Soft sheets of fibrillar bone from a fossil of the supraorbital horn of the dinosaur Triceratops horridus.

Soft fibrillar bone tissues were obtained from a supraorbital horn of Triceratops horridus collected at the Hell Creek Formation in Montana, USA. Soft material was present in pre and post-decalcified bone. Horn material yielded numerous small sheets of lamellar bone matrix. This matrix possessed visible microstructures consistent with lamellar bone osteocytes. Some sheets of soft tissue had multiple layers of intact tissues with osteocyte-like structures featuring filipodial-like interconnections and secondary branching. Both oblate and stellate types of osteocyte-like cells were present in sheets of soft tissues and exhibited organelle-like microstructures. SEM analysis yielded osteocyte-like cells featuring filipodial extensions of 18-20µm in length. Filipodial extensions were delicate and showed no evidence of any permineralization or crystallization artifact and therefore were interpreted to be soft. This is the first report of sheets of soft tissues from Triceratops horn bearing layers of osteocytes, and extends the range and type of dinosaur specimens known to contain non-fossilized material in bone matrix.

Repair of orbital wall defects using biocoral scaffolds combined with bone marrow stem cells enhanced by human bone morphogenetic protein-2 in a canine model.

Repair of orbital bone defects caused by trauma, infection or cancer is a continuous challenge in reconstructive surgery. Few studies have reported the application of tissue engineering for the repair of orbital bone defects in large animal models. Thus, we investigated the effects of tissue-engineered bone enhanced by the human bone morphogenetic protein-2 (BMP2) on the repair of orbital wall defects in a canine model. Autologous bone marrow stromal cells (BMSCs) from 16 Beagle dogs were isolated and cultured in vitro. Passage 2 cells were transfected with adenovirus containing human BMP2 (adv-BMP2) and tissue-engineered bone was constructed using BMP2-expressing BMSCs seeded on a biocoral scaffold. Circular defects (12-mm diameter) created bilaterally in the canine medial orbital wall, were treated with one of the following: adv-BMP2-transfected BMSC/coral composite (group I, n=8), BMSC/coral composite (group II, n=8), biocoral alone (group III, n=8), or were left untreated (group IV, n=8). Four samples from each group were harvested at 12 and 24 weeks after surgery, and the volume and density of newly regenerated bone were determined by micro-computed tomographic (micro-CT) measurement. The rate of new bone deposition and regeneration was measured by tetracycline/calcein labeling and histomorphometric analysis. The results showed that a canine 12-mm circular orbital defect was a critical-sized defect, and the micro-CT and histomorphometry detection results indicated that the combined delivery of BMSCs and BMP2 (group I) resulted in the highest regenerative effects on orbital bone defects, compared to the other groups without BMP2. Biocoral scaffolds combined with BMSCs enhanced by BMP2 could improve the healing of critical-sized medial orbital wall defects in canines.

Underdeveloped extraocular muscles in the naked mole-rat (Heterocephalus glaber).

The extraocular muscles (EOM), the effector arm of the ocular motor system, have a unique embryological origin and phenotype. The naked mole-rat (NMR) is a subterranean rodent with an underdeveloped visual system. It has not been established if their ocular motor system is also less developed. The NMR is an ideal model to examine the potential codependence of oculomotor and visual system development and evolution. Our goal was to compare the structural features of NMR EOMs to those of the mouse, a similar sized rodent with a fully developed visual system. Perfusion-fixed whole orbits and EOMs were dissected from adult NMR and C57BL mice and examined by light and electron microscopy. NMR orbital anatomy showed smaller EOMs in roughly the same distribution around the eye as in mouse and surrounded by a very small Harderian gland. The NMR EOMs did not appear to have the two-layer fiber distribution seen in mouse EOMs; fibers were also significantly smaller (112.3 +/- 46.2 vs. 550.7 +/- 226 sq microm in mouse EOMs, *P < 0.05). Myofibrillar density was less in NMR EOMs, and triad and other membranous structures were rudimentary. Finally, mitochondrial volume density was significantly less in NMR EOMs than in mouse EOM (4.5% +/- 1.9 vs. 21.2% +/- 11.6, respectively, *P < 0.05). These results demonstrate that NMR EOMs are smaller and less organized than those in the mouse. The "simpler" EOM organization and structure in NMR may be explained by the poor visual ability of these rodents, initially demonstrated by their primitive visual system.

