[Monetary value of breast milk in Bolivia]

OBJECTIVE

To estimate the volume of breast milk consumed by Bolivian children under 36 months of age, and the monetary value of replacing that volume of breast milk with commercial substitutes.

METHODS

The analysis took into account the distribution of the infant population by age groups, the prevalence of breast-feeding practices (exclusive or partial) in every age group, the average volume of breast milk consumed by the infants of a given age group, and the cost of breast milk production and replacement.

RESULTS

Bolivian infants annually consume more than 161 million liters of breast milk, which represents an average volume of 573 mL/day per infant under 1 year of age. The monetary value of breast milk consumed by the Bolivian infants amounts to US$ 274 million annually. The average cost of replacing breast milk with commercial substitutes for an infant adequately breast-fed for the first year of life would be US$ 407.

DISCUSSION

For the formulation and consolidation of policies and programs to protect, promote, and support breast-feeding to become a reality, it is necessary that the political leaders of Bolivia be aware of the enormous monetary value of breast milk.

Clinical aviation medicine: safe travel by air

Commercial air travel has increased dramatically in the last 25 years, which has resulted in an increased number of passengers travelling. In 1995, approximately 1.4 billion passengers flew. There are very few contra-indications to flying in commercial jet aircraft and even passengers with medical conditions travel regularly without incident. To avoid in-flight emergencies which potentially have implications for the patient's medical condition and the operation of the flight it is essential to assess significant medical conditions prior to travel. With appropriate assessment by a physician who has an understanding of the aviation environment and its potential interaction with the patient's medical condition, the majority of passengers may be carried. If a medial emergency occurs in flight the medical practitioner may have a role to play when asked by the crew, whose training has recently been augmented by many airlines to include the use of self diagnosing defibrillators. This team approach is important and is of benefit to the patient; it may avoid disruption to the flight.

An industry, clinical, and academic telehealth partnership venture: progress, goals achieved, and lessons learned

The goal of this project was to develop and test a multi-application telehealth workstation with an interface seamless to the end-users. This project required collaboration among the private sector, a clinical regional referral setting, a clinical tertiary receiving center, and a university academic unit. The project applied the usability testing methodology to design and test the workstation: (1) the developmental phase focused on planning, prototype workstation development, and end-user trials in the private sector research and development environment, and (2) the operational testing phase moved the workstation into the clinical setting. The latter included training of end-users and addressing policy and ethical issues. In addition, the partners documented the goals achieved and lessons learned. The project resulted in the refinement of the workstation for clinical applications. The unique, diverse, and at times complementary goals and lessons learned by each partner are noted. Collaboration around a shared goal was a key element in achieving the refined workstation. Collaborators reported that the lessons learned will aid them as they pursue telehealth activities.

Analysis of chimaerism in thalassaemic children undergoing stem cell transplantation

We have prospectively assessed the relative contribution of host and donor to haemopoiesis following stem cell transplantation (SCT) in children with beta-thalassaemia major (n = 35), using karyotype analysis or Southern blot/polymerase chain reaction analysis of variable number tandem repeats on genomic DNA from peripheral blood. Early haemopoiesis was fully donor in origin in 24 out of 35 cases and remained so throughout the post-transplant course in all but one patient, who evolved to stable mixed chimaerism. The remaining 11 cases (31%) initially showed mixed chimaerism: four of these rejected, one eventually eradicated host haemopoiesis to become fully donor haemopoietic, and the remaining six had persistent mixed chimaerism, with 5--38% host haemopoiesis. The risk of graft rejection was high when > 15% host haemopoiesis was present at 3 months post transplant: four out of six such patients rejected their grafts; conversely, zero out of 29 patients with < 15% host haemopoiesis at 3 months rejected (P < 0.0001). There was a higher incidence of significant acute and chronic graft-versus-host disease in patients with full donor chimaerism. These studies confirm that the mixed chimaeric state is common following SCT for thalassaemia, often persists (with up to 4 years follow-up) and is compatible with long-term cure. Analysis of chimaerism in patients undergoing SCT for beta-thalassaemia enables monitoring of engraftment in the early post-transplant period, provides insight into the biology of engraftment and may be useful in identifying patients at high risk of rejection.

Reduced sun exposure and tanning in children after 2 years of a school-based intervention (Australia)

OBJECTIVE

This paper presents the results of the evaluation of measured suntan and parent-reported sun exposure in participating children after 2 years of the Kidskin study, a 5-year school-based sun protection intervention undertaken in Perth, Western Australia (1995-1999).

METHODS

The study involves three groups: a control, a "moderate", and a "high" intervention group. Participants were 5 or 6 years of age at the beginning of the study. Control schools received the standard Health Education curriculum, while intervention schools received a multicomponent intervention including a specially designed curriculum. Children in the high intervention group also received program materials over the summer vacation and were offered sun-protective swimwear at low cost. At the end of the second summer, suntan was measured and parents completed a questionnaire about their child's sun-related behavior.

RESULTS

Children in the intervention groups--especially the high group--were less tanned at the end of the summer; this effect was greater for the back than for the forearms. These children were also reported to have received less sun exposure and made greater use of sun protection measures.

CONCLUSION

Intensive school-based interventions can reduce tanning and reported sun exposure in children.

Complications and prognostic factors in Vogt-Koyanagi-Harada disease

PURPOSE

To identify associations between complications of disease and final visual acuity in patients with Vogt-Koyanagi-Harada disease and to identify prognostic factors for disease outcome.

