Effectiveness of triple therapy with simeprevir for chronic hepatitis C genotype 1b patients with prior telaprevir failure.

Favourable efficacy and safety profiles for simeprevir in combination with pegylated interferon alpha (PEG-IFNα) and ribavirin (triple therapy) have been shown in clinical trials. This study was carried out to evaluate the effectiveness of simeprevir-based triple therapy for patients with prior telaprevir treatment failure. This multicentre, observational cohort consisted of 345 consecutive Japanese patients infected with HCV genotype 1b, including 20 who had experienced telaprevir-based triple therapy. Amino acid substitutions in the NS3/4A region were identified by direct sequencing at the time of relapse or breakthrough in treatment with telaprevir and at the initiation of treatment with simeprevir. Patients were stratified according to prior response to PEG-IFNα and ribavirin. Of the 20 patients with telaprevir treatment failure, 10 (50.0%) achieved sustained virological response at week 12 after the end of treatment (SVR12). For patients treatment naïve [3/4 (75.0%)] or with prior relapse [1/1 (100%)] or partial response [5/6 (83.3%)] to PEG-IFNα and ribavirin, almost all achieved SVR12, mainly because of the improvement of treatment adherence, especially to direct-acting antiviral agent and ribavirin. However, of the nine patients with prior null response to PEG-IFNα and ribavirin, only one (11.1%) achieved SVR12, despite all having received an adequate treatment dosage, and five (55.6%) achieved rapid virological response. The treatment outcome of simeprevir-based triple therapy for HCV genotype 1b patients with prior telaprevir failure depended on the prior response to PEG-IFNα and ribavirin. For patients with prior null response to PEG-IFNα and ribavirin, retreatment with simeprevir-based triple therapy is not a useful option.

Fiber system degradation, and periostin and connective tissue growth factor level reduction, in the periodontal ligament of teeth in the absence of masticatory load.

BACKGROUND AND OBJECTIVE: The periodontal ligament (PDL), which is interposed between the alveolar bone and roots, supports teeth against mechanical stress. Periostin and connective tissue growth factor (CTGF) might play essential roles in maintaining PDL fiber integrity under mechanical stress. However, this relationship has not been studied at the protein and gene levels. Therefore, the aim of this study was to assess the PDL fiber system without masticatory load to determine the structural changes in the PDL in the absence of mechanical stress. MATERIAL AND METHODS: The study included 45 Wistar male rats (12 wk of age) whose upper-right first molars were relieved from occlusion for 24 h, 72 h, 7 d or 21 d. The PDL was examined histologically, and changes in the gene and protein levels of periostin and CTGF were investigated. RESULTS: The PDL space width was reduced significantly. Histologically, an initial reduction in the fiber number and thinning of PDL fibers were observed, followed by disarrangement of the PDL fibers and their attachments to the alveolar bone; finally, the PDL fibers lost their meshwork structure. Real-time RT-PCR results revealed sharp down-regulation of the periostin and CTGF mRNA levels at 24 and 72 h, respectively, which continued throughout the experiment. Immunohistochemical analysis revealed that periostin localized to both the cellular elements and the extracellular matrix, whereas CTGF localized only to the cellular elements. Periostin and CTGF immunoreactivities became very weak without masticatory load. CONCLUSION: In the absence of mechanical stress, the PDL fiber system undergoes degradation concomitantly with a reduction in the periostin and CTGF levels in the PDL.

Long-term effects of local pretreatment with alendronate on healing of replanted rat teeth.

BACKGROUND AND OBJECTIVE: Our previous study showed that topical alendronate, an inhibitor of bone resorption, reduces root resorption and ankylosis for 21 d after replantation of rat teeth. The aim of the present study was to evaluate the long-term inhibitory effects of topical alendronate in the replanted teeth. MATERIAL AND METHODS: The rat maxillary first molars were extracted, placed in saline containing 1 mm alendronate (alendronate group) or saline (saline group) for 5 min and then replanted. The maxillae were dissected at 60 and 120 d. Microcomputed tomography horizontal sections at three root levels were analyzed for root and bone resorption, ankylosis and pulp mineralization. RESULTS: In the alendronate group at 60 and 120 d, the frequencies of resorption of roots and bone were lower than those in the saline group. The p values show statistical significances of lower frequencies in the alendronate group than in the saline group by chi-square test (see Table 1). Ankylosis and pulp mineralization occurred in the alendronate and saline groups. Bone marrow spaces were narrowed in conjunction with bone tissue expansion around the replanted teeth in the alendronate group. CONCLUSION: The inhibitory effects of topical alendronate were retained on root and bone resorption, but not on ankylosis and pulp mineralization, in the replanted teeth for 4 mo. Alendronate might also stimulate bone formation around the rat replanted teeth.

