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At least 19 recordsLinked to original sources
PubMed1975

In vitro uptake of bile acids by choroid plexus, kidney cortex and anterior uvea. I. The iodipamide-sensitive transport systems in the rabbit.

Renal cortex, anterior uvea, lateral choroid plexus and terminal ileum accumulate -14C-cholate, glycocholate, deoxycholate and chenodeoxycholate to considerable tissue/medium ratios. Iodipamide partly inhibits accumulation by kidney, uvea and plexus but not ileum. In renal cortex the sensitive part is similar to 10, 60 and 90 percent for dihydroxy acids, cholate and glycocholate respectively. Hippurate depresses uptake in kidney and uvea but hardly in plexus. Simultaneous uptake by renal cortex and uvea of -14C-cholate or glycocholate, -125I-iodipamide and -131I-o-iodohippurate was studied with unlabelled iodipamide and hippurate as inhibitors. The concentration-dependence of the inhibition required the assumption of 4 partly overlapping iodipamide-sensitive transport systems handling the 4 test substances: the hippurate (H)-system, one moderately (L(1)) and one very hippurate-resistant (L(2)) part of the liverlike L-system and a fourth system called BS, more evenly inhibitable by iodipamide and hippurate than the others. The L(2)-system carries iodipamide but very little bile acids. No iodipamide-sensitive system clearly specialized for bile acid transport was found. The systems have only moderate affinity for bile acids and probably treat them just as large organic anions. A new mathematical procedure to test the degree of complexity of composite transport systems without kinetic assumptions was used.

Animals↗
PubMed1992

An experimental model of ectropion uveae and iris neovascularization in the cat.

Neovascularization of the iris (NVI) is one of the most frequently studied intraocular vascular proliferations in animal models. Ectropion uveae has not been a consistent finding in these studies. In this study, a surgical model of ectropion uveae and iris neovascularization was developed that involved lensectomy, vitrectomy, bipolar cautery and transection of all three principal branch veins in the cat eye. Twelve of 14 eyes that received this procedure developed postoperative retinal detachments with a clinical picture of hemorrhagic retinopathy. These eyes progressed to a clinical picture of NVI within 1-7 wk. Eight eyes developed ectropion uveae for as much as 300 degrees. At the light microscopic level, a fibrovascular membrane was apparent on the anterior iris stroma in 9 of 14 eyes and further involved the angle in six eyes.

Animals↗
PubMed1991

The 1990 Endre Balazs Lecture. Effects of some neuropeptides on the uvea.

This lecture summarizes studies on the effects of some of the neuropeptides which seem to be present in somatosensory and autonomic nerves in the uvea. Release of these peptides is likely to explain nerve induced effects in the eye which are not due to classical transmitters. Trigeminal nerve fibres in the eye seem to contain substance P (SP), calcitonin gene-related peptide (CGRP), and cholecystokinin (CCK), parasympathetic nerve fibers from the facial nerve seem to contain vasoactive intestinal polypeptide (VIP), and peptide with histidine and isoleucine terminals (PHI), and sympathetic nerves seem to contain neuropeptide Y (NPY). Retrograde trigeminal nerve stimulation in rabbits causes hyperemia, miosis, a breakdown of the blood-aqueous barrier to plasma proteins and a rise in intraocular pressure (IOP). There is release of SP and CGRP or related peptides. The miosis seems to be due to SP and the other effects to CGRP and small amounts of arachidonic acid metabolites released by the peptides. SP has no miotic effect in monkeys and cats. However, CCK is a potent miotic in monkeys and causes contraction of the human pupillary sphincter muscle. It has no such effect in the lower species. The effect of CCK in primates seems to derive from the presence of CCK receptors of the A-type on the pupillary sphincter muscle, and can be blocked by lorglumide. Miosis can be produced in cats by the peptide endothelin; this effect is due to release of arachidonic acid metabolites. Facial nerve stimulation causes vasodilation in the uvea of rabbits, cats and monkeys. The effect cannot be abolished by muscarinic blocking agents.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

Mast cells in the anterior uvea of the rabbit. Intraocular effects of compound 48/80 in the rabbit.

