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Purpose: Several graft materials are available for use in the treatment of urethral stricture disease. Placental membrane is being used in a variety of settings as a graft in wound healing and tissue repair. We aim to evaluate the effect of implanting decellularized human placental membrane into rabbit urethras., Methods: Dorsal onlay graft urethroplasty using prepared human placental membrane was performed in 10 New Zealand White rabbits (Oryctolagus cuniculus). After 3 months, the rabbits underwent cystourethroscopy to evaluate urethral patency. The rabbits were then euthanized and the urethras examined for pathological findings., Results: All urethroplasties were performed without complication. There were no observed episodes of urinary retention, infection, or renal failure. Urethral patency was achieved in all rabbits 3 months postoperatively. Urothelial replacement of the placental membrane graft was observed in all rabbits without malignant transformation., Conclusion: Dorsal onlay urethroplasty using decellularized human placental membrane can safely be performed in a rabbit model. This pilot study demonstrated urothelial replacement of human placental membrane in the rabbit urethra without stricture formation. Placental membrane is a promising biomaterial for urethral reconstruction.

Body membranes are thin sheets/layers of cells or tissues which cover the surface of internal organs, the outside of the body and lines various body cavities. These membranes are separated into two main groups which are epithelial membranes and connective tissue membranes. Decellularized forms of inner body membranes in the groups of epithelial membranes (amniotic membrane, mesentery, omentum, pericardium, peritoneum, pleura) and connective tissue membranes (fascia, periosteum, synovial membrane) have been used in tissue engineering studies for preparation and regeneration of various tissues such as bone, tendon, cartilage, skin, cornea, ocular surface, uterine, periodontium, vascular and cardiovascular structures. Decellularized inner body membranes have high biocompatibility and support cell attachment, cell growth and angiogenesis which are desired properties for using as versatile tools in tissue engineering applications. Even though, decellularized forms of these membranes have been used in many studies, it is necessary to develop new decellularization methods for more effective cell removal and less destructive properties on tissue structures. Moreover, development of decellularization agents which target removal of antigens of donor tissues is also essential because these antigens are one of the main reasons for tissue-organ rejections in allogeneic and xenogeneic tissue-organ implantations. This review provides comprehensive information and analysis about the current state of the art in the literature on decellularized inner body membranes and applications of these membranes in tissue engineering.

Purpose: Previous clinical studies have shown the effectiveness of bone repair using two-stage surgery called the induced membrane (IM) technique. The optimal wait before the second surgery is said to be 1 month. We have been successfully performing the IM technique while waiting an average of 6 months to carry out the second stage. We hypothesised that the IM maintains its beneficial capabilities, even at a later second stage, and that there is no relation between the speed of bone union and the wait between the first and second stage. We sought to explore the biological properties of 'older' IMs sampled to substantiate our clinical observations., Methods: Thirty-four patients with a critical size defect were treated with the IM technique. In seven of these patients, pieces of the IM were collected 4.2-14.7 months after the first surgery. IM-derived cell phenotype and osteogenic potential were investigated using in vitro studies (n = 4) while IM nature and function were investigated by histology and immunohistochemistry (n = 3)., Results: The median wait before the second surgery was 5.8 months [range 1.2-14.7] and bone healing occurred at 7.6 months [range 2.5-49.9] for 26 patients. IMs aged 4.2-14.7 months contained mesenchymal stromal cells with in vitro osteogenic potential and corresponded to a multipotent tissue with osteogenic and chondrogenic capabilities contributing to osteogenesis over time., Conclusion: This preliminary study suggests the IM retains its powerful osteogenic properties over time and that waiting longer between the two surgeries does not delay bone union.

Background: During fresh fruit consumption, sensory texture is one factor that affects the organoleptic qualities. Chemical components of plant cell walls, including pectin, cellulose, hemicellulose and lignin, play central roles in determining the textural qualities. To explore the genes and regulatory pathways involved in fresh citrus' perceived sensory texture, we performed mRNA-seq analyses of the segment membranes of two citrus cultivars, Shiranui and Kiyomi, with different organoleptic textures., Results: Segment membranes were sampled at two developmental stages of citrus fruit, the beginning and end of the expansion period. More than 3000 differentially expressed genes were identified. The gene ontology analysis revealed that more categories were significantly enriched in 'Shiranui' than in 'Kiyomi' at both developmental stages. In total, 108 significantly enriched pathways were obtained, with most belonging to metabolism. A detailed transcriptomic analysis revealed potential critical genes involved in the metabolism of cell wall structures, for example, GAUT4 in pectin synthesis, CESA1, 3 and 6, and SUS4 in cellulose synthesis, CSLC5, XXT1 and XXT2 in hemicellulose synthesis, and CSE in lignin synthesis. Low levels, or no expression, of genes involved in cellulose and hemicellulose, such as CESA4, CESA7, CESA8, IRX9 and IRX14, confirmed that secondary cell walls were negligible or absent in citrus segment membranes. A chemical component analysis of the segment membranes from mature fruit revealed that the pectin, cellulose and lignin contents, and the segment membrane's weight (% of segment) were greater in 'Kiyomi'., Conclusion: Organoleptic quality of citrus is easily overlooked. It is mainly determined by sensory texture perceived in citrus segment membrane properties. We performed mRNA-seq analyses of citrus segment membranes to explore the genes and regulatory pathways involved in fresh citrus' perceived sensory texture. Transcriptomic data showed high repeatability between two independent biological replicates. The expression levels of genes involved in cell wall structure metabolism, including pectin, cellulose, hemicellulose and lignin, were investigated. Meanwhile, chemical component contents of the segment membranes from mature fruit were analyzed. This study provided detailed transcriptional regulatory profiles of different organoleptic citrus qualities and integrated insights into the mechanisms affecting citrus' sensory texture.

