REVIEW: Cardiovascular Implantable Electronic Devices in Athletes

Cardiovascular implantable electronic device (CIED) implantation indications have greatly increased over the past decade, with use of pacemakers and implantable cardiac defibrillators now growing more common even in athletes. Management of CIEDs in this subgroup is of greater complexity due to augmented physical stressors, a longer exposure time to system components in a younger population, and less common, highly clinically variable underlying cardiac pathologies. We will review management issues specific to CIED therapy, sudden cardiac death, and consensus recommendations for physical activity.     

Intra-genotypic diversity of archival G4P[8] human rotaviruses from Washington, DC

Group A human rotaviruses (RVs) remain the most frequently detected viral agents associated with acute gastroenteritis in infants and young children. Despite their medical importance, relatively few complete genome sequences have been determined for commonly circulating G/P-type strains (i.e., G1P[8], G2P[4], G3P[8], G4P[8], and G9P[8]). In the current study, we sequenced the genomes of 11 G4P[8] isolates from stool specimens that were collected in Washington, DC during the years of 1974–1991. We found that the VP7–VP4–VP6–VP1–VP2–VP3–NSP1–NSP2–NSP3–NSP4–NSP5/6-encoding genes of all 11 G4P[8] RVs have the genotypes of G4-P[8]-I1-R1-C1-M1-A1-N1-T1-E1-H1. By constructing phylogenetic trees for each gene, extensive intra-genotypic diversity was revealed among the G4P[8] RVs, and new sub-genotype gene alleles were identified. Several of these alleles are nearly identical to those of G3P[8] isolates previously sequenced from this same Washington, DC collection, strongly suggesting that the RVs underwent gene reassortment. On the other hand, we observed that some G4P[8] RVs exhibit completely different allele-based genome constellations, despite being collected during the same epidemic season; there was no evidence of gene reassortment between these strains. This observation extends our previous findings and supports the notion that stable, genetically-distinct clades of human RVs with the same G/P-type can co-circulate in a community. Interestingly, the sub-genotype gene alleles found in some of the DC RVs share a close evolutionary relationship with genes of more contemporary human strains. Thus, archival human RVs sequenced in this study might represent evolutionary precursors to modern-day strains.     

Survey of Insulin Site Rotation in Youth With Type 1 Diabetes Mellitus

ObjectiveInjection site rotation is an important component of insulin administration and is helpful in preventing lipodystrophy in type 1 diabetes (T1DM). We examined the number of injection/infusion sites (sites) used by youth with T1DM and their perceived barriers to using new sites for insulin.MethodsTwo hundred and one youth with T1DM completed a 24-item survey about site rotation practices and barriers to site rotation during a routine diabetes appointment.ResultsFifteen percent of youth reported using at least four distinct sites in their rotation plan, while 22% reported using only one site. A negative correlation was found between number of sites used and the number of perceived barriers endorsed by youth on multiple daily injections. Fear of pain was the most common barrier endorsed by youth.ConclusionMany youth with T1DM may not adhere to an adequate site rotation plan. Regular assessment of insulin sites and counseling regarding adequate site rotation is needed when managing diabetes in youth. Relaxation and distraction may help to reduce youths' fear of pain when rotating to new insulin sites.     

Are adolescents who moderate their cannabis use at lower risk of later regular and dependent cannabis use?

Aims   To examine whether moderation of cannabis use among adolescent cannabis users is associated with reductions in cannabis use frequency and risk of dependence in young adulthood.
Design   Ten-year representative cohort study with six surveys in adolescence (mean age 14.9–17.4 years) and two in young adulthood (mean age 20.7 and 24.1 years).
Participants   Inception cohort of 1943 Victorian secondary school students (96% response rate), with 1520 (78% of adolescent participants) interviewed in the final wave.
Measurements   Participants were classified into six groups according to the maximum level of adolescent use and the extent of subsequent moderation in such use: non-users, occasional to abstinence, occasional persisting, weekly to abstinence, weekly to occasional and weekly persisting. Outcome measures were weekly+ cannabis use and DSM-IV cannabis dependence at 20 and 24 years.
Findings   Thirty-one per cent reported cannabis use during adolescence. Most adolescent users had moderated their use: from occasional to abstinence (71% of occasional users), weekly to abstinence or weekly to occasional (28% and 48% of weekly+ users, respectively). By age 24, both occasional use groups were at similar, elevated risk of regular and dependent cannabis use compared to non-users. Weekly+ adolescent users were at greatest risk of these outcomes, although the weekly to abstinence group exhibited lower risk than those in the weekly persisting and weekly to occasional groups, who were at similar risk.
Conclusions   While many young people have dynamic cannabis use patterns, a pattern of moderating adolescent cannabis use was associated with less risk of later problematic use than among those persisting, but risks were still elevated substantially compared with never-users.     

