scholarly journals STUDIES ON HOST-VIRUS INTERACTIONS IN THE CHICK EMBRYO-INFLUENZA VIRUS SYSTEM

1951 ◽  
Vol 94 (4) ◽  
pp. 269-289 ◽  
Author(s):  
Oscar C. Liu ◽  
Werner Henle
Keyword(s):  
Influenza Virus ◽  
Growth Curve ◽  
High Speed ◽  
Allantoic Fluid ◽  
In Vitro Tests ◽  
Host Virus Interactions ◽  
Virus Interactions ◽  
Virus System

The role of inhibitors of hemagglutination in the evaluation of host-virus interactions in the chick embryo-influenza virus system has been analyzed. Comparisons were made between materials (allantoic fluids and membrane suspensions) derived from in vivo (growth curve) experiments at hourly intervals after inoculation, and from in vitro tests in which normal allantoic fluids and membrane suspensions were incubated with virus at 37°C. for various periods of time. In both instances large amounts of virus were added to the systems, resulting in comparable concentrations of the agent. The seeds employed were either fully active or irradiated by ultraviolet light to the extent that the virus lost its capacity to increase but kept its interfering and hemagglutinating properties. The various materials were assayed for (a) the hemagglutinating titers of the virus present in the systems before and after heating to 56°C.; (b) the concentration of inhibitor in the materials at various stages of incubation after heating to 70°C. for 30 minutes as measured by the hemagglutination-inhibition reaction with native or heated test virus (30 minutes 56°C.); and (c) the degree of adsorption of the hemagglutinins present in the materials onto chicken red cells at 0°C. and their subsequent elution at 37°C. The effects of receptor-destroying enzyme (RDE), treatment with sodium periodate, or high speed centrifugation on the inhibitory activities were studied in some of the tests. The essential results which indicate certain sources of error in the evaluation of host-virus interactions as well as means for studying virus activity at the early stages of the infectious process, were as follows: 1. Though some inhibitory effects on hemagglutination were noticeable in the allantoic fluid during the 1st hour after inoculation they were, as a rule, no longer apparent after this interval, and treatment with RDE did not increase the hemagglutinin titers. Thus, the interpretation of growth curve data concerning allantoic fluids hardly seems to be affected by inhibitor. On the other hand, striking effects were noted with the membrane suspensions of growth curve experiments in that RDE shortened the latent period to 2 hours and the titers in the first few positive samples (4 to 5 hours) increased) whereas in later harvests no such effect was noted. Under these conditions complement-fixation antigens and hemagglutinins made their appearance in the tissues simultaneously and not as previously reported the former prior to the latter. However, the infectivity showed increments only several hours after these two activities had become measurable. Thus the hypothesis of the stagewise development of influenza virus is still supported by these data. 2. Using the inhibition of hemagglutination technic it was found that the inhibitor in allantoic fluid rapidly decreased as a result of the action of active and irradiated virus, but destruction was never complete. In the membranes of the in vivo series only active seed led to loss of inhibitor, again without complete destruction, beginning at the time complement-fixing antigen and hemagglutinins became measurable. Irradiated seed was without effect in vivo whereas, in the in vitro tests it equalled the activity of the active virus. The implications of this difference in the effectiveness of active and irradiated seed in vivo with regard to the understanding of the mode of viral multiplication are discussed. 3. Although many factors may influence the shape of adsorption-elution curves it is felt that at 0°C. the extent of adsorption is directly related to the amount of inhibitor present in the systems. In the early hours after inoculation the degree of adsorption was relatively small but it increased gradually with the time of incubation. The inhibitor of adsorption was destroyed by RDE and NaIO4 and was only partially sedimentable by high speed centrifugation. In every respect studied its properties corresponded with the findings obtained with inhibitors in the hemagglutination-inhibition technic. Although the difference in the rapidity of inhibitor destruction as measured by the various technics might suggest a multiplicity of inhibitors it is felt that it rather denotes a greater sensitivity of the adsorption technic as compared to the others.

scholarly journals STUDIES ON HOST-VIRUS INTERACTIONS IN THE CHICK EMBRYO-INFLUENZA VIRUS SYSTEM

1955 ◽  
Vol 101 (5) ◽  
pp. 493-506 ◽  
Author(s):  
Kurt Paucker ◽  
Werner Henle
Keyword(s):  
Influenza Virus ◽  
Infectious Virus ◽  
Allantoic Fluid ◽  
Progressive Reduction ◽  
Virus Particles ◽  
Host Virus Interactions ◽  
Virus Interactions ◽  
Available Information ◽  
Virus System