Membrane-induced interactions can play a significant role in the spatial distribution of membrane-bound proteins. We develop a model that combines a continuum description of lipid bilayers with a discrete particle model of proteins to probe the emerging structure of the combined membrane-protein system. Our model takes into account the membrane's elastic behavior, the steric repulsion between proteins, and the quenching of membrane shape fluctuations due to the presence of the proteins. We employ coupled Langevin equations to describe the dynamics of the system. We show that coupling to the membrane induces an attractive interaction among proteins, which may contribute to the clustering of proteins in biological membranes. We investigate the lateral protein diffusion and find that it is reduced due to transient fluctuations in membrane shape.

Waterjet cutting technology is considered a promising technology to be used for minimally invasive removal of interface tissue surrounding aseptically loose hip prostheses. The goal of this study was to investigate the feasibility of waterjet cutting of interface tissue membrane. Waterjets with 0.2 mm and 0.6 mm diameter, a stand-off distance of 5 mm, and a traverse speed of 0.5 mm/s were used to cut interface tissue samples in half. The water flow through the nozzle was controlled by means of a valve. By changing the flow, the resulting waterjet pressure was regulated. Tissue sample thickness and the required waterjet pressures were measured. Mean thickness of the samples tested within the 0.2 mm nozzle group was 2.3 mm (SD 0.7 mm) and within the 0.6 mm nozzle group 2.6 mm (SD 0.9 mm). The required waterjet pressure to cut samples was between 10 and 12 MPa for the 0.2 mm nozzle and between 5 and 10 MPa for the 0.6 mm nozzle. Cutting bone or bone cement requires about 3 times higher waterjet pressure (30-50 MPa, depending on used nozzle diameter) and therefore we consider waterjet cutting as a safe technique to be used for minimally invasive interface tissue removal., (Copyright © 2015 IPEM. Published by Elsevier Ltd. All rights reserved.)

Several members of the SLC26 gene family have highly-restricted expression patterns in the auditory and vestibular periphery and mutations in mice of at least two of these (SLC26A4 and SLC26A5) lead to deficits in hearing and/or balance. A previous report pointed to SLC26A7 as a candidate gene important for cochlear function. In the present study, inner ears were assayed by immunostaining for Slc26a7 in neonatal and adult mice. Slc26a7 was detected in the basolateral membrane of Reissner's membrane epithelial cells but not neighboring cells, with an onset of expression at P5; gene knockout resulted in the absence of protein expression in Reissner's membrane. Whole-cell patch clamp recordings revealed anion currents and conductances that were elevated for NO3- over Cl- and inhibited by I- and NPPB. Elevated NO3- currents were absent in Slc26a7 knockout mice. There were, however, no major changes to hearing (auditory brainstem response) of knockout mice during early adult life under constitutive and noise exposure conditions. The lack of Slc26a7 protein expression found in the wild-type vestibular labyrinth was consistent with the observation of normal balance. We conclude that SLC26A7 participates in Cl- transport in Reissner's membrane epithelial cells, but that either other anion pathways, such as ClC-2, possibly substitute satisfactorily under the conditions tested or that Cl- conductance in these cells is not critical to cochlear function. The involvement of SLC26A7 in cellular pH regulation in other epithelial cells leaves open the possibility that SLC26A7 is needed in Reissner's membrane cells during local perturbations of pH.

Ca(2+) is a key player in an astonishing variety of plant signal transduction pathways where transient, spiking or oscillatory changes in cytosolic Ca(2+) levels help to couple environmental or developmental cues to appropriate cellular responses. Understanding whether and how much Ca(2+) signaling contributes to defining stimulus-response specificity has long been a challenge, but recent work has provided strong evidence that specific information can indeed be encoded in the spatiotemporal characteristics of Ca(2+) signals. Identification of the Ca(2+) binding proteins that transduce Ca(2+) signals by regulating downstream effector proteins has revealed a complex network of Ca(2+) sensor families, of which some members show distinct patterns of expression and subcellular localization. By utilizing genetically encoded fluorescent Ca(2+) probes to monitor Ca(2+) changes at high spatiotemporal resolution, it is now possible to explore whether such spatial heterogeneities in Ca(2+) sensor distribution are coordinated with subcellular microdomains of Ca(2+) signaling. Such visualization of Ca(2+) signaling will also help to address which cellular compartments and transporters contribute to mobilizing and sequestering Ca(2+) and thus define stimulus-specific Ca(2+) signatures., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

This article, which forms part of the life sciences series, examines cellular organisation in the formation of body tissues, membranes, organs and systems. Four main types of body tissue are described: epithelial, connective, muscle and nervous tissue. Each class of tissue is described in terms of its structure and function. Where appropriate, subgroups within the classifications are identified. Different membranes in the body are considered and the organisation of tissues and membranes into more complex structures, such as organs and body systems, is outlined.

