A technique for the isolation of submucosal gland cells from cat trachea

We have developed a procedure to isolate submucosal gland cells from cat trachea. The excised trachea was stripped of surface epithelium by stroking the luminal surface with a nylon brush. The remaining submucosa was scraped free from underlying cartilage and minced into small fragments. To disperse glandular cells from these fragments, we subjected the minced tissue to both enzymatic (collagenase and elastase) and mechanical treatment. In 23 preparations of cells we yielded an average (+/- SE) of 8.4 +/- 0.9 (X 10(6] cells. In eight cell preparations 95 +/- 1% of the cells stained with periodic acid-Schiff stain, suggesting that the cells are of glandular origin. We used the following criteria to assess cell viability. The dye trypan blue was excluded by 92 +/- 1% of the cells (n = 23). Under the electron microscope, cellular membranes and organelles appeared normal. The isolated cells consumed oxygen at an average rate of 1.34 +/- 0.05 microliters O2 X h -1 X (10(6) cell) -1, (n = 65). Oxygen consumption was constant for at least 4 h after cell isolation, was inhibited 21% by 10(-4) M ouabain, and was subsequently stimulated to 135% above basal levels by 4 X 10(-5) M dinitrophenol.

Light-microscopic immunocytochemical localization of fibronectin in the developing rat lung

The development of the rat lung is a process of continuing morphological change. Indications from work in other mammalian systems suggest that fibronectin may be important in the control of this process. The present study has examined embryonic, neonatal, and adult lung tissue of the rat by means of the peroxidase-antiperoxidase (PAP) technique to demonstrate fibronectin at the light-microscopic level. Positive reaction was observed with anti-fibronectin serum in all stages examined. Control sections treated with pre-immune serum or no primary serum gave negative results in each case. Fibronectin in adult tissue was localized to the alveolar surface and alveolar basal lamina. Neonatal tissue showed fibronectin on pulmonary tubule walls and in basal lamina while embryonic tissue revealed localization of the protein in the basal lamina and in association with small groups of cells at the base of septal buds. These findings suggest a role for fibronectin in the control of rat lung development. The results are discussed in terms of the known functions of fibronectin as a preliminary matrix for the subsequent deposition of collagenous connective tissue, as a cellular adhesion protein, and as surface-bound material for cellular migration.

Sequential effects of irradiation on the pulmonary surfactant system

This study examines the effect of irradiation on lung surfactant synthesis and secretion in mice. Animals were irradiated with 650, 1300, or 1950 rad and morphological and biochemical indices of surfactant system function were followed for 18 weeks. No changes were seen at 650 rad; the results at 1300 and 1950 rad were virtually identical. Increased amounts of alveolar surfactant phospholipid were measureable by 24-hours. This persisted for four weeks and returned to normal by 18 weeks. Tissue surfactant phospholipid was initially reduced, returned to normal by four weeks and was increased at 18 weeks. At 18 weeks there was increased incorporation of surfactant precursor and increased production of alveolar surfactant. These biochemical changes were reflected in morphologic alterations showing release of lamellar body contents into alveoli in the first week and an increase in lamellar bodies in type II pneumocytes by 18 weeks. Elevated tissue protein levels and morphologic evidence of increased collagen formation were also found at 18 weeks. These findings indicate effects of irradiation on the pulmonary surfactant system and have important implications for the pathogenesis and potential therapy of radiation pneumonitis.

Morphologic changes reflecting early and late effects of irradiation of the distal lung of the mouse: a review

In radiation of the thorax, the lung has been shown to be a major dose-limiting organ. The early and late responses of the lung to radiation has been reviewed, with primary emphasis on the following cell types: type II pneumocyte, type I pneumocyte, pulmonary endothelial cell and macrophage. The earliest observable and quantifiable cellular response to radiation is exhibited by the type II pneumocytes as a decrease in lamellar bodies and a corresponding increase in surfactant content of the alveolar lavage. By 18-63 weeks following exposure, several type II cells, restored in their lamellar body population, undergo degeneration and sloughing into alveolar spaces. Type I pneumocytes generally exhibit little change, although some investigators describe alveolar denudation due to degenerating type I cells. Macrophages decrease in numbers following irradiation, returning to normal populations by 4 weeks. These changes correspond closely to the changes in alveolar lavage phospholipid phosphorus. Descriptions of radiation-induced damage to endothelial cells are variable. However, blebbing and vacuolation appear to be late developing responses, although altered permeability may be earlier in its expression. Radiation pneumonitis and fibrosis are the two major clinical and experimental responses of the lung to radiation following exposures of greater than 12 Gy. The former appears to involve type II cells, macrophages and pulmonary endothelial cells, and for the latter macrophages, fibroblasts, type II pneumocytes and the pulmonary endothelial cells are involved. The two events are not interdependent, and may not necessarily be interrelated.

