The effect of dextran infusion on antithrombin III concentrations and on platelet function during minor surgery.

The effects of dextran on the antithrombin (AT) III activity and blood coagulation, evaluated with thromboelastography, were investigated in 26 patients (anaesthesia risk class I or II) scheduled for minor surgery under general anaesthesia. In the Dextran group the patients were infused first with dextran 7 ml/kg, then with Ringer's acetate. In the Ringer group, the patients received only Ringer's acetate. In the recovery room fluid therapy was continued with 5% dextrose in water until the first postoperative day. Blood loss and fluid replacement were comparable in the groups. Haematocrit (Hcr) decreased significantly in the Dextran group, and the platelet count decreased in both groups during surgery. The median baseline AT III values were similar in the study groups. In the recovery room, the median AT III value was lower in the Dextran than in the Ringer group, 78% and 92%, respectively (P < 0.05). By the following day, the AT III values had returned near the initial level. After surgery, the maximal amplitude of thromboelastogram was 48 mm in the Dextran group, and 58 mm in the Ringer group (P < 0.05). In conclusion, fluid replacement with dextran resulted in modest and short-lived alterations in blood coagulation.

Replacement of major surgical blood loss by hypo-oncotic or conventional plasma substitutes.

The purpose of the study was to examine the effects of hypooncotic 4% hydroxyethyl starch 120/0.7, 3% dextran 70, 5% albumin and hyperoncotic 6% hydroxyethyl starch 120/0.7 on the perioperative colloid osmotic pressure (COP), albumin and protein concentrations and fluid balance. The plasma substitutes were used with red cell concentrates to replace blood loss with equal volume in sixty major abdominal or urological surgeries. A special effort was made to keep replacements and losses at even volumes constantly and to avoid fluctuation of blood volume. The blood specimen were obtained before induction, after each 20% blood loss, at the end of the recovery room phase and on the three following postoperative mornings. There were significant differences in the peroperative and immediate postoperative COPs. However, these differences had vanished by the first postoperative morning. COP was preserved above 16 mmHg in all groups throughout the study. The identical peroperative albumin and protein concentrations of the synthetic colloid groups suggests that their volume effect was the same, regardless of the varying COP. During the observation period there were no significant differences among the groups concerning the diuresis and the fluid balances. We conclude, that the hypooncotic 4% HES 120 and 3% dextran 70 solutions provide the same clinical effect as 6% HES 120 solution. Consequently less colloid is needed, which allows the use of greater volumes of the dilute colloid solutions in replacement therapy.

Plasma concentrations of bupivacaine and two of its metabolites during continuous interscalene brachial plexus block.

An interscalene brachial plexus block was performed via a catheter with 20-28 ml of 0.75% bupivacaine plus adrenaline for surgery of the shoulder region in 12 patients. Constant infusion of 0.25% bupivacaine 0.25 mg kg-1 h-1 was continued for 24 h. During surgery light general anaesthesia, without analgesics, was maintained. Plasma concentrations of total and unbound (free fraction) bupivacaine, desbutylbupivacaine (DBB), 4-hydroxybupivacaine (4-OHB) and alpha 1-acid glycoprotein (AAG) were measured at predetermined intervals during the continuous block. The greatest mean plasma concentrations of bupivacaine were measured at 30 min (1.63 (SD 0.55) micrograms ml-1) and 60 min (1.38 (0.48) micrograms ml-1). There was a small but statistically significant increase in the plasma concentration of bupivacaine between 12 and 24 h of infusion. The mean unbound concentration of bupivacaine in plasma decreased from 0.044 (0.015) microgram ml-1 (3.6 (1.1)% of total bupivacaine concentration) at 3 h to 0.023 (0.011) micrograms ml-1 (2.1 (1.0)%) at 24 h. The AAG concentration in plasma increased by 38% in 24 h. The metabolites DBB and 4-OHB were detectable in plasma from 30 min, with a gradual increase during infusion. At 24 h the mean concentrations of DBB and 4-OHB were 0.33 (0.22) micrograms ml-1 and 0.13 (0.04) micrograms ml-1, respectively. There were no toxic reactions during the blocks.

Continuous interscalene brachial plexus block: clinical efficacy, technical problems and bupivacaine plasma concentrations.

