Identification of an Mr 75000 component of the H+/D-glucose cotransporter from Zea mays with monoclonal antibodies directed against the mammalian Na+/D-glucose cotransporter.

Monoclonal antibodies which interact with the mammalian Na+/D-glucose cotransporter and bind to Mr 75,000 and Mr 47,000 polypeptide components of this transporter have been described (Koepsell, H., Korn, K., Raszeja-Specht, A., Bernotat-Danielowski, S. and Ollig, D. (1988) J. Biol. Chem., 263, 18419-18429). The interaction of these antibodies with plasma membranes from Zea mays L. coleoptiles containing an H+/D-glucose cotransporter was studied. Four monoclonal antibodies cross-reacted with Mr 75,000 and Mr 33,000 polypeptides. One of these antibodies, which inhibits Na+/D-glucose cotransport in the kidney and stimulates Na+/D-glucose cotransport in intestine, stimulates electrogenic uptake of 3-O-methyl-D-[14C]glucose in plant membrane vesicles. The data indicate common epitopes in the mammalian Na+/D-glucose cotransporter and the H+/D-glucose cotransporter of plants and suggest that both transporters contain an Mr 75000 polypeptide component.

Aortic valve replacement and perioperative management in hemodialyzed patient wth antiphospholipid syndrome.

Antiphospholipid syndrome is characterized by the presence of antiphospholipid antibodies, hypercoagulability, and prolonged phospholipid-dependent coagulation indices such as activated clotting time (ACT). Perioperative thrombotic complications are frequent among patients with antiphospholipid syndrome submitted to cardiac surgery, therefore, in these patients, heparin-protamine titration for anticoagulation monitoring is particularly recommended. We demonstrate a case of 42-year-old hemodialyzed patient with antiphospholipid syndrome, submitted to the replacement of stenotic aortic valve. In our patient celite ACT and heparin concentration during cardiopulmonary bypass did not correspond to each other. Anticoagulation based on heparin concentration assessment resulted in safe perioperative hemostatic management.

[Hypercoagulation in patients with nephrotic syndrome]. / Stan nadkrzepliwosci u chorych z zespolem nerczycowym.

Hypercoagulation and thrombotic complications associated with nephrotic syndrome (NS) are known from many years. However pathomechanism of those disturbances is not very clear. The aim of the presented study was to determine the role of platelets in hypercoagulation phenomenon in NS patients. Studies were carried out in 15 patients with NS in the course of chronic glomerulonephritis and 15 healthy volunteers. Following parameters were estimated: prothrombin, time APTT, fibrinogen, FDP, plasminogen, antithrombin III, alpha 2-antiplasmin and using Technicon H1 autoanalyser: platelet count (PLT), mean platelet volume (MPV) and PLT Mode. Additionally platelets aggregation (spontaneous and after collagen, epinephrine, ADP) was measured using Apact (Labor) aggregometer. We observed in patients with NS: a) decrease of AT III, b) slight increase (not significant) of fibrinogen, c) decrease of MPV and Mode PLT, d) increased spontaneous aggregation and sensitivity to aggregating agents. Our results suggest that: 1. Pathomechanism of hypercoagulation in NS is multifactorial. 2. Changes in morphology and function of platelets could be one of the factor playing important role in this mechanism.

[Evaluation of factors influencing platelet aggregation in patients with chronic glomerulonephritis (CGN)]. / Ocena czynników wplywajacych na agregacje plytek krwi u chorych z przewleklym klebuszkowym zapaleniem nerek (PKZN).

Platelets (PLT) play an important role in hemostasis, modulation of immunological and inflammatory processes. There is also evidence that PLT takes part in the development of atherosclerosis and glomerulosclerosis. The aim of presented study was to determine morphological and functional changes of platelets and their relation to the lipid, protein and coagulation factors disturbances in patients with chronic glomerulonephritis (CGN). The studies were carried out in 60 patients with CGN diagnosed by renal biopsy: 30 patients without nephrotic syndrome (NS)-CGN and 30 patients with NS-CGN+NS. Protein and lipid disturbances, coagulation factors were estimated using routine laboratory methods. Platelet count (PLT), mean platelet volume (MPV) and modal platelet volume (PLT-Mode) were measured using Technicon H1 hematological autoanalyser. Platelet function was assessed by aggregometry using turbidimetric method (inductors: ADP 1-3 microM, collagen 50g/ml, epinephrine 0.25-5 microM). Spontaneous platelet aggregation (SPA) was measured in platelet rich plasma (PRP) without inductors for 15 min, in 1-2 hours after venesection. SPA was observed in 9 of 30 patients with CGN and in 19 of 30 patients with CGN+NS. MPV and PLT Mode were significantly higher in patient showing SPA compared with those without. Significant correlations between SPA and the concentration of plasma albumin (r = -0,70; p < 0.02) TG and CH-LDL (r = 0,61; p < 0.05) were found in CGN+NS patients. APTT was significantly shorter in patients showing SPA compared with those without and negative significant correlation between SPA and APTT was found. Platelet aggregation to inductors in CGN and CGN+NS patients was diminished compared with control group. Lack of second phase aggregation in response to aggregation inducers was observed in patients with SPA. Conclusions. 1. Platelet hyperaggregation play an important role in hypercoagulation state in CGN patients. 2. SPA in vitro was observed in majority of CGN+NS patients and in some without NS. 3. Pathomechanism of SPA is probably multifactorial (hypoalbuminemia, dyslipidemia, changes in concentration of coagulation parameters).

