Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Conjunctiva”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 379 records · Page 21Linked to original sources
PubMed1986

Characterization of mucus glycoconjugates in normal human conjunctiva by lectins in light microscopy, transmission and scanning electron microscopy.

Maintenance of tear film in normal conditions is dependent on mucus layer integrity and the presence and distribution of conjunctival epithelial cell microvilli. In the present work a new methodology has been developed to gain correlative information about microprojection assessment and mucus composition, from the same specimen, by Light Microscopy (LM), Transmission Electron Microscopy (TEM) and Scanning Electron Microscopy (SEM). We have characterized the glycosidic residues secreted by goblet cells in normal human conjunctiva, by means of four lectins (WGA, ConA, PNA and SBA), conjugated with FITC for LM and with colloidal gold for TEM and SEM. The cytochemical reactions were performed on histological sections of paraffin-embedded material and on semithin and ultrathin sections of both Epon embedded material directly processed for TEM and of blocks recovered from SEM and reprocessed for TEM. WGA, ConA, PNA and SBA receptors were found to be constituents of the mucus produced by goblet cells in human conjunctiva. The granules of the so-called "second mucus system" (SMS) cells were labelled mainly by WGA. A difference in the quality of glycoconjugates between goblet cells and SMS cells has been also demonstrated. Our results provide an improved method to evaluate alterations of tear film that occur in many conjunctival diseases.

Carbohydrates↗
PubMed1989

[Electron microscopic study of the iris and bulbar conjunctiva of Werner's syndrome].

We observed the iris and the upper limbal conjunctiva from the two cases of Werner's syndrome by transmission electron microscopy. Numerous microfibrils were seen between the iris pigment epithelium and the dilator muscle, and within the stroma of the conjunctiva in both patients' eyes. These similar findings in the irides of both patients suggested the relationship between the microfibrils and Werner's syndrome. Many melanosome complexes were found in iris melanocytes, and the basement membrane of the iris vessels showed marked thickening. These findings seemed to be the changes caused by aging in cases of Werner's syndrome.

Conjunctiva↗
PubMed1987

Analysis of microvascular network in bulbar conjunctiva by image processing.

A digital image processing procedure has been developed for obtaining quantitative morphometric data on the microcirculatory network in the human bulbar conjunctiva. Highlights of this semi-automated approach include: 1. extraction of morphometric information that cannot be readily obtained by manual methods--length, diameter, and diffusion distributions; 2. speed and consistency in data generation--only 10 minutes are required to scan and to analyze 6.7 mm2 of conjunctiva microvasculature. The variation was less than 5% when images of the same area in the same eye were subjected to analysis at different times; 3. avoid the human bias factor--the data obtained by repeated analysis of the same negative varied by less than 0.02%.

Conjunctiva↗
PubMedDate not supplied

[Microcirculatory disorder in the bulbar conjunctiva of patients with diabetic retinopathy].

Biomicroscopy was employed to study the state of microcirculation of the bulbar conjunctiva in 166 patients with diabetes mellitus at different stages of the ophthalmoscopic assessment of the fundus of the eye. Disorder in conjunctival microhemodynamics was found in 89.7% of the patients, in the presence of retinopathy in all the cases and in a normal picture of the fundus of the eye in 69.3%. Qualitative and quantitative changes in microcirculation of the conjunctiva were shown to depend on the stage and form of diabetic retinopathies. Values of changes of the total conjunctival index and its constituents were on an increase with aggravation of a pathological process in the fundus of the eye. Vascular changes prevailed in the diabetic-sclerotic and diabetic-hypertensive forms of retinopathies, intravascular changes and perivascular edema prevailed in the diabetic-renal form.

Adolescent↗
PubMed1985

Innervation of the conjunctiva.

A parasympathetic pathway from the facial nerve to the conjunctiva was confirmed. Many conjunctival nerve fibres were degenerated following pterygopalatine ganglion lesion in cynomolgus monkeys. Nerve terminal degeneration was found mainly in the large vessel walls and adjacent to the subepithelial capillaries. AChE positive nerve fibres of undenervated tissue, probably representing the cholinergic fibres of facial nerve origin, and sympathetic nerve terminals, identified by their small granular vesicle content, were similarly disposed in vessel walls. Hence conjunctival vessels, including capillaries, have a dual autonomic innervation. Intraepithelial terminals were sparse and no evidence of a specific goblet cell innervation was found. Human perilimbal conjunctiva displayed a similar distribution of nerve fibres to cynomolgus monkeys.

Acetylcholinesterase↗
PubMed1986

Mucoepidermoid carcinoma of the conjunctiva: report of a case in a 36-year-old with paranasal sinus invasion.

