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J F Kuck

Publications and source records attributed to J F Kuck.

At least 19 recordsLinked to original sources
PubMed1994

Actin filament bundles are associated with fiber gap junctions in the primate lens.

A unique association between actin filament bundles and gap junctions in cortical fiber cells of human and monkey lenses was studied with thin-section electron microscopy and immunocytochemistry. Thin-section electron microscopy showed that distinct layers of filament bundles (approximately 55 nm thick) were consistently associated with fiber gap junctions (approximately 16 nm thick) from intermediate to deep cortical regions in both species studied. The filament bundle was composed of 6-8 nm microfilaments which lay along both cytoplasmic surfaces of the junction. Fluorescence microscopy revealed a patchy pattern of F-actin labeling along the fiber cell membranes in the intermediate and deep cortical regions of the lens. The size and distribution pattern of F-actin labeling appear to correlate well with those of filament bundles/gap junctions seen in thin-section electron microscopy. By immunoelectron microscopy, the anti-actin antibody was shown to be localized to filament bundles/gap junctions in the intermediate cortical fibers of human lens, indicating that filament bundles are F-actin in nature. The identical filament bundle/gap junction association was not found in other species examined, including rodent, bird and fish, by the same procedure, suggesting that an association between actin bundles and gap junctions has a special functional role in the primate lens. It is proposed that gap junction-associated actin bundles may provide added structural stability for the primate lens.

Actins↗
PubMed1993

The altricial pigeon is born blind with a transient glycogen cataract.

The lens nucleus of altricial birds contains a large amount of glycogen. It is not known why glycogen in such concentration does not cause a trace of lens opalescence. Here we report that the altricial pigeon is born with a dense nuclear opacity; this opacity has practically disappeared by 4 weeks of age. Thin-section electron microscopy revealed that the opacity was specifically associated with an enormous number of large glycogen aggregates in nuclear fiber cells. These aggregates of various sizes (up to approximately 5 microns) were composed of smaller individual 35-nm beta glycogen particles. In contrast, glycogen aggregates were not seen in nuclear fiber cells of all transparent older lenses. The glycogen aggregates have gradually dissociated into a homogeneous distribution of individual beta particles in the entire cytoplasm of nuclear fibers which accompanies the development of lens transparency. This study suggests that an extensive accumulation of glycogen aggregates in the lens nucleus is the cause of light scattering and opacification. The transparency of the altricial pigeon lens during normal development is therefore regulated by two different forms of glycogen. Precocial birds such as chick have no lens glycogen, therefore never develop a glycogen cataract and have excellent visual acuity upon hatching.

Agglutination↗
PubMed1992

Nature and localization of avian lens glycogen by electron microscopy and Raman spectroscopy.

Electron microscopy confirms the presence of a high concentration of glycogen particles in the lens nuclear region of birds of flying habit such as the ring-neck dove and pigeon. This observation is consistent with Raman spectroscopy. The glycogen particles in the dove lens, which are approximately 35 nm in diameter, are classified as beta type particles. Although this type has been previously characterized by high rates of glycogen turnover in other tissues, its localization in the lens nucleus indicates that it may serve a structural function rather than as a storage depot of carbohydrate in the lens. In a comparative electron microscopy study, glycogen particles were not observed in the chicken lens.

Animals↗
PubMed1991

Resonance Raman detection of a carotenoid in the lens of the deep-sea hatchetfish.

A laser scanning micro-probe has been used to elicit resonance Raman signals from frozen sections of the lens of the deep-sea hatchetfish, Argyropelecus affinis. The signals demonstrate with certainty the presence of a carotenoid and its distribution in the lens. The carotenoid exhibits characteristic resonance Raman vibrational modes at 1551 cm-1 (C = C stretch, v1), 1147 cm-1 (C-C stretch with C-H bend, v2), 2285 cm-1 (2v2) and 2681 cm-1 (v1 + v2), upon excitation at 441.6 nm. Unlike glycogen in the nucleus of dove lens, the carotenoid in the lens of A. affinis occurs at a higher concentration in the cortex, although its presence in the nucleus is established. A study of lenses of varying age showed that carotenoid incorporation is accelerated as the fish grows older and hence its concentration is highest in the cortex. Because of the extremely low concentration of the carotenoid in the nucleus, it was detectable only by the very sensitive resonance Raman technique.

