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71.
72.
József Lanszki Giorgos Giannatos Amit Dolev Gilad Bino Miklós Heltai 《Acta theriologica》2010,55(4):361-370
The feeding habits of the golden jackal Canis aureus (Linnaeus, 1758) were compared using scat analysis in Hungary (temperate
climate agricultural area), Greece (Mediterranean marshland), and Israel (Mediterranean agricultural area). Samples (84, 70
and 64 scats, respectively) were collected during late autumn, a period with capital importance to the long term survival
of young jackals, during which they become independent. Predation of wild-living prey species was highest in Hungary, consisting
primarily of small mammals (biomass estimation: 51.5%, mainly rodents), contrary to Israel and Greece, where scavenging on
domestic animals dominated the diet of jackals (74%, mainly poultry and 62.6%, mainly goats, respectively). The highest consumption
of wild ungulates (mainly wild boar) was found in Greece (15.7%), and plants in Hungary (39%). Bird consumption was low in
all three areas. Reptiles, amphibians and fish occurred only in the diet of jackals in Greece and Israel, whereas invertebrates
were eaten more frequently in Hungary. Jackal dietary composition was extremely variable between regions, strongly associated
with human presence. These results illustrate the golden jackal as having a very variable diet, resulting from opportunistic
feeding habits. 相似文献
73.
Norberg E Karlsson M Korenovska O Szydlowski S Silberberg G Uhlén P Orrenius S Zhivotovsky B 《The EMBO journal》2010,29(22):3869-3878
Cellular calcium uptake is a controlled physiological process mediated by multiple ion channels. The exposure of cells to either one of the protein kinase C (PKC) inhibitors, staurosporine (STS) or PKC412, can trigger Ca2+ influx leading to cell death. The precise molecular mechanisms regulating these events remain elusive. In this study, we report that the PKC inhibitors induce a prolonged Ca2+ import through hyperpolarization‐activated cyclic nucleotide‐gated channel 2 (HCN2) in lung carcinoma cells and in primary culture of cortical neurons, sufficient to trigger apoptosis‐inducing factor (AIF)‐mediated apoptosis. Downregulation of HCN2 prevented the drug‐induced Ca2+ increase and subsequent apoptosis. Importantly, the PKC inhibitors did not cause Ca2+ entry into HEK293 cells, which do not express the HCN channels. However, introduction of HCN2 sensitized them to STS/PKC412‐induced apoptosis. Mutagenesis of putative PKC phosphorylation sites within the C‐terminal domain of HCN2 revealed that dephosphorylation of Thr549 was critical for the prolonged Ca2+ entry required for AIF‐mediated apoptosis. Our findings demonstrate a novel role for the HCN2 channel by providing evidence that it can act as an upstream regulator of cell death triggered by PKC inhibitors. 相似文献
74.
Brigham B. Hyde Gilad Twig Orian S. Shirihai 《Seminars in cell & developmental biology》2010,21(6):575-581
Mitochondrial dynamics, the fusion and fission of individual mitochondrial units, is critical to the exchange of the metabolic, genetic and proteomic contents of individual mitochondria. In this regard, fusion and fission events have been shown to modulate mitochondrial bioenergetics, as well as several cellular processes including fuel sensing, ATP production, autophagy, apoptosis, and the cell cycle. Regulation of the dynamic events of fusion and fission occur at two redundant and interactive levels. Locally, the microenvironment of the individual mitochondrion can alter its ability to fuse, divide or move through the cell. Globally, nuclear-encoded processes and cellular ionic and second messenger systems can alter or activate mitochondrial proteins, regulate mitochondrial dynamics and concomitantly change the condition of the mitochondrial population. In this review we investigate the different global and local signals that control mitochondrial biology. This discussion is carried out to clarify the different signals that impact the status of the mitochondrial population. 相似文献
75.
