Preliminary study of a new online and equipment-free vision screening alternative for remote and isolated community.

INTRODUCTION: Vision screening has been initiated to detect potential vision problems, paving referral pathways towards a full eye examination. Time-cost-labour practicality challenges of equipment-based vision screening have lingered for decades. Going for the highest sensitivity and specificity or opting for a pragmatic and affordable vision screening program remains a dilemma in public eye health. We aimed to report the development of a new online and equipment-free vision screening called Eye: Questionnairebased Vision Screening (EyeQVS). We also analysed the visual profile of Orang Bateq resided in a remote locality, using findings from EyeQVS, single test vision screening and full eye examination. MATERIALS AND METHODS: Multi-perspective development strategies were employed in designing EyeQVS. The questionnaire items were constructed using the working backward technique, compiling common vision disorders from the literature and face validation using expert panels. Face validation and usability assessment were performed on EyeQVS. The vision screening was carried out using EyeQVS and single test visual acuity screening method. The full eye examination included visual acuity, refraction, binocular vision and ocular health assessment. The visual profile of indigenous people (Orang Bateq) at Kampung Bengoi and Kampung Atok, Jerantut, Pahang was analysed using EyeQVS, single test visual acuity screening method and full eye examination. RESULTS: The performance of EyeQVS was affirmative in both face validation and usability. About 95% of Orang Bateq failed full eye examination, while 55% failed EyeQVS screening. None of them failed single test vision screening. Binocular disorders and dry eye problems were commonly found in Orang Bateq. EyeQVS unearthed more various vision problems compared to the single test vision screening (visual acuity alone) as a screening tool in a remote location. CONCLUSION: EyeQVS can screen for binocular disorders and dry eyes problem commonly found among indigenous people, which might be missed using a single-test visual acuity screening approach. EyeQVS is a practical alternative for vision screening in places where financial or location hinders eye healthcare access.

Systematic review of hearing loss in dental professionals.

BACKGROUND: Hearing loss leads to increased irritability and disengagement in social activities and conversations, which may impact quality of life. Dental professionals are at risk of developing hearing loss through daily exposure to noise from a wide range of equipment that produces significantly high decibels and noise frequencies. AIMS: The aim of this systematic review was to investigate the risk of hearing loss in dental professionals, including dentists, dental specialists, dental hygienists and dental assistants. METHODS: This review was conducted following the Cochrane Handbook for Systematic Reviews. PubMed, Scopus, Embase, Cochrane, Science Direct, Google Scholar and ProQuest were searched up to March 2023. Seventeen of 416 studies met the inclusion criteria. Quality assessment was performed according to the Newcastle-Ottawa Scale for cohort and case-control studies, and a modified version of this tool for cross-sectional studies. RESULTS: The majority of included studies (82%) found a positive association with hearing loss for dentists and dental specialists, with years of clinical experience identified as a prominent risk factor. Dental hygienists and dental assistants were less commonly reported in the literature. Difference between the left and right ears was found in 71% of studies, with the left ear more affected in both dentists and dental assistants due to proximity to the noise-inducing equipment. CONCLUSIONS: Dental professionals are at risk of hearing loss in their workplace, especially linked to years of clinical experience, which highlights the need for prevention and appropriate ear-protective devices.

Routine chest CT for staging of gastric cancer.

BACKGROUND: International guidelines on clinical staging of gastric cancer recommend the use of chest CT for the detection of pulmonary metastases. This study assessed the clinical value of routine chest CT in the staging of gastric cancer. METHODS: This retrospective study included patients identified from the gastric cancer registry of Chang Gung Memorial Hospital, Linkou, Taiwan. All patients who underwent clinical staging between 2008 and 2014 were included. The pattern, site and number of metastases at initial presentation and after surgery with curative intent were evaluated. Pulmonary metastases were defined as multiple small round pulmonary nodules with a random distribution or of variable size. RESULTS: Some 1669 patients were included, of whom 478 (28·6 per cent) had metastatic disease at clinical presentation. The majority of metastases were to the peritoneum (75·7 per cent of patients) or liver (30·5 per cent), and only 27 patients (5·6 per cent) had pulmonary metastases at presentation, none of which were isolated to the lung. Of these 27 patients, 11 had primary lesions located at the cardia/fundus. In 19 patients the lung metastases were also detected on the staging chest X-ray. After surgery there were 196 cancer recurrences. Some 15 patients (7·6 per cent) had lung metastasis and this was not the only site of metastases in any patient. The prevalence of lung metastasis at presentation of the disease and after surgery was 1·6 and 1·5 per cent respectively. CONCLUSION: This study does not support the routine use of chest CT for staging of gastric cancer as isolated pulmonary metastasis in the absence of other metastatic sites could not be detected.

