Three wound-dressing strategies to reduce surgical site infection after abdominal surgery: the Bluebelle feasibility study and pilot RCT.

BACKGROUND: Surgical site infection (SSI) affects up to 20% of people with a primary closed wound after surgery. Wound dressings may reduce SSI. OBJECTIVE: To assess the feasibility of a multicentre randomised controlled trial (RCT) to evaluate the effectiveness and cost-effectiveness of dressing types or no dressing to reduce SSI in primary surgical wounds. DESIGN: Phase A - semistructured interviews, outcome measure development, practice survey, literature reviews and value-of-information analysis. Phase B - pilot RCT with qualitative research and questionnaire validation. Patients and the public were involved. SETTING: Usual NHS care. PARTICIPANTS: Patients undergoing elective/non-elective abdominal surgery, including caesarean section. INTERVENTIONS: Phase A - none. Phase B - simple dressing, glue-as-a-dressing (tissue adhesive) or 'no dressing'. MAIN OUTCOME MEASURES: Phase A - pilot RCT design; SSI, patient experience and wound management questionnaires; dressing practices; and value-of-information of a RCT. Phase B - participants screened, proportions consented/randomised; acceptability of interventions; adherence; retention; validity and reliability of SSI measure; and cost drivers. DATA SOURCES: Phase A - interviews with patients and health-care professionals (HCPs), narrative data from published RCTs and data about dressing practices. Phase B - participants and HCPs in five hospitals. RESULTS: Phase A - we interviewed 102 participants. HCPs interpreted 'dressing' variably and reported using available products. HCPs suggested practical/clinical reasons for dressing use, acknowledged the weak evidence base and felt that a RCT including a 'no dressing' group was acceptable. A survey showed that 68% of 1769 wounds (727 participants) had simple dressings and 27% had glue-as-a-dressing. Dressings were used similarly in elective and non-elective surgery. The SSI questionnaire was developed from a content analysis of existing SSI tools and interviews, yielding 19 domains and 16 items. A main RCT would be valuable to the NHS at a willingness to pay of £20,000 per quality-adjusted life-year. Phase B - from 4 March 2016 to 30 November 2016, we approached 862 patients for the pilot RCT; 81.1% were eligible, 59.4% consented and 394 were randomised (simple, n = 133; glue, n = 129; no dressing, n = 132); non-adherence was 3 out of 133, 8 out of 129 and 20 out of 132, respectively. SSI occurred in 51 out of 281 participants. We interviewed 55 participants. All dressing strategies were acceptable to stakeholders, with no indication that adherence was problematic. Adherence aids and patients' understanding of their allocated dressing appeared to be key. The SSI questionnaire response rate overall was 67.2%. Items in the SSI questionnaire fitted a single scale, which had good reliability (test-retest and Cronbach's alpha of > 0.7) and diagnostic accuracy (c-statistic = 0.906). The key cost drivers were hospital appointments, dressings and redressings, use of new medicines and primary care appointments. LIMITATIONS: Multiple activities, often in parallel, were challenging to co-ordinate. An amendment took 4 months, restricting recruitment to the pilot RCT. Only 67% of participants completed the SSI questionnaire. We could not implement photography in theatres. CONCLUSIONS: A main RCT of dressing strategies is feasible and would be valuable to the NHS. The SSI questionnaire is sufficiently accurate to be used as the primary outcome. A main trial with three groups (as in the pilot) would be valuable to the NHS, using a primary outcome of SSI at discharge and patient-reported SSI symptoms at 4-8 weeks. TRIAL REGISTRATION: Phase A - Current Controlled Trials ISRCTN06792113; Phase B - Current Controlled Trials ISRCTN49328913. FUNDING: This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 23, No. 39. See the NIHR Journals Library website for further project information. Funding was also provided by the Medical Research Council ConDuCT-II Hub (reference number MR/K025643/1).

