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At least 19 recordsLinked to original sources

PubMed1989

Nature of so-called "metaplasia of the apocrine epithelium". Macrophages attack apocrine epithelium". Macrophages attack apocrine epithelium.

Immunohistochemical and electron-microscopic studies were performed on the lesion termed "metaplasia of the apocrine epithelium." which was seen in association with an apocrine adenocarcinoma. The cells of this so-called "metaplasia" lacked cytokeratin, which was present in the apocrine epithelium. Surprisingly, the lesion ultrastructurally consisted mainly of terminally differentiated macrophages, the cytoplasms of which were filled with numerous phagosomes and lipid droplets. The cells lacked a desmosomal connection at their borders and some had Langerhans granule-like structures in the cytoplasm. The luminal wall was often infiltrated with macrophages and lymphocytes, and, in some portions, was replaced by macrophages with a large cytoplasm filled with numerous phagosomes. The immunohistochemical and ultrastructural findings indicate that the lesion is not composed of cells of the apocrine epithelial origin, but of macrophages that have ingested apocrine epithelium.

Aged↗

PubMed2000

TR146 cells grown on filters as a model of human buccal epithelium: V. Enzyme activity of the TR146 cell culture model, human buccal epithelium and porcine buccal epithelium, and permeability of leu-enkephalin.

The objective of the present study was to characterise the TR146 cell culture model as an in vitro model of human buccal mucosa with respect to the enzyme activity in the tissues. For this purpose, the contents of aminopeptidase, carboxypeptidase and esterase in homogenate supernatants of the TR146 cell culture model, and human and porcine buccal epithelium were compared. The esterase activity in the intact cell culture model and in the porcine buccal mucosa was compared. Further, the TR146 cell culture model was used to study the permeability rate and metabolism of leu-enkephalin. The activity of the three enzymes in the TR146 homogenate supernatants was in the same range as the activity in homogenate supernatants of human buccal epithelium. In the TR146 cell culture model, the activity of aminopeptidase (13.70+/-2.10 nmol/min per mg protein) was approx. four times the activity of carboxypeptidase (3.73+/-0.53 nmol/min per mg protein), whereas the level of esterase activity was significantly higher (223.39+/-69.82 nmol/min per mg protein). In the TR146 cell culture model, the apical esterase activity was found significantly higher than the basal activity, and found comparable to the porcine buccal mucosa. However, the esterase activity on the serosal side of the porcine buccal mucosa was higher than in the TR146 cell culture model. Approx. 1.5% of leu-enkephalin permeated the TR146 cell layers within 5 h (P(app) 7.38+/-0.83x10(-7) cm/s) and approx. 77% of intact peptide was still present in the donor phase after 5 h. The present study suggests that the TR146 cell culture model is a valuable in vitro model for permeability and metabolism studies with enzymatically labile drugs, such as leu-enkephalin, intended for buccal drug delivery.

Aminopeptidases↗

PubMed1996

Gene expression of the neurotrophic pigment epithelium-derived factor in the human ciliary epithelium. Synthesis and secretion into the aqueous humor.

PURPOSE: To study the expression of the neurotrophic pigment epithelium-derived factor (PEDF), a protein with neurotrophic and neuronal-survival activities, by the human ocular ciliary epithelium. METHODS: Total RNA extracted from human and bovine ocular tissues were screened by Northern blot analysis with cDNA probes for PEDF. Antibodies to PEDF were used to monitor its synthesis and secretion by metabolically labeling ciliary processes in vitro with 35S-methionine, followed by immunoprecipitation. Pigment epithelium-derived factor antibodies also were used to visualize the cellular distribution of PEDF along the human and bovine ciliary epithelium. Polymerase chain reaction (PCR) and reverse transcription (RT)-PCR was used to screen cDNA libraries of tissue and cell lines derived from the ciliary epithelium to demonstrate PEDF expression. RESULTS: From a subtractive library of the human ocular ciliary body, the authors identified a cDNA clone exhibiting nucleotide homology with the PEDF. Northern blot analysis indicated that PEDF transcripts are present in all the ocular tissues in the human eye; in the bovine eye, it is expressed preferentially in the retinal pigment epithelium. RT-PCR and PCR demonstrated that the PEDF gene is still transcriptionally active in cultured cell lines derived from the bilayer of the ciliary epithelium. Immunoprecipitation and Western blot (immunoblot) analyses with antisera to the PEDF protein demonstrated that a predominant PEDF form of 46 kDa is synthesized in the ciliary body and is secreted as a glycoprotein of 50 kDa. By indirect immunofluorescence and immunocytochemistry, PEDF antibodies decorated both cell types that comprise the ciliary epithelium (nonpigmented and pigmented) and, more distinctively, the plasma-membrane domain of nonpigmented cells in the pars plicata region. CONCLUSIONS: These results reveal a new site of synthesis (ciliary epithelium) and accumulation (aqueous humor) of PEDF, and they emphasize its potential importance as a trophic factor in the neuro-differentiated functions of the human ciliary epithelium.

