Genetic diversity of fluoroquinolone-nonsusceptible Streptococcus pneumoniae clinical isolates and the first identification of serotype 20B in China

The purpose of this study was to investigate the genetic characteristics of fluoroquinolone-nonsusceptible Streptococcus pneumoniae clinical isolates in China. A total of 377 S. pneumoniae clinical isolates, including 307 pediatric strains and 70 adult strains, were collected from eight centers in China. The minimal inhibitory concentrations (MICs) of 10 antimicrobial agents were determined by agar dilution. Multilocus sequence typing (MLST), serotyping, and quinolone resistance-determining region (QRDR) variations were conducted in levofloxacin-nonsusceptible isolates by polymerase chain reaction (PCR)-based methods. Seven levofloxacin-nonsusceptible isolates were found, with an overall resistance rate of 1.9 % (7/377) and 8.6 % (6/70) in adults. Sequence analyses of parC, gyrA, and parE QRDRs in levofloxacin-resistant isolates demonstrated mutations in dual target sites at the hot spots. These seven strains represented multiple clones: two strains were serotype 19F (Taiwan(19F)-14) and MLST clonal complex (CC) 271/320, two were typed as 23F (Spain(23F)-1) and CC81, two were determined as serotype 20B and a new sequence type of ST6935, and one non-serotypeable pediatric strain belonged to a new sequence type of ST6946. Two serotype 19F strains possessed a variety of characteristic alterations of viridans group streptococci in gyrA (Ser114Gly) or parC (Ser52Gly, Asn91Asp). Fluoroquinolone-nonsusceptible S. pneumoniae isolates showed a substantial degree of genetic diversity and belonged to pre-existing epidemic clones together with native clones. S. pneumoniae strains with serotype 20B was recovered for the first time to be associated with levofloxacin resistance in China.

Tumor vascular disrupting agent 5,6-dimethylxanthenone-4-acetic acid inhibits platelet activation and thrombosis via inhibition of thromboxane A2 signaling and phosphodiesterase

BACKGROUND

5,6-Dimethylxanthenone-4-acetic acid (DMXAA) is a tumor vascular disrupting agent under clinical trials as an adjacent antitumor agent. DMXAA is structurally similar to flavone-8-acetic acid (FAA), an old tumor vascular disrupting agent with antiplatelet and antithrombotic effects. In contrast to FAA, which causes bleeding in tumor patients, no bleeding has been reported in patients receiving DMXAA. Whether DMXAA also affects platelet function is not clear.

OBJECTIVES

To determine the effects of DMXAA on platelet function and explore the underlying mechanisms.

METHODS AND RESULTS

DMXAA concentration-dependently inhibited human platelet aggregation and ATP release induced by U46619, arachidonic acid, ADP, collagen, or ristocetin. Furthermore, DMXAA inhibited phosphorylation of Erk1/2 and Akt downstream of thromboxane A2 signaling inhibition. DMXAA also inhibited human platelet phosphodiesterase. The antiplatelet effects were further confirmed using mice administered DMXAA intravenously. DMXAA dramatically inhibited thrombus formation in FeCl3 -injured mouse mesenteric arterial thrombus model and laser-injured mouse cremaster arteriole thrombus model. Notably, at a dose exhibiting antithrombotic effects similar to those of clopidogrel in mice, DMXAA did not significantly increase bleeding.

CONCLUSIONS

For the first time, we found that tumor vascular disrupting agent DMXAA has potent antiplatelet and antithrombotic effects without any bleeding diathesis. As DMXAA inhibits platelet activity with safe profile, DMXAA could be used as an efficacious and safe antiplatelet drug.

Racial disparities in economic and clinical outcomes of pregnancy among Medicaid recipients

To explore racial-ethnic disparities in adverse pregnancy outcomes among Medicaid recipients, and to estimate excess Medicaid costs associated with the disparities. Cross-sectional study of adverse pregnancy outcomes and Medicaid payments using data from Medicaid Analytic eXtract files on all Medicaid enrollees in fourteen southern states. Compared to other racial and ethnic groups, African American women tended to be younger, more likely to have a Cesarean section, to stay longer in the hospital and to incur higher Medicaid costs. African-American women were also more likely to experience preeclampsia, placental abruption, preterm birth, small birth size for gestational age, and fetal death/stillbirth. Eliminating racial disparities in adverse pregnancy outcomes (not counting infant costs), could generate Medicaid cost savings of $114 to $214 million per year in these 14 states. Despite having the same insurance coverage and meeting the same poverty guidelines for Medicaid eligibility, African American women have a higher rate of adverse pregnancy outcomes than White or Hispanic women. Racial disparities in adverse pregnancy outcomes not only represent potentially preventable human suffering, but also avoidable economic costs. There is a significant financial return-on-investment opportunity tied to eliminating racial disparities in birth outcomes. With the Affordable Care Act expansion of Medicaid coverage for the year 2014, Medicaid could be powerful public health tool for improving pregnancy outcomes.

