Biomedical subjects

H Logothetou-Rella

Publications and source records attributed to H Logothetou-Rella.

17 recordsLinked to original sources

PubMed2000

Induction of DNA synthesis or apoptosis in mammalian nuclei by Xenopus egg extracts that fail to support the replication of sperm chromatin.

Cell-free extracts of Xenopus eggs are widely used to study DNA replication in higher eukaryotes. However, with Xenopus sperm chromatin as template, it is a common experience that the efficiency of replication varies from extract to extract, for reasons that are unclear. Here we show that the majority of extracts unable to support sperm replication are nevertheless able to induce DNA synthesis in intact mammalian nuclei. Those that do not, induce apoptosis.

3T3 Cells↗

PubMed1996

Meiosis in hematological malignancies. In situ cytogenetic morphology.

This is the first study on the in situ cytogenetic morphology and analysis of malignant bone marrow cells, growing attached on a culture vessel surface. It was documented that bone marrow cells, in different types of hematological malignancies, divide by meiosis giving rise to a non-repetitive aneuploidy. Male and female gametes are formed by meiosis and fertilization occurs in a life cycle of: [sequence see text] Immature and mature somatic oocytes were evidenced by prophase stages of the first and diploid or hypodiploid or haploid metaphases identical to those of the second human, ovarian oocytic meiotic division, showing "XX" or "XY" sex chromosomes in female or male patients respectively. Nuclear vlimata were the male gametes showing a condensed head with tail morphology. Metaphases of nuclear vlimata were aneuploid, keeping the head with tail shape, carrying chromosomes identical to those of human spermatogonia. Somatic metaphases identical to those of human spermatocytes in meiosis II and spermatogonia were demonstrated. The process of fertilization was documented by nuclear vlima invasion into host cell metaphases, by metaphases of fertilized oocyte showing both the female chromosome "0" and the male chromatids "s" and hybrid metaphases of oocytic with somatic chromosomes. Meiosis was characterized by nuclear extrusion of chromosomes, meiotic, condensed chromosomes, nuclear vlimata, metaphase and nuclear fusion, hybrid metaphases, nuclear budding, nuclear conglomerates, nuclear bridges, chromosomal fusion substance, transfer of chromosomes and non-repetitive aneuploidy. Meiotic, Double Minute, ring and minute chromosomes extruded by nuclei were loaded with glycoproteins, glycosaminoglycans and calcium-activated neutral proteinase, distinguishing them from mitotic chromosomes. The main characteristic events of meiosis, observed in malignant bone marrow cells, were also demonstrated in fungal and rat testicular cells, known to divide by meiosis.

Aneuploidy↗

PubMed1996

Description of primordial germ cells, oogonia, oocytes and embryo-like growth in squash preparations of tissues from hematological malignancies.

This study evidences the presence of primordial germ cells, in tissue squash preparations and sections from hematological malignancies. Primordial germ cells were identified by their morphology, the intense PAS, PAS-D reaction and presence of calcium-activated neutral proteinase. Primordial germ cells gave rise to nuclear vlimata. Immature oogonia exhibited a nuclear envelope and a star-shaped nuclear core, arising from acellular globose bodies impregnated by a nuclear vlima of primordial germ cell. Bone marrow tissue oogonia were PAS and PAS-D positive, identical to fungal ones. Calcium-activated neutral proteinase was demonstrated in the plasma of the acellular globose bodies, the nuclear envelope and the conglomerated primordial germ cells. Immature bone marrow oogonia progressed into mature ones, leptotene, diplotene, dictyotene and mature oocytes. Nuclear vlimata fertilized primordial germ cells, oogonia and oocytes, giving rise to round embryos at the morula and hatching morula-like stages. Embryos consisted of a zonapellucida-like cortex, composed of glycosaminoglycans, glycoproteins, protease and diffuse nuclear material, enclosing developing cells. Primordial germ cells, oogonia and embryos were also demonstrated in squash preparations of adult rat testis and sections of normal rat bone marrow tissues. The observations document that primordial germ cells are the primary stem cells which give rise to nuclear vlimata and oogonia, which constitute the secondary stem germ cells. The results are discussed in terms of stem cell renewal according to the events: primordial germ cells-gametes-fertilization-embryos-primordial germ cells.

