Auditory toxicity in late preterm and term neonates with severe jaundice.

AIM: Jaundice may cause auditory toxicity (auditory neuropathy and hearing loss). However, total serum bilirubin (TSB) does not discriminate neonates at risk for auditory toxicity. We compared TSB, bilirubin:albumin molar ratio (BAMR), and unbound bilirubin for their association with auditory toxicity in neonates with severe jaundice (TSB ≥342µmol/L, or that met exchange transfusion). METHOD: Neonates greater or equal to 34 weeks gestational age with severe jaundice during the first 2 postnatal weeks were eligible for prospective cohort study, unless they had craniofacial malformations, chromosomal disorders, toxoplasmosis, other infections, rubella, cytomegalovirus, herpes simplex infections, surgery, or family history of congenital deafness. RESULTS: Twenty-eight out of 100 neonates (mean gestational age 37.4wks; 59 males, 41 females) had auditory toxicity. Peak unbound bilirubin, but not peak TSB and BAMR, was associated with auditory toxicity (p<0.05) in neonates with severe (TSB <427.5µmol/L) and extreme hyperbilirubinemia (TSB ≥427.5µmol/L). Area under the receiver operating characteristic curve for unbound bilirubin (0.78) was significantly greater (p=0.03) than TSB (0.54) among neonates with severe but not extreme hyperbilirubinemia. INTERPRETATION: Unbound bilirubin is more strongly associated with auditory toxicity than TSB and/or BAMR in greater or equal to 34 weeks gestational age neonates with severe jaundice. Unbound bilirubin is a better predictor than TSB in neonates with severe hyperbilirubinemia.

Unbound Bilirubin and Auditory Neuropathy Spectrum Disorder in Late Preterm and Term Infants with Severe Jaundice.

OBJECTIVE: This study evaluates whether unbound bilirubin is a better predictor of auditory neuropathy spectrum disorder (ANSD) than total serum bilirubin (TSB) or the bilirubin:albumin molar ratio (BAMR) in late preterm and term neonates with severe jaundice (TSB ≥20 mg/dL or TSB that met exchange transfusion criteria). STUDY DESIGN: Infants ≥34 weeks' gestation with severe jaundice during the first 2 weeks of life were eligible for the prospective observational study. A comprehensive auditory evaluation was performed within 72 hours of peak TSB. ANSD was defined as absent or abnormal auditory brainstem evoked response waveform morphology at 80-decibel click intensity in the presence of normal outer hair cell function. TSB, serum albumin, and unbound bilirubin were measured using the colorimetric, bromocresol green, and modified peroxidase method, respectively. RESULTS: Five of 44 infants developed ANSD. By logistic regression, peak unbound bilirubin but not peak TSB or peak BAMR was associated with ANSD (OR, 4.6; 95% CI, 1.6-13.5; P = .002). On comparing receiver operating characteristic curves, the area under the curve for unbound bilirubin (0.92) was significantly greater (P = .04) compared with the area under the curve for TSB (0.50) or BAMR (0.62). CONCLUSIONS: Unbound bilirubin is a more sensitive and specific predictor of ANSD than TSB or BAMR in late preterm and term infants with severe jaundice.

Prevalence of anemia and associations between neonatal iron status, hepcidin, and maternal iron status among neonates born to pregnant adolescents.

BACKGROUND: Little is known about anemia and iron status in US newborns because screening for anemia is typically not undertaken until 1 y of age. This study was undertaken to characterize and identify determinants of iron status in newborns born to pregnant adolescents. METHODS: Pregnant adolescents (≤ 18 y, n = 193) were followed from ≥ 12 wk gestation until delivery. Hemoglobin, ferritin, soluble transferrin receptor, serum iron, hepcidin, erythropoietin (EPO), IL-6, and C-reactive protein were assessed in maternal and cord blood. RESULTS: At birth, 21% of the neonates were anemic (Hb < 13.0 g/dl) and 25% had low iron stores (ferritin < 76 µg/l). Cord serum ferritin concentrations were not significantly associated with gestational age (GA) at birth across the range of 37-42 wk. Neonates born to mothers with ferritin < 12 µg/l had significantly lower ferritin (P = 0.003) compared to their counterparts. Hepcidin and IL-6 were significantly (P < 0.05) higher in neonates born to mothers with longer durations of active labor. CONCLUSION: Given the importance of the iron stores at birth on maintenance of iron homeostasis over early infancy, additional screening of iron status at birth is warranted among those born to this high risk obstetric population.