Reconstruction of orbital defect in rabbits with composite of calcium phosphate cement and recombinant human bone morphogenetic protein-2.

BACKGROUND: Calcium phosphate cement (CPC) is a biocompatible and osteoconductive bone substitute, and recombinant human bone morphogenetic protein-2 (rhBMP-2) has strong osteoinductibility, therefore we developed a composite bone substitute with CPC and rhBMP-2 and evaluate its reconstruction effect in rabbit orbital defect. METHODS: Thirty-six rabbits were randomly divided into two groups and a 5 mm × 5 mm × 2 mm bone defect in the infraorbital rim was induced by surgery in each orbit (72 orbits in all). The orbital defects were treated with pure CPC or composite of CPC and rhBMP-2. The osteogenesis ability of different bone substitute was evaluated by gross observation, histological examination, histomorphometrical evaluation, compressive load-to-failure testing, and scanning electron microscope (SEM). RESULTS: Gross observation showed that both bone substitutes were safe and effective for reconstruction of orbital defect. However, histological examination, histomorphometrical evaluation and SEM showed that CPC/rhBMP-2 group had faster speed in new bone formation and degradation of substitute material than CPC group. Compressive load-to-failure testing showed that CPC/rhBMP-2 group had stronger compressive strength than CPC group at every stage with significant difference (P < 0.05). CONCLUSION: Composite of CPC/rhBMP-2 is an ideal bioactive material for repairing orbital defect, with good osteoconductibility and osteoinductibility.

Scanning electron microscopy of the orbital Harderian gland in the male Atlantic bottlenose dolphin (Tursiops truncatus).

The ultrastructure of the Harderian gland of Atlantic bottlenose dolphin (Tursiops truncatus) was examined by scanning electron microscopy (SEM). We found the following surface features: the typical round appearance of the ascinar glandular unit with a finely granular surface, a thin cortex and immediately below two types of cells: type I cells (characterized by small lipid vacuoles) and type II cells (characterized by large lipid vacuoles). It has been suggested that different cells forms represent a single cell type in varying activity states. Additionally, a coalescent tubular complex, a small balloon-like structures and large globular structures were observed. These structures may be reservoirs of secretion products.

Anatomy, histology, histochemistry and fine structure of the Harderian gland in the South American armadillo Chaetophractus villosus (Xenarthra, Mammalia).

The anatomical, histological, histochemical and ultrastructural characteristics of the Harderian gland of the armadillo Chaetophractus villosus were described. The gland is the largest structure in the bony orbit. It is situated in the anteroventral region of the orbit. Obvious structural differences are not observed between males and females. The gland is compound-branched tubulo-alveolar, being characterized by a single layer of columnar cells surrounded by myoepithelial cells. It possesses a single excretory duct opened into the inner canthus. All glandular cells show yellow-green autofluorescence and additionally some glandular lumen may contain dense autofluorescent solid accretions. There are two peculiar and outstanding cytoplasmic features. One is represented by the smooth endoplasmic reticulum (SER), forming a closely woven meshwork. The other one is represented by "membranous bodies" apparently derived from the SER, RER and cytoskeleton with a "Star of David" configuration situated in the supranuclear region. Three types of vesicles are detected in the cytoplasm. Histochemical staining methods reveal lipids, proteins, neutral and acidic containing glycoconjugates in secretory vesicles. The mechanism of secretion appears either merocrine or apocrine. The epithelium of the intra- and inter-lobular excretory ducts suggests secretory activity. Tubulo-acinar glands similar to those seen in the lacrimal gland and nictitans glands are found related to the intralobular and main excretory ducts. The capillary network is characterized by fenestrated endothelium. The stroma possesses unmyelinated axons and plasma cells. The normal secretion of the secretory endpieces, particularly lipids, proteins and glycoconjugates, is complemented by mucous and serous secretions released by ductal cells and glands associated to the ducts.

