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Drosophila has two pairs of Pax genes, ey/toy and eyg/toe, that play different functions during eye development. ey specifies eye fate, while eyg promotes cell proliferation. We have determined the molecular basis for the functional diversity of Eyg and Ey. Eyg and Ey act by distinct transcriptional mechanisms. They use different DNA-binding domains for target recognition. Most interestingly, Eyg acts exclusively as a repressor, whereas Ey is an activator. Several vertebrate Pax proteins are known to switch between activator and repressor activities, but none as repressors only. Eyg may be the first Pax protein as a dedicated repressor. Vertebrates produce a Pax6 isoform, Pax6-5a, differing from Pax6 in DNA-binding properties and functions and structurally similar to Eyg/Toe. We found that Pax6-5a acts as an activator like Ey, but has DNA-binding specificity like Eyg.

The teashirt (tsh) gene has dorso-ventral (DV) asymmetric functions in Drosophila eye development: promoting eye development in dorsal and suppressing eye development in ventral by Wingless mediated Homothorax (HTH) induction [Development 129 (2002) 4271]. We looked for DV spatial cues required by tsh for its asymmetric functions. The dorsal Iroquois-Complex (Iro-C) genes and Delta (Dl) are required and sufficient for the tsh dorsal functions. The ventral Serrate (Ser), but not fringe (fng) or Lobe (L), is required and sufficient for the tsh ventral function. We propose that DV asymmetric function of tsh represents a novel tier of DV pattern regulation, which takes place after the spatial expression patterns of early DV patterning genes are established in the eye.

One hundred children with suspected congenital and/or malformation and their parents who reported to SAT hospital, Medical College, Trivandrum, India formed the test group. Fifty children with no obvious anomalies or abnormalities and their parents formed the control group. The criteria for selection of the control was 1) the maternal age at delivery was below 30 years and 2) the parents belong to 1st or 2nd birth order. The chromosomal analysis was carried out in all the subjects using peripheral blood lymphocyte microculture to investigate for any constitutional chromosomal markers and quantitate the mutagen (bleomycin) sensitivity of the chromosomes. All the subjects were evaluated clinically and a complete family history was recorded. Chromosome anomalies were noted in 41 out of the one hundred children and in 4 out of the 200 parents of the test group. No constitutional aberrations were seen either in the parents or in the children of the control group. Bleomycin sensitivity study revealed a high b/c value in 35 children (24 hypersensitive and 11 sensitive) of the test group whereas in the control group the b/c values were low denoting hyposensitivity and very good DNA repair mechanism. This study reveals that the incidence of chromosome aberrations is higher when the age and birth order of parents are higher. A direct correlation was noted with parental order and b/c value. This was also true with the parental age and birth defects.

The prevalence of smoking has increased among young people aged 14 to 18 between 1993 and 1999, and most notably among girls within the same period. These observations illustrate the necessity for significant changes in mass media campaigns and education programmes related to the prevention of smoking among youth. The objective of this survey, initiated by the city of Besançon and the French National Mutual Insurance of Doubs, was to describe and analyse the knowledge and rationale of high school students on tobacco and their opinions in terms of prevention. Twelve public and private high schools in Besançon and Morteau (Doubs-France) participated in the survey; the group also represented a mix of general and professional schools. The questionnaire was filled out by 970 students selected at random. 96% of the students indicated cancer as being the main illness linked to tobacco and 94% stated that second-hand smoke constitutes a health risk. 61% admitted to seeking out the psychoactive effects of smoking. The students responses confirm that the types of messages relayed in a smoking prevention campaign which have an impact on them are: evoking fear of death (74%) and the use of humor (16%). One-third of high school students find that it is unacceptable to forbid smoking on school premises. The knowledge of the dangers related to smoking is not sufficient to keep young people from smoking and confirms that an educational approach based solely on knowledge and facts will not be sufficient to decrease their tobacco consumption. It is important to take into account the image that young people have of tobacco as a means to combat stress in future prevention strategies and campaigns.

