Featured Article: Inhibition of diabetic cataract by glucose tolerance factor extracted from yeast.

Diabetes leads to many complications; among them is the development of cataract. Hyperglycemia brings to increased polyol concentration in the lens, to glycation of lens proteins, and to elevated level of ROS (Reactive Oxygen Species) causing oxidative stress. The glucose tolerance factor (GTF) was found by several groups to decrease hyperglycemia and oxidative stress both in diabetic animals and humans.

Simulation of heat exposure and damage to the eye lens in a neighborhood bakery.

Epidemiological studies indicated a link between high temperature environment and cataract. The purpose of the study was to investigate if the high temperature in neighborhood bakeries can cause damage to the eye lens. Measurements were done to determine the temperature and exposure time in the neighborhood bakeries during a workday.

Non-thermal electromagnetic radiation damage to lens epithelium.

High frequency microwave electromagnetic radiation from mobile phones and other modern devices has the potential to damage eye tissues, but its effect on the lens epithelium is unknown at present. The objective of this study was to investigate the non-thermal effects of high frequency microwave electromagnetic radiation (1.1GHz, 2.

Desferrioxamine and zinc-desferrioxamine reduce lens oxidative damage.

Our purpose was to investigate the quality and morphology of cultured bovine lenses after exposure to hyperbaric oxygen (HBO) in the presence or absence of desferrioxamine (DFO) or zinc-desferrioxamine (Zn-DFO). Intact bovine lenses were cultured and exposed to HBO of 100% oxygen at 2.5 ATA for 120 min.

[Oxygen effect on ocular lens].

Background: Cataract is the leading cause of preventable blindness worldwide. Clinical observations and laboratory results have shown that oxygen has a possible toxic role in cataract formation.

Aim: The aim of the present study was to demonstrate, measure and characterize the damage caused to bovine lenses in organ culture as a result of their exposure to hyperbaric oxygen pressure.

Localized effects of microwave radiation on the intact eye lens in culture conditions.

A novel experimental system was used to investigate the localized effects of microwave radiation on bovine eye lenses in culture for over 2 weeks. Using this setup, we found clear evidence that this radiation has a significant impact on the eye lens. At the macroscopic level, it is demonstrated that exposure to a few mW at 1 GHz for over 36 h affects the optical function of the lens.

Long-term lens organ culture system with a method for monitoring lens optical quality.

The Scan Tox System is a method for monitoring lens optical quality (focus or lack of focus) in culture conditions, which mimic conditions inside the eye. The ocular lens is an ideal organ for long-term culture experiments because it has no direct blood supply and no connection to the nervous system. The Scan Tox System makes it possible to keep lenses for long-term studies of up to a few weeks.

Long-term lens organ culture system to determine age-related effects of UV irradiation on the eye lens.

Aging of the eye lens represents the life-long accumulation of damage. Factors responsible for age-related cataract are unknown because medical evaluations of aged populations demonstrate a wide range of systemic diseases and medical disorders. There are some main suspected factors, which may contribute to accumulated age-related damage in the eye lens.

Effects of UV-A irradiation on lens morphology and optics.

Epidemiological studies have indicated that ultraviolet radiation (UVR) is one of the main factors leading to senile cataract formation. We investigated morphological changes in the eye lens caused by UVR-A. Twenty three pairs of lenses obtained from 23 one-year-old calves were used for this study.

Lenticular oxygen toxicity.

Purpose: To investigate the possible toxic effect of oxygen on lenses in an organ culture.

Methods: Bovine lenses were exposed to four different combinations of ambient pressure and oxygen concentration in an organ culture throughout a 7-day period. Lens transparency, histology, enzymatic activities, and photomicrographs were compared in study and control groups.

UV-A-related alterations of young and adult lens water-insoluble alpha-crystallin, plasma membranous and cytoskeletal proteins.

The damaging effects of UV-A irradiation on lens water-insoluble alpha-crystallin, plasma membranous and cytoskeletal proteins derived from bovine lenses were studied. Young and adult bovine lenses were kept viable for 2 months in organ culture. After 24 h of incubation they were irradiated, and analyses of the proteins by one-dimensional and two-dimensional gel electrophoresis followed by Western blotting were carried out at several time intervals.

In vitro filament-like formation upon interaction between lens alpha-crystallin and betaL-crystallin promoted by stress.

Purpose: To determine whether alpha-crystallin is capable of forming filament-like structures with other members of the crystallin family.

Methods: Water-soluble crystallins were isolated from calf lenses and fractionated into alpha-, betaH-, betaL-, and gamma-crystallins according to standard procedures. Chaperone-like activity of alpha-crystallin was determined in control and UV-A-irradiated lenses by the heat-induced aggregation assay of betaL-crystallin.

