Effect of biopolymer chitosan on manganese immobilization improvement by microbial­induced carbonate precipitation.

Microbially induced carbonate precipitation (MICP), as an eco-friendly and promising technology that can transform free metal ions into stable precipitation, has been extensively used in remediation of heavy metal contamination. However, its depressed efficiency of heavy metal elimination remains in question due to the inhibition effect of heavy metal toxicity on bacterial activity. In this work, an efficient, low-cost manganese (Mn) elimination strategy by coupling MICP with chitosan biopolymer as an additive with reduced treatment time was suggested, optimized, and implemented. The influences of chitosan at different concentrations (0.01, 0.05, 0.10, 0.15 and 0.30 %, w/v) on bacterial growth, enzyme activity, Mn removal efficiency and microstructure properties of the resulting precipitation were investigated. Results showed that Mn content was reduced by 94.5 % within 12 h with 0.15 % chitosan addition through adsorption and biomineralization as MnCO3 (at an initial Mn concentration of 3 mM), demonstrating a two-thirds decrease in remediation time compared to the chitosan-absent system, whereas maximum urease activity increased by ∼50 %. Microstructure analyses indicated that the mineralized precipitates were spherical-shaped MnCO3, and a smaller size and more uniform distribution of MnCO3 is obtained by the regulation of abundant amino and hydroxyl groups in chitosan. These results demonstrate that chitosan accelerates nucleation and tunes the growth of MnCO3 by providing nucleation sites for mineral formation and alleviating the toxicity of metal ions, which has the potential to upgrade MICP process in a sustainable and effective manner. This work provides a reference for further understanding of the biomineralization regulation mechanism, and gives a new perspective into the application of biopolymer-intensified strategies of MICP technology in heavy metal contamination.

Diagnostic value of nerve conduction study in NOTCH2NLC-related neuronal intranuclear inclusion disease.

BACKGROUND AND AIMS: Neuronal intranuclear inclusion disease (NIID) is a rare progressive neurodegenerative disorder mainly caused by abnormally expanded GGC repeats within the NOTCH2NLC gene. Most patients with NIID show polyneuropathy. Here, we aim to investigate diagnostic electrophysiological markers of NIID. METHODS: In this retrospective dual-center study, we reviewed 96 patients with NOTCH2NLC-related NIID, 94 patients with genetically confirmed Charcot-Marie-Tooth (CMT) disease, and 62 control participants without history of peripheral neuropathy, who underwent nerve conduction studies between 2018 and 2022. RESULTS: Peripheral nerve symptoms were presented by 53.1% of patients with NIID, whereas 97.9% of them showed peripheral neuropathy according to electrophysiological examinations. Patients with NIID were characterized by slight demyelinating sensorimotor polyneuropathy; some patients also showed mild axonal lesions. Motor nerve conduction velocity (MCV) of the median nerve usually exceeded 35 m/s, and were found to be negatively correlated with the GGC repeat sizes. Regarding the electrophysiological differences between muscle weakness type (n = 27) and non-muscle weakness type (n = 69) of NIID, nerve conduction abnormalities were more severe in the muscle weakness type involving both demyelination and axonal impairment. Notably, specific DWI subcortical lace sign was presented in only 33.3% of muscle weakness type, thus it was difficult to differentiate them from CMT. Combining age of onset, distal motor latency, and compound muscle action potential of the median nerve showed the optimal diagnostic performance to distinguish NIID from major CMT (AUC = 0.989, sensitivity = 92.6%, specificity = 97.4%). INTERPRETATION: Peripheral polyneuropathy is common in NIID. Our study suggest that nerve conduction study is useful to discriminate NIID.

Genotype and phenotype distribution of 435 patients with Charcot-Marie-Tooth disease from central south China.

