Ascertainment of stroke from administrative data to support a pragmatic embedded clinical trial

The goal of this observational study was to identify stroke hospitalizations using International Classification of Disease (ICD)-10 codes and use these codes to develop an ascertainment algorithm for use in pragmatic clinical trials, reducing or eliminating the need for manual chart adjudication in future. Using VA (Veterans Affairs) electronic medical records, 9959 patient charts with ICD-10 codes indicating stroke were screened and a sample of 304 were adjudicated by three clinical reviewers. Hospitalizations were categorized as stroke or non-stroke and positive predictive value (PPV) was calculated for each ICD-10 code that was sampled. The adjudicated codes were categorized for use in a decision tool for identifying stroke in a clinical trial. Of the 304 hospitalizations adjudicated, 192 met the definition of stroke. Of the ICD-10 codes evaluated, I61 yielded the highest PPV (100%) while I63.x yielded the 2nd highest PPV (90%) with a false discovery rate of 10%. A relatively high PPV of ≥80% was associated with codes I60.1-0.7, I61, I62.9 and I63, which accounted for nearly half of all cases reviewed. Hospitalizations associated with these codes were categorized at positive stroke cases. The incorporation of large administrative datasets, and elimination of trial specific data collection, increases efficiencies, while reducing costs. Accurate algorithms must be developed to allow for identification of clinical endpoints from administrative databases to offer a reliable alternative to study-specific case report form completion. This study demonstrates an example of how to apply medical record data to a decision tool for clinical trial outcomes. CSP597 or clinicaltrials.gov NCT02185417.

620. Pharmacokinetic-Pharmacodynamic Analysis of Oral Vancomycin and Gut Microbiome Changes in Healthy Volunteers: an Exploratory Study

Background

Oral vancomycin causes profound changes to the gut microbiome due to high intra-colonic vancomycin concentrations. However, pharmacokinetics of oral vancomycin causing pharmacodynamic changes have not been explored, especially during the early dosing period. The purpose of this study was to investigate fecal vancomycin concentrations in healthy individuals in relation to gut microbiome diversity changes.

Methods

Healthy subjects 18-45 years with no antibiotic use for at least 28 days were given oral vancomycin 125 mg was given every 6 hours for 10 days. Stool samples were collected at baseline and during antibiotic therapy. Vancomycin concentrations were obtained through high-performance liquid chromatography (HPLC) assay. For this early pharmacokinetics analysis, stool samples from day 0 (baseline) to day 4 were included. Shotgun metagenomics sequencing was used for microbiome analysis. Descriptive analysis was performed to identify gut-microbiome phyla changes in correlation with detectable oral vancomycin fecal concentrations.

Results

A total of 6 healthy volunteers aged 32±5 years (Male: 100%; Caucasian: 50%; mean BMI: 26.8±4.5 kg/m²) were included. In the early dosing period (day 0-4), the mean fecal vancomycin concentrations increased daily with the highest concentration of 1,586 μg/g of stool occurring on day 4. Three of 9 subjects (50%) had undetectable oral vancomycin levels one days 1 and 2 of dosing. Within 24-48 hour of detectable vancomycin levels, subject-specific changes of gut microbiome phylum-level proportions were observable. Overall, an increase in Actinobacteria and Proteobacteria phyla and decrease in Firmicute phylum was observed within 24 hours that vancomycin was detected in the feces.

Conclusion

High concentrations of vancomycin are achieved in the stool by day four of dosing for all subjects; however, low concentrations are observed early in the dosing period for some subjects. Proportional, subject specific differences in gut microbiome phyla were observed within 24 hours of detectable vancomycin levels in the feces.

Disclosures

Kevin W. Garey, PharmD, MS, Acurx Pharmaceuticals: Grant/Research Support|Paratek Pharmaceuticals: Grant/Research Support|Seres Therapeutics: Grant/Research Support|Summit Pharmaceuticals: Grant/Research Support.

Efficacy, Safety, Pharmacokinetics, and Microbiome Changes of Ibezapolstat in Adults with Clostridioides difficile Infection: A Phase 2a Multicenter Clinical Trial

Background

This study was the first human validation of the gram-positive bacterial DNA polymerase IIIC target in patients with Clostridioides difficile infection. The primary objectives were to assess clinical cure rates and adverse events (AEs). Secondary objectives were to evaluate plasma/fecal pharmacokinetics, microbiologic eradication, microbiome and bile acid effects, and sustained clinical cure (SCC) with ibezapolstat.

Methods

This single-arm, open-label, phase 2a study enrolled adults with C. difficile infection at 4 US centers. Patients received ibezapolstat 450 mg orally every 12 hours for 10 days and followed for an additional 28 days to assess study objectives.

Results

Ten patients with a mean (standard deviation [SD]) age of 49 [15] years were enrolled. Seven AEs were reported classified as mild-moderate. Plasma levels of ibezapolstat ranged from 233 to 578 ng/mL while mean (SD) fecal levels were 416 (494) µg/g stool by treatment day 3 and >1000 µg/g stool by days 8–10. A rapid increase in alpha diversity in the fecal microbiome was noted after starting ibezapolstat therapy, which was maintained after completion of therapy. A proportional decrease in Bacteroidetes phylum was observed (mean change [SD], −10.0% [4.8%]; P = .04) with a concomitantly increased proportion of Firmicutes phylum (+14.7% [5.4%]; P = .009). Compared with baseline, total primary bile acids decreased by a mean (SD) of 40.1 (9.6) ng/mg stool during therapy (P < .001) and 40.5 (14.1) ng/mg stool after completion of therapy (P = .007). Rates of both initial clinical cure and SCC at 28 days were 100% (10 of 10 patients).

Conclusions

In this phase 2a study, 10 of 10 patients achieved SCC, demonstrated favorable pharmacokinetics, minimal AEs, and beneficial microbiome and bile acids results. These results support continued clinical development.

1720. Isolation and Characterization of Candida auris From an Active Surveillance System in Texas

Background

Candida auris is an emerging new multi-drug-resistant fungal pathogen spreading globally. C. auris is associated with outbreaks due to the bloodstream, ear, and wound infections with a high mortality rate (30 to 60%). As part of our multi-pathogen surveillance system, we began screening for C. auris to understand the ecology, sources, and epidemiology of this important pathogen from leftover stool samples collected from hospitalized patients.

