Showing papers by "University of Glasgow published in 1975"

Fusion of host cell secondary lysosomes with the parasitophorous vacuoles of Leishmania mexicana-infected macrophages.

Abstract: Secondary lysosomes of cultured mouse peritoneal macrophages were labeled with the electron-dense colloid saccharated iron oxide; the identity of the labeled structures was checked by the Gomori reaction for acid phosphatase. Amastigotes of Leishmania mexicana mexicana derived from mouse lesions were used to infect these macrophages in vitro. In electron micrographs of thin sections of infected macrophages the labeled secondary lysosomes were seen fused with the parasitophorous vacuoles without preventing subsequent multiplication of the parasites. A similar fusion probably occurs in vivo, and may provide a pathway through which not only nutrients but also drugs and host antibodies could reach the intracellular parasite.

Goodness of prediction fit

Abstract: SUMMARY Fitting a parametric model or estimating a parametric density function plays an important role in a number of statistical applications. Two widely-used methods, one replacing the unknown parameter by an efficient estimate and so termed estimative and the other using a mixture of the possible density functions and commonly termed predictive, are compared. On a general criterion of closeness of fit based on a discriminating information measure the predictive method is shown to be preferable. Explicit measures of the relative closeness of predictive and estimative fits are obtained for gamma and multinormal models.

Effects of decreasing arterial blood pressure on cerebral blood flow in the baboon. Influence of the sympathetic nervous system.

Abstract: The influence of the sympathetic nervous system on the cerebral circulatory response to graded reductions in mean arterial blood pressure was studied in anesthetized baboons. Cerebral blood flow was measured by the 133Xe clearance method, and arterial blood pressure was decreased by controlled hemorrhage. In normal baboons, the constancy of cerebral blood flow was maintained until mean arterial blood pressure was approximately 65% of the base-line value; thereafter, cerebral blood flow decreased when arterial blood pressure was reduced. Superior cervical sympathectomy of 2-3 weeks duration did not affect the normal response. In contrast, both acute surgical sympathectomy (cervical trunk division) and alpha-receptor blockade (1.5 mg/kg of phenoxybenzamine) enhanced the maintenance of cerebral blood flow in the face of hemorrhagic hypotension in that cerebral blood flow did not decrease until mean arterial blood pressure was approximately 35% of the base-line value. The results indicate that the sympathetic nervous system is not involved in the maintenance of cerebral blood flow in the face of a fall in arterial blood pressure. Indeed, the implication is that the sympathicoadrenal discharge accompanying hemorrhagic hypotension is detrimental to, rather than responsible for, cerebral autoregulation.

Epilepsy After Non-missile Head Injuries

Abstract: Epilepsy after Non-missile Head Injuries , Epilepsy after Non-missile Head Injuries , کتابخانه مرکزی دانشگاه علوم پزشکی تهران

External Control and Regional Development: The Case of Scotland:

Abstract: The purpose of the paper is to examine some recent evidence on the degree and type of external ownership and control that exists in the manufacturing sector of the Scottish economy. Definitions of external control are discussed, and its incidence in Scotland is shown to vary widely between industrial sectors; between different sizes of manufacturing enterprise; between different types of enterprise organisation; and between the different subregions of Scotland. The theoretical and policy implications of the Scottish situation, where nearly 60 per cent of the ownership and control of manufacturing employment lies in other regions of the United Kingdom and overseas, are discussed, and areas for future research outlined. It is argued that this factor is one of vital importance for the understanding of the processes and constraints of regional economic development, and that its neglect has contributed to much of the dissatisfaction expressed about the achievements of postwar British regional development-polic...

The feeding strategies of two freshwater gastropods, Ancylus fluviatilis Müll. and Planorbis contortus Linn. (Pulmonata), in terms of ingestion rates and absorption efficiencies.

Abstract: Radiotracer and gravimetric techniques were used to investigate the effects of starvation, temperature, body size and food quality on both the ingestion rates and absorption efficiencies of A. fluviatilis (an algal grazer) and P. contortus (a detrivore which utilises the bacterial fraction of its food). In the face of food supply disturbance snails showed a considerable potential for adaptation. Both intestion rates and absorption efficiencies increased with starvation, and ingestion rate increased with reductions in food quality. Absorption efficiencies were independent of temperature and Q10 values for absorption rates suggested that snails showed some acclimation to temperature disturbance. Food absorption was linearly related to body surface area but absorption efficiencies were to a large extent independent of age and size.

