Search PubMed⌕ Search

Biomedical subjects

T A Lane

Publications and source records attributed to T A Lane.

72 records · Page 4Linked to original sources
PubMed1978

Factor V antibody and disseminated intravascular coagulation.

A factor V inhibitor arose in a 79-year-old man within 1 month of an operation for a fractured leg. Absorption studies with solid-phase antibodies to human immunoglobulins showed the inhibitory activity to be primarily in the IgG class, but also in the IgA class, of immunoglobulins. This is the first report of an IgA immunoglobulin with factor V inhibitory activity. While the inhibitor was present, and at a time when no circulating Factor V activity was detectable, the patient developed septicemia and disseminated intravascular coagulation. The mechanism sustaining disseminated intravascular coagulation despite the absence of circulation factor V activity remains unexplained. The factor V inhibitor disappeared within 5 months of its initial detection. Possible origins of factor V inhibitors are discussed.

Aged↗
PubMed1976

Lipid synthesis in human erythroid cells: the effect of sickling.

Human reticulocytes are capable of synthesizing membrane lipids from 14C-glycerol de novo. In both sickle and nonsickle reticulocytes the majority of 14C-glycerol was incorporated into phospholipids, primarily phosphatidylserine and phosphatidylcholine. Incorporation into sphingomyelin was minimal. The most abundant neutral lipid synthesized was triglyceride. In the absence of sickling, the rate of lipid synthesis in sickle reticulocytes was similar to that of nonsickle reticulocytes. With the induction of sickling under anoxic conditions sickle reticulocytes showed a prompt increase in the rate of lipid synthesis to an average of 69% above control values, while nonsickle reticulocytes under similar conditions decreased the rate of lipid synthesis. An increase in the rate of membrane lipid synthesis is associated in the mammalian erythroid cell with cell membrane damage. The findings further confirm that lesions of the erythroid cell membrane in sickle cell anemia are secondary to the sickling process itself.

Anemia, Hemolytic, Autoimmune↗
PubMed1976

Decreased life span and membrane damage of carbamylated erythrocytes in vitro.

Red blood cells exposed to cyanate (CNO) in vitro have a concentration-dependent decreased cell survival time associated with an inhibition of the ability of the cell membrane to synthesize lipids. The t1/2 of rabbit erythrocytes exposed to 30 mM or 50 mM cyanate for 1 hr at 37 degrees C is reduced from the normal 24 days to 15 and 9 days, respectively. The cyanate-induced defect in membrane lipid metabolism is irreversible. Carbamylation of membrane proteins and damage to metabolism are minimized by limiting exposure in vitro to 15 mM cyanate at 4 degrees C for 30 min. Cells carbamylated under these conditions do not have a shortened life span. Levels of globin carbamylation of 0.5 moles CNO/mole hemoglobin, shown to be clinically effective in prolonging the life span of sickle erythrocytes, are obtained under these conditions and reach maximal levels after only 30 min of incubation. Carbamylation of blood in CPD anticoagulant is inferior to either ACD or heparin. The findings indicate that adequate carbamylation of sickle erythrocytes with minimal red cell membrane damage can be achieved without significant modification of the standard plasmapheresis procedure utilized by the working blood bank.

Anemia, Sickle Cell↗
PubMedDate not supplied

Continuous-flow leukapheresis for rapid cytoreduction in leukemia.

Three patients with leukemia were treated for acute leukostasis using the continuous-flow cell separator. The first patient, treated with a standard procedure sustained only a 14 per cent decrease in leukocyte count even though 50 X 10(10) leukocytes were removed. A more aggressive approach was taken with the second two patients by increasing the rate of leukocyte removal three- to fourfold. In these patients, 100 to 230 X 10(10) leukocytes were removed and prepheresis counts dropped by 48 to 85 per cent. Both had satisfactory clinical response to pheresis. The data suggest that an aggressive pheresis can effectively treat symptoms associated with acute leukostasis. Finally, the continuous-flow cell separator has distinct advantages over the discontinuous-flow separator in patients with small blood volumes.

