The World Rugby and International Rugby Players Contact Load Guidelines: From conception to implementation and the future

Managing training load in rugby union is crucial for optimising performance and injury prevention. Contact training warrants attention because of higher overall injury and head impact risk, yet players must develop physical, technical, and mental skills to withstand the demands of the game. To help coaches manage contact loads in professional rugby, World Rugby and International Rugby Players convened an expert working group. They conducted a global survey with players to develop contact load guidelines. This commentary aims to describe the contact load guidelines and their implementation, and identify areas where future work is needed to support their evolution.

Benchmarking challenging small variants with linked and long reads

Genome in a Bottle benchmarks are widely used to help validate clinical sequencing pipelines and develop variant calling and sequencing methods. Here we use accurate linked and long reads to expand benchmarks in 7 samples to include difficult-to-map regions and segmental duplications that are challenging for short reads. These benchmarks add more than 300,000 SNVs and 50,000 insertions or deletions (indels) and include 16% more exonic variants, many in challenging, clinically relevant genes not covered previously, such as PMS2. For HG002, we include 92% of the autosomal GRCh38 assembly while excluding regions problematic for benchmarking small variants, such as copy number variants, that should not have been in the previous version, which included 85% of GRCh38. It identifies eight times more false negatives in a short read variant call set relative to our previous benchmark. We demonstrate that this benchmark reliably identifies false positives and false negatives across technologies, enabling ongoing methods development.

Voriconazole therapeutic drug monitoring: results of a prematurely discontinued randomized multicenter trial

BACKGROUND

Voriconazole (VOR) levels are highly variable, with potential implications to both efficacy and safety. We hypothesized that VOR therapeutic drug monitoring (TDM) will decrease the incidence of treatment failures and adverse events (AEs).

METHODS

We initiated a prospective, randomized, non-blinded multicenter study to compare clinical outcomes in adult patients randomized to standard dosing (clinician-driven) vs. TDM (doses adjusted based on levels). VOR trough levels were obtained on day 5, 14, 28, and 42 (or at completion of drug; ± 3 days). Real-time dose adjustments were made to maintain a range between 1-5 μg/mL on the TDM-arm, while levels were assessed retrospectively in the standard-arm. Patient questionnaires were administered to assess subjective AEs.

RESULTS

The study was discontinued prematurely, after 29 patients were enrolled. Seventeen (58.6%) patients experienced 38 AEs: visual changes (22/38, 57.9%), neurological symptoms (13/38, 34.2%), and liver abnormalities (3/38, 7.9%). VOR was discontinued in 7 (25%) patients because of an AE (4 standard-arm, 3 TDM-arm). VOR levels were frequently out of range in the standard-arm (8 tests >5 μg/mL; 9 tests <1 μg/mL). Three dose changes occurred in the TDM-arm for VOR levels <1 μg/mL. Levels decreased over time in the standard-arm, with mean VOR levels lower at end of therapy compared to TDM (1.3 vs. 4.6 μg/mL, P = 0.008).

CONCLUSIONS

VOR TDM has become widespread clinical practice, based on known variability in drug levels, which impaired accrual in this study. Although comparative conclusions are limited, observations of variability and waning levels over time support TDM.

Child oral health concerns amongst parents and primary care givers in a Sure Start local programme

AIM

To conduct an oral health promotion needs assessment amongst parents and primary care givers of pre-school children in a South East London Sure Start Local Programme (SSLP).

OBJECTIVE

To explore the oral health concerns and oral health literacy with regard to children's oral health amongst parents and primary care givers in a South East London SSLP.

DESIGN

A qualitative study using four in-depth focus groups with a purposive sample of 20 participants. Data were analysed using the framework method.

RESULTS

The SSLP was identified as an important source of information, support and social interaction for participants. Participants rated the informal networks of the programme as equally authoritative as other formal sources of information. Oral health concerns included: introducing healthy eating, establishing tooth brushing, teething and access to dental care. While participants had adequate knowledge of how to prevent oral disease they cited many barriers to acting on their knowledge which included: parents' tiredness, lack of confidence in parenting skills, confusing information, widespread availability of sugary foods and drinks, and lack of local child friendly dentists. Parenting skills and the social support provided by the SSLP appeared to be integral to the introduction of positive oral health behaviours.

CONCLUSIONS

SSLPs were seen as a trusted source of support and information for carers of pre-school children. Integration of oral health promotion into SSLPs has the potential to tap into early interventions which tackle the wider support needs of carers of pre-school children while also supporting the development of positive oral health behaviours.

Understanding the motivation: a qualitative study of dental students' choice of professional career

BACKGROUND

Given the changing nature of the dental workforce, and the need to retain the services of future members, it is important to understand why current dental students perceive that they were motivated to study dentistry. Qualitative research provides the opportunity to explore the underlying issues in addition to informing subsequent quantitative research. The objectives of this research were to investigate final-year dental students' motivation for studying dentistry and how they perceive this has been modified during their undergraduate degree programme.

METHODS

Purposive sampling of a representative group of 35 final-year dental students at King's College London Dental Institute to participate in audio-taped focus groups. Qualitative data were analysed using Framework Methodology.

RESULTS

The findings suggest a strong emphasis on having a career, providing 'professional status', 'financial benefits', 'job security, flexibility and independence' and 'good quality of life'. Students reported being attracted by features of the job, supported to a greater or lesser extent by personal experience, family and friends. It appears however that students' initial motivation is being tempered by their experiences during their undergraduate degree programme, in particular, the 'responsibilities of an intensive professional education', their 'mounting student debt' and the perception of 'feeling undervalued'. This perception related to dentistry in general and National Health Service dentistry in particular, being undervalued, by government, patients, the public and members of the dental profession.

CONCLUSIONS

Students' vision of a 'contained professional career' within health care, providing status and financial benefits, appears to have influenced their choice of dentistry. Pressures relating to student life and policy changes are perceived as impacting on key components of professional life, particularly status in the social and economic order. The implications for educators, professional leaders and policy makers are explored.

