Central Indentation Research Articles

An animal study to evaluate the safety and efficacy of a novel superelastic sizing device

Aim: Atrial septal defect measurement can be performed by stretching balloon diameter, two- and 3-dimensional transesophageal echocardiography (TEE). We evaluated a new superelastic sizing device (SSD) for deliniation of atrial septal defect margins and exact measurement without changing anatomy of the defect. Material and Methods: An artificial ASD was created in 8 swines and defect sizing was done by TEE and SSSD in fluoroscopy and autopsy. Correlation analysis was done between 3 methods in defect size measurement. Any adverse events, such as mortality or heart perforation were assessed. Results: There was a cardiac tamponade case in one animal because of the limited animal experience of the operator. Thrombus formation was observed in some animals due to prolongation of procedure time and low heparin dosage. SSD and TEE correlation (r=0.97, p<0.0001); TEE and autopsy correlation (r=0.973, p<0.0001); SSD and autopsy correlation (r=0.993; p<0.0001) all were statistically significant. Conclusion: In our animal study superelastic sizing device precisely delineated atrial septal defect margins on TEE and fluoroscopy. SSD measurements showed good correlation with TEE and autopsy measurements. The right and left portions of the device were well formed and central indentation allowed exact sizing of the atrial septal defect margins.

The skeletal phenotype of intermediate GM1 gangliosidosis: Clinical, radiographic and densitometric features, and implications for clinical monitoring and intervention.

GM1 gangliosidosis is a lysosomal storage disorder caused by mutations in GLB1 encoding a lysosomal β-galactosidase. This disease is a continuum from the severe infantile form with rapid neurological decline to the chronic adult form, which is not life-limiting. The intermediate or type 2 form can be further classified into late infantile and juvenile forms. The frequency and severity of skeletal outcomes in late infantile and juvenile patients have not been characterized. Our goals are to describe the radiological skeletal abnormalities, bone mineral density (BMD), and frequency of fractures in patients with intermediate GM1 gangliosidosis. We evaluated 13 late infantile and 21 juvenile patients as part of an ongoing natural history study. Average time from onset of symptoms to diagnosis was 1.9 and 6.3 years for late infantile and juvenile patients, respectively. All late infantile patients had odontoid hypoplasia and pear-shaped vertebral bodies, the frequency of which was significantly different than in patients with juvenile disease (none and 14%, respectively). Juvenile patients had irregular endplates of the vertebral bodies (15/21), central indentation of endplates (10/21), and squared and flat vertebral bodies (10/21); all allowed radiographic differentiation from late infantile patients. Lumbar spine, femoral neck, and total hip BMD were significantly decreased (-2.1, -2.2, and -1.8 Z-scores respectively). Lumbar spine BMD peaked at 19 years, while distal forearm BMD peaked at 30 years. Despite low BMD, no patients exhibited fractures. We have demonstrated that all late infantile patients have some degree of odontoid hypoplasia suggesting the need for cervical spine evaluation particularly prior to anesthesia, whereas juvenile patients had variable skeletal involvement often affecting activities of daily living. Type 2 GM1 gangliosidosis patients have skeletal abnormalities that are both an early indication of their diagnosis, and require monitoring and management to ensure the highest possible quality of life.

EFFECT OF FIELD OF VIEW ON THE ACCURACY OF CONE BEAM COMPUTED TOMOGRAPHIC ASSESSMENT OF ALVEOLAR BONE LOSS IN PERIODONTAL DEFECTS

Objectives: This study aimed to determine the effect of changing the field of view on the ac- curacy of Cone Beam Computed Tomographic assessment of alveolar bone loss in periodontal defects. Materials and methods: 73 natural human teeth naturally attached to ten dry human jaws were used with small linear gutta percha pieces with central indentation glued on their facial and lingual/ palatal surfaces at the place of CEJ, to be used as marker for alveolar bone level measurements both directly using digital caliber with an accuracy of 0.01 mm and radiographically on three CBCT images for each tooth obtained at three different field of views (FOV) (80×80 mm, 100×100 mm and 200× 100 mm) using a standardized voxel size of 0.2 mm, the direct and CBCT measurements were then compared. Results: there was no statistically significant difference between the mean CBCT measure- ments errors at different FOVs. The average CBCT measurements error in the three FOVs (80 × 80mm, 100 × 100 mm and 200× 100 mm) were 0.23±0.09 mm, 0.24± 0.10 mm and 0.21 ± 0.09mm respectively. Conclusions: The FOV size has no significant effect on the CBCT measurements accuracy of the alveolar bone level.

