The chemical constitution of viruses

Contributions of vibrational spectroscopy to virology: A review

Vibrational spectroscopic techniques, both infrared absorption and Raman scattering, are high precision, label free analytical techniques which have found applications in fields as diverse as analytical chemistry, pharmacology, forensics and archeometrics and, in recent times, have attracted increasing attention for biomedical applications. As analytical techniques, they have been applied to the characterisation of viruses as early as the 1970 s, and, in the context of the coronavirus disease 2019 (COVID-19) pandemic, have been explored in response to the World Health Organisation as novel methodologies to aid in the global efforts to implement and improve rapid screening of viral infection. This review considers the history of the application of vibrational spectroscopic techniques to the characterisation of the morphology and chemical compositions of viruses, their attachment to, uptake by and replication in cells, and their potential for the detection of viruses in population screening, and in infection response monitoring applications. Particular consideration is devoted to recent efforts in the detection of severe acute respiratory syndrome coronavirus 2, and monitoring COVID-19.

Tobacco Mosaic Virus and the History of Molecular Biology

The history of tobacco mosaic virus (TMV) includes many firsts in science, beginning with its being the first virus identified. This review offers an overview of a history of research on TMV, with an emphasis on its close connections to the emergence and development of molecular biology. Expected final online publication date for the Annual Review of Virology, Volume 9 is September 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Covid-19 pandemic and the unprecedented mobilisation of scholarly efforts prompted by a health crisis: Scientometric comparisons across SARS, MERS and 2019-nCoV literature

During the current century, each major coronavirus outbreak has triggered a quick and immediate surge of academic publications on its respective topic. The spike in research publications following the 2019 Novel Coronavirus (Covid-19) outbreak, however, has been like no other. The global crisis caused by the Covid-19 pandemic has mobilised scientific efforts at an unprecedented scale. In less than 5 months, more than 12,000 research items and in less than seven months, more than 30,000 items were indexed, while it is projected that the number could exceed 80,000 by the end of 2020, should the current trend continues. With the health crisis affecting all aspects of life, research on Covid-19 seems to have become a focal point of interest across many academic disciplines. Here, scientometric aspects of the Covid-19 literature are analysed and contrasted with those of the two previous major coronavirus diseases, i.e., Severe Acute Respiratory Syndrome (SARS) and Middle East Respiratory Syndrome (MERS). The focus is on the co-occurrence of key-terms, bibliographic coupling and citation relations of journals and collaborations between countries. Interesting recurring patterns across all three literatures were discovered. All three outbreaks have commonly generated three distinct cohorts of studies: (i) studies linked to public health response and epidemic control, (ii) studies on chemical constitution of the virus; and (iii) studies related to treatment, vaccine and clinical care. While studies affiliated with category (i) seem to have been relatively earliest to emerge, they have overall received relatively smaller number of citations compared to publications the two other categories. Covid-19 studies seem to have been disseminated across a broader variety of journals and across a more diverse range of subject areas. Clear links are observed between the geographical origins of each outbreak as well as the local geographical severity of each outbreak and the magnitude of research originated from regions. Covid-19 studies also display the involvement of authors from a broader variety of countries compared to SARS and MERS. Considering the speed at which the Covid-19-related literature is accumulating, an interesting dimension that warrants further exploration could be to assess if the quality and rigour of these publications have been affected.

A correlative study by electron and light microscopy of the development of type 5 adenovirus. II. Light microscopy

The evolution of the intranuclear lesion produced by type 5 adenovirus in HEp-2 and HeLa cells is described as seen in the light microscope and the bodies formed in the course of the infection characterized histochemically. Some 12 hours after infection acidophilic protein bodies, without appreciable nucleic acid, first appear in the nucleus and coalesce into a network. Within or in association with this material, DNA-containing masses (viral aggregates) are formed which rapidly increase in amount and then coalesce. At the same time, a protein is produced, histochemically different from that of the acidophilic or basophilic structures mentioned, within the infected nucleus, which constitutes a matrix within which regular cytstals of a protein, (presumably non-viral) materialize. These structural and histochemical features are correlated with details which have been observed in parallel studies with the electron microscope.

Reexamination of the association between melting point, buoyant density, and chemical base composition of deoxyribonucleic acid

The equations currently used for the calculation of the chemical base composition of deoxyribonucleic acid (DNA), expressed as moles per cent guanine plus cytosine (% GC), from either buoyant density (rho) or midpoint of thermal denaturation (T(m)) were recalculated by using only sets of data on DNA determined with the same strains. All available information from the literature was screened and supplemented by unpublished data. The results were calculated by regression and correlation analysis and treated statistically. From the data on 96 strains of bacteria, it was calculated that% GC = 2.44 (T(m) - 69.4). T(m) appears to be unaffected by the substitution of cytosine by hydroxymethylcytosine. This equation is also valid for nonbacterial DNA. From the data on 84 strains of bacteria, the relation% GC = 1038.47 (-1.6616) was calculated. The constants in this equation are slightly modified when data on nonbacterial DNA are included. Both correlations differ only slightly from those currently used, but now they lean on a statistically sound basis. As a control, the relation between rho and T(m) was calculated from data of 197 strains; it agrees excellently with the above two equations.

A cytological and cytochemical investigation of the development of the viral papilloma of human skin

The morphological appearances and some tinctorial properties of the cells of the infectious (viral) papilloma of human skin are described. Pathological alterations of the nuclei of affected cells occur in a definite sequence of stages. In the earliest, and acidophilic Feulgen-negative intranuclear inclusion body is recognizable. Subsequently the inclusion body and nucleus enlarge, there is progressive disorganization of nuclear structure, and the inclusion body then becomes basophilic and stains with the Feulgen reaction. The nucleus finally disappears, leaving the inclusion body in the cell remnant. The relative amounts of Feulgen-colored DNA per cell at each stage in the evolution of the lesion in the infected cells, as well as in normal appearing and hypertrophic cells of the papilloma, were measured microphotometrically in Feulgen preparations. Determinations were made using the "plug" and "two wave length" methods. These are compared with measurements of DNA in cells of the basal and spinous layers of normal human skin. The frequency distribution curves of relative amount of DNA in cells of normal skin, and normal-appearing cells in hyperplastic epithelium, show the bimodal diploid and tetraploid peaks characteristic of growing tissues. Infection of the epidermal cell entails prompt synthesis of DNA in the nucleus. Increased amounts of DNA (tetraploid to 16 ploid levels) are found in the earliest recognizable cytopathological stages of infection and do not increase appreciably during the subsequent evolution of the cellular lesion. At a relatively late stage, all the cellular DNA is relocated ("transferred" or "reassembled") in the inclusion body, and is not further significantly increased in amount. Active formation of DNA in affected cells appears, from these measurements, to occur only in relatively intact nuclei. The inclusion bodies of infected cells are found to contain a relatively basic protein which stains with the alkaline-fast green method for histone.