A Fusion Algorithm Based on a Constant Velocity Model for Improving the Measurement of Saccade Parameters with Electrooculography.

Electrooculography (EOG) serves as a widely employed technique for tracking saccadic eye movements in a diverse array of applications. These encompass the identification of various medical conditions and the development of interfaces facilitating human-computer interaction. Nonetheless, EOG signals are often met with skepticism due to the presence of multiple sources of noise interference. These sources include electroencephalography, electromyography linked to facial and extraocular muscle activity, electrical noise, signal artifacts, skin-electrode drifts, impedance fluctuations over time, and a host of associated challenges. Traditional methods of addressing these issues, such as bandpass filtering, have been frequently utilized to overcome these challenges but have the associated drawback of altering the inherent characteristics of EOG signals, encompassing their shape, magnitude, peak velocity, and duration, all of which are pivotal parameters in research studies. In prior work, several model-based adaptive denoising strategies have been introduced, incorporating mechanical and electrical model-based state estimators. However, these approaches are really complex and rely on brain and neural control models that have difficulty processing EOG signals in real time. In this present investigation, we introduce a real-time denoising method grounded in a constant velocity model, adopting a physics-based model-oriented approach. This approach is underpinned by the assumption that there exists a consistent rate of change in the cornea-retinal potential during saccadic movements. Empirical findings reveal that this approach remarkably preserves EOG saccade signals, resulting in a substantial enhancement of up to 29% in signal preservation during the denoising process when compared to alternative techniques, such as bandpass filters, constant acceleration models, and model-based fusion methods.

Efficacy of Chest CT for COVID-19 Pneumonia Diagnosis in France.

Background The role and performance of chest CT in the diagnosis of the coronavirus disease 2019 (COVID-19) pandemic remains under active investigation. Purpose To evaluate the French national experience using chest CT for COVID-19, results of chest CT and reverse transcription polymerase chain reaction (RT-PCR) assays were compared together and with the final discharge diagnosis used as the reference standard. Materials and Methods A structured CT scan survey (NCT04339686) was sent to 26 hospital radiology departments in France between March 2, 2020, and April 24, 2020. These dates correspond to the peak of the national COVID-19 epidemic. Radiology departments were selected to reflect the estimated geographic prevalence heterogeneities of the epidemic. All symptomatic patients suspected of having COVID-19 pneumonia who underwent both initial chest CT and at least one RT-PCR test within 48 hours were included. The final discharge diagnosis, based on multiparametric items, was recorded. Data for each center were prospectively collected and gathered each week. Test efficacy was determined by using the Mann-Whitney test, Student t test, χ2 test, and Pearson correlation coefficient. P < .05 indicated a significant difference. Results Twenty-six of 26 hospital radiology departments responded to the survey, with 7500 patients entered; 2652 did not have RT-PCR test results or had unknown or excess delay between the RT-PCR test and CT. After exclusions, 4824 patients (mean age, 64 years ± 19 [standard deviation], 2669 male) were included. With final diagnosis as the reference, 2564 of the 4824 patients had COVID-19 (53%). Sensitivity, specificity, negative predictive value, and positive predictive value of chest CT in the diagnosis of COVID-19 were 2319 of 2564 (90%; 95% CI: 89, 91), 2056 of 2260 (91%; 95% CI: 91, 92), 2056 of 2300 (89%; 95% CI: 87, 90), and 2319 of 2524 (92%; 95% CI: 91, 93), respectively. There was no significant difference for chest CT efficacy among the 26 geographically separate sites, each with varying amounts of disease prevalence. Conclusion Use of chest CT for the initial diagnosis and triage of patients suspected of having coronavirus disease 2019 was successful. © RSNA, 2021 Online supplemental material is available for this article.

Succinct colored de Bruijn graphs.

MOTIVATION: In 2012, Iqbal et al. introduced the colored de Bruijn graph, a variant of the classic de Bruijn graph, which is aimed at 'detecting and genotyping simple and complex genetic variants in an individual or population'. Because they are intended to be applied to massive population level data, it is essential that the graphs be represented efficiently. Unfortunately, current succinct de Bruijn graph representations are not directly applicable to the colored de Bruijn graph, which requires additional information to be succinctly encoded as well as support for non-standard traversal operations. RESULTS: Our data structure dramatically reduces the amount of memory required to store and use the colored de Bruijn graph, with some penalty to runtime, allowing it to be applied in much larger and more ambitious sequence projects than was previously possible. AVAILABILITY AND IMPLEMENTATION: https://github.com/cosmo-team/cosmo/tree/VARI. CONTACT: martin.muggli@colostate.edu. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.

