Diversity of DNA beta,a satellite molecule associated with some monopartite begomoviruses

DNA beta molecules are symptom-modulating, single-stranded DNA satellites associated with monopartite begomoviruses (family Geminiviridae). Such molecules have thus far been shown to be associated with Ageratum yellow vein virus from Singapore and Cotton leaf curl Multan virus from Pakistan. Here, 26 additional DNA beta molecules, associated with diverse plant species obtained from different geographical locations, were cloned and sequenced. These molecules were shown to be widespread in the Old World, where monopartite begomoviruses are known to occur. Analysis of the sequences revealed a highly conserved organization for DNA beta molecules consisting of a single conserved open reading frame, an adenine-rich region, and a region of high sequence conservation [the satellite conserved region (SCR)]. The SCR contains a potential hairpin structure with the loop sequence TAA/GTATTAC; similar to the origins of replication of geminiviruses and nanoviruses. Two major groups of DNA beta satellites were resolved by phylogenetic analyses. One group originated from hosts within the Malvaceae and the second from a more diverse group of plants within the Solanaceae and Compositae. Within the two clusters, DNA beta molecules showed relatedness based both on host and geographic origin. These findings strongly support coadaptation of DNA beta molecules with their respective helper begomoviruses.     

Effect of repetitive exercise testing on breathlessness in humans

There are conflicting reports on the reproducibility of the visual analogue scale (VAS) and the modified Borg scale for the estimation of breathlessness during exercise. In an attempt to clarify the situation, two groups of healthy subjects undertook a progressive exercise test either daily (Group A) or weekly (Group B) on 10 separate occasions. Breathlessness was estimated every 1 min using the VAS. After 10 occasions, both Group A (P <0.05) and Group B ( P <0.01) showed a significant increase in the mean intercept of the breathlessness/ventilation (VAS/ V (I)) relationship. The increase was not progressive; using change point regression, reproducible values were found to occur after approximately the fifth occasion in both subject groups. As the slope of the VAS/ V (I) relationship was highly reproducible and did not change with repeat testing, it would appear that at least two mechanisms are involved in the generation of the sensation of breathlessness. A decrease in the exercise heart rate over the same time period was significantly correlated with changes in the VAS/ V (I) intercept in both groups (P <0.01 and P <0.005 respectively). The relationship is unlikely to be causal, but may be indicative of a common underlying mechanism. It is suggested that breathlessness scores are likely to decrease as a direct result of repetitive testing over, on average, the first five periods of assessment. On the basis of this study, it may be inferred that a physiological mechanism contributes to the modulation of breathlessness during repetitive exercise testing.     

New lysophosphatidylcholines and monoglycerides from the marine sponge Stelletta sp

Two new lysophosphatidylcholines (1, 2) and four new monoglycerides (5-8) were isolated from the marine sponge Stelletta sp. by bioactivity-guided fractionation. The planar structures of the new compounds were established on the basis of NMR and MS analyses. The stereochemistry was defined by comparison of the optical rotation. The compounds were evaluated for cytotoxicity against a small panel of five human tumor cell lines.     

Ex situ preparation of left split-liver grafts with left vascular pedicle only: is it safe? A comparative single-center study

The procurement of left-lateral-segment grafts from living donors for transplantation in children is performed by retaining only the left branches of the artery and veins. New techniques and the implementation of microsurgery in the transplant operation made this procedure a successful approach. However, controversy persists about using such an approach for division of liver grafts from cadaveric donors, and many teams prefer retaining the main arterial trunk with the left split graft, with or without the main portal vein trunk. Since 1998, in our center, when a donor-liver graft is divided we prefer retaining the main vessels with the right split graft if graft vascular anatomy is favorable. After 1998, 40 liver grafts from cadaveric donors were divided, and all divisions were performed ex situ. This experience was retrospectively reviewed to compare the outcome of left split grafts prepared for implantation with the left vasculature only (group A), or with the main arterial supply (group B). A single vascular complication occurred (one hepatic artery thrombosis in group B). Three patients died (one in group A and two in group B) and three other grafts were lost (one in group A and two in group B). One-year and 3-year graft survival rates were 94% and 86% in group A, and 83% and 83% in group B, respectively (not significantly [NS] different). We conclude that left split grafts can be safely transplanted with the left vascular supply only, provided that division is guided by careful anatomical evaluation and that vascular reconstructions are adequate.     

Modern aspects of continuous medical education

Continuous medical education represents the final and often most poorly understood stage of physician education. It is defined as any and all ways by which doctors learn after the formal completion of their training. While evidence-based medicine is defined as "the conscientious, explicit and judicious use of current best evidence in making decisions for the care of individual patients. The practice of evidence-based medicine means integrating individual clinical expertise with the best available external clinical evidence from systematic research." The primary purpose of this article is to discuss the modern and technological aspects of continuing medical education and how it helps to maintain and improve clinical performance of practicing doctors and patient care. The article also emphasizes evidence-based medicine as a newly evolved, rapidly growing discipline for learners and researchers, which has extended the application of its principles to all professions associated with health care, including purchasing and management.     

Histopathological and immuno-histochemical characteristics of primary renal primitive neuroectodermal tumor

We report a 32-year-old male who presented with huge (17 x 10.5 x 5 cm) right kidney with metastasis in the liver and retroperitoneal lymph nodes. Histological, detailed immunohistochemical studies and electron microscopic examinations were performed. Microscopy revealed small to intermediate sized cells with hyperchromatic nuclei, scanty cytoplasm, abundant mitosis with no pseudorossete formation. Immunohistochemical study revealed positive staining of the tumor cells for S100, neurofilaments, neuron specific enolase, vimentin and myoglobin. Primitive neuroectodermal tumors are rare malignant round cell tumors of the kidney. A correct diagnosis can be made on light microscopic features, and by immunohistochemically positive staining for more than one neural marker. This neoplasm should be differentiated from other renal neoplasms composed of small round cells.