Effect of co-culturing human primary basic fibroblasts with respiratory syncytial virus-infected 16-HBE cells.

This study investigated the effects induced by co-culturing human primary basic fibroblasts (HPBFs) with 16-human bronchial epithelial cells (16-HBE) infected with respiratory syncytial virus (RSV), in particular the transformation of HPBFs into myofibroblasts and secretion of extracellular matrix proteins. HPBFs were co-cultured with 16-HBE cells infected with RSV and quantitatively analyzed. We constructed models of HPBFs co-cultured with 16-HBE cells that were either uninfected (control group) or infected with RSV (experimental group). Following initiation of co-cultures, HPBFs and supernatants were collected at 24-h intervals up to 120 h. Expression of α-smooth muscle actin (α-SMA) was detected by indirect immunofluorescence and western blotting, while type I collagen (Col I) and fibronectin were analyzed by competitive enzyme-linked immunosorbent assays. After 72 h, α-SMA expression increased in HPBFs cultured with RSV-infected 16-HBE relative to uninfected controls, reaching its highest level at 96 h. Similarly, Col I secretion was also higher in HPBFs co-cultured with RSV-infected 16-HBE relative to uninfected controls; Col I secretion increased with time and reached its highest level at 120 h. HPBFs were transformed into myofibroblasts following co-culture with RSV-infected 16-HBE, which when combined with the observed increase in Col I secretion suggests that airway remodeling would then be promoted.

Interaction of six candidate genes in essential hypertension.

We explored the interaction of 6 candidate genetic mutations in essential hypertension (EH). The mutations AGT M235T, ACE I/D, eNOS Glu298Asp, ET-2 A985G, ANP T2238C, and NPRC A-55C were detected using a genechip microarray in 100 patients with EH and 97 controls from the Han population living in the Yunnan Province of China. Risks of EH were evaluated with respect to a combination of these genotypes. Interactions were analyzed using multifactor dimensionality reduction (MDR). P values were corrected using Bonferroni's adjustment. Results showed that CC genotype frequencies for NPRC A-55C (0.540) in EH were significantly higher than those in controls (0.237, Pc < 0.01; odds ratio (OR) = 3.777; 95% confidence interval (CI) = 2.050-6.960). The OR for NPRC A-55C CC combined with ET-2 A985G GG increased to 4.673 and to 5.529 when the MT genotype of AGT M235T, the EE genotype of eNOS Glu298Asp, the GG genotype of ET-2 A985G, and the CC genotype of NPRC A-55C were combined. MDR showed that ET-2/NPRC is the best model (OR = 4.002; 95%CI = 2.1597-7.4159). The CC genotype for NPRC A-55C and the G allele for ET-2 A985G were associated with susceptibility to EH. Although the contributions of the candidate genes differ, they may have cooperative effects on conferring risk for EH. Moreover, potential gene-gene interactions were found between ET-2 A985G and NPRC A-55C in EH.

Parity-preserving and magnetic field-resilient superconductivity in InSb nanowires with Sn shells.

Improving materials used to make qubits is crucial to further progress in quantum information processing. Of particular interest are semiconductor-superconductor heterostructures that are expected to form the basis of topological quantum computing. We grew semiconductor indium antimonide nanowires that were coated with shells of tin of uniform thickness. No interdiffusion was observed at the interface between Sn and InSb. Tunnel junctions were prepared by in situ shadowing. Despite the lack of lattice matching between Sn and InSb, a 15-nanometer-thick shell of tin was found to induce a hard superconducting gap, with superconductivity persisting in magnetic field up to 4 teslas. A small island of Sn-InSb exhibits the two-electron charging effect. These findings suggest a less restrictive approach to fabricating superconducting and topological quantum circuits.

[Multicenter study of human adenovirus infection in pediatric community-acquired pneumonia in China].

