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Biomedical subjects

A German

Publications and source records attributed to A German.

At least 19 recordsLinked to original sources
PubMed1999

Isotype- and subclass-specific responses to infection and reinfection with parainfluenza-3 virus: comparison of the diagnostic potential of ELISAs detecting seroconversion and specific IgM and IgA.

Isotype- and subclass-specific indirect enzyme-linked immunosorbent assays were developed to detect parainfluenza-3 virus-specific IgG1, IgG2, IgM, and IgA responses. Sera were treated with protein G-agarose prior to testing for specific IgM and IgA to eliminate the possibility of false-positive results due to IgM-rheumatoid factor and to remove interisotypic competition due to specific IgG. IgM and IgA absorbance values were expressed as a percentage of the absorbance values of positive reference sera included on each plate (S/P%), and respective positive/negative threshold values of 15.0% and 28.0% were determined. The mean interval between experimental infection of 3 calves and initial detection of specific IgG1 and IgG2 responses was 8.0 and 9.3 days respectively, rising rapidly to an initial plateau 13.7 and 11.0 days postinfection (dpi). Reinfection of these calves at 30 dpi resulted in further rapid increases, with higher plateau values reached 13.0 (IgG1) and 13.7 (IgG2) days later. The mean interval between infection and the first positive IgM and IgA responses was 6.7 and 12.3 days, respectively. IgM S/P% values peaked at 13.0 dpi, with all 3 calves showing a secondary anamnestic response to reinfection, peaking 4.7 days later. The IgA response to initial infection was weak, with only 2 calves showing an obvious peak response at 15.0 dpi. A strong anamnestic IgA response to reinfection occurred in 2 calves, with a peak response 9.5 days later. Apparent biphasic and triphasic IgM and IgA responses were evident in some calves. Acute and convalescent serum samples from 80 calves involved in 17 outbreaks of respiratory disease were tested for specific IgM and IgA. Positive IgM results were detected in 15 outbreaks, with 71 sera from 44 calves testing positive. Although IgA-positive results were detected in the same 15 outbreaks, only 42 sera from 31 calves were positive. In a previous study, seroconversion was detected in 21 of these calves from 10 outbreaks. Thus the diagnostic potential of the assays was in the order IgM > IgA > seroconversion. The correlations between IgM and IgA, IgM and seroconversion, and IgA and seroconversion results for each calf were 73.8%, 58.8% and 62.5%, respectively.

Animals↗
PubMed1999

Evaluation of an immunofluorescent antibody test to detect bovine herpesvirus 1-specific IgM.

An indirect immunofluorescent antibody test (IIFAT) was developed to detect bovine herpesvirus 1 (BHV-1)-specific IgM. All sera were treated with protein-G agarose prior to testing to eliminate the possibility of false-positive results due to IgM-isotype rheumatoid factor (IgM-RF). Specific IgM was first detected 8 days after experimental infection of 3 calves free of maternally derived antibody, with peak responses occurring 2-7 days later. Seroconversion was detected in all 3 calves using a single-dilution enzyme-linked immunosorbent assay. Following reinfection at 30 days postinfection, a low-level IgM response was detected in only 1 calf. Seroconversion was detected in 2 calves. There was no evidence of activation of IgM-RF by infection or reinfection with BHV-1. When 87 acute and convalescent serum pairs collected from 21 outbreaks of respiratory disease were tested, specific IgM was detected in 58 animals (66.6%) from 19 (90.5%) outbreaks. Seroconversion was detected in 44 of these animals (50.6%) from 17 outbreaks (81.0%). The correlations between these 2 assays on a calf and outbreak basis were 79.3% and 90.5%, respectively. Specific IgM was detected in 17/20 sera (85.0%) collected from an additional outbreak. No virus was detected by virus isolation or immunofluorescent staining in nasal mucus samples collected at the same time. Detection of specific IgM by IIFAT is a useful technique for the serodiagnosis of BHV-1 infection.

Acute Disease↗
PubMed1998

Evaluation of the suitability of a commercial bovine viral diarrhoea virus antigen capture ELISA for diagnostic testing.