[Evaluation of platelet membrane structure in patients with chronic glomerulonephritis (CGN)]. / Ocena struktury blony plazmatycznej plytek krwi chorych z przewleklym klebuszkowym zapaleniem nerek (PKZN).

The structure of platelet membrane determines platelet surface glycoprotein receptors and correct cell function. Meanwhile different diseases and drugs may induce changes in this structure. The aim of this study was to determine structure of platelet lipid bilayer in patients with chronic glomerulonephritis (CGN) in comparison to control group. Studies were carried out in 30 patients with nephrotic syndrome (NS) and 30 patients without this syndrome and 15 controls. Electron spin resonance phenomenon with spin labelling, was used for estimation of platelet membrane structure. CGN patient platelets showed lower order parameter A/C and increased rotation correlation time tau in comparison with healthy subjects. It indicated abnormal platelet membrane structure in these patients. The negative significant correlation between parameter A/C and plasma fibrinogen concentration of NS patients has been found (r = -0.5; p < 0.05). Additionally the value of an order parameter (A/C) has significantly positively correlated with serum triglycerides concentration in patients with NS and spontaneous platelet aggregation (r = 0.52, p < 0.05). Conclusion. 1. CGN patient platelets have revealed disorders of lipid bilayer structure. 2. These disorders could be responsible for decreased platelet aggregation observed in CGN patients in comparison to healthy controls.

[Platelet defects in chronic myeloproliferative disorders]. / Zaburzenia plytkowe w przewleklych zespolach mieloproliferacyjnych.

Platelet abnormalities are common in patients with chronic myeloproliferative disorders. In this study we report abnormalities in platelets morphology and function in 45 patients with chronic myeloproliferative disorders: 15 with chronic myelogenous leukaemia (CML), 8 with polycythemia rubra vera (PRV), 20 with essential thrombocythemia, and 2 with myelofibrosis (ME). We investigated flow cytometric features of platelets as measured with Technicon H1 technology, VIZ, mean platelet volume (MPV), plateletocrit), platelet distribution width (PDW), and modal platelet volume (PLT Mode) Platelet aggregation in response to ADP, epinephrine and collagen was used as functional test. In patients with ET, PRV and MF we found a significant decrease in platelet volume (both MPV and PLT MODE). Decrease in platelet aggregation and secretion in response to ADP, epinephrine and collagen was the most frequent abnormality in platelets function and was observed in most of patients with thrombocythemia in chronic myeloproliferative disorders.

[Reference values for peripheral blood morphology in countryside population of northern Poland]. / Wartosci referencyjne dla parametrów morfologii krwi obwodowej w populacji wiejskiej Polski pólnocnej.

Reference values for hematological parameters were determined in countryside population living in the area surrounding Zarnowieckie Lake. Randomly selected population of 1065 individuals were divided into 11 groups: children from 0 to 3 years, 4 to 7 years and 8 to 11 years; and males and females from 12 to 20 years, 21, to 40 years, 41 to 55 years and older than 56 years. In the paper are presented reference values estimated on Technicon H1 analyser for 8 red cells parameters, 3 platelets parameters and absolute values for white blood cell and differential counts. Red cell parameters values were changing with age and sexes, and were similar to determined by the others. In examined population white blood cell counts were higher then in earlier reports. Moreover in males over 40 WBC were higher than in females. Neutrophil counts were parallel to white blood cells. Lymphocyte and eosinophil counts were decreasing with age, and were not depending on sex. Platelet counts were decreasing with age, with concommitant MPV increase.

Relationships between thrombohemorrhagic complications and platelet function in patients with essential thrombocythaemia.