Aging↗
PubMed1991

Near-infrared Fourier transform Raman and conventional Raman studies of calf gamma-crystallins in the lyophilized state and in solution.

We present in this report a detailed structural study of calf gamma-crystallins both in the solid state and in solution by the newly developed technique of near-infrared (IR) Fourier transform (FT)-Raman spectroscopy as well as by the conventional Raman method. In comparison with conventional laser Raman spectroscopy, the near-IR FT-Raman approach exhibits several attractive features such as fluorescence rejection capability, frequency accuracy, and the FT's multiplex and throughput advantages. These distinct characteristics combined form the basis for the particular suitability of FT-Raman in crystallin structural analysis and elucidation. We have thus obtained evidence in support of the view that native calf gamma-II crystallin does not contain a disulfide bond either in the lyophilized state or in solution. In addition, conventional Raman spectra are examined for all four gamma-crystallin fractions. gamma-S, gamma-II, gamma-III, and gamma-IV, and the results indicate a high degree of structural similarities among them. It is also found that the sulfhydryl groups in all four gamma-crystallins are highly resistant to air oxidation and are capable of maintaining their reduced state during isolation in the absence of added reductants or such chelating agents as EDTA.

Animals↗
PubMed1990

Late onset hereditary cataract of the emory mouse. A model for human senile cataract.

The late onset cataract of the Emory mouse has appealed to many investigators as a useful animal model for human senile cataract. It has been the subject of about 15 publications, beginning in 1982. These have explored many features, including histology, chromatography and isoelectric focusing of the crystallins, enzyme profiles, amino acid and ion transport, membrane studies including changes in MP24 and MP26, analysis for a number of biochemical constituents, and its use as an assay system for testing the effect of anticataractogenic drugs and dietary restriction. These investigations have not uncovered a single metabolic lesion marked enough to be considered an important cause of this cataract. There is some evidence that the effect of oxidation may be a major factor; likewise there is evidence for faulty protein synthesis. In many cases, the changes in cataractogenesis appear to be accelerated aging changes. For this reason, any study of this cataract must employ age-matched controls of the cataract-resistant strain. A recent discovery is the finding that many earlier studies used a mixture of both early and late-onset forms, accounting for the wide variability in analytical results. The two substrains may have somewhat different applications in cataract research. Thus, the availability of these two substrains should extend the usefulness of this animal model.

Animals↗
PubMed1990

Alterations of urea-insoluble membrane fraction, MP26, of Emory mouse lenses in aging and cataractogenesis.

Purified lens fiber membrane fractions from Emory mouse lenses and cataract-resistant control lenses were compared by SDS-PAGE. The differences in polypeptide patterns were determined for three ages. There was a striking alteration in MP24/MP26 ratio during aging and cataractogenesis which appears to be due to a normal age-dependent conversion of MP26 to MP24, and which is accelerated during cataractogenesis.

Aging↗
PubMed1989

Distribution of two metabolically related fluorophors in human lens measured by laser microprobe.

Automated Raman microprobe spectrometry revealed the distribution of a major fluorophor, 3-OH-L-kynurenine-O-beta-glucoside, in human lenses from 0.38 to 71 yr. A three-dimensional perspective grid map with fluorescence intensity as the third dimension shows maximum fluorescence in the infant lens nucleus. At 12 yr the fluorescence peak is broadened and a toroid-shaped maximum occurs also in the outer cortex, creating a toroid-shaped minimum between the two maxima. By 71 yr the nuclear maximum is lower but a new (green) fluorophor (excitation 488 nm: emission 530 nm) has appeared as a toroidal maximum in the same location as the blue minimum, suggesting the conversion of the blue fluorophor to the unidentified green fluorophor.

