摘要:

Purpose, Endothelin-1 (ET-I) has been found to accelerate rabbit corneal epithelial wound healingin vivoand proliferation of rabbit and bovine epithelial cellsin vitro.We have now determined (hat Endothelin-like immunoreactivity (ET-LI) is present in the tear fluid of New Zealand white rabbits, and we have addressed the question of whether it is produced by the tear glands (lacrimal gland and Harderian gland).Methods.Tears were obtained with capillary pipettes and lacrimal gland fluid was collected by cannulation. ET-LI was determined with a sandwich-enzyme immunoassay. The reverse transcriptase-polymerase chain reaction (RT-PCR) was employed to determine if there are gene transcripts for prepro ET-1 in tear glands. ET-LI in the tear glands was evaluated using immuno-histochemistry.Results.The tears contained 13.85±3.94 pg/ml (mean±SEM, n = 6) ET-LI and the lacrimal gland fluid had 24.90 + 6.00 pg/ml (n = 6). The plasma contained 0.89 + 0.20 pg/ml (n = 6). Gene transcripts were identified for prepro ET-1 in the lacrimal and Harderian glands. Specific staining for ET-LI was found in the epithelial cells of the ducts of the lacrimal gland and the acinar cells of the Harderian gland.Conclusions.The higher concentrations of ET-LI in the tears and the lacrimal gland fluid than in plasma along with prepro ET-1 gene transcripts in the tear glands suggest that they secrete ET-1.

ISSN:0271-3683    

DOI:10.3109/02713689609003461

出版商:Taylor&Francis    

年代:1996

数据来源: Taylor

摘要:

Purpose.To evaluate the relative contribution of leucine amino-peptidase and aminopeptidase III activities to the total amino-peptidase activity in bovine and human lenses underin vivopH conditions.Methods.Bovine and human lens extracts were fractionated on a Sephadex G-200 column at pH 6.9 and 8.5 and all the fractions were assayed with Leu-pNA and Arg-pNA as substrates atin vivoions pH (6.9) and optimum pH for leucine aminopeptidase, (8.5) The major peptidases were purified and their activities compared with that of LAP and AP III isolated from bovine lens. The ability of bovine and human lens extracts and purified bovine lens LAP and AP III to hydrolyze various peptide bonds in synthetic peptides, VHLPTVEK, bradykinin and Ile-Ser-bradykinin was determined by amino acid analysis of the reaction products.Results.Sephadex G-200 gel chromatography and assay of all the fractions at pH 6.9 showed that the elution volume for the predominant aminopeptidase present in bovine lens extract is the same as that of purified AP III from the same lenses. However, when the assays were done at pH 8.5, the major activity eluting from the Sephadex G-200 column was found in fractions having LAP. A similar study of human lens extracts at pH 6.9 and 8.5 showed one major peak with elution volume corresponding to that of purified bovine lens AP III. The human lens extracts displayed a very low level of LAP activity. The hydrolysis pattern of peptide substrates by AP III paralleled that of bovine and human lens extract at pH 6.9. The X-Pro bond resistant to LAP in peptide substrate, VHLTPVEK was hydrolyzed by AP III as well as lens extracts.Conclusions.Both bovine and human lenses have very low LAP activity compared to AP III activity atin vivopH 6.9. AP III, by its higher activity, broad specificity and its ability to cleave peptide bonds that are resistant to LAP, is likely to play a major role in lens during epithelial cell differentiation into fiber cells and complete hydrolysis of peptides generatedin vivo.

ISSN:0271-3683    

DOI:10.3109/02713689609003462

出版商:Taylor&Francis    

年代:1996

数据来源: Taylor

摘要:

