Musculoskeletal injuries in US Air Force Tactical Air Control Party trainees: an 11-year longitudinal retrospective cohort study and presentation of a musculoskeletal injury classification matrix

INTRODUCTION

Little is known of the epidemiology of musculoskeletal injuries (MSKIs) in US Air Force Special Warfare (AFSPECWAR) Tactical Air Control Party trainees. The purpose of this longitudinal retrospective cohort study was to (1) report the incidence and type of MSKI sustained by AFSPECWAR trainees during and up to 1 year following training, (2) identify factors associated with MSKI, and (3) develop and present the MSKI classification matrix used to identify and categorise injuries in this study.

METHODS

Trainees in the Tactical Air Control Party Apprentice Course between fiscal years 2010-2020 were included. Diagnosis codes were classified as MSKI or non-MSKI using a classification matrix. Incidence rates and incidence proportion for injury types and regions were calculated. Measures were compared for differences between those who did and did not sustain an MSKI during training. A Cox proportional hazards model was used to identify factors associated with MSKI.

RESULTS

Of the 3242 trainees, 1588 (49%) sustained an MSKI during training and the cohort sustained MSKIs at a rate of 16 MSKI per 100 person-months. Overuse/non-specific lower extremity injuries predominated. Differences were seen in some baseline measures between those who did and did not sustain an MSKI. Factors retained in the final Cox regression model were age, 1.5-mile run times and prior MSKI.

CONCLUSION

Slower run times and higher age were associated with an increased likelihood of MSKI. Prior MSKI was the strongest predictor of MSKI during training. Trainees sustained MSKIs at a higher rate than graduates in their first year in the career field. The MSKI matrix was effective in identifying and categorising MSKI over a prolonged (12-year) surveillance period and could be useful for future injury surveillance efforts in the military or civilian settings. Findings from this study could inform future injury mitigation efforts in military training environments.

Appendiceal intussusception presenting as a caecal mass

INTRODUCTION

The differential diagnosis of caecal mass is broad and the inclusion of appendiceal pathologies is an important element.

CASE REPORT

We report a 37-year-old woman with recurrent right iliac fossa pain. Computed tomography scan revealed a caecal mass suggesting complete inversion or intussusception of the appendix, which was confirmed by pathologic microscopic examination. This case report discusses appendiceal intussusception with emphasis on diagnosis and treatment options.

DISCUSSION

Appendiceal intussusception is a rare entity and the complete type typically presents as a polypoid lesion located at the appendiceal orifice in the caecum. It is imperative to include this entity in the differential diagnosis of caecal mass, especially during colonoscopy, as the removal of this polypoid lesion can result in a devastating caecal perforation or haemorrhage.

Cardiac biomarkers of disordered eating as a function of diagnostic subtypes

OBJECTIVE

The purpose of this study was to identify cardiac biomarkers of disordered eating as a function of diagnostic subtype as assessed via self-report inventory.

METHOD

Mean heart rate (HR), systolic and diastolic blood pressure, mean R wave amplitude (mV), mean T wave amplitude (mV), QTc interval (sec), Tpeak-Tend interval prolongation (sec), QTc interval prolongation (sec), QRS prolongation (sec), and spectral indicators of cardiac dysfunction (LF/HF spectral ratio, HF spectral power) were assessed via electrocardiography among women with no eating disorder symptoms (n = 32), subclinical eating disorder symptoms (n = 92), anorexia nervosa (n = 7), bulimia nervosa (n = 89), binge eating disorder (BED: n = 20), and other specified feeding and eating disorders (OSFED: n = 19).

RESULTS

MANOVA results showed statistically significant group differences. Follow-up tests revealed significantly decreased mean R wave amplitude among participants with self-indicated clinical (bulimia nervosa, binge eating disorder) and subclinical forms of disordered eating compared to asymptomatic controls.

DISCUSSION

Results suggest decreased mean R wave amplitude is a promising cardiac biomarker of disordered eating.

Tackling The Challenge Of Opioid Use And Abuse And Treatment Of Chronic Pain Management

Introduction/Objective

Deaths from opioid overdose increased 12% from 2016 to 2017. This major economic burden cost roughly $78.5 billion in the US. This steep increase in drug overdose deaths can be attributed to increased synthetic opioid abuse. To better understand and reduce opioid abuse amongst patients at Henry Ford Health System, Detroit MI, we sought to collaborate with physicians to manage prescribing, interpret test results, improve patient care, and deliver more value.

Primary Aim: To create a directed pain panel for ordering and interpreting pain management drugs to help providers to better manage patients and to assess compliance from test ordering history to serve patients safely and effectively.

Secondary Aim: To streamline the process of prescribing pain medications and to create a patient centered approach to treat chronic non-cancer patients who actually need opioids, to minimize the risk of abuse, diversion and addiction among patients.

Methods

Plan Do Check Act (PDCA) cycles of process improvement were used to achieve our two aims. In the first cycle, a drug screen-ordering guide was developed to facilitate screening (qualitative) and confirmation (quantitative) ordering practices. As part of this, providers prescribing for chronic pain patients were advised to use drugs of abuse panel rather than our emergency drug screen. In the second cycle, a directed pain panel (DPP) was introduced with reflex to confirmation testing. The DPP led to discovery of unexpected fentanyl positives, which were further investigated.

