Nuclear ultrastructure in carcinoma, adenoma, Peutz-Jeghers polyp and dysplasia of the large bowel: a morphometric analysis

The nuclear areas, perimeter, diameter and form factor, and nucleolar area and diameter of about 50 cells in each in 38 colonic epithelial lesions including normal epithelium (6), Peutz-Jeghers polyp (2), adenoma (11), dysplasia (6) and carcinoma (13) were measured at the electron microscopic level by using an image analyzer. The area of nucleoli was larger in dysplasia and carcinoma than the normal (statistically significant). The area of nuclei was larger in carcinoma than the normal. The form factor was also largest in the nuclei of carcinoma, indicating that these cells had the most spherical shape. These results suggest the possibility of quantitative diagnosis of epithelial lesions by measuring the area and perimeter of some 50 nuclei and nucleoli.

Electron microscopy of polyps of the colon. I. Comparative study of the epithelial cells of adenomatous and adenopapillary polyps

By comparing the electron-microscopic pictures of adenomatous and adenopapillary polyps, the ultrastructural characteristics of premalignant epithelial dysplasia were studied. In highly differentiated adenomatous polyps, the ratio and the electron-microscopic appearance of absorptive and goblet cells did not differ from the epithelial cells of the normal mucosa of the colon. In the dysplastic regions of adenopapillary polyps, the intensive proliferation in several layers of undifferentiated epithelial cells, and the maturation disorder of absorptive and goblet cells, were observed. Severe changes occurred on the cell membrane as well as atypical vacuoles and dense bodies in the apical regions of the cell membrane. Several inclusion bodies of Leuchtenberger were observed, these being considered an important characteristic of malignant transformation.

Electron microscopy of polyps of the colon. II. Inclusion bodies of Leuchtenberger

The electron-microscopic characteristics of the LEUCHTENBERGER'S inclusion bodies were studied in adenomatous, papillary and adeno-papillary polyps of the colon. According to them, formation of intracellular inclusions is due to focal cytoplasmic degradation, and that of intercellular inclusions to the herniation of the cytoplasmic part of epithelial cells. The formation of inclusions is believed to be connected with the low stage of development of the plasma membrane of rapidly proliferating undifferentiated colonic epithelial cells. During malignant transformation of polyps, the frequently occurring inclusions are considered an important morphological sign.

Genesis of 1,2-dimethylhydrazine-induced colon cancer. A light and electron microscopic study

Rats treated with 1,2-dimethylhydrazine (DMH) exhibited colonic mucosal dysplastic foci prior to the development of tumors. Ultrastructurally, these, as well as the cancers that subsequently developed, were characterized by alterations in plasma membranes and an increase in cytoplasmic ribosomal particles, principally in stem cells and their absorptive derivatives. Rare Kulchitsky cells appeared preserved, but the mucin-producing or goblet-cell elements were compressed and atrophic. In addition, nuclear aberrations were more pronounced in the cancer than in the dysplastic foci. The principal ultrastructural difference between the so-called well-differentiated and mucinous forms of DMH-induced cancers was the presence of frequent intracytoplasmic lumens in the mucinous form. Such structures represented the analogues of signet ring cells observed by light microscopy. This experimental model of human colonic cancer shows that the mucosal stem-cell and dysplastic lesions represent their cytogenetic and histogenetic progenitors.

Electron microscopic study of carcinoma of the colon

During electron microscopic studies of 24 carcinomas of the colon the authors compared the ultrastructural characteristics of tumorous epithelial cells of various degrees of differentiation. Beside the epithelial elements, the myofibroblast reaction, considered to be a local immune reaction due to invasive tumour cells, observable in the stroma of tumours was also treated in detail. It was observed that myofibroblasts develop from the fibroblasts of the matrix of colonic mucosa.

Ultrastructural markers of colonic adenocarcinoma

A mixed population of 96 adenocarcinomas was examined by electron microscopy to establish the presence of organ specific features. This resulted in the identification of fine structural characteristics, occurring consistently in colorectal adenocarcinomas but not in other epithelial tumors. The colorectal "ultrastructural profile" consists of microvilli with dense cores of microfilaments extending as long rootlets into a clear zone of apical cytoplasm, apical electron dense bodies, and abundant glycocalyceal bodies. Of these features, the long rootlets constitute the best morphologic marker for large intestinal type adenocarcinoma. Using these characteristics in another series of 58 adenocarcinomas studied in a double-blind manner, it was possible to distinguish colorectal adenocarcinomas from other carcinomas on ultrastructural grounds alone.