BACKGROUND AND PURPOSE: The purpose was to provide an overview of genotype and phenotype distribution in a cohort of patients with Charcot-Marie-Tooth disease (CMT) and related disorders from central south China. METHODS: In all, 435 patients were enrolled and detailed clinical data were collected. Multiplex ligation-dependent probe amplification for PMP22 duplication/deletion and CMT multi-gene panel sequencing were performed. Whole exome sequencing was further applied in the remaining patients who failed to achieve molecular diagnosis. RESULTS: Among the 435 patients, 216 had CMT1, 14 had hereditary neuropathy with pressure palsies (HNPP), 178 had CMT2, 24 had distal hereditary motor neuropathy (dHMN) and three had hereditary sensory and autonomic neuropathy (HSAN). The overall molecular diagnosis rate was 70%: 75.7% in CMT1, 100% in HNPP, 64.6% in CMT2, 41.7% in dHMN and 33.3% in HSAN. The most common four genotypes accounted for 68.9% of molecular diagnosed patients. Relatively frequent causes were missense changes in PMP22 (4.6%) and SH3TC2 (2.3%) in CMT1; and GDAP1 (5.1%), IGHMBP2 (4.5%) and MORC2 (3.9%) in CMT2. Twenty of 160 detected pathogenic variants and the associated phenotypes have not been previously reported. Broad phenotype spectra were observed in six genes, amongst which the pathogenic variants in BAG3 and SPTLC1 were detected in two sporadic patients presenting with the CMT2 phenotype. CONCLUSIONS: Our results provided a unique genotypic and phenotypic landscape of patients with CMT and related disorders from central south China, including a relatively high proportion of CMT2 and lower occurrence of PMP22 duplication. The broad phenotype spectra in certain genes have advanced our understanding of CMT.

Improved mineralization of dental enamel by electrokinetic delivery of F- and Ca2+ ions.

This in vitro study evaluated the effects of the infiltration of F- and Ca2+ ions into human enamel by electrokinetic flow (EKF) on the enamel microhardness and F- content. Sound human enamel ground sections of unerupted third molars were infiltrated with de-ionized water by EKF and with F- ion by EKF respectively. All samples were submitted to two successive transverse acid-etch biopsies (etching times of 30 s and 20 min) to quantify F- ion infiltrated deep into enamel. Remarkably, sound enamel showed a large increase in microhardness (MH) after infiltration of NaF (p < 0.00001) and CaCl2 (p = 0.013) by EKF. Additionally, NaF-EKF increased the remineralization in the lesion body of artificial enamel caries lesions compared to controls (p < 0.01). With the enamel biopsy technique, at both etching times, more F- ions were found in the EKF-treated group than the control group (p << 0.05), and more fluoride was extracted from deeper biopsies in the NaF-EKF group. In conclusion, our results show that EKF treatment is superior in transporting Ca2+ and F- ions into sound enamel when compared to molecular diffusion, enhancing both the mineralization of sound enamel and the remineralization of artificial enamel caries.

Attitudes towards and use of dental dams by final-year dental students in Chongqing, China: a cross-sectional study.

OBJECTIVES: To investigate the current and intended future use of dental dams (DDs) and attitudes regarding DD use among final-year dental students at two levels (undergraduate and college) in dental schools in Chongqing, China. DESIGN: A cross-sectional study based on a questionnaire was conducted from June to July 2021. SETTING: Chongqing Medical University (CQMU, undergraduate level) and Chongqing Three Gorges Medical College (CQTGMC, junior college level). PARTICIPANTS: A total of 245 final-year dental students. MAIN OUTCOME MEASURES: An anonymous online questionnaire was distributed to dental students less than 1 month before graduation. Students were asked about the DD training they had received, their attitudes towards some aspects of DDs, their current DD use and their intended future DD use in adult or child patients and in various dental procedures. RESULTS: A total of 238 valid questionnaires were returned (response rate=97.1%, CQMU=96.2%, n=76; CQTGMC=97.6%, n=162). A total of 47.5% of respondents used DDs on real patients during their internships (CQMU=59.2%, CQTGMC=42.0%, p<0.05). Whether in restorative procedures or endodontic treatment, the most common reason for not using DDs was a 'lack of knowledge and experience', followed by 'DDs could not be provided by internship institutions'. Although the advantages of DDs were recognised by most students from the two schools, 52.9% thought DDs were difficult to apply (CQMU=42.1%, CQTGMC=58.0%, p<0.05). A total of 92.1% of CQMU respondents and 95.1% of CQTGMC respondents expressed their willingness to use DDs after independent practice in the future. CONCLUSIONS: Although final-year students have a clear awareness of the advantages of DDs and are very enthusiastic about future DD use, the current DD utilisation rate is low. Education about DDs should be continuously improved in many aspects, and the advantages of using DDs in clinical dentistry should be further emphasised at dental schools.

