New Technique for Microscopic Examination of the Fouling Community of Submerged Opaque Surfaces

We have recently presented a new technique for occlusion of long standing fistulae by excochleation and plugging with a fibrin clot (Lancet, 1979). The intention with the technique was to keep the fistulous tract dry and occluded by a species-specific substance until healing had occurred. To study the importance of the fibrin clot in the present context an experimental study in rats has been performed. Perforated Teflon cylinders were implanted subcutaneously, removed after 1, 2 and 4 weeks and subjected to macro-and microscopic examination. Comparison was made between empty cylinders and cylinders filled with a fibrin clot.The examination after one week revealed the initially fibrin clot filled cylinders still to be filled by the clot. Ingrowth of granulation tissue through the cylinder perforations had started. The initially empty cylinders were still empty. At the 2-week examination the initially fibrin clot filled cylinders were at the peripheral half filled by ingrowing granulation tissue, the central half was filled by the implanted fibrin clot. The initially empty cylinders were filled to a lesser degree by ingrowing granulation tissue and a loose exdogenous clot centrally.The 4-week examination revealed both the initially empty and the initially fibrin clot filled cylinders to be completely filled up by granulation tissue of varying organisation.During the time it takes for the granulation tissue to grow into the cylinder the clot remains intact centrally and together they keep the cylinder filled up. It furthermore appears as if the fibrin clot induces a more rapid ingrowth into the cylinder. Both observations confirms the importance of the clot for the fistula occlusion.

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Properties of Isolated Mitochondria of Agaricus Bisporus: Their Relationship to Dormancy and the Germination of Spores

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100072733 ◽

1973 ◽

Vol 31 ◽

pp. 458-459

Author(s):

K. S. McCarty ◽

R. F. Weave ◽

L. Kemper ◽

F. S. Vogel

Keyword(s):

Mitochondrial Dna ◽

Ethidium Bromide ◽

Microscopic Examination ◽

Agaricus Bisporus ◽

Osmotic Shock ◽

Electron Microscopic Examination ◽

Electron Microscopic ◽

Isolated Mitochondria ◽

Dna Strands ◽

Cytoplasmic Ribosomes

During the prodromal stages of sporulation in the Basidiomycete, Agaricus bisporus, mitochondria accumulate in the basidial cells, zygotes, in the gill tissues prior to entry of these mitochondria, together with two haploid nuclei and cytoplasmic ribosomes, into the exospores. The mitochondria contain prominent loci of DNA [Fig. 1]. A modified Kleinschmidt spread technique1 has been used to evaluate the DNA strands from purified whole mitochondria released by osmotic shock, mitochondrial DNA purified on CsCl gradients [density = 1.698 gms/cc], and DNA purified on ethidium bromide CsCl gradients. The DNA appeared as linear strands up to 25 u in length and circular forms 2.2-5.2 u in circumference. In specimens prepared by osmotic shock, many strands of DNA are apparently attached to membrane fragments [Fig. 2]. When mitochondria were ruptured in hypotonic sucrose and then fixed in glutaraldehyde, the ribosomes were released for electron microscopic examination.

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Artifact-free electron microscopic immunocytochemistry on rat brain tissue

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100085666 ◽

1991 ◽

Vol 49 ◽

pp. 272-273

Author(s):

Veronika Burmeister ◽

N. Ludvig ◽

P.C. Jobe

Keyword(s):

Microscopic Examination ◽

Free Electron ◽

Electron Microscopic Examination ◽

Ultrastructural Localization ◽

Rabbit Serum ◽

Electron Microscopic ◽

Electron Microscopic Immunocytochemistry ◽

Phosphate Buffered Saline ◽

Rat Brain Tissue ◽

Immune Rabbit

Electron microscopic immunocytochemistry provides an important tool to determine the ultrastructural distribution of various molecules in both normal and pathologic tissues. However, the specific immunostaining may be obscured by artifactual immunoreaction product, misleading the investigator. Previous observations show that shortening the incubation period with the primary antibody from the generally used 12-24 hours to 1 hour substantially reduces the artifactual immunostaining. We now extend this finding by the demonstration of artifact-free ultrastructural localization of the Ca2/calmodulindependent cyclic nucleotide phosphodiesterase (CaM-dependent PDE) immunoreactivity in brain.Anesthetized rats were perfused transcardially with phosphate-buffered saline followed by a fixative containing paraformaldehyde (4%) and glutaraldehyde (0.25%) in PBS. The brains were removed, and 40μm sections were cut with a vibratome. The sections were processed for immunocytochemistry as described by Ludvig et al. Both non-immune rabbit serum and specific CaM-dependent PDE antibodies were used. In both experiments incubations were at one hour and overnight. The immunostained sections were processed for electron microscopic examination.

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Ineffective Thrombopoiesis

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100158881 ◽

1990 ◽

Vol 48 (3) ◽

pp. 266-267

Author(s):

JM Radley ◽

SL Ellis

Keyword(s):

Microscopic Examination ◽

Phosphate Buffer ◽

Primary Myelofibrosis ◽

Transient Increase ◽

Major Difficulty ◽

Adult Mice ◽

Dense Cytoplasm

In effective thrombopoies is has been inferred to occur in several disease sates from considerations of megakaryocyte mass and platelet kinetics. Microscopic examination has demonstrated increased numbers of megakaryocytes, with a typical forms particularly pronounced, in primary myelofibrosis. It has not been documented if megakaryocyte ever fail to reach maturity in non-pathological situations. A major difficulty of establishing this is that the number of megakaryocytes normally present in the marrow is extremely low. A large transient increase in megakaryocytopoiesis can how ever be induced in mice by an injection of 5-fluorouracil. We have utilised this treatment and report here evidence for in effective thrombopoies is in healthy mice.Adult mice were perfused (2% glutaraldehyde in 0.08M phosphate buffer, pH 7.4) 8 days following an injection of 5-fluorouracil (150mg/kg). Femurs were subsequently decalcified in 10% neutral E.D.T.A. and embedded in Spurrs resin. Transverse sections of marrow revealed many megakaryocytes at various stages of maturity. Occasional megakaryocytes (less than 1%) were found to be under going degeneration prior to achieving full maturation and releasing cytoplasm as platelets. These cells were characterized by a peripheral rim of dense cytoplasm which enveloped a mass of organelles and vacuoles (Fig. 1). Numerous microtubules were foundaround and with in the organelle-rich zone (Fig 2).

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