Mechanism of action of antidysrhythmic drugs on ventricular conduction as studied with intramural electrodes

Using the Dürrer electrode needle to record the intramural electrogram and a standard peripheral electrocardiogram (ECG) lead as reference, the authors studied the action of 9 different drugs in the conduction system of dogs. The authors concluded that diphenylhydantoin and lignocaine would be useful in dysrhythmias related to increased excitability and perhaps increased automatism. Ajmaline and quinidine may be some of some interest in dysrhythmias due to conduction disturbances; and, finally, ajmaline, diphenylhydantoin, di-isopyramide and quinidine may be useful in dysrhythmias due to focal re-entry.

A fast way to track functional OmpF reconstitution in liposomes: Escherichia coli total lipid extract

A major requirement to perform structural studies with membrane proteins is to define efficient reconstitution protocols that ensure a high incorporation degree and protein directionality and topology that mimics its in vivo conditions. For this kind of studies, protein reconstitution in membrane systems via a detergent-mediated pathway is usually successfully adopted because detergents are generally used in the initial isolation and purification of membrane proteins. This study reports OmpF reconstitution in preformed Escherichia coli liposomes followed by detection of its insertion by analyzing modifications on membrane structure by two different techniques: steady-state fluorescence anisotropy and dynamic light scattering. Another important issue is protein directionality. For OmpF, it is known that interaction with polyamines promotes channel blockage. In this work, the spermine-OmpF interaction was evaluated using surface plasmon resonance, and protein directionality was confirmed.

Quality of antenatal care as a risk factor for early onset neonatal infections in Rio de Janeiro, Brazil

BACKGROUND

Neonatal infection is a serious public health problem. The aim of this study was to assess the influence of the antenatal care on the risk of early-onset neonatal healthcare associated infection in two Brazilian maternities.

METHODS

Cohort study - Newborns admitted at two public neonatal intensive care units from 2008 to 2009 were included in the study. Data on antenatal and perinatal variables were collected from maternal prenatal cards and medical charts. Newborns were actively surveyed for early-onset neonatal healthcare associated infection, defined as a neonatal infection diagnosed within 48h after birth. Multiple logistic regression was used to assess variables independently associated with early-onset neonatal healthcare associated infection.

RESULTS

561 neonate-mother pairs were included in the study. Early-onset neonatal healthcare associated infection was diagnosed in 283 neonates (51%), an incidence rate of 43.5/1000 live births. Neonates whose mothers had less then six antenatal visits were under risk significantly higher for early-onset neonatal healthcare associated infection (OR=1.69, 95% CI=1.11-2.57), after adjusting for birth weight, membranes ruptured for >18h, maternal complications during delivery, maternal infection at admission, and hospital where patients received care.

CONCLUSIONS

The risk of neonatal early-onset neonatal healthcare associated infection was significantly associated with insufficient number of antenatal care visits. Further studies assessing the quality of antenatal care and targeting its improvement are warranted.

Amperometric glucose biosensor based on layer-by-layer films of microperoxidase-11 and liposome-encapsulated glucose oxidase

An important step in several bioanalytical applications is the immobilization of biomolecules. Accordingly, this procedure must be carefully chosen to preserve their biological structure and fully explore their properties. For this purpose, we combined the versatility of the layer-by-layer (LbL) method for the immobilization of biomolecules with the protective behavior of liposome-encapsulated systems to fabricate a novel amperometric glucose biosensor. To obtain the biosensing unit, an LbL film of the H2O2 catalyst polypeptide microperoxidase-11 (MP-11) was assembled onto an indium-tin oxide (ITO) electrode followed by the deposition of a liposome-encapsulated glucose oxidase (GOx) layer. The biosensor response toward glucose detection showed a sensitivity of 0.91±0.09 (μA/cm2)/mM and a limit of detection (LOD) of 8.6±1.1 μM, demonstrating an improved performance compared to similar biosensors with a single phospholipid-liposome or even containing a non-encapsulated GOx layer. Finally, glucose detection was also performed in a zero-lactose milk sample to demonstrate the potential of the biosensor for food analysis.