Wound infections are common after surgery. Some are cured with simple treatment, but others may lead to serious problems. Reducing the risk of a wound infection is important. We do not know if the type of dressing, or not using a dressing, influences the risk of infection. A study that allocated patients to receive different dressings (or no dressing) would answer this question. We did preliminary research to explore whether or not such a study is possible. We interviewed doctors, nurses and patients about their views on dressings and a future study. We also described dressings currently being used in the NHS and found that simple dressings and tissue adhesive (glue) 'as-a-dressing' are used most frequently. We studied existing evidence and interviewed experts to develop a questionnaire, completed by patients, to identify wound infections after patients leave hospital and tested its accuracy. We also explored taking photographs of wounds. We investigated whether or not a major study would be worth the cost and designed a pilot study to test its feasibility. The pilot study recruited 394 patients undergoing abdominal operations in five NHS hospitals. These patients were allocated to have a simple dressing, glue-as-a-dressing or no dressing, and 92% received the allocated dressing method. Patients and their doctors and nurses found the dressing methods to be acceptable. We showed that the new patient questionnaire accurately identified infections. Patients or their carers also found it acceptable to photograph their wounds. Our research suggests that a future large study would be worth the investment and is possible.

Improvement in obstructive sleep apnea diagnosis and management wait times: A retrospective analysis of home management pathway for obstructive sleep apnea.

Obstructive sleep apnea is a common condition within the Canadian population. The current gold standard for diagnosis and management of patients is in-laboratory (in-lab) polysomnography; however, the limited availability of testing options for patients has led to long wait times and increased disease burden within the population. The Sleep Research Laboratory in Saskatoon (Saskatchewan) implemented a home management program to run in parallel with the in-lab system several years ago in an effort to increase their capacity and reduce wait times. The present study was a retrospective analysis of all patients referred to the program between 2009 and 2012. The home management system has improved wait times by diagnosing and managing up to one-half of the referred patient population, reducing the wait for in-lab treatment from a median of 152 days in 2009 to 92 days in 2012 (P<0.0001). Moving forward, home management can provide a viable alternative to in-lab testing for patients who meet strict entry criteria, reducing the in-lab workload and, ultimately, reducing wait times.

The utility of the elbow sign in the diagnosis of OSA.

BACKGROUND: Multiple questionnaires have been used to predict the diagnosis of OSA. Such models typically have multiple questions requiring cumulative scoring for interpretation. We wanted to determine whether a simple two-part questionnaire has predictive value in the pretest clinical evaluation for OSA. METHODS: A questionnaire consisting of two questions--(1) Does your bed partner ever poke or elbow you because you are snoring? and (2) Does your bed partner ever poke or elbow you because you have stopped breathing?--was prospectively administered to patients evaluated in a sleep disorders clinic prior to undergoing polysomnography. Age, sex, BMI, and Epworth Sleepiness Scale data were collected. RESULTS: Among the 128 patients who had a polysomnogram, answering "yes" to being awakened for snoring increased the OR of an apnea-hypopnea index≥5/h 3.9 times compared with "no." Answering "yes" to being awakened for apneic spells was associated with an OR of 5.8 for an apnea-hypopnea index≥5/h compared with "no." These associations did not differ by sex, BMI, Epworth Sleepiness Scale or answering "yes" to the other question. Subjects>50 years old with OSA were less likely to report a positive elbow sign and had a significantly lower OR for being awakened for apneic spells than those<50 years old. The sensitivity and specificity of being awakened for apneic spells was 65% and 76%, respectively, with a positive predictive value of 90%. Subgroup analysis revealed that in men with a BMI>31 a positive elbow sign had a specificity of 96.6% for a diagnosis of OSA. CONCLUSIONS: Among patients referred to a sleep disorders clinic, a positive response to being elbowed/poked for apneic spells significantly improves the pretest prediction of OSA.

Inter-observer reliability of candidate predictive morphometric measurements for women with suspected obstructive sleep apnea.

