摘要:

SummaryPathological changes in the sheep following ligation of the hepatic bile duct, combined ligation of both the hepatic bile duct and the branch of the hepatic artery to the ventral lobe, ligation of the common bile duct and ligation of the hepatic artery to the ventral lobe, are described and discussed. It was demonstrated that a combination of obstruction of the biliary drainage and a considerable decrease of the blood How was required to produce the maximum degree of bile ductule proliferation and parenchymal atrophy seen in the chronic stage of facial eczema in the sheep. Obstruction of the common bile duct did not reproduce the liver changes of facial eczema. Although evidence is cited in the sheep, which suggests that some degree of interference with blood supply followed ligalion of the hepatic duct only, the lesion produced was not comparable in degree to that of facial eczema.

ISSN:0004-945X    

DOI:10.1038/icb.1965.1

出版商:Nature Publishing Group    

年代:1965

数据来源: WILEY

摘要:

SummaryA comparative study has been made of the growth and repopulation of thymus grafts in the subcapsular space of the kidney and in the subcutaneous tissues of mice. In both sites thymus grafts underwent initial necrosis followed by regeneration, and in both sites the lymphoid population was replaced by host cells. In the kidney capsule site, thymus graft growth was six times more rapid and lymphoid differentiation and proliferation occurred earlier than in the subcutaneous sites. Kidney tissue did not potentiate the growth of thymus tissue in mixed grafts of thymus and kidney tissue. The initial delay in lymphoid differentiation of subcutaneous thymus grafts may be significant in determining the susceptibility to neoplastic change in these thymus grafts.

ISSN:0004-945X    

DOI:10.1038/icb.1965.2

出版商:Nature Publishing Group    

年代:1965

数据来源: WILEY

摘要:

SummaryRabbitpox virus (RPu+), 18 white pock (u) mutants derived from it and several strains of vaccinia virus were examined in respect to their cytopathology in chick embryo fibroblast cultures, and several continuous lines of mammalian cells; PK‐2a (pig kidney), L929 (mouse fibroblast), FAF (Chinese hamster fibroblast), AT (Chinese hamster, epithelial), KB (human epithelial), FL (human amnion) and Chang liver (human epithelial). The plaquing characteristics of the viruses, and the capacity to multiply exhibited by those which did not produce plaques, were investigated in chick fibroblast, PK‐2a, and L929 cells.Cytopathic changes were characterized by early toxic effects, cellular fusion, and progressive destruction of monolayers, the pattern of changes being a function of specific virus‐cell combinations. With input inocula of 1‐5 PFU per cell, most of the virus strains and mutants produced toxic changes in most of the epithelial type cells (PK‐2a, FL, Chang liver) but not in the fibroblastic cells, and to a very slight degree in KB cells. Three mutants which failed to multiply in PK‐2a cells nevertheless produced moderate toxic changes in them.Pronounced fusion of cells was produced in the epithelial type cells, but not in fibroblastic cells, by most of the viruses which multiplied in them, but not by mutants which failed to multiply.All the mutants produced plaques on chick embryo fibroblasts, and these could be distinguished as turbid or clear, and differed in size and in cultural requirements for maximal plating efficiency. A standard plaque assay method is described which gives good plaques with the majority of mutants.Conditions for optimal plaque assays on PK‐2a and L929 cells are also described, and several distinctive plaque types were recognized. Some mutants failed to produce plaques on PK‐2a or L929 cells, and in all cases except one this was shown to be due to their failure to multiply in the cells concerned.

ISSN:0004-945X    

DOI:10.1038/icb.1965.3

出版商:Nature Publishing Group    

年代:1965

数据来源: WILEY

摘要:

SummaryOne volume of plasma with 6–8 units heparin per ml. incubated with two volumes of 0·3M d‐glucose formed clots after 30 to 100 minutes at 37°. Incubation with thiourea or sodium chloride produced smaller quantities of plasma clots. Heparinised plasma from a haemophilia A patient (factor VIII deficiency) and plasma from patients, under treatment with oral anticoagulants, deficient in factor II (prothrombin), factor VII (proconvertin), and factor X (Prower‐Stuart factor) did not clot after incubation with d‐glucose. Platelets are essential in this process but can be replaced by erythrocyte ghosts or by brain phospholipids but lecithins are inactive. Calcium ions must also be present. No appreciable loss of heparin occurred, but clotting was associated with reduction of heparin co‐factor (antithrombin II). The thrombin clotting time of heparinised plasma which contained d‐glucosc, mannitol, saccharose, glycine and also thiourea was shorter than that in the presence of sodium chloride. In contrast, thrombin clotting time of citrated plasma is not shortened by any of the above compounds except glycine. Incubation of plasma containing between 1 and 1·6 heparin units/ml. without further additions produced high yield of plasma clots. The addition of thromhin to heparinised plasma gave shorter clotting times in platelet‐containing plasma than in platelet poor plasma. The yield of plasma clot was dependent upon the thrombin concentration, but a low concentration of thrombin added to heparinised platelet‐containing plasma caused more fibrin formation than in platelet‐poor plasma. A low concentration of thrombin added to platelet‐containing plasma deficient in factor II (prothrombin), factor VII (proconvertin), factor X (Prower‐Stuart factor) gave a low yield of fibrin. The difference of fibrin yield between platelet‐containing and platelet‐poor plasma was seen with both commercial and purified bovine thrombin preparations. Very dilute human brain extracts added to heparinised platelet‐poor plasma gave, despite a very long clotting time, high yields of fibrin. Heparin co‐factor activity (antithrombin II) is greater in plasma than in serum.