Results

A survey was conducted to investigate provider-ordering practices, which showed that use of the new drugs of abuse panel rose from 57% to 77%. The DPP was accepted by ~60% of physicians and was frequently reordered in follow-up. Analysis of unexpected fentanyl positivity revealed 30% true positivity, thus identifying unknown patient use. A future PDCA cycle is focused on developing, implementing, and measuring the customer value of a laboratory generated interpretive opioid results report at 5 similar organizations with a goal to assist with test selection and simplify provider interpretation of results.

Conclusion

A future PDCA cycle is focused on developing, implementing, and measuring the customer value of a laboratory generated interpretive opioid results report at 5 similar organizations with a goal to assist with test selection and simplify provider interpretation of results.

BedMachine v3: Complete Bed Topography and Ocean Bathymetry Mapping of Greenland From Multibeam Echo Sounding Combined With Mass Conservation

Greenland's bed topography is a primary control on ice flow, grounding line migration, calving dynamics, and subglacial drainage. Moreover, fjord bathymetry regulates the penetration of warm Atlantic water (AW) that rapidly melts and undercuts Greenland's marine-terminating glaciers. Here we present a new compilation of Greenland bed topography that assimilates seafloor bathymetry and ice thickness data through a mass conservation approach. A new 150 m horizontal resolution bed topography/bathymetric map of Greenland is constructed with seamless transitions at the ice/ocean interface, yielding major improvements over previous data sets, particularly in the marine-terminating sectors of northwest and southeast Greenland. Our map reveals that the total sea level potential of the Greenland ice sheet is 7.42 ± 0.05 m, which is 7 cm greater than previous estimates. Furthermore, it explains recent calving front response of numerous outlet glaciers and reveals new pathways by which AW can access glaciers with marine-based basins, thereby highlighting sectors of Greenland that are most vulnerable to future oceanic forcing.

Surgery alters parameters of vitamin D status and other laboratory results

Fracture liaison services often perform laboratory testing, but these results may be altered by surgery. In 40 hip arthroplasty patients, many laboratory parameters of bone health relevance were reduced by 8-22% on the first post-operative day. Laboratory results obtained in the immediate post-surgery interval do not reliably ascertain baseline status.

INTRODUCTION

As secondary causes of osteoporosis are common, fracture liaison services often perform laboratory testing in the immediate post-fracture interval. We hypothesized that laboratory results obtained shortly after surgery may not accurately ascertain baseline status. If true, such alterations might confound subsequent fracture prevention efforts.

METHODS

Patients undergoing elective total hip arthroplasty were studied as a surrogate for hip fracture patients. Blood and urine were obtained 2 weeks before surgery, before anesthetic induction, on post-operative day one, and 6 weeks after surgery. Serum total and free 25-hydroxyvitamin D (25(OH)D), vitamin D-binding protein (DBP), calcium, creatinine, albumin (Alb), alkaline phosphatase (ALP), plasma hemoglobin (Hgb) and urinary DBP/creatinine ratio (UDBP/Cr) were measured.

RESULTS

Forty volunteers (28 women; 12 men) with mean age of 65.7 [8.7] years were studied. Laboratory results were stable from 2 weeks before to the day of surgery. On the first day after surgery, total 25(OH)D, DBP, calcium, creatinine, ALP, and Alb declined 8-22% (p < 0.0001); free 25(OH)D and Hgb declined by 8 and 15% (p < 0.01), respectively; and UDBP/Cr increased 32% (p < 0.01). Using a 25(OH)D <30 ng/mL threshold, vitamin D inadequacy prevalence increased from 38% before surgery to 68% the day after (p < 0.001). All laboratory values returned to baseline at 6 weeks after surgery.

CONCLUSIONS

Laboratory values are reduced immediately following elective total hip arthroplasty. Testing at that time does not accurately ascertain baseline status and may lead to elevated estimates of vitamin D inadequacy, incorrect interventions, and misallocation of healthcare resources.

Late extrusion of a temporomandibular joint prosthesis masquerading as a sebaceous cyst

Complications of temporomandibular joint prostheses are not uncommon and have been well documented. We report a very late and rare complication following silastic TMJ replacement, believed to be the first implant extrusion through healthy skin. We are reminded that these implants can still cause problems to patients many years after initial surgery.

