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PubMed1979

The utilisation of a new strength citrate anticoagulant during centrifugal plateletpheresis. III. Assessment of in vitro platelet metabolism.

Employing the Haemonetics Blood Processor (IFC), a relatively pure platelet concentrate can be prepared by collecting only the first portion of the PRP leaving the centrifuge bowl (Fraction I). A subsequent fraction containing RBC and WBC contaminants (Fraction II) can be purified by means of a second centrifugation, using a conventional blood bank centrifuge (Fraction II), if transfusion of these contaminants would be detrimental to the recipient. Utilising the new 1.4% Na3-citrate anticoagulant, platelet metabolic parameters (ATP, ADP, AMP, lactate and pyruvate) as well as O2-uptake, were determined in Fraction I and II prepared from 10 normal healthy subjects. In contrast to previous studies reporting marked dysfunction in platelets contained in Fraction II when standard ACD-A was used during IFC, we observed no significant difference (Student's t test) in the present study between Fractions I and II, in regard to platelet metabolism, when using the new anticoagulant. It is further concluded that the second centrifugal manipulation does not exert a detrimental effect on platelet metabolism.

Anticoagulants↗
PubMed1996

Effect of surface roughness on hemolysis in a pivot bearing supported Gyro centrifugal pump (C1E3).

The blood contacting surface quality is an important pump parameter for blood compatibility and cell damage. This study investigates the surface roughness and the effect it has on hemolysis in a centrifugal blood pump. In vitro hemolysis tests were performed with a pivot bearing supported Gyro centrifugal pump (C1E3) simulating cardiopulmonary bypass (CPB; 5 L/min, 350 mm Hg) and left ventricular assist device (LVAD; 5 L/min, 100 mm Hg) conditions. To produce 4 different grades of surface roughness, the impellers and housings were subjected to vapor polishing, sand papering, fine sand blasting, or coarse sand blasting. Seven pumps were assembled with different impeller and housing surfaces. These surfaces were then examined by a surface profile instrument and a scanning electron microscope. The results of this study are as follows. First, the effect of surface roughness on hemolysis was significantly greater in the CPB condition than in the LVAD condition. Second, surface roughness, regardless of whether it is the impeller or pump housing, had little effect on hemolysis in the LVAD condition. Third, in the CPB condition, the surface roughness of the pump housing has a greater effect on hemolysis than does that of the impeller. From a hemolytic point of view, an extremely smooth pump housing is required for use of an impeller type centrifugal pump as a CPB device. In contrast, it is conceivable that a smooth surface is not always essential for an impeller type centrifugal pump that is used as an LVAD.

Animals↗
PubMed1996

The effect of the impeller-driver magnetic coupling distance on hemolysis in a compact centrifugal pump.

Blood trauma is one of the important performance parameters of centrifugal pumps. To investigate the blood trauma induced by these pumps, in vitro hemolysis tests have become an important procedure and are increasingly used for pump development and comparisons. The Baylor compact eccentric inlet port (CIE) centrifugal blood pump was developed as a long-term centrifugal ventricular assist device (VAD) as well as a cardiopulmonary bypass pump (CPB). The Baylor CIE pump incorporates a seal-less design with a blood stagnation-free structure. This pump can provide flows of 5 L/min against 350 mm Hg of total pressure head at 2,600 revolutions per minute. The pump impeller is magnetically coupled to the driver magnet in a seal-less manner. The latest hemolysis study revealed that hemolysis may be affected by the gap distance between the driver and the impeller magnet. The purpose of this study was to verify the effect of the magnetic coupling distance on the normalized index of hemolysis (NIH) with the CIE model and to obtain an optimal gap distance. The NIH value was clearly decreased by alteration of the magnetic coupling distance from 7.7 to 9.7 mm in CPB and left ventricular assist device (LVAD) conditions. The NIH, when using the pump as an LVAD condition, was reduced to a level of 0.0056 from 0.095 when the magnetic coupling distance was extended. The same results were also obtained when the pumps were used in a CPB condition. The magnetic coupling distance is an important factor for the CIE model in terms of hemolysis. Different coupling forces effect the bearings and impeller stability. These results suggest that an optimal driving condition with a proper magnetic coupling and an optimal force between the impeller and driver is necessary to develop an atraumatic centrifugal pump.