We report the identification of a Drosophila Pax gene, eye gone (eyg), which is required for eye development. Loss-of-function eyg mutations cause reduction or absence of the eye. Similar to the Pax6 eyeless (ey) gene, ectopic expression of eyg induces extra eye formation, but at sites different from those induced by ey. Several lines of evidence suggest that eygand ey act cooperatively: (1) eyg expression is not regulated by ey, nor does it regulate ey expression, (2) eyg-induced ectopic morphogenetic furrow formation does not require ey, nor does ey-induced ectopic eye production require eyg, (3) eyg and ey can partially substitute for the function of the other, and (4) coexpression of eyg and ey has a synergistic enhancement of ectopic eye formation. Our results also show that eyg has two major functions: to promote cell proliferation in the eye disc and to promote eye development through suppression of wg transcription.

Cyclooxygenase-2 (COX-2) action on the endocannabinoids, 2-arachidonylglycerol (2-AG) and anandamide (AEA), generates prostaglandin glycerol esters (PG-G) and ethanolamides (PG-EA), respectively. The diversity of PG-Gs and PG-EAs that can be formed enzymatically following COX-2 oxygenation of endocannabinoids was examined in cellular and subcellular systems. In cellular systems, glycerol esters and ethanolamides of PGE(2), PGD(2), and PGF(2alpha) were major products of the endocannabinoid-derived COX-2 products, PGH(2)-G and PGH(2)-EA. The sequential action of purified COX-2 and thromboxane synthase on AEA and 2-AG provided thromboxane A(2) ethanolamide and glycerol ester, respectively. Similarly, bovine prostacyclin synthase catalyzed the isomerization of the intermediate endoperoxides, PGH(2)-G and PGH(2)-EA, to the corresponding prostacyclin derivatives. Quantification of the efficiency of prostaglandin and thromboxane synthase-directed endoperoxide isomerization demonstrated that PGE, PGD, and PGI synthases catalyze the isomerization of PGH(2)-G at rates approaching those observed with PGH(2). In contrast, thromboxane synthase was far more efficient at catalyzing PGH(2) isomerization than at catalyzing the isomerization of PGH(2)-G. These results define the in vitro diversity of endocannabinoid-derived prostanoids and will permit focused investigations into their production and potential biological actions in vivo.

teashirt (tsh) encodes a Drosophila zinc-finger protein. Misexpression of tsh has been shown to induce ectopic eye formation in the antenna. We report that tsh can suppress eye development. This novel function of tsh is due to the induction of homothorax (hth), a known repressor of eye development, and requires Wingless (WG) signaling. Interestingly, tsh has different functions in the dorsal and ventral eye, suppressing eye development close to the ventral margin, while promoting eye development near the dorsal margin. It affects both growth of eye disc and retinal cell differentiation.

The two main mutations of the HFE (haemochromatosis) gene, C282Y and H63D, were found previously to be rare or absent among Africans. Dried blood samples of 1276 newborns from southern France were analysed for both HFE mutations, and the origins of the four grandparents of each newborn were recorded. The allele frequency of C282Y and H63D was 3.0% +/- 0.7% and 16.9% +/- 1.5% respectively. In a subgroup of 171 newborns with four North African ancestries (mainly from Morocco and Algeria) the allele frequency was 0.9%+2.5%-0.2% for the C282Y and 13.2% +/- 3.6% for H63D. HFE mutations are not absent in individuals with North African origins living in southern Europe. This finding has implications for the diagnosis and screening of hereditary haemochromatosis in these populations.

