A mutation in OTOF, encoding otoferlin, a FER-1-like protein, causes DFNB9, a nonsyndromic form of deafness.

Using a candidate gene approach, we identified a novel human gene, OTOF, underlying an autosomal recessive, nonsyndromic prelingual deafness, DFNB9. The same nonsense mutation was detected in four unrelated affected families of Lebanese origin. OTOF is the second member of a mammalian gene family related to Caenorhabditis elegans fer-1. It encodes a predicted cytosolic protein (of 1,230 aa) with three C2 domains and a single carboxy-terminal transmembrane domain. The sequence homologies and predicted structure of otoferlin, the protein encoded by OTOF, suggest its involvement in vesicle membrane fusion. In the inner ear, the expression of the orthologous mouse gene, mainly in the sensory hair cells, indicates that such a role could apply to synaptic vesicles.

Neurodevelopmental abnormalities associated with severe congenital neutropenia due to the R86X mutation in the HAX1 gene.

OBJECTIVE: Severe congenital neutropenia (SCN), also known as Kostmann syndrome (SCN3, OMIM 610738), includes a variety of haematological disorders caused by different genetic abnormalities. Mutations in ELA2 are most often the cause in autosomal dominant or sporadic forms. Recently, mutations in HAX1 have been identified as the cause of some autosomal recessive forms of SCN, including those present in the original pedigree first reported by Kostmann. We sought to determine the relationship between HAX1 gene mutations and the clinical characteristics of Japanese cases of SCN. METHODS: The genes implicated in SCN (ELA2, HAX1, Gfi-1, WAS, and P14) were analysed in 18 Japanese patients with SCN. The clinical features of these patients were obtained from medical records. Immunoblotting of HAX1 was performed on cell extracts from peripheral blood leucocytes from patients and/or their parents. RESULTS: We found five patients with HAX1 deficiency and 11 patients with mutations in the ELA2 gene. In HAX1 deficiency, a homozygous single base pair substitution (256C>T), which causes the nonsense change R86X, was identified in three affected individuals. Two sibling patients showed a compound heterozygous mutation consisting of a single base pair substitution (256C>T) and a 59 bp deletion at nucleotides 376-434. There was no detectable phenotype in any heterozygous carrier. All patients with HAX1 deficiency had experienced developmental delay. Three patients carrying R86X also suffered from epileptic seizures. In contrast, no SCN patient with heterozygous mutations in the ELA2 gene suffered from any neurodevelopmental abnormality. CONCLUSIONS: These findings suggest that the R86X mutation in the HAX1 gene is an abnormality in Japanese SCN patients with HAX1 deficiency and may lead to neurodevelopmental abnormalities and severe myelopoietic defects.

Molecular cloning of rat uncoupling protein 2 cDNA and its expression in genetically obese Zucker fatty (fa/fa) rats.

We isolated rat UCP2 cDNA, which has been proposed to play an important role in mammalian thermogenesis and body weight regulation. The nucleotide sequence of the cDNA revealed that the rat UCP2 protein is composed of 309 amino acid residues, and is 99% and 95% identical to the mouse and human proteins, respectively. The molecular weight of rat UCP2, calculated from the predicted amino acid sequence, was 33,369, and the UCP2 protein of this size was detected when the cDNA was expressed in vitro. Northern blot analysis revealed that the corresponding mRNA is approximately 1.7 kb in size, and is expressed in a variety of rat organs, with predominant expression in the heart, lung and spleen. UCP2 mRNA levels in the heart, liver, muscle and epididymal adipose tissue of Zucker fatty (fa/fa) rats were comparable to those in the lean littermates, while ob mRNA level markedly increased in the epididymal adipose tissue of Zucker (fa/fa) rats.

Rapid electrical stimulation of contraction reduces the density of beta-adrenergic receptors and responsiveness of cultured neonatal rat cardiomyocytes. Possible involvement of microtubule disassembly secondary to mechanical stress.

