Soft tissue infections of the abdominal wall in 14 children were classified as cellulitis (8), necrotizing fasciitis (5), or myositis/myonecrosis (1). These 3 categories were characterized by ...increasing anatomic depth of infection, clinical severity, and need for more radical surgical treatment. Ten of the 14 children were neonates. The most frequent associations were omphalitis (5), necrotizing enterocolitis (4), and urachal anomalies (3). The severest infections were usually polymicrobial and contained both aerobic and anaerobic bacteria. Important clinical findings in children with necrotizing fasciitis and myositis/myonecrosis were tachycardia, systemic toxicity, severe edema, and, in older children, pain out of proportion to the apparent degree of infection. None of the children had fever or crepitation of the wound. An ominous sign, indicative of the need for immediate, radical debridement was the appearance of a patch of dusky or gangrenous skin. There were two deaths associated with delayed diagnosis of necrotizing fasciitis. One child did not receive radical debridement, and the other received it too late to be of benefit. Although these infections are rare in children, their lethal potential and early diagnostic signs must be recognized.
We evaluated the pH of six hydrogen peroxide (H2O2) soft lens disinfection systems which had over-the-counter (OTC) H2O2 substituted for the manufacturer's recommended H2O2. Substitution of four ...brands of OTC H2O2 into the five two-step disinfection systems resulted in a pH after neutralization which ranged from 6.70 to 7.55 pH units. There was a small but statistically significant difference in the pH after neutralization when OTC H2O2 was substituted for the manufacturer's recommended H2O2. There was a significantly lower pH after neutralization when the same brands of OTC H2O2 were substituted for the manufacturer's recommended H2O2 in a one-step H2O2 disinfection system. The pH after neutralization for the manufacturer's recommended H2O2 was 6.50 pH units. The pH after neutralization for the OTC H2O2 ranged from 3.35 to 4.77 pH units. This range is below the ocular comfort range of 6.6 to 7.8 pH units. These findings, along with other possible differences between OTC H2O2 and the manufacturer's recommended H2O2, indicate that OTC H2O2 should never be substituted for the manufacturer's recommended H2O2 in any H2O2 soft lens disinfection system.
The transport of fine particulate organic matter (FPOM) in streams is an important process that links stream reaches, but until recently little was known about the distances traveled by fine ...particles in streams or the mechanisms governing their transport, deposition, and resuspension. Within the past decade, a number of studies have measured FPOM transport distances using either natural stream particles or a variety of artificial particles as FPOM surrogates. The purpose of our study was to compare estimates of FPOM transport distances in streams using: 1) radioactively labeled natural FPOM, and 2) corn pollen as an FPOM surrogate. We compared the particle types with simultaneous releases at 3 locations in Bloomington Creek, Idaho, and in a streamside flume in Pennsylvania. Mean transport distances in the stream and in the flume ranged from 49 to 637 m for corn pollen, compared with 23 to 1164 m for natural FPOM. Particle deposition velocities, which adjust for the effects of water depth and velocity on transport distance, had narrower ranges: 0.094 to 0.31 mm/s for pollen and 0.051 to 0.25 mm/s for natural FPOM. Pollen and FPOM transport distances were not significantly different at 2 of the stream sites, whereas corn pollen transport was significantly shorter at the 3rdstream site and significantly longer in the flume. We conclude that corn pollen, although not an exact mimic of natural particles, provides estimates of FPOM transport that are well within the limits of precision obtained with other methods. Corn pollen and other seston surrogates can serve as useful standard particles for comparing FPOM dynamics in streams with a variety of geomorphic and hydraulic characteristics.
Society Business Delcourt, Hazel R.; Sharitz, Rebecca R.; Cushing, C. E. ...
Bulletin of the Ecological Society of America,
12/1988, Letnik:
69, Številka:
4
Journal Article
PDF
