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81.
Lack of a co-promoting effect of a 60 Hz magnetic field on skin tumorigenesis in SENCAR mice 总被引:4,自引:3,他引:1
Sasser LB; Anderson LE; Morris JE; Miller DL; Walborg EF Jr; Kavet R; Johnston DA; DiGiovanni J 《Carcinogenesis》1998,19(9):1617-1621
It has been proposed that extremely low frequency (ELF) magnetic fields may
enhance tumorigenesis through a co-promotional mechanism. This hypothesis
has been further tested using the two-stage model of mouse skin
carcinogenesis, i.e. 12-O-tetradecanoylphorbol-13-acetate (TPA)- induced
promotion of skin tumors in mice initiated by a single subcarcinogenic dose
of 7,12-dimethylbenz[a]anthracene. Experimentation described herein
utilized the SENCAR mouse and examined the effect of a magnetic field on
skin tumor promotion induced by three different doses of TPA within its
dose-response range, i.e. 0.85, 1.70 or 3.40 nmol, administered twice per
week. SENCAR mice (56/treatment group) were exposed to a 60 Hz magnetic
field having a flux density of 2 mT for 6 h/day for 5 days/week and
compared with mice exposed to the ambient magnetic field. Tumor incidence
and multiplicity were monitored weekly for 23 weeks of TPA promotion.
Statistical evaluation of the effects of the magnetic field on tumor
incidence and multiplicity did not reveal any statistically significant
effects; thus, within the sensitivity limits imposed by the animal model
and the exposure parameters employed, no promotional or co-promotional
effect of a 2 mT magnetic field on skin tumor development in SENCAR mice
could be demonstrated.
相似文献
82.
Increased colonic wall thickness has been reported in patients exposed to large doses of high strength pancreatic enzyme preparations who did not develop fibrosing colonopathy. This has been interpreted as evidence for a spectrum of subclinical disease. The relation between sonographically measured colonic wall thickness and pancreatic enzyme preparation and dose was studied in 86 children with cystic fibrosis (CF). Colonic wall thickness of a control group was also measured. The average thickness in all colonic regions was higher in the CF group (overall average range 0.7-2.5 mm v 0.6-1.4 mm in the control group). There was no significant relation between colonic wall thickness and age, sex, total dose of lipase, or copolymer. Apart from one patient with an early colonic stricture, none of those exposed to high doses of lipase, or the methacrylic acid copolymer Eudragit L30 D55, showed evidence of subclinical damage to the colon. The reproducibility of the sonographic measurements was poor. 相似文献
83.
84.
Responsiveness to cholinesterase inhibitors in Alzheimer's disease: a possible role for the 192 Q/R polymorphism of the PON-1 gene 总被引:6,自引:0,他引:6
Pola R Flex A Ciaburri M Rovella E Valiani A Reali G Silveri MC Bernabei R 《Neuroscience letters》2005,382(3):338-341
Cholinesterase inhibitors (ChEIs) are the most established treatment strategy in Alzheimer's disease (AD). However, the responsiveness to these drugs is widely heterogeneous and the majority of AD subjects do not respond to treatment. Paraoxonase-1 (PON-1) is a potent endogenous ChEI and has been widely studied for its ability to hydrolyze environmental neurotoxins. Serum levels and biological activity of PON-1 display wide inter-individual variability and are strongly influenced by a common polymorphism at position 192 of the PON-1 gene. Here, we evaluated whether this gene variation is associated with differences in the ability of AD subjects to respond to therapy with ChEIs. We found that individuals that respond to ChEIs had a significantly higher frequency of the R allele, compared to non-responders (P<0.05). This study indicates that the 192 Q/R polymorphism of the PON-1 gene might influence responsiveness to ChEIs, with potentially important implications for the treatment of AD. Mutations of genes encoding for endogenous modulators of the cholinergic system should merit further investigation as prognostic indicators of individual response to treatment in AD subjects. 相似文献
85.