The Biosafety Evaluation for Crustaceans: A Novel Molluscicide PBQ Using against Oncomelania hupensis, the Intermediate Host of Schistosoma japonica.

A new formulation (suspension concentrate, SC) of PBQ [1-(4-chlorophenyl)-3-(pyridin-3-yl) urea] was used in water network schistosomiasis-endemic areas to test its molluscicidal efficacy and the acute toxicity to crustaceans. PBQ (20% SC), 26% metaldehyde, and niclosamide suspension concentrate [MNSC (26% SC)] were used both in ditch and field experiments for the molluscicidal efficacy comparison. Acute toxicity tests of two molluscicides were conducted using Neocaridina denticulate and Eriocheir sinensis. Both in the field and ditch experiments, PBQ exhibited comparable molluscicidal efficacy with MNSC. At doses of 0.50 g/m3 and 0.50 g/m2, the snail mortalities were more than 90% three days after PBQ (20% SC) application. Compared with previous tests, PBQ (20% SC) exhibited higher molluscicidal activity than PBQ (25% wettable powder, 25% WP) used in Jiangling and showed similar mollucicidal activity to PBQ (25% WP) used in Dali and Poyang Lake. The 96 h LC50 value of MNSC against Eriocheir sinensis was 283.84 mg a.i./L. At the concentration of PBQ (20% SC) 1000 mg a.i./L, all Eriocheir sinensis were alive. The 96 h LC50 values of PBQ and MNSC against Neocaridina denticulate were 17.67 and 14.05 mg a.i./L, respectively. In conclusion, PBQ (20% SC) had a comparable molluscicidal efficacy with MNSC (26% SC) and PBQ (25% WP). Furthermore, it showed lower toxicity to the crustacean species, better solubility, no floating dust, and convenience for carriage. PBQ (20% SC) was suitable for controlling snails in the water network schistosomiasis-endemic areas.

[Effect of malocclusion on self-esteem of children aging 8 to 10 years in Chongqing].

PURPOSE：This study was aimed to investigate the effect of malocclusion on self-esteem of children aging 8 to 10 years in Chongqing. METHODS：According to the standards of the Fourth National Oral Health Epidemiological sampling survey，a multistage, stratified, cluster, and random sampling method was used to select 1 588 children from 12 schools in 3 districts and 3 counties in Chongqing. The part of tooth health of the Index of Orthodontic Treatment Need (IOTN) was used to evaluate malocclusion. The aesthetic part of the IOTN was used to evaluate the subjective orthodontic treatment need. The Harter's Self-perception Profile for Children was used to evaluate the self-esteem. The data were analyzed with SPSS 20.0 software package. RESULTS: Subjective orthodontic treatment need IOTN-AC(moderate severe), overjet (severe: 6-9 mm, >9 mm), anterior crossbite, open bite, caries located in the anterior tooth area were negatively correlated with self-esteem(P<0.05). CONCLUSIONS： Subjective orthodontic treatment need and malocclusion, especially the types that have great influence on beauty obviously affect children's self-esteem. It is necessary to increase the investment and education of early orthodontic intervention.

