Distribution of estrogen and progesterone receptors and steroid-regulated gene products in the chick oviduct

The distribution of estrogen and progesterone receptors (ER and PR, respectively) was studied immunohistochemically in the chick oviduct. Estrogen receptor immunoreactivity was found only in the nuclei of glandular epithelial cells. Progesterone receptor was found in the nuclei of glandular and luminal epithelia, stroma, smooth muscle cells and in the mesothelium. The dissimilar distribution of ER and PR suggests that either ER concentration in the luminal epithelium and smooth muscle is very low (below the sensitivity of ER immunostaining) or that estrogens control their PR synthesis indirectly via ER in glandular cells. A known estrogen-inducible protein, ovalbumin, was localized in the same glandular epithelial cells as ER. A progestin-inducible protein, avidin, was found in part of the luminal and glandular epithelium cells but not in other PR-positive cell types. This indicates the importance of cellular differentiation in the regulation of avidin synthesis. Estrogen and progesterone administration had effects also on ER and PR immunoreactivity. Estrogen and progesterone administrations for 24 h decreased markedly the immunoreactivity of their receptors. The decrease in receptor immunoreactivity is most likely due to a transient loss of immunoreactive receptor protein, since the antibodies (H222, PR6) react both with transformed (4 S) and non-transformed (8 S) receptor forms. At the subcellular level, PR was localized in the chromatin by immunoelectron microscopy. Progestin administration seemed to decrease PR immunoreactivity especially in the heterochromatin area, suggesting that conformational chromatin rearrangements occur during down-regulation of PR.

Expression of two types of receptor for insulinlike growth factors in human colonic epithelium

The presence of receptors for insulinlike growth factor I and II in human colonic epithelium is demonstrated. Scatchard analysis of binding data obtained with 125I-insulinlike growth factor I showed an insulinlike growth factor I receptor with a dissociation constant of 8.6 nM and a binding capacity of 0.8 pmol/mg membrane protein. Distinct insulinlike growth factor II receptors labeled with 125I-insulinlike growth factor II were also found with a dissociation constant of 6.9 nM and a binding capacity of 4.7 pmol/mg membrane protein. Two sets of observations make it possible to discriminate between the two types of insulinlike growth factor receptors. (a) Unlabeled insulinlike growth factor I was 3 times more potent than insulinlike growth factor II in inhibiting [125I] insulinlike growth factor I binding. Conversely, unlabeled insulinlike growth factor II was 10 times more potent than insulinlike growth factor I in competing with 125I-insulinlike growth factor II for binding to membranes. Insulin and proinsulin did not compete with either of the tracers. (b) Affinity labeling of membranes followed by sodium dodecylsulfate polyacrylamide gel electrophoresis under reducing conditions, revealed a radio-ligand-receptor complex of molecular weight 130,000 and 250,000 using 125I-insulinlike growth factor I and 125I-insulinlike growth factor II, respectively. These observations indicate that adult human colonic epithelium is abundantly equipped with two sets of receptors that recognize preferentially either insulinlike growth factor I or insulinlike growth factor II.

The fine structure and elemental analysis of keratinized epithelium of the filiform papillae analysis on the dorsal tongue in the American alligator (Alligator mississippiensis)

The filiform papillae of subadult alligator (120 cm-260 cm total length) tongues are examined by scanning electron microscopy and electron microprobe analysis. The filiform papillae form cone-like structures and are observed over the entire dorsal surface of a relatively long tongue with a round tip. The filiform papillae are composed of four layers; outer, upper intermediate, lower intermediate, and basal layer. The keratinized epithelial cells are analysed by the sulphur (S), and nitrogen (N) content levels. The S content is higher than that of N. In the anterior side of the filiform papillae, this content is lower than that in the posteriors. The S content is highest of all at about 2 microns in depth from the surface. These results suggest that the use of S concentration measurements may serve to be an effective tool for a simple, offhand evaluation of keratinization.

