bluuebunny/crossref_metadata_2025_split huggingface dataset:
DENSITY SEPARATION AND CHARACTERISATION OF HUMAN BLOOD LEUCOCYTES, INCLUDING T AND B LYMPHOCYTES
Authors: Williams N , Moore MAS , Shortman K , Condon Linda , Pike Beverley , Nossal GJV 
Published: November 2007

SummaryHuman blood leucocytes were separated on the basis of buoyant density on high resolution, continuous albumin gradients. Polymorphonuclear leucocytes were dense, while mononuclear cells were light. There was substantial overlap between monocytes and lymphocytes. Both populations were heterogeneous within a restricted density range, and both were variable from one individual to another. This heterogeneity and variability of mononuclear elements contrasted with other human blood cells, such as erythrocytes and the progenitors of monocytes and granulocytes. The possible basis for variability is discussed.There was some separation between T and B lymphocytes, with the B cells (cells with a high surface density of immunoglobulin) enriched in the lighter density fractions. However, the overlap between T and B cells was too extensive for use as a general separation procedure. The response to phytohaemagglutinin mitogen (PHA) appeared to follow the overall T cell (immunoglobulin‐negative) distribution, with no marked separation of PHA responsive from PHA non‐responsive lymphocytes.
STUDIES OF PLASMA BRADYKININASES USING RADIOLABELED SUBSTRATES
Authors: Zacest R , Oparil Suzanne , Talamo RC 
Published: November 2007

SummaryThe activities of human plasma bradykininases (kininase I and II) have been investigated because of their importance as reactants in the kallikrein‐kinin system. The use of [14C] bradykinin as substrate allows radiometric analysis of the enzyme‐substrate reaction mixture. This is possible because separation of bradykinin from its hydrolysis products is achieved by chromatography over CM Sephadex C‐25. Use of this technique has allowed localization of bradykininase activities in plasma protein chromatograms and the separation and partial purification of kininase I and kininase II. Kininase I can be identified because it hydrofyses hippuryl‐L‐lysine, whereas kininase II converts angiotensin I to angiotensin II. The measurement of hydrolysis is simple and quantitative and has been used to demonstrate normal Michaelis‐Menten kinetics for both enzymes. The Michaelis‐Menten constants for the enzymes have been found to be 4·1 × 10‐7 M (kininase I) and 0·94 × 10‐7 M (kininase II).
“SPONTANEOUS” CYTOLYSIS BY NORMAL HUMAN LYMPHOCYTES OF BURKITT'S LYMPHOMA CELLS OF THE EB2 CELL LINE
Authors: Matthews N , Maclaurin BP 
Published: November 2007

SummaryPrevious studies have shown that non‐sensitised lymphocyte preparations can kill antibody‐coated allogeneic lymphoma cells. During these studies on antibody‐induced lymphocyte‐mediated cytotoxicity it was observed that lymphocyte preparations from most normal humans tested were highly cytotoxic even to non‐antibody‐coated lymphoma cells of a particular cell line (EB2) but not to a second lymphoma cell line (CLA4), or to allogeneic normal lymphocytes. In contrast, if the target cells were coated with antibody, normal lymphocyte preparations killed EB2 cells, CLA4 cells and allogeneic lymphocytes, with equal facility.This non‐antibody‐dependent “spontaneous” cytotoxicity towards EB2 cells occurred even at low lymphocyte:EB2 ratios (< 10:1) and was not mediated by lymphotoxin. “Spontaneous” anti‐EB2 lymphocytotoxicity was increased rather than blocked in the presence of specific anti‐EB2 serum.The possible relationship between “spontaneous” cytolysis of EB2 cells and sensitization to EB virus is discussed.
THE ULTRASTRUCTURE OF LIPID PARTICLES IN EMULSIONS PREPARED WITH VARIOUS EMULSIFIERS
Authors: Jeppsson Roland , Schoefl Gutta I 
Published: November 2007

