Epithelial cells were isolated from rat and chick small intestine by techniques which separated subpopulations of differentiating villus and upper crypt cells from each other and from populations of mitotically dividing lower crypt cells. Incorporation of precursors into epithelial-cell DNA, cytoplasmic rRNA and cytoplasmic poly(A)-containing RNA occurred in the lower crypt cells in vivo when p...

We have previously shown that the epithelium of each adult intestinal crypt in chimaeric mice is derived from a single progenitor cell. Whether the crypts are monoclonal from the outset-that is, are formed by the proliferation of a single cell-or whether their formation is initiated by several cells was not known. Here we report that many crypts contain cells of both chimaeric genotypes in the ...

Immune reconstitution inflammatory syndrome (IRIS) presents as an exaggerated immune reaction that occurs during dysregulated restoration in immunocompromised patients late-stage human immunodeficiency virus (HIV) infection who have commenced antiretroviral treatments (ART). Virtually any opportunistic pathogen can provoke this type of disorder. In review, we focus on recent developments the id...

surface of the gastrointestinal tract is lined by a simple columnar epithelium that is folded to form a number of invaginations, or crypts, that are embedded in the connective tissue. Each crypt contains approximately 250 cells, depending on its species and anatomical location. Crypt size and organization are generally uniform within a given region of the gastrointestinal tract (1). Of the majo...

Iris varix is rare and little is known about its clinical characteristics. We treated a thrombosed iris varix that simulated an iris melanoma. A 53-year-old man developed a dark brown iris mass and hyphema in his left eye. Ultrasound biomicroscopy revealed a circumscribed mass of the iris stroma. Because of suspicion for melanoma, it was removed by sector iridectomy. Histopathologic examination...

The authentication of people using Iris based recognition system is the most reliable biometric traits due to its stability, invariant and distinctive features for personal identification. Iris recognition consists of localization of the Iris region, extracting Iris features, generation of data set of Iris images and then Iris pattern recognition. This paper presents Iris recognition system bas...

We present a novel iris repair technique for the management of iris transillumination defects secondary to iris pigment epithelium (IPE) loss, which includes iris oversewing over the defect through partial iris stromal bites with 10-0 polypropylene. This technique provides a healthy layer of iris covering the transillumination defect without the creation of new defects on the contiguous IPE.

High performance human identification using iris biometrics requires the development of automated algorithms for robust segmentation of the iris region given an ocular image. Many studies have shown that iris segmentation is one of the most crucial element of iris recognition systems. While many iris segmentation techniques have been proposed, most of these methods try to leverage gradient info...

The majority of the iris recognition algorithms available in the literature were developed to operate on near infrared images. A desirable feature of iris recognition systems with reduced constraints such as potential operability on commonly available hardware is to work with images acquired under visible wavelength. Unlike in near infrared images, in colour iris images the pigment melanin pres...