The Lions of Dagbon: Political Change in Northern Ghana

Abstract: The political conflict that has taken the most violent form and proved costliest in human lives in Ghana in the last half century has been a chieftaincy dispute in the northern kingdom of Dagomba, known as the Yendi skin dispute. The major loss of life took puce in 1969 but the dispute has continued to trouble Ghanaian politics and has affected the careers of national leaders under both civilian and military regimes. It is one of the most complex, explosive and intractable disputes in a country noted for conflicts over chieftaincy. Mr Staniland examines the political history of Dagomba, one of the most important pre-colonial states in what is now Ghana, from its partition between the British and the Germans in 1899. He analyses the attitudes and policies of successive governments towards chieftaincy and `traditionalism', and the effects which outside control has had on dynastic politics.

The nature and origin of the soluble protein in human amniotic fluid

Abstract: Summary 1. Amniotic fluid surrounds the human fetus and is separated from the uterus by the amnion, chorion and placenta. The ability to obtain samples of amniotic fluid from women by a simple procedure has encouraged studies on the nature and origin of the fluid, and on its use for the diagnosis of a variety of clinical conditions. The fluid contains cells, which are of fetal origin, and can be grown in a tissue culture. Cyto-genetic and biochemical analyses can therefore be used to detect chromosomal aberrations and inborn errors of metabolism in the fetus. 2. The supernatant of amniotic fluid contains many of the solutes typical of extracellular fluid. In particular, it contains a wide range of proteins and those which are of fetal origin are likely to be of use in the prenatal diagnosis of fetal disease. This review examines the nature and origin of the soluble protein in amniotic fluid, and discusses the diagnostic uses of the proteins which are of fetal origin. 3. In other mammals, the arrangement of the fetal membranes is different from that in man, and these differences are reflected by changes in the nature of the amniotic fluid. Thus data from other animals have little applicability to man. 4. Electrophoresis and immunoelectrophoresis have established that the major proteins in amniotic fluid are also present in maternal and fetal sera. Their concentrations in the fluid are influenced by their molecular weight and proteins larger than about 2.5 times 106 may be excluded. Towards term, phenotyping studies show that a number of serum proteins in amniotic fluid are of maternal origin. In the case of group-specific component (Gc) this has been shown to be so throughout pregnancy. Such proteins must enter the fluid by diffusing across either the chorion or the chorionic plate and then the amnion. 5. It has been previously claimed that various serum proteins in amniotic fluid are of fetal origin. For albumin and IgG there are data that strongly support a maternal origin. The evidence on the origin of insulin is inconclusive. The concentration of β2-microglobulin in amniotic fluid exceeds that in maternal serum and is probably too high also for fetal serum to be its major source. It has a wide tissue distribution and probably enters the fluid from surrounding structures. 6. Alpha-fetoprotein in amniotic fluid is of fetal origin as it is present in maternal serum at far lower concentrations. It is found in fetal serum, urine and yolk sac, but it is not clear how it enters the amniotic fluid of normal fetuses. The concentrations of Gc and alpha-fetoprotein have been measured in amniotic fluid and in their sera of origin. The relative concentration of Gc in amniotic fluid was found to be much greater than that of alpha-fetoprotein and the concentration gradients of these marker proteins can be compared with data for other proteins. In this way further evidence has been obtained that the albumin, α1,-antitrypsin and transferrin in amniotic fluid are mainly of maternal origin throughout pregnancy. 7. Immunological studies have shown that at least three proteins of non-serum origin are present in amniotic fluid and they have also been located in the amnion and uterine decidua. 8. The enzymes present in amniotic fluid are summarized. Many lysosomal enzymes are clearly of fetal origin since they show altered specific activities in the appropriate cases where the fetus is affected with an inborn error of metabolism. For other enzymes, analysis of specific activity gradients can help to decide the extent to which an enzyme is of serum origin, although this will not exclude the possibility of a maternal (uterine) contribution. The results of such analyses suggest that, relative to the serum protein in amniotic fluid, the greatest concentrations of the minor non-serum proteins in the fluid occurs between thirteen and eighteen weeks of pregnancy and also towards term. 9. Some inborn errors of metabolism may be diagnosed prenatally by measuring the specific activity of the respective enzyme in amniotic fluid. However, the presence of different enzymes with similar substrate specificities has prevented this in Pompe's disease. 10. In cases where the fetus is affected with anencephaly or spina bifida there is an increase in the concentration of alpha-fetoprotein in the amniotic fluid. This has provided a way of detecting these diseases early enough to allow termination of pregnancy. 11. The discovery of new proteins in fetal serum and in the tissues surrounding the amniotic cavity would seem to provide the best chance of extending the uses of amniotic fluid into the other areas of prenatal medicine.

