Does the horizontal position increase risk of rescue death following suspension trauma?

BACKGROUND: It is widely believed that placing a patient who has been subjected to suspension trauma in a horizontal position after rescue may cause rescue death. The discussion whether position is important has been dominated by non-medical personnel. Subsequently, this has led to a general advice on emergency treatment of these patients, which may cause incorrect or even fatal treatment. METHODS: To determine whether there is any medical evidence supporting that horizontal positioning after suspension trauma may cause rescue death, the authors located publications, reports, expert opinions and other sources of information addressing the acute treatment of suspension trauma. These sources were then evaluated. RESULTS: Several thousand hits regarding suspension trauma were located on the internet and five articles on the PubMed. Although most of them warned of the dangers of rescue death brought about by assuming the horizontal position after prolonged suspension, the authors found no clinical studies, and none of the sources offered any conclusive evidence as to whether the horizontal position increases the risk of rescue death. Neither the authors, nor the suspension trauma experts who were contacted, had ever experienced or heard of case reports supporting the causal relation between the horizontal position and rescue death. CONCLUSIONS: After evaluating the current literature, the authors found no support for the view that the horizontal position may be potentially fatal for patients exposed to suspension trauma. In the absence of any evidence to the contrary, the authors suggest that the initial management of patients who have had suspension trauma should follow normal guidelines for the acute care of traumatised patients, without special modifications.

Dental health findings in a Native American settlement.

In 1951, A. Dahlberg took casts of 82 children aged 8-17 who lived in the Sac-Fox Settlement near Tama, Iowa. In 1990, the Indian Health Service supported a survey of 44 survivors from the 1951 study. All were contacted and 23 were examined. The findings from this study were compared with findings from similar aged Sac-Fox residents surveyed in 1982, and with the residents of Iowa of a similar age surveyed in 1980. The DMFS score of the 1990 Sac-Fox samples was larger (92.4) than that for the Iowa Survey (75.3). The periodontal findings were similar in the three samples, with one exception, the category 6+mm pockets were seen more frequently in the 1990 Sac-Fox sample (13.0%) than in the 1982 Sac-Fox (8.7%) and 1980 Iowa (2.9%) samples. Mucosal lesions were observed much more frequently in the Sac-Fox 1990 (69.6%) and 1982 (65.2%) samples, compared to the 1980 sample (8.6%). The frequency of totally edentulous persons was also much greater in the Sac-Fox samples, as compared to the Iowa Sample. It appears that the 1982 recommendations for making preventive procedures available to Sac-Fox adults is still appropriate in 1990.

High throughput DNA sequencing using an automated electrophoresis analysis system and a novel sequence assembly program.

The combination of high-resolution scanning, image-databasing technology and sequence assembly software makes it possible to assemble contiguous overlapping sequences of DNA in a fraction of the time required by manual methods. This paper describes and evaluates an assembly program that rapidly generates contigs from scanned images and provides a unique ability to verify disagreements between overlapping strands or fragments of complementary DNA sequences on-screen, further increasing sequencing throughput.

A microcomputer-based image analyzer for quantitating neurite outgrowth.

An automated device that recognizes and quantitates neurite outgrowth from goldfish retinal explants is described. The system components include a video camera-inverted microscope and an Apple II microcomputer with an attached Motorola 68000 coprocessor. Values for neurite outgrowth were generated within 30 s, required no user input other than defining the microscopic field, and correlated well with a subjective measure, the nerve growth index.

Dental size traits within families: path analysis for first molar and lateral incisor.