Animals↗

PubMed1996

Pigment in prostatic epithelium and adenocarcinoma: a potential source of diagnostic confusion with seminal vesicular epithelium.

Granular cytoplasmic pigment is frequently observed in prostatic epithelium, and may cause confusion with ejaculatory ductal and seminal vesicular epithelium. We evaluated the distribution and histochemical and immunohistochemical phenotype of pigment in nine serially sectioned, whole-mounted prostatectomy specimens with carcinoma. Golden yellow-brown pigment was found in prostatic glandular epithelium in eight cases (89%) of nine, varying from inconspicuous and focal to extensive and diffuse. It was usually located in the basal portion of the secretory (lumenal) cell layer, but was also observed throughout the cytoplasm, and rarely seen in basal cells. Stromal pigment was observed in seven cases (78%) of nine and was patchy and inconspicuous. Epithelial pigment was observed throughout the prostate (transition zone, 67%; central zone, 56%; peripheral zone, 89%; and periurethral glands, 56%). Focal pigment was observed in high-grade prostatic intraepithelial neoplasia in seven cases (78%) of nine and one case (11%) of nine cases of adenocarcinoma. The epithelial pigment was histochemically similar to lipofuscin pigment (Fontana-Masson positive, bleached by permanganate reaction, Prussian blue negative, and Ziehl-Neelsen positive); S100 protein immunohistochemical stains were negative. Our results indicate that pigment is frequently present in the prostatic epithelium of all zones, at least focally, and has histochemical similarities to pigment in the seminal vesicular epithelium. Awareness of prostatic epithelial pigment is important, and the differential diagnosis of pigmented epithelium in scant specimens such as those obtained from needle biopsies includes normal and neoplastic prostatic epithelium, seminal vesicle epithelium, and ejaculatory duct epithelium.

Adenocarcinoma↗

PubMed1980

Scanning electron microscopic studies of the surface morphology of the vomeronasal epithelium and olfactory epithelium of garter snakes.

Fixed vomeronasal and olfactory epithelia from normal adult garter snakes were microdissected, fractured, and examined with a scanning electron microscope. The method permits a detailed comparative study of the structural organization and morphological characteristics of the constituent cells of the vomeronasal and olfactory epithelia. Despite similarities in the nomenclature of the constituent cells in both epithelia, significant differences exist in their surface morphology. A unique columnar structure composed of non-neuronal elements is present in the vomeronasal epithelium. These columns house the bioplar neurons and undifferentiated cells. Such a columnar organization is absent in the olfactory epithelium. In vomeronasal epithelium the bipolar neurons possess microvillous terminals at their dendritic tips, while the dendritic tips of the bipolar neurons of the olfactory epithelium possess cilia. Vomeronasal supporting cells are covered with microvilli, while olfactory supporting cells are covered with cytoplasmic protuberances in addition to the microvilli. In the vomeronasal epithelium the pear-shaped neurons have a grossly smooth surface and are organized into clusters, while in the olfactory epithelium the elliptical bipolar neurons are spinous, aligned side-by-side and interdigitate. The basal (undifferentiated) cell layer in the vomeronasal epithelium has a high packing density and is composed of several layers of irregularly shaped cells. In the olfactory epithelium the basal cell layer is loosely organized and composed of a single layer of oval cells. This information on the three-dimensional cell structure of both epithelia provides a basis for experimental observations on changes in morphology of the bipolar neurons during genesis, development, maturation, degeneration, and regeneration in postnatal, adult animals.