Adult↗
PubMedDate not supplied

A model for the study of granulocyte concentrate preservation.

An inexpensive model system for the study of granulocyte concentrate preservation has been evaluated. Concentrates were collected from the same donors within one hour by manual and automated pheresis techniques. In both types of concentrates, phagocytosis, respiratory burst, microbial killing and cell migration were normal within four hours of collection. Granulocyte function defects induced by 24- to 48-hour storage were similar in both types of concentrates; consequently, granulocyte concentrates collected as described here should serve as a useful model for the investigation of granulocyte concentrate preservation.

Blood Bactericidal Activity↗
PubMedDate not supplied

Decreased affinity for a chemotactic factor in stored granulocyte concentrates.

Previous studies in this laboratory demonstrated decreased migration of neutrophils after storage for 24 hours at room temperature. The current work was undertaken to identify a possible mechanism for decreased migration after storage. Initial studies ruled out the possibility that chemotaxis was decreased due to impaired ability to sense a chemotactic factor gradient since chemokinesis was decreased in addition to chemotaxis. Dose-response curves to the synthetic chemotactic agent Formyl-Methionyl-Leucyl-Phenylalanine (FMLP) showed decreased response to submaximal chemokinetic stimuli in stored neutrophils. This suggested the possibility of altered FMLP receptor binding in stored neutrophils. Neutrophil FMLP receptors were measured in 11 fresh and stored granulocyte concentrates. Although there was a small increase in total FMLP receptors per neutrophil after storage, the affinity of FMLP receptors in fresh neutrophils was significantly greater than that in neutrophils stored 24 hours at room temperature. Thus, decreased migration toward submaximal chemotactic stimuli in stored neutrophils may be due to altered membrane FMLP binding. However, decreased migration of stored neutrophils to maximal stimuli cannot be explained by altered FMLP binding affinity.

Blood Preservation↗
PubMedDate not supplied

Glycolytic enzymes of stored granulocytes.

A marked reduction of granulocyte chemotactic function accompanies the storage of granulocyte concentrates. Since chemotaxis is energy dependent, we studied energy metabolism in stored neutrophils. We and others have reported that stored neutrophils have a defect in their energy metabolism. We found that defective adenosine triphosphate maintenance in stored neutrophils was occult in resting cells, but was unmasked by an energy-intensive stimulus, phagocytosis. In studies reported here, we sought to determine if defective adenosine triphosphate maintenance during granulocyte storage was related to altered glycolytic enzyme activity. We studied the activity of glycolytic enzymes in fresh and stored, resting and stimulated (opsonized zymosan) neutrophils. The following enzyme activities showed no major changes during storage, in resting or stimulated neutrophils: hexokinase, phosphofructokinase, aldolase, glucose phosphate isomerase, triose phosphate isomerase, glyceraldehyde phosphate dehydrogenase, phosphoglycerate kinase, phosphoglyceromutase, enolase, lactate dehydrogenase, glucose-6-phosphate dehydrogenase, glutathione reductase, and glutathione peroxidase. In contrast, pyruvate kinase activity consistently increased during storage. In 6 units, pyruvate kinase activity increased by 75 percent after 24 hours of storage at room temperature and by 198 percent after 48 hours. The storage-associated increase in pyruvate kinase activity was not inhibited by cycloheximide. Stimulation of neutrophils by phagocytosis of opsonized zymosan also produced striking increases in the pyruvate kinase activity of both fresh and stored cells. Additional studies indicated that the increases in pyruvate kinase activity observed during storage and after phagocytosis were associated with an increase in the availability of pyruvate kinase activity in the supernatant fraction of neutrophil sonicates. Total pyruvate kinase activity in sonicates of neutrophils was unchanged by storage or particle ingestion.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenosine Diphosphate↗
PubMedDate not supplied

Hydrogen ion maintenance improves the chemotaxis of stored granulocytes.

