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81.
Deletion/insertion mutation that causes biotinidase deficiency may result from the formation of a quasipalindromic structure 总被引:2,自引:0,他引:2
Pomponio RJ; Narasimhan V; Reynolds TR; Buck GA; Povirk LF; Wolf B 《Human molecular genetics》1996,5(10):1657-1661
Biotinidase is responsible for recycling the vitamin biotin from biocytin
that is formed after the proteolytic degradation of the biotin- dependent
carboxylases. We have identified a deletion/insertion mutation within exon
D of the human biotinidase gene in a child with biotinidase deficiency. The
mutation causes a frame shift and premature termination which are predicted
to result in a truncated protein. We propose that the mutation occurred
during DNA replication by either of two mechanisms. Both mechanisms involve
formation of a quasipalindromic hairpin loop in the template and
dissociation of DNA polymerase alpha. This mutation supports the formation
of palindromic structures as a possible cause of deletions in eukaryotes,
and supports the proposal, derived from in vitro studies, that polymerase
alpha may preferentially arrest or dissociate at specific template
sequences.
相似文献
82.
Small lesions in the heart identified at electron beam CT: calcification or noise? 总被引:11,自引:0,他引:11
Bielak LF; Kaufmann RB; Moll PP; McCollough CH; Schwartz RS; Sheedy PF nd 《Radiology》1994,192(3):631
83.
84.
二苯乙烯类化合物对蛋白激酶C的抑制作用 总被引:14,自引:0,他引:14
报道15种二苯乙烯类化合物对蛋白激酶C(PKC)活性的影响。其中从中药金雀根中分得的3种二苯乙烯类低聚体α-viniferin,kobophenol A 和 miyabenolC,它们抑制PKC的IC50分别为62.5,52.0和27.5μmol·L-1。另外6种含酚羟基的二苯乙烯化合物对PKC也显示不同程度的抑制作用,但当酚羟基全甲基化或全乙酰化后其抑制作用大大降低甚至消失。酶动力学研究证明miyabenolC对PKC的抑制作用属于非竞争性抑制。 相似文献
85.
Tirapelli CR Ambrosio SR Coutinho ST de Oliveira DC da Costa FB de Oliveira AM 《The Journal of pharmacy and pharmacology》2005,57(8):997-1004
The vascular effects of two natural occurring diterpenes from the kaurane and pimarane classes were compared. The diterpenes ent-kaur-16-en-19-oic acid (kaurenoic acid; KA) and ent-pimara-8(14), 15-dien-19-oic acid (pimaradienoic acid; PA) were tested for their antispasmodic activity on isolated rat aorta. Vascular reactivity experiments, using standard muscle bath procedures, showed that KA and PA (both at 50 and 100 microM) inhibited phenylephrine and KCl-induced contraction in both endothelium-intact and endothelium-denuded rat aortic rings, with PA being more effective than KA. These compounds also reduced CaCl(2)-induced contraction in Ca(2+)-free solution containing KCl (30 mm). Again, PA produced a greater reduction in CaCl(2)-induced contraction than KA. PA (1-300 microM) and KA (1-450 microM) concentration dependently relaxed endothelium-denuded aortic rings pre-contracted with KCl (maximum relaxation 102.31+/-6.94% and 82.71+/-1.40%, respectively). Similarly, the relaxation induced by KA on aortic rings pre-contracted with phenylephrine (73.06+/-3.68%) was less pronounced than that found for PA (102.21+/-3.64%). Incubation of endothelium-denuded rings for different periods showed that at 50 microM, KA and PA achieved maximum inhibitory activity on KCl-induced contraction after incubation for 60 (53.48+/-5.83%) and 30 min (83.89+/-2.12%), respectively. At 100 microM, KA and PA inhibited KCl-induced contraction, with a maximum after incubation for 30 min (73.58+/-5.30% and 92.07+/-1.20%, respectively). The maximum inhibition induced by PA at both concentrations tested was greater than that induced by KA. The results provide evidence that structural differences between diterpenes, independent of the C-19 carboxylic acid site, influence selectivity for voltage-operated Ca2+ channels and rate of equilibrium with the target site for their vasorelaxant action in rat aortic rings. 相似文献
86.
