Formation of 20-oxoleukotriene B4 by an alcohol dehydrogenase isolated from human neutrophils

When 20-hydroxyleukotriene B4 (20-OH-LTB4) is incubated at pH 10.5 in the presence of NAD+ with an alcohol dehydrogenase isolated from human neutrophils, a polar product is formed as detected on reverse-phase high-performance liquid chromatography (RP-HPLC). The product is identified as 20-oxo-LTB4 (20-CHO-LTB4) on the basis of its co-elution with the authentic compound on HPLC, ultraviolet spectrometry and gas chromatography-mass spectrometry. The 20-CHO-LTB4-forming activity requires NAD+, but NADP+ scarcely replaces NAD+. The apparent Km for 20-OH-LTB4 is 83 microM and the Vmax is 2.04 mumol/min per mg of protein. The activity is inhibited by omega-hydroxy fatty acids such as 12-hydroxylauric acid, 16-hydroxypalmitic acid and 12(S), 20-dihydroxyeicosatetraenoic acid, but not by 4-methylpyrazole. At pH 7.0 with NADH, the purified dehydrogenase catalyzes the reverse reaction, the reduction of 20-CHO-LTB4 to 20-OH-LTB4.     

Effects of hypoxia and fatty acids on the distribution of metabolites in rat heart

The effects of exogenous fatty acids and hypoxia on cardiac energy metabolism were studied by measuring mitochondrial and cytosolic adenine nucleotides as well as CoA and carnitine esters using a tissue fractionation technique in non-aqueous solvents. During normoxia, the administration of 0.5 mM palmitate caused a considerable increase in acyl-CoA and acylcarnitine, particularly in mitochondria. High-energy phosphates, however, were only slightly altered. A 90 min low-flow hypoxia caused a dramatic increase in mitochondrial acyl esters. The mitochondrial ATP content decreased significantly, while the cytosolic concentration was only slightly diminished, suggesting an inhibition of mitochondrial adenine nucleotide translocation by long-chain acyl-CoA. Addition of palmitate during hypoxia amplified hypoxic damage and reduced adenine nucleotides in both compartments considerably, while fatty acid metabolites were only slightly affected. In presence of an inhibitor of fatty acid oxidation (BM 42.304), the fatty-acid-induced acceleration of cardiac injury was prevented. Since BM 42.304 decreased mitochondrial acylcarnitine and increased the cytosolic concentration significantly, BM 42.304 was presumed to inhibit mitochondrial acylcarnitine translocase. However, a causal relationship between lipid metabolites and ischemic damage seemed unlikely.     

A mutation in apolipoprotein A-I in the Iowa type of familial amyloidotic polyneuropathy

Immunoblotting of isoelectric focusing gels of plasma and direct genomic DNA sequencing have been used to characterize a mutation in apolipoprotein A-I associated with the familial amyloidotic polyneuropathy originally described by Van Allen in an Iowa kindred. An arginine for glycine substitution in apolipoprotein A-I identified in the proband's amyloid fibrils was determined to be the result of a mutation of guanine to cytosine in the apolipoprotein A-I gene at the position corresponding to the first base of codon 26. Direct sequencing of genomic DNA of three affected individuals who died in the 1960s confirmed the inheritance of the disorder. Immunoblot analysis detected the variant apolipoprotein A-I in the proband's plasma and in several at-risk members of the kindred. In addition, allele-specific amplification by the polymerase chain reaction was used to detect carriers of the variant gene.     

The HL-60 model for the interaction of human macrophages with the Legionnaires' disease bacterium

The facultative intracellular pathogen, Legionella pneumophila, multiplies within and kills human monocytes and alveolar macrophages. We show that L. pneumophila strain Philadelphia-1 infects, multiplies within and kills the promyelocyte HL-60 cell line after its differentiation into macrophage-like cells. The characteristics of the interaction between L. pneumophila and differentiated HL-60 cells closely resemble those between L. pneumophila and human peripheral blood monocytes. With both cell types, C receptors and serum C mediate attachment of L. pneumophila, which are taken up by coiling phagocytosis. The replicative phagosome is lined with ribosomes; intracellular multiplication is iron-dependent; and replicating bacteria ultimately destroy the host cell. As in human monocytes, an avirulent mutant derivative of L. pneumophila Philadelphia-1, 25D, does not replicate in and is not cytopathic for differentiated HL-60 cells. Differentiated HL-60 cells therefore provide a convenient and faithful model for the study of L. pneumophila-mononuclear phagocyte interaction.     