Methods

Four hundred and seventeen stool samples were collected, enriched in brain heart infusion broth for 2–3 days at 37°C, and sub-cultured onto selective Candida agar plates. Agar plates were incubated at 37°C for another 2–3 days and suspected Candida colonies were stocked for DNA extraction, PCR identification, and whole-genome sequencing. PCR amplicons were sequenced to confirm the identification C. auris. Enrichment samples were also screened by PCR to directly detect C. auris. Minimum inhibitory concentration (MIC) of various anti-fungal drugs was determined by the micro-dilution method using a commercial MIC plate (Sensititre “YeastOne”).

Results

Three C. auris samples were identified by PCR (0.7%; 3/417) of which one was able to be cultured. The isolated strain was resistant to fluconazole, itraconazole, voriconazole, posaconazole, and caspofungin. WGS data analysis demonstrates our isolate has high similarity with the Pakistani strains.

Conclusion

We have detected C. auris from stool samples of hospitalized patients in Texas for the first time. WGS data indicate our isolate has high similarity with South Asian patient strains. Long-term surveillance of C. auris is essential to understand the infection or colonization sources and epidemiology of this newly emerging fungal pathogen.

Disclosures

All authors: No reported disclosures.

2391. Increased Risk of Systemic Infections with Multidrug-Resistant Organisms in Patients with Severe Clostridioides difficile Infection

Background

The gut microbiota is a defense mechanism against colonization of multidrug-resistant organisms (MDROs), including carbapenem-resistant Enterobacteriacae (CRE). Gut dysbiosis caused by broad-spectrum antibiotics favors MDRO colonization and increased susceptibility of intestinal infections, including C. difficile infection (CDI). Increased CDI severity may increase the risk of bacterial translocation due to damage to colonic epithelial layer. The aim of this study was to assess CDI disease severity and subsequent risk for MDRO systemic infection.

Methods

This was a prospective, observational study of adult hospitalized patients tested for CDI at a large, university-affiliated tertiary care hospital. Patients with a history of systemic MDRO infection in the past 90-days of stool testing were excluded. Patients were stratified by test positivity (CDI vs. antibiotic-associated diarrhea (AAD)), as well as, CDI disease severity and followed for 30-days for subsequent MDRO infections defined as presence of MDRO cultures from systemic, normally sterile sites (blood, urine, cerebrospinal fluid). Stool samples were collected and grown for MDRO colonization.

Results

A total of 335 CDI-positive and 135 antibiotic-associated diarrhea (AAD) hospitalized patients were included. No differences were found in rates of MDRO colonization by test positivity or disease severity (overall 68% VRE, 53% Candida spp., 30.4% MRSA, and 1.8% CRE). Significantly more patients with severe CDI had higher rates of developing systemic MDROs compared with mild-moderate CDI and AAD (23.2%, n = 112 vs. 8.1%, n = 223 P < 0.001; vs. 11.9%, p = 0.018). Severe CDI was found to be an independent risk factor for subsequent systemic MDRO infection via logistic regression.

Conclusion

Severe CDI disease is associated with an increased risk of systemic MDRO infections.

Disclosures

All authors: No reported disclosures.

2410. Molecular Characteristics of Environmental Clostridioides difficile From a Large Texas Hospital

Background

Clostridioides difficile is an anaerobic spore-forming, toxin-producing Gram-positive bacillus listed by the CDC as an “urgent threat” pathogen. Epidemiologic studies using whole-genome sequencing (WGS) have found that genetically distinct lineages infections occur in hospitalized patients, in addition to the fact that C. difficile spores persist on hospital surfaces after disinfection. The purposes of this study were to isolate and characterize C. difficile from the environment of a large Texas hospital.

Methods

We collected 330 swab samples of hospital environmental surfaces using sterile cotton gauze. The samples were then anaerobically enriched in brain heart infusion broth for 48–72 hours and plated onto cycloserine–cefoxitin fructose agar (CCFA). Suspected colonies were then genetically characterized using PCR (for tcdA, tcdB, cdtA, cdtB and tpi genes) and genotyped using fluorescent PCR ribotyping techniques.

Results

A total of 90/330 (27.3%) environmental samples were culture positive for C. difficile, of which 75/90 (82.1%) tested were toxigenic C. difficile by the presence of tcdA, tcdB, cdtA or cdtB. A total of 16 distinct ribotypes were identified from 41 C. difficile isolates tested using a fluorescent-ribotyping method. The predominant ribotypes isolated were F078–126 (8/41), F002 (5/41), F106 (4/41), F255 (4/41), and F014-020 (3/41).

Conclusion

We found a diversity of C. difficile strain types in various hospital high-touch surface environment in addition to ribotype F027 and F078, suggesting the hospital environment a reservoir and significant source C. difficile infections.

Disclosures

All authors: No reported disclosures.

Molecular epidemiology of Clostridioides difficile in domestic dogs and zoo animals

Animals such as domestic dogs and zoo animals reside in close proximity to humans and could contribute to the dissemination of Clostridioides difficile spores which are common in the community environment. The purpose of this study was to assess C. difficile colonization in domestic dogs attending a day boarding facility and zoo animals receiving systemic antibiotics. Stool samples and paw swabs were collected from dogs who attended a day boarding facility. Stool samples were also collected from zoo animals starting systemic antibiotics. Finally, environmental samples were collected from nearby public parks. Stool samples and swabs were incubated anaerobically in enrichment broth for C. difficile growth, PCR was done to confirm presence of toxin genes, and PCR ribotyping was performed for strain characterization. During the study period, 136 dog stool samples were obtained, the paws of 16 dogs were swabbed, and 250 environmental swabs from surrounding public parks were obtained. Twenty-three of 136 dog stool samples (17%) and 9 of 16 dog paws sampled (56%) grew toxigenic C. difficile. One hundred and four stool samples from 49 zoo animals were collected of which 19 (18%) grew toxigenic C. difficile. Rates of toxigenic C. difficile colonization increased significantly during antibiotic therapy (33%) and then returned to baseline during the follow-up (11%) period (p = 0.019). Fifty-five of 250 environmental swabs from public parks (22%) grew toxigenic C. difficile. Ribotypes associated with human disease including 106 and 014-020 were isolated from all sources. This study demonstrated a high rate of toxigenic C. difficile colonization in domestic dogs and zoo animals with ribotypes similar to those causing human disease. These results demonstrate the relationship between humans, animals, and the environment in the dissemination of spores.

