999 Massachusetts Tobacco Surveys to compare data from adult current smokers and recent quitters before and after the OTC switch. No significant change over time occurred in the proportion of smokers who used nicotine replacement therapy at a quit attempt in the past year (20.1% pre-OTC vs 21.4% post-OTC), made a quit attempt in the past year (48.1% vs 45.2%), or quit smoking in the past year (8.1% vs 11.1%). Fewer non-Whites used nicotine replacement therapy after the switch (20.7% pre-OTC vs 3.2% post-OTC, P =.002), but the proportion of Whites using nicotine replacement therapy did not change significantly (20.6% vs 24.0%). We observed no increase in Massachusetts smokers' rates of using nicotine replacement therapy, making a quit attempt, or stopping smoking after nicotine replacement therapy became available for OTC sale. There appear to be other barriers to the use of nicotine replacement therapy besides visiting a physician, especially among minority smokers.

Supercapacitor performance evaluation in replacing battery based on charging and discharging current characteristics

NASA Astrophysics Data System (ADS)

Sani, A.; Siahaan, S.; Mubarakah, N.; Suherman

2018-02-01

Supercapacitor is a new device of energy storage, which has much difference between ordinary capacitors and batteries. Supercapacitor have higher capacitance and energy density than regular capacitors. The supercapacitor also has a fast charging time, as well as a long life. To be used as a battery replacement please note the internal parameters of the battery to be replaced. In this paper conducted a simulation study to utilize supercapacitor as a replacement battery. The internal parameters of the battery and the supercapacitor are obtained based on the characteristics of charging and discharging current using a predefined equivalent circuit model. The battery to be replaced is a 12-volt lead-acid type, 6.5 Ah which is used on motorcycles with 6A charging and discharging currents. Super capacitor replacement capacitor is a capacity of 1600F, 2.7V which is connected in series as many as 6 pieces with 16.2 volt terminal voltage and charging current 12A. To obtain the same supercapacitor characteristic as the battery characteristic to be replaced, modification of its internal parameters is made. The results show that the super-capacitor can replace the battery function for 1000 seconds.

Variant surface glycoprotein density defines an immune evasion threshold for African trypanosomes undergoing antigenic variation.

PubMed

Pinger, Jason; Chowdhury, Shanin; Papavasiliou, F Nina

2017-10-10

Trypanosoma brucei is a protozoan parasite that evades its host's adaptive immune response by repeatedly replacing its dense variant surface glycoprotein (VSG) coat from its large genomic VSG repertoire. While the mechanisms regulating VSG gene expression and diversification have been examined extensively, the dynamics of VSG coat replacement at the protein level, and the impact of this process on successful immune evasion, remain unclear. Here we evaluate the rate of VSG replacement at the trypanosome surface following a genetic VSG switch, and show that full coat replacement requires several days to complete. Using in vivo infection assays, we demonstrate that parasites undergoing coat replacement are only vulnerable to clearance via early IgM antibodies for a limited time. Finally, we show that IgM loses its ability to mediate trypanosome clearance at unexpectedly early stages of coat replacement based on a critical density threshold of its cognate VSGs on the parasite surface. Trypanosoma brucei evades the host immune system through replacement of a variant surface glycoprotein (VSG) coat. Here, the authors show that VSG replacement takes several days to complete, and the parasite is vulnerable to the host immune system for a short period of time during the process.

Management of the failed biaxial wrist replacement.

PubMed

Talwalkar, S C; Hayton, M J; Trail, I A; Stanley, J K

2005-06-01

Nine cases of failed biaxial wrist replacement underwent revision surgery and subsequent clinical and radiographic assessment at a mean follow-up of 28 months. Clinical assessment included the hospital for special surgery (HSS) and activities of daily living scoring systems. Five patients had a revision biaxial wrist replacement, three had wrist fusions and two underwent an excision arthroplasty. The mean HSS score was 73 for the revision biaxial replacements, 63 for the wrist fusions and 92 for the excision arthroplasties. The mean activities for daily living score was 16 for the revision biaxial replacements, 14 for the wrist fusion and 20 for the excision arthroplasties. Despite the experience of implant failure, six patients would still choose a primary wrist replacement again. All patients in this small series appear to have had good clinical outcomes. Revision to another wrist replacement appears no worse than a wrist fusion in the short term and patients value the preservation of movement that an implant offers.

Aortic valve replacement for stenosis with or without coronary artery bypass grafting after 2 previous isolated coronary artery bypass grafting operations

PubMed Central

Lee Henry, Christopher; Ko, Jong Mi; Henry, Albert Carl; Matter, Gregory John

2011-01-01

Aortic valve replacement following an earlier coronary artery bypass grafting (CABG) procedure is fairly common. When this situation occurs, the type of valve dysfunction is usually stenosis (with or without regurgitation), and whether it was missed at the time of the earlier CABG or developed subsequently is usually unclear. We attempted to determine the survival in patients who had had aortic valve replacement after 2 previous CABG procedures. We describe 12 patients who had aortic valve replacement for aortic stenosis; rather than one previous CABG operation, all had had 2 previous CABG procedures. Only one patient died in the early postoperative period after aortic valve replacement, and the remaining 11 were improved substantially: all have lived at least 11 months, and one is still alive at over 101 months after aortic valve replacement. Aortic valve replacement remains beneficial for most patients even after 2 previous CABG procedures. PMID:21307968

Survey of patient-oriented total hip replacement information on the World Wide Web.

PubMed

Mabrey, J D

2000-12-01

The author conducted an informal survey of materials relating to diseases of the hip and total hip replacement as they appeared on the World Wide Web. The results varied depending on the key words used: hip and replacement yielded 1,818 matches; total hip replacement yielded 1,740 matches; hip replacement yielded 4,565 sites; and hip surgery yielded 1,073 sites. The number of sites for total hip replacement was observed to increase with time, having found an additional 30 sites from an identical search performed only 6 weeks earlier. The nature and quality of these sites varied from well-organized and informative, to personal testaments, to obvious commercial endeavors. Overall, this survey found an abundance of material regarding the hip and hip replacements on the World Wide Web, but orthopaedic societies need to take a more active role in constructing, maintaining, and monitoring these sites to best serve the needs of their patients and their members.

An Investment Level Decision Method to Secure Long-term Reliability

NASA Astrophysics Data System (ADS)

Bamba, Satoshi; Yabe, Kuniaki; Seki, Tomomichi; Shibaya, Tetsuji

The slowdown in power demand increase and facility replacement causes the aging and lower reliability in power facility. And the aging is followed by the rapid increase of repair and replacement when many facilities reach their lifetime in future. This paper describes a method to estimate the repair and replacement costs in future by applying the life-cycle cost model and renewal theory to the historical data. This paper also describes a method to decide the optimum investment plan, which replaces facilities in the order of cost-effectiveness by setting replacement priority formula, and the minimum investment level to keep the reliability. Estimation examples applied to substation facilities show that the reasonable and leveled future cash-out can keep the reliability by lowering the percentage of replacements caused by fatal failures.

Risks and benefits of citrate anticoagulation for continuous renal replacement therapy.

PubMed

Shum, H P; Yan, W W; Chan, T M

2015-04-01

Heparin, despite its significant side-effects, is the most commonly used anticoagulant for continuous renal replacement therapy in critical care setting. In recent years, citrate has gained much popularity by improving continuous renal replacement therapy circuit survival and decreasing blood transfusion requirements. However, its complex metabolic consequences warrant modification in the design of the citrate-based continuous renal replacement therapy protocol. With thorough understanding of the therapeutic mechanism of citrate, a simple and practicable protocol can be devised. Citrate-based continuous renal replacement therapy can be safely and widely used in the clinical setting with appropriate clinical staff training.

Mitochondrial replacement techniques: egg donation, genealogy and eugenics.

PubMed

Palacios-González, César

2016-03-01

Several objections against the morality of researching or employing mitochondrial replacement techniques have been advanced recently. In this paper, I examine three of these objections and show that they are found wanting. First I examine whether mitochondrial replacement techniques, research and clinical practice, should not be carried out because of possible harms to egg donors. Next I assess whether mitochondrial replacement techniques should be banned because they could affect the study of genealogical ancestry. Finally, I examine the claim that mitochondrial replacement techniques are not transferring mitochondrial DNA but nuclear DNA, and that this should be prohibited on ethical grounds.

Knee and Ankle Arthroplasty in Hemophilia

PubMed Central

Solimeno, Luigi Piero; Pasta, Gianluigi

2017-01-01

Today, major surgical procedures can be safely performed in hemophilic patients with chronic arthropathy, using available factor concentrates. In this setting, total knee replacement is considered the “gold standard”, while the use of total ankle replacement is still debated. Indeed, the unsatisfactory results obtained with the previous available design of implants did not raise enthusiasm as knee or hip replacement. Recently, the introduction of new implant designs and better reported outcomes have renewed the interest in total ankle replacement in people with hemophilia. In this review, the role of replacement surgery in the treatment of chronic hemophilic arthropathy will be described. PMID:29165342

Hip Replacement Surgery

MedlinePlus

... Download Download EPUB Download PDF What is it? Points To Remember About Hip Replacement Surgery Hip replacement ... This leaves your hands and arms free for balance or to use crutches. Use a long-handled " ...

25 CFR 700.53 - Dwelling, replacement.

Code of Federal Regulations, 2010 CFR

2010-04-01

... Policies and Instructions Definitions § 700.53 Dwelling, replacement. The term replacement dwelling means a... unreasonable adverse environmental conditions from either natural or man-made sources and in an area not...

Mortality rates at 10 years after metal-on-metal hip resurfacing compared with total hip replacement in England: retrospective cohort analysis of hospital episode statistics

PubMed Central

Kendal, Adrian R; Prieto-Alhambra, Daniel; Arden, Nigel K; Judge, Andrew

2013-01-01

Objectives To compare 10 year mortality rates among patients undergoing metal-on-metal hip resurfacing and total hip replacement in England. Design Retrospective cohort study. Setting English hospital episode statistics database linked to mortality records from the Office for National Statistics. Population All adults who underwent primary elective hip replacement for osteoarthritis from April 1999 to March 2012. The exposure of interest was prosthesis type: cemented total hip replacement, uncemented total hip replacement, and metal-on-metal hip resurfacing. Confounding variables included age, sex, Charlson comorbidity index, rurality, area deprivation, surgical volume, and year of operation. Main outcome measures All cause mortality. Propensity score matching was used to minimise confounding by indication. Kaplan-Meier plots estimated the probability of survival up to 10 years after surgery. Multilevel Cox regression modelling, stratified on matched sets, described the association between prosthesis type and time to death, accounting for variation across hospital trusts. Results 7437 patients undergoing metal-on-metal hip resurfacing were matched to 22 311 undergoing cemented total hip replacement; 8101 patients undergoing metal-on-metal hip resurfacing were matched to 24 303 undergoing uncemented total hip replacement. 10 year rates of cumulative mortality were 271 (3.6%) for metal-on-metal hip resurfacing versus 1363 (6.1%) for cemented total hip replacement, and 239 (3.0%) for metal-on-metal hip resurfacing versus 999 (4.1%) for uncemented total hip replacement. Patients undergoing metal-on-metal hip resurfacing had an increased survival probability (hazard ratio 0.51 (95% confidence interval 0.45 to 0.59) for cemented hip replacement; 0.55 (0.47 to 0.65) for uncemented hip replacement). There was no evidence for an interaction with age or sex. Conclusions Patients with hip osteoarthritis undergoing metal-on-metal hip resurfacing have reduced mortality in the long term compared with those undergoing cemented or uncemented total hip replacement. This difference persisted after extensive adjustment for confounding factors available in our data. The study results can be applied to matched populations, which exclude patients who are very old and have had complex total hip replacements. Although residual confounding is possible, the observed effect size is large. These findings require validation in external cohorts and randomised clinical trials. PMID:24284336

Pacemaker

MedlinePlus

... check for changes in your heart's electrical activity. Battery Replacement Pacemaker batteries last between 5 and 15 years (average 6 ... doctor will replace the generator along with the battery before the battery starts to run down. Replacing ...

Consequences of wear interruption for discomfort with contact lenses.

PubMed

Papas, Eric B; Tilia, Daniel; Tomlinson, Daniel; Williams, Josh; Chan, Eddy; Chan, Jason; Golebiowski, Blanka

2014-01-01

To establish whether increased end-of-day discomfort during soft contact lens wear is associated with short-term changes occurring to the lens itself. Twenty-seven subjects wore hydrogel lenses (Focus Dailies; Alcon) bilaterally for 10 hours on two separate days. Comfort was reported using 1-100 numerical rating scales (1 = intolerable discomfort, 100 = lens cannot be felt). Day 1 ratings were taken before lens insertion and at 0.05, 5, and 10 hours post-insertion. Day 2 ratings occurred at similar times, but lenses were removed after the 5-hour assessment and either reinserted (n = 14) or newly replaced (n = 12). An additional rating was taken 5 minutes after re-insertion. Wear then continued to the 10-hour point. In a separate study, 24 different subjects repeated these procedures using a silicone hydrogel lens (AirOptix Aqua; Alcon) with wear taking place on 3 days to permit lens replacement to be with existing as well as new lenses in all subjects. For hydrogel lenses, comfort scores (mean ± 95% CI) reported after 10 hours were 79.4 ± 8.3 when lenses were worn un-replaced, compared with 73.2 ± 9.2 for replacement with the existing lens. When replacement was with a brand new lens, the corresponding values were 72.9 ± 10.9 (un-replaced) versus 69.2 ± 12.8 (new lens replacement). For silicone hydrogel lenses, 10-hour comfort was 90.3 ± 3.2 (un-replaced) versus 92.2 ± 2.9 (replacement with existing lens) versus 90.0 ± 3.3 (replacement with new lens). Differences between replacement conditions were not significant in any case (analysis of variance, p > 0.05). Final comfort was not influenced by replacing lenses midway through the wearing period. Comfort decrements experienced by users of these daily contact lenses towards the later part of the wearing period are not caused by changes occurring to the lenses on this time scale. Possible alternative etiological factors include a fatigue-like response in one or more ocular tissues or stimulation of ocular surface nociceptors induced by the presence of the contact lens.

Healthcare Utilization and Costs of Knee or Hip Replacements versus Pain-Relief Injections

PubMed Central

Pasquale, Margaret K.; Louder, Anthony M.; Cheung, Raymond Y.; Reiners, Andrew T.; Mardekian, Jack; Sanchez, Robert J.; Goli, Veerainder

2015-01-01

Background Given the dramatic increase in total knee and hip replacement procedures among the US population aged 45 years and older, there is a need to compare the downstream healthcare utilization and costs between patients who undergo joint replacement and those who receive intraarticular injections as a low-cost alternative. Objective To compare changes in osteoarthritis (OA)-related healthcare utilization and costs for Medicare members with OA who underwent knee or hip replacement versus those receiving steroid or viscosupplementation injections. Methods Medicare members aged ≥45 years diagnosed with OA were identified for this retrospective longitudinal study. Data were compared for patients who underwent primary knee or hip replacement surgery between July 1, 2007, and June 30, 2012, and those receiving injection of pain-relief medication during the same period. The date of joint replacement surgery was considered the index date. For the comparison cohort, the index date was 180 days postinjection of the first intraarticular injection. Medical and pharmacy claims were examined longitudinally in 90-day increments, from 180 days preindex until 360 days postindex. Difference-in-difference analyses were conducted to compare the change in OA-related healthcare costs, postindex versus preindex, between the study cohorts. Time-to-event analyses were used to measure rates of readmissions and venous thromboembolism (VTE). Results The mean age was 70.7 years for patients with knee replacement, 71.7 years for those with hip replacement, and 71.1 years for those receiving pain-relief injection (P <.0001). The RxRisk-V comorbidity index scores were 4.7, 4.4, and 4.8, respectively (P <.0001). Difference-in-difference analyses indicated that decreases in OA-related costs were greater for the joint replacement cohorts (coefficient for knee replacement*time: −0.603; hip replacement*time: −0.438; P <.001 for both) than for the comparison cohort. The VTE rates were 5.6% (knee) and 5.1% (hip) postsurgery versus 1.4% (knee) and 1.3% (hip) presurgery. Conclusion The overall difference-in-difference results showed a greater decrease in healthcare utilization and costs for the members with joint replacement than for those receiving injection. PMID:26557232

CardiaMed mechanical valve: mid-term results of a multicenter clinical trial.

PubMed

Nazarov, Vladimir M; Zheleznev, Sergey I; Bogachev-Prokophiev, Alexandr V; Afanasyev, Alexandr V; Nemchenko, Eugene V; Jeltovskiy, Yuri V; Lavinyukov, Sergey O

2014-01-01

Prosthesis choice is a major concern in valvular surgery. A multicenter clinical trial was performed to assess the efficacy and safety of the CardiaMed prosthetic heart valve. The study enrolled 420 patients who underwent mitral (209) or aortic (211) valve replacement from 2003 to 2004 at 7 institutions in Russia, and who were followed up from 2006 to 2011. The mean age was 52.2 ± 10.2 years (range, 12-78 years), 47.4% were female, and 99.05% completed the study. The maximum observation term was 7.5 years (2188.5 patient-years); 1081.6 patient-years for aortic and 1106.9 patient-years for mitral valve replacement. The overall 7-year survival rate was 85.1%  ± 3.7%; 86.1%  ± 4.8% and 84.4%  ± 5.4% for aortic and mitral valve replacement, respectively. The 7-year freedom from valve-related death was 93.9%  ± 3.7% and 94.5%  ± 3.2% for aortic and mitral valve replacement, respectively. When early mortality (<30 days) was excluded, these rates were 94.8%  ± 3.1% and 93.8%  ± 3.82%, respectively. Linearized valve-dependent complication rates were determined for structural valve failure (0%/patient-year overall), thrombosis (0.63%/patient-year, all for mitral valve replacement), thromboembolic complications including transient neurologic deficits (0.13%/patient-year overall, 0.5%/patient-year for aortic valve replacement, 0.8%/patient-year for mitral valve replacement), hemorrhagic bleeding (0.64%/patient-year overall, 0.55%/patient-year for aortic valve replacement, 0.09%/patient-year for mitral valve replacement), prosthetic endocarditis (0.28%/patient-year overall, 0.28%/patient-year for aortic valve replacement, 0%/patient-year for mitral valve replacement), and hemolysis (0%/patient-year overall). The CardiaMed mechanical heart valve prostheses meets world standards of safety and efficacy.

Revision Rates after Primary Hip and Knee Replacement in England between 2003 and 2006

PubMed Central

Sibanda, Nokuthaba; Copley, Lynn P; Lewsey, Jim D; Borroff, Mick; Gregg, Paul; MacGregor, Alex J; Pickford, Martin; Porter, Martyn; Tucker, Keith; van der Meulen, Jan H

2008-01-01

Background Hip and knee replacement are some of the most frequently performed surgical procedures in the world. Resurfacing of the hip and unicondylar knee replacement are increasingly being used. There is relatively little evidence on their performance. To study performance of joint replacement in England, we investigated revision rates in the first 3 y after hip or knee replacement according to prosthesis type. Methods and Findings We linked records of the National Joint Registry for England and Wales and the Hospital Episode Statistics for patients with a primary hip or knee replacement in the National Health Service in England between April 2003 and September 2006. Hospital Episode Statistics records of succeeding admissions were used to identify revisions for any reason. 76,576 patients with a primary hip replacement and 80,697 with a primary knee replacement were included (51% of all primary hip and knee replacements done in the English National Health Service). In hip patients, 3-y revision rates were 0.9% (95% confidence interval [CI] 0.8%–1.1%) with cemented, 2.0% (1.7%–2.3%) with cementless, 1.5% (1.1%–2.0% CI) with “hybrid” prostheses, and 2.6% (2.1%–3.1%) with hip resurfacing (p < 0.0001). Revision rates after hip resurfacing were increased especially in women. In knee patients, 3-y revision rates were 1.4% (1.2%–1.5% CI) with cemented, 1.5% (1.1%–2.1% CI) with cementless, and 2.8% (1.8%–4.5% CI) with unicondylar prostheses (p < 0.0001). Revision rates after knee replacement strongly decreased with age. Interpretation Overall, about one in 75 patients needed a revision of their prosthesis within 3 y. On the basis of our data, consideration should be given to using hip resurfacing only in male patients and unicondylar knee replacement only in elderly patients. PMID:18767900

Comparison of survival analysis and palliative care involvement in patients aged over 70 years choosing conservative management or renal replacement therapy in advanced chronic kidney disease.

