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Biomedical subjects

R Wigand

Publications and source records attributed to R Wigand.

At least 91 records · Page 5Linked to original sources
PubMed1982

Enzyme-linked immunosorbent assay for acute adenovirus infection.

An enzyme-linked immunosorbent assay (ELISA) is described for demonstrating antibodies to the hexone antigen of adenoviruses. The antigen-coated, flat-bottomed microtiter plates are incubated sequentially with dilutions of patients' sera (2 h at 37 degrees C) and peroxidase-coupled anti-human IgG (2 h at 37 degrees C). After a final washing, orthophenylenediamine is added to the plates, and the absorbance (A) measured 30 min later. The ELISA was found to be a hundred-fold more sensitive than complement fixation. An evaluation methods for determining antibody concentration is described which correlates the absorbance of sera diluted 10(-3) to the absorbance of a reference serum containing an arbitrary value (100) of antibody. This methods avoids titration of sera and day-to-day assay variations by different background reactions. A significant increase in antibody concentration of acute-phase serum over that of convalescent phase serum is observed. The ability to test sera in a single dilution and the automatic reading of results and their evaluation by computer make this assay suitable for diagnostic laboratories.

Adenoviridae Infections↗
PubMed1982

[Virological diagnosis of ocular adenovirus infection].

For laboratory diagnosis, virus isolation and identification from conjunctival swabs should be combined with serology (two blood specimens: early and 14 days or later after onset of disease). The group-specific complement fixation fails in almost one-half of the cases. Additional type-specific reactions (neutralization, hemagglutination inhibition, type-specific complement fixation) may be performed with adenovirus 8 and, in epidemic outbreaks, also with other types. Immunofluorescence procedures have proved to be of limited value; rapid diagnostic procedures are not yet available.

Adenoviridae Infections↗
PubMed1982

[Laboratory procedures in adenoviruses. VIII. Immunoglobulin class-specific ELISA for the demonstration of antibodies against adenovirus hexon].

Serum pairs from 114 patients with adenovirus infections (mostly ocular disease in adults) were investigated by an ELISA, with purified adenovirus 5 hexon coated to the solid phase, diluted sera, and peroxydase-labeled antihuman IgG, IgA, and IgM antibodies. Serum dilutions of 1:3200, 1:200, and 1:100 respectively proved to be optimal to demonstrate antibody rises. Sera from infants served as negative controls. Antibody rises were found in the IgG and/or IgA test 85% of the patients, but only in 56% by complement fixation. Antibody rises in all three ELISA tests occurred mostly around the 10th day after onset of disease. Fewer antibody rises and weak reactions were found in IgM test. Moreover, IgM antibodies were present also in persons without fresh adenovirus infection. Hence, this test is not suitable for an early diagnosis. This observation is probably due to the frequent stimulation of the immune system by the genusspecific determinant alpha of the hexon by repeated adenovirus infections during life.

Adenoviridae Infections↗
PubMed1981

Adenovirus 37: identification and characterization of a medically important new adenovirus type of subgroup D.

A new human adenovirus has been isolated from 62 eyes with (kerato)conjunctivitis and from nine genitourinary sites. The virus is closely related in haemagglutination inhibition tests to adenovirus type 19 (Ad 19) and Ad 10. Antiserum adsorption experiments demonstrated the presence of three haemagglutinin antigens in the virus: One unique, another common to Ad 19, and a third common to Ad 10 and 19. In neutralization tests, the virus is distantly related to Ad 13, 30, 19, and 10. Despite this relationship, it is proposed to call the virus adenovirus 37, in agreement with current species definitions. It belongs to subgroup D of human adenoviruses. Antisera to the new virus show virtually no neutralization of other human adenovirus types. Only bay use of this antiserum it is in practice possible to avoid wrong or indefinite typing, which has often occurred in the past.

Adenoviruses, Human↗
PubMed1981

[The effect of viruses on megakaryocytes in vitro (author's transl)].

