Australian bat lyssavirus infection: a second human case, with a long incubation period

In December 1998, a 37-year-old Queensland woman died from a rabies-like illness, 27 months after being bitten by a flying fox (fruit bat). Molecular techniques enabled diagnosis of infection with Australian bat lyssavirus (ABL), the second human case to be recognised and the first to be acquired from a flying fox. It must be assumed that any bat in Australia could transmit ABL; anyone bitten or scratched by a bat should immediately wash the wounds thoroughly with soap and water and promptly seek medical advice.

A self-recombining bacterial artificial chromosome and its application for analysis of herpesvirus pathogenesis

A self-recombining bacterial artificial chromosome (BAC) containing the 142-kb pseudorabies virus genome was constructed such that the viral genome is rapidly excised from the BAC vector backbone on delivery into mammalian cells. The recombination is mediated by loxP sites in the plasmid and Cre recombinase encoded within the BAC vector. A synthetic intron inserted in the middle of the cre ORF completely inhibits recombination in Escherichia coli, but is spliced out after delivery of the plasmid into mammalian cells. Recombination is efficient, and pure virus lacking the BAC vector backbone is immediately isolated from transfected mammalian cells without the need of serial passage or plaque purification.

An evaluation of a safety education program for kindergarten and elementary school children

OBJECTIVE

To determine the effectiveness of a safety education program, Safety City, that is designed to teach kindergarten and first grade children how to cross the street, call 911 in an emergency, and avoid strangers.

PARTICIPANTS/SETTING

Kindergarten students at 10 urban elementary schools.

DESIGN

Each school was randomized to either the intervention or control group. An evaluation tool was administered to all participants as a pretest. The Safety City program was then presented to the intervention schools. Afterward, the same evaluation tool was used as a post-test. The posttest was administered to the intervention group 6 months after the Safety City program was presented. The control group took the posttest 6 months after the pretest.

MAIN OUTCOME MEASURE

Change in individual test scores.

RESULTS

One hundred eighty-one children completed the pretest and posttest evaluations. There was no statistical difference in the change between pretest and posttest scores of children who participated in the Safety City program and those in the control group (crossing the street, P = .29; calling 911, P = .41; stranger avoidance, P = .57).

CONCLUSIONS

Exposure to the Safety City program did not achieve the desired changes in safety knowledge among participants. This is most likely owing to the fact that Safety City attempts to convey a large amount of relatively complex information to young children in a brief period. We conclude that programs such as Safety City are not sufficient to teach children these behaviors. This report also emphasizes the importance of building an evaluation component into educational programs.

Estimation of systolic and diastolic free intracellular Ca2+ by titration of Ca2+ buffering in the ferret heart

Spectroscopic Ca(2+)-indicators are thought to report values of free intracellular Ca(2+) concentration ([Ca(2+)](i)) that may differ from unperturbed values because they add to the buffering capacity of the tissue. To check this for the heart we have synthesized a new (19)F-labelled NMR Ca(2+) indicator, 1, 2-bis-[2-bis(carboxymethyl)amino-4,5-difluorophenoxy]ethane ('4, 5FBAPTA'), with a low affinity (K(d) 2950 nM). The new indicator and four previously described (19)F-NMR Ca(2+) indicators 1,2-bis-[2-(1 - carboxyethyl)(carboxymethyl)amino - 5 - fluorophenoxy]ethane ('DiMe-5FBAPTA'), 1, 2-bis-[2-(1-carboxyethyl)(carboxymethyl)amino-4-fluorophenoxy]ethane ('DiMe-4FBAPTA'), 1, 2-bis-[2-bis(carboxymethyl)amino-5-fluorophenoxy]ethane ('5FBAPTA') and 1, 2-bis-[2-bis(carboxymethyl)amino-5-fluoro-4-methylphenoxy]ethane ('MFBAPTA'), with dissociation constants for Ca(2+) ranging from 46 to 537 nM, have been used to measure [Ca(2+)](i), over the range from less than 100 nM to more than 3 microM, in Langendorff-perfused ferret hearts (30 degrees C, pH 7.4, paced at 1.0 Hz) by (19)F-NMR spectroscopy. Loading hearts with indicators resulted in buffering of the Ca(2+) transient. The measured end-diastolic and peak-systolic [Ca(2+)](i) were both positively correlated with indicator K(d). The positive correlations between indicator K(d) and the measured end-diastolic and peak-systolic [Ca(2+)](i) were used to estimate the unperturbed end-diastolic and peak-systolic [Ca(2+)](i) by extrapolation to K(d)=0 (diastolic) and to K(d)=infinity (systolic) respectively. The extrapolated values in the intact beating heart were 161 nM for end-diastolic [Ca(2+)](i) and 2650 nM for peak-systolic [Ca(2+)](i), which agree well with values determined from single cells and muscle strips.

Ca2+ buffering in the heart: Ca2+ binding to and activation of cardiac myofibrils

The measurement of cardiac Ca(2+) transients using spectroscopic Ca(2+) indicators is significantly affected by the buffering properties of the indicators. The aim of the present study was to construct a model of cardiac Ca(2+) buffering that satisfied the kinetic constraints imposed by the maximum attainable rates of cardiac contraction and relaxation on the Ca(2+) dissociation rate constants and which would account for the observed effects of (19)F-NMR indicators on the cardiac Ca(2+) transient in the Langendorff-perfused ferret heart. It is generally assumed that the Ca(2+) dependency of myofibril activation in cardiac myocytes is mediated by a single Ca(2+)-binding site on troponin C. A model based on 1:1 Ca(2+) binding to the myofilaments, however, was unable to reproduce our experimental data, but a model in which we assumed ATP-dependent co-operative Ca(2+) binding to the myofilaments was able to reproduce these data. This model was used to calculate the concentration and dissociation constant of the ATP-independent myofilament Ca(2+) binding, giving 58 and 2.0 microM respectively. In addition to reproducing our experimental data on the concentration of free Ca(2+) ions in the cytoplasm ([Ca(2+)](i)), the resulting Ca(2+) and ATP affinities given by fitting of the model also provided good predictions of the Ca(2+) dependence of the myofibrillar ATPase activity measured under in vitro conditions. Solutions to the model also indicate that the Ca(2+) mobilized during each beat remains unchanged in the presence of the additional buffering load from Ca(2+) indicators. The new model was used to estimate the extent of perturbation of the Ca(2+) transient caused by different concentrations of indicators. As little as 10 microM of a Ca(2+) indicator with a dissociation constant of 200 nM will cause a 20% reduction in peak-systolic [Ca(2+)](i) and 30 microM will cause approx. 50% reduction in the peak-systolic [Ca(2+)](i) in a heart paced at 1.0 Hz.

Interrelationships among biological markers of aging, health, activity, acculturation, and cognitive performance in late adulthood

In this study a structural equation model of predictors of age differences in cognitive performance in late adulthood was developed. Biological markers of aging (vision, hearing, vibration sense, forced expiratory volume, and grip strength) were used as indicators of a latent variable called BioAge. A sample of 180 community-dwelling women aged 60 to 90 years was assessed. Results showed that BioAge explained all of the age-related variance in cognitive test performance. Physical health and physical activity had direct effects on BioAge. Measures of acculturation explained non-age-related variance in cognitive test performance. Some variables used as biomarkers also explained individual differences in measures of crystallized intelligence and perceptual speed. It is concluded that the association between biomarkers and cognition in old age is due to more than a common statistical association with age.

