DNA sperm damage correlates with nuclear ultrastructural sperm defects in teratozoospermic men

Sperm morphology has consistently been the best indicator of male fertility. Transmission electron microscopy currently provides the most information on the subcellular details of sperm structure. Recently, assessment of sperm DNA damage has been employed to assess fertility potential. The purpose of this work was to link sperm DNA damage, evaluated by an intercalated fluorescent dye, with the structural characteristics of sperm. Conventional semen analysis was performed on samples from men undergoing fertility evaluation. Thirty men were evaluated and assigned to three subgroups based on strict criteria for sperm morphology: normal morphology (>14% normal forms), intermediate morphology (5-14% normal forms), and poor morphology (<5% normal forms). By quantifying acridine orange-positive cells and ultrastructural sperm defects, we found that the poor morphology pattern group showed a positive association between sperm carrying damaged DNA and the percentage of sperm nucleus with vacuoles (P = 0.01). No statistically significant correlations were established in other ultrastructural characteristics of sperm, including immature chromatin, lytic changes, or abnormal sperm tails. These results suggest that zones without chromatin in the sperm nucleus reflect underlying chromosomal or DNA defects in severe teratozoospermic men. This association should be considered in the evaluation of male fertility.     

Higher premenarcheal bone mass in elite gymnasts is maintained into young adulthood after long‐term retirement from sport: A 14‐year follow‐up

Sports that impact‐load the skeleton during childhood and adolescence increase determinants of bone strength such as bone mineral content and density; however, it is unclear if this benefit is maintained after retirement from the sport. The purpose of this study was to assess whether the previously reported higher bone mass in a group of premenarcheal gymnasts was still apparent 10 years after the cessation of participation and withdrawal of the gymnastics loading stimulus. In 1995, 30 gymnasts 8 to 15 years of age were measured and compared with 30 age‐matched nongymnasts. Twenty‐five former gymnasts and 22 nongymnasts were measured again 14 years later (2009 to 2010). Gymnasts had been retired from gymnastics training and competition for an average of 10 years. Total body (TB), lumbar spine (LS), and femoral neck (FN) bone mineral content (BMC) was assessed at both measurement occasions by dual‐energy X‐ray absorptiometry (DXA). Multivariate analysis of covariance (MANCOVA) was used to compare former gymnasts' and nongymnasts' BMC while controlling for differences in body size and maturation (covariates: age, height, weight, and years from menarche [1995] or age at menarche [2009 to 2010]). Premenarcheal gymnasts (measured in 1995) had significantly greater size‐adjusted TB, LS, and FN BMC (p < 0.05) (15%, 17%, and 12%, respectively) than nongymnasts. Ten years after retirement, gymnasts had maintained similar size‐adjusted TB, LS, and FN BMC differences (p < 0.05) (13%, 19%, and 13%, respectively) when compared with nongymnasts. Bone mass benefits in premenarcheal gymnasts were still apparent even after long‐term (10 years) removal of the gymnastics loading stimulus. © 2012 American Society for Bone and Mineral Research     

Former premenarcheal gymnasts exhibit site‐specific skeletal benefits in adulthood after long‐term retirement

Young female gymnasts have greater bone strength compared to controls; although possibly due to selection into gymnastics, it is thought that their loading activity during growth increases their bone mass, influencing both bone geometry and architecture. If such bone mass and geometric adaptations are maintained, this may potentially decrease the risk of osteoporosis and risk of fracture later in life. However, there is limited evidence of the persisting benefit of gymnastic exercise during growth on adult bone geometric parameters. Therefore, the purpose of this study was to determine whether adult bone geometry, volumetric density, and estimated strength were greater in retired gymnasts compared to controls, 10 years after retirement from the sport. Bone geometric and densitometric parameters, measured by peripheral quantitative computed tomography (pQCT) at the radius and tibia, were compared between 25 retired female gymnasts and 22 controls, age range 22 to 30 years, by multivariate analysis of covariance (covariates: age, height, and muscle cross‐sectional area). Retired gymnasts had significantly greater adjusted total and trabecular area (16%), total and trabecular bone mineral content (BMC) (18% and 22%, respectively), and estimated strength (21%) at the distal radius (p < 0.05) than controls. Adjusted total and cortical area and BMC, medullary area, and estimated strength were also significantly greater (13% to 46%) in retired gymnasts at the 30% and 65% radial shaft sites (p < 0.05). At the distal tibia, retired gymnasts had 12% to 13% greater total and trabecular BMC and volumetric bone mineral density as well as 21% greater estimated strength; total and cortical BMC and estimated strength were also greater at the tibial shaft (8%, 11%, and 10%, respectively) (p < 0.05). Former female gymnasts have significantly better geometric and densitometric properties, as well as estimated strength, at the radius and tibia 10 years after retirement from gymnastics compared to females who did not participate in gymnastics in childhood and adolescence. © 2012 American Society for Bone and Mineral Research.     

