Screening for beta thalassaemia and HbE traits with the mean red cell volume in pregnant women

Both beta thalassaemia and HbE disease are microcytic red cell disorders. Pregnancy however induces macrocytosis which makes screening with the mean cell volume (MCV) difficult in antenatal patients. In addition, population screening for HbE has not been widely reported in the literature and the screening criteria for beta thalassaemia may not necessarily apply. A study of the value of the MCV for routine screening for both beta thalassaemia and HbE traits in 3696 antenatal patients of different gestational ages was carried out. All patients with an MCV < or = 80 fL received confirmatory tests for haemoglobinopathies. The MCV rose by only 2.0% in pregnancy. A total of 494 patients (13.4% of the general population) had an MCV < or = 80 fL. Of these microcytic patients, 11.3% (56) and 4.7% (23) were eventually confirmed to have beta thalassaemia and HbE traits respectively. The mean MCV for the 3696 antenatal patients was 87.8 fL (SD 7.5) compared to patients with beta thalassaemia and HbE traits, which were 67.5 fL (SD 4.5) and 75.7 fL (SD 4.1). HbE traits were less microcytic than beta thalassaemia traits and overlapped significantly with the general population. Beta thalassaemia trait and HbE trait detected by this screening method constituted 1.52% and 0.62% respectively of the total antenatal population screened. The MCV remains a valid screening parameter in pregnancy for beta thalassaemia trait. As for HbE trait, applying a discriminant value of 80 fL to the MCV in the population screening would miss a significant proportion of the HbE traits.(ABSTRACT TRUNCATED AT 250 WORDS)     

Interaction of hemoglobin with red blood cell membranes as shown by a fluorescent chromophore

Hemoglobin quenching of the fluorescence intensity of 12-(9-anthroyl)stearic acid (AS) embedded in the red blood cell membrane occurs through an energy transfer mechanism and can be used to measure the binding of hemoglobin to the membrane. The binding of hemoglobin to red cell membranes was found to be reversible and electrostatic in nature. Using a theory of energy transfer based on F?rster formulation, the quantitative data for the binding were derived. The number of binding sites was found to be 1.4 +/- 0.2 X 10(6) molecules per cell and the binding constant was 0.85 X 10(8) M-1.     

Photodynamic modification of proteins in human red blood cell membranes, induced by protoporphyrin

Illumination of erythrocytes or erythrocyte membranes with visible light in the presence of protoporphyrin causes photodynamic damage of the cell membrane. This process is reflected a.o. by a mutilated ultrastructure and changes of the physical properties of the membrane proteins. Illumination in the presence of protoporphyrin causes association of membrane proteins, leading to blurring of the protein bands in electropheretograms, disappearance of bands and the appearance of protein aggregates on top of the gels. The formation of large protein aggregates is also indicated by Sephadex gel filtration of the solubilized membrane proteins. In kinetic studies it appeared that spectrin and the bands 2.1, 2.2, 2.3 and 6 are most susceptible and that band 3 is least susceptible to this cross-linking reaction. Experimental results indicate that this cross-linking is caused by direct photooxidation of membrane proteins. Peroxidation of unsaturated fatty acids is not involved in the process. The significance of this process for studies on membrane structure and on photodynamic membrane damage is discussed.     

The structural status of red blood cell membranes in children with insulin-dependent diabetes mellitus. Examination by spin probe

For her 40th birthday, Ann O'Hanlon of Saddlebrook gave herself and her family a present: a complete physical. But Mrs. O'Hanlon, who always had experienced heart palpitations, or as she puts it, "a racy heart," did not fare well. She did have an inkling something wasn't quite right. At home she was finding it increasingly difficult to raise her arms or lift her legs. But she had no idea how bad the situation was or was to become.     