METHODS

All patients diagnosed with Vogt-Koyanagi-Harada disease at the Doheny Eye Institute or the Los Angeles County/University of Southern California Medical Center between 1983 and 1997 were reviewed. Data extracted included initial and final visual acuities, age, gender, ethnicity, complications, treatment, duration of disease, and number of recurrences.

RESULTS

One hundred one patients with Vogt-Koyanagi-Harada disease were identified, 68 (67%) of which were female. Mean age was 34 +/- 14 years (range, 8 to 75 years). Asians presented at a significantly older age than all other groups. One hundred three eyes (51%) developed at least one complication, including cataract in 84 eyes (42%), glaucoma in 54 eyes (27%), choroidal neovascular membranes in 22 eyes (11%), and subretinal fibrosis in 13 eyes (6%). Patients who developed at least one complication had a significantly longer median duration of disease and number of recurrent episodes of inflammation (P =.0001 for each) than did those patients who developed no complications. Statistically significant associations existed between poor final visual acuity and greater numbers of complications (P =.001), greater age at onset (P =.03), a longer median duration of disease (P =.03), and greater number of recurrent episodes of inflammation (P =.0004). Eyes possessing a better visual acuity at presentation were more likely to have a better visual acuity at final follow-up (P =.001).

CONCLUSIONS

Factors associated with a worse final acuity included increasing numbers of complications, greater age at onset, and worse acuity at presentation.

An evaluation of the performance of cDNA microarrays for detecting changes in global mRNA expression

The cDNA microarray is one technological approach that has the potential to accurately measure changes in global mRNA expression levels. We report an assessment of an optimized cDNA microarray platform to generate accurate, precise and reliable data consistent with the objective of using microarrays as an acquisition platform to populate gene expression databases. The study design consisted of two independent evaluations with 70 arrays from two different manufactured lots and used three human tissue sources as samples: placenta, brain and heart. Overall signal response was linear over three orders of magnitude and the sensitivity for any element was estimated to be 2 pg mRNA. The calculated coefficient of variation for differential expression for all non-differentiated elements was 12-14% across the entire signal range and did not vary with array batch or tissue source. The minimum detectable fold change for differential expression was 1.4. Accuracy, in terms of bias (observed minus expected differential expression ratio), was less than 1 part in 10 000 for all non-differentiated elements. The results presented in this report demonstrate the reproducible performance of the cDNA microarray technology platform and the methods provide a useful framework for evaluating other technologies that monitor changes in global mRNA expression.

Physical and transcript map of the dominant optic atrophy (OPA1) gene critical region at 3q28-q29

The dominant optic atrophy gene (OPA1) has previously been mapped to chromosome 3q28-q29. We have now constructed a physical and transcriptional map across the OPA1 critical region between markers D3S3557 and D3S3346. It comprises 21 sequence-tagged sites (STSs), 4 single nucleotide polymorphisms, 29 expressed sequence tags, 2 known genes, and 12 newly generated STSs anchored onto 21 yeast artificial chromosome, 22 bacterial artificial chromosome, 48 P1 phage artificial chromosome, and 42 cosmid overlapping clones spanning 2.5 Mb. The map has allowed us to order many of the markers hitherto only roughly defined and to exclude 23 of the putative candidate genes assigned to the region. We found the OPA1 critical interval to be 450-550 kb. It contains 2 known genes, RPL35a and SDHA, which thus constitute candidate genes.

Influenza virus (A/HK/156/97) hemagglutinin expressed by an alphavirus replicon system protects chickens against lethal infection with Hong Kong-origin H5N1 viruses

Venezuelan equine encephalitis virus replicon particles (VRP) containing the gene expressing hemagglutinin (HA) from the human Hong Kong Influenza A isolate (A/HK/156/97) were evaluated as vaccines in chicken embryos and young chicks. Expressed HA was readily detected in bird-tissue staining with anti-H5 HA antibody and in chicken cells infected with the replicon preparations following immunoprecipitation with monoclonal antibody. Birds challenged with a dose of the lethal parent virus were protected to different extents depending on the age of the bird. In ovo and 1-day-old inoculated animals that received no boost with the VRP were partially protected; birds 2 weeks of age were completely protected with a single dose of VRP.

Short Report: Engraftment of T-cell-depleted allogeneic haematopoietic stem cells using a reduced intensity conditioning regimen

Graft-versus-host disease (GVHD) remains a significant complication in patients undergoing allogeneic stem cell transplantation (SCT) using a reduced intensity conditioning regimen. Although T-cell depletion (TCD) reduces the risk of GVHD after a myeloablative conditioning regimen, it is associated with an increased risk of graft failure. We have therefore examined whether TCD compromises engraftment using a fludarabine-based conditioning regimen. Fifteen patients have been transplanted using such a regimen of whom 13 underwent ex vivo TCD. All but one patient demonstrated durable engraftment and no patient receiving a TCD product developed severe GVHD. Thus, TCD may play a role in GvHD prophylaxis using such regimens.

Improved sun protection behaviour in children after two years of the Kidskin intervention

OBJECTIVE

To evaluate a school-based intervention in terms of reducing children's sun exposure and improving their use of sun protection measures.

METHODS

'Kidskin' is a five-year, school-based intervention study in Perth, Western Australia, of a cohort of children who were five or six years old in 1995. The study involves three groups: control, 'moderate' and 'high' intervention. Children in the control schools received the standard health curriculum; those in the intervention schools received a multicomponent intervention, including a specially designed curriculum. Children in the high intervention group also received program materials over the summer holidays and were offered sun-protective swimwear at a low cost. After two years, parents completed a questionnaire about their child's sun-related behavior.