87.
Analysis with antiidiotype antibody of a patient with chronic lymphocytic leukemia and a large cell lymphoma (Richter's syndrome) 总被引:1,自引:0,他引:1
Bertoli LF; Kubagawa H; Borzillo GV; Mayumi M; Prchal JT; Kearney JF; Durant JR; Cooper MD 《Blood》1987,70(1):45-50
A murine monoclonal antibody made against an idiotypic determinant (Id) of surface IgM/IgD lambda molecules on chronic lymphocytic leukemia (CLL) cells of a 71-year-old woman was used for clonal analysis by two- color immunofluorescence. The anti-Id antibody identified IgM+/IgD+/lambda+ B cells as the predominant cell type of her CLL clone. In addition, substantial proportions of the IgG and IgA B cells and most of the IgM plasma cells in her bone marrow and blood were Id+. Six years after diagnosis, the patient died of respiratory failure due to infiltration of lungs by malignant cells. Autopsy revealed a dramatic change in the tumor cell morphology. The lungs, hilar nodes, and liver were infiltrated by a diffuse large cell lymphoma admixed with the leukemic cells. By immunohistologic staining these anaplastic lymphoma cells were IgM+/IgD-/lambda+ B cells expressing the same Id noted earlier on the CLL cells. The immunoglobulin gene rearrangement pattern on Southern blot analysis was also the same in leukemic blood cells and in the tissues involved by the lymphoma. Thus, the combination of antiidiotype and immunoglobulin gene analyses in this patient with Richter's syndrome revealed that a CLL clone, seemingly "frozen" in differentiation, was actually undergoing isotype switching, differentiation into plasma cells, and evolution into a rapidly growing and fetal lymphoma. 相似文献
88.
89.
FTC Matos VHT Rizo LY Almeida C Tirapelli YTC Silva‐Sousa OP Almeida JE León 《Oral diseases》2013,19(1):85-91
Oral Diseases (2012) 19 , 85–91 Objective: To analyze the expression and distribution patterns of mature dendritic cells (mDCs) and immature DCs (imDCs) in radicular cysts (RCs), dentigerous cysts (DtCs), and keratocystic odontogenic tumors (KCOTs). Materials and methods: Forty‐nine odontogenic cystic lesions (OCLs) (RCs, n = 20; DtCs, n = 15; KCOTs, n = 14) were assessed using the following markers: S100, CD1a and CD207 for imDCs; and CD83 for mDCs. Results: Almost all cases were S100, CD1a, and CD207 positive, whereas 63% were CD83 positive. RCs presented greater number of immunostained cells, followed by DtCs, and KCOTs. The number of S100+ cells was greater than both CD1a+ and CD207+ cells (P < 0.001), which showed approximately similar amounts, followed by lower number of CD83+ cells (P < 0.001) in each OCL type. Different from S100+ cells, both CD1a+ and CD207+ cells on the epithelium (P < 0.05) and CD83+ cells on the capsule (P < 0.05) were preferentially observed. In RCs, significant correlation was found between the thickness epithelium with S100+ and CD1a+ cells, and between the degree of inflammation with CD83+ cells. Conclusions: Dendritic cell populations in OCLs can be phenotypically heterogeneous, and it could represent distinct lineages and/or functional stages. It is suggested that besides DC‐mediated immune cell interactions, DC‐mediated tissue differentiation and maintenance in OCLs should also be considered. 相似文献
90.
Pintado-Palomino Karen de Almeida Cecilia Vilela Vasconcelos Barros da Motta Raphael Jurca Gonçalves Fortes João Henrique Parise Tirapelli Camila 《Clinical oral investigations》2019,23(4):1855-1864
Clinical Oral Investigations - To evaluate the clinical performance of posterior resin composite restorations regarding experimental and regular adhesive protocols in caries affected-dentin (CAD).... 相似文献