Central auditory processing disorder profile in premature and term infants.

OBJECTIVE: The aim of this study is to compare central auditory processing disorder (CAPD) profile between children born prematurely and at term. METHODS: A retrospective study involving children 7 to 13 years of age who were referred for CAPD evaluation over the past 3 years. Parental reports and medical records were used to collect information. Children with a score ≥ two standard deviations below the mean for at least one ear on at least two different CAPD tests were considered to have CAPD. RESULTS: A total of 82 children were evaluated for CAPD of which 22 met exclusion criteria, resulting in 60 children with CAPD (15 premature and 45 term). Premature children had higher prevalence of cesarean section delivery and neonatal jaundice compared with term children. Premature children had a higher total number of failed CAPD tests compared with the term children. Among CAPD tests, there was an increased frequency of abnormal Phonemic Synthesis test (PST) and decreased frequency of abnormal Staggered Spondaic Word test (SSW) among premature children compared with term children. CONCLUSION: Premature children differ in CAPD profile compared with term children. Findings suggest possible etiological differences for CAPD such as jaundice or differential susceptibility of premature children for altered PST and SSW performance when compared with the term children.

Maternal inflammation at delivery affects assessment of maternal iron status.

Pregnant adolescents (aged ≤ 18 y, n = 253) were followed from ≥ 12 wk of gestation to delivery to assess longitudinal changes in anemia and iron status and to explore associations between iron status indicators, hepcidin, and inflammatory markers. Hemoglobin, soluble transferrin receptor (sTfR), ferritin, serum iron, erythropoietin (EPO), hepcidin, C-reactive protein, interleukin-6 (IL-6), folate, and vitamin B-12 were measured, and total body iron (TBI) (milligrams per kilogram) was calculated using sTfR and ferritin values. Anemia prevalence increased from trimesters 1 and 2 (3-5%, <28 wk) to trimester 3 (25%, 33.2 ± 3.7 wk, P < 0.0001). The prevalence of iron deficiency (sTfR > 8.5 mg/L) doubled from pregnancy to delivery (7% to 14%, P = 0.04). Ferritin and hepcidin concentrations at delivery may have been elevated as a consequence of inflammation because IL-6 concentrations at delivery were 1.6-fold higher than those obtained at 26.1 ± 3.3 wk of gestation (P < 0.0001), and a positive association was found between IL-6 and both hepcidin and ferritin at delivery (P < 0.01). EPO was consistently correlated with hemoglobin (r = -0.36 and -0.43, P < 0.001), ferritin (r = -0.37 and -0.32, P < 0.0001), sTfR (r = 0.35 and 0.25, P < 0.001), TBI (r = -0.44 and -0.37, P < 0.0001), and serum iron (r = -0.22 and -0.16, P < 0.05) at mid-gestation and at delivery, respectively. EPO alone explained the largest proportion of variance in hemoglobin at 26.0 ± 3.3 wk of gestation (R(2) = 0.13, P = 0.0001, n = 113) and at delivery (R(2) = 0.19, P < 0.0001, n = 192). Pregnant adolescents are at high risk of anemia. EPO is a sensitive indicator of iron status across gestation, is not affected by systemic inflammation, and may better predict risk of anemia at term. The trial was registered at clinicaltrials.gov as NCT01019902.

Hearing function in patients living with HIV/AIDS.