We identified an Arabidopsis thaliana gene, AtMAP3Kepsilon1, and a Brassica napus cDNA, BnMAP3Kepsilon1, encoding functional protein serine/threonine kinases closely related to cdc7p and Cdc15p from Schizosaccharomyces pombe and Saccharomyces cerevisiae, respectively. This is the first report of cdc7-related genes in non-fungal eukaryotes; no such genes have as yet been identified in Metazoans. The B. napus protein is able to partially complement a cdc7 loss of function mutation in S. pombe. RT-PCR and in situ hybridisation revealed that the A. thaliana and B. napus genes are expressed in both the sporophytic and the gametophytic tissues of the respective plant species and revealed further that expression is highest in dividing cells. Moreover, AtMAP3Kepsilon1 gene expression is cell cycle-regulated, with higher expression in G2-M phases. Our results strongly suggest that the plant cdc7p-related protein kinases are involved in a signal transduction pathway similar to the SIN pathway, which positively regulates cytokinesis in S. pombe.

The Drosophila Homothorax (HTH) and Extradenticle (EXD) are two homeoproteins required in a number of developmental processes. EXD can function as a cofactor to Hox proteins. Its nuclear localization is dependent on HTH. In this study we present evidence of in vivo physical interaction between HTH and EXD, mediated primarily through an evolutionarily conserved MH domain in HTH. This interaction is essential for the mutual stabilization of both proteins, for EXD nuclear localization, and for the cooperative DNA binding of the EXD–HTH heterodimer. Some in vivo functions require both EXD and HTH in the nucleus, suggesting that the EXD–HTH complex may function as a transcriptional regulator.

The phosphorus nuclear spin‐lattice relaxation rate 1/T1 has been measured in the quasi‐two‐dimensional XY antiferromagnet BaNi2(PO4)2. The divergence observed just above the ordering temperature TN ≂ 23.6 K is analyzed within the context of the Kosterlitz–Thouless transition. For a magnetic field H perpendicular to the XY plane, the data presented here agree well with a recent model of freely moving vortices. The field dependence observed for H parallel suggests a drastic slowing down of the vortex velocity in that case.

A unique case of benign sacrococcygeal teratoma associated with an N-type rectobulbar fistula is reported.

A SMT3 cDNA encoding ubiquitin-like protein from Drosophila melanogaster was isolated and sequenced. Drosophila SMT3 genomic DNA was amplified by polymerase chain reaction, and its nucleotide sequence was found to be identical to that of the cDNA, indicating the absence of intron in its protein coding region. The sequence of 90 amino acids of Drosophila SMT3 exhibited 55%, 73%, 70% and 52% identity to yeast SMT3, human SMT3A, SMT3B and SMT3C protein.

Considered for a long time as a simple chemical of great industrial importance, then in turn as a poison and a pollutant, more recently as an important endogenous and ubiquitous gas in mammals, possibly as a “miraculous” gas to use in neonatal intensive care units, etc., nitric oxide has become as fascinating a molecule as molecular oxygen. The main difference between the two gases lies in the facts that we breathe air from our first cry at birth and have some culture-based understanding of air breathing, while the understanding of the various biological roles of NO, such as in the opening of the bronchial alveoles that precedes the first cry of the neonate, is still in its infancy. We think it interesting to hint at the various sources of NO on earth.

In-vitro somatic cell and tissue culture technologies have been developed to assist plant breeding. Since the first report on immature embryo culture of maize (Green and Phillips, 1975), extensive documented reports in a whole range of species (Larkin and Scowcroft, 1981; Evans et al., 1984; Maddock and Semple, 1986; Lee and Phillips, 1988; Brown, 1991; Karp, 1991, 1995) have shown undesirable genetic and cytogenetic variation between regenerated plants and the starting material. However, some papers gave the details on the production of agriculturally useful in-vitro selected traits of agronomic values. Regenerated plants varied for a wide range of agro-morphological characters. The variability associated with cell and tissue culture has been termed ‘somaclonal variation’ by Larkin and Scowcroft (1981), which is defined as ‘the variation displayed amongst plants derived from any form of cell culture’.

