Localized Attachment Research Articles

Localized Attachment Loss in Pendred Syndrome: Incidental?

Pendred syndrome is a rare, inherited, autosomal recessive disorder with an iodine organification defect of thyroxin produced by the thyroid gland. Its clinical features include sensorineural hearing loss, classically congenital and prelingual, and goiter. This is the first case report of Pendred syndrome in the dental literature with oral findings that include localized extensive attachment loss involving mandibular incisor teeth and idiopathic hypercementosis involving multiple teeth in addition to other oral manifestations, suggesting hypothyroidism-like macroglossia and macrocheilia. Furthermore, serum alkaline phosphatase along with inorganic calcium and phosphate levels were also elevated. Peripheral neutrophil function test suggested a defective function of neutrophils. Management of the case included augmenting thyroxin supplementation, in consultation with an endocrinologist, and extraction of hopeless mandibular central incisors followed by placement of immediate transitional dentures. A comprehensive medical history and systemic and laboratory evaluations should be considered a prerequisite to identify, manage, and report such rare conditions in routine clinical practice.

The Papilla Amplification Flap for the Treatment of a Localized Periodontal Defect Associated With a Palatal Groove

Teeth with a palatal groove often present with severe localized periodontal attachment loss including pocket formation and alveolar bone loss. The aim of the present case report was to describe the regenerative surgical treatment of periodontal and bone lesions associated with the subgingival extension of a palatal groove affecting a maxillary lateral incisor. The left maxillary lateral incisor of a systemically healthy young subject presented with a palatal probing depth of 10 mm with no gingival recession at the buccal and palatal surfaces; the neighboring interdental papillae were intact. The radiograph showed a radiolucency area distal to the affected tooth. Treatment procedures consisted of: 1) the papilla amplification flap with the use of enamel matrix proteins as the regenerative periodontal material; 2) the elimination/flattening of the radicular portion of the palatal groove; and 3) the sealing of the coronal portion of the groove with composite flow. The clinical examination at 1 year revealed a clinical attachment gain (8 mm) with a shallow residual probing depth (2 mm) and no increase in gingival recession. The radiographic examination showed the complete disappearance of the radiolucency area suggesting bone fill. The present study indicated that localized periodontal defects associated with a palatal groove can be successfully treated by means of the papilla amplification flap with the use of enamel matrix protein as the regenerative material. The long-term stability of such successful results needs to be determined.

Electrostatic-Gated Transport in Chemically Modified Glass Nanopore Electrodes

Electrostatic-gated transport in chemically modified glass nanopore electrodes with orifice radii as small as 15 nm is reported. A single conical-shaped nanopore in glass, with a approximately 1 microm radius Pt disk located at the pore base, is prepared by etching the exposed surface of a glass-sealed Pt nanodisk. The electrochemical response of the nanopore electrode corresponds to diffusion of redox-active species through the nanopore orifice to the Pt microdisk. Silanization of the exterior glass surface with Cl(Me)(2)Si(CH(2))(3)CN and the interior pore surface with EtO(Me)(2)Si(CH(2))(3)NH(2) introduces pH-dependent ion selectivity at the pore orifice, a consequence of the electrostatic interactions between the redox ions and protonated surface amines. Nanopore electrodes with very small pore orifice radii (< approximately 50 nm) display anion permselectively at pH < 4, as demonstrated by electrochemical measurement of transport through the pore orifice. Ion selective transport vanishes at pH > 6 or when the pore radius is significantly larger than the Debye screening length, consistent with the observed ion selectivity resulting from electrostatic interactions. The ability to introduce different surface functionalities to the interior and exterior surfaces of glass nanopores is demonstrated using fluorescence microscopy to monitor the localized covalent attachment of 5- (and 6)-carboxytetramethylrhodamine succinimidyl ester to interior pore surfaces previously silanized with EtO(Me)(2)Si(CH(2))(3)NH(2).

