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71.
Ultrastructure of the female gonad of two temnocephalids (Platyhelminthes,Rhabdocoela) 总被引:2,自引:2,他引:0
The female gonad of Temnocephala dendyi and T. minor consists of a single germarium and two rows of vitellaria. It is enveloped
by an extracellular lamina and accessory cells. Accessory cells are only peripherally located in the germarium while their
cytoplasmic projections also fill the spaces between vitellocytes in the vitellarium. The main feature of oocyte maturation
is the appearance of chromatoid bodies and the development of rough endoplasmic reticulum (R.E.R.) and Golgi complexes which
appear to be correlated with the production of double-structured egg granules. The egg granules, which are localized in the
cortical cytoplasm of mature oocytes, contain glycoproteins, are devoid of polyphenols and are similar in structure and composition
to the cortical granules observed in some Digenea and Monogenea. Vitellocytes are typical secretory cells with well-developed
R.E.R. and Golgi complexes which are involved in the production of shell globules and yolk. The multigranular pattern and
the polyphenolic composition of the shell globules of the temnocephalids investigated are similar to those observed in other
rhabdocoels, and in some Prolecithophora and Neodermata. This feature may represent a synapomorphy shared by these taxa.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
72.
73.
Marilena Monica Vece Claudia Agnoli Sara Grioni Sabina Sieri Valeria Pala Nicoletta Pellegrini Graziella Frasca Rosario Tumino Amalia Mattiello Salvatore Panico Benedetta Bendinelli Giovanna Masala Fulvio Ricceri Carlotta Sacerdote Vittorio Krogh 《PloS one》2015,10(11)
Background
Colorectal cancer is the third most common cancer worldwide. Diet has been hypothesized as involved in colorectal cancer etiology, but few studies on the influence of total dietary antioxidant intake on colorectal cancer risk have been performed.Methods
We investigated the association between colorectal cancer risk and the total antioxidant capacity (TAC) of the diet, and also of intake of selected antioxidants, in 45,194 persons enrolled in 5 centers (Florence, Naples, Ragusa, Turin and Varese) of the European Prospective Investigation into Cancer and Nutrition (EPIC) Italy study. TAC was estimated by the Trolox equivalent antioxidant capacity (TEAC) assay. Hazard ratios (HRs) for developing colorectal cancer, and colon and rectal cancers separately, adjusted for confounders, were estimated for tertiles of TAC by Cox modeling, stratifying by center.Results
Four hundred thirty-six colorectal cancers were diagnosed over a mean follow-up of 11.28 years. No significant association between dietary TAC and colorectal cancer incidence was found. However for the highest category of TAC compared to the lowest, risk of developing colon cancer was lower (HR: 0.63; 95% CI: 0.44–0.89, P trend: 0.008). By contrast, increasing TAC intake was associated with significantly increasing risks of rectal cancer (2nd tertile HR: 2.09; 95%CI: 1.19–3.66; 3rd tertile 2.48 95%CI: 1.32–4.66; P trend 0.007). Intakes of vitamin C, vitamin E, and ß-carotene were not significantly associated with colorectal cancer risk.Conclusions
Further prospective studies are needed to confirm the contrasting effects of high total antioxidant intake on risk of colon and rectal cancers. 相似文献74.
75.
It has been demonstrated that patients showing symptoms of chronic bacterial prostatitis but culture-negative prostate-specific specimens can benefit from administration of antibacterial agents. This suggests that organisms that are not isolated in the routine practice may be responsible for prostate infection in an undefined fraction of subjects. Anaerobic bacteria have been proposed to play a pathogenic role in CBP, on the basis of studies describing clinical remission after eradication of pathogens like Peptostreptococcus spp or Bacterioides spp from prostatic secretions of symptomatic patients, or the significant association between prostatic infection by anaerobes and the presence of inflammation markers in prostatic secretions.In this paper, we report in detail a case of severely symptomatic chronic prostatitis in a patient with evidence of infection by Peptostreptococcus. We also report for the first time that treatment with the 3rd generation fluoroquinolone moxifloxacin was successful in eradicating the pathogen and in causing dramatic resolution of signs and symptoms of chronic bacterial prostatitis.The strict association between eradication of Peptostreptococcus and the rapid disappearance of clinical signs/symptoms points to a causative role of this anaerobe in the chronic bacterial prostatitis case described in this report. 相似文献
76.