The suitability of a commercial bovine viral diarrhoea virus (BVDV) antigen capture enzyme-linked immunosorbent assay (ELISA) for routine diagnostic testing of bovine serum samples was evaluated by comparing the ELISA results of 214 sera with those obtained after two passages in roller tube cultures of fetal bovine lung cells and immunofluorescent staining using fluorescein isothiocyanate-conjugated hyperimmune BVDV anti-serum. In addition, 208 of these samples were tested by virus isolation in a microtitre system followed by indirect immunoperoxidase staining using a pool of two non-competing pestivirus specific monoclonal antibodies. The sensitivity of the ELISA compared with virus isolation followed by immunofluorescent and immunoperoxidase staining was 47.8 and 45.8%, respectively. The corresponding figures of specificity and overall correlation were 95.3 and 95.1%, and 90.2 and 89.4%. Twenty-two of 24 pestivirus isolates from the positive blood samples were typed as BVDV-like by monoclonal antibodies, indicating that the poor sensitivity of the ELISA was not due to the presence of atypical pestiviruses in the test sample. These results suggest that this ELISA is not suitable for testing blood samples for BVDV in a diagnostic laboratory.

Animals↗
PubMed1995

Airbag deployments: the Canadian experience.

Transport Canada is undertaking an in-depth study of motor vehicle collisions involving airbag deployments. University-based collision investigation teams across Canada are used to collect crash data. The primary objective of the study is to gain a better understanding of the injuries and the injury mechanisms associated with airbag deployments among both restrained and unrestrained occupants. Preliminary results show an exceptionally high level of seatbelt use in conjunction with the supplemental air cushion restraints. Most crashes are, however, of only minor to moderate severity, in which the seatbelt systems alone would be expected to provide adequate occupant protection. Initial findings indicate that, at the lower end of the collision severity spectrum, deployment of an airbag may, in some circumstances, increase the overall likelihood of injury to a restrained occupant. This suggests that the current deployment threshold is set too low, at least for belted occupants.

Accidents, Traffic↗
PubMed1994

Fatal injuries to restrained passenger car occupants in Canada: crash modes and kinematics of injury.

Passenger car collisions with other vehicles and with fixed objects were studied from a representative sample of fatal and injury-producing collisions collected according to a prescribed sampling plan. This paper describes our analysis of accidents involving restrained passenger car occupants who are fatally injured in collisions. Lateral collisions were found to be predominant, and both lateral and frontal collisions were associated with marked intrusion into the occupant compartment, causing direct, severe injuries to the head and chest of these occupants. Multiple severe injuries to more than one body region were common, and 90% of these victims died within one hour of the collision. The seat belt generally offered no protection to these fatally injured occupants. Reducing the incidence of fatal injury to properly restrained passenger car occupants will necessitate diminishing these very severe intrusion forces, especially from heavy trucks and fixed vertical hazards. For vehicle design modifications to be effective, it appears likely that roadway and roadside design and management must be included in the safety equation. Excessive speeds, inadequate traffic control, and unforgiving roadside hazards are playing a major role in the incidence of fatal injuries documented in this study.

Abbreviated Injury Scale↗
PubMed1990

[Prevention and therapeutical trials of a few current viral diseases].

Vaccines afford now good prevention of many viral diseases including Hepatitis B. In revenge, attempts of immunization against Herpes Virus types I and II did not result in large scale application of vaccination. Research for a vaccine against HIV encounters many difficulties due to virus variability and host reactions. The introduction of nucleosides analogues represented a great advance for antiviral chemotherapy. Weakly toxic drugs although efficacious against Herpes Virus replication are now available but they do not seem to prevent viral recurrences. As for HIV, its sensitivity to drugs like AZT has raised great hopes which were limited by their intrinsic toxicity. However, research and trials for more efficacious but less toxic drugs are further being developed.

HIV Infections↗
PubMed1990

[In vitro evaluation of antimicrobial activity of fusafungine].

Fusafungine is an antibiotic extracted from the fungus Fusarium laterium WR strain 437. The antimicrobial activity of fusafungine was determined on strains from laboratory collections and clinical isolates; since fusafungine is not soluble in the classical media, the usual techniques had to be modified. MICs for all the Gram-positive cocci and bacteria tested, aerobic, or anaerobic, were below 30 mcg/ml. The antimicrobial activity included Mycoplasma pneumoniae (MIC less than 18 mcg/ml) and Streptococcus mutans (MIC less than 30 mcg/ml). An antifungal activity was shown for most of the Candida albicans tested (MIC less than 32 mcg/ml) and for different Nocardia sp. (MIC less than 13 mcg/ml). Moreover, fusafungine induced neither acquired resistance nor cross-resistance towards the antibiotics classically used in therapy.

Aerosols↗
PubMed1990

Examination and analysis of seat belt loading marks.

