scholarly journals Lipid fluidity of triacylglycerol-rich lipoproteins isolated from copper-deficient rats

1996 ◽  
Vol 75 (5) ◽  
pp. 767-773 ◽  
Author(s):  
Claude Motta ◽  
Elyett Gueux ◽  
Andrzej Mazur ◽  
Yves Rayssiguier

Triacylglycerol-rich lipoproteins (TGRLP) were isolated from Cu-deficient and control rats. TGRLP from Cu-deficient rats appeared more fluid than those from controls as sensed by the fluorescence anisotropy of 1,6-diphenyl-l-3,5-hexatriene (DPH). This high fluidity was related to alow cholesterol: phospholipid ratio and high triacylglycerol content in these lipoproteins. TGRLP from Cu-deficient rats were more susceptible to in vitro peroxidation than lipoproteins from control rats as shown by the rate of diene conjugation. The damage induced by the peroxidation resulted in a more ordered state of the lipid fraction especially in lipoproteins from Cu-deficient rats. Thus, after in vitro peroxidation, TGRLP from Cu-deficient rats were more rigid than those from controls. These results suggest that Cu deficiency induces modifications in physicochemical properties of TGRLP which could affect their metabolism.

1995 ◽  
Vol 269 (5) ◽  
pp. C1245-C1249 ◽  
Author(s):  
E. Rock ◽  
E. Gueux ◽  
A. Mazur ◽  
C. Motta ◽  
Y. Rayssiguier

This study was designed to make precise the nature and the mechanism of the anemia induced by dietary copper (Cu) deficiency. Male Wistar rats were pair fed from weanling for 6 wk either a Cu-deficient or a control diet. The reduced red blood cell (RBC) 51Cr survival indicates an increased destruction of RBC during Cu deficiency. 1,6-Diphenyl-1,3,5-hexatriene fluorescence polarization studies revealed an increase in the fluidity of erythrocyte membranes from deficient rats. The reduced cholesterol-to-phospholipid ratio was consistent with the increased fluidity. Other results indicate an increased vulnerability of RBC to hemolysis in dilute hydrogen peroxide and an increased formation of lipid peroxidation products. Before exposure to free radical stress, electron spin resonance studies in intact RBC revealed decreased correlation time of 16-doxyl-stearic acid, confirming a more fluid membrane in RBC from Cu-deficient rats. After in vitro peroxidation, RBC from Cu-deficient rats showed a more ordered state of membrane lipids compared with controls. Together, these studies demonstrate the hemolytic nature of the anemia. The shortened survival of erythrocytes apparently results from changes in membrane fluidity and enhanced susceptibility to peroxidation.


2018 ◽  
Vol 8 (5) ◽  
pp. 78-84
Author(s):  
Uyen Tran Thi Ngoc ◽  
Nam Nguyen Khac ◽  
Dung Tran Huu

Background: The purpose of the study was to prepare acetylated wheat starches which have amylase hydrolysis resistant capacity to use as functional food supporting for diabetes treatment. Method: Acetate wheat starches were prepared by acetylation reaction of native wheat starch with different mole ratios of acetic anhydride. These starches were determined for the physicochemical properties by 1H-NMR, SEM, X-ray, DSC, solubility and swelling capacity, the resistant capacity by amylase hydrolysis in-vitro. Results: Acetate wheat starches were prepared successfully with the increase in acetyl content and degree of substitution corresponding with the increase of anhydride acetic, which resulted in the change of physicochemical properties of the wheat starches, including constitution, solubility, swelling capacity and contributed to the increase in resistant starch content in the acetate wheat starches. The AC150-9 containing 2.42% acetyl with degree of substitution 0,094 and resistant starch 32,11% is acceptable by FDA guideline about food safety. Conclusion: Acetate wheat starches contain low rate of digestive starch, while containing a higher proportion of resistant starch than natural wheat starch, possessing a high resistance to amylase activities. Thus, it is hope that this kind of starch to control the rapid increase of postprandual blood glucose response for diabetes treatments effectively. Key words: Acetate wheat starch, substitution, DS, RS, amylase


2018 ◽  
Vol 18 (1) ◽  
pp. 10-15
Author(s):  
Wang Yi-Wei ◽  
He Yong-Zhao ◽  
An Feng-Ping ◽  
Huang Qun ◽  
Zeng Feng ◽  
...  

