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排序方式: 共有504条查询结果,搜索用时 15 毫秒
1.
Zuccala G.; Pahor M.; Lattanzio F.; Vagnoni S.; Rodola F.; De Sole P.; Cittadini A.; Cocchi A.; Bernabei R. 《British journal of anaesthesia》1997,79(6):776-781
The use of high-dose magnesium infusions in critically ill and surgical
patients is increasing. This practice is associated with considerable risk
of toxicity, as no reliable criteria are currently available to detect
significant intracellular magnesium depletion. We have evaluated, before
and after surgery, 33 elderly patients with hip fracture, by 24-h Holter
ECG monitoring, Doppler echocardiography and serum chemistry; lymphocyte
magnesium was measured using atomic absorption spectrophotometry. The
severity of ventricular arrhythmias increased, and serum and mononuclear
magnesium concentrations decreased significantly after surgery. Decreases
in either serum magnesium concentrations > 0.125 mmol litre-1 or
cellular magnesium > 6 nmol mg- 1, but not serum or lymphocyte absolute
magnesium concentrations, were associated with postoperative development of
repetitive arrhythmias. Variations in serum magnesium concentrations
correlated with intracellular decreases, and yielded good accuracy in
predicting the postoperative worsening of arrhythmias. Thus perioperative
differences in serum magnesium concentrations reflected intracellular
variations and allowed us to identify patients with clinically relevant
cellular magnesium depletion.
相似文献
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Puntoni Riccardo; Toninelli Fabrizia; Zhankui Li; Bonassi Stefano 《Carcinogenesis》1995,16(7):1465-1471
The existence of a dose-related increase of lung cancer riskin cigarette smokers has been indisputably established. Thisfinding, however, is not confirmed at low doses (< 5 cigarettes/day),there still being a lack of epidemiological data. The use ofmathematical models of carcinogenesis to extrapolate from higherdoses allows estimation of the risk for very light smokers.The present study has been designed to compare a set of mathematicalmodels, i.e. one-hit, two-stage, multi-stage, logit, probit,and Weibull, in extrapolating relative risks at low doses fromthe data of nine large cohort studies on cigarette smokers reportedin the IARC Scientific Monograph on tobacco smoking. All modelsevaluated, apart from the one-hit, achieved a good fit, withthe proportion of explained variance ranging between 61% and67%. The relative risk estimates for passive smokers from themost updated epidemiological studies were taken into accountto evaluate, on the basis of these models, the correspondingexposure in terms of cigarette equivalent smoked.These values ranged from 0.21 to 0.43 cigarettes/day for thetwo-stage and multistage model, while probit, logit and Weibullmodels, yielded estimates one or even two orders of magnitudelower. The authors emphasize the substantial agreement betweenthe estimates of cigarette equivalent9 based on the applicationof two-stage and multi-stage models to the epidemiological evidenceon the effect of passive smoking and to the data based on thecomparison of tobacco metabolites in active and passive smokers. 相似文献
4.
Aesthetic outcome of immediately restored single implants placed in extraction sockets and healed sites of the anterior maxilla: a retrospective study on 103 patients with 3 years of follow‐up 下载免费PDF全文
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Luísa C. S. Antunes Francesco Imperi Fabrizia Minandri Paolo Visca 《Antimicrobial agents and chemotherapy》2012,56(11):5961-5970
Multidrug-resistant Acinetobacter baumannii poses a tremendous challenge to traditional antibiotic therapy. Due to the crucial role of iron in bacterial physiology and pathogenicity, we investigated iron metabolism as a possible target for anti-A. baumannii chemotherapy using gallium as an iron mimetic. Due to chemical similarity, gallium competes with iron for binding to several redox enzymes, thereby interfering with a number of essential biological reactions. We found that Ga(NO3)3, the active component of an FDA-approved drug (Ganite), inhibits the growth of a collection of 58 A. baumannii strains in both chemically defined medium and human serum, at concentrations ranging from 2 to 80 μM and from 4 to 64 μM, respectively. Ga(NO3)3 delayed the entry of A. baumannii into the exponential phase and drastically reduced bacterial growth rates. Ga(NO3)3 activity was strongly dependent on iron availability in the culture medium, though the mechanism of growth inhibition was independent of dysregulation of gene expression controlled by the ferric uptake regulator Fur. Ga(NO3)3 also protected Galleria mellonella larvae from lethal A. baumannii infection, with survival rates of ≥75%. At therapeutic concentrations for humans (28 μM plasma levels), Ga(NO3)3 inhibited the growth in human serum of 76% of the multidrug-resistant A. baumannii isolates tested by ≥90%, raising expectations on the therapeutic potential of gallium for the treatment of A. baumannii bloodstream infections. Ga(NO3)3 also showed strong synergism with colistin, suggesting that a colistin-gallium combination holds promise as a last-resort therapy for infections caused by pan-resistant A. baumannii. 相似文献
7.
