CD14 is a member of the family of leucine-rich proteins and is encoded by a gene syntenic with multiple receptor genes.

We have isolated and characterized genomic and cDNA clones encoding the murine homolog of the human monocyte/granulocyte cell surface glycoprotein, CD14. As in man, the expression of murine CD14 is limited to the myeloid lineage. The murine and human CD14 genes are highly conserved in their intron-exon organization and nucleotide sequence. Their deduced protein sequences show 66% amino acid identity. In both mouse and man, the CD14 protein contains a repeating (10 times) leucine-rich motif (LXXLXLX) that is also found in a group of heterogeneous proteins from phylogenetically distant species. The CD14 gene has been mapped to mouse chromosome 18 which also contains at least five genes encoding receptors (Pdgfr, Adrb2r, li, Grl-1, Fms). Thus CD14 and the receptor genes form a conserved syntenic group localized on mouse chromosome 18 and human chromosome 5. The inclusion of CD14 in the family of leucine-rich proteins, its expression profile and the murine chromosomal localization support the hypothesis that CD14 may function as a receptor.     

Immunodetection of secretogranin II in animal and human tissues by new monoclonal antibodies.

Secretogranin II (chromogranin C) is an acidic tyrosine-sulfated secretory protein, known to be a marker of neuroendocrine secretory products and of specific neuroendocrine tumours. In order to obtain anti-secretogranin II monoclonal antibodies for cell biology studies and, in particular, for clinical applications, we immunized mice with a secretogranin II-enriched fraction prepared from homogenates of bovine anterior pituitaries. Hybridoma supernatants obtained from the splenocytes of a hyperimmune mouse, screened with an enzyme-linked immunosorbent assay, were analyzed by both immunocytochemistry and two-dimensional immunoblotting. By using this experimental approach, we were able to identify two monoclonal antibodies (8G1 and 5A7) which recognize bovine secretogranin II. Both immunocytochemistry and immunoblotting revealed that one of them, the 5A7 antibody, cross-reacts with the human antigen. The distribution patterns of the immunoreactivity, obtained by immunocytochemistry with the 5A7 antibody in animal and human tissues, partially overlap those, obtained by using a polyclonal antiserum elicited against bovine secretogranin II, previously described. Moreover, the 5A7, but not the polyclonal antibody, reacts with some duodeno-jejunal cells. In conclusion, both the 5A7 and 8G1 antibodies can be useful for cell biology studies. The 5A7 antibody can be used for the detection of secretogranin II in human tissues and should be of help in clinical and pathological practices.     

Induction of differentiation in human HL-60 cells by 4-hydroxynonenal, a product of lipid peroxidation

4-Hydroxynonenal (HNE) is the major diffusible toxic product generated by lipid peroxidation of cellular membranes. The level of lipid peroxidation and, consequently, the concentration of its products are inversely related to the rate of cell proliferation and directly related to the level of cell differentiation. In the present paper the effects of HNE on the proliferation and differentiation of the HL-60 human promyelocytic cell line have been investigated. Repeated treatment at 45-min intervals with HNE (1 microM) was performed to maintain the cells in the presence of the aldehyde for 7 1/2 or 9 h. The effect of HNE on cell proliferation and differentiation was compared with dimethyl sulfoxide (DMSO)-treated cells. HNE causes a strong inhibition of cell growth without affecting cell viability. Moreover, HL-60 cells acquire the capability to produce chemiluminescence after soluble (phorbol myristate acetate) or corpuscolate (zymosan) stimulation. The phagocytic ability has also been calculated by counting the number of cells that phagocytize opsonized zymosan. Values were 43 and 55% after 10 or 12 HNE treatments, respectively, and 88% in DMSO-treated cells. Myeloperoxidase activity, 5 days after treatment, decreased by 85% in either HNE- or DMSO-treated cells while acid phosphatase activity increased with respect to untreated cells. Results obtained indicate that HNE at concentrations close to those found in the normal tissues can induce inhibition of proliferation and induction of differentiation in the HL-60 cell line.     

Expression of the HSP 70 gene family in rat hepatoma cell lines of different growth rates

We have studied the expression of different members of the HSP 70 gene family in MH1C1, FAO, and 3924A hepatoma cell lines, which possess different growth rates and show different levels of histone H3 gene expression. The cells have been subjected to mild (42 degrees C/1 h) or severe (45 degrees C/25 min) heat shock that causes a decrease in cell proliferation and histone H3 gene expression correlated to the severity of stress: previous mild heat shock protects against the effects of the subsequent severe exposure. All cell lines, irrespective of their growth rate, show a high constitutive expression of the HSC 73 gene, which is barely detectable in normal liver, and a good induction of the heat-inducible HSP 70 gene, which, however, seems to be induced less than in the normal tissue. The relative amount of grp 78 mRNA is high in all hepatoma cells lines, but only FAO cells maintain a significant expression of the albumin gene. The basic diversity in HSP 70 family gene expression between normal and tumors is still maintained in hepatoma cell lines, but the growth-related, quantitative differences among the transplantable hepatomas that we previously found in the animal (Bardella et al., Br. J. Cancer 55, 642-645, 1987; Cairo et al., Hepatology 9, 740-746, 1989), seem to be lost, or at least strongly blunted, in vitro.     