In this study, Chinese yam starch-water suspension (8%) were subjected to high-pressure homogenization (HPH) at 100 MPa for increasing cycle numbers, and its effect of on the physicochemical properties of the starch was investigated. Results of the polarizing microscope observations showed that the starch granules were disrupted (i.e. greater breakdown value) after HPH treatment, followed by a decrease in cross polarization. After three HPH cycles, the crystallinity of starch decreased, while the crystal type remained unaltered. Meanwhile, the contents of rapidly digestible starch and slowly digestible starch were increased. On the contrary, resistant starch content was decreased. Our results indicate that HPH treatment resulted in reduction of starch crystallinity and increase of starch digestibility.


Blood ◽  
1990 ◽  
Vol 76 (6) ◽  
pp. 1250-1255 ◽  
Author(s):  
S Whitehead ◽  
TE Peto

Abstract Deferoxamine (DF) has antimalarial activity that can be demonstrated in vitro and in vivo. This study is designed to examine the speed of onset and stage dependency of growth inhibition by DF and to determine whether its antimalarial activity is cytostatic or cytocidal. Growth inhibition was assessed by suppression of hypoxanthine incorporation and differences in morphologic appearance between treated and control parasites. Using synchronized in vitro cultures of Plasmodium falciparum, growth inhibition by DF was detected within a single parasite cycle. Ring and nonpigmented trophozoite stages were sensitive to the inhibitory effect of DF but cytostatic antimalarial activity was suggested by evidence of parasite recovery in later cycles. However, profound growth inhibition, with no evidence of subsequent recovery, occurred when pigmented trophozoites and early schizonts were exposed to DF. At this stage in parasite development, the activity of DF was cytocidal and furthermore, the critical period of exposure may be as short as 6 hours. These observations suggest that iron chelators may have a role in the treatment of clinical malaria.


Author(s):  
Niketa Chauhan ◽  
Nilay Lakhkar ◽  
Amol Chaudhari

AbstractThe process of bone regeneration in bone grafting procedures is greatly influenced by the physicochemical properties of the bone graft substitute. In this study, porous phosphate glass (PPG) morsels were developed and their physicochemical properties such as degradation, crystallinity, organic content, surface topography, particle size and porosity were evaluated using various analytical methods. The in vitro cytotoxicity of the PPG morsels was assessed and the interaction of the PPG morsels with Dental Pulp Stem Cells (DPSCs) was studied by measuring cell proliferation and cell penetration depth. The cell-material interactions between PPG morsels and a commercially available xenograft (XG) were compared. The PPG morsels were observed to be amorphous, biocompatible and highly porous (porosity = 58.45%). From in vitro experiments, PPG morsels were observed to be non-cytotoxic and showed better cell proliferation. The internal surface of PPG was easily accessible to the cells compared to XG.


2021 ◽  
Vol 52 (1) ◽  
Author(s):  
Hongfang Ma ◽  
Rui Li ◽  
Longguang Jiang ◽  
Songlin Qiao ◽  
Xin-xin Chen ◽  
...  

AbstractPorcine reproductive and respiratory syndrome (PRRS) is a serious disease burdening global swine industry. Infection by its etiological agent, PRRS virus (PRRSV), shows a highly restricted tropism of host cells and has been demonstrated to be mediated by an essential scavenger receptor (SR) CD163. CD163 fifth SR cysteine-rich domain (SRCR5) is further proven to play a crucial role during viral infection. Despite intense research, the involvement of CD163 SRCR5 in PRRSV infection remains to be elucidated. In the current study, we prepared recombinant monkey CD163 (moCD163) SRCR5 and human CD163-like homolog (hCD163L1) SRCR8, and determined their crystal structures. After comparison with the previously reported crystal structure of porcine CD163 (pCD163) SRCR5, these structures showed almost identical structural folds but significantly different surface electrostatic potentials. Based on these differences, we carried out mutational research to identify that the charged residue at position 534 in association with the one at position 561 were important for PRRSV-2 infection in vitro. Altogether the current work sheds some light on CD163-mediated PRRSV-2 infection and deepens our understanding of the viral pathogenesis, which will provide clues for prevention and control of PRRS.


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