Through technological advances in granulocyte collection, it has become possible to collect neutrophils (PMNs) routinely in high concentration (greater than 5 X 10(7) PMN/ml) for transfusion. Previous studies in this laboratory suggested that storage of neutrophils for transfusion at high PMN concentrations resulted in impaired adenosine triphosphate (ATP) and hydrogen ion maintenance. The studies we report here were designed to assess the effect of PMN storage at concentrations which are usual (2 X 10(7) PMN/ml), intermediate (5 X 10(7) PMN/ml), and high (8 X 10(7) PMN/ml) on chemotactic responses, and to identify variables which are easily measured and might predict the chemotactic function of stored PMNs. Granulocyte concentrates were stored in plastic bags at 2,5, and 8 X 10(7) PMN per ml, with or without 15 mM bicarbonate (HCO3). The random migration (RM) chemotaxis (CTX), ATP, and relative cell size (VOL) of the fresh and stored cells and the pH, glucose, and lactate concentrations in the supernatant medium were measured in the freshly prepared units after 24 and 48 hours storage at room temperature. We found that RM, CTX, ATP, glucose, and pH decreased significantly (p less than .02) following storage for 24 and 48 hours, particularly in units stored at the higher cell concentrations. Cell volume and lactate increased significantly with storage for 24 and 48 hours, and these values were also greater in units stored at the higher cell concentration (p less than .02).(ABSTRACT TRUNCATED AT 250 WORDS)

Adenosine Triphosphate↗
PubMedDate not supplied

The effect of storage on degranulation by human neutrophils.

We investigated the possibility that the functional impairment in neutrophil (PMN) chemotaxis which occurs during granulocyte concentrate storage might be due to autotoxicity from the release of neutrophil granule contents during storage. Preliminary experiments confirmed that the exposure of fresh PMNs to the intracellular contents of disrupted PMNs, decreased the subsequent chemotaxis of the fresh PMNs by 63 +/- 5 percent compared to control PMNs (p less than .01). Freshly harvested neutrophils were stored at low (2 X 10(7) PMN/ml) or high cell concentration (8 X 10(7) PMN/ml) with or without 15 mM sodium bicarbonate (in order to maintain pH). Prior to storage, and 24 and 48 hours after storage at 22 to 24 degrees C, we measured the cell and unit plasma content of lactate dehydrogenase (LDH), beta-glucuronidase, and lysozyme. These enzymes served as markers for cell lysis, and primary and specific neutrophil granule contents, respectively. We also measured the effect on neutrophil chemotaxis of adding a protease inhibitor, phenylmethylsulfonyl fluoride (PMSF), to the storage medium. In addition, we measured the ability of PMNs to degranulate in response to an inflammatory stimulus before and after storage. The cell content of granule markers was largely unchanged during storage, except in the case of the units at a concentration of 8 X 10(7) PMN per ml stored without bicarbonate. In these units, lysozyme activity decreased by 15 +/- 7 percent after 48 hours of storage (p less than 0.02 vs. fresh PMNs). Likewise, the plasma content of LDH, beta-glucuronidase, and lysozyme increased significantly during storage, especially in units of high cell concentration stored without bicarbonate.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Preservation↗
PubMedDate not supplied

Glycogen metabolism in stored granulocytes.