OBJECTIVE: Obstructive sleep apnea (OSA) is increasingly recognized as a public health concern. Definitive diagnosis is by overnight polysomnographic (PSG) examination. Identification of clinical predictors would be beneficial in helping prioritize high-risk patients for assessment. Practical application of morphometric predictive variables would require a high level of reproducibility in a clinical setting. In this study, our objective was to evaluate reliability between observers in measurements of candidate morphometric parameters in women. DESIGN AND METHODS: This was a prospective study of 71 women who had been referred for PSG with suspected OSA. Selected morphometric parameters were measured independently in the sleep laboratory by two trained sleep physicians. RESULTS: Neck circumference and truncal measurements for lower costal, midabdominal, and hip circumferences had higher reliability coefficients (intraclass correlation coefficients [ICC] of 0.78, 0.95, 0.95, and 0.81) than the smaller dimension measurements, including cricomental distance or retrognathia (ICC of 0.04 and 0.17). Of the women participating in this study, 50 of 71 had apnea-hypopnea indexes (AHI) ≥ 5. Body mass index (BMI), neck circumference, lower costal girth, midabdominal girth, and hip girth were all significantly higher (p < 0.001-0.004) in women with AHI ≥ 5. CONCLUSIONS: There was wide variation in inter-observer reliability for different physical dimensions. We propose that any clinical morphologic measurement employed in predictive modeling should be reliably reproducible in clinical setting conditions. Our findings support the use of several truncal measures, BMI, and neck circumference as predictive measures in women undergoing evaluation for OSA.

Sleep disordered breathing and gestational hypertension: postpartum follow-up study.

BACKGROUND: Gestational hypertension (GH) is a newly recognized risk factor for adverse cardiovascular events later in life. Sleep disordered breathing (SDB) is an established risk factor for adverse cardiovascular events. Recent research has suggested that women with GH may have an increased rate of SDB during pregnancy, but it is not known if this higher rate of SDB persists into the postpartum state. OBJECTIVE: To assess whether women with GH continue to have an increased rate of SDB compared to healthy pregnant women, after the physiologic changes of pregnancy resolve. METHODS: We previously studied women with GH and uncomplicated pregnancies with sleep questionnaires and level 1 polysomnography. Participants were invited to participate in repeat testing 1-2 years postpartum. Respiratory disturbance index (RDI) differences were assessed. RESULTS: Eighteen subjects (11 GH and 7 healthy) had complete follow-up data available for comparison with antepartum data. This group was representative of the initial antepartum cohort. Women with GH experienced a decrease in mean RDI from antepartum to postpartum (12.0 ± 12.3 vs. 2.9 ± 2.9; P = 0.02). Healthy women did not experience the same change (2.8 ± 5.3 vs. 2.1 ± 3.2; P = 0.81). Postpartum comparisons showed the mean RDI of women with GH had decreased to be similar to that of healthy women (P = 0.75). CONCLUSIONS: SDB in women with gestational hypertension improved in the postpartum state to levels indistinguishable from our healthy subjects. This suggests that the physiologic effects of pregnancy may have had a pathologic role in the development of antepartum SDB in women with GH.

Can gestational hypertension be modified by treating nocturnal airflow limitation?

OBJECTIVE: Recent evidence suggests that women with gestational hypertension (GH) have a high rate of sleep disordered breathing (SDB), and treatment for even marginal SDB may improve blood pressure control in women with GH. We assessed whether the application SDB treatment could improve blood pressure in women with GH. METHODS: This was a single-center randomized study. Subjects underwent an unattended home-based diagnostic sleep study. The study was then repeated with subjects wearing one of two randomly assigned treatments: auto-titrating continuous positive airway pressure (auto-CPAP) or mandibular advancement device (MAD) + nasal strip. First morning blood pressure and blood for standard GH measures plus inflammatory markers were taken after each study. Subjects completed a series of questionnaires addressing sleep quality and tolerance of assigned therapy. RESULTS: Twenty-four women completed the protocol-13 in the MAD group and 11 in auto-CPAP. The overall rate of SDB was 38%. Auto-CPAP was more effective at treating SDB than MAD + nasal strip, although the women randomized to MAD + nasal strip reported the greater comfort with therapy. First morning blood pressure was not consistently improved with either therapy. When subjects were stratified according to those whose blood pressure increased or decreased with therapy, an association was suggested between blood pressure improvement and reduced levels of tumour necrosis factor-α. CONCLUSION: We demonstrated that 38% of women with GH had concurrent SDB. We did not find an improvement in blood pressure or inflammatory markers with a single night of either the auto-CPAP or MAD + nasal strip interventions. However important lessons from this study may guide future investigations in this area.

