269 research outputs found

    Use of echocardiography in the management of congestive heart failure in the community

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    AbstractObjectives. We evaluated the use and the impact of echocardiography in patients receiving an initial diagnosis of congestive heart failure in Olmsted County, Minnesota, in 1991.Background. The American College of Cardiology/American Heart Association clinical practice guidelines recommend echocardiography in all patients with suspected congestive heart failure. No data are available on use and impact of echocardiography in management of congestive heart failure in a community.Methods. The medical records linkage system of the Rochester Epidemiology Project was used to identify all 216 patients who satisfied the Framingham criteria for congestive heart failure. Of these, 137 (63%) underwent echocardiography within 3 weeks before or after the episode of congestive heart failure (Echo group), and the other 79 patients constitute the No-Echo group.Results. The No-Echo group patients were older (p = 0.022), were more likely to be female (p = 0.072), had milder symptoms (p = 0.001) and were less often hospitalized at diagnosis (p = 0.001). Fewer patients in the No-Echo group were treated with angiotensin-converting enzyme inhibitors (p = 0.001). Advanced age (β‰₯80 years), lower New York Heart Association functional class, absence of a fourth heart sound on examination, absence of cardiomegaly or signs of congestive heart failure on chest radiography and absence of known valve disease were independently related to the decision not to obtain an echocardiogram. Survival after adjustment for age, functional class and gender was lower in the No-Echo group than the Echo group (risk ratio = 0.607, p = 0.017).Conclusions. The underuse of echocardiography appears to be associated with poorer survival and underuse of angiotensin-converting enzyme inhibitor therapy

    First High-Speed Video Camera Observations of a Lightning Flash Associated With a Downward Terrestrial Gamma-Ray Flash

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    In this paper, we present the first high-speed video observation of a cloud-to-ground lightning flash and its associated downward-directed Terrestrial Gamma-ray Flash (TGF). The optical emission of the event was observed by a high-speed video camera running at 40,000 frames per second in conjunction with the Telescope Array Surface Detector, Lightning Mapping Array, interferometer, electric-field fast antenna, and the National Lightning Detection Network. The cloud-to-ground flash associated with the observed TGF was formed by a fast downward leader followed by a very intense return stroke peak current of βˆ’154 kA. The TGF occurred while the downward leader was below cloud base, and even when it was halfway in its propagation to ground. The suite of gamma-ray and lightning instruments, timing resolution, and source proximity offer us detailed information and therefore a unique look at the TGF phenomena

    Long term outcomes of cardiac transplant for immunoglobulin light chain amyloidosis: The Mayo Clinic experience

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    AIM: To determine the outcome of orthotopic heart transplantation (OHT) in immunoglobulin light chain (AL) amyloidosis. METHODS: The medical records of patients with AL who underwent orthotopic heart transplantation at the Mayo Clinic in Rochester Minnesota from 1992 to 2011 were reviewed. Patients met at least one of the following at: New York Heart Association class IV heart failure, ventricular thickness > 15 mm, ejection fraction < 40%. Selection guidelines for heart transplant included age < 60 years, absence of multiple myeloma and significant extra-cardiac organ involvement. Baseline characteristics including age, gender, organ involvement, and New York Heart Association functional class were recorded. Laboratory data, waiting time until heart transplant, and type of treatment of the underlying plasma cell disorder were recorded. Survival from the time of OHT was calculated using Kaplan-Meier survival curves. Survival of patients undergoing OHT for AL was compared to that of non-amyloid patients undergoing OHT during the same time period. RESULTS: Twenty-three patients (median age 53 years) with AL received OHT. There were no deaths in the immediate perioperative period. Twenty patients have died post OHT. For the entire cohort, the median overall survival was 3.5 years (95%CI: 1.2, 8.2 years). The 1-year survival post OHT was 77%, the 2-year survival 65%, and the 5-year survival 43%. The 5-year survival for non-amyloid patients undergoing OHT during the same era was 85%. Progressive amyloidosis contributed to death in twelve patients. Of those without evidence of progressive amyloidosis, the cause of death included complications of autologous hematopoietic stem cell transplantation for 3 patients, post-transplant lymphoproliferative disorder for 2 patients; and for the remaining one death was related to each of the following causes: acute rejection; cardiac vasculopathy; metastatic melanoma; myelodysplastic syndrome; and unknown. Eight patients had rejection at a median of 1.8 mo post OHT (range 0.4 to 4.9 mo); only one patient died of rejection. Median survival of seven patients who achieved a complete hematologic response to either chemotherapy or autologous hematopoietic stem cell transplantation was 10.8 years. CONCLUSION: Our data demonstrate that long term survival after heart transplant is feasible in AL patients with limited extra-cardiac involvement who achieve complete hematologic response