Animals↗

PubMed1985

Intermediate filament cytoskeleton of amnion epithelium and cultured amnion epithelial cells: expression of epidermal cytokeratins in cells of a simple epithelium.

Using immunofluorescence microscopy and two-dimensional gel electrophoresis, we compared the cytoskeletal proteins expressed by human amnion epithelium in situ, obtained from pregnancies of from 10-wk to birth, with the corresponding proteins from cultured amnion epithelial cells and cultures of cells from the amniotic fluid of 16 week pregnancies. Epithelia of week 16 fetuses already display tissue-specific patterns of cytokeratin polypeptides which are similar, although not identical, to those of the corresponding adult tissues. In the case of the simple amnion epithelium, a complex and characteristic complement of cytokeratin polypeptides of Mr 58,000 (No. 5), 56,000 (No. 6), 54,000 (No. 7), 52,500 (No. 8), 50,000 (No. 14), 46,000 (No. 17), 45,000 (No. 18), and 40,000 (No. 19) is present by week 10 of pregnancy and is essentially maintained until birth, with the addition of cytokeratin No. 4 (Mr 59,000) and the disappearance of No. 7 (Mr 54,000) at week 16 of pregnancy. In full-term placentae, the amnion epithelium displays two morphologically distinct regions, i.e., a simple and a stratified epithelium, both of which express the typical amnion cytokeratin polypeptides. However, in addition the stratified epithelium also synthesizes large amounts of special epidermal cytokeratins such as No. 1 (Mr 68,000), 10 (Mr 56,500), and 11 (Mr 56,000). In culture amnion epithelial cells obtained from either 16-wk pregnancies or full-term placentae will continue to synthesize the amnion-typical cytokeratin pattern, except for a loss of detection of component No. 4. This pattern is considerably different from the cytokeratins synthesized by cultures of cells from amniotic fluids (cytokeratins No. 7, 8, 18, and 19, sometimes with trace amounts of No. 17) and from several so-called "amnion epithelial cell lines." In addition, amnion epithelial cells in situ as well as amnion epithelial cell cultures appear to be heterogeneous in that they possess some cells that co-express cytokeratins and vimentin. These observations lead to several important conclusions: In contrast to the general concept of recent literature, positively charged cytokeratins of the group No. 4-6 can be synthesized in a simple, i.e., one-layered epithelium. The change from simple to stratified amnion epithelium does not require a cessation of synthesis of cytokeratins of the simple epithelium type, but in this case keratins characteristic of the terminally differentiated epidermis (No. 1, 10, and 11) are also synthesized.(ABSTRACT TRUNCATED AT 400 WORDS)

Amnion↗

PubMed1999

Immunohistochemical localization of glutathione S-transferase alpha and pi in human esophageal squamous epithelium, Barrett's epithelium and carcinoma.

High tissue levels of glutathione S-transferases (GSTs), a family of detoxification enzymes, are inversely correlated with cancer risk in the human gastrointestinal tract. Patients with Barrett's esophagus, wherein squamous epithelium is replaced by columnar epithelium, have an increased risk for developing esophageal adenocarcinoma. Biochemical analyses revealed that Barrett's epithelium contains lower levels of GST enzyme activity as well as some GST isoforms, as compared with squamous epithelium. So far, little information on the immunohistochemical distribution of the GST alpha and pi isoforms in normal squamous epithelium, in Barrett's metaplastic epithelium or in adeno- and squamous cell carcinomas of the esophagus is available. Tissues were fixed in formalin and embedded in paraffin. Three 4 microm thick sections were used for hematoxylin and eosin staining and for immunostaining with antibodies against GST alpha and pi. GST alpha and pi were seen in normal squamous epithelium (0% and 75%, respectively), Barrett's epithelium (75% and 100%), adenocarcinoma (25% and 100) and squamous cell carcinoma (27% and 91%). Staining was mainly cytoplasmic, though some nuclear staining with the GST pi antibody was apparent. The varying expression of GST alpha and pi in normal and (pre)neoplastic esophagus may have consequences for the treatment of these diseases and may contribute to an understanding of the development of these esophageal disorders.

Adenocarcinoma↗

PubMed1979

The respiratory epithelium. VII. Epidermoid metaplasia of hamster tracheal epithelium during regeneration following mechanical injury.