Role of tethering factors in secretory membrane traffic

Coiled-coil and multisubunit tethers have emerged as key regulators of membrane traffic and organellar architecture. The restricted subcellular localization of tethers and their ability to interact with Rabs and soluble N-ethylmaleimide-sensitive factor attachment protein receptors (SNAREs) suggests that tethers participate in determining the specificity of membrane fusion. An accepted model of tether function considers them molecular "bridges" that link opposing membranes before SNARE pairing. This model has been extended by findings in various experimental systems, suggesting that tethers may have other functions. Recent reports implicate tethers in the assembly of SNARE complexes, cargo selection and transit, cytoskeletal events, and localized attachment of regulatory proteins. A concept of tethers as scaffolding machines that recruit protein components involved in varied cellular responses is emerging. In this model, tethers function as integration switches that simultaneously transmit information to coordinate distinct processes required for membrane traffic.

Spatial profiles of electron swarm properties and explanation of negative mobility of electrons

In this paper, we explain the difference in sign of the flux and bulk drift velocities of a swarm of electrons in constant direct current (dc) and in radio frequency (RF) electric fields under conditions which lead to negative absolute mobility. We have studied (0.5%) F/sub 2//Ar decaying plasma. It was shown that there is a spatial separation of groups of electrons with high and low energy and as a result there is a localization of electron attachment in the region of low energy. Finally, we show that the positive value of the bulk mobility and its delay in RF fields may be explained by a wave of localized attachment that changes the center of mass of the electron swarm.

Gold Functionalized Nano-Needles for Angular Protein Movement Visualization

We have investigated and compared various methods of fabricating silicon nano-needles of 100–200 nm in diameter and 1–2 µm in length for visualization of motor protein movement. Owing to their thin and long geometry, the needles are ideal to amplify and visualize angular movement. To enable highly localized protein attachment, a well-defined attachment point at one end of the needles was prepared. Fabrication by electron-beam lithography as well as by a highly parallel non-lithographic process were implemented and compared. Sensitive angular motion amplification was demonstrated by attachment of needles to F1 ATPase rotation motor proteins. In this report we characterize the fabrication processes, discuss the differences, and present the results of motor protein motion visualization.

Cementodentinal Tear: A Case Report With 7‐Year Follow‐Up

Cemental tears are an uncommon form of root fracture that can lead to rapid localized attachment loss. Typically, the separation of the fragment occurs at the cementodentinal junction. In this report, we present a case of periodontal involvement associated with a cemental tear-like fragment that proved to be a cementodentinal tear. We also review the literature on the clinical presentation of cemental tear associated periodontal lesions. A 52-year-old male presented with acute pain on the maxillary right second premolar. Clinically, probing depth of 7 mm and inflammation were noted on the distal aspect of tooth #4. Radiographic examination revealed separation of cervical root structure on the distal aspect of the tooth, involving two-thirds of the root length. The root fragment was removed, and the localized defect was treated by open flap debridement along with scaling and root planing. The patient was then placed on a regular periodontal maintenance schedule. A postoperative probing depth of 2 mm with 1 mm recession was recorded at 3 months, and maintained for 7 years. Histological examination indicated that the detached root fragment contained dentin with overlying acellular cementum and associated periodontal ligament tissue. The fragment was estimated to represent as much as 20% of the total root surface area. Moderate to severe periodontal attachment loss associated with cemental or cementodentinal tears, even ones constituting a significant portion of the root surface, can be successfully treated with conventional periodontal surgical procedures and maintained long term with a proper maintenance regimen.

Expression and localization of acetylcholinesterase at the neuromuscular junction.

