Resolution of Fine Structure in Ionization‐Efficiency Curves

Platelet adhesion initiates platelet aggregation and is an important component of the hemostatic process. Since the development of a new form of collagen as a topical hemostatic agent is of both basic and clinical interest, an ultrastructural and hematologic study of the interaction of platelets with the microcrystalline collagen preparation was undertaken.In this study, whole blood anticoagulated with EDTA was used in order to inhibit aggregation and permit study of platelet adhesion to collagen as an isolated event. The microcrystalline collagen was prepared from bovine dermal corium; milling was with sharp blades. The preparation consists of partial hydrochloric acid amine collagen salts and retains much of the fibrillar morphology of native collagen.

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Pituitary Follicular Cells: Their Origin, Possible Function and Fate

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100050184 ◽

1974 ◽

Vol 32 ◽

pp. 34-35

Author(s):

E. Horvath ◽

K. Kovacs ◽

G. Penz ◽

C. Ezrin

Keyword(s):

Fine Structure ◽

Secretory Granules ◽

Follicular Cells ◽

Human Pituitary ◽

Rat Pituitary ◽

Pituitary Glands ◽

Junctional Complexes

Follicular structures, in the rat pituitary, composed of cells joined by junctional complexes and possessing few organelles and few, if any, secretory granules, were first described by Farquhar in 1957. Cells of the same description have since been observed in several species including man. The importance of these cells, however, remains obscure. While studying human pituitary glands, we have observed wide variations in the fine structure of follicular cells which may lead to a better understanding of their morphogenesis and significance.

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Ultrastructure and Staining of Developing Elastic Tissue

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100065274 ◽

1971 ◽

Vol 29 ◽

pp. 244-245

Author(s):

E. N. Albert

Keyword(s):

Fine Structure ◽

Phosphotungstic Acid ◽

Staining Method ◽

Rat Aorta ◽

Uranyl Acetate ◽

The Other ◽

Elastic Fibers ◽

Elastic Tissue ◽

Lead Citrate ◽

New Born

Silver tetraphenylporphine sulfonate (Ag-TPPS) was synthesized in this laboratory and used as an electron dense stain for elastic tissue (Fig 1). The procedures for the synthesis of tetraphenylporphine sulfonate and the staining method for mature elastic tissue have been described previously.The fine structure of developing elastic tissue was observed in fetal and new born rat aorta using tetraphenylporphine sulfonate, phosphotungstic acid, uranyl acetate and lead citrate. The newly forming elastica consisted of two morphologically distinct components. These were a central amorphous and a peripheral fibrous. The ratio of the central amorphous and the peripheral fibrillar portion changed in favor of the former with increasing age.It was also observed that the staining properties of the two components were entirely different. The peripheral fibrous component stained with uranyl acetate and/or lead citrate while the central amorphous portion demonstrated no affinity for these stains. On the other hand, the central amorphous portion of developing elastic fibers stained vigorously with silver tetraphenylporphine sulfonate, while the fibrillar part did not (compare figs 2, 3, 4). Based upon the above observations it is proposed that developing elastica consists of two components that are morphologically and chemically different.

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The Dermal Glands of Rhodnius Prolixus

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100063202 ◽

1969 ◽

Vol 27 ◽

pp. 258-259

Author(s):

J. E. Lai-Fook

Keyword(s):

Fine Structure ◽

Secretory Activity ◽

Rhodnius Prolixus ◽

Outermost Layer ◽

Cement Layer ◽

Dermal Glands

Dermal glands are epidermal derivatives which are reported to secrete either the cement layer, which is the outermost layer of the epicuticle or some component of the moulting fluid which digests the endocuticle. The secretions do not show well-defined staining reactions and therefore they have not been positively identified. This has contributed to another difficulty, namely, that of determining the time of secretory activity. This description of the fine structure of the developing glands in Rhodnius was undertaken to determine the time of activity, with a view to investigating their function.

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