Bone marrow suspensions from adolescent rats contain 0.3% megakaryocytes; this rate decreases to almost zero within 72--96 h cultivation in vitro in Leighton tubes because of thrombocytopoesis. Such cultures were inoculated immediately after seeding with different viruses in high multiplicity. After infection with herpes simplex virus type 1 or adenovirus type 2, no deviation of the number and morphology of the megakaryocytes was seen when compared with control cultures. However, after infection with vaccinia virus and, still more marked, with Newcastle disease virus, morphological alterations and interference with thrombocytopoesis were seen. Furthermore, a considerable portion of the altered megakaryocytes persisted for 72--96 h. Finally, the cytoplasm of the megakaryocytes after infection with vaccinia virus or NDV, but not with HSV 1 or adenovirus 2, showed a specific immunofluorescence with antiviral antisera, which indicates a direct cellular involvement and multiplication of vaccinia virus and NDV in megakaryocytes.

Adenoviruses, Human↗
PubMed1981

Stabilization of isometric DNA viruses against thermoinactivation by lowered ionic strength.

The thermostability of isometric DNA viruses increases, if the ionic strength is diminished before heating. When unpurified virus material from cell cultures is heated under conditions (temperature, time) which lead to a reduction in infectivity by 3 to 4 log10, this loss in titer is 1 to 3 log10 less, if the ionic strength is decreased by diluting the material in dist. water (1:100) before heating. A dilution in Eagle's MEM (1:100) or a previous dialysis against water does not have the same effect. This property was found in the following members of 4 DNA virus families: adenovirus 5, herpesvirus 1, SV 40 and bovine parvovirus 1. In contrast, members of pox- (vaccinia) and picornaviruses (polio 2, coxsackie B5) were found to be less thermostable under conditions of low ionic strength. Reovirus 3 showed no difference in inactivation. The observed effect may be of practical importance for heat disinfection of viruses and for their persistence in the environment.

Adenoviruses, Human↗
PubMed1981

Stabilization of adenovirus infectivity against thermoinactivation by lowered ionic strength.

The thermostability of adenovirus 5 increases when the ionic strength is decreased before heating by dilution in distilled water (1 : 100, heating at 50 degrees C). A predilution in Eagle's MEM before heating or a previous dialysis against water had no effect on thermostability. The stabilizing effect was found likewise in crude and purified virus, in heating at 50 degrees C up to 320 min, from 50 degrees C to 56 degrees C, and in dilution from 10(-2) to 10(-5). The degree of stabilization was similar to cationic stabilization in 2M NaCl. The infectivity of heated adenovirus 5 was not sensitivity to DNase digestion. Other adenovirus types were stabilized in a similar manner.

Adenoviruses, Human↗
PubMed1981

Neutralization of adenovirus infectivity and cytotoxin in various cell cultures.

The neutralization of human adenovirus 5 and 11 by homologous and heterologous rabbit antisera was determined by CPE inhibition in various cell cultures (HeLa, HEL, Vero, secondary kidney cells from cercopithecus, rabbit, mouse), or in HeLa cells made impermissive by IUdR inhibition. The results concerning sensitivity and specificity were similar in all cases. Crude and purified virus showed similar neutralization. Immunofluorescence neutralization in HeLa cell cultures gave similar results; this method is suitable for demonstrating subtle immunological relations between adenovirus types. The neutralization of the early cytopathic factor ('cytotoxin') showed a pattern of cross-reactivity different from the virion; the cytotoxin was found to be active in part of the cell cultures only. It is concluded from the results that the virus function(s) blocked by antibody appear to be identical for the replicative cycle in infection and for the initiation of the abortive infection in non-permissive cells. Hence, either kind of cells may be used for neutralization tests.

Adenoviruses, Human↗
PubMed1981

Immunological relationship among adenoviruses of humans, simians, and nonprimates as determined by the neutralization test.