One PMP22/MPZ and Three MFN2/GDAP1 Concomitant Variants Occurred in a Cohort of 189 Chinese Charcot-Marie-Tooth Families.

BACKGROUND AND AIMS: Charcot-Marie-Tooth (CMT) disease is a clinically and genetically heterogeneous group of inherited peripheral neuropathies. The wide phenotypic variability may not be completely explained by a single mutation. AIMS AND METHODS: To explore the existence of concomitant variants in CMT, we enrolled 189 patients and performed molecular diagnosis by application of next-generation sequencing combined with multiplex ligation-dependent probe amplification. We conducted a retrospective analysis of patients harboring coinherited variants in different genes. RESULTS: Four families were confirmed to possess variants in two genes, accounting for 2.1% (4/189) of the total in our cohort. One CMT1 patient with PMP22 duplication and MPZ variant (c.286A>C, p.K96Q) exhibited moderate neuropathy with infantile onset, while her father possessing MPZ variant was mildly affected with adolescence onset. A CMT2 patient with heterozygous variants in MFN2 (c.613_622delGTCACCACAG, p.V205Sfs*26) and GDAP1 (c.713G>T, p.W238L) exhibited childhood onset mild phenotype, while his mother with MFN2 variant developed bilateral pes cavus only. A CMT2 patient with heterozygous variants in MFN2 (c.839G>A, p.R280H) and GDAP1 (c.3G>T, p.M1?) presented infantile onset and rapid progression, while her father with MFN2 variant presented with absence of deep tendon reflexes. One sporadic CMT2 patient with early onset was confirmed harboring de novo MFN2 variant (c.1835C>T, p.S612F) and heterozygous GDAP1 variant (c.767A>G, p.H256R). CONCLUSION: Our results suggest that the possibility of concomitant variants was not uncommon and should be considered when significant intrafamilial clinical heterogeneity is observed.

Genetic and Clinical Features in 24 Chinese Distal Hereditary Motor Neuropathy Families.

Background and Objectives: Distal hereditary motor neuropathy (dHMN) is a clinically and genetically heterogeneous group of inherited neuropathies. The objectives of this study were to report the clinical and genetic features of dHMN patients in a Chinese cohort. Aims and Methods: We performed clinical assessments and whole-exome sequencing in 24 dHMN families from Mainland China. We conducted a retrospective analysis of the data and investigated the frequency and clinical features of patients with a confirmed mutation. Results: Two novel heterozygous mutations in GARS, c.373G>C (p.E125Q) and c.1015G>A (p.G339R), were identified and corresponded to the typical dHMN-V phenotype. Together with families with WARS, SORD, SIGMAR1, and HSPB1 mutations, 29.2% of families (7/24) acquired a definite genetic diagnosis. One novel heterozygous variant of uncertain significance, c.1834G>A (p.G612S) in LRSAM1, was identified in a patient with mild dHMN phenotype. Conclusion: Our study expanded the mutation spectrum of GARS mutations and added evidence that GARS mutations are associated with both axonal Charcot-Marie-Tooth and dHMN phenotypes. Mutations in genes encoding aminoamide tRNA synthetase (ARS) might be a frequent cause of autosomal dominant-dHMN, and SORD mutation might account for a majority of autosomal recessive-dHMN cases. The relatively low genetic diagnosis yield indicated more causative dHMN genes need to be discovered.

Deformation behavior of normal human enamel: A study by nanoindentation.

