scholarly journals PURIFICATION OF AN INFLUENZA VIRUS SUBSTRATE, AND DEMONSTRATION OF ITS COMPETITIVE ANTAGONISM TO APPLE PECTIN

1949 ◽  
Vol 89 (1) ◽  
pp. 11-22 ◽  
Author(s):  
D. W. Woolley
Keyword(s):  
Influenza Virus ◽  
Calcium Ions ◽  
Water Soluble ◽  
Rabbit Serum ◽  
Normal Rabbit Serum ◽  
Apple Pectin ◽  
Alkaline Extract ◽  
Competitive Antagonism ◽  
Soluble Material

A substance was demonstrated in erythrocytes which antagonized the inhibiting effect of apple pectin on influenza virus hemagglutination. This substance was purified and found to be a water-soluble material, rather labile, and with some properties which suggested that it contained a polysaccharide. It was destroyed in vitro by highly purified preparations of the virus. It occurred in greatest amount in human erythrocytes and to a lesser extent in the red cells of species not susceptible to the virus. It was also found in normal rabbit serum. Calcium ions were found to be essential to the action of apple pectin in causing inhibition of virus hemagglutination. A second substance was purified from an alkaline extract of erythrocytes, and shown likewise to have an effect antagonistic to that of pectin. However, this latter material was not destroyed by the virus, and seemed to owe its effect to the binding of calcium ions.

Release of bioactive ACTH by perifused human placenta at early and late gestation

1993 ◽  
Vol 136 (2) ◽  
pp. 345-353 ◽  
Author(s):  
B. J. Waddell ◽  
P. J. Burton
Keyword(s):  
Human Placenta ◽  
Late Gestation ◽  
Rabbit Serum ◽  
Maximal Response ◽  
Normal Rabbit Serum ◽  
Apparent Difference ◽  
Adrenocortical Cells ◽  
Adult Rats ◽  
Constant Rate

ABSTRACT This study assessed whether bioactive ACTH is released by the human placenta during perifusion in vitro at early and late gestation. Human placental villous fragments from early (8–12 weeks) and late (38–40 weeks) gestation were perifused at a constant rate for 6·5 h. To assess ACTH-like bioactivity released by this tissue, the perifusion effluent was redirected through adjacent chambers containing freshly dispersed adrenocortical cells obtained from adult rats. Baseline secretion of corticosterone by these adrenocortical cells averaged 95±26 (s.e.m.) fmol/min, and this increased at least fivefold (P <0·01, two-way ANOVA) in response to placental effluent at early and late gestation. The magnitude of this increase, expressed as a percentage of the maximal response to a subsequent stimulus with ACTH(1–24), was similar for placentas obtained at early (41 ± 12% of maximal response) and late (42 ± 17%) gestation. Immunoreactive (I)-ACTH was readily detectable in placental effluent from all preparations (5·5±2·3 fmol/min per g tissue), and there was no apparent difference with stage of gestation. To determine whether all of the ACTH-like bioactivity released by the placenta was attributable to I-ACTH, a second series of placental/adrenal perifusions was conducted. In these, I-ACTH was selectively removed from placental effluent by immunoneutralization, and the residual bioactivity measured. Immunoneutralization involved preincubation of placental effluent with ACTH antiserum (1:100), and preincubation with normal rabbit serum (NRS) served as a control. Preincubation with ACTH antiserum, but not with NRS, resulted in a marked reduction in ACTH-like bioactivity present in placental effluent at both early (P <0·01, paired t-test) and late (P <0·05) gestation. This inhibition was significantly more effective (P <0·05, unpaired t-test) at early than at late gestation. Overall, these data establish that the human placenta can release bioactive ACTH-like activity at both early and late gestation, and that much, but not all, of this bioactivity is directly attributable to I-ACTH. These findings clearly demonstrate a potential role for placental ACTH in directly influencing the maternal and/or fetal hypothalamic-pituitary-adrenal axes during human pregnancy. Journal of Endocrinology (1993) 136, 345–353

scholarly journals THE NATURE OF THE VIRUS RECEPTORS OF RED CELLS

1948 ◽  
Vol 87 (4) ◽  
pp. 315-328 ◽  
Author(s):  
George K. Hirst
Keyword(s):  
Influenza Virus ◽  
Type A ◽  
Red Cells ◽  
Rabbit Serum ◽  
Normal Rabbit Serum ◽  
Virus Inhibitor ◽  
Virus Receptors