Analysis of UVA-related alterations upon aging of eye lens proteins by mini two-dimensional polyacrylamide gel electrophoresis.

This study is a first approach to identify UVA-related alterations in situ of bovine eye lens proteins from the water-soluble and urea-soluble fractions upon aging. The fractions were obtained from irradiated long-term organ culture lenses and analyzed by mini two-dimensional gel electrophoresis. This micropreparative method followed by computer analysis allows high resolution and separation of microgram quantities of proteins and to detect spots which arose as a consequence of irradiation.

Effect of UV-A light on the chaperone-like properties of young and old lens alpha-crystallin.

Purpose: To study the damaging effect of UV-A irradiation on the chaperone-like properties of alpha-crystallin and the subsequent recovery process of young and old bovine lenses.

Methods: Young and old bovine lenses were kept in organ culture. After 24 hours of incubation they were irradiated with UV-A at 365 nm, and optical quality measurements were performed during the experiments (192 hours).

Effects of UV-A radiation on lens epithelial NaK-ATPase in organ culture.

Purpose: To investigate the mechanisms involved in the damage caused by UV-A irradiation at 365 nm on the eye lens.

Methods: Bovine lenses obtained from animals 1 to 5 years of age were placed in specially designed organ culture chambers for preincubation. Twenty-four hours later, the lenses were irradiated by 33 J/cm2 UV-A at 365 nm.

Transglutaminase involvement in UV-A damage to the eye lens.

Solar radiation is believed to be one of the major environmental factors involved in lens cataractogenesis. The purpose of the study was to investigate the mechanisms by which UV-A at 365 nm causes damage to the eye lens. Bovine lenses were placed in special culture cells for pre-incubation of 24 hr.

Long-term organ culture system to study the effects of UV-A irradiation on lens transglutaminase.

The purpose of the study was to investigate the mechanisms by which UV-A at 365 nm causes damage to the eye lens. Bovine lenses were placed in special culture cells and were oriented so that the anterior surface faced the incident UV-A radiation source. The lenses were maintained in the cells during irradiation.

Recovery of lens optics and epithelial enzymes after ultraviolet A radiation.

Purpose: To establish the mechanism by which ultraviolet A (UVA) radiation causes irreversible damage to the eye lens.

Methods: The authors irradiated 223 bovine lenses in organ culture with 22.4, 33.

Influence of 17 beta-estradiol and progesterone on rat ocular lens.

The effect of 17 beta-estradiol and progesterone on ocular lens in rats and untreated controls was studied. In the treated lenses, the activity of hexokinase and glucose-6-phosphate dehydrogenase remained unchanged. The activity of aldolase was increased in 18- and 20-month-old lenses as compared to controls.

Long-term organ culture system to study the effect of UV-radiation on lens enzymes.

Environmental factors such as solar radiation and drug treatment are potential cataractogenic agents. It is suggested that their damaging effects accumulate with age. The purpose of the study was to isolate the effect of one factor (UV-radiation) and find out the mechanism by which UV radiation causes damage to the eye lens.

DL-propranolol inhibits lens hexokinase activity and affects lens optics.

A clinico-biochemical study indicated that the beta-blocker DL-propranolol may affect human lens epithelial hexokinase (HK) activity. In that study five key enzymes were analysed in 192 freshly excised human lens epithelia obtained during cataract surgery. In a large number of patients the epithelial HK was found to be inactive.

Enzyme activities and crystallin profiles of clear and cataractous lenses of the RCS rat.

Royal College of Surgeons (RCS) rats have hereditary retinal degeneration in association with posterior subcapsular opacities. Cataract formation is thought to be correlated with an increase in lipid peroxidation products in the vitreous (Zigler and Hess, 1985). In order to examine the possibility that parallel changes in enzyme activity are occurring within the lens, we analysed the activity of four key enzymes and the crystallin protein profile.

Effect of hydrogen peroxide, DL-propranolol, and prednisone on bovine lens optical function in culture.

Lens refractive function was monitored during long-term bovine lens culture experiments in which low concentrations of potentially damaging agents were added to the culture media. The agents tested were the drugs DL-propranolol and prednisone, and hydrogen peroxide. A computer-driven scanning laser system was used to monitor lens focal length during culture.

Localization of denatured enzyme molecules in rat lenses.

Immunohistochemical localization of altered enzyme molecules was detected by the use of antibodies to denatured enzymes (ADE) conjugated with fluorescein. Denatured aldolase, glucose 6-phosphate dehydrogenase and superoxide dismutase are mostly located in the subcortical region and in the nucleus of the rat lens. In the nuclear fibres the enzyme is located near the membrane of the fibres.