Tooth enamel has an important mechanical function for human dental health, yet characterizing its mechanical properties is not trivial due to its complex nanoporous structures. We examined the distribution of hardness and modulus across the lingual-buccal enamel cross-section by nanoindentation. At the occlusal surface, the hardness and modulus of enamel were found to be 5.00 ± 0.22 GPa and 97.12 ± 2.95 GPa, respectively. At the area close to the enamel-dentine-junction (EDJ), the hardness and modulus were 3.72 ± 0.35 GPa and 76.83 ± 5.71 GPa, respectively. At the middle region in between the EDJ and the outer enamel layer, the hardness and modulus were found to be 4.23 ± 0.18 GPa and 87.62 ± 2.50 GPa, respectively. The surface and area underneath the nanoindent were analyzed using the following microscopy tools: Scanning Electron Microscopy, Focused Ion Beam imaging, and Transmission Electron Microscopy. The deformation mechanisms of enamel were found to be location dependent and influenced by changes in the chemical composition within enamel. The EDJ forms the interface between enamel and dentin. The deformation behavior differed at the EDJ, due to the increased organic phase at the interface. Within the intermediate enamel region, intra-rod cracks were formed at the center of enamel rods and propagated into the neighboring inter-rod region at deviated directions along the orientation of the local crystallites. At the outer enamel layer, crack propagation was constrained by the rigid structure surrounding the indented site. Most of the cracks were formed close to the surface. A significant amount of material was also pushed upwards and delaminated from the enamel surface of the indentation area.

Effects of dental general anaesthesia treatment on early childhood caries: a prospective cohort study in China.

OBJECTIVES: To evaluate the success rates of dental procedures, the recurrence rates of caries and changes in oral health-related quality of life (OHRQoL) in children following treatment for early childhood caries (ECC) under dental general anaesthesia (DGA) in Chongqing, China. DESIGN: A single-centre prospective cohort study conducted from December 2016 to June 2017. SETTING: A tertiary stomatological hospital in Chongqing, China. PARTICIPANTS: A total of 159 children aged 2-5 years who received treatment for ECC under DGA were included. MAIN OUTCOME MEASURES: The primary outcomes were the success rates of dental procedures (the number of successful procedures divided by the total number of procedures) and the recurrence rates of caries. The success and recurrence rates were evaluated by a specialised examiner. The secondary outcome was the change in children's OHRQoL after DGA treatment, which was measured with the Early Childhood Oral Health Impact Scale (ECOHIS). RESULTS: Overall, 117 children (73.6%) and 101 children (63.5%) participated in 6-month and 12-month clinical examinations, respectively, and 151 children (95.0%) completed OHRQoL surveys pretreatment and at 1, 3, 6 and 12 months post-treatment. The resin composite, stainless steel crown, indirect pulp capping, pulpectomy, space maintenance and dental sealant success rates were 89.6%, 96.3%, 96.0%, 94.4%, 76.9% and 92.9%, respectively, at 6 months and 78.8%, 95.1%, 92.2%, 88.9%, 63.6% and 89.3%, respectively, at 12 months. 10 (8.5%) and 19 children (18.8%) developed recurrent caries within 6 and 12 months, respectively. Within 1 year of treatment, the total ECOHIS scores at each post-treatment time point were still significantly lower than those at pretreatment, although they had increased slowly over time. CONCLUSIONS: Overall, high success rates were obtained for the dental procedures, and the children's OHRQoL significantly improved after treatment. However, there was a tendency towards caries relapse, and the children's OHRQoL deteriorated over time.

[Prevalence of dental caries and associated factors among 10-12-year-old students in Chongqing].

OBJECTIVE: To investigate the caries status of the first permanent molars in urban and rural children aged 10-12 in Chongqing and analyze the related factors in order to provide a theoretical basis for the prevention and treatment of children's caries and targeted suggestions for oral health education. METHODS: A multi-stage, stratified, cluster, and random sampling method was used to extract 5 057 children from 18 schools in three districts and three counties in Chongqing for oral health examination and questionnaire survey from March to May 2018. RESULTS: The total caries rate of the first permanent molar was 39.2%. The decayed-missing-filled tooth was 0.84±1.20. The rate of filling teeth was 3.4%. The rate of pit and fissure sealing was 6.1%. The prevalence of the first permanent molars was significantly different between men and women, between urban and rural areas, between only children and non-only children, and between ethnic minorities and Han nationality (P<0.001). The gap between the pit and fissure sealing was significantly different between urban and rural areas (P<0.001). Multiple logistic regression analysis showed that many independent factors influence the occurrence of caries, including the frequency of brushing teeth every day, the frequency of eating desserts, the habit of eating dessert/drinking milk before going to bed, whether only-children or not, and parents' education background, among others. CONCLUSIONS: The first permanent molars of children aged 10-12 in Chongqing have a high rate of caries but low rates of pit and fissure sealing and dental caries filling. The difference between urban and rural areas is large, children's oral health knowledge is scarce, and children have bad oral hygiene behaviors and eating habits. Children's oral health education must be strengthened, oral health preaching must be implemented in schools, the oral health knowledge of children in school must be improved, and urban-rural differences must be minimized.