A study of some mitochondrial and peroxisomal enzymes in human colonic adenocarcinoma

Three mitochondrial enzymes, cytochrome oxidase, succinate dehydrogenase, and monoamine oxidase, and two peroxisomal enzymes, catalase and urate oxidase, were measured spectrophotometrically in the postnuclear supernatant prepared from homogenates of normal mucosa and carcinoma of the human colon. The specific activities, in both normal mucosa and carcinoma, varied from patient to patient. However, the difference in these activities between normal mucosa and carcinoma was consistent when patients were compared. The activities of cytochrome oxidase, succinate dehydrogenase, monoamine oxidase, and catalase were greater in normal mucosa than in carcinoma. In contrast, urate oxidase activity increased in carcinoma as compared with normal mucosa. Furthermore, cytochrome oxidase and succinate dehydrogenase decreased proportionally in carcinoma, supporting the concept that the mitochondrial respiration in normal tissue and carcinoma is quantitatively but no qualitatively changed. However, the decrease in monoamine oxidase activity in carcinoma was greater than that observed with other mitochondrial enzyme activities and was irregular. This suggests that a qualitative mitochondrial change may occur in carcinoma. In particular, the ratio between outer membrane enzyme activity and respiratory enzyme activity may be altered.

Grades of atypia in tubular and villous adenomas of the human colon. An electron microscopic study

Of a total of 544 tubular, villous and tubulo-villous adenomas of the human colon which were investigated by light microscopy, six tubular and six villous adenomas were examined under the electron microscope. It was shown that the two types of adenoma differ in their tissue architecture, but not in their cytological appearance. Different grades of epithelial atypia occur in both types of adenoma. These are designated as grades I to III, correspond to mild, moderate and severe atypia respectively. Whereas adenoma cells with atypia grade I clearly show a cytological relationship with crypt epithelia of the normal colonic mucosa under the electron microscope, adenoma cells with atypia grade III have largely lost the differentiation characteristics of the parent cells and there is no longer intracytoplasmic organization. In the cytoplasm of adenoma cells with atypia grade II, glycogen storage is found as a special feature which does not occur in normal colonic epithelium. A similar finding has been described in the course of malignant transformation of the liver and kidney and thus can be regarded as a further indication of the precancerous nature of the adenomas.

Mucous and argentaffin cells in colonic adenocarcinomas of tamarins and rats

Primary and metastatic neoplasms of four naturally occurring colonic adenocarcinomas in the cotton-topped tamarin, Saguinus oedipus oedipus, and four chemically induced rat colonic adenocarcinomas were examined with light and electron microscopy. In each case, we observed mixtures of mucous and argentaffin cells in metastatic sites, proving that endocrine cells are an integral part of these tumors. The occurrence of mixed cell populations in metastases in both species suggests, but does not prove, that colonic tumor cells have the capacity for multi-directional differentiation and that neoplastic mucous and argentaffin cells in the colon have a common origin. We also observed mitotic figures in neoplastic argentaffin cells, confirming the observations of others that these cells can label with tritiated thymidine and divide.

Tight junctions in epithelial cells of human fetal hindgut, normal colon, and colon adenocarcinoma

The structural patterns of tight junctions in normal human colon mucosa, colon adenocarcinomas, and fetal colon were studied and compared by the freeze-fracturing technique. The zonula occludens of the normal colon cells at the upper, more differentiated part of the crypts of Lieberkühn appeared as continuous belts made of about eight parallel strands. At the less differentiated bases of the crypts, the zonula occludens was less regular and contained fewer, mostly beaded strands. In the colons of 10-week fetuses, early stages of tight junction assembly were observed. At the same time, vesicles bearing remnants of tight junction elements were observed within the cytoplasm. This finding suggested that during the early development and organization of the fetal gut, mechanisms of assembly and disassembly of tight junctions are operating concomitantly. In well-differentiated adenocarcinomas, the cells in the luminal region retained their polarity and had seven or eight parallel junctional elements. In infiltrating cells, however, tight junctions appeared as fascia occludens and resembled the junctional organization of 10-week fetuses.