The neutrophil and chronic allergic inflammation. Immunochemical localization of neutrophil elastase

To test whether neutrophils infiltrate and degranulate in areas of chronic respiratory allergic inflammation, we developed an indirect immunofluorescence technique to localize neutrophil elastase in formalin-fixed, paraffin-embedded tissues. The affinity-purified antielastase stained only neutrophils on peripheral blood buffy coat smears, and in lung tissue from patients with pneumonia. We examined tissue specimens from four patients with fatal asthma, 10 patients with chronic sinusitis, and 10 patients with nasal polyposis for the presence of elastase, as well as eosinophil granule major basic protein (MBP). Neutrophil infiltration and extracellular elastase deposition in association with damage to respiratory epithelium were generally sparse in most specimens; the exceptions were one patient with asthma, one patient with chronic sinusitis, and two patients with nasal polyposis. In contrast, eosinophil infiltration and extracellular MBP deposition were generally marked in most specimens; the exceptions were one patient with asthma and one patient with nasal polyps where extracellular MBP deposition did not coincide with damage to respiratory epithelium. The results suggest that the neutrophil does not usually infiltrate tissues showing allergic inflammation; however, on occasion, it may participate in these inflammatory reactions.

Monoclonal antibody HML-1, a marker for intraepithelial T cells and lymphomas derived thereof, also recognizes hairy cell leukemia and some B-cell lymphomas

Current views regard monoclonal antibody HML-1 as an exquisite marker for intraepithelial T cells and primary intestinal and cutaneous T-cell lymphomas. We show that HML-1 reacted with 11 of 12 cases of hairy cell leukemia, with 1 of 13 cases of primary gastrointestinal B-cell lymphoma, and with an unclassified large-cell B lymphoma of the thoracic wall. We conclude that HML-1 is not restricted to the T-cell lineage and that the HML-1 antigen is expressed in a small subset of both T- and B-cell neoplasms.

Flow cytometric DNA analysis of corneal epithelium

We have modified an existing technique in order to perform DNA analysis by flow cytometry (FCM) of corneal epithelium from the mouse, rat, chicken, rabbit, and human. This protocol permitted an investigation of human corneal scrapings from several categories: normal, aphakic bullous keratopathy (ABK), keratoconus (KC), Fuch's dystrophy, edema, epithelial dysplasia, and lipid degeneration. No abnormal characteristic cell-kinetic profile was detected when averaged DNA histograms were compared statistically between the normal and either ABK, KC, edema, or Fuch's dystrophy groups. Abnormal DNA histograms were recorded for cell samples that were taken 1) from three individuals who had epithelial dysplasia and 2) from one individual diagnosed with lipid degeneration. The former condition was characterized by histograms that had a subpopulation of cells with an aneuploid amount of DNA or had higher than normal percentages of cells in the S and G2 + M phases of the cell cycle. Corneal cells from the patient who had lipid degeneration had an abnormally high percentage of cells in the G2 + M phases of the cell cycle. The availability of accurate DNA flow cytometric analysis of corneal epithelium allows further studies on this issue from both experimental and clinical situations.

Ultrastructural and immunohistochemical study of epithelioid hemangioendothelioma of bone: coexpression of epithelial and endothelial markers

Four cases of epithelioid hemangioendothelioma of bone--a borderline malignant tumor of vascular origin--were studied ultrastructurally and immunohistochemically. The epithelioid tumor cells were positive for vimentin, polyclonal and monoclonal cytokeratins, and the endothelial markers factor VIII-related antigen (FVIII:RAg) and Ulex europaeus agglutinin I. The coexpression of polyclonal cytokeratin and FVIII:RAg was demonstrated by means of step sections in the same tumor cells. The endothelial origin of epithelioid tumor cells was supported ultrastructurally by identification of Weibel-Palade bodies.

Localization of interleukin-1 in human cholesteatoma

Recent studies by other investigators have shown that interleukin-1 (IL-1) promotes bone resorption by stimulating various cells. Interleukin-1 not only stimulates collagenase production by fibroblasts and macrophages, but also acts as an osteoclast-activating factor. In this study, IL-1 was localized in human cholesteatoma tissues using both immunoperoxidase and immunofluorescent-staining methods with specific monoclonal antibodies. Highly concentrated IL-1 was found in the epithelial layer and granulation tissue. More specifically, intense staining was seen in basal and spinous cells of the epithelial layer, and in fibroblasts and macrophages of the granulation layer. We also located IL-1 in the normal external ear canal skin; however, the intensity of the staining in the cholesteatoma epithelium was found to be stronger. The presence of IL-1 in the epithelial layer and granulation tissue of the cholesteatoma suggests that IL-1 from the stimulated keratinocytes of the cholesteatoma could be one factor responsible for the markedly increased bone resorption observed in cholesteatoma patients.