Novel mutation of EDA causes new asymmetrical X-linked hypohidrotic ectodermal dysplasia phenotypes in a female.

Hypohidrotic ectodermal dysplasia (HED) is a rare hereditary disorder that affects tissues derived from the ectoderm including hair, teeth and sweat glands. EDA is the major causative gene of HED. This study recruited a Chinese family with HED, including a male proband and his mother with a fetus. The proband had typical clinical features of HED and the mother had identical but milder features. Interestingly, some phenotypes of the mother appeared asymmetrically between the right and left side of the body that were not reported in previous studies. Targeted sequencing was performed in the proband and a novel frame-shift mutation (NM_001399.4: c.381_382delinsG, p.Q128Rfs*9) in EDA was found. Sanger sequencing validated the mutation and identified the same mutation in the mother. Our study expands the clinical and genetic spectrum of EDA-related disorders and reports new asymmetrical phenotypes in a female.

Analysis of Salivary Microbiome in Patients with Alzheimer's Disease.

Recent studies found that poor oral hygiene was associated with increased risk of dementia, and the number of oral bacteria significantly increased in the brain tissues of patients with Alzheimer's disease (AD), suggesting that the oral microbiota may play an important role in the pathogenesis of AD. However, the actual composition of oral bacteria communities in patients with AD and whether these oral bacteria are associated with disease severity remain largely unknown. Also, the APOEɛ4 polymorphism is a strong risk factor for sporadic AD, and it would be pertinent to see if the bacterial flora was different in those patients who were APOEɛ4 positive. A total of 78 subjects were recruited in this study, including 39 patients with AD and 39 healthy controls. Saliva was collected from each subject. 16S ribosomal RNA (16S rRNA) sequencing was conducted to analyze the salivary microbiota, and Sanger sequencing was performed to analyze the APOE genotype. There was a significantly lower richness and diversity of saliva microbiota detected in AD patients than healthy controls. The relative abundance of Moraxella, Leptotrichia, and Sphaerochaeta in the saliva of AD patients greatly increased, whereas that of Rothia was significantly reduced. Compared with APOEɛ4 (-) patients, the level of Abiotrophia and Desulfomicrobium was comparatively abundant, while Actinobacillus and Actinomyces decreased significantly in patients carrying the APOEɛ4. No bacteria were found to be associated with the severity of AD. This is the first study to analyze the salivary microorganisms in patients with AD, and we discovered that the composition of salivary microbiome was altered in AD, providing further support for the role of the oral microbiome in AD development.

Identification of TYW3/CRYZ and FGD4 as susceptibility genes for amyotrophic lateral sclerosis.

OBJECTIVE: A 2-stage genome-wide association was conducted to explore the genetic etiology of amyotrophic lateral sclerosis (ALS) in the Chinese Han population. METHODS: Totally, 700 cases and 4,027 controls were genotyped in the discovery stage using Illumina Human660W-Quad BeadChips. Top associated single nucleotide polymorphisms from the discovery stage were then genotyped in an independent cohort with 884 cases and 5,329 controls. Combined analysis was conducted by combining all samples from the 2 stages. RESULTS: Two novel loci, 1p31 and 12p11, showed strong associations with ALS. These novel loci explained 2.2% of overall variance in disease risk. Expression quantitative trait loci searches identified TYW/CRYZ and FGD4 as risk genes at 1p13 and 12p11, respectively. CONCLUSIONS: This study identifies novel susceptibility genes for ALS. Identification of TYW3/CRYZ in the current study supports the notion that insulin resistance may be involved in ALS pathogenesis, whereas FGD4 suggests an association with Charcot-Marie-Tooth disease.

