Ingestion of swimming pool water by recreational swimmers.

The volume of water ingested by swimmers while swimming is of great interest to individuals who develop risk assessments using quantitative microbial risk assessment or epidemiological approaches. We have used chloroisocyanurate disinfected swimming pool waters to determine the amount of water swallowed by swimmers during swimming activity. The chloroisocyanurate, which is in equilibrium with chlorine and cyanuric acid in the pool water, provides a biomarker, cyanuric acid, that once swallowed passes through the body into the urine unchanged. The concentration of cyanuric acid in a 24 hour urine specimen and the concentration in pool water can be used to calculate the amount of water swallowed. Our study population of 549 participants, which was about evenly divided by gender, and young and adult swimmers, indicated that swimmers ingest about 32 mL per hour (arithmetic mean) and that children swallowed about four times as much water as adults during swimming activities. It was also observed that males had a tendency to swallow more water than females during swimming activity and that children spent about twice as much time in the water than adults.

Second fractures among older adults in the year following hip, shoulder, or wrist fracture.

UNLABELLED: We report on second fracture occurrence in the year following a hip, shoulder or wrist fracture using insurance claims. Among 273,330 people, 4.3 % had a second fracture; risk did not differ by first fracture type. Estimated adjusted second fracture probabilities may facilitate population-based evaluation of secondary fracture prevention strategies. INTRODUCTION: The purpose of this study was estimate second fracture risk for the older US population in the year following a hip, shoulder, or wrist fracture. METHODS: Observational cohort study of Medicare fee-for-service beneficiaries with an index hip, shoulder, or wrist fragility fracture in 2009. Time-to-event analyses using Cox proportional hazards models to characterize the relationship between index fracture type (hip, shoulder, wrist) and patient factors (age, gender, and comorbidity) on second fracture risk in the year following the index fracture. RESULTS: Among 273,330 individuals with fracture, 11,885 (4.3 %) sustained a second hip, shoulder or wrist fracture within one year. Hip fracture was most common, regardless of the index fracture type. Comparing adjusted second fracture risks across index fracture types reveals that the magnitude of second fracture risk within each age-comorbidity group is similar regardless of the index fracture. Men and women face similar risks with frequently overlapping confidence intervals, except among women aged 85 years or older who are at greater risk. CONCLUSIONS: Regardless of index fracture type, second fractures are common in the year following hip, shoulder or wrist fracture. Secondary fracture prevention strategies that take a population perspective should be informed by these estimates which take competing mortality risks into account.

Brain trauma exposure for American tackle football players 5 to 9 and 9 to 14 years of age.

American football helmets used by youth players are currently designed and tested to the same standards as professionals. The National Operating Committee on Standard and Safety requested research aiming at understanding the differences in brain trauma in youth American football for players aged five to nine and nine to fourteen years old to inform a youth specific American football standard. Video analysis and laboratory reconstructions of head impacts were undertaken to measure differences in head impact frequency, event types, and magnitudes of maximum principal strain (MPS) for the two age groups. Overall frequencies and frequencies for five categories of MPS representing different magnitudes of risk were tabulated. The MPS categories were very low (<0.08), low (0.08-0.169), medium (0.17-0.259), high (0.26-0.349) and very high (>0.35). Both cohorts experienced a majority of head impacts (>56%) at very low magnitude of MPS. Youth American football players aged 9-14 yrs. sustained a greater frequency of head impacts at MPS between 0.08 and 0.169 % associated with changes in brain structure and function. There were no differences in overall frequency, or in frequency of head impacts in other categories of MPS. The proportion of impacts considered injurious (MPS > 0.08) was greater in the 5-9 group (44%), than the 9-14 group (39%), and impacts above 0.35 % were only reported for the younger age group. The larger helmet-to-shoulder ratio in the younger age groups may have contributed to this finding suggesting that youth American football players under the age of nine would benefit from a child-specific football helmet.

Age of first exposure to American football and long-term neuropsychiatric and cognitive outcomes.

