California State University, Long Beach

About: California State University, Long Beach is a education organization based out in Long Beach, California, United States. It is known for research contribution in the topics: Population & Poison control. The organization has 10036 authors who have published 13933 publications receiving 377394 citations. The organization is also known as: Cal State Long Beach & Long Beach State.

The Boron Efflux Transporter ROTTEN EAR Is Required for Maize Inflorescence Development and Fertility

Abstract: Although boron has a relatively low natural abundance, it is an essential plant micronutrient. Boron deficiencies cause major crop losses in several areas of the world, affecting reproduction and yield in diverse plant species. Despite the importance of boron in crop productivity, surprisingly little is known about its effects on developing reproductive organs. We isolated a maize (Zea mays) mutant, called rotten ear (rte), that shows distinct defects in vegetative and reproductive development, eventually causing widespread sterility in its inflorescences, the tassel and the ear. Positional cloning revealed that rte encodes a membrane-localized boron efflux transporter, co-orthologous to the Arabidopsis thaliana BOR1 protein. Depending on the availability of boron in the soil, rte plants show a wide range of phenotypic defects that can be fully rescued by supplementing the soil with exogenous boric acid, indicating that rte is crucial for boron transport into aerial tissues. rte is expressed in cells surrounding the xylem in both vegetative and reproductive tissues and is required for meristem activity and organ development. We show that low boron supply to the inflorescences results in widespread defects in cell and cell wall integrity, highlighting the structural importance of boron in the formation of fully fertile reproductive organs.

Interferon-γ Release Assays for Diagnosing Mycobacterium tuberculosis Infection in Renal Dialysis Patients

Abstract: Background and objectives: End-stage renal disease (ESRD) patients are at high risk for tuberculosis (TB). IFN-γ release assays that assess immune responses to specific TB antigens offer potential advantages over tuberculin skin testing (TST) in screening such patients for Mycobacterium tuberculosis infection. This study sought to determine whether IFN-γ release assay results are more closely associated with recent TB exposure than TST results. Design, setting, participants, and measures: Prospective cohort investigation of patients at a hemodialysis center with a smear-positive case of TB. Patients without a history of TB underwent initial and repeat testing with TST, and with the IFN-γ assays QuantiFERON-TB Gold® (QFT-G) and ELISPOT test. Outcome measures included the prevalence of positive test results, identification of factors associated with positive results, and test result discordance. Results: A total of 100 (47% foreign born; median age, 55 yr; age range, 18 to 83 yr) of 124 eligible patients were enrolled. Twenty-six persons had positive TST results, 21 had positive QFT-G results, and 27 had positive ELISPOT results. Patients with TB case contact were likely to have a positive QFT-G result (P = 0.02) and ELISPOT results (P = 0.04), whereas TB case contact was not associated with positive TST results (P = 0.7). Positive TST results were associated with foreign birth (P = 0.04) and having had a TST in the previous year (P = 0.04). Conclusions: Positive IFN-γ assay results were more closely associated with recent TB exposure than were positive TST results. QFT-G and ELISPOT might offer a better method for detecting TB infection in ESRD patients.

Experiences with long acting injectable ART: A qualitative study among PLHIV participating in a Phase II study of cabotegravir + rilpivirine (LATTE-2) in the United States and Spain.

Abstract: Challenges with adherence to daily oral antiretroviral therapy (ART) among people living with HIV (PLHIV) have stimulated development of injectable long-acting (LA) regimens. We conducted 39 in-depth interviews with participants and providers in a Phase IIb study (LATTE-2) evaluating an injectable LA regimen in the U.S. and Spain. Interviews exploring participant and provider attitudes and experiences with LA versus oral ART were audiotaped, transcribed and analyzed using thematic content analysis. Participants described the convenience of LA injections versus daily pills and emotional benefits such as minimized potential for HIV disclosure and eliminating the "daily reminder of living with HIV." Providers recognized benefits but cautioned that LA candidates still need to adhere to clinic visits for injections and raised questions around ongoing clinical management. LA was seen as preferable to daily oral ART among PLHIV. Further research is needed regarding appropriate candidates, including with women and "non-adherent" populations across settings.

On a possible epigenetic mechanism(s) of tumor cell heterogeneity. The role of DNA methylation.

Abstract: It is a currently well-accepted view that both human and animal tumors consist of heterogeneous rather than homogeneous populations of tumor cells (reviewed in 1-3). This cellular diversity within individual tumors represents the most formidable obstacle to the development of any uniform approach to the therapy of neoplasia (2-5). It is therefore essential to understand the mechanisms by which tumor diversity evolves, for without such knowledge the design of effective therapeutic protocols will remain exceedingly difficult. Our current understanding of the evolution of tumor heterogeneity is based primarily on the hypotheses put forth by Foulds (6) and Nowell (7). Nowell has argued that tumor cells are inherently genetically unstable and as such mutate at a much higher rate than normal cells. These random somatic mutations result in the generation of tumor cell mutants, which, to survive and expand in number (leading to new clones), must have a selective growth advantage over their predecessors. Only clones possessing such selective advantages will ultimately survive host defenses; lethal mutations, or those enhancing the cells susceptibility to host attack, would result in clonal elimination or attenuation. This results in what has been called ' tumor progression' (6), in that the clonal composition of a tumor continually changes so as to become dominated by cells with ever-increasing growth advantages. The outcome is the evolution of an increasingly malignant tumor that is more resistant to therapy. Fundamental to Nowell's hypothesis is the view that tumors are intrinsically 'genetically unstable' and thus more prone to undergo genetic mutation (7); for without such instability, one could not explain the apparent high frequency and diversity of tumor clones. While there is some support for a tumor cell hypermutable state (7,8), there are reasons for questioning the view of somatic mutations being the only explanation for tumor diversity. NoweU recognized this problem by observing the paucity of new (i.e., mutation dependent) gene products in tumor cells (7). Alterations observed in tumor cells generally reflect the unexpected expression of pre-existing gene products rather than the development of new ones. He further noted (as did Holliday see below) that mutation should result in genetic alterations which are not readily reversible; yet both in vivo and in vitro models have on occasion demonstrated that tumor cells can differentiate (see below). Nowell attempted to resolve these questions by postulating the existence of mutational changes in regulatory genes, chromosomal rearrangement events, or interference in chromosomes by integrated viral genomes. We herein offer an alternative, but not mutually exclusive, explanation based not on structural gene changes but rather on what have been called 'epigenetic' changes. Our

The effects of processing techniques on the mechanical properties of bone-anterior cruciate ligament-bone allografts: An experimental study in goats

Abstract: There has been a growing interest in the use of allo grafts as ACL substitutes. Allografts are often freeze dried to increase shelf storage time and sterilized with ethylene oxide. This study was conducted to determine the effect of a specific ethylene oxide sterilization pro cedure and freeze drying process on the initial mechan ical properties of femur-ACL-tibia preparations. Twelve knees (stifle joints) from six mature goats were divided into two groups (one knee of pair to each group). Knees were cleaned of all soft tissue except for the anterior cruciate, posterior cruciate, and collateral ligaments. Group 1 was sterilized with ethylene oxide (simulating clean procurement) then freeze dried. Group 2 was freeze dried only (simulating sterile procurement). The knees were rehydrated and then tested in tension to failure to determine their structural mechanical proper ties. The ethylene oxide-freeze dried specimens (Group 1) had a mean maximum load before failure of 2059 ± 273 newtons (N) (± SE) which wa...