Previous works on the inheritance of dental traits have traditionally followed Fisher's model for family data under the assumption that phenotypic similarity between relatives is due solely to genetic factors. This study uses recent causal models that incorporate the contribution of nonrandom environmental sources of variation to familial resemblance on dental size. Path analysis was applied to observed interclass and intraclass correlations of sex-specific parent-offspring and sib pairs in 293 Pima Indian families from the southwest United States. The mesiodistal dimension of an early-forming and stable tooth (first molar) was contrasted with a late-forming and variable tooth (upper lateral incisor) for genetic and familial environmental components of variation. Parameters were estimated according to the XTAU models of Rice et al. (1980) and linear constraints placed upon the parameters were tested. The proportion of variance accounted for by genetic and environmental transmissible factors is estimated to be 52% for the first molar and 35% for the lateral incisor. Neither X-linkage nor sex-specific environmental effects are required to explain the transmission of dental size. Nontransmissible environmental effects that account for sibling correlations are detectable. Furthermore, sex differences are found in correlated sibling environments for the lateral incisor but not the first molar, to explain in part male-female differences in the distributions of the upper lateral incisor size.

The dental morphology of Pima Indians.

Fourteen morphologic crown traits were observed in a sample of 1528 Pima Indians of south-central Arizona. Pima dentitions are characterized by high frequencies of shoveling, incisor winging, the hypocone, the lower canine distal accessory ridge, cusp 6, and the protostylid. They exhibit low frequencies of the metaconule and lower premolar multiple lingual cusps and moderate frequencies of the canine tubercle, Carabelli's trait, cusp 7, and lower second molars with four cusps and X groove patterns. When Pima crown trait frequencies were compared to those of 13 Southwest Indian samples, their closest affinities were to other Uto-Aztecan groups, the Papago and Hopi. The Pima are most divergent from Athapaskans and are also clearly removed from Yuman speaking groups and the Zuni. In general, the pattern of dental morphologic variation in the Southwest corresponds closely to linguistic divisions.

The influence of crown size dimorphism on sex differences in the Carabelli trait and the canine distal accessory ridge in man.

When the two sexes were contrasted, Pima Indian males showed larger crown dimensions and more pronounced expressions of two morphologic variables, the Carabelli trait and the lower canine distal accessory ridge. In addition, a significant positive relationship was found between crown size and degree of expression of the morphologic traits. When regression analysis was utilized to control for male-female tooth size differences, the moderate dimorphism shown by Carabelli trait was reduced by about half. The more dimorphic distal accessory ridge, related primarily to mesio-distal diameter, also showed a lesser sex difference when crown size effects were held constant. While size dimorphism does contribute to morphologic dimorphism, factors unrelated to crown size still contribute the majority of variance present in trait expression both within and between sexes.

Quantitation of antibodies to Haemophilus influenzae type b in humans by enzyme-linked immunosorbent assay.

The enzyme-linked immunosorbent assay was adapted to detect serum immunoglobulin G, immunoglobulin M, immunoglobulin A, and secretory immunoglobulin A antibodies to Haemophilus influenzae type b capsular polysaccharide in humans. I studied serum samples from 92 healthy children of various ages, 50 healthy adults, 24 patients with various H. influenzae type b infections, and 16 patients with clinical signs of epiglottis and cellulitis suspected to be caused by H. influenzae type b. The mean antibody titers of the sera from healthy children increased with age and reached adult levels in children more than 6 years old. A significant antibody response to capsular polysaccharide was observed in serum samples from the majority of patients with infections due to H. influenzae type b and in 4 of 16 patients with clinical signs of epiglottis and cellulitis. In addition to the enzyme-linked immunosorbent assay, the antibody responses of patients were tested by a bactericidal assay. When the two methods were compared, there was no evident correlation (r, about 0.22). The enzyme-linked immunosorbent assay was further adapted to test secretory immunoglobulin A antibodies specific to capsular polysaccharide in nasopharynx secretions and in milk samples from lactating women. Antibodies were detected in 12 of 24 secretions and 9 of 11 milk samples.

Enzyme-linked immunosorbent assay for titration of Haemophilus influenzae capsular and O antigen antibodies.

