Intercellular Structure Research Articles

Effects of terpenes and oleic acid as skin penetration enhancers towards 5-fluorouracil as assessed with time; permeation, partitioning and differential scanning calorimetry

Permeation of the model hydrophilic compound 5-fluorouracil was studied through human epidermal membranes treated with penetration enhancers oleic acid in propylene glycol, d-limonene, 1,8-cineole, menthone and nerolidol for times ranging from 1 to 12 h. Partitioning of the drug from aqueous solutions into enhancer treated human stratum corneum was also measured. Differential scanning calorimetry probed the mechanisms of action of these enhancers. All five substances increased the permeation of 5-fluorouracil, probably mainly by disrupting the intercellular lipid lamellar structure. The enhancement effects of d-limonene and oleic acid were saturable within 6 h, reaching a limiting value of about 3.6- and 24-fold increase in drug flux, respectively, whereas 1,8-cineole, menthone and nerolidol showed increasing effects with time leading to maximum enhancements of about 95-, 42- and 25-fold increase, respectively, after 12 h, probably related to improved drug partitioning. Lipid extraction was negligible.

Phthalocyanine mediated photodynamic thrombosis of experimental corneal neovascularization: effect of phthalocyanine dose and irradiation onset time on vascular occlusion rate.

The aim of this study was to evaluate the possible influence of phthalocyanine dose and of time interval between phthalocyanine injection and irradiation commencement on the rate of experimental corneal neovascularization photodynamic thrombosis in albino rabbits. New corneal vessels were irradiated with a diode laser (670 nm, 2 mW) after the intravenous injection of chloroaluminum sulfonated phthalocyanine. Different animals were irradiated either 5 min after the injection of different phthalocyanine doses (3, 6, 8, 12, or 14 mg/kg), or at different times (5 min, 24 h, or 58 h) after a standard phthalocyanine dose (3 mg/kg) injection. Irradiation time necessary for vascular occlusion was recorded. Decrease of phthalocyanine dose as well as delay of irradiation onset resulted in a statistically significant increase of irradiation time. Electron and light histological examination revealed platelet thrombi inside irradiated corneal new vessels. Damage in the vascular endothelial cell membrane and in intercellular contact structure was noted, leading to disorganization of the endothelial cells layer and death of most endothelial cells. These results indicate that both early commencement of irradiation after phthalocyanine injection and phthalocyanine dose increase accelerate the rate of phthalocyanine mediated corneal neovascularization photodynamic thrombosis. Thrombosis seems to result from photochemically induced vascular endothelial cell damage.

An ultrastructural study on HeLa cells cultured in roller bottles forming aggregates

We will describe here the ultrastructure of HeLa cells cultured in either roller bottles for 8 days or 10 days or in Petri dishes for 7 days. Junctional complexes could be seen between adjacent cells in aggregates formed in roller bottles. The junctional complexes were serially located especially near the free surface of the cells which occupied the outer layer of the aggregates. Two elements of the junctional complex, i.e., tight junctions and intermediate junctions, were observed between adjacent cells. The density and the diameter of microvilli in the intercellular space between cells cultured in roller bottles were denser and narrower than those of microvilli on the free surface of the cells. Junctional complexes and dense microvilli formed intercellular secretory canaliculus-like structure observed in the intercellular space of certain secretory glands.

Human cervical epidermal carcinoma-associated intracellular localization of glycosphingolipid with blood group A type 3 chain.

A monoclonal antibody, MRG‐1, was produced by immunizing a mouse with a human ovarian mucinous cyst adenocarcinoma‐derived cell line, RMUG‐L. By immunohistochemical staining, the antigen was found to be exclusively localized in the intracellular structures of the cells used as the antigen and of the epithelial cells in normal human cervical glands. However, although the antigen was predominantly detected in the plasma membrane and the intercellular structure of the middle layer of normal human cervical squamous epithelium (92%), it was also contained in the intracellular structure of cervical epidermal carcinoma at a high frequency (80%). The striking difference in the distribution of the MRG‐1 antigen between normal and cancerous tissues was found to be a cervical carcinoma‐associated phenomenon and a useful tumor marker for immunohistochemical examination. Since the antigen was found to be of a blood group A‐related nature by immunohistochemical staining of the tissues and to be a glycosphingolipid, it was purified from human erythrocytes of blood group A, and the structure was concluded to be GalNAcα1–3Gal(2–1αFuc)jβ1–3GalNAcα1–3Gal(2–1αFuc)‐ β1–4GlcNAcβ1–3Galβl‐4Glcβ1–1′Cer, blood group A type 3 chain‐containing glycosphingolipid, by NMR, negative ion FABMS and permethylation analysis. In the subcellular localization analysis of the antigen, type 3‐A glycosphingolipid antigen was detected in the Golgi body and the microsomes of RMUG‐L cells, and the distribution coincided with the finding by immunohistochemical staining. In addition, in cervical epidermal carcinoma, although the blood group A, mainly type 2‐A chain, was localized in the plasma membrane and the intercellular structure, the blood group A type 3 chain was selectively found in the perinuclear structure. Also, the blood group A type 3 chain in cervical dysplasia as well as that in normal cervix was predominant in the plasma membrane. Thus, the selective intracellular localization of blood group A type 3 chain was a phenomenon characteristic of cervical epidermal carcinoma and the carcinoma in situ.