Objective: To explore surface roughness of bone cement and surround tissue on histological characteristic of induced membranes., Methods: Bone cements with smooth and rough surface were implanted in radius bone defect, intramuscular and subcutaneous sites of rabbits, and formed induced membranes. Membranes were obtained and stained (HE) 6 weeks later. Images of membrane tissue were obtained and analyzed with an automated image analysis system. Five histological parameters of membranes were measured with thickness,area,cell density,ECM density and microvessel density. Double factor variance analysis was used to evaluate the effect of the two factors on histological characteristics of induced membranes., Results: Membranes can be induced by each kind of bone cement and at all the three tissue sites. In histological parameters of thickness,area and micro vessel,there were significant differences among the membranes induced at different tissue sites (P = 0.000, P = 0.000, P = 0.000); whereas, there were no significant differences in histological parameters of cell density and ECM density (P = 0.734, P = 0.638). In all five histological parameters of membranes, there were no significant differences between the membranes induced by bone cements with different surface roughness (P = 0.506, P = 0.185, P = 0.883, P = 0.093, P = 0.918)., Conclusion: Surround tissue rather than surface roughness of bone cements can affect the histological characteristics of induced membranes. The fibrocystic number, vascularity, mechanical tension and micro motion of the surround tissue may be closely correlated with the histological characteristics of induced membranes.

The neural retinal leucine zipper (Nrl) knockout mouse is a widely used model to study cone photoreceptor development, physiology, and molecular biology in the absence of rods. In the Nrl(-/-) retina, rods are converted into functional cone-like cells. The Nrl(-/-) retina is characterized by large undulations of the outer nuclear layer (ONL) commonly known as rosettes. Here we explore the mechanism of rosette development in the Nrl(-/-) retina. We report that rosettes first appear at postnatal day (P)8, and that the structure of nascent rosettes is morphologically distinct from what is seen in the adult retina. The lumen of these nascent rosettes contains a population of aberrant cells protruding into the subretinal space that induce infolding of the ONL. Morphologically adult rosettes do not contain any cell bodies and are first detected at P15. The cells found in nascent rosettes are photoreceptors in origin but lack inner and outer segments. We show that the adherens junctions between photoreceptors and Müller glia which comprise the retinal outer limiting membrane (OLM) are not uniformly formed in the Nrl(-/-) retina and thus allow protrusion of a population of developing photoreceptors into the subretinal space where their maturation becomes delayed. These data suggest that the rosettes of the Nrl(-/-) retina arise due to defects in the OLM and delayed maturation of a subset of photoreceptors, and that rods may play an important role in the proper formation of the OLM.

We investigated a change in tissue fluid osmolality and developmental sequences of mitochondria-rich (MR) cells during embryonic and larval stages of Mozambique tilapia, Oreochromis mossambicus, developing in freshwater. Tissue osmolality, representing body fluid osmolality, ranged from 300 to 370 mOsm/kg during embryonic and larval stages. This suggests that tilapia embryos and larvae are also able to regulate body fluid osmolality to some extent, although the levels are somewhat higher and fluctuate more greatly in embryos and larvae than in adults. Na(+)/K(+)-ATPase-immunoreactive MR cells were first detected in the yolk-sac membrane 3 days before hatching (day -3), followed by their appearance in the body skin on day -2. Subsequently, MR cells in both the yolk-sac membrane and body skin increased in number, and most densely observed on days -1 and 0. Whereas yolk-sac and skin MR cells decreased after hatching, MR cells in turn started developing in the gills after hatching. Thus, the principal site for MR cell distribution shifted from the yolk-sac membrane and body skin during embryonic stages to the gills during larval stages, and tilapia could maintain continuously their ion balance through those MR cells during early life stages.

Objective: The aim of this study was to evaluate the histologic changes in the maxillary sinus membrane after sinus membrane elevation and the simultaneous insertion of dental implants without additional grafting material., Study Design: In 6 mongrel dogs, bilateral edentulated flat alveolar ridges were created in the maxilla. After 3 months of healing, an implant was unilaterally placed in the maxillary sinus in such a way that it protruded 5 mm into the maxillary sinus after sinus membrane elevation. On the opposite side, the maxillary sinus was left untreated as a control site. The animals were killed 6 months after surgery. The maxillary sinus mucosa was examined using light microscopy and scanning and transmission electronic microscopy., Results: There were no morphologic or ultrastructural differences in the sinus membrane between groups., Conclusion: The results indicate that the surgical procedure by which implants are inserted into the sinus cavity by elevating the sinus membrane without adding any graft material appears to have little influence on the histologic characteristics of the sinus membrane.

