An aid to accurate skin closure.
Explore the source record for details and available documents.
Dermatologic Surgical Procedures↗
Biomedical subjects
D Bryant
Publications and source records attributed to D Bryant.
Plasma choline in normal newborns, infants, toddlers, and in very-low-birth-weight neonates requiring total parenteral nutrition.
Choline deficiency is associated with hepatic abnormalities in adult volunteers and patients administered total parenteral nutrition (TPN). Preliminary investigation has suggested that plasma-free choline concentration (PFCh) is greater in neonatal animals, including humans, than in adults. The aims of this study were to determine the normal PFCh and phospholipid-bound choline concentration (PPLBCh) for newborns, infants, and toddlers and to determine the change during TPN. We also sought to determine the degree of fetal choline extraction, the relation between maternal and newborn plasma choline concentrations, and the relation between plasma choline status and normal newborn length, weight, and gestational age. Blood samples were obtained from 104 full-term newborns in two centers (Ben Taub and Maimonides), 25 mothers, 21 normal infants aged 20.3 +/- 11.8 wk, 12 normal infants aged 62.4 +/- 3.9 wk, and 14 preterm infants (gestational age = 28.9 +/- 2.2 wk) who required TPN. The vein PFChs were 28.1 +/- 13.0 nmol/mL (Ben Taub) and 68.1 +/- 16.9 nmol/mL (Maimonides). The artery PFChs were 27.1 +/- 13.0 nmol/mL (Ben Taub) and 57.9 +/- 11.6 nmol/mL (Maimonides). The vein PPLChs were 1004.7 +/- 246.6 nmol/mL (Ben Taub) and 1121.2 +/- 289.6 nmol/mL (Maimonides). The artery PPLChs were 1065.7 +/- 469.3 nmol/mL (Ben Taub) and 1106.9 +/- 285.8 nmol/mL (Maimonides). The vein-minus-artery differences for PFCh were 1.0 +/- 9.7 nmol/mL (Ben Taub) and 10.2 +/- 10.9 nmol/mL (Maimonides). The vein-minus-artery differences for PPLCh were -51.9 +/- 398.2 nmol/mL (Ben Taub General Hospital, Houston, Texas) and 14.4 +/- 254.3 nmol/mL (Maimonides, New York, New York). Maternal venous PFCh was 8.4 +/- 3.1 nmol/mL. Maternal venous PPLCh was 2592.1 +/- 584.0 nmol/mL (range = 1227.8-3729.0). Maternal venous PFCh correlated with newborn arterial PFCh (r = 0.53, P < 0.05) but not with newborn venous PFCh. No correlation was seen between maternal venous and newborn PPLCh. No significant differences were seen in PPLCh or choline extraction in Ben Taub versus Maimonides patients, although PFCh was significantly greater in the newborns from Maimonides (P < 0.05). The mean venous PFCh and PPLCh in the preterm infants before beginning TPN was 21.2 +/- 6.3 and 1366.8 +/- 339.1 nmol/mL, respectively. Just before initiation of tube feeding (4.0 +/- 2.7 d after TPN had been started), mean venous PFCh and PPLCh was 18.4 +/- 5.3 and 2251.8 +/- 686.9 nmol/mL, respectively. When TPN was discontinued and tube feeding increased to goal, after 10.8 +/- 10.4 d, venous PFCh and PPLCh was 22.6 +/- 8.7 and 2072.5 +/- 540.6 nmol/mL, respectively. Venous PFCh and PPLCh was 13.4 +/- 2.5 and 1827.5 +/- 327.0 nmol/mL, respectively in the older infant group. In conclusion, newborn PFCh is significantly greater than PFCh in adults but falls to adult levels within the first year of life. Low maternal PFCh may be associated with low newborn PFCh. Normal newborn plasma choline status has no bearing on intrauterine growth, although the role of maternal choline deficiency in underweight newborns is unknown. Newborn PPLCh is substantially below that of adults, which suggests its use in membrane synthesis during growth.
Adult↗
Analysis of N-linked oligosaccharides: progress towards the characterisation of glycoprotein-linked carbohydrates.
