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2.  Differentiating benign from malignant solid breast masses: value of shear wave elastography according to lesion stiffness combined with greyscale ultrasound according to BI-RADS classification 
British Journal of Cancer  2012;107(2):224-229.
The aim of this study was to assess the performance of shear wave elastography combined with BI-RADS classification of greyscale ultrasound images for benign/malignant differentiation in a large group of patients.
One hundred and seventy-five consecutive patients with solid breast masses on routine ultrasonography undergoing percutaneous biopsy had the greyscale findings classified according to the American College of Radiology BI-RADS. The mean elasticity values from four shear wave images were obtained.
For mean elasticity vs greyscale BI-RADS, the performance results against histology were sensitivity: 95% vs 95%, specificity: 77% vs 69%, Positive Predictive Value (PPV): 88% vs 84%, Negative Predictive Value (NPV): 90% vs 91%, and accuracy: 89% vs 86% (all P>0.05). The results for the combination (positive result from either modality counted as malignant) were sensitivity 100%, specificity 61%, PPV 82%, NPV 100%, and accuracy 86%. The combination of BI-RADS greyscale and shear wave elastography yielded superior sensitivity to BI-RADS alone (P=0.03) or shear wave alone (P=0.03). The NPV was superior in combination compared with either alone (BI-RADS P=0.01 and shear wave P=0.02).
Together, BI-RADS assessment of greyscale ultrasound images and shear wave ultrasound elastography are extremely sensitive for detection of malignancy.
PMCID: PMC3394981  PMID: 22691969
breast; ultrasound; elastography; shear wave; imaging
4.  Trend of Income-related Inequality of Child Oral Health in Australia 
Journal of Dental Research  2010;89(9):959-964.
It is important that we monitor socio-economic inequality in health. Inequality in child oral health has been expected to widen because of widening socio-economic inequality. This study aimed to evaluate trends in income-related inequality in caries experience of Australian children. Cross-sectional studies in 1992/93 and 2002/03 collected data on deciduous caries experience of 5- to 10-year-olds and permanent caries experience of 6- to 12-year-olds. Household composition and income was used to calculate quartiles of equivalized income. Slope Index of Inequality (SII), Concentration Index (CI), and regression-based rate ratios were used to quantify income-related inequality and to evaluate trends. Income-related inequality in caries experience was evident regardless of time and dentition. The three indicators of inequality indicate a significant increase in income-related inequality in child deciduous caries experience during the decade. The income inequality in permanent caries experience did not change significantly. Income inequalities increased in deciduous teeth, but not in permanent teeth, among Australian children.
PMCID: PMC3318073  PMID: 20543094
inequality; caries; children; Australia; trend
6.  How can the principles of complexity science be applied to improve the coordination of care for complex pediatric patients? 
Clinical and technological advances in medicine have resulted in more patients requiring multidisciplinary care and coordination of services. This is particularly challenging in pediatrics, given the dependency of children. Coordination of care is a key ingredient of quality care; when suboptimal, clinical outcomes and satisfaction can suffer. In this article we view coordination of care through the lens of complexity science in an effort to find new solutions to this healthcare challenge.
PMCID: PMC2464825  PMID: 16585105
complexity science; coordination of care; quality improvement; children
7.  Plasmid-Mediated Carbapenem-Hydrolyzing Enzyme KPC-2 in an Enterobacter sp. 
Antimicrobial Agents and Chemotherapy  2004;48(11):4438-4440.
A strain of an Enterobacter sp. with reduced susceptibility to imipenem, which produced a plasmid-mediated class A carbapenem-hydrolyzing enzyme, KPC-2 β-lactamase, was isolated from a patient with sepsis at a Boston hospital. This is the first report of the production of a plasmid-encoded KPC-2 β-lactamase by an Enterobacter sp.
PMCID: PMC525415  PMID: 15504876
10.  TCRβ spectratyping in RA: evidence of clonal expansions in peripheral blood lymphocytes 
Annals of the Rheumatic Diseases  1998;57(5):319-322.
OBJECTIVE—To compare the TCRβ repertoire of peripheral blood CD8 enriched (CD8+) and depleted (CD8−) T cells in rheumatoid arthritis (RA) patients and controls using CDR3 length analysis (spectratyping).