Accelerated escape from GH autonegative feedback in midpuberty in males: evidence for time-delimited GH-induced somatostatinergic outflow in adolescent boys

A single injected pulse of GH inhibits the time-delayed secretion of GH in the adult by way of central mechanisms that drive somatostatin and repress GHRH outflow. The marked amplification of spontaneous GH pulse amplitude in puberty poses an autoregulatory paradox. We postulated that this disparity might reflect unique relief of GH-induced autonegative feedback during this window of development. The present study contrasts GH autonegative feedback in: 1) normal prepubertal boys (PP) (n = 6; Tanner genital stage I, chronologically aged 8 yr, 9 months to 10 yr, 1 month; median bone age 8.5 yr); 2) longitudinally identified midpubertal boys (MP) (n = 6; Tanner genital stages III/IV, aged 12 yr, 6 months to 15 yr, 6 months; median bone age 15 yr); and 3) healthy young men (YM) (n = 6, aged 18-24 yr; bone age >18 yr). Subjects each underwent four randomly ordered tandem peptide infusions on separate mornings while fasting: i.e. 1) saline/saline infused iv bolus at 0830 h and 1030 h; 2) saline/GHRH (0.3 microg/kg i.v. bolus) at the foregoing times; 3) recombinant human (rh) GH (3 microg/kg as a 6-min square-wave i.v. pulse)/saline; and 4) rhGH and GHRH. To monitor GH autofeedback effects, blood samples were obtained every 10 min for 5.5 h beginning at 0800 h (30 min before GH or saline infusion). Serum GH concentrations were quantitated by ultrasensitive chemiluminometry (threshold 0.005 microg/liter). On the day of successive saline/saline infusion, MP boys maintained higher serum concentrations of: 1) GH ( microg/liter), 2.2 +/- 0.25, compared with PP (0.61 +/- 0.10) or YM (0.88 +/- 0.36) (P = 0.011); 2) IGF-I ( micro g/liter), 493 +/- 49 vs. PP (134 +/- 16) and YM (242 +/- 22) (P < 0.001); 3) T (ng/dl), 524 +/- 58 vs. PP (<20) (P < 0.001); and 4) E2 (pg/ml),19 +/- 3 vs. PP (< 10) (P = 0.030) (mean +/- SEM). Consecutive saline/GHRH infusion elicited comparable peak (absolute maximal) serum GH concentrations (micrograms per liter) in the three study groups, i.e. 18 +/- 5.0 (PP), 9.6 +/- 1.7 (MP), and 14 +/- 5.3 (YM) (each P < 0.01 vs. saline; P = NS cohort effect). Injection of rhGH attenuated subsequent GHRH-stimulated peak serum GH concentrations (micrograms per liter) to 7.8 +/- 1.9 (PP), 5.8 +/- 1.2 (MP), and 4.8 +/- 1.1 (YM) (each P < 0.01 vs. saline; P = NS pubertal effect). GH autofeedback reduced non-GHRH-stimulated (basal) serum GH concentrations by 0.74 +/- 0.28 (PP), 5.7 +/- 1.7 (MP) and 1.4 +/- 0.27 (YM) fold, compared with saline (P = 0.016 for MP vs. PP or YM). In addition to greater fractional autoinhibition, MP boys exhibited markedly accentuated postnadir escape (4.6-fold steeper slope) of suppressed GH concentrations (P < 0.001 vs. PP or YM). Linear regression analysis of data from all 18 subjects revealed that the fasting IGF-I concentration negatively predicted fold-autoinhibition of GHRH-stimulated peak GH release (r = -0.847, P = 0.006) and positively forecast fold-autoinhibition of basal GH release (r = +0.869, P < 0.001). In contrast, the kinetics of rhGH did not differ among the three study cohorts. In summary, boys in midpuberty manifest equivalent responsiveness to exogenous GHRH-stimulated GH secretion; heightened susceptibility to rhGH-induced fractional inhibition of endogenous secretagogue-driven GH release, compared with the prepubertal or adult male; and accelerated recovery of GH output after acute autonegative feedback. This novel tripartite mechanism could engender recurrent high-amplitude GH secretory bursts that mark sex hormone-dependent activation of the human somatotropic axis.

Driving mishaps and hypoglycaemia: risk and prevention

Driving is a complex, multi-task activity that can be affected by cognitive impairment resulting from episodes of severe hypoglycaemia. Intensive insulin therapy increases the likelihood of severe hypoglycaemia but there have been few studies examining effects on driving skills. A survey carried out recently indicated that patients with type 1 diabetes had twice the incidence of driving accidents than their non-diabetic spouses or patients with type 2 diabetes. The motor accidents were associated with more frequent low blood glucose while driving and less frequent self-monitoring. In driving simulation tests it was found that driving has an intrinsic metabolic demand that can contribute to hypoglycaemia. Driving performance began to deteriorate at around 3.6 mmol/l but drivers frequently did not recognise and failed to treat the hypoglycaemia. Those who did self-treat had more driving relevant symptoms and less neuroglycopenia quantified by EEG alpha-theta differences. Patients should be recommended not to begin driving if blood glucose is below 4.5 mmol/l and should not continue to drive if they suspect that blood glucose has fallen below 4 mmol/l while driving. If hypoglycaemia is suspected patients should immediately pull off the road, measure blood glucose if possible, treat themselves as necessary and not resume driving until glucose and cognitive-motor function return to normal. The problems of driving and hypoglycaemia should be discussed with patients with diabetes and behavioural interventions instigated. To this end, Blood Glucose Awareness Training (BGAT) and Hypoglycaemia Anticipation, Awareness and Treatment Training (HAATT) have been developed and shown to markedly reduce incidence of driving mishaps.

Bedside glucose testing. Applications in the home and hospital

Point-of-care testing is an increasingly popular means of delivering diagnostic testing closer to the site of patient care. Although point-of-care glucose testing devices have been around for over a decade, concerns about the quality of the results still plague the industry. Changes in federal and state laws that treat point-of-care testing as an extension of the core laboratory promise to improve the quality of testing. The most challenging aspect of quality testing is selection of the appropriate method (core laboratory versus point-of-care test) for the optimal patient outcome.

Analysis of free drug fractions by ultrafast immunoaffinity chromatography

A chromatographic method was developed for measuring the nonbound (or free) fraction of drugs by using millisecond-scale extractions on small immunoaffinity columns. The design of this system was developed by considering the dissociation rates of (R)- and (S)-warfarin from the binding protein human serum albumin (HSA) and by performing computer simulations of the immunoaffinity extraction of these drugs. The final system was tested by using it to measure the free fractions of (R)- or (S)-warfarin in samples with known concentrations of these agents and HSA. The free warfarin fraction was extracted in 180 ms by a 2.1-mm-i.d. sandwich microcolumn that contained a 1.1-mm layer of an anti-warfarin antibody support. The nonretained peaks from this immunoaffinity column were passed through a series internal surface reversed-phase columns and a fluorescence detector for the analysis of any protein-bound warfarin that remained in the sample. The experimental results were found to have good agreement with those predicted from the known equilibrium constants for the binding of (R)- and (S)-warfarin with HSA. This approach can be modified for other analytes by changing the types of antibodies that are used in the immunoaffinity column and by using an appropriate detector for the nonretained drug fraction.