The covalent attachment of carbohydrate to proteins is a very common co- or post-translational event in the biosynthesis of glycoproteins. The type and heterogeneity of these oligosaccharides can affect a range of physico-chemical and biological properties of a glycoprotein. Thus the development of sensitive, reliable and robust analytical methods for carbohydrate analysis is important in the pharmaceutical industry, especially in the recombinant production of experimental and therapeutic glycoproteins. In this report we have reviewed methodology for the in-gel enzymatic release of N-linked oligosaccharides from glycoproteins separated by electrophoresis. These oligosaccharides are derivatised by reductive amination using 3-acetamido-6-aminoacridine (AA-Ac), a novel, highly fluorescent probe. A major advantage of this technique is that glycan derivatives are amenable to analysis by an array of chromatographic and mass spectrometric methods, allowing the resolution and characterisation of a wide variety of glycan structures. It is hoped that in due course the methodology described will be applied to proteomics studies, especially in identifying the role of carbohydrate in protein function and disease.
Animals↗
Overt and covert dimensions of antisocial behavior in early childhood.
The present study was designed to assess both the prevalence and structure of antisocial behavior in a normative sample of preschoolers. Prevalence estimates suggested that 40% of preschoolers exhibit at least one antisocial behavior each day. Furthermore, 10% of preschoolers exhibit six or more antisocial behaviors each day. Consistent with research based on older children, factor analyses provided support for conceptualizing antisocial behavior in early childhood as consisting of both overt and covert dimensions. While both overt and covert behaviors had acceptable test-retest reliability, only overt behaviors had acceptable interrater reliability. Finally both overt and covert dimensions of antisocial behavior were uniquely related to general measures of conduct problems, hyperactivity, and adult and peer conflict in the classroom setting. Findings are discussed with regard to early assessment and the developmental course of antisocial behavior.
Adult↗
The influence of expertise and task factors on age differences in pilot communication.
The influence of expertise and task factors on age differences in a simulated pilot-Air Traffic Control (ATC) communication task was examined. Young, middle-aged, and older pilots and nonpilots listened to ATC messages that described a route through an airspace, during which they referred to a chart of this airspace. Participants read back each message and then answered a probe question about the route. It was found that pilots read back messages more accurately than nonpilots, and younger participants were more accurate than older participants. Age differences were not reduced for pilots. Pilots and younger participants also answered probes more accurately, suggesting that they were better able to interpret the ATC messages in terms of the chart in order to create a situation model of the flight. The findings suggest that expertise benefits occur for adults of all ages. High levels of flying experience among older pilots (as compared with younger pilots) helped to buffer age-related declines in cognitive resources, thus providing evidence for the mediating effects of experience on age differences.
Adult↗
Demographic and intrapartum characteristics of term pregnancies with early-onset neonatal seizures.
OBJECTIVE: To compare the demographic and intrapartum factors of term pregnancies in which early-onset neonatal seizures developed with the characteristics of a large, unselected control population. STUDY DESIGN: Pregnancies delivered at term (gestational age > or = 37 weeks) in one birthing unit between 1984 and 1995 with a discharge diagnosis of neonatal seizures were identified. Maternal and neonatal charts of these patients were reviewed to confirm the diagnosis of early-onset seizure (EOS) which was defined as a clinical or EEG-diagnosed seizure within 72 hours of life. Demographic and intrapartum factors were compared between these EOS cases and all singleton term pregnancies delivered over the same time period in which there was no EOS. A regression model was then developed to determine factors predictive of EOS. RESULTS: Of 80,561 total deliveries during the 11-year study period, there were 64,340 control and 62 EOS (0.1%) deliveries. Regression modeling identified NICU admission, depressed 1- and 5-minute Apgar scores, and neonatal intubation as predictors of EOS, but not operative vaginal, vaginal breech, or cesarean delivery. CONCLUSION: Depressed condition at birth and/or the requirement for NICU care was the most important risk associated with early seizures in term infants.
Adult↗
Promoter methylation and silencing of the retinoic acid receptor-beta gene in lung carcinomas.