Changes in acid-phosphate content in enamel mineral during porcine amelogenesis.

The present study was undertaken to investigate changes in the acid-phosphate content of porcine enamel mineral during its development and to assess separately the HPO4(2-) pools in labile and stable forms. Enamel samples at the secretory and maturing stages of amelogenesis were obtained from the permanent incisors of five- to six-month-old slaughtered piglets. Human enamel from erupted, extracted teeth, synthetic hydroxyapatite, and carbonatoapatite containing acid phosphate were included as references. The acid-phosphate content of each sample was determined chemically through its pyrolytic conversion to pyrophosphate. The assessment of HPO4(2-) in labile forms was made by analysis of samples preequilibrated with solutions containing 3 mmol/L phosphate at pH11 (to de-protonate the HPO4(2-) species on crystal surfaces). The analytical results of porcine enamel samples showed that: (a) the outermost secretory (youngest) enamel contained the highest HPO4(2-), corresponding to about 16% of the total phosphate; (b) the acid-phosphate content decreased gradually to 10% in the inner (older) secretory and to 6% in the maturing tissue; (c) a substantial part of the HPO4(2-) in developing enamel tissue (50-60% of the HPO4(2-) for the secretory enamel) was in labile forms; and (d) the pool of the labile HPO4(2-) decreased with the growth of enamel mineral. In parallel studies with mature human enamel, it was ascertained that the total acid phosphate was only about 3% of the total phosphate, much lower than in developing porcine enamel, and that the labile pool of HPO4(2-) was also small, corresponding to about 15% of the total acid phosphate determined.(ABSTRACT TRUNCATED AT 250 WORDS)

Anti-peptide antibodies reactive with epitopic domains of porcine amelogenins at the C-terminus.

This was an immunological investigation of the processing of porcine amelogenins in situ. Rabbit and rat anti-peptide sera reacted specifically with the hydrophilic segment of the intact amelogenins at the C-terminus. The immunogens used were the synthetic peptides: (a) C13 composed of PATDKTKREEVDC and (b) C25 composed of MQSLLPDLPLEAWPATDKTKREEVD. These peptides correspond to the C-terminal 12- and 25-residue segments of porcine amelogenin, respectively. Cystine was introduced at the C-terminus of C12 for KLH-binding (C13). Western blot analysis disclosed that: (i) both rabbit and rat anti-C13 sera reacted selectively with the 25-kDa porcine amelogenin and three other minor components (27, 22 and 18 kDa); (ii) anti-C25 peptide sera, additionally, reacted with the 23-kDa amelogenins (a degradation derivative of the 25-kDa protein, lacking the 12-residue segment at the C-terminus) and as trace components, 20-, 16- and 14-kDa moieties. Importantly, all the proteins reactive with the anti-C13 serum were concentrated in the outer secretory enamel adjacent to the ameloblasts, decreasing significantly in the underlying inner secretory enamel. Immunohistochemical studies applying the anti-peptide sera to the developing tooth germs of a minipig also confirmed the localization of reactivity in the outer secretory region. Neither anti-peptide serum reacted with porcine non-amelogenins, serum proteins nor dentine matrix proteins at the dilutions tested. however, it was found that both the anti-C13 and C25 sera reacted with human keratin.(ABSTRACT TRUNCATED AT 250 WORDS)

A simple novel method of biliary drainage: gallbladder serosal wrapping after open choledochotomy.

In this study, we developed a new, simple technique for biliary drainage after open choledochotomy of choledocholithiasis. After the absence of intraductal stones was established by operative cholangiography and cholangioscopy, preserved gallbladder serosal wrapping was performed by inclosing a polyethylene tube (C-tube), which was inserted from the cystic duct to optimal portion of choledochus, within the gallbladder bed, with continuous suture of the preserved serosa of the gallbladder using 4-0 absorbable thread. This method was used in the cases of 8 patients. There was neither bile leakage nor residual bile duct stones. The C-tube could be removed after 7 days following surgery. The average hospital stay was 12.3 +/- 6.6 days. We propose that this procedure would be very simple and useful, and it would significantly shorten hospital stays after open choledochotomy of choledocholithiasis.

A method for the staining of intraosseous nerve fibers using Sihler's staining technique.