Animals↗

PubMed1995

Nuclear vlimata and aneuploidy in embryonic cells is caused by meiosis. Behaviour and properties of meiotic cells.

This study demonstrates that human embryonic cells divide by meiosis. The use of trophoblastic tissue cells (early embryo) and amniotic cells (late embryo) exhibited the following characteristic events of meiosis: nuclear (NVs) and nucleolar (NuVs) vlimata formation; NV invasion in host cells; extrusion of chromosomes; nuclear fusion; metaphase fusion; hybrid cell formation; nuclear, nucleolar and cytoplasmic bridges, chromosomal transfer, variable-sized nuclei; nuclear fragmentation; condensed meiotic chromosomes; "O" chromosome; and aneuploidy. Two types of nuclear bridges (NBs) were identified and defined as communicative tubules through which chromosomal transfer among cells is achieved. The wall of NBs is an extension of the nuclear membrane and the lumen contained chromosomal fusion substance (CFS). Embryonic cells formed glycosaminoglycan-sacs (GSG-sacs) and rivulets, forming a cytoplasmic communicative system. The extracellular matrix (ECM), GSG-sacs and CFS were composed of glycosaminoglycan-bound protease. The protease which immuno-crossreacted with the a1-chymotrypsin antiserum was the meiotic calcium-activated activated neutral proteinase (CANP). Cytogenetic analysis of early embryonic cells showed higher ratio of aneuploidy:diploidy than late embryonic cells. The results are discussed in terms of differentiation-mitosis and undifferentiation-meiosis. These observations lead to an embryonic cell life cycle identical to that of malignant cells as follows: [formula: see text].

Adult↗

PubMed1995

The inhibitor of calcium activated neutral proteinase is an anti-meiotic agent. The spermicidal and anti-viral action.

In situ cytogenetic morphology and analysis showed that Epstein-Barr Virus (EBV)-infected Raji and EBV-producing P3HR-1 cells divide by meiosis and follow the life cycle of malignant cells in vitro. Meiosis was documented by the presence of condensed chromosomes, "o" chromosome, nuclear vlimata (NVs), NV invasion, extrusion of chromosomes, chromosomal transfer, metaphase fusion and aneuploidy. EBV-Raji, EBV-producing P3HR, HIV1-infected MOLT-4 cells (dividing by meiosis) and human spermatozoa (cellular products of meiosis) were highly sensitive to the endogenous inhibitor (CANP-I) of calcium-activated neutral proteinase (CANP). CANP-I-treated virally infected and virus producing cells showed necrosis and disappearance of immunofluorescent viral antigens, documenting the anti-viral action of CANP-I. CANP-I-treated spermatozoa exhibited arrested motility with subsequent necrosis documenting the in vitro spermicidal action of CANP-I. The testis of treated Wistar rats with 0.25 U CANP-I/gr body weight for six days, were devoid of spermatozoa, with pronounced toxicity and exfoliation of spermatocytes and spermatids, indicating the contraceptive action of CANP-I via spermatogenetic arrest. It is concluded that CANP-I is an anti-meiotic agent inhibiting CANP associated with meiosis. Hence CANP-I is a promising agent against various diseases involving meiosis.

Animals↗

PubMed1994

Cytogenetic analysis and morphology of malignant nuclear vlimata. The life cycle of malignant cells.

The karyotype of malignant nuclear vlimata (NVs) was investigated with the in situ and chromosomal spreading techniques. NV metaphases were recognised by the head with tail morphology, kept in situ and evaluated by the chromosomal spreading technique. It was shown that malignant NVs were produced by random, uncontrolled meiosis. NVs contain and carry single, hypodiploid, haploid, hypohaploid, hyperdiploid and atypical sets of chromosomes. NVs are unstable parasitic cellular elements, invading the cytoplasm or the nucleus of host cells, extruding and implanting their chromosomes in the host cell upon contact. Within a malignant cell culture, NVs play the role of chromosomal donors and host cells of chromosomal recipients. NVs were identified as episomatic on host cell nuclei or incorporated into host cell metaphases. The observations are discussed in terms of fertilization, viral infection and apoptosis. Comparison of malignant NVs with phytohaemagglutinin (PHA)-activated lymphocytic NVs is provided, as well as the life cycle of the malignant cells as follows: [Formula see text] cells (Logothetou-Rella, 1993). Phytohaemagglutinin (PHA)-activated lymphocytes also produced NVs by meiosis, carrying hypodiploid, haploid and hypohaploid sets of chromosomes (Logothetou-Rella, 1994a). In this study the cytogenetic analysis and morphology of malignant NVs are investigated, using a) the in situ cytogenetic technique, and b) the chromosomal spreading technique.