PubMed

Hussain, Jamilla A; Mooney, Andrew; Russon, Lynne

2013-10-01

There are limited data on the outcomes of elderly patients with chronic kidney disease undergoing renal replacement therapy or conservative management. We aimed to compare survival, hospital admissions and palliative care access of patients aged over 70 years with chronic kidney disease stage 5 according to whether they chose renal replacement therapy or conservative management. Retrospective observational study. Patients aged over 70 years attending pre-dialysis clinic. In total, 172 patients chose conservative management and 269 chose renal replacement therapy. The renal replacement therapy group survived for longer when survival was taken from the time estimated glomerular filtration rate <20 mL/min (p < 0.0001), <15 mL/min (p < 0.0001) and <12 mL/min (p = 0.002). When factors influencing survival were stratified for both groups independently, renal replacement therapy failed to show a survival advantage over conservative management, in patients older than 80 years or with a World Health Organization performance score of 3 or more. There was also a significant reduction in the effect of renal replacement therapy on survival in patients with high Charlson's Comorbidity Index scores. The relative risk of an acute hospital admission (renal replacement therapy vs conservative management) was 1.6 (p < 0.05; 95% confidence interval = 1.14-2.13). A total of 47% of conservative management patients died in hospital, compared to 69% undergoing renal replacement therapy (Renal Registry data). Seventy-six percent of the conservative management group accessed community palliative care services compared to 0% of renal replacement therapy patients. For patients aged over 80 years, with a poor performance status or high co-morbidity scores, the survival advantage of renal replacement therapy over conservative management was lost at all levels of disease severity. Those accessing a conservative management pathway had greater access to palliative care services and were less likely to be admitted to or die in hospital.

Health benefits of dietary fat reduction by a novel fat replacer: Mimix.

PubMed

Ruthig, D J; Sider, D; Meckling-Gill, K A

2001-01-01

The primary goals of this study were to identify any health benefits of the replacement of dietary fat with a novel fat replacer, Mimix, and to assure that the consumption of this fat replacer did not convey any deleterious health effects. Male, weanling, Fischer 344 rats were fed one of six diets containing between 5 and 20% w/w as fat for 8 weeks. These diets included two high fat diets (safflower oil or lard), a low fat diet and three diets where 15% of the fat in the high fat diets was replaced with various amounts of Mimix. When animals were fed a diet rich in saturated fat they consumed significantly more energy than other diet groups. When 15% saturated fat (lard) was replaced with safflower oil animals adjusted their food intake so that no difference in energy intake was observed between the high safflower diet and the low fat and Mimix diets. When the various Mimix fat replacements were compared to animals fed a high fat lard diet there was incomplete compensation of energy intake. Animals fed the high fat lard diet also had higher glucose and total serum cholesterol than their low fat and fat replacement counterparts. Feeding a high fat safflower oil diet to rats resulted in a significantly lower total serum cholesterol and serum triglyceride than all other diets. Replacement of dietary fat with Mimix demonstrated no deleterious effects on the heart, liver and intestinal tract that were all of normal weight, morphology and colour compared to other diet groups. Body composition analysis demonstrated that animals fed high fat diets had higher body fat mass at the expense of lean body mass. This was most obvious for animals fed high fat lard diets who had heavier epididymal fat pads. These data demonstrate that the replacement of dietary fat with the novel fat replacer Mimix can convey a number of health benefits in the absence of any deleterious effects.

Partial knee replacement - slideshow

MedlinePlus

... page: //medlineplus.gov/ency/presentations/100225.htm Partial knee replacement - series—Normal anatomy To use the sharing ... A.M. Editorial team. Related MedlinePlus Health Topics Knee Replacement A.D.A.M., Inc. is accredited ...

Long-life slab replacement concrete.

DOT National Transportation Integrated Search

2015-03-01

This research was initiated following reports of high incidence of cracking on FDOT concrete pavement replacement : slab projects. Field slabs were instrumented for data acquisition from high-early-strength concrete pavement : replacement slabs place...

Effect of steroid replacement on thyroid function and thyroid autoimmunity in Addison's disease with primary hypothyroidism

PubMed Central

Sahoo, Jaya Prakash; Selviambigapathy, Jayakumar; Kamalanathan, Sadishkumar; Nagarajan, K.; Vivekanandan, Muthupillai

2016-01-01

Background: Steroid replacement without thyroxine supplementation normalizes thyroid function test (TFT) in some but not all Addison's disease patients with primary hypothyroidism. Both autoimmune and nonautoimmune mechanisms contribute to this improvement in TFT. However, the documentation of the change in thyroid autoimmunity after cortisol replacement is very limited in the literature. The aim of this study was to determine the effect of steroid replacement on TFT and anti-thyroid peroxidase antibody (anti-TPO-Ab) titer in Addison's disease with primary hypothyroidism. Materials and Methods: This observational study was conducted in a tertiary care center in South India. Six Addison's disease patients with primary hypothyroidism, who were only on steroid replacement, were included in the study. Low serum cortisol (<83 nmol/L) with high plasma adrenocorticotropic hormone (>22 pmol/L) and/or hyperpigmentation of skin/mucous membranes was considered as the diagnostic criteria for Addison's disease. Primary hypothyroidism (both overt and subclinical) was defined as high thyroid stimulating hormone (TSH) with/without low free thyroxine (fT4). TFT and anti-TPO-Ab were performed before and after steroid replacement in all of them. Results: Poststeroid replacement, there was a normalization of TSH in all but one subjects. In overt hypothyroidism patients, fT4 also normalized. The improvement in TFT was not associated with decreasing titer of the anti-TPO-Ab in all six patients. However, there was a significant difference in TSH after steroid replacement compared to the baseline status. Conclusions: The concept of normalization of primary hypothyroidism with cortisol replacement in patients with Addison's disease should be recognized to avoid iatrogenic thyrotoxicosis caused by thyroxine replacement. Both autoimmune and nonautoimmune mechanisms contribute to these alterations. PMID:27042409

Quadriceps force during knee extension in different replacement scenarios with a modular partial prosthesis.

PubMed

Calliess, Tilman; Schado, Ssuheib; Richter, Berna I; Becher, Christoph; Ezechieli, Marco; Ostermeier, Sven

2014-02-01

Previous biomechanical studies have shown that bi-cruciate retaining knee replacement does not significantly alter normal knee kinematics, however, there are no data on the influence of a combined medial and patellofemoral bi-compartimental arthroplasty. The purpose of this in vitro study was to evaluate the effect of different replacement scenarios with a modular partial knee replacement system on the amount of quadriceps force required to extend the knee during an isokinetic extension cycle. Ten human knee specimens were tested in a kinematic knee simulator under (1) physiologic condition and after subsequent implantation of (2) a medial unicondylar and (3) a trochlear replacement. An isokinetic extension cycle of the knee with a constant extension moment of 31 Nm was simulated. The resulting quadriceps extension force was measured from 120° to full knee extension. The quadriceps force curve described a typically sinusoidal characteristic before and after each replacement scenario. The isolated medial replacement resulted in a slightly, but significantly higher maximum quadriceps force (1510 N vs. 1585 N, P = 0.006) as well as the subsequent trochlear replacement showed an additional increase (1801 N, P = 0.008). However, for both replacements no significant difference to the untreated condition could be detected in mid-flexion (10-50°). When considering a bi-compartimental replacement an increase of required maximum quadriceps force needed to extend the knee has to keep in mind. However, the close to physiological movement in mid-flexion suggests that patients with a bi-crutiate retaining arthroplasty might have an advantage in knee stability compared to total knee arthroplasty. Copyright © 2013 Elsevier Ltd. All rights reserved.

Effect of steroid replacement on thyroid function and thyroid autoimmunity in Addison's disease with primary hypothyroidism.

PubMed

Sahoo, Jaya Prakash; Selviambigapathy, Jayakumar; Kamalanathan, Sadishkumar; Nagarajan, K; Vivekanandan, Muthupillai

2016-01-01

Steroid replacement without thyroxine supplementation normalizes thyroid function test (TFT) in some but not all Addison's disease patients with primary hypothyroidism. Both autoimmune and nonautoimmune mechanisms contribute to this improvement in TFT. However, the documentation of the change in thyroid autoimmunity after cortisol replacement is very limited in the literature. The aim of this study was to determine the effect of steroid replacement on TFT and anti-thyroid peroxidase antibody (anti-TPO-Ab) titer in Addison's disease with primary hypothyroidism. This observational study was conducted in a tertiary care center in South India. Six Addison's disease patients with primary hypothyroidism, who were only on steroid replacement, were included in the study. Low serum cortisol (<83 nmol/L) with high plasma adrenocorticotropic hormone (>22 pmol/L) and/or hyperpigmentation of skin/mucous membranes was considered as the diagnostic criteria for Addison's disease. Primary hypothyroidism (both overt and subclinical) was defined as high thyroid stimulating hormone (TSH) with/without low free thyroxine (fT4). TFT and anti-TPO-Ab were performed before and after steroid replacement in all of them. Poststeroid replacement, there was a normalization of TSH in all but one subjects. In overt hypothyroidism patients, fT4 also normalized. The improvement in TFT was not associated with decreasing titer of the anti-TPO-Ab in all six patients. However, there was a significant difference in TSH after steroid replacement compared to the baseline status. The concept of normalization of primary hypothyroidism with cortisol replacement in patients with Addison's disease should be recognized to avoid iatrogenic thyrotoxicosis caused by thyroxine replacement. Both autoimmune and nonautoimmune mechanisms contribute to these alterations.

Differences in the stress distribution in the distal femur between patellofemoral joint replacement and total knee replacement: a finite element study

PubMed Central

2012-01-01

Background Patellofemoral joint replacement is a successful treatment option for isolated patellofemoral osteoarthritis. However, results of later conversion to total knee replacement may be compromised by periprosthetic bone loss. Previous clinical studies have demonstrated a decrease in distal femoral bone mineral density after patellofemoral joint replacement. It is unclear whether this is due to periprosthetic stress shielding. The main objective of the current study was to evaluate the stress shielding effect of prosthetic replacement with 2 different patellofemoral prosthetic designs and with a total knee prosthesis. Methods We developed a finite element model of an intact patellofemoral joint, and finite element models of patellofemoral joint replacement with a Journey PFJ prosthesis, a Richards II prosthesis, and a Genesis II total knee prosthesis. For each of these 4 finite element models, the average Von Mises stress in 2 clinically relevant regions of interest were evaluated during a simulated squatting movement until 120 degrees of flexion. Results During deep knee flexion, in the anterior region of interest, the average Von Mises stress with the Journey PFJ design was comparable to the physiological knee, while reduced by almost 25% for both the Richards II design and the Genesis II total knee joint replacement design. The average Von Mises stress in the supracondylar region of interest was similar for both patellofemoral prosthetic designs and the physiological model, with slightly lower stress for the Genesis II design. Conclusions Patellofemoral joint replacement results in periprosthetic stress-shielding, although to a smaller degree than in total knee replacement. Specific patellofemoral prosthetic design properties may result in differences in femoral stress shielding. PMID:22704638

Liquid and Solid Meal Replacement Products Differentially Affect Postprandial Appetite and Food Intake in Older Adults

PubMed Central

Stull, April J.; Apolzan, John W.; Thalacker-Mercer, Anna E.; Iglay, Heidi B.; Campbell, Wayne W.

2008-01-01

Liquid and solid foods are documented to elicit differential appetitive and food intake responses. This study was designed to assess the influences of liquid vs solid meal replacement products on postprandial appetite ratings and subsequent food intake in healthy older adults. This study used a randomized and crossover design with two 1-day trials (1 week between trials), and 24 adults (12 men and 12 women) aged 50 to 80 years with body mass index (calculated as kg/m2) between 22 and 30 participated. After an overnight fast, the subjects consumed meal replacement products as either a beverage (liquid) or a bar (solid). The meal replacement products provided 25% of each subject's daily estimated energy needs with comparable macro-nutrient compositions. Subjects rated their appetite on a 100 mm quasilogarithmic visual analog scale before and 15, 30, 45, 60, 90, 120, and 150 minutes after consuming the meal replacement product. At minute 120, each subject consumed cooked oatmeal ad libitum to a “comfortable level of fullness.” Postprandial composite (area under the curve from minute 15 to minute 120) hunger was higher (P=0.04) for the liquid vs solid meal replacement products and desire to eat (P=0.15), preoccupation with thoughts of food (P=0.07), and fullness (P=0.25) did not differ for the liquid vs solid meal replacement products. On average, the subjects consumed 13.4% more oatmeal after the liquid vs solid (P=0.006) meal replacement product. These results indicate that meal replacement products in liquid and solid form do not elicit comparable appetitive and ingestive behavior responses and that meal replacement products in liquid form blunt the postprandial decline in hunger and increase subsequent food intake in older adults. PMID:18589034

Original Research: Metabolic alterations from early life thyroxine replacement therapy in male Ames dwarf mice are transient.

PubMed

Darcy, Justin; Fang, Yimin; Hill, Cristal M; McFadden, Sam; Sun, Liou Y; Bartke, Andrzej

2016-10-01

Ames dwarf mice are exceptionally long-lived due to a Prop1 loss of function mutation resulting in deficiency of growth hormone, thyroid-stimulating hormone and prolactin. Deficiency in thyroid-stimulating hormone and growth hormone leads to greatly reduced levels of circulating thyroid hormones and insulin-like growth factor 1, as well as a reduction in insulin secretion. Early life growth hormone replacement therapy in Ames dwarf mice significantly shortens their longevity, while early life thyroxine (T4) replacement therapy does not. Possible mechanisms by which early life growth hormone replacement therapy shortens longevity include deleterious effects on glucose homeostasis and energy metabolism, which are long lasting. A mechanism explaining why early life T4 replacement therapy does not shorten longevity remains elusive. Here, we look for a possible explanation as to why early life T4 replacement therapy does not impact longevity of Ames dwarf mice. We found that early life T4 replacement therapy increased body weight and advanced the age of sexual maturation. We also find that early life T4 replacement therapy does not impact glucose tolerance or insulin sensitivity, and any deleterious effects on oxygen consumption, respiratory quotient and heat production are transient. Lastly, we find that early life T4 replacement therapy has long-lasting effects on bone mineral density and bone mineral content. We suggest that the transient effects on energy metabolism and lack of effects on glucose homeostasis are the reasons why there is no shortening of longevity after early life T4 replacement therapy in Ames dwarf mice. © 2016 by the Society for Experimental Biology and Medicine.

Comparison of radiographic joint space width and magnetic resonance imaging for prediction of knee replacement: A longitudinal case-control study from the Osteoarthritis Initiative.

PubMed

Eckstein, Felix; Boudreau, Robert; Wang, Zhijie; Hannon, Michael J; Duryea, Jeff; Wirth, Wolfgang; Cotofana, Sebastian; Guermazi, Ali; Roemer, Frank; Nevitt, Michael; John, Markus R; Ladel, Christoph; Sharma, Leena; Hunter, David J; Kwoh, C Kent

2016-06-01

To evaluate whether change in fixed-location measures of radiographic joint space width (JSW) and cartilage thickness by MRI predict knee replacement. Knees replaced between 36 and 60 months' follow-up in the Osteoarthritis Initiative were each matched with one control by age, sex and radiographic status. Radiographic JSW was determined from fixed flexion radiographs and subregional femorotibial cartilage thickness from 3 T MRI. Changes between the annual visit before replacement (T0) and 2 years before T0 (T-2) were compared using conditional logistic regression. One hundred and nineteen knees from 102 participants (55.5 % women; age 64.2 ± 8.7 [mean ± SD] years) were studied. Fixed-location JSW change at 22.5 % from medial to lateral differed more between replaced and control knees (case-control [cc] OR = 1.57; 95 % CI: 1.23-2.01) than minimum medial JSW change (ccOR = 1.38; 95 % CI: 1.11-1.71). Medial femorotibial cartilage loss displayed discrimination similar to minimum JSW, and central tibial cartilage loss similar to fixed-location JSW. Location-independent thinning and thickening scores were elevated prior to knee replacement. Discrimination of structural progression between knee pre-placement cases versus controls was stronger for fixed-location than minimum radiographic JSW. MRI displayed similar discrimination to radiography and suggested greater simultaneous cartilage thickening and loss prior to knee replacement. • Fixed-location JSW predicts surgical knee replacement more strongly than minimum JSW. • MRI predicts knee replacement with similar accuracy to radiographic JSW. • MRI reveals greater cartilage thinning and thickening prior to knee replacement.

An evolutionary view on tooth development and replacement in wild Atlantic salmon (Salmo salar L.).

PubMed

Huysseune, A; Witten, P E

2008-01-01

To gain an insight into the evolution of tooth replacement mechanisms, we studied the development of first-generation and replacement teeth on the dentary of wild Atlantic salmon (Salmo salar L.), a protacanthopterygian teleost, using serially sectioned heads of early posthatching stages as well as adults. First-generation teeth develop within the oral epithelium. The anlage of the replacement tooth is first seen as a placode-like thickening of the outer dental epithelium of the predecessor, at its lingual and caudal side. Ongoing development of the replacement tooth germ is characterized by the elaboration of a population of epithelial cells, termed here the middle dental epithelium, apposed to the inner dental epithelium on the lingual side of the tooth germ. Before the formation of the new successor, a single-layered outer dental epithelium segregates from the middle dental epithelium. The dental organs of the predecessor and the successor remain broadly interconnected. The absence of a discrete successional dental lamina in salmon stands in sharp contrast to what is observed in other teleosts, even those that share with salmon the extraosseous formation of replacement teeth. The mode of tooth replacement in Atlantic salmon displays several characters similar to those observed in the shark Squalus acanthias. To interpret similarities in tooth replacement between Atlantic salmon and chondrichthyans as a case of convergence, or to see them as a result of a heterochronic shift, requires knowledge on the replacement process in more basal actinopterygian lineages. The possibility that the middle dental epithelium functionally substitutes for a successional lamina, and could be a source of stem cells, whose descendants subsequently contribute to the placode of the new replacement tooth, needs to be explored.

Common developmental pathways link tooth shape to regeneration

PubMed Central

Fraser, Gareth J.; Bloomquist, Ryan F.; Streelman, J. Todd

2013-01-01

In many non-mammalian vertebrates, adult dentitions result from cyclical rounds of tooth regeneration wherein simple unicuspid teeth are replaced by more complex forms. Therefore and by contrast to mammalian models, the numerical majority of vertebrate teeth develop shape during the process of replacement. Here, we exploit the dental diversity of Lake Malawi cichlid fishes to ask how vertebrates generally replace their dentition and in turn how this process acts to influence resulting tooth morphologies. First, we used immunohistochemistry to chart organogenesis of continually replacing cichlid teeth and discovered an epithelial down-growth that initiates the replacement cycle via a labial proliferation bias. Next, we identified sets of co-expressed genes from common pathways active during de novo, lifelong tooth replacement and tooth morphogenesis. Of note, we found two distinct epithelial cell populations, expressing markers of dental competence and cell potency, which may be responsible for tooth regeneration. Related gene sets were simultaneously active in putative signaling centers associated with the differentiation of replacement teeth with complex shapes. Finally, we manipulated targeted pathways (BMP, FGF, Hh, Notch, Wnt/β-catenin) in vivo with small molecules and demonstrated dose-dependent effects on both tooth replacement and tooth shape. Our data suggest that the processes of tooth regeneration and tooth shape morphogenesis are integrated via a common set of molecular signals. This linkage has subsequently been lost or decoupled in mammalian dentitions where complex tooth shapes develop in first generation dentitions that lack the capacity for lifelong replacement. Our dissection of the molecular mechanics of vertebrate tooth replacement coupled to complex shape pinpoints aspects of odontogenesis that might be re-evolved in the lab to solve problems in regenerative dentistry. PMID:23422830

Technical note: Use of a digital and an optical Brix refractometer to estimate total solids in milk replacer solutions for calves.

PubMed

Floren, H K; Sischo, W M; Crudo, C; Moore, D A

2016-09-01

The Brix refractometer is used on dairy farms and calf ranches for colostrum quality (estimation of IgG concentration), estimation of serum IgG concentration in neonatal calves, and nonsalable milk evaluation of total solids for calf nutrition. Another potential use is to estimate the total solids concentrations of milk replacer mixes as an aid in monitoring feeding consistency. The purpose of this study was to evaluate the use of Brix refractometers to estimate total solids in milk replacer solutions and evaluate different replacer mixes for osmolality. Five different milk replacer powders (2 milk replacers with 28% crude protein and 25% fat and 3 with 22% crude protein and 20% fat) were mixed to achieve total solids concentrations from approximately 5.5 to 18%, for a total of 90 different solutions. Readings from both digital and optical Brix refractometers were compared with total solids. The 2 types of refractometers' readings correlated well with one another. The digital and optical Brix readings were highly correlated with the total solids percentage. A value of 1.08 to 1.47 would need to be added to the Brix reading to estimate the total solids in the milk replacer mixes with the optical and digital refractometers, respectively. Osmolality was correlated with total solids percentage of the mixes, but the relationship was different depending on the type of milk replacer. The Brix refractometer can be beneficial in estimating total solids concentration in milk replacer mixes to help monitor milk replacer feeding consistency. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Effect of feeding a milk replacer to early-weaned pigs on growth, body composition, and small intestinal morphology, compared with suckled littermates.

