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Background: Acute appendicitis is the most common abdominal condition necessitating urgent surgical intervention in the United States. The objective of this study was to determine if interval laparoscopic appendectomy after initial nonoperative treatment for late appendicitis presenting as an appendiceal mass is a safe alternative to immediate appendectomy. Methods: Thirty two consecutive patients (aged 16–74 years) during a 5-year period presented with appendiceal mass. Seventeen received initial nonsurgical treatment followed by interval laparoscopic appendectomy (aged 16–60 years; group 1). Fifteen underwent immediate appendectomy (aged 16–74 years; group 2). Results: All patients in the interval laparoscopic appendectomy group improved with initial therapy and underwent surgery an average of 4.9 months later. Although the operative time and the complication rate were similar between groups 1 and 2, the time to return to baseline activities was significantly less in group 1 after adjusting for age (p = 0.02 or less). Conclusions: Interval laparoscopic appendectomy is safe in patients with chronic appendicitis and allows for judicious diagnostic evaluation of the appendiceal mass and planned surgery under controlled conditions.

Elevated concentrations of eicosanoids have been reported in bronchoalveolar lavage fluid (BALF) and blood of infants with persistent pulmonary hypertension (PPHN), thereby indicating their potential role in its pathophysiology. Extracorporeal membrane oxygenation (ECMO) has improved the outcome in selected infants with PPHN. We hypothesized that ECMO, by alleviating lung injury, would be associated with decreased eicosanoid production and clinical improvement. Twenty-two newborns with PPHN treated with either ECMO or conventional means were studied. Concentrations of TxB2, 6-keto-PGF1 alpha, PGD2, PGE2, LTB4, and LTE4 were serially measured in BALF. Elevated concentrations of all eicosanoids measured were observed in all infants with PPHN at the initiation of ECMO. Eicosanoid concentrations decreased in all infants with a good clinical outcome after ECMO, but they remained elevated in those with a poor outcome. In patients with less severe PPHN, not requiring ECMO, lower concentrations of eicosanoids were observed at initiation of therapy. Eicosanoid levels increased or did not change over the course of conventional treatment. We conclude that eicosanoids are present in high concentrations in infants with PPHN. Iatrogenic factors, including oxygen and barotrauma, appear to correlate with their concentrations. Removal of these factors is associated with decreased production of mediators and clinical improvement.

Acute appendicitis is the most common abdominal condition necessitating urgent surgical intervention in the United States. The objective of this study was to determine if interval laparoscopic appendectomy after initial nonoperative treatment for late appendicitis presenting as an appendiceal mass is a safe alternative to immediate appendectomy.Thirty two consecutive patients (aged 16-74 years) during a 5-year period presented with appendiceal mass. Seventeen received initial nonsurgical treatment followed by interval laparoscopic appendectomy (aged 16-60 years; group 1). Fifteen underwent immediate appendectomy (aged 16-74 years; group 2).All patients in the interval laparoscopic appendectomy group improved with initial therapy and underwent surgery an average of 4.9 months later. Although the operative time and the complication rate were similar between groups 1 and 2, the time to return to baseline activities was significantly less in group 1 after adjusting for age (p = 0.02 or less).Interval laparoscopic appendectomy is safe in patients with chronic appendicitis and allows for judicious diagnostic evaluation of the appendiceal mass and planned surgery under controlled conditions.

The deformation of Io, the tidal dissipation rate, and its interior spatial distribution are investigated by means of numerical simulations based on (1) a three-layer model (with dissipation in the mantle) or (2) a four-layer model (with dissipation in the asthenosphere). The mathematical derivation of the models is outlined; the selection of the input-parameter values is explained; the results are presented in extensive graphs and contour maps; and the constraints imposed on the models by observational data on the hot-spot distribution, tidal deformation, and gravity field are discussed in detail. It is found that both dissipation mechanisms may play a role on Io: model (2) is better able to explain the concentration of hot spots near the equator, while the presence of a large hot spot near the south pole (if confirmed by observations) would favor model (1).

Long term venous access devices have become an important part of the standard care for children with malignant diseases requiring chemotherapy. A prospective nonrandomized study was conducted between January 1985 and January 1987 examining complications, child and parental acceptance and costs between totally implantable venous access devices (ports) and externally exiting catheters. Fifty ports were placed in 49 patients who had a median age of ten years; median implant time was 350 days. Forty-one catheters were placed in 39 patients who had a median age of eight years; median implant time was 365 days. Both devices provided equivalent venous access. Although catheters were initially less expensive, the cost for both devices was comparable by the six month point. Beyond this time, an increasing savings was realized when the port was used. Catheter device complications occurred 14 times compared with seven with ports (p less than 0.02). There were 15 infectious complications with catheters compared with seven with ports (p less than 0.01). Child and parental acceptance questionnaires indicated that the ports were easier to care for and more readily accepted in children older than 11 years than were catheters (p less than 0.001). Totally implanted reservoirs are effective alternatives to external catheters for venous access in children with cancer.

Results are reported from computations of tidal heating processes in a realistic three-layer Europa model featuring an elastic ice lithosphere, an underlying inviscid water layer, and an elastic silicate core. The volumic density of the outer two layers were 940 and 1000, respectively, while the Europan mean density was 3030 kg/cu m and the total depth of the water layers was 100 km. Calculations of various thermal distributions in the liquid layer, heated tidally by the core, indicate that a decoupled ice lithosphere would be distorted by 23 m at the sub-jovian point, which would correspond with a Love number of 0.26. The tidal heating scenario does not explain the observed recent cracking of Europa's surface, unless the satellite also recently had a significantly more eccentric orbit.

The importance of the thermal evolution of the earth and the moon for the dynamical history of the earth-moon system is investigated using a model of coupled thermal-dynamical evolution of this system, in which the sun's gravity is ignored and only the gravitational interaction of the earth-moon system is included, along with oceanic dissipation. Results suggest that most of the lunar angular momentum was received from the earth via solid tides within the first few 100 million years after the formation of the earth and the moon, indicating that oceanic dissipation plays a minor role. It is suggested that solid tides, rather than ocean tides, might be most important to the lunar-orbit evolution.