Mucoepidermoid carcinoma is a rare, highly invasive tumor of the conjunctiva that occurs in elderly persons. Although clinically indistinguishable from squamous cell carcinoma, mucoepidermoid carcinoma is more likely to recur following excision and to invade the eye. The following case report describes a 36-year-old man with mucoepidermoid carcinoma of the right caruncle that invaded orbit, paranasal sinuses, and nasal cavity. The patient is the youngest person known to have had this tumor, and represents the first reported case in which mucoepidermoid carcinoma of the conjunctiva has extended beyond the orbit. This case emphasizes the importance of prompt and adequate primary treatment.

Adult↗
PubMed1985

[Effect of lead and tetraethyl lead poisoning on the microcirculatory bed of the conjunctiva of the eye].

The ultrastructure of the bulbar conjunctiva bioptates have been studied in 12 persons suffering from lead intoxication (saturnism), 2-from tetraethyl-lead (TEL) intoxication and 3-are practically healthy persons; they make the control group. In all the patients manifested disturbances in the microcirculatory bed of the bulbar conjunctiva are revealed, the general character being identical at saturnism and TEL-intoxication. The main changes are observed in the wall of the blood microvessels: destruction of the endothelial lining up to revealing the basal membrane with adhesion of the blood formed elements and their diapedesis. This results in disorders of vascular permeability, in edema of the perivascular space and in appearance of cells and cellular detritus in it. An essential role in morphogenesis of the vascular disturbances produced by intoxication play certain rheological imparements: sludge-syndrome and microthrombosis. They produce certain distrophic changes.

Adult↗
PubMed1973

Virus excretion in smallpox. 1. Excretion in the throat, urine, and conjunctiva of patients.

Excretion of virus in the throat, urine, and conjunctiva of smallpox patients was studied daily for 2-3 weeks after the onset of fever. The virus titre in the throat and urine of haemorrhagic and confluent cases was higher than in discrete cases. The duration of virus excretion was also greater in confluent cases than in discrete cases. Conjunctival swabs from all 12 smallpox patients with conjunctivitis were positive for virus. The duration and titre of virus excretion in the throat, urine, and conjunctiva of patients were not related to their age or sex and did not depend on whether or not they had received a primary vaccination.

Adolescent↗
PubMed1980

Ultrastructure of the conjunctiva, skin, and gingiva: a case of Sandhoff's disease in a Jewish patient.

Pleomorphic membranous cytoplasmic bodies that indicated glycolipid storage were found in the conjunctiva, skin, and gingiva of a Jewish patient with Sandhoff's disease. The clinical symptoms were typical of GM2 gangliosidosis. Both hexosaminidase A and hexosaminidase B activities were deficient in the leukocytes and serum. Glycosaminoglycan levels in cultured fibroblasts were elevated. Membranous cytoplasmic bodies were observed in high concentrations in a large proportion of the vascular endothelial cells, pericytes, and Schwann cells and to a somewhat lesser extent in the fibrocytes of all tissues studied. Ultrastructural analysis of the conjunctiva, skin, and gingiva as an aid for the diagnosis of Sandhoff's disease is suggested.

Capillaries↗
PubMed1983

[Microcirculatory bed of the bulbar conjunctiva in 3- to 9-month-old fetuses].

In 32 corpses of 3-9-month-old fetuses the diameter, length amount of the microcirculatory bed vessels and their wall thickness have been studied in different areas of the eye bulb conjunctiva by means of impregnation after Kuprianov. General morphofunctional vascular peculiarities have been revealed. They are connected with age and structure of the developing tissues in the eye bulb conjunctiva. Two stages of development have been defined: 3-6 and 7-9 months.

Conjunctiva↗
PubMed1980

Melanomas of the conjunctiva.

Conjunctival melanomas are much less common than custaneous melanomas. Consequently, the classification and treatment of these mucosal tumors is more controversial than that of skin tumors. Conjunctival melanomas can be simply classified into tumors that are superficial and develop in a radial-growth phase, and those that are invasive and develop in a vertical-growth phase. By careful histological examination the maximum tumor thickness can be measured and the presence of the tumor within conjunctival epithelium, the substantia propria, or deeper tissues can be determined. Superficial tumors, tumors with a total radial-growth phase, tumors thinner than 0.76 mm., tumors confined to the conjunctival epithelium, and tumors near the corneal limbus seem to have a favorable prognosis. The fact that a conjunctival melanoma arises in an area of acquired melanosis, arises in association with a nevus, or arises de novo has not been definitely proved to be of prognostic significance. Treatment of conjunctival melanomas should be preceded by biopsy and histological confirmation of the diagnosis. Systemic evaluation should include examination of regional lymph nodes, chest roentgenograms, liver scans, and liver function tests. The eye and the complete conjunctival surface should be carefully examined, photographed, and drawn. The commonly accepted treatment of stage I melanomas of the skin or conjunctiva is surgical removal of the malignant tissue. Superficial and minimally invasive tumors near the corneal limbus may sometimes be excised with en bloc resection of the adjacent superficial cornea and sclera. Treatment of any malignant tumor must be somewhat individualized. Melanomas involving the fornices and eyelids may be treated by complete excision or by exenteration. Exenteration seems to be a reasonable plan in patients with extensive or bulky tumors. The role of prophylactic regional node dissection has not been established for patients with conjunctival melanomas. Similarly, adjunctive chemotherapy, immunotherapy, and hormone therapy are of unknown value in the management of stage I tumors of the conjunctiva. Cryotherapy and radiation therapy have been used only in small numbers of patients with conjunctival melanomas. The choice of these treatments instead of surgical excision in the management of such tumors should be highly selective.