An experimental analysis is here presented of the conditions that lead to the appearance of non-infectious hemagglutinins (NIHA) in the allantoic fluid of chick embryos injected with standard influenza virus (PR8 strain) which had been exposed to 37°C. in vitro for various periods of time. On progressive reduction of the infectivity of the undiluted inocula from about 109 to 103 ID50 (103.2 HA units) the yields of infectious virus in 24 hours decreased in straight correspondence 1 millionfold, but those of hemagglutinins only by a factor of 10. Thus the proportions of NIHA in the yields increased sharply but the total quantity obtained decreased gradually. The quantities of infectious virus produced per ID50 injected were the same throughout this range; i.e., between 50 and 100 ID50, regardless of increasing proportions of heat-inactivated virus in the seeds. This value agrees with previous estimates of yields under other conditions. Thus, initiation and completion of first cycles by the infectious virus remaining in the inocula were not, or at most, slightly inhibited. The inactivated virus, therefore, failed to establish immediate interference. It was capable, however, of holding the infectious process to one cycle. Upon 10-fold dilution of the seeds essentially similar results were obtained except that a slight loss in interfering activity could now be detected with an increase in exposure to 37°C. With further dilutions little or no interference was noted. The capacity to yield NIHA decreased slowly during exposure of the seeds to 37°C. over a period of 5 days, thereafter more rapidly. It could not be restored by addition of infectious virus. Furthermore, since NIHA was obtained when the seeds contained as little as 102 or 103 ID50, it is unlikely that it was derived from those cells which had adsorbed both infectious and inactivated seed virus. It is suggestive that multiple adsorption of inactivated virus particles per se will yield NIHA. The available information, as discussed, favors the view that the NIHA does not represent seed virus in some form but is newly produced.

scholarly journals STUDIES ON HOST-VIRUS INTERACTIONS IN THE CHICK EMBRYO-INFLUENZA VIRUS SYSTEM

1949 ◽  
Vol 90 (1) ◽  
pp. 23-37 ◽  
Author(s):  
Werner Henle ◽  
Gertrude Henle
Keyword(s):  
Influenza A ◽  
Allantoic Fluid ◽  
Experimental Period ◽  
Virus Antigen ◽  
Immune Serum ◽  
Host Virus Interactions ◽  
Virus Interactions ◽  
Infectivity Titer ◽  
Infectious Cycle ◽  
Virus System

In agreement with earlier observations the infectivity titer in the allantoic fluids of chick embryos injected with influenza A virus remains constant for 5 to 6 hours before an increase in this activity can be noted. In contrast, the titers of hemagglutinin and complement-fixing antigen (virus antigen) have already begun to rise after 3 hours. The origin of the hemagglutinating and complement-fixing but non-infectious material is still obscure. In the allantoic membrane development of both the soluble and virus antigens can be demonstrated after the 2nd hour of incubation and 1 hour prior to an increase in hemagglutinins and 2 hours prior to a rise in infectivity. Thus there remain the first 2 hours during which no record of virus activity in the tissues can be obtained. Similar relationships are noted on dilution of the seed both in the allantoic fluids and membranes as long as the various properties reach measurable levels during the experimental period of one infectious cycle. Injection of high titered immune serum following infection with about 109 ID50 reduces the amount of demonstrable seed virus in the allantoic fluid and membrane without significantly affecting propagation of the agent in the tissues as measured by infectivity titrations. The production of hemagglutinins appears markedly reduced under these conditions whereas formation of complement-fixing antigen is only slightly delayed and decreased. No definite explanations for the various discrepancies between the infectivity and hemagglutination can be given at present.

scholarly journals Modeling Host-Virus Interactions in Viral Infectious Diseases Using Stem-Cell-Derived Systems and CRISPR/Cas9 Technology

Viruses ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 124 ◽  
Author(s):  
Jihoon Kim ◽  
Bon-Kyoung Koo ◽  
Ki-Jun Yoon
Keyword(s):  
Stem Cell ◽  
Viral Infections ◽  
Adult Stem Cell ◽  
Viral Pathogenesis ◽  
Extensive Study ◽  
Model Systems ◽  
Host Virus Interactions ◽  
Virus Interactions