N-terminal amino acid sequence, immunohistochemical localization and tissue distribution of a plasma membrane protein (Prot17) of rat enterocytes

Prot17, a protein of the basolateral membrane of rat small intestine with a mol.wt. of 17 kDa, can be isolated using a previously described method (Schiechl 1988). It occurs in the membrane as an oligomer with a mol.wt. of 90 kDa. In the present study a polyclonal antibody specific for Prot17 was used to explore by immunohistochemical techniques the tissue distribution of Prot17 and its ultrastructural localization within the cells. Furthermore the amino acid sequence of the N-terminal part of this molecule up to position 17 could be analyzed. The results are summarized as follows: Prot17 is a membrane anchored protein. Its partial amino acid sequence suggests that it is neither identical nor related to other known proteins. Immunofluorescence studies revealed, that it occurs only in epithelial cells. It is mainly found in the absorptive and goblet cells of the intestine and the acinar cells of the pancreas. Smaller quantities are found also in the bile duct epithelium of the liver, in the proximal tubule cells of the kidney and in the cells of the respiratory epithelium. Ultrastructural localization of Prot17 was possible in the intestinal epithelium and pancreas acinar cells. In both cell types it was found in the basolateral and microvillous membrane. In pancreas, Prot17 was also detected in the membrane of the zymogen granules. In the absorptive cells of the intestine Prot17 was found in both the membrane and the contents of subluminal vesicles. Furthermore, in apical granules of secretory cells of the respiratory epithelium binding of Prot17 specific antibody was found in the granular content, the membrane being negative.

Allele frequencies and segregation of human polymorphic keratins K4 and K5

Two electrophoretic variants for each of the human keratins K4 and K5 that are expressed in squamous nonkeratinizing epithelia lining the upper digestive tract could be distinguished on SDS-PAGE. Based on a sampling size of 1,299 unrelated individuals, calculation of allele frequencies showed the alleles to be in Hardy-Weinberg equilibrium. The genetic basis of this variation was confirmed by both quantitative gene dosage dependence and the transmission of the variants as Mendelian traits in two families. Thus the human keratin genes K4 and K5 are polymorphic, and each presents with two codominant alleles (a and b).

Ultrastructures of the epithelial basement membrane and the subepithelial capillaries in rabbit palatine tonsils

The ultrastructure of both the epithelial basement membrane and the subepithelial capillaries in rabbit tonsils was investigated using light and transmission electron microscopy of sections, and scanning electron microscopy of alkali-water macerated tissues. The basement membrane of the crypt epithelium was seen to consist of the lamina lucida, lamina densa and lamina fibroreticularis. The lamina fibroreticularis is made up of both fine and thick collagen fibrils. The basement membrane possesses numerous pores (0.5-20 microns in diameter) through which free cells migrate. The basement membrane overlying the follicle protrudes hemispherically towards the crypt lumen, while that over the interfollicular area forms many papillary projections. The capillaries are surrounded by collagen fibrillar sheaths invariably located below the collagen fibrillar sheet of the epithelial basement membrane. The capillaries immediately below the crypt epithelium, including switch-back loops of capillaries in the papillae, are fenestrated sinusoids (20-40 microns in diameter). Plasma cells, lymphocytes and macrophages are numerously gathered around the capillaries. Possible functional relations between these free cells and the fenestrated sinusoids are discussed.

