Prevention of knee injuries in sports. A systematic review of the literature.

AIM: We reviewed evidence regarding risk factors associated with incidence of knee injuries both to assess the effectiveness of prevention strategies, and to offer evidence-based recommendations to physicians, coaches, trainers, athletes, and researchers. METHODS: We searched electronic data bases without language restriction for the years 1966 - September 1, 2001, identified citations from reference sections of research papers retrieved, contacted experts in the field, and searched the Cochrane Collaboration. Of the 328 citations identified, we emphasized the results from the 13 reports that compared alternative methods to prevent knee injury and assessed the methodologic quality of these reports using a standardized instrument. RESULTS: Five studies addressed the effectiveness of bracing in football players; these studies showed no consistent evidence of benefit. Two studies comparing alternative cleat designs and a controlled study testing the effects of adjustments in the ski boot/binding system were difficult to interpret because of inadequate reporting of methodology. Six prospective studies that addressed the impact of conditioning and training showed promise of proprioception and neuromuscular training for protection against knee injury. We identified serious flaws in study design, control of bias, and statistical methods; the median quality scores ranged from 11 to 56 (out of 100). CONCLUSION: Structured training programs that emphasize neuromuscular and proprioceptive training offer encouraging evidence for the prevention of knee injuries. However, flaws in study design and implementation have limited the effectiveness of work in this field. A rigorously implemented research program is needed to address this critically important sports medicine problem.

Lactulose-induced pneumatosis intestinalis and pneumoperitoneum.

A case of PI in a 57-year-old patient with colonic inertia treated with lactulose for PSE secondary to cirrhosis is described. The colonic inertia led to longer transit time. Retained lactulose and a build-up of carbon dioxide and hydrogen gas occurred in the setting of altered bacterial flora deficient in hydrogen metabolism. The increased gas pressure caused extravasation of air into the intestine, causing PI with pneumoperitoneum. They both resolved with discontinuation of lactulose.

Improving adolescent preventive care in community health centers.

OBJECTIVE: To evaluate implementation of the Guidelines for Adolescent Preventive Services (GAPS) in Community and Migrant Health Centers (CMHCs). DESIGN: Before and after comparison of health center policy, clinician and adolescent self-report, and chart reviews in 5 CMHCs. PARTICIPANTS: Eighty-one preintervention and 80 one-year postintervention providers and 318 preintervention and 331 postintervention 14- to 19- year-old adolescent patients being seen for well visits at 5 CMHCs. INTERVENTION: Health center staff were trained to implement GAPS and were provided resource materials, patient questionnaires, and clinician manuals. MAIN OUTCOME MEASURES: Delivery of and receipt of preventive services and perceived access to care. RESULTS: CMHC systems changes were related to stronger leadership commitment to adolescent care. Providers reported high levels of preventive services delivery before and after guideline implementation. After guideline implementation, adolescents reported increases in having discussed prevention content with providers in 19 of 31 content areas, including increased discussion of physical or sexual abuse (10% before to 22% after), sexual orientation (13% to 27%), fighting (6% to 21%), peer relations (37% to 52%), suicide (7% to 22%), eating disorders (11% to 28%), weapons (5% to 22%), depression (16% to 34%), smokeless tobacco (10% to 29%), and immunizations (19% to 48%). Adolescents were also more likely to report knowing where to get reproductive or mental health services and were more likely to have received health education materials. Implementation also increased documentation of recommended screening and counseling in 51 of 79 specific content areas assessed in chart reviews. CONCLUSION: Implementing GAPS increased the receipt of preventive services at these health centers. Adolescents received more comprehensive screening and counseling, more health education materials, and had greater access to care after implementation. GAPS implementation may help improve the quality of care for adolescents.

The prevention of ankle sprains in sports. A systematic review of the literature.

To assess the published evidence on the effectiveness of various approaches to the prevention of ankle sprains in athletes, we used textbooks, journals, and experts in the field of sports medicine to identify citations. We identified 113 studies reporting the risk of ankle sprains in sports, methods to provide support, the effect of these interventions on performance, and comparison of prevention efforts. The most common risk factor for ankle sprain in sports is history of a previous sprain. Ten citations of studies involving athletes in basketball, football, soccer, or volleyball compared alternative methods of prevention. Methods tested included wrapping the ankle with tape or cloth, orthoses, high-top shoes, or some combination of these methods. Most studies indicate that appropriately applied braces, tape, or orthoses do not adversely affect performance. Based on our review, we recommend that athletes with a sprained ankle complete supervised rehabilitation before returning to practice or competition, and those athletes suffering a moderate or severe sprain should wear an appropriate orthosis for at least 6 months. Both coaches and players must assume responsibility for prevention of injuries in sports. Methodologic limitations of published studies suggested several areas for future research.

