Biomedical subjects

David Mittelman

Publications and source records attributed to David Mittelman.

4 recordsLinked to original sources

PubMed2003

Probabilistic scoring measures for profile-profile comparison yield more accurate short seed alignments.

MOTIVATION: The development of powerful automatic methods for the comparison of protein sequences has become increasingly important. Profile-to-profile comparisons allow for the use of broader information about protein families, resulting in more sensitive and accurate comparisons of distantly related sequences. A key part in the comparison of two profiles is the method for the calculation of scores for the position matches. A number of methods based on various theoretical considerations have been proposed. We implemented several previously reported scoring functions as well as our own functions, and compared them on the basis of their ability to produce accurate short ungapped alignments of a given length. RESULTS: Our results suggest that the family of the probabilistic methods (log-odds based methods and prof_sim) may be the more appropriate choice for the generation of initial 'seeds' as the first step to produce local profile-profile alignments. The most effective scoring systems were the closely related modifications of functions previously implemented in the COMPASS and Picasso methods.

Algorithms↗

PubMed2003

Amblyopia.

Amblyopia is a serious medical condition affecting tens of millions of individuals around the world. For the most part it is correctable, assuming that it is promptly recognized and vigorously treated. Amblyopia may result from form deprivation, anisometropia, or strabismus in infants and young children. Basic research in animal models has shown that the major pathologic changes in amblyopia occur in the visual cortex of the brain. The mainstay of treatment remains patching, although penalization has a role to play in the management of moderate degrees of amblyopia. Better methods for early identification of patients with amblyopia are being developed, along with newer novel methods of treatment.

Amblyopia↗

PubMed2002

Parallel assessment of CpG methylation by two-color hybridization with oligonucleotide arrays.

We have developed a method for the parallel analysis of multiple CpG sites in genomic DNA for their state of methylation. Hypermethylation of CpG islands within the promoters and 5' exons of genes has been found to be a mechanism of transcriptional inactivation associated with a variety of tumors. The method that we developed relies on the differential reactivity of methylated and unmethylated cytosines with sodium bisulfite, which exclusively converts unmethylated cytosines to deoxyuracils. The resulting sequence changes are determined with single-nucleotide resolution by hybridization to an oligonucleotide array. Cohybridization with a reference sample containing a different label provides an internal standard for assessment of methylation state. This method provides advantages in parallelism over existing methods of methylation analysis. We have demonstrated this technique with a region from the promoter of the tumor suppressor gene p16, which is hypermethylated in many cancers.

Base Sequence↗

PubMed2002

ARROGANT: an application to manipulate large gene collections.

ARROGANT (ARRay OrGANizing Tool) is a software tool developed to facilitate the identification, annotation and comparison of large collections of genes or clones. The objective is to enable users to compile gene/clone collections from different databases, allowing them to design experiments and analyze the collections as well as associated experimental data efficiently. ARROGANT can relate different sequence identifiers to their common reference sequence using the UniGene database, allowing for the comparison of data from two different microarray experiments. ARROGANT has been successfully used to analyze microarray expression data for colon cancer, to compile genes potentially related to cardiac diseases for subsequent resequencing (to identify single nucleotide polymorphisms, SNPs), to design a new comprehensive human cDNA microarray for cancer, to combine and compare expression data generated by different microarrays and to provide annotation for genes on custom and Affymetrix chips.

Base Sequence↗