Sustained effects of gene-activated matrices after CNS injury

We show that when gene-activated matrices (GAM) are placed between the proximal and distal stumps of severed rat optic nerves, DNA is retained within the GAM, promoting sustained transgene expression in the optic nerve, in the GAM itself, and, more importantly, in axotomized retinal ganglion cells (RGC). Plasmids that encode basic fibroblast growth factor (FGF2), brain-derived neurotrophic factor (BDNF), and neurotrophin-3 (NT3) promote sustained survival of RGC for over 3 months after the initial injury. These findings suggest that immobilized DNA implanted into a CNS lesion will be delivered by axon terminal uptake and retrograde transport to axotomized neurons. GAM may therefore be a useful agent for promoting sustained neuron survival and axon regeneration. Whether further optimization of the matrices, plasmids, promoters, and genes present in the GAM will promote even more survival or, alternatively, axon regeneration remains to be determined.

Blood glucose awareness training (BGAT-2): long-term benefits

OBJECTIVE

Blood glucose awareness training (BGAT) has been shown to improve awareness of blood glucose (BG) fluctuations among adults with type 1 diabetes. This study investigates the long-term (12-month) benefits of BGAT-2.

RESEARCH DESIGN AND METHODS

A total of 73 adults with type 1 diabetes participated in a 6-month repeated baseline design with a 12-month follow-up. At 6 months and 1 month before BGAT-2 and at 1,6, and 12 months after BGAT-2, subjects used a handheld computer for 50 trials and completed psychological tests. Throughout assessment, subjects completed diaries, recording occurrences of diabetic ketoacidosis, severe hypoglycemia, and motor vehicle violations During follow-up, 50% of the subjects received booster training.

RESULTS

During the first and last halves of both the baseline period and the follow-up period, dependent variables were generally stable. However, from baseline to follow-up, BGAT-2 led to 1) improved detection of hypoglycemia and hyperglycemia; 2) improved judgment regarding when to lower high BG, raise low BG, and not drive while hypoglycemic; 3) reduction in occurrence of diabetic ketoacidosis, severe hypoglycemia, and motor vehicle violations; and 4) improvement in terms of worry about hypoglycemia, quality of life, and diabetes knowledge. Reduction in severe hypoglycemia was not associated with a worsening of metabolic control (HbA1). The presence or absence of booster training did not differentially affect these benefits.

CONCLUSION

BGAT has sustained broad-ranging benefits, independent of booster intervention.

Development of sandwich HPLC microcolumns for analyte adsorption on the millisecond time scale

A new class of columns is reported that uses only microgram quantities of active support and that provides for the retention of biological compounds and other analytes on the millisecond time scale. This was accomplished by packing standard HPLC supports into layers as small as 60 microm in length and using only 90 microg of support material. This provided columns with effective residence times in the millisecond time range when routine HPLC flow rates and pressures were used. The retention of analytes by such columns was examined under both adsorption- and diffusion-limited conditions. The RPLC adsorption of hemoglobin (a system with diffusion-limited retention) was found to give 95% binding in as little as 4 ms. The adsorption of fluorescein by an anti-fluorescein antibody column (an adsorption-limited system) gave 95% retention in 100-120 ms. One application examined for these columns was their use in a chromatographic-based competitive binding immunoassay. This used bovine serum albumin (BSA) as the model analyte, and fluorescein-labeled BSA was used for detection. The resulting approach had a contact time of 180 ms between the sample and an anti-BSA immunoaffinity microcolumn and provided a signal within 5-25 s after sample injection. The columns developed in this work should also be useful in other situations that involve a small amount of a stationary phase or that require short column residence times.

Microbial quality of water in rural communities of Trinidad

A cross-sectional study was conducted in four rural communities of northeastern Trinidad to determine the microbial quality of water supply to households and that quality's relationship to source and storage device. Of the 167 household water samples tested, total coliforms were detected in 132 of the samples (79.0%), fecal coliforms in 102 (61.1%), and E. coli in 111 (66.5%). There were significant differences among the towns in the proportion of the samples contaminated with coliforms (P < 0.001) and E. coli (P < 0.001). Of 253 strains of E. coli studied, 4 (1.6%) were mucoid, 9 (3.6%) were hemolytic, and 37 (14.6%) were nonsorbitol fermenters. Of 69 isolates of E. coli tested, 10 (14.5%) were verocytotoxigenic. Twenty-eight (14.0%) of 200 E. coli isolates tested belonged to enteropathogenic serogroups. Standpipe, the most common water source, was utilized by 57 (34.1%) of the 167 households. Treated water (pipeborne in homes, standpipes, or truckborne) was supplied to 119 households (71.3%), while 48 households (28.7%) used water from untreated sources (rain, river/stream, or well) as their primary water supply. The type of household storage device was associated with coliform contamination. Water stored in drums, barrels, or buckets was more likely to harbor fecal coliforms (74.2% of samples) than was water stored in tanks (53.3% of samples), even after controlling for water source (P = 0.04). Compared with water from other sources, water piped into homes was significantly less likely to be contaminated with total coliforms (56.9% versus 88.8%, P < 0.001) and fecal coliforms (41.2% versus 69.8%, P < 0.01), even when the type of storage device was taken into account. However, fecal contamination was not associated with whether the water came from a treated or untreated source. We concluded that the drinking water in rural communities in Trinidad was grossly unfit for human consumption, due both to contamination of various water sources and during household water storage.

Antibody immobilization to high-performance liquid chromatography supports. Characterization of maximum loading capacity for intact immunoglobulin G and Fab fragments

This study examined various factors that affect the maximum amount of intact immunoglobulin G (IgG) or Fab fragments that can be covalently immobilized to silica and other HPLC-grade supports for use in immunoaffinity chromatography or immunoextractions. Factors that were considered included the amount of surface area available for immobilization, the pore size of the support, the type of immobilization method and the nature of the support matrix. The main factor in determining the extent of immobilization was found to be the relationship between the support's surface area and the ability of the IgG or Fab fragments to reach this surface. Access to the support surface was a function of the size of the protein being immobilized and the support porosity, with maximum immobilization being obtained with supports having pore sizes of approximately 300 A for intact IgG and 100 A for Fab fragments. Some differences in the maximum level of immobilization were noted between different coupling methods. Supports like Poros and Emphaze gave similar results to those seen with HPLC-grade silica when a comparison was made between materials with comparable pore sizes. Many of the trends observed in this work for IgG and Fab fragments should apply to other proteins that are to be immobilized to HPLC supports.