We report here a method for the in vivo dissection of the regulatory region of a gene in the Drosophila genome. Our system includes ( i ) the reporter genes lacZ and white to detect transcriptional enhancer and silencer activities in a target gene, ( ii ) an efficient way to induce integration of gypsy elements in the genome, and ( iii ) unidirectional blocking of regulatory activities by the gypsy element, which is dependent on the su ( Hw ) protein. The optomotor-blind ( omb ) gene was analyzed. In the omb P1 line, a P[ lacW ] construct is inserted about 1.4 kb upstream of the omb transcription start site. The lacZ reporter gene within P[ lacW ] exhibits the same expression pattern as omb . The white reporter gene is expressed in a “bipolar” pattern. We induced high frequency gypsy mobilization in omb P1 and identified two lines (D11 and D13–1) with altered eye pigmentation pattern, which is dependent on su ( Hw ) activity. A gypsy element was found inserted in the first intron of omb in D13–1 and in P[ lacW ] in D11. These results indicate that it is the blocking of regulatory activities by gypsy that caused the changes in the white reporter gene expression. The effect of these gypsy insertions on the expression patterns allowed us to predict several aspects of the organization of the regulatory elements in the omb locus.

A number of factors influence the incidence and degree of T-cell mixed chimerism following allogeneic stem cell transplantation (HSCT). The most well-recognized of these include donor source, GvHD and T-cell depletion of the graft. We hypothesized that in the ‘pro-tolerogenic’ environment following T-cell-depleted reduced intensity HSCT, viral infection could drive differential expansion of donor or recipient memory T cell (Tmem) populations, contributing to differences in the degree of mixed chimerism. Viral infection, more specifically cytomegalovirus (CMV) infection, has been shown to drive pauci-clonal T cell expansions in the early post-HSCT period, skewing T-cell repertoire reconstitution. Since CMV infection is associated with maintenance of relatively large memory T cell pools, and viral ‘reactivation’ can be associated with very large expansions of virus-specific T cells, we predicted that recipient T-cell chimerism would be greater following recipient seropositive/ donor seronegative (R+/D-) versus recipient seronegative/ donor seropositive (R-/D+) HSCT due to differential expansion of virus-specific Tmem. We evaluated the outcomes of 46 consecutive reduced intensity transplants incorporating in vivo alemtuzumab, in which these CMV serostatus combinations were present. Recipient chimerism was markedly greater in the R+/D- cohort (median 50% recipient, range 0-95% versus median 4%, range 0-95% respectively, P = 0.0044), and the correlation was greater when analysis was restricted to those with sibling donors (n=34, median 68% (2-95%) recipient versus 4% (0-95%) respectively, P = 0.0018), or to patients without grade II-IV acute or extensive chronic GvHD (n=33, median 63% (2-95%) recipient versus 2% (0-70%) respectively, P = 0.0019). At 6+ months post transplant, CMV-specific T cells accounted for 0.4-24% of the CD8+ T cell compartment. All such virus-specific T cells in R+/D- patients were recipient-derived, as demonstrated by chimerism analyses of CMV pp65-, pp50- or IE-1-specific HLA-streptamer-selected CD8+ T cells. Furthermore, chimerism was consistently more skewed towards recipient in the CD8+ as opposed to the CD4+ T cell compartment, in keeping with larger clonal burst sizes of CD8+ versus CD4+ virus-specific T cells. Since the majority of recipient-derived T cells were not CMV-specific, we hypothesize that events early post-transplant might have a role in ‘imprinting’ the level of recipient chimerism, which thereafter remains stable in the absence of GvHD. Interestingly, these recipient-derived CMV-specific T cells conferred apparent protection against multiple CMV reactivation episodes. The number of reactivation episodes and number of days on treatment within the R+/D- cohort were significantly higher for those with 10% (n=16) recipient chimerism (median 3 (range 1-10) versus 1 (1-3), P = 0.0044, and median 88 days (19-412) versus 21 days (17-63), P = 0.001, respectively). R+/D- transplants were not, therefore, generally associated with recurrent problematic CMV infection. Indeed, this scenario was largely confined to the group of patients developing GvHD, who suffered both from reduced absolute lymphocyte counts secondary to corticosteroids, and eradication of the recipient-derived T cell compartment including the CMV-specific Tmem pool. Paradoxically, this suggests that T-cell depletion may actually reduce the incidence of problematic CMV infection in this ‘high-risk’ group by facilitating persistence of recipient CMV-specific T cells. Twelve R+/D- patients received donor-lymphocytes at later time points for persistent recipient chimerism (median 78% recipient (5-95%)). All converted to Disclosures: No relevant conflicts of interest to declare.