Evaluation of a catalase-based urine test for the detection of urinary tract infection in dogs and cats

BACKGROUND

Bacterial infection of the urinary tract is a common disorder in dogs and cats. Although microscopic examination of urine sediment is routinely used to screen for infection, this test can lack sensitivity or require expertise. A reliable in-clinic screening test would be a useful adjunct for the identification of dogs and cats with bacterial urinary tract infection (UTI).

HYPOTHESIS

That a catalase-based urine test (Accutest Uriscreen™) is a more sensitive screening test for UTI in dogs and cats than urine microscopic sediment examination.

ANIMALS

One hundred and sixty client-owned dogs and cats.

METHODS

Surplus urine from animals presented to a veterinary teaching hospital was used in this prospective observational study. A routine urinalysis, aerobic bacterial culture, and the Uriscreen test were performed on cystocentesis samples. Sensitivity and specificity with 95% confidence intervals and positive and negative likelihood ratios were calculated for Uriscreen and microscopic sediment examination using culture results as the gold standard.

RESULTS

Bacterial culture was positive in 27/165 (16.4%) samples. The sensitivity, specificity, and positive and negative likelihood ratios for the Uriscreen were 89%, 71%, 3.0, and 0.15, respectively. Sensitivity, specificity, and positive and negative likelihood ratios for urine sediment microscopic examination were 78%, 90%, 7.8, and 0.24, respectively.

CONCLUSIONS AND CLINICAL IMPORTANCE

The Uriscreen is a more sensitive screening test for UTI in dogs and cats than sediment examination; however, the urine sediment examination was more specific. A negative Uriscreen result helps exclude UTI; however, urine bacterial culture is still necessary to exclude or confirm UTI in all cases.

Mechanical comparison between lengthened and short sacroiliac screws in sacral fracture fixation: a finite element analysis

OBJECTIVE

To compare the stability of lengthened sacroiliac screw and standard sacroiliac screw for the treatment of unilateral vertical sacral fractures; to provide reference for clinical applications.

METHODS

A finite element model of Tile type C pelvic ring injury (unilateral Denis type II fracture of the sacrum) was produced. The unilateral sacral fractures were fixed with lengthened sacroiliac screw and sacroiliac screw in six different types of models respectively. The translation and angle displacement of the superior surface of the sacrum (in standing position on both feet) were measured and compared.

RESULTS

The stability of one lengthened sacroiliac screw fixation in S1 or S2 segment is superior to that of one sacroiliac screw fixation in the same sacral segment. The stability of one lengthened sacroiliac screw fixation in S1 and S2 segments respectively is superior to that of one sacroiliac screw fixation in S1 and S2 segments respectively. The stability of one lengthened sacroiliac screw fixation in S1 and S2 segments respectively is superior to that of one lengthened sacroiliac screw fixation in S1 or S2 segment. The stability of one sacroiliac screw fixation in S1 and S2 segments respectively is markedly superior to that of one sacroiliac screw fixation in S1 or S2 segment. The vertical and rotational stability of lengthened sacroiliac screw fixation and sacroiliac screw fixation in S2 is superior to that of S1.

CONCLUSION

In a finite element model of type C pelvic ring disruption, S1 and S2 lengthened sacroiliac screws should be utilized for the fixation as regularly as possible and the most stable fixation is the combination of the lengthened sacroiliac screws of S1 and S2 segments. Even if lengthened sacroiliac screws cannot be systematically used due to specific conditions, one sacroiliac screw fixation in S1 and S2 segments respectively is recommended. No matter which kind of sacroiliac screw is used, if only one screw can be implanted, the fixation in S2 segment is more recommended than that in S1.

LEVEL OF EVIDENCE

Experimental study Level III.