Assessment of intraoperative complications in intumescent cataract surgery using 2 ophthalmic viscosurgical devices and trypan blue staining

To evaluate intraoperative complications during capsulorhexis and phacoemulsification in intumescent white cataracts using 2 ophthalmic viscosurgical device (OVD) techniques. Ruhr University Eye Clinic, Bochum, Germany. Case series. Patients with eyes with intumescent white cataract were recruited and placed in 2 groups. After capsule staining using trypan blue, a central indentation of the anterior lens capsule was created in the eyes in Group 1 using a medium-viscosity OVD (Healon 1.0%) and in the eyes in Group 2 using both medium-viscosity (1.0%) and high-viscosity (2.3%) OVDs. Then a continuous curvilinear capsulorhexis (CCC) was performed. The outcomes measured were the horizontal and vertical diameters of the CCC, the deviation from the target diameter, and intraoperative complications. In Group 1 (21 eyes), deviation from the target CCC diameter occurred in 12 eyes (10 oversized, 2 undersized), and in Group 2 (20 eyes) deviation occurred in 6 eyes (4 oversized, 2 undersized). In Group 1, capsule tears appeared in 2 eyes and in 1 eye, the procedure had to be converted to extracapsular cataract extraction with anterior vitrectomy. In Group 2, there were no capsule tears. Using 2 different OVDs and placing the high-viscosity OVD centrally led to safe indentation of the anterior lens capsule and reduced the risk for CCC enlargement and capsule tear during surgery. No author has a financial or proprietary interest in any material or method mentioned.

A Case Report of Eyebrow Basal Cell Carcinoma Successfully Treated with 5% Imiquimod Cream

3 , Seoul, Korea Purpose: Basal cell carcinoma is the most common malignant neoplasm of the skin. Periorbital basal cell carcinoma needs to be treated for cosmetic improvement and prevention of intraorbital invasion. Although surgical excision is a standard treatment, nonsurgical treatment using imiquimod cream, a topical immunomodulator, has been attempted. The authors report the first case of periorbital basal cell carcinoma successfully treated with imiquimod cream; to the best of our knowledge, similar cases have not been published to date in the Korean ophthalmology journals. Case summary: A 73-year-old female visited our hospital for treatment of a biopsy-proven basal cell carcinoma in the right eyebrow. A flat, elevated, 1 x 1 cm-sized mass having central indentation was observed in the centromedial area of the right eyebrow. She was treated with 5% imiquimod cream once daily at night, 5 days per week for 6 weeks. Eight weeks after the treat- ment with imiquimod cream was discontinued, the mass was flattened and the cilia began to grow on the mass site. Under the impression of a partial regression, an additional 4 weeks of application was recommended. The mass disappeared more and her eyebrow became more normal. At the final follow-up 31 months after treatment, her right eyebrow appeared normal. Conclusions: Imiquimod cream may be a useful medication which can be used for complex periorbital basal cell carcinomas that are difficult to reconstruct after resection or surgical candidates with poor general condition. J Korean Ophthalmol Soc 2015;56(11):1789-1793

A new form of severe spondyloepimetaphyseal dysplasia: Clinical and radiological characterization

We report on two patients with a severe form of spondyloepimetaphyseal dysplasia (SEMD). Both patients show normal birth length, early postnatal growth deficiency, severe short stature, flexion contractures in the hips, bowing of the legs with genu varum. Skeletal radiographies show platyspondyly and characteristic vertebral body shape with central indentation of endplates, progressive, and severe metaphyseal changes, very small and irregular proximal femoral epiphyses with severe coxa vara, absence of calcifications, and mild metaphyseal irregularities in upper limbs. The similarities in the skeletal radiographs with SEMD type Strudwick and SEMD matrilin 3 type prompted us to analyze the COL2A1 and MATN3 genes. Direct sequencing of genomic DNA failed to identify any mutation in COL2A1 for both patients and MATN3 sequencing for Patient 1 identified only one heterozygous variant with no predicted damaging effect inherited from an unaffected parent. We therefore conclude that this form of SEMD probably differs from SEMD matrilin 3 type and does not belong to the spectrum of type II collagenopathies. The similarities between our two patients allowed us to propose that they might show a new form of SEMD.

Tokens of love: possible diagnostic value of mating plugs and refractive secretory uterine structures in Trichodorus (Diphtherophorina: Trichodoridae)

Within the Trichodoridae, mating plugs have only been recorded from Trichodorus species. They can be observed as a clear plug within the vagina/vulva but may also be present in the uteri. These secretory structures are diverse in size, varying between 4 and 27 μm in length, and in shape from simple unipartite tubular structures to bipartite with a central indentation or with a tail-like end. All mating plugs possess a central canal that can vary in diameter. Within Trichodorus, the shape and structure of the mating plugs can provide additional diagnostic information at species level.

