共查询到20条相似文献,搜索用时 31 毫秒
1.
A Nakata M Hagita U Okamoto 《Nihon seirigaku zasshi. Journal of the Physiological Society of Japan》1978,40(11):419-426
When fibrinolytic activity in blood samples from various vessels was examined by the dilute-blood-clotlysis-time method (DBCLT), it was found to be noticeably high in the renal venous blood, though the activity was not detected by usual blood clotlysis time method. Plasmin was not detected in any blood samples examined, and the contents of fibrinogen and fibrin (or fibrinogen) breakdown products in the renal venous blood were not significantly different from those in the blood from other vessels. However, the high activity of plasminogen-activator was found only in the renal venous blood. Inhibitors on plasmin and plasminogen-activator (urokinase) were detected in almost the same amount in the blood samples from the various vessels. The amount of the inhibitors was sufficient to inhibit the plasminogen activation by urokinase, whose activity was equivalent to the plasminogen-activator activity in the renal venous blood. These results indicate that the high activity by DBCLT in the renal venous blood was derived from the high activity of plasminogen-activator, which was inactivated by inhibitors in undiluted blood. Plasminogen-activator may be released from the kidney to the blood, and immediately inactivated by the inhibitors in renal vein, and then diluted with systemic blood which contains little plasminogen-activator. 相似文献
2.
More than 50 studies have investigated the effect of altered sodium intake on blood pressure. A regression line drawn through the change in blood pressure and change in sodium intake indicates that blood pressure alters about 10 mmHg (1 mmHg = 133.322 Pa) for every 100 mmol/day alteration in sodium intake, a change similar to that observed in between-population "studies." The studies that have failed to show a change in blood pressure have usually been in people with a blood pressure less than 130/90 mmHg. Normotensive people appear to tolerate a higher intake of sodium before blood pressure rises, but if increased sufficiently, blood pressure rises in most people. Sodium restriction reduces blood pressure in people with severe hypertension, moderate hypertension and mild hypertension. It may be the cause of blood pressure increase associated with age and the reason for the higher prevalence of hypertension and vascular disease in Western communities. Sodium restriction should be used to treat people with elevated blood pressure. 相似文献
3.
P W Chun O M Rennert E E Saffen W J Taylor 《Biochemical and biophysical research communications》1976,69(4):1095-1101
At the physiological pH 7.4, the zeta potential of the normal red blood cell in 1.5% glycine buffer was found to be ?52 mv, whereas that of sickling erythrocytes is ?45 mv. Addition of spermidine to normal red blood cells reduced the zeta potential by approximately 20 mv. In sickling red blood cells, where the polyamine content is determined to be 5 to 6 times greater than in the normal erythrocyte, addition of spermidine reduced the zeta potential by only 5 mv, indicating that little more polyamine binding occurs. The polyamine content of whole blood taken from 24 patients having sickle cell anemia was found to be more than ten times that of whole blood from normal donors. Binding of polyamines to the normal red blood cell was analyzed from the surface charge potential variation as a function of polyamine concentration and the apparent binding constant determined to be 130 d1/g. The difference in the electrokinetic properties of normal and sickling red blood cells in this system may be attributed, in part, to a variation in the polyamine content of the two types of erythrocytes. 相似文献
4.
TYLER ET 《California medicine》1954,80(1):13-15
The one feature that characterizes all shock, regardless of its cause, is a reduction in the effective circulating blood volume. The reduced blood volume leads to decreased venous return, decreased cardiac output, vasoconstriction, tachycardia, hypotension, tissue anoxia and death if the sequence of events is uninterrupted. Immediate therapy must be directed at restoration of the blood volume, preferably with whole blood. Infection must be controlled by use of antibiotics intramuscularly and intravenously. If shock persists, aqueous adrenal extract should be administered in large quantities. As a last resort, a vasopressor should be tried. 相似文献
5.