Data analysis of diagnostic accuracies in 12-lead electrocardiogram interpretation by junior medical fellows.

BACKGROUND: The electrocardiogram (ECG) is the most commonly used diagnostic procedure for assessing the cardiovascular system. The aim of this study was to compare ECG diagnostic skill among fellows of cardiology and of other internal medicine specialties (non-cardiology fellows). METHODS: A total of 2900 ECG interpretations were collected. A set of 100 clinical 12-lead ECG tracings were selected and classified into 12 diagnostic categories. The ECGs were evaluated by 15 cardiology fellows and of 14 non-cardiology fellows. Diagnostic interpretations were classified as (1) correct, (2) almost correct, (3) incorrect, and (4) dangerously incorrect. Multivariate logistic regression was used to assess confounding factors and to determine the odds ratios for the months of experience, age, sex, and the distinction between cardiology and non-cardiology fellows. RESULTS: The mean rate of correct diagnoses by cardiology vs. non-cardiology fellows was 48.9±8.9% vs. 35.9±8.0% (p=0.001; 70.1% vs. 55.0% for the aggregate of 'correct' and 'almost correct' diagnoses). There were 10.2±5.6% of interpretations classified as 'dangerously incorrect' by cardiology fellows vs. 16.3±5.0% by non-cardiology fellows (p=0.008). The cardiology fellows achieved statistically significantly greater diagnostic accuracy in 7 out of the 12 diagnostic classes. In multivariable logistic regression, the distinction between cardiology and non-cardiology fellows was the only independent statistically significant (p<0.001) predictor of whether the reader is likely correct or incorrect. Being a non-cardiology fellow reduced the probability of correct classification by 42% (odds ratio [95% confidence interval]: 0.58 [0.50; 0.68]). CONCLUSIONS: Although cardiology fellows out-performed the others, skills in ECG interpretation were found not adequately proficient. A comprehensive approach to ECG education is necessary. Further studies are needed to evaluate proper methods of training, testing, and continuous medical education in ECG interpretation.

Recent Advances in PRRS Virus Receptors and the Targeting of Receptor-Ligand for Control.

Cellular receptors play a critical role in viral infection. At least seven cellular molecules have been identified as putative viral entry mediators for porcine reproductive and respiratory syndrome virus (PRRSV). Accumulating data indicate that among these candidates, CD163, a cysteine-rich scavenger receptor on macrophages, is the major receptor for PRRSV. This review discusses the recent advances and understanding of the entry of PRRSV into cells, viral pathogenesis in CD163 gene-edited swine, and CD163 as a potential target of receptor-ligand for the control of PRRS.

Transferability of running and cycling training zones in triathletes: implications for steady-state exercise.

The primary objective of this study was to determine whether physiological measurements obtained from one mode of testing and training could be applied to another mode, as in prescribing heart rate (HR) zone training from cyling to running. Secondary objectives were 1) to assess the validity of applying data from incremental testing to steady-state exercise, and 2) to compare breakpoint in respiratory rate (RR) with the conventional method of anaerobic threshold (AT) breakpoint, the ventilatory equivalent for oxygen VE/VO2). Sixteen experienced triathletes performed VO2max testing on a cycle ergometer (CE) and treadmill (TM). In addition, a 30-minute time trial (TT) was performed on a CE. No significant differences were observed between modes of testing for VO2max (CE = 68.4 +/- 11.1 mlxkgxmin, TM = 69.0 +/- 13.2 mlxkgxmin), maximum HR (CE = 177.1 +/- 6.1 bpm, TM = 178.1 +/- 7.4 bpm), or AT (CE AT HR = 153.9 +/- 10.5 bpm, TM AT HR = 157.0 +/- 9.5 bpm). Although the mean difference in AT HR was small (3.1 bpm), a small correlation coefficient (0.321) between the AT for the 2 testing modes resulted in a large total error (TE = 12.1 bpm), indicating limited practical application of training zones between modes of testing. Mean TT HR and mean TT RR were significantly greater than mean AT HR (159.4 +/- 8.9 vs. 153.9 +/- 10.5 bpm) and mean AT RR (37.8 +/- 6.0 vs. 32.4 +/- 3.2 breaths per minute) because of significant "drift" in these 2 variables over time, whereas TT watts and AT watts were not significantly different (249.1 +/- 47.8 vs. 240.6 +/- 71.1 W). Finally, a significant difference and large TE (9.0 bpm) betweenVE/VO2 AT HR and the RR AT HR (153.9 +/- 10.5 and 158.4 +/- 10.0 bpm) may preclude the practical use of the RR breakpoint. From the results of this study, it is recommended that the triathlete perform sport-specific testing to assess training zones for cycling and running. In addition, because both HR and RR "drift" upward with steady-state exercise, AT RR and AT HR determined by incremental testing underestimate steady-state HR and RR. For this reason, monitoring wattage during steady-state exercise may be more appropriate than monitoring HR and RR.