OBJECTIVES: During the earlier years of the HIV/AIDS epidemic, initial reports described sensorineural hearing loss in up to 49% of individuals with HIV/AIDS. During those years, patients commonly progressed to advanced stages of HIV disease and frequently had neurological complications. However, the abnormalities on pure-tone audiometry and brainstem-evoked responses outlined in small studies were not always consistently correlated with advanced stages of HIV/AIDS. Moreover, these studies could not exclude the confounding effect of concurrent opportunistic infections and syphilis. Additional reports also have indicated that some antiretroviral medications may be ototoxic; thus, it has been difficult to make conclusions regarding the cause of changes in hearing function in HIV-infected patients. More recently, accelerated aging has been suggested as a potential explanation for the disproportionate increase in complications of aging described in many HIV-infected patients; hence, accelerated aging-associated hearing loss may also be playing a role in these patients. DESIGN: We conducted a large cross-sectional analysis of hearing function in over 300 patients with HIV-1 infection and in 137 HIV-uninfected controls. HIV-infected participants and HIV-uninfected controls underwent a 2-hr battery of hearing tests including the Hearing Handicap Inventory, standard audiometric pure-tone air and bone conduction testing, tympanometric testing, and speech reception and discrimination testing. RESULTS: Three-way analysis of variance (ANOVA) and logistic regression analysis of 278 eligible HIV-infected subjects stratified by disease stage in early HIV disease (n = 127) and late HIV disease (n = 148) and 120 eligible HIV-uninfected controls revealed no statistically significant differences among the three study groups in either overall 4-frequency pure-tone average (4-PTA) or hearing loss prevalence in either ear. Three-way ANOVA showed significant differences in word recognition scores in the right ear among groups, a significant group effect on tympanogram static admittance in both ears and a significant group effect on tympanic gradient in the right ear. There was significantly larger admittance and gradient in controls as compared to the HIV-infected group at late stage of disease. Hearing loss in the HIV-infected groups was associated with increased age and was similar to that described in the literature for the general population. Three-way ANOVA analysis also indicated significantly greater pure-tone thresholds (worse hearing) at low frequencies in HIV patients in the late stage of disease compared with HIV-uninfected controls. This difference was also found by semi-parametric mixed effects models. CONCLUSIONS: Despite reports of "premature" or "accelerated" aging in HIV-infected subjects, we found no evidence of hearing loss occurring at an earlier age in HIV-infected patients compared to HIV-uninfected controls. Similar to what is described in the general population, the probability of hearing loss increased with age in the HIV-infected subjects and was more common in patients over 60 years of age. Interestingly, HIV-infected subjects had worse hearing at lower frequencies and have significant differences in tympanometry compared to HIV-uninfected controls; these findings deserve further study.

Biomimetic nanodrug targets inflammation and suppresses YAP/TAZ to ameliorate atherosclerosis.

Atherosclerosis, a chronic inflammatory disease, is the primary cause of myocardial infarction and ischemic stroke. Recent studies have demonstrated that dysregulation of yes-associated protein (YAP) and transcriptional coactivator with PDZ-binding domain (TAZ) contributes to plaque development, making YAP/TAZ potential therapeutic targets. However, systemic modulation of YAP/TAZ expression or activities risks serious off-target effects, limiting clinical applicability. To address the challenge, this study develops monocyte membrane-coated nanoparticles (MoNP) as a targeted delivery system for activated and inflamed endothelium lining the plaque surface. The MoNP system is used to deliver verteporfin (VP), aimed at inhibiting YAP/TAZ specifically within arterial regions prone to atherosclerosis. The results reveal that MoNP significantly enhance payload delivery to inflamed endothelial cells (EC) while avoiding phagocytic cells. When administered in mice, MoNP predominantly accumulate in intima of the atheroprone artery. MoNP-mediated delivery of VP substantially reduces YAP/TAZ expression, thereby suppressing inflammatory gene expression and macrophage infiltration in cultured EC and mouse arteries exposed to atherogenic stimuli. Importantly, this targeted VP nanodrug effectively decreases plaque development in mice without causing noticeable histopathological changes in major organs. Collectively, these findings demonstrate a lesion-targeted and pathway-specific biomimetic nanodrug, potentially leading to safer and more effective treatments for atherosclerosis.

Latent iron deficiency in utero is associated with abnormal auditory neural myelination in ≥ 35 weeks gestational age infants.

