A new and rapid method for diagnosis of vaginal and cervical cancer by fluorescence microscopy

Circulating mitochondria DNA, a non-invasive cancer diagnostic biomarker candidate

The mitochondria are defined by their unique structure and cellular functions which includes energy production, metabolic regulation, apoptosis, calcium homeostasis, cell proliferation, cell motility and transport as well as free radical generation. Recent advances geared towards enhancing the diagnostic and prognostic value of cancer patients have targeted the circulating mitochondria genome due to its specific and unique characteristics. Circulating mitochondria DNA is known to possess short length, relatively simple molecular structure and a high copy number. These coupled with its ability to serve as a liquid biopsy makes it an easily accessible non-invasive biomarker for diagnostics and prognostics of various forms of solid tumors. In this article, we review recent findings on circulating mitochondria DNA content in cancer. In addition, we provide an insight into the potential of circulating mitochondria DNA to act as a non-invasive diagnostic biomarker and its linearity with clinical and sociodemographic characteristics.

5-Aza-2'-deoxycytidine acts as a modulator of chondrocyte hypertrophy and maturation in chick caudal region chondrocytes in culture

This study was carried out to explore the effect of DNA hypomethylation on chondrocytes phenotype, in particular the effect on chondrocyte hypertrophy, maturation, and apoptosis. Chondrocytes derived from caudal region of day 17 embryonic chick sterna were pretreated with hypomethylating drug 5-aza-2'-deoxycytidine for 48 hours and then maintained in the normal culture medium for up to 14 days. Histological studies showed distinct morphological changes occurred in the pretreated cultures when compared to the control cultures. The pretreated chondrocytes after 7 days in culture became bigger in size and acquired more flattened fibroblastic phenotype as well as a loss of cartilage specific extracellular matrix. Scanning electron microscopy at day 7 showed chondrocytes to have increased in cell volume and at day 14 in culture the extracellular matrix of the pretreated cultures showed regular fibrillar structure heavily embedded with matrix vesicles, which is the characteristic feature of chondrocyte hypertrophy. Transmission electron microscopic studies indicated the terminal fate of the hypertrophic cells in culture. The pretreated chondrocytes grown for 14 days in culture showed two types of cells: dark cells which had condense chromatin in dark patches and dark cytoplasm. The other light chondrocytes appeared to be heavily loaded with endoplasmic reticulum indicative of very active protein and secretory activity; their cytoplasm had large vacuoles and disintegrating cytoplasm. The biosynthetic profile showed that the pretreated cultures were actively synthesizing and secreting type X collagen and alkaline phosphatase as a major biosynthetic product.

Confocal microscopy and exfoliative cytology

Context:

Early detection of potentially malignant lesions and invasive squamous-cell carcinoma in the oral cavity could be greatly improved through techniques that permit visualization of subtle cellular changes indicative of the neoplastic transformation process. One such technique is confocal microscopy. Combining rapidity with reliability, an innovative idea has been put forward using confocal microscope in exfoliative cytology.

Aims:

The main objective of this study was to assess confocal microscopy for cytological diagnosis and the results were compared with that of the standard PAP stain.

Settings and Design:

Confocal microscope, acridine orange (AO) stain, PAP (Papanicolaou) stain. The study was designed to assess confocal microscopy for cytological diagnosis. In the process, smears of patients with (clinically diagnosed and/or suspected) oral squamous cell carcinoma as well as those of controls (normal people) were stained with acridine orange and observed under confocal microscope. The results were compared with those of the standard PAP method.

Materials and Methods:

Samples of buccal mucosa smears from normal patients and squamous cell carcinoma patients were made, fixed in 100% alcohol, followed by AO staining. The corresponding set of smears was stained with PAP stain using rapid PAP stain kit. The results obtained were compared with those obtained with AO confocal microscopy.

