Development of a standard set of microsatellite reference alleles for identification of grape cultivars.

In order to investigate the comparability of microsatellite profiles obtained in different laboratories, ten partners in seven countries analyzed 46 grape cultivars at six loci (VVMD5, VVMD7, VVMD27, VVS2, VrZAG62, and VrZAG79). No effort was made to standardize equipment or protocols. Although some partners obtained very similar results, in other cases different absolute allele sizes and, sometimes, different relative allele sizes were obtained. A strategy for data comparison by means of reference to the alleles detected in well-known cultivars was proposed. For each marker, each allele was designated by a code based on the name of the reference cultivar carrying that allele. Thirty-three cultivars, representing from 13 to 23 alleles per marker, were chosen as references. After the raw data obtained by the different partners were coded, more than 97% of the data were in agreement. Minor discrepancies were attributed to errors, suboptimal amplification and visualization, and misscoring of heterozygous versus homozygous allele pairs. We have shown that coded microsatellite data produced in different laboratories with different protocols and conditions can be compared, and that it is suitable for the identification and SSR allele characterization of cultivars. It is proposed that the six markers employed here, already widely used, be adopted as a minimal standard marker set for future grapevine cultivar analyses, and that additional cultivars be characterized by means of the coded reference alleles presented here. The complete database is available at http://www.genres.de/eccdb/vitis/ Cuttings of the 33 reference cultivars are available on request from the Institut National de la Recherche Agronomique Vassal collection (didier.vares@ensam.inra.fr).

Refractive Error Study in Children: sampling and measurement methods for a multi-country survey.

PURPOSE: The Refractive Error Study in Children was designed to assess the prevalence of refractive error and vision impairment in children of different ethnic origins and cultural settings. METHODS: Population-based cross-sectional samples of children 5 to 15 years of age were obtained through cluster sampling. Presenting, uncorrected, and best-corrected visual acuity, along with refractive error under cycloplegia, were the main outcome measures. Amblyopia and other causes of uncorrectable vision impairment were determined. RESULTS: Study design and sample size calculations, survey enumeration and ophthalmic examination methods, quality assurance monitoring, and da ta analyses and statistical methods are described. CONCLUSIONS: The study design, sample size, and measurement methods ensure that the prevalence of age-specific and sex-specific refractive error can be estimated with reasonable accuracy in the target populations. With commonality of methods, a comparison of findings between studies in different ethnic origins and cultural settings is possible.

Refractive Error Study in Children: results from La Florida, Chile.

PURPOSE: To assess the prevalence of refractive errors and vision impairment in school-age children in a suburban area (La Florida) of Santiago, Chile. METHODS: Random selection of geographically defined clusters was used to identify a representative sample of children 5 to 15 years of age. Children in the 26 selected clusters were enumerated through a door-to-door survey and invited to report to a community health clinic for examination. Visual acuity measurements, cycloplegic retinoscopy, cycloplegic autorefraction, ocular motility evaluation, and examination of the external eye, anterior segment, media, and fundus were done from April through August 1998. Independent replicate examinations of all children with reduced vision and a sample of those with normal vision were done for quality assurance monitoring in six clusters. RESULTS: A total of 6,998 children from 3,830 households were enumerated, and 5,303 children (75.8%) were examined. The prevalence of uncorrected, presenting, and best visual acuity 0.50 (20/40) or worse in at least one eye was 15.8%, 14.7%, and 7.4%, respectively; 3.3% had best visual acuity 0.50 or worse in both eyes. Refractive error was the cause in 56.3% of the 1,285 eyes with reduced vision, amblyopia in 6.5%, other causes in 4.3%, with unexplained causes in the remaining 32.9%. Myopia -0.50 diopter or less in either eye was present in 3.4% of 5-year-old children, increasing to 19.4% in males and 14.7% in females by age 15. Over this same age range, hyperopia 2.00 diopters or greater decreased from 22.7% to 7.1% in males and from 26.3% to 8.9% in females. Females had a significantly higher risk of hyperopia than males. CONCLUSIONS: Refractive error, associated primarily with myopia, is a major cause of reduced vision in school-age children in La Florida. More than 7% of children could benefit from the provision of proper spectacles. Efforts are needed to make existing programs that provide free spectacles for school children more effective. Further studies are needed to determine whether the upward trend in myopia continues far beyond 15 years of age.