Gilad J Borer A Smolyakov R Riesenberg K Schlaeffer F Levy R 《Microbes and infection / Institut Pasteur》2006,8(7):1801-1805
Staphylococcus aureus is an important cause of skin infections. We recently described an outbreak of recurrent furunculosis involving methicillin-resistant S. aureus among mentally retarded adults. We sought to determine the role of impaired neutrophil functions in its pathogenesis. Blood neutrophil functions were determined during both the outbreak (1997) and a disease-free period (2000). Chemotaxis was measured by migration toward formyl-methionyl-leucyl-phenylalanine (FMLP), specifically and randomly; phagocytosis of opsonized zymosan (OZ) was assessed by microscopy; superoxide production was determined by cytochrome c reduction in unstimulated neutrophils and after stimulation with 50 ng/ml phorbol myristate acetate, 1 mg/ml OZ or 5 x 10(-7)M FMLP. Functions were compared between recurrent furunculosis (n=10) and non-recurrent furunculosis patients (n=13). During 2000, functions were normal among the 23 subjects, except for specific/nonspecific chemotaxis (mean 68%+/-26 and 69%+/-28). During infection, recurrent furunculosis patients had a significantly increased basal superoxide production as compared to disease-free period (10.5+/-4.7 vs. 4.9+/-1.9 nmol O(-)(2)/10(6) cells/min, p=0.003). During the disease-free period, recurrent furunculosis patients had lower basal superoxide production (4.9+/-1.9 vs. 7.7+/-3.5, p=0.067) and impaired specific chemotaxis (57%+/-28 vs. 76%+/-21, p<0.05) as compared to non-recurrent furunculosis patients. Only specific chemotaxis was an independent risk factor for recurrent furunculosis. Mentally retarded adults have impaired chemotaxis, with recurrent furunculosis cases having an even greater impairment. Abnormal specific chemotaxis is an independent risk factor for recurrent furunculosis. Impaired neutrophil functions thus have a role in the pathogenesis of outbreaks of recurrent furunculosis. 相似文献
76.
Bourguignon LY Singleton PA Diedrich F Stern R Gilad E 《The Journal of biological chemistry》2004,279(26):26991-27007
We have explored CD44 (a hyaluronan (HA) receptor) interaction with a Na(+)-H(+) exchanger (NHE1) and hyaluronidase-2 (Hyal-2) during HA-induced cellular signaling in human breast tumor cells (MDA-MB-231 cell line). Immunological analyses demonstrate that CD44s (standard form) and two signaling molecules (NHE1 and Hyal-2) are closely associated in a complex in MDA-MB-231 cells. These three proteins are also significantly enriched in cholesterol and ganglioside-containing lipid rafts, characterized as caveolin and flotillin-rich plasma membrane microdomains. The binding of HA to CD44 activates Na(+)-H(+) exchange activity which, in turn, promotes intracellular acidification and creates an acidic extracellular matrix environment. This leads to Hyal-2-mediated HA catabolism, HA modification, and cysteine proteinase (cathepsin B) activation resulting in breast tumor cell invasion. In addition, we have observed the following: (i) HA/CD44-activated Rho kinase (ROK) mediates NHE1 phosphorylation and activity, and (ii) inhibition of ROK or NHE1 activity (by treating cells with a ROK inhibitor, Y27632, or NHE1 blocker, S-(N-ethyl-N-isopropyl) amiloride, respectively) blocks NHE1 phosphorylation/Na(+)-H(+) exchange activity, reduces intracellular acidification, eliminates the acidic environment in the extracellular matrix, and suppresses breast tumor-specific behaviors (e.g. Hyal-2-mediated HA modification, cathepsin B activation, and tumor cell invasion). Finally, down-regulation of CD44 or Hyal-2 expression (by treating cells with CD44 or Hyal-2-specific small interfering RNAs) not only inhibits HA-mediated CD44 signaling (e.g. ROK-mediated Na(+)-H(+) exchanger reaction and cellular pH changes) but also impairs oncogenic events (e.g. Hyal-2 activity, hyaluronan modification, cathepsin B activation, and tumor cell invasion). Taken together, our results suggest that CD44 interaction with a ROK-activated NHE1 (a Na(+)-H(+) exchanger) in cholesterol/ganglioside-containing lipid rafts plays a pivotal role in promoting intracellular/extracellular acidification required for Hyal-2 and cysteine proteinase-mediated matrix degradation and breast cancer progression. 相似文献
77.
A model is presented that allows prediction of the probability for the formation of appositions between the axons and dendrites
of any two neurons based only on their morphological statistics and relative separation. Statistics of axonal and dendritic
morphologies of single neurons are obtained from 3D reconstructions of biocytin-filled cells, and a statistical representation
of the same cell type is obtained by averaging across neurons according to the model. A simple mathematical formulation is
applied to the axonal and dendritic statistical representations to yield the probability for close appositions. The model
is validated by a mathematical proof and by comparison of predicted appositions made by layer 5 pyramidal neurons in the rat
somatosensory cortex with real anatomical data. The model could be useful for studying microcircuit connectivity and for designing
artificial neural networks.
