Hypoplasia of the optic nerve in association with porencephaly

Two cases of hypoplasia of the optic nerve associated with porencephaly are described. The clinicopathological correlation of the double ring sign is presented and the possible mechanism of optic nerve hypoplasia being a secondary degeneration is discussed.     

Testing the effectiveness of icons for supporting distributed team decision making under time pressure

There has been minimal experimentation testing the effectiveness of icons (or interface features in general) on distributed team decision making. To overcome this deficiency, an experiment tested the effectiveness of a "send" icon to remind team members to send information to their teammates, and a "receive" icon to tell them when they had received information, for a simulated, military task. As predicted, the "send" icon was effective in maintaining information flow, particularly when time pressure was high and simulated teammates sent less information, because it reduced memory burden and supported proactive behavior. The "receive" icon was only effective in supporting decision accuracy when time pressure was low. As time pressure increased, participants' with the "receive" icon increasingly used a strategy of making decisions before reading the most important information, completely counter to expectations. These results illustrate the subtle, sometimes surprising way task characteristics (e.g., time pressure) can affect participants' strategies and, thereby, ify the positive effect of displays on performance. The experiment also examined other task characteristics and working memory capacity, and showed how the lens model equation (LME) helped explain all effects on decision accuracy.     

Examining the effects of communication training and teamcomposition on the decision making of Patriot air defense teams

An experiment investigating the effect of communication training and three group composition variables was performed with Patriot air defense teams for two different types of aircraft identification tasks. It was predicted that communication training would significantly enhance communication quantity and quality and, in turn, team performance for both tasks. Although the training did sometimes improve team communication processes, it did not improve team performance. The variable that had the biggest positive effect on communication quality and team performance was the number of hours a team had worked together. This effect was only found, however, for the type of task for which Patriot teams routinely train. It did not transfer to the less frequent and more cognitively stressing task where there is conflicting information about unknown aircraft, as in the USS Vincennes tragedy     

Effect of size or age of goldfish and fathead minnows on use of pentachlorophenol as a reference toxicant

Acute bioassays of pentachlorophenol were conducted with fathead minnows and goldfish to determine the effect of testing different sized fish of the same age or testing different aged fish. With different sized goldfish the rate of mortality during the test was similar but the threshold lc₅₀ was higher for small fish. With different sized fathead minnows the rate of mortality during the test was significantly different but the threshold lc₅₀ was the same for large and small fish. With different aged fathead minnows the rate of mortality was different for 14-week-old fish and the same for 11-, 7-, and 4-week-old fish but there was no difference in threshold lc₅₀ due to age. Size selection of fatheads or goldfish within the ranges tested is unnecessary since differences are small. Since age of fatheads did not affect the 24-h, 96-h, or threshold lc₅₀'s, use of younger fish would allow smaller bioassay chambers or more fish per chamber.     

What are the possible causes of neonatal nephrocalcinosis?

The development of pulmonary arteriovenous fistulas after bidirectional cavopulmonary operations, such as the bidirectional Glenn shunt and Kawashima's procedure, has raised concern. Development of these fistulas, which are more frequent than initially thought, can represent a limiting factor in the late outcome of these patients and may even limit the indication for these types of surgery. Whether the fistulas can be reversed by transforming the surgical procedures has yet to be established. In the hope of avoiding this kind of complication, thought to be caused by the lack of passage of a hypothetical hepatic factor through the pulmonary circulation, we have developed an inverted type of bidirectional cavopulmonary connection in which the blood coming from the liver perfuses immediately both lungs. This is made possible by shunting via an intra-atrial tunnel the blood from the superior caval vein directly to the left atrium, and the blood from the inferior caval vein to the right branch of the pulmonary trunk (keeping its bifurcation intact). We describe findings in two patients undergoing successful surgery with this technique. Serial follow-up with contrast echocardiography did not show evidence of arteriovenous pulmonary fistulas. Despite our numbers being small, and the time of follow-up being limited, we believe that it is important to document these and similar cases.     

