High-throughput mapping of protein occupancy identifies functional elements without the restriction of a candidate factor approach.

There are a variety of in vivo and in vitro methods to determine the genome-wide specificity of a particular trans-acting factor. However there is an inherent limitation to these candidate approaches. Most biological studies focus on the regulation of particular genes, which are bound by numerous unknown trans-acting factors. Therefore, most biological inquiries would be better addressed by a method that maps all trans-acting factors that bind particular regions rather than identifying all regions bound by a particular trans-acting factor. Here, we present a high-throughput binding assay that returns thousands of unbiased measurements of complex formation on nucleic acid. We applied this method to identify transcriptional complexes that form on DNA regions upstream of genes involved in pluripotency in embryonic stem cells (ES cells) before and after differentiation. The raw binding scores, motif analysis and expression data are used to computationally reconstruct remodeling events returning the identity of the transcription factor(s) most likely to comprise the complex. The most significant remodeling event during ES cell differentiation occurred upstream of the REST gene, a transcriptional repressor that blocks neurogenesis. We also demonstrate how this method can be used to discover RNA elements and discuss applications of screening polymorphisms for allelic differences in binding.

Detection of Helicobacter pylori DNA in drinking water biofilms: implications for transmission in early life.

AIMS: To provide evidence of water quality as a risk factor for acquisition of Helicobacter pylori in early life, and to identify evidence for its presence within pots used to store drinking water. METHODS AND RESULTS: A prospective cohort study of 65 infants was conducted in the rural village of Keneba, The Gambia. Age of H. pylori colonization was determined and water pot biofilms were tested for H. pylori by sequencing of amplified DNA. Use of supplemental water was a strong risk factor for H. pylori colonization in infants (OR 4.71, 95% CI 1.17-22.5). DNA with 95% homology to the 16S rRNA gene of H. pylori was isolated from biofilms of water pots. CONCLUSIONS: Drinking water may be a reservoir for H. pylori in areas of the developing world where water quality is poor. Early introduction of water, particularly if stored in, or collected from contaminated sources, may be associated with an increased rate of H. pylori colonization.

Helicobacter sp. recovered from drinking water biofilm sampled from a water distribution system.

Workers examining the transmission route(s) and reservoir(s) of infection for Helicobacter pylori have postulated several environmental reservoirs for the organism, including water. Such work has, to date, concentrated on the bulk liquid in drinking water systems rather than on biofilms. Previous investigations by the authors have suggested biofilms in water distribution systems are a possible reservoir of infection. This current study comprised of an analysis of a section of cast iron mains distribution pipe removed from an urban environment in the north-east of Scotland during routine maintenance work. Immediately upon removal of the pipe section, the interior lumen was swabbed to remove the biofilm layer. Subsequent analysis for the presence of Helicobacter DNA using a nested PCR approach produced a positive result. This data provides the first evidence for the existence of Helicobacter in biofilms found in water distribution systems anywhere in the world.

Biofilms in drinking water systems: a possible reservoir for Helicobacter pylori.

A laboratory model system was utilised to investigate the persistence of Helicobacter pylori in mixed-species heterotrophic biofilms. A single-stage continuous culture vessel was linked to a modified-Robbins device (mRD) incorporating removable stainless steel coupons. The system was innoculated with H. pylori (NCTC 11637) and the fate of the organism monitored by polymerase chain reaction (PCR) analysis. Helicobacter pylori was detected in biofilm material for a period of up to 192 h. Theoretical washout would have occurred at around 48 h thus detection of H. pylori for a prolonged period after theoretical washout suggested that the organism possessed the ability to persist in the mixed-species heterotrophic biofilm. Preliminary studies using heat-inactivated H. pylori showed that the organism was not detected in biofilm material at any time post-challenge suggesting that the persistence of H. pylori in such material was a phenomenon requiring the organism to be in a viable state. Further investigations to assess the biological basis for the association of H. pylori with drinking water biofilms and the risk that this may pose to public health are being undertaken.

Factors predicting employment 1 year after traumatic spine fracture.