PubMed

Zijlstra, R T; Whang, K Y; Easter, R A; Odle, J

1996-12-01

Feeding of milk replacer to early-weaned pigs was evaluated in two experiments. In Exp. 1, 18 litters of pigs were either weaned conventionally (d 21), split-weaned and fed milk replacer plus starter diet (d 14 and 21), or weaned and fed milk replacer plus starter diet (d 21). Split weaning combined with feeding a milk replacer increased ADG 22% from d 14 and d 28 compared to conventional weaning (P < .05). Feeding a milk replacer plus starter diet after weaning increased ADG 30% between d 21 and 28 compared to conventional weaning (P < .01). In Experiment 2, four litters of 12 pigs each were divided at d 18 into six heavy and six light pigs and randomized across sow-suckled, milk replacer, or starter diet groups. After 1 wk, pigs fed milk replacer weighed 20% more (P < .001), contained 10% more protein (P < .01) and 17% more fat (P < .05), and had 74% longer villi in the proximal small intestine (P < .001) than suckled pigs. In contrast, pigs fed starter diet weighed 19% less (P < .001), contained 20% less protein and fat (P < .001), and had 28% shorter villi in the proximal small intestine (P < .05) than suckled pigs. Therefore, milk replacer feeding the 1st wk after weaning stimulates pig development, both locally in the small intestine and on a whole-body basis, most likely by an increased energy and nutrient intake. Suckling beyond 18 d postnatally inhibits pigs to reach maximal potential weight gain. In conclusion, milk replacer feeding might be beneficial to reach maximal pig weight gain at weaning.

Long-life slab replacement concrete : [summary].

DOT National Transportation Integrated Search

2015-04-01

Concrete slab replacement projects in Florida have demonstrated a high incidence of : replacement slab cracking. Causes of cracking have not been reliably determined. University of South Florida researchers : sought to identify the factors or : param...

Replacing intrusive thoughts: investigating thought control in relation to OCD symptoms.

PubMed

Ólafsson, Ragnar P; Snorrason, Ívar; Bjarnason, Reynar K; Emmelkamp, Paul M G; Ólason, Daníel Þ; Kristjánsson, Árni

2014-12-01

Control of obsessive thoughts in Obsessive Compulsive Disorder (OCD) involves both avoidance and removal of undesirable intrusive thoughts. Thought suppression tasks tap both of these processes but experimental results have been inconsistent. Experimental tasks allowing more focused study of the processes involved in controlling intrusive thoughts may be needed. In two experiments, control over neutral, standardized intrusive and personal intrusive thoughts was investigated as participants attempted to replace them with neutral thoughts. Non-selected university students (Experiment 1: N = 61) and university students scoring high and low on self-report measure of OC symptoms (Experiment 2: N = 40) performed a computerized thought replacement task. In experiment 1 replacing personal intrusive thoughts took longer than replacing neutral thoughts. Self-reports showed that intrusive thoughts were rated more difficult to replace and were associated with greater thought reoccurrence during replacement, larger emotional reaction and more discomfort. These results were largely replicated in experiment 2. Furthermore, the high OC symptom group experienced greater overall difficulty controlling thoughts on the replacement task, experienced more reoccurrences of personal intrusive thoughts, larger emotional reactions and discomfort associated with them, and felt a greater urge to remove them. All participants were non-clinical university students, and older adults with OCD should be tested. The findings are in line with cognitive behavioural theories of OCD. They support the usefulness of thought replacement as a research paradigm to study thought control in OCD and possibly other psychological conditions characterized by repetitive thoughts. Copyright © 2014 Elsevier Ltd. All rights reserved.

Carbonate replacement of lacustrine gypsum deposits in two Neogene continental basins, eastern Spain

NASA Astrophysics Data System (ADS)

Anadón, P.; Rosell, L.; Talbot, M. R.

1992-07-01

Bedded nonmarine gypsum deposits in the Miocene Teruel and Cabriel basins, eastern Spain, are partly replaced by carbonate. The Libros gypsum (Teruel Graben) is associated with fossiliferous carbonate wackestones and finely laminated, organic matter-rich mudstones which accumulated under anoxic conditions in a meromictic, permanent lake. The gypsum is locally pseudomorphed by aragonite or, less commonly, replaced by calcite. Low δ 13C values indicate that sulphate replacement resulted from bacterial sulphate reduction processes that were favoured by anacrobic conditions and abundant labile organic matter in the sediments. Petrographic evidence and oxygen isotopic composition suggest that gypsum replacement by aragonite occurred soon after deposition. A subsequent return to oxidising conditions caused some aragonite to be replaced by diagenetic gypsum. Native sulphur is associated with some of these secondary gypsum occurrences. The Los Ruices sulphate deposits (Cabriel Basin) contain beds of clastic and selenitic gypsum which are associated with limestones and red beds indicating accumulation in a shallow lake. Calcite is the principal replacement mineral. Bacterial sulphate reduction was insignificant in this basin because of a scarcity of organic matter. Stable isotope composition of diagenetic carbonate indicates that gypsum replacement occurred at shallow burial depths due to contact with dilute groundwaters of meteoric origin. Depositional environment evidently has a major influence upon the diagenetic history of primary sulphate deposits. The quantity of preserved organic matter degradable by sulphate-reducing bacteria is of particular importance and, along with groundwater composition, is the main factor controlling the mechanism of gypsum replacement by carbonate.

Effect on Smoking Cessation of Switching Nicotine Replacement Therapy to Over-the-Counter Status

PubMed Central

Thorndike, Anne N.; Biener, Lois; Rigotti, Nancy A.

2002-01-01

Objectives. This study examined whether the change in nicotine replacement therapy sales from prescription to over the counter (OTC) status affected smoking cessation. Methods. We used the 1993–1999 Massachusetts Tobacco Surveys to compare data from adult current smokers and recent quitters before and after the OTC switch. Results. No significant change over time occurred in the proportion of smokers who used nicotine replacement therapy at a quit attempt in the past year (20.1% pre-OTC vs 21.4% post-OTC), made a quit attempt in the past year (48.1% vs 45.2%), or quit smoking in the past year (8.1% vs 11.1%). Fewer non-Whites used nicotine replacement therapy after the switch (20.7% pre-OTC vs 3.2% post-OTC, P = .002), but the proportion of Whites using nicotine replacement therapy did not change significantly (20.6% vs 24.0%). Conclusions. We observed no increase in Massachusetts smokers' rates of using nicotine replacement therapy, making a quit attempt, or stopping smoking after nicotine replacement therapy became available for OTC sale. There appear to be other barriers to the use of nicotine replacement therapy besides visiting a physician, especially among minority smokers. (Am J Public Health. 2002;92:437–442) PMID:11867326

The optimal hormonal replacement modality selection for multiple organ procurement from brain-dead organ donors

PubMed Central

Mi, Zhibao; Novitzky, Dimitri; Collins, Joseph F; Cooper, David KC

2015-01-01

The management of brain-dead organ donors is complex. The use of inotropic agents and replacement of depleted hormones (hormonal replacement therapy) is crucial for successful multiple organ procurement, yet the optimal hormonal replacement has not been identified, and the statistical adjustment to determine the best selection is not trivial. Traditional pair-wise comparisons between every pair of treatments, and multiple comparisons to all (MCA), are statistically conservative. Hsu’s multiple comparisons with the best (MCB) – adapted from the Dunnett’s multiple comparisons with control (MCC) – has been used for selecting the best treatment based on continuous variables. We selected the best hormonal replacement modality for successful multiple organ procurement using a two-step approach. First, we estimated the predicted margins by constructing generalized linear models (GLM) or generalized linear mixed models (GLMM), and then we applied the multiple comparison methods to identify the best hormonal replacement modality given that the testing of hormonal replacement modalities is independent. Based on 10-year data from the United Network for Organ Sharing (UNOS), among 16 hormonal replacement modalities, and using the 95% simultaneous confidence intervals, we found that the combination of thyroid hormone, a corticosteroid, antidiuretic hormone, and insulin was the best modality for multiple organ procurement for transplantation. PMID:25565890

A stand-replacing fire history in upper montane forests of the southern Rocky Mountains

USGS Publications Warehouse

Margolis, E.Q.; Swetnam, T.W.; Allen, Craig D.

2007-01-01

Dendroecological techniques were applied to reconstruct stand-replacing fire history in upper montane forests in northern New Mexico and southern Colorado. Fourteen stand-replacing fires were dated to 8 unique fire years (1842–1901) using four lines of evidence at each of 12 sites within the upper Rio Grande Basin. The four lines of evidence were (i) quaking aspen (Populus tremuloides Michx.) inner-ring dates, (ii) fire-killed conifer bark-ring dates, (iii) tree-ring width changes or other morphological indicators of injury, and (iv) fire scars. The annual precision of dating allowed the identification of synchronous stand-replacing fire years among the sites, and co-occurrence with regional surface fire events previously reconstructed from a network of fire scar collections in lower elevation pine forests across the southwestern United States. Nearly all of the synchronous stand-replacing and surface fire years coincided with severe droughts, because climate variability created regional conditions where stand-replacing fires and surface fires burned across ecosystems. Reconstructed stand-replacing fires that predate substantial Anglo-American settlement in this region provide direct evidence that stand-replacing fires were a feature of high-elevation forests before extensive and intensive land-use practices (e.g., logging, railroad, and mining) began in the late 19th century.

[Re-operation for Saccular Aneurysm after Ascending Aortic Replacement with Homograft;Report of a Case].

PubMed

Ikeda, Masahiro; Asakura, Toshihisa; Uwabe, Kazuhiko; Morita, Kozo; Iguchi, Atsushi; Niinami, Hiroshi

2017-09-01

A 62-years-old female had undergone ascending aortic replacement with homograft for graft infection and mediastinitis after initial replacement of ascending aorta due to acute type A dissection. Ten years after homograft replacement, follow up computed tomography showed acute growing saccular aneurysm of the homograft without infectious symptoms. We urgently performed Bentall procedure and hemiarch replacement successfully. Pathological diagnosis was true aneurysm of the homograft. She was discharged from hospital without any complication and has been quite uneventful 7 years after surgery. True aneurysm of the homograft is very rare and our case is the 1st report of successful reoperation.

Fleet replacement modeling : final report, July 2009.

DOT National Transportation Integrated Search

2009-07-01

This project focused on two interrelated areas in equipment replacement modeling for fleets. The first area was research-oriented and addressed a fundamental assumption in engineering economic replacement modeling that all assets providing a similar ...

Embedded piezoelectrics for sensing and energy harvesting in total knee replacement units

NASA Astrophysics Data System (ADS)

Wilson, Brooke E.; Meneghini, Michael; Anton, Steven R.

2015-04-01

The knee replacement is the second most common orthopedic surgical intervention in the United States, but currently only 1 in 5 knee replacement patients are satisfied with their level of pain reduction one year after surgery. It is imperative to make the process of knee replacement surgery more objective by developing a data driven approach to ligamentous balance, which increases implant life. In this work, piezoelectric materials are considered for both sensing and energy harvesting applications in total knee replacement implants. This work aims to embed piezoelectric material in the polyethylene bearing of a knee replacement unit to act as self-powered sensors that will aid in the alignment and balance of the knee replacement by providing intraoperative feedback to the surgeon. Postoperatively, the piezoelectric sensors can monitor the structural health of the implant in order to perceive potential problems before they become bothersome to the patient. Specifically, this work will present on the use of finite element modeling coupled with uniaxial compression testing to prove that piezoelectric stacks can be utilized to harvest sufficient energy to power sensors needed for this application.

An approach to solve replacement problems under intuitionistic fuzzy nature

NASA Astrophysics Data System (ADS)

Balaganesan, M.; Ganesan, K.

2018-04-01

Due to impreciseness to solve the day to day problems the researchers use fuzzy sets in their discussions of the replacement problems. The aim of this paper is to solve the replacement theory problems with triangular intuitionistic fuzzy numbers. An effective methodology based on fuzziness index and location index is proposed to determine the optimal solution of the replacement problem. A numerical example is illustrated to validate the proposed method.

Brief history of intermolecular and intersurface forces in complex fluid systems.

PubMed

Israelachvili, Jacob; Ruths, Marina

2013-08-06

We review the developments of ideas, concepts, and theories of intermolecular and intersurface forces and how these were influenced (or ignored) by observations of nature and, later, systematic experimentation. The emphasis of this review is on the way things gradually changed: experimentation replaced rhetoric, measurement and quantification replaced hand waving, energy replaced force in calculations, discrete atoms replaced the (continuum) aether, thermodynamics replaced mechanistic models, randomness and probability replaced certainty, and delicate experiments on the subnanoscale revealed fascinating self-assembling structures and complex behavior of even the simplest systems. We conclude by discussing today's unresolved challenges: how complex "dynamic" multicomponent--especially living biological--systems that receive a continuous supply of energy can be far from equilibrium and not even in any steady state. Such systems, never static but evolving in both space and time, are still far from being understood both experimentally and theoretically.

Blocking VEGF signaling delays development of replacement teeth in zebrafish.

PubMed

Crucke, J; Huysseune, A

2015-01-01

The dentition in zebrafish is extremely and richly vascularized, but the function of the vasculature, in view of the continuous replacement of the teeth, remains elusive. Through application of SU5416, a vascular endothelial growth factor receptor inhibitor, we studied the role of the blood vessels in the dentition of the zebrafish. We were unable to show an effect on the development of first-generation teeth as well as first tooth replacement. However, in juvenile fish, a delay was observed in the developmental state of the replacement tooth compared with what was expected based on the maturation state of the functional tooth. Furthermore, we observed a difference between treated and nontreated fish in the distance between blood vessels and developing replacement teeth. In conclusion, our results provide support for a nutritive, rather than an inductive, function of the vasculature in the process of tooth development and replacement. © International & American Associations for Dental Research 2014.

Replacement of all arginine residues with canavanine in MazF-bs mRNA interferase changes its specificity.

PubMed

Ishida, Yojiro; Park, Jung-Ho; Mao, Lili; Yamaguchi, Yoshihiro; Inouye, Masayori

2013-03-15

Replacement of a specific amino acid residue in a protein with nonnatural analogues is highly challenging because of their cellular toxicity. We demonstrate for the first time the replacement of all arginine (Arg) residues in a protein with canavanine (Can), a toxic Arg analogue. All Arg residues in the 5-base specific (UACAU) mRNA interferase from Bacillus subtilis (MazF-bs(arg)) were replaced with Can by using the single-protein production system in Escherichia coli. The resulting MazF-bs(can) gained a 6-base recognition sequence, UACAUA, for RNA cleavage instead of the 5-base sequence, UACAU, for MazF-bs(arg). Mass spectrometry analysis confirmed that all Arg residues were replaced with Can. The present system offers a novel approach to create new functional proteins by replacing a specific amino acid in a protein with its analogues.

How may a shift towards a more sustainable food consumption pattern affect nutrient intakes of Dutch children?

PubMed

Temme, Elisabeth H M; Bakker, Helena M E; Seves, S Marije; Verkaik-Kloosterman, Janneke; Dekkers, Arnold L; van Raaij, Joop M A; Ocké, Marga C

2015-09-01

Food has a considerable environmental impact. Diets with less meat and dairy reduce environmental impact but may pose nutritional challenges for children. The current modelling study investigates the impact of diets with less or no meat and dairy products on nutrient intakes. Energy and nutrient intakes were assessed for observed consumption patterns (reference) and two replacement scenarios with data from the Dutch National Food Consumption Survey - Young Children (2005-2006). In the replacement scenarios, 30 % or 100 % of the consumed dairy and meat (in grams) was replaced by plant-derived foods with similar use. The Netherlands. Children (n 1279) aged 2-6 years. Partial and full replacement of meat and dairy foods by plant-derived foods reduced SFA intake by 9 % and 26 %, respectively, while fibre intake was 8 % and 29 % higher. With partial replacement, micronutrient intakes were similar, except for lower vitamin B12 intake. After full meat and dairy replacement, mean intakes of Ca, Zn and thiamin decreased by 5-13 %, and vitamin B12 intake by 49 %, while total intake of Fe was higher but of lower bioavailability. With full replacement, the proportion of girls aged 4-6 years with intakes below recommendations was 15 % for thiamin, 10 % for vitamin B12 and 6 % for Zn. Partial replacement of meat and dairy by plant-derived foods is beneficial for children's health by lowering SFA intake, increasing fibre content and maintaining similar micronutrient intakes. When full replacements are made, attention is recommended to ensure adequate thiamin, vitamin B12 and Zn intakes.

Unique method of tooth replacement in durophagous placodont marine reptiles, with new data on the dentition of Chinese taxa

PubMed Central

Neenan, James M; Li, Chun; Rieppel, Olivier; Bernardini, Federico; Tuniz, Claudio; Muscio, Giuseppe; Scheyer, Torsten M

2014-01-01

The placodonts of the Triassic period (˜252–201 mya) represent one of the earliest and most extreme specialisations to a durophagous diet of any known reptile group. Exceptionally enlarged crushing tooth plates on the maxilla, dentary and palatine cooperated to form functional crushing areas in the buccal cavity. However, the extreme size of these teeth, combined with the unusual way they occluded, constrained how replacement occurred. Using an extensive micro-computed tomographic dataset of 11 specimens that span all geographic regions and placodont morphotypes, tooth replacement patterns were investigated. In addition, the previously undescribed dental morphologies and formulae of Chinese taxa are described for the first time and incorporated into the analysis. Placodonts have a unique tooth replacement pattern and results follow a phylogenetic trend. The plesiomorphic Placodus species show many replacement teeth at various stages of growth, with little or no discernible pattern. On the other hand, the more derived cyamodontoids tend to have fewer replacement teeth growing at any one time, replacing teeth unilaterally and/or in functional units, thus maintaining at least one functional crushing area at all times. The highly derived placochelyids have fewer teeth and, as a result, only have one or two replacement teeth in the upper jaw. This supports previous suggestions that these taxa had an alternative diet to other placodonts. Importantly, all specimens show at least one replacement tooth growing at the most posterior palatine tooth plates, indicating increased wear at this point and thus the most efficient functional crushing area. PMID:24517163

Tooth replacement without a dental lamina: the search for epithelial stem cells in Polypterus senegalus.

PubMed

Vandenplas, Sam; De Clercq, Adelbert; Huysseune, Ann

2014-07-01

Most actinopterygians replace their teeth continuously throughout life. To address the question of where and how replacement teeth form in actinopterygians, it is advisable to investigate well-chosen representatives within the lineage. The African bichir, Polypterus senegalus, belongs to the earliest diverged group of the actinopterygian lineage with currently living representatives. Its well characterized dentition, together with its phylogenetic position, make this species an attractive model to answer following questions: (1) when and where does the replacement tooth form and how is it connected with the dental organ of the predecessor, and (2) is there any evidence for the presence of epithelial stem cells, hypothesized to play a role in replacement? Serial sections show that one tooth family can contain up to three members, which are all interconnected by dental epithelium. Replacement teeth develop without the presence of a successional dental lamina. We propose that this is the plesiomorphic condition for tooth replacement in actinopterygians. BrdU pulse-chase experiments reveal cells in the outer and middle dental epithelium, proliferating at the time of initiation of a new replacement tooth. It is tempting to assume that these cell layers provide a stem cell niche. The observed absence of label-retaining cells after long chase times (up to 8 weeks) is held against the light of divergent views on cell cycling properties of stem cells. At present, our data do not support, neither reject, the hypothesis on involvement of epithelial stem cells within the process of continuous tooth replacement. © 2014 Wiley Periodicals, Inc.

42 CFR 441.305 - Replacement of recipients in approved waiver programs.

Code of Federal Regulations, 2011 CFR

2011-10-01

... utilization, but must maintain a record of recipients replaced on this basis. (b) Model waivers. (1) The... exceed 200 recipients at any one time. (2) The agency may replace any individuals who die or become...

42 CFR 441.305 - Replacement of recipients in approved waiver programs.

Code of Federal Regulations, 2010 CFR

2010-10-01

... utilization, but must maintain a record of recipients replaced on this basis. (b) Model waivers. (1) The... exceed 200 recipients at any one time. (2) The agency may replace any individuals who die or become...