BACKGROUND: Although tachycardia is commonly present in patients with congestive heart failure, its role in the development of congestive heart failure remains unclear. We studied the effect of rapid electrical stimulation of contraction on beta-adrenergic receptor (beta-AR) signal pathway in cultured cardiomyocytes of neonatal rats. METHODS AND RESULTS: Contraction of cardiomyocytes was induced by electrical stimulation at 50 V with twice the threshold pulse width. beta-ARs were identified by [(3)H]CGP-12177 and [(3)H]dihydroalprenolol. Electrical stimulation reduced cell-surface but not total beta-AR density; the effect was dependent on pacing frequency (a reduction of 11%, 28%, and 18% in cells paced at 2.5, 3. 0, and 3.3 Hz, respectively). This reduction was apparent at 3 hours, in contrast to reduced beta-AR density after exposure to isoproterenol (ISP) for 1 hour. The fraction and inhibition constant of beta-AR binding agonist with high affinity were not affected by rapid electrical stimulation. In cardiomyocytes paced at 3.0 Hz for 24 hours, the response to ISP decreased compared with unpaced cells, 142% versus 204% of baseline with 1 micromol/L ISP, whereas the responses to forskolin or acetylcholine were not different. Treatment of cardiomyocytes with 2,3-butanedione monoxime (10 mmol/L) or taxol (10 micromol/L) inhibited the rapid pacing-induced reduction in beta-AR density. CONCLUSIONS: Our results suggest that contractile activity is involved in regulation of cardiac function by modulating the beta-AR system independently of hemodynamic and neurohormonal factors. This may help to elucidate the role of mechanical stress in the development of heart failure.

IL-4 and IL-13: their pathological roles in allergic diseases and their potential in developing new therapies.

The incidence of allergic diseases has dramatically increased in recent decades, and it is socially and medically important to establish more useful strategies to overcome allergic disorders. Various kinds of drugs are utilized for allergic patients; however, some cases are unresponsive to these drugs and in others there are undesired adverse effects. On the other hand, a substantial body of evidence has accumulated pointing to the pivotal role of Th2-cytokines, interleukin (IL)-4, and IL-13, in the pathogenesis of bronchial asthma. The evidence is categorized as (1) expression of these cytokines in the bronchial lesions, (2) genetic association of the signaling molecules of these cytokines, (3) analyses of mouse models. In addition, the molecular mechanism of the signal transduction of these cytokines has also been well characterized. Based on such information, IL-4 and IL-13 have emerged as promising means of improving allergic states, and several IL-4/IL-13 antagonists have been developed, among which soluble IL-4 receptor is now in human trials. Identifying the structure of the IL-13 variant and of the IL-4/IL-13-inducing genes would be of great use. It is expected that in the near future, several drugs will emerge based on these strategies, which will give us wider choice in treating patients, depending on the pathogenesis of the diseases.

Extensive polymorphism of a (CA)n microsatellite located in the HLA-DQA1/DQB1 class II region.

A highly polymorphic (CA)n microsatellite marker (DQCAR), located between the DQA1 and the DQB1 genes, was characterized in four ethnic groups. Based on length polymorphism, 12 alleles could be defined. The marker is located 1- to 2-kb telomeric to the DQB1 gene and 10 kb centromeric to the DQA1 gene and was shown to be in tight linkage disequilibrium with HLA-DQ. Analysis of the linkage disequilibrium pattern revealed little additional diversity in DQ1-associated haplotypes. Almost all DQ1 subjects examined were DQCAR 103 or DQCAR 107 (13 and 15 CA repeats, respectively). In contrast, significant haplotypic diversity was observed for most DQ2-, DQ3-, and DQ4-associated haplotypes. These haplotypes often had longer allele sizes (DQCAR > 111, more than 17 CA repeats) and more DQCAR alleles per haplotype. These haplotypes also carried DQCAR alleles of different sizes, even though they bore the same DQA1 and DQB1 alleles, and sometimes the same DRB1 allele as well. These results indicate that DQCAR could be a useful marker to better define disease associations with HLA. Our results are also consistent with the hypothesis that CAR alleles with higher numbers of repeats have higher mutation rates and that recombination within the HLA-DR/DQ region is haplotype dependent.