In the present study, the presence and localization of mast cells and the intraocular effects of compound 48/80 have been studied in detail in the rabbit eye using histochemical and physiological methods. In histochemical studies mast cells were localized in the anterior uvea, especially in the ciliary and iridial processes. Intracamerally injected, compound 48/80 caused an increase in the intraocular pressure, disruption of the blood-aqueous barrier and an increase in the cAMP content in the aqueous humour. Miosis was observed only after higher doses of compound 48/80 (greater than 100 micrograms) and even then only one-half of the eyes responded. The intraocular effects, excluding miosis, of compound 48/80 resembled an on/off-type of response, where 20 micrograms caused only minor changes, if any, and 50 micrograms gave a maximal response. The ocular hypertensive reaction developed a tachyphylaxis so that the second and third consecutive dose of compound 48/80 (100 micrograms) produced no significant change in IOP. The results indicate that mast cells, which are present in the anterior uvea in an extent not known previously, might be involved in certain inflammatory reactions in the rabbit eye. The inconsistent and slight miosis after the intracameral application of compound 48/80 indicates that the mechanism is different from that caused by sensory nerve stimulation. The rapid development of tachyphylaxis after consecutive application of compound 48/80 suggests that mast cells are easily depleted which might be useful for further studies to evaluate the functional role of mast cells in different pathophysiological conditions in the rabbit eye.

Animals↗
PubMed1979

Diagnosis and management of cancer metastatic to the uvea: a study of 70 cases.

Although metastatic cancer to the uvea is reported to be the most common intraocular malignancy, most ophthalmologists have had little experience with its diagnosis and treatment. This report describes our experience with the diagnosis and management of 70 patients with metastatic cancer to the uvea. Many patients were evaluated with modern diagnostic modalities such as fluorescein angiography, ultrasonography, and the 32P test when indicated. Thirty-one percent of patients had no history of previous malignancy, and the ocular complaints represented the first symptoms of systemic cancer. The ocular malignancy often simulated better-known ophthalmic entities, and the referring diagnosis was correct in only 38% of cases. This series, therefore, reflects the clinical problem confronting the practicing ophthalmologist. About one-half of the patients were treated with external beam irradiation to the involved eye(s), which often resulted in dramatic resolution of the tumor and visual return. Other patients had either no treatment, chemotherapy, or enucleation in selected instances.

Adult↗
PubMed1991

Microfibril-microvessel connections in the uvea and optic nerve of the mammalian eye.

Light- and electron-microscopic examination of arterioles, venules and capillaries of the eyes of several mammalian species has shown that the microfibrils of ocular elastic tissue attach to microvascular basement membranes throughout the uvea (iris, ciliary body, choroid) and optic nerve. Although described sporadically in prior investigations, this report shows that the connections are a common feature of the mammalian eye. The connections appear most numerous at venules and capillaries and are sparse at arterioles. The connections may provide a mechanism by which perivascular elastic tissue influences microvascular function, e.g. the control of blood pressure in them or their response to changes in intraocular pressure.

Animals↗
PubMed1976

[Clinically unsuspected malignant melanomas of the posterior uvea (author's transl)].

Out of 1300 eyes enucleated between 1966-1974, 300 subsequently revealed histologically-proved malignant melanomas of the uvea. In 264 cases the clinical diagnosis was correctly made. In 36 cases the i.o. malignant melanomas were clinically unsuspected. The incorrect clinical diagnoses included: secondary glaucoma (30), retinal detachment (2), iritis (2), and end/panophthalmitis (2). The clinical symptomatology and morphology of the secondary glaucoma caused by the i.o. melanomas did not differ from that due to other, non-neoplastic etiologies. In almost all of the 36 cases the eyes revealed unilateral severe opacity of the media. It is important that one consider an intraocular melanoma in cases of secondary glaucoma, retinal detachment, or intraocular inflammation in which the etiology is uncertain. This is also true in cases of blind, painful eyes in which there is no obvious etiology. Early diagnosis is of vital interest to the patient because this group, in which the malignant melanoma was unsuspected, may be, as suspected in this study, is characterised by extreme aggressivness and invasive capacity. One third of these eyes revealed extension of tumor through the sclera and optic nerve. Also these tumors often revealed more malignant cell types.

Adult↗
PubMed1991

[Contrast-enhanced MRT of malignant melanoma of the uvea].

Twenty-one patients with malignant melanoma of the uvea or iris, some with intra-ocular bleeding, were examined by MRT before and after the administration of Gd/DTPA. In 13 patients, several examinations were performed over a period of 1.5 to 20 months after irradiation of the melanoma. After Gd-DTPA there was an average increase of 13% in the signal intensity from all non-irradiated melanomas (17 cases). Three months following radiation therapy, there was an average increase in signal intensity after Gd-DTPA of 65.7%, and after seven months of 100%. Amelanotic melanomas (two cases) showed a primary increase in intensity of 100%. Two melanomas of the iris were demonstrated by sonography; of these, only one could be shown with certainty by MRT. Small tumours and tumour residues after irradiation were better defined after contrast. In the presence of suspected intra-ocular bleeding, the examination should always be performed after the administration of Gd-DTPA.