Prevention of infectious disease transmission in sports.

A variety of infectious diseases can be transmitted during competitive sports. Modes of transmission in athletic settings include person-to-person contact, common-source exposures and airborne/droplet spread. This paper reviews the most commonly reported infectious diseases among athletes and discusses the potential for transmission of bloodborne diseases in sports. Guidelines are provided regarding measures to prevent transmission of infectious diseases in athletic settings, including hygiene and infection control practices, vaccination, and education of officials, coaches, trainers and sports participants.

Regulated stimulation of epithelial cell DNA synthesis by fibroblast-derived mediators.

Interactions of interstitial fibroblasts with nearby epithelial cells are thought to play a role in lung growth and development. The present studies support this premise. Medium conditioned by second-passage lung fibroblasts (FCM) stimulated both DNA synthesis and accumulation in low-density (2 x 10(4)/cm2) cultures of type II alveolar epithelial cells. FCM effects did not require serum; they were time- and dose dependent, with half-maximal FCM activity at 1:8 dilution. A maximal response to FCM required 30 h of exposure. FCM activity was reduced in medium from fibroblasts treated with dexamethasone, suggesting physiological regulation. Type II cells subjected to cyclic mechanical stress demonstrated an increased response to FCM compared with static cultures. FCM activity did not appear to be accounted for by hepatocyte growth factor, keratinocyte growth factor, acidic fibroblast growth factor, or fibronectin. These results suggest that early passage lung fibroblasts release, by regulated pathways, one or more factors that stimulate DNA synthesis by type II cells. Sensitivity to FCM appears to be elevated in type II cell cultures subjected to cyclic mechanical stress.

Retrospective diagnosis of hantavirus pulmonary syndrome, 1978-1993: implications for emerging infectious diseases.

OBJECTIVE: To investigate the occurrence of unrecognized cases of hantavirus pulmonary syndrome preceding the detection of the 1993 outbreak in the southwestern United States and the initial description of the syndrome. DESIGN: Retrospective clinicopathologic and immunohistologic study. PATIENTS: Eighty-two patients who died prior to April 1993 with histologically unexplained noncardiogenic pulmonary edema. METHODS: Clinicopathologic review and immunohistochemical evaluation of autopsy tissues for evidence of hantaviral infection. RESULTS: Twelve retrospective fatal cases of hantavirus pulmonary syndrome were identified through clinicopathologic review and immunohistochemical testing of tissues. Patients' ages ranged from 16 to 49 years. The earliest identified case occurred in 1978, 15 years prior to the outbreak of hantavirus pulmonary syndrome in the southwestern United States. Immunohistochemical testing showed widespread deposition of hantaviral antigens, primarily within endothelial cells, similar to the pattern observed with current hantavirus pulmonary syndrome cases. CONCLUSIONS: Although hantavirus pulmonary syndrome was first recognized in 1993, the findings from this study document the earlier existence of this disease. These findings underscore the need for systematic archiving and analysis of clinical information and specimens from patients with diseases of unknown etiology to facilitate the study of new clinical entities and their associated etiologic agents.

Composition of extracellular matrix of type II pulmonary epithelial cells in primary culture.

Type II pulmonary epithelial cells in primary culture synthesize and deposit an extracellular matrix which has reciprocal biological effects on cellular differentiation. The present work establishes conditions for metabolic labeling of matrix constituents and for separation of cells from the associated matrix; it also defines matrix composition, which does not appear to change qualitatively between days 2 and 6 of primary culture. Type II cells synthesize and deposit a spectrum of radiolabeled components on the culture surface. These include fibronectin, laminin, type IV collagen, and plasminogen activator inhibitor-1, along with additional unidentified proteins. Few radiolabeled proteins in medium conditioned by type II cells bind nonspecifically to the culture surface in the absence of cells. Fibroblasts and macrophages, which may contaminate the primary cultures, do not appear to contribute substantially to the type II cell matrix. These results demonstrate that type II cells synthesize and deposit a complex multicomponent extracellular matrix. The work provides a basis for further investigations of bidirectional interactions between type II cells and the extracellular matrix.

Turnover of fibronectin and laminin by alveolar epithelial cells.

