In vitro growth inhibition of Plasmodium falciparum by retinol at concentrations present in normal human serum

The colloidal dye lithium carmine was added in vitro to normal human serum. Electrophoretic experiments showed that the dye was associated mainly with α2-globulins, small amounts with the albumin and only traces with the γ-globulins. The main complex was eluted with the macroglobulin peak obtained by gel filtration on Sephadex G-200 and sedimented in the heavy fraction on density gradient ultracentrifugation. The dye-protein complex could be precipitated with an antiserum specific for a2-macroglobulin. Gel filtration of a solution of pure a2-macroglobulin, to which lithium carmine was added, demonstrated that the dye was bound to this protein.

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Human-human hybridomas secreting monoclonal antibodies to the Mr 195,000 Plasmodium falciparum blood stage antigen.

Journal of Experimental Medicine ◽

10.1084/jem.163.1.179 ◽

1986 ◽

Vol 163 (1) ◽

pp. 179-188 ◽

Cited By ~ 18

Author(s):

R Schmidt-Ullrich ◽

J Brown ◽

H Whittle ◽

P S Lin

Keyword(s):

Plasmodium Falciparum ◽

Growth Inhibition ◽

Protective Immunity ◽

Lymphoblastoid Cell Line ◽

In Vitro Growth ◽

Human Lymphoblastoid Cell ◽

Immune Precipitation ◽

Human Lymphoblastoid Cell Line ◽

Donor Lymphocytes

Using the human lymphoblastoid cell line, GM 4672, and PBL of Gambian adults immune to Plasmodium falciparum (Pf) malaria, we have produced human-human hybridomas and selected those that produce mAb against Pf antigens. The fusion frequency, using PWM-stimulated donor lymphocytes was between 6.8 X 10(-5) and 1.5 X 10(-6). Using immune fluorescence, immune precipitation, and Pf in vitro growth inhibition, we cloned four hybridomas that reacted with the Pf Mr 195,000 schizont/merozoite protein. The differences in proteins immune precipitated and in growth inhibition indicate that, during development of protective immunity against Pf malaria, a spectrum of antibodies is produced reacting with different epitopes on the same antigen. Only a portion of these antibodies exhibits biological activity, suggesting that the recognition of certain epitopes is required for the development of a protective immune response.

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Stimulation by serum of aldosterone production from rat adrenal glomerulosa cells in vitro: relationships to K+, serotonin and angiotensin II

Acta Endocrinologica ◽

10.1530/acta.0.0970231 ◽

1981 ◽

Vol 97 (2) ◽

pp. 231-242 ◽

Cited By ~ 2

Author(s):

F. A. O. Mendelsohn ◽

Christine D. Kachel

Keyword(s):

Angiotensin Ii ◽

Human Serum ◽

Normal Subjects ◽

Normal Human Serum ◽

Rpmi Medium ◽

High K ◽

Aldosterone Production ◽

Normal Human ◽

Glomerulosa Cells

Abstract. Normal human serum markedly stimulated aldosterone production from rat adrenal glomerulosa cells incubated in Krebs Ringer bicarbonate medium (KRBGA). The effect was dose-related. In [K+] 3.6 mm KRBGA medium, serum stimulated aldosterone output to higher levels than those produced by maximal doses of serotonin (5 HT), angiotensin II (AII) or high [K+] (8.4 mm). Cells maximally stimulated by high [K+], 5 HT or AII in KRBGA medium were further stimulated by serum. The angiotensin analogue, [Sar1, Ala8]-AII abolished the effect of AII but not that of high [K+] or serum. Basal and ACTH-stimulated corticosterone outputs of rat fasciculata cells were not significantly affected by sera known to stimulate glomerulosa cells. Aldosterone stimulating activity of serum was dialysable and fully recovered in a serum ultrafiltrate. The serotonin blockers methysergide and metergoline abolished the aldosterone stimulating activity of serum but also depressed basal aldosterone output and methysergide reduced K+-stimulated output. Chymotrypsin digestion abolished the aldosterone stimulating activity of AII but not that of serotonin or serum. 5 HT concentration of sera was measured and found to be near the threshold for aldosterone stimulation. Sodium loading and depletion of 4 normal subjects did not consistently modify the aldosterone stimulating activity of their sera. In a supplemented medium (RPMI 1640), basal and K+-stimulated aldosterone outputs were higher than in KRBGA medium. Under these conditions serum stimulated aldosterone output in normal [K+] medium but only marginally in high [K+] medium. In RPMI medium, serum did not further stimulate cells maximally stimulated with serotonin. Serum appears to stimulate aldosterone production from glomerulsoa cells by two different mechanisms: One is probably due to a serotonin-like substance. A separate effect of serum, seen only in KRBGA medium, is to enhance aldosterone output of glomerulosa cells maximally stimulated by K+, 5 HT or AII.

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The effect of normal human serum on the mouse trypanosome Trypanosoma musculi in vitro and in vivo

Experimental Parasitology ◽

10.1016/j.exppara.2017.12.005 ◽

2018 ◽

Vol 184 ◽

pp. 115-120

Author(s):

Xuan Zhang ◽

Xiao-Kun Hong ◽

Su-Jin Li ◽

De-Hua Lai ◽

Geoff Hide ◽

...