Optimal function of transfused granulocytes (PMNs) requires adequate glycogen metabolism. Previous studies in our laboratory suggested that stored PMNs had decreased glycogen. We report here the glycogen content and chemotaxis of stored PMNs, and the ability of fresh and stored PMNs to use glycogen as the fuel source for chemotaxis. PMNs were prepared from 8 fresh units of blood drawn into citrate-phosphate-dextrose-adenine, suspended at 2 or 8 X 10(7) PMN per ml in autologous plasma with or without 15 mM sodium bicarbonate, and stored at 22 to 24 degrees C in transfer packs for 48 hours. Glycogen was measured on resting PMNs, and after challenge with opsonized zymosan and F-Met-Leu-Phe (FMLP). The chemotaxis of fresh and stored PMNs was measured in the presence or absence of extracellular glucose. Fresh PMNs contained 10.3 +/- 0.5 (mean +/- SEM) micrograms of glycogen per 10(6) PMN. Glycogen decreased by 4.2 +/- 0.9 micrograms per 10(6) PMN after challenge with opsonized zymosan and by 1.1 +/- 0.6 micrograms per 10(6) PMN after FMLP. After 48 hours of storage, neutrophil glycogen increased by 18 percent, except in units stored at a concentration of PMN of 8 X 10(7) per ml without sodium bicarbonate. In PMNs from these units stored without bicarbonate, glycogen decreased by 9 percent (p less than .05), and there was a 19 and 55 percent decrease in the ability of PMN from these units to metabolize glycogen after exposure to opsonized zymosan and FMLP, respectively (p less than 0.05). In addition, in PMNs from units stored at a concentration of PMN of 8 X 10(7) per ml without bicarbonate, there was a 47 and 70 percent decrease in chemotaxis at 24 and 48 hours, respectively (p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Glucose↗
PubMedDate not supplied

B antigen acquired by normal A1 red cells exposed to a patient's serum.

The authors report a patient with the acquired B antigen whose serum contained a factor capable of inducing the acquired B phenotype on normal A1 red cells in vitro. The patient's red cells were not, however, agglutinated by a monoclonal anti-B. These findings and the abolition of the acquired B antigen by treatment of the patient's red cells with acetic anhydride support the deacetylation theory of the genesis of the acquired B antigen.

ABO Blood-Group System↗
PubMedDate not supplied

Adherence of fresh and stored granulocytes to endothelial cells. Effect of storage temperature.

Granulocyte (PMN) concentrates collected for transfusion to septic, neutropenic patients are stored in the blood bank for various periods of time before they are given. Current methods of blood bank storage of PMN concentrates are associated with impaired in vitro PMN chemotaxis (CTX) and in vivo recovery and circulation kinetics after 24 hours of storage. This suggested the possibility that PMN may become hyperadherent during storage. To test this hypothesis, PMN concentrates were harvested and stored at both 22 and 6 degrees C and their adherence properties to relevant biologic surfaces, endothelial cell (EC) monolayers, and extracellular matrix (ECM) derived from endothelium were measured. Adherence was measured within 4 hours of collection and after 24 and 48 hours of storage. The aggregation properties of fresh and stored PMN were also studied. The adherence of fresh, unstimulated PMN to EC and ECM (31 +/- 5% and 34 +/- 4%, respectively) increased significantly after storage for 24 hours (EC = 41 +/- 8%; ECM = 43 +/- 4%) at 22 degrees C. F-Met-Leu-Phe (FMLP) stimulated the adherence of fresh PMN (EC = 37 +/- 4%; ECM = 42 +/- 4%; p less than 0.05). The adherence of PMN stored at 22 degrees C was further stimulated by FMLP (EC = 46 +/- 6%; ECM = 50 +/- 4%). PMN stored at 6 degrees C had significantly higher adherence than PMN stored at 22 degrees C, and the percentage of increase in adherence induced by FMLP was attenuated in PMN stored at 6 degrees C.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Specimen Collection↗
PubMedDate not supplied

Stimulus-response coupling in fresh and stored granulocytes.