Characterization of guinea pig tracheal epithelial cells maintained in biphasic organotypic culture: cellular composition and biochemical analysis of released glycoconjugates

An air-liquid interface (biphasic) primary culture system in which guinea pig tracheal epithelial cells maintain morphologic characteristics of differentiated epithelium has been developed in this laboratory. In this report, we compared quantitatively cell populations of 8-day cultures to those of epithelial mucosa in intact trachea. In addition, high molecular weight glycoconjugates released by the cultured cells were isolated and characterized. Quantitative morphometric analysis revealed similar volume densities of ciliated, secretory, basal, and "other" cells in cultures and in intact tracheal surface epithelium, although the cultures tended to have smaller cells and contained fewer basal cells. High molecular weight glycoconjugates released apically by cell cultures and excluded from Sepharose CL-4B columns contained approximately 5% hyaluronic acid but undetectable amounts of other proteoglycans, such as chondroitin sulfate, heparan sulfate, and dermatan sulfate. The hyaluronidase-resistant glycoconjugates exhibited a peak buoyant density at 1.49 g/ml on cesium chloride density gradient centrifugation and were shown to contain mucin-type carbohydrate to peptide linkages (i.e., GalNAc to ser/thr) and an amino acid composition typical of respiratory mucins. The results indicate that this organotypic cell culture system mimics quite closely morphology of mucosal epithelium in intact airways and that the cells release high molecular weight glycoconjugates with biochemical properties of mucin-type glycoproteins. Thus, this in vitro system appears well-suited for studies of mucin secretion and other functions of respiratory epithelial cells.

Micro-quantitation of lens myo-inositol by anion exchange chromatography

A method capable of the determination of pmole quantities of myo-inositol in mgr amounts of tissue by anion exchange chromatography is detailed for use in lens and potentially other tissues. Samples were rendered protein-free through ZnSO4/Ba(OH)2 precipitation, lyophilized and reconstituted in water just prior to analysis. An aliquot of sample was injected onto an anion exchange column and eluted with a 0.045 M sodium hydroxide mobile phase. Each analysis requires 30 minutes to complete. Average recovery of myoinositol added to lens sample prior to injection was 100.6%. The coefficient of variation for repeated sample injections was 2.9%. Rabbit lens averaged 11.4 mumol/gr wet weight with epithelium containing 8.5 mumol/gr wet weight while human lens contained 20.1 mumol/gr wet weight and human epithelial cells had 17.5 nmol/mgr protein.

Origin and colocalization of CGRP- and SP-reactive nerves in cat airway epithelium

A combination of neuroanatomic techniques was used to examine the origin and neuropeptide content of nerve fibers in the airway epithelium of adult cats. By the use of immunocytochemical methods, the peptides substance P (SP) and calcitonin gene-related peptide (CGRP) were colocalized in airway epithelial nerve fibers. Two days after wheat germ agglutinin (WGA) was injected into the nodose ganglion, fibers containing WGA immunoreactivity (IR) were detected in the airway epithelium. SP-like immunoreactivity (LI) and CGRP-LI were demonstrated separately in the WGA-IR fibers, establishing their origin from nerve cell bodies of nodose ganglion. Vagal transection inferior to the nodose ganglion reduced the number of SP- and CGRP-IR fibers by greater than 90% in ipsilateral airways. In contralateral airways, SP-IR fibers were substantially reduced, whereas the effect on CGRP-IR fibers was not statistically significant. Vagotomy superior to the nodose ganglion did not alter the density of peptide-IR fibers. The results prove that SP- and CGRP-IR nerve fibers of cat airway epithelium originate from nerve cell bodies in the nodose ganglion and that SP- and CGRP-like peptides may be stored together in some nerve fibers of the airway epithelium.

Identification of a membrane-cytoskeletal complex containing the cell adhesion molecule uvomorulin (E-cadherin), ankyrin, and fodrin in Madin-Darby canine kidney epithelial cells