SummaryLipid particles of soya bean oil emulsions prepared with various emulsifying agents (egg yolk phosphatides, acetylated monoglycerides and poly‐oxypropylene‐polyoxyethylene polymers) were examined in sections of osmium‐fixed pellets. The mean particle size fell within the range of 0·3 to 0·8 μm for all but one emulsion and did not appear to be related to the emulsifying system used.Morphologically, particles of emulsions containing phosphatides were coated by an electron dense granular surface layer which was absent with the other emulsifiers. The presence of drugs in the oil phase did not alter the appearance of the lipid particles.
FRACTIONATION OF NORMAL HUMAN BONE MARROW ON ALBUMIN GRADIENTS
Authors: Rickard KA , Dunleavy L , Brown R , Kronenberg H 
Published: November 2007

SummaryMultiple samples of normal human bone marrow from different donors have been fractionated on discontinuous albumin gradients and the nutrient agar system utilised as an assay procedure for the detection of colony‐forming cells in the resulting fractions. The colony‐forming cell, an early granulocytic progenitor, is consistently present in the lighter density fractions. There appeared to be no clear separation of this cell from the T lymphocyte population. The colony‐forming cell whose proliferative status was unaltered during the fractionation process could be clearly separated from the differentiated granulocytes on these gradients. In a potential marrow transplant situation it appears that greater resolution will be necessary than is afforded by albumin gradients for the separation of haemopoietic stem cells from cells responsible for graft versus host disease.
INHIBITION OF GROWTH OF MARROW CELLS BY CHLORAMPHENICOL
Authors: Morley Alec , Furness Margaret , Higgs David 
Published: November 2007

SummaryAddition of chloramphenicol inhibited the growth of human and murine marrow cells in tissue culture in soft agar. Human cells were less sensitive than murine cells. The degree of inhibition was dependent on concentration of chloramphenicol and varied between individuals. The logarithmic mean of the concentration causing 50% inhibition of growth was 14·3 μg/ml and the range of 2 S.D. on either side of the mean was 3 to 75 μg/ml. Addition of phenylalanine did not reverse the effect. The soft agar culture system may be a suitable model for studying acute suppression of haemopoiesis produced by chloramphenicol.
THE CYTOTOXIC EFFECT OF HAEMOCYTES FROM THE CRAYFISH (PARACHAERAPS BICARINATUS) ON TUMOUR CELLS OF VERTEBRATES
Authors: Tyson CJ , Jenkin CR 
Published: November 2007

SummaryHaemocytes from the crayfish (Parachaeraps bicarinatus) have been found to be cytotoxic for various tumour cell lines. Recognition of the tumour cell appears to be mediated via trypsin labile receptors on the membrane of the haemocyte. From studies using different ratios of target cells to haemocytes, it would appear that the majority of haemocytes possess these cytotoxic properties.
RADIOSENSITIVITY OF SUPPRESSOR CELLS IN NEWBORN RATS
Authors: McCullagh Peter 
Published: November 2007

SummaryThe resistance of neonatal rats to sustaining adoptive immune responses against heterologous erythrocytes following the transfer of normal thoracic duct lymphocytes was examined. Irradiation of the neonatal rat at levels as low as 350 rad was found to be effective in overcoming this resistance, although preliminary exposure to antigen could interfere with facilitation of adoptive responses by irradiation. It is suggested that the failure of the neonate to sustain adoptive immune responses is explicable on the basis of an active suppression and, as a corollary, unresponsiveness resulting either from macrophage immaturity or the transfer of maternal antibody is discounted as a likely explanation for the immunological behaviour of the newborn rat towards the antigens examined.
ROLE OF THE THYMUS IN SUPPRESSION OF IMMUNE RESPONSES IN NEWBORN RATS
Authors: McCullagh Peter 
Published: November 2007

