Superficial Sheets Research Articles

Slippery when wet: The free surface of the articular cartilage.

The free surface of the articular cartilage must withstand compressive and shearing forces, maintain a low friction coefficient and allow oxygen and metabolites to reach the underlying matrix. In many ways it is critical to the physiology of the whole tissue and its disruption always involves deep pathological alterations and loss of the joint integrity. Being very difficult to image with section-based conventional techniques, it was often described by previous research in conflicting terms or entirely overlooked. High-magnification face-on observations with high resolution scanning electron microscopy and with scanning probe microscopy revealed a very thin, delicate superficial layer rich in glycoconjugates, which may explain the very low friction coefficient of the tissue but which was very easily altered and/or dissolved in the preparation. Beneath this superficial sheet lies a thicker coat of thin, highly uniform, slightly wavy collagen fibrils lying parallel to the surface and mutually interconnected by a huge number of interfibrillar glycosaminoglycan bridges. These bridges and the collagen fibrils form an extended reticular structure able to redistribute tensile and compressive stress across a larger area of the surface and hence a greater volume of tissue.

Peeling skin syndrome: an investigational dilemma

<p><span lang="EN-IN">Peeling skin syndrome is a rare autosomal recessive disorder of cornification that starts either at birth or later in childhood, characterized by widespread painless peeling of the skin in superficial sheets. We report the case of a 13-year-old boy who presented with asymptomatic peeling of skin since birth. Sheets of skin were peeling from the neck, trunk and extremities following mild friction or rubbing, with sparing of palms and soles. The case is being reported due to its rarity.</span></p>

Rapid sealing of an alumina nanoporous network grown by anodizing and dye-filled

In the field of indoor decorative items, aluminium alloys are widely used since their surface may be coloured by adsorption of dyes within an anodic nanoporous network. This anodizing/colouring process is followed by a sealing step ensuring the protection of the treated surface without modifying its aesthetic appearance.In the present paper, water, nickel acetate and sodium silicate were used as sealing agents and implemented in rapid sealing processes dedicated to anodized then coloured aluminium surfaces. The morphological aspects were finely observed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The elemental repartition was tracked by wavelength and dispersive spectrometry (WDS/EDS). The sealing efficiency was evaluated by electrochemical impedance spectroscopy (EIS) and a dye spot test. An optical characterization was performed by visible reflection spectrometry and gloss measurements.Both water and nickel salt lead to the precipitation of a few tens of nanometres hydroxide layer, providing an efficient sealing in a short time while maintaining optical properties. Best performances are obtained with nickel salt. In contrast, the high adsorption of silicates inhibits the formation of the sealing superficial sheets on the one hand and even makes the dye desorb from the nanoporous oxide layer.

Direct Visualization and Mapping of the Spatial Course of Fiber Tracts at Microscopic Resolution in the Human Hippocampus.

While hippocampal connectivity is essential to normal memory function, our knowledge of human hippocampal circuitry is largely inferred from animal studies. Using polarized light microscopy at 1.3 µm resolution, we have directly visualized the 3D course of key medial temporal pathways in 3 ex vivo human hemispheres and 2 ex vivo vervet monkey hemispheres. The multiple components of the perforant path system were clearly identified: Superficial sheets of fibers emanating from the entorhinal cortex project to the presubiculum and parasubiculum, intermixed transverse and longitudinal angular bundle fibers perforate the subiculum and then project to the cornu ammonis (CA) fields and dentate molecular layer, and a significant alvear component runs from the angular bundle to the CA fields. From the hilus, mossy fibers localize to regions of high kainate receptor density, and the endfolial pathway, mostly investigated in humans, merges with the Schaffer collaterals. This work defines human hippocampal pathways underlying mnemonic function at an unprecedented resolution.