[Electron microscopic study of villous adenoma of the colon]

Characteristic patterns of the villous adenoma of colon have been studied by electron microscope in 12 cases. In accordance with the data of other investigators it was revealed that dominating cells of the villous adenoma were undifferentiated epithelial cells which normally occurred in Liberkühn crypts. Immaturity of cells, alteration of nuclei and pathologic changes of the cell-membrane seem to indicate malignant transformation. It is supposed, the Leuchtenberger's inclusion bodies develop as a result of strangulation of cytoplasmic processes. In tumours inducing electrolyte loss atypical cells showing evidence of mucus secretion have been observed, nevertheless mucus secreted by these cells differed from that of goblet cells of the normal colon epithelium. Author believes, that atypical cells secrete mucus of abnormal composition and this fact may lie on the basis of electrolyte losing syndrome.

Stromal reaction to neoplasia: colonic carcinomas

The stroma and stromal reaction in the normal colon and in 14 different colonic tumors were studied by electron microscopy. Elastosis is a significant part of the stromal reaction to colonic adenocarcinomas and rectal squamous cell carcinomas. Two carcinoid tumors elicited no significant elastosis. In some of the adenocarcinomas, small muscular arteries close to neoplastic tissue developed massive elastosis of the media. This may indicate that the elastosis is due to stimulation of nonneoplastic stromal cells by some unknown neoplastic factor or factors.

Electron-microscopic study of the villous adenoma of the colon

The author studied the electron-microscopic peculiarities of villous adenoma as illustrated by 12 cases. She found that the dominant cells of villous adenoma are undifferentiated epithelial cells. Electron-microscopic signs of malignant transformation were revealed by nuclear changes, by the changes in the cytoplasmic membrane and by the immaturity of cells. Leuchtenberger's inclusion bodies are assumed to develop by herniation of cytoplasmic processes of immature tumour cells. In one tumour associated with electrolyte loss, atypical cells were observed with an electronmicroscopic picture indicative of an intense secretory activity. However, the secretion drops differed from the normal mucus drops of the mature goblet cells of the colonic mucosa. The author believes it to be possible that the tumour cells of atypical morphological appearance secrete mucus of abnormal composition which could be responsible for the syndrome of electrolyte loss.

Primary malignant fibrous histiocytoma of the intestine: intussusception of a rare neoplasm

Malignant fibrous histiocytoma, a tumor of mesenchymal tissue, is being reported with increased frequency. However, no cases of primary tumors involving the gastrointestinal tract have yet been described. This report documents a case in which the patient clinically manifested a colonic obstruction associated with intussusception. Following radical resection of the mass, close re-evaluation after one year has shown no evidence of tumor recurrence.

Neoplastic human colon cells in studies on the translocation of dimeric IgA

The translocation of dimeric IgA across epithelial cells was studied by immunoelectron microscopy in an in vitro system with cultured neoplastic human colon cells (HT-29). Ultrastructurally, the cells were found to be well-polarized epithelial cells connected by intercellular junctions. Secretory component (SC) was localized to the basolateral plasma membranes. Dimeric human IgA, when reacted with the cells at 0 C, bound selectively to SC. When incubated at 37 C, the bound dimeric IgA was internalized by pinocytosis and transported apically through the cytoplasm in vesicles. The vesicles were opened to the lumen at the apical surfaces or discharged into the lumen. We conclude that the translocation of dimeric IgA across intestinal epithelial cells has been defined at the ultrastructural level in cultured neoplastic colon cells in vitro.