Cell-cell contact is an important determinant in the formation of functionally distinct plasma membrane domains during the development of epithelial cell polarity. In cultures of Madin-Darby canine kidney (MDCK) epithelial cells, cell-cell contact induces the assembly and accumulation of the Na+,K+-ATPase and elements of the membrane-cytoskeleton (ankyrin and fodrin) at the regions of cell-cell contact. Epithelial cell-cell contact appears to be regulated by the cell adhesion molecule uvomorulin (E-cadherin) which also becomes localized at the lateral plasma membrane of polarized cells. We have sought to determine whether the colocalization of these proteins reflects direct molecular interactions which may play roles in coordinating cell-cell contact and the assembly of the basal-lateral domain of the plasma membrane. Recently, we identified a complex of proteins containing the Na+,K+-ATPase, ankyrin, and fodrin in extracts of whole MDCK cells (Nelson, W.J., and R. W. Hammerton. 1989. J. Cell Biol. 108:893-902). We have now examined cell extracts for protein complexes containing the cell adhesion molecule uvomorulin. Proteins were solubilized from whole MDCK cells and fractionated in sucrose gradients. The sedimentation profile of solubilized uvomorulin is well separated from the majority of cell surface proteins, suggesting that uvomorulin occurs in a protein complex. A distinct portion of uvomorulin (30%) cosediments with ankyrin and fodrin (approximately 10.5S). Further fractionation of cosedimenting proteins in nondenaturing polyacrylamide gels reveals a discrete band of proteins that binds antibodies specific for uvomorulin, Na+,K+-ATPase, ankyrin, and fodrin. Significantly, ankyrin and fodrin, but not Na+K+-ATPase, coimmunoprecipitate in a complex with uvomorulin using uvomorulin antibodies. This result indicates that separate complexes exist containing ankyrin and fodrin with either uvomorulin or Na+,K+-ATPase. These results are discussed in the context of the possible roles of uvomorulin-induced cell-cell contact in the assembly of the membrane-cytoskeleton and associated membrane proteins (e.g., Na+,K+-ATPase) at the contact zone and in the development of cell polarity.

Whole-mount preparations of mouse lens epithelium for the fluorescent cytological study of actin

A technique is given for the preparation of a sheet of epithelial cells from the capsule of the crystalline lens. A new method is described for fixation and staining with fluorescent phalloidin or actin antibody in order to localize the actin cytoskeleton in this tissue. Optical section of the preparation resolves such actin features as apical polygonal arrays, sequestered actin bundles, perinuclear actin aggregates, observed here for the first time, and filamentous networks in the basal region of the cell. This method is superior to previous ones in its ability to preserve actin-abundant sectors distinctively.

cDNA cloning of a novel cell adhesion protein expressed in human squamous carcinoma cells

A novel protein (SQM1 protein) present in human squamous epithelial cells has been found to be involved in cell adhesion in squamous epithelial cells, endothelial cells and extracellular matrix proteins. The corresponding cDNA that encodes a 135-residue polypeptide has been isolated. Sequence analysis indicates that the encoded polypeptide is distinct yet related to the beta subunit of integrins. A new sequence motif consisting of a heptadic repeat of positively-charged residues present in the polypeptide has been identified and is proposed to be important in protein-protein interaction. These results suggest that SQM1 protein, a new cell adhesion molecule expressed in squamous epithelial cells, may play an important role in tumor metastasis.

Immunohistochemical study of a rat membrane protein which induces a selective potassium permeation: its localization in the apical membrane portion of epithelial cells

We previously reported a novel rat membrane protein that exhibits a voltage-dependent potassium channel activity on the basis of molecular cloning combined with an electrophysiological assay. This protein, termed IsK protein, is small and different from the conventional potassium channel proteins but induces selective permeation of potassium ions on its expression in Xenopus oocytes. In this investigation, we examined cellular localization of rat IsK protein by preparing three different types of antibody that specifically reacts with a distinct part of rat IsK protein. Immunohistochemical analysis using these antibody preparations demonstrated that rat IsK protein is confined to the apical membrane portion of epithelial cells in the proximal tubule of the kidney, the submandibular duct and the uterine endometrium. The observed tissue distribution of rat IsK protein was consistent with that of the IsK protein mRNA determined by blot hybridization analysis. In epithelial cells, the sodium, potassium-ATPase pump in the basolateral membrane generates a sodium gradient across the epithelial cell and allows sodium ions to enter the cell through the apical membrane. Thus, taking into account the cellular localization of the IsK protein, together with its electrophysiological properties, we discussed a possible function of the IsK protein, namely that this protein is involved in potassium permeation in the apical membrane of epithelial cells through the depolarizing effect of sodium entry.

