Results from a horizon scan on risks associated with transplantation of human organs, tissues and cells: from donor to patient.

The successful transplantation of human materials such as organs, tissues and cells into patients does not only depend on the benefits, but also on the mitigation of risks. To gain insight into recent publications on risks associated with the process of transferring human materials from donor to recipient we performed a horizon scan by reviewing scientific literature and news websites of 2011 on this subject. We found there is ample information on how extended donor criteria, such as donor age, affect the survival rates of organs or patients. Interestingly, gender mismatch does not appear to be a major risk factor in organ rejection. Data on risks of donor tumor transmission was very scarce; however, risk categories for various tumor types have been suggested. In order to avoid rejection, a lot of research is directed towards engineering tissues from a patient's own tissues and cells. Some but not all of these developments have reached the clinic. Developments in the field of stem cell therapy are rapid. However, many hurdles are yet to be overcome before these cells can be applied on a large scale in the clinic. The processes leading to genetic abnormalities in cells differentiated from stem cells need to be identified in order to avoid transplantation of aberrant cells. New insights have been obtained on storage and preservation of human materials, a critical step for success of their clinical use. Likewise, quality management systems have been shown to improve the quality and safety of human materials used for transplantation.

Chronic meningitis by histoplasmosis: report of a child with acute myeloid leukemia

Meningitis is a common evolution in progressive disseminated histoplasmosis in children, and is asymptomatic in many cases. In leukemia, the impaired of the T cells function can predispose to the disseminated form. The attributed mortality rate in this case is 20 percent-40 percent and the relapse rate is as high as 50 percent; therefore, prolonged treatment may be emphasized. We have described a child with acute myeloid leukemia (AML), that developed skin lesions and asymptomatic chronic meningitis, with a good evolution after prolonged treatment with amphotericin B deoxycholate followed by fluconazole.

Chronic meningitis by histoplasmosis: report of a child with acute myeloid leukemia.

Meningitis is a common evolution in progressive disseminated histoplasmosis in children, and is asymptomatic in many cases. In leukemia, the impaired of the T cells function can predispose to the disseminated form. The attributed mortality rate in this case is 20%-40% and the relapse rate is as high as 50%; therefore, prolonged treatment may be emphasized. We have described a child with acute myeloid leukemia (AML), that developed skin lesions and asymptomatic chronic meningitis, with a good evolution after prolonged treatment with amphotericin B deoxycholate followed by fluconazole.

Analysis of nickel refinery dusts.

After characterization of bulk samples by inductively coupled plasma emission spectroscopic (ICP-ES) quantitative analysis and X-ray powder diffraction studies, single particle techniques using quantitative image analysis, scanning electron microscopy--energy dispersive analysis by X-ray, and finally laser beam ionization mass spectrometry analysis (LIMA) for surface analysis have been applied to historical nickel refinery dust samples from the nickel refining plant at Clydach in Wales. There were two historical samples of processed material from 1920 and 1929. These samples had a remarkably small particle size range, mean 3 microns and range, 0.75-24 microns. The most significant difference in elemental composition was the presence of 10% arsenic in the 1920 sample compared with 1% in the 1929 sample. The X-ray spectra revealed the presence of NiO in both. However, surprisingly, CuO was identified only in the 1929 sample. Of particular interest was the presence of a component, in the 1920 sample only, identified as the mineral orcelite, a copper-iron-nickel-arsenide-sulphide mineral, predominantly, Ni5-XAs2. Using the LIMA technique, it was found that in both samples, arsenic and arsenic derivative peaks are prominent, indicating the surface availability of arsenic compounds.

The role of the available sulphydryl group in liver butyryl-coenzyme A synthetase.

Butyryl-CoA synthetase from acetone-dried ox liver mitochondria can be activated up to 80% by low concentrations of iodoacetate with the concomitant modification of one available enzyme thiol group. The relative molecular mass of the carboxymethylated enzyme was unchanged, and there were no major changes in the complex kinetic properties of the enzyme. Extraction experiments on liver mitochondria indicate that in vivo the enzyme is linked to a mitochondrial membrane by a bond cleavable by disulphide bond reducing agents.

Ox liver butyryl-coenzyme A synthetase--a subunit enzyme?

Butyryl-CoA synthetase extracted from untreated or freeze-dried liver mitochondria consisted of two fractions of Mr 40,000 and 46,000 as determined by gel permeation chromatography, the higher value being confirmed by sedimentation equilibrium. A red pigment having the characteristic of haem was associated with the enzyme. This appeared to be an artifact of isolation. A number of active bands were obtained on polyacrylamide gel electrophoresis and isoelectric focusing, and on treatment with sodium dodecylsulphate or 6 M guanidine hydrochloride both dissociation and aggregation of the enzyme fractions occurred. As no evidence of protease contamination or proteolytic action could be detected, it is suggested that the active enzymes contain more than one polypeptide chain.

Associative properties of butyryl-coenzyme A synthetase from ox liver mitochondria.

Butyryl-coenzyme A synthetase (butyrate:CoA ligase (AMP-forming), EC 6.2.1.2) from an acetone-dried powder of ox liver mitochondria was found to have a molecular weight of approx. 40 000. The sedimentation equilibrium analysis suggested the presence in solution of higher molecular weight forms of the enzyme and these could also be obtained by extracting the enzyme from the mitochondrial powder in non-reducing conditions. The enzyme was inhibited by sulphydryl reagents, and was found to have at least one available thiol group/molecule. The relationship between enzymic activity and concentration was non-linear, and suggested that an inactive monomer-active dimer equilibrium was present. The 5--6-fold activation by bovine serum albumin required the presence of free thiol groups in the albumin and involved association of albumin with the enzyme.

A product-inhibition study of the mechanism of mitochondrial octanoly-coenzyme A synthetase.

By a study of the product-inhibition kinetics of the octanoyl-CoA synthetase from ox liver mitochondria, evidence was obtained consistent with the hypothesis that the enzyme reacts by a Bi Uni Uni Bi Ping Pong type of mechanism in which the order of addition and evolution of substrates and products is CoA, octanoate, octanoyl-CoA, ATP, PP(i) and AMP. There is also evidence that more than one molecule of CoA can add to the enzyme and that it may act as an allosteric activator.