摘要:

SUMMARYDirect catabolism of glucose administered to a fasting human, or its conversion to fat, does not occur to any large extent within three hours; during this period the body continues to catabolise fat and protein reserves at approximately the same rate as in the fasting state.The results suggest that in the fasting state there is a depletion of carbohydrate in some part of the body, and that it is this “glucose debt” which is first repaid when glucose is fed.There seems to be a delay of about 40–60 minutes before equilibrium is reached between glucose supply and glucose disposal by the body.The rise in metabolic rate observed when glucose is supplied at the rate described is explained as being produced by the heat losses involved in its storage rather than in its catabolism to provide energy directly.

ISSN:0004-945X    

DOI:10.1038/icb.1960.10

出版商:Nature Publishing Group    

年代:1960

数据来源: WILEY

摘要:

SUMMARYA method for perfusing the isolated liver of the rat in a gas‐tight system is described. Under the conditions of the experiments, the livers produced bile and metabolized fat for several hours.Some observations on the effect of temperature, perfusion pressure and the concentration of fat in the perfusate on the production of bile are reported. It was found that the production of bile was maximal at 38°C. At temperatures of 32 and 42°C., bile flow was significantly reduced. The volume of bile produced was related to the perfusion pressure and increased as the pressure was raised from 5 to 25 cm. of blood. The concentration of fat in the perfusate had no effect on bile production.There was a significant interaction effect between temperature and perfusion pressure which was thought to be explained by the oxygen requirements of the liver cells in relation to blood flow and bile secretion. The results suggested that bile secretion reached a maximum when all the hepatic sinuses were perfused, provided the oxygen supply to the liver cells was adequate.

ISSN:0004-945X    

DOI:10.1038/icb.1960.11

出版商:Nature Publishing Group    

年代:1960

数据来源: WILEY

摘要:

SUMMARYVetafil, braided polyester yarn, braided silk, monofilament nylon and plain catgut were used to suture wounds in the skin of sheep. The apposition of the edges of the wound, the gauge of the suture material, the tension of the sutures and the dressing were varied. The strength of the wound was used to assess the effect of these various factors. No significant differences were found with the exception that very closely spaced sutures caused a significant decrease in the strength of the wounds. The inflammatory response in the skin caused by the various suture materials was examined histologically. The response varied considerably, but no difference between the various suture materials could be seen.

ISSN:0004-945X    

DOI:10.1038/icb.1960.12

出版商:Nature Publishing Group    

年代:1960

数据来源: WILEY

摘要:

SUMMARYSubstitution of chloride by bromide, nitrate and iodide lessened the force of isotonic contraction in cardiac muscle.Toxic effects found during iodide perfusion were reversed by strophanthin‐G, CaCl2, plasma and fresh Ringer solution. Low CaCl2and high KCl precipitated toxicity.Bromide, nitrate and iodide failed to affect contracture.The contrast between these results and those reported for skeletal muscle is discussed.

ISSN:0004-945X    

DOI:10.1038/icb.1960.13

出版商:Nature Publishing Group    

年代:1960

数据来源: WILEY

摘要:

SUMMARYPlasma exerts a positive inotropic action on the isolated heart. The inotropic response is similar to that induced by the glycosides.DNP and quinidine sulphate both fail to depress the activity of plasma but abolish that of the glycosides.Plasma activity is increased when hearts are perfused in low calcium Ringer solution.Anterior pituitary extract restored the response of the winter heart to plasma.The possibility that plasma normally contains a substance which regulates myocardial contractility is discussed.

