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41.
Giorgio Crosta Franco Brunetta Maria Luisa Ortelli Antonio Cavallo Roberto Bertolini 《Aerobiologia》1996,12(1):133-137
In the last 2 years we have conducted an aerobiological monitoring program ofCryptomeria japonica, a plant belonging to the family of Taxodiaceae that sometimes causes pollinosis in the period from February to April. Throughout 1994, we checked the incidence of its sensitization and the clinical effects in 85 subjects with correlated seasonal symptoms, who gave a positive skin prick test (SPT) for Betulaceae and/or Corylaceae. Twenty-five patients (29.4%; 19 M; 6 F; mean age, 38.8 years) all with oculorhinitis, were SPT positive to an allergenic extract ofCryptomeria. RAST confirmed this positivity in 44% of the cases. No patients showed monosensitization forCryptomeria to either SPT or RAST. Two subjects gave a positive result on specific nasal provocation. RAST inhibition showed no cross-reaction betweenCryptomeria and birch pollen. During the pollen season each patient made a list, scoring symptoms and specifying any drugs used, so we could correlate these elements with aerobiological observations. The pollen concentration probably exceeded the allergizing threshold forCryptomeria on 8 days during 3 months of recording. The intensity and duration of symptoms seemed to be mainly influenced by sensitization to Betulaceae and Corylaceae. It is thus possible that a combination of minor pollinosis may produce seasonal symptoms in allergic patients. 相似文献
42.
Giovanna Zolese Ileana Giambanco Giovanna Curatola Roberto Staffolani Enrico Gratton Rosario Donato 《Cell calcium》1996,20(6):465-474
Phase-modulation fluorescence lifetime measurements were used to study the single Trp residue of the Ca2+-binding protein S-100a both in the absence and in the presence of Ca2+ and/or Mg2+. Trp fluorescence decay for the protein was satisfactorily described by Lorentzian lifetime distributions centered around two components (approximately 4 ns and 0.5 ns). Lifetime values were unchanged by 2 mM Ca2+, but the fractional intensity associated with longer lifetime increased up to 75%. In the presence of Mg2+, the Ca2+ induced increase of the fractional intensity associated with longer lifetime was only 57%. For the protein in buffer, about the 85% of the recovered anisotropy was associated to a rotational correlation time of 6.7 ns. After the addition of Ca2+, this value was increased to 16.08 ns. In the presence of Mg2+, Ca+2 increased the rotational correlation time to 33.75 ns. Similar studies were performed with S-100a interacting with egg phosphatidylcholine vesicles (SUV). Our data suggest that the conformation of the protein may be influenced by structural features of the lipidic membrane. Moreover, data obtained in the presence of Mg2+ indicate some interaction between lipids and S-100, likely mediated by this ion. 相似文献
43.
Roberto Bovara Giacomo Carrea Sergio Riva Francesco Secundo 《Biotechnology letters》1996,18(3):305-308
Summary Cholic acid (3,7,12-trihydroxy-5-cholanoic acid) was completely and selectively transformed into 12-ketoursodeoxycholic acid (3,7-dihydroxy-12-oxo-5-cholanoic acid) by means of two consecutive enzymatic steps catalyzed, the first, by 7- and 12-hydroxysteroid dehydrogenase and, the second, by 7-hydroxysteroid dehydrogenase. Coenzyme regeneration was carried out with -ketoglutarate-glutamate dehydrogenase and glucose-glucose dehydrogenase, respectively. 相似文献
44.
Selenium,zinc, and thyroid hormones in healthy subjects 总被引:3,自引:0,他引:3
Oliviero Olivieri Domenico Girelli Anna Maria Stanzial Luigi Rossi Antonella Bassi Roberto Corrocher 《Biological trace element research》1996,51(1):31-41
Iodothyronine 5′ deiodinase, which is mainly responsible for peripheral T3 production, has recently been demonstrated to be a selenium (Se)-containing enzyme. The structure of nuclear thyroid hormone
receptors contains Zinc (Zn) ions, crucial for the functional properties of the protein. In the elderly, reduced peripheral
conversion of T4 to T3 with a lower T3/T4 ratio and overt hypothyroidism are frequently observed. We measured serum Se and RBC GSH-Px (as indices of Se status), circulating
and RBC Zinc (as indices of Zn status), thyroid hormones and TSH in 109 healthy euthyroid subjects (52 women, 57 men), carefully
selected to avoid abnormally low thyroid hormone levels induced by acute or chronic diseases or calorie restriction. The subjects
were subdivided into three age groups. To avoid under- or malnutrition conditions, dietary records were obtained for a sample
of 24 subjects, randomly selected and representative of the whole population for age and sex. Low T3/T4 ratios and reduced Se and RBC GSH-Px activity were observed only in the older group. A highly significant linear correlation
between the T3/T4 ratio and indices of Se status was observed in the older group of subjects (r=0.54;p<0.002, for Se;r=0.50;p<0.002, for RBC GSH-Px). Indices of Zn status did not correlate with thyroid hormones, but RBC Zn was decreased in older as
compared with younger subjects. We concluded that reduced peripheral T4 conversion is related to impaired Se status in the elderly. 相似文献
45.