Structural details of rat extraocular muscles and three-dimensional reconstruction of the rat inferior rectus muscle and muscle-pulley interface.

Light microscopy, electron microscopy and morphometry revealed structural details and allowed generation of a three-dimensional reconstruction of the pulley and muscle-pulley interface of extraocular muscle. The inferior rectus orbital layer was bifurcate in shape and extended anterior to the pulley. The putative pulley structure itself was asymmetric; loosely attached at the orbital aspect it adhered tightly to the global aspect of muscle. Orbital multiply innervated fiber proportion increased anterior to the pulley insertion site. Additionally longitudinal variation in juxtaposition of orbital and global layers was noted. These newly described structural details provide novel mechanistic insight for extraocular muscle function in rats.

Oclusão combinada de artéria e veia central da retina associada a drusas de disco óptico / Combined central retinal artery and vein occlusion associated with optic disc drusen

Relatamos uma rara associação entre oclusão combinada de artéria e veia central da retina como drusas do nervo óptico. Descrevemos exames complementares que definiram o diagnóstico e o tratamento realizado. Foram feitos avaliação oftalmológica, clínica e laboratorial, retinografia, angiografia fluorosceínica, ultrasonografia ocular e tomografia computadorizada de órbita e crânio. O tratamento realizado foi vitrectomia via pars plana e endofotocoagulação. pacientes com perda súbita a visão no olho direito, apresentou na oftalmoscopia indireta drusas de nervo óptico, aumento da tortuosidade vascular, hemorragias vítreas e intra-retinianas, branqueamento e edema retiniano difuso. A angiografia fluoresceínica do olho direito mostrou lentificação dos tempos circulatórios e hiperfluoresc6encia por impregnação no nervo óptico. A ultrasonogafia ocualr mostrou estrutura de alta refletividade nos nervos ópticos, e calcificações na tomografia computadorizada de órbita, confirmando o diagnóstico das drusas. Devido a extensaisquemia, houve uma rápida evolução para neovasculização retiniana com episódios repetidos de hemorragia vítrea, sendo indicado vitrectomia posterior e endofotocoagulação difusa. Descrevemos pela primeira vez na literatura uma associação entre drusas de nervo óptico com oclusão combinada de artéria e veia central da retina. Acreditamos que a presença das drusas foi o principal fator na patogênese do processo obstrutivo vascular causado por efeitos compressivos na cabeça do nervo óptico, visto que nenhum outro fator foi encontrado.

[Ultrastructure analysis and cytokines expression of orbital fibroblasts in the patients with thyroid-associated ophthalmopathy].

OBJECTIVE: To analyse the ultrastructure and cytokines expression from cultured orbital fibroblasts (OFs) in the patients with thyroid-associated ophthalmopathy (TAO). METHODS: Primary cultured OFs were obtained from 5 patients with TAO and 4 normal control subjects, some of subcultured OFs were treated by patients' serum with active TAO. Ultrastructures of OFs were observed by transmission election microscope. The cytokines in cultured supernatant were detected by enzyme linked immunosorbant assay (ELISA). RESULTS: There were no significant differences of ultrastructure of OFs from TAO patients and normal subjects. Nucleoli enlargement, microvillus prolongation and increase of endoplasmic reticular of OFs were detected after maintaining in culture. The IL-1, TNF-alpha and IFN-gamma were found in supernatant of OFs treated by patients' serum. IL-1 was found in supernatant of OFs in TAO patient and control subjects, and the IL-1 level of former was higher than the controls. CONCLUSION: There are no significant differences in ultrastructure of OFs from patients with TAO and normal subjects. The OFs treated with the serum of TAO patients showed proliferation and increasing cytokines secretion.