First Environmental Investigation of Toxigenic Clostridium difficile at a Large Hospital in Bangladesh

Background

Toxigenic Clostridium difficile is the most common cause of infectious diarrhea in hospitalized patients in the developed world and an emerging pathogen in developing countries due to increased use of broad-spectrum antibiotics. Although likely ubiquitous worldwide, the prevalence of toxigenic C. difficile spores in the hospital environs of developing countries is poorly understood. The objectives of the study are to isolate and characterize C. difficile from the hospital environs of a large hospitals in Dhaka, Bangladesh.

Methods

As part of our environmental surveillance effort, we collected 330 shoe-bottom swab samples from hospital employees, patients, and visitors inside of a large hospital in Dhaka, Bangladesh. Samples were analyzed for C. difficile using anaerobic enrichment culture and molecular methods. Suspected colonies from cycloserine cefoxitin fructose agar (CCFA) plates were identified by PCR (tcdA, tcdB, cdtA, cdtB and tpi genes) and strain typed using fluorescent PCR ribotyping, and MLVA methods.

Results

A total 149 of 333 (44.7%) shoe-bottom swab samples were culture positive for C. difficile of which 19.8% samples were toxigenic (tcdA and tcdB) C. difficile. A total of 11 distinct ribotypes were identified from 58 toxigenic C. difficile isolates tested. Predominant ribotypes were F053-163 (24.1%), F017 (20.7%), F106 (19.0%), F014-020 (17.2%). Other ribotypes were R001, F005, F010, F018, F054, F216, and FP407. No R027 and R078 C. difficile isolated. A broad MLVA diversity has been seen among the tested strains.

Conclusion

We identified a high prevalence of toxigenic C. difficile with diverse ribotypes from hospital environmental shoe-bottom swabs in Bangladesh. This is the first hospital environmental report of C. difficile from Bangladesh.

Disclosures

All authors: No reported disclosures.

A Practical Concussion Physical Examination Toolbox

CONTEXT

With heightened awareness of concussion, there is a need to assess and manage the concussed patient in a consistent manner. Unfortunately, concussion physical examination has not been standardized or supported by evidence. Important questions remain about the physical examination.

EVIDENCE ACQUISITION

Review of ClinicalKey, Cochrane, MEDLINE, and PubMed prior to July 2015 was performed using search terms, including concussion, mTBI, physical examination, mental status, cranial nerves, reflexes, cervical, vestibular, and oculomotor. The references of the pertinent articles were reviewed for other relevant sources.

STUDY DESIGN

Clinical review.

LEVEL OF EVIDENCE

Level 3.

RESULTS

The pertinent physical examination elements for concussion include evaluation of cranial nerves, manual muscle testing, and deep tendon reflexes; inspecting the head and neck for trauma or tenderness and cervical range of motion; Spurling maneuver; a static or dynamic balance assessment; screening ocular examination; and a mental status examination that includes orientation, immediate and delayed recall, concentration, mood, affect, insight, and judgment. Other examination elements to consider, based on signs, symptoms, or clinical suspicion, include testing of upper motor neurons, cervical strength and proprioception, coordination, pupillary reactivity, and visual acuity; examination of the jaw, temporomandibular joint, and thoracic spine; fundoscopic evaluation; orthostatic vital signs; assessment of dynamic visual acuity; and screening for depression, anxiety, substance abuse disorders, and preinjury psychiatric difficulties.

CONCLUSION

Various elements of the physical examination, such as screening ocular examination, cervical musculoskeletal examination, static and/or dynamic balance assessment, and mental status examination, appear to have utility for evaluating concussion; however, data on validity are lacking.

Advancements in Imaging Technology: Do They (or Will They) Equate to Advancements in Our Knowledge of Recovery in Whiplash?

Synopsis It is generally accepted that up to 50% of those with a whiplash injury following a motor vehicle collision will fail to fully recover. Twenty-five percent of these patients will demonstrate a markedly complex clinical picture that includes severe pain-related disability, sensory and motor disturbances, and psychological distress. A number of psychosocial factors have shown prognostic value for recovery following whiplash from a motor vehicle collision. To date, no management approach (eg, physical therapies, education, psychological interventions, or interdisciplinary strategies) for acute whiplash has positively influenced recovery rates. For many of the probable pathoanatomical lesions (eg, fracture, ligamentous rupture, disc injury), there remains a lack of available clinical tests for identifying their presence. Fractures, particularly at the craniovertebral and cervicothoracic junctions, may be radiographically occult. While high-resolution computed tomography scans can detect fractures, there remains a lack of prevalence data for fractures in this population. Conventional magnetic resonance imaging has not consistently revealed lesions in patients with acute or chronic whiplash, a "failure" that may be due to limitations in the resolution of available devices and the use of standard sequences. The technological evolution of imaging techniques and sequences eventually might provide greater resolution to reveal currently elusive anatomical lesions (or, perhaps more importantly, temporal changes in physiological responses to assumed lesions) in those patients at risk of poor recovery. Preliminary findings from 2 prospective cohort studies in 2 different countries suggest that this is so, as evidenced by changes to the structure of skeletal muscles in those who do not fully recover. In this clinical commentary, we will briefly introduce the available imaging decision rules and the current knowledge underlying the pathomechanics and pathophysiology of whiplash. We will then acknowledge known prognostic factors underlying functional recovery. Last, we will highlight emerging evidence regarding the pathobiology of muscle degeneration/regeneration, as well as advancements in neuroimaging and musculoskeletal imaging techniques (eg, functional magnetic resonance imaging, magnetization transfer imaging, spectroscopy, diffusion-weighted imaging) that may be used as noninvasive and objective complements to known prognostic factors associated with whiplash recovery, in particular, poor functional recovery. J Orthop Sports Phys Ther 2016;46(10):861-872. doi:10.2519/jospt.2016.6735.