Understanding nerve fiber distribution in the jaw bone is important when performing invasive surgical treatments. Both microscopic and macroscopic anatomical techniques have been developed to study innervation. Conventional methods of removing and staining these structures, however, often alter structure and lack reproducibility of the resulting specimens. We sought to optimize Sihler's staining technique to stain intraosseous nerves in mandibles. Four cadaver specimens were used. The best staining of intraosseous nerve fibers was achieved by using the Plank-Rychlo solution. When the Styrene monomer was used, the resulting transparency was better than that obtained with glycerin under the same conditions. No significant differences were found between Sihler's staining procedure performed according to the conventional method and the procedure in which the second decalcification step was omitted. Our results demonstrate that applying Sihler's staining technique to bones makes them transparent and allows observation of nerves while preserving the external shape of the bone and maintaining the position of intraosseous nerve fibers. Our findings suggest our Sihler staining method for intraosseous nerve fibers can provide an intermediate resolution between macroscopic and microscopic techniques.

Telaprevir-based triple therapy for chronic hepatitis C patients with advanced fibrosis: a prospective clinical study.

BACKGROUND: Antiviral treatment is recommended for chronic hepatitis C patients with advanced fibrosis to reduce and prevent cirrhosis-related complications. AIM: To evaluate the efficacy and safety of telaprevir (TVR)-based triple therapy for patients with advanced fibrosis in a clinical practice setting. METHODS: This prospective, multicentre study consisted of 102 patients with advanced fibrosis (METAVIR score F3-4) who were infected with HCV genotype 1b. All received 12 weeks of TVR in combination with 24 weeks of pegylated interferon (PEG-IFN) α2b and ribavirin (RBV). RESULTS: The sustained virological response (SVR) rate was 69.6% (71 of 102). Notably, for treatment-naïve and prior relapse patients the SVR rate was over 80%. Previous treatment response, interleukin 28B polymorphism (rs8099917) and rapid virological response (undetectable HCV RNA at week 4) were independently associated with SVR. To achieve SVR, an adequate dosage of PEG-IFNα2b (≥1.2 µg/kg/week) and RBV (≥7.5 mg/kg/day) is preferable; however, the mean weight-adjusted TVR dosage had little impact on treatment outcome. Although severe blood cytopaenia and a dermatological disorder were frequently found, the rate of discontinuation due to adverse effects was 12.7%. The inosine triphosphatase CC allele (rs1127354) was independently associated with the development of severe anaemia, and lower serum albumin level (<35 g/L) was associated with the occurrence of infection. CONCLUSIONS: The great gain in the SVR rate by telaprevir-based triple therapy offsets the problems with adverse effects; thus, it should be considered as a potent treatment protocol for patients with advanced fibrosis, especially for those with treatment-naïve and prior relapse.

Histological investigation of osseous changes of mandibular condyles with backscattered electron images.

OBJECTIVES: This study aims to confirm the radiographic morphology of mandibular condyles with microscopic observation and to investigate the mechanism of osseous changes of adult human mandibular condyles. METHODS: Following the radiographic examinations of ten temporomandibular joints (TMJs) from five cadavers using conventional tomography, helical CT and limited cone beam CT for dentistry (limited CBCT), ten mandibular condyles were removed. Micro CT images were made of the undecalcified dissected joints in the sagittal plane, perpendicular to the long axis of the condyles, to produce images similar in orientation to the radiographic images. Tissue morphology was observed through backscattered electron images and elemental analysis using electron probe microanalysis (EPMA). The microscopic findings were compared with the radiographic findings. RESULTS: Limited CBCT images most accurately depicted erosive change of the bone cortex of the mandibular condyle. EPMA indicated bone remodelling in all mandibular condyles analysed, which showed cartilage calcification different from typical enchondral ossification. No finding of dissolution or disruption of the superficial soft tissue was observed in all specimens, including those presenting radiographic findings of osteoarthrosis. Active bone remodelling with hypertrophic changes of superficial soft tissue was observed in mandibular condyles, which implied radiographic findings of osteoarthrosis. CONCLUSIONS: The high detectability of limited CBCT images on bony morphology of mandibular condyles was confirmed. It is speculated that bone remodelling of adult human mandibular condyles is brought about by cartilage calcification. It was suggested that the osseous changes classified as osteoarthrosis with radiographic images are normal bone remodelling.

[Histogenesis of Sea Bream (Pagrus major) enameloid].

The enameloid matrix consists of a collagenous matrix, and non collagenous proteins. Mature enameloid is highly mineralised similarly to mammalian enamel a large amount of the protein being removed. This is in contrast with bone, cementum, and dentin, where a large amount of collagen remains in the completed tissue. From the results of a biochemical study it has been suggested that the decrease of a major part of both the collagenous protein in developing enameloid is brought about by proteolytic enzymes (Kawasaki et al. 1987). However, histological and histochemical observations were not made at that time. In this study fourty-five live specimens of Sea Bream (Pagrus major) were used for histological and histochemical observations. Four undemineralised serial cryostat sections were obtained from each tooth garm and the developing enameloid matrix was observed ultrastructurally. The results of this study, show that the proteolytic enzyme activity which could not be detected in the enameloid formative stage, but was demonstrable after mineralisation had spread across the thickness of the matrix. Further more, the stage at which the proteolytic enzyme could be obtained was related to the stage of ALPase activity found in the dental epithelial cells.