Scanning electron microscopy of interaction of peripheral blood lymphocytes from colonic cancer patients with human colonic cancer-derived cells; P-4788

Peripheral blood lymphocytes and the various lymphocyte fractions from patients with cancer of the colon were cultivated with target cells (P-4788) derived from the colon cancer. Changes in the surface ultrastructure during tumor cell destruction were studied by scanning electron microscopy (SEM). P-4788 cells adhering to the coverslip showed various surface activity. The surfaces of some cells were relatively flat; others were smooth or had fine granules. Still other cells were villous, round or had marked blebs. When host lymphocytes were added to the target cells, adhesion of the two cell groups began by many fine projections. After incubation for 6 h, some lymphocytes had adhered to the target cells. Many lymphocytes had adhered to the target tumor cells by 24--48 h incubation. Ultimately the tumor cells became swollen and disrupted. Most lymphocytes adherent to the target cells had few microvilli. Lymphocytes after elimination of phagocytes by carbonyl iron treatment also adhered readily. Some target cells showed adhesion with lymphocytes passed through nylon-wool columns, although the number of lymphocytes adhering was fewer than in the case of lymphocytes not passed through nylon-wool columns. T cells were collected from lymphocytes that form rosettes with SRBC by isolation with NH4Cl. They had markedly elongated microvilli which in places were sparsely scattered and tended to be localized on the side, a finding which suggests loss of cell activity by the time of SEM. Only a few T cells adhered to target cells and they seemed to be T cells without activity. It was thought that there are cytotoxic cells among T cells and that the co-existence of T cells, non-T cells and monocytes caused target cell destruction.

Paneth cell-rich papillary adenocarcinoma and a mucoid adenocarcinoma occurring synchronously in colon: a light and electron microscopic study

A 71-year-old man who presented with iron deficiency anaemia and weight loss was found to have two colonic tumours: a mucoid adenocarcinoma at the splenic flexure and a papillary adenocarcinoma rich in Paneth cells in the ascending colon. The light and ultrastructural features of the neoplastic cells are described, and the significant of the presence of neoplastic Paneth cells is discussed.

Translocation of dimeric IgA through neoplastic colon cells in vitro

We studied the translocation of dimeric IgA across epithelium, using neoplastic human colon cells in culture as a source of epithelial cells, and immunoelectronmicroscopy with peroxidase-labeled antigens and antibodies. The cells had some of the ultrastructural characteristics of normal, mature epithelial cells, i.e., polarity, desmosomal junctions, and secretory component on their basal and lateral plasma membranes. Horseradish peroxidase-labeled dimeric IgA, exposed to the cells at 0 degrees C, bound selectively to secretory component on the cell surfaces. At 37 degrees C, the bound dimeric IgA was taken into the cells by endocytosis and transported apically through the cytoplasm in vesicles. After 30 min, IgA was discharged across the apical surface. Neither colchicine (10(-4) M) nor cytochalasin B (10(-5) M) interfered with binding or endocytosis of dimeric IgA, but colchicine inhibited intracellular transport of the IgA-containing vesicles. These experiments demonstrated that dimeric IgA can be transported through living intestinal epithelial cells in vitro. The transport includes 1) specific binding of IgA dimers to secretory component on plasma membranes, 2) endocytosis of IgA in vesicles, 3) transcytoplasmic transport of the IgA-containing vesicles by a process involving microtubules, and 4) discharge of IgA at the apical surfaces.

Chromosome core structure revealed by silver staining

Chromosomes were subjected to either prolonged hypotonic solution pretreatment or aging. Both conditions greatly loosened and dispersed the overlying epichromatin from the central chromosome core structure. This was followed by silver staining and examination with bright-field microscopy. The chromosome core selectively reduced the silver and stained black while the surrounding epichromatin stained yellow. A single core was seen extending the length of each chromatid. Nucleolus organizer regions appeared to be attached to the core, while kinetochores seemed to be specialized regions of the core itself. Cytochemical tests indicated that the core component(s) responsible for silver staining was non-histone protein(s).

Electron microscopic studies on transplantable mucus-secreting and tubular adenocarcinomas of colo-rectal origin in ACI/N rats

Two transplantable, one mucus-producing (R-1) and the other tubular but less mucinous (R-2), adenocarcinomas were investigated electron microscopically. The R-1 tumor was composed of a large number of intermediate cells and mucus-producing cells, incompletely differentiated goblet-like cells and absorptive-like cells, and a small number of undifferentiated cells. The electron microscopic features of the mucus-producing cells exhibited distinctive features different from those of the epithelium of normal colon. They had highly electron-dense granules, expanded rER, well-developed mitochondria and Golgi apparatus. The R-1 tumor was found to be a well-differentiated adenocarcinoma in agreement with observations by light microscopy, while the R-2 tumor exhibited more malignant features than R-1.