Development of a theoretical model for chromatographic-based competitive binding immunoassays with simultaneous injection of sample and label

This study examined the theory and behavior of an HPLC-based chromatographic competitive binding immunoassay with the simultaneous injection of sample and a labeled analyte analogue. Equations based on nonlinear chromatographic theory were derived to describe the calibration curve for this assay in a system with adsorption-limited kinetics and homogeneous binding sites. These equations related the assay response (B/Bo) to the column's binding capacity, the moles of injected analyte or labeled analogue, and the flow rate/adsorption kinetics of the system. There was good agreement between the predicted theoretical response and experimental data obtained for the binding of human serum albumin (HSA) to an immobilized anti-HSA antibody column. This theory was also successful in describing the changes that occurred in the calibration curve when the flow rate or amount of labeled analogue applied to the column was varied. A comparison was made between the results of this study and previous theoretical work that examined the behavior of a related, sequential injection competitive binding method. On the basis of the results reported in this work, several general guidelines were developed for the design and optimization of simultaneous injection methods for use in such areas as clinical testing, pharmaceutical analysis, and environmental monitoring.

Prevalence of elevated blood leads and exposure to lead in construction trades in Iowa and Illinois

BACKGROUND

Despite lowering of the permissible exposure level for lead in construction from 200 to 50 microg/m3 in 1993, excessive lead exposure continues to be a problem. Relatively little data are available from the Midwestern U.S. on the environmental lead concentrations generated during various construction activities and the potential for worker exposure. This study characterized the prevalence of blood lead concentrations in high-risk construction trades in Iowa/Illinois, and identified risk factors for occupational exposure to lead in these construction workers.

METHODS

A sample of 459 workers was selected from the total population of all union members from trade groups of painters, plumbers/pipefitters, ironworkers, laborers, and electricians. Participants completed an interviewer-administered questionnaire obtaining information on demographics, symptoms, occupational history, work practices, personal protective equipment, and training. Venous blood samples were collected from each participant and analyzed for blood lead (using atomic absorption spectroscopy) and free erythrocyte protoporphyrin levels.

RESULTS

Blood lead levels (BLLs) of construction workers ranged from 0.1 to 50 microg/dL. Geometric mean blood lead concentrations by trade group were: laborers (7.6 microg/dL, n = 80); painters (5.9 microg/dL, n = 83); ironworkers (5.2 microg/dL, n = 87); plumbers (4.4 microg/dL, n = 82); electricians (2.4 microg/dL, n = 91). Blood lead levels for painters and laborers were significantly higher than other trade groups, and levels for electricians were significantly lower (p < 0. 01). Participants reported working primarily on commercial and industrial projects including new construction, renovation, and demolition. There were significant differences between the types of projects performed by different trade groups with laborers performing more highway/bridge renovation (p < 0.01), and plumbers reporting more residential remodeling (p = 0.05), repair of water lines containing lead (p = 0.04), or work on lead joints (p < 0.01). In addition to trade, elevated blood lead levels were associated with the type of construction project (especially bridge renovation and residential remodeling) and activities that include welding, cutting, rivet busting. The age of the home in which the worker lived, and hobbies such as casting/smelting lead for bullets or sinkers, were also important risk factors. Compliance with OSHA's Construction Lead Standard, and implementation of good occupational health and safety practices in general, was poor.

CONCLUSIONS

Blood lead levels of 459 construction workers differed by the type of trade, type of project and specific job activity owing to differences in the inherent exposure potential of each task. Although the numbers of workers performing lead abatement projects were small, the trend for lower BLL in this group provides evidence that training, implementation of engineering controls, and proper use of personal protective equipment such as respirators is effective in controlling lead poisoning.

Clinical comparability of albuterol delivered by the breath-actuated inhaler (Spiros) and albuterol by MDI in patients with asthma

STUDY OBJECTIVE

This study compares the efficacy and safety of one and two actuations of albuterol sulfate powder delivered via a breath-actuated, effort-assisted, investigational inhaler (Spiros, Dura Pharmaceuticals, Inc) and albuterol delivered via a conventional propellant-driven metered dose inhaler (Ventolin, Glaxo, Inc).

DESIGN

Randomized, double-blind, placebo-controlled, 5-way crossover study.

PARTICIPANTS

Sixty patients with mild-to-moderate asthma (FEV1 59% predicted) were enrolled and 44 completed the study.

MEASUREMENTS AND RESULTS

FEV1 values over 6 hours were analyzed by ANCOVA and the Finney relative potency model. The relative potency of the inhalers (albuterol MDI: albuterol DPI) was 1.132 (90% CI, 0.680 to 2.252) indicating 1.132 actuations of albuterol MDI provided the same bronchodilation as one actuation of albuterol DPI. ANCOVA analyses further indicated that there were no significant differences between the two delivery systems with respect to FEV1, FVC, FEF25-75%, or PEF. Both inhalers had similar effects on serum potassium levels, QTc interval, blood pressure, and heart rate.

CONCLUSIONS

In patients with mild-to-moderate asthma in this study, the albuterol DPI was determined to be therapeutically comparable to albuterol MDI in the delivery of one and two actuations of albuterol.

Role of the toxic neutrophil count in the early diagnosis of Kawasaki disease

OBJECTIVE

To determine whether the toxic neutrophil count (TNC), defined as the sum of the number of peripheral blood neutrophils with vacuoles plus the number with toxic granulations per 100 neutrophils examined, can be used as an aid to early diagnosis of Kawasaki disease (KD).

METHODS

Prospective evaluation at a tertiary care pediatric hospital of 56 acutely febrile children with at least one other clinical criterion for KD. Clinical characteristics and TNC were compared for 3 groups of patients: those with (1) definite KD, (2) probable KD, and (3) unlikely KD. The sensitivity and specificity of the TNC at various cutoff points was determined.

RESULTS

We evaluated 56 patients (Group 1, N=27; Group 2, N=4; Group 3, N=25). Mean TNC (TNC/mm3) were higher in the patients with definite KD compared to patients with unlikely KD (38 vs 24; p=0.037). At a TNC cutoff of > or =70, the test had a specificity of 100%, but a sensitivity of only 18%. The likelihood ratio (the number of times more likely this TNC result is to be found in KD versus non-KD subjects) was 8.89. At a cutoff of > or =10, the test had a high sensitivity of 92% and specificity of 38%.

CONCLUSION

No laboratory test replaced the need for careful clinical evaluation in cases of suspected KD. The TNC may be a useful adjunct to the clinical assessment of children with KD, particularly at the extremes of measurement.