Received: 11 February 2002 / Accepted: 5 November 2002 / Published online: 20 February 2003
Correspondence to: H. Markram (e-mail: Henry.Markram@epfl.ch Tel.: +41-21-6939537, Fax: +41-21-6935350)
Acknowledgements. This study was supported by the National Alliance for Autism Research, the Minerva Foundation, the US Navy, the Ebner Center
for Biomedical Research, and the Edith Blum Foundation. 相似文献
78.
Bachrach G Haake SK Glick A Hazan R Naor R Andersen RN Kolenbrander PE 《Applied and environmental microbiology》2004,70(12):6957-6962
Fusobacterium nucleatum is an important oral anaerobic pathogen involved in periodontal and systemic infections. Studies of the molecular mechanisms involved in fusobacterial virulence and adhesion have been limited by lack of systems for efficient genetic manipulation. Plasmids were isolated from eight strains of F. nucleatum. The smallest plasmid, pKH9 (4,975 bp), was characterized and used to create new vectors for fusobacterial genetic manipulation. DNA sequence analysis of pKH9 revealed an open reading frame (ORF) encoding a putative autonomous rolling circle replication protein (Rep), an ORF predicted to encode a protein homologous to members of the FtsK/SpoIIIE cell division-DNA segregation protein family, and an operon encoding a putative toxin-antitoxin plasmid addiction system (txf-axf). Deletion analysis localized the pKH9 replication region in a 0.96-kbp fragment. The pKH9 rep gene is not present in this fragment, suggesting that pKH9 can replicate in fusobacteria independently of the Rep protein. A pKH9-based, compact Escherichia coli-F. nucleatum shuttle plasmid was constructed and found to be compatible with a previously described pFN1-based fusobacterial shuttle plasmid. Deletion of the pKH9 putative addiction system (txf-axf) reduced plasmid stability in fusobacteria, indicating its addiction properties and suggesting it to be the first plasmid addiction system described for fusobacteria. pKH9, its genetic elements, and its shuttle plasmid derivatives can serve as useful tools for investigating fusobacterial properties important in biofilm ecology and pathogenesis. 相似文献
79.
S Gilad L Chessa R Khosravi P Russell Y Galanty M Piane R A Gatti T J Jorgensen Y Shiloh A Bar-Shira 《American journal of human genetics》1998,62(3):551-561
Ataxia-telangiectasia (A-T) is an autosomal recessive disorder characterized by cerebellar degeneration, immunodeficiency, chromosomal instability, radiosensitivity, and cancer predisposition. A-T cells are sensitive to ionizing radiation and radiomimetic chemicals and fail to activate cell-cycle checkpoints after treatment with these agents. The responsible gene, ATM, encodes a large protein kinase with a phosphatidylinositol 3-kinase-like domain. The typical A-T phenotype is caused, in most cases, by null ATM alleles that truncate or severely destabilize the ATM protein. Rare patients with milder manifestations of the clinical or cellular characteristics of the disease have been reported and have been designated "A-T variants." A special variant form of A-T is A-TFresno, which combines a typical A-T phenotype with microcephaly and mental retardation. The possible association of these syndromes with ATM is both important for understanding their molecular basis and essential for counseling and diagnostic purposes. We quantified ATM-protein levels in six A-T variants, and we searched their ATM genes for mutations. Cell lines from these patients exhibited considerable variability in radiosensitivity while showing the typical radioresistant DNA synthesis of A-T cells. Unlike classical A-T patients, these patients exhibited 1%-17% of the normal level of ATM. The underlying ATM genotypes were either homozygous for mutations expected to produce mild phenotypes or compound heterozygotes for a mild and a severe mutation. An A-TFresno cell line was found devoid of the ATM protein and homozygous for a severe ATM mutation. We conclude that certain "A-T variant" phenotypes represent ATM mutations, including some of those without telangiectasia. Our findings extend the range of phenotypes associated with ATM mutations. 相似文献
80.
Identification and nucleotide sequence of Brucella melitensis L7/L12 ribosomal protein 总被引:4,自引:0,他引:4
Gilad Bachrach Dror Bar-Nir Menachem Banai Herve Bercovier 《FEMS microbiology letters》1994,120(3):237-240
Abstract DNA sequencing of the gene encoding a Brucella melitensis 12-kDa protein revealed that this protein was the ribosomal protein L7/L12. The B. melitensis L7/L12 DNA sequence was identical to that of the corresponding B. abortus gene, showing the near identity of these two organisms. When comparing the sequence of this protein to that of other organisms some domains were highly conserved, especially the C-terminus, which contrasted with the lack of conservation of the sequences at the N-terminus. The finding that the ribosomal protein L7/L12 of Brucella is an immunodominant antigen provides a new rationale to explain the activity of ribosomal vaccines. 相似文献