Operational implementation of prospective genotyping for personalized medicine: the design of the Vanderbilt PREDICT project

The promise of "personalized medicine" guided by an understanding of each individual's genome has been fostered by increasingly powerful and economical methods to acquire clinically relevant information. We describe the operational implementation of prospective genotyping linked to an advanced clinical decision-support system to guide individualized health care in a large academic health center. This approach to personalized medicine entails engagement between patient and health-care provider, identification of relevant genetic variations for implementation, assay reliability, point-of-care decision support, and necessary institutional investments. In one year, approximately 3,000 patients, most of whom were scheduled for cardiac catheterization, were genotyped on a multiplexed platform that included genotyping for CYP2C19 variants that modulate response to the widely used antiplatelet drug clopidogrel. These data are deposited into the electronic medical record (EMR), and point-of-care decision support is deployed when clopidogrel is prescribed for those with variant genotypes. The establishment of programs such as this is a first step toward implementing and evaluating strategies for personalized medicine.

Dementia in people with Down's syndrome

OBJECTIVES

To determine the prevalence of dementia in an Irish sample of people with Down's syndrome (DS) and to examine associated clinical characteristics of dementia in this group.

METHOD

285 people with DS (Age 35-74 years, mean age +/- SD 46.5 +/- 8.2 years) were included in this cross-sectional study. The diagnosis of dementia was made using modified DSMIV criteria. Cognitive tests used were the Down's syndrome Mental Status Examination (DSMSE), Test for Severe Impairment (TSI) and adaptive function was measured by the Daily Living Skills Questionnaire (DLSQ).

RESULTS

The overall prevalence of dementia was 13.3%. The presence of dementia was associated with epilepsy, myoclonus, and head injury. The demented DS group were significantly older (n = 38, mean age 54.7 years SD +/- 7.5) than the non-demented (n = 246, mean age 45.6, SD +/- 7.3). The TSI and DLSQ had a satisfactory spread of scores without 'floor' or 'ceiling' effects in people with moderate and severe learning disability. Median scores in demented versus the non-demented groups were significantly different for each measure of function.

CONCLUSIONS

Dementia had a prevalence of 13.3% and occurred at a mean age of 54.7 years. The combination of DLSQ score, age and presence of epilepsy were found to predict presence of dementia.

The LN54 radiation hybrid map of zebrafish expressed sequences

To increase the density of a gene map of the zebrafish, Danio rerio, we have placed 3119 expressed sequence tags (ESTs) and cDNA sequences on the LN54 radiation hybrid (RH) panel. The ESTs and genes mapped here join 748 SSLp markers and 459 previously mapped genes and ESTs, bringing the total number of markers on the LN54 RH panel to 4226. Addition of these new markers brings the total LN54 map size to 14,372 cR, with 118 kb/cR. The distribution of ESTs according to linkage groups shows relatively little variation (minimum, 73; maximum, 201). This observation, combined with a relatively uniform size for zebrafish chromosomes, as previously indicated by karyotyping, indicates that there are no especially gene-rich or gene-poor chromosomes in this species. We developed an algorithm to provide a semiautomatic method for the selection of additional framework markers for the LN54 map. This algorithm increased the total number of framework markers to 1150 and permitted the mapping of a high percentage of sequences that could not be placed on a previous version of the LN54 map. The increased concentration of expressed sequences on the LN54 map of the zebrafish genome will facilitate the molecular characterization of mutations in this species.

A high-resolution map of human chromosome 12

Our sequence-tagged site-content map of chromosome 12 is now integrated with the whole-genome fingerprinting effort. It provides accurate and nearly complete bacterial clone coverage of chromosome 12. We propose that this integrated mapping protocol serves as a model for constructing physical maps for entire genomes.

Fast apple (Malus x domestica) and tobacco (Nicotiana tobacum) leaf polyphenol oxidase activity assay for screening transgenic plants

A spectrophotometric assay method for the analysis of polyphenol oxidase (PPO), in apple and tobacco leaves, has been optimized to increase efficiency in the screening of large numbers of transgenic plants. Crude protein extracts from leaf punches were prepared in a FastPrep homogenizer. The addition of Triton X-100 during extraction resulted in 44 and 74% increases in the PPO activity recovered, from apple and tobacco, respectively. The enzyme kinetics differed markedly between apple and tobacco. Apple leaf PPO was isolated in a latent state and was activated by the addition of SDS. In contrast, tobacco PPO activity was inhibited by SDS, particularly at acidic pH. Apple PPO showed a pronounced pH optimum around pH 6, whereas the pH profile for tobacco PPO was much flatter, with a broad optimum around pH 4. The calculated Km' value for apple PPO, using 4-methylcatechol as substrate, was 8.1, and for tobacco the Km was 4.3. The PPO reaction was strongly inhibited by tropolone, a Cu competitor, and restored by the addition of Cu2+. Several factors affecting variability in leaf PPO activity levels in plants are discussed.

Experience with continuous infusion of recombinant activated factor VII in the Asia-Pacific region

There is increasing interest in continuous infusion of recombinant activated factor VII (rFVIIa) as a convenient and safe alternative to intermittent bolus therapy. In the Australian patients reported in this paper, cost savings of up to 25% in the first 12 h of treatment with continuous infusion of rFVIIa have been achieved safely, suggesting that substantial overall savings are possible. However, in the Thai patient reported, a dose reduction of 35% in the first 12 h was associated with poor haemostatic control, suggesting that a dose reduction of >25% may be inadvisable. The indications for treatment in the five Australian patients were: retroperitoneal haemorrhage (n = 3); right forearm compartment syndrome (n = 1); wrist haemarthrosis and median nerve compression (n = 2); sublingual haematoma (n = 1); and cerebral (mid-brain) haemorrhage (n = 1). Treatment was effective in four out of five patients (six bleeding episodes) and there was one treatment failure where treatment had been substantially delayed. The Thai patient was treated as part of a prospective, uncontrolled, observational study of 34 bleeding episodes in 22 patients in the Asia-Pacific region. Treatment was judged ineffective after 24 h, but full haemostatic control was subsequently achieved with intermittent rFVIIa therapy.