[Cataract extraction with intraocular lenses in a teaching hospital]. / Extracción de catarata con implante de lente intraocular en un servicio docente.

One hundred and twelve primary posterior chamber intraocular lens implants from a series of 560 eyes operated on at the Eye Service of Hospital Salvador in Santiago, Chile, were analyzed to determine the postoperative visual acuity. The follow up time varied between 3 and 26 months. Lenses were implanted by experienced ophthalmologists and residents in training. Visual acuity was 0.5 or better in 79.5% of cases. The postoperative visual acuity varied with age, being worse in patients over 70 years old.

Análisis ultraestructural de las poblaciones celulares del trabéculo en la aniridia / Ultrastructural analysis of the celular population of the trabeculo in aniridia

El glaucoma que complica a la aniridia se debe generalmente a cambios post natales que se agregan a alteraciones determinadas congénitamente. Menos frecuente es el glaucoma congénito asociado a la aniridia. El principal cambio post natal es el cierre angular progresivo que finalmente termina adosando el muñón iridiano a la pared interna del trabéculo, alterando su función y determinando glaucoma. La patogenia que determina esta modificación morfológica y cierre angular es desconocida. El presente trabajo describe la proliferación de melanocitos en la superficie interna del trabéculo, espacios trabeculares, tejido yuxtacanalicular, pared externa del conducto de Schlemm y conductos colectores esclerales. Esta proliferación no ha sido descrita previamente en la aniridia y podría explicar las modificaciones angulares que llevan al glaucoma por cierre angular secundario en estos casos. Es probable que este mecanismo patogénico sea responsable de la refractariedad a los distintos tipos de tratamiento descritos en el glaucoma asociado a aniridia desde que el aspecto de las trabéculas, el conducto de Schiem y conductos colectores son aparentemente normales

A case of acute poisoning by methyl demeton in a female 5 months pregnant.

During the last decade the number of poisonings by pesticides in Portugal has been steadily rising. Out of 140 patients treated in our Intensive Care Unit (I.C.U.), 86 were male and 54 were female, one of whom was 5 months pregnant. Besides all the care and surveillance required by every case of acute poisoning, pregnant females raise particular problems. Four months later, she gave birth to a normal child. Its follow-up has shown a normal morpho-physiological and psycho-motor development.

The outflow pathway in congenital glaucoma.

We obtained specimens from the angle of the eye during a trabeculotomy-trabeculectomy operation of a 5-month-old boy with congenital glaucoma. Light and electron miscroscopy of the anterior chamber angle showed the presence of mesodermal tissue covering the entire trabecular area. The trabecular meshwork showed thickening of trabecular beams, and an increased amount of collagen fibrils in the trabecular matrix. Internal trabecular spaces contained red blood cells; outer trabecular spaces were not apparent. The juxtacanalicular trabecular meshwork was thicker than in normal cases, because of an increased amount of collagen fibrils. The endothelium of Schlemm's canal was underlined by a thick and constant layer of amorphous material. These observations suggested that the site of increased resistance to aqueous humor outflow in congenital glaucoma could be found in abnormalities of the trabecular meshwork and the internal wall of Schlemm's canal.

ATP is released into the rabbit eye by antidromic stimulation of the trigeminal nerve.

Antidromic stimulation of the trigeminal nerve produces an irritative response in the rabbit eye characterized by ipsilateral miosis, hyperemia, elevated intraocular pressure, and a disruption of the blood-aqueous barrier. The latter is a bilateral effect. The mediator or mediators involved in this response of the eye are unknown. Increased ATP levels in aqueous humor could be found after trigeminal stimulation. Treatment of rabbits with dipyridamole further increased ATP levels in aqueous humor after stimulation, confirming the findings of Holton that stimulation of sensory nerves causes a release of ATP. Intravitreal injections of ATP could not reproduce the ocular irritative response; however, an iridial hyperemia of long latency and an increase in aqueous humor protein levels were produced. The mechanism of this part of the reaction requires further study.