The objective of this work was to study the chemical and physical characterization of eggshell and eggshell membrane particles prepared from the hen eggshell waste. Under the characterization measurements investigated, it was found that the pore structures of the two biomaterials belong to a typical Type II, indicating that they should be basically characteristic of nonporous materials or materials with macropores or open voids. Further, the chemical composition of the resulting eggshell particle was strongly associated with the presence of carbonate minerals from the Fourier transform infrared (FTIR) spectra. In contrast to the resulting eggshell membrane particle, the presence of functional groups of amines and amides was observable because of its chemical composition of fibrous proteins. From the isotherm data of methylene blue at 25 degrees C, the Freundlich model yielded a somewhat better fit than the Langmuir model. The adsorption isotherms revealed the eggshell biosorbents could only uptake the basic dye of less than 1.0mg/g in aqueous medium, which was attributed to their poor pore properties.

Term human fetal membranes express prorenin, a key enzyme within the renin-angiotensin system. High levels of another vasoactive peptide, endothelin-1 (ET-1), are found in human amniotic fluid. To address the question of the relationship between these two vasoactive systems, we analyzed the expression of the components of the ET-1 system in fetal membranes in which cell types had been identified using different markers. Immunohistochemistry was performed with antibodies raised against the human proteins of the ET system. Term fetal membranes displayed ubiquitous labeling of endothelin-converting enzyme-1 (ECE-1) and ET-1. ETA receptors were detected in the chorionic connective tissue and the attached decidua; ETB receptors were localized to chorionic trophoblast cells and decidua. The localization of the ET-1 receptor subtype was confirmed by in-situ receptor binding. Renin immunoreactivity was detected in the chorionic connective tissue and the decidua. These findings suggest that ET-1 is produced ubiquitously in human fetal membranes, and its targets may be, trophoblast cells following ETB receptor activation, vascular structures and fibroblasts in the connective tissue and decidua via ETA and ETB receptors. It appears possible that renin and ET may contribute to the pathophysiological changes associated with premature labor and preeclampsia.

Two previous studies from our laboratory have indicated that the ventral glial limitans subjacent to the hypothalamic supraoptic nucleus (SON-VGL) undergoes a reversible thinning upon chronic activation of the magnocellular neuroendocrine cells (MNCs) of the supraoptic nucleus (SON). Numerous other studies have shown that MNC somata hypertrophy with activation. One aim of the current study was to understand better how SON-VGL thinning occurs. A second aim was to quantify overall changes of the MNC somata region due to cellular hypertrophy to compare relative changes in dimensions. Here, we undertook a light microscopic stereological investigation of the SON and the subjacent SON-VGL of Nissl stained material under basal and activated conditions. Astrocyte numbers in the underlying SON-VGL remained stable across hydration state as did the overall volume of the SON-VGL and dendritic zone reference area. How these data are consistent with our earlier observations of SON-VGL thinning was resolved by the finding of a highly significant, 30% increase in the mediolateral dimension of the SON-VGL in dehydrated rats. These observations fit well with previous work from our laboratory that demonstrates a reorientation of SON-VGL astrocytes, from vertical to horizontal, which occurs in the activated SON-VGL. We found a significant, approximately 54%, increase in the overall volume of the MNC region of the SON. No significant rostrocaudal lengthening of the SON was detected, although a trend was evident. All the observed changes reversed with rehydration. These data indicate that elasticity of the SON-VGL acts to accommodate the volume expansion of the MNCs and enables the SON-VGL to continue as an interface between the underlying cerebrospinal fluid in the subarachnoid space and the expanded SON above.

Tritium-labeled selective agonist of non-opioid beta-endorphin receptor, the decapeptide immunorphine ([3H]SLTCLVKGFY) with specific activity of 24 Ci/mmol has been prepared. By its use, non-opioid beta-endorphin receptors were revealed and characterized on mouse peritoneal macrophages and rat myocardium, spleen, adrenal, and brain membranes. The non-opioid beta-endorphin receptor of macrophages has in addition to immunorphine (Kd of the [3H]immunorphine-receptor complex was 2.4 +/- 0.1 nM) and beta-endorphin (Ki of the [3H]immunorphine specific binding was 2.9 +/- 0.2 nM) a high affinity for Fc-fragment of human IgG1, pentarphine (VKGFY), cyclopentarphine [cyclo(VKGFY)], and [Pro3]pentarphine (VKPFY) (Ki values were 0.0060 +/- 0.0004, 2.7 +/- 0.2, 2.6 +/- 0.2, and 2.8 +/- 0.2 nM, respectively) and is insensitive to naloxone and [Met5]enkephalin (Ki > 100 microM). Treatment of macrophages with trypsin resulted in the loss of their ability for the specific binding of [3H]immunorphine. Values of the specific binding of 8.4 nM [3H]immunorphine to rat adrenal, spleen, myocardium, and brain membranes were determined to be 1146.0 +/- 44.7, 698.6 +/- 28.1, 279.1 +/- 15.4, and 172.2 +/- 1.8 fmol/mg protein, respectively. Unlabeled beta-endorphin, pentarphine, [Pro3]pentarphine, cyclopentarphine, cyclodipentarphine [cyclo(VKGFYVKGFY)], and Fc-fragment of IgG1 inhibited the binding of [3H]immunorphine to membranes from these organs. No specific binding of [3H]immunorphine to rat liver, lung, kidney, and intestine membranes was found.