Histochemical localization of hyaluronate in human oral epithelium using a specific hyaluronate-binding probe

Biochemical data suggest that gingival epithelium contains hyaluronate, but there is little histochemical information about its localization. Hyaluronate was here visualized in gingival and buccal mucosa using a specific probe derived from the hyaluronate binding region of cartilage proteoglycan. Hyaluronate was found both in the gingival and buccal epithelium, but its localization was correlated with the type of keratinization. In the keratinized epithelium of gingiva, whether ortho- or parakeratotic, the intercellular spaces from basal to upper spinous layers displayed strong staining, most intense in the middle spinous cell layer. The uppermost vital cell layers as well as the cornified cell layer remained unstained. In the non-keratinized epithelium of buccal mucosa and the local non-keratinized areas of gingiva, only the basal cells and the lowermost spinous cell layers stained for hyaluronate, whereas the majority of the upper epithelium was negative. Electron microscopic examination of the basal and spinous cell layers displayed hyaluronate, both associated with the cell surface and free in the intercellular space. The subepithelial connective tissue showed positive but diffuse staining in all specimens.

Immunohistochemical localization of sex hormone-binding globulin in normal and neoplastic breast tissue

The distribution of sex hormone-binding globulin-like antigens (SHBG-LA) in normal and neoplastic human breast tissues was investigated by immunohistochemistry, employing a monospecific polyclonal antiserum against highly purified human SHBG and an avidin-biotin-peroxidase complex (ABC) method in formalin-fixed paraffin embedded tissue sections. In normal breast tissues the staining of SHBG-LA was present exclusively in the cytoplasm of epithelial cells of ductal and ductular types. Nuclei as well as stromal and lymphatic tissues remained unstained. While the staining was positive in all cases of intraductal carcinoma, only 4 out of 15 infiltrating carcinomas revealed SHBG-LA. The demonstration of a plasma sex steroid binding globulin in the cytoplasm of endocrine target cells is consistent with the hypothesis that steroid-binding globulins are able to enter target cells. The apparent loss of this specific cell function in infiltrating carcinomas may result from dedifferentiation and change of cell membrane properties occurring during the process of neoplastic progression.

Preferred apical distribution of glycosyl-phosphatidylinositol (GPI) anchored proteins: a highly conserved feature of the polarized epithelial cell phenotype

We use a sensitive biotin polarity assay to survey the surface distribution of glycosyl-phosphatidylinositol (GPI) anchored proteins in five model epithelial cell lines derived from different species (dog, pig, man) and tissues, i.e., kidney (MDCK I, MDCK II, LLC-PK1) and intestine (Caco-2 and SK-CO15). After biotinylation of apical or basolateral surfaces of confluent monolayers grown on polycarbonate filters, GPI-anchored proteins are identified by their shift from a Triton X-114 detergent-rich phase to a detergent-poor phase in the presence of phosphatidylinositol-specific phospholipase C. All GPI-anchored proteins detected (3-9 per cell type, at least 13 different proteins) are found to be apically polarized; no GPI-anchored protein is observed preferentially localized to the basal surface. One of the GPI-anchored proteins is identified as carcinoembryonic antigen (CEA). Survey of MDCK II-RCAr, a mutant cell line with a pleiotropic defect in galactosylation of glycoproteins and glycolipids (that presumably affects GPI anchors) also reveals an apical polarization of all GPI-anchored proteins. In contrast, analysis of MDCK II-ConAr (a mutant cell line with an unknown defect in glycosylation) revealed five GPI-anchored proteins, two of which appeared relatively unpolarized. Our results indicate that the polarized apical distribution of GPI-anchored proteins is highly conserved across species and tissue-type and may depend on glycosylation.

Origin of type I collagen localized within oviduct epithelium of quail hyperstimulated by progesterone