Ultrafast Depolarization of Transient Absorption as a Probe of Plasmonicity of Optical Transitions in Ag Nanoclusters

Time-resolved polarization-dependent transient absorption has been used to study the plasmonicity of the optical transitions of Ag nanoparticles and nanoclusters. The lack of a measureable polarization anisotropy in the nanoparticles is indicative of the ultrafast electron-electron scattering while the anisotropy with a depolarization timescale of 500 fs observed in the nanoclusters indicates the excitation of a non-plasmonic state. The short lifetime of the anisotropy is a measure of electronic coupling between nearly degenerate states and is thus proposed as a sensitive measurement of the plasmonic content of the optical transitions of nanoclusters.

     

Early Exposure to Ketamine Impairs Axonal Pruning in Developing Mouse Hippocampus

Mounting evidence suggests that prolonged exposure to general anesthesia (GA) during brain synaptogenesis damages the immature neurons and results in long-term neurocognitive impairments. Importantly, synaptogenesis relies on timely axon pruning to select axons that participate in active neural circuit formation. This process is in part dependent on proper homeostasis of neurotrophic factors, in particular brain-derived neurotrophic factor (BDNF). We set out to examine how GA may modulate axon maintenance and pruning and focused on the role of BDNF. We exposed post-natal day (PND)7 mice to ketamine using a well-established dosing regimen known to induce significant developmental neurotoxicity. We performed morphometric analyses of the infrapyramidal bundle (IPB) since IPB is known to undergo intense developmental modeling and as such is commonly used as a well-established model of in vivo pruning in rodents. When IPB remodeling was followed from PND10 until PND65, we noted a delay in axonal pruning in ketamine-treated animals when compared to controls; this impairment coincided with ketamine-induced downregulation in BDNF protein expression and maturation suggesting two conclusions: a surge in BDNF protein expression “signals” intense IPB pruning in control animals and ketamine-induced downregulation of BDNF synthesis and maturation could contribute to impaired IPB pruning. We conclude that the combined effects on BDNF homeostasis and impaired axon pruning may in part explain ketamine-induced impairment of neuronal circuitry formation.     

Molecular characterization of Lactobacillus casei strains

Abstract The monoclonal antibody LA7 was raised against the species-specific Borrelia burgdorferi lipoprotein P22 (= IPLA7), which induces antibody formation in patients with Lyme arthritis. It is composed of 194 amino acids with a calculated molecular mass of 21.8 kDa. Its gene on the linear chromosome is 582 nucleotides in length. The aim of this study was to localize the protein P22 by immune electron microscopy. Immunolabeling of Borrelia burgdorferi with LA7 and an anti-mouse immunogold conjugate proved that P22 is an outer membrane protein. This finding was confirmed by sodium dodecyl sulfate polyacrylamide gel electrophoresis of the outer envelope fraction, which contained 99% of the P22 proteins.     

An Ultrastructural Account of Otoplanid Turbellaria Neuroanatomy II. The statocyst design: evolutionary and functional implications

The statocyst architecture in the three otoplanid species Notocaryoturbella bigermaria Lanfranchi, 1969, Otoplana truncaspina Lanfranchi, 1969 and Parotoplanella heterorhabditica Lanfranchi, 1969 is compared. Common features are: (a) a fibrillar collagen-like, 0.2 μm thick, investing capsule continuous with the brain capsule; (b) an inner wall made up of six or more flattened and overlapping parietal cells; (c) a statolith forming cell hanging from the dorsal side down in the lumen, with a large statolith containing vacuole; (d) a bilateral pair of spindle shaped accessory cell groups, adjoining the statolith cell and sending projections to the wall—nerve projections run through the capsule; (e) one accessory cell enveloping the other cells of the group has a filament containing cytoplasm, the filaments coverging into a hemidesmosome making contact with a projection coming from a parietal cell; (f) muscles from the longitudinal body musculature inserting onto the capsule externally. The lack of ciliary structures differentiates the turbellarian statocyst from the majority of invertebrate statocysts. The developmental origin, the phylogenetical meaning and the functional and adaptive value of the statocyst in Turbellaria are here commented on.