The effects of dietary levels of tryptophan (TRP) and protein on voluntary feed intake, growth performance, muscle pH, and brain indoleamine and catecholamine concentrations were studied in an experiment involving 48 crossbred Pietrain x Large White pigs (38 kg initial weight). Equal numbers of females, intact males, and barrows were used and they were given ad libitum access to feed during the 28-d experiment. Four dietary treatments were compared in a 2 x 2 factorial arrangement, with the following levels of analyzed TRP and CP: 1) .12 and .16% TRP, suboptimum and optimum for growth, respectively, 2) 12.7% CP of a diet based on corn-soybean meal and adequately balanced for limiting essential amino acids other than TRP; and 16.7% CP diet with additional protein from corn gluten meal. Dietary CP interacted with TRP on feed intake and growth, with a greater depressive effect at .12% TRP than at .16% TRP in the three genders. Norepinephrine concentration, which was the highest in the preoptic area, was higher in females than in intact or castrated males. Serotonin concentration was increased by TRP supplementation in the different brain regions. Additional CP depressed serotonin concentration more at .12% TRP than at .16% TRP. The greater sensitivity of feed intake and growth of pigs, especially females, to TRP deficiency in the presence of additional CP may have been related to a more critical serotonergic activity, when hypothalamic serotonin concentration fell below a threshold level. Supplemental TRP increased muscle pH, both at 45 min and 24 h after death, in ham (adductor femoris and semimembranosus) and loin (longissimus), suggesting a sedative effect of TRP for reducing stress response.

An experiment involving 110 crossbred pigs (Pietrain x Large White) was conducted in order to evaluate the requirement for digestible lysine during the finishing period. Two periods were considered: 50 to 80 kg live weight and 80 to 110 kg live weight, with 50 pigs (25 castrated males and 25 females) in each of them. Ten additional pigs were slaughtered and dissected at 50 kg live weight in order to estimate the initial body composition of experimental animals. Five increasing levels of lysine supply were tested for each period and gender. From 50 to 80 kg, average daily gain (ADG) increased linearly with lysine supply whereas a linear-plateau response was measured from 80 to 110 kg, up to a maximum response of 930 g/d for a supply of 17.2 g digestible lysine per day. For a same daily supply of lysine, ADG and feed conversion ratio (FCR) were 50 g/d and 0.5 kg/kg higher during the second than during the first period, respectively. ADG increased by 37.9 g/d, FCR decreased by 0.16 kg/kg and average daily muscle gain increased by 29 g per g of supplementary digestible lysine. For the genotype involved and the feeding level achieved in our experiment, it was concluded that the requirement for digestible lysine decreased from about 0.80 g/MJ net energy at 50 kg to 0.63 g/MJ at 100 kg live weight. The marginal efficiency of digestible lysine was around 65–70%. This value can be used for a factorial estimation of the requirement, based on daily protein deposition. More empirical predictive equations, based on ADG or muscle gain, are also proposed.

In this work we explore the structural and magnetic properties of a distorted S = 1/2 pyrochlore antiferromagnet: the mineral clinoatacamite, gamma-Cu-2(OH)(3)Cl. DC magnetization and specific heat data demonstrate its high degree of frustration (\theta(w)\/T-c = -30) and reveal that the Neel groundstate, observed below T-c similar or equal to 6K, features extensive quantum fluctuations. Inelastic neutron scattering is used to quantify the characteristic energy scales of the system. (C) 2004 Elsevier B.V. All rights reserved.

