Scanning Tissue Oxygen Needle Probe.

A new device designed to scan oxygen partial pressure along a line in a biological tissue is described in this paper. The probe is housed in a stainless-steel needle. As opposed to other devices for oxygen scanning in tissue, the new probe does not require mechanical translation of the needle in the tissue. The probe includes an active sensing area along the needle shaft that can be scanned optically by an internal optical fiber. This feature allows for repeated scans of tissue oxygen along a line without translating the needle with respect to the tissue, thus avoiding tissue damage associated with needle motion. First, we describe the design of the device including its sensing mechanism, mechanical design, optical configuration, and signal processing. We then move on to describe the results of the device characterization and testing. Finally, we conclude by discussing possible applications of the device in research and in clinical diagnoses and treatment monitoring.

Using executive control training to suppress amygdala reactivity to aversive information.

The ability to regulate emotions is essential for adaptive behavior. This ability is suggested to be mediated by the connectivity between prefrontal brain regions and the amygdala. Yet, it is still unknown whether the ability to regulate emotions can be trained by using a non-emotional procedure, such as the recruitment of executive control (EC). Participants who were trained using a high-frequent executive control (EC) task (80% incongruent trials) showed reduced amygdala reactivity and behavioral interference of aversive pictures. These effects were observed only following multiple-session training and not following one training session. In addition, they were not observed for participants exposed to low-frequent EC training (20% incongruent trials). Resting-state functional connectivity analysis revealed a marginally significant interaction between training group and change in the connectivity between the amygdala and the right inferior frontal gyrus (IFG). Amygdala-IFG connectivity was significantly increased following the training only in the high-frequent EC training group. These findings are the first to show that non-emotional training can induce changes in amygdala reactivity to aversive information and alter amygdala-prefrontal connectivity.

The safety and efficacy of live attenuated influenza vaccine in young children with asthma or prior wheezing.

In the European Union and Canada, an Ann Arbor strain live attenuated influenza vaccine (LAIV) is approved for use in children aged 2-17 years, including those with mild to moderate asthma or prior wheezing. The safety and efficacy of LAIV versus trivalent inactivated influenza vaccine (TIV) in children with asthma aged 6-17 years have been demonstrated. However, few data are available for children younger than 6 years of age with asthma or prior wheezing. Safety and efficacy data were collected for children aged 2-5 years with asthma or prior wheezing from two randomized, multinational trials of LAIV and TIV (N = 1,940). Wheezing, lower respiratory illness, and hospitalization were not significantly increased among children receiving LAIV compared with TIV. Increased upper respiratory symptoms and irritability were observed among LAIV recipients (p < 0.05). Relative efficacies were consistent with the results observed in the overall study populations, which demonstrated fewer cases of culture-confirmed influenza illness in LAIV compared with TIV recipients. Study results support the safety and efficacy of LAIV among children aged 2-17 years with mild to moderate asthma or a history of wheezing. Data regarding LAIV use are limited among individuals with severe asthma or active wheezing within the 7 days before vaccination.

Lentic Basommatophora molluscs and hygrophilous land snails as indicators of habitat and climate in the Early-Middle Pleistocene (0.78 Ma) at the site of Gesher Benot Ya'aqov (GBY), Israel.

The lentic Basommatophora molluscs and hygrophilous land snails of the Early-Middle Pleistocene site of Gesher Benot Ya'aqov (GBY), 0.78 Ma, crossed by the Matuyama-Brunhes chron boundary [MBB] were studied in order to reconstruct their specific habitats and possible reactions to climate change along the site sequence. Samples of equal sizes from 27 of the 46 layers along the 100 k.yr. time-span of the site were examined. About 2000 specimens of 21 lentic and hygrophilous species belonging to five families: Planorbidae (11), Lymnaeidae (6), Acroloxidae (2), Carychiidae (1) and Succineidae (1) were identified. The family with the largest biodiversity is the Planorbidae and of these, the most abundant species include Gyraulus piscinarum (937), Planorbarius corneus (210) and Radix labiata (160). The recent known zoogeographic origin of 81% of the species is Palaearctic and Holarctic. The MBB coincides with remarkable environmental changes reflected in molluscs, other faunal and floral elements and stable isotopes. The Planorbidae and Lymnaeidae reach greater abundance (90% and 80% of their assemblages, respectively) pre-MBB, while Acroloxidae, Succineidae and Carychiidae are more abundant (74%, 64% and 90%) post-MBB. Our data indicate that GBY molluscs show a two-phase pattern (shallow and deep lake) in each of the five defined cycles. Their numbers increase during the shallow water phases, thus the site climate changes from cold and humid in the oldest layers, to dry and cold up to the MBB and few succeeding layers. Between cycles 2 and 3, post-MBB, we see a short period of warm and humid climate that enables the influx of African and Asian elements. At the same time, cold climate species of Euro-Siberian and Palaearctic origin disappear. The succeeding layers indicate a cooler and humid climate. Finally, the sequence indicates deep water in the oldest layers and desiccation towards MBB and deeper water post-MBB.