SummaryThe role of thymus‐derived cells in controlling the process of immunological maturation in the neonatal rat has been examined. Thymectomy performed on the day of birth resembled irradiation given at this time in that it permitted adoptive immune responses to sheep erythrocytes to be initiated in the neonatal host. Whereas the consequences of irradiation could be demonstrated if antigenic challenge was given on the following day, adoptive responses were not sustained unless an interval in excess of 24 h had elapsed after thymectomy, suggesting that extra‐thymic suppressor cells persist for at least this period. Suppression of adoptive responses was achieved in irradiated hosts with thymus cells obtained from rats on their day of birth but not with cells from older donors. Using the transfer of allogeneic lymphocytes as a stimulus, antibody‐forming cell precursors were shown to be plentiful in the newborn rat and it was accordingly suggested that thymic suppressor cells are responsible for the poor responsiveness of newborn rats to antigenic challenge.
FACILITATION OF THE GROWTH OF AN ALLOGENEIC TUMOUR BY SUPPRESSOR CELLS IN NEWBORN RATS
Authors: Van Der Gaag Ruth , McCullagh Peter 
Published: November 2007

SummaryThe intravenous injection of as few as 15 Walker tumour cells into newborn rats consistently resulted in the development of pulmonary metastases and the death of the recipient within 2 weeks. Neither the outcome of tumour cell injection nor the interval until death could be modified by transferring 2 × 107 lymphocytes from tumour‐immune adult rats to the neonatal hosts. In contrast with this failure to transfer adoptive anti‐tumour immune responses to intact recipients, the administration of 350 rad irradiation before transfer of 10° immune lymphocytes constantly afforded protection against inoculated tumour cells. The simultaneous transfer of neonatal thymus cells with immune lymphocytes interfered with the establishment of an adoptive response in the irradiated newborn. Initiation of a graft‐versus‐host response in F1 hybrid neonates by injecting parental strain lymphocytes conferred resistance to tumour growth on the recipient, the magnitude of this effect increasing with the strength of the graft‐versus‐host reaction.
COMPARISON OF COLLAGENASE ACTIVITY IN EOSINOPHIL AND NEUTROPHIL FRACTIONS FROM RAT PERITONEAL EXUDATES
Authors: Bassett EG , Baker JR , Baker PA , Myers DB 
Published: November 2007

SummaryThe collagenase activity has been compared in extracts of eosinophils and of neutrophils from peritoneal exudates in two groups of rats, one of which had been treated to augment the numbers of eosinophils and the other the numbers of neutrophils. The proportion of granulocytes to other cells in each preparation was increased by differential centrifugation over a continuous gradient.Collagenase was extracted from the fractions in which granulocytes were concentrated and the activity assayed by the radioactive fibril method.There was at least as much collagenase in the eosinophil‐enriched extracts as in the neutrophil‐enriched extracts.It is postulated that eosinophil collagenase may have a function in the remodelling of newly‐synthesised collagen during the post‐inflammatory phase of healing, since eosinophil leucocytes appear in significant numbers within the connective tissue during this phase. This suggests a different role for eosinophil collagenase than that for neutrophil collagenase, since neutrophils are present only in the early stages of inflammation, when collagen is being degraded.
THE IDENTIFICATION AND ULTRASTRUCTURE OF MACROPHAGES FROM THE MAMMARY GLAND OF THE EWE
Authors: Lee CS , Outteridge PM 
Published: November 2007

