Showing papers by "University of London published in 1973"
TL;DR: Visibly normal specimens from the superficial layer which were situated adjacent to visibly degenerate cartilage were weaker and less stiff than specimens situated on normal joints or remote from visibly degenerated cartilage.
455 citations
TL;DR: Vigorous exercise apparently protected against rapidly fatal heart attacks and other first clinical attacks of coronary disease alike, throughout middle age, according to a hypothesis that vigorous exercise promotes cardiovascular health.
431 citations
TL;DR: A modification has been developed for the method of calculating the rate of protein synthesis in individual tissues from the specific radioactivity of the free and protein-bound amino acid in tissue at the end of the infusion, which gives greater accuracy and allows a greater choice of labelled amino acids.
Abstract: 1. The rate of protein synthesis in rat tissues was measured by constant intravenous infusion of [14C]tyrosine. A modification has been developed for the method of calculating the rate of protein synthesis in individual tissues from the specific radioactivity of the free and protein-bound amino acid in tissue at the end of the infusion. This technique gives greater accuracy and allows a greater choice of labelled amino acids. The specific radioactivity of free tyrosine in plasma was used to calculate the plasma tyrosine flux, an index of the rate of protein synthesis in the whole body. 2. Young male Wistar rats were allowed access to food for only 4h in every 24h. The tyrosine flux and the rate of protein synthesis in liver and muscle at different periods of time after a single feed were estimated. 3. The tyrosine flux did not alter after feeding nor even after starvation for 48h. 4. The average fractional rate of protein synthesis in muscle was 7.2%/day, i.e. the proportion of the protein mass which is replaced each day. The rate rose after eating and declined during starvation for 48h. In addition the rate of muscle protein synthesis correlated with the growth rate of the rat. 5. In liver the average fractional rate of protein synthesis was 50%/day. There was no change in the rate after eating nor after starvation for 48h. In contrast with muscle this suggests that the changes in protein mass were accompanied by changes in the rate of protein breakdown rather than synthesis.
382 citations
TL;DR: In this article, the authors focus on recent criticisms of the study of the role of life-events in the onset of psychiatric conditions and suggest that measurement error and bias can be reasonably well controlled by various methodological procedures.
Abstract: The paper focuses on recent criticisms of the study of the role of life-events in the onset of psychiatric conditions and suggests that measurement error and bias can be reasonably well controlled by various methodological procedures. Failure to comply with these may be expected, however, to increase rather than decrease the chances of establishing a ‘positive’ resuit. Three further factors to do with the design of studies and the analysis of data are discussed which are likely to mask real differences between patient and comparison group, and which therefore might explain the ‘negative’ results reported in the literature. They concern: (1) the choice of an appropriate comparison group; (2) specification of the length of the period between event and onset; and (3) specification of the event in terms of some measure of severity. Results from two London studies of schizophrenic and depressive patients are presented to illustrate the argument. The studies suggest that life-events do play an important causal role in bringing about both disorders.
322 citations
TL;DR: One possible event of the process ν − μ+ e − → v − μ + e − has been observed in this article, and the event is interpreted in terms of the Weinberg theory.
311 citations
TL;DR: Recent experimental work on rat liver is discussed which is considered to indicate that a primary function of vitamin E in vivo may be to inhibit the oxidation of selenide‐containing proteins present in mitochondria and in smooth endoplasmic reticulum.
309 citations
TL;DR: It is concluded that the expected weight of a child of given height is independent of age and largely independent of race.
278 citations
TL;DR: In this article, the proportion involved in the causal link between life-events and psychiatric disorders was measured and the nature of the causal effect itself was examined. But the results were limited to depression and schizophrenia.
Abstract: Methods are first described for testing for and measuring the proportion involved in the causal link between life-events and psychiatric disorders; the paper then deals with the nature of the causal effect itself. A method is described (and developed mathematically in an appendix) which enables a choice to be made between a triggering effect in which events are seen as precipitating an illness that would probably have occurred before long for other reasons, and a formative effect in which life-events either substantially advance onset in time, or bring it about altogether. The method is used to demonstrate the presence of a formative effect in depressive and a triggering effect in schizophrenic disorders.
249 citations
TL;DR: The term ‘fusogenic’ is proposed to describe chemical, viral and physical agents that cause membranes to fuse and the possible biological significance of membrane fusion by fusogenic lipids is discussed.
