Diet of the white-dotted skate, Bathyraja albomaculata, in waters of Argentina

The present paper analyzes the diet, feeding strategy and niche width of Bathyraja albomaculata over the Patagonian continental shelf and upper slope. The diet comprised a variety of 14 small invertebrates, although the most important prey were polychaete worms. The opheliid polychaete Travisia sp. and the gammarid amphipod Cirolana sp. were the main prey present in stomach contents of B. albomaculata. No differences were found between the diets of males and females, however ontogenetic changes were detected. Skates <40 cm of disk width (DW) preyed on amphipods, and sizes >40 cm DW largely consumed polychaetes. As size increased, polychaetes became more important and the importance of amphipods decreased. B. albomaculata showed a narrow food niche and a marked specialization towards polychaetes.     

Protection against cartilage and bone destruction by systemic interleukin-4 treatment in established murine type II collagen-induced arthritis

Destruction of cartilage and bone are hallmarks of human rheumatoid arthritis (RA), and controlling these erosive processes is the most challenging objective in the treatment of RA. Systemic interleukin-4 treatment of established murine collagen-induced arthritis suppressed disease activity and protected against cartilage and bone destruction. Reduced cartilage pathology was confirmed by both decreased serum cartilage oligomeric matrix protein (COMP) and histological examination. In addition, radiological analysis revealed that bone destruction was also partially prevented. Improved suppression of joint swelling was achieved when interleukin-4 treatment was combined with low-dose prednisolone treatment. Interestingly, synergistic reduction of both serum COMP and inflammatory parameters was noted when low-dose interleukin-4 was combined with prednisolone. Systemic treatment with interleukin-4 appeared to be a protective therapy for cartilage and bone in arthritis, and in combination with prednisolone at low dosages may offer an alternative therapy in RA.     

Functional expression of the gene cu, encoding the phytotoxic hydrophobin cerato-ulmin, enables Ophiostoma quercus, a nonpathogen on elm, to cause symptoms of Dutch elm disease

We studied the involvement of the phytotoxic hydrophobin cerato-ulmin (CU) in pathogenesis and virulence of Dutch elm disease (DED) by expressing its encoding gene (cu) in Ophiostoma quercus, a nonpathogenic species on elm closely related to the DED pathogens O. ulmi and O. novo-ulmi. The production of the toxin was quantitatively determined in culture filtrates and in mycelial extracts of the transformants. Production of CU in vitro was associated with the ability to cause typical DED symptoms, consisting of foliar yellow and wilting and vascular tissue discoloration on a moderately resistant elm genotype. The presence of CU was monitored by enzyme-linked immunosorbent assay in symptomatic leaves of plants inoculated with O. quercus transformants expressing CU and found to be associated with wilt symptoms. In general, the virulence of the cu-expressing transformants, as measured in terms of vascular discoloration and percentage of defoliation, was lower than that of the mildly pathogenic isolate E2 of O. ulmi. However, one transformant (C39) displayed a virulence level intermediate between that of E2 and 182, a highly virulent isolate of O. novo-ulmi. Our results indicate that CU production influences virulence in nonaggressive strains of Ophiostoma fungi.     

Formate dehydrogenase activity in cells and outer membrane blebs of Desulfovibrio gigas

Formate dehydrogenase in Desulfovibrio gigas was measured by following the release of 14CO2 from radiolabeled formate. Experiments with whole cells using sulfate as the electron acceptor revealed optimal formate dehydrogenase activity at pH 7.0 and formate utilization followed saturation kinetics. While formate dehydrogenase was constitutively produced in pyruvate or lactate media, the formate dehydrogenase activity was markedly increased in cells grown with formate as the electron donor. In cell-free experiments with methyl viologen or 2,6 dichlorophenolindophenol, about 1% of the cellular formate dehydrogenase activity was present in blebs from the outer membrane. Electron microscopy revealed that these blebs were closed structures with diameters ranging from 80-800A and were not induced by changes in osmotic pressure or cellular autolysis. Analysis of blebs revealed the presence of lipopolysaccharides and two proteins with molecular masses of 70 and 53 kDa.     