Evidence has been offered that influenza virus which has been heated at 56°C. for 30 or more minutes loses some of its capacity to agglutinate red cells and may completely lose its power to elute from cells on which it has been adsorbed. Such heat-inactivated virus does not possess the capacity to destroy the virus inhibitor in normal rabbit serum and this appears to be the explanation of the higher agglutinin inhibitory levels obtained with serum and heated virus as compared with serum and untreated virus. The heat-inactivated virus can be used to measure the inhibitor substance in normal rabbit serum. By two different methods it has been demonstrated that the inhibitor is destroyed in the presence of unheated influenza virus, as measured by inhibition titrations with virus inactivated at 56°C. The destruction of inhibitor by virus of either type A or B can be measured by virus of either type with similar results.

scholarly journals Antiviral Activity of Aspalathus linearis against Human Influenza Virus

2017 ◽  
Vol 12 (4) ◽  
pp. 1934578X1701200 ◽  
Author(s):  
Ratika Rahmasari ◽  
Takahiro Haruyama ◽  
Siriwan Charyasriwong ◽  
Tomoki Nishida ◽  
Nobuyuki Kobayashi
Keyword(s):  
Influenza Virus ◽  
Influenza A Virus ◽  
Influenza A ◽  
Time Course ◽  
Influenza Viruses ◽  
Replication Process ◽  
Human Influenza Virus ◽  
Alkaline Extract ◽  
Aspalathus Linearis

Influenza A viruses are responsible for annual epidemics and occasional pandemics, which cause significant morbidity and mortality. The limited protection offered by influenza vaccination, and the emergence of drug-resistant influenza strains, highlight the urgent need for the development of novel anti-influenza drugs. However, the search for antiviral substances from the library of low molecular weight chemical compounds is limited. Thus, because of their natural diversity and accessibility, plants or plant-derived materials are rapidly becoming valuable sources for the discovery and development of new antiviral drugs. In this study, crude extracts of Aspalathus linearis, a plant reported to have anti-HIV activity, were evaluated in vitro for their activity against the influenza A virus. Of the extracts tested, an alkaline extract of Aspalathus linearis demonstrated the strongest inhibition against influenza A virus and could also inhibit different types of influenza viruses, including Oseltamivir-resistant influenza viruses A and B. Our time course of addition studies indicated that the alkaline extract of Aspalathus linearis exerts its antiviral effect predominantly during the late stages of the influenza virus replication process.

Partial purification of antigens collected during in vitro cultivation of the larval stages of Taenia pisiformis

Parasitology ◽  
1976 ◽  
Vol 72 (3) ◽  
pp. 269-279 ◽  
Author(s):  
M. D. Rickard ◽  
J. C. Katiyar
Keyword(s):  
Protective Immunity ◽  
Culture Medium ◽  
Serum Proteins ◽  
Skin Tests ◽  
Rabbit Serum ◽  
Partial Purification ◽  
In Vitro Cultivation ◽  
Normal Rabbit Serum ◽  
Skin Reactions