METHODS—CD8+ and CD8− T cells were separated from 14 RA patients and 12 controls, using magnetic beads coated with anti-CD8 monoclonal antibodies. cDNA was prepared as the template for amplification with 22 Vβ-Cβ primer pairs. The products were resolved by electrophoresis in an ABI373 sequencer using GENESCAN software. Expansions were identified as dominant CDR3 lengths, where the area underlying the corresponding peak exceeded the sum of the areas of the two adjacent peaks. This method was validated by sequencing 10 samples displaying dominant peaks. The expansion frequencies in RA patients and controls were compared using the χ2 test statistic.
RESULTS—Dominant peaks were evident in several Vβ families. They were more frequent in RA patients in both the CD8+ subset (RA normalised frequency 10.6; control normalised frequency 8.0; p=0.03) and the CD8− subset (RA normalised frequency 2.9; control normalised frequency 1.5; p=0.02). Sequencing of 10 samples exhibiting dominant peaks revealed an unequivocal clonal expansion in nine (90%).
CONCLUSIONS—RA patients exhibited a significantly increased frequency of T cell expansions both in the CD8+ and CD8− subsets. This phenomenon may reflect the proliferation of autoreactive cells, a non-specific expansion of memory T cells in response to pro-inflammatory cytokines or a defect of T cell regulation that predates the onset of RA and may itself predipose to disease.

 Keywords: rheumatoid arthritis; T cell; clonal expansion
PMCID: PMC1752604  PMID: 9741318
11.  Controversies about extended-spectrum and AmpC beta-lactamases. 
Emerging Infectious Diseases  2001;7(2):333-336.
Many clinical laboratories have problems detecting extended-spectrum beta-lactamases (ESBLs) and plasmid-mediated AmpC beta-lactamases. Confusion exists about the importance of these resistance mechanisms, optimal test methods, and appropriate reporting conventions. Failure to detect these enzymes has contributed to their uncontrolled spread and sometimes to therapeutic failures. Although National Committee for Clinical Laboratory Standards recommendations exist for detecting ESBL- producing isolates of Escherichia coli and Klebsiella spp., no recommendations exist for detecting ESBLs in other organisms or for detecting plasmid-mediated AmpC beta-lactamases in any organisms. Clinical laboratories need to have adequate funding, equipment, and expertise to provide a rapid and clinically relevant antibiotic testing service in centers where these resistance mechanisms are encountered.
PMCID: PMC2631719  PMID: 11294735
12.  β-Lactamases Responsible for Resistance to Expanded-Spectrum Cephalosporins in Klebsiella pneumoniae, Escherichia coli, and Proteus mirabilis Isolates Recovered in South Africa 
Although resistance to the expanded-spectrum cephalosporins among members of the family Enterobacteriaceae lacking inducible β-lactamases occurs virtually worldwide, little is known about this problem among isolates recovered in South Africa. Isolates of Klebsiella pneumoniae, Escherichia coli, and Proteus mirabilis resistant to expanded-spectrum cephalosporins recovered from patients in various parts of South Africa over a 3-month period were investigated for extended-spectrum β-lactamase production. Antibiotic susceptibility was determined by standard disk diffusion and agar dilution procedures. Production of extended-spectrum β-lactamases was evaluated by using the double-disk test, and the β-lactamases were characterized by spectrophotometric hydrolysis assays and an isoelectric focusing overlay technique which simultaneously determined isoelectric points and general substrate or inhibitor characteristics. DNA amplification and sequencing were performed to confirm the identities of these enzymes. The P. mirabilis and E. coli isolates were found to produce TEM-26-type, SHV-2, and SHV-5 extended-spectrum β-lactamases. An AmpC-related enzyme which had a pI of 8.0 and which conferred resistance to cefoxitin as well as the expanded-spectrum cephalosporins was found in a strain of K. pneumoniae. This is the first study which has identified organisms producing different extended-spectrum β-lactamases from South Africa and the first report describing strains of P. mirabilis producing a TEM-26-type enzyme. The variety of extended-spectrum β-lactamases found among members of the family Enterobacteriaceae isolated from major medical centers in South Africa is troubling and adds to the growing list of countries where these enzymes pose a serious problem for antimicrobial therapy.