Multiple target-specific molecular agents for detection and image analysis of breast cancer characteristics in mice

Breast cancer is a heterogenetic tumor at the cellular level with multiple factors and components. The inconsistent expression of molecular markers during disease progression reduces the accuracy of diagnosis and efficacy of target-specific therapy. Single target-specific imaging agents can only provide limited tumor information at one time point. In contrast, multiple target-specific imaging agents can increase the accuracy of diagnosis. The aim of this study was to demonstrate the ability of multi-agent imaging to discriminate such differences in single tumor. Mice bearing human cancer cell xenografts were tested to determine individual differences under optimal experimental conditions. Neovasculature agent (RGD peptide), tumor stromal agent (matrix metalloproteinase), and tumor cell markers (epidermal growth factor, Her-2, interleukin 11) imaging agents were labeled with reporters. 18F-Fluorodeoxyglucose was used to evaluate the tumor glucose status. Optical, X-ray, positron emission tomography, and computer tomography imaging modalities were used to determine tumor characteristics. Tumor size and imaging data demonstrated that individual differences exist under optimal experimental conditions. The target-specific agents used in the study bind to human breast cancer cell lines in vitro and xenografts in vivo. The pattern of binding corresponds to that of tumor markers. Multi-agent imaging had complementary effects in tumor detection. Multiple noninvasive imaging agents and modalities are complementary in the interrogation of unique biological information from each individual tumor. Such multi-agent approaches provide methods to study several disease components simultaneously. In addition, the imaging results provide information on disease status at the molecular level.

Intra-abdominal fibromatosis: differentiation from gastrointestinal stromal tumour based on biphasic contrast-enhanced CT findings

AIM

To identify the computed tomography (CT) criteria that differentiate intra-abdominal fibromatosis (IAF) from gastrointestinal stromal tumour (GIST).

MATERIALS AND METHODS

CT images of 34 pathologically proven cases of IAF (n = 15) and GIST (n = 19) were retrospectively reviewed. Location, contour, border, enhancement pattern, presence of necrosis, vessels, and air within the lesion were analysed. Long diameter (LD), short diameter (SD), LD/SD ratio, degree of enhancement, and lesion/aorta (L/A) CT attenuation ratio were measured and calculated. Significant CT criteria were identified using Fisher's exact test, grouped t-test, and receiver operating characteristic (ROC) curve. Sensitivity and specificity values were calculated when single or multiple CT criteria were used.

RESULTS

Extra-gastrointestinal location, ovoid or irregular contour, homogeneous enhancement, absence of intra-lesional necrosis, lower degree of enhancement, and L/A CT attenuation ratio differentiated IAF from GIST (p < 0.05). When any three of these eight criteria were combined, the sensitivity and specificity for diagnosing IAF were 100% (15 of 15) and 89.5% (17 of 19), respectively.

CONCLUSION

The following eight CT criteria are helpful to differentiate IAF from GIST: extra-gastrointestinal location, ovoid or irregular contour, homogeneous enhancement, absence of intra-lesional necrosis, a degree of enhancement of less than 40.5 HU in the arterial phase versus 46.5 HU in the portal venous phase, and an L/A CT attenuation ratio <0.315 in the arterial phase versus 0.525 in the portal phase.

Measurement of J/ψ azimuthal anisotropy in Au+Au collisions at sqrt[s(NN)]=200 GeV

The measurement of J/ψ azimuthal anisotropy is presented as a function of transverse momentum for different centralities in Au+Au collisions at sqrt[s(NN)]=200 GeV. The measured J/ψ elliptic flow is consistent with zero within errors for transverse momentum between 2 and 10 GeV/c. Our measurement suggests that J/ψ particles with relatively large transverse momenta are not dominantly produced by coalescence from thermalized charm quarks, when comparing to model calculations.

Correlation between the severity of periodontitis and coronary artery stenosis in a Chinese population

BACKGROUND

The aim of this study was to evaluate the relationship between the severity of periodontitis and the extent and degree of coronary artery stenosis in a Chinese population.

METHODS

Patients (n = 853) with coronary artery stenosis confirmed by coronary angiography were eligible to take part in the study. Only subjects that were ≥60 years old, had ≥50% stenosis in at least one coronary artery, and did not have diabetes or a history of smoking were included (n = 115). After periodontal examination, including bleeding index, probing depth calculus index, plaque index and periodontal attachment loss, four groups were defined based on the severity of periodontitis: no periodontitis/gingivitis (M0, n = 19); mild periodontitis (M1, n = 27); moderate periodontitis (M2, n = 31); and severe periodontitis (M3, n = 38). The extent and degree of coronary artery stenosis was obtained by calculating the Gensini score (GS).

RESULTS

The GS was significantly greater in the M3 group compared with the M0 group. Multiple linear regression analysis revealed that probing depth and plaque index were significantly correlated with the GS.

CONCLUSIONS

The extent and severity of coronary artery stenosis in Chinese patients ≥60 years old is positively correlated with the severity of periodontitis.