Indentation behavior of functionally graded Al–SiC metal matrix composites with random particle dispersion

This study addresses the effects of number of layers, compositional gradient exponent (material composition) and random particle dispersion on the indentation behavior of a functionally graded metal matrix composite. The ceramic particles in a certain volume fraction were randomly distributed within each layer depending on the compositional gradient exponent in order to have a similar structure to an actual microstructure as possible. Increasing the number of layers caused an evident increase in indentation depths for all compositional gradient exponents. The compositional gradient exponent had an important effect on the indentation depth. The random particle dispersion also played an important role on the central indentation depth ( n < 3) as well as on the deformed surface profiles for both high layer numbers ( N = 75 and 150 layers) and the material compositions approaching to a metal-rich structure resulted in some fluctuations in the deformed surface profiles. Increasing the number of layers at a certain compositional gradient exponent resulted in larger mean residual stresses and plastic deformations. Increasing the compositional gradient exponent at a certain layer number decreased mean residual stresses and strains since the ceramic volume fraction is increased. The random particle dispersion also resulted in non-uniform residual stress and strain levels and distributions.

Dynamic corneal imaging

To determine the clinical practicability of in vivo dynamic corneal imaging (DCI) to assess the individual elastic properties of normal human eyes, eyes with abnormal findings, and eyes after refractive surgery. University Eye Clinic, Paracelsus Private Medical University, Salzburg, Austria. The DCI method uses sagittal, stepwise, central indentation of the cornea with electronically controlled microprecision motors and sequential registration of videotopography images. The indentation steps are preselected and range from 50 to 800 mum. The computerized analysis of the videotopography images captured during the process uses Zernike polynomials to establish a newly defined flexing curve for normal eyes and eyes with abnormal findings. Dynamic corneal imaging was done in 187 eyes of 103 patients who had clinically healthy corneas, distinct keratoconus, or previous refractive surgery. The method rapidly evaluated artificially and reversibly induced changes in corneal topography in a clinical setting using a modified Placido disk-based computer-assisted videokeratography system with a small cone. In early analysis, the flexing curve showed a significant correlation with the applied indentation depth. Factors influencing the shape of the curve were central corneal thickness, intraocular pressure, and patient age. The DCI method also allowed easy examination of keratoconic corneas and corneas after refractive surgery. Dynamic corneal imaging induced a reproducible and reversible change in corneal topography corresponding to the different indentation depths. The results indicate that several clinical parameters are correlated with corneal elastic behavior in vivo and that the technology could increase the predictability of refractive corneal surgery and help in the early diagnosis of corneal diseases and with newly developed therapies.

Surgery for carotid dural ring aneurysms

Carotid aneurysms of the paraclinoid segment are usually located in the intradural space, but can infrequently straddle the intra- and extradural space. We present 2 cases of unruptured carotid dural ring aneurysms with an aneurysmal sac that straddled the distal dural ring. Each paraclinoid aneurysm projected superiorly from the anterior surface of the internal carotid artery with a relatively flattened dome and central indentation on angiography. The aneurysmal domes were circumscribed by the distal dural ring and straddled the intra- and extradural space. After broad opening of the distal dural ring, aneurysms were successfully obliterated by clip application in parallel with the internal carotid artery. These cases underscore the significance of an aneurysmal dome indentation on angiographic images as a reflection of aneurysmal circumscription by the distal dural ring. Aneurysms that straddle the intra- and extradural space may require broad opening of the distal dural ring for adequate control and clipping.

Surgery for carotid dural ring aneurysms

Background Carotid aneurysms of the paraclinoid segment are usually located in the intradural space, but can infrequently straddle the intra- and extradural space. Case description We present 2 cases of unruptured carotid dural ring aneurysms with an aneurysmal sac that straddled the distal dural ring. Each paraclinoid aneurysm projected superiorly from the anterior surface of the internal carotid artery with a relatively flattened dome and central indentation on angiography. The aneurysmal domes were circumscribed by the distal dural ring and straddled the intra- and extradural space. After broad opening of the distal dural ring, aneurysms were successfully obliterated by clip application in parallel with the internal carotid artery. Conclusion These cases underscore the significance of an aneurysmal dome indentation on angiographic images as a reflection of aneurysmal circumscription by the distal dural ring. Aneurysms that straddle the intra- and extradural space may require broad opening of the distal dural ring for adequate control and clipping.