Abstract OT2-6-13: A randomized phase 2 study of the triplet combination of ridaforolimus (RIDA), dalotuzumab (DALO) and exemestane (EX) compared to the ridaforolimus, exemestane doublet in high proliferation, estrogen receptor positive (ER+) advanced breast cancer

Background: The clinical benefit of combination of mTOR inhibition and anti-hormonal therapy has been previously established and represents a new standard of care for patients with hormone receptor positive (HR+) advanced breast cancer (ABC). Preclinical evaluation of the mTOR pathway demonstrates that dual inhibition of IGFR and mTOR may be additive or synergistic and abrogates the feedback activation of AKT due to rapamycin analog mTOR inhibitors. A completed phase 1 study of the combination of the mTOR inhibitor, RIDA and the anti-IGFR antibody, DALO demonstrated preliminary signals of anti-tumor activity. This was further evaluated in a recently completed phase 2 study of RIDA-DALO compared to exemestane in ER+ ABC. Final safety and efficacy results from that phase 2 study will be reported at this meeting (see Baselga et al). Building upon the clinical synergies of mTOR and EX as well as the biologic relationship of the mTOR and IGFR pathways, a clinical study has been initiated to evaluate the triplet combination of RIDA-DALO-EX compared to RIDA-EX. Methods: This is a multicenter, international, randomized phase 2 study of the triplet combination of RIDA (10 mg by mouth daily for 5 out of every 7 days), DALO (10 mg/kg IV weekly), and EX (25 mg QD) compared to RIDA (30 mg by mouth daily for 5 out of every 7 days) and EX (25 mg QD) in high KI67 (≥15%) expressing ER+, ABC. Approximately 84 patients will be randomized 1:1 to either triplet or doublet therapy. Key eligibility criteria include: HR+ and HER-2 negative measurable ABC, prior therapy with a non-steroidal aromatase inhibitor, and KI67 labeling index ≥15%. The primary endpoint of the study is progression free survival (PFS). Key secondary endpoints include evaluation of percent (%) reduction from baseline in the sum of imaging measurements (target lesion diameters or volumes) at 16 weeks between the two arms, and overall response rates. The sample size is event driven with a target of 38 PFS events, which provides approximately 80% power, at 1-sided alpha of 0.1, to detect a HR of 0.5, corresponding to an approximate 100% improvement in median PFS, from 10.6 to 21.2 months. Safety parameters or adverse experiences of special interest include hyperglycemia, stomatitis, mucosal inflammation, pneumonitis and hearing loss. Accrual has been completed with results expected in May 2014.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr OT2-6-13.

Use of skin and blubber tissues of small cetaceans to assess the trace element content of internal organs

In order to evaluate the use of biopsy samples as non-destructive tool for assessing trace element concentrations in small cetaceans, the concentrations of 14 trace elements were determined in skin, blubber, liver and kidneys of four species of small cetaceans (i.e. common dolphin Delphinus delphis, harbour porpoise Phocoena phocoena, bottlenose dolphin Tursiops truncatus and striped dolphin Stenella coeruleolba), stranded and/or by-caught along the NE Atlantic Ocean coast between 2001 and 2008. Only Cu, Fe, Hg, Mn, Ni and Zn were above the detection limit of the instruments and showed recoveries satisfactory enough to be interpreted. Among these trace elements, Hg was the only one showing a significant correlation between concentrations in and those in liver and kidneys. In consequence skin and blubber can only be used as non-invasive monitoring tissues to investigate Hg bioaccumulation in internal tissues for cetacean populations.