Pathologies induced by viral infections have undergone extensive study, with traditional model systems such as two-dimensional (2D) cell cultures and in vivo mouse models contributing greatly to our understanding of host-virus interactions. However, the technical limitations inherent in these systems have constrained efforts to more fully understand such interactions, leading to a search for alternative in vitro systems that accurately recreate in vivo physiology in order to advance the study of viral pathogenesis. Over the last decade, there have been significant technological advances that have allowed researchers to more accurately model the host environment when modeling viral pathogenesis in vitro, including induced pluripotent stem cells (iPSCs), adult stem-cell-derived organoid culture systems and CRISPR/Cas9-mediated genome editing. Such technological breakthroughs have ushered in a new era in the field of viral pathogenesis, where previously challenging questions have begun to be tackled. These include genome-wide analysis of host-virus crosstalk, identification of host factors critical for viral pathogenesis, and the study of viral pathogens that previously lacked a suitable platform, e.g., noroviruses, rotaviruses, enteroviruses, adenoviruses, and Zika virus. In this review, we will discuss recent advances in the study of viral pathogenesis and host-virus crosstalk arising from the use of iPSC, organoid, and CRISPR/Cas9 technologies.

scholarly journals STUDIES ON HOST-VIRUS INTERACTIONS IN THE CHICK EMBRYO-INFLUENZA VIRUS SYSTEM

1955 ◽  
Vol 101 (5) ◽  
pp. 479-492 ◽  
Author(s):  
Kurt Paucker ◽  
Werner Henle
Keyword(s):  
Influenza Virus ◽  
Infectious Virus ◽  
Growth Curves ◽  
Chick Embryos ◽  
Differential Growth ◽  
Host Virus Interactions ◽  
Virus Interactions ◽  
Allantoic Cavity

The role of inactivated influenza virus in the von Magnus phenomenon has been studied by exposing standard virus preparations in vitro to 37°C. for periods up to 6 or more days. The rate of inactivation of the infectious property of the line of PR8 virus employed was found to be approximately 1.1 log10 unit per day, denoting a half-life of 6½ hours. The rate of inactivation was similar in the allantoic cavity of chick embryos. On allantoic passage of such heated seeds without dilution it was seen that with a decrease in the infectivity of the inocula proportionately less infectious virus was found in the harvests. The yields of hemagglutinins were much less affected, and thus ID50/HA ratios of as low as 101.0 were observed in the 24 hour harvests. The ratios of the yields always equalled or were higher than those of the inocula. On 100- or 1000-fold dilution of the heated seeds standard virus was obtained. Growth curves in intact chick embryos or in deembryonated eggs (differential yields) revealed that non-infectious hemagglutinins appeared in the tissues or were liberated therefrom as soon as any virus activity became detectable. Furthermore, once maximal liberation had been established, infectious virus and non-infectious hemagglutinins were released for extended periods of time at nearly constant rates and in unchanging proportions, the latter depending upon the seed employed. Heated standard virus and undiluted passage seeds (von Magnus), selected on the basis of similar ID50 and HA concentrations, failed to yield similar results in differential growth curves in deembryonated eggs. Although the hemagglutinin titers in the 2-hourly harvests were nearly identical, the undiluted passage seeds produced as little as 1 per cent of the infectious virus which was derived from the heated inocula. Thus considerable differences exist between the 2 types of seeds.

scholarly journals STUDIES ON HOST-VIRUS INTERACTIONS IN THE CHICK EMBRYO-INFLUENZA VIRUS SYSTEM

1955 ◽  
Vol 101 (5) ◽  
pp. 461-478 ◽  
Author(s):  
Norman B. Finter ◽  
Oscar C. Liu ◽  
Werner Henle
Keyword(s):  
Influenza Virus ◽  
Chick Embryo ◽  
Host Cell ◽  
Infectious Virus ◽  
Chick Embryos ◽  
In Ovo ◽  
Virus Particles ◽  
Host Virus Interactions ◽  
Virus Interactions ◽  
Virus System

An analysis has been made of factors contributing to the von Magnus phenomenon; i.e., the emergence of increasing quantities of non-infectious hemagglutinins (NIHA) in successive passages in the allantois of chick embryos of undiluted allantoic fluids infected with influenza virus. Using the PR8 strain, the von Magnus phenomenon was pronounced when the serial seeds were obtained under conditions which permitted extensive inactivation of infectious virus during individual passages. Correspondingly, it was reduced but not abolished when precautions were taken to avoid accumulation of inactivated virus in the inocula. Thus, inactivated virus may be taken as a contributing factor. Preparations of infectious virus obtained under conditions largely excluding the presence of inactivated virus were capable of yielding some NIHA on passage as long as sufficient amounts were injected to permit each host cell to adsorb several infectious virus particles. However, the fact remains that more NIHA was found in the harvests when the inocula contained a large proportion of non-infectious virus material. Following injection of various types of seeds NIHA appeared in the allantoic fluids as soon as liberation of virus became detectable. This time relationship and the rates of release of non-infectious virus components seemed to exclude that the NIHA obtained consisted entirely of infectious virus which had been inactivated during incubation in ovo. It was apparent rather that NIHA other than that due to heat-inactivated virus was released. Correlations between the infectivities and hemagglutinating capacities of over 50 standard and undiluted passage seeds and the compositions of the harvests derived therefrom on passage without dilution indicated that the corresponding activities in the yields did not depend entirely upon the relative concentrations of infectious virus and non-infectious hemagglutinins in the inocula but that apparently different forms of NIHA were obtained in successive undiluted passages.