Blood Flow Velocity↗
PubMed1997

Clinical evaluation of the centrifugal pump in open heart surgery: a comparative study of different pumps.

The centrifugal pump is now widely used in open heart surgery for its clinical benefits related to the blood elements and the coagulation system. The purpose of this study was to compare the clinical performances of and the outcomes offered by 4 types of centrifugal pumps. For each pump, we investigated the effects on the blood elements, coagulation system, complements, and immunoglobulins during open heart surgery. Four types of centrifugal pumps were used: the HPM-15 (Nikkiso Co.), the Capiox (Terumo Co.), the Lifestream (St. Jude Medical Co.), and the BP-80 (Medtronic, BioMedicus Co.). The platelet count, lactate dehydrogenase (LDH), antithrombin III (AT III), thrombin-antithrombin complex (TAT), complements (C3, C4, and CH50), and immunoglobulins (IgG, IgA, and IgM) were measured before and after cardiopulmonary bypass (CPB). The platelet count was decreased more significantly by the HPM-15 than by any of the other pumps. The other parameters showed no difference among the 4 pumps. In clinical use, each of the 4 types of centrifugal pumps was safe.

Aged↗
PubMed2006

In vitro study to estimate particle release from a centrifugal blood pump.

Centrifugal pumps have been increasingly used in clinical settings. Like roller pumps, centrifugal pumps can cause debris release due to mechanical stress. The objectives of this study were to evaluate in vitro the particle release from a centrifugal pump, Gyro Pump (Japan Medical Materials Co., Osaka, Japan), which is a pivot-bearing supported pump clinically used in Japan, and to identify the released particles. In the clean room Class 10,000, the pump was operated for 24 h at 4000 rpm and 6 L/min in a mock loop filled with lactated Ringer's solution. After 24 h, the sample fluid and a blank were filtered with a 0.45-microm membrane filter for microscopic counting, followed by observation with a scanning electron microscope and element analysis with an X-ray spectrometer. Microscopic countings were 128 +/- 42 in the test samples (n = 10) of the Gyro Pump and 98 +/- 42 in the blank samples (n = 10) (P = 0.12). The oxygen/carbon atomic ratio of the particles in the test samples was 0.32 +/- 0.06, which was similar to the ratio of the particles in the blank sample (0.34 +/- 0.06). The profiles of elements with an X-ray spectrometer showed that the released particles from the Gyro Pump were not derived from the pump materials. In conclusion, an in vitro test system has been established for estimation of particle release from a centrifugal pump. Based upon the results with the system, the Gyro Pump with a pivot-bearing system has little risk to release debris particles even in a severe condition.

Aluminum Oxide↗
PubMed1994

Effects of centrifugation and specimen preparation technique on bronchoalveolar lavage analysis in horses.

Bronchoalveolar lavages (BAL) were performed for 6 healthy horses and 8 horses with lower airway diseases (LAD). Total cell and differential counts were performed before and after centrifugation and resuspension of the BAL cells in a small volume of fluid; there was no difference in the total cell counts, but mast cell percentages were significantly (P < 0.05) lower, after centrifugation, in the LAD group. The two specimen preparation techniques compared were cytocentrifugation and centrifugation on microscope glass covers. For both groups of horses, lymphocyte percentages were significantly lower on cytocentrifuged specimens; there was also an increase in the other predominant cell type, i.e. macrophages in healthy horses and neutrophils in horses with LAD. Lymphocyte percentages in healthy horses were higher than those reported in previous studies, possibly because of a long-standing exposure to a high-dust environment. This study suggests that one centrifugation of the BAL fluid does not affect total cell counts, but may cause a decrease in mast cell percentage; cytocentrifugation is associated with a consistent decrease in lymphocyte percentage.

Animals↗
PubMed1969

Bovine splenic nerve: characterization of noradrenaline-containing vesicles and other cell organelles by density gradient centrifugation.