Alberto Montesanto Francesco De Rango Maurizio Berardelli Vincenzo Mari Fabrizia Lattanzio Giuseppe Passarino Andrea Corsonello 《Age (Dordrecht, Netherlands)》2014,36(3):1503-1514
The equations for estimating kidney function have become very popular in the last decade. However, the clinical and prognostic meaning of these measures may be very different in older populations. Two cohorts of people aged 65–89 years (older sample) and 90 or more (oldest old sample) were used to investigate the prognostic significance of estimated glomerular filtration rate (eGFR). Additionally, we also investigated whether combining frailty and eGFR may improve the accuracy of frailty in predicting mortality. We found that lower eGFR values were significantly more frequent among frail subjects in both groups. eGFR < 30 was associated with increased risk for all-cause mortality either in subjects aged 65–89 years (HR = 3.71, 95% CI = 1.23–11.2) or in those aged 90 or more (HR = 1.53, 95% CI = 1.05–2.23). In the latter group, a not significant trend for increasing mortality was also observed among people with eGFR > 60 (HR = 1.28, 95% CI = 0.72–2.26). In addition, the oldest old subjects with eGFR > 60 and eGFR < 30 had the lowest hand-grip strength and ADL values. Combining eGFR and frailty status significantly improved the accuracy of frailty in predicting mortality only in the older sample. In conclusion, a U-shaped relationship exists between eGFR and mortality in the oldest old, but not in older individuals. Our findings suggest that eGFR needs to be adjusted for muscle mass/physical performance when estimating kidney function in people aged 90 or more. Nevertheless, in subjects aged 65–89 years, eGFR may improve the accuracy of frailty status in predicting prognosis, thus suggesting that eGFR may represent an additional dimension of frailty syndrome. 相似文献
8.
Fabrizia Fabrizi de Biani Annalisa Reale Vincenzo Razzano Marco Paolino Germano Giuliani Alessandro Donati Gianluca Giorgi Wojciech Mrz Daniele Piovani Chiara Botta Andrea Cappelli 《RSC advances》2018,8(20):10836
The electrochemical behavior of some polybenzofulvene derivatives bearing bithiophene (BT) or terthiophene (TT) side chains was investigated by cyclic voltammetry. Very interestingly, the presence of unsubstituted terminal thiophene moieties allowed poly-6-BT-BF3k and poly-6-TT-BF3k to be cross-linked by electrochemical procedures. Conductive films were obtained by electrodeposition from solutions of these polymers onto electrode surfaces through the formation of covalent cross-linking due to dimerization (i.e. electrochemical oxidation) of the BT or TT side chains. The films showed electrochromic features and switched from yellow-orange (neutral) to green (positively charged) by switching the potential, and were stable to tenths of cycles, without degradation in the wet state in the electrolyte solution. Finally, the thin film obtained by electrodeposition of poly-6-TT-BF3k on a indium tin oxide (ITO) glass substrate showed in the neutral state a significantly red-shifted photoluminescence (PL) emission (∼40 nm red-shifted with respect to that of the corresponding film obtained by casting procedures), which was consistent with the presence of more conjugated moieties produced by the oxidative dimerization of the TT side chains. The innovative architecture and the easy preparation could lead to a broad range of applications in optoelectronics and bioelectronics for these cross-linked hybrid materials based on π-stacked polybenzofulvene backbones bearing oligothiophene side chains.The electrochemical behavior of some polybenzofulvene derivatives bearing bithiophene (BT) or terthiophene (TT) side chains was investigated by cyclic voltammetry and cross-linked materials were obtained by dimerization of the BT or TT side chains. 相似文献
9.
This study was designed to determine levels of NF-κB reporter gene activity and free radical generation in cultured striated
myocytes (H9C2 cells) exposed to cocaine or morphine in the presence of free radical scavengers. Cells were transiently transfected
with a NF-κB reporter gene and changes in luciferase activity were detected, by bioluminescence. Using confocal microscopy
and 2′,7′-dichlorofluorescin diacetate, cocaine-induced or morphine-induced free radicals were quantified in H9C2 cells. Cocaine
and morphine (0–1×10−2
M) were tested separately. Cocaine but not morphine significantly activated Nf-κB reporter gene, activity in H9C2 cells. Overexpression
of IκB inhibited NF-κB reporter activity at low (1×10−4
M) but not high (1×10−2
M) cocaine concentrations. Free radicals were generated in H9C2 cells stimulated with cocaine but not with morphine. The production
of free radicals and NF-κB reporter gene activity could be blocked with N-acetylcysteine, glutathione, and to a lesser extent, lipoic acid. The results suggest that cocaine induces free radical production,
which leads to the activation of NF-κB signal transduction and possible inflammatory responses. 相似文献
10.
G. de Stasio M. Canavaggio L. Rizzi A. Lattanzio M. Lancieri F. D''Erasmo A. Colapietro S. Barbuti M. Quarto V. Liso G. Specchia G. Pastore L. Schreiber and H. Lee 《Vox sanguinis》1990,59(3):167-171
A stringent procedure for the diagnosis of human T-lymphotropic virus (HTLV) infection was applied to 1,732 volunteer blood donors, 401 patients with various hematological disorders and 78 individuals at high risk for HIV infection. It consisted of a viral lysate-based screening assay (Abbott Laboratories, North Chicago, Ill., USA), and two confirmatory assays (Western blot and radioimmunoprecipitation assay). A confirmed positive sample had to react with at least two different HTLV gene products. Evidence of HTLV infection was not found in either blood donors or patients with hematological disorders. In fact, HTLV infection was only observed in 10 intravenous drug abusers or their sexual partners. Contrary to previous reports that claimed HTLV seroprevalences of between 0.3 and 8% in blood donors from Apulia (Italy), our data suggest that infection with this virus is principally restricted to intravenous drug abusers. 相似文献