Randomized, controlled trial of video self-instruction versus traditional CPR training

STUDY OBJECTIVE

We conducted a prospective, randomized, controlled trial to test the hypothesis that a 34-minute video self-instruction (VSI) training program for adult CPR would yield comparable or better CPR performance than the current community standard, the American Heart Association Heartsaver course.

METHODS

Incoming freshman medical students were randomly assigned to VSI or the Heartsaver CPR course. Two to 6 months after training, we tested subjects to determine their ability to perform CPR in a simulated cardiac arrest setting. Blinded observers used explicit criteria to assess our primary outcome, CPR performance skill. In addition, we assessed secondary outcomes including sequential performance of individual skills, ventilation and chest compression characteristics, and written tests of CPR-related knowledge and attitudes.

RESULTS

VSI trainees displayed superior overall performance compared with traditional trainees. Twenty of 47 traditional trainees (43%) were judged not competent in their performance of CPR, compared with only 8 of 42 VSI trainees (19%; absolute difference, 24%; 95% confidence interval, 5% to 42%).

CONCLUSION

In a group of incoming freshman medical students, we found that a half-hour of VSI resulted in superior overall CPR performance compared with that in traditional trainees. If validated by further research, VSI may provide a simple, quick, and inexpensive alternative to traditional CPR instruction for health care workers and, perhaps, the general population.

Systemic and local immune responses after parenteral influenza vaccination in juvenile diabetic patients and healthy controls: results from a pilot study

Diabetes patients suffer frequent complications and some excess mortality after influenza virus infection. Despite widespread agreement that diabetic patients should be routinely vaccinated against influenza, some reports claim that diabetics have a poor immune response to influenza vaccine. We have performed a pilot study to examine the humoral immune response of juvenile diabetics and matched healthy controls vaccinated with inactivated trivalent influenza vaccine. By enzyme-linked immunospot assay we found that both groups had comparable magnitude and kinetics of influenza-specific antibody secreting cell response. The influenza-specific antibody response in both serum and oral fluid were similar for both groups, and also showing a kinetic profile in accordance with our earlier data for healthy adults. Our study did not detect a difference in the humoral immune response between juvenile diabetics and healthy controls.

Catalytic self-acylation of type II polyketide synthase acyl carrier proteins

BACKGROUND

Aromatic polyketides are synthesised in streptomycetes by the successive condensation of simple carboxylic acids, catalysed by multienzyme complexes--the polyketide synthases (PKSs). Polyketide assembly intermediates are covalently linked as thioesters to the holo-acyl carrier protein (ACP) subunit of these type II PKSs. The ACP is primed for chain elongation by the transfer of malonate from malonyl CoA. Malonylation of fatty acid synthase (FAS) ACPs is catalysed by specific malonyl transferase (MT) enzymes. The type II PKS gene clusters apparently lack genes encoding such MT proteins, however. It has been proposed that the MT subunit of the FAS in streptomycetes catalyses malonylation of both FAS and PKS ACPs in vivo.

RESULTS

We demonstrate that type II PKS ACPs catalyse self-malonylation upon incubation with malonyl CoA in vitro. The self-malonylation reaction of the actinorhodin C17S holo-ACP has a K(m) for malonyl CoA of 219 microM and a kcat of 0.34 min-1. Complete acylation of the PKS ACPs was observed with malonyl, methylmalonyl and acetoacetyl CoAs. No reaction was observed with acetyl and butyryl CoAs and FAS ACPs did not react with any of the substrates. Recombinant FAS MT from Streptomyces coelicolor did not accelerate the rate of malonylation.

CONCLUSIONS

The catalytic self-acylation of type II PKS ACPs is an unprecedented reaction. We propose a reaction mechanism in which conserved arginines form a salt bridge with the acyl moiety and sequester it from bulk solvent. This work suggests that the beta-ketoacyl synthase, chain length factor and ACP may constitute a truly minimal PKS in vivo.

Post-translational modification of heterologously expressed Streptomyces type II polyketide synthase acyl carrier proteins

Expression in Escherichia coli of Streptomyces acyl carrier proteins (ACPs) associated with polyketide biosynthesis using the pT7-7 expression system of Tabor and Richardson led to the production predominantly of inactive apo-proteins lacking the 4'-phosphopantetheinyl prosthetic group essential for polyketide synthase activity. Modification of growth conditions led to an increase of production of active holo-protein for the actinorhodin (act) ACP, but this technique was ineffective for oxytetracycline (otc) and griseusin (gris) ACPs. Labelling experiments revealed that a low level of otc ACP expressed prior to induction was produced mainly as active holo-protein, while post-induction 15N-labelled protein was almost exclusively in the apo-ACP form. Limiting endogenous holo-acyl carrier protein synthase (ACPS) concentration was implicated as responsible for low apo-ACP to holo-ACP conversion, rather than limiting substrate (coenzyme A) and cofactor (Mg2+) concentrations. Co-expression of act and gris ACPs with ACPS in E. coli led to high levels of production of active holo-ACPs and ACPS. We have also made the significant observation that ACPS is able to transfer acylated CoA moieties to act apo-ACP.