OBJECTIVE: To determine whether cord serum ferritin level is associated with auditory brainstem evoked response interpeak latencies, an index of auditory neural myelination, in infants at ≥ 35 weeks gestational age (GA). STUDY DESIGN: This prospective study compared auditory neural myelination in infants with latent iron deficiency (cord serum ferritin, 11-75 ng/mL) and infants with normal iron status (cord serum ferritin, >75 ng/mL) at birth. Our inclusion criteria were infants born at ≥ 35 weeks GA who had cord blood collected soon after birth and had 1 or more of the following risk factors for poor in utero iron status: maternal diabetes mellitus, pregnancy-induced hypertension, and intrauterine growth restriction. Cord serum ferritin level was measured using the chemiluminescence immunoassay method. Auditory brainstem evoked response was measured using 80-dB normal hearing level click stimuli at a rate of 69.9/second within 48 hours after birth to evaluate interpeak latencies, a measure of nerve conduction velocity or myelination. RESULTS: Of the 45 infants studied, 12 had latent iron deficiency. On repeated-measures ANCOVA using interpeak latencies I-III, III-V, and I-V as multiple outcomes, infants with latent iron deficiency had significantly prolonged interpeak latencies (P = .01) compared with infants with normal iron status after controlling for confounders. CONCLUSION: In utero latent iron deficiency is associated with abnormal auditory neural myelination at birth in infants born at ≥ 35 weeks GA.

The association of auditory function measures with low-level methylmercury from oceanic fish consumption and mercury vapor from amalgam: The Seychelles Child Development Study Nutrition 1 Cohort.

BACKGROUND: Some authors have reported that low-level exposure to methylmercury (MeHg) adversely impacts measures of auditory function. These reports, however, are not consistent in their findings. Consequently, we examined auditory function in a population exposed to low-level methylmercury (MeHg) exposure from fish consumption and to mercury vapor (Hg0) from dental amalgams. We analyzed their associations with the participants hearing acuity, absolute and interwave ABR latencies, and otoacoustic emissions (distortion product/DPOAE and click evoked/CEOAE). DESIGN: We administered an audiometry test battery to 246 participants from the Seychelles Child Development Study (SCDS) Nutrition Cohort 1 (NC1) at 9 years of age. The test battery included standard pure-tone audiometry, tympanometry, Auditory Brainstem Responses (ABR) and Distortion Product and Click Evoked Otoacoustic Emissions (DPOAE and CEOAE) testing. We measured prenatal MeHg exposure in maternal hair and postnatal MeHg in children's hair. We approximated prenatal Hg0 exposure using maternal amalgam surface area and postnatal Hg0 using children amalgam surface area. Complete exposure records and audiometric data were available on 210 participants and in them we analyzed the association of MeHg and Hg0 exposures with auditory outcomes using covariate-adjusted linear regression models adjusted for sex and tympanometric pressure. RESULTS: Hg exposures were similar for both sexes. Seven of the 210 evaluable participants examined had either a mild (5) or moderate (2) hearing loss. Four had a mild monaural hearing loss and 3 had either a mild (1) or moderate (2) bilateral hearing loss. No participant had greater than a moderate hearing loss in either ear. Hg exposures were higher in participants with either a mild or moderate hearing loss, but these differences were not statistically significant. Among the 210 with complete data, neither prenatal nor postnatal MeHg nor Hg0 exposure was statistically significantly associated with any of the ABR endpoints (p > 0.05 for all 72 associations). Neither prenatal nor postnatal Hg0 exposure was associated with any of the OAE endpoints (p > 0.05). MeHg exposure was statistically associated with 6 of the 56 DPOAE endpoints (p-values between 0.0001 and 0.023), but none of the 40 CEOAE endpoints. Two of the associations occurred with prenatal MeHg exposures and 1 of those would suggest a beneficial effect. Four of the other associations occurred with postnatal MeHg exposures with only 2 found in left ears of both males and females and the other 2 in the left and right ear of females at only one frequency. CONCLUSION: Overall, these data do not present a clear and consistent pattern to suggest that the auditory system is negatively affected by low-level methylmercury exposure due to dietary consumption of oceanic fish or mercury vapor exposure from dental amalgams.

The effects of aggressive vs. conservative phototherapy on the brainstem auditory evoked responses of extremely-low-birth-weight infants.

