Completion rates of anterior and posterior continuous curvilinear capsulorrhexis in pediatric cataract surgery for surgery performed by trainee surgeons with the use of a low-cost viscoelastic

Context : Pediatric cataract surgery is traditionally done with the aid of high-molecular-weight viscoelastics which are expensive. It needs to be determined if low-cost substitutes are just as successful. Aims : The study aims to determine the success rates for anterior and posterior capsulorrhexis and intraocular lens (IOL) implantation in the bag for pediatric cataract surgery performed with the aid of a low-molecular-weight viscoelastic. Settings and Design : Nonrandomized observational study. Materials and Methods: Children less than 6 years of age who underwent cataract surgery with IOL implantation in the period May 2008-May 2009 were included. The surgeries were done by pediatric ophthalmology fellows. A standard procedure of anterior capsulorrhexis, lens aspiration with primary posterior capsulorrhexis, anterior vitrectomy, and IOL implantation was followed. Three parameters were studied: successful completion of anterior and posterior capsulorrhexis and IOL implantation in the bag. Results: 33 eyes of 28 children were studied. The success rate for completion was 66.7% and 88.2 % for anterior and posterior capsulorrhexis, respectively. IOL implantation in the bag was successful in 87.9%. Conclusions: 2% hydroxypropylmethylcellulose is a viable low-cost alternative to more expensive options similar to high-molecular-weight viscoelastics. This is of great relevance to hospitals in developing countries

Molecular dissection of an hCG-β epitope using single-step solid phase radioimmunoassa

Background: Peptides and proteins have both sequence-specific (contiguous) and conformation-specific (discontiguous) epitopes. Sequence-specific epitopes are delineated by peptide approach and other robust methods like competition assays, gene expression assays, synthetic peptide library based assays etc. Available methods for delineation of conformation-specific epitopes are cumbersome (X-ray crystallography etc.), time consuming and require costly sophisticated equipments. Hence, there is a need to develop a simple method for identification and mapping of conformation-specific epitopes. Method: In the single-step solid phase radioimmunoassay (SS-SPRIA), an immunochemical bridge of ‘mouse IgG-anti-mouse IgG’ was prepared in the polypropylene wells followed by adsorption with hCG specific monoclonal antibody (MAb) $G_1G_{10.}1$. The extent of competitive inhibition in binding ability of $^{125}IhCG-β$ with chemically or enzymatically modified hCG-β to immobilized MAb $G_1G_{10.}1$ in comparison to hCG-β standards was utilized to identify the epitopic amino acid involved in epitope–paratope interaction. Results: Data clearly suggest that the epitope under investigation consisted of Arg (94, 95) and Asp (99) at the core region with a Lys (104) and a His (106) in the proximity and absence of chymotrypsin susceptible Phe or Tyr in this region. Conclusion: The data of SS-SPRIA revealed the 93–100 loop of amino acid sequence, as the core region of conformation-specific epitope of hCG-β at or near the receptor-binding region. Hence, SS-SPRIA seems to be a simple method for identification and mapping of conformation-specific epitopes

Markovian Approach to Automatic Annotation of Breast Mass Spicules Using an A Contrario Model

International audienceIn this paper, we propose a new method for automatic extraction of breast mass spicules in 2-D mammography. Spicules are abnormal curvilinear structures which characterize most of malignant breast masses. They are important features for discrimination between benign and malignant masses. In our method, the curvilinear structures are first approximated by line segments derived from localized Radon transforms; then, the Markov random field is used to take into account the local interactions via the contextual information between these segments. Finally, detection of the curvilinear structures that most likely correspond to spicules is performed using an a contrario framework. Validation of the approach was performed on a large dataset of spiculated masses which were selected from a public digital database; the results showed a high agreement with manually annotated mammograms