ISSN:0004-945X    

DOI:10.1038/icb.1960.14

出版商:Nature Publishing Group    

年代:1960

数据来源: WILEY

摘要:

SUMMARYThe uptake of radioiron by mammalian reticulocytes is a rapid process and haem is synthesised from the iron almost immediately. The process is slower with avian erythrocytes and this is possibly related to a slower but more prolonged synthesis of protoporphyrin by the nucleated cells. This synthesis must account for all the Fe59haemoglobin formedin vitrounder the experimental conditions. Incubation of both reticulocytes and nucleated cells, before addition of iron, reduces both uptake of iron and synthesis of haem. It is postulated that there are two stages in the process of intracellular haem synthesis. The first is the entry of iron into the cell and this is inhibited by mercuric chloride but not by other enzyme inhibitors. The second phase, haem synthesis, is inhibited by potassium cyanide, and is therefore apparently dependent on oxidative respiration.

ISSN:0004-945X    

DOI:10.1038/icb.1960.15

出版商:Nature Publishing Group    

年代:1960

数据来源: WILEY

摘要:

SUMMARYThe mechanism of mast cell disruption and release of histamine following antigen‐antibody reactions was investigated by means of anin vitrosystem using mast cells isolated from the rat. Following the reaction between antigen and freshimmune rat serum, a substance was produced which caused the disruption of added mast cells with the release of histamine. This substance was labile at 37° C., becoming inactive within 10 minutes. Its formation depended on the presence of complement as well as antigen and antibody.

ISSN:0004-945X    

DOI:10.1038/icb.1960.16

出版商:Nature Publishing Group    

年代:1960

数据来源: WILEY

摘要:

SUMMARYThe growth in tissue culture of a virulent epidemic type of I.L.T. virus, fully adapted to tissue culture is described. It has not been possible to demonstrate a one‐step type of growth, but it is apparent that the eclipse phase of this virus is relatively long, of the order of 18 hours, and is followed by rapid production and release of virus.A prolonged lag phase is noted in the one strain of low virulence examined. This is in keeping with the growth of such strains, as described by other workers.

ISSN:0004-945X    

DOI:10.1038/icb.1960.17

出版商:Nature Publishing Group    

年代:1960

数据来源: WILEY

摘要:

SUMMARYPs. aeruginosawas grown under anaerobic conditions in a synthetic glucose nitrate medium. In the presence of nitrate, carbon dioxide and cellular carbon were the end products of glucose metabolism. The nitrate was reduced almost entirely to gaseous nitrogen or nitrous oxide (18 p.c. of utilised NO3‐N). Continued incubation of anaerobic cultures after the exhaustion of the nitrate did very little to alter the end products of nitrate utilisation, but striking variations were recorded for the glucose utilisation. Up to 11 p.c. of the utilised glucose carbon was recovered as volatile and non‐volatile organic acids. The non‐volatile acids included extensive amounts of lactic and glycollic acids together with smaller quantities of succinic, malic, fumaric, citric, α keto glutaric and oxalacetic acids. The volatile acid was produced in approximately the same quantity in both aerated and anaerobic cultures whether nitrate was present or not. Carbon balances of 100 p.c. were obtained for the anaerobic cultures, but extensive discrepancies in the aerated culture indicated the formation of other undetected end products of glucose metabolism.

ISSN:0004-945X    

DOI:10.1038/icb.1960.18

出版商:Nature Publishing Group    

年代:1960

数据来源: WILEY

摘要:

SUMMARYA marked species difference in the capacity of plasma protein fractions to combine with corticosteroids has been demonstrated by the use of C14‐labelled cortisol and corticosterone, and paper electrophoresis methods. Of the five species studied, human serum had the highest and sheep serum the lowest capacity for corticosteroid binding.Studies made on the properties of corticosteroid protein complexes showed that the eluted corticosteroids were unaltered physically; there was an interchange between the bound and added corticosteroid; there was no competition for sites between the individual corticosteroids. It was shown in human sera that, at maximum binding between corticosterone‐4‐C14and albumin, approximately 5 albumin molecules per 1 corticosterone molecule were involved.The findings indicate the complexity of the characteristics of the protein carrier mechanism for steroid hormones in diverse animal species.

ISSN:0004-945X    

DOI:10.1038/icb.1960.19

出版商:Nature Publishing Group    

年代:1960

数据来源: WILEY