John D. Shelburne

Fungal Peritonitis in Patients on Continuous Ambulatory Peritoneal Dialysis

Fungal peritonitis is a rare complication in patients on continuous ambulatory peritoneal dialysis. We report five recent cases and their management. The fungi isolated were Candida albicans, C. parapsilosis, Exophiala jeanselmei, Drechslera spicifera, and a Fusarium species. Chemotherapy was attempted with various regimens including oral ketoconazole, intravenous or intraperitoneal amphotericin B, and oral flucytosine. Pharmacokinetic studies were done in two patients receiving treatment with one of these drugs. Three patients were cured of their fungal infection. Three patients whose Tenckhoff catheters were left in situ died, whereas two patients whose catheters were removed survived. Our experience suggests that removal of the peritoneal catheter should be considered once the diagnosis of fungal peritonitis is established.

Localization of phosphorylated ERK/MAP kinases to mitochondria and autophagosomes in Lewy body diseases.

We previously found that sustained ERK activation contributes to toxicity elicited by the parkinsonian neurotoxin 6‐hydroxydopamine. In addition, substantia nigra neurons from patients with incidental Lewy body disease, Parkinsons disease (PD), and diffuse Lewy body dementia (DLB) display abnormal phospho‐ERK accumulations in the form of discrete cytoplasmic granules. In this study, we investigated the subcellular localization of phospho‐ERK immunoreactive granules using double label confocal microscopy and immunoelectron microscopy. A small percentage of phospho‐ERK granules colocalized with the early endosome marker Rab5, but not with cathepsin D, 20S proteasome β‐subunit, or cytochrome P450 reductase. Phospho‐ERK immunoreactivity was often associated with mitochondrial proteins (MnSOD, 60 kDa and 110 kDa mitochondrial antigens), and some vesicular‐appearing phospho‐ERK granules appeared to envelop enlarged mitochondria by confocal laser scanning microscopy. Ultrastructural immuno‐gold studies revealed phospho‐ERK labeling in mitochondria and in association with bundles of ∼10 nm fibrils. Heavily labeled mitochondria were observed within autophagosomes. As mitochondrial pathology may play a pivotal role in Parkinsons and other related neurodegenerative diseases, these studies suggest a potential interaction between dysfunctional mitochondria, autophagy, and ERK signaling pathways.

Pulmonary carcinomas with a sarcomatoid element: An immunocytochemical and ultrastructural analysis

Eight primary carcinomas of the lung with a prominent spindle-cell sarcomatoid component were studied by immunocytochemical staining and electron microscopy. The eight tumors were indistinguishable by conventional light microscopy, with the exception of one unusual neoplasm that followed multiple pathways of differentiation with elements of squamous cell carcinoma, rhabdomyosarcoma, chondrosarcoma, and an undifferentiated spindle-cell population. Reticulin fiber production by individual spindle cells and a sharp demarcation of the carcinomatous and sarcomatoid domains by light microscopy were not useful differentiating features. Three of the eight tumors exhibited keratin expression in both the carcinomatous and spindle-cell components. Both immunocytochemical and electron microscopic analyses were required to detect epithelial differentiation, as in one case keratin was identified only by immunocytochemical staining and in another only by ultrastructural examination. Epithelial differentiation was undetectable in the sarcomatoid component of five tumors, and in one case immunoreactive myoglobin was identified in spindle cells; skeletal muscle differentiation was confirmed ultrastructurally. We propose that pulmonary carcinomas exhibiting evidence of epithelial differentiation in a sarcomatoid component be termed spindle-cell carcinomas and that those biphasic tumors exhibiting mesenchymal differentiation into specific tissues, such as neoplastic bone, cartilage, or striated muscle, or lacking epithelial differentiation by light microscopy, immunocytochemistry, and electron microscopy be classified as carcinosarcomas. This distinction may ultimately be unnecessary, because these two tumors may represent different points along a morphologic and biologic continuum.