Results:

The study had shown nuclear changes (malignant cells) in the smears of squamous cell carcinoma patients as increased intensity of fluorescence of the nucleus, when observed under confocal microscope. Acridine orange confocal microscopy showed good amount of sensitivity and specificity (93%) in identifying malignant cells in exfoliative cytological smears.

Conclusion:

Confocal microscopy was found to have good sensitivity in the identification of cancer (malignant) cells in exfoliative cytology, at par with the PAP method. The rapidity of processing and screening a specimen resulted in saving of time. It added a certain amount of objectivity to the process of arriving at a diagnosis.

System approaches of Weiss and Bertalanffy and their relevance for systems biology today

System approaches in biology have a long history. We focus here on the thinking of Paul A. Weiss and Ludwig von Bertalanffy, who contributed a great deal towards making the system concept operable in biology in the early 20th century. To them, considering whole living systems, which includes their organisation or order, is equally important as the dynamics within systems and the interplay between different levels from molecules over cells to organisms. They also called for taking the intrinsic activity of living systems and the conservation of system states into account. We compare these notions with today's systems biology, which is often a bottom-up approach from molecular dynamics to cellular behaviour. We conclude that bringing together the early heuristics with recent formalisms and novel experimental set-ups can lead to fruitful results and understanding.

Nucleic acid distribution pattern as a possible biomarker for metabolic activities of neoplastic cells: a digitally-aided fluorescence microscopy study on normal and neoplastic lymphocytes of acute and chronic canine lymphocytic leukemia

Background

Metabolic states of neoplastic cells are increasingly being relied upon for diagnostic and prognostic assessment of neoplastic conditions. The nucleic acid distribution pattern of cells in general, in terms of degree of condensation of the nuclear chromatin and overall spread of the nucleic acid within the nuclear and cytoplasmic compartments, can reflect the metabolic state of the cell. This simple but logical concept appears not be put into consideration to date as numerous attempts are being made towards formulating reliable biomarkers for rapid diagnosis, prognosis and subsequent therapeutic interventions for neoplastic conditions. We comparatively evaluated nucleic acid distribution patterns of normal lymphocytes and neoplastic cells of lymphocytic lineage, employing light and fluorescence microscopy procedures, as well as digital imaging analytical methods.

Results

The results demonstrate distinctiveness in the pattern of nucleic acid distribution for the normal lymphocytes and three lymphocytic neoplastic cell-types of canine lymphocytic leukemia that are categorized as small, intermediate and large neoplastic lymphocytes. Variably-shaped cytoplasmic processes laden with single-stranded nucleic acids (SSNA) were observed for the small and intermediate-sized neoplastic lymphocytes, compared with large neoplastic lymphocytes and the normal lymphocytes; the latter two categories of cells being virtually devoid of similar processes. Prominent cytoplasmic and nuclear clumps of SSNA, indicative of a higher rate of metabolic activity, were also observed within the neoplastic cells compared with fewer and narrower SSNA of the normal cells.

Conclusion

The comparative relative increases of SSNA in cytoplasmic processes and other cellular areas of small and intermediate-sized neoplastic lymphocytes is reflective of greater metabolic activity in neoplastic cells in general compared with their normal cellular counterparts.

Nucleic acid distribution pattern in avian erythrocytes and mammalian lymphocytes: comparative studies by fluorescence microscopy and digital imaging analytical techniques