Abstract: 1. The ability of a number of carboxylic acids, their esters, retinol and alpha-tocopherol to induce fusion of hen erythrocytes in vitro was investigated. 2. Some 30 different fat-soluble substances (100mug/ml) were found to cause the formation of multinucleated erythrocytes with a suspension of 3x10(8) erythrocytes/ml. The most effective agents induced fusion within 5-10min at 37 degrees C; some substances required about 1h. 3. Inclusion of Dextran 60C in the test medium minimized colloid osmotic lysis caused by exogenous lipids that induce cell fusion. 4. Cell swelling, followed by cell adhesion, was then seen to precede cell fusion. 5. Fusion occurred with C(10)-C(14) saturated carboxylic acids, with unsaturated, longer-chain carboxylic acids and their mono-esters; retinol, and to a lesser extent alpha-tocopherol, also caused cell fusion. 6. C(6)-C(9), C(15), C(16) and C(18) saturated carboxylic acids did not induce fusion within 4h; glyceryl dioleate was only weakly active, and glyceryl trioleate was inactive in the test system. 7. Fusion was facilitated by a high ratio of chemical agents to cell number and by incubation between pH5 and 6. It was inhibited by EDTA and by serum albumin. 8. Glyceryl mono-oleate caused both a similar fusion of several species of mammalian erythrocyte and the interspecific fusion of human and chicken erythrocytes. 9. The term ;fusogenic' is proposed to describe chemical, viral and physical agents that cause membranes to fuse. 10. The biochemical mechanisms involved and the possible biological significance of membrane fusion by fusogenic lipids are discussed.
247 citations
TL;DR: In this article, a simplified model of the drop growth process during condensation was used to predict the average distribution of drop sizes, and the theoretical distribution was compared with measurements [8, 31], a recent computer simulation [32] and an earlier empirical distribution.
226 citations
TL;DR: This paper presents a method for predicting how much change can be expected from regression, and thus a means of estimating the treatment effect, based on measures of within-person and between-person variability.
TL;DR: The trend toward earlier maturation in children, as evidenced by age at menarche, has stopped, at least for the present, Brundtland and Walløe1 have reported.
Abstract: Brundtland and Walloe1 have reported that the trend toward earlier maturation in children, as evidenced by age at menarche, has stopped, at least for the present. Using probit estimates in a status quo inquiry they gave the mean ages as 13.27 yr in 1952 and 13.24 in 1970. Both results were based on large samples of Oslo schoolgirls.
TL;DR: From genetic evidence, it is concluded that, together, these two dsRNAs determine the cytoplasmically inherited killer character.
Abstract: Two high molecular weight dsRNA species have been found in yeast and strains have been found which possess either the larger, or both, of these molecules. From genetic evidence, we conclude that, together, these two dsRNAs determine the cytoplasmically inherited killer character.
TL;DR: A mechanism for the control of blood flow to suit the respiratory requirements of the fish is suggested, which involves a system of recruitment of additional respiratory units and changes in overall blood flow patterns.
Abstract: A light and electron microscopic study was made of the structure of the gill arch, filament and secondary lamella of Salmo gairdneri R. Blood pathways through the gill were traced from serial histological sections, and from the examination of ink perfused tissue and perspex casts formed following resin injection of the circulatory system.
TL;DR: It is suggested that the prime function of persistent advertising song in the unpaired male is sexual attraction of the female, and that intermittent advertising song from paired males functions in territorial defence.
Abstract: The possible functions of male advertising song in the Sedge Warbler (Acrocephalus schoenobaenus) and the Reed Warbler (A. scirpaccus) were studied using both observational and experimental techniques in the field. The seasonal rhythms of advertising song in the populations over three years were found to be species-specific, and were related to male arrival, female arrival and pairing. Population song was also related to population breeding acivity as revealed by the seasonal pattern of egg-laying. When population song was more synchronised, population breeding activiy was more synchronised towards the start of the breeding season. The diurnal rhythms of advertising song in individual marked males were monitored before and after pairing. In Sedge Warbler males advertising song ceased completely after pairing, and only resumed if the female deserted. In Reed Warbler males, a vestige of the former diurnal rhythm remained after pairing, with groups of paired males performing dawn and dusk choruses of 'social song'. The interspecific differences were extended further, as both observations and play-back experiments confirmed that paired male Sedge Warblers did not utilise advertising song in territorial interactions, but performed visual 'threat' displays instead. Male Reed Warblers however utilised advertising song in territorial interactions both before and after pairing. A functional interpretation of advertising song is presented, based upon the observational and experimental evidence collected. It is suggested that the prime function of persistent advertising song in the unpaired male is sexual attraction of the female, and that intermittent advertising song from paired males functions in territorial defence. The precise function(s) of social song in paired males are not known, but some suggestions are discussed. The interspecific differences in the functional spectra of advertising song found in the Reed Warbler (sexual, territorial, social) and Sedge Warbler (sexual only,) are discussed in relation to habitat and social organisation. The Reed Warbler inhabits more dense, non-visual habitats, and the Sedge Warbler more open, visual ones. Thus the Sedge Warbler has developed comparatively more visual forms of advertisement, and the Reed Warbler more vocal forms which in the latter case is reflected particularly in the wider functional spectrum of advertising song. The only common function for which advertising song is utilised in both species is sexual attraction of the female. This, and other evidence discussed suggests that sexual attraction may be the most important and perhaps the most primitive function of advertising song in these species.