Can body mass index predict percent body fat and changes in percent body fat with weight loss in bariatric surgery patients?

The primary objective of this study was to assess the validity of body mass index (BMI) in predicting percent body fat and changes in percent body fat with weight loss in bariatric surgery patients. Twenty-two bariatric patients (17 female, five male) began the study designed to include 12 months of testing, including data collection within 1 week presurgery and 1 month, 3 months, 6 months, and 1 year postsurgery. Five female subjects were lost to the study between 6 months and 12 months postsurgery, resulting in 17 subjects (12 female, five male) completing the 12 months of testing. Variables measured in the study included height, weight, percent fat (% fat) by hydrostatic weighing, lean mass, fat mass, and basal metabolic rate. Regression analyses predicting % fat from BMI yielded the following results: presurgery r = 0.173, p = 0.479, standard error of estimate (SEE) = 3.86; 1 month r = 0.468, p = 0.043, SEE = 4.70; 3 months r = 0.553, p = 0.014, SEE = 6.2; 6 months r = 0.611, p = 0.005, SEE = 5.88; 12 months r = 0.596, p = 0.007, SEE = 7.13. Regression analyses predicting change in % fat from change in BMI produced the following results: presurgery to 1 month r = -0.134, p = 0.583, SEE = 2.44%; 1-3 months r = 0.265, p = 0.272, SEE = 2.36%; 3-6 months r = 0.206, p = 0.398, SEE = 3.75%; 6-12 months r = 0.784, p = 0.000, SEE = 3.20. Although some analyses resulted in significant correlation coefficients (p < 0.05), the relatively large SEE values would preclude the use of BMI in predicting % fat or change in % fat with weight loss in bariatric surgery patients.

Enrichment allows identification of diverse, rare elements in metagenomic resistome-virulome sequencing.

BACKGROUND: Shotgun metagenomic sequencing is increasingly utilized as a tool to evaluate ecological-level dynamics of antimicrobial resistance and virulence, in conjunction with microbiome analysis. Interest in use of this method for environmental surveillance of antimicrobial resistance and pathogenic microorganisms is also increasing. In published metagenomic datasets, the total of all resistance- and virulence-related sequences accounts for < 1% of all sequenced DNA, leading to limitations in detection of low-abundance resistome-virulome elements. This study describes the extent and composition of the low-abundance portion of the resistome-virulome, using a bait-capture and enrichment system that incorporates unique molecular indices to count DNA molecules and correct for enrichment bias. RESULTS: The use of the bait-capture and enrichment system significantly increased on-target sequencing of the resistome-virulome, enabling detection of an additional 1441 gene accessions and revealing a low-abundance portion of the resistome-virulome that was more diverse and compositionally different than that detected by more traditional metagenomic assays. The low-abundance portion of the resistome-virulome also contained resistance genes with public health importance, such as extended-spectrum betalactamases, that were not detected using traditional shotgun metagenomic sequencing. In addition, the use of the bait-capture and enrichment system enabled identification of rare resistance gene haplotypes that were used to discriminate between sample origins. CONCLUSIONS: These results demonstrate that the rare resistome-virulome contains valuable and unique information that can be utilized for both surveillance and population genetic investigations of resistance. Access to the rare resistome-virulome using the bait-capture and enrichment system validated in this study can greatly advance our understanding of microbiome-resistome dynamics.

