Pediatric liver transplantation

Liver transplantation, which once was an experimental procedure of no practical interest, has become the preferred treatment for infants and children dying of almost all non-neoplastic end-stage liver diseases. Liver replacement is being provided by many well-trained teams on all of the continents, as is evident from the program today - the first international symposium on pediatric liver transplantation. I have been honored in giving the first paper in the process of introducing the remarkable work of a gifted younger generation of physicians and surgeons

Toxoplasma gondii infection in workers occupationally exposed to unwashed raw fruits and vegetables: a case control seroprevalence study

<p>Abstract</p> <p>Background</p> <p>Through a case control seroprevalence study, we sought to determine the association of <it>Toxoplasma gondii </it>infection with occupational exposure to unwashed raw fruits and vegetables.</p> <p>Methods</p> <p>Subjects, numbering 200, who worked growing or selling fruits and vegetables, and 400 control subjects matched by age, gender, and residence were examined by enzyme immunoassays for the presence of anti-<it>Toxoplasma </it>IgG and IgM antibodies. Socio-demographic, clinical, and behavioral characteristics from the study subjects were obtained.</p> <p>Results</p> <p>Of the 200 fruit and vegetable workers, 15 (7.5%) of whom, and 31 (7.8%) of the 400 controls were positive for anti-<it>Toxoplasma </it>IgG antibodies (<it>P </it>= 0.96). Anti-<it>Toxoplasma </it>IgM antibodies were found in 2 (1%) of the fruit workers and in 11 (2.8%) of the control subjects (<it>P </it>= 0.23). Seroprevalence of <it>Toxoplasma </it>antibodies increased with age (<it>P </it>= 0.0004). In addition, seropositivity to <it>Toxoplasma </it>was associated with ill status (<it>P </it>= 0.04), chronic tonsillitis (<it>P </it>= 0.03), and reflex impairment (<it>P </it>= 0.03). Multivariate analysis showed that <it>Toxoplasma </it>infection was associated with consumption of raw meat (OR = 5.77; 95% CI: 1.15-28.79; <it>P </it>= 0.03), unwashed raw fruits (OR = 2.50; 95% CI: 1.11-5.63; <it>P </it>= 0.02), and living in a house with soil floors (OR = 3.10; 95% CI: 1.22-7.88; <it>P </it>= 0.01), whereas <it>Toxoplasma </it>infection was negatively associated with traveling abroad (OR = 0.28; 95% CI: 0.12-0.67; <it>P </it>= 0.005).</p> <p>Conclusions</p> <p>This is the first report of seroprevalence and contributing factors for <it>Toxoplasma </it>infection in workers occupationally exposed to unwashed raw fruits and vegetables, and the results may help in the design of optimal preventive measures against <it>Toxoplasma </it>infection especially in female workers at reproductive age.</p

The dynamics of internal working surfaces in MHD jets

The dynamical effects of magnetic fields in models of radiative, Herbig-Haro (HH) jets have been studied in a number of papers. For example, magnetized, radiative jets from variable sources have been studied with axisymmetric and 3D numerical simulations. In this paper, we present an analytic model describing the effect of a toroidal magnetic field on the internal working surfaces that result from a variability in the ejection velocity. We find that for parameters appropriate for HH jets the forces associated with the magnetic field dominate over the gas pressure force within the working surfaces. Depending on the ram pressure radial cross section of the jet, the magnetic field can produce a strong axial pinch, or, alternatively, a broadening of the internal working surfaces. We check the validity of the analytic model with axisymmetric numerical simulations of variable, magnetized jets.Comment: 14 pages, 4 figures. ApJ in pres

New Variable Jet Models for HH 34

We consider newly derived proper motions of the HH 34 jet to reconstruct the evolution of this outflow. We first extrapolate ballistic trajectories for the knots (starting from their present-day positions and velocities) and find that at ~1000 yr in the future most of them will merge to form a larger-mass structure. This mass structure will be formed close to the present-day position of the HH 34S bow shock. We then carry out a fit to the ejection velocity versus time reconstructed from the observed proper motions (assuming that the past motion of the knots was ballistic) and use this fit to compute axisymmetric jet simulations. We find that the intensity maps predicted from these simulations do indeed match reasonably well the [S II] structure of HH 34 observed in Hubble Space Telescope images