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1.
Ziv Radisavljevic 《Journal of cellular physiology》2013,228(1):21-24
Angiogenesis get full robustness in metastatic cancer, relapsed leukemia or lymphoma when complex positive feedback loop signaling systems become integrative. A cancer hypoxic microenvironment generates positive loops inducing formation of the vascular functional shunts. AKT is an upstream angiogenic locus of integrative robustness and fragility activated by the positive loops. AKT controls two downstream nodes the mTOR and NOS in nodal organization of the signaling genes. AKT phosphorylation is regulated by a balance of an oxidant/antioxidant. Targeting AKT locus represents new principle to control integrative angiogenic robustness by the locus chemotherapy. J. Cell. Physiol. 228: 21–24, 2013. © 2012 Wiley Periodicals, Inc. 相似文献
2.
Y. Ziv M. Frydman E. Lange N. Zelnik G. Rotman C. Julier N. G. J. Jaspers Y. Dagan D. Abeliovicz H. Dar Z. Borochowitz M. Lathrop R. A. Gatti Y. Shiloh 《Human genetics》1992,88(6):619-626
Summary Ataxia-telangiectasia (A-T) is a progressive autosomal recessive disease featuring neurodegeneration, immunodeficiency, chromosomal instability, radiation sensitivity and a highly increased proneness to cancer. A-T is ethnically widespread and genetically heterogeneous, as indicated by the existence of four complementation groups in this disease. Several A-T-like genetic diseases share various clinical and cellular characteristics with A-T. By using linkage analysis to study North American and Turkish A-O families, the ATA (A-T, complementation group A) gene has been mapped to chromosome 11q23. A number of Israeli Arab A-T patients coming from large, highly inbred families were assigned to group A In one of these families, an additional autosomal recessive disease was identified, characterized by ataxia, hypotonia, microcephaly and bilateral congenital cataracts. In two patients with this syndrome, normal levels of serum immunoglobulins and alpha-fetoprotein, chromosomal stability in peripheral blood lymphocytes and skin fibroblasts, and normal cellular response to treatments with X-rays and the radiomimetic drug neocarzinostatin indicated that this disease does not share, with A-T, any additional features other than ataxia. These tests also showed that another patient in this family, who is also mentally retarded, is affected with both disorders. This conclusion was further supported by linkage analysis with 11q23 markers. Lod scores between A-O and these markers, cumulated over three large Arab families, were significant and confirmed the localization of the ATA gene to aq23. However, another Druze family unassigned to a specific complementation group, showed several recombinants between A-T and the same markers, leaving the localization of the A-T gene in this family open. 相似文献
3.
4.
Ziv Bar-Joseph Georg K Gerber David K Gifford Tommi S Jaakkola Itamar Simon 《Journal of computational biology》2003,10(3-4):341-356
We present algorithms for time-series gene expression analysis that permit the principled estimation of unobserved time points, clustering, and dataset alignment. Each expression profile is modeled as a cubic spline (piecewise polynomial) that is estimated from the observed data and every time point influences the overall smooth expression curve. We constrain the spline coefficients of genes in the same class to have similar expression patterns, while also allowing for gene specific parameters. We show that unobserved time points can be reconstructed using our method with 10-15% less error when compared to previous best methods. Our clustering algorithm operates directly on the continuous representations of gene expression profiles, and we demonstrate that this is particularly effective when applied to nonuniformly sampled data. Our continuous alignment algorithm also avoids difficulties encountered by discrete approaches. In particular, our method allows for control of the number of degrees of freedom of the warp through the specification of parameterized functions, which helps to avoid overfitting. We demonstrate that our algorithm produces stable low-error alignments on real expression data and further show a specific application to yeast knock-out data that produces biologically meaningful results. 相似文献
5.