Three of the four eukaryotic ribosomal RNA molecules (18S, 5.8S and 25-28S rRNA) are transcribed as a single precursor, which is subsequently processed into the mature species by a complex series of cleavage and modification reactions. Early cleavage at site A1 generates the mature 5'-end of 18S rRNA. Mutational analyses have identified a number of upstream regions in the 5' external transcribed spacer (5' ETS), including a U3 binding site, which are required in cis for processing at A1. Nothing is known, however, about the requirement for cis-acting elements which define the position of the 5'-end of the 18S rRNA or of any other eukaryotic rRNA. We have introduced mutations around A1 and analyzed them in vivo in a genetic background where the mutant pre-rRNA is the only species synthesized. The results indicate that the mature 5'-end of 18S rRNA in yeast is identified by two partially independent recognition systems, both defining the same cleavage site. One mechanism identifies the site of cleavage at A1 in a sequence-specific manner involving recognition of phylogenetically conserved nucleotides immediately upstream of A1 in the 5' ETS. The second mechanism specifies the 5'-end of 18S rRNA by spacing the A1 cleavage at a fixed distance of 3 nt from the 5' stem-loop/pseudoknot structure located within the mature sequence. The 5' product of the A1 processing reaction can also be identified, showing that, in contrast to yeast 5.8S rRNA, the 5'-end of 18S rRNA is generated by endonucleolytic cleavage.

Both theoretical and experimental analysis of the fluctuational magnetization of quasi-2D superconductors is performed. The obtained theoretical expression is valid in the Gaussian regime of fluctuations for arbitrary anisotropy and describes very well the presented experimental data on YBa 2 Cu 3 O 7−δ while 2D or 3D scaling fail.

Three experiments were conducted with 188 finishing pigs (females and castrated males) of the Large White breed, between mean body weights (BW) of 53 and 88 kg, and fed according to a feeding scale, to study the effects of dietary tryptophan (TRP) deficiency (0.10 vs. 0.13%) on feed intake, growth performance, body composition and tissue gain, and meat quality, according to age or BW at slaughter or BW gain. TRP deficiency depressed feed intake, growth performance, and tissue (muscle and fat) gains, with less pronounced effect with advancing age. Females were more sensitive to TRP deficiency than castrated males. The weights of lean and fat joints both decreased with TRP deficiency in pigs slaughtered at the same age, with no resulting change in carcass composition, while they were similar to those in control animals after slaughter at the same BW. The addition of dietary limiting TRP affected carcass conformation through preferential stimulation of development in depth (forehand, hindquarter) compared to development in length, thus producing longer carcasses at the same age at slaughter, but shorter carcasses when pigs were slaughtered at the same BW. This was also the case after feed restriction, for similar gain as in TRP-deficient animals. There was no effect of dietary TRP on muscle quality characteristics. The results were discussed in relation to the common stimulating effect of the limiting dietary factor for growth, whether amino acid or energy, on the development of the early maturing body compartments and the resulting changes in carcass conformation according to age or weight at slaughter.

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In this review we recall the main physical properties of nitric oxide. The irreversible reactions of NO with O2 and O2.-, which yield strongly oxydant and nitrosating, and therefore toxic, species, are described in kinetic terms. Nearly all metalloproteins are potential targets for NO, often detectable by EPR spectroscopy. The case of hemoglobin in vitro and within circulating erythrocytes, especially in pathophysiological cases, is particularly described. A few examples of hemoproteins activated or inhibited by NO are given. Results obtained with cellular systems responding to cytokines are summarized, together with the effects of NO synthesis on [FeS] clusters-containing proteins, on ribonucleotide reductase and on the proteins implicated in iron metabolism.