SummaryLarvae of Taenia pisiformis were cultured in vitro in medium containing 2·5, 5 or 20% (v/v) of normal rabbit serum (NRS). Greatest development occurred in 20% NRS, and the potency of antigens collected in medium from each culture tested by intradermal (i/d) skin tests in infected rabbits paralleled the in vitro growth rate of larvae. ‘Culture’ antigens from 5% NRS stimulated good immunity in rabbits to a challenge infection with T. pisiformis eggs, although they were poorly reactive in skin tests.T. pisiformis larvae were also cultured in 10% (v/v) of nitrates of serum reduced to one-half of its volume by passage through 300 000 MW cut oif (XM300F) or 100000 MW cut off (XM100F) ultrafiltration membranes. Larvae cultured using XM300F had growth rates comparable with those cultured in 20% NRS, and the antigens released into the culture medium had equal potency in i/d tests and in stimulating protective immunity in rabbits. Larvae did not develop in XM100F orproduce skin-reactive or protective antigens.Crude ‘culture’ antigen from cultures in 20% NRS was separated into 4 fractions by nitration on Sephadex G200. All of these fractions gave i/d skin reactions in infected rabbits. Fraction 3 (F3) was the most active, but was shown by acrylamide gel electrophoresis and immunoelectrophoresis to be highly contaminated with rabbit serum proteins. F3 was separated into fractions on DEAE-Sephadex A50, and the third fraction from this was as active as the original culture medium in i/d skin tests, but had only 5% of the original protein concentration. Electrophoresis demonstrated few serum contaminants, and 2 indistinct protein bands that were not present in a similar fraction of NRS.Neither Sephadex G200 F3 nor DEAE-Sephadex F3 stimulated protective immunity in rabbits, suggesting that antigens stimulating immunity against the establishment of T. pisiformis in rabbits and those provoking cell-mediated immune reactions may be different.

scholarly journals IMMUNE RESPONSE OF RABBITS TO INJECTION OF PLASMODIUM KNOWLESI

1939 ◽  
Vol 70 (2) ◽  
pp. 131-139 ◽  
Author(s):  
Monroe D. Eaton ◽  
L. T. Coggeshall
Keyword(s):  
Immune Response ◽  
Plasmodium Knowlesi ◽  
Conclusive Evidence ◽  
Red Cells ◽  
Rabbit Serum ◽  
Normal Rabbit Serum ◽  
Passive Protection ◽  
Normal Monkey ◽  
Protective Antibodies

Specific complement-fixing antibodies are produced in the serum of rabbits in response to injections of living or dead Plasmodium knowlesi. Sera from rabbits receiving injections of either parasitized or normal monkey erythrocytes are parasiticidal in vitro for P. knowlesi. Because absorption of parasiticidal rabbit sera with normal monkey erythrocytes abolishes the parasiticidal effect, it is concluded that the effect is largely due to an antibody to the red cells. Normal rabbit serum is not parasiticidal. Experiments on passive protection in monkey malaria with serum from rabbits which have received intraperitoneal injections of living or dead P. knowlesi yield no conclusive evidence that protective antibodies are formed.

Studies on the growth of 5-day-old rabbit blastocysts in vitro

Development ◽  
1965 ◽  
Vol 13 (1) ◽  
pp. 83-95
Author(s):  
Joseph C. Daniel
Keyword(s):  
Blastocyst Stage ◽  
Culture Conditions ◽  
Rabbit Serum ◽  
Young Rabbit ◽  
Normal Rabbit Serum ◽  
Excellent Growth ◽  
Growth Promoting ◽  
Initial Medium ◽  
Made In

Rabbit embryos at the early blastocyst stage (5 days post coitum) do not grow well in vitro. The present studies were undertaken for the purpose of defining some of the components of the medium that are optimal for growth of young rabbit blastocysts under culture conditions. Preliminary studies showed that the cell culture medium F10 (Ham, 1963a) supported excellent growth of a variety of rabbit cells in vitro. Rabbit blastocysts would grow, although not at the normal rate, in F10 supplemented with 15 per cent, normal rabbit serum. F10R15 was therefore selected as the initial medium to which additions or alterations were made in an attempt to perfect its blastocyst growth-promoting qualities. It should be clearly understood that throughout this paper the word ‘growth’, used in reference to rabbit blastocysts, means an increase in blastocyst volume without prejudice to the issue of whether or not the total volume or mass of living cells is also increasing.

