Structure-activity relationship of polypyridyl ruthenium(II) complexes as DNA intercalators, DNA photocleavage reagents, and DNA topoisomerase and RNA polymerase inhibitors.

To investigate the relationship between the molecular structure and biological activity of polypyridyl Ru(II) complexes, such as DNA binding, photocleavage ability, and DNA topoisomerase and RNA polymerase inhibition, six new [Ru(bpy)(2)(dppz)](2+) (bpy=2,2'-bipyridine; dppz=dipyrido[3,2-a:2,',3'-c]phenazine) analogs have been synthesized and characterized by means of (1)H-NMR spectroscopy, mass spectrometry, and elemental analysis. Interestingly, the biological properties of these complexes have been identified to be quite different via a series of experimental methods, such as spectral titration, DNA thermal denaturation, viscosity, and gel electrophoresis. To explain the experimental regularity and reveal the underlying mechanism of biological activity, the properties of energy levels and population of frontier molecular orbitals and excited-state transitions of these complexes have been studied by density-functional theory (DFT) and time-depended DFT (TDDFT) calculations. The results suggest that DNA intercalative ligands with better planarity, greater hydrophobicity, and less steric hindrance are beneficial to the DNA intercalation and enzymatic inhibition of their complexes.

[Visual evoked potentials in adults with migrainous vertigo].

OBJECTIVE: To investigate the visual evoked potentials in adults with migrainous vertigo (MV). METHODS: Totally 113 patients with MV were enrolled from vertigo clinic. Patients received necessary laboratory examinations as well as pattern visual evoked potential (PVEP) testing. RESULTS: Definite MV accounted for 46.9% (53/113) and probable MV accounted for 53.1% (60/113). Among 74 patients who received PVEP, the results were normal in 35 patients (47.3%) and abnormal in 39 patients (52.7%). The abnormal manifestations included lowered N75-P100 amplitude, elongated latency of P100, and lowered N75-P100 amplitude combined with delayed latency of P100. Seven patients with MV had unilateral lowered N75-P100 amplitude and 4 had bilateral abnormal amplitude. Nine patients had unilateral delayed latency of P100 and 11 had bilateral abnormal latency. Four patients had unilateral and 4 had bilateral abnormal N75-P100 amplitude and latency of P100. CONCLUSIONS: MV patients usually have abnormal PVEP. PVEP may become a useful electrophysiological test in the diagnosis of MV.

Nonsense mutations in the PAX3 gene cause Waardenburg syndrome type I in two Chinese patients.

BACKGROUND: Waardenburg syndrome type I (WS1) is an autosomal dominant disorder characterized by sensorineural hearing loss, pigmental abnormalities of the eye, hair and skin, and dystopia canthorum. The gene mainly responsible for WS1 is PAX3 which is involved in melanocytic development and survival. Mutations of PAX3 have been reported in familiar or sporadic patients with WS1 in several populations of the world except Chinese. In order to explore the genetic background of Chinese WS1 patients, a mutation screening of PAX3 gene was carried out in four WS1 pedigrees. METHODS: A questionnaire survey and comprehensive clinical examination were conducted in four Chinese pedigrees of WS1. Genomic DNA from each patient and their family members was extracted and exons of PAX3 were amplified by PCR. PCR fragments were ethanol-purified and sequenced in both directions on an ABI_Prism 3100 DNA sequencer with the BigDye Terminator Cycle Sequencing Ready Reaction Kit. The sequences were obtained and aligned to the wild type sequence of PAX3 with the GeneTool program. RESULTS: Two nonsense PAX3 mutations have been found in the study population. One is heterozygous for a novel nonsense mutation S209X. The other is heterozygous for a previously reported mutation in European population R223X. Both mutations create stop codons leading to truncation of the PAX3 protein. CONCLUSIONS: This is the first demonstration of PAX3 mutations in Chinese WS1 patients and one of the few examples of an identical mutation of PAX3 occurred in different populations.

[Mutation of GJB2 gene in nonsyndromic hearing impairment patients: analysis of 1190 cases].