Aneuploidy↗

PubMed1994

Differentiation of human lymphocytes into nuclear vlimata by meiosis. The cytotoxic effect of calcium-activated neutral proteinase inhibitor.

Phytohaemagglutinin (PHA)-activated lymphocytes differentiated into nuclear vlimata (NVs) in vitro. Lymphocyte attachment was followed by formation and extrusion of cytoplasmic vesicles, nuclear elongation and fragmentation into NVs. NVs and cytoplasmic vesicles were detached and organized into large cell nodules in suspension. Immunocytochemistry showed that T-lymphocytes differentiated mainly to NVs while B-lymphocytes to buds. During differentiation there was a loss or gain of T-antigenicity by either mother or daughter cell. Cytogenetic analysis by chromosomal spreading and in situ techniques showed that NVs do carry chromosomes of hypodiploid or hypohaploid sets. NVs were the result of meiosis stimulated by PHA. A lymphocytic population exhibited diploidies attributed to mitosis or symmetrical meiosis and hypodiploidies, hypohaploidies attributed to meiosis. A comparison between NVs and spermatozoa was provided. The inhibitor of calcium-activated neutral proteinase (CANP-I) was cytotoxic to NVs without interfering with NV production. A model was proposed for the action of CANP-I which is a promising agent against autoimmune diseases.

B-Lymphocytes↗

PubMed1994

The selective anticancer activity of the endogenous inhibitor of calcium-activated neutral proteinase. A histological, cytological and chemosensitivity study.

The cytotoxicity of an endogenous inhibitor of calcium-activated neutral proteinase (CANP-I) was evaluated using various mammalian tumor-derived cell lines and human cell cultures. The inhibitor was selectively cytotoxic to human tumor cells from lung, bladder, melanoma and chronic myeloid leukemia tissues, in a dose-dependent manner, and was also cytotoxic to Walker rat tumor cells. The inhibitor was not cytotoxic to normal human, urothelial, fallopian tube, liver and resting white blood cells. Cytological examination of the treated malignant cells revealed cells with vacuolated cytoplasm, pyknotic, hyperchromatic nuclei and membranous, granular haematoxylinophilic extracellular matrix. The use of the inhibitor on urothelial tumor tissues caused great exfoliation of necrotic cells while not affecting normal urothelial tissues. When the inhibitor was tested on mixed cell cultures, consisting of normal and malignant cell clones, a selective cytotoxicity to the malignant cells occurred allowing the normal cells to grow unaffected. Cytogenetic and cytological examination of the remaining cells, after the inhibitor treatment, showed normal diploid karyotype and morphology. The inhibitor was also tested in vivo on Wistar rats bearing Walker tumors. Treatment with 50 Units/100 g i.p. daily for 5 days caused 90% tumor regression and necrosis of metastatic foci in the liver and abdomen, without toxic side effects. The protease inhibitors trypsin-chymotrypsin, aprotinin, leupeptin and E64 were also tested in vitro and showed no anticancer activity. In conclusion, the endogenous inhibitor of CANP selectively killed malignant cells of different chromosomal abnormalities, tissue and species origin; also nuclear vlimata and chemoresistant cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1994

Glycosaminoglycan-sac formation in vitro. Interactions between normal and malignant cells.

The interaction of monolayer normal human or normal rat cells with suspension Walker rat tumor cells was demonstrated cytologically, during a cocultivation period of thirty days. At ten days, Walker rat tumor cells were interiorized in the cytoplasm of the normal monolayer host cells. At twenty days, degeneration of the interiorized tumor cells followed by mucification led to glycosaminoglycan-sac formation. At thirty days, tumor nodules and protease (alpha 1-chymotrypsin)- bound glycosaminoglycan(s) extracellular matrix, transversing the culture in membranous rivulets, were formed. The overall interaction resulted in the death of the interiorized tumour cell and survival of the normal host cells containing a glycosaminoglycan-sac. The use of bladder tumor cell imprints showed that cell interiorization, degeneration and extracellular matrix formation identical to that of the co-cultures, also occur in vivo. Cell interiorization within malignant cell cultures led to syncytia formation and survival of both host and interiorized cells. Identical glycosaminoglycan extracellular matrix to that of the co-cultures and syncytia was also observed in smears of EBV-producing (P3HR-1) cell cultures. The observations are discussed in terms of invasion, emperipolesis, cannibalism, phagocytosis and extracellular matrix. It is concluded that a glycosaminoglycan-sac is produced by the interiorization of a tumor cell into a normal cell while interiorization of a tumor cell into another tumor cell resulted in syncytia formation.