Potential exposure to Australian bat lyssavirus, Queensland, 1996-1999

Two human deaths caused by Australian bat lyssavirus (ABL) infection have been reported since 1996. Information was obtained from 205 persons (mostly adults from south Brisbane and the South Coast of Queensland), who reported potential ABL exposure to the Brisbane Southside Public Health Unit from November 1,1996, to January 31, 1999. Volunteer animal handlers accounted for 39% of potential exposures, their family members for 12%, professional animal handlers for 14%, community members who intentionally handled bats for 31%, and community members with contacts initiated by bats for 4%. The prevalence of Lyssavirus detected by fluorescent antibody test in 366 sick, injured, or orphaned bats from the area was 6%. Sequelae of exposure, including the requirement for expensive postexposure prophylaxis, may be reduced by educating bat handlers and the public of the risks involved in handling Australian bats.

Interrelationships among biological markers of aging, health, activity, acculturation, and cognitive performance in late adulthood

In this study a structural equation model of predictors of age differences in cognitive performance in late adulthood was developed. Biological markers of aging (vision, hearing, vibration sense, forced expiratory volume, and grip strength) were used as indicators of a latent variable called BioAge. A sample of 180 community-dwelling women aged 60 to 90 years was assessed. Results showed that BioAge explained all of the age-related variance in cognitive test performance. Physical health and physical activity had direct effects on BioAge. Measures of acculturation explained non-age-related variance in cognitive test performance. Some variables used as biomarkers also explained individual differences in measures of crystallized intelligence and perceptual speed. It is concluded that the association between biomarkers and cognition in old age is due to more than a common statistical association with age.

American Academy of Pediatrics. Committee on Injury and Poison Prevention. Safe transportation of newborns at hospital discharge

All hospitals should set policies that require the discharge of every newborn in a car safety seat that is appropriate for the infant's maturity and medical condition. Discharge policies for newborns should include a parent education component, regular review of educational materials, and periodic in-service education for responsible staff. Appropriate child restraint systems should become a benefit of coverage by Medicaid, managed care organizations, and other third-party insurers.

Frequency of early colorectal cancer in patients undergoing colonoscopy

BACKGROUND

Early colorectal cancer is defined as carcinoma limited to the mucosa or submucosa. Up to 20 per cent of all colorectal cancers treated in some Japanese institutions are early cancers. These cancers are sometimes flat or depressed, and may be less than 1 cm in diameter. The aim of this study was to identify the frequency and morphology of early colonic cancers detected at colonoscopy by a surgeon aware of and looking for such lesions.

METHODS

A review was made of all colonoscopies performed by or under the supervision of a single endoscopist between 1990 and 1998. Follow-up and outcome of all patients with early colorectal cancer was undertaken.

RESULTS

Ninety-five invasive colorectal cancers were identified from 2198 colonoscopies. Eighteen were early colorectal cancers (T1). Macroscopically these were flat (nine tumours), villous (four) and pedunculated (five). Two patients had lymph node metastasis. The median size of flat cancers was 20 (range 9-30) mm. Median follow-up was 3 years. One patient had local recurrence, and another, whose early cancer was metachronous, died from metastatic cancer.

CONCLUSION

This study identified early colonic cancer with similar frequency and morphology to that reported by the Japanese. Colonoscopy should be considered as the investigation of choice for patients with large bowel symptoms.

American Academy of Pediatrics. Committee on Injury and Poison Prevention. Transporting children with special health care needs

Children with special health care needs should have access to proper resources for safe transportation. This statement reviews important considerations for transporting children with special health care needs and provides current guidelines for the protection of children with specific health care needs, including those with a tracheostomy, a spica cast, challenging behaviors, or muscle tone abnormalities as well as those transported in wheelchairs.

Analysis of the thymidine kinase genes of macropodid herpesviruses 1 and 2

The nucleotide sequences of the entire protein coding regions of the thymidine kinase (TK) genes of macropodid herpesvirus type 1 (MaHV-1) and type 2 (MaHV-2) were determined. The coding region of the MaHV-1 TK gene was 984 bp long and was predicted to encode a polypeptide of 327 amino acids. The coding region of the MaHV-2 TK gene was 1020 bp long and encoded a polypeptide of 340 amino acids. Comparisons of their deduced amino acid sequences with those of fifteen other herpesviruses revealed close homology to those of other alphaherpesviruses, particularly to human herpesvirus type 1 (HHV-1) and type 2 (HHV-2).

Molecular characterisation of Australian bovine enteroviruses

In this study we report the full length (7.4 kb) sequence of two Australian bovine enterovirus (BEV) isolates, K2577 and SL305 and the partial sequence of a third isolate, 66/27, which are the prototypes of the three major serological groups of BEV in Australia. Australian BEV isolates have not previously been related to the international classification of BEV into the major serotypes BEV-1 and BEV-2. The sequences of the three representative Australian isolates were compared to the full length sequence of a Northern Ireland isolate (VG527) classified as BEV-1, as well as two partial sequences of isolates from the United States and the United Kingdom classified as BEV-2. All three Australian isolates were classified as BEV-1 on the basis of closer nucleotide and amino acid similarity to the 5'-UTR and capsid proteins of VG527 than to the BEV-2 isolates (79-81% versus 76-77% nucleotide identity in the 5-UTR, and 86-98% versus 65-77% amino acid identity in the capsid proteins). These results indicate that most if not all Australian BEV are BEV-1. The remainder of the genome, which encodes non-structural proteins involved in viral replication, showed high sequence homology as has been observed among such genes in other enteroviruses. A system for full-length amplification of BEV isolates was also developed and the K2577 isolate was cloned to obtain a full-length, infectious DNA copy of the BEV genome. When RNA transcripts of BEV amplification products were transfected into MDBK cells infectious particles were produced. These virus particles were identical to the original virus isolates. This system can be used as a basis for the development of BEV-vectored vaccines as well in further molecular studies of bovine enteroviruses.

Reactivation of a macropodid herpesvirus from the eastern grey kangaroo (Macropus giganteus) following corticosteroid treatment

The family Herpesviridae is a large group of viruses which contain double stranded DNA genomes. Biological characteristics, such as host signs, site of replication and site of latency have been used to describe three major subfamilies, Alphaherpesvirinae, Betaherpesvirinae and Gammaherpesvirinae within the family Herpesviridae. Macropodid herpesviruses (MaHV) have been implicated in fatal outbreaks amongst the captive marsupial populations of Australia. These outbreaks have resulted in the isolation of nine MaHV strains which have been classified into two species called macropodid herpesvirus 1 and 2 (MaHV-1 and MaHV-2). Biological characteristics have been used to place MaHV-1 and -2 within the subfamily Alphaherpesvirinae. Molecular phylogenetic reconstructions indicate an unusual position for MaHV-1 and -2 within the alphaherpesviruses. Current isolates of MaHVs have all been obtained from marsupials exhibiting clinical disease. A common biological characteristic of herpesviruses is the establishment of latent infections in nervous tissue. We have determined that MaHV are able to latently infect eastern grey kangaroos through reactivating and isolating a herpesvirus by inducing immunosuppression. We have investigated the possible sites of latency for MaHV-1 using molecular techniques. Detection of herpesvirus DNA in the trigeminal ganglia taken from two naturally infected eastern grey kangaroos indicates dissemination via a respiratory route.

