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121.
Branched chain amino acids induce apoptosis in neural cells without mitochondrial membrane depolarization or cytochrome c release: implications for neurological impairment associated with maple syrup urine disease 总被引:6,自引:0,他引:6
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Jouvet P Rustin P Taylor DL Pocock JM Felderhoff-Mueser U Mazarakis ND Sarraf C Joashi U Kozma M Greenwood K Edwards AD Mehmet H 《Molecular biology of the cell》2000,11(5):1919-1932
Maple syrup urine disease (MSUD) is an inborn error of metabolism caused by a deficiency in branched chain alpha-keto acid dehydrogenase that can result in neurodegenerative sequelae in human infants. In the present study, increased concentrations of MSUD metabolites, in particular alpha-keto isocaproic acid, specifically induced apoptosis in glial and neuronal cells in culture. Apoptosis was associated with a reduction in cell respiration but without impairment of respiratory chain function, without early changes in mitochondrial membrane potential and without cytochrome c release into the cytosol. Significantly, alpha-keto isocaproic acid also triggered neuronal apoptosis in vivo after intracerebral injection into the developing rat brain. These findings suggest that MSUD neurodegeneration may result, at least in part, from an accumulation of branched chain amino acids and their alpha-keto acid derivatives that trigger apoptosis through a cytochrome c-independent pathway. 相似文献
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ISABELLE DE CAUWER MATHILDE DUFAY JOËL CUGUEN JEAN‐FRANÇOIS ARNAUD 《Molecular ecology》2010,19(8):1540-1558
Plant mating systems are known to influence population genetic structure because pollen and seed dispersal are often spatially restricted. However, the reciprocal outcomes of population structure on the dynamics of polymorphic mating systems have received little attention. In gynodioecious sea beet (Beta vulgaris ssp. maritima), three sexual types co‐occur: females carrying a cytoplasmic male sterility (CMS) gene, hermaphrodites carrying a non‐CMS cytoplasm and restored hermaphrodites that carry CMS genes and nuclear restorer alleles. This study investigated the effects of fine‐scale genetic structure on male reproductive success of the two hermaphroditic forms. Our study population was strongly structured and characterized by contrasting local sex‐ratios. Pollen flow was constrained over short distances and depended on local plant density. Interestingly, restored hermaphrodites sired significantly more seedlings than non‐CMS hermaphrodites, despite the previous observation that the former produce pollen of lower quality than the latter. This result was explained by the higher frequency of females in the local vicinity of restored (CMS) hermaphrodites as compared to non‐CMS hermaphrodites. Population structure thus strongly influences individual fitness and may locally counteract the expected effects of selection, suggesting that understanding fine scale population processes is central to predicting the evolution of gender polymorphism in angiosperms. 相似文献
125.
Dilara Kaman Necip İlhan Kerem Metin Mehmet Akbulut Bilal Üstündağ 《Cell biochemistry and function》2009,27(2):88-92
Paraoxonase 1 (PON 1) is a high‐density lipoprotein (HDL)‐associated enzyme with antioxidant function protecting low‐density lipoprotein (LDL) from oxidation. PON 1 has two amino acid polymorphisms in coding region; L/M 55 and Q/R 192. These polymorphisms modulate paraoxonase activity of the enzyme. PON 1 activity decreases in coronary artery disease (CAD). In the present study, distribution of PON 1 L/M 55 and Q/R 192 polymorphisms and the effect of these polymorphisms on the activities of PON 1, and on the severity of CAD in 277 CAD (+) patient and 92 CAD (?) subjects were examined. PON 1 L/M 55 and Q/R 192 genotypes were determined by PCR, RFLP and agarose gel electrophoresis techniques. Genotype distributions and allele frequencies for PON 1 Q/R 192 polymorphism were not significantly different between controls and CAD (+) patient group (p > 0.05), but in genotype and allele distribution of PON 1 L/M55 polymorphism, there was significantly difference among groups (p < 0.05). Genotype distributions for both polymorphisms were not significantly different between subgroups of single‐vessel disease (SVD), double‐vessel disease (DVD) and triple‐vessel disease (TVD). Serum PON 1 activity was lower in CAD (+) group than in controls and this was also statistically significant (p < 0.001). In both groups, the highest PON activities were detected in LL and RR genotypes. In summary, our results suggest that there is an association between the PON 1 L/M 55 polymorphism of paraoxonase and CAD in Turkish patients but not with PON 1 Q/R 192 polymorphism. However, it is hard to correlate these polymorphisms and severity of CAD. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
126.
Gülay Bayramoğlu Meral Karakışla Begum Altıntaş Ayşegül U. Metin Mehmet Saçak M. Yakup Arıca 《Process Biochemistry》2009,44(8):880-885
Polyacylonitrile fibers (PAN) surfaces were modified with chemical polymerization of conductive polyaniline (PANI) in the presence of potassium dichromate as an oxidizing agent. The effect of aniline concentration on the grafting efficiency and on the electrical surface resistance of PAN/PANI composite fibers was investigated. The surface resistance of the conductive composite fibers in this work was found to be between 8.0 and 0.5 kΩ/cm. As the amount of grafted PANI increased on the PAN fibers the electrical resistance of composite fibers decreased. The PAN/PANI composite fibers were characterized by SEM and FTIR studies. Composite PAN/PANI fibers were used for reversible immobilization of invertase. The immobilization efficiency and the activity of the immobilized invertase (from 1.0 mg/mL invertase solution at pH 5.5) were increased with increasing PANI contents of the composite fibers. The maximum amount of immobilized enzyme onto composite fibers containing 2.0% PANI was about 76.6 mg/g. The optimum pH for the free enzyme was observed at 5.0. On the other hand, immobilized invertase yielded a broad optimum pH profile between pH 5.0 and 7.0. Immobilized invertase exhibited 83% of its original activity even after two months storage at 4 °C while the free enzyme showed only 7% of its initial activity. 相似文献
127.