W. Lohmann 《Radiation and environmental biophysics》1976,13(4):281-286
Summary Investigations of native blood of healthy people and of patients with acute leukemia have shown that the disease might be caused by a strongly reducing substance, which is presumably a virus. Evidence for this conclusion was obtained mainly by electron spin resonance (ESR) studies and by the determination of the catalase activity. ESR spectra of leukemic blood revealed an additional signal not present in spectra of healthy blood. Investigation of different blood fractions has shown that this signal is caused by a species present in the leukocytes only. Addition of reduced glutathione to healthy blood immediately after blood drawing resulted in the same signal. On the contrary, oxidizing substances, such as oxidized glutathione and KMnO4, added to the blood of leukemic patients immediately after its drawing, caused a disappearance of this signal depending on the concentration.Since the strongly reducing substance causes a reduction in the concentration of the oxidizing substances in biological systems, the H2O2 level should be also affected and, thus, the catalase activity, too. As expected, the activity of this enzyme in the leukemic blood seems to be considerably lower than in healthy blood. 相似文献
6.
An expression for oxidative potential (phi) of conservated blood is suggested proceeding from the assumption of the steady character of the system methemoglobin -- hemoglobin, oxihemoglobin included. This system is suggested to be responsible for the formation of phi in the blood. The equation qualitatively describes the experimental relation of phi on time at the contact of blood with air. Relationship between the changes of oxidative potential in the blood during its storage with the state of conservated blood hemoglobin is discussed. The experimental data show that measuring of the oxidative potential may be the basis for creating a control method for the state of conservated blood during its storage. 相似文献
7.
目的:分析三种自体输血方法在剖宫产手术中的可行性与易行性。方法:根据孕产妇的生理特点,分别对三种自体输血方法在应用中可能出现的问题及优缺点进行针对性的研究分析。结果:贮存式自体输血在操作时间上较灵活,贮血量较大,但环节较多,相对繁琐;稀释式自体输血极为契合产妇的生理特点,可提供血液贮备,也能促进机体组织细胞对氧的摄取和利用,但一次性采血量会有局限;回收式自体输血无需对产妇本身进行直接操作,患者相对容易接受,但由于回收血液可能会受到羊水和胎儿血液污染,在实际工作中应用很少。结论:三种自体输血方式各有利弊,但稀释式自体输血由于其简单易行且适合于产妇的生理特点,在剖宫产手术的应用中可行性更高。对于预计出血量极大的情况,可考虑两种或三种自体输血方式的联合应用。 相似文献
8.
Peter I. Lelkes Howard B. Tandeter 《Biochimica et Biophysica Acta (BBA)/General Subjects》1982,716(3):410-419
The stability of small unilamellar liposomes was investigated in human blood, in vitro. Using the carboxyfluorescein technique, interaction between the dye, the detergent Triton X-100, and an as yet unidentified component of human serum grossly interferes with the experiment and necessitates the use of other detergents, preferably sodium deoxycholate. Separation of liposomes and blood cells by centrifugation induces a small leakage from the liposomes and can lead to an underestimation of the real liposome stability. Upon incubation with whole blood, intact liposomes are absorbed nonspecifically to erythrocytes and internalized by leukocytes, the extent and kinetics of the former process being insenstive to the presence of metabolic inhibitors. The stability of liposomes is significantly enhanced in whole blood or in serum containing washed erythrocytes. Similarly, liposome stability in serum could be augmented be presaturating the serum lipoproteins with excess phospholipid. Our work adds support to previous notions that stable liposomes with high affinities for certain blood-cell components might be developed as suitable carrier systems for drug targetting in pathological disorders within the blood stream. 相似文献
9.