1. Homogenates of bovine splenic nerves were subjected to differential and sucrose density gradient centrifugation. From the low-speed supernatant a high-speed sediment (mitochondria, lysosomes, microsomes and noradrenaline (NA) vesicles) was obtained. By density gradient centrifugation of this sediment it was shown that NA vesicles are slightly less dense than mitochondria, but denser than microsomes.2. In further experiments a mitochondrial and a microsomal sediment were obtained. The mitochondrial sediment was fractionated with a short centrifugation time over a density gradient ranging from 0.6 to 1.2 M sucrose. Mitochondria (fumarase and succinate-dehydrogenase) and lysosomes (acid ribonuclease and deoxyribonuclease) sedimented to the bottom of the tube. The highest concentration of NA vesicles was found in a medium position. There was only a small amount of microsomes (glucose-6-phosphatase) present.3. The microsomal sediment was centrifuged for 150 min over a density gradient ranging from 0.8 to 1.4 M sucrose. The microsomes remained on the top of the gradient. There were also some mitochondria and lysosomes present. The NA vesicles were found in highest concentration in the middle of the gradient (at about 1.2 M sucrose).4. With the use of these two density gradients, the subcellular distribution of dopamine-beta-hydroxylase, monoamine oxidase and ATPase was studied. Dopamine-beta-hydroxylase was found to be localized in the NA vesicles. Monoamine oxidase was mainly recovered in mitochondria; a small part of the enzyme appeared to be microsomal. ATPase was present in microsomal elements.

Adenosine Triphosphatases↗
PubMed1982

Enhanced phagocytic response of macrophages to bacteria by physical impact caused by bacterial motility or centrifugation.

The mechanism of enhanced phagocytic and chemiluminescent responses of macrophages caused by bacterial motility (T. Tomita, E. Blumenstock, and S. Kanegasaki, Infect. Immun. 32:1242, 1981) was studied. Both responses increased up to a certain level with an increased number of motile bacteria, such as Salmonella typhimurium, Escherichia coli, or Pseudomonas aeruginosa, added. In contrast, only a slight increase was observed with the motility (mot) mutants of these bacteria, even when 4,000 bacteria per single macrophage were added. If nonmotile bacteria were centrifuged together with a monolayer culture of macrophages, the number of bacteria ingested per macrophage increased dramatically. This phenomenon was not observed in the presence of cytochalasin B or at a low temperature, and about half of the associated bacteria were killed within 30 min of prolonged incubation, indicating that the bacteria were not simply embedded on the macrophage surface. An observed biphasic increase of ingestion with an increase in centrifugal force suggested the existence of a threshold velocity for efficient phagocytosis. The minimum centrifugal force required for maximal response was determined under the conditions in which equalized collision frequency between bacteria and macrophages was maintained when different centrifugal forces were employed. From the value obtained (5 x g), the required rate of movement was calculated as approximately 2.5 microns/s, supposing that the bacterium is spherical and has a 1-micron radius. This value is much lower than the velocity of movement of motile bacteria (20 to 50 microns/s). The results indicate that physical impact caused by bacterial motility is enough to induce a high response of macrophages.

Centrifugation↗
PubMed1984

Clinical evaluation of the lysis-centrifugation blood culture system for the detection of fungemia and comparison with a conventional biphasic broth blood culture system.

In a comparative fungal blood culture study, a lysis-centrifugation system (Isolator; Du Pont Co., Wilmington, Del.) detected 89% of all episodes of fungemia; the lysis-centrifugation system detected fungemia exclusively or significantly earlier than did a biphasic brain heart infusion bottle system 83% of the time. The lysis-centrifugation system was particularly useful in the early detection of fungemia caused by Candida tropicalis and Candida glabrata. In 53% of the clinically significant episodes, the earlier detection was directly helpful in the management of patients with fungemia. High-magnitude candidemia (greater than 5 CFU/ml of blood) was significantly associated with the presence of an infected intravascular catheter and with Candida species other than Candida albicans. The lysis-centrifugation system was sensitive in the detection of fungemia during the monitoring of patients receiving antifungal agents or after removal of an infected intravascular catheter.