PMCID: PMC105602  PMID: 9624474
13.  Trovafloxacin, a new fluoroquinolone with potent activity against Streptococcus pneumoniae. 
An in vitro study of the activity of 15 antibacterial agents against 202 recent pediatric isolates of Streptococcus pneumoniae from urban and rural Nebraska and rural Kentucky identified trovafloxacin, ofloxacin, clindamycin, and vancomycin as the most active agents and equally active against both penicillin-susceptible and--resistant strains. In contrast, six beta-lactams, three macrolides, and trimethoprim-sulfamethoxazole were less active overall, especially against penicillin-intermediate and--resistant strains. Trovafloxacin inhibited all strains at a concentration of < or = 0.25 micrograms/ml and was 8- to 16-fold more potent than ofloxacin or ciprofloxacin.
PMCID: PMC163735  PMID: 9021213
14.  Beta-lactamases and detection of beta-lactam resistance in Enterobacter spp. 
Enterobacter spp. are becoming increasingly frequent nosocomial pathogens, and beta-lactam-resistant strains are on the increase, especially among isolates recovered from intensive care units. Therefore, a study was designed to characterize the beta-lactamases produced by 80 isolates of E. cloacae, E. aerogenes, E. taylorae, E. gergoviae, E. sakazakii, E. asburiae, and E. agglomerans by induction studies, spectrophotometric hydrolysis assays, and isoelectric focusing. The ability of broth microdilution and disk diffusion susceptibility tests to detect resistance to 16 beta-lactam antibiotics among these species was also assessed. All species except E. agglomerans, E. gergoviae, and some isolates of E. sakazakii were found to produce a Bush group 1 cephalosporinase that was expressed inducibly or constitutively at high levels. In addition, some strains also produced a Bush group 2 beta-lactamase. In comparisons of broth microdilution and disk diffusion tests, disk diffusion tests failed to detect resistance in 1 of 25 isolates resistant to aztreonam and 2 of 30 isolates resistant to ceftazidime. These results indicate that species of Enterobacter can possess a variety of beta-lactamases that are responsible for beta-lactam resistance in this genus and that the disk diffusion test may occasionally miss resistance in some strains.
PMCID: PMC163656  PMID: 8980751
15.  New variant of TEM-10 beta-lactamase gene produced by a clinical isolate of proteus mirabilis. 
A clinical isolate of Proteus mirabilis was found to produce a new variant of the TEM-10 beta-lactamase gene. This is the first report of TEM-10 production by P. mirabilis and the first report of extended-spectrum beta-lactamase production by an isolate of this species recovered in the United States.
PMCID: PMC162712  PMID: 7625817
16.  Dissociated resistance among fluoroquinolones. 
A panel of 190 clinical isolates of staphylococci, enterococci, Streptococcus pneumoniae, members of the family Enterobacteriaceae, and nonfermentative gram-negative bacilli were examined by agar dilution tests for susceptibility to five quinolones and six nonquinolone agents. Members of the family Enterobacteriaceae and staphylococci were divided into subgroups according to their ciprofloxacin susceptibilities and were analyzed for cross-resistance to OPC-17116, ofloxacin, and temafloxacin. Although the MICs of all quinolones increased with increasing ciprofloxacin resistance, the MICs of OPC-17116, ofloxacin, and temafloxacin tended to increase less than those of ciprofloxacin, indicating that these agents were less affected by the mechanisms of quinolone resistance. An exception to this was the activity of OPC-17116 against highly ciprofloxacin-resistant staphylococci (MIC, > or = 8 micrograms/ml). Some of these staphylococci were equally resistant to OPC-17116, while others were fourfold more susceptible to ciprofloxacin than to OPC-17116. This indicated that in some strains OPC-17116 was more affected than ciprofloxacin by certain mechanisms responsible for high-level resistance. This was paralleled in single-step mutational studies in which 7 of 19 staphylococcal mutants exhibited large decreases in susceptibility to OPC-17116 (128- to 256-fold) but only modest decreases in susceptibility (4- to 16-fold) to the other quinolones. Such mutants were selected only from strains moderately resistant to ciprofloxacin (MIC, > or = 1 microgram/ml). This heterogeneity in the resistance of staphylococci to fluoroquinolones has not been seen previously and suggests that certain mechanisms of resistance in staphylococci affect OPC-17116 to a much greater extent than other quinolones.