Body composition and metabolic changes following bariatric surgery: effects on fat mass, lean mass and basal metabolic rate: six months to one-year follow-up.

BACKGROUND: With the failure of traditional weight loss plans, bariatric surgery has become the treatment of choice for morbid obesity. The primary objective of this study was to track body composition and metabolic changes for 1 year following bariatric surgery. METHODS: 19 bariatric patients (14 female, 5 male) began the study and completed 12 months of testing, which included data collection within 1 week preoperatively and 1, 3, 6 and 12 months postoperatively. 2 female subjects were lost to the study between 6 months and 1 year, resulting in 17 subjects (12 female, 5 male) completing the entire 12-month follow-up. Variables measured in this study included weight, lean body mass (LBM), fat mass (FM), % body fat and basal metabolic rate (BMR). RESULTS: Analysis of variance (ANOVA) using the general linear model indicated significant (P<.05) losses for weight, FM, and % fat for all time periods. Significant losses in LBM were observed in all time periods except 6-12 months, where no change in LBM (60.6 vs 61.1 kg) was observed. A significant decrease (P<.05) in BMR (2091 vs 1758) was observed only from pre-surgery to 1 month post-surgery. Thereafter, there was no significant change in BMR (1758 vs 1647 vs 1651 vs 1674) respectively. Changes in LBM were correlated with changes in BMR at both 6-12 months (r=.545, P=.024) and preoperatively to 12 months postoperatively (r=.608, P=.01). There were no significant changes in the BMR/LBM ratio over the 12-month period (28.3 vs 25.0 vs 27.3 vs 27.2 vs 27.4), indicating no adaptation of the body to an energy-conserving mechanism. CONCLUSION: Bariatric surgery appears to have been highly successful over the 12-month follow-up period, with 50.9 kg weight loss, 38.3 kg (75.2%) FM loss, and 12.6 kg (24.8%) LBM loss. The 417 kcal loss in BMR (2091 to 1674), while significant, was not greater than what would be predicted from loss of LBM.

Body composition and metabolic changes following bariatric surgery: effects on fat mass, lean mass and basal metabolic rate.

BACKGROUND: Bariatric surgery has become the method of choice for weight loss in severely obese patients. While the incidence of obesity and its co-morbidities have been well-documented, less is known about the outcomes of the surgery as it relates to body composition and metabolic changes. METHODS: 19 bariatric surgery patients (14 female, 5 male) were assessed for basal metabolic rate (BMR), percent fat, fat mass, and lean body mass (LBM) just prior to surgery and at 1, 3 and 6 months after surgery. RESULTS: Analysis of Variance (ANOVA) using the general linear model indicated significant changes in all measures of body composition for each time period. Linear regression was developed for each of these measures. Of the 39.7-kg weight loss, 26.4 kg (66.5%) was fat mass loss and 13.3 kg (33.5%) was LBM loss. BMR significantly decreased from pre-surgery (2091 kcals) to 1 month post-surgery (1758 kcals), with no significant changes in subsequent time periods. Repeated measures ANOVA for the ratio of BMR/LBM indicated no significant differences for any comparison of time periods (F=2.29, P=.111), suggesting that there is no adaptation of an energy-conserving mechanism in these patients. CONCLUSION: Bariatric surgery was highly successful in inducing significant changes in body weight (39.7 kg), fat mass (26.4 kg), % body fat (7.9%) but also lean body mass (13.3 kg). The 440 kcal decrease in BMR, while significant, was not greater than expected due to significant decreases in LBM.

Respiratory Rate is a Valid and Reliable Marker for the Anaerobic Threshold: Implications for Measuring Change in Fitness.