Candidiasis↗
PubMed1984

Comparison of lysis-centrifugation with lysis-filtration and a conventional unvented bottle for blood cultures.

Evaluation of a commercially available lysis-centrifugation blood culture system (Isolator, DuPont Co., Wilmington, Del.) and a lysis-filtration blood culture system for 3,111 cultures showed that both methods had comparable recoveries (73 and 68%, respectively) of significant aerobic and facultatively anaerobic isolates. The unvented conventional blood culture bottle had a recovery rate of 59%. Although the lysis-centrifugation and lysis-filtration systems had comparable recoveries of pathogens, the lysis-centrifugation system had the advantage of having colonies immediately available for further testing. The contamination rate with the lysis-centrifugation system was 3%, compared with 6% with the lysis-filtration system and 0.4% with brain heart infusion.

Bacteria↗
PubMed1989

Detection of cytomegalovirus from clinical specimens in centrifugation culture by in situ DNA hybridization and monoclonal antibody staining.

An in situ DNA hybridization kit for cytomegalovirus (CMV) was evaluated for the detection of CMV in centrifugation culture. Of 61 clinical specimens, 17 (27.8%) were positive for CMV by monoclonal antibody staining following centrifugation. Of the 17 positive specimens, 15 were detected by DNA hybridization (24.5%). However, the earliest that CMV could be detected by DNA hybridization was 58 h as compared with 16 h with monoclonal antibodies following centrifugation. DNA hybridization remains of great interest for the study and detection of CMV infection. However, current DNA hybridization techniques are not sufficiently rapid to replace the use of monoclonal antibodies in centrifugation culture.

Antibodies, Monoclonal↗
PubMed1990

Enhancing effect of centrifugation on isolation of influenza virus from clinical specimens.

The use of centrifugation (700 x g, 60 min) in a plaque assay markedly increased (mean, 2.9-fold) the infectivity of all 42 influenza virus strains tested, compared with no centrifugation. Of 13 influenza virus strains isolated from 390 clinical specimens, 9 (69%) were efficiently isolated by the centrifugation assay compared with conventional culture methods. The centrifugation assay may be useful for isolating the influenza virus from clinical specimens.

Centrifugation↗
PubMed1976

Blood culture technique based on centrifugation: developmental phase.

A quantitative and flexible blood culture system based on centrifugation of lysed blood over a density layer is described. The effect of relative centrifugal force, centrifugation time, and two different density solutions on the recovery of Staphylococcus aureus, Escherichia coli, pseudomonas aeruginosa, and Candida albicans was determined. To demonstrate the versatility of this technique, the reisolation of 23 representative microorganisms from inoculated normal human blood was determined at a fixed centrifugation speed and time. The potential merits of this technique are discussed and compared with those of conventional blood culture methods.

Blood↗
PubMed1976

Blood culture technique based on centrifugation: clinical evaluation.

A total of 1,000 blood samples from patients suspected of having a bacteremia were analyzed concurrently, where possible, by three methods: (i) Trypticase soy broth with sodium polyanethol sulfonate and a CO2 atmosphere: (ii) pour plates with either brain heart infusion agar or Sabouraud dextrose agar; and (iii) centrifugation of the suspected organism in a hypertonic solution. There were 176 positive cultures. The centrifugation technique recovered 73% of the positive cultures. The broth and pour plate techniques recovered 38 and 49%, respectively. The centrifugation technique showed an increased isolation rate for Pseudomonas, fungi, and gram-positive cocci. In general, for each organism the time required for the detection of a positive culture was shortest for the centrifugation technique.

Bacteria↗
PubMed1992

Detection of human cytomegalovirus in clinical specimens by centrifugation culture with a nonhuman cell line.