The importance of particle characterization in stormwater runoff

Treatment units for stormwater management are being routinely required for new construction and upgrading of older facilities. This paper shows how particle size distribution affects the removal of sedimentation units and how erroneous results are often obtained if one uses simple overall removal efficiency or if the particle size distribution is not considered. Two full-scale devices are used for demonstration. A hydrodynamic device, which generally have low, overall suspended solids removal efficiency, is used for the first case, and it is shown that it actually removes large particles very well but has virtually no removal of small particles. The second case is for a dry detention basin. It is shown that the removal rates are generally in accord with sedimentation theory, removing larger and medium size particles well. Using particle size distribution in evaluating treatment unit performance is a more accurate and precise way of determining the actual performance.

Size fractionation of metals present in highway runoff: beyond the six commonly reported species

Highway runoff is an important non-point source of pollutants, especially metals. This study reports monitoring results from 17 storm events at three highway sites for six commonly sampled metals: cadmium, chromium, copper, lead, nickel, and zinc. The study also reports the results of eight additional metals: aluminum, arsenic, cobalt, iron, manganese, selenium, strontium, and vanadium. Soluble phase, defined as passing a 0.45 microm filter, and particulate phase concentrations on four size fractions from 0.45 to larger than 100 microm are reported. The greatest metal masses were typically observed in the 8 to 20 microm fraction. The size distribution shows that sedimentation as a treatment process typically found in stormwater management can remove only 65% of the mass of most particulate phase metal species. Additional processes, such as coagulation or filtration, are needed to obtain greater removal rates. The results indicate the need to study particle size distribution (PSD) in order to better select treatment alternatives or assess environmental impacts.

Comparative study of the antioxidant capacity and polyphenol content of Douro wines by chemical and electrochemical methods

A comparative study of the antioxidant capacity and polyphenols content of Douro wines by chemical (ABTS and Folin-Ciocalteau) and electrochemical methods (cyclic voltammetry and differential pulse voltammetry) was performed. A non-linear correlation between cyclic voltammetric results and ABTS or Folin-Ciocalteau data was obtained if all types of wines (white, muscatel, ruby, tawny and red wines) are grouped together in the same correlation plot. In contrast, a very good linear correlation was observed between the electrochemical antioxidant capacity determined by differential pulse voltammetry and the radical scavenging activity of ABTS. It was also found that the antioxidant capacity of wines evaluated by the electrochemical methods (expressed as gallic acid equivalents) depend on background electrolyte of the gallic acid standards, type of electrochemical signal (current or charge) and electrochemical technique.

Measures of physical functioning after hip fracture: construct validity and responsiveness of performance-based and self-reported measures

OBJECTIVES

this study aimed to investigate the construct validity and responsiveness of performance-based and self-reported measures of strength, mobility and balance after hip fracture.

DESIGN

secondary analysis of clinical trial data.

SUBJECTS

a total of 148 older people undergoing hip fracture rehabilitation.

METHODS

correlation coefficients assessed construct validity. Internal responsiveness was assessed by calculating effect sizes (ES) I and II. Area under the receiver operating characteristic curve (AUC) assessed external responsiveness with change in EuroQol as the reference.

RESULTS

correlations between performance-based and self-reported measures were small to medium (strength r = 0.17, mobility r = 0.45 and balance r = 0.37). The most responsive performance-based measures included walking speed (ESI 1.7, ESII 1.2), Physical Performance and Mobility Examination (ESI 1.3, ESII 1.0) and chair-rise test (ESI 1.1, ESII 0.8). Self-reported mobility (ESI 0.8, ESII 0.6) and strength (ESI 0.8, ESII 0.6) were more responsive than self-reported balance (ESI 0.3, ESII 0.2). External responsiveness (AUC) was greatest for walking speed (0.72) and lowest for the measures of body sway (0.53).

CONCLUSION

self-reported and performance-based indices appear to assess different constructs and may provide complementary information about physical functioning in people after hip fracture. Measures of strength and mobility showed greater ability to detect change than measures of balance.