Saline is as effective as nitrogen scavengers for treatment of hyperammonemia.

Urea cycle enzyme deficiency (UCED) patients with hyperammonemia are treated with sodium benzoate (SB) and sodium phenylacetate (SPA) to induce alternative pathways of nitrogen excretion. The suggested guidelines supporting their use in the management of hyperammonemia are primarily based on non-analytic studies such as case reports and case series. Canine congenital portosystemic shunting (CPSS) is a naturally occurring model for hyperammonemia. Here, we performed cross-over, randomized, placebo-controlled studies in healthy dogs to assess safety and pharmacokinetics of SB and SPA (phase I). As follow-up safety and efficacy of SB was evaluated in CPSS-dogs with hyperammonemia (phase II). Pharmacokinetics of SB and SPA were comparable to those reported in humans. Treatment with SB and SPA was safe and both nitrogen scavengers were converted into their respective metabolites hippuric acid and phenylacetylglutamine or phenylacetylglycine, with a preference for phenylacetylglycine. In CPSS-dogs, treatment with SB resulted in the same effect on plasma ammonia as the control treatment (i.e. saline infusion) suggesting that the decrease is a result of volume expansion and/or forced diuresis rather than increased production of nitrogenous waste. Consequentially, treatment of hyperammonemia justifies additional/placebo-controlled trials in human medicine.

Impact of (chemo)radiotherapy on immune cell composition and function in cervical cancer patients.

New treatments based on combinations of standard therapeutic modalities and immunotherapy are of potential use, but require a profound understanding of immune modulatory properties of standard therapies. Here, the impact of standard (chemo)radiotherapy on the immune system of cervical cancer patients was evaluated. Thirty patients with cervical cancer were treated with external beam radiation therapy (EBRT), using conventional three-dimensional or intensity modulated radiation therapy without constraints for bone marrow sparing. Serial blood sampling for immunomonitoring was performed before, midway and at 3, 6 and 9 weeks after EBRT to analyze the composition of lymphocyte and myeloid-cell populations, the expression of co-stimulatory molecules, T-cell reactivity and antigen presenting cell (APC) function. Therapy significantly decreased the absolute numbers of circulating leukocytes and lymphocytes. Furthermore, the capacity of the remaining T cells to respond to antigenic or mitogenic stimulation was impaired. During treatment the frequency of both CD4+ and CD8+ T cells dropped and CD4+ T cells displayed an increased expression of programmed cell death-1 (PD-1). In vitro blocking of PD-1 successfully increased T-cell reactivity in all five samples isolated before radiotherapy but was less successful in restoring reactivity in samples isolated at later time points. Moreover, (chemo)radiotherapy was associated with an increase in both circulating monocytes and myeloid-derived suppressor cells (MDSCs) and an impaired capacity of APCs to stimulate allogeneic T cells. T-cell reactivity was slowly restored at 6-9 weeks after cessation of therapy. We conclude that conventional (chemo)radiotherapy profoundly suppresses the immune system in cervical cancer patients, and may restrict its combination with immunotherapy.

Blood outgrowth endothelial cells from cord blood and peripheral blood: angiogenesis-related characteristics in vitro.

BACKGROUND: Blood outgrowth endothelial cells (BOEC) are good candidates for vascular (re-) generating cell therapy. Although cord blood (CB) BOEC have been reported as more proliferative than peripheral blood (PB) BOEC, not much is known about their functional properties. OBJECTIVES: We have studied the following determinants in BOEC expanded from CB and PB: endothelial phenotype, in vitro adhesion, migration, proliferation, and angiogenic tube forming capacity. METHODS/RESULTS: Endothelial phenotype of BOEC was evaluated by fluorescence activated cell sorting (FACS) analysis and confirmed the presence of endothelial markers including CD31, CD105, CD144, CD146, KDR/VEGFR-2, Tie-2, and TNF-alpha-induced VCAM-1 and ICAM-1. Evaluation of cell proliferation revealed a higher basal proliferation of CB-BOEC, which increased after exposure to bFGF but not VEGF. The lower basal proliferation of PB-BOEC increased with VEGF or bFGF addition. Array analysis of angiogenic genes showed many comparable expressions in both BOEC, and a slightly more pronounced pro-angiogenic profile in CB-BOEC than PB-BOEC. Both BOEC were able to form tubular structures in a three-dimensional fibrin matrix. Tube formation in CB-BOEC was markedly induced by TNF-alpha only and inhibited by anti-urokinase antibodies. It was comparable to that induced by combined addition of TNF-alpha and VEGF or bFGF, while maximal tube formation in PB-BOEC required simultaneous exposure to TNF-alpha/VEGF or TNF-alpha/bFGF. CONCLUSIONS: The endothelial phenotype and characteristics for homing, adhesion, migration, inflammation, and angiogenic tube formation are almost equal for BOEC from CB and PB. A slightly more angiogenic phenotype favors CB-BOEC. However, addition of VEGF to PB-BOEC induces equal proliferation and tube formation.

Secondary carnitine deficiency.

For any given tissue the normal carnitine content is that which is necessary for an optimal rate of long-chain fatty acid oxidation. Tissues especially rich in carnitine are liver, muscle and heart. The endogenous rate of carnitine biosynthesis from lysine and methionine is not known to be influenced by fluctuations in the levels of the parent amino acids, as exemplified by hypermethioninaemic patients. Inadequate dietary supply of carnitine, leading to a deficiency, may occur in vegetarians and especially in subjects on total parenteral nutrition. Premature babies are especially at risk in this respect, and this has led to the addition of carnitine to solutions for intravenous alimentation. It has been suggested that carnitine plays an important role in the intramitochondrial regulations of coenzyme A homeostasis by expelling short-chain and medium-chain acyl groups from the mitochondrion in the form of acylcarnitines. These esters are preferentially excreted into the urine and thus result in a depletion of the body's carnitine stores. Important conditions in this respect are the inherited organic acidurias and disorders of fatty acid oxidation. Urinary acylcarnitines can be identified by indirect gas chromatographic or direct mass spectrometric methods. Patients on haemodialysis treatment will lose carnitine in the dialysis fluid, whereas excessive urinary losses of free and acetylated carnitine occur in the Fanconi syndrome. Secondary carnitine deficiency may be accompanied by a moderate degree of muscular dysfunction. Reassuringly, however, no signs of hepatic or cardiac involvement, as often seen in primary carnitine deficiency, have been observed.