The sensitivities of MRC-5 and mink lung (ML) cells in centrifugation culture were compared simultaneously for the detection of cytomegalovirus (CMV) IE antigen (immediate-early antigen) from clinical specimens. Of 413 samples assayed, 51 (12%) were positive for CMV by both centrifugation and standard cell culture. At 20 h postinoculation (p.i.), 46 of 51 (90.2%) CMV-positive specimens were detected in ML cells. At 40 h p.i., 50 of 51 (98.0%) CMV-positive specimens were detected in ML cells, compared with 48 of 51 (94.0%) in MRC-5 cells. There was no significant difference in the detection of CMV in either cell line by centrifugation culture. However, in 19 of 23 positive samples that had countable foci at 20 h p.i., there was a 25% increase in the number of positive foci observed for ML cells compared with MRC-5 cells. Less toxicity was also noted for ML cells than for MRC cells, particularly in viral blood specimens. These data suggest that ML cells are comparable to MRC-5 cells for the rapid detection of CMV by centrifugation culture.

Animals↗
PubMed2002

Isolation of interstitial fluid from rat mammary tumors by a centrifugation method.

Access to interstitial fluid is of fundamental importance to understand tumor transcapillary fluid balance, including the distribution of probes and therapeutic agents. Tumors were induced by gavage of 9,10-dimethyl-1,2-benzanthracene to rats, and fluid was isolated after anesthesia by exposing tissue to consecutive centrifugations from 27 to 6,800 g. The observed (51)Cr-EDTA (extracellular tracer) tissue fluid-to-plasma ratio obtained from whole tumor or from superficial tumor tissue by centrifugation at 27-424 g was not significantly different from 1.0 (0.92-0.99), suggesting an extracellular origin only. However, fluid collected from excised central tumor parts had a significantly lower ratio (0.66-0.77) for all imposed G forces, suggesting dilution by fluid deriving from a space unavailable for (51)Cr-EDTA. The colloid osmotic pressure in tumor fluid was generally higher than in fluid isolated from the subcutis, attributable to less selective capillaries and impaired lymphatic drainage in tumors. HPLC analysis of tumor fluid showed that low-molecular-weight macromolecules not present in arterial plasma were present in tumor fluid obtained by centrifugation and in venous blood draining the tumor, most likely representing proteins derived from tumor cells. We conclude that low-speed centrifugation may be a simple and reliable method to isolate interstitial fluid from tumors.

Animals↗
PubMed1975

Increased uptake and utilization of glucose by diaphragms of rats exposed to chronic centrifugation.

Weaning female Sprague-Dawley rats were exposed to 2.76 or 4.15 G for periods ranging from 2 to 20 wk. The isolated diaphragm tissues from these rats were studied in vitro to determine the uptake of glucose and its utilization to CO2 and glycogen. The diaphragm muscle tissues obtained from centrifuged rats showed higher rates of glucose uptake and 14CO2 production from [U-14C]glucose than those obtained from noncentrifuged controls, but no significant differences in the rate of incorporation of [U-14C]glucose into glycogen were observed. Rats centrifuged for 12 wk at 4.15 G continued to show an increase in diaphragm tissue glucose uptake for periods up to 2 wk after return to normal gravity. The stimulating effect of insulin on the uptake of glucose and its incorporation into glycogen was much higher in the diaphragms of centrifuged rats. From the results of this study, it is concluded that one of the adaptive responses of rats to chronic centrifugation is an increase in glucose metabolism of their muscle tissues.

Adaptation, Physiological↗
PubMed1989

Complement activation in plasma exchange by single filtration and centrifugation and in cascade filtration.

C3d was assayed in samples of blood plasma obtained before and after centrifugation, single filtration or cascade filtration, and also in samples of waste plasma obtained after termination of exchange. In blood plasma, cascade filtration was followed by an increase of the mean C3d concentration from 20 to 50 mU/l (p less than 0.001, n = 15), whereas single filtration and centrifugation were followed by a minor decrease. Waste plasma of cascade and single filtration contained 113 +/- 42 mU/exchange (n = 15, mean +/- SD) and 83 +/- 46 mU/exchange (n = 8), respectively. In centrifugation, the concentration of C3d of waste plasma never exceeded that of blood plasma, and the total amount of C3d of waste plasma was only 4 +/- 6 mU/exchange. In contrast to filtration, the centrifugation technique seemed not to be afflicted with any increase in the break down of complement component C3.

Blood Proteins↗