Adolescent↗
PubMed1989

Galactose-induced cataract in rat: Raman detection of sulfhydryl decrease and water increase along an equatorial diameter.

Raman spectroscopy shows that maturation of galactose cataract greatly increases the water signal (at 3417 cm-1) which is correlated with the inbibition of water in the lens. The maximum water: protein ratio (expressed as Raman intensity ratio I3417:I2936) occurs at the peripheral cortex (i.e. approximately 4.7), which is much higher than the ratios found in Emory cataract (approximately 0.3) and in cac-strain mouse cataract (approximately 0.5). It is demonstrated that Raman measurement of the intensity ratio I3417:I2936 is a more sensitive way to reflect increase of water in cataract, compared to water concentration (percentage of wet weight of the lens). The small decrease in the sulfhydryl profile along an equatorial diameter is attributed to the concentration decrease in glutathione. There is no spectroscopic evidence for extensive disulfide bond formation associated with galactosemic cataractogenesis in rat. There is an increase in the tyrosine I832:I858 ratio (normal 1.74; cataract 3.43), indicating a strengthening of the phenolic hydrogen bond, a change which has been found in Raman spectra of all cataracts studied. A comparison of the Raman spectra of normal lenses and mature cataracts reveals no change in conformation of the protein backbone.

Animals↗
PubMed1989

Moderate caloric restriction delays cataract formation in the Emory mouse.

Eye lens senile cataract is a major cause of blindness, affecting the elderly in particular. The etiology of the disorder has been elusive, and attempts to delay the onset of senile cataracts have been unsuccessful. The need for more information is underscored by epidemiologists who estimate that the ability to delay cataract formation in humans by only 10 years would eliminate the need for 50% of the cataract extractions performed annually in the United States. The Emory mouse provides the best model for human senile cataracts. Feeding Emory mice a diet that was restricted in calories by approximately 21% delayed the onset of cataracts. This is the first study that demonstrates in vivo the delay of senile-type cataracts. In these animals, aging and cataracts are associated with diverse changes in the proportion of various proteins (particularly 21, 22, 31-34 kDa) and with transformation of proteins from a soluble to an insoluble state. In advanced cataracts, there is a loss of total protein. Within a cataract grade, there is no difference between restricted and nonrestricted animals in relative proportion of specific lens proteins or in amounts of total or soluble proteins. The transition from a clear to cataractous lens appears when the soluble-to-total protein ratio falls below about 0.58. The exclusive use of gamma-crystallin as an indicator of lens viability is questioned. To the extent that cataract formation is due to lens protein oxidation and/or an inability to proteolytically remove damaged protein, it would appear that caloric restriction results in enhanced protection against lens oxidative stress or in prolonged proteolytic function.

Aging↗
PubMed1989

Establishment of lens epithelial cell lines from Emory and cataract resistant mice and their response to hydrogen peroxide.

We determined the conditions required for the establishment of lens epithelial cell lines from individual Emory and age matched cataract-resistant (CR) mice, and investigated the response of these cells to hydrogen peroxide. The technique described here permits the establishment of mouse lens epithelial cell lines from individual animals and provides an opportunity to study changes in epithelial function that precede and accompany cataract formation and aging. Capsules with lens epithelial cells were isolated from 1, 6 month, and 1.5-2 year old Emory and CR mice and cultured in minimal essential medium (MEM) containing 4% heat inactivated fetal bovine serum and 4% heat inactivated rabbit serum. Seeding efficiency at 3 hours was approximately 83% for all lines, doubling time was 22-24 hours, and the shape of the growth curves was comparable for Emory and CR mice from each age group. A three hour exposure of Emory and CR mouse lens epithelial cells from older animals to a constant level of 0.02 mM hydrogen peroxide or to an initial concentration of 0.01, 0.03, or 0.05 mM hydrogen peroxide resulted in a delay in growth. The delay in cell proliferation was decidedly more pronounced in lens epithelial cells from Emory mice. Lens epithelial cells from cataractous mice appear to be more sensitive to oxidative insult than their CR counterparts.

Aging↗
PubMed1989

The Emory mouse cataract: increased accumulation of calcium during cataractogenesis.