Cross-reaction but no avidity change of the serum antibody response after influenza vaccination

Pre- and post-vaccination sera from 19 volunteers were analysed by the haemagglutination inhibition (HI) test, virus neutralization (VN) assay and avidity enzyme-linked immunosorbent assay (ELISA). The sera were tested against the three strains in a commercial inactivated influenza vaccine; A/Beijing/353/89(H3N2); A/Taiwan/1/86 (H1N1) and B/Yamagata/16/88. Additionally, a range of earlier strains and one newer isolate were assayed for HI- and VN-antibodies. Large variations in the pre-vaccination HI titres were observed for the viruses tested. However, 8-9 days after vaccination HI titres increased to above the assumed protective level (HI > or = 40) in most subjects. Although a limited number of patients were analysed at each sampling point, the time-profile we observed in this study is consistent with data we have obtained in earlier trials (Cox, R.J. et al., Vaccine 1994, 12,993-999). The VN titres, on the other hand, were low against all influenza strains before and up to 6 days, but increased rapidly 8-9 days after vaccination. A recent H3N2 isolate, A/Beijing/32/92 (H3N2), which had drifted further away from the vaccine strain, reacted to low titres or were negative in both the HI and VN assays. No change in the serum avidity to the influenza surface antigens was detected after vaccination, whereas sera from subjects naturally infected with influenza showed an increase in avidity to the infecting virus strain. The increase in serum avidity observed in the infected subjects is probably due to the increased and prolonged antigenic stimulus provided by the replicating virus.

Parenteral influenza vaccination induces a rapid systemic and local immune response

The kinetics of the local immune response in the upper respiratory tract to parenterally administered inactivated split trivalent influenza vaccine were examined in 19 healthy subjects. Influenza virus-specific antibody-secreting cells (ASC) could be detected as early as 2 days after vaccination in peripheral blood and tonsils, with a peak at approximately 1 week after vaccination and a decline to insignificant levels after 6 weeks. Circulating ASC produced IgG, IgA, and IgM, whereas ASC in tonsils produced mainly IgA and IgM. Influenza virus-specific antibodies were predominantly IgG and IgM in serum and IgA in oral fluid; they rose after 1 week and were elevated at 6 weeks. This may indicate a secretory involvement of the anti-influenza virus response in the upper respiratory tract. Parenteral influenza vaccination induced an immediate and significant immune response in both the upper respiratory tract and peripheral blood.

Nematodes associated with plants from naturally acidic wetlands soil

Four plants, Cyperus ochraceus, Eriocaulon compressum, Lythrum alatum, and Xyris jupicai, growing along the shoreline of an oligotrophic lake in north central Florida were sampled for nematodes. The nematodes recovered were placed in four trophic groups: bacterivores, herbivores, omnivores, and predators. When the nematodes on all plants were considered, 27% were bacterivores, 23% were herbivores, 7% were omnivores, and 43% were predators. Tripyla was the dominant predator and the dominant genus of all nematodes, and Malenchus was the dominant herbivore. Dominance was not clearly pronounced in the other trophic groups.

CompuTOD, a computer program to estimate time of death of deer

A statistical program named CompuTOD has been written which calculates the time since death of white-tailed deer. The data used for the regression analysis (n = 378) was obtained from a controlled hunt in 1982. The results obtained compare favorably with previous studies but additionally gives upper and lower confidence limits for the calculated time interval since death.

An early humoral immune response in peripheral blood following parenteral inactivated influenza vaccination

The enzyme-linked immunospot assay was used to examine the humoral immune response in 15 healthy volunteers immunized with either split or subunit inactivated trivalent influenza vaccine containing A/Beijing/353/89 (H3N2), A/Taiwan/1/86 (H1N1) and B/Yamagata/16/88. The rapidity of the individual B-cell and serum antibody response was examined in lymphocyte and serum samples collected at various time intervals after vaccination. A rapid serological response was detected with increases in antibody titre detected in the majority of volunteers by 7-8 days postvaccination. Influenza-specific plasma cells were detected as early as 4 days postvaccination, higher numbers of IgA and IgG antibody-secreting cells (ASC) were observed which peaked at 7-8 days postvaccination. The number of ASCs then declined, with low numbers of cells detected at 11 days postvaccination. Influenza-specific IgA ASCs were predominantly of the IgA1 subclass. This rapid immune response may have a bearing on future vaccination policies of unimmunized 'at risk groups' in times of high influenza activity.