Microstructure development in undercooled AlBe powders

The development of solidification microstructure in aluminum-rich AlBe alloy powders was studied as a function of melt undercooling, cooling rate, powder size and beryllium content. Auger electron spectroscopy indicates that BeO partially displaces Al 2O 3 from the powder surface. The BeOAl 2O 3 coating reduces the attainable undercooling at beryllium contents above about 4 at.% Be. Powders containing Al-9at.%Be when cooled at 0.5 °C s −1 contain facetted primary beryllium and a cellular aluminum matrix. Increasing the cooling rate to 25 °C s − reduces the extent of facetting of the primary beryllium phase, and at a cooling rate of 500 °C s −1 multiple primary beryllium dendrites are observed. In Al-4at.%Be powders cooled at 500 °C s −1, primary beryllium formation is avoided and solidification commences with a cellular aluminum and intercellular beryllium structure. The aluminum cells evolve to a dendritic network during recalescence. Following recalescence the dendritic aluminum and interdendritic beryllium structure is replaced by a coupled eutectic morphology which completes solidification. The microstructure development is analyzed in terms of the solidification pathways possible based on a skewed coupled eutectic growth zone and composite stable-metastable phase diagrams including a metastable liquid miscibility gap.

Characterization of 51Cr‐EDTA as a marker of duodenal mucosal permeability

Proximal duodenum was perfused with various solutions and mucosal permeability assessed by measuring the clearance of 51Cr labelled ethylenediaminetetra-acetate (EDTA) from blood-to-intestinal lumen in anaesthetized rats. Net flux of fluid was determined by measurement of effluent weight changes. Perfusion of duodenum with 50 mM NaCl significantly increased fluid absorption but had no effect on EDTA clearance. EDTA clearance was unaffected by perfusion with 400 mM or 800 mM mannitol. Perfusion with 400 mM NaCl induced a sustained fluid secretion and a small but irregular increase (40%) in EDTA clearance. A significant 3.6-fold increase in clearance was obtained in response to perfusion of duodenum with deionized water. Similarly, perfusion with either 20 mM HCl or 50 mM ethyleneglycol-bis-(beta-amino-ethylether)-N,N'-tetraacetic acid (EGTA) significantly increased the EDTA clearance 3.3-fold and 2-fold respectively. Perfusion with a hypotonic HCl-solution (10 mM HCl + 40 mM NaCl) increased fluid absorption and the EDTA clearance. It is concluded that no positive linear relationship exists between luminal osmolality and 51Cr-EDTA movement across the mucosa. It is postulated that high luminal acidity or extreme hypotonicity increase the EDTA clearance by widening of and/or disruption of intercellular junctional structure.

Intercellular structure in a many-celled magnetotactic prokaryote

A many-called magnetotactic prokaryote obtained from brackish water was observed to possess intercellular connections at points of contact between the outer membranes of constituent cells. Each aggregate organism consisted of 10 to 30 individual Gram-negative cells containing material with the appearance of poly-β-hydroxybutyrate and magnetosomes of unusual arrangement, structure and composition. The aggregate, which possessed prokaryotic-type flagella arranged at the outwards surfaces of each cell, showed motility indicative of co-ordination between individual component cells. These results suggest that this organism could be a multicellular prokaryote.