A plastic plate facilitating the monitoring of fluid absorption during general anaesthesia

A plastic plate facilitating the monitoring of fluid absorption during general anaesthesia

Circular grating-coupled surface-emitter with high-quality focused output beam

We have investigated the effect of resonator size and geometry on the performance of focusing circular grating-coupled surface-emitting lasers. Both the effects of reducing the resonator diameter and introducing an unpumped indentation in the center of the resonator have been studied. We have found that inclusion of such an unpumped central indentation can greatly improve the spatial-mode behavior, resulting in a very uniform near-field intensity, single wavelength emission, and a focused spot size only 1.5 times the diffraction limit for a laser oscillating in the fundamental circular mode. Reducing the resonator diameter of lasers without an unpumped central indentation does not offer similar improvement.

Radar Observations of Asteroid 1620 Geographos

Goldstone radar observations of Geographos from August 28 through September 2, 1994 yield over 400 delay-Doppler images whose linear spatial resolutions range from ∼75 to ∼151 m, and 138 pairs of dual-polarization (OC, SC) spectra with one-dimensional resolution of 103 m. Each data type provides thorough rotational coverage. The images contain an intrinsic north/south ambiguity, but the equatorial view allows accurate determination of the shape of the radar-facing part of the asteroid's pole-on silhouette at any rotation phase. Sums of co-registered images that cover nearly a full rotation have defined the extremely elongated shape of that silhouette (S. J. Ostro, K. D. Rosema, R. S. Hudson, R. F. Jurgens, J. D. Giorgini, R. Winkler, D. K. Yeomans, D. Choate, R. Rose, M. A. Slade, S. D. Howard, and D. L. Mitchell 1995,Nature375, 474–477). Here we present individual images and co-registered sums over ∼30° of rotation phase that show the silhouette's structural characteristics in finer detail and also reveal numerous contrast features “inside” the silhouette. Those features include several candidate craters as well as indications of other sorts of large-scale topographic relief, including a prominent central indentation. Protuberances at the asteroid's ends may be related to the pattern of ejecta removal and deposition caused by the asteroid's gravity field. The asteroid's surface is homogeneous and displays only modest roughness at centimeter-to-meter scales. Our estimates of radar cross section and the currently available constraints on the asteroid's dimensions are consistent with a near-surface bulk density between 2 and 3 g cm−3. The delay-Doppler trajectory of Geographos' center of mass has been determined to about 200 m on August 28 and to about 100 m on August 31, an improvement of two orders of magnitude over pre-observation ephemerides.

Unerwarteter klinischer Verlauf eines Keratoakanthoms

Patient A 67-year-old man suffered from a tumor of the right upper eyelid. Initially a chalazion was suspected, but the lesion developed central indentation and infiltrated the whole eyelid within three weeks. Methods A biopsy was taken in another clinic. A keratoacanthoma was diagnosed, however a squamous cell carcinoma could not be excluded definitely. Because of enlargement of the tumor and ulceration of the lid margin we removed the tumor completely with reconstruction of the eyelid. After one year no recurrence was observed. Conclusion A lid lesion of this size has not been described in the literature.

Effect of preform shape on buckling of quasi-isotropic thermoplastic composite laminates during sheet forming

Abstract An important issue in sheet forming of continuous fibre-reinforced thermoplastic composites is the tendency of the laminates to buckle out of plane under rapid forming conditions. This paper outlines a method used to predict the stress patterns responsible for buckling, and presents experimental results that correspond with the predictions. A finite element formulation for ideal fibre-reinforced Newtonian fluids, featuring the twin kinematic constraints of material incompressibility and fibre inextensibility, is used. A mixed penalty finite element approach is adopted, with independent interpolation of tension and velocity solution fields. An analysis model consistent with an assumption of plane stress is used. For multi-ply lay-ups, each ply is analysed individually, and average stress predictions for the laminate are obtained on this basis. A detailed comparison between numerical stress predictions and experimental buckling patterns is presented for central indentation of circular unidirectional, cross-ply and quasi-isotropic preforms. Parameters influencing the magnitude and location of peak tangential stresses include tangential fibre lengths and diaphragm/composite viscosity ratios. The effect of sheet width and shape on the instability patterns is investigated for quasi-isotropic laminates of different shapes, using both numerical and experimental techniques.

