scholarly journals A Method for Preservation of Viable Platelets: Combined Effects of Sugars and Dimethylsulfoxide

Blood ◽  
1963 ◽  
Vol 22 (6) ◽  
pp. 703-717 ◽  
Author(s):  
ISAAC DJERASSI ◽  
ALBERT ROY
Keyword(s):  
Liquid Nitrogen ◽  
Bleeding Time ◽  
Combined Effects ◽  
Simultaneous Presence ◽  
Cent Dextrose ◽  
Rat Platelets

Abstract Rat platelets were frozen in liquid nitrogen (-195 C.) without losing their morphologic integrity and their ability to circulate in thrombocytopenic recipient animals. The simultaneous presence of two preservative agents—a sugar and dimethylsulfoxide—was instrumental in this respect. The use of single agents was only slightly or not at all effective. The combination of 5 per cent Dextrose and 5 per cent DMS in plasma permitted in individual experiments a circulating yield of frozen platelets as high as 70 to 87 per cent of the numbers observed when fresh platelets were given. The bleeding time was reduced to normal whenever the platelet levels were increased to more than 300,000/mm3.

Combined effects of a factor Xa inhibitor YM466 and a GPIIb/IIIa antagonist YM128 on thrombosis and neointima formation in mice

2004 ◽  
Vol 92 (12) ◽  
pp. 1221-1228 ◽  
Author(s):  
Yoshiyuki Iwatsuki ◽  
Kazumi Hayashi ◽  
Yumiko Moritani ◽  
Tomoko Nii ◽  
Keiji Miyata ◽  
...  
Keyword(s):  
Platelet Aggregation ◽  
Vascular Injury ◽  
Coronary Angioplasty ◽  
Bleeding Time ◽  
Factor Xa ◽  
Neointima Formation ◽  
Combined Effects ◽  
Test Drug ◽  
Thrombotic Occlusion ◽  
Acute Thrombosis

SummaryThrombosis and neointima formation limit the efficacy of coronary angioplasty. Factor Xa inhibitors and GPIIb/IIIa antagonists have shown to be effective on acute thrombosis and late neointima formation, however, their combined effects remain to be elucidated. Vascular injury was induced by FeCl3 in the carotid artery in mice. For thrombosis studies, the test drug was orally administered 1 hour before vascular injury. For neointima studies, the test drug was orally administered 1 hour before and twice daily for 1 week after vascular injury, and then histological analysis was performed 3 weeks after vascular injury. YM466 inhibited thrombotic occlusion at 30 mg/kg with prolongation of prothrombin time (PT), and tail transection bleeding time (BT) was affected at 100 mg/kg. YM466 also inhibited neointima formation at 10 mg/kg. YM128 inhibited thrombotic occlusion and neointima formation at 10 and 30 mg/kg, respectively, with inhibition of platelet aggregation and prolongation of BT. In contrast, the combination of 10 mg/kg YM466 and 3 mg/kg YM128 inhibited thrombotic occlusion and neointima formation without affecting PT, platelet aggregation and BT. Concomitant inhibition of factor Xa and GPIIb/IIIa may provide a safer and more effective therapeutic regimen for treatment of coronary angioplasty.

Combined Effects of 2D and 3D Inhomogeneities on the Dynamic Susceptibility of Superlattices

2010 ◽  
Vol 168-169 ◽  
pp. 97-100
Author(s):  
V.A. Ignatchenko ◽  
D.S. Tsikalov
Keyword(s):  
Density Of States ◽  
Three Dimensional ◽  
Wave Number ◽  
Dynamic Susceptibility ◽  
Combined Effects ◽  
Two Dimensional ◽  
Simultaneous Presence ◽  
One Dimensional ◽  
The One ◽  
2D And 3D

The dynamic susceptibility and the one-dimensional density of states (DOS) of an initially sinusoidal superlattice (SL) with simultaneous presence of two-dimensional (2D) phase inhomogeneities that simulate the deformations of the interfaces between the SL’s layers and three-dimensional (3D) amplitude inhomogeneities of the layer material of the SL were investigated. An analytical expression for the averaged Green’s function of the sinusoidal SL with 2D phase inhomogeneities was obtained in the Bourret approximation. It was shown that the effect of increasing asymmetry of heights of the dynamic susceptibility peaks at the edge of the Brillouin zone of the SL, which was found in [6] at increasing the rms fluctuations of 2D inhomogeneities, also takes place at increasing the correlation wave number of such inhomogeneities. It was also shown that the increase of the rms fluctuations of 3D amplitude inhomogeneities in the superlattice with 2D phase inhomogeneities leads to the suppression of the asymmetry effect and to the decrease of the depth of the DOS gap.