Multiple Poisonings with Sodium Azide at a Local Restaurant

Background

Sodium azide is a chemical with a mechanism similar to cyanide. There is concern that it could be used as a chemical warfare agent.

Objectives

We report a cluster of poisonings that occurred at a public restaurant and the subsequent investigation that identified iced tea contaminated with sodium azide (NaN₃) and hydrazoic acid, as the foodborne vehicle and agents, respectively.

Case Report

Five patients became ill within minutes of drinking iced tea at a restaurant. They all presented to the same Emergency Department with similar symptoms, and improved with fluids, antiemetics, and supportive care. A joint investigation by the Dallas County Department of Health and Human Services, the Texas State Health Department, the Dallas County Southwestern Institute of Forensic Sciences, and the medical toxicologists at the University of Texas Southwestern School of Medicine identified iced tea, contaminated with sodium azide (NaN₃) and hydrazoic acid, as the foodborne vehicle and agents, respectively.

Conclusion

The recurrence, and seriousness, of these events suggests a need for continued education of emergency providers. Emergency physicians should consider exposures to toxic chemicals in their differential when a cluster of patients presents with similar symptoms over a short period of time.     

Effectiveness of the SLICE Program for Youth Concussion Education

OBJECTIVE:: To analyze the effectiveness of the Sports Legacy Institute Community Educators (SLICE) curriculum for student-athletes on recognition and appropriate responses to concussions. DESIGN:: Prospective cohort study, level II. SETTING:: The SLICE concussion workshop. PARTICIPANTS:: All students ranging from 9 to 18 years (n = 636) taking the SLICE concussion education program. INTERVENTION:: The SLICE concussion education program featuring interactive demonstrations, discussion, and case studies of athletes delivered by medical students and others in health-related fields. MAIN OUTCOME MEASURES:: Evaluations assessing knowledge of concussion recognition and appropriate response were administered before and after participating in the SLICE concussion education program. RESULTS:: Students displayed significant improvements in absolute mean score on the concussion knowledge quiz between prepresentation and postpresentation (P < 0.0001). Significant improvements in mean score were observed among both male and female students within each age group. The proportion of students who passed the quiz increased from 34% prepresentation to 80% postpresentation (P < 0.0001). However, the percentage who passed the quiz postpresentation was significantly higher among female students compared with male students (P < 0.0001) and among students 13 years of age or older compared with students less than 13 years (P < 0.0001). Using multivariable logistic regression, we identified age group and gender as the most significant factors associated with passing the quiz postpresentation. CONCLUSION:: The SLICE program promotes effective learning and knowledge about concussion recognition and response among students ranging from 9 to 18 years. Lessons from the SLICE program may be broadly applicable to youth concussion education.     

Neurotoxicity, anticoagulant activity and evidence of rhabdomyolysis in patients bitten by death adders (Acanthophis sp.) in southern Papua New Guinea

Thirty-two patients with enzyme-immunoassay-proven death adder (Acanthophis sp.) bites were studied in Port Moresby, Papua New Guinea. Eighteen were envenomed; local signs were rare and none had incoagulable blood, but all except one had signs of neurotoxicity. Five (27.7%) envenomed patients required intubation and ventilation. One patient developed renal failure, previously undescribed following death adder bites. Laboratory investigations showed mild prolongation of prothrombin and partial thromboplastin times in some patients. In vitro studies showed that the venom contains anticoagulant activity, but does not cause fibrinogenolysis. In contrast to taipan envenoming, neurotoxicity did not progress after antivenom administration, and there was reversal of neurotoxicity, evident within 6 h, in three severely envenomed patients treated less than 12 h after the bite. One patient treated with antivenom and anticholinesterases had the most dramatic response to treatment; the optimum management of bites by this species may include prompt treatment with both antivenom and anticholinesterases in addition to effective first aid.      

Informed consent for blood transfusion: a regional hospital survey

Ninety-two hospitals in a three-state mid-Atlantic region were surveyed to determine their policy toward obtaining written informed consent for transfusion and to examine the content of written consent documents and the process by which consent is obtained. Of 81 hospitals responding, 50 (62%) required written informed consent. Hospitals with fewer than 200 beds were more likely to require written informed consent. The attending physicians had responsibility for obtaining consent in 28 (57%) of 49 institutions, most often on the day or evening before surgery. Twenty-seven of 48 forms mentioned complications: hepatitis in 80 percent, human immunodeficiency virus infection in 46 percent, nonhemolytic reactions in 32 percent, and hemolysis in 25 percent. Alternatives to allogeneic transfusion were mentioned infrequently; eight hospital forms listed autologous transfusion options and only two mentioned designated donation. The reading level required to comprehend 34 consent forms submitted was grade 14.6, which has been attained by only 23 percent of the adult United States population. Although the majority of respondent institutions require written informed consent, those forms, per se, do not document that the fundamental tenets of informed choice have been applied to the decision to transfuse blood.     

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.