Clinicopathologic and Diagnostic Features of Esophagitis Dissecans Superficialis

Introduction: Esophagitis dissecans superficialis (EDS) is a desquamative disorder of the esophagus. Little is known about the clinical presentation, predisposing factors, and clinical outcomes of this condition. A cohort of EDS patients were identified and evaluated to further characterize the clinicopathologic features of EDS and to propose diagnostic criteria. Methods: Endoscopy and pathology databases were retrospectively reviewed from 2000-2013 at the Mayo Clinic Rochester to identify potential cases of EDS. Cases were selected based on endoscopic findings and confirmed by re-review of the original pathologic specimens. Clinical, endoscopic, and histologic features of EDS were recorded and evaluated. Results: Forty-one subjects were identified with a mean age of 65.0 years at diagnosis (IQR 52.8-76.1), and 63.4% were female. A large number of patients were taking a psychoactive agent (73.1%) or acid suppressive therapy (58.5%). Endoscopically, strips of sloughed membranes were seen in all patients with a predilection for the distal and/or middle esophagus. Predominant histologic features included parakeratosis (100%) and intraepithelial splitting (86.1%; 25.0% of these showed distinct cysts), while 50.0% or fewer of cases showed partially necrotic long, detached fragments of superficial epithelium. The majority (85.7%) of subjects with endoscopic follow-up showed complete resolution. No complications of stricture or malignancy were noted at a median follow-up of 10.4 months (IQR 1.2-17.2). Conclusion: EDS is a rare entity with a high proportion of individuals with using a psychoactive medication prior to recognition, although the clinical relevance of this association is uncertain. EDS is defined endoscopically by sloughing, superficial sheets of esophageal mucosa and is likely a benign, incidental endoscopic finding without clinical sequelae; however, further studies with prolonged follow-up are needed.

A deep fascia exists in the midface: the missing plane coming from the temporal region (913.4)

Objective of the study: to demonstrate that the deep temporal fascia is connected to the muscles of the infraorbital prezygomatic area and that a deep fascial layer exists in the midface.Methods: 24 hemifaces of 14 caucasian cadavers were dissected. Skin was incised over the temporal and prezygomatic area. The temporoparietal fascia and the Smas layer were dissected and reflected. The superficial sheet of the deep temporal fascia was incised and elevated.In 4 specimens full thickness biopsies were harvested at the level of the zygomatic bones, in the area between the temporal region and the prezygomatic region and observed after cryopreservation.Results: In 12 specimens dissections showed a continuous layer of fascia coming from the temporal area: the superficial sheet of the deep temporal fascia reached directly the prezygomatic area. In 16 specimens the superficial sheet of the deep temporal fascia inserted at the level of the zygomatic as classically described and continued, after inserting, over the prezygomatic area.In all specimens this deep fascial layer devided the fat deep to the orbicularis oculi muscle into 2 layers (suborbicularis oculi and preperiosteal fat) and the deepest one was on the same plane of the temporal fat pad.Histologic examination confirmed the surgical findings: a continuous layer coming from the temporal region reaches the prezygomatic area and devides the fat deep to the orbicularis oculi muscle into 2 layers.Conclusions: A deep fascial plane connected to the superficial sheet of the deep temporal fascia exists in the midface and devides the fat deep to the orbicularis oculi muscle into 2 layers. It can either continue directly from the temporal area or insert over the zygomatic bone and then reach the prezygomatic area. The temporal fat pad situated between the superficial and the deep temporal sheet can be compared to the deep fat layer below the orbicularis oculi muscle.

The Suborbicularis Oculi Fat (SOOF) and the Fascial Planes

During anatomic and surgical dissections, a connection was seen between the superficial layer of the deep temporal fascia and the prezygomatic area. These findings were in contrast to previous evaluations. This study defines this connection, which is important to understand from both surgical and anatomic standpoints. To define the connection between the superficial layer of the deep temporal fascia and the prezygomatic area and demonstrate the presence of a deep fascial layer in the midface. Anatomical study performed at the Laboratoire d'Anatomie de la Faculté de Médecine de Nice, Sophia Antipolis, France; at the Centre du Don des Corps de l'Université Paris Descartes, Paris, France; and at the Department of Experimental Medicine, Histology, and Embryology Unit of the University of Pavia, Pavia, Italy. Twenty-four hemifaces of 14 white cadavers were dissected to define the relationship between deep temporal fascia and the midface. Four biopsy samples were harvested for histologic analysis. Dissection of 24 hemifaces from the fresh cadavers revealed the following findings. There is a connection of the deep fascia of the temple (superficial layer of deep temporal fascia) to the midface that divides the fat deep to the orbicularis muscle into 2 layers. One layer of fat is the so-called suborbicularis oculi fat (SOOF), which is superficial to the deep fascia, and the other layer of fat (preperiosteal) is deep to the deep fascia and adherent to malar bone. These findings are in contrast to previous anatomical findings. RESULTS In 12 hemifaces, the superficial layer of the deep temporal fascia directly reached the prezygomatic area as a continuous fascial layer. In 16 hemifaces, the superficial sheet of the deep temporal fascia inserted at the level of the zygomatic and lateral orbital rim and continued as a deep fascial layer over the prezygomatic area. In all specimens, a deep fascial layer was present in the prezygomatic-infraorbital area. This deep fascial layer is adherent to the muscles of the infraorbital area, and it divided the fat located deep to the orbicularis oculi muscle into 2 layers: the SOOF and a deeper layer. Histologic examination of the biopsy samples confirmed these findings. This study demonstrates the existence of a deep fascial layer in the midface. This fascia is connected to the superficial layer of the deep temporal fascia, and it divides the fat deep to the orbicularis oculi muscle into 2 layers. This new finding carries interesting implications related to the classic concept of the superficial musculoaponeurotic system. NA.