SummaryCells in the secretion of involuting and non‐lactating mammary glands of the ewe were studied. Light microscopy studies revealed that the majority of the cells were mononucleated, but it was impossible to distinguish macrophages from sloughed epithelial cells. Electron microscopy studies showed that the majority of die cells were macrophages and that they phagocytosed polystyrene latex spheres. Very few epithelial cells were found and they were distinguished from macrophages by numerous microfilaments and blunt microvilli. Epithelial cells could he further distinguished from macrophages by the presence of tight junctions.Tissue culture of cells in secretion of mammary glands revealed the predominant cell type to be the macrophage. After 3 days in culture these macrophages formed multinucleated giant cells which contained acid‐phosphatase granules. Fluorescein‐labelled antiserum prepared against the cell cultures, stained cells in the lumens of alveoli and duets, but not epithelial cells, in frozen sections of mammary tissue.The study confirms previous findings that the large majority of cells from mammary glands in late involution are macrophages. It also points to the usefulness of non‐lactating mammary glands as a source of sheep and cattle macrophages.
MECHANISM OF THYROID ALLOGRAFT REJECTION
Authors: Lafferty KJ , Bootes A , Killby VAA , Burch W 
Published: November 2007

SummaryBalb/c thyroids, held in organ culture for 26 days, survive and function as well as isografts for > 100 days in CBA recipients. Uncultured allografts are totally rejected by 20 days after transplantation. Prolonged allograft survival can also be achieved by the treatment of donor animals with cyclophosphamide prior to harvesting tissues for transplantation. These allografts do not survive as welt as 26 day cultured allografts, but cyclophosphamide pretreatment reduces the culture time required to achieve indefinite survival to 7 days.The provision of an allogeneic (LD) stimulus by thyroid tissue that is I‐region incompatible with the host does not facilitate the rejection of a tolerated cultured allograft. However, activation of the host immune system by an uncultured graft syngeneic to a tolerated cultured allograft leads to the chronic rejection of the cultured transplant.The transfer of a tolerated cultured allograft back to its strain of origin induces an acute inflammatory reaction that causes tissue damage within the transplant but does not lead to the total destruction of the tissue.
ISOLATED ISLET TRANSPLANTATION IN EXPERIMENTAL DIABETES
Authors: Gray Bruce N , Watkins Elton 
Published: November 2007

SummaryPancreatic islets have been isolated from the exocrine pancreas of inbred rats by the collagenase digestion method. Transplantation of isolated islets into the portal venous system of streptozotocin‐diabetic recipients resulted in complete abrogation of the diabetic state us measured by non‐fasting serum glucose levels, 24 h urinary output, rate of weight gain and glucose tolerance test. Transplantation to other sites resulted in less than optimal survival and function of islets. Allogeneic islets, transplanted across weak histocompatibility barriers, can survive and function for prolonged periods of time when transplant recipients are immunosuppressed with antilymphocyte serum (ALS). Recipients of allogeneic islets, after a period of immunosuppression with ALS, become permanently tolerant to the allografted islets and to subsequent skin grafts from similar allogeneic donors. Allografted islets are able to prevent the occurrence of diabetic renal and ophthalmic changes that occur in control diabetic animals which had not undergone transplantation.
LYMPHOCYTE‐LIKE CELLS OF THE TUNICATE, PYURA STOLONIFERA: BINDING OF LECTINS, MORPHOLOGICAL AND FUNCTIONAL STUDIES
Authors: Warr Gregory W , Decker Janet M , Mandel Thomas E , DeLuca Dominick , Hudson Richard , Marchalonis John J 
Published: November 2007

SummaryIn vitro investigations were carried out to determine whether lymphocyte‐like (small round) cells of the tunicate Pyura stolonifera react to allogeneic cells and mitogens in a manner comparable to that of vertebrate immunocytes. The lymphocyte‐like cells possessed receptors for concanavalin A, wheat germ agglutinin and soybean lectin as shown by binding of radioiodinated lectins in scintillation counting and autoradiographic assays. This binding did not induce mitogenesis. Mixtures of cells of P. stolonifera individuals taken from the same or distinct localities did not show enhanced DNA synthesis when assayed at time intervals ranging from 3 to 10 days. The small round cells of this and other tunicates are not completely similar to vertebrate lymphocytes in morphology. Our observations support the concept that these cells are not directly homologous to immunologically competent vertebrate lymphocytes, but may serve as haemopoietic stem cells as proposed by others (Endean, 1954; Freeman, 1970).
SURFACE IMMUNOGLOBULINS, A POSSIBLE MECHANISM FOR THE PERSISTENCE OF TRYPANOSOMA LEWISI IN THE CIRCULATION OF RATS
Authors: Ferrante A , Jenkin CR 
Published: November 2007

