Samples from pre- and post-rigor cod mince, surimi (a concentrate of fish myofibrillar proteins obtained after washing and dewatering the fish mince) and water from the first wash in the surimi manufacture, processed with and without the addition of 7.5 mM CaCl2 and 15 mM MgCl2, were analyzed by two-dimensional electrophoresis. The results showed that the main myofibrillar proteins, including myosin, actin and tropomyosin, remained in the surimi. Several other proteins were selectively removed during the washing procedure. Some additional major spots were detected in the two-dimensional gels containing samples of the wash water and surimi processed with the addition of Ca2+ and Mg2+ salts. These spots were either absent or present in minor amounts in the samples of post-rigor cod mince, wash water and surimi processed without Ca2+ and Mg2+ salts and in all the pre-rigor samples. This induced us to suggest that the new additional spots may constitute fragments of proteins originated by increased proteolytic activity during the surimi manufacture upon the addition of the Ca2+ and Mg2+ salts. Two-dimensional electrophoresis has proved to be a valuable tool to quickly and easily assess the effect of different processing conditions on the protein content of the products.

Animals↗

PubMed1989

Centrifugation of very freshly donated blood may yield platelets unstable to storage in the new generation of containers.

The stability of platelets stored in the second generation of container has been examined further. Platelet concentrates prepared in CPD anticoagulant were found to deteriorate fairly rapidly during storage if prepared from very freshly donated blood, whereas a more than 4-hour delay between donation and platelet isolation yielded platelet concentrates much more stable to storage. Delays of more than 2 h (relative to the time of donation) in the isolation of platelets led to decreases in the aggregation response to low or moderate doses of collagen. Platelets from blood collected into CPD adenine showed decreased aggregation responses relative to equivalent cells from blood collected into adenine-free anticoagulant. It seems that a decreased aggregation response is associated with improved storage properties.

Adenine↗

PubMed1988

Effect of centrifugation on the storage properties of platelets.

Some of the recommended centrifugation methods for the preparation of platelet concentrates may cause accelerated deterioration of platelets stored in second-generation containers. The deterioration is characterized by increasing pH, pO2 and decreasing pCO2, a high discharge of lactate dehydrogenase (LDH) and increasing amounts of small particles which have recently been shown to have platelet factor 3 activity [Solberg, C.; Osterud, B.; Little, C.: Thrombosis Res. 48: 559-565, 1987]. A short first centrifugation (3,270 g, 2 min 15 s) yielded platelets with better storage properties than platelet-rich plasma prepared with longer centrifugation times (2,200 g, 4 min 30 s and 1,100 g, 6 min). By using multivariate data analysis the effect of different platelet concentrations and metabolic parameters can be used to predict the discharge of LDH or the change in morphology.

Anticoagulants↗

PubMed1988

Storage of human red blood cells and platelets. Some aspects concerning the factors leading to storage lesion characterized as morphological changes and vesiculation. Minireview based on a doctoral thesis.

1. Storage renders erythrocytes more responsive to thermally induced morphological changes, especially the shedding of microvesicles. 4-8 week old cells can be morphologically "rejuvenated" by heating. 2. If pH increases during storage of platelets an extensive loss of small particles occurs. The platelet disintegration is associated with a loss in the metabolic activity, discharge of LDH, increased susceptibility to phospholipid hydrolysis by phospholipase C and is found to be initiated during the actual preparation of platelet concentrates. 3. Activation of platelets during preparation can be decreased by shortening the first centrifugation time or by using adenine in the anticoagulant. 4. A 4 hour prestorage of the whole blood unit prior to centrifugation strongly decreases the activation of platelets upon stimuli and results in platelet concentrates much more stable to storage.

Blood Platelets↗

PubMed1987

Platelet storage lesion: formation of platelet fragments with platelet factor 3 activity.

Certain samples of stored platelet concentrates exhibited marked platelet factor 3 activity. This activity was associated almost completely with platelet fragments formed during storage. Platelet concentrates containing high levels of these fragments and hence high platelet factor 3 activity were characterized after storage by alkaline plasma pH values, high levels of extracellular lactate dehydrogenase activity and relatively low cell counts.

Blood Platelets↗

PubMed1986

Morphological changes associated with pH changes during storage of platelet concentrates in first-generation 3-day container.