Several 1-aryl-4-(2-arylethyl)piperazine derivatives were synthesized and tested in-vitro for their binding affinity for 5-HT(7) and 5-HT(1A) receptors. These compounds displayed 5-HT(7 )receptor affinity ranging between K(i) = 474 nM and K(i) = 8.2 nM, besides high affinity for the 5-HT(1A) receptor. Intrinsic activity of the most potent compounds was assessed. 4-[2-(3-Methoxyphenyl)ethyl]-1-(2-methoxyphenyl)piperazine (16) and 1-(1,2-benzisoxazol-3-yl)-4-[2-(3-methoxyphenyl)ethyl]piperazine (20) (K(i) = 24.5 and 8.2 nM, respectively) behaved as partial agonist and full agonist, respectively, when tested for 5-HT(7) receptor-mediated relaxation of substance P-induced guinea-pig ileum contraction.

Although there have been many studies on the round window membrane (RWM), little information has been reported about changes in the membrane associated with aging. We have undertaken morphological studies of RWMs using young (7-8 weeks old) and aged (27-29 months old) C57BL/6 mice. The RWM was thinner in mice from the aged group compared with that of the young group. The cell density in the epithelial and inner layers was also reduced in the aged group. In the middle layer of the RWM in aged mice, transmission electron microscopy revealed many degenerated short and thick elastic fibers. Confocal laser microscopy using fluorescein isothiocyanate(FITC)-wheat germ agglutinin (WGA) staining was used to identify WGA-positive fibers in the middle layer of the RWM, which changed in a similar manner to the fibers in aging skin.

The spatial distribution of intermolecular forces governs macromolecular interactions. The atomic force microscope, a relatively new tool for investigating interaction forces between nanometer-scale objects, can be used to produce spatially resolved maps of the surface or material properties of a sample; these include charge density, adhesion and stiffness, as well as the force required to break specific ligand-receptor bonds. Maps such as these will provide fundamental insights into biological structure and will become an important tool for characterizing technologically important biological systems.

A protein of 66 kd immunoreactive to anti-tyrosine phosphatase (PTP1C) antibodies coeluted with, and so may be associated with, somatostatin receptors (ssts) from rat pancreatic membranes. Also, anti-PTP1C antibodies immunoprecipitated functional ssts from pancreatic membranes, suggesting a PTP1C protein can associate with ssts at the membrane level. Somatostatin analog RC 160 had good affinity for sst2,3 and sst5 (IC50 = 0.2, 0.1, and 21 nmol/L) and low affinity for sst1 and sst4 (IC50 = 200 and 620 nmol/L), and induced rapid dose-dependent stimulation of PTP activity (maximal at 1 nmol/L and half maximal at 5 pmol/L) in NIH3T3 and CHO cells expressing sst2, with similar results for sst1, but no stimulation with sst3,4 or sst5. Treatment of cells expressing sst2 with RC 160 for 24 hours inhibited serum- or growth factor-induced cell proliferation dose-dependently (maximal at 1 nmol/L, half maximal at 6 to 53 pmol/L RC 160). In cells expressing sst1, weak inhibition of fibroblast growth factor 2-induced NIH3T3 cell proliferation was provoked by somatostatin analogs (> 10 nmol/L). The good correlation between inhibition of somatostatin binding, stimulation of PTP activity, and inhibition of cell proliferation implicates a PTP in growth inhibition mediated by sst2 and sst1.

The chloride cells of the gill secretory epithelium of fish that make the transition from fresh water to sea water adapt to the increased salinity by responding to a rapid signal that stimulates chloride secretion. In this paper, data are presented supporting the view that the transient increase in plasma osmolarity that can be measured during the transition is responsible for the stimulation of chloride secretion. A maximal increase of 65 mOsm in the plasma of Fundulus heteroclitus (the killifish) was found during acclimation to sea water. Similar or greater increases of osmolarity induced by mannitol on the basolateral side of isolated opercular epithelial membranes of the same species of fish containing great numbers of chloride cells produced stimulation of chloride secretion detected as the short circuit current. The shrinkage of the chloride cell activates the Na-K-2Cl cotransporter, and the Na/H exchanger and requires the integrity of apical chloride channels and normal levels of Ca. A Cl/HCO3 exchanger did not participate in this osmotic response to higher salinity. Chloride cell volume responses to osmolarity were studied with imagine and quantitative optics.

Study Design: Cranial and spinal dura from nine Sprague Dawley male rats were examined immunocytochemically for the presence of nerve fibers and mast cells and for innervation. The posterior longitudinal ligament and peridural membrane were also examined for these elements., Objective: To examine the pattern of sensory innervation and the presence of mast cells in rat spinal dura., Summary of Background Data: The cranial dura is richly innervated and has a robust population of mast cells, which have been implicated in the pathogenesis of vascular headache. Moskowitz's explanation for vascular headache focused on the dura mater and neurogenic inflammation. Essential to his model are dural trigeminovascular fibers and mast cells. Previous studies provide contradictory and inconclusive results regarding spinal dural innervation., Methods: Immunocytochemical techniques using antibodies to calcitonin gene-related peptide and substance P were used to identify sensory nerve fibers and antibodies to serotonin were used to identify mast cells. Specimens dissected included dura of the cranial vault in continuity with the dorsal cervical dura, dura of the skull base in continuity with the ventral cervical dura, lumbar dura, and posterior longitudinal ligament from the cervical and lumbar regions., Results: A rich neural network and an abundant mast cell population were identified in the supratentorial and infratentorial cranial dura, both dorsally and ventrally. A paucity of nerve fibers and mast cells was observed in the cervical and lumbar dura; in contrast, these elements were prominent in the posterior longitudinal ligament and peridural membrane., Conclusions: Spinal dura does not have a rich innervation of calcitonin gene-related peptide- and substance P-positive nerve fibers or a robust population of mast cells. The spinal dura may serve as a protective covering. Unlike the cranial dura, it may not be implicated in the pathogenesis of pain. Additional studies on primate and human spinal dura are warranted to corroborate findings that the spinal dura may be relatively insensitive.

