Molecular bases of cyclodextrin adapter interactions with engineered protein nanopores.

Engineered protein pores have several potential applications in biotechnology: as sensor elements in stochastic detection and ultrarapid DNA sequencing, as nanoreactors to observe single-molecule chemistry, and in the construction of nano- and micro-devices. One important class of pores contains molecular adapters, which provide internal binding sites for small molecules. Mutants of the alpha-hemolysin (alphaHL) pore that bind the adapter beta-cyclodextrin (betaCD) approximately 10(4) times more tightly than the wild type have been obtained. We now use single-channel electrical recording, protein engineering including unnatural amino acid mutagenesis, and high-resolution x-ray crystallography to provide definitive structural information on these engineered protein nanopores in unparalleled detail.

Pentapeptide based organogels: the role of adjacently located phenylalanine residues in gel formation.

A terminally protected self-assembling pentapeptide Boc-Leu(1)-Val(2)-Phe(3)-Phe(4)-Ala(5)-OMe 1 bearing sequence similarity with Aß17-21 (the fragment 17-21 of the amyloid ß-peptide Aß42) forms thermoreversible transparent gels in various organic solvents including benzene, toluene, m-xylene and 1,2-dichlorobenzene. A series of its variants have been synthesized in order to study the role of adjacently located phenylalanine residues and the protecting groups for gelation in different organic solvents. Replacement of any of the Phe residues of the Phe-Phe segment with any other hydrophobic α-amino acid residue drastically changes the gel forming properties indicating that both Phe residues have an important role in gel formation. These gels are characterised using field emission scaning electron microscopy (FE-SEM), transmission electron microscopy (TEM), FT-IR and wide angle X-ray scattering (WAXS) studies. WAXS studies of the peptide 1-benzene gel indicate that π-π interaction is responsible for gel formation and it reveals the necessity of the Phe residues in gel formation. Transmission electron microscopy (TEM) of the gels reveals a nanofibrillar morphology, which is obtained from the self-assembled gelators in the gel phase. These gels bind with a physiological dye, Congo red, and show a green birefringence under cross polarizers, which is a characteristic feature of amyloid fibrils.

Ringo: Interactive Graph Analytics on Big-Memory Machines.

We present Ringo, a system for analysis of large graphs. Graphs provide a way to represent and analyze systems of interacting objects (people, proteins, webpages) with edges between the objects denoting interactions (friendships, physical interactions, links). Mining graphs provides valuable insights about individual objects as well as the relationships among them. In building Ringo, we take advantage of the fact that machines with large memory and many cores are widely available and also relatively affordable. This allows us to build an easy-to-use interactive high-performance graph analytics system. Graphs also need to be built from input data, which often resides in the form of relational tables. Thus, Ringo provides rich functionality for manipulating raw input data tables into various kinds of graphs. Furthermore, Ringo also provides over 200 graph analytics functions that can then be applied to constructed graphs. We show that a single big-memory machine provides a very attractive platform for performing analytics on all but the largest graphs as it offers excellent performance and ease of use as compared to alternative approaches. With Ringo, we also demonstrate how to integrate graph analytics with an iterative process of trial-and-error data exploration and rapid experimentation, common in data mining workloads.

First crystallographic signature of an acyclic peptide nanorod: molecular mechanism of nanorod formation by a self-assembled tetrapeptide.

A terminally protected acyclic tetrapeptide Boc-Aib-Val-Aib-beta-Ala-OMe 1 (Aib: alpha-aminoisobutyric acid, beta-Ala: beta-Alanine) self-assembles into a continuous hydrogen-bonded supramolecular helix with an average diameter of 10 A (1 nm) starting from a double bend molecular conformation in crystals and further self-assembly of this supramolecular architecture leads to the formation of polydisperse nanorods of diameters 10-40 nm.

Childhood malignancies at BS Medical College: a ten year study.

A retrospective study of malignant diseases of childhood was carried out at B. S. Medical College, Bankura, W.B. to know the prevalence. It includes cases detected in this institution during 1990-1999 in the age group of 0-14 years. Cases were identified from previous records. Histopathology slides, stained by hematoxylin and eosin, were recovered and reviewed. Diagnosis were made by morphology. Hematological diagnosis were made by morphology and cyto-chemistry. In total 120 cases were detected. Acute leukemia (39.2%) was the commonest, followed by retinoblastoma (19.2%), lymphoma (10.8%), Wilm's tumor (10%) and rhabdomyosarcoma (9.1%). Brain tumors were not found due to non-availability of Neurosurgical Unit in this institution. Frequency of neuroblastoma was very low, only 2 out of a total of 120. In comparison to studies in Southern India and Western countries retinoblastoma and soft tissue sarcoma are more prevalent here, while there is a much lower prevalence of neuroblastoma.

Histopathological study of conjunctival lesions.

Lesions of conjunctiva comprise a varied spectrum of conditions. A total of 50 patients, 34 males and 16 females, with lesions in conjunctiva were subjected to study. Histopathological examination of the biopsied specimens from the lesions was done using haematoxylin and eosin (H&E) stain and other special stains when needed. The study was done to report the spectrum and frequency of different lesions of conjunctiva in a tertiary care eye hospital in India.

Bilateral scleromalacia in a case of congenital erythropoietic porphyria.

A 25-year-old woman presented with gradual dimness of vision in the left eye with history of recurrent cutaneous bullae, photosensitivity and passage of red coloured urine. Examination revealed cataract and high intra-ocular pressure in left eye and symmetrical areas of scleral thinning in both eyes. Systemic features of the patient pointed towards congenital erythropoietic porphyria, which was established by laboratory investigations.