SummaryThe results presented below show that the dividing and adult forms of T. lewisi share common antigens and indicate that the persistence of adult forms in the circulation of rats immune to reinfection is not due to a change in surface antigens as has been postulated. Using a rabbit anti‐rat immunoglobulin serum, the presence of rat immunoglobulins on the surface of adult trypanosomes could be demonstrated. These immunoglobulins were not complement‐fixing or opsonic. It is suggested that these immunoglobulins are responsible for the persistence of the adult forms in the circulation of the rat.
MURINE CUTANEOUS LEISHMANIASIS: DISEASE PATTERNS IN INTACT AND NUDE MICE OF VARIOUS GENOTYPES AND EXAMINATION OF SOME DIFFERENCES BETWEEN NORMAL AND INFECTED MACROPHAGES
Authors: Handman Emanuela , Ceredig Rhodri , Mitchell Graham F 
Published: November 2007

SummaryThe course of the disease, cutaneous leishmaniasis, caused by the intracellular protozoan parasite Leishmania tropica, differs markedly amongst various common inbred mouse strains. After intradermal injection of 1 × 106 promastigotes to young female specific pathogen‐free (SPF) derived mice, persistent infection characterized by an expanding ulcerous lesion is seen in BALB/c and DBA/2 mice. In the strains CBA/H, C3H/He and A/J, lesions resolve within 8 weeks, and in C57Bl/6 mice no real lesion typical of cutaneous leishmaniasis develops at the injection site. NZB mice are highly resistant. Macrophages harvested from the thioglycollate‐stimulated peritoneal cavity of NZB and C57Bl/6 mice appear to differ from macrophages of the other mouse strains in not supporting multiplication of L. tropica organisms in vitro. Nevertheless, hypothymic nude (nu/nu) mice of C57B1/6 genotype, as well as CBA/H‐nu/nu and BALB/c‐nu/nu mice, develop large lesions with metastases to other cutaneous and visceral locations. In the intact mice in which infection resolves spontaneously, resistance to reinfection is complete. Using mouse antipromastigote sera and an indirect fluorescent antibody test in carefully controlled experiments, L. tropica antigens were detected on in vitro infected macrophages of both highly susceptible BALB/c and relatively resistant CBA/H genotypes. After incubation with a crude soluble antigen preparation from cultured promastigotes, infected macrophages of both genotypes) in being unable to sensitize syngeneic recipients for a delayed‐type hypersensitivity response to that antigen. When infected and uninfected macrophages were used as “blocking cell” in an in vitro alloreactive cytotoxic T cell system involving cells from congenic mice, evidence was obtained for reduced H‐2d expression on infected macrophages of the susceptible mouse strain, BALB/c. The data in this model system of cutaneous leishmaniasis raise the possibility that genetic susceptibility is associated with both a permissive macrophage and defective T cell recognition of parasite antigens on infected macrophage. Defective recognition may be the result of reduced functional expression of H‐2d antigens on infected BALB/c macrophages required for efficient recognition by syngeneic T cells of one or more sub‐populations.
IgG1 HYPERGAMMAGLOBULINAEMIA IN CHRONIC PARASITIC INFECTIONS IN MICE: MAGNITUDE OF THE RESPONSE IN MICE INFECTED WITH VARIOUS PARASITES
Authors: Chapman Colin B , Knopf Paul M , Hicks J Douglas , Mitchell Graham F 
Published: November 2007