Assessment of risk for severe hypoglycemia among adults with IDDM: validation of the low blood glucose index

OBJECTIVE

To evaluate the clinical/research utility of the low blood glucose index (LBGI), a measure of the risk of severe hypoglycemia (SH), based on self-monitoring of blood glucose (SMBG).

RESEARCH DESIGN AND METHODS

There were 96 adults with IDDM (mean age 35+/-8 years, duration of diabetes 16+/-10 years, HbA1 8.6+/-1.8%), 43 of whom had a recent history of SH (53 did not), who used memory meters for 135+/-53 SMBG readings over a month, and then for the next 6 months recorded occurrence of SH. The SMBG data were mathematically transformed, and an LBGI was computed for each patient.

RESULTS

The two patient groups did not differ with respect to HbA1, insulin units per day, average blood glucose (BG) and BG variability. Patients with history of SH demonstrated a higher LBGI (P < 0.0005) and a trend to be older with longer diabetes duration. Analysis of odds for future SH classified patients into low- (LBGI <2.5), moderate- (LBGI 2.5-5), and high- (LBGI >5) risk groups. Over the following 6 months low-, moderate-, and high-risk patients reported 0.4, 2.3, and 5.2 SH episodes, respectively (P = 0.001). The frequency of future SH was predicted by the LBGI and history of SH (R2 = 40%), while HbA1, age, duration of diabetes, and BG variability were not significant predictors.

CONCLUSIONS

LBGI provides an accurate assessment of risk of SH. In the traditional relationship history of SH-to-future SH, LBGI may be the missing link that reflects present risk. Because it is based on SMBG records automatically stored by many reflectance meters, the LBGI is an effective and clinically useful on-line indicator for SH risk.

Kinetic studies on the immobilization of antibodies to high-performance liquid chromatographic supports

Several factors can potentially affect the rate of immobilization of proteins onto solid supports, such as those used in affinity-based high-performance liquid chromatography. This study examined several of these factors and their influence on the coupling of periodate-treated rabbit immunoglobulin G antibodies to dihydrazide-activated silica. Items considered included the number of potential coupling sites on the antibodies, the density of activated sites on the support, the relative amount of antibody combined with the support, and the density of the overall reaction slurry. In each case, the rate of change in the solution-phase antibody concentration gave biphasic behavior which could be described by two competing pseudo-first-order reactions. The overall immobilization rate was essentially independent of the density of the support's activated sites (when present at a coverage of 0.1-0.4 micromol/m2) but was strongly influenced by the number of available coupling groups on the antibodies. Increasing the slurry density had no appreciable effect on the immobilization rate, and the reaction rate showed only a small change when using different types of reagents for support activation (e.g., adipic vs oxalic dihydrazide). These results are consistent with a mechanism in which the rate-limiting step during immobilization is the covalent attachment of antibodies to the support and not mass transfer of antibodies to the support's surface.

Stochastic model of self-regulation decision making exemplified by decisions concerning hypoglycemia

The following sequence-internal condition --> symptom perception --> appraisal --> decision-models various symptom-based self-regulation processes. A formal mathematical model describes the first three steps by continuous variables and the decisions at the fourth step by binary variables. The stochastic transitions between the sequential steps are quantified by transition probabilities. The model is illustrated by blood glucose level estimation and detection and treatment of hypoglycemia in 78 patients with insulin-dependent diabetes mellitus. These patients made 50 to 70 data collection trials over 3 to 4 weeks recording perceived symptoms, cognitive-motor performance, subjective estimates of blood glucose, decisions about treatment of hypoglycemia, and driving. A statistical estimation of the model's parameters demonstrates the utility of this approach for understanding the awareness, detection, and treatment of hypoglycemia as a process of symptom-based decision making.

Symmetrization of the blood glucose measurement scale and its applications

OBJECTIVE

To introduce a data transformation that enhances the power of blood glucose data analyses.

RESEARCH DESIGN AND METHODS

In the standard blood glucose scale, hypoglycemia (blood glucose, < 3.9 mmol/l) and hyperglycemia (blood glucose, > 10 mmol/l) have very different ranges, and euglycemia is not central in the entire blood glucose range (1.1-33.3 mmol/l). Consequently, the scale is not symmetric and its clinical center (blood glucose, 6-7 mmol/l) is distant from its numerical center (blood glucose, 17 mmol/l). As a result, when blood glucose readings are analyzed, the assumptions of many parametric statistics are routinely violated. We propose a logarithmic data transformation that matches the clinical and numerical center of the blood glucose scale, thus making the transformed data symmetric.

RESULTS

The transformation normalized 203 out of 205 data samples containing 13,584 blood glucose readings of 127 type 1 diabetic individuals. An example illustrates that the mean and standard deviation based on transformed, rather than on raw, data better described subject's blood glucose distribution. Based on transformed data: 1) the low blood glucose index predicted the occurrence of severe hypoglycemia, while the raw blood glucose data (and glycosylated hemoglobin levels) did not; 2) the high blood glucose index correlated with the subjects' glycosylated hemoglobin (r = 0.63, P < 0.001); and 3) the low plus high blood glucose index was more sensitive than the raw data to a treatment (blood glucose awareness training) designed to reduce the range of blood glucose fluctuations.

CONCLUSIONS

Using symmetrized, instead of raw, blood glucose data strengthens the existing data analysis procedures and allows for the development of new statistical techniques. It is proposed that raw blood glucose data should be routinely transformed to a symmetric distribution before using parametric statistics.

The psychosocial impact of severe hypoglycemic episodes on spouses of patients with IDDM

OBJECTIVE

No previous studies have examined the psychosocial impact of severe hypoglycemic episodes in IDDM patients on their spouses. This study compared spouses of IDDM patients with and without a history of recent severe hypoglycemia (SH) using traditional measures of psychosocial status and marital conflict, as well as diabetes-specific measures.

RESEARCH DESIGN AND METHODS

A total of 61 nondiabetic spouses (23 wives and 38 husbands) of IDDM patients participated in the study. Spouses completed a battery of traditional psychometric measures (depression, anxiety, marital conflict) and diabetes-specific measures (fear of hypoglycemia, marital conflict over diabetes, sleep disturbance caused by hypoglycemia). Scores of spouses of IDDM patients with and without a recent history of SH were compared with t tests.

