Differential regulation of the attachment of KSHV infected human B cells to ECM by KSHV encoded gB and cellular alpha-V integrins

Kaposi’s sarcoma-associated herpesvirus (KSHV) has two modes replication: latent and lytic replication. Reactivation from latency is dictated, in part, by the cell cycle. Herein, we have attempted to delineate the importance of cell cycle in KSHV pathogenesis by exploring the expression pattern of cell surface receptors during different phases of the cell cycle. αV integrin expression is augmented during S phase in fibroblasts, epithelial, and KSHV infected cells. Using a Matrigel system, we pioneer the concept that KSHV infected primary effusion lymphoma (PEL) cells can attach to extracellular matrix proteins. This attachment is mediated primarily via αV integrins or virally encoded gB, and occurs preferentially in cells from S phase or cells from S phase actively supporting a lytic infection, respectively. Such an ability of infected B cells to attach to endothelial cells may also aid in the dissemination of infection. The keystone of this work is that for the first time, we describe the ability of KSHV infected B cells to preferentially use cellular (αV) or viral (gB) receptors to specifically bind cells, depending upon the stage of the cell cycle and infection. Originally published Cellular Microbiology, Vol. 10, No. 7, July 200

X-boson cumulant approach to the periodic Anderson model

The Periodic Anderson Model (PAM) can be studied in the infinite U limit by employing the Hubbard X operators to project out the unwanted states. We have already studied this problem employing the cumulant expansion with the hybridization as perturbation, but the probability conservation of the local states (completeness) is not usually satisfied when partial expansions like the Chain Approximation (CHA) are employed. Here we treat the problem by a technique inspired in the mean field approximation of Coleman's slave-bosons method, and we obtain a description that avoids the unwanted phase transition that appears in the mean-field slave-boson method both when the chemical potential is greater than the localized level Ef at low temperatures (T) and for all parameters at intermediate T.Comment: Submited to Physical Review B 14 pages, 17 eps figures inserted in the tex

Contemporary percutaneous treatment of unprotected left main coronary stenoses: initial results from a multicenter registry analysis 1994-1996.

BACKGROUND: Coronary artery bypass surgery (CABG) has been considered the therapy of choice for patients with unprotected left main (ULMT) coronary stenoses. Selected single-center reports suggest that the results of percutaneous intervention may now approach those of CABG. METHODS AND RESULTS: To assess the results of percutaneous ULMT treatment from a wide variety of experienced interventional centers, we requested data on consecutive patients treated after January 1, 1994, from 25 centers. One hundred seven patients were identified who were treated either electively (n=91) or for acute myocardial infarction (n=16). Of patients treated electively, 25% were considered inoperable, and 27% were considered high risk for bypass surgery. Primary treatment included stents (50%), directional atherectomy (24%), and balloon angioplasty (20%). Follow-up was 98.8% complete at 15+/-8 months. Results varied considerably, depending on presentation and treatment. For patient

Effect of temperature on behavior, glycogen content, and mortality in Limnoperna fortunei (Dunker, 1857) (Bivalvia: Mytilidae)

Limnoperna fortunei (Dunker 1857) is a freshwater mussel with physiological tolerance to different environmental conditions, which may explain its success as an invasive species. The role of abiotic factors in its establishment, abundance and projections of risk of further spread into several areas has been studied. These mussels may respond to multiple environmental stressors, such as temperature, through physiological mechanisms, behavioral responses, mortality or some combination of these. The aim of this study was to investigate the behavioral responses (valve closing), glycogen concentrations and mortality of L. fortunei under four different temperatures (5°C, 10°C, 20°C and 30° C) during a chronic test (30 days). Two-way analysis of variance (ANOVA) was used to compare glycogen concentrations across days of the experiment and at the different temperatures. Differences in valve-closing behavior and mortality among temperatures were tested using repeated-measures ANOVA. We observed that most of the mussels maintained at 5°C closed their valves (74.7 ± 15.3%), indicating that they remain inactive at low temperatures. The glycogen levels significantly differed among the temperatures tested. These differences occurred mainly due to the high glycogen values observed in mussels exposed to 10°C. Stability in glycogen concentrations was observed within each particular temperature. The cumulative mortality was higher at extreme temperatures (5°C and 30°C). The ideal temperature for laboratory maintenance and tests is approximately 20°C. Our data also show that L. fortunei can survive and maintain their energy reserves (glycogen) for several days at 5°C, an important feature related to its invasion success