BACKGROUND: Retinoic acid plays an important role in lung development and differentiation, acting primarily via nuclear receptors encoded by the retinoic acid receptor-beta (RARbeta) gene. Because receptor isoforms RARbeta2 and RARbeta4 are repressed in human lung cancers, we investigated whether methylation of their promoter, P2, might lead to silencing of the RARbeta gene in human lung tumors and cell lines. METHODS: Methylation of the P2 promoter from small-cell lung cancer (SCLC) and non-small-cell lung cancer (NSCLC) cell lines and tumor samples was analyzed by the methylation-specific polymerase chain reaction (PCR). Expression of RARbeta2 and RARbeta4 was analyzed by reverse transcription-PCR. Loss of heterozygosity (LOH) was analyzed by PCR amplification followed by electrophoretic separation of PCR products. Statistical differences were analyzed by Fisher's exact test with continuity correction. RESULTS: The P2 promoter was methylated in 72% (63 of 87) of SCLC and in 41% (52 of 127) of NSCLC tumors and cell lines, and the difference was statistically significant (two-sided P:<.001). By contrast, in 57 of 58 control samples, we observed only the unmethylated form of the gene. Four tumor cell lines with unmethylated promoter regions expressed both RARbeta2 and RARbeta4. Four tumor lines with methylated promoter regions lacked expression of these isoforms, but demethylation by exposure to 5-aza-2'-deoxycytidine restored their expression. LOH at chromosome 3p24 was observed in 100% (13 of 13) of SCLC lines and 67% (12 of 18) of NSCLC cell lines, and the difference was statistically significant (two-sided P: =.028). CONCLUSIONS: Methylation of the RARbeta P2 promoter is one mechanism that silences RARbeta2 and RARbeta4 expression in many lung cancers, particularly SCLC. Chemical demethylation is a potential approach to lung cancer therapy.
Carcinoma, Non-Small-Cell Lung↗
Nociceptin/orphanin FQ (N/OFQ) induces a quasi-morphine abstinence syndrome in the rat.
Nociceptin/orphanin FQ (N/OFQ) is a neuropeptide that exerts antiopiate effects under some circumstances, and there is evidence that it contributes to opiate tolerance. This raises the question, might N/OFQ also contribute to opiate dependence and abstinence? Twenty-two male Sprague-Dawley rats were cannulated in the third ventricle and challenged 7 days later by third ventricle injection of 50, 200 or 1,000 ng N/OFQ or saline alone. Each rat was observed under "blind" conditions for 30 min beginning 15 min after onset of the third ventricle injection. There was a significant positive linear trend of signs as a function of N/OFQ dose. Subjects receiving saline had 18.0+/-2.0 (mean+/-SEM) overall abstinence-like signs, whereas subjects receiving 50, 200 or 1000 ng N/OFQ had 35.2+/-3.6, 49.8+/-2.6 and 63.5+/-9.7 signs, respectively. In 16 additional rats, abstinence-like signs induced by 1000 ng N/OFQ were significantly attenuated by low SC doses of morphine or clonidine. These results raise the possibility that N/OFQ might contribute to opiate dependence and subsequent abstinence syndrome. On the other hand, N/OFQ over a wide dose range induced abstinence signs with similar potency in morphine dependent and non-dependent rats.
Animals↗
Type IV pilus biogenesis and motility in the cyanobacterium Synechocystis sp. PCC6803.
We have recently shown that phototactic movement in the unicellular cyanobacterium Synechocystis sp. PCC6803 requires type IV pilins. To elucidate further type IV pilus-dependent motility, we inactivated key genes implicated in pilus biogenesis and function. Wild-type Synechocystis sp. PCC6803 cells have two morphologically distinct pilus types (thick and thin pili). Of these, the thick pilus morphotype, absent in a mutant disrupted for the pilin-encoding pilA1 gene, appears to be required for motility. The thin pilus morphotype does not appear to be altered in the pilA1 mutant, raising the possibility that thin pili have a function distinct from that of motility. Mutants disrupted for pilA2, which encodes a second pilin-like protein, are still motile and exhibit no difference in morphology or density of cell-surface pili. In contrast, inactivation of pilD (encoding the leader peptidase) or pilC (encoding a protein required for pilus assembly) abolishes cell motility, and both pilus morphotypes are absent. Thus, the PilA1 polypeptide is required for the biogenesis of the thick pilus morphotype which, in turn, is necessary for motility (hence we refer to them as type IV pili). Furthermore, PilA2 is critical neither for motility nor for pilus biogenesis. Two genes encoding proteins with similarity to PilT, which is considered to be a component of the motor essential for type IV pilus-dependent movement, were also inactivated. A pilT1 mutant is (i) non-motile, (ii) hyperpiliated and (iii) accumulates higher than normal levels of the pilA1 transcript. In contrast, pilT2 mutants are motile, but are negatively phototactic under conditions in which wild-type cells are positively phototactic.
Amino Acid Sequence↗
Early eukaryote evolution based on mitochondrial gene order breakpoints.