The price of peace: the personal and financial cost of paramilitary punishments in Northern Ireland

The aim of this study was to compare the injuries sustained during paramilitary punishments both before and after the onset of "peace" in Northern Ireland. A retrospective chart review was performed looking at age, injuries, treatments instituted, theatre time, length of hospital stay and overall cost of care. In the 10-month period before the ceasefire, 31 patients were treated after sustaining paramilitary punishment shootings. Mean age was 25.2 years. All patients had small entrance and exit wounds with minimal soft tissue disruption. A total of 18 fractures were recorded in 15 patients and 14 arteries required repair. Mean operative time was 2.6 h, mean hospital stay 7.61 days and mean cost per patient 3102 Pounds. In the following 10-month period 28 patients were admitted after punishments, only one of whom had been shot, all others had been beaten with sticks and clubs. Mean age was 27.4 years. In 52 limbs, 64 fractures were recorded and 44% of these were open; 15 of the fractures were Gustilo and Anderson Grade III or greater and 11 of the fractures were intra-articular. There were no arterial injuries. Mean operative time was 2.6 h, mean hospital stay 12.4 h and mean cost per patient 3849 Pounds.

Presenilin 1 and alpha-1-antichymotrypsin polymorphisms in Down syndrome: no effect on the presence of dementia

As people with Down syndrome (DS) age, they are at greater risk for Alzheimer disease (AD) than the general population. It has been suggested that polymorphisms at the genes for presenilin-1 (PS-1) and alpha-1-antichymotrypsin (ACT) confer an increased risk for AD in the general population, and therefore potentially to AD in people with DS. We obtained DNA from 231 individuals with DS and 233 population controls. People with DS were evaluated for dementia. Allele frequencies at PS-1 and ACT polymorphisms in people with DS were compared to those in age-matched controls. There were no frequency differences between the control sample and DS sample for PS-1 or ACT alleles or genotypes. Similarly, there were no differences in allele frequencies between the demented and age-matched non-demented DS samples. However a higher frequency of PS-1 heterozygotes in the demented DS group was noted. We conclude that unlike the general population, neither PS-1 nor ACT polymorphisms appear to have a similar detrimental effect on dementia in DS. Am. J. Med. Genet. (Neuropsychiatr. Genet.) 88:616-620, 1999.

zA map for sequence analysis of the Arabidopsis thaliana genome

Arabidopsis thaliana has emerged as a model system for studies of plant genetics and development, and its genome has been targeted for sequencing by an international consortium (the Arabidopsis Genome Initiative; http://genome-www. stanford.edu/Arabidopsis/agi.html). To support the genome-sequencing effort, we fingerprinted more than 20,000 BACs (ref. 2) from two high-quality publicly available libraries, generating an estimated 17-fold redundant coverage of the genome, and used the fingerprints to nucleate assembly of the data by computer. Subsequent manual revision of the assemblies resulted in the incorporation of 19,661 fingerprinted BACs into 169 ordered sets of overlapping clones ('contigs'), each containing at least 3 clones. These contigs are ideal for parallel selection of BACs for large-scale sequencing and have supported the generation of more than 5.8 Mb of finished genome sequence submitted to GenBank; analysis of the sequence has confirmed the integrity of contigs constructed using this fingerprint data. Placement of contigs onto chromosomes can now be performed, and is being pursued by groups involved in both sequencing and positional cloning studies. To our knowledge, these data provide the first example of whole-genome random BAC fingerprint analysis of a eucaryote, and have provided a model essential to efforts aimed at generating similar databases of fingerprint contigs to support sequencing of other complex genomes, including that of human.

Type II fish antifreeze protein accumulation in transgenic tobacco does not confer frost resistance

Type II fish antifreeze protein (AFP) is active in both freezing point depression and the inhibition of ice recrystallization. This extensively disulfide-bonded 14 kDa protein was targeted for accumulation in its pro- and mature forms in the cytosol and apoplast of transgenic tobacco plants. Type II AFP gene constructs under control of a duplicate cauliflower mosaic virus 35S promoter, both with and without a native plant transit peptide sequence, were introduced into tobacco by Agrobacterium tumefaciens-mediated transformation. AFP did not accumulate in the cytosol of transgenic plants, but active AFP was present as 2% the total protein present in the apoplast. Plant-produced AFP was the same size as mature Type II AFP isolated from fish, and was comparable to wild-type AFP in thermal hysteresis activity and its effect on ice crystal morphology. Field trials conducted in late summer on R1 generation transgenic plants showed similar AFP accumulation in plants under field conditions at levels suitable for large-scale production: but no difference in frost resistance was observed between transgenic and wild-type plants during the onset of early fall frosts.

Education in informatics in medicine and the health sciences--the need for relevance

At the University of Newcastle, the 5-year undergraduate programme in Medicine has been developed as a problem-based, self-directed, fully integrated curriculum. Curricular integration involves not only the basic and clinical sciences, but also population medicine, critical reasoning and the development of a broad range of professional skills. Medical informatics has been seen as an increasingly important professional skill and the integrated nature of the curriculum has provided an appropriate setting for the introduction and continuing development of this component of the curriculum. Over the last 3 years this component has been developed to be incorporated into the curriculum for the health sciences within the faculty, becoming health informatics. Informatics for undergraduate students in medicine and allied health professions must be developed as a relevant and useful component of the curriculum.

A protective effect of apolipoprotein E e2 allele on dementia in Down's syndrome

BACKGROUND

The apolipoprotein E (ApoE) e4 allele has been associated with an increased risk for Alzheimer's disease, whereas the e2 allele has been shown to be protective. Similar effects in Down's syndrome (DS) have been postulated but not yet demonstrated.

METHODS

We obtained DNA from 221 DS individuals and from 162 population controls, and 77 DS children. Older DS subjects were evaluated for dementia and compared to age-matched DS controls.