RESULTS

Children in the intervention groups--especially the 'high' group--were reported to have had less sun exposure. This involved covering the back more often, spending more time in the shade when outdoors and wearing a style of swimsuit that covered the trunk. There was also evidence that children in the intervention groups spent less time outdoors in the middle of the day. There was little difference between groups in the wearing of hats or sunscreen.

CONCLUSIONS

Our school-based intervention improved children's sun protection, but had little effect on specific behaviours that have already been vigorously promoted.

IMPLICATIONS

School-based prevention campaigns would benefit from focusing on sun protection using clothing and shade, and reducing sun exposure in the middle of the day. There may be little potential to improve hat and sunscreen use.

Telelearning in a partnership between a university faculty and a regional health authority: benefits, challenges and strategies

The University of Calgary's Faculty of Medicine and the Calgary Regional Health Authority understand that telehealth is an evolving field requiring both academic enquiry and operational readiness. Both parties are committed to quality educational programmes--the Faculty through its commitment to excellence and the Authority with its charge to maintain and enhance such programmes. There are shared applications, multi-learner user groups, shared strategies to overcome distances and shared infrastructure--technologies, communication pathways and resources. Having embarked on a joint telelearning venture, we have learned a number of lessons. Central to progress has been an appreciation and respect for unique mandates, a spirit of trust and flexibility, an agreement on a set of principles, ongoing communication between and participation from the users and, at times, redirection. Questions being answered include the following. How well is this collaborative model working? How functional is it at this time of health reform and restructuring? Can one meet complementary telelearning goals within a faculty-health authority relationship? These all have implications for future success.

Development of a toxicological gene array and quantitative assessment of this technology

High-density arrays of DNA bound to solid substrates offer a powerful approach to identifying changes in gene expression in response to toxicants. While DNA arrays have been used to explore qualitative changes in gene regulation, less attention has focused on the quantitative aspects of this technology. Arrays containing expressed sequence tags for xenobiotic metabolizing enzymes, proteins associated with glutathione regulation, DNA repair enzymes, heat shock proteins, and housekeeping genes were used to examine gene expression in response to beta-naphthoflavone (beta-NF). Upregulation of cytochrome P4501a1 (Cyp1a1) and 1a2 in mouse liver was maximal 8 h after beta-NF administration. Significant upregulation of Cyp1a2 was noted at beta-NF doses as low as 0.62 and 1.2 mg/kg when gene expression was measured by microarray or Northern blotting, respectively. Maximal Cyp1a2 induction is 5-fold by Northern analysis and 10-fold by microarray. Induction of Cyp1a1 was 15- and 20-fold by Northern and microarray analysis, respectively. The coefficient of variation for spot to spot and slide to slide comparisons was <15%; this variability was smaller than interanimal variability (18-60%). Comparison of mRNA expression in control animals indicated that there are differences in labeling/detection associated with Cy3/Cy5 dyes; accordingly, experiments must include methods for establishing baseline signals for all genes. We conclude that the dynamic range and sensitivity of DNA microarrays on glass slides is comparable to Northern blotting analysis and that variability of the data introduced during spotting and hybridization is less than the interanimal variability.

Simvastatin-induced rhabdomyolysis in an HIV-infected patient with coronary artery disease

As greater numbers of human immunodeficiency virus (HIV)-infected individuals live to middle-age and beyond, there is growing concern that elevated cholesterol and lipid values will lead to cardiovascular complications in such patients. Furthermore, several of the highly active antiretroviral therapies (HAART) used to reduce levels of circulating HIV and extend acquired immunodeficiency syndrome (AIDS)-related survival are associated with a rise in plasma lipids. Anecdotal reports suggest such rises may be linked to cardiovascular complications. Herein, we review the case of a 74-year-old HIV-infected man with advanced coronary artery disease. He was prescribed simvastatin for control of hyperlipidemia and within 4 weeks developed muscle pain, proximal muscle weakness, myoglobinuria, and a markedly elevated creatinine phosphokinase (CPK). Simvastatin was discontinued, and rhabdomyolysis improved rapidly with conservative care. This report emphasizes this rare, but potentially significant, side effect of statin anticholesterol agents. Medical providers who prescribe statins must remember to check CPK levels when their HIV-infected patients complain of muscle pain. Discontinuing the offending drug will usually result in rapid diminution of muscle pain and inflammation and improve muscle strength.

The relationships among pulmonary function, aerobic fitness, and cognitive functioning in older COPD patients

STUDY OBJECTIVES

To study the predictive relationships among age, pulmonary function, aerobic fitness, and cognition in people with COPD.

DESIGN

Observational study conducted during baseline testing with COPD patients who volunteered to participate in an exercise intervention.

PARTICIPANTS

Older adults (age, 56 to 80 years) with COPD.

MEASUREMENTS AND RESULTS

Age, depression, education level, aerobic fitness, blood oxygen saturation levels, and pulmonary function were assessed. Participants were randomly assigned to take cognitive tests of (1) fluid intelligence, (2) processing speed and working memory span, or (3) processing speed and inhibition. After controlling for education and depression (F(2,57) = 7.43; r(2) = 0. 21), performance on the 6-min walk (F(1,56) = 15.27; r(2) = 0.17) and age (F(1,55) = 7.52; r(2) = 0.08) were significant predictors of fluid intelligence. On the speed-of-processing task, performance on the 6-min walk (F(1,30) = 8.17; r(2) = 0.20), maximum voluntary ventilation (F(1,29) = 5.81; r(2) = 0.16), and age (F(1,28) = 5.26; r(2) = 0.10) were significant predictors. FVC was a significant predictor (F(1,25) = 6.37; r(2) = 0.18) of working memory span. The ability to inhibit a response was not significantly predicted by any of the variables assessed.