Bird oviduct development is controlled by sex steroid hormones. Estrogens (E) induce cell proliferation, formation of tubular glands by epithelial cell evagination and cell differentiation. Progesterone (P) strongly increases secretory processes in E-treated quails, but inhibits cell proliferation and cell evagination. The balance between E and P is very critical for the development and morphogenesis of the oviduct. After six daily injections of low doses of E (10 micrograms day-1) and high doses of P (5 mg day-1) into ovariectomized quails, cell proliferation and secretory process are stimulated but cell evagination is totally inhibited and distribution of striated collagen is perturbed. Using antibodies against type I collagen the stroma, which is mainly composed of fibroblasts, is brightly stained, as are some regions within the epithelium. Electron microscopy shows that bundles of striated collagen fibrils appear in extracellular spaces between the lateral membranes of the epithelial cells or between the basal lamina and the epithelial basal membrane. After in situ hybridization using a 35S riboprobe specific for mRNA of the alpha 2 chain of type I collagen, mRNA was detected only in the fibroblasts of the stroma and not in epithelial cells. Furthermore electron microscope studies of collagen bundles in serial sections clearly show collagen fibrils passing through the basal lamina. It is assumed that the type I collagen between epithelial cells originates from mesenchymal cells. In the oviduct of immature birds or after physiological E + P stimulation, striated collagen is localized only in the stroma and never within the epithelium. These results indicate a modulation of extracellular matrix by sex steroid hormones in the quail oviduct.

Distribution of involucrin in normal and pathological human uterine cervix

A study was undertaken to determine the potential value of involucrin immunostaining, a protein synthesized by mature squamous epithelial cells, in distinguishing benign from neoplastic lesions in cervical pathology. A total of 146 cervical biopsies were analyzed using an indirect immunoperoxidase method and polyclonal antibody. A suprabasal homogeneous cytoplasmic staining pattern was consistently observed in normal squamous cervical epithelium. In contrast, 43.7% of cervical condylomas showed involucrin at all levels of the epithelium including the basal layer. Variable patterns were seen in cervical intraepithelial neoplasia (CIN), with 46% of full-thickness stainings, although no significant difference was obtained among the different grades of CIN lesions. Distribution of involucrin was correlated (P less than 0.05) with the degree of tumor differentiation in squamous cell carcinomas, being absent in 71.4% of poorly differentiated carcinomas and focally present in 75% of well-differentiated carcinoma. Lesions of endocervical origin, either benign or malignant, were entirely negative for involucrin. It is concluded that involucrin seems unable to establish a reliable differential diagnosis between benign and neoplastic conditions in cervical pathology, and should therefore be considered only a specific marker of squamous differentiation in both normal and pathological human uterine cervix.

Binding of Pseudomonas aeruginosa to neutral glycosphingolipids of rabbit corneal epithelium

35S-labeled Pseudomonas aeruginosa isolates were shown to bind to neutral glycosphingolipids (NGSLs) of rabbit corneal epithelia in culture by a thin-layer chromatogram overlay procedure. The lipids of the corneal epithelial cells grown in culture were extracted and partitioned into a chloroform-rich lower phase containing NGSLs and an aqueous upper phase containing gangliosides. By using a dot-blot assay, at least six times more radiolabeled P. aeruginosa isolates were shown to bind to the lipids in the lower phase compared with those in the upper phase. Thin-layer chromatography of the lower-phase lipids followed by staining with an orcinol spray revealed at least 10 NGSL components and several fast-migrating, nonglycosylated neutral lipid components (including cholesterol). 35S-labeled P. aeruginosa was shown to bind to NGSL components 1, 2, 5, 6, and 9. P. aeruginosa-reactive NGSL components 6 and 9 migrated with chromatographic mobilities similar to those of the standards ceramide trihexoside (CT) and ceramide monohexoside, respectively. Components 1 and 2 migrated slightly ahead of asialo GM1, and component 5 migrated faster than globoside but slower than CT. Among the various standards tested, P. aeruginosa bound to asialo GM1 and, to a lesser extent, to ceramide dihexoside and CT but not to GM1, GD1A, GM3, or ceramide monohexoside. It remains to be determined whether any of the five P. aeruginosa-reactive NGSL components of corneal epithelium identified in this study plays a role in the development of corneal infection. However, we have previously shown that component 9, one of the five P. aeruginosa-reactive NGSL components identified in this study, is present in significantly greater amounts in migrating epithelia than it is in nonmigrating epithelia (N. Panjwani, G. Michalopoulos, J. Song, G. Yogeeswaran, and J. Baum, Invest. Ophthalmol. Vis. Sci., in press). This may prove to be of biological significance because it is generally believed that traumatized (migrating) epithelia are more susceptible to infection than normal (nonmigrating) epithelia are.