Pregnant women with gestational hypertension may have a high frequency of sleep disordered breathing.

BACKGROUND: Gestational hypertension is a common complication of pregnancy. Recent evidence suggests that women with gestational hypertension have a high rate of sleep disordered breathing (SDB). Using laboratory-based polysomnography, we evaluated for the frequency of SDB in women with gestational hypertension compared to healthy women with uncomplicated pregnancies. METHODS: In this single-center cross-sectional study, women with the diagnosis of gestational hypertension were screened in the Fetal Assessment Unit and Antepartum ward. Healthy subjects were recruited by local advertising. Subjects completed a series of questionnaires addressing sleep quality and daytime sleepiness, followed by full night polysomnography. The primary outcome was frequency of SDB (defined as a respiratory disturbance index ≥ 5) in the gestational hypertension and healthy groups. RESULTS: A total of 34 women with gestational hypertension and singleton pregnancies and 26 healthy women with uncomplicated singleton pregnancies consented to participate in the study. The mean ages and gestational ages, but not the body mass indices, of the 2 groups were similar. The frequencies of SDB in the more obese gestational hypertension group and the healthy group were 53% and 12%, respectively (P < 0.001). INTERPRETATION: Women with gestational hypertension may have a significantly higher frequency of SDB than do healthy women with uncomplicated pregnancies of similar gestational age. The relative causal contributions, if any, of SDB and obesity remain to be determined.

Circulating angiogenic and antiangiogenic factors in women with eclampsia.

OBJECTIVE: The objective of the study was to determine whether eclampsia has a different circulating profile of angiogenic (placental growth factor [PlGF]) and antiangiogenic factors (soluble vascular endothelial growth factor receptor-1 [sVEGFR-1] and soluble endoglin [sEng]) from severe preeclampsia. STUDY DESIGN: This cross-sectional study included pregnant women in the following groups: (1) normal pregnancy (n = 40); (2) severe preeclampsia (n = 40); and (3) eclampsia (n = 20). Maternal serum PlGF, sVEGFR-1, and sEng concentrations were determined using an enzyme-linked immunosorbent assay. RESULTS: The study results included the following: (1) the median concentration of sVEGFR-1 and sEng was higher and of PlGF was lower in severe preeclampsia or eclampsia than in normal pregnancy (P < .001 for all); and (2) the median concentrations of these 3 analytes did not differ significantly between patients with severe preeclampsia and those with eclampsia. CONCLUSION: Eclampsia is associated with higher maternal circulating concentrations of sVEGFR-1 and sEng and lower concentrations of PlGF than normal pregnancy but with similar concentrations to severe preeclampsia. These findings suggest that eclampsia shares a common pathogenic pathway as severe preeclampsia.

Evaluability assessment to improve public health policies, programs, and practices.

Evaluability assessment, also commonly known as exploratory evaluation, has assisted the field of public health to improve programs and to develop a pragmatic, practice-based research agenda. Evaluability assessment was originally developed as a low-cost pre-evaluation activity to prepare better for conventional evaluations of programs, practices, and some policies. For public health programs, however, it serves several other important purposes: (a) giving program staff rapid, constructive feedback about program operations; (b) assisting the core public health planning and assurance functions by helping to develop realistic objectives and providing low-cost, rapid feedback on implementation; (c) navigating federal performance measurement requirements; (d) translating research into practice by examining the feasibility, acceptability, and adaptation of evidence-based practices in new settings and populations; and (e) translating practice into research by identifying promising new approaches to achieve public health goals.

Outcomes of home-based diagnosis and treatment of obstructive sleep apnea.