CONCLUSIONS

In an older COPD sample, age, aerobic fitness, and pulmonary function are predictive of cognitive performance on various tasks. In particular, age and aerobic fitness are predictive of speed of processing, which is a cognitive variable that may itself underlie performance on a majority of cognitive tasks.

Evaluation of an intervention to reduce sun exposure in children: design and baseline results

The Kidskin Study is a 5-year intervention study (1995-1999) involving 1,776 5- and 6-year-old children attending 33 primary schools in Perth, Western Australia. The aim of the study is to design, implement, and evaluate an intervention to reduce sun exposure in young children. There are three study groups: a control group, a "moderate intervention" group, and a "high intervention" group. The control schools receive the standard Western Australian health education curriculum, while the moderate and high intervention schools receive a specially designed curricular intervention. In addition, children in the high intervention group receive program materials over the summer holidays, when exposure is likely to be highest, and are offered sun-protective swimwear at low cost. The main outcome measure is the number of nevi on the back. Other outcomes include nevi on the chest (boys only), face, and arms, levels of suntanning, degree of freckling, and sun-related behaviors. At baseline, the three groups were similar with respect to nevi and freckling after adjustment for observer and month of observation. Sun exposure was slightly higher in the high intervention group. The groups were also similar with respect to most potential confounders, although they differed with respect to Southern European ethnicity and parental education.

Direct measurement of sun protection in primary schools

BACKGROUND

"Kidskin" is an intervention study involving children at 33 primary schools in Perth, Western Australia. This study includes measurement of changes in implementation of schools' sun protection policies. This paper reports on measurement of observable aspects of sun protection.

METHODS

Hat use was assessed from videos of children in the playground. Shade use was measured using UVR-sensitive polysulfone badges worn by a random sample of children. Shade provision was measured from aerial photographs of the schools. Principals were surveyed about school policies and practices.

RESULTS

Eighty-seven percent of children wore a hat during lunch time at school, although only 14% wore the most protective styles of hats. The mean proportion of ambient UVR exposure received by Year 1 children was 15.5%; children spent less time in the sun on sunnier days. On average, 14.5% of the playground was shaded; this was not associated with children's sun exposure. Correlations between these results and the principals' estimates were poor.

CONCLUSIONS

Children should be encouraged to wear more protective styles of hats and to avoid sun exposure, even on less sunny days during spring and summer. Principals' estimates of shade provision and children's sun protection behavior at school are of little value.

A double-blind, multicentre study to assess the tolerability and efficacy of paroxetine compared with amitriptyline in the treatment of depressed patients in Australian general practice

OBJECTIVE

This study compared the tolerability and efficacy of paroxetine and amitriptyline in the treatment of depression in general practice.

METHODS

In this double-blind, multicentre study conducted in the general practice, patients with depression (Montgomery Asberg Depression Rating Scale [MADRS] score > or = 20) who were regarded as requiring antidepressant therapy were randomly assigned to receive paroxetine (20 mg, n = 184) or amitriptyline (50-100 mg, n = 191) once daily for 9 weeks.

RESULTS

More patients completed treatment with paroxetine than with amitriptyline (71.1% vs 56.1%, p = 0.009). Depression rating scores (MADRS and Clinical Global Impression [CGI]) were improved with both agents, but at week 9, paroxetine achieved more favourable scores compared with amitriptyline on MADRS (p=0.019), CGI severity of depression (p=0.044), and CGI efficacy index (p = 0.038).

CONCLUSIONS

Depressed patients treated in general practice respond more quickly and are more likely to complete the treatment regimen with paroxetine than with amitriptyline.

The use of observational methods for monitoring sun-protection activities in schools

Evaluation of health promotion interventions aimed at behavioural or environmental change involves assessing change that occurs as a result of the program. Direct observational methods can be used for this purpose and this paper describes three such methods that we pilot tested for use in a 5-year intervention study aimed at reducing sun exposure in primary school children. (1) Monitoring 'No hat, no play' policies. This method involved video taping children in selected school play areas during lunch time and analysing the content of the videos to assess the proportion of children wearing various types of hats. (2) Assessing shade provision in the playground. This method involved taking aerial photographs of each school and using them to estimate the proportion of shade in play areas available to children at lunchtime. (3) Shade use. This involved children wearing polysulphone film badges to measure the amount of UV-B exposure they received during one lunch period, relative to the total possible dose registered on index badges. Each method was implemented successfully, and we demonstrated that the video and aerial photography methods produced highly reproducible results and that all three methods were feasible. These three methods will be used in our intervention study to assess longitudinal change in schools' sun-protection policy and practice.

Is it 'worthwhile' to continue treating patients with a prolonged stay (>14 days) in the ICU? An economic evaluation

OBJECTIVE

To compare the cost and consequences of a policy of continuing to care for patients with a prolonged stay in the ICU with a proposed policy of withdrawing support.

DESIGN

Economic evaluation using data derived from a prospective cohort study.

SETTING

Adult medical/surgical ICU in a tertiary care hospital.

PATIENTS

Consecutive patients admitted to the ICU.

INTERVENTION

None.

MAIN OUTCOME MEASURES

We performed a cost-accounting analysis on each patient in the ICU and followed up patients until 12 months after admission to ICU and assessed components of quality of life in survivors.