Novel mutation of the DAX1 gene in a patient with X-linked adrenal hypoplasia congenita and hypogonadotropic hypogonadism.

X-linked adrenal hypoplasia congenita (AHC) is characterized by primary adrenal insufficiency and is frequently associated with hypogonadotropic hypogonadism (HHG). Mutations of the DAX1 gene have been reported in patients with AHC and HHG. We found a novel DAX1 mutation in our patient. Sequence analysis of the patient's DAX1 demonstrated a 1-bp (G) deletion at codon 49 in exon 1. The mutation shifts the reading frame, resulting in completely different amino acid sequences from codon 49 to the premature stop codon at 84. The G was present at this position in the sequences of the father and 2 younger brothers. Direct sequence and single-strand conformation polymorphism analyses of polymerase chain reaction fragments revealed that the mutation at codon 49 was heterozygously present in the mother's DAX1 gene. The codon 84 is located in the first half of the DNA binding domain, and the mutation site is closer to the N-terminus than those in previously reported cases. The onset of adrenal insufficiency in the neonatal period as seen in our patient has also been reported in other patients with different DAX1 mutations, especially in a patient with DAX1 protein lacking 11 amino acids at the C-terminus. Therefore, it is less likely that position of termination codons correlate to clinical manifestations.

Application of a type-specific enzyme-linked immunosorbent assay for equine herpesvirus types 1 and 4 (EHV-1 and -4) to horse populations inoculated with inactivated EHV-1 vaccine.

A type-specific enzyme-linked immunosorbent assay (ELISA) using equine herpesvirus types 1 (EHV-1) and 4 (EHV-4) glycoprotein G was applied for sero-epizootiology of EHV infections in Japan. Recently, an inactivated EHV-1 vaccine has been administered to racehorses for prevention of upper respiratory disease. To examine the effect of the vaccination on the result of the ELISA, 6 horses were experimentally inoculated three times intramuscularly or intranasally with inactivated EHV-1 vaccine. Sera collected from these horses were used to the type-specific ELISA and complement-fixation (CF) test. Although the CF test detected a significant increase of antibody elicited by vaccination, the ELISA did not detect any antibody response. Next, sera collected from thirty-eight horses, which were intramuscularly inoculated with inactivated EHV-1 twice at an interval of four weeks, were used in the ELISA and CF test. The results also indicated that CF titers increased by vaccine inoculation, but ELISA titers did not. To examine epizootiology of EHVs serologically in racehorse populations at two Training Centers of the Japan Racing Association, the type-specific ELISA and CF test were carried out using paired sera collected from racehorses before and after the winter season. The results showed that the ELISA could distinguish EHV-1 and EHV-4 infections in vaccinated horses serologically. In conclusion, the type-specific ELISA is considered to be useful for sero-diagnosis and sero-epizootiological research on EHV-1 and EHV-4 infections not only in unvaccinated horses, but also in vaccinated horses in Japan.

Diagnosis and sero-epizootiology of equine herpesvirus type 1 and type 4 infections in Japan using a type-specific ELISA.

Recently, a type-specific ELISA using equine herpesvirus type 1 (EHV-1) and type 4 (EHV-4) glycoprotein Gs (gGs) was developed by Crabb and Studdert [1993]. To investigate the dissemination of EHV-1 and -4 among horses in Japan, we applied their ELISA as suitable for discriminating between EHV-1 and -4 infections serologically. Type-specificity of the ELISA was confirmed by using paired sera of infected horses with either EHV-1 or -4. Application of the ELISA to sera collected before and after the winter season of 1995-1996 from 80 racehorses revealed that 30 horses showed significant antibody responses against EHV-1 and 9 against EHV-4, respectively. The results indicated that this ELISA using paired sera is useful for a diagnosis and an epizootiological study on EHV-1 and -4 infections.

[Response uncertainty on rule learning by observation: effects of pre-experience on observational learning].