The comparison of the gene orders in a set of genomes can be used to infer their phylogenetic relationships and to reconstruct ancestral gene orders. For three genomes this is done by solving the "median problem for breakpoints"; this solution can then be incorporated into a routine for estimating optimal gene orders for all the ancestral genomes in a fixed phylogeny. For the difficult (and most prevalent) case where the genomes contain partially different sets of genes, we present a general heuristic for the median problem for induced breakpoints. A fixed-phylogeny optimization based on this is applied in a phylogenetic study of a set of completely sequenced protist mitochondrial genomes, confirming some of the recent sequence-based groupings which have been proposed and, conversely, confirming the usefulness of the breakpoint method as a phylogenetic tool even for small genomes.
Biological Evolution↗
Changing an ostomy appliance.
Explore the source record for details and available documents.
Bandages↗
Increased cardiomyocyte intracellular calcium during endotoxin-induced cardiac dysfunction in guinea pigs.
Septic shock is a complex pathophysiologic state characterized by circulatory insufficiency, multiple system organ dysfunction, and frequent mortality. Although profound cardiac dysfunction occurs during sepsis, the pathogenesis of this dysfunction remains poorly understood. To determine whether abnormalities in intramyocyte calcium accumulation might contribute to the development of cardiac dysfunction, we measured myocyte intracellular calcium during peak cardiac dysfunction after an endotoxin challenge. Intraperitoneal administration of Escherichia coli lipopolysaccharide 4 mg/kg to adult guinea pigs resulted in significantly impaired cardiac performance (Langendorff preparation) 18 h after challenge compared with control. This included diminished left ventricular pressure development (56 +/- 7 versus 95 +/- 4 mm Hg, p < 0.05), maximal rate of left ventricular pressure rise (998 +/- 171 versus 1784 +/- 94 mm Hg/s, p < 0.05) and left ventricular pressure fall (1014 +/- 189 versus 1621 +/- 138 mm Hg/s, p < 0.05). Assay of intracellular calcium in fura-2AM-loaded cardiac myocytes demonstrated increased intracellular calcium concentration in myocytes obtained from lipopolysaccharide-challenged animals compared with controls (234 +/- 18 versus 151 +/- 6 nM, p < 0.05). Inhibition of calcium-release channel (ryanodine receptor) opening by administration of dantrolene prevented the increase in intracytoplasmic calcium (159 +/- 8 versus 234 +/- 18 nM, p < 0.05) and partially ameliorated systolic and diastolic ventricular dysfunction. These data indicate that abnormalities of intracellular calcium contribute to the development of endotoxin-induced myocardial dysfunction.
Animals↗
Magnetic resonance imaging and invasive evaluation of development of heart failure in transgenic mice with myocardial expression of tumor necrosis factor-alpha.
BACKGROUND: Transgenic mice expressing tumor necrosis factor-alpha (TNF-alpha) in cardiac myocytes develop dilated cardiomyopathy, but the temporal progression to cardiac dysfunction is not well characterized. We asked (1) Does magnetic resonance imaging (MRI) provide a reproducible assessment of cardiac output in mice that correlates with invasive measurements obtained with thermodilution? (2) What is the time course of left ventricular (LV) remodeling in transgenic mice with myocardial expression of TNF-alpha? METHODS AND RESULTS: Transgenic mice from 2 different lineages with differing amounts of myocardial TNF-alpha expression [lineage 1 (L1) and lineage 2 (L2)] and littermate controls (LC) were studied. In protocol 1, cardiac output (CO) and stroke volume (SV) were measured by MRI and thermodilution (TD) in 15 mice (3 L1, 4 L2, 8 LC). In protocol 2, 23 mice (7 L1, 8 L2, 8 LC) were scanned at 1 month of life and every 4 weeks thereafter. In both protocols, cine-MRI was performed with the use of a 1.5-T clinical system (1.5-mm slices, 195x195 microm in-plane resolution). MRI CO and SV correlated well with TD [COTD (mL/min)=0.94*COMRI+0.72, r=0.84; SVTD( microL)=1. 01*SVMRI-1.07, r=0.94]. Serial MRI studies showed significant increase in LV mass and volumes over time and a significant decrease in ejection fraction in transgenic mice when compared with littermate controls. Compared with lineage 2, lineage 1 showed significantly larger LV mass and volumes and significantly lower ejection fraction. CONCLUSIONS: MRI assessment of cardiac function in mice correlates well with invasive measurements. Serial MRI studies in the TNF-alpha mouse model demonstrate that the rate of progression and severity of LV dysfunction are dependent on the degree of TNF-alpha overexpression.
Animals↗
Sequential molecular abnormalities are involved in the multistage development of squamous cell lung carcinoma.