23 CFR 710.509 - Functional replacement of real property in public ownership.

Code of Federal Regulations, 2013 CFR

2013-04-01

...) Functional replacement is permitted under State law and the STD elects to provide it. (2) The property in... STD determination that functional replacement is in the public interest. (6) The real property is not...

23 CFR 710.509 - Functional replacement of real property in public ownership.

Code of Federal Regulations, 2011 CFR

2011-04-01

...) Functional replacement is permitted under State law and the STD elects to provide it. (2) The property in... STD determination that functional replacement is in the public interest. (6) The real property is not...

23 CFR 710.509 - Functional replacement of real property in public ownership.

Code of Federal Regulations, 2014 CFR

2014-04-01

...) Functional replacement is permitted under State law and the STD elects to provide it. (2) The property in... STD determination that functional replacement is in the public interest. (6) The real property is not...

Mastracchio during EMU FPS Remove and Replace OPS

NASA Image and Video Library

2014-04-14

Expedition 39 flight engineer Rick Mastracchio poses for a photo with the replacement Fan Pump Separator (FPS) and Extravehicular Mobility Unit (EMU) 3005. Image was taken in the Quest Airlock (A/L) during FPS remove and replace operations.

Bottom ash as aggregate replacement in concrete.

DOT National Transportation Integrated Search

2013-06-01

The objective of the proposed study is to evaluate bottom ash as a partial or total replacement of the fine and coarse aggregate in : concrete. This program will characterize and evaluate available bottom ash sources as potential replacement of both ...

Simulation of Post-Thyroidectomy Treatment Alternatives for Triiodothyronine or Thyroxine Replacement in Pediatric Thyroid Cancer Patients

PubMed Central

Ben-Shachar, Rotem; Huang, Stephen A.; DiStefano, Joseph J.

2012-01-01

Background As in adults, thyroidectomy in pediatric patients with differentiated thyroid cancer is often followed by 131I remnant ablation. A standard protocol is to give normalizing oral thyroxine (T4) or triiodothyronine (T3) after surgery and then withdraw it for 2 to 6 weeks. Thyroid remnants or metastases are treated most effectively when serum thyrotropin (TSH) is high, but prolonged withdrawals should be avoided to minimize hypothyroid morbidity. Methods A published feedback control system model of adult human thyroid hormone regulation was modified for children using pediatric T4 kinetic data. The child model was developed from data for patients ranging from 3 to 9 years old. We simulated a range of T4 and T3 replacement protocols for children, exploring alternative regimens for minimizing the withdrawal period, while maintaining normal or suppressed TSH during replacement. The results are presented with the intent of providing a quantitative basis to guide further studies of pediatric treatment options. Replacement was simulated for up to 3 weeks post-thyroidectomy, followed by various withdrawal periods. T4 vs. T3 replacement, remnant size, dose size, and dose frequency were tested for effects on the time for TSH to reach 25 mU/L (withdrawal period). Results For both T3 and T4 replacement, higher doses were associated with longer withdrawal periods. T3 replacement yielded shorter withdrawal periods than T4 replacement (up to 3.5 days versus 7–10 days). Higher than normal serum T3 concentrations were required to normalize or suppress TSH during T3 monotherapy, but not T4 monotherapy. Larger remnant sizes resulted in longer withdrawal periods if T4 replacement was used, but had little effect for T3 replacement. Conclusions T3 replacement yielded withdrawal periods about half those for T4 replacement. Higher than normal hormone levels under T3 monotherapy can be partially alleviated by more frequent, smaller doses (e.g., twice a day). LT4 may be the preferred option for most children, given the convenience of single daily dosing and familiarity of pediatric endocrinologists with its administration. Remnant effects on withdrawal period highlight the importance of minimizing remnant size. PMID:22578300

Protein and calorie prescription for children and young adults receiving continuous renal replacement therapy: a report from the Prospective Pediatric Continuous Renal Replacement Therapy Registry Group.

PubMed

Zappitelli, Michael; Goldstein, Stuart L; Symons, Jordan M; Somers, Michael J G; Baum, Michelle A; Brophy, Patrick D; Blowey, Douglas; Fortenberry, James D; Chua, Annabelle N; Flores, Francisco X; Benfield, Mark R; Alexander, Steven R; Askenazi, David; Hackbarth, Richard; Bunchman, Timothy E

2008-12-01

Few published reports describe nutrition provision for critically ill children and young adults with acute kidney injury receiving continuous renal replacement therapy. The goals of this study were to describe feeding practices in pediatric continuous renal replacement therapy and to evaluate factors associated with over- and under-prescription of protein and calories. Retrospective database study. Multicenter study in pediatric critical care units. Patients with acute kidney injury (estimated glomerular filtration rate < 75 mL/min/1.73 m at continuous renal replacement therapy initiation) enrolled in the Prospective Pediatric Continuous Renal Replacement Therapy Registry. None. Nutrition variables: initial and maximal protein (g/kg/day) and caloric (kcal/kg/day) prescription and predicted resting energy expenditure (kcal/kg/day). We determined factors predicting initial and maximal protein and caloric prescription by multivariate analysis. One hundred ninety-five patients (median [interquartile range] age = 8.1 [12.8] yrs, 56.9% men) were studied. Mean protein and caloric prescriptions at continuous renal replacement therapy initiation were 1.3 +/- 1.5 g/kg/day (median, 1.0; range, 0-10) and 37 +/- 27 kcal/kg/day (median, 32; range, 0-107). Mean maximal protein and caloric prescriptions during continuous renal replacement therapy were 2.0 +/- 1.5 g/kg/day (median, 1.7; range, 0-12) and 48 +/- 32 kcal/kg/day (median, 43; range, 0-117). Thirty-four percent of patients were initially prescribed < 1 g/kg/day protein; 23% never attained > 1 g/kg/day protein prescription. By continuous renal replacement therapy day 5, median protein prescribed was > 2 g/kg/day. Protein prescription practices differed substantially between medical centers with 5 of 10 centers achieving maximal protein prescription of > 2 g/kg/day in > or = 40% of patients. Caloric prescription exceeded predicted resting energy expenditure by 30%-100%. Factors independently associated with maximal protein and caloric prescription while on continuous renal replacement therapy were younger age, initial protein and caloric prescription and number of continuous renal replacement therapy treatment days (p < 0.05). Protein prescription in pediatric continuous renal replacement therapy may be inadequate. Inter-center variation exists with respect to nutrition prescription. Feeding practice standardization and research in pediatric acute kidney injury nutrition are essential to begin providing evidence-based feeding recommendations.

Description of the rates, trends and surgical burden associated with revision for prosthetic joint infection following primary and revision knee replacements in England and Wales: an analysis of the National Joint Registry for England, Wales, Northern Ireland and the Isle of Man.

PubMed

Lenguerrand, Erik; Whitehouse, Michael R; Beswick, Andrew D; Toms, Andrew D; Porter, Martyn L; Blom, Ashley W

2017-07-10

To describe the prevalence rates of revision surgery for the treatment of prosthetic joint infection (PJI) for patients undergoing knee replacement, their time trends, the cumulative incidence function of revision for PJI and estimate the burden of PJI at health service level. We analysed revision knee replacements performed due to a diagnosis of PJI and the linked index procedures recorded in the National Joint Registry from 2003 to 2014 for England and Wales. The cohort analysed consisted of 679 010 index primary knee replacements, 33 920 index revision knee replacements and 8247 revision total knee replacements performed due to a diagnosis of PJI. The prevalence rates, their time trends investigated by time from index surgery to revision for PJI, cumulative incidence functions and the burden of PJI (total procedures) were calculated. Overall linear trends were investigated with log-linear regression. The incidence of revision total knee replacement due to PJI at 2 years was 3.2/1000 following primary and 14.4/1000 following revision knee replacement, respectively. The prevalence of revision due to PJI in the 3 months following primary knee replacement has risen by 2.5-fold (95% CI 1.2 to 5.3) from 2005 to 2013 and 7.5-fold (95% CI 1.0 to 56.1) following revision knee replacement. Over 1000 procedures per year are performed as a consequence of knee PJI, an increase of 2.8 from 2005 to 2013. Overall, 75% of revisions were two-stage with an increase in use of single-stage from 7.9% in 2005 to 18.8% in 2014. Although the risk of revision due to PJI following knee replacement is low, it is rising, and coupled with the established and further predicted increased incidence of both primary and revision knee replacements, this represents an increasing and substantial treatment burden for orthopaedic service delivery in England and Wales. This has implications for future service design and the funding of individual and specialist centres. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Description of the rates, trends and surgical burden associated with revision for prosthetic joint infection following primary and revision knee replacements in England and Wales: an analysis of the National Joint Registry for England, Wales, Northern Ireland and the Isle of Man

PubMed Central

Lenguerrand, Erik; Whitehouse, Michael R; Beswick, Andrew D; Toms, Andrew D; Porter, Martyn L; Blom, Ashley W

2017-01-01

Objectives To describe the prevalence rates of revision surgery for the treatment of prosthetic joint infection (PJI) for patients undergoing knee replacement, their time trends, the cumulative incidence function of revision for PJI and estimate the burden of PJI at health service level. Design We analysed revision knee replacements performed due to a diagnosis of PJI and the linked index procedures recorded in the National Joint Registry from 2003 to 2014 for England and Wales. The cohort analysed consisted of 679 010 index primary knee replacements, 33 920 index revision knee replacements and 8247 revision total knee replacements performed due to a diagnosis of PJI. The prevalence rates, their time trends investigated by time from index surgery to revision for PJI, cumulative incidence functions and the burden of PJI (total procedures) were calculated. Overall linear trends were investigated with log-linear regression. Results The incidence of revision total knee replacement due to PJI at 2 years was 3.2/1000 following primary and 14.4/1000 following revision knee replacement, respectively. The prevalence of revision due to PJI in the 3 months following primary knee replacement has risen by 2.5-fold (95% CI 1.2 to 5.3) from 2005 to 2013 and 7.5-fold (95% CI 1.0 to 56.1) following revision knee replacement. Over 1000 procedures per year are performed as a consequence of knee PJI, an increase of 2.8 from 2005 to 2013. Overall, 75% of revisions were two-stage with an increase in use of single-stage from 7.9% in 2005 to 18.8% in 2014. Conclusions Although the risk of revision due to PJI following knee replacement is low, it is rising, and coupled with the established and further predicted increased incidence of both primary and revision knee replacements, this represents an increasing and substantial treatment burden for orthopaedic service delivery in England and Wales. This has implications for future service design and the funding of individual and specialist centres. PMID:28698316

Rosetta Structure Prediction as a Tool for Solving Difficult Molecular Replacement Problems.

PubMed

DiMaio, Frank

2017-01-01

Molecular replacement (MR), a method for solving the crystallographic phase problem using phases derived from a model of the target structure, has proven extremely valuable, accounting for the vast majority of structures solved by X-ray crystallography. However, when the resolution of data is low, or the starting model is very dissimilar to the target protein, solving structures via molecular replacement may be very challenging. In recent years, protein structure prediction methodology has emerged as a powerful tool in model building and model refinement for difficult molecular replacement problems. This chapter describes some of the tools available in Rosetta for model building and model refinement specifically geared toward difficult molecular replacement cases.

Medical Surveillance Monthly Report (MSMR). Volume 22, Number 5, May 2015

DTIC Science & Technology

2015-05-01

aTotal column equals one joint replacement per person per period. bAn individual could be counted once in each of the types of joint replacements. cRate...Percentages of joint replace- ment cases who remained in service or had left service, 2 years post-joint replacement, by gender , active component...Musculoskeletal-related disability in US Army personnel: prevalence, gender and military occupational specialties. J Occup Environ Med. 1997;39(1):68–78

Consequences of tooth loss: 2. Dentist considerations--restorative problems and implications.

PubMed

Craddock, Helen L

2010-01-01

Partial tooth loss is much less well tolerated by patients than was previously the case and, on occasions, when extraction is inevitable, they may seek prosthetic replacement. This paper explores some of the consequences of tooth loss that may cause difficulties in tooth replacement, particularly if replacement is delayed for some time. An awareness of potential difficulties, particularly with posterior tooth replacement, will allow clinicians to make treatment decisions in the light of current evidence.

Radiopaque Marker Addition During Aortic Root Replacement With the Use of a Freestyle Porcine Bioprosthesis.

PubMed

Crowley, Olivia M; Doty, John R

2017-07-01

Aortic root replacement is indicated for aortic root aneurysm, small aortic root, and most root abscesses. This report describes the placement of a radiopaque marker during aortic root replacement using a Freestyle porcine bioprosthesis. This marker is a useful landmark during fluoroscopy for transcatheter valve-in-valve aortic valve replacement in the event of bioprosthesis degeneration. Copyright © 2017 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

CORESAFE: A Formal Approach against Code Replacement Attacks on Cyber Physical Systems

DTIC Science & Technology

2018-04-19

AFRL-AFOSR-JP-TR-2018-0035 CORESAFE:A Formal Approach against Code Replacement Attacks on Cyber Physical Systems Sandeep Shukla INDIAN INSTITUTE OF...Formal Approach against Code Replacement Attacks on Cyber Physical Systems 5a.  CONTRACT NUMBER 5b.  GRANT NUMBER FA2386-16-1-4099 5c.  PROGRAM ELEMENT...Institute of Technology Kanpur India Final Report for AOARD Grant “CORESAFE: A Formal Approach against Code Replacement Attacks on Cyber Physical

Navy Ohio Replacement (SSBN[X]) Ballistic Missile Submarine Program: Background and Issues for Congress

DTIC Science & Technology

2016-04-05

Navy Ohio Replacement (SSBN[ X ]) Ballistic Missile Submarine Program: Background and Issues for Congress Ronald O’Rourke Specialist in Naval...Affairs April 5, 2016 Congressional Research Service 7-5700 www.crs.gov R41129 Navy Ohio Replacement (SSBN[ X ]) Ballistic Missile Submarine...as the SSBN( X ) program, as the Navy’s top priority program. The Navy wants to procure the first Ohio replacement boat in FY2021, and the $773.1

Extent of tooth decay in the mouth and increased need for replacement of dental restorations: the New England Children's Amalgam Trial.

PubMed

Trachtenberg, Felicia; Maserejian, Nancy Nairi; Tavares, Mary; Soncini, Jennifer Ann; Hayes, Catherine

2008-01-01

The purpose of this study was to assess the relationship between baseline caries experience and the restoration replacement rate in children. The 5-year New England Children's Amalgam Trial recruited 534 6- to 10-year-old children with 2 or more carious posterior teeth. The association between decoy and longevity of restorations was assessed. Restorations with no follow-up (N = 391) were excluded from analysis. The average follow-up was 3.0 +/- 1.6 years in 489 children. Restorations with follow-up (N = 3,604) were placed in mouths with a median of 15 dfs/DFS and 8 dft/DFT. The need for replacement increased significantly (P < or = .001) with increasing numbers of dfs/DFS and dft/DFT. After 5 years of follow-up, at least 15% of restorations in a mouth with > or = 14 dfs/DFS needed replacement, compared to 9% for 2 to 5 dfs/DFS. Comparing dft/DFT after 5 years of follow-up, there was a 23% replacement rate for > or = 12 dft/DFT compared to 10% for 2 to 3 dft/DFT. Decoy in the mouth had a greater association with the need for replacement due to new caries compared to replacement due to recurrent caries. Children with more decoy at the time of restoration placement were at higher risk for replacement of restorations.

Changing of the guard: reducing infection when replacing neural pacemakers.

PubMed

Pepper, Joshua; Meliak, Lara; Akram, Harith; Hyam, Jonathan; Milabo, Catherine; Candelario, Joseph; Foltynie, Thomas; Limousin, Patricia; Curtis, Carmel; Hariz, Marwan; Zrinzo, Ludvic

2017-04-01

OBJECTIVE Infection of deep brain stimulation (DBS) hardware has a significant impact on patient morbidity. Previous experience suggests that infection rates appear to be higher after implantable pulse generator (IPG) replacement surgery than after the de novo DBS procedure. In this study the authors examine the effect of a change in practice during DBS IPG replacements at their institution. METHODS Starting in January 2012, patient screening for methicillin-resistant Staphylococcus aureus (MRSA) and, and where necessary, eradication was performed prior to elective DBS IPG change. Moreover, topical vancomycin was placed in the IPG pocket during surgery. The authors then prospectively examined the infection rate in patients undergoing DBS IPG replacement at their center over a 3-year period with at least 9 months of follow-up. RESULTS The total incidence of infection in this prospective consecutive series of 101 IPG replacement procedures was 0%, with a mean follow-up duration of 24 ± 11 months. This was significantly lower than the authors' previously published historical control group, prior to implementing the change in practice, where the infection rate for IPG replacement was 8.5% (8/94 procedures; p = 0.003). CONCLUSIONS This study suggests that a change in clinical practice can significantly lower infection rates in patients undergoing DBS IPG replacement. These simple measures can minimize unnecessary surgery, loss of benefit from chronic stimulation, and costly hardware replacement, further improving the cost efficacy of DBS therapies.

Incidence and Patient Outcomes in Renal Replacement Therapy After Orthotopic Liver Transplant.

PubMed

Ayhan, Asude; Ersoy, Zeynep; Ulas, Aydin; Zeyneloglu, Pinar; Pirat, Arash; Haberal, Mehmet

2017-02-01

Our objective was to evaluate the incidence of renal replacement therapy after orthotopic liver transplant and to evaluate and analyze patient outcomes. We performed a retrospective analysis of 177 consecutive patients at a tertiary care unit who underwent orthotopic liver transplant between January 2010 and June 2016. Patients who were admitted to the intensive care unit after orthotopic liver transplant and who required renal replacement therapy were included. A total of 177 (79 adult, 98 pediatric) orthotopic liver transplants were performed during the study period. Of these, 35 patients (19%) required renal replacement therapy during the early posttransplantation period. After excluding 5 patients with previous chronic renal failure, 30 patients (17%; 20 adult [25% ], 10 pediatric [10% ]) with acute kidney injury required renal replacement therapy. The mean patient age was 31.1 ± 20.0 years, with a mean Model for End-stage Liver Disease score of 16.7 ± 12.3. Of the patients with acute kidney injury who underwent renal replacement therapy, in-hospital mortality was 23.3% (7 of 30 patients), and 40% remained on dialysis. No significant difference was seen in mortality between early versus delayed initiation of renal replacement therapy in patients with stage 3 acute kidney injury (P = .17). Of liver transplant recipients who present with acute kidney injury, 19% require renal replacement therapy, and in-hospital mortality is 20% in the early postoperative period.

Development of a vancomycin dosing approach for critically ill patients receiving hybrid hemodialysis using Monte Carlo simulation.

PubMed

Lewis, Susan J; Mueller, Bruce A

2018-01-01

Prolonged intermittent renal replacement therapy is an increasingly popular treatment for acute kidney injury in critically ill patients that runs at different flow rates and durations than conventional hemodialysis or continuous renal replacement therapies. Pharmacokinetic studies conducted in patients receiving prolonged intermittent renal replacement therapy are scarce; consequently, clinicians are challenged to dose antibiotics effectively. The purpose of this study was to develop vancomycin dosing recommendations for patients receiving prolonged intermittent renal replacement therapy. Monte Carlo simulations were performed in thousands of virtual patients derived from previously published demographic, pharmacokinetic, and dialytic information derived from critically ill patients receiving vancomycin and other forms of renal replacement therapy. We conducted "in silico" vancomycin pharmacokinetic/pharmacodynamics analyses in these patients receiving prolonged intermittent renal replacement therapy to determine what vancomycin dose would achieve vancomycin 24-h area under the curve (AUC 24h ) of 400-700 mg·h/L, a target associated with positive clinical outcomes. Nine different vancomycin dosing regimens were tested using four different, commonly used prolonged intermittent renal replacement therapy modalities. A dosing nomogram based on serum concentration data achieved after the third dose was developed to individualize vancomycin therapy. An initial vancomycin dose of 15 or 20 mg/kg immediately followed by 15 mg/kg after subsequent prolonged intermittent renal replacement therapy treatments achieved AUC 24h of ≥400 mg·h/L for ≥90% of patients regardless of prolonged intermittent renal replacement therapy duration, modality, or time of vancomycin dose relative to prolonged intermittent renal replacement therapy. Many patients experienced AUC 24h of ≥700 mg·h/L, but once the dosing nomogram was applied to serum concentrations obtained after the third vancomycin dose, 67%-88% of patients achieved AUC 24h of 400-700 mg·h/L. An initial loading dose of 15-20 mg/kg followed by a maintenance regimen of 15 mg/kg after every prolonged intermittent renal replacement therapy session coupled with serum concentration monitoring should be used to individualize vancomycin dosing. These predictions need clinical verification.

Precast concrete replacement slabs for bridge decks.

