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1.
The effect of an intrinsic defect in the red cell and pronounced hypochromia on oxidative damage to RBC membrane lipids was compared in beta-thalassemia and iron deficiency anemia (IDA), which have a varied etiology but equivalent low hemogiobin content. The study was planned to correlate the etiology of the disorders to the severity of lipid imbalance and RBC hemolysis in membranes of both the conditions. Results indicated a fall of lysophosphatidylcholine(LPC), phosphatidylethanolamine(PE) and the unsaturated to saturated fatty acid ratio in both conditions, while phosphatidylcholine(PC) increased only in thalassemia. However, irrespective of the disease, sphingomyelin(SM), total cholesterol and phospholipid levels elevated and the hydrogen peroxide stress test indicated increased susceptibility of both pathologic RBCs to peroxidation. Present findings indicate that IDA and thalassemla, allow for considerable amounts of oxidative damage to membrane lipids, irrespective of their etiologles, and thus point hypochromia as an important contributor for inducing lipid imbalance and RBC hemolysis.  相似文献   

2.
Malaria infection is known to cause severe hemolysis due to production of abnormal RBCs and enhanced RBC destruction through apoptosis. Infected RBC lysis exposes uninfected RBC to the large amount of pro-oxidant molecules such as methemoglobin. Methemoglobin (MetHb) exposure dose dependently makes RBCs susceptible to osmotic stress and causes hemolysis. MetHb mediated oxidative stress in RBC correlated well with osmotic fragility and hemolysis. Interestingly, a reactive oxygen species (ROS) spike at 15 min was responsible for the observed effects on RBC cells. Two natural antioxidants N-acetyl cysteine and mannitol protected the RBC from MetHb-mediated defects, which clearly indicated involvement of oxidative stress in the process. MetHb due to its pseudo-peroxidase activity produces ROS in the external microenvironment. Therefore, classical peroxidase inhibitors were tested to probe peroxidase activity mediated ROS production with defects in RBCs. Clotrimazole (CLT), which irreversibly inactivates the MetHb (CLT-MetHb) and abolishes peroxidase activity, did not produce significant ROS outside RBC and was inefficient to cause osmotic fragility and hemolysis. Hence, initiating a chain reaction, MetHb released from ruptured RBC produces significant ROS in the external microenvironment to make RBC membrane leaky and enhanced hemolysis. Together data presented in the current work explored the role of MetHb in accelerated humorless during malaria which could be responsible for severe outcomes of pathological disorders.  相似文献   

3.
Hemolysis of erythrocytes from human and porcine blood was studied at different calcium chloride (CaCl2) concentrations (0.04–1.83 mM) and at a constant bilirubin concentration (72 mM). Although, human erythrocytes showed significant hemolysis (64%) at the highest CaCl2 concentration (1.83 mM) used in this study, remarkable resistance to this phenomenon was observed with porcine erythrocytes as only 11% hemolysis was observed. A similar pattern in the behavior of both human and porcine erythrocytes was observed when parameter such as bilirubin concentration or time of incubation with bilirubin was varied. Other divalent cations such as Mn2+, Ba2+ and Mg2+ were either least effective or ineffective in inducing hemolysis in presence of bilirubin. Serum albumin played a protective role in this phenomenon in a concentration dependent manner, as no hemolysis was observed at a bilirubin/albumin molar ratio of 1:1 or less. Differences in the structural make-up of proteins and lipids in the erythrocyte membranes of the two species may account for their different behavior.  相似文献   

4.
Cryopreservation of human red blood cells (RBCs) in the presence of 40% glycerol allows a shelf-life of 10 years, as opposed to only 6 weeks for refrigerated RBCs. Nonetheless, cryopreserved blood is rarely used in clinical therapy, in part because of the requirement for a time-consuming (∼1 h) post-thaw wash process to remove glycerol before the product can be used for transfusion. The current deglycerolization process involves a series of saline washes in an automated centrifuge, which gradually removes glycerol from the cells in order to prevent osmotic damage. We recently demonstrated that glycerol can be extracted in as little as 3 min without excessive osmotic damage if the composition of the extracellular solution is precisely controlled. Here, we explore the potential for carrying out rapid glycerol extraction using a membrane-based microfluidic device, with the ultimate goal of enabling inline washing of cryopreserved blood. To assist in experimental design and device optimization, we developed a mass transfer model that allows prediction of glycerol removal, as well as the resulting cell volume changes. Experimental measurements of solution composition and hemolysis at the device outlet are in reasonable agreement with model predictions, and our results demonstrate that it is possible to reduce the glycerol concentration by more than 50% in a single device without excessive hemolysis. Based on these promising results, we present a design for a multistage process that is predicted to safely remove glycerol from cryopreserved blood in less than 3 min.  相似文献   