Acetylcholinesterase (AChE) was the first identified synaptic component, characterized by its catalytic affinity for choline esters, and for a long time provided the conceptual scaffold for studies of the neuromuscular junction (NMJ). AChE was the first protein localized to the NMJ, in the 1930s, and its local expression shown to be regulated by the motoneuron in 1937. By the late 1940s a histochemical procedure was developed to visualize the enzyme at synapses, opening up a new era in the study of synaptic structure and function. This enzyme was also the first synaptic component to be purified, quantified, and later crystallized for structural and functional studies. Thus, historically, AChE has played a pivotal role in our understanding of NMJ development and function.AChE occurs in multiple oligomeric forms differing in their hydrophobic character and association with non-catalytic subunits that act as targeting sequences to insure correct localization at the cellular level. The predominant, if not unique, form of the enzyme responsible for terminating neuromuscular transmission is the collagen-tailed form of the enzyme attached to the synaptic basal lamina. This very large protein consists of three catalytic tetramers covalently linked to the three-stranded collagen-like tail (ColQ). The transcripts encoding AChE in muscle are preferentially expressed at sites of nerve-muscle contact and the AChE locally synthesized and assembled. Once externalized, the enzyme appears to be localized through interactions with the proteoglycan perlecan and subsequently covalently attached to the synaptic extracellular matrix. Thus a hierarchical series of events involving localized transcription and translation of the catalytic and non-catalytic subunits, localized assembly and secretion, and finally localized attachment to elements of the extracellular matrix insures that the enzyme is targeted to the correct location.

Pelvic leiomyomatosis with intracaval and intracardiac extension: a case report and review of the literature

Background Intravenous leiomyomatosis with intracaval and intracardiac extension has been rarely described in surgical, gynecological, and radiological literatures. Complete excision of the tumor is essential for a favorable outcome. Because of the uniqueness of this tumor having an absent or localized attachment site, its removal is feasible when assisted, prior to surgery, with appropriate imaging and planning. Case The case was a 46-year-old woman, with intravenous leiomyomatosis originating from the uterus and extending to the inferior vena cava and right atrium, with extensive intracaval attachment, diagnosed from the various preoperative studies and operated successfully through the single-stage approach using cardiopulmonary bypass. Conclusion We present an unusual case of intravenous leiomyomatosis originating from the uterus and extending to the inferior vena cava and right atrium with extensive intracaval attachment. We include a brief review of the literatures.

Role of Oxidized LDL in Atherosclerosis

A critical event in the early stages of atherosclerosis is the focal accumulation of lipid-laden foam cells derived from macrophages. In various cholesterol-fed animal models of atherosclerosis, localized attachment of circulating monocytes to arterial endothelial cells appeared to precede the formation of foam cells. It is suggested that monocyte recruitment into early lesions depends on the endothelial adhesiveness for monocytes and lymphocytes. In vivo and in vitro experiments have identified molecules, such as ICAM-1, VCAM-1, and P-selectin, that can support the adhesion of monocytes and lymphocytes. Moreover, oxidized LDL, lysophosphatidyl-choline, and oxidized fatty acids induce the expression not only of these adhesion molecules but also of scavenger receptors, such as CD-36, SR-A, and LOX-1. Recently, we isolated and characterized the novel receptors for oxidized LDL, namely, LOX-1 and SR-PSOX. Expression of LOX-1 is found on endothelial cells, smooth muscle cells, and macrophages, whereas SR-PSOX is expressed on macrophages. In this paper the significance of oxidized LDL and its receptors, LOX-1 and SR-PSOX, in terms of atherogenesis is discussed.

Wafer scale photonic-die attachment

A diebonding system has been developed for the bonding of photonic chips, such as lasers and photo detectors, at a rate suitable for low cost manufacturing. This system is designed for wafer scale diebonding, making it compatible with wafer scale fabrication. This system combines the passive positional optical alignment of photonic chips on a silicon or glass wafer board surface with materials handling in order to make the process manufacturable. The process is fluxless, minimizing contamination of optical surfaces, and diebonding is controlled to a very small area allowing localized attachment of many die without disturbing previously placed die.