Construction and transposon mutagenesis in Escherichia coli of a full-length infectious clone of pseudorabies virus, an alphaherpesvirus

A full-length clone of the 142-kb pseudorabies virus (PRV) genome was constructed as a stable F plasmid in Escherichia coli. The clone, pBecker1, was colinear with PRV-Becker genomic DNA, lacking detectable rearrangements, deletions, or inversions. The transfection of pBecker1 into susceptible eukaryotic cells resulted in productive viral infection. Virus isolated following transfection was indistinguishable from wild-type virus in a rodent model of infection and spread to retinorecipient regions of the brain following inoculation in the vitreous body of the eye. Mutagenesis of pBecker1 in E. coli with a mini-Tn5-derived transposon enabled the rapid isolation of insertion mutants, identification of essential viral genes, and simplified construction of viral revertants. The serial passage of a viral insertion mutant demonstrated the transposon insertion to be stable. However, the F-plasmid insertion present in the viral gG locus was found to undergo a spontaneous deletion following transfection into eukaryotic cells. The implications of F-plasmid insertion into the viral genome with regard to phenotype and genomic stability are discussed.

Rapid phenotyping of HPA-1a using either diabody-based hemagglutination or recombinant IgG1-based assays

BACKGROUND

The HPA-1 system is carried on the beta3 integrin. HPA-1a (Zw(a), Pl(A1)) is immunogenic in an HPA-1b homozygote (HPA-1b1b). In pregnancy, 1 of 365 women forms anti-HPA-1a, which causes severe thrombocytopenia in 1 in 1100 neonates. Identification of women at risk of forming anti-HPA-1a and the screening of donors to obtain HPA-1a-negative platelets for therapy need reliable, low-cost, automated assays.

STUDY DESIGN AND METHODS

A diabody with dual specificity for HPA-1a x D and an IgG1 anti-HPA-1a have been constructed by the use of the genes encoding the first anti-HPA-1a fragment. With these reagents, two complementary HPA-1a phenotyping assays have been developed.

RESULTS

This diabody was used in a simple hemagglutination technique to perform HPA-1a phenotyping on soluble glycoprotein IIb/IIIa from EDTA plasma samples. Over 1000 unselected donors have been correctly HPA-1a-phenotyped by use of the diabody. The human recombinant IgG1 anti-HPA-1a was produced in a rat myeloma cell line and was fluorescein labeled for use in a whole-blood flow cytometric HPA-1a phenotyping assay. This IgG1 anti-HPA-1a shows a clear differential between HPA-1a-positive and HPA-1a-negative platelets at nM antibody concentrations.

CONCLUSIONS

The two recombinant reagents described are highly suitable for screening and confirmatory HPA-1a phenotyping. They permit rapid determination of the HPA-1a phenotype and are amenable to automation.

Crystal structure of substrate complexes of methylmalonyl-CoA mutase

X-ray crystal structures of methylmalonyl-CoA mutase in complexes with substrate methylmalonyl-CoA and inhibitors 2-carboxypropyl-CoA and 3-carboxypropyl-CoA (substrate and product analogues) show that the enzyme-substrate interactions change little during the course of the rearrangement reaction, in contrast to the large conformational change on substrate binding. The substrate complex shows a 5'-deoxyadenine molecule in the active site, bound weakly and not attached to the cobalt atom of coenzyme B12, rotated and shifted from its position in the substrate-free adenosylcobalamin complex. The position of Tyralpha89 close to the substrate explains the stereochemical selectivity of the enzyme for (2R)-methylmalonyl-CoA.

Hepatitis A outbreaks among illicit drug users and their contacts in Queensland, 1997

OBJECTIVE

To describe five outbreaks of hepatitis A virus (HAV) infection associated with illicit drug use during a statewide outbreak of HAV infection in Queensland.

DESIGN

Risk factor prevalence survey.

PATIENTS AND SETTING

All 875 cases of HAV infection notified to Public Health Units in Queensland in the 12 months to 30 November 1997.

MAIN OUTCOME MEASURE

Type and prevalence of illicit drug use.

RESULTS

Risk factor assessment was completed for 804 cases (91.9%). We identified five outbreaks of HAV infection linked to illicit drug use. These outbreaks accounted for 24.6% (215/875) of all notified cases and 39% (190/482) of notified cases in the 15-34 years age group. The main type of illicit drug use in four of the five outbreaks was injecting drug use (74%; 118/160), while in the other outbreak it was sharing of smoking implements for marijuana (38%; 21/55).

CONCLUSION

Illicit drug use may be an under-recognised risk factor for HAV infection, particularly in young people. Faecal-oral transmission through poor personal hygiene, including sharing of implements for smoking marijuana, is the most probable route of transmission in these drug-linked outbreaks. The role of contaminated drug and needle-sharing remains to be clarified.

Effects of fluorinated inositols on the phosphoinositide metabolism and the proliferation of Trypanosoma cruzi

Inositol has been cited as being essential for the growth of micro-organisms and animals. Its action rests mostly in the formation of a set of inositol-containing lipids, including phosphatidylinositol and its phosphorylated derivatives. To evaluate the functional responses coupled to the phosphoinositide metabolism in Trypanosoma cruzi we used myo-inositol and its six fluorinated analogues. Their uptake into epimastigotes was characterised using tritium-labeled myo-inositol and monodeoxyfluoro-myo-inositols. The analogues were tested for their ability to inhibit [3H]-myo-inositol incorporation into phosphoinositides and the proliferation of epimastigotes and amastigotes. The results showed differences between T. cruzi and mammalian systems in the responses to the fluorinated analogues. We found that the 3-, 5- and 6-fluoro analogues did not enter the cells but had an inhibitory effect on the incorporation of the radioactive inositol into lipids and on the amastigotes' and epimastigotes' replication. The most effective inhibitor, 1-D-6-deoxy-6-myo-inositol, had no effect on mammalian cell division.

Macropodid herpesviruses 1 and 2 occupy unexpected molecular phylogenic positions within the Alphaherpesvirinae

The molecular phylogeny of macropodid herpesviruses 1 and 2 (MaHV-1 and -2) has been investigated by cloning and sequencing the genes encoding glycoprotein B from both viruses. Phylogenetic reconstructions based on the putative amino acid sequences of glycoprotein B indicate that MaHV-1 and -2 are most closely related to the subfamily Alphaherpesvirinae. Within the Alphaherpesvirinae, MaHV-1 and -2 are closely associated with those herpesviruses that infect primates. This phylogenetic relationship does not fit the constraints of the proposed co-evolution theory described for other members of the Alphaherpesvirinae which have mammalian hosts.

The hospital record of the injured child and the need for external cause-of-injury codes. American Academy of Pediatrics. Committee on Injury and Poison Prevention, 1998-1999

Proper record-keeping of emergency department visits and hospitalizations of injured children is vital for appropriate patient management. Determination and documentation of the circumstances surrounding the injury event are essential. This information not only is the basis for preventive counseling, but also provides clues about how similar injuries in other youth can be avoided. The hospital records have an important secondary purpose; namely, if sufficient information about the cause and mechanism of injury is documented, it can be subsequently coded, electronically compiled, and retrieved later to provide an epidemiologic profile of the injury, the first step in prevention at the population level. To be of greatest use, hospital records should indicate the "who, what, when, where, why, and how" of the injury occurrence and whether protective equipment (eg, a seat belt) was used. The pediatrician has two important roles in this area: to document fully the injury event and to advocate the use of standardized external cause-of-injury codes, which allow such data to be compiled and analyzed.