STUDY DESIGN: This prospective cohort study evaluates the employment status of 489 persons after traumatic spine fracture. OBJECTIVES: To determine the rate, type, and predictors of employment 1 year after traumatic spine fracture. SUMMARY OF BACKGROUND DATA: The limited existing literature regarding employment after spine fracture reports variable return-to-work rates, tends to be retrospective, and generally evaluates a limited number of predictor factors at a time. METHODS: Four hundred eighty-nine persons ranging in age from 15 to 64 years who had experienced a spine fracture were assessed by a single examiner at hospital discharge and 1 year postinjury. Employment status and type. discharge neural and functional status, pain level, demographics, injury level and severity, and early treatment details were evaluated. RESULTS: At 1 year postinjury, 54% of subjects were working. A higher percentage of the employed were working part time and for fewer weeks per year than preinjury. A higher percentage were working at unskilled clerical, sales, or service jobs than preinjury. The significant positive (+) and negative (-) predictors of employment were (from strongest to weakest); worked in year previous to injury (+); employed at time of injury (+); Worker's compensation Board coverage (-); spinal fracture surgery (+); high-level spine fracture (-); pain (-); Functional Independence Measure score (+); and days of stay in intensive care unit and spinal unit (-). CONCLUSIONS: For the first year after spinal fracture, unemployment is common. Those who do return to work are more likely to modify the amount and type of work they do and to have been employed preinjury.

Position of the cervical vertebrae during helmet removal and cervical collar application in football and hockey.

There is lack of consensus among prehospital personnel (athletic therapists, paramedics, sport physiotherapists) concerning specific aspects of initial care and assessment of injured athletes presenting signs and symptoms of a cervical spine injury (CSI). In instances of serious injury involving the head and/or spine, complicated by altered levels of consciousness, protective equipment such as helmets and shoulder pads may provide a hinderance to prompt, safe and efficient management. Specifically, there is disagreement concerning the need or advisability of removing protective head gear, as in the case of football and hockey athletes. Using the technique of fluoroscopy, the cervical spine displacement of 21 male football and hockey athletes was determined while wearing protective shoulder pads and protective head equipment at the following times (a) during helmet removal, (b) during cervical collar application, and (c) as the helmetless head was allowed to rest. Subsequent frame-by-frame video arthokinematic analysis, using computer-assisted digitization, showed significant alterations in the position of adjacent cervical vertebrae during helmet removal, cervical collar application, and head rest. Results suggest that stabilization and transportation of football and hockey athletes with suspected CSI in their respective protective equipment is recommended in order to reduce the risk of further trauma by unnecessary cervical spine motion.

Shoulder abduction strength measurement in football players: reliability and validity of two field tests.

Musculoskeletal and neurologic injuries affecting shoulder strength are common in contact sports. Full-strength recovery is desired before resumption of competition. On-field assessment of shoulder strength is usually done by manual muscle testing, which lacks sensitivity and reliability. Our objective was to determine the reliability and validity of two field instruments capable of quantifying shoulder abduction strength. Twenty junior football players underwent bilateral isokinetic (60 degrees/s) and isometric shoulder abduction strength measurements using a Cybex 340 isokinetic dynamometer. Test-retest measurements of both shoulders of each player were made using strain gauge (SG) and handheld dynamometer (HHD) instruments. Players were tested during rested and competition conditions. Within and between session reliabilities were calculated using the intraclass coefficient, and validity was assessed using Pearson's correlation coefficient. Overall reliability for each device was calculated using Lisrel analysis. SG was found to be superior to HHD in overall reliability and validity. Within-session reliability in the rested and competition states was 0.75 and 0.78, respectively, for SG and 0.60 and 0.81, respectively, for HHD. Between-session reliability in the rested and competition states dropped to 0.51 and 0.63, respectively, for SG and 0.55 and 0.70, respectively, for HHD. Validity was 0.41 and 0.70 for SG when correlated with Cybex at 0 degree and 60 degrees/s respectively. Validity for HHD was 0.28 and 0.42 for Cybex speeds of 0 degree and 60 degrees/s, respectively. SG reliability and validity were similar when testing was done one shoulder at a time or both shoulders concurrently.(ABSTRACT TRUNCATED AT 250 WORDS)

Postfabrication exposure of gap-type bandpass filters in broadly chirped fiber gratings.

High efficiency in-fiber bandpass filters with arbitrary passband/stop-band combinations have been produced successfully with an UV postfabrication exposure technique in broadly chirped fiber gratings. By further concatenating such a bandpass filter with two additional chirped gratings we achieved a finesse as high as 220 for a 36-nm stop band. This new approach exhibits great advantages in controlling precisely the profiles of bandpass filters in terms of stop-band width, transmission wavelength and linewidth, and spacing of passbands.

Shoulder pain in wheelchair athletes. The role of muscle imbalance.

