Anti HLA class I monoclonal antibody effect on PKC kinetics in PHA activated human peripheral blood mononuclear and E+ cells

Cytoplasmic protein kinase C (PKC) has been studied in phytohemagglutinin (PHA) activated peripheral blood mononuclear cells (PBMC) and macrophage depleted E+ cell culture. Within 10' after contemporanous addition of PHA and anti HLA class I monoclonal antibody 01.65 (MoAb) PKC is depleted in both cell types. Enzyme activity recovers in the following hours however at 72 hours is at control values in E+ cultures while in PBMC cultures it is still depleted at 68% of the control. Anti HLA class I MoAb induced tritiated lymidine (3H-TdR) incorporation inhibition appears to be related to low levels of PKC activity.     

Some Medical Problems of Chronic Hemodialysis

Chronic intermittent hemodialysis may relieve some medical problems of terminal uremia (for example, azotemia, acidosis, hypertension, neuro-muscular disorders, bleeding, pericarditis) to such a degree that many patients are able to resume their normal activity. There remain, however, problems which are not readily changed by hemodialysis (anemia, peripheral neuropathy, pruritus, sexual impotence, renal osteodystrophy). These, together with medical problems possibly caused by hemodialysis (for example, osmotic disequilibrium, errors in dialysate composition, hepatitis, hemosiderosis, isoimmunization from blood transfusions, shunt problems and psychological problems of dependency upon the artificial kidney) represent a limitation of the present type of hemodialysis therapy.     

Aluminium polyphosphate complexes in the mycorrhizal basidiomyceteLaccaria bicolor: A27Al-nuclear magnetic resonance study

The techniques of ²⁷Al- and ³¹P-nuclear magnetic resonance (NMR) spectroscopy were used to investigate the interactions of aluminium with intracellular ligands within the mycelium of the ectomycorrhizal basidiomycete Laccaria bicolor (Maire) Orton (S238). The vegetative mycelium was grown on medium containing 0.5 mM AlCl₃ for 0.5 to 3 d. The ²⁷Al-NMR spectra showed that aluminium was rapidly taken up and accumulated into polyphosphate complexes in the vacuole. Comparison with Al-polyphosphate complexes obtained in vitro on model systems indicated that Al forms at least three mixed-solvation complexes with Pi and polyphosphates, that there is more than one complex present under any set of conditions, and that the equilibrium between these complexes shifts dramatically with Al concentration in the medium. The high phosphate concentrations in the growth medium favoured the accumulation of the Al-polyphosphate complexes. When mycelium containing Al-polyphosphate complexes was transferred to Al-free nutrient solution for 9 d, the Alpolyphosphate complexes were not remobilized. The sequestration of Al in the polyphosphate complexes could therefore make a significant contribution to the protection of mycorrhizal plants against aluminium toxicity.Abbreviations NMR nuclear magnetic resonance - PolyP polyphosphate(s) - PP₁ terminal phosphate of PolyP - PP₃ middle phosphate of PolyP We thank Prof. Daniel Canet (Laboratoire de Méthodologie RMN, University of Nancy I, Vandceuvre-lès-Nancy, France) for his constant encouragement and Christine Delaruelle for skilled technical assistance in growing the fungal cultures. This work was supported by a research grant from the Commission of the European Communities (STEP-CT90-0059, Role of Ectomycorrhiza in Stress Tolerance of Forest Trees) to F.M. and a travel grant from the Institut National de la Recherche Agronomique to I.K.; R.C. is a recipient of a Postdoctoral Fellowship from the Natural Sciences and Engineering Research Council of Canada.     

The role of the IGF-I receptor in the growth and transformation of mammalian cells

Abstract. Recent developments in the molecular biology of the insulin-like growth factor I (IGF-I) receptor have clarified its role in cellular growth and transformation. Although cells homozygous for a targeted disruption of the IGF-I receptor genes can grow in serum-supplemented medium, the IGF-I receptor is required for optimal growth, and is required equally in all phases of the cell cycle. The receptor plays an even more stringent role in cellular transformation and tumorigenicity, which seem to be dependent on its normal expression in several cell types. The expression of both the IGF-I receptor and its ligands is regulated by other growth factors (especially PDGF and EGF), by oncogenes (like SV40 T antigen and c-myb) and by tumour suppressor genes (like WT1 and RB). The picture emerging from these studies is that several transforming agents may exert their growth promoting effects through the direct or indirect activation of the IGF autocrine loop.     

Isolation and characterization of polymorphic microsatellite loci in white truffle (Tuber magnatum)

Tuber spp. are fungi that establish symbiosis with several trees and shrubs. Some of these fungal species produce edible ascomata, also known as truffles, which are highly appreciated for their taste and odour. We isolated and characterized eight polymorphic microsatellite loci from Tuber magnatum, the finest white truffle species, and assessed their variability in 370 individuals collected from all over the species range of distribution. Although two to 18 alleles per locus were found, no heterozygous individuals were observed. The availability of simple sequence repeat loci provides valuable tools for assessment of the genetic structure and population dynamics in this species.     