Prevalence of malocclusion in primary dentition in mainland China, 1988-2017: a systematic review and meta-analysis.

Malocclusion is a common oral disease affecting children with various reported prevalence rates. This meta-analysis aimed to determine the epidemiological characteristics of malocclusion among pre-schoolers in mainland China from 1988 to 2017. A total of 31 qualified papers describing 51,100 Chinese children aged 2-7 years were selected. The pooled malocclusion prevalence was 45.50% (95% confidence interval (CI): 38.08-52.81%) with 26.50% Class I (CI: 19.96-33.12%), 7.97% Class II (CI: 6.06-9.87%) and 12.60% Class III (CI: 9.45-15.68%) cases. The most common type of malocclusion was overbite (33.66%, CI: 27.66-39.67%), and the flush terminal type (47.10%, CI: 28.76-65.44%) was the most common in the terminal plane relationship. An increasing trend and wide variations across the country were observed. Additionally, there was no significant difference in malocclusion by gender (relative risk (RR) = 1.01, [0.96-1.06]) or urban/rural area (RR = 0.99, [0.82-1.20]). Although this study represents a narrow view of deciduous-dentition malocclusion in mainland China, the results provide sample evidence that can aid clinicians and policy makers towards early prevention and timely treatment.

Fibroblast growth factor 2 dimer with superagonist in vitro activity improves granulation tissue formation during wound healing.

Site-specific chemical dimerization of fibroblast growth factor 2 (FGF2) with the optimal linker length resulted in a FGF2 homodimer with improved granulation tissue formation and blood vessel formation at exceptionally low concentrations. Homodimers of FGF2 were synthesized through site-specific linkages to both ends of different molecular weight poly(ethylene glycols) (PEGs). The optimal linker length was determined by screening dimer-induced metabolic activity of human dermal fibroblasts and found to be that closest to the inter-cysteine distance, 70 Å, corresponding to 2 kDa PEG. A straightforward analysis of the kinetics of second ligand binding as a function of tether length showed that, as the polymerization index (the number of monomer repeat units in the polymer, N) of the tether decreases, the mean time for second ligand capture decreases as ∼N(3/2), leading to an enhancement of the number of doubly bound ligands in steady-state for a given (tethered) ligand concentration. FGF2-PEG2k-FGF2 induced greater fibroblast metabolic activity than FGF2 alone, all other dimers, and all monoconjugates, at each concentration tested, with the greatest difference observed at low (0.1 ng/mL) concentration. FGF2-PEG2k-FGF2 further exhibited superior activity compared to FGF2 for both metabolic activity and migration in human umbilical vein endothelial cells, as well as improved angiogenesis in a coculture model in vitro. Efficacy in an in vivo wound healing model was assessed in diabetic mice. FGF2-PEG2k-FGF2 increased granulation tissue and blood vessel density in the wound bed compared to FGF2. The results suggest that this rationally designed construct may be useful for improving the fibroblast matrix formation and angiogenesis in chronic wound healing.

Mutation analysis of the small heat shock protein 27 gene in chinese patients with Charcot-Marie-Tooth disease.

