Immunological Phenomena Associated with Cross-Reactive Antigens of Micro-Organisms and Mammalian Tissues (Part 1 of 2)

Author(s):  
I.M. Lyampert ◽  
T.A. Danilova
1974 ◽  
Vol 137 (2) ◽  
pp. 239-248 ◽  
Author(s):  
Anthony E. Pegg

1. The sites within the tRNA sequence of nucleosides methylated by the action of enzymes from mouse colon, rat kidney and tumours of these tissues acting on tRNAAsp from yeast and on tRNAGlu2, tRNAfMet and tRNAVal1 from Escherichia coli were determined. 2. The same sites in a particular tRNA were methylated by all of these extracts. Thus tRNAGlu2 was methylated at the cytidine residue at position 48 and the adenosine residue at position 58 from the 5′-end of the molecule; tRNAAsp was methylated at the guanosine residue at position 26 from the 5′-end of the molecule; tRNAfMet was methylated at the guanosine residues 9 and 27, the cytidine residue 49 and the adenosine residue 59 from the 5′-end; tRNAVal1 was methylated at the guanosine residue 10, the cytidine residue 48 and the adenosine residue 58 from the 5′-end. 3. All of these sites within the clover leaf structure of the tRNA sequence are occupied by a methylated nucleoside in some tRNA species of known sequence. It is concluded that methylation of tRNA from micro-organisms by enzymes from mammalian tissues in vitro probably does accurately represent the specificity of these enzymes in vivo. However, there was no evidence that the tumour extracts, which had considerably greater tRNA methylase activity than the normal tissues, had methylases with altered specificity capable of methylating sites not methylated in the normal tissues.


Attempts to achieve “internal disinfection,” that is to say, to kill organisms in the body of infected animals by means of drugs, have hitherto afforded little promise of success in the case of the common pathogenic bacteria, the only exception being the action of ethyl-hydrocuprein in pneumococcus infections, discovered by Morgenroth with his co-workers, Levy and others. The reasons for the failure are probably to be attributed mainly to two facts; in the first place, antiseptics in general enter into combination with proteins of the tissues and body fluids, either by a process of physical adsorption or by the formation of chemical compounds. In either case, the usual result is that the bactericidal action of a substance, as determined in a watery medium, is greatly reduced by protein-solutions, e. g. , serum. Secondly, the majority of chemical antiseptics are general protoplasm poisons, and exert on mammalian tissues a degree of toxic action equal to, or greater than, that which they exhibit towards micro-organisms; hence these substances prove lethal for animals in doses which are insufficient to confer bactericidal properties on the body fluids. The classical example of such failures was afforded by mercuric chloride, which Koch employed in the hope of treating effectively anthrax septicæmia in animals. Ehrlich and Bechhold investigated compounds which were more potent antiseptics than any hitherto known, among the most active being tetrabrom- (and chlor-) ortho-biphenol; they found, however, that the bactericidal properties of these substances were also greatly reduced when the organisms were suspended in a serum medium. Thus, tetrachlor-orthobiphenol in a concentration of 1 : 320,000 prevented the growth of diphtheria bacilli in bouillon, whereas in serum growth occurred in the presence of 1 : 10,000 of this reagent. Similarly we have found that the dose of perchloride of mercury which is required to inhibit completely the growth of Staphylococcus aureus or B. coli in serum is 100 times greater than that which produces this effect in watery medium containing a small amount of nutrient peptone (0·7 per cent.).


Development ◽  
1973 ◽  
Vol 29 (2) ◽  
pp. 331-345
Author(s):  
Carol-Ann Manen ◽  
Diane H. Russell

Polyamine synthesis and accumulation was studied in several species of developing sea urchins. Most striking is the presence in the gametes of a large amount of spermine, with low amounts of putrescine and spermidine. This contrasts with the pattern of polyamines present in both micro-organisms and mammals. Micro-organisms contain mainly putrescine and spermidine and adult mammalian tissues usually contain equimolar concentrations of spermidine and spermine. During development (i.e. to gastrulation) there is a large increase in the spermidine concentration with relatively little change in either putrescine or spermine levels. After gastrulation, both spermidine and spermine concentrations are elevated. These new accumulations parallel the new synthesis of rRNA that occurs after gastrulation. Enzyme activity patterns parallel the changes detected in the concentrations of the polyamines with the exception of ornithine decarboxylase activity. This exception may be due to the rapid turnover of putrescine, the precursor for the synthesis of spermidine and spermine.


1947 ◽  
Vol 45 (3) ◽  
pp. 297-306 ◽  
Author(s):  
J. Gordon ◽  
J. W. McLeod ◽  
Anna Mayr-Harting ◽  
J. W. Orr ◽  
K. Zinnemann