Generalized peeling skin syndrome: Case report and review of the literature

Peeling skin syndrome (PSS) is a rare form of ichthyosis with a probable autosomal recessive inheritance that exhibits superficial, painless, continual, or seasonal cutaneous exfoliation. The syndrome generally appears at birth or in infancy. We report a case of generalized PSS and provide a literature review. A 34-year-old woman reported a lifelong history of generalized and painless peeling of the skin that worsened in summer. Her parents were third degree cousins. Her twin sister and her two cousins presented with the same condition. Physical examination showed widespread superficial sheets of variable size that could be easily removed without bleeding or pain. No underlying erythema was noted. Otherwise, the patient was in good health. Histological findings showed an epidermal cleavage within the stratum corneum. The generalized form of PSS is classified into 3 types, A, B, and C, according to the classification system of Traupe and Mevorah. We have tried to classify the cases of generalized PSS already reported in the literature into one of these three types. Thirteen reported cases probably presented PSS-type A. Sixteen patients are best described as PSS-type B. Two patients exhibit PSS-type C. Fifteen reported patients had an acral form of peeling skin syndrome. The classification of the eleven remaining patients was difficult to determine. Our patient presented clinical and histological features of generalized PSS-type A.

Extramorphological Features of Sauropod Dinosaur Tracks in the Uhangri Formation (Cretaceous), Korea

Sauropod footprints in the Uhangri Formation (Cretaceous) of Korea exhibit an unusual pattern of morphology, with the interior of each print partitioned into a series of pockets by conspicuous radial crests. The crests are evidently extramorphological features and have been interpreted as upwellings of sediment extruded through the floor of the footprint following its fracture by impact of the trackmaker's foot. That explanation entails some inconsistencies, and an alternative explanation is proposed here. The alternative explanation envisages delamination of a superficial sheet of sediment that was lifted into a canopy, which subsequently collapsed in radiating folds. The superficial sheet of sediment might have been lifted by either or both of two mechanisms—by adhering to the underside of the trackmaker's foot or by being forced upward into a blister-like dome by the backflow of water previously displaced by impact of the trackmaker's foot. These alternative explanations draw attention to minor morphological features that were previously unexplained.

Acral peeling skin syndrome

Peeling skin syndrome is a rare autosomal recessive disease characterized by widespread painless peeling of the skin in superficial sheets. We describe a 34-year-old man with a lifelong history of spontaneous asymptomatic peeling skin limited to the acral surfaces. This patient probably represents a localized variant of peeling skin syndrome, which has previously been described as a generalized condition. Light and electron microscopic studies of biopsy specimens taken before and after immersion in water were performed. It was concluded that this patient has abnormal keratohyalin granules and inadequate aggregation of keratin filaments that caused the separation of the epidermis in the stratum corneum through the clear zone. Alternatively, unknown keratin species expressed in the clear zone may also cause the abnormality. (J Am Acad Dermatol 2000;43:1112-9.).

Staphylococcal infections in children: part 3.