Regeneration was studied in female Syrian golden hamster tracheal epithelium. The epithelium was focally removed in vivo by scraping it with a blunt probe. At 2 hours, virtually all cells had sloughed from the injured area leaving a bare basal lamina. At 6 and 12 hours, flattened cells that migrated from adjacent uninjured epithelium partially covered the denuded basal lamina. Increased cell division did not occur at these times. Many of the simple squamous cells contained well-developed endoplasmic reticulum, Golgi apparatus, and mucous granules. Other cells resembled basal cells. At 24 hours the defect was covered by one or two layers of simple squamous cells. At that time, many of those cells were in division, and cell division was also greatly increased in mucous cells and basal cells in the uninjured epithelium distant from the defect. At 48 hours the epithelium was stratified, composed of four or five layers of polygonal to flattened cells, typical of nonkeratinizing epidermoid metaplasia. The cells contained many tonofilament bundles, a large Golgi apparatus, and many tiny mucous granules. Mitoses were seen in all cell layers. At 72 hours, the surface layer of cells was undifferentiated (indifferent cells) overlying an epithelium that otherwise retained its epidermoid character. Indifferent cells were characterized by an electron-lucent cytoplasm and a lack of tonofilament bundles, mucous granules, or cilla. Cells similar in other respects to indifferent cells were seen that possessed mucous granules or early signs of cilla formation. Some cells showed mucous granules and cilla developing in the same cell. By 96 hours, the regenerated epithelium was fully differentiated and was indistinguishable from the normal epithelium. These observations show that mucous cells have a significant role in the regenerative response. Mucous cells have a dual potential; they can undergo epidermoid metaplasia and still retain the ability to secrete mucus. The study explains the universal occurrence of mucosubstances in areas of epidermoid metaplasia and makes more understandable the previously reported fact that many bronchogenic carcinomas are combined epidermoid and adenocarcinomas. In the presence of a carcinogen, the hypothesis has been forwarded that initiation of mucous cells and basal cells occurs, which leads to malignant transformation and produces tumors that show active secretory activity and keratinization, often in the same cell.

Animals↗

PubMed2003

Survival in high-risk eyes of epithelium-deprived orthotopic corneal allografts reconstituted in vitro with syngeneic epithelium.

PURPOSE: In low-risk eyes of mice, most of the composite corneal grafts composed of syngeneic epithelium layered on allogeneic stroma and endothelium are accepted indefinitely. The study was undertaken to determine the fate of similar composite corneal grafts placed in high-risk mouse eyes. METHODS: Epithelium-deprived allogeneic corneas (C57BL/6) were reconstituted in vitro with BALB/c epithelium, and then transplanted orthotopically into high-risk eyes of BALB/c mice. Graft survival was assessed clinically and evaluated histologically. Acquisition of donor-specific delayed hypersensitivity (DH) was also assessed in recipient mice. Recipients bearing healthy composite grafts were immunized subcutaneously with injected C57BL/6 spleen cells at 2 or 8 weeks after grafting, after which the fate of the grafts was evaluated. RESULTS: Virtually all epithelium-deprived corneal allografts reconstituted in vitro with normal BALB/c corneal epithelium survived indefinitely when placed in high-risk eyes of BALB/c mice. Recipients of these composite grafts failed to acquire donor-specific DH when tested at both 2 and 8 weeks after grafting. Moreover, these recipients did not acquire the capacity to actively suppress donor-specific DH. Within 1 to 3 weeks of sensitization of recipient mice with spleen cells of donor origin, healthy composite grafts in residence for 2 or 8 weeks were rejected. CONCLUSIONS: Replacement of donor epithelium with syngeneic epithelium protects orthotopic allogeneic corneal grafts (stroma plus endothelium) placed in high-risk eyes from sensitizing their recipients and from immune-mediated rejection. Recipients of composite corneal grafts containing syngeneic epithelial layers act as though they are immunologically ignorant of the graft's presence.

Animals↗

PubMed1998

Reactive oxygen species (ROS) generated by xanthine oxidase in the corneal epithelium and their potential participation in the damage of the corneal epithelium after prolonged use of contact lenses in rabbits.