scholarly journals INTERACTIONS BETWEEN RABBIT POLYMORPHONUCLEAR LEUCOCYTES AND STAPHYLOCOCCI

1959 ◽  
Vol 110 (3) ◽  
pp. 419-443 ◽  
Author(s):  
Zanvil A. Cohn ◽  
Stephen I. Morse
Keyword(s):  
Bacterial Species ◽  
Rabbit Serum ◽  
Normal Rabbit Serum ◽  
Polymorphonuclear Leucocytes ◽  
Bacterial Inactivation ◽  
Intracellular Killing ◽  
Positive Strain ◽  
Simultaneous Evaluation ◽  
Coagulase Positive Staphylococci

A method has been described for the study in vitro of leucocyte-bacteria interactions which permits the simultaneous evaluation of both phagocytosis and intracellular bacterial inactivation. Employing this technique, the fate and localization of staphylococci in homogeneous suspensions of rabbit polymorphonuclear leucocytes have been studied. Coagulase-positive strains of S. aureus were not efficiently ingested in the presence of normal rabbit serum. In contrast, coagulase-negative strains of S. albus were rapidly engulfed and inactivated. Immune sera prepared against a coagulase-positive strain enhanced the the ingestion of the homologous organism as well as of three heterologous strains of S. aureus. Following phagocytosis, prompt intracellular killing of S. aureus occurred. The thermostable opsonins in immune sera reacted only with strains of S. aureus. A comparison between polymorphonuclear leucocytes obtained from normal and immune animals revealed no differences in their ability either to ingest or kill coagulase-positive staphylococci. Studies with other bacterial species are presented to illustrate: (a) phagocytosis followed by intracellular inactivation; (b) phagocytosis followed by intracellular survival; and (c) the absence of phagocytosis.

Nonadrenergic noncholinergic neurotransmitter of feline trachealis: VIP or nitric oxide?

1993 ◽  
Vol 74 (1) ◽  
pp. 31-39 ◽  
Author(s):  
J. T. Fisher ◽  
J. W. Anderson ◽  
M. A. Waldron
Keyword(s):  
Nitric Oxide ◽  
Muscle Tone ◽  
Passive Immunization ◽  
Electrical Field Stimulation ◽  
Isometric Tension ◽  
Normal Serum ◽  
Rabbit Serum ◽  
Normal Rabbit Serum ◽  
Response Curves

We tested the hypothesis that vasoactive intestinal peptide (VIP) or nitric oxide (NO) is the nonadrenergic noncholinergic (NANC) neurotransmitter in feline trachealis. Isometric tension was measured in trachealis (open or closed tracheal rings) in vitro. Propranolol (10 microM) and atropine (1 microM) were present throughout the experiment, and smooth muscle tone was increased to 60–90% maximal with 5-hydroxytryptamine. We used three methodologies to reduce the relaxation function of VIP, which in turn should reduce NANC-mediated relaxation. 1) The putative VIP antagonist peptide T (10 microM) did not affect VIP concentration-response curves or electrical field stimulation- (EFS) induced NANC responses. 2) Incubation of tissue in specific VIP antiserum (16 h at 4 degrees C) did not reduce EFS-induced NANC relaxations relative to tissue incubated in normal rabbit serum (P > 0.05). On the basis of our passive immunization techniques, it is not possible to absolutely reject VIP as the NANC transmitter. We speculate that nonspecific peptidases present in normal serum and VIP antiserum reduce EFS-induced responses similarly. 3) VIP desensitization, confirmed by a significant rightward shift (P < 0.01) in the VIP concentration-response curve, was achieved by exposing tissues (n = 11) to 1.0 microM VIP for 30 min. Desensitization did not reduce the EFS-induced NANC relaxatory response (P < 0.05) compared with control tissues, suggesting that VIP is not the NANC mediator.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals THE CHEMOTACTIC EFFECT OF MIXTURES OF ANTIBODY AND ANTIGEN ON POLYMORPHONUCLEAR LEUCOCYTES