    Observations of the Origin of Downward Terrestrial Gamma-Ray Flashes

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    In this paper we report the first close, high-resolution observations of downward-directed terrestrial gamma-ray flashes (TGFs) detected by the large-area Telescope Array cosmic ray observatory, obtained in conjunction with broadband VHF interferometer and fast electric field change measurements of the parent discharge. The results show that the TGFs occur during strong initial breakdown pulses (IBPs) in the first few milliseconds of negative cloud-to-ground and low-altitude intracloud flashes and that the IBPs are produced by a newly identified streamer-based discharge process called fast negative breakdown. The observations indicate the relativistic runaway electron avalanches (RREAs) responsible for producing the TGFs are initiated by embedded spark-like transient conducting events (TCEs) within the fast streamer system and potentially also by individual fast streamers themselves. The TCEs are inferred to be the cause of impulsive sub-pulses that are characteristic features of classic IBP sferics. Additional development of the avalanches would be facilitated by the enhanced electric field ahead of the advancing front of the fast negative breakdown. In addition to showing the nature of IBPs and their enigmatic sub-pulses, the observations also provide a possible explanation for the unsolved question of how the streamer to leader transition occurs during the initial negative breakdown, namely, as a result of strong currents flowing in the final stage of successive IBPs, extending backward through both the IBP itself and the negative streamer breakdown preceding the IBP

    Repression of Mitochondrial Translation, Respiration and a Metabolic Cycle-Regulated Gene, SLF1, by the Yeast Pumilio-Family Protein Puf3p

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    Synthesis and assembly of the mitochondrial oxidative phosphorylation (OXPHOS) system requires genes located both in the nuclear and mitochondrial genomes, but how gene expression is coordinated between these two compartments is not fully understood. One level of control is through regulated expression mitochondrial ribosomal proteins and other factors required for mitochondrial translation and OXPHOS assembly, which are all products of nuclear genes that are subsequently imported into mitochondria. Interestingly, this cadre of genes in budding yeast has in common a 3β€²-UTR element that is bound by the Pumilio family protein, Puf3p, and is coordinately regulated under many conditions, including during the yeast metabolic cycle. Multiple functions have been assigned to Puf3p, including promoting mRNA degradation, localizing nucleus-encoded mitochondrial transcripts to the outer mitochondrial membrane, and facilitating mitochondria-cytoskeletal interactions and motility. Here we show that Puf3p has a general repressive effect on mitochondrial OXPHOS abundance, translation, and respiration that does not involve changes in overall mitochondrial biogenesis and largely independent of TORC1-mitochondrial signaling. We also identified the cytoplasmic translation factor Slf1p as yeast metabolic cycle-regulated gene that is repressed by Puf3p at the post-transcriptional level and promotes respiration and extension of yeast chronological life span when over-expressed. Altogether, these results should facilitate future studies on which of the many functions of Puf3p is most relevant for regulating mitochondrial gene expression and the role of nuclear-mitochondrial communication in aging and longevity

    RIG-I Is Required for the Inhibition of Measles Virus by Retinoids

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    Vitamin A can significantly decrease measles-associated morbidity and mortality. Vitamin A can inhibit the replication of measles virus (MeV) in vitro through an RARΞ±- and type I interferon (IFN)-dependent mechanism. Retinoid-induced gene I (RIG-I) expression is induced by retinoids, activated by MeV RNA and is important for IFN signaling. We hypothesized that RIG-I is central to retinoid-mediated inhibition of MeV in vitro. We demonstrate that RIG-I expression is increased in cells treated with retinoids and infected with MeV. The central role of RIG-I in the retinoid-anti-MeV effect was demonstrated in the Huh-7/7.5 model; the latter cells having non-functional RIG-I. RAR-dependent retinoid signaling was required for the induction of RIG-I by retinoids and MeV. Retinoid signaling was also found to act in combination with IFN to induce high levels of RIG-I expression. RIG-I promoter activation required both retinoids and MeV, as indicated by markers of active chromatin. IRF-1 is known to be regulated by retinoids and MeV, but we found recruitment of IRF-1 to the RIG-I promoter by retinoids alone. Using luciferase expression constructs, we further demonstrated that the IRF-1 response element of RIG-I was required for RIG-I activation by retinoids or IFN. These results reveal that retinoid treatment and MeV infection induces significant RIG-I. RIG-I is required for the retinoid-MeV antiviral response. The induction is dependent on IFN, retinoids and IRF-1
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