The anaerobic threshold (AT) has been defined as the theoretical highest exercise level that can be maintained for prolonged periods. It is of practical importance to the competitive endurance athlete to measure progress and plan training programs. The primary objective of this study was to assess the reliability and validity of breakpoint in the respiratory rate (RR) during incremental exercise as a marker for the AT. Secondary objectives were 1) to assess the reliability of the ventilatory threshold (VE) and ventilatory equivalent (VE/VO2) breakpoint, and 2) to assess differences in these 3 methods for their potential to measure change in fitness, as measured by standard error of measurement (SEM), coefficient of variability (CV), and correlation coefficient (R). Fifteen competitive male cyclists (5 category II, 6 category III, 1 category IV, 3 category V United States Cycling Federation) completed 2 maximal oxygen consumption tests within one week on an electronically braked cycle ergometer. A repeated measures Analysis of Variance using 2x3 design (test and methods) resulted in no significant differences (F = 0.02, p = 0.978), indicating that 1)all 3 methods are reproducible, and 2) RR, when compared to VE and VE/VO2, is a valid method of assessing the anaerobic threshold. The lowest SEM, lowest CV and highest R were obtained with the VE method (SEM = 19.4 watts, CV = 6.7%, R = 0.872), compared to VE/VO2 (SEM = 21.5 watts, CV = 7.4%, R=.811) and RR (SEM = 35.3 watts, CV = 12.2%, R = 0.800). From the results of this study, it is concluded that the RR method is a valid and reliable method for detecting AT. However, due to the relatively high SEM and CV, and low R, when compared to VE and VE/VO2, its insensitivity to small changes seen in highly fit athletes would preclude its use in measuring changes in AT. It appears that either VE or VE/VO2 would be appropriate for measuring AT changes in highly fit athletes. Key PointsRespiratory rate is a valid and reliable marker of the anaerobic threshold.Due to a relatively high standard error of measurement and coefficient of variability for the respiratory rate method, use of ventilation (VE) and ventilatory equivalent for oxygen (VE/VO2 is preferred when assessing changes in anaerobic threshold.When assessing changes in maximal aerobic capacity, maximal watts has a lower standard error of measurement and coefficient of variability and is preferred over changes in maximal oxygen consumption.

Intra- and inter-observer reliability in selection of the heart rate deflection point during incremental exercise: comparison to a computer-generated deflection point.

This study was designed to 1) determine the relative frequency of occurrence of a heart rate deflection point (HRDP), when compared to a linear relationship, during progressive exercise, 2) measure the reproducibility of a visual assessment of a heart rate deflection point (HRDP), both within and between observers 3) compare visual and computer-assessed deflection points. Subjects consisted of 73 competitive male cyclists with mean age of 31.4 ± 6.3 years, mean height 178.3 ± 4.8 cm. and weight 74.0 ± 4.4 kg. Tests were conducted on an electrically-braked cycle ergometer beginning at 25 watts and progressing 25 watts per minute to fatigue. Heart Rates were recorded the last 10 seconds of each stage and at fatigue. Scatter plots of heart rate versus watts were computer-generated and given to 3 observers on two different occasions. A computer program was developed to assess if data points were best represented by a single line or two lines. The HRDP represented the intersection of the two lines. Results of this study showed that 1) computer-assessed HRDP showed that 44 of 73 subjects (60.3%) had scatter plots best represented by a straight line with no HRDP 2)in those subjects having HRDP, all 3 observers showed significant differences(p = 0.048, p = 0.007, p = 0.001) in reproducibility of their HRDP selection. Differences in HRDP selection were significant for two of the three comparisons between observers (p = 0.002, p = 0.305, p = 0.0003) Computer-generated HRDP was significantly different than visual HRDP for 2 of 3 observers (p = 0.0016, p = 0.513, p = 0.0001). It is concluded that 1) HRDP occurs in a minority of subjects 2) significant differences exist, both within and between observers, in selection of HRDP and 3) differences in agreement between visual and computer-generated HRDP would indicate that, when HRDP exists, it should be computer-assessed.

A usability evaluation of medical software at an expert conference setting.