INTRODUCTION: This study was a two-center, stratified, parallel-group randomized trial comparing the effects of aggressive vs. conservative phototherapy on brainstem auditory evoked response (BAER) latencies in infants with extremely low birth weight (ELBW, ≤ 1,000 g). RESULTS: BAER latencies of 751-1,000 g birth-weight infants were shorter by 0.37 ms (95% confidence interval (CI) = 0.02, 0.73) for wave V, 0.39 ms (0.08, 0.70) for wave III, and 0.33 ms (0.01, 0.65) for wave I after aggressive phototherapy at one center. Interwave intervals did not differ significantly. Similar nonsignificant trends were recorded for 501-750 g birth-weight infants. At the other participating center, no significant differences were recorded, cautioning against overgeneralizing these results. DISCUSSION: The effects of bilirubin on the auditory pathway in ELBW infants depend on a complex interaction of bilirubin exposure, newborn characteristics, and clinical management. METHODS: Aggressive phototherapy was initiated sooner and continued at lower bilirubin levels than conservative phototherapy. A total of 174 ELBW infants were enrolled in the study; 111 infants were successfully tested at 35 weeks postmenstrual age (PMA); 57 died; and 6 were not successfully tested.

Optimum click rate for neurodevelopmental evaluation using auditory brainstem response in premature infants.

OBJECTIVE: To determine the optimal click rate (CR) for neurodevelopmental assessment using auditory brainstem evoked response (ABR) in preterm infants. STUDY DESIGN: A prospective study was performed in 17 preterm infants at 34 weeks' postmenstrual age. Three separate ABRs were performed a few minutes apart on each subject using three different click rates (CRs): 19.9/s, 29.9/s, and 69.9/s. An ABR response with waves I, III, and V identifiable and measurable was defined as a pass response. The CR associated with the highest frequency of pass responses was considered optimal, or if two CRs were tied for the highest frequency, then the faster of the two CR was deemed best. RESULTS: The frequency of pass responses for 29.9/s and 19.9/s CR was 100% and was significantly higher compared with 82% frequency with 69.9/s CR. There was no difference in latencies, interpeak latencies, and amplitudes of waves between 19.9/s and 29.9/s CR; however, standard deviations of interpeak latencies were larger with 19.9/s compared with 29.9/s CR. CONCLUSION: Our data suggest that 29.9/s is the optimal CR for neurodevelopmental assessment using ABR. Because of smallest variance in interpeak latencies, the sample size requirement will be lowest using 29.9/s CR with secondary reduction in cost and time.

Tone in Noise Detection in Children with a History of Temporary Conductive Hearing Loss.

Children with a history of temporary conductive hearing loss (CHL) during early development may show long-term impairments in auditory processes that persist after restoration of normal audiometric hearing thresholds. Tones in noise provide a simplified paradigm for studying hearing in noise. Prior research has shown that adults with sensorineural hearing loss may alter their listening strategy to use single-channel energy cues for tone-in-noise (TIN) detection rather than rove-resistant envelope or spectral profile cues. Our objective was to determine the effect of early CHL on TIN detection in healthy children compared to controls. Children ages 4-7 years, with and without a history of CHL due to otitis media with effusion (OME) before age 3 years, participated in a two-alternative forced choice TIN detection task. Audiometric thresholds were normal at the time of testing. Thresholds for detection of a 1000 Hz tone were measured in fixed-level noise and in roving-level noise that made single-channel energy cues unreliable. Participants included 23 controls and 23 with a history of OME-related CHL. TIN thresholds decreased with increasing age across participants. Children in both groups showed similar TIN sensitivity and little or no threshold elevation in the roving-level condition compared to fixed-level tracks, consistent with use of rove-resistant cues. In contrast to older listeners with sensorineural hearing loss, there was no detectable change in TIN sensitivity with roving level for children with a history of OME-related CHL.

Placental expression of the heme transporter, feline leukemia virus subgroup C receptor, is related to maternal iron status in pregnant adolescents.

Little is known about the expression of heme transporters in human placenta and possible associations between these transporters and maternal or neonatal iron status. To address this area of research, relative protein expression of 2 heme transporters, Feline Leukemia Virus, Subgroup C, Receptor 1 (FLVCR1) and Breast Cancer Resistance Protein (BCRP), was assessed using Western-blot analysis in human placental tissue in relation to maternal/neonatal iron status and placental iron concentration. Placental FLVCR1 (n = 71) and BCRP (n = 83) expression were assessed at term (36.6-41.7 wk gestation) in a cohort of pregnant adolescents (13-18 y of age) at high-risk of iron deficiency. Both FLVCR1 and BCRP were detected in all placental samples assayed. Placental FLVCR1 expression was positively related to placental BCRP expression (n = 69; R(2) = 0.104; P < 0.05). Adolescents that were anemic at delivery had lower placental FLVCR1 expression (n = 49; P < 0.05). Placental FLVCR1 expression was positively associated with placental iron concentration at delivery (n = 61; R(2) = 0.064; P < 0.05). In contrast, placental BCRP expression was not significantly associated with maternal iron status or placental iron content. Both FLVCR1 and BCRP are highly expressed in human placental tissue, but only FLVCR1 was significantly inversely associated with maternal iron status and placental iron concentration. Further analysis is needed to explore potential functional roles of FLVCR1 in human placental iron transport.