RESULTS

The DS sample with dementia (n = 31) had a significantly lower frequency of the ApoE e2 allele compared to age-matched nondemented DS controls (0% vs. 8.3%, p = .0136). The older DS population had a significantly lower frequency of ApoE e4 compared to population controls (11.7% vs. 20.6%, chi-square 8.9, p = .0028).

CONCLUSIONS

The lower frequency of the e2 allele in demented DS subjects compared to age-matched nondemented DS controls suggests a protective effect for ApoE e2 in the development of dementia in DS. The lower frequency of ApoE e4 in our older DS sample compared to population controls points to a detrimental effect of the e4 allele on longevity.

Experiences with continuous infusion of recombinant activated factor VII

A questionnaire was sent to 28 haemophilia treatment centres known to have used recombinant activated factor VII (rFVIIa; NovoSeven, Novo Nordisk, Bagsvaerd, Denmark), to collect data on continuous infusion of this product. This mode of administration was recently introduced for rFVIIa but there are several questions which remain to be answered in order to optimize this technique. Of the 26 responding centres, 14 had used rFVIIa in continuous infusion for 40 treatment episodes over a total of 283 days. In most of the cases the treatment was targeted at a factor VII level of 10 IU/ml, monitored by the one-stage clotting assay. This seemed to be adequate for most of the haemorrhagic and surgical procedures. Pretreatment pharmacokinetic evaluation was performed in only a minority of the cases but is probably of great importance given the wide variation observed in the clearance values. A strategy was necessary to prevent local thrombophlebitis, at least for infusions in peripheral veins; parallel infusion of heparin, saline or dextrose-saline proved effective. The question of optimal monitoring needs further attention. Haemorrhagic complications were significantly less frequent when treatment was combined with the antifibrinolytic tranexamic acid.

Pro-haemorrhagic effects of calcium antagonists: a comparison of isradipine and atenolol on ex vivo platelet function in hypertensive subjects

It has been suggested that long term treatment with calcium antagonist drugs might inhibit platelet function and lead to an anti-atheromatous effect. However recent data have also suggested that such an effect might increase mortality due to an increased incidence of gastrointestinal bleeding. We identified 43 subjects from general practice with uncomplicated mild to moderate hypertension to compare the effects of the calcium antagonist isradipine with that of the beta-blocker atenolol on platelet function, plasma beta-thromboglobulin levels, fibrinolysis, and serum lipids in a randomised double-blind parallel group study. After careful evaluation to exclude concomitant aspirin use, only 24 subjects were eligible to enter the study. While isradipine and atenolol produced comparable and clinically significant falls in blood pressure (167 +/- 2/102 +/- 1 to 153 +/- 3/91 +/- 2 mm Hg, and 165 +/- 2/101 +/- 1 to 156 +/- 4/91 +/- 2 mm Hg, respectively), neither drug produced a detectable effect on ex vivo platelet aggregation, platelet retention, or thromboxane generation with adrenaline, collagen, adenosine-di-phosphate, or platelet activating factor. However a decrease in plasma beta-thromboglobulin levels was observed which reached statistical significance (P < 0.05) after 12 weeks treatment in the isradipine but not the atenolol group. A 39% reduction with isradipine compared with 34% following atenolol treatment. Euglobulin clot lysis time was not altered by either drug. Serum cholesterol concentrations were also unaltered by drug treatment. Therapeutic doses of the calcium antagonist isradipine may produce a minor indirect effect on platelet function after several weeks of treatment. However, this is of doubtful clinical importance and may simply reflect an effect of lowered blood pressure on platelet function.

Cross-reactivity to porcine factor VIII of factor VIII inhibitors in patients with haemophilia in Australia and New Zealand

BACKGROUND

Inhibitory antibodies which neutralise factor VIII develop in 10-20% of individuals with inherited haemophilia A and rarely as autoantibodies in normal individuals to cause acquired haemophilia. The antibodies are directed against human factor VIII but cross-react to varying degrees with porcine factor VIII. Porcine factor VIII can be used for treatment in individuals with low cross-reactivity.

AIMS

To determine the cross-reactivity of factor VIII inhibitors between human factor VIII and porcine factor VIII, in a population of patients with inherited and acquired haemophilia A. Also, to determine whether patients with inherited haemophilia and inhibitors have a higher incidence of factor VIII gene inversion in intron 22.

METHODS

Samples and data sheets from 43 patients with inherited and ten with acquired haemophilia were submitted from hospitals in Australia and New Zealand. Inhibitor levels to human and porcine factor VIII were measured by the Bethesda method in 39 with inherited and nine with acquired haemophilia A.

RESULTS

Of 39 patients with inherited haemophilia A, cross-reactivity was 0% in 17 patients, 1-19% in six, 20-39% in 11 and 40-80% in five. In six of nine patients with acquired haemophilia cross-reactivity was < or = 7%. In inherited severe haemophilia A, the frequency of the intron 22 inversion was not greater in 37 study patients than in 28 patients without an inhibitor.

CONCLUSIONS

Many patients in Australia and New Zealand with inhibitors to human factor VIII presently show a low or absent level of cross-reactivity to porcine factor VIII. These may respond to treatment with this concentrate at least in the short term. There remains a group of patients with high cross-reactivity who will respond only to recombinant factor VIIa or prothrombin complex concentrates.

Quantitation of vaginally administered nonoxynol-9 in premenopausal women

A feasibility study was performed in 11 healthy nonpregnant premenopausal women to determine a method for collection and recovery of vaginally administered nonoxynol-9. We also determined if nonoxynol-9 could be quantitated in vaginal lavage fluid obtained 2 h after instillation of a standard precoitol dose of a foam formulation of nonoxynol-9. Samples were analyzed in batch using a validated normal phase high-performance liquid chromatography (HPLC) method. Two hours after instillation of one dose of Delfen Contraceptive Foam (100 mg), the quantity of nonoxynol-9 collected ranged from 10.8 to 67.8 mg (mean: 35.4 mg). This corresponds to a recovery of 11.70%, of the administered dose. Quantitation of vaginally administered nonoxynol-9 is both practical and feasible. These data represent a critical first step in the evaluation of the safety and effectiveness of nonoxynol-9-containing products in the prevention of sexually transmitted diseases.