Primary brain tumours in Fischer 344 rats chronically exposed to acrylonitrile in their drinking-water

Acrylonitrile (ACN) has been tested for carcinogenicity by various routes in a number of rat strains. At relatively high levels of administration (e.g. 500 ppm in the drinking-water) there were statistically significant increases in microscopically detectable primary brain tumours, which were difficult to classify. In a further study of ACN-induced brain tumours, ACN was administered to groups of 50 male and 50 female F-344 rats from 6 wk of age at levels of 0, 100 and 500 ppm in the drinking-water. A fourth group of 300 rats (147 males, 153 females), was also given 500 ppm ACN. Neurological signs were observed in 0, 4, 16 and 29, respectively, of the rats in these four groups within 12-18 months. Among the treated animals, females died slightly earlier than males. Few controls of either sex had died by month 18, but, apart from those killed for tumour donation, a high proportion of the rats in the 500-ppm groups had died by that time. Of the 49 brain tumours found in rats exposed to 500 ppm ACN, 11 were only detectable microscopically, 28 were 1-5 mm in diameter and 10 were greater than 5 mm. Despite this variation in size, all the tumours were similar in cellular and architectural features. They were densely cellular, with occasional areas of focal necrosis, and were infiltrative at the margins. They were negative for glial fibrillary acidic protein (GFAP). Ultrastructurally, the tumour cells showed intermingling cytoplasmic processes but no glial filaments and no neurosecretory granules or specialized cell contacts. Samples of tumour tissue were successfully grown in culture, but transplantation of samples from these cultures (observed for up to 12 wk) was unsuccessful. However, a direct intracerebral transplantation from a large tumour was successful.

Pseudo-Gaucher Cells in Multiple Myeloma

A bone biopsy specimen from a patient with multiple myeloma showed numerous Gaucher-like cells scattered throughout a homogeneous background of plasma cells. Further studies using histochemical stains, immunofluorescence, and light and electron microscopy were carried out to further define these cells. Light microscopy of Wright-stained and hematoxylin and eosin-stained marrow preparations showed large, round cells with fibrillar appearing cytoplasm and eccentric, pyknotic nuclei. These cells were periodic acid-Schiff positive, resistant to diastase digestion. Electron microscopy demonstrated plasma cells containing crystals in membrane-bound vesicles. Also, large macrophages among these plasma cells contained similar crystals surrounded by a single limiting membrane. Immunofluorescence staining of thin sections of marrow with fluorescein-labelled specific antiserums showed fluorescence of these large cells. Strong immunofluorescence was seen with polyvalent kappa and gamma antiserums but not with anti-albumin or serums with anti-lambda, mu or alpha specificity. It appears that these large cells have the light microscopic and histochemical characteristics of true Gaucher cells but, when studied with immunofluorescence and electron microscopy, it appears that the pseudo-Gaucher cells of multiple myeloma are bone marrow macrophages engorged with immunoglobulin.

Sequential Changes in Lung Morphology during the Repair of Acute Oxygen-induced Lung Injury in Adult Rats

We studied changes in lung ultrastructure and collagen content during the repair of acute lung injury in adult rats exposed to 100% O2 for 60 h and recovering in ambient air. In the interstitium, during the first 3 days of repair, the number of neutrophils decreased 16-fold, and monocytes and lymphocytes increased to 7-fold and 4-fold the respective control values. Myofibroblasts increased about 5-fold and the volume of the interstitial matrix remained high. By 7 days, the differential count of inflammatory cells was normal although the number of total interstitial cells and myofibroblasts decreased more slowly. In the capillary endothelium, after 3 days of repair, the cells were hypertrophied and had organelle-rich cytoplasm, and total cell number had increased back to control values; endothelial cell number increased an additional 63% between 3 and 7 days of repair. In the epithelium, type 2 cells increased 150% during the first 3 days of repair before decreasing; type 1 cell number did not change. After 28 days of repair, the lungs appeared qualitatively almost normal; however, interstitial cell number and collagen content were still increased. We conclude that the repair of oxygen-induced lung injury involves a complex pattern of morphologic changes that has important similarities to those occurring during repair on other tissues such as the skin.