Inducible nitric oxide synthase expression in benign and malignant cutaneous melanocytic lesions 总被引:8,自引:0,他引:8
Massi D Franchi A Sardi I Magnelli L Paglierani M Borgognoni L Maria Reali U Santucci M 《The Journal of pathology》2001,194(2):194-200
Nitric oxide (NO) is synthesized by nitric oxide synthases (NOS) and plays an important role in tumour growth. In this study, inducible NOS (iNOS) expression was evaluated by immunohistochemistry in 34 melanocytic naevi (13 common melanocytic naevi, six Spitz naevi, and 15 so-called 'dysplastic naevi'), ten cutaneous melanomas in situ, 50 stage I invasive melanomas, and eight subcutaneous metastases of melanoma. In addition, four samples of melanocytic naevi and four samples of invasive melanomas were collected in order to perform western blot and northern blot analysis. By immunohistochemistry, melanocytic naevi never expressed iNOS. Among cases of melanoma in situ, two were negative, seven displayed staining in less than 20% of melanoma cells, and positivity was observed in 21-50% of melanoma cells in only one case. iNOS expression was detected in 46 out of 50 invasive melanomas (92%). Among these cases, 18 showed positivity in less than 20% of melanoma cells, 18 showed positivity in 21-50% of melanoma cells, and ten showed iNOS expression in more than 50% of cells. Statistical analysis revealed a significant difference in iNOS expression between melanocytic naevi and cutaneous melanomas (p<0.001). In addition, iNOS expression was significantly higher in invasive melanomas than in melanomas in situ (p=0.01). Among primary cutaneous melanomas, no significant correlation was found between iNOS expression and histopathological parameters (histotype, level, thickness and presence of regression/inflammatory infiltrate) and disease-specific survival. In subcutaneous melanoma metastases, iNOS expression was diffuse in more than 50% of cells. Statistical analysis revealed that subcutaneous melanoma metastases showed greater iNOS immunoreactivity than invasive melanomas (p=0.02). Molecular analyses confirmed that iNOS mRNA and protein were highly expressed in melanoma samples. In conclusion, iNOS was constantly absent in melanocytic naevi, whereas it was frequently expressed in melanomas, with up-regulation of the enzyme paralleling tumour progression. These data suggest that iNOS may play a role in the malignant transformation of melanocytes and in tumour growth. In addition, iNOS may be useful as an immunohistochemical marker for malignant melanocytic lesions. 相似文献
86.
G Orlandini S Bernasconi L Zannino F Bacciottini E Frezza N Reali A Casti 《Early human development》1987,15(6):323-327
Polyamines were detected in the blood of infants during the first six months of life. The highest spermidine levels were found at the 2nd and the 4th month after birth. Spermine, on the contrary, does not show significant differences. Different types of diet produced no changes in the polyamine pattern. 相似文献
87.
E Reali J W Greiner A Corti H J Gould F Bottazzoli G Paganelli J Schlom A G Siccardi 《Cancer research》2001,61(14):5517-5522
Surface-bound IgE play a central role in antiparasite immunity; to exploit IgE-driven immune mechanisms in tumor prevention and control, monoclonal IgEs of irrelevant specificity were loaded through biotin-avidin bridging onto tumor cells, either by systemic administration to tumor-bearing mice or pre-loading of tumor cells before inoculation. Here we show that systemic administration of biotinylated IgEs to mice bearing tumors pre-targeted with biotinylated antibodies and avidin significantly decreased tumor growth rate. In addition, as compared with IgG-loaded control cells, inoculation of suboptimal doses of IgE-loaded tumor cells suppressed tumor formation in a fraction of animals and induced protective host immunity by eliciting tumor-specific T-cell responses. Similarly, tumor vaccination experiments showed that irradiated tumor cells (IgE loaded by biotin-avidin bridging) conferred protective immunity at doses 100-fold lower than the corresponding control cells without IgE. Finally, in vivo depletion of eosinophils or T cells abrogated IgE-driven tumor growth inhibition. These results demonstrate that IgEs targeted on tumor cells not only possess a curative potential but also confer long-term antitumor immunity and that IgE-driven antitumor activity is not restricted to the activation of innate immunity effector mechanisms but also results from eosinophil-dependent priming of a T-cell-mediated adaptive immune response. This suggests a potential role for IgEs in the design of new cell-based tumor vaccines. 相似文献
88.
