G. Myllylä

Hemostatic factors and replacement of major blood loss with plasma-poor red cell concentrates.

The purpose of this study was to assess the change of platelet and fibrinogen concentrations and the change of activities of prothrombin and factors V and VII when major surgical blood loss was replaced with plasmapoor red cell concentrates (RCCs) and colloid plasma substitutes.Sixty patients were studied. The average blood loss was 65% +/- 41% of the calculated blood volume (CBV). Blood loss was monitored carefully and replaced without delay to ensure stable blood volume. Blood samples were obtained at the induction of anesthesia and at the end of the recovery room period, or before the patient was given fresh frozen plasma. In addition, a platelet count was determined after each 20% blood loss. The results were converted to relative values, and simple linear regression with logarithmic transformation was applied. The initial platelet concentration was 257 +/- 89 times 103/mm3 and the extrapolation of the regression line intercepted the critical level of 50 times 10 (3/mm)3 at 230% (confidence interval 169%-294%) blood loss. The initial fibrinogen concentration was 3.7 +/- 1.1 g/L and the hemostatically significant level of 1.0 g/L was already reached at 142% (117%-169%) blood loss (r2 = 0.90). Activities of prothrombin and coagulation factors V and VII reached their critical levels at 201% (160%-244%), 229% (167%-300%), and 236% (198%-277%) blood loss, respectively. We conclude that deficiency of fibrinogen develops earlier than any other hemostatic abnormality when plasma-poor RCCs are used for the replacement of major blood loss. (Anesth Analg 1995;81:360-5)

[4] Production of interferon in human leukocytes from normal donors with the use of Sendai virus

Publisher Summary This chapter describes the method used for the production of human leukocyte interferon. The production of interferon is highly sensitive to changes in the incubation conditions. Better yields are obtained in round flasks, for example, than in ordinary flat-bottom bottles. The aeration seems to play an important role. Attempts to improve production by bubbling air or CO 2 into the medium during the incubation have not been successful. The cells must be kept in constant agitation. If the stirrers are intentionally stopped at different times after induction, the production of interferon declines rapidly, although the settling of the cells to the bottom takes several hours. The removal of most globulins by (NH 4 ) 2 SO 4 -precipitation does not affect the activity of serum, and the reduction of antibodies to Sendai virus appears not only to lower the amount of the inducer virus needed but also to make the yields of interferon more consistent. Factors such as priming, induction, temperature, pH, and incubation medium, affect the yield of interferon, but not the kinetics of the production in human leukocyte suspensions. The pH range for optimum interferon production is between 7.2 and 7.6.

Alkali-stable blood group A- and B-active poly(glycosyl)-peptides from human erythrocyte membrane.

The study of the chemical nature of the ABH blood group antigens of the human erythrocyte membrane has been advanced in recent years by the isolation and characterization of several glycosphingolipids with blood group activity [l-3] . It has been reported that blood group ABH activity is present also in glycoproteins of the erythrocyte membrane [4-91. However, since these observations have been mainly based on serological inhibition tests, the presence of blood group-active glycolipids in the glycoprotein preparations cannot be excluded. Owing to the water solubility of the large-molecular size blood groupactive glycosphingolipids (the poly(glycosyl)ceramides), it has been suggested that these glycosphingolipids may have been regarded in some studies as glycoproteins [3]. The occurrence of protein-bound blood group ABH antigens in the erythrocyte membrane has therefore still been a matter of some controversy. In the present paper, we present direct chemical evidence for the occurrence of protein-bound blood group ABH antigens in the erythrocyte membrane. This was accomplished by the preparation of glycopeptides with pronase digestion from lipid-free membrane residues and the isolation of the blood group Aand B-active fractions using the a-galactosyland a-Nacetylgalactosaminyl-binding lectin [ 10,l l] of Bandeiraea simplicifolia (BS I lectin). The glycopeptides are composed of about 50-60 sugar residues/

Changes in the life expectancy of patients with severe haemophilia A in Finland in 1930‐79

Summary. Important advances have been made in the treatment of haemophilia during the past 30 years. We have analysed the data of all the known 163 patients with severe haemophilia A living in Finland in 1930–79 in order to study changes in the prognosis of severe haemophilia A. During the period of 50 years the mean age at death of the patients has increased from 7.8 years in 1930‐39 to 25.5 years in 1970–79 and the annual death rate has markedly decreased in all age groups. The decline has been greatest in patients under 10 years of age. In this age group the annual death rate decreased from over 50 per thousand in 1930‐39 and 1940‐49 to 4.8 per thousand in 1970–79. The prognosis of patients with inhibitors has remained poor, however. Five of the six deaths during the last decade occurred in patients with inhibitors. The overall annual death rate of patients without inhibitors was only 1.2 per thousand in 1970–79, suggesting that at the present time the life expectancy of patients who do not develop inhibitors does not markedly differ from that of the general male population.

Persistent Mixed Field Polyagglutinability

Abstract. The red cells of a 28‐year‐old healthy group O donor, Mr. O.S. (OS‐cells), have persisted, over 4 years of investigation, in showing mixed field polyagglutinability. About 50% of the red cells are agglutinated by the great majority of human sera from adults, by some seed and snail extracts and by the serum of various animals. The cells further show a certain affinity for anti‐A reagents which can be distinguished from that of true A cells. The sialic acid content of the polyagglutinable fraction of the cells is decreased with consequent reduction in their electrophoretic mobility. Inhibition tests show that the disturbance involves n‐acetyl‐d‐galactosamine.

