57 research outputs found
Genetic diversity of ST5 Staphylococcus aureus isolated from swine veterinarians in the USA
The term livestock associated methicillin resistant Staphylococcus aureus (LA-MRSA) has been synonymous with sequence type ST398 since the identification of this lineage of MRSA in Holland. Subsequent research indicates borader genetic diversity of MRSA strains in swine, with MRSA variants belonging to MLST sequence type ST9, and ST5 also being reported in studies of swine in varioust countries
Longitudinal study of Staphylococcus aureus and MRSA colonization of US swine veterinarians
Patterns of detection of S. aureus are being evaluated in a longitudinal study of a cohort of 67 swine veterinarians in the USA. This report presents interim data from the initial period of the study. Overall, approximately 70% of sampling events yielded S. aureus in nasal swabs from veterinarians, and 8% yielded MRSA isolates
Phase II randomized trial of neoadjuvant metformin plus letrozole versus placebo plus letrozole for estrogen receptor positive postmenopausal breast cancer (METEOR)
This is an Open Access article distributed under the terms of the Creative
Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited.Abstract
Background
Neoadjuvant endocrine therapy with an aromatase inhibitor has shown efficacy comparable to that of neoadjuvant chemotherapy in patients with postmenopausal breast cancer. Preclinical and clinical studies have shown that the antidiabetic drug metformin has anti-tumor activity. This prospective, multicenter, phase II randomized, placebo controlled trial was designed to evaluate the direct anti-tumor effect of metformin in non-diabetic postmenopausal women with estrogen-receptor (ER) positive breast cancer.
Methods/Design
Patients meeting the inclusion criteria and providing written informed consent will be randomized to 24 weeks of neoadjuvant treatment with letrozole (2.5 mg/day) and either metformin (2000 mg/day) or placebo. Target accrual number is 104 patients per arm. The primary endpoint will be clinical response rate, as measured by calipers. Secondary endpoints include pathologic complete response rate, breast conserving rate, change in Ki67 expression, breast density change, and toxicity profile. Molecular assays will be performed using samples obtained before treatment, at week 4, and postoperatively.
Discussion
This study will provide direct evidence of the anti-tumor effect of metformin in non-diabetic, postmenopausal patients with ER-positive breast cancer.
Trial registration
ClinicalTrials.gov Identifier
NCT0158936
Low prevalence of methicillin resistant Staphylococcus aureus but high prevalence of multidrug resistant Staphylococcus aureus in pigs in the USA
It has been suggested that the emergence of livestock associated MRSA in swine may be a consequence of feeding antibiotics and/or zinc to control swine diseases or promote growth. However, the dynamics and health implications of interspecies transmission of MRSA from pigs to humans is still incompletely understood. To address these questions, better understanding is required of the broader ecology of S. aureus in pigs, including MRSA. To obtain more representative data on the prevalence and characterization of S. aureus, including MRSA, we collected nasal samples from growing pigs on 36 swine farms across 11 states in the USA. All isolates were spa typed, and MLST typing was conducted on selected isolates of each spa type. Antimicrobial and zinc susceptibility testing was performed on a subset of 130 isolates selected purposively to maximize the diversity of isolates by farm and spa type. S. aureus was detected on 35 of the 36 farms, and from 76% of pigs sampled, but no MRSA were found apart from one farm of known status that was included as a MRSA positive control. A total of 33 spa types were detected, with the most prevalent being t337 (ST9), t034 (ST398) and t002 (ST5). Antimicrobial resistance testing for 18 antibiotics showed that resistance was most common to spectinomycin (100%), tetracycline (94%), clindamycin (75%) and penicillin (72%), and a majority of isolates were resistant to 5 or more antibiotics (multidrug resistant S. aureus, MDRSA). Only ST398 MRSA isolates from the positive control farm were positive for the czrC gene, although phenotypic resistance to zinc was observed in some MSSA isolates. These results support earlier studies indicating a relatively low prevalence of MRSA in pigs in the USA, but a high prevalence of MDRSA. The data also concur with the hypothesis that zinc resistance may be more strongly associated with MRSA in swine reservoirs than is resistance of antibiotics such as tetracyclines.</p
Circuit Optimization Method to Reduce Disturbances in Poly-Si 1T-DRAM
A capacitorless one-transistor dynamic random-access memory device (1T-DRAM) is proposed to resolve the scaling problem in conventional one-transistor one-capacitor random-access memory (1T-1C-DRAM). Most studies on 1T-DRAM focus on device-level operation to replace 1T-1C-DRAM. To utilize 1T-DRAM as a memory device, we must understand its circuit-level operation, in addition to its device-level operation. Therefore, we studied the memory performance depending on device location in an array circuit and the circuit configuration by using the 1T-DRAM structure reported in the literature. The simulation results show various disturbances and their effects on memory performance. These disturbances occurred because the voltages applied to each device during circuit operation are different. We analyzed the voltage that should be applied to each voltage line in the circuit to minimize device disturbance and determine the optimized bias condition and circuit structure to achieve a large sensing margin and realize operation as a memory device. The results indicate that the memory performance improves when the circuit has a source line and the bias conditions of the devices differ depending on the write data at the selected device cell. Therefore, the sensing margin of the 1T-DRAM used herein can expectedly be improved by applying the proposed source line (SL) structure
A Unified Current-Voltage Model for Metal Oxide-Based Resistive Random-Access Memory
Resistive random-access memory (RRAM) is essential for developing neuromorphic devices, and it is still a competitive candidate for future memory devices. In this paper, a unified model is proposed to describe the entire electrical characteristics of RRAM devices, which exhibit two different resistive switching phenomena. To enhance the performance of the model by reflecting the physical properties such as the length index of the undoped area during the switching operation, the Voltage ThrEshold Adaptive Memristor (VTEAM) model and the tungsten-based model are combined to represent two different resistive switching phenomena. The accuracy of the I–V relationship curve tails of the device is improved significantly by adjusting the ranges of unified internal state variables. Furthermore, the unified model describes a variety of electrical characteristics and yields continuous results by using the device’s current-voltage relationship without dividing its fitting conditions. The unified model describes the optimized electrical characteristics that reflect the electrical behavior of the device
Genetic diversity of ST5 Staphylococcus aureus isolated from swine veterinarians in the USA
The term livestock associated methicillin resistant Staphylococcus aureus (LA-MRSA) has been synonymous with sequence type ST398 since the identification of this lineage of MRSA in Holland. Subsequent research indicates borader genetic diversity of MRSA strains in swine, with MRSA variants belonging to MLST sequence type ST9, and ST5 also being reported in studies of swine in varioust countries.</p
Mesothelial cyst of the spleen mimicking a metastasis: a case report
Mesothelial cyst of the spleen is a developmental disorder. Previous reports have elaborated on the radiological features of splenic mesothelial cysts as being unilocular with a smooth and well-defined margin. However, due to its rarity, it is unclear whether these characteristics are representative and specific for the diagnosis of mesothelial cysts. Herein, this case report presents an atypical case of splenic mesothelial cyst mimicking a malignant tumour, especially splenic metastasis in a 66-year-old woman with ascending colon cancer. Due to an overlapping imaging finding of hypodense splenic lesions, and considering the clinical history, a mesothelial cyst that developed as a multilocular hypodense mass from an ill-defined small nodule was inevitably misdiagnosed as metastasis. Although rare, it is important to consider the possibility of mesothelial cyst in a patient with multilocular hypodense lesions of the spleen
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