The determination of erythrocyte deformability using a filtration method]

Red cell deformability was assessed in donors, patients with chronic renal insufficiency, and with thermal injuries by filtration through special filters. Filtration of donor red cells decreased their count but insignificantly; in patients with chronic renal insufficiency this characteristic was lowered, particularly so before hemoperfusion, whereas after hemoperfusion red cell deformability improved. Changes of red cell deformability in patients with thermal injuries is an objective criterion reflecting the status of the erythron peripheral component in connection with the severity of injury and course of its healing.     

A new sensitive microassay for the measurement of erythrocyte glycogen

Conventional ethanol precipitation of sub-microgram amounts of glycogen leads to low yields (less than 50%). Quantitative recoveries of 90% were attained, however, when the isolation temperature was raised to 50 degrees C and ethanol was replaced by the less polar propan-2-ol. This improvement enabled development of an erythrocyte assay for glycogen which was both sensitive (0.1 microgram glycogen) and required only 1 ml of whole blood. 26 paediatric specimens were analysed and a reference range of values from undetected to 78 micrograms glycogen/g haemoglobin (Hb) was obtained.     

A method of determining erythrocyte deformability]

Red cell suspension filtration through synthetic filters is the most prevalent method for estimation of red cell deformability. A modified technique with the use of cellulose acetate filters manufactured by the Polimersintez Research and Production Amalgamation in the town of Vladimir is suggested. Employment of these filters will help introduce this test in clinical practice.     

A method of determining erythrocyte deformability]

A simple method for determining red cell deformability is suggested, based on red cell packing during centrifugation. This method was used to study red cell deformability in patients with essential hypertension and angina of effort and found it reduced.     

Analysis of factors regulating erythrocyte deformability.

Using a laser diffraction technique, we have studied factors that influence the deformability of erythrocytes. Variations in suspending medium osmolality and applied shear stress were employed to isolate the individual contributions to whole cell deformability of internal viscosity, surface area-to-volume ratio, and viscoelastic properties of the membrane. An experimental system was devised in which normal cells were modified in vitro to induce specific alterations in each factor. Measurements of deformability as a function of medium osmolality showed characteristic behavior of the modified cells. Reduced surface area-to-volume ratio was detected by an exaggeration of the normal decrease in deformability as medium osmolality was decreased. In contrast, increased internal viscosity was detected by an increase in deformability as osmolality was decreased. Finally, decreased membrane flexibility was detected by reduced deformation at low shear stress. These methods of analysis were applied to cells from patients with hereditary spherocytosis, hereditary pyropoikilocytosis, and hemoglobin CC disease to define the basis of reduced deformability. Hereditary spherocytes showed the combined effects of reduced surface area and increased internal viscosity. Hereditary pyropoikilocytes revealed the effects of severely reduced surface area-to-volume ratio. Hemoglobin CC cells showed only the effects of high internal viscosity. An increase in the membrane shear modulus (decreased membrane deformability) was not evident in these disorders.     

大面积烧伤患者早期红细胞膜胆固醇变化与红细胞变形性的关系

目的研究大面积烧伤患者早期红细胞膜胆固醇与红细胞变形指数的变化及意义。方法利用核孔滤膜法测量红细胞变形指数 ,使用化学修饰电极测量红细胞膜胆固醇。结果大面积烧伤患者早期与正常对照组比较红细胞变形指数显著下降 ,分别为 7.82 6± 0 .5 3及 6 .5 41± 0 .6 1,而红细胞膜胆固醇则显著升高 ,分别为(0 .6 45± 0 .0 6 2 ) mm ol/ g膜蛋白及 (0 .891± 0 .0 5 1) m mol/ g膜蛋白 (P<0 .0 1) ,且二者呈高度负相关 (r=- 0 .80 1)。结论红细胞膜胆固醇能够有效反映大面积烧伤患者早期红细胞变形能力 ,并成为反映大面积烧伤的早期微循环状态的新型量化指标     

大面积烧伤患者早期红细胞膜胆固醇变化与红细胞变形性的关系

目的研究大面积烧伤患者早期红细胞膜胆固醇与红细胞变形指数的变化及意义。方法利用核孔滤膜法测量红细胞变形指数,使用化学修饰电极测量红细胞膜胆固醇。结果大面积烧伤患者早期与正常对照组比较红细胞变形指数显著下降,分别为7.826±0.53及6.541±0.61,而红细胞膜胆固醇则显著升高,分别为(0.645±0.062)mmol/g膜蛋白及(0.891±0.051)mmol/g膜蛋白(P＜0.01),且二者呈高度负相关(r=-0.801)。结论红细胞膜胆固醇能够有效反映大面积烧伤患者早期红细胞变形能力,并成为反映大面积烧伤的早期微循环状态的新型量化指标。     

Assessment of orthostatic blood pressure: measurement technique and clinical applications

BACKGROUND: Orthostatic hypotension, a decline in erect blood pressure, is the result of an impaired hemodynamic response to an upright posture or a depletion intravascular volume. The measurement of orthostatic blood pressure can be done at the bedside and therefore is easily applied to several clinical disorders. Despite its usefulness, the measurement is often neglected, possibly because of confusion regarding the appropriate measurement technique and suitable application to patient care. METHODS: Pertinent recent medical literature was reviewed. RESULTS: The normal physiologic response to the assumption of an upright posture is a small drop in blood pressure and a slight rise in pulse rate. Orthostatic hypotension is detected by measurement of blood pressure in two or more body positions. An abnormal blood pressure response can be observed with disorders such as syncope, falling, intravascular volume depletion, and autonomic dysfunction; with the treatment of maladies such as hypertension and heart failure; and with the use of several medications. CONCLUSIONS: The measurement of orthostatic blood pressure is an essential clinical tool for the assessment and management of patients affected by common medical disorders.     

