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1.
Chemical and physical methods for dating skeletal remains were examined. Benzidine reaction, ultra-violet fluorescence, specific gravity and supersonic conductivity were carried out on 71 dated skeletal findings distributed over the span of the last 3,500 years. Results given by benzidine reaction and ultra-violet fluorescence basically coincide, and positive readings were obtained up to about 200–350 years. Values measured in specific gravity and supersonic conductivity testing show a parallel trend, pointing out a clear difference between samples of the three first centuries and the ones belonging to more ancient periods examined. 相似文献
2.
Mariani E Roda P Mariani AR Vitale M Degrassi A Papa S Manzoli FA Facchini A 《Cytotechnology》1987,1(1):103-105
Old subjects exhibit a decline in circulating T cells and an impaired proliferative response to mitogens, plus a relative increase in cells with NK phenotype not associated with a concomitant increase in their cytolitic activity.In the present study a limiting dilution assay was used to evaluate the phenotype, the functional activity and the proliferative capacity of clones obtained from peripheral blood lymphocytes of old and young subjects. CD5+ CD8+ clones from old people showed a significant impairment in their proliferative capacity and a decreased lytic activity against K562 and P815-IgG cell lines. 相似文献
3.
Summary A thermodynamic model of particle adhesion from a suspension onto a solid surface is used to predict the extent of adhesion of suspension-cultured Catharanthus roseus cells to the following polymer substrates: fluorinated ethylene-propylene (FEP), polystyrene (PS), polyethylene terephthalate (PET), sulphonated polystyrene (SPS), and glass. According to this model, the extent of adhesion is determined by the surface tensions of the plant cells, the polymer substrates, and the suspending liquid medium. Experimentally, adhesion of the washed plant cells was found to decrease with increasing substrate surface tension, following the sequence FEP>PS>PET>SPS>glass, when the surface tension of the liquid was greater than that of the plant cells, in agreement with the model. However, adhesion increased with increasing substrate surface tension when the liquid surface tension was lower than the cellular surface tension, also in agreement with the model. When the liquid and cellular tensions were equal the extent of adhesion was independent of the substrate surface tension. This also agrees with model predictions and leads to a value for the surface tension of C. roseus cells of approximately 54 ergs/cm2 which is in agreement with a value obtained from contact angle measurements on layers of cells and sedimentation volume analysis. The cellular surface tension determined by the sedimentation volume method showed a biphasic alteration during growth cycles of C. roseus cell cultures. These variations (between 55 and 58 ergs/cm2) agree with the pattern of adhesion previously described. 相似文献
4.
Secondary metabolite biosynthesis in cultured cells of Catharanthus roseus (L.) G. Don immobilized by adhesion to glass fibres 总被引:1,自引:0,他引:1
Summary Suspension-cultured cells of Catharanthus roseus (L.) G. Don were immobilized on glass fibre mats and cultivated in shake flasks. The highly-aggregated immobilized cells exhibited a slower growth rate and accumulated reduced levels of tryptamine and indole alkaloids, represented by catharanthine and ajmalicine, in comparison to cells in suspension. The increased total protein synthesis in immobilized cells suggests a diversion of the primary metabolic flux toward protein biosynthetic pathways and away from other growth processes. In vitro assays for the specific activity of tryptophan decarboxylase (TDC) and tryptophan synthase (TS) suggest that the decreased accumulation of tryptamine in immobilized cells was due to reduced tryptophan biosynthesis. The specific activity of TDC was similar in immobilized and suspension-cultured cells. However, the expression of TS activity in immobilized cells was reduced to less than 25% of the maximum level in suspension-cultured cells. The reduced availability of a free tryptophan pool in immobilized cells is consistent with the reduced TS activity. Reduced tryptamine accumulation, however, was not responsible for the decreased accumulation of indole alkaloids in immobilized cells. Indole alkaloid accumulation increased to a similar level in immobilized and suspension-cultured cells only after the addition of exogenous secolaganin to the culture medium. The addition of tryptophan resulted in increased accumulation of tryptamine, but had no effect on indole alkaloid levels. Reduced biosynthesis of secologanin, the monoterpenoid precursor to indole alkaloids, in immobilized cells is suggested. Immobilization does not appear to alter the activity of indole alkaloid biosynthetic enzymes in our system beyond, and including, strictosidine synthase.
Offprint requests to: P. J. Facchini 相似文献
5.
6.