Nicoletta La Rocca Roberto Barbato Giorgio Casadoro Nicoletta Rascio 《Physiologia plantarum》1996,96(3):513-518
The assimilatory activity of cotyledons can play an essential role in the survival of seedlings with a slow and delayed development of primary leaves. Changes in the photosynthetic activity of the cotyledon, from the onset of greening through senescence, were studied in two such plants, carob and sunflower, in order to determine its efficiency and duration, also in connection with the achievement of assimilatory autonomy by the plantlet. Chlorophyll analyses showed that the cotyledon's chloroplasts reached maximal greening in plantlets with a pair of expanded leaves. In contrast, the cotyledon's photosynthetic activity, measured as the rate of oxygen release, started to decrease early, before expansion of primary leaves. The decrease was due to the inactivation of a number of photosystem II (PSII) units, as revealed by immunodetection of breackdown products of the reaction centre's D1 and D2 thylakoid proteins. No signals of PSII alteration were noticed in the primary leaf chloroplasts that differentiated under the same environmental conditions. The damage to the cotyledon PSII, occurring in a non-photoinhibitory situation, might be due to a slower rate of turnover of D1 polypeptide than in the leaf thylakoids. The differential turnover of this protein in cotyledons and in leaves might represent an organ-specific regulation of the photosynthetic activity. The peculiarity of the cotyledon thylakoids make these organs useful objects for studying the metabolic cycle of both D1 and D2 proteins in vivo, under non-photoinhibiting conditions. 相似文献
46.
Roberto Viola 《Planta》1996,198(2):186-196
Metabolism of radiolabelled hexoses by discs excised from developing potato (Solanum tuberosum L.) tubers was been investigated in the presence of acid invertase to prevent accumulation of labelled sucrose in the bathing medium (Viola, 1996, Planta 198: 179–185). When the discs were incubated with either [U-14C]glucose or [U-14C]fructose without unlabelled hexoses, the unidirectional rate of sucrose synthesis was insignificant compared with that of sucrose breakdown. The inclusion of unlabelled fructose in the medium induced a dramatic increase in the unidirectional rate of sucroses synthesis in the tuber discs. Indeed, the decline in the sucrose content observed when discs were incubated without exogenous sugars could be completely prevented by including 300 mM fructose in the bathing medium. On the other hand, the inclusion of unlabelled glucose in the medium did not significantly affect the relative incorporation of [U-14C]glucose to starch, sucrose or glycolytic products. Substantial differences in the intramolecular distribution of 13C enrichment in the hexosyl moieties of sucrose were observed when the discs were incubated with either [2-13C]fructose or [2-13C]glucose. The pattern of 13C enrichment distribution in sucrose suggested that incoming glucose was converted into sucrose via the sucrose-phosphate synthase pathway whilst fructose was incorporated directly into sucrose via sucrose synthase. Quantitative estimations of metabolic fluxes in vivo in the discs were also provided. The apparent maximal rate of glucose phosphorylation was close to the extractable maximum catalytic activity of glucokinase. On the other hand, the apparent maximal rate of fructose phosphorylation was much lower than the maximum catalytic activity of fructokinase, suggesting that the activity of the enzyme (unlike that of glucokinase) was regulated in vivo. Although in the discs incubated with or without fructose the rates of starch synthesis or glycolysis were similar, the relative partitioning of metabolic intermediates into sucrose was much higher in discs incubated with fructose (0.6% and 32.6%, respectively). It is hypothesised that the equilibrium of the reaction catalysed by sucrose synthase in vivo is affected in discs incubated with fructose as a result of the accumulation of the sugar in the tissue. This results in the onset of sucrose cycling. Incubation with glucose enhanced all metabolic fluxes. In particular, the net rate of starch synthesis increased from 2.0 mol · hexose · g FW–1 · h–1 in the absence of exogenous glucose to 3.7 mol · hexose · g FW–1 · h–1 in the presence of 300 mM glucose. These data are taken as an indication that the regulation of fructokinase in vivo may represent a limiting factor in the utilisation of sucrose for biosynthetic processes in developing potato tubers.Abbreviations ADPGlc
adenosine 5-diphosphoglucose
- Glc6P
glucose-6-phosphate
- hexose-P
hexose phosphate
- NMR
nuclear magnetic resonance
- UDPGlc
uridine 5-diphosphoglucose
Many thanks to L. Sommerville for skillfull assistance and to J. Crawford and J. Liu for useful discussions on flux analysis. The research was funded by the Scottish Office Agriculture and Fisheries Department. 相似文献
47.