OBJECTIVE: To analyze the sequence of GJB2 gene in nonsyndromic hearing impairment (NSHI) patients in China. METHODS: Peripheral blood samples were obtained from 1190 NSHI patients randomly selected from the Deaf and Mute Schools of Beijing, Hebei, Heilongjiang, Jilin, Inner Mongolia, Shanxi, Henan, Hubei, Shaanxi, Gansu, Ningxia, Qinghai, Anhui, Jiangsu, Shanghai, Fujian, Guangdong, and Guangxi, and 301 children with normal hearing level used as controls. Genomic DNA was extracted by extraction kits to undergo polymerase chain reaction and sequencing so as to detect the mutations of GJB2 gene. RESULTS: Sixteen pathogenic mutations of GJB2 gene were found, the most common of which included 235delC, 299-300delAT, and 176del16bp. 250 patients (21.05%) carried definite GJB2 mutations, 245 of which (98%) carried at least one of these 3 common mutations. 222 of the 250 patients (88.80%) carried the mutation 235delC with a detection rate of 18.66%. 62 of the 250 patients (24.80%) carried the mutation 299-300delAT with a detection rate of 5.21%. 19 of the 250 patients (7.60%) carried the mutation 176del16bp with a detection rate of 1.60%. The detection rates of these 3 mutations in the NSHI patients were all significantly higher than those among the controls (all P<0.01). CONCLUSION: The hot spot of GJB2 gene mutations in Chinese NSHI patients is 235delC, followed by 299-300delAT and 176del16bp. These results establish a fundamental basis for drawing a spectrum of GJB2 gene mutation among Chinese population.

A novel mutation of POU3F4 causes congenital profound sensorineural hearing loss in a large Chinese family.

OBJECTIVES/HYPOTHESIS: It is known that approximately 5% of congenital profound hearing impaired cases are inherited in X-linked inheritance. This study aimed at identifying its underlying molecular determinant(s) using a large, five-generation Chinese family with multiple familial cases. STUDY DESIGN: Model-based linkage analysis and positional cloning. METHODS: Model-based genetic linkage analyses were performed with the use of microsatellite polymorphisms to determine disease locus. Mutation screening was performed within the family and unrelated population-based controls to establish molecular evidence as to what caused the specific X-linked inheritance pattern in the family. RESULTS: Clinical investigations of the pedigree demonstrated the extremely high penetrance in the male members but no penetrance in the female members. Linkage analyses mapped the disease to the chromosomal region Xq13.I-Xq23 (maximum X-linkage logarithm of odds score = 3.27). Mutation screening of the candidate genes in the linkage region by direct sequencing revealed a de novo missense substitution (925T>C) in the well-known deaf gene. POU3F4. Direct sequencing on 240 unrelated controls did not detect any mutation. CONCLUSIONS: Multiple analysis approaches demonstrated that these disorders in the family were caused by a founder mutation in the POU3F4 gene. Our findings provided confirmatory molecular evidence to support that development of congenital profound sensorineural hearing loss in the Chinese population results from a novel mutation in the same gene.

Relationship between the external aperture and hearing loss in large vestibular aqueduct syndrome.

BACKGROUND: Large vestibular aqueduct syndrome (LVAS) is a major cause of hearing loss in childhood. This study aimed at measuring external aperture of enlargement of the vestibular aqueduct (EVA) and analyzing relationship between the size of external aperture and hearing loss. METHODS: Diagnostic criteria of LVAS were based on hearing loss and CT images. CT images of temporal bone of 100 LVAS patients were collected and 60 control subjects were reviewed retrospectively in the past 10 years. A battery of audiometric and vestibular function tests were performed. The width of the vestibular aqueduct (VA) was measured on axial CT images of the temporal bone. RESULTS: One hundred patients (65 men, 35 women) were diagnosed as having the isolated EVA. Hearing loss mostly occurred in early childhood. The diagnosis age of LVAS was 7.7 years on average. The causes of hearing loss could not be confirmed by initial consult. Typically, audiometric curve is the high-frequency down-sloping configuration. 92% of the cases had severe or profound sonsorineural hearing loss (SNHL). The mean size of the external aperture was (7.5 +/- 1.2) mm in present LVAS. Statistical analysis showed that the degree of hearing loss is unrelated to the width of VA. CONCLUSIONS: LVAS is a distinct clinical entity characterized by fluctuating, progressive SNHL. The degree of hearing loss is unrelated to the size of external aperture of VA. The protective management and hearing aid have become the main therapies. The cochlear implantation might be performed if the hearing loss affected learning at school.