To gain insight into the tissue reactions leading to non-infectious loosening 25 autopsy specimens of femurs with well-fixed cemented femoral components of hip prostheses were analysed histomorphologically and morphometrically. The implant duration ranged from one month to 15 years. With the exception of some focal bone-cement contacts bone and cement were separated by a fibrohistiocytic soft tissue membrane. This membrane contained wear particles predominantly of the bone cement mantle and--less abundant--of the polyethylene cups. The amount of wear particles as well as histiocytes and necroses within the membrane statistically significantly increased with advancing time in situ. The cancellous bone adjacent to the soft tissue membrane often revealed a mainly histiocytic infiltration too, accompanied by bone remodeling in this area. The histiocytic inflammatory reaction at the bone cement interface, which is mainly caused by the accumulation of wear particles is considered to be of major importance for the non infectious late loosening of cemented prostheses.

The effects of two taurine and homotaurine derivatives (Ca N-acetyltaurinate: ATACa and Ca N-acetylhomotaurinate: AOTACa) were studied on the ionic transfer through a membranous model: the human isolated amniotic membrane. The ionic transfer was evaluated by measurements of the various components (cellular and paracellular) of the total conductance across the membrane. AOTACa influenced all the components of the total ionic conductance without flux ratio modifications and the general action scheme was a biphasic effect: decrease conductance with low concentrations and increase conductance with high concentrations. This effect might be important in the case of lower or higher supplementation. ATACa only interfered with some conductance components and this action was predominantly monophasic (decreased or increased conductance). This study indicates differential actions between two closely related molecules on a membranous model.

To gain an insight into the tissue reactions leading to noninfectious loosening, 25 autopsy specimens of acetabula with well-fixed cemented sockets were analyzed histomorphologically and morphometrically. The mean duration of the implant was 7 (0.2-16) years. With the exception of some focal direct bone-cement contacts, bone and cement were separated by a soft tissue membrane which increased in thickness with increasing duration of the implant. Necroses in the membrane were also commoner with advancing implant time. The soft tissue membranes developed increasingly dense infiltrates of histiocytes, mainly containing wear particles of the bone cement and--though less abundant--polyethylene. The cancellous bone adjacent to the soft tissue membrane showed an increasing histiocytic infiltration with an increasing duration of the implant. The trabecular bone showed remodeling with formation of a neocortical layer parallel to the border of the cement mantle.

The transitional region of the eighth cranial nerve, where the central and peripheral nervous tissues are contiguous, was studied by electron microscopy using surgically resected specimens of the human eighth cranial nerve root. The astrocytic glial dome was sharply demarcated by a basement membrane from the peripheral portion of the nerve. Half-desmosomes were found on the edge of the astrocytic glial dome and at the luminal surface of the perivascular glial limiting membrane. Desmosomes and gap junctions were found between the astrocytic processes. These ultrastructural features suggest a weak link between the central and peripheral portions of the nerve which might predispose the transitional region to injury, although the peripheral and central portions have sufficient resistance to external stresses independently.

To overcome the technical difficulties encountered in investigating the physiology of Reissner's membrane (RM), primary culture of RM was established. Minute explants obtained by mechanical dissociation were seeded on impermeable substrate coated with collagen type I in serum-free, hormone-supplemented medium. Within 2 weeks, a large cultured area was obtained which reproduced the two cell layers of the original explant. One layer, deep or superficial depending on the side to which the explant adhered, was made of cells exhibiting light and electron microscopy characteristics of an epithelium. Immunohistochemical methods revealed that they expressed cytokeratin, demonstrating their epithelial nature. The second layer was made of mesenchymal cells. This study suggests that cell culture of RM will facilitate further investigation of its physiology.

In three patients a mechanically well-fixed Mathys Ceros 80 (Ha) hydroxyapatite-coated acetabular component was revised 2, 5 and 13 months after total hip replacement due to component malposition. In each case there was a thin cellular connective tissue membrane between hydroxyapatite and bone, the main cell type being fibroblast with only occasional giant cells. Immunohistological analysis revealed some MHC locus II antigen positive cells that were identified as monocytes. No interleukin-2 receptor positive cells were found. Under clinical cyclic loading conditions there does not seem to be chemical fixation or bony ingrowth into the hydroxyapatite coated prosthesis component. In human lymphocyte cultures, hydroxyapatite (Interpore 200, particle diameters 15-40 microns) did not cause an increase in lymphocyte DNA synthesis as assessed by the 3H-thymidine incorporation method on culture days 1, 3 and 5. As analysed with lymphocyte activation markers, the hydroxyapatite-dependent expression of MHC locus II antigen was modest and differed significantly (P less than 0.05) from that in culture medium only on day 3. Hydroxyapatite induced only a slight interleukin-2 receptor expression that did not differ from culture medium on days 1, 3 and 5. CD4 and CD8 positive lymphocytes as well as monocytes were not seen attached to hydroxyapatite particles during the culture days. Our findings suggest that hydroxyapatite is an immunologically inert implant material.