scholarly journals Hereditary Defect in Platelet Function in Rats

Blood ◽  
1972 ◽  
Vol 40 (2) ◽  
pp. 217-226 ◽  
Author(s):  
Thomas B. Tschopp ◽  
Marjorie B. Zucker
Keyword(s):  
Bleeding Time ◽  
Platelet Rich Plasma ◽  
Release Mechanism ◽  
Hemorrhagic Diathesis ◽  
Platelet Concentrates ◽  
Plasma Factor ◽  
Hereditary Defect ◽  
Platelet Release ◽  
Induced Aggregation ◽  
Rat Platelets

Abstract Hemostatic parameters of fawn-hooded (FH) rats with an inherited hemorrhagic diathesis were compared with those of normal rats. Prothrombin time, partial thromboplastin time, plasma factor VIII, plasma fibrinogen, and platelet count and volume were normal. Bleeding time (BT) in FH rats was over 15 min vs. 1-8 min in controls, and platelet retention in glass-bead columns was reduced. Transfusion of platelet concentrates from normal rats corrected the BT of thrombocytopenic FH rats, but FH rat platelets did not shorten the BT of thrombocytopenic controls. ADP-induced aggregation, measured turbidimetrically in heparinized FH platelet-rich plasma, was normal. Connective tissue did not aggregate platelets of FH rats and released a subnormal amount of 14C-serotonin. In comparison with control platelets washed FH platelets aggregated by thrombin released virtually no ATP and ADP. Platelets, 10,11 of normal rats contained 4.49 µmoles ATP, 0.98 µmoles ADP, and 0.88 µmoles serotonin compared with only about one-half as much ATP and ADP and one-third as much serotonin in platelets of FH rats. These low values suggest the absence of the platelet, "release pool" rather than a defective release mechanism. The hemorrhagic diathesis seen in the FH rats resembles the platelet defect with storage pool deficiency observed in man.2

scholarly journals Prolonged Bleeding Time With Defective Platelet Filopodia Formation in the Wistar Furth Rat

Blood ◽  
1998 ◽  
Vol 91 (5) ◽  
pp. 1599-1608 ◽  
Author(s):  
Paula E. Stenberg ◽  
Rosemary J. Barrie ◽  
Tamara I. Pestina ◽  
Shirley A. Steward ◽  
Julie T. Arnold ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Platelet Adhesion ◽  
Bleeding Time ◽  
Early Time ◽  
Clot Formation ◽  
Time Points ◽  
Prolonged Bleeding ◽  
Prolonged Bleeding Time ◽  
Rat Platelets

Abstract Hereditary macrothrombocytopenia is a hallmark of Wistar Furth (WF) rats. In addition, a platelet/megakaryocyte alpha granule defect, similar to that of patients with gray platelet syndrome, is present. Several observations indicate cytoskeletal abnormalities in WF platelets and megakaryocytes, suggesting the potential for functional defects in hemostatic processes requiring cytoskeletal reorganization, such as platelet adhesion and spreading. However, no bleeding abnormality has been noted. Here, we report a prolonged bleeding time (>30 minutes in 10 of 11 rats tested) with defective clot formation in the WF strain. Prolonged bleeding time can result from defects in platelet adhesion, aggregation, or the release reaction. Because aggregation to collagen and adenosine diphosphate were reported to be normal, we determined whether WF rat platelets are defective in their ability to adhere to substrates. Platelet adherence and spreading was evaluated from 30 seconds to 30 minutes on Formvar-coated, carbon-stabilized grids or poly-L-lysine–coated glass coverslips by transmission electron microscopy or immunofluorescence, respectively, and scanning electron microscopy. We classified the adhered platelets according to their pattern of spreading, ie, rounded, rounded or spreading with short filopodia, spindle-shaped, spreading with long filopodia, spreading with lamellipodia, and fully spread. Adherent normal rat platelets displayed all stages of spreading within 30 seconds to 2 minutes, including many spindle-shaped forms, and forms with multiple, long filopodia. In contrast, adhered WF platelets at these early time points rarely developed long filopodia or were spindle shaped. The majority of adherent WF platelets at these early time points were either round, spread with a few short filopodia, or extensively spread with wide lamellipodial skirts. By 15 to 30 minutes, most platelets in both Wistar and WF samples were fully spread. These data show abnormal WF platelet spreading. The paucity of spindle-shaped forms and forms with long filopodia may reflect an inability of WF platelets to undergo the early stages of spreading, or, alternatively, their more rapid than normal progression through these stages. We hypothesize that this failure to spread normally may relate to prolonged bleeding times in vivo and defective clot formation in WF rats.

scholarly journals Hsp47 Inhibitor Col003 Attenuates Collagen-Induced Platelet Activation and Cerebral Ischemic–Reperfusion Injury in Rats