Degradation of tight junctions in HT29, a human colon adenocarcinoma cell line

The process of tight junction degradation was followed in a cell line of human colon adenocarcinoma. Tight junctions are degraded by 2 mechanisms: (1) breakdown of junctional elements to intramembrane particles; (2) bleb formation by which tight-junctional elements are internalized into the cytoplasm or excluded into the medium. It is suggested that the first mechanism allows preservation of membrane particles for re-use, whereas the second is a mechanism by which the cells eliminate unneeded junctional elements.

Glycocalyceal bodies and microvillous core rootlets: their value in tumor typing

An ultrastructural study of the cell surface of lumen-forming tumors was carried out to determine the distribution of two morphologic markers seen in relation to the microvilli. These are membrane-bound glycocalyceal bodies and microvillous filament cores that penetrate the underlying cytoplasm as rootlets. They were found (especially when in combination) to be valuable in identifying tumors of what is referred to as intestinal-type epithelium, and could be seen in cases in which brush borders were absent. They have been demonstrated in intestinal-type carcinomas of the stomach and gallbladder, in adenocarcinomas of the small and large intestines and pancreatic ducts, in mucin-forming bronchiolar carcinomas, and in certain mucinous ovarian and endocervical tumors. Other tumors, whether mucin-producing or not, have been found to consistently lack these structures.

Association of intermediate filaments with other cell organelles in carcinoid tumor of the colon

Carcinoid tumor of the colon was studied in electron microscope. In cytoplasm, prominent intermediate-sized filaments were seen frequently attaching to nucleus and mitochondria. Direct contacts of intermediate filaments with secretory granules were not observed.

Nuclear fragmentation in colon carcinoma cells

The nuclei of the epithelial cells of well differentiated adenocarcinoma of the large intestine show characteristic appendages, the nucleotesimals, connected with the main nucleus by lamellar bridges. We interpret this phenomenon as being the result of a hitherto unknown type of amitosis that permits rapid cancer growth in spite of a low mitotic index.

Multiple granular-cell tumors of the ascending colon: microscopic study

Light and electron microscopic study of a case of multiple granular-cell tumor of the ascending colon is presented, and the relevant medical literature is reviewed. It seems that the biologic behavior of this tumor in the colon does not differ from that in other locations. Histologically, a few granular cells are seen in neural tissue in the vicinity of the tumor, suggesting a close relation of the tumor to the neural tissue. Electron-microscopically, the granular cells resemble Schwann cells more closely than neural cells and axons. Histochemically, the granules of the tumor cells show autofluorescence and high activity of acid phosphatase, which was located electron-microscopically in the limiting membranes and matrices of the granules. It is suggested that the granular-cell tumor is a neoplasm of Schwann-cell origin with a unique metabolism that causes acceleration of autophagocytosis and accumulation of ceroidlipofuscin.

Ultrastructural study of the normal mucosa-adenoma-cancer sequence in the development of familial polyposis coli

Ultrastructural changes that occurred in the colon epithelia of patients with familial polyposis coli were investigated. Criteria of gradation of the crescendo changes from the mucosa in the controls, through the "normal" mucosa between polyps and adenomas in various stages of dedifferentiation, to invasive carcinoma were established. Our criteria were based on the following requirements: a) vesiculation and increasing numbers of small electron-dense bodies (secretory granules) and lysosomes in the mature and immature absorptive cells, b) presence of immature and undifferiated cells, c) variation in the globlet cells and appearance of atypical secretory cells, and d) nuclear changes. The results illustrated the adenoma-carcinoma sequence and added strong evidence to support its occurrence. Furthermore, this ultrastructural study revealed cellular changes that preceded adenomatous growth and may be of value as markers of early stages of cancer. However, this study also revealed a close link between the function and morphology of the mucosal epithelium.

Serial cytogenetic studies of human colonic tumour xenografts

Chromosome studies have been made of 2 human colonic tumour lines maintained as xenografts in immune-deprived mice. In both tumours human karyotypes were retained, although progressive changes occurred during serial passage. In one tumour, independent gain of a chromosome 19 was found in the stemline and 2 sidelines. In the other tumour there was selection for a sideline containing a particular deleted marker chromosome. The advantages of chromosome analysis in a xenograft system, both for the study of human solid tumour karyotypes and for monitoring the continued presence of the human genome, are discussed.