RESULTS

During the study period, 690 patients were admitted to the ICU. Only 61 (9%) patients remained in the ICU for > 14 days. For this group, the mean length of stay in the ICU was 24.5 (+/-11.7) days and duration in hospital was 57.9 (+/-56.9) days. At 12 months, 27 (44%) were alive. Overall, the mean quality of life score at 12 months did not differ between patients with a short or prolonged stay in the ICU. The average ICU cost per day per patient was $1,565 (Canadian) resulting in a total cost for the whole cohort of Can $1,917,382. Over the same time period, 58 patients had life support withdrawn. On average, patients survived another day in the ICU, 2 more days in hospital, and all patients ultimately died. When treatment was discontinued, the costs of treating this cohort was Can $156,465. The incremental cost-effectiveness ratio is Can $65,219 per life saved or Can $4,350 per life-year saved.

CONCLUSIONS

A considerable proportion of patients with a prolonged length of stay in the ICU survive their critical illness. Furthermore, their long-term quality of life seems reasonable. Our data suggest that continuing treatment for patients with a prolonged ICU stay may represent an efficient use of hospital resources and should be considered in the context of local budgets.

Air insufflation technique of enteral tube insertion: a randomized, controlled trial

OBJECTIVE

To test air insufflation as an adjunct to placement of enteral feeding tubes.

DESIGN

Prospective, randomized study.

SETTING

Intensive care unit in a tertiary hospital.

SUBJECTS

Sixty-four consecutive patients requiring enteral nutrition, in whom a decision to insert a nasoenteral feeding tube was made.

INTERVENTIONS

A 12-Fr feeding tube was inserted to the level of the fundus of the stomach. A 60-mL syringe was used to pump 500 mL of air into the stomach. The tube was then advanced. An abdominal flat plate was obtained within 2 hrs of completion of the procedure and the tube position noted. If the tube was not in the duodenum, the patient was placed on a promotility agent and a repeat radiograph was performed the next day. The technique varied from our control technique only by the instillation of air.

MEASUREMENTS AND MAIN RESULTS

Using the study technique, 21 of 32 tubes were successfully placed, as seen on the initial radiograph, in our study patients compared with only 12 of 34 tubes in our control patients (p< .02). In addition, the success rate at 24 hrs was 25 of 32 vs. 16 of 34 (p< .02). Only 3 of 21 tubes placed in the antrum, body, or fundus of the stomach advanced to the duodenum the following day, compared with 5 of 12 tubes initially placed in the pylorus (p< .075). No complications were noted.

CONCLUSION

Instilling air into the stomach may facilitate the ability to get the feeding tube to the level of the pylorus, at which point it is more likely to advance into the duodenum and beyond.

Targeted lung expression of interleukin-11 enhances murine tolerance of 100% oxygen and diminishes hyperoxia-induced DNA fragmentation

Acute lung injury is a frequent and treatment-limiting consequence of therapy with hyperoxic gas mixtures. To determine if IL-11 is protective in oxygen toxicity, we compared the effects of 100% O2 on transgenic mice that overexpress IL-11 in the lung and transgene (-) controls. IL-11 markedly enhanced survival in 100% O2 with 100% of transgene (-) animals dying within 72-96 h and > 90% of transgene (+) animals surviving for more than 10 d. This protection was associated with markedly diminished alveolar-capillary protein leak, endothelial and epithelial membrane injury, lipid peroxidation, and pulmonary neutrophil recruitment. Significant differences in copper zinc superoxide dismutase and catalase activities were not noted and the levels of total, reduced and oxidized glutathione were similar in transgene (+) and (-) animals. Glutathione reductase, glutathione peroxidase, and manganese superoxide dismutase activities were slightly higher in transgene (+) as versus (-) mice after 100% O2 exposure, and IL-11 diminished hyperoxia-induced expression of IL-1 and TNF. Hyperoxia also caused cell death with DNA fragmentation in the lungs of transgene (-) animals and IL-11 markedly diminished this cell death response. These studies demonstrate that IL-11 markedly diminishes hyperoxic lung injury. They also demonstrate this protection is associated with small changes in lung antioxidants, diminished hyperoxia-induced IL-1 and TNF production, and markedly suppressed hyperoxia-induced DNA fragmentation.

High-throughput genetic analysis using microfabricated 96-sample capillary array electrophoresis microplates

Capillary array electrophoresis (CAE) microplates that can analyze 96 samples in less than 8 min have been produced by bonding 10-cm-diameter micromachined glass wafers to form a glass sandwich structure. The microplate has 96 sample wells and 48 separation channels with an injection unit that permits the serial analysis of two different samples on each capillary. An elastomer sheet with an 8 by 12 array of holes is placed on top of the glass sandwich structure to define the sample wells. Samples are addressed with an electrode array that makes up the third layer of the assembly. Detection of all lanes with high temporal resolution was achieved by using a laser-excited confocal fluorescence scanner. To demonstrate the functionality of these microplates, electrophoretic separation and fluorescence detection of a restriction fragment marker for the diagnosis of hereditary hemochromatosis were performed. CAE microplates will facilitate all types of high-throughput genetic analysis because their high assay speed provides a throughput that is 50 to 100 times greater than that of conventional slab gels.

Laser safety analysis of a retinal scanning display system

The Virtual Retinal Display (VRD) is a visual display that scans modulated laser light on to the retina of the viewer's eye to create an image. Maximum permissible exposures (MPE) have been calculated for the VRD in both normal viewing and possible failure modes. The MPE power levels are compared to the measured power that enters the eye while viewing images with the VRD. The power levels indicate that the VRD is safe in both normal operating mode and in failure modes.