BACKGROUND: Home diagnosis and therapy for obstructive sleep apnea (OSA) may improve access to testing and continuous positive airway pressure (CPAP) treatment. We compared subjective sleepiness, sleep quality, quality of life, BP, and CPAP adherence after 4 weeks of CPAP therapy in subjects in whom OSA was diagnosed and treated at home and in those evaluated in the sleep laboratory. METHODS: A randomized trial was performed consisting of home-based level 3 testing followed by 1 week of auto-CPAP and fixed-pressure CPAP based on the 95% pressure derived from the auto-CPAP device, and in-laboratory polysomnography (PSG) (using mostly split-night protocol) with CPAP titration; 102 subjects were randomized (age, 47.4 +/- 11.4 years; 63 men; BMI, 32.3 +/- 6.3 kg/m(2); Epworth Sleepiness Scale [ESS]: 12.5 +/- 4.3). The outcome measures were daytime sleepiness (ESS), sleep quality (Pittsburgh Sleep Quality Index [PSQI]), quality of life (Calgary Sleep Apnea Quality of Life Index [SAQLI], 36-Item Short-Form Health Survey [SF-36], BP, and CPAP adherence after 4 weeks. RESULTS: After 4 weeks of CPAP therapy, there were no significant differences in ESS (PSG 6.4 +/- 3.8 vs home monitoring [HM] 6.5 +/- 3.8, P = .71), PSQI (PSG 5.4 +/- 3.1 vs HM 6.2 +/- 3.4, P = .30), SAQLI (PSG 4.5 +/- 1.1 vs HM 4.6 +/- 1.1, P = .85), SF-36 vitality (PSG 62.2 +/- 23.3 vs HM 64.1 +/- 18.4, P = .79), SF-36 HM (PSG 84.0 +/- 10.4 vs HM 81.3 +/- 14.9, P = .39), and BP (PSG 129/84 +/- 11/0 vs HM 125/81 +/- 13/9, P = .121). There was no difference in CPAP adherence (PSG 5.6 +/- 1.7 h/night vs HM 5.4 +/- 1.0 h/night, P = .49). CONCLUSIONS: Compared with the home-based protocol, diagnosis and treatment of OSA in the sleep laboratory does not lead to superior 4-week outcomes in sleepiness scores, sleep quality, quality of life, BP, and CPAP adherence. TRIAL REGISTRATION: clinicaltrials.gov; Identifier: NCT00139022.

An empirical continuous positive airway pressure trial for suspected obstructive sleep apnea.

BACKGROUND: Standard practice in obstructive sleep apnea (OSA) management requires that a positive diagnostic, overnight polysomnography (PSG) test be obtained before initiating treatment. However, long waiting times due to lack of access to PSG testing facilities may delay the initiation of definitive treatment for OSA. OBJECTIVES: To evaluate the response of patients who had a high clinical suspicion for OSA and who were waiting for a PSG test to an empirical continuous positive airway pressure (CPAP) trial. METHODS: A retrospective study of all patients who had been offered empirical CPAP therapy for suspected OSA was conducted. After outpatient assessment, 183 patients with a high pretest probability of having OSA began empirical CPAP testing using an arbitrary CPAP pressure. The presence of OSA, the accuracy of empirical CPAP pressure prescription, the adherence to empirical CPAP and the improvement in daytime somnolence were evaluated at the time of PSG. RESULTS: Of 183 patients on a CPAP trial, 91% had OSA, which was at least moderate (more than 15 apneas and hypopneas per hour of sleep) in 75% of the patients. Eighty per cent of the patients had significant daytime somnolence (Epworth Sleepiness Scale [ESS] greater than 10, mean +/- SD ESS 14+/-5), which improved with CPAP (ESS 9.0+/-5, P<0.01). In 40% of the patients, the arbitrary CPAP pressure was lower than that determined by manual titration. Adherence to a trial of CPAP (longer than 2 h/night) predicted OSA with a sensitivity of 82% and a specificity of 41%; the positive and negative predictive values were 92% and 22%, respectively. CONCLUSIONS: At the time of PSG testing, OSA was present in 91% of the patients who had received empirical CPAP. An empirical CPAP provided satisfactory interim treatment for excessive somnolence, despite the fact that the CPAP pressure was suboptimal in 40% of the patients.