David L. Cheo Lisiane B. Meira Robert E. Hammer Dennis K. Burns Ana T.B. Doughty Errol C. Friedberg 《Current biology : CB》1996,6(12)
The significance of DNA repair to human health has been well documented by studies on xeroderma pigmentosum (XP) patients, who suffer a dramatically increased risk of cancer in sun-exposed areas of their skin [1] and [2]. This autosomal recessive disorder has been directly associated with a defect in nucleotide excision–repair (NER) [1] and [2]. Like human XP individuals, mice carrying homozygous mutations in XP genes manifest a predisposition to skin carcinogenesis following exposure to ultraviolet (UV) radiation [3], [4] and [5]. Recent studies have suggested that, in addition to roles in apoptosis [6] and cell-cycle checkpoint control [7] in response to DNA damage, p53 protein may modulate NER [8]. Mutations in the p53 gene have been observed in 50% of all human tumors [9] and have been implicated in both the early [10] and late [11] stages of skin cancer. To examine the consequences of a combined deficiency of the XPC and the p53 proteins in mice, we generated double-mutant animals. We document a spectrum of neural tube defects in XPC p53 mutant embryos. Additionally, we show that, following exposure to UV-B radiation, XPC p53 mutant mice have more severe solar keratosis and suffer accelerated skin cancer compared with XPC mutant mice that are wild-type with respect to p53. 相似文献
6.
The effects of the genotype and growth medium composition on callus induction and shoot regeneration from tomato (Lycopersicon esculentum Mill) anthers were studied. Five male sterile varieties, homozygous for the recessive gene ms 1035, their isogenic fertile counterparts, and nineteen sterile mutants from an F2 population segregating for ms 1035, were tested. Callus induction and shoot formation were found to be affected by the genotype. The presence of the mutant gene ms 1035 greatly increased callus induction. A significant interaction concerning callus induction was found between the ms 1035 gene and the general genetic background. In most of the plants shoot regeneration from the anthers was associated with various degrees of callus production. However, there was no correlation between callus production and the ability to regenerate plants from that callus. Anthers isolated from plants which were heterozygous for the recessive leaf marker trifoliate, regenerated diploid plants with trifoliate leaves. The plants retained the trifoliate phenotype for over six months in culture under non-aseptic condition. Since the trifoliate phenotype appears only in the homozygous recessive state, the evidence that these trifoliate plants are doubled haploids of sporogenic origin is discussed. 相似文献
7.
Philodendron plants propagated in liquid shake or bioreactor cultures proliferated profusely in the presence of paclobutrazol (PAC) and to a lesser extent in the presence of ancymidol (ANC). The growth retardants inhibited leaf development and induced the formation of bud clusters. Short transient treatments with low concentrations (1.7–3.4 M) of the growth retardants limited leaf growth and proliferation to a lesser extent than higher concentrations (6.8–17 M). The growth retardants had a carryover dwarfing effect in the semi-solid hardening medium, which was more pronounced at the higher concentrations or prolonged exposure periods. Regenerated plants resumed normal growth 3–6 weeks after transplanting. Treatment with growth retardants may become a useful method in the prevention of abnormal leaf growth in large-scale liquid cultures, as well as in enhancing bud proliferation. 相似文献
8.
The influence of various c oncentrations of K⁺, nitrogen sources, and inoculation with root-knot nematode Meloidogyne javanica were evaluated in tomato plants. Increased potassium concentration increased top and root fresh weights of intact plants and fresh weights of excised roots. Nitrate-fertilized plants weighed more than plants receiving ammonium independent of the K level in the medium. Nematode counts on roots were not affected by nutritional differences in intact or excised roots. In intact roots a high percentage of males was recorded at low K⁺ levels, whereas in excised roots the proportion of males in the population rose as the K⁺ levels increased. Inoculated intact roots accumulated K⁺ when the level of potassium supply was low; infected excised roots contained less K⁺ than did nematode-free roots. 相似文献
9.
The o-nitrophenylsulfenyl group, and amino protecting group in the chemical synthesis of peptidyl-tRNA was used to attach newly synthesized peptidyl-tRNA to a benzoylated DEAE-cellulose column. This facilitated the isolation of a highly purified specific tRNA with a well defined peptide chain. 相似文献
10.