Competitive adsorption of magnesium and calcium ions onto synthetic and biological apatites.

Magnesium (Mg) is a conspicuous constituent of hard tissues but its possible role in biomineralization is poorly understood. It is possible that Mg2+ adsorbed onto bioapatites may contribute to the modulation of crystal growth as such inhibitory activity has been reported for synthetic apatites. The present study was undertaken to determine the adsorption isotherms of Mg ions onto synthetic apatites and biominerals in tooth and bone tissues in the presence of other ions of natural occurrence. Synthetic crystals used as adsorbents were hydroxyapatite and, as a better prototype for the biomineral, Mg-containing carbonatoapatite. Human enamel and dentin materials were obtained from extracted, caries-free, permanent teeth. Porcine dentin materials at two developmental stages were obtained from erupted deciduous and unerupted permanent teeth of a 6-month-old slaughtered piglet. Porcine bone was obtained from the cortical portion of the mandible of the same animal. All biomineral samples were pulverized and then treated by plasma ashing (deproteination) at about 60 degrees C. Each of the powdered samples was equilibrated in solutions containing various initial concentrations of Mg2+, Ca2+, and Na+ (or K+) as nitrate salts. Following equilibration, concentrations (and activities) of magnesium and calcium ions in the experimental solution were determined. The pH values of the equilibrium solutions were in the range of 6.2-6.5. Experimental data of the Mg adsorption onto hydroxyapatite were interpreted on the basis of a Langmuir-type model for binary systems assuming competition of Mg2+ and Ca2+ for the same adsorption sites on the crystal surfaces of the apatites.(ABSTRACT TRUNCATED AT 250 WORDS)

Enhanced, simplified glucose sensors: long-term clinical application of wearable artificial endocrine pancreas.

At present, 2 major problems should be solved before long-term application of the wearable artificial endocrine pancreas, the development of a reliable and stable glucose monitoring system and the development of a subcutaneous insulin infusion algorithm. With either a miniaturized extracorporeal glucose monitoring system based on microdialysis sampling method or a ferrocene-mediated needle-type glucose sensor covered with highly biocompatible membrane, poly(2-methacryloyloxyethyl phosphorylcholine-co-n-butyl methacrylate) (poly[MPC-co-BMA]) membrane, subcutaneous glucose concentrations could be monitored for 7 days without any in vivo calibrations, followed by 14 days with one point calibration. Considering the management and safety of the insulin delivery route, subcutaneous insulin infusion is obligatory. With the subcutaneous insulin infusion algorithm using a short acting insulin analogue (Insulin Lispro), near physiological glycemic control could be established in diabetic patients without showing any delayed hyperinsulinemia or hypoglycemia. The wearable artificial endocrine pancreas is now recognized as an excellent therapeutic tool for regulating blood glucose excursions physiologically in ambulatory diabetic patients on a long-term basis.

Effects of alendronate on restoration of biomechanical properties of periodontium in replanted rat molars.

OBJECTIVE: We examined the effect of the pretreatment of roots with alendronate on the restoration of the support function of the healing periodontal ligament in replanted rat molars. METHODS: The left maxillary first molars were extracted, placed in 0.9% NaCl containing 1 mm alendronate (alendronate group) or 0.9% NaCl (control group) for 5 min, and were replanted into their sockets. Groups of animals were killed at 7, 14, and 21 days after replantation. Normal control rats were also killed on the same days. The force required to extract the replanted or normal tooth from its socket was measured, and a load-deformation curve was developed and analyzed. Micro-computed tomography and histologic analyses were also made. RESULTS: The mechanical properties of the healing periodontal ligament in the alendronate group were gradually restored from 7 to 21 days. However, fractures of the roots and bones during mechanical testing occurred in most of the replanted teeth in the control group at 21 days. The rates of restoration of the mechanical strength, extensibility, stiffness, and toughness for the alendronate group at 21 days were 67, 98, 74, and 68% of the normal controls, respectively. Micro-computed tomography and histologic observations revealed that bone-like structures within the pulp and ankylosis between the roots and socket bones occurred commonly in the control group, but were uncommon in the alendronate group. CONCLUSIONS: Our findings suggest that the pretreatment with alendronate inhibits the formation of abnormal mineralized tissues and results in better restoration of the support function of the healing periodontal ligament in replanted teeth.