2022 ◽  
Vol 12 ◽  
Author(s):  
Shuang Wu ◽  
Chengwei Liang ◽  
Xiaoyun Xie ◽  
Haiping Huang ◽  
Jinfeng Fu ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Protective Effect ◽  
Reperfusion Injury ◽  
Bleeding Time ◽  
Mapk Signaling ◽  
Ischemic Reperfusion Injury ◽  
Ischemic Reperfusion ◽  
Cerebral Ischemic ◽  
Cerebral Ischemic Reperfusion ◽  
Rat Platelets

Ischemic stroke is a major type of stroke worldwide currently without effective treatment, although antiplatelet therapy is an existing option for it. In previous studies, heat shock protein 47 (Hsp47) was found to be expressed on the surface of human and mice platelets and to strengthen the interaction between platelets and collagen. In recent years, Col003 was discovered to inhibit the interaction of Hsp47 with collagen. We evaluated whether the Hsp47 inhibitor Col003 is a promising therapeutic agent for ischemic stroke. Here, we first verified that Hsp47 is also expressed on the surface of rat platelets, and its inhibitor Col003 significantly inhibited thrombus formation in the FeCl3-induced rat carotid arterial thrombus model. Both Col003 and clopidogrel did not alter the bleeding time or coagulation parameters, while aspirin increased the tail-bleeding time (p < 0.05). The low cytotoxicity level of Col003 to rat platelets and human liver cells was similar to those of aspirin and clopidogrel. Col003 inhibited collagen-induced platelet aggregation, adhesion, [Ca2+]i mobilization, P-selectin expression, reactive oxygen species production and the downstream signal pathway of collagen receptors. The results of the middle cerebral artery occlusion model indicated that Col003 has a protective effect against cerebral ischemic–reperfusion injury in rats. The Hsp47 inhibitor Col003 exerted antiplatelet effect and protective effect against brain damage induced by ischemic stroke through the inhibition of glycoprotein VI (GPVI)and mitogen-activated protein kinase (MAPK) signaling events, which might yield a new antiplatelet agent and strategy to treat ischemic stroke.

scholarly journals Prolonged Bleeding Time With Defective Platelet Filopodia Formation in the Wistar Furth Rat

Blood ◽  
1998 ◽  
Vol 91 (5) ◽  
pp. 1599-1608 ◽  
Author(s):  
Paula E. Stenberg ◽  
Rosemary J. Barrie ◽  
Tamara I. Pestina ◽  
Shirley A. Steward ◽  
Julie T. Arnold ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Platelet Adhesion ◽  
Bleeding Time ◽  
Early Time ◽  
Clot Formation ◽  
Time Points ◽  
Prolonged Bleeding ◽  
Prolonged Bleeding Time ◽  
Rat Platelets

Hereditary macrothrombocytopenia is a hallmark of Wistar Furth (WF) rats. In addition, a platelet/megakaryocyte alpha granule defect, similar to that of patients with gray platelet syndrome, is present. Several observations indicate cytoskeletal abnormalities in WF platelets and megakaryocytes, suggesting the potential for functional defects in hemostatic processes requiring cytoskeletal reorganization, such as platelet adhesion and spreading. However, no bleeding abnormality has been noted. Here, we report a prolonged bleeding time (>30 minutes in 10 of 11 rats tested) with defective clot formation in the WF strain. Prolonged bleeding time can result from defects in platelet adhesion, aggregation, or the release reaction. Because aggregation to collagen and adenosine diphosphate were reported to be normal, we determined whether WF rat platelets are defective in their ability to adhere to substrates. Platelet adherence and spreading was evaluated from 30 seconds to 30 minutes on Formvar-coated, carbon-stabilized grids or poly-L-lysine–coated glass coverslips by transmission electron microscopy or immunofluorescence, respectively, and scanning electron microscopy. We classified the adhered platelets according to their pattern of spreading, ie, rounded, rounded or spreading with short filopodia, spindle-shaped, spreading with long filopodia, spreading with lamellipodia, and fully spread. Adherent normal rat platelets displayed all stages of spreading within 30 seconds to 2 minutes, including many spindle-shaped forms, and forms with multiple, long filopodia. In contrast, adhered WF platelets at these early time points rarely developed long filopodia or were spindle shaped. The majority of adherent WF platelets at these early time points were either round, spread with a few short filopodia, or extensively spread with wide lamellipodial skirts. By 15 to 30 minutes, most platelets in both Wistar and WF samples were fully spread. These data show abnormal WF platelet spreading. The paucity of spindle-shaped forms and forms with long filopodia may reflect an inability of WF platelets to undergo the early stages of spreading, or, alternatively, their more rapid than normal progression through these stages. We hypothesize that this failure to spread normally may relate to prolonged bleeding times in vivo and defective clot formation in WF rats.

