Analysis of M/G/1/SRPT under transient overload

This short paper contains an approximate analysis for the M/G/1/SRPT queue under alternating periods of overload and low load. The result in this paper along with several other results on systems under transient overload are contained in our recent technical report [2]

Characteristics of a Large Shared Memory Production Workload

This paper characterizes the production workload that highly utilizes the NCSA Origin 2000. The characterization includes the distributions of job interarrival time, requested number of processors, requested memory, requested runtime, actual runtime as a fraction of requested runtime, and the ratio of memory usage to memory request. Conditional distributions are defined as needed for generating a synthetic workload with the same characteristics, including the key correlations observed among the job parameters. Characteristics of the O2K workload that differ from previously reported production workload characteristics are also noted.

Reduction in leukotriene B4 generation by bronchoalveolar lavage cells in asthma.

BACKGROUND--Leukotrienes are inflammatory mediators implicated in the pathogenesis of asthma. The capacity of inflammatory cells within the airways to generate leukotrienes may be altered in asthma. This hypothesis was tested using bronchoalveolar lavage (BAL) to sample cells within the airways from atopic asthmatic and normal subjects, and by measuring their capacity to generate leukotriene B4 (LTB4) and leukotriene C4 (LTC4) in response to A23187, a potent stimulus of leukotriene generation. METHODS--Bronchoalveolar lavage was performed in 12 mild asymptomatic atopic asthmatic patients and 12 normal subjects. Mixed BAL cell aliquots (approximately 80% alveolar macrophages) were incubated with 0-20 microM A23187 for 10 minutes and with 4 microM A23187 for 0-30 minutes, and leukotrienes were measured by radioimmunoassay and high performance liquid chromatography. RESULTS--Mixed BAL cells from asthmatic subjects generated less LTB4 than cells from normal subjects in dose response and time course experiments (area under the curve 81.5 (0.0-228.5) ng.min.10(-6) cells in asthmatic subjects and 197.9 (13.9-935.6) ng.min.10(-6) cells in normal subjects. There were no differences in LTC4 generation between BAL cells from asthmatic and normal subjects. CONCLUSIONS--Generation of LTB4 by BAL cells from atopic asthmatic subjects in response to A23187 was reduced. As the alveolar macrophage is the major source of LTB4 in BAL cells, these results probably reflect reduced generation of LTB4 by alveolar macrophages from asthmatic patients. This may be a consequence of monocyte migration into the lung, or altered alveolar macrophage function in asthma, or both

Moxifloxacin Safety

BACKGROUND: Moxifloxacin, a fluoroquinolone antibiotic, is used for the treatment of respiratory tract, pelvic inflammatory disease, skin, and intra-abdominal infections. Its safety profile is considered favorable in most reviews but has been challenged with respect to rare but potentially fatal toxicities (e.g. hepatic, cardiac, or skin reactions). OBJECTIVE: To analyze and compare the safety profile of moxifloxacin versus comparators in the entire clinical database of the manufacturer. SETTING: Data on the valid-for-safety population from phase II–IV actively controlled studies (performed between 1996 and 2010) were analyzed. Studies were either double blind (n = 22 369) or open label (n = 7635) and included patients with indications that have been approved in at least one country [acute bacterial sinusitis, acute exacerbation of chronic bronchitis, community-acquired pneumonia, uncomplicated pelvic inflammatory disease, complicated and uncomplicated skin and skin structure infections, and complicated intra-abdominal infections] (n = 27 824) and patients with other indications (n = 2180), using the recommended daily dose (400 mg) and route of administration (oral, intravenous/oral, intravenous only). The analysis included patients at risk (age ≥65 years, diabetes mellitus, renal impairment, hepatic impairment, cardiac disorders, or body mass index <18 kg/m(2)). Patients with known contraindications were excluded from enrollment by study protocol design, but any patient having entered a study, even if inappropriately, was included in the analysis. MAIN OUTCOME MEASURE: Crude incidences and relative risk estimates (Mantel-Haenszel analysis) of patients with any adverse event (AE), adverse drug reaction (ADR), serious AE (SAE), serious ADR (SADR), treatment discontinuation due to an AE or ADR, and fatal outcomes related to an AE or ADR. RESULTS: Overall incidence rates of AEs were globally similar in the moxifloxacin and comparator groups. By filtering the data for differences in disfavor of moxifloxacin (i) at ≥2.5% for events with an incidence ≥2.5% or at ≥2-fold for events with an incidence <2.5% in one or both groups and (ii) affecting ≥10 patients in either group, we observed slightly more (i) AEs in double-blind intravenous-only and open-label oral studies, (ii) SAEs in double-blind intravenous-only studies, (iii) ADRs and SADRs in open-label oral studies, (iv) SADRs in open-label intravenous/oral studies, and (v) premature discontinuation due to AEs in open-label intravenous-only studies. The actual numbers of SADRs (in all studies) were small, with clinically relevant differences noted only in intravenous/oral studies and mainly driven by ‘gastrointestinal disorders’ (15 versus 7 patients) and ‘changes observed during investigations’ (23 versus 7 patients [asymptomatic QT prolongation: 11 versus 4 patients in double-blind studies]). Analysis by comparator (including another fluoroquinolone) did not reveal medically relevant differences, even in patients at risk. Incidence rates of hepatic disorders, tendon disorders, clinical surrogates of QT prolongation, serious cutaneous reactions, and Clostridium difficile-associated diarrhea were similar with moxifloxacin and comparators. CONCLUSION: The safety of moxifloxacin is essentially comparable to that of standard therapies for patients receiving the currently registered dosage and for whom contraindications and precautions of use (as in the product label) are taken into account