INTRODUCTION: A usability test was employed to evaluate two medical software applications at an expert conference setting. One software application is a medical diagnostic tool (electrocardiogram [ECG] viewer) and the other is a medical research tool (electrode misplacement simulator [EMS]). These novel applications have yet to be adopted by the healthcare domain, thus, (1) we wanted to determine the potential user acceptance of these applications and (2) we wanted to determine the feasibility of evaluating medical diagnostic and medical research software at a conference setting as opposed to the conventional laboratory setting. METHODS: The medical diagnostic tool (ECG viewer) was evaluated using seven delegates and the medical research tool (EMS) was evaluated using 17 delegates that were recruited at the 2010 International Conference on Computing in Cardiology. Each delegate/participant was required to use the software and undertake a set of predefined tasks during the session breaks at the conference. User interactions with the software were recorded using screen-recording software. The 'think-aloud' protocol was also used to elicit verbal feedback from the participants whilst they attempted the pre-defined tasks. Before and after each session, participants completed a pre-test and a post-test questionnaire respectively. RESULTS: The average duration of a usability session at the conference was 34.69 min (SD=10.28). However, taking into account that 10 min was dedicated to the pre-test and post-test questionnaires, the average time dedication to user interaction of the medical software was 24.69 min (SD=10.28). Given we have shown that usability data can be collected at conferences, this paper details the advantages of conference-based usability studies over the laboratory-based approach. For example, given delegates gather at one geographical location, a conference-based usability evaluation facilitates recruitment of a convenient sample of international subject experts. This would otherwise be very expensive to arrange. A conference-based approach also allows for data to be collected over a few days as opposed to months by avoiding administration duties normally involved in laboratory based approach, e.g. mailing invitation letters as part of a recruitment campaign. Following analysis of the user video recordings, 41 (previously unknown) use errors were identified in the advanced ECG viewer and 29 were identified in the EMS application. All use errors were given a consensus severity rating from two independent usability experts. Out of a rating scale of 4 (where 1=cosmetic and 4=critical), the average severity rating for the ECG viewer was 2.24 (SD=1.09) and the average severity rating for the EMS application was 2.34 (SD=0.97). We were also able to extract task completion rates and times from the video recordings to determine the effectiveness of the software applications. For example, six out of seven tasks were completed by all participants when using both applications. This statistic alone suggests both applications already have a high degree of usability. As well as extracting data from the video recordings, we were also able to extract data from the questionnaires. Using a semantic differential scale (where 1=poor and 5=excellent), delegates highly rated the 'responsiveness', 'usefulness', 'learnability' and the 'look and feel' of both applications. CONCLUSION: This study has shown the potential user acceptance and user-friendliness of the novel EMS and the ECG viewer applications within the healthcare domain. It has also shown that both medical diagnostic software and medical research software can be evaluated for their usability at an expert conference setting. The primary advantage of a conference-based usability evaluation over a laboratory-based evaluation is the high concentration of experts at one location, which is convenient, less time consuming and less expensive.

Building the nest: reworking adolescent development in adult recovery from addiction.

Using an extended case vignette, the author explores addiction, specifically compulsive gambling and substance abuse, from several psychoanalytic perspectives. Addiction/compulsive behavior is explained as a strategy for managing loss at key developmental stages. The concept of trauma repetition is utilized to understand both the repetitious nature of chronic addiction, and the trauma that underlies it. The process of recovery is chronicled through the therapeutic relationship. A classic children's story is referred to as it threads through the narrative.

Do hockey players need aerobic fitness? Relation between VO2max and fatigue during high-intensity intermittent ice skating.

The primary objective of this study was to assess the relationship between aerobic capacity, as measured by the VO(2)max test, and recovery from high-intensity intermittent exercise. Eleven female collegiate hockey players agreed to participate. Subjects skated 5 1-lap intervals around the hockey rink at maximal intensity with a 30-second recovery period between skates. The VO(2)max test was performed on a motor-driven treadmill after a modified Bruce protocol. A fatigue index was calculated by measuring the total increase in skate time from trial 1 to trial 5. This fatigue index was then correlated to VO(2)max. This correlation coefficient (-0.422) was not significant (p > 0.05) and indicated that only 17.8% of the variance in VO(2)max could be explained by the fatigue index. It was concluded that ability to recover from high-intensity intermittent exercise is not related to aerobic capacity. Coaches and trainers probably do not need to include aerobic training in their practices, because the high-intensity interval training commonly seen in hockey training also improves aerobic capacity, as reflected in the high VO(2)max values of these subjects.

A comparative study of sociocultural factors and young adults' smoking in two Midwestern communities.