Photoacoustic imaging endoscope.

We currently present a design concept for a photoacoustic imaging endoscope as well as some preliminary experimental results. The device is based on the generation of acoustic waves in tissue by short laser pulses and the sensing of these waves with a thin, optical Fabry-Pérot etalon. The entire device is designed to be mounted on the tip of a needle to deliver high-resolution photoacoustic imaging for minimally-invasive clinical applications such as diagnosing kidney disease and guiding laparoscopic surgery.

Nanoparticles for photoacoustic imaging.

Nanoparticles have been designed and applied as contrast enhancers in various optical imaging techniques, such as optical coherence tomography, fluorescence imaging, and optical reflectance microscopy. As an emerging hybrid imaging modality, photoacoustic imaging (PAI) has also benefited from the application of these nanoparticle-based contrast agents. We review this rapidly growing field and describe the applications of nanoparticles in PAI. Particular focus is given to nanoparticles whose absorption mechanism is based on surface plasmon resonance, including gold nanoshells, nanorods, and nanocages. Dye-embedded nanoparticles are also reviewed. Specifically, the design and application of each nanoparticle-based contrast agent in relation to the field of PAI are detailed.

Characterization of a broadband all-optical ultrasound transducer-from optical and acoustical properties to imaging.

A broadband all-optical ultrasound transducer has been designed, fabricated, and evaluated for high- frequency ultrasound imaging. The device consists of a 2-D gold nanostructure imprinted on top of a glass substrate, followed by a 3 microm PDMS layer and a 30 nm gold layer. A laser pulse at the resonance wavelength of the gold nanostructure is focused onto the surface for ultrasound generation, while the gold nanostructure, together with the 30 nm thick gold layer and the PDMS layer in between, forms an etalon for ultrasound detection, which uses a CW laser at a wavelength far from resonance as the probing beam. The center frequency of a pulse-echo signal recorded in the far field of the transducer is 40 MHz with -6 dB bandwidth of 57 MHz. The signal to noise ratio (SNR) from a 70 microm diameter transmit element combined with a 20 microm diameter receive element probing a near perfect reflector positioned 1.5 mm from the transducer surface is more than 10 dB and has the potential to be improved by at least another 40 dB. A high-frequency ultrasound array has been emulated using multiple measurements from the transducer while mechanically scanning an imaging target. Characterization of the device's optical and acoustical properties, as well as preliminary imaging results, strongly suggest that all-optical ultrasound transducers can be used to build high-frequency arrays for real-time high-resolution ultrasound imaging.

Long-term trends in hepatitis A incidence following the inclusion of Hepatitis A vaccine in the routine nationwide immunization program.

For many years hepatitis A was one of the most common vaccine preventable diseases in Israel. In 1999, Israel became the first country to introduce an inactivated hepatitis A vaccine into its national childhood vaccination program. The objectives of the present study were to study trends in disease incidence after the implementation of the new vaccination policy and to assess vaccination coverage among children and adults in Israel. We used the databases of the second largest HMO in Israel (1.7 million members) to identify patients who had evidence of hepatitis A in 1998 and 2007 and to collect information on all subjects who received at least one dose of hepatitis A vaccine during the study period. Hepatitis A vaccination coverage in children <5 years and 5-14 years of age increased from 9% and 15% in 1998 to 89% and 68% in 2007, respectively. During this period the annual incidence of hepatitis A dropped from 142.4 per to 7.6 per 100 000. The most prominent reduction in the age-specific annual incidence rates was calculated in children <5 years from 239.4 per 100 000 in 1998 to 2.2 per 100 000 in 2007 and from 310.3 per 100 000 to 3.0 per 100 000 in children aged 5-14 years. In endemic areas, vaccination of infants and children against hepatitis A can greatly reduce the total burden of the disease.

Community-acquired Pseudomonas aeruginosa urinary tract infections in children hospitalized in a tertiary center: relative frequency, risk factors, antimicrobial resistance and treatment.