Type II pulmonary epithelial cells in primary culture synthesize and assemble a multicomponent extracellular matrix which exhibits biological activity in vitro. Simultaneously, the pneumocytes degrade components of the underlying matrix, such that matrix composition may be determined by the balance of synthesis and turnover. The present work defines turnover of the specific matrix glycoproteins, fibronectin and laminin, both in the type II cell and in its extracellular matrix. Pulse-chase experiments demonstrate that both fibronectin and laminin, identified by immunoprecipitation, turn over rapidly in the cell and extracellular matrix compartments, with half-lives < 10 h. In the cell compartment, initial rates of laminin turnover are more rapid than those of fibronectin on culture day 2, but these rates are similar on day 6. Matrix fibronectin also turns over rapidly, with similar rates on day 2 and day 6. During the chase interval, small but increasing amounts of immunoprecipitable fibronectin are detected in the medium, suggesting that a portion of the glycoprotein may be released to the extracellular compartment, rather than degraded. Alternatively, release of immunoreactive glycoprotein may involve ongoing processing and secretion of residual radiolabeled fibronectin by the cells. The results suggest that matrix composition may be determined by turnover, as well as synthesis, of its components.

Transmission of blood-borne pathogens during sports: risk and prevention.

Publicity about human immunodeficiency virus (HIV) infection in athletes has focused attention on the potential for transmission of blood-borne pathogens during sports and athletic competitions. Existing information suggests that the potential risk for such transmission is extremely low and that the principal risks athletes have for acquiring HIV and hepatitis B virus are related to off-the-field activities. Therefore, efforts to prevent transmission of blood-borne pathogens among athletes should emphasize prevention in off-the-field settings. We summarize technical and other information about this issue, and provide recommendations for the education of sports participants, for infection control in athletic settings, and for training of coaches and officials.

Workplace-related homicide among health care workers in the United States, 1980 through 1990.

OBJECTIVE: To improve understanding of the epidemiology of fatal violence directed toward physicians and other health care workers (HCWs) in health care settings. DESIGN: Analyses of data for 1980 through 1990 from the National Traumatic Occupational Fatalities surveillance system. MAIN OUTCOME MEASURES: Overall occurrence of occupational injury deaths and occurrence of workplace-related homicides among HCWs. RESULTS: From 1980 through 1990, a total of 522 HCWs died from injuries sustained while working. The most common causes of death were motor vehicle crashes (122 [23.4%]), homicide (106 [20.3%]), and suicide (88 [16.9%]). Firearms were used in the greatest number (78 [73.6%]) of workplace-related homicides among HCWs. CONCLUSIONS: These findings highlight the need for strengthened surveillance and more accurate estimates of the risks of workplace-related violent injury for HCWs in the United States.

Infectious diseases in competitive sports.

OBJECTIVE: Participation in competitive sports is popular and widely encouraged throughout the United States. Reports of infectious disease outbreaks among competitive athletes and recent publicity regarding infectious disease concerns in sports underscore the need to better characterize the occurrence of these problems. DATA SOURCES: To identify reports of infectious diseases in sports, we performed a comprehensive search of the medical literature (MEDLINE) and newspaper databases in two on-line services (NEXIS and DIALOG PAPERS). STUDY SELECTION: Articles selected from the literature review included those describing cases or outbreaks of disease in which exposure to an infectious agent was likely to have occurred during training for competitive sports or during actual competition. Articles from the newspaper review included reports of outbreaks, exposures, or preventive measures that directly or indirectly involved teams or spectators. DATA SYNTHESIS: The literature review identified 38 reports of infectious disease outbreaks or other instances of transmission through person-to-person (24 reports), common-source (nine reports), or airborne (five reports) routes; the newspaper search identified 28 reports. Infectious agents included predominantly viruses but also a variety of fungi and gram-positive and gram-negative bacteria. CONCLUSIONS: Our findings indicate that strategies to prevent transmission of infectious diseases in sports must recognize risks at three levels: the individual athlete, the team, and spectators or others who may become exposed to infectious diseases as a result of sports-related activities. Team physicians and others who are responsible for the health of athletes should be especially familiar with the features of infectious diseases that occur in sports and measures for the prevention of these problems.

Health care and public health in the former Soviet Union, 1992. Ukraine--a case study.

The dissolution of the Soviet Union created many problems for the health care systems of the New Independent States (NIS). To address these problems, the U.S. Secretary of State convened a coordinating conference in Washington, D.C., on 22-23 January 1992 at which more than 50 nations and organizations were represented. After this conference, an expert medical working group visited 10 republics of the NIS during February and March 1992. Hospitals, public health facilities, and pharmaceutical plants and distribution sites were visited to assess the health care needs of a large population in a vast geographic area. It was concluded that the massive health care system of the Soviet Union remains largely intact but has major economic and supply deficiencies. The assessment process and findings in one republic, Ukraine, are presented. Ukraine was chosen because of its size, location, and representativeness.