Surface oxides on melt spun ribbons of an AlLiBe alloy

The development of solidification microstructure in aluminum-rich AlBe alloy powders was studied as a function of melt undercooling, cooling rate, powder size and beryllium content. Auger electron spectroscopy indicates that BeO partially displaces Al2O3 from the powder surface. The BeOAl2O3 coating reduces the attainable undercooling at beryllium contents above about 4 at.% Be. Powders containing Al-9at.%Be when cooled at 0.5 °C s−1 contain facetted primary beryllium and a cellular aluminum matrix. Increasing the cooling rate to 25 °C s− reduces the extent of facetting of the primary beryllium phase, and at a cooling rate of 500 °C s−1 multiple primary beryllium dendrites are observed. In Al-4at.%Be powders cooled at 500 °C s−1, primary beryllium formation is avoided and solidification commences with a cellular aluminum and intercellular beryllium structure. The aluminum cells evolve to a dendritic network during recalescence. Following recalescence the dendritic aluminum and interdendritic beryllium structure is replaced by a coupled eutectic morphology which completes solidification. The microstructure development is analyzed in terms of the solidification pathways possible based on a skewed coupled eutectic growth zone and composite stable-metastable phase diagrams including a metastable liquid miscibility gap.

Effects of environmental salinity on intercellular organization and junctional structure of chloride cells in early stages of teleost development

AbstractMorphology of chloride cells was studied in embryos, larvae and juveniles of ayu (Plecoglossus altivelis), carp (Cyprinus carpio) and flounder (Kareius bicoloratus). Chloride cells of seawater‐adapted fishes interdigitated to neighboring cells and linked each other with leaky junctions. No such interdigitation or a leaky junction was found in those of freshwater fishes. Larval ayu were able to tolerate direct transfer from fresh water to seawater even immediately after hatching. Juvenile flounder reared in seawater for 60 days were able to adapt to fresh water. Their chloride cells started developing or degenerating interdigitations and leaky junctions within 3 h after the transfer. Juvenile ayu of landlocked form caught in Lake Biwa survived in seawater for no longer than 6 h. Juvenile carp died within 12 h after transfer to 15%. seawater. Newly hatched flounder did not survive in fresh water for longer than 48 h. Their chloride cells did not show any morphological change, although the epithelial cells were severely damaged. Thus, the ability of chloride cells to modify their intercellular organization and junctional structure appears to play a critical role in salinity adaptation.

An ultrastructural study of root invasion in three vascular wilt diseases

Transmission electron-microscopy was used to study root invasion in resistant and susceptible cultivars of tomato infected with Fusarium oxysporum f. sp. lycopersici or Verticillium albo-atrum and pea infected with F. oxysporum f. sp. pisi. There were many similarities in invasion by all pathogens of root epidermis and cortex in resistant and susceptible cultivars. Hyphae of tomato pathogens adhered to host root cell walls of susceptible cultivars but remained separated by extracellular electron-opaque material; hyphae of F. oxysporum f. sp. pisi on pea roots were embedded in a mucilaginous sheath. Both forms of adhesion were associated with a localized disruption of adjacent host wall structure. Initial penetration was by intercellular hyphae; subsequent intercellular colonization frequently resulted in the formation of wall appositions and papillae within epidermal and cortical cells. Penetration of host walls was achieved by constricted hyphae and localized wall degradation; continued deposition of material occurred around penetration hyphae with consequent formation of elongated penetration papillae. These were lignified, resistant to enzymic and chemical degradation and apparently effective in preventing further hyphal growth, although the frequency of their formation was similar in both resistant and susceptible cultivars. Papillae did not form in the moribund cells often seen even before penetration by F. oxysporum ff. sp.; in contrast V. albo-atrum was occasionally present within apparently healthy cells surrounded by invaginated host plasmalemma. A differential expression of varietal resistance occurred at the endodermis of both plant species. Accumulation of electron-opaque material in tomato endodermal cells and deposition of suberin and autofluorescent material in pea appeared to limit colonization of the stele. Pathogens circumvented this putative line of resistance either by intercellular growth between endodermal cells or by longitudinal growth from the root tip, which is devoid of mature endodermis. The diffuse and extensive intercellular wall structure of root tip cells is particularly amenable to initial colonization from which longitudinal growth allows entry into immature unlignified xylem elements and subsequently into mature vessels; hyphae were never seen to enter vessels from mature stelar cells.