To understand the molecular pathways involved in the pathogenesis of squamous cell lung carcinoma, we obtained DNA from 94 microdissected foci from 12 archival surgically resected tumors including histologically normal epithelium (n=13), preneoplastic lesions (n=54), carcinoma is situ (CIS) (n=15) and invasive tumors (n=12). We determined loss of heterozygosity (LOH) at 10 chromosomal regions (3p12, 3p14.2, 3p14.1-21.3, 3p21, 3p22-24, 3p25, 5q22, 9p21, 13q14 RB, and 17p13 TP53) frequently deleted in lung cancer, using 31 polymorphic microsatellite markers, including 24 that spanned the entire 3p arm. Our major findings are as follows: (1) Thirty one percent of histologically normal epithelium and 42% of mildly abnormal (hyperplasia/metaplasia) specimens had clones of cells with allelic loss at one or more regions; (2) There was a progressive increase of the overall LOH frequency within clones with increasing severity of histopathological changes; (3) The earliest and most frequent regions of allelic loss occurred at 3p21, 3p22-24, 3p25 and 9p21; (4) The size of the 3p deletions increased with progressive histologic changes; (5) TP53 allelic loss was present in many histologically advanced lesions (dysplasia and CIS); (6) Analyses of 58 normal and non-invasive foci having any molecular abnormality, indicated that 30 probably arose as independent clonal events, while 28 were potentially of the same clonal origin as the corresponding tumor; (7) Nevertheless, when the allelic losses in the 30 clonally independent lesions and their clonally unrelated tumors were compared the same parental allele was lost in 113 of 125 (90%) of comparisons. The mechanism by which this phenomenon (known as allele specific mutations) occurs is unknown; (8) Four patterns of allelic loss in clones were found. Histologically normal or mildly abnormal foci had a negative pattern (no allelic loss) or early pattern of loss while all foci of CIS and invasive tumor had an advanced pattern. However dysplasias demonstrated the entire spectrum of allelic loss patterns, and were the only histologic category having the intermediate pattern. Our findings indicate that multiple, sequentially occurring allele specific molecular changes commence in widely dispersed, apparently clonally independent foci, early in the multistage pathogenesis of squamous cell carcinomas of the lung.
Aged↗
Molecular abnormalities associated with secretory carcinomas of the breast.
Secretory carcinomas (SCAs) represent a unique histological variant of invasive breast carcinomas, occurring predominantly in patients younger than 30 years of age. Data from limited series have shown SCAs to have a favorable prognosis in patients younger than 20 years of age, whereas the clinical course tends to parallel the more common in filtrating ductal carcinomas (IDCs) in patients older than 20 years. There are no reports on the molecular abnormalities associated with this unusual tumor. Microdissected archival formalin-fixed tissue from 10 SCAs collected from 2 institutions were used to determine the frequencies of allelic loss at 13 chromosomal regions with 19 microsatellite markers, using multiplex polymerase chain reaction (PCR)-based techniques. The results of loss of heterozygosity (LOH) and microsatellite alterations (MAs) analyses were compared with 20 cases of IDCs. P53 gene mutation analysis was also performed on the 10 SCAs using single-strand conformation polymorphism (SSCP) analysis, followed by sequencing of abnormal bands. LOH at multiple regions of chromosome 3p were the most common abnormality in both SCAs (55%) and IDCs (50%), followed by LOH at 17q21 (BRCA1 locus), 13q14 (retinoblastoma gene locus), and 8p21-23. No significant differences were seen in the frequencies of LOH at any chromosomal region except for 17p13 (p53 gene locus), where allelic losses were absent in SCAs, but evident in 46% of IDCs (P < .05). The 2 histological entities were similar in the fractional regional loss (FRL) index (0.26 v 0.24), fractional allelic loss (FAL) index (0.23 v 0.27), as well as in the frequency of MAs (0.015 v 0.005), P > .05. P53 gene missense mutation (G:C::A:T) was detected in 1 of 10(10%) SCAs. Based on the considerable similarities in the molecular abnormalities associated with both tumors, the formation of secondary lumina in both the in situ and the invasive components, as well as suggestions from limited series that the clinical behavior in adult patients parallels that of IDCs, SCA most likely reflects a secretory variant of IDCs.
Adult↗
Comparison of features of human lung cancer cell lines and their corresponding tumors.