Fourteen mature New Zealand white female rabbits were allocated into two groups. Group 1 received a bolus doughy Simplex polymethylmethacrylate (PMMA) cement injected into the proximal tibia through a drill hole. Group 2 received an equal volume of particulate PMMA cement powder. The operated but nonimplanted left tibiae served as controls. The animals were killed after four months. The membrane surrounding the implant area was harvested aseptically and grown in tissue culture. The supernatants were assayed for prostaglandin E2 (PGE2) via radioimmunoassay. Bulk cement specimens produced on average 12.39 +/- 4.11 ng PGE2 on the right experimental side and 12.29 +/- 3.56 ng PGE2 on the left control side (not statistically different). Cement powder specimens produced 8.82 +/- 1.64 ng PGE2 on the right experimental side, which was statistically different from 4.21 +/- 0.88 ng PGE2 produced on the left control side. The ratio of PGE2 values for the right divided by the left side and the arithmetic difference between right and left sides were significantly higher in the particle group compared with the bulk group. Small, undigestable cement particles may be phagocytosed by foreign-body giant cells and histiocytes and then extruded into the extracellular compartment, along with substances such as PGE2. PGE2 has been implicated as the biologic mechanism for stimulating the bone lysis associated with prosthetic loosening.

Sections of seven human epiretinal membranes of diverse pathologic origin were labeled with antibodies to cellular retinaldehyde binding protein (CRALBP) and two intermediate filament proteins: glial fibrillary acidic protein (GFAP) and vimentin. All of the membranes studied contained heterogeneous cell populations that exhibited diverse morphologic characteristics. Double labeling with both anti-GFAP and anti-CRALBP positively identified one of the cellular components in these membranes as Müller's glia. In addition, other epiretinal cells exhibited immunolabeling patterns consistent with those found in fibrous astrocytes and retinal pigment epithelial (RPE) cells normally. The results demonstrate that a double-labeling method using CRALBP antibodies, in combination with antibodies to other appropriate antigens, can be used to distinguish between the different epiretinal cell types.

Secretory immunoglobulin A (SIgA) on the surface of the membranous epithelial cell (M cell) is present in Peyer's patches, an important element of gut-associated lymphoid tissue (GALT). Little information about this immunoglobulin exists except for its scantiness inferred from electron microscopic examination of the relatively thin layer of glycocalyx on the cell surface. This study was undertaken to investigate SIgA on the M cell surface by immunohistochemical observations of specimens from 16-week-old rabbits, using anti-IgA antibody specifically directed to alpha-chain and anti-SIgA antibody specific to both alpha-chain and secretory component (SC). Areas of strongly positive reaction with these antibodies were demonstrable by electron, as well as light microscopy in the glycocalyx layer and on microfolds of M cells, contrasting with the glycocalyx layer and microvilli of the adjacent absorptive cells. The findings were suggestive of an abundant presence of SIgA in the glycocalyx layer and on microfolds of M cells. The results suggested the participation of SIgA on M cell surfaces through a mechanism in which M cells take up intestinal antigens, although the precise role of SIgA on M cells remains unclear.

Thick (25-30 mu) sections of the fresh human, rabbit and rat liver were dismembered by vibrating in saline and the connective-tissue honeycomb-pannicular formations (HPF) were revealed. While being devoid of hepatocytes they correspond to the surface of the cross section of the lobule in a number of cases both by the form and by the size. Silver impregnation stains the HPF in yellow and the argirophilic fibres in black. Under natural conditions hepatocytes are disposed on the HPF with the wide basal side forming a one-cell-high layer with its total body and the free opposite apical surface.

We have derived a cell line from an epiretinal membrane excised surgically from a premature female infant born at a gestational age of 25 weeks, and who developed stage 5 retinopathy of prematurity. The cell line, which in early passages appeared immunocytochemically to contain cells with both neuronal and glial characteristics, has been maintained in culture for 14 months at the time this manuscript was submitted, and has survived 20 passages. The cells have a diploid, human karyotype, with most cells possessing 46 normal appearing chromosomes, including 44 autosomes and two X-chromosomes. Morphologically, the cell line at early passages consisted of polygonal cells and also of cells possessing long, spindly branching processes. These two cell types were cloned. Nearly 100% of the cells of both morphologic types in mixed cultures stained immunocytochemically for neuron-specific enolase (NSE), a neuronal marker, and approximately 5-10% of the cells in mixed cultures (including about 50% of the cells with the spindly morphology, that were less prevalent in mixed cultures) stained for glial fibrillary acid protein (GFAP), a glial marker. We have not performed "double-label" immunocytochemistry, but it was evident from the proportion of cells that stained with each marker that many cells must contain both GFAP and NSE. At least 50% of the cells in most of the early cultures were positive for keratin, while all were (and remain) negative for muscle actin. No cells are found that are immunocytochemically positive for factor VIII, a vascular endothelial cell marker. These cultured cells have also been studied immunocytochemically for their production of extracellular matrix substances. The cultures are immunocytochemically positive for type IV (but not type I) collagen, laminin and fibronectin. In later passages, cells of both clones lost their immunocytochemical positivity for GFAP and NSE, and all became positive for keratin. Cells of both clones also developed a similar, polygonal morphology, lacking long processes. By electron microscopy, many of the cells were seen to possess nonmotile cilia, with a 9 + 0 pattern of microtubule doublets. This cell line may be useful for studies of human retinal cell development and metabolism, and responses to pathological processes.