Shoulder rotator cuff impingement syndrome is a common and disabling problem for the wheelchair athlete. In this study we investigated the role of shoulder strength imbalance as a factor for the development of this syndrome. Nineteen paraplegic male athletes underwent clinical and isokinetic examination of both shoulders with peak torque values measured in abduction, adduction, and internal and external rotation. Twenty athletic, able-bodied men without shoulder problems were tested as controls. Ten (26%) of the paraplegic athletes had rotator cuff impingement syndrome. The results of the isokinetic testing demonstrated that 1) the paraplegics' shoulders were stronger than the controls in all directions (P < 0.05); 2) the strength ratio of abduction: adduction was higher for paraplegic athletes (P < 0.05); 3) paraplegics' shoulders with rotator cuff impingement syndrome were weaker in adduction and external and internal rotation than the paraplegic athletes without impingement syndrome (P < 0.05); and 4) paraplegics' shoulders with rotator cuff impingement syndrome had higher abduction:adduction and abduction:internal rotation strength ratios than the shoulders of paraplegics without impingement syndrome (P < 0.05). We concluded that shoulder muscle imbalance, with comparative weakness of the humeral head depressors (rotators and adductors), may be a factor in the development and perpetuation of rotator cuff impingement syndrome in wheelchair athletes.

Incomplete neural deficits in thoracolumbar and lumbar spine fractures. Reliability of Frankel and Sunnybrook scales.

Because neural status is used both as a treatment determiner and outcome measure, a universal, reliable scale is required. Experienced personnel, provided with concise definitions, demonstrated high inter-rater reliability of Frankel and Sunnybrook scales (Pearson correlation coefficients 0.71-0.91), with 94-100% intra-rater agreement. Both scales correspond to total sensory and motor function but are insensitive to walking and bladder function. Frankel's wide clinical use, reliability, and simplicity identify it to be the preferred measurement system until a better alternative is developed. Discussion of neural status must include description of bladder and walking function.

Anterior compartment pressures in cross-country skiers. A comparison of classic and skating skis.

This paper compares the pressure changes in the anterior compartment of the leg when cross-country skiing using the skating method on either skating skis or classic skis. Intracompartmental pressures of the right leg were recorded from the tibialis anterior muscle of 10 subjects at rest and 15 seconds after 10 to 12 minutes of cross-country skiing on a designated course. All subjects completed two trials on different days. In one trial, subjects used skating skis and for the other trial, classic skis were used for the skating technique. Although the average pressure increase was higher for the classic ski trials than for the skating ski trials, the difference was not significant. This finding indicates that cross-country skiers who skate on a classic ski as opposed to a shorter skating ski do not experience a significantly greater increase in their anterior compartment pressure. Thus, it appears that the type of ski used is not the most significant factor contributing to chronic compartment syndrome.

Influence of electrical stimulation on the morphological and metabolic properties of paralyzed muscle.

Selected morphological and metabolic properties of single fibers were studied in biopsy samples from the tibialis anterior of normal control and spinal cord-injured (SCI) subjects. In the SCI subjects, one muscle was electrically stimulated progressively over 24 wk, in 6-wk blocks for less than or equal to 8 h/day, while the contralateral muscle remained untreated. The percentage of fibers classified as type I [qualitative alkaline preincubation myofibrillar adenosinetriphosphatase (ATPase)] was significantly less in the unstimulated paralyzed muscles than in the muscles of normal control subjects. Electrical stimulation increased the proportion of type I fibers in the SCI subjects. For both type I and type II fibers, the cross-sectional area, activities of myofibrillar ATPase and succinate dehydrogenase, and the capillary-to-fiber ratio were also significantly less in the paralyzed muscles than in the normal control muscles. Electrical stimulation increased only the activity of succinate dehydrogenase in both fiber types of the SCI subjects. These data are discussed in relation to the electromechanical properties of the respective muscles described in an accompanying paper (J. Appl. Physiol. 72: 1393-1400, 1992). In general, the electrical stimulation protocol used in this study enhanced the oxidative capacity and endurance properties of the paralyzed muscles but had no effect on fiber size and strength.

Effect of high velocity resistance training on peak torque, cross sectional area and myofibrillar ATPase activity.

The purpose of this investigation was to determine the effect of high velocity resistance (HVR) training on peak torque (PT), cross sectional area (CSA) and myofibrillar ATPase activity of the knee extensors. HVR training was performed in a circuit on hydraulic exercise equipment, 4 times a week for 5 weeks at an angular velocity of approximately 3.14 rad.s-1. Knee extension PT was determined on a Cybex II isokinetic dynamometer and CSA of the quadriceps femoris muscle was assessed using computer tomography (CT) scanning. Muscle biopsies were obtained from the lateral quadriceps muscle and were analyzed for myofibrillar ATPase activity. Knee extension peak torque was significantly increased at 1.57, 2.09, 3.14, 3.66 and 4.19 rad.s-1. Myofibrillar ATPase activity and CSA was also significantly increased after HVR training. These findings showed that short-term high velocity resistance training enhances the in vivo torque/velocity curve especially at fast angular velocities and these changes are partly attributed to an increase in muscle CSA and activity of myofibrillar ATPase.