[Clinical features of a Chinese pedigree with Waardenburg syndrome type 2].

OBJECTIVE: To investigate detailed clinical features of a Chinese pedigree with Waardenburg syndrome type 2. METHODS: Members of this pedigree were interviewed to identify personal or family medical histories of hearing loss, the use of aminoglycosides, and other clinical abnormalities by filling questionnaire. The audiological and other clinical evaluations of the proband and other members of this family were conducted, including pure-tone audiometry, immittance and auditory brain-stem response and ophthalmological, dermatologic, hair, temporal bone CT examinations. RESULTS: This family is categorized as Waardenburg syndrome type 2 according to its clinical features. It's an autosomal dominant disorder with incomplete penetrance. The clinical features varied greatly among family members and characterized by sensorineural hearing loss, heterochromia irides, freckle on the face and premature gray hair. Hearing loss can be unilateral or bilateral, congenital or late onset in this family. CONCLUSION: This Chinese family has some unique clinical features comparing with the international diagnostic criteria for Waardenburg syndrome. This study may provide some evidences to amend the diagnostic criteria for Waardenburg syndrome in Chinese population.

Spontaneous and Partial Repair of Ribbon Synapse in Cochlear Inner Hair Cells After Ototoxic Withdrawal.

Ototoxicity is one of the major causes of sensorineural deafness. However, it remains unclear whether sensorineural deafness is reversible after ototoxic withdrawal. Here, we report that the ribbon synapses between the inner hair cells (IHCs) and spiral ganglion nerve (SGN) fibers can be restored after ototoxic trauma. This corresponds with hearing restoration after ototoxic withdrawal. In this study, adult mice were injected daily with a low dose of gentamicin for 14 consecutive days. Immunostaining for RIBEYE/CtBP2 was used to estimate the number and size of synaptic ribbons in the cochlea. Hearing thresholds were assessed using auditory brainstem responses. Auditory temporal processing between IHCs and SGNs was evaluated by compound action potentials. We found automatic hearing restoration after ototoxicity withdrawal, which corresponded to the number and size recovery of synaptic ribbons, although both hearing and synaptic recovery were not complete. Thus, our study indicates that sensorineural deafness in mice can be reversible after ototoxic withdrawal due to an intrinsic repair of ribbon synapse in the cochlea.

Histological study of experimental reconstructive materials for repair of lateral skull base and dura mater defects in dogs.

OBJECTIVE: In order to assess the reconstructive properties of fascia lata, superficial fascia lata and bone morphogenetic protein (BMP) in skull base surgery, lateral skull base bone and dura mater defect models were established in dogs MATERIAL AND METHODS: As a repair material we selected fascia lata, either alone or in combination with BMP, for reconstructing large cranial defects in dogs. Twenty dogs undergoing a 3.0 x 4.0 cm2 full-thickness excision of the parietal bone were divided into four equal groups as follows: fascia lata reconstruction; fascia lata reconstruction plus BMP; controls; and fascia lata reconstruction plus BMP with direct exposure of fascia lata. The implants were harvested at 2-15 weeks and examined histologically. Results-Treated and untreated implants were quite different: formation of new bone occurred in the dogs treated with BMP whereas the unreconstructed controls demonstrated only a bridge of fibrovascular connective tissue. CONCLUSION: The results of this study suggest that it is better to combine BMP and reconstructive material for the treatment of bone defects.

Basic fibroblast growth factor protects auditory neurons and hair cells from glutamate neurotoxicity and noise exposure.

