Characterization and functional performance of a commercial human conjunctival epithelial cell line

The conjunctiva is a complex tissue that covers the eye beginning at the corneal limbus and extending over the inner surfaces of the eyelids. Due to its important functions in maintaining the health of the ocular surface, adequate in vitro models of conjunctival structure and function are essential to understand its roll in different pathologies. Because there is scarcity of human conjunctival tissue that can be used in research, cell lines are often the only option for initial studies. An immortalized human conjunctival epithelial cell (IM-HConEpiC) line is now commercially available; however, it is not very well characterized. In this study, we have developed a new protocol to culture these cells without the use of collagen-coated culture surfaces, but with a defined cell culture medium. We characterized IM-HConEpiCs cultured under these conditions and corroborated that the cells maintained a conjunctival epithelial phenotype, including acidic and neutral mucins, junctional proteins E-cadherin and zonula occludens 1, and expression of CK8 and CK19, among others. In addition, we analyzed the response to oxidative stress and inflammatory stimuli and found that IM-HConEpiCs respond as expected for conjunctival epithelial tissue. For instance, cells exposed to oxidative stress increased the production of reactive oxygen species, and that increase was blocked in the presence of an antioxidant agent. In addition, after stimulation with TNF-α, IM-HConEpiCs significantly increased the production of IL-1β, IL-6, IL-8, and IP-10. Therefore, with this study we conclude that IM-HConEpiCs can be a useful tool in functional studies to determine the response of the conjunctiva to pathological conditions and/or to test new therapeutic strategies.

Improved ocular delivery of quercetin and resveratrol: A comparative study between binary and ternary cyclodextrin complexes

The number of patients affected by Dry Eye Disease (DED) had notably increased worldwide, addressing the need of novel therapeutic approaches. Polyphenols, quercetin (QUE) and resveratrol (RSV) show necessary antioxidant and anti-inflammatory properties to manage DED, but their application as topical eyedrops is restricted by low aqueous solubility and low chemical stability. Cyclodextrins (CD) are widely used to improve physicochemical characteristics of drugs. Consequently, the aim of this study was to make a comparison between binary complexes with quercetin, resveratrol and cyclodextrins and tertiary complexes adding hyaluronic acid (HA). Both complexes were able to enhance solubility and stability of QUE and RSV. AFM imaging and DLS measurements disclose the formation of spherical nanoaggregates within tertiary complexes of both QUE and RSV with mean diameters of 103 and 82 nm. Neither complex demonstrated cytotoxic effect in in vitro studies in corneal (HCE) and conjunctival (IM-ConjEpi) cell lines. In HCE cells, complexes containing QUE or RSV at their highest concentrations were able to scavenge more than 95 % of the ROS that were produced intracellularly (p < 0.005). Similar response was observed with IM-ConjEpi cells. The antioxidant effect was maintained in the complexes with HA. This confirmed their potential as viable topical treatment for DED.

Potential Ophthalmological Application of Extracts Obtained from Tuna Vitreous Humor Using Lactic Acid-Based Deep Eutectic Systems

A green technique was developed to extract hyaluronic acid (HA) from tuna vitreous humor (TVH) for its potential application in managing dry eye disease. Deep eutectic solvents (DES) were used to extract HA and were synthesized using natural compounds (lactic acid, fructose, and urea). The DES, the soluble fraction of TVH in DES (SF), and the precipitated extracts (PE) were evaluated for their potential use in dry eye disease treatment. In vitro experiments on human corneal epithelial cell lines and the effect on dry eye-associated microorganisms were performed. The influence of the samples on the HCE viability, their intracellular reactive oxygen species (ROS) scavenging capacity, inflammatory response, and antimicrobial properties were studied. According to the results, all samples displayed an antioxidant effect, which was significantly higher for PE in comparison to SF. Most of the tested samples did not induce an inflammatory response in cells, which confirmed the safety in ophthalmic formulations. In addition, the DES and SF proved to be efficient against the studied bacterial strains, while PE did not show an antimicrobial effect. Hence, both DES and SF at defined concentrations could be used as potential compounds in dry eye disease management.