Previous research suggests that age of first exposure (AFE) to football before age 12 may have long-term clinical implications; however, this relationship has only been examined in small samples of former professional football players. We examined the association between AFE to football and behavior, mood and cognition in a large cohort of former amateur and professional football players. The sample included 214 former football players without other contact sport history. Participants completed the Brief Test of Adult Cognition by Telephone (BTACT), and self-reported measures of executive function and behavioral regulation (Behavior Rating Inventory of Executive Function-Adult Version Metacognition Index (MI), Behavioral Regulation Index (BRI)), depression (Center for Epidemiologic Studies Depression Scale (CES-D)) and apathy (Apathy Evaluation Scale (AES)). Outcomes were continuous and dichotomized as clinically impaired. AFE was dichotomized into <12 and ⩾12, and examined continuously. Multivariate mixed-effect regressions controlling for age, education and duration of play showed AFE to football before age 12 corresponded with >2 × increased odds for clinically impaired scores on all measures but BTACT: (odds ratio (OR), 95% confidence interval (CI): BRI, 2.16,1.19-3.91; MI, 2.10,1.17-3.76; CES-D, 3.08,1.65-5.76; AES, 2.39,1.32-4.32). Younger AFE predicted increased odds for clinical impairment on the AES (OR, 95% CI: 0.86, 0.76-0.97) and CES-D (OR, 95% CI: 0.85, 0.74-0.97). There was no interaction between AFE and highest level of play. Younger AFE to football, before age 12 in particular, was associated with increased odds for impairment in self-reported neuropsychiatric and executive function in 214 former American football players. Longitudinal studies will inform youth football policy and safety decisions.

Cerebral [18 F]T807/AV1451 retention pattern in clinically probable CTE resembles pathognomonic distribution of CTE tauopathy.

Chronic traumatic encephalopathy (CTE) is a neurodegenerative disorder most commonly associated with repetitive traumatic brain injury (TBI) and characterized by the presence of neurofibrillary tangles of tau protein, known as a tauopathy. Currently, the diagnosis of CTE can only be definitively established postmortem. However, a new positron emission tomography (PET) ligand, [18F]T807/AV1451, may provide the antemortem detection of tau aggregates, and thus various tauopathies, including CTE. Our goal was to examine [18F]T807/AV1451 retention in athletes with neuropsychiatric symptoms associated with a history of multiple concussions. Here we report a 39-year-old retired National Football League player who suffered 22 concussions and manifested progressive neuropsychiatric symptoms. Emotional lability and irritability were the chief complaints. Serial neuropsychological exams revealed a decline in executive functioning, processing speed and fine motor skills. Naming was below average but other cognitive functions were preserved. Structural analysis of longitudinally acquired magenetic resonance imaging scans revealed cortical thinning in the left frontal and lateral temporal areas, as well as volume loss in the basal ganglia. PET with [18F]florbetapir was negative for amyloidosis. The [18F]T807/AV1451 PET showed multifocal areas of retention at the cortical gray matter-white matter junction, a distribution considered pathognomonic for CTE. [18F]T807/AV1451 standard uptake value (SUV) analysis showed increased uptake (SUVr⩾1.1) in bilateral cingulate, occipital, and orbitofrontal cortices, and several temporal areas. Although definitive identification of the neuropathological underpinnings basis for [18F]T807/AV1451 retention requires postmortem correlation, our data suggest that [18F]T807/AV1451 tauopathy imaging may be a promising tool to detect and diagnose CTE-related tauopathy in living subjects.

Summary and agreement statement of the 2nd International Conference on Concussion in Sport, Prague 2004.

In November 2001, the 1st International Symposium on Concussion in Sport was held in Vienna, Austria to provide recommendations for the improvement of safety and health of athletes who suffer concussive injuries in ice hockey, football (soccer), and other sports. The 2nd International Symposium on Concussion in Sport was organised by the same group and held in Prague, Czech Republic in November 2004. It resulted in a revision and update of the Vienna consensus recommendations, which are presented here.

Stable association complex electrospray mass spectrometry for the determination of cyanuric acid.

Cyanuric acid, a suspected gastrointestinal or liver toxicant, has gained interest as a potential degradation product of triazine herbicides, such as simazine and atrazine. This paper investigates the determination of cyanuric acid by stable association complex electrospray mass spectrometry (cESI-MS). The cyanuric acid is extracted from the water through a microscale liquid-liquid extraction. The extract is evaporated to dryness, and an aqueous solution of quaternary ammonium cationic surfactant is added. When injected into the electrospray mass spectrometer, the surfactant and the cyanuric acid form a mass-selective stable association complex, which may be used for confident quantification of cyanuric acid. Several extraction solvents and surfactants were investigated. These studies provide insight into the mechanism of electrospray for the formation of these complexes, specifically with regard to the surface activity of the different surfactants and the chemistry of the surfactant-cyanuric acid complexes. From an analytical standpoint, the cESI-MS method detection limit for extraction of a 1 mL aqueous solution of cyanuric acid was 130 microg/L based on 3.14sigma(n-1) of seven replicate injections. Standard additions were used for quantification of eight aqueous samples. The cyanuric acid concentrations determined with cESI-MS were not significantly different at the 95% confidence level to those determined by conventional high-performance liquid chromatography (HPLC). A recovery of 100% from a fortified urine sample illustrates the robustness of the technique.

