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Retinal Cases & Brief Reports Mar 2023To report a case of Noonan syndrome with multiple lentigines with unusual ocular features.
PURPOSE
To report a case of Noonan syndrome with multiple lentigines with unusual ocular features.
METHODS
The authors describe a case of a 7-year-old girl with Noonan syndrome with multiple lentigines and anomalous optic disks.
RESULTS
A 7-year-old girl with genetically proven Noonan syndrome with multiple lentigines ( PTPN11 gene mutation) and anomalous optic disks was referred for treatment of persistent macular detachment after 1 year of conservative follow-up. The right eye demonstrated an optic disk coloboma with the best-corrected visual acuity of 20/32, the left eye demonstrated an optic disk pit with serous macular detachment (best-corrected visual acuity 20/50-20/80). Optical coherence tomography demonstrated a neurosensory detachment. Twenty-five gauge pars plana vitrectomy was performed with posterior hyaloid detachment, drainage over disk pit area, and SF6 20% gas tamponade. Surgery resulted in subretinal fluid reduction and improvement of the visual acuity to 20/32.
CONCLUSION
A case of Noonan syndrome with multiple lentigines with optic disk coloboma in the right eye and optic disk pit with related maculopathy in the left eye. To the best of the authors' knowledge, this is the first reported case describing the association of Noonan syndrome with multiple lentigines and congenital optic disk anomalies. Optic disk pit maculopathy was managed surgically because of its longstanding nature with the deteriorating visual acuity.
Topics: Female; Humans; Child; Optic Disk; Coloboma; Vitrectomy; LEOPARD Syndrome; Retinal Diseases; Retinal Detachment; Eye Abnormalities; Macular Degeneration; Tomography, Optical Coherence; Pigmentation Disorders
PubMed: 34009903
DOI: 10.1097/ICB.0000000000001144 -
Tissue Engineering and Regenerative... Oct 2018and blasted titanium (Ti) is commonly used in designing endosseous dental implants due to its biocompatibility and ability to form bonds with bone tissues. However,...
BACKGROUND
and blasted titanium (Ti) is commonly used in designing endosseous dental implants due to its biocompatibility and ability to form bonds with bone tissues. However, titanium implants do not induce strong interactions with teeth bones. To increase strong interactions between Ti disk implants and teeth bones, the l-glutamic acid grafted hydroxyapatite nanorods (nHA) were immobilized on albumin modified Ti disk implants (Ti-Alb).
METHODS
For modification of Ti disk implants by nHA, the l-glutamic acid grafted nHA was synthesized and then immobilized on albumin modified Ti disk implants. Fourier transformed infrared spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscope; energy dispersive spectroscopy and confocal laser scanning microscopy were used to confirm the modification of Ti disk implants. The bioactivity of nHA-modified Ti disk implants was evaluated by seeding MC3T3-E1 cells on Ti-nHA implants.
RESULTS
Characterization techniques have confirmed the successful modification of Ti disk implants by l-glutamic acid grafted nHA. The nHA-modified Ti disk implants have shown enhanced adhesion, proliferation and cytotoxicity of MC3T3-E1 cells in comparison to pristine Ti implants.
CONCLUSIONS
The modification of Ti implants by l-glutamic acid grafted nHA has produced highly osteogenic Ti disk plants in comparison to pristine Ti disk implants due to the formation of bioactive surfaces by hydroxyapatite nano rods on Ti disk implants. Ti-nHA disk implants showed enhanced adhesion, proliferation, and MC3T3-E1 cells viability in comparison to pristine Ti disk implants. Thus nHA might be to be useful to enhance the osseointegration of Ti implants with teeth bones.
PubMed: 30603582
DOI: 10.1007/s13770-018-0151-9 -
Journal of Muscle Research and Cell... Apr 2017The Z-disk is a complex structure comprising some 40 proteins that are involved in the transmission of force developed during muscle contraction and in important...