Adult↗
PubMed1992

Localization of elastic fibers and elastin mRNA in the uvea of chick embryo.

The distribution of elastic fibers and elastin mRNA was studied in the uvea of 19-day-old chick embryos by light and electron microscopy and in situ hybridization techniques using a 35S-labeled RNA probe. Light and electron microscopic examination revealed that elastic fibers were present in the uveal portion of the ciliary body, but not in the posterior choroid. Electron microscopically, elastic fibers were also found in Bruch's membrane. Abundant amounts of elastin mRNA were strictly localized in the fibroblasts in the uveal portion of the ciliary body, and no elastin mRNA was found in any of the cells in the posterior choroid by in situ hybridization. Cultured uveal tissue obtained from the ciliary body was found to produce large amounts of tropoelastin as compared with cultured posterior choroid. Using V8 protease peptide mapping and Northern blot analysis, the tropoelastin and its mRNA produced by the ciliary body were identical to those produced by the smooth muscle cells in the aorta. The results suggest that elastin is synthesized in the ciliary body, acting as a supporting substance in this area.

Animals↗
PubMed1977

Immunological studies in patients with malignant melanoma of the uvea.

Antibodies directed against different components of ocular melanoma cells were identified by indirect immunofluorescence in the sera of 12 patients with histologically proven malignant melanoma of the uvea. Antibodies reacing with autologous surface membrane antigens were found only in the sera of the 5 patients with the smallest tumors. The sera from most of the patients with small, large, or extraocular tumor contained antibodies directed against autologous cytoplasmic components while about one-half of the tests for antibodies reacting with allogeneic cytoplasmic antigens were positive. The incidence of positive tests with cytoplasmic antigens, in 67 patients with clinically diagnosed benign uveal nevi and 56 other individuals not showing evidence of proliferative lesions of uveal melanocytes, was 25%.

Adult↗
PubMed1975

The uvea.

Explore the source record for details and available documents.

Animals↗
PubMed1978

Metastatic adenocarcinoma to the anterior uvea and elevated CEA levels.

A 47-year-old man developed chronic unilateral iridocyclitis with secondary glaucoma, and elevated plasma CEA levels. The eye was enucleated seven months later, and histopathologic examination revealed a metastatic mucin producing CEA positive adenocarcinoma. The patient died one year after the initial onset of symptoms. The primary site of the tumor was not proven, but most likely was the gastrointestinal tract.

Adenocarcinoma↗
PubMed1992

[Static and dynamic infrared thermometry and thermography in malignant melanoma of the uvea and conjunctiva].

BACKGROUND: Thermometry and -graphy prove asymmetries of the circulation. Contact-free thermometry of the cornea is applied to find out whether this method can contribute to differential diagnosis of ocular melanomas. MATERIALS AND METHODS: Under standardized conditions the temperature of the cornea was measured in 30 patients with malignant melanoma of the choroid and the conjunctiva and 35 healthy subjects. The instruments were a handpyrometer (HPM, Messgerätewerk, Magdeburg) and the thermovision camera of AGA Infrared System, Sweden, with dynamic recording in colour. RESULTS: In healthy subjects there are no significant asymmetries in temperature under standardized conditions. The temperature of the cornea is elevated in both malignant melanomas of the choroid and the conjunctiva. CONCLUSIONS: Thermometry and -graphy of the cornea can contribute to the differentiation of malignant ocular melanomas from other ophthalmological diseases. They are also suited in long term observation of the course of the melanomas.

Body Temperature Regulation↗
PubMed1977

Movement of horseradish peroxidase in the cornea, sclera and the anterior uvea.

The anterior chambers of rabbit, monkey and human eyes were perfused with horseradish peroxidase. The perfusion was started immediately after enucleation of the monkey and human eyes, while the rabbit eyes were perfused in situ after the animals had been killed. Comparative results were obtained after 1 h or perfusion and were mainly based on frozen sections. Intensive staining was found in the Descemet's membrane, the sclera and the iridial stroma, considerably more than in the corneal stroma and in the ciliary body base. In the vervet monkey and human eyes only traces of peroxidase reaction products were seen in the stroma of the ciliary body base. The movement of the protein tracer from the anterior chamber into the corneal stroma is probably dependent upon vesicular transport across the corneal endothelium. The Discemet's membrane was interpreted to be more porous than the corneal stroma. A transcorneal and a corneo-scleral movement appeared to be more efficient than the uveo-scleral one, at least in the vervet monkey and the human eyes.

Animals↗