OBJECTIVE: To determine the protective effects of basic fibroblast growth factor (bFGF) on cochlear neurons and hair cells in vitro and in vivo. MATERIAL AND METHODS: In Experiment I, cultured spiral ganglion neurons (SGNs) prepared from postnatal Day 3 mice were exposed to 20 mM glutamate for 2 h before the culture medium was replaced with fresh medium containing 0, 25, 50 or 100 ng/ml bFGF. Fourteen days later, all cultures were fixed with 4% paraformaldehyde and stained with 1% toluidine blue. The number of surviving SGNs was counted and the length of the neurites of the SGNs was measured. In Experiment II, in vivo studies were carried out with guinea pigs in which bFGF or normal saline was injected intramuscularly to assess possible protective effects of bFGF on cochlear hair cells and to accelerate the recovery of the auditory brainstem response (ABR). The ABRs were measured before, immediately after and 2 and 4 weeks after exposure to noise. RESULTS: Exposure to 20 mM glutamate for 2 h resulted in an inhibition of neurite outgrowth of SGNs and an increase in cell death. Treatment of the cultures with bFGF led to promotion of neurite outgrowth and an increase in the number of surviving SGNs. In Experiment II, significant (p < 0.05) differences in ABR thresholds were observed between the groups injected with bFGF and saline (t = 2.689) at 4 weeks after noise exposure. Cochleae were removed and hair cell loss analyzed in surface preparations prepared from all experimental animals. Acoustic trauma caused loss of 240 and 2160 inner hair cells in the groups injected with bFGF and saline, respectively. Similarly, more outer hair cells were lost in the normal saline injection group (99,291) than in the group treated with bFGF (70,377). CONCLUSIONS: Our results demonstrate that bFGF protects SGNs against glutamate neurotoxicity in vitro. In addition, treatment with bFGF protects hair cells from acoustic trauma.

Protective effect of basic fibroblast growth factor on auditory hair cells after noise exposure.

The purpose of this study was to observe the protective effects of basic fibroblast growth factor (bFGF) on the cells of the inner ear using in vivo experiments. The studies were carried out using guinea pigs in which bFGF or artificial perilymph was perfused into the cochlea. The compound action potential (CAP) was measured before and after exposure to a sound simulating an explosion. The difference in CAP was significant between the bFGF-perfused group and the control group (p < 0.01, t = 3.896) and between the bFGF-perfused group and the artificial perilymph-perfused group (p < 0.05, t = 2.520). The cochleae were removed and hair cell loss estimated from surface preparations. Acoustic trauma caused loss of outer hair cells in the first and second turns of the cochlea in the bFGF-perfused group and the artificial perilymph-perfused group and partial loss of inner hair cells in the control group. Treatment with bFGF reduced the loss of inner hair cells compared to that of control animals. Our results demonstrate that treatment with bFGF protects the hair cells from acoustic trauma and may facilitate the recovery of hearing.

Stereo morphology of temporal bone and ear.

BACKGROUND: The temporal bone has the most complicated anatomic feature among the whole human body, which always challenges otolaryngologists. This study was to study three-dimensional (3D) morphology of the temporal bone and the ear by means of a computer image processing technique, for the purpose of providing a 3D image to help in pathological, diagnostic and surgical procedures. METHODS: Forty sets of temporal bone celloidin serial sections with reference points were prepared and the contours of selected structures and reference points were entered into a graphics programme. The technique of computer-aided 3D reconstruction was applied to obtain 3D images and parameters of the temporal bones and the ears. Stereo views of the ossicles (n = 5), the facial nerves (n = 11), the posterior tympanic sinuses (n = 11), the posterior ampullary nerves (n = 4), the endolymphatic ducts and sacs (n = 5), and the bony and membranous labyrinth (n = 1) were reconstructed. RESULTS: Three-dimensional images, including the cochlea, the ossicles, the nerves, the tendons and the endolymphatic fluid system in the temporal bone, were obtained. Stereo picture pairs and 3D parameters of spatial dimensions, angle and volume for these reconstructed structures were calculated. The arrangement of the ossicles, spatial relationship of the bony and membranous labyrinth, the whole course of the facial nerves, the endolymphatic sac and posterior tympanic cavity were clearly observable. Stereo picture pairs made the spatial relationships among the above-mentioned structures much clearer. The operation of the posterior ampullary nerve transection was designed and simulated on the graphic computer based on 3D anatomic investigations. CONCLUSION: The technique of computer-aided 3D reconstruction provides a new tool to observe the morphology of the temporal bone and thus may allow design and study of new surgical approaches.