Three subgroups have been distinguished in essential thrombocythaemia (ET) patients, on the basis of clinical and laboratory findings. ET patients with bleeding incidents had smaller platelet volume, lower concentrations of beta-thromboglobulin and platelet factor 4 in their plasma, 10%, 26%, and 26% lower compared to patients without complications, respectively. ATP secretion from platelets of bleeders, clotters, and "no-complications" ET patients was found to be 75%, 36%, and 45%, respectively, lower than in healthy people. Spontaneous platelet aggregation appeared to be normal in about 90% of ET patients with no complications and in all bleeders but only in 35% patients with clotting incidents. All bleeders had abnormal agonist-evoked aggregation assays. Among remaining ET patients 30%-60% displayed normal values of different evoked aggregation tests. Thus, clinically distinguished group of bleeding ET patients may be differentiated from other subgroups on the basis of laboratory findings.

Monoclonal antibodies against the renal Na+-D-glucose cotransporter. Identification of antigenic polypeptides and demonstration of functional coupling of different Na+-cotransport systems.

Eight monoclonal antibodies are described which are directed against the renal Na+-D-glucose cotransporter. In porcine renal brush-border membranes, the antibodies either bind to one or to three polypeptides which have been identified as components of the Na+-D-glucose cotransporter (Neeb, M., Kunz, U., and Koepsell, H., (1987) J. Biol. Chem. 262, 10718-10727). Their molecular weights and isoelectric points are 75,000 and pH 5.5, 60,000 and pH 5.2, and 47,000 and pH 5.4. Six antibodies were able to influence Na+-dependent D-glucose uptake and/or Na+-dependent high affinity phlorizin binding. In the presence of Na+, the binding of all antibodies to native membrane proteins was altered by D-glucose but not by D-mannose. Since this effect was observed with D-glucose concentrations less than 1 x 10(-8) M, a high affinity D-glucose-binding site on the D-glucose transporter has been implied. Some of the antibodies probably interact also with other Na+-coupled transporters since their binding was altered by micromolar concentrations of L-lactate, L-alanine, or L-glutamate but not by the nontransported control substances D-alanine and D-glutamate. L-lactate increased the binding of one antibody in the absence but not in the presence of D-glucose. Effects of L-lactate and L-alanine on the binding of another antibody were only observed when D-glucose was present. Thus, some epitopes on the Na+-D-glucose cotransporter are altered by D-glucose and also by substrates of other Na+ cotransporters. This finding suggests functional coupling of different Na+-cotransport systems.

Influence of spontaneous platelet aggregation on progression of glomerular disease.

UNLABELLED: Platelet secretion products may play an important role in the pathogenesis and progression of the kidney disease. Amongst the parameters describing platelet hyperactivity the measurement of spontaneous platelet aggregation (SPA) seems particularly useful. In this study SPA as well as mean platelet volume (MPV), modal platelet volume (PLT Mode) and platelet count (PLT) were investigated in 60 patients with biopsy proven primary glomerulonephritis. SPA was measured using the turbidimetric method according to Born with no enhancers added. Serum creatinine concentration (Cr), reciprocal serum creatinine concentration (1/Cr) and endogenous creatinine clearance (Cl(Cr)) were used for the renal function estimation. Protein and lipid profiles as well as coagulo-fibrinolytic balance were measured in parallel. The investigated group consisted of 30 non-nephrotic patients (CGN) - in 9, SPA was found (CGN-B) while 21 had SPA <10% (CGN-A), and 30 nephrotic patients (CGN+NS) - 19 with SPA (CGN+NS-B) and 11 without (CGN+NS-A). SPA was found to be a constant platelet feature in patients with chronic glomerulopathy. The group remained under observation for 36 months. 41 patients were included in the 3-year prospective study which revealed the significant influence of the blood platelet hyperaggregability on the renal disease progression. A significantly increased serum creatinine concentration, decreased 1/Cr parameter and decreased glomerular filtration rate (Cl(Cr)) were noted in subgroups showing SPA. A significant correlation between SPA and (Delta)Cr/month (r = 0.41), (Delta)1/Cr/month (r = 0.38) as well as (Delta)Cl(Cr)/month (r = 0.52) was found. The platelet activity and thus SPA can be altered by various factors: albumin and fibrinogen plasma concentrations, thrombosis activation and possibly lipoprotein metabolism disturbances. A characteristic feature of spontaneously aggregating platelet is their increased volume (MPV). CONCLUSION: Platelet hyperaggregation in one of nonimmunological factors stimulates the progression of glomerulonephritis.

Effect of saturated air and nitrox diving on selected parameters of haemostasis.

The objective of the study was to evaluate decompression stress after air and nitrox saturated divings on the basis of the parameters of haemostasis. Before and after each diving the following examinations were performed: blood platelet count, aggregation, fibrinogen level and coagulation factors VII, X and XII. After the air saturated dives a slight reduction of factor X and XII and of fibrinogen was observed. Evaluation of haemostatis may be one of the basic elements in the assessment of decompression sickness risk.