Conjunctiva↗
PubMed1982

[Fluorescein angiographic studies of the perilimbal conjunctiva and limbus in hypertension].

Seventeen patients with vegetovascular dystonia with hypertensive reactions, 19 patients with essential hypertension at IB-IIA stages, and 26 hypertensive patients at IIB stage of the disease underwent fluorescein-angiographic study of the perilimbal conjunctiva and limb. The advantage of this method as compared to the biomicroscopic one, is that it allows one to obtain objectively documented information on the state of vessels and velocity of blood flow in them. It was established that by the method of fluorescein-angiography of the perilimbal conjunctiva region and limb there may be detected pathologic changes in the microcirculation of the field under study not only at early stages of essential hypertension but also in vegetovascular dystonia patients with hypertensive reactions, when changes on the fundus of the eye were absent.

Adult↗
PubMed1982

[Microcirculation in the conjunctiva and the nail bed in the aged. Symptomatic and clinico-pharmacologic aspects].

Study of the microcirculation primarily involves assessment of the capillaroscopic findings. In the clinical field, these are mainly obtained from small vessels of the conjunctiva and nail bed. In more recent years, microcirculation has been accompanied as a subject of examination by haemorheology. The study of blood viscosity and red cell deformability is the most promising from the practical standpoint. In the diagnostic and physiopathological evaluation of capillaroscopic findings, importance is attached to differentiation of arterial and venous vessels, the size, shape and configuration of the small vessels, and above all the presence of intravasal red cell clumps. In examination of the nail bed, particular attention is directed to oddities in the shape of the capillary loops, venous stasis and congestion pictures (in decompensated heart disease, for example, and in cor pulmonale), and alterations in the subpapillary plexuses. Examination of the conjunctiva takes account of the presence of tortuous and serpiginous vessels, with pronounced dilatations, as observed in cardiocirculatory decompensation and chronic bronchopulmonary diseases. In arteriosclerosis, tortuosity and dilatation, even as far as the formation of microaneurysms, may be accompanied by the percent of stiff, thin vessels in networks or webs of various sizes. Clinical pharmacology tests, such as those employing vasoactive drugs (xanthinol nicotinate, buflomedyl, cyticholine) are of interest. They result in a marked increase in calibre, with the appearance of collaterals, regression of red cell aggregates, and improved blood flow.

Age Factors↗
PubMed1982

Full-thickness eyelid biopsy for presumed carcinoma in situ of the palpebral conjunctiva.

A biopsy-proven diagnosis of carcinoma in situ of the palpebral conjunctiva should always evoke doubt. This change may represent pagetoid spread of an occult sebaceous gland carcinoma. The conjunctival changes may be subtle, preceding the formation of any obvious mass in the eyelid. In this situation, full-thickness eyelid biopsy should be considered as a possible alternative to diagnosis accurately the disease process. The authors present two cases where biopsy of chronically inflamed palpebral conjunctiva was at first diagnosed as carcinoma in situ. Full-thickness eyelid biopsy was performed at varying times following the conjunctival biopsy. Sebaceous gland carcinoma was then diagnosed in each case. The pathogenicity of carcinoma in situ differs markedly from sebaceous gland carcinoma. A palpebral conjunctival biopsy diagnosed as carcinoma in situ should arouse suspicion that a more serious pathologic process may be present. Full-thickness eyelid biopsy may be appropriate under such circumstances.

Adenocarcinoma↗
PubMed1981

Clinical and electron microscopic observations of the conjunctiva of adult patients with Bitot's spots.