The effects of a reduced exercise duration taper programme on performance and muscle enzymes of endurance cyclists.

The influence of tapering on the metabolic and performance parameters in endurance cyclists was investigated. Cyclists (n = 25) trained 5 days.week-1, 60 min.day-1, at 75-85% maximal oxygen consumption (VO2max) for 8 weeks and were then randomly assigned to a taper group: 4D (4 days; n = 7), 8D (8 days; n = 6), CON (control, 4 days rest; n = 6), NOTAPER (non-taper, continued training; n = 6). Muscle biopsy specimens taken before and after training and tapering were analysed for carnitine palmityltransferase (CPT), citrate synthase, beta-hydroxyacyl CoA dehydrogenase (HOAD), cytochrome oxidase (CYTOX), lactate dehydrogenase, glycogen and protein. Significant increases in VO2max (6%), a 60-min endurance cycle test (34.5%), oxidative enzymes (77-178%), glycogen (35%) and protein (34%) occurred following training. After the taper, HOAD and CPT decreased 25% (P less than 0.05) and 26% respectively, in the CON. Post-taper CYTOX values were different (P less than 0.05) for 4D and 8D compared with CON. Muscle glycogen levels were increased (P less than 0.05) after tapering in the 4D, 8D and CON, but decreased in NOTAPER. Similarly, power output at ventilation threshold was significantly increased in the 4D (27.4 W) and 8D (27 W) groups, but decreased (22 W) in the NOTAPER. These findings suggest that tapering elicited a physiological adaptation by altering oxidative enzymes and muscle glycogen levels. Such an adaptation may influence endurance cycling during a laboratory performance test.

Effect of systemic inhibition of prostaglandin synthesis on muscle protein balance after trauma in the rat.

Anaesthetized rats were subjected to a single impact trauma to the medial aspect of the right hindlimb (gastrocnemius muscle), and were compared with sham-treated controls. For 3 days after injury, muscles of the traumatized limb showed a marked catabolic response. Muscle protein repletion commenced after day 3, however, this process was not complete until 21 days after injury. Muscles of the uninjured limb of the traumatized rats also showed a distinct catabolic response, compared with rats that were never injured, although this response was less in magnitude than that of the injured limb. At 3 days after trauma, augmented synthesis of prostaglandin (PG)E2 by muscles of the injured and uninjured limb provided evidence of a local and systemic inflammatory response. Inhibition of PG synthesis by the systemic administration of naproxen (6-methoxy-alpha-methyl-2-napthaleneacetic acid) significantly reduced the catabolic loss of muscle protein seen locally and peripherally to the injury site.

Multiple noncontiguous spine fractures.

The data from a prospective study of 508 spine injuries were reviewed to determine the incidence of multiple noncontiguous spine fractures. All patients were examined at admission and at 1 and 2 years postinjury. This series identified 77 (15.2%) multilevel fractures. Motor vehicle accidents were the primary cause of these fractures. The incidence of neurologic injury was not significantly different between multiple noncontiguous and single fractures. Failure to use seat belts and ejection from the vehicle were the main factors associated with multiple noncontiguous spine injuries. Seven major fracture patterns were identified, which accounted for 60% of these injuries. The prognosis for multilevel spine fractures was not significantly worse that that for single-level injuries.

Spine trauma and associated injuries.

A longitudinal, prospectively gathered data base of spine trauma has been developed. A review of 508 consecutive hospital admissions identified the presence of associated injuries in 240 (47%) individuals, most frequently involving head (26%), chest (24%), or long bones (23%). Twenty-two per cent had one associated injury, 15% had two, and 10% had three or more. Most spine fractures involved the lower cervical (29%) or thoracolumbar junction (21%). Comparisons of presence or absence of associated injuries and spine fracture level showed significant differences (p less than 0.001). Eighty-two per cent of thoracic fractures and 72% of lumbar fractures had associated injuries compared to 28% of lower cervical spine fractures. While there was no significant relationship between type of associated injury and spine fracture level, those with associated injuries were less likely to have a neural deficit (p less than 0.05). After hospital admission, there were seven deaths. Early assessment and transport of spine trauma victims must be carried out with appropriate management of associated injuries. Conversely, multiple trauma victims must be handled with due regard for a possible spine fracture. The value of spinal units with specially trained personnel is emphasized.