Comparison of High Purity Factor IX Concentrates and a Prothrombin Complex Concentrate in a Canine Model of Thrombogenicity

1991 ◽  
Vol 66 (05) ◽  
pp. 609-613 ◽  
Author(s):  
I R MacGregor ◽  
J M Ferguson ◽  
L F McLaughlin ◽  
T Burnouf ◽  
C V Prowse
Keyword(s):  
High Purity ◽  
Time Course ◽  
Prothrombin Complex Concentrate ◽  
Degradation Products ◽  
Canine Model ◽  
Factor Ix ◽  
In Vitro Tests ◽  
Albumin Infusion

SummaryA non-stasis canine model of thrombogenicity has been used to evaluate batches of high purity factor IX concentrates from 4 manufacturers and a conventional prothrombin complex concentrate (PCC). Platelets, activated partial thromboplastin time (APTT), fibrinogen, fibrin(ogen) degradation products and fibrinopeptide A (FPA) were monitored before and after infusion of concentrate. Changes in FPA were found to be the most sensitive and reproducible indicator of thrombogenicity after infusion of batches of the PCC at doses of between 60 and 180 IU/kg, with a dose related delayed increase in FPA occurring. Total FPA generated after 100-120 IU/kg of 3 batches of PCC over the 3 h time course was 9-12 times that generated after albumin infusion. In contrast the amounts of FPA generated after 200 IU/kg of the 4 high purity factor IX products were in all cases similar to albumin infusion. It was noted that some batches of high purity concentrates had short NAPTTs indicating that current in vitro tests for potential thrombogenicity may be misleading in predicting the effects of these concentrates in vivo.

A Comparison of the in Vitro and in Vivo Thrombogenic Activity of Factor IX Concentrates Using Stasis (Wessler) and Non-Stasis Rabbit Models

1980 ◽  
Vol 44 (02) ◽  
pp. 081-086 ◽  
Author(s):  
C V Prowse ◽  
A E Williams
Keyword(s):  
Platelet Rich Plasma ◽  
Thrombus Formation ◽  
Factor Ix ◽  
Coagulation System ◽  
In Vitro Tests ◽  
Clinical Use ◽  
Low Activity

SummaryThe thrombogenic effects of selected factor IX concentrates were evaluated in two rabbit models; the Wessler stasis model and a novel non-stasis model. Concentrates active in either the NAPTT or TGt50 in vitro tests of potential thrombogenicity, or both, caused thrombus formation in the Wessler technique and activation of the coagulation system in the non-stasis model. A concentrate with low activity in both in vitro tests did not have thrombogenic effects in vivo, at the chosen dose. Results in the non-stasis model suggested that the thrombogenic effects of factor IX concentrates may occur by at least two mechanisms. A concentrate prepared from platelet-rich plasma and a pyrogenic concentrate were also tested and found to have no thrombogenic effect in vivo.These studies justify the use of the NAPTT and TGt50 in vitro tests for the screening of factor IX concentrates prior to clinical use.

Inhibition of Fibrinolysis and Fibrinogenolysis in Man: Comparison of ε-Aminocaproic Acid and Kallikrein Inhibitor

1963 ◽  
Vol 10 (01) ◽  
pp. 106-119 ◽  
Author(s):  
E Beck ◽  
R Schmutzler ◽  
F Duckert ◽  
Keyword(s):  
Aminocaproic Acid ◽  
Side Reactions ◽  
In Vitro Tests ◽  
Factor V ◽  
Clinical Use ◽  
Strong Inhibitor ◽  
Kallikrein Inhibitor ◽  
Therapeutic Possibilities

SummaryInhibitor of kallikrein and trypsin (KI) extracted from bovine parotis was compared with ε-aminocaproic acid (EACA): both substances inhibit fibrinolysis induced with streptokinase. EACA is a strong inhibitor of fibrinolysis in concentrations higher than 0, 1 mg per ml plasma. The same amount and higher concentrations are not able to inhibit completely the proteolytic-side reactions of fibrinolysis (fibrinogenolysis, diminution of factor V, rise of fibrin-polymerization-inhibitors). KI inhibits well proteolysis of plasma components in concentrations higher than 2,5 units per ml plasma. Much higher amounts of KI are needed to inhibit fibrinolysis as demonstrated by our in vivo and in vitro tests.Combination of the two substances for clinical use is suggested. Therapeutic possibilities are discussed.