Building a virtual reality temporal bone dissection simulator

The temporal bone is one of seven bones that comprise the human skull, and has an intimate relationship with many vital structures. Anatomically, its three-dimensional relationships make it one of the most challenging areas for surgeons to understand and master. In addition, the temporal bone contains minute structures that are among the most sophisticated and delicate in the human body. These structures include the cochlea and vestibular organs, which are responsible for hearing and balance; the middle ear, including the ossicles, which conduct acoustic energy to the cochlea; and the facial nerve, which is responsible for controlling the muscles of facial expression, and contributes to the sensation of taste. Additionally, the temporal bone forms a major portion of the skull base, and has intimate relationships to vital structures including the carotid artery, jugular vein, cerebral cortex, brainstem, and cranial nerves. Surgical procedures performed on the temporal bone include: procedures to eradicate chronic and acute infections; procedures to remove malignant and benign tumors within the temporal bone, from the skull base, or from the posterior cranial fossa; procedures to restore the hearing mechanism; procedures to eliminate balance disorders; and procedures to correct congenital anomalies. For surgeons-in-training, and even surgeons-in-practice, mastery of the anatomy of the temporal bone and the many complex approaches necessary to treat patients takes years of focused endeavor. This is typically accomplished through the dissection of human cadaver temporal bones, which are scarce, and require a dedicated laboratory facility. Efforts are currently underway to develop a realistic simulator for temporal bone procedures. Users immersed in the simulator will interact with a three-dimensional temporal bone, derived from patient-specific data, using a haptic interface to simulate traditional surgical procedures. Feedback from experts in otologic surgery will be built into the system for additional instruction. This presentation will include an overview of the application being developed, a report of its current state of development, and plans for the future.

Virtual reality surgical simulation and otolaryngology

Large-scale flight simulation was pioneered in the 1940s to help meet the training requirements and demand for pilots in World War II. Flight simulators have been effective for training, evaluating, and certifying military and commercial pilots. Accurate scenarios have been developed that allow pilots in training to gain experience without the risk and expense of learning while in flight. The research in aviation simulation suggests a transfer effectiveness ratio of 0.48. This means that 1 hour in the simulator saves a half hour in the air. Because of the successful use of flight simulation as a training technique, computer-based simulators are now used in a variety of domains.

Vitamin D receptor genotype is not associated with bone mineral density in three ethnic/regional groups

We report a cross-sectional study of 48 men, 56 premenopausal women, and 80 postmenopausal women who were of three ethnic/regional backgrounds: southern European (Greek, Italian), eastern European (Jewish, Polish, Hungarian), and western European (French, British). We determined bone mineral density (BMD) at four skeletal sites and assessed the vitamin D receptor (VDR) genotype by the Bsml restriction site polymorphism. Age and body mass index had significant effects on BMD by multiple regression analysis. In addition, ethnic/regional group had a significant effect on spinal BMD in premenopausal females (P = 0.014) and in males (P = 0.039). However, VDR genotype had no significant effect on BMD in any of the three study groups.

Optimal positioning for cervical immobilization

STUDY OBJECTIVE

We hypothesized that optimal positioning of the head and neck to protect the spinal cord during cervical spine immobilization can be determined with reference to external landmarks. In this study we sought to determine the optimal position for cervical spine immobilization using magnetic resonance imaging (MRI) and to define this optimal position in a clinically reproducible fashion.

METHODS

Our subjects were 19 healthy adult volunteers (11 women, 8 men). In each, we positioned the head to produce various degrees of neck flexion and extension. This positioning was followed by quantitative MRI of the cervical spine.

RESULTS

The mean ratio of spinal canal and spinal cord cross-sectional areas was smallest at C6 but exceeded 2.0 at all levels from C2 to T1 (P < .05). At the C5 and C6 levels, the maximal area ratio was most consistently obtained with slight flexion (cervical-thoracic angle of 14 degrees) (P < .05). For a patient lying flat on a backboard, this corresponds to raising the occiput 2 cm. More extreme flexion or extension produced variable results.

CONCLUSION

In healthy adults, a slight degree of flexion equivalent to 2 cm of occiput elevation produces a favorable increase in spinal canal/spinal cord ration at levels C5 and C6, a region of frequent unstable spine injuries.

Do Difficulties in Stimulus Discrimination Affect Luminance Processing?

Simple reaction time is known to decay as a hyperbolic function of luminance (Piéron's function). An identical relationship has also been demonstrated recently (Pins and Bonnet, 1996 Perception & Psychophysics in press) with different choice-reaction-time tasks. Although mean choice reaction time increased with the complexity of the task, the exponents of the functions relating reaction time (RT) to luminance were found to be equal in each experiment. These results suggest that the task specific time required by the different tasks only adds to the time necessary for luminance processing. In these experiments, the different stimuli presented were easily discriminable.

In the present study, we examined the effect of variation in luminance on a more difficult discrimination task involving variation in orientation. Five different luminance levels covering the entire mesopic range were used. In two conditions, tilted lines at nine different angles were used, at a spacing of 2°. In the first condition, the orientations were chosen on both sides of the vertical (the subject responded “left” or “right”); in the second condition, the orientations were on both sides of a line oriented at −40° to the vertical (the subject responded “high” or “low”). The results were compared to those of a second experiment in which only two easily discriminable orientations were used. The results show that RT is greater in the experiments in which nine orientations are used, while the effect of intensity on RT is lower. This effect does not depend on orientation.