269 THE USE OF A NEW EXTENDER FOR STORING FRESH BOVINE SEMEN FOR LONG PERIODS

Processing bovine semen in fresh long life extender for use over 3 to 4 days after collection is a widely used technique in New Zealand (Shannon and Vishwanath 1995 Anim. Reprod. Sci. 39, 1-10). Advantages include greater use of valuable sires, transport without liquid nitrogen, and the possibility of more efficient use of sexed sorted semen. The new extender (Ext. A) also has the advantage of containing no egg yolk. This study compares this new long-life extender (Ext. A) with an existing product (Ext. B) and frozen/thawed semen. Semen from 12 different bulls was diluted to a concentration of 8 × 106 mL-1 and gradually cooled to 16°C. All samples were held at ambient temperature in the dark and motility was evaluated over a storage period of 4 days comparing the extenders. In this part of the trial Ext. A maintained motility better than Ext. B (P = 0.001) during the 4-day storage period (24 h: 90 v. 70%; 96 h: 85 v. 50%). The second part of the trial compared the conception rates (CR) in cows from the use of fresh long-term-extended semen and frozen/thawed semen. On 19 farms, 8546 cows were inseminated with fresh semen stored for 1 to 3 days and 7280 cows were inseminated with frozen semen. The overall CR at 7 to 8 weeks for the 19 farms was 73.7%. On 18 farms within the same farming group, 8498 cows received frozen semen and the CR was 71.1%. Pregnancy results were 2.6% (P = 0.001) higher CR at scanning in herds where fresh semen was used compared with the farms where only frozen/thawed semen was used (73.7 v. 71.1%). In the third part of the trial, semen from 4 different bulls were extended to 1 × 106 mL-1 in Ext. A and held at ambient temperature for 6 days prior to use for IVF. Our lab standard frozen/thawed bull semen was used as a control. Table 1 shows that semen held at ambient temperature in Ext. A for 6 days produced a similar percentage of transferable quality embryos to our IVP control frozen/thawed semen (26.9 v. 25.7%). We conclude that preserved bovine semen in fresh long-life extender for several days offers some advantages in AI and IVP programs compared with frozen semen. Table 1.Fresh semen extender (Ext.A) compared with frozen semen in IVP We appreciate the assistance of Liberty Genetics Ltd.

Muscarinic type 1 receptors mediate part of nitric oxide’s vagal facilitatory effect in the isolated innervated rat right atrium

We investigated whether vagal cardiac cholinergic facilitation by nitric oxide (NO) is mediated by cardiac muscarinic receptor subtypes in the vagally innervated rat right atrium in vitro. Experiments were carried out in the presence of atenolol (4 microM). The right vagus was stimulated at 4, 8, 16, 32 Hz; pulse duration 1 ms at 20 V for 20s; vagal postganglionic activation was achieved using nicotine (0.1, 0.3, 0.5, 1mM) and the effect on cardiac interval (ms) assessed. Pirenzepine (1 microM), a M1 antagonist, attenuated vagally induced increase in cardiac interval. L-Arginine (0.34 mM) superfused with pirenzepine failed to reverse this attenuation, however, L-arginine applied alone reversed the reduction vagal cardiac slowing. Similarly, sodium nitroprusside (10 microM) applied alone, and not together with pirenzepine, was able to reverse the attenuation of vagal effects caused by pirenzepine. Synthetic MT7 (1 nM) toxin, a selective M1 antagonist confirmed these results. M3 antagonism using para-fluorohexahydrosiladifenidol (p-F-HHSiD) (300 nM) and M4 antagonism with PD 102807 (200 nM) did not affect the vagally induced increase in cardiac interval. Nicotine induced increase in cardiac interval was not altered by pirenzepine. These results show that antagonism of M1 receptors on cardiac vagal preganglionic fibres reduces vagal efficacy which can be recovered by either a nitric oxide synthase substrate or a NO donor.

The safety of single-physician procedural sedation in the emergency department

BACKGROUND

Previous research has shown the safety of procedural sedation in the emergency department in university settings involving multiple emergency physicians.

OBJECTIVE

To examine sedation in the emergency department conducted by a single emergency physician with monitoring by the emergency nurse.

METHODS

The Procedural Sedation in the Community Emergency Department Registry is a prospective observational database of procedural sedation cases directed by the emergency physicians. Among other parameters, the registry tracts whether emergency physicians or emergency nurses monitored patient sedation. The incidence of complications and outcomes were compared between these two monitoring groups.

RESULTS

1028 procedural sedations were performed on 977 patients at 14 sites. In 885 (86.1%) cases the emergency physician directed the sedation, and performed the procedure with monitoring by the emergency nurse. Complications occurred in 42 (4.1%) patients, 35 (4.0%) EN monitored patients and 6 (4.2%) EP monitored patients (p>0.7). Procedures were successful in 863 (97.5%) cases monitored by emergency nurses and in 140 (97.9%) patients monitored by emergency physicians (p>0.7).

CONCLUSION

Procedural sedation in the emergency department performed by a single emergency physician is safe and effective.

Vasoactive intestinal polypeptide receptor antagonism enhances the vagally induced increase in cardiac interval of the rat atrium in vitro

