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941.
Lactate dehydrogenase (LDH), marker of anaerobic metabolism, is associated with highly invasive and metastatic breast cancer. Novel studies show that increased anaerobic metabolism (LDH), as well as activity of antioxidative enzymes (superoxide dismutase (SOD) and catalase (CAT)), is correlated with higher mammographic density, as known predictor of breast cancer risk. In this study, we measured LDH, MDH, and SOD activity in tumor and adjacent tissues of breast cancer patients by spectrophotometric assay. Mammograms were evaluated according to the American College of Radiology Breast Imaging Reporting and Data system. Mammographically dense breast tissue is associated with higher activity of LDH in tumor tissue of breast cancer patients. Moreover, patients with masses have significantly higher activity of LDH compared to patients with focal asymmetries or architectural distortion. Patients with spiculated mass margin had higher activity of LDH compared to patients with focal asymmetries or architectural distortion. Activity of LDH in patients significantly increases, while activity of CAT significantly decreases with the increase of BIRADS category. These results suggest that the association of activity of LDH and CAT in tumor tissue with mammographic characteristics could help in defining aggressive breast cancers.  相似文献   
942.
ObjectiveTo investigate whether size at birth and rate of fetal growth influence the risk of breast cancer in adulthood.DesignCohort identified from detailed birth records, with 97% follow up.SettingUppsala Academic Hospital, Sweden.Participants5358 singleton females born during 1915-29, alive and traced to the 1960 census.ResultsSize at birth was positively associated with rates of breast cancer in premenopausal women. In women who weighed ⩾4000 g at birth rates of breast cancer were 3.5 times (95% confidence interval 1.3 to 9.3) those in women of similar gestational age who weighed <3000 g at birth. Rates in women in the top fifths of the distributions of birth length and head circumference were 3.4 (1.5 to 7.9) and 4.0 (1.6 to 10.0) times those in the lowest fifths (adjusted for gestational age). The effect of birth weight disappeared after adjustment for birth length or head circumference, whereas the effects of birth length and head circumference remained significant after adjustment for birth weight. For a given size at birth, gestational age was inversely associated with risk (P=0.03 for linear trend). Adjustment for markers of adult risk factors did not affect these findings. Birth size was not associated with rates of breast cancer in postmenopausal women.ConclusionsSize at birth, particularly length and head circumference, is associated with risk of breast cancer in women aged <50 years. Fetal growth rate, as measured by birth size adjusted for gestational age, rather than size at birth may be the aetiologically relevant factor in premenopausal breast cancer.

What is already known on this topic

There is some evidence that birth weight is related to risk of breast cancerThe exact nature of any association and whether it differs at premenopausal and postmenopausal ages is unclearFew studies have examined the effect of other measures of birth size and of gestational age