An assessment of red list data for the Pezizomycotina (Ascomycota): Umbria (Italy) as a test case

Abstract

A Red List of all 108 Pezizomycotina (Ascomycota) species recorded in Umbria Region (central Italy) is provided. According to the IUCN categories and criteria, 60.18% of the assessed species are classified as threatened, whereas 12.96% are Near Threatened (NT), 1.86% are Least Concerned (LC) and a noteworthy amount of 25% are Data Deficient (DD). As a consequence of the downlisting applied to the majority of the assessed taxa, according to the guidelines for application of IUCN red list criteria at Regional level, only 1.54% of the threatened species is Critically Endangered (CR), while 46.15% are Endangered (EN) and 52.31% are Vulnerable (VU). Given that the present work represents the first complete regional red list of Pezizomycotina in Italy, and that a national, as well as a European red list do not exist to date, it could be considered as a case study for other Italian Regions as well as for other European countries, aiming at the compilation of a national and European red list of this fungal group mostly overlooked in conservation strategies.     

Modulation of excitatory neurotransmission by neuronal/glial signalling molecules: interplay between purinergic and glutamatergic systems

Glutamate is the main excitatory neurotransmitter of the central nervous system (CNS), released both from neurons and glial cells. Acting via ionotropic (NMDA, AMPA, kainate) and metabotropic glutamate receptors, it is critically involved in essential regulatory functions. Disturbances of glutamatergic neurotransmission can be detected in cognitive and neurodegenerative disorders. This paper summarizes the present knowledge on the modulation of glutamate-mediated responses in the CNS. Emphasis will be put on NMDA receptor channels, which are essential executive and integrative elements of the glutamatergic system. This receptor is crucial for proper functioning of neuronal circuits; its hypofunction or overactivation can result in neuronal disturbances and neurotoxicity. Somewhat surprisingly, NMDA receptors are not widely targeted by pharmacotherapy in clinics; their robust activation or inhibition seems to be desirable only in exceptional cases. However, their fine-tuning might provide a promising manipulation to optimize the activity of the glutamatergic system and to restore proper CNS function. This orchestration utilizes several neuromodulators. Besides the classical ones such as dopamine, novel candidates emerged in the last two decades. The purinergic system is a promising possibility to optimize the activity of the glutamatergic system. It exerts not only direct and indirect influences on NMDA receptors but, by modulating glutamatergic transmission, also plays an important role in glia-neuron communication. These purinergic functions will be illustrated mostly by depicting the modulatory role of the purinergic system on glutamatergic transmission in the prefrontal cortex, a CNS area important for attention, memory and learning.     

Complexes of aluminium(III) with glucose-6-phosphate in aqueous solutions

The interaction of aluminium(III) with glucose-6-phosphate (GP: LH2) in aqueous solutions has been studied from pH 1 to pH 8, by pH-potentiometry and multinuclear (31P, 27Al, 13C) NMR spectroscopy. Various mononuclear species (MLH2, MLH, ML, ML2H, ML2 and MLH(-3)) and dinuclear complexes M2L2H-n (n=1-4) are formed in the system. NMR clearly indicates that GP is already bound to Al(III) at pH 1. The potentiometric speciation results are confirmed and completed by spectroscopic experiments. Many peaks are observed in the 31P NMR spectra suggesting the formation of isomeric species. An attempt to assign the signals to the corresponding complexes is made, allowing a discussion about their structure. Interestingly enough no metal ion-induced deprotonation and coordination of the alcoholic-OH functions have been observed.     

Genomic clustering of cyanogenic glucoside biosynthetic genes aids their identification in Lotus japonicus and suggests the repeated evolution of this chemical defence pathway

Cyanogenic glucosides are amino acid-derived defence compounds found in a large number of vascular plants. Their hydrolysis by specific β-glucosidases following tissue damage results in the release of hydrogen cyanide. The cyanogenesis deficient1 (cyd1) mutant of Lotus japonicus carries a partial deletion of the CYP79D3 gene, which encodes a cytochrome P450 enzyme that is responsible for the first step in cyanogenic glucoside biosynthesis. The genomic region surrounding CYP79D3 contains genes encoding the CYP736A2 protein and the UDP-glycosyltransferase UGT85K3. In combination with CYP79D3, these genes encode the enzymes that constitute the entire pathway for cyanogenic glucoside biosynthesis. The biosynthetic genes for cyanogenic glucoside biosynthesis are also co-localized in cassava (Manihot esculenta) and sorghum (Sorghum bicolor), but the three gene clusters show no other similarities. Although the individual enzymes encoded by the biosynthetic genes in these three plant species are related, they are not necessarily orthologous. The independent evolution of cyanogenic glucoside biosynthesis in several higher plant lineages by the repeated recruitment of members from similar gene families, such as the CYP79s, is a likely scenario.