Membrane alterations during cornification of mammalian squamous epithelia: A freeze‐fracture, tracer, and thin‐section study

Tight junctions (zonulae occludentes) create a pericellular barrier to the diffusion of large molecules in non-keratinizing mammalian epithelia. However, in cornifying epithelia such as the epidermis, the importance of tight-junctional elements versus secreted intercellular lipid for barrier function is uncertain. In an attempt to resolve this question, we compared membrane structure in the stratum granulosum and stratum corneum of epidermis, esophagus, and vagina of newborn and adult humans and mice under both normal and various experimental conditions. We incubated pieces of epidermis in organ culture and infused tissues with lanthanum or horseradish peroxidase in vivo and in vitro. All were processed for electron microscopy of freeze-fracture replicas or thin sections. Lanthanum seeped outward to the stratum granulosum in all tissues examined--further apical migration was halted by lamellar-body contents in skin. A similar pattern of intercellular lamellar lipid deposition and membrane structure occurred in all epithelia studied. Freeze-fracture replicas of these obstructive regions revealed occasional, incomplete junctional strands (particularly in moist epithelia) and abundant lamellar material, but complete zonulae occludentes were never encountered. A possible relationship between moisture and tight junction formation was further suggested by organ culture experiments during which brief incubations stimulated an increase in the number of junctional strands and diminished numbers of lamellar bodies. We conclude that, in the epithelia studied, the deposition of secreted lamellar body contents forms the barrier to water-soluble tracer loss: tight-junctional elements are either absent or too fragmentary to constitute an effective barrier.

EXTRASKELETAL OSTEOGENIC SARCOMA

The authors report a case of extraskeletal osteogenic sarcoma originating from the upper paravertebral region of a 40‐year‐old Japanese male. The patient was treated by a combination of surgery, radiotherapy. and chemotherapy and died with widespread pulmonary metastases and local recurrence after total illness of more than 10 years. This case appears to be a unique example of long survival, extraordinary primary site and apparently benign histologic features of the original mass. Electron microscopic study of this tumor revealed irregularly shaped tumor cells with poorly differentiated intracellular organella and eventual deposition of apatite crystals in the intercellular fibrous structure. The world literature on extraskeletal osteogenic sarcoma is reviewed.

Bronchoesophagology.

ELECTRON microscopy upon tissue obtained at the time of bronchoscopy demonstrated changes in the intercellular structure of the cell walls and membrane, particularly in patients with chronic bronchitis.¹The changes in bronchitis were those of degree only, and no absolute difference between normal bronchial mucosa and that of bronchitis could be demonstrated. Several observations were made on the bronchitic tissue, and the most marked was a great reduction in the amount of pellicular structure. Several other alterations of intercellular structure were less marked. Experimentally, in dogs anticancer drugs introduced intrabronchially in the tumor zone were absorbed into the local blood and lymphatic circulations, reducing the possibility of drug toxicity that occurs from systemic administration.²Since the high concentration in a cancer-containing bronchus may destroy fixed and free-floating malignant cells before, during, and after manipulation the use of chemotherapeutic agents through the bronchoscope may prove to be an adjunct

TRANSPLANTATION OF THE HEART; ALTERATIONS IN MORPHOLOGY OF HEART.

Histologic examination of the homografted heart at the time of "rejection" shows round cell infiltration, interstitial hemorrhage, edema, and necrosis.^1-3With the obvious histocompatibility of cardiac autografts one would not anticipate these specific alterations in histologic appearance. However, with electron microscopy we have demonstrated certain changes in intercellular structure after excision and reimplantation of the heart.⁴Neural elements are principally involved. Therefore, we have examined the morphology of normal canine hearts and hearts subjected to sham operation, autotransplantation, and homotransplantation. Using silver impregnation and trichrome counter stain we have attempted to evaluate the effect of these operations on neural and collagenous elements in the heart. <h3>Methods</h3> Studies were carried out on four groups of mongrel dogs: (1) three normal controls; (2) two animals subjected to sham operation, including thoracotomy, extracorporeal circulation, hypothermia, and cardiac arrest; (3) five orthotopic cardiac autotransplants; (4) two dogs subjected to cardiac homotransplantation. Autotransplantation

Electron Microscopic Studies on Ascites Hepatoma Islands of Rats: I. Micromorphological Changes in Intercellular Structure of the Hepatoma Cell “Island” in AH7974 during Trypsinization

Electron Microscopic Studies on Ascites Hepatoma Islands of Rats: I. Micromorphological Changes in Intercellular Structure of the Hepatoma Cell “Island” in AH7974 during Trypsinization