Model for generating global images of emission from the thermosphere

A general model is presented for the production of images of thermospheric dayglow emissions. Ultraviolet images are generated that are relevant to remote sensing of the principal constituents of the thermosphere (O and N(2)) and the ionosphere (O(+)). The emission features considered here are 1356-Å (O), Lyman-Birge-Hopfield bands of N(2) between 1650 and 1715 Å, and 834 Å (O(+)). The MSIS-86 and International Reference Ionosphere models were used as climatological representations of the distributions of neutrals and ions, respectively. We describe the generation of the images beginning with the production of volume-emission-rate profiles. A detailed description of the generalized image-generation technique is given. This technique permits us to change the observer's altitude and viewing geometry without incurring a large computational burden. The images produced by this technique demonstrate the potential of airglow imaging systems for remote sensing of global variability in thermospheric composition.

Attenuation of virulence in influenza B viral infection of volunteers

A study was performed with volunteers in order to determine whether the virulence of an influenza B viral infection could be attenuated. Of a total of 62 persons, 26 received intranasal inoculations of an unpassaged influenza B virus isolate [virus U], while 26 received the same virus isolated passaged in cell culture and then in special pathogen-free embryonated hens' eggs [virus P]. The remaining 10 persons received uninoculated cell culture medium. Daily nasal wash samples were collected post-infection and scores for illness in the volunteers were evaluated. Viruses were isolated in cell culture and in eggs. Isolates were analysed by means of monoclonal antibodies (MAbs) raised against the influenza B viral haemagglutinin (HA) glycoprotein. One-step and nested polymerase chain reactions as well as direct nucleotide sequence analysis of part of the HA gene of the unpassaged specimens, together with the influenza B viruses isolated from those specimens, were performed. Nine of 26 volunteers who received the unpassaged virus became ill (illness scores from 13-84/100) whereas 7/26 of the volunteers who received the passaged virus had very mild illness (illness scores from 3-7/100). All the other volunteers remained well. Results of analysing the clinical specimens collected from the two groups of volunteers were compared. A difference in MAb reactivity, together with an aspartate for asparagine amino acid substitution at position 196 in a 432 base pair region of the viral HA gene, was observed. The loss of a potential glycosylation site at amino acid position 196-198 in the viral HA was associated with attenuation of virulence. This finding may have implications for the formulation of influenza vaccines.

Production responses in selenium supplemented sheep in northern New South Wales. 2. Liveweight gain, wool production and reproductive performance in young Merino ewes given selenium and copper supplements

Young Merino ewes on five commercial properties in northern New South Wales were supplemented with selenium and their production was compared with untreated flock mates. They were studied from weaning till first lambing at about two years of age. Treatments of 5 mg selenium were given orally every six weeks for approximately 12 months. Copper treatments were also included to test for a possible concurrent deficiency or interaction with selenium. There were significant responses to selenium in liveweight in four of the five flocks and in wool production in two of the flocks at both shearings. Reproductive performance at first mating was also significantly better in two flocks. There were no beneficial effects of copper treatment nor were there any significant interactions with selenium treatment in any aspect of production measured.

Localization of the parathyroid glands by intraoperative methylene blue staining

Exploration of the neck for primary hyperparathyroidism has increased in our institution, as evidenced by nine patients treated in the past one year, as compared with six in the previous three years. Our experience indicates that methylene blue staining has served as an important adjunct in the localization of abnormal parathyroid glands. No complications were noted intraoperatively or postoperatively as a result of its use. Operating time was measurably decreased. The results of this study support the routine use of methylene blue in both primary and secondary parathyroid exploration, and this is currently being done in our institution.

The effect of chronic anxiety level upon self control of heart rate

A sample of 90 subjects were rated on the IPAT anxiety scale and 5 subjects (3 male and 2 female) per group were selected from each of the high and low anxiety categories. All subjects were naive participants in heart rate biofeedback sessions utilising analogue visual feedback. Following a heart rate baseline (no feedback) session, all subjects were required to raise their heart rate and lower their heart rate in two separate trials, a visual "target" criteria being provided. The data collected consisted of a resting baseline heart rate value, mean heart rate increase, and mean heart decrease values expressed as beats per minute. Results indicated a marked ability for highly anxious subjects to self-induce heart rate increases only and for low anxious subjects to decrease their heart rate only.

Differentiation in Coprinus lagopus. III. Expansion of excised fruit-bodies

Fruit-body expansion was studied in Coprinus lagopus (sensu Buller) following surgical procedures. Elongation occurred after denuding mushroom caps of essentially all peripheral scales. Young primordia (1 - 5 mm) failed to develop after vertical bisection. Older primordia (e.g. 10 mm) expanded 3 - 4 fold after vertical bisection or quadrisection, underwent autolysis and basidiospore production. An amorphous brown gel in the stripe lumen disappeared during development of bisected primordia. Stripes isolated from primordia expanded autonomously and exhibited negative geotropism when incubated upside down or when the stripe apex was removed. Displacement of charcoal particles dusted on intact stripes revealed the most active zone of expansion to be the upper mid-region of the stripe. Segmented stripes likewise showed most active elongation in the mid-region. Vertically bisected stripes also expanded.