Bilateral versus unilateral cataract extraction: advantages and complications.

Cataract extraction was performed on 734 patients. These were followed up postoperatively for up to 1 year. In 448 cases the extraction was performed in both eyes during 1 operating session (896 eyes) and in 1 eye in 286 cases, a total of 1182 cataract extractions. Preoperatively more than 75% of the eyes in both groups had perception of light only. Postoperatively more than 85% of eyes in both groups achieved a visual acuity of 6/30 or better. The postoperative visual performance of an eye was not influenced by the mode of operation, bilateral or unilateral. The overall incidence of complications among the 1182 operated eyes was: accidental extra-capsular cataract extraction 10.2%, vitreous loss 11.0%, hyphaema 1.4%, flat anterior chamber 0.9%, dehiscence of the wound 0.5%, uveitis 1.2%, endophthalmitis 0.3%, secondary glaucoma 0.9%, severe bullous keratopathy 1.4%, oedema of the macula 0.5%, and retinal detachment 0.3%. The complications in both groups of patients were comparable. Only in 1 case operated in both eyes vision was not restored following a bilateral endophthalmitis.     

Allergic contact dermatitis caused by naturally occurring quinones

Quinones play a major role in allergic contact dermatitis caused by plants. The principal allergens are benzoquinones or naphthoquinones but also compounds, such as catechols and other phenolic or flavonoid compounds, which are bioconverted intoortho-quinones orpara-quinones. The high electrophilic reactivity of these compounds toward nucleophilic residues of proteins associated with lipophilic properties may explain that they are strong sensitizers. The more important allergens are reported and their structure-activity relationship is discussed.     

Incidence and causes of blindness among the under 5 age group in Malawi.

The expected incidence of blindness among children under 5 years of age in Malawi is 34 cases per 100 000 children. Direct ocular infections were responsible for the blindness in 32% of the cases (bacterial infections 20% and measles 12%). The instillation of traditional medicine in these cases worsened the ocular condition and induced in all of the cases a "hopeless" situation of total melting of the cornea and protrusion of the uvea. Congenital factors (excluding retinoblastomas) were responsible for 30-8% of the blind cases. Among these, 11 cases of congenital cataracts were successfully treated and will not appear as blind in future. A high incidence (9-3%) of cortical blindness was recorded. Trauma was implicated in 5-3%, while retinoblastoma was found in 8%. It is believed that adequate preventive measures should be able to lower the incidence of blindness among this age group to 5 cases instead of 34 per 100 000 children.     

Double-headed haptens with pyrocatechol (poison ivy like) and methylene lactone functional groups: a search for skin-tolerance inducers

In order to develop new theories for desensitization, a potential skin sensitizer, 1, with two different haptenic ends, a pyrocatechol group and an alpha-methylene-gamma-butyrolactone moiety, separated by a straight nine-carbon-atom chain has been prepared and used to sensitize guinea pigs. A "monohapten" 8 containing an electrophylic alpha-methylene-gamma-butyrolactone, connected to a dimethoxybenzene group, has also been prepared. Both the "bihapten" 1 and the "monohapten" 8 were shown to be sensitizers. Bihapten 1 sensitized animals recognized only bihapten 1 (and not the lactone 8) while monohapten 8 sensitized guinea pigs reacted to both 8 and 1. Bihapten 1 treated animals were further sensitized to monohapten 8 and challenged to the latter: the skin intensity reaction was significantly lower than the test to 8 in 8-sensitized animals. Bihapten 1 seems therefore to "tolerize" against the alpha-methylene-gamma-butyrolactone end.     

