PubMed · 211769
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J L David. 1977. [Platelet adhesion and aggregation].. https://doi.org/10.1080/17843286.1977.11717889
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The Food and Drug Administration (FDA) is reclassifying the automated differential cell counter (ADCC) from class III (premarket approval) into class II (special controls). FDA is also identifying the guidance document entitled "Class II Special Controls Guidance Document: Premarket Notifications for Automated Differential Cell Counters for Immature or Abnormal Blood Cells; Final Guidance for Industry and FDA" as the special control that the agency believes will reasonably ensure the safety and effectiveness of the device. This reclassification is being undertaken based on new information submitted in a reclassification petition from the International Society for Laboratory Hematology (ISLH), under the Federal Food, Drug, and Cosmetic Act (the act), as amended by the Safe Medical Devices Act of 1990 and the FDA Modernization Act of 1997.
The computer and the digital camera offer unprecedented possibilities for improving hematology education, research, and patient service. Peripheral blood smear images of exceptional quality can be acquired rapidly and conveniently from the peripheral blood smear with a modern, high-resolution digital camera and a quality microscope. Digital cameras use CCD or CMOS image sensors to measure light energy and additional circuitry to convert the measured information into a digital signal. Because digital cameras do not use photographic film, images are immediately available for incorporation into web sites or digital publications, printing, transfer to other individuals by e-mail, or other applications. Several excellent consumer digital still cameras are now available for less than $1000 that capture high-quality images comprised of more than three megapixels. These images are essentially indistinguishable from conventional film images when viewed on a quality color monitor or printed on a quality color or black and white printer at sizes up to 8 x 10 in. Several recent dedicated digital photomicroscopy cameras provide an ultrahigh quality image output of more than 12 megapixels and have low noise circuit designs permitting the direct capture of darkfield and fluorescence images. There are many applications of digital images of peripheral blood smears. Because hematology is a visual science, the inclusion of quality digital images into lectures, teaching handouts, and electronic documents is essential. A few institutions have gone beyond the basic application of digital images to develop large electronic hematology atlases; animated, audio-enhanced learning experiences; multidisciplinary Internet conferences; and other innovative applications. Digital images of single microscopic fields (single-frame images) are the most widely used in hematology education at this time, but single images of many adjacent microscopic fields can be stitched together to prepare zoomable panoramas that encompass a large part of a microscope slide and closely stimulate observation through a real microscope. With further advances in computer speed and Internet streaming technology, the virtual microscope could easily replace the real microscope in pathology education. Interactive, immersive computer experiences may completely revolutionize hematology education and make the conventional lecture and laboratory format obsolete later in this decade. Patient care is enhanced by the transmission of digital images to other individuals for consultation and education, and by the inclusion of these images in patient care documents. In research laboratories, digital cameras are widely used to document experimental results and obtain experimental data.
Platelets, which have an important role in hemostatic mechanisms and which were prepared by single and random methods were investigated to measure quantity, and aggregation response during 5 days of storage. The aggregation response and quantitative values of platelet concentrates (PCs), 60 of which were prepared by a single donor method and 62 by a random method were investigated during the 1st, 3rd, and 5th days of storage. The single donor platelets (SDP) were obtained by using the MCS Plus apheresis device and the random donor platelets (RDP) were obtained by two-phase centrifugation in the Heraeus 8500i centrifuge device (during the first phase, platelet rich plasma was obtained then platelet concentrate was obtained from this product) and were stored at 22 degrees C on a circular agitator. In addition, pH, PO2, PCO2, glucose and lactate values were measured in order to evaluate the effects of storage. The aggregation response was measured using adenosine diphosphate (ADP), epinephrine (EPN), collagen (COLL) and ristocetin (RIST). The cell count in mm3 and the total cell count were also measured. The total cell counts and cells in mm3 of the PCs which were prepared by the single donar method on the 1st, 3rd and 5th days, were: 3.11 x 10(11), 3.09 x 10(11), 3.07 x 10(11) and 292 x 10(3), 290 x 10(3), 289 x 10(3) and of those prepared by the random method were: 5.71 x 10(10), 5.69 x 10(10), 5.66 x 10(10) and 156 x 10(3), 153 x 10(3), 151 x 10(3). The mean aggregation responses of the PCs prepared by the two methods on the 1st, 3rd and 5th days, expressed as a % were: ADP: 94.8-93.2, 81.6-78.7, 44.3-8.2; COLL: 91.7-89.6, 79.2-74.2, 29.8-11.1; EPN: 88.5-91.3, 64.2-62.7, 39.4-4.5 and RIST: 89.4-89.4, 76.5-73.6, 14.4-3.2. Other data related to platelet storage were obtained by measuring the pH, PO2, PCO2, glucose and lactate levels of the PCs. In our study, it was determined that in spite of the optimal storage conditions, the aggregation response of the PCs decreased significantly, whereas, the numerical values changed little during the storage period.