Certain structures which indicate probable involvement of a filamentous phase in life cycle of M. leprae have been noted in preserved skin biopsy suspensions from lepromatous leprosy cases. These include (i) filaments with empty or pink round spaces within them (ii) conidia-like structures and (iii) membranes with acid fast bacilli. These structures were rare in the fresh material.

The frequencies of cell degeneration and mitosis were investigated in the rupturing buccopharyngeal membrane (BPM) and in the persistent first branchial membrane (BM). In the BPM, cell degeneration starts many hours before rupture is visible, but mitotic figures are absent. In the BM this situation is reversed: mitotic figures are regularly observed, but a degenerating cell only occasionally. It is concluded that the ratio between the numbers of degenerating and dividing cells regulates the fate of both the BPM and the BM.

The human organ of Corti was investigated with the freeze fracturing technique with the purpose of analysing membrane specializations. Tight junctions were found on hair cells as well as on supporting cells. Inner and outer hair cells were coupled to the supporting cells by rather extensive tight junctions. The tight junctions between the Deiter's cells were comparable to those of the hair cells, while the tight junctions between the Hensen's cells were considerably less extensive. Gap junctions were present coupling all supporting elements in the organ of Corti, small ones preferably in the apical regions of the cells and large ones in the basal region.

The biological characteristics of Spirulina are reported in this study. The cellular structure and photosynthetic membrane structure of Spirulina (Cyanoschizophyta) were viewed by electron microscopy after freeze-etching. Special characteristics of the alga, its ecological behavior in natural carbonated water and its energetic behaviou in the laboratory cultures are also reported.

We injected varying numbers of retinal Muller glia into the rabbit vitreous in an established model of traction retinal detachment. We used indirect ophthalmoscopy to observe the changes elicited during the following 1 month. Although the severity of the tractional changes increased with increasing numbers of the glial cells, the pathology produced stabilized within the 1st week of injury. Muller glia were less effective at eliciting retinal detachments than retinal pigment epithelial cells (RPE) or mixtures of glia and RPE. Intravitreal tissue membranes derived from the glia differed morphologically from those derived from RPE. The glial membranes had fewer fibroblast-like cells, synthesized less extracellular matrix, and showed lower intravitreal cell proliferation, as determined by 3H-thymidine radioautography. Our findings indicate that membranes composed only of Muller glial cells promote less severe retinal pathology than those membranes composed of RPE or mixed cell types.

Clinical and electron microscopic studies of an idiopathic epiretinal membrane that was nonvascularized and progressive showed three types of cells: (1) predominant, fibrocyte-like cells; (2) macrophage-like cells; and (3) glial cells. Most of the abundant collagen showed characteristics of normal vitreous fibrils, although thicker collagen fibrils were also present. These ultrastructural findings, when compared with previously reported features of simple and secondary epiretinal membranes, suggest that clinically complicated epiretinal membranes are composed of more than one cell type, whereas simple epiretinal membranes consist only of glial cells. The fibrocyte-like and macrophage-like cells seen in our case were interpreted as being hyalocytes, rather than being derived from glial or retinal pigment epithelial cells. We support this interpretation by the ultrastructural features of the cells, the presence of abundant normal vitreous collagen, the biologic characteristics of hyalocytes as described by other investigators, and the absence of the ultrastructural features of glial or retinal pigment epithelial cells.

The glass-membrane-like capsules probably are the practically most important part of the separating membranes that typically form on intraocular lens implants in the human eye. With time in the eye, these clear capsules become tougher, more firmly adherent, and less eosinophilic. Their formation occurs early after implantation and is associated with the reactions of intraocular macrophages. Examples of well developed capsules are presented to show that only few cells are needed for their maintenance and that they can be of irregular thickness. Cell life on the film-like capsules is demonstrated using the examples of blood-eating macrophages, epitheliod cells, and melanocytes. Attachment of fibrous structures containing zonular fibers to the haptics is recorded.

Cells with protoplasmic pigment granules on the surface of intraocular lens implants can be divided by their basic nature into histiocytes, epitheloid cells, giant cells, small fibroblast-like cells, iris melanocytes, pigment epithelium, and probably corneal endothelium. All these cells are part of a cellular membranes that have been observed on lens implants at times between eight months and three and a half years after lens implantation.