James H. Martin

Spinal melanotic clear‐cell sarcoma: A light and electron microscopic study

We report a melanotic spindle‐cell tumor that arose from a thoracic spinal nerve root and metastasized to both lungs. The bulk of the tumor consisted of glycogen‐rich clear cells and bore a striking resemblance on light and electron microscopy to at least one variant of the clear‐cell sarcoma of tendons and aponeuroses. The presence of schwannoma‐like areas noted in the primary tumor on light microscopy and the formation of a highly developed basal lamina noted on ultrastructural examination suggest that the tumor may be a partially dedifferentiated malignant melanotic schwannoma. This tumor is discussed in the context of a simple histogenetic classification of melanotic tumors.

Crystals in a Gastric Schwannoma

A gastric schwannoma containing large numbers of intracytoplasmic crystals is described. The latter are compared with intracytoplasmic crystals found in the cells of other tumors and their nonneoplastic cell counterparts. The extreme morphologic and histochemical heterogeneity of the different types of crystals is emphasized.

Ultrastructural evidence for astroglial histogenesis of the monstrocellular astrocytoma (so-called monstrocellular sarcoma of brain)

Five astrocytomas grade III to IV, three fibrosarcomas and two so‐called monstrocellular sarcomas were compared by light and electron microscopy in an attempt to determine the histogenesis of the last neoplasm. The bizarre giant cells characteristic of the monstrocellular tumor were found to be quite similar to those of the grade III to IV astrocytomas. Ultrastructural similarities between the monstrocellular tumor and astrocytomas and dissimilarities between these tumors and fibrosarcomas support an astrocytic origin; the authors suggest that these peculiar tumors be called monstrocellular astrocytomas or astrocytoma: monstrocellular variant.

Pulmonary blastoma: An ultrastructural study emphasizing intestinal differentiation in lung tumors

Features of intestinal differentiation, including the presence of brush borders, have been described previously in a pulmonary blastoma following xenotransplantation in athymic nude mice. This paper reports similar findings in a pulmonary blastoma subjected directly to electron microscopic study. Ultrastructural manifestations of intestinal differentiation in other types of primary lung tumors are also discussed.

Ultrastructure of calciphylaxis in skin

Abstract Rats weighing approximately 100 grams were given, by stomach tube, dihydrotachystrol (DHT) in corn oil. After 29 hours a small area of the skin on the dorsum of the neck was traumatized by pinching it with hemostats. The animals were divided into ten groups and sacrificed after trauma; 5 minutes, 10 minutes, 30 minutes, 1 hour, 2 hours, 4 hours, 8 hours, 16 hours, 24 hours, and 48 hours. These specimens were fixed in osmium and embedded in Epon for electron microscopy. Except for the crush damage as a result of the trauma, the cells of the dermis and epidermis showed little change until 4 hours, when the fibrocytes began to accumulate electron dense material in their mitochondria, and the Golgi complex became larger demonstrating large vesicle formation on the Golgi secretory face. The electron dense material in the mitochondria was lost contiguous with the accretion of electron dense material in the large Golgi vesicles of the involved fibrocytes. Microincineration demonstrated a significant accumulation of mineral ash within the mitochondria and vesicles. Vesicles were secreted from the cells into the matrix by 24 hours, and by 48 hours apatite formation was observed within the vesicles and extended from them to the surrounding collagenous matrix. The fibrocytes that produced mineral laden vesicles showed normal ultra-structure following loss of vesicles. The calci-phylactic response involves selective cell calcium and phosphate sequestration into mitochondria, coupled with intracellular production of mineral loaded vesicles that directly nucleate matrix mineralization following secretion.. Pretreatment of rats with 2mg/Kg EHDP for 6 days is characterized by an absence of mineral laden vesicles. Comparable vesicles are not noted in normal cartilage, bone or skin. Osmium pyroantimonate fixed cartilage, however, does demonstrate mineral containing microvesicies in the cytoplasm.

Studies on delayed (cellular) hypersensitivity in mice infected with Trichinella spiralis. 8. Serologic and histopathologic responses of recipients injected with spleen cells from donors suppressed with ATS.