Magnetic field exposure during gestation: pineal and cerebral cortex serotonin in the rat.

Extremely low frequency (ELF) magnetic fields seem to have a reproducible influence on cells in transitional states, such as cells during the embryonic and early postnatal periods. Intense and continuous serotonergic synaptic growth is present during the first 2 weeks of postnatal development, paralleled by 5-HT content in the brain, so, the effect of ELF on 5-HT content in the cerebral cortex and pineal gland was determined in growing rats exposed during pregnancy, and in normal controls. The results showed a significant 5-HT increase at birth, 15 and 21 days, in the cerebral cortex. No differences were found in the pineal gland. These short MF exposures had a long term effect on cerebral cortex 5-HT, possibly starting since the fetal period. The relevance of the present findings are discussed as related to the serotonin trophic role on the brain cortex.

The prediction of common bile duct stones using a neural network.

BACKGROUND: The role of preoperative ERCP and endoscopic sphincterotomy (ES) in the diagnosis and treatment of suspected common bile duct stones (CBDS) in the laparoscopic age is controversial. The preoperative diagnosis of CBDS by ERCP and the removal of CBDS by ES are advantageous because of technical difficulties in performing laparoscopic exploration of the common bile duct. Approximately 50% of preoperative ERCP examinations are normal, however. The noninvasive diagnosis of CBDS has assumed new importance, but it has proved to be an elusive goal. Neural networks are a form of artificial computer intelligence that have been used successfully to interpret ECGs and to diagnose myocardial infarcts. The purpose of this study was to determine whether a neural network could be trained to predict CBDS accurately in patients at high risk of having duct stones. STUDY DESIGN: We trained a back-propagation neural network to predict the presence of CBDS. Retrospective data from patients who had a cholecystectomy and either a preoperative ERCP or intraoperative cholangiogram were used to build the network, and it was tested using unseen data. RESULTS: One hundred forty patients were used to train the network, and 16 patients were used to test it. The trained network was able to predict CBDS in 100% of the patients in both the training and test sets. CONCLUSIONS: Screening of high-risk patients for CBDS by neural network analysis is highly accurate. This promising new, noninvasive, and inexpensive technique can potentially decrease the need for preoperative ERCP by 50%, but additional prospective evaluation is indicated.

A multivariate analysis of factors contributing to leakage of intestinal anastomoses.

BACKGROUND: The study of anastomotic leaks is critically important to surgeons because morbidity and mortality increase many fold in the aftermath of an anastomotic disruption. Previous studies that have attempted to identify significant factors contributing to leakage of intestinal anastomoses used animal models or have analyzed retrospective data using univariate analysis. Our objective was to identify factors contributing to leakage of intestinal anastomoses. STUDY DESIGN: We conducted a retrospective, multivariate analysis of 764 patients who underwent 813 intestinal anastomoses. RESULTS: The overall rate of anastomotic leakage was 3.4 percent. No difference was found in rates of leakage among different techniques of anastomosis or among different anastomotic locations. Colonic anastomoses leaked no more frequently than anastomoses of the small intestine. Proximal fecal diversion did not decrease the frequency of leaks. Multivariate analysis identified six significant predictive variables: a serum albumin level of less than 3.0 g/L, use of corticosteroids, peritonitis, bowel obstruction, chronic obstructive pulmonary disease, and perioperative transfusion of more than 2 U packed red blood cells. The in-hospital mortality rate in patients with and without leaks was 39.3 percent and 7 percent, respectively. Multivariate analysis showed that anastomotic leaks were an independent predictor of mortality. CONCLUSIONS: Factors predictive of anastomotic leaks include chronic obstructive pulmonary disease, peritonitis, bowel obstruction, malnutrition, use of corticosteroids, and perioperative blood transfusion.

Catastrophic football injuries: 1977-1998.