DOT National Transportation Integrated Search

1982-01-01

The report illustrates and evaluates the first use in Virginia of precast concrete replacement slabs for bridge decks. It shows that a bridge deck can be replaced with the precast slabs while traffic is maintained in the adjacent traffic lane. The qu...

Redesigning a joint replacement program using Lean Six Sigma in a Veterans Affairs hospital.

PubMed

Gayed, Benjamin; Black, Stephen; Daggy, Joanne; Munshi, Imtiaz A

2013-11-01

In April 2009, an analysis of joint replacement surgical procedures at the Richard L. Roudebush Veterans Affairs Medical Center, Indianapolis, Indiana, revealed that total hip and knee replacements incurred $1.4 million in non-Veterans Affairs (VA) care costs with an average length of stay of 6.1 days during fiscal year 2008. The Joint Replacement Program system redesign project was initiated following the Vision-Analysis-Team-Aim-Map-Measure-Change-Sustain (VA-TAMMCS) model to increase efficiency, decrease length of stay, and reduce non-VA care costs. To determine the effectiveness of Lean Six Sigma process improvement methods applied in a VA hospital. Perioperative processes for patients undergoing total joint replacement were redesigned following the VA-TAMMCS model--the VA's official, branded method of Lean Six Sigma process improvement. A multidisciplinary team including the orthopedic surgeons, frontline staff, and executive management identified waste in the current processes and initiated changes to reduce waste and increase efficiency. Data collection included a 1-year baseline period and a 20-month sustainment period. The primary endpoint was length of stay; a secondary analysis considered non-VA care cost reductions. Length of stay decreased 36% overall, decreasing from 5.3 days during the preproject period to 3.4 days during the 20-month sustainment period (P < .001). Non-VA care was completely eliminated for patients undergoing total hip and knee replacement at the Richard L. Roudebush Veterans Affairs Medical Center, producing an estimated return on investment of $1 million annually when compared with baseline cost and volumes. In addition, the volume of total joint replacements at this center increased during the data collection period. The success of the Joint Replacement Program demonstrates that VA-TAMMCS is an effective tool for Lean and Six Sigma process improvement initiatives in a surgical practice, producing a 36% sustained reduction in length of stay and completely eliminating non-VA care for total hip and knee replacements while increasing total joint replacement volume at this medical center.

The management of failed ankle replacement.

PubMed

Kotnis, R; Pasapula, C; Anwar, F; Cooke, P H; Sharp, R J

2006-08-01

Advances in the design of the components for total ankle replacement have led to a resurgence of interest in this procedure. Between January 1999 and December 2004, 16 patients with a failed total ankle replacement were referred to our unit. In the presence of infection, a two-stage salvage procedure was planned. The first involved the removal of the components and the insertion of a cement spacer. Definitive treatment options included hindfoot fusion with a circular frame or amputation. When there was no infection, a one-stage salvage procedure was planned. Options included hindfoot fusion with an intramedullary nail or revision total ankle replacement. When there was suspicion of infection, a percutaneous biopsy was performed. The patients were followed up for a minimum of 12 months. Of the 16 patients, 14 had aseptic loosening, five of whom underwent a revision total ankle replacement and nine a hindfoot fusion. Of the two with infection, one underwent fusion and the other a below-knee amputation. There were no cases of wound breakdown, nonunion or malunion. Management of the failed total ankle replacement should be performed by experienced surgeons and ideally in units where multidisciplinary support is available. Currently, a hindfoot fusion appears to be preferable to a revision total ankle replacement.

A signature of dynamic biogeography: enclaves indicate past species replacement.

PubMed

Wielstra, B; Burke, T; Butlin, R K; Arntzen, J W

2017-12-13

Understanding how species have replaced each other in the past is important to predicting future species turnover. While past species replacement is difficult to detect after the fact, the process may be inferred from present-day distribution patterns. Species with abutting ranges sometimes show a characteristic distribution pattern, where a section of one species range is enveloped by that of the other. Such an enclave could indicate past species replacement: when a species is partly supplanted by a competitor, but a population endures locally while the invading species moves around and past it, an enclave forms. If the two species hybridize and backcross, the receding species is predicted to leave genetic traces within the expanding one under a scenario of species replacement. By screening dozens of genes in hybridizing crested newts, we uncover genetic remnants of the ancestral species, now inhabiting an enclave, in the range of the surrounding invading species. This independent genetic evidence supports the past distribution dynamics we predicted from the enclave. We suggest that enclaves provide a valuable tool in understanding historical species replacement, which is important because a major conservation concern arising from anthropogenic climate change is increased species replacement in the future. © 2017 The Authors.

Optimal Elastomeric Scaffold Leaflet Shape for Pulmonary Heart Valve Leaflet Replacement

PubMed Central

Fan, Rong; Bayoumi, Ahmed S.; Chen, Peter; Hobson, Christopher M.; Wagner, William R.; Mayer, John E.; Sacks, Michael S.

2012-01-01

Surgical replacement of the pulmonary valve (PV) is a common treatment option for congenital pulmonary valve defects. Engineered tissue approaches to develop novel PV replacements are intrinsically complex, and will require methodical approaches for their development. Single leaflet replacement utilizing an ovine model is an attractive approach in that candidate materials can be evaluated under valve level stresses in blood contact without the confounding effects of a particular valve design. In the present study an approach for optimal leaflet shape design based on finite element (FE) simulation of a mechanically anisotropic, elastomeric scaffold for PV replacement is presented. The scaffold was modeled as an orthotropic hyperelastic material using a generalized Fung-type constitutive model. The optimal shape of the fully loaded PV replacement leaflet was systematically determined by minimizing the difference between the deformed shape obtained from FE simulation and an ex-vivo microCT scan of a native ovine PV leaflet. Effects of material anisotropy, dimensional changes of PV root, and fiber orientation on the resulting leaflet deformation were investigated. In-situ validation demonstrated that the approach could guide the design of the leaflet shape for PV replacement surgery. PMID:23294966

Report on the National Eye Institute Audacious Goals Initiative: Replacement of Retinal Ganglion Cells from Endogenous Cell Sources.

PubMed

Vetter, Monica L; Hitchcock, Peter F

2017-03-01

This report emerges from a workshop convened by the National Eye Institute (NEI) as part of the "Audacious Goals Initiative" (AGI). The workshop addressed the replacement of retinal ganglion cells (RGCs) from exogenous and endogenous sources, and sought to identify the gaps in our knowledge and barriers to progress in devising cellular replacement therapies for diseases where RGCs die. Here, we briefly review relevant literature regarding common diseases associated with RGC death, the genesis of RGCs in vivo, strategies for generating transplantable RGCs in vitro, and potential endogenous cellular sources to regenerate these cells. These topics provided the clinical and scientific context for the discussion among the workshop participants and are relevant to efforts that may lead to therapeutic approaches for replacing RGCs. This report also summarizes the content of the workshop discussion, which focused on: (1) cell sources for RGC replacement and regeneration, (2) optimizing integration, survival, and synaptogenesis of new RGCs, and (3) approaches for assessing the outcomes of RGC replacement therapies. We conclude this report with a summary of recommendations, based on the workshop discussions, which may guide vision scientists seeking to develop therapies for replacing RGCs in humans.

Replacement of Fine Aggregate by using Recyclable Materials in Paving Blocks

NASA Astrophysics Data System (ADS)

Koganti, Shyam Prakash; Hemanthraja, Kommineni; Sajja, Satish

2017-08-01

Cement concrete paving blocks are precast hard products complete out of cement concrete. The product is made in various sizes and shapes like square, round and rectangular blocks of different dimensions with designs for interlocking of adjacent tiles blocks. Several Research Works have been carried out in the past to study the possibility of utilizing waste materials and industrial byproducts in the manufacturing of paver blocks. Various industrial waste materials like quarry dust, glass powder, ceramic dust and coal dust are used as partial replacement of fine aggregate and assessed the strength parameters and compared the profit percentages after replacement with waste materials. Quarry dust can be replaced by 20% and beyond that the difference in strength is not much higher but considering cost we can replace upto 40% so that we can get a profit of almost 10%. Similarly we can replace glass powder and ceramic dust by 20% only beyond that there is decrement in strength and even with 20% replacement we can get 1.34 % and 2.42% of profit. Coal dust is not suitable for alternative material as fine aggregate as it reduces the strength.

47 CFR 13.17 - Replacement license.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 47 Telecommunication 1 2010-10-01 2010-10-01 false Replacement license. 13.17 Section 13.17 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL COMMERCIAL RADIO OPERATORS General § 13.17 Replacement license. (a) Each licensee or permittee whose original document is lost, mutilated, or destroyed must...

78 FR 29669 - Airworthiness Directives; DASSAULT AVIATION Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2013-05-21

... Maintenance Procedure 26-20-2, ``Removal of Pyrotechnical Cartridge for Check/Replacement,'' dated October... Maintenance Procedure 26-20-2, ``Removal of Pyrotechnical Cartridge for Check/ Replacement,'' dated October... Maintenance Procedure 26-20-2, ``Removal of Pyrotechnical Cartridge for Check/Replacement,'' dated October...

SOLVENT DESIGN UNDER VARYING ENVIRONMENTAL REQUIREMENTS

EPA Science Inventory

There is currently a great need to replace many solvents that are commonly used by industry and the public, but whose continued use entails a number of human health and environmental risks. One issue hampering solvent replacement is the general thought that replacement, particul...

Applying stand replacement prescribed fires in Alaska

Treesearch

Larry A. Vanderlinden

1996-01-01

Stand replacement prescribed burning has been applied in Alaska on several occasions. Based on that experience, perspectives can be provided, issues can be discussed, and keys to success can be identified that are applicable to stand replacement prescribed burning activities in areas outside Alaska.

38 CFR 17.351 - Grants for the replacement and upgrading of equipment at Veterans Memorial Medical Center.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Philippines § 17.351 Grants for the replacement and upgrading of equipment at Veterans Memorial Medical Center. Grants to assist the Republic of the Philippines in the replacement and upgrading of equipment and in...

38 CFR 17.351 - Grants for the replacement and upgrading of equipment at Veterans Memorial Medical Center.

Code of Federal Regulations, 2011 CFR

2011-07-01

... Philippines § 17.351 Grants for the replacement and upgrading of equipment at Veterans Memorial Medical Center. Grants to assist the Republic of the Philippines in the replacement and upgrading of equipment and in...

38 CFR 17.351 - Grants for the replacement and upgrading of equipment at Veterans Memorial Medical Center.

Code of Federal Regulations, 2014 CFR

2014-07-01

... Philippines § 17.351 Grants for the replacement and upgrading of equipment at Veterans Memorial Medical Center. Grants to assist the Republic of the Philippines in the replacement and upgrading of equipment and in...

38 CFR 17.351 - Grants for the replacement and upgrading of equipment at Veterans Memorial Medical Center.

Code of Federal Regulations, 2013 CFR

2013-07-01

... Philippines § 17.351 Grants for the replacement and upgrading of equipment at Veterans Memorial Medical Center. Grants to assist the Republic of the Philippines in the replacement and upgrading of equipment and in...

38 CFR 17.351 - Grants for the replacement and upgrading of equipment at Veterans Memorial Medical Center.

Code of Federal Regulations, 2012 CFR

2012-07-01

... Philippines § 17.351 Grants for the replacement and upgrading of equipment at Veterans Memorial Medical Center. Grants to assist the Republic of the Philippines in the replacement and upgrading of equipment and in...

PROGRAM FOR THE IDENTIFICATION AND REPLACEMENT OF ENDOCRINE DISRUPTING CHEMICALS

EPA Science Inventory

A computer software program is being developed to aid in the identification and replacement of endocrine disrupting chemicals (EDC). This program will be comprised of two distinct areas of research: identification of potential EDC nd suggstions for replacing those potential EDC. ...

Navy Stock Point Local Unique Computer Programs: An Analysis for Transition and Management Under the Stock Point ADP Replacement (SPAR) Project.

DTIC Science & Technology

1987-03-01

Project (SPAR). An impor- tant issue of the replacement will be the conversion of existing co uter software to allow transition from the current... issue of the replacement will be the conversion of existing computer software to allow transition from the current hardware environment to the replacement...36 G. LOCAL PROGRAM C1/C2 CONVERSION CONTRACT . . . 38 5 H. LOCAL PROGRAM COMMONALITY ISSUES ....... 41 I. SUMMARY

Astronaut tool development: An orbital replaceable unit-portable handhold

NASA Technical Reports Server (NTRS)

Redmon, John W., Jr.

1989-01-01

A tool to be used during astronaut Extra-Vehicular Activity (EVA) replacement of spent or defective electrical/electronic component boxes is described. The generation of requirements and design philosophies are detailed, as well as specifics relating to mechanical development, interface verifications, testing, and astronaut feedback. Findings are presented in the form of: (1) a design which is universally applicable to spacecraft component replacement, and (2) guidelines that the designer of orbital replacement units might incorporate to enhance spacecraft on-orbit maintainability and EVA mission safety.

Replacing missing data between airborne SAR coherent image pairs

DOE PAGES

Musgrove, Cameron H.; West, James C.

2017-07-31

For synthetic aperture radar systems, missing data samples can cause severe image distortion. When multiple, coherent data collections exist and the missing data samples do not overlap between collections, there exists the possibility of replacing data samples between collections. For airborne radar, the known and unknown motion of the aircraft prevents direct data sample replacement to repair image features. Finally, this paper presents a method to calculate the necessary phase corrections to enable data sample replacement using only the collected radar data.

Replacing missing data between airborne SAR coherent image pairs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Musgrove, Cameron H.; West, James C.

For synthetic aperture radar systems, missing data samples can cause severe image distortion. When multiple, coherent data collections exist and the missing data samples do not overlap between collections, there exists the possibility of replacing data samples between collections. For airborne radar, the known and unknown motion of the aircraft prevents direct data sample replacement to repair image features. Finally, this paper presents a method to calculate the necessary phase corrections to enable data sample replacement using only the collected radar data.

Agents for replacement of NAD+/NADH system in enzymatic reactions

DOEpatents

Fish, Richard H.; Kerr, John B.; Lo, Christine H.

2004-04-06

Novel agents acting as co-factors for replacement of NAD(P).sup.+ /NAD(P)H co-enzyme systems in enzymatic oxido-reductive reactions. Agents mimicking the action of NAD(P).sup.+ /NAD(P)H system in enzymatic oxidation/reduction of substrates into reduced or oxidized products. A method for selection and preparation of the mimicking agents for replacement of NAD(P).sup.+ /NAD(P)H system and a device comprising co-factors for replacement of NAD(P).sup.+ /NAD(P)H system.

Thromboembolism in patients with pericardial valves in the absence of chronic anticoagulation: 12 years' experience.

PubMed

García-Bengoechea, J B; González-Juanatey, J R; Rubio, J; Durán, D; Sierra, J

1991-01-01

Between January 1977 and January 1989, 465 pericardial bioprostheses were implanted in 424 patients. The mean age of patients was 59.1 years (range 16-81 y.) At the time of surgery, 68% of the patients suffered from chronic atrial fibrillation. Mitral valve replacement was performed in 167 patients, aortic valve replacement in 216, multiple replacement in 40 (36 mitral and aortic, 3 mitral and tricuspid, and 1 mitral, aortic and tricuspid), and 1 pulmonary valve replacement. The different types of pericardial valve used were: Ionescu-Shiley 408, Mitral Medical 23, Bioflo 30, and Hancock 4. Hospital mortality was 10.1% with an attrition rate of 1.8 episodes per 100 patients/year. The 12-year actuarial survival rate was 65.1%. No patient underwent long-term anticoagulant treatment. The first 144 patients undergoing mitral and multiple valve replacements received temporary anticoagulation for the first 8 weeks after surgery. There was no valve thrombosis observed. Altogether 19 thromboembolic events (6 early and 13 late) were clinically documented. One patient died after an embolic event. The linearized rates of thromboembolism were 1.64 episodes per 100 patients/year for mitral and multiple valve replacements and 0.33 episodes per 100 patients/year for aortic valve replacement, with an overall rate of 1.0 episodes per 100 patients/year. Excluding early thromboembolism, the linearized rate was 1.02 episodes per 100 patients/year overall. The actuarial freedom from embolism was 92.4% overall, 88.2% for the mitral and multiple valve replacement group, and 97.6% for the aortic valve replacement group at a maximum follow-up of 12 years.(ABSTRACT TRUNCATED AT 250 WORDS)

Kinematics of a selectively constrained radiolucent anterior lumbar disc: comparisons to hybrid and circumferential fusion.

PubMed

Daftari, Tapan K; Chinthakunta, Suresh R; Ingalhalikar, Aditya; Gudipally, Manasa; Hussain, Mir; Khalil, Saif

2012-10-01

Despite encouraging clinical outcomes of one-level total disc replacements reported in literature, there is no compelling evidence regarding the stability following two-level disc replacement and hybrid constructs. The current study is aimed at evaluating the multidirectional kinematics of a two-level disc arthroplasty and hybrid construct with disc replacement adjacent to rigid circumferential fusion, compared to two-level fusion using a novel selectively constrained radiolucent anterior lumbar disc. Nine osteoligamentous lumbosacral spines (L1-S1) were tested in the following sequence: 1) Intact; 2) One-level disc replacement; 3) Hybrid; 4) Two-level disc replacement; and 5) Two-level fusion. Range of motion (at both implanted and adjacent level), and center of rotation in sagittal plane were recorded and calculated. At the level of implantation, motion was restored when one-level disc replacement was used but tended to decrease with two-level disc arthroplasty. The findings also revealed that both one-level and two-level disc replacement and hybrid constructs did not significantly change adjacent level kinematics compared to the intact condition, whereas the two-level fusion construct demonstrated a significant increase in flexibility at the adjacent level. The location of center of rotation in the sagittal plane at L4-L5 for the one-level disc replacement construct was similar to that of the intact condition. The one-level disc arthroplasty tended to mimic a motion profile similar to the intact spine. However, the two-level disc replacement construct tended to reduce motion and clinical stability of a two-level disc arthroplasty requires additional investigation. Hybrid constructs may be used as a surgical alternative for treating two-level lumbar degenerative disc disease. Published by Elsevier Ltd.

Catheter replacement structure in home medical care settings and regional characteristics in Tokyo and three adjoining prefectures.

PubMed

Kimura, Takuma; Yoshie, Satoru; Tsuchiya, Rumiko; Kawagoe, Shohei; Hirahara, Satoshi; Iijima, Katsuya; Akahoshi, Toru; Tsuji, Tetsuo

2017-04-01

The present study investigated the association between the structure of catheter replacement services in home medical care settings and regional characteristics. An anonymous self-administered questionnaire was carried out from August to September 2013. Participants were physicians from 5338 clinics that provided medical care services at home, and nurses from 1619 home-visit nursing stations in Tokyo and three adjoining prefectures. The questionnaire covered catheter replacement (gastrostomy tubes, nasogastric tubes, tracheal cannulas) during home medical care, and the professions of those who replaced urethral catheters for male and female patients. Regions were divided into two groups (higher- and lower-density regions) based on the number of clinics, number of home-visit nursing stations and the ratio of the population aged ≥65 years. The rates of respondents that reported catheter replacement was usually executed, and those who reported catheters were replaced by "physicians in principle" were compared between the groups. Responses were received from 842 clinics (16.3%) and 499 home-visit nursing stations (31.4%). In the higher-density regions, the rate of physicians who reported urethral catheters for male patients were replaced by "physicians in principle" was significantly higher than in the lower-density regions (P < 0.001). In the lower-density regions, the rate of nurses who reported urethral catheters for male patients were replaced by "nurses in principle" was significantly higher compared with the higher-density regions (P < 0.016). In home medical care settings, urethral catheters for male patients are replaced by nurses in regions where physician resources are limited. Geriatr Gerontol Int 2017; 17: 628-636. © 2016 Japan Geriatrics Society.

Pre-operative interventions (non-surgical and non-pharmacological) for patients with hip or knee osteoarthritis awaiting joint replacement surgery--a systematic review and meta-analysis.