Prolonged use of contact lenses (for 14 days) evoked an imbalance between the activity of xanthine oxidase (an enzyme belonging to reactive oxygen species-generating oxidases) and catalase (an enzyme belonging to reactive oxygen species-scavenging oxidases) in the corneal epithelium of rabbits. The activity of catalase decreased, while xanthine oxidase activity was very high. Of other enzymes studied in the corneal epithelium, the activities of xanthine oxidoreductase, glucoso-6-phosphate dehydrogenase and succinate dehydrogenase were decreased. In contrast, the activities of lactate dehydrogenase and lysosomal hydrolases (acid beta-galactosidase, dipeptidyl peptidase II) were increased and appeared in animals sacrificed immediately after contact lens removal. In rabbits sacrificed later (after 1 h), an additional increase of lactate dehydrogenase and lysosomal hydrolase activities developed in the superficial layers of the corneal epithelium. Catalase supplementation during use of contact lenses prevented both the significant decrease of catalase activity in the corneal epithelium and the development of additional epithelial damage. In contrast, topical treatment with 3-aminotriazole (an inhibitor of catalase) resulted in the nearly complete loss of catalase activity in the corneal epithelium and the appearance of more serious epithelial damage. We conclude that ROS generated by xanthine oxidase induce additional damage of the corneal epithelium related to the use of contact lenses.

Animals↗

PubMed1990

The epithelium lining the orifice of the laryngeal gland of the Suncus murinus, with special reference to the "intermediate epithelium (Nakano)".

In the lateral wall of the laryngeal ventricle of the Suncus murinus, only a few excretory ducts of the laryngeal gland opened that drained the extensive lobular system. The ducts opened into the "intermediate epithelium (NAKANO, T.: Acta Anat. 127: 22-47, 1986)," which lined the transitional zone between the ciliated columnar epithelium and the stratified squamous one, and that showed gradations ranging from the ciliated stratified low-columnar through stratified cuboidal to stratified squamous type. The orifice of the laryngeal gland was relatively wide for the size of the animal and, therefore, the epithelium within the orifice was clearly observed by use of SEM. As the number of the ciliated cells decreased in the intermediate epithelium surrounding the orifice, the ciliated cells within the orifice reduced in number. Considering from these findings, it is suggested that the epithelium within the orifice has morphologically close resemblance to, and is influenced by, the epithelium surrounding the orifice.

Animals↗

PubMed1998

Lectins in the vulva. I. Normal vulvar epithelium and epithelium adjacent to vulvar intraepithelial neoplasia and squamous cell carcinoma.

Lectins were used to investigate the cell surface oligosaccharide expression in normal vulvar epithelium from premenopausal and postmenopausal volunteer women. In addition, histologically normal epithelium adjacent to high-grade vulvar intraepithelial neoplasia (VIN III) and adjacent to vulvar tumors was examined with lectins for evidence of a possible "field change" surrounding these vulvar lesions. Seventeen vulvar biopsies were obtained prospectively from volunteer women, and 20 and 40 cases, respectively, of VIN III and vulvar squamous cell carcinoma were randomly chosen from pathology archives. Thirteen of the 20 VIN cases and all 40 vulvar carcinomas contained at least 2 cm of histologically normal-appearing epithelium adjacent to the vulvar lesion suitable for analysis. No alterations to lectin binding in normal vulvar epithelium with respect to patient age, menopausal status, phase of menstrual cycle, estrogen therapy, or history of cervical intraepithelial neoplasia were shown. ABO blood group antigen status affected epithelial binding for lectins HPA and UEAI (p < 0.005 and p < 0.001, respectively). In addition, lectins SNA, MPA, and LCA identified markers of cellular differentiation and maturation. T-antigen expression (as shown by the lectin PNA) was almost universally present in histologically normal epithelium adjacent to VIN and vulvar tumors, contrasting with the lack of PNA binding in normal vulvar epithelium from volunteer women (p < 0.001 and p < 0.001), a finding suggestive of a local "field change" surrounding preinvasive and invasive vulvar lesions.

ABO Blood-Group System↗

PubMed1989

[Ultrastructural and immunohistochemical studies of regenerating epithelium-stroma junctions of rat tracheal epithelium after mechanical injury].