STUDIES ON LIVING CELLS OF PEA SEEDLINGS II. INTERCELLULAR TUBULAR MATTER

THE INTERCELLULAR substance in meristematic tissues of higher plants is commonly considered to be composed of calcium pectate. When unmodified by lignification, suberization, etc., it gives a more or less characteristic reaction with ruthenium red (Mangin, 1893). It is truly plastic and morphologically distinct from the cell wall (Kerr and Bailey, 1934; Bailey, 1954). Accordingly, when ordinary schizogenous intercellular spaces are developing, this substance supposedly lines their inner surfaces. However, it has now been found that in the growing regions of the stem, as well as the root, certain intercellular spaces contain a different, tubular intercellular structure. This is characteristically soluble in ethanol, and is therefore not formed of calcium pectate. Such tube-like structures appear to be extremely labile, and are destroyed by pressure, as well as by dehydrating and embedding agents. Consequently, they are not present in alcohol-dehydrated and paraffin-sectioned material. In a limited number of studies on living material this intercellular matter has evidently been observed in the past, but interpreted as air found inside the film of water lining the capillaries of the intercellular space and forming a black rim at the interface. The problem of distribution and appearance of gas in intercellular spaces, as well as the old controversy concerning the lining of them are beginning to be re-examined (Sifton, 1945, 1957) in the light of the recent experimental studies with living material. The differences in solubility of oxygen and carbon dioxide in water are held responsible for increased internal pressure during photosynthesisand corresponding increase in air space development (Dale, 1957). A waxy substance lining the spaces is suggested to account for the differences in the capillary rise of various liquids in dried strips of Dianthus leaves (Hausermann, 1944) , and the presence of a lipid pellicle in various parts of many plants is described by Scott,

Effect of intercellular and intracellular speech structure on attitude change and learning

Effect of intercellular and intracellular speech structure on attitude change and learning

The Serious Limitations and Erroneous Indications of Biopsy in the Diagnosis of Tumours of Bone

The essential evidence respecting a bone tumour is whether it is simple or malignant. The clinical history and condition of the patient at the first examination, though often of vital importance in diagnosis, may contribute little to elucidate the problem. Because of this and because the histology of normal tissues is characteristic, while pathology is associated with considerable change in the cellular and intercellular structure, we turned to histology for conclusive evidence. A widespread belief prevails in the infallibility of this evidence. Indeed, so firmly is this belief held that, if the subsequent history of the case differs from the forecast given, it is the pathologist, however eminent, who is blamed for the erroneous interpretation, rather than the vagaries of the histological material. Consequently, certain leading authorities hold that biopsy affords a means of “fully proving” the nature of bone tumours and always resort to biopsy prior to any major surgical measures, notwithstanding Ewing's advice that “few surgeons realise the limitations in the histological diagnosis of bone tumours and the conditions which simulate or accompany them.” An examination of the reports on the histology of bone tumours reveals the indecision which the appearances produce. For, whereas in the descriptions of normal tissues we see the use of definite terms, such as myxomatous, fibrous, cartilaginous, or osseous, in the description of pathological tissue we see the indecisive terms mucoid, fibroid, chondroid, osteoid, mucofibroid, fibrochondroid, chondrosteoid, etc., terms which permit of considerable latitude of expression by different observers. The medical student is usually taught his pathology, histology, and radiology from well established lesions and does not realise how closely simple and malignant lesions simulate one another in the early and, indeed, in some cases, in the late stages. Biopsy involves the risks of anaesthesia, surgical exploration, and all that it means in additional damage, dispersal of tumour cells, destruction of the scaffolding on which repair may be built up, etc., and the mental and physical pain associated with it—risks sometimes resulting in the death of the patient with a simple lesion, which could possibly be regarded as negligible or justifiable if the evidence so obtained were reliable. Consequently, as I have pointed out more fully elsewhere,1 we ought before biopsy to satisfy ourselves with the answers to several questions: (1) Can the findings of biopsy be relied upon? (2) How should the biopsy be performed—by needling, punch, or real exposure and inspection? (3) Does any form of biopsy permit us to watch sufficiently the evolution of a tumour to establish its nature? (4) Will biopsy enable us to get an early correct diagnosis?

The Serious Limitations and Erroneous Indications of Biopsy in the Diagnosis of Tumours of Bone

The essential evidence respecting a bone tumour is whether it is simple or malignant. The clinical history and condition of the patient at the first examination, though often of vital importance in diagnosis, may contribute little to elucidate the problem. Because of this and because the histology of normal tissues is characteristic, while pathology is associated with considerable change in the cellular and intercellular structure, we turned to histology for conclusive evidence. A widespread belief prevails in the infallibility of this evidence. Indeed, so firmly is this belief held that, if the subsequent history of the case differs from the forecast given, it is the pathologist, however eminent, who is blamed for the erroneous interpretation, rather than the vagaries of the histological material. Consequently, certain leading authorities hold that biopsy affords a means of “fully proving” the nature of bone tumours and always resort to biopsy prior to any major surgical measures, notwithstanding Ewing's...