The effect of vasoactive intestinal polypeptide (VIP) receptor antagonism on preganglionic vagal electrical stimulation and on vagal postganglionic activation using nicotine and 1,1-dimethyl-4-phenylpiperazinium iodide on cardiac interval was evaluated in the isolated innervated rat right atrium. The vagus was stimulated at 4, 8, 16 and 32 Hz, pulse duration 1 ms, 20 V, for 30 s. All experiments were carried out in the presence of atenolol (4 microM). Vagal stimulation caused a frequency-dependent increase in cardiac interval which was amplified significantly at each frequency, except at 32 Hz, following application of the VIP receptor antagonist VIP(6-28) at 2 nM in 15 rats. Application of the ganglionic antagonist hexmethonium (28 microM, n = 7 rats) prior to 2 nM VIP(6-28) abolished this effect. Increasing the concentration of VIP(6-28) 10-fold to 20 nM did not result in a greater increase in cardiac interval than that obtained at 2 nM. Nicotine (0.1, 0.3, 0.5, 1.0 and 2.0 mM) increased cardiac interval by direct activation of postganglionic vagal fibres, but 2 nM VIP(6-28) did not affect the nicotine concentration response (n = 6 rats). 1,1-Dimethyl-4-phenylpiperazinium iodide (25, 50, 100 and 200 microM; n = 6 rats) was also used to induce an increase in cardiac interval; again it was not significantly altered by 2 nM VIP(6-28). Therefore, VIP receptor antagonism enhances the magnitude of vagally induced cardiac slowing, probably via an action at the preganglionic-postganglionic synapse.

An Investigation into the Presence of a Vagal Tachycardia and the Effect of Vasoactive Intestinal Polypeptide on Rat Heart Rate in vitro

The presence of the vagal tachycardia and the effect of vasoactive intestinal polypeptide in the isolated innervated rat atrium were investigated. The right vagus, or cardiac branch, were stimulated at 4, 8, 16 and 32 Hz, pulse duration 1 ms, 20 V, 30 s before atropine and for 1 min after atropine (3 micromol/l), experiments were carried out in the presence of atenolol (4 micromol/l). No significant vagal tachycardia was observed in the presence of atropine, the greatest increase in heart rate was at 16 Hz which was 3+/-1 beats/min (n = 12 rats) (p = 0.052). Baseline heart rates for the control, 226+/-11 beats/min (n = 12 rats) and atropine experiments, 210+/-8 beats/min (n = 12 rats), were not significantly different (p = 0.24). VIP (0.06, 0.12, 0.24 micromol/l) caused a maximum increase of 27+/-13 beats/min (n = 5 rats) after 6 micromol/l VIP which was not significant, two higher concentrations of VIP failed to increase heart rate further. These results show that the vagal tachycardia is not present and that VIP does not cause a significant tachycardia in the rat.

Evidence for synergistic modulation of early information processing by nicotinic and muscarinic receptors in humans

Impairments in early information processing are a hallmark feature of diverse neuropsychiatric disorders including schizophrenia and Alzheimer's disease (AD). Several lines of evidence implicate a dysfunction of the cholinergic system in these disorders, particularly in AD where there is known degeneration in major cholinergic pathways. Inspection time (IT), a measure of early visual information processing speed, has been shown to be sensitive to cholinergic manipulation. The current study employed the IT task to (1) examine the independent roles of nicotinic and muscarinic receptors in modulating information processing and (2) investigate the interaction of nicotinic and muscarinic receptor systems in modulating information processing. Twelve healthy participants completed a randomized, double-blind, placebo-controlled study under four drug conditions; (1) placebo, (2) mecamylamine (15 mg; oral), (3) scopolamine (0.4 mg, s.c.), (4) mecamylamine (15 mg) + scopolamine (0.4 mg). IT measures were examined at baseline and 2.5 h post drug administration. Selective blockade of nicotinic receptors with mecamylamine did not significantly impair IT, whereas selective blockade of muscarinic receptors with scopolamine produced a significant but small impairment in IT. Combined blockade of both receptor types with scopolamine and mecamylamine produced a large impairment in IT performance. The results indicate that both nicotinic and muscarinic receptors are involved in modulating IT, and that the two systems may function synergistically to modulate early visual information processing. These findings suggest that functional abnormalities in both nicotinic and muscarinic systems may underlie deficits in early visual information processing seen in disorders such as Alzheimer's disease and schizophrenia.

Autosomal dominant canine malignant hyperthermia is caused by a mutation in the gene encoding the skeletal muscle calcium release channel (RYR1)

BACKGROUND

Malignant hyperthermia (MH) is an inherited disorder of skeletal muscle characterized by hypercarbia, rhabdomyolysis, generalized skeletal muscle contracture, cardiac dysrhythmia, and renal failure, that develops on exposure to succinylcholine or volatile anesthetic agents. All swine and up to 50% of human MH events are thought to be associated with mutations in the calcium release channel of the sarcoplasmic reticulum, also known as the ryanodine receptor (RYR1). Events resembling MH have been reported in other species, but none have undergone genetic investigation to date.

METHODS

To determine the molecular basis of canine MH, a breeding colony was established with a male, mixed-breed, MH-susceptible (MHS) dog that survived an in vivo halothane-succinylcholine challenge. He was mated to three unaffected females to produce four litters and back-crossed to an affected daughter to produce one litter. One of his MHS sons was mated to an unaffected female to produce an additional litter. Forty-seven dogs were phenotyped with an in vitro contracture test and diagnosed as MHS or MH normal based on the North American in vitro contracture test protocol. Nine microsatellite markers in the vicinity of RYR1 on canine chromosome 1 (CFA01) were tested for linkage to the MHS phenotype. Mutational analysis in two MHS and two MH-normal dogs was performed with direct sequencing of polymerase chain reaction products and of cloned fragments that represent frequently mutated human RYR1 regions. A restriction fragment length polymorphism was chosen to detect the candidate mutation in the pedigree at large.