Three adult patients with Bitot's spots of the conjunctiva were observed in the American Southwest; all were in good health without obvious cause for vitamin A deficiency. Serum vitamin A levels were low normal in two; the third patient was on replacement vitamin A therapy with resultant high serum levels. Serum beta-carotene levels were low in two and normal in one. Schirmer test without anesthesia was low normal in two and with topical anesthesia was abnormal in all. After 8 weeks of oral vitamin A therapy, the Schirmer test and Bitot's spots showed little response. Electron microscopy of Bitot's spots showed changes characteristic of keratinizing squamous epithelium: absence of goblet cells, increased tonofibrils, flattening of intermediate cells, loss of superficial cell nuclei, and a keratin layer. Light microscopy of the inferior cul-de-sac conjunctiva showed increased surface goblet cells in two and absence of such cells in the third; by electron microscopy the substructure of the majority of the goblet cell mucin granules had a reticulated appearance in which an electron-dense fibrillar network was present within the granule matrix. The non-mucin-containing epithelial cells of the inferior cul-de-sac for the most part appeared normal.

Adult↗
PubMed1994

Expression of mucin peptide and blood group ABH- and Lewis-related carbohydrate antigens in normal human conjunctiva.

PURPOSE: The immunohistochemical characterization of mucin peptide antigens and identification of blood group ABH- and Lewis-related carbohydrate antigens expressed in epithelium of normal human conjunctiva. METHODS: Immunoperoxidase characterization of conjunctival glycoproteins was performed using antibodies against peptide and saccharide moieties of gastrointestinal mucins on conjunctival biopsy specimens from 89 healthy individuals of known ABO and Lewis red cell phenotypes. RESULTS: Ocular mucins had epitopes in common with the peptidic core of gastric mucin (M1 epitopes), but also contained sialylated saccharide chains like those of intestinal mucins. Anti-M1 gastric mucins, anti-type 1 precursor, and anti-T antibodies strongly stained the cytoplasm of goblet cells. Anti-Lea, anti-NeuAc-Lea, and anti-Leb antibodies stained both epithelial and goblet cells of Lewis-positive individuals only. Anti-H type 1, anti-H type 2, anti-A, and anti-B stained epithelial cells of ABH secretors. In addition, A-like epitopes independent of secretor phenotype were found in epithelial and goblet cells of all donors. CONCLUSIONS: The conjunctival mucins cross-react with antibodies specific for digestive mucins and for blood group-related carbohydrate epitopes. The distributions of Lewis and secretor phenotypes in conjunctiva are: 19% Lewis-positive nonsecretors, 71% Lewis-positive secretors, and 10% Lewis-negative secretors. Lea and Leb antigens are present on epithelial cells of Lewis-positive nonsecretors and Lewis-positive secretors, respectively, as expected for antigens under control of Lewis and secretor genes. The secretor alpha-2-fucosyltransferase is not expressed on goblet cells, as described for the goblet cells of the distal rectal colonic mucosae. ABH antigens synthesized by the products of A1, A2, B, and Se genes and modulated by the presence of the product of the Lewis gene are found in epithelial cells. In addition, A-related epitopes independent of the A1-A2 subtype, secretor, and Lewis phenotypes also are present in both epithelial and goblet cells.

ABO Blood-Group System↗
PubMed1994

Expression of keratinocyte growth factor mRNA in ex vivo and in vitro specimens of human cornea and conjunctiva.

The expression of keratinocyte growth factor (KGF) messenger RNA (mRNA) was examined in both ex vivo and in vitro specimens of human skin, conjunctiva and cornea. Total cellular mRNA was extracted from human skin, conjunctiva, cornea, cultured skin fibroblasts, cultured conjunctival fibroblasts and cultured keratocytes. Oligo dT-primed complementary DNA (cDNA) was synthesized using each RNA sample as a template. Polymerase chain reaction (PCR) was used to amplify the DNA sequence of KGF using each cDNA sample as a template. PCR products were then digested with restriction enzymes in order to determine the KGF prototype. In all samples, PCR products of the expected size for KGF were detected. The resulting restriction pattern proved that these products were identical to KGF prototype I, ie, authentic KGF. In conclusion, human keratocytes and conjunctival fibroblasts express mRNA coding for KGF prototype I, ie, authentic KGF, in both ex vivo and in vitro specimens.

Adult↗
PubMed1994

[An immunohistochemical study of cornea and adjacent bulbar conjunctiva in Mooren's ulcer].

The specimens of the corneal lesions and their adjacent bulbar conjunctivas taken from 14 cases with Mooren's ulcers were studied by immunohistochemical techniques to investigate the expression of HLA-DR antigen and the subgroups of lymphocytes. It is discovered that there is an aberrant expression of HLA-DR antigen in a large amount of keratoconjunctival epithelial cells and stromal keratocytes and simultaneously, the CD4/CD8 ratio is significantly higher than that of the normal control group. The results suggest that the aberrant expression of MHC-II antigen in the resident cells at the peripheral cornea and its adjacent conjunctiva and a raised local TH/TS ratio leading to an excessive autoimmune reactivity be possibly the direct cause of the pathogenesis of the Mooren's ulcer.

Adult↗