5.
Oxidative stress is implicated in the etiopathogenesis of a variety of human diseases. Therefore, in the present study, erythrocyte lipid peroxidation, percentage hemolysis, antioxidant enzymes viz., glutathione reductase, glutathione peroxidase, superoxide dismutase and plasma antioxidants viz., ceruloplasmin, vitamins A,E and C have been determined in 19 patients with tubercular meningitis (TBM) and 50 normals. Six patients who were treated with antibiotics were considered for the follow up. The statistical analysis was carried out by Mann Whitney U test and Wilcoxon rank sum test. Lipid peroxidation (P<0.02), percentage hemolysis (P<0.001) and plasma ceruloplasmin (P<0.0001) of TBM patients were significantly higher, whereas erythrocyte glutathione reductase (P<0.05) and plasma antioxidant vitamins A, E and C (P<0.01, P<0.05 respectively) were significantly lower than those of the controls. In the follow up patients the glutathione reductase and catalase levels were significantly high (P<0.05) compared to their pre-treated condition. Vitamin C and E levels have attained normal range. This study indicated that the blood antioxidant status of TBM patients which was low compared to controls improved after treatment, suggesting the role of free radicals in TBM.  相似文献   

6.
In this study it was planned to investigate the effect of oxidized phosphatidylcholine (derived from egg) feeding on lipid peroxidation of different tissues in rats. Male Wistar albino rats were fed oxidized and unoxidized phosphatidylcholine for 2 and 4 weeks, respectively. During the period of study food intake and body weights of animals increased gradually. Animals fed oxidized phosphatidylcholine for 2 and 4 weeks showed 33 and 15% spontaneous hemolysis of red blood cells in vitro. Under identical experimental conditions animals given unoxidized phosphatidylcholine showed 14.5 and 13.4% hemolysis for 2 and 4 week’s period, respectively. Thiobarbituric acid reactive substances (TBARS) level in thymus, spleen, kidney, heart, liver and lung significantly increased in rats given oxidized phosphatidylcholine as compared to unoxidized group. Furthermore, in oxidized phosphatidylcholine group TBARS values in kidney, liver and lungs continued to rise for 4 weeks of treatment while TBARS level in heart, spleen and thymus was found to be decreased at the end of 4 weeks of oxidized phosphatidylcholine feeding. Plasma triacylglycerol and cholesterol was found to increase in rats who had received oxidized phosphatidylcholine for 2 weeks. These findings suggest that excess and persistent intake of oxidized phosphatidylcholine can cause significant damage to organs.  相似文献   

7.
The aim of this study was to evaluate the radioprotective effect of turmeric extract (40 mg/kg body weight) and vitamin E (α- tocopherol acetate, 400 IU/kg body weight) supplementation on lipid peroxidation, reduced glutathione and antioxidant defense enzymes in various organs like liver, kidney and salivary glands at 24 h in adult Swiss mice. 131Iodine exposure significantly increased lipid peroxidation in kidney and salivary glands in comparison to control animals. Pre supplementation with turmeric extract for 15 days showed significant lowering of lipid peroxidation in kidney. On the other hand vitamin E pre supplementation showed marked reduction in lipid peroxidation in salivary glands. Reduced glutathione levels decreased significantly in liver after radiation exposure. However, pre supplementation with turmeric extract and vitamin E did not improve glutathione levels in liver. In conclusion, we have observed differential radioprotective effect of turmeric extract and vitamin E in kidney and salivary glands. However, Vitamin E seems to offer better radioprotection for salivary glands which is known to be the major site of cellular destruction after radioiodine therapy in patients.  相似文献   