Nitric oxide (NO) synthesized by macrophages inhibits tumor cell replication. NO also inhibits ribonucleotide reductase, an enzyme essential for DNA synthesis, probably by quenching the catalytically active tyrosyl free radical of its R2 subunit. The role of this inhibition in NO-mediated cytostasis was thus evaluated. After a 4-h coculture with macrophages, quenching of the radical was demonstrated by electron paramagnetic resonance spectroscopy in transfected L1210-R2 cells over-expressing the R2 protein. Pronounced cytostasis was simultaneously observed. A NO synthase inhibitor greatly reduced both phenomena. Target cells withdrawn from macrophages partially recovered from cytostasis and radical loss within 90 min. Deoxyribonucleosides added to by-pass ribonucleotide reductase inhibition efficiently reversed cytostasis of K-562 cells. After a 24-h coculture, the quenched tyrosyl radical still reappeared in L1210-R2 cells withdrawn from macrophages, but DNA synthesis did not resume. Moreover, deoxyribonucleosides marginally reversed overnight cytostasis of K-562 cells mediated by macrophages but were efficient against cytostasis induced by hydroxyurea, a ribonucleotide reductase inhibitor. Autocrine cytostasis observed early in TA3-H2 cells committed to produce NO was closely correlated with quenching of the tyrosyl radical but not with formation of dinitrosyl-iron complexes. We thus propose that NO-dependent cytostasis begins with a rapid and reversible inhibition of ribonucleotide reductase, progressively reinforced by other, long-lasting antiproliferative effects.

We have developed techniques for the detailed analysis of cis-acting sequences in the pre-rRNA of Saccharomyces cerevisiae and used these to study the processing of internal transcribed spacer 1 (ITS1) leading to the synthesis of 5.8S rRNA. As is the case for many eukaryotes, the 5' end of yeast 5.8S rRNA is heterogeneous; we designate the major, short form 5.8S(S), and the minor form (which is seven or eight nucleotides longer) 5.8S(L). These RNAs do not have a precursor/product relationship, but result from the use of alternative processing pathways. In the major pathway, a previously unidentified processing site in ITS1, designated A3, is cleaved. A 10 nucleotide deletion at site A3 strongly inhibits processing of A3 and the synthesis of 5.8S(S); processing is predominantly transferred to the alternative 5.8S(L) pathway. Site A3 lies 76 nucleotides 5' to the end of 5.8S(S), and acts as an entry site for 5'-->3' exonuclease digestion which generates the 5' end of 5.8S(S). This pathway is inhibited in strains mutant for XRN1p and RAT1p. Both of these proteins have been reported to have 5'-->3' exonuclease activity in vitro. Formation of 5.8S(L) is increased by mutations at A3 in cis or in RAT1p and XRN1p in trans, and is kinetically faster than 5.8S(S) synthesis.

Nitric oxide is synthesized in mammalian cells from L-arginine or from pharmaceutical drugs. It forms paramagnetic complexes with some metalloproteins, including hemoglobin. Induction of NOSi following LPS or cytokine activation of murine macrophages has various effects, such as inhibition of mitochondrial respiration and that of DNA biosynthesis through interaction of NO with specific metalloenzymes. Induction of NOSi in a generator cell such as macrophage gives the same metabolic effects in target cells. NO is also detected in pathological states such as septic shock, diabetes mellitus and allograft, where the inducible L-arginine-NO pathway plays an important role. Electron Paramagnetic Resonance spectroscopy enables to detect unambiguously such specific molecular targets for NO in mammalian whole cells and organelles.

The specific heat of a large YBa2Cu3O6.92 single crystal (m≈150 mg) was measured between 0 and 27 Tesla. In contrast with previous results obtained at lower fields, the specific heat above Tc is field-dependent up to 100 K. The high magnetic fields combined with a narrow transition width (ΔTc10–90%=0.15 K in ac susceptibility) allow an accurate analysis of the different contributions in the vicinity of Tc(H=0). 2D–3D gaussian and 3D-xy critical fluctuations models are compared. A positive curvature of Hc2(T) line is observed up to 10 Tesla. The compatibility of the calorimetric and magnetic measurements [1] through Maxwell's relation is also verified.