[Genetic analysis in a Chinese deaf-mute family with X linked recessive inheritance].

In studying genetic factors in hearing loss among Chinese hearing-impaired population, a Chinese family with deaf-mute that had been reversion inherited through five generations was found (named pedigree L021). X linked recessive inheritance was hypothesized to be the transmission in this family. A total of 64 members in this family were investigated. Of these, audiometric evaluation was performed on 31 members, including 8 males with deaf-mute. Most affected individuals showed deafness or profound sensorineural hearing loss. Blood samples were obtained from 31 consented individuals in this family. Pedigree analysis indicates a X-linked recessive inheritance pattern in pedigree L021. The pedigree described herein provides an excellent model for further study on the molecular mechanism of congenital deaf-mute.

In vivo delivery of Atoh1 gene to rat cochlea using a dendrimer-based nanocarrier.

Gene therapy is a promising clinical solution to hearing loss. However suitable gene carriers for the auditory system are currently unavailable. Given the unique structure of the inner ear, the route of delivery and gene transfer efficiency are still not optimal at present. This study presented a non-viral delivery system of in vivo delivery of Atoh1 gene (a potentially therapeutic gene for hearing loss) to rat cochlea. We treated polyamidoamine (PAMAM) dendrimers by activating and modifying with Na-carboxymethyl-beta-cyclodextrins (CM-beta-CD) in sequence. A novel gene carrier (CM-beta-CD modified activated PAMAM dendrimers, CMAP) was then constructed. CMAP nanoparticles could bind pRK5-Atoh1-EGFP plasmids to form vector-DNA complexes (dendriplexes) with a mean particle size of 132 +/- 20 nm and zeta potential of 31 +/- 3 mV. These dendriplexes were locally applied on the round window membrane and delivered to the inner ear by passive gradient permeation. Results showed that the Atoh1 gene was successfully transferred into the cells as indicated by the green fluorescence detected in the inner ear. A relatively selective gene transfer with high efficiency was achieved in the auditory hair cells but not much in other cell types in the cochlea. Auditory brainstem response was determined seven days after inoculation, indicating good tolerance. This approach may provide a novel tool for inner ear gene therapy and initiate the applications of biomaterials to treat auditory disorders.

Newborn hearing concurrent gene screening can improve care for hearing loss: a study on 14,913 Chinese newborns.

OBJECTIVE: Newborn hearing screening has been widely adopted and made an achievement to some degree. Current screening protocols rely solely on detecting existing auditory disorders at the time of screening and are unable to identify individuals susceptible to auditory disorders in later life. Even if the hearing loss newborn is referred, most cases could not be diagnosed until 6-12 months old with no etiology being elucidated. This study reports the first effort to combine traditional hearing screening with genetic screening to improve the efficacy of newborn hearing screening. METHODS: This study was undertaken in 12 regional hospitals located in 11 provinces of China. 14,913 newborn babies received hearing concurrent genetic screening. The hearing screening was performed with OAE or AABR. Blood sample was collected with a universal newborn genetic screening card. And three common gene, mtDNA 12S rRNA, GJB2 and SLC26A4 were screened with standard protocol. RESULTS: Among all the 14,913 newborns, 86.1% (12,837/14,913) individuals passed the first-step hearing screening, 7.8% (1168/14,913) babies passed only one side, and the other 6.1% (908/14,913) were bilaterally referred. Gene screening found 306 individuals had one or two mutant alleles, the carrier rate is 2.05% (306/14,913) among the entire newborn population. The risk for hearing loss was 100% (7/7) for those newborns carrying causative GJB2 or SLC26A4 mutations (homozygotes or compound heterozygotes), 14.4% (23/160) for GJB2 heterozygote carriers, 12.3% (15/122) for SLC26A2 heterozygous carriers, and the total prevalence of referral hearing screening was approximately 14.7% (45/306). However, 85.3% (261/306) newborns passed hearing screening among these carriers including 18 newborns with 12S rRNA mt.1555A>G pathogenic mutation, who would suffer from sudden hearing loss once applying aminoglycoside drugs. CONCLUSION: The cohort studies provided the essential population parameters for developing effective programs for hearing care of newborns in China. Hearing concurrent gene screening in newborns may confirm the abnormal results from hearing screening tests, help to find the etiologic of the hearing loss, and better recognize infants at risk for late-onset hearing loss occurring prior to speech and language development. In conclusion, a survey on 14,913 Chinese newborns proved that concurrent genetic screening could improve newborn hearing screening for hearing defects.