TL;DR: Clearance per unit acid secretion increased during prostaglandin administration, precluding a primary reduction in mucosal blood flow as the mechanism of the antisecretory action.
Abstract: 1 The effects of prostaglandins E1, E2, A1 and A2 on gastric acid secretion and mucosal blood flow were studied by means of a [14C]-aniline clearance technique in the anaesthetized rat
2 During intravenous administration of these prostaglandins, in doses which almost completely inhibited pentagastrin- and histamine-induced acid secretion, a fall in clearance was observed
3 Clearance per unit acid secretion increased during prostaglandin administration, precluding a primary reduction in mucosal blood flow as the mechanism of the antisecretory action
4 Prostaglandins increased clearance during basal secretion, indicating a direct vasodilator effect on the gastric mucosa
5 The possibility that endogenous prostaglandins contribute to functional vasodilatation in the gastric mucosa and that exogenous prostaglandins may be of clinical value in the treatment of peptic ulcer is discussed
TL;DR: Significant differences in skin conductance responses of schizophrenics with and without orienting responses to tones without attentional significance are interpreted as evidence that schizophrenic responding and non-responding is not a function of frontal lobe involvement.
TL;DR: The findings strongly support the concept that the endocochlear potential has two components, a positive secretion potential and a negative potassium diffusion potential, and probably causes transient inhibition of the strial enzymes and then abnormalities in membrane permeability.
Abstract: The normal endocochlear potential was rapidly replaced by a negative anoxic-type potential after ethacrynic acid administration (60 mg/kg) in the rat. Recovery at first proceeded quickly but became very much slower at 30 min. However, the endolym-phatic chemical composition remained unaltered until 35 min, when progressive increase in the sodium and decrease in the potassium concentrations occurred, followed at 1 hour by a gradual return towards normal. Thus the drug probably causes transient inhibition of the strial enzymes and then abnormalities in membrane permeability. The characteristic accumulation of inter-cellular fluid in the stria vascularis was associated with and seemed to arise from these permeability changes. In addition, the findings strongly support the concept that the endocochlear potential has two components, a positive secretion potential and a negative potassium diffusion potential.
TL;DR: The use of virus-infected tissue as a source of new phytoalexins, the role of these compounds in disease resistance and their possible importance in explaining virus-induced resistance to fungal pathogens are discussed.
Abstract: Etiolated bean hypocotyls underwent necrosis and cellular browning following infection by tobacco necrosis virus. This was accompanied by the production of many phenolic compounds, some of which were shown to be highly antifungal in assays of fungal growth on thin-layer plates. Four compounds, phaseollin, phaseollidin, phaseollinisoflavan and kievitone, were isolated and identified. Their minimum lethal doses towards spore germination of Colletotrichum lindemuthianum were 2, 2, 2 and 20 μg/ml respectively. In addition, following their isolation in high yield from virus-infected tissue, they were also demonstrated in tissue infected with C. lindemuthianum. They have thus been referred to as phytoalexins. The use of virus-infected tissue as a source of new phytoalexins, the role of these compounds in disease resistance and their possible importance in explaining virus-induced resistance to fungal pathogens are discussed.
TL;DR: Clinical and biochemical measurements are compared in middle-aged male Civil Servants, 244 living in six hard-water and 245 in six soft-water towns to observe differences in blood-pressure, plasmacholesterol, and heart-rate levels that could be important in explaining a substantial part of the difference in cardiovascular mortality.
TL;DR: Evidence indicates an average loss of a quarter of the relative secretory cell volume between childhood and old age, by which time the more extremely affected glands may have lost one half.