Morphological studies of the optic canal.

BACKGROUND: In some cases of closed head injuries after minor blunt trauma, an amaurosis can occur. Our knowledge concerning the pathophysiological mechanisms of traumatic optic neuropathy is limited. The aim of this study is to analyze the morphology of the optic canal in order to understand the effect of mechanical forces in the optic canal and the consecutive injuries. METHODS: Forty-one optic canals from body donors were analyzed by light microscopic, polarization microscopic, immunohistochemical and scanning electron microscopic techniques. RESULTS: In the optic canal, collagen fibrils of the dural sheath are organized in a scissor-like pattern. Within this collagen network multiple vessels are integrated. The main component of the extracellular matrix is collagen type I. The dural sheath and pial sheath are connected by collagen bundles. Parallel to these bundles, small vessels form anastomoses between the dural and pial vessel systems. In the arachnoidea, no blood vessels can be detected by immunohistochemical techniques. CONCLUSIONS: Based on morphological findings, the following pathophysiological mechanisms can be discussed in cases of blunt closed head injury with consecutive amaurosis: 1. Squeezing and rupture of nutritive vessels by transduction of shearing forces via the scissor-like collagen network. 2. Atrophy by pressure of the optic nerve after injury to the microvasculature followed by formation of microhematomas and reactive edema. 3. Direct injury of axons of the optic nerve by shearing forces within the optic canal. These mechanisms should be studied further in the future.

The cavernous body of the human efferent tear ducts: function in tear outflow mechanism.

PURPOSE: To determine the structure and function of a system of large blood vessels integrated in the bony canal between the orbit and the inferior nasal duct. METHODS: Thirty-one dissected lacrimal systems of adults were analyzed by using gross anatomy, histology, and electron microscopy as well as corrosion vascular casts. RESULTS: More than two thirds of the bony canal between orbit and inferior nasal duct is filled by a plexus of wide-lumened veins and arteries. The vascular system is embedded in the wall of the lacrimal sac and nasolacrimal duct and is connected to the cavernous tissue of the inferior turbinate. Three types of blood vessels can be distinguished inside the vascular tissue that surrounds the lumen of the lacrimal passage: barrier arteries, capacitance veins, and throttle veins. CONCLUSIONS: The surrounding vascular plexus of the lacrimal sac and nasolacrimal duct is comparable to a cavernous body. While regulating the blood flow, the specialized blood vessels permit opening and closing of the lumen of the lacrimal passage, effected by the bulging and subsiding of the cavernous body, and at the same time regulate tear outflow. Other functions such as drainage of absorbed tear fluid components and a role in immunologic response are under discussion as well. Malfunctions in the cavernous body may lead to disturbances in the tear outflow cycle, ocular congestion, or total occlusion of the lacrimal passages. Variations in the conditions for swelling of the cavernous tissue may have led to the (mistaken) description of valves in the lacrimal passage.

Hydroxyapatite orbital implant. A light- and electron-microscopic and immunohistochemical study.