Objective: To investigate the predominant genotypes and epidemiological characteristics of human adenovirus (HAdV) in pediatric community-acquired pneumonia (CAP) in China. Methods: This was a repeated cross sectional study. Between November 2014 and November 2016, nasopharyngeal aspirates (NPAs) or throat swabs from each hospitalized pediatric patients diagnosed as CAP in 12 hospitals in Northern and Southern China were collected. Respiratory specimens were screened for 18 respiratory viruses including HAdV by using Luminex xTAG RVP Fast V2 multiplex Assay. Typing of HAdV and analysis for the epidemiological characteristic of HAdV were performed. Results: (1) A total of 2 723 hospitalized pediatric patients with CAP were enrolled in this study and 156 (5.7%, 156/2 723) respiratory specimens were positive for HAdV, and 74 (6.6%, 74/1 128) and 82 (5.1%, 82/1 595) were in Northern and Southern China, respectively. There was no significant difference in the positive detection rate between the Northern and Southern China. (2) In Northern China, the HAdV positive rate of children at the age of <6 months, 6 months-<1 years, 1-<3 years, 3-<5 years and ≥5 years was 5.9%(6/101), 6.7%(7/104), 10.3%(34/331), 4.1%(11/266) and 4.9%(16/326), respectively, and the incidence of HAdV infection peaked in children aged 1-3 years (χ(2)=11.511, P=0.021). While in Southern China the HAdV positive rate of children at the age of <6 months, 6 months-<1 years, 1-<3 years, 3-<5 years and ≥5 years was 2.2% (7/312), 4.6% (12/259), 6.3% (31/494), 7.3% (18/245) and 4.9%(14/285), respectively. There was no significant difference in the positive detection rate among age groups. (3) In 2015, the highest detection rate of HAdV in northern China was 12.5% (25/200) in winter, and in Southern China was 6.7% (35/525) in spring and 5.3% (19/357) in summer. (4) In 108 cases of HAdV positive specimens typing was done and 80 in cases classification was successfully performed.Totally 7 genotypes of HAdV, including HAdV-3 (n=32), HAdV-7 (n=9), HAdV-1 (n=12), HAdV-2 (n=15), HAdV-5 (n=10), HAdV-6 (n=1) and HAdV-4 (n=1), were detected. The predominant HAdV genotypes were HAdV-3 (30.8%, 8/26) and HAdV-7 (26.9%, 7/26) in Northern China, while HAdV-3 (44.4%, 24/54) and HAdV-2 (22.2%, 12/54) were the most prevalent genotypes in Southern China. Conclusions: HAdV is an important viral pathogen in pediatric CAP. The predominant HAdV genotypes and peak seasons of HAdV infections were different between Northern and Southern China. The predominant HAdV genotypes were HAdV-3 and HAdV-7 in Northern China, while HAdV-3 and HAdV-2 in Southern China. The peak season of HAdV infections was winter in Northern China. However, HAdV infections are more common in spring and summer in Southern China.

Data from subjects receiving intrathecal laronidase for cervical spinal stenosis due to mucopolysaccharidosis type I.

Five subjects with mucopolysaccharidosis type I and symptomatic cervical spinal stenosis received intrathecal laronidase in a 4-month pilot study and/or a 12-month extension study [1]. Clinical descriptions of study subjects, nonserious adverse events, individual data tables, and scoring system methods are provided. There were ten nonserious adverse events that occurred in more than one study subject. Somatosensory evoked potentials were absent in two subjects and normal in two subjects, limiting their utility as an endpoint. There were no significant changes in magnetic resonance imaging of cervical spinal cord or brain, pulmonary function tests, or cerebrospinal fluid opening pressure. These data are presented along with the scoring methods used in evaluation of the study subjects.

Efficacy of media enriched with nonlactate-generating substrate for organ preservation: in vitro and clinical studies using the cornea model.

BACKGROUND: Using a rabbit cornea model, our recent study demonstrated that Chen Medium (CM), an isotonic media enriched with nonlactate-generating high-energy substrates, is very effective for organ preservation. In the present study, the efficacy of CM is further evaluated with human corneas METHODS: The effectiveness of CM and Optisol for preserving the endothelial integrity of human corneas in vitro was evaluated by scanning electron microscopy. Clinical efficacy was evaluated in a total of 83 patients: 10 patients with keratoconus grafted randomly with either CM- or Optisol-stored cornea of the same donor, and 73 patients with various conditions grafted with CM-stored corneas. After surgery, visual acuity and quality of the graft were monitored for up to 4.6 years. RESULTS: The scanning electron microscopic study revealed that after 11-day storage at 4 degrees C, the CM-stored cornea had only marginal disruptive changes, 9.4+/-1.1%, in endothelial cells, as opposed to 42.4+/-4.6% of the Optisol-stored cornea. All 78 CM-stored corneas, including 67 with 12.2- to 17.7-hr death-to-storage time, 3-7.6 days of storage time, and initial marginal quality before storage, were successfully transplanted. These grafts were thin and clear, with an excellent epithelial integrity and without significant changes in endothelial cell density. Five Optisol-stored corneas were also successfully grafted; one of them, however, was edematous for about 4 weeks, and all the grafts were slightly thicker with substantial endothelial cell loss. CONCLUSION: Using a cornea model, present and recent studies show that CM is very effective for preserving tissue viability and endothelial integrity. Previous study revealed that CM-stored tissues maintained high levels of ATP and metabolic function, with suppression of lactate formation and accumulation. Thus, these findings support the concept that preservation of tissue viability is closely associated with the ability of the tissues to retain metabolic activity, to generate ATP efficiently, and to prevent acidosis effectively during storage.