The primary purpose of this study was to investigate the occurrence of catastrophic football head and spine injuries, in an attempt to reduce their frequency. We analyzed epidemiological and medical data from 1977 through 1998. Catastrophic football injuries are defined as football injuries that result in death, brain or spinal cord injury, or cranial or spinal fracture. All studied cord injuries involved the cervical region. During the period covered by this study, 118 athletes died as a direct result of participation in the skills of football, 200 football players received a permanent cervical cord injury, and 66 sustained a permanent cerebral injury. Most cervical injuries occurred to defensive players during the act of tackling. The axial loading mechanism of spinal cord injury was identified in 27% of tackling injuries. To further reduce catastrophic injuries, players must stop tackling with the head down and using the head as a battering ram; instead, players should use the shoulder for blocking and tackling. Other recommendations for reducing catastrophic injuries are presented.

Head injury in athletes.

HEAD INJURIES INCURRED during athletic endeavors have been recorded since games were first held. During the last century, our level of understanding of the types of cerebral insults, their causes, and their treatment has advanced significantly. Because of the extreme popularity of sports in the United States and worldwide, the implications of athletic head injury are enormous. This is especially true considering the current realization that mild traumatic brain injury (MTBI) or concussion represents a major health consideration with more long-ranging effects than previously thought. When considering athletic injuries, people who engage in organized sports, as well as the large number of people who engage in recreational activities, should be considered. There are 200 million international soccer players, a group increasingly recognized to be at risk for MTBI. The participation in contact sports of a large number of the population, especially youth, requires a careful and detailed analysis of injury trends and recommended treatment. There are numerous characteristics of this patient population that make management difficult, especially their implicit request to once again be subjected to potential MTBI by participating in contact sports. Recent research has better defined the epidemiological issues related to sports injuries involving the central nervous system and has also led to classification and management paradigms that help guide decisions regarding athletes' return to play. We currently have methods at our disposal that greatly assist us in managing this group of patients, including improved recognition of the clinical syndromes of MTBI, new testing such as neuropsychological assessment, radiographic evaluations, and a greater appreciation of the pathophysiology of concussive brain injury. The potential for long-term consequences of repetitive MTBI has been recognized, and we no longer consider the "dinged" states of athletic concussions to have the benign connotations they had in the past. We review the historical developments in the recognition and care of athletes with head injuries, the current theory of the pathophysiology and biomechanics of these insults, and the recommended management strategy, including return-to-play criteria.

Cerebral concussion in sport. Management and prevention.

This article explains the various stresses (tensile, compressive, and shearing) that can affect the brain, and how they may produce the different types of brain injury. The biomechanical forces and dynamics that produce coup versus contra coup injury are covered, as are the common intracranial athletic head injuries, i.e. concussion and the various intracranial haematomas (epidural, subdural, subarachnoid and intracerebral). Though less common in occurrence, because their outcome is so catastrophic, space is also devoted to the recognition, the treatment and (especially in the latter case) the prevention of the malignant brain oedema syndrome of the adolescent and the second impact syndrome of the adult. A major emphasis of this paper is the recognition of the 3 grades of cerebral concussion and the delineation of clear guidelines as to when it is safe to return to collision sports after sustaining such injuries, for the first, second or third time during a given season. Clear guidelines are also presented as to when to discontinue collision sport competition for the remainder of the season after multiple concussions. Because of the concern for the second impact syndrome, the requirement to never allow an athlete with postconcussion syndrome symptoms to return to competition is emphasised. Also covered is the prevention of head injuries, which sports are at greatest risk, and the need for additional research on the cumulative effects of concussion.

Efficacy of preadmission testing in ambulatory surgical patients.

A retrospective study was done with 325 patients who had preadmission testing prior to ambulatory surgery. At least one laboratory abnormality was noted in 84% of the patients. The serial multiple analysis (SMA)-7 was abnormal 63% of the time. Abnormalities were seen in 54% of the SMA-12 panels and 38% of the urinalyses performed. Twenty-four percent of the patients treated had an abnormal electrocardiogram (ECG). An abnormal chest roentgenogram was found in 19% of the patients. Only three (1%) patients potentially benefited from preadmission testing. Ninety-six percent of the abnormal laboratory results were ignored by the attending physicians. Therefore, we conclude that preadmission testing should be done on a selective basis. Patients older than 50 years of age should have an ECG. A hematocrit should be obtained only if major blood loss is anticipated. All other tests should be ordered based on the history and physical examination.