Structure of the light harvesting antenna from Rhodospirillum molischianum studied by electron microscopy

The structure of two types of isolated light-harvesting antenna complexes from Rhodospirillum molischianum was studied by electron microscopy and image analysis. The B870 reaction center complex forms an almost circular particle with a diameter in the plane of the membrane of about 10.7–11.2 nm. A complex consists of a reaction center surrounded most likely by 12 B870 antennae units. An asymmetrical protrusion, consisting of the cytochrome subunit, gives the reaction center a height of 11.5 nm. The peripheral B800–820 complex is cylindrical, with a diameter of 5.3 nm and a small central indentation. At low resolution, it is structurally very similar to the B800–850 complex of Rhodobacter sphaeroides and is considered to be most likely of the α 6 β 6 type.

Numerical analysis of stresses and deformations in composite materials sheet forming: central indentation of a circular sheet

A finite element model is presented for the analysis of predominantly planar composite sheet-forming problems and the numerical results compared with experimental observations. The problem of diaphragm forming a small indentation in the centre of a large composite sheet is treated in detail, by considering uniform radial velocity or pressure boundary conditions at the inner radius. The analysis is carried out for a single ply, which is assumed to behave as a transversely isotropic, incompressible Newtonian fluid at forming temperature. The presence of high volume fractions of continuous elastic reinforcing fibres in the molten polymer leads to the kinematic constraint of inextensibility in the fibre direction, and associated arbitrary tension stresses. A mixed penalty numerical formulation is constructed by discretizing the weak forms of the constraint and governing equations for creeping flow, using independent interpolation of the velocity and tension stress fields. Deformation fields are depicted at each step in the forming process and are shown to be kinematically dominated by the inextensibility of the fibres. Two modes of instability are predicted in the composite laminates: shear-buckling due to the presence of tangential compressive stresses at 45° to the fibre directions; and columnar buckling due to compressive axial stresses in the fibre direction. These compressive stresses are shown to depend on the forming rate, material viscosities, composite sheet dimensions and diaphragm stiffness. Comparisons with relevant experimental observations are included throughout.

Aortic valve regurgitation and the congenitally bicuspid aortic valve: a clinico-pathological correlation.

To investigate the morphology of congenitally bicuspid aortic valves causing pure valve regurgitation. A case series collected over five years. An academic hospital. One hundred and forty eight excised congenitally bicuspid aortic valves. The morphological findings were correlated with sex, age, clinical history, and data on haemodynamic function before operation. Pure valve regurgitation was defined as grade 3-4/4 with a gradient less than 30 mm Hg. Aortic root dilatation was evaluated angiographically or echocardiographically or both. Three types were recognised: valves that were purely bicuspid (23%), bicuspid valves with a raphe (34%), and valves with an additional indentation of the free edge of the conjoined cusp (43%). In 14 cases pure valve regurgitation was present. Dilatation of the aortic root was present in 47 cases. The relative risk for regurgitation when the aortic root was dilated (compared with no dilatation) was 3.99. The relative risk for valve regurgitation when there was indentation of the conjoined cusp (compared with no indentation) was 4.95. The mean age at operation in patients with pure regurgitation was 56 years, which is significantly younger (p = 0.0008) than that of patients with a congenitally bicuspid valve with combined valve stenosis and regurgitation (64.7 years). Congenitally bicuspid aortic valves with a central indentation of the free edge of the conjoined cusp seem particularly likely to develop pure aortic valve regurgitation.

Ordered arrays of the photosystem I reaction centre after reconstitution: projections and surface reliefs of the complex at 2 nm resolution.

We present an electron microscopical analysis of the photosystem I reaction centre, the membrane complex involved in the second light-driven step of photosynthetic electron transfer in plants and cyanobacteria. To this end, ordered two-dimensional arrays were reconstituted from detergent solubilized photosystem I reaction centres and phospholipids, and studied by electron microscopy and digital image processing. Small (P1) and large (P3) hexagonal lattices obtained with reaction centres of the thermophilic cyanobacterium Phormidium laminosum had unit cell sizes of a = b = 8.8 nm and 15.8 nm, respectively. Reaction centres of a second thermophilic strain, Synechococcus sp. OD24, gave square lattices (a = b = 14.5 nm; P2(1)). Irrespective of the packing arrangement, projections of negatively stained photosystem I complexes showed elongated asymmetric shapes with a large domain at one end which was tilted with respect to a small domain forming the tip of the other end. Such features were also found in averaged projections of solubilized reaction centre trimers. Surface reliefs reconstructed from freeze-dried metal-shadowed P2(1) lattices revealed that reaction centres had a ridge of 2.5 nm height projecting from one side of the membrane while their other side was rather flat and exhibited a shallow, central indentation.