Tympanosclerosis

1980 ◽  
Vol 89 (4_suppl) ◽  
pp. 1-16 ◽  
Author(s):  
Maurice Schiff ◽  
Antonio Catanzaro ◽  
Jacques F. Poliquin ◽  
Allen F. Ryan

Tympanosclerosis is a disease which affects the tympanic membrane (TM) and middle ear. The locus for the essential pathology is in the connective tissue component of the drum which is the lamina propria. In the middle ear, the pathology is in the basement membrane. In the early stages there is a minimal involvement of the mesenchymal component, usually seen as a small white macula, or scar, in the drum. In advanced disease, the hyalinization of the mesenchymal component together with the attraction of the calcium ion leads to a thick, dense, calcified scar. The theory of pathogenesis for this disease entity is that the connective tissue component of these structures is stimulated by infection, inflammation, or trauma involving some degree of local immunological hypersensitivity. With severe middle ear infection, the mucosa of the inner surface of the drum becomes permeable, and the ground substance of the lamina propria becomes edematous taking up water together with components of complement from the middle ear disease. The abnormal middle ear secretions contain the immunoglobulin components capable of participating in the process. If there is any damage to the connective tissue, the adsorption and repair permits the body to react immunologically against the destroyed tissue, thereby sensitizing this area. Experiments were performed with the guinea pig in which the tympanic membrane was removed and the lamina propria isolated and prepared as an immunological antigen. When this material was injected into the rabbits, a high, satisfactory antiguinea pig tympanic membrane antibody was formed (anti-GPTM). It was then possible to remove this anti-GPTM antibody from the serum. The tissue specificity was determined by immunofluorescent staining which showed it to be adsorbed onto the TM, middle ear mucosa, as well as the basement membrane of the respiratory tract. The guinea pigs which were passively sensitized with anti-GPTM antiserum demonstrated the binding of the antibodies on the tympanic membrane when subject to trauma, infection, or cautery. The manifestation was in the anatomical area related to the injury. Complement fixation was, likewise, demonstrated. Controlled animals which were not traumatized, or were not passively sensitized, included those which were injected with IgG from rabbits not sensitized against GPTM. They showed no fixation of antibody or complement in the TM. Following injury the antibody and complement bound to the TM provide the necessary elements for the subsequent immunopathologic disease entity known at tympanosclerosis.

1963 ◽  
Vol 117 (3) ◽  
pp. 339-348 ◽  
Author(s):  
G. B. Pierce ◽  
A. R. Midgley ◽  
J. Sri Ram

A parietal yolk sac carcinoma of the mouse that secretes large quantities of basement membrane-like material has been used to study the formation of basement membranes. Suitably characterized fluorescein-labeled antibodies against this material stained basement membranes of epithelial structures and vessels, as well as reticulin. When absorbed with reticulin and vascular basement membranes of the spleen until these structures no longer fluoresced, the antibody still stained the basement membrane-like material of the tumor, its normal embryonic counterpart (Reichert's membrane), and the basement membranes at the bases of epithelial cells. The observation made previously that parietal yolk sac cells secreted, in the absence of connective tissue and reticulin, the basement membrane (Reichert's membrane) upon which they rested has been confirmed through the localization of ferritin-labeled antibody to the endoplasmic reticulin of the secreting cells. Since a basement membrane proven to be an epithelial secretion is antigenically similar to basement membranes at the bases of all epithelial cells studied but antigenically different from connective tissue elements, it is postulated that the basement membranes at the bases of epithelial cells in general are an epithelial secretion, and are not a condensation of ground substance as is commonly believed.


Development ◽  
1988 ◽  
Vol 104 (3) ◽  
pp. 431-446 ◽  
Author(s):  
P.V. Senior ◽  
D.R. Critchley ◽  
F. Beck ◽  
R.A. Walker ◽  
J.M. Varley