PubMed

Wallis, Jason A; Taylor, Nicholas F

2011-12-01

To determine if pre-operative interventions for hip and knee osteoarthritis provide benefit before and after joint replacement. Systematic review with meta-analysis of randomised controlled trials (RCTs) of pre-operative interventions for people with hip or knee osteoarthritis awaiting joint replacement surgery. Standardised mean differences (SMD) were calculated for pain, musculoskeletal impairment, activity limitation, quality of life, and health service utilisation (length of stay and discharge destination). The GRADE approach was used to determine the quality of the evidence. Twenty-three RCTs involving 1461 participants awaiting hip or knee replacement surgery were identified. Meta-analysis provided moderate quality evidence that pre-operative exercise interventions for knee osteoarthritis reduced pain prior to knee replacement surgery (SMD (95% CI)=0.43 [0.13, 0.73]). None of the other meta-analyses investigating pre-operative interventions for knee osteoarthritis demonstrated any effect. Meta-analyses provided low to moderate quality evidence that exercise interventions for hip osteoarthritis reduced pain (SMD (95% CI)=0.52 [0.04, 1.01]) and improved activity (SMD (95% CI)=0.47 [0.11, 0.83]) prior to hip replacement surgery. Meta-analyses provided low quality evidence that exercise with education programs improved activity after hip replacement with reduced time to reach functional milestones during hospital stay (e.g., SMD (95% CI)=0.50 [0.10, 0.90] for first day walking). Low to moderate evidence from mostly small RCTs demonstrated that pre-operative interventions, particularly exercise, reduce pain for patients with hip and knee osteoarthritis prior to joint replacement, and exercise with education programs may improve activity after hip replacement. Copyright © 2011 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.

Complex patterns of tooth replacement revealed in the fruit bat (Eidolon helvum).

PubMed

Popa, Elena M; Anthwal, Neal; Tucker, Abigail S

2016-12-01

How teeth are replaced during normal growth and development has long been an important question for comparative and developmental anatomy. Non-standard model animals have become increasingly popular in this field due to the fact that the canonical model laboratory mammal, the mouse, develops only one generation of teeth (monophyodonty), whereas the majority of mammals possess two generations of teeth (diphyodonty). Here we used the straw-coloured fruit bat (Eidolon helvum), an Old World megabat, which has two generations of teeth, in order to observe the development and replacement of tooth germs from initiation up to mineralization stages. Our morphological study uses 3D reconstruction of histological sections to uncover differing arrangements of the first and second-generation tooth germs during the process of tooth replacement. We show that both tooth germ generations develop as part of the dental lamina, with the first generation detaching from the lamina, leaving the free edge to give rise to a second generation. This separation was particularly marked at the third premolar locus, where the primary and replacement teeth become positioned side by side, unconnected by a lamina. The position of the replacement tooth, with respect to the primary tooth, varied within the mouth, with replacements forming posterior to or directly lingual to the primary tooth. Development of replacement teeth was arrested at some tooth positions and this appeared to be linked to the timing of tooth initiation and the subsequent rate of development. This study adds an additional species to the growing body of non-model species used in the study of tooth replacement, and offers a new insight into the development of the diphyodont condition. © 2016 Anatomical Society.

Finite Element Study of a Lumbar Intervertebral Disc Nucleus Replacement Device.

PubMed

Coogan, Jessica S; Francis, W Loren; Eliason, Travis D; Bredbenner, Todd L; Stemper, Brian D; Yoganandan, Narayan; Pintar, Frank A; Nicolella, Daniel P

2016-01-01

Nucleus replacement technologies are a minimally invasive alternative to spinal fusion and total disc replacement that have the potential to reduce pain and restore motion for patients with degenerative disc disease. Finite element modeling can be used to determine the biomechanics associated with nucleus replacement technologies. The current study focuses on a new nucleus replacement device designed as a conforming silicone implant with an internal void. A validated finite element model of the human lumbar L3-L4 motion segment was developed and used to investigate the influence of the nucleus replacement device on spine biomechanics. In addition, the effect of device design changes on biomechanics was determined. A 3D, L3-L4 finite element model was constructed from medical imaging data. Models were created with the normal intact nucleus, the nucleus replacement device, and a solid silicone implant. Probabilistic analysis was performed on the normal model to provide quantitative validation metrics. Sensitivity analysis was performed on the silicone Shore A durometer of the device. Models were loaded under axial compression followed by flexion/extension, lateral bending, or axial rotation. Compressive displacement, endplate stresses, reaction moment, and annulus stresses were determined and compared between the different models. The novel nucleus replacement device resulted in similar compressive displacement, endplate stress, and annulus stress and slightly higher reaction moment compared with the normal nucleus. The solid implant resulted in decreased displacement, increased endplate stress, decreased annulus stress, and decreased reaction moment compared with the novel device. With increasing silicone durometer, compressive displacement decreased, endplate stress increased, reaction moment increased, and annulus stress decreased. Finite element analysis was used to show that the novel nucleus replacement device results in similar biomechanics compared with the normal intact nucleus.

Finite Element Study of a Lumbar Intervertebral Disc Nucleus Replacement Device

PubMed Central

Coogan, Jessica S.; Francis, W. Loren; Eliason, Travis D.; Bredbenner, Todd L.; Stemper, Brian D.; Yoganandan, Narayan; Pintar, Frank A.; Nicolella, Daniel P.

2016-01-01

Nucleus replacement technologies are a minimally invasive alternative to spinal fusion and total disc replacement that have the potential to reduce pain and restore motion for patients with degenerative disc disease. Finite element modeling can be used to determine the biomechanics associated with nucleus replacement technologies. The current study focuses on a new nucleus replacement device designed as a conforming silicone implant with an internal void. A validated finite element model of the human lumbar L3–L4 motion segment was developed and used to investigate the influence of the nucleus replacement device on spine biomechanics. In addition, the effect of device design changes on biomechanics was determined. A 3D, L3–L4 finite element model was constructed from medical imaging data. Models were created with the normal intact nucleus, the nucleus replacement device, and a solid silicone implant. Probabilistic analysis was performed on the normal model to provide quantitative validation metrics. Sensitivity analysis was performed on the silicone Shore A durometer of the device. Models were loaded under axial compression followed by flexion/extension, lateral bending, or axial rotation. Compressive displacement, endplate stresses, reaction moment, and annulus stresses were determined and compared between the different models. The novel nucleus replacement device resulted in similar compressive displacement, endplate stress, and annulus stress and slightly higher reaction moment compared with the normal nucleus. The solid implant resulted in decreased displacement, increased endplate stress, decreased annulus stress, and decreased reaction moment compared with the novel device. With increasing silicone durometer, compressive displacement decreased, endplate stress increased, reaction moment increased, and annulus stress decreased. Finite element analysis was used to show that the novel nucleus replacement device results in similar biomechanics compared with the normal intact nucleus. PMID:27990418

The effect of preheated tendon as a lean meat replacement on the properties of fine emulsion sausages.

PubMed

Sadler, D H; Young, O A

1993-01-01

Tendon from beef hind leg muscles was used to replace some of the lean in a conventional emulsion formulation. The tendon was homogenized and either used raw or preheated for 2·5 h at a range of temperatures (50, 60, 70, 80°C) before use. Texture analysis and sensory evaluation were performed on cylinders of cooked sausage. Texture analysis was carried out on formulations which had 20% of meat protein replaced by 20% tendons which were raw or had been preheated to 50, 60, 70, or 80°C. Fracturability decreased by about 40% with raw tendon, but was restored to within 20% of the no-replacement control if the tendon had been preheated. Hardness was approximately doubled by replacement with raw tendon or tendon heated at 50°C. At temperatures higher than that, hardness returned to approximately no-replacement levels. For sensory evaluation (0-25% replacement; preheating at 70°C), sausages were assessed by a 12-member panel for texture, flavour and overall acceptability. All attributes decreased with increasing collagen content, the decrease being less marked with preheated tendon. Thus more connective tissue could be added for the same panel score if the tissue was preheated. Comparison of the texture profile and the panel scores for texture at the same lean replacement level suggested that reduced fracturability was the texture parameter that panellists objected to when heated tendon replaced some of the lean. Other researchers have shown that connective tissue preheated to 100°C before addition in emulsion sausages results in improved yields and better sensory attributes, but the present results show that temperatures as low as 60°C can be effective for beef tendon. Copyright © 1993. Published by Elsevier Ltd.

Cell cycle- and chaperone-mediated regulation of H3K56ac incorporation in yeast.

PubMed

Kaplan, Tommy; Liu, Chih Long; Erkmann, Judith A; Holik, John; Grunstein, Michael; Kaufman, Paul D; Friedman, Nir; Rando, Oliver J

2008-11-01

Acetylation of histone H3 lysine 56 is a covalent modification best known as a mark of newly replicated chromatin, but it has also been linked to replication-independent histone replacement. Here, we measured H3K56ac levels at single-nucleosome resolution in asynchronously growing yeast cultures, as well as in yeast proceeding synchronously through the cell cycle. We developed a quantitative model of H3K56ac kinetics, which shows that H3K56ac is largely explained by the genomic replication timing and the turnover rate of each nucleosome, suggesting that cell cycle profiles of H3K56ac should reveal most first-time nucleosome incorporation events. However, since the deacetylases Hst3/4 prevent use of H3K56ac as a marker for histone deposition during M phase, we also directly measured M phase histone replacement rates. We report a global decrease in turnover rates during M phase and a further specific decrease in turnover at several early origins of replication, which switch from rapidly replaced in G1 phase to stably bound during M phase. Finally, by measuring H3 replacement in yeast deleted for the H3K56 acetyltransferase Rtt109 and its two co-chaperones Asf1 and Vps75, we find evidence that Rtt109 and Asf1 preferentially enhance histone replacement at rapidly replaced nucleosomes, whereas Vps75 appears to inhibit histone turnover at those loci. These results provide a broad perspective on histone replacement/incorporation throughout the cell cycle and suggest that H3K56 acetylation provides a positive-feedback loop by which replacement of a nucleosome enhances subsequent replacement at the same location.

Spontaneous transition of replacive to displacive growth of dolomite in burial dolomitization, and of serpentine in serpentinization

NASA Astrophysics Data System (ADS)

Merino, E.; Canals, A.

2011-12-01

Burial dolostones consist of huge volumes of dolomite that has replaced limestone volume for volume, with patches < 10 meters across of thin, equidistant "zebra" veins that are displacive. Characteristically, the contact between the two dolomite types is, under the microscope, seamless. This has long puzzled carbonate petrologists, who have mistaken the displacive dolomite veins for "void-filling cements" and therefore expect a sharp contact between the two dolomite types. The replacive dolomite forms not by dissolution-precipitation as usually assumed, but by dolomite-growth-driven pressure solution of the host calcite -- if the host is sufficiently viscous, or rigid. The local stress induced by the dolomite growth self-adjusts automatically so as to force the rates of dolomite growth and calcite pressure-solution to be mutually equal at each moment of the replacement. That is why replacement is always isovolumetric. But the dolomite-for-calcite replacement is self-accelerating via Ca2+ (each replacement increment releases Ca2+, which increases the activity product for dolomite and thus the rate of the next replacement increment, and so on), and crystalline carbonates are non-newtonian solids of the softening kind (as shown experimentally, Heard & Raleigh 1972). Thus, when the dolomite-for-calcite replacement becomes fast enough to reduce the local rock viscosity sufficiently, and if aqueous Mg2+ has not run out by then, the replacive growth will inevitably, and seamlessly, transition to displacive growth. This is when incipient zebra veins start to form. Each vein interacts with its neighbors via the induced stress they exert on each other, which leads to a "weeding" feedback that pressure dissolves some veins (the ones that find themselves too close to their neighbors), leaving the surviving ones more equidistant than before. Dolomitic zebra veins, or "rhythmites", are a good example of syntaxial veins. The same process and feedbacks, via Mg2+ instead of via Ca2+, take place in the serpentinization of ultrabasic rocks, leading also to displacive zebra veins of serpentine in seamless contact with the host, replacive serpentine. The origin of the dolomite zebra veins above turns out to have a serendipitous proof. The same feedback that causes the dolomite-for-calcite replacement to self-accelerate exponentially, raises the pore-fluid Ca2+ concentration also exponentially. Consequently, when the rheological replacement-to-displacement transition takes place, the displacive dolomite is growing under such a huge Ca2+ concentration that some Ca2+, even as submicroscopic calcitic slivers, is forced to substitute for Mg2+ in the structure of the growing dolomite, deforming and curving it. This is why the displacive zebra veins always consist of dolomite crystals that are curved, called saddle dolomite. It also explains why some calcite forms right after the dolomite veins stop growing, as a cement and/or back-replacing dolomite.

Influence of starter protein content on growth of dairy calves in an enhanced early nutrition program.

PubMed

Stamey, J A; Janovick, N A; Kertz, A F; Drackley, J K

2012-06-01

Our objectives were to determine the effect of starter crude protein (CP) content on growth of Holstein calves from birth to 10 wk of age in an enhanced early nutrition program, and to compare the enhanced program to a conventional milk replacer program. Calves (64 female, 25 male) were assigned to 3 treatments in a randomized block design: 1) conventional milk replacer (20% CP, 20% fat) plus conventional starter [19.6% CP, dry matter (DM) basis], 2) enhanced milk replacer (28.5% CP, 15% fat) plus conventional starter, and 3) enhanced milk replacer plus high-CP starter (25.5% CP, DM basis). Calves began treatments (n=29, 31, and 29 for treatments 1 to 3) at 3 d of age. Conventional milk replacer (12.5% solids) was fed at 1.25% of birth body weight (BW) as DM daily in 2 feedings from wk 1 to 5 and at 0.625% of birth BW once daily during wk 6. Enhanced milk replacer (15% solids) was fed at 1.5% of BW as DM during wk 1 and 2% of BW as DM during wk 2 to 5, divided into 2 daily feedings. During wk 6, enhanced milk replacer was fed at 1% of BW as DM once daily. Calves were weaned at d 42. Starter was available for ad libitum intake starting on d 3. Starter intake was greater for calves fed conventional milk replacer. For calves fed enhanced milk replacer, starter intake tended to be greater for calves fed enhanced starter. During the weaning period, enhanced starter promoted greater starter DM intake than the conventional starter. Over the 10-wk study, the average daily gain of BW (0.64, 0.74, and 0.80 kg/d) was greater for calves fed enhanced milk replacer with either starter and, for calves fed enhanced milk replacer, tended to be greater for calves fed high-CP starter. Rates of change in withers height, body length, and heart girth were greater for calves fed enhanced milk replacer but did not differ between starter CP concentrations. The postweaning BW for enhanced milk replacer treatments was greater for calves receiving the enhanced starter at wk 8 (73.7, 81.3, and 85.8 kg) and wk 10 (88.0, 94.9, and 99.9 kg). Starter CP content did not affect height, length, or heart girth within enhanced milk replacer treatments. Regression analysis showed that gain of BW during the first week postweaning (wk 7) increased with greater 3-d mean starter intake in the week before weaning. Starter with 25.5% CP (DM basis) provided modest benefits in starter intake (particularly around weaning) and growth for dairy calves in an enhanced early nutrition program compared with a conventional starter (19.6% CP). Copyright © 2012 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Medicare Program; Comprehensive Care for Joint Replacement Payment Model for Acute Care Hospitals Furnishing Lower Extremity Joint Replacement Services. Final rule.

PubMed

2015-11-24

This final rule implements a new Medicare Part A and B payment model under section 1115A of the Social Security Act, called the Comprehensive Care for Joint Replacement (CJR) model, in which acute care hospitals in certain selected geographic areas will receive retrospective bundled payments for episodes of care for lower extremity joint replacement (LEJR) or reattachment of a lower extremity. All related care within 90 days of hospital discharge from the joint replacement procedure will be included in the episode of care. We believe this model will further our goals in improving the efficiency and quality of care for Medicare beneficiaries with these common medical procedures.

Replacement predictions for drinking water networks through historical data.

PubMed

Malm, Annika; Ljunggren, Olle; Bergstedt, Olof; Pettersson, Thomas J R; Morrison, Gregory M

2012-05-01

Lifetime distribution functions and current network age data can be combined to provide an assessment of the future replacement needs for drinking water distribution networks. Reliable lifetime predictions are limited by a lack of understanding of deterioration processes for different pipe materials under varied conditions. An alternative approach is the use of real historical data for replacement over an extended time series. In this paper, future replacement needs are predicted through historical data representing more than one hundred years of drinking water pipe replacement in Gothenburg, Sweden. The verified data fits well with commonly used lifetime distribution curves. Predictions for the future are discussed in the context of path dependence theory. Copyright © 2012 Elsevier Ltd. All rights reserved.

38 CFR 21.220 - Replacement of supplies.

Code of Federal Regulations, 2010 CFR

2010-07-01

... (CONTINUED) VOCATIONAL REHABILITATION AND EDUCATION Vocational Rehabilitation and Employment Under 38 U.S.C... will replace articles which are necessary to further pursuit of the veteran's program and which are... advancement from the Vocational Rehabilitation Revolving Fund to a veteran to replace articles for which VA...

A COTS-Based Replacement Strategy for Aging Avionics Computers

DTIC Science & Technology

2001-12-01

Communication Control Unit. A COTS-Based Replacement Strategy for Aging Avionics Computers COTS Microprocessor Real Time Operating System New Native Code...Native Code Objec ts Native Code Thread Real - Time Operating System Legacy Function x Virtual Component Environment Context Switch Thunk Add-in Replace

40 CFR 74.48 - Transfer of allowances from the replacement of thermal energy-process sources. [Reserved

Code of Federal Regulations, 2012 CFR

2012-07-01

... replacement of thermal energy-process sources. [Reserved] 74.48 Section 74.48 Protection of Environment... and Transfer and End of Year Compliance § 74.48 Transfer of allowances from the replacement of thermal energy—process sources. [Reserved] ...

40 CFR 74.48 - Transfer of allowances from the replacement of thermal energy-process sources. [Reserved

Code of Federal Regulations, 2014 CFR

2014-07-01

... replacement of thermal energy-process sources. [Reserved] 74.48 Section 74.48 Protection of Environment... and Transfer and End of Year Compliance § 74.48 Transfer of allowances from the replacement of thermal energy—process sources. [Reserved] ...

40 CFR 74.48 - Transfer of allowances from the replacement of thermal energy-process sources. [Reserved

Code of Federal Regulations, 2011 CFR

2011-07-01

... replacement of thermal energy-process sources. [Reserved] 74.48 Section 74.48 Protection of Environment... and Transfer and End of Year Compliance § 74.48 Transfer of allowances from the replacement of thermal energy—process sources. [Reserved] ...

40 CFR 74.48 - Transfer of allowances from the replacement of thermal energy-process sources. [Reserved

Code of Federal Regulations, 2013 CFR

2013-07-01

... replacement of thermal energy-process sources. [Reserved] 74.48 Section 74.48 Protection of Environment... and Transfer and End of Year Compliance § 74.48 Transfer of allowances from the replacement of thermal energy—process sources. [Reserved] ...

42 CFR 419.66 - Transitional pass-through payments: Medical devices.

Code of Federal Regulations, 2010 CFR

2010-10-01

... replace human skin (for example, a biological skin replacement material or synthetic skin replacement... HUMAN SERVICES (CONTINUED) MEDICARE PROGRAM PROSPECTIVE PAYMENT SYSTEM FOR HOSPITAL OUTPATIENT... human tissue, and is surgically implanted or inserted whether or not it remains with the patient when...

42 CFR 419.66 - Transitional pass-through payments: Medical devices.

Code of Federal Regulations, 2011 CFR

2011-10-01

... replace human skin (for example, a biological skin replacement material or synthetic skin replacement... HUMAN SERVICES (CONTINUED) MEDICARE PROGRAM PROSPECTIVE PAYMENT SYSTEM FOR HOSPITAL OUTPATIENT... human tissue, and is surgically implanted or inserted whether or not it remains with the patient when...

Accelerated slab replacement using temporary precast panels and self-consolidating concrete.

DOT National Transportation Integrated Search

2016-06-06

Slab replacement is the main activity in any concrete pavement rehabilitation project. According to a survey of industry and FDOT, contractor productivity in slab replacements has been very low, ranging between 25 to 50 cu. yds. The low number of sla...

24 CFR 570.457 - Displacement, relocation, acquisition, and replacement of housing.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 24 Housing and Urban Development 3 2012-04-01 2012-04-01 false Displacement, relocation... DEVELOPMENT BLOCK GRANTS Urban Development Action Grants § 570.457 Displacement, relocation, acquisition, and replacement of housing. The displacement, relocation, acquisition, and replacement of housing requirements of...

24 CFR 570.457 - Displacement, relocation, acquisition, and replacement of housing.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 24 Housing and Urban Development 3 2013-04-01 2013-04-01 false Displacement, relocation... DEVELOPMENT BLOCK GRANTS Urban Development Action Grants § 570.457 Displacement, relocation, acquisition, and replacement of housing. The displacement, relocation, acquisition, and replacement of housing requirements of...

24 CFR 570.457 - Displacement, relocation, acquisition, and replacement of housing.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 24 Housing and Urban Development 3 2010-04-01 2010-04-01 false Displacement, relocation... DEVELOPMENT BLOCK GRANTS Urban Development Action Grants § 570.457 Displacement, relocation, acquisition, and replacement of housing. The displacement, relocation, acquisition, and replacement of housing requirements of...