Excess amino acid polymorphism in mitochondrial DNA: contrasts among genes from Drosophila, mice, and humans 总被引:13,自引:3,他引:10
Recent studies of mitochondrial DNA (mtDNA) variation in mammals and
Drosophila have shown an excess of amino acid variation within species
(replacement polymorphism) relative to the number of silent and replacement
differences fixed between species. To examine further this pattern of
nonneutral mtDNA evolution, we present sequence data for the ND3 and ND5
genes from 59 lines of Drosophila melanogaster and 29 lines of D. simulans.
Of interest are the frequency spectra of silent and replacement
polymorphisms, and potential variation among genes and taxa in the
departures from neutral expectations. The Drosophila ND3 and ND5 data show
no significant excess of replacement polymorphism using the
McDonald-Kreitman test. These data are in contrast to significant
departures from neutrality for the ND3 gene in mammals and other genes in
Drosophila mtDNA (cytochrome b and ATPase 6). Pooled across genes, however,
both Drosophila and human mtDNA show very significant excesses of amino
acid polymorphism. Silent polymorphisms at ND5 show a significantly higher
variance in frequency than replacement polymorphisms, and the latter show a
significant skew toward low frequencies (Tajima's D = -1.954). These
patterns are interpreted in light of the nearly neutral theory where mildly
deleterious amino acid haplotypes are observed as ephemeral variants within
species but do not contribute to divergence. The patterns of polymorphism
and divergence at charge-altering amino acid sites are presented for the
Drosophila ND5 gene to examine the evolution of functionally distinct
mutations. Excess charge-altering polymorphism is observed at the carboxyl
terminal and excess charge-altering divergence is detected at the amino
terminal. While the mildly deleterious model fits as a net effect in the
evolution of nonrecombining mitochondrial genomes, these data suggest that
opposing evolutionary pressures may act on different regions of
mitochondrial genes and genomes.
相似文献
7.
Dall'Olio Fabio; Mariani Erminia; Tarozzi Andrea; Meneghetti Alessandra; Chiricolo Mariella; Lau Joseph T. Y.; Facchini Andrea 《Glycobiology》1997,7(4):507-513
The extent of processing of N-linked oligosaccharides and thesialylation of the target cell membranes has been positivelycorrelated with resistance to lysis mediated by NK cells, buta conclusive evidence has never been reached. Colon cancer tissuesexpress an increased activity of ß-ga-lactoside 相似文献
8.
Vincenzo Facchini John A. Timbrell 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》1980,183(2):167-173
Methods are described for the determination of 4-N-acetylhydrazinophthalazin-1-one, 4-hydrazinophthalazin-1-one, phthalazinone and s-triazolo[3,4-a]phthalazine in human urine.4-Hydrazinophthalazin-1-one and 4-N-acetylhydrazinophthalazin-1-one (following acid hydrolysis) are reacted with acetylacetone to give a distinctive pyrazole derivative which can be determined by gas chromatography using a nitrogen-specific detector.Phthalazinone and s-triazolo[3,4-a]phthalazine are measured underivatised by high-performance liquid chromatography. 相似文献
9.
Charys Palmer Fabio A Facchini Richard PO Jones Frank Neumann Francesco Peri Grisha Pirianov 《Innate immunity》2021,27(3):275
TLRs, including TLR4, play a crucial role in inflammatory-based diseases, and TLR4 has been identified as a therapeutic target for pharmacological intervention. In previous studies, we investigated the potential of FP7, a novel synthetic glycolipid active as a TLR4 antagonist, to inhibit haematopoietic and non-haematopoietic MyD88-dependent TLR4 pro-inflammatory signalling. The main aim of this study was to investigate the action of FP7 and its derivative FP12 on MyD88-independent TLR4 signalling in THP-1 derived macrophages. Western blotting, Ab array and ELISA approaches were used to explore the effect of FP7 and FP12 on TRIF-dependent TLR4 functional activity in response to LPS and other endogenous TLR4 ligands in THP-1 macrophages. A different kinetic in the inhibition of endotoxin-driven TBK1, IRF3 and STAT1 phosphorylation was observed using different LPS chemotypes. Following activation of TLR4 by LPS, data revealed that FP7 and FP12 inhibited TBK1, IRF3 and STAT1 phosphorylation which was associated with down-regulation IFN-β and IP-10. Specific blockage of the IFN type one receptor showed that these novel molecules inhibited TRIF-dependent TLR4 signalling via IFN-β pathways. These results add novel information on the mechanism of action of monosaccharide FP derivatives. The inhibition of the TRIF-dependent pathway in human macrophages suggests potential therapeutic uses for these novel TLR4 antagonists in pharmacological interventions on inflammatory diseases. 相似文献
10.