Continuous interscalene brachial plexus block with a single dose of 0.5% bupivacaine 1.25 mg/kg, continued with an infusion of 0.25% bupivacaine 0.25 mg/kg/h, was performed on 24 patients to provide analgesia during shoulder surgery and in the postoperative period. The drugs for general anaesthesia included glycopyrrolate, thiopentone, vecuronium, enflurane and N2O/O2. All patients had signs of regional analgesia 30 min after the block without haemodynamic problems. The infusion of local anaesthetic was interrupted in six patients because of a failure in catheter function. Of the remaining 18 patients, nine needed no complementary analgesics and nine patients received, on average, 1.6 doses of oxycodone (0.15 mg/kg/dose) during a 24-h period. Displacement of the interscalene catheters could be prevented by a fixation suture to the skin. Two patients noted a metallic taste during the bupivacaine infusion. The most common complaints were numbness of the hand (n = 15) and hoarseness (n = 5). The mean (+/- s.e.mean) plasma concentrations of bupivacaine at 30, 60, 180 min and 24 h were 0.68 +/- 0.06, 0.62 +/- 0.05, 0.52 +/- 0.04 and 0.76 +/- 0.01 micrograms/ml, respectively. During the 24-h period, the alpha 1-acid glycoprotein (AAG) concentration (mean +/- s.e.mean) in plasma rose from 0.41 +/- 0.04 g/l to 0.54 +/- 0.04 g/l (P less than 0.001). The concentration of free bupivacaine was below detectable levels (less than 0.01 micrograms/ml) after the 24-h infusion. The rise in AAG probably increases binding of bupivacaine to plasma proteins, diminishing the risk of systemic toxicity.

Influence of premedication on lignocaine-induced acute toxicity and plasma concentrations of lignocaine.

The effects were studied, in eight healthy volunteers, of premedication with diazepam 0.14 mg kg-1 by mouth or hyoscine 6 micrograms kg-1 + morphine 0.2 mg kg-1 i.m., or no premedication, on toxic symptoms and plasma concentrations after rapid i.v. injection of lignocaine 1 mg kg-1. The alpha 1-acid glycoprotein (AAG) and albumin plasma protein fractions were assessed. A variety of mild central nervous system (CNS) symptoms were experienced after the bolus of lignocaine. However, there was no correlation between premedication and degree of severity or number of CNS symptoms. The highest single arterial plasma concentration of lignocaine was 11.0 micrograms ml-1, 1 min after injection. There was no correlation between plasma concentration of lignocaine and occurrence of CNS symptoms. Furthermore, there was no correlation between AAG or albumin plasma concentrations and lignocaine plasma concentrations.

A multi-centre evaluation of the FP-900 analyzing system.

The performance of the FP-900 Analyzing system manufactured by Labsystems Oy, Helsinki, Finland, was evaluated in a multi-centre study according to the principle outlined in the 1st Draft of the Standard for Instrument Testing produced by the European Committee for Clinical Laboratory Standards (ECCLS). The FP-900 System comprises a photometer for simultaneous measurement of the absorbance in a nine-compartment cuvette block, and the accessories for handling samples (sampler, simultaneous dispensing of 9 reagent charges, incubator with thermostat and shaker, and centrifuge); the photometer function, printout of results and data processing are programmable with a microprocessor. The performance specifications given by the manufacturer were checked when appropriate. As examples of typical methodologies cholesterol was selected as an end-point absorbance method, creatinine as a fixed-time (two-point) kinetic and aspartate aminotransferase as multi-point, continuous method. The within- and between-laboratory imprecision, deviation from assigned values of commercial control sera, and carry-over were determined. The performance was compared with other analytical systems: Mark I Autoanalyzer and Hitachi 705. The cost, speed and capacity was estimated from the results of the present study. The performance of the analyser and results of applying the ECCLS Draft to actual instrument testing are discussed.

Effect of cyclosporine on wound healing.

