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Abstract Background Small non-coding RNAs (smRNAs) are known to have major roles in gene regulation in eukaryotes. In plants, knowledge of the biogenesis and mechanisms of action of smRNA classes including microRNAs (miRNAs), short interfering RNAs (siRNAs), and trans-acting siRNAs (tasiRNAs) has been gained mostly through studies with Arabidopsis. In recent years, high throughput sequencing of smRNA populations has enabled extension of knowledge from model systems to plants with larger, more complex genomes. Soybean (Glycine max) now has many genomics resources available including a complete genome sequence and predicted gene models. Relatively little is known, however, about the full complement of its endogenous smRNAs populations and the silenced genes. Results Using Illumina sequencing and computational analysis, we characterized eight smRNA populations from multiple tissues and organs of soybean including developing seed and vegetative tissues. A total of 41 million raw sequence reads collapsed into 135,055 unique reads were mapped to the soybean genome and its predicted cDNA gene models. Bioinformatic analyses were used to distinguish miRNAs and siRNAs and to determine their genomic origins and potential target genes. In addition, we identified two soybean TAS3 gene homologs, the miRNAs that putatively guide cleavage of their transcripts, and the derived tasiRNAs that could target soybean genes annotated as auxin response factors. Tissue-differential expression based on the flux of normalized miRNA and siRNA abundances in the eight smRNA libraries was evident, some of which was confirmed by smRNA blotting. Our global view of these smRNA populations also revealed that the size classes of smRNAs varied amongst different tissues, with the developing seed and seed coat having greater numbers of unique smRNAs of the 24-nt class compared to the vegetative tissues of germinating seedlings. The 24-nt class is known to be derived from repetitive elements including transposons. Detailed analysis of the size classes associated with ribosomal RNAs and transposable element families showed greater diversity of smRNAs in the 22- and 24-nt size classes. Conclusions The flux of endogenous smRNAs within multiple stages and tissues of seed development was contrasted with vegetative tissues of soybean, one of the dominant sources of protein and oil in world markets. The smRNAs varied in size class, complexity of origins, and possible targets. Sequencing revealed tissue-preferential expression for certain smRNAs and expression differences among closely related miRNA family members.

A comparison was made of soluble 14C-gentamicin ophthalmic inserts with drop, ointment, and the subconjunctival routes of administration. The insert is a solid, solubilizable collagen polymer containing 14C-gentamicin. We compared the levels of 14C-gentamicin in the rabbit tear film and in multiple corneal and scleral biopsies to determine which route of administration gave the best results. The wafer route of administration gave the highest tear film and tissue concentration of drug. The tear film concentration by subconjunctival injection was surprisingly low. Soluble collagen inserts offer a new method of delivering high doses of gentamicin in infected corneal tissue in a convenient and atraumatic fashion.

A case of retrocorneal fibrous membrane is reported in a patient who underwent cataract extraction and experienced a postoperative hyphema. A distinctive straw-colored appearance to the membrane was due to blood staining. A penetrating keratoplasty with extensive anterior segment surgery restored the eye to useful vision. The penetrating keratoplasty specimen disclosed an unusual double-layered retrocorneal fibrous membrane, produced in part by a vascularized fibrous ingrowth and also by fibroblastic transformation of the corneal endothelial cells.

Sequential extraction of bovine corneal homogenates with aqueous 0.154M NaCl, 0.5M NaCl and 3M guanidine HCl revealed the presence, in the two sodium chloride extracts, of trypsin inhibitory factors. Upon gel-filtration chromatography of the o.5M NaCl soluble corneal material on Sephadex G-75, two peaks with trypsin inhibitory activity were resolved. One peak was eluted in the void volume, whereas a second peak had mobility corresponding to a molecular weight fraction much lower than, and therefore distinct from, alpha 1-antitrypsin inhibitor. The possible implication of this inhibitory factor in the pathogenesis of corneal ulceration is briefly discussed.

This case report describes acute unilateral calcium deposition in the central cornea of a uremic patient with corneal exposure. A mechanism of calcium deposition is discussed. It is suggested that a high calcium-phosphorus product, combined with local factors secondary to injury of the exposed corneal epithelial cells, helped to trigger rapid and dense calcification. Details of the removal technique are presented. Constant irrigation of freshly prepared chelating agent combined with vigorous and frequent massage of residual deposits is necessary to completely remove dense concentrations of calcium.

Two patients underwent renal transplantation for what was thought to be glomerulonephritis and chronic pyelonephritis. The diagnosis of Fabry's disease was made as an incidental finding during an ophthalmologic consultation for evaluation of blurred vision. These two cases illustrate the usefulness of an eye examination in the correct diagnosis in patients with the multisystem complaints of Fabry's disease. The correct diagnosis was extremely important in understanding the other manifestations of this disease in the affected patient and in the genetic counseling of the family.

This case report describes the clinical and pathological characteristics of an intrastromal epithelial corneal cyst. This lesion tends to occur after relatively minor trauma, in younger patients, and is a slowly progressive disorder that develops over many years. The eye shows no signs of inflammation. The cyst typically appears opalescent but may be characterized by a fluid level. Pathologically, the cyst cavity is lined by cells with features similar to those of limbal corneal eplithelium. Treatment consists of removal or destruction of the epithelial cells lining the cavity.

Very recent studies indicate that a primitive immune system plays an important role in resisting herpesvirus infections in the mouse. This system appears to be reflected by the NK cell assay and preliminary data suggest that this test reflects resistance in man to herpesvirus infections. We propose that ths system may be responsible for resistance to reactivated herpesvirus infections and its suppression might result in clinically apparent disease. Studies in our laboratory are currently aimed at evaluating this possibility.