There have been groups of observers both in this country and in Germany who have been entirely sceptical about the value of the prophylactic application of antiseptics to wounds and who seem to incline to the opinion that such medication is likely to be more harmful than useful; e.g. Colebrook in a special report to the Medical Research Council (1928) stated that ‘the ordinary “antiseptics” have a higher affinity for the leucocytes than for the microbes, and by combining with the former forfeit their microbicidal potential’. Further, he stated that with the exception of optochin and neosalvarsan, substances which have been tried as antiseptics are so rapidly fixed on serum proteins, blood cells, and the fixed tissues, that they fail to impart bactericidal power to the serum. Fleming (1924, 1931) in a number of ingenious experiments showed that injury to leucocytes is the most likely outcome of antiseptic applications to wounds, and has argued that they are more likely to be harmful than useful for that reaon; later (1938), he pointed out the superiority of the sulphonamides to the older antiseptics as tested by his ‘slide cell’ technique and in penicillin he has discovered an antiseptic which in respect of a high ratio of bactericidal potency to its toxicity to mammalian tissues approaches the ideal. This has given the clinical results which would be expected on theoretical grounds. There are, however, limitations to the use of penicillin as a general prophylactic antiseptic application which depend on (a) its failure to destroy some types of bacteria which cause suppuration, (b) its relative lability, (c) its present cost. There is therefore ground for further careful assessment of the best prophylactic antiseptic. Fleming (1940) has in fact admitted that there may be a place for proflavine in the interim dressing of wounds pending surgical treatment. The German opinion on the question of the prophylactic use of antiseptics seems to have been considerably influenced by the observations of Schimmelbusch, who had demonstrated that mice inoculated on a scarified area of the tail with anthrax bacilli could not be saved when the tail was amputated at a point proximal to the site of inoculation even 10 min. after the wound had been infected. It was concluded on this account that the penetration of bacteria from a wound into the deeper tissues was so rapid that local treatment of the wound was obviously futile. Schiemann & Wreschner (1922) and Weise (1922), however, who record these observations of Schimmelbusch, made similar observations with streptococci but showed that with this micro-organism not only tail amputation but also local application of antiseptics was often successful in saving mice so infected. They did not dispute the rapid penetration of the bacteria but concluded that in the case of the streptococcus the body could deal with limited numbers of these micro-organisms, if the local lesions from which they were reaching the general circulation were eliminated. Further, Browning (1943) in a discussion of the antiseptic action of the amino acridine compounds made an extensive survey of the literature on the influence of these substances on leucocytes and concluded that in view of the wide variations in results the particular technique adopted must be an important factor. Hence he suggests there is need for much caution in accepting such results as an indication of what will actually happen in the animal body.


2010 ◽  
Vol 38 (5) ◽  
pp. 1294-1301 ◽  
Author(s):  
Barbara M. Bakker ◽  
Karen van Eunen ◽  
Jeroen A.L. Jeneson ◽  
Natal A.W. van Riel ◽  
Frank J. Bruggeman ◽  
...  

Human metabolic diseases are typically network diseases. This holds not only for multifactorial diseases, such as metabolic syndrome or Type 2 diabetes, but even when a single gene defect is the primary cause, where the adaptive response of the entire network determines the severity of disease. The latter may differ between individuals carrying the same mutation. Understanding the adaptive responses of human metabolism naturally requires a systems biology approach. Modelling of metabolic pathways in micro-organisms and some mammalian tissues has yielded many insights, qualitative as well as quantitative, into their control and regulation. Yet, even for a well-known pathway such as glycolysis, precise predictions of metabolite dynamics from experimentally determined enzyme kinetics have been only moderately successful. In the present review, we compare kinetic models of glycolysis in three cell types (African trypanosomes, yeast and skeletal muscle), evaluate their predictive power and identify limitations in our understanding. Although each of these models has its own merits and shortcomings, they also share common features. For example, in each case independently measured enzyme kinetic parameters were used as input. Based on these ‘lessons from glycolysis’, we will discuss how to make best use of kinetic computer models to advance our understanding of human metabolic diseases.


Author(s):  
L. Reimer

Most information about a specimen is obtained by elastic scattering of electrons, but one cannot avoid inelastic scattering and therefore radiation damage by ionisation as a primary process of damage. This damage is a dose effect, being proportional to the product of lectron current density j and the irradiation time t in Coul.cm−2 as long as there is a negligible heating of the specimen.Therefore one has to determine the dose needed to produce secondary damage processes, which can be measured quantitatively by a chemical or physical effect in the thin specimen. The survival of micro-organisms or the decrease of photoconductivity and cathodoluminescence are such effects needing very small doses (see table).


Author(s):  
W. E. Rigsby ◽  
D. M. Hinton ◽  
V. J. Hurst ◽  
P. C. McCaskey

Crystalline intracellular inclusions are rarely seen in mammalian tissues and are often difficult to positively identify. Lymph node and liver tissue samples were obtained from two cows which had been rejected at the slaughter house due to the abnormal appearance of these organs in the animals. The samples were fixed in formaldehyde and some of the fixed material was embedded in paraffin. Examination of the paraffin sections with polarized light microscopy revealed the presence of numerous crystals in both hepatic and lymph tissue sections. Tissue sections were then deparaffinized in xylene, mounted, carbon coated, and examined in a Phillips 505T SEM equipped with a Tracor Northern X-ray Energy Dispersive Spectroscopy (EDS) system. Crystals were obscured by cellular components and membranes so that EDS spectra were only obtainable from whole cells. Tissue samples which had been fixed but not paraffin-embedded were dehydrated, embedded in Spurrs plastic, and sectioned.


Author(s):  
Chi-Ming Wei ◽  
Margarita Bracamonte ◽  
Shi-Wen Jiang ◽  
Richard C. Daly ◽  
Christopher G.A. McGregor ◽  
...  

Nitric oxide (NO) is a potent endothelium-derived relaxing factor which also may modulate cardiomyocyte inotropism and growth via increasing cGMP. While endothelial nitric oxide synthase (eNOS) isoforms have been detected in non-human mammalian tissues, expression and localization of eNOS in the normal and failing human myocardium are poorly defined. Therefore, the present study was designed to investigate eNOS in human cardiac tissues in the presence and absence of congestive heart failure (CHF).Normal and failing atrial tissue were obtained from six cardiac donors and six end-stage heart failure patients undergoing primary cardiac transplantation. ENOS protein expression and localization was investigated utilizing Western blot analysis and immunohistochemical staining with the polyclonal rabbit antibody to eNOS (Transduction Laboratories, Lexington, Kentucky).


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