[Analysis of clinical features of concomitant vertigo in idiopathic sudden deafness].

OBJECTIVE: To analyze the clinical characteristics of concomitant vertigo in patients with sudden deafness (SD). METHODS: Ninety-six cases of SD were reviewed retrospectively from January 2005 to July 2009. SD and benign paroxysmal positional vertigo (BPPV) were diagnosed according to the guides of China Medical Association. The characteristics of vestibular function and the order of the onset of cochlear and vestibular symptoms were analyzed. RESULTS: Of all 96 cases, 23 (24.0%) cases presented with BPPV; 58 (60.4%) cases took the form of unilateral vestibular hypofunction and 15 (15.6%) cases had normal vestibular function. Time interval between cochlear and vestibular symptoms was as follows: 46 patients could tell the exact time of onset of cochlear and vestibular symptoms, of which 6 (13.0%) cases occurred simultaneously; 4 (8.7%) cases presented vertigo within 1 hour after onset of cochlear symptom hypofunction; 21 (45.7%) cases showed time interval between 1 hour and 24 hours; and 13 (28.3%) cases presented vertigo at several days (less than 10 days) after cochlear symptoms. And only in 2 (4.3%) cases did vertigo occur before cochlear symptoms. CONCLUSIONS: Concomitant vertigo in idiopathic SD took the forms of normal or abnormal vestibular function, some of which were BPPV. Occurrence of vertigo was after cochlear symptoms.

[Judgement of disproportionate loss between Mandarin monosyllable discrimination and pure tone hearing thresholds].

OBJECTIVE: To establish the criteria of the disproportionate loss of Mandarin monosyllable discriminative abilities to pure tone hearing thresholds. METHODS: Total of 165 patients with varying degrees of sensorineural hearing loss were recruited for routine audiological evaluations. The speech discrimination scores were obtained by Mandarin phonemic-balanced monosyllable lists via self-made speech audiometric software. The Performance-Intensity (P-I) function for individual ear was obtained by the same list which was administrated in ascending intensities, with 25 monosyllables presenting randomly. The lowest intensity was determined by the lowest pure tone threshold among all audiometric frequencies minus 5 dB. The intensities were increased in 5 dB step until the score was 100% or the intensity was reached to the patient's uncomfortable level. The PB(max) was obtained from the P-I plot. Three parameters about pure tone average hearing thresholds, including PTA(1) (average of 0.5, 1 and 2 kHz), PTA(2) (average of 1, 2 and 4 kHz) and PTA(3) (average of 0.5, 1, 2 and 4 kHz), as well as three parameters about audiogram slope, including Slope(0.5) (4 kHz minus 0.5 kHz), Slope(1) (4 kHz minus 1 kHz) and Slope(2) (4 kHz minus 2 kHz), were calculated respectively. The correlations between PB(max) and above parameters were analyzed by SPSS10.0 statistical software. RESULTS: The audiogram slopes were not shown any correlation with PB(max), while the pure tone average thresholds, especially PTA(3) (r = -0.595, P = 0.000) were confirmed to correlate with PB(max). In the scatter plot based on PB(max) and PTA(3), a linear boundary was constructed encompassing approximately 99% of observed data collected from the sensorineural hearing-impaired. CONCLUSION: Any PB(max) score falling below the boundary should be considered with high possibility and disproportionately poor comparison with pure tone hearing thresholds.

Effect of ancillary ligands on the topoisomerases II and transcription inhibition activity of polypyridyl ruthenium(II) complexes.