Purpose.The purpose of this study was to determine whether any of the previously identified human corneal epithelial pilus-binding proteins were cytokeratins.Methods.Soluble human corneal epithelial proteins (hcep) were separated by one-dimensional (1-D) and two-dimensional (2-D) gel electrophoresis under reducing conditions and transferred to nitrocellulose membrane tor Western blot analysis. To characterize pilus-binding hcep (major proteins of<21, 38, 45, 66 and 97 kDa and minor proteins, including a 55 kDa protein), blots were immunostained using three anti-keratin antibodies, including Pruss monoclonal antibody (MAb), specific for all classes of IFs, AE5 MAb, specific for a 64 kDa cytokeratin, and J7 polyclonal antibody (PAb), specific for a 55 kDa cytokeratin. In addition, major pilus-binding proteins were cut from 1-D SDS gel. electroeluted, dot blotted onto nitrocellulose membrane, and similarly analyzed. In addition, to further test whether any pilus-binding proteins were cytokeratins, soluble hcep were imniunoprecipitated by MAb XLR-3, a specific anti-pilus antibody, after incubation with bacterial pili. The imniunoprecipitated proteins were separated by SDS-PAGE and transferred onto nitrocellulose membrane. The blotted imniunoprecipitated proteins were immunostained using Pruss MAb and MAb XLR-3.Results.Immunoblots using Pruss MAb showed immunostaining of hcep of approximate molecular weights 45, 48, 55, 62 and 66 kDa. Other immunoblot analysis using AE5 MAb allowed identification of a 66 and a 45 kDa protein in both 1-D and dot blot analysis of eluted hcep. J7 PAb specifically immunostained a 55 kDa protein. In 2-D gel immunoblots, three 55 kDa proteins were immunostained by J 7. Three proteins of molecular weights 45. 55 and 66 kDa, isolated after incubation of hcep and pili by immunoprecipitation with MAb XLR-3, also were positively immunostained by the Pruss MAb.Conclusions.Two of the previously identified major pilus-binding proteins of 45 and 66 kDa are cytokeratins. Additionally, the 55 kDa minor pilus-binding protein is also a cytokeratin and appears to carry different electric charges. Novel approaches such as these provide new insight into the pathogenesis ofP. aeruginosainfection in human cornea, and may lead to improved prevention and treatment of bacterial induced corneal disease.

ISSN:0271-3683    

DOI:10.3109/02713689609003463

出版商:Taylor&Francis    

年代:1996

数据来源: Taylor

摘要:

Purpose.To identify mutations in ornithine aminotransferase (OAT) in seven Japanese families with gyrate atrophy (GA), an autosomal recessive chorioretinal degeneration of the eye caused by a generalized biochemical deficiency in OAT; mutations in the OAT gene have shown a high degree of molecular heterogeneity.Methods.DNA was prepared from patients' fibroblasts and analyzed by polymerase-chain-reaction amplification of the OAT gene sequence, denaturing gradient gel electrophoresis, and direct sequencing for identification of the mutations.Results.Eight different mutations were identified in seven unrelated Japanese GA patients with hyperornithinemia, confirming the high genetic heterogeneity of this disease. Five of these mutations were new, including one causing a pyridoxine-responsive disease, and all eight mutations have been found only in Japanese GA patients. Consistent with some similarity between the Japanese and Finnish populations in genetic isolation and homogeneity, there was a preponderance of homozygous mutations (five out of seven patients) as was previously reported for 16 Finnish GA pedigrees.Conclusions.The eight Japanese OAT mutations represent a group of heterogenous mutations unique to a specific population pool.

ISSN:0271-3683    

DOI:10.3109/02713689609003464

出版商:Taylor&Francis    

年代:1996

数据来源: Taylor

摘要:

Processing of visual information within the retina depends in large measure upon a complement of chemical neurotransmitters which are released at synaptic contacts between individual neurons. Numerous investigators have participated in the identification of many of these transmitters and their assignment to specific neuronal subpopulations. However, it is now clear that the action of each transmitter depends upon the receptor molecules to which it binds. Multidisciplinary studies are underway to characterize these receptors as well as to investigate transporter molecules which may serve not only to inactivate certain neurotransmitters but may also function in their release.

ISSN:0271-3683    

DOI:10.3109/02713689609003465

出版商:Taylor&Francis    

年代:1996

数据来源: Taylor

摘要:

In the manuscript entitled,“Effects of extracellular matrix and Bruch's membrane on retinal outer segment phagocytosis by cultured human retinal pigment epithelium”by Michael V. Miceli and David A. Newsome, which appeared in Volume 15 number 1: January 1996, pages 17-26, a conversion problem occurred. The micron (u,) converted to an m (em).

ISSN:0271-3683    

DOI:10.3109/02713689609003466

出版商:Taylor&Francis    

年代:1996

数据来源: Taylor

ISSN:0271-3683    

DOI:10.3109/02713689609003467

出版商:Taylor&Francis    

年代:1996

数据来源: Taylor