Evolving applications in the use of bone-anchored hearing aids

The bone-anchored hearing aid (BAHA) is an effective means of intervention, its use being well documented in persons with chronic conductive pathology and congenital aural anomalies. This article describes the standard guidelines (both auditory and extraauditory aspects) for patient selection and expands the criteria to include bilateral BAHA implantation, unilateral conductive hearing loss, and unilateral profound sensorineural hearing loss. The BAHA's development, design features, and patient outcomes are also reviewed. Suggestions are presented for fitting, counseling, and following BAHA users.     

Patterns and timing of artificial urinary sphincter failure

Purpose

To assess population-based trends in artificial urinary sphincter (AUS) placement after prostatectomy and determine the effect of timing on device survival and complications.

Methods

We identified patients who underwent prostatectomy and AUS placement in SEER-Medicare from 2002 to 2011. We analyzed factors affecting the time of reoperation from AUS implantation and prostatectomy using multivariable Cox proportional hazard models.

Results

In total, 841 men underwent AUS placement at a median 23 months after prostatectomy. Patients who underwent reoperation (28.5%) had higher clinical stage, more likely underwent open prostatectomy, or had prior sling placement (p < 0.03). There were no differences in rates of diabetes, smoking status, prior radiation therapy, or Charlson Comorbidity Index between those requiring reoperation vs. not (all p > 0.15). Patients with AUS placement > 15 months after prostatectomy (75%) initially experienced less need for operative reinterventions. Patients with later AUS placement were significantly more likely to have received radiation therapy [22.9 vs. 3.8% (p < 0.01)]. Nonetheless, late implantation was confirmed to be protective on multivariate analysis during the first 5 years after AUS placement [HR 0.79 (95% CI 0.67–0.92); p < 0.01]. Factors independently associated with a shorter interval time until reoperation included history of radiation [HR 1.93 (95% CI 1.33–2.80); p < 0.01] and history of prior sling [HR 1.70 (95% CI 1.08–2.68); p = 0.02]. Even for patients who underwent radiation therapy, delayed AUS implantation reduced reoperative risk.

Conclusions

Late AUS implantation in the Medicare population is associated with prolonged device survival initially, while radiation and prior sling surgery predict for earlier reoperation. Patients with delayed AUS implantation experience less immediate complications. Further work is required to identify patient-specific factors which may explain variability in timing for AUS.

     

Inhaled nitric oxide reverses cell-free hemoglobin-induced pulmonary hypertension and decreased lung compliance. Preliminary results

Background

In order to test the hypothesis that inhaled nitric oxide (NO) reverses the pulmonary hypertension induced by αα-diaspirin crosslinked hemoglobin (ααHb), were studied anesthetized pigs that were administered with a total dose of 200 mg/kg of 10% ααHb. Inhaled NO (5 ppm) was administered for 10 min, and then discontinued for 10 min. This cycle was then repeated with 10 ppm inhaled NO.

Results

ααHb caused pulmonary arterial pressure (PAP) to increase from 27 ± 1.7 to 40 ± 3.0 mmHg (P<0.05) and dynamic lung compliance to decrease from 29± 1.5 to 23± 1.6 ml/cmH₂O (P < 0.05). After both doses of inhaled NO, but particularly 10 ppm, PAP was reduced (P < 0.05) and lung compliance increased (P < 0.05) from the ααHb levels. When inhaled NO was discontinued PAP again increased and lung compliance decreased to levels significantly different from baseline (P < 0.05).

Conclusion

We conclude that cell-free hemoglobin-induced pulmonary hypertension and decreased lung compliance can be selectively counteracted by inhaled NO.     

Systemic delivery of human microdystrophin to regenerating mouse dystrophic muscle by muscle progenitor cells

Cell-based therapy for Duchenne muscular dystrophy patients and mdx mice has proven to be a safe but ineffective form of treatment. Recently, a group of cells called muscle side population (SP) cells have been isolated based on their ability to efflux the DNA-binding dye Hoechst. To understand the potential of skeletal muscle SP cells to serve as precursors for muscle, SP cells from the two mice strains mdx(5cv) and C57BL/6N were isolated, transduced, and transplanted. Under coculture conditions with myogenic cells, some cells within the SP cell population can give rise to early Pax7-positive satellite cells and other later stage myogenic cells. Transduced SP cells were transplanted via the tail vein and were shown to successfully deliver enhanced GFP and human microdystrophin to the skeletal muscle of nonirradiated mdx(5cv) mice, thus demonstrating their ability to travel through the capillaries and enter into damaged muscle. These results demonstrate that i.v. delivery of genes via SP cells is possible and that these SP cells are capable of recapitulating the myogenic lineage. Because this approach shows definitive engraftment by using autologous transplantation of noninjured recipients, our data may have substantial implications for therapy of muscular dystrophy.     