24 CFR 570.457 - Displacement, relocation, acquisition, and replacement of housing.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 24 Housing and Urban Development 3 2014-04-01 2013-04-01 true Displacement, relocation... DEVELOPMENT BLOCK GRANTS Urban Development Action Grants § 570.457 Displacement, relocation, acquisition, and replacement of housing. The displacement, relocation, acquisition, and replacement of housing requirements of...

24 CFR 570.457 - Displacement, relocation, acquisition, and replacement of housing.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 24 Housing and Urban Development 3 2011-04-01 2010-04-01 true Displacement, relocation... DEVELOPMENT BLOCK GRANTS Urban Development Action Grants § 570.457 Displacement, relocation, acquisition, and replacement of housing. The displacement, relocation, acquisition, and replacement of housing requirements of...

77 FR 16430 - Airworthiness Directives; Airbus Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-21

... opposite the line replaceable unit racking. This AD requires replacing a certain aluminum high pressure... proposed to require replacing a certain aluminum high pressure pipe with a new corrosion resistant... comply with paragraph (1) of this [EASA] AD, unless, inadvertently, the high pressure pipe P/N...

40 CFR 1068.240 - What are the provisions for exempting new replacement engines?

Code of Federal Regulations, 2010 CFR

2010-07-01

... new replacement engines? 1068.240 Section 1068.240 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS GENERAL COMPLIANCE PROVISIONS FOR ENGINE PROGRAMS Exemptions and Exclusions § 1068.240 What are the provisions for exempting new replacement engines? The...

47 CFR 54.304 - Administration of Connect America Fund Intercarrier Compensation Replacement.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 47 Telecommunication 3 2013-10-01 2013-10-01 false Administration of Connect America Fund Intercarrier Compensation Replacement. 54.304 Section 54.304 Telecommunication FEDERAL COMMUNICATIONS... High Cost Areas § 54.304 Administration of Connect America Fund Intercarrier Compensation Replacement...

47 CFR 54.304 - Administration of Connect America Fund Intercarrier Compensation Replacement.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 47 Telecommunication 3 2014-10-01 2014-10-01 false Administration of Connect America Fund Intercarrier Compensation Replacement. 54.304 Section 54.304 Telecommunication FEDERAL COMMUNICATIONS... High Cost Areas § 54.304 Administration of Connect America Fund Intercarrier Compensation Replacement...

47 CFR 54.304 - Administration of Connect America Fund Intercarrier Compensation Replacement.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 47 Telecommunication 3 2012-10-01 2012-10-01 false Administration of Connect America Fund Intercarrier Compensation Replacement. 54.304 Section 54.304 Telecommunication FEDERAL COMMUNICATIONS... High Cost Areas § 54.304 Administration of Connect America Fund Intercarrier Compensation Replacement...

Regulation of VH Replacement by B Cell Receptor (BCR)-mediated Signaling in Human Immature B Cells

PubMed Central

Liu, Jing; Lange, Miles D.; Hong, Sang Yong; Xie, Wanqin; Xu, Kerui; Huang, Lin; Yu, Yangsheng; Ehrhardt, Götz R. A.; Zemlin, Michael; Burrows, Peter D.; Su, Kaihong; Carter, Robert H.; Zhang, Zhixin

2013-01-01

VH replacement provides a unique RAG-mediated recombination mechanism to edit non-functional IgH genes or IgH genes encoding self reactive B cell receptors (BCRs) and contributes to the diversification of antibody repertoire in mouse and human. Currently, it is not clear how VH replacement is regulated during early B lineage cell development. Here we show that crosslinking BCRs induces VH replacement in human EU12 μHC+ cells and in the newly emigrated immature B cells purified from peripheral blood of healthy donors or tonsillar samples. BCR signaling-induced VH replacement is dependent on the activation of Syk and Src kinases; but is inhibited by CD19 co-stimulation, presumably through activation of the PI3 kinase pathway. These results show for the first time that VH replacement is regulated by BCR-mediated signaling in human immature B cells, which can be modulated by physiological and pharmacological treatments. PMID:23630348

Effects of ovariectomy and estrogen replacement therapy on laryngeal tissue: a histopathological experimental animal study.

PubMed

Tatlipinar, Arzu; Günes, Pembegül; Ozbeyli, Dilek; Cimen, Burak; Gökçeer, Tanju

2011-12-01

To determine the histopathological effect of estrogen deficiency and hormone replacement treatment on laryngeal tissue in ovariectomized rats. Animal study. The study was conducted at the animal experiment laboratory of Marmara University School of Medicine, Istanbul, Turkey. Six-month-old female Wistar albino rats were divided into the following 3 groups (n = 8 per group): sham-operated control, ovariectomized, and ovariectomized with estrogen replacement. Rats in the ovariectomized with estrogen replacement group received 17 β-estradiol valerate (200 µg/kg, subcutaneously) once a week. Animals were killed after 8 weeks of intervention. Significant changes were observed in the ovariectomized group when edema in lamina propria, inflammation in squamous, respiratory epithelia and lamina propria, pseudostratification, and cilia loss were assessed. Except cilia loss, there were no significant differences in the assessments between the sham-operated control and ovariectomized with estrogen replacement groups. On the basis of histopathological evaluations, it was shown that estrogen replacement helped to improve laryngeal changes due to experimentally induced menopause.

Studies on Punching Shear Resistance of Two Way Slab Specimens with Partial Replacement of Cement by GGBS with Different Edge Conditions

NASA Astrophysics Data System (ADS)

Nemani, Ravi Dakshina Murthy; Rao, M. V. S.; Grandhe, Veera Venkata Satya Naranyana

2016-09-01

The present work is an effort to quantify the punching shear load resistance effect on two way simply supported slab specimens with replacement of cement by Ground Granulated Blast Furnace Slag (GGBS) with different edge conditions at various replacement levels and evaluate its efficiency. GGBS replacement has emerged as a major alternative to conventional concrete and has rapidly drawn the concrete industry attention due to its cement savings, cost savings, environmental and socio-economic benefits. The two way slab specimens were subjected to punching shear load by in house fabricated apparatus. The slab specimens were cast using M30 grade concrete with HYSD bars. The cement was partially replaced with GGBS at different percentages i.e., 0 to 30 % at regular intervals of 10 %. The test results indicate that the two way slab specimens with partial replacement of cement by GGBS exhibit high resistance against punching shear when compared with conventional concretes slab specimens.

High prevalence of iatrogenic hyperthyroidism in elderly patients with atrial fibrillation in an anticoagulation clinic.

PubMed

Krishnan, Sandeep Kumar; Dohrmann, Mary L; Brietzke, Stephen A; Fleming, David A; Flaker, Greg C

2011-01-01

In elderly patients with established atrial fibrillation (AF) who are receiving thyroid replacement, regular testing for thyroid function is often not performed, placing the patient at risk for iatrogenic hyperthyroidism. Of 215 patients followed in an anticoagulation clinic, 41 were receiving thyroid replacement and 15 of these were found to have hyperthyroidism. Eight had documented AF coincident with abnormal thyroid function. In addition, only 22 patients on thyroid replacement had an annual TSH. In conclusion, iatrogenic hyperthyroidism may frequently be missed in AF patients because of inadequate monitoring of serum TSH. Thyroid replacement is common in elderly patients with AF followed in an anticoagulation clinic. Laboratory evidence of hyperthyroidism occurred in 37%, usually in patients with higher doses of thyroid replacement, and often associated with AF. The frequency of iatrogenic hyperthyroidism may be underestimated in patients with AF since many patients who receive thyroid replacement therapy are not monitored regularly with serum TSH.

The replacement child. Variations on a theme in history and psychoanalysis.

PubMed

Anisfeld, L; Richards, A D

2000-01-01

This paper reviews the literature on the replacement child syndrome and examines its historical, theoretical, and biographical ramifications. Although a replacement child in a literal sense is one conceived to take the place of a deceased sibling, the concept may be extended to many other situations in which a child is put in the place of someone else in the family system. In his experience of survivor guilt for his deceased brother Julius, Freud may be regarded as such a metaphorical replacement child. The collective tragedy of the Holocaust gives the replacement child concept a special meaning, since the children born in its aftermath had to fill the void in the lives not only of individual parents but of the Jewish people as a whole. One of the coauthors of this paper, Leon Anisfeld, was born after World War II to parents who had lost previous spouses and children, and his personal experience as a replacement child informs the theoretical issues considered here.

Projecting the need for hip replacement over the next three decades: influence of changing demography and threshold for surgery

PubMed Central

Birrell, F.; Johnell, O.; Silman, A.

1999-01-01

OBJECTIVES—To estimate the requirement for total hip replacement in the United Kingdom over the next three decades
METHODS—Projection of age and sex specific hip replacements in the UK over 10 year intervals taking account of demographic change and the extrapolation of arthroplasty rates from Sweden; a country with recently introduced guidelines.
RESULTS—Assuming no change in the age and sex specific arthroplasty rates, the estimated number of hip replacements will increase by 40% over the next 30 year period because of demographic change alone. The proportionate change will be substantially higher in men (51%) than women (33%), with a doubling of the number of male hip replacements in those aged over 85. Changes in the threshold for surgery may increase this further—up to double the current number.
CONCLUSION—A sharp rise in hip replacements will be needed to satisfy needs in the UK population over the next 30 years.

 PMID:10460191

Sugar replacers: from technological challenges to consequences on health.

PubMed

Lê, Kim-Anne; Robin, Frédéric; Roger, Olivier

2016-07-01

Dietary sugars play a role in noncommunicable diseases and represent a clear target for reduction. In this context, product reformulation can have a positive impact on health. Several technological solutions are available to replace sugar, all with benefits and limitations. The goal of this review is to describe the main sugar replacement alternatives and discuss their impact on health and product physicochemical properties. Although high intensity sweeteners and polyols have been used for a long time to replace sucrose and despite no clear evidence of harm, the trend is today to look for alternatives such as sweet enhancers or alternative sugars such as allulose or tagatose, which are both low caloric. To replace the physical properties of sugars, new trends are to substitute widely used maltodextrins by dietary fibres to confer added health benefits. A wide range of solutions is currently available to replace dietary sugars and compensate for the impact on bulking properties and sweetness profile of food products.

Managing the replacement cycle of laser inventory.

PubMed

Davis, C E

1992-01-01

Medical lasers are quickly moving into the replacement phase of technology management. Barnes Hospital (St. Louis, MO) is using its laser team to define a process of planned laser replacement using the experience gained from traditional medical equipment replacement cycles, quality improvement principles and tools, and other formalized interdisciplinary teams. The process described in this paper has six basic steps: (1) A decision is made to request a replacement laser. (2) An appropriation request form is completed and submitted with the clinical and/or technical justifications. (3) Those requests initiated outside of the Clinical Engineering Department are reviewed by the Clinical Engineer/Medical Laser Safety Officer (CE/MLSO). (4) The CE/MLSO presents the requests to the hospital Laser Committee, and (5) then to the Laser Users' Group. (6) Finally, an Expenditure Authorization Committee reviews all capital expense requests, including those for replacement lasers, and allocates funds for the next fiscal year. This paper illustrates and evaluates the process, using an example from the review process for 1993 equipment purchases at Barnes Hospital.

The effect of patient age at intervention on risk of implant revision after total replacement of the hip or knee: a population-based cohort study.

PubMed

Bayliss, Lee E; Culliford, David; Monk, A Paul; Glyn-Jones, Sion; Prieto-Alhambra, Daniel; Judge, Andrew; Cooper, Cyrus; Carr, Andrew J; Arden, Nigel K; Beard, David J; Price, Andrew J

2017-04-08

Total joint replacements for end-stage osteoarthritis of the hip and knee are cost-effective and demonstrate significant clinical improvement. However, robust population based lifetime-risk data for implant revision are not available to aid patient decision making, which is a particular problem in young patient groups deciding on best-timing for surgery. We did implant survival analysis on all patients within the Clinical Practice Research Datalink who had undergone total hip replacement or total knee replacement. These data were adjusted for all-cause mortality with data from the Office for National Statistics and used to generate lifetime risks of revision surgery based on increasing age at the time of primary surgery. We identified 63 158 patients who had undergone total hip replacement and 54 276 who had total knee replacement between Jan 1, 1991, and Aug 10, 2011, and followed up these patients to a maximum of 20 years. For total hip replacement, 10-year implant survival rate was 95·6% (95% CI 95·3-95·9) and 20-year rate was 85·0% (83·2-86·6). For total knee replacement, 10-year implant survival rate was 96·1% (95·8-96·4), and 20-year implant survival rate was 89·7% (87·5-91·5). The lifetime risk of requiring revision surgery in patients who had total hip replacement or total knee replacement over the age of 70 years was about 5% with no difference between sexes. For those who had surgery younger than 70 years, however, the lifetime risk of revision increased for younger patients, up to 35% (95% CI 30·9-39·1) for men in their early 50s, with large differences seen between male and female patients (15% lower for women in same age group). The median time to revision for patients who had surgery younger than age 60 was 4·4 years. Our study used novel methodology to investigate and offer new insight into the importance of young age and risk of revision after total hip or knee replacement. Our evidence challenges the increasing trend for more total hip replacements and total knee replacements to be done in the younger patient group, and these data should be offered to patients as part of the shared decision making process. Oxford Musculoskeletal Biomedical Research Unit, National Institute for Health Research. Copyright © 2017 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY license. Published by Elsevier Ltd.. All rights reserved.

Effects of additional milk replacer feeding on calf health, growth, and selected blood metabolites in calves.

PubMed

Quigley, J D; Wolfe, T A; Elsasser, T H

2006-01-01

The objective of the experiment was to evaluate effects of increased milk replacer feeding on growth, intake, feed efficiency, and health parameters in stressed calves. Holstein bull calves (n = 120; approximately 3 to 8 d of age) were purchased from sale barns and dairy farms and housed in fiberglass hutches. In addition, wood shavings contaminated with coronavirus were mixed with clean shavings and added to each hutch before the start of the experiment. Calves were fed either a fixed amount (454 g/d) of a 20% crude protein (CP), 20% fat milk replacer to weaning at 28 d or a variable amount (454, 681, 908, and 454 g/d on d 0 to 7, 8 to 14, 15 to 31, and 32 to 41, respectively) of a milk replacer containing 28% CP and 17% fat without or with added dietary supplement containing bovine serum. Calves were also fed commercial calf starter and water ad libitum. Plasma IgG concentration in most calves on arrival at the facility was < 10 g/L. Intake, change in body weight, feed efficiency, morbidity and mortality, and selected plasma metabolites were determined. Body weight at 28 d, 56 d, daily body weight gain, intake of milk replacer, fecal scores, days with diarrhea, and days treated with antibiotics were increased with feeding variable amount of milk replacer over the 56-d study. Starter intake from d 1 to 56 was reduced from 919 to 717 g/d in calves fed fixed and variable amounts of milk replacer, respectively. Morbidity, measured as the number of days that calves had diarrhea, was increased by 53% when a variable amount of milk replacer was fed. Calves fed variable milk replacer were treated with antibiotics for 3.1 d compared with 1.9 d for calves fed 454 g of milk replacer/d. Concentrations of plasma glucose, urea N, and insulin-like growth factor-I were increased when calves were fed variable amount of milk replacer. Dietary supplement containing bovine serum had no effect on any parameter measured. There was no effect of milk replacer feeding on concentrations of nonesterified fatty acids, total protein, or growth hormone concentrations. Plasma tumor necrosis factor-alpha was highest in calves with the highest plasma IgG concentrations on the day of arrival and might be related to the calf's ability to identify pathogens in the environment. Under conditions of this study, calves fed variable amount of milk replacer and exposed to immunological challenge before weaning had greater BW gain, but also increased incidence of diarrhea that required added veterinary treatments.

Meat consumption and risk of primary hip and knee joint replacement due to osteoarthritis: a prospective cohort study

PubMed Central

2011-01-01

Background There is emerging evidence for a beneficial effect of meat consumption on the musculoskeletal system. However, whether it affects the risk of knee and hip osteoarthritis is unknown. We performed a prospective cohort study to examine the relationship between meat consumption and risk of primary hip and knee replacement for osteoarthritis. Methods Eligible 35,331 participants were selected from the Melbourne Collaborative Cohort Study recruited during 1990-1994. Consumption of fresh red meat, processed meat, chicken, and fish was assessed using a food frequency questionnaire. Primary hip and knee replacement for osteoarthritis during 2001-2005 was determined by linking the cohort records to the Australian National Joint Replacement Registry. Results There was a negative dose-response relationship between fresh red meat consumption and the risk of hip replacement (hazard ratio (HR) 0.94 per increase in intake of one time/week, 95% confidence interval (CI) 0.89-0.98). In contrast, there was no association with knee replacement risk (HR 0.98, 95% CI 0.94-1.02). Consumption of processed meat, chicken and fish were not associated with risk of hip or knee replacement. Conclusion A high level consumption of fresh red meat was associated with a decreased risk of hip, but not knee, joint replacement for osteoarthritis. One possible mechanism to explain these differential associations may be via an effect of meat intake on bone strength and hip shape. Further confirmatory studies are warranted. PMID:21235820

Meat consumption and risk of primary hip and knee joint replacement due to osteoarthritis: a prospective cohort study.

PubMed

Wang, Yuanyuan; Simpson, Julie Anne; Wluka, Anita E; English, Dallas R; Giles, Graham G; Graves, Stephen; Cicuttini, Flavia M

2011-01-16

There is emerging evidence for a beneficial effect of meat consumption on the musculoskeletal system. However, whether it affects the risk of knee and hip osteoarthritis is unknown. We performed a prospective cohort study to examine the relationship between meat consumption and risk of primary hip and knee replacement for osteoarthritis. Eligible 35,331 participants were selected from the Melbourne Collaborative Cohort Study recruited during 1990-1994. Consumption of fresh red meat, processed meat, chicken, and fish was assessed using a food frequency questionnaire. Primary hip and knee replacement for osteoarthritis during 2001-2005 was determined by linking the cohort records to the Australian National Joint Replacement Registry. There was a negative dose-response relationship between fresh red meat consumption and the risk of hip replacement (hazard ratio (HR) 0.94 per increase in intake of one time/week, 95% confidence interval (CI) 0.89-0.98). In contrast, there was no association with knee replacement risk (HR 0.98, 95% CI 0.94-1.02). Consumption of processed meat, chicken and fish were not associated with risk of hip or knee replacement. A high level consumption of fresh red meat was associated with a decreased risk of hip, but not knee, joint replacement for osteoarthritis. One possible mechanism to explain these differential associations may be via an effect of meat intake on bone strength and hip shape. Further confirmatory studies are warranted.

Total Arch versus Hemiarch Replacement for Type A Acute Aortic Dissection: A Single-Center Experience.

PubMed

Lio, Antonio; Nicolò, Francesca; Bovio, Emanuele; Serrao, Andrea; Zeitani, Jacob; Scafuri, Antonio; Chiariello, Luigi; Ruvolo, Giovanni

2016-12-01

We retrospectively evaluated early and intermediate outcomes of aortic arch surgery in patients with type A acute aortic dissection (AAD), investigating the effect of arch surgery extension on postoperative results. From January 2006 through July 2013, 201 patients with type A AAD underwent urgent corrective surgery at our institution. Of the 92 patients chosen for this study, 59 underwent hemiarch replacement (hemiarch group), and 33 underwent total arch replacement (total arch group) in conjunction with ascending aorta replacement. The operative mortality rate was 22%. Total arch replacement was associated with a 33% risk of operative death, versus 15% for hemiarch ( P =0.044). Multivariable analysis found these independent predictors of operative death: age (odds ratio [OR]=1.13/yr; 95% confidence interval [CI], 1.04-1.23; P =0.002), body mass index >30 kg/m 2 (OR=9.9; 95% CI, 1.28-19; P =0.028), postoperative low cardiac output (OR=10.6; 95% CI, 1.18-25; P =0.035), and total arch replacement (OR=8.8; 95% CI, 1.39-15; P =0.021) The mean overall 5-year survival rate was 59.3% ± 5.5%, and mean 5-year freedom from distal reintervention was 95.4% ± 3.2% ( P =NS). In type A AAD, aortic arch surgery is still associated with high operative mortality rates; hemiarch replacement can be performed more safely than total arch replacement. Rates of distal aortic reoperation were not different between the 2 surgical strategies.