RESULTS

Pedigree inspection revealed that MHS in this colony is transmitted as an autosomal dominant trait. FH2294, the marker closest to RYR1, is linked to MHS at a theta = 0.03 with a LOD score of 9.24. A T1640C mutation gives rise to an alanine for valine substitution of amino acid 547 in the RYR1 protein, generating a maximum LOD score of 12.29 at theta = 0.00. All dogs diagnosed as MHS by in vitro contracture test were heterozygous for the mutation, and all MH-normal dogs were homozygous for the T1640 allele.

CONCLUSIONS

These results indicate that autosomal dominant canine MH is caused by a mutation in the gene encoding the skeletal muscle calcium release channel and that the MHS trait in this pedigree of mixed-breed dogs is in perfect cosegregation with the RYR1 V547A mutation.

Identification of the Arg1086His mutation in the alpha subunit of the voltage-dependent calcium channel (CACNA1S) in a North American family with malignant hyperthermia

Individuals from a large North American population were screened for the presence of the mutation in the alpha1 subunit of the voltage-dependent calcium channel (CACNA1S) that has recently been associated with malignant hyperthermia (MH). This Arg1086His mutation was screened for in 154 MH normal (MHN) individuals and 112 MH susceptible (MHS) individuals, who were diagnosed by the North American protocol of the in vitro contracture test. PCR and restriction enzyme analysis was used to test for the mutation. The Arg1086His mutation in the CACNA1S was not found in any of the MHN individuals. In contrast, two related individuals (grandfather and grandson, father and son of the MH proband) among the MHS group exhibited this mutation. However, a third MHS individual in the same family (granddaughter, cousin of the grandson) did not exhibit this mutation. These results indicate that this mutation may be associated with MH in this family. Genetic alterations in the CACNA1S associated with MH are present in approximately 1% of this North American MHS population.

The 'price' of Olympic Gold

In 1981 the Commonwealth Government established the Australian Institute of Sport (AIS). The Australian Sports Commission (ASC) which administers the AIS has 2 objectives: (1) excellence in sports performances; and (2) increased participation in sports and sports activities. State-based institutes of sport have also been established with the same or very similar objectives. Federal policy directs the bulk of the ASC budget to elite athlete programs. A smaller proportion goes towards community participation. The official reason is based on the notion of the 'trickle-down' or 'demonstration' effect. That is, a flow-on of benefits to the broader community in the form of increased participation as a direct result of elite sports success. The aims of this study were to determine the (1) spending pattern to elite sports programs for the 5 Olympics 1976/77 to 1995/96, (2) evidence for the two ASC objectives having been met, and (3) expected medal tally at the 2000 Olympic Games. Results show funding (in 1998 dollars), has accelerated from about $1.2 million (1976/77) to $106 million in (1997/98), particularly since the Games were awarded to Sydney. The total amount spent on elite athletes was $0.918 billion. In the period 1980-96 Australia won 25 gold and 115 total Olympic medals. This equates to approximately $37 million per gold and $8 million per medal in general. There was a significant linear relationship between money spent and total medals won. This was also found when all medal types were analysed independently. The predicted medal tally in 2000 (based on the cost per medal and the expenditure towards Sydney) indicates the medal count will be about 14+/-1 gold, 15+/-2 silver and 33+/-4 bronze. Based on our nation's record of international sporting achievement, there is little doubt we have fulfilled the ASC's first objective. Current data on physical activity patterns of Australians suggest the second objective has not been met. Focusing attention on and achieving the first objective does not appear to have any bearing on the second objective. It is time to revisit the notion that elite sporting success leads to greater mass participation as a result of the so-called 'trickle-down' effect.

Stroke-specific FIM models in an urban population

Data from the Functional Independence Measure (FIM) are important outcome measures in the stroke population undergoing rehabilitation. The FIM consists of 18 scales scored from 1 to 7; higher numbers mean greater ability. Several different scores can be obtained from the FIM: a total score (sum of all the scales), individual scale scores, and a physical and cognitive score (a two-dimensional interpretation). Research has shown that FIM data can have multidimensional components. That implies different groupings of scales may exist and with this the possibility of developing more sophisticated and robust measures within stroke populations. This study examined the multidimensional aspects of FIM using an urban sample of ischemic and hemorrhagic stroke patients. We found a three-dimensional FIM solution for both stroke groups that included self-care, cognitive function, and toileting as the major grouping of scales. These findings confirm a multidimensional nature of FIM scores and show a condition-specific pattern of FIM scores in stroke patients. This knowledge will help nurses, clinicians, and researchers develop more sensitive ways of recording care outcomes; improved prediction of stroke outcomes may also emerge from this knowledge.