Neuroendocrine carcinomas of the colon. Ultrastructural and biochemical evidence of their secretory function

Four cases of malignant colonic tumors diagnosed by light microscopy as "small cell undifferentiated carcinomas" were shown by electron microscopy to have neurosecretory-type granules. Biochemical analysis of tumor tissue extracts disclosed the presence of considerable levels of VMA and catecholamines in all tumors; 5-HIAA was present in one tumor. Clinically, there had been no signs or symptoms attributable to those or related substances. Similar observations have been reported in a variety of neuroendocrine neoplasms; for example, the demonstration of neurosecretory-type granules and determination of amine or peptide materials in tumor tissue or body fluids may not be necessarily reflected in clinical hormonal syndromes or obvious metabolic abnormalities. Our structural and biochemical observations indicate that, regardless of clinically evident hormonal activity or lack thereof, some small cell "undifferentiated" colonic cancers derive from APUD elements, and therefore they should be classified within the group of neuroendocrine carcinomas. The evident secretory capabilities of these carcinomas suggest obvious diagnostic possibilities and could conceivably lead to a reappraisal of current therapy.

Cytotoxicity of cyproheptadine and methysergide to chemically induced carcinomas of rat colon

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Isolation and purification of normal and malignant colonic plasma membranes

Plasma membrane fractions from normal colon cells and a transplantable colon adenocarcinoma were isolated and purified by differential and zonal density centrifugation. Enrichment of normal and adenocarcinoma plasma membranes was found in zonal fractions I and II (ZI and ZII) following centrifugation in an 18--50% sucrose gradient. The distribution of various marker enzymes in normal colon preparations suggested an apical origin for the membranes obtained in zonal fraction I while zonal fraction II appeared to contain basal-lateral membrane fragments. Enzymatic analysis of the plasma membrane derived from the colon tumor indicated that these fractions possess a more uniform distribution of Na-K+ ATPase perhaps reflecting a dedifferentiated state. The plasma membrane fractions isolated should prove useful for investigation of transport and other properties of vesicles derived from malignant and normal colon cells.

Ultrastructure of the "transitional" mucosa adjacent to large bowel carcinoma

The transitional mucosa immediately adjacent to large bowel carcinoma was examined in 13 patients by scanning electron microscopy (SEM), and this was correlated with transmission electron microscopy (TEM) and light microscopy (LM). Marked abnormalities were present in this mucosa in 9/13 patients with distortion and loss of the normal architecture. Examination of adenomas showed abnormalities also to be present adjacent to the neoplastic mucosa. In all patients, the transitional mucosa was compared with two pieces of normal mucosa; in one patient, typical changes of transitional mucosa were found in this region. In the remaining patients, normal mucosa by SEM was found to consist to large deep furrows (primary crypts) as well as the crypts of Lieberkuhn (secondary crypts). The secondary crypts structure showed marked individual variation between patients but one type was present in nine patients. It is uncertain whether this is a pattern with a high incidence in the general population, or whether patients with this type of mucosa are particularly predisposed to large bowel carcinoma. SEM may, therefore, play a part in identifying patients particularly likely to develop large bowel carcinoma.

Defective organization of actin in cultured skin fibroblasts from patients with inherited adenocarcinoma

In the cytoplasm of well-spread cultured normal fibroblasts, actin is organized into a network of cables that run the length of the cell just inside the adherent cell membrane. A diffuse matrix replaces the cables in fibroblasts that have become tumorigenic as a result of oncogenic transformation. We have found a similar disruption in actin organization in cultured skin fibroblasts (passage 6-10) obtained by biopsy from patients with the inherited colonic cancer, adenomatosis of the colon and rectum (ACR). Because ACR is inherited as an autosomal dominant trait, about half the children of ACR patients will develop colon cancer, but they typically remain asymptomatic until at least the second decade of life. Actin distribution within cultured cells from children of ACR patients was identical either to that seen in cultured cells from normal persons or to that seen in cultured cells from ACR patients. The two different patterns were independent of age, sex, drug treatment, or infections of the donors. Apparently, this class of colonic carcinoma is accompanied by a systemic aberration in the organization of fibroblast cytoplasm, and this aberration can be detected by immunofluorescent localization of actin within cultured skin fibroblasts, prior to manifestation of any colonic symptoms.