1962 ◽  
Vol 115 (3) ◽  
pp. 453-466 ◽  
Author(s):  
Stephen Boyden
Keyword(s):  
Chemotactic Activity ◽  
Rabbit Serum ◽  
Normal Rabbit Serum ◽  
Polymorphonuclear Leucocytes ◽  
Heat Stable ◽  
Motile Cells ◽  
Fresh Serum ◽  
In Vitro Technique ◽  
Chemotactic Effect

An in vitro technique is described for assessing the chemotactic activity of soluble substances on motile cells. Antibody-antigen mixtures when incubated (37°C) in medium containing fresh (i.e. non-inactivated) normal rabbit serum exert a strong chemotactic effect on rabbit polymorphonuclear leucocytes. Results are described which indicate that, when antibody-antigen complexes are incubated (37°C) in fresh serum, a heat-stable (56°C) substance (or substances) is produced which acts directly as a chemotactic stimulus on the polymorphs. This heat-stable chemotactic substance is not produced when antibody-antigen complexes are incubated in serum which has been heated at 56°C for 30 minutes.

scholarly journals Interleukin-6 mRNA and protein increase in vivo following induction of acute thrombocytopenia in mice

Blood ◽  
1991 ◽  
Vol 77 (2) ◽  
pp. 286-293 ◽  
Author(s):  
LH Cox ◽  
T Downs ◽  
K Dagg ◽  
J Henthorn ◽  
SA Burstein
Keyword(s):  
Specific Activity ◽  
Rabbit Serum ◽  
Normal Rabbit Serum ◽  
Experimental Animals ◽  
Steady State Levels ◽  
Phosphate Buffered Saline ◽  
Protein Serum ◽  
Significant Increment

Abstract Induction of experimental thrombocytopenia in rodents results in the enhancement of megakaryocytic growth and differentiation. Interleukin-3 (IL-3) and IL-6, cytokines with a broad spectrum of biologic activities, stimulate megakaryocytopoiesis in vitro. To determine if expression of these factors might increase in response to experimental thrombocytopenia, we measured steady-state levels of IL-3 and IL-6 mRNA following rabbit antiplatelet serum (APS) injection. Groups of mice were injected intravenously with 0.2 mL APS while control animals received rabbit antilymphocyte serum (ALS), normal rabbit serum (NRS), or phosphate-buffered saline (PBS). At various times up to 72 hours after injection mice were exsanguinated and splenectomized. Platelet counts in the experimental animals were less than 12% of controls. Splenic RNA was hybridized in solution to 32P-UTP-labeled cRNA probes for IL-3 and IL-6. RNase-resistant hybrids were resolved on denaturing gels and visualized autoradiographically. IL-3 hybrids were undetectable at all time points tested, irrespective of the film exposure time or specific activity of the probe. Conversely, IL-6 hybrids were easily visualized and showed peak expression at 1.5 to 2.0 hours. By 3 hours, IL-6 mRNA had returned almost to the level of the controls. Similar results were observed in the bone marrow, although maximal IL-6 mRNA in that tissue was observed 4 hours following APS administration. To determine if this mRNA increment was associated with a concomitant increase in bioactive protein, serum was tested for its ability to stimulate IL-6-dependent B9 cells. At 1.75 hours following injection, experimental animals showed a small but significant increment in IL-6 activity compared with controls (200 +/- 30 U/mL IL-6 compared with 129 +/- 17 U/mL in ALS-injected controls, 106 +/- 17 U/mL in NRS-injected controls and 84 +/- 17 U/mL in PBS-injected controls). The data show that IL-6 mRNA and bioactive protein increase in response to acute immunothrombocytopenia, while no increment in IL-3 is detectable. These results suggest that IL-6 may play a role in the physiologic response to acute immunothrombocytopenia.

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