Unusual complications of cervical spine surgery for cervical myelopathy in rheumatoid arthritis

Cervical myelopathy is a recognized complication of rheumatoid arthritis and other inflammatory arthropathies. In a significant proportion of patients, surgical stabilization of the cervical spine offers the best opportunity for improvement of symptoms and long-term survival. We report two cases that illustrate some potential complications of cervical spine surgery and which also emphasize the need for vigilance when caring for patients in this group.

Cost accounting of adult intensive care: methods and human and capital inputs

OBJECTIVE

To cost adult intensive care by determining inputs to production, resource consumption per patient, and total cost per intensive care unit (ICU) stay.

DESIGN

Prospective cost-accounting analysis of each patient stay in the ICU, over a 1-yr period.

SETTING

An 11-bed, medical/surgical adult ICU, in a 932-bad urban teaching hospital.

PATIENTS

All patients' admissions to an adult ICU over a 1-yr period, excluding those patients admitted solely for repeat hemodialysis.

INTERVENTIONS

None.

MEASUREMENT AND MAIN RESULTS

Demographic information was collected, including age, gender, Acute Physiology and Chronic Health Evaluation (APACHE) II score, primary reason for ICU admission, operative (elective and emergency) and nonoperative status, ICU length of stay, and ICU outcome. Direct patient care costs were accounted to individual patients whose care generated those costs, and indirect patient care costs were averaged over all patients in the ICU on a daily basis. Costs were collected for human (nursing, medical, professional, and support staff) and capital (laboratory, diagnostic imaging, supplies, drugs, and equipment) resources. Cost information was available on 690 patients (43% female, 57% male). Cost/day/patient was $1,508 +/- 475 (1992 Canadian dollars) and the average cost per ICU stay was $7,520 +/- 11,606. Median cost/stay for all patients was $2,600. Cost per ICU stay was < $5,000 in 68% of patients, with an ICU survival rate of 85%. High cost was not a marker for poor survival. There was no relationship between age and cost categories. Across most diagnoses, cost/ day/patient was remarkably constant, approximating $1,500/day/ patient at existing labor rates.

CONCLUSIONS

In order to develop strategies aimed at cost containment, it is first necessary to undertake a thorough examination of cost drivers. This detailed cost-accounting study determined inputs to production, resources consumed by individual patients, and costs incurred during ICU stay.

Implementation of a capillary array electrophoresis instrument

A capillary array electrophoresis (CAE) apparatus capable of running and analyzing DNA samples in 48 capillaries simultaneously has been constructed. The capillaries are individually replaceable, and sieving buffer can be easily pumped in and out of the capillary array as necessary. Samples are injected electrokinetically from polymerase chain reaction (PCR, Hoffmann-LaRoche, Nutley, NJ, U.S.A.) tubes arranged in a 6 x 8 format and are detected by laser-induced fluorescence. Data analysis software has been developed for semiautomatic analysis, including peak finding and DNA fragment sizing. The system represents a robust apparatus for the rapid and convenient analysis of DNA fragments in a high-throughout environment.

DNA sequencing by capillary electrophoresis with a hydroxyethylcellulose sieving buffer

Capillary electrophoresis (CE) is capable of rapid, high-resolution separations of DNA. The technique has been adopted for both ssDNA and dsDNA applications. In order to make CE more convenient and cost-effective, replaceable sieving buffers have recently been developed. For DNA sequencing, the most successful of these replaceable buffers have been carefully polymerized and purified viscous linear polyacrylamide solutions. However, the hazards of acrylamide are well documented, and the care required to prepare the appropriate molecular weight polymer make this approach less than ideal. We report use of a replaceable sieving buffer suitable for DNA sequencing by CE that is easy to prepare and uses commercially available, non-toxic hydroxyethylcellulose.

Assessing a virtual reality surgical skills simulator

The Institute for Defense Analyses (IDA) was contracted to perform a military standard task analysis of laparoscopic cholecystectomy, and to study the effectiveness of a virtual reality surgical skills simulator as a tool for surgical training and as a method for recording psychomotor behavior. This report describes the purpose of the study, its design, initial results, and implications for the field of medical education.

The role of computer-based simulation for training surgeons

The effectiveness of computer based simulation (CBS) technology for training surgeons has yet to be determined. However, there is a body of research that demonstrates the effectiveness of this technology for other training applications. This research also indicates the substantial savings in cost, time, and effectiveness of simulation.

Quality of life measures before and one year after admission to an intensive care unit

OBJECTIVE

To assess outcome of patients admitted to an intensive care unit (ICU), using a prospective 1-yr follow-up, with special emphasis on various quality of life measures before and after admission to the ICU.

DESIGN

Prospective comparison of quality of life before and 1 yr after admission to the ICU.

SETTING

Eleven-bed adult medical/surgical ICU.

PATIENTS

All patients admitted to the ICU over a 1-yr period were eligible for inclusion in this study. Repeat admissions were enrolled only on first admission. Patients < 17 yrs of age and those patients who died within 24 hrs of admission were excluded.

INTERVENTIONS

Quality of life measures were collected before and 6 and 12 months after ICU admission.