Potential of Silanes for Chromate Replacement in Metal Finishing Industries

DTIC Science & Technology

2002-09-16

POTENTIAL OF SILANES FOR CHROMATE REPLACEMENT IN METAL FINISHING INDUSTRIES Wim J. van Ooij*, Danqing Zhu, Vignesh Palanivel, J. Anna Lamar...18 2 POTENTIAL OF SILANES FOR CHROMATE REPLACEMENT IN METAL FINISHING INDUSTRIES Wim J. van Ooij, Danqing Zhu, Vignesh Palanivel, J. Anna Lamar

75 FR 49482 - Privacy Act of 1974; System of Records

Federal Register 2010, 2011, 2012, 2013, 2014

2010-08-13

... replace with ``Incident Report Records.'' System location: Delete entry and replace with ``Command Support... may be accessed only by the Commander, Deputy Commander, Chief, Command Support Division, or other... and replace with ``Command Support Division, EU1, Defense Information Systems Agency-Europe, APO AE...

49 CFR 172.338 - Replacement of identification numbers.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 49 Transportation 2 2013-10-01 2013-10-01 false Replacement of identification numbers. 172.338..., TRAINING REQUIREMENTS, AND SECURITY PLANS Marking § 172.338 Replacement of identification numbers. If more than one of the identification number markings on placards, orange panels, or white square-on-point...

49 CFR 172.338 - Replacement of identification numbers.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 2 2010-10-01 2010-10-01 false Replacement of identification numbers. 172.338..., TRAINING REQUIREMENTS, AND SECURITY PLANS Marking § 172.338 Replacement of identification numbers. If more than one of the identification number markings on placards, orange panels, or white square-on-point...

49 CFR 172.338 - Replacement of identification numbers.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 2 2011-10-01 2011-10-01 false Replacement of identification numbers. 172.338..., TRAINING REQUIREMENTS, AND SECURITY PLANS Marking § 172.338 Replacement of identification numbers. If more than one of the identification number markings on placards, orange panels, or white square-on-point...

14 CFR 45.15 - Replacement and modification parts.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Replacement and modification parts. 45.15 Section 45.15 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT IDENTIFICATION AND REGISTRATION MARKING Identification of Aircraft and Related Products § 45.15 Replacement and...

14 CFR 45.15 - Replacement and modification parts.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Replacement and modification parts. 45.15 Section 45.15 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT IDENTIFICATION AND REGISTRATION MARKING Marking of Products and Articles § 45.15 Replacement and modification...

Amino acid supplementation of calf milk replacers containing plasma protein.

PubMed

Morrison, S Y; Campbell, J M; Drackley, J K

2017-06-01

We determined the effects of calf milk replacers containing 0, 5, or 10% bovine plasma protein (PP), either without or with the supplemental amino acids (AA) Ile and Thr, on growth and health of male Holstein calves (n = 104) for 56 d. Milk replacers were formulated to contain 22% crude protein (CP), 20% fat, and 2.0% Lys. Milk replacers (12.5% solids) were fed at a rate of 1.5% of body weight (BW) on a dry matter basis during wk 1 and 1.75% of BW beginning on d 8. Starter was introduced on d 36 so that effects of PP and AA balance in milk replacers could be isolated. Intake, respiratory scores, and fecal scores were measured daily. Body weight and stature were measured weekly and blood serum samples were obtained during wk 4. Treatments had no effects on intakes of dry matter, CP, or metabolizable energy. During wk 6 and 8, BW was less as PP inclusion increased without AA supplementation compared with the other treatments. In wk 7, calves fed the higher level of PP without AA had lower BW than calves fed either the lower level of PP without supplemented AA or the higher inclusion of PP with supplemented AA. Average daily gain and gain:feed were lowest for calves fed the higher inclusion of PP without supplemented AA; heart girth in wk 7 was smallest for those calves. During the first 21 d, occurrence of scours was greater in calves fed the control milk replacer than in calves fed milk replacers containing the higher inclusion of PP either without or with supplemental AA. Occurrence of scours was also greater for the lower inclusion of PP compared with the higher inclusion of PP when AA were supplemented. Throughout the 56-d experiment, the chance of antibiotic treatment was greater for calves fed the control milk replacer than for all other treatments except the higher inclusion of PP without supplemental AA. Additionally, chance of antibiotic treatment was greater for the higher inclusion of PP without supplemental AA than for other milk replacers with PP. Calves fed treatments with the higher inclusion of PP had fewer days of scours than the controls. All milk replacers with PP, except the milk replacer containing higher PP without supplemental AA, had fewer days of treatment with antibiotics compared to the all-milk control. Inclusion of PP provided similar performance and improved health as long as milk replacers were balanced for Ile and Thr. Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

30 CFR 823.14 - Soil replacement.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 30 Mineral Resources 3 2013-07-01 2013-07-01 false Soil replacement. 823.14 Section 823.14 Mineral... Soil replacement. (a) Soil reconstruction specifications established by the U.S. Soil Conservation Service shall be based upon the standards of the National Cooperative Soil Survey and shall include, as a...

30 CFR 823.14 - Soil replacement.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Soil replacement. 823.14 Section 823.14 Mineral... Soil replacement. (a) Soil reconstruction specifications established by the U.S. Soil Conservation Service shall be based upon the standards of the National Cooperative Soil Survey and shall include, as a...

30 CFR 823.14 - Soil replacement.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 30 Mineral Resources 3 2014-07-01 2014-07-01 false Soil replacement. 823.14 Section 823.14 Mineral... Soil replacement. (a) Soil reconstruction specifications established by the U.S. Soil Conservation Service shall be based upon the standards of the National Cooperative Soil Survey and shall include, as a...

30 CFR 823.14 - Soil replacement.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 30 Mineral Resources 3 2012-07-01 2012-07-01 false Soil replacement. 823.14 Section 823.14 Mineral... Soil replacement. (a) Soil reconstruction specifications established by the U.S. Soil Conservation Service shall be based upon the standards of the National Cooperative Soil Survey and shall include, as a...

30 CFR 823.14 - Soil replacement.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 3 2011-07-01 2011-07-01 false Soil replacement. 823.14 Section 823.14 Mineral... Soil replacement. (a) Soil reconstruction specifications established by the U.S. Soil Conservation Service shall be based upon the standards of the National Cooperative Soil Survey and shall include, as a...

19 CFR 148.37 - Replacement of unsatisfactory articles acquired abroad.

Code of Federal Regulations, 2010 CFR

2010-04-01

... customs matters and was without willful intent to avoid CBP supervision. (b) Procedure for replacement... 19 Customs Duties 2 2010-04-01 2010-04-01 false Replacement of unsatisfactory articles acquired abroad. 148.37 Section 148.37 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND...

19 CFR 148.37 - Replacement of unsatisfactory articles acquired abroad.

Code of Federal Regulations, 2013 CFR

2013-04-01

... customs matters and was without willful intent to avoid CBP supervision. (b) Procedure for replacement... 19 Customs Duties 2 2013-04-01 2013-04-01 false Replacement of unsatisfactory articles acquired abroad. 148.37 Section 148.37 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND...

19 CFR 148.37 - Replacement of unsatisfactory articles acquired abroad.

Code of Federal Regulations, 2014 CFR

2014-04-01

... customs matters and was without willful intent to avoid CBP supervision. (b) Procedure for replacement... 19 Customs Duties 2 2014-04-01 2014-04-01 false Replacement of unsatisfactory articles acquired abroad. 148.37 Section 148.37 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND...

19 CFR 148.37 - Replacement of unsatisfactory articles acquired abroad.

Code of Federal Regulations, 2011 CFR

2011-04-01

... customs matters and was without willful intent to avoid CBP supervision. (b) Procedure for replacement... 19 Customs Duties 2 2011-04-01 2011-04-01 false Replacement of unsatisfactory articles acquired abroad. 148.37 Section 148.37 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND...

19 CFR 148.37 - Replacement of unsatisfactory articles acquired abroad.

Code of Federal Regulations, 2012 CFR

2012-04-01

... customs matters and was without willful intent to avoid CBP supervision. (b) Procedure for replacement... 19 Customs Duties 2 2012-04-01 2012-04-01 false Replacement of unsatisfactory articles acquired abroad. 148.37 Section 148.37 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND...

Mercury Thermometer Replacements in Chemistry Laboratories

ERIC Educational Resources Information Center

Foster, Barbara L.

2005-01-01

The consequences of broken mercury-in-glass thermometers in academic laboratories results in various health and environmental hazards, which needs to be replaced, by long-stem digital thermometers and non-mercury glass thermometers. The factors that should be considered during the mercury replacement process are types of applications in the…

Wildland fire effects in silviculturally treated vs. untreated stands of New Mexico and Arizona

Treesearch

Douglas S. Cram; Terrell T. Baker; Jon C. Boren

2006-01-01

Stand-replacement fires, particularly in ponderosa pine (Pinus ponderosa) forests, have replaced highfrequency, low-intensity historical fire regimes. We examined whether forest stands treated recently using silvicultural practices would be (1) less susceptible to stand-replacing crownfires, and (2) more ecologically and functionally resilient...

10 CFR 490.8 - Replacement fuel production goal.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 10 Energy 3 2014-01-01 2014-01-01 false Replacement fuel production goal. 490.8 Section 490.8 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ALTERNATIVE FUEL TRANSPORTATION PROGRAM General... sufficient to replace, on an energy equivalent basis, at least 30 percent of motor fuel consumption in the...

10 CFR 490.8 - Replacement fuel production goal.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 10 Energy 3 2013-01-01 2013-01-01 false Replacement fuel production goal. 490.8 Section 490.8 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ALTERNATIVE FUEL TRANSPORTATION PROGRAM General... sufficient to replace, on an energy equivalent basis, at least 30 percent of motor fuel consumption in the...

10 CFR 490.8 - Replacement fuel production goal.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 10 Energy 3 2010-01-01 2010-01-01 false Replacement fuel production goal. 490.8 Section 490.8 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ALTERNATIVE FUEL TRANSPORTATION PROGRAM General... sufficient to replace, on an energy equivalent basis, at least 30 percent of motor fuel consumption in the...

10 CFR 490.8 - Replacement fuel production goal.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 10 Energy 3 2011-01-01 2011-01-01 false Replacement fuel production goal. 490.8 Section 490.8 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ALTERNATIVE FUEL TRANSPORTATION PROGRAM General... sufficient to replace, on an energy equivalent basis, at least 30 percent of motor fuel consumption in the...

10 CFR 490.8 - Replacement fuel production goal.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 10 Energy 3 2012-01-01 2012-01-01 false Replacement fuel production goal. 490.8 Section 490.8 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ALTERNATIVE FUEL TRANSPORTATION PROGRAM General... sufficient to replace, on an energy equivalent basis, at least 30 percent of motor fuel consumption in the...

48 CFR 908.7101-4 - Replacement of motor vehicles.

Code of Federal Regulations, 2012 CFR

2012-10-01

... vehicles. 908.7101-4 Section 908.7101-4 Federal Acquisition Regulations System DEPARTMENT OF ENERGY....7101-4 Replacement of motor vehicles. (a) The replacement of motor vehicles shall be in accordance with... Heads of Contracting Activities may arrange to sell, as exchange sales, used motor vehicles being...

Functionality of Inulin as a Sucrose Replacer in Cookie Baking

USDA-ARS?s Scientific Manuscript database

Inulin was evaluated as a sucrose replacer for healthy cookie production with benefits of low glycemic impact and prebiotic soluble fiber. Sucrose (as a reference) and three inulin products of different concentrations (as soluble fibers) were used to explore the effects of sugar-replacer type on so...

Knee Replacement - Multiple Languages

MedlinePlus

... in a new window. Arabic (العربية) Expand Section Total Knee Replacement - العربية (Arabic) Bilingual PDF Health Information Translations Chinese, Simplified (Mandarin dialect) (简体中文) Expand Section Total Knee Replacement - 简体中文 (Chinese, Simplified (Mandarin dialect)) Bilingual PDF Health ...

77 FR 59391 - Transcontinental Gas Pipe Line Company, LLC; Notice of Intent To Prepare an Environmental...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-09-27

... Proposed Brandywine Creek Replacement Project; Request for Comments on Environmental Issues; and Notice of... Transcontinental Gas Pipe Line Company, LLC's (Transco) proposed Brandywine Creek Replacement Project (Project... participation section of this notice. FERC Public Scoping Meeting, Brandywine Creek Replacement Project, October...

Influence of Bicompartmental Knee Replacement on Stand-to-Sit Movement

ERIC Educational Resources Information Center

Wang, He; Frame, Jeff; Rolston, Lindsey

2012-01-01

Knee osteoarthritis often occurs in medial and patellofemoral compartments. A bicompartmental knee replacement system replaces these two affected knee compartments and keeps the lateral compartment and cruciate ligaments intact. It is yet to be determined whether limbs with bicompartmental knee systems can demonstrate frontal-plane knee mechanics…

78 FR 38769 - Self-Regulatory Organizations; NYSE MKT LLC; Notice of Filing and Immediate Effectiveness of...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-06-27

... Replacing References to ``Principle Executive'' With References to ``Principal Executive'' in the Exchange's... Rule Change The Exchange proposes to replace references to ``principle executive'' with references to... replace references to ``principle executive'' with references to ``principal executive'' in the Exchange's...

41 CFR 102-34.255 - What are motor vehicle replacement standards?

Code of Federal Regulations, 2011 CFR

2011-01-01

... 41 Public Contracts and Property Management 3 2011-01-01 2011-01-01 false What are motor vehicle... Management Regulations System (Continued) FEDERAL MANAGEMENT REGULATION PERSONAL PROPERTY 34-MOTOR VEHICLE MANAGEMENT Replacement of Motor Vehicles § 102-34.255 What are motor vehicle replacement standards? Motor...

22 CFR 51.54 - Replacement passports without payment of applicable fees.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 22 Foreign Relations 1 2014-04-01 2014-04-01 false Replacement passports without payment of applicable fees. 51.54 Section 51.54 Foreign Relations DEPARTMENT OF STATE NATIONALITY AND PASSPORTS PASSPORTS Fees § 51.54 Replacement passports without payment of applicable fees. A passport issuing office...

22 CFR 51.54 - Replacement passports without payment of applicable fees.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 22 Foreign Relations 1 2011-04-01 2011-04-01 false Replacement passports without payment of applicable fees. 51.54 Section 51.54 Foreign Relations DEPARTMENT OF STATE NATIONALITY AND PASSPORTS PASSPORTS Fees § 51.54 Replacement passports without payment of applicable fees. A passport issuing office...

22 CFR 51.54 - Replacement passports without payment of applicable fees.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 22 Foreign Relations 1 2012-04-01 2012-04-01 false Replacement passports without payment of applicable fees. 51.54 Section 51.54 Foreign Relations DEPARTMENT OF STATE NATIONALITY AND PASSPORTS PASSPORTS Fees § 51.54 Replacement passports without payment of applicable fees. A passport issuing office...

22 CFR 51.54 - Replacement passports without payment of applicable fees.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Replacement passports without payment of applicable fees. 51.54 Section 51.54 Foreign Relations DEPARTMENT OF STATE NATIONALITY AND PASSPORTS PASSPORTS Fees § 51.54 Replacement passports without payment of applicable fees. A passport issuing office...

22 CFR 51.54 - Replacement passports without payment of applicable fees.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 22 Foreign Relations 1 2013-04-01 2013-04-01 false Replacement passports without payment of applicable fees. 51.54 Section 51.54 Foreign Relations DEPARTMENT OF STATE NATIONALITY AND PASSPORTS PASSPORTS Fees § 51.54 Replacement passports without payment of applicable fees. A passport issuing office...

75 FR 67711 - Extension of Scoping Period for the Supplemental Environmental Impact Statement for the Nuclear...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-11-03

... Statement for the Nuclear Facility Portion of the Chemistry and Metallurgy Research Building Replacement... Statement for the Nuclear Facility Portion of the Chemistry and Metallurgy Research Building Replacement... facility portion of the Chemistry and Metallurgy Research Building Replacement Project (CMRR-NF) at Los...

Flywheel energy storage system focus of display

Science.gov Websites

replacement for batteries For more information contact: e:mail: Public Affairs Golden, Colo., March 20, 1997 environmentally-friendly, advanced electricity storage technology that can replace lead acid batteries. A flywheel technologies for replacing conventional lead acid batteries as energy storage systems for a variety of

Script Reforms--Are They Necessary?

ERIC Educational Resources Information Center

James, Gregory

Script reform, the modification of an existing writing system, is often confused with script replacement of one writing system with another. Turkish underwent the replacement of Arabic script by an adaptation of Roman script under Kamel Ataturk, but a similar replacement in Persian was rejected because of the high rate of existing literacy in…

41 CFR 101-30.701-4 - Standardization relationship.

Code of Federal Regulations, 2011 CFR

2011-07-01

... relationship. 101-30.701-4 Section 101-30.701-4 Public Contracts and Property Management Federal Property... CATALOG SYSTEM 30.7-Item Reduction Program § 101-30.701-4 Standardization relationship. Standardization relationship means the relationship between the replaced item and the replacement item. The replaced item will...

24 CFR 891.855 - Replacement reserves.

Code of Federal Regulations, 2010 CFR

2010-04-01

... Partnerships and Mixed-Finance Development for Supportive Housing for the Elderly or Persons with Disabilities § 891.855 Replacement reserves. (a) The mixed-finance owner shall establish and maintain a replacement... requirements of 24 CFR 891.405. (b) The mixed-finance owner may obtain a disbursement from the reserve only if...

76 FR 79558 - Airworthiness Directives; Airbus Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2011-12-22

... racking. This proposed AD would require replacing a certain aluminum high pressure pipe with a new... this [EASA] AD, unless, inadvertently, the high pressure pipe P/N A5231007000600 has been replaced in... effective date of this AD, whichever occurs first, replace the aluminum high pressure pipe having part...

23 CFR 650.407 - Application for bridge replacement or rehabilitation.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 23 Highways 1 2012-04-01 2012-04-01 false Application for bridge replacement or rehabilitation... Rehabilitation Program § 650.407 Application for bridge replacement or rehabilitation. (a) Agencies participate... agency for review and processing. The State is responsible for submitting the six computer card format or...

23 CFR 650.407 - Application for bridge replacement or rehabilitation.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 23 Highways 1 2013-04-01 2013-04-01 false Application for bridge replacement or rehabilitation... Rehabilitation Program § 650.407 Application for bridge replacement or rehabilitation. (a) Agencies participate... agency for review and processing. The State is responsible for submitting the six computer card format or...

23 CFR 650.407 - Application for bridge replacement or rehabilitation.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 23 Highways 1 2014-04-01 2014-04-01 false Application for bridge replacement or rehabilitation... Rehabilitation Program § 650.407 Application for bridge replacement or rehabilitation. (a) Agencies participate... agency for review and processing. The State is responsible for submitting the six computer card format or...

40 CFR 141.84 - Lead service line replacement requirements.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 24 2013-07-01 2013-07-01 false Lead service line replacement... PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Control of Lead and Copper § 141.84 Lead service line replacement requirements. (a) Systems that fail to meet the lead action level in tap samples...

40 CFR 141.84 - Lead service line replacement requirements.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 24 2012-07-01 2012-07-01 false Lead service line replacement... PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Control of Lead and Copper § 141.84 Lead service line replacement requirements. (a) Systems that fail to meet the lead action level in tap samples...

40 CFR 141.84 - Lead service line replacement requirements.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 23 2014-07-01 2014-07-01 false Lead service line replacement... PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Control of Lead and Copper § 141.84 Lead service line replacement requirements. (a) Systems that fail to meet the lead action level in tap samples...

41 CFR 101-30.701-4 - Standardization relationship.

Code of Federal Regulations, 2010 CFR

2010-07-01

... relationship. 101-30.701-4 Section 101-30.701-4 Public Contracts and Property Management Federal Property... CATALOG SYSTEM 30.7-Item Reduction Program § 101-30.701-4 Standardization relationship. Standardization relationship means the relationship between the replaced item and the replacement item. The replaced item will...

10 CFR 34.27 - Leak testing and replacement of sealed sources.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 10 Energy 1 2014-01-01 2014-01-01 false Leak testing and replacement of sealed sources. 34.27 Section 34.27 Energy NUCLEAR REGULATORY COMMISSION LICENSES FOR INDUSTRIAL RADIOGRAPHY AND RADIATION SAFETY REQUIREMENTS FOR INDUSTRIAL RADIOGRAPHIC OPERATIONS Equipment § 34.27 Leak testing and replacement...

10 CFR 34.27 - Leak testing and replacement of sealed sources.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 10 Energy 1 2011-01-01 2011-01-01 false Leak testing and replacement of sealed sources. 34.27 Section 34.27 Energy NUCLEAR REGULATORY COMMISSION LICENSES FOR INDUSTRIAL RADIOGRAPHY AND RADIATION SAFETY REQUIREMENTS FOR INDUSTRIAL RADIOGRAPHIC OPERATIONS Equipment § 34.27 Leak testing and replacement...