Different energy values are given to a given feed according, firstly, to the considered step of energy utilization by the pig (digestible (DE), metabolizable (ME) or net (NE) energy) and, secondly, to the prediction method used for each step. The aspects developed in the first part of this review relate to the effects of chemical composition of the diet and animal factors such as physiological stage or body weight, and also the interactions between diet and animal, on digestive and metabolic utilization of energy. In a second part, the available DE, ME and NE systems when applied to diets or ingredients are presented. In the third part, the different energy systems (firstly DE vs. ME vs. NE, and secondly the NE systems) are compared in terms of advantages, limits and applicability for each of them. The comparison indicates that the hierarchy between diets and, more clearly, between ingredients is markedly dependent on the energy system. The composition of diets (ingredients and chemical characteristics) resulting from least-cost formulation is also affected by the energy system. The last part of the review considers the validity of the different energy systems or their ability to predict pig performance. From this review, it is clear that more emphasis should be given to, firstly, study digestive interactions and, secondly, improve the methods (chemical, physical, in vitro, …) used for (rapid) prediction of energy values of pig feeds.

The effect of the 1RS chromosome arm from rye on plant regeneration from microspore-derived embryos was studied using anther culture technology with genotypes carrying the 1BL–1RS translocated chromosomes, the normal wheat chromosome 1BL–1BS, and ditelosomic lines DT 1BS and DT 1BL. A significant difference was observed in microspore-derived green plants between chromosome structure concerned with 1RS and 1BS arms. An analysis of the inheritance of the 1B–1R translocation was performed on the basis of the frequency of male gametes 1BL–1RS in the microspore-derived green plants and that of the 1B–1R translocation inherited through the pollen or the egg cell from structurally heterozygous hybrids 1BL–1BS/1BL–1RS. Both the normal 1B and the translocated 1BL–1RS chromosomes were sexually transmitted through the pollen grains with the same frequency. The 1BL–1RS chromosome is only transmitted through 45% of the egg cells. On the contrary, two-thirds of the microspore-derived green plants regenerated from the anther culture experiments possess the translocated chromosome. The involvement of the rye chromosome arm 1RS from 'Aurora' on regeneration capacity of the microspore-derived embryos has been proposed through the effect of a "gametophytic gene."Key words: anther culture, 1RS arm, gametophytic gene.

Two series of small CeAl 3 single crystals obtained by different methods have been characterized by X-ray and neutron diffraction, SEM and metallographic analysis. Magnetic susceptibility, specific heat and transport properties confirm that CeAl 3 single crystals behave quite differently from polycristalline samples. All data argue for a moderate-moment magnetically ordered Kondo state below a temperature of about 1–2 K which appears to be very sample dependent.

Self-selection of dietary lysine was studied in one 42-d experiment involving 100 Large White growing pigs, with an equal number of females and castrated males, initially weighing 17.7 kg, within 5 treatments of 20 animals in each. A common basal diet (17% CP, 13.8 MJ DE/kg) based on maize, soybean meal and peanut meal, and containing a deficient level of lysine (0.61%), was used. Supplementary L-lysine was provided to obtain suboptimal (0.74%), optimal (0.85%) and superoptimal (1.21%) levels of total lysine for growth, as assumed from usual recommendations. In addition to treatment 1, a control where pigs were fed ad libitum a single diet with 0.85% lysine, 4 treatments with free choice of lysine within paired diets were compared. These included deficient or suboptimal levels of lysine on the one hand and optimal or superoptimal levels on the other according to a 2 x 2 factorial plan: 0.61 vs 0.85% (treatment 2), 0.74 vs 0.85% (treatment 3), 0.61 vs 1.21% (treatment 4), 0.74 vs 1.21% (treatment 5). The results showed sex difference in diet selection according to lysine content. Females had a distinct preference for the superoptimal level (1.21%) compared to the optimal level (0.85%), especially during the initial period of the trial, their requirement being higher than the presupposed 0.85% optimal level. For castrated males, the preference for lysine was restricted to the lower 0.85% level. The ability of females to self-select a greater proportion of the high lysine feed as opposed to castrated males was related to a higher potential for lean tissue growth. These results confirm that the growing pig is able to differentiate between diets differing only in their lysine contents. Complementary observations on plasma-free amino acids suggested the use of diets adequately balanced for amino acids when offered for free choice.