Diagnostic aids in the differentiation of pyloric stenosis from severe gastroesophageal reflux during early infancy: the utility of serum bicarbonate and serum chloride

This study evaluated whether serum bicarbonate levels, serum chloride levels, and other diagnostic criteria could be used to differentiate pyloric stenosis (PS) from severe gastroesophageal reflux (GER) during early infancy. The investigation was a retrospective, case-control study conducted in the emergency department of a large, academic children's hospital. Cases were 75 consecutive infants with PS confirmed in the operating room. Controls were 75 consecutive infants 12 weeks of age or younger with the diagnosis of GER whose serum electrolytes had been examined. Projectile vomiting was sensitive (0.93) but not specific (0.39) for PS. The mean serum bicarbonate level was 27.2 mmol/L for PS patients and 22.3 mmol/L for GER patients (P < .00001), and the mean serum chloride level was 95.7 mmol/L and 103.6 mmol/L for PS patients and GER patients, respectively (P < .00001). Serum bicarbonate levels of > or =29 mmol/L and serum chloride levels of < or =98 mmol/L had high positive predictive values (0.96 and 0.97, respectively) and were specific (0.99 for both) but not very sensitive (0.36 and 0.50, respectively) in identifying patients with PS. Only one patient would have been misclassified (false positive) as having PS using either of these cutoff values. These laboratory tests can also help discriminate between PS and GER when the history and physical examination fail to do so. For example, of the 20 patients with PS who did not have a pyloric mass palpated, 3 (15%) had serum bicarbonate levels of > or =29 mmol/L, and 6 (30%) had serum chloride levels of < or =98 mmol/L. In conclusion, the serum bicarbonate or serum chloride level offers a useful additional diagnostic tool in the evaluation of children presenting during early infancy with vomiting of uncertain etiology.

The Modified Card Sorting Test: test-retest stability and relationships with demographic variables in a healthy older adult sample

OBJECTIVES

To investigate the test-retest stability of a standardized version of Nelson's (1976) Modified Card Sorting Test (MCST) and its relationships with demographic variables in a sample of healthy older adults.

DESIGN

A standard card order and administration were devised for the MCST and administered to participants at an initial assessment, and again at a second session conducted a minimum of six months later in order to examine its test-retest stability. Participants were also administered the WAIS-R at initial assessment in order to provide a measure of psychometric intelligence.

METHODS

Thirty-six (24 female, 12 male) healthy older adults aged 52 to 77 years with mean education 12.42 years (SD = 3.53) completed the MCST on two occasions approximately 7.5 months (SD = 1.61) apart. Stability coefficients and test-retest differences were calculated for the range of scores. The effect of gender on MCST performance was examined. Correlations between MCST scores and age, education and WAIS-R IQs were also determined.

RESULTS

Stability coefficients ranged from .26 for the percent perseverative errors measures to .49 for the failure to maintain set measure. Several measures were significantly correlated with age, education and WAIS-R IQs, although no effect of gender on MCST performance was found.

CONCLUSIONS

None of the stability coefficients reached the level required for clinical decision making. The results indicate that participants' age, education, and intelligence need to be considered when interpreting MCST performance. Normative studies of MCST performance as well as further studies with patients with executive dysfunction are needed.

Effects of noradrenaline on intracellular pH in acutely dissociated adult rat hippocampal CA1 neurones

1. We examined the effects of noradrenaline on steady-state intracellular pH (pHi) and the recovery of pHi from internal acid loads imposed by the NH4+ prepulse technique in hippocampal CA1 neurones acutely dissociated from adult rats. 2. Under nominally HCO3--free conditions, acid extrusion was accomplished by a Na+-dependent mechanism, probably the amiloride-insensitive variant of the Na+-H+ exchanger previously characterized in both fetal and adult rat hippocampal neurones. In the presence of external HCO3-, acid extrusion appeared to be supplemented by a Na+-dependent HCO3--Cl- exchanger, the activity of which was dependent upon the absolute level of pHi. 3. Noradrenaline evoked a concentration-dependent and sustained rise in steady-state pHi and increased rates of pHi recovery from imposed intracellular acid loads. The effects of noradrenaline were not dependent upon the presence of external HCO3- but were blocked by substituting external Na+ with N-methyl-D-glucamine, suggesting that noradrenaline acts to increase steady-state pHi by increasing the activity of the Na+-H+ exchanger. 4. The effects of noradrenaline on steady-state pHi and on rates of pHi recovery from imposed acid loads were mimicked by beta1- and beta2-, but not alpha-, adrenoceptor agonists. The beta-adrenoceptor antagonist propranolol blocked the ability of noradrenaline to increase both steady-state pHi and rates of pHi recovery from acid loads. 5. The effects of noradrenaline on steady-state pHi and on pHi recovery rates following acid loads were not dependent on changes in [Ca2+]i. However, the effects of noradrenaline were blocked by pre-treatment with the adenylate cyclase inhibitor 2',5'-dideoxyadenosine and the cAMP-dependent protein kinase inhibitors Rp-adenosine-3',5'-cyclic monophosphorothioate (sodium salt; Rp-cAMPS) and N-[2-(p-bromocinnamylamino)ethyl]-5-isoquinolinesulphonamide (H-89). 6. Forskolin, an activator of endogenous adenylate cyclase, and 3-isobutyl-1-methylxanthine, a phosphodiesterase inhibitor, mimicked the ability of noradrenaline to increase both steady-state pHi and rates of pHi recovery from imposed acid loads, as did Sp-cAMPS, a selective activator of cAMP-dependent protein kinase. The effect of forskolin on steady-state pHi was blocked by pre-treatment with Rp-cAMPS whereas the effect of Sp-cAMPS was enhanced by pre-treatment with the protein phosphatase inhibitor, okadaic acid. 7. Noradrenaline also increased steady-state pHi and rates of pHi recovery from imposed acid loads in cultured postnatal rat hippocampal neurones. In this preparation, the effects of noradrenaline were occluded by 18-24 h pre-treatment with cholera toxin. 8. We conclude that noradrenaline increases the activity of the Na+-H+ exchanger in rat hippocampal neurones, probably by inducing an alkaline shift in the pHi dependence of the antiport, thereby raising steady-state pHi. The effects of noradrenaline are mediated by beta-adrenoceptors via a pathway which involves the alpha-subunit of the stimulatory G-protein Gs (Gsalpha), adenylate cyclase, cAMP and the subsequent activation of cAMP-dependent protein kinase which, in turn, may phosphorylate the exchange mechanism.

Prilocaine-phenylephrine topical anesthesia for repair of mucous membrane lacerations

OBJECTIVE

To compare the effectiveness of prilocaine-phenylephrine (Prilophen), a new topical anesthetic that does not contain cocaine, to that of lidocaine infiltration during repair of lacerations on or near mucous membranes in children.

DESIGN

A prospective, randomized, blinded trial.

SETTING

The emergency department of a large academic children's hospital.

PATIENTS

Children one year of age or older with a laceration 5 cm or less in length on or near a mucous membrane.

INTERVENTIONS

Forty patients were randomly assigned one of the two local anesthetics, with 20 patients in each treatment group.

OUTCOME MEASURES

Pain felt during suturing was scored by suture technicians, research assistants, a videotape reviewer, parents, and patients five years of age and older using a visual analog scale (VAS).

RESULTS

There was no statistically significant difference in performance between topical Prilophen and lidocaine infiltration when VAS pain scores of research assistants, parents, and patients were compared. However, lidocaine infiltration performed significantly better than topical Prilophen when comparing VAS scores of suture technicians (P = 0.003) and the videotape reviewer (P = 0.02). When power analyses were performed using alpha = 0.05 and beta = 0.20, it was possible to detect a difference of 2 units for VAS scores of suture technicians, 2 VAS units for research assistants, 3 VAS units for the videotape reviewer and parents, and 7 VAS units for patients. There were no wound healing or other complications.

CONCLUSIONS

Prilophen is a new topical anesthetic alternative to lidocaine infiltration for closure of lacerations on or near mucous membranes, where use of tetracaine-adrenaline-cocaine is contraindicated. The performance of Prilophen was rated by two of the observer groups as statistically inferior to that of lidocaine infiltration; however, the differences in pain scores were small and may not be clinically significant. Further investigation of this new topical anesthetic is warranted.