Ocular Delivery of Polyphenols: Meeting the Unmet Needs

Nature has become one of the main sources of exploration for researchers that search for new potential molecules to be used in therapy. Polyphenols are emerging as a class of compounds that have attracted the attention of pharmaceutical and biomedical scientists. Thanks to their structural peculiarities, polyphenolic compounds are characterized as good scavengers of free radical species. This, among other medicinal effects, permits them to interfere with different molecular pathways that are involved in the inflammatory process. Unfortunately, many compounds of this class possess low solubility in aqueous solvents and low stability. Ocular pathologies are spread worldwide. It is estimated that every individual at least once in their lifetime experiences some kind of eye disorder. Oxidative stress or inflammatory processes are the basic etiological mechanisms of many ocular pathologies. A variety of polyphenolic compounds have been proved to be efficient in suppressing some of the indicators of these pathologies in in vitro and in vivo models. Further application of polyphenolic compounds in ocular therapy lacks an adequate formulation approach. Therefore, more emphasis should be put in advanced delivery strategies that will overcome the limits of the delivery site as well as the ones related to the polyphenols in use. This review analyzes different drug delivery strategies that are employed for the formulation of polyphenolic compounds when used to treat ocular pathologies related to oxidative stress and inflammation.

[Chlamydia trachomatis and acute pelvic inflammatory disease]

The incidence of Chlamydia trachomatis infection in women with acute pelvic inflammatory disease has been studied. Chlamydia trachomatis was isolated in 20 (35.71%) of 56 examined women. In all women with positive isolation, the infection was also confirmed serologically.

[Detection of parvovirus B19 in the blood of patients using DNA hybridization]

DNA assay was used in detection of parvovirus B19. The sera of 63 patients were examined and the presence of DNA virus was found in two samples.

[Typing of rotavirus strains using electrophoresis]

Polyacrylamide gels electrophoresis was used in the analysis of rotavirus genome strains isolated in the regions of Belgrade and Nis in the period 1987-1991. Ten samples were examined and the same type of motility was found.

[Surgical treatment of paralytic convergent strabismus using a modification of Jensen's method]

Surgical treatment of paralytic convergent strabismus using the modified Jensen's is method was performed in 35 patients. The full success (orthophoria) was achieved in 51.5% and satisfying (approximately orthophoria) in 25.7% of cases. The six-year follow up of patients showed that surgical effect was permanent in 71.4% of cases. The most common cause of paralytic convergent strabismus has been trauma (71.4%), and, that, traffic accidents in 45.7%. According to communications and available literature this modified treatment of paralytic convergent strabismus for the first time in Yugoslavia has been applied in the Military Medical Academy.

[Detection of human papilloma viruses using in situ hybridization]

First experiences in the diagnosis of human papilloma viruses are reported. The method of in situ hybridization was used together with biotin tests for types of HPV: 6/11, 16/18 and 31/33/51. The study was performed on the preparations of of the cervix tissue with displasmic proliferation and laryngeal papilloma tissues. There have been examined 37 specimens: in 6 were found sequence of HPV genoma for types 6/11 and in 1 specimen for types 16/18 and 31/33/51/.

[Chlamydia trachomatis and Reiter's syndrome]

Results of the study of incidence of chlamydia trachomatis infection in patients with Reiters syndrome are presented. Chlamydia trachomatic was isolated from the uretral smear in 12 (34.28%) of 35 patients with Reiter's syndrome. In the group of patients with other rheumatologic diseases Chlamydia trachomatis was isolated in 2 (5.13%) of 39 patients. In all patients with negative isolation, infection was confirmed serologically also and in some patients with negative isolation it was also proved.

[Importance and diagnosis of Epstein-Barr virus infection]

The 103 serum samples have been examined for the presence of the specific antibodies against Epstein-Barr virus (EBV): IgG and IgM antibodies to viral capsid antigen (VCA), antibodies to nuclear antigen (EBNA) and antibodies to early antigen (EA). Sixty nine studied sera belonged to patients with suspected infective mononucleosis (IM) while other sera were sent with the diagnosis which could be associated with EBV infections. The results obtained have suggested the necessity of examinations of EBV markers in all states suspected of EBV infection.