Hydroxychloroquine (HCQ) stereoselective distribution was investigated in rabbits after 20 mg/kg po of racemic-HCQ (rac-HCQ) and 20 mg/kg po of each enantiomer, 97% pure (?)-(R)-HCQ and 99% pure (+)-(S)-HCQ. Concentrations were 4 to 6 times higher in whole blood than in plasma. Melanin did not affect plasma and whole blood levels since concentrations did not differ between pigmented and nonpigmented animals. After single and multiple doses of the separate enantiomers, only 5–10% of the antipode could be measured, in blood or plasma. Therefore, there was no significant interconversion from one enantiomer into the other. Following rac-HCQ, plasma (+)-(S)-levels always surpassed (?)-(R)-ones while in whole blood, (?)-(R)-HCQ concentrations were always the highest. When the enantiomers were administered separately, blood concentrations achieved after (?)-(R)-HCQ were higher, especially after multiple doses. These observations suggest that (?)-(R)-HCQ is preferentially concentrated by cellular components of blood. This enantioselective distribution of HCQ could be secondary to a stereoselective protein binding to plasma proteins, although a more specific binding of (?)-(R)-HCQ to blood cells cannot be ruled out. Since in whole blood (?)-(R)-HCQ is retained in cellular components, metabolism would favour the more available (+)-(S)-enantiomer. © 1994 Wiley-Liss, Inc. 相似文献
10.
During the differentiation and maturation of erythrocytes, the surface molecules of erythrocytes are gradually expressed and stabilized. These molecules are to be antigenic in addition to their functions of maintain-ing cell membrane structural stability, material transport and exchange of cells and signal transmission between cells. The antigenic molecules on the erythrocyte surface are called erythrocyte blood group antigens. The blood group antigens and their corresponding blood group antibodies in vivo are important indicators for clinical blood transfusion and organ transplantation, and also form the basis for research on blood group related diseases. Three hundred and sixty-eight erythrocyte blood group antigens have been confirmed so far, which are classified into 39 blood group systems, 5 blood group collections and 2 blood group series. Based on the diversity of blood group antigens and their composition of glycolipids, glycoproteins and other molecules, this study mainly reviews the classification, molecular structure, antibody response and gene regulation of blood group antigens, and explains the main reasons for the diversity of blood group antigens. 相似文献
11.
F G Hall 《Journal of cellular physiology》1966,68(1):69-73
The effects of three physical-chemical factors, temperature, hydrogen ion concentration, and partial pressure of oxygen, on the respiratory functions of blood of the toad (Bufo marinus) have been studied. Measurements of oxygen affinity of hemoglobin in whole blood were measured tonometrically by a method devised for small quantities of blood. At pH 7.40 and 25°C blood was found to be 50% saturated with oxygen at a partial pressure of 44 mm Hg of oxygen. The Bohr effect was measured at various temperatures and found to be about one-half that found for mammalian blood. Carbon dioxide content of toad blood changes only slightly in the oxygenated and reduced states. Thus the “Haldane” effect parallels the small Bohr effect. Toad blood was found to have average hematocrit values of 37% for erythrocytes and average hemoglobin values of 11 gm/100 ml per cubic millimeter of blood. The respiratory functions of the blood of the toad conform to the pattern of respiratory mechanisms available for gas exchange between the environment and tissues of the organism. 相似文献
12.
T M Solomatina M N Volgarev L S Bassalyk N V Gromova 《Biulleten' eksperimental'no? biologii i meditsiny》1985,100(8):162-164
A study was made of the amount of Ec-cells in the small intestine mucosa and blood plasma serotonin of rats in health and fasting. It was established that 24 hours after food deprivation the amount of Ec-cells rises approximately 2-fold as compared with control. The cells demonstrate the intensification of the argentaffin reaction. The content of serotonin in blood plasma increases 2-fold accordingly. On day 3 of fasting the amount of Ec-cells and intensity of the argentaffin reaction decrease to normal, whereas the content of blood plasma serotonin does not change essentially. This may be linked with a massive release of serotonin to blood and depletion of Ec-cells because of which the threshold of their histochemical demonstration is reduced. On day 7 of food deprivation the amount of Ec-cells and the intensity of the argentaffin reaction increase again but the serotonin content dramatically falls down. This phenomenon may be related to the derangement of serotonin release to blood or to the transformation from the synthesis of serotonin to the synthesis of some other hormone, most likely melatonin. 相似文献
13.