Changes in ventricular repolarization during acidosis and low-flow ischemia

Myocardial ischemia, primarily a metabolic insult, is also defined by altered cardiac mechanical and electrical activity. We have investigated the metabolic contributions to the electrophysiological changes during low-flow ischemia (7.5% of the control flow) using 31P NMR spectroscopy to monitor metabolic parameters, suction electrodes to study epicardial monophasic action potentials, and 86Rb as a tracer for K+-equivalent efflux during low-flow ischemia in the Langendorff-perfused ferret heart. Shortening of the action potential duration at 90% repolarization (APD90) was most marked between 1 and 5 min after induction of ischemia, at which time it shortened from 261 +/- 4 to 213 +/- 8 ms. The period of marked APD90 shortening was accompanied by a fivefold increase in the rate of 86Rb efflux, both of which were inhibited by the ATP-sensitive K+ (KATP)-channel blockers glibenclamide and 5-hydroxydecanoate (5-HD), as well as by a significant fall in intracellular pH (pHi) from 7.14 +/- 0.02 to 6.83 +/- 0.03 but no change in intracellular ATP concentration ([ATP]i). We therefore investigated whether a fall in pHi could be the metabolic change responsible for modulating cardiac KATP channel activity in the intact heart during ischemia. Both metabolic (30 mM lactate added to extracellular solution) and respiratory (PCO2 increased to 15%) acidosis caused an initial lengthening of APD90 to 112 +/- 1.5 and 113 +/- 0.9%, respectively, followed by shortening during continued acidosis to 106 +/- 1.2 and 106 +/- 1.4%, respectively. The shortening of APD90 during continued acidosis was inhibited by glibenclamide, consistent with acidosis causing activation of KATP channels at normal [ATP]i. The similar responses to metabolic (induced by adding either l- or d-lactate) and respiratory acidosis suggest that lactate has no independent metabolic effect on action potential repolarization.

Trampoline-related injuries to children

OBJECTIVE

To describe the epidemiological features of trampoline-related injuries among children treated in an urban pediatric emergency department.

DESIGN

A descriptive study of a consecutive series of patients.

SETTING

The emergency department of a large, urban, academic children's hospital.

PARTICIPANTS

Children treated for trampoline-related injuries from May 1, 1995, through April 30, 1997.

RESULTS

Two hundred fourteen children were treated for trampoline-related injuries during the study period, representing, on average, 1 child treated approximately every 3 days. Children ranged in age from 1 to 16 years (mean [SD], 9.4 [3.6] years). The area of the body most commonly injured was a lower extremity (36.0%), followed by an upper extremity (31.8%), the head (14.5%), the trunk (9.8%), and the neck (7.9%). The most common type of injury was a soft tissue injury (51.9%), followed by fracture (34.6%) and laceration (11.7%). Several patterns of trampoline-related injury were identified. Extremity fractures were more common in the upper extremities (P=.006; relative risk [RR]=1.64; 95% confidence interval [CI], 1.16-2.31); however, soft tissue injuries were more common in the lower extremities (P=.006; RR=1.66; 95% CI, 1.16-2.38). Lacerations were associated with injury to the head region (P<.001; RR=67.9; 95% CI, 16.8-273.6) and were more common among children younger than 6 years (P=.02; RR=2.58; 95% CI, 1.24-5.34). Soft tissue injuries were more common among children 6 years of age and older (P=.01; RR=1.66; 95% CI, 1.08-2.55). Four patients (1.9%) with fractures were admitted to the hospital. The trampoline was located in the backyard in 96% (119/124) of cases. Adult supervision was present at the time of injury for 55.6% (65/117) of children, including 73.3% (22/30) of children younger than 6 years. Parents reported that they had been aware of the potential dangers of trampolines before the injury event (73% [81/111]), that their child had previously attempted a flip on a trampoline (56.9% [66/116]), that this was not the child's first injury on a trampoline (10% [12/120]), and that their child continued to use a trampoline after the current injury event (54.8% [63/115]).

CONCLUSIONS

Trampoline-related injuries to children treated in the emergency department are almost exclusively associated with the use of backyard trampolines. The prevention strategies of warning labels, public education, and adult supervision are inadequate to prevent these injuries. Children should not use backyard trampolines, and the sale of trampolines for private recreational use should be halted.

Tetracaine-lidocaine-phenylephrine topical anesthesia compared with lidocaine infiltration during repair of mucous membrane lacerations in children

This study compared the effectiveness of a new topical anesthetic, tetracaine-lidocaine-phenylephrine (TetraLidoPhen), with that of lidocaine infiltration during repair of mucous membrane lacerations in children. It was conducted in the emergency department of an urban children's hospital with use of a prospective, randomized, blinded study design. Participants were 90 children 1 year of age or older with a laceration 5 cm or less in length on or near a mucous membrane that required suturing. They were randomly assigned to one of two treatment groups, with 45 patients in each group. Pain felt during suturing was scored by suture technicians, research assistants, a videotape reviewer, parents, and patients 5 years of age and older using a Visual Analogue Scale (VAS). Suture technicians, research assistants, a videotape reviewer, and parents also scored pain using a seven-point Likert scale. In addition, suture technicians completed an Anesthesia Effectiveness scale and a Wound Blanching scale. The laceration was located near the eyes in 71 patients (79%), and on or near the lips in 19 (21%). Lidocaine infiltration performed significantly better than topical TetraLidoPhen in comparisons of Likert scores of suture technicians (P = 0.007), research assistants (P = 0.005), the videotape reviewer (P = 0.003), and parents (P = 0.03); Anesthetic Effectiveness scale scores of suture technicians (P = 0.00002; relative risk (RR) = 1.83, 95% confidence interval 1.36 < RR < 2.46); and VAS scores of suture technicians (P = 0.002), research assistants (P = 0.001), and the videotape reviewer (P = 0.005). No significant difference in performance was detected between lidocaine and TetraLidoPhen in comparing VAS scores of parents and patients. There was a 4.4% wound complication rate, including two (2.2%) wound infections. The authors conclude that TetraLidoPhen is a new topical anesthetic that appears to be safe when applied on or near mucous membranes. Its performance among study participants was statistically inferior to that of lidocaine infiltration; however, the differences in pain scores were small and may not be clinically significant. Also, comparisons of pain scores in this study did not take into account the pain associated with the initial injection of lidocaine. Therefore, study findings may underestimate the comparative performance of TetraLidoPhen. Further investigation of this new topical anesthetic is warranted.

Clinical criteria for using radiography for children with acute knee injuries

OBJECTIVE

To evaluate clinical criteria for selective radiography for knee injuries in children.

DESIGN

Retrospective chart review.

SETTING

Emergency department (ED) of a children's hospital.

PARTICIPANTS

All patients evaluated by radiography for an isolated, acute knee injury during 12 months. Patients were excluded for injuries: >1 week; isolated to superficial lacerations/abrasions; with prior knee surgery; being reassessed.

RESULTS

Two hundred fifty-four patients (60% male; 12.7 years median age) were included. Twelve patients (4.7%) sustained a fracture. Evaluated criteria were point tenderness, inability to bear weight in the ED, and inability to flex the knee to 90 degrees. Point tenderness was not statistically associated with fracture, P = 0.7. Inability to bear weight in the ED (37% fracture rate, P = 0.001) and inability to flex to 90 degrees (52% fracture rate, P < 0.001) were associated with the presence of fracture.[table in text] Applying a rule combining nobearwt and noflex90 would decrease the number of x-rays by 73%, with no missed fractures.