Total Integration of an Ocular Implant/Prosthesis

An ocular implant designed to simplify surgical implantation, minimize infection and extrusion, and improve motility when used as a prosthetic replacement for eyes removed because of damage or disease was tested in rabbit eyes. The implant consisted of a silicone sphere with patches of porous silicone elastomer at the natural insertion sites of the extraocular muscles. Nine implants also had patch material around the base of an integral post designed to distribute the weight of and transfer motility to an overlying prosthetic conformer. Six implants without posts had a circular porous patch on the central anterior surface to facilitate closure of the conjunctiva and Tenon's capsule. Biocompatibility and feasibility were tested in rabbit eyes for < or = 1 year. The patches promoted conjunctival ingrowth, leading to positional stability, and facilitated adherence of the extraocular muscles. Patch material around the post or on the anterior conjunctival surface enhanced conjunctival closure and healing. All 15 implants were retained with no signs of migration, conjunctival dehiscence, or extrusion. Motility on forced duction testing was significant in all directions. The materials appeared to be biocompatible, and the design with the post provided good motility, with the potential for improved coordinated eye movement as a result of the specifically localized attachment of the extraocular muscles.

Pulpal disease and bursts of periodontal attachment loss.

Progression of periodontitis is currently thought to occur during bursts of activity, followed by periods of remission, when healing may occur. This concept contrasts with the older hypothesis that periodontitis was continuously, but slowly, progressive throughout life. At present, there is no proof of the conventional (microbiological) hypothesis which gives a major role to site-specific bacteria in the initiation of bursts of attachment loss. An alternative hypothesis is presented in this paper which accounts for periodontal attachment loss by pathways that are independent of plaque. Severe lesions of the periodontium caused by pulpal pathoses (apical and retrograde periodontitis) are known to form at any level of the periodontium, not only at the root apex. When these lesions cause destruction of the periodontal tissues at the alveolar crest, and when plaque, calculus and gingivitis are also present, an endodontic origin is rarely suspected. Three pathways are proposed to account for the development of localized periodontal attachment loss consequent to pulpal disease. This hypothesis accounts for the sudden deterioration of periodontal sites under regular review, the strict localization of alveolar defects with normal alveolar bone immediately adjacent, the presence of site-specific bacteria (secondary colonizers of deep pockets) which cannot cause disease when transferred to healthy sites, and the antibody responses directed against them.

Escherichia coli O128 strains from infants with diarrhea commonly show localized adhesion and positivity in the fluorescent-actin staining test but do not hybridize with an enteropathogenic E. coli adherence factor probe

Twenty-nine strains of Escherichia coli O128 isolated from infants with diarrhea that did not produce heat-stable enterotoxin, heat-labile enterotoxins, or Vero cytotoxin showed localized attachment to HEp-2 cells (LA). Only four strains hybridized with the enteropathogenic E. coli adherence factor (EAF) probe. One of the 25 LA+ EAF- strains attached to 72% of cells, while a plasmid-negative variant attached to 0.5% of cells. LA+ EAF- and LA+ EAF+ strains gave a positive fluorescent-actin staining test that correlates with the ability to cause attaching and effacing lesions in the intestine. The use of the EAF probe alone to detect LA+ strains is inadequate for epidemiological studies.

Micromanipulation studies of the asymmetric positioning of the maturation spindle in Chaetopterus sp. oocytes: I. Anchorage of the spindle to the cortex and migration of a displaced spindle.