Optimal design: Some geometrical aspects of D-optimality

Abstract: SUMMARY The duality relationships between D-type optimal designs and problems of covering a subset of Euclidean space by central ellipsoids and ellipsoidal cylinders are described and consequences that aid the solution of either problem are discussed. It is shown that there are also design duals for the problems of finding minimal covering spheres and ellipsoids or cylinders whose centres or axes are chosen optimally.

Assessment of the psychosocial outcome after severe head injury.

Abstract: Rehabilitation services for the severely brain injured are often inadequate and one of the chief factors responsible is undue emphasis on the contribution of physical disability with scant attention to the serious emotional and intellectual handicaps incurred. Weakness, spasticity and dysphasis tend to recover eventually to a variable extent but mental handicap is often the cause of serious and lasting disablement. For a determination of the outcome of severe brain injury in terms of its effect on daily living, the relation between physical disability, mental handicap and social reintegration has been assessed quantitatively. Three assessment scales have been constructed and used in a study of 58 severely brain damaged patients. This revealed that the duration of post-traumatic amnesia correlates highly with the degree of social, mental and physical disability incurred. Daily living was affected primarily by impairment of intellect and personality and, to a lesser extent, by physical incapacity, but only rarely by the developments of symptoms of mental illness. Using the Wechsler Adult Intelligence Scale, the time course of cognitive recovery was also assessed. Recovery curves and the relation of cognitive impairment to social and physical handicap will be demonstrated.

Genetic control of immune responses to parasites: immunity to Trichuris muris in inbred and random-bred strains of mice.

Abstract: A comparison has been made of the responses of random-bred CFLP and inbred NIH mice to infection with Trichuris muris . Random-bred mice showed greater variation in worm burdens and less uniformity in worm expulsion. Irradiation prior to infection reduced variation, but did not increase the mean level of infection above that shown by the most susceptible unirradiated mice. In NIH mice, however, irradiation raised the level of infection in all mice. The factors responsible for variation between CFLP mice and for the level of infection in NIH mice came into play after the fifth day of infection and were inactivated by cortisone acetate. It is suggested that these factors are immunologically mediated and under direct genetic control. Uniformity of infection and expulsion in NIH mice is therefore seen as a consequence of genetic uniformity; variability in CFLP mice as a consequence of genetic variation. The time of worm expulsion was found to differ markedly between inbred strains of mice. Hybrid progeny showed the expulsion time characteristic of the parental strain with the most rapid expulsion; greater resistance was therefore inherited as a dominant characteristic. The genetic control of immunity to T. muris is discussed in the context of the antibody- and cell-mediated components of the expulsion process.

Chemotaxis of lymphoblasts.

Abstract: LYMPHOCYTES are motile cells whose movement in vivo seems to be directed, yet investigators over many years have repeatedly failed to show chemotaxis of lymphocytes in vitro. There have been some recent reports that lymphocytes migrate into micropore filters towards substances placed below the filter1–3, but this migration was not found to be chemotactic3. It seemed to us that our and other people's failure to demonstrate lymphocyte chemotaxis might be because we were using the wrong population of cells. The lymphocytes which can be shown most clearly to migrate into inflammatory lesions in vivo are blast-transformed cells 4–6, and we therefore examined the migration in Boyden chambers of lymphoblasts from two sources; firstly cloned human lymphoblast cell lines maintained in continuous culture7; and secondly blast cells from the lymph nodes of CBA mice, either without deliberate sensitisation with antigen, or following exposure to the contact sensitising agent, oxazolone. Both human and mouse lymphoblasts were shown to migrate into filters towards chemoattractants. The nature of this migration is discussed below.