Prepuberal intranasal dopamine treatment in an animal model of ADHD ameliorates deficient spatial attention,working memory,amino acid transmitters and synaptic markers in prefrontal cortex,ventral and dorsal striatum

Intranasal application of dopamine (IN-DA) has been shown to increase motor activity and to release DA in the ventral (VS) and dorsal striatum (DS) of rats. The aim of the present study was to assess the effects of IN-DA treatment on parameters of DA and excitatory amino acid (EAA) function in prepuberal rats of the Naples high-excitability (NHE) line, an animal model for attention-deficit hyperactivity disorder (ADHD) and normal random bred (NRB) controls. NHE and NRB rats were daily administered IN-DA (0.075, 0.15, 0.30 mg/kg) or vehicle for 15 days from postnatal days 28–42 and subsequently tested in the Làt maze and in the Eight-arm radial Olton maze. Soluble and membrane-trapped l-glutamate (l-Glu) and l-aspartate (l-Asp) levels as well as NMDAR1 subunit protein levels were determined after sacrifice in IN-DA- and vehicle-treated NHE and NRB rats in prefrontal cortex (PFc), DS and VS. Moreover, DA transporter (DAT) protein and tyrosine hydroxylase (TH) levels were assessed in PFc, DS, VS and mesencephalon (MES) and in ventral tegmental area (VTA) and substantia nigra, respectively. In NHE rats, IN-DA (0.30 mg/kg) decreased horizontal activity and increased nonselective attention relative to vehicle, whereas the lower dose (0.15 mg/kg) increased selective spatial attention. In NHE rats, basal levels of soluble EAAs were reduced in PFc and DS relative to NRB controls, while membrane-trapped EAAs were elevated in VS. Moreover, basal NMDAR1 subunit protein levels were increased in PFc, DS and VS relative to NRB controls. In addition, DAT protein levels were elevated in PFc and VS relative to NRB controls. IN-DA led to a number of changes of EAA, NMDAR1 subunit protein, TH and DAT protein levels in PFc, DS, VS, MES and VTA, in both NHE and NRB rats with significant differences between lines. Our findings indicate that the NHE rat model of ADHD may be characterized by (1) prefrontal and striatal DAT hyperfunction, indicative of DA hyperactivty, and (2) prefrontal and striatal NMDA receptor hyperfunction indicative of net EAA hyperactivty. IN-DA had ameliorative effects on activity level, attention, and working memory, which are likely to be associated with DA action at inhibitory D2 autoreceptors, leading to a reduction in striatal DA hyperactivity and, possibly, DA action on striatal EAA levels, resulting in a decrease of striatal EAA hyperfunction (with persistence of prefrontal EAA hyperfunction). Previous studies on IN-DA treatment in rodents have indicated antidepressant, anxiolytic and anti-parkinsonian effects in relation to enhanced central DAergic activity. Our present results strengthen the prospects of potential therapeutic applications of intranasal  DA by indicating an enhancement of selective attention and working memory in a deficit model.     

Subcellular localization of DNA-binding protein BA by immunofluorescence and immunoelectron microscopy

Nonhistone protein BA has been shown to decrease in amount in the chromatin of growth- stimulated normal rat liver (Yeoman et al. 1975. Cancer Res. 35:1249-1255) and in mitogen-stimulated normal human lymphocytes (Yeoman et al. 1976. Exp. Cell Res. 100:47- 55.). Subsequently, protein BA was purified and was shown to prefer to bind to double- stranded A-T-rich DNAs (Catino et al. 1978. Biochemistry. 17:983-987.). Immunization of rabbits with highly purified protein BA has resulted in the production of a specific antibody. A specific immunoreactivity for chromosomal protein BA has been demonstrated by immunoelectrophoresis and double antibody immunoprecipitation analysis with rabbit anti-BA immunoglobulin and IgG fractions. Light microscope examination of normal rat liver crysections by the indirect immunofluorescence procedure has demonstrated a cytoplasmic as well as a nuclear localization for protein BA with a pronounced perinucleolar fluorescence. Immunoelectron microscopy employing the peroxidase antiperoxidase method of antigen localization has confirmed the immunofluorescence data and has show a heterochromatin localization for protein BA. The relationship of the localization of protein BA to gene control in quiescent cells or to configurations of heterochromatin as well as the marked reduction in the amounts of protein BA which occur in stimulated growth states remains to be defined.