Effect of EDTA and Tannic Acid on the Removal of Cd,Ni, Pb and Cu from Artificially Contaminated Soil by Althaea rosea Cavan 总被引:1,自引:0,他引:1
Seydahmet Cay Ahmet Uyanik Mehmet Soner Engin Hamdi Guray Kutbay 《International journal of phytoremediation》2015,17(6):568-574
In this study an ornamental plant of Althaea rosea Cavan was investigated for its potential use in the removal of Cd, Ni, Pb and Cu from an artificially contaminated soil. Effect of two different chelating agents on the removal has also been studied by using EDTA (ethylenediaminetetracetic acid) and TA (tannic acid). Both EDTA and TA have led to higher heavy metal concentration in shoots and leaves compared to control plants. However EDTA is generally known as an effective agent in metal solubilisation of soil, in this study, TA was found more effective to induce metal accumulation in Althaea rosea Cavan under the studied conditions. In addition to this, EDTA is toxic to some species and restraining the growth of the plants. The higher BCF (Bio Concentration Factor) and TF (Translocation Factor) values obtained from stems and leaves by the effects of the chemical enhancers (EDTA and TA) show that Althaea rosea Cavan is a hyper accumulator for the studied metals and may be cultivated to clean the contaminated soils. 相似文献
128.
Samir Khatib Pierre Rochette Mehmet Cihat Alçiçek Anne-Elisabeth Lebatard François Demory Thibaud Saos 《L'Anthropologie》2014
Stratigraphic, sedimentological and paleomagnetic studies were conducted on the travertine from Denizli Basin, near Kocabas village, in the Denizli region in Turkey, following the paleontological discovery in 2002. The stratigraphic and sedimentological studies show at least two main cycles of mass travertine, separated by a fluvial deposit and overlain by a fluvio-lacustrine deposit. These travertines must have formed in environments with strong hydrodynamics (streams or waterfalls) and are preferentially located at breaks of slopes. The paleomagnetic study shows that all the quarry travertine presents reverse magnetic polarity. On the other hand, the detrital fluvio-lacustrine deposit above the travertine presents normal geomagnetic polarity, except at the top, where it is reversed. Given the presence of an archaic Homo erectus skull and Villafranchian paleontological remains in the upper travertine unit, the whole travertine dates from the upper Matuyama, and is more recent than the Olduvai event (1.78 Ma). The normal polarity recorded in the upper fluvio-lacustrine deposit could correspond to the Cobb Mountain excursion, dated to 1.22 Ma. 相似文献
129.
Systemic cladosporiosis is described in 25 merino sheep from a flock consisting 250 animals. The fungal pneumonia appeared
after an intensive antibiotic treatment, because of a respiratory system disorder. The pen of the flock was humid and crowded,
and animals had signs of respiratory distress, coughing, fever and anorexia. All of the ill animals died, and necropsy was
performed on 10 sheep. The lesions were characterized by a multifocal pyogranulomatous pneumonia and an abomasitis. Severe
hemorrhages were observed in the lungs. At the histopathological examination, severe vasculitis with thrombosis was observed
in various organs, especially in the lungs and abomasums, suggestive for a hematogenous dissemination of the infection in
these organs. Numerous PAS-positive fungal elements were seen in the pyogranulomatous foci. Dark green fungal colonies were
seen in the blood agar and Sabouraud dextrose agar that were identified as Cladosporium cladosporioides. This report highlights that phaeohyphomycosis can cause a severe systemic and fatal disease in merino sheep under insufficient
management conditions. 相似文献
130.
Emel Banu Buyukunal Bal Suleyman Bayar Mehmet Ali Bal 《Journal of microbiology (Seoul, Korea)》2010,48(3):267-274
The prevalence and antimicrobial susceptibilities of Staphylococci and Streptococci were assessed from subclinical mastitis
cases. One hundred Coagulase-Negative Staphylococci (CNS) and 34 Streptoccocci were identified. The most frequently isolated
species were Staphylococcus haemolyticus (27%) and Staphylococcus simulans (24%). Susceptible CNS species revealed the highest resistance to penicillin G (58%), ampicillin (48%), neomycin (20%), and
oleandomycin (14%). CNS methicillin resistance rates within 82 isolates were 21.95% and 1.22% by disk diffusion and PCR methods,
respectively. These results suggested the disk diffusion method was more prone to yield false positives. Partial sequencing
of the 16S rRNA region from the mecA carrying isolate (S. haemolyticus) was homologous with S. haemolyticus sequences/accessions obtained from GenBank. However, the mecA gene sequence from this isolate was more closely allied with the S. aureus mecA gene of human origins. Identical sequence data was acquired from the National Center for Biotechnology Information (NCBI)
database, suggesting horizontal gene transfer between the two species. CNS β-lactamase activity within 81 isolates was 29.63%.
The most frequently isolated Streptococcus species were S. uberis (52%) and S. agalactiae (15%). Oleandomycin was the least effective antimicrobial agent on these isolates with 59% susceptibility. Results indicated
that CNS and Streptococci exhibited various antimicrobial resistance responses. Consequently, isolation and identification
of udder pathogens in herds suffering from subclinical agents is essential to select the most effective antimicrobial agent.
Moreover, multiple resistance features of methicillin resistant (MR) isolates should be considered during antimicrobial susceptibility
tests. 相似文献