Stingers, transient quadriplegia, and cervical spinal stenosis: return to play criteria.

This article focuses on sports related spinal cord and nerve injuries, ranging from mild "stinger" syndrome to complete quadriplegia. Particular emphasis is placed on recommendations for return to competition after such injuries. Cervical spinal cord symptoms after a spine injury from contact sports require a more precise work up to detect cervical spinal stenosis than radiographic bone measurements alone can provide. Imaging technology such as MRI, contrast positive CT, and myelography more accurately identify true spinal stenosis and allow for safer return to play decisions.

Cerebral stroke in a semi-pro football player: a case report.

Cervical spine trauma can clearly result in neurologic injury. An unusual traumatic event is a vascular insult of the vertebral arteries, potentially leading to stroke. The vertebral arteries are vulnerable to compression at several sites in the cervical spine. The high degree of physiologic rotation at the atlanto-axial joint places the vertebral artery at risk through normal daily activities as well as following forceful trauma, including manipulative treatment. Cerebrovascular insufficiency is an uncommon but serious complication of cervical spinal manipulation, which can lead to posterior circulatory impairment. Comprehensive diagnostic studies may be required to differentiate primary intracranial pathology from cerebral symptoms secondary to vascular compromise.

Catastrophic injuries and fatalities in high school and college sports, fall 1982-spring 1988.

Direct and indirect deaths and catastrophic injuries, defined as any injury incurred during participation in a high school/college sponsored sport in which there is permanent severe functional neurological disability (nonfatal) or transient but not permanent functional neurologic disability (serious), are presented for all sports during the period of fall 1982 to spring 1988. Football contributed the greatest numbers of catastrophic injuries but also had the largest number of participants. Ice hockey, gymnastics, and wrestling are the other sports where participants are at greatest risk of catastrophic injury or death. Mechanisms of injury in each sport and corrective actions are identified and discussed. While high school and college catastrophic injuries may never be totally eliminated, they can be dramatically reduced by reliable injury data collection and analysis.

Nontraumatic sports death in high school and college athletes.

Nontraumatic deaths occur each year in organized high school and college athletics, resulting in considerable public concern. We conducted a study of the frequency and causes of nontraumatic sports deaths in high school and college athletes in the USA through the National Center for Catastrophic Sports Injury Research to define the magnitude of this problem and its causes. Over a 10-yr period, July 1983-June 1993, nontraumatic sports deaths were reported in 126 high school athletes (115 males and 11 females) and 34 college athletes (31 males and 3 females). Estimated death rates in male athletes were fivefold higher than in female athletes (7.47 vs 1.33 per million athletes per year, P < 0.0001), and twofold higher in male college athletes than in male high school athletes (14.50 vs 6.60 per million athletes per year, P < 0.0001). Cardiovascular conditions were more common causes of death than noncardiovascular conditions. Hypertrophic cardiomyopathy and congenital coronary artery anomalies were the most common causes of death. In high school and college athletes, males are at increased risk for nontraumatic sports deaths compared with females even after adjustment for participation frequency; college males are at greater risk than high school males. In all groups the deaths were primarily due to cardiovascular conditions.

Acute and chronic effects of exercise using an Exercycle in healthy, untrained adults.

This study examined three factors related to exercise with an Exercycle, a motordriven upper and lower body exercise machine. We examined the effects of Exercycle training on peak oxygen consumption (VO2), peak heart rate, peak minute ventilation, and peak respiratory exchange ratio. We compared the physiologic responses to graded exercise between the Exercycle and a standard lower extremity (LE) cycle ergometer. We also compared the difference in training responses between male and female subjects. A 6-week cardiorespiratory training program was completed by 20 healthy untrained adults (9 male, 11 female), aged 18 to 53 years. Pretraining and posttraining testing was completed on the Exercycle and on an LE cycle ergometer using a graded protocol. Absolute peak VO2 improved by 14% for men and by 7% for women after training based on Exercycle testing and by 6% for both men and women based on LE cycle ergometer testing. The posttraining submaximal heart rates were lower at any given absolute peak VO2 level for the Exercycle but not for the LE cycle ergometer. Exercycle testing revealed a larger peak VO2 than did LE cycle ergometer testing for both genders. The Exercycle appears to be effective for promoting cardiorespiratory fitness in healthy, untrained adults. The authors found comparable submaximal physiologic responses to graded exercise between the Exercycle and the LE cycle ergometer.