Localization of a novel gene for nonsyndromic hearing loss (DFNB17) to chromosome region 7q31.

Autosomal recessive nonsyndromic hearing loss (ARNSHL) is the most common form of hereditary hearing impairment (HHI). To date, 16 different loci have been reported, making ARNSHL an extremely heterogeneous disorder. One of these loci, DFNB4, was mapped to a 5-cM interval of 7q31 in a large Middle-Eastern Druze family. This interval also includes the gene for Pendred syndrome. We report on three new families with HHI from the Madras region of southern India that demonstrate linkage to 7q. Their pedigrees are compatible with autosomal recessive inheritance. Furthermore, the largest family identifies a novel locus (DFNB17) telomeric to the DFNB4 and Pendred intervals. A 3-cM region of homozygosity by descent between markers D7S486 and D7S2529 is present in all affected individuals in this family and generates a multipoint LOD score of 4.24. The two other families map to the previously reported DFNB4 region but have insufficient power to attain significant LOD scores. However, mutations in the Pendred syndrome gene are present in one of these families.

Early postoperative angiographic assessment of radial grafts used for coronary artery bypass grafting.

UNLABELLED: Despite a revival of interest in using the radial artery as an alternative conduit for myocardial revascularization, little angiographic documentation of early postoperative results has been presented, particularly in North America. Accordingly, 60 of 150 patients who underwent coronary artery bypass with radial arteries from November 1993 to July 1995 have had postoperative cardiac catheterization at our institution. The patency rate of the radial artery grafts was 95.7% (90 of 94 grafts patent) with an average internal diameter of 2.51 mm. Four radial artery grafts showed diffuse narrowing. The patency rate of the internal thoracic artery grafts was 100% with an average internal diameter of 2.25 mm. Three of 62 grafts demonstrated diffuse narrowing. Two of 24 (7.7%) saphenous vein grafts were occluded; the average internal diameter was 3.23 mm. The internal thoracic artery, the radial artery, and saphenous vein grafts were, respectively, 7.5%, 19.5%, and 53.3% larger than the anastomosed native coronary arteries. Graft-dependent flow was found in 81.1% of the radial artery grafts. CONCLUSION: The results of this study demonstrate that the short-term patency rate of radial artery grafts is excellent.

The integrin-mediated cyclic strain-induced signaling pathway in vascular endothelial cells.

The irregular distribution of plaque in the vasculature results from the interaction of local hemodynamic forces with the vessel wall. One well-characterized force is cyclic circumferential strain, the repetitive pulsatile pressure distention on the arterial wall. This review summarizes current research, which has aimed to elicit the signal transduction pathway by which cyclic strain elicits functional and structural responses in endothelial cells; specifically, it summarizes the signaling pathway that begins with the reorganization of integrins. One method by which these extracellular matrix receptors affect signal transduction is through their ability to initiate the process of phosphorylation on tyrosine residues of cytoplasmic protein kinases, including focal adhesion kinase. The strain-induced pathway appears to also involve ras and the mitogen-activated protein kinase family of enzymes, and preliminary data suggests a role for src as well. Ultimately, it is the regulation of gene expression through the modulation of transcription factors that allows endothelial cells to respond to changes in local hemodynamics.

Cyclic strain activates the pro-survival Akt protein kinase in bovine aortic smooth muscle cells.