CONCLUSIONS

Point tenderness was not a good predictor of knee fracture in children. Using the clinical criteria to select patients requiring knee radiography may greatly reduce the number of unnecessary x-rays.

Prefrontal cortex involvement in selective letter generation: a functional magnetic resonance imaging study

Cerebral responses to alternating periods of a control task and a selective letter generation paradigm were investigated with functional Magnetic Resonance Imaging (fMRI). Subjects selectively generated letters from four designated sets of six letters from the English language alphabet, with the instruction that they were not to produce letters in alphabetical order either forward or backward, repeat or alternate letters. Performance during this condition was compared with that of a control condition in which subjects recited the same letters in alphabetical order. Analyses revealed significant and extensive foci of activation in a number of cerebral regions including mid-dorsolateral frontal cortex, inferior frontal gyrus, precuneus, supramarginal gyrus, and cerebellum during the selective letter generation condition. These findings are discussed with respect to recent positron emission tomography (PET) and fMRI studies of verbal working memory and encoding/retrieval in episodic memory.

(E)-5-(2'-bromovinyl)-2'-deoxyuridine inhibition of macropodid herpesvirus 1 in vitro

Herpesviruses have caused the death of kangaroos and wallabies in European and North American zoos. Eight antiherpetic purine or pyrmidine nucleoside compounds were tested in plaque reduction neutralization tests for in vitro inhibition of macropodid herpesvirus 1, a virus that has been associated with illness in captive macropods in Australia. The virus was most susceptible to inhibition by (E)-5-(2'-bromovinyl)-2'-deoxyuridine (BVDU) and 5'-iodo-2'-deoxycytidine. Because BVDU effectively inhibits macropodid herpesvirus 2 in vitro, it may be the drug of choice for experimental therapy in herpesvirus infections in captive macropodids.

The summer penile syndrome: seasonal acute hypersensitivity reaction caused by chigger bites on the penis

OBJECTIVE

To describe the seasonal acute hypersensitivity reaction of the penis due to chigger bites, known as the summer penile syndrome.

DESIGN

A consecutive series of patients.

SETTING

The emergency department of an urban academic children's hospital in the midwestern United States.

PARTICIPANTS

Male pediatric patients with an acute hypersensitivity reaction of the penis.

RESULTS

Ninety-four patients were treated for summer penile syndrome during the four-month period from June through September. Patients ranged in age from seven months to 11 years (mean = 5.1, SD = 2.5). Twenty-one percent of patients had also experienced a similar prior episode of penile swelling. Symptoms included pruritus in 84% of cases, dysuria in 33%, and decreased strength of urine stream in 8% of patients. Eighty-four percent of patients had recent exposure to the woods, park, lawn, or poison ivy. In addition to edema, findings on physical examination included a papule or bite puncture mark in 50% of patients, erythema in 32%, and excoriation in 6% of patients. Fifty-six percent of patients had bites on other areas of the body. The emergency physician attributed the penile edema to an insect or chigger bite in 98% of cases. Treatment consisted of an oral antihistamine and cold compresses in most cases. The reported duration of penile swelling ranged from one to 18 days with a mean of 4.1 days (SD = 3.5), and the reported duration of pruritus ranged from 0 to 14 days with a mean of 3.0 days (SD = 2.6).

CONCLUSION

This study provides an understanding of the summer penile syndrome for pediatric care providers. To our knowledge, this study is the first to describe this seasonal syndrome in the medical literature.

Injuries to children in the United States related to trampolines, 1990-1995: a national epidemic

STUDY OBJECTIVE

To describe the epidemiology of trampoline-related injuries among children in the United States.

DESIGN

A retrospective analysis of data for children 18 years old and younger from the National Electronic Injury Surveillance System of the United States Consumer Product Safety Commission for 1990 through 1995.

RESULTS

There were an estimated 249 400 trampoline-related injuries [95% confidence interval (CI), 166 300-332 500] to children 18 years old and younger treated in hospital emergency departments in the United States during the 6-year study period. The number of injuries increased by 98% from 29 600 in 1990 to 58 400 in 1995, with an average of 41 600 (95% CI, 27 700-55 500) injuries per year, or 59.4 injuries per 100 000 United States children per year (95% CI, 39.6-79.3). The median age of injured children was 10 years, and 50% were males. Ninety-three percent of injuries occurred at home. Injuries to the extremities predominated among children of all ages and accounted for more than 70% of all injuries. This study identified several age-specific injury patterns. There was an inverse relationship between age versus the relative frequency of upper extremity injuries, and fractures and dislocations; and there was a direct relationship between age versus lower extremity injuries and soft tissue injury. There was also an inverse relationship between age versus facial injuries, head and neck injuries, and lacerations. Annually, an estimated 1400 children (95% CI, 800-2000), or 2.0 per 100 000 United States children (95% CI, 1. 1-2.9), required hospital admission or interhospital transfer because of a trampoline-related injury. This represented 3.3% of all children with a trampoline-associated injury. Fractures or dislocations accounted for 83% of injuries among admitted or transferred children, and children with a fracture or dislocation were more likely to be admitted or transferred to another hospital (8.4%) than children with other types of injury (relative risk, 10.80; 95% CI, 9.40 < relative risk < 12.29). Among children released home from the emergency department, soft tissue injuries (53%), fractures or dislocations (30%), and lacerations (14%) were the most common injuries treated.

CONCLUSION

Injuries related to trampolines, especially backyard trampolines, are an important cause of pediatric morbidity. These injuries have also resulted in death. The rapid increase in the number of trampoline-related injuries to children during recent years is evidence that current prevention strategies are inadequate. Children should not use trampolines at home, and the sale of trampolines for private recreational use should be stopped.

Prilocaine-phenylephrine and bupivacaine-phenylephrine topical anesthetics compared with tetracaine-adrenaline-cocaine during repair of lacerations

The effectiveness of two new topical anesthetics that do not contain cocaine (prilocaine-phenylephrine and bupivacaine-phenylephrine) was compared with that of tetracaine-adrenaline-cocaine (TAC) during laceration repair in children. This study was a prospective, randomized, double-blind trial conducted in the emergency department of a large children's hospital. Participants were 180 children 1 year of age or older with a laceration 5 cm or less in length that required suturing. Pain felt during suturing was scored by suture technicians, research assistants, parents, and patients 5 years of age and older using a visual analogue scale (VAS). There was no statistical difference demonstrated between the effectiveness of prilocaine-phenylephrine and that of TAC for any of the observer groups. A statistically significant difference was seen among anesthetics when comparing VAS scores of research assistants (P = .002), suture technicians (P = .006), and parents (P = .03), but not when comparing VAS ratings of patients (P = .07). Based on Tukey's post hoc test, these statistically significant differences were between TAC and bupivacaine-phenylephrine. When power analyses were performed using alpha = 0.05 and beta = 0.20, it was possible to detect a difference of 1.3 VAS units for each rater group. In conclusion, this study demonstrated the effectiveness and safety of prilocaine-phenylephrine and bupivacaine-phenylephrine. Prilocaine-phenylephrine statistically outperformed bupivacaine-phenylephrine and offers an effective alternative to TAC during laceration repair in children.

New non-cocaine-containing topical anesthetics compared with tetracaine-adrenaline-cocaine during repair of lacerations

OBJECTIVE

To compare the effectiveness of three new topical anesthetics that do not contain cocaine (prilocaine-phenylephrine, tetracaine-phenylephrine [tetraphen], and tetracaine-lidocaine-phenylephrine) to that of tetracaine-adrenaline-cocaine (TAC) during laceration repair in children.

DESIGN

Prospective, randomized, double-blind clinical trial.

SETTING

The emergency department of an urban children's hospital.