Depressive symptoms and social context modulate oxytocin's effect on negative memory recall.

Oxytocin promotes social affiliation across various species, in part by altering social cognition to facilitate approach behaviour. However, the effects of intranasal oxytocin on human social cognition are mixed, perhaps because its effects are context dependent and subject to inter-individual differences. Few studies have included explicit manipulations of social context to test this supposition. We examined oxytocin's effects on autobiographical memory recall in two contexts, with and without social contact, and evaluated whether these effects were moderated by depressive symptoms. Two non-clinical samples (Study 1, n = 48; Study 2, n = 63) completed randomised, placebo-controlled, within-subject experiments. We assessed autobiographical memory recall across two sessions (intranasal oxytocin or placebo) and two contexts (memories elicited by an experimenter or by computer). Overall, intranasal oxytocin increased ratings of the vividness of recalled memories during the social context only. Individuals with elevated depressive symptoms also recalled memories that were more negative following oxytocin relative to placebo only in the non-social context across the two studies. Findings highlight the negative consequences of increasing oxytocin bioavailability in vulnerable persons in the absence of social contact. Contextual factors such as social isolation among depressed populations may complicate the clinical use of oxytocin.

Improved Parent-Child Interactions Predict Reduced Internalizing Symptoms Among the Offspring of Parents with Bipolar Disorder Undergoing a Prevention Program: A Proof-of-Concept Study.

The offspring of parents with bipolar disorder (OBD) exhibit elevated rates of psychopathology. However, preventative interventions are lacking. Using a quasi-experimental design with an assessment-only control group, we examined if a 12-week program (entitled Reducing Unwanted Stress in the Home, RUSH) decreases internalizing and externalizing symptoms in the OBD (aged 6-11 years) via intervention-related gains in parent-child interaction quality. Participants consisted of 55 offspring (26 OBD; 29 controls) and their parents. Assessments were conducted at four time points up to six months following the end of the RUSH program, during which parent and teacher ratings of child symptoms, and parent-child interaction quality (parental positivity and negativity, and dyadic mutuality) were measured. Multilevel modelling showed improved parental positivity and negativity, and dyadic mutuality among target dyads immediately and six months post-intervention. For the bootstrapping mediation analyses, intervention-related change in parental negativity fully mediated the relations between having participated in the RUSH program and lower parent-reported internalizing problems among the OBD six months later. These data provide evidence of the efficacy of the RUSH program for OBD who exhibited improved interactions with their parents post-intervention. Further investigation via a randomized controlled trial is warranted.

In utero iron status and auditory neural maturation in premature infants as evaluated by auditory brainstem response.

OBJECTIVE: To determine whether cord ferritin (CF) concentration, an index of in utero iron status, is associated with auditory neural maturation in premature infants. STUDY DESIGN: A prospective cohort study was performed to compare auditory neural maturation in infants with latent iron deficiency (CF 11-75 ng/mL) and infants with normal iron status (CF > 75 ng/mL) at birth. Our inclusion criteria were infants of 27-33 weeks gestational age who were admitted to the neonatal intensive care unit between July 2007 and November 2008 within 12 hours after birth and had cord blood collected. Infants with TORCH infections (toxoplasmosis, other infections, rubella, cytomegalovirus infection, and herpes simplex), chromosomal disorders, craniofacial anomalies, culture-proven sepsis, and/or unstable conditions were excluded. CF level was measured using a chemiluminescence immunoassay method. Bilateral monaural auditory brainstem evoked response (ABR) was assessed using 80-dB nHL click stimuli at a repetition rate of 29.9/seconds within 48 hours after birth. RESULTS: Of the 80 infants studied, 35 had latent iron deficiency. After controlling for confounders, the infants with latent iron deficiency had significantly prolonged absolute wave latencies I, III, and V and decreased frequency of mature ABR waveforms compared with the infants with normal iron status. CONCLUSION: Premature infants with in utero latent iron deficiency have abnormal auditory neural maturation compared with infants with normal in utero iron status.