The Z-disk is a complex structure comprising some 40 proteins that are involved in the transmission of force developed during muscle contraction and in important signalling pathways that govern muscle homeostasis. In the Z-disk the ends of antiparallel thin filaments from adjacent sarcomeres are crosslinked by α-actinin. The structure of the Z-disk lattice varies greatly throughout the animal kingdom. In vertebrates the thin filaments form a tetragonal lattice, whereas invertebrate flight muscle has a hexagonal lattice. The width of the Z-disk varies considerably and correlates with the number of α-actinin bridges. A detailed description at a high resolution of the Z-disk lattice is needed in order to better understand muscle function and disease. The molecular architecture of the Z-disk lattice in honeybee (Apis mellifera) is known from plastic embedded thin sections to a resolution of 7 nm, which is not sufficient to dock component protein crystal structures. It has been shown that sectioning is a damaging process that leads to the loss of finer details present in biological specimens. However, the Apis Z-disk is a thin structure (120 nm) suitable for cryo EM. We have isolated intact honeybee Z-disks from indirect flight muscle, thus obviating the need of plastic sectioning. We have employed cryo electron tomography and image processing to investigate the arrangement of proteins within the hexagonal lattice of the Apis Z-disk. The resolution obtained, ~6 nm, was probably limited by damage caused by the harshness of the conditions used to extract the myofibrils and isolate the Z-disks.
Topics: Animals; Bees; Cytoskeleton; Muscle Contraction; Muscle Proteins; Myofibrils
PubMed: 28733815
DOI: 10.1007/s10974-017-9477-5 -
Scientific Reports Mar 2023The terrestrial planets formed by accretion of asteroid-like objects within the inner solar system's protoplanetary disk. Previous works have found that forming a...
The terrestrial planets formed by accretion of asteroid-like objects within the inner solar system's protoplanetary disk. Previous works have found that forming a small-mass Mars requires the disk to contain little mass beyond ~ 1.5 au (i.e., the disk mass was concentrated within this boundary). The asteroid belt also holds crucial information about the origin of such a narrow disk. Several scenarios may produce a narrow disk. However, simultaneously replicating the four terrestrial planets and the inner solar system properties remains elusive. Here, we found that chaotic excitation of disk objects generated by a near-resonant configuration of Jupiter-Saturn can create a narrow disk, allowing the formation of the terrestrial planets and the asteroid belt. Our simulations showed that this mechanism could typically deplete a massive disk beyond ~ 1.5 au on a 5-10 Myr timescale. The resulting terrestrial systems reproduced the current orbits and masses of Venus, Earth and Mars. Adding an inner region disk component within ~ 0.8-0.9 au allowed several terrestrial systems to simultaneously form analogues of the four terrestrial planets. Our terrestrial systems also frequently satisfied additional constraints: Moon-forming giant impacts occurring after a median ~ 30-55 Myr, late impactors represented by disk objects formed within 2 au, and effective water delivery during the first 10-20 Myr of Earth's formation. Finally, our model asteroid belt explained the asteroid belt's orbital structure, small mass and taxonomy (S-, C- and D/P-types).