Granulocytes stored in the blood bank prior to transfusion undergo progressive decrements in their ability to circulate and migrate in vivo and to migrate in vitro (chemotaxis). The pathogenesis of granulocyte (PMN) chemotaxis (CTX) dysfunction after room-temperature storage of PMN is unclear. Previous work in the authors' laboratory and others led to the hypothesis that intracellular transmission of chemotactic signals, referred to as stimulus-response coupling (SRC), might be abnormal in stored PMN. This report presents an investigation of the ability of fresh and stored PMN to generate and respond to leukotriene-B4 (LTB4), the chief intracellular amplifier of SRC for CTX. PMN were sampled from concentrates within 4 hours of collection and after 24 and 48 hours of storage in transfer packs at room temperature (RT). Fresh, stimulated PMN synthesized 202 +/- 51 ng of LTB4 and 110 +/- 11 ng of 5-hydroxyeicosatetraenoic acid (HETE) per 10(7) PMN. Synthesis of LTB4, but not HETE was significantly decreased after 24 hours' storage, and LTB4 and HETE synthesis decreased after 48 hours. The incubation of stored PMN with arachidonic acid (AA) maintained levels of LTB4 synthesis in PMN stored for 24 but not 48 hours. Also, the CTX defect of stored PMN to F-Met-Leu-Phe (FMLP) was not improved by the supplementation of PMN with exogenous sources of LTB4 or AA.(ABSTRACT TRUNCATED AT 250 WORDS)

Arachidonic Acid↗
PubMedDate not supplied

Chemotaxin receptor cycling in fresh and stored granulocytes.

The authors reported previously that stored granulocytes (PMN) had decreased receptor affinity (Kd) for and chemotaxis (CTX) to the chemotactic peptide F-Met-Leu-Phe (FMLP), but the evidence did not favor a significant role for altered FMLP receptor affinity in causing diminished CTX of stored PMN. Since recruitment and/or recycling of FMLP receptors is required for normal CTX, the hypothesis that stored PMN might have abnormal FMLP receptor cycling was tested. The effect of storage on the proportion of high- and low-affinity FMLP receptors was also investigated. Units of PMN were tested within 4 hours of collection and after 24 and 48 hours of storage at 22 degrees C, unagitated, in 150-ml transfer packs. In comparison to fresh PMN, there was no alteration in the Kd of the high-affinity FMLP receptor of PMN stored for 24 to 48 hours; however, the Kd of the low-affinity receptor increased (fresh PMN = 36 +/- 5 nM; 24 hours = 107 +/- 19; 48 hours = 121 +/- 22; p less than 0.01 for both 24 and 48 h versus fresh PMN). Likewise, while the number of high-affinity receptors increased (fresh PMN = 25,000 +/- 6,000 receptors/PMN; 24 hours = 95,000 +/- 21,000; 48 hours = 161,000 +/- 40,000; p less than 0.01 for both 24 and 48 hours versus fresh PMN). No abnormality was found in the ability of stored PMN to down-regulate FMLP receptors in the presence of ligand or to reexpress FMLP receptors after a 15-minute incubation in the absence of ligand.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Preservation↗
PubMedDate not supplied

Reduction in the toxicity of a component of an artificial blood substitute by supercritical fluid fractionation.

Artificial blood substitutes (ABS) containing the surfactant Pluronic F68 (F68) are reported to be cytotoxic to cell lines. Because of F68's reported impairment of granulocyte function, it was hypothesized that F68 was also responsible for the cytotoxicity of ABS, possibly as a result of a separable fraction of the F68, separation of which could be achieved using supercritical fluid fractionation (SFF). SFF employs gases, such as carbon dioxide, under high pressure to dissolve the parent compound, a process that is followed by step-by-step precipitation and recovery of the dissolved material. The toxicity of F68 to human and animal cells was investigated by culturing Hela and B16 cells in the presence or absence of F68. Cells were grown for 4 days, harvested, and counted. Hela and B16 growth were markedly inhibited by F68. Four lots of F68 at 20 mg per ml inhibited Hela growth by 54 +/- 10 percent (p less than 0.05). In four dose-response experiments, three lots of F68 caused 50 percent inhibition of cell growth at 25 +/- 17 mg per ml. Four lots of F68 were also processed by SFF. Hela cells were grown in the presence of control media, parent (unextracted) F68, the early fractions of SFF extraction (XT), and the residual (partially purified) (RES F68). All parent F68, XT, and RES F68 were at 20 mg per ml. In 11 studies, the XT were 77 +/- 25 percent more toxic than the parent F68 (p less than 0.02), and the RES F68 were 30 +/- 11 percent less toxic than parent F68 (p less than 0.02).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