BACKGROUND: Pulsatile pressure induced by the beating heart causes cyclic strain on arterial endothelial cells and smooth muscle cells (SMCs). This study examined whether Akt, a serine/threonine protein kinase known to promote cell survival by inhibiting apoptosis, is activated by cyclic strain in bovine aortic SMCs. METHODS: Bovine aortic SMCs were cultured on flexible-bottomed membranes and then serum-starved for 24 to 36 hours. The cells were then exposed to 150-mm Hg repetitive deformations, which created an average of 10% strain on the monolayer SMCs at a frequency of 60 cycles/minute for 0 (negative control) and 30 minutes. Platelet-derived growth factor (PDGF)--stimulated SMCs were used as positive controls. Phosphorylation of Akt was determined by means of Western blot analysis. An apoptosis assay (TUNEL) was also performed on SMCs exposed to cyclic strain. RESULTS: Akt phosphorylation was significantly increased over that of the negative control after 30 minutes of cyclic strain and in the PDGF group. Cyclic strain did not increase the prevalence of apoptosis in SMCs over the control. CONCLUSIONS: Cyclic strain activated the pro-survival Akt kinase. The pro-survival function was supported by the fact that cyclic strain did not increase apoptosis in bovine aortic SMCs. This experiment suggests that cyclic strain may induce arterial wall thickening by tipping the balance toward arterial SMC proliferation through the inhibition of apoptosis.

Labor induction with intravaginal misoprostol in term premature rupture of membranes: a randomized study.

OBJECTIVE: To evaluate the safety and clinical effectiveness of intravaginal misoprostol, a synthetic prostaglandin E1 analogue, for labor induction in gravidas with premature rupture of membranes (PROM) at term. METHODS: One hundred forty-one pregnant women with term PROM were assigned randomly to one of two induction groups: 1) intravaginal misoprostol or 2) intravenous oxytocin by continuous infusion. RESULTS: Seventy subjects were allocated to the misoprostol group and 71 to the oxytocin group. The mean (+/- standard deviation) interval from induction to delivery was significantly shorter in the misoprostol group (416 +/- 276 compared with 539 +/- 372 minutes; P = .04). In 85.7% of patients in the misoprostol group, only one dose was required. Intrapartum complication rates, mode of delivery, and neonatal or maternal adverse event rates were similar in the two treatment groups. Uterine tachysystole occurred more frequently with misoprostol than with oxytocin (28.6% compared with 14.0%; P < .04). CONCLUSION: Intravaginal administration of misoprostol induces labor safely and effectively in patients with PROM at term.

Incidence of vocal fold paralysis in infants undergoing ligation of patent ductus arteriosus.

BACKGROUND: Left-sided, iatrogenic vocal fold paralysis (IVFP) secondary to recurrent laryngeal nerve injury is a potential complication of ligation of patent ductus arteriosus (PDA). This study investigates specific risk factors associated with IVFP. METHODS: A retrospective chart review was performed for all infants 12 months of age or younger who underwent operative PDA closure at the University of Iowa from January 1, 1991, to January 1, 1994. RESULTS: Six cases of IVFP were diagnosed in 68 infants who underwent PDA ligation using clips (52.9%), suture ligatures (41.2%) or both (5.9%). Compared with infants without postoperative IVFP, infants with IVFP were smaller at birth (0.9 versus 2.3 kg; p < 0.001) and more premature (gestational age, 26.3 versus 33.8 weeks; p < 0.001), and were smaller (1.1 versus 3.4 kg; p < 0.001) and younger (31.9 versus 88.4 days; p < 0.001) at operation. Weight gain from birth to operation was significant only in infants without postoperative IVFP (p < 0.05). Although the overall incidence of IVFP in all infants undergoing PDA closure was 8.8%, five of the six cases (83.3%) of IVFP occurred in extremely low birth weight infants, ie, those weighing 1 kg or less at birth. Among the cohort of extremely low birth weight babies undergoing operation, the incidence of IVFP was 22.7%. Iatrogenic vocal fold paralysis was associated only with the use of surgical clips; however, because clips were used in 90.9% of the premature infants requiring PDA ligation, it was not possible to establish whether suture ligature is a safer technique. CONCLUSIONS: This study demonstrates that the single major risk factor for IVFP after ligation of PDA is birth weight less than 1 kg.

Laryngeal cancer cost analysis: association of case-mix and treatment characteristics with medical charges.