PubMed: 36973305
DOI: 10.1038/s41598-023-30382-9 -
Clinical Microbiology and Infection :... May 2011The aim of this study was to compare CLSI and EUCAST MIC and disk diffusion carbapenem breakpoints for the detection of carbapenemase-producing Klebsiella pneumoniae. K.... (Comparative Study)
Comparative Study
The aim of this study was to compare CLSI and EUCAST MIC and disk diffusion carbapenem breakpoints for the detection of carbapenemase-producing Klebsiella pneumoniae. K. pneumoniae strains with known KPC (n = 31) or VIM (n = 20) carbapenemases were characterized by disk diffusion (Oxoid) and Etest (bioMérieux) vs. imipenem, meropenem and ertapenem, and with VITEK2 (bioMérieux, five different cards). Extended-spectrum β-lactamase (ESBL) testing was performed with VITEK2 (bioMérieux), ESBL combination disks (Becton Dickinson) and the ESBL Etest (bioMérieux). With CLSI and EUCAST MIC breakpoints, respectively, 11 and seven of the strains were susceptible to imipenem, 12 and eight to meropenem, and seven and none to ertapenem. The EUCAST epidemiological cut-off (ECOFF) values for meropenem and ertapenem identified all carbapenemase producers, whereas the imipenem ECOFF failed in five strains. All carbapenemase producers were detected with EUCAST disk diffusion breakpoints for ertapenem and meropenem, and four strains were susceptible to imipenem. CLSI disk diffusion breakpoints characterized 18 (imipenem), 14 (meropenem) and three (ertapenem) isolates as susceptible. When cards with a single carbapenem were used, detection failures with VITEK2 were four for imipenem, none for meropenem and one for ertapenem. Cards containing all three carbapenems had one to two failures. With ESBL combination disks, 21/31 KPC producers and 2/20 VIM producers were positive. With VITEK2, no VIM producers and between none and seven KPC producers were ESBL-positive. All carbapenemase producers were detected with the meropenem MIC ECOFF, or the clinical EUCAST breakpoint for ertapenem. EUCAST disk diffusion breakpoints for meropenem and ertapenem detected all carbapenemase producers. VITEK2 had between none and four failures in detecting carbapenemase producers, depending on the antibiotic card.
Topics: Anti-Bacterial Agents; Bacterial Proteins; Disk Diffusion Antimicrobial Tests; Ertapenem; Imipenem; Klebsiella pneumoniae; Meropenem; Microbial Sensitivity Tests; Microbiological Techniques; Thienamycins; beta-Lactamases; beta-Lactams
PubMed: 20649801
DOI: 10.1111/j.1469-0691.2010.03299.x -
Reproduction & Fertility Jul 2022During fertilization, avian sperm preferentially penetrate into the perivitelline membrane that covers the germinal disk region where the female nucleus is present. This...
ABSTRACT
During fertilization, avian sperm preferentially penetrate into the perivitelline membrane that covers the germinal disk region where the female nucleus is present. This phenomenon has been observed not only in domestic birds but also in wild birds; however, the mechanisms controlling sperm preference are still unclear. In this study, we investigated the possible involvement of annexin family protein in sperm-egg interaction in Japanese quail. Microscopic examination of fertilized eggs indicated that quail sperm penetration only occurred in the germinal disk region, and sperm localized outside the germinal disk were trapped in the perivitelline membrane. Western blot analysis and immunofluorescence microscopy revealed the presence of annexin A1 and A6 in the oocyte membrane, while annexin A6 localized in the perivitelline space of the germinal disk region. Further, our sperm binding assay using recombinant annexin A6 demonstrated that ejaculated sperm specifically bound to annexin A6 expressed in mammalian cell lines. These results suggest that annexin A6, which is expressed on the surface of oocytes, may function in sperm-egg interaction in the germinal disk region and that this binding may ensure sperm retention on the surface of the egg plasma membrane until fertilization takes place in Japanese quail.
LAY SUMMARY
In bird species, fertilization takes place immediately after ovulation of the egg. Sperm preferentially penetrate a specific area of the egg coating that covers the 'germinal disk region' - this area contains the cell that needs to be fertilized by a sperm. However, since the bird egg is extremely large in size and sperm must reach the 'germinal disk region' to achieve fertilization, it is unclear how this happens. Annexin proteins support fertilization in mammals, and we found that annexin A6 protein exhibits a unique localization in the germinal disk region in the eggs of Japanese quail. To test this interaction, we incubated quail sperm with cells that produced annexin A6 and found that ejaculated sperm bound to the cells. These results suggest that annexin A6 may have a role in the sperm-egg interaction in the germinal disk region in Japanese quail.
Topics: Male; Female; Animals; Annexin A6; Coturnix; Semen; Sperm-Ovum Interactions; Fertilization; Quail; Mammals
PubMed: 35972319
DOI: 10.1530/RAF-21-0115 -
Oral Surgery, Oral Medicine, Oral... Aug 1998The purpose of this study was to investigate the rotational motion characteristics of the disk-condyle complex in relation to the steepness of the articular eminence of...