PARTICIPANTS

Children 1 year of age or older with a laceration </= 5 cm in length that required suturing. Intervention. A total of 240 children were randomly assigned to one of four treatment groups.

OUTCOME MEASURES

Pain felt during suturing was scored by suture technicians, research assistants, parents, and patients >/= 5 years of age using a visual analogue scale (VAS). Suture technicians, research assistants, and parents also scored pain using a seven-point Likert scale. In addition, suture technicians completed an anesthetic effectiveness scale.

RESULTS

There was consistently no difference demonstrated between the effectiveness of tetraphen and that of TAC for each outcome measure of each observer group. A statistically significant difference was seen among anesthetics when comparing VAS and Likert scale scores of suture technicians and Likert scale scores of research assistants. Based on post hoc analyses, these statistically significant differences were between TAC and prilocaine-phenylephrine (suture technician VAS and Likert scale) and between TAC and tetracaine-lidocaine-phenyl-ephrine (suture technician Likert scale), but not between TAC and tetraphen. When power analyses were performed using alpha = 0.05 and beta = 0.20, it was possible to detect a difference of 1.2 VAS units for each of the observer groups. Based on anesthetic effectiveness scale scores, the three new topical preparations collectively performed significantly better on the face and scalp than on the extremities (relative risk = 1.83; 95% confidence interval 1.20 < relative risk < 2.79).

CONCLUSION

This study demonstrated the effectiveness and safety of three new non-cocaine-containing topical anesthetics. Consistently, there was no statistical difference demonstrated between the effectiveness of tetraphen and that of TAC for each outcome measure of each observer group. Tetraphen offers an effective alternative to TAC during laceration repair in children.

Deficits on self ordered tasks associated with hyperostosis frontalis interna

A 74 year old patient, EW, with dorsolateral frontal cortical compression due to hyperostosis frontalis interna, in the absence of the Morgagni or Stewart-Morel syndromes, is described. In addition to conventional neuropsychological measures EW was administered one nonspatial and two spatial self ordered working memory tasks, as well as a standard measure of fluid intelligence or g. She showed impaired performance on all three self ordered working memory tasks compared with a normal control group of 10 subjects matched for age, education, sex, and IQ. By contrast, her performance on the fluid intelligence test was comparable with that of the controls. It is concluded that the compression of dorsolateral frontal cortex accompanying hyperostosis frontalis interna may produce selective cognitive impairment.

Babywalker-related injuries continue despite warning labels and public education

OBJECTIVE

To describe the epidemiology of babywalker-related injuries to children treated in a pediatric emergency department despite current prevention efforts, and to investigate the beliefs of parents regarding babywalker use.

DESIGN

A descriptive study of a consecutive series of patients.

SETTING

The emergency department of a large, academic children's hospital.

PARTICIPANTS

Children treated for babywalker-related injuries during the 3-year period of March 1993 through February 1996.

RESULTS

There were 271 children treated for babywalker-related injuries. The mean age was 9.2 months, and 62% of patients were boys. Ninety-six percent of children were injured when they fell down stairs in their babywalker. The number of stairs that a child fell down was significantly associated with skull fracture and admission to the hospital, and a fall down more than 10 stairs had a relative risk (RR) of skull fracture = 3.28 (95% confidence interval, 1.35 < RR < 7.98). There were 159 children with contusions/abrasions (58.6%), 35 concussions/head injuries (12. 9%), 33 lacerations (12.2%), 26 skull fractures (9.6%), 9 epistaxis (3.3%), 4 nonskull fractures (1.5%), 4 avulsed teeth (1.5%), and 1 burn (0.4%). Three of the skull fractures were depressed, and three also had accompanying intracranial hemorrhage. Ten patients (3.7%) were admitted to the hospital, and all had skull fractures resulting from falls down stairs. Supervision was present in 78% of cases, including supervision by an adult in 69% of cases. Forty-five percent of families kept the walker, and 32% used the walker again for the study patient or another child after the injury episode. Fifty-nine percent of parents acknowledged that they were aware of the potential dangers of babywalkers before the injury event. Fifty-six percent of parents favored a national ban on the sale of walkers, and 20% were opposed.

CONCLUSION

Despite the currently used prevention strategies, including adult supervision, warning labels, care giver education programs, and stairway gates, serious injuries associated with babywalkers continue to occur to young children. The US Consumer Product Safety Commission should promulgate a rule, similar to the voluntary standard adopted in Canada, regarding design requirements for babywalkers that will prevent their passage through household doorways at the head of stairs. The manufacture and sale of mobile babywalkers that do not meet this new standard should be banned in the US. A recall or trade-in campaign should be conducted nationally to decrease the number of existing babywalkers.

How the Listeria monocytogenes ActA protein converts actin polymerization into a motile force

The ActA protein is an essential determinant of pathogenicity that is responsible for the actin-based motility of Listeria monocytogenes in mammalian cells and cell-free extracts. ActA appears to control at least four functions that collectively lead to actin-based motility: (1) initiation of actin polymerization, (2) polarization of ActA function, (3) transformation of actin polymerization into a motile force and (4) acceleration of movement mediated by the host protein profilin.

Test-retest reliability of a battery of sensory motor and physiological measures of aging

We report test-retest reliabilities for a battery of tests (vision, hearing, vibration sense, proprioception, forced expiratory volume, blood pressure, grip strength, and sway) shown previously to predict functional age. Fifty women aged 60 to 86 were retested on the battery after 3 months. All tests except proprioception and blood pressure had reliabilities between .70 and .94. We conclude that the battery provides reliable measures of sensory, motor, and physiological variables which may be used as markers of biological aging in psychological research.

Nontraumatic dental emergencies in a pediatric emergency department

The objectives of this study were to describe nontraumatic dental emergencies among children treated in a pediatric emergency department. The children studied received emergency treatment for a nontraumatic dental problem from December 1992 through November 1993. Among the 1,459 children treated for dental emergencies, 949 had a nontraumatic emergency (65%) and were enrolled in this study. Patients ranged in age from 1 month to 19 years, with a mean age of 6.9 years. Fifty-two percent of patients were male. The teeth were involved in 99% of cases. An abscess was present in 33% of patients; and among these patients, 26% also had a fistula. Pericoronitis was seen in 4% of patients, primary viral stomatitis in 1%, and an eruption hematoma in 0.5%. Caries is the etiology of the problem prompting the emergency department visit in 73% of patients, and baby bottle caries accounted for 18% of all cases of caries. Other etiologies included the late effects of trauma (8%), iatrogenic (7%), idiopathic (3%), and periodontal processes (2%). Tooth extraction was performed in 45% of patients. Findings of this large consecutive series provide a better understanding of this type of visit to the pediatric emergency department.

Evaluation of a model for improving emergency medical and trauma services for children in rural areas

STUDY OBJECTIVE

To evaluate the effectiveness of a rural emergency medical and trauma services project in increasing the knowledge and confidence of emergency care personnel in the management of acutely ill and injured children.

METHODS

This prospective, quasi-experimental study used an untreated control group design with pretest and posttest of pre-hospital and hospital-based emergency care personnel in two rural counties in central Ohio. Project evaluation compared 50 emergency care providers from the intervention county with 43 emergency care providers from the control county. Changes in knowledge and confidence of these personnel in the assessment and management of pediatric emergencies were compared.

RESULTS

Providers in the intervention county demonstrated a significantly greater increase in test scores regarding knowledge of pediatric emergencies than did providers in the control county (P = .001). Significantly greater improvement was also seen when comparisons of test scores were made for field (P = .02) and hospital (P = .03) emergency care personnel separately. Self-reports on a visual analog scale indicated that providers in the project intervention county had a significantly greater decrease in anxiety than did control subjects when presented a scenario of a child experiencing a respiratory arrest (P = .01). On the basis of scores from a five-point Likert scale, emergency personnel in the intervention county had a greater increase in confidence regarding management of the pediatric airway (P = .0003) and a greater increase in the belief that they had adequate pediatric training (P = .000001) after participating in the project than emergency personnel in the control county.