Pre-activating wounding response in tobacco prior to high-level ozone exposure prevents necrotic injury

In tobacco, both wounding and treatment with jasmonates prior to exposure of the tissue to high concentrations of ozone (250 to 500 p.p.b.) produce a dramatic decrease in ozone injury. A systemic pattern of increased ozone tolerance developed within 3-6 h after wounding and also after local application of jasmonates. Ozone treatment of transgenic (NahG) tobacco plants showed that the inability of these plants to accumulate salicylic acid is also accompanied by increased ozone tolerance. Expression of mRNA encoding the anti-oxidant enzyme ascorbate peroxidase is upregulated by ozone challenge, wounding and by methyl jasmonate exposure within 3-4 h, while levels of carbonic anhydrase mRNA are simultaneously depressed following ozone exposure and methyl jasmonate treatment. The pattern of these results shows that the response to ozone challenge in tobacco involves signalling mechanisms similar to those induced in plants by other environmental stresses that generate reactive oxygen species.

Pseudomonas putida B2: a tod-lux bioluminescent reporter for toluene and trichloroethylene co-metabolism

A tod-lux transcriptional fusion bioluminescent reporter strain, Pseudomonas putida B2, was developed to permit on-line analysis of trichloroethylene (TCE) transformation by toluene dioxygenase (todC1C2BA) in Pseudomonas putida F1. Strain B2 was exposed to toluene in growing and resting cell bioluminescence assays. The growing cells showed a direct correlation between bioluminescence and toluene concentration, while resting cells showed reproducible bioluminescence with repeated toluene exposures. In addition, P. putida B2 was encapsulated in alginate beads and used in a packed bed flow-through differential volume reactor. The TCE feed into the differential volume reactor was constant at 20 mg L-1 and toluene was pulsed in square-wave perturbations at 10 mg L-1. The system showed a direct correlation between the expression of the tod operon (as monitored by light output) and the co-metabolism of TCE. Approximately 20% of the TCE and 50% of the toluene was removed at a flow rate of 0.4 ml min-1. This approach allowed the on-line monitoring of tod gene expression and its relation to TCE biotransformation.

Topically applied recombinant tissue plasminogen activator for the treatment of venous ulcers. Preliminary report

BACKGROUND

Increasing evidence suggests that fibrin deposition is an important pathogenic component of venous ulceration and that fibrin removal could accelerate ulcer healing.

OBJECTIVE

We sought to determine whether topical application of recombinant tissue plasminogen activator (tPA) compounded in 1% hyaluronate acid (HA) can be used safely in venous ulcers and whether it can accelerate healing.

METHODS

Twelve patients were randomized in a double-blind fashion in three sequential groups of four subjects each, so as to receive daily topical application of either placebo (HA alone, one patient) or tPA/HA (three patients) at escalating doses of 0.25, 0.5, and 1.0 mg/ml of tPA for 4 weeks.

RESULTS

No safety problems occurred, and we found a close direct correlation between mean ulcer reepithelialization, fibrin removal, and the dose of topically applied tPA (r = 0.991).

CONCLUSION

In this first study to examine its usefulness, topically applied tPA appears to be a safe and promising agent for treating venous ulcers.

The generation and regional localization of 303 new chromosome 5 sequence-tagged sites

With the ultimate goal of creating a sequence-ready physical map of all of chromosome 5, 303 new human chromosome 5-specific STS markers have been systematically generated and regionally ordered. Chromosome 5 DNA prepared from flow-sorted chromosomes was digested with restriction enzymes BamHI and HindIII and cloned in bacteriophage M13mp18. Random clones were sequenced, and appropriate PCR deoxyoligomers were synthesized. An acceptable sequence-tagged site (STS)-PCR assay yielded the appropriate size amplification product from both total human DNA and hybrid cell line DNA containing only human chromosome 5. Each STS has been regionally localized by breakpoint analysis using a set of hybrid cell panels consisting of natural deletions or translocations of human chromosome 5. This hybrid cell panel was able to localize the STSs to 1 of 51 bins on the short arm and 1 of 15 bins on the long arm. The STS markers appear to be randomly distributed along the length of this 194-Mb chromosome. The current overall density of these markers (approximately 1 STS/640 kb), combined with the numerous PCR-based physical and genetic markers generated by other groups, will provide sufficient "nucleation points" for YAC contig assembly and verification in any region of human chromosome 5.

Major surgery in haemophilic patients with inhibitors using recombinant factor VIIa

In the haemophilic patient, development of antibodies that inhibit the function of the missing coagulation factor causes several delicate problems. Most importantly, antibodies will block the function of the specific coagulation factor, and often the antibody activity is so fierce that effective substitution therapy is outruled. In consequence, alternative measures must be adopted to control bleeding. Amongst those most commonly employed, like factor IX concentrates, activated prothrombin complex concentrates, and factor VIII of porcine origin, a new recombinant activated factor VII molecule has been evaluated clinically for some years with promising results. The aim of the present paper was to present a series of patients suffering from haemophilia A or B in whom inhibitors have complicated the clinical picture, and in whom a surgical procedure was indicated. As part of a compassionate use program devised by the producer of this genetically engineered factor VIIa, 12 patients underwent life-saving or essential surgery where the recombinant factor VIIa product was used to promote haemostasis in 13 surgical procedures. Due to a short in vivo half-life of activated factor VIIa, frequent administration was scheduled, injecting factor VIIa every 2-3 h for up to 2 days after which dosage intervals were prolonged. In one case, a global evaluation of the end treatment result was not reported, but in all of the other 12 cases the end result were considered excellent (n = 11) or efficient (n = 1). In none of the cases was other types of coagulation factor treatment modalities necessary. In conclusion, recombinant factor VIIa seems a tempting alternative to traditional treatment of the haemophilic patient with inhibitors, in whom surgery is called for. With other types of haemostatic agents, surgery in haemophilic inhibitor patients has only been studied rarely, and operations have generally been restricted to life-threatening situations.