Characterization of insulin receptors in primary cultures of quail (Coturnix coturnix japonica) oviduct cells. The level of insulin receptor is regulated by steroid and peptide hormones

1. We have characterized the insulin receptor in primary cultured quail oviduct cells and examined the hormonal regulation of its level. 2. We have also shown the recycling pathway of insulin receptors in the cultured cells using specific inhibitors (tunicamycin, chloroquine, monensin, and brefeldin A). 3. Our data suggest that glucocorticoids play important physiological roles in egg-white protein synthesis through increasing the number of insulin receptors and insulin through enhancing the transport of amino acids.     

Haemoglobin, serum albumin and transferrin variants of Bali (Banteng) cattle, Bos (Bibos) javanicus

1. Individual blood samples from 144 Bali (Banteng) cattle [Bos (Bibos) javanicus] in the Northern Territory of Australia and from 61 Bali cross cattle, were examined by zone electrophoresis to determine the variants of haemoglobin, serum albumin and transferrin that are present. 2. Of the common cattle haemoglobin variants (A and B) only variant B occurs in the Bali cattle samples. A second variant, designated CBali, occurs in Bali cattle either as the heterozygote (B CBali) or as the homozygote, the frequencies of occurrence indicating a two-allele system of inheritance without dominance. The CBali cross samples may exhibit the homozygous or heterozygous A variant. 3. The CBali variant has an electrophoretic mobility intermediate between those of the A and B variants at pH 8.6 and 9.1 but closer to B than to A (B greater than C greater than A). It appears to be similar in mobility to the C variants found in Indian Khillan (CKhillan) by Naik, Sukumaran and Sanghvi (Anim. Prodn, 1965 I, 275-277), and in Asian cattle by Oishi, Abe and Namikama (Immunogenet. Lett., 1968 5, 170-173) and Abe, Mogi, Oishi, Tanaka and Suzuki (Proc. XIIth Europ. Conf. Anim. Blood Groups Biochem. Polymorphisms 1972, pp. 225-228), but appreciably different from those in Kenyan and Rhodesian cattle (CRhodesia) found by Braend (Anim. Blood Grps Biochem. Genet., 1971 2, 15-21) and Carr (Rhod. J. agric. Res., 1964 3, 62-62A), respectively. It is also different in mobility from the C variant found by Winter, Mayr, Schleger, Dworak, Krutzler and Burger (Res. vet. Sci., 1984 36, 276-283) in the mithun.(ABSTRACT TRUNCATED AT 250 WORDS)     

Epidermodysplasia verruciformis associated human papillomaviruses present a subgenus-specific organization of the regulatory genome region.

The regulatory regions of the human papillomaviruses (HPVs) 9, 17, 20, and 36 were mapped, sequenced, and aligned. They revealed an arrangement of putative protein binding sites specific for the epidermodysplasia verruciformis associated HPVs. Three subgroups could be differentiated.     

Whiting migration in the Bristol Channel: a predator-prey relationship

The relationship between whiting, Merlangius merlangus (L.), and the common shrimp, Crangon crangon L., in the Bristol Channel and Severn Estuary was investigated. The whiting population was found to comprise 0-group juveniles which only remain in the region for about 10 months before moving offshore. While within the estuary, the distribution and abundance of the two species were found to be clearly related. It is hypothesized that the whiting depends on the common shrimp because it is the only abundant prey species in the winter. Both the whiting and shrimp populations were found to not follow any long-term trend in numbers. It is suggested that the whiting population is stable because it is constrained by shrimp abundance which is, in turn, limited by physical constraints. Similar predator-prey relationships may be common to many European estuaries.