The platelet injury and loss of viability that has been shown to occur with storage of platelet concentrates (PC) under conditions with increasing or falling pH were examined using scanning and transmission electron microscopy. After storage, samples were taken for measurement of pH value, platelet count and size distribution, release of lactate dehydrogenase (LDH) into plasma, and for SEM and TEM. Increased levels of LDH were observed in PC with pH above 7.3 and below 6.1. In PC with pH above 7.3 this was related to an increased number (23%) of platelets that were lysed or had a swollen disintegrated internal structure (balloons) as seen with TEM. SEM and Coulter counter studies also showed that platelet fragmentation and formation of microvesicles were prominent in PC with pH above 7.3. The electron microscopic pictures confirmed previous suggestions that platelet disc-to-sphere transformation and cytoplasmic swelling occur when pH falls below 6.7-6.8 during storage. SEM studies showed that concomitant with this change, folds and bulky projections appeared on the platelet surface. In PC with pH below 6.1 the morphological change was irreversible with the appearance of more than 90% lysed and balloon platelets. In conclusion, these studies suggest that the loss of viability observed with PC with pH above 7.3 or below 6.1 after storage is related to an increased percentage of lysed and balloon platelets.

Blood Platelets↗

PubMed1986

Morphological changes associated with pH changes during storage of platelet concentrates.

The platelet injury and loss of viability that has been shown to occur with storage of platelet concentrates (PC) under conditions with increasing or falling pH were examined using scanning and transmission electron microscopy. After storage of PC in first (PL-146) and second generation containers (PL-1240 and PL-732), samples were taken for measurement of pH value, platelet count and size distribution, release of lactate dehydrogenase (LDH) into plasma, and for SEM and TEM. After storage of 83 PC in first generation containers for 4 days increased levels of LDH were observed in PC with pH above 7.3 (n = 2) and below 6.1 (n = 4). The electron microscopic pictures confirmed previous suggestions that platelet disc-to-sphere transformation and cytoplasmic swelling occur when pH falls below 6.7-6.8 during storage. In PC with pH below 6.1 the morphological change was irreversible with the appearance of more than 90% lysed and balloon platelets. In PC with pH above 7.3 because of low platelet concentration this was related to an increased number of platelets that were lysed of had a swollen disintegrated internal structure (balloons) as seen with TEM. SEM and Coulter counter studies also showed that platelet fragmentation and formation of microvesicles were prominent in PC with pH above 7.3. Second generation containers maintained the pH during 5-day-storage at higher levels but had enhanced risk of pH increase. A strong tendency for the platelets to become alkaline upon subsequent storage could be demonstrated as a result of excessive forces or prolonged centrifugation during the second spin of the preparation procedure. Whereas the platelet injury caused by low pH is easy to recognize because of the absence of swirling the morphological changes associated with high pH cannot be detected directly.

Acid-Base Equilibrium↗

PubMed1984

Effect of phospholipase C (Bacillus cereus) on freshly isolated and 4-day-stored human platelets.

Phospholipase C (from Bacillus cereus) was used to study fresh and stored human platelets. Provided that the enzyme was inactivated before lipid extraction, no significant degradation of phospholipid in fresh cells was noted, even when platelets were activated or induced to change shape by ADP, collagen or thrombin. With platelets isolated from concentrates stored for transfusion for 4 days at 22 degrees C, membrane phospholipids were degraded by the enzyme to an extent depending on the pH in the platelet concentrate at day 4 of storage. The extent of phospholipid hydrolysis in platelets correlated well with the extent of release of lactate dehydrogenase during storage, with both being minimal for platelets from concentrates of final pH 6.5-6.9. Under non-lytic conditions, phosphatidylcholine was the phospholipid most degraded (40%), with no significant degradation of phosphatidylserine being detected. Storage does not seem to alter the distribution of phospholipids at the external leaflet of the plasma membrane.

Bacillus cereus↗

PubMedDate not supplied

Barriers & breakthroughs in EDI.

Explore the source record for details and available documents.

Computer Communication Networks↗

PubMedDate not supplied

Measuring outcomes. The search for answers.

Outcomes are among the most precious gems in healthcare right now. Finding the necessary data and using it to save both money and lives, however, can be a challenge. The National Committee on Quality Assurance (NCQA) has released a set of guidelines for collecting and measuring outcomes. But even officials with NCQA insist that information technology is the only realistic way to find this valuable resource.

Cost Savings↗