1. Anjali Jain, MD* 2. Robert S. Daum, MD* 1. 2. *The Department of Pediatrics, Section of Pediatric Infectious Diseases, The University of Chicago, Chicago IL. After completing this article, readers should be able to: 1. Describe the characteristics of toxic shock syndrome in a young child who has multiple organ failure and shock. 2. Plan therapeutic options for children who have community-acquired staphylococcal infections. 3. Describe the clinical features of a food-borne infectious outbreak that suggest the need to include staphylococcal food poisoning in the differential diagnosis. 4. Plan the antimicrobial therapy of staphylococcal infections. ### TOXIC SHOCK SYNDROME In 1978, Todd et al first described toxic shock syndrome (TSS) in seven children. At about the same time, a marked increase in the number of cases called attention to a possible association between TSS and the use of newly introduced superabsorbent tampons by menstruating women. Between 1980 and 1986, 2,960 cases of TSS were reported to the Centers for Disease Control and Prevention (CDC), 90% of which were associated with menses. In 1980, an epidemiologic link between TSS and the use of super-absorbent tampons was discovered; one brand of these tampons was removed from the market in 1980, and all tampons containing poly-acrylate fibers were removed in 1985. Published reports made it apparent that cases of TSS not associated with menses also occurred infrequently among women as well as men and children. Clinically, nonmenstrual and menstrual TSS are similar entities, but they seem to affect different populations and vary in outcome. Since its peak in the early 1980s, the incidence of TSS has decreased markedly with the institution of preventive measures. However, nonmenstrual TSS has decreased to a lesser extent and now accounts for an increased percentage of all TSS cases, currently about 50%. #### Epidemiology Overall, menstrual TSS occurs at an estimated rate of 1 per 100,000 menstruating women per year, 99% of whom use tampons. The decreased incidence of this disease probably is related to a greater awareness of its presentation, the nonuse …

Autogenous callo-osseous grafts for the repair of osteochondral defects

We describe a new method of biological repair of osteochondral defects. In rabbit knees an osteochondral defect was reconstructed with a callo-osseous graft made of a superficial sheet of medullary fracture callus attached to a base of cancellous bone. This was taken from the iliac bone of the same animal which had been osteotomised ten days earlier. The reparative tissues were evaluated for 24 weeks by quantitative histology, biochemical analysis of the uronic acid content, and immunohistochemical staining of collagen constituents. The callo-osseous graft provided significantly faster and better repair of the articular surface than an untreated defect or a callo-osseous graft in which the cells had been devitalised by irradiation before transplantation. Our findings indicate that the callo-osseous graft contributes to the repair process by providing both favourable extracellular matrices and pluripotential mesenchymal cells. Our study tested the hypothesis that early medullary callus generates hyaline cartilage instead of bone after transfer to an articular surface.

Fixation of mucus on rainbow trout (Oncorhynchus mykiss Walbaum) gills for light and electron microscopy

Fixation of mucus for the assessment of biofilms and surface associated pathogens often involves complex and expensive techniques. Rainbow trout killed by an overdose of MS 222 had their gills removed and immersion‐fixed gently in buffered glutaraldehyde containing 2% Alcian blue. Control tissues consisted of gills fixed in Alcian blue‐free fixative. Trout were also killed and directly immersed in liquid nitrogen and the gills freeze‐dried then vapour fixed with osmium tetroxide at −50° C. Following fixation gill tissue was processed for light and electron microscopy. A continuous and intact mucous coat was not detected on tissue fixed by conventional methods but the addition of Alcian blue to the fixative preserved an extensive mucous coat trapped between the lamellae and overlying the epithelia. Electron microscopic examination revealed that mucus preservation with the conventional fixative was poor and intermittent whereas the addition of Alcian blue to the fixative greatly enhanced the preservation of the branchial mucous coat. Mucus appeared as interdispersed flocculant material between the epithelial microridges and formed extensive superficial sheets over the epithelium. Freeze‐dried/vapour‐fixed gill tissue also provides excellent preservation of the integrity of branchial mucous coats, the mucus appearing as a continuous sheet over the filament and secondary lamellae. However, freeze‐dried tissue fails to preserve sufficient cellular integrity for this technique to be useful for light or transmission electron microscopy. The potential for use of glutaraldehyde‐Alcian blue fixed‐gill tissue diagnostically and in research are discussed.

Origin of high acetylcholinesterase activity in the mouse superior colliculus

The acetylcholinesterase activity in the colliculus mainly occurs in two layers and is arranged as a lattice in the intermediate grey layer and as a continuous sheet in the superficial grey layer. Undercutting lesions abolish the lattice in the intermediate grey layer but leave the superficial sheet of activity intact. By contrast the injection of kainic acid into the colliculus leaves the intermediate layer lattice intact while causing a local reduction in the superficial layer. Injections of the retrograde tracer Fluoro-Gold into the colliculus labels cells in the pedunculopontine and laterodorsal tegmental nuclei that contains acetylcholinesterase. Cells in the parabigeminal nucleus are also labelled but these cells contain low levels of cholinesterase. Thus, it is concluded that the lattice in the intermediate layers is mainly dependent on afferents from the laterodorsal tegmental and pedunculopontine nuclei while the sheet in the superficial layers is mainly dependent on intrinsic cells.