Structure and alternative splicing of the gene encoding the human beta1 subunit of voltage dependent calcium channels

The structure of the gene encoding the human brain beta1 subunit of voltage dependent calcium channels (CACNB1) was determined by comparison of its genomic sequence with beta1 cDNA sequence. CACNB1 is distributed over 25 kb and contains 13 exons. Alternative splicing of CACNB1 RNA occurs within the central domain at exon 7, and the 3' domain at exon 13, producing the variably expressed beta1a, beta1b and beta1c isoforms. Exon/intron boundaries and exon lengths are conserved for the nine exons shared by the beta1 and related brain beta3 and beta4 genes.

The integrated exposure uptake biokinetic model for lead in children: independent validation and verification

The U.S. Environmental Protection Agency employs a model, the integrated exposure biokinetic (IEUBK) model for lead in children, for the assessment of risks to children posed by environmental lead at hazardous waste sites. This paper describes results of an effort to verify the consistency of the documentation with the computer model and to test the computer code using a group that is independent from those involved in the model development. This review concluded that the IEUBK model correctly calculates the equations specified in the IEUBK model theory documentation. However, several issues were identified on model documentation, model performance, and the C++ programming language code (i.e., IEUBK model source code) documentation. These issues affect the ability of an independent reviewer to understand the workings of the IEUBK model but not the model's reliability. As a result of these findings, recommendations have been provided for updating documentation to the model as well as associated adjustments to the model documentation.

Integrated exposure uptake biokinetic model for lead in children: empirical comparisons with epidemiologic data

The concept of model validation is evolving in the scientific community. This paper addresses the comparison of observed and predicted estimates as one component of model validation as applied to the integrated exposure uptake biokinetic (IEUBK) model for lead in children. The IEUBK model is an exposure (dose)-response model that uses children's environmental lead exposures to estimate risk of elevated blood lead (typically > 10 micrograms/dl) through estimation of lead body burdens in a mass balance framework. We used residence-specific environmental lead measurements from three epidemiologic datasets as inputs for the IEUBK model to predict blood lead levels, and compared these predictions with blood lead levels of children living at these residences. When the IEUBK modeling focused on children with representative exposure measurements, that is, children who spent the bulk of their time near the locations sampled, there was reasonably close agreement between observed and predicted blood lead distributions in the three studies considered. Geometric mean observed and predicted blood lead levels were within 0.7 microgram/dl, and proportions of study populations expected to be above 10 micrograms/dl were within 4% of those observed.

The anesthetic myopathies and malignant hyperthermias

Fatal destruction of skeletal muscle coincident with exposure to specific drugs used during anethesia has been recognized as a potentially heritable disorder for more than 30 years. Variable expressivity and incomplete penetrance of the clinical malignant hyperthermia phenotype, together with inherent drawbacks of the in-vitro contracture test confounded efforts to discover the underlying pathogenesis until the application of molecular genetic techniques. On the basis of linkage analysis and mapping of positional candidate genes, mutant alleles at loci on chromosomes 1q, (dihydropyridine-sensitive L-type calcium channel-A1S); 3q, 5p, 7q (dihydropyridine-sensitive L-type calcium channel-LA2), and 19q (ryanodine receptor) are now believed to account for up to 50% of human malignant hyperthermia susceptibility. Although inconsistent genotype-phenotype correlations and doubts regarding the causality of each mutant allele persist, the definition of malignant hyperthermia and relevance of molecular genetic data to the problems of family counseling, population screening, and improved resolution of the malignant hyperthermia phenotype must now be appraised in view of significant locus and allelic genetic heterogeneity.

Renal transplantation in a patient with methylmalonic acidaemia

Renal insufficiency is frequently reported in mutase-deficient methylmalonic acidaemia. We present a case report of a patient with mut- methylmalonic acidaemia who developed chronic tubulointerstitial nephropathy during adolescence. At 24 years of age, she developed end-stage renal failure and underwent renal transplantation. Both plasma and urine methylmalonic acid levels decreased significantly with improved renal function following transplantation. Complications included cyclosporin toxicity and development of diabetes. Renal, metabolic, and clinical status remained improved at 3 years after the kidney transplant.

Do IDSs really benefit from affiliating with managed care plans?

Integrated delivery systems (IDSs) affiliate with HMOs primarily to gain access to patients enrolled in managed care plans. Outright ownership of an HMO offers an IDS additional advantages, including opportunities to create a more seamless care process, improve patient outcomes, draw on the HMOs' experience in reducing costs, and administer health management and delivery at a significantly lower cost than the industry standard. The current trend toward IDS ownership of HMOs suggests that the line between providers and payers is blurring. Some states have encouraged this trend by enacting legislation that allows IDSs to act as insurers. Recent data indicate that IDSs with HMO components tend to be more vertically integrated than those without such components. These data suggest that close alignment with an HMO may be a key element in the effort to achieve vertical integration.

Hospital-based patient information services: a model for collaboration

Crouse Hospital in Syracuse, New York, is a 612-bed, not-for-profit teaching hospital with 2,500 employees. A close examination of operations at Crouse facilitated the development of a patient education task force that used a comprehensive, multidisciplinary approach to meet the educational needs of both patients and clinicians. The collaborative process involved all hospital departments. Within eighteen months, patient requests for information rose from 3% to 30% of total requests made at the hospital. Requests were made directly to the library or through a member of the health care team. Hospital staff members were surveyed about information needs and availability, and a library work plan was devised, setting standards of service for a multimedia approach. Work redesign improved the library staff's ability to integrate patient education into daily operations. Cost savings were achieved through the elimination of duplicated resources and services throughout the hospital. The management model developed at Crouse was the result of a needs assessment and a multidisciplinary, collaborative process. The model emphasizes communication links among disciplines rather than physical locations. The Crouse experience validates the development of hospital-based consumer health information services.