Regeneration of the rat tracheal epithelium following mechanical injury was studied by electron microscopy and immunohistochemistry. The first event that occurred following the injury was rapid flattening of the viable epithelial cells of the wound margin and their migration to the injured area. In the early stage, the regenerating epithelium changed from a simple squamous to a multilayered structure, or typical squamous metaplasia. Immunohistochemically, keratin was detected in the regenerating cells, and actin was present linearly along the basal cell membrane of the migrating epithelial cells. Fibronectin also appeared in the wounded stroma immediately beneath the migrating epithelium until the migration was completed. Both laminin and type IV collagen reappeared under the regenerating epithelium from the wound margin after the migration was completed in the middle stage. Ultrastructurally, fibronexus-like structures and so-called anchoring filaments appeared in the epithelium-stroma junction before hemidesmosomes, basal lamina and anchoring fibrils reappeared. We consider that both fibronexus-like structures and anchoring filaments are responsible for the initial adhesion of the regenerating epithelium to the underlying connective tissue.

Animals↗

PubMed1983

Co-cultivation of retinoblastoma with fibroblasts, iris pigment epithelium, and retinal pigment epithelium in tissue culture.

Retinoblastoma cells of the Y79 line were co-cultivated with human fibroblasts and bovine iris and retinal pigment epithelium in tissue culture. The Y79 cells, which characteristically grow as a suspension culture, were found to attach directly to the fibroblasts and pigment epithelium on the flask surface. Electron microscopic examination of the fibroblast-retinoblastoma co-cultures revealed numerous pinocytotic vesicles lining the fibroblast cell borders that were in contact with the tumor cells. The retinoblastoma cells contained increased numbers of ribosomes, endoplasmic reticulum, and-mitochondria. Fibroblastic processes appeared to wrap around and engulf tumor cells. In both the iris and retinal pigment epithelium co-cultures with retinoblastoma cells, there were increased numbers of mitochondria in the tumor cells in areas adjacent to pigment epithelium but no pinocytotic vesicles were seen. The pigment epithelium attached to Y79 cells showed fewer processes than did the fibroblasts in co-culture. In summary, both fibroblast and pigment epithelium functioned as an effective carrier cell layer for retinoblastoma cells. In addition, we believe that the fibroblast layer removed substances secreted by the tumor cells via pinocytotic vesicles.

Animals↗

PubMed1997

Influence of hyperoxia on in vitro growth of rabbit middle ear epithelium and auditory meatal epithelium.

The oxygen partial pressure of middle ear gas increases more than 3-fold upon insertion of ventilation tubes, while the carbon dioxide partial pressure decreases. Whereas the middle ear gas is normally equilibrated to venous gases and has an oxygen partial pressure of 43 mmHg, 138 mmHg is measured in ventilated ears. The present study was undertaken to compare the effects of these oxygen tensions on in vitro growth and glycoprotein secretion of rabbit middle ear epithelium and for comparison auditory meatal epithelium. Cultures were incubated in atmospheres of 7, 21 or 75% O2 in 5% CO2 and the remnant N2. The cell layer protein mass, [3H]thymidine-incorporation, DNA content and [3H]glucosamine-incorporation was measured in identical subcultures every third day during a 15-day period. In middle ear epithelium the DNA content, DNA synthesis and cell layer protein mass were significantly higher at 7% oxygen compared to 21% and 75%. In conclusion hyperoxia leads to decreased growth of middle ear epithelium in vitro. If applicable to in vivo conditions, this might contribute to the mechanism of action of ventilation tubes. Moreover the proliferation rate of auditory meatal epithelium exceeds that of middle ear epithelium both at 7 and 21% oxygen, an interesting point with regards to cholesteatoma pathogenesis.

Animals↗

PubMed1985

Metaphase-arrest technique applied to human cervical epithelium. II. Cell production rates in normal and pathological cervical epithelium.