Limitations of the criteria used to diagnose histologic endometritis in epidemiologic pelvic inflammatory disease research

While endometrial neutrophils and plasma cells are criteria used to diagnose histologic endometritis in epidemiologic pelvic inflammatory disease (PID) research, plasma cell misidentification and nonspecificity may limit the accuracy of these criteria. Herein, we examined: (1) the identification of endometrial plasma cells with conventional methyl green pyronin-based methodology versus plasma cell-specific (CD138) immunostaining, (2) the prevalence of endometrial plasma cells among women at low risk for PID, and (3) endometrial leukocyte subpopulations among women diagnosed with acute or chronic histologic endometritis by conventional criteria. We observed an absence of CD138⁺ cells in 25% of endometrial biopsies in which plasma cells had been identified by conventional methodology, while additional immunohistochemical analyses revealed indistinguishable inflammatory infiltrates among women diagnosed with acute or chronic endometritis by conventional criteria. Among women considered at lower risk for PID development, flow cytometric analyses detected plasma cells in 30% of endometrial biopsy specimens, suggesting that these cells, even when accurately identified, only nonspecifically identify upper genital tract inflammatory processes. Combined, our findings underscore the limitations of the criteria used to diagnose histologic endometritis in PID-related research and suggest that satisfactory understanding of PID pathogenesis, treatment, and prevention is hindered by continued use of these criteria.     

Interpreting Clinical Reaction Time Change and Recovery After Concussion: A Baseline Versus Norm-Based Cutoff Score Comparison

ContextPreseason testing can be time intensive and cost prohibitive. Therefore, using normative data for postconcussion interpretation in lieu of preseason testing is desirable.ObjectiveTo establish the recovery trajectory for clinical reaction time (RT_clin) and assess the usefulness of changes from baseline (comparison of postconcussion scores with individual baseline scores) and norm-based cutoff scores (comparison of postconcussion scores with a normative mean) for identifying impairments postconcussion.DesignCase-control study.SettingMultisite clinical setting.Patients or Other ParticipantsAn overlapping sample of 99 participants (age = 19.0 ± 1.1 years) evaluated within 6 hours postconcussion, 176 participants (age = 18.9 ± 1.1 years) evaluated at 24 to 48 hours postconcussion, and 214 participants (age = 18.9 ± 1.1 years) evaluated once they were cleared to begin a return-to-play progression were included. Participants with concussion were compared with 942 control participants (age = 19.0 ± 1.0 years) who did not sustain a concussion during the study period but completed preseason baseline testing at 2 points separated by 1 year (years 1 and 2).Main Outcome Measure(s)At each time point, follow-up RT_clin (ie, postconcussion or year 2) was compared with the individual year 1 preseason baseline RT_clin and normative baseline data (ie, sex and sport specific). Receiver operating characteristic curves were calculated to compare the sensitivity and specificity of RT_clin change from baseline and norm-based cutoff scores.ResultsClinical reaction time performance declined within 6 hours (18 milliseconds, 9.2% slower than baseline). The decline persisted at 24 to 48 hours (15 milliseconds, 7.6% slower than baseline), but performance recovered by the time of return-to-play initiation. Within 6 hours, a change from baseline of 16 milliseconds maximized combined sensitivity (52%) and specificity (79%, area under the curve [AUC] = 0.702), whereas a norm-based cutoff score of 19 milliseconds maximized combined sensitivity (46%) and specificity (86%, AUC = 0.700). At 24 to 48 hours, a change from baseline of 2 milliseconds maximized combined sensitivity (64%) and specificity (61%, AUC = 0.666), whereas a norm-based cutoff score of 0 milliseconds maximized combined sensitivity (63%) and specificity (62%, AUC = 0.647).ConclusionsNorm-based cutoff scores can be used for interpreting RT_clin scores postconcussion in collegiate athletes when individual baseline data are not available, although low sensitivity and specificity limit the use of RT_clin as a stand-alone test.