OBJECTIVE: This study aimed to characterize the constituents of the ingrown host tissue in explanted orbital coral spheres by means of light electron microscopy and immunohistochemistry and to compare findings at different intervals after implantation. DESIGN AND METHODS: A microscopic retrospective laboratory study of three explanted coral spheres from three different patients was undertaken. The first specimen was an infected hydroxyapatite orbital implant, which was removed after 18.5 months and processed for standard light microscopy and transmission electron microscopy. Immunohistochemistry was performed using vimentin, actin, CD-68, and CD-34 marker. Two other explanted spheres (after 3 weeks and 2.5 months) were examined by light microscopy only, because no fibrovascular ingrowth could be detected. RESULTS: On light microscopy, the pores of the first coral were filled entirely with the fibrovascular tissue. A basophilic line reminiscent of calcium deposition was seen along hydroxyapatite spicules, where it often was associated with newly formed bony lamellae. Similar lines were seen partially in the 2.5-month specimen but not in the 3-week specimen. Immunohistochemistry of the first specimen enhanced visualization of the capillary network when the CD-34 marker was used. The fibrovascular tissue was uniformly vimentin-positive and partially actin-positive. On transmission electron microscopy, typical fibroblasts and myofibroblasts were observed. The latter were separated by thin sheets of banded collagen and formed pseudoepithelial structures. Proliferating vessels often showed high endothelial cells. CONCLUSIONS: The fibrovascular ingrowth contains not only vimentin-positive regular fibroblasts but also actin-positive myofibroblasts. Interaction between the invading tissue and hydroxyapatite structures leads to long-term ossification.

Scanning electron microscopy study of the tarsal and orbital conjunctival surfaces compared to peripheral corneal epithelium in pigmented rabbits.

The mammalian palpebral conjunctiva has not been systematically evaluated by scanning electron microscopy (SEM). The upper eyelid of female grey rabbits (2 kg) was fixed in its extended conformation at 15.00 h; some corneas were prepared with the same fixative protocol. The corneal epithelium, within 1 mm of the limbus, is a mosaic of small-to-large (average cell area of 693 m2) squamous cells with light, medium or dark appearance due to different densities of cell surface microplicae. The tarsal conjunctiva was a 1.5 to 3 mm wide mosaic of small (average cell area of 86 microm2) non-desquamating polygonal cells having distinctive light and dark appearances due surface microplicae. The orbital portion of the palpebral conjunctiva is also composed of small (average cell area of 87 microm2) non-desquamating polygonal cells but with a uniform medium-grey appearance due to a relatively consistent density of surface microvilli. Several types of intercellular pore-like openings were also present across the palpebral surface but not the corneal epithelial surface. Very small type 1 pores (1.5 to 5 microm diameter) were present at a density of 480 to 760 / mm2 for the tarsal and 80-160 / mm2 for orbital conjunctiva. Slightly larger (2.5 to 18 microm diameter) type 2 pores with distinct borders were present at 120-200 / mm2 across the orbital conjunctiva. Very large (10-109 microm diameter) type 3 (Henle) pores were present at 40 to 280/mm2 especially at the tarsal/orbital transition zone. Type 4 pores (goblet cell orifices) were oval with a peripheral ring of microvilli and were present at 40 to 160/mm2 for tarsal and 800 to 1600/mm2 for orbital conjunctiva. The rabbit palpebral conjunctival surface is thus distinctly different from the peripheral corneal epithelium across which it slides following eyelid closure.

Malignant fibrous histiocytoma of the lateral wall of the orbit.

A 58-year-old male presented with malignant fibrous histiocytoma originating from the lateral wall of the orbit, manifesting as left exophthalmos and diplopia on left lateral gaze. Magnetic resonance (MR) imaging demonstrated the tumor extending into the left orbit and under the temporalis muscle. The tumor was isointense with muscle on T1-weighted MR images and was surrounded by a low-intensity rim, which was proved to be the capsule after histological examination. The tumor was completely removed after detaching the lateral orbital rim and zygomatic arch using the dismasking flap method. He underwent one course of CYVADIC chemotherapy and has demonstrated no recurrence for 1 year and 6 months postoperatively.

Total integration of an ocular implant/prosthesis: preliminary in vivo study of a new design.

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.

Electron microscope investigation of polytene chromosomes in the Mediterranean fruit fly Ceratitis capitata.