98 antisera prepared against 25 simian adenoviruses and 31 adenovirus types from various nonprimate mammals and birds were tested for their ability to neutralize 35 human adenovirus prototypes. Antisera to these human adenovirus types were similarly tested against 25 simian adenovirus prototypes. Although very few reactions to the human adenoviruses were found in antisera to nonprimate viruses, cross-reactions among the simian and human adenoviruses were more frequent. The majority of these reactions, however, were of low titer and of questionable significance. Two chimpanzee adenovirus strains--Pan 9 and SAV 21 (C 1)--were found with an immunological relationship to human adenoviruses: Pan 9 strain showed a two-way cross relationship to human adenovirus 4, and SAV 21 (C 1) was neutralized by antisera prepared against human adenoviruses 14 and 16.

Adenoviridae↗
PubMed1981

Combined inhibition of vaccinia virus multiplication by inhibitors of DNA synthesis.

Nine purine or pyrimidine analogues or other inhibitors of DNA synthesis were studied for their inhibition of vaccinia virus multiplication by a plaque inhibition test with a fluid overlay in Vero cell cultures, either as single substances or in combination. Experiments on combined inhibition were made with substance concentrations leading to 80-90% plaque inhibition; indifference, additive, or synergistic interaction were evaluated from normalized plaque counts. 12 substance pairs acted in a synergistic manner and 22 showed indifference. A comparison was made with the results of other DNA viruses (adenovirus, herpes simplex virus).

DNA↗
PubMed1981

[Laboratory procedures in adenoviruses. vii. susceptibility of human diploid fibroblasts (author's transl)].

Six prototype strains of human adenoviruses (Ad 1, 4, 7, 8, 12, 19) were passed and titrated comparatively in four strains of human diploid fibroblast cultures. The viruses were readily passed 5 times with cytopathic effect; no signs of adaptation or dimunition of CPE were apparent. The virus yield was about equal in fibroblasts and in HeLa cells. High and low passage fibroblasts were of equal susceptibility. In endpoint titrations, fibroblast cultures showed an about 10-fold lower susceptibility towards Ad1 and Ad7; however, they compared favorably for Ad4, 8, 12, and 19 with HeLa or (for Ad8) with human amnion cell cultures. In some instances differences in the susceptibility between fibroblast strains were observed. Fibroblast cultures and human amnion cells showed equal susceptibility for Ad8 from 9 original conjunctival specimens, while results with other types varied. For adenovirus isolation, fibroblast cultures are suitable as an adjunct to HeLa cell cultures, particularly for Ad8. However, the long duration till the appearance of CPE which sometimes exceeds 50 days is a disadvantage.

Adenoviruses, Human↗
PubMed1980

Age and susceptibility of Swiss mice for mouse adenovirus, strain FL.

NMRI mice of different ages (24 hours, 10 to 12 days old, adults) were inoculated intraperitoneally with varying doses of mouse adenovirus. The susceptibility to disease was high in newborn mice (1 LD50 equalled 7 TCID50, as measured in mouse kidney cell cultures), medium in 10 days' old mice and almost nil in adult animals. The survival time was not greatly influenced by the virus dose. The susceptibility to infection is greatest in adults and lowest in 10 day old mice; these show a susceptibility equal to kidney cell cultures. In newborn mice, the virus spreads via the blood to all organs tested except for the intestinal tract, peak titers being reached in kidney and liver for at least 52 days, together with a sustained viruria. Adult mice could be infected by oral or intranasal installation.

Adenoviridae↗
PubMed1980

New human adenovirus (candidate adenovirus 36), a novel member of subgroup D.

A new adenovirus (candidate Ad36) was isolated from the feces of a girl with enteritis. It has been biological and biophysical properties of an adenovirus, with a particle diameter of 750 +/- 10 A in thin sections and with a fiber length of 190 A. The virus belongs to subgroup D. It is distinct both in neutralization and hemagglutination-inhibition from all other human adenoviruses; it also shows a unique DNA restriction pattern.

Adenoviruses, Human↗
PubMed1980

Combined antiviral effect of DNA inhibitors on Herpes simplex virus multiplication.