磁共振成像SENSE技术及其临床应用价值探讨

目的:探讨磁共振(MRI)SENSE技术的临床应用价值。方法:采用SENSE技术对腹部及心脏成像序列在不同增速因子下对73例患者实施MRI扫描,分析其应用价值。结果:SENSE技术可应用于大多数腹部及心脏成像序列,在保证图像质量的前提下,可大大提高扫描速度,尤其对屏气扫描及实时成像更有意义。通过缩短TSE及TFE序列的回波链长度,减少运动及敏感性伪影。结论:SENSE技术为MRI提供了一个新的自由度,临床应用范围十分广泛,是一种行之有效的提高MRI速度的技术方法。     

Polymerization of sickle cell hemoglobin at arterial oxygen saturation impairs erythrocyte deformability.

We have examined the filterability of sickle erythrocytes, using an initial-flow-rate method, to determine whether sufficient hemoglobin S polymer forms at arterial oxygen saturation to adversely affect erythrocyte deformability. The amount of intracellular polymer was calculated as a function of oxygen saturation to estimate the polymerization tendency for each of eight patients with sickle cell anemia (SCA). Progressive reduction of oxygen tension within the arterial range caused a sudden loss of filterability of SCA erythrocytes through 5-micron-diam pores at a critical PO2 between 110 and 190 mmHg. This loss of filterability occurred at a higher PO2 than did morphological sickling, and the critical PO2 correlated significantly (r = 0.844-0.881, P less than 0.01) with the polymerization tendency for each patient. Study of density-gradient fractionated cells from four SCA patients indicated that the critical PO2 of dense cells was reached when only a small amount of polymer had formed, indicating the influence of this subpopulation on the results obtained for unfractionated cells. Impairment of erythrocyte filterability at high oxygen saturation (greater than 90%) suggests that small changes in oxygen saturation within the arterial circulation cause rheological impairment of sickle cells.     

A protein anomaly in erythrocyte membranes of patients with Duchenne muscular dystrophy

Raman spectroscopic comparisons of erythrocyte membranes from 20 patients with Duchenne muscular dystrophy and 8 age-matched controls indicate a prominent and consistent protein anomaly in the patient samples. This was apparent in the following: (a) CH-stretching signals from control membranes reveal a thermotropic transition at 15.6 degrees C, attributable to a protein/lipid phase that is lacking in dystrophic membranes. (b) CH-stretching signals from control membranes also show a protein transition at 39 degrees C [pH 7.4] that is shifted to 45 degrees in dystrophic membranes. (c) A reduction in pH to 5.7 shifts this transition from 39 degrees C to 7 degrees C in normal membranes and from 45 degrees C to 24 degrees C in dystrophic membranes. (d) The Amide I/Amide III regions indicate a significant proportion of beta- structured peptide in dystrophic but not normal membranes. (e) Analysis of tyrosine signals indicates greater polar exposure of tyrosine hydroxyl groups in dystrophic vs normal membranes. All of the differences between dystrophic and normal membranes are highly significant (P less than 0.001).     

Sonohysterography: technique, endometrial findings, and clinical applications.

Transvaginal ultrasound-guided saline infusion sonohysterography (SHG) is a relatively new technique for evaluation of the uterine cavity. As new studies declare the clinical usefulness of this technique, SHG may quickly become part of the routine ultrasound evaluation of the female pelvis. In this article, the SHG procedure is described and normal findings are discussed. Common endometrial pathological findings such as atrophy, polyps, fibroids, hyperplasia, and carcinoma are reviewed. The newly touted roles of SHG for screening patients on long-term tamoxifen therapy and for evaluating patients with infertility are introduced. Finally, we present a practical ultrasound-based flow chart for the workup of menopausal and perimenopausal patients with abnormal uterine bleeding.     

The phospholipid spectrum of erythrocyte membranes in hemorrhagic fever with renal syndrome

The subjects of the study--patients with severe hemorrhagic fever with renal syndrome--were divided into two groups: those who were on hemodialysis, and those who were not. The study included evaluation of the phospholipid spectrum of erythrocyte membranes in the acute period and during recovery. The results revealed conformational shifts in the structure of the bilipid membrane layer, which were maximal during the acute phase of the disease, as well as less prominent and varied changes in the phospholipid spectrum during recovery. This allows determination of the terms of rehabilitation of the patients and substantiates administration of membrane stabilizers as a part of complex therapy of residual syndrome.     

Surface architectonics and erythrocyte deformability in patients with terminal stage of chronic kidney failure

Red cell deformability was examined in donors and patients with chronic renal insufficiency; the red cell surface architectonics before and after filtration was under study. The red cell ability to deformation was found reduced in the patients, the level of nontransitional prehemolytic forms of red cells increased, and the count of discoid cells reduced. These data permit assessing the red cell ability to deformation.