Ultrastructural analyses of polytene chromosomes from male pupal orbital bristle cells and from larval salivary glands of Ceratitis capitata were carried out. It was shown that chromatin complexes corresponding to the X chromosome heterochromatic network are surrounded by material containing ribonucleoprotein (RNP) granules 250-300 A (1 A = 0.1 nm) in diameter. RNP granules of similar size surround the spherical Y chromosome. These data point out the presence of transcriptional activity in both of these chromosomes. The absence of clear structure in chromosomal regions situated between large bands in both types of tissues was observed. These results support the hypothesis of weak synapsis between chromatids or small chromomeres of polytene chromosomes in this species. In addition, we describe a specific puff revealed in both orbital trichogen cells and salivary glands that is morphologically similar to the 93D puff of Drosophila melanogaster.

Spontaneous intraorbital hematoma mimicking orbital neoplasm--case report.

A 66-year-old female presented with spontaneous intraorbital hematoma manifesting as left exophthalmos after left eye discomfort persisting for 5 months. She had no history of head injury. Computed tomography revealed a round mass in her left orbit which was slightly high density with no postcontrast enhancement. A blood cyst was extirpated through frontotemporal craniotomy. Histological findings showed no tumor or vascular anomaly. Spontaneous intraorbital hematoma with insidious symptoms is extremely rare and should be considered in the differential diagnosis of orbital mass lesions.

[The usage of light density heparin (fraxiparin) in the treatment of orbital phlegmonous cellulitis with orbital veins and thrombophlebitis of the cavernous sinus]. / Zastosowanie heparyny drobnoczasteczkowej (fraksiparyny) w leczeniu ropowicy oczodolu z zakrzepowym zapaleniem zyl oczodolowych i zatoki jamistej.

A case of 72 years old man, diabetic, suffering from phlegmonous cellulitis with orbital veins and sinus cavernous thrombophlebitis as a nasal vestibule furuncle complication is presented. Apart from the application of antibiotics and surgical procedure, the patient was treated from beginning with thrombolytics specimen, fraxiparine. The methods of treatment of cavernous sinus thrombosis with thrombolytic specimens evoke in the literature controversial opinions. In the author's opinion the early application of fraxiparine in presented case could be regarded as responsible for stopping the process orbital veins and sinus cavernous thrombosis and even causing it to recess. The complete cure without complications (e.g. blindness) is attributed by the authors to the anticoagulation treatment. The authors also stress that fraxiparine may by used for treatment of cavernous sinus thrombophlebitis even when the surgical procedure is planned.

Ultrastructure of cultured human orbital fibroblasts.

The fine structure of cultured human orbital fibroblasts was investigated by transmission electron microscopy. One culture was derived from a patient with severe Graves' ophthalmopathy, the other from a donor without inflammatory orbital disease. Despite their known differences in metabolism, orbital fibroblasts from either source revealed no ultrastructural differences. The cells had extensive thin cytoplasmic processes. The perinuclear areas contained multiple assemblies of Golgi membranes, modest amounts of rough endoplasmic reticulum, intermediate filaments, and lysosome-like structures. Glycogen deposits were noted both in the perinuclear cytoplasm and in the thin processes. These ultrastructural features of orbital fibroblasts are the same as those of fibroblasts from other anatomic regions.

Identification of orbital lymphatics: enzyme histochemical light microscopic and electron microscopic studies.

The presence of orbital lymphatics in the primate model is demonstrated using light and electron microscopic enzyme histochemistry. In addition, strictly morphological definitions of lymphatics, such as discontinuous basal lamina, thin and irregular walls, anchoring filaments, and attenuated endothelial cell cytoplasm, were applied. This study confirmed the presence of conjunctival lymphatics reported by others. It also clearly demonstrated the presence of orbital arachnoid and lacrimal gland lymphatics that have not been previously described. A few areas of the extraocular muscles and connective tissue at the orbital apex also showed evidence of the presence of lymphatic vessels. Additional work is needed to define the nature and extent of orbital lymphatics as well as their connection to the extraorbital lymphatic system.