Nucleated erythrocytes of healthy domestic chicken and ducks, and lymphocytes of healthy Sprague Dawley rats were evaluated for nucleic acid distribution pattern, employing light and fluorescence microscopy procedures, as well as digital imaging analytical methods. The results demonstrate a unique organization of nuclear DNA of mature chicken and duck erythrocytes, as well as immature duck erythrocytes, as delineated spherical nuclear bodies that mostly corresponded with euchromatin zones of the cells in routine Wright-stain blood smears. The nuclear DNA of the rat lymphocytes, on the other hand, was observed as a more diffuse green fluorescing nuclear areas, with punctate variably-sized diffuse areas of RNA red fluorescence. RNA red color fluorescence was also evident in the narrow cytoplasm of the lymphocytes, especially in large lymphocytes, in comparison with the cytoplasm of the mature avian erythrocytes that completely lacked any nucleic acid fluorescence. Nuclear RNA fluorescence was lacking in the mature chicken erythrocytes, compared with those of the mature and immature duck erythrocytes as well as lymphocytes of both avian and rats blood. The significance of these findings lies in the establishment of normal benchmarks for the nuclear and cytoplasmic nucleic acid pattern in eukaryotic cells. These normal benchmarks become valuable in rapid diagnostic situations associated with pathologies, such as the presence of viral nuclear and cytoplasmic inclusion bodies that can alter the nucleic acid pattern of the host cells, and in conditions of cellular abnormal protein aggregations. Variability of cellular nucleic acid pattern can also aid in prognostic assessments of neoplastic conditions.

Fluorescence microscopy in exfoliative cytology

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Correlation between ultrastructural and histochemical parameters in lymphokine-activated killer (LAK) cells reacting with target cells in vitro

Ultrastructural and fluorescence data allowed us to study the most important moments of the interaction between lymphokine-activated killer (LAK) cells against target cells (Chang) in vitro. The LAK cells, maintained at low doses of recombinant interleukin-2, were able to recognize, bind and destroy the tumoral cells. Before the attack, the LAK cells were characterized by a cytoplasm with a high ribosomes content; after the identification and the interaction cell-cell, a degeneration of the tumoral cell was observed. These observations allowed us to suppose that the interaction between the two types of cells may be mediated by a receptoral membrane system without the action of lytic enzymes.

Simple technique for fluorescence staining of blood cells with acridine orange

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The role of inhibitors in the fluorescent staining of benign naevus and malignant melanoma cells with 9-amino acridine and acridine orange

Guanidinobenzoatase is a trypsin-like protease capable of degrading fibronectin. An inactive form of guanidinobenzoatase is present on the surface of benign naevus cells and these cells stain very weakly with 9-aminoacridine, a known competitive inhibitor of guanidinobenzoatase. Malignant melanoma and metastatic malignant melanoma cells exhibit strong surface staining with 9-aminoacridine and also exhibit strong staining of cytoplasmic RNA with acridine orange. These simple fluorescent techniques have been used to distinguish benign naevus cells from malignant melanoma cells in human skin sections. This difference in cell surface staining with 9-aminoacridine has been demonstrated to be caused by the presence or absence of an inhibitor. The inhibitor can be displaced from the cell surface enzyme and then replaced by an affinity purified inhibitor obtained from fresh liver homogenates. It is proposed that the inhibition or control of cell surface guanidinobenzoatase may be one of the regulatory mechanisms by which benign naevus cells are prevented from developing into malignant melanoma cells.

Probing the phagolysosomal environment of human macrophages with a Ca2+-responsive operon fusion in Yersinia pestis

Several microorganisms, including Yersinia sp., Salmonella sp., Brucella sp., Mycobacterium sp. and Leishmania sp., have successfully adapted to grow within macrophage phagolysosomes. Infections caused by these intracellular pathogens are among the most difficult to treat. As part of an antimicrobial strategy directed at modifying the phagolysosomal environment to the disadvantage of these important pathogens, we are defining the ambient conditions within the organism-containing phagolysosome. To probe this environment, we have used Yersinia pestis, whose expression of several virulence attributes is highly dependent on the Ca2+ concentration in its growth environment. We first genetically engineered a strain of Y. pestis which responds to a low-calcium environment by transcription of inserted structural genes of the Escherichia coli lac operon. Using this mutant organism as a relevant biological probe, we demonstrate here that the calcium concentration in Y. pestis-containing phagolysosomes is sufficiently low to permit virulence gene expression; this resolves the question of where Y. pestis might express its Ca2+-regulated genes in vivo.