Role of in vivo and in vitro Tests in the Diagnosis of Severe Cutaneous Adverse Reactions (SCAR) to Drug

2019 ◽  
Vol 25 (36) ◽  
pp. 3872-3880 ◽  
Author(s):  
Marcel M. Bergmann ◽  
Jean-Christoph Caubet
Keyword(s):  
Adverse Reactions ◽  
Lymphocyte Transformation ◽  
Stevens Johnson Syndrome ◽  
In Vitro Tests ◽  
High Morbidity ◽  
Patch Tests ◽  
Severe Cutaneous Adverse Reactions ◽  
Cutaneous Adverse Reactions

Severe cutaneous adverse reactions (SCAR) are life-threatening conditions including acute generalized exanthematous pustulosis (AGEP), Stevens-Johnson Syndrome (SJS), toxic epidermal necrolysis (TEN) and drug reaction with eosinophilia and systemic symptoms (DRESS). Diagnosis of causative underlying drug hypersensitivity (DH) is mandatory due to the high morbidity and mortality upon re-exposure with the incriminated drug. If an underlying DH is suspected, in vivo test, including patch tests (PTs), delayed-reading intradermal tests (IDTs) and in vitro tests can be performed in selected patients for which the suspected culprit drug is mandatory, or in order to find a safe alternative treatment. Positivity of in vivo and in vitro tests in SCAR to drug varies depending on the type of reaction and the incriminated drugs. Due to the severe nature of these reactions, drug provocation test (DPT) is highly contraindicated in patients who experienced SCAR. Thus, sensitivity is based on positive test results in patients with a suggestive clinical history. Patch tests still remain the first-line diagnostic tests in the majority of patients with SCAR, followed, in case of negative results, by delayed-reading IDTs, with the exception of patients with bullous diseases where IDTs are still contra-indicated. In vitro tests have shown promising results in the diagnosis of SCAR to drug. Positivity is particularly high when the lymphocyte transformation test (LTT) is combined with cytokines and cytotoxic markers measurement (cyto-LTT), but this still has to be confirmed with larger studies. Due to the rarity of SCAR, large multi-center collaborative studies are needed to better study the sensitivity and specificity of in vivo and in vitro tests.

Hemostatic wound dressings: Predicting their effects by in vitro tests

2019 ◽  
Vol 33 (9) ◽  
pp. 1285-1297 ◽  
Author(s):  
Cornelia Wiegand ◽  
Martin Abel ◽  
Uta-Christina Hipler ◽  
Peter Elsner ◽  
Michael Zieger ◽  
...  
Keyword(s):  
Blood Clot ◽  
Wound Dressings ◽  
In Vitro Tests ◽  
Regenerated Cellulose ◽  
Oxidized Regenerated Cellulose ◽  
Inflammatory Reactions ◽  
In Vitro Techniques ◽  
Cotton Gauze

Background Application of controlled in vitro techniques can be used as a screening tool for the development of new hemostatic agents allowing quantitative assessment of overall hemostatic potential. Materials and methods Several tests were selected to evaluate the efficacy of cotton gauze, collagen, and oxidized regenerated cellulose for enhancing blood clotting, coagulation, and platelet activation. Results Visual inspection of dressings after blood contact proved the formation of blood clots. Scanning electron microscopy demonstrated the adsorption of blood cells and plasma proteins. Significantly enhanced blood clot formation was observed for collagen together with β-thromboglobulin increase and platelet count reduction. Oxidized regenerated cellulose demonstrated slower clotting rates not yielding any thrombin generation; yet, led to significantly increased thrombin-anti-thrombin-III complex levels compared to the other dressings. As hemostyptica ought to function without triggering any adverse events, induction of hemolysis, instigation of inflammatory reactions, and initiation of the innate complement system were also tested. Here, cotton gauze provoked high PMN elastase and elevated SC5b-9 concentrations. Conclusions A range of tests for desired and undesired effects of materials need to be combined to gain some degree of predictability of the in vivo situation. Collagen-based dressings demonstrated the highest hemostyptic properties with lowest adverse reactions whereas gauze did not induce high coagulation activation but rather activated leukocytes and complement.

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