Proteins connecting the nuclear pore complex with the nuclear interior

While much has been learned in recent years about the movement of soluble transport factors across the nuclear pore complex (NPC), comparatively little is known about intranuclear trafficking. We isolated the previously identified Saccharomyces protein Mlp1p (myosin-like protein) by an assay designed to find nuclear envelope (NE) associated proteins that are not nucleoporins. We localized both Mlp1p and a closely related protein that we termed Mlp2p to filamentous structures stretching from the nucleoplasmic face of the NE into the nucleoplasm, similar to the homologous vertebrate and Drosophila Tpr proteins. Mlp1p can be imported into the nucleus by virtue of a nuclear localization sequence (NLS) within its COOH-terminal domain. Overexpression experiments indicate that Mlp1p can form large structures within the nucleus which exclude chromatin but appear highly permeable to proteins. Remarkably, cells harboring a double deletion of MLP1 and MLP2 were viable, although they showed a slower net rate of active nuclear import and faster passive efflux of a reporter protein. Our data indicate that the Tpr homologues are not merely NPC-associated proteins but that they can be part of NPC-independent, peripheral intranuclear structures. In addition, we suggest that the Tpr filaments could provide chromatin-free conduits or tracks to guide the efficient translocation of macromolecules between the nucleoplasm and the NPC.     

In vitro micropropagation of Lawsonia inermis (Lythraceae)

A successful protocol was developed for mass propagation of Lawsonia inermis Linn., an important medicinal plant. Multiple shoots were induced in apical and axillary meristems derived from mature explants of L. inermis on Murashige and Skoog (1962) medium supplemented with 0.25 mg/l 6-benzylaminopurine (BA), 0.25 mg/l Kinetin (Kn), 0.5 mg/l ascorbic acid and 3% (w/v) sucrose. The rate of multiplication was higher when the cultures were incubated under continuous light rather than the 14 hr photoperiod. Rooting was readily achieved upon transferring the microshoots onto MS basal semi-solid medium supplemented with 0.25 mg/l indole-3-butyric acid (IBA) after ten days of culture. Micropropagated plantlets were acclimatized and successfully grown in soil.     

Cleave to leave: structural insights into the dynamic organization of the nuclear pore complex

A detailed understanding of the fine structure of the nuclear pore complex has remained elusive. Now, studies on a small protein domain have shed light on the dynamic organization of this massive assembly.     

Simulated brain tumor growth dynamics using a three-dimensional cellular automaton

We have developed a novel and versatile three-dimensional cellular automaton model of brain tumor growth. We show that macroscopic tumor behavior can be realistically modeled using microscopic parameters. Using only four parameters, this model simulates Gompertzian growth for a tumor growing over nearly three orders of magnitude in radius. It also predicts the composition and dynamics of the tumor at selected time points in agreement with medical literature. We also demonstrate the flexibility of the model by showing the emergence, and eventual dominance, of a second tumor clone with a different genotype. The model incorporates several important and novel features, both in the rules governing the model and in the underlying structure of the model. Among these are a new definition of how to model proliferative and non-proliferative cells, an isotropic lattice, and an adaptive grid lattice.     

A Case of Post Kala-Azar Dermal Leishmaniasis in India

Post kala-azar dermal leishmaniasis (PKDL) is a rare disease. This is a solitary case report from Orissa, India. We describe a case of PKDL in a 55-year-old male who presented with multiple nodular lesions over face, trunk, and extremities. The patient had been to an endemic area of kala-azar and had a previous history of leishmaniasis. Fine needle aspiration cytology samples from skin nodules revealed Leishmania amastigotes.