Monoaminergic neurons in the brain of goldfish as observed by immunohistochemical techniques

With an immunofluorescent technique, catecholaminergic neurons were identified for the first time in the dorsal and medial thalamus and in the ventralis telencephali (the rostro-medial part of the lobus olfactorius) of the goldfish brain. Serotonin-containing neurons were found in the pretectal area.     

Alteration of capsular type of encapsulated strains ofStaphylococcus aureus during freeze-drying and storage

Summary Remarkable alteration was shown in capsular type antigen production in encapsulated strains ofStaphylococcus aureus stored by lyophilization for 10 years. This alteration was further elucidated by antibody production in rabbits immunized with the altered strain and by absorbing the antibodies with representative capsular type strains.     

L-threo-3,4-dihydroxyphenylserine, a noradrenaline precursor, inhibits dopamine release and metabolism in the rat striatum in vivo.

The effect of L-threo-3,4-dihydroxyphenylserine (L-threo-DOPS) on dopamine (DA) release and metabolism in the striatum was studied in freely moving rats by intracerebral microdialysis techniques. The DA level as well as the levels of 3,4-dihydroxyphenylacetic acid and homovanillic acid were significantly decreased 140 min after the administration of L-threo-DOPS (50 mg/kg intraperitoneally). The results suggest that L-threo-DOPS inhibits the release and metabolism of DA in the striatum.     

The acceleration of cosmic-ray protons in the supernova remnant RX J1713.7-3946

Protons with energies up to approximately 10(15) eV are the main component of cosmic rays, but evidence for the specific locations where they could have been accelerated to these energies has been lacking. Electrons are known to be accelerated to cosmic-ray energies in supernova remnants, and the shock waves associated with such remnants, when they hit the surrounding interstellar medium, could also provide the energy to accelerate protons. The signature of such a process would be the decay of pions (pi(0)), which are generated when the protons collide with atoms and molecules in an interstellar cloud: pion decay results in gamma-rays with a particular spectral-energy distribution. Here we report the observation of cascade showers of optical photons resulting from gamma-rays at energies of approximately 10(12) eV hitting Earth's upper atmosphere, in the direction of the supernova remnant RX J1713.7-3946. The spectrum is a good match to that predicted by pion decay, and cannot be explained by other mechanisms.     

A plant receptor-like kinase required for both bacterial and fungal symbiosis

Most higher plant species can enter a root symbiosis with arbuscular mycorrhizal fungi, in which plant carbon is traded for fungal phosphate. This is an ancient symbiosis, which has been detected in fossils of early land plants. In contrast, the nitrogen-fixing root nodule symbioses of plants with bacteria evolved more recently, and are phylogenetically restricted to the rosid I clade of plants. Both symbioses rely on partially overlapping genetic programmes. We have identified the molecular basis for this convergence by cloning orthologous SYMRK ('symbiosis receptor-like kinase') genes from Lotus and pea, which are required for both fungal and bacterial recognition. SYMRK is predicted to have a signal peptide, an extracellular domain comprising leucine-rich repeats, a transmembrane and an intracellular protein kinase domain. Lotus SYMRK is required for a symbiotic signal transduction pathway leading from the perception of microbial signal molecules to rapid symbiosis-related gene activation. The perception of symbiotic fungi and bacteria is mediated by at least one common signalling component, which could have been recruited during the evolution of root nodule symbioses from the already existing arbuscular mycorrhiza symbiosis.     

BRI1 is a critical component of a plasma-membrane receptor for plant steroids

Most multicellular organisms use steroids as signalling molecules for physiological and developmental regulation. Two different modes of steroid action have been described in animal systems: the well-studied gene regulation response mediated by nuclear receptors, and the rapid non-genomic responses mediated by proposed membrane-bound receptors. Plant genomes do not seem to encode members of the nuclear receptor superfamily. However, a transmembrane receptor kinase, brassinosteroid-insensitive1 (BRI1), has been implicated in brassinosteroid responses. Here we show that BRI1 functions as a receptor of brassinolide, the most active brassinosteroid. The number of brassinolide-binding sites and the degree of response to brassinolide depend on the level of BRI1 protein. The brassinolide-binding activity co-immunoprecipitates with BRI1, and requires a functional BRI1 extracellular domain. Moreover, treatment of Arabidopsis seedlings with brassinolide induces autophosphorylation of BRI1, which, together with our binding studies, shows that BRI1 is a receptor kinase that transduces steroid signals across the plasma membrane.     

IKKalpha controls formation of the epidermis independently of NF-kappaB

The IKKalpha and IKKbeta catalytic subunits of IkappaB kinase (IKK) share 51% amino-acid identity and similar biochemical activities: they both phosphorylate IkappaB proteins at serines that trigger their degradation. IKKalpha and IKKbeta differ, however, in their physiological functions. IKKbeta and the IKKgamma/NEMO regulatory subunit are required for activating NF-kappaB by pro-inflammatory stimuli and preventing apoptosis induced by tumour necrosis factor-alpha (refs 5,6,7,8,9,10,11). IKKalpha is dispensable for these functions, but is essential for developing the epidermis and its derivatives. The mammalian epidermis is composed of the basal, spinous, granular and cornified layers. Only basal keratinocytes can proliferate and give rise to differentiated derivatives, which on full maturation undergo enucleation to generate the cornified layer. Curiously, keratinocyte-specific inhibition of NF-kappaB, as in Ikkalpha-/- mice, results in epidermal thickening but does not block terminal differentiation. It has been proposed that the epidermal defect in Ikkalpha-/- mice may be due to the failed activation of NF-kappaB. Here we show that the unique function of IKKalpha in control of keratinocyte differentiation is not exerted through its IkappaB kinase activity or through NF-kappaB. Instead, IKKalpha controls production of a soluble factor that induces keratinocyte differentiation.     

Human specific immunoglobulin protects against infection with commonStaphylococcus in mice

Summary Mice infected with non-capsulatedStaphylococcus aureus strains highly resistant to methicillin survived after the administration of specific immunoglobulin extracted from pooled human sera by using homologous capsular type strains, but no protective effect was shown with a conventional immunoglobulin preparation and methicillin, even with high doses.     

Developmental changes of aldehyde dehydrogenase isozymes in human livers: mitochondrial ALDH2 isozyme is expressed in fetal livers

Previous reports suggested that the major cytosolic aldehyde dehydrogenase (ALDH1) was present in fetal and infant livers, but the major mitochondrial isozyme (ALDH2) was absent or severely diminished. Re-examination by means of starch gel electrophoresis followed by enzyme activity staining, and by means of dot blot immuno-hybridization of liver samples with known genotypes of the ALDH2 locus, indicated that both ALDH1 and ALDH2 genes are expressed in fetal and infant livers. In addition, ALDH4 isozyme was also observed. The results imply that a fetus with the 'usual' homozygous ALDH1(2)/ALDH1(2) genotype, but not one with the atypical ALDH1(2)/ALDH2(2) or ALDH2(2)/ALDH2(2), is capable of detoxifying acetaldehyde transferred from the mother.     

Effect of carbon particles on the recovery of bone marrow stem cells after irradiation in LPS-resistant C3H/HeJ mice

Summary Effect of RES-blockade on bone marrow cells was studied serially after irradiation in LPS-resistant mice. Injection of carbon particles reduced damage and accelerated recovery of marrow hemopoietic stem cells, indicating that LPS-resistant mice can react normally to RES-blockade.This work was supported in part by a Grant-in-Aid for Cancer Research from the Ministry of Education, Science and Culture, Japan.