Hypothermic ischaemia of the liver: a re-perfusion phenomenon

BACKGROUND: The effects of hypothermic injury to the liver were investigated on an isolated perfusion circuit by comparing porcine livers with varying degrees of preservation injury. METHODS: A group of unstored livers (n = 5) were compared to livers stored in University of Wisconsin (UW) solution for 18 h (n = 5), and a group of livers stored in Hartmann's solution for 18 h (n = 5). RESULTS: We observed that the degree of platelet sequestration was directly related to the severity of the preservation injury. After 2 h of isolated liver perfusion, the perfusate platelet count fell from 148 +/- 14 x 10(9)/L to 84 +/- 13 x 10(9)/L for control livers. In comparison for livers stored in UW solution, the platelet count fell from 173 +/- 43 x 10(9)/L to 61 +/- 14 x 10(9)/L representing a 64.8% fall, while for those stored in Hartmann's solution, an even more profound fall from 152 +/- 36 x 10(9)/L to 19 +/- 9 x 10(9)/L (87.5% fall) was observed. The difference between the UW-stored and Hartmann's-stored livers was significant (P < 0.05). However, using this model, the degree of leukocyte sequestration did not differentiate the groups. Both histological and ultrastructural examination of liver biopsies taken immediately following revascularization demonstrated that for mild degrees of preservation injury following hypothermic storage, changes occur to the sinusoidal lining cells well before changes to the parenchymal elements. CONCLUSIONS: These findings substantiate the hypothesis that the primary injury associated with hypothermia involves the sinusoidal lining cells (non-parenchymal elements), that it is predominantly a reperfusion phenomenon and that efforts at improving preservation should therefore be targeted primarily at these cells and not the hepatocytes.     

Ceric-induced grafting of ethyl-acrylate onto sodium alginate

Sodium alginate was graft-copolymerized with ethyl acrylate using ceric ammonium nitrate as an initiator. In order to optimize the conditions for grafting, the concentrations of nitric acid, initiator and monomer together with temperature, time and amount of substrate were varied. The kinetic scheme of free radical graft copolymerization has been proposed and the equations relating the values of rate of polymerization, rate of graft copolymerization and rate of homopolymerization are also suggested. The experimental results agree very well with the proposed kinetic scheme.     

Monte Carlo and analytical calculation of proton pencil beams for computerized treatment plan optimization

Proton pencil beams in water, in a format suitable for treatment planning algorithms and covering the radiotherapy energy range (50-250 MeV), have been calculated using a modified version of the Monte Carlo code PTRAN. A simple analytical model has also been developed for calculating proton broad-beam dose distributions which is in excellent agreement with the Monte Carlo calculations. Radial dose distributions are also calculated analytically and narrow proton pencil-beam dose distributions derived. The physical approximations in the Monte Carlo code and in the analytical model together with their limitations are discussed. Examples showing the use of the calculated set of proton pencil beams as input to an existing photon treatment planning algorithm based on biological optimization are given for fully 3D scanned proton pencil beams; these include intensity modulated beams with range shift and scanning in the transversal plane.     

Interleukin-12 induces relapse in experimental allergic encephalomyelitis in the Lewis rat

Acute, monophasic experimental allergic encephalomyelitis (EAE) in the Lewis rat shows pathological similarities to the human disease multiple sclerosis (MS). Rats that recover from EAE are essentially resistant to disease reinduction, unlike MS in which relapses are frequently associated with common bacterial and viral infections. As macrophage-derived interleukin (IL)-12 is a critical component of innate resistance to bacterial infection and appears to directly activate encephalitogenic T cells in vivo, the ability of this cytokine to reinduce paralysis in EAE was examined. Paralytic disease was exacerbated by intraperitoneal IL-12 administration and could be reinduced up to 1 week after recovery from the primary clinical episode. Concomitant with worsening of initial clinical signs and relapse was an increase in the ratio of macrophages to T cells in brain stem perivascular cuffs and the expression of inducible nitric oxide synthase in cells with both macrophage and microglial morphology. These findings suggest that IL-12 may contribute to macrophage-mediated disease exacerbation and relapse in patients with MS.     

Plastic deformation of forearm

The unusual occurrence of plastic deformation in an adult is described.     

Alternative Granulation Technique: Melt Granulation

A melt granulation process has been investigated (1, 2) which efficiently agglomerates pharmaceutical powders for use in both immediate- and sustained-release solid dosage forms. The process utilizes materials that are effective as granulating fluids when they are in the molten state. Cooling of the agglomerated powders and the resultant solidification of the molten materials completes the granulation process. Both the molten agglomeration and cooling solidification were accomplished in a high shear Collette Gral mixer equipped with a jacketed bowl. Hence, the melt granulation process replaces the conventional granulation and drying operations which use water or alcohol solutions. The melt granulation process has been investigated using immediate- and sustained-release TAVIST® (clemastine fumarate USP) tablet formulations. The TAVIST granulations have been characterized by power consumption monitoring, measurement of the granulation particle size distribution, bulk and tapped density determinations, and loss-on-drying measurements. Scale-up of the melt granulation process for the sustained release TAVIST tablet formulation was judged successful based on a comparison of the hardness, friability, weight uniformity during compression, disintegration time, and dissolution rate data obtained at different manufacturing scales.     

Hypocalcemic-induced tetany that causes triceps and bilateral quadriceps tendon ruptures

Small-cell carcinoma (also known as oat-cell carcinoma) is a rare tumor that previously concerns the lung; small-cell carcinoma of the bladder is extremely rare (0.5% of all bladder malignancies). The Authors report here the case of a 78th years old man. Fourteen months before our observation he was submitted to a partial cystectomy for a small-cell carcinoma of the bladder cupola. There was no evidence of extra-vesical location at that moment and the patient was not submitted to any adjuvant therapy. At the moment of our observation the disease was very advanced and the patient died in a few time. The Authors discuss about the therapy of bladder small-cell carcinoma in the few cases described by the literature and about the survival of those patients. A radical surgical treatment in association with an adjuvant chemo- or radiotherapy appears as a better way to treat these patients. On account of this case the Authors agree with this choice and conclude that only a combined treatment can allow a better survival.     

Throughput and Delay in Random Wireless Networks With Restricted Mobility

Grossglauser and Tse (2001) introduced a mobile random network model where each node moves independently on a unit disk according to a stationary uniform distribution and showed that a throughput of Theta(1) is achievable. El Gamal, Mammen, Prabhakar, and Shah (2004) showed that the delay associated with this throughput scales as Theta(nlogn), when each node moves according to an independent random walk. In a later work, Diggavi, Grossglauser, and Tse (2002) considered a random network on a sphere with a restricted mobility model, where each node moves along a randomly chosen great circle on the unit sphere. They showed that even with this one-dimensional restriction on mobility, constant throughput scaling is achievable. Thus, this particular mobility restriction does not affect the throughput scaling. This raises the question whether this mobility restriction affects the delay scaling. This correspondence studies the delay scaling at Theta(1) throughput for a random network with restricted mobility. First, a variant of the scheme presented by Diggavi, Grossglauser, and Tse (2002) is presented and it is shown to achieve Theta(1) throughput using different (and perhaps simpler) techniques. The exact order of delay scaling for this scheme is determined, somewhat surprisingly, to be of Theta(nlogn), which is the same as that without the mobility restriction. Thus, this particular mobility restriction does not affect either the maximal throughput scaling or the corresponding delay scaling of the network. This happens because under this 1-D restriction, each node is in the proximity of every other node in essentially the same manner as without this restriction