Protein Timing Does Not Affect Next-Day Recovery of Strength or Power but May Enhance Aerobic Adaptations to Short-Term Variable Intensity Exercise Training in Recreationally Active Males: A Pilot Study.

Background: Variable intensity training (VIT) characteristic of stop-and-go team sport exercise may reduce performance capacity when performed on successive days but also represent a strategy to induce rapid training-induced increases in exercise capacity. Although post-exercise protein enhances muscle protein synthesis, the timing of protein ingestion following variable intensity training (VIT) on next-day recovery and short-term performance adaptation is unknown. Purpose: To determine if immediate (IMM) as compared to delayed (DEL) protein ingestion supports greater acute recovery of exercise performance during successive days of VIT and/or supports chronic training adaptations. Methods: Sixteen habitually active men performed 5 consecutive days of variable intensity training (VIT) in the evening prior to consuming a beverage providing carbohydrate and whey protein (IMM; 0.7 g and 0.3 g/kg, respectively) or carbohydrates alone (DEL; 1 g/kg) with the reciprocal beverage consumed the following morning. Performance was assessed before each VIT (recovery) and 2 days after the final VIT (adaptation). Results: Five consecutive days of VIT progressively decreased anaerobic peak power (~7%) and muscle strength (MVC; ~8%) with no impact of protein timing. Following 2 days of recovery, VIT increased maximal voluntary contraction and predicted VO2peak by ~10 and ~5%, respectively, with a moderate beneficial effect of IMM on predicted VO2peak (ES = 0.78). Conclusion: Successive days of simulated team sport exercise decreases markers of next-day performance capacity with no effect of protein timing on acute recovery. However, practical VIT increases muscle strength and aerobic capacity in as little as 5 days with the latter potentially enhanced by immediate post-exercise protein consumption.

Association of Audiometric Measures with plasma long chain polyunsaturated fatty acids in a high-fish eating population: The Seychelles Child Development Study.

OBJECTIVES: To determine if auditory function is associated with current long chain polyunsaturated fatty acids (LCPUFA) concentrations in a cohort of young adults who consume oceanic fish with naturally acquired methylmercury (MeHg). We measured participants plasma LCPUFA concentrations (total n-3, total n-6 and the n-6:n-3 ratio) and looked for an association with Auditory Brain Response (ABR) latencies and Otoacoustic Emissions (OAE) amplitudes. DESIGN: Auditory function of 534 participants from the Seychelles Child Development Study (SCDS) main cohort was examined at 19 years of age. Tests included standard pure-tone audiometry, tympanometry, ABR and both Click-Evoked OAE (CEOAE) and Distortion-Product OAE (DPOAE). Associations of LCPUFA status, measured at the time of examination, and auditory outcomes were examined using covariate-adjusted linear regression models. All models were adjusted for sex, prenatal and current MeHg exposure and hearing status. RESULTS: LCPUFA concentrations were similar for both sexes and when comparing participants with normal hearing (90.4 %) to those who had a sensorineural hearing loss in one or both ears (9.6 %). When looking at a subset of only hearing impaired participants, LCPUFA concentrations were similar in those participants who had a mild sensorineural hearing loss as compared with participants that had a moderate sensorineural hearing loss. LCPUFA concentrations were not correlated with current hair MeHg. LCPUFA concentrations were statistically significantly associated with only 6 of 174 ABR and OAE endpoints examined. Four of the 6 significant associations were present in only one sex. In female participants as n-6 concentrations increased, the ABR wave I absolute latency increased for a 60 dBnHL 19 click/sec stimulus. For male participants the interwave I-III latencies for a 60 dBnHL 69 clicks/sec stimulus increased as the n-6:n-3 LCPUFA ratio increased and the interwave I-V interval decreased for a 60 dBnHL 39 clicks/sec stimulus as the n-6 concentration increased. For both sexes interwave latencies were prolonged for the III-V interwave interval for an 80 dBnHL 39 clicks/sec as n-3 LCPUFA concentration increased. As the n-3 LCPUFA concentrations increased, the amplitude of the 6000 Hz DPOAE in the right ear increased for both sexes. As the n-6:n-3 ratio increased, the amplitude of the 1500 Hz DPOAE in the left ear decreased for females. The amplitude of the CEOAE was not associated with n-3, n-6 LCPUFA concentrations or the n-6:n-3 ratio. CONCLUSION: There was no evidence to suggest LCPUFA status was associated with hearing acuity, ABR latencies or OAE amplitudes, even though our participants tended to have higher LCPUFA concentrations as compared to individuals consuming a more western diet. No association was observed between LCPUFA status and a participants hearing status (normal hearing or hearing loss). Although we found a few associations between current plasma LCPUFA status and ABR and OAE auditory endpoints examined, no clear pattern exists. Some of these associations would be considered detrimental resulting in prolonged ABR latencies or smaller OAE amplitudes, while others would be considered beneficial resulting in shortened ABR latencies or larger OAE amplitudes.