The inhibition of herpesvirus type 1 in cell cultures by seven inhibitors of DNA synthesis and by pactamycin was investigated by plaque inhibition in Vero cells with agarose overlay, and by yield reduction in one-step growth in HeLa cells. While the plaque inhibition method proved to be suitable to show inhibition by single substances, only the yield reduction procedure was reliable for investigating the interaction of two substances. Inhibition was evaluated by means of an inhibition quotient (number of PFU in uninhibited virus controls:number of PFU in test specimen); combined inhibition was related to results with single substances. Among the 28 substance pairs, 9 cases of indifference, 10 additive, and 9 synergistic interactions were found. Indifference was observed only with fluorodeoxyuridine and amethopterin as one of the partners, which by themselves inhibited herpesvirus multiplication incompletely.

Animals↗
PubMed1980

[The effects of topical steroids in epidemic kerato-conjunctivitis (author's transl)].

Fifty-three patients with proven adenovirus type 8 infection were treated at random, in a prospective study, with either artificial tears or topical steroids over six weeks. Severe cases of nummular keratitis, as well as deep keratitis and slight iritis, were significantly less frequent under steroids. No difference existed with respect to the course of the conjunctivitis and the frequency of a superficial punctate keratitis. Furthermore, the overall frequency of nummular keratitis was equal in both groups, its manifestation merely being somewhat delayed in the steroid group. This may even be disadvantageous, as the natural course of the disease could be prolonged. A significant disadvantage of topical steroids, however, was the high incidence of permanent "dry eye" in the post-infection period. Therefore, as long as no effective antiviral treatment for adenovirus infection is available, steroids should only be administered to relieve symptoms in severe cases for a limited time.

Adenoviridae Infections↗
PubMed1980

Derivatives of 3'- and 5'-deoxyadenosine: their inhibitory activity against DNA viruses.

3'-Deoxyadenosine, 3'-amino-3'-deoxyadenosine (3'3'), nine derivatives therefrom, two derivatives of 5'-amino-5'-deoxyadenosine and three derivates of 3', 5'-dideoxyadenosine were tested in cell culture for antiviral activity against three DNA viruses: adenovirus 5, herpesvirus hominis 1, and vaccinia virus. Cytotoxicity was also assessed. (3'3') derivatives affected the multiplication of all three viruses similarly. Those which were effective were also cytotoxic at the same or slightly higher concentration. Substitution or other molecular modification of (3'3') tend to lower the biological activity. The presence of an adenosine deaminase inhibitor enhanced both antiviral activity against adenovirus 5 and cytotoxicity in (3'3') compounds, but not in the others. Both 5'-amino-5'-deoxyadenosine compounds were active against vaccinia virus only. Of the three 3', 5'-dideoxyadenosines, only one had both cytotoxic and antiviral activity. Most, if not all, seemingly antiviral effects appear to be caused by inhibition of the cell metabolism.

Adenosine Deaminase Inhibitors↗
PubMed1980

[Intensified adsorption of viruses to cell cultures: improved virus isolation? (author's transl)].

Two procedures to improve virus cultivation from clinical material were evaluated: an intensified adsorption with 0.2 ml inoculum and 20 h rocking in a Bellco rocker and a low-speed centrifugation of the material onto the cultured cells. Prototype strains from 5 virus families (adenoviruses, herpes simplex virus, vaccinia virus, enteroviruses, parainfluenza 2) as well as original specimens from patients (adenovirus, herpesvirus, enterovirus) were studied by endpoint titration in comparison with the standard procedure. In adenoviruses, a quantitative immunofluorescence was performed too. In endpoint titrations, the centrifugation method did almost never lead to an increased virus titer, as compared with the standard method. However, in the immunofluoresence evaluation of adenoviruses the values attained were 3- to 4-fold higher. On the other hand, the intensified adsorption method led to an increased sensitivity in most adenovirus titrations with 4- to 25-fold titer increment, with prototype and original material. The procedure was ineffective in all other viruses studied.

Adsorption↗