Re: Putting vital stains in context

It has been shown (Yonge, 1932) that the integument of the Decapod Crustacea, as exemplified by the uncalcified lining of the foregut of the lobster, Homarus vulgaris , consists of two layers which differ widely in nature and origin. There is a thin superficial cuticle which is hyaline, possesses adsorbed lipin, and is formed by the widely distributed tegumental glands the function of which had previously been obscure. The actual chemical nature of this thin layer was not determined but it is not chitin from which it can be distinguished by a variety of chemical and physical tests. The underlying and much thicker layer of the integument consists of lamellated chitin formed by the cells of the epithelium. The present research was designed to determine in broad outline the permeability of this membranous integument, and in particular the influence upon this of the bounding cuticle and the general biological significance of the cuticle. In the Crustacea, Jordan and Lam (1918) found that the foregut and hindgut of Astacus , which are lined with chitin, behave as semipeimeable membranes, allowing water, but not dissolved substances, either electrolytes or non-electrolytes, to pass through under the influence of osmotic pressure. Similar results were obtained by Yonge (1924) with the foregut of Nephrops . Very different results were obtained from similar experiments with the midgut of both Astacus and Nephrops , indicating that the peculiar properties of the remainder of the gut are due to the chitinous lining. Murlin (1902) and Nicholls (1931) have shown that the chitin which lines the so-called midgut in Oniscus, Porcellio , and other land Isopoda, and in Ligia oceanica respectively, is permeable to the end-products of digestion. Krogh (1915) states that the gills of Astacus are practically impermeable to urethane. Fischel (1908), Koehring (1930, 1931), Gickelhorn (1931), and Bond (1933) have all found some evidence for the penetration of the integument of various Cladocera and Copepoda by vital stains.

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A STUDY OF THE COMBINED ACTION OF X-RAYS AND OF VITAL STAINS UPON PARAMŒCIA

Biological Bulletin ◽

10.2307/1536547 ◽

1920 ◽

Vol 39 (1) ◽

pp. 59-66 ◽

Cited By ~ 4

Author(s):

W. M. BALDWIN

Keyword(s):

X Rays ◽

Vital Stains ◽

Combined Action

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The death of human platelets during incubation in citrated plasma involves shedding of CD42b and aggregation of dead platelets

Thrombosis and Haemostasis ◽

10.1160/th05-06-0403 ◽

2006 ◽

Vol 95 (01) ◽

pp. 100-106 ◽

Cited By ~ 23

Author(s):

John Savill ◽

Simon Brown ◽

Paul Hartley

Keyword(s):

Platelet Rich Plasma ◽

Vital Staining ◽

Human Platelets ◽

Staining Procedure ◽

Aggregate Formation ◽

Factors Affecting ◽

Transmission Electron ◽

Reliable Assessment ◽

Vital Stains ◽

Calcein Am

SummaryThe ability to readily identify dead platelets is invaluable to studies examining the means of their death, factors affecting their lifespan and their means of clearance by phagocytes. The aim of the present work was to develop a vital staining procedure for the rapid and objective discrimination of live from dead platelets that accrued in citrated platelet rich plasma (cPRP) incubated at 37°C for several days. By transmission electron microscopy it was noted that platelet death was morphologically similar to necrosis and associated with aggregate formation. The vital dyes calcein-AM and FM 4–64 were found to robustly report the death of platelets and indicated that the aggregates which formed during incubation were populated exclusively by dead platelets. Additionally, platelet death was associated with the shedding of CD42b. Microscopic and cytometric analyses of incubated cPRP indicated that shedding of CD42b and aggregate formation by dead platelets were completely inhibited by the metalloproteinase inhibitor GM6001. Automated counting of platelets incubated in the presence of GM6001 revealed that death did not lead to a loss in cellularity. It is proposed that calcein-AM and FM4–64 are effective as vital stains for the reliable assessment of platelet viability and that platelet aggregation can occur by a novel mechanism dependent upon platelet death and metalloproteinase activity.

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