Amplitude Modulation Detection in Children with a History of Temporary Conductive Hearing Loss Remains Impaired for Years After Restoration of Normal Hearing.

Otitis media with effusion (OME) is considered a form of relative sensory deprivation that often occurs during a critical period of language acquisition in children. Animal studies have demonstrated that hearing loss during early development can impair behavioral sensitivity to amplitude modulation (AM), critical for speech understanding, even after restoration of normal hearing thresholds. AM detection in humans with a history of OME-associated conductive hearing loss (CHL) has not been previously investigated. Our objective was to determine whether OME-associated CHL in children ages 6 months to 3 years results in deficits in AM detection in later childhood, after restoration of normal audiometric thresholds. Children ages 4 to 7 years with and without a history of OME-associated CHL participated in an AM detection two-alternative forced-choice task at 8 and 64 Hz modulation frequencies using a noise carrier signal and an interactive touch screen interface. Thirty-four subjects were studied (17 with a history of OME-related CHL and 17 without). Modulation detection thresholds improved with age and were slightly lower (more sensitive) for the 64 Hz modulation frequency for both groups. Modulation detection thresholds of children with a history of OME-associated CHL were higher than control thresholds at 5 years, but corrected to expected levels between ages 6-7. OME-associated CHL results in impaired AM detection, even when measured years after restoration of normal audiometric thresholds. Future studies may shed light on implications for speech and language development and academic success for children affected by OME and associated conductive hearing loss.

Chronic Auditory Toxicity in Late Preterm and Term Infants With Significant Hyperbilirubinemia.

BACKGROUND AND OBJECTIVES: Significant hyperbilirubinemia (SHB) may cause chronic auditory toxicity (auditory neuropathy spectrum disorder and/or sensorineural hearing loss); however, total serum bilirubin (TSB) does not discriminate neonates at risk for auditory toxicity. Our objective was to compare TSB, bilirubin albumin molar ratio (BAMR), and unbound bilirubin (UB) for their association with chronic auditory toxicity in neonates with SHB (TSB ≥20 mg/dL or TSB that met criteria for exchange transfusion). METHODS: Infants ≥34 weeks' gestational age (GA) with SHB during the first 2 postnatal weeks were eligible for a prospective longitudinal study in India. Comprehensive auditory evaluations were performed at 2 to 3 months of age by using auditory brainstem response, tympanometry, and an otoacoustic emission test and at 9 to 12 months of age by using audiometry. The evaluations were performed by an audiologist unaware of the degree of jaundice. RESULTS: A total of 93 out of 100 infants (mean GA of 37.4 weeks; 55 boys, 38 girls) who were enrolled with SHB were evaluated for auditory toxicity. Of those, 12 infants (13%) had auditory toxicity. On regression analysis controlling for covariates, peak UB (but not peak TSB or peak BAMR), was associated with auditory toxicity (odds ratio 2.41; 95% confidence interval: 1.43-4.07; P = .001). There was significant difference in the area under the receiver operating characteristic curves between UB (0.866), TSB (0.775), and BAMR (0.724) for auditory toxicity (P = .03) after controlling for covariates. CONCLUSIONS: Unconjugated hyperbilirubinemia indexed by UB (but not TSB or BAMR) is associated with chronic auditory toxicity in infants ≥34 weeks' GA with SHB.