8.
The buffering effect of acetate on hydrogen production during glucose fermentation by Ethanoligenens harbinense B49 was investigated compared to phosphate, a widely used fermentative hydrogen production buffer. Specific concentrations of sodium acetate or phosphate were added to batch cultures, and the effects on hydrogen production were comparatively analyzed using a modified Gompertz model. Adding 50 mM acetate or phosphate suppressed the hydrogen production peak and slightly extended the lag phase. However, the overall hydrogen yields were 113.5 and 108.5 mmol/L, respectively, and the final pH was effectively controlled. Acetate buffered against hydrogen production more effectively than did phosphate, promoting cell growth and preventing decreased pH. At buffer concentrations 100–250 mM, the maximum hydrogen production was barely suppressed, and the lag phase extended past 7 h. Therefore, although acetate inhibits hydrogen production, using acetate as a buffer (like phosphate) effectively prevented pH drops and increased substrate consumption, enhancing hydrogen production.  相似文献   

9.
The mechanical properties of red blood cells (RBCs) are critical to the rheological and hemodynamic behavior of blood. Although measurements of the mechanical properties of RBCs have been studied for many years, the existing methods, such as ektacytometry, micropipette aspiration, and microfluidic approaches, still have limitations. Mechanical changes to RBCs during storage play an important role in transfusions, and so need to be evaluated pre-transfusion, which demands a convenient and rapid detection method. We present a microfluidic approach that focuses on the mechanical properties of single cell under physiological shear flow and does not require any high-end equipment, like a high-speed camera. Using this method, the images of stretched RBCs under physical shear can be obtained. The subsequent analysis, combined with mathematic models, gives the deformability distribution, the morphology distribution, the normalized curvature, and the Young''s modulus (E) of the stored RBCs. The deformability index and the morphology distribution show that the deformability of RBCs decreases significantly with storage time. The normalized curvature, which is defined as the curvature of the cell tail during stretching in flow, suggests that the surface charge of the stored RBCs decreases significantly. According to the mathematic model, which derives from the relation between shear stress and the adherent cells'' extension ratio, the Young''s moduli of the stored RBCs are also calculated and show significant increase with storage. Therefore, the present method is capable of representing the mechanical properties and can distinguish the mechanical changes of the RBCs during storage. The advantages of this method are the small sample needed, high-throughput, and easy-use, which make it promising for the quality monitoring of RBCs.  相似文献   

10.
Daily feeding of drinking water containing lead acetate (160 mg/l) or 10% alcohol by volume or a combination of both to rats for a month produced certain deleterious effects through oxidative stress. Both heavy metal lead and alcohol are capable of doing such damages. The deleterious alterations observed were in the parameters of blood, serum and tissues, viz; Hb, Pb, proteins, lipids, lipid per oxidation, Vitamins C and E levels and enzyme activities of AST, ALT, and catalase. Simultaneous feeding of either of the two antioxidants garlic oil (GO) and vitamin E at equal doses of 100 mg/kg/day, to the rats counteracted the deleterious effects of the above two chemicals significantly. The maximum damage was brought about by feeding of drinking water containing both lead acetate and alcohol. The protective effects of GO and Vitamin E were not significantly different. The mechanism of actions of the Vitamin E and GO is probably due to their efficiency as detoxifying agents and antioxidants, to scavenging free radicals as well as an independent action of GO on the removal of lead salt as lead sulfide.  相似文献   

11.
静脉输血是学生必须掌握的“三基”内容之一,是从事临床护理工作的基础,而溶血反应是最严重的输血反应[1],严重时可导致死亡。在教学中,无法还原真实的溶血反应现场,学生在生活中也只是听说过溶血反应,且其发生机制抽象[2]。该文合理利用信息化教学手段,从教学分析、教学策略、教学过程、教学反思四个方面进行探讨。  相似文献   

12.
We show, via three-dimensional immersed-boundary-finite-element-lattice-Boltzmann simulations, that deformability-based red blood cell (RBC) separation in deterministic lateral displacement (DLD) devices is possible. This is due to the deformability-dependent lateral extension of RBCs and enables us to predict a priori which RBCs will be displaced in a given DLD geometry. Several diseases affect the deformability of human cells. Malaria-infected RBCs, for example, tend to become stiffer than their healthy counterparts. It is therefore desirable to design microfluidic devices which can detect diseases based on the cells'' deformability fingerprint, rather than preparing samples using expensive and time-consuming biochemical preparation steps. Our findings should be helpful in the development of new methods for sorting cells and particles by deformability.  相似文献   

13.

Introduction

This study aimed to assess confidence level of healthcare professionals in venipuncture and their knowledge on the possible causes of in vitro hemolysis.

Materials and methods

A sample of 94 healthcare professionals (nurses and laboratory technicians) participated in this survey study. A four-section questionnaire was used as a research instrument comprising general information for research participants, knowledge on possible causes of in vitro hemolysis due to type of material used and venipuncture technique and specimen handling, as well as assessment of healthcare professionals’ confidence level in their own ability to perform first and last venipuncture.