Randomized, double-blind comparison of hirulog versus heparin in patients receiving streptokinase and aspirin for acute myocardial infarction (HERO). Hirulog Early Reperfusion/Occlusion (HERO) Trial Investigators

BACKGROUND: Thrombolytic therapy improves survival after myocardial infarction through reperfusion of the infarct-related artery. Thrombin generated during thrombolytic administration may reduce the efficacy of thrombolysis. A direct thrombin inhibitor may improve early patency rates. METHODS AND RESULTS: Four hundred twelve patients presenting within 12 hours with ST-segment elevation were given aspirin and streptokinase and randomized in a double-blind manner to receive up to 60 hours of either heparin (5000 U bolus followed by 1000 to 1200 U/h), low-dose hirulog (0.125 mg/kg bolus followed by 0.25 mg x kg(-1) x h(-1) for 12 hours then 0.125 mg x kg(-1) x h(-1)), or high-dose hirulog (0.25 mg/kg bolus followed by 0.5 mg x kg(-1) x h(-1) for 12 hours then 0.25 mg x kg(-1) x h(-1)). The primary outcome was Thrombolysis In Myocardial Infarction trial (TIMI) grade 3 flow of the infarct-related artery at 90 to 120 minutes. TIMI 3 flow was 35% (95% CI, 28% to 44%) with heparin, 46% (95% CI, 38% to 55%) with low-dose hirulog, and 48% (95% CI, 40% to 57%) with high-dose hirulog (heparin versus hirulog, P=.023; heparin versus high-dose hirulog, P=.03). At 48 hours, reocclusion had occurred in 7% of heparin, 5% of low-dose hirulog, and 1% of high-dose hirulog patients (P=NS). By 35 days, death, cardiogenic shock, or reinfarction had occurred in 25 heparin (17.9%), 19 low-dose hirulog (14%), and 17 high-dose hirulog patients (12.5%) (P=NS). Two strokes occurred with heparin, none with low-dose hirulog, and two with high-dose hirulog. Major bleeding (40% from the groin site) occurred in 28% of heparin, 14% of low-dose hirulog, and 19% of high-dose hirulog patients (heparin versus low-dose hirulog, P<.01). CONCLUSIONS: Hirulog was more effective than heparin in producing early patency in patients treated with aspirin and streptokinase without increasing the risk of major bleeding. Direct thrombin inhibition may improve clinical outcome.     

Poverty,Race, and US Metropolitan Social and Economic Structure

This research evaluates the link between social and economic structural features of US urban areas and the poverty rates of black and white residents in 1990. Using a sample of 112 metropolitan areas (with poverty rates ranging from 9.4% to 45.4% for blacks, and 3.5% to 16.0% for whites) and multiple regression analysis, we find that metropolitan location in the Northeast lowers poverty rates of blacks and whites compared to metropolitan areas in other regions. Moreover, population growth, higher percent black, increased black high school graduation rates, the presence of immigrants, a high percentage of workers employed in manufacturing and relatively few in retailing, low black unemployment, and an older black population are related to lower black poverty rates. For whites, lower poverty rates are related to high racial residential segregation, increased white high school graduation rates, low white unemployment, a large black population, and a high percentage of workers employed in manufacturing and fewer employed in retail sales and professional services.     

Acute onset of dermatitis, hepatitis, and eosinophilia

A 48-year-old man presented to the emergency department complaining of fever, chills, myalgias, and diffuse abdominal discomfort of four days' duration. A nonpruritic rash had developed on his left palm, arms, legs, and buttocks on the fourth day. He had not had respiratory symptoms, nausea, vomiting, or diarrhea.     

What is the appropriate workup and treatment for an infant with an umbilical artery catheter-related thrombosis?

We investigated the effect of inhibition of a polyol pathway on the glucose-induced increase in transforming growth factor-beta (TGF-beta) production and activity of protein kinase C (PKC) in cultured human mesangial cells (MCs). The exposure of MCs to 33 mmol/l glucose resulted in an increase in TGFbeta production, measured by ELISA, compared with 5 mmol/l glucose. The glucose-induced increase in TGF-beta was prevented by concomitant incubation with epalrestat, an aldose reductase inhibitor (ARI), in a dose-dependent manner at a concentration of more than 10(-6) mol/l. Moreover, the glucose-induced enhancement of PKC activity in the membrane fraction of MCs was also abolished by epalrestat. The addition of epalrestat to MCs cultured with 5 mmol/l glucose showed no demonstrable effects on TGF-beta production and PKC activity. These results provide direct evidence for linkages between derangements in polyol pathway and glucose-induced overproduction of TGF-beta and enhancement of PKC activity in MCs. Accordingly, the effect of an ARI on these metabolic abnormalities in MCs may justify its clinical application for treatment of diabetic nephropathy.