SummaryMice chronically infected with 3 metazoan and 1 protozoan parasite contain in their circulation levels of IgG1 which are increased over the levels in uninfected mice by at least 10×. In the case of infection with the larval cestode, Mesocestoides corti. the serum IgG1 concentration can reach > 50 mg/ml and, with a half‐life of < 2 days, the number of cells engaged in IgG1 production is approximately 2 × 108. The IgG1 hypergammaglobulinaemia is not seen in infected hypothymic nude mice. Biosynthetic labelling studies with organ and tissue cultures established that in two of the chronic infections the organs principally involved in IgG1 synthesis were those pathologically involved or those “in line” for antigen capture: i.e. liver and spleen in the case of M. corti which is located in the liver and the peritoneal cavity, and various intestinal lymph nodes in the case of the gut‐dwelling nematode, Nematospiroides dubius. This apparently exaggerated response to chronic parasitic infection is of interest simply because of the potential magnitude of the effect and the fact that it involves an Ig isotype with very poorly defined biological function.
MORPHOMETRIC ANALYSIS OF RAT EXTENSOR DIGITORUM LONGUS AND SOLEUS MUSCLES
Authors: Davey DF , Wong SYP 
Published: November 2007

SummaryThe ultrastructure of extensor dtgitorum logus (EDL) and soleus muscles from two groups of Wistar rats obtained from different colonies has been examined both qualitatively and morphometrically. Compared to soleus. EDL fibres are richer in sarco‐plasmic reticulum, but contain fewer mitochondria, lipid droplets and nuclei. The quantities of these organelles and related surface volume ratios in single morphometric samples varied, reflecting the heterogeneity of fibre ultrastructure within the muscles. There were significant differences in many features quantified between the two groups of rats; these differences present a problem in comparing different published reports but, fortunately, the EDL/soleus ratios were similar in both groups. Within each group, the fibre fractions occupied by mitochondria and sarcoplasmic reticulum found in the morphometric samples were reciprocally related. The different amounts of sarcoplasmic reticulum in the two muscles is insufficient to explain the different calcium pumping capacities observed by Briggs, Poland and Solaro (1977), suggesting a control at the level of the pump protein synthesis.
SKELETAL MUSCLE LIPIDS IN NORMAL AND DYSTROPHIC MICE
Authors: Pearce PH , Kakulas BA 
Published: November 2007

SummaryThe lipids of muscle from normal and dystrophic mice of the Bar Harbor strain C57BL/6J were investigated with particular reference to the Fatty acid composition of the neutral lipids and phospholipids. Triglyceride, which together with cholesterol comprised most of the neutral lipid fraction, showed no significant changes in Fatty acid composition. There was no significant change in the amount of total phospholipid phosphorus in dystrophic muscle, hut analyses of the levels of individual phospholipids showed a decrease of 9% in phosphatidylcholine. In both phosphatidylcholine and ethanolamine phosphoglycerides, large decreases were observed in the proportion of the fatty acid 16:0, while 18:0 and 18:1 increased significantly. In phosphatidylcholine 18:2 also increased, and a decrease occurred in 22:6 in ethanolamine phosphoglycerides, Sphingomyelin showed increases in 16:0, 23:0 and 24:1 and decreases in 18:0 and 18:1. The other phospholipid Fractions showed less remarkable changes, with a significant increase in 18:0 in lysophosphatidylcholine and a decrease in 16:0 in cardiolipin.
DISTRIBUTION OF THE SIX α1‐ANTITRYPSIN (PI) SUBTYPES FROM A SAMPLE OF BLOOD DONORS
Authors: Mulley John C 
Published: November 2007

SummaryThe PI M phenotype of α1‐antitrypsin was classified into six subtypes determined by three alleles: PI*MI, PI*M2 and PI*M3. Phenotypes were classified by isoelectric focusing and their distribution agreed closely with Hardy‐Weinberg expectations. The proportion of heterozygotes was 53%. which more than trebles the heterozygosity without subtyping, and is comparable to a recent estimate from U.S. whites.