Transfer factor in chronic mucocutaneous candidiasis 总被引:3,自引:0,他引:3
Fifteen patients suffering from chronic mucocutaneous candidiasis were treated with an in vitro produced TF specific for Candida
albicans antigens and/or with TF extracted from pooled buffy coats of blood donors. CMI of the patients was assessed using
the LMT and the LST in presence of candidine. The aim of the study was the clinical evaluation of TF treatment and the incidence
of positive tests before, during, and after therapy. Immunological data were matched using the Chi square test. 87 LMT were
performed for each antigen dose and at the dilution of 1/50, 58.9% (33/56) tests were positive during non-treatment or non-specific
TF treatment. On the contrary 83.9% (26/31) were positive during specific TF treatment (P<0.05). In the LST, a significant
decrease of thymidine uptake in the control cultures in presence of autologous or AB serum was observed when patients were
matched according to non-treatment, and both non specific (P<0.05) and specific TF treatment (P<0.01). Only during specific
TF treatment was a significant increase of reactivity against the Candida antigen at the highest concentration noticed, when
compared with the period of non specific treatment (P<0.01). Clinical observations were encouraging: all but one patient experienced
significant improvement during treatment with specific TF. These data confirm that orally administered specific TF, extracted
from induced lymphoblastoid cell-lines, increases the incidence of reactivity against Candida antigens in the LMT. LST reactivity
appeared not significantly increased with respect to the periods of non treatment, but was significantly increased when it
was compared to the non-specific TF treatment periods. At the same time, a clinical improvement was noticed. 相似文献
48.
Roberto E. Izquierdo Kimberly Breese Shalini Jain Daniel Carestio Lawrence Jung James Figge 《In vitro cellular & developmental biology. Animal》1995,31(1):71-76
Summary Gene transfer techniques can be used to encode the production of a polypeptide product, such as human growth hormone (hGH),
that is missing in an acquired or inherited disease state such as growth hormone deficiency. In one model system, engineered
C2C12 myoblasts are injected intramuscularly into a mouse and subsequently secrete hGH into the circulation. In this regard,
a gene-expression regulatory system that functions in myoblasts would be of interest. We demonstrate that theEscherichia coli lac operon system can be used to stringently regulate the expression of hGH in engineered C2C12 myoblasts in tissue culture.
A DNA segment encoding hGH was linked to a DNA segment containing an SV40 enhancer and promoter. The latter components were
positioned between two syntheticlac operators.Lac repressor expression was driven by a simian cytomegalovirus promoter. In transient co-transfection assays, hGH expression
from cultured C2C12 myoblasts could be modulated up to 60-fold (P = 0.002) with the inducing agent, isopropyl-β-d-thiogalactoside (IPTG). In the absence of IPTG, hGH expression was almost fully repressed. These results show that the components
of theE. coli lac operon provide a stringent regulatory system for use in myoblasts. The system might prove to be useful for the regulation
of transferred genes in animals. 相似文献
49.
Roberto MacChiarelli Luca Bondioli Laura Censi Margarita Kristoff Hernaez Loretana Salvadei Alessandra Sperduti 《American journal of physical anthropology》1994,95(1):77-83
Little attention has been devoted to assessing the reproducibility of (paleo)pathological observations. Harris lines (HL) are among the markers most used to determine chronology of stresses suffered during growth. Nevertheless, their scoring entails remarkable methodological difficulty. Bone sections (S) and radiographs (R) of 29 adult tibiae of archeological provenance (medieval) were scored for HL by five observers. At regular intervals of time, each observer gave two independent counts on both series. Results show a) a substantial interobserver disagreement of HL estimates for both sectional and radiographic records, and b) a high level of intraobserver error. © 1994 Wiley-Liss, Inc. 相似文献
50.
Silvia Sartoris Andrea De Lerma Barbaro Tiziana Cestari Giuseppe Tridente Roberto S. Accolla 《Immunogenetics》1994,39(1):8-14
RJ 2.2.5 is a human B cell mutant, derived from Raji cells, which has lost expression of major histocompatibility complex (MHC) class II genes because of a defect in the AIR1 locus function. The MHC class II-positive phenotype can be restored by introducing an active AIR1 locus or its mouse equivalent, Air-1. An example of the latter is the H4 cell hybrid, derived by somatic cell fusion between RJ 2.2.5 and mouse class II-positive spleen cells. H4 contains a single mouse chromosome, autosome 16, in which the Air-1 locus maps, and an entire RJ 2.2.5-derived genome. In the present study we show that the physiologic target of the Air-1 locus product is contained within a limited HLA-DRA promoter sequence of 300 base pairs, encompassing the crucial Y, X, and W cis-acting elements. A plasmid construct, pDRA300neo, containing the HLA-DRA promoter sequence which drives the expression of the neomycin resistance gene, has been stably integrated in the genome of the H4 hybrid. Transfectants selected in the presence of G418 retain mouse chromosome 16 and express the DR genes. On the other hand, transfectants grown in a non-selective medium segregate mouse chromosome 16; this is accompanied by a loss of DRA gene expression and G418 resistance, although pDRA300neo is still integrated in the genome. These results offer scope for using this experimental model to clone the Air-1 gene in a straightforward way.
Correspondence to: R. S. Accolla. 相似文献