The enzyme-linked immunosorbent assay (ELISA) was elaborated for the detection of immunoglobulin M (IgM) and IgG antibodies against capsular and O antigens of Haemophilus influenzae. Purified capsular polysaccharide and lipopolysaccharide were used as antigens, with optimal coating concentrations being about 50 and 100 micrograms/ml, respectively. The antibody content was expressed as the highest serum dilution (-log10) showing an absorbance of 0.2 above the background level. The titers of hyperimmune sera (reference sera) ranged between 5 and 7 -log10. The sensitivity of the method was about 80 ng/ml with regard to anticapsular antibodies and 3 to 5 ng/ml with regard to anti-lipopolysaccharide antibodies. For detection of antibodies against capsular polysaccharide in sera obtained after primary immunization, ELISA was about 100-fold more sensitive than the indirect hemagglutination assay, whereas in hyperimmune sera, ELISA was about 10-fold more sensitive than the indirect hemagglutination assay. The sensitivity of ELISA for detecting anticapsular antibodies after primary and booster immunizations was 50-fold higher than that of the bactericidal assay using capsulated bacteria, whereas the sensitivity of the two methods was the same when hyperimmune sera were tested. ELISA performed with lipopolysaccharide as the antigen was about 50- and 150-fold more sensitive than the complement fixation and bactericidal assays tested with noncapsulated variants after primary injection and hyperimmunization, respectively.

Characterization of the bactericidal antibody response against Haemophilus influenzae.

Rabbits were used in a study of the bactericidal (BC) antibody response against Haemophilus influenzae of types a and b and their respective non-capsulated variant strains. Previously described methods, complement fixation and indirect hemagglutination, were used for comparison. A bactericidal antibody response was demonstrable within a week after the primary immunization against capsulated as well as non-capsulated bacteria. After the hyperimmunization course the BC titres against noncapsulated bacteria were about 1:4,000, while the BC titres against the capsulated - type a and b-strains reached levels of no less than 1:30,000. Samples of separated hyperimmune sera showed BC activity in IgM- as well as IgG-containing fractions, whereas the BC activity of primary response samples was demonstrable mainly in IgM-containing fractions. The BC effect on non-capsulated bacteria of primary response samples were more heat labile than those obtained after hyperimmunization. In immune sera a crossreactive BC activity was demonstrable on non-capsulated bacteria, the titre being 32-64-fold lower than that of the homologous activity.

Study of antibody levels in children with purulent otitis media.

A series of episodes of acute otitis media were studied with reference to the bacterial findings in the nasopharynx and the specific antibody response in a group of children nine months to ten years of age, with previous frequent episodes of acute otitis media, Serum IgG, IgM and IgA antibody levels against five polysaccharide antigens, namely Haemophilus influenzae type b and Streptococcus pneumoniae types 3, 6, 19 and 23, were studied by means of an enzyme-linked immunosorbent assay. The selection of polysaccharide antigens was based on isolation frequency. The sera to be tested were tenfold serially diluted. An extinction of 0.2 over the base was taken as the end-point titer and expressed as in-log10. The results showed that most children including those under three years of age showed increasing homologous antibody titers at an infection, or had already initially very high antibody titers, especially of the IgG class. The titers reached levels of 10(4) to 10(5). In some cases, however, it could be shown that high serum antibody titers did not give protection against a new infection with the same serological type of bacteria. It was also demonstrated that most children, regardless of age, had IgG and IgM titers against the heterologous antigens. In some cases the levels were quite high (10(3) to 10(4)). However, the IgA antibody levels were lower and in a considerable number of samples antibodies were not even detectable.

Acute otitis media. A clinical bacteriological and serological study of children with frequent episodes of acute otitis media.

A series of episodes of acute otitis media was studied with reference to bacterial findings and specific serological responses in 48 children with histories of frequent episodes before. D. pneumoniae and H. influenzae were the most frequently isolated pathogens. Re-isolations after therapy were often made in episodes with slow healing or therapeutic failure. Most children harboured pathogens in nasopharynx even when they had no signs of respiratory tract infections. Homologous relapses were seen only in few cases and never with pneumococcus type 3 and only once with H. influenzae type b. Specific serological responses were demonstrable generally in children over 2 years of age. D. pneumococcus type 3 and H. influenzae type b generally provoked antibody response. No levels indicating immunoglobulin deficiencies could be found in the children.