P. B. Gahan

Circulating Nucleic Acids in Plasma and Serum

DNA and RNA fractions have been isolated from the whole blood, serum, plasma, the surface of blood cells, and urine of both healthy individuals and patients. The ability to isolate, quantify, and analyze these molecules has led to the identification of specific nucleic acid fragments related to particular disorders such as diabetes, cancer, myocardial infarction, and stroke, threby permitting their early diagnosis. Currently, a number of methods for isolating the nucleic acids are employed and although a start has been made to compare the efficiencies of these methods, there is still a way to go before there are precise protocols for nucleic acid extraction. The older chemical methods of extraction still outperform some of the available kits. Some progress is being made to determine the origin of the circulating nucleic acids, although there are still many questions to be answered, including whether the source is through the spontaneous release of newly synthesized nucleic acid or whether it just derived from necrotic and apoptotic cells. In addition, it can be demonstrated that the nucleic acids can enter cells and exhibit a biological activity in the recipient cells. Hence, the question remains: Are the circulating nucleic acids freely entering tissues and cells from the blood and inducing changes in those tissues and cells? Further work is needed to elucidate these areas, and the various protocols must be standardized if the new methodology is to be widely and accurately applied in the diagnosis of disease and the monitoring of therapy. This chapter summarizes the work reported in this volume.

The virtosome—a novel cytosolic informative entity and intercellular messenger

Studies on a range of prokaryote and eukaryote cells and tissues have shown that a newly synthesized DNA/RNA–lipoprotein complex is released in a regulated manner. This complex, termed a virtosome, is a novel cytosolic component of eukaryote cells. The released virtosomes can readily enter other cells where they can modify the biology of the recipient cells. Such modifications include immunological changes and transformation from normal to cancer cells. The virtosomes form a normal component of the circulating nucleic acids in plasma and serum currently used for clinical diagnostic purposes. Given the transformative powers of virtosomes released from tumour cells, the presence of such a complex in human plasma could readily offer the basis of an alternative mechanism for the initiation of metastases. Copyright

Metabolic DNA as the Origin of Spontaneously Released DNA

A DNA fraction is spontaneously released from living, but not dead or dying, human, other mammalian, avian, amphibian, plant, and prokaryote cells. The spontaneously released DNA fraction has been shown to be (a) present in both actively dividing and nondividing, differentiated cell populations; (b) labile; (c) associated with DNA‐dependent RNA or DNA polymerase; (d) associated with an RNA fraction; and to have (e) a lower molecular weight than the typical genetic DNA fraction; and (f) Alu repeat sequences in increased proportions compared to a unique gene in plasma/serum. On the other hand, early autoradiographic and biochemical and quantitative cytochemical and cytophysical studies on DNA permitted the identification of a DNA fraction which was (1) present in both actively dividing and nondividing, differentiated cell populations; (2) labile; and (3) had a lower molecular weight than the typical genetic DNA fraction. This DNA fraction was termed metabolic DNA (m‐DNA) and was proposed as possibly forming extra gene copies for the rapid production of m‐RNA, to be destroyed subsequently. Therefore, we suggest that the metabolic DNA fraction might represent the precursor to the formation of the spontaneously released DNA fraction.

In vitro stimulation by tumour cell media of [3H]-thymidine incorporation by mouse spleen lymphocytes

Mouse spleen lymphocyte (SL) cells show a three to four‐fold increase in [3H]‐thymidine incorporation when incubated in tumour cell media, or in media containing tumour cell cytosol. Agarose gel chromatography of both [3H]‐thymidine‐labelled tumour cell media and cytosol shows a sharp peak of DNA‐associated material eluting at about 60 kDa. This DNA‐associated material is imported rapidly and efficiently by SL cells and is recoverable from their cytosol. The stimulating effect on SL cell thymidine incorporation resides primarily, if not exclusively, in this extruded/cytosolic 60 kDa DNA material. Tumour cells incubated in media containing normal or liver, but not tumour, cytosol show a reduced rate of [3H]‐thymidine incorporation, indicating competition between normal and tumour associated DNA complexes. The results indicate that such cell‐extruded DNA complexes may transmit ‘genetic messages’ to other cells, and are discussed in terms of interactions in the tumour‐bearing host.

TEM cytochemical study of the localization of phospholipids in interphase chromatin in rat hepatocytes

SummaryThe electron microscopy cytochemical detection of phospholipids in well-defined areas in the interphase nuclei of hepatocytes has been obtained by the acid haematein test, modified for electron microscopy and by the phospholipase A2-colloidal gold method. The specificity of both methods were controlled by enzymatic digestion with phospholipase. The main intra-nuclear localization of phospholipids is at the border between the condensed and dispersed chromatin, where non-ribosomal RNA is also revealed by RNase-gold labelling. Phospholipids are detected, too, over the clusters of interchromatin granules and in the fibrillar component of the nucleolus.

Overview of healthcare in the UK

The National Health System in the UK has evolved to become one of the largest healthcare systems in the world. At the time of writing of this review (August 2010) the UK government in its 2010 White Paper “Equity and excellence: Liberating the NHS” has announced a strategy on how it will “create a more responsive, patient-centred NHS which achieves outcomes that are among the best in the world”. This review article presents an overview of the UK healthcare system as it currently stands, with emphasis on Predictive, Preventive and Personalised Medicine elements. It aims to serve as the basis for future EPMA articles to expand on and present the changes that will be implemented within the NHS in the forthcoming months.

Agrobacterium tumefaciens RNA in non-tumorous tomato cells

Abstract Agrobacterium tumefaciens , strain B6 (virulent), RNA has been found in non-tumorous tomato cells after the plants have been dipped in a bacterial suspension. The percentage of in vitro hybridization between the A. tumefaciens DNA and the RNA extracted from plants dipped in the bacterial suspension is higher than between this DNA and the RNA from bacteria grown in culture.

Circulating nucleic acids in plasma and serum: diagnosis and prognosis in cancer

The presence of DNA and RNA circulating in human plasma and serum is described. The known sources of the DNA/RNA in blood, the ability of these nucleic acids to enter other cells and to express in the recipient cells are considered along with their relationship to metastases. The possible role(s) of the DNA/RNA in personalized clinical diagnosis, monitoring of treatment and prognosis in oncology are discussed.

Glucose‐6‐Phosphate and UDP‐D‐Glucose Dehydrogenases: Possible Markers of Vascular Differentiation

A quantitative cytochemical study of intact root apices and wounded roots of Pisum sativum, and of cotyledons from Solanum aviculare induced to form vessels from mesophyll cells, has demonstrated a sharp increase in glucose-6-phosphate dehydrogenase activity at a very early stage in the differentiation of the vascular tissues. However, UDP-D-glucose dehydrogenase activity appears to increase only at a time corresponding to the initiation of secondary cell wall events. Data from the callus cultures from Malus M27 and Cox endosperm indicated that glucose-6-phosphate dehydrogenase activity changes may be a possible marker for determining between the regenerability and recalcitrance of calluses.

Biotechnology worldwide and the 'European Biotechnology Thematic Network' Association (EBTNA)

The European Biotechnology Congress 2011 held under the auspices of the European Biotechnology Thematic Network Association (EBTNA) in conjunction with the Turkish Medical Genetics Association brings together a broad spectrum of biotechnologists from around the world. The subsequent abstracts indicate the manner in which biotechnology has permeated all aspects of research from the basic sciences through to small and medium enterprises and major industries. The brief statements before the presentation of the abstracts aim to introduce not only Biotechnology in general and its importance around the world, but also the European Biotechnology Thematic Network Association and its aims especially within the framework of education and ethics in biotechnology.