We investigated the nature of the asymmetric positioning and attachment of Chaetopterus oocyte meiotic spindles to the animal pole cortex by micromanipulation. The manipulated spindle's behavior was analyzed in clarified oocyte fragments using video-enhanced polarized light microscopy. As the spindle was drawn towards the cell interior with a microneedle, the cell surface dimpled inwards adjacent to the outer spindle pole. As the spindle was pulled further inwards, the dimple suddenly receded indicating a rupture of a mechanical link between the cell cortex and outer spindle pole. The spindle paused briefly when released from the microneedle; then it spontaneously migrated back to the original attachment site and reassociated with the cell cortex. Positive birefringent astral fibers were seen running between the outer spindle pole and the cortex during the migration. The velocity of the spindle during its migration tended to increase as it came closer to the cortex. Velocities as high as 1.25 micron/sec. were measured. If removed too far from the attachment site cortex (greater than 35 micron), the spindle remained stationary until pushed closer to the original attachment site. Spindles, inverted by micromanipulation, migrated and reattached to the cortical site by their former inner pole; thus either spindle pole can seek out and migrate to the original attachment site. However, spindle poles pushed against other cortical regions did not attach demonstrating that there is only one unique, localized attachment site for spindle attachment.

Frequency distributions of periodontal attachment loss. Computer simulation.

3 patterns of attachment loss were described based on curve fitting the frequency distributions of baseline attachment level measurements of 61 subjects with destructive periodontal diseases. The frequency distributions of attachment level measurements of 30 group I individuals were satisfactorily fit by attachment level measurements of 30 group I individuals were satisfactorily fit by the sum of 2 normal curves, while those of 14 group II individuals were fit by the sum of 3 normal curves. Frequency distributions of 17 group III subjects were fit by a single normal curve. A computer algorithm was used to simulate attachment level loss frequency distributions by varying the "burst size" at active lesions and by imposing "immunity" for varying periods of time on sites which had been attacked. Frequency distributions of group I subjects could be simulated using burst sizes between 0.3 and 3.4 mm. These subjects could be divided into 2 groups: 14 subjects with localized minimal attachment loss required an average burst size of less than 1 mm, while 16 subjects with more destruction at diseased sites required an average burst size of greater than 1 mm to simulate their frequency distributions. Frequency distributions of 16 of 17 group III subjects could be simulated using an average burst size of less than 1 mm. However, the frequency distributions could also be simulated using larger burst sizes with the imposition of "immunity" for substantial periods of time at the attacked sites. The frequency distributions of group II subjects were more difficult to simulate.(ABSTRACT TRUNCATED AT 250 WORDS)

The distribution of fibronectin in attachment sites of chick fibroblasts

Primary chick heart fibroblasts were cultured on glass coverslips and examined by reflection contrast microscopy and then by indirect immunofluorescence microscopy using affinity purified antifibronectin antibody. Fibronectin was found to be primarily localized in areas of ‘close’ contact and in intensely staining fibrous webs that were usually external to the cytoplasmic matrix. Focal contacts, in which there is intimate contact between the cell and the substratum by localized attachment, failed to react with the anti-fibronectin antibody despite a variety of extraction procedures designed to increase the accessibility of antibody to this type of attachment site. It is concluded that in chick fibroblasts, fibronectin participates in cell attachment at areas of close contact and fibrillar attachment sites, but is often excluded from the attachment pads of focal contacts.

THE ORIGIN AND BEHAVIOUR OF CHIASMATA

1. A study of meiosis in male Chorthippus elegans, Acrididae (2n = 16 + X) shows the chromosome behaviour to be similar to that already described in Stenobothrus parallelus. Thus the chiasma frequency is an indirect function of length and has an interference curve of variation. Failure of pairing occurs in one chromosome type with a frequency in keeping with the curve. Terminalization depends entirely on the generalized repulsion in bivalents with closed loops and the localized spindle attachment repulsions are of the minimum degree found in Fritilaria.2. A more extensive quantitative study makes it possible to show in the long chromosome type, that the number of terminal chiasmata at each stage between diplotene and metaphase is proportional to the number of interstitial chiasmata and increases from one stage to the next pari passu with the decrease in the number of the interstitial chiasmata. This confirms the earlier arguments that all interstitial chiasmata become terminal by movement without breakage ...