BACKGROUND: The practice of antibiotic prophylaxis against recurrent urinary tract infection (UTI), with hospitalization reserved for severe or complicated cases, has led to changes in the nature and culprit uropathogens of community-acquired (CA), hospital-treated UTI. Characterization of subgroups that need special considerations is crucial. OBJECTIVES: To elucidate the trends and characteristics of CA Pseudomonas UTI in hospitalized children; define the antibiotic susceptibility; determine the appropriateness of the empiric antibiotics used; compare to other causes of UTI in this population; and thereby define predictors for Pseudomonas UTI. METHODS: A prospective clinical and laboratory study from 2001 through 2005. Children with P. aeruginosa UTI were characterized and compared with non-Pseudomonas UTI. RESULTS: Of 351 episodes of culture-proven CA UTI, 28 (8%) were caused by Pseudomonas, representing a 2.8-fold increase from our previous study. Pseudomonas UTI was more common in children > 5 years (p < 0.01), with urinary abnormalities (p < 0.01) and with previous antibiotic use in the previous month (p < 0.001). Pseudomonas UTI was often resistant to antibiotics usually recommended for empiric therapy; 25% was initially treated with inappropriate IV antibiotics (4.6% in the non-Pseudomonas group, p < 0.001) with 1.3 days longer IV antibiotics. On multivariate analysis, risk factors for Pseudomonas UTI were previous antibiotic therapy and underlying urinary pathology. CONCLUSIONS: Pseudomonas UTI seems to increase in CA, hospital-treated children and is often treated inappropriately according to current treatment protocols. Awareness of this trend and knowledge of the defined risk factors of Pseudomonas UTI might improve the empiric antibiotic therapy.

Outbreak of Mycobacterium mucogenicum bacteraemia due to contaminated water supply in a paediatric haematology-oncology department.

We describe an outbreak of bloodstream infections due to Mycobacterium mucogenicum involving five patients in a paediatric haematology-oncology ward over a six-month period. Specimens from faucets on the floor indicated that an automatic faucet was the probable source of infection and identity between strains was confirmed using molecular techniques. Levels of chlorine in the water were intermittently low and may have contributed towards bacterial growth. A review of infection control practices revealed that the exit sites of central venous catheters (CVCs) of children were not properly covered during bathing, which may have facilitated CVC colonisation. Replacing the contaminated faucets, optimal water chlorination and proper coverage of the CVC exit site using impermeable dressings terminated the outbreak. This investigation emphasises the three major factors that should be investigated in outbreaks due to a waterborne pathogen: source of the infection, water supply and infection control practices.

Optoacoustic generation of high frequency sound for 3-D ultrasonic imaging in medicine.

The most common form of optoacoustic generation is thermoelasticity. Thermoelastic transduction is easy to implement and can be very broadband. However, its major drawback has always been poor conversion efficiency when a metallic film is used as the transducer. We have investigated two alternate structures for high efficiency, one based on a thin polymer film and the other using a two-dimensional nanostructure.

The risk of hepatitis A infection among healthcare workers: a review of reported outbreaks and sero-epidemiologic studies.

All reports of hepatitis A (HA) outbreaks in healthcare settings published between 1975 and 2003 were studied to determine the background immunity or susceptibility of healthcare workers (HCWs) to HA. Twenty-six reports were found. The number of infected personnel ranged from one to 66 and, in most outbreaks, nurses accounted for the majority of personnel infected, reflecting high attack rates reaching 15-41%. In addition, we found 23 sero-epidemiological studies for HA among HCWs that had been performed in 13 different countries. Seroprevalence rates of HCWs with anti-HA antibody ranged between 4% among paramedical workers in Germany to 88% among hospital maintenance workers in Portugal. Effective infection control of HA outbreaks in hospitals demands early recognition, including awareness of atypical presentations of the infection, and strict adherence to universal infection control measures. Education programmes are of special importance for HCWs in neonatal, paediatric and intensive care units. The findings of the current study suggest that a pre-employment screening policy and administration of active vaccination to susceptible HCWs, particularly nurses, should be seriously considered in high-risk settings.

Difficulties in making the diagnosis of Hirschsprung disease in early infancy.

This study highlights the less common presentations of Hirschsprung disease (HD) and HD-associated enterocolitis (HAE) in neonates and infants. We present three infants whose diagnosis was delayed because of atypical presenting features, especially with failure to gain weight, decreased appetite, episodes of diarrhoea and vomiting and hypoalbuminaemia. The reported incidence of HAE ranges from 0 to 16.2%. To avoid complications of life-threatening HAE, primary care physicians require a high index of suspicion of the more unusual presentations of HD in neonates and infants.

In vitro bacterial adherence to ventriculoperitoneal shunts.

Bacterial adherence to medical devices has been recognized as an important initial step in the infectious process, but it has not been fully elucidated regarding ventriculoperitoneal (VP) shunts. The aim of the present study was to quantitatively determine the adherence in vitro of bacteria known to cause VP shunt infections and to identify factors affecting the process. Clinical isolates studied included Staphylococcus epidermidis, Staphylococcus aureus, Streptococcus pneumoniae, and Escherichia coli. Adherence was examined quantitatively per square centimeter, visualized by electron microscopy and related to slime production and hydrophobicity. Although all four strains adhered to VP shunts, there were marked differences, with S. epidermidis and S. aureus showing the highest adherence (67.0 x 10(3) and 15.2 x 10(3) bacteria/cm(2), respectively). Factors affecting adherence included incubation time and temperature, bacterial concentration, device material (lower for silicone than Teflon), slime production and hydrophobicity. These data might be helpful for devising novel strategies to reduce VP shunt infections.