Results

The average score on the knowledge test was higher in nurses’ than in laboratory technicians (8.11 ± 1.7, and 7.4 ± 1.5, respectively). The difference in average scores was statistically significant (P = 0.035) and Cohen’s d in the range of 0.4 indicates that there is a moderate difference on the knowledge test among the health care workers. Only 11/94 of healthcare professionals recognized that blood sample collection from cannula and evacuated tube is method which contributes most to the occurrence of in vitro hemolysis, whereas most risk factors affecting occurrence of in vitro hemolysis during venipuncture were recognized. There were no significant differences in mean score on the knowledge test in relation to the confidence level in venipuncture (P = 0.551).

Conclusion

Confidence level at last venipuncture among both profiles of healthcare staff was very high, but they showed insufficient knowledge about possible factors affecting hemolysis due to materials used in venipuncture compared with factors due to venipuncture technique and handling of blood sample.Key words: hemolysis, patient safety, phlebotomy, medical staff, questionnaire, preanalytical phase  相似文献   

14.
In microcirculation, red blood cells (RBCs) flowing through bifurcations may deform considerably due to combination of different phenomena that happen at the micro-scale level, such as: attraction effect, high shear, and extensional stress, all of which may influence the rheological properties and flow behavior of blood. Thus, it is important to investigate in detail the behavior of blood flow occurring at both bifurcations and confluences. In the present paper, by using a micro-PTV system, we investigated the variations of velocity profiles of two working fluids flowing through diverging and converging bifurcations, human red blood cells suspended in dextran 40 with about 14% of hematocrit level (14 Hct) and pure water seeded with fluorescent trace particles. All the measurements were performed in the center plane of rectangular microchannels using a constant flow rate of about 3.0 × 10−12 m3/s. Moreover, the experimental data was compared with numerical results obtained for Newtonian incompressible fluid. The behavior of RBCs was asymmetric at the divergent and convergent side of the geometry, whereas the velocities of tracer particles suspended in pure water were symmetric and well described by numerical simulation. The formation of a red cell-depleted zone immediately downstream of the apex of the converging bifurcation was observed and its effect on velocity profiles of RBCs flow has been investigated. Conversely, a cell-depleted region was not formed around the apex of the diverging bifurcation and as a result the adhesion of RBCs to the wall surface was enhanced in this region.  相似文献   

15.
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16.
An unexpected increase in erythrocyte osmotic resistance during viral hepatitis in two patients prompted study of effects of hepatitis (in Karad) on osmotic resistance. The test was performed by placing erythrocytes in saline solutions of decreasing osmolarity and osmotic fragility defined in terms of the saline concentration at which hemolysis begins. Study included 44 infected subjects (acute viral hepatitis non-A non-B). All forty four infected subjects showed abnormal results when compared to normal subjects. increased erythrocyte osmotic resistance i.e. hemolysis begins between 0.45% to 0.40% of NaCl and is completed between 0.25% to 0.20% NaCl, whereas in normal subjects. hemolysis begins between 0.50% to 0.45% NaCl and is completed between 0.35% to 0.30% NaCl. Osmotic resistance was observed with increase in total bilirubin (mean±SD) (4.6 ±3.6), direct bilirubin (3.0±2.5), SGOT (58.8±55.5) SGPT (114.2±150.3) activity. Physiologic shifts in erythrocyte osmotic resistance may be due to changes in membrane lipid ratio.  相似文献   