An application of the metaphase-arrest technique to human cervical epithelium, in vivo, was utilized to obtain cell birth rate data for seventy-six patients with normal and pathological cervical epithelium. Mean cell production rates for basal and parabasal layers of normal epithelium were 0.91 and 0.92 cells/1000 cells/hr respectively. Histologically normal epithelium adjacent to CIN (cervical intra-epithelial neoplasia) had a significantly higher rate for the parabasal layer compared to the 'normal' group (P less than 0.05). Values for the lower two-thirds of CIN III were 8-10 times higher than for normal epithelium, with microinvasive carcinoma having the highest rates of all. Values for wart-affected cervical epithelium (NCWVI) were intermediate between normal and CIN, but there was activity in the superficial layer, possibly reflecting activity of the papilloma virus. Large variation in birth rates between individuals in the same histological category was noted for each group, this being particularly the case in six patients with early invasive carcinoma. The data is used to attempt to elucidate some of the uncertainties surrounding the aetiology and biological behaviour of cancer of the cervix and its precursors. Sources of inaccuracy are emphasized and practical difficulties discussed.

Adult↗

PubMed1987

Nonolfactory surface epithelium of the nasal cavity of the bonnet monkey: a morphologic and morphometric study of the transitional and respiratory epithelium.

The purpose of the present study was to characterize ultrastructurally the nonolfactory nasal epithelium of a nonhuman primate, the bonnet monkey. Nasal cavities from eight subadult bonnet monkeys were processed for light microscopy, and scanning and transmission electron microscopy. Nonolfactory epithelium covered the majority of the nasal cavity and consisted of squamous (SE), transitional (TE), and respiratory epithelium (RE). Stratified SE covered septal and lateral walls of the nasal vestibule, while ciliated pseudostratified RE covered most of the remaining nasal cavity. Stratified, nonciliated TE was present between SE and RE in the anterior nasal cavity. This epithelium was distinct from the other epithelial populations in abundance and types of cells present. TE was composed of lumenal nonciliated cuboidal cells, goblet cells, small mucous granule (SMG) cells, and basal cells, while RE contained ciliated cells, goblet cells, SMG cells, basal cells, and cells with intracytoplasmic lumina lined by cilia and microvilli. TE and RE contained similar numbers of total epithelial cells and basal cells per millimeter of basal lamina. TE was composed of more SMG cells but fewer goblet cells compared to RE. We conclude that nonolfactory nasal epithelium in the bonnet monkey is complex with distinct regional epithelial populations which must be recognized before pathologic changes within this tissue can be assessed adequately.

Animals↗

PubMed1994

Arachidonate 15-lipoxygenase in human corneal epithelium and 12- and 15-lipoxygenases in bovine corneal epithelium: comparison with other bovine 12-lipoxygenases.

Lipoxygenases of bovine and human corneal epithelia were investigated. The bovine epithelium contained an arachidonate 12-lipoxygenase and a 15-lipoxygenase. The 12-lipoxygenase was found in the microsomal fraction, while the 15-lipoxygenase was mainly present in the cytosol (100,000 x g supernatant). 12S-Hydroxyeicosatetraenoic acid (12S-HETE) and 15S-hydroxyeicosatetraenoic acid (15S-HETE) were identified by GC-MS and chiral HPLC. BW A4C, an acetohydroxamic acid lipoxygenase inhibitor, reduced the biosynthesis of 12S-HETE and 15S-HETE by over 90% at 10 microM. IC50 for the 12-lipoxygenase was 0.3 microM. The bovine corneal 12-lipoxygenase was compared with the 12-lipoxygenases of bovine platelets and leukocytes. All three enzymes metabolized 14C-labelled linoleic acid and alpha-linolenic acid poorly (5-16%) in comparison with [14C]arachidonic acid. [14C]Docosahexaenoic acid and [14C]4,7,10,13,16-docosapentaenoic acid appeared to be less efficiently converted by the corneal enzyme than by the platelet and leukocyte enzymes. Immunohistochemical analysis of the bovine corneal epithelium using a polyclonal antibody against porcine leukocyte 12-lipoxygenase gave positive staining. The cytosol of human corneal epithelium converted [14C]arachidonic acid to one prominent metabolite. The product co-chromatographed with 15S-HETE on reverse phase HPLC, straight phase HPLC and chiral HPLC. Our results suggest that human corneal epithelium contains a 15-lipoxygenase and that bovine corneal epithelium contains both a 15-lipoxygenase and a 12-lipoxygenase. The corneal 12-lipoxygenase appears to differ catalytically from earlier described bovine 12-lipoxygenases.

12-Hydroxy-5,8,10,14-eicosatetraenoic Acid↗