OBJECTIVE
The purpose of this study was to investigate the rotational motion characteristics of the disk-condyle complex in relation to the steepness of the articular eminence of the normal temporomandibular joint.
STUDY DESIGN
We studied 14 asymptomatic volunteers with normal temporomandibular joints using magnetic resonance images with gradient recoil acquisition in the steady state. The degree of condyle and disk rotation within the glenoid fossa, the inclination of the condyle path, and the steepness of the articular eminence were measured and correlated.
RESULTS
The condyle and disk both rotated during forward translation within the glenoid fossa during mouth opening. The movement of the disk was smaller than the movement of the condyle, resulting in a posterior rotation of the disk relative to the condyle. The inclination of the condyle path (mean, 61.1 degrees) was significantly smaller than the steepness of the articular eminence (mean, 68.7 degrees). The steepness of the articular eminence was statistically significantly correlated with the degree of disk rotation, which indicated that the disk tended to rotate farther backward in a temporomandibular joint with steeper articular eminence.
CONCLUSION
We found that on mouth opening the disk rotated backward relative to the condyle. The posterior disk rotation was more prominent in joints with a steep articular eminence than in joints with a less steep eminence. The results may be helpful for understanding the biomechanics of the temporomandibular joint, especially relative to the development of disk displacement.
Topics: Adult; Biomechanical Phenomena; Female; Humans; Joint Dislocations; Magnetic Resonance Imaging; Male; Mandible; Mandibular Condyle; Movement; Range of Motion, Articular; Rotation; Temporal Bone; Temporomandibular Joint; Temporomandibular Joint Disc
PubMed: 9720088
DOI: 10.1016/s1079-2104(98)90117-2 -
Proceedings of the National Academy of... Jun 2024Magmatic iron-meteorite parent bodies are the earliest planetesimals in the Solar System, and they preserve information about conditions and planet-forming processes in...
Magmatic iron-meteorite parent bodies are the earliest planetesimals in the Solar System, and they preserve information about conditions and planet-forming processes in the solar nebula. In this study, we include comprehensive elemental compositions and fractional-crystallization modeling for iron meteorites from the cores of five differentiated asteroids from the inner Solar System. Together with previous results of metallic cores from the outer Solar System, we conclude that asteroidal cores from the outer Solar System have smaller sizes, elevated siderophile-element abundances, and simpler crystallization processes than those from the inner Solar System. These differences are related to the formation locations of the parent asteroids because the solar protoplanetary disk varied in redox conditions, elemental distributions, and dynamics at different heliocentric distances. Using highly siderophile-element data from iron meteorites, we reconstruct the distribution of calcium-aluminum-rich inclusions (CAIs) across the protoplanetary disk within the first million years of Solar-System history. CAIs, the first solids to condense in the Solar System, formed close to the Sun. They were, however, concentrated within the outer disk and depleted within the inner disk. Future models of the structure and evolution of the protoplanetary disk should account for this distribution pattern of CAIs.