Recent studies clearly demonstrate the respiratory importanceof the hemocyanins in each of the three animal phyla in whichthey occur. Despite their generally low oxygen affinity, hemocyaninscan be highly oxygenated at the site of gas exchange with themedium as well as deoxygenated at the tissues. The functionalrange of a hemocyanin oxygen transport system is severely limitedhowever by environmental change. These systems function underincipient hypoxia due largely to responses of blood pH whichare not fully understood a normal Bohr shift is accompaniedby a rise in blood pH and a reverse Bohr shift by a decreasein blood pH. In both instances blood oxygen affinity increasesand its oxygenation state at the gill remains high in spiteof its lower Po2. Dilution of the blood at low salinity generallyalters its oxygenation properties both oxygen affinity and cooperativity.These properties may or may not be restored by concomitant changesin blood pH, which depend on the various mechanisms of osmoticadaptation. Within a homogeneous taxon the oxygenation properties of a hemocyaninappear to be highly conservative showing little interspecificadaptation except to extreme changes in the mode of gas exchange.Unlike that in vertebrates air-breathing in crustaceans is accompaniedby an increase in blood oxygen affinity. Similar oxygen affinitiesin latitudinally separated species result in optimal functioningof the system at the same temperature, corresponding to differentseasons. In eurythermal species a temperature acclimation ofoxygen affinity extends the operating range of the crustaceanhemocyanins but they cannot deoxygenate at very low temperatures. Unsolved problems of hemocyanin function include specific effectsof pH and CO2 the basis of which is not entirely clear, andthe postulated occurrence in native blood of both dialyzableand non-dialyzable substances that modify oxygen affinity theidentity of which is unknown. With the exception of the crustacean oxygen carrier the hemocyaninsconfer a respiratory advantage over their predecessors. Butthe oxygen carrying capacity of crustacean blood never reachesthe levels found in the annelids and molluscs due to the colloidosmotic pressure of the relatively low molecular weight hemocyaninand to the drop in blood hydrostatic pressure accompanying theloss of a fluid skeleton. The selection of a blood oxygen carrierwith an apparently limiting combination of respiratory and osmoticproperties is obscured by the uncertain phylogenetic positionof the phylum. 相似文献
14.
H Marquordt-Schulze 《Folia haematologica (Leipzig, Germany : 1928)》1982,109(6):836-842
The development of the total amount of blood donations in the period from 1972-1980 was organized according to demand. With the percentage of blood from red cross donors increasing, blood donation attained a new quality which became evident in an increasing social recognition of donors coming from the red cross organization and which, above all, was characterized by its ethical-moral aspects. Further improvements could be achieved in organizing the preparation and establishment of fixed dates for blood donation. The demand for stored blood containing erythrocytes was ensured by an amount which lay below the international value of comparison. This, however, is taken as a basis for the future development of plasma demand. The increase of required plasma is effected by means of a plasmapheresis programme which still further is to be intensified. 相似文献
15.
B A Gould H A Kieso R Hornung D G Altman P M Cashman E B Raftery 《BMJ (Clinical research ed.)》1982,285(6356):1691-1694
Self-recording of the blood pressure by patients away from hospital or office ("home blood pressure") has been advocated as providing a better estimate of "true" blood pressure. The reliability of home blood-pressure recording has been assessed only by standard indirect methods which themselves are subject to considerable error and variability. The accuracy of self-recorded blood pressures was therefore assessed in 57 patients with essential hypertension by comparison with simultaneous measurements of clinic blood pressures and with intra-arterial blood pressures recorded at home and at hospital. Home systolic blood pressures showed good agreement with clinic and intra-arterial pressures, but home diastolic blood pressures overestimated intra-arterial pressures, as did clinic diastolic pressures. The clinic and home diastolic pressures showed good agreement. There was considerable variability in individual differences comparing the indirect and intra-arterial methods, though the two indirect methods showed much closer agreement. This study suggests that home blood pressures are as accurate as clinic readings but may be recorded more frequently and thus provide more useful information. Neither is likely to approximate the intra-arterial blood pressure. 相似文献
16.