Keyword(s):

Human Serum ◽

Normal Human Serum ◽

Normal Human

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Development of fluorescent Plasmodium falciparum for in vitro growth inhibition assays

Malaria Journal ◽

10.1186/1475-2875-9-152 ◽

2010 ◽

Vol 9 (1) ◽

pp. 152 ◽

Cited By ~ 65

Author(s):

Danny W Wilson ◽

Brendan S Crabb ◽

James G Beeson

Keyword(s):

Plasmodium Falciparum ◽

Growth Inhibition ◽

In Vitro Growth

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Identification of a trypanocidal factor againstTrypanosoma equiperdumin normal human serum

Parasitology ◽

10.1017/s0031182000061485 ◽

1989 ◽

Vol 98 (3) ◽

pp. 401-407 ◽

Cited By ~ 11

Author(s):

G. Verducci ◽

S. Perito ◽

R. Rossi ◽

E. Mannarino ◽

F. Bistoni ◽

...

Keyword(s):

Human Serum ◽

Gel Filtration ◽

Density Lipoprotein ◽

Natural Antibodies ◽

Normal Human Serum ◽

Mouse Serum ◽

Trypanocidal Activity ◽

Normal Human

SUMMARYNormal human serum (HS) contains trypanolytic activity and agglutinins toTrypanosoma equiperdum, while such activities are not found in sera from a range of animals susceptible to infection. HS given toT. equiperdum-infected mice caused a rapid decrease in the number of circulating trypanosomes and protection from lethal infection. Trypanolytic activity of human serum was found to be associated, after DEAE chromatography and Sephadex G-200 gel filtration, with the fraction containing 19S antibodies. Immunofluorescence assays confirmed a binding of human IgM and C1qcomplement component onto the surface ofT. equiperdum. Anti-T. equiperdumactivity of HS was specifically directed toT. equiperdumsurface components and not to some mouse serum components adsorbed on parasites during the growth in the host, because HS adsorbedin vivoin CD-1 mice retained full protective and agglutinating properties. Trypanocidal activity appears in human serum about the 7th month after birth and persists until late in life. On the contrary, human purified high-density lipoprotein had no significantin vitroorin vivotrypanocidal activity. In conclusion, strong natural anti-T. equiperdumactivity in human serum was mainly mediated by natural antibodies of the IgM class. The presence of natural IgM active againstT. equiperdumin HS could represent one of the natural mechanisms of resistance of refractory hosts against trypanosome infections. This phenomenon provides further evidence that host specificity of trypanosomes may be partly conditioned by the presence of natural antibodies.

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Influence of the Length of the Lipooligosaccharide α Chain on Its Sialylation in Neisseria meningitidis

Infection and Immunity ◽

10.1128/iai.70.1.407-411.2002 ◽

2002 ◽

Vol 70 (1) ◽

pp. 407-411 ◽

Cited By ~ 9

Author(s):

Chao-Ming Tsai ◽

George Kao ◽

Peixuan Zhu

Keyword(s):

Neisseria Meningitidis ◽

Human Serum ◽

Steric Hindrance ◽

Normal Human Serum ◽

Normal Human ◽

Α Chain

ABSTRACT The sialylation of lipooligosaccharide (LOS) in Neisseria meningitidis plays a role in the resistance of the organism to killing by normal human serum. The length of the α chain extending out from the heptose I [Hep (I)] moiety of LOS influenced sialylation of N. meningitidis LOS in vitro and in vivo. The α chain required a terminal Gal and a trisaccharide or longer oligosaccharide to serve as an acceptor for sialylation. The disaccharide lactose (Galβ1-4Glc) in the α chain of immunotype L8 LOS could not function as an acceptor for the sialyltransferase, probably due to steric hindrance imposed by the neighboring Hep (II) with phosphorylethanolamine and another group attached.

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Comparison of the hemagglutination inhibition assay kit for erythropoietin (ESF) with the fetal mouse liver cell bioassay in vitro

Blood ◽

10.1182/blood.v55.6.955.bloodjournal556955 ◽

1980 ◽

Vol 55 (6) ◽

pp. 955-959

Author(s):

G de Klerk ◽

RJ Vet ◽

PC Rosengarten ◽

R Goudsmit

Keyword(s):

Human Serum ◽

Liver Cell ◽

Hemagglutination Inhibition ◽

Mouse Liver ◽

Normal Human Serum ◽

Fetal Mouse ◽

Mouse Liver Cell ◽

Fetal Mouse Liver ◽

Normal Human

The commercially available hemagglutination inhibition (HAI) assay kit for erythropoietin (ESF) was compared with the fetal mouse liver cell (FMLC) bioassay. No correlation was obtained ESF levels determined by both methods in a variety of pathologic sera. The HAI kit showed a great batch variability. Significant immunoreactivity was found in those fractions of a normal human serum and a human urinary ESF preparation that were not active in the FMLC bioassay. A very poor recovery of immunoreactivity was found when the international reference preparation for erythropoietin (second IRPE) was added to a normal human serum.

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On the Complex Formation of Antithrombin III with Thrombin

Thrombosis and Haemostasis ◽

10.1055/s-0038-1649075 ◽

1973 ◽

Vol 30 (02) ◽

pp. 280-283 ◽

Cited By ~ 4

Author(s):

B Binder

Keyword(s):

Complex Formation ◽

Human Serum ◽

Blood Coagulation ◽

Antithrombin Iii ◽

Normal Human Serum ◽

Molecular Weights ◽

At Iii ◽

Normal Human

SummaryBased on gelfiltration studies, the part of AT III which becomes bound to thrombin during the process of in vitro blood coagulation was calculated to be about 40% of total AT III. Complexes consisting of one AT III and one thrombin molecule could not be detected while fractions corresponding to molecular weights of about 190,000 Dalton show AT III as well as thrombin activities. The AT III - thrombin complex in normal human serum consists, therefore, of either 2 AT III and 2 thrombin molecules or of one AT III and 4 thrombin molecules.

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