OBJECTIVES: To examine the relationship of various pretreatment case-mix characteristics and treatment modalities with medical charges incurred during diagnosis, treatment, and 2-year follow-up for patients with laryngeal cancer. DESIGN: Retrospective chart review and billing record analysis. METHODS: The charts and billing records of patients diagnosed with laryngeal cancer at the University of Iowa Hospitals and Clinics (UIHC) between January 1, 1991 and December 31, 1994 were reviewed. The independent variables included various pretreatment patient-mix and tumor characteristics (age, AJCC TNM clinical stage, smoking history, ASA class, and comorbidity as defined by Kaplan-Feinstein grade) as well as type of treatment. The dependent variables included total physician, office, and university hospital-based charges incurred during the pretreatment evaluation and 0- to 3-, 3- to 12, and 12- to 24-month billing periods after the initiation of cancer-directed therapy. Total 1-year and 2-year charges were also evaluated. Univariate and multivariate analyses were used to investigate the relationships between dependent and independent variables and to develop models predictive of management charges during the individual and total billing periods. RESULTS: Pretreatment charges showed no significant associations (P < .05) with any of the independent variables. Multiple regression analyses indicated that comorbidity, stage, and initial treatment modality were significant variables in one or more of the models predicting charges incurred during the 0- to 3-month, 3- to 12-month, total 1-year, and total 2-year billing periods. The models yielded R2 values for the total 1- and 2-year billing periods of 0.5246 and 0.5055, respectively. CONCLUSIONS: This work supports continued study of measures that may result in earlier detection of laryngeal cancer as a potential means of reducing management charges. These results also indicate that a more accurate method of stratifying the disease severity of laryngeal cancer patients for reimbursement purposes would include measurements of the severity of the index disease as well as comorbid diseases.

Presymptomatic diagnosis of nonsyndromic hearing loss by genotyping.

BACKGROUND: Nonsyndromic hearing loss (NSHL) is the most common type of hereditary hearing impairment (HHI). It is genetically heterogeneous, and although the exact number of genes is not known, 38 loci have been identified. By cloning the relevant genes and studying the function of the encoded proteins at the molecular level, it may be possible to impact the habitation of persons at risk for HHI. Currently, for select families, presymptomatic diagnosis of NSHL by genotyping is possible. OBJECTIVE: To provide presymptomatic diagnosis of HHI to individuals in select families who have participated in linkage studies. DESIGN: In 2 large families with autosomal dominant HHI, genes for NSHL were mapped to chromosomes 6 (DFNA10) and 19 (DFNA4). In each family, the phenotype is one of progressive sensorineural hearing loss that begins in the individual's mid-30s and progresses to a severe-to-profound loss requiring amplification. Presymptomatic diagnosis was requested by, and provided to, 19 at-risk persons in these kindreds. RESULTS: By reconstructing haplotypes through the use of short tandem repeat polymorphisms tightly linked to the disease gene, risk calculations and genetic counseling were provided to these persons. CONCLUSIONS: By simple Mendelian genetics, the risk of inheriting a fully penetrant autosomal dominant NSHL gene from a single affected parent is 50% for each offspring. However, by reconstructing haplotypes in families in which an HHI gene has been localized, this risk can be changed substantially.

MYO1F as a candidate gene for nonsyndromic deafness, DFNB15.

BACKGROUND: Earlier studies have mapped the autosomal recessive nonsyndromic deafness locus, DFNB15, to chromosomes 3q21.3-q25.2 and 19p13.3-13.1, identifying one of these chromosomal regions (or possibly both) as the site of a deafness-causing gene. Mutations in unconventional myosins cause deafness in mice and humans. One unconventional myosin, myosin 1F (MYO1F), is expressed in the cochlea and maps to chromosome 19p13.3-13.2. OBJECTIVE: To evaluate MYO1F as a candidate gene for deafness at the DFNB15 locus by determining its genomic structure and screening each exon for deafness-causing mutations to identify possible allele variants of MYO1F segregating in the DFNB15 family. METHODS: We used radiation hybrid mapping to localize MYO1F on chromosome arm 19p. We next determined its genomic structure using multiple long-range polymerase chain reaction experiments. Using these data, we completed mutation screening using single-stranded conformational polymorphism analysis and direct sequencing of affected and nonaffected persons in the original DFNB15 family. RESULTS: Radiation hybrid mapping placed MYO1F in the DFNB15 interval, establishing it as a positional candidate gene. Its genomic structure consists of 24 coding exons. No mutations or genomic rearrangements were found in the original DFNB15 family, making it unlikely that MYO1F is the disease-causing gene in this kindred. CONCLUSIONS: Although we did not find MYO1F allele variants in one family with autosomal recessive nonsyndromic hearing loss, the gene remains an excellent candidate for hereditary hearing impairment. Given its wide tissue expression, MYO1F might cause syndromic deafness.