The Oral HIV/AIDS Research Alliance: updated case definitions of oral disease endpoints

The Oral HIV/AIDS Research Alliance (OHARA) is part of the AIDS Clinical Trials Group (ACTG), the largest HIV clinical trials organization in the world. Its main objective is to investigate oral complications associated with HIV/AIDS as the epidemic is evolving, in particular, the effects of antiretrovirals on oral mucosal lesion development and associated fungal and viral pathogens. The OHARA infrastructure comprises: the Epidemiologic Research Unit (at the University of California San Francisco), the Medical Mycology Unit (at Case Western Reserve University) and the Virology/Specimen Banking Unit (at the University of North Carolina). The team includes dentists, physicians, virologists, mycologists, immunologists, epidemiologists and statisticians. Observational studies and clinical trials are being implemented at ACTG-affiliated sites in the US and resource-poor countries. Many studies have shared end-points, which include oral diseases known to be associated with HIV/AIDS measured by trained and calibrated ACTG study nurses. In preparation for future protocols, we have updated existing diagnostic criteria of the oral manifestations of HIV published in 1992 and 1993. The proposed case definitions are designed to be used in large-scale epidemiologic studies and clinical trials, in both US and resource-poor settings, where diagnoses may be made by non-dental healthcare providers. The objective of this article is to present updated case definitions for HIV-related oral diseases that will be used to measure standardized clinical end-points in OHARA studies, and that can be used by any investigator outside of OHARA/ACTG conducting clinical research that pertains to these end-points.     

Practice-related changes in lumbar loading during rapid voluntary pulls made while standing

Objective. To determine if five days of practice on a novel dynamic, multi-joint pulling task resulted in lower magnitudes of lumbar loading or a more consistent relationship between pulling force and lumbar loading.

Design. A repeated measures design compared how practice influenced the magnitude of lumbar torque and the correlations between lumbar torque and pulling force.

Background. Previous studies suggest that practice can decrease the magnitude of lumbar loading on simple manual material handling tasks, but it is unknown whether practice reduces lumbar loading for more complex tasks. Neither is it known whether the consistency of lumbar loading increases with practice.

Methods. Ten healthy adults practiced impulse-like horizontal pulls to targets equaling 20%, 40% and 80% of their estimated maximal dynamic pulling force over 5 days. Movements were unrestrained, other than keeping the feet flat on the ground. We used a four-segment, sagittal plane inverse dynamics model to compute lumbar, hip, knee, and ankle torques on days 1 and 5 from ground reaction forces and moments, pulling forces, and kinematics.

Results. An analysis of variance showed significant practice-related changes in lumbar torque at the time of peak pulling force (lumbar torque_peakPF). The lumbar torque_peakPF decreased for the 20% pulls, did not change for the 40% pulls, and increased for the 80% pulls. Two subjects showed a significant decrease in lumbar torque_peakPF for all three force levels. Coefficients of determination between pulling force and lumbar torque (r²_PF,LT: a measure of the consistency of the relationship between these two variables) were significantly higher on day 5 than day 1.

Conclusions. Practice on a novel pulling task changed the magnitude of lumbar torques and increased their correlation with pulling force, suggesting that subjects learned strategies that improve motor control of lumbar torques.Relevance

The study showed that the magnitude and consistency of lumbar loading changed spontaneously as subjects practiced a novel multijoint pulling task. Such changes may decrease the risk of low-back injury.     

Hemorrhagic lymphadenopathy as a presenting feature of primary al amyloidosis

Lymphadenopathy associated with hemorrhage as a presenting feature of primary (AL) amyloidosis has not previously been described. We report two such cases one of whom had an acquired factor X and IX deficiency. The clinical presentations were characterized by sudden spontaneous enlargement of lymph nodes followed by partial regression. In both cases significant delay in diagnosis, and hence treatment, occurred due to the mode of presentation. One patient died with rapidly progressive disease but the other has had an excellent response to therapy with high-dose melphalan (HDM, 200 mg/m2) and peripheral blood stem cell rescue. AL amyloid should be considered in all patients presenting with hemorrhagic lymphadenopathy.     

Comparing population estimates for drug users, the prevalence of blood-borne viruses and the provision of services in one London borough: Evidence of a gap in provision?

Aims: To estimate the size of the drug-using population in Lambeth, an inner city London borough, and the prevalence of blood-borne virus (BBV) infections in the drug-using population. To identify possible shortfalls in service provision for drug users.

Methods: Direct and indirect estimates of the drug-using population size using national and local data sources. Prevalence estimates for BBV infections were derived from local survey data. Routine data and a survey of borough services for drug users were compiled.

Findings: Based on indirect methods we estimated there were 3117 drug users in Lambeth in 2001-2002 (20 per 1000, 15- to 44-year-olds), of whom 1641 were injecting users (11 per 1000); 1353 were reported as being in drug treatment programmes. BBV prevalence rates: hepatitis B, 37%; hepatitis C, 71%; HIV, 6%. Estimated demand for needle exchange services, in terms of one syringe per injection, and methadone maintenance may be up to double local provision.

Conclusions: More accurate and feasible methods are needed for the routine estimation of the population of drug users. Accurate information is needed for service planning.     

Successful hysteroscopic cannulation and tubal transfer of cryopreserved embryos

Clinical trials comparing nonsurgical transfer techniques with laparoscopic directed methods are needed to determine the most successful and cost-effective approach for gamete and ET. We report the successful nonsurgical transfer of frozen-thawed embryos into the fallopian tube after our initial attempt resulting in an ongoing IUP. The process is relatively simple, safe, and avoids the risks of general anesthesia. Unlike US-guided tubal cannulation, this technique offers direct, clear visualization of the tubal ostium, assuring the desired catheter placement. As well, hysteroscopic guidance allows an accurate estimate of the depth of catheter insertion within the fallopian tube, which may be a critical factor in successful tubal deposition of gametes or embryos. Whether prolonged carbon dioxide exposure of the tubal microenvironment and/or direct endometrial trauma limits the efficacy of this technique remains to be determined. Finally, outpatient hysteroscopic directed tubal cannulation holds promise as a methodological technique that ultimately assists in the examination of the best site for embryo deposition (tubal versus uterine) and/or method of delivery (nonsurgical versus surgical).