17.
Cholinesterases belongs to class hydrolases. There are two types acetylcholinesterase and butyryl cholinesterase. Acetylcholinesterase present in nerve endings and also in the RBC membrane. It helps to maintain the shape and size of RBCs. Any change in shape and size of RBCs may affect the activity of Acetylcholinesterase. Thus this study aimed to estimate RBCs Acetylcholinesterase enzyme activity in various types of anemias and correlate the RBCs Acetylcholinesterase enzyme activity with various hematological indices such as Erythrocyte Sedimentation Rate (ESR), Mean Corpuscular Hemoglobin (MCH), Mean Corpuscular Hemoglobin Concentration (MCHC), Mean Corpuscular Volume (MCV), Red cell Distribution Width (RDW) etc. After obtaining ethical approval from Institutional ethics committee total of 100 samples were collected from Clinical Biochemistry laboratory, Kasturba Medical College, Manipal, Manipal University. 25 were having normal RBC indices, 12 with hemolytic anemia, 26 with microcytic anemia and 26 with macrocytic anemia based on peripheral smear report and RBC indices. Acetylcholinesterase were measured using Ellman’s method. RBC acetylcholinesterase activity was significantly increased in microcytic anemia (58.13 ± 5.4) and macrocytic anemia (76.87 ± 6.7) than normal group (37.62 ± 2.71). Also increased RBC acetylcholinesterase was seen in hemolytic anemia (48.11 ± 5.18) but the increase is not statistically significant. RBC acetylcholinesterase correlated negatively with hemoglobin (r = ?0.356, p = 0.001) and positively with RDW (r = 0.31, p = 0.003). To conclude RBC acetylcholinesterase activity can be used as one of the potential marker for various types of anemia.  相似文献   

18.
Cataract is one of the leading causes of visual disability often leading to blindness in the elderly population. One of the causes is oxidation of proteins present in lens, by hydrogen peroxide (H2O2). In the present study 100 goat lenses were analyzed to determine the protective efficacy of ketoacids, against the oxidative insult by H2O2. The ketoacids used were (pyruvate, alpha ketoglutarate and oxaloacetate), that are constantly produced endogenously. The lenses were incubated as control and experimental groups in TC-199 media for 72 hrs. H2O2 concentration of 10mM was used to induce cataract. The biochemical parameters measured were levels of malondialdehyde (MDA), a lipid peroxidation product and activity of glutathione peroxidase (G-Px), an enzymatic antioxidant. The results showed a significant increase in the levels of MDA and significant decrease in the activity of G-Px in the cataractous lenses as compared to control. After addition of ketoacids (pyruvate (10mM), alpha ketoglutarate (20mM) and oxaloacetate (20mM)) separately, the levels of MDA decreased significantly and the activity of G-Px increased significantly. The results suggest that the ketoacids can be very promising antioxidants for the treatment of cataract. They may also be useful in treating other disabilities related to acute and chronic oxidative stress.  相似文献   

19.

Background

Due to the high prevalence of hemolysis in specimens received from the emergency department (ED), several strategies have been proposed to improve sample quality, but none of these seem effective to overcome the problem. In a preliminary study we showed that the use of S-Monovette blood collection system was effective to lower the risk of hemolysis in venous blood samples collected from intravenous catheters. This study was hence aimed to verify whether the replacement of a conventional vacuum system with S-Monovette may be effective to reduce the burden of hemolysis in the daily practice of a large urban ED.

Materials and methods

The study was divided in two observational periods of 4 months each. In the former period, blood was collected from intravenous catheters using BD Vacutainer SST II Plus plastic serum tubes, whereas in the latter period the blood was drawn from intravenous catheters using S-Monovette blood tubes in aspiration mode. Sample hemolysis was automatically assessed in all serum samples by photometrical measurement.

Results

The total number of hemolysed serum specimens was 624/14155 (4.41%) in the first phase of the study, and 342/13319 (2.57%) in the second phase of the study (P < 0.001).

Conclusion

Results of our study confirm that the introduction of the Sarstedt S-Monovette blood tubes has reduced the hemolysis rate in the emergency department compared to the previously used BD Vacutainer® SST II Plus plastic serum tubes.Key words: preanalytical phase, hemolysis, blood specimen collection, catheter, emergency department  相似文献   

20.
为了研究4条人工合成抗菌肽的抑菌和溶血作用。在大肠杆菌悬浮液和绵羊血红细胞悬浮液中,分别加入不同溶度的人工合成抗菌肽,观察其抑菌效果和溶血作用。同时,用圆二色谱仪测定抗菌肽的二级结构。在4条人工合成抗菌肽中,抗菌肽CM-S的抑菌效果为最佳,最小抑菌溶度为25μg/mL,而LB平板菌落的杀菌溶度为50μg/mL;在对绵羊血红细胞的溶血试验中,CM-S在50μg/mL时无溶血作用,100μg/mL时只表现出轻微溶血特性;用圆二色谱仪测定CM-S的二级结构,在2.5%SDS溶液中,208 nm和222 nm出现典型α-螺旋特征峰。人工合成抗菌肽CM-S,含有17个氨基酸,呈典型α-螺旋结构,对大肠杆菌的抑杀效果显著,且溶血性很低,有良好的临床药物开发前景。  相似文献   

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