Association of Hormone Replacement Therapy With Hemostatic and Other Cardiovascular Risk Factors The FINRISK Hemostasis Study

The risk of cardiovascular diseases in women is small until menopause but increases considerably afterwards. When all age groups are considered, cardiovascular diseases are responsible for approximately half of the total mortality in women. It has been suggested that hormone replacement therapy (HRT) in perimenopausal and postmenopausal women could be useful in the prevention of cardiovascular diseases, but its effects are insufficiently known. We performed a cross-sectional study on the associations of menopause and HRT with cardiovascular risk factors, in particular with hemostatic factors, on female participants of the FINRISK Hemostasis Study. The participants, aged 45 to 64 years, were recruited from the Finnish population register by random sampling from three geographically defined areas. The participation rate of women was 83.2%. Of the 1202 women included in the study, 29.2% were current users of HRT. Differences in cardiovascular risk factors by menopausal status and by HRT use were examined after adjustment for age, study area, current smoking, body mass index, self-reported diabetes, and years of education. Postmenopausal women not using exogenous sex hormones had on average a total cholesterol level 0.5 mmol/L (8.9%) higher and an LDL cholesterol level 0.4 mmol/L (11.4%) higher than premenopausal women. Women reporting irregular menstruation (presumably due to perimenopause) had higher adjusted plasma fibrinogen, factor VII coagulant activity, and factor VII antigen than women with regular menstruation or no menstrual periods.(ABSTRACT TRUNCATED AT 250 WORDS)

Cytoskeleton-dependent release of human platelet epidermal growth factor

To study the source of immunoreactive epidermal growth factor (ir-EGF) released by thrombin formation we removed 99.9% of the leukocytes normally present in platelet-rich plasma and induced coagulation with 30 mM of Ca2+. The absence of leukocytes did not reduce the amount of ir-EGF released; thus platelets are most likely the only source of the ir-EGF released during aggregation. To identify the site of ir-EGF in platelets we exposed washed platelets to collagen or thrombin and compared the kinetics of releases of ir-EGF, beta-thromboglobulin (bTG, an alfa-granule marker), ATP (dense granule marker), N-acetyl-beta-D-glucosaminidase (NAGA, a lysosome marker) and lactate dehydrogenase (LDH, a cytoplasmic marker). Release of ir-EGF started immediately and continued linearly. The process differed clearly from the releases of the granule markers, which occurred readily, and were completed in a few minutes. The release of ir-EGF also differed from the leakage of LDH, the start of which was delayed greater than 5 min, but then proceeded linearly. Cytochalasin B inhibited the release of hEGF, but demecolcine had no effect. We conclude that the ir-EGF released from platelets during aggregation derives neither from the granules nor the cytoplasma. The assembly of cytoskeleton is needed for its release.

Amount and type of leukocytes in 'leukocyte-free' red cell and platelet concentrates.

Abstract. The exact number of leukocytes remaining in ‘leukocyte‐free’ red cell and platelet concentrates cannot be measured by standard methods. We have therefore developed methods to harvest all the leukocytes from blood components. The leukocytes were then counted and identified using monoclonal antibodies. The leukocyte‐free red cell concentrates were prepared by combining buffy coat removal and filtration through a Cellselect filter. The mean number of leukocytes per unit was 1.0 times 105. Most of the leukocytes were granulocytes and T cells. Only a few B cells or monocytes could be detected. Leukocyte‐free platelets were prepared by filtering 4 units of PC through a cotton‐wool (Imugard) filter. The mean number of leukocytes per PC unit was 0.4 times 105 of which 85–95% were T cells.

Transfusion Thresholds in Common Elective Surgical Procedures in Finland

Background and Objectives: Transfusion practices and thresholds in common elective surgical procedures were investigated in a nationwide multicenter survey in Finland. Materials and Methods: The records of 764 total hip replacement (THR), 397 total knee replacement (TKR) and 343 transurethral resection of the prostate (TURP) patients were reviewed by four anesthesiologists. Results: The allogeneic red cell (RBC) transfusion rates in THR, TKR and TURP operations were 92, 84 and 18%, respectively. In THR and TKR, 74% of patients who lost 20% or less of their blood volume during hospitalization were transfused with RBCs. Postoperatively, the median pretransfusion hemoglobin values were 9.6 g/dl in orthopedic operations and 10.7 g/dl in TURP. In some hospitals, the median transfusion threshold in TURP patients was as high as 11.2 g/dl. Conclusion: The transfusion thresholds in all operations were liberal compared to recent international recommendations. Inappropriate thresholds were reflected in the high transfusion rates. This study accentuates the need for continuous discussion and educational measures to find optimal indications for transfusion in surgery, and to rationalize the transfusion policy in Finland.

Systematic Use of Leukocyte‐Free Blood Components to Prevent Alloimmunization and Platelet Refractoriness in Multitransfused Children with Cancer

A major drawback in the use of platelet transfusions is the development of platelet refractoriness that is usually caused by alloimmunization provoked by leukocytes present in the blood products. We evaluated the development of alloimmunization both by serological demonstration of HLA antibodies and by clinical demonstration of platelet refractoriness in 50 multitransfused children who exclusively received filtered, leukocyte‐free blood products. The basic diagnoses included acute leukemia, pediatric solid tumors, and severe aplastic anemia. We also present a reference group of 10 similarly multitransfused children, who either deliberately or inadvertently had received nonfiltered blood products on some occasions. In the study group of 50 children, none developed platelet refractoriness. The median corrected increment was 11.1 times 109/1 at the time of initial diagnosis, and 10.4 at the time of the study 8 months later (median). None had detectable HLA antibodies in serum. In contrast, in the reference group 3/10 had HLA antibodies in serum, and 1/10 was clearly refractory to random pooled platelets. We conclude that systematic use of leukocyte‐free blood components effectively prevents alloimmunization in heavily transfused children with cancer. Leukocyte depletion to the level of < 1 times 106 of contaminating leukocytes per unit is sufficient and seems to prevent alloimmunization totally.