RESULTS

Spouses of IDDM patients with and without a recent history of SH showed no differences on traditional psychometric measures of depression, anxiety, and marital conflict. However, spouses of patients with a recent history of SH showed significantly more fear of hypoglycemia, marital conflict about diabetes management, and sleep disturbances caused by hypoglycemia. Exploratory analyses of variance (ANOVAs) found no differences on psychometric measures between wives and husbands, with the exception that husbands of SH patients reported more sleep disturbance. Nondiabetic spouses, on average, showed greater fear of hypoglycemia than their diabetic partners.

CONCLUSIONS

Although SH in IDDM patients can have a significant impact on the psychosocial status of their spouses, in this study the negative impact was restricted to areas of life that are directly related to diabetes and its management. Thus, SH per se is not necessarily associated with significant increases in spousal anxiety, depression, or marital conflict, but may be associated with types of diabetes-specific psychosocial distress that are not easily identified by traditional psychometric measures.

Sterilization using pulsed white light

Pulsed light is a non-thermal sterilization method that uses brief intense pulses or flashes of white light to kill micro-organisms. This article discusses tests performed on blow/fill/seal containers. The results suggest that pulsed light has potential as a terminal sterilization method for filled and sealed transmissive products and packages. It also examines the effectiveness of pulsed light in eliminating water-borne pathogenic organisms.

A biopsychobehavioral model of risk of severe hypoglycemia

Severe hypoglycemia (SH) is a significant problem for many patients with type I diabetes and presents a major barrier to optimal diabetes control. A critical task facing diabetes research is to understand, predict, and reduce the risk of SH in insulin-treated patients. The purpose of this article is to propose a biopsychobehavioral model of SH risk that integrates and extends previously proposed models. Current biological and psychological models of SH risk, which focus on hormonal counterregulation and symptom awareness, are reviewed. The limitations of these models are also discussed, including their failure to recognize important psychological and behavioral processes that contribute to SH risk. Specifically, the biopsychobehavioral model includes patients' decision-making, judgment, and behavioral responses as significant predictors of SH risk. The proposed model is comprised of seven steps: 1) physiological and behavioral precursors to low blood glucose (BG), 2) low BG occurrence, 3) hormonal and neurological responses to low BG, 4) awareness of symptoms caused by hormonal and neurological changes, 5) detection of low BG, 6) decision-making and judgment, and 7) behavioral response. The model has several advantages, including the ability to mathematically calculate the transitional probabilities from each step to the next as well as the ability to describe SH risk in both hypoglycemia-aware and hypoglycemia-unaware patients. Research findings supporting the biopsychobehavioral model are presented, and its empirical and clinical implications are discussed.

Inhibition of cyclic 3'-5'-guanosine monophosphate-specific phosphodiesterase selectively vasodilates the pulmonary circulation in chronically hypoxic rats

While it is known that nitric oxide (NO) is an important modulator of tone in the hypertensive pulmonary circulation, the roles of cyclic 3'-5'-guanosine monophosphate (cGMP) and cGMP-phosphodiesterase (PDE) are uncertain. We found that isolated lung perfusate levels of cGMP were over ninefold elevated in hypertensive vs. normotensive control rats. 98-100% of lung cGMP hydrolytic activity was cGMP-specific PDE5, with no significant decrease in PDE activity in hypertensive lungs, suggesting that the elevation in cGMP was due to accelerated production rather than reduced degradation. In pulmonary hypertensive rat lungs, in vitro, cGMP-PDE inhibition by E4021[1-(6-chloro-4-(3,4-methylbenzyl) amino-quinazolin-2-yl)piperdine-4-carboxylate], increased perfusate cGMP threefold, reduced hypoxic vasoconstriction by 58 +/- 2%, and reduced baseline pulmonary artery pressure by 37 +/- 5%. In conscious, pulmonary hypertensive rats, intravenous administration of E4021 reduced hypoxic vasoconstriction by 68 +/- 8%, pulmonary artery pressure by 12.6 +/- 3.7% and total pulmonary resistance by 13.1 +/- 6.4%, with no significant effect on cardiac output, systemic pressure, and resistance. Comparison of E4021 to inhaled nitric oxide demonstrated that cGMP-PDE inhibition was as selective and as effective as inhaled NO.

A multicenter evaluation of blood glucose awareness training-II

OBJECTIVE

Blood glucose awareness training (BGAT) teaches individuals with insulin-dependent diabetes to more accurately estimate/detect their blood glucose (BG) fluctuations. It has not, however, consistently resulted in improved ability to detect low BG. To assess an enhanced version of BGAT (BGAT-II), with more focus on increasing sensitivity to low BG events, a multicenter study was undertaken. Following up on previous findings that BGAT is most effective with individuals who are least accurate in estimating BG, this study explicitly recruited subjects who did and did not report reduced awareness of hypoglycemia.

RESEARCH DESIGN AND METHODS

Seventy-eight subjects from three research sites participated in a repeated baseline design. Subjects' BG estimation accuracy and BG profiles were assessed 6 months before, immediately before, and immediately after BGAT-II.

RESULTS

Post-treatment, BGAT-II led to better overall accuracy in detecting BG fluctuations and better detection of both low and high BG levels. This was achieved while the number of low readings of self-monitoring of blood glucose (SMBG) was reduced. Reduction in the number of low SMBG events was significant only for subjects reporting awareness of hypoglycemia. Detection of low BG was significant only for subjects reporting reduced awareness of hypoglycemia. Both groups demonstrated equivalent improvements in detection of high BG levels.

CONCLUSIONS

BGAT may be an effective behavioral strategy for reversing hypoglycemic unawareness and an adjunct to intensive insulin therapy to reduce the occurrence of severe hypoglycemia.

Synthesis of (+)-(R)- and (-)-(S)-trans-8-hydroxy-2-[N-n-propyl-N-(3'-iodo-2'-propenyl)] aminotetralin: new 5-HT1A receptor ligands

