Japanese encephalitis virus (JEV) and other arboviruses are demonstrating an emergence in the southern part of New Guinea Island. JE was previously unknown in this part of the world until 1995 when it was found in the Torres Strait, northern Australia. In this study 96 sera collected from residents of the Timika region of Irian Jaya were tested for antibodies to JEV and related arboviruses by epitope-specific blocking ELISA. Of the 9 sera deemed to be positive for JEV antibodies by ELISA, 5 were collected from persons indigenous to Timika, and who had not travelled to regions where JE is known to be active. This indicates that these individuals were infected with JEV in the Timika area and supports a recent report of a clinical case of JE in this region. Non-immune expatriates visiting or working in the Lowland areas of Irian Jaya and/or Papua New Guinea should consider immunization against JE. Precautions should always be taken to avoid being bitten by any mosquito both in the daytime and at night.

Antibodies, Viral↗

PubMedDate not supplied

Hemodynamic effects of microbubble echo contrast.

The dose-related hemodynamic effects of an active (bubble-rich) echo contrast agent were compared with those of a bubble-free contrast agent and saline solution to determine whether the microbubbles contained in the echo contrast agent are truly passive indicators in the circulation or whether they actively alter the hemodynamic state independent of the volume and osmotic loading associated with such injections. The study population consisted of 13 fully instrumented open-chest mongrel dogs. Four hundred ninety-two bolus injections were made of three different types: active contrast agent (Levovist, Schering AG, Berlin) (n = 333), saline solution (n = 112), and bubble-free contrast agent (n = 47). Levovist was administered in five dose ranges spanning 0.013 to 0.341 gm/kg and, like the saline solution, was administered in bolus volumes of 0.053 to 1.136 ml/kg. For each injection type, the percent change in hemodynamic parameters after administration of the bolus were calculated on the basis of the dose or volume of the injectate. Audio Doppler signal intensity was used to document the presence of bubbles in the injectate. Statistical significance was defined at the p = 0.05 level; clinical significance was defined as a greater than 15% change in a hemodynamic parameter. Statistically, but not clinically, significant changes were noted in almost all hemodynamic parameters regardless of injection type, and at all dose and volume ranges. Although statistically significant, injection of an active contrast agent in the human dose range resulted in a < 5% change in hemodynamic parameters. High doses of a contrast agent (active or bubble-free) increased the left atrial pressure and had associated changes in peripheral vascular hemodynamics because of the osmotic load. Clinically significant increases (> 15%) in pulmonary artery pressure and pulmonary vascular resistance were unique to the active contrast agent at high dose ranges. Standard doses of the active contrast agent changed the hemodynamics by less than 5% in healthy dogs. Transient clinically significant increases in pulmonary artery pressure and pulmonary vascular resistance are a unique side effect to high dose bolus injections of microbubble echo contrast agent.

Animals↗

PubMedDate not supplied

Harmonic imaging with Levovist.

Our purpose was to test the hypothesis that second harmonic imaging preferentially detects backscatter from microbubbles compared with tissue structural components. A prototype second harmonic scanner was used to image a flow channel in a tissue-mimicking rubber phantom (liver density). Video time-intensity curves were calculated from repeated bolus injections of microbubble echocardiographic contrast material under the same fluid dynamic conditions but with three different imaging modes: (1) fundamental imaging at 2.5 MHz (transmit and receive at 2.5 MHz), (2) fun damental imaging at 5.0 MHz (transmit and receive at 5.0 MHz), and (3) second harmonic imaging (transmit at 2.5 MHz and receive at 5.0 MHz). Each video time-intensity curve was calibrated-such that quantitative backscatter intensity was measured relative to the tissue phantom (0 dB). The peak increase in backscatter from the contrast material in the channel relative to the tissue phantom and the intensity in the channel before the contrast effect (the noise floor) was measured along with the area under the calibrated time-intensity curve relative to the phantom. When referenced to the noise floor in the flow channel, all imaging modes produced approximately 25 dB of enhancement. However, when referenced to the tissue phantom, second harmonic imaging produced a 22.3 +/- 1.8 dB peak enhancement, which was greater than either fundamental imaging at 2.5 MHz (15.5 +/- 0.8 dB; p < 0.001) or fundamental imaging at 5.0 MHz (15.3 +/- 1.5 dB; p < 0.001). The area under the time-intensity curves confirmed that harmonic imaging has approximately 7 dB of relative enhancement to the phantom compared with fundamental imaging at either frequency. Second harmonic imaging specifically enhances backscatter from microbubbles compared with a tissue-mimicking phantom. This specificity for microbubbles is due to a decrease in backscatter for the tissue phantom, rather than an increase in backscatter for the microbubbles. These data support the hypothesis that second harmonic imaging may be able to detect microbubbles in the tissue vascular space by preferentially decreasing the backscatter from tissue structural components.

Echocardiography↗

PubMedDate not supplied

Perimenstrual symptoms: time course of symptom intensity in relation to endocrinologically defined segments of the menstrual cycle.

This investigation assessed the syndromal nature of menstrual cycle changes in women who experience significant cyclicity of mood by exploring the time course of different symptoms in relation to endocrinologically defined segments of the menstrual cycle. Participants were accepted into the protocol on the basis of a prospectively documented history of perimenstrual mood change. The protocol included completion of the Daily Life Experiences Questionnaire and blood sampling during three menstrual cycles. The syndromal nature of menstrual cycle changes was explored by determining the types of symptoms which fluctuated in relation to five endocrinologically defined segments of the menstrual cycle, and the time course of the symptom changes. The results further document the temporal association between the luteal phase and the onset of perimenstrual symptoms and suggest that the syndromal nature of menstrual cycle-related changes may differ for women who experience different intensities of cyclical mood.

Adult↗

PubMedDate not supplied

Phototherapeutic keratectomy for Schnyder's central crystalline dystrophy.

Explore the source record for details and available documents.

Cornea↗

PubMedDate not supplied

Child care and our youngest children.

Studies of child development confirm that experiences with people mold an infant's mind and personality. Caregiving is, therefore, central to development, whether the caregiver is a parent, a grandmother, or a teacher in a child care center. This article uses data from new, national studies of families to examine the state of child care for infants and toddlers. The story it tells is complex, as the authors outline the overlapping impacts that diverse child care settings and home situations have on children. Early exposure to child care can foster children's learning and enhance their lives, or it can leave them at risk for troubled relationships. The outcome that results depends largely on the quality of the child care setting. Responsive caregivers who surround children with language, warmth, and chances to learn are the key to good outcomes. Other quality attributes (like training and staff-to-child ratios) matter because they foster positive caregiving. Diversity and variability are hallmarks of the American child care supply. Both "wonderful and woeful" care can be found in all types of child care but, overall, settings where quality is compromised are distressingly common. Children whose families are not buoyed by good incomes or government supports are the group most often exposed to poor-quality care. Given this balanced but troubling look at the status of child care for infants and toddlers, the authors conclude that there is a mismatch between the rhetoric of parental choice and the realities facing parents of young children in the United States. They call on communities, businesses, foundations, and government to play a larger role in helping parents secure good care for their infants and toddlers.

Child Care↗