CONCLUSION

The rural pediatric emergency medical and trauma services project was effective in increasing the knowledge and confidence of emergency care personnel in the management of acutely ill and injured children. This project offers a model that can be replicated in other rural areas nationally.

Method to impact in vivo rabbit femoral cartilage with blows of quantifiable stress

The purpose of this study was to develop a technique by which a known stress could be applied uniformly across the femoral cartilage of a rabbit as a model for the development of post-traumatic arthritis. A system to impact the cartilage was designed that consisted of an apparatus to deliver a blow of quantifiable force, a method to apply the stress uniformly over the impact area, and a way to accurately measure the impact area. The knee joints of cadaveric New Zealand White rabbits were surgically exposed with the knee flexed so that the distal femoral articular surface was perpendicular to an impactor. With the knee fixed in position, a cup containing polymethylmethacrylate bone cement was applied to create an exact contour of the femoral surface, and the cement was allowed to cure. The form was then rested on the rabbit knee, and a drop tower released a weight of known mass from a known height onto an impactor (instrumented with strain gauges to measure the compressive force) that was attached to the cup. The area of the impacted surface was determined and, with the measured force, was used to calculate an accurate estimate of the impact stress. This method can be performed under sterile conditions, and therefore it is well suited for survival experiments in which the long-term effects of impact to cartilage will be studied.

High-dose cytarabine dose modification reduces the incidence of neurotoxicity in patients with renal insufficiency

PURPOSE

To determine the impact of high-dose cytarabine (ARA-C) (HDAC) dose modification, based on renal function, on the incidence of neurotoxicity (NT).

PATIENTS AND METHODS

We retrospectively analyzed the records of 256 patients treated with HDAC (> or = 2.0 g/m2 per dose) for acute myelogenous leukemia (AML) at the University of California, San Francisco (UCSF). From 1985 to 1994, a total of 358 cycles of HDAC were administered, using either a twice-daily schedule (n = 208) or a once-daily regimen (n = 48). In 1989, a dose-modification algorithm was initiated at our institution, which reduced ARA-C doses in the setting of renal insufficiency (RI). For patients with a serum creatinine (Cr) level of 1.5 to 1.9 mg/dL during treatment, or an increase in Cr during treatment (deltaCr) of 0.5 to 1.2 mg/dL, ARA-C was decreased to 1 g/m2 per dose. For patients with a Cr > or = 2.0 mg/dL or a deltaCr greater 1.2 mg/dL, the dose was reduced to 0.1 g/m2/d.

RESULTS

Overall, the incidence of NT was 16% (34 of 208) for patients treated with twice-daily HDAC and 0% (none of 48) for patients treated with daily HDAC (P = .003). NT occurred more often in patients treated on a twice-daily schedule with 3 g/m2 per dose compared with 2 g/m2 per dose (25% v 8%; P = .009). NT occurred in 55% of the twice-daily-treated patients with RI, compared with 7% of those with normal renal function (P = .00001). In patients with RI, NT occurred in none of 11 dose-modified cycles versus five of 11 (45%) total unmodified cycles (P = .01). None of 14 patients treated with once-daily HDAC given during RI developed NT, compared to 55% of patients (23 of 42) receiving twice-daily HDAC during RI (P = .009). By univariate analysis, NT was not associated with patient age or serum alkaline phosphatase, but NT was significantly increased in patients treated with twice-daily HDAC when the serum bilirubin was > or = 2.0 mg/dL compared with twice-daily HDAC given when the total bilirubin was less than 2.0 mg/dL (33% v 14%; P = .017). Multivariate analysis confirmed that RI was the most significant risk factor associated with the development of NT.

CONCLUSION

HDAC NT is strongly associated with RI. The risk of HDAC NT can be reduced by the following: (1) routinely reducing the ARA-C dose from 3 to 2 g/m2 per dose; (2) modifying the ARA-C dose based on daily Cr values; and (3) administering HDAC on a once-daily rather than twice-daily schedule.

Epidemiology of dental trauma treated in an urban pediatric emergency department

STUDY OBJECTIVE

To describe the epidemiology of traumatic dental injuries to children treated in an urban pediatric emergency department (ED).

DESIGN

A descriptive study of a consecutive series of patients.

SETTING

The ED of a large, academic children's hospital.

PARTICIPANTS

Children presenting to the ED with dental trauma from December 1992 to November 1993.

RESULTS

Of 1459 children treated for dental emergencies, 541 had dental trauma (37%) and were enrolled in this study. Patients ranged in age from five months to 18 years. Fifty-nine percent of patients were less than seven years of age, and 59% of patients were male. Falls caused 63% of injuries, followed by being struck (17%), and motor vehicle crashes (2%). Injuries to the soft tissues included lacerations (32%), swelling (8%), abrasions (7%), and contusions (6%). Injuries to hard dental structures included tooth fractures (33%), luxations (18%), concussions (12%), avulsions (8%), and jaw fractures (1%). Tooth luxation and concussion were more common among children less than seven years of age, and fractures to the tooth crown with dentin exposure (Ellis class II) were seen most often among children with permanent dentition (chi 2 = 41.4, P < 0.005). The central incisors were the teeth most frequently traumatized.

CONCLUSION

Findings of this large consecutive series provide a useful description of the epidemiology of this common type of pediatric trauma for pediatric emergency care providers.

Comparison of topical anesthetics with lidocaine infiltration during laceration repair in children

This study is a randomized, blinded trial that compares the effectiveness of a new topical anesthetic preparation of 2% mepivacaine and 1:100,000 norepinephrine (Mepivanor); a topical solution of 1% tetracaine, 1:4,000 adrenaline, and 4% cocaine (TAC); and 1% lidocaine infiltration during laceration repair in children. The study was conducted in the emergency department of a large academic children's hospital. Study participants were children 2 years of age or older with a laceration on the face or scalp, 5 cm or less in length, that required suturing. Patients were randomly assigned to receive Mepivanor topical solution, TAC topical solution, or lidocaine infiltration anesthesia prior to laceration repair. Seventy-one patients were enrolled in the study during a 2-month period. Outcome measures assessed pain perceptions using a Visual Analogue Scale (VAS) and a seven-point Likert scale. There was statistical power to detect differences of 1.2 to 1.7 units for the VAS outcome measures using alpha = 0.05 and beta = 0.20. There were no statistically significant (P > 0.05) differences between TAC and 1% lidocaine infiltration in providing effective anesthesia. Mepivanor was generally less effective in providing adequate anesthesia during laceration repair than TAC and lidocaine infiltration, with Tukey's post hoc test for ANOVA demonstrating statistically significant (P < 0.05) differences between Mepivanor and these agents for research assistant and suture technician VAS scores. Wound blanching was judged to be less with Mepivanor than with TAC, although this difference was not statistically significant. There were no adverse reactions, wound infections, or healing difficulties for any of the patients who received TAC or Mepivanor. It was concluded that non-cocaine-containing Mepivanor was generally less effective than TAC and lidocaine infiltration in providing adequate local anesthesia during laceration repair. TAC containing only 120 mg of cocaine (3 mL of 4% cocaine) was as effective as 1% lidocaine infiltration in providing local anesthesia during laceration repair. This will allow the amount of cocaine in TAC to be reduced, thereby decreasing costs and the likelihood of adverse reactions.