BRAFV600E mutation is associated with preferential sensitivity to mitogen-activated protein kinase kinase inhibition in thyroid cancer cell lines

CONTEXT: Mutually exclusive mutations of RET, RAS, or BRAF are present in about 70% of papillary thyroid carcinomas, whereas only the latter two are seen in poorly differentiated and anaplastic cancers. Although the signal output common to these oncoproteins is ERK, a recent report showed that only BRAF mutations consistently predicted responsiveness to MAPK kinase (MEK) inhibitors. OBJECTIVES: Here we investigated whether sensitivity to MEK inhibition was determined by oncogene status in 13 human thyroid cancer cell lines: four with BRAF mutations, four RAS, one RET/PTC1, and four wild type. RESULTS: Growth of BRAF (+) cells was inhibited by the MEK antagonist PD0325901 with an IC(50) of less than 5 nm. By contrast, RAS, RET/PTC1, or wild-type cells had IC(50) of 4 nm to greater than 1000 nm. Sensitivity was not predicted by coexisting mutations in PIK3CA or by PTEN status. Similar effects were obtained with the MEK inhibitor AZD6244. PD0325901 induced a sustained G1/S arrest in BRAF (+) but not BRAF (-) lines. PD0325901 was equipotent at inhibiting pERK1/2 after 2 h, regardless of genetic background, but pERK rebounded at 24 h in most lines. MEK inhibitor resistance was associated with partial refractoriness of pERK to further inhibition by the compounds. AZD6244 was more potent at inhibiting growth of NPA (BRAF +) than Cal62 (KRAS +) xenografts. CONCLUSION: Thyroid cancers with BRAF mutation are preferentially sensitive to MEK inhibitors, whereas tumors with other MEK-ERK effector pathway gene mutations have variable responses, either because they are only partially dependent on ERK and/or because feedback responses elicit partial refractoriness to MEK inhibition.     

Thrombin as a multifunctional protein: induction of cell adhesion and proliferation.

The serine protease thrombin (E.C.3.4.21.5) is well recognized for its central role in hemostasis. In addition, thrombin is unique among the enzymes participating in the clotting cascade, by virtue of its cell activation effects induced via the enzymatic pocket or via functional domains located throughout the molecule. In this review, we elaborate on "nonhemostatic" activities of thrombin among which are interactions with vessel wall components. These activities include promotion of cellular adhesion and induction of smooth muscle cell proliferation. Thrombin can exert these effects when it is in a fluid phase and when it is immobilized to extracellular matrix.     

IOL implantation following cataract extraction in children with uveitis Surgery and immediate follow-up

The surgical technique and immediate results following posterior chamber IOL implantation after cataract extraction in eight children suffering from chronic uveitis are described. In all cases, improvement of the visual acuity and a better control of the intraocular inflammatory processes could be achieved after surgery. In three of the eight eyes a multifocal IOL was implanted, while five eyes received a monofocal lens. Long-term follow-up of these cases will enable us to evaluate the feasibility of IOL implantation as a routine procedure in children suffering from chronic uveitis and complicated cataract in one eye.     

Treatment of vernal keratoconjunctivitis a double-masked study

Thirty-one children aged five to 14 years with severe vernal keratoconjunctivitis (VKC) were enrolled in a double-masked study evaluating the efficacy of three ophthalmic preparations: cromolyn sodium (Opticrom) 2%, artificial tears and fluorometholone 0.1% (FML). These drugs were coded respectively as A, B, C, and dispensed in similar bottles. Both eyes were treated, and drug assignment was made at random. Objective assessment of the disease activity was done under slit lamp by two ophthalmologists according to a five-point scale. The results were tabulated and the chi-square test performed. Decoding of the drugs was done only after completion of the statistical analysis. FML was found effective with a statistically significant difference from the other two drugs, both after the first week on the initially assigned treatment (p = 0.05) and on completion of the treatment period according to protocol (p = 0.005). Although several patients improved under cromolyn sodium, there was no statistically significant difference between cromolyn sodium 2% and artificial tears. All the preparations were well tolerated. One patient developed bilateral allergic blepharitis when treated with FML during the study. Another patient who responded well to FML developed posterior subcapsular cataract while continuing treatment with corticosteroids a few months after completion of the study.