Flow-microfluorometric analysis of nuclei isolated from various normal and malignant human epithelial tissues. A preliminary report

In order to obviate some of the technical problems associated with preparation of monocellular cell suspensions required for flow fluorometry, isolation of nuclei from several types of benign and malignant human tissues was undertaken. Satisfactory preparations of nuclei were obtained from epithelia of the uterine cervix and colon and from lung tissue using the citric acid method. The sucrose method was effective with colonic epithelium only. Distribution of deoxyribonucleic acid content in these nuclei was measured based on green fluorescence of acridine orange and red fluorescence of propidium iodide in a Bio-Physics Cytofluorograph. Essentially diploid patterns of deoxyribonucleic acid distribution were observed for all benign samples regardless of tissue origin whereas the malignant samples gave histograms suggestive of abnormal deoxyribonucleic acid distribution. Preliminary observations on distribution of single-stranded nucleic acids using acridine orange red fluorescence showed marked differences between populations of benign and malignant nuclei. Isolated nuclei appear to be suitable for flow-through microfluorometric analysis and offer some significant advantages over intact cells.

Ultrastructural comparison of differentiation of stem cells of murine adenocarcinomas of colon and breast with their normal counterparts

Two rats with chemically induced transplantable adenocarcinomas of the colon were given pulses of [3H]thymidine, and autoradiography with electron microscopes was used to compare the degrees of differentiation of the stem cells of the tumor and colon. The best differentiated portions of the tumor had acini composed of vacuolated, mucous, and argentaffin cells in various stages of differentiation. Vacuolated and mucous cells incorporated [3H]thymidine and corresponded in degree of differentiation to that of their labeled normal counterparts in the normal colon. An exceedingly undifferentiated labeled cell, hitherto undescribed, was identified in the tumor and crypts of the colon; this may be an undifferentiated colon stem cell that differentiates into vacuolated and mucous stem cells and/or into argentaffin cells. Normal stem cells of the breast and malignant stem cells of spontaneous adenocarcinomas of the breast of C3H mice had comparable degrees of differentiation. Since normal stem cells in these tissues were as undifferentiated as the least differentiated stem cells of the tumors, there is now no need to postulate dedifferentiation as a mechanism to explain the undifferentiated appearance of tumors.

Ultrastructural features of the colonic epithelium in familial polyposis coli

Colectomy specimens from 6 cases of familial polyposis coli (FPC) were examined. Macroscopically normal mucosa between polyps was taken at intervals along the ascending, transverse and descending colons and studied at EM level. All three regions show the same cell populations varying only in their ratio and height of the epithelium. The same cell types seen in the normal crypt epithelium are present in the mucosa from FPC. As in the normal, 'intermediate' cells are present in FPC but they are less conspicuous than in the mucosa adjacent to colonic carcinoma. However, there are ultrastructural features which distinguish the "normal" mucosa in FPC from the true normal: (a) the presence of "clear columnar" cells; (b) increased vesiculation in the absorptive cells; (c) large number of lysosomes; and (d) the presence of small electron-dense bodies. The ultrastructure of the "clear columnar" cells suggests their being incompletely differentiated cells, thus raising the possibility that their presence in the upper crypt and surface epithelium may represent an early stage in the process of polyp and cancer formation.

Production of intestinal and other tumours by 1,2-dimethylhydrazine dihydrochloride in mice. II. Scanning electron microscopic and cytochemical study of colonic neoplasms

Thum of colon induced by repeated subcutaneous injections of 1,2-dimethyl-hydrazine dihydrochloride in mice were studied by scanning electron microscopy. In addition, the surface composition of normal and malignant colonic epithelial cells were investigated by ultrastructural cytochemistry. The neoplastic, nodular tumour masses which protruded into the lumen of colon displayed an asymmetrical, irregular growth pattern and surface contour. In contrast to the normal surface structure, the shape of crypt openings in malignant areas was distorted and they were irregularly spaced. Cells varying in size and shape in the intercrypt regions often formed random patterns of elevations and depressions. Microvilli on neoplastic cells were larger, more club-shaped and showed more disorderly arrangement than their normal counterparts. The distribution and quantity of surface acid mucopolysaccharide content and adenosine triphosphatase activity varied considerably from cell to cell in the neoplastic epithelium while they were more uniform in the normal colonic surface cells.