Young adults were the only age group to defy the downward trend in cigarette use seen in the 1980s and 1990s. To help explain this phenomenon, we conducted an exploratory study to examine the association between the sociocultural contexts of young adults' everyday lives and their smoking attitudes and behaviors. "Context" was operationalized by (a) including students and nonstudents in the study population, and (b) selecting two distinctly different areas of Minnesota for examination. The study sites were Hibbing and environs (Range), the sparsely populated hub of the state's once-thriving iron ore industry, and the Twin Cities metropolitan area (Metro), center of state government, finance, transportation, education, and industry. This report focuses on the first phase of the study, which consisted of a computer-assisted telephone interview of 995 randomly selected young adults, aged 18-24. Approximately equal numbers of students and nonstudents were selected from each site. Exploratory factor analysis yielded four distinct scales related to alcohol consumption and partying (Drinking Behavior), the social attractiveness and utility of smoking (Social Utility), outdoor recreation (Outdoor Rec), and media use and hours of free time. We decided not to use the media and free time scale, however, because of its low Cronbach alpha (.42). We used polynomial logistic regression to evaluate the association between smoking status, gender, student status, location (Range vs. Metro), and the three retained scales. Results indicated that living on the Iron Range (OR = 2.6), being female (OR = 1.3), and scoring higher on the Social Utility scale (OR = 3.06) increased the risk of smoking, whereas being a student (OR = 0.53) decreased the risk substantially.

The hyaluronan receptor for endocytosis (HARE) is not CD44 or CD54 (ICAM-1).

Mammalian liver contains an endocytic, recycling receptor that mediates the clearance of hyaluronan (HA) and chondroitin sulfate from the circulation. McCourt et al. [J. Biol. Chem. 269 (1994) 30081] previously reported that this endocytic liver HA receptor was ICAM-1. In contrast, we purified this HA receptor for endocytosis (HARE) from rat liver sinusoidal endothelial cells (LECs) and obtained two novel large proteins [Zhou et al., J. Biol. Chem. 274 (1999) 33831]. The goal of the present study was to clarify this inconsistency and determine whether CD44, which is also an HA receptor, or ICAM-1 (CD54) is identical to, or is part of, HARE. Although isolated liver LECs contain HARE, CD44, and ICAM-1, confocal fluorescence microscopy showed that the two latter proteins have cellular distributions that are distinct from and essentially nonoverlapping with HARE. HA accumulation by cultured LECs was inhibited >98% by an antibody against HARE and unaffected by antibodies to ICAM-1 or CD44, indicating that virtually all specific HA uptake is mediated by HARE and not by ICAM-1 or CD44. Finally, no reactivity was observed against purified HARE in an ELISA-based assay using CD44 or ICAM-1 antibodies. The results confirm that the mammalian endocytic HA receptor is HARE and is not ICAM-1 or CD44.

A blocking antibody to the hyaluronan receptor for endocytosis (HARE) inhibits hyaluronan clearance by perfused liver.

Hyaluronan (HA) and chondroitin sulfate clearance from lymph and blood is mediated by the hyaluronan receptor for endocytosis (HARE). The purification and molecular cloning (Zhou, B., Weigel, J. A., Saxena, A., and Weigel, P. H. (2002) Mol. Biol. Cell 13, 2853-2868) of this cell surface receptor were finally achieved after we developed monoclonal antibodies (mAbs) against HARE. There are actually two independent isoreceptors for HA, which in rat are designated the 175-kDa HARE and 300-kDa HARE. Only one mAb (number 174) effectively and completely blocked the specific uptake of 125I-HA at 37 degrees C by rat liver sinusoidal endothelial cells. 125I-HA binding to both the 175-kDa and 300-kDa HARE proteins in a ligand blot assay was almost completely inhibited by <1 microg/ml mAb-174, whereas mouse IgG had little or no effect. MAb-174 also performed very well in Western analysis, indirect fluorescence microscopy, and a variety of immuno-procedures. Immunohistochemistry using mAb-174 localized HARE to the sinusoidal cells of rat liver, spleen, and lymph node. Western analysis using mAb-174 revealed that the sizes of both HARE glycoproteins were the same in these three tissues. 125I-HA was taken up and degraded by excised rat livers that were continuously perfused ex vivo with a recirculating medium. This HA clearance and metabolism by liver, which is a physiological function of HARE, was very effectively blocked by mAb-174 but not by mouse IgG. The results indicate that mAb-174 will be a useful tool to study the functions of HARE and the physiological significance of HA clearance.