The present study was conducted to examine the hypothesis that children's feelings of uncertainty would mediate between pre-experience and rule acquisition in observational learning. After received a pretest, subjects were requested to estimate their response uncertainty concerning a task used in the pretest. Then they observed a model responding to a series of pictures each of which depicting one of four directions. The model's responses were governed by a rule consisted of two dimensions: the progression and the direction. After observing the demonstration, subjects received two post-tests which differed in the order of stimulus presentation and in terms of the reinforcement. Subjects enhancing their feelings of uncertainty in the pretest phase acquired a rule which contained a dimension of the progression, while subjects who did not enhance them acquired a rule used by the model. These findings were interpreted as generally supporting the hypothesis of response uncertainty as a mediator of rule learning.

Two cases of feline malignant craniopharyngioma.

Tumors at the cranial base in 2 cats (a 9 1/2-year-old, castrated male Chinchilla and a 7-year-old, castrated male American Shorthair) were diagnosed as malignant craniopharyngioma. The tumor lesion was histopathologically divided into four parts: 1) a small acinus part, in which relatively large cells with a pale cytoplasm composed small acini; 2) a duct part, in which small cuboidal cells composed ducts; 3) a cyst part, in which there were large cysts lined with flat cells; and 4) a pavement part, in which large multi-angular-shaped cells proliferated in a pavement pattern. The epithelial cells of some parts were positive for keratin by immunohistochemistry. Histopathologic findings of the present feline cases were identical to those of malignant craniopharyngioma in other animal species.

Effect of three ophthalmic solutions on chemical conjunctivitis in the neonate.

In an attempt to reduce chemical conjunctivitis after silver nitrate prophylaxis, three different ophthalmic solutions (sodium chloride, sterile water, and a boric acid-sodium borate solution) were used to irrigate the eyes immediately after prophylaxis in 450 neonates. Sterile water significantly reduced (P less than .02) the prevalence of chemical conjunctivitis when compared to the conventional sodium chloride rinse. A significantly greater prevalence of chemical irritation in low-birth-weight infants was also noted (P less than .02).

Physical map of the region surrounding the OTOFERLIN locus on chromosome 2p22-p23.

The autosomal recessive form of nonsyndromic deafness DFNB9 has been mapped to a 2-cM region on chromosome 2p22-p23, and the responsible gene, OTOF, has been recently identified by positional cloning combined with a candidate gene approach. In the course of this gene cloning, we established a contig of yeast artificial chromosomes, bacterial artificial chromosomes, and P1 phage artificial chromosomes delimited by polymorphic markers D2S2170 and D2S170, i.e. , extending over approximately 3500 kb. Sixty expressed sequence tags or genes and 14 sequence-tagged sites, 11 of which are polymorphic, were mapped to this contig and assigned to 21 chromosomal intervals.

Synthesis and lectin recognition of polystyrene core-glycopolymer corona nanospheres.

Polymeric nanospheres with a polystyrene core and a glucosyloxyethyl methacrylate (GEMA) oligomer corona were synthesized by the free radical coplymerization of styrene (M(1)) plus a GEMA macromonomer (M(2)) at various molar ratios (M(1)/M(2) = 50-150) in the presence of AIBN (1 mol % to the total monomer) in an ethanol/water (3/2, v/v) solvent. The size of the nanospheres was controlled from 300 to 620 nm by altering the monomer ratio. The size distributions were significantly narrow. The amount of glucose conjugated per unit surface area of the nanosphere, which was analyzed by the anthron-sulfuric acid method, was 1.01-2.28 microg cm(-1), which increased with an increase in size. The transmittance of a solution of dispersed nanospheres (the corresponding glucose concentration was 73 microM) increased by the addition of the glucose-binding protein concanavalin A (Con A) (1-50 microM), indicating that the nanospheres were being precipitated by the cross-linking of ConA. An enzyme-linked lectin assay (ELLA) revealed that Con A bound to the glucose on the nanospheres 250-700-fold more than to monomeric glucose. The binding activity to the nanospheres was less than that to a GEMA oligomer, and decreased with an increase in the amount of GEMA oligomer grafted onto the nanosphere, possibly because of steric hindrance of the lectin binding to the glucose on the nanospheres. The polystyrene core-glycopolymer corona nanosphere is a useful material for studying sugar-biomolecule recognition.