Somatotopic organization of cutaneous afferent terminals and dorsal horn neuronal receptive fields in the superficial and deep laminae of the rat lumbar spinal cord

The somatotopic organization of A- and C-afferent fibre terminals in the dorsal horn of the rat lumbar spinal cord was compared with the spatial location of second-order dorsal horn neuronal mechanoreceptive fields. The central terminal fields of the sural, saphenous, and tibial nerve were mapped by labelling the nerves with horseradish peroxidase (HRP). A previous study used the transganglionic transport of wheat germ agglutinin conjugated to horseradish peroxidase (WGA-HRP) to produce a somatotopic map of high-threshold C-fibre terminal fields in lamina II (Swett and Woolf: J. Comp. Neurol. 231:66-77, '85). In the present study the terminal fields of low-threshold A beta afferents that terminate in laminae III and IV were mapped by using unconjugated HRP at prolonged survival times (72 hours). Unfixed tissue was used to increase the sensitivity of the tetramethylbenzidine reaction, thus allowing these afferent terminals to be clearly seen. The general spatial arrangement of the terminal fields in laminae III/IV closely resembled that found in lamina II in the mediolateral and rostrocaudal planes but because of a dorsoventral obliquity of the afferent terminals, the superficial and deeper fields are not in strict vertical register. The input to laminae II-IV of the dorsal horn may therefore be viewed as two horizontally arranged sheets of afferent terminals both accurately representing the skin surface, the more superficial sheet representing the high-threshold C-afferents and the deeper sheet, low-threshold A-beta afferents. The spatial organization of high-threshold A-delta afferents in laminae I and V appears to be quite different, with a transverse rather than a longitudinal orientation. To study dorsal horn cell receptive field organization two single units with mechanoreceptive fields were recorded extracellularly in each of 87 vertical tracks in the lumbar spinal cord, one unit in the superficial dorsal horn and the second in the deep dorsal horn. In general the somatotopic organization of the receptive fields of both sets of units followed that of the afferent terminal fields but there were cells with receptive fields that were anomalous relative to the recording site. No evidence of any vertical relation or columnar arrangement in receptive field size, threshold, or location on the body surface was found when comparing the two units in a pair. Furthermore, no laminar functional specialization was found, the majority of neurones having both low- and high-threshold inputs.(ABSTRACT TRUNCATED AT 400 WORDS)

Loess from the Pleistocene of the Wirral Peninsula, Merseyside

A pale coloured silt from the cliffs at Dawpool has many of the distinctive characteristics of loess. It occurs as a thin, irregular bed in a complex sequence between two thick Pleistocene tills. A sample underwent rapid collapse when flooded under load and was clearly metastable. Grain size analysis revealed a poorly sorted silt with a clay tail. However, scanning electron microscopy showed silt-sized aggregates of clay grade quartz particles. X-ray diffraction indicated the presence of quartz, feldspar, mica, dolomite, calcite and chlorite but no other clay minerals. Parallels are drawn with other loess deposits and with other sediments. The identification of the loess deposit implies a definite order of events and conflicts with the view that there was a single ice advance or that the overlying till was a lacustrine clay. It is suggested that there are two types of loess deposit in Britain: distinct, unweathered, localised beds and thin, weathered, superficial sheets. The former have been recognised only occasionally while the latter occur mainly in the east and south of England and mainly on limestone bedrock. In view of the porous, friable, metastable, homogeneous nature of the sediment at Dawpool it is considered to be a true eolian loess of the first type, hitherto unrecorded from this area.

Reflex Control of Abdominal Flexor Muscles in the Crayfish

ABSTRACT In the crayfish abdomen most of the power for the flexor twitches employed in swimming is supplied by the massive oblique muscles which are innervated by large motor axons from the third root. All of the delicate flexor control of the abdomen is vested in a thin, superficial sheet of muscle fibres which have the histological characteristics of ‘slow’ muscle and are innervated by a special, independent supply of small motor nerves (Kennedy & Takeda, 1965). These forty or so muscle fibres and half-dozen axons comprise a reflex apparatus of exquisite complexity, both with respect to innervation pattern (which ranges from single to sextuple for single muscle fibres) and to central modulation of efferent discharge.