What this study adds

There are strong positive associations between measures of birth size and rates of breast cancer at premenopausal ages that persisted after adjustment for adult risk factorsFor a given birth size, gestational age was inversely associated with risk, suggesting that the rate of fetal growth may be aetiologically relevant to premenopausal breast cancerThere was no association between birth characteristics and rates of breast cancer at postmenopausal ages  相似文献   
943.
This work presents an improved stopped-flow protocol for the simultaneous measurement of thermodynamic and kinetic protein stability data from a single experiment, along with a formalism for the global analysis of the data. The method was applied to the comparison of the stabilities of cytochrome c(6) from Anabaena sp. PCC 7119 and one of its mutants (D72K). Compared to the wild type the mutant was found to have a significantly reduced thermodynamic (deltadeltaG(U0)=2.7 kJ mol(-1)) and kinetic stability, as well as a more pronounced shift in transition state structure upon destabilization.  相似文献   
944.
945.
紫斑牡丹及其一新亚种   总被引:7,自引:4,他引:7  
本文回顾了有关紫斑牡丹的调查和分类历史。它曾被混同于 P.suffruticosa,P.papaveracea 及P.suffruticosa var.papaveracea。它以叶2至3回羽状复叶,小叶17~33,花瓣白色,基部有大紫斑, 花丝黄色,花盘和柱头淡黄色区别于近缘种。种下分化为两个异域的亚种;秦岭北坡的紫斑牡丹小叶全 部或大部分分裂,是一个新亚种,P.rockii subsp.taibaishanica,而P.rockii subsp.linyanshanii T.Hong et G.L.ostii则是P.rockii subsp.rockii的多余名。  相似文献   
946.
Summary Freshwater eel gills are notorious for their limited ability to pump chloride. As a result there is a considerable discrepancy between the Na+ and Cl plasma levels, and plasma HCO3 and blood pH are relatively high in this species.When eels are kept in tanks aerated with pure oxygen, significant alterations in blood acid-base balance, an increase in plasma pCO2 and a decrease in blood pH, are observed. In fish studied after 3 weeks hyperoxia, the decrease in blood pH is compensated by an increase in plasma HCO3 . Such fish exhibit a Cl influx 5 times higher than that observed in normoxic fish. This Cl influx is readily inhibited by addition of SCN to the external medium.An anion-stimulated ATPase activated by HCO3 and by Cl and inhibited by SCN was recently described in membrane fractions of the gills ofCarassius auratus, a fish noted for its high Cl pumping rate. This enzyme is also found in the gills of the eel. While the maximal rates of enzyme activation by HCO3 and by Cl are similar inCarassius andAnguilla, the affinity of the enzyme for Cl is 25 times higher inCarassius. In the microsomal fraction of the hyperoxic eel gills, the maximal anionstimulated ATPase activity remains unchanged but HCO3 affinity decreases by 50%, while Cl affinity increases 5 times. Thus some characteristics of this ATPase seem to be closely related to the Cl pump activity exhibited by the gill in fresh water.  相似文献   
947.
948.

Background

We have previously reported a novel fungal galectin Agrocybe aegerita lectin (AAL) with apoptosis-induced activity and nuclear migration activity. The importance of nuclear localization for AAL's apoptosis-induced activity has been established by mutant study. However, the mechanism remains unclear.

Methods

We further investigated the mechanism using a previously reported carbohydrate recognition domain (CRD) mutant protein H59Q, which retained its nuclear localization activity but lost most of its apoptotic activity. The cell membrane-binding ability of recombinant AAL (rAAL) and H59Q was analyzed by FACS, and their cellular partners were identified by affinity chromatography and mass spectroscopy. Furthermore, the interaction of AAL and ligand was proved by mammalian two-hybrid and pull down assays. A knockdown assay was used to confirm the role of the ligand.

Results

The apoptotic activity of AAL could be blocked by lactose. Mutant H59Q retained comparable cell membrane-binding ability to rAAL. Four cellular binding partners of AAL in HeLa cells were identified: glucose-regulated protein 78 (GRP78); mortality factor 4-like protein 1 (MRG15); elongation factor 2 (EEF2); and heat shock protein 70 (Hsp70). CRD region of AAL was required for the interaction between AAL/mutant AAL and MRG15. MRG15 knockdown increased the cells' resistance to AAL treatment.

Conclusion

MRG15 was a nuclear ligand for AAL in HeLa cells. These data implied the existence of a novel nuclear pathway for the antitumor activity of fungal galectin AAL.

General significance

These findings provide a novel explanation of AAL bioactivity and contribute to the understanding of mushroom lectins' antitumor activity.  相似文献   
949.
Ischemic heart disease is the leading cause of serious morbidity and mortality in Western society. One of the therapeutic approaches is based on the use of thrombolitic drugs that promote clot lysis. Even if the mechanisms leading to clot lysis are not completely understood, it is widely accepted that they depend on the complex biochemical reactions that occur among fibrin fibers and fibrinolitic agents, and by their ready diffusion into the fibers. Here we investigate the effects of specific anions on the architecture of protofibrils within fibrin fibers in fibrin gels prepared in a para-physiological solution. The results obtained through small-angle X-ray scattering (SAXS) demonstrate that the characteristic axial and longitudinal repeat distances among protofibrils are strongly affected by the action of Cl and F anions.  相似文献   
950.
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