Lung inflammation in preterm infants with respiratory distress syndrome: effects of ventilation with different tidal volumes 总被引:1,自引:0,他引:1
Lista G Castoldi F Fontana P Reali R Reggiani A Bianchi S Compagnoni G 《Pediatric pulmonology》2006,41(4):357-363
Ventilation with an inappropriate tidal volume (Vt) triggers lung inflammation, an important predisposing factor of bronchopulmonary dysplasia. It still remains uncertain what the appropriate starting target Vt should be during the acute phase of respiratory distress syndrome (RDS). Our aim was to evaluate lung inflammation in preterm infants undergoing synchronized intermittent positive-pressure ventilation (SIPPV) with two different tidal volumes Vt during the acute phase of RDS. Thirty preterm infants (gestational age, 25-32 weeks) with acute RDS were randomly assigned to be ventilated with Vt = 5 ml/kg (n = 15) or Vt = 3 ml/kg (n = 15). Proinflammatory cytokines (interleukin-6 (IL-6), interleukin-8 (IL-8), and tumor necrosis factor (TNF)-alpha) were determined in the tracheal aspirate on days 1, 3, and 7 of life. IL-8 and TNF-alpha levels collected on day 7 were significantly higher (P < 0.05), and mechanical ventilation lasted longer in the group with Vt = 3 ml/kg (16.8 +/- 4 vs. 9.2 +/- 4 days; P = 0.05). In conclusion, our data show significantly higher lung inflammation in preterm infants ventilated with Vt = 3 ml/kg, suggesting a role for Vt = 5 ml/kg in reducing both inflammatory response during the acute phase of RDS and the length of ventilation. Whether the use of this starting Vt prevents bronchopulmonary dysplasia requires further study. 相似文献
89.
EF Druyts B Yip VD Lima TA Burke D Lesovski KA Fernandes CW McInnes CA Rustad JSG Montaner RS Hogg 《HIV medicine》2009,10(2):88-93
Objective
The aim of the study was to determine rates of utilization of in‐patient, out‐patient and laboratory services stratified by virological and immunological markers of HIV disease among patients on antiretroviral treatment in British Columbia, Canada.Methods
We estimated resource utilization for in‐patient visits, out‐patient visits, and laboratory tests among patients initiating antiretroviral treatment between 1 April 1994 and 31 December 2000, with follow‐up to 31 March 2001. Resource use was stratified by CD4 cell count and plasma HIV viral load (pVL) at the time of utilization and rates per 100 patient‐years were calculated for each health care resource.Results
A total of 2718 patients were included in our analyses. The overall rates of in‐patient visits, out‐patient visits, and laboratory tests were 902, 3001 and 840 per 100 patient‐years, respectively. Utilization was higher for patients with low CD4 cell counts and high pVLs when compared with patients with high CD4 cell counts and low pVLs.Conclusions
Patients with low CD4 cell counts and high pVLs had the highest use of health care services. Regular follow‐up with health care providers in an out‐patient setting, allowing for proper monitoring and maintenance of HIV care, is important in minimizing unnecessary and potentially costly in‐patient care. 相似文献90.
Purging leukemic cells from simulated human remission marrow with alkyl- lysophospholipid 总被引:2,自引:0,他引:2
Alkyl-lysophospholipids (ALP) are analogues of 2- lysophosphatidylcholine that have been reported to have selective antitumor activity. These compounds could potentially be useful in purging bone marrow of leukemic cells in autologous marrow transplantation in acute leukemia. To determine the efficacy of pharmacological purging by ALP, we have designed a human assay system to mimic the conditions expected in the clinical setting of autotransplantation using remission marrow. A simulated remission marrow (SRM) was prepared by mixing normal marrow cells and HL60 cells in a ratio of 1,000:1. The effect of cryopreservation on ALP-treated normal, HL60, and SRM cells was examined. In separate experiments, ALP significantly reduced the number of clonogenic HL60 cells with no effect on normal marrow progenitors. The effect of ALP was more apparent after cryopreservation. Incubation of HL60 cells with 50 micrograms/mL ALP for four hours followed by cryopreservation resulted approximately in a 3 log reduction of clonogenic HL60 cells. ALP also selectively purged the small number of leukemic cells from SRM. In SRM, the data suggested that ALP had indirect cytotoxic activity on leukemic cells by enhancing the cytotoxic activity of monocytes in addition to its direct effect. We found no evidence that clonogenic HL60 cells decreased because of induction of differentiation by ALP. These data indicated that treatment of marrow cells with ALP offers an efficient means to eliminate leukemic cells from the graft. 相似文献