Electron Probe Microanalysis of Frozen Hydrated Kidneys, Isolated Cells, and Cultured Cells

1982 ◽  
Vol 40 ◽  
pp. 402-403 ◽  
Author(s):  
Claude Lechene
Keyword(s):  
Liquid Nitrogen ◽  
Electron Probe Microanalysis ◽  
Electron Probe ◽  
Cultured Cells ◽  
Liquid Nitrogen Temperature ◽  
Elemental Content ◽  
Isolated Cells ◽  
Renal Tubular Cells ◽  
Diamond Saw ◽  
Saw Blade

Electron probe microanalysis of frozen hydrated kidneysThe goal of the method is to measure on the same preparation the chemical elemental content of the renal luminal tubular fluid and of the surrounding renal tubular cells. The following method has been developed. Rat kidneys are quenched in solid nitrogen. They are trimmed under liquid nitrogen and mounted in a copper holder using a conductive medium. Under liquid nitrogen, a flat surface is exposed by sawing with a diamond saw blade at constant speed and constant pressure using a custom-built cryosaw. Transfer into the electron probe column (Cameca, MBX) is made using a simple transfer device maintaining the sample under liquid nitrogen in an interlock chamber mounted on the electron probe column. After the liquid nitrogen is evaporated by creating a vacuum, the sample is pushed into the special stage of the instrument. The sample is maintained at close to liquid nitrogen temperature by circulation of liquid nitrogen in the special stage.

A Liquid Nitrogen Cooled Stage for STEM

1974 ◽  
Vol 32 ◽  
pp. 444-445
Author(s):  
Louis T. Germinario
Keyword(s):  
Electron Microscope ◽  
High Resolution ◽  
Liquid Nitrogen ◽  
Room Temperature ◽  
Objective Lens ◽  
Thermal Drift ◽  
Specimen Holder ◽  
Resolution Capability ◽  
Focal Position

A liquid nitrogen stage has been developed for the JEOL JEM-100B electron microscope equipped with a scanning attachment. The design is a modification of the standard JEM-100B SEM specimen holder with specimen cooling to any temperatures In the range ~ 55°K to room temperature. Since the specimen plane is maintained at the ‘high resolution’ focal position of the objective lens and ‘bumping’ and thermal drift la minimized by supercooling the liquid nitrogen, the high resolution capability of the microscope is maintained (Fig.4).

Field-Ion Microscopy of BCC Metals: A Study of Image Differences and Topographical Variations

1973 ◽  
Vol 31 ◽  
pp. 114-115
Author(s):  
O. T. Inal ◽  
L. E. Murr
Keyword(s):  
Liquid Nitrogen ◽  
Liquid Nitrogen Temperature ◽  
Surface Atom ◽  
Image Brightness ◽  
Field Ion Microscopy ◽  
Topographic Features ◽  
Bcc Metals ◽  
Electron Orbital ◽  
Ion Microscopy ◽  
Field Ion Microscope

When sharp metal filaments of W, Fe, Nb or Ta are observed in the field-ion microscope (FIM), their appearance is differentiated primarily by variations in regional brightness. This regional brightness, particularly prominent at liquid nitrogen temperature has been attributed in the main to chemical specificity which manifests itself in a paricular array of surface-atom electron-orbital configurations.Recently, anomalous image brightness and streaks in both fcc and bee materials observed in the FIM have been shown to be the result of surface asperities and related topographic features which arise by the unsystematic etching of the emission-tip end forms.

The Effects of Drying Techniques on Clay-Rich Soil Texture

1974 ◽  
Vol 32 ◽  
pp. 466-467
Author(s):  
T. G. Naymik
Keyword(s):  
Critical Point ◽  
Liquid Nitrogen ◽  
Liquid Nitrogen Temperature ◽  
Drying Methods ◽  
Air Drying ◽  
Freeze Dried ◽  
Critical Point Drying ◽  
Set Up ◽  
The Relationship ◽  
Quartz Grains

Three techniques were incorporated for drying clay-rich specimens: air-drying, freeze-drying and critical point drying. In air-drying, the specimens were set out for several days to dry or were placed in an oven (80°F) for several hours. The freeze-dried specimens were frozen by immersion in liquid nitrogen or in isopentane at near liquid nitrogen temperature and then were immediately placed in the freeze-dry vacuum chamber. The critical point specimens were molded in agar immediately after sampling. When the agar had set up the dehydration series, water-alcohol-amyl acetate-CO2 was carried out. The objectives were to compare the fabric plasmas (clays and precipitates), fabricskeletons (quartz grains) and the relationship between them for each drying technique. The three drying methods are not only applicable to the study of treated soils, but can be incorporated into all SEM clay soil studies.

Sign in / Sign up

Export Citation Format

Share Document