Acrylamide neurotoxicity in the mouse: a behavioral, electrophysiological and morphological study

The development of acrylamide induced neurotoxicity was followed for 3 weeks in the mouse by behavioral testing, determination of conduction velocities and electron microscopic examination of peripheral nerves. Neurotoxic signs began to appear during the second week of treatment. A condition of severe intoxication developed within 21 days. Behavioral assessment for neurological deficits proved to be more sensitive than sensory or motor conduction velocity determinations either in isolated preparations or in situ. In general, such electrophysiological determinations did not result in reproducible, statistically significant, differences from control animals until the third week of acrylamide administration. However, there was a suggestion that temperature reduction may provide a provocative change to increase the sensitivity of such electrophysiological measurements. Electron microscopic examination of the nerves of severely poisoned animals revealed myelin corrugation and delamination to be the most consistent damage. Acrylamide appeared to produce a nonselective attack since degenerating fibers were found intermingled with almost normal fibers of approximately the same diameter. In general, the production of neurotoxicity in the mouse closely resembled that seen in the rat but some differences were noted.

Fine structural study of postcastrational adrenocortical carcinomas in female CE-mice

Postcastrational adrenocortical carcinomas in the CE/Ki inbred strains of mice and the adrenals of noncastrated CE/Ki mice were studied using light and electron microscopic techniques. Most of the tumors appeared as large nodules of cells separated by septae comprised of collagen and blood sinusoids. The majority of tumor cells (Type 1) showed few or no lipid droplets (sudanophobic), polymorphic hyperchromatic nuclei, lack of SER, abundant RER and free ribosomes, prominent Golgi complexes, and few mitochondria with scant internal membranes. Clusters of Type 1 cells were surrounded by a basal lamina. In contrast, Type 2 cells revealed abundant and dilated tubules of SER, large number of lipid droplets and mitochondria with tubulovesicular cristae. These results suggest that Type 2 cells were probably active in steroid hormone synthesis and secretion while Type 1 cells were highly anaplastic and apparently non-steroid-secreting cells.

Phenobarbital-induced alterations of the rat adrenal cortex

To determine the morpholic changes in adrenocortices induced by chronic phenobarbital therapy, the male rats were orally administered the drug daily for varying periods up to three months. Fine structural changes attributable to the drug included mitochrondrial pleomorphism and cavitation, loss of cholesterol ester clefts, reorganization of intracellular lipid, hypertrophy of the agranular endoplasmic reticulum and a juxtapositioning of the agranular endoplasmic reticulum, mitochondria and lipid droplets--all suggestive of an actively secreting cortex. The digitonin-glutaraldehyde reaction suggested an active translocation of free cholesterol from lipid droplets to the mitochondria and agranular endoplasmic reticulum following phenobarbital treatment. Phenobarbital appears to stimulate corticosteroidogenesis due in large part to enhanced hepatic corticoid metabolizing enzymes.

Fine structural and biochemical effects of aminoglutethimide and o,p'-DDD on rat adrenocortical carcinoma 494 and adrenals

Rats bearing adrenocortical carcinoma 494 were injected daily for 7, 14, or 21 days with aminoglutethimide (AG) or o,p'-DDD. Reversibility of these steroidogenic inhibitors was determined by injecting other animals for either 14 or 21 days and sacrificing them 14 days later. While the drugs had little effect on body or tumor growth, plasma corticosterone levels were reduced a maximum of 88% in normal and 95% in tumor-bearing rats during AG chemotherapy. These levels were unaltered in normal rats by o,p'-DDD and reduced a maximum of 64% in tumor-bearing animals. Relative adrenal weights generally increased during chemotherapy and then returned to control levels. These changes were mainly due to alterations in the lipid and mitochondrial volume fractions. Lipid increased with both drugs while mitochondria increased with o,p'-DDD and decreased with AG. Cholesterol ester levels paralleled the lipid stereology more closely with AG than o,p'-DDD. With both drugs the most notable changes in tumor fine structure was a decrease in mitochondrial internal membranous vesicles and matrical density. Adrenal mitochondria had the irregular, elongated forms characteristic of tumor-bearing animals and were vacuolated (AG) or had internal rings (o,p'-DDD). The large lipid droplets observed during chemotherapy with both drugs were replaced by numerous small droplets in recovery periods.