The onset of bilateral necrotising scleritis and marginal corneal ulceration after cataract surgery are described in a patient with diffuse vasculitis syndrome. The finding of immune complexes in this patient's tissue biopsy suggests that they are the cause of a localised primary vasculitis triggered by surgical inflammation. Clinically, this patient's marginal corneal ulceration preceded the scleral necrosis. A past history of orbital inflammation may have been due to a posterior scleritis. The corneal ulcerations responded to conjunctival debridement and steroids. The scleral necrosis was unresponsive to the 2 anti-inflammatory preparations tried, and the patient eventually went into remission while off all treatment.

Endophthalmitis occurred three months following completion of therapy for documented staphylococcal septicemia in two patients on long-term hemodialysis. The indolent course of the endophthalmitis, and its excellent response to systemic and subconjunctival antibiotics and subconjunctival and topical corticosteroid therapy, suggest the possibility that the acute fulminating clinical course of metastatic bacterial endophthalmitis may be modified in this population of patients. The reason for this modified clinical picture is probably the immune incompetence associated with uremia, which favors both the development of metastatic endophthalmitis as well as altering its clinical presentation. While funduscopic examination is suggested in all dialysis patients with eye complaints, this procedure becomes mandatory following episodes of sepsis.

A 21-year-old woman developed bilateral keratoconjunctivitis from contact lens wear, which progressed to diffuse corneal scarring and vascularization after the patient refused to discontinue wearing contact lenses. The visual disturbance became so severe that a penetrating keratoplasty had to be performed in one eye for visual rehabilitation. Examination of the penetrating keratoplasty specimen disclosed destruction of Bowman's membrane throughout the superior half of the cornea, which was replaced by a fibrous scar that was only midly chronically inflamed. Deep vascularization occurred within the stroma. This case represents an extreme expression of a recently characterized syndrome consisting of conjunctival and corneal changes in patients who may be allergic to contact lenses or the solutions used in conjunction with their care. In the milder end of the spectrum, there is superior epibulbar conjunctival injection with associated tarsal injection, and a mild superficial punctate keratopathy without filaments. Some earlier workers have termed this syndrome a variant of superior limbic keratoconjunctivitis in association with contact lens wear, but this leads to confusion with Theodore's classical superior limbic keratoconjunctivitis, to which the present entity bears no etiologic relationship; it also fails to show many of the findings of Theodore's disease. In mild cases, we would recommend the term contact lens-induced keratoconjunctivitis, and in the more severe cases, such as demonstrated by our patient, we would suggest the term contact lens-induced keratopathy.

Endothelial pigmentation does not usually interfere with vision. This case report documents a dense and extensive deposition of uveal pigment in corneal endothelial cells of a patient who had undergone 2 previous grafts subsequent to an alkali burn injury. The previous graft in which the pigmentation occurred remained compensated, but vision was impaired secondary to dense endothelial pigmentation. A combination of the initial chemical injury, recurrent iritis, chronic glaucoma, and multiple intraocular procedures may have resulted in the stimulus for the uveal tract to disperse a large amount of pigment onto the cornea and its subsequent phagocytosis by the endothelium. Endothelial pigmentation may become a more commonly seen complication in attempts to treat the severely damaged anterior segment.

This article reports a new concept in the treatment of tear film abnormalities. Solubilization of an artifical tear insert provides a continuous flow of polymer into the tear film in place of intermittent drop therapy. The physiochemical properties of succinylated collagen were studied in vitro and compared favorably with presently available tear substitutes. The use of this polymer as a solid solubilizable insert was evaluated in normal patients. It was found to be comfortable, resulted in no blurring of vision, and prolonged the tear film breakup time.

This case represents the successful removal of a transparent anterior chamber scroll and the subsequent resolution of corneal edema overlying the tissue. It emphasizes the clinical observation that a small area of endothelial touch can be associated with a disproportionately large area of overlying corneal edema, and may indeed be the cause of it.

This is the first case report of cataracts in patients with thalassemia major. Desferrioxamine, an iron-chelating agent is being used with increasing frequency in the treatment of transfusion-induced iron overload. There has been some concern in the literature about possible cataract formation with use of this drug. It is therefore important to document any lens opacities seen prior to administration of desferrioxamine, or record the appearance of lens opacities after its use. The possible eitology of these lens opacities is discussed.

A 40-year-old black man had two penetrating keratoplasties as a result of complications from alkali burns sustained many years earlier. Two further penetrating keratoplasties were performed for recurrent retrocorneal pigmentation. Both scanning and transmission electron microscopy demonstrated that the retrocorneal pigmented cells were iris melanocytes, based upon their fusiform or dendritic shapes and measurements of their cytoplasmic melanin granules. Repopulation of Descemet's membrane by the melanocytes was produced by a small remnant of atrophic iris. The pigment granules in the iris melanocytes were somewhat larger than those seen in similar cells from Caucasians or Orientals, but had identical measurements to those studied in an iridectomy specimen from another black patient. The retrocorneal iris melanocytes were able to synthesize banded basement membrane material, interrupted laminar basement membrane, and collagen fibrils. The cause of the exfoliation of the iris melanocytes onto the back of the cornea is unknown, but the discovery that iris melanocytes can proliferate in an ongoing fashion and secrete extracellular matrix provides new insight into the physiology of these cells.

A case of scleral tuberculosis was successfully treated by combined systemic and local therapy. The importance of biopsy for early diagnosis and initiation of curative treatment is stressed.