Establishment of a cell line (Co-115) from a human colon carcinoma transplanted into nude mice

A human colon carcinoma cell line, Co-115, has been established in vitro from solid xenografts maintained in nude mice and subcultured for 95 passages. Co-115 cells grow in vitro as tightly packed, epithelial-like colonies, have a doubling time of about 36 hr, have a relatively low plating efficiency in agar, and release significant amounts of carcinoembryonic antigen to the culture medium. Their epithelial nature has been confirmed by ultrastructural examination. The injection of Co-115 cells into nude mice reinduced the formation of solid tumor masses that could be retransplanted and showed a morphology comparable of that of the original xenograft.

Cell surface alterations on colon adenocarcinoma cells

By the use of five independent techniques, cell surface alterations distinctive of malignant as compared to normal colon cells were detected on in vivo surgical specimens and on cultured cell lines established in our laboratory. The findings, which were distinctive of the malignant as compared to the normal cell included: (a) polymorphism of surface microvilli on scan electron microscopy; (b) decreased susceptibility to infection with vaccinia and reovirus, but not to herpes, adeno- or echovirus: (c) production of large quantities of carcinoembryonic antigen; (d) presence of specific membrane proteins on sodium dodecyl sulfate-polyacrylamide gel analysis of plasma membranes purified from cell homogenates by ultracentrifugation in polyethylene glycol-dextran partitions; and (e) reaction with specific, cytotoxic, rabbit heteroantisera. Solubilized extracts of the malignant cells formed precipitin lines with the heteroantisera, suggesting that the distinctive antigens could be released from the cell surface. These results suggest that human colon carcinomas bear tumor-distinctive proteins and offer the prospect of specific immunodiagnostic reagents and immunotherapeutic tools.

Electron microscopy in the cytological examination of metastatic pleural effusions

In a previous publication the ultrastructure of pleural effusions in cases of pleural mesothelioma was reported. The same method has now been applied to a study of effusions produced by pleural metastases. The findings are considered sufficiently conclusive to justify the use of electron microscopic cytology in determining the nature and sometimes the origin of such effusions.

Nature of juvenile polyps in the large intestine

Forty-five juvenile polyps were found among approximately 390 mucosal polyps of the large intestine. Various degrees of epithelial pseudostratification were found among juvenile polyps and the larger-sized polyps of both juvenile type and adult one tended to have a more advanced degree of epithelial pseudostratification. The glands of both juvenile polyps and adult ones revealed a closely resembled or almost identical pattern of size-distribution-pattern of the glandular size in both normal mucosae and hyperplastic mucosae of long-standing ulcerative colitis. Transition of juvenile polyps into adult ones was suggested by the cases with increase in numbers of glands and their orifices to the surface of the polyp and there were some polyps showing an intermediate form between juvenile polyps and adult ones. On the basis of histologic characteristics and age incidence of the patients, it may be said that a juvenile polyp is an immature variant of an adult polyp.

Villous adenoma of the colon and rectum: an ultrastructural study

The villous component of nine colonic polyps (three pure villous adenoma and six mixed adenomatous and villous adenomas) was studied by light and electron microscopy. Normal colonic mucosa was used for control. The predominant cell was an undifferentiated epithelial cell resembling those of the base of the crypts of normal colonic mucosa. A minority of these cells differentiated toward goblet cells and absorptive cells. Interdigitations of the plasma membrane with enlarged intercellular spaces were frequently observed, possibly related to the loss of water and electrolytes in some of these tumors, suggesting an analogy to renal tubular plasma membrane changes in kalliopenic nephropathy. Numerous membrane-bound, inter and intracellular "inclusion bodies" representing degenerated lymphocytes and epithelial cell organelles were commonly found. Viral inclusions were not detected in this material. The possibility that the inclusion bodies observed in villous adenoma may represent lysosome-modified vesicles, secondary to absorption of protein and surface mucosubstances appears unlikely.