(R,S)-trans-8-Hydroxy-2-[N-n-propyl-N-(3'-iodo-2'- propenyl)amino]tetralin 7, a new radioiodinated ligand based on 8-OH-DPAT, was reported as a potential ligand for 5-HT1A receptors. The optically active (+)-(R)- and (-)-(S)-7 were prepared to investigate the stereoselectivity of (R,S)-7. Racemic intermediate 8-methoxy-2-N-n-propyltetralin was reacted with the acyl chloride of (-)-(R)-O-methylmandelic acid to form a mixture of (S,R)- and (R,R)-diastereoisomers, which were separated by flash column chromatography. After removing the N-acyl group from the diastereoisomers, the desired (+)-(R)- or (-)-(S)-7 was obtained by adding an N-iodopropenyl group. In vitro homogenate binding studies showed the stereoselectivity of this new compound for 5-HT1A receptors. (+)-(R)-7 isomer displayed 100-fold higher affinity than the (-)-(S)-7 isomer. Biochemical study indicated that (+)-(R)-7 potently inhibited forskolin-stimulated adenylyl cyclase activity in hippocampal membranes (Emax and EC50 were 24.5% and 5.4 nM, respectively), while (-)-(S)-7 showed no effect at 1 microM. The radioiodinated (+)-(R)- and (-)-(S)-[125I]7 were confirmed by coelution with the resolved unlabeled compound on HPLC (reverse phase column PRP-1, acetonitrile/pH 7.0 buffer, 80/20). The active isomer, (+)-(R)-[125I]7, displayed high binding affinity to 5-HT1A receptors (Kd = 0.09 +/- 0.02 nM). In contrast, the (-)-(S)-7 isomer displayed a significantly lower affinity to the 5-HT1A receptor (Kd > 10 nM).(ABSTRACT TRUNCATED AT 250 WORDS)

Antiemetic prophylaxis for strabismus surgery

Droperidol can reduce the high incidence of vomiting after pediatric strabismus surgery; however, its use may be associated with sedation, delayed hospital discharge, dysphoria and extrapyramidal signs. Midazolam, a short-acting benzodiazepine with antiemetic properties, has few side effects and may be a suitable alternative. We prospectively compared the antiemetic effect of these two drugs in 393 healthy children aged 18 months to 14 years undergoing outpatient strabismus surgery. The children were randomly assigned to receive midazolam hydrochloride (50 micrograms/kg) (199 patients) or droperidol (50 micrograms/kg) (194 children). The incidence rates of vomiting in the two groups were 45% and 37% respectively, a nonsignificant difference. The incidence of vomiting was not affected by the duration of anesthesia, but the number of muscles repaired was a significant predictor of postoperative vomiting (p < 0.001).

Parent-child relationships and the management of insulin-dependent diabetes mellitus

Several dimensions of parent-child relationships were examined as predictors of adherence to treatment and metabolic control in a multi-informant study of 88 children and adolescents with insulin-dependent diabetes mellitus who were recruited from 2 endocrinology clinics. Ratings of parent-child discipline, warmth, and behavioral support were not significantly associated with diabetes outcome, but parent-child conflict was a consistent correlate of both adherence and metabolic control. Within a public hospital subsample, conflict was related to parent, child, and nurse ratings of adherence and to a physiological index of metabolic control. These results were partially replicated in a private practice sample where conflict was significantly related to parents' ratings of adherence and to metabolic control. Conflict accounted for unique variance in diabetes outcome beyond that associated with other measures of the parent-child relationship, but the relation between conflict and metabolic control was no longer significant when adherence ratings were entered into regression equations first.

Parent-child relationships and the management of insulin-dependent diabetes mellitus

Several dimensions of parent-child relationships were examined as predictors of adherence to treatment and metabolic control in a multi-informant study of 88 children and adolescents with insulin-dependent diabetes mellitus who were recruited from 2 endocrinology clinics. Ratings of parent-child discipline, warmth, and behavioral support were not significantly associated with diabetes outcome, but parent-child conflict was a consistent correlate of both adherence and metabolic control. Within a public hospital subsample, conflict was related to parent, child, and nurse ratings of adherence and to a physiological index of metabolic control. These results were partially replicated in a private practice sample where conflict was significantly related to parents' ratings of adherence and to metabolic control. Conflict accounted for unique variance in diabetes outcome beyond that associated with other measures of the parent-child relationship, but the relation between conflict and metabolic control was no longer significant when adherence ratings were entered into regression equations first.

Long-term follow-up evaluation of blood glucose awareness training

OBJECTIVE

Blood glucose awareness training (BGAT) has been found effective in teaching individuals with insulin-requiring diabetes to improve their ability to better recognize blood glucose (BG) fluctuations. This study investigated whether subjects who underwent BGAT a mean of 4.9 years previously were superior to past control subjects in terms of their ability to recognize BG fluctuations, and whether past BGAT subjects had fewer automobile crashes and lost work days and better glycosylated hemoglobin than control subjects. Additionally, the beneficial effects of providing booster training to past BGAT subjects also was evaluated.

RESEARCH DESIGN AND METHODS

This study followed up 28 past BGAT subjects. Half of these subjects (n = 14) received a simple booster-training program. Twelve previous control subjects also were evaluated. Booster subjects were given a BGAT diary to complete for 2 weeks before evaluation. Evaluation for all subjects included completion of a retrospective questionnaire on work and driving history, blood drawing for a glycosylated hemoglobin analysis, and having subjects estimate and measure their BG levels 50-80 times during a 3- to 4-week period during their daily routine.

RESULTS

At long-term follow-up, BGAT subjects had significantly fewer automobile crashes than control subjects. BGAT subjects receiving booster training were significantly more accurate at estimating their BG levels and were more aware of hypoglycemia. Post hoc analyses indicated that the ability to accurately estimate BG fluctuations correlated positively with follow-up glycosylated hemoglobin and the number of hypoglycemic and hyperglycemic symptoms participants demonstrated. Both BGAT and control subjects demonstrated significantly improved glycosylated hemoglobin relative to baseline measures.

CONCLUSIONS

These data suggest that BGAT has long-term benefits, which can be enhanced with booster training. Specifically, BGAT and simple booster training may result in reduction of severe hypoglycemic episodes and automobile crashes in the long term.

A potential 5-HT1A receptor antagonist: p-MPPI

A potential 5-HT1A receptor antagonist, p-MPPI, 4-(2'-methoxy-)phenyl-1-[2'-(n-2"-pyridinyl)-p-iodobenzamido-]ethy l- piperazine, was developed. The [125I]p-MPPI demonstrated high affinity and selectivity toward 5-HT1A receptors; Kd = 0.36 nM and Bmax = 264 fmol/mg of protein in rat hippocampal membrane homogenates. The binding is not sensitive to GTP (300 microM) or Gpp(NH)p (100 microM). In forskolin-stimulated adenylyl cyclase assay using rat hippocampus, p-MPPI (up to 10 microM) showed no agonist activity as compared to that of (+/-)-8-OH-DPAT. At 100 nM it completely antagonized the inhibition of forskolin-stimulated adenylyl cyclase activity produced by 100 nM of (+/-)-8-OH-DPAT. This potential 5-HT1A antagonist may provide a powerful tool for studies of the pharmacology of the 5-HT1A receptor system.

Natural history of presumed congenital Brown syndrome

OBJECTIVE

To evaluate the stability of the ocular alignment in patients with presumed congenital Brown syndrome.