PMCID: PMC284690  PMID: 7811025
17.  Use of ketamine in prolonged entrapment. 
This paper discusses the advantages of ketamine analgesia in the management of trapped patients after serious incidents. Four case histories and a review of the literature lead us to the conclusion that ketamine is the drug of choice in these situations.
PMCID: PMC1342430  PMID: 7804588
18.  Read clinical terms and child health. 
Archives of Disease in Childhood  1994;71(3):272-274.
PMCID: PMC1029988  PMID: 7979507
19.  Ceftazidime resistance in Hafnia alvei. 
Two morphotypes of Hafnia alvei differed in their susceptibilities to beta-lactam antibiotics. Both produced an inducible Bush group 1 beta-lactamase. Hyperinducibility of this enzyme was associated with reduced susceptibility in one morphotype.
PMCID: PMC187971  PMID: 8328790
20.  Bronchial gland duct ectasia in fatal bronchial asthma: association with interstitial emphysema. 
Journal of Clinical Pathology  1989;42(10):1026-1031.
To determine the incidence of bronchial gland duct ectasia in fatal asthma and its association with interstitial emphysema, the histological features of 72 patients in whom death was considered to be due to asthma, and 72 matched control subjects in whom sudden death was not attributed to asthma, were reviewed. In all cases and controls, sections of two or more blocks of lung tissue stained with haematoxylin and eosin were obtained at necropsy. Bronchial gland duct ectasia was diagnosed if there was more than one abnormally dilated epithelial lined protrusion from a bronchus, extending through the smooth muscle layer. A histological diagnosis of asthma was made if four of the five following criteria were present: mucus plugging, basement membrane thickening, epithelial shedding, submucosal eosinophil leucocyte infiltration and smooth muscle hypertrophy. A histological diagnosis of asthma was made in 53 of 72 clinical cases of fatal asthma and in five of 72 control subjects. Interstitial emphysema was present in 10 clinical cases of fatal asthma, all of whom had bronchial gland duct ectasia and a histological diagnosis of asthma. Interstitial emphysema was not observed in control subjects. It is concluded that bronchial gland duct ectasia is a common histological feature of severe asthma, and that interstitial emphysema may be consequent on rupture of these dilated gland ducts.
PMCID: PMC501858  PMID: 2584403
21.  Detection of extended-spectrum beta-lactamases in members of the family Enterobacteriaceae: comparison of the double-disk and three-dimensional tests. 
The three-dimensional and clavulanate double-disk potentiation tests were compared as procedures for the detection of extended-spectrum beta-lactamase production in 32 strains of Escherichia coli and Klebsiella pneumoniae, 31 of which produced TEM-1, TEM-2, TEM-3, TEM-4, TEM-5, TEM-7, TEM-8, TEM-9, TEM-10, TEM-12, TEM-101, SHV-1, SHV-2, SHV-3, SHV-4, SHV-5, CAZ-2, MIR-1, or an unidentified extended-spectrum beta-lactamase with a pI of 5.95, with some strains producing multiple beta-lactamases. The three-dimensional test, which was performed in conjunction with a routine disk diffusion test, detected extended-spectrum beta-lactamase production in 26 of 28 (93%) of the strains that produced extended-spectrum beta-lactamases. The clavulanate double-disk potentiation test detected extended-spectrum beta-lactamases in only 22 of the 28 strains (79%) when it was performed as currently recommended. The three-dimensional test, when performed in conjunction with the disk diffusion test, offered the advantages of providing simultaneous information about both antibiotic susceptibility and extended-spectrum beta-lactamase production, coupled with a greater sensitivity and earlier detection of extended-spectrum beta-lactamases.
PMCID: PMC192203  PMID: 1416878
23.  In vitro studies with five quinolones: evidence for changes in relative potency as quinolone resistance rises. 
Antimicrobial Agents and Chemotherapy  1991;35(11):2329-2334.