Although human lung tumor-derived cell lines play an important role in the investigation of lung cancer biology and genetics, there is no comprehensive study comparing the genotypic and phenotypic properties of lung cancer cell lines with those of the individual tumors from which they were derived. We compared a variety of properties of 12 human non-small cell lung carcinoma (NSCLC) cell lines (cultured for a median period of 39 months; range, 12-69) and their corresponding archival tumor tissues. There was, in general, an excellent concordance between the lung tumor cell lines and their corresponding tumor tissues for morphology (100%), the presence of aneuploidy (100%), immunohistochemical expression of HER2/neu (100%) and p53 proteins (100%), loss of heterozygosity at 13 chromosomal regions analyzed (97%) using 37 microsatellite markers, microsatellite alterations (MAs, 75%), TP53 (67%), and K-ras (100%) gene mutations. In addition, there was 100% concordance for the parental allele lost in all 115 comparisons of allelic losses. Some discrepancies were found; more aneuploid subpopulations of cells were detected in the cell lines as well as higher incidences of TP53 mutations (4 of 10 mutations not found in the tumors) and microsatellite alterations (two cell lines with MAs not detected in the tumors). Similar loss of heterozygosity frequencies by chromosomal regions and mean fractional allelic loss index were detected between successfully cultured and 40 uncultured lung tumors (0.45 and 0.49, respectively), indicating that both groups were similar. Our findings indicate that the NSCLC cell lines in the large majority of instances retain the properties of their parental tumors for lengthy culture periods. NSCLC cell lines appear very representative of the lung cancer tumor from which they were derived and thus provide suitable model systems for biomedical studies of this important neoplasm.
Adult↗
Cardiac failure in transgenic mice with myocardial expression of tumor necrosis factor-alpha.
BACKGROUND: Tumor necrosis factor-alpha (TNF-alpha) is a multifunctional cytokine that has been detected in several human cardiac-related conditions, including congestive heart failure and septic cardiomyopathy. In these conditions, the origin of TNF-alpha secretion is, at least in part, cardiac myocytes. METHODS AND RESULTS: To determine the consequences of TNF-alpha production by cardiac myocytes in vivo, we developed transgenic mice in which expression of a murine TNF-alpha coding sequence was driven by the murine alpha-myosin heavy chain promoter. Four transgenic founders developed an identical illness consisting of tachypnea, decreased activity, and hunched posture. In vivo, ECG-gated MRI of symptomatic transgenic mice documented a severe impairment of cardiac function evidenced by biventricular dilatation and depressed ejection fractions. All transgenic mice died prematurely. Pathological examination of affected animals revealed a globular dilated heart, bilateral pleural effusions, myocyte apoptosis, and transmural myocarditis in both the right and left ventricular free walls, septum, and atrial chambers. In all terminally ill animals, there was significant biventricular fibrosis and atrial thrombosis. CONCLUSIONS: This is the first report detailing the effects of tissue-specific production of TNF-alpha by cardiac myocytes in vivo. These findings indicate that production of TNF-alpha by cardiac myocytes is sufficient to cause severe cardiac disease and support a causal role for this cytokine in the pathogenesis of human cardiac disease.
Animals↗
Otitis media, the caregiving environment, and language and cognitive outcomes at 2 years.
OBJECTIVE: To examine the relationship between otitis media with effusion (OME) and associated hearing loss between 6 and 24 months of age and children's language and cognitive development at 2 years of age. STUDY DESIGN: A prospective cohort design in which 86 African-American infants who attended group child-care centers were recruited between 6 and 12 months of age. Between 6 and 24 months, assessments included serial ear examinations using otoscopy and tympanometry, serial hearing tests, two ratings of the childrearing environment at home and in child care, and language and cognitive outcomes at 2 years. RESULTS: Children experienced either unilateral or bilateral OME an average of 63% and reduced hearing sensitivity an average of 44% of the time between 6 and 24 months of age. Although proportion of time with OME or with hearing loss was modestly correlated with measures of language and cognitive skills, these relationships were no longer significant when the ratings of the home and child-care environments were also considered. Children with more OME or hearing loss tended to live in less responsive caregiving environments, and these environments were linked to lower performance in expressive language and vocabulary acquisition at 2 years. CONCLUSIONS: Both OME and hearing loss were more strongly related to the quality of home and child-care environments than to children's language and cognitive development. Study results might be explained either by suggesting that children in less responsive caregiving environments experience conditions that make them more likely to experience OME and/or by suggesting that it may be more difficult for caregivers to be responsive and stimulating with children with more OME.
Black People↗