DESIGN

A retrospective review of patients with Brown syndrome with an emphasis on nonsurgical cases. Follow-up of at least 1 year was required for inclusion in the study.

SETTING

Patients were selected for this study from the pediatric ophthalmology services at the Ivey Institute of Ophthalmology, London, Ontario, and the Children's Hospital of Eastern Ontario, Ottawa.

PATIENTS

A cohort of 71 patients with presumed congenital Brown syndrome. Two cases were bilateral. Eleven cases were excluded because of insufficient length of follow-up, leaving 60 patients with an average follow-up of 46 months. All patients were assessed and followed up by a pediatric ophthalmologist.

RESULTS

Of 38 patients who had no hypotropia in primary position at presentation, only two (5%) patients experienced a worsening with the development of a small vertical strabismus during the follow-up period. Six (10%) of the entire group of 60 patients experienced a complete spontaneous resolution of the deficiency in elevation at 4, 6, 8, 10, 12, and 15 years of age.

CONCLUSION

Among patients with congenital Brown syndrome, those who are orthotropic in the primary position tend to remain stable or improve over time without surgical intervention.

Interphysician agreement in the diagnosis of subtypes of acute ischemic stroke: implications for clinical trials. The TOAST Investigators

To test interphysician agreement on the diagnosis of subtype of ischemic stroke, we sent subtype definitions and 18 case summaries (clinical features and pertinent laboratory data) to 24 neurologists who have a special interest in stroke, and asked them to determine the most likely subtype diagnosis. The overall agreement was 0.64 (Kappa [K] = 0.54). Interphysician agreement was highest for the diagnoses of stroke secondary to cardioembolism (K = 0.75) or to large-artery atherosclerosis (K = 0.69). Individual physicians varied widely; four agreed with the consensus diagnosis in all 18 cases, while six others disagreed with the consensus diagnosis in three to five cases. Our level of interphysician agreement is greater than that reported in other studies and was substantial. However, despite using subtype definitions and being given extensive information often not available in the acute setting, physicians still disagree about the etiology of stroke, particularly in regard to stroke due to small-artery occlusion or of undetermined etiology. Physicians seem reluctant not to attribute stroke to a specific etiology. The uncertainty about subtype diagnosis will affect interpretation of the results of clinical trials in patients selected by the subtype of ischemic stroke and also suggests that results of treatment as affected by subtype should be cautiously interpreted unless efforts to assure uniformity are included in the trial's operations. Refinement of algorithms for determining subtype of ischemic stroke do improve interphysician agreement. Such criteria should be applied strictly, and trials should include measures to assure the most uniform diagnosis of stroke subtype possible.

Driving decrements in type I diabetes during moderate hypoglycemia

Diabetic hypoglycemia produces cognitive-motor slowing, which is assumed to increase risk of automobile crashes. This study investigated driving decrements during and after hypoglycemia, and the patients' awareness of driving decrements. We used a randomized, single-blind, crossover design and conducted the study at the University of Virginia's General Clinical Research Center. We studied a volunteer sample of 27 consecutive adult type I diabetic patients who responded to newspaper ads. Two dropped out (final n = 25). Mean age (+/- SD) was 35.9 +/- 14 yr. Diabetes history was 14.6 +/- 10.5 yr, with HbA1 of 10.8 +/- 2.9%. Driving experience was 19 +/- 13.2 yr. Participants drove a state-of-the-art driving simulator on two consecutive days: Control day involved four euglycemia (mean blood glucose, 6.3 +/- 0.89 mM) driving tests; experimental day involved testing at euglycemia, mild hypoglycemia (mean blood glucose, 3.6 +/- 0.33 mM), moderate hypoglycemia (mean blood glucose, 2.6 +/- 0.28 mM), and again at euglycemia. Patients were blind to blood glucose manipulations and levels. Driving performance was not disrupted at mild hypoglycemia nor after recovery from moderate hypoglycemia. Moderate hypoglycemia disrupted steering, causing more swerving (P < 0.03), spinning (P < 0.03), time over midline (P < 0.05), and time off road (P < 0.01). It also resulted in an apparent compensatory slowing, with more very slow driving (P < 0.04). Global driving performance decrements were observed in 35% of the patients, only 50% of whom stated they would not drive under similar conditions. Driving decrements were unrelated to demographic, disease, or driving history variables.(ABSTRACT TRUNCATED AT 250 WORDS)

Cholate solubilization of liver microsomal membrane components which promote NADPH-supported lipid peroxidation

NADPH-supported lipid peroxidation monitored by malondialdehyde (MDA) production in the presence of ferric pyrophosphate in liver microsomes was inactivated by heat treatment or by trypsin and the activity was not restored by the addition of purified NADPH-cytochrome P450 reductase (FPT). The activity was differentially solubilized by sodium cholate from microsomes, and the fraction solubilized between 0.4 and 1.2% sodium cholate was applied to a Sephadex G-150 column and subfractionated into three pools, A, B, and C. MDA production was reconstituted by the addition of microsomal lipids and FPT to specific fractions from the column, in the presence of ferric pyrophosphate and NADPH. Pool B, after removal of endogenous FPT, was highly active in catalyzing MDA production and the disappearance of arachidonate and docosahexaenoate, and this activity was abolished by heat treatment and trypsin digestion, but not by carbon monoxide. The rate of NADPH-supported lipid peroxidation in the reconstituted system containing fractions pooled from Sephadex G-150 columns was not related to the content of cytochrome P450. p-Bromophenylacylbromide, a phospholipase A2 inhibitor, inhibited NADPH-supported lipid peroxidation in both liver microsomes and the reconstituted system, but did not block the peroxidation of microsomal lipid promoted by iron-ascorbate or ABAP systems. Another phospholipase A2 inhibitor, mepacrine, poorly inhibited both microsomal and pool-B'-promoted lipid peroxidation, but did block both iron-ascorbate-driven and ABAP-promoted lipid peroxidation. The phospholipase A2 inhibitor chlorpromazine, which can serve as a free radical quencher, blocked lipid peroxidation in all systems. The data presented are consistent with the existence of a heat-labile protein-containing factor in liver microsomes which promotes lipid peroxidation and is not FPT, cytochrome P450, or phospholipase A2.

Studies of Org 10172 in patients with acute ischemic stroke. TOAST Study Group

This report presents data from pilot studies of Org 10172 in the management of patients with acute ischemic stroke. The studies have established a potentially optimal dosage and treatment regimen and have provided information for the development of a large randomized trial. The trial of Org 10172 in acute stroke treatment is now underway in the United States.