PubMed: 38805273
DOI: 10.1073/pnas.2306995121 -
Progress in Lipid Research 2005The photoreceptor rod outer segment (ROS) provides a unique system in which to investigate the role of cholesterol, an essential membrane constituent of most animal... (Review)
Review
The photoreceptor rod outer segment (ROS) provides a unique system in which to investigate the role of cholesterol, an essential membrane constituent of most animal cells. The ROS is responsible for the initial events of vision at low light levels. It consists of a stack of disk membranes surrounded by the plasma membrane. Light capture occurs in the outer segment disk membranes that contain the photopigment, rhodopsin. These membranes originate from evaginations of the plasma membrane at the base of the outer segment. The new disks separate from the plasma membrane and progressively move up the length of the ROS over the course of several days. Thus the role of cholesterol can be evaluated in two distinct membranes. Furthermore, because the disk membranes vary in age it can also be investigated in a membrane as a function of the membrane age. The plasma membrane is enriched in cholesterol and in saturated fatty acids species relative to the disk membrane. The newly formed disk membranes have 6-fold more cholesterol than disks at the apical tip of the ROS. The partitioning of cholesterol out of disk membranes as they age and are apically displaced is consistent with the high PE content of disk membranes relative to the plasma membrane. The cholesterol composition of membranes has profound consequences on the major protein, rhodopsin. Biophysical studies in both model membranes and in native membranes have demonstrated that cholesterol can modulate the activity of rhodopsin by altering the membrane hydrocarbon environment. These studies suggest that mature disk membranes initiate the visual signal cascade more effectively than the newly synthesized, high cholesterol basal disks. Although rhodopsin is also the major protein of the plasma membrane, the high membrane cholesterol content inhibits rhodopsin participation in the visual transduction cascade. In addition to its effect on the hydrocarbon region, cholesterol may interact directly with rhodopsin. While high cholesterol inhibits rhodopsin activation, it also stabilizes the protein to denaturation. Therefore the disk membrane must perform a balancing act providing sufficient cholesterol to confer stability but without making the membrane too restrictive to receptor activation. Within a given disk membrane, it is likely that cholesterol exhibits an asymmetric distribution between the inner and outer bilayer leaflets. Furthermore, there is some evidence of cholesterol microdomains in the disk membranes. The availability of the disk protein, rom-1 may be sensitive to membrane cholesterol. The effects exerted by cholesterol on rhodopsin function have far-reaching implications for the study of G-protein coupled receptors as a whole. These studies show that the function of a membrane receptor can be modulated by modification of the lipid bilayer, particularly cholesterol. This provides a powerful means of fine-tuning the activity of a membrane protein without resorting to turnover of the protein or protein modification.
Topics: Animals; Cell Membrane; Cholesterol; Humans; Hydrocarbons; Models, Biological; Optic Disk; Phospholipids; Receptors, G-Protein-Coupled; Retinal Diseases; Rhodopsin; Rod Cell Outer Segment; Vision, Ocular
PubMed: 15924998
DOI: 10.1016/j.plipres.2005.02.001 -
BMJ Open Apr 2018To evaluate the relationship between pupillary response to light, myopia and disk halo size.
OBJECTIVES
To evaluate the relationship between pupillary response to light, myopia and disk halo size.
DESIGN
Cross-sectional study.
SETTING
Single refractive surgery centre.
PARTICIPANTS
In this study, 197 right eyes of 197 patients between 20 and 35 years of age were evaluated for disk halo size and pupillary response to light with a vision monitor.
PRIMARY AND SECONDARY OUTCOME MEASURES
Halo radius, age, spherical equivalent (SE), axial length (AL), initial diameter, amplitude of contraction, latency of contraction, duration of contraction, velocity of contraction, latency of dilation, duration of dilation, velocity of dilation, maximum pupil, minimum pupil, average pupil and dark pupil.
RESULTS
Significant associations were found between disk halo size and SE (r=-0.219, P=0.002), AL (r=0.152, P=0.033) and minimum pupil (r=0.149, P=0.037). There were no associations between disk halo size and initial diameter, amplitude of contraction, latency of contraction, duration of contraction, velocity of contraction, latency of dilation, duration of dilation, velocity of dilation, maximum pupil, average pupil, dark pupil and age (P>0.05). A significant difference in disk halo size was detected between the low-moderate and high myopia (SE< -6 D) groups (P=0.002) and between the small and large (minimum pupil≥4 mm) minimum pupil size groups (P=0.014).
CONCLUSIONS
Patients with a high SE and large minimum pupil size (minimum pupil ≥4 mm) suffered more disability glare than those with a low SE and small minimum pupil size.
Topics: Adult; Cross-Sectional Studies; Germany; Glare; Humans; Light; Myopia; Pupil; Young Adult
PubMed: 29643157
DOI: 10.1136/bmjopen-2017-019914