Spleen cells were collected from sensitized donors that had been suppressed with antithymocyte serum (ATS) for 16 consecutive days after a second sensitization with an antigen-adjuvant mixture. These cells were injected ip into mice of Recipient Group A. Ten days later, they were challenged with 100 T. spiralis larvae, and after 2 and 10 days some of the mice were killed for collection of tissue from the small intestine for histopathologic studies. Mice of Recipient Group B were injected with spleen cells from sensitized, nonsuppressed donors and those of Recipient Group C were injected with cells from nonsensitized, nonsuppressed donors. Other than the source of the spleen cells, the recipients of groups B and C were treated in the same manner as those of Group A. Blood for later serologic testing was taken from all recipients killed 10 days after infection. At 2 days after challenge, the tissues of the recipients (B) of cells from the sensitized, nonsuppressed donors showed evidence of acute inflammation, whereas such evidence was not detected in the mucosa and submucosa of recipient groups A and C. At 10 days, tissues from mice of all 3 recipient groups showed acute inflammation, but the response was much more severe in groups A and B than that observed in group C, and it was more severe in Group B than in Group A. Therefore, the transfer of cells from the sensitized, nonsuppressed donors resulted in an earlier initiation and a more acute degree of inflammation after challenge, and the cells transferred from the sensitized, suppressed donors resulted in effects in recipients that were intermediate between the former and those injected with cells from nonsensitized, nonsuppressed donors. As noted in various earlier histopathologic studies of the small intestine of our mice, the severity of the inflammation was associated directly with the numbers of worms recovered. The serologic results with a battery of tests were inconclusive. In the final experiment of the previous paper of this series (Larsh et al., 1972), it was demonstrated that donor mice sensitized twice by footpad injections of an antigenadjuvant mixture and suppressed with antithymocyte serum (ATS) for 27 consecutive days after the second sensitization harbored about the same numbers of worms after challenge as the regular controls that had not been sensitized or suppressed. Inasmuch as other donors that were sensitized in the same way as the former group but not suppressed harbored significantly fewer worms after challenge, it was clear that the immunosuppressive effect of ATS had abolished completely the expression of the immunity produced by the Received for publication 9 July 1973. * Supported in part by Grant AI-10671 from

The ultrastructural immunocytochemical localization of superoxide dismutase in the amphibian urinary bladder: effect of aldosterone

SummaryTransmission electron microscopy and immunohistochemistry, the latter employing the avidin—biotin—peroxidase (ABC complex) technique, were utilized to localize copper—zinc superoxide dismutase (CuZn—SOD) enzyme activity in the epithelial cells of the toad urinary bladder mucosa. This ‘scavenger’ enzyme catalyses the dismutation (reduction—oxidation) of the superoxide anion (O2−), a toxic free radical generated during normal cellular respiration. In unstimulated epithelial cells, enzyme activity was seen in the cytosol of granular, mitochondrial-rich and goblet cells. The basal cells were generally devoid of enzyme activity. In addition to the cytosol, SOD activity was also seen in association with the apical plasma membrane of the epithelial cells. In the presence of the steroid hormone aldosterone (10−7m, 30 min—6 h), CuZn—SOD activity was markedly increased along the luminal mucosal membrane of granular, mitochondrial-rich and goblet cells. This increase was seen as early as 30 min after the addition of hormone, and as long as 6 h after treatment. The cytosolic reaction was usually decreased or absent under these conditions. From the data presented, it appears that CuZn—SOD is involved in electrolyte (sodium) transport in the epithelial cells of the toad urinary bladder. The latter may involve hormone-induced alterations in luminal cell membrane structure and chemistry.

Simple Technique to Facilitate Tissue Sampling for Electron Microscopy

The need to examine certain components of a specimen with the electron microscope is frequently recognized only after study of the paraffin sections, by which time the total specimen has usually been fixed in Formalin. Such specimens are frequently large, with the result that representative samples for electron microscopy may be difficult to isolate. A simple, quick, and inexpensive method for overcoming this sampling problem is described. This technique is best employed in laboratories that routinely use a single tissue fixative suitable for both light and electron microscopy. The specimen is taken direct from the Formalin, and very thin slices are prepared by hand with a blade, stained with methylene blue, and examined in the wet state under the microscope. On identification, representative tissue is removed by micro-dissection and processed further for electron microscopy.

Convoluted secretory material in thyroid follicular epithelial tumors.

Electron microscopy may occasionally be useful, when routine histopathologic methods fail, in the typing of tumors, including those that present as metastases from occult primary sites. We describe a case in which the presence of an uncommon ultrastructural feature aided in establishing the thyroid gland as the source of a skeletal metastatic tumor.