Targeted access to the genomes of low-abundance organisms in complex microbial communities.

Current metagenomic approaches to the study of complex microbial consortia provide a glimpse into the community metabolism and occasionally allow genomic assemblies for the most abundant organisms. However, little information is gained for the members of the community present at low frequencies, especially those representing yet-uncultured taxa, which include the bulk of the diversity present in most environments. Here we used phylogenetically directed cell separation by fluorescence in situ hybridization and flow cytometry, followed by amplification and sequencing of a fraction of the genomic DNA of several bacterial cells that belong to the TM7 phylum. Partial genomic assembly allowed, for the first time, a look into the evolution and potential metabolism of a soil representative from this group of organisms for which there are no species in stable laboratory cultures. Genomic reconstruction from targeted cells of uncultured organisms isolated directly from the environment represents a powerful approach to access any specific members of a community and an alternative way to assess the community's metabolic potential.

The levels of leptin, adiponectin, and resistin in normal weight, overweight, and obese pregnant women with and without preeclampsia.

OBJECTIVE: The purpose of this study was to compare adipokines' levels between women with and without preeclampsia based on maternal body mass index (BMI). STUDY DESIGN: This was a cross-sectional study among third-trimester pregnancies with preeclampsia (PIH) compared with normotensive controls. Serum levels of adiponectin, leptin, and resistin were measured before delivery by radioimmunoassay or enzyme-linked immunosorbent assay (ELISA). RESULTS: The study included 22 normotensive and 77 PIH women. Leptin levels increased with maternal BMI. In patients with severe preeclampsia, overweight, and obese women had increased leptin levels (33.4 +/- 14.8 vs 23.0 +/- 10.8 ng/mL respectively, P = .02), and decreased adiponectin levels (8.4 +/- 5.3 vs 12.6 +/- 6.0 ng/mL, P = .03) compared with normal weight women. In women with BMI <25 kg/m2, adiponectin levels increased in patients with preeclampsia compared with controls (11.5 +/- 5.6 vs 9.6 +/- 4.6 and 7.0 +/- 3.2 ng/mL, respectively, P = .005). There was no association between resistin levels and preeclampsia or maternal BMI. CONCLUSION: Women with severe preeclampsia and BMI > or = 25 kg/m2 have decreased adiponectin and increased leptin levels, while normal weight women with preeclampsia have increased adiponectin levels.

Cellular-free magnesium depletion in brain and muscle of normal and preeclamptic pregnancy: a nuclear magnetic resonance spectroscopic study.

Preeclampsia is a pregnancy disorder of unknown origin, characterized by vasospasm, elevated blood pressure, and increased neuromuscular irritability, features common to syndromes of magnesium deficiency. Evidence of serum and ionized magnesium metabolism disturbances have been observed in women with preeclampsia. This and the therapeutic utility of magnesium in preeclampsia led us to investigate the extent to which an endogenous tissue magnesium deficiency might be present in and contribute to its pathophysiology. We used (31)P nuclear magnetic resonance spectroscopy to noninvasively measure in situ intracellular-free magnesium levels in brain and skeletal muscle of fasting nonpregnant women (n=12), and of third trimester women with uncomplicated pregnancies (n=11) and preeclampsia (n=7). Compared with nonpregnant controls (brain 519+/-59 micromol/L; muscle 604+/-34 micromol/L), brain and skeletal muscle intracellular magnesium levels were significantly lower in both normal pregnant (brain 342+/-23 micromol/L; muscle 482+/-40 micromol/L; P=0.05 for both tissues) and preeclamptic women (brain 229+/-17 micromol/L; muscle 433+/-46 micromol/L; P=0.05 for both tissues). Brain intracellular magnesium was further reduced in preeclamptics compared with normal pregnant subjects (P=0.05). For all pregnant subjects, blood pressure was significantly and inversely related to the concomitantly measured intracellular magnesium level in brain (systolic, r=-0.59, P=0.01; diastolic, r=-0.52, P=0.02) but not in muscle. Cellular magnesium depletion is characteristic of normal pregnancy and may be one factor contributing to the pathophysiology of preeclampsia. Furthermore, the influence of central nervous system factors on blood pressure may be mediated, at least in part, by ambient intracellular magnesium levels.