Effect of acute and chronic misonidazole administration on peripheral-nerve electrophysiology in mice

I.p. administration at several dose levels over periods of up to 12 weeks, or continuous i.v. infusion of high doses of misonidazole (MISO) for 15 h, produced no significant change in peripheral nerve conduction velocity (NCV) and did not prevent the normal increase in NCV as the animals matured from 12 to 24 weeks of age. Peripheral NCV (sural nerve) was reduced in both MISO-treated and control mice with hind-limb tumour implants, presumably owing to physical pressure due to tumour growth. In addition, neither the medial nerves nor the tibial nerve in the normal limbs of the tumour-implanted, drug-treated animals showed any change. Consequently our earlier and present studies do not confirm the recent reports of changes in NCV following either acute or chronic MISO administration to mice.

Diazepam receptor: specific nuclear binding of [3H]flunitrazepam

Autoradiographic localization of [3H]flunitrazepam in nuclei of the rat cerebral cortex was further confirmed by biochemical analysis of specific nuclear binding. Highly purified rat cerebral cortex nuclei were shown to bind [3H]flunitrazepam specifically. The Kd(app) for nuclear binding was 28 nM for the nuclei compared with a Kd(app) of 1.1 nM for binding of [3H] flunitrazepam to synaptosomal membrane fractions of the same tissue. Inhibition of the nuclear binding with inosine and hypoxanthine was greater than inhibition of the synaptic membrane fractions. These results lead to to conclude that specific binding may occur at both the synaptic membrane and the nuclear levels and that different endogenous ligands may compete at each site for binding. Furthermore, the possibility exists for translocation and alteration of the bound ligand complex from membrane site to nuclear site.

Morphological and functional characteristics of cells infiltrating and destroying tumor multicellular spheroids in vivo

EMT6 mammary sarcoma cells were grown in vitro as multicellular spheroids to model for the heterogeneity of microenvironments and structural changes which develop in many tumors, including micrometastases. Spheroids of 700-900 micron diameter were implanted into and recovered at different times from the peritoneal cavities of sensitized or nonsensitized allogeneic and syngeneic mice. The colony forming efficiency of spheroid tumor cells recovered at 24 and 48 h from sensitized allogeneic mice was markedly decreased as compared with those from nonsensitized allogeneic or syngeneic animals. These recovered spheroids were extensively infiltrated by both lymphocytes and macrophages, which ultrastructurally had very close membrane associations with tumor cells. Host cells recovered from spheroids exhibited cytotoxic activity in an in vitro 51Cr release assay. Thus, multicellular spheroids in vivo provide a unique experimental model to study the functional capacity of host cells within a spheroical tumor. Although lacking the stroma and the vasculature of in vivo solid tumors, this model does have many similarities to in vivo tumors and is thus suitable for studying the tumor cell-host cell interactions within the tumor microenvironment. In addition, the system offers the potential for quantitative study of the effects of treatment modalities on tumor cell-host cell interactions.

Biochemical, morphologic and physiologic changes in the adrenal glands of rats chronically treated with phenobarbital

Biochemical and ultrastructural changes in the adrenal glands of rats were observed after long-term phenobarbital treatment. At the fine structural level, the parenchymal cells of the phenobarbital-treated rats resembled cortical cells that had been stimulated by adrenocorticotropin. A significant finding was the presence of very large hollow mitochondria characterized by loss of vesicles and cristae with retention of the double outer membrane. Arylesterase (EC 3.1.1.2) activity, the marker used for rough endoplasmic reticulum, was significantly diminished. Since rough endoplasmic reticulum is present primarily in the adrenal medulla and not the cortex, the relative decrease in arylesterase activity is consistent with the morphologic adrenal cortical hyperplasia. Trypsin-like (EC 3.4.4.4) enzyme activity was increased. The plasma corticosterone response to adrenocorticotropin injection was not significantly different in treated and control rats. The similarity of the observed mitochondrial changes to the reported mitochondrial cavitation in the adrenal glands of rats treated with aminoglutethimide is discussed.

Changes in the adrenal cortex of the rat after chronic administration of the steroidogenic inhibitor U-8113

In concert with studies of the effects of various pharmacologic inhibitors of corticosteroidogenesis on adrenocortical morphology, U-8113, an analog of amphenone B, was administered daily to Sprague-Dawley rats for 7, 14, 21 or 30 day. The primary morphological responses involved increases in adrenal weight, width of zona fasciculata, width of zona reticularis, intracellular lipids, mitochondrial size, mitochondrial vacuolation and crystalline-like inclusions, small coated vesicles, lysosomes, autophagic vacuoles and cholesterol ester clefts. In particular, the increases in lysosomes, coated vesicles and autophagic vacuoles containing morphologically altered mitochondria were considered reflective of mechanisms designed to maintain cellular integrity amidst functional impairment. Lipid analysis revealed marked increases in cholesterol esters and phospholipids, supportive of morphological observations. When permitted a 14 day recovery period following either 14 or 30 days of inhibitor therapy, most fine structural alterations and lipid derangements were diminished, and the cells approximated normal parameters.