During the differentiation and maturation of erythrocytes, the surface molecules of erythrocytes are gradually expressed and stabilized. These molecules are to be antigenic in addition to their functions of maintaining cell membrane structural stability, material transport and exchange of cells and signal transmission between cells. The antigenic molecules on the erythrocyte surface are called erythrocyte blood group antigens. The blood group antigens and their corresponding blood group antibodies in vivo are important indicators for clinical blood transfusion and organ transplantation, and also form the basis for research on blood group related diseases. Three hundred and sixty-eight erythrocyte blood group antigens have been confirmed so far, which are classified into 39 blood group systems, 5 blood group collections and 2 blood group series. Based on the diversity of blood group antigens and their composition of glycolipids, glycoproteins and other molecules, this study mainly reviews the classification, molecular structure, antibody response and gene regulation of blood group antigens, and explains the main reasons for the diversity of blood group antigens. 相似文献
17.
Estimation of the Life Span of Red Blood Cells in the Growing Animal in Different Nutritional States
In this study the model of Shemin and Rittenberg for estimating the life span of red blood cells was extended so that non-steady-state conditions, exemplified by growth or changing physiological states, might be considered. The parameters were estimated by use of the modified Gauss-Newton method. The biological data that were used came from growing sheep in different physiological states with regard to copper. The model was extended to include changes in total blood hemin and changes in blood hemin synthesis that may occur with time. In the present study a linear function was taken as a first approximation. The model appeared to be a sufficiently good approximation in the study reported herein. It was found, however, that the parameters associated with changes in hemin should be estimated from ancillary measurements such as blood volume, Hb, body weight, etc., in order to obtain a good fit or definition of the model. 相似文献
18.
DEATSCH WW 《California medicine》1956,84(3):180-184
A specific and characteristic type of anemia is not a feature of all malignant disease. To the contrary, the nature of the anemia will depend upon the causative mechanism, of which blood loss and accelerated erythrocyte removal appear to be the most frequently seen and the most clearly defined. Recognition of anemia due to loss of blood is relatively simple if the subtlety of blood loss in the stool is borne in mind and persistent testing to demonstrate it is carried out. Indeed, anemia characterized by chronic loss of blood in men can only mean chronic gastrointestinal bleeding if certain rare hemoglobin abnormalities can be ruled out. Anemia due to accelerated erythrocyte removal may also be recognized by simple measures. After transfusions raise hemoglobin values to near normal levels, the disappearance of the transfused blood and the rapid return of the pretransfusion severity of anemia are good evidence of the presence of such a mechanism, if blood loss can be ruled out.Adequate management of the anemia of malignant disease depends upon a clear understanding of the various mechanisms involved. It is highly probable that attention to this feature will, in many instances, significantly prolong the productive life of persons with malignant disease. 相似文献
19.
Splenectomy is found to be followed by an increase of the calcium level in blood. Administration of the spleen extract (splenin) decreases the calcium concentration in blood plasma of splenectomized animals. The normalizing splenin effect is observed in the presence of stress when the concentration of the studied trace element sharply increases as well. It is supposed that the humoral spleen factors participate in maintenance of the constant calcium level in blood preventing its elimination from tissues. 相似文献
20.
The UV-irradiated blood of healthy adults was supplemented with non-irradiated blood in the ratio 1:10. The phagocytic activity (PhA) of monocytes and granulocytes was seen to increase markedly in the whole mixture of blood. In this case the rise of PhA was pronounced 1.4-1.7 times as much as in the case of the non-supplemented, directly UV-irradiated blood. The enhancement of PhA depends on its initial level and may occur simultaneously with structural changes of the cell surface components. It seems reasonable to propose that PhA stimulation may be one of the earliest mechanisms in immunocorrection by UV-irradiated blood therapy. 相似文献