Smoking and blood pressure patterns in normotensive pregnant women

The cardinal clinical manifestations of major depression with melancholic features include sustained anxiety and dread for the future as well as evidence of physiological hyperarousal (e.g., sustained hyperactivity of the two principal effectors of the stress response, the corticotropin-releasing-hormone, or CRH, system, and the locus ceruleus-norepinephrine, or LC-NE, system). Sustained stress system activation in melancholic depression is thought to confer both behavioral arousal as well as the hypercortisolism, sympathetic nervous system activation, and inhibition of programs for growth and reproduction that consistently occur in this disorder. Data also suggest that activation of the CRH and LC systems in melancholia are involved in the long-term medical consequences of depression such as premature coronary artery disease and osteoporosis, the two-three-fold preponderance of females in the incidence of major depression, and the mechanism of action of antidepressant drugs. In addition, recent data reveal important bidirectional interactions between stress-system hormonal factors in depression and neural substrates implicated in many discrete behavioral alterations in depression (e.g., the medial prefrontal cortex, important in shifting affect based on internal and external cues, the mesolimbic dopaminergic reward system, and the amygdala fear system). We have also advanced data indicating that the hypersomnia, hyperphagia, lethargy, fatigue, and relative apathy of the syndrome of atypical depression are associated with concomitant hypofunctioning of the CRH and LC-NE systems. These data indicate the need for an entirely different therapeutic strategy than that used in melancholia for the treatment of atypical depression, and they suggest that this subtype of major depression will be associated with its own unique repertoire of long-term medical consequences.     

Omega-3 polyunsaturated fatty acid levels in the diet and in red blood cell membranes of depressed patients

The objective of this study was to clarify the possible angiogenesis-promoting factors from human trophoblasts in early stage gestation. The existence of angiogenic growth factors such as basic fibroblast growth factor (bFGF) and vascular endothelial growth factor (VEGF) in the condition medium from human villous trophoblasts was determined. Biological activity of angiogenic growth factors released by trophoblasts was examined using vascular endothelial cell lines. The condition medium from trophoblasts enhanced the growth of endothelial cells. Although cultured trophoblasts exhibited immunoreactive products for both bFGF and VEGF in the cytoplasm, only bFGF was detected in the condition medium by ELISA. The growth-enhancing activity of the condition medium was eliminated completely by the addition of anti-bFGF antibody but not with anti-VEGF antibody. Thus, trophoblastic cells seem to play an important role in extensive angiogenesis occurring in early gestation, mainly by releasing bFGF but not VEGF.     

Magnesium and calcium level in blood serum of pregnant women with pregnancy threatening miscarriage

Concentration of magnesium and calcium was determined in the blood serum of 43 women with pregnancy threatening miscarriage and 32 ones with normal uterine pregnancy in the time interval from 6th to 22nd week. I spite of considerable oscillations in magnesium concentration, particularly in the group of threatened pregnancies as compared with the normal ones, the differences were not significant. Neither were there found any significant differences in calcium concentration between the populations tested.     

Current red blood cell transfusion practices

The appropriate use of blood transfusions remains variable among health-care institutions and patient populations. Transfusion practices are discussed in this article in relation to medical practice guidelines and utilization review. Specific transfusion practices in the settings of intensive care, orthopedic surgery, and open heart surgery are reviewed. A new, promising approach to improving transfusion outcomes is the use of transfusion algorithms. Transfusion algorithms may prove especially useful if they incorporate point-of-care testing that is both physiologic and patient-specific for transfusion decisions. Transfusion algorithms are discussed and data presented for cardiac surgical adults.     

Activation of human polymorphonuclear leukocytes by products derived from the peroxidation of human red blood cell membranes