[The significance of determination of streptococcal deoxyribonuclease B antibody titers]

Results obtained by testing 266 sera using antistreptolysin O (ASTO) and antideoxyribonuclease B (ADNB) tests were compared. Upper limit of the normal ADNB titer was determined for population by analysing titer levels in 258 samples taken from healthy subjects (blood donors) and it was 225 IU/ml. Increased titer of one or both antibodies was found in 76 (29%) sera-ASTO and (or ADNB-positive sera being the much larger number than the positive sera number obtained by ASTO test) 40-15% 7. This confirms necessity of the ADNS test application in all patients with normal ASTO titer.

[Acute gastroenteritis of viral etiology]

Retrospective analysis of own experiences and investigations concerning the role of the viral etiology in acute gastroenteritis were presented. Stools of children and soldiers with acute gastroenteritis were examined by electron microscopy. The most frequent causative agents were rotaviruses and much less frequently found were other viral particles of: coronaviruses, adenoviruses, Norwalk-like viruses, astroviruses, caliciviruses and "small round viruses".

[Preparation of a DNA probe for thermolabile toxin and its use in the identification of enterotoxic Escherichia coli]

Enterotoxic Escherichia coli (ETEC) having a gene for thermolabile toxin were identified by the hybridization technique. HindIII-SmaI fragment with 423 basic pairs (dp) including subunit portions A and B of the gene for thermolabile toxin (elt) was used as the DNA probe.

[Neutralizing antibodies to Coxsackie virus group B 1986-1988]

Presence of neutralizing antibodies to Coxsackie B viruses (CBV) 1-5 were examined in 2885 human sera by the neutralization test. The most frequently detected antibodies were to B4 viruses (in 1495 sera--51.82%) and to B3 (1371--47.52%). Antibodies to other serotypes were found in lower percentage: to B1 in 387 samples (13-41%), to B2 in 404 sera (14%) and in B5 in 332 sera (11.5%). Presence of neutralizing antibodies to human CBV in heart diseases were also analysed in 67 serum pairs. In this group of examinees the antibody titer dynamics was found in 41.79% sera.

The association of enterotoxigenic and enteropathogenic Escherichia coli and other enteric pathogens with childhood diarrhoea in Yugoslavia

The presence of enterotoxigenic and enteropathogenic Escherichia coli (ETEC and EPEC, respectively) was investigated in stool specimens of 1082 preschool children with diarrhoea and in stools of 335 healthy controls in localities in southern Yugoslavia, as well as in 566 children with diarrhoea and in 231 controls living in northern part of the country, during the seasonal peak (August-November) of enteric diseases in 1986. ETEC were found in 114 (10.5%) children with diarrhoea and in 14 (4.2%) controls (P less than 0.001) in the southern part, and in 26 (4.6%) ill children and one (0.4%) well child (P less than 0.005) in the northern part of Yugoslavia. EPEC were isolated from stools of 85 (7.9%) children with diarrhoea and of 14 (4.2%) well children (P less than 0.05) in localities of southern Yugoslavia, and from 22 (3.9%) ill children and from 10 (4.3%) controls in northern Yugoslavia. Nineteen EPEC strains expressed localized adherence to HEp-2 tissue culture cells; all were isolated from stools of ill children. In southern Yugoslavia, where other enteropathogens were sought, the most commonly found agents in ill children were shigellae (17.5%), rotavirus (11.8%), ETEC, and EPEC. Potential pathogens were detected in 44.5% cases of sporadic diarrhoea and in 15.8% controls. This study revealed that ETEC were associated with acute diarrhoeal disease in Yugoslav preschool children. On the other hand, the diagnosis of EPEC-diarrhoea by routine determination of serogroup established the association of these agents with sporadic diarrhoea only in the 0-2 years age categories in all investigated localities. In the less developed southern part of Yugoslavia bacteria were the predominant causative agents of enteric illness during the seasonal peak of this disease.

[Analysis of herpes simplex virus DNA using restriction endonucleases]

DNA of herpes simplex virus was analysed by restriction endonucleases EcoRI, BgII and HindIII. By this method it is possible to differentiate type 1 and type 2 of viruses. DNA of herpes simplex virus was prepared according to the method of Kinnunen and his collaborators which is described in detail.