BACKGROUND: Charcot-Marie-Tooth (CMT) disease, the most common hereditary peripheral neuropathy, is highly clinically and genetically heterogeneous, and mutations in at least 18 genes have been identified. Recently, mutations in small heat shock protein 27 (Hsp27) were reported to cause CMT disease type 2F and distal hereditary motor neuropathy. OBJECTIVE: To investigate the frequency and phenotypic features of an Hsp27 mutation in Chinese patients with CMT disease. DESIGN: DNA samples from 114 unrelated patients with CMT disease were screened for mutations in Hsp27 by polymerase chain reaction and direct sequencing. A cosegregated study was performed using the MbiI restriction endonuclease, and 50 healthy control subjects were analyzed. Haplotype analysis was performed using 5 short tandem repeat markers to analyze whether the families with the same mutation probably had a common ancestor. RESULTS: One missense mutation, C379T, was detected in 4 autosomal dominant families with CMT disease type 2, and haplotype analysis indicated that the 4 families probably had a common founder. The frequency of the Hsp27 mutation is 0.9% (1/111) in Chinese patients with CMT disease in our study, and the phenotypes were characterized by later onset (age, 35-60 years) and mild sensory impairments. Electrophysiological findings showed moderately to severely slowed nerve conduction velocities in lower limb nerves but normal or mildly reduced velocities in upper limb nerves. CONCLUSIONS: To our knowledge, this is the first report of an Hsp27 mutation in the People's Republic of China. The C379T mutation in Hsp27 also causes CMT disease type 2, except for distal hereditary motor neuropathy, and the phenotypes are distinct from the family with CMT disease type 2F described previously. A mutation of Hsp27 may be uncommon in Chinese patients with CMT disease.

[Mutation analysis of small heat shock protein 27 gene in Chinese patients with Charcot-Marie-Tooth disease].

OBJECTIVE: To investigate the features of small heat shock protein 27 (HSP27) gene mutation in Chinese patients with Charcot-Marie-Tooth disease (CMT). METHODS: DNA samples from 114 CMT probands were screened for mutations in HSP27 gene by polymerase chain reaction and direct sequencing, and haplotype analysis was further carried out on the mutation detected families. RESULTS: One missense mutation C379T was detected in 4 autosomal dominant CMT2 families. Haplotype analysis indicated that the 4 families probably had a common ancestor. CONCLUSION: To the authors' knowledge, this is the first report of HSP27 gene mutation in Chinese patients with CMT, but it may be not common(0.90%). The C379T mutation in HSP27 gene also causes CMT2 except for distal hereditary motor neuropathy, thus providing further evidence that even the same mutation in the same gene may lead to distinct phenotypes.

Mutation screening of Cx32 in Han Chinese patients with Charcot-Marie-Tooth disease.

OBJECTIVE: To investigate the Cx32 mutation features and the clinical manifestations of Chinese patients with Charcot-Marie-Tooth disease(CMT). METHODS: Twenty-four of 65 unrelated CMT patients were selected for Cx32 mutation screening after the exclusion of the CMT1A 1.5 Mb duplication and male-to-male transmission. The motor and sensory nerve conduction studies were performed in all probands and most of their affected family members to establish the clinical CMT1 ,CMT2 or CMT intermediate diagnosis. The presence of mutations in the coding region of Cx32 was detected by single-strand conformation polymorphism analysis combined with direct sequencing. RESULTS: We found 7 different point mutations in the coding region of Cx32 in a total of 7 families. All the patients were mildly to moderately affected with a clinical CMT1 or CMT intermediate diagnosis. The mutation Arg15Gln was inherited with X-linked recessive trait in family 1 involved in our study. The Arg75Trp mutation was detected in a family with X-linked dominant CMT and autosomal recessive nonsydromic hearing loss. The clinical phenotype of the Thr188Ala mutation was firstly reported. CONCLUSION: Seven different Cx32 point mutations were detected and the percentage of Chinese CMT families with Cx32 mutation is about 10% in our study. The inheritance model of CMT secondary to Cx32 mutation could be X-linked dominant, X-linked recessive or sporadic. Male patients are usually more severely affected than females with slower nerve conduction velocities. Cx32 mutation screening should be firstly performed in those CMT families without male-to-male transmission and CMT1A duplication.