Fine structural studies of radiation-resistant human squamous cell carcinomas

Squamous cell carcinomas of the oral cavity are relatively common lesions, and often can be controlled by radiation therapy. Recently, a series of these tumors has been encountered which did not respond positively to irradiation, necessitating subsequent extensive surgery. This report describes some fine structural changes which were observed in squamous cell carcinomas following exposure to x-irradiation. In addition to the common, keratin-forming differentiated cell, others which were observed were secretory-like, undifferentiated and phagocytic cells. Undifferentiated tumor cells occasionally became incorporated, at least temporarily, as a component of the blood vessel wall, perhaps reflecting metastatic potentiality. It is proposed that irradiation may either increase potential avenues of tumor cell differentiation or inactivate inhibitors thereof.

Rat adrenocortical carcinoma 494: an integrated structural, stereological, and biochemical analysis

Snell adrenocortical tumor 494 was implanted into male Sprague-Dawley rats and recovered 7, 14, 21, 28 or 35 days following initial detection by palpation (7-10 days following transplantation). Electron microscopic, stereological and biochemical analyses of the tumor were compared to adrenals of normal animals to serve as a baseline for further studies of the effects of chemotherapeutic agents on tumor cells. Tumor cells possessed oval or elongated mitochondrial profiles with tubular cristae, one or two very large (greater than 5 micrometer) lipid droplets, abundant ribosomes and coated vesicles, and sparse rough and smooth endoplasmic reticulum. Stereologic evaluation revealed that tumor lipid volume was 41% and mitochondrial volume 29% that of the normal adrenal controls. Tumor nuclei were 2.5 times larger than adrenocortical nuclei while cellular volumes were similar. On a net weight basis, tumor cholesterol was 55%, cholesterol ester 2.2%, and lipid phosphate 25% of respective mean values for normal adrenal glands. The tumor cholesterol: cholesterol ester ratio progressively decreased with time but remained 18-fold greater than the normal adrenal. Plasma corticosterone levels in tumor-bearing rats were elevated 3-fold by 14 days and initial detection. The adrenals of the tumor-bearing host exhibited marked involution, the extent of which was directly related to tumor size.

Fine structural studies of a human thyroid adenoma, with special reference to psammoma bodies

The fine structural morphologic features of a microfollicular thyroid adenoma from a 28 year old female were examined. Although the patient had been laking exogenous thyroxine therapy for 14 months, the morphology of the adenoma was characterized by numerous small to medium sized follicles composed of metabolically active, well differentiated columnar cells with numerous colloid droplets, dilated granular endoplasmic reticulum, large numbers of coated vesicles and lysosomes, large colloid containing "lakes," microtubules, microfilaments, and prominent apical microvillous projections. Of special inetrest were small spherical psammomatous calcospherites ecountered in histiocytes and the interstitium. Also noteworthy were ropelike configurations observed in most of the follicular lumina. Structural-functional correlations and potential origins of psammoma bodies and calcospherites are discussed.

A modified grid apparatus for stereological analysis of light and electron micrographs

A simplified and inexpensive grid apparatus for use with the differential point counting technique of stereological analysis of cellular and organellar volumes is described.

Effect of corticotropin, steroidogenic inhibitors and hypophysectomy on the nuclear volumes of fasciculata cells in the rat adrenal cortex

The purpose of this investigation was to measure quantitatively nuclear volumes in outer fasciculata cells in adrenal glands of rats subjected to chronic stimulation of steroidogenesis by ACTH, or to chronic inhibition of functional activity by hypophysectomy or by injection of the steroidogenic inhibitos, U-8113 (p-aminophenyl butanone) and SU-4885 (metopirone). Nuclear volumes, after a recovery period from those effects, were also measured. Chronic daily administrations of ACTH for 7, 14, and 30 days led to a progressive, statistically significant increase in nuclear volumes of fasciculata cells. These changes were found to have been reversed 14 days after discontinuation of hormone treatment. Hypophysectomy resulted in a significant decrease in nuclear volumes. The steroidogenic inhibitors SU-4885 and U-8113 had a biphasic effect on the nuclear volumes with an early decrease and subsequent increase to normal values. Since a decrease in nuclear volumes in the adrenal glands of inhibitor-treated subjects occurred in the presence of cellular hypertrophy and a significant increase in adrenal weights, it is concluded that changes in nuclear volumes can be positively correlated with the secretory activity of the cell rather than with the sizes of cells or glands.