Animals↗

PubMed1993

Lymphocyte interactions with the extracellular matrix of malignant cells in vitro: a morphological and immunocytochemical study.

The interactions of lymphocytes with the glycosaminoglycans-protease-membrane extracellular matrix, produced by mixed cell cultures of normal with malignant cell clones, were examined. Pre-activated and activated heterologous peripheral lymphocytes were used. Co-cultures of activated lymphocytes with all cell types used, formed identical cell nodules. Histology of cell nodules showed that activated lymphocytes were cytolytic to pure normal or malignant cell clones. On the contrary, lymphocytes in nodules with mixed cell clones (normal with malignant cell clones) or embryonic cells, underwent degeneration changing the fusiform type tumor nodule into the adenoid type. The adenoid type cell nodule consisted of cells with high nuclear to cytoplasm ratio and mitotic activity. In addition, leukocyte common antigen was deposited in the extracellular matrix and on the cell membrane of target tumor cells. Pre-activated lymphocytes, in mixed cell cultures, failed to lyse the target tumor cells and underwent abnormal cell divisions, producing subsets similar to nuclear vlimata, which remained attached to the extracellular matrix. The morphological and immunocytochemical observations of lymphocytes were discussed and attributed to the presence of the specific extracellular matrix of glycosaminoglycans-protease-membranes.

Amniotic Fluid↗

PubMed1993

Spermatozoa-like cell invaders (nuclear vlimata) in human neoplasia.

Spermatozoa-like cells (nuclear vlimata) have been identified in malignant cell cultures and embryonic cells, also common in the cytology and histology of all types of human neoplasia even after chemotherapy. A new mechanism of invasion of malignant cells has been described, according to which neoplastic cells behave and function as parasites using host-cells to divide, survive and eventually produce nuclear vlimata (bullets). Nuclear vlimata are the end cell products of incomplete, unequal, assymetrical division of neoplastic cells. The nuclear vlima exhibits similar morphology to spermatozoa and virus (head with, or without, tail) and invades the cytoplasm and/or nucleus of surrounding host-cells by a similar mechanism to sperm-oocyte interaction (fertilization) or viral cell infection, in the events of nuclear vlima-->tumor-->nuclear vlima-->tumor. The nuclear vlima head contains and transfers DNA, and when incorporated into the host-nucleus is indistinguishable from nucleoli and when in the cytoplasm is similar to sperm pronucleus, observed after sperm penetration of the oocyte. Function of nuclear vlimata is directly dependent on the specific extracellular matrix produced by malignant cells, consisting of glycosaminoglycans-protease-membranes. This mechanism of invasion constitutes the link of all scientific information concerning human neoplasia.

Animals↗

PubMed1992

A cytologic, ultrastructural and immunocytochemical comparison of tumor cells and cell cultures originating in invasive bladder carcinoma.

Tumor cells and urine-voided cells from patients with invasive bladder carcinoma as well as from healthy patients were examined cytologically, ultrastructurally and immunocytochemically. The ultrastructure of tumor cells showed an abundant, dilated, rough endoplasmic reticulum in the form of membrane-bound vacuoles full of granular to fibrillar material located perinuclearly and/or paranuclearly. Some cells exhibited enlarged modified lysosomes containing sparce flocculent and particulate precipitate. Papanicolaou staining of these cells showed two basophilic cytoplasmic textures, one green glossy-patchy, perinuclearly and/or paranuclearly, well segregated from the other texture of peripheral hematoxylinophilic foamy cytoplasm, comparable to the cytologic features of cell cultures originating in invasive bladder carcinoma. PAS diastase showed double distribution and texture of the perinuclear glycosaminoglycans, a glossy accumulated mass and large granules. Glycosaminoglycan sacs similar to those of cell cultures were also present in tumor-dispersed cells. There was a nonspecific binding of antisera against lysozyme, human chorionic gonadotropin and alpha 1-trypsin in normal and tumor cells. Tumor cells and tissues were positive for alpha 1-chymotrypsin distributed perinuclearly and in large spheres. Normal cells lacked the above characteristics. The results indicate that it is feasible to use the aforementioned characteristics in conjunction with the existing bladder-cytologic criteria for malignancy as markers in urothelial cancer with regard to prognosis of superficial tumors with high malignant potential.