MEASUREMENTS AND MAIN RESULTS

The following data were collected: duration of ICU and hospital stay; ICU, hospital, 6- and 12-month mortality; quality of life (level of activity, activities of daily living, perceived health, support, and outlook on life) and place of residence at baseline and 12 months after ICU admission. There were 504 patients who met the study criteria; age 55 +/- 20 yrs (median 59), 229 female and 275 male. Mean ICU length of stay was 4.3 +/- 7.4 days. Hospital length of stay was 31 +/- 41 days. Acute Physiology and Chronic Health Evaluation II (APACHE II) score was 14 +/- 7. Cumulative mortality: ICU 5.4%, hospital 13.5%, 6 month 20.6%, and 12 month 25%. One year quality of life questionnaires were completed for 293 patients. Relative to baseline, there was a decrease in the level of activity and activities of daily living at 12 months (p < .01). Perceived health status increased over the year for patients > or = 75 yrs of age (p < .01). There was no difference in the level of support from family or friends, or outlook on life, at 12 months. At 1 yr, 262 (89%) patients were living at home.

CONCLUSION

Patients admitted to intensive care tend to have a decrease in the level of activity and activities of daily living 1 yr after their ICU stay, although in the very elderly, perceived health status increases. As well, the majority (89%) of patients return home.

Ability of spermatozoa to bind to the zona pellucida during oligozoospermia induced with testosterone during a male contraceptive trial

To determine the ability of spermatozoa to bind to the zona pellucida (ZP) in testosterone-induced oligozoospermia, previously fertile men participating in the World Heath Organization (WHO) male contraceptive trial in Melbourne were studied while oligozoospermic to various degrees. Semen analysis were performed according to WHO methods. One or two ejaculates from each subject were cryopreserved before commencing weekly intramuscular injections of 200 mg testosterone enanthate. The frozen spermatozoa were used as controls for ZP-binding tests of spermatozoa obtained during testosterone-induced oligozoospermia (< 10 x 10(6)/ml) in either the suppression or efficacy (n = 6) and recovery (n = 3) phases. Two other subjects in the recovery phase with normozoospermia were also tested. Human oocytes that failed to fertilized in vitro from infertile patients were used for the sperm-ZP binding test. Control (frozen) spermatozoa were labelled with fluorescein isothiocyanate and test (oligozoospermic semen) spermatozoa were labelled with tetramethylrhodamine B isothiocyanate. A mixture of equal numbers of labelled motile control and test spermatozoa were incubated with 4-6 ZP. There was a significantly (p < 0.01) lower number of spermatozoa bound per ZP in oligozoospermic samples (65 +/- 7, mean +/- SEM) than in controls (80 +/- 7). However, there were still large numbers of spermatozoa bound to the ZP for all the oligozoospermic samples. Five subjects had similar numbers of spermatozoa bound to the ZP for both control and oligozoospermic samples. Overall, the ZP-binding ratio of test and control spermatozoa averaged 0.82 (range 0.51-1.13).(ABSTRACT TRUNCATED AT 250 WORDS)

On the ground at the U.S. Air Show

Careful planning and organization at mass gatherings are essential if adequate medical care is to be ensured. The U.S. Air Show in Dayton, Ohio, attracts thousands of spectators annually and requires that dozens of EMS agencies and hundreds of first responders, EMTs, paramedics, nurses and physicians join forces to provide EMS coverage.

The influence of age, diagnosis, and gender on proper use of metered-dose inhalers

Metered dose inhalers (MDIs) are widely used in clinical practice for administering pharmaceuticals targeted to the lung. It is well known that the inhalation technique used with MDIs can substantially influence the clinical response to inhaled medications. To determine the acceptability of MDI maneuvers, we studied 59 subjects (26 females and 33 males; age, 20 to 81 yr; mean age, 38 yr) to determine whether the MDI technique used by these individuals complied with published recommendations for acceptable inhalation technique. Measurements were made with an MDI adapter that contained an unobtrusive, lightweight, miniature sensing system. Inspiratory flow at the moment of MDI actuation (Va), the volume (integrated from airflow) at actuation as a fraction of total inspiratory volume (Va/VI), breath-holding time (tBH), and inspiratory volume as a fraction of FVC (VI/FVC) were determined from 59 uncoached inhalations. We defined an acceptable maneuver, based on published data, by four components: (1) inspiratory flow at actuation (Va) between 25 and 90 L/min; (2) actuation during early inspiration (0 < Va/VI < or = 0.20); (3) adequate breath-holding time (tBH > 4 s), and (4) a deep inhalation (VI/FVC > 0.50). For all subjects, only 25% of inhalation maneuvers met all four criteria for acceptability. We found that a significantly higher proportion of male than female subjects performed an acceptable MDI maneuver (43% versus 4%, p < 0.001). There were no significant differences in technique between younger and older subjects or between patients with a diagnosis of asthma or chronic obstructive pulmonary disease (COPD). We conclude that most patients use their MDIs incorrectly; females of all ages are much more likely to have improper MDI technique than are males.

Forehead and forearm skin blood flows in newborn infants measured by laser Doppler flowmetry: short-term variability and relationship to sleep states

Laser doppler flowmeters were used to measure blood flow in the skin of the forehead and volar surface of the forearm of infants at 2-9 days of age, and at 8-12 weeks of age. At both ages mean skin blood flow was higher during active sleep compared to quiet sleep. In infants up to 9 days of age, mean skin blood flow was higher in forehead skin compared to forearm skin. Skin blood flow was highly variable at both recording sites, and was significantly higher and more variable during active compared to quiet sleep in the forehead, but not in the forearm. The results indicate that recordings of skin blood flow over at least two cycles of active and quiet sleep are needed to describe the normal variation with sleep state. The factors which regulate forehead and forearm skin blood flows may differ in importance between the two sites, perhaps reflecting the different thermoregulatory importance of cutaneous blood flow in the forehead and forearm.