Abstract: . The ratio of functional parenchymal (acinar and duct) cells to intracapsular fat and connective tissue in human submandibular salivary glands is seen microscopically to differ from subject to subject. In the present analysis of an apparently age-related change, a modification of the random-point counting method of Chalkley (1943) of determining the relative volumes of tissue constituents from histological sections was applied to the submandibular glands of a randomly chosen sample of 36 subjects (six from each decade of age from 25–84 years) from a series of 211 consecutive autopsies. Reproducibility tests of the method of measurement and also observations on a further group of 19 healthy control subjects who had died “sudden” deaths, were made. When the values for the volume, of functional mass of acinar and duct cells relative lo that of fat and connective tissue were analyzed in relation to age, a gradual significant reduction through adult life was found (regression coefficient b =–0.28, p < 0.01). Moreover, the values for a further group 5–14 years of age fell close to the extrapolated regression line of the groups aged from 25 to 84 years old. The trend for reduction may therefore begin in childhood. Analysis did not indicate that either fat or connective tissue alone predominated in the replacement of secretory cells. The values were not related to the adiposity of (he subject, and no trend for change with age was found in the fresh wet weights of 60 glands from subjects aged 25–74 years. The evidence indicates an average loss of a quarter of the relative secretory cell volume between childhood and old age, by which time the more extremely affected glands may have lost one half.
TL;DR: This paper is a clinical and radiologic study of 71 children with craniopharyngioma aimed at establishing the incidence of the various manifestations of the tumor in children.
TL;DR: On décrit une méthode pour l'établissement d'une culture de cellules du crapaud a griffes sudafricain, Xenopus laevis, afin de l'infecter avec des arbovirus.
Abstract: On decrit une methode pour l'etablissement d'une culture de cellules du crapaud a griffes sudafricain,Xenopus laevis, afin de l'infecter avec des arbovirus. Les cellules (XTC-2) ont subi une culture continue pendant 3 ans. Elles ont un nombre diploide de chromosomes. Elles furent cultivees aux temperatures de 22°C et de 28°C dans un milieu de culture dilue de NCTC 109 avec 10% de serum de veau foetal.
TL;DR: A high frequency of Australia antigen and its antibody was found in patients attending a clinic for sexually transmitted diseases and analysis of the case-reports indicated that there were two distinct populations.
TL;DR: In this paper, heat transfer measurements for film condensation of steam on a vertical plane surface in the presence of air, argon, neon and helium, under free-convection conditions are reported.
TL;DR: Analysis of 500,000 C. nemoralis snails from throughout Europe shows that there is a strong positive association between gene frequencies at the shell color locus and mean summer temperature, but that no climatic correlations are obvious at other loci.
Abstract: Polymorphic snails of the genus Cepaea have been widely used for research in ecological genetics. Natural selection by selective predation is important in controlling morph frequencies in some populations of C. nemoralis in England. The importance of environmental selection in affecting other patterns of local genetic differentiation of population structure (area effects) is a matter of controversy. Some authors emphasize divergent evolution of whole gene pools between area effects, while others feel that climatic selection acting on individual loci is important. Analysis of 500,000 C. nemoralis snails from throughout Europe shows that there is a strong positive association between gene frequencies at the shell color locus and mean summer temperature, but that no climatic correlations are obvious at other loci. Another species, C. vindobonensis, which has a much simpler system of polymorphism than does C. nemoralis, was investigated in Yugoslavia, in a region where there is known to be intense microclimatic differentiation because of the accumulation of cold air in frost hollows. There was a striking tendency for snails with lightly pigmented shell bands to be found in places with a warm microclimate. Physiological and behavioral experiments demonstrate that this is due primarily to differential energy absorption from sunshine by the different shell phenotypes. As in C. nemoralis, other C. vindobonensis phenotypes show no detectable association with the environment. It is possible that genes whose frequencies cannot be related to environmental selection may have evolved strong linkage interactions with other genes in the population9s gene pool. Selection by the ecological environment and the genetic environment may therefore both be important in controlling the genetic structure of snail populations.
TL;DR: A concept is developed which suggests that all basic amines (group I) are oxidised by a flavine adenine nucleotide (FAD)-dependent enzyme system, whereas non-basic nitrogen-containing compounds (group III) are oxidation by a cytochrome P450-dependent system.
TL;DR: The results are consistent with the hypothesis that ascorbate stimulates O2 uptake by reduction of superoxide, which is formed by autoxidation of the added electron acceptor (MV), and which dismutates in the absence of asCorbate.