Carbapenem-resistant gram-negative pathogens represent an emerging threat to the management of hospital-acquired infections. Although the isolation of carbapenem-resistant enterobacteriaceae remains unusual, the frequency of carbapenemases producing Klebsiella pneumoniae is increasing in different geographic regions: the majority of isolates has been collected in the USA, but recently KPC-producing K. pneumoniae were reported from China, Israel, Greece, France, Norway and Sweden. We report a KPC 1-producing K. pneumoniae isolate from Italy. This datum enlarges the geographical area where the KPC-producing K. pneumoniae strains are diffuse. 相似文献
77.
Maria Filippa Addis Roberto Cappuccinelli Vittorio Tedde Daniela Pagnozzi Iolanda Viale Mauro Meloni Fulvio Salati Tonina Roggio Sergio Uzzau 《Proteome science》2010,8(1):50
Background
Currently, presence of Moraxella sp. in internal organs of fish is not considered detrimental for fish farming. However, bacterial colonization of internal organs can affect fish wellness and decrease growth rate, stress resistance, and immune response. Recently, there have been reports by farmers concerning slow growth, poor feed conversion, and low average weight increase of fish farmed in offshore floating sea cages, often associated with internal organ colonization by Moraxella sp. Therefore, presence of these opportunistic bacteria deserves further investigations for elucidating incidence and impact on fish metabolism. 相似文献78.
79.
Devescovi G Bigirimana J Degrassi G Cabrio L LiPuma JJ Kim J Hwang I Venturi V 《Applied and environmental microbiology》2007,73(15):4950-4958
Burkholderia glumae is an emerging rice pathogen in several areas around the world. Closely related Burkholderia species are important opportunistic human pathogens for specific groups of patients, such as patients with cystic fibrosis and patients with chronic granulomatous disease. Here we report that the first clinical isolate of B. glumae, strain AU6208, has retained its capability to be very pathogenic to rice. As previously reported for rice isolate B. glumae BGR1 (and also for the clinical isolate AU6208), TofI or TofR acyl homoserine lactone (AHL) quorum sensing played a pivotal role in rice virulence. We report that AHL quorum sensing in B. glumae AU6208 regulates secreted LipA lipase and toxoflavin, the phytotoxin produced by B. glumae. B. glumae AU6208 lipA mutants were no longer pathogenic to rice, indicating that the lipase is an important virulence factor. It was also established that type strain B. glumae ATCC 33617 did not produce toxoflavin and lipase and was nonpathogenic to rice. It was determined that in strain ATCC 33617 the LuxR family quorum-sensing sensor/regulator TofR was inactive. Introducing the tofR gene of B. glumae AU6208 in strain ATCC 33617 restored its ability to produce toxoflavin and the LipA lipase. This study extends the role of AHL quorum sensing in rice pathogenicity through the regulation of a lipase which was demonstrated to be a virulence factor. It is the first report of a clinical B. glumae isolate retaining strong rice pathogenicity and finally determined that B. glumae can undergo phenotypic conversion through a spontaneous mutation in the tofR regulator. 相似文献
80.
Calabrese V Mancuso C Ravagna A Perluigi M Cini C De Marco C Butterfield DA Stella AM 《Journal of neurochemistry》2007,101(3):709-717
Increasing evidence suggests a critical role for oxidative and nitrosative stress in the pathogenesis of most important neurodegenerative disorders. Parkinson's disease (PD) is a neurodegenerative disease characterized by a severe depletion in number of dopaminergic cells of the substantia nigra (SN). Administration of L-DOPA (LD) is the more effective treatment for patients with PD. However, the vast majority of patients suffer LD-related complications, which represent the major problem in the clinical management of PD. In the present study, LD administration to rats resulted in a significant dose-dependent increase in Hsp70 synthesis which was specific for the SN. The amount of 70 kDa protein increased after 6 h treatment reaching the maximal induction after 24-48 h. Induction of Hsp70 in the SN was associated with a significant increase in constitutive Hsc70 and mitochondrial Hsp60 stress proteins, and with increased expression of mitochondrial complex I whereas no significant changes were found in the activity of complex IV. In the same experimental conditions, a significant decrease in reduced glutathione was observed, which was associated with an increased content of oxidized glutathione content as well as nitric oxide (NO) synthase activity, NO metabolites and nitrotyrosine immunoreactivity. Interestingly, Hsp70 induction, iNOS up-regulation and nitrotyrosine formation have been confirmed also in SN and striatum of rats treated with LD and carbidopa, this latter being an inhibitor of the peripheral DOPA decarboxylase. Our data are in favor of the importance of the heat shock signal pathway as a basic mechanism of defense against neurotoxicity elicited by free radical oxygen and nitrogen species produced in aging and neurodegenerative disorders. 相似文献