Experience with recombinant factor VIIa in Australia and New Zealand

Recombinant factor VIIa (rFVIIa; NovoSeventrademark) was availablefor compassionate use in Australia and New Zealand from 1991 to 1994. Over this period there were 18 treatment episodes in 9 patients, age 8-66 years, with haemophilia A and high titre inhibitors cross-reacting with porcine factor VIII. There were no significant adverse effects. Treatment with rFVIIa resulted in a successful outcome in 8 potentially life-threatening (retroperitoneal, subdural, gastro-intestinal) bleeds. Elective cystoscopy, repair of a cranial flap, yttrium synovectomy and inguinal herniotomy were performed successfully, as was surgical decompression of a flexor pollicis longus bleed. Treatment of a patient with an infected haematoma had limited success, attributed to intermittent suboptimal doses. In 2 patients, satisfactory haemostasis was achieved for multiple dental extractions; subsequent oozing was attributed to suboptimal rFVIIa and/or antifibrinolytic therapy.

Hypertensive and normal pregnancy: a longitudinal study of blood pressure, distensibility of dorsal hand veins and the ratio of the stable metabolites of thromboxane A2 and prostacyclin in plasma

OBJECTIVE

By combining serial measurements of the circulating concentrations of thromboxane A2 and prostacyclin with measurements of venous distensibility (taken during the pregnancies of both normal women and those with pregnancy induced hypertension or pre-eclampsia), to test the following hypotheses: 1. that changes in the venous plasma ratio of thromboxane (TXB2) and 6-keto-PGF1 alpha would correlate with changes in the blood pressure of women developing and recovering from pregnancy induced hypertension or pre-eclampsia and 2. that changes in venous distensibility would correlate with changes in arterial blood pressure in pregnancy induced hypertension or pre-eclampsia.

DESIGN

Prospective, longitudinal cohort study.

SETTING

John Hunter Hospital clinic, Newcastle, Australia.

SUBJECTS

One hundred and sixty primiparous women, recruited when presenting for their first routine antenatal visit, were investigated at, or close to, 19, 28 and 37 weeks of gestation; a subgroup was also studied in the postnatal period. The measurements of the patients who developed pregnancy induced hypertension or pre-eclampsia were compared with those of controls selected from the cohort.

MAIN OUTCOME MEASURES

Serial measurements of the circulating concentrations of the stable metabolites of thromboxane A2 and prostacyclin (TXB2 and 6-keto-PGF1 alpha, respectively), venous distensibility and immediate (no rest) and resting (for at least 30 min) blood pressures.

RESULTS

There was no significant difference between the subject and control groups at any time during or after the pregnancy in the concentrations of prostaglandin metabolites, their ratio or venous distensibility. In contrast, there was a significant difference between the groups at 19 weeks for immediate and resting readings of diastolic pressure (6 mmHg (95% CI 1.5 to 10.5) and 4 mmHg (95% CI 0.1 to 7.9), respectively). These differences increased through the pregnancy but mean postnatal readings for the groups were almost identical suggesting that the subjects were not intrinsically hypertensive compared with controls. Blood pressures for the subject group, both immediate and resting, were significantly different from the 19 week readings at 28 weeks (diastolic) and at 37 weeks (systolic and diastolic). The only significant change from first readings among controls was in postnatal systolic pressure which was significantly higher than 19 week values, probably reflecting the vasodilatation, with accompanying hypotension, of early, normal pregnancy. This difference was not observed in those who subsequently developed pregnancy induced hypertension or pre-eclampsia.

CONCLUSIONS

Our study was unable to demonstrate differences in circulating metabolites or venous distensibility between normotensive women and those with pregnancy induced hypertension or pre-eclampsia. If pregnancy induced hypertension or pre-eclampsia in humans represents not so much the presence of abnormal constrictor influences as a process initiated by failure of normal vasodilatation in early pregnancy, studies carried out later may detect mainly adaptive and secondary changes.

Psychomotor seizures of temporal lobe onset: analysis of symptom clusters and sequences

We analyzed 91 psychomotor seizures from 31 patients seizure free at least one year after temporal lobectomy (implying temporal lobe onset). Fifty symptoms were looked for in every seizure and their time of onset and ending noted. Statistical analysis was used to define symptom clusters and the order of appearance of symptoms. Of the eighteen most common symptoms examined, all of these symptoms form a tight cluster showing a high degree of correlation. Within this cluster, there was a tendency towards the following subclusters: (a) epigastric aura, ictal vomiting, alimentary and hand automatisms; (b) behavioral arrest, complete loss of consciousness, staring and bilateral facial contraction; (c) unilateral dystonic posturing of an arm, mimetic automatisms, complex gestures, ictal speech and partial loss of consciousness; (d) looking around, agitation, vocalizations and whole body movements. We also found a strong correlation between epigastric sensation and ictal vomiting in psychomotor seizures arising from the right but not the left temporal lobe. The commonest sequence of symptoms was: behavioral arrest followed by alimentary and hand automatisms, looking around and whole body movements, in that order.

Use of genetic and physical mapping to locate the spinal muscular atrophy locus between two new highly polymorphic DNA markers

The gene for autosomal recessive forms of spinal muscular atrophy (SMA) has recently been mapped to chromosome 5q13, within a 4-cM region between the blocks D5S465/D5S125 and MAP-1B/D5S112. We identified two new highly polymorphic microsatellite DNA markers--namely, AFM265wf5 (D5S629) and AFM281yh9 (D5S637)--which are the closest markers to the SMA locus. Multilocus analysis by the location-score method was used to establish the best estimate of the SMA gene location. Our data suggest that the most likely location for SMA is between locus D5S629 and the block D5S637/D5S351/MAP-1B/D5S112/D5S357. Genetic analysis of inbred SMA families, based on homozygosity by descent and physical mapping using mega-YACs, gave additional information for the loci order as follows: cen-D5S6-D5S125/D5S465-D5S435-D5S629-SMA-+ ++D5S637-D5S351-MAP-1B/D5S112-D5S357- D5S39-tel. These data give the direction for bidirectional walking in order to clone this interval and isolate the SMA gene.