Oxidation of red blood cell (RBC) ghost preparations initiated by tert-butyl hydroperoxide (tBuOOH) was employed to explore the formation of lipid products derived from endogenous phospholipids that specifically expressed biological activity toward the human polymorphonuclear leukocyte (PMN). Common measure of lipid peroxidation, thiobarbituric acid-reactive substances (TBARS) and the increased absorbance at 235 nm consistent with the formation of conjugated dienes, was observed following a 90-min incubation of RBC ghosts with tBuOOH. Saponification of phospholipids and separation of the resultant fatty acids by RP-HPLC permitted direct mass spectrometric analysis of oxidized fatty acids. Individual HPLC fractions were assayed for their ability to increase intracellular free calcium ion concentrations in human PMN to guide structural investigations. Two fractions were found to contain biologically active components, and tandem mass spectrometric analysis of the abundant ions observed in these fractions resulted in the characterization of several oxidized polyunsaturated fatty acids derived from arachidonic and linoleic acids. The major components in these fractions included 5-hydroxyeicosatetraenoic acid (5-HETE) and 5-hydroperoxyeicosatetraenoic acid (5-HpETE). The dose-dependent increases in intracellular calcium in the neutrophil using synthetic 5(rac)-HETE, 5(rac)-HpETE, and 5-oxo-ETE were found to have EC50's of 250, 6, and 3 nM, respectively. The quantity of 5-oxygenated arachidonate components present in oxidized RBC was consistent with the observed biological response elicited by fractions A and B. This study suggests that 5-HETE and 5-HpETE are abundant products of lipid peroxidation of cellular membranes and that these racemic products possess significant biological activity. Such compounds could play important roles as mediators of the cellular response to toxicologic stimuli that generate free radical species.     

Bone-marrow imaging in pure red blood cell aplasia

Bone-marrow scintigraphy with indium chloride in 111 was performed on a patient with pure red blood cell aplasia before and after successful treatment with immunosuppressive drugs. The return of erythroid precursors to the bone marrow was accompanied by a substantial increase in the marrow uptake of 111In. The distribution of 111In in the posttreatment scan was indistinguishable from that of 52Fe. These results indicate that indium chloride in 111 is a useful agent for the delineation of erythroid cellularity within bone marrow.     

The mechanism of chlorpromazine-induced red blood cell swelling

1. Chlorpromazine (CPZ)-induced red blood cell (RBC) swelling was investigated by determination of electrolyte, mean cell volume (MCV) and water content changes in CPZ-treated cells. 2. CPZ-induced RBC swelling is dose-, hematocrit- and pH-dependent, and is associated with a net increase in RBC monovalent cation and Cl- contents. 3. The partition coefficient (Kp) for the CPZ-RBC membrane interaction is pH dependent (Kp = 2500 at pH 7.8; Kp = 840 at pH 6.8). 4. Despite the pH dependence of Kp values an equal number of CPZ molecules is required to induce a 12% increase in MCV at pH 7.8 and 6.8.     

Early post-radiation changes of red blood cell shape in rats

Scanning electron microscopy (SEM) of red blood cells in whole blood samples from rats was performed following acute gamma-irradiation of animals with 0.25 to 1 Gy. Increased incidence of echinocytosis was observed and found to be dose- and time-dependent. At a higher radiation dose (1 Gy), echinocytosis was revealed within 5 minutes after treatment and persisted up to 3 weeks. The data demonstrate the applicability of SEM for detecting minimal radiation-induced lesions of red blood cells.     

Normal variation in cutaneous blood content and red blood cell velocity in humans

This study was designed to determine normal variations in cutaneous blood content, red blood cell content and skin thickness in healthy human volunteers. The blood content (BC) of human skin and the velocity of red blood cells (RBV) has been comprehensively mapped over 30 anatomical sites in 28 volunteers between the age of 7 and 77 years using reflectance spectrophotometry (RFS) and laser Doppler (LD) techniques respectively. Total skin thickness, which may have a relationship with blood content, has been mapped at the same anatomical sites in six of the volunteers using two-dimensional array, 12 MHz ultrasound equipment. The major determinant of BC and RBV was found to be anatomical site. Regardless of age, gender or prior sun exposure, anatomical sites above the waist produced higher readings than below. BC and RBV were found to be dependent on age and gender at most sites with higher readings being observed in males and younger volunteers. The largest difference was seen in males under 55 years whose RFS readings above the waist were significantly higher than in older males or females of any age. Heavy prior sun exposure and skin thickness could not be demonstrated to impact on either RFS or LD readings independently of the effects of anatomical site, gender or age. In general, RFS and LD readings paralleled one another and correlated linearly at most anatomical sites. While RFS readings tended to decrease in the cranio-caudal direction, LD readings were relatively uniform across the body except for the head and groin where they were higher, and the abdomen where they were lower. The site-to-site variations in RFS readings observed in this study correspond well to capillary density variations noted in previous studies.