Two prophylactic immunosuppressive drugs, cyclosporine and methylprednisolone (MP), were compared for their effect on the in situ inflammatory reaction of granulation tissue formation and on wound healing. Granulation tissue was generated via implantation of viscous cellulose sponges in Sprague-Dawley rats. The rats were divided into six groups: One group received 40 mg/kg/day of cyclosporine, the second 10 mg/kg/day of cyclosporine, the third 2.5 mg/kg/day of cyclosporine, the fourth 12 mg/kg/day of MP, the fifth received the cyclosporine solvent, and the sixth group was given only saline. All drugs were given i.p. No reduction in the number of inflammatory cells was observed in the cyclosporine-treated sponges compared with the controls, whereas MP suppressed the inflammation strongly. Differential counts demonstrated a relative enrichment of macrophages in the cyclosporine-treated versus the MP-treated or control sponges. Chemical analyses of the sponge extracts agreed well with the cytological data: MP suppressed the total DNA content of the sponges, a marker of total cellularity, as well as the content of acid phosphatase and beta-glucuronidase, both markers of macrophages, but no such suppression was seen in the cyclosporine-treated sponges. The alkaline phosphatase content, a marker for granulocytes, was similar in all groups. A remarkable suppression in the contents of hydroxyproline, reflecting the amount of collagen, and in that of hemoglobin, reflecting the amount of neovascularization, was observed in the MP-treated sponges, whereas no such suppression--but possibly a slight enhancement of the second parameter--was observed in the cyclosporine-treated sponges. We conclude that, in contrast to MP, cyclosporine does not inhibit the inflammatory reaction of granulation tissue formation or the regenerative process of wound healing.

Haemoglobin Hijiyama: a haemoglobin variant found in connection with glycosylated haemoglobin estimation in a Finnish diabetic boy.

A variant of haemoglobin A, named earlier haemoglobin Hijiyama, was found in three generations of a Finnish family in connection with the determination of glycosylated haemoglobin of a diabetic patient. The biochemical abnormality is in the beta-chain at residue 120 where lysine is replaced by glutamic acid. In the heterozygote carriers of the abnormal haemoglobin there was no apparent association with clinical or haematological abnormalities. By isoelectric focusing in thin-layer polyacrylamide gels, haemoglobin Hijiyama could be distinguished with high specificity from haemoglobin A as well as from other haemoglobin variants earlier found in Finland. The glycosylated haemoglobin fractions (haemoglobin A1 and haemoglobin Hijiyama 1) in the diabetic patient sample could be determined by colorimetric and electrophoretic methods.

Organization of membrane lipids and proteins in human En(a-) erythrocytes that lack the major sialoglycoprotein, glycophorin A. A spin-label study.

Membrane fluidity was studied by electron-spin-resonance techniques in human En(a-) erythrocytes that lack the major membrane sialoglycoprotein, glycophorin A. By using stearic acid spin labels with a doxyl group in the C-12 or C-15 positions, we demonstrated that the hydrophobic core in these cells was more fluid than in normal cells. Surface-located regions in isolated En(a-) membranes, when probed with stearic acid labelled in the C-5 position, appeared more stable than in normal membranes. In isolated En(a-) membranes, protein motion was decreased when probed with a nitroxide derivative of maleimide. After incubation with anti-(glycophorin A) antibodies protein motion and membrane fluidity were increased in normal membranes. This effect was observed also after spectrin depletion, which by itself increased protein motion but decreased membrane fluidity in the hydrophobic core of the membrane. The results show that membrane proteins influence the fluidity of membrane lipids.

Benign congenital erythropenia.

Normochromic anaemia was diagnosed in two brothers in early infancy. At the time of this report they were aged 10 (M.H.) and 12 (T.H.) years. A defect of the atrial septum was found in both patients. They had slight skeletal malformations. Their haemoglobin values have remained constantly at the level of about 100 g/l and the RBC count at about 3.5 x 10(12)/l. At repeated examinations, both the patients and their parents had low or borderline low erythrocyte enolase levels. Erythropoietin levels were normal and so were numerous other laboratory tests, including analysis for abnormal haemoglobins. The condition could represent a mild form of chronic congenital hypoplastic anaemia.

Factors affecting plasma beta-thromboglobulin in diabetes mellitus.

Plasma beta-thromboglobulin, hemoglobin A1c and serum creatinine were measured in 56 diabetic patients. Patients with diabetic complications had a significantly higher beta-thromboglobulin level than the controls, but patients without complications did not differ from the controls. beta-Thromboglobulin correlated positively with serum creatinine and the highest values were encountered in patients with abnormal creatinine concentration. There were, however, patients with normal creatinine but high plasma beta-thromboglobulin levels. In these patients the abnormal beta-thromboglobulin level most probably indicates undue stimulation of platelets. There was no correlation between beta-thromboglobulin and hemoglobin A1c.

