[Cases of hepatitis C virus infection with 2i/2a recombination genotype in the Lanzhou area and effects of related genetic variations on interferon alpha response].

OBJECTIVE: To investigate Lanzhou area cases of hepatitis C virus (H-CV) infection with a 5'-non coding region (NCR) 2i genotype and core (C), envelope protein (E) and non-structural protein (NS5) 2a genotype and the relationship with therapeutic response to interferon-alpha (IFNa). METHODS: Nine patients who received IFNa-based treatment for HCV between 2007 and 2009 at the Second People's Hospital of Gansu Province were selected for analysis.Restriction enzyme analysis was carried out for the 5'-NCR and sequencing was carried out for the other gene areas.The relationship between genetic variants and IFNaresponse was examined. RESULTS: Of the total nine HCV cases treated with IFNa-based therapies, five of the patients achieved sustained virological response (SVR), which included two cases with type 2 genotype and three cases with no MboI restriction enzyme point of tangency (i.e.type 1b). The remaining four patients that did not achieve SVR included one case of type 2a, with a 1b and 2a mixed state, and one case with 5'-NCR 2i genotype and C area, NS5 area 2a genotype; the other two cases had 5'-NCR and C area type 1b. Of the five cases with 5'-NCR 2i genotype, all had C 2a genotype and two had C/E 2a and NS5 2a genotypes.The seven patients that showed no response to ordinary IFNa were converted to long-term IFNa plus ribavirin combination antiviral treatment; five (71.4%) of the cases showed response in HCV RNA level and the patients treated with the pegylated form showed greater response. CONCLUSION: HCV genotyping can only provide information on the particular region of gene sequence examined, and it is important to sequence all gene regions where mutations related to antiviral drug response are located. Peg-IFNa-2a combined with ribavirin may achieve better therapeutic effect in patients infected with 2i/2a recombinant forms of HCV.

Tannic acid induces dentin biomineralization by crosslinking and surface modification.

It is currently known that crosslinking agents can effectively improve the mechanical properties of dentin by crosslinking type I collagen. However, few scholars have focused on the influence of crosslinking agents on the collagen-mineral interface after crosslinking. Analysis of the Fourier transform infrared spectroscopy (FTIR) results showed that hydrogen bonding occurs between the tannic acid (TA) molecule and the collagen. The crosslinking degree of TA to collagen reached a maximum 41.28 ± 1.52. This study used TA crosslinked collagen fibers to successfully induce dentin biomineralization, and the complete remineralization was achieved within 4 days. The crosslinking effect of TA can improve the mechanical properties and anti-enzyme properties of dentin. The elastic modulus (mean and standard deviation) and hardness values of the remineralized dentin pretreated with TA reached 19.1 ± 1.12 GPa and 0.68 ± 0.06 GPa, respectively, which were close to those of healthy dentin measurements, but significantly higher than those of dentin without crosslinking (8.91 ± 1.82 GPa and 0.16 ± 0.01 GPa). The interface energy between the surface of collagen fibers and minerals decreased from 10.59 mJ m-2 to 4.19 mJ m-2 with the influence of TA. The current work reveals the importance of tannic acid crosslinking for dentin remineralization while providing profound insights into the interfacial control of biomolecules in collagen mineralization.

Mucopolysaccharidosis III in Mainland China: natural history, clinical and molecular characteristics of 34 patients.

Objectives Sanfilippo syndrome (Mucopolysaccharidosis III, MPS III) is a rare autosomal recessive hereditary disease, which is caused by lysosomal enzyme deficiency. This study was operated to investigate clinical and molecular characteristics of patients with MPS III, which will improve the diagnosis and treatment of MPS III. Method Thirty four patients with MPS III were assessed using clinical evaluation, questionnaire, and scoring system. Results Among the 34 patients, 14 had MPS IIIA, 19 had MPS III B, and one had MPS III C. Speech delay (100%) and intellectual disability (100%) were the most prevalent clinical manifestations in this cohort, followed by hyperactivity (94.12%), hirsutism (91.18%), enlarged head circumference (73.52%), repeated diarrhea (67.64%), sparse teeth (67.64%), and Mongolian spots (64.71%). There were two clinical manifestations that were significantly different between IIIA and IIIB: Hepatosplenomegaly and serrated teeth. The most common initial symptoms at diagnosis were speech delay (52.94%), hyperactivity (35.29%), and mental retardation (29.41%). Genetic analysis of 25 patients was conducted, which identified 12 novel mutations. Conclusion When language retardation, mental retardation, and rough facial features occurred, MPS III should be considered. At same time, more examination should be operated, such as examination of changes in cranial magnetic resonance imaging of cerebral cortex atrophy. Hepatosplenomegaly and serrated teeth could be used clinically to preliminarily distinguish IIIA from IIIB.

Polydopamine Promotes Dentin Remineralization via Interfacial Control.

Biomineralization has intrigued researchers for decades. Although mineralization of type I collagen has been universally investigated, this process remains a great challenge due to the lack of mechanistic understanding of the roles of biomolecules. In our study, dentine was successfully repaired using the biomolecule polydopamine (PDA), and the remineralized dentine exhibited mechanical properties comparable to those of natural dentine. Detailed analyses of the collagen mineralization process facilitated by PDA showed that PDA can promote intrafibrillar mineralization with a decreased heterogeneous nucleation barrier for hydroxyapatite (HAP) by reducing the interfacial energy between collagen fibrils and amorphous calcium phosphate (ACP), resulting in the conversion of an increasing amount of nanoprecursors into collagen fibrils. The present work highlights the importance of interfacial control in dentine remineralization and provides profound insight into the regulatory effect of biomolecules in collagen mineralization as well as the clinical application of dentine restoration.

Amino acid sequence analysis in patients with chronic HCV genotype 1b infection during pegylated interferon-α2a and ribavirin therapy.

BACKGROUND: Amino acid variations in several HCV genomic regions have been reported to be associated with response to interferon (IFN)-α plus ribavirin (RBV) combination therapy. However, the results remain controversial. In this study, we further investigated the amino acid variation of full-length HCV genome and its correlation to the response to pegylated interferon (PEG-IFN)-α2a and RBV combination therapy in patients with HCV genotype 1b (HCV-1b). METHODS: We retrospectively analysed 18 chronic HCV-1b patients (9 with rapid virological response and 9 non-response to therapy) treated with PEG-IFN-α2a plus RBV for 48 weeks. The nearly full-length HCV genome sequence was amplified by reverse transcription (RT)-PCR followed by cloning and sequencing. Genetic diversity differences between two groups were analysed including the number of amino acid variations in the HCV polyprotein and the mean pair-wise protein distance. RESULTS: No single amino acid variations were closely associated with treatment outcome. However, the number of amino acid mutations in the NS5B region especially in the thumb domain and in the NS5A-V3 region was associated with the response to PEG-IFN-α/RBV therapy (P=0.002 and P=0.029, respectively). The number of substitutions in the NS5B region was significantly correlated with the numbers of substitutions in the V3 region (r=0.568, P=0.027). CONCLUSIONS: Amino acid substitutions in the NS5B region especially in the thumb domain and the NS5A-V3 region may play a role in the response to combined PEG-IFN-α2a and RBV therapy in HCV-1b patients.