Growth in mouse peritoneal macrophages of Yersinia pestis lacking established virulence determinants

Cultured mouse resident peritoneal macrophages were challenged with strains of Yersinia pestis differing only with respect to the absence of one or more of the virulence determinants established for the species. Guanine-auxotrophic (Pur-) yersiniae were unable to survive within the macrophages; exogenous hypoxanthine and guanosine permitted intracellular growth. This finding supports the idea that Pur- yersiniae are avirulent due to inability to obtain sufficient free purines in host tissues for growth and maintenance and indicates that net biosynthesis is necessary to counteract the intracellular microbicidal environment of macrophages. Yersiniae unable to pigment in medium containing the dye Congo red (Pgm-) or lacking either of the plasmids associated with the pesticin or calcium dependence virulence determinants (Pst- and Vwa-, respectively) were taken up as efficiently into macrophages and grew as well within these cells as did bacteria having all invasive virulence determinants intact. Opsonization with 100% homologous normal serum before infection of macrophages did not affect the ability of Pgm- or Vwa- Pgm- yersiniae to grow within macrophages. Accordingly, attributes independent of these virulence determinants mediate the survival and growth of yersiniae in serum and within resident macrophages, and components of the mammalian environment other than serum and macrophages must interact with Pgm-, Pst- and Vwa- yersiniae to cause their avirulence in vivo.

Combined application of cytodiagnostic technics to the cerebrospinal fluid

The major purpose of the examination of the cells in the cerebrospinal fluid (CSF) is the diagnosis of malignant growths. However, unequivocal tumor cell diagnosis is often problematical, since cells of local origin can also demonstrate considerable proliferative activity and great morphological variety. In these circumstances, it is advisable to evaluate cells from several points of view. One can demonstrate morphological characteristics with panoptic staining and can gain an impression of the RNA content of a cell with acridine orange (AO) fluorescent stain. Quantitative measurements of DNA synthesis in vitro can be made by labelling with tritiated thymidine. Multidimensional cytodiagnosis gives a comprehensive impression of the quality of the cells in question and provides the clinician with information which can be valuable for subsequent diagnostic and therapeutic efforts.

Multiple chromosomal associations and paracentromeric region instability in a case of acute leukemia

A case of acute myelomonocytic leukema is described, which was characterized cytogenetically by the presence of centromeric elongations, somatic crossovers, selective endoreduplication figures, and multiple chromosomal clusters. The demonstration of these phenomena by selective staining techniques for the chromosome bands (Q, C, G and S) and the nucleolar areas (acridine-orange, amido black B 10) raises some biological aspects involved in the proliferation of leukemic cells, such as nucleolar persistance during the metaphase and the non-separation of chromatids in the clusters during the anaphase. These structural abnormalities may represent the background for the explanation of the appearance of subclones in neoplastic disorders.

Inorganic Ions in Glasses and Polycrystalline Pellets as Fluorescence Standard Reference Materials

The absorption and fluorescence of inorganic glasses and polycrystalline disks doped by heavy metal ions is discussed, and their use as fluorescence standards is evaluated. The advantages of the glass standards over other media is summarized. The glass standards are divided into two groups (1) glasses doped by trivalent rare earths such as Gd³⁺, Tb³⁺, Eu³⁺, Sm³⁺, and Tm³⁺ which have narrow band optical spectra as a result of intraconfigurational transitions, and (2) glasses and polycrystalline disks doped by ions such as Tl⁺, Pb²⁺, Ce³⁺, and Cu⁺ which have broad spectral bands since the optical spectra originate from interconfigurationally allowed transitions. Optical and physical parameters, including matrix effects, quantum efficiencies, decay characteristics, Stokes' shifts and spin-orbit versus orbit-lattice interactions due to the different transitions will be discussed. Group (1) glasses are suitable for use as standards where a narrow well-defined fluorescence range is required, and group (2) glasses are suitable for use as standards whenever a substance with a wide range of fluorescence is measured. Special emphasis will be placed on energy transfer between donor and acceptor ions.