A panel of 203 staphylococci, Enterobacteriaceae, Pseudomonas aeruginosa, and miscellaneous nonfermentative gram-negative bacilli were chosen for their various susceptibilities to ciprofloxacin. On the basis of agar dilution susceptibilities, each of the four taxonomic groups was divided into ciprofloxacin-susceptible, moderately resistant, and highly resistant subgroups, and each subgroup was then further analyzed for its susceptibility to the fluoroquinolones CI-960, CI-990, sparfloxacin, and ofloxacin. Although the MICs of each quinolone increased as ciprofloxacin resistance increased, the potency of CI-960 appeared to increase relative to the potencies of the other quinolones. Similarly, the MICs of sparfloxacin and ofloxacin appeared to be less affected by ciprofloxacin resistance than were the MICs of ciprofloxacin or CI-990. Single-step mutants of representative clinical isolates with different levels of ciprofloxacin resistance were selected to determine whether the study quinolones differed in their propensity to select resistant mutants and whether the presence of preexisting ciprofloxacin resistance influenced the subsequent development of resistance. Each of the five fluoroquinolones and nalidixic acid selected mutants that exhibited generally modest decreases in quinolone susceptibility (4- to 16-fold). However, CI-960 inhibited significantly more mutants (80%) than did the other quinolones (39 to 59%) at a concentration of 1 microgram/ml. The presence of preexisting ciprofloxacin resistance appeared to be associated with higher mutational frequencies in coagulase-negative staphylococci exposed to each of the fluoroquinolones and in Serratia marcescens exposed to nalidixic acid. Preexisting ciprofloxacin resistance did not influence the development of resistance in the strains of Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, or Pseudomonas aeruginosa that were studied. The results of this study suggest that quinolones are not affected equally by all resistance mechanisms, and although each one can select mutants, some quinolones may be active against these mutants at clinically achievable concentrations.
PMCID: PMC245380  PMID: 1804005
24.  High-level resistance to cefotaxime and ceftazidime in Klebsiella pneumoniae isolates from Cleveland, Ohio. 
Two isolates of Klebsiella pneumoniae possessing both TEM-1 and SHV-2 beta-lactamases were isolated from patients at the Cleveland Clinic in 1988. The beta-lactamases were discriminated and identified by using substrate hydrolysis data and an isoelectric focusing procedure in which the gel was overlaid with beta-lactamase inhibitors.
PMCID: PMC245146  PMID: 1854155
25.  Beta-lactamase production in members of the family Enterobacteriaceae and resistance to beta-lactam-enzyme inhibitor combinations. 
Recent reports that members of the family Enterobacteriaceae that produce high levels of certain beta-lactamases are often resistant to ticarcillin-clavulanate prompted this study to assess the relationship between type and amount of enzyme produced and susceptibility to ticarcillin-clavulanate, piperacillin-tazobactam, and cefoperazone-sulbactam. Agar dilution MICs were determined by using 73 strains of Enterobacteriaceae that produced a single beta-lactamase that had been characterized and quantified and a beta-lactamase-negative control strain of Escherichia coli. For E. coli and Klebsiella pneumoniae, MICs of each combination increased as levels of TEM, SHV-1, or class IV enzymes increased. However, the percentage of strains that were resistant was highest for ticarcillin-clavulanate (32%), with only 18 and 6% resistant to piperacillin-tazobactam and cefoperazone-sulbactam, respectively. Strains producing PSE-1, regardless of level, were resistant or moderately susceptible to ticarcillin-clavulanate but were susceptible to piperacillin-tazobactam and cefoperazone-sulbactam. HMS-1 and OHIO-1 beta-lactamases were associated with resistance to ticarcillin-clavulanate and piperacillin-tazobactam, respectively. High levels of class IV enzymes in Klebsiella oxytoca were associated with resistance to all three combinations. These results indicate that the level and type of beta-lactamase produced by members of the family Enterobacteriaceae are important determinants of susceptibility to beta-lactam-inhibitor combinations, especially ticarcillin-clavulanate.
PMCID: PMC171654  PMID: 2344169

Results 1-25 (31)