To explore the structure-activity relationship of polypyridyl ruthenium(II) complexes as topoisomerase II and T7 RNA polymerase inhibitors, four new complexes, [Ru(4dmb)(2)(ppd)](2+) (4dmb=4,4'-dimethyl-2,2'-bipyridine, ppd=pteridino[6,7-f][1,10] phenanthroline-1,13(10H,12H)-dione), [Ru(5dmb)(2)(ppd)](2+) (5dmb=5,5'-dimethyl-2,2'-bipyridine), [Ru(dip)(2)(ppd)](2+) (dip=4,7-diphenyl-1,10-phenanthroline), and [Ru(ip)(2)(ppd)](2+) (ip=imidazole[4,5-f][1,10]phenanthroline) have been synthesized and characterized in detail by (1)H NMR spectroscopy, mass spectrometry and elemental analysis. Their interaction with calf thymus DNA and the inhibitory activity towards topoisomerase II and T7 RNA polymerase were investigated. The results suggest that although all of these four Ru(II) complexes are potent DNA intercalators, topoisomerase II inhibitors and DNA transcription inhibitors, their DNA binding strength and inhibitory activities are quite different. The activity of ip- and dip-complexes are significantly higher than the dmb-complexes. To explain the experimental regularity and reveal the underlying quantum chemistry mechanism of the biological activity, the properties of energy levels and population of frontier molecular orbitals and excited state transitions of these complexes have been studied by density functional theory (DFT) and time-depended DFT (TDDFT) calculations. The results suggest that ancillary ligands bearing lower energy of the lowest unoccupied molecular orbitals (LUMOs), better hydrophobicity and less steric hindrance of are beneficial to the DNA intercalation and topoisomerase II and DNA transcription inhibition of their complexes.

[Complications of canalith repositioning procedure for benign paroxysmal positional vertigo].

OBJECTIVE: To investigate the incidence of complications of canalith repositioning procedure (CRP) for benign paroxysmal positional vertigo (BPPV) in order to recognize and intervene the complication. METHODS: Totally 430 cases of BPPV were treated by CRP between Jan., 2005 and Nov., 2007. The patients with complication were retreated with CRP according to the new canals otolith falling into. RESULTS: There were 313 patients with posterior canal BPPV, among which 5 had complications during CRP for posterior canal BPPV and 3 for horizontal canal BPPV. And 1 patient transformed from cupulolithiasis to canalithiasis during Semont CRP, which made CRP possible. Three patients had horizontal BPPV during CRP for posterior canal BPPV. Horizontal BPPV emerged during CRP for anterior canal BPPV in 1 patient. CRP for the posterior BPPV had more patients with complication than that of CRP for the anterior BPPV, but the percentage was on the contrary, and they were 1.9% (8/313) and 28.6% (2/7) respectively. The rate of complication during CRP was 3.3% (14/430) and all of them recovered well with CRP. CONCLUSIONS: There are possibility for canal otolith transferred from one canal to another. Careful observation of nystagmus and reevaluation of the patients with BPPV in case of unsuccessful treatments are crucial to determine the complications.

The large Chinese family with Y-linked hearing loss revisited: clinical investigation.

CONCLUSION: The DFNY1 phenotypes shared many characteristics with some autosomal dominant hearing loss, in the aspects of age of onset, severity and audiometric configuration. However, the typical, outstanding feature of this trait was its remarkable pattern of inheritance. Similar traits, if ever encountered, can be most easily identified by discerning this exceptional and rare pattern of inheritance. OBJECTIVES: To analyze the audiological features in Chinese Y-linked non-syndromic hearing impairment, the extended DFNY1 family. SUBJECTS AND METHODS: A nine-generation Chinese family (DFNY1) was ascertained and expanded from the year of 2000 to 2006. The audiometric evaluations included pure-tone audiometry, tympanometry, and auditory brainstem responses. Some subjects received computerized tomography scan of the temporal bone. RESULTS: 52 out of 276 members in this family received clinical examinations. 24 live subjects had hearing impairment consisting of 23 patrilineal males and one female. In the affected lineage, 92% patrilineal males were well characterized as having hearing loss and 2 children remained to be diagnosed. Based on the audiological examinations on the male members, the degree of hearing loss was from mild (3 patients), moderate (7 patients) to severe (11 patients). The audiometry displayed 48% subjects with sloping in high frequencies, 38% flat in all frequencies, and the rest (14%) the U-shape. The age of onset ranged from 5-27 years with the average of 11.5 years.