摘要:

SUMMARYA number of types of organisms has been dried on cellulose fibres and recoveries have been measured after periods of 3–6 years of storage at room temperature and at 37°C. Mixtures of peptone and glucose and peptone and sorbitol have proved effective preserving agents for desiccates stored at room temperature but ineffective for storage at 37°C. Peptone alone was much more satisfactory than the mixtures at the higher temperature.A method for routine preservation of bacteria is described.

ISSN:0004-945X    

DOI:10.1038/icb.1962.1

出版商:Nature Publishing Group    

年代:1962

数据来源: WILEY

摘要:

SUMMARYA maturation process in the mast cells of the rat has been described. It involves an increase in cell size and granule content, accompanied by a progressive sulphation of the granules.A specific stain previously described was found to stain only mature mast cell granules, i.e., those containing the more highly sulphated forms of heparin. The immature mast cell granules, i.e. those containing heparin monosulphate, were not stained by the specific stain but were stained by aqueous methylene blue.

ISSN:0004-945X    

DOI:10.1038/icb.1962.2

出版商:Nature Publishing Group    

年代:1962

数据来源: WILEY

摘要:

SUMMARYExperiments have been performed with rats to investigate the effectiveness of the “mucosal block” theory in preventing absorption of excessive amounts of iron. Animals were given an iron solution in lieu of drinking water for four days and tracer doses of Fe59were administered at various intervals after cessation of iron feeding. Absorption of Fe59was measured by radioassay of the blood and organs of the animals. A comparison of the assays on iron‐fed and control animals shows that there was some reduction of iron absorption in the iron‐fed animals, especially during the first 24 hours, but that the preliminary iron feeding did not effectively prevent absorption at any time. The iron content of the mucosal cell does not appear to be the major factor determining the amount of iron in the rat.In further experiments rats were injected with phenylhydrazine and Fe59was administered while the haemoglobin value was normal but the rate of erythropoiesis raised (shown by an increase in reticulocytes). Under these conditions absorption of iron was considerably higher than in the untreated control animals. These results suggest that the rate of erythropoiesis may be an important factor in the regulation of iron absorption.

ISSN:0004-945X    

DOI:10.1038/icb.1962.3

出版商:Nature Publishing Group    

年代:1962

数据来源: WILEY

摘要:

SUMMARYGroups of rats were injected with “Imferon” and with red cells to increase the storage iron. After seven weeks a tracer dose of iron‐59 was given to each animal and three weeks later the percentage of the dose in the blood, liver and spleen was determined by radioassay. Compared with control animals, decreased absorption of iron‐59 was found in the rats loaded with “Imferon” and with red cells. This suggests that the size of the iron stores is an important factor regulating iron absorption. Some of the unrecovered red cell iron was in tissues other than those assayed, but a large amount was probably lost from the body during the experimental period. These considerations also applied to the “Imferon” injected animals, but in addition some of the “Imferon” was still present in the mesenteric lymph tissues.

ISSN:0004-945X    

DOI:10.1038/icb.1962.4

出版商:Nature Publishing Group    

年代:1962

数据来源: WILEY

摘要:

SUMMARYThe mean haemoglobin value of a group of rats was increased by transfusions of concentrated red cells. Absorption from a test dose of iron‐59 was significantly less than the amount absorbed by untreated control animals. The reduced absorption may be a direct result of the polycythaemia or the result of the depressed erythropoietic activity following the transfusion.Rats exposed to an atmosphere with a reduced oxygen content absorbed more iron than did rats breathing air or air with 5 p.c. CO2. Hypoxia may act directly on the intestinal mucosal cell or through an intermediary compound.

ISSN:0004-945X    

DOI:10.1038/icb.1962.5

出版商:Nature Publishing Group    

年代:1962

数据来源: WILEY

摘要:

SUMMARYChanges in lung weights, histology and bronchographic appearances are recorded in rats subjected to oxygen at 60 p.s.i. (gauge) pressure (OHP). Capillary congestion, progressing to alveolar exudation and haemorrhage, was the earliest observable change. The results failed to support a postulate that lung damage due to oxygen poisoning is primarily an atelectasis due to bronchial obstruction. Positive pressure inflation of lungs immediatelypost mortem, did not reverse oxygen damage. Heparinisation of rats was also without effect on such damage. Exposure of lung tissuein vitroto 100 p.s.i. (gauge) pressure of oxygen for five hours failed to cause changes similar to those observed for OHP lungs exposedin vivo.

ISSN:0004-945X    

DOI:10.1038/icb.1962.6

出版商:Nature Publishing Group    

年代:1962

数据来源: WILEY

摘要:

SUMMARYThe dehydrogenase activities of rat lung, brain and liver were measured before and after exposure of rats to oxygen at 60 p.s.i. gauge pressure (OHP). The rate of methylene blue coupled oxidation of lung tissue was progressively decreased by OHP with an approximately 50 p.c. decline in activity following one hour exposure of animals to OHP. Pentobarbital sodium or cysteamine, administered prior to exposure to OHP, prevented the inhibition of enzyme activity. Death by anoxia had no effect on the dehydrogenase activity of lung tissue.No decrease in the rate of methylene blue coupled oxidation occurred in brain or liver tissue of rats exposed to OHP.

ISSN:0004-945X    

DOI:10.1038/icb.1962.7

出版商:Nature Publishing Group    

年代:1962

数据来源: WILEY

摘要:

SUMMARYA study has been made of the size, frequency and histochemical reactions of PAS‐positive reticulum cells in the thymus cortex of high‐ and low‐leukaemia strain mice.In high‐leukaemia strain thymus glands there were three times as many mitoses in lymphocytes surrounding these cells as in lymphocytes elsewhere in the thymus. The incidence of early stages of mitosis was also higher in PAS cell‐associated mitoses than in mitoses elsewhere in the thymus. In low‐leukaemia strain thymus glands the association of PAS cell and lymphocyte mitoses was less evident.The development of PAS cells in thymus grafts was related to the age of the thymus graft and not affected by circulating factors in the host animal.

ISSN:0004-945X    

DOI:10.1038/icb.1962.8

出版商:Nature Publishing Group    

年代:1962

数据来源: WILEY

摘要:

SUMMARYA survey of serum vitamin B12concentrations has been performed on aborigines living in the following four areas of Western Australia: Warburton Range, Derby, Halls Creek and North Kimberley. In each area, serum B12concentrations showed a range and mean greater than that of a white control population. In each area, values approximated to a normal logarithmic distribution. There was no correlation between serum B12concentration and age, sex, lactation, yaws infection, the concentration of serum protein fractions and irondeficiency anaemia. It is considered probable that the high serum B12levels are due to an increased amount of B12binding protein in the plasma and related in some way to the altered plasma protein synthesis in the aborigine.

ISSN:0004-945X    

DOI:10.1038/icb.1962.9

出版商:Nature Publishing Group    

年代:1962

数据来源: WILEY

摘要:

SUMMARYCross‐agglutination and agglutination‐adsorption studies were conducted on a leptospiral strain isolated from a human being in North Queensland. These studies, conducted in two different laboratories, disclosed the presence of a new serotype member of thepyrogenesserogroup designatedLeptospira robinsoni.

ISSN:0004-945X    

DOI:10.1038/icb.1962.10

出版商:Nature Publishing Group    

年代:1962

数据来源: WILEY