Total calcium and total protein contents have been determined in Emory mouse cataracts from 6 to 19 months of age and also in age-matched Cataract-resistant control lenses. The normal lens calcium is about 0.006 micrograms/mg fresh lens weight; in cataracts the value increases from about 0.02 in beginning cataracts to 0.4 in severe cataracts. Calcium does not increase with age in control lenses. Elevation of calcium levels never precedes initial cataractous changes and is most probably a secondary change. This mouse cataract, unlike human senile cataracts, invariably accumulates calcium and the magnitude is roughly proportional to the severity of cataract. It appears to be a simpler and more homogenous type than human cataract and is therefore more suitable for biochemical studies.

Aging↗
PubMed1988

Raman spectroscopic evaluation of aging and long-wave UV exposure in the guinea pig lens: a possible model for human aging.

The laser Raman optical dissection technique makes it possible to study individual points of minute volumes (2 X 10(-3) microliter) in the intact living lens in vitro. This technique was used to measure the sulfhydryl and disulfide content of 21 distinct points along the visual axis of the guinea-pig lens after aging and long-wave ultraviolet exposure (9-month duration in vivo). To facilitate comparison between different lenses, data was compiled as the intensity ratio of sulfhydryl (2580 cm-1) to a protein reference signal (2731 cm-1) or disulfide (508 cm-1) to phenylalanine (622 cm-1). These 21 ratios for each experiment were plotted as a function of the distance of the point from the nuclear center of the lens to give a visual axis profile. From these profiles we have found that the loss of sulfhydryl can be accelerated in the guinea-pig lens by in vivo ultraviolet exposure (353 nm peak from an incoherent source) for nine months. There is also a subsequent uniform increase in the disulfide content across the visual axis after UV exposure suggesting a direct sulfhydryl to disulfide conversion in the guinea-pig lens.

Aging↗
PubMed1988

Automated laser-scanning-microbeam fluorescence/Raman image analysis of human lens with multichannel detection: evidence for metabolic production of a green fluorophor.

A laser-microprobe fluorescence/Raman spectrometer with a 700-channel detector has been constructed and applied to the collection of data on the distribution of a green fluorophor throughout the exposed area of a human lens sectioned along the visual axis. The area (approximately 6.5 X 9.5 mm) covering the lens section was scanned automatically by the microprobe programmed to measure the fluorescence intensity at 1200 data points. The spectrometer output was accumulated in a microcomputer and displayed as a three-dimensional perspective view showing the fluorescence intensity at each point on the grid. The method permits the precise and detailed mapping at high resolution of the spatial distribution of a fluorophor or Raman-emissive constituent in a plane of the frozen lens to give results not obtainable by any other feasible procedure. The green fluorophor (441.6 nm, excitation wavelength; 520 nm, peak emission wavelength) has a distribution indicating a metabolic rather than a photochemical mode of production. Moreover, the lower level of fluorophor in the anterior segment suggests the existence of mechanisms in the anterior cortex (including the epithelium) that reduce significantly the accumulation of fluorophor. Such distribution studies are invaluable in clarifying metabolic interrelationships among the different zones of the lens, including especially photochemical reactions postulated to involve the effect of daylight on the lens in human subjects.

Aged↗
PubMed1988

The Emory mouse cataract: the effects on cataractogenesis of alpha-tocopherol, penicillamine, triethylenetetramine, and mercaptopropionylglycine.

The Emory mouse develops a late-onset hereditary cataract bearing some resemblances to human senile cataract. It was used as a model system for testing the effects of several drugs expected to have anticataractogenic potential. A low level of added dietary alpha-tocopherol had only a marginal effect. Penicillamine increased lens soluble protein, a good index of lens viability. Triethylenetetramine was too toxic to permit satisfactory treatment. Mercaptopropionylglycine produced several positive effects including a retardation of cataract at 6 months of age; parameters which increased under drug treatment were lens weight, soluble protein content and protein sulfhydryl, but not glutathione. There was no effect on the total calcium concentration.

Animals↗