ISSN:0004-945X    

DOI:10.1038/icb.1965.4

出版商:Nature Publishing Group    

年代:1965

数据来源: WILEY

摘要:

SummaryA study has been made of the distribution of the heat labile protective antigen ofSalmonella typhinuriumamongst other strains of apparently unrelated gram‐negative bacteria. Evidence is presented to show that this antigen is possessed by a number of different species of bacteria. Results obtained on the protective effect of various antigens fromSalmonella typhimurumsuggest that only certain antibodies are effective in promoting killing by phagocytic cells, though all may’ enhance phagocytosis.

ISSN:0004-945X    

DOI:10.1038/icb.1965.5

出版商:Nature Publishing Group    

年代:1965

数据来源: WILEY

摘要:

SummaryStonefish venom has been fractionated on carboxymethyl cellulose and Sephadex columns; of the fractions obtained only one was toxic to rats. The active fraction contained a relatively high proportion of aromatic amino acids. Whole venom was examined for enzyme activity and enzyme inhibition; the only significant activity found was that of hyaluronidase. The venom also caused a marked increase in capillary permeability. Ultracentrifuge measurements suggest that the toxic material has a molecular weight of the order of 150,000.

ISSN:0004-945X    

DOI:10.1038/icb.1965.6

出版商:Nature Publishing Group    

年代:1965

数据来源: WILEY

摘要:

SummaryNormal rabbit inferior vena cava has been examined with the electron microscope. Endothelium forms a continuous coating without pores or basement membrane. Occasional small vessels are present in the intima. Beneath the endothelium is a connective tissue space containing fibrils and amorphous ground substance. There is an internal elastic layer which is fenestrated and branching and rough on both endothelial and medial surfaces. With specific staining the vesicular structure of elastin is seen. The smooth muscle cells of the media are distinct entities; there is no conclusive evidence of their regular attachment either to the elastic lamina or to each other. The smooth muscle cells do not have a prominent basement membrane and are surrounded by an intercellular connective tissue space containing collagen fibrils and occasional small patches of elastin. The adventitia contains collagen fibres, blood vessels and nerve fibres.

ISSN:0004-945X    

DOI:10.1038/icb.1965.7

出版商:Nature Publishing Group    

年代:1965

数据来源: WILEY

摘要:

SummaryThe electron microscopic changes in rabbit inferior vena cava in partial obstruction resemble the ultra‐structural vascular response to other types of alteration in cellular environment. First there is an appearance of hyperactivity and metabolic stimulation with deposition of elastin and collagen fibres and reversion of cells of intima and media to a more primitive type. Later, following subsidence of activity, there is apparent cellular degeneration and tissue simplification.

ISSN:0004-945X    

DOI:10.1038/icb.1965.8

出版商:Nature Publishing Group    

年代:1965

数据来源: WILEY

ISSN:0004-945X    

DOI:10.1038/icb.1965.65

出版商:Nature Publishing Group    

年代:1965

数据来源: WILEY

摘要:

SummaryRats were rendered tolerant to the bacterial antigenSalmonella adelaideflagellin by intraperitoneal antigen injections in the newborn period. Some rats received a single injection of 100 μg. of flagellin on the day of birth; others a course of twice‐weekly injections for the first 12‐16 weeks of life, the dose per injection usually being 10 μg. At 12 weeks of age, challenge injections of125I‐labelled flagellin or flagella were given, the purpose being to compare the pattern of antigen localization in lymph nodes or spleen with that observed in non‐tolerant control animals.The results showed that most tolerant animals handled the labelled antigen no differently from the controls. Some animals given the twice‐weekly injection course showed enhanced follicutar localization of the antigen. As prior active or passive immunization also causes enhanced follicular localization of antigens, this suggested that in these animals the tolerant state had not been complete, and that traces of antibody directed to minor antigenic components might have exerted an opsonic effect.The theoretical significance of the essentially normal “recognition of foreignness” exhibited by most tolerant animals is discussed.

ISSN:0004-945X    

DOI:10.1038/icb.1965.66

出版商:Nature Publishing Group    

年代:1965

数据来源: WILEY