In situ hybridization (ISH) and immunocytochemistry were used to localize sites of synthesis and deposition of the basement membrane glycoprotein laminin during development in the postimplantation mouse embryo and extraembryonic membranes. In addition, similar studies were performed on postnatal viscera during the first 20 days after birth. Up to 10 days post coitum, embryonic laminin synthesis was confined to parietal endoderm. In maternal tissue, intense laminin mRNA expression was detected in decidual cells in the mesometrial and antimesometrial endometrium at 5–7 days. At 10 days, uniform expression was still seen within the mesometrial endometrium, with higher levels around migrating trophoblast, but in the antimesometrial aspect expression was restricted to the basal zone. High levels of mRNA expression persisted in parietal endoderm throughout gestation but much lower levels were detected in visceral yolk sac. In the mature placenta, laminin mRNA expression was also found associated with fetal vessels in the labyrinth and giant cells at the fetal/maternal boundary. In the embryo, the external limiting membrane of the cerebral vesicles and spinal cord stained for laminin protein and detectable mRNA was found in the pia mater. Growing peripheral nerves and dorsal and ventral root fibres expressed laminin mRNA and stained for laminin protein. Laminin mRNA expression was found in ureteric buds and nephrogenic vesicles (but not in metanephric blastema) during early prenatal kidney development, and in glomeruli, Bowman's capsule, loops of Henle and collecting duct cells at later stages of development, and after birth. All these structures possessed laminin-rich basement membrane (BM). Laminin mRNA expression fell to below detectable levels in the kidney around weaning. In the gut, laminin expression and protein staining was confined to the muscularis externa and the lamina propria during embryogenesis. After birth, the muscularis externa, muscularis mucosa and lamina propria cells corresponding to fibroblasts had detectable laminin mRNA, but in adult gut no laminin mRNA could be demonstrated in any cell type. In liver, low levels of laminin mRNA were seen in the capsule and in periportal connective tissue. After birth, laminin mRNA was associated with intrahepatic bile channels; no laminin mRNA was detected in the parenchyma and protein deposition was restricted to blood sinus BM. In the adult liver, no laminin mRNA was detected in any cell type. The developing heart showed uniform expression of laminin mRNA from 12 days to before birth. Postnatally, labelling was restricted to connective tissue cells.


1980 ◽  
Vol 87 (1) ◽  
pp. 255-263 ◽  
Author(s):  
M Rojkind ◽  
Z Gatmaitan ◽  
S Mackensen ◽  
M A Giambrone ◽  
P Ponce ◽  
...  

A new procedure is introduced for the isolation of connective tissue fibers, called biomatrix, containing a significant portion of the extracellular matrix (basement membrane components and components of the ground substance). Biomatrix isolated from normal rat liver contains >90% of the tissue's collagens and all of the known collagen types, including types I and III and basement membrane collagens. The purified collagenous fibers are associated with noncollagenous acidic proteins (including fibronectins and possibly small amounts of glycosaminoglycans). Procedures are also described for preparing tissue culture substrates with these fibers by either smearing tissue culture dishes with frozen sections or by shredding the biomatrix into small fibrils with a homogenizer. The biomatrix as a substrate has a remarkable ability to sustain normal rat hepatocytes long-term in culture. The hepatocytes, which on tissue culture plastic or on type I collagen gels do not survive more than a few weeks, have been maintained for more than 5 mo in vitro when cultured on biomatrix. These cells cultured on rat liver biomatrix show increased attachment and survival efficiencies, long-term survival (months) and retention of some hepatocyte-specific functions.


1979 ◽  
Vol 27 (5) ◽  
pp. 881 ◽  
Author(s):  
AG Lyne ◽  
DE Hollis

Ovaries from the bandicoots I. macrourus and P. nasuta, collected during pregnancy and lactation, were examined macroscopically and with the light microscope. The mean number of corpora lutea (CL) was greater in I. macrourus (5.13) than in P. nasuta (3.31). This difference in ovulation rate was reflected in the mean number of embryos and the mean number of pouch young respectively (I. macrourus 4.05, 3.07; P. nasuta 2.63, 2.65). During the first few days of pregnancy, the transformation of follicle granulosa cells into luteal cells was accompanied by the intrusion of the theca, which produced a network of blood vessels and connective tissue. A conspicuous feature of the developing CL was the presence of pools of blood between the luteal cells. By 5-6 days of pregnancy, the CL was a fully formed structure, the central cavity having been filled in by hypertrophy of the luteal cells and an increase in the connective tissue which formed a central core. The luteal cells had almost reached their maximum size and they contained numerous lipid droplets. Mitoses of luteal cells were not evident at any stage in the formation of the CL or later, though some of the luteal cells had two or more nuclei. The structure of the CL and the diameter of the luteal cells and their nuclei remained almost constant until regression occurred after the 45th day of the 60-day lactation period. Regression of the CL was characterized by a marked reduction in the size of the luteal cells and their nuclei as well as an increase in the connective tissue component. Diameters and volumes of the CL were similar in the two species, reaching maxima during the second half of pregnancy and changing very little until the 45th day of lactation, after which they decreased rapidly. This decline occurred whether or not the animals subsequently ovulated during the last quarter of the lactation period.


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