In moderate to severe collisions, large decelerations and hence large forces are generated. Various components of the seat belt system are loaded, and physical evidence of this loading may be observed long after the collision event. Such witness marks result from interaction between different components of the restraint system, or between the restraint and portions of the vehicle interior. Detailed examination and analysis of such marks can establish whether or not the seat belt was in use, and also the precise manner in which the seat belt was worn. Such investigative techniques are critical for evaluating the collision performance of occupant restraint systems, and for positively identifying cases of restraint system misuse. This paper reviews the types of physical evidence which may be observed to determine restraint usage.

Accidents, Traffic↗
PubMed1988

Potentiating the effectiveness of influenza vaccination by a combined immunostimulation with P40 immunomodulator: an experimental study in mice.

Influenza vaccination is highly desirable in view of the epidemic character of this infection and of the severity that it can assume in high-risk and in elderly persons. Its effectiveness varies from 40-90%. Moreover, strains can undergo an antigenic drift in the course of an epidemic. Consequently, reinforcement of the immunogenicity of vaccines is required for achieving a more complete immunization coverage. Combination of an immunomodulator, the C. granulosum-derived P40 fraction, with influenza vaccine resulted in significant potentiation of vaccine immunogenicity. In addition to its adjuvant action, the P40 is also likely to exercise a protective effect by stimulating the non-specific immune defenses of the organism.

Adjuvants, Immunologic↗
PubMed1987

Relation between protective potency and specificity of antibodies in sera of tetanus immunized individuals.

Out of 157 human sera analyzed for antitetanus antibody content by ELISA, 13 turned out to contain only anti-BIIb antibodies, of which 8 proved to be neutralizing. Of these, the 3 sera 303, 306 and 312 together with a commercially available standard preparation of human antitetanus immunoglobulins were further analyzed as to their antibody composition by ELISA using plates sensitized with either the toxoid or various tetanus toxin-derived fragments. It was verified that the protective potency of these antisera was related mainly to their anti-BIIb antibody content. Adsorption experiments confirmed that anti-BIIb antibodies were primarily involved in toxin neutralization, although the presence of high levels of both anti-alpha and anti-Ibc antibodies could confer neutralizing capacity on the sera. A rabbit antiserum raised with the BIIb fragment resulted in a neutralizing antiserum that allowed us to calibrate the ELISA with the anti-BIIb antibodies as International Units.

Adolescent↗
PubMed1987

Immunity to tetanus: tetanus antitoxin and anti-BIIb in human sera.

Immunity to tetanus was investigated in 157 individuals aged between 1 and 77 years using, for the evaluation of both tetanus antitoxin and antibody to fragment BIIb (anti-BIIb), an easily performed ELISA that gave reproducible results. Among these people 72% were protected against tetanus (tetanus antitoxin titres greater than 0.06 IU ml-1). Anti-BIIb titres greater than 0.15 U ml-1 were found in 75% of the males vs 57% of the females (P less than 0.02) with marked variations according to age. Furthermore, 13 out of 41 individuals with antitoxin titres less than 0.06 IU ml-1 (not protected against tetanus) were found to have anti-BIIb titres greater than 0.15 U ml-1. These data raise questions as to the significance and protective effect of anti-BIIb against tetanus.

Adolescent↗
PubMed1987

Role of interferon, antibodies and macrophages in the protective effect of Corynebacterium parvum on encephalomyocarditis virus-induced disease in mice.

Treatment of mice with Corynebacterium parvum enhances their resistance to encephalomyocarditis (EMC) virus infection. In EMC-virus-infected mice, pretreated with C. parvum, neither interferon production nor antibody responses were increased. A decrease of virus recovery was observed in cultures of macrophages taken from the peritoneum of mice early after injection of C. parvum and infected with EMC-virus in vitro. The data suggest that C. parvum acts by increasing intrinsic antiviral activity of macrophages.

Animals↗
PubMed1987

Inhibition of [14C]aminopyrine uptake in rat isolated gastric mucosal cells by two classes of psychotropic agents.

Certain CNS-active compounds decrease gastric acid secretion in vivo. In this study a number of tricyclic antipsychotic or antidepressant compounds together with haloperidol, a nontricyclic antipsychotic agent, were shown to inhibit dibutyryl-cAMP-stimulated [14C]aminopyrine uptake, an index of acid secretory activity in a rat isolated gastric mucosal cell preparation. The observed order of potency was: thioridazine greater than chlorpromazine greater than haloperidol approximately equal to desipramine approximately equal to imipramine greater than clozapine. Comparison of these potencies with those of the known (H+ + K+)ATPase inhibitors timoprazole and omeprazole revealed that the potency of timoprazole was similar to the one of clozapine while omeprazole was intermediate between thioridazine and chlorpromazine. Pirenzepine was ineffective.

2-Pyridinylmethylsulfinylbenzimidazoles↗