An electron microscopic study of blood and bone marrow in vitamin E-deficient pigs

The ultrastructure of blood and bone marrow cells in vitamin E-deficient pigs was studied and correlated with the light microscopic appearance. Earlier light microscopic observations indicating an inadequate erythroid production were confirmed and supplemented. Furthermore, evidence of increased destruction of erythroid cells and abnormalities in formation of myeloid cells were observed.

Isolation of metaphase chromosomes from HeLa cells

The authors have developed a method for large-scale isolation of metaphase chromosomes from HeLa cells. The distinguishing feature of this method is the use of a pH sufficiently low (about 3) to stabilize the chromosomes against mechanical damage. Many milligrams of fairly pure, morphologically intact chromosomes can be isolated in 8 hr or less of total working time. The isolated chromosomes contain about 2.0 mg of acid-soluble protein, 2.7 mg of acid-insoluble protein and 0.66 mg of RNA for each milligram of DNA. The RNA bound to the isolated chromosomes consists mainly of ribosomal RNA, but there is also a significant amount of 45S RNA.

Studies on nucleic acid metachromasy. I. The effect of certain fixatives on the dye stacking properties of nucleic acids in solution

The stacking coefficients (K's) of nucleic acids have been thought to influence the color contrast between DNA and RNA in tissue sections stained with metachromatic dyes. This idea was tested by titrating toluidine blue (TB) and acridine orange (AO) in solution against DNA and RNA, native or treated with formaldehyde, acrolein, or Carnoy's fluid. Absorption spectra at varying polymer-dye ratios were used to compute K values by the methods of Bradley and colleagues. Results with both dyes fit Bradley's stacking equations. Fixatives did not block dye-binding sites but markedly altered K values. K of DNA was low, unaffected by aldehyde fixative, increased by Carnoy's fluid or heat denaturation. K of RNA was higher than that of DNA and was increased greatly by formaldehyde, almost as much by acrolein, considerably less by Carnoy's fluid. Aldehyde effects were partially reversed upon removal of aldehyde by dialysis. These observations accord with known effects of aldehydes and denaturation upon nucleic acid conformation. Differences between K's of DNA and RNA were greater after aldehyde treatment than after Carnoy's, and were greater with AO than with TB. This is generally consistent with the magnitude of the color contrasts observed in tissues. Additional factors must contribute to the intense color contrast observed in acrolein-fixed tissues stained with TB.

Studies on nucleic acid metachromasy. II. Metachromatic and orthochromatic staining by toluidine blue of nucleic acids in tissue sections

Acrolein-fixed, polyester wax-embedded tissue sections showed excellent preservation of light microscopic architecture and, when stained with toluidine blue, intense color contrast between DNA, which stained orthochromatically, and RNA, which stained metachromatically. This method has practical value for differentiating DNA from RNA in the same section. The color contrast was impaired by substituting formaldehyde for acrolein or paraffin for polyester wax, and was negligible in tissues fixed in formaldehyde or Carnoy's fluid and embedded in paraffin. Quality of structural preservation paralleled degree of color contrast. Metachromatic staining can be analysed, by the quantitative parameters of Bradley and colleagues, to provide inferences regarding the conformation of biopolymers in tissue sections. Comparison of the nucleic acid color contrasts in toluidine blue-stained sections with titrations of fixative-treated nucleic acids against toluidine blue in solution indicated a greater difference in conformation between DNA- and RNA-protein in acrolein-polyester sections than between acrolein-treated free DNA and RNA in solution. This is supported by recent evidence that the conformation of ribosomal RNA is quite different in whole ribosomes from that assumed by the same RNA free in solution. The acrolein-polyester method may enhance color contrast by providing superior preservation of ordered nucleoprotein conformations.