Application of the transtheoretical model for HIV prevention in a facility-based and a community-level behavioral intervention research study.

This article describes the application of the transtheoretical model of behavior change to prevention programs for women at risk for or infected with HIV. The focus of these multisite demonstration projects was to increase condom and contraceptive use. The model was operationalized for use in the following two different intervention approaches: facility-based interventions (individual counseling for women in clinics, shelters, and drug treatment centers) and community-level interventions (including production of small media materials, street outreach, and community mobilization). The authors found that interventions derived from a complex theory can be disseminated to frontline providers who have little prior HIV education experience or academic training. They suggest that the transtheoretical model has value for the design and implementation of HIV prevention programs.

Day medicine: an urgent internal medicine clinic and medical procedures suite.

During Saskatchewan's healthcare reform of the 1990s, the number of acute hospital beds in Saskatoon District Health was cut in half. The emergency room and outpatient facilities were not able to accommodate an increasing number of patients needing urgent assessments and medical procedures. In this article, we describe the development, implementation and utilization of a day medicine program. This description may be useful to others planning healthcare delivery to medical patients, especially in a setting of resource constraint.

A high-throughput Arabidopsis reverse genetics system.

A collection of Arabidopsis lines with T-DNA insertions in known sites was generated to increase the efficiency of functional genomics. A high-throughput modified thermal asymmetric interlaced (TAIL)-PCR protocol was developed and used to amplify DNA fragments flanking the T-DNA left borders from approximately 100000 transformed lines. A total of 85108 TAIL-PCR products from 52964 T-DNA lines were sequenced and compared with the Arabidopsis genome to determine the positions of T-DNAs in each line. Predicted T-DNA insertion sites, when mapped, showed a bias against predicted coding sequences. Predicted insertion mutations in genes of interest can be identified using Arabidopsis Gene Index name searches or by BLAST (Basic Local Alignment Search Tool) search. Insertions can be confirmed by simple PCR assays on individual lines. Predicted insertions were confirmed in 257 of 340 lines tested (76%). This resource has been named SAIL (Syngenta Arabidopsis Insertion Library) and is available to the scientific community at www.tmri.org.

Effects of increasing carboxyhemoglobin on the single breath carbon monoxide diffusing capacity.

Although carboxyhemoglobin (COHb) is often increased in smokers, American Thoracic Society recommendations for adjusting the single breath carbon monoxide (CO) diffusing capacity (DL(CO)(SB)) for COHb remain optional. Using a previously described 3-equation technique, we measured DL(CO)(SB) and an index of diffusion inhomogeneity (DI) in 10 healthy, nonsmoking subjects who performed DL(CO)(SB) maneuvers both before and after increasing COHb. CO backpressure (FA(CO)) was measured from the exhaled gas of a standardized deep breath of room air that immediately preceded each DL(CO)(SB) and was validated by measurement of FA(CO) from an identical "sham" maneuver without inhaling CO. Without adjustments for FA(CO) or COHb, DL(CO)(SB) decreased with increasing COHb. This effect persisted when DL(CO)(SB) was adjusted only for FA(CO), but it was eliminated with further adjustment for the anemia effect of increasing COHb. The anemia adjustment was proportional to the fractional COHb. DI, adjusted for FA(CO), was unaffected by increasing COHb. We conclude that DL(CO)(SB) must be adjusted for both the buildup of CO backpressure and the anemia effect of increasing COHb. Adequate corrections of DL(CO)(SB) can be implemented using FA(CO) measured during a standardized deep breath immediately preceding the DL(CO)(SB) maneuver. Current American Thoracic Society recommendations for DL(CO)(SB) standardization do not adequately compensate for COHb.