The management of lens damage in perforating corneal lacerations.

Lens damage is present in 30% of perforating injuries of the anterior segment of the eye. There is no consensus on whether the cataractous lens should be removed at the initial repair of the corneal laceration or later, when the eye has recovered from injury. Twenty-seven consecutive cases with a perforating corneal injury and lens damage were alternatively treated either with simultaneous corneal suturing and cataract removal or with corneal suturing and delayed cataract removal several weeks later. The difference in the frequency of complications between the 2 groups was significant. The 1-step procedure was technically easier to perform, the period of postoperative irritation was shorter, complications due to the presence of an injured lens were prevented, and visual rehabilitation occurred earlier.

Anterior segment surgery early after corneal wound repair.

Penetrating wounds of the cornea require immediate repair, generally within 24 hours. Tight closure of the wound and a reformed anterior chamber are the primary goals of surgery. However, there is no guarantee that further surgery will not be required for maintaining the healthy function of the anterior segment. At the second operation the effect of the procedure on the previously repaired wound is of prime importance, since in many cases the operation needs to be done before corneal healing is completed. In our series the lens, which was either partially or completely cataractous at the initial operation, became intumescent at different times afterwards, and an immediate removal was necessary. No change in the preoperative wound sealing or transparency of the cornea could be detected after lens surgery performed between 24 hours and 21 days from the initial corneal repair.

Retinitis pigmentosa associated with nevus flammeus and unilateral glaucoma.

A 53-year-old white man was noted to have bilateral retinitis pigmentosa associated with a left nevus flammeus, a left choroidal hemangioma and unilateral glaucoma. No central nervous system manifestations of Sturge-Weber syndrome were noted. The association of retinitis pigmentosa and the nevus flammeus is probably a chance occurrence.

Unilateral gonadectomy does not alter contralateral intraocular pressure in rabbit eyes.

The purpose of this study was to determine whether unilateral gonadectomy caused any change in intraocular pressure. Repeated measurements in 22 male and nine female rabbits after unilateral gonadectomy were made by three different methods of determining intraocular pressure. We were unable to find a decrease in intraocular pressure on the side opposite to the side of the removed gonad, as had been previously reported. Neither were any ipsilateral changes observed. A calibration curve (rabbit) for the applanation pneumatonograph is also presented.

The contralateral effect of antidromic stimulation of the trigeminal nerve on the rabbit eye.

The effect on contralateral eyes after injuries to one eye has been called the consensual reaction and has been postulated to be either the consequence of a neural reflex or one achieved by circulating substances. Trigeminal stimulation always causes ipsilateral miosis, ocular hyperemia, intraocular hypertension, and a disruption of the blood-aqueous barrier. Disruption of the blood-aqueous barrier in the contralateral eye after stimulation of the trigeminal nerve always occurs and depends on intact sensory innervation to that globe in rabbits. The disruption is not prevneted by pretreatment of the animals with indomethacin. The phenomenon of disruption of the barrier is sometimes accompanied by an elevation of intraocular pressure in the contralateral eye but not by the other irritative responses. Thus, unilateral stimulation of a sensory nerve, the trigeminal, in the rabbit, can produce ipsilateral contralateral disruption of the blood-aqueous barrier.

Objective evaluation of experimental ocular irritation.

After topically administered nitrogen mustard the irritative effect on the pupil, intraocular pressure, protein concentration of the aqueous humor and on the vessels of the iris and conjunctiva was quantified. The protein level in aqueous was determined by refractometry. The degree of hyperemia of conjunctiva and iris was determined by measuring the amount of Evans blue dye present in the tissue minutes after intravenous administration. A reproducible relationship was obtained using these methods to evaluate the degree of irritation produced by nitrogen mustard.