Scanning Electron Microscopic Study of the Airways in Normal Children and in Patients with Cystic Fibrosis and Other Lung Diseases

Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were used to examine pulmonary tissue from 9 patients with cystic fibrosis (CF), 12 patients with diseases other than CF, and from two surgically resected specimens with no known airways disease. A region of the human airways, the transition zone, was observed between the end of the terminal bronchiole and the type II alveolar cell lining of the respiratory bronchioles. This region was lined predominantly by nonciliated bronchiolar (NCB) cells. Patients with CF exhibited indistinct transition zones, epidermoid metaplasia, large dilated bronchial glands, copious surface mucus, alveolar destruction, and unusual microvilli; no single lesion specific for cystic fibrosis was identified.

Principles and instrumentation

Electron microscopy is analytical to some extent. Analytical electron microscopy (AEM) can be defined as the observation of the interaction of electrons with matter at a resolution smaller than that which could be seen with the naked eye. This obviously includes all images in general; however, the term “microprobe analysis” has evolved to make it essentially a form of microchemistry in particular. The wavelength of X-rays can be measured using a wavelength dispersive spectrometer, or the characteristic energies can be measured by means of an energy dispersive spectrometer. Each instrumental configuration has its own advantages and limitations, and the choice of instrumentation depends not only on user preference but also on the particular task at hand. For example, analytical transmission electron microscopy can allow the user to obtain crystallographic information about the sample by means of selected area electron diffraction, whereas analytical scanning electron microscopy permits the elemental analysis of bulk samples and, more recently, the potential to determine the microcrystallographic characteristics of mineral specimens. This approach is particularly useful for the analysis of clinical specimens when combined with backscattered electron imaging, which enhances the ability to detect inorganic particulates of relatively high atomic number in an organic matrix of low atomic number.

Lymph-Node Bacilliform Bodies Resembling Those of Whipple's Disease in a Patient without Intestinal Involvement

A 38-year-old man developed symptoms of arthalgias and arthritis, lymphadenopathy, and weight loss. An axillary lymph-node biopsy was done in the diagnostic study; a periodic acid Schiff stain, done for evidence of fungal infection, showed periodic acid Schiff reagent-positive macrophages. Electron microscopy showed the typical morphologic features of the bacilliform bodies associated with Whipples disease to be present in the macrophages of the lymph node. The patient had no intestinal symptoms. The absorption of a variety of substrates was found to be normal. Nine intestinal biopsies showed no organisms similar to those found in his lymph node. On tetracycline therapy, he symptomatically improved. The findings raise the question of the route of infection in Whipples disease and point up the usefulness of periodic acid Schiff staining of lymph-node biopsies.

Primary malignant fibrous histiocytoma of the lung. A clinicopathologic and ultrastructural study of five cases

Primary sarcomas of the lung are rare malignant neoplasms which have usually been classified as fibrosarcomas or as leiomyosarcomas. Only five cases of primary malignant fibrous histiocytoma (MFH) of the lung have previously been reported in the literature. The authors reviewed 10 cases of primary pulmonary sarcoma of the lung seen at their institution during the last 12 years, and five of these cases met the morphologic criteria for the diagnosis of MFH. The morphology in these cases is identical to MFH of other body locations, and shows a combination of fibroblast‐like and histiocyte‐like cells at both the light and electron microscopic level. By electron microscopic examination there was no evidence for anaplastic carcinoma, rhabdomyosarcoma, or leiomyosarcoma. Of the three patients with adequate follow‐up, one patient is alive without evidence of disease at 10 years, one died at 5 years without evidence of recurrent sarcoma, and one died at 7 months with liver metastasis. Two other patients are alive without recurrence at 8 months and 1 year, respectively, following surgery. Because MFH is primarily a tumor of the soft tissues of the extremities, patients with MFH of the lung must be carefully evaluated to rule out a metastatic origin. The reported prognosis in patients with primary MFH of the lung is poor, but early surgical resection does offer the possibility of a cure. Cancer 53:1124‐1130, 1984.