Carcinoma, Transitional Cell↗

PubMed1990

Canine capillary formation in vitro.

Microvascular endothelial cells derived from canine subcutaneous adipose tissue formed knob-like and tube-like structures in vitro without tumor-conditioned medium or special substrate. The knob-like structures consisted of acidic and basic glycosaminoglycans arranged in order. Knob-like structures were built from cell extrudates and were responsible for capillary lumen formation in vitro. Transmission electron microscopy confirmed the endothelial nature of the cells which expressed extensive phagolysosomal activity.

Animals↗

PubMed1989

Early human trophoblast cell cultures. A morphological and immunocytochemical study.

Rapidly growing cytotrophoblasts were isolated from early human chorionic villi and the Papanicolaou method was used to characterize their cytology and transformation into syncytiotrophoblasts. Cytotrophoblasts fused and formed binucleated cells or mononucleated intermediate cells. Syncytial cells were formed by fusion of small cytotrophoblasts or intermediate cells and cytotrophoblasts. Glycosaminoglycans were produced in cytotrophoblasts and released extracellularly. Here they were accumulated and/or diffused into a continuous layer covering the cells. Glycosaminoglycans in syncytial cells were contained in well defined membranous sacs. Cytotrophoblasts only grown beyond confluence differentiated into villi with a villus-like histology.

Cells, Cultured↗

PubMed1988

Common characteristics of primary cell cultures originated from invasive urothelial carcinoma.

Ten primary cultures from invasive urothelial carcinomas were studied by light and electron microscopy. In all cultures, cells with accumulations of glycosaminoglycans were observed. Long membrane extensions with accumulations of glycosaminoglycans invaded neighboring cells and formed an extracellular matrix as well. The extracellular matrix inhibited cell proliferation and enhanced tumor nodule formation.

Aged↗

PubMed1988

Morphological and immunohistochemical characteristics of a cell line originated from noninvasive human bladder transitional-cell carcinoma.

A cell line (IG) was derived from a noninvasive transitional cell carcinoma grade II. The cells were propagated in vitro for 9 months, had a low proliferative capacity, formed tumor nodules, and showed four characteristic morphological stages. Primary epithelial-like cells were characterized as stage I; fibroblast-like cells with loss of contact inhibition of growth as stage II; fibroblast-like cells with long cytoplasmic projections, massive glycosaminoglycan content and tumor nodule formation as stage III; and, as stage IV, granulated stellate cells. The cell culture progressed cytologically from well-differentiated stage I to less-differentiated stage IV. The four stages were confirmed and examined by electron microscopy. Immunoreactivity for fibronectin, keratin, epithelial membrane antigen and carcinoembryonic antigen shown by the cell line and the tissue indicates that the cell line represents the original cell population in the tumor. Glycosaminoglycan production by these cells was found to be responsible for the formation of tumor nodules which appeared in culture at the same time as the patient had developed an invasive bladder tumor. Glycosaminoglycans were observed as a massive accumulation intracellularly and extracellularly, as rods or thick slices in layers of adherent vesicles and granules covering the cell culture. Normal bladder epithelial cells and fibroblasts grew in monolayer, showed contact inhibition of growth, were devoid of intracellularly accumulated glycosaminoglycans and produced uniform extracellular matrix different from that of IG cells.

Adult↗

PubMed1988

Growth characteristics of cultured human normal bladder epithelial cells: a comparison with urothelial carcinoma cell cultures.

We present the in vitro growth characteristics and morphology of the first established long-term culture of human normal bladder epithelium. Normal bladder cells were grown with a mean generation time of 44 h and a life span of 33 population doublings in 12 weeks. The cells exhibited contact inhibition of growth. The cultures were morphologically examined and compared with transitional cell carcinoma in culture.

Adult↗