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.

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.

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.

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.

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.

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.

[Digestive and cutaneous colonization of Staphylococcus aureus, Pseudomonas aeruginosa and Corynebacterium xerosis in germ-free hairless mice]

Regardless of the method of germ-free HRS mouse contamination, the kinetics of Staphylococcus aureus and Pseudomonas aeruginosa cutaneous colonization was parallel to the kinetics of intestinal colonization; Corynebacterium xerosis, however, was unable to colonize the skin or the gastrointestinal tract. There was little variability in intestinal and cutaneous colonization; this was quite different from observations in man and hairless holoxenic mice. It is possible to use these experimental models to standardize the measurement of antiseptic bactericidal activity in vivo.

[Digestive and cutaneous colonization of Staphylococcus epidermidis in hairless axenic mice]

In order to determine the cutaneous and digestive colonization of S. epidermidis in germ-free HRS mice, several groups of animals were contaminated with this strain according to different methods. The bacterial cutaneous enumerations were performed after preliminary crushing of the cutaneous biopsy. In this study, whatever the method of contamination of germ-free HRS mice, the kinetics of S. epidermidis cutaneous colonization was parallel to the kinetics of intestinal colonization. The isolation of bacteria on skin was possible only when microorganisms were eliminated in faeces (6 h after contamination). During a single experiment, there was only slight variability in colonization, whether intestinal or cutaneous. Some differences could be found from one experiment to another, but all animals in the same trial showed the same cutaneous bacterial count. This experimental model is characterized by an interrelation between the intestinal and cutaneous ecosystems.

Influence of inhaled cadmium microparticles on mouse influenza pneumonia

A study of the effect of inhaled cadmium microparticles (CdO) on the mouse death rate from influenza pneumonia was performed on 936 female specific pathogen-free (SPF) Swiss mice. The test animals received a single short (15 min) exposure to 9 mg Cd/m3 of air (acute exposure), or renewed short exposures to 1 mg/m3 once a day, 5 days a week, for 4 weeks (chronic exposure). The cadmium found in the trachea-bronchus-lung area was about 5 micrograms/g of fresh tissue at the end of acute exposure, and 4 micrograms/g at the end of chronic exposure. The viral challenge was performed 48 hr after acute exposure, or on the 14th day after the beginning of chronic exposure, the mice being reexposed to Cd for an additional 14 days in the latter case. Surprisingly, the infectious death rate of test mice was significantly lower than that of controls, both for acute and chronic exposure to CdO. These results are discussed.

[Value of C-reactive protein in the cardiac postoperative period]

Twenty patients underwent special clinical and biological monitoring during their period of hospitalisation in the Department of cardiovascular surgery. The clinical monitoring concentrated on the patient's temperature and the search for postoperative complications; the biological part of the study was concerned with monitoring the levels of serum C-Reactive protein (CRP) as assessed by an immuno-nephelometric method. In 10 patients with a normal postoperative course the levels of this protein, an indicator of an inflammatory or infective process, were similar, giving an identical graph in all patients. On the other hand, in the 10 patients with inflammatory or infective postoperative complications, the levels of CRP were abnormal, parallel with the clinical state, sometimes rising even before the complication manifested itself clinically. It therefore seems useful and justified to measure CRP systematically, once before surgery and at least once daily in the postoperative period. The frequency of this investigation could be increased in patients with difficult or complex postoperative courses. A high CRP, even with a normal temperature, should alert the surgeon to a complication or to the inefficacy of anti-inflammatory or anti-infective therapy. These results confirm those published by other surgical teams, both in cardiovascular surgery and traumatology.

[Evaluation of bactericidal activity of antiseptics on the cutaneous flora of holoxenic hairless mouse]

Holoxenic Hairless mice were used in an experimental model to study the in vivo bactericidal activity of several antiseptics. In these experiments skin was sampled by biopsy; after contact between antiseptic and skin, bactericidal activity was neutralized. The results obtained with several products (polyvinylpyrrolidone iodine, alcoholic iodine, ethanol, chlorhexidin, benzalkonium chloride, mercurothiolic acid, trichlorocarbanilid and hexachlorophen) were quite similar to those obtained on human skin. The differences must be related to the composition of the Hairless mouse skin flora which contains Staphylococcus xylosus, Micrococcus sp. and Streptococcus faecalis, but does not contain Corynebacterium sp. or Propionibacterium sp.

The effect of alcohol ingestion on the susceptibility of mice to viral infections

The influence of acute alcoholization on the evolution of different viral diseases was studied in orally alcoholized mice. Ethanol increased mice susceptibility to encephalomyocarditis and influenza only when it was administered after virus infection. There was no dose-effect correlation. Vaccinia and Herpes virus infections were not modified by alcoholization. Hypotheses concerning the mechanisms of alcohol action were put forward.