Membrane characteristics and metabolic properties of glucose-6-phosphate dehydrogenase deficient red cells.

Two Finnish variants of reduced erythrocyte glucose-6-phosphate dehydrogenase (G-6-PD) activity were studied. The G-6-PD Espoo variant is characterized by severe enzyme deficiency which is normally non-haemolytic although primaquine sensitive. The other variant, G-6-PD Helsinki, in which the enzyme activity is moderately reduced, is associated with chronic haemolytic anaemia. The activity of the pentose phosphate pathway was not stimulated by methylene blue in G-6-PD Espoo cells, whereas in normal and G-6-PD Helsinki cells there were increases in shunt activity of 64.5- and 5.3-fold, respectively. As judged by the accumulation of 6-phosphogluconate after incubation with 6-aminonicotinamide, the activity of the pentose phosphate pathway was similar in normal and G-6-PD Helsinki cells, whereas in G-6-PD Espoo cells the metabolic flux through this pathway was decreased. Quantities of sulphydryl groups in intact cells and isolated membranes were similar in normal and G-6-PD deficient cells, as revealed by spin label experiments. In contrast to the situation in normal cells, sulphydryl groups in G-6-PD Espoo cells, and to a lesser extent in G-6-PD Helsinki cells, were sensitive to oxidation by acetylphenylhydrazine. In the G-6-PD Helsinki cells, but not in the G-6-PD Espoo cells, membrane fluidity was increased, as judged from the increased mobility of the stearic acid spin label. Mechanisms are discussed by which G-6-PD deficient cells retain adequate levels of NADPH during resting conditions, and it is suggested that the chronic haemolysis associated with G-6-PD Helsinki could be due to a defect in the lipid region of the cell membrane.

Influence of the Taurus radiowave blood warmer on human red cells. Hemolysis and erythrocyte ATP and 2,3 DPG concentrations following warming by radiowaves, microwaves and water bath.

The warming properties of the Taurus radiowave blood warmer were studied. The safety limits were the same as for microwave warming (Haemotherm). Hemolysis was noted in units with a hematocrit over 0.75 or containing less than 300 g of blood. The effects of radiowave, microwave and water bath warming on the erythrocyte ATP and 2,3 DPG concentrations were compared. Statistically highly significant differences were found between all these methods. Warming of blood in a +35 degrees C water bath for 3 min had no effect on these parameters. There was, however, a tendency for ATP and 2,3 DPG levels to decrease after 60 min water bath incubation (+37 and +45 degrees C), but to increase levels following electromagnetic warming depending on the age of the warmed erythrocytes. Thus, electromagnetic radiation appeared to influence the red cell metabolism, which cannot be explained by the effect of temperature alone.

Evidence of riboflavin depletion in breast-fed newborns and its further acceleration during treatment of hyperbilirubinemia by phototherapy.

Phototherapy in the treatment of newborns with hyperbilirubinemia, resulting in degradation of bilirubin, also appears to have other photodynamic effects on metabolism. We studied flavin adenine dinucleotide (FAD) saturation of erythrocyte glutathione reductase, which should reflect riboflavin nutritional status, in 28 healthy newborns, and followed 37 newborns with hyperbilirubinemia prior to the start of and during phototherapy. The results indicate that healthy newborns on human milk feeding, relatively poor in riboflavin, have evidence of a transient riboflavin depletion soon after birth. This effect is made more pronounced by phototherapy and partially prevented by parenteral or oral administration of moderate amounts of riboflavin.

Stability of IgG solutions, especially anti-D gammaglobulin, with special reference to measured proteolytic activity and degradation.

The stability of IgG solutions during the dating period can be predicted by measuring the degree of degradation after elevated storage conditions at +37 degrees C with added streptokinase. The measurement of proteolytic activity with a synthetic substrate correlates with the results obtained by SDS-disc gel electrophoresis and gel filtration. IgG molecules having Anti-D activity were observed to be essentially more sensitive to proteolytic degradation by plasmin than IgG molecules in general. It seems, therefore, that the methods which are suitable for the study of the stability of normal IgG preparations are not sufficient to predict the stability of anti-D gammaglobulin preparations.