Polysome-associated mRNAs are substrates for the nonsense-mediated mRNA decay pathway in Saccharomyces cerevisiae

In eukaryotic cells, premature termination of translation at nonsense codons has been implicated as the cause of a variety of posttranscriptional events, including rapid mRNA decay in the cytoplasm or the nucleus, altered splice site selection, and exon skipping. In the yeast Saccharomyces cerevisiae, nonsense codons promote accelerated mRNA decay, and we sought to determine the cellular location in which this degradation occurs. In this report, we demonstrate that six different mRNAs, including nonsense-containing transcripts of the LEU2, HIS4, PGK1, and CYH2 genes, and two wild-type mRNAs (the MAT(alpha)1 and CYH2 mRNAs), were stabilized when the translation elongation inhibitor cycloheximide was added to cellular growth media. Subsequent removal of cycloheximide resulted in resumption of translation and degradation of wild-type and nonsense-containing mRNAs. A significant fraction of the CYH2 pre-mRNA that accumulated in the presence of cycloheximide was associated with polysomes, but disappeared from that fraction when decay resumed in the absence of the drug. Moreover, the abundance of the spliced and unspliced forms of the untranslated U3 snRNA was shown to be unaffected in strains harboring mutations that stabilize nonsense-containing mRNAs. Taken together, these observations indicate that nonsense-containing mRNAs in yeast are degraded within the polysome compartment of the cell.

Genotype-phenotype correlations of DHP receptor alpha 1-subunit gene mutations causing hypokalemic periodic paralysis

Hypokalemic periodic paralysis (hypoKPP) is an autosomal dominant or sporadic disorder characterized by periodic, reversible attacks of muscle weakness. Mutations in the skeletal muscle dihydropyridine receptor alpha 1-subunit that functions as a calcium channel (CACNL1A3) cause hypoKPP. We studied a group of 45 hypoKPP probands and demonstrated mutations in 30 of them. When compared with patients in whom CACNL1A3 mutations were not identified, those with mutations had an earlier age of onset and more often had a family history of hypoKPP. To date, three mutations have been identified. The R1239G mutation has only been found in one family. Of the 30 probands with recognized mutations, R528H accounted for 43% and R1239H was seen in 53%. Age of onset and potassium levels during attacks were lower in patients with the R1239H mutation than those with R528H. Cardiac dysrhythmias co-segregated with hypoKPP in one small kindred with the R528H mutation. No mutations were identified in exons of the gene encoding the S4 segments of domains one and three or the cytoplasmic loop between domains two and three. In addition to the 45 hypoKPP probands, an additional 11 probands with clinical variants of hypoKPP (three thyrotoxic hypoKPP and eight Andersen syndrome patients) were examined for CACNL1A3 mutations and none were found.

Brief report: two case studies using virtual reality as a learning tool for autistic children

The children complied with most requests. Some of our teaching goals were limited by technology or space while others were limited by the difficulty of presenting a task to the children in a way that was understandable within their environment. However, the opportunity to introduce this technology to children was an important first step in exploring the potential VR offers to understanding the perceptual processes involved in autism. Our results indicate that the will accept a VR helmet and wear it, identify familiar objects and qualities of these objects in their environment while using the helmet, and locate and move toward objects in their environment while wearing the helmet. More research is necessary to verify the potential in this area, especially to discover if learning experiences through VR generalize to other environments, but it appears virtual reality may provide a useful tool for furthering our understanding of autism and guiding efforts at treatment and intervention.

Prevalence of HIV infection among pregnant women in Newfoundland

OBJECTIVE

To determine the prevalence of HIV infection among pregnant women in Newfoundland.

DESIGN

Anonymous unlinked seroprevalence study.

SETTING

Newfoundland.

PATIENTS

A total of 14911 women receiving prenatal care or undergoing an abortion, representing nearly all pregnancies in Newfoundland from Nov. 1, 1991, to Oct. 31, 1993.

OUTCOME MEASURES

HIV antibody status, as determined by enzyme immunoassay of leftover serum samples (initially obtained for routine screening) and confirmation of reactive samples by the Western blot technique, health region of residence, and age group.

RESULTS

Of the 14911 serum samples 13 were positive for HIV, for an overall crude prevalence rate of 1 per 1147 or 8.7 per 10000 pregnant women (95% confidence interval [CI] 4.7 to 14.9). Seven of the positive samples were from women residing in the Eastern Health Region of the province, for a crude prevalence rate of 1 per 376 or 26.6 per 10000 pregnant women (95% CI 10.7 to 54.8) for that region. All women found to be HIV positive were 15 to 29 years of age, the peak prevalence (20.8 per 10000 pregnant women [95% CI 9.5 to 39.4]) was observed among those 20 to 24 years.

CONCLUSIONS

The overall prevalence rate of 8.7 per 10 000 pregnant women in Newfoundland is the highest provincial rate recorded among those from similar studies in Canada. Although it may be concluded that there are an estimated 125 HIV-positive women of childbearing age in Newfoundland (95% CI 67 to 213), the age-adjusted estimate is 84 (95% CI 36 to 131). This study provides an independent confirmation of an outbreak of HIV infection among women in the Eastern Health Region of the province.

The structure of the gene encoding the human skeletal muscle alpha 1 subunit of the dihydropyridine-sensitive L-type calcium channel (CACNL1A3)

The structure of the gene encoding the human skeletal muscle alpha 1 subunit (CACNL1A3) of the dihydropyridine-sensitive voltage-dependent calcium channel was determined by isolation of overlapping genomic DNA clones from human cosmid, phage, and P1 libraries. Genomic fragments containing exons were subcloned, and the sequences of the exons and flanking introns were defined. Knowledge of the genomic structure of the CACNL1A3 gene, which spans 90 kb and consists of 44 exons, will facilitate the search for additional mutations in CACNL1A3 that cause neuromuscular disease.

Self-measurement of blood pressure: issues related to the training of patients. Canadian Coalition for High Blood Pressure Prevention and Control

For effective self-measurement of blood pressure, patients need to be able to obtain accurate and reproducible measurements. Criteria for measuring blood pressure have been well developed in research studies, and through the use of standardized training programs it has been established that nonmedically trained individuals can obtain valid measurements. These recommendations for blood pressure measurement were adapted to the self-measurement situation. Either manual sphygmomanometers or automated electronic devices can be used effectively. Although automated devices may be easier to use, the health care practitioner should ensure that any such device has been demonstrated to be accurate and reliable before its adoption. There are no reported programs available for training individuals in the use of self-measurement. A check-list has been developed for use by health care practitioners. It is estimated that proper training will usually take more than 20 mins. Since many health care practitioners do not use the recommended blood pressure measurement technique, there is also a need to develop programs to 'train the trainers'. Finally, individuals undertaking regular self-measurement should have their technique and the calibration of their instruments checked at regular intervals (six to 12 months).

Self-measurement of blood pressure: recommendations of the Canadian Coalition for High Blood Pressure Prevention and Control

OBJECTIVE

To provide health care professionals with guidelines on the use of blood pressure self-measurement.

METHODS

Recommendations were devised after consideration of expert reviews and guidelines, personal files, international standards documents, personal communication with investigators and the results of a MEDLINE search (1966-94) using the term 'blood pressure determination'.

BENEFITS, HARMS, COSTS

Self-measurement of blood pressure can be used to detect white coat hypertension, monitor changes in blood pressure closely, more rapidly achieve desired blood pressure goals, increase adherence to antihypertensive therapy and improve patient self-reliance. However, self-measured blood pressure readings may be misleading because there is insufficient normative, prognostic and outcome data and because some patients may not take accurate measurements. The use of self-measurement of blood pressure has a relatively small direct cost and may result in an overall reduction in treatment costs.

RECOMMENDATIONS

Self-measured blood pressure readings can be a valuable supplement to clinic (or office) blood pressure readings. However, self-measurement is appropriate neither for patients who are physically or mentally incapable of accurate assessment and interpretation of readings nor for those who do not want to participate. Patients who self-monitor blood pressure require careful training in blood pressure measurement and instruction on the recording and interpretation of blood pressure readings. Advice to patients using monitoring equipment must take into account the needs and abilities of the patient. Although only a few electronic devices for the self-measurement of blood pressure have met recommended performance standards, their use may be more appropriate for some patients and the training requirements fewer than if manual devices are used.

VALIDATION

The guidelines of several expert groups were examined in the preparation of these recommendations. The recommendations were presented at the World Conference on Hypertension Control in 1995 and were reviewed by the parent societies of the Canadian Coalition for High Blood Pressure Prevention and Control.

The assessment of student nurse learning styles using the Kolb Learning Styles Inventory

The learning styles of 192 Registered General Nursing/DipHE students was determined using the Kolb Learning Styles Inventory prior to the students having any formal contact with lecturing staff. The percentage of students having a predominantly concrete learning style was 53.7%, while 46.3% were predominantly reflective. This finding is in keeping with those of Laschinger & Boss (1984), who suggest that they are supportive of Kolb's theoretical tenet that concrete learners tend to choose people-oriented professions. Chi-squared tests were used to determine if the respondent's learning styles varied with either age, sex or having been in employment prior to becoming a nursing student; no statistically significant associations were found. A further chi-squared analysis was performed to see if there was a relationship between learning style and those students who possessed: 1) only the DC test, 2) O-levels as highest qualifications, and 3) A-levels as highest qualifications--no statistically significant associations were found. There remain measurement problems with the Kolb inventory, and a discussion of some of these issues